Glossary

A interface

This is the interface within the GSM network architecture between the BSS (Base Station Subsystem) and an MSC (Mobile Switching Centre). The interface supports standard 64Kbps channels for signalling and traffic. The primary protocols on this interface are DTAP (Direct Transfer Application Part) and BSSMAP (Base Station Subsystem Management Application Part).

A Link - Access link

Access link is a SL (Signalling Link) that connects a signalling end point i.e. a SP (Signalling Point) to an STP (Signalling Transfer Point). Only messages that are originating from or destined to the signalling end point are transmitted on this link.

A-GNSS - Assisted Global Navigation Satellite System

GNSS based location systems such as GPS (Global Positioning System) may take a significant amount of time to accurately calculate a device’s location, particularly if the satellite signals are being impaired by buildings, weather and other obstructions, or if the device is inside a building. A-GNSS enabled devices utilize the mobile network/Internet to provide additional location data, enabling the device to provide accurate location information more quickly.

A-key

A secret, 64bit pattern stored in the MS (Mobile Station) and HLR (Home Location Register) / AC (Authentication Center).It is used to generate/update the mobile’s SSD (Shared Secret Data).

a-law

ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) companding standard used in the conversion between analogue and digital signals in PCM (Pulse Code Modulation) systems. In contrast to the North American m -law, a-law provides a constant signal to distortion ratio over a broader dynamic range of analogue input signals at the expense of a poorer signal to distortion ratio for low level signals.

a-number

A term used to identify the number of the calling party.

A-SBC - Access Session Border Controller

The A-SBC is deployed between the access network and the service provider’s network edge in order to provide SIP related roles including security, NAT Traversal and media anchoring.

A/D - Analogue-to-Digital converter or conversion

The process of sampling an analogue waveform and describing it in terms of binary digits.

A1 Interface

A1 Interface The A1 interface carries signalling information between the Call Control and Mobility Management functions of the MSC (Mobile Switching Centre) and the call control component of the BSC (Base Station Controller).

A10 Interface

A10 Interface The A10 interface carries user traffic between the PCF (Packet Control Function) and the PDSN (Packet Data Serving Node).

A11 Interface

A11 Interface The A11 interface carries signalling information between the PCF (Packet Control Function) and the PDSN (Packet Data Serving Node).

A2 Interface

A2 Interface The A2 interface carries 64Kbps/56Kbps PCM (Pulse Code Modulation) information (voice/data) or 64Kbps UDI (Unrestricted Digital Information) between the MSC (Mobile Switching Centre) and the channel element component of the BSC (Base Station Controller).

A2DP - Advanced Audio Distribution Profile

The Advanced Audio Distribution Profile in Bluetooth specifies the protocols and procedures that define the distribution of high quality audio content, in either mono or stereo on ACL (Asynchronous Connectionless link) channels.

A3 - Authentication Algorithm A3

Authentication algorithm used in conjunction with Ki , the authentication key, and RAND , the random number generated in the AuC (Authentication Centre) to produce the SRES (Signed Response). This variable is used by the network to authenticate a MS (Mobile Station) requesting network resources.

A3 Interface

The A3 interface carries coded user information (voice/data) and signaling information between the Selection / Distribution unit function and the channel element component of the BTS (Base Transceiver System). The A3 interface is composed of two parts, Signaling and User Traffic. The signaling information is carried across a separate logical channel from the user traffic channel, and controls the allocation and use of channels for transporting user traffic. The user traffic is transported in traffic channels.

A38

A38 A single algorithm in GSM that performs the functions of A3 and A8.

A5 Interface

A5 Interface The A5 interface carries a full duplex stream of bytes between the IWF (Interworking Function) and the Selection / Distribution unit function.

A5/1 - Encryption Algorithm A5/1

Algorithm used in the GSM ciphering process between a MS (Mobile Station) and the GSM network.

A5/2 - Encryption Algorithm

A5/2 A5/2 – Encryption Algorithm A5/2 Algorithm used in the GSM ciphering process between a MS (Mobile Station) and the GSM network. This algorithm is simpler than A5/1 and was developed by ETSI (European Telecommunications Standards Institute) for use in Eastern European states that had restrictions to certain Western technologies.

A5/X

A5/X GSM encryption algorithms A5/0 to A5/7.

A7 Interface

A7 Interface The A7 interface carries signaling information between a source BS (Base Station) and a target BS.

A8 - Ciphering Key Generating Algorithm A8

This algorithm is used in conjunction with Ki , the authentication key, and RAND (Random Number) to generate Kc (Cipher Key). This is used with A5/X to cipher the data stream between the MS (Mobile Station) and the GSM network.

A8 Interface

A8 Interface The A8 interface carries user traffic between the BS (Base Station) and the PCF (Packet Control Function).

A9 Interface

A9 Interface The A9 interface carries signaling information between the BS (Base Station) and the PCF (Packet Control Function).

AA - Abbreviated Alert

An Abbreviated Alert is used to remind the subscriber that previously selected alternative routing features are still active.

AAA - Access, Authorization, and Accounting

Authentication, Authorization and Accounting systems implemented to securely determine the identity and privileges of a user and to track that user’s activities, particularly with respect to billing. Popular examples of AAA protocols which are used to transport AAA information around the network include RADIUS and Diameter.

AAC - Advanced Audio Codec

The AAC features in both the MPEG-2 and MPEG-4 standards and was designed to be the successor to MP3. As such, AAC can operate using a variety of bitrates whilst sustaining adequate sound quality. AAC has been adopted for use in a wide variety of devices, ranging from Apple’s iPod to the Nintendo Wii. A low bitrate variant of the AAC, termed the HE-AAC (High Efficiency Advanced Audio Codec) is also available.

AAL - ATM Adaptation Layer

Provides a conversion function to and from ATM (Asynchronous Transfer Mode) for various types of information, including voice, video, and data. There are several versions of AAL, each applicable to a given information type. All of them convert elements of an information stream (such as voice frames and data packets) into cells, giving ATM the versatility to carry many different types of data, from constant rate voice data to highly bursty messages generated by LAN (Local Area Network), all within the same cell format.

AAL1 - ATM Adaptation Layer 1

The AAL1 adaptation layer is used to support continuous bit rate transmissions with a constant delay.

AAL2 - ATM Adaptation Layer 2

AAL2 supports continuous bit rate transmissions, but also solves the problems of packetization delay and efficiency in the use of bandwidth resources.

AAL5 - ATM Adaptation Layer 5

The AAL5 adaptation layer was developed because of concerns about the overhead and performance of the AAL3/4 adaptation layers. The result is a very simple and light weight adaptation layer.

AAR - Authorization Authentication Request

A Diameter message used in the PCC (Policy and Charging Control) framework which allows an Application Function to supply session related information to the PCRF.

AB - Access Burst

This is used by GSM and GPRS mobiles when accessing the system. It is smaller than other transmissions since it is typically transmitted when timing information is not known.

ABI - Application Binary Interface

A binary interface for applications to utilize external and/or underlying software or hardware.

Abis Interface

The interface within the GSM architecture, between the BTS (Base Transceiver Station) and BSC (Base Station Controller). This interface is usually configured using a 16Kbps slot structure.

ABM - Asynchronous Balanced Mode

This mode refers to the data link layer and identifies that a link has been established for sending information. The opposite state is ADM (Asynchronous Disconnect Mode).

ABMF - Account Balance Management Function

The ABMF is a logical element of the 3GPP OCS (Online Charging System) which is designed to track the remaining credit a subscriber has left on their account.

ABNF - Augmented Backus-Naur Form

ABNF – Augmented Backus-Naur Form A standard programming syntax used to express the command messages in distributed programming.

ABR - Area Border Router

A router that attaches to multiple areas of an OSPF based network. Area border routers run multiple copies of the basic algorithm, one copy for each attached area. Area border routers condense the topological information of their attached areas for distribution to the backbone. The backbone in turn distributes the information to the other areas.

ABR - Available Bit Rate

QoS (Quality of Service) class defined by the ATM (Asynchronous Transfer Mode) Forum for ATM networks. ABR is used for connections that do not require timing relationships between source and destination. ABR provides no guarantees in terms of cell loss or delay, providing only best-effort service. Traffic sources adjust their transmission rate in response to information they receive describing the status of the network and its capability to successfully deliver data.

ABR - Available Bit Rate

QoS (Quality of Service) class defined by the ATM (Asynchronous Transfer Mode) Forum for ATM networks. ABR is used for connections that do not require timing relationships between source and destination. ABR provides no guarantees in terms of cell loss or delay, providing only best-effort service. Traffic sources adjust their transmission rate in response to information they receive describing the status of the network and its capability to successfully deliver data.

AC - Access Category

The term Access Category is used in wireless networks supporting the IEEE 802.11e Quality of Service standard. There are four defined Access Categories – Voice, Video, Best Effort and Background.

AC - Access Class (C0 to C15)

AC – Access Class (C0 to C15) In GSM , the Access Class indicates the type of access that is permitted. This class is broadcasted over the air interface. If a mobile is a member of at least one of the signalled access classes then it may attempt to access the network.

AC - Attachment Circuit

The physical or virtual circuit attaching a CE to a PE. An AC can be a Frame Relay DLCI , an ATM VPI / VCI , an Ethernet port, a VLAN , a HDLC , a connection on a physical interface, a PPP session from an L2TP tunnel, an MPLS LSP , etc.

Access Code

In Bluetooth, each baseband packet starts with an Access code, which can be one of 3 types: CAC (Channel Access Code), DAC (Device Access Code) and IAC (Inquiry Access Code). The respective access code types are used for a Bluetooth unit in different operating modes. The CAC (Channel Access Code) identifies a piconet. The DAC (Device Access Code) is used for special signalling procedures and the IAC (Inquiry Access Code) is used to discover other Bluetooth units that are in range.

Access Control Method

This is the main distinguishing feature between different LAN (Local Area Network) technologies. It regulates each workstation’s physical access to the cable (transmission medium), and determines the order in which nodes gain access so that each user gets efficient service. Access methods include token passing, which is used in Token Ring and FDDI (Fibre Distributed Data Interface), and CSMA/CD (Carrier Sense Multiple Access with Collision Detection), which is employed by Ethernet and Fast Ethernet systems.

Access delay

The Access delay is the value of elapsed time between an access request and the successful access of the network.

Access Protocol

A set of specific procedures that enable a user to obtain services from a telephone company or network.

Access Server

Communications processor that connects asynchronous devices to a LAN (Local Area Network) or WAN (Wide Area Network) through network and terminal emulation software. It performs both synchronous and asynchronous routing of supported protocols and is sometimes called a NAS (Network Access Server).

Access Stratum SDU - Access Stratum SDU (Service Data Unit)

Unit of data transferred over the access stratum SAP (Service Access Point) in the Core Network or in the User Equipment.

ACCH - Associated Control Channel

The GSM signalling channels associated with a user’s traffic channel or dedicated signalling channel. Two ACCH are defined for GSM Circuit Switched operation. These are SACCH (Slow Associated Control Channel) and FACCH (Fast Associated Control Channel). In GPRS packet operation, an ACCH is allocated in conjunction with a PDTCH (Packet Data Traffic Channel) and is termed a PACCH (Packet Associated Control Channel).

Account Code

A numeric code that identifies the calling party for internal billing or accounting purposes. Account codes are often used by service companies such as accountants and lawyers to bill specific clients for telephone expenses. Also known as a project code or bill-back code.

Accounting

Accounting is the process of apportioning charges between the Home Environment, Serving Network and User.

Accuracy

The Accuracy indicates the performance criterion that describes the degree of correctness with which a function is performed.

ACD - Automatic Call Distributor

A device that handles a large number or incoming calls. An ACD performs four functions: first, it recognizes and answers incoming calls; second, it looks in a database to decide how to route the call; third, based on these instructions, it sends the call to an answering position based on a pre-determined, logical answering pattern. (Or, if all positions are busy, the ACD plays a recorded message and places the call in a queue until an answering position becomes available). Finally, the ACD connects the call to an agent, once that agent has completed the previous call.

ACELP - Algebraic Code-Excited Linear Prediction

A process employed in analysis by synthesis codecs in order to predict the filter coefficients required to synthesize speech at the receiving party. This process is employed in the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) G723.1 codec specification.

ACF - Admission Confirm

An H.225 message sent by a H.323 Gatekeeper to an endpoint that has requested access to the zone controlled by the Gatekeeper. This message indicates a successful acknowledgement to the endpoint that issued the ARQ (Admission Request) message.

ACI - Adjacent Channel Interference

The phenomenon whereby channels that are beside one another in the frequency domain may have some spectral overlap, causing impairment and interference.

ACID - HARQ Channel Identifier

The ACID (HARQ Channel Identifier) Differentiates channels within a HARQ (Hybrid Automatic Repeat Request) connection.

ACL - Access Control List

A roster of users and groups of users, along with their access rights.

ACLR - Adjacent Channel Leakage Ratio

The Adjacent Channel Leakage Ratio is the ratio of the on channel transmit power to the power measured in one of the adjacent channels.

ACM - Accumulated Call Meter

The accumulated charge for both the current call and all proceeding calls. This value is calculated by the MS (Mobile Station) and expressed in home units. The ACM is stored on the SIM / USIM (Subscriber Identity Module / UMTS Subscriber Identity Module).

ACM - Address Complete

An ISUP (ISDN User Part) signalling message sent by the destination switch indicating that a switched circuit has been established to the requested endpoint. This message is an acknowledgement to the switch issuing the IAM (Initial Address Message).

ACMC - Access Channel Message Capsule

This term is given to the AC (Access Channel) message plus any additional overheads or padding.

ACO - Additional Call Offering

An ISDN feature that allows multiple calls to be placed simultaneously to the same telephone number. A serving switch is programmed with the number of lines on the receiving telephone equipment. The switch will offer an additional call if there is a line available to accept it.

ACP - Automatic Call Processing

A system in which calls are processed entirely by computer.

ACR - Access Channel Request

An Access Channel Request is a message that is autonomously generated by the MS (Mobile Station) and is used to request radio resources from the network.

ACR - Accounting Request

A Diameter message used by network nodes to supply billing related information to the offline charging system.

ACS - Access Channel Slot

The assigned time interval for an access probe. An Access Channel slot consists of an integer number of frames. The transmission of an access probe is performed within the boundaries of an Access Channel slot.

ACS - Adjacent Channel Selectivity

This relates to the ability of a radio receiver to correctly receive the desired radio channel in the presence of strong adjacent signals.

ACSE - Application Control Service Element

The Application Control Service Element is a Layer 7 protocol used in the management of two peer entities by either connecting releasing or aborting the association between them.

Active Communication

A UE (User Equipment) is in active communication when it has a CS (Circuit Switched) connection established. For PS (Packet Switched) operation, active communication is defined by the existence of one or more Activated PDP (Packet Data Protocol) contexts. Either one or both of the mentioned active communications may occur in the UE.

Active Mode

In the Active Mode, the Bluetooth unit actively participates on the channel. The master of the piconet schedules the transmission based on traffic requirements to and from the slaves. It also allows regular transmissions to keep piconet slaves synchronized to the channel. An active slave will listen for packets at predetermined times; if not addressed, the active slave may sleep until the next scheduled master transmission.

Active Monitor

A node on a Token Ring network which purges the ring and generates a new token (when necessary), initiates and monitors neighbour notification, and maintains the master clock.

Active Set

Active Set A set of radio links simultaneously involved in a specific communication service between the UE (User Equipment) and the UTRAN (UMTS Terrestrial Radio Access Network).

ad hoc

This is a term used to describe an IEEE 802.11 networks operating in IBSS (Independent Basic Service Set) mode in which no network infrastructure is utilized. As such, wireless Stations will communicate with each other across a temporary network.

Ad Hoc Network

An Ad Hoc network is formed by two or more wireless devices dynamically setting up a temporary network. This is achieved without using any existing network infrastructure. Examples of systems that employ Ad Hoc networks are Bluetooth and WiFi.

Address Mask

Used to select bits from an Internet address for subnet addressing. The mask is 32bits long and selects the network portion of the Internet address and one or more bits of the local portion. Sometimes called the subnet mask.

ADDTS - Add Traffic Stream

The term ADDTS is used in wireless networks supporting the IEEE 802.11e Quality of Service standard. It is used to carry the TSPEC and optional TCLAS messages between a QAP and QSTA.

ADM - Add/Drop Multiplexer

A Core SDH network element which allows data to be directly inserted into or extracted from an STM stream as it passes through the network, without demultiplexing the frame.

ADPCM - Adaptive Differential Pulse Code Modulation

A form of PCM (Pulse Code Modulation) that produces a digital signal with a lower bit rate than standard PCM. ADPCM produces a lower bit rate by recording only the difference between samples and adjusting the coding scale dynamically to accommodate large and small differences. Some applications use ADPCM to digitize a voice signal so voice and data can be transmitted simultaneously over a digital facility normally used only for one or the other.

ADSL - Asymmetric Digital Subscriber Line

A technology that allows data to be sent over existing copper telephone lines ( POTS ). ADSL supports data rates from 1.5Mbps to 9Mbps when receiving data (known as the downstream rate) and from 16Kbps to 640Kbps when sending data (known as the upstream rate). ADSL requires a special modem, termed the ATU-R (ADSL Termination Unit Remote). ADSL2+ is a more recent incarnation of ADSL and has been deployed widely. The difference between the two is a matter of data rate, with the later version offering downstream rates of up to 24Mbps and upstream rates of up to 1Mbps (theoretical). This is achieved using improved physical layer techniques in conjunction with a reduction in the permissible length of the last mile.

AEC - Automatic Echo Cancellation

Employed in speech circuits and VoIP (Voice over Internet Protocol) systems where excessive delay is experienced between the parties involved in the speech call.

AEF - Access Entry Handoff

The AEF is the act of transferring reception of the PCH (Paging Channel) from one base station to another. This occurs when the MS (Mobile Station) transitions from the Mobile Station Idle State to the System Access State.

AES - Advanced Encryption Standard

AES is a widely used encryption algorithm which is defined by NIST (National Institute of Standards and Technology). It employs a symmetric encryption algorithm and the Rijndael block cipher in order to protect user data.

AF - Active Frame

An Active Frame is a frame that contains data and is therefore enabled in terms of traffic power.

AF - Application Function

The AF is a logical element of the 3GPP PCC framework which provides session related information to the PCRF in support of PCC rule generation.

AF - Assured Forwarding

A QoS (Quality of Service) term employed within the DiffServ (Differentiated Services) policy. Assured Forwarding values are set as part of the PHB (Per Hop Behaviour) used by routers. This value is used to determine the degree of reliability a packet should be afforded within the DiffServ domain.

AGC - Automatic Gain Control

Receiver function that generates constant power output under varying power input.

AGCH - Access Grant Channel

The Access Grant Channel is used to assign resources to a user requesting access to the network. These resources will include the dedicated channel to be used along with timing advance information.

Aging

When applied to pilot channels, Aging is the mechanism through which a mobile maintains, in its NS (Neighbour Set), the pilots that have been sent to it by the BS (Base Station). It may also apply to the pilots whose handoff drop timers have recently expired.

AGPS - Assisted Global Positioning System

Assisted Global Positioning System is a technique enabling both mobiles and cellular networks to establish accurate positioning information. The system utilizes both the GPS (Global Positioning System) and the terrestrial cellular network and is one of the LCS (Location Services) methodologies.

AH - Access Handoff

An Access Handoff is the process of transferring reception of the PCH (Paging Channel) from one BS (Base Station) to another after the mobile has completed the AA (Access Attempt) and is in the System Access State.

AH - Authentication Header

AH is a version of IPSec which support authentication and integrity checking of each individual IP packet.

AICH - Acquisition Indicator Channel

The Acquisition Indicator Channel is a fixed rate physical channel with a spreading factor of 256 equating to 32Kbps. It is used to carry acquisition indicators which correspond to signatures on the PRACH (Physical Random-Access Channel).

AID - Association Identifier

This is a unique number which identifies a particular Association between an AP (Access Point) and a wireless Station.

AIFS - Arbitration Interframe Space

The term AIFS is used in wireless networks supporting the IEEE 802.11e Quality of Service standard. It defines a period of time, depended upon Access Category, a QSTA must wait before it can access the Wireless Medium.

AIFSN - Arbitration Interframe Space Number

This is a term used in IEEE (Institute of Electrical and Electronics Engineers) 802.11 networks which are supporting the QoS (Quality of Service) enhancements originally defined in the 802.11e standard. This parameter, which is transmitted from the AP (Access Point), is used by a station in order to determine the specific AIFS (Arbitration Interframe Space) value for each of the four EDCA (Enhanced Distributed Channel Access) classes.

AIUR - Air Interface User Rate

The AIUR (Air Interface User Rate) is the rate indicated between the Mobile Termination and IWF (Interworking Function) for transparent and non-transparent data services.

AK - Anonymity Key

AK is a term used in the UMTS AKA (Authentication and Key Agreement) architecture. AK is a 48-bit value derived from the f5 algorithm, which can then be employed to conceal the value of SQN (Sequence Number).

AKA - Authentication and Key Agreement

AKA is the term given to the mechanism which performs authentication and session key distribution in UMTS, IMS and LTE networks. The AKA process is different for each technology, but the main goal of authentication and key agreement is the same.

AL - Ambient Listening

In MCPTT ambient listening is a feature that allows a call to be instigated on an end user’s device without that device indicating that it is transmitting. Initiation of ambient listening can be done by an authorised MCPTT user that wishes to be listened to, or alternatively by a remote authorized MCPTT user, such as a dispatcher.

ALCAP - Access Link Control Application Part

Access Link Control Application Part is a generic name for the transport signalling protocol used to setup and tear down transport bearers. In UMTS the main ALCAP protocol is the AAL2 signalling protocol.

Alert

A signal (of some sort) that indicates a monitored parameter of the system is out of range. An example alert is an audible alarm when the system temperature gets too high. Alerts may also trigger action by the system monitoring software.

ALG - Application-Level Gateway

An ALG is a DPI device designed to provide security and overcome interoperability issues for a particular protocol or application. In effect, ALGs are a sophisticated type of firewall, analyzing the various fields associated with inbound or outbound traffic from a particular protocol and checking to see if contains malicious content or content that will cause an interworking problem. Numerous examples of ALGs have been developed for protocols such as SIP and HTTP.

ALI - Automatic Location Identification

This is a database used in emergency services dialling such as 999 or 911. The database will map a subscriber’s telephone number to their physical location.

AM - Acknowledged Mode

The acknowledged service in RLC (Radio Link Control) provides reliability through retransmission. These include but are not limited to: transfer of user data, segmentation and re-assembly, error correction, duplicate detection, protocol error detection and recovery, ciphering.

AM_ADDR - Active Member Address

The Bluetooth AM_ADDR (Active Member Address) represents an address used to distinguish between the active members participating in a piconet. Each piconet has one or more slaves connected to a master. The master allocates each active slave a temporary 3bit address. Any packets exchanged between master and an active slave will carry the associated AM_ADDR. The AM_ADDR is used for both master-to-slave packets and slave-to-master packets. The all-zero address (000) is used by the master for broadcasting packets.

AM/PM - Amplitude Modulation to Phase Modulation conversion

An impairment generated when a signal with amplitude variation impinges on a device that converts some of this variation to output signal phase changes.

Ambient Noise

The background noise that is present on a non-digital communications line at all times.

AMBR - Aggregate Maximum Bit Rate

LTE data bearers that are classified as Non GBR are scheduled according to the AMBR for the subscriber. This means that of the total radio resources available to all the Non GBR bearers that a subscriber has active cannot exceed the AMBR.

AMC - Adaptive Modulation and Coding

This provides link adaptation with various modulation schemes and channel coding rates being applied to an air interface channel.

AMD - Acknowledged Mode Data

AMD is a mode of RLC which ensures that transmitted SDUs are acknowledged upon successful reception. If necessary, SDUs can be retransmitted if they do not receive an acknowledgement.

AMF - Authentication Management Field

AMF is a term used within the UMTS AKA (Authentication and Key Agreement) architecture. The AMF is a 16 bit value which is used to set the acceptable synchronization window in both the UE (User Equipment) and the network.

AMF - Core Access and Mobility Management Function

The Core Access and Mobility Management Function is part of the 3GPP 5G Architecture. Its primary tasks include: Registration Management, Connection Management, Reachability Management, Mobility Management and various function relating to security and access management and authorization.

AMIS - Audio Messaging Interchange Specification

A series of standards aimed at addressing the problem of how voice messaging systems produced by different vendors can network or inter-network. Before AMIS, systems from different vendors could not exchange voice messages. AMIS deals only with the interaction between two systems for the purpose of exchanging voice messages. It does not describe the user interface to a voice messaging system, specify how to implement AMIS in a particular system, or limit the features a vendor may implement.

Amplifier

An electronic device used to increase the amplitude or power level of a signal. Amplifiers are used in telecommunications on analogue transmission lines to offset the signal loss that occurs as the signal is propagated along the line.

AMPS - Advanced Mobile Phone Service

A North American analogue cellular system developed in the 1980s. This was enhanced to DAMPS (Digital Advanced Mobile Phone Service).

AMR - Adaptive Multi Rate

A codec offering a wide range of data rates. The philosophy behind AMR is to lower the codec rate as the interference increases, thus enabling more error correction to be applied. The AMR codec is also used to harmonize the codec standards amongst different cellular systems (including VoLTE) and can operate as a narrowband or wideband version.

AMR-WB - AMR Wideband

The wideband derivative of AMR supports HD voice services, utilizing a range of operating modes to suit the available bandwidth (6.6 to 23.85kbps).

Analogue signal

A continuous signal that is infinitely and continuously variable in amplitude and/or frequency.

Analogue transmission

The transmission of continuously variable (analogue) signals. As a signal is transmitted along an analogue network, the signal strength eventually weakens or attenuates. Amplifiers may be installed in the network to amplify the signal, but because there is no way to differentiate between an analogue signal and noise, both are amplified. Therefore, noise tends to accumulate in an analogue network.

ANDSF - Access Network Discovery and Selection Function

ANDSF (Access Network Discovery and Selection Function) is designed to assist mobile devices in discovering offload destinations, including WiFi, WiMAX and CDMA2000 networks. The feature was designed to provide mobile devices with information about available alternative wireless networks and to enforce policies for selecting and using those networks.

ANF - Assigned Number Field

In MPLS and other VPN based networks VPN-IPv4 is used to ensure addressing spaces within the VPN do not cross. The VPN-IPv4 address is defined through the RD. The RD comprises of the AF (Administrator Field) and the ANF. The ANF defines the VPN-IPv4 variable and is populated by the service provider.

ANI - Automatic Number Identification

Term used in the United States of America by long distance carriers for CLI (Calling Line Identity). This is an ISDN (Integrated Services Digital Network) function used to provide information to the user regarding the calling party.

ANM - Answer Message

An off hook signal sent in the reverse direction that indicates when the called party answers. Billing starts when the answer message is received.

ANR - Automatic Neighbour Relation

ANR is a SON feature associated with the automatic configuration of neighbour cell relations at a given base station. The Neighbour Relation Table held at the base station will contain an entry for each neighbouring cell. Each entry will contain all the information the base station needs to know about its neighbour.

ANS - Answer Message

An ISUP (ISDN User Part) signalling message sent by the destination switch indicating that the endpoint is now in the off-hook position i.e., the telephone has been picked up.

ANSI - American National Standards Institute

This is a US organization chartered to accredit standards developed by a wide variety of industry groups while avoiding improper influence from any one company or organization. ANSI does not develop standards, but reviews and implements those developed by other organizations.

Answerback

A signal sent by a data receiver to a data transmitter indicating that it is ready to receive data or to acknowledge the receipt of data.

ANT+

ANT+ is a wireless technology first developed by Dynastream (purchased by Gamin in 2006) and now under the auspices of the ANT+ Alliance that provides a series of standards enabling health and fitness sensors to pass information with compatible devices.

Antenna Gain - Antenna Gain (dBi)

The maximum gain an antenna in the horizontal plane (specified as dB (Decibels) relative to an isotropic radiator).

AOA - Angle of Arrival

AOA measurements are used to determine the direction from which a received radio signal originally emanated. Individual elements of an antenna array will utilize TDOA (Time Difference On Arrival) measurements, from which the AOA can then be calculated. In mobile networks, AOA measurements taken at several cell sites can be used together in order to identify the location of a subscriber. This technique is particularly useful for meeting the location accuracy requirements associated with E911 services but does require the subscriber to be in Line of Sight to the cell sites.

AoC - Advice of Charge

This service allows e-parameters to be passed to the mobile so that charge estimation can take place. This process is typically associated with the CAMEL Charging Information procedures.

AoR - Address of Record

An address-of-record (AOR) is a SIP or SIPs URI that points to a domain with a location service that can map the URI to another URI where the user might be available. Typically, the location service is populated through the SIP Registration process. An AOR is frequently thought of as the public address of the user.

AP - Access Point

The AP (Access Point) serves as the base station within a WLAN, terminating the air interface on the network side. They provide the link between the wireless world of 802.11 and the wired world of technologies such as Ethernet. They may also play a bridging function ensuring only traffic destined for a Station is transmitted across the Wireless Medium. This prevents information from being broadcast around the wireless element of the network at the expense of data throughput. Access Points can also perform other functions, e.g. manage QoS (Quality of Service) and take/provide measurements for roaming.

AP - Access Probe

An Access Probe involves a transmission consisting of a preamble and a message. The transmission incorporates a number of frames transmitted in one AC (Access Channel) message.

AP-AICH - Access Preamble Acquisition Indicator Channel

The Access Preamble Acquisition Indicator Channel is a fixed rate physical channel with a spreading factor of 256 used to carry AP (Access Preamble) acquisition indicators of CPCH (Common Packet Channel).

APCH - Auxiliary Pilot Channel

The Auxiliary Pilot Channel is a non data bearing, direct sequence spread spectrum signal transmitted by a CDMA (Code Division Multiple Access) BS (Base Station).

APH - Access Probe Handoff

An Access Probe Handoff occurs while the MS (Mobile Station) is performing an AA (Access Attempt) in the System Access State.

API - Application Programming Interface

A set of routines, protocols, and tools used when building software applications. A good API makes it easier to develop a program by providing all the building blocks and enabling a programmer to put the blocks together. Most operating environments, such as MS-Windows, provide an API so that programmers can write applications consistent with the operating environment. Although API are designed for programmers, they are ultimately good for users because they guarantee that all programs using a common API will have similar interfaces.

APN - Access Point Name

An Access Point Name provides routing information for SGSN (Serving GPRS Support Nodes) and GGSN (Gateway GPRS Support Nodes). The APN consists of two parts; the Network ID, which identifies the external service requested by a user of the GPRS service and the Operator ID which specifies routing information. Example: Operator ID = MNCyyyy.MCCzzzz.gprs Network ID = mpirical.net

APN AMBR - Access Point Name Aggregate Maximum Bit Rate

The Aggregate Maximum Bitrate which is applicable to a given APN. The total bandwidth associated with all the Non GBR bearers to the APN must not exceed the APN AMBR.

Applet

An Applet is a small program that is intended not to be run on its own, but rather to be embedded inside another application.

Application

An application consists of a set of security mechanisms, files, data and protocols (excluding transmission protocols) which are combined to provide a particular service for a user or system.

Application Context

This context signifies the type of process or procedure that is required typically on the MAP (Mobile Application Part) interfaces. Examples of Application Context include Location Updating and Location Cancellation.

Application Generator

Proprietary software to enable a user to produce a customized application, mainly for PC based systems.

Application Interface

The Application Interface is a standardized interface used by application/clients to access service capability features.

Applications / Clients

These are services, which are designed using service capability features.

APS - Access Probe Sequence

An Access Probe Sequence consists of one or more probes on the AC (Access Channel).

APSD - Automatic Power Save Delivery

Automatic Power Save Delivery is a term used in WiFi to describe a power saving technique originally introduced in the IEEE 802.11e specification. It involves a QAP (Quality Access Point) delivering downlink frames (which belong to a specified Access Class) to Power Saving stations automatically, thereby preventing the need to poll for each frame as is usually performed. APSD defines two delivery mechanism – U-APSD (Unscheduled – Automatic Power Save Delivery) and S-APSD (Scheduled – Automatic Power Save Delivery).

AR - Area Router

A router within an OSPF (Open Shortest Path First) routing area with all directly connected networks belonging to the same area. Area routers run a single copy of the basic routing algorithm associated with OSPF.

AR - Autonomous Registration

Autonomous Registration is the method of registration in which the MS (Mobile Station) registers without an explicit command from the BS (Base Station).

AR_ADDR - Access Request Address

The Bluetooth AR_ADDR (Access Request Address) is used by the parked slave to determine the slave -to- master half slot in the access window it is allowed to send access request messages in. The AR_ADDR is assigned to the slave when it enters the park mode and is only valid as long as the slave is parked and is not necessarily unique.

ARFCN - Absolute Radio Frequency Channel Number

Within the spectrum allocated for cellular mobile communications, the radio channels are identified by ARFCN. If the system is operating in FDD (Frequency Division Duplex) mode then the channel number is associated with both the uplink and downlink radio channels. Within the GSM900 spectrum ARFCN 1 to 124 are used. In GSM1800 , ARFCN 512 to 885 are used and in GSM1900 ARFCN 512 to 810 are used.

ARI - Assist Request Instructions

This message is associated with gsmSRF procedures in which the gsmSRF is collocated with an MSC that is not involved with the call. Hence this MSC must assist with the call. The ARI is passed to the gsmSCF to indicate that it too has been requested to assist in the CAMEL service.

ARIB - Association of Radio Industries and Businesses

Association of Radio Industries and Businesses was established in 1995 with a charter from the Japanese Minister of Posts and Telecommunications. ARIB concentrates on the growth and development of the wireless industry, mainly looking at investigation, research development of new radio systems in the field of telecommunications and broadcasting. ARIB is one of the main partners in 3GPP (Third Generation Partnership Project ) and 3GPP2 (Third Generation Partnership Project 2).

ARJ - Admission Reject

This is an H.225 message sent by a H.323 Gatekeeper to an endpoint that has requested access to the zone controlled by the Gatekeeper. This message indicates an unsuccessful acknowledgement to the endpoint that issued the ARQ (Admission Request) message.

ARL - Adjusted Ring Length

Calculated to ensure that if there is a ring failure, the longest ring path is still within specifications. Generally associated with Token Ring , adjusted ring length ensures that the secondary ring can still function properly in the event of a failure on the shortest trunk cable.

ARP - Address Resolution Protocol

Internet protocol used to map an IP address to a MAC (Medium Access Control) address. It allows host computers and routers to determine the data link layer addresses through the ARP Request and ARP Response process.

ARP - Allocation and Retention Priority

ARP is related to the QoS of an EPS Bearer. At times of network congestion, the ARP value of a subscriber’s bearer will determine whether or not it can replace an existing bearer that has a lower ARP precedence or be replaced by new bearer with a higher ARP precedence.

ARPA - Advanced Research Projects Agency

An organization formed in the United States in 1958 to conduct R&D in order to advance technology and science. ARPA became DARPA in 1972 and later went on to develop the early global Internet.

ARPF - Authentication Credential Repository and Processing Function

The ARPF is a functional element of the UDM (Unified Data Management), responsible for generating 5G HE AV (5G Home Environment Authentication Vectors) based on the subscriber’s shared secret key.

ARPU - Average Revenue Per User

ARPU is a term used by telephone Operators/Carriers to indicate the financial revenue which is gained per subscriber on a monthly basis.

ARQ - Automatic Repeat Request

This is a rudimentary transmission error protection whereby the receiver requests a retransmission when it detects that errors have occurred in a frame.

ARU - Audio Response Unit

An Audio Response Unit is an output device that provides a spoken response to digital inquiries from a telephone or other device. For example, Press 1 to hear this information again; Press 2 to hear more options. It is also known by the generic name audiotex.

AS - Active Set

The Active Set defines the set of pilots associated with the CDMA (Code Division Multiple Access) Channels containing Forward Traffic Channels assigned to a particular MS (Mobile Station).

AS - Application Server

A logical node of the 3GPP IMS which performs specific functions related to the delivery of a particular IMS based service. Examples include the Telephony Application Server used in VoLTE networks to support Supplementary Services, as well as the IM (Instant Messaging) Application Server which is used to supported next generation messaging services.

ASA - Access Sub-attempt

An Access Sub Attempt is a subsequent AA (Access Attempt) after the original AA has failed or not been responded to. It may involve a sequence of one or more APS (Access Probe Sequences) on the AC (Access Channel) and contains the same message content as the original AA.

ASA - Authorised Shared Access

Authorised Shared Access relates to radio spectrum usage. It was introduced as an enabler to unlock access to additional frequency bands which are currently not allocated for mobile broadband. As such, it is an alternative to spectrum clearing/refarming. The concept was extended as LSA (Licensed Shared Access).

ASBR - Autonomous System Boundary Router

A router that exchanges routing information with routers belonging to other AS (Autonomous System). Such a router advertises AS external routing information throughout the Autonomous System. The paths to each AS boundary router are known by every router in the AS. AS boundary routers may be internal or area border routers, and may or may not participate in the backbone.

ASCII - American Standard Code for Information Interchange

Pronounced ask-ee, ASCII is a code for representing English characters as numbers, with each letter assigned a number from 0 to 127. For example, the ASCII code for uppercase M is 77. Most computers use ASCII codes to represent text, which makes it possible to transfer data from one computer to another. Text files stored in ASCII format are sometimes called ASCII files. Text editors and word processors are usually capable of storing data in ASCII format, although ASCII format is not always the default storage format. Most data files, particularly if they contain numeric data, are not stored in ASCII format. Executable programs are never stored in ASCII format. The standard ASCII character set uses just 7 bits for each character. There are several larger character sets that use 8 bits, which gives them 128 additional characters. The extra characters are used to represent non-English characters, graphics symbols, and mathematical symbols. Several companies and organizations have proposed extensions for these 128 characters. The DOS operating system uses a superset of ASCII called extended ASCII or high ASCII. A more universal standard is the ISO Latin 1 set of characters, which is used by many operating systems, as well as Web browsers.

ASE - Application Service Element

The function that allows applications to communicate with one another in a SS7 system. Examples of an ASE include TCAP (Transaction Capabilities Application Part) and MAP (Mobile Application Part).

ASIC - Application Specific Integrated Circuit

These are circuit designs used by manufacturers to consolidate many chips into a single package, reducing board size and power consumption.

ASME - Access Security Management Entity

The Access Security Management Entity receives the top-level keys in an access network from the HSS or HLR. For E-UTRAN access networks, the role of the ASME is assumed by the MME. The MME invokes the AKA procedures by requesting authentication vectors to the HE (Home environment). The HE sends an authentication response back to the MME that contains a fresh authentication vector, including a base-key named KASME.

ASN - Autonomous System Number

An ASN is a unique identifier associated with an AS (Autonomous System) which is used by a variety of routing protocols. The IANA (Internet Assigned Numbers Authority) is responsible for allocating blocks of ASN to RIR (Regional Internet Registry). RIR will then allocate ASN directly to AS operators.

ASN - Abstract Syntax Notation 1

A syntax notation type employed to specify protocols. Many protocols defined by the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) use this syntax format. Other alternatives are standard text or ABNF (Augmented Backus-Naur Form).

ASP - Application Server Process

The processing entity within a server responsible for a specific task or area of responsibility. A term typically associated with distributed processing.

Association

The term is found within an IEEE 802.11 network and identifies the service used to establish AP (Access Point) and Station mapping. An Association is required before any information can be passed between the Station and other nodes via the AP.

AST - Automatic Spanning Tree

Function that supports the automatic resolution of spanning trees in source-route bridging networks. It provides a single path for spanning explorer frames to traverse from a given node in the network to another. AST is based on the IEEE 802.1 standard.

Asynchronous

A method of transmitting data whereby each byte is clocked separately. One start bit is added to the beginning, and one or more stop bits to the end, of each character. Asynchronous transmission is the most rudimentary form of data communication, as the originating and recipient machines do not have to be in sync. It is commonly used for low speed transmission, as with a PC’s serial port.

AT - Action Time

The Action Time is the time at which the action implied by a message should take effect.

AT - Authorization Token

The term AT is used in a number of scenarios in order to support authorized access to a resource or network services. In particular, AT are used in the SBLP (Service Based Local Policy) architecture of the Release 5 3GPP IMS (IP Multimedia Subsystem) specifications. Here, the AT is passed from the P-CSCF (Proxy Call Session Control Function) to the IMS terminal which is making a request for a service. The IMS terminal can then use the AT in its request for network resources when it signals its IP-CAN (IP Connectivity Access Network).

ATB - All Trunks Busy

A single tone repeated at a 120ipm (impulse per minute) rate to indicate that all trunks in a routing group are in use.

ATCF - Access Transfer Control Function

The ATCF (Access Transfer Control Function) was introduced in Release 10 of the 3GPP specifications in order to reduce the voice interruption delay when conducting an SRVCC procedure. The ATCF acts as an anchor point for SIP signalling and sits between the P-CSCF and the I-CSCF/S-CSCF in the signalling flow. Moreover, the ATCF controls an ATGW (Access Transfer Gateway), which also acts as an anchor point but in this case for the media stream, as opposed to signalling. In terms of the physical location of the devices, the ATCF could be positioned with the P-CSCF or IBCF.

ATDPCH - Auxiliary Transmit Diversity Pilot Channel

ATDPCH – Auxiliary Transmit Diversity Pilot Channel The Auxiliary Transmit Diversity Pilot Channel is associated with the APCH (Auxiliary Pilot Channel), that is transmitted by a CDMA (Code Division Multiple Access) BS (Base Station) from the non-primary antenna when orthogonal transmit diversity is employed.

ATGw - Access Transfer Gateway

The ATGw is a media function that is used to anchor the media stream. It is controlled by the ATCF and in terms of the physical location the ATGw could be an IM-MGW.

ATI - Any Time Interrogation

This process enables the gsmSCF to interrogate the HLR for location and or subscriber information. This may subsequently be used in the service offered to the user.

ATIM - Announcement Traffic Indication Message

Announcement Traffic Indication Messages are used in IEEE 802.11 ad hoc or Independent BSS (Basic Service Set) networks to announce the existence of buffered frames. These messages are sent between wireless stations to prevent them entering power saving mode and to indicate there is data to follow.

ATIS - Alliance for Telecommunications Industry Standards

A Washington D.C. trade group heavily involved in standards issues, including interconnection and interoperability.

ATM - Asynchronous Transfer Mode

A network technology based on transferring data in cells or packets of a fixed size. The small, constant cell size allows ATM equipment to transmit video, audio, and computer data over the same network, and assure that no single type of data dominates the line. ATM creates a fixed channel, or path, between two points whenever data transfer begins. This differs from TCP/IP , in which messages are divided into packets and each packet can take a different route from source to destination. This difference makes it easier to track and bill data usage across an ATM network, but it makes it less adaptable to sudden surges in network traffic.

ATM Forum

An international consortium of hundreds of companies and users chartered to accelerate the use of ATM products and services by developing specifications and promoting the technology. The ATM Forum was responsible for development of a wide range of ATM standards. It worked in cooperation with standards bodies such as ANSI (American National Standards Institute) and ITU (International Telecommunication Union), submitting to them proposed standards. In 2004 the ATM Forum was merged with the MPLS and FR Alliance, which in turn developed into the IP/MPLS Forum.

Attendant Console

A large, specialized telephone set used by the operator to answer incoming calls and send those calls to the proper extension.

Attenuation

The progressive weakening of a signal as it travels away from its point of origin.

AU - Administrative Unit

An Administrative Unit is created during the process of forming the payload of an STM-1. The AU contains a pointer which identifies where in the payload the VC-4 (Virtual Container-4) data begins, thus differentiating between padding and data. The task of the AU is to provide adaptation between the Higher Order Channel Layer and the Multiplex Section Layer.

AuC - Authentication Centre

The AuC is associated with the HLR (Home Location Register) in a GSM or UMTS network. It provides authentication parameters for the authentication process such as authentication triplets in GSM or authentication vectors within UMTS.

Audiotex

Audiotex is a generic term for interactive voice response equipment and services.

AUG - Administrative Unit Group

In terms of SDH , AUG creation is the final stage in the formation of an STM-1. A unitary multiplexing procedure of an AU-4 creates an AUG (Administrative User Group). Alternatively, three AU-3 can be multiplexed together to create one AUG.

AUI - Attachment Unit Interface

Defined in IEEE 802.1 as the interface between an Ethernet Medium Attachment Unit and DTE (Data Terminal Equipment).

AUID - Application Unique ID

AUIDs are used to identify specific applications provided by XCAP (XML Configuration Access Protocol). Examples of AUIDs include resource-lists, pres-rules, rls-services and pidf-manipulation.

AUSF - Authentication Server Function

The Authentication Server Function is part of the 3GPP 5G Architecture. It is used to facilitate 5G security processes.

AUTHBS - Base Station Authentication Response

The Base Station Authentication Response is an 18bit pattern generated by the authentication algorithm. AUTHBS is used to confirm the validity of BS (Base Station) orders to update the SSD (Shared Secret Data).

Authentication

A means to establish or prove identity; verifying eligibility of users, machines, or objects.

AUTHR - Authentication Response

The Authentication Response is an 18bit output of the authentication algorithm. It is used by the core network to validate a MS (Mobile Station) onto the network. Once authenticated the mobile may access the services offered by the network.

AUTN - Authentication Token

The Authentication Token is sent in the Authentication Request message to the mobile along with a random number and KSI (Key Set Identifier). The variables within the AUTN are used by the mobile in the authentication process that it conducts with the network.

Auto Correlation Function

A function showing the relationship of a signal with a time shifted version of itself.

Automated Key Distribution

The distribution of cryptographic keys, usually in encrypted form, using electronic means, such as a computer network (e.g., down line key loading, the automated key distribution protocols of ANSI X9.17).

AUZ - Active User Zone

Within an Active User Zone, the MS (Mobile Station) makes its presence known via an explicit registration in order to activate tiered service features.

AV - Authentication Vector

Either a quintet or a triplet of parameters. The GSM authentication vector uses a triplet of parameters which provides temporary authentication data that enables a VLR (Visitor Location Register) or SGSN (Serving GPRS Support Node) to engage in GSM authentication with a particular user. A triplet consists of three elements: a network challenge termedRAND (Random Number), an expected user response termed SRES (Signed Response) and Kc (Cipher key). The UMTS authentication vector uses a quintet of parameters which provides temporary authentication data that enables an VLR or SGSN to engage in UMTS authentication with a particular user. A quintet consists of five elements: a network challenge (RAND), an expected user response termed XRES (Expected Response), CK (Cipher Key), IK (Integrity Key) and AUTN (Authentication Token).

AVC - Advanced Video Codec

Adopted by the MPEG-4 standards, AVC is used in a wide variety of scenarios to reduce required bandwidth yet maintain video quality. For example, where an MPEG2 encoded video stream would require approximately 18Mbps for high definition TV, MPEG-4, using the AVC, requires around half that bandwidth or roughly 8Mbps.

Average Transmit Power

The average transmitter output power obtained over any specified time interval, including periods with no transmission.

AVP - Attribute Value Pair

The term given to an information element of a Diameter message. Each Diameter message will typically contain several different AVPs, such as Destination-Host AVP, Server-Name AVP, Subscription ID AVP, Framed IP Address AVP, etc.

AVRCP - Audio/Video Remote Control Profile

The Audio/Video Remote Control Profile specifies the features and procedures that ensure interoperability between Bluetooth devices with audio/video control functions.

AWGN - Additive White Gaussian Noise

The common wideband channel thermal noise impairment, on which SNR (Signal to Noise Ratio) is typically based.

B Link - Bridge link

Bridge link is a SL (Signalling Link) that connects an STP (Signalling Transfer Point) to another STP. Typically a quad of B links interconnect peer (or primary) STPs (e.g. the STPs from one network to the STPs of another network). The distinction between a B link and a D link is rather arbitrary. For this reason such links may be referred to as B/D links.

B-ISDN - Broadband Integrated Services Digital Network

A network that employs switching techniques independent of transmission speeds, and that allows a network to expand its capacity without major equipment overhauls. B-lSDN supports gigabit speed circuits in the public network and high speed switching of all traffic types in public and private networks. B-lSDN also provide bandwidth on demand capabilities.

b-number

A b number refers to the called party number.

B-RAS - Broadband Remote Access Server

The B-RAS is a functional entity of DSL networks which is effectively the first point at which a subscriber’s IP traffic is processed for onward routing. Typically housed in the Local Exchange or Central Office, the B-RAS can also be responsible for IP address allocation and termination of PPP links. In modern DSL networks, it is not uncommon to see the functionality of a B-RAS contained within an IP – DSLAM.

B2BUA - Back to Back User Agent

A B2BUA is logically positioned between the IMS (IP Multimedia Subsystem) and external networks. It handles all SIP (Session Initiation Protocol) signalling, including session attempts, subscriptions, instant messaging, etc, as well as including signalling where the flows may be forward without B2BUA intervention. The originating Serving CSCF (Call Session Control Function) should route signalling through the B2BUA when the destination network is outside the home IMS. Unfortunately, the originating S-CSCF does not currently have functionality to decide when the call is destined for a 3GPP IMS network or a non 3GPP IMS network. As a consequence, the only solution is for the originating S-CSCF to statically insert the B2BUA for all the signalling that is leaving the home IMS.

BA - Behaviour Aggregate

In a DiffServ enabled network, a collection of packets with the same DiffServ codepoint crossing a link in a particular direction is termed a Behaviour Aggregate. Packets with the same DSCP get the same per-hop forwarding treatment (PHB) everywhere inside a single DiffServ domain.

BA List - BCCH Allocation List

This is a list of frequencies supported on the neighbouring cells. This parameter is broadcast on the BCCH (Broadcast Control Channel), giving mobiles the frequencies of the BCCH carriers on neighbouring cells. It is typically used by the MS (Mobile Station) in the cell selection and re-selection processes.

Back End

This term applies to functions and procedures of a database server, such as a node or software application designed to manipulate data on a network.

Backdoor

This is a hidden application or software tool set up for authorized users to easily access resources. If discovered, backdoors can also allow malicious hackers to gain access to a machine or software.

Backdoor Accounts

These are secret accounts installed on a machine to allow users, usually developers or administrators, to gain access to resources while bypassing usual authentication procedures. Backdoor accounts , if discovered, can be used by a malicious hacker to gain access to the machine or software.

Backup

Backup is the logical or physical provisioning of facilities to speed the process of restart and recovery following network failures. It also applies to redundant facilities, including duplicated transaction files, duplicated processors, storage devices, terminals, telecommunications hardware or switches.

BAIC - Barring of All Incoming Calls supplementary service

A cellular supplementary service, that when invoked sets flags in the network databases to stop a subscriber receiving incoming calls.

Band

Band relates to the range of frequencies between two defined limits.

Bandwidth

Bandwidth may be defined as the difference between the highest and lowest frequencies available for network signals. It is also used to describe the amount of data that can be transmitted in a fixed amount of time.

BAOC - Barring of All Outgoing Calls supplementary service

A cellular supplementary service, that when invoked sets flags in the network databases to stop a subscriber making outgoing calls.

BAR - Buffering Action Rule

The BAR is a rule which can be presented to a user plane element by a control plane element within either a CUPS (Control and User Plane Separation of EPC Nodes) or 5G Core network scenario. In particular, the BAR will determine how long data should be buffered for and also whether a packet count is applicable.

Baseband

Baseband is a form of modulation in which the information is applied directly onto the physical transmission medium.

Basel 2

Basel 2 is a set of regulations for risk management that came into force in 2006. Basel 2 has implications on IT Security due to the stringent requirements imposed on systems handling sensitive data, particularly those in the finance industry.

Baseline capabilities

These are minimal capabilities required for a serviceless UMTS UE (User Equipment) to operate within a network.

Basic Access Mode

Basic Access Mode This is a mode used on the Enhanced Access Channel where a MS (Mobile Station) transmits an Enhanced Access Channel preamble and Enhanced Access data in a method similar to that used on the AC (Access Channel).

Bastion Server

A server that is accessible from a public network (such as the Internet) without protection from a firewall.

BBF - Bearer Binding Function

The BBF is a functional element of the 3GPP PCC framework, situated within the PCEF or BBERF. The role of the BBF is to associate a PCC rule with an IP-CAN bearer as part of an IP-CAN session.

BC - Bandwidth Constraint

BC relates to MPLS Diffserv aware Traffic Engineering and signifies the proportion of a link’s total bandwidth that a single or multiple CT (Class Type) can utilize.

BC - Bearer Capabilities

Used within an ISDN based network to allow a user to inform the ISDN about the protocol they are using in the B Channel. A user requesting ISDN services must specify the BC, which can then be conveyed to the destination. In addition, ISDN network elements may also utilize the information contained within the BC field.

BCC - Base Station Colour Code

In the GSM system, this code is transmitted in the SB (Synchronization Burst) and is used in the MS (Mobile Station) to discriminate between cells using the same frequencies during the cell selection and camping on process. The BCC is also used to identify the TSC (Training Sequence Code) to be used when reading the BCCH (Broadcast Control Channel).

BCCH - Broadcast Control Channel (3GPP)

This downlink channel contains specific parameters needed by a mobile in order that it can identify the network and gain access to it. Typical information includes the LAC (Location Area Code) and RAC (Routing Area Code), the MNC (Mobile Network Code) and BA (BCCH Allocation) list.

BCCH - Broadcast Control Channel (3GPP2)

The Broadcast Control Channel is a code channel in a Forward CDMA (Code Division Multiple Access) Channel used for transmission of control information or broadcast messages from a base station to a MS (Mobile Station).

BCCH Chip Bit - Broadcast Control Channel Chip Bit

This is the number of PN (Pseudorandom Noise) chips per BCCH (Broadcast Control Channel) bit. The chip bits vary depending on the rate.

BCD - Binary Coded Decimal

A Binary Coded Decimal uses four bits to represent each decimal digit.

BCF - Base Station Control Function

The Base Station Control Function provides common control functions within a BTS (Base Transceiver Station), for example frequency hopping in the GSM system.

BCH - Broadcast Channel

The Broadcast Channel is a downlink UMTS transport channel that is used to broadcast cell and system information. The BCCH (Broadcast Control Channel) maps into the BCH transport channel, which in turn maps into the P-CCPCH (Primary Common Control Physical Channel) at the physical layer.

BCH - Broadcast Channels

In the GSM system these channels are only broadcast by the BTS (Base Transceiver Station). They provide sufficient information for the MS (Mobile Station) to locate, synchronize and access the network. The BCCH (Broadcast Control Channel), FCCH (Frequency Correction Channel) and the SCH (Synchronisation Channel) are all classed as BCH.

BCIE - Bearer Capability Information Element

The Bearer Capability Information Element is an ISDN information element used to describe the bearer services such as data rate and speech quality required by an individual user.

BCM - Bandwidth Constraint Model

A BCM is used in relation to MPLS Diffserv aware TE and identifies the maximum number of BC (Bandwidth Constraint) across a particular link and also which CT (Class Type) map to which BC and how.

BCN - Broadcast Control Channel Number

The Broadcast Control Channel Number identifies the Broadcast Control Channel. BCN number 1 corresponds to the Primary Broadcast Control Channel. BCN numbers 2 through 8 correspond to other Broadcast Control Channels.

BCSM - Basic Call State Model

The Basic Call State Model describes the basic processing steps that must be performed by a switch in order to establish and tear down a call.

BD_ADDR - Bluetooth Device Address

All Bluetooth transceivers are allocated a unique 48bit device address. It is divided into a 24bit LAP (Lower Address Part), a 16bit NAP (Non-significant Address Part) and an 8bit UAP (Upper Address Part).

BDR - Backup Designated Router

The BDR is used to provide redundancy in broadcast networks which are utilizing the OSPF (Open Shortest Path First) routing protocol. Should the Designated Router fail, the BDR, which like the DR is also adjacent to all routers, will take over.

BE - Best Effort

Best Effort is a PHB description used within the DiffServ QoS framework. In essence, if a packet receives BE forwarding treatment, the network is not guaranteeing any level of QoS.

Beacon Carrier

The Beacon Carrier is a term that is used to identify the main carrier on a cell which usually carries the SI (System Information) messages.

Bearer

The bearer is an information transmission path of defined capacity, delay and bit error rate, etc.

Bearer Capability

The Bearer Capability is a transmission function which the mobile requests to the network.

Bearer service

The Bearer Service is a type of telecommunication service that provides the capability for the transmission of signals between access points.

BER - Bit Error Rate

This a variable indicating the ratio between the total number of bits received to those that were errored during transmission. This ratio is typically employed when expressing the QoS (Quality of Service) of a particular bearer.

Best Effort QoS

The lowest of all QoS (Quality of Service) traffic classes. If the guaranteed QoS cannot be delivered, the bearer network delivers the QoS which can also be called best effort QoS.

Best Effort Service

A service model which provides minimal performance guarantees, allowing an unspecified variance in the measured performance criteria.

BF - Bad Frames

A Bad Frame is a frame classified with insufficient frame quality.

BFI - Bad Frame Indication

This is a message used to indicate that a frame has been corrupted, or received in error.

BG - Border Gateway (GPRS)

A Border Gateway function terminates the Gp interface to a PLMN (Public Land Mobile Network). This function is typically an edge router supporting the BGP (Border Gateway Protocol) and security protocols such as IPSec (IP Security).

BGCF - Breakout Gateway Control Function

The BGCF is used to route call signalling to and from the most appropriate soft switch/S-CSCF. The S-CSCF controls PSTN services through the use of soft switches and a BGCF. The soft switch comprises of a MGCF (Media Gateway Control Function) and a MGW (Media Gateway) and the BGCF has functionality in order to route traffic and signalling to the correct soft switch.

BGP4 - Border Gateway Protocol version 4

BGP-4 is an example of a Path Vector routing protocol and is described as the needle and thread which binds the Internet together. BGP-4 allows Policy and Reachability information to be passed between Border Routers of adjacent AS (Autonomous Systems) and also between Border Routers of the same AS, thus supporting global routing of IP datagrams. BGP-4 Update messages are passed between routers. These messages contain lists of destination prefixes (routes) in the NLRI (network Layer Reachability Information) field, as well as Path Attributes associated with those routes.

BGPC - BGP Communities

BGP communities are sets of routes with some common attribute.

BH - Busy Hour

The Busy Hour is the peak 60-minute period during a business day when the largest volume of traffic is handled by a network.

BIC-Roam - Barring of Incoming Calls when Roaming outside the home PLMN country supplementary service

A cellular supplementary service, that when invoked sets flags in the network databases to stop a subscriber receiving incoming calls when he or she is roaming outside of their HPLMN (Home Public Land Mobile Network).

BICC - Bearer Independent Call Control

BICC is protocol used in IP based transport networks in order to set up voice calls, typically between MGCFs (Media Gateway Control Functions). BICC is based on ISUP and as such uses a very similar message set. The difference between the two is that ISUP is based on a narrowband signalling bearer, whereas BICC is designed to run over a broadband network (typically IP but other protocols are possible). Therefore, when BICC is establishing a call, it is not establishing a TDM through connection (which is what ISUP usually does). Instead, BICC sets up a media bearer, which may be based on IP or ATM (Asynchronous Transfer Mode).

Billing

A function whereby CDR (Call Detail Records) generated by the charging function are transformed into bills requiring payment.

Biometric Security

Biometric security is the recognition and authentication of individuals based on unique combinations of measurable physical or behavioural characteristics. Examples include fingerprints, iris scanning, face and voice recognition, or hand geometry. All of these biometric techniques are differentiated by speed, durability, reliability, and cost effectiveness. Fingerprints are generally considered the most practical biometric identifier in use today and can be found on a number of PDA (Personal Digital Assistants).

Bitcoin

This is a well-known cryptocurrency which is based on the proof-of-work blockchain.

Bitmap

A bitmap defines a map of ѱӳ and Ѱӳ. When used for resource allocation the ѱҠindicates an allocated resource and a ѰҠindicates that no resources were allocated. Bitmaps are also used in retransmission systems to indicate which packets or frames should be sent again.

BITS - Building Integrated Timing Supply

A timing mechanism for providing a stable, precise clock reference for telecommunications network nodes.

BL - Bandwidth reduced Low complexity

Introduced in Release 13 of the 3GPP specifications, BL identifies a mobile that supports LTE-M NB (Narrowband) operation, i.e. operates in 1.4MHz Narrowbands.

Blank and Burst

Blank and Burst is the pre-emption of an entire traffic channel frame’s primary traffic by signaling traffic or secondary traffic. Blank and burst is performed on a frame by frame basis.

BLE - Bluetooth Low Energy

Bluetooth Low Energy, marketed as Bluetooth Smart, is a WPAN (Wireless Personal Area Network) technology developed by the Bluetooth SIG (Special Interest Group) aimed at IoT (Internet of Things) devices requiring significantly lower power consumption than traditional Bluetooth.

BLER - Block Error Rate

This typically defines the TB (Transport Block) error rate of the transport channel.

BLES - Broadband Loop Emulation Signalling

One approach establishes the VoDSL service is using BLES (Broadband Loop Emulation Signalling). This extends Class-5 servicing office capabilities (custom calling and Centrex services, as well as trunking for CPE (Customer Premises Equipment), along with high-speed data services to customers over DSL (Digital Subscriber Line).

Blind Transfer

Blind Transfer involves passing a call without notifying the recipient. It is also known as unsupervised transfer or cold transfer.

Block Cipher

A block cipher is a symmetric key that encrypts blocks of data. Examples may be 64bit, 128bit or 256bit encryption. While these ciphers are fast, as they require little processing, identical blocks of data will always produce the same cipher text under the same block cipher key. This characteristic is a weakness of block ciphers.

Block Reward

This is the reward given to a Miner which has successfully hashed a transaction block. Block Rewards can be a mixture of coins and transaction fees depending upon the policy used by the cryptocurrency in question.

Blockchain

This is a type of distributed ledger which is comprised of unchangeable, digitally recorded data in packages referred to as blocks. Each block is then chained to the next block using a cryptographic signature. This permits the blockchains to be used like a ledger and as such shared and accessed by anyone with the appropriate permissions.

Blockchain Mining

This is the distributed computational review process performed on each block of data in a blockchain. This enables a consensus to be arrived at within an environment where no party trusts or knows each other.

Blocked Call

A block call results when a call cannot be connected. The two most common reasons for blocked calls are when all lines or trunks to the central office or exchange are in use, or all paths through a PABX (Private Automatic Branch Exchange) or switch are in use. Another example is that of specific services such as premium rate where users request that their local carrier blocks such calls in order to avoid incurring charges.

Blocking

Blocking is the inability to establish a new call because of restrictions or inaccessibility of facilities in the system being called.

Blowfish

Blowfish is a well-used block cipher designed by Bruce Schneier. It encrypts 64bit blocks of plain text using a cipher key that may vary between 32bit and 448bit.

Bluetooth

This is a technical specification to standardize wireless transmission between a variety of devices such as PDA (Personal Digital Assistant), mobile phones, laptop computers, printers etc. The system operates at 2.45GHz and uses FHSS (Frequency Hopping Spread Spectrum). It operates over distances of approximately 10m and offers a gross data rate of 1Mbps.

Bluetooth Clock

Bluetooth units have an internal system clock which enables them to determine the timing and hopping of their transceiver. This clock is constantly running and is never adjusted. It operates at clock rate of 3.2KHz.

Bluetooth Device Class

The Bluetooth Device Class is a parameter received during the discovery procedure. It identifies the device type and indicates which services are supported.

Bluetooth Host

A Bluetooth Host can be a computing device, cellular telephone, peripheral device, an access point to an external network, etc. The Bluetooth Host is attached to a Bluetooth unit , which enables communication to other Bluetooth Hosts (which are attached to their Bluetooth units). The wireless communication channel between the Bluetooth units provides an almost wire-like functionality.

Bluetooth Profile

A Bluetooth Profile describes the operation of a device or application. The Bluetooth specifications identify profiles, each defining how to achieve a specific function. Typical profiles include: Dial-up Networking Profile, Headset Profile, File Transfer Profile etc.

Bluetooth Smart

Bluetooth Smart is the marketing name for BLE (Bluetooth Low Energy) which is a WPAN (Wireless Personal Area Network) technology developed by the Bluetooth SIG (Special Interest Group) aimed at IoT (Internet of Things) devices requiring significantly lower power consumption than traditional Bluetooth.

Bluetooth Unit

The Bluetooth Unit provides a short-range wireless communication link which allows voice and data communications between Bluetooth Hosts.

Bm - Bearer Mobile (Traffic Channel Full Rate)

In accordance with ISDN notation that is given to traffic channels (namely the B channel); in a GSM mobile network the ISDN channels supporting TCH/F (Traffic Channel Full Rate) are termed the Bm channels.

BM-SC - Broadcast Multicast Service Centre

The BM-SC forms an integral part of the 3GPP MBMS architecture. Positioned between the GGSN and the PDN (where the content is stored), the BM-SC is responsible for areas such as group membership, content collection, QoS management, announcement of multicast/broadcast sessions and security.

BMC - Broadcast and Multicast Control

BMC – Broadcast and Multicast Control In the UMTS system, this protocol adapts broadcast and multicast services on the radio interface.

BMSC - Broadcast Multicast Service Center

The BMSC is located in the core network, functioning as the interface between the distribution network (3G or 4G data network) and the content provider, in support of MBMS (Multimedia Broadcast Multicast Services) or eMBMS (Evolved Multimedia Broadcast Multicast Services). The BMSC’s role includes scheduling and transmission of broadcast/multicast content, billing, service announcements, security and content synchronization.

BOIC - Barring of Outgoing International Calls supplementary service

A cellular supplementary service, that when invoked sets flags in the network databases to stop a subscriber making international calls.

BOIC-exHC - Barring of Outgoing International Calls except those directed to the Home PLMN Country

A cellular supplementary service, that when invoked sets flags in the network databases to stop a subscriber making international calls apart from those to their HPLMN (Home Public Land Mobile Network).

BOOTP - Bootstrap Protocol

Bootstrap Protocol is a TCP/IP protocol that enables a network device to discover certain startup information, such as its IP address.

Bot

A Bot is an alternative name for a Zombie device. Bots are essentially computers or servers that have been infected with malware that has opened a back door into the system. This back door is used by a Botnet Controller to send instructions to the Bots, issuing commands which may range from initiation of a DDoS attack to facilitation of a spamming run. Numerous Bots form a Botnet.

Botnet

This is the term given to a collection of Bot or Zombie devices that are under the control of a Botnet Controller. Botnets are predominantly used to support spamming, although there are numerous examples of Botnets being used to launch DDoS attacks. The major problem with Botnets is the sheer scale of them; it is not uncommon to hear of Botnets that are comprised of hundreds of thousands of Bots. Many Botnets have a link to organized crime syndicates.

Botnet Controller

Also termed a Bot Herder, the Botnet Controller is the entity responsible for generating the commands used to control the actions of a Botnet. The Botnet Controller could be a single device, although Botnets can also be controlled by a number of proxy devices in order to keep the real identity of the controller secret.

BPDU - Bridge Protocol Data Unit

The Bridge Protocol Data Unit is a spanning tree protocol hello packet sent out at intervals to exchange information among bridges in the network.

BPP - Basic Printing Profile

The Basic Printing Profile is designed to operate over Bluetooth devices, for example between a PDA (Personal Digital Assistant) and a Bluetooth enabled printer.

BPSK - Binary Phase Shift Keying

Binary Phase-shift keying (BPSK) is a digital modulation scheme that conveys data by changing, or modulating, two different phase s of a reference signal (the carrier wave ). The constellation points chosen are usually positioned with uniform angular spacing around a circle. This gives maximum phase-separation between adjacent points and thus the best immunity to corruption. They are positioned on a circle so that they can all be transmitted with the same energy. In this way, the moduli of the complex numbers they represent will be the same and thus so will the amplitudes needed for the cosine and sine waves.

Break

To break is to interrupt the sending of a message and take control of the circuit at the receiving end. It is a term also used to describe the interruption of a transmission or process.

BRF - Bridge Relay Function

Defined by the IEEE (Institute of Electrical and Electronics Engineers) an internal bridge function on a Token Ring switch that is responsible for forwarding frames between port groupings with the same logical ring number. Within a BRF, source route bridging or source route transparent bridging can be used to forward frames.

BRI - Basic Rate Interface

The Basic Rate Interface is an ISDN interface composed of two B channels (at 64Kbps) and one d channel (at 16Kbps) for circuit switched communication of voice video and data

Bridge

A bridge is a device that passes information between two network segments. It operates at Layer 2 of the OSI (Open Systems Interconnection) reference model. This layer is termed the Data Link Layer.

Broadband

The term Broadband in radio systems identifies a type of communication channel capable of carrying a large portion of the electromagnetic spectrum. It may also be applied to fixed communication systems when referring to bearers capable of carrying high volumes of traffic.

Broadcast

In fixed systems a broadcast is a data packet that is sent to all nodes on a network. Broadcasts are usually identified by a broadcast address. Cellular systems may indicate a broadcast by placing the data packet on a particular channel rather than using a broadcast address.

Broadcast Address

A Broadcast Address is a special address reserved for use when sending a message to all stations on a network or specific area.

Broadcast Storm

A Broadcast Storm is an undesirable network event in which many broadcasts are sent at once. Broadcast storms use substantial network bandwidth and may cause network time outs.

Broadcast User Zone

Broadcast User Zone The Broadcast User Zone is a zone that is identified to the MS (Mobile Station) by means of broadcast messages. It corresponds to the RF (Radio Frequency) coverage area of a particular set of cells and sectors.

Browser

A Browser is a GUI (Graphical User Interface) based hypertext client application, such as Internet Explorer, Mozilla and Opera, used to interpret HTML (Hypertext Markup Language) codes in order to format pages passed using the HTTP (Hypertext Transfer Protocol) protocol.

BS - Base Station (Generic)

A Base Station is a term used usually to identify where the radio equipment is placed that generates the cell or cells.

BSA - Basic Service Area

A BSA is an IEEE 802.11 conceptual area within which members of a BSS (Basic Service Set) may communicate.

BSC - Base Station Controller

The BSC forms part of the BSS (Base Station Subsystem) and controls a number of BTS (Base Transceiver Stations). In this role, the BSC is responsible for activities such as radio control, timing advance and handovers.

BSC - Base Station Controller (3GPP2)

The BS (Base Station) consists of a BSC and one or more BTS (Base Transceiver Station). The BSC is responsible for the exchange of messages towards the MSC (Mobile Switching Center) and the BTS. Traffic and signaling transferred between the MSC and MS (Mobile Station) will usually pass transparently through a BSC.

BSIC - Base Station Identity Code

This is a code in GSM which is broadcast on the SCH (Synchronization Channel) in order to identify the NCC (Network Colour Code) and the BCC (Base Station Colour Code).

BSICNCELL - BSIC of an adjacent cell

BSIC NCELL – BSIC of an adjacent cell This code is used to identify and decode the BCCH (Broadcast Control Channel) of neighbouring cells so that the MS (Mobile Station) may take measuring reports to facilitate handover, or to allow the MS to make cell selection and reselection calculations.

BSR - Buffer Status Report

Part of the 4G and 5G system, the Buffer Status Report procedure provides the serving cell with information about the amount of data in the uplink buffers available for transmission.

BSS - Base Station System

In GSM the Base Station System is a term given to a BSC (Base Station Controller) and the BTS (Base Transceiver Station) associated with it. The number of BTS associated with a BSC is dependent on the manufacturer. Although not mandatory, through interpretation of the Abis interface standard BTS and BSC employed within a BSS will always be supplied by the same manufacturer.

BSS - Basic Service Set

The Basic Service Set is a term used to describe the collection of Stations which may communicate together within an 802.11 network. The BSS may or may not include AP (Access Point) which provide a connection onto a fixed distribution system such as an Ethernet network. Two types of BSS exist; IBSS (Independent Basic Service Set) and Infrastructure Basic Service Set.

BSS - Business Support Systems

BSS is the general term given to the tools and techniques a service provider uses to manage its business operations associated with customers. BSS encompasses areas such as customer relations, billing, product management and order fulfilment.

BSSAP - Base Station Subsystem Application Part

BSSAP is used to transfer Mobility Management and Session Management information between the BSS (Base Station Subsystem) and the MSC (Mobile Switching Centre) or MSS (Mobile Soft Switch). As such, BSSAP is split into two sub application parts – BSSMAP (Base Station Subsystem Management Application Part) and DTAP (Direct Transfer Application Part).

BSSAP+ - Base Station Subsystem Application Part +

BSSAP+ is used to support signalling between the VLR (Visitor Location Register) and SGSN (Serving GPRS Support Node) on the Gs interface. Typical procedures used by the VLR include sending the BSSAP+ paging request message to a mobile via the GPRS service (this procedure applies to mobiles that are attached for GPRS services and non GPRS services and can be performed simultaneously with any other procedure at the Gs interface). Other procedures include the location update procedure.

BSSAPLE - Base Station System Application Part LCS Extension

BSSAP-LE is an extension to BSSAP (Base Station System Application Part) that contains messages and parameters specific in the support of LCS (Location Services). Two subsets of BSSAP-LE exist: BSSMAP-LE (Base Station System Mobile Application Part – LCS Extension) and DTAP-LE (Direct Transfer Application Part – LCS Extension).

BSSGP - Base Station Subsystem GPRS Protocol

The Base Station System GPRS Protocol is supported across the Gb interface, its primary functions include the provision by an SGSN (Serving GPRS Support Node) to a BSS (Base Station Subsystem) of radio related information used by the RLC (Radio Link Control) and MAC (Medium Access Control) function. In addition, the provision by a BSS to an SGSN of radio related information derived from the RLC/MAC function. Finally, the provision of functionality to enable two physically distinct nodes, an SGSN and a BSS, to operate node management control functions.

BSSGP - BSS GPRS Protocol

BSSGP conveys routing and QoS information across the Gb interface. This is achieved by encapsulating user data from LLC and also network and mobility management information. BSSGP also supports the transfer of PFC (Packet Flow Context) information. However, BSSGP does not perform error correction, leaving LLC to recover any errors which may exist.

BSSID - Basic Service Set Identifier

The BSSID is a 48bit identity used to identify a particular BSS (Basic Service Set) within an area. In Infrastructure BSS networks, the BSSID is the MAC (Medium Access Control) address of the AP (Access Point) and in Independent BSS or ad hoc networks, the BSSID is generated randomly.

BSSMAP - Base Station Subsystem Management Application Part

BSSMAP is used to convey general BSS (Base Station System) control information between the MSC (Mobile Switching Centre) and the BSS. An example of use is the allocation of traffic channels between the MSC and the BSS. Many BSSMAP procedures are triggered by or trigger RR (Radio Resource) management messages from the air interface.

BSSOMAP - Base Station System Operation and Maintenance Application Part

BSSOMAP – Base Station Subsystem Operation and Maintenance Application Part This protocol is used to convey general BSS OM (Operations and Maintenance) information between the MSC (Mobile Switching Centre) and the BSS (Base Station System).

BTS - Base Transceiver Station

A BTS will be controlled by a BSC (Base Station Controller) as part of the BSS (Base Station Subsystem). A BTS will support one or more cells, with key responsibilities including error protection/correction, encryption (GSM only), multiplexing and modulation.

Burst

In any TDMA (Time Division Multiple Access) based system, there is a need to transmit information in timeslots. This involves sending small blocks of information known as bursts.

Busy

This is a call condition in which transmission facilities are already in use. In a fixed network a line is considered busy when the caller goes off hook.

Busy Tone

This is a single tone that is repeated at a 60ipm (impulse per minute) rate to indicate that a call’s terminating location is already in use.

BVC - BSSGP Virtual Connection

The BSSGP Virtual Connection identifies an end to end virtual communication path between remote NS (Network Service) user entities.

BVCI - BSSGP Virtual Connections Identifier

The BSSGP Virtual Connection Identifier is used to route the BSSGP PDU between the SGSN (Serving GPRS Support Node) and the PCU (Packet Control Unit).

BWP - Bandwidth part

This is a subset of the total cell bandwidth. It is configured as part of BA (Bandwidth Adaption).

C

This is a procedural programming API (Application Programming Interface) for UNIX , Windows and other operating systems.

C Link - Cross link

Cross link connects STP (Signalling Transfer Point) performing identical functions into a mated pair. A C link is used only when an STP has no other route available to a destination signalling point due to link failure(s).

C-RAN - Cloud RAN

A general term for the introduction of virtualized network nodes within the radio access network. Cloud RAN can be applicable to 2G, 3G and 4G RAN technologies.

C-RAN - Cloud RAN

C-RAN is the term given to a RAN infrastructure which has been virtualized. C-RAN deployment typically see the processing capabilities of the cell site reduced, with the majority of the cell site protocol stack aggregated into a more centralized NFV (Network Functions Virtualization) solution. Consequently, all that remains at the cell site is physical layer (radio) capabilities, with functions such as baseband processing, scheduling and handovers all processed within a VNF (Virtualized Network Function) elsewhere in the network. In order to ensure scheduling and handovers are successful, latency between the cell site and the VNF must be minimised.

C-RNTI - Cell Radio Network Temporary Identifier

The Cell Radio Network Temporary Identifier may be allocated and used on common transport channels for optimization purposes. The decision to use the C-RNTI is made by the CRNC (Controlling Radio Network Controller).

C-TEID - Common Tunnel Endpoint Identifier

Within the context of eMBMS (Evolved Multimedia Broadcast Multicast Services), the C-TEID is related to the downlink TEID (Tunnel Endpoint Identifier) to which the MBMS traffic will be sent from the eMBMS Gateway to the eNB.

C/R - Command/Response field bit

Command/Response field bit is a control message used within HDLC (Higher Level Data Link Control) to tie command and response messages together.

C++

C++ was initially developed by Bjarne Stroustrup, a researcher at Bell Labs. Stroustrup developed an extension to the C language that facilitated the creation of objects and classes.

C1

C1 is a cell selection algorithm employed in GSM and GPRS. The algorithm uses the power received from cells plus additional parameters in order to assess the cell that will provide the best radio connection for the MS (Mobile Station).

C2

C2 is the GSM cell reselection algorithm. Once the MS (Mobile Station) has camped onto a cell it will continue to assess the surrounding cells to ensure it is monitoring the cell that will offer the best radio connection. As the user moves the camped on cell may become unsuitable. This situation will generate a cell reselection.

C31

C31 is a criteria based algorithm used as part of the GPRS cell reselection process. It is used to assess if prospective cells qualify as reselection candidates prior to applying the C32 GPRS cell reselection algorithm.

C32

C32 is the GPRS cell reselection algorithm. Once the MS (Mobile Station) has camped onto a cell it will continue to assess the surrounding cells to ensure it is monitoring the cell that will offer the best radio connection. As the user moves the camped on cell may become unsuitable. This situation will generate a cell reselection.

C7 - Also known as SS7 (Signalling System No. 7)

This protocol suite is used to initiate call related and non call related circuits on ISDN (Integrated Services Digital Network) based networks.

CA - Cell Allocation

This is the defined ARFCN (Absolute Radio Frequency Channel Number) list within a cell.

CA - Certification Authority

The CA (Certification Authority) is a trusted body that confirms the validity and identity of entities involved in public key exchange. As the user’s digital certificate is the only means by which entities may trust each other, the CA must be officially recognized. This is typically done by a government body authorizing a CA prior to its instigation. A well known CA, used by many commercial organizations, is Verisign.

CAB - Converged Address Book

The CAB is an evolution of the address book, it provides enriched information to existing contacts. The CAB enables end users to exchange Social Presence Information with authorized contacts. This includes availability status, portrait icons, text, favourite links and timestamp.

CAC - Connection Admission Control

An ATM (Asynchronous Transfer Mode) function used at the UNI (User to Network Interface) to ensure data presented to the network conforms to the traffic contract agreed between the customer and the ATM network provider.

CACH - Common Assignment Channel

This is a forward common channel used by the network to acknowledge a MS (Mobile Station) accessing the Enhanced Access Channel.

CACH Chip Bit. - Common Assigned Channel Chip Bit

This is the number of PN (Pseudorandom Noise) chips per Common Assignment Channel bit. The PN chips for the various spreading rates are detailed: Spreading Rate CACH Chip Bits Rate 1 128 bits at 9600bps Rate 3 384 bits at 9600bps

CAI - Charge Advice Information

A charging tariff sent from the MSC (Mobile Switching Centre) and held on the mobile; this is used to calculate billing information on the mobile and present it to the user as charging advice. This information should not be assumed to be the actual cost incurred for the call.

Call forward busy

Configurable feature that reroutes incoming calls to an alternate line when the first line is in use.

Call forward no answer

Configurable feature that reroutes incoming calls from one phone to another phone when the first phone is not answered after a certain number of rings.

Call forwarding

Configurable feature that sends incoming calls routed to a particular directory number to another number.

Call pickup

Configurable feature that allows a user to redirect an incoming call that was intended for another destination in order to retrieve the call on the user’s own phone or directory number.

Caller ID

A display, available to the called party before the party answers a telephone call. It identifies the originating telephone number.

CAMEL - Customized Application for Mobile network Enhanced Logic

CAMEL (Customized Application for Mobile network Enhanced Logic) application servers were introduced to mobile networks in order to supporting IN (Intelligent Networks) services such as prepaid billing. CAMEL application servers based on CAP (CAMEL Application Part) require an IMS SSF (Service Switching Function) in order to operate on a SIP (Session Initiation Protocol) based network (the SSF acts as a SIP to CAP gateway).

Camp On

After conducting the cell selection process a MS (Mobile Station) or UE (User Equipment) will camp onto the cell that offers the best perceived radio connection with the network.

Candidate Set

The Candidate Set is a set of pilots that have been received with sufficient strength by the MS (Mobile Station) to be successfully demodulated, but have not been placed in the Active Set by the BS (Base Station).

CAP - CAMEL Application Part

CAMEL Application Part is a real time protocol used to support the information flows between CAMEL (Customized Application for Mobile network Enhanced Logic) functional elements such as the SCF (Service Control Function) and SSF (Service Switching Function).

CAP - Controlled Access Phase

This is a term used in IEEE (Institute of Electrical and Electronics Engineers) 802.11 networks which are supporting the QoS (Quality of Service) enhancements originally defined in the 802.11e standard. The Controlled Access Phase defines a period of time in which the network is supporting the controlled channel access technique HCCA (Hybrid Controlled Channel Access).

CAPEX - Capital Expenditure

CAPEX identifies the monetary cost of a green field deployment or upgrade of physical infrastructure such as equipment or real estate.

CAPIF - Common API Framework for 3GPP northbound APIs

In order to attempt to standardize some of the common capabilities that are exposed by the Northbound APIs, the 3GPP have introduced CAPIF (Common API Framework for 3GPP northbound APIs). Within the standardization of CAPIF, the 3GPP have addressed a variety of different processes, including onboarding/offboarding of Application Functions, service discovery and management, event subscription and notification, security and charging.

CAPWAP - Control and Provisioning of Wireless Access Points

A control protocol which allows for the control and provisioning of large scale WLANs.

CAS - Channel Associated Signalling

Channel Associated Signalling is inband signalling in which user call data and signalling are combined.

CAST-128

CAST-128 is a very robust block cipher and is used to cipher 64bit blocks of plain text using a 128bit block cipher key.

CAT - Customized Alerting Tone

Also termed Color Tunes or Caller Tunes, this service plays a piece of music or audio clip to the Calling Party when a particular subscriber is dialled, as opposed to hearing the standard ringing tone.

CAZAC - Constant Amplitude Zero Auto-Correlation

3G and 4G mobile systems use code sequences with unique properties, e.g. for orthogonality. In LTE, Zadoff Chu codes are used for accessing the network and these have CAZAC (Constant Amplitude Zero AutoCorrelation) properties.

CB - Cell Broadcast

A Cell Broadcast is part of the SMS (Short Message Service) group function known as point to multipoint. These broadcasts are sent on the downlink CBCH (Cell Broadcast Channel). The type of information sent on this channel may include traffic reports and local weather information etc.

CB - Communication Barring

Communication Barring is a 3GPP Supplementary Service which allows users to dynamically block incoming communications from callers whom they consider as unwanted or unsolicited.

CBC - Cell Broadcast Centre

The CBC is an entity within a mobile network which is responsible for sending Cell Broadcast messages, termed SMS-CB. The CBC will supply the message to the appropriate BSCs, which in turn will pass them to the appropriate base stations. The CBC will determining the which specific area will receive the message, how long the message will be broadcast for and how frequently the message will be repeated.

CBC - Cipher Block Chaining

This is a term used to describe a common form of block ciphers which uses the previous encrypted block as a basis for encrypting the next block of plaintext. For the first block to be encrypted an Initialization Vector is required.

CBCH - Cell Broadcast Channel

The Cell Broadcast Channel is an additional feature of the GSM system. The channel supports part of the SMS (Short Message Service) group known as point to multipoint and is intended to be used for information such as traffic and weather reports. This is a downlink only channel and is mapped into the second subslot of the SDCCH (Standalone Dedicated Control Channel).

CBMI - Cell Broadcast Message Identifier

Cell Broadcast Message Identifier is found in the cell broadcast message header and is used to define the content of the cell broadcast message.

CBQ - Class-Based Queuing

A queuing algorithm used in routers to manage packets with different traffic characteristics. Incoming packets are classified on such variables as the DSCP (Differentiated Services Code Point) in the IP header. Each class of traffic is assigned to a specific FIFO (First In First Out) queue, each of which is guaranteed some portion of the total bandwidth of the router.

CBR - Constant Bit Rate

Constant Bit Rate is a service offered by a network technology such as ATM (Asynchronous Transfer Mode). This is used for real time services such as speech.

CBS - Committed Burst Size

CBS is a component of the bandwidth profile traffic parameters applicable to a service running over Ethernet networks. It is the number of allocated bytes available for bursts of service frames that are transmitted temporarily at rates above the CIR, while still meeting the SLA provided at the CIR.

CBWFQ - Class-Based Weighted Fair Queuing

Class-Based Weighted Fair Queuing allows traffic to be classified based on criteria, such as access control lists, input interface names, protocols, and QoS (Quality of Service) labels.

CC - Content of Communication

In relation to Lawful Intercept, content of communication describes the voice, text or data that a subscriber sends and receives as part of a communication service.

CC - Convolutional Code

CC (Convolutional Code) is a FEC (Forward Error Correction) technique used in technologies such as WiMAX.

CC - Country Code

A one, two, or three digit number used to specify the destination country for international calls. These are also used in mobile networks where they are ātermed MCC (Mobile Country Code). Typical examples are 234 for UK and 208 for France.

CCA - Clear Channel Assessment

Clear Channel Assessment is a logical function found within physical layers which determines the current state of use of a wireless medium. Such a function is found in IEEE 802.11 networks and aids in contention avoidance.

CCA - Credit Control Answer

The Consultative Committee for International Telegraphy and Telephony was a telecommunications organization that recommended worldwide standards for common carrier communications services. This organization was superseded by the ITU-T (International Telecommunications Union – Telecommunication Standardization Sector).This is a Diameter message which is typically used to carry a rule between the PCRF and the PCEF as part of the PCC framework.

CCBS - Completion of Calls to Busy Subscriber

When a called party is busy, this supplementary service enables the calling party to be connected to a called party after they have completed their call.

CCCH - Common Control Channel

Common Control Channels support common procedures required to establish a dedicated link with the network. Typical channels include the RACH (Random Access Channel), PCH (Paging Channel) and AGCH (Access Grant Channel) within GSM. In GPRS the common control channels include the PRACH (Packet Random Access Channel), PPCH (Packet Paging Channel) and PAGCH (Packet Access Grant Channel).

CCE - Control Channel Element

The E-UTRA CCE is a group of resources which can be used to send a PDCCH (Physical Downlink Control Channel). One, two, four or eight CCEs can be grouped to support larger messages. Each CCE consists of 9 REGs (Resource Element Group).

CCF - Call Control Function

This is a telephone industry term used to describe the setting up, monitoring, control and tearing down of calls.

CCF - Charging Collection Function

For offline charging IMS (IP Multimedia Subsystem) network elements report accounting information to the CCF. The CCF uses this information to construct and format CDR (Call Detail Recording).

CCH - Control Channel

A channel on which signalling is supported in order to establish a traffic circuit, or to pass information to the network.

CCITT - Consultative Committee for International Telegraphy and Telephony

The Consultative Committee for International Telegraphy and Telephony was a telecommunications organization that recommended worldwide standards for common carrier communications services. This organization was superseded by the ITU-T (International Telecommunications Union – Telecommunication Standardization Sector).

CCM - Current Call Meter

The accumulated charge as computed by the MS (Mobile Station). CCM is expressed in terms of home units. This function is used to provide AoC (Advice of Charge) to the user on the handset.

CCO - Cell Change Order

A Cell Change Order procedure enables 2G/3G/4G systems to trigger a mobile to move to a target cell without the benefit of a handover procedure, i.e., the resources will not be waiting in the target cell. CCO procedures are also available for Inter-RAT mobility.

CCP - Centralized Call Processing

Centralized Call Processing refers to a situation where all call processing is performed at a central site, or hub. No call processing is performed at branch sites.

CCR - Credit Control Request

This is a Diameter message which is typically used by the PCEF to request a rule from the PCRF as part of the PCC framework.

CCS - Common Channel Signalling

Common Channel Signalling is a signalling system used in telephone networks that separates signalling information from user data. Usually TS16 (Timeslot 16) on a E1 interface and TS1 (Timeslot 1) on a T1 interface, are exclusively designated to carry signalling relating to other traffic channels.

CCTrCH - Coded Composite Transport Channel

A data stream resulting from encoding and multiplexing of one or several transport channels.

CD - Call Deflection

A supplementary service in which the called user can choose to deflect the call onto a third party without answering the calling user.

CD/CAICH - CPCH Collision Detection/Channel Assignment Indicator Channel

The Collision Detection Channel Assignment Indicator Channel is a UMTS fixed rate physical channel used to carry CDI (CD Indicator) or CDI/ CAI (CD Indicator/CA Indicator) at the same time.

CDF - Charging Data Function

The CDF is an entity within the IMS (IP Multimedia Subsystem) billing architecture which is responsible for collating accounting requests from IMS CTF (Charging Trigger Functions) such as CSCF (Call Session Control Functions) and AS (Application Servers). The CDF will use the accounting requests to generate CDR (Charging Data Records), which will then be directed to the CGF (Charging Gateway Function) and then on to the billing domain.

CDI - Collision Detection Indicator

Collision Detection Indicator the Collision Detection Indicator is used to indicate if a collision has occurred during the channel assignment procedure

CDIV - Communication Diversion

This is a supplementary service which, if activated, will direct incoming calls for a subscriber to a different telephone number.

CDMA - Code Division Multiple Access

Code Division Multiple Access is a method for describing physical radio channels. Data intended for a specific channel is modulated with that channel’s code. These are typically pseudorandom in nature, and possess favourable correlation properties to ensure physical channels are not confused with one another. CDMA techniques are employed within cdmaOne, CDMA2000 and UMTS

CDMA Candidate Frequency

The CDMA Candidate Frequency is the frequency specified by the network to be searched for CDMA (Code Division Multiple Access) pilots.

CDMA Channel

The CDMA Channel is the set of channels transmitted between the BS (Base Station) and MS (Mobile Station) within a given CDMA Frequency Assignment.

CDMA Frequency Assignment

A CDMA Frequency Assignment is either a 1.23MHz or 3.69MHz segment of spectrum. The center of a CDMA Frequency Assignment is given by a CDMA Channel Number.

CDMA Preferred Set - CDMA Preferred Set.

The CDMA Preferred Set is the set of CDMA channel numbers in a CDMA system corresponding to frequencies that a MS (Mobile Station) will search to acquire a CDMA Pilot Channel. For CDMA cellular systems, the primary and secondary channels comprise the CDMA Preferred Set.

CDMA2000

CDMA2000 The CDMA2000 family of standards describe the use of CDMA (Code Division Multiple Access) technology to meet the requirements for 3G (Third Generation) wireless communication systems. The standards have been developed through comprehensive proposals from Qualcomm.

cdmaOne

cdmaOne is the commercial name for a CDMA (Code Division Multiple Access) system defined by the consortium including Qualcomm, ATT Wireless and Motorola.

CDR - Call Detail Record

A database record unit used to create billing records. A CDR contains details such as the called and calling parties, originating switch, terminating switch, call length, and time of day. When applied to GPRS, CDR are generated typically by the SGSN (Serving GPRS Support Node) and GGSN (Gateway GPRS Support Node), recording data volumes and QoS (Quality of Service) rather than call time. These records are passed to the CGF (Charging Gateway Function) for consolidation prior to being passed to the billing platform. With the introduction of the IMS, the acronym CDR is used to represent a Charging Data Record.

CDR - Charging Data Record

A CDR is a collection of information about a chargeable event such as the time of call set-up, the duration of the call, the amount of data transferred, etc that will be used for billing of a subscriber. It is possible that more than one CDR can be generated for a single chargeable event eg. a call that has taken place over a very long duration may have several CDRs associated with it.

CDV - Cell Delay Variation

The Cell Delay Variation is a term used in ATM (Asynchronous Transfer Mode) to describe the time difference that is acceptable between cells being presented at the receiving host.

CE - Certificate Enrollment

Digital Certificates are normally allocated by a trusted body known as a CA (Certification Authority). When a party or entity is allocated a certificate, it is described as certificate enrolment. This process involves the party requesting a certificate, providing the CA with a copy of its public key and additional identity information. This information in turn is signed by the CA. This involves the CA encrypting this information with its private key. The certificate is returned to the requesting party, which has now been enrolled.

CE - Coverage Enhancement

Introduced in Release 13 of the 3GPP specifications, CE identifies a mobile that supports additional features to enhance operation in poor coverage areas.

CEID - Customer Edge Identifier

In MPLS VPN, use of LDP requires manual configuration at both ends of the network, which is a significant disadvantage if VPN are to be implemented on a large scale. In contrast, if BGP is used for signalling and control, the BGP Auto discovery procedure will enable the pseudo wire to be established automatically. BGP Updates will be passed from an ingress LER to all egress LER. These updates will contain unique identifiers for CE devices attached to the ingress LER, known as CEID.

Cell

A cell when applied to mobile technologies defines a unit of geographical area.

Cell – ATM - Cell (ATM)

A cell is the basic data unit of the ATM (Asynchronous Transfer Mode) protocol. Cells contain identifiers known as VCI (Virtual Channel Identifier) and VPI (Virtual Path Identifier) to associate the cells with a logical data stream. Each cell consists of a 5-byte header and 48 bytes of payload. The cells are small in order to facilitate low processing delay and so high-speed transmission.

Cell Relay

This technology is employed typically at Layer 2. Small, fixed size cells are employed to minimize processing and switching time. They are typically switched through hardware processes in order to achieve high throughput speed. Typical cell-based technologies are ATM and Frame Relay.

Cell Reselection

When camped on a cell, the mobile shall regularly search for a better cell according to the cell reselection criteria. If a better cell is found, that cell is selected.

Cell Selection

The process whereby the mobile searches for a suitable cell, this is referred to as C1 or C31 in the GSM system and S in the UMTS system. The selected cell is then identified as the camped-on cell.

CELP - Code Excited Linear Predictive Coding

Code Excited Linear Predictive Coding is a speech coding algorithm. CELP coders use codebook excitation, a long-term pitch prediction filter, and a short term format prediction filter.

Center SR3 Frequency

The Center SR3 Frequency is the Spreading Rate 3 frequency that has the center frequency assignment

CEPT - Conference des administrations Europê des Poste set Telecommunications

Conference des administrations Europê des Poste set Telecommunications is the organization, that has been superseded by ETSI (European Telecommunications Standards Institute).

CET - Carrier Ethernet Transport

CET is the general term which encompasses the options available for implementation of a network that supports Carrier Ethernet services. Examples of suitable transport technologies include those based on Ethernet, MPLS and optical transmission.

CF

CF may be implemented as either a SS or CAMEL service in which the call for an intended recipient is forwarded onto a designated number. This may be within, or outside the subscribers HPLMN.

CF - Candidate Frequency

The candidate frequency is either an analog or CDMA (Code Division Multiple Access) based frequency, for which the BS (Base Station) specifies a search set, using a Candidate Frequency Search Request Message.

CFB - Ciphertext Feedback

This is similar to CBC (Cipher Block Chaining) but does not depend on the requirement for a full block before encryption can take place since it uses a register shift to generate the full block of data needed for the encryption operation.

CFI - Control Format Indicator

The CFI is a parameter used on the LTE air interface. It defines the number of symbols in each subframe allocated to PDCCH. The CFI takes values CFI = 1, 2 or 3 OFDM symbols.

CFNRc - Call Forwarding on mobile subscriber Not Reachable

A cellular supplementary service in which the incoming call is forwarded to a third party when the intended party is not reachable.

CFNRy - Call Forwarding on No Reply

A cellular supplementary service in which the incoming call is forwarded to a third party when there is no reply from the intended party.

CFP - Contention Free Period

The term CFP is used in wireless networks supporting the IEEE 802.11 standard. It defines a period of time during which access to the Wireless Medium is free of contention. As such, this is controlled by both the PCF and HCF.

CFRI - Contention Free Repetition Interval

This term is used in WiFi networks and specifies the time interval between Contention Free periods. These typically take place immediately after the Beacon message.

CGF - Charging Gateway Function

The CGF forms part of a mobile service providers billing domain, designed to translate CDRs generated by the network into a format suitable for the billing system.

CGI - Cell Global Identity

The Cell Global Identity is the concatenation of the LAI (Location Area Identity) and the CI (Cell Identity) and uniquely identifies a given cell.

Channel Coding

Channel coding may be a combination of error detection, error correction, rate matching, interleaving and transport channel mapping onto/splitting from physical channels.

CHAP - Challenge/Handshake Authentication Protocol

Challenge/Handshake Authentication Protocol is a system for determining if a user has the correct password without openly revealing that password. CHAP does not itself prevent unauthorized access; it merely identifies the remote end. The NAS (Network Access Server) application then determines whether that user is allowed access to the protected resources.

Chargeable Event

An activity utilizing telecommunications network infrastructure and related services for user-to-user communication (e.g., a single call, a data communication session or a short message), or for user to network communication (e.g. service profile administration), or for inter-network communication (e.g. transferring calls, signalling, or short messages), or for mobility (e.g. roaming or inter-system handover), which the network operator wants to charge for. The cost of a chargeable event may cover the cost of sending, transporting, delivery and storage. The cost of call related signalling may also be included.

Checksum

A checksum is a method for checking the integrity of transmitted data. A checksum is an integer value computed from a sequence of octets taken through a series of arithmetic operations. The value is recomputed at the receiving end and compared for verification.

CHF - Charging Function

The 5G Charging Function forms part of the 3GPP’s Converged Charging System, which encompasses support for both prepaid and postpaid billing within the same charging system.

Chirping

This is a spread spectrum method, in which the transmitter sweeps across a given frequency band.

CHP - Charging Point

The time at which charging commences. This is usually the point when the called party answers the call.

CI - Cell Identity

The cell identity is a 16bit identifier in GSM and UMTS. When combined with the LAI (Location Area Identity) or RAI (Routing Area Identity) the result is termed the CGI (Cell Global Identity).

CIC - Circuit Identity Code

The Circuit Identity Code is used to identify the trunk circuit to be connected. This variable is also used to associate the ISUP (ISDN User Part) messaging with a particular circuit. The CIC is an 8bit field within the SIF (Service Information Field) of the ISUP message. The coding of the CIC differs slightly between European and North American standards.

CID - Charging Identity

In 3GPP networks, the CID is used for billing correlation. For every EPS bearer established as part of a specific PDN connection, the P-GW will create a CID and distribute it to the S-GW or SGSN as appropriate.

CIDR - Classless Inter Domain Routing

CIDR was a technique introduced in the 1990s which was designed to reduce the consumption rate of IPv4 addressing, whilst helping to keep routing table sizes minimal. The system replaced the classful addressing system which was originally used to allocate IPv4 addresses. Instead, CIDR permits a variable length network ID, ensuring that end networks receive a network prefix appropriate to their size.

CINR - Carrier to Interference plus Noise Ratio

CINR is a measurement of signal effectiveness which is expressed in Decibels. In order for a receiver to correctly process a received signal, the CINR of that signal must be at the correct CINR level.

CIoT - Cellular Internet of Things

This is a generic term to describe a number of cellular based technologies supporting IoT (Internet of Things) operation. Examples include EC-GSM-IoT (Extended Coverage – GSM – Internet of Things), LTE-M (Long Term Evolution – Machines) and NB-IoT (Narrow Band – Internet of Things).

Ciphertext

Ciphertext is the term given to user data (known as Plaintext), that has been protected by an encryption system.

CIR - Committed Information Rate

CIR is a component of the bandwidth profile traffic parameters applicable to a service running over Ethernet networks. It is the maximum sustained information rate the network is committed to transfer. This is achieved while meeting the performance level guaranteed in the SLA. Three performance metrics (FD, FDV and FLR) are applicable only to those frames that are transmitted at or below the CIR.

Circuit Switching

Circuit switching is a process in which a dedicated physical circuit path must exist between sender and receiver for the duration of the call. The switch is employed to connect the various physical paths that make up the end to end connection. Switching takes place within Layer 2 of the OSI (Open System Interconnection) 7 layer model.

CK - Cipher Key

This is a 128bit number derived in the authentication process and used for the encryption of the RB (Radio Bearer) in UMTS.

CKSN - Cipher Key Sequence Number

The Cipher Key Sequence Number is used in key management in a GSM system. Since the Kc (cipher key) is dynamically generated through the authentication process some mechanism to ensure key consistency is required. The CKSN is employed to achieve this. If encryption is used there is no requirement to authenticate the user for every call. It is possible to refer to previously used cipher keys already generated in the network. The CKSN is used to refer to these keys.

Class A Terminal

In a GSM and UMTS system a class A mobile may be attached to both PS (Packet Switched) and CS (Circuit Switched) services. The mobile supports simultaneous attach, simultaneous activation, simultaneous monitor, simultaneous invocation and simultaneous traffic. The mobile user can make and/or receive calls on the two services simultaneously subject to the QoS requirements.

Class B Terminal

In a GSM and UMTS system a class B mobile may be attached to both PS (Packet Switched) and CS (Circuit Switched) services, but the mobile can only operate one set of services at a time. When the mobile is in both idle mode (UMTS and GSM) and packet idle mode ( GPRS ) it should be able to monitor paging channels for both circuit switched and packet switched services depending on the mode of network operation.

Class C Terminal

In a GSM and UMTS system a class C mobile is attached to either PS (Packet Switched) or CS (Circuit Switched) services, allowing alternate use only. If both services (PS and CS) are supported then a Class C mobile can make and/or receive calls only from the manually or default selected service, i.e., either Packet Switched or Circuit Switched service.

Classmark

Classmark Mobiles when communicating to the network will initially indicate their classmark, this includes service, equipment and radio capabilities.

CLI - Calling Line Identity

An ISDN function used to provide information to the user regarding the calling party address. This is sometimes referred to as CLID.

CLID - Calling Line Identification

CLID is a service used in telecommunications networks which informs a called party who the calling party is during the ringing process, before the called party answers the telephone.

Client

A client is a node or software program that requests services from another node or software program. The node or software providing the service is termed the server. These processes are termed client/server functions.

CLIP - Connected Line Identification Presentation

A supplementary service enabling the called party to receive the line identity of the calling party.

CLIR - Connected Line Identification Restriction

A supplementary service enabling the calling party to restrict the identity of the line on which they are calling.

CLK - Clock

In a Bluetooth piconet the master device CLK (Clock) typically defines the timing.

CLKE - Clock Estimate

Clock Estimate is a Bluetooth slave device estimate of the master device clock. It is used to synchronize the slave device to the master device.

Closest Match Routing

This process is used by routing functions in order to identify the address portion that should be used to route the incoming IP datagram. The routing table record that most closely matches the destination address is used to forward the packet.

CLP - Cell Loss Priority

An ATM (Asynchronous Transfer Mode) message used to indicate if a cell may be discarded from the network due to congestion. This bit will be set on the UNI (User to Network Interface) if data being introduced to the network does not conform to the traffic contract.

CM - Connection Management

A function for the control, provision and maintenance of services offered by the network; for example, SMS (Short Message Service), teleservices and location-based services.

CMAC - Cipher Message Authentication Code

CMAC is a keyed hash function which is based on a symmetric key block cipher rather than a cryptographic hash, as in the case of HMAC (Hashed Message Authentication Code).

CMAS - Commercial Mobile Alert Service

CMAS is a PWS (Public Warning System) developed for the delivery of multiple, concurrent warning notifications.

CMD - Command

A message sent to invoke an action by a receiving entity.

CMIP - Client Mobile IP

CMIP is the opposite to PMIP (Proxy MIP). With CMIP, the mobile device supports a MIP stack and interacts with Mobility Agents in the home and foreign network.

CMM - Channel Mode Modify

A message sent to modify the characteristics of the current channel.

CMP - Certificate Management Protocol

The processes involved in PKE (Public Key Encryption) are defined in the CMP (Certificate Management Protocol). The original process was specified by the PKIX (Public-Key Infrastructure (X.509)) Working Group under RFC 2510. A new, more robust, management protocol is under consideration by the IETF (Internet Engineering Test Force) and is known as CMPv2.

CMR - Codec Mode Request

The CMR is part of the RTP (Real time Transport Protocol) Payload Header which is used in the transportation of AMR (Adaptive Multi Rate) speech samples. CMR (Codec Mode Request). The CMR field is used to indicate to the receiver of the RTP stream how the transmitter wishes future speech frames to be encoded. This may typically be sent from a wireless gateway, interfacing with a mobile network.

CN - Core Network

This is an evolved GSM Core Network infrastructure or any new UMTS Core Network infrastructure, integrating circuit and packet switched traffic. This may include such functions as the MSC (Mobile Switching Centre), VLR (visitor Location Register), HLR (Home Location Register), SGSN (Serving GPRS Support Node) and GGSN (Gateway GPRS Support Node).

CNC - Central Network Controller

The CNC is a functional element of a TSN (Time Sensitive Networking) deployment which provides configuration data to TSN bridges in response to TSN Flow requests received from the CUC (Centralized User Configuration).

CNG tone

A tone generated either in the handset or the network to indicate that the call is in progress. This tone is used as a comfort tone for users.

CoA - Care of Address

In Mobile IP, the CoA is the temporary IP address that is allocated by the foreign network, allowing the Home Agent to forward packets to the device even though it is on a different network.

CoD - Confirmation of Delivery

A notification sent by the receiving LAC (Link Access Control) Sublayer to the Layer 3 sending entity. This acknowledgement process forms part of the procedure for sending PDU (Protocol Data Unit) in AM (Assured Mode).

Code Channel

The Code Channel is a subchannel of a Forward CDMA Channel or Reverse CDMA Channel. Each sub-channel uses an orthogonal Walsh function.

Code Symbol

A Code Symbol is the output of an error-correcting encoder. Information bits are input to the encoder and code symbols are output from the encoder.

Codebook

For each subframe of speech, one particular vector is chosen from the codec codebook and used to excite the speech codec’s filters. The codebook vector is chosen that minimizes the difference between the original speech sample and synthesized output.

Codec - Coder

A device used to transform analogue signal samples into digital bit words and back again.

COM - Complete

A message sent by the receiving entity to indicate the signalling process has been successfully completed.

Combinational Code

A combinational code is the combination of two pseudorandom codes.

Common Power Control Sub channel

A sub channel used by the BS (Base Station) to control the power of a MS (Mobile Station) when operating in the Power Controlled Access Mode on the Enhanced Access Channel or when operating in the Reservation Access Mode or the Designated Access Mode on the Reverse Common Control Channel.

Community Strings

Passwords used by SNMP (Simple Network Management Protocol) to remotely manage network devices.

Companding

Companding, means compression and expansion of a signal or sample. It forms part of the PCM (Pulse Code Modulation) process, whereby analogue signal values are logically rounded on a nonlinear scale. The decimal step number is then coded to its binary equivalent prior to transmission. The process is reversed at the receiving terminal using the same nonlinear scale.

Compression

Reducing the representation of the information, but not the information itself. Compression is accomplished by running a data set through an algorithm that reduces the space required to store, or the bandwidth required to transmit the data set.

CONF - Conference

A supplementary service associated with conference calling services.

Conference Factory

An IMS (IP Multimedia Subsystem) user agent that wants to create a conference forwards a SIP (Session Initiation Protocol) INVITE request towards the S-CSCF (Serving – Call Session Control Function) which acts as the conference-factory URI (Uniform Resource Indicator). This means it coordinates the establishment of a conference and will supply the actual conference URI to the user once it has been generated. In doing so, the services of the MRFC may be employed.

Confidentiality

Confidentiality, when applied to data security may either be associated with the data (plain text) being transferred, or to both the plain text and the identity of the sending and receiving parties; namely the source and destination IP addresses, which is known as traffic flow confidentiality. When IPSec (IP Security) is employed to provide confidentiality, ESP (Encapsulation Security Payload) is used to protect user data. To provide traffic flow confidentiality, ESP is also used. In this case however, IPSec tunnel mode is implemented.

Configuration Change Indicator

A one bit datum, sent on the Quick Paging Channel. Appearance of the Configuration Change Indicator in the Quick Paging Channel serves to alert a slotted mode MS (Mobile Station), operating in the idle state, that, after performing an idle handoff, it should monitor the Paging Channel, the FCCCH (Forward – Common Control Channel), or the Primary Broadcast Control Channel in order to determine if it should update its stored parameters.

CONNACK - Connect Acknowledgement

A message sent by the receiving entity to acknowledge the connect indication.

Connectable Device

A Bluetooth device that is in range and will respond to a paging message and setup a connection is known as a connectable Device

Connected mode

Connected mode In this mode there is one UMTS RNC (Radio Network Controller) that is acting as SRNC (Serving RNC), and an RRC (Radio Resource Control) connection is established between the UE (User Equipment) and this SRNC.

Conversational Service

An interactive service which provides for bi-directional communication by means of real-time (no store -and-forward) end-to-end information transfer from user to user.

Convolutional Code

A Convolutional Code is a type of forward error correcting code. Typically these can be either half rate or third rate codes. Half rate codes in effect double the data to be sent, the extra overhead being used in the forward error correction process. Third rate codes triple the data required to be sent but provide more robust error correction.

COPS - Common Open Policy Services

COPS is a mechanism which allows endpoints to negotiate with networks for resources based on pre-agreed policy. COPS uses two basic elements to control which resources the subscriber receives, namely the PDF (Policy Decision Function) and the PEF (Policy Enforcement Function). The PDF holds subscriber information and will notify the PEF as to whether or not a subscriber should be allowed the requested resources.

CORBA - Common Object Request Broker Architecture

Common Object Request Broker Architecture is a standard defined by the Common Object Group. It is a framework that provides interoperability between objects built in different programming languages, running on different physical machines perhaps on different networks. CORBA specifies an Interface Definition Language, and API (Application Programming Interface) that allows client / server interaction with the ORB (Object Request Broker).

CoS - Class of Service

Class of Service is used to identify a particular group of traffic characteristics that may be applied to a traffic flow. All packets fitting those characteristics are handled based on that class of service. A typical policy employing class of service is the IETF (Internet Engineering Task Force) DiffServ (Differentiated Services) Architecture.

COTS - Commercial Off The Shelf

COTS is a term given to the processing/network hardware that is delivered to the customer with no preinstalled software. For example, COTS servers can be used in an NFV (Network Functions Virtualization) deployment in order to provide the processing power of the NFVI (NFV Infrastructure).

COUNT - Call History Parameter

A modulo 64 event counter maintained by the MS (Mobile Station) and AC (Authentication Center) that is used to combat fraud such as cloning.

Coverage area

Coverage area defines the geographical area where devices can exchange messages with acceptable quality and performance.

CP - Connection Protocol

An SMS protocol layer which provides reliable delivery of the SMS between the mobile and the network (MSC).

CP - Contention Period

The term CP is used in wireless networks supporting the IEEE 802.11 standard. It defines a period of time during which access to the Wireless Medium is contention based. As such, this is controlled by both the DCF and HCF.

CP - Cyclic Prefix

In OFDM systems, a CP (Cyclic Prefix) can be used to counter the effects of multipath propagation. This can be represented as a guard period which is located just in front of the user data portion and as such, is able to mitigate Delay Spread. The CP is in fact the final part of the OFDM Symbol copied and placed in front of the same OFDM symbol.

CP-OFDM - Cyclic Prefix – Orthogonal Frequency Division Multiplexing

CP-OFDM is used as the access technology for 5G New Radio. Its operation is very similar to that of OFDM used in LTE, however CP-OFDM features variable subcarrier spacing termed “numerology”. Where LTE uses a fixed 15kHz subcarrier separation, CP-OFDM can utilize 15kHz, 30kHz, 60kHz, 120kHz, etc. When the subcarrier spacing is changed, the cyclic prefix duration per symbol also changes.

CPCH - Common Power Control Channel

A forward common channel which transmits power control messages to mobiles. The Common Power Control Channel is used by a MS (Mobile Station) operating in the Power Controlled Access Mode, Reservation Access Mode, or Designated Access Mode.

CPCS - Common Part Convergence Sublayer

A generic sublayer used to format higher layer PDU (Protocol Data Unit) for use by a specific traffic technology. A typical user of a CPCS is ATM (Asynchronous Transfer Mode).

CPE - Customer Premises Equipment

CPE is the generic title given to network equipment that is located at the customer premises. A typical example of this would be a DSL modem, although alternatives include VPN termination equipment, ingress routers, switches and PABX systems.

CPG - Call Progress

An ISUP (ISDN User Part) signalling message sent in either direction during the active or set-up phase of the call indicating that an event of significance has occurred eg. ringing call forwarded.

CPH - Call Party Handling

CAMEL Phase 4 offers the ability to perform CPH which is the ability to manage the various parties participating in a call. Aspects of the CAMEL call modelling/processing are enhanced to allow the various parties to be added deleted joined and/or separated from the other parties involved in the call.

CPICH - Common Pilot Channel

This channel is used in UMTS to enable channel estimation. The CPICH uses a pre defined bit sequence. It has a fixed rate of 30Kbps with a SF (Spreading Factor) of 256. This allows the UE (User Equipment) to equalize the channel in order to achieve a phase reference with the SCH (Synchronisation Channel) and also allows estimations in terms of power control. The same channel code is always employed on the Primary CPICH.

CPIM - Common Profile for Instant Messaging

CPIM was introduced as an interworking technique to allow instant messaging services utilizing different protocols to interwork with one another. As such, CPIM defines the semantics and data formats for common services of instant messaging to facilitate the creation of gateways between instant messaging services.

CPM - Converged IP Messaging

An IMS based messaging service standardized by the OMA which offers a variety of messaging services, such as 1 to 1, group chat, multimedia and file transfer.

CPRI - Common Public Radio Interface

CPRI is an open standard related to the internal interface of base stations between the radio control component and the actual radio equipment itself. It was jointly created through a cooperative comprising of leading equipment vendors, including Ericsson, Huawei, NEC and Nortel. CPRI facilitates connectivity in CRAN deployments by providing interconnectivity between the centralised unit and the decentralised units. Further information is obtainable via www.cpri.info.

CPU - Call Processing Unit

The CPU is an integral part of a PSTN switch. The role of the CPU is to receive and process elements of SS7 (Signalling System number 7) signalling such as the called number in order to establish appropriate resources and facilitate circuit cross connection.

CQI - Channel Quality Indicator

In the LTE system, the CQI is used by the mobile to indicate the channel quality to the eNB. The CQI reported value is between 0 and 15. This indicates the level of modulation and coding the UE could operate.

CR - Certification Request

Companies, through their RA (Registration Authority), or individuals, must request a digital certificate from a CA (Certification Authority). The request contains a public key and additional identity information. The CA will first investigate the validity of the request, and if successful will sign the public key, along with other variables presented by the party making the request. Once the certificate is signed, it may be used in the PKI (Public Key Infrastructure).

CRC - Cyclic Redundancy Code

A linear error code that is generated using a polynomial function on the data to be sent, the remainder from the process being the CRC. This is sent along with data so that a parity check of the received data can be conducted.

CRI - CSI-RS Resource Indicator

This is used by LTE-Advanced and 5G devices to indicate the preferred beam, i.e. as part of FD-MIMO and Massive MIMO.

CriC - Critical Communications

Critical Communications is a key part of 3GPP 5G SMARTER (Services and Markets Technology Enablers). The study started in 2015 and looked at potential 5G requirements, which resulted in more than 70 different use cases, grouped into CriC (Critical Communications), MIoT (Massive Internet of Things), eMBB (Enhanced Mobile Broadband) and Network Operation.

CRL - Certificate Revocation List

Digital Certificates are only valid for a specified period; if, after this period, they are not renewed by the owner they are revoked. Revocation may also be applied to certificates that may have been compromised. All revoked certificates are listed and may be viewed through the CA (Certification Authorities) web site. These lists are issued on a regular basis by the CA, and prior to a dialogue being established between end parties this list should be checked to ensure the integrity of the parties involved in the communication.

CRNC - Controlling RNC

The Controlling Radio Network Controller is the RNC (Radio Network Controller) responsible for the configuration of a Node B. A UE (User Equipment) accessing the system will send an access to a Node B, which in turn will forward this message onto its CRNC.

CS - Circuit Switched

Identifies the circuit switched domain and the use of circuit switched data.

CS-RNTI - Configured Scheduling – RNTI

This identifier is used in 5G as part of CS (Configured Scheduling) resource allocation. It enables RRC to defines the periodicity of the CS grant using the CS-RNTI. This resource can then be implicitly reused according to the periodicity defined by RRC.

CSA - Call Segment Association

The process of controlling Call Party Handling involves managing call segments which contain one or more call legs. The call parties in the same call segment can communicate with each other with this typically being achieved using a conference bridge. The gsmSCF uses a single CAP dialogue to control a CSA which contains one or more call segments.

CSC - Communication Service Customer

A CSC is terminology related to network slicing, describing the customer who utilizes the network slice which is providing the communication service.

CSCF - Call Session Control Function

A SIP proxy device found within the 3GPP IMS which can undertake a variety of different roles, such as Proxy CSCF, Interrogating CSCF, Serving CSCF and Emergency CSCF.

CSE - CAMEL Service Environment

The CSE describes the CAMEL environment in terms of the service creation environment and the nodes within the network that interact to deliver services to the subscriber.

CSFB - Circuit Switched Fallback

A mechanism introduced to allow subscribers on a 4G network to make and receive voice calls. In essence, when a Mobile Originated / Terminated call needs to take place, the subscriber will leave the 4G network and fall back to the 2G/3G network in order to make or receive the call.

CSG - Closed Subscriber Group

Introduced in the 3GPP Release 8 specifications, a Closed Subscriber Group is used to describe a specific group of mobiles who are permitted access to a Femto Cell. As a CSG-ID is broadcast from the Femto Cell in the SIB 2 message, only those mobiles who are members of this group will attempt to select the cell.

CSI - CAMEL Subscription Information

The contents of the CSI include: gsmSCF Address – this is the identity of the CSE (CAMEL Service Environment) to be used for service interaction i.e. the gsmSCF. It is made up of a global address enabling visited networks to identify the gsmSCF and route signalling accordingly. Service Key – the CSI also contains information related to the OSS of the subscriber and is termed the Service Key. This is used to identify the service logic to be used by the gsmSCF. It is administered by the HPLMN and is passed transparently by the VPLMN / IPLMN to the gsmSCF. Default Call Handling – this indicates whether the call shall be released or continued when there is an error in the dialogue between the gsmSSF and gsmSCF. An example of this maybe when the requests from the gsmSSF are not acknowledged by the gsmSCF despite repeated re-transmissions. Each Service Key has a default call handling setting associated with it. TDP (Trigger Detection Point) List – this indicates at which detection point CAMEL triggering will take place.

CSI-RS - Channel State Information – Reference Signal

This is a term used for LTE-Advanced and 5G systems. The CSI-RS is typically associated with a beamforming FD-MIMO or Massive MIMO transmission.

CSICH - CPCH Status Indicator Channel

The CPCH Status Indicator Channel is a fixed rate (spreading factor 256) physical channel used to carry CPCH (Common Packet Channel) status information.

CSL - Component Sublayer

The Component Sublayer is the upper layer of TCAP (Transaction Capabilities Application Part). The CSL defines the actual messages or components that are contained in the TSL (Transaction Sublayer Messages).

CSMA - Carrier Sense Multiple Access

CSMA is a technique used by devices which utilize a shared medium for communication. These devices, often termed nodes, will listen to the medium to try and detect the presence of a carrier signal. A carrier signal being present indicates to the listening device that another node is currently using the medium, therefore the listening node will not attempt to transmit.

CSMA/CA - Carrier Sensing Multiple Access / Collision Avoidance

This is the medium access control method employed in IEEE 802.11 wireless networks. The IEEE 802.11utilizes collision avoidance rather than collision detection which is used in wired systems such as IEEE 802.3 and Ethernet. Unlike these conventional wired networks, a WLAN Station cannot detect a collision while transmitting as it operates in half duplex. If a collision occurs, the transmitting Station will not receive an acknowledgement from the intended receive Station. For this reason, acknowledgement packets have a higher priority than all other network traffic. Once all data transmission has been completed, the receive Station will transmit an acknowledgement before any other node can begin transmitting a new data packet. All other Stations must then wait for a longer period of time before they may begin transmission.

CSMA/CD - Carrier Sense Multiple Access with Collision Detection

This is a MAC (Medium Access Control) technique used on an Ethernet LAN (Local Area Network) which is a shared collision domain. The technique requires all network devices to monitor the carrier to determine whether there is any traffic being sent prior to transmitting their information. Should two devices transmit at the same time, they will back off and wait for a time (randomly generated) prior to attempting to re-transmit the information.

CSMF - Communication Service Management Function

With respect to network slicing, the CSMF is responsible for generating allocation requests for new Network Slice Instances. In this capacity, the CSMF is functioning as an NSMS-C (Network Slice Management Service – Consumer).

CSP - Communication Service Provider

With respect to network slicing, a CSP is responsible for providing one or more communication services to a CSC (Communication Service Customer).

CSPDN - Circuit Switched Public Data Network

A general wide area network used to provide circuit switched data services for commercial users.

CSPF - Constrained Shortest Path First

CSPF is the term given to a shortest path routing algorithm which factors in a number of constraints to its routing calculation. Using CSPF means that a network administrator can ensure the SPF routing algorithm, for example, only considers routes able to support 100Mbps traffic throughput or routes with a particular end to end delay. Popular shortest path routing protocols such as OSPF (Open Shortest Path First) and IS-IS (Intermediate System to Intermediate System) have both been extended to support constraint based routing.

CSRC - Contributing Source

CSRC is an RTP (Real-time Protocol) variable that is used to indicate the sources from behind a mixing function. This mixing function is used to combine streams before they are played to the end user.

CSRN - CS domain Routing Number

Used in order to support IMS Centralized Services, the CSRN will be used during a mobile terminated call set up procedure in order to route the call from the IMS core to the MSC-S responsible for the Called Party (within the CS domain).

CT - Call Transfer

A supplementary service in which a call intended for a user is passed to a different number or extension.

CT - Class Type

The term CT is used when describing MPLS Diffserv aware Traffic Engineering. CT is used for the purpose of link bandwidth allocation, constraint based routing and admission control. For example, CT 1 may define a class of traffic associated with low latency requirements. That CT will be allocated a specific amount of bandwidth on the link. That portion of bandwidth will be populated by LSP (Label Switched Path) of CT 1 only. If the bandwidth of CT 1 is fully utilized, further attempts to set up LSP supporting CT 1 traffic will fail.

CTCH - Common Traffic Channel

This is a point to multipoint unidirectional channel for the transfer of dedicated user information for all or a group of specified UE (User Equipment).

CTF - Charging Trigger Function

The CTF is a network node which will generate charging events based on network resource consumption by a subscriber. Examples of network nodes which can contain a CTF include an SGSN, P-GW, ePDG, etc.

CTR - Connect To Resource

CTR message is associated with CAMEL services that require gsmSRF interaction. The CRT message is passed from the gsmSCF to the gsmSSF when the gsmSRF is collocated with the gsmSSF.

CTS - Clear To Send

This is a signalling message transmitted by an IEEE 802.11 Station in response to an RTS (Request to Send) message. The CTS message silences all wireless Stations in its vicinity and enables the sender of the RTS message to begin data transfer.

CUC - Centralized User Configuration

The CUC is a logical function which receives requests for TSN (Time Sensitive Networking) Flow establishment from TSN endpoints. In turn, the CUC will pass configuration data related to the TSN Flow to the CNC (Central Network Controller) for instantiation.

CUG - Closed User Group

A Closed User Group is a supplementary service offered by network operators. It allows the creation of logical groups of users within the operator’s network.

CUG Index - Closed User Group Index

A code used to select a CUG for outgoing calls.

CVSD - Continuous Variable Slope Delta Modulation

Bluetooth uses a 64Kbps CVSD (Continuously Variable Slope Delta) modulation scheme to code the voice. It is also possible to use standard 64Kbps PCM (Pulse Code Modulation) if required. CVSD takes advantage of the fact that human voice signals do not change rapidly and hence there is only a small change between samples.

CW - Communication Waiting

A supplementary service indicating to a user currently in call that another caller is waiting.

CW - Contention Window

This is a term used in IEEE (Institute of Electrical and Electronics Engineers) 802.11 networks which are supporting the QoS (Quality of Service) enhancements originally defined in the 802.11e standard. It defines a period of time in which the network is operating in contention mode.

CWDM - Coarse Wave Division Multiplexing

CWDM is the term given to the practice of multiplexing up to eight wavelengths of light down the same piece of optical fibre. This in effect multiplies the capacity of the fibre by eight, since each wavelength can support a separate data stream.

D Link - Diagonal link

A Diagonal link connects a secondary (e.g., local or regional) STP (Signalling Transfer Point) pair to a primary (e.g., inter-network gateway) STP pair in a quad-link configuration. Secondary STPs within the same network are connected via a quad of D links. The distinction between a B link and a D link is rather arbitrary. For this reason, such links may be referred to as B/D links.

D-channel - Data channel

The D channel is a full duplex, 16Kbps BRI (Basic Rate Interface) or 64Kbps PRI (Primary Rate Interface) ISDN channel used to carry control signals and customer call data in the packet switched mode.

D-IM-CSI - Dialled – IP Multimedia – CAMEL Subscription Information

D-IM-CSI is used in a similar way to the O-CSI. The main difference is the O-CSI has a TDP List which when triggered initiates a dialogue with the gsmSCF and IM-SSF. The D-CSI on the other hand always uses DP2 and it is this criterion associated with the DP that dictates which gsmSCF the IM-SSF will initiate a control dialogue with. Thus, by setting multiple D-CSI it is possible to trigger a dialogue with one of a number of gsmSCF.

D2D - Device to Device

D2D is a service which allows LTE devices in close proximity to one another to communicate directly. This type of technology is particularly useful for LTE Public Safety applications.

DA - Destination Address

The DA is a term frequently used in the networking realm to signify the recipient of a piece of data. The DA could be in the form of a Layer 2 MAC (Medium Access Control) Destination Address and identify the NIC (Network Interface Card) of the intended recipient or a Layer 3 IP Destination Address and identify a particular host on a network.

DAB - Digital Audio Broadcasting

DAB is the technology behind digital radio transmission, employed in numerous countries around the world since 1999 (DAB is also termed Eureka 147). DAB uses techniques such as OFDM and convolutional coding, in conjunction with the MPEG1 Audio Layer 2 codec (MP2), to provide a service that is reported to be less susceptible to interference. In 2006, DAB+ was introduced as a non-backwards compatible upgrade to DAB. DAB+ utilizes the AAC for improved audio encoding.

DAC - Device Access Code

The Device Access Code is used during the Bluetooth page, page scan and page response procedures. This code is derived from the devices BD_ADDR (Bluetooth Device Address).

DAMPS - Digital Advanced Mobile Phone Service

With the initiative to increase the capacity and quality of AMPS (Advanced Mobile Phone Service) some of the AMP’S channels were digitized in the DAMPS system. The broadcast channels remained analogue were shared between AMPS and DAMPS. Consequently, the DAMPS handsets needed to operate in dual mode. DAMPS operates in the 900MHz area of the spectrum.

Dark Web

The Dark Web equates to approximately 7% of the overall World Wide Web. The Dark Web features websites that are associated with illegal activity, although it is important to note that many websites within the Dark Web are there simply for anonymity/privacy purposes and may be perfectly legal. The websites of the Dark Web are often accessible as Tor Hidden Services, which means that both the individual accessing the website and the website itself will use Tor in order to maintain anonymity.

DARPA - Defense Advanced Research Project Agency

Defense Advanced Research Project Agency originally laid out the protocol architecture for today’s public Internet including the development of IP (Internet Protocol), TCP (Transport Control Protocol) and the TCP/IP protocol suite

dB - Decibel

The Decibel is a unit of comparison, in which the ratio of two power values are expressed using a logarithmic scale usually to the base 10. Although the dB is a unit of comparison it is sometimes useful to have an agreed reference point. A common reference is 1mW, which is expressed as 0dBm. Consequently 2W, the typical maximum power of a GSM handset, is rated as 33dBm.

dBc.

A ratio in Decibels of the sideband power of a signal, measured in a given bandwidth at a given frequency offset from the centre frequency of the same signal, to the total in band power of the signal.

dBm.

A measure of power expressed in terms of its ratio (in Decibels) to one milliwatt.

dBm/Hz

A measure of power spectral density. It provides a ratio of the power in one Hertz of bandwidth, where power is expressed in units of dBm.

dBW

A measure of power expressed in terms of its ratio (in Decibels) to one Watt.

DC - Dead Centre

As part of the FFT (Fast Fourier Transform) process the centre frequency, or DC subcarrier, is not allocated.

DCCH - Dedicated Control Channel (GSM)

These channels are used for signalling between the network and the mobile. They comprise of the SDCCH (Standalone Dedicated Control Channel), the SACCH (Slow Associated Control Channel) and the FACCH (Fast Associated Control Channel).

DCCH - Dedicated Control Channel (UMTS)

A UMTS point to point bidirectional channel that transmits dedicated control information between a UE (User Equipment) and the network. This channel is established through the RRC (Radio Resource Control) connection setup procedure.

DCE - Data Circuit Terminating Equipment

A Data Circuit Terminating Equipment is a terminal device that interfaces between the DTE (Data Terminal Equipment) and a transmission circuit. It is sometimes referred to as Data Communications Equipment.

DCF - Distributed Coordination Function

The Distributed Coordination Function forms the basis of standard CSMA/CA (Carrier Sensing Multiple Access / Collision Avoidance) access within an 802.11 network. The DCF first checks to see if the radio link is free before transmitting and to avoid contention, initiates a random backoff. In some circumstances, the DCF may use the RTS (Request To Send) and CTS (Clear To Send) technique to further prevent collisions.

DCH - Dedicated Control Channel

A portion of a Traffic Channel (Forward or Reverse) that carries a combination of user data, signaling , and power control information.

DCI - Downlink Control Information

The E-UTRA Downlink Control Information is part of the LTE air interface and is used to carry uplink grant, downlink scheduling, uplink power control commands and RACH responses.

DCID - Destination Channel Identifier

The Destination Channel Identifier is used in the Bluetooth system. The purpose of the DCID is to enable the remote side to associate the established L2CAP (Logical Link Controller and Adaptation Protocol) channel with the ongoing call.

DCN - Dedicated Core Networks

DCNs are deployed by mobile service providers to serve specific subsets of subscribers, such as in support of a widescale IoT deployment or a large enterprise customer. The DCN may support multiple RAN types and will consist of regular core network nodes, such as the MME (Mobility Management Entity), S-GW (Serving Gateway) and P-GW (PDN Gateway)

DCOM - Distributed Component Object Model

The Distributed Component Object Model is a protocol that enables software components to communicate directly over a network. Developed by Microsoft and previously called Network Object Linking Embedding, DCOM is designed for use across multiple networks, and is transported typically using Internet protocols such as HTTP ( Hypertext Transport Protocol ).

DCS1800 - Digital Cellular System 1800MHz

Digital Cellular System 1800MHz is a term given to what is now known as GSM1800. This system operates in the 1800MHz region of the frequency spectrum. The paired spectrum is located between 1710MHz and 1785MHz for uplink operation and 1805MHz and 1880MHz for downlink operation. The duplex spacing being 95MHz. This spectrum supports 374 channels.

DDoS - Distributed Denial of Service

This type of attack uses a Botnet in order to facilitate a DoS attack which has many different sources. All members of the Botnet are instructed by a Botnet Controller to launch an attack at a specific target. Due to the large volume of attack sources, the victim may find it next to impossible to mitigate against the attack. Several high profile organizations across the globe have succumbed to a DDoS attack.

DECT - Digital Enhance Cordless Telecommunication

Digital Enhanced Cordless Technology uses the 20MHz of spectrum between 1880MHz and 1900MHz, DECT provides 120 duplex channels to provide wireless speech bearers. Enhancements to this standard now allow data services up to a data rate of 1Mbps to be supported.

Dedicated mode

Dedicated mode In this mode the GSM mobile is allocated a dedicated physical channel.

Deep Web

The Deep Web forms the majority of the information currently stored and accessed using the World Wide Web (the Deep Web constitutes approximately 90% of the World Wide Web). If a website requires a username/password to access specific information on the site, that information can be considered to be part of the Deep Web. Moreover, unlike the Surface Web, the Deep Web is not indexed and referenced by search engines. It is important to note that the majority of information in the Deep Web is mundane and perfectly legal, contrary to many media reports (which often use the term Deep Web interchangeably with Dark Web, each of which are actually different).

Default Router

A default router is the default gateway used by the device to access hosts on other networks. It is also called the default gateway.

DES - Data Encryption Standard

DES is a symmetric key encryption algorithm that is now widely considered to be insecure for most applications due to the short 56bit key length.

Designated Access Mode

A mode of operation on the Reverse Common Control Channel where the MS (Mobile Station) responds to requests received on the Forward Common Control Channel.

Device Discovery

The Device Discovery procedure allows a Bluetooth device to request and receive information from other Bluetooth devices. The information received includes such parameters as: the Bluetooth device address, clock information, type of device and name of device.

Device Name

The Device Name is a Bluetooth friendly name. It is made available to other devices during device discovery.

DFT - Discrete Fourier Transform

The DFT (Discrete Fourier Transform) is a form of Fourier analysis. It transforms one function into another, which is called the frequency domain representation, or simply the DFT, of the original function(which is often a function in the time domain). In most telecom systems, this means that the number symbols to be transmitted are mapped to the same number of subcarriers, e.g. 12 symbols to 12 subcarriers.

DH - Data-High Rate

The DH (Data High Rate) indicates a Bluetooth ACL (Asynchronous Connectionless Link) data packet type for high rate data. Three types of ACL packets are available for DH, these are the DH1 packet (1 slot), DH3 (3 slot) packet and DH5 packet (5 slot).

DH - Diffie-Hellman Key Exchange

The Diffie-Hellman Key Exchange is the process in which cryptographic keys may be distributed between communicating parties across a public IP network. Diffie-Hellman was considered to be a significant advancement in cryptography and has been adopted in numerous cryptographic processes. In particular, IKE uses Diffie-Hellman key exchange to help establish an IPSec security association.

DHCPv4 - Dynamic Host Configuration Protocol version 4

DHCP is a Client/Server protocol which allows network hosts to automatically receive an IP address allocation from a DHCP Server. The DHCP Server can also provide the host device with additional information, such as the Default Gateway address or P-CSCF address.

DIAC - Dedicated Inquiry Access Code

The Dedicated Inquiry Access Code is used in the Bluetooth Inquiry procedure. It is used for a dedicated group of Bluetooth units that share a common characteristic.

Diameter

The Diameter protocol is intended to provide a framework for any services which require AAA ( Access, Authorization, and Accounting) /Policy support across many networks. Diameter is used in 3GPP networks extensively, particularly within LTE and IMS networks. Key interfaces which use Diameter include S6a, Gx and Rx, amongst many others.

DiffServ - Differentiated Services

DiffServ is a QoS mechanism used within IP networks. In essence, routers are configured with a number of PHBs (Per Hop Behaviours), which dictate a particular forwarding treatment a packet should receive. In turn, packets are marked with a 6bit DSCP (DiffServ Code Point) which, when identified by the router during the routing process, will determine the PHB which must be applied to the packet.

DIFS - DCF Interframe Space

DIFS are found in IEEE 802.11 networks. When the radio link has been free of any traffic for a period greater than the DIFS, Stations may have immediate access to the medium in a contention-based service.

Digital Certificate

Digital Certificates are electronic documents used to validate the end parties or entities employed in data transfer. These certificates are normally associated with X.509 public key certificates, and are used to bind a public key to a recognized party for a specific period of time.

Digital Signature

A digital signature is the process in which a block of data is encrypted with the user’s private key. This data is normally in the form of a digest, generated by passing the sent message through a hashing algorithm such as MD5 (Message Digest 5). Authentication is then performed by the receiving party by first applying the sender’s public key to the signature (proving it came from the expected source) and then comparing the result to the digest of the message (proving that the certificate has not been tampered with).

Disassociation

The term Disassociation is found within an IEEE 802.11 network and identifies the service used to remove any mapping established between an AP (Access Point) and Station.

Discoverable Device

A Discoverable Device is a Bluetooth device that is in range that will respond to an inquiry message.

DL-SCH (LTE) - Downlink Shared Channel

In LTE the DL-SCH (Downlink Shared Channel) is carried by the PDSCH. This is the only downlink transport channel available to carry user data between the mobile device and the eNB.

DL-TFT - Downlink-Traffic Flow Template

In LTE , as part of the Dedicated EPS bearer establishment a DL-TFT and UL-TFT are assigned. The EPS Bearer TFT is the collection of all packet filters associated with that EPS bearer and is used as part of the classification of a packet in order to ensure the correct traffic is sent on the correct bearer.

DLCI - Data Link Connection Identifier

The Data Link Connection Identifier identifies an individual user’s information stream as well as identifying the connections between terminal equipment and the user equipment. It is possible for multiple DLCI to be supported however, the actual number is implementation specific.

DLI - Durham Light Infantry

Durham Light Infantry Infantry regiment in the British Army.

DLP - Direct Link Protocol

The term DLP is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancement. It defines the protocol to enable the transfer of frames between two QSTA supporting power save mode.

DLS - Direct Link Setup

This term describes a protocol used in WiFi networks to optimize the transfer of information between two QSTA (Quality Station) as originally defined in the IEEE 802.11e standard. The need for the protocol was motivated by the fact that the recipient may be in power save mode and as such can only be woken by the AP (Access Point).

DLT - Distributed Ledger Technology

Distributed ledgers are types of databases that are spread across multiple sites, institutions or countries. Records are stored one after each other in a continuous ledger which can either be “permissioned” or “unpermissioned” depending upon who can access it.

DM - Data

The DM (Data Medium Rate) indicates a Bluetooth ACL (Asynchronous Connectionless Link) data packet type for medium rate data. Three types of ACL packets are available for DM, these are the DM1 packet (1 slot), DM3 packet (3 slot) and DM5 packet (5 slot).

DMA - Direct Memory Access

A Direct Memory Access device may access memory without passing messages through the CPU (Central Processing Unit). This significantly increases the processing speed of the system. Typical devices could be a graphics card that may write and read to memory directly.

DMT - Discrete Multi Tone

DMT is a digital modulation scheme based on FDM (Frequency Division Multiplexing). DMT is used across the last mile to support DSL (Digital Subscriber Line) services and is also a popular scheme for wideband digital communication systems such as WiMAX (Wireless interoperability for Microwave Access). DMT is also known as OFDM (Orthogonal Frequency Division Multiplexing).

DMZ - De-Militarized Zone

In network security terms the DMZ refers to the area within a firewall architecture where internal company networks are separated from publicly accessible servers, such as Web servers etc.

DN - Data Network

The Data Network is related to the 3GPP 5G Architecture. It identifies Service Provider services, Internet access or 3rd party services.

DNAI - Data Network Access Identifier

A DNAI will identify the user plane access to one or more Data Networks at which specific applications can be found, particularly in support of MEC (Multi Access Edge Computing).

DNIS - Dialled Number Identification Service

DNIS (Dialled Number Identification Service) is a telephone service that identifies for the receiver of a call the number that the caller dialled. This service is typically used in conjunction with the Freephone service.

DNN - Data Network Name

In 5G, Data Networks are specifically identified using a DNN. The DNN is typically in the form of an APN (Access Point Name).

DNS - Domain Name System

The DNS translates memorable Domain Names/Hostnames into corresponding IP Addresses. Routers across a network route traffic utilising IP Addresses which are unsuitable for use by humans as a means to access websites, email addresses, etc. Instead, more suitable representations in the form of HTTP URL (Uniform Resource Locator) or SMTP email addresses are used. This function is carried out utilising DNS Servers operating in a hierarchical architecture.

Domain Name

A Domain Name is a logical name separated by periods describing a host or virtual host. For example, www.mpirical.com.

DoS - Denial of Service

A DoS (Denial of Service) attack is a generic description of the process of preventing the target of the attack carrying out its normal role. DoS attacks can be directed at network entities such as hosts and servers or alternatively, the network infrastructure itself could be the target. Attack mechanisms are extremely varied, largely due to the fact that the variety of potential targets is also hugely varied. Flooding type DoS attacks are commonplace; for example, the well-known TCP SYN Flood attack sees the target device swamped with TCP SYN messages until its kernel resources are eventually exhausted. Alternatively, a SIP server may succumb to a SIP INVITE flood, which involves large amounts of INVITEs to be directed to the target, ultimately causing the target to fail. Nowadays, Distributed DoS attacks are used as a much more affective DoS attack mechanism.

DOS - Disk Operating System

Computer operating system used to control the microprocessor, and other peripherals such as the computer’s hard disk.

Downlink DPCH

The UMTS system uses the Downlink DPCH (Downlink Dedicated Physical Channel) to carry the DPDCH (Dedicated Physical Data Channel) and the DPCCH (Dedicated Physical Control Channel).

DP - Detection Point

A DP indicates states in basic call and connection processing where control may be transferred to the IN service.

DP Criteria List - Detection Point Criteria List

The DP (Detection Point) criteria indicate conditions that must be met in order for the gsmSSF i.e. SSP (Service Switching Point) to request instructions from the gsmSCF i.e. SCP (Service Control Point). The relevant criteria for mobile terminated calls are typically checked through interaction with the HLR.

DPC - Destination Point Code

Within a SS7 (Signalling System No.7) network the point codes are numeric addresses which uniquely identify each signalling point. The DPC identifies the receiving signalling point.

DPCCH - Dedicated Physical Control Channel

The Dedicated Physical Control Channel is a type of uplink dedicated physical channel. It is an I/Q code, multiplexed within each radio frame. The uplink DPCCH is used to carry the DCH (Dedicated Channel) transport channel. The uplink DPCCH is used to carry control information generated at Layer 1.

DPCM - Differential Pulse Code Modulation

PCM (Pulse Code Modulation) permits adjacent samples to be described from extreme opposite ends of the sample range. As this situation rarely occurs it should be able to convey the baseband data using fewer bits. DPCM allows this to be achieved by describing only the changes between the samples.

DPDCH - Dedicated Physical Data Channel

The Dedicated Physical Data Channel is a type of uplink dedicated physical channel. It is an I/Q code, multiplexed within each radio frame. The uplink DPDCH is used to carry the DCH (Dedicated Channel) transport channel. There may be zero, one, or several uplink DPDCH on each radio link.

DPI - Deep Packet Inspection

A term used to describe the process of packet analysis above the transport layer (Layer 4). DPI can be used in a variety of applications for a number of reasons, including NAT traversal, security and policy enforcement.

DPNSS - Digital Private Network Signalling System

An open standard signalling system developed by British Telecom in order that PABX (Private Automatic Branch Exchange) made by different manufacturers could be integrated. The standard came about as a requirement, when 2Mbps digital links first became available in the early 1980’s.

DQPSK - Differential Quadrature Phase Shift Keying

Differential Quadrature Phase Shift Keying is a modulation technique in which the carrier can assume one of four phases, each change of phase, or symbol, representing 2bits. The bit combinations being 00, 01, 11 and 10. Consequently the data stream can carry 2bits at a time. Using this technique the phase transition across the origin is avoided.

DR - Designated Router

The DR is a function of a broadcast or NBMA (Non Broadcast Multiple Access) network which operates the OSPF (Open Shortest Path First) routing protocol. The DR has two functions, namely: Generation and transmission of Network LSA (Link State Advertisement) for the entire network, thus reducing the amount of routing traffic and Synchronization with all other routers on the network in order to ensure routing information is current and valid.

DRA - Diameter Routing Agent

The DRA enables PCRF (Policy and Charging Rules Function) discovery and selection as part of the PCC architecture. Essentially, if multiple PCRFs are available, the DRA will ensure an appropriate PCRF is initially selected and subsequently ensure that this PCRF is used for all future transactions associated with the subscriber. The DRA is also frequently termed the DRA (Diameter Routing Agency) or DSC (Diameter Signalling Controller). In all cases, the use of the DRA often goes beyond the PCC architecture and is often involved in general routing of all Diameter messages in the network.

DRB - Dedicated Radio Bearer

In LTE there are two main types of bearers, namely the SRB (Signalling Radio Bearer) and the DRB (Dedicated Radio Bearer). The DRB is used to carry the data associated with an EPS bearer.

DRNC - Drift Radio Network Controller

When a UE (User Equipment), in the connected state is handed onto a cell associated with a different RNS (Radio Network Subsystem) it is said to have drifted. The RRC (Radio Resource Control) connection however still terminates with the SRNC (Serving RNC). In effect the DRNC acts as a switch, routing information between the SRNC and the UE.

DRS - Demodulation Reference Signal

In LTE there are two types of uplink reference signals, namely the Demodulation reference signal, associated with transmission of PUSCH or PUCCH , and the Sounding reference signal, not associated with transmission of PUSCH or PUCCH.

DRX - Discontinuous Reception

Discontinuous reception is employed in cellular systems to prolong the mobile’s battery life. The mobile station listens only to the paging channels within its DRX group. Moreover the network will only page the mobile in that group of paging channels. Thus the mobile does not have to continuously monitor the paging channels.

DS - Direct Sequence

A method of achieving a spread spectrum system.

DS - Distribution System

A Distribution System is a logical element of an IEEE 802.11 network which provides the means of connecting multiple AP (Access Points) together. In most commercial AP, the Distribution System is already implemented enabling it to be directly connected to a wired network such as Ethernet etc.

DS PHY - Direct Sequence Physical Layer

The Direct Sequence Physical Layer utilizes spread spectrum technology to transmit the signal over a much wider frequency band. This process entails spreading a narrow band signal over a wider frequency band. To a narrow band receiver, the transmitted signal is impossible to detect as it appears as low level noise. However, a wide band receiver can monitor the whole frequency band and detect changes. The original signal can then be recovered by a correlator which reverses the spreading process. This process gives a significant degree of protection to direct sequence transmissions as noise tends to be narrow in terms of frequency and thus does not affect the entire frequency band. To support the DS PHY, the 2.4GHz ISM (Industrial Scientific and Medical) band is divided into 14 channels, each separated by 5GHz. Unfortunately these channels may not all be available, as different regulatory bodies have allocated different portions of the ISM band.

DSA - Digital Signature Algorithm

The DSA (Digital Signature Algorithm) was developed by the NSA (National Security Association) so that certificates and other information could be signed using the sender’s private key.

DSCH (UMTS) - Downlink Shared Channel

The Downlink Shared Channel is a downlink transport channel that may be shared by several UE (User Equipment). It is used to carry dedicated control or traffic data from the SRNC (Serving Radio Network Controller). The DSCH will be associated with one or several downlink DCH (Dedicated Channel).

DSCP - Differentiated Services Code Point

The 6bit DSCP is appended to the header of an IPv4 or IPv6 packet in order to ensure the packet receives a particular forwarding treatment as it traverses a DiffServ enabled IP network. Different DSCP values will be used to apply different forwarding treatment and as such, a packet must be classified before ingress to the network to make sure that packets are given the appropriate forwarding treatment.

DSF - Data Storage Network Function

The Data Storage Network Function is related to the 3GPP 5G Architecture.

DSL - Digital Subscriber Line

DSL describes a physical layer technology that can be utilized across the last mile connectivity between a customer’s premises and the Local Exchange or Central Office. Typically based on a copper twisted pair transmission medium, DSL can come in a variety of formats. A particular example of this is ADSL2+ , which employs techniques such as DMT between the ATU-R (ADSL Termination Unit – Remote) and the DSLAM.

DSLAM - DSL Access Multiplexer

A DSLAM (DSL Access Multiplexer) is used as an aggregation point for subscriber traffic within DSL systems. It separates the voice frequency signals from the high-speed data traffic and controls, thus routing DSL traffic between the subscriber’s end-user equipment, e.g. router or modem, and the service provider’s network. IP DSLAMs are now being deployed, which provide much of the functionality traditionally found in a B-RAS.

DSMIPv6 - Dual-stack Mobile IPv6

The S2c interface can provide user plane and related control and mobility support between the mobile and the PDN-GW. The interface can be implemented over trusted and/or untrusted non-3GPP access and/or 3GPP access. The protocol over the S2c interface is based on DSMIPv6.The purpose of DSMIPv6 is to establish, manage and tear down a mobility tunnel between the UE and the HA function which resides within the PDN-GW.

Dsp - Delta Session Period

The Dsp is a variable used during the CAMEL Apply Charging Process and is used to record the amount of session time that transpires between the Apply Charging Report sent by the SSF and the subsequent Apply Charging message sent by the SCF.

DSP - Digital Signal Processor

Digital Signal Processors are specialized computer chips designed to perform speedy and complex operations on digitized waveforms. The DSP is used in processing sound, such as voice phone calls, and video.

DSRC - Dedicated Short-Range Communication

DSRC provides short range communications between a vehicle and roadside infrastructure, such as toll road booths facilitating electronic fee collection. The technology operates within the frequency band of 5.9GHz and consists of Road Side Units and On-Board Units with transceivers and responders.

DSS - Digital Signature Standard

DSS (Digital Signature Standard) is the framework laid out by NIST (National Institute of Standards and Technology) for the signing of data prior to transfer. The standard promotes the use of the DSA (Digital Signature Algorithm) public-key algorithm and the SHA-1 hash algorithm.

DSS1 - Digital Subscriber Signalling 1

Access Signalling protocol used between the subscriber terminal and the ISDN network.

DSSS - Direct Sequence Spread Spectrum

Direct Sequence Spread Spectrum is based on the multiplying of the baseband signal data with a broadband spreading code. The result is termed the chip rate. The characteristics of the broadband spreading code are that of pseudorandom noise. Consequently, the receiver synchronized to the code will obtain the narrowband signal. All other receivers will see the spread signal as white or coloured noise.

DTAP - Direct Transfer Application Part

Direct Transfer Application Part is an application protocol used between the 2G mobile and the core network, facilitating the transfer of session management, mobility management and call control signalling associated with procedures such as Network Attach, Location Area Update and Call Establishment.

DTC - Digital Traffic Channel

A term to describe the digital traffic channels employed in systems such as North American digital systems.

DTCH - Dedicated Traffic Channel

Channel A Dedicated Traffic Channel is a point to point channel, dedicated to one mobile for the transfer of user information. A DTCH can exist in both the uplink and downlink direction.

DTE - Data Terminal Equipment

The Data Terminal Equipment is the terminal device and may be a voice or data terminal. The DTE interfaces through a DCE (Data Communications Equipment).

DTI - Destination Transaction Identifier

The DTI is a TCAP variable and is used to associate request and response messages within the TCAP Transaction Sublayer.

DTIM - Delivery Traffic Indication Message

A Delivery Traffic Indication Message may be found in an IEEE 802.11b Beacon Frame which is transmitted from an AP (Access Point). The message is comprised of two parts; DTIM Count and the DTIM Period and indicates that broadcast and multicast frames, buffered at the AP, will be delivered in the near future.

DTM - Dual Transfer Mode

DTM describes the ability of a GSM handset to be able to conduct a voice call and data session simultaneously.

DTMF - Dual Tone Multi-Frequency

System used by touch tone telephones where one high and one low frequency, or tone, is assigned to each touch tone button on the phone.

DTX - Discontinuous Transmission

A pause in the normal flow of conversation is detected in the telephone device, and transmission is suspended. In mobile systems such as GSM and UMTS this serves two purposes. It prolongs battery life and reduces interference in the radio environment.

DV - Data Voice

The DV (Data Voice) indicates a Bluetooth packet which has been defined so it can support both data and voice simultaneously on a single SCO (Synchronous Connection Oriented) link.

DVB-H - Digital Video Broadcasting Handheld

This ETSI standard is an enhancement to the DVB-T architecture which specifies how TV content can be distributed to handheld receivers such as mobile phones and PDA s. The DVB-H standard was published in 2004 and has since seen widespread deployment across the globe, particularly by mobile service providers. DVB-H is a physical layer technology which employs a battery conserving technique termed timeslicing. This involves the mobile only listening for content at set time intervals, in much the same way as a GSM phone would operate with respect to TDMA. In terms of spectrum usage, multiple DVB-H channels occupy a channel which would normally be allocated to one DVB-T channel.

DVRB - Distributed Virtual Resource Block

This is a method for allocating resources in the E-UTRA. As its name suggests, it distributes the scheduled resources in order to improve some aspects of interference.

DWDM - Dense Wavelength Division Multiplexing

The development of erbium doped fibre amplifiers has allowed channel spacing of 0.8nm in the 1550nm range. This enables many more wavelengths to be multiplexed onto a single fibre. In simple terms, DWDM systems shine different colours of light down the optical fibre, with each colour or wavelength capable of conveying a separate datastream. Therefore, a DWDM system with 200 channels would be capable of carrying 200 times the amount of data than a single wavelength fibre.

DwPTS - Downlink Pilot Time Slot

In LTE, the radio frame structure type 2 is used for TDD operation and consists of two half-frames with a duration of 5ms each and containing each 8 slots of length 0.5ms and three special fields ( DwPTS , GP and UpPTS ) which have configurable individual lengths and a total length of 1ms. The DwPTS and UpPTS both provide time which enables downlink/uplink switching to be performed.

DXC - Digital Cross Connect

A Digital Cross Connect is a physical layer device in which digital channels are switched between interfaces.

E Carrier

European term for the TDM (Time Division Multiplexing) digital transmission hierarchy. E1 – 2.048Mbps E2 – 8.448Mbps E3 – 34.368Mbps E4 – 139.264Mbps E5 – 565.148Mbps

E Link - Extended Link

An extended link connects an SP (Signalling Point) to an alternate STP (Signalling Transfer Point). E links provide an alternate signalling path if an SP home STP cannot be reached via an A link. E links are not usually provisioned unless the benefit of a marginally higher degree of reliability justifies the added expense.

E-AGCH - DCH Absolute Grant Channel

The E-DCH Absolute Grant Channel is a downlink physical channel carrying the uplink E-DCH absolute grant information. Key parameters include: Absolute Grant Value and Absolute Grant Scope, as well as individual or group RNTI (Radio Network Temporary Identifier) values which are coded using an identity specific CRC value. There are two types of grants: – Absolute Grants – these provide an absolute limitation of the maximum amount of UL (Uplink) resources the UE may use. These are sent on an E-AGCH. – Relative Grants – these increase or decrease the resource limitation compared to the previously used value. These are sent on an E-RGCH.

E-CSCF - Emergency – Call Session Control Function

The E-CSCF is a specialist platform which is designed to facilitate support for emergency services dialling. In this capacity, the E-CSCF will take in requests from the P-CSCF (Proxy CSCF) and S-CSCF (Serving CSCF) and route these emergency session requests to a suitable onward destination such as a PSAP (Public Safety Answering Point). In order to achieve this, the E-CSCF can use the services of the LRF (Location Retrieval Function).

E-DCH - Enhanced

The E-DCH is an uplink transport channel which is part of the HSUPA specifications. The rate of the E-DCH is controlled by the downlink E-RGCH and E-AGCH.

E-DPCCH - E-DCH Dedicated Physical Control Channel

The E-DPCCH is the uplink physical channel used to transmit control signalling associated with the E-DCH. It contains 10 useful bits of information which includes: – RSN (Retransmission Sequence Number) – 2bits. – E-TFCI (Enhanced – Transport Format Combination Identifier) information – 7bits. – Happy Bit – 1bit.

E-DPDCH - CH Dedicated Physical Data Channel

The E-DPDCH primary role is to carry the HSUPA E-DCH transport channel. Depending on the configuration, there may be zero, one, or several E-DPDCH on each radio link. The rate of the E-DPDCH varies depending on the SF in use. It can vary between SF2 and SF64, which equates to 1.92Mbps and 64Kbps respectively.

E-HICH - DCH HARQ Acknowledgement Indicator Channel

The E-HICH is a downlink channel. As its name suggests, it carries an uplink E-DCH HARQ -ACK (Hybrid-ARQ Acknowledgement) indicator, which is transmitted using 3 or 12 consecutive slots. The 3 and 12 slot duration is used for UE which E-DCH TTI is set to respectively 2 ms and 10 ms. This channel uses the concept of signatures, in a similar way to the AICH (Acquisition Indicator Channel).

E-OTD - Enhanced Observed Time Difference

The E-OTD method is based on measurements in the MS (Mobile Station) of the Enhanced Observed Time Difference of arrival of bursts from nearby pairs of Base Stations. It is employed to calculate the position of the MS and may be used for LCS (LoCation Service).

E-RAB - EPS Radio Access Bearer

An E-RAB (E-UTRAN Radio Access Bearer) refers to the concatenation of an S1 bearer and the corresponding radio bearer. When an E-RAB exists, there is a one-to-one mapping between this E-RAB and an EPS bearer of the Non Access Stratum. Each E-RAB is defined by the following parameters: E-RAB ID – this element is used to identify the E-RAB on the S1 interface. E-RAB QoS – this element describes the QCI (Quality Class Identifier) that defines QoS parameters such as end to end delay, bit error rates etc. Also included are allocation and retention priorities as well as GBR (Guaranteed Bit Rate) parameters if real time services are to be supported over the E-RAB.

E-RGCH - DCH Relative Grant Channel

The E-DCH Relative Grant Channel is very similar to the E-HICH. It is a downlink channel used for carrying the uplink E-DCH relative grants. There are two types of grants: – Absolute Grants – these provide an absolute limitation of the maximum amount of UL (Uplink) resources the UE may use. These are sent on an E-AGCH. – Relative Grants – these increase or decrease the resource limitation compared to the previously used value. These are sent on an E-RGCH.

E-RNTI - Enhanced Radio Network Temporary Identity

This is valid within one cell, and is used by the Node B to identify a UE or group of UE’s. It may also be reallocated when the serving E-DCH cell changes.

E-UTRA - Evolved – Universal Terrestrial Radio Access

The E-UTRA is the air interface (radio) element of the LTE E-UTRAN.

E-UTRAN - Evolved – Universal Terrestrial Radio Access Network

The E-UTRAN is the LTE RAN, forming part of the overall Evolved Packet System.

E1

Wide area digital transmission scheme used predominantly in Europe that carries data at a rate of 2.048Mbps. E1 lines can be leased for private use from common carriers. The E1 contains 32 timeslots at 64Kbps, which can carry voice or signalling traffic.

E164

The format of global switched telephone numbers are defined by the ITU-T (International Telecommunications Union – Telecommunications Standardization Sector) E164 standard. The 16 digit number is split into international, national and user number portions. For example +44 (0) 1344 724666.

E169

E169 defines the format for toll free numbers. The format is defined by the ITU-T (International Telecommunications Union – Telecommunications Standardization Sector) and examples include 800, 888 and 887.

E2

An interim data bearer that consists of four E1 bearers multiplexed together. The capacity of the E2 bearer is 8.448Mbps.

E212

An ITU-T (International Telecommunications Union – Telecommunications Standardization Sector) numbering plan standard, make up of the MCC (Mobile Country Code), MNC (Mobile Network Code) and MSIN (Mobile Station Identification Number). The IMSI (International Mobile Subscriber Number) number of a mobile is an E212 number

E2U - E.143 to URL

The ENUM (E Number) working group of the IETF is defining a name space in which normal telephone numbers may be resolved into URL (Uniform Resource Locator) for use in IP environments. E2U is a NAPTR (Naming Authority Pointer Record) value that identifies such a string.

E3

The E3 standard is specified by ETSI (European Telecommunications Standards Institute). The bearer supports 16 E1 channels giving a capacity of 34.368Mbps.

E4

Carries four E3 channels. The carrier offers a capacity of 139.264Mbps

E5

Carries four E4 channels. The carrier offers a capacity of 565.148Mbps

E911 - Enhanced 911 Service

E911 – Enhanced 911 Service 911 is an emergency telephone number. Enhanced 911 services offer automatic number identification and automatic location information.

EACH - Enhanced Access Channel

A reverse channel used by a mobile station for communicating to the base station. The EACH operates in the Basic Access Mode and Reservation Access Mode. It is used for transmission of short messages, such as MAC messages, response to pages, and call originations. It can also be used to transmit moderately sized data packets.

EAMPS - Extended Advanced Mobile Phone System

Extension of the radio spectrum which was used by AMPS (Advanced Mobile Phone Service). The additional 10MHz increased the number of channels from 333 per service provider to 416.

EAP - Extensible Authentication Protocol

EAP is an extensible authentication framework and is not a specific authentication mechanism. Instead, EAP provides the means by which other authentication mechanisms can be transported by the EAP protocol. These authentication mechanisms are termed EAP methods, of which several exist including EAP-AKA, EAP-SIM and EAP-TLS, amongst many others.

EAP-TLS - Extensible Authentication Protocol – Transport Layer Security

EAP-TLS is a specific version of the EAP(Extensible Authentication Protocol) providing a framework to support authentication across a number of communication systems. The EAP-TLS variant utilizes digital certificates to generate the various keys.

EAP-TTLS - Extensible Authentication Protocol – Tunnelled Transport Layer Security

EAP-TTLS is a specific version of the EAP(Extensible Authentication Protocol) providing a framework to support authentication across a number of communication systems. Unlike EAP-TLS(Extensible Authentication Protocol – Transport Layer Security) protocol which requires digital certificates at both endpoints, the EAP-TTLS variant only requires a digital certificate at the network side.

EAP/AKA Authentication

An extension to the EAP (Extensible Authentication Protocol) proposed by the IETF (Internet Engineering Task Force) enabling authentication and session key distribution using the UMTS AKA (Authentication and Key Agreement) mechanism. UMTS AKA is based upon symmetric keys and runs typically on a USIM (UMTS Subscriber Identity Module). EAP/AKA Authentication includes optional user anonymity and re-authentication procedures.

EAP/SIM Authentication

An extension to the EAP (Extensible Authentication Protocol) proposed by the IETF (Internet Engineering Task Force) enabling authentication and session key distribution using the GSM SIM (Subscriber Identity Module). The mechanism specifies enhancements to GSM authentication and key agreement whereby multiple authentication triplets can be combined to create authentication response and encryption keys of greater strength than the individual GSM triplets. The mechanism also introduces network authentication, user anonymity and a re-authentication procedure.

EARFCN - E-UTRA Absolute Radio Frequency Channel Number

Since the E-UTRA operates with more flexibility than UMTS , a updated method of identifying the centre carrier frequencies is used. The carrier frequency in the uplink and downlink is designated by the EARFCN (E-UTRA Absolute Radio Frequency Channel Number) in the range 0 – 65535. The channel raster is 100KHz for all bands, which means that the carrier centre frequency must be an integer multiple of 100KHz. The relation between EARFCN and the carrier frequency in MHz for the downlink/uplink is given by an equation and associated table of frequency bands.

EASCII - Extended ASCII

ASCII (American Standard Code for Information Interchange) is a seven bit code. Extended ASCII employs the 8th bit to enhance the addressing space available to define characters in binary.

EATF - Emergency Access Transfer Function

This IMS network element is used during the establishment of emergency calls within a VoLTE deployment. In particular, the E-PCSCF can utilize the EATF as part of the media anchoring process. This ensures that handovers between VoLTE and the 2G/3G CS domain will occur more smoothly.

Eb

A measure of the energy in a signal, at some point in a communication system. This may be per information bit conveyed by that signal, or an average value of such energies. Its relevance to system performance is most often expressed by its ratio to additive noise and interference, such as in E b /N 0.

EBCDIC - Extended Binary Coded Decimal Interchange Code

A code developed by IBM (International Business Machines) in order to define figures and numbers in binary format. The 8bit format offers a possible 256 different characters to be described.

EBCF - Event Based Charging Function

The EBCF forms part of the 3GPP Online billing architecture, responsible for generating billing related information associated with billable events such as sending a text message.

EBS - Excess Burst Size

EBS is a component of the bandwidth profile traffic parameters applicable to a service running over Ethernet networks. It is the number of allocated bytes available for bursts of service frames temporarily sent at rates above the CIR+EIR, while remaining EIR-conformant.

EC - Emergency Call

A call placed by a user to request emergency assistance, typically to an emergency services or public safety provider. Typical numbers include 112, 911 and 999.

EC-AGCH - Extended Coverage – Access Grant Channel

This is a modified GSM / GPRS logical channel used to allocate resources to a mobile or device in support of EC-GSM-IoT operation.

EC-BCCH - Extended Coverage – Broadcast Control Channel

This is a modified GSM / GPRS logical channel used to broadcast ECSI (Extended Coverage System Information) messages in support of EC-GSM-IoT operation.

EC-GSM-IoT - Enhanced Coverage – GSM – Internet of Things

This is a term used to describe a number of enhancements to the second generation cellular technologies of GSM and GPRS in order to more efficiently support M2M (Machine-to-Machine) communications. In simple terms, the technology which was included in the 3GPP Release 13 specifications extends coverage by using a technique based on blind physical layer transmissions.

EC-PACCH - Extended Coverage – Packet Associated Control Channel

This is a modified GSM / GPRS logical channel used to carry signalling information alongside a EC-PDTCH (Extended Coverage – Packet Data Traffic Channel) in support of EC-GSM-IoT operation.

EC-PCH - Extended Coverage – Paging Channel

This is a modified GSM / GPRS logical channel used to carry paging information in support of EC-GSM-IoT operation.

EC-PDTCH - Extended Coverage – Packet Data Traffic Channel

This is a modified GSM / GPRS logical channel used to carry user data (IP packets) in support of EC-GSM-IoT operation.

EC-RACH - Extended Coverage – Random Access Channel

This is a modified GSM / GPRS logical channel used by a mobile / device in order to request resources from, or respond to a page message, in an EC-GSM-IoT network.

EC-SCH - Extended Coverage – Synchronization Channel

This is a modified GSM / GPRS logical channel used to carry a modified BSIC (Base Station Identity Code) and timing information in support of EC-GSM-IoT operation.

Ec/Io

Ec/Io A notation used to represent a dimensionless ratio of the average power of a channel, typically the pilot channel, to the total signal power.

ECB - Electronic Code Book

ECB is the simplest mode of operation for a block cipher. Plain text data is segmented into blocks and each block has the relevant encryption algorithm applied. ECB is considered to be a weak method of encryption and is not recommended to be used in situations where robust encryption is required.

eCCE - Enhanced Control Channel Elements

Introduced in Release 13 of the 3GPP specifications, eCCE are used in eMTC (enhanced Machine Type Communications) and are combined to carry DCI (Downlink Control Information).

ECF - Event Charging Function

For online charging, the AS (Application Server) in the IMS (IP Multimedia Subsystem) network reports accounting information to the ECF. The ECF uses this information to support the content charging function. This is used for real time billing and services such as pre-pay.

ECGI - E-UTRAN Cell Global Identifier

The E-UTRAN Cell Global Identifier is used to identify cells globally. The ECGI is constructed from the MCC (Mobile Country Code), MNC (Mobile Network Code) and the ECI (E-UTRAN Cell Identifier).

Echo

A type of distortion that occurs when a signal is reflected or otherwise returned with sufficient magnitude and delay to be perceived by the speaker.

Echo Canceller

A device or system that reduces or eliminates echoes in voice transmission systems.

ECM - EPS Connection Management

In addition to the LTE Active, Idle and Detached states there also exists various EMM ( EPS Mobility Management) and ECM (EPS Connection Management) states. The EPS Connection Management states describe the signalling connectivity between the UE and the EPC. Two ECM states exist, namely ECM-IDLE and ECM-CONNECTED.

ECMP - Equal Cost Multiple Path

ECMP is a strategy used in packet routing whereby several routes exist to the same destination, all of which have an equal cost and hence will be equal to one another as part of a routing metric calculation. Therefore, if a network hop has ECMP active, it will load balance across all available onward hops.

eCPRI - enhanced Common Public Radio Interface

eCPRI is a separate, alternative standard to the 3GPP’s work on Centralized RAN. Where the 3GPP specifically define the protocol stack split between the Centralised Unit and the Distributed Unit at the PDCP (Packet Data Convergence Protocol) layer, eCPRI offers many more splitting options. The rationale behind this is to provide the service provider with more deployment flexibility.

ECSI - Extended Coverage System Information

Found on the EC-BCCH (Extended Coverage – Broadcast Control Channel), ECSI is specific system information message which contains the rules by which mobiles / devices should operate on a EC-GSM-IoT network. Such information includes cell allocations, cell selection and reselection parameters and network sharing rules.

ECT - Explicit Communication Transfer

ECT is a supplementary service which allows an individual involved in a call to transfer that call to a third party.

EDCA - Enhanced Distributed Channel Access

The term EDCA is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancement. It supports differentiated and distributed access to the Wireless Medium using eight different user priority sub fields supporting four different Access Categories. These are Voice, Video, Best Effort and Background.

EDCAF - Enhanced Distributed Channel Access Function

This is a term used in IEEE (Institute of Electrical and Electronics Engineers) 802.11 networks which are supporting the QoS (Quality of Service) enhancements originally defined in the 802.11e standard. When supporting the EDCA (Enhanced Distributed Channel Access) mode of operation, the EDCAF is responsible for the control of the data streams for each of the four defined access categories.

EDGE - Enhanced Data rates for Global Evolution

EDGE uses the same spectrum allocated for GSM900 , GSM1800 and GSM1900 operation. Instead of employing GMSK (Gaussian Minimum Shift Keying) EDGE uses 8PSK (8 Phase Shift Keying) producing a 3bit word for every change in carrier phase. This effectively triples the data rate offered by GSM. The use of EDGE enables GSM to increase the data rates that can be offered to users of the GSM spectrum. In release 7, Evolved EDGE (also termed EGPRS2) was introduced which offered higher data rates through mechanisms such as latency reduction, use of dual carriers in the downlink, higher order modulation techniques, increased symbol rate and receiver diversity in the mobile.

EDP - Event Detection Point

There are two ways in which a DP may be armed. These are: Statically – a statically armed DP is known as a TDP (Trigger Detection Point) this is always armed within the BCSM. Dynamically – a dynamically armed DP is known as an EDP (Event Detection Point). This will be armed by the SCF (Service Control Function) within the context of an IN service.

EDP-N - Event Detection Point – Notification

A dynamically armed DP is known as an EDP (Event Detection Point). This will be armed by the SCF (Service Control Function) within the context of an IN service. This may be either an EDP-N (Event Detection Point – Notification) – this is dynamically armed and when triggered the event is reported however processing is not suspended or EDP-R (Event Detection Point – Request) – this is dynamically armed and when triggered will suspend call processing. The SSF then waits for instructions from the SCF.

EDP-R - Event Detection Point – Request

A dynamically armed DP is known as an EDP (Event Detection Point). This will be armed by the SCF (Service Control Function) within the context of an IN service. This may be either an EDP-N (Event Detection Point – Notification) – this is dynamically armed and when triggered the event is reported however processing is not suspended or EDP-R (Event Detection Point – Request) – this is dynamically armed and when triggered will suspend call processing. The SSF then waits for instructions from the SCF.

eDRX - extended Discontinuous Reception

Introduced in Release 13 of the 3GPP specifications, eDRX enables mobiles and devices to reduce power consumption by extending the period of time they remain “asleep”. This is particularly important within CIoT (Cellular Internet of Things) networks in order to extend battery life to up to 10 years.

EEA - EPS Encryption Algorithm

E-UTRA includes the support of EEA (EPS Encryption Algorithm) and EIA (EPS Integrity Algorithm). The EEA (EPS Encryption Algorithm) are each assigned a 4bit identifier. Currently, the algorithms which have been defined for NAS , RRC and UP ciphering include Null, SNOW, AES and ZUC.

EEPROM - Electrically Erasable Programmable Read-Only Memory

Erasable Programmable Read Only Memory that can be erased using electrical signals applied to specific pins.

EF - Expedited Forwarding

Expedited Forwarding is a DiffServ Per Hop Behaviour which has characteristics specifically designed for handling real time services such as VoIP.

EGP - Exterior Gateway Protocol

Internet protocol used to pass network reachability and policy information between Autonomous Systems. An example is BGP4 (Border Gateway Protocol 4).

EGPRS - Enhanced General Packet Radio Service

Enhanced GPRS (General Packet Radio Service) uses the modulation technique 8PSK (8 Phase Shift Keying) to increase the achievable user data rate. See EDGE (Enhanced Data rates for Global Evolution).

EGPRS2 - Enhanced General Packet Radio Service phase 2

EGPRS2 or Evolved EDGE is an evolution of the current EDGE technology specified by the 3GPP in their Release 7 specifications. It enables higher data rates, up to 118Kbps, to be supported on both the uplink and downlink air interfaces. This is achieved through a number of enhancements including: latency reduction, support of a dual carrier in the downlink, higher order modulation including 16 QAM and 32QAM, an increase in symbol rate to 325Ksps and receiver diversity in the mobile.

EGPRS2A - Enhanced General Packet Radio Service phase 2 A

This is a variant of the generic EGPRS2 or Evolved EDGE technology. It enables higher data rates, up to 118Kbps, to be supported on both the uplink and downlink air interfaces. This is achieved through a number of enhancements including: latency reduction, support of a dual carrier in the downlink, higher order modulation including 16 QAM and 32QAM, and receiver diversity in the mobile. It does not support the increased symbol rate of 325Ksps unlike EGPRS2-B.

EGPRS2B - Enhanced General Packet Radio Service phase 2 B

This is a variant of the generic EGPRS2 or Evolved EDGE technology. It enables higher data rates, up to 118Kbps, to be supported on both the uplink and downlink air interfaces. This is achieved through a number of enhancements including: latency reduction, support of a dual carrier in the downlink, higher order modulation including 16 QAM and 32QAM, and receiver diversity in the mobile. It also supports the increased symbol rate of 325Ksps unlike EGPRS2-A.

EGSM - Extended GSM

GSM EGSM is an extension to the GSM900 spectrum. The additional 10Mhz provides an additional 50 channels.

EHF - Extremely High Frequency

The portion of the electromagnetic frequency between 30GHz and 300GHz.

EIA - Electronics Industries Alliance

Group that specifies electrical transmission standards.

EIA - EPS Integrity Algorithm

The integrity process in LTE uses an EIA (EPS Integrity Algorithm) which have a 4bit identifier. Examples of EIA algorithms include SNOW and AES. These are implemented in the UE and eNB for RRC signalling integrity protection. In addition, they are also implemented in the UE and MME for NAS integrity protection.

EIFS - Extended Interframe Space

EIFS are found in IEEE 802.11 networks. EIFS unlike SIFS (Short Interframe Space), PIFS (PCF Interframe Space) and DIFS (DCF Interframe Space) has a variable value and is only used when there has been an error in frame transmission. It is not used to control access onto the radio link.

EIGRP - Enhanced Interior Gateway Routing Protocol

An advanced version of Interior Gateway Routing Protocol. It provides superior convergence properties and operating efficiency, and combines the advantages of link state protocols with those of distance vector protocols.

EIR - Equipment Identity Register

The EIR stores IMEI (International Mobile station Equipment Identity) numbers in order to filter unwanted handsets off the network. Handsets are “white listed”, “grey listed” or “black listed” as appropriate and may have their service revoked if they are allocated to the grey or black list. The GERAN, UTRAN and E-UTRAN systems can all use the EIR.

EIR - Excess Information Rate

EIR is a component of the bandwidth profile traffic parameters applicable to a service running over Ethernet networks. It is the maximum sustained information rate by which a user can exceed its CIR, with the expectation that the excess traffic may not be carried across the network due to traffic policing.

EIRP - Equivalent Isotropically Radiated Power

The unit of measurement of the strength of a radiated field. Typically that from a radio antenna.

ELF - Extremely Low Frequency

Extremely Low Frequencies are those frequencies in the spectrum between 30Hz and 300Hz.

eLTE eNB - Evolved LTE eNB

The eLTE eNB is the evolution of eNB that supports connectivity to EPC (Evolved Packet Core) and NGC (Next Generation Core).

EM - Element Management

Element Management describes the notion of monitoring specific network elements as part of a service provider’s OSS (Operations Support Systems) architecture. The management aspect is typically related to FCAPS (Fault, Configuration, Accounting, Performance, Security) activity. In a typical network, several EM systems may exist, in relation to both physical and virtualized network nodes.

eMBB - Enhanced Mobile Broadband

Enhanced Mobile Broadband is a key part of 3GPP 5G SMARTER (Services and Markets Technology Enablers). The study started in 2015 and looked at potential 5G requirements, which resulted in more than 70 different use cases, grouped into CriC (Critical Communications), MIoT (Massive Internet of Things), eMBB (Enhanced Mobile Broadband) and Network Operation.

eMBMS - Evolved Multimedia Broadcast Multicast Services

eMBMS introduces broadcast and multicast service delivery to LTE networks in order to improve the efficiency of delivering identical content to multiple users simultaneously. Key elements of the eMBMS architecture include the BMSC (Broadcast Multicast Service Center), the MBMS Gateway, the MCE (Multi Cell/Multicast Coordination Entity) and the eMBMS enhanced MME.

eMBMS Gateway

The MBMS gateway is the source of a broadcast/multicast flow between the core network and the eNBs within the cell sites involved in the MBMS (Multimedia Broadcast Multicast Service) service. The MBMS Gateway uses SSM (Source Specific Multicast) techniques to deliver the data stream to multiple cell sites simultaneously. The MBMS Gateway may be a standalone network element or may be physically co-located with the combined S-GW/P-GW (Serving Gateway/PDN Gateway) or the BMSC (Broadcast Multicast Service Center).

EMM - EPS Mobility Management

In addition to the LTE Active, Idle and Detached states there also exists various EMM ( EPS Mobility Management) and ECM (EPS Connection Management) states. The EPS Mobility Management states result from the mobility management procedures e.g. Attach and Tracking Area Update procedures. Two EMM states exist, EMM-DEREGISTERED and EMMREGISTERED.

eMOS - estimated Mean Opinion Score

An estimated MOS is calculated based on measurements taken in the network, as opposed to being based on a human’s perception of call quality. Various measurements and factors can be used to contribute to the eMOS.

eMTC - enhanced Machine Type Communications

Introduced in Release 13 of the 3GPP specifications, eMTC is associated with LTE-M, a CIoT (Cellular Internet of Things) technology. eMTC enhances the 3GPP Release 12 MTC (Machine Type Communications) feature.

EN-DC - E-UTRA – NR Dual Connectivity

EN-DC is a Dual Connectivity configuration using the EPC, whereby the master node is a 4G eNB and the secondary node is a 5G en-gNB.

EN-DC - E-UTRA New Radio Dual Connectivity

EN-DC is a Dual Connectivity configuration using the EPC, whereby the master node is a 4G eNB and the secondary node is a 5G en-gNB.

eNB - Evolved Node B

The eNB serves as the base station within the E-UTRAN, terminating the air interface on the network side. Consequently, the eNB is responsible for all radio resource management, as well as allocation of user traffic to the downlink/uplink, security and relaying of higher layer NAS (Non Access Stratum) signalling to the MME (Mobility Management Entity). The eNB is also capable of conducting an inter eNB handover procedure via the X2 interface.

Encapsulated PDU

Encapsulated PDU A LAC (Link Access Control) PDU (Protocol Data Unit) together with the associated overheads required for error checking.

Encapsulated PDU Fragment

Encapsulated PDU Fragment A PDU (Protocol Data Unit) is typically to large to transmit across the radio link. Consequently it must be segmented. This function is performed by the SAR (Segmentation And Reassembly) Sublayer. At this point the segment is termed an Encapsulated PDU Fragment. It is passed from the SAR to the MAC (Medium Access Control) function for coding prior to transmission across the radio link.

Encipher

The process in which a cipher algorithm is employed in order to protect information from eavesdroppers.

Encoder Tail Bits

A fixed sequence of bits added to the end of a block of data to reset the convolutional encoder to a predefined state.

Encryption

Encryption is the security mechanism used for the transformation of data from an intelligible form ( plaintext ) into an unintelligible form ( ciphertext ), to provide confidentiality. The inverse process is called decryption.

Encryption Key

An encryption key is a secret password or code string used as part of the encryption process.

Enhanced Access Channel Preamble

Enhanced Access Channel Preamble A non data bearing portion of the Enhanced Access Probe sent by the MS (Mobile Station) to assist the BS (Base Station) in initial channel acquisition.

Enhanced Access Channel Slot

The assigned time interval for an enhanced access probe. An Enhanced Access Channel Slot consists of a number of Enhanced Access Channel frames. The transmission of an Enhanced Access Probe is performed within the boundaries of an Enhanced Access Channel slot.

Enhanced Access Data Enhanced

The data transmitted while in the Basic Access Mode on the Enhanced Access Channel. This data may also be transmitted while in the Reservation Access Mode on a Reverse Common Control Channel.

Enhanced Access Header

A control header containing access information transmitted immediately after the Enhanced Access Channel Preamble. This is performed while the mobile is in the Reservation Access Mode.

Enhanced Access Probe

An Enhanced Access Channel transmission consisting of an Enhanced Access Channel Preamble. Both Enhanced Access Header and Enhanced Access Data may also be sent in the probe.

Enhanced Access Probe Sequence

A sequence of one or more Enhanced Access Probes on the Enhanced Access Channel.

Enterprise Server

A Sun Solaris term to describe a suite of server applications used to support large software solutions used in mission critical systems.

ENUM - e.164 Number to SIP Address Mapping

ENUM is an IETF Standard (RFC 2916) which maps the public telephone number address space into the DNS. The DNS resource records can then be used to map the telephone number(s) into a collection of service addresses including SIP or H.323 VoIP Addresses.

EOM - End of Message

ATM (Asynchronous Transfer Mode) signalling message indicating the last segment that comprises a higher layer message.

EOT - End of Transmission

Signalling message used to indicate that no more data will be sent during the current session.

EPC - Evolved Packet Core

Evolution of the core network started with Release 4. This provided the starting point for the introduction of IP into the CS domain of the core network as well as enhancements to enable real time and non real time services to be successfully integrated onto a common transport medium. In Release 8 of the 3GPP standards the functionality of the core network is made flatter with much of the intelligence required to support service delivery being placed within domains such as the IMS. Consequently the EPC comprises of the MME (Mobility Management Entity) that performs many of the mobility functions traditionally provided by the SGSN such as paging, security and Idle Mode procedures. EPC also includes the S-GW (Serving Gateway), which replaces the User Plane functionality of the SGSN, as well as the PDN-GW (Packet Data Network Gateway), which terminates the user plane within the EPC.

EPDCCH - Enhanced Physical Downlink Control Channel

Introduced as part of LTE-Advanced, EPDCCH informs mobiles about the scheduling and resource allocation in an optimized way, e.g. for a MTC (Machine Type Communications) mobile.

ePDG - evolved Packet Data Gateway

The ePDG provides access to PS domain services to WLAN UEs. For interaction with the LTE EPC (Evolved Packet Core), an ePDG (Evolved PDG) may be utilised. General responsibilities include IP address management, support for MIP (Mobile IP), QoS enforcement, lawful intercept and security.

EPG - Electronic Programme Guide

The EPG is the term given to the digital guide which represents the TV schedule. Typical EPGs are browsable, with respecting to monitoring TV programming due hours or even days in advance. Interactivity is also often a feature, allowing the subscriber to set reminders and group programs into favourite categories.

EPOC

EPOC is an operating system developed by Symbian, Nokia, Ericsson, Motorola and Panasonic.

EPRE - Energy Per Resource Element

As part of LTE power control the system determines the EPRE (Energy Per Resource Element). The term resource element energy denotes the energy prior to CP insertion. The term resource element energy also denotes the average energy taken over all constellation points for the modulation scheme applied.

EPROM - Erasable Programmable Read-Only Memory

Non-volatile memory chips that are programmed after they are manufactured, and, if necessary, can be erased by some means and reprogrammed.

EPS - Evolved Packet System

EPS is a study group whose objective is to develop a framework for an evolution or migration of the 3GPP system to a higher-data-rate, lower-latency, packet-optimized system that supports, multiple RAT s. It should be noted that this study is also termed SAE (System Architecture Evolution) and the terms are inter-changeable.

EPS-AKA - EPS – Authentication and Key Agreement

The security mechanism used in LTE which involves mutual authentication between the mobile and the network, as well as key distribution to the devices in the network responsible for encryption and integrity checking.

Erlang

The Erlang is a measurement of telephone traffic equivalent to 3600 seconds of telephone use.

ERP - Effective Radiated Power

The product of the power supplied to the antenna and its gain relative to a half wave dipole in a given direction.

Erroneous

Packets or frames are usually erroneous due to transmission errors.

ES-IS - End System to Intermediate System

In ISO (International Standards Organization) protocol employed in systems to achieve router detection and address resolution.

ESA - Extended Service Area

An ESA is an IEEE 802.11 conceptual area in which members of an ESS (Extended Service Set) may communicate. An ESA is larger than or equal to a BSA (Basic Service Area) and may involve several BSS (Basic Service Set) in overlapping or disjointed configurations.

ESInet - Emergency Services IP network

ESInet is an initiative launched in North America and Canada associated with the next generation of 911 dialling services. In the ESInet architecture, Public Safety Answering Points are based on IP communication, which means that interaction between the user and the PSAP can be based on communication techniques other than voice, such as messaging and video.

ESM - EPS Session Management

The ESM ( EPS Session Management) and EMM (EPS Mobility Management) entity is a control plane function which supports all aspects of signalling for PDN (Packet Data Network) session management, such as EPS Bearer Activation and Modification. In a similar way to UMTS and GPRS , the LTE system includes various ESM messages that setup and manage the EPS bearer. The EPS bearer is similar to the PDP Context found in GPRS and UMTS.

ESN - Electronic Serial Number

ESN – Electronic Serial Number A 32bit number assigned by the MS (Mobile Station) manufacturer, uniquely identifying the mobile station equipment. This is similar to the IMEI (International Mobile Equipment Identity) used on European networks.

ESP - Encapsulating Security Payload

ESP is a version of IPSec which support encryption, integrity checking and authentication of each individual IP packet.

ESS - Extended Service Set

An Extended Service Set is comprised of a number of IEEE 802.11 BSS (Basic Service Set) and enables limited mobility within the WiFi network. Stations are able to move between BSS within a single ESS yet still remain connected to the fixed network and so continue to receive emails etc. As a Station moves into a new BSS, it will carry out a reassociation procedure with the new AP (Access Point).

ETACS - Extended Total Access Communications System

Extension of the TACS (Total Access Communications System) system through the allocation of additional radio channels.

ETC - Establish Temporary Connection

It is common to physically locate gsmSRF within a stand alone IP (Intelligent Peripheral). This however requires the service control in the gsmSCF to establish a connection between the MSC and the IP. This is achieved using the ETC message between the gsmSCF and gsmSSF which in turn initiates a traffic channel to be set up between the MSC and the IP.

Ethernet

Baseband LAN (Local Area Network) specification invented by Xerox Corporation and developed jointly by Xerox, Intel, and Digital Equipment Corporation. It can be used to connect computers, workstations, terminals, printers, and other devices located in the same building or campus.

Ethernet Address

The Ethernet address or MAC (Medium Access Control) address is assigned to a Network Interface Card. The address comprises of 48bits. The first 24bits are used to identify the manufacturer of the card. The last 24bits identify the physical interface on the card.

ETSI - European Telecommunications Standards Institute

Standards body established to coordinate the development of telecommunications systems within Europe. These systems relate to fixed, wireless and cellular systems. Recently systems such as GSM and DECT have been devolved to the 3GPP (Third Generation Partnership Project), a collaboration of standards bodies including ARIB (Association of Radio Industries and Businesses) from Japan.

eUICC - Embedded Universal Integrated Circuit Card

Unlike a standard UICC or SIM, an eUICC is not intended to be removed or replaced in the cellular device and as such has been developed to satisfy the IoT market. Profiles can however be changed using the GSMA’s Remote SIM Provisioning standard enabling IoT Devices to switch between service providers without physically visiting / switching the SIM.

EUM - eUICC Manufacturer

This is a term used within the GSMA’s Remote SIM Provisioning standard to describe the manufacturer of an eUICC or embedded SIM.

eURLLC - enhanced URLLC

eURLLC is an enhancement to the URLLC (Ultra Reliable Low Latency Communication) characteristics of 5G which were introduced in Release 15 of the 3GPP specifications. eURLLC, which was introduced in Release 16, features latency of under 1ms and reliability beyond 99.999%.

EV-DO - Evolution Data Optimized

EV-DO has been standardized by the 3GPP2 as part of the CDMA2000 family of standards. EV-DO is designed to provide broadband capabilities to mobile subscribers and is considered to be a 3G technology.

eV2X - Enhancement of V2X

The enhancement of V2X facilitated through the provision of 5G technology. Use cases include vehicle platooning, automated driving, extended sensors and remote driving.

Evolved EDGE

Evolved EDGE or EGPRS2 is an evolution of the current EDGE technology specified by the 3GPP in their Release 7 specifications. It enables higher data rates, up to 118Kbps, to be supported on both the uplink and downlink air interfaces. This is achieved through a number of enhancements including: latency reduction, support of a dual carrier in the downlink, higher order modulation including 16 QAM and 32QAM, an increase in symbol rate to 325Ksps and receiver diversity in the mobile.

EVS - Enhanced Voice Services

EVS is a codec introduced by the 3GPP in Release 12 of the 3GPP specifications. The codec features several modes of operation, including Narrowband, Wideband, Super Wideband and Fullband, with data rates ranging from 5.9kbps through to 128kbps.

Extranet

Intranets are private corporate networks employing internet technology to provide communication and information services to employees. Extranets extend some of these services to customers of the corporation.

F Link - Fully Associated Link

A Fully Associated Link connects two signalling end points. F links are not usually used in networks with STP (Signalling Transfer Points). In networks without STPs F links directly connect signalling points.

F-BCCH - Fast Broadcast Control Channel

A logical channel within the broadcast channels of digital cellular networks as defined by IS-136 (Interim Standard 136).

f-csch - Forward common signaling logical channel

This channel is analogous to Paging and Synchronization Channels.

f-dsch - Forward dedicated signaling logical channel

This channel is analogous to Forward Traffic or Fundamental Channel.

FA - Foreign Agent

A Foreign Agent is a node in a MIP (Mobile IP) network that enables roamed IP users to register on the foreign network. The FA will communicate with the HA (Home Agent) to enable IP datagrams to be transferred between the home IP network and the roamed IP user on the foreign network.

FAB - Fulfilment Assurance and Billing

Within the framework of eTOM (Enhanced Telecoms Operations Map) Level 1, FAB accounts for 3 of the main elements associated with the Operations processes relative to the overall business process framework. Fulfilment involves ensuring that customers are provided with their requested products in a timely and correct manner. Assurance involves ensuring that those products meet expectation and are performing appropriately. Billing involves ensuring that the customer is billed appropriately for use of the product.

FAC - Final Assembly Code

The Final Assembly Code forms part of the IMEI (International Mobile Equipment Identity) and identifies the place of manufacture or final assembly. It is two digits in length.

FACCH - Fast Associated Control Channel

The Fast Associated Control Channel appears in place of the traffic channel when lengthy signalling is required between a GSM mobile and the network while the mobile is in call. The channel is indicated by use of the stealing flags in the normal burst. Typical signalling where this may be employed is during cell handover.

FACH - Forward Access Channel

A UMTS transport channel that forms the downlink half of a transport channel pair known as the RACH (Random Access Channel) / FACH (Forward Access Channel) combination. It is used for downlink signalling and small quantities of data.

Fade Timer

The process involves the MS (Mobile Station) measuring the continuity of a Forward Traffic Channel. If the continuity of the channel is disrupted for a period longer then the Fade Timer then the call is dropped.

FANR - Fast Ack Nack Reporting

This term is used in Evolved EDGE or EGPRS2 to describe the method of reducing latency by piggy backing Ack and Nack messages with the data blocks.

FAR - Forwarding Action Rule

The FAR is a rule which can be presented to a user plane element by a control plane element within either a CUPS (Control and User Plane Separation of EPC Nodes) or 5G Core network scenario. In particular, the FAR will provide information on how a particular packet should be handled (forward, duplicate, drop or buffer).

Fast Ethernet

Fast Ethernet covers any of a number of 100Mbps Ethernet specifications. Fast Ethernet offers a speed increase of 10 times over that of the 10BaseT Ethernet specification, while preserving frame format, MAC (Medium Access Control) mechanisms, and MTU (Maximum Transmission Unit). Such similarities allow the use of existing 10BaseT applications and network management tools on Fast Ethernet networks. The protocol is based on an extension to the IEEE (Institute of Electrical and Electronics Engineers) 802.3 specification.

Fat Client

A Fat Client is a client on which the software applications reside. This is apposed to a thin client in which the client uses the application services on the server side of the network.

FBC - Flow Based Charging

The ability to generate billing records based on a specific flow of data, such as a streaming movie or voip call.

Fc - Carrier Frequency

A term used to identify the centre radio carrier frequency. Most radio systems use multiple carrier frequencies and indicate to the mobile which one to utilize.

FC - Floor Control

Floor control is the deterministic mechanism used in MCPTT to arbitrate between requests that are in contention. On the occasion where multiple requests to transmit occur then determining which user’s request is accepted and which ones are rejected or queued are based upon numerous characteristics, including user priority.

FCAPS - Fault Configuration Accounting Performance and Security

FCAPS relates to the ISO Telecommunications Management Network model, which is designed to provide a standardized approach to network management systems. Where the FCAPS model was largely designed to be network centric, the newer eTOM Business Process Framework is more business centric.

FCC - Federal Communications Commission

Federal Communications Commission is a U.S. government agency that supervises, licenses, and controls electronic and electromagnetic transmission standards.

FCCCH - Forward Common Control Channel

A control channel used for the transmission of control information from a BS (Base Station) to one or more MS (Mobile Station).

FCCCH Chip Bit - Forward Common Control Channel Chip Bit

Number of PN (Pseudorandom Noise) chips per Forward Common Control Channel bit. The PN chips for the various spreading rates are detailed: Spreading Rate FCCH Chip Bits Rate 1 32 x 1 when data rate = 38400bps 32 x 2 when data rate = 19200bps 32 x 4 when data rate = 9600bps Rate 3 96 x 1 when data rate = 38400bps 96 x 2 when data rate = 19200bps 96 x 4 when data rate = 9600bps

FCCH - Frequency Correction Channel

This channel forms part of the GSM broadcast channel. A frequency correction burst is transmitted on the channel which generates a beacon 67.7KHz from the cell carrier frequency.

FCH - Fundamental Channel

A portion of a Traffic Channel that can carry a combination of primary data, secondary data, signaling and power control information.

FCH Chip Bit - Fundamental Channel Chip Bit

The number of PN (Pseudorandom Noise) chips per Fundamental Channel bit, equal to 1228800/ r b for Spreading Rate 1 and 3686400/ r b for Spreading Rate 3 , where r b is the data rate of the Fundamental Channel.

FCH Ec - Fundamental Channel PN bit Energy

Average energy per PN chip for one Forward Fundamental Channel. Fundamental Channel to the total transmit power spectral density.

FCI - Furnish Charging Information

This procedure may be associated with CAMEL interaction for both GSM and GPRS billing functions. When used it instructs the MSC or SGSN to append 40 Octets (Phase 2) or 160 Octets (Phase 3) of free format data collated during the Call or GPRS session to the CDR.

FCS - Frame Check Sequence

A Frame Check Sequence is generated by applying the destination and source addresses along with the packet payload to a polynomial function. The remainder of the function is recorded as the FCS and is added, typically to the trailer of the packet. At the receiving side the same function is conducted and the resulting remainder compared with the FCS. If they are the same the packet is valid.

FD - Frame Delay

FD is a key function for monitoring performance in Ethernet networks. It is the round trip delay for a frame, defined as being the time elapsed between the start of transmission of the first bit of the frame from the source node until reception of the last bit of the loopbacked frame at the source, with loopback being performed at the frame’s destination node.

FD-MIMO - Full-Dimension MIMO

Full-Dimension MIMO is the 3GPP official name for Massive MIMO. It identifies systems with a large number of radio antenna ports.

FDCCH - Forward Dedicated Control Channel

A Dedicated Control Channel that is transmitted on the Forward CDMA (Code Division Multiple Access) Channel.

FDM - Frequency Division Multiplexing

Frequency Division Multiplexing is a technique in which the available transmission bandwidth of a circuit is divided by frequency into narrower bands, each used for a separate voice or data transmission channel. FDM enables multiple user channels to be carried on one physical circuit.

FDMA - Frequency Division Multiple Access

Frequency Division Multiple Access is a technique in which multiple users of a radio system are separated in the frequency domain.

FDV - Frame Delay Variation

FDV is a key function for monitoring performance in Ethernet networks. It is a measure of the variations in the Frame Delay between a pair of service frames, where the service frames belong to the same class.

FE - Functional Entity

A Functional Entity is a generic term for the functions available in IN. Examples of FE include the SSF (Service Switching Function) and SCF (Service Control Function).

FEA - Functional Entity Action

FEA may be chained together to form a FE (Functional Entity). Their chaining and sequencing within the FE make up the SIB (Service Independent Building Block).

Feature Group C

Feature Group C is a tradition toll rate service offered by Local Exchanges Carriers to ATT prior to the breakup of the Bell System.

FEC - Forward Error Correction

Forward Error Correction techniques pass additional information along with the user data to the receiver. Any corruption in the user data can be repaired by use of the additional data. An example of this is convolutional coding. At the receiving side a Viterbi trellis is used to check and correct the data as it is received.

FEC - Forwarding Equivalence Class

FEC is a term used in MPLS networks to describe a set of incoming packets with similar characteristics, allowing those packets to be allocated the same label and forwarded down the same LSP (Label Switched Path). Particular examples could include identical destination addresses or DSCP (Differentiated Services Code Point) values.

FECN - Forward Explicate Congestion Notification

A Frame Relay signalling message sent upstream to inform frame handlers that downstream frame handlers are suffering congestion. This message will trigger upstream frame handlers to reduce the down stream flow of frames.

Femto Cell

A Femto Cell, as defined by the 3GPP in their Release 8 specifications, can be simply described as a personal base station which is sited inside a subscriber’s home or small business. As it is able to provide targeted coverage, the Femto Cell can significantly increase the bandwidth available to a mobile within its field of operation. The Femto Cell or HNB connects to the service provider’s network via a broadband IP network and HNB-GW. Unlike similar technologies such as UMA , which uses an alternative radio access technology like WiFi , Femto Cells support standard cellular air interfaces such as UMTS and CDMA2000.

FFCH - Forward Fundamental Channel

A Fundamental Channel that is transmitted on the Forward CDMA (Code Division Multiple Access) Channel.

FFT - Fast Fourier Transform

OFDM systems utilize a mathematical function called FFT (Fast Fourier Transform)to generate parallel data streams. This process relies on a concept termed Discrete Fourier Transform which provides a way of analyzing the components of a complex waveform. Therefore, the data stream is first converted from a serial stream into a number of parallel virtual branches, the number being equal to the number of virtual sub-carriers in operation in the channel. The appropriate modulation scheme to be employed on each sub-carrier is selected and the Inverse FFT system will calculate the characteristics of the combined waveform which in turn is transmitted across the air interface. At the receiver side, this signal is passed to the FFT entity which generates the composite virtual data streams which can be combined to form a copy of the original data stream.

FGA - Feature Group A

Feature Group A offers access to the LE (Local Exchange) carrier network through a subscriber line rather than a trunk line.

FGB - Feature Group B

Similar to FGA (Feature Group A) but offers a superior connection to the LE (Local Exchange) carrier network.

FH-PHY - Frequency Hopping Physical Layer

The Frequency Hopping Physical Layer was developed for IEEE 802.11 to enable multiple networks to coexist in the same frequency band yet minimize the effect of interference. The system operates by switching the frequency upon which data is transmitted in a pseudorandom manner. Hence the term Frequency Hopping. Should one frequency suffer from interference, it will only effect a very small percentage of the total information since that frequency will only be utilised occasionally in the hopping sequence. To support frequency hopping, the 2.4GHz ISM (Industrial Scientific and Medical) band is divided into 95 channels, each separated by 1MHz. Unfortunately these channels may not all be available, as different regulatory bodies have allocated different portions of the ISM band.

FHSS - Frequency Hopping Spread Spectrum

In FHSS the total frequency band is split into a number of channels. The broadcast data is spread across the entire frequency band by hopping between the channels in a pseudo random fashion.

FI - Frame Information

This field is part of E-UTRA RLC (Radio Link Control) and indicates different segmentation options for a RLC SDU (Service Data Unit).

FIFO - First-in First-out

First In First Out is a term used to describe routing buffers where no QoS (Quality of Service) is applied to packets entering the router. Packets are treated in the order that they are received by the router. QoS routers use processes such as weighted fair queuing and weighted round robin in order to provide QoS to IP packet services.

FIPS - Federal Information Processing Standard

NIST (National Institute of Standards and Technology) produces guidelines and standards for the development of federal computer systems. These standards and guidelines are issued by NIST as FIPS (Federal Information Processing Standards) for use by government departments.

Firewall

A combination of hardware and software employed to protect services sitting behind the firewall. Firewalls filter and reject incoming and outgoing data based on specific criteria programmed into the firewall. This filtering may be anywhere between Layer 7 and 1 of the OSI (Open System Interconnection) model.

Firewire

Firewire is a 100Mbps serial connection. It is a six pin cable with a maximum length of 4.5 meters and is employed to connect video equipment to data storage drives such as the Personal Computer hard disk. The standard is defined in IEEE (Institute of Electrical and Electronics Engineers)1394.

FISU - Fill In Signalling Unit

The Fill In Signalling Unit acts as flag in TDM (Time Division Multiplexing) based SS7 (Signalling System No.7) signalling networks when there is no other information to send. The FISU consists of MTP3 (Message Transfer Part – Level 3) routing information and is sent in place of flags in idle periods. It also serves to verify the integrity of the link as the receiving side will performing a FCS (Frame Check Sequence) on the FISU.

FIX - Federal Internet Exchange

Federal Internet Exchange is a physical connection point for federal networks such as the MILNET (Military Network), National Aeronautics and Space Administration, Science Net and the Federal Government Networks.

Fixed Wireless Local Loop

Based in the 10MHz spectrum these wireless connections are designed to offer data and speech services to the home user. This technology is also known as Fixed Radio Access.

Flash

Flash An indication sent on the Reverse CDMA (Code Division Multiple Access) Channel by the MS (Mobile Station) to invoke special processing.

Flash memory

This is a special kind of EEPROM (Electrically Erasable Programmable Read-Only Memory) that can be erased and reprogrammed in blocks rather that in one byte chunks. It provides non-volatile storage so that software images can be stored, booted, and rewritten as necessary.

Flash RAM

Very Fast RAM (Random Access Memory).

Flash ROM

ROM (Read Only Memory) that may be reprogrammed.

FLR - Frame Loss Ratio

FLR is a key function for monitoring performance in Ethernet networks. It is defined as a percentage of the number of service frames not delivered in relation to the total number of service frames sent, during a specific time period.

FM - Frequency Modulation

Frequency Modulation is a technique in which the frequency of the carrier is shifted by an amount proportional to the amplitude of the modulated signal.

FMC - Fixed Mobile Convergence

Fixed-mobile convergenceis the trend towards seamless connectivity between fixed and wireless telecommunications networks. The term also describes any physical network that allows mobile cellular devices to function smoothly with the fixed network infrastructure. The ultimate goal of FMC is to optimize transmission of all data, voice and video communications to and among end users, no matter what their locations or devices.

FMS - First Missing PDCP Sequence Number

This field is part of E-UTRA PDCP (Packet Data Convergence Protocol) and indicates the PDCP SN (Sequence Number) of the first missing PDCP SDU (Service Data Unit).

FMSS - Flexible Mobile Service Steering

Flexible Mobile Service Steering is a 3GPP feature that enables efficient steering on the Gi or SGi interfaces. A Service Provider can utilize information related to the user profile, technology, applications etc. to define specific traffic steering policies. As such, traffic can be steered to appropriate enablers , for example a NAT (Network Address Translation) or firewall.

FN - Frame Number

The number given to consecutive frames generated by a transmitter.

FOCC - Forward Control Channel

The Forward Control Channel is a downlink analogue AMPS (Advanced Mobile Phone Service) channel. It is used to support paging, broadcast and access messages to the mobile.

Foreign NID Roamer

If a MS (Mobile Station) is operating in the same SID (System Identification) but in a different NID (Network Identification) from the one in which the service was subscribed then it is termed a foreign NID Roamer.

Foreign SID Roamer

If a MS (Mobile Station) is operating in a SID (System Identification) other than the one from which service was subscribed then it is termed a Foreign SID Roamer.

Forward CDMA Channel

A CDMA (Code Division Multiple Access) Channel from a BS (Base Station) to MS (Mobile Station). This channel typically contains one or more code channels that are transmitted on a CDMA Frequency Assignment.

FP - Frame Protocol

Frame Protocol is the user plane protocol for the Iur and Iub interfaces, facilitating the transferral of Transport Channels.

FPCH - Forward Pilot Channel

A direct sequence spread spectrum signal transmitted continuously by each CDMA (Code Division Multiple Access) BS (Base Station). The Forward Pilot Channel allows a MS (Mobile Station) to acquire the timing of the Forward CDMA Channel. It also provides a phase reference for coherent demodulation, and provides a means for comparing the signal strength of neighbouring base stations during the handoff process. The pilot PN (Pseudorandom Noise) sequence time phase is used to identify an individual BS.

FPLMN - Future Public Land Mobile Network

A term used to describe the future makeup of mobile networks. These may be fourth or fifth generation systems.

FQDN - Fully Qualified Domain Name

A FQDN is a term used to describe the absolute location of a node within the DNS (Domain Name System). FQDNs allow DNS to trace the address of a network node such as a server through the DNS tree hierarchy to a Top Level Domain and eventually to the root nameserver.

FQI - Frame Quality Indicator

A parameter to indicate if a frame has been corrupted. This signaling message may also indicate where in the system the frame became corrupted. This may be over the radio connection or during a specific processing task.

Frame

A frame typically resides at Layer 2 , the data link layer, of the OSI (Open System Interconnection) seven layer model. The frame relates to the header and trailer that surround the higher layer PDU (Protocol Data Unit). Typical frames include HDLC (High Level Data Link Control) in which the frames are delineated by flags which consist of zero followed by six ones and then a zero. No other bit sequence in the flow will have this combination. To avoid this combination at any other time bit stuffing is used.

Frame Category

Frame Category A classification of a received Traffic Channel. The frame classification is based upon transmission data rate, frame content and detected errors. Typical examples include primary traffic, secondary traffic, and signaling traffic.

Frame Offset

Frame Offset A time offset mechanism to skew Traffic Channel frames from System Time in integer multiples of 1.25ms. The maximum frame offset is 18.75ms.

Frame Relay

Frame Relay services are based on Broadband ISDN. The system supports very basic frames consisting of a logical channel address known as a DLCI.(Data Link Connection Identifier). Frame handlers switch the logical channels based on switching tables populated through signalling or network management functions. Frames are variable in length with the maximum payload of 4,096 octets.

Framing Protocol

Framing Protocol A protocol used in UMTS on the Iur and Iub interfaces to frame channels supported between the SRNC (Serving Radio Network Controller) and UE (User Equipment).

FSCCH - Forward Supplemental Code Channel

A Supplemental Code Channel that is transmitted on the Forward CDMA (Code Division Multiple Access) Channel.

FSK - Frequency Shift Keying

In Frequency Shift Keying the carrier frequency is shifted between distinct frequencies. A common shift pattern is between two frequencies one representing a zero and the other a one.

FTCH - Forward Traffic Channel

One or more code channels used to transport user and signaling traffic from the BS (Base Station) to the MS (Mobile Station).

FTFPCH - Forward Transmit Diversity Pilot Channel

A pilot channel transmitted by a CDMA (Code Division Multiple Access) BS (Base Station) from the non primary antenna when orthogonal transmit diversity is employed.

FTP - File Transfer Profile

The File Transfer Profile enables Bluetooth devices to exchange files in a generic way.

FTP - File Transfer Protocol

A client server application protocol using well known ports 20 and 21. It uses the services of TCP (Transmission Control Protocol) to provide reliability in the transfer of data files between network nodes. FTP was first defined as a standard in RFC (Request for Comments) 959.

FTTx - Fibre To The x

FTTx essentially stands for Fibre to the most economical point, with respect to the significant cost of deploying a fibre optic network. The point may be the customer premises, as in the case of FTTH (Fibre To The Home), or may be the street cabinet, as in the case of FTTN (Fibre To The Node). Either way, provision of FTTx connectivity is the ultimate solution for providing extremely high capacity bandwidth to the consumer.

Full Duplex

A bearer capable of simultaneous transmission between both hosts partaking of the session. TCP (Transmission Control Protocol) is an example of a full duplex session.

Full TMSI - Full Temporary Mobile Subscriber Identity

The combination of TMSI Zone and TMSI. The full TMSI is a globally unique address for the MS (Mobile Station).

Fuzzy Logic

Fuzzy logic is a precise sub form of mathematics in which human thinking can be simulated through mathematical models.

FWA - Fixed Wireless Access

FWA is a variety of wireless broadband, where a radio link is employed as a bearer for voice and data, rather than the traditional bearers such as copper and fibre.

G Recommendation Series

The G series of ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) specifications defines transmission facilities. Examples of these facilities include E1 bearers, SDH (Synchronous Digital Hierarchy) and xDSL (Digital Subscriber Line technologies).

G.703

ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) standard G.703 specifies the electrical and physical characteristics of digital interfaces. These start with the E1 and T1 rates employed in Europe and the USA respectively.

G.704

ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) standard G.704 defines the frame structure for the primary and secondary hierarchy levels.

G.707

ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) standard G.707 defines the bit rates that may be supported by SDH (Synchronous Digital Hierarchy).

G.708

ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) standard G.708 defines the SDH (Synchronous Digital Hierarchy) NNI (Network to Network Interface).

G.711

ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) standard G.711 defines the algorithms for the transmission and reception of PCM (Pulse Code Modulation) data.

G.723.1

ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) standard G.723.1 defines codecs for low bit rate speech. The bit rates are 5.3Kbps and 6.3Kbps and are rates employed in VoIP (Voice over IP) systems such as H.323 and SIP (Session Initiation Protocol).

G.726

ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) standard G.726 defines ADPCM (Adaptive Differential Pulse Code Modulation) algorithms which support speech rates of 40Kbps, 32Kbps, 24Kbps and 16Kbps.

G.729

ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) standard G.729 is the codec standard for speech rates of 8kbps, 6.4kbps and 11.4kbps. This is the codec supported in many mobile cellular systems.

G.804

ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) standard G.804 specifies the mapping of ATM (Asynchronous Transfer Mode) cells into PDH (Plesiochronous Digital Hierarchy) systems.

G.990

ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) standard G.990 specifies the requirements for enabling Mbps rates on traditional copper telephone lines. These standards form the basis for DSL (Digital Subscriber Line) based systems.

Ga Interface

The Ga interface is a GPRS interface which is located between the GSN (GPRS Support Nodes) and CGF (Charging Gateway Function).

GACSR - Generic Access Circuit Switched Resource

The term GA-CSR defines a protocol found within the GANC and MS of a network supporting Generic Access – formerly UMA. It is responsible for the bearer establishment, paging, ciphering configuration etc during circuit switched operation.

GAN - Generic Access Network

The term GAN is used to define an access network conforming to the 3GPP Release 6 specifications. Formally, this was referred to as a UMAN and the two unlicensed radio technologies were defined as WiFi and Bluetooth.

GANC - Generic Access Network Controller

Formerly referred to as a UNC , the GANC forms part of the 3GPP Release 6 GAN. It provides the connection between the mobile and the MSC / SGSN over the generic IP access network and in so doing, supports both the A and Gb interfaces towards the core network. The GANC also contains the SEGW.

GAPSR - Generic Access Packet Switched Resource

The term GA-PSR defines a protocol found within the GANC and MS of a network supporting Generic Access – formerly UMA. It is responsible for the delivery of GPRS signalling, SMS transfer, paging, flow control and GPRS transport channel management in addition to the transfer of GPRS user plane data.

GARC - Generic Access Resource Control

The term GA-RC defines a protocol found within the GANC and MS of a network supporting Generic Access (Originally UMA). It is responsible for the discovery and registration process which takes place between the mobile and the GANC.

Gating Rate Set

This specifies the set of supported reverse pilot gating rates. The BS (Base Station) and the MS (Mobile Station) may support one or more gating rates.

Gaussian Noise

Gaussian noise also known as white noise or thermal noise was first defined by Karl Gauss the German mathematician. Gaussian noise is evenly distributed across the entire range of frequencies.

GAVDP - Generic Audio/Video Distribution Profile

The Generic Audio/Video Distribution Profile is used in a Bluetooth device for the distribution of audio/video content using an ACL (Asynchronous Connectionless Link) channel.

Gb Interface

The Gb interface is a GPRS interface which is located between the SGSN (Serving GPRS Support Node) and the PCU (Packet Control Unit).

GBR - Guaranteed Bit Rate

In LTE Dedicated bearers carry traffic for IP flows that have been identified to require a specific packet forwarding treatment. Dedicated bearers can be either GBR (Guaranteed Bit Rate) or non-GBR. A GBR bearer has a guaranteed bit rate and MBR (Maximum Bit Rate) while more than one non-GBR bearer belonging to the same UE shares an AMBR (Aggregate Maximum Bit Rate). Non-GBR bearers can suffer packet loss under congestion while GBR bearers are immune to such losses. Consequently these bearers are generally subject to admission control within the network.

Gc Interface

The Gc interface is a GPRS interface which is located between the GGSN (Gateway GPRS Support Node) and the HLR (Home Location Register).

GCAC - Generic Connection Admission Control

Generic Connection Admission Control is the process at the UNI (User to Network Interface) in an ATM (Asynchronous Transfer Mode) network that assesses if sufficient resources are available within the network to support the requested service.

GCP - Gateway Control Protocol

Also known as H.248 and occasionally MEGACO, GCP is the control protocol used between a Media Gateway Control Function and a Media Gateway.

GCRA - Generic Cell Rate Algorithm

Generic Cell Rate Algorithm is used to assess conformance of data entering the ATM (Asynchronous Transfer Mode) network at the UNI (User to Network Interface). The input of ATM cells is based on a QoS (Quality of Service) contract agreed between the customer and the network provider; the GCRA ensures this contract is adhered to by traffic shaping. If the flow does not conform to the agreed contract, the ATM switch may drop the non conforming cells.

GD - Graceful Discard

Graceful Discard is a Frame Relay term in which frames above the committed frame rate may be dropped to avoid network congestion. It is termed graceful since this process is agreed between the network provider and network user. The Frame Relay network will support information up to the committed information rate; above this rate, cells may be dropped.

GE - Gigabit Ethernet

Gigabit Ethernet is the Ethernet standard offering Gigabit services. The standard typically employs fibre but can be supported on Cat 6 cable. This technology until now has been used for campus style backbone networks; it is now finding its way to the desktop for high end servers and intensive graphical applications.

GEO - Geostationary Earth Orbit

Geostationary Earth Orbit is an orbit 22,237 miles above the Earth surface. Satellites are launched into this orbit and rotate with the Earth such that the satellite footprint remains in the same place across the Earth’s surface.

GERAN - GSM EDGE Radio Access Network

The GSM Edge Radio Access Network supporting the EDGE (Enhanced Data rates for Global Evolution) modulation technique has been specified to connect the A , Gb and Iu interfaces to the CN (Core Network). The architecture allows two BSS (Base Station Subsystem) to be connected to each other.

GF - Gate Function

A GF is used in the provision of SBLP (Service Based Local Policy) in order to allow or prevent flows of data based on classifiers such as destination IP address and port. The GF is typically positioned in the access network and opened/closed by a PDF (Policy Decision Function) in the core.

Gf Interface

The Gf interface is a GPRS system interface which is located between the SGSN (Serving GPRS Support Node) and the EIR (Equipment Identity Register).

GFBR - Guaranteed Flow Bit Rate

The GFBR is used in 5G to define the expected bit rate that a GBR (Guaranteed Bit Rate) QoS Flow can provide.

GFC - Generic Flow Control

Generic Flow Control is employed in the header of the ATM (Asynchronous Transfer Mode) cell at the UNI (User to Network Interface) interface. It is used to define a multiplicity of users at a common interface.

GGSN - Gateway GPRS Support Node

The Gateway GPRS Support Node supports the edge routing function of the GPRS network. To external packet data networks the GGSN performs the task of an IP router. Firewall and filtering functionality, to protect the integrity of the GPRS core network, are also associated with the GGSN along with a billing function.

Gi Interface

The Gi Interface is a GPRS interface which is located between the GGSN (Gateway GPRS Support Node) and the external PDN (Public Data Network).

GIAC - General Inquire Access Code

The General Inquire Access Code is the default inquiry code which is used to discover all Bluetooth devices in range.

GIBA - GPRS IMS Bundled Authentication

An authentication mechanism which is an interim solution for devices which are not fully compliant with IMS AKA. A user’s IP address which has been allocated when they establish a PDP Context is passed to the HSS and linked to their private/public ID. Future requests to the IMS must come from the same IP address in order

GIF - Graphics Interchange Format

Graphics Interchange Format is a format for compressing images, logos and drawings. The format supports 256 colours and file sizes are typically just a few kilobits. They are normally used in web based information due to the low download speeds required by these services.

GIX - Global Internet Exchange

Global Internet Exchange are points within the Internet where networks are physically connected together. The physical connection is typically a Gigabit Ethernet connection.

GLMS - Group List Management Server

An IMS Application Server responsible for managing and storing the group lists associated with social presence. Each subscriber will have a group list which they can manage at the GLMS, typically using XCAP.

GLR - Gateway Location Register

The GLR (Gateway Location Register) is a node between the VLR (visitor Location Register) and/or SGSN (Serving GPRS Support Node) and the HLR (Home Location Register), which may be used to optimise the location updating and the handling of subscriber profile data across network boundaries. When a subscriber is roaming the GLR plays the role of the HLR towards the VLR and SGSN in the visited network and the role of the VLR and SGSN towards the HLR in the home network.

GMDSS - Global Maritime Distress and Safety System

GMDSS was developed as part of the Safety of Life at Sea convention. GMDSS covers the globe using four defined sea areas, and in conjunction with shore based systems provides a far more robust safety system than the legacy Morse Code systems.

GMLC - Gateway Mobile Location Centre

GMLC – Gateway Mobile Location Centre The Gateway Mobile Location Centre contains functionality required to support LCS (LoCation Services). In one PLMN (Public Land Mobile Network), there may be more than one GMLC. The GMLC is the first node an external LCS client accesses in a GSM or UMTS network. The GMLC may request routing information from the HLR (Home Location register) or HSS (Home Subscriber Server). After performing registration authorization, it sends positioning requests to either the VMSC (Visited Mobile Switching Centre), SGSN (Serving GPRS Support Node) or MSC (Mobile Switching Centre) Server and receives final location estimates from the corresponding entity.

GMM - GPRS Mobility Management

GPRS MM is a sublayer of the Layer 3 connectivity between the mobile and the GPRS core network, providing services which support the mobility of user terminals, as well as location reporting when required. Additional features include providing user identity confidentiality, along with authentication and ciphering negotiation.

GMPLS - General Multiprotocol Label Switching

General Multi Protocol Label Switching is applied to MPLS signalling that is used not only to support packet based paths but other technologies such as Optical MUX (Multiplexer), ATM (Asynchronous Transfer Mode) and Frame Relay switches.

GMSC - Gateway Mobile Switching Centre

A Gateway Mobile Switching Centre provides an edge function within a PLMN (Public Land Mobile Network). It terminates the PSTN (Public Switched Telephone Network) signalling and traffic formats and converts this to protocols employed in mobile networks. For mobile terminated calls, it interacts with the HLR (Home Location Register) to obtain routing information.

GMSK - Gaussian Minimum Shift Keying

Gaussian Minimum Shift Keying is the modulation technique used in GSM networks. It employs a form of FSK (Frequency Shift Keying). GMSK was chosen because it provides good spectral efficiency.

Gn Interface

The Gn interface is a GPRS interface which is located between the GSN (GPRS Support Nodes).

gNB - Next Generation Node B

The gNB is a 3GPP 5G Next Generation base station which supports the 5G New Radio.

GOEP - Generic Object Exchange Profile

In the Bluetooth system, the Generic Object Exchange Profile defines the set of procedures and messages to be used by applications handling object exchanges. The GOEP has three main features which are: Establishing an Object Exchange session, Pushing a data object and Pulling a data object. An example of GOEP in action could be a file transfer and synchronisation between such devices as mobile phones, portable PC and PDA (Personal Digital Assistant).

Gold Codes

Gold codes were developed by Robert Gold. These codes possess pseudo random properties ensuring both favourable auto and cross correlation characteristics. Such codes are used in direct sequence spread spectrum systems such as UMTS in order to describe channels across the radio interface.

Good Message

A received message is declared a good message if it is received with a correct CRC (Cyclic Redundancy Code).

GOS - Grade of Service

Grade of Service defines the quality of a telephone service in terms of a user receiving a network busy signal.

GP - Guard Period

In LTE , the radio frame structure type 2 is used for TDD operation and consists of two half-frames with a duration of 5ms each and containing each 8 slots of length 0.5ms and three special fields ( DwPTS , GP and UpPTS ) which have configurable individual lengths and a total length of 1ms. The GP is between the DwPTS and the UpPTS.

Gp Interface

When the GGSN (Gateway GPRS Support Node) and the SGSN (Serving GPRS Support Node) are located in different networks, they may be interconnected via the Gp interface. This interface provides similar functionality to that of the Gn interface, however it usually includes extra security functionality which is based on mutual agreements between operators.

GPRS - General Packet Radio Service

GPRS is defined by 3GPP ( Third Generation Partnership Project) and is employed to connect mobile cellular users to PDN (Public Data Network). Within the GSM network it shares the network databases and radio access network and employs functions known as the PCU (Packet Control Unit), SGSN (Serving GPRS Support Node) and GGSN (Gateway GPRS Support Node) to provide packet switching data services across the fixed and radio network. GPRS offers packet data bearers within 3G networks. The functions of the SGSN and GGSN are the same as those in the GSM network. The difference is the capability of the radio access network. The RNC (Radio Network Controller) supports RAB (Radio Access Bearer) that can support real time bearer services in the region of 100Kbps to 300Kbps. Furthermore, with the introduction of HSPA , this figure can approach 3Mbps. Billing for GPRS services is typically based on volumes, although a number of service providers around the globe have adopted a fixed fee, unlimited download model.

GPRS-CSI - GPRS-CAMEL Subscription Information

The inclusion of GPRS-CSI in the HLR is an indication that the user has subscribed to GPRS CAMEL Services. It includes: gsmSCF Address – this is the identity of the CSE (CAMEL Service Environment) to be used for service interaction i.e. the gsmSCF. It is made up of a global address enabling visited networks to identify the gsmSCF and route signalling accordingly. Service Key – the CSI also contains information related to the OSS of the subscriber and is termed the Service Key. This is used to identify the service logic to be used by the gsmSCF. It is administered by the HPLMN and is passed transparently by the VPLMN / IPLMN to the gsmSCF. Default Call Handling – this indicates whether the call shall be released or continued when there is an error in the dialogue between the gprsSSF and gsmSCF. An example of this maybe when the requests from the gprsSSF are not acknowledged by the gsmSCF despite repeated re-transmissions. Each Service Key has a default call handling setting associated with it. TDP (Trigger Detection Point) List – this indicates at which detection point CAMEL triggering will take place.

gprsSSF - GPRS Service Switching Function

The SSF and SCF functions within GSM are termed the gsmSSF and gsmSCF. These are interconnected by CAP (CAMEL Application Part) interfaces which in turn utilize the services of SS7 (Signalling System No.7) to transport the CAMEL information flows. The functionality of the CAMEL Service Environment defined in Phase 3 enables the gsmSCF to interact with GPRS. This interaction is made possible through the addition of the gprsSSF which resides at the SGSN.

GPS - Global Positioning System

Global Positioning System comprises of multiple satellites all of which orbit the earth twice a day. Users with a GPS receiver use timing information from the satellites in order to triangulate their position on the earth surface. The more accurate military system has now been enabled for civilian use, giving location fixes to within 10 meters.

GPSI - Generic Public Subscription Identifier

The GPSI is used as a means of addressing a 3GPP subscription in data networks outside the realms of a 3GPP system. GPSIs are public identifiers such as a MSISDN or an External Identifier.

Gr Interface

The Gr interface is a GPRS interface which is located between the SGSN (Serving GPRS Support Node) and the HLR (Home Location Register).

GRE - Generic Routing Encapsulation

Generic Routing Encapsulation is an IP based term applied to the encapsulation of IP datagrams tunnelled through an internet. The encapsulation includes security, typically in the form of IPSec , and is most commonly found in VPN (Virtual Private Network) implementations.

Group 1 Fax

The Groups relate the speed and sophistication of the fax machine. The standards were developed by the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) in order that fax machines from different manufactures could communicate. Group 1 fax machines transmit on 8.5 by 11 inch paper at a rate of six pages per minute and conform to the T2 ITU-T standard.

Group 2 Fax

The Groups relate the speed and sophistication of the fax machine. The standards were developed by the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) in order that fax machines from different manufactures could communicate. Group 2 fax machines transmit on 8.5 by 11 inch paper at a rate of three pages per minute and conform to the T3 ITU-T standard.

Group 3 Fax

The Groups relate the speed and sophistication of the fax machine. The standards were developed by the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) in order that fax machines from different manufactures could communicate. Group 3 fax is the most common type of fax machine transmitting on A4 paper. The machine scanning format is digital and operates at rates between 9.6Kbps and 14.4Kbps.

Group 4 Fax

The Groups relate the speed and sophistication of the fax machine. The standards were developed by the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) in order that fax machines from different manufactures could communicate. Group 4 faxes operate on a 64Kbps ISDN (Integrated Services Digital Network) B Channel. Consequently, unlike Group 3 faxes, the digital scan information is not converted into an analogue signal.

GRUU - Globally Routable User agent URI

A GRUU is a IETF (Internet Engineering Task Force) term which describes an addressing scheme that associates an IMS Public Identity to the address of a particular UE (User Equipment). Using a GRUU, S-CSCF (Serving Call Session Control Function) will not have to fork requests to multiple UE registered to the same Public Identity.

GRX - GPRS Roaming eXchange

The Gp Interface connects PLMN (Public Land Mobile Network) together. This interface is IP based and must support appropriate routing and security protocols to enable a subscriber to access its home services from any of its home PLMN’s roaming partners. Many GPRS operators/carriers have abstracted these functions through the GRX (GPRS Roaming eXchange). This function is typically provided by a 3rd party IP network offering VPN (Virtual Private Network) services that connects all the roaming partners together. The GRX service provider ensures all aspects of routing and security between the networks are optimized for efficient operation.

Gs Interface

The Gs Interface is a GPRS interface which is located between the SGSN (Serving GPRS Support Node) and the MSC (Mobile Switching Centre).

GSM - Global System for Mobile communication

The Global System for Mobile communications is a second generation cellular telecommunication system which was first planned in the early 1980s. Unlike first generation systems operating at the time, GSM was digital and thus introduced greater enhancements such as security, capacity, quality and the ability to support integrated services. Initially, GSM was planned to be a European system allowing subscribers to roam between different networks however, GSM was quickly adopted by many other regions and is now a Global System. Many countries around the world have now met market saturation point, which means over 100% of the population of that country possess a GSM phone.

GSM Phase 2+ Service

GSM Phase 2+ Service Phase 2+ offers enhanced bearer services in terms of enhanced full rate data at 14.4Kbps, HSCSD (High Speed Circuit Switched Data) and GPRS. Additional supplementary services are also included.

GSM R - Global System for Mobile communications Railway

GSM-R is a European standard for Railway communications based on the GSM standard. This system is designed to support all radio applications required for railway operations, including speech, data and control communication.

GSM1800

The Global System for Mobile communications (GSM) is a second generation cellular telecommunication system which was first planned in the early 1980s. Unlike first generation systems operating at the time, GSM was digital and thus introduced greater enhancements such as security, capacity, quality and the ability to support integrated services. Initially, GSM was planned to be a European system allowing subscribers to roam between different networks however, GSM was quickly adopted by many other regions and is now a Global System. Many countries around the world have now met market saturation point, which means over 100% of the population of that country possess a GSM phone. The spectrum range for the GSM1800 operation is between 1710MHz and 1785MHz for uplink operation and 1805MHz and 1880MHz for downlink operation. GSM 1800 is also termed PCN (Personal Communication Network) and DCS (Digital Cellular System) 1800.

GSM1900

The Global System for Mobile communications (GSM) is a second generation cellular telecommunication system which was first planned in the early 1980s. Unlike first generation systems operating at the time, GSM was digital and thus introduced greater enhancements such as security, capacity, quality and the ability to support integrated services. Initially, GSM was planned to be a European system allowing subscribers to roam between different networks however, GSM was quickly adopted by many other regions and is now a Global System. Many countries around the world have now met market saturation point, which means over 100% of the population of that country possess a GSM phone. The spectrum range for the GSM1900 operation is between 1850MHz and 1910MHz for uplink operation and 1930MHz and 1990MHz for downlink operation. GSM1900 is also known as PCS (Personal Communication System) 1900.

GSM900

The Global System for Mobile communications (GSM) is a second generation cellular telecommunication system which was first planned in the early 1980s. Unlike first generation systems operating at the time, GSM was digital and thus introduced greater enhancements such as security, capacity, quality and the ability to support integrated services. Initially, GSM was planned to be a European system allowing subscribers to roam between different networks however, GSM was quickly adopted by many other regions and is now a Global System. Many countries around the world have now met market saturation point, which means over 100% of the population of that country possess a GSM phone. The spectrum range for the GSM900 operation is between 890Mhz and 915MHz for uplink operation and 935Mhz and 960MHz for downlink operation.

gsmSCF - GSM Service Control Function

The gsmSCF defines the IN control environment for a mobile network and has been enhanced to enable interworking with GSM/GPRS systems. The gsmSCF also stores the service logic associated with IN services.

gsmSRF - GSM Specialized Resource Function

The gsmSRF enables user interaction with the service and is controlled by the gsmSCF (GSM Service Control Function). This may trigger the gsmSRF to play announcements collect numbers (e.g. a PIN or account number) collect voice commands etc.

gsmSSF - GSM Service Switching Function

The gsmSSF (GSM Service Switching Function) function interworks with the MSC/VLR and the GMSC. Based on information defined in the users subscription and sent from the HLR to the VLR triggers within the MSC and gsmSSF can be set. These triggers are used to dictate when the gsmSSF will communicate with the gsmSCF. This in turn will determine how IN based services are handled.

GSN - GPRS Support Node

This is a term which is used to include both GGSN (Gateway GPRS Support Node) and SGSN (Serving GPRS Support Node).

GT - Global Title

The Global Title is an address used for routing in an SS7 network. The GT is used by the higher levels of SS7 (ISUP (ISDN User Part) TUP (Telephone User Part) SCCP (Signalling Connection Control Part) etc.) however a translation to point code is required at MTP (Message Transfer Part). The SCCP translation will also provide a SSN (Subsystem Number).

GTP - GPRS Tunnelling Protocol

GPRS Tunnelling Protocol is employed on the Gn interface in order to tunnel user data between different GSN (GPRS Support Node). Version zero of the protocol supports both signalling and user data under one generic header. It can be used with UDP (User Datagram Protocol) or TCP (Transmission Control Protocol) on the registered port 3386. GTP version one is used only on UDP. The control plane protocol GTP-C (Control) using registered port 2123 and the user plane protocol GTP-U (User) using registered port 2152.

GTP-C - GPRS Tunnelling Protocol Control

GPRS Tunnelling Protocol – Control plane messages are exchanged between GSN (Gateway Support Node) in a path. The control plane messages are used to transfer GSN capability information between GSN pairs, to create, update and delete GTP tunnels and for path management.

GTP-U - GPRS Tunnelling Protocol User

GPRS Tunnelling Protocol – User plane messages are exchanged between GSN (Gateway Support Node) pairs or GSN/ RNC (Radio Network Controller) pairs in a path. The user plane messages are used to carry user data packets, and signalling messages for path management and error indication.

GTP’ - GTP Prime

The GTP’ charging protocol is optional. GPRS nodes generate CDR (Call Detail Record). These CDR are to be collected by the CGF (Charging Gateway Function). The protocol GTP’ has been designed to provide this CDR transfer.

GTPv1-C - GPRS Tunnelling Protocol version 1 – Control

GTPv1-C is the control protocol used to establish, manage and release GTPv1-U tunnels, particularly as part of PDP (Packet Data Protocol) Context activation and management procedures on the Gn and Gp interfaces.

GTPv1-U - GPRS Tunnelling Protocol v1 – User

GTPv1-U is used to tunnel user plane data between different network nodes e.g. on the Gn, Gp, S1-U and S5 interfaces. GTPv1-U is used with UDP (User Datagram Protocol) and IPv4/IPv6 as supporting layers. In order to multiplex multiple users onto the same transport bearer (port/IP address), TEIDs (Tunnel Endpoint Identifier) are used to differentiate one traffic stream from another (the TEID is simply a numerical identity which has to be unique for a given traffic stream). The receiving end side of a GTP tunnel locally assigns the TEID value that the transmitting side must use and vice versa, assuming bidirectional transmission. TEIDs will be negotiated during the establishment of the GTP tunnel, which is achieved using GTP-C (GPRS Tunnelling Protocol – Control).

GTPv2 - GPRS Tunnelling Protocol version 2

In LTE , GTP (GPRS Tunnelling Protocol) tunnels are used between two nodes communicating over a GTP based interface, to separate traffic into different communication flows. A GTP tunnel is identified in each node with a TEID (Tunnel Endpoint Identifier), an IP address and a UDP port number. The receiving end side of a GTP tunnel locally assigns the TEID value the transmitting side has to use. The GTPv2 include an updated control plane which enables control messages to be passed between the MME , S-GW , PDN GW etc.

GTPv2-C - GPRS Tunnelling Protocol v2 – Control

GTPv2-C is a control plane protocol typically found on interfaces in the EPC (Evolved Packet Core), such as the S11 and S5 interfaces. GTPv2-C’s primary roles include the establishment, modification and termination of EPS (Evolved Packet System) bearers across the EPC, both Default and Dedicated.

GTT - Global Title Translation

The routing address within an ISDN network is termed the point code. Global titles identify end terminals that may be beyond the ISDN network. To route information the Global Title is translated into a point code this is typically conducted at a STP (Signalling Transfer Point).

GUAMI - Globally Unique AMF ID

The GUAMI is used to uniquely identify an AMF within a 5G network. It is comprised of the MCC (Mobile Country Code), MNC (Mobile Network Code), AMF Region ID, AMF Set ID and AMF Pointer.

Guardband

A guardband is a narrow frequency band between adjacent channels. Guardbands are usually employed in FDM (Frequency Division Multiplexing) systems to avoid adjacent channel interference.

GUI - Graphical User Interface

Graphical User Interface was the term coined when windows based operating systems were integrated with mouse operation. The concept of buttons, scroll bars and point and click operations have enhanced the interface. This type of interface is deemed far more user friendly than the traditional command line and has opened the use of computers to many more users.

GUMMEI - Globally Unique MME Identifier

The GUTI (Globally Unique Temporary Identity) has two main components, the GUMMEI (Globally Unique MME Identifier) that uniquely identifies the MME that allocated the GUTI and the M-TMSI (M-Temporary Mobile Subscriber Identity) that provides for an unambiguous identity of the UE within this MME.

GUP - Generic User Profile

The objective of the GUP (Generic User Profile) is to provide a conceptual description to enable harmonized usage of the user-related information located in different entities. That is, subscriber information held across a number of databases can be collated and accessed in a uniform manner using the GUP architecture.

GUTI - Globally Unique Temporary ID

In LTE the GUTI is allocated to the UE by the MME and has two components. These are the GUMMEI (Globally Unique MME ID) and the M-TMSI (MME-TMSI). While the GUMMEI identifies the MME, the M-TMSI identifies the UE within the MME.

GZIP

GZIP is a free compression algorithm employed on operating systems such as Linux , UNIX and Windows in order to reduce the size of files for storage and transmission. Other popular compression systems include WinZip, and PKZip.

H Channel

The H channel is a primary rate ISDN interface designed for video conferencing. The channel rates vary between 384Kbps and 1,920Kbps. The H channels are achieved by ganging together basic 64Kbps ISDN channels.

H.221

H.221 is a framing recommendation and is part of the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) H.320 video interoperability standards. It specifies the framing employed during synchronous video operation over individual ISDN (Integrated Services Digital Network) B channels ganged together into a 384Kbps H0 channels. H.222 specifies the format of video steams employing MPEG (Moving Picture Experts Group) 2 compression.

H.225

This is an ITU-T (International Telecommunications Union – Telecommunications Standardization Sector) standard that governs H.225 session establishment and packetization. The standard describes several different protocols including Q.931 and RTP (Real time Transport Protocol).

H.230

H.230 defines how individual audio/visual streams may be multiplexed onto a digital channel.

H.242

H.242 is part of the H.323 group of standards for real time data over packet switched networks. H.242 defines the protocol for the establishment, maintenance and tear down of audio channels under the H.323 framework.

H.244

H.244 specifies how two audio channels may be aggregated onto a B channel, in effect achieving half rate channels.

H.245

The H.245 protocol is used to set up the bearer capabilities, media types and media channels. It is also used to open the call.

H.248

H.248 is the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) specified MGCP (Media Gateway Control Protocol). It has been specified in conjunction with the IETF (Internet Engineering Task Force). H.248 employs ASN.1 (Abstract Syntax Notation 1) whereas the IETF version of MGCP titled MEGACO (Media Gateway Control) employs a text based version of the protocol. Since the initial development of H.248, the IETF have relinquished any further development responsibility to the ITU.

H.248 GCP - Gateway Control Protocol

The H.248 standard was initially a collaborative project between the ITU-T and the IETF (Internet Engineering Task Force), with the ITU now holding overall responsibility for the protocol. H.248 is a media gateway control protocol which is used to create, modify and delete media streams across a MGW (Media Gateway), in addition to negotiating the media formats to be used. Transactions which carry the various H.248 commands are relative to contexts, which are created on an individual basis for each media stream being processed by the MGW.

H.261

H.261 specifies the video codec algorithms, picture format and FEC (Forward Error Correction) methods to allow codecs from different manufacturers to interoperate. This specification of codec is employed within the H.323 family of standards.

H.263

The H.263 is an enhanced form of H.261 video codec.

H.320

H.320 is part of the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) standard for video conferencing. It specifies how the two B channels on the ISDN (Integrated Services Digital Network) basic rate service may be ganged together to offer a 128Kbps video channel.

H.323

H.323 specifies how real time services may be implemented over IP networks. The 3 steps include H.225 signalling for agents to request access to the H.323 domain. H.245 signalling is then employed for call setup, including the media streams to be used. Finally data is transported using RTP (Real Time Protocol).

H0 Channel

A H0 (zero) channel comprises six contiguous time slots on a T1 line. This gives a capacity of 384Kbps.

H10 Channel

The H10 channel is used in North America as a primary rate channel. It uses 23,64Kbps channels from the T1 primary rate carrier. The H10 has a capacity of 1472Kbps.

H11 Channel

The H11 channel uses all 24 timeslots on the T1 primary rate channel. This offers a data channel with a capacity of 1536Kbps.

H12 Channel

The H12 is the European primary rate channel employing all 30 time slots on an E1 primary rate carrier. This offers a channel capacity of 1920Kbps.

HA - Home Agent

The Home Agent is the function within the MIP (Mobile IP) architecture responsible for routing data to mobile nodes currently attached to a foreign network. This is achieved through a tunnelling process in which a CoA (Care-of-Address) is used to deliver the data to the mobile node. This CoA may be associated with a FA (Foreign Agent), in which case it is termed a FA CoA; or, it may be a co-located CoA meaning the mobile node is allocated an IP address in the foreign network.

HAA - Home Agent MIP Answer

The HAA is a MIP Diameter Application message, passed from the Home Agent to the Home Diameter Server. It is used in the MIP registration process and the variable associated with the MIP Registration Reply. These include the Home Address, Home Agent Address, and the relevant security keys to be used by the FA and Mobile Node for signalling and bulk encryption of data between these entities.

Half Duplex

A half duplex circuit is capable of transmission in both directions, but not at the same time. A typical example of a half duplex service is that provided by a speaker phone.

HaLow

This is the common term of the IEEE 802.11ah amendment to the Wi-Fi standards (IEEE 802.11-2012) that supports sub 1GHz radio frequencies to provide extended range / coverage when compared to conventional Wi-Fi networks operating in the 2.4GHz and 5GHz ISM bands. This technology supports low energy consumption which has significant benefits for remote / difficult to access sensors within the IoT (Internet of Things).

Hamming Code

Hamming codes, invented by R Hamming of Bell Labs, are used to generate FEC (Forward Error Correction) data. The codes are compiled using a matrix, in which information and parity bits are combined in order to provide error checking and correction at the receiver. The basic code generates three parity bits for every four information bits, whereas extended hamming codes increase the size of the matrix.

Handoff / Handover

A Handoff, or Handover, is the process in which a cellular phone is handed from one cell to the next in order to maintain a radio connection with the network. The variables that dictate a handover depend on the type of cellular system. In CDMA (Code Division Multiple Access) based systems interference requirements are the limiting factor for handover. In FDMA (Frequency Division Multiple Access) and TDMA (Time Division Multiple Access) systems such as GSM the main limiting factor is the signal quality available to the MS (Mobile Station). Other factors include distance TA (Timing Advance), loading, and received power levels.

Handover Word

The Handover Word is a GPS (Global Positioning System) variable used to enable a GPS receiver to switch from the course acquisition code to the precision code.

HAR - Home Agent MIP Request

The HAR is a MIP Diameter Application message, passed from the Home Diameter Server to the Home Agent. It is used in the MIP registration process and the variable associated with the MIP Registration Request.

Hard Handover

A handoff, or handover, is the process in which a cellular phone is handed from one cell to the next in order to maintain a radio connection with the network. A hard handover results in the radio connection being broken between the network and the mobile, before a new radio connection is established with the network in the target cell. Hard handovers usually require a change of frequency.

HARQ - Hybrid Automatic Repeat Request

HARQ is an optimized ARQ mechanism designed to provide error correction and packet retransmission across a wireless interface.

HARQ Information

This includes the HARQ protocol related information for the corresponding HS-DSCH transmission, as well as information about the redundancy version. The number of bits defined are: – Hybrid-ARQ process number – 3 bits. – Redundancy version – 3 bits. – New-data indicator – 1 bit. – UE ID – 10 bits implicitly encoded, i.e.part of CRC attachment process.

Hashing

Hashing is a cryptographic term for a mathematical value used to summaries a much larger block of data. This summary is termed the digest. The digest is generated by passing the original data through the hashing function. Irrespective of the length of the original data block, the hash code or digest is of a uniform length.

Hayes AT Commands

The Hayes AT (ATtention) commands are a standard set of instructions for controlling a modem. They were developed in the mid 1980’s by Hayes Micro Computers, hence the name Hayes. Until then modems had been dumb, meaning that they had no memory, and could not be programmed. With the advent of the codes modems became far more functional. The Hayes command set is now regarded as a standard for modem control.

HCCA - Controlled Channel Access

The term HCCA is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancement. It is a component of the HCF and provides support for parameterized Quality of Service. It inherits some of the rules of the legacy PCF as well as introducing many additions. HCCA provides polled access to the Wireless Medium but unlike PCF operation, this may take place in both the CP and CFP.

HCF - Hybrid Coordination Function

The 802.11e Quality of Service facility defines a new coordination function termed HCF which is only used in QBSS but implemented in all QSTA. The HCF combines functions of the DCF and PCF with some enhanced specific mechanisms and frame subtypes to support the transfer of Quality of Service data across a WiFi network.

HCI - Host Controller Interface

The Host Controller Interface enables communication between the Bluetooth Host and the Bluetooth Device. If the Bluetooth host and device was fully integrated there would be no requirement for the HCI.

HCP - Host Controller Protocol

Defined by ETSI , the HCP supports communication between a contactless application residing on a SIM and an NFC enabled mobile phone. As such, the protocol spans the HCI. Communication across this interface also uses the SWP.

HCS - Hierarchical Cell Structure

This is a term typically used in GSM to describe the priority of cells within a mixed environment. That is when Macro, Micro, and Pico cells may be viewed as candidates for cell reselection the priority described by the HCS will be used in the associated calculations.

HDLC - High Level Data Link Control

HDLC is a Layer 2 protocol for point to point and multipoint delivery of data. The frame consists of flags to delimit the frame, along with addressing information and control information which is used when the protocol is employed in the acknowledged mode. Also included in the frame is a payload area and a CRC (Cyclic Redundancy Code). The protocol was originally developed by IBM variants include LAPB (Link Access Protocol Balanced) and LAPD (Link Access Protocol on the D Channel), as well as PPP (Point to Point Protocol).

HDML - Handheld Device Markup Language

Handheld Device Markup Language is a modified form of HTML (Hypertext Markup Language), and is deigned for use of wireless devices, or small computers such as PDA (Personal Digital Assistants). Like WML (Wireless Markup Language), HDML is formatted on cards which are smaller units of information than traditional HTML which uses pages. This small data unit is more suitable for viewing on handheld devices and is quicker to download onto wireless devices.

HDSL - High-bit-rate Digital Subscriber Line

High-bit-rate Digital Subscriber Line is the most mature of the xDSL family of protocols. It allows E1 / T1 rates to be achieved over two pair copper cable. The implementation of HDSL requires equipment both at the exchange and customer premises, but allows standard UTP (Unshielded Twisted Pair) cable to be employed with a maximum distance between the exchange and the customer premises of 12,000 feet.

HDTP - Hand held Device Transport Protocol

HDTP is optimized for the carriage of HDML (Handheld Device Markup Language) coded data. It is transported at Layer 4 and presents the HDML to the HDML interpreter in an appropriate format.

HE-VASP - Home Environment Value Added Service Provider

This is a VASP (Value Added Service Provider) that has an agreement with the Home Environment to provide services.

HEC - Header Error Control

The Header Error Control field is an 8bit CRC (Cyclic Redundancy Code) within the header of the ATM (Asynchronous Transfer Mode) cell. It is used to check the validity of the ATM cell control information.

Hello Packet

Hello Packets are passed between routers as part of network routing functions. They are used by routers in order to build a map of adjacent routers. These adjacencies are then used by routing algorithms to formulate routing tables.

HEMM - HCCA, EDCA Mixed Mode

The term HEMM is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancement. It defines the access policy within a TSPEC and states the use of both EDCA and HCCA.

HeNB - Home evolved Node B

The HeNB has almost identical functionality as an eNB within the E-UTRAN, but is designed to be deployed in a home/office location as part of a Femto Cell architecture. Like the eNB, the HeNB is responsible for all radio resource management, as well as allocation of user traffic to the downlink/uplink, security and relaying of higher layer NAS (Non Access Stratum) signalling to the MME (Mobility Management Entity). The HeNB backhauls traffic to the network via the S1 interface, appearing to the upstream network as a regular eNB. The upstream network may be an MME (Mobility Management Entity)/S-GW (Serving Gateway) or a HeNB-GW (HeNB Gateway).

HeNB-GW - HeNB Gateway

The HeNB-GW serves as a concentrator of large numbers of HeNB deployments, thus lightening connection requirements on the network. As such, HeNBs connect to the HeNB-GW via the S1 interface, with the HeNB-GW concatenating these links and connecting to the MME (Mobility Management Entity)/S-GW (Serving Gateway) also via the standard S1 interface.

HEO - Highly-Eccentric Orbiting

HEO satellites have a range of operational altitudes ranging from 7,000km to 45,000km. The higher point of HEO orbits is where the satellite is designed to be exploited. The inclination angle is chosen in order to compensate, either completely or partially the motion of the Earth. This then allows the satellite to cover different parts of the Earth, e.g. Western Europe, North America, or Northern Asia.

HEVC - Hegh Efficiency Video Coding

Also known as H.265 or MPEG-H Part 2, HEVC is an advanced video compression standard which supersedes the earlier H.264 AVC (Advanced Video Codec) standard. HEVC offers improved data compression when compared to AVC, whilst maintaining the same level of video quality. Alternatively, HEVC can operate at the same bitrate as AVC yet provide a much improved video quality.

HEVC - High Efficiency Video Coding

Also known as H.265 or MPEG-H Part 2, HEVC is an advanced video compression standard which supersedes the earlier H.264 AVC (Advanced Video Codec) standard. HEVC offers improved data compression when compared to AVC, whilst maintaining the same level of video quality. Alternatively, HEVC can operate at the same bitrate as AVC yet provide a much improved video quality.

HFN - Hyper Frame Number

In 2G/3G/4G radio access systems the HFN is used between the base station and the mobile to limit the number of bits used for sequencing over the radio interface. The number may also be used as part of the security process.

HFP - Hands-Free Profile

The Hands-Free Profile specification defines the interactions for hands free devices, for example cellular phone with a Bluetooth in-car kit. This profile provides means for both remote control of the device and voice connections.

HGW - Home Gateway

The HGW is the successor to the vastly popular STB however, where the STB has a dedicated role with respect to providing TV services, the HGW is designed to be a much more capable device. Features of the HGW may include: Control of IPTV services, CPE to network interface, IMS terminal, Media Storage, Advanced security, Femto Cell. As more and more service are delivered via IP transport networks, the HGW will see a considerable rise in popularity, particularly since many STB are not capable of handling the new generation of services.

Highest SR3 Frequency

Highest SR3 Frequency The SR3 (Spreading Rate 3) frequency that has the highest frequency assignment.

HiperAccess

HiperAccess is an ETSI (European Telecommunications Standards Institute), now 3GPP (Third Generation Partnership Project), standard used to provide outdoor, high speed (25Mbps typical data rate) fixed radio access to customer premises. The system is capable of supporting multi-media applications and will be operated in either licensed or licensed exempted spectrum – typically 5GHz.

HIPERLAN - HIghPErformance Radio Local Area Network

HIPERLAN is a wireless LAN standard developed by the BRAN (Broadband Radio Access Networks) division of ETSI. HIPERLAN defines a very efficient, high-speed wireless LAN technology that fully meets the requirements of Europe’s spectrum regulations. Similar to IEEE 802.11a , HIPERLAN/2 operates in the 5GHz spectrum and offers data rates of up to 54Mbps. While HIPERLAN appears to offer similar performance to that of WLAN 802.11a, it is far more efficient in terms of allocating users radio resources. Unfortunately 802.11a is already available, and operation within the UK has been ratified by the RA (Radiocommunications Agency). Due to this, and the economies of scale it will initially prove a far cheaper option than HIPERLAN. To this end it is viewed that WiFi derivatives such as 802.11a, b, g and n will become the dominant technologies.

HiperLan 2 - High Performance Radio LAN

HiperLan 2 is an ETSI (European Telecommunications Standards Institute), now 3GPP (Third Generation Partnership Project), standard used to specify broadband wireless LAN (Local Area Network). The carrier frequency of HiperLan is 5GHz, and supports data rates between 25Mbps and 54Mbps, Three profiles of the standard are specified. These are for corporate, public and domestic use.

HiperLan1 - High Performance Radio LAN

HiperLan 1 is an ETSI (European Telecommunications Standards Institute), now 3GPP (Third Generation Partnership Project), standard used to specify broadband wireless LAN (Local Area Network). The carrier frequency of HiperLan is 5GHz providing high speed (20Mbps typical gross data rate) radio local area network communications which are compatible with wired LAN (Local Area Network) such as Ethernet.

HiperLink

HyperLink is an ETSI (European Telecommunications Standards Institute), now 3GPP (Third Generation Partnership Project), standard used to provide very high speed (155Mbps data rate) radio links for static interconnections. The system is capable of supporting multi-media applications and will be operated at a frequency of 17GHz.

HLR - Home Location Register

The Home Location Register is a database within the HPLMN (Home Public Land Mobile Network). It provides routing information for MT (Mobile Terminated) calls and SMS (Short Message Service). It is also responsible for the maintenance of user subscription information. This is distributed to the relevant VLR (Visitor Location Register) or SGSN (Serving GPRS Support Node) through the attach process and mobility management procedures such as Location Area and Routing Area updates.

HLR - Home Location Register (3GPP2)

The Home Location Register is a database found within cellular networks. It stores subscriber data relating to services and features in addition to location area based information.

HLS - Higher Layer Split

HLS relates to the functional split option point in RAN deployments where the interconnectivity point between the centralised unit and the distributed units is located in the protocol stack from the MAC layer upwards.

HMAC - Hash Message Authentication Code

HMAC (Hash Message Authentication Code) provides data source authentication and data integrity if employed between two users.

HNB - Home Node B

A HNB can also be defined as a Femto Cell supporting the standard UMTS air interface. It provides cellular coverage in a subscriber’s home or small business yet connects back to the service providers core network via a broadband IP network running over the Iu-h interface. The HNB is defined in the 3GPP ‘s Release 8 specifications.

HNB-GW - Home Node B

The HNB-GW provides the point of interconnect between a HNB or Femto Cell and a service provider’s core network. As well as presenting an Iu-CS and Iu-PS interface towards an MSC and SGSN respectively, the HNB-GW also terminates the IPSec tunnel which spans the Iuh interface between itself and the HNB. The HNB-GW is defined in the 3GPP ‘s Release 8 specifications.

HOLD - Communication Hold

This is a supplementary service in which an ongoing communication session is paused.

Hold Mode

The Hold Mode is when a Bluetooth device is allocated a hold timer and is waiting for it to expire before continuing with its operation.

Hopping Pilot Beacon

Hopping Pilot Beacon A pilot beacon that changes CDMA (Code Division Multiple Access) Frequency periodically to simulate multiple BS (Base Station) operating on different frequencies. The transmission of the hopping pilot beacon is discontinuous on any CDMA Channel.

HOS - Home Operated Services

In order to understand which services are available in the mobile network and how those services can be correctly accessed, HOS acts as a configuration service between the mobile and the network.

Host Name Resolution

Host Name Resolution is the process in which an IP address is resolved from a host name. The best known host name resolution system is the DNS (Domain Name System).

HPLMN - Home Public Land Mobile Network

The Home Public Land Mobile Network identifies the PLMN (Public Land Mobile Network) in which the subscriber’s profile is held. Users roaming to other networks will receive subscription information from the HPLMN.

HR/DSSS PHY - High Rate / Direct Sequence Spread Spectrum Physical Layer

The HR/DSSS PHY is the enhanced physical layer defined by IEEE 802.11b which supports data transfer at up to 11Mbps. Unlike the earlier versions of IEEE 802.11 which supported data rates of up to 2Mbps, HR/DSSS uses complementary code keying which divides the chip stream into a number of 8bit code symbols.

HS - Home System

The wireless cellular system in which the MS (Mobile Station) subscribes for service.

HS-DPCCH - High Speed Dedicated Physical Control Channel

The HS-DPCCH carries uplink feedback signalling related to downlink HS-DSCH transmission. This feedback signalling consists of HARQ-ACK (Hybrid-ARQ Acknowledgement) and Channel Quality Indication. The latter is used to influence the scheduling at the Base Station.

HS-DSCH - High Speed Downlink Shared Channel

The HS-DSCH is evolved from the UMTS Release 99 DSCH (Downlink Shared Channel). It enables fast and flexible time multiplexing of different users. Its purpose is to increase data rates, as well as improve the spectral efficiency. DSCH features such as fast power control and variable spreading factor have been replaced in HS-DSCH Release 5, which instead utilizes: a short packet size, multi-code operation, as well as other techniques such as AMC (Adaptive Modulation and Coding)and HARQ.

HS-DSCH RNTI - HS-DSCH Radio Network Temporary Identity

This is used for the UE specific CRC (Cyclic Redundancy Check) on the HS-SCCH and HS-PDSCH. It is also identified as the H-RNTI. It is allocated by the CRNC upon the UE establishing a HS-DSCH channel and is unique within the cell carrying the HS-DSCH.

HS-PDSCH - High Speed Physical Downlink Shared Channel

The HS-PDSCH is used to carry the HS-DSCH (High Speed – Downlink Shared Channel)transport channel. Each HS-PDSCH corresponds to one channelization code of fixed spreading factor SF=16. It is also possible for a UE to be assigned multiple channelization codes in the same HS-PDSCH sub-frame, depending on its capability. The HS-PDSCH may use QPSK or 16QAM modulation.

HS-SCCH - High SpeedShared Control Channel

The HS-SCCH is a fixed rate downlink physical channel used to carry downlink signalling related to HS-DSCH transmission. It operates using a SF=128 channelization code, i.e. 60 kbps. The UE is provided one HS-SCCH set on HS-PDSCH configuration/re-configuration via RRC signalling. The number of HS-SCCH in a HS-SCCH set as seen from the UE’s point-of-view can range from a minimum of one HS-SCCH to a maximum of four HS-SCCHs, with the UE continuously monitoring all the HS-SCCHs in the allocated set. For each HS-DSCH TTI , each HS-SCCH carries HS-DSCH related signalling for one UE.

HSCSD - High Speed Circuit Switched Data

High Speed Circuit Switched Data enhances the capabilities of the current GSM network by combining time slots on the GSM radio carrier. Data rates of 14.4Kbps, using one timeslot, 28.8Kbps using two time slots, or 57.6Kbps using four time slots can be achieved. HSCSD is best suited for services such as video conferencing.

HSDPA - High Speed Downlink Packet Access

HSDPA improves system capacity and increases user data rates in the downlink direction, that is, transmission from the Radio Access Network to the mobile terminal. The processes of adaptive modulation and coding, the procedures by which HSDPA data is scheduled for transmission across the air interface and improved re-transmission patterns all contribute to the improved data rates.

HSN - Hopping Sequence Number

Frequency hopping is employed in frequency division spread spectrum to hide the data channels in the noise or to avoid interference from other users of the common spectrum. It is also employed in fading channels to improve the quality of the radio connection. The hopping pattern must be known both by the receiver and the transmitter. This pattern is described using a hopping sequence and identified by the HSN.

HSPA+ - High Speed Packet Access+

HSPA+ was defined as part of the 3GPP Release 7 specifications. HSPA+ employs MIMO technologies and higher order modulation to enhance the uplink and downlink data rates of the 3G packet channels. HSPA+ also introduces an optional all-IP architecture for the network, where base stations are directly connected to IP based backhaul and then to the ISP ‘s edge routers known as GGSN s.

HSS - Home Subscriber Server

The HSS is the master database for a given subscriber, acting as a central repository of information for network nodes. Subscriber related information held by the HSS includes user identification, security, location and subscription profile. The HSS is a functional element of LTE and IMS.

HSSI - High Speed Serial Interface

The High Speed Serial Interface supports data rates up to 52Mbps. It is typically used to connect ATM (Asynchronous Transfer Mode) switches on a T3 carrier.

HSUPA - High Speed Uplink Packet Access

HSUPA (High Speed Uplink Packet Access), or FDD Enhanced Uplink, is designed to improve the performance of uplink dedicated transport channels. Like HSDPA (High Speed Downlink Packet Access), it offers increase data rates, whilst at the same time improving capacity. The FDD Enhanced Uplink upgrade is designed to improve the performance of uplink dedicated transport channels, i.e. to increase capacity and throughput and reduce delay. In order to achieve this three main changes are identified: Node B controlled scheduling – Under the supervision of the RNC, the Node B is able to control the set of TFC (Transport Format Combinations) from which the UE may choose; Hybrid ARQ – this enables the rapid retransmissions of erroneously received data packets between UE and Node B; Shorter TTI (Time Transmission Interval) – the enhanced uplink channel is able to operate with a TTI of 2ms or 10ms.

HTCP - Hypertext Caching Protocol

The Hypertext Caching Protocol is employed within internets to identify HTTP (Hypertext Transport Protocol) proxies used to cache, typically web data.

HTG - Hunt Group

A Hunt Group is a supplementary service in which a group of fixed or mobile telephones are defined. An incoming call will be passed from phone to phone until the call is accepted.

HTI - Host Terminal Interface

The Host Terminal Interface is the Interface between a Bluetooth Host and a Bluetooth Unit.

HTML - Hypertext Markup Language

Hypertext Markup Language is an authoring language in which tags are used to format data and pictures on the HTML page. In addition, commands to download applications, generate hyperlinks and provide dynamic user interaction may also be included. These tags and commands are interpreted by the user’s browser in order to display data, or initiate actions based on the HTML commands.

HTS - High Throughput Satellite

HTS (High Throughput Satellite) systems utilize spot beams to provide broadband services to end users with bit rates in excess of 100Mbps.

HTTP – XCAP - Hypertext Transfer Protocol (XCAP)

In the context of the Ut interface, HTTP is used in support of XCAP (XML Configuration Access Protocol) operation, which allows subscribers to remotely access and manipulate configuration files stored on Application Servers in the network. In essence, an XML configuration file can be broken up into unique URLs, after which point regular HTTP expressions such as GET and PUT can be used by the mobile to access and alter the XML configuration as necessary.

HUB

A Hub is a Layer 1 function used to connect parts of a LAN (Local Area Network) together. Along with connectivity it also regenerates the signal, which improves the range of the LAN.

HV - High quality Voice

The HV (High Quality Voice) indicates a Bluetooth packet which has been defined so it can support high quality voice on a SCO (Synchronous Connection Oriented) link. Three different types of high quality voice packets are identified; these are known as HV1 packets (1 slot), HV2 packets (2 slot) and HV3 packets (3 slot).

Hyperframe

Hyperframe A Hyperframe is a hierarchical frame structure. In GSM the Hyperframe is either 2048 (normal) or 1024 (classic) Superframes , this depends on the configuration.

I - Information Fames

Information frames are used to carry user information or signalling data across a link.

I-CSCF - Interrogating – Call Session Control Function

The I-CSCF is responsible for onward routing of SIP messages to the appropriate S-CSCF (Serving CSCF) for a given subscriber. This routing capability is utilised in specific scenarios only, such as during registration in order to assign or ascertain the S-CSCF which should be used. Routing SIP requests arriving from other SIP networks is also a responsibility of the I-CSCF. The I-CSCF queries the HSS in order to discover the S-CSCF a particular subscriber has been assigned to.

i-mode

i -mode is a Japanese mobile phone service from NTT (Nippon Telegraph and Telephone Corporation) DoCoMo which allows users to access many multimedia services from their handsets. In Japan , the system supports web browsing to more than 40,000 sites, email, online shopping and banking etc.

I-SBC - Interconnect Session Border Controller

An Interconnect SBC typically sits on the border between two IMS or SIP networks. In this role, the I-SBC conducts a variety of functions, including security, traffic scrubbing, address manipulation and media transcoding (amongst other functions).

I2RS - Interface to Routing System

The IETF’s I2RS protocol is a potential solution for the Southbound API associated with the Software Defined Networking architecture. I2RS retains the use of traditional routing protocols such as OSPF (Open Shortest Path First) and BGP (Border Gateway Protocol) between network resources. The Southbound API is used as a mechanism to dynamically modify routing decisions to suit specific SDN Applications. However, normal routing decisions are still based on traditional routing protocols exchanged on an East-West basis between Network Resources.

IA5 - International Alphabet 5

International Alphabet 5 is an international standard alphanumeric code which has a facility for national options. The USA version is called ASCII (American Standard Code for Information Interchange).

IAB - Internet Architecture Board

The Internet Architecture Board comprises of researchers who discuss issues pertinent to the architecture of the Internet. They are also responsible for appointing a variety of Internet-related groups, such as the ICANN (Internet Corporation for Assigned Names and Numbers), IESG (Internet Engineering Steering Group), and IRSG (Internet Research Steering Group). The IAB is appointed by the trustees of the ISOC (Internet Society).

IAC - Inquiry Access Code

The Inquiry Access Code is used in Bluetooth inquiry procedures. There are two types: DIAC (Dedicated IAC), which is used for specific devices, or GIAC (Generic IAC) for all devices.

IAM - Initial Address Message

An Initial Address Message can be found in SS7 (Signalling System No.7) signalling networks as part of the ISUP (Integrated Services Digital Network User Part) call set up. The message is used to seize a circuit and transfer addressing and call handling / routing information.

IANA - Internet Assigned Numbers Authority

The IANA allocates and maintains unique codes and numbering systems that are used in the technical standards that drive the Internet (termed RFC ). For example, the IANA oversees Port Number allocations. Responsibilities of the IANA include: Management of the DNS Root, .int and .arpa domains, Coordination and allocation of global IP Address and AS Number pool, Protocol numbering assignment.

IAPP - Inter Access Point Protocol

Within an IEEE 802.11 network, Stations may roam between different AP (Access Points). In order to ensure all relevant information is delivered to the correct AP to which the station is associated, an Inter Access Point Protocol is required. This protocol, which is often proprietary, enables multiple AP to communicate and pass information regarding the location of associated Stations.

IARI - IMS Application Reference Identifier

An IARI is used to uniquely identify an IMS application. IMS applications provide an IMS service which utilize established IMS Communication Services in order to provide a specific service to the customer. An example IARI for geolocation services would be +g.3gpp.iari-ref=”urn%3Aurn-7%3A3gpp-application.ims.iari.rcs.geopush”

IARP - Inter APN Routing Policy

Information provided by the ANDSF which tells the mobile which traffic should be sent across which PDN connections, and also which traffic should undergo non-seamless offload (bypassing the EPC).

IBCF - Interconnection Border Control Function

The IBCF is a SIP (Session Initiation Protocol) ALG (Application Level Gateway) which is designed to facilitate interconnection between two service provider domains. Similar in role to a SBC (Session Border Controller), the IBCF performs functions such as IPv4 to IPv6 interworking, network topology hiding, SIP message screening and transport plane control via the TrGW (Transition Gateway).

IBSS - Independent Basic Service Set

An Independent Basic Service Set or ad hoc network is the simplest of all IEEE 802.11 networks in that no network infrastructure is required. As such, an IBSS is simply comprised of one or more Stations which communicate directly with each other. The abbreviation should NOT be confused with an Infrastructure BSS (Basic Service Set).

ICANN - Internet Corporation for Assigned Names Numbers

ICANN oversees the IANA and as such supervises the allocation of IP Addressing and domain names, ensuring uniqueness in both areas and hence driving the smooth operation of the Internet and WWW.

ICE - Interactive Connectivity Establishment

ICE is a NAT Traversal mechanism which incorporates both the STUN and TURN protocols. Developed by the IETF MMUSIC working group, ICE is deployed in many next generation networks to allow VoIP users positioned behind a NAT device to send signalling to other VOIP users. Crucially, this signalling contains addressing information which is useable, due to the fact that prior to sending the signalling, the VoIP client will have interrogated an ICE server to ascertain the addressing information required for the eventual media streams.

ICID - IM CN subsystem Charging Identifier

The ICID is used within the IMS (IP Multimedia Subsystem) to correlate session level charging information in both the visited and home networks. It is generated at the edge of the IMS, either by the P-CSCF (Proxy – Call Session Control Function) in the case of MO (Mobile Originated) sessions and the I-CSCF (Interrogating – Call Session Control Function) for MT (Mobile Terminated) sessions. All subsequent billable events for the session are associated with this identifier.

ICMP - Internet Control Message Protocol

The Internet Control Message Protocol is a Layer 2 protocol that reports errors and provides other information relevant to IP packet processing. The protocol is described in RFC (Request For Comments) 792.

ICS - IMS Centralized Services

ICS is a option for service providers who wish to anchor all of their call control within the IMS, despite the fact that users may be on CS access when they make or receive a call.

ICSI - IMS Communication Service Identifier

Any IMS Communication Service must be identified using an ICSI. As an example, the IMS MMTel Communication Service (upon which VoLTE is based), is identified using the urn-xxx:3gpp-service.ims.icsi.mmtel ICSI.

ICV - Integrity Check Value

The ICV (Integrity Check Value) is the result of the Integrity process. This normally involves the HMAC (Hash Message Authentication Code) algorithm and the MD5 (Message Digest 5) or SHA-1 hash functions.

ID - Identity

A generic term used by most telecom systems. This may be used to identify such things as a user, phone, network, channel, area, etc.

IDD - International Direct Dial

International Direct Dial is an international number which can be dialled directly by the user. As such, it will include the international prefix for the country e.g. +44 (United Kingdom), +1 (United States of America), +33 (France), +91 (India), +86 (China) etc.

Idle Handoff

Idle Handoff The act of transferring reception of the PCH (Paging Channel), BCCH (Broadcast Control Channel) or the FCCCH (Forward Common Control Channel) from one base station to another when the MS (Mobile Station) is in the Idle State.

Idle mode or Idle State

Whilst in GSM or UMTS idle mode, a mobile shall implement the cell selection and reselection procedures. The mobile has registered on the network, and is listening for paging messages. The mobile will be performing location area updates when necessary. The idle state in GRPS indicates that the mobile has not yet registered onto the network or is switched off.

IDN - Integrated Digital Network

An Integrated Digital Network is a public telecommunication network which uses digital transmission and signalling.

IDS - Intrusion Detection System

An IDS is a security countermeasure that monitors traffic and events looking for signs of intruders. Host-based IDS monitors system events, log files etc, whereas Network based IDS monitors network traffic patterns and also suspicious events such as multiple failed login attempts.

IE - Information Element

An Information Element is a group of information which may be included within a signalling message or data flow which is sent across an interface. Examples may include QoS (Quality of Service) definitions, setup parameters, user identifiers etc.

IEEE - Institute of Electrical and Electronics Engineers

The Institute of Electrical and Electronics Engineers is a professional organization whose activities include the development of communications and network standards.

IEEE 802.1 - Bridging Management

The IEEE 802.1 standards cover 802 LAN (Local Area Network) and MAN (Metropolitan Area Network) architecture, internet working among 802 LAN, MAN and other wide area networks, 802 overall network management, and protocol layers above the MAC (Medium Access Control) LLC (Logical Link Control) layers.

IEEE 802.10 - SILS (Standards for Interoperable LAN/MAN Security)

The IEEE 802.10 specification defines an interoperable data link layer security protocol and associated security services. The 802.10 standards provide: security association management, key management (manual and certificate based), security labeling, security services (data confidentiality, connectionless integrity, data origin authentication, and access control).

IEEE 802.11

IEEE 802.11 are the collection of standards relating to Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) specifications. WiFi is widely used to encompass this collection of standards and replace the 802.11 term. WiFi networks, when compared to their cellular cousins, are far simpler in design and consist of only four major physical elements: the Station, Wireless Medium, Access Point and Distribution System.

IEEE 802.11 Wireless - IEEE 802.11

This is an IEEE (Institute of Electrical and Electronic Engineers) technical standard covering WLAN (Wireless Local Area Network) technology. The standards have been divided into sub groups including 802.11a, 802.11b, 802.11g, 802.11n and 802.11ac.

IEEE 802.11a

Part of the IEEE 802.11 family of specifications, this wireless local area network technology is comprised of a high speed physical layer operating in the 5GHz unlicensed band and supports data rates up to 54Mbps.

IEEE 802.11ac

Part of the IEEE 802.11 family of specifications, this enhancement of the physical layer supports data rates of up to 6.9Gbps using MIMO. The technology only operates at within the 5GHz radio spectrum band using a range of channel bandwidths: 20MHz, 40MHz, 80MHz and 160MHz.

IEEE 802.11ad

Part of the IEEE family of Wi-Fi standards, 802.11ad networks support incredibly fast data throughput rates by using high radio frequency bands around 60GHz. Unfortunately, this significantly reduces the distance between transmitter and receiver.

IEEE 802.11af

White-Fi or more accurately 802.11af enables WiFi operation in TV white space spectrum in the VHF (Very High Frequency) and UHF (Ultra High Frequency) bands between 54MHz and 790MHz. Approved in 2014, the amendment supports cognitive radio techniques to minimize interference to the primary users of the radio spectrum, namely analogue and digital television and wireless microphones.

IEEE 802.11ah

Part of the IEEE family of Wi-Fi standards, 802.11ah networks have been designed to operate within the license exempt radio frequency bands sub 1GHz to improve coverage and power saving. Also known as Wi-Fi HaLow, this technology is aimed at IoT (Internet of Things) type deployments.

IEEE 802.11ax

The IEEE 802.11ax standard is the successor to 802.11ac, but unlike its predecessor, it can operate on both the 2.4GHz and 5GHz radio frequency bands. The Wi-Fi technology is targeting at least a four times improvement in data throughput and is expected to operate in highly dense usage environments. This technology is also known as Wi-Fi 6.

IEEE 802.11b

Part of the IEEE 802.11 family of specifications, IEEE 802.11b was initially the most popular wireless networking technology. The equipment operates in the 2.4GHz unlicensed band and utilizes HR/DSSS (High Rate – Direct Sequence Spread Spectrum) enabling data rates of up to 11Mbps to be achieved.

IEEE 802.11d

Part of the IEEE 802.11 family of wireless local area network specifications, the IEEE 802.11d task group covers additional regulatory domains.

IEEE 802.11e

Part of the IEEE 802.11 family of wireless local area network specifications, the IEEE 802.11e task group covers QoS (Quality of Service) issues.

IEEE 802.11f

Part of the IEEE 802.11 family of wireless local area network specifications, the IEEE 802.11f task group is responsible for the Inter Access Point Protocol.

IEEE 802.11g

Part of the IEEE 802.11 family of wireless local area network specifications, the IEEE 802.11g task group is responsible for the specification enabling higher data rates (54Mbps) to be achieved in the 2.4GHz unlicensed radio band.

IEEE 802.11h

Part of the IEEE 802.11 family of wireless local area network specifications, the IEEE 802.11h task group is responsible for dynamic channel selection and transmission power control.

IEEE 802.11i

Part of the IEEE 802.11 family of wireless local area network specifications, the 802.11i task group was responsible for developing a new standard for WLAN security to replace the weak WEP (Wired Equivalent Privacy). The IEEE 802.11i standard utilizes the authentication schemes of 802.1X and EAP (Extensible Authentication Protocol) in addition to a new encryption scheme – AES (Advanced Encryption Standard) and dynamic key distribution scheme – TKIP (Temporal Key Integrity Protocol).

IEEE 802.11k - IEEE 802,11k

Part of the IEEE 802.11 family of specifications and ratified in 2008, this amendment improved the way traffic is distributed within a WiFi network. Rather than a Station simply selecting the Access Point with the best signal, this amendment enables networks to prioritize underutilized Access Points instead.

IEEE 802.11n

Part of the IEEE 802.11 family of wireless local area network specifications, the IEEE 802.11n task group define modifications to the Physical and MAC layers in order to deliver 100Mbps data rates (operating at 2.4GHz or 5GHz frequency). The working group put forward a number of enhancements to achieve these higher data rates including support for MIMO and the use of two adjacent 20MHz channels. Equipment complying with the 802.11n standard is also backward compatible with the earlier 802.11a , 802.11b and 802.11g variants.

IEEE 802.11r

Part of the IEEE 802.11 family of specifications and ratified in 2008, the 802.11r amendment sets out to improve the mechanism for a handoff / handover between two Access Points. This was necessary due to the increased signalling between the Station and Access Point brought about by the introduction of 802.11i and 802.11e amendments.

IEEE 802.11u

Part of the IEEE 802.11 family of specifications, this amendment to the 802.11-2007 standard incorporates a number of features to aid interworking with external networks such as WiFi hotspots.

IEEE 802.11v

Part of the IEEE 802.11 family of specifications, this amendment enables client devices to exchange information about the network topology including the radio frequency environment.

IEEE 802.11w

Part of the IEEE 802.11 family of specifications, this amendment added to the security enhancements made in 802.11i by increasing the security of management frames.

IEEE 802.12 - Demand Priority Access

The IEEE 802.12 standards define the protocol and compatible interconnection of data communication equipment via a repeater-controlled, star-topology LAN (Local Area Network) using the demand-priority access method. This provides a round-robin arbitration method to provide LAN access based on message priority level.

IEEE 802.15 Wireless Personal Area Networks

The IEEE 802.15 standards define a PAN (Personal Area Network) for short distance wireless networks. This is commonly known as Bluetooth.

IEEE 802.16 Broadband Wireless Metropolitan Area Networks

The IEEE 802.16 defines the Wireless MAN air interface standard. This provides a highly efficient use of bandwidth and supports voice, video and data services and is commonly referred to as WiMAX.

IEEE 802.1X

802.1X is a security standard adopted by the IEEE which has received widespread industry support. It uses the EAP (Extensible Authentication Protocol) and RADIUS (Remote Authentication Dial-In User Service) to authenticate clients and distribute keys.

IEEE 802.2 - LLC (Logical Link Control)

An IEEE 802 local area network can perform a best effort datagram service, which is enough for some IP packets. The IEEE 802.2 standards define the LLC (Logical Link Control), which identifies four distinct classes of LLC operation enabling it to control the levels of service. Class I provides the data-link connectionless-mode service only. Class 2 provides the data-link-connection-mode service plus data-link-connectionless- mode service. Class 3 provides the acknowledged-connectionless-mode service plus data-link-connectionless-mode service. Class 4 provides the acknowledged-connectionless-mode service plus data-link connection-mode service plus data-link-connectionless-mode service

IEEE 802.3

IEEE (Institute of Electrical and Electronics Engineers) 802.3 is a LAN (Local Area Network) protocol that specifies an implementation of the physical layer and the MAC (Medium Access Control) sublayer of the data link layer. IEEE 802.3 uses CSMA/CD (Carrier Sense Multiple Access with Collision Detection) access at a variety of speeds over a variety of physical media. Variations of IEEE 802.3 include 10Base2, 10Base5 and 10BaseT.

IEEE 802.4 - Token-Passing Bus Access Method

The IEEE 802.4 standard defines a bus physical topology which uses a token message to grant the right to access the physical network media.

IEEE 802.5 - Token Ring Access Method

The IEEE 802.5 standard defines a network topology based on a logical ring with token-based media access control. This standard defines data rates of 1Mbps, 4Mbps and 16Mbps.

IEEE 802.6 - DQDB Access Method

The IEEE 802.6 standard describes a MAN (Metropolitan Area Network) standard called DQDB (Distributed Queue Dual Bus). The network is defined as a high-speed shared medium access protocol for use over a dual, counter-flowing, unidirectional bus networks. The use of paired bus provides a failure tolerant configuration. DQDB is able to carry data, voice, and video transmissions, with bandwidth being allocated using time slots on the bus.

IEEE 802.7 - Broadband LAN

The IEEE 802.7 standard identifies the recommended practices for Broadband Local Area Networks. It specifies the design, installation, and test parameters for a broadband cable medium.

IEEE 802.9 - Isochronous LAN

The IEEE 802.9 standard defines an Isochronous Ethernet (IsoEnet) and is designed to carry bursty and time critical traffic. The system bandwidth is 16Mbps, which is identified as a 10Mbps asynchronous channel and ninety six 64Kbps channels, available for specific data streams.

IEI - Information Element Identifier

An Information Element Identifier is a unique identity which enables a given information element to be determined within the operating context.

IESG - Internet Engineering Steering Group

The Internet Engineering Steering Group forms part of the IETF (Internet Engineering Task Force) and is comprised of the IETF Chairman and the Area Managers of each of the associated working groups.

IETF - Internet Engineering Task Force

The Internet Engineering Task Force consists of more than 80 working groups responsible for developing Internet standards.

ifc - Initial Filter Criteria

ifc are associated with a particular IMS service profile, stored in the HSS and installed in the S-CSCF during registration. ifcs contain parameters which form part of a filter. When these parameters are identified within an incoming SIP message, the S-CSCF can use ifc to determine the next hop forwarding action.

IFL - International Frequency List

The International Frequency List is published by the ITU (International Telecommunications Union) and specifies the allocated use of radio frequencies.

IFOM - IP Flow Mobility

IFOM is a technique used in WiFi offload to allow selective traffic offload, allowing some traffic streams to traverse the LTE network whilst others traverse the WiFi network.

IGMP - Internet Group Management Protocol

This is the protocol used by network hosts to express the desire to join or leave a particular multicast group. For example, in an IPTV scenario, a subscriber changing channel will leave one multicast group and join a different multicast group. IGMP is typically found operating over the last hop in the IP network, between the host device and the router that device is connected to. In the multicast network, PIM is used to allow multicast routers to join and leave multicast groups, as and when they are required to forward or stop forwarding multicast traffic to a particular recipient.

IGP - Interior Gateway Protocol

An Interior Gateway Protocol is used to exchange routing information within an autonomous system. Examples of IGP include OSPF (Open Shortest Path First) and RIP (Routing Information Protocol).

IID - Invoke ID

The IID is a reference number allocated by CAP in order to correlate CAP messages with the relevant Invoke Component within the TCAP Component Sub Layer.

IK - Integrity Key

A 128bit number used to protect the integrity of information passing between the RNC (Radio Network Controller) and the UE (User Equipment) in UMTS.

IKE - Internet Key Exchange

Internet Key Exchange is a mechanism for securely exchanging key information across an unsecure IP network. Primarily used in support of IPSec security association establishment, IKE employs Diffie Hellman key exchange to establish an initial security association, after which this can be used to set up further security associations.

IKEv2 - Internet Key Exchange Protocol Version 2

IKEv2 is a component of IPsec used for performing mutual authentication and establishing and maintaining Security Associations (SAs). These SAs include shared secret information that can be used to efficiently establish SAs for ESP (Encapsulating Security Payload) or AH (Authentication Header) and a set of cryptographic algorithms to be used by the SAs to protect the traffic that they carry. With IKEv2, a SA is first established in order to protect and transport IKEv2 traffic. After this point, Child SAs can then be established in order to protect other traffic types.

ILMI - Integrated Local Management Interface

Provides a mechanism for ATM-attached devices, such as hosts, routers, and ATM switches, to transfer management information. It is based on the SNMP (Simple Network Management Protocol).

IM - Instant Messaging

IM is a service which involves the exchange of typically short messages between point to point or point to multipoint parties. Predominantly developed and used across the Internet, IM services are now being adopted by telecommunications service providers as a means of enriching current service offerings. Generally, IM exchanges do not require a session to be established between sender and receiver.

IM CN - IP Multimedia Core Network

The term IM when related to the IMS (IP Multimedia Subsystem) is normally added to other terms such as network functions within the Core Network, i.e. IM CN to indicate that these functions are enabled to support IMS operation.

IM-AG - IMS Access Gateway

In the 3GPP IMS (IP Multimedia Subsystem) architecture, the IM-AG is a network functional entity which is incorporated into the functionality of the IBCF (Interconnection Border Control Function). The role of the IM-AG is to ensure that addressing associated with inbound and outbound media streams is correct, which is essentially a NAT (Network Address Translation) function. The IM-AG is also referred to as the TrGW (Transition Gateway).

IM-CSI - IM – CAMEL Subscription Information

If an IMS subscriber has access to CAMEL services this will be indicated through IM-CSI (IM – CAMEL Subscription Information). This information is stored in the HSS and is passed on by the S-CSCF to the relevant IM-SSF.

IM-MGW - IMS – Media Gateway

The IM-MGW handles the media plane (voice) bearer as part of an IP based call. Controlled by an MGCF (Media Gateway Control Function), the IM-MGW will provide CS/PS media stream termination, transcoding and conversion services.

IM-SSF - IP Multimedia – Service Switching Function

The IM Basic Call State Models are used to define the call processing architecture within the IMS that is recognizable to the CSE and are identical to those defined for call control in traditional network functions such as the MSC (Mobile Switching Centre). The Basic Call State Models are logically located within the IM-SSF which performs the mapping process between SIP methods passed across the ISC and Detection Points that will be used to initiate dialogue with the CSE.

IMA - Inverse Multiplexing over ATM

The IMA (Inverse Multiplexing over ATM ) protocol allows multiple E1 links to be used as a group to provide an aggregate bandwidth. The ATM (Asynchronous Transfer Mode) transmission protocol is already used to carry all of the signalling, voice and data information for many networks, e.g. 3G mobile networks. The use of IMA ensures that the bandwidth from each E1 link is proportionally used. This avoids any one link becoming a bottleneck to the service. When additional bandwidth is required an extra link can be added with little or no management of the ATM or application layers required.

IMAP - Internet Message Access Protocol

The Internet Message Access Protocol provides a method of accessing e-mail or bulletin board messages kept on a mail server. IMAP permits client e-mail applications to access remote message stores as if they were local, without actually transferring the message.

IMAP4 - Internet Message Access Protocol 4

The Internet Message Access Protocol 4 is an IETF (Internet Engineering Task Force) which allows users to create and manage mail folders over a network by scanning message headers and downloading selected messages.

IMC - IMS Credentials

IMC is a means by which a non 3GPP device can store IMS related information, such as Private/Public ID and IMS security information.

IMEI - International Mobile Equipment Identity

The International Mobile Equipment Identity is a unique identifier allocated to each ME (Mobile Equipment). It consists of a TAC (Type Approval Code), a FAC (Final Assembly Code), SNR (Serial Number) and a Spare Digit.

IMEISV - International Mobile Equipment Identity Software Version

A slight variation of the IMEI which also includes the software version of the handset. In essence, this would denote, for example, a particular iOS or Android version.

IMP - Messaging Application Server

A Messaging application server such as an IMP (Instant Messaging Platform) is used to provide support for legacy SMS services, as well as next generation messaging services based on RCS (Rich Communication Services) standards. Key features will include text and multimedia messaging, 1 to 1 chat, group chat delivery, display notifications and multidevice support. In addition, a common message store facility may also feature as a service offered to customers. Messaging sessions will be based on a combination of SIP (Session Initiation Protocol) and MSRP (Message Session Relay Protocol).

IMPI - IMS Private ID

The IMPI within the IMS is the means by which the network identifies the subscription. Typically, the IMPI contains a representation of the subscriber’s IMSI (particularly in VoLTE networks).

IMPU - IMS Public User Identity

The Public User Identity is the means by which a subscriber of an IMS service is identified by other users of the service. For example, in VoLTE, the IMPU typically contains a representation of the subscriber’s telephone number. This could be in a SIP or Tel URI format.

IMS - IP Multimedia Subsystem

The IMS is a service management architecture which was introduced by the 3GPP. Designed to operate using SIP signalling, the IMS is IP-CAN agnostic. That is, regardless of the IP-CAN that the subscriber is connected to, that subscriber should still be able to access their services using SIP signalling directed towards the IMS. The IMS does not provide services itself, rather, it manages requests for services between the subscriber and the AS that provides the service. Core network entities associated with the IMS include the CSCF and HSS.

IMS SCC - Service Centralization and Continuity

IMS SCC includes the IMS Centralized Services and IMS Service Continuity Specifications. IMS SCC would be used in support of SR-VCC (Single Radio Voice Call Continuity), which allows a subscriber conducting a VoLTE call to handover to the 2G/3G network without the call dropping.

IMS-ALG - IMS Application Level Gateway

In the 3GPP IMS (IP Multimedia Subsystem) architecture, the IM-ALG is a DPI (Deep Packet Inspection) device which ensures that addressing contained within SIP signalling is removed if required or altered in order to support NAT traversal. Additionally, the IM-ALG will also monitor SIP signalling in order to detect malicious attack. The IM-ALG is a functional entity of the IBCF (Interconnection Border Control Function).

IMS-MGW - IMS Media Gateway

In the 3GPP IMS (IP Multimedia Subsystem) architecture, the IMS-MGW operates in conjunction with the MGCF (Media Gateway Control Function) in order to support interworking between IP based transport networks and the circuit switched domain. The IMS-MGW will translate media arriving within a TDM based timeslot to an RTP (Real time Transport Protocol) stream or vice versa.

IMS-SSF - IMS – Service Switching Function

The IMS-SSF acts as a gateway between the SIP/Diameter based IMS and the CAP (CAMEL Application Part) based CAMEL (Customized Application for Mobile network Enhanced Logic) application servers. In this role, the IMS-SSF ensures that where appropriate, SIP/Diameter messages are translated to the corresponding CAP message and vice versa.

IMSI - International Mobile Subscriber Identity

The International Mobile Subscriber Identity is a unique identifier allocated to each mobile subscriber in a GSM, UMTS, LTE and 5G network. It consists of a MCC (Mobile Country Code), a MNC (Mobile Network Code) and a MSIN (Mobile Subscriber Identification Number).

IMSI Attach

The term used mainly to identify the procedure when the mobile registers after being switched on.

IMT2000 - International Mobile Telephony 2000

IMT2000 is a vision for a single global standard for wireless networks proposed by the ITU (International Telecommunications Union). It is often perceived as a global 3G (Third generation) system.

IMUN - International Mobile User Number

The International Mobile User Number is a number allocated to a UMTS user.

IN - Intelligent Network

An Intelligent Network is a network in which the intelligence is centralized and separated from the switching function. IN systems provide enhanced services e.g. a VPN (Virtual Private Network).

In Band Signalling

In band signalling utilizes part of the data transmission to carry other control information such as signalling.

INAP - Intelligent Network Application Part

A protocol offering real time communication between IN (Intelligent Network) elements.

Infrared

Electromagnetic waves whose frequency range is above that of microwaves, but below that of the visible spectrum. These electromagnetic frequencies are often used for communication between devices such as notebook computers, printers and mobile phones etc.

INMARSAT - International Maritime Satellite Organization

The International Maritime Satellite organization was set up originally to provide ship to shore communications but was later expanded to include aircraft and general telecommunications.

Inquiry

The inquiry procedure enables a Bluetooth unit to discover which units are in range. The Bluetooth units that see this inquiry may send a response to the inquiring Bluetooth unit. This contains information about the Bluetooth unit itself and its Bluetooth Host.

Insured Burst

Within an ATM (Asynchronous Transfer Mode) network, the largest burst of data above the insured rate that temporarily is allowed on a PVC (Permanent Virtual Circuit) and not tagged by the traffic policing function for dropping in the case of network congestion. The insured burst is specified in bytes or cells.

Insured Traffic

Traffic within the insured rate specified for an ATM (Asynchronous Transfer Mode) PVC (Permanent Virtual Circuit). This traffic should not be dropped by the network under normal network conditions.

Integrated Circuit

A circuit which is constructed as an assembly of electronic elements in a single structure.

Integrity

In the context of security, Integrity is the avoidance of unauthorised modification of information.

INTELSAT - International Telecommunication Satellite Organization

INTELSAT was set up in 1964 to develop a global satellite communication system.

Inter

In relation to mobile networks, a term usually associated with handovers. An example being the GSM system, a handover from one BTS (Base Transceiver Station) to another BTS is identified as a inter BTS handover, however it can also be called an intra BSC (Base Station Controller) handover (assuming that both BTS are on the same BSC).

Interactive service

A service which provides the means for bi-directional exchange of information between users. Interactive services are divided into three classes of services: conversational services, messaging services and retrieval services.

Interconnection

The physical and logical linking of telecommunication networks used by the same or different organizations in order to allow communication.

Interface

An Interface may be defined by a set of technical characteristics describing the point of connection between two telecommunication entities. For example, the connection between a telecommunication network and the customer’s apparatus.

Interference

Interference can best be described as the effect of unwanted signals or noise on a wanted signal. Co-channel interference is caused by unwanted signals sharing the same frequency as the wanted signal and Adjacent Channel Interference is caused by signals on neighbouring channels.

Interleaving

The process by which a stream of bits or symbols from a PDU (Protocol Data Unit) or SDU (Service Data Unit) may be spread in a specific order with bits or symbols from other PDU or SDU. This technique is often used to reduce the effect of a burst of errors on a radio transmission link.

Internet Telephony

The generic term used to describe various approaches to running voice telephony over IP.

InterNIC

The InterNIC serves the Internet community by supplying documentation and a registration service for Internet domain names.

Intra

A term usually associated with handovers. An example being the GSM system, a handover from one BTS (Base Transceiver Station) to another BTS could be identified as an intra BSC (Base Station Controller) handover, however this assumes that both BTS are connected to the same BSC.

Intra Base Station Frame Handler

Intra Base Station Frame Handler The Intra-Base Station Frame Handler exchanges backhaul frames with channel elements involved in an Intra Base Station Soft Handoff.

Intra PLMN handover

Handover within the same network, i.e. having the same MCC-MNC regardless of radio access system. Note: this includes the case of UMTS to GSM handover where MCC-MNC are the same in both cases.

Intra-Cell Handover

A handover within one sector or between different sectors of the same cell is termed an Intra-Cell Handover. These do not require network connections to be altered.

Intranet

Intranet An Intranet is a private network operating the same internet protocols as the Internet but is isolated from the Internet itself. The two networks may be connected but this is usually done through a NAT (Network Address Translator) server and firewall.

IntServ - Integrated Services

The Internet Integrated Services framework provides the ability for applications to choose defined QoS (Quality of Service) for their data. To support this requirement routers along the path followed by an application’s data packets must implement mechanisms to control the QoS offered to those packets. Also a way to communicate the application’s requirements to the routers along the path must also be provided. RSVP (Resource Reservation Protocol) has been defined to fulfil this task.

IOI - Inter Operator Identifier

The IOI is a globally unique identifier to share between operator networks/service providers/content providers to correlate billing information generated within the IMS (IP Multimedia Subsystem).

IoT - Internet of Things

The Internet of Things is best described as the interconnection of billions of devices, often in everyday objects, which will send and receive data. The term is often associated with key verticals such as Automotive, Utilities and Healthcare enabling smart and efficient services to be supported. Examples from these verticals may include, fleet tracking, smart meters and remote health monitoring.

IoTivity

IoTivity is an open source project developing a standard specification and certification programme to enable IoT (Internet of Things) devices to communicate with each other.

IOV - Input Offset Value

The IOV (Input Offset Value) is used in the GPRS ciphering process and consists of a 32bit value generated by the SGSN.

IP - Internet Protocol

IP is a widely used network layer technology, providing transport services to a huge array of network traffic around the globe. Mobile service providers use IP extensively, both in the core and radio access network in order to carry signalling and user plane traffic. For instance, LTE (Long Term Evolution) is based on IP transport on an end to end basis. IP will provide a variety of services to higher layer protocols, including network level addressing to ensure end to end delivery, QoS packet marking, payload identification, protection against unroutable packets and packet fragmentation (although this is rarely used).There are 2 versions of IP currently in existence: IPv4 and IPv6. IPv4 has seen considerable deployment to date, but is limited in terms of the number of unique IP addresses it has available. Conversely, although IPv6 has seen a lower volume of deployment, its addressing capacity is significantly greater.

IP Address - IP Address (IPv4)

IP v4 utilizes a 32bit address which is assigned to hosts. An address is written as 4 octets separated by periods and may range from 0.0.0.0 through to 255.255.255.255. Each address consists of a network number, an optional subnetwork number and a host number. The network portion of the address is used for routing, and the host number is used to address an individual host within the network or subnetwork. Across the Internet, IPv4 addresses are organized using CIDR (Classless Inter Domain Routing).

IP Datagram

An IP Datagram can be defined as the fundamental unit of information which is passed across the Internet. It contains header information such as the source and destination addresses along with the payload data.

IP Flood

This is a class of DoS (Denial of Service) attack whereby the system is flooded with information using up all available bandwidth and so preventing legitimate users from access.

IP Multicast

IP Multicasting allows IP traffic to be distributed from one source to a number of destinations or from many sources to many destinations. This technique is efficient when sending the same information to many hosts, such as a TV service that distributes content as a payload of IP (termed IPTV). Multicasting employs Multicast Groups which hosts will join (using IGMP ) if they are interested in the content being delivered to that multicast group. As such, part of the IPv4 address space has been reserved for multicast group identification. Multicast data for a particular group will be sent to the multicast address of that group, with the routing network responsible for duplicating multicast content as necessary in order to deliver a copy of the packet to all interested parties.

IP Telephony

The transmission of voice and fax phone calls over data networks utilizing IP (Internet Protocol) as the transport mechanism. IP telephony could be carried out across the Internet, private enterprise LAN or a telecoms service provider’s WAN.

IP-CAN - IP Connectivity Access Network

In the 3GPP IMS (IP Multimedia Subsystem) architecture, the IP-CAN is the term given to the access network which provides IP connectivity to the IMS subscriber. Examples include GPRS, LTE and WiFi.

IP-SM-GW - IP Short Message Gateway

The IP Short Message Gateway is an IMS Application Server which handles SIP based messaging services for IMS subscribers. In addition, the IP-SM-GW will interact with the legacy SMSC using MAP signalling in order to allow IMS to SMS conversion and distribution.

IPDR - Internet Protocol Detail Record

The IPDR has been defined in terms of the notation, syntax, encoding, and transport specified to achieve maximum interoperability between service elements, such as the CGF , and business support systems. Consequently, the billing information generated externally can be interpreted by the network and the appropriate invoice can be raised with the customer.

IPLMN - Interrogating Public Land Mobile Network

This term is related to CAMEL operation and defines the location of the GMSC that has triggered interaction with the CSE. The IPLMN will normally be the Home PLMN , unless SOR is being supported.

IPRAN - IP Radio Access Network

IPRAN is a general term used to describe a Radio Access Network (2G, 3G or 4G) which uses IP as a transport layer technology. IPRAN replaces older TDM based transport technologies, which in turn allows the service provider to benefit from OPEX reduction.

IPS - Intrusion Prevention System

IPS is a network security tool which is designed to detect and mitigate against malicious attack. IPS devices monitor the network for irregularities such as malware signatures, changes in average traffic volume or access failures. Once positively identified as an attack, IPS will work with other network elements such as routers in order to prevent or reduce the effectiveness of the attack.

IPSec - IP Security

IPsec provides security within IP transport networks at the individual packet level. Packets which are IPsec protected can be integrity checked, authenticated and encrypted, depending on the level of protection required. Two versions of IPsec exist, AH (Authentication Header) and ESP (Encapsulating Security Payload), the difference being that where both versions support integrity and authentication, ESP also supports encryption. When IPsec is used between two network nodes, a Security Association must be established between them. The Security Association will have a unique SPI (Security Parameters Index) which will be used to determine exactly how the traffic traversing the Security Association is protected.

IPTV - Internet Protocol Television

IPTV describes the notion of delivering TV services via an IP distribution network, as opposed to the more traditional terrestrial broadcast network. IPTV, along with voice and broadband, forms a Triple Play service, which is being offered by many service providers around the globe. Both unicast and multicast techniques are used in IPTV architectures, with the former in support of video on demand type services and the latter deployed to emulate existing terrestrial services. Unicast services typically use RTSP for control, whereas multicast services use a combination of IP Multicast , IGMP and PIM.

IPv6 - Internet Protocol version 6

IPv6 provides a replacement for IPv4. IPv6 includes support for flow Identity in the packet header, which can be used to identify flows and improve QoS (Quality of Service). However, the primary reason for developing IPv6 was the requirement for IP address space. As such, IPv6 uses 128bits for addressing, as opposed to IPv4 which uses 32bits. This provides a colossal amount of address space. IPv6 was formerly known as IPng (next generation).

IPX - IP Packet eXchange

The IPX is the successor to the earlier GRX, providing QoS aware, secure IP connectivity between the PS networks of different mobile service providers.

IPX-Proxy - Internet Packet eXchange Proxy

IPX proxies are designed to support IP service interworking between service providers and as such, there is not a prescriptive definition of the capabilities a particular IPX Proxy may support. However, examples of IPX proxy functionality include session based accounting, support for multilateral roaming agreements, security, media conversion, signalling conversion and Diameter routing.

IrDA - Infrared Data Association

The Infrared Data Association is a non profit making organization established in 1993 to develop hardware and software standards for infrared data transmission.

IREG - International Roaming Expert Group

IREG are involved in the standardization of roaming, specifying the benchmark of capabilities that two service providers must support before roaming agreements can be put into place. As part of this, a large variety of trial call and data scenarios must be conducted successfully between the two roaming partners.

Iridium

A global mobile satellite communication system offering telecommunication services across the entire globe. This system consists of 66 satellites operating in the LEO (Low Earth Orbit).

IRSG - Internet Research Steering Group

The Internet Research Steering Group forms part of the IRTF (Internet Research Task Force) and is responsible for setting the priorities and coordinating research activities of the IRTF.

IRTF - Internet Research Task Force

Internet Research Task Force is a group of technical experts that consider Internet related research topics.

IS - IPDR Store

The IS provides persistence in that IPDR records can be stored prior to transmission. The IPDR Transmitter delivers the IPDR, either from the IS, or directly from the IR to the Business Support System.

IS-136 - Interim Standard 136

Interim Standard 136 is often referred to as DAMPS (Digital Advanced Mobile Phone Service). This system uses a TDMA (Time Division Multiple Access) process over the radio interface which is similar to that used in GSM.

IS-41 - Interim Standard 41

Interim Standard 41 is a signaling protocol used in North American cellular telecommunications systems. It deals with the signalling between the MSC (Mobile Switching Centre) and other network elements for the purpose of handovers and roaming etc.

IS-95 - Interim Standard 95

IS-95 – Interim Standard 95 IS-95 is a TIA (Telecommunications Industry Association) standard for North American cellular systems based on CDMA (Code Division Multiple Access) which are found within North America and Asia. IS-95a is often referred to as cdmaOne which is capable of supporting voice and data at 14.4Kbps whereas IS-95b is capable of supporting data rates up to 115Kbps.

ISAKMP - Internet Security Association and Key Management Protocol

ISAKMP (Internet Security Association and Key Management Protocol) forms part of the protocol suite developed to support IKE (Internet Key Exchange) and is used to define the framework in which a SA (Security Association) is negotiated, established and modified between end points. ISAKMP is protocol independent and consequently may be employed with many IKE protocols such as the Oakley key exchange.

ISC - IP multimedia subsystem Service Control interface

The ISC connects the S-CSCF to the Application Server supported either in the 3GPP Home PLMN or a third party network and is based on SIP. The AS may influence the session or service being provided by the S-CSCF across the ISC. In terms of the logic provided by the service environments the ISC will present this in a consistent format to the S-CSCF through a series of SIP methods and responses.

ISDN - Integrated Services Digital Network

An ISDN is an end to end digital network capable of simultaneous transmission of a range of services such as voice, data and video etc. The network is based upon 64Kbps circuits which are capable of carrying voice or signalling.

ISG - Industry Specification Group

ETSI Industry Specification Groups operate alongside traditional standards-making committees within a specific technology area. ETSI ISGs have their own voting rules and determine their own work programs, ultimately with a view to producing specifications to be published by ETSI.

ISI - Inter Symbol Interference

Inter Symbol Interference is the interference between adjacent pulses of a transmitted code.

ISIM - IMS Subscriber Identity Module

IMS (IP Multimedia Subsystem) subscribers may be issued with an ISIM for the operator or carrier supporting the IMS service. This is similar in nature to the SIM (Subscriber Identity Module) used in GSM and GPRS and the USIM (Universal SIM) employed in UMTS. It holds information regarding a user’s subscription level as well as authentication, security information and their IMS private identity held in the form of a NAI (Network Access Identifier). It should be noted that if the subscriber does not have an ISIM then the USIM may be employed as the security algorithms held on the USIM are the same as those held on the ISIM. An IMS private identity however will have to be resolved from the user’s IMSI (International Mobile Subscriber Identity).

ISM - Industrial, Scientific and Medical

The term ISM is often associated with equipment or applications used with the Industrial, Scientific or Medical environments.

ISMP - Inter System Mobility Policy

In WiFi offload, this defines the preferred access network type if the mobile is unable to connect to both E-UTRAN and Wi-Fi simultaneously.

ISO - International Standards Organization

The International Standards Organization is responsible for a wide range of standards, including those relevant to networking. The ISO developed the OSI (Open System Interconnection) reference model which is a popular networking reference tool.

ISOC - Internet Society

The Internet Society is an international nonprofit making organization that coordinates the evolution and use of the Internet. In addition, ISOC delegates authority to other groups related to the Internet, such as the IAB (Internet Architecture Board).

Isochronous user channel

An Isochronous user channel is used for time bounded information. An example would be compressed audio.

ISP - Internet Service Provider

An Internet Service Provider is a company that provides Internet access to other companies and individuals.

ISRP - Inter System Routing Policy

In a WiFi Offload scenario, if the device is IFOM capable, this policy (supplied to the mobile by the ANDSF) tells the mobile which IP traffic flows should be sent over which access networks.

ISUP - ISDN User Part

ISDN User Part is part of the SS7 (Signalling System No.7) protocol layer and used in the setting up management and release of trunks that carry voice and data between calling and called parties.

IT - Information Technology

Information Technology generally refers to industries using computers and their associated software.

ITS - Intelligent Transportation System

ITS technologies are designed to provide advancements in transport safety and mobility, with a view to boosting economic productivity. They achieve this through the integration of advanced communication technologies into both vehicles and transportation infrastructure.

ITU - International Telecommunications Union

The International Telecommunication Union was established by the United Nations in order to determine a set international telecommunications standards and to allocate radio frequencies for specific uses.

ITU-R - International Telecommunications Union-Radio communication Standardization Sector

The ITU-R is an international body that develops worldwide standards for radio communications technologies.

ITU-T - International Telecommunications Union-Telecommunication Standardization Sector

The ITU-T is an international body that develops worldwide standards for telecommunications technologies. These standards are grouped together in series which are prefixed with a letter indicating the general subject and a number specifying the particular standard. The ITU-T was formally known as the CCITT (Consultative Committee for International Telegraphy and Telephony).

ITU-T Series A

The series of standards dealing with the organization of the work of the ITU-T.

ITU-T Series B

The series of standards dealing with definitions, symbols and classifications.

ITU-T Series C

The series of standards dealing with general telecommunications statistics.

ITU-T Series D

The series of standards dealing with general tariff principles.

ITU-T Series E

The series of standards dealing with the overall network operation, telephone service, service operation and human factors.

ITU-T Series F

The series of standards dealing with the telecommunications services other than those of the telephone.

ITU-T Series G

The series of standards dealing with transmission systems, media, digital systems and networks.

ITU-T Series H

The series of standards dealing with line transmission of non telephone signals.

ITU-T Series I

The series of standards dealing with the ISDN (Integrated Services Digital Network).

ITU-T Series J

The series of standards dealing with the transmission of sound, programme and television signals.

ITU-T Series K

The series of standards dealing with protection against interference.

ITU-T Series L

The series of standards dealing with the construction, installation and protection of cable and other elements of outside plant.

ITU-T Series M

The series of standards dealing with the maintenance of transmission systems, telephone circuits, telegraphy and facsimile.

ITU-T Series N

The series of standards dealing with the maintenance of international sound programme and television transmission circuits.

ITU-T Series O

The series of standards dealing with the specifications of measuring equipment.

ITU-T Series P

The series of standards dealing with telephone transmission quality, telephone installations and local line networks.

ITU-T Series Q

The series of standards dealing with switching and signalling.

ITU-T Series R

The series of standards dealing with telegraph transmission.

ITU-T Series S

The series of standards dealing with telegraph services and terminal equipment.

ITU-T Series T

The series of standards dealing with the terminal characteristics and higher layer protocols for telematics.

ITU-T Series U

The series of standards dealing with telegraph switching.

ITU-T Series V

The series of standards dealing with data communication over a telephone network.

ITU-T Series X

The series of standards dealing with data networks and open system communication.

ITU-T Series Z

The series of standards dealing with programming languages.

Iu Interface

Iu Interface This is the interface which links the RNC (Radio Network Controller) with either a 3G MSC (3G Mobile Switching Centre) or a 3G SGSN (3G Serving GPRS Support Node).

Iu Protocol

Iu Protocol The Iu Protocol defines the structure of user plane on the Iu Interface. The payload of the frame is specified as a certain PDU (Protocol Data Unit) type, depending on the information being transported. These include type 0, type 1 and type 14.

Iu UP - Iu User Plane protocol

IuUP protocol is used to carry user plane data across the Iu interface which is associated with a RAB (Radio Access Bearer). Consequently, if several RABs are associated with a particular mobile, each of these RABs will require a separate instance of the IuUP protocol. The IuUP protocol can be found on either the IuCS or IuPS interface.

Iu-CS Interface – Circuit Switched - Iu-CS Interface (Circuit Switched)

Iu-CS Interface (Circuit Switched) This is the interface in UMTS which links the RNC (Radio Network Controller) with a 3G MSC (3G Mobile Switching Centre).

Iu-PS Interface – Packet Switched - Iu-PS Interface (Packet Switched)

Iu-PS Interface (Packet Switched) This is the interface in UMTS which links the RNC (Radio Network Controller) with a 3G SGSN (3G Serving GPRS Support Node).

Iub Interface

Iub Interface This interface is located on a UMTS network and is found between the RNC (Radio Network Controller) and the Node B.

Iuh Interface

The Iuh Interface spans the link between the HNB and the HNB-GW. As such, it supports the broadband IP connection which links the Femto Cell to the service provider’s core network.

Iur Interface

Iur Interface This Interface is located on a UMTS network and is found between two RNC (Radio Network Controller).

IV - Initialization Vector

An Initialization Vector is a block of bits that is required to allow a stream cipher or a block cipher to be executed in any of several streaming modes of operation to produce a unique stream independent from other streams produced by the same encryption key.

IVR - Interactive Voice Recognition

IVR, also termed Interactive Voice Response, is an automated system which allows key spoken words to be detected and interpreted in order to invoke a particular response. Typical examples of IVR are on automated telephony systems which detect simple statements and direct the calling party accordingly. More sophisticated systems allow the calling party to speak entire sentences, constantly monitoring for key phrases to facilitate correct interpretation.

IVR - Interactive Voice Response

The systems that provide information in the form of recorded messages over telephone lines in response to user input in the form of spoken words or, more commonly, DTMF (Dual Tone Multiple Frequency) signalling.

IWF - Interworking Function

The Interworking Function is used to provide circuit switched data services when connecting a cellular network to a PSTN. It is comprised of rate adapters, modems and fax adapters.

IXP - Internet Exchange Points

An IXP allows ISP (Internet Service Providers)to extend their network by exchanging routing information and traffic with other ISPs. The ISP buys a connection to the exchange point and locates a router at the physical location of the LAN that forms the IXP. An IXP may therefore be defined as: A physical network infrastructure (layer 2), operated by a single entity to facilitate the exchange of Internet traffic between ISPs. The number of ISPs connected should be at least three and there must be a clear and open policy for others to join.

J-Carrier

The Japanese version of the E-Carrier Hierarchy in Europe or T-Carrier Hierarchy in North America. J-1 1.544Mbps J-2 6.312Mbps J-3 32.064Mbps J-4 97.728Mbps J-5 397.000Mbps

Jamming

Jamming is the deliberate introduction of interference to a signal by generating another signal at greater power and close to the transmitted frequency of the first signal.

JANET - Joint Academic Network

The Joint Academic Network is a communication backbone linking UK education and research establishments.

JAVA

JAVA is an object oriented programming language developed at Sun Microsystems. The Java language is used extensively on the WWW (World Wide Web).

Jitter

Jitter can be described as small or random variations in time or phase of a transmitted signal which can result in errors or loss of synchronization.

JPEG - Joint Photographic Experts Group

Joint Photographic Expert Group defined a graphic file format that was adopted as a standard by the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) and the ISO (International Standards Organization). JPEG is often used to compress still images.

Justification

Justification is the method employed to change the rate of a transmitted signal to allow it to match with a system having a different rate.

JVM - JAVA Virtual Machine

JAVA Virtual Machine is an operating system which allows it to run software written in the Java language and provides the universal portability of the JAVA code. It interprets the JAVA byte code and compiles binary code suitable for the underlying operation system.

k - Window Size

The Window Size is used by a receiving device to specify the amount of data it is able to receive. This prevents the transmitting device from sending data which will only be discarded.

K- Key

Long term secret key shared between the USIM and the AuC (Authentication Centre).

Ka Band

Electromagnetic spectrum in the 12GHz to 30GHz frequency range.

KASME - Key Access Security Management Entries

This is a key derived by the UE and the HSS (Home Subscriber Server) from CK and IK during an AKA run. KASME also depends on the PLMN identity ( MCC + MNC ). The key KASME is transferred from the HSS to the ASME (Access Security Management Entity), i.e. MME, as part of an EPS specific authentication vector response.

kbit/s - kilobit / Second

kbps is a measurement of data-rate and is equal to 1000 bits every second.

kByte/s - kilobyte / Second

kByte/s is a measurement of data-rate and is equal to 1000 bytes every second (Note. 1 byte = 8 bits).

Kc - Ciphering Key

The Ciphering Key is a variable used in the GSM and GPRS cipher process. It is applied to ciphering algorithms from the A5 range to produce a cipher stream. This is modulo 2 added to user data in order to protect it from eavesdropping.

KDF - Key Distribution Function

This is part of the LTE authentication and key distribution process. The 3GPP specifications define how keys and associated parameters are passed between entities.

Key Distribution

Key Distribution is a process that delivers a cryptographic key from the location where it is generated to the locations where it will be employed.

Key Pair

A Key Pair is a set of mathematically related keys, generally one public key and one private key. The public key is freely distributed and used to encrypt data; however, it is only possible to retrieve the original information with knowledge of the private key. The keys are generated in a way that makes it very difficult to derive the private key from knowledge of the public key.

Keys

Keys can be described as symbols used in the encryption of plaintext to ciphertext.

kHz - Kilohertz

kHz is a measure of frequency equal to 1000 cycles per second.

Ki - Authentication Key

Ki is a unique key associated with a GSM subscriber. It applied to the A3 and A8 algorithms along with a random number to generate authentication triplets. These are used by the core network to authenticate GSM users.

Kilostream

A term used to describe the digital transmission circuit operating at 64Kbps.

KSI - Key Set Identifier

This is used in the UMTS Authentication process to enable a mobile to be ciphered without the continual need for reauthentication. The equivalent in a GSM network is the CKSN (Cipher Key Sequence Number).

KSIASME - Key Set Identifier Access

The security parameters for authentication, integrity protection and ciphering are tied together in sets and identified by the Key Set Identifier (KSIASME).

Ku Band

Electromagnetic spectrum in the 10GHz to 12GHz frequency band.

L1 - Layer 1

This is also referred to as the OSI (Open System Interconnection) Physical Layer. It provides the functions for the transparent transmission of a bit stream between data link entities.

L2 - Layer 2

This is also referred to as the OSI (Open Systems Interconnection) Data Link Layer. It provides the means for synchronizing the bit stream flowing to and from the physical layer and for the detection of errors due to transmission problems e.g. noise and interference. An example of a Data Link protocol would be Ethernet operating on a LAN (Local Area Network).

L2CAP - Logical Link Controller and Adaptation Protocol

In Bluetooth, the Logical Link Controller and Adaptation Protocol functions include: higher level protocol multiplexing, conveying of quality of service information and controlling packet segmentation and reassembly.

L2M - Layer 2 Management

The Abis interface is proprietary and as such, implementation is vendor specific.

L2ML - Layer 2 Management Link

L2ML is used for transferring Layer 2 management messages.

L2R BOP - Layer 2 Relay Bit Orientated Protocol

This protocol is utilized within GSM non transparent circuit switched data transfer to modify synchronous data streams which then enables RLP (Radio Link Protocol) to provide a reliable and efficient data transfer mechanism.

L2R COP - Layer 2 Relay Character Orientated Protocol

This protocol is utilized within GSM non transparent circuit switched data transfer to modify asynchronous characters which then enables RLP (Radio Link Protocol) to provide a reliable and efficient data transfer mechanism.

L2TP - Layer Two Tunnelling Protocol

L2TP has been defined using the best features of PPTP (Point to Point Tunnelling Protocol) and L2F (Layer 2 Forwarding). It has the ability to encapsulate PPP frames so they can be sent over IP , X.25, Frame Relay , or ATM (Asynchronous Transfer Mode) networks. When using L2TP on an IP based network, the IP datagram supporting the L2TP payload employs the services of UDP (User Datagram Protocol).

L3 - Layer 3

This is also referred to as the OSI (Open Systems Interconnection) Network Layer. It provides the paths for the transfer of data between systems and across networks. The paths between systems may include switched services, and interconnections of multiple subnetworks on route. An example of a protocol operating at the network layer would be IP (Internet Protocol).

L4 - Layer 4

This is also referred to as the OSI (Open Systems Interconnection) Transport Layer. It provides for the transparent transfer of data between peer session layer entities and ensures that the appropriate quality of service is maintained.

L5 - Layer 5

This is also referred to as the OSI (Open Systems Interconnection) Session Layer. It provides the services to control the communication session between the peer entities. The session protocols will determine such things as two-way simultaneous or two way alternate data transfer.

L6 - Layer 6

This is also referred to as the OSI (Open Systems Interconnection) Presentation Layer. It provides the services used to establish the transfer syntax that will be used to support communication.

L7 - Layer 7

This is also referred to as the OSI (Open Systems Interconnection) Application Layer. This layer can be divided into two different service elements, the ACSE (Application Control Service Element) which is responsible for the establishing the association between communication Application Layers and the ASE (Application Service Elements) which are used to satisfy specific contexts such as File Transfer and Network Management etc.

LA - Location Area

A Location Area is a number of cells (defined by the mobile operator) throughout which a GSM / UMTS mobile will be paged.

LAA - License Assisted Access

LAA is a technique for increasing data rates in LTE which essentially provides LTE service providers and their subscribers with an additional mechanism to utilize unlicensed spectrum. LAA coexists with WiFi and other technologies in the 5GHz unlicensed band.

Label

A Label can be described as a short fixed length value that enables switching devices to determine how the data (packets or cells) should be forwarded.

LAC - Location Area Code

The Location Area Code uniquely identifies a LA (Location Area) within a PLMN (Public Land Mobile Network). It may range from 0 to 65,535.

LADN - Local Area Data Network

LADN is the term used in the 5G specifications to refer to a DN (Data Network) that is only accessible in specific locations.

LAI - Location Area Identity

The Location Area Identity uniquely identifies a LA (Location Area) within any PLMN (Public Land Mobile Network). It is comprised of the MCC (Mobile Country Code), MNC (Mobile Network Code) and the LAC (Location Area Code).

LAN - Local Area Network

A Local Area Network is a network shared by communicating devices, usually on a small geographical area. There are many different types of Local Area Network technologies such as Ethernet , AppleTalk, Token Ring etc.

LANE - Local Area Network Emulation

Local Area Network Emulation allows an ATM (Asynchronous Transfer Mode) network to function as a LAN backbone. The ATM network provides services including multicast and broadcast support as well as address mapping.

LAPB - Link Access Protocol Balanced

Link Access Protocol, Balanced is a Layer 2 protocol used in many control protocol stacks such as X.25. LAPB is a bit oriented protocol derived from HDLC (Higher Level Data Link Control).

LAPD - Link Access Protocol on the D Channel

Link Access Protocol on the D channel is a Layer 2 protocol used on the ISDN D channel. LAPD was derived from the LAPB (Link Access Protocol Balanced) protocol and was designed to satisfy the signalling requirements of ISDN basic access. LAPD is defined in the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) recommendations Q.920 and Q.921.

LAPDm - Link Access Protocol on the Dm Channel

LAPDm is a modified version of LAPD (Link Access Protocol in the D channel), the Data link layer protocol. The modifications make it suitable for transmission across a radio interface. It is used in GSM to support the transport of information between the mobile and the network.

LASER - Light Amplification by Stimulated Emission of Radiation

A device which produces short duration high intensity bursts of optical energy. Semiconductor LASER are often used as light sources in optical network transmission systems.

LAU - Location Area Update

A procedure performed by the mobile to supply the MSC with the Location Area in which the mobile currently resides.

LBA - Local Broadcast Area

The area of a broadcast service, where the service content is the same.

LBI - Linked Bearer Identity

When establishing additional EPS bearers the LBI is used to identify Default EPS Bearer with which the new bearer is associated.

LCAF - Location Client Authorization Function

The Location Client Authorization Function is responsible for providing access and subscription authorization to a client. Specifically, it provides authorization to a LCS (Location Services) client requesting access to the network and authorizes the subscription of a client. LCAF provides authorization to a LCS client requesting location information of a specific mobile.

LCCF - Location Client Control Function

The Location Client Control Function manages the external interface towards LCF (Location Client Function) and identifies the LCS (Location Services) client within the PLMN (Public Land Mobile Network) by requesting client verification and authorization through interaction with the LCAF (Location Client Authorization Function).

LCCTF - Location Client Coordinate Transformation Function

The Location Client Coordinate Transformation Function provides conversion of a location estimate, expressed according to a universal latitude and longitude system, into an estimate expressed according to a local geographic system understood by the LCF (Location Client Function) and known as location information. The local system required for a particular LCF will be either known from subscription information or explicitly indicated by the LCF.

LCD - Liquid Crystal Display

A Liquid Crystal Display is an alphanumeric display comprising of a liquid crystal format sandwiched between two films of glass. The display includes an array of electromagnetic dots. These may be charged or discharged; the current flowing through these points affects the transparency of the crystal adjacent to the dots, so controlling the display.

LCF - Location Client Function

The Location Client Function provides a logical interface between the LCS (Location Services) client and the LCS server. This function is responsible for requesting location information for one or more ME (Mobile Equipment) / MS (Mobile Station) with a specified QoS (Quality of Service) and receiving a response, which contains either location information or a failure indicator.

LCID - Logical Channel Identifier

The Logical Channel ID field identifies the logical channel instance of the corresponding MAC SDU or the type of the corresponding MAC control element or padding.

LCR - Least Cost Routing

A telecommunication system feature in which the network automatically selects the lowest cost transmission path to the destination.

LCS - Location Service

Location services are those provided to clients, giving information. These services can be divided into: Value added services (such as route planning information), Legal and lawful interception services (such as those that might be used as evidence in legal proceedings), Emergency services (these will provide location information for organizations such as police, fire and ambulance service).

LDAP - Lightweight Directory Access Protocol

LDAP defines a standard for defining a hierarchical directory structure, and a standard interface for accessing these directories. LDAP grew from the X.500 standard.

LDP - Label Distribution Protocol

LDP is specifically designed for the distribution of label information through an MPLS domain. It achieves this through Discovery messages, Session messages and Advertisement messages.

LE - Local Exchange

A Local Exchange is the first telephone exchange or switch into which the lines connecting subscribers terminate.

Leaky Feeder

A Leaky Feeder is a special type of coaxial cable which can be used to provide radio coverage inside buildings and tunnels.

LEAP - Lightweight Extensible Authentication Protocol

LEAP is a proprietary wireless LAN (Local Area Network) authentication method developed by Cisco Systems. Important features of LEAP are dynamic WEP (Wired Equivalent Privacy) keys and mutual authentication between a wireless client and a RADIUS (Remote Authentication Dial In User Service) server.

Leased Line

A leased line is a transmission line generally leased from a carrier or operator and is used to link several sites in order to carry private data.

LED - Light Emitting Diode

A Light Emitting Diode is a device which converts electrical energy into light.

LEO - Low Earth Orbit

Satellites which are located between 700km and 1500km are said to be operating in a Low Earth Orbit. These satellites are travelling faster than the earth is rotating and as such are moving relative to the earth. An example of a satellite system operating within a Low Earth Orbit is Iridium.

LER - Label Edge Router

LER is a term used in MPLS to describe a router that resides at the ingress and egress points of an MPLS network, handling both labelled and unlabelled packets.

LFIB - Label Forwarding Information Base

The database held within an MPLS Label Switching Router which contains the next hop to label mappings currently in use.

LI - Length Indicator

The Length Indicator is used to specify the number of octets which make up a given IE (Information Element). They may also be used to mark a specific element within an Information Element or frame.

Li-Fi - Light Fidelity

Developed at Edinburgh University, Li-Fi is a communication technology similar to that of Wi-Fi however it operates within the visual light region of the electromagnetic spectrum and as such has specific benefits in electromagnetic sensitive areas such as hospitals and nuclear power facilities.

Line Code

A Line Code defines equivalences between sets of digits generated in a terminal and the corresponding sequence of symbol elements transmitted over the channel.

Link Budget

The process of considering all factors affecting the signal on a transmission line in order to determine the SNR (Signal to Noise Ratio). This information can then be used to plan the network and determine such factors as output power.

Link Key

The Link Key is a Bluetooth authentication key used to establish a link between devices. Devices that share the link key are identified as bonded.

LIPA - Local IP Access

LIPA is a technology related to LTE femtocells which allows subscribers who are attached to Femto or Pico cells to access devices on their local network without traffic entering the service provider’s network. Essentially, traffic destined to another entity on the local network arrives at the Femtocell and is bounced straight back into the LAN (Local Area Network) for delivery.

LKL - Last Known Location

Used in LCS (Location Services), Last Known Location represents the current location estimate and its associated time stamp for a target mobile stored in the LCS server

LLC - Logical Link Control

LLC provides a highly reliable ciphered logical link. This is achieved by providing a means of checking frame errors and signalling back to the originator for the purpose of retransmission. LLC therefore becomes an important link, especially when a mobile moves from one BSS (Base Station Subsystem) to another. LLC is also independent of the underlying radio interface protocols; a feature which was designed to enable an alternative GPRS radio solution, yet minimize the changes required to the NSS (Network Subsystem).

LLPDU - Logical Link Control Protocol Data Unit

In a GPRS system an LL-PDU is a frame comprising of either, user data, SMS message or GPRS Mobility Management information which has been built by the LLC (Logical Link Control) protocol enabling its reliable transfer between the MS (Mobile Station) and SGSN (Serving GPRS Support Node).

LLS - Lower Layer Split

LLS is a term relating to the functional split option point in RAN deployments where the interconnectivity point between the centralised unit and the distributed units is positioned in the protocol stack from the MAC layer downwards.

LM - Link Manager

The Link Manager function in Bluetooth controls how the Bluetooth piconets and scatternets are established and maintained. It carries out link establishment, authentication, and configuration procedures.

LMA - Local Mobility Anchor

The LMA is part of PMIPv6, functioning as the Home Agent in a PMIPv6 deployment.

LMMF - LMU Mobility Management Function

The LMU Mobility Management Function is responsible for maintaining the operational status of LMU (Location Measurement Unit) and registering each LMU with a SMLC (Serving Mobile Location Centre). Operation of the LMMF is independent of other logical LCS (Location Service) functions and its output is provided to the PRCF (Positioning Radio Coordination Function).

LMP - Link Manager Protocol

The Link Manager Protocol in Bluetooth is used for link set-up, security and control. The signals are interpreted and filtered out by the LM (Link Manager) on the receiving side and are not propagated to higher layers. Link Manager messages have higher priority than user data and therefore shall not be delayed by other traffic.

LMU - Location Measurement Unit

A typical cell site will feature an LMU in order to support network based location services. The LMU is responsible for taking specific radio interface measurements, typically under the control of the SMLC (Serving Mobile Location Centre). Measurements are often in relation to TDOA (Time Difference On Arrival) which, when combined with the measurements taken from three or more other LMUs can be used to triangulate the location of the subscriber.

Load Balancing

Load balancing is the process of distributing traffic over transmission lines so that they carry approximately the same density of traffic.

Local Broadcast Area

The area of a broadcast service, where the service content is the same.

Local Loop

The Local Loop is the term for the system used to connect the subscriber’s equipment or PABX (Private Automatic Branch Exchange) to the LE (Local Exchange) or CE (Central Office). This may also be referred to as the Final or Last Mile.

Logical Channels

A set of Logical Channel types are defined for different kinds of data transfer. Each logical channel type is defined by what type of information is transferred.

Logical OM

Logical OM (Operations and Maintenance) is the signalling associated with the control of logical resources (channels, cells,) owned by the RNC (Radio Network Controller) but physically implemented in the Node B. The RNC controls these logical resources. A number of OM procedures physically implemented in Node B impact on the logical resources and therefore require an information exchange between RNC and Node B. All messages needed to support this information exchange are classified as Logical OM forming an integral part of NBAP (Node B Application Part).

Long Code

Long Code A PN (Pseudorandom Noise) sequence with period 2 42 – 1 that is used for scrambling on the Forward CDMA Channel and spreading on the Reverse CDMA Channel. The long code uniquely identifies a MS (Mobile Station) on both the Reverse Traffic Channel and the Forward Traffic Channel.

Long Code Mask

This is a 42bit binary number that creates the unique identity of the long code.

Loopback

Loopback is a test method in which a signal is sent to the device under test which then returns the signal to the originator for comparison.

LoRa

LoRa is a Long Range Low Power wireless technology developed by the LoRa Alliance and often associated with the IoT (Internet of Things). The radios operate in unlicensed radio spectrum to support communication between remote sensors and their gateways, providing a secure high capacity communication link.

LOS - Line Of Sight

This term is often associated with radio transmission systems indicating there is a clear path between the transmitter and receiver. An example of a communication system that requires a Line Of Sight is a microwave link.

Lossy

A very general term to describe a packet switched network that is prone to loose packets when the traffic levels build up.

Low Pass Filter

A Low Pass Filter is a device which allows all frequencies below a predetermined value to pass through whilst blocking all those above.

LPC - Linear Predictive Coding

Linear Predictive Coding is an encoding technique used to aid in the prediction of the next sample. This technique can be found in many analogue to digital conversion processes.

LPWA - Low Power Wide Area

Often associated with Mobile IoT (Internet of Things), Low Power Wide Area is a generic term for a group of technologies with the following characteristics; long battery life, (10 years +), wide area coverage, low chipset costs and limited data throughput. Technologies under this group include EC-GSM (Extended Coverage GSM), LTE-M (Long Term Evolution – Machine to Machine) and NB-IoT (Narrow Band – Internet of Things).

LR - Location Register

Location Registers are database functions storing information typically used in the routing of signalling information. Typical examples include the HLR (Home Location Register) and VLR (Visitor Location Register) used in GSM.

LRF - Location Retrieval Function

In the 3GPP IMS, the LRF retrieves location information for users that have initiated an emergency session. This location information is provided to the E-CSCF (Emergency CSCF) in order to facilitate routing of the call to a suitable PSAP (Public Safety Answering Point).

LSA - Exclusive Access Cell

A mobile may only camp on this cell if the cell belongs to the LSA (Location Service Area) to which the user has subscribed. Nevertheless, if no other cells are available, the mobile of non-LSA users may originate emergency calls from this cell.

LSA - Licensed Shared Access

Licensed Shared Access relates to radio spectrum usage. It extends the concept of ASA (Authorised Shared Access) to other services. LSA provides a complementary tool for spectrum management.

LSA - Localized Service Area

A Localized Service Area is a network defined group of cells, in which specific access conditions apply. This may correspond to an area in which the Core Network offers specific services. A LSA may be defined within a PLMN or globally. Therefore, a LSA may offer a non-contiguous radio coverage.

LSA Only Access

When LSA (Localized Service Area) only access applies to the user, the mobile can only access cells that belong to the LSAs to which the user has subscribed. Outside the coverage area of the subscribed LSAs, the mobile may camp on other cells and limited services apply.

LSAF - Location Subscriber Authorization Function

The Location Subscriber Authorization Function is responsible for authorizing the provision of a LCS (Location Services) for a particular mobile. Specifically, this function validates that a LCS can be applied to a given subscriber.

LSBcF - Location System Broadcast Function

The Location System Broadcast Function provides a broadcast capability and is only used when broadcast data is required for E-OTD ( E-OTD – Enhanced Observed Time Difference) or AGPS (Assisted Global Positioning System) positioning methods.

LSBF - Location System Billing Function

The Location System Billing Function is responsible for LCS (Location Services) billing activity within the network. This includes charging and billing of both clients and subscribers. Specifically, it collects charging related data and data for accounting between PLMN (Public Land Mobile Network).

LSCF - Location System Control Function

The Location System Control Function is responsible for coordinating location requests. This function manages call-related and non-call-related positioning requests of LCS (Location Services) and allocates network resources for handling them. The LSCF retrieves the MS (Mobile Station) classmark which enables it to determine the positioning method to use.

LSOF - Location System Operation Function

The Location System Operations Function is responsible for the provisioning of data, positioning capabilities, data related to clients and subscription information, validation, fault management and performance management of LCS (Location Services).

LSP - Label Switched Path

LSP is an MPLS term used to describe the virtual circuit between two LER (Label Edge Router).

LSPF - Location Subscriber Privacy Function

The Location Subscriber Privacy function is responsible for performing all privacy related authorizations. For a target mobile, it will authorize the positioning request versus the privacy options of the mobile.

LSR - Label Switching Router

LSR is a term used in MPLS to describe an MPLS node which is capable of forwarding labelled packets.

LSSU - Link Status Signalling Unit

The Link Status Signalling Unit is sent between two SS7 signalling points and serves to indicate the status of the specific link. When a link is determined to have failed the signalling point that detected the error condition is responsible for alerting adjacent signalling points that the link is not available. The LSSU is used to perform this task.

LTE - Line Terminating Equipment

Line Terminating Equipment may also be referred to as Line Terminal Equipment and is the equipment which terminates the transmission line. Examples include a telephone or facsimile machine.

LTE - Long Term Evolution

Standardized in 3GPP Release 8, LTE introduces a network which is based purely on IP as the transport mechanism. That is, all traffic, including voice, will be passed across the E-UTRAN as an IP datagram. Moreover, all of the network nodes within LTE use IP to carry signalling between one another. Termed the EPS (Evolved Packet System), the end to end LTE network is comprised of the E-UTRAN (Evolved – Universal Terrestrial Radio Access Network) and the EPC (Evolved Packet Core).

LTE-A - LTE Advanced

Standardized in 3GPP Release 10, LTE-Advanced introduced enhancements to the LTE Radio interface which allow typical user data rates in the low hundreds of Mbps, with theoretical rates in the downlink as high as 1Gbps. Technologies introduced in order to facilitate this include higher order modulation techniques (128 QAM), Carrier Aggregation (up to 5x20MHz channels hence 100MHz total) and enhanced MIMO (up to 8×8).

LTE-A Pro - LTE Advanced Pro

LTE Advanced Pro is a technology marker for 3GPP technologies developed during the standardization of 3GPP Release 13 and Release 14. Technology enhancements introduced in these specifications include multi carrier aggregation, LAA (License Assisted Access), Massive MIMO, D2D (Device to Device), V2X (Vehicle to Anything), NB-IOT (Narrowband Internet of Things) and LTE for Public safety, amongst many others.

LTE-M - LTE Machine Type Communications

LTE-M is a technology based on existing LTE standards which is specifically designed for MTC. As such, LTE-M features an extended DRX cycle which makes the LTE-M device more energy efficient. Due to the fact that LTE-M is based on LTE, support for LTE-M in the network is not a significant cost undertaking. LTE-M works within a 1.4Mhz LTE channel.

LTE-U - LTE Unlicensed

LTE-U was originally developed by Qualcomm as a mechanism for operating a 4G LTE radio deployment within the 5GHz Unlicensed spectrum band. This technology is designed to augment existing LTE coverage, without using alternative technologies such as Wi-Fi.

LVRB - Local Virtual Resource Block

The E-UTRA uses the concept of VRB (Virtual Resource Block) when allocating resources. It defines two types: LVRB (Local Virtual Resource Block) – this is the same as the PRBs and DVRB (Distributed Virtual Resource Block) – this identifies a distribution of the resources required over a number of PRBs.

M-CSI - Mobility Management – CAMEL Subscription Information

The HLR contains M-CSI so that the CSE (CAMEL Service Environment) may monitor and control MM (Mobility Management) events. It is sent to the VLR during the Location Update and Restore Data procedures or when M-CSI is modified in the HLR.

M-TMSI - M Temporary Mobile Subscriber Identity

The M-Temporary Mobile Subscriber Identity provides for an unambiguous identity of the UE within a particular MME.

M2PA - MTP 2 Peer to Peer Adaptation

M2PA forms part of the Sigtran Architecture along with SUA (SCCP User Adaptation) M3UA (MTP3 User Adaptation) and M2UA (MTP2 User Adaptation). While M2UA provides an MTP3/MTP2 interface boundary M2PA provides functionality for full message handling and network management between SS7 nodes communicating across an IP network. Using this protocol the IP connection between the nodes may be viewed as a fully functional signalling link.

M2UA - MTP2 User Adaptation

MTP2 User Adaptation Layer is used to access MTP2 (Message Transfer Part Level 2) functions using SCTP (Streaming Control Transmission Protocol). A typical scenario would be if an agent in an IP (Internet Protocol) based network needed to send and receive signalling network management messages from a SG (Signalling Gateway).

M3AP - M3 Application Protocol

M3AP is used in support of eMBMS (Evolved Multimedia Broadcast Multicast Services) and is found on the M3 reference point, located between the MME and eNB (specifically the Multicell/Multicast Coordination Entity). The main role of M3AP is the support of MBMS Session Management, ensuring that the MCEs within the eNB are provided with the correct information to enable them to receive an MBMS service from the core network. In turn, the MCE will use information provided in M3AP messages to correctly establish the required radio resources.

M3UA - MTP Level 3 User Adaptation Layer

M3UA enables the transport of SS7 (Signalling System number 7) signalling over IP using the services of SCTP (Stream Control Transmission Protocol). There are various User Adaptation layers available, the choice of which is determined by how much SS7 functionality (in terms of layers) needs to be retained in the IP transport network. Options include SUA (SCCP User Adaptation), M3UA (MTP3 User Adaptation), M2UA (MTP2 User Adaptation) and M2PA (MTP2 Peer to Peer Adaptation).

MA - Multiple Access

The term Multiple Access is used to describe a system where several users can gain access to a common transmission channel. Examples of Multiple Access systems include TDMA (Time Division Multiple Access) used in GSM , CDMA (Code Division Multiple Access) used in UMTS and CSMA/CD (Carrier Sensing Multiple Access/Collision Detection) used by Ethernet.

MAC - Medium Access Control

The MAC protocol layer is present in the mobile and the NB/eNB in order to support the correct multiplexing/demultiplexing of signalling and user plane traffic onto the various transport channels of the air interface.

MAC Address

This is often referred to as a hardware address and uniquely identifies a device within a defined network area such as a LAN (Local Area Network). A common example of a MAC address would be an Ethernet address which will be associated with an Ethernet NIC (Network Interface Card) used by all computers connected on an Ethernet LAN.

MAC-e

The Node B has one MAC-e entity per UE. The MAC-e entity consists of a number of functions, including: E-DCH Scheduling, E-DCH Control, demultiplexing of the MAC-e PDU and HARQ operation.

MAC-e/es

The MAC-es/e at the UE handles the E-DCH specific features and functions, which include: HARQ , Multiplexing and sequence number setting, as well as selection according to the E-RGCH and E-AGCH information received from the UTRAN via Layer 1.

MAC-es

In the SRNC there is one MAC-es entity per UE. Key functions of MAC-es in the SRNC include: – route MAC-es PDU to the correct reordering buffer. – Reordering – this function is responsible for reordering received MAC-es PDU. Each logical channel has its own reordering queue. – Disassembly – this is responsible for disassembly of MAC-es PDU, such that the MAC-d PDU can be delivered to MAC-d. – Macro Diversity Selection – depending on implementation, when an UE is in soft handover there may be one or more reordering queue distribution entities.

MAC-hs

The MAC-hs layer was added to the UMTS Node B as part of HSDPA (High Speed Downlink Packet Access). It controls the H-ARQ functionality of every HSDPA user, distributing the resources between according packet scheduling, as well as dynamically controlling link adaptation.

Macro Cell

Macro Cell A large cell, typically tens of kilometres that is optimized to provide coverage and not capacity.

MAG - Mobile Access Gateway

The MAG is a functional element of a PMIPv6 (Proxy Mobile IP version 6) domain which would reside in the foreign network. When a mobile device enters the foreign network, the MAG is responsible for communicating with the LMA (within the home network) in order to establish a bidirectional communication path between the home and foreign network.

Malware - Malicious Software

Malware describes a wide range of unwanted software that can be present on an infected machine, ranging from viruses, worms and Trojans to spyware and addware.

MAN - Metropolitan Area Network

A Metropolitan Area Network is a network of LAN (Local Area Networks) or computers within a wide geographical area such as a university campus etc.

Manchester Encoding

A digital encoding technique in which each bit period is divided into two halves.

MANO - Management and Orchestration

With respect to NFV (Network Functions Virtualization), MANO provides the ability to instantiate new virtualized nodes, manage existing nodes and also scale up or down resources for a given node. In addition, MANO facilitates the on-boarding of new VNFs (Virtualized Network Functions) into the system, as well as managing the instantiation of new network services. Key elements of MANO include the NFVO (NFV Orchestrator), VNFM (VNF Manager) and VIM (Virtualized Infrastructure Manager).

MAP - Mobile Application Part

MAP – Mobile Application Part A protocol which enables real time communication between nodes in a mobile cellular network. A typical usage of the MAP protocol would be for the transfer of location information from the VLR (Visitor Location Register) to the HLR (Home Location Register).

MAP - Mobile Application Part

MAP – Mobile Application Part A protocol which enables real time communication between nodes in a mobile cellular network. A typical usage of the MAP protocol would be for the transfer of location information from the VLR (Visitor Location Register) to the HLR (Home Location Register).

Mapping

The logical association of one or more parameters in different networks.

MARS

MARS is a symmetric block cipher with a block size of 128bits. It employs a variable key ranging in length from 128bit to 448bit. The algorithm was designed by IBM and was one of the five candidates selected to become the AES (Advanced Encryption Standard).

Massive MIMO

Massive MIMO (Multiple Input Multiple Output) systems are effectively MIMO systems with a large number of antennas. The term Massive MIMO is closely linked to the latest enhancements in radio systems, e.g. 5G.

Master Clock

This is the clock which acts as the prime reference source within a network and from which all other clocks derive their reference.

Master Device

The Master Device is a term used to identify a Bluetooth device that can initiate an action or service on a piconet. The piconet will be synchronized to the clock and hopping sequence from the master device.

MBB - Mobile Broadband

This is a generic term used to describe various wireless high-speed Internet access technologies.

MBMS - Multimedia Broadcast/Multicast Service

The MBMS is a unidirectional point to multipoint bearer service in which data is transmitted from a single source entity to multiple recipients. These services will typically be in the form of streaming video and audio and should not be confused with the Cell Broadcast Service.

MBR - Maximum Bit Rate

The MBR is the variable set in a traffic scheduler such as an LTE eNB. This value determines the highest bit rate that may be allowed by a device being served by the access network.

MBS - Maximum Burst Size

A term used in ATM (Asynchronous Transfer Mode) to specify the maximum number of cells which can be transmitted at the contracted PCR (Peak Cell Rate).

MBSFN - MBMS over a Single Frequency Network

MBSFN, as the title suggests, describes the delivery of MBMS (Multimedia Broadcast Multicast Services) over a radio network which is synchronised in order to minimise interference. The technique allows a group of cells to transmit the same multicast content utilizing the same radio sub-carriers, which essentially means a group of cells all appear as one large cell since the content transmitted from each individual cell is identical (and synchronized).

MC - Mission Critical

The quality or characteristic of a communication activity, application, service or device, that requires low setup and transfer latency, high availability and reliability, the ability to handle large numbers of users and devices, strong security and priority handling.

MCC - Mobile Country Code

The Mobile Country Code is a three digit number uniquely identifying a given country. It is utilized within numerous identities across 3GPP mobile networks, including the IMSI (International Mobile Subscriber Identity), LAI (Location Area Identity) and GUTI (Globally Unique Temporary ID).

MCData - Mission Critical Data

As part of Mission Critical Services, MCData service provides a number of generic capabilities such as messaging, file distribution and data streaming. In addition, it provides specific services such as conversation management, database enquiries, Internet and intranet access, and also robot control.

MCE - Multicell/Multicast Coordination Entity

The MCE forms part of the overall MBMS (Multimedia Broadcast Multicast Service) and is responsible for the coordination of radio resources at the cell site. As such, an MBMS capable eNB (evolved Node B) must include an MCE as part of its functionality, or be in communication with a standalone MCE. Responsibilities of the MCE include admission control and allocation of radio resources related to eMBMS services.

MCEF - Mobile Station Memory Capacity Exceeded Flag

A part of the MWI (Message Waiting Indication) to be stored in the HLR (Home Location Register). MCEF indicates if the address list of MWD (Message Waiting Data) contains one or more entries where SMS delivery has failed because the memory capacity of the subscriber’s SIM (Subscriber Identity Module) or USIM (UMTS Subscriber Identity Module) is exceeded.

MCG - Master Cell Group

With respect to Dual Connectivity, MCG is the term given to the group of serving cells associated with the Master RAN node.

MCID - Malicious Communication Identification

MCID is a supplementary service which allows the service provider to trace the identity information of the source of an incoming communication on request of the destination user.

Mcps - Megachips per Second

Megachips per second (10 6 chips per second).

MCPTT - Mission Critical Push To Talk

The collection of applications, services, and enabling capabilities required to provide Mission Critical Push To Talk for a Mission Critical organization.

MCPTT Service - Mission Critical Push To Talk Service

A push to talk communication service supporting applications for Mission Critical organizations and also mission critical applications for other business and organizations with faster setup times, high availability, reliability and priortiy handling.

MCS - Modulation Coding Scheme

Modulation and Coding Scheme is a term used within EGPRS (Enhanced GPRS) to specify which of the nine different modulation and coding schemes is being applied. The modulation schemes can be either GMSK (Gaussian Minimum Shift Keying) or 8PSK (8 Phase Shift Keying).

MCVideo - Mission Critical Video

As part of Mission Critical Services, MCVideo service provides users with the ability to capture and stream video securely. In support of Mission Critical and Public Safety functionality group sessions, end-to-end confidentiality, emergency type communications and low latency performance are provided.

MD - Mediation Device

A Mediation Device allows two differing devices to interconnect through it by offering such services as protocol conversion and mediation.

MD5 - Message Digest 5

MD5 (Message Digest 5) was developed by RSA Security Inc to provide a strong one way hashing function. The algorithm generates a fixed length (128bit) digest from a message of any length, that can be appended to prove data integrity. While viewed to be a strong algorithm new digests such as SHA-1 which generate a 160bit digest are now thought to be more robust than MD5.

MDF - Main Distribution Frame

A Main Distribution Frame is often found at the local exchange and is used to terminate the copper cables running from the customers site. The frame allows these cables to be cross connected to other equipment such as a concentrator or switch.

ME - Mobile Equipment (Generic)

Mobile Equipment is the hardware element of a mobile station and comprises of keyboard, screen, radio, circuit boards and processors etc.

MEC - Multi access Edge Computing

MEC is a means by which compute/storage resources can be positioned closer to the subscriber’s point of attachment to the network. So, in the case of 5G for example, it’s possible that the UPF (User Plane Function) is situated at the RAN site in order to provide access to MEC resources that are in close proximity to the subscriber. Use cases for MEC are varied but include content caching, support for AR/VR and DNS caching.

MediaFLO - Media Forward Link Only

MediaFLO was a system designed by Qualcomm specifically for the transmission of digital TV to a mobile user. Content streams were delivered to a NOC (Network Operations Centre) via a satellite or IP feed in an MPEG-2 format. The encoded data was then delivered to networks of FLO ( Forward Link Only) transmitters using multiplexed links. At the FLO transmitters, the upper layer data streams (H.264 video, MPEG-4 Advanced Audio Coding etc.) are multiplexed into one logical channel and transmitted, using a combination of TDM (Time Division Multiplexing)and OFDM. MediaFLO used multicasting and also required a 3G network for provision of interactive services. The service was discontinued in 2011.

MEF - Metro Ethernet Forum

The MEF was the standards body behind the introduction of Carrier Ethernet. Since its introduction, the MEF have continued to update and refine the technology.

MEGACO - Media Gateway Control

This VoIP (Voice over IP) term is also known as the ITU-T (International Telecommunications Union – Telecommunications Standardization Sector) H.248 standard and represents a collaboration between the ITU-T and the IETF (Internet Engineering Task Force). MEGACO is a media gateway control protocol used to create, modify and delete media streams across a media gateway in addition to negotiating the media formats to be used. Since its initial standardization, the IETF have relinquished any further development responsibilities to the ITU.

Megastream

A British Telecommunications term to describe an E1 bearer comprising of 32 (64Kbps) channels.

MEO - Medium Earth Orbit

Satellites which are located between 10,000km and 15,000km are said to be operating in a Medium Earth Orbit. These satellites are travelling faster than the earth is rotating and as such are moving relative to the earth.

MER - Message Error Rate

The number of paging messages in error on the Paging Channel or Forward Common Control Channel divided by the total number of pages.

Message

A generic term for an SDU (Signalling Data Unit) which is transferred between two network elements.

Message Switching

A transmission system which uses an intermediate point for the storage and forwarding of messages between two communicating systems.

MExE - Mobile Execution Environment

The Mobile Execution Environment provides a standardized execution environment in an MS (Mobile Station), and an ability to negotiate its supported capabilities with a MExE service provider, allowing applications to be developed independently of any MS platform. The MS can then be targeted at a range of implementations for MExE from small devices with low bandwidth, limited displays, low processor speeds, limited memory, etc., to sophisticated PDA (Personal Digital Organizer) type devices with a complete MExE execution environment.

MFBR - Maximum Flow Bit Rate

The MFBR is used in 5G to limit the bit rate that a GBR (Guaranteed Bit Rate) QoS Flow will provide. Excess traffic will be discarded by a rate shaping function.

MG-CSI - Mobility Management for GPRS – CAMEL Subscription Information

The HLR contains MG-CSI so that the CSE (CAMEL Service Environment) may monitor and control MM (Mobility Management) events. It is sent to the SGSN during the Attach Update Location and Restore Data procedures or when MG-CSI is modified in the HLR.

MGC - Media Gateway Controller

A functional entity within a network that supports the call control function for distributed switching systems.

MGCF - Media Gateway Control Function

The MGCF facilitates call control, interfacing the PS domain to the CS domain when interworking between the IMS and PSTN is required. From a control perspective, the MGCF has the same responsibilities as a regular telephony exchange, with the addition of protocol conversion in order to switch between SIP (Session Initiation Protocol) and ISUP (ISDN User Part) signalling. An MGCF will control one or more IMS-MGW (IMS Media Gateways) and will be used in conjunction with a BGCF (Breakout Gateway Control Function) for calls breaking out to the PSTN/PLMN.

MGCP - Media Gateway Control Protocol

A command based protocol for the delivery of information between MGC (Media Gateway Controller) and MGW (Media Gateway). Typical protocols include MEGACO / H.248.

MgNB - Master gNB

A device operating in 5G DC (Dual Connectivity) or NE-DC (NR – E-UTRA Dual Connectivity) identifies the Master RAN node as the “Master gNB”. As such, it connects to the 5GC via the N2/N3 interfaces, as well as to the Secondary RAN node via the Xn interface.

MGW - Media Gateway

The MGW handles the media plane (voice) in a distributed switch (a Soft Switch). Controlled by an MSC-S (Mobile services Switching Centre Server), the MGW will provide CS/PS media stream termination, transcoding and conversion services.

MHz - MegaHertz

MHz is a measure of frequency equal to one million cycles per second.

MIB - Management Information Base

The Management Information Base is a collection of managed objects defined by their attributes and visible to the network management system.

MIB - Master Information Block

The UTRA/E-UTRA both send key information in the Master Information Block. In LTE, this RRC message includes the Bandwidth, PHICH Configuration and System Frame Number.

MICO - Mobile Initiated Connection Only

MICO is a mode of operation for 5G devices. When a MICO activated device is in an Idle state, the 5G network will consider the device to be unreachable. The device will only receive MT (Mobile Terminated) data when it transitions to a Connected state. This transition to Connected whilst in MICO mode is always triggered by the mobile; the mobile will not be paged whilst in MICO mode.

Microcells

Microcells are relatively small cells within a cellular network. They enable greater frequency reuse by allowing radio frequency propagation to be confined to a small local area.

Microwave

The term Microwave describes electromagnetic radiation with the frequency range of 890MHz to 30GHz. Microwave links are commonly found in telecommunication networks as they provide a relatively quick and cheap method of connecting points within the network. However, it should be stated that microwaves travel in straight lines and as such, it is necessary to have a clear line of site between transmitter and receiver. Microwave frequencies are also often used for the radio link between earth and satellites in orbit.

MIFR - Master International Frequency Register

The MIFR is an ITU register that is used to manage the assignment of frequencies with their particulars in accordance with Article 11 of the ITU Radio Regulations (RR).

MILNET - Military Network

MILNET along with the DARPANET (Defense Advanced Research Project Agency Network) was formed in 1983 as the successor to the ARPANET (Advanced Research Projects Agency Network) and was used for non classified United States of America military communications. It is also often perceived as being an early element of the Internet.

MIM - Man In the Middle

A generic term for network attack in which a communication path is intercepted by a Man in the Middle, typically for malicious purposes. The Man in the Middle may intercept and change the data, or may copy the data for subsequent cryptanalysis.

MIME - Multipurpose Internet Mail Extension

Multipurpose Internet Mail Extension is a technical standard for the transmission of non text data (or data that cannot be represented in plain ASCII code). It is often used in email to deal with foreign language text as well as for audio and video data.

MIMO - Multiple Input Multiple Output

The ever increasing requirement for higher data rates and improved QoS across wireless links has generated the need to improve the spectral efficiency and reliability of radio communication. One way to achieve this is through the use of multiple antennas at each end of the transmission link. This technique is known as MIMO.

MIN - Mobile Identification Number

The Mobile Identification Number is a 10 digit number assigned to the MS (Mobile Station) which is represented by 32bits. This is used on air interface standards published before 1994, with the IMSI (International Mobile Subscriber Identity) being the current identity.

Mini PDU - Mini Protocol Data Unit

A PDU (Protocol Data Unit) that carries a Layer 3 mini message. The total length of a Mini PDU is 48bits and it may not be fragmented.

Mining

This is a term used in relation to Blockchains and refers to the process by which transactions are verified and added to the blockchain.

MIoT - Massive Internet of Things

Enhanced Mobile Broadband is a key part of 3GPP 5G SMARTER (Services and Markets Technology Enablers). The study started in 2015 and looked at potential 5G requirements, which resulted in more than 70 different use cases, grouped into CriC (Critical Communications), MIoT (Massive Internet of Things), eMBB (Enhanced Mobile Broadband) and Network Operation.

MIoT - Mobile Internet of Things

This is a term given to a number of 3GPP defined LPWA (Low Power Wide Area) technologies in the IoT space. These include EC-GSM-IoT, LTE-M and NB-IoT.

MIP - Mean Input Power

Mean Input Power is the total received power measured within a specific bandwidth at the antenna connector.

MIP - Mobile Internet Protocol

The Mobile Internet Protocol provides a set of extensions to the Internet protocol standards defined by the IETF (Internet Engineering Task Force). Its focus is to allow users to register on Foreign networks and connect back to their Home network via a combination of FA (Foreign Agent) and HA (Home Agent).

MM - Mobility Management

MM is a sublayer of the Layer 3 connectivity between the mobile and the core network, providing services which support the mobility of user terminals, as well as location reporting when required. Additional features include providing user identity confidentiality, along with providing connection management services to higher layers.

MM - Multimedia Message

A Multimedia Message is part of the MMSE (Multimedia Message Service Environment) and is capable of carrying such formats as text, speech, still image and video.

MM1 - Multimedia Messaging Reference Point 1

The Multimedia Messaging Reference Point 1 defines the link between MMS (Multimedia Massaging Service) User Agent and the MMS Relay/Server.

MM2 - Multimedia Messaging Reference Point 2

Multimedia Messaging Reference Point 2 defines the link between MMS (Multimedia Massaging Service) Relay and the MMS Server.

MM3 - Multimedia Messaging Reference Point 3

The Multimedia Messaging Reference Point 3 defines the link between MMS Relay/Server and servers of external (legacy) messaging systems that are connected to the service provider’s MMS Relay/Server.

MM4 - Multimedia Messaging Reference Point 4

The Multimedia Messaging Reference Point 4 defines the link between MMS Relay/Server belonging to different MMSE (Multimedia Messaging Service Environment).

MM5 - Multimedia Messaging Reference Point 5

The Multimedia Messaging Reference Point 5 defines the link between the MMS Relay/Server and the HLR (Home Location Registry)

MM6 - Multimedia Messaging Reference Point 6

The Multimedia Messaging Reference Point 6 defines the link between the MMS Relay/Server and MMS User Databases.

MM7 - Multimedia Messaging Reference Point 7

The Multimedia Messaging Reference Point 7 defines the link between the MMS Relay/Server and MMS VAS (Value Added Services) applications.

MMD - Multimedia Domain

3GPP2 have developed the standards for the MMD. The MMD is a CDMA based wireless network which provides 3rd Generation capabilities, all based on IP protocols and network elements. The MMD is based on the 3GPP IMS and as a result has many matching features and entities.

MME - Mobility Management Entity

The MME is responsible for mobility and session management procedures in the EPC. As such, the MME communicates with the mobile via NAS (Non Access Stratum) signalling and communicates with the HSS through Diameter. Key responsibilities include ECM (EPS Connection Management), EMM (EPS Mobility Management), gateway selection, NAS security and handover assistance.

MMEC - Mobility Management Entity Code

The MMEC uniquely identifies an MME within an LTE network.

MMEGI - MME Group ID

When MME Pooling is utilised within an LTE network, the MMEGI identifies which group (pool) the MME is assigned to. The MME’s MMEC will then uniquely identify the MME within the assigned pool.

MMEI - Mobility Management Entity Identifier

The MMEI is constructed from an MMEGI (MME Group ID) and an MMEC (MME Code), where the MMEGI provides the Group Identity of the registered MME within the PLMN.

MMI - Man Machine Interface

This is the interface between the user and the equipment or machine. An example of Man Machine Interface is the keypad and display of a mobile phone.

MMS - Multimedia Messaging Service

Multimedia Messaging Services will provide a mechanism to send not only text messages as with the SMS (Short Message Service) but also drawings, photographs, music or voice clips and even short video. The system will operate on the store and forward principle with messages being stored and possibly formatted at a MMSC (Multimedia Messaging Service Centre) when sent between users. In order to maximize the full potential of MMS, the service will need to run over a 2.5G or 3G network.

MMS Relay/Server

A MMS Relay/Server is a network entity or application which is controlled by the MMS (Multimedia Messaging Service) provider. This entity transfers messages, provides specific operations to the mobile environment and provides storage services.

MMS UA - Multimedia Messaging Service User Agent

The Multimedia Messaging Service User Agent resides on a UE (User Equipment), a MS (Mobile Station) or on an external device connected to a mobile such as a laptop computer or personal information manager. It is an application layer function that provides the users with the ability to view, compose and handle Multimedia Messages.

MMSC - Multimedia Messaging Service Centre

The Multimedia Messaging Service Centre provides a store and forward facility for multimedia messages sent across a mobile network. The MMSC may also provide a formatting role to enable messages to be optimized to the receiving handset’s capability.

MMSE - Multimedia Messaging Service Environment

The Multimedia Messaging Service Environment is a collection of MMS (Multimedia Massaging Service) network elements that come under the control of a single administration. However in the case of roaming, the visited network is considered to be part of that user’s MMSE.

MMTel - Multimedia Telephony

MMTel is a 3GPP standardized, IMS based service which is designed to facilitate real-time communication based on voice and video telephony. In addition, real-time chat is also included, which encompasses features such as file sharing. Both VoLTE and ViLTE are based on the MMTel standards.

MMUSIC - Multiparty Multimedia Session Control

MMUSIC is a working group of the IETF(Internet Engineering Task Force) which is chartered to develop protocols to support Internet teleconferencing and multimedia communications. Most notably, the MMUSIC working group are responsible for the development of SDP (Session Description Protocol) and RTSP (Real Time Streaming Protocol).

mmWave - Millimetre Wave

A radio wave has a wavelength (λ) which corresponds to its frequency, for example 1GHz equates to a wavelength of ~30cm. The term mmWave typically refers to radio frequencies above 24GHz where the wavelength is measured in millimetres. For example, 24GHz equates to a radio wave with a ~12.5mm wavelength. mmWave frequencies are key for 5G, since the high frequencies are typically linked to high bandwidth opportunities.

MN - Mobile Node

A term used in Mobile IP to describe the mobile device that has moved from its home network to a foreign network.

MNC - Mobile Network Code

The Mobile Network Code is either a two or three digit number used to uniquely identify a given network from within a specified country ( MCC (Mobile Country Code)). The MNC is used as part of the IMSI (International Mobile Subscriber Identity) and LAI (Location Area Identity) etc.

MNRF - Mobile Station Not Reachable Flag

This flag is found at the HLR (Home Location Register) on either a GSM or UMTS mobile network. The flag indicates that a mobile is not reachable and thus prevents any further and unnecessary signalling. For example, the flag would be set in the event that a mobile station failed to respond to a paging message.

MNRG - Mobile Station Not Reachable For GPRS Flag

This flag is found at the HLR (Home Location Register) on either a GSM or UMTS mobile network. The flag indicates that the mobile is not reachable through a SGSN (Serving GPRS Support Node). The presence of this flag will prevent any unnecessary GPRS signalling.

MO - Managed Object

A Managed Object can be either a physical or logical resource which may be defined in terms of its attributes. These attributes may be controlled by a network manager through a manager agent interaction. Managed Objects form an important part of a TMN (Telecommunication Management Network).

MO - Mobile Originated

The general term used to describe the call leg on which the call is initiated (as opposed to Mobile Terminated).

MO-SMS-CSI - Mobile Originated-SMS-CSI

CAMEL Phase 3 introduced the ability for CAMEL interaction with MO (Mobile Originated) SMS. In Phase 4 this has been extended to cover MT (Mobile Terminated) SMS. The MO-SMS-CSI (Mobile Originated-SMS-CSI) and/or MT-SMS-CSI (Mobile Terminated-SMS-CSI) are passed down to the VLR and SGSN from the HLR. This is part of the Update Location Procedure.

Mobile - Mobile Device

The mobile device is termed the MS (Mobile Station) in GSM and the UE (User Equipment) in UMTS/LTE. The capabilities of the device are dependent on the manufacturer, but general features include support for a variety of radio technologies and frequencies, assisting in global roaming. Supported technologies include 3GPP technologies, as well as non-3GPP technologies such as WiFi, Bluetooth and NFC (Near Field Communication). Mobile devices are uniquely identified by their IMEI (International Mobile Equipment Identity), which is tracked by the EIR (Equipment Identity Register) in order to prevent stolen devices from accessing the network. On board the mobile will be a 3GPP SIM (Subscriber Identity Module) or USIM (Universal SIM), depending on the functionality of the device (particularly with respect to supported security algorithms). The SIM/USIM holds subscriber credentials associated with accessing services, such as the subscriber’s IMSI.

Mobile TV

This describes the notion of providing a subscriber with a TV service which is accessible on the subscriber’s mobile phone. Two high level mechanisms exist to achieve this: Unicast delivery, in which the TV content is distributed as a unicast data stream via the service provider’s existing data network and Broadcast/Multicast Delivery, in which the service provider utilizes a dedicated Mobile TV broadcast network in order to deliver the mobile content eg DVB-H, STiMi, MediaFLO, T-DMB etc. Both solutions have their relative disadvantages and merits. In both cases, the mobile network will be used for service control, such as changing channel or possible viewing the EPG.

Modem

A device used to modulate digital information so that it can be carried via an analogue carrier. The signal is then demodulated at the receive end to extract the original digital signal. The term comes from MOdulator and DEModulator.

MoIP - Multimedia over IP

MoIP is an expression used to describe the transport of various types of media as a payload of an IP datagram. Typical media examples include voice, messaging and video.

Monomode Fibre

A Monomode Fibre is an optical fibre which has been designed to carry light of a single wavelength.

MOP - Mean Output Power

This is the total transmitted power measured in a specific bandwidth at the antenna connector when the transmitter is active.

MOS - Mean Opinion Score

MOS is an indication of call quality based on the subjective opinion of the humans taking part in the call.

MOS-CQ - Mean Opinion Score – Conversational Quality

MOS-CQ is a call quality measurement which rates the overall quality of a call, taking into account listening quality, as well as conversational aspects such as whether or not delay or echo effected the call.

MP - Media Proxy

A generic term for the media handling and processing element of a Session Border Controller.

MP3

MP3 is the popular digital audio encoding format for audio based media, typically in the form of music or spoken word. MP3 is actually a contraction of MPEG-1 Audio Layer 3, which is the MPEG standard that defines the technology.

MPCI - Mobile Protocol Capability Indicator

A Mobile Protocol Capability Indicator is a 2bit field used to indicate the capabilities of a MS (Mobile Station).

MPDCCH - MTC Physical Downlink Control Channel

Introduced in Release 13 of the 3GPP specifications, MPDCCH is a eMTC specific channel that carries DCI (Downlink Control Information) in a eMTC NB (Narrowband).

MPEG - Moving Picture Experts Group

The Moving Picture Expert Group is a working group within ISO (International Standards Organization) who have developed the MPEG standards for the compression and coding of motion video.

MPEG-2

MPEG-2 is one of the predominant audiovisual compression system used in digital TV systems to date (along with MPEG-4). The technology is employed within hundreds of millions of digital and cable STBs, in addition to a host of personal computers and DVD players. A large proportion of the video seen on television today has been encoded with MPEG-2 at some point in its transmission.

MPEG-4

MPEG-4 is the successor to MPEG-2, which saw the introduction of the AVC (Advanced Video Codec)and enhancement of the AAC (Advanced Audio Codec), improvements which enable audio and video streams to be compressed into half the required bandwidth of MPEG-2 whilst maintaining the same level of quality. Like the improvements made between MPEG-1 and MPEG-2, this reduction in bandwidth is at the expense of increased CPU activity.

MPLS - Multi Protocol Label Switching

Multi Protocol Label Switching is a technique which allows IP datagrams to be labelled with a particular identifier. This label allows MPLS LSR to switch the packet to it’s appropriate destination over a preconfigured LSP , rather than route the packet on the basis of its IP addressing. The key drivers for deploying MPLS instead of a solely IP based transport network are Traffic Engineering, Pseudowires/VPN and finally, Protection and Restoration. It should be noted that MPLS was not designed to only work with IP – MPLS can be deployed in a number of transmission networks, such as those based on ATM, SDH and optical transmission (termed Generalized MPLS).

MPLS-TP - Multi Protocol Label Switching – Transport Profile

A profile of MPLS which has been designed to be specifically implemented as a transport technology within telecommunications networks. MPLS-TP removes certain functionality not required/desirable in a telecoms network, but also adds additional functionality largely associated with O&M.

MPS - Multimedia Priority Service

Multimedia Priority Service is a 3GPP feature designed to enable NS (National Security) or EP (Emergency Preparedness) subscribers to make priority calls or data session on a Service Providers network, particularly at times of congestion.

MR-DC - Multi RAT – Dual Connectivity

MR-DC is the general term given to a range of different Dual Connectivity configuration options, largely associated with 5G. With MR-DC, the Master RAN Node functions as the controlling entity, utilizing a Secondary RAN for additional data capacity. Example MR-DC configurations include EN-DC (E-UTRA – NR Dual Connectivity), NR-DC (New Radio Dual Connectivity), NGEN-DC (NG-RAN – E-UTRA Dual Connectivity) and NE-DC (NR – E-UTRA Dual Connectivity).

MR-DC - Multi-RAT Dual Connectivity

MR-DC is the general term given to a range of different Dual Connectivity configuration options, largely associated with 5G. With MR-DC, the Master RAN Node functions as the controlling entity, utilizing a Secondary RAN for additional data capacity. Example MR-DC configurations include EN-DC (E-UTRA – NR Dual Connectivity), NR-DC (New Radio Dual Connectivity), NGEN-DC (NG-RAN – E-UTRA Dual Connectivity) and NE-DC (NR – E-UTRA Dual Connectivity).

MRB - Multimedia Resource Broker

IMS Application Servers will routinely use the MRFs (Multimedia Resource Function) that are available in the network. In order to control access to the MRFs, Application Servers will send their requests via the MRB, which in turn will allocate a suitable MRF.

MRF - Multimedia Resource Function

This IMS entity, in conjunction with the S-CSCF and an AS, is responsible for carrying out a variety of processing tasks on media streams associated with particular services. These tasks include: coordination and distribution of voice traffic associated with a conference, playing of announcements to the subscriber eg. session failure or redirection announcements and finally, transcoding of voice or video streams to facilitate successful session establishment. The MRF is comprised of a MRFC and an MRFP.

MRFC - Multimedia Resource Function Controller

Forming the control aspect of the MRF (Multimedia Resource Function), the MRFC processes SIP requests received from the S-CSCF (Serving CSCF) and also Application Servers. Depending on the request, the MRFC will then invoke the services of an MRFP (Multimedia Resource Function Controller) as appropriate.

MRFP - Multimedia Resource Function Processor

Forming the media plane processing aspect of the MRF (Multimedia Resource Function), the MRFP provides a variety of services. These services include: conferencing, playing of announcements, audio transcoding, recording, media analysis etc. The full functionality of the MRFP is largely determined by the vendor, with different MRFPs having different capabilities. Commercially, the functionality of the MRFP is integrated into a platform commonly termed the Media Server.

MS - Mobile Station (3GPP)

The Mobile Station is the term used in GSM to describe the mobile phone. It is comprised of two distinct elements, the ME (Mobile Equipment) and the SIM (Subscriber Identity Module).

MS - Mobile Station (3GPP2)

The Mobile Station is a wireless terminal enabling the user to access network services over a radio interface. The MS consists of the ME (Mobile Equipment) and either a programmed UIM (User Identity Module) or a R-UIM (Removable – User Identity Module).

MS - Multicast Subscription

The mechanism by which a user subscribes or is subscribed to a multicast subscription group and thereby is authorised to join certain multicast services. Multicast subscription is performed either upon user selection or due to home environment initiation.

MSA - Mobile Security Association

A collection of security contexts which exist between a pair of nodes. These may be applied to MIP (Mobile IP) protocol messages which are exchanged between nodes. Each context will indicate an authentication algorithm and mode, a secret and a style of protection in use.

MSC - Mobile Switching Centre

A Mobile Switching Centre is a telecommunication switch or exchange within a cellular network architecture which is capable of interworking with location databases.

MSC-S - Mobile Switching Centre – Server

The MSC-S forms the call control and mobility management aspects of a distributed switch (a Soft Switch), interfacing the GERAN/UTRAN to the CS domain. From a control perspective, the MSC-S has the same responsibilities as a regular telephony exchange, with the addition of user location registration and handover management. An MSC-S will control one or more CS-MGW (Circuit Switched – Media Gateways). An MSC-S may function as a GMSC (Gateway MSC), which is the term given to an MSC which handles mobile terminated calls originating in an external network. For example, exchanges in the PSTN are unable to interrogate the HLR therefore the call is routed to the GMSC in order to assist onward routing.

MSCML - Media Server Control Markup Language

MSCML was initially defined in RFC 4722 and is carried as a SIP (Session Initiation Protocol) payload in order to control a MediaServer as part of an IMS (IP Multimedia Subsystem) service.

MSIN - Mobile Station Identity Number

The Mobile Station Identification Number forms part of the ITU-T (International Telecommunications Union – Telecommunications Standardization Sector) defined IMSI (International Mobile Subscriber Identity) to uniquely identify a mobile or subscription from within a given network. The MSIN is comprised of a maximum of 10 digits.

MSISDN - Mobile Station International ISDN Number

The Mobile Station International ISDN Number is the standard international telephone number used to identify a given subscriber. The number is based on the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) E.164 standard.

MSK - Minimum Shift Keying

Minimum Shift Keying is a form of FSK (Frequency Shift Keying) used to carry digital information on a radio carrier.

MSML - Media Sessions Markup Language

The Media Sessions Markup Language (MSML) is used to control and invoke many different types of services on IP mediaservers. Clients can use it define how multimedia sessions interact on a mediaserver and to apply services to individual or groups of users. MSML can be used, for example, to control media server conferencing features such as video layout and audio mixing, create sidebar conferences or personal mixes, and set the properties of media streams.

MSRN - Mobile Station Roaming Number

The Mobile Station Roaming Number is an E.164 defined telephone number used to route telephone calls in a mobile network from a GMSC (Gateway Mobile Switching Centre) to the target MSC.

MSRP - Message Session Relay Protocol

MSRP is used in IMS networks in order to support CPM (Converged IP Messaging). MSML sessions can be established between participants in order to allow chat sessions, file transfers etc to take place.

MSS - Mobile Soft Switch

The MSS (also termed MSC-S) is a term used to describe the call control and mobility management aspects of a distributed switch (a Soft Switch), interfacing the GERAN/UTRAN to the CS domain. From a control perspective, the MSC-S has the same responsibilities as a regular telephony exchange, with the addition of user location registration and handover management. An MSC-S will control one or more CS-MGW (Circuit Switched – Media Gateways). An MSC-S may function as a GMSC (Gateway MSC), which is the term given to an MSC which handles mobile terminated calls originating in an external network. For example, exchanges in the PSTN are unable to interrogate the HLR therefore the call is routed to the GMSC in order to assist onward routing.

MSU - Message Signalling Unit

The Message Signalling Unit provides the structure for transporting the higher layer protocol types in an SS7 network. These will include ISUP (ISDN User Part) TCAP (Transaction Capabilities Application Part) MAP (Mobile Application Part) and others. The difference between the MSU and signalling units such as LSSU (Link Status Signalling Unit) and FISU (Fill In Signalling Unit) is the MSU contains the SIO (Service Indicator Octet) and SIF (Service Information Field).

MT - Mobile Terminated

This is the term given to all communication which terminates at the mobile.

MT-SMS-CSI - Mobile Terminated-SMS-CSI

CAMEL Phase 3 introduced the ability for CAMEL interaction with MO (Mobile Originated) SMS. In Phase 4 this has been extended to cover MT (Mobile Terminated) SMS. The MO-SMS-CSI (Mobile Originated-SMS-CSI) and/or MT-SMS-CSI (Mobile Terminated-SMS-CSI) are passed down to the VLR and SGSN from the HLR. This is part of the Update Location Procedure.

MTC - Machine Type Communication

Also termed M2M (Machine to Machine), MTC describes data communication between two entities without the involvement of a human. This communication is typically between an MTC device and an MTC server, with a prime example being Smart Metering for utility services such as gas, water and electricity. MTC communication could also potentially be between MTC Devices, without the involvement of an MTC Server; in the case, a use application would be IoT (Internet of Things).

MTC-AAA - Machine Type Communications – Authentication, Authorization and Accounting.

Used within CIoT (Cellular Internet of Things) networks, the MTC-AAA supports the translation of an IMSI to an External Identity at the network egress.

MTC-IWF - Machine Type Communications – Interworking Function

Used within CIoT (Cellular Internet of Things) networks, the MTC-IWF enables the SCS (Service Capability Server) to send “triggers” to IoT devices over the Tsp reference point to instruct them to take some form of action such as registering with the SCS.

MTP - Message Transfer Part

MTP defines the lower three layers of the SS7 protocol stack. Layer 1 (MTP1) describes the Physical layer, defining how higher layer messages are represented on the transmission medium, including message delimiting. Layer 2 (MTP2) defines the Data Link layer, ensuring the reliable delivery of higher layer MSU (Message Signalling Units). Layer 2 also features FISU (Fill In Signalling Units) for link keep-alives, as well as LSSU (Link Status Signalling Units) in order to support signalling link establishment and maintenance. Layer 3 (MTP3) is comprised of two elements – SMH (Signalling Message Handling) and SNM (Signalling Network Management). SMH ensures higher layer signalling can be routed through the SS7 network (with the use of Point Codes). SNM is a route management facility for handling failures etc.

MTP1 - Message Transfer Part Level 1

Message Transfer Part Level 1 resides at Layer 1 of the OSI (Open Systems Interconnect) model. It is a 64Kbps channel which has been allocated for signalling purposes. This channel is referred to as a SL (Signalling Link). It is possible for multiple links to be utilized this leads to the expression SLS (Signalling Link Set).

MTP2 - Message Transfer Part Level 2

Message Transfer Part Level 2 resides at Layer 2 of the OSI (Open Systems Interconnect) model it is responsible for the reliable transmission of signalling units over an individual SL (Signalling Link). MTP2 reliability is achieved through retransmission techniques.

MTP3 - Message Transfer Part Level 3

Message Transfer Part Level 3 is the highest level of MTP (Message Transfer Part) it is split into two distinct parts SMH (Signalling Message Handling) and SNM (Signalling Network Management). Whilst the SNM part is looking after the general management of MTP the SHM part deals with the discrimination distribution and routing of signalling messages.

MTP3b - Message Transfer Part level 3 broadband

Message Transfer Part level 3 broadband provides message routing discrimination and distribution (for point to point link only). It also provides signalling link management load sharing and changeover between links within one link-set. The protocol is a broadband ISDN based protocol used typically in ATM (Asynchronous Transfer Mode).

MTRF - Mobile Terminated Roaming Forwarding

MTRF is a technique used in CSFB to reduce the delay that may take place in an MT fallback scenario in which the phone, at the point of fallback, attaches to a different MSC (usually due to Location Area mismatch). In this scenario, the call is forwarded from the MSC attempting to handle the call to the MSC actually responsible for the subscriber.

MTRR - Mobile Terminated Roaming Retry

MTRR is a technique used in CSFB to reduce the delay that may take place in an MT fallback scenario in which the phone, at the point of fallback, attaches to a different MSC (usually due to Location Area mismatch). In this scenario, the call attempt is bounced back from the original MSC handling the call, allowing the network to retry the call setup, this time to the correct MSC (the MSC to which the mobile has just registered).

MTU - Maximum Transmission Unit

A Maximum Transmission Unit is defined as the maximum packet size (in bytes or octets), that a particular interface can handle. For example, the MTU for Ethernet is 1500 bytes.

MTX - Mobile Telephone Exchange

A term used to describe a large exchange used within a cellular mobile system and connected to the PSTN.

MU-MIMO - Multi User

MIMO SDM (Spatial division multiplexing) of multiple modulation symbol streams to a single UE using the same time/frequency resource, is referred to as SU-MIMO (Single-User MIMO). However, spatial division multiplexing of modulation symbol streams to different UEs using the same time-frequency resource is referred to as MU-MIMO.

Multi mode UE

Multi mode UE Identifies a UE (User Equipment) that can obtain service from at least one mode of UMTS , FDD (Frequency Division Duplex) or TDD (Time Division Duplex), and one or more different systems such as GSM bands or possibly other radio systems which include the IMT-2000 (International Mobile Telephony 2000) family members.

Multicast

The term used to describe the broadcasting of messages or packets to a selected group of host devices situated on either a LAN (Local Area Network), WAN (Wide Area Network) or the Internet.

Multiframe

The term multiframe is used to describe a set of consecutive frames in which the position of each frame can be identified by reference to a multiframe alignment signal. Multiframes are commonly found in cellular communication systems including GSM , GPRS and UMTS.

Multimode Fibre

A Multimode Fibre is an optical fibre which has been designed to carry light at two or more different wavelengths at the same time.

Multipath

A form of radio fading caused by the existence of two or more paths between the transmitter and receiver. Delays on the reflected path may add to (strengthen) or subtract from (fade) the main path. Multipath may be overcome by using multiple receive antennas or frequency hopping.

Multiplex Option

Multiplex Option The ability of the multiplex sublayer and lower layers to be tailored to provide special capabilities. A multiplex option defines such characteristics as the frame format, the maximum number of SCC (Supplemental Code Channel) supported, and the rate decision rules.

Multiplex Sublayer

Multiplex Sublayer One of the conceptual layers of the system that multiplexes and demultiplexes primary traffic, secondary traffic, and signaling traffic.

Multiplexer

This is the term given to a device which multiplexes several signals onto a common transmission channel.

Multiplexing

This is the process where several users are able to share a common communication channel. Several different multiplexing techniques exist such as FDM (Frequency Division Multiplexing) and TDD (Time Division Multiplexing).

MUX

This is a term used to describe a device acting as a multiplexer and demultiplexer.

MWD - Messages Waiting Data

A part of the MWI (Message Waiting Indication) to be stored in the HLR (Home Location Centre). MWD consists of an address list of the SMSC (Short Message Service Centre) which have messages waiting to be delivered to the mobile.

MWI - Messages Waiting Indication

This indicates that there are one or more messages waiting to be delivered to the mobile due to previous unsuccessful delivery attempt(s ). The MWI is stored in the HLR (Home Location Register) and VLR (Visitor Location Register) with which an MS (Mobile Station) is associated.

N-ISDN - Narrowband-Integrated Services Digital Network

A Narrowband Integrated Services Digital Network is generally a digital network operating at 2.028Mbps or below.

N1 - N1 Reference Point

Related to the 3GPP 5G Architecture. The N1 Reference point is between the UE and the AMF (Access and Mobility Management Function).

N10 - N10 Reference Point

Related to the 3GPP 5G Architecture. The N10 Reference point is between UDM (Unified Data Management) and the SMF (Session Management Function).

N11 - N11 Reference Point

Related to the 3GPP 5G Architecture. The N11 Reference point is between the AMF (Access and Mobility Management Function and the SMF (Session Management Function).

N12 - N12 Reference Point

Related to the 3GPP 5G Architecture. The N12 Reference point is between the AMF (Access and Mobility Management Function) and the AUSF (Authentication Server Function).

N13 - N13 Reference Point

Related to the 3GPP 5G Architecture. The N13 Reference point is between UDM (Unified Data Management) and the AUSF (Authentication Server Function).

N14 - N14 Reference Point

Related to the 3GPP 5G Architecture. The N14 Reference point is between two AMFs (Access and Mobility Management Functions).

N15 - N15 Reference Point

Related to the 3GPP 5G Architecture. The N15 Reference point is between the PCF (Policy Control Function) and the AMF (Access and Mobility Management Functions) in the case of a non-roaming scenario, or the vPCF (Visited PCF) and AMF (Access and Mobility Management Functions) in case of a roaming scenario.

N16 - N16 Reference Point

Related to the 3GPP 5G Architecture. The N16 Reference point is between two SMFs. In a roaming scenario it would be between a Visited SMF and the Home SMF.

N2 - N2 Reference Point

Related to the 3GPP 5G Architecture. The N2 Reference point is between the (R)AN and the AMF (Access and Mobility Management Function).

N-ISDN - Narrowband-Integrated Services Digital Network

A Narrowband Integrated Services Digital Network is generally a digital network operating at 2.028Mbps or below.

N3 - N3 Reference Point

Related to the 3GPP 5G Architecture. The N3 Reference point is between the (R)AN and the UPF (User Plane Function).

N3IWF - Non-3GPP Interworking Function

This element of the 5G SBA (Service Based Architecture) is responsible for interworking between untrusted non-3GPP networks and the 5G Core. As such, the N3IWF supports both N2 and N3 based connectivity to the core, whilst supporting IPSec connectivity towards the device.

N4 - N4 Reference Point

Related to the 3GPP 5G Architecture. The N4 Reference point is between the SMF (Session Management Function) and the UPF (User Plane Function).

N5 - N5 Reference Point

Related to the 3GPP 5G Architecture. The N5 Reference point is between the PCF (Policy Function) and an AF (Application Function).

N6 - N6 Reference Point

Related to the 3GPP 5G Architecture. The N6 Reference point is between the UPF (UP Function) and a DN (Data Network).

N7 - N7 Reference Point

Related to the 3GPP 5G Architecture. The N7 Reference point is between the SMF (Session Management Function) and the PCF (Policy Control Function).

N7r - N7r Reference Point

Related to the 3GPP 5G Architecture. The N7r Reference point is between the vPCF (Visited PCF) and the hPCF (Home PCF).

N8 - N8 Reference Point

Related to the 3GPP 5G Architecture. The N8 Reference point is between UDM (Unified Data Management) and the AMF (Access and Mobility Management Function).

N9 - N9 Reference Point

Related to the 3GPP 5G Architecture. The N9 Reference point is between two Core UPF (User Plane Functions).

NA-ESRD - North American Emergency Services Routing Digits

A telephone number in the North American Numbering Plan that can be used to identify a North American emergency services provider and its associated LCS (Location Services) client. The ESRD also identifies the base station, cell site or sector from which a North American emergency call originates.

NA-ESRK - North American Emergency Services Routing Key

A telephone number in the North American Numbering Plan assigned to an emergency services call by a North American Visited PLMN (Public Land Mobile Network) for the duration of the call. The NA-ESRK is used to identify both the emergency services provider and the switch in the Visited PLMN currently serving the emergency caller. During the lifetime of an emergency services call, the NA-ESRK also identifies the calling mobile subscriber.

NACC - Network Assisted Cell Change

NACC was introduced to reduce the service outage period which is experienced by a mobile during a packet data session, as it cell reselects from one cell to another. With NACC, the serving BTS supplies the MS with system information for the new cell, before it reselects to that new cell. Utilizing this technique, the delay associated with acquiring the SI from the new cell is mitigated, hence service outage time is reduced. In 4G LTE, NACC can be used in support of CSFB (Circuit Switched Fallback), in order to make the fallback to 2G procedure a quicker process.

Naf - AF Service-based Interface

Naf is related to the 3GPP 5G Architecture. It identifies a Service-based Interface for the Application Function.

NAI - Network Access Identifier

RFC 4282 defines the concept of a NAI, which is a standardized method of identifying users who are attempting to access a network or service. NAI are typically in the from of user@realm such as Bob@domain1.

NAK - Negative Acknowledgement

A Negative Acknowledgement character or message indicates that a packet has arrived with the check digits in error. It is sent from the receiving unit to the transmitting unit and may cause the packet to be retransmitted.

NAM - Number Assignment module

The Number Assignment Module identifies the set of MIN (Mobile Identification Number) / IMSI (International Mobile Subscriber Identity) related parameters stored in the MS (Mobile Station).

Name Discovery

The mechanism that allows a device to request and receive a Bluetooth device name.

Namf - AMF Service-based Interface

Namf is related to the 3GPP 5G Architecture. It identifies a Service-based Interface for the Core Access and Mobility Management Function.

NAPTR - Naming Authority Pointer

The NAPTR (Naming Authority Pointer) record specifies a regular expression based rewrite rule that, when applied to an existing string, produces a new domain label or URI (Universal Resource Identifier). This allows DNS to be used to look up services for a wide variety of resource names that are not in domain name syntax. For more information, see RFC 2915.

NAS - Non Access Stratum

The Non Access Stratum is a functional layer running between the UE (User Equipment) and the CN (Core Network). The layer supports traffic and signalling messages between the CN and UE (User Equipment).

NAS – IuCS - Non Access Stratum (IuCS)

NAS signalling used on the IuCS reference point defines the set of signalling messages used between the mobile and the MSC in order to facilitate mobility management and call procedures.

NAS – Iur - Non Access Stratum (Iur)

NAS signalling encompasses the set of signalling messages used between the mobile and the SGSN in order to support GPRS SM (Session Management) and MM (Mobility Management).

NAS – UMTS - Non Access Stratum (UMTS)

NAS signalling operates between the mobile and the MSC/SGSN in order to facilitate mobility management, session management and call procedures.

NAS EMM - NAS EPS Mobility Management

The NAS protocol is used between the User Equipment and the MME in order to facilitate EPS Mobility Management and EPS Session Management procedures. Consequently, NAS protocol messages are classified as EMM or ESM, both of which can potentially be found in a single NAS message. An example of this would be during the initial attach, where the first message sent by the Mobile includes an EMM Attach Request, in addition to an ESM PDN Connectivity Request. Generally, NAS EMM messages are associated with the mobile’s presence or mobility on the network, encompassing procedures such as network attach, tracking area updates and network detach.

NAS ESM - Non Access Stratum EPS Session Management

In LTE, the NAS protocol is used between the User Equipment and the MME in order to facilitate EPS Mobility Management and EPS Session Management procedures. Consequently, NAS protocol messages are classified as EMM or ESM, both of which can potentially be found in a single NAS message. An example of this would be during the Initial Attach, where the first message sent by the mobile includes an EMM Attach Request, in addition to an ESM PDN Connectivity Request. Generally, NAS ESM messages are associated with user data sessions, such as establishing, modifying or terminated EPS bearers.

NASS - Network Access Sub System

In the TISPAN architecture, the NASS provides registration at the access ( IP ) level, managing IP address space and authenticating users. The NASS also announces the contact point of the IMS /TISPAN services to the user device.

NAT - Network Address Translation

Network Address Translation is a mechanism for reducing the need for globally unique IP addresses. NAT allows an organization with private addresses to connect to the Internet by translating those addresses into a globally unique and routable address.

NAT-T - NAT-Traversal

Certain protocols such as FTP and SIP can carry addressing information such as source and destination IP addresses and ports. When these protocols pass through NAT , this addressing will not be changed, since NAT typically works at the Transport and Network Layers. Therefore, the receiving entity will be supplied with addressing that is not relevant, such as private IP addressing or the wrong version of IP addressing. NAT traversal describes the process behind overcoming this issue, ensuring that addressing information delivered to the intended recipient is valid. There are several techniques which can be used for NAT traversal, such as ICE (Interactive Connectivity Establishment – a combination of STUN and TURN ), Session Border Controllers and UPnP (Universal Plug and Play).

Nausf - AUSF Service-based Interface

Nausf is related to the 3GPP 5G Architecture. It identifies a Service-based Interface for the Authentication Server Function.

NAV - Network Allocation Vector

The Network Allocation Vector is used within IEEE 802.11 networks to prevent Stations accessing the wireless medium and causing contention. The NAV is an indicator, maintained by each Station, of time periods when transmission will not be initiated even though the Stations CCA (Clear Channel Assessment) function does not indicate traffic on the medium.

NB - Narrowband

Found in eMTC (enhanced Machine Type Communications), this term identifies the use of 1.4MHz “Narrowbands” for CIoT (Cellular Internet of Things) operation.

NB - Normal Burst

A Normal Burst is used to carry both signalling and user information (circuit and packet switched) over the GSM air interface.

NB-IoT - Narrow Band – Internet of Things

This is a standards based LPWA (Low Power Wide Area) technology developed to enable a wide range of devices to connect within The Internet of Things. The technology supports a number of key features including low power consumption, radio spectrum efficiency and low cost. The technology can co-exist with existing 3GPP based 2G, 3G and 4G technologies and also benefits from the security features found within these networks.

NBA - NASS-IMS Bundled Authentication

NBA is an IMS authentication mechanism which is an alternative to IMS AKA. NASS-IMS is used when the access network is TISPAN based eg xDSL, where authentication is based on a specific user registering from a specific location. The NASS (Network Access Subsystem) is a feature of the TISPAN architecture.

NBAP - Node B Application Part

NBAP is used by the RNC (Radio Network Controller) to manage and configure Node Bs, as well as set up transport channels on the Iub and Uu interfaces. Additional responsibilities include Resource Blocking, Auditing, Measurement Reporting, Cell Synchronization and Information Exchange.

NC0 - Network Control Cell Reselection Mode 0

This is the normal mode of control for a GPRS mobile. In NC0 the MS (Mobile Station) performs autonomous cell reselection.

NC1 - Network Control Cell Reselection Mode 1

When operating in NC1, the GPRS mobile will pass measurement reports to the network. However the mobile will continue to perform autonomous cell reselection.

NC2 - Network Control Cell Reselection Mode 2

When operating in NC2, the GPRS mobile will pass measurement reports to the network. The mobile will only perform autonomous cell reselection when the reselection is triggered by a downlink signalling failure or a random access failure.

NCC - Network Colour Code

The Network Colour Code is broadcasted as part of the BSIC (Base Station Identity Code). It consists of 3bits, which are used to differentiate between operators utilizing the same frequencies. An example of when this will be required is on an international border when both operators have been allocated the same frequency or frequencies.

NCGI - New radio Cell Global Identity

In 5G, the NR (New Radio) cell is given a NCGI (NR Cell Global Identity). This concatenates the PLMN-Id (PLMN Identifier) and the 36bit NCI (NR Cell Identity). Note that a gNB may include multiple NCGIs.

NCGI - NR Cell Global Identity

In 5G, the NR (New Radio) cell is given a NCGI (NR Cell Global Identity). This concatenates the PLMN-Id (PLMN Identifier) and the 36bit NCI (NR Cell Identity). Note that a gNB may include multiple NCGI’s.

NCH - Notification Channel

Notification Channel is a generic channel used to provide information to a specific group of users. Typical examples of this include the group call service.

NCI - NR Cell Identity

In 5G, a service provider identifies a cell using an NCI (NR Cell Identity). This is a 36bit identity which can be concatenated with the PLMN-Id (PLMN Identifier) to form the NCGI (NR Cell Global Identity).

NCT - Network Connection Topology

The NCT is the connectivity in place between elements of a NFV (Network Functions Virtualization) network service. The individual connections which form the NCT are comprised of Virtual Links.

NDSS - Network Directed System Selection

This feature allows the MS (Mobile Station) to automatically register with a preferred system while roaming. It also enables the MS to be automatically directed by a service provider to a suggested system, regardless of the frequency band class, cellular band, or PCS (Personal Communications System) frequency block.

NE - Network Element 

A generic term used to describe equipment operating as part of a communication network.

NE-DC - NR – E-UTRA Dual Connectivity

NE-DC is a Dual Connectivity configuration utilizing the 5GC, whereby the master RAN is a 5G gNB and the secondary RAN node is a 4G ng-eNB.

NEF - Network Exposure Function

The Network Exposure Function is related to the 3GPP 5G Architecture. This function provides a means to securely expose the services and capabilities provided by 3GPP network functions. Example would include: 3rd party, internal exposure/re-exposure.

Neighbor Set

This is a set of pilots associated with the CDMA (Code Division Multiple Access) Channels that are likely candidates for handoff. Normally, the Neighbor Set consists of the pilots associated with CDMA Channels that cover the geographical area near the MS (Mobile Station).

NENA - National Emergency Number Association

NENA’s Mission is to foster the technological advancement, availability and implementation of a universal emergency telephone number system (9-1-1). In carrying out its mission, NENA promotes research, planning, training and education. The protection of human life, the preservation of property, and the maintenance of general community security are among Nena’s objectives. NENA are a USA based organization.

Network Slicing

Network Slicing is a 3GPP feature whereby the Service Provider can create a network which has been customized for a specific market vertical. Network Slicing is implemented via Network Slice Instance(s) which are created from a NST (Network Slice Template) and is based on network virtualization techniques.

NextGen - Next Generation

NextGen is a 3GPP term relating to 5G Next Generation network. It defines the NGS (NextGen System) which is made up of the NGC (NextGen Core) and NextGen RAN. Also see 5GS (5G System).

NF - Network Function

A Network Function is a logical node within a network infrastructure that has well-defined external interfaces and well-defined functional behaviour.

NFC - Near Field Communications

NFC is a short range, standards based wireless connectivity technology based on RFID which uses magnetic field induction to enable communication between electronic devices in close proximity. NFC operates in the standard unlicensed 13.56MHz frequency band (plus 847.5KHz) over a distance of approximately 20cm. To date, it supports data rates of 106Kbps, 212Kbps and 424Kbps although higher data rates are expected in the future.

NFM - Network Friendly Mode

Proposed by the GSMA, Network Friendly Mode is a non standardized feature of the communications module in an IoT device that polices the amount of time it will perform standard cellular procedures including IMSI Attach, GPRS Attach, PDP Context Activation etc. in order to reduce the number of signalling exchanges within the network.

NFVI - NFV Infrastructure

The NFVI is responsible for providing the compute, storage and networking resources that individual VNF (Virtualized Network Function) instantiations require. As such, a Hypervisor will typically provide the abstraction layer between the physical resources and VNFs, ensuring that VNFs are allocated resources when then need them.

NG RAN - NextGen RAN

The Next Generation Radio Access Network, is part of the 3GPP 5G NextGen System. The gNB (Next Generation Node B) is the new base station which facilities the new 5G radio techniques. Also see 5GS (5G System) and 5G-RAN (5G Radio Access Network).

NG UE - NextGen User Equipment

The Next Generation User Equipment, is part of the 3GPP 5G NextGen System. It support the new 5G NR (New Radio), as well as the Evolved E-UTRA and non-3GPP access types.

NGAP - NG Application Protocol

NGAP is found on the N2 reference point between the gNB and the AMF (Core Access and Mobility and Management Function) in order to support both UE and non UE associated services. This includes operations such as configuration updates, UE context transfer, PDU Session resource management and also support for mobility procedures. NGAP is also used to convey downlink and uplink NAS (Non Access Stratum) messages as a payload, as well as support CM Idle and CM Connected operations such as Paging and UE Context release.

NGC - NextGen Core

The Next Generation Core is part of the 3GPP 5G NextGen System. It support access from the new 5G RAN, as well as the Evolved E-UTRA and non-3GPP access types. Also see 5GS (5G System) and 5GC (5G Core Network)

NGEN-DC - NG-RAN – E-UTRA Dual Connectivity

NGEN-DC is a Dual Connectivity configuration utlizing the 5GC, whereby the master RAN is a 4G ng-eNB and the secondary RAN node is a 5G gNB.

NGEN-DC - NG-RAN – E-UTRA-NR Dual Connectivity

NGEN-DC is a Dual Connectivity configuration utilizing the 5GC, whereby the master RAN is a 4G ng-eNB and the secondary RAN node is a 5G gNB.

NGS - NextGen System

The 3GPP 5G NextGen System consists of the NGC (NextGen Core), NextGen RAN and NextGen UE (user Equipment). Also see 5GS (5G System).

NGSO - Non-Geostationary

NGSO satellites do not stand still with respect to the Earth. Therefore, in order to provide service continuity a number of satellites are required; this is referred to as a constellation. The lower the altitude of the satellites, then the higher the number of satellites that are needed. There are a number of different classes of NGSO: LEO, MEO and HEO.

NIC - Network Interface Card

A Network Interface Card allows a device to communicate across a network. This is generally a card that slots into a computer, printer etc. which stores a unique address ( MAC (Medium Access Control) Address) for that device.

NID - Network Identification

A number that uniquely identifies a network within a cellular or PCS (Personal Communication System).

NIDD - Non IP Data Delivery

For low power IoT devices which need to communicate with the network on a frequent or infrequent basis, utilizing an IP protocol stack for data delivery can be a power hungry process. NIDD allows the mobile and MME to utilize NAS signalling as a means of exchanging data messages related to IoT. This process is termed “EPS services with control plane CIoT (Cellular IoT) optimization”. The MME will act as the LTE network interface between the mobile and the SCEF (Service Capabilities Exposure Function).

NIST - National Institute of Standards and Technology

The National Institute of Standards and Technology is responsible for developing tests, measurements, reference data and other technical tools to support the development of information technology. NIST collaborates with national and international standards committees, users, and industry groups, in order that standards may be developed.

NLOS - Non Line of Sight

NLOS is a term used to describe an air interface which is capable of using multipath propagation to avoid the requirement for a line of sight propagation path between two wireless terminals such as a Mobile Station and a WiMAX Basestation.

NM - Network Management

A set of procedures, software, equipment etc in order to keep a network operating in an efficient manner. The ITU (International Telecommunications Union) have developed a series of standards for Network Management which are referred to as the TMN (Telecommunication Management Network). This sub-divides Network Management into the following five categories; Fault, Configuration, Performance, Accounting and Security.

NMC - Network Management Centre

A Network Management Centre can be described as the central point from which the entire network may be controlled. In most cases, an NMC will make use of several OMC (Operations and Maintenance Centre) to control specialist areas within the network.

NMSI - National Mobile Station Identity

A National Mobile Station Identity is part of an IMSI (International Mobile Subscriber Identity) and identifies the MS (Mobile Station) within its home country. The NMSI consists of the MNC (Mobile Network Code) and the MSIN (Mobile Subscriber Identification Number).

NMT - Nordic Mobile Telephony

An analogue cellular system developed by the Nordic PTT (Postal, Telegraph Telephone). Two versions existed NMT450 operating in the 450MHz band and NMT900 operating in the 900MHz band.

Nnef - NEF Service-based Interface

Nnef is related to the 3GPP 5G Architecture. It identifies a Service-based Interface for the Network Exposure Function.

NNI - Network to Network Interface

This is an internal interface within a network linking two or more elements.

Nnrf - NRF Service-based Interface

Nnrf is related to the 3GPP 5G Architecture. It identifies a Service-based Interface for the NF Repository Function.

Node-B - Node B

A Node B is a UMTS base station, relaying radio resource control and user plane information between the mobile and the network. Serving one or more cells, the Node B is controlled by an RNC (Radio Network Controller) as part of a UMTS RNS (Radio Network System).

Noise

The term noise generally refers to any unwanted signal in a transmission system.

Non GBR - Non Guaranteed Bit Rate

In LTE Dedicated bearers carry traffic for IP flows that have been identified to require a specific packet forwarding treatment. Dedicated bearers can be either GBR (Guaranteed Bit Rate) or non-GBR. A GBR bearer has a guaranteed bit rate and MBR (Maximum Bit Rate) while more than one non-GBR bearer belonging to the same UE shares an AMBR (Aggregate Maximum Bit Rate). Non-GBR bearers can suffer packet loss under congestion while GBR bearers are immune to such losses. Consequently these bearers are generally subject to admission control within the network.

Non-Connectable Device

A Bluetooth non-connectable device is one that does not respond to paging and is said to be in on-connectable mode

NP - Number Portability

This is the facility whereby subscribers may retain their telephone number when moving either location or to another carrier or operator.

Npcf - PCF Service-based Interface

Npcf is related to the 3GPP 5G Architecture. It identifies a Service-based Interface for the Policy Control Function.

NPDU - Network Protocol Data Unit

A Network Protocol Data Unit is a packet of data found at the network layer of the OSI (Open Systems Interconnection) seven layer model. The PDU (Protocol Data Unit) may contain either signalling or user information.

NPN - Non-Public Network

NPN is the 3GPP parlance for a Private 5G network deployment. Access to the NPN will be restricted, which means that regular 5G devices which routinely access the Public 5G network will not consider the NPN as a potential for RAN selection.

NR - New Radio

New Radio is the term relating to the 5G 3GPP radio.

NR-DC - New Radio Dual Connectivity

NR-DC is a Dual Connectivity configuration using the 5GC, whereby both the master and secondary RAN nodes are 5G gNBs.

NR-U - New Radio – Unlicensed

NR-U describes the ability of 5G NR to be deployed within the unlicensed spectrum band.

NR-V2X - New Radio – V2X

NR-V2X refers to the vehicle to vehicle communication that takes place between two vehicles over the PC5 interface utilizing the 5G New Radio technology. In V2X deployments, vehicles could be multi-technology capable and perform both NR-V2X and LTE-V2X over the PC5, vehicle to vehicle interface.

NRF - NF Repository Function

The NF (Network Function) Repository Function is related to the 3GPP 5G Architecture. This supports the service discovery function. As such, it is able to receive NF Discovery Request from a NF instance and can provide information about discovered NF instances.

NS - Network Service

The Network Service performs the transport of NS SDU (Service Data Unit) between the SGSN (Serving GPRS Support Node) and BSS (Base Station System). It also provides indications of congestion. The NS Layer is split into two sublayers, the Network Service Control layer and the Subnetwork Service layer. The Subnetwork Service layer currently utilizes Frame Relay.

NSA NR - Non-Standalone New Radio

A 3GPP 5G deployment configuration where the gNB (New Radio Node B) requires an LTE eNB as anchor for control plane connectivity to the EPC (Evolved Packet Core), or an ng-eNB as anchor for control plane connectivity to the 5GC (5G Core).

NSAPI - Network Service Access Point Identifier

The Network Service Access Point Identifier is an index to the PDP context that is using the services provided by the lower layer ( SNDCP (Sub Network Dependent Convergence Protocol)). One PDP may have several PDP contexts and NSAPI.

NSD - Network Service Descriptor

In the context of the NFV (Network Functions Virtualization) framework, a new Network Service would be on-boarded and instantiated into the system using an NSD. The NSD is essentially a collection of configuration documents, determining exactly how the Network Service is comprised in terms of required VNFs (Virtualized Network Functions) and their associated VNFFGD (VNF Forwarding Graph Descriptor). 

NSDU - Network Service Data Unit

A unit of data passed between the user and the GPRS network across a Network SAP (Service Access Point).

NSI - Network Slice Instance

A Network Slice Template is related to 3GPP Network Slicing. Network Slicing is implemented via Network Slice Instance(s) which are created from a NST (Network Slice Template).

Nsmf - SMF Service-based Interface

Nsmf is related to the 3GPP 5G Architecture. It identifies a Service-based Interface for the Session Management Function.

NSMS - Network Slice Management Service – Provider

In network slicing, the NSMS-P processes allocation requests received by an NSMS-C (Network Slice Management Service – Consumer) as part of NSI (Network Slice Instance) instantiation.

NSSAI - Network Slice Selection Assistance Information

The NSSAI is a collection of up to 8 S-NSSAI (Single – Network Slice Selection Assistance Information) and is sent to the network by the UE to assist the network in selecting a particular Network Slice.

NSSF - Network Slice Selection Function

The NSSF can be used by the AMF (Core Access and Mobility Management Function) to assist with the selection of the Network Slice instances that will serve a particular device. As such, the NSSF will determine the Allowed NSSAI (Network Slice Selection Assistance Information) that is supplied to the device. Moreover, the NSSF may be used to allocate an appropriate AMF if the current AMF is not able to support all network slice instances for a given device.

NSSI - Network Slice Subnet Instance

In network slicing, the NSSI forms part of the overall network slice instance. Examples include a RAN, core and transport NSSI.

NST - Network Slice Template

A Network Slice Template is related to 3GPP Network Slicing. The NST represents logical Network Function(s) and resource linked to the services and network capabilities required.

NT - Non Transparent

Non Transparent data transfer in GSM utilizes the RLP (Radio Link Protocol) to ensure error free data by adopting a retransmission mechanism. PDU (Protocol Data Unit) found to be incorrect will be discarded and a request for a retransmission will be made to the originator.

NTP - Network Time Protocol

NTP is a protocol designed to synchronize the clocks of computers over a network. Timestamp values are represented by 64bits, 32 of which represent seconds, with the remaining 32 representing fractions of a second. As such, NTP will wrap around in 2036.

NTU - Network Termination Unit

An Network Termination Unit is a device located at the final interconnect point between the PSTN (Public Switched Telephone Network) and the customers’ own equipment.

Nudm - UDM Service-based Interface

Nudm is related to the 3GPP 5G Architecture. It identifies a Service-based Interface for the Unified Data Management.

Null Modem

A Null Modem is a small box or cable which is used to join two computing devices directly, rather than across a network.

Null Traffic Channel Data

Null Traffic Channel Data is one or more frames of a specified data sequence which is sent at the lowest agreed upon rate of a negotiated radio configuration. This may be sent when there is no primary, secondary, or signaling traffic available.

NVFO - NFV Orchestrator

The NFVO is a functional element of MANO (Management and Orchestration), providing a critical role in the on-boarding and instantiation of VNFs (Virtualized Network Functions) and Network Services. The NFVO will also be involved in scale up/down of resources. In order to facilitate its role, the NFVO will routinely be in communication with the VNFM (VNF Manager) and the VIM (Virtualized Infrastructure Manager).

NWDAF - Network Data Analytics Function

The NWDAF is responsible for providing network analysis information upon request from network functions. For example, a network function may request specific analysis information on the load level of a particular network slice. Alternatively, the network function can use the subscribe service to ensure that it is notified by the NWDAF if the load level of a network slice changes or reaches a specific threshold.

Nyquist Theorem

The theorem proposed by Nyquist which states that an original analogue signal can be precisely recreated provided a specified minimum of samples are taken. In practical terms, it proposes that the maximum rate of transmission of pulses over a transmission channel is equal to twice the bandwidth of the channel without the risk of ISI (Inter Symbol Interference).

O-BCSM - Originating – Basic Call State Model

The BCSM (Basic Call State Model) is a high-level finite state machine description of the CCF (Call Control Function) activities required to establish and maintain communication paths for users who have IN services. For circuit switched operation there will be an Originating and Terminating BCSM.

O-CSI - Originating – CAMEL Subscription Information

CAMEL operation requires additional CSI (CAMEL Subscription Information) to be included as part of a mobile subscriber’s subscription information in the HLR. This will be forwarded to the appropriate VLR when the mobile attaches and moves around the network. There are two types of CSI these are O-CSI and T-CSI (Terminating – CAMEL Subscription Information). The later phases of CAMEL include many variations of CSI.

O-IM-CSI - Originating – IP Multimedia – CAMEL Subscription Information

CAMEL operation requires additional O-IM-CSI to be included as part of a mobile subscriber’s subscription information in the HSS. This will be forwarded to the appropriate S-CSCF when the mobile Registers in the IMS and moves around the network.

O&M - Operations & Maintenance

This term refers to the processes and functions used in provisioning and managing a network or element within a network.

OAM - Operations, Administration and Maintenance

This term refers to the processes and functions used in provisioning and managing a network or element within a network.

OBEX - Object EXchange Protocol

Object Exchange Protocol was originally developed to allow the exchange of data objects over an infrared link. It can also be used over other transport layers such as RFCOMM (Radio Frequency Communications protocol) and TCP/IP. OBEX offers the same features for applications as within the IrDA (Infrared Data Association) protocol hierarchy, enabling the applications to work over the Bluetooth protocol stack as well as the IrDA stack. This protocol is typically used for file transfer and business card or vcard transfer.

Object

The term object is commonly found in both telecommunication and computer networks. It can be described as an element within the network defined by a series of attributes. These are often collated within a MIB (Management Information Base). Within computing networks, an object can also be described as a unit of information

OCF - Online Charging Function

In the 3GPP IMS (IP Multimedia Subsystem) architecture, the OCF forms an integral part of the online charging system, determining whether or not, from a billing perspective, the customer is allowed to access network resources or services. The EBCF (Event Based Charging Function) and SBCF (Session Based Charging Function) are key elements of the OCF.

OCF - Open Connectivity Foundation

The Open Connectivity Foundation represents a number of companies involved in the development of standards to connect the billions of devices forming the IoT (Internet of Things). Members include Cisco, Intel, Qualcomm and Microsoft etc.

OCS - Online Charging System

The OCS is the main element of a service provider’s online (prepaid) billing architecture. In this capacity, the OCS interacts with a number of network nodes e.g. MSC, SGSN, PCEF, all of which can potentially provide billing related data. Core functions of the OCS include Rating (determining the units such as time, volume, etc in use and determining their price), subscriber account balance management, transaction control and advice of charge to external systems.

OCSP - Online Certificate Status Protocol

OCSP (Online Certification Status Protocol) has been developed as the requirements of e-commerce and m-commerce have evolved. This protocol provides real time access to CRL (Certificate Revocation Lists) enabling users to validate commerce sites as part of the transaction process.

OFB - Output Feedback

OFB is a mode of operation for symmetrical block ciphers which allows the block cipher mechanism to be used to create a synchronous stream cipher.

OFCS - Offline Charging System

The OFCS is the main element of a service provider’s offline (postpaid) billing architecture. In this capacity, the OFCS interacts with a number of network nodes e.g. MSC, SGSN, CSCF, all of which can potentially provide billing related data. The OFCS includes functions such as the CDF (Charging Data Function) and CGF (Charging Gateway Function) which are used to collect and present CDRs (Charging Data Records) to the billing domain.

OFDM - Orthogonal Frequency Division Multiplexing

OFDM is a multi carrier transmission technique capable of supporting high speed services whilst still being bandwidth efficient. It achieves this by forcing multiple sub-carriers together thereby reducing the bandwidth required when compared to more traditional FDM (Frequency Division Multiplexing)methods. However, to ensure these adjacent sub-carriers do not cause excessive interference, they must be orthogonal or 90 degrees to one another.

OFDMA - Orthogonal Frequency Division Multiple Access

OFDMA (Orthogonal Frequency Division Multiple Access) can be described as an extreme application of channelization. However, whereas OFDM sub-channelization is semi-static, OFDMA permits a more dynamic allocation of resources. Thus, OFDMA will allocate a number of sub-carriers for different symbol periods based upon network conditions and user’s requirements. This enables better utilization of the available bandwidth by minimizing waste.

OFTEL - Office of Telecommunications

Office of Telecommunications is a United Kingdom government organization set up in 1984 to regulate the UK’s telecommunication industry.

OIC - Open Interconnect Consortium

This is the former name of the organization now known as the OCF (Open Connectivity Foundation).

OIP - Originating Identification Presentation

OIP is a supplementary service in which the network provides the Called Party with the trusted identity of the Calling Party.

OIR - Originating Identification Restriction

OIR is a supplementary service in which the network does not provide the Called Party with the Calling Party’s identity.

OLT - Optical Line Termination

OLT is the name given to the optical device that sits at the head end of a PON or FTTx system. As such, the OLT is responsible for coordination of a number of ONU , particularly with respect to the allocation of upstream bandwidth to these devices. In addition, the OLT is the point at which downstream traffic is broadcast to the ONU via the optical distribution system.

OMA - Open Mobile Alliance

The OMA was formed in the summer of 2002 by a number of companies including the world’s leading mobile operators, device and network suppliers, information technology companies and content and service providers. OMA is primarily involved with the development of interoperable end-to-end mobile services.

OMA-DM - Open Mobile Alliance Device Management

OMA Device Management can through a Management Authority remotely set parameters, conduct troubleshooting servicing of terminals, install or upgrade software. By using the interfaces specified by the OMA DM Client Framework API, applications running on the device can access the DM Tree and interact with Management Objects and the DM Server, in order to obtain configurations or report data.

OMC - Operations Maintenance Centre

An Operations and Maintenance Centre is an element within a network management system responsible for the operations and maintenance of a specific element or group of elements. For example an OMC-Radio may be responsible for the management of a radio subsystem whereas an OMC-Switch may be responsible for the management of a switch or exchange. However, these will in turn be under the control of a NMC (Network Management Centre) which controls the entire network.

OML - Operations and Maintenance Link

OML is used for supporting network management procedures (transferring O&M messages).

ONF - Open Networking Foundation

The ONF have been a key figurehead in the promotion and standardization of SDN (Software Defined Networks). In particular, the ONF standardize OpenFlow, a widely used and popular protocol choice for the Southbound API between the SDN Controller and the network resources.

ONU - Optical Network Unit

An Optical Network Unit is a device used to terminate a fibre optic line and is often situated close to the subscriber’s site. This terminology is used in PON (Passive Optical Network) architectures to describe the CPE.

OPC - Operation Code

This is a TCAP variable and is used to identify the information flow contained within the CSL (Component Sublayer) of a TCAP message. The typical information flow would be either CAMEL or MAP messages.

OPEX - Operational Expenditure

General term which describes the day to day cost of running a network, encompassing a wide variety of contributing factors.

Optical Budget

This is a parameter used in the design of optical transmission networks. It is the difference between output power level of the source and the receiver sensitivity. It is generally measured in dB (Decibel).

ORB - Object Request Broker

Within an Object based communication system, an ORB keeps track of the actual addresses of all defined objects and thus is used to route traffic to the correct destination. The CORBA (Common Object Request Broker Architecture) defines the ORB in a series of standards enabling different platforms to share common information.

OS - Operating System

This can be described as the software within a computer which controls basic functions. Examples of operating systems include Windows, DOS and Linux.

OSA - Open Service Access

OSA (Open Services Access) is a joint initiative between the 3GGP, ETSI and the Parlay Group which is designed to facilitate the design and implementation of service architectures in mobile networks. OSA services have an open API (Application Programming Interface) termed Parlay, which developers can use as the basis for server design. In the IMS (IP Multimedia Subsystem), OSA servers may require a SCS (Service Capability Server) in order to support integration with a SIP (Session Initiation Protocol) based network.

OSI - Open System Interconnection

Refers to a 7 layer reference model developed by the OSI.

OSPF - Open Shortest Path First

Open Shortest Path First is a link state, hierarchical IGP (Interior Gateway Protocol) routing algorithm. Features supported by OSPF include least cost routing, multipath routing and load balancing.

OSS - Operations Support System

Operations Support System can be described as a network management system supporting a specific management function, such as fault, performance, security, configuration etc.

OTD - Orthogonal Transmit Diversity

An optional method of transmission of the Forward CDMA Channel that utilizes two antennas, each transmitting a fraction of the code symbols. It is used to enhance the performance in the presence of fades due to multipath propagation.

OTDOA - Observed Time Difference On Arrival

OTDOA is a subscriber location technique which was introduced in Release 9 of the 3GPP specifications. OTDOA is based on the mobile taking TDOA measurements from the PRS (Positioning Reference Signal) associated with the neighbouring eNBs that the mobile is able to receive. These measurements are then supplied to the ESMLC (Enhanced Serving Mobile Location Centre) by the mobile, which the ESMLC is able to utilize in order to calculate the location of the mobile.

OTI - Originating Transaction Identifier

The OTI is a TCAP variable and is used to associate request and response messages within the TCAP Transaction Sublayer.

OTN - Optical Transport Network

OTN (Optical Transport Network) is designed to improve transport network performance using fibre optic technology, with the ultimate goal to facilitate migration to very high backbone transport bandwidths. The actual OTN standard is ITU-T G.709, which provides the network interface definitions for an OTN deployment.

OTT - Over The Top

A term used to describe the delivery of communication services over the top of an existing transport network, without any relationship between the OTT service provider and the transport network service provider. An example would the use of Skype over a mobile network to conduct a voice call.

Out of Band Signalling

Out of Band Signalling utilizes an additional signalling channel alongside the data information channel to carry control information such as signalling.

Overhead

This can be described as information added to a user’s transmitted message for the purpose of control. Such overhead includes error checking and synchronization information.

Overlay Network

This is a telecommunication network which is added over essentially the same route as an existing network yet does not replace it. The overlay network usually carries supplementary services.

P-CCPCH - Primary Common Control Physical Channel

There is only one Primary Common Control Physical Channel within a cell, and it is used to carry synchronization and broadcast information for users. The frame structure of the Primary CCPCH differs from the downlink DPCH (Dedicated Physical Channel) in that no TPC (Transmit Power Control) commands, no TFCI (Transport Format Combination Indicator) and no pilot bits are transmitted. The Primary CCPCH is not transmitted during the first 256 chips of each slot. Instead, Primary SCH (Synchronization Channel) and Secondary SCH are transmitted during this period, the remainder being used for broadcast messages.

P-CSCF - Proxy – Call Session Control Function

The P-CSCF acts as the ingress and egress point to and from a service provider’s IMS domain with respect to the IMS client. The P-CSCF has a large number of responsibilities, including: onward routing of registration and session requests to the correct nodes in the network, ensuring the S-CSCF (Serving CSCF) is kept updated on the access network the subscriber is using, providing session information to the PCRF (Policy and Charging Rules Function) and maintaining a secure connection with the client device.

P-GW - Packet Data Network Gateway

The P-GW serves as an ingress and egress point to the EPC from a PDN (Packet Data Network) such as the Internet. When a subscriber establishes an EPS (Evolved Packet System) bearer to a given PDN, the P-GW serves as the point of attachment to that PDN for the life of the EPS bearer (regardless of any mobility procedures). Packet filtering is a key role of the P-GW in order to ensure that downlink data has the appropriate QoS applied. This is associated with PCC (Policy and Charging Control), with the P-GW typically housing PCEF (Policy and Charging Enforcement Function) capabilities.

P-GW - PDN Gateway

The P-GW serves as an ingress and egress point to the EPC from a PDN (Packet Data Network) such as the Internet. When a subscriber establishes an EPS (Evolved Packet System) bearer to a given PDN, the P-GW serves as the point of attachment to that PDN for the life of the EPS bearer (regardless of any mobility procedures). Packet filtering is a key role of the P-GW in order to ensure that downlink data has the appropriate QoS applied. This is associated with PCC (Policy and Charging Control), with the P-GW typically housing PCEF (Policy and Charging Enforcement Function) capabilities.

P-RNTI - Paging

The E-UTRA Paging Control Channel uses a P-RNTI (Paging – Radio Network Temporary Identifier) which is set to 0xFFFE and is used to CRC encode the paging messages.

P-SCH - Primary Synchronization Channel

The UMTS Primary SCH (Synchronization Channel) is a downlink signal used for cell search. The SCH consists of two sub channels, the Primary and Secondary SCH. The 10ms radio frames of the SCH are divided into 15 slots, each of length 2560chips. The Primary SCH consists of a modulated code of length 256chips, and is transmitted once every slot.

P-TMSI - Packet – Temporary Mobile Subscriber Identity

The P-TMSI is a temporary identity issued to a GPRS enabled mobile, unique within a given RA (Routing Area), and is used by the GPRS network to page the specified mobile. The P-TMSI is comprised of 32bits and is associated with the TLLI (Temporary Logical Link Identifier).

P/F - Poll / Final Bit

A Poll/Final bit is often found in data link layer protocols and is used to indicate the function of a frame. If the frame is a command a one in this bit indicates a poll. If the frame is a response a one in this bit indicates that the current frame is the final frame.

PABX - Private Automatic Branch Exchange

A Private Automatic Branch Exchange is a private switch or exchange often found within a company. The PABX will perform the switching of local calls within the organization as well as setting up external connections with the local operator or carrier.

PACA Call - Priority Access and Channel Assignment Call

A priority MS (Mobile Station) originated call for which no traffic or voice channel was immediately available, and which has been queued for a priority assignment.

PACCH - Packet Associated Control Channel

The Packet Associated Control Channel conveys signalling information related to a given GPRS mobile such as acknowledgements and power control information. The PACCH also carries resource assignment and reassignment messages.

Packet

A packet can be described as a logical grouping of information including header and (usually) user data. Packets most often are used to refer to network layer units of data and are also often called datagrams, frames, messages, PDU (Protocol Data Unit) to name but a few.

Packet error Ratio

Identifies the ratio of good to bad packets.

Packet Filtering

Packet Filtering is the method for determining how IP packets should be handled by a network device. When IPSec is employed, all IP packets passing the IPSec engine are filtered and may be modified, passed intact, or dropped.

Packet Idle Mode

In packet idle mode, the MS (Mobile Station) is prepared to transfer packet data. The MS however has not been allocated any radio resource on a PDCH (Packet Data Channel).

Packet mode

In this mode the GPRS mobile is ready to access and operate on a packet data physical channel. The packet mode includes two substates: packet wait state and packet transfer state.

PAD - Packet Assembly / Disassembly

A Packet Assembly / Disassembly is a device used to assemble and disassemble packets enabling simple devices to connect to a packet switched network such as X.25. A PAD may also carry out buffering.

PAGCH - Packet Access Grant Channel

The Packet Access Grant Channel is used in the GPRS packet transfer establishment phase to send resource assignment to a MS (Mobile Station) prior to packet transfer.

PageState

The Page State is a mode that a Bluetooth device enters when searching for other devices. The device sends out a page to notify other listening devices that it is looking for devices and the possible services.

Paging - Bluetooth

A Bluetooth unit transmits paging messages to other Bluetooth units who are active within the coverage area. This enables a communication link to be established.

Paired

In Bluetooth, two devices are Paired together and in so doing exchanging connection information. This information includes the Device Name , Passkey and any other relevant information, thus allowing devices to automatically and seamlessly connect together.

Pairing

Pairing is a Bluetooth term used to identify the exchange of a Link Key between two devices. These devices will use the link key for any future secure exchange of information.

PAM - Pulse Amplitude Modulation

This is a process of representing a continuous analogue signal with a series of discrete analogue samples. The process is used in PCM (Pulse Code Modulation) during the conversion of an analogue signal into a digital representation.

PAN - Personal Area Network

A Personal Area Network is a group of personal devices, communicating seamlessly together. This is also referred to as a WPAN (Wireless Personal Area Network), an example being the Bluetooth system.

PAP - Password Authentication Protocol

The Password Authentication Protocol allows PPP (Point to Point Protocol) peers to authenticate one another. The remote device attempting to connect to the local device is required to send an authentication request. PAP does not itself prevent unauthorized access but merely identifies the remote end.

Park Mode

The Park Mode is when a Bluetooth device is synchronized to the piconet but does not participate in traffic transfer. Parked devices relinquish their AM_ADDR (Active Member Address) address and monitor the master for broadcast messages. The Park mode conserves the most power compared with other power saving modes, Sniff Mode and Hold Mode.

Passkey

In Bluetooth, a Passkey is used to authenticate incoming device connections. These Passkeys are only valid for that connection.

PAT - Port Address Translation

Port Address Translation or sorting is a feature which allows many devices on a LAN (Local Area Network) to share one IP address by allocating a unique port address at layer four. The system is popular as in enables greater efficiency of the limited IPv4 (IP version 4) address space.

Path Loss

Path Loss is said to occur when RF (Radio Frequency) waves are transmitted through the air. This loss occurs due to atmospheric influences and interaction with objects, which can have a filtering effect on the signal.

Payload

A payload can be described as the portion of a cell, frame, or packet that contains upper layer information (data).

PBB - Provider Backbone Bridges

Standardized as IEEE 802.1ah-2008, PBB allows customers to connect their Ethernet VLAN s across a service provider’s network, whilst keeping their own VLAN traffic separate from other customers of the service provider. As such, it is actually the service provider that needs to deploy a PBB capable network, which will take customer traffic and add an additional Ethernet header. The header contains information and identifiers which ensure that customer traffic will be sent to the correct egress point in the network and will also be kept separate from other customer traffic.

PBB-TE - Provider Backbone Bridge Traffic Engineering

PBB-TE is based on the earlier PBB standard, which uses a series of identifiers to ensure that customer traffic can be kept separate and can be delivered to the correct egress point whilst transiting a service provider network. PBB-TE, as the title suggests, introduces traffic engineering into the architecture, which essentially means that prior to the customer traffic hitting the network, the route the customer traffic will take has already been preconfigured in the network. This preconfigured route will be established based on the requirements of the customer traffic, in much the same way as existing traffic engineering mechanisms. Therefore, PBB-TE is different to PBB in the sense that STP is not required and also flooding is not allowed.

PBCC - Packet Binary Convolutional Coding

PBCC is an optional method of error protection which may be used in IEEE (Institute of Electrical and Electronics Engineers) 802.11 networks. Its support within a network is broadcast in the beacon message.

PBCCH - Packet Broadcast Control Channel

The Packet Broadcast Control Channel broadcasts packet data specific PSI (Packet System Information). If PBCCH is not allocated, the packet data specific system information will be broadcast on BCCH (Broadcast Control Channel).

PBCH - Physical Broadcast Channel

This channel is used in E-UTRA to carry the RRC MIB (Master Information Block). The MIB utilizes the BCH Transport Channel and BCCH Logical Channel. The PBCH includes physical layer error protection and formatting, as well as being located in a predefined position for FDD/TDD radio frames.

PC - Privacy Class

The Privacy Class is a list of LCS (Location Services) clients defined within a privacy exception class to which permission may be granted to locate the target mobile. The permission is granted either on activation by the target mobile or permanently for a contractual period of time agreed between the target mobile and the service provider.

PC5 LINK-AMBR - PC5 Link Aggregate Maximum Bitrate

In 5G V2X, PC5 unicast links are limited using PC5 LINK-AMBR. This limits the aggregated bit rate that can be expected across all non-GBR QoS Flows with a peer device. It is measured over an averaging window and is only applicable to non-GBR Flows.

PCC - Policy and Charging Control

The PCC (Policy and Charging Control) architecture has been specified by the 3GPP as a mechanism which enables packets flowing through an IP-CAN to be associated with a particular charging key for both online and offline billing. In addition, PCC also provides policy control, in which a PCRF (Policy Control and Charging Rules Function) interacts with a PCEF (Policy Charging and Control Enforcement Function) in order to provide instruction on the control of the IP-CAN. PCC is a technique which can be used within the IMS to provide policy and charging control between IMS entities (namely the P-CSCF ) and the IP-CAN.

PCCCH - Packet Common Control Channel

The Packet Common Control Channel comprises of logical channels for GPRS common control signalling. These subchannels include: PRACH (Packet Random Access Channel), PPCH (Packet Paging Channel), PAGCH (Packet Access Grant Channel) and PNCH (Packet Notification Channel).

PCCH - Paging Control Channel

Paging Control Channel (PCCH) A downlink channel that transfers paging information. This channel is used when the network does not know the location cell of the UE (User Equipment), or, the UE is in the cell connected state but utilizing UE sleep mode procedures.

PCEF - Policy and Charging Enforcement Function

The PCEF is a DPI (Deep Packet Inspection) device responsible for the enforcement of rules which have been configured statically or supplied to the PCEF dynamically from the PCRF (Policy and Charging Rules Function). The PCEF sits on the user plane, ensure that subscriber traffic flows are treated in accordance with network policy e.g. implementing QoS, throttling traffic, blocking traffic, etc. Crucially, the PCEF will ensure that services are billed accordingly.

PCF - Point Coordination Function

When contention free operation is required in an IEEE 802.11 network, special wireless stations called Point Coordinators are utilized which enable other stations to transmit frames after a shorter than normal time interval. Point Coordinators are only found in AP (Access Point) and as such PCF operation is restricted to Infrastructure networks.

PCF - Policy Control Function

The Policy Control function is related to the 3GPP 5G Architecture. This function supports the unified policy framework that governs network behaviour. In so doing, it provides policy rules to control plane function(s) to enforce them. In order to facilitate this the subscription information is gathered from the Unified Data Management function.

PCF - Positioning Calculation Function

The Positioning Calculation Function is responsible for calculating the position of the mobile. It obtains BTS (Base Transceiver Station) related data e.g., BTS geographic co-ordinates and stores this data. This function applies an algorithmic computation on the collected signal measurements to compute the final location estimate and accuracy. It also supports conversion of a mobile’s location estimate between different geodatic reference systems.

PCFICH - Physical Control Format Indicator Channel

The PCFICH (Physical Control Format Indicator Channel) is used to inform the UE about the number of OFDM symbols (1, 2 or 3) used for the PDCCH in a subframe. This channel consists of 32bits which are cell-specific scrambled prior to modulation and mapping.

PCH - Paging Channel (Generic)

The Paging Channel is used to alert a mobile that there is a call or text message waiting. The alert is broadcast from all cells within a given area.

PCFICH - Physical Control Format Indicator Channel

The PCFICH (Physical Control Format Indicator Channel) is used to inform the UE about the number of OFDM symbols (1, 2 or 3) used for the PDCCH in a subframe. This channel consists of 32bits which are cell-specific scrambled prior to modulation and mapping.

PCH - Paging Channel (Generic)

The Paging Channel is used to alert a mobile that there is a call or text message waiting. The alert is broadcast from all cells within a given area.

PCI - Physical Cell Identity

This is used in E-UTRA systems to identify a cell. Its value is dependant on the combination of PSS (Primary Synchronization Signal), numbered 0 to 2 and the SSS (Secondary Synchronization Signal) numbered 0 to 167. This effectively allows for 504 combinations which are reused in the cell planning and optimization phases. The PCI value can be reused within the network and different radio carriers on the same eNB can also reuse the same PCI.

PCM - Pulse Code Modulation

Pulse Code Modulation is the process in which an analogue signal is encoded into a digital bit stream. The analogue is first sampled, then quantized and finally encoded into a bit stream. The most common version of PCM enables one voice circuit to be represented by a 64Kbps stream. Other versions of PCM exist such as ADPCM (Adaptive Differential PCM) which enables lower bit rates to be achieved.

PCMCIA - Personal Computer Memory Card International Association

Technical standard for small cards which are able to plug into notebooks to provide enhanced functions. Common examples include network cards, modem cards and security cards.

PCN - Personal Communication Network

Term initially used to describe cellular operators utilizing the 1800MHz frequency band. These networks are now known as GSM1800 networks.

PCO - Protocol Configuration Options

PCO is used in LTE as a means by which the mobile can indirectly exchange information with the P-GW. The information is typically related to particular PDN connection, with examples of PCO information including the address of a DNS server and IP address of the P-CSCF (for VoLTE operation).

PCPCH - Physical Common Packet Channel

In UMTS the Physical Common Packet Channel is used to carry the CPCH (Common Packet Channel). Each cell scrambling code is allocated a possible 64 PCPCH codes.

PCR - Parameter Change Registration

The process by which a mobile registers when some of its stored parameters change.

PCR - Peak Cell Rate

This is an ATM (Asynchronous Transfer Mode) term to describe the rate in cells per second that the source device may never exceed.

PCRF - Policy and Charging Rules Function

The PCRF is a policy decision point for subscriber data flows in the network. Using inputs from other network nodes, the PCRF will formulate rules which control how traffic flows (required QoS, restrictions, throttling, blocking, billing, etc) over the network down to individual subscriber granularity. The PCRF passes these rules to the PCEF (Policy and Charging Enforcement Function).

PCS - Personal Communication System

Personal Communication System is the term given to cellular phone technologies within the USA. PCS1900 (Personal Communication System 1900) is a well known standard that is based on DCS1800 (Digital Communication System 1800) but shifted up through 100MHz of spectrum.

PCU - Packet Control Unit

The Packet Control Unit is a device found within a GPRS network which is logically associated with a BSC (Base Station Controller). The PCU is responsible for the radio related aspects of GPRS when connected to a GSM network and lies between the BTS (Base Transceiver Station) and the SGSN (Serving GPRS Support Node).

PDA - Personal Digital Assistant

A Personal Digital Assistant can be generally described as a small handheld computer holding such information as diaries, address books etc.

PDCCH - Physical Downlink Control Channel

The PDCCH control area size is defined by the PCFICH , i.e. 1, 2 or 3 OFDM symbols. The E-UTRA PDCCH carries scheduling assignments and other control information. It is transmitted on an aggregation of one or several consecutive CCE (Control Channel Element), where a CCE corresponds to nine REG s.

PDCH - Packet Data Channel

The Packet Data Channel is a general term used in GPRS to represent a timeslot given over to the control of GPRS rather than conventional GSM circuit switching. As such, it may carry either signalling or user data.

PDCP (LTE) - Packet Data Convergence Protocol

PDCP fundamentally provides a compression service to higher layer data, which may be control plane or user plane (IP) traffic. When the LTE variant of PDCP compresses data, a separate standard termed ROHC (Robust Header Compression) is utilized (UMTS PDCP can use ROHC and an earlier standard termed IP Header Compression). Moreover, the LTE variant of PDCP is also responsible for implementing ciphering and integrity checking.

PDCP (UMTS) - Packet Data Convergence Protocol

Packet Data Convergence Protocol is used in UMTS to format the data into a suitable structure prior to transfer over the air interface.

PDF - Policy Decision Function

To support policy in IP networks a simple architecture based upon a policy server and policy aware network routers is deployed. The policy server is termed the PDF and uses a protocol such as COPS to communicate policy information to the PEF (Policy Enforcement Function). Using policy information access, network resources etc are allocated to the network user.

PDH - Plesiochronous Digital Hierarchy

A common standard utilized throughout the world to multiplex digital information. Due to limitations such as lack of flexibility and performance it has been superseded in many areas by SDH (Synchronous Digital Hierarchy).

PDI - Packet Detection Information

PDI is found within a PFCP PDR (Packet Data Rule), outlining key filter elements that should be applied in order to detect a specific packet e.g. IP address, port information.

PDN - Public Data Network or Packet Data Network

This is a generic term for a network providing data services. Examples include the Internet , Intranet and IMS (IP Multimedia Subsystem).

PDN-GW - PDN Gateway

Within the EPC the PDN Gateway terminates the SGi interface and is responsible for functions such as policy enforcement, based around the monitoring of traffic characteristics on a subscriber by subscriber basis to ensure that the agreed traffic policy is being adhered to. Other tasks include packet filtering and screening for things such as Malware and unauthorized data types, as well as accounting, IP Address Allocation and Lawful Interception.

PDP Address

The PDP (Packet Data Protocol) Address conforms to the standard addressing scheme of the respective network layer service used, e.g. IPv4 (IP version 4), IPv6 (IP version 6) or X.25 etc.

PDP Context

A PDP (Packet Data Protocol) Context is a logical association between a MS (Mobile Station) and PDN (Public Data Network) running across a GPRS network. The context defines aspects such as Routing, QoS (Quality of Service), Security, Billing etc.

PDP Type

When establishing a PDP Context the PDP Type indicates what type of protocol is to be used by the mobile for a certain service, e.g. IP and X.25.

PDR - Packet Detection Rule

A PDR contains information required to classify a packet arriving at a UP function, e.g. a TDF-U, a PGW-U or a SGW-U. There will be at least one PDR for both the uplink and the downlink. The PDR will contain various amounts of information depending upon the user function type. This will include a unique session and rule identity and also packet detecton information such as source information, service data flow filter and application identity.

PDS - Packet Data Session

Generic term used to describe a session during which a user will invoke and utilize a packet data service.

PDSCH - Physical Downlink Shared Channel

In LTE the PDSCH carries the DL-SCH (Downlink Shared Channel). This is the only downlink transport channel available to carry user data between the mobile device and the eNB.

PDSN - Packet Data Serving Node

Packet Data Serving Node is responsible for the establishment, maintenance and termination of a PPP (Point to Point Protocol) session towards the MS (Mobile Station). It may also assign dynamic IP addresses in addition to supporting Mobile IP functionality. It provides a similar function to the GSN (GPRS Support Nodes) found in GSM and UMTS networks.

PDTCH - Packet Data Traffic Channel

A Packet Data Traffic Channel is a channel allocated for data transfer. It is temporarily dedicated to one MS (Mobile Station) or to a group of mobiles in the Point to Multipoint – Multicast case. In multislot operation, one MS may use multiple PDTCH in parallel for individual packet transfer.

PDU - Protocol Data Unit

A Protocol Data Unit comprises of data and control information which is passed between layers in a protocol stack.

PE - Provider Edge

PE describes the border between a service provider’s network and the customer. PE routers are often deployed at the PE in order to facilitate interaction.

PEAP - Protected Extensible Authentication Protocol

PEAP is an authentication method used to transmit authentication information, including passwords, over wired or wireless networks. It was jointly developed by Cisco Systems, Microsoft, and RSA Security. PEAP is similar to EAP-TTLS (Extensible Authentication Protocol – Tunnelled Transport Layer Security).

PEI - Permanent Equipment Identifier

In 5G, the PEI is the means by which the network identifies the User Equipment (for devices that are capable of accessing a 3GPP network, the PEI will be an IMEI).

PEL - Privacy Exception List

The Privacy Exception List defines the of various types of privacy classes (i.e. operator related, personal etc.). Certain types of classes may require agreement between the service provider and the target mobile.

PEM - Privacy Enhanced Mail

PEM (Privacy Enhanced Mail) is based on RFC 1421 and defines a suite of protocols that provide privacy, authentication and integrity. This protocol is normally used to protect binary information when it has been translated into a printable format.

PENALTY_TIME

This specifies the time duration in GSM and UMTS for which the TEMPORARY_OFFSET is applied for a neighbouring cell.

PEP - Policy Enforcement Point

To support policy in IP networks a simple architecture based upon a policy server and policy aware network routers is deployed. The policy server is termed the PDF (Policy Decision Function) and uses a protocol such as COPS to communicate policy information to the PEF. Using policy information access, network resources etc are allocated to the network user.

PES - PSTN Emulation Subsystem

In the TISPAN specifications, the PES is designed to support the emulation of PSTN / ISDN type services for legacy terminals that are connected to the TISPAN network.

PF - Paging Frame

This is used in relation to DRX (Discontinuous Reception) in E-UTRA and identifies a radio frame which may contain one or multiple Paging Occasion(s). The paging frame is calculated using various parameters including a modulo version of the IMSI.

PF - Policy Function

PF is the generic title given to a policy element such as a PDF (Policy Decision Function) or PEF (Policy Enforcement Function).

PFC - Packet Flow Context

In GPRS Release 99, a SGSN (Serving GPRS Support Node) is able to provide the BSS (Base Station System) with information related to the ongoing user data transmission in terms of a BSS PFC. These are used to describe the QoS (Quality of Service) characteristics for data transmission per mobile and are identified in terms of their PFI (Packet Flow Identity). There are three predefined Packet Flow Contexts which are used for Best Effort, SMS (Short Message Service) transmission and Signalling which do not require any form of negotiation between the SGSN and the BSS.

PFD - Packet Flow Detection

A PFD is a means by which an ASP (Application Service Provider) related to Cellular IoT can push application or service detection information into the 5G network in order for its associated user plane traffic to be detected at the UPF and hence have the correct PCC enforcement applied.

PFDF - Packet Flow Description Function

Used within CIoT (Cellular Internet of Things) networks, the PFDF is a repository which stores PFD (Packet Flow Description) that can be managed and updated by third party service providers. For example, an IoT platform may require all its associated devices to send information to a new IoT Application Server and thus would provide it with an IP address, protocol and port number to use.

PFI - Packet Flow Identity

The Packet Flow Identifier is used to indicate a PFC (Packet Flow Context) associated with an LLC (Logical Link Control) – PDU (Protocol Data Unit). If the mobile does not support PFC or if the PFI is not known by the SGSN (Serving GPRS Support Node), then it will use the pre-defined PFI indicating best effort QoS (Quality of Service).

PFS - Perfect Forward Secrecy

PFS (Perfect Forward Secrecy), also known as public-key forward secrecy, works on the premise that no key used for the transfer of data may be used to derive any keys for future transmission.

PGP - Pretty Good Privacy

Pretty Good Privacy is a widely used public key encryption application that allows secure file and message exchange.

PGW-C - PDN Gateway Control plane function

The PGW-C controls the functionality performed by the assigned PGW-U when control and user plane separation is in place. When a subscriber establishes an EPS (Evolved Packet System) bearer to a given PDN, the PGW-C selects and controls the point of attachment to that PDN for the life of the EPS bearer (regardless of any mobility procedures). Responsibilities include resource management for bearer resources, bearer binding, subscriber IP address management and mobility support.

PGW-U - PDN Gateway User plane function

The PGW-U serves as the user data plane ingress and egress point to the EPC when control and user plane separation is in place. When a subscriber establishes an EPS (Evolved Packet System) bearer to a given PDN, the PGW-U under the control of the PGW-C serves as the point of attachment to that PDN for the life of the EPS bearer (regardless of any mobility procedures). Packet inspection is a key role of the PGW-U in order to ensure that data has the appropriate service level applied.

PHB - Per Hop Behaviour

This is the treatment that a DiffServ (Differentiated Services) router applies to an IP datagram containing a given DSCP (DiffServ Code Point) value.

PHICH - Physical Hybrid ARQ Indicator Channel

The E-UTRA PHICH (Physical Hybrid ARQ Indicator Channel) carries HARQ (Hybrid ARQ) ACK/NAK’s and is transmitted in terms of PHICH groups. A PHICH group consists of up to eight ACK/NACK processes and one PHICH group uses three REG s.

Photonics

Photonics is the technology of using light particles (photons) to carry information over fibres of pure glass.

PHS - Personal Handyphone System

PHS was developed in Japan in 1989 as a cordless telecommunication system operating within the band 1895MHz to 1918MHz. The aim was to provide cordless access to the PSTN and thus had similar operating characteristics to cellular systems.

Physical - Medium Access Control

The MAC protocol layer is present in the mobile and the NB/eNB in order to support the correct multiplexing/demultiplexing of signalling and user plane traffic onto the various transport channels of the air interface.

Physical Channel - Bluetooth

The Bluetooth physical channel is identified by a synchronized RF (Radio Frequency) hopping sequence in a piconet.

Physical Channels

The physical channel supports the physical media, usually in an encoded format. This may be pulses of light, a modulated voltage or radio waves. The physical channel is described in Layer 1 of the OSI (Open Standards Interconnection) model.

Physical Link

A Physical Link is the connection between devices.

PIA - Point in Association

GPRS State Models use PIA (Point In Association) to identify SGSN activities that are relevant to the CAMEL Service Environment. These points may be viewed as similar to the traditional PIC (Point In Call) found in systems.

PIC - Point In Call

The PIC identifies Call Control Function activities associated with one or more basic call/connection states which are of interest to IN service logic instances.

Pico Cell

A very small cell, from tens to hundreds of meters in size. Pico cells are optimized to provide high capacity.

Piconet

In the Bluetooth system, a piconet is created when two or more devices create a Master / Slave connection in an ad hoc fashion, an example being a cellular phone and a computer. Each piconet can have only one Master, one to seven active Slaves, and 0-255 Parked Slaves. All devices in the piconet use the same physical channel, this is defined by the master device.

PIFS - PCF Interframe Space

PIFS are found in IEEE 802.11 networks. When the radio link has been free of any traffic for a period greater than the PIFS, Stations operating in contention free mode may have immediate access to the medium. As such, PIFS has a shorter duration than DIFS (DCF Interframe Space) which is used in the contention based mode.

Pilot

Pilot Pilot bits are used to support channel estimation for coherent detection.

Pilot Beacon

This is found on a transmit only base station that broadcasts a Pilot Channel, a Sync Channel, optionally a Paging Channel or a Broadcast Control Channel, but not Forward Traffic Channels. The MS (Mobile Station) measures the pilot beacon to assist in CDMA (Code Division Multiple Access) hard handoffs and inter frequency idle mode handoffs.

Pilot Channel

This is an unmodulated , direct sequence spread spectrum signal transmitted by a CDMA (Code Division Multiple Access) BS (Base Station) or MS (Mobile Station). A pilot channel provides a phase reference for coherent demodulation in addition to providing a means for signal strength comparisons between Base Stations, which is used when determining when to handoff.

Pilot PN Chip

One bit or bit pair of a pilot PN (Pseudorandom Noise) sequence, or the time interval corresponding to it.

Pilot PN Sequence

A pair of modified maximum length PN (Pseudorandom Noise) sequences used to spread the quadrature components of a CDMA (Code Division Multiple Access) Channel.

Pilot PN Sequence Offset

This is the time offset of a Forward Pilot Channel from CDMA (Code Division Multiple Access) System time, as transmitted by the BS (Base Station), expressed modulo to the pilot period.

Pilot PN Sequence Offset Index

The pilot PN sequence offset is expressed in units of 64 PN (Pseudorandom Noise) chips of a Forward Pilot Channel , relative to the zero offset pilot PN sequence.

Pilot Strength

The ratio of pilot power to total power in the signal bandwidth of a CDMA (Code Division Multiple Access) Forward or Reverse Channel.

PIM - Protocol Independent Multicast

PIM is a routing protocol that is utilized in multicast IP transport networks. As such, PIM ensures that multicast traffic is only being sent to recipients that are interested in that traffic and also when traffic is sent, it takes the optimal path through the network.

PIN - Personal Identification Number

The Bluetooth Personal Identification Number is used to authenticate two devices that have not previously exchanged link key. By exchanging a PIN, the devices create a trusted relationship. The PIN is used in the pairing procedure to generate the initial link that is used for further identification.

PING - Packet Internet Groper

This is a utility programme which tests access to a device by sending a series of messages and measuring the replies.

Ping of Death

This is an attack that sends a larger than expected PING (Packet Internet Gopher). For example, an echo request packet with a packet size greater than 65,507. If the TCP/IP stack on the end machine is badly written, it will cause the machine to crash with a buffer overflow causing a DoS (Denial of Service) or in some instances, the ability to log onto the system.

Pitch

The fundamental frequency in speech caused by the periodic vibration of the human vocal cords.

PKCS - Public-Key Cryptography Standards

PKCS (Public-Key Cryptography Standards) are a list of specifications and framework documents issued by RSA Security.

PKCS 1 - Public Key Cryptography Standard 1

PKCS 1 (Public Key Cryptography Standard 1) is the standard used to define the use of RSA algorithms for encryption and digital certificates.

PKCS 10 - Public Key Cryptography Standard 10

PKCS 10 (Public Key Cryptography Standard 10) defines the process for certification requests.

PKCS 11 - Public Key Cryptography Standard 11

PKCS 11 (Public Key Cryptography Standard 11) defines the standard for the interface between smart cards and crypto accelerators.

PKCS 12 - Public Key Cryptography Standard 12

PKCS 12 (Public Key Cryptography Standard 12) defines the standard for the storage of keys and certificates.

PKCS 15 - Public Key Cryptography Standard 15

PKCS 15 (Public Key Cryptography Standard 15) defines the standard for the storage of keys on smart cards.

PKCS 7 - Public Key Cryptography Standard 7

PKCS 7 (Public Key Cryptography Standard 7) defines the syntax for data that may have encryption applied to it.

PKCS 8 - Public Key Cryptography Standard 8

PKCS 8 (Public Key Cryptography Standard 8) defines the syntax for private keys and private key information.

PKE - Public Key Encryption

Public Key Encryption is the process of utilizing Public/Private key pairs in order to protect data across the public Internet.

PKI - Public-Key Infrastructure

PKI (Public-Key Infrastructure) comprises all the elements required to implement public key encryption. These include the key pairs, certification authorities, certificate repositories and all the other software and hardware components.

PKIX - Public Key Infrastructure (X.509)

PKIX (Public Key Infrastructure ( X.509)) defines the framework for the many processes and collaborations being used to support public key technology on the Internet. The framework has been coordinated by the IETF (Internet Engineering Task Force) working group known as PKIX.

Plaintext

Plaintext is text which has not been encrypted.

PLC - Power Line Communication

This is a communication technology which enables electrical wiring to be used to carry both electricity and communication data around the home or office. Standards such as HomePlug utilize PLC technology to network their IoT (Internet of Things) devices.

PLL - Phase Lock Loop

This is a technique for recovering the clock in transmitted data and is often performed by an integrated circuit.

PLMN - Public Land Mobile Network

A Public Land Mobile Network is a generic name for all mobile wireless networks that use land based radio transmitters or base stations.

PMA or PM_ADDR - Parked Member Address

In a piconet, each slave in the park mode can be identified by a BD_ADDR ( Bluetooth Device Address) or a dedicated PM_ADDR (Parked Member Address). The PM_ADDR is an 8bit member address allocated by the master to separate parked devices. Once a slave is in the active mode, it will lose the PM_ADDR and be assigned an AM_ADDR (Active Member Address). The PM_ADDR is set to eight zeros for the parked slaves who only use their BD_ADDR to communicate.

PMCH - Physical Multicast Channel

This is a E-UTRA physical channel used to support MBMS (Multimedia Broadcast Multicast Service). It carries the MCH (Multicast Channel) Transport Channel.

PMI - Precoding Matrix Indicator

This is a E-UTRA parameter related to MIMO feedback for some of the E-UTRA transmission modes. The precoding feedback is used for channel dependent codebook based precoding and relies on UEs reporting the desired PMI (Precoding Matrix Indicator).

PMIP - Proxy Mobile IP

Proxy MIP introduces a MAG (Mobility Access Gateway) into the Mobile IP architecture which interacts with the HA , termed a LMA (Local Mobility Anchor)in Proxy MIP parlance, on behalf of the Mobile Node. With PMIP, the use of MIP in the network is transparent to the mobile device.

PMK - Pairwise Master Key

A PMK is a cryptographic key which is used to derive lower level keys. Networks based on technologies such as UMTS and WiMAX use PMK as part of their relative security procedures.

PMR - Private Mobile Radio

Private Mobile Radio is the term used to describe radio communication systems used by small to medium sized groups of users.

PN - N-PDU Number

This is a GTP (GPRS Tunnelling Protocol) based flag that indicates the presence of a meaningful value of the N-PDU Number field.

PN - Pseudorandom Noise

A bit stream that when analyzed out of context appears to be random. It is sometimes referred to as Pseudonoise.

PN Chip

One bit in a PN (Pseudorandom Noise) sequence, or the time duration of such a bit. It corresponds to the smallest modulation interval in a CDMA (Code Division Multiple Access) system.

PNCH - Packet Notification Channel

The Packet Notification Channel is used to send Point to Multipoint multicast notification information to a group of MS (Mobile Station) prior to Point to Multipoint multicast packet transfer.

PNF - Physical Network Function

Within the NFV (Network Functions Virtualization) framework, a PNF is a physical network node which has not undergone virtualization. Both PNFs and VNFs (Virtualized Network Functions) can be used to form an overall Network Service.

PNP - Private Numbering Plan

A Private Numbering Plan defines the format of telephone numbers to be used within a private telephone system. The PNP number normally consist of at least 3 digits, excluding 112.

PoA - Point of Attachment

The PoA can be defined as the point at which the user breaks out of their link layer access network and onto the packet data network eg the Internet, IMS etc.

POC - Push to talk Over Cellular

POC which is also termed PTT (Push To Talk) uses the GPRS network to send packetized speech between participants of a POC session. The process as far as the user is concerned can be likened to CB Radio in which users share a communication channel, by pressing the button to talk, and then releasing it to allow other participants to speak. PoC is also available as an IMS managed service, with PoC sessions established using SIP. In this case, the IP-CAN is not necessarily GPRS.

POC Client

The POC Client is an application supported on the operating system of the mobile device and terminates the POC signalling both for registration and other procedures within the network Core such as authentication. It also interacts, through POC signalling, with the POC Server. This involves setting up POC sessions with individuals or groups as well as answering invitations by other POC users.

POC Server

The POC Server provides the controlling function within the POC architecture. It is, in effect, an AS (Application Server) supporting the call control function.

Point to Multipoint

A generic term used to identify communications from a single source to multiple destinations.

Point-to-Point

A value of the service attribute communication configuration, which denotes that the communication involves only two network terminations.

PON - Passive Optical Networks

PON (Passive Optical Network) are optical fibre based networks which employ a point to multipoint network architecture. Passive, unpowered optical splitters are utilized to allow one fibre, often connected to the Local Exchange/Central Office, to serve a number of subscribers (typically 32 subscribers but can be as many as 128). PON technology emerged in the early 1990s and recently, PON have been deployed in support of IP convergence in many existing and green field networks. Key components of PON architecture include the OLT and ONU. 

POP - Point Of Presence

A Point of Presence is a local access point into a network such as the Internet.

Port Number

Port Numbers may be physical or logical. The most common use of the term port is in IP based application protocols, and is used to describe the SAP (Service Access Point) through which the transport protocols, such as TCP (Transport Control Protocol) or UDP (User Datagram Protocol), pass information to the higher layers, and vice versa. The port numbers that are associated with the higher layer application protocol are assigned through the IANA and are classified as follows: Well Known – 0 to 1023, Registered – 1024 to 49151, Dynamic – 49152 to 65535.

POTS - Plain Old Telephone Service

A very general term used to describe an ordinary voice telephone service.

Power Control Bit

The Power Control Bit is sent on the Forward Power Control Subchannel or Reverse Power Control Subchannel to signal the MS (Mobile Station) or base station to increase or decrease its transmit power.

Power Down Registration

An autonomous registration method in which the MS (Mobile Station) registers with the network on power down.

Power Up Registration

An autonomous registration method in which the MS (Mobile Station) registers with the network on power up.

PPCH - Packet Paging Channel

The Packet Paging Channel is used to page a MS (Mobile Station) prior to downlink packet transfer. The PPCH uses paging groups in order to allow the mobile to utilize DRX (Discontinuous Reception) mode. It can be used for paging both circuit switched and packet data services.

PPP - Point to Point Protocol

The Point to Point Protocol was designed to provide router to router and host to network connections over synchronous and asynchronous circuits. In addition, PPP has a built in security mechanism.

PPTP - Point

Point-to-Point Tunnelling Protocol is a Layer 2 protocol that encapsulates PPP (Point to Point Protocol) frames in IP datagrams for transmission, typically over the Internet. PPTP uses a TCP (Transmission Control Protocol) connection for tunnel maintenance and a modified version of GRE (Generic Routing Encapsulation) to encapsulate PPP data frames.

PQI - PC5 QoS Identifier

PQI is a special 5QI used as a reference to PC5 QoS characteristics. QoS handling for V2X communication over PC5 is based upon the 5QI (5G QoS Indicator) format, with an additional parameter covering range being added.

PRACH - Packet Random Access Channel

The Packet Random Access Channel is used by a GPRS enabled MS (Mobile Station) to initiate uplink transfer of user data or signalling information.

PRACH - Physical Random Access Channel

The Random Access procedure is used in various scenarios, including initial access, handover, or re-establishment. Like other 3GPP systems the random access procedure provides a method for contention and non-contention based access. The PRACH (Physical Random Access Channel) includes RA (Random Access) preambles generated from Zadoff-Chu sequences.

PRACK - Provisional Response Acknowledgement

This is a SIP method which will provide information that confirms the receipt of an earlier provisional response message.

PRAF - Positioning Radio Assistance Function

The Positioning Radio Assistance Function provides additional support for the PRCF (Positioning Radio Coordination Function) when radio coordination is distributed among multiple network elements. A particular function of the PRAF for network based position methods is to induce positioning signals from the target mobile. For mobile based and mobile assisted position methods, the PRAF can induce position signals from the network or from some other external reference source.

PRB - Physical Resource Block

A E-UTRA PRB (Physical Resource Block) is defined as consisting of 12 consecutive subcarriers for one slot (0.5 ms). A PRB is the smallest element of resource allocation assigned by the eNB scheduler.

PRC - Primary Reference Clock

The PRC is the term given to the master timing source within a network.

PRCF - Positioning Radio Coordination Function

The Positioning Radio Control Function manages the positioning of a mobile through the overall coordination and scheduling of resources to perform positioning measurements. This function interfaces with the PSMF (Positioning Signal Measurement Function) and PCF (Positioning Calculation Function) and possibly with a PRAF (Positioning Radio Assistance Function). The PRCF determines the positioning method to be used based on the QoS (Quality of Service), the capabilities of the network and the mobile’s location capabilities. 

Precedence

The term precedence indicates the relative priority of maintaining the service.

Presence - Presence Application Server

A Presence Application Server provides the ability for a user to inform any interested parties as to the current status of the user. This can include availability, portrait icon, favourite link, timestamp and location details. Authorisation is central to enabling multiple parties to share social presence information and in order to assist with this Social Presence service and architecture is based upon the OMA Presence specification – OMA Presence SIMPLE Specification 1.1.

Presence Server

Presence is a service which can be applied as a supplement to many other services, such as voice, gaming and IM. Presence Servers collate presence information from presence clients and subsequently distribute this information to interested parties. SIP provides a presence architecture through use of the SUBSCRIBE, NOTIFY and PUBLISH methods.

PRI - Primary Rate Interface

A Primary Rate Interface is a ISDN (Integrated Services Digital Network) term describing either an E1 circuit in Europe or a T1 circuit in North America. These are comprised of 30 traffic channels and two signalling channels (E1, 30B+2D – 2.048Mbps) or 23 traffic channels and one signalling channels (T1, 23B+D – 1.544Mbps) respectively.

Primary CDMA Channel

Primary CDMA Channel This is a preassigned channel in a CDMA (Code Division Multiple Access) cellular system used by the MS (Mobile Station) for initial acquisition.

Primitive

A generic term for the transfer of data and control information between two adjacent layers and sublayers within a protocol stack. It is conventionally represented as a function invocation, with the data and control information passed as parameters.

Private Key

A Private Key is the secret component of a pair of cryptographic keys (Public / Private Key) used for cryptography.

PRN - Provide Roaming Number

The MAP PRN message is sent from the HLR to the MSC serving a mobile for which an incoming call is being processed. The message triggers the MSC to forward an MSRN (Mobile Station Roaming Number) to the GMSC via the HLR. This MSRN is used by the GMSC to route the call to the correct MSC.

Proactive SIM

A SIM (Subscriber Identity Module), which is capable of issuing commands to the handset/terminal.

Propagation Delay

This is the time taken for a signal to travel over a given distance in a specified medium.

ProSe - Proximity-based services

ProSe is an enabling technology for LTE for Public Safety. ProSe features consist of ProSe discovery (direct or EPC-level) and ProSe Direct Communication (using E-UTRAN or WLAN direct). With respect to ProSe Discovery, this identifies that ProSe-enabled LTE mobiles are in proximity to one another. ProSe Direct Communication enables establishment of communication paths between two or more ProSe-enabled UEs that are in direct communication range. The ProSe Direct Communication path could use E-UTRAN or WLAN.

Protection Switching

This is a facility enabling the recovery from a failure by switching to another transmission path. An example of protection switching is 1+1 which provides a standby path all of the time. N+M protection switching enables N paths to be protected by M standbys.

Protocol

A Protocol can be described as a set of rules and conventions that govern how devices on a network exchange information.

Protocol Stack

Conceptual model of the layered architecture of communication protocols in which layers within a station are represented in hierarchical order. Each layer in the protocol stack is defined in generic terms describing functionality and mode of operation. Examples of protocol stacks include the OSI (Open System Interconnection) model and the TCP/IP protocol stack.

PS - Packet Switched

In a packet switched network, data may be transferred by dividing it into small blocks or pieces known as packets. Each packet contains information in its header to allow it to be routed by packet switches across the network. This is a more efficient means of transferring data. An example of a packet switched network is the Internet.

PS-Code - Pseudo Random Code

A signal with random noise like properties. It contains a complicated repeated pattern of 1’s and 0’s.

 PSA - PDU Session Anchor

PSA is the term given to the UPF (User Plane Function) which terminates the N6 interface of a PDU session within a 5G core network.

PSAP - Public Safety Answering Point

The PSAP is the physical location(s) within the PSTN at which emergency services call handlers will take emergency calls from individuals in distress. Emergency services can be sent to the individual’s geographic location based on information provided verbally or through automated means based on their access network. The latest generation of PSAPs support packet based connectivity to service frameworks such as the IMS (IP Multimedia Subsystem), allowing users of an IMS to make emergency calls without having to break the call out to the PSTN.

PSI - Packet System Information

In GPRS Packet System Information messages are broadcast on the PBCCH (Packet Broadcast Control Channel) and inform terminals of the GPRS parameters within the cell.

PSI - Provide Subscriber Information

This message is used as part of the CAMEL ATI (Any Time Interrogation) process. It is sent from the HLR to the serving MSC in order to retrieve subscriber state and location information.

PSI - Public Service Identity

With respect to the 3GPP IMS (IP Multimedia Subsystem), PSI are used to identify services which are hosted by an AS (Application Server), as opposed to Public User Identities, which identify an IMS subscriber. PSI can also be used to identify groups of IMS subscribers.

PSK - Phase Shift Keying

Phase Shift Keying is a technique enabling digital information to be carried over an analogue carrier such as a radio link. The process causes the phase of the carrier wave to be manipulated in order to signify either a logical 0 or 1 There are many variations of PSK allowing greater data transfer rates to be achieved.

PSM - Power Save Mode

Introduced in Release 13 of the 3GPP specifications, PSM enables mobile / devices to reduce power consumption by effectively powering off for long periods of time. However, during such periods, the mobile / device remains attached to the network and maintains any PDP (Packet Data Protocol) Contexts or EPS (Evolved Packet System) bearers.

PSMF - Positioning Signal Measurement Function

The Positioning Signal Measurement Function is responsible for gathering uplink or downlink radio signal measurements in order to calculate a mobile’s position. These measurements can be positioning related or ancillary.

PSS - Primary Synchronization Signal

The PSS (Primary Synchronization Signal) provides downlink synchronization information for the UE. The signal is based on one of three Zadoff-Chu sequences that in effect generates a pseudo noise pattern to enable the UE to discriminate between synchronization signals on adjacent cells.

PSTN - Public Switched Telephone Network

This is a general term referring to a public telephony network which is based on the switching of TDM circuits in order to convey both signalling and voice.

PTCCH - Packet Timing Control Channel

The Packet Timing Control Channel is used in GPRS to ensure that the correct timing advance is maintained for each MS (Mobile Station). On the uplink, the PTCCH is used by a mobile station to send an Access Burst and on the downlink, the mobile station will receive a TAI (Timing Advance Index) value.

PTI - Procedure Transaction Identity

An identity which is dynamically allocated by the UE for tracking and correlating UE requested ESM (EPS Session Management) procedures. The PTI is released when the procedure is completed.

PTP - Precision Time Protocol

A protocol based mechanism which provides timing and synchronization reference over a packet switched transport network. Standardized as IEEE 1588v2.

PTT - Push to Talk

PTT is a walkie-talkie style service that uses the services of cellular network technology such as GSM (Global System for Mobile communications), GPRS (General Packet Radio Service) and 3G (Third Generation) systems such as UMTS (Universal Mobile telecommunications System) and CDMA2000 It was first offered as a service over ten years ago by Nextel, a North American carrier.

Public Key

A Public Key is the publicly disclosable component of a pair of cryptographic keys (Public / Private Key) used for cryptography.

PUCCH - Physical Uplink Control Channel

The E-UTRA PUCCH (Physical Uplink Control Channel) carries UCI (Uplink Channel Information) such as ACK/NAK’s in response to downlink transmission, as well as CQI (Channel Quality Indicator) reports. It also carries scheduling request indicators and MIMO codeword feedback.

PUF - Power Up Function

A method by which a MS (Mobile Station) increases its output power to support location services.

PUSCH - Physical Uplink Shared Channel

The E-UTRA PUSCH (Physical Uplink Shared Channel) is the main uplink channel and is used to carry the UL-SCH (Uplink Shared Channel) transport channel. It carries both signalling and user data, in addition to UCI.

PVC - Permanent Virtual Circuit

A Permanent Virtual Circuit is a permanently established logical connection between two devices on a packet switched network. Examples of PVC can be found on ATM (Asynchronous Transfer Mode) and Frame Relay networks. The advantage of a PVC over a SVC (Switched Virtual Circuit) is the saving of bandwidth associated with circuit establishment and tear down.

PWE3 - Pseudowire Emulation Edge to Edge

PWE3, also termed Pseudowires, are used extensively in IP-RAN scenarios whereby cell sites based on TDM or ATM transmission are linked to the core network using IP or MPLS based transport links. These links, although fundamentally packet based, can carry the native E1 frames or ATM cells, hence negating the requirement to upgrade the cell site device yet still benefitting from IP/MPLS transport in the RAN.

PZID - Packet Zone Identification

The Packet Zone Identification is a unique number which identifies the PCF (Packet Control Function) coverage area within a particular geographic area.

QAM - Quadrature Amplitude Modulation

Modulation technique using two amplitude modulated RF (Radio Frequency) carriers that are out of phase by 90 degrees. Information transfer is achieved using a mixture of phase and amplitude changes. Since noise also appears as amplitude variations QAM is prone to interference.

QAP - Quality Access Point

The term QAP is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancement. It defines a Quality of Service aware Access Point.

QBSS - Quality Basic Service Set

The term QBSS is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancement. It defines a Basic Service Set supporting a QAP and a number of QSTA.

QCI - QoS Class Identifier

In LTE , the QoS Class Identifier is used as a reference to access node-specific parameters that control bearer level packet forwarding treatment (e.g. scheduling weights, admission thresholds, queue management thresholds, link layer protocol configuration, etc.) which have been pre-configured by the operator owning the eNB.

QDU - Quantization Distortion Unit

A particular quantization process will generate quantization noise that affects the quality of the process. Each quantization process is given a Quantization Distortion unit value to indicate the amount of quantization noise generated. PCM (Pulse Code Modulation) generates 1 quantization distortion unit (1qdu).

Qhcs

This specifies the UMTS quality threshold levels when applying prioritized hierarchical cell reselection.

Qhyst

This specifies the UMTS hysteresis value (Qhyst). It is used for FDD (Frequency Division Duplex) cells if the quality measure for cell selection and reselection is set to CPICH (Common Pilot Channel) Ec/No.

QIB - Quality Indicator Bit

The Quality Indicator Bit indicates signal quality on the Forward Dedicated Control Channel.

Qmap

Quality of the neighbouring (Qmap, n) or serving (Qmap, s) cell, after the mapping function is applied.

QoE - Quality of Experience

Where QoS is an indication of network performance, QoE is a measure of how network performance effects the end service and hence how the subscriber experiences that service. In some cases, a relatively significant QoS failure in the network may not have a perceivable effect on QoS. Conversely, in certain scenarios just a single dropped packet could detrimentally effect QoE eg dropping a packet carrying an i-frame as part of an IPTV service.

Qoffset

Qoffset This specifies the offset between the two cells. It is used for FDD (Frequency Division Duplex) cells in case the quality measure for cell selection and re-selection is set to CPICH (Common Pilot Channel) Ec/No.

QoS - Quality of Service

The performance of a communications channel or system is usually expressed in terms of QoS (Quality of Service). Depending upon the communication system, QoS may relate to service performance, SNR (Signal to Noise Ratio), BER (Bit Error Ratio), maximum and mean throughput rate, reliability, priority and other factors specific to each service.

QoS Negotiated

The QoS provided by the SGSN (Serving GPRS Support Node), this will be dependant on the QoS Requested and the QoS Subscribed.

QoS Profile

The QoS (Quality of Service) profile in a GPRS system comprises a number of QoS parameters. A GPRS QoS profile is associated with each QoS Session. The GPRS QoS profile defines the performance expectations for the bearer network.

QoS Requested

The term used to identify the QoS (Quality of Service) that the user is requesting for this PDP (Packet Data Protocol) context. The mobile should receive back a QoS Negotiated which will depend on the QoS Subscribed and the current conditions in the network.

QoS Session

Within a GPRS system the QoS (Quality of Service) session indicates the lifetime of a PDP (Packet Data Protocol) context. The period between the opening and closing of a PDP context whose characteristics are defined by a QoS Profile. Multiple QoS sessions may exist, each with a different GPRS QoS profile.

QoS Subscribed

The GPRS term used to identify the QoS (Quality of Service) that the user has subscribed to, this is stored in the HLR (Home Location Register) and current SGSN (Serving GPRS Support Node).

QPCH - Quick Paging Channel

This channel is utilized by a BS (Base Station) to inform a slotted mode MS (Mobile Station) whether to monitor the PCH (Paging Channel) or the FCCCH (Forward Common Control Channel).

QPSK - Quadrature Phase Shift Keying

Phase shift keying in which four different phase angles are used. Sometimes called quadriphase or quaternary phase shift keying.

Qqualmeas

Qqualmeas Measured cell quality value. The quality of the received signal expressed in CPICH (Common Pilot Channel) Ec/N0 dB (decibel) for FDD (Frequency Division Duplex) cells.

Qqualmin

Qqualmin Minimum required quality level in the cell, in dB (Decibels).

Qrxlevmin

This specifies the minimum required RX (Receiver) level in the cell in dBm (decibels with reference to 1mW).

QSIG - Q reference point Signalling System

The Q reference point Signalling System replaces traditional analogue signalling between a PABX (Private Automatic Branch Exchange) on one site and a PABX on another site.

QSTA - Quality Station

The term QSTA is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancement. It defines a Quality of Service aware Station (Non Access Point Station).

Quantization

A process in which an analogue signal is sampled and converted into a discrete value. PCM (Pulse Code Modulation) uses quantization.

Quantization level

In the quantization process, the discrete value assigned to a particular sample of the analogue signal being quantized.

Quantization noise

Noise caused by the error of approximation in quantization. The level of quantizing noise is dependent on the particular quantization process used and the characteristics of the quantized signal.

Quick Paging

This is an optimal feature enabling a MS (Mobile Station) to further conserve its battery power.

Quick Paging Channel Slot

An interval on the QPCH (Quick Paging Channel) lasting 80ms.

Quick Repeats

Quick Repeats Identifies additional transmissions of a message within a short interval; this is used to increase the probability of successful reception.

R - Reselection

The process made by a mobile whilst in the UMTS idle state or one of the paging states. The term R(s) is used for the calculation on the serving cell, whilst R(n) is for calculations on the neighbouring cell.

R Reference Point

The R Reference Point lies between non ISDN equipment and a TA (Terminal Adapter).

r-csch - reverse-common signaling logical channel

A logical channel that carries higher layer signaling traffic from the user to the BS (Base Station) over a common physical channel.

r-dsch - reverse-dedicated signaling logical channel

A logical channel that carries higher layer signaling traffic from the BS (Base Station) to the user over a common physical channel.

R-UIM - Removable User Identity Module

The R-UIM is a removable variant of a UIM (User Identity Module) which can be physically removed from a ME (Mobile Equipment) and inserted into another ME. This removal into another ME will be dependant on compatible ME/UIM interfaces.

R2MFC - R2 Multi Frequency Compelled

CCS (Common Channel Signalling) system that allows the equipment units at the exchanges to send and receive digits.

RA - Rate Adaptation

The Rate Adaptation process takes place when a slow device is connected to an ISDN (Integrated Services Digital Network). Rate Adaptation is required when the equipment at one end is a TA (Terminal Adapter) connected to a synchronous or asynchronous device running at a speed lower than 64Kbps. The two main ITU-T (International Telecommunications Union-Telecommunication Standardization Sector) Rate Adaptation standards are V.110 and V.120.

RA - Registration Authority

An RA (Registration Authority) may be used in PKE (Public Key Encryption) to support the distribution and management of keys and tokens along with other responsibilities such as certificate revocation reporting.

RA - Routing Area

The SGSN (Serving GPRS Support Node) in a GPRS system will control one or more RA (Routing Area). It is the responsibility of the mobile to keep the SGSN informed as to its current RA. Routing Areas can be made up on one or more cells. Each Routing Area is given a RAI (Routing Area Identification).

RA-RNTI - Random Access – Radio Network Temporary Identifier

As part of the E-UTRA access procedure the UE will probe the system with Random Access Preambles. On receiving these the eNB generates a RA-RNTI to effectively schedule the response.

RAA - Re-Authorization Answer

The RAA is a Diameter credit control command. In LTE, the message is sent by the PCEF to the PCRF across the Gx interface in response to the Re-Authorization Request command as a confirmation of receipt.

RAB - Radio Access Bearer

Term used in UMTS to identify the service the AS (Access Stratum) provides to the NAS (Non Access Stratum) for transfer of user data between the UE (User Equipment) and the CN (Core Network).

RAC - Routing Area Code

Routing Area Code is a fixed length of 1 octet and identifies a routing area within a location area. The RAC is part of the RAI (Routing Area Identity).

RACH - Random Access Channel

The channel used for initial access into a system. The RACH function is different depending on the technology of the system. The term RACH applies to cdmaOne, GSM, UMTS, TETRA, CDMA2000 LTE and other telecommunication systems.

RAck - Response Acknowledged

RAck is a SIP (Session Initiation Protocol) header field which is used in support of the PRACK method.

RACS - Resource and Admission Control Subsystem

The RACS is an integral part of the TISPAN architecture, designed to allow user devices to request and reserve resources in the access network, essentially providing subscribers with the correct QoS for the service they are attempting to initiate.

Radio Access Mode

Identifies the access mode for a cell. This usually indicates FDD (Frequency Division Duplex) or TDD (Time Division Duplex) mode of access.

Radio Configuration Class

A term used to identify a group of RC (Radio Configuration). The RC (Radio Configuration) for forward and reverse traffic channels, are divided into three classes.

Radio frame

Depending on the technology, a radio frame is a numbered time interval used for data transmission on the radio physical channel.

Radio Interface

The radio interface is the wireless interface between two points. This term encompasses all the functionality required to maintain such interfaces. In cellular systems the interface between the terminal and the base station is referred to as the radio interface or air interface.

Radio link

Radio link In a UMTS system, the term radio link is a logical association between single UE (User Equipment) and a single UTRAN (UMTS Terrestrial Radio Access Network) access point. Its physical realization comprises one or more radio bearer transmissions. It is possible for a UMTS mobile to have many radio links established, when this occurs the mobile is said to be in a soft handover.

Radio link addition

The procedure in UMTS where a new radio link is added to the active set.

Radio link removal

The procedure in UMTS where a radio link is removed from the active set.

Radio Spectrum

The range of frequencies used, for example, for broadcasting radio, PMR (Private Mobile Radio), terrestrial television, cellular mobile networks and satellite television. Usable frequency ranges from about 100KHz to about 500GHz.

RADIUS - Remote Authentication Dial-In User Service

Remote Authentication Dial-In User Service is a system of distributed security that secures remote access to networks and network services against unauthorized access. RADIUS includes the authentication server which is installed on a central computer within the network core and the client protocols used to access the server. RADIUS is designed to simplify the security process by separating security technology from communications technology. RADIUS servers are deployed extensively in support of DSL services and mobile broadband architectures, although there are many more instances of RADIUS usage for AAA.

RAF - Repository Access Function

The RAF is used to interwork the standardized XML based GUP (Generic User Profile) Server interface to the GUP data repositories, as specified by the 3GPP (3rd Generation Partnership Project).

RAI - Routing Area Identification

The Routing Area Identification is composed of the LAC (Location Area Code) and the RAC (Routing Area Code). It is used for paging and registration purposes.

RAM - Random Access Memory

Random Access Memory is the place in a computer where the operating system, application programs, and data currently in use are kept so that they can be quickly reached by the computer’s processor. Data in RAM stays there only as long as your computer is running. Turning off the computer loses the data in the RAM.

Rake Receiver

The rake receiver is a technique which uses several baseband correlators to individually process multipath signal components. The outputs from the different correlators are combined to achieve improved reliability and performance.

RAN - Radio Access Network

The Radio Access Network performs the radio functionality of the network, as well as providing the connection to the CN (Core Network). The RAN typically includes a controller ( RNC (Radio Network Controller) in 3GPP (Third Generation Partnership Project) and BSC (Base Station Controller) in 3GPP2 (Third Generation Partnership Project 2)) and several transmitter/receivers ( Node B in 3GPP, BTS (Base Transceiver Station) in 3GPP2).

RANAP - Radio Access Network Application Part

RANAP operates over the Iu-PS interface and provides two main functions; the support of AS (Access Stratum) signalling between the RNC and the SGSN and the encapsulation of NAS (Non Access Stratum) signalling passing between the mobile and the core network. With respect to AS signalling, RANAP supports procedures such as RAB (Radio Access Bearer) assignment and management, relocation, location reporting, paging and security management. RANAP uses the services of SCCP which in turn resides on either IP or ATM (Asynchronous Transfer Mode).

RAND - Random Number

A number selected from a known set of numbers in such a way that each number in the set has the same probability of occurrence. This is typically used in the authentication and ciphering process.

RANDBS - Base Station Random Variable

The RANDBS is a 32bit random number generated by the MS (Mobile Station) for authenticating BS (Base Station) orders to update the SSD (Shared Secret Data).

RANDC - Random Challenge

A MS (Mobile Station) parameter used in conjunction with the SSD (Shared Secret Data) and other parameters, enabling validation of calls and registrations.

RANDU - Unique Random Variable

A 24bit random number generated by the BS (Base Station)when carrying out the Unique Challenge-Response procedure.

RAPID - Random Access Preamble Identifier

This is used by the E-UTRA MAC layer and relates to the 6bit access preamble identifier which was initially used by a UE accessing the eNB on the PRACH. Effectively it forms part of the contention resolution procedure.

RAR - Random Access Response

This is used by the E-UTRA MAC layer. It contains the TA (Timing Alignment) information, initial UL grant and assignment of a Temporary C-RNTI to the UE associated with the RAPID (Random Access Preamble Identifier).

RAR - Re-Authorization Request

The RAR is a Diameter credit control command. In LTE, the message is sent by the PCRF to the PCEF across the Gx interface in order to provision PCC/QoS rules and event triggers using a push procedure. An example would be a network initiated dedicated EPS bearer establishment, whereby the receipt of this message would trigger the appropriate GTPv2-C message to be sent to the PDN-GW and the S-GW.

RARP - Reverse Address Resolution Protocol

Reverse Address Resolution Protocol is a protocol by which a physical machine in a LAN (Local Area Network) can request to learn its IP address from a gateway server’s ARP (Address Resolution Protocol) table or cache. When a new machine is set up, its RARP client program requests from the RARP server on the router to be sent its IP address. Assuming that an entry has been set up in the router table, the RARP server will return the IP address to the machine which can store it for future use.

RAT - Radio Access Technology

This indicates the type of radio technology to access the CN (Core Network). Example technologies being UTRA (UMTS Terrestrial Radio Access), CDMA2000, WiFi, GERAN (GSM EDGE Radio Access Network), LTE (Long Term Evolution) etc.

Rate centre

The geographic area used by local exchange carriers to set rate boundaries for billing and for issuing phone numbers.

Rate matching

This process is carried out so that the block size matches the radio frame(s). It will either repeat bits to increase the rate or puncture bits to decrease the rate.

RAU - Routing Area Update

A GPRS mobile will perform a Routing Area Update in the Ready and Standby state. The RAU is triggered when the mobile crosses a RA (Routing Area) boundary, or periodically. The time interval being set by the network. A RAU is also performed when the mobile moves from the Idle to the Standby state. This will typically happen when the mobile is powered on.

Rayleigh Fading

In electromagnetic wave propagation, phase interference fading caused by multipath effects.

RB - Radio Bearer

The service provided by the Layer 2 for the transfer of user data between UE (User Equipment) and UTRAN (UMTS Terrestrial Radio Access Network).

RB - Resource Block

In LTE a RB or PRB ( Physical Resource Block) is defined as consisting of 12 consecutive subcarriers for one slot (0.5 ms). A PRB is the smallest element of resource allocation assigned by the eNB scheduler.

RBG - Resource Block Group

This is a term used in the E-UTRA when the Distributed Virtual Resource Block concept is used. It effectively is part of the distribution/allocation method

RBOC - Regional Bell Operating Companies

The term RBOC (Regional Bell Operating Company) describes one of the U.S.regional telephone companies which were created as a result of the break-up of ATT/Bell Systems.

RBSN - Reduced Block Sequence Number

In GPRS each downlink RLC/MAC (Radio Link Control / Medium Access Control) control block contains a Reduced Block Sequence Number bit. At the time that an in sequence RLC / MAC control block is designated for transmission, the value of RBSN is set equal to the value of the control send state variable.

RC - Radio Configuration

The term Radio Configuration identifies a set of forward and reverse traffic channel transmission formats. At the physical layer these are characterized by the transmission rates, modulation characteristics, spreading rate, etc.

RC4

RC4 is a proprietary cipher algorithm which was developed and licensed by RSA Security Inc. The algorithm is used in many technologies including the IEEE 802.11 b WEP (Wired Equivalent Privacy).

RC5

RC5 is a symmetric block cipher designed by RSA Security Inc in 1994. RC5 uses a block size of between 32bits and 128bits and a key length of between 0bits and 2040bits.

RC6

RC6 is a symmetric block cipher based on RC5 and was selected as one of the candidates for the AES (Advanced Encryption Standard). It was designed by Rivest, Robshaw, Sidney, and Yin of RSA Security Inc. The block size, the key size, and the number of rounds are variable; the upper limit on the key size is 2040bits.

RCAF - RAN Congestion Awareness Function

The RCAF is a network element which monitors congestion in the E-UTRAN and UTRAN. The RCAF will collect information related to user plane congestion for an eNB or E-UTRAN cell, and will then liaise with the MME (Mobility Management Entity) to determine which users served by the eNB/cell are being affected. In turn, the RCAF can provide this information to the PCRF (Policy and Charging Rules Function), triggering a policy decision to alleviate the congestion.

RCF - Radio Control Function

An IN (Intelligent Network) functional entity providing access to users/terminals. It provides the network call related call unrelated and radio link functions.

RCS - Rich Communication Services

A GSMA initiative which aims to standardize the next generation of IP based services in order to support worldwide cross network interoperability. Services are largely IMS based and include voice and video calling, enhanced messaging services, social presence, file/media transfer and geolocation, amongst others.

RD - Route Distinguisher

A BGP speaker can only advertise one route per IP prefix and can therefore completely omit a route to a VPN if its addressing overlaps a different VPN, creating a one or the other scenario. The solution to this problem is to add an 8-byte RD (Route Distinguisher) to the IPv4 address, creating a unique 12byte VPN-IPv4 address.

Ready State

This is a GPRS state that indicates the mobile has received or is waiting for resources from the network. In this state the mobile is carrying out cell selection and cell reselection calculations to determine the best cell. The mobile will carry out cell and routing area updates when necessary.

Reassociation

The term Reassociation is found within an IEEE 802.11 network and identifies the service used when a Station moves from one AP (Access Point) to another. In such cases, the Association is transferred between the two AP with the Station Reassociating with the second.

Received Signal Code Power

Given only signal power is received, the average power of the received signal after despreading and combining.

Received Total Wide Band Power

The received wide band power, including noise generated in the receiver, within the bandwidth defined by the pulse shaping filter. In case of receiver diversity the reported value shall be a linear average of the power in the diversity branches. The reference point for the received total wide band power measurement shall be the output of the pulse shaping filter in the receiver.

Receiver Antenna Gain

The maximum gain of the receiver antenna in the horizontal plane, specified as dBi (dB relative to an isotropic radiator).

Receiver Noise Figure

Receiver noise figure in dB (decibel) is the noise figure of the receiving system referenced to the receiver input.

Receiver Sensitivity - Receiver Sensitivity (dBm)

The Receiver Sensitivity is the signal level needed at the receiver input that just satisfies the required Eb/(No+Io).

Recipient network

Term linked to number portability. The network which receives the number in the porting process. This network becomes the subscription network when the porting process is complete.

Redundancy

In data communications redundancy is the excess of transmitted information over that required to convey the essential information in a noise free circuit. Redundancy is introduced intentionally in some systems, as in the case of error detection or correction codes. Surplus capability is usually provided to improve the reliability and quality of service.

Redundancy check

A check that uses one or more extra bits, digits or characters attached to the data which allows for the detection of errors.

Refarming

A term given to the practice of redistributing licensed spectrum for alternative uses or users.

Reference point

A conceptual point at the conjunction of two non overlapping functional entities or groups.

Reflection

The sudden change in direction of a wave front at an interface between two dissimilar media so that the wave front returns into the medium from which it originated. Depending on the nature of the interface reflection may be mirror like or may diffused.

Refractive index

The Refractive index of a medium is the ratio of the velocity of propagation of an electromagnetic wave in a vacuum to its velocity in the medium.

REG - Resource Element Group

As part of the E-UTRA radio frame structure a REG (Resource Element Group) consists of 4 RE (Resource Elements). The system then groups 9 REGs to form a CCE (Control Channel Element), which in turn is used to define the PDCCH.

Regeneration

Term usually applied to digital or fibre optical repeaters whereby digital signals are amplified, reshaped, retimed, and retransmitted.

Registration

A procedure by which the MS (Mobile Station) identifies its location and sends parameters to the network.

Registration Area

A Registration Area is an area in which the mobile may roam without a need to perform location registration.

Registration Zone

A Registration Zone is a collection of one or more BS (Base Station) which enables the MS (Mobile Station) to decide whether it should perform a zone based registration.

Relay

A device capable of relaying communications.

Release

A process used to identify the release of a channel or call.

Releases - Releases (GSM)

A particular version of the standards documents produced by the 3GPP (Third Generation Partnership Project).

Reliability

The reliability parameter indicates the transmission characteristics that are required by an application. The reliability class defines the probability of loss, duplication, mis sequencing or corruption of SDU (Service Data Unit).

Remaining Set

This term identifies the set of all allowable pilot offsets. This excludes the pilot offsets in the Active Set , Candidate Set , and Neighbor Set pilots.

Remote access

In essence it refers to workers being able to access their organization’s network, from any or from a designated location. A dial up connection through desktop, notebook, or handheld computer over regular telephone lines or ISDN (Integrated Services Digital Network) is a common method of remote access. The latest technologies use wireless, cable modem, and DSL (Digital Subscriber Line) for remote access.

Repeater

A repeater is a radio transceiver used to extend the transmission of a radio signal beyond its normal range. Repeaters typically are used for buildings, tunnels or difficult terrain.

Replay Attack

Indicates an attempt by a unauthorized third party to record an over the air message; this may be used later in a process to fool the receiver.

Requested QoS

GPRS QoS (Quality of Service) profile that is requested at the beginning of a GPRS QoS session. QoS modification requests are also possible during the lifetime of a QoS session.

Required Eb/No+Io - Required Eb/(No+Io) (dB)

The ratio between the received energy per information bit to the total effective noise and interference power density needed to satisfy the quality objectives.

Reseller

An independent company that buys airtime in bulk at wholesale rates from carriers. This airtime is then resold to individuals or companies. The difference between the wholesale and retail rate is their margin allowing for operating expenses, such as billing, customer service, etc.

Reservation Access Mode

A mode used on the Enhanced Access Channel and Reverse Common Control Channel where a MS (Mobile Station) transmits a preamble and a header on the Enhanced Access Channel before moving to the Reverse Common Control Channel.

Residual error rate

Residual error rate describes the service accuracy. The frequency of lost, corrupted or duplicated SDU (Service Data Unit).

REST - REpresentational State Transfer

The REST architectural style is essentially a set of common principles against which APIs (Application Programming Interfaces) can be developed for a variety of different scenarios, including the 5G Core.

Reverse CDMA Channel

Identifies the CDMA (Code Division Multiple Access) channel sent from the MS (Mobile Station) to the BS (Base Station). The BS (Base Station) will receive a combination of multiple reverse CDMA channels from different mobiles.

Reverse Common Control Channel

A logical channel that carries higher layer traffic from multiple users to the BS (Base Station). This channel can operate in a Reservation Access Mode or Designated Access Mode.

Reverse Dedicated Control Channel

A logical channel that carries higher layer information from the user to the BS (Base Station) on the reverse CDMA channel.

Reverse Fundamental Channel

Identifies a portion of a Traffic Channel which is able to carry a combination of primary and secondary data, signalling, and power control information. The Reverse Fundamental Channel is transmitted on the Reverse CDMA Channel.

Reverse Pilot Channel

The Reverse Pilot Channel is transmitted either continuously or in gated mode; this enables a BS (Base Station) to acquire the necessary timing of the Reverse CDMA Channel and also provides a phase reference for the demodulation process. The Reverse Pilot Channel is utilized when the Reverse Common Control Channel, Enhanced Access Channel, or Reverse Traffic Channel is enabled.

Reverse Power Control Subchannel

This is a subchannel on the Reverse Pilot Channel which is used by the MS (Mobile Station) to control the forward power when operating on the Forward Traffic Channel with RC (Radio Configuration) 3 to 9.

Reverse Supplemental Channel

An optional portion of a Reverse Traffic Channel which operates with the Fundamental Channel to provide higher data rate services. This channel is transmitted on the Reverse CDMA Channel.

Reverse Supplemental Code Channel

An optional portion of a Reverse Traffic Channel which operates with the Fundamental Channel to provide higher data rate services. The Supplemental Channel that is transmitted on the Reverse CDMA Channel. This channel allows a combination of primary data, secondary data, or both to be transmitted. It does not however support signalling.

Reverse Traffic Channel

The Traffic Channel on which data and signalling are transmitted from the MS (Mobile Station) to the BS (Base Station). The Reverse Traffic Channel consists of: 0 or 1 Reverse Fundamental Channel, 0 to 7 Reverse Supplemental Code Channels, 0 to 2 Reverse Supplemental Channels, 0 or 1 Reverse Dedicated Control Channel.

RF - Radio Frequency

Any frequency within the electromagnetic spectrum normally associated with radio wave propagation.

RF - Rating Function

A logical element of the 3GPP online billing system, responsible for determining the rate at which credit should be decremented.

RFA - Radio Fixed Access

Technology that enables operators to provide customers with direct connection to the public telecommunications network via a fixed radio link from the home or premises to the local exchange, instead of providing a ‘wired’ connection using copper cables or optical fibre.

RFC - Request For Comments

A Request for Comments is a formal document from the IETF (Internet Engineering Task Force) which provides the standard for a particular protocol or technology. It is the result of committee drafting and subsequent review by interested parties. RFC may be informational in nature. Some RFC may be intended to become Internet standards, then the final version of the RFC becomes the standard and no further comments are permitted. Changes can still occur through subsequent RFC that supersede or build on all or parts of previous RFC.

RFC 2544

RFC 2544 is a testing methodology widely used to assess the performance of an Ethernet based network. It was designed to evaluate the performance characteristics of network devices primarily in a lab environment and has been widely adapted to provide performance metrics of Ethernet based network services. RFC 2544 defines a number of out of service tests that can used to describe the performance characteristics of a network interconnecting device. In addition, the standard describes the specific formats for reporting the results of the tests. Tests include Burst, Throughput, Latency and Frame Loss.

RFCOMM - Radio Frequency Communications Protocol

The Bluetooth system uses the Radio Frequency Communications Protocol to emulate serial ports over the L2CAP (Logical Link Controller and Adaptation Protocol). The protocol is based on the ETSI standard TS 07.10, however only a subset of this standard is used within Bluetooth. The RFCOMM protocol is capable of supporting up to 60 simultaneous connections between two Bluetooth devices. The number of connections that can be used simultaneously in a Bluetooth device is implementation-specific.

RFCOMM Client

In Bluetooth , the RFCOMM (Radio Frequency Communications Protocol) client is the application requesting a connection to another application, which in turn is called the RFCOMM server.

RFCOMM initiator

In Bluetooth , the RFCOMM (Radio Frequency Communications Protocol) initiator is the device initiating the RFCOMM session.

RFCOMM Server

In Bluetooth , an RFCOMM (Radio Frequency Communications Protocol) server is the application awaiting a connection from an RFCOMM client.

RFE - Routing Functional Entity

A UMTS functional entity within RRC (Radio Resource Control) that deals with the routing of higher layer messages to different MM (Mobility Management) and CM (Connection Management) entities on the mobile. Within the UTRAN (UMTS Terrestrial Radio Access Network) the RFE deals with routing to different core network domains.

RFID - Radio Frequency Identification

RFID (Radio Frequency Identification) is quickly gaining global popularity in a wide range of different scenarios, from stock tracking to access control. RFID essentially works by implanting a small passive or active RF (Radio Frequency) transponder within a device which is commonly termed an RFID Tag. The tag, if passive, will respond when a RFID scanner is passed over it. Alternatively, an active tag constantly transmits identification information up to a distance of several meters.

RFP - Radio Fixed Part

A DECT base station is called a RFP (Radio Fixed Part).

RI - Rank Indication

This is a E-UTRA parameter related to MIMO feedback for some of the E-UTRA transmission modes. It represents the transmission rank, i.e. the number of layers that can be supported under the current channel conditions.

Rijndael

Rijndeal is a symmetric block cipher with a variable block size of 128bit, 192bit, or 256bit and a variable key length of 128bit, 192bit, or 256bit. Rijndael is the algorithm used in AES (Advanced Encryption Standard).

RIM - RAN Information Management

This function is a generic mechanism that allows the request and transfer of information between two RAN nodes via the core network, e.g. SON information.

RIP - Routing Information Protocol

Routing Information Protocol is used to manage router information within a self contained network such as a corporate LAN (Local Area Network) or an interconnected group of such LAN. RIP is classified by the IETF (Internet Engineering Task Force) as one of several internal gateway protocols called IGP (Interior Gateway Protocols).

RIR - Regional Internet Registry

Although ICANN have overall responsibility for the global IPv4 and IPv6 address space, part of that responsibility is handed to each of the five RIR that operate around the globe. In basic terms, the RIRs are given chunks of IP address space which they are expected to manage. Those RIR include RIPE NCC, AFRINIC, APNIC, LACNIC and ARIN, each of which operate within their own region of the world. In turn, these RIR will further disseminate their IP address space allocations to national internet registries and ISPs.

RISC - Reduced Instruction Set Computer

RISC (Reduced Instruction Set Computer) is a microprocessor that is designed to perform a smaller number of computer instructions so that it can operate at a higher speed. Since each instruction type that a computer must perform requires additional transistors and circuitry, a larger set of computer instructions makes the microprocessor more complicated and slower in operation.

RIV - Resource Indication Value

This is a E-UTRA scheduling parameter that typically corresponds to a starting resource block and a length in terms of contiguously allocated resource blocks.

RLL - Radio in Local Loop

The technical approach of providing customer connection to the public network via a fixed radio link from the home or premises to the local exchange. This is implemented instead of providing a wired connection using copper cables or optical fibre.

RLP - Radio Link Protocol

Radio Link Protocol terminates at the MS (Mobile Station) and the IWF (Interworking Function) generally located at the MSC (Mobile Switching Centre). It utilizes the reliability mechanisms of the underlying protocols in order to deliver data.

RLS - Resource List Server

RFC 4622 defines the use of Resource Lists and RLS as a means of reducing the significant signalling overhead associated with providing SIP (Session Initiation Protocol) based Presence services. As such, the RLS acts as a termination point for SUBSCRIBE messages from SIP clients, interacting with resource lists to carry out presence services on behalf of the user in order to reduce traffic.

RNA - RAN Based Notification Area

The 5G RAN includes a sub-state called “RRC Inactive”. In this state, air interface resources are released but the device’s context remains on the last serving gNB. If the last serving gNB receives downlink data from the UPF, or signalling from the AMF, it pages in the cells corresponding to the RNA (RAN Based Notification Area). This can include sending Paging to neighbour gNB(s), which belong to the RNA, across the Xn interface. Whilst in the RRC Inactive state, the device will perform a RNA update procedure if it moves to a cell which is not part of the current RNA assigned.

RNC - Radio Network Controller

The RNC is a functional element of the UMTS RNS (Radio Network System) which controls a number of Node Bs. Responsibilities of the RNC include radio resource management and control, air interface security, mobility procedures and system synchronization. Three types of RNC exist, SRNC (Serving RNC), DRNC (Drift RNC) and CRNC (Controlling RNC).

RNS - Radio Network Subsystem

The UTRAN (UMTS Terrestrial Radio Access Network) consists of one or more RNS (Radio Network Subsystem). Each RNS control the allocation and the release of specific radio resources to establish a connection between a UE (User Equipment) and the UTRAN. A RNS is responsible for the resources and transmission/reception in a group of cells.

RNSAP - Radio Network Subsystem Application Part

RNSAP supports communication over the Iur interface in order to support inter RNC (Radio Network Controller) procedures such as soft handovers. RNSAP utilizes the services of SCCP (Signalling Connection Control Part) and either ATM or IP.

RNTI - Radio Network Temporary Identifier

A Radio Network Temporary Identifier is used to identify a UE when an RRC connection exists. The following types of RNTI are defined: C-RNTI (Cell RNTI), S-RNTI (Serving RNC RNTI) and U-RNTI (UTRAN RNTI).

RNTP - Relative Narrowband Tx Power

This E-UTRA parameter provides an indication on downlink power restriction per PRB in a cell and other information needed by a neighbour eNB for interference aware scheduling.

ROADS - Running Out of ADdressSpace

Term used to describe the situation being faced by the Internet community due to the exhaustion of IPv4 Addresses. As a result, the IETF (Internet Engineering Task Force) introduced a technique known as Classless Addressing or CIDR (Classless Inter-Domain Routing) which enabled IP addresses to be used more efficiently. The longer term solution to the problem is IPv6.

Roamer

A MS (Mobile Station) receiving services in a network other than the one from which the MS has subscribed.

Roaming

The ability for a user to function when the serving network is different from their home network.

ROHC - Robust Header Compression

A mechanism which reduces the number of bits which are required to be sent across the air interface. The compression technique takes into account header fields that don’t change on a packet by packet basis, or change in a highly predictable manner. Each of these attributes can be exploited as part of the compression process to significantly reduce header field transmission overheads.

ROI - Return On Investment

ROI is a figure which indicates the ratio of money which is gained or lost relative to the amount of money initially invested. ROI is not a telecommunications centric term and can be applied to a range of scenarios.

ROM - Read Only Memory

Read Only Memory is built in computer memory containing data that normally can only be read but not written to. ROM contains the programming that allows the computer to be booted up. ROM is not lost when the computer power is turned off. The ROM is sustained by a small long-life battery in the computer.

ROSE - Remote Operation Service Element

A protocol that provides remote operation capabilities that enables an application to invoke an operation to be performed by a remote peer application and to receive a report of the results. The ROSE protocol itself is only a vehicle for conveying the arguments and results of the operation as defined by the application.

Router

A router is a device that determines the next network point to which a packet should be forwarded towards its destination. The router is connected to at least two networks and decides which way to send each information packet based on its current understanding of the state of the networks it is connected to.

RP - Relay Protocol

A protocol used in the relaying of SMS messages between the mobile and the Short Message Service Centre.

RPE-LTP - Regular Pulse Excited Long Term Prediction

The Regular Pulse Excited Long Term Prediction is used by GSM for full rate speech coding.

RQI - Reflective QoS Indicator

In 5G, the RQI is contained within the encapsulation header of the downlink user plane in order to notify the device that Reflective QoS is required for that specific SDF (Service Data Flow).

RR - Radio Resource

RR is the protocol used for radio resource management across the Um interface for circuit switched and GPRS services. RR supports procedures associated with processes such as SI (System Information) broadcasting, radio connection establishment, radio channel management and measurement reporting.

RRBP - Relative Reserved Block Period

In GPRS the Relative Reserved Block Period value specifies a single uplink block in which the mobile station shall transmit either a Packet Control Acknowledgement message or a PACCH (Packet Associated Control Channel) block to the network.

RRC - Radio Resource Control

A sublayer of Layer 3 on the UMTS radio interface; it exists in the control plane only and provides information transfer service to the NAS (Non Access Stratum). RRC is responsible for controlling the configuration of UMTS radio interface Layers 1 and 2.

RRC - Radio Resource Control (UMTS)

RRC is a sublayer of Layer 3 on the UMTS radio interface; it exists in the control plane only and provides an information transfer service to NAS (Non Access Stratum) signalling. RRC is also responsible for controlling the configuration of the UMTS radio interface, facilitating the establishment and management of radio bearers, mobility management and security.

RRC Connection

A point to point bi directional connection between the RRC (Radio Resource Control) entities on the UE (User Equipment) and UTRAN (UMTS Terrestrial Radio Access Network). The UE requires an RRC connection to access the services of the UMTS network.

RS - Reference Signals

In the LTE E-UTRA there are various types of reference signals used in the uplink and downlink directions. In the uplink there are two types namely the Demodulation reference signal and the Sounding reference signal. In the downlink, there are three main types: Cell Specific (non-MBSFN), MBFSN (Multimedia Broadcast Multicast Service Single Frequency Network) and UE Specific.

RSA - Rivest, Shamir, Adleman

RSA describes a public key encryption algorithm and certification process to protect user data over networks. The system was designed by Ron Rivest, Adi Shamir, and Leonard Adleman who formed RSA Security Inc. The patent for the RSA process expired in September 2000 and now is available for general use.

RSA - Rural Service Area

Designation of a non metropolitan area covered by a cellular licensee.

RSeq - Response Sequence

RSeq is a SIP (Session Initiation Protocol) header field which is used in support of the PRACK method.

RSL - Radio Signalling Link

RSL is used for supporting traffic management procedures, as well as communication between the mobile and the network. There is one RSL per TRX (Transceiver).

RSL - Received Signal Level

The signal level at a receiver input. The RSL is usually expressed in dB (Decibel) with respect to 1 mW, i.e., 0 dBm.

RSN - Robust Security Network

The term Robust Security Network is used in WiFi networks to describe the security enhancements encompassed in the IEEE 802.11i and WPA (WiFi Protected Access) 1 and 2 variants. The suite of protocols endeavours to compensate for the weaknesses associated with WEP(Wired Equivalent Privacy).

RSQI - Received Signal Quality Indicator

This is a Traffic Channel measurement of signal quality.

RSRP - Reference Signal Received Power

The LTE E-UTRA requires various measurements to be made. The RSRQ (Reference Signal Received Quality) and is defined as NxRSCP / (E-UTRA carrier RSSI ), where N is the number of RB s defined by the E-UTRA carrier RSSI measurement bandwidth.

RSRQ - Reference Signal Received Quality

This is a E-UTRA UE measurement defined as the ratio SRP / (E-UTRA carrier RSSI), where N is the number of RBs of the E-UTRA carrier RSSI measurement bandwidth. It is used as part of the RRC measurement process when evaluating cells.

RSSI - Received Signal Strength Indication

The measured power of a received signal.

RSU - Road Side Unit

In relation to V2X, an RSU is a stationary infrastructure entity that supports V2X applications that can exchange messages with other entities supporting V2X applications.

RSVP - Resource Reservation Protocol

Resource Reservation Protocol is a set of communication rules that allows connections or resources on the Internet to be reserved. RSVP is part of the Internet IntServ (Integrated Service) model, which ensures best effort service, real time service, and controlled link sharing. Although Intserv has not seen widespread use, an extension to RSVP which supports Traffic Engineering, termed RSVP-TE, is used widely in MPLS networks.

RTCP - RTP Control Protocol

RTCP is a protocol designed to provide feedback on the quality of data distribution during RTP payload transfer activity. It is an integral part of RTP’s role by transferring statistics and information on packet counts, jitter and round trip times.

RTD - Real Time Difference

This means the relative synchronization difference in the network between two base stations.

RTI R - audio Transaction Identifier

In GPRS the Radio Transaction Identifier is used to group the downlink RLC / MAC (Radio Link Control / Medium Access Control) control blocks that make up an RLC/MAC control message and identifies the segmented control message sequence with which the downlink RLC/MAC control block is associated. The RTI field is five bits in length with range 0 to 31.

RTP - Real time Transport Protocol

RTP is a protocol designed to transfer real time media payloads, including voice and video. The protocol is used extensively in both 3GPP and non-3GPP networks, with a prime example being the transport of voice packets between MGWs (Media Gateways). RTP is also used to support end to end voice transfer in the VoLTE (Voice over LTE) architecture. The protocol itself provides services such as payload identification, sequential delivery and jitter correction via a timestamp. In addition, RTP uses a companion protocol termed RTCP (Real time Transport Control Protocol) in order to provide feedback for ongoing sessions e.g. no. of dropped packets, jitter, etc.

RTS - Request To Send

This is a signalling message transmitted by an IEEE 802.11 Station in order to indicate that it has data to transmit and to prevent other wireless Stations seizing the radio link. This message forms part of the 802.11 CSMA/CA (Carrier Sensing Multiple Access / Collision Avoidance) process.

RTSP - Real Time Streaming Protocol

The RTSP (Real Time Streaming Protocol) is a client-server application-level protocol for controlling the delivery of data with real-time properties. It establishes and controls either a single or several time-synchronized streams of continuous media, such as audio and video. It uses transport protocols such as UDP , multicast UDP, TCP , and RTP to deliver the continuous streams. In other words, RTSP acts as a network remote control for multimedia servers. Sources of data can include both live data feeds and stored clips.

RX - Receiver

The terminator of any signal on a transmission medium.

RXQUAL - Received Signal Quality

In a radio system RXQUAL indicates the average signal quality received.

S interface

For basic rate access in an ISDN (Integrated Services Digital Network) environment, a user to network interface reference point that is characterized by a 4 wire, 144Kbps (2B+d) user rate.

S-Band

The frequency spectrum near 2GHz used for land based microwave and some mobile satellite communications.

S-CCPCH - Secondary Common Control Physical Channel

The Secondary Common Control Physical Channel is used to carry the FACH (Forward Access Channel) and PCH (Paging Channel) in the UMTS system.

S-CSCF - Serving – Call Session Control Function

The S-CSCF is the primary node in the IMS responsible for session control. Subscribers will be allocated a S-CSCF for the duration of their IMS registration in order to facilitate routing of SIP messages as part of service establishment procedures. Consequently, the S-CSCF will download a subscriber profile from the HSS (Home Subscriber Server) at the time of registration, which allows the S-CSCF to ascertain which Application Server any service requests should be sent to. The S-CSCF will also be involved in breakout to the PSTN, if this is supported.

S-GW - Serving Gateway

The S-GW is the user data plane ingress and egress point of the E-UTRAN side of the EPC. As such, when the subscriber moves around the E-UTRAN, their point of attachment to the EPC remains fixed at the S-GW (unless the network decides that a S-GW relocation is required). Additional responsibilities include lawful interception of subscriber traffic, as well as downlink data buffering whilst the subscriber is paged.

S-NSSAI - Single – Network Slice Selection Assistance Information

Used in support of Network Slicing, the S-NSSAI is used to uniquely identify a Network Slice. The S-NSSAI contains two components: the SST (Slice/Service Type) and an optional SD (Slice Differentiator).

S-RNTI - Serving RNC Radio Network Temporary Identifier

In UMTS the S-RNTI is the UE (User Equipment) identifier which is allocated by the Serving RNC (Radio Network Controller) and is unique within that SRNC. It is allocated to all UE having a RRC (Radio Resource Control) connection. S-RNTI is reallocated when the Serving RNC for the RRC connection is changed and de-allocated when the RRC connection is released.

S-SCH - Secondary Synchronised Channel

UMTS uses the P-SCH (Primary Synchronization Channel) and S-SCH (Secondary Synchronization Channel) to inform the mobiles of the current cells timing and scrambling code.

S-TMSI - Serving Temporary Mobile Subscriber Identity

The S-TMSI is similar in format to the P-TMSI. It is used to protect the subscribers IMSI during NAS interaction as well as identifying the MME (Mobility Management Entity) or MME pool that is responsible for the UE. The S-TMSI is constructed from the MMEC (MME Code) and the M-TMSI.

S/MIME - Secure Multipurpose Internet Mail Extensions

S/MIME (Secure / Multipurpose Internet Mail Extensions) is a standard specification for secure e-mail within a PKI (Public Key Infrastructure), helping to enable secure communication between two or more parties.

S/P - Supplementary/Polling

Used in some Layer 2 protocols to indicated when a response is required.

S1AP - S1 Application Protocol

S1AP is used between the eNB and the MME in order to support operations such as E-RAB (E-UTRAN Radio Access Bearer) Management, transfer of UE Context information, NAS Signalling transport, Paging and EPC based mobility.

SA - Security Association

A SA (Security Association) is the title given to the secure relationship between two network entities, often as part of the IPSec security architecture. Data passing over the SA can be protected with respect to authentication, integrity and confidentiality.

SA - Service Area

A Service Area consists of one or more cells within a given LA (Location Area) and may be used to assist in the delivery of location based services.

SA NR - Standalone New Radio

A 3GPP 5G deployment configuration where the 5G gNB (Next Generation Node B) connects to the NGC (Next Generation Core).

SAAL - ATM Adaptation Layer for Signalling

In ATM (Asynchronous Transfer Mode), the SAAL (ATM Adaptation Layer for Signalling) provides reliable transport of signalling messages between peer entities. These signalling messages are carried over a PVC (Permanent Virtual Circuit).

SABM - Set Asynchronous Balanced Mode

For systems that work in the ABM (Asynchronous Balanced Mode). This mode is totally balanced, meaning there is no master/slave relationship. Each station may initialize, supervise, recover from errors, and send frames at any time. The DTE (Data Terminal Equipment) and DCE (Data Circuit Terminating Equipment) are treated as equals. The initiator for Asynchronous Balanced Mode sends a SABM.

SAC - Service Area Code

The Service Area Code is a fixed length code of 2 octets used to identify a SA (Service Area) within a LA (Location Area).

SACCH - Slow Associated Control Channel

A GSM signalling channel that provides a relatively slow signalling connection. The SACCH is associated with either a traffic or dedicated channel. The SACCH can also be used to transfer SMS (Short Message Service) messages if associated with a traffic channel.

SACK - Selective Acknowledgement

It is an extension to a protocol which allows the acknowledge reception of specific packets or messages.

SAE - System Architecture Evolution

SAE is a study group whose objective was to develop a framework for an evolution or migration of the 3GPP system to a higher-data-rate, lower-latency, packet-optimized system that supports multiple RATs. It should be noted that this study is also termed EPS (Evolved Packet System) and the terms are inter-changeable.

SAI - Service Area Identifier

The Service Area Identifier is used to identify an area consisting of one or more cells belonging to the same LA (Location Area). Such an area is called a Service Area and can be used for indicating the location of a UE (User Equipment) to the CN (Core Network). The SAC (Service Area Code) together with the PLMN -Id (Public Land Mobile Network Identifier) and the LAC (Location Area Code) will constitute the Service Area Identifier. SAI = PLMN-Id + LAC + SAC.

SAM - ubsequent Address Message

A SS7 (Signalling System No.7) signalling message which carries further dial numbers after the initial address message has been sent.

Sampling rate

The sampling rate indicates the number of samples taken per given unit of time. It identifies the rate at which signals are sampled for subsequent modulation, coding, or quantization.

SAP - Service Access Point

A conceptual point where a protocol layer offers access to its services to the layer above or below.

SAP - Session Announcement Protocol

SAP is a protocol used for broadcasting multicast session information. It is standardized by the IETF (Internet Engineering Task Force) in RFC 2974.

SAPI - Service Access Point Identifier

An identifier given to a SAP (Service Access Point). The SAPI may identify the type of service, signalling, Data transfer, Management etc. required by the higher layer.

SAPSD - Scheduled Automatic Power Save Delivery

The term S-APSD is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancement. It was introduced in order to support power management in QBSS. In essence, it involves a QAP delivering downlink frames which belong to a specified access class to power saving Stations automatically. The Scheduled variant defines fixed intervals of time specified to the Station within a TSPEC.

SAR - Segmentation And Reassembly

A process by which a PDU (Protocol Data Unit) is split or segmented in order for it to be transported over a given medium. The segments will then be reassembled to form the original PDU.

SAT - SIM Application Toolkit

The SIM (Subscriber Identity Module) Application Toolkit function resides on GSM. It essentially enables the SIM card to drive the GSM handset, allowing an interactive exchange between a network application and the end user.

Satellite

A communication device designed to orbit about the earth and relay information to ground stations or mobiles.

Satellite communications

A telecommunications service provided via one or more satellites.

Satellite phone

A wireless phone that utilizes satellites to relay the voice and data signals.

SB - Synchronisation Burst

Information used by the receiver to get synchronized to an incoming signal.

SBA - Service Based Architecture

SBA is the name given to the 5G Core network, in which the control plane elements operate as VNFs (Virtualized Network Functions). Communication between VNFs is based on RESTful based API exchange, allowing a given VNF to offer “services” to other VNFs.

SBC - Session Border Controller

A SBC is a SIP based Application Level Gateway, deployed in next generation networks to provide services and features such as NAT Traversal, Security, Lawful Intercept, QoS Enforcement, Encryption and Interoperability.

SBCF - Session Based Charging Function

In the 3GPP specifications, the SBCF is a key function of the OCF (Online Charging Function). As such, its role is to carry out session based charging and credit control. This role is carried out at the bearer, subsystem and service level, with the SBCF denying a subscriber their request if credit is not available.

SBI - Service Based Interface

SBI is the term given to the API based communication that can take place between two VNFs (Virtualized Network Functions) within the 5G SBA (Service Based Architecture). A given VNF can utilise an API call over the SBI in order to invoke a particular service or service operation.

SBLP - Service Based Local Policy

SBLP is a QoS control mechanism which is typically employed in cellular networks.

SC-FDMA - Single Carrier

LTE uplink requirements differ from downlink requirements in several ways. Not surprisingly, power consumption is a key consideration for UE terminals. The high PAPR and related loss of efficiency associated with OFDM signalling are major concerns. As a result, an alternative to OFDM was sought for use in the LTE uplink. SC-FDMA is well suited to the LTE uplink requirements. The basic transmitter and receiver architecture is very similar (nearly identical) to OFDMA, and it offers the same degree of multipath protection. Importantly, because the underlying waveform is essentially single-carrier, the PAPR is lower.

Scattering

Scattering is where the direction, frequency, or polarization of the wave is changed when the wave encounters discontinuities in the medium, or interacts with the material at the atomic or molecular level.

Scattering loss

The part of the transmission power which is lost that results from scattering within a transmission medium or from roughness of a reflecting surface.

Scatternet

In Bluetooth , a Scatternet is two or more Piconets that are co-located in the same area. A Scatternet can exist with or without inter-piconet communication.

SCC - Service Centralization and Continuity

Service Centralization and Continuity is the term given to the network feature which sees all calls, whether originating/terminating on CS or PS access, to be managed centrally by the IMS. Moreover, the continuity aspect ensures that ongoing sessions such as voice calls can be seamlessly switched between different access technologies as the user moves around.

SCC AS - Service Centralization and Continuity Application Server

The SCC AS acts as a B2BUA within the IMS architecture. It’s role is to facilitate service centralization, as well as coordination of SR-VCC handover procedures.

SCCP - Signalling Connection and Control Part

Although MTP3 (Message Transfer Part 3) provides routing capabilities in the guise of Point Codes, there is an inherent limitation when two SS7 networks need to exchange SS7 messages since point codes can overlap. SCCP overcomes this problem by adding a higher level of addressing in the form of unique Global Titles. Consequently, using SCCP in the protocol stack permits the routing of higher layer SS7 messages on a global basis. In addition, SCCP can operate in a connection orientated or connectionless state, with reliable delivery of messages if required.

SCE - Service Creation Environment

In an IN (Intelligent Network) this is a set of functions to support service creation processing by altering service logic and service data on behalf of the controlling node.

SCEF - Service Capabilities Exposure Function

The SCEF was introduced in Release 13 of the 3GPP specifications and was designed to provide a means to securely expose the services and capabilities provided by the 3GPP network interfaces. This SCEF is specifically deployed in support of IoT, whereby devices can use NIDD (Non IP Data Delivery) in order to exchange data with the MME, which in turn passes that data to the SCEF for onward delivery to IoT application servers.

SCEF - Service Creation Environment Function

In an IN (Intelligent Network) this is a set of functions that support the service creation process the output of which includes both service logic programs and service data.

SCF - Service Control Function

In an IN (Intelligent Network) this is the application of service logic to control functional entities in providing Intelligent Network services.

SCFE - Shared Control Functional Entity

In UMTS the SCFE (Shared Control Function Entity) is located in the CRNC (Controlling Radio Network Controller), which controls the allocation of the PDSCH (Physical Downlink Shared Channel) and PUSCH (Physical Uplink Shared Channel) using lower layer services.

SCG - Secondary Cell Group

With respect to Dual Connectivity, SCG is the term given to the group of serving cells associated with the Secondary RAN node.

SCH Channel SCH - Synchronisation Channel

The Synchronization Channel is a downlink signal channel used for cell search and conveying of synchronization information.

SCID - Source Channel Identifier

In a Bluetooth system, the Source Channel Identifier is used in the L2CAP (Link Controller and Adaptation Protocol) layer and represents a channel endpoint on the device sending the request.

SCIM - Service Capability interaction Manager

In the 3GPP based IMS , a particular service offering may actually be comprised of a number of AS (Application Server) working together. In order to manage which AS should be invoked at the correct time as part of a particular service, a SCIM may be employed. This function will essentially take processing load away from the SCSF (Serving Call Session Control Function).

SCM - Station Class Mark

A parameter that identifies certain characteristics of a MS (Mobile Station). An example being its frequency capabilities.

SCO - Synchronous Connection Oriented link

The Synchronous Connection Oriented link is one of the two possible Bluetooth data link types defined. The SCO link is a symmetric, point-to-point link between the master device and a specific slave device. The SCO link reserves slots between the master and the slave and can therefore be considered to provide a circuit switched connection. The SCO link is usually used to support time critical information, e.g. voice, since time critical SCO packets are never retransmitted. The master device can support up to three SCO links, this might be to the same slave or to different slaves. A slave can support up to a maximum of three SCO links, assuming they are from the same master. If the slave has links from different masters, a maximum of two SCO links are available.

SCP - Service Control Point

A physical entity in the IN (Intelligent Network) that implements a SCF (Service Control Function).

SCS - Service Capability Server

The SCS acts as a gateway between the SIP/Diameter based IMS and OSA (Open Service Access) based application servers. OSA/Parlay is an open API (Application Programming Interface) for application access to telecoms network resources.

SCSI - Small Computer Serial Interface

Small Computer Serial Interface is a standard for computer system communication. Commonly used for storage devices and scanners, SCSI is an ANSI (American National Standards Institute) standard.

SCTP - Stream Control Transmission Protocol

SCTP provides sequential, reliable delivery of higher layer data, using logical streams to separate this functionality and hence avoid head of line blocking. An SCTP connection between two network nodes e.g. eNB (Evolved Node B) to MME (Mobility Management Entity) is termed an SCTP Association, which can feature flow control and multihoming as standard capabilities. SCTP provides much of the same functionality as TCP (Transmission Control Protocol), without the inherent drawbacks that TCP can suffer from.

SD - Slice Differentiator

In Network Slicing, the Slice Differentiator is directly related to the SST (Slice/Service Type) and is used as an additional differentiator if multiple Network Slices carry the same SST value.

SDAP - Service Data Adaptation Protocol

SDAP is responsible for QoS Flow handling across the 5G air interface. In particular, SDAP will map a specific QoS Flow within a PDU Session to a corresponding Data Radio Bearer (which has been established with the appropriate level of QoS). In addition, SDAP will mark the transmitted packets with the correct QFI (QoS Flow ID), ensuring that the packet receives the correct forwarding treatment as it traverses the 5G System. For each PDU Session, a single protocol entity of SDAP will be configured. The exception to this is Dual Connectivity, whereby the Master Cell Group and Secondary Cell Group will each have a separate SDAP configuration on the device.

SDAP - Service Discovery Application Profile

The Service Discovery Application Profile defines the features and procedures for an application in a Bluetooth device to discover services registered in other Bluetooth devices and retrieve any desired available information pertinent to these services.

SDCCH - Standalone Dedicated Control Channel

This channel is used in the GSM system to provide a reliable connection for signalling and SMS (Short Message Service) messages. The SACCH (Slow Associated Control Channel) is used to support this channel.

SDes - Source Description

SDes is an RTCP (RTP Control Protocol) variable that provides a description of the participants within a session. This report is present in all compound messages and includes a header and a number of information chunks providing information such as the name of the participant, email address and optionally other contact information.

SDF - Service Data Flow

Describes a flow of packets which represent a service being delivered to a subscriber, such as a flow of voice packets associated with a call or streaming data from a website.

SDF - Service Data Function

The set of functions in a IN (Intelligent Network) that provides for the management of service data in accordance with a service data template.

SDH - Synchronous Digital Hierarchy

A method of transmitting digital information where the data is packed in containers which are synchronized in time enabling relatively simple multiplexing and demultiplexing at the transmitting and receiving ends. The technique is used to carry high capacity information over long distances up to speeds of 10Gbps.

SDL - Specification and Description Language

Specification and Description Language is an object-oriented, formal language defined by the ITU-T (International Telecommunications Union-Telecommunications Standardization Sector).The language is intended for the specification of complex, event driven, real time, and interactive applications involving many concurrent activities that communicate using discrete signals.

SDN - Software Defined Networking

SDN describes the process of abstracting and centralizing much of the control activity related to packet forwarding and handling processes which would typically take place within an individual network router or switch. Therefore, the network router/switch would only be forwarding user plane traffic, whilst receiving control information on forwarding decisions from a centralized SDN Controller. In turn, the SDN Controller can provide an abstracted, end to end view of the network to SDN Applications. These SDN Applications can then request and reserve network resources which are appropriate to that application, ensuring that overall, the packet transport network is much more service and application aware.

SDP - Service Data Point

A physical entity in an IN (Intelligent Network) that implements a SDF (Service Data Function).

SDP - Service Discovery Protocol

The Bluetooth defined Service Discovery Protocol enables applications to discover which services and service characteristics are available on other Bluetooth devices.

SDP - Session Description Protocol

Used predominantly in mobile networks to describe the parameters associated with a media stream, such as IP connection address, ports, required bandwidth and codec description. Typically encountered as a payload of protocols such as SIP, BICC and H.248 GCP.

SDS - Short Data Service

SDS is a MCData service capability that assists with carrying a limited size, but variable payload. This could be a text or an extended message, a hyperlink providing users access to linked and accessible content; such as a large file, situational awareness data, location information or command instructions.

SDSL - Symmetric Digital Subscriber Line

One of the family of DSL (Digital Subscriber Line) services. Unlike ADSL (Asymmetric Digital Subscriber Line), it offers the same data rate speeds of 2Mbps both upstream and downstream.

SDU - Service Data Unit

The Service Data Unit identifies the information transferred between peer layer entities which is not interpreted by the supporting lower layer entities.

Seamless handover

Seamless handover is when a handover from one cell to another takes place without a perceivable interruption of the radio connection.

Search Engine

Search engines are huge databases of web page files that have been assembled automatically by machine. There are two types of search engines – individual and meta searchers. Individual search engines compile their own searchable databases on the web whereas metasearchers do not compile databases. Instead, they search the databases of multiple sets of individual engines simultaneously.

Search Window

Search Window Specifies the range of PN (Pseudorandom Noise) sequence offsets which a MS (Mobile Station) searches for a pilot.

Search Window Offset

Search Window Offset Identifies the PN (Pseudorandom Noise) sequence offset employed by the MS (Mobile Station) when positioning the search window.

Secondary CDMA Channel

Secondary CDMA Channel Identifies a preassigned channel used by the MS (Mobile Station) for initial acquisition.

Secondary Traffic

Secondary Traffic Identifies an additional traffic stream between the MS (Mobile Station) and the BS (Base Station).

Sector

Base Stations are often sectorized to improve efficiency. It should be noted that sectors are cells in their own right.

Security

The ability to prevent fraud and the protection of information availability, integrity and confidentiality.

Security Code

A number used to prevent unauthorized alteration of data programmed into the phone.

Security Mode

Bluetooth has three defined security modes, these are: Security Mode 1 – this is a non-secure mode, since the device will not initiate any security; Security Mode 2 – this provides a service level enforced security mode, providing a flexible access security method by allowing multiple applications to use different security requirements in parallel; Security Mode 3 – this is a link level enforced security mode. The Bluetooth device will initiate security procedures before the link is set-up.

Security Token

This is a credit card size or key-fob sized authentication device that a user carries which usually displays numbers that change over time and synchronizes with an authentication server on the network. May also be encountered as a smartphone app.

SEGW - Security Gateway

The SEGW or Security Gateway forms part of the GANC within a 3GPP Release 6 GAN. It provides the security functionality and in so doing, terminates the IPSec tunnel at the GANC.

Selective Call Barring

The ability to programme a public switched network access line, so that outgoing calls to certain related groups of numbers such as special charge rate, international or mobile services cannot be made.

Semiduplex operation

A method in which simplex operation is used but with two frequencies.

SEPP - Security Edge Protection Proxy

The SEPP is used to protect control plane traffic that is exchanged between different 5G PLMNs (Public Land Mobile Networks). As such, the SEPP performs message filtering, policing and topology hiding for all API messages.

Serial Port

A port through which data is passed serially, i.e., one bit at a time, and that requires only one input channel to handle a set of bits, e.g., all the bits of a byte.

Server

A server is a function on the network which holds information or applications to be accessed by users of the network.

Service Agreement

The contract or agreement a user enters into with the operator. Service agreements usually include a monthly fee.

Service Configuration

The Service Configuration identifies attributes used by the MS (Mobile Station) and the BS (Base Station) which enable them to interpret the traffic channel frames.

Service Discovery

In Bluetooth , Service Discovery describes the ability to discover the capability of connecting devices or hosts.

Service Instance

The term Service Instance identifies a higher layer interaction between the mobile and another endpoint.

Service Negotiation

The MS (Mobile Station) and BS (Base Station) use the Service Negotiation to establish a Service Configuration.

Service Option Connection

This identifies the use of a particular Service Option.

Service Option Connection Reference

A common reference used by the BS (Base Station) and MS (Mobile Station) to uniquely identify a particular Service Option Connection.

Service Option Negotiation

Provides a flexible method allowing the MS (Mobile Station) and BS (Base Station) to establish a Service Configuration.

Service Provider

Service Provider is the generic title given to an organization which provides services to subscribers. Traditionally these services have been telecommunications based however, modern day service providers are diverse organizations which can provide services other than voice and broadband.

Service Provider Network

Identifies a network through which the user is provided services. This may be either the home or visited service provider.

 Service Redirection

Service Redirection Enables the BS (Base Station) to alter the system selection made by a MS (Mobile Station). If testing is required, this enables a temporary divert to an alternate system.

Services

The set of functions that the telecommunication system may make available to the user.

Serving Frequency

Serving Frequency The frequency on which a MS (Mobile Station) is currently communicating with one or more BS (Base Station).

Serving Network

The serving network provides the user with access to the services of their home environment. When roaming, the serving network is referred to as the visited network.

SF - Spreading Factor

In a CDMA (Code Division Multiple Access) system, the number of chips per data symbol is called the SF (Spreading Factor). The lower the spreading factor the higher the data rate.

SFH - Slow Frequency Hopping

Slow Frequency Hopping is a technique in which the carrier frequency changes using a predetermined hopping pattern. The hopping rate is slower than the bit rate.

SFN - Cell System Frame Number

This is used in the UMTS system to identify the framing and timing of a cell on a Node B.

SFN - System Frame Number

This is used in the UMTS system to identify the framing and timing of a cell on a Node B.

SFP - Small-form Factor Pluggable

An SFP is a small hot pluggable transceiver used in data communication and telecommunications networks. SFPs interface between communication devices such as switches, routers and fibre optic cables. They are available in a wide range of interface types to both single mode and multi-mode fibre optics as well as copper cable. Modern SFPs support service assurance and performance monitoring activities.

SgNB - Secondary gNB

A device operating in 5G DC (Dual Connectivity), NGEN-DC (NG-RAN – E-UTRA NR Dual Connectivity) or EN-DC (E-UTRA – NR Dual Connectivity), identifies the Secondary RAN node as the “Secondary gNB”. In the case of EN-DC, it is also identified as the “en-gNB”.

SGsAP - SGs Application Protocol

SGsAP is designed to facilitate mobility management and paging procedures on the SGs interface, as part of CSFB (Circuit Switched Fallback) operation. In addition, SGsAP permits the transfer of SMS delivery via the circuit switched core network when IP based messaging services are not available. Key capabilities of SGsAP include: Paging for non-EPS services, Location Updates for non EPS services, alerting procedures, IMSI detach from EPS services, Mobility Management procedures and failure conditions.

SGSN - Serving GPRS Support Node

The SGSN forms part of the PS core network, providing mobility and session management services to subscribers. This requires the SGSN to hold subscriber data associated with user identification and location. The SGSN facilitates connectivity between the UTRAN/GERAN and the GGSN, generating billing information if required.

SGW - Security Gateway

In an LTE deployment, security gateways are used as VPN concentrators, terminating IPSec connections between the eNB at the cell site and the SGW in the EPC. In particular, both the S1-MME and S1-U will be protected using an IPSec tunnel which terminates at the SGW.

SGw - Signalling Gateway

Signalling interworking between SS7 (Signalling System No 7) and IP based networks is achieved by the use of a SGw. These functions strip off the traditional transport protocols such as MTP (Message Transfer Part) employed in circuit switched networks and replace them with a transport mechanism based on IP, termed SIGTRAN.

SGW-C - Serving Gateway Control plane function

The SGW-C controls the functionality performed by the assigned SGW-U when control and user plane separation is in place. A subscriber is served by a single SGW-C, and can have multiple SGW-Us selected for multiple PDN connections. When the subscriber moves around the E-UTRAN, under control of a SGW-C their point of attachment to the EPC remains fixed at the SGW-U (unless the network decides that a SGW-U relocation is required). Additional responsibilities include lawful interception of subscriber traffic, as well as triggering downlink data buffering whilst the subscriber is paged and PGW pause of charging management based on implemented policies (failed paging, abnormal radio link release and dropped packets/bytes at SGW-U).

SGW-U - Serving Gateway User plane function

The SGW-U is the user data plane ingress and egress point of the E-UTRAN side of the EPC when control and user plane separation is in place. As such, when the subscriber moves around the E-UTRAN, their point of attachment to the EPC remains fixed at the SGW-U (unless the network decides that a SGW-U relocation is required). A single subscriber may be supported by multiple SGW-U if connectivity to multiple PDNs are in place. Additional responsibilities include lawful interception of subscriber traffic, inter-operator accounting, as well as downlink data buffering whilst the subscriber is paged.

SHA1 - Secure Hashing Algorithm 1

SHA1 is one of several cryptographic hashing functions developed by the NSA (National Security Agency). Hashing functions compute a fixed-length digital representation (known as a message digest) of an input data sequence (the message) of any length. They are termed secure when it is computationally infeasible to find a message that corresponds to a given message digest or find two different messages that produce the same message digest. Also, any change to a message should, with a very high probability, result in a different message digest. It should be noted that SHA-1 is considered to be insecure by some industry experts, although SHA-2 and SHA-3 are still potential options.

Shannon’s law

Shannon’s law defines the theoretical maximum rate at which error free digits can be transmitted over a bandwidth limited channel in the presence of noise. It is usually expressed in the form C = W log2(1 + S/N ), where C is the channel capacity in bits per second, W is the bandwidth in Hertz, and S/N is the SNR (Signal to Noise Ratio).

Shared Secret

Shared Secrets are pre-shared keys that have been allocated to the communicating parties prior to the communication process starting. Shared Secrets may be used in PKI (Public Key Infrastructure), however due to the requirement to pre share the keys, it has very poor scaling characteristics.

Shareware

Software which can be trialled for free, then paid for later.

SHCCH - Shared Channel Control Channel

Bidirectional channel that transmits control information for uplink and downlink shared channels between the network and UE (User Equipment). This channel is for TDD (Time Division Duplex) only.

SHF - Super High Frequency

Identified as the frequency band from 3GHz to 30GHz.

SI - Stall Indicator

The Stall indicator bit indicates whether the mobile’s RLC (Radio Link Control) transmit window can advance (i.e., is not stalled) or can not advance (i.e., is stalled). The MS (Mobile Station) shall set the SI bit in all uplink RLC data blocks.

SI-RNTI - System Information

When the E-UTRA eNB sends broadcast messages on the BCCH it uses a SI-RNTI (System Information – Radio Network Temporary Identifier), which is set to 0xFFFF. This is used to CRC encode the broadcast messages, enabling all UEs to correctly decode/identify.

SIB - Service Independent Building Block

A reusable set of FEA (Functional Entity Action) and information flows used to support a service feature or a part of a service feature in an IN (Intelligent Network).

SIB - System Information Block

The system information elements are broadcast in system information blocks. A system information block groups together system information elements of the same nature. Different system information blocks may have different characteristics, e.g. regarding their repetition rate and the requirements of UE (User Equipment) to read the System Information.

SIB1-BR - SIB1 Bandwidth Reduced

As part of LTE-M, SIB1-BR is the new LTE SIB (System Information Block) that has been optimized to facilitate transmission in LTE-M NB (Narrowband).

SID - Silence Descriptor

A frame that conveys information on the acoustic background noise in order to generate comfort noise during periods of silence suppression within a call.

SIDF - Subscriber Identity De-concealing Function

The SIDF is a functional element of the UDM (Unified Data Management), responsible for decrypting a SUCI (Subscription Concealed Identifier) to reveal the subscriber’s SUPI (Subscription Permanent Identifier).

SIF - Service Information Field

A Service Information Field is the payload of an MTP Level 2 (Message Transfer Part Level 2) MSU (Message Signalling Unit).

SIFS - Short Interframe Space

SIFS are found in IEEE 802.11 networks. They are used for the highest priority transmissions enabling Stations with this type of information to access the radio link first. Examples of information which will be transmitted after the SIFS has expired include RTS (Request To Send) and CTS (Clear To Send) messages in addition to positive acknowledgements.

SIG - Special Interest Group

The Bluetooth Special Interest Group mission statement is: develop, publish and promote the preferred short-range wireless specification for connecting mobile products, and to administer a qualification program that fosters interoperability for a positive user experience.

SIG - SS7 to IP Gateway

Signalling interworking between SS7 (Signalling System No 7) and IP based networks is achieved by the use of a SIG. These functions strip off the traditional transport protocols such as MTP (Message Transfer Part) employed in circuit switched networks and replace them with a transport mechanism based on IP, termed SIGTRAN.

SigComp - Signalling Compression

RFC 3320 specifies a protocol on the IETF (Internet Engineering Task Force) standards track that may be used to compress application layer protocols such as SIP (Session Initiation Protocol). In turn SigComp may interface with the three principle transport layer protocols; namely TCP (Transport Control Protocol), UDP (User Datagram Protocol) and SCTP (Stream Control Transmission Protocol). The main driver for the development of SigComp is the planned usage of protocols like SIP which are text based in wireless handsets as part of 2.5G, 3G and 4G cellular networks. Consequently the large message size coupled with relatively low data rates across the radio interface will result in significant transmission delays. SigComp provides a means to eliminate this problem by offering robust, lossless compression of application messages. In SIP SigComp is invoked and negotiated between the client and server. The client initiates the compression mechanism by advertising its ability to employ SigComp through the inclusion of the extension header comp=sigcomp in the request message.

Sigfox

Sigfox is a LPWA (Low Power Wide Area) network technology used within the IoT (Internet of Things) to support communication between devices / sensors and their base stations spanning a region or country where wide area coverage is required.

Signal processing gain

The ratio of the SNR (Signal to Noise Ratio) of a processed signal to the Signal to Noise Ratio of the unprocessed signal. Signal processing gain is usually expressed in dB (decibel).

Signaling Connection

The connection used to carry signaling traffic.

Signaling Traffic

Signaling Traffic Identifies the control messages sent between the MS (Mobile Station) and the BS (Base Station) on the traffic channel.

Signalling

The exchange of information specifically concerned with the establishment/control of connections and management in a telecommunications network.

Sigtran - Signalling Transport

Sigtran is a technique used in service provider IP transport networks in order to carry SS7 (Signalling System number 7) messages between network nodes. This is largely due to the fact that SS7’s lower layers rely on a TDM (Time Division Multiplexed) bearer, such as an E1 or T1 link. Sigtran uses a User Adaptation layer in order to support the regular SS7 border primitives sent between layers of the SS7 protocol stack. In turn, the User Adaptation layer packets are transported across the IP network using SCTP (Stream Control Transmission Protocol) at the Transport Layer. There are various User Adaptation layers available, the choice of which is determined by how much SS7 functionality (in terms of layers) needs to be retained in the IP transport network. Options include SUA (SCCP User Adaptation), M3UA (MTP3 User Adaptation), M2UA (MTP2 User Adaptation) and M2PA (MTP2 Peer to Peer Adaptation).

Silent Re-origination

Silent Reorigination After a user initiated access attempt failure, an autonomous attempt is made to reoriginate a call.

SIM - Subscriber Identity Module

Usually referred to as a SIM card, the SIM (Subscriber Identity Module) is the user subscription to the mobile network. The SIM contains relevant information that enables access onto the subscribed operator’s network.

SIM lock

Software protection which may prevent the SIM (Subscriber Identity Module) being used in a different handset.

SIMPLE - SIP for Instant Messaging and Presence Leveraging

SIMPLE is an IETF (Internet Engineering Task Force) working group which, as its title suggests, is responsible for the development of SIP (Session Initiation Protocol) based IM (Instant Messaging) and Presence services.

Simplex

Simplex communication describes one way communication at any one time.

Simulcast

A signalling technique that broadcasts the same signal over each site in a network.

SIO - Service Information Octet

The Service Information Octet field in a MSU (Message Signalling Unit) contains the 4bit subservice field followed by the 4-bit service indicator. The subservice field contains the network indicator (e.g. national or international) and the message priority (0 to 3 with 3 being the highest priority). Message priority is considered only under congestion conditions not to control the order in which messages are transmitted. Low priority messages may be discarded during periods of congestion. The service indicator specifies the MTP (Message Transfer Part) user thereby allowing the decoding of the information contained in the payload.

SIP - Session Initiation Protocol

SIP is an IETF protocol which was initially designed to establish, maintain and terminate multimedia sessions. Since its initial standardization, SIP has been adopted as the main signalling protocol in a variety of different network architectures. This includes the 3GPP IMS (IP Multimedia System), where existing SIP features have been utilized, in addition to new enhancements which have been specifically created.

SIP-AS - SIP Application Server

SIP application servers host and execute services, acting as proxy servers, originating user agents, terminating user agents, or back-to-back user agents. They can be located in a home or visited network.

SIP-T - SIP for Telephones

SIP for Telephones provides a framework for the integration of legacy telephony signalling into SIP messages. It provides two key characteristics, namely ‘encapsulation’ and ‘translation’. The SS7 ISUP messages arriving at a SIP-ISUP gateway are ‘encapsulated’ within SIP; this makes sure the information necessary for services is not discarded in the SIP request. However, routing decisions for SIP requests are made at proxy servers which cannot be expected to understand ISUP messages. To overcome this, some of the critical information is translated from an ISUP message into the corresponding SIP headers, allowing the SIP request to be routed.

SIPPING - Session Initiation Protocol Project INvestiGation

The Session Initiation Protocol Project INvestiGation is a working group chartered to document the use of SIP for several applications related to telephony and multimedia, developing requirements for any extensions to SIP needed for those applications.

SIPs - Session Initiation Protocol secure

SIPs employs TLS (Transport Layer Security) in order to secure both the SIP protocol header and whatever payload may be in the SIP message body.

SIPPING - Session Initiation Protocol Project INvestiGation

The Session Initiation Protocol Project INvestiGation is a working group chartered to document the use of SIP for several applications related to telephony and multimedia, developing requirements for any extensions to SIP needed for those applications.

SIPs - Session Initiation Protocol secure

SIPs employs TLS (Transport Layer Security) in order to secure both the SIP protocol header and whatever payload may be in the SIP message body.

SIPTO - Selective IP Traffic Offload

SIPTO is a network optimization technique which involves traffic analysis being undertaken at the eNB (Evolved Node B), with selected traffic being transferred across the most optimal path in the core network or even bypassing the core network completely (hence being sent straight to the Internet for instance).

SIR - Signal to Interference Ratio

A ratio between the wanted signal power in the channel and the interference in the channel.

Sky wave

A radio wave that travels upward from the antenna. Sky waves may be reflected back to Earth by the ionosphere.

SL - Signalling Link

The SS7 signalling channel between two signalling terminals SP (Signalling Point) or STP (Signalling Transfer Point) is identified as a SL (Signalling Link).

Slave Device

Within a Bluetooth piconet there may be many Slave Devices, these are all slaves to the Master Device.

SLC - Signalling Link Code

The Signalling Link Code is the number of the SL (Signalling Link) to which SS7 MTP (Message Transfer Part) management messages are related.

Sleep mode

Designed to conserve battery life, this mode automatically turns off a terminal after it has been unused for a specified period of time. The unit is reactivated periodically and when the keypad is touched.

SLF - Subscription Locator Function

In an IMS network where multiple separate instances of the HSS can exist, an SLF is used by various network nodes in order to ascertain which HSS holds the subscriber profile of a particular IMS subscriber. Interaction with the SLF is based on Diameter.

SLIP - Serial Line Internet Protocol

A data communications standard to connect to the Internet across a Modem-based link. SLIP is being replaced by PPP (Point to Point Protocol). Many Internet companies offer SLIP or PPP connections to the Internet.

Slotted Mode

Slotted Mode Mode in which the MS (Mobile Station) monitors selected slots on the PCH (Paging Channel) or the FCCCH (Forward Common Control Channel) when in the idle state. This increases the MS (Mobile Station) battery life.

SLR - Source Local Reference

Signalling Connection Control Part will allocate a SLR for each connection orientated service between two SCCP nodes.

SLRC - Station Long Retry Counter

The Station Long Retry Counter is used in WiFi during error recovery procedures. The counter is incremented each time a frame over the RTS (Request To Send) threshold is received in error. This in turn increases the contention window maximum value.

SLS - Signalling Link Selection

Usually the user of the MTP (Message Transfer Part) layer in SS7 will allocate a SLS value. Different SLS values may lead to load sharing and will also help to provide sequence integrity.

SM - Session Management

This function exists in the mobile and in the SGSN (Serving GPRS Support Node) and handles PDP (Packet Data Protocol) Context Activation, Modification, Deactivation, and Preservation Functions.

SM-DP - Subscription Manager – Data Preparation

This is a term used within the GSMA’s Remote SIM Provisioning standard to describe the function of preparing both bootstrap and operational profiles which will be securely provisioned on an eUICC.

SM-SR - Subscription Manager – Secure Routing

This is a term used within the GSMA’s Remote SIM Provisioning standard to describe the function of securely transporting both platform and profile management commands in order to load, enable, disable and delete profiles from the eUICC.

Smart antenna

An antenna system whose technology enables it to focus its beam on a desired signal to reduce interference. A wireless network would employ smart antennas at its base stations in an effort to reduce the number of dropped calls, improve call quality and improve channel capacity.

Smart card

A card containing a processor and memory to store important data about a person’s identity to allow access to a network or premises.

SMDS - Switched Multi megabit Data Service

A connectionless, broadband, packet switched data service that provides LAN (Local Area Network) like performance and features.

SME - Short Message Entity

An entity which may send or receive Short Messages. The SME may be located in a fixed network, a mobile, or a SMSC (Short Messages Service Centre).

SMF - Service Management Function

The set of processes in an IN (Intelligent Network) that support the management of user and/or network information including service data and Service Logic programs that are required for the proper operation of a service.

SMG - Special Mobile Group

The ETSI (European Telecommunications Standards Institute) technical committee SMG (Special Mobile Group) has the primary responsibility within ETSI for coordinating some aspects of GSM.

SMH - Signalling Message Handling

A function at level 3 of MTP (Message Transfer Part) that provides message discrimination message routing and message distribution services.

SMLC - Serving Mobile Location Centre

The Serving Mobile Location Centre is found within a PLMN (Public Land Mobile Network) and is used to calculate positional information and coordinate location based services. An SMLC controls a number of LMU (Location Measurement Unit) in order to obtain radio interface measurements required to locate or help to locate a specific subscriber.

SMP - Service Management Point

A physical entity in an IN (Intelligent Network) that implements a service management function.

SMpSDU - Support Mode for predefined SDU size

The UMTS Iu Interface uses the Iu Protocol, which can be operated in either TrM (Transparent Mode) or SMpSDU (Support Mode for predefined SDU size mode). SMpSDU is intended for those RAB (Radio Access Bearer) that require extra functionality from the Iu user part protocol other than transfer of user data.

SMS - Short Message Service (Generic)

The SMS (Short Messaging Service) that allows a SME (Short Message Entity) to send short text messages to other SME.

SMS - Short Message Service (GSM)

The Short Message Service was introduced in the first phase of GSM during 1991 as a simple store and forward text messaging system. Even though nearly all GSM mobile phones were capable of supporting SMS, the take up was very limited as network operators or carriers failed to market the system. However, this has all changed with tens of billions of text messages being sent each month. A significant proportion of this rapid growth can be attributed to the inclusion of SMS into youth culture. In fact it has introduced a new text language to bypass the often awkward text entry or MMI (Man Machine Interface). SMS messages are limited to 160 characters in length although it is possible to concatenate several messages to produce a much greater macro message.

SMSC - Short Message Service Centre

The SMSC is responsible for storing and forwarding SMS messages, which are delivered to the SMSC by MSCs as a payload of MAP (Mobile Application Part) signalling.

SMSF - Short Message Service Function

In 5G networks, the SMSF supports the transfer of SMS over NAS. In this capacity, the SMSF will conduct subscription checking and perform a relay function between the device and the SMSC (Short Message Service Centre), through interaction with the AMF (Core Access and Mobility Management Function).

SMTP - Simple Mail Transfer Protocol

The TCP/IP (Transmission Control Protocol/Internet Protocol) protocol which facilitates the transfer of electronic-mail messages, specifies how two systems are to interact, and the format of messages used to control the transfer of electronic mail.

SN - Service Node

A physical entity in an IN (Intelligent Network) that contains the service control function service data function specialized resource function and service switching/call control functions.

SN - Subscriber Number

The number dialled to reach a customer in a telecoms network.

SNAP - Sub Network Access Protocol

SNAP is used in the IEEE (Institute of Electrical and Electronics Engineers) 802.2 LLC (Logical Link Control) protocol as a mechanism for multiplexing more protocols than can be distinguished by the 8bit 802.2 SAP (Service Access Point) fields. SNAP supports identifying protocols by Ethernet type field values in addition to vendor specific protocol identifiers.

SNDCP - Sub Network Dependent Convergence Protocol

In addition to the protocols used to carry GMM (GPRS Mobility Management) information across the Gb interface; namely LLC (Logical Link Control) and BSSGP (Base Station Subsystem GPRS Protocol), a further protocol exists which is used to transfer data between the mobile and the SGSN as a result of the activation of a PDP Context. Termed SNDCP (Sub Network Dependent Convergence Protocol), the protocol resides on top of LLC and provides compression and segmentation services to the protocols being carried in GPRS – IPv4 and IPv6.

Sniff Mode

Once a Bluetooth device is synchronized to a piconet, it can enter one of three power saving modes. In this mode the activity is lowered, enabling a slave device to listen at a reduced rate to the piconet. The interval or period between sniffs is configurable based on the applications using the device. Sniff mode is the least power efficient of all three power saving modes.

SNM - Signalling Network Management

Level 3 function of MTP (Message Transfer Part) that provides continuous supervision of the signalling network. SNM uses autonomous and manual network control functions to ensure optimal use of available signalling resources.

SNMP - Simple Network Management Protocol

Simple Network Management Protocol is part of the TCP/IP (Transmission Control Protocol/Internet Protocol) suite and is used to control and manage IP gateways and other network functions.

SNPN - Standalone NPN

An SNPN is an example of a Private 5G network which has been deployed separately to the Public 5G network. As such, the Private 5G network is standalone, with no dependencies on the Public 5G network.

SNR - Serial Number

The Serial Number forms part of the IMEI (International Mobile Equipment Identity) and uniquely identifies each ME (Mobile Equipment) with a given TAC (Type Approval Code) and FAC (Final Assembly Code). It is six digits in length.

SO - Service Option

A 3GPP2 term used to identify a specific service. Examples of Service options include, speech utilizing a particular codec, type of traffic e.g. SMS (Short Message Service), or a connection type such as IP (Internet Protocol).

SOAP - Simple Object Access Protocol

SOAP is a messaging protocol associated with web services implementation that allows programs that run on different operating systems (such as Windows and Linux) to communicate with one another using HTTP and XML.

SOCKS

SOCKS is a protocol that allows an application inside the firewall to access resources on the global Internet.

Soft Handover

Soft handover is a category of handover procedures where the radio links are added and abandoned in such manner that the mobile always keeps at least one radio link established.

Soft key

A key below the phone’s display that performs whatever function is listed on the display.

SOHO - Small Office Home Office

This is a generic term regularly used to describe an environment or the equipment designed for either the Small Office or Home Office.

SoLSA - Support of Localized Service Area

Support of Localized Service Area allows a network operator to offer subscribers or groups of subscribers different services, different tariffs and different access rights depending on their geographical location.

SOR - Support of Optimal Routing

SOR (Support of Optimal Routing) is a network feature which enables the calls directed to a mobile subscriber to be routed directly to the mobile subscriber’s actual location, or to their forwarded to destination (instead of via the HPLMN (Home Public Land Mobile Network) or in the case of Late Call Forwarding via the VPLMN (Visited Public Land Mobile Network)).

SONET - Synchronous Optical Network

An interface standard for synchronous optical fiber transmission, applicable to the physical layer of the OSI (Open Systems Interconnection) reference model. SONET was developed by the Exchange Carriers Standards Association. SONET has a similar architecture to SDH ( Synchronous Digital Hierarchy).

Source Base Station

The Source BS (Base Station) is a term used to identify the BS (Base Station) that is in control of the call.

SP - Signalling Point

A Signalling Point is a node in the SS7 network. It is either the originating or terminating point.

SP - Subscriber Profile

SP is a generic term used to describe subscriber specific information which can be used by network entities in the course of service provision. The SP can contain information such as the user’s subscribed level of service and QoS entitlement.

Space diversity

A method of TX (Transmission) or RX (Reception), or both, in which the effects of fading are reduced by the simultaneous use of two or more antennas. Antennas should ideally be separated by one or more wavelengths.

Spam

Spam is the general title given to unwanted messages delivered to a victim. These messages are predominantly in the form of an email, although recent trends in spam delivery are also exploiting SMS , MMS and VoIP. It is said that the majority of traffic that passes across the Internet is actually spam, often distributed with the aid of a Botnet of some description. Although spam filters reduce the amount of unwanted spam an average user would receive, spammers are adopting a multitude of techniques to overcome these filters. In particular, with respect to email, spammers are utilizing a large variety of different attachment formats, including MP3.

SPC - Signalling Point Code

Codes used by the SS7 network for routing purposes which identify the originator or destination of an SS7 message.

SPD - Security Policy Database

A logical element of an IPSec implementation which holds the selectors required to determine whether a packet should be secured by IPSec.

Spectral density

Spectral density is the total power in the specified bandwidth divided by the specified bandwidth, usually expressed in Watts per Hertz.

Spectrum assignment

Government authorization for use of specific frequencies or frequency pairs within a given allocation, usually at a stated geographic location.

Speech synthesizer

A device that is capable of accepting digital or analogue data and developing intelligible speech sounds that correspond to the input data.

SPI - Security Parameters Index

The SPI (Security Parameters Index) is a pointer that references the session key and algorithms used to protect the data being transported. The index is defined during the SA (Security Association) establishment and described in the ESP (Encapsulating Security Protocol) or AH (Authentication Header) extension to the IP header.

SPNP - Support of Private Numbering Plan

Support of Private Numbering Plan enables a subscriber to use a PNP (Private Numbering Plan) for communication across one or more networks with mobile and fixed users within the digital cellular telecommunications system.

SPR - Subscription Profile Repository

The SPR is a logical database which contains subscriber related information related to policy and charging control. The SPR may be a subset of the HSS (Home Subscriber Server), providing information such as subscriber allowed services, permitted QoS and charging related information.

Spread spectrum

Jamming resistant and initially devised for military use, it is a telecommunications technique in which a signal is transmitted in a bandwidth considerably greater than the frequency content of the original information. Methods include frequency hopping, direct sequence spreading, time scrambling, and combinations of these techniques.

Spurious emission

Emission on a frequency or frequencies which are outside the necessary bandwidth. Spurious emissions include such things as harmonic emissions and inter modulation products.

SR - Scan Repetition

Scan Repetition is a Bluetooth mode used to identify how long the device will continue to scan for a page response message.

SR - Signalling Route

A predetermined path described by a succession of signalling points that may be traversed by signalling messages directed by a SP (Signalling Point) towards a specific destination point.

SR1 - Spreading Rate 1

A 1.2288Mcps chip rate based system. This utilizes a direct spread single carrier.

SR3 - Spreading Rate 3

A 3.6864Mcps chip rate based system. This utilizes three 1.2288Mcps carriers on the Forward CDMA Channel and the Reverse CDMA Channel uses a 3.6864Mcps direct spread carrier.

SR3 Frequencies

The three 1.2288Mcps carriers on the Forward CDMA Channel, identified as the lowest, centre and highest frequencies.

SRB - Signalling Radio Bearer

The RRC (Radio Resource Control) connection process will establish the RB (Radio Bearer) available for usage by RRC messages on the DCCH (Dedicated Control Channel) and CCCH (Common Control Channel). These Radio Bearers are identified as a SRB (Signalling Radio Bearer).

SRES - Signed Response

The variable generated in the AuC (Authentication Centre) and the MS (Mobile Station). A successful authentication occurs if the SRES value received from the AuC by the VLR (Visitor Location Register) matches that sent by the MS.

SRF - Specialized Resource Function

The set of functions that provides for the control and access to resources used in providing services. Typical functions of a SRF include the collecting of dialled digits and the playing of announcements.

SRI - Send Routing Information

SRI is a MAP message sent by the GMSC to the HLR to request routing information in order to route a call towards a mobile subscriber.

SRNC - Serving Radio Network Controller

When a RNC (Radio Network Controller) has a RRC (Radio Resource Control) connection with a UE (User Equipment), it is known as the SRNC for that UE. The SRNC is responsible for the user’s mobility within the UTRAN and is also the point of connection towards the CN (Core Network).

SRNS - Serving Radio Network Subsystem

There is one Serving Radio Network Subsystem for each UE (User Equipment) that has a connection to the UTRAN (UMTS Terrestrial Access Network). The Serving RNS controls the RRC (Radio Resource Control) connection between a UE and the UTRAN.

SRNS Relocation

The change of control from the SRNS (Serving Radio Network Subsystem) to another RNS (Radio Network Subsystem).

SRS - Signalling Route Set

The combination of all the permitted SR (Signalling Route) that may be used to pass signalling messages from a SP (Signalling Point) to a specific destination.

SRS - Sounding Reference Signal

This is a E-UTRA reference signal that is transmitted by the UE. It is then evaluated by the eNB to determine the channel quality and assist in resource scheduling.

SRTP - Secure Real time Transport Protocol

A mechanism which allows the user to encrypt the RTP packets being generated as part of a real time data session.

SRV - Server Record

A type of DNS record which provides information on a potential target server which may be able to handle a particular request/message.

SRVCC - Single Radio Voice Call Continuity

The network feature which allows ongoing calls to be seamlessly switched between 4G and 2G/3G access networks. SR-VCC is essential for VoLTE networks that do not benefit from ubiquitous LTE coverage (in which case 2G/3G coverage fills in the gaps).

SS - Supplementary Service

A service which modifies or supplements a basic telecommunication service. A supplementary service must be offered together with or in association with a basic telecommunication service.

SS-CSI - Supplementary Service Invocation Notification – CAMEL Subscription Information

SS-CSI is used to notify the CSE about the invocation of certain Supplementary Services. It includes: notification criteria – this indicates the supplementary services for which notifications will be sent. gsmSCF address.

SS7 - Signalling System No. 7

A CCS (Common Channel Signalling) system defined by the ITU-T (International Telecommunications Union-Telecommunication Standardization Sector). SS7 is used in many modern telecoms networks and provides a suite of protocols which enables circuit and non circuit related information to be routed about and between networks. The main protocols include MTP (Message Transfer Part) SCCP (Signalling Connection Control Part) and ISUP (ISDN User Part).

SSC - Session and Service Continuity

This 5G technique allows the service provider to set a specific SSC mode for a given PDU Session, which in turn will determine the flow of packets across the network in mobility scenarios. In particular, the different SSC modes will determine what type of IP address preservation is used as the device moves from one data network anchor to another.

SSCF - Service Specific Coordination Function

In the ATM (Asynchronous Transfer Mode) signalling layer the SSCF maps the requirements of the layer above to the requirements of SSCOP (Service Specific Connection Oriented Protocol).

SSCOP - Service Specific Connection Oriented Protocol

In the ATM (Asynchronous Transfer Mode) signalling layers, SSCOP provides mechanisms for the establishment and release of connections and the reliable exchange of signalling information between signalling entities.

SSD - Shared Secret Data

A key of length 128bits, stored in the MS (Mobile Station) and known by the BS (Base Station). The SSD is a concatenation of two 64bit subsets: SSD_A , used in the authentication procedures, and SSD_B , used along with other parameters to generate the encryption mask and private long code.

SSDT - Site Selection Diversity Transmission

The intention with Site Selection Diversity Transmission is that only the primary cell sends the data part of the downlink data channel, while the control part is sent by the BS (Base Station).

SSF - Service Switching Function

The set of processes in an IN (Intelligent Network) that provide the communication path for interaction between a CCF (Call Control Function) and a SSF (Service Control Function).

SSH - Secure Shell

SSH is a security mechanism which allows remote configuration of network devices through the establishment of a secure channel between the target device and the configuring entity. SSH was designed as a replacement for the less secure TELNET protocol.

SSID - Service Set Identifier

The Service Set Identifier or Network Name is used within IEEE 802.11 networks to identify a particular network. It is usually set by the administrator setting up the WLAN (Wireless Local Area Network) and will be unique within a BSS (Basic Service Set) or ESS (Extended Service Set). The SSID may be broadcast from an AP (Access Point) within the wireless network to enable Stations to determine which network to Associate with. However, this feature should be disabled as it may assist hackers or wardrivers in gaining access to a private network.

SSL - Secure Sockets Layer

The SSL protocol runs above TCP/IP and below higher-level protocols such as HTTP (Hypertext Transport Protocol) or IMAP (Internet Message Access Protocol). It uses TCP/IP on behalf of the higher-level protocols, and in the process allows an SSL enabled server to authenticate itself to an SSL enabled client.

SSM - Source Specific Multicast

In normal IP multicast operation, numerous entities are permitted to be the source of a multicast traffic stream. SSM describes the notion of one source of traffic associated with the multicast group, as opposed to numerous. This is particularly relevant for IPTV services, where the source for the multicast group would be an individual media server. As such, when subscribers choose a particular channel, they will join the multicast group for that channel but also specify the source IP address of the appropriate media server.

SSN - Sub System Number

The SCCP (Signalling Connection Control Part) function uses the SSN to determine the local subsystem.

SSP - Service Switching Point

The physical entity in an IN (Intelligent Network) that implements the service switching function.

SSRC - Station Short Retry Counter

The Station Short Retry Counter is used in WiFi during error recovery procedures. The counter is incremented each time a frame less than the RTS (Request To Send) threshold is received in error. This in turn increases the contention window maximum value.

SSS - Secondary Synchronization Signal

The E-UTRA Secondary Synchronization Signal enables the mobile to determine the cell and cell group on which it is decoding the downlink radio transmission.

SST - Slice/Service Type

In relation to Network Slicing, the SST will define the expected behaviour of the Network Slice in terms of specific features and services. Standardized SST values include eMBB (enhanced Mobile Broadband), URLLC (Ultra Reliable Low Latency Communications) and MIoT (Massive Internet of Things).

ST - Signalling Terminal

A signalling terminal is the termination of a SL (Signalling Link) at a SP (Signalling Point). Each end of the signalling link employs a signalling terminal.

Stack Smashing

Stack Smashing is the technique used to trick a computer into executing arbitrary code by forcing a buffer overflow.

Standby State

This is a GPRS state which is similar to the idle state in GSM and UMTS. A mobile will perform a RAU (Routing Area Update) when necessary in the standby state.

Standby Time

The amount of time a subscriber can leave a fully charged handset turned on to receive incoming calls before the phone will discharge the batteries.

Standing wave

A standing wave may be formed when a wave is transmitted into one end of a transmission line and is reflected from the other end by an impedance mismatch.

Star topology

A network topology in which peripheral nodes are connected to a central node, which rebroadcasts all transmissions received from any peripheral node to all peripheral nodes on the network, including the originating node.

Station

A term used to describe any device that contains an IEEE 802.11 conformant MAC (Medium Access Control) and physical layer interface to the wireless medium. In practice, this may represent a laptop computer or PDA (Personal Digital Assistant) fitted with an IEEE 802.11 data card.

STB - Set Top Box

The STB is an integral part of cable based TV services. Located at the customer premises, the device is responsible for demodulating, decrypting and processing MPEG-2 or MPEG-4 based TV content, in addition to providing the capability for the user to utilize interactive services. Newer IPTV systems use the same terminology, although in this case the term STB is being phased out in favour of the Home Gateway.

STC - Space Time Coding

This is a radio technique used in many mobile systems to provide diversity and combat interference. It typically involves transmitting copies of the same data across multiple spaced antennas at different times, enabling the receiver to combine and find all the original data.

STiMi - Satellite and Terrestrial Interactive Multiservice

STiMi was developed by the China based company TiMiTech, which is actually part of the Chinese Academy of Broadcasting science. STiMi is actually a hybrid Mobile TV technology which utilizes both satellite and terrestrial broadcast to ensure optimal coverage. As such, STiMi is considered to be a Fill In service, whereby the predominant delivery mechanism is satellite which is complimented by terrestrial broadcast in areas of poor coverage.

STM - Synchronous Transport Module

The basic transport frame of an SDH network, operating at a minimum of 155Mbps (STM-1). The payload of an STM-1 frame can vary, supporting potentially 63 E1 trunks, a combination of E1 to E3 bearers, a single E4 trunk or alternatively IP data. The STM-1 frame is comprised of Overhead blocks, Payload blocks (Virtual Containers) and Pointers, the ratio of each depending on the initial payload to be transported. STM-1 can be multiplexed to create higher order STM, for example an STM-4 would be 4 x STM-1 and an STM-16 would be 4 x STM-4. SDH (Synchronous Digital Hierarchy) uses the following STM (Synchronous Transport Modules) and rates: STM-1 (155Mbps), STM-4 (622Mbps), STM-16 (2.5Gbps), and STM-64 (10Gbps).

STM-1 - Synchronous Transfer Module 1

The lowest data rate for an SDH system, operating at 155Mbps.

STN-SR - Session Transfer Number for SRVCC

A routing number used to identify an SCC AS or ATCF as part of and SR-VCC handover procedure.

Store-and-forward

Communications systems in which messages are received at intermediate routing points and stored, and then transmitted, to the next routing point or to the ultimate recipient.

STP - Shielded Twisted Pair

A term used to describe a twisted pair cable which has a protective radiation screen to reduce outside interference.

STP - Signalling Transfer Point

In a common channel signalling network a STP (Signalling Transfer Point) provides for the transfer of signalling messages from one SL (Signalling Link) to another.

STR - Session Termination Request

This Diameter message is used to tear down an ongoing session. For example, upon detection of the SIP BYE and 200 OK, the P-CSCF will send the STR message to the PCRF in order to ensure the Dedicated EPS Bearer is removed in the LTE network.

Stream Cipher

A Stream Cipher is a symmetric or secret-key encryption algorithm that encrypts a single bit at a time. With a Stream Cipher, the same plaintext bit or byte will encrypt to a different bit or byte every time it is encrypted (the plaintext bit/byte can also, of course, be encrypted to the same value).

STS - Space Time Spreading

A method by which all forward link channel symbols are transmitted on multiple antennas.

STUN - Simple Traversal of UDP through Network Address Translation

STUN is an IETF (Internet Engineering Task Force) based protocol defined in RFC 3489. STUN is used as a mechanism when overcoming the problem of NAT (Network Address Translation) traversal for protocols such as SIP (Session Initiation Protocol).

SU-MIMO - Single User – MIMO

This is a MIMO term relating to how the data is transmitted. SU-MIMO, as it’s name suggests, defines a single user being scheduled, i.e. maximizing the data rate. In contrast, MU-MIMO (Multi-User MIMO) shares the resources to support more users.

SUA - SCCP User Adaptation

SUA enables the transport of any native SCCP (Signalling Connection and Control Part) user signalling such as TCAP (Transaction Capabilities Application Part) or RANAP (Radio Access Network Application Part). Like SCCP it provides the user with both connectionless and connection orientated services as well as network management functionality. SUA like the other adaptation layers requires the services of SCTP (Streaming Control Transmission Protocol) to provide reliable transfer of user messages.

Sublayer

The term Sublayer identifies a protocol layer that resides within another protocol layer or sublayer.

Subnet address

The Subnet address is an extension that allows users in a network to use a single IP network address for multiple physical subnetworks.

Subscribed QoS

In GPRS and UMTS , the network will not grant a QoS (Quality of Service) greater than that to which the user has subscribed. The QoS profile subscription parameters are held in the HLR (Home Location register) and forwarded to the SGSN (Serving GPRS Support Node).

Subscriber

A person who is party to a contract with the provider of public telecommunication services.

Superframe

A hierarchical number used to indicate multiple radio frames. It is used by the mobile to ascertain where control and traffic channels may appear on the radio interface.

Supplemental Channel

An optional portion of a Forward and Reverse Traffic channel which operates with the Fundamental Channel to provide higher data rate services.

Supplemental Code Channel

An optional portion of a Forward and Reverse Traffic Channel which operates with the Fundamental Channel to provide higher data rate services. The Supplemental Channel is transmitted on the Forward or Reverse CDMA Channel. This channel allows a combination of primary data, secondary data, or both (not signaling information) to be transmitted.

Surface wave

A wave that is guided along the interface between two different media or by a refractive index gradient.

Surface Web

The Surface Web equates to approximately 3% of the World Wide Web and can be described as the part of the Web that is indexed and referenced by search engines and freely accessible via a web browser. In other words, websites of the Surface Web do not require a username/password in order to access the site.

SVC - Switched Virtual Circuit

A generic term for any switched communications medium. In a network, a SVC (Switched Virtual Circuit) is a temporary virtual circuit that is established and maintained only for the duration of a data transfer session.

Switch - PSTN Telephony Switch

PSTN Switches were originally introduced to improve efficiency of the telephony network and negate the requirement for every telephone in the network to be directly connected through dedicated connections. They enable the establishment and termination of voice calls to be enabled with networks external to the PSTN, e.g. in mobile networks the PSTN Switch will connect to the GMSC.

SwMI - Switching and Management Infrastructure

In a TETRA system, the SwMI includes the base stations, switches and controllers. A TETRA mobile registers and communicates with the SwMI.

SWP - Single Wire Protocol

Defined by ETSI , the SWP is a bit orientated point-to-point communication protocol that exists between the NFC device and a SIM. It operates in full duplex mode by transmitting two signals S1 and S2 in the voltage and current domain respectively.

Sxa Interface

The Sxa interface carries signalling information between the SGW-C (Serving Gateway Control plane function) and the SGW-U (Serving Gateway User plane function) to control the functionality of the SGW-U.

Sxb Interface

The Sxb interface carries signalling information between the PGW-C (PDN Gateway Control plane function) and the PGW-U (PDN Gateway User plane function) to control the functionality of the PGW-U.

Sxc Interface

The Sxc interface carries signalling information between the TDF-C (Traffic Detection Function Control plane function) and the TDF-U (Traffic Detection Function User plane function) to control the functionality of the TDF-U.

Sync Channel

Sync Channel Identified as code channel 32 in the Forward CDMA Channel which transports the synchronization message to the MS (Mobile Station).

Sync Channel Superframe

Sync Channel Superframe Identifies an 80ms interval which consists of three Sync Channel frames, each 26.66ms in length.

Synchronization

A state of simultaneous occurrences of significant instants among two or more signals.

Synchronization Code

In digital systems, a sequence of bits introduced into a transmitted signal to achieve or maintain synchronization.

Synchronous Transmission

Digital transmission in which the time interval between any two similar significant instants in the overall bit stream is always an integral number of unit intervals.

System

A system is a fixed, cellular or wireless communications service that covers a geographic area.

System Area

The System Area is defined as the area accessible to the mobile. Interworking of several networks enables the mobile to access visiting networks and thus increases the system area.

T Carrier

North American term for the TDM (Time Division Multiplexing) digital transmission hierarchy. Includes T1 – 1.544Mbps, T1-C – 3.152Mbps, T2 – 6.312Mbps, T3 – 44.736Mbps, T4 – 274.176Mbps.

T Interface

For basic rate access in an ISDN (Integrated Services Digital Network) environment, a user to network interface reference point that is characterized by a four wire, 144Kbps (2B+D) user rate.

T-ADS - Terminating Access Domain Selection

Term given to the process which takes place at an SCC-AS to determine whether or not MT call signalling should be sent to the PS or CS domain in order to contact the called party.

T-BCSM - Terminating Basic Call State Model

A term used in an IN (Intelligent Networks) it identifies the terminating half of the BCSM (Basic Call State Model).

T-CSI - Terminating – CAMEL Subscription Information

CAMEL operation requires additional CSI (CAMEL Subscription Information) to be included as part of a mobile subscriber’s subscription information in the HLR. This will be forwarded to the appropriate VLR when the mobile attaches and moves around the network. There are two types of CSI these are O-CSI (Originating – CAMEL Subscription Information) and T-CSI (Terminating – CAMEL Subscription Information). The later phases of CAMEL include many variations of CSI.

T-DMB - Digital Multimedia Broadcasting (Terrestrial)

T-DMB (Terrestrial) is a Mobile TV technology, developed in Korea from the European Eureka 147 DAB (Digital Audio Broadcasting) standard (Satellite DMB is also available but is a completely different technology). T-DMB relies on DAB technology at the physical layer, using OFDM for transmission. Like DVB-H , T-DMB uses MPEG-2 -TS (MPEG-2 Transport Stream) to carry audio and video. However, where DVB-H encapsulates media using IP, T-DMB encodes audio and video using MPEG-4 and sends the encoded data directly to the MPEG-2-TS layer.

TA - Terminal Adapter

An interfacing device employed at the R reference point in an ISDN environment that allows connection of a non ISDN terminal at the physical layer to communicate with an ISDN network.

TA - Timing Advance

In order to get TDMA (Time Division Multiple Access) schemes to work, the time-frames from each mobile must be synchronized when received by a base station. This synchronization is achieved by using the concept of TA (Timing Advance). The degree of synchronization is measured by the base station on the uplink, by checking the position of the TSC (Training Sequence Code). This training sequence is mandatory in all frames transmitted from the mobile. From these measurements, the base station can calculate the TA and send this information to the mobile.

TA - Tracking Area

Am area of LTE radio coverage which is comprised of a collection of LTE cells. If an LTE mobile is in an idle state, its current TA should be known to the MME (or TAI List, if in use).

TAC - Tracking Area Code

An element of the TAI which serves to uniquely identify the Tracking Area.

TAC - Type Approval Code

Type Approval Code is the first six digits of the IMEI (International Mobile Equipment identity). This code identifies the country in which type approval was sought for the phone, and the approval number. The first two digits of the TAC represent the country of approval.

TACS - Total Access Communication System

A cellular mobile telephone standard originally used in the UK. TACS operated on the 900MHz frequency band.

TAD - Traffic Aggregate Description

The Traffic Aggregate Description specifies the aggregation of one or more packet filters and includes their related parameters. The TAD is utilised by a mobile device within the LTE network in order to inform the network of the packet filters to be used for traffic mapping to the correct EPS bearer contexts. The TAD is created in the same format as the TFT and can be seen in the Bearer Resource Allocation Request or Bearer Resource Modification Request messages.

TADIG - Transferred Account Data Interchange Group

TADIG is the group responsible for ensuring that billing for roaming is correctly conducted within mobile networks.

TAI - Timing Advance Index

The MS (Mobile Station) performing uplink or downlink packet transfer, will receive a packet uplink or downlink assignment message. This message will contain the MS assigned TAI and the PTCCH (Packet Timing Control Channel). The TAI specifies which PTCCH subchannel is to be used by the MS.

TAI - Tracking Area Identity

The Tracking Area identity is the identity used to identify tracking areas. The Tracking Area Identity is constructed from the MCC (Mobile Country Code), MNC (Mobile Network Code) and TAC (Tracking Area Code).

Tails

Functioning as a Linux Live distribution, Tails is a standalone operating system which features a variety of tools to assist with anonymity. This includes mandatory use of Tor for anonymous web browsing, as well as applications to secure instant messaging, provide file encryption and protect against keystroke logging, amongst many others.

TALI - Transport Adapter Layer Interface

Part of SIGTRAN (Signalling Transport) the TALI (Transport Adapter Layer Interface) is the proposed interface which provides TCAP (Transaction Capability Application Part) ISUP (ISDN User Part) and MTP (Message Transport Protocol) messaging over TCP/IP.

Talktime

The length of time a phone can be used to engage in a conversation. Usually stated in minutes.

TAP3 - Transferred Account Procedure v3

The TAP standard from the GSM Association enables service providers to exchange billing information on roamed subscribers.

Target Base Station

A Target BS (Base Station) is a term used to identify any BS (Base Station), excluding the Source BS (Base Station), that supports a call.

Tariff

The set of charges that apply depending to a specific call plan.

TAS - Telephony Application Server

The TAS which is used within the IMS to facilitate VoLTE call establishment procedures, as well as support supplementary services such as Calling Party ID, Call Transfer and Call Barring.

TAU - Tracking Area Update

The LTE UE detects a change to a new TA (Tracking Area) by decoding the TAI (Tracking Area Identity) broadcast on the serving cell that it has just selected. This is done by comparing this value with the list of TAI that the UE has registered in the network. The TAU procedure is performed due to a variety of reasons, such as TA updating, combined TA/LA updating, combined TA/LA updating with IMSI attach and periodic updating.

TB - Terabyte

A terabyte is a measure of computer storage capacity and is 240 bytes or approximately a thousand billion bytes / a thousand gigabytes.

TBCP - Talk Burst Control Protocol

TBCP as defined by the OMA (Open Mobile Alliance) uses the application extension features of RTCP (RTP Control Protocol) in order to invoke floor control within the POC (Push to talk Over Cellular) environment. Typical messages include: Talk Burst Granted, Talk Burst Request Message, Talk Burst Deny Message, Talk Burst Release Message, Talk Burst Taken, Talk Burst Idle.

TBF - Temporary Block Flow

A Temporary Block Flow is a physical connection used by the two RR (Radio Resource) entities to support the unidirectional transfer of LLC (Logical Link Control) PDU (Protocol Data Unit) on packet data physical channels. A TBF is temporary and is maintained only for the duration of the data transfer, i.e. until there are no more RLC (Radio Link Control) / MAC (Medium Access Control) blocks to be transmitted.

TBS - Transport Block Set

The Transport Block is defined as a set of Transport Blocks, which are exchanged between MAC and L1 at the same time instance using the same transport channel. A high rate transport channel carries more information and therefore potentially carries more transport blocks.

TCAP - Transaction Capabilities Application Part

TCAP is an SS7 protocol which is designed to facilitate the establishment of dialogues between SS7 nodes in the network. These dialogues allow physical nodes running separate subsystems to communicate directly with one another, providing a multiplexing/demultiplexing service akin to UDP, TCP etc. For example, a single node may be running MAP (Mobile Application Part) and CAP (CAMEL Application Part) as separate subsystems. Two separate TCAP dialogues can be established to the same physical node, with the traffic for each subsystem separated by the appropriate dialogue.

TCH/F - Traffic Channel Full Rate

The Full Rate channel in GSM is identified as a 22.8Kbps gross bit rate channel. This channel is bidirectional enabling the transfer of speech or circuit switched data. Signalling associated with this traffic channel will be carried on either the SACCH (Slow Associated Control Channel) or the FACCH (Fast Associated Control Channel). The latest releases of GSM include EDGE (Enhanced Data rates for Global Evolution) functionality which increases the gross rate.

TCLAS - Traffic Classification

The term TCLAS is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancement. This optional information element contains a set of parameters to identify incoming frames with a particular traffic stream and is thus linked to a particular TSPEC.

TCP - Transmission Control Protocol

TCP is a Transport Layer protocol which provides reliable, sequential delivery of higher layer application data. This is achieved through a segmentation process, whereby the transmission and reception of segments is monitored in order to detect and resend dropped packets. TCP also adds port addressing for multiplexing/demultiplexing of higher layer applications towards the same destination IP address.

TCP/IP - Transmission Control Protocol/Internet Protocol

The TCP/IP Suite includes, but is not limited to, protocols such as TCP (Transmission Control Protocol), IP (Internet Protocol), UDP (User Datagram Protocol), ICMP (Internet Control Message Protocol), FTP (file Transfer Protocol, and SMTP (Simple Mail Transfer Protocol).

TCS - Telephony Control protocol Specification

The Bluetooth Telephony Control protocol Specification defines call related signalling between devices (establishment of speech and data calls). It also controls the device mobility management procedures.

TCTF - Target Channel Type Field

The UMTS air interface uses the Target Channel Type Field to provide identification of the logical channel class on the FACH (Forward Access Channel) and RACH (Random Access Channel) transport channels. TCTF indicates if BCCH (Broadcast Control Channel), CCCH (Common Control Channel), CTCH (Common Traffic Channel), SHCCH (Shared Channel Control Channel) or dedicated logical channel information is being transported.

TD-CDMA - Time Division

UMTS TDD (Time Division Duplex) mode operates in the unpaired portion of the 3G spectrum. TDD uses a combined time division and CDMA scheme called TD-CDMA.

TDD - Time Division Duplex

In a Time Division Duplex system a common carrier is shared between the uplink and downlink, the resource being switched in time. Users are allocated one or more timeslots for uplink and downlink transmission. The main advantage of TDD operation is that it allows asymmetric flow which is more suited to data transmission.

TDF-C - Traffic Detection Function Control plane function

The TDF-C controls the functionality performed by the assigned TDF-U (Traffic Detection Function User plane function) when control and user plane separation is in place. It is responsible for selecting and controlling the TDF-U which will be conducted based upon PCC (Policy and Charging Control) rules, in order to perform application detection and reporting of detected application and the associated service data flow descriptions to the PCRF (Policy Charging and Rules Function).

TDF-U - Traffic Detection Function User plane function

The TDF-U is located at the ingress and egress point to a PDN (Packet Data Network) such as the Internet when control and user plane separation is in place. Under the control of a TDF-C (Traffic Detection Function Control plane function) the TDF-U assists with bearer and APN (Access Point Name) policing, service data flow traffic detection, application detection, deep packet inspection and event reporting.

TDM - Time-Division Multiplexing

Digital Multiplexing technique in which two or more apparently simultaneous channels can be combined to form a bit stream by interleaving bits or bit words from different channels.

TDMA - Time-Division Multiple Access

A communications technique that uses a common channel for communications among multiple users by allocating each a unique time slot.

TDOA - Time Difference On Arrival

TDOA is a technique used in mobile networks to allow the network to obtain location information for a particular subscriber. The technique is often used to support the stringent location accuracy requirements associated with E911, which mandate that the network is able to identify the location of a subscriber to a specific degree of accuracy. TDOA bases its measurements on the time it takes for a radio signal to propagate between the mobile phone and the cell site. Receivers at the cell site termed LMUs (Location Measurement Units) will take the time measurements which can then be turned into an estimated distance. Providing the service provider has the measurements from several different cell sites surrounding the subscriber (three or more), a technique termed multilateration can be used to pinpoint the location to within an accuracy of approximately 50m (although this figure can vary).

TDP - Trigger Detection Point

There are two ways in which a DP may be armed. These are: Statically – a statically armed DP is known as a TDP (Trigger Detection Point) this is always armed within the BCSM. Dynamically – a dynamically armed DP is known as an EDP (Event Detection Point). This will be armed by the SCF (Service Control Function) within the context of an IN service.

TE - Traffic Engineering

TE refers to the practice of engineering routes through typically IP based networks which are designed to cater for particular types of traffic. For example, real time traffic will require a route through a network which utilizes low latency links, therefore TE would allow that route to be pre-established prior to the traffic passing through the network.

TE - Transit Exchange

A Transit Exchange unlike a LE (Local Exchange), does not have subscribers connected to it and therefore does not act as a source or sink for traffic in the network. It only collects and redirects the 

TE-LSP - Traffic Engineered Label Switched Path

TE-LSP is a term used in MPLS to describe a preconfigured LSP whose characteristics for latency, induced jitter, number of hops etc match the criteria to successfully support a particular traffic type.

TEI - Terminal Endpoint Identifier

A unique identifier given to each device or terminal on an ISDN S or T interface.

TEID - Tunnel Endpoint Identifier

The TEID unambiguously identifies a tunnel endpoint in the receiving GTP-U (GPRS Tunnelling Protocol – User) or GTP-C (GPRS Tunnelling Protocol – Control) protocol entity. The receiving side of a GTP tunnel locally assigns the TEID value for the transmitting side to use. The TEID values are exchanged between tunnel endpoints using GTP-C messages (or RANAP (Radio Access Network Application Part) in the UTRAN (UMTS terrestrial Radio Access Network)).

Telecommunication

Any transmission, emission, or reception of signs, signals, writing, images and sounds or intelligence of any nature by wire, radio, optical or other electromagnetic systems.

Telecommunication service

Service offered by a network or service provider to its customers in order to satisfy a specific telecommunication requirement. Telecommunication services are divided into two broad families: bearer services and teleservices.

Telecommunications network

Transmission systems and, where applicable, switching equipment and other resources which permit the conveyance of signals between defined termination points by wire, radio, optical or other electromagnetic means.

Teleconference

The live exchange of information among persons and machines remote from one another but linked by a telecommunications system.

Telemetry

The use of telecommunication for automatically indicating or recording measurements such as stock levels, weather, and road traffic information.

Telephone

A user end instrument that is used to transmit and receive voice frequency signals.

Telephone number

The unique network address that is assigned to a telephone user, i.e., subscriber, for routing telephone calls.

Telephony

A form of telecommunication set up for the transmission of speech or, in some cases, other sounds.

Teleservice

The type of telecommunication service that provides the complete capability, including terminal equipment functions, for communication. Examples of a teleservice include speech, fax etc.

Telnet

Telnet is a protocol to enable access to remote hosts, assuming relevant permissions have been granted. Telnet allows remote log on with whatever privileges may have been granted to the specific application and data on that host.

TEMPORARY_OFFSET

This specifies the offset applied to the H and R criteria for a neighbouring cell for the duration of PENALTY_TIME.

Terminal portability

The ability for customers to transfer their terminal apparatus (e.g. a telephone) to another public network without any loss of interoperability.

Terrestrial Radio Communication

Any radio communication other than space radio communication or radio astronomy.

TETRA - Terrestrial Trunked Radio

An open digital trunked radio standard defined by ETSI ( European Telecommunications Standards Institute ).It is currently being used by the emergency services to replace existing PMR (Private Mobile Radio) systems.

TFC - Transport Format Combination

The physical layer multiplexes one or several Transport Channels onto a Coded Composite Transport Channel. These Transport Channels each have defined transport formats (maybe from a Transport Format Set) which are applicable. However, at a given point of time, not all combinations of transport channels and their associated formats are permitted, hence a subset is defined. The Transport Format Combination is one of the subset, which identifies the transport channels with their chosen format that will make up the Coded Composite Transport Channel.

TFCI - Transport Format Combination Indicator

This is a representation of the current TFC (Transport Format Combination) being used. The TFCI is transferred across the air interface and allows the receiving layers to identify the current valid Transport Format Combination and hence, how to decode, de-multiplex and deliver the received data on the appropriate Transport Channels.

TFCS - Transport Format Combination Set

The Transport Format Combination Set is defined as a set of Transport Format Combinations on a Coded Composite Transport Channel.

TFI - Temporary Flow Identity

Each TBF (Temporary Block Flow) is assigned a TFI (Temporary Flow Identity) by the network. The mobile station shall assume that the TFI value is unique among concurrent TBF in the same direction (uplink or downlink) on all PDCH (Packet Data Channel) used for the TBF.

TFI - Transport Format Indicator

The Transport Format Indicator indicates the local UMTS air interface transport format to be used for the transmission time interval.

TFO - Tandem Free Operation

Tandem Free Operation is the configuration of a connection with two transcoders that support the TFO protocol and whose external coding schemes are compatible, thus enabling compressed speech to pass between them.

TFRI - Transport Format and Resource Indicator

This includes information about the dynamic part of the HS-DSCH transport format, including transport block set size and modulation scheme. The TFRI also includes information about the set of channelization codes onto which HS-DSCH is mapped in the corresponding HS-DSCH transmission. The number of bits defined are: – Channelization-code set -7 bits. – Modulation scheme – 1 bit. – Transport-block size – 6 bits.

TFS - Transport Format Set

The Transport Format Set is the set of different Transport Formats associated to a Transport Channel.

TFT – GPRS - Traffic Flow Template (GPRS)

The Traffic Flow Template is used by GGSN (Gateway GPRS Support Node) to discriminate between different user payloads. The TFT incorporates packet filters such as QoS (Quality of Service), PDP Context and security. Using the packet filters the GGSN maps the incoming datagrams into the correct PDP Context. Note: The use of a TFT allows multiple PDP contexts to be associated with the same PDP address.

TFT – LTE - Traffic Flow Template (LTE)

In LTE, TFTs are installed at the mobile and at the P-GW in order to determine if a particular traffic stream needs to traverse a particular EPS bearer. As such, when a Dedicated EPS bearer is established, an uplink TFT is installed at the handset and a downlink TFT is installed at the P-GW. The TFT itself contains packet filters which are based on potential packet characteristics such as IP address and port.

TFTP - Trivial File Transfer Protocol

An Internet software utility for transferring files that is simpler to use than the FTP (File Transfer Protocol) but less capable. It is used where user authentication and directory visibility are not required.

TFTP - Trivial File Transfer Protocol

An Internet software utility for transferring files that is simpler to use than the FTP (File Transfer Protocol) but less capable. It is used where user authentication and directory visibility are not required.

TGRP - Transmission Gap Repetition Period

In E-UTRA a mobile may require a measurement gap in order to monitor neighbouring Inter-RAT or Inter Frequency cells. The TGRP is one of many parameters which is used by the eNB to schedule the measurement gap.

Thermal noise

The noise generated by thermal agitation of electrons in a conductor. The noise power, P, in watts, is given by P = kTB , where k is Boltzmann’s constant in joules per kelvin, T is the conductor temperature in kelvins, and B is the bandwidth in Hertz.

Thermal radiation

Electromagnetic radiations emitted from a heat or light source as a consequence of its temperature; it consists essentially of ultraviolet, visible, and infrared radiation.

THF - Tremendously High Frequency

Frequencies from 300GHz to 3000GHz.

THIG - Topology Hiding Inter-working Gateway

Signalling emanating from the home IMS (IP Multimedia Subsystem) may be protected through topology hiding. This increases the robustness of the IMS in terms of security. Since functions outside the trust domain of the home IMS have no view of the URI (Uniform Resource Identifiers) that are used to address functions such as the S-CSCF (Serving – Call Session Control Function) or MGCF (Media Gateway Control Functions). The basic process in which topology hiding is implemented is through the encryption of any URI that relates to functions within the home IMS, in SIP signalling messages leaving the network. These include: Via – used to route responses relating to a specific request; Route – indicating the path subsequent signalling messages should take; Record Route – a list of SIP agents that have proxied the specific message.

Throughput

The number of bits, characters, or blocks passing through a data communication system, or portion of that system in a given time.

THz - Terahertz

A unit denoting one trillion Hertz.

TI - Transaction Identifier

A transaction identifier is used to distinguish multiple bidirectional message flows for a given users connection and a given SAP (Service Access Point). Such a message flow is called a transaction.

TIA - Telecommunications Industry Association.

A trade group representing manufacturers and suppliers of communications and information technology products. TIA is a standards developing organization accredited by ANSI (American National Standards Institute).

TID - Tunnel Identifier

In GPRS Release 97 the TID field unambiguously identifies a tunnel between a GGSN (Gateway GPRS Support Node) and a SGSN (Serving GPRS Support Node). The TID field includes the NSAPI (Network Service Access Point Identifier) and IMSI (International Mobile Subscriber Identity) values.

TIM - Traffic Indication Map

The TIM can be defined as an information element found within an IEEE (Institute of Electrical and Electronics Engineers) 802.11 Beacon Message. It is used by networks supporting the Power Save Poll procedure and includes a bitmap reference specific stations for which data is being held at the AP (Access Point).

Time diversity

Transmission in which signals representing the same information are sent over the same channel at different times.

Timer Based Registration

A method by which the MS (Mobile Station) will register whenever a counter reaches a defined value. The counter is incremented every 80ms. The smaller the counter, the more regular the registrations, however this impacts on the mobile’s battery life.

Timing Offset

The delay of the received signal relative to the expected signal from a MS (Mobile Station) at zero distance under static channel conditions with zero timing advance. For example, for a mobile with a round trip propagation delay of P symbols, but with a timing advance of T symbols, the reported timing offset will be P-T quantized to the nearest symbol. For GPRS the mobile timing offset is not reported.

TIN - Temporary ID used in Next update

In E-UTRA the UE may have valid parameters from both the MME (Mobility Management Entity) and from SGSN (Serving GPRS Support Node). This parameter identifies the UE identity to be indicated in the next Routing Area Update Request or Tracking Area Update Request message.

TIP - Terminating Identification Presentation

TIP is a supplementary service associated with the 3GPP’s MMTel service framework. When TIP is active, the Calling Party will receive identification information relative to the Called Party once the IMS communication has been accepted by both parties.

TIPHON - Telecommunications and Internet Protocol Harmonization Over Networks

TIPHON was an initiative put forward by ETSI , designed to support a market for voice communication and related multimedia aspects between users of IP based networks and users of circuit switched networks. TIPHON was replaced in 2003 by the TISPAN initiative.

TISPAN - Telecommunications and Internet converged Services and Protocols for Advanced Networks

TISPAN is an ETSI (European Telecommunications Standards Institute) initiative which is tasked with developing standards for next generation telecommunications networks, particularly with respect to fixed line IP based access networks. As such, TISPAN employs the 3GPP IMS (IP Multimedia Subsystem) core architecture and a fixed line IP-CAN (with DSL the prime example). Key functions of the TISPAN architecture include the RACS (Resource and Admission Control Subsystem) and NASS (Network Attachment Sub System).

TKIP - Temporal Key Integrity Protocol

This is a security protocol used within the IEEE 802.11i specifications for WiFi networks. TKIP introduces a sophisticated key generation function which encrypts every data packet sent over the wireless medium (air interface) with its own unique encryption key. This increases the complexity of decoding the keys by reducing the amount of data available to the hacker, that has been encrypted using a particular key.

TLD - Top Level Domain

A Top Level Domain describes the tier of domain names after the root. There are two different types of TLD, the gTLD and the ccTLD. gTLD stands for generic Top Level Domain, and ccTLD stands for country code Top Level Domain. Examples include. com ,.org, and.net. etc.

TLLI - Temporary Logical Link Identifier

The Temporary Logical Link Identifier provides a signalling address for communication between the MS (Mobile Station) and the SGSN (Serving GPRS Support Node). Three main types of TLLI exist: Local TLLI – used under normal operation between the mobile and the serving SGSN; Foreign TLLI – may be used when crossing a RA (Routing Area) boundary; Random TLLI – used for initial access or when the mobile does not possess one of the above.

TLS - Transport Layer Security

TLS (Transport Layer Security) is a protocol such as SSL (Secure Sockets Layer) that normally provides confidentiality, authentication, and integrity for stream-like connections such as those provided by TCP (Transmission Control Protocol). It is typically used to secure HTTP (Hypertext Transport Protocol) connections and has been standardized by the IETF (internet Engineering Task Force).

TLV - Tag Length Value

TLV is a format for holding information within a data communication protocol.

TME - Transfer Mode Entity

In UMTS the Transfer Mode Entity handles the mapping between the different entities inside the RRC (Radio Resource Control) layer and the SAP (Service Access Points) provided by RLC (Radio Link Control).

TMGI - Temporary Mobile Group Identity

The TMGI is a radio resource efficient mechanism for identifying an MBMS Bearer Service (as opposed to using the IP Multicast Address and Access Point Name). Initially allocated by the BM-SC (Broadcast Multicast Service Center), the TMGI for a specific MBMS multicast service is provided to the mobile during the MBMS Multicast Service Activation procedure.

TMN - Telecommunications Management Network

A management network that interfaces with a telecommunications network at several points in order to receive information from, and to control the operation of, the telecommunications network.

TMSI - Temporary Mobile Subscriber Identity

In order to ensure subscriber identity confidentiality the VLR (Visitor Location Register) and SGSN (Serving GPRS Support Node) may allocate TMSI (Temporary Mobile Subscriber Identities) to visiting mobile subscribers. The VLR and SGSN must be capable of correlating an allocated TMSI with the IMSI (International Mobile Subscriber Identity) of the MS (Mobile Station) to which it is allocated. A MS may be allocated two TMSI, one for services provided through the VLR, and the other known as the P-TMSI (Packet TMSI) for services provided through the SGSN.

TMSI Zone

TMSI Zone The TMSI Zone Identifies an area in which the TMSI parameter is unique

TNA - Trusted Node Authentication

TNA is an IMS authentication mechanism which allows a trusted node to register/authenticate a user that has connected via the circuit switched domain. As such, the MSC (Mobile Switching Centre) would be a good example of a trusted node.

TOA - Time Of Arrival

The reference point for signal arrival time, TOA (Time Of Arrival) is defined as the start point of a time slot. Used for LCS (LoCation Services), and similar to E-OTD (Enhanced – Observed Time Difference) in that the time difference of the signal arriving at different base stations is used to calculate the location of a mobile device. The difference between TOA and E-OTD is that no overlay network is needed for TOA. Mobile networks currently do not employ these procedures; instead cells are synchronized using a common timing reference.

Token Ring

A computer network configuration in which all the computers are arranged on a ring. A token, which is a special bit pattern, travels around the ring. To send a message, the host must be in receipt of the token; this is attached to each message that is sent. Once the host has completed its transmission the token is then released, to the next host requiring service. This process continues and is used as the basis for contention resolution.

Toll office

A central office used primarily for supervising and switching toll traffic.

Toll quality

Toll quality is the term normally given to commercially available voice services.

Tor

Initially known as “The Onion Router”, Tor is an Internet based overlay network of Tor Relays which work together in order to provide web anonymity for Tor users. In essence, the Tor network will use several layers of encryption in order to obfuscate the origin of the web traffic, hence keeping the source IP address of the Tor user secret. Tor also supports “Tor Hidden Services”, which are websites only accessible from the Tor network. Tor hidden services use the Tor network to keep the origin of the website secret, hence making it difficult for law enforcement/government to shut illegal/censored websites down.

ToS - Type of Service

The IP (Internet Protocol) uses the ToS (Type of Service) field to provide an indication of the quality of service desired. These parameters are to be used to guide the selection of the actual service parameters when transmitting an IP datagram through a particular network. The type of service filed in some cases has been renamed the DSCP (DiffServ Code Point).

TPC - Transmit Power Control

The UE (User Equipment) and Node B generate TPC (Transmit Power Control) commands to control each others transmit power. This information is sent in the TPC field of the DPCCH (Dedicated Physical Control Channel). TPC commands are sent 1500 per second.

TPDU - Transfer Protocol Data Unit

The payload of the SMS Transfer Protocol.

TR-069

This DSL Forum Technical Report defines an application layer protocol which is used for remote configuration of terminal devices, such as DSL modems, HNBs and STBs. Essentially, the standard came about due to the growing complexity of CPE devices, effectively preventing typical users from correctly configuring them. As such, TR-069 provides an auto configuration mechanism between the CPE and a remote node in the service provider network termed the Auto Configuration Server.

Traffic

The information moved over a communication channel.

Traffic capacity

The maximum traffic per unit of time that a given telecommunications system, subsystem, or device can carry under specified conditions.

Traffic Channel

A logical channel used for the transport of user data.

Traffic Class

The traffic class in UMTS identifies the type of application for which the UMTS bearer service is optimized. Options include conversational, streaming, interactive, and background.

Transceiver

A device that is capable of both transmission and reception of a signal.

Transcoder

A Transcoder function is used to transform signals from one type to another. Usually from 64Kbps PCM (Pulse Code Modulation) to another compressed variant, and vice-versa.

Transcoding

The direct digital to digital conversion from one encoding scheme, such as voice PCM (Pulse Code Modulation), to a different encoding scheme without returning the signals to analogue form.

Transmission line

The material medium or structure that forms all or part of a path from one place to another for directing the transmission of energy, such as electric currents, magnetic fields, acoustic waves, or electromagnetic waves. Transmission lines include wires, optical fibres, coaxial cable and waveguides.

Transmission loss

The decrease in power that occurs during transmission from one point to another. Transmission loss is usually expressed in dB (Decibel) per metre.

Transmission medium

Transmission medium A substance, such as fibre-optic cable, twisted-pair cable, coaxial cable, waveguide, water, and air, that can be used for the propagation of signals.

Transmitted code power

Transmitted code power is the transmitted power on one channelization code on one given scrambling code on one given carrier.

Transparent

A process that allows a transmission system to accept user information and deliver the corresponding user information in an unchanged form.

Transport Block Set Size

The Transport Block Set Size is defined as the number of bits in a Transport Block Set.

Transport Channels

In UMTS the physical layer offers information transfer services to MAC (Medium Access Control) and higher layers. The physical layer transport services are described by how and with what characteristics data is transferred over the radio interface. An adequate term for this is Transport Channel.

Transport Format

Transport Format is defined as a combination of attributes which include: error protection, timing, interleaving, bit rate and mapping onto physical channels.

TRAU - Transcoder and Rate Adaptation Unit

This is an entity that performs a transcoding function for speech channels and RA (Rate Adaptation) for data channels.

Treselections

This specifies the cell reselection timer value in UMTS.

TrFO - Transcoder Free Operation

This term is applicable to calls that have no transcoders involved in the connection between the source codecs.

TrGW - Transition Gateway

The TrGW sits on the media path of any traffic entering or leaving the service provider’s IMS network. The primary role of the TrGW is to facilitate interworking between two different domains which may be using different addressing schemes, codecs etc. The TrGW is controlled by the IBCF (Interconnection Border Control Function).

Triband

A phone that is capable of operating on three frequency bands, e.g. 900MHz, 1800MHz and 1900MHz.

Tributary office

A local office, located outside the exchange in which a toll centre is located which has a different rate centre from its toll centre.

TrM - Transparent Mode

In UMTS information may be transmitted across the Iu interface in either TrM (Transparent Mode) or SMpSDU (Support Mode for predefined SDU size mode) using the Iu Protocol. The transparent mode is intended for those RAB (Radio Access Bearer) that do not require any particular service from the Iu protocol.

Trojan Horse

This is a program that performs some undesired yet intended action while or in addition to, pretending to do something else. One common class of trojans are fake login programs for example, collecting accounts and passwords by prompting for this info just like a normal login program does. Another is a Disk Defragger that erases files rather than reorganizing them. A Trojan Horse does not attempt to reproduce itself.

Troposphere

The lower layers of the atmosphere, in which the change of temperature with height is relatively large. The thickness of the troposphere varies with season and latitude. It is usually 15km to 18km thick over tropical regions, and less than 9km thick over the poles.

Tropospheric scatter

Usually called Troposcatter, tropospheric scatter identifies the propagation of radio waves by scattering as a result of irregularities or discontinuities in the physical properties of the troposphere

TRS - Transceiver Subsystem

The term TRS (Transceiver Subsystem) is sometimes used to identify a group of TRX (Transceivers) that belong to the same cell.

Trunk

A transmission channel between two points that are switching centres or nodes. Trunks may be used to interconnect switches to form networks.

TS - Timeslot

In a TDMA (Time Division Multiple Access) system the carrier is split into multiple timeslots, the duration being dependant on the technology. Each user is assigned one or more timeslots for communication purposes.

TS - Traffic Stream

The term TS is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancement. It defines a particular established Quality of Service flow in both the uplink and downlink.

TSC - Training Sequence Code

Used mainly in TDMA (Time Division Multiple Access) systems the training sequence is used to maintain timing and equalize the channel. This helps reduce the impact of ISI (Inter Symbol Interference) and multipath effects.

TSID - Traffic Stream Identifier

This is a term used in IEEE (Institute of Electrical and Electronics Engineers) 802.11 networks which are supporting the QoS (Quality of Service) enhancements defined in the 802.11e standard. The term is used to identify one of eight uplink and downlink traffic streams.

TSL - Transaction SubLayer

TCAP (Transaction Capabilities Application Part) comprises two protocol sublayers called the TSL (Transaction Sublayer) and the CSL (Component Sublayer). The transaction sublayer is the lower TCAP sublayer and defines two types of dialogues namely unstructured and structured.

TSN - Time Sensitive Networking

TSN (Time Sensitive Networking) is an IEEE specification which can be deployed in industry to provide deterministic message transfer over an Ethernet data network. TSN relies on a centrally managed system which coordinates scheduling across all of the connected applications and processes within the system to ensure that messages are delivered with the appropriate latency and within the correct timeframe.

Tsp - Timer session period

The Tsp is a variable used during the CAMEL Apply Charging Process and is used to record the amount of session time that has transpired between the sending of the Apply Charging Report sent by the SSF and the subsequent Apply Charging message sent by the SCF.

TSPEC - Traffic Specification

The term TSPEC is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancements, amongst other QoS capable networks. It defines a series of parameters, characteristics and Quality of Service expectations of a traffic flow.

TT - TSN Translator

TSN Translators are used when a 5G network is functioning as a TSN (Time Sensitive Networking) Bridge. In particular, both the UE and UPF (User Plane Function) will contained TSN TT functionality which allows the 5G network components to interact with the remainder of the TSN deployment.

TTA - Telecommunications Technology Association

The Telecommunications Technology Association was founded as a voluntary standards body and has established a total of 450 standards in telecommunications fields. Its main aim is to enhance the Korean national infrastructure of telecommunication systems.

TTG - Tunnel Termination Gateway

The TTG is a logical element of the PDG, designed to terminate IPSec tunnels between itself and the mobile residing on Untrusted non-3GPP access (typically WiFi).

TTI - Transmission Time Interval

This is defined as the inter-arrival time of TBS (Transport Block Set), and is equal to the periodicity at which a Transport Block Set is transferred by the physical layer on the radio interface. It is always a multiple of the minimum interleaving period (e.g. 10ms, the length of one RF (Radio Frame)). The MAC (Medium Access Control) delivers one Transport Block Set to the physical layer every TTI.

TTL - Time To Live

Time To Live is a field in the IP header which indicates how long a packet should be allowed to survive before it is discarded. TTL essentially determines the maximum number of hops permitted.

Tunnelling

The generic telecommunication meaning of the term tunnelling is to carry a PDU (Protocol Data Unit) inside a protocol of the same type. An example is IP (Internet Protocol) tunnelling, in which IP is carried inside IP. It is also used to describe the creation of an encrypted/secured link over a public network.

TUP - Telephone User Part

Telephone User Part was an earlier implementation of SS7 that did not allow for data type applications hence the introduction of ISUP (ISDN User Part).

Turbo Code

A powerful type of error correcting code that utilizes the outputs of two convolutional coders.

TURN - Traversal of UDP through Relay Network Address

TURN is used as a NAT (Network Address Translation) mechanism which is similar in purpose to STUN (Simple Traversal of UDP through NAT). However, TURN works when symmetrical NAT is in operation, whereas STUN fails to operate in this situation.

TWAG - Trusted Wireless Access Gateway

TWAGs enable mobiles to connect to a PDN-GW via a trusted WiFi network. With Trusted Non-3GPP network access, the security of the WiFi network is assured and as such the TWAG allows this to occur when no direct connectivity is in place between the Trusted WiFi router and the PDN-GW.

TWAMP - Two Wire Active Measurement Protocol

TWAMP is an open protocol defined in RFC 5357 which is used to measure the network performance between two devices that support the TWAMP protocol. It utilizes two protocols, TWAMP-Control and TWAMP-Test. In addition, there are two variants, TWAMP and TWAMP Light. The TWAMP control and reflector entities involved exchange packets as part of a session. Reflected packets are timestamped, enabling performance of the network to be measured.

TWAN - Trusted WLAN Access Network

A type of non 3GPP access network which has a trust relationship with the 3GPP core network.

TWAP - Trusted WLAN AAA Proxy

For mobiles accessing the network via Trusted Non 3GPP access eg trusted WiFi, the TWAP is required in order to support authentication information acquisition from the HSS.

TX - Transmitter

The source or generator of any signal on a transmission medium.

TXOP - Transmission Opportunity

The term TXOP is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancement. Used in both EDCA and HCCA modes of operation, the TXOP is a bounded time interval in which Stations supporting Quality of Service are permitted to transfer a series of frames. A TXOP is defined by a start time and a maximum duration.

Type field

The type field forms part of the IPv4 (IP version 4) header, and is used to indicate the transport PDU (Protocol Data Unit) that forms the payload of the datagram. This information is used to pass the PDU through the correct SAP (Service Access Point) to the higher layer transport protocol. The values of the type field that indicate the higher layer protocol were listed until 1994 in RFC (Request for Comments) 1700, this has now been superseded by an online database supported by the IANA. Typical examples include 6 for TCP (Transmission Control Protocol) and 17 for UDP (User Datagram Protocol).

U - U (Unnumbered Information)

LLC (Logical Link Control) U (Unnumbered Information) frames can be sent in both ADM (Asynchronous Disconnected Mode) and ABM (Asynchronous Balanced Mode). There is no acknowledgement of receipt of U frames.

U - U interface

A user to network interface reference point that is characterized by the use of a 2 wire loop transmission system that conveys information between the 4 wire user to network interface.

U-CSIU-CSI - USSD – CAMEL Subscription Information

The U-CSI contains trigger information which is used to invoke a USSD application in the CSE for CAMEL served subscribers.

U-RNTI - UTRAN Radio Network Temporary Identifier

The UE (User Equipment) having an RRC (Radio Resource Control) connection will be allocated a S-RNTI (Serving Radio Network Temporary Identifier). The SRNC (Serving Radio Network Controller) identifier together with S-RNTI is a unique identifier of the RRC connection within a network. The combination of SRNC identifier and S-RNTI is referred to as U-RNTI (UTRAN Radio Network Temporary Identifier), which is used on the radio interface.

U/L - Uplink

The portion of a communications link used for the transmission of signals from a mobile to a base station or satellite. An uplink is the converse of a downlink. In some systems uplink is commonly referred to as the Reverse direction and Downlink being the Forward direction.

UA - Unnumbered Acknowledgement

Unnumbered Acknowledgement encoding is used as a response only. It is used to positively acknowledge a SABM (Set Asynchronous Balance Mode) or a disconnect command.

UA Channel - User Asynchronous data Channel

In Bluetooth the UA (User Asynchronous data) Channel is used to carry L2CAP (Logical Link Control and Adaptation Protocol) transparent asynchronous user data. It is usually carried on the ACL (Asynchronous Connectionless link).

UAC - User Agent Client

This is a SIP (Session Initiation Protocol) term for a function that performs client functionality. That is it generates a request which in turn is serviced by the UAS (User Agent Server).

UAN - Universal Access Number

This service allows a subscriber to publish a national number and have the incoming calls routed to different destinations based on various criteria such as the geographical location of the caller, the time of day and the date on which the call is made.

UAPSD - Unscheduled Automatic Power Save Delivery

The term U-APSD is used in wireless networks supporting the IEEE 802.11e Quality of Service enhancement. It was introduced in order to support power management in QBSS. In essence, it involves a QAP delivering downlink frames which belong to a specified access class to power saving Stations automatically. The Unscheduled variant is triggered by a Station receiving either a Delivery or Trigger enabled frame from a particular access class.

UARFCN - UMTS Absolute Radio Frequency Channel Number

The carrier frequency is designated by the UTRA Absolute Radio Frequency Channel Number. The value of the UARFCN in the IMT2000 (International Mobile Telephony 2000) band is defined as follows: Uplink UARFCN (Nu) = 5 x Frequency (MHz) and Downlink UARFCN (Nd) = 5 x Frequency (MHz).

UAS - User Agent Server

This is a SIP (Session Initiation Protocol) term for a function that performs server functionality. That is it responds to a request made by a SIP UAC (User Agent Client).

UDC - Unified Data Convergence

UDC is a 3GPP initiative which seeks to rationalize the databases found across the key mobile technologies such as 2G, 3G, 4G, 5G and IMS. The general premise is that across these technologies, common subscriber data is routinely stored and accessed. As such, this data can be stored in a common backend database termed the UDR (Unified Data Repository). Entities seeking to obtain specific information from this common database can use AFEs (Application Front Ends) specific to their network. For example, a 4G MME wishing to access a specific piece of subscriber data will utilize the 4G HSS AFE.

UDI - Unrestricted Digital Information

This is an ISDN (Integrated Services Digital Network) term to describe the ability to transfer any bit pattern over a digital channel.

UDM - Unified Data Management

The Unified Data Management is related to the 3GPP 5G Architecture. This supports the ARPF (Authentication Credential Repository and Processing Function) and stores the long-term security credentials used in authentication for AKA. In addition, it stores subscription information.

UDP - User Datagram Protocol

UDP is a lightweight Transport Layer protocol, providing source and destination port addressing for the multiplexing/demultiplexing of higher layer applications onto the same transport bearer. Other than port addressing, the UDP header contains a Length and a Checksum field, resulting in a low transmission overhead, albeit at the cost of reliable delivery (UDP does not provide a retransmission facility).

UDR - Unified Data Repository

The UDR is a converged repository of subscriber information and can be used to service a number of network functions. For example, the 5G UDM (Unified Data Management) can use the UDR to store and retrieve subscription data. Alternatively, the PCF (Policy Control Function) can use the UDR to store and retrieve policy related data. From a CIoT perspective, the NEF (Network Exposure Function) may use the UDR to store subscriber related data that is permitted to be exposed to 3rd party applications.

UDSF - Unstructured Data Storage Function

In 5G, the UDSF supports data storage for stateless network functions. That is, rather than a given network function holding its own storage resources, it will instead store UE context data in the UDSF.

UDT - UNITDATA

The basic message of connectionless SCCP (Signalling Connection Control Part) is the UDT (UNITDATA) message. When SCCP detects that a destination for a message is prohibited the UDT can either be discarded or returned to the originator as a UDTS (UNITDATA SERVICE).

UDTS - UNITDATA Service

This SCCP (Signalling Connection Control Part) connectionless message is utilized when a UDT (UNITDATA) message is undeliverable and the message originator has requested a delivery report.

UE - User Equipment

The UMTS Subscriber or UE (User Equipment) is a combination of ME (Mobile Equipment) and SIM / USIM (Subscriber Identity Module / UMTS Subscriber Identity Module).

UE-AMBR - UE – Aggregate Maximum Bit Rate

In LTE, UE-AMBR is a bandwidth limitation applicable to the total accumulated bandwidth for all of the non GBR bearers a mobile has in place (across all PDN connections).

UE-PC5-AMBR - UE-PCF Aggregate Maximum Bitrate

In LTE V2X, UE PC5 links are limited using UE-PC5-AMBR. This limits the aggregated bit rate that can be expected with a peer device. The UE-PC5-AMBR is obtained by the MME from the HSS and is part of the subscription data. It is provided to the eNB for use in resource management of the UE’s PC5 transmission for V2X services in network scheduled mode.

UG-CSI - USSD General – CAMEL Subscription Information

The UG-CSI is held in the HLR and is not sent to any other node. It contains trigger information which is used to invoke a USSD application in the CSE for all subscribers in the HLR. It is possible that for a particular service code both U-CSI and UG-CSI are applicable.

UHF - Ultra High Frequency

Frequencies from 300MHz to 3000MHz.

UI - Unconfirmed Information

In LLC (Logical Link Control) unacknowledged operation, Layer 3 information is transmitted in numbered UI (Unconfirmed Information) frames. The UI frames are not acknowledged at the LLC layer.

UI - Unnumbered Information

Unnumbered Information frames can be sent in both ADM (Asynchronous Disconnected Mode) and ABM (Asynchronous Balanced Mode). There is no acknowledgement of receipt of UI frames.

UI Channel - User Isochronous data Channel

In Bluetooth the UI (User Isochronous data) Channel is used to carry L2CAP (Logical Link Control and Adaptation Protocol ) transparent isochronous user data. It is usually carried on the ACL (Asynchronous Connectionless link).

UIM - User Identity Module

The User Identity Module may contain information such as the NAM (Number Assignment Module) and subscription feature information. It is possible for the UIM to be integrated into the ME (Mobile Equipment) or it may be a R-UIM (Removable Identity Module).

UL-TFT - Uplink Traffic Flow Template

An Uplink Traffic Flow Template is the set of uplink packet filters set out in a TFT. A DL TFT is the set of downlink packet filters defined in a TFT. Every dedicated EPS bearer is associated with a TFT. The UE uses the UL TFT for mapping traffic to an EPS bearer in the uplink direction and the PDN GW maps traffic to the EPS bearer in the downlink.

ULF - Ultra Low Frequency

Frequencies from 300Hz to 3000Hz.

ULI - User Location Information

User Location Information is a group of identities relating to the location of a mobile device within the network coverage area. The ULI can comprise of an LAI, ECGI, TAI, RAI, SAI and a CGI.

Um - Air Interface (GSM)

Interface between MS (Mobile Station) and BSS (Base Station System). The Um interface is the GSM / GPRS network interface for providing circuit and packet data services over the radio interface to the MS.

UMA - Unlicensed Mobile Access

Unlicensed Mobile Access is an industry collaboration to extend GSM and GPRS services into customer sites by utilizing unlicensed radio technologies such as WiFi (Wireless Fidelity) and Bluetooth. This is achieved by tunnelling GSM and GPRS protocols through a broadband IP network towards the Access Point situated in the customer site and across the unlicensed radio link to the mobile device. Although the title UMA is often still used, the technology is now termed GAN and has seen relatively limited deployment.

UMAN - Unlicensed Mobile Access Network

An Unlicensed Mobile Access Network is derived by utilizing existing unlicensed radio technologies such as WiFi (Wireless Fidelity) and Bluetooth to extend GSM and GPRS services into customer sites. This is achieved by introducing a UNC (Unlicensed Network Controller) into the network which connects the existing GSM and GPRS core network, through a broadband IP network, to the Access Point situated in the customer site. As such, customers can switch between the traditional GSM / GPRS network and the UMAN as the move into and out of coverage. Although the title UMA is often still used, the technology is now termed GAN.

UMD - Unacknowledged Mode Data

In UMTS the UMD PDU (Protocol Data Unit) is used to convey sequentially numbered PDU containing RLC (Radio Link Control) SDU (Service Data Unit) data. It is used by RLC when using unacknowledged data transfer.

UMTS - Universal Mobile Telecommunications System

A 3G mobile communication system which supports improved data rates over GSM and subsequently provides an enhanced range of multimedia services. UMTS has increased convergence between telecommunications, IT (Information technology), media and content industries to deliver new services and create fresh revenue generating opportunities. UMTS delivers low cost, high capacity mobile communications, offering data rates as high as 2Mbps (under ideal conditions) with global roaming and other advanced capabilities. The specifications defining UMTS are formulated by the 3GPP.

Unbalanced line

A transmission line in which the voltage levels on the two conductors are not equal with respect to ground.

UNC - Unlicensed Network Controller

A Unlicensed Network Controller is found with a UMAN (Unlicensed Mobile Access Network). Its function is to connect the existing GSM and GPRS core network, through a broadband IP network, to the Access Point situated in the customer site. As such, it acts in a very similar way to a BSC (Base Station Controller) and PCU (Packet Control Unit) found within GSM and GPRS networks. However, the UNC supports a number of additional UMA (Unlicensed Mobile Access) specific protocols termed URLC (UMA Radio Link Control) and URR ( UMA Radio Resource). Although the title UMA is often still used, the technology is now termed GAN.

UNI - User to Network Interface

The interface between user equipment and private or public network equipment (e.g. ATM switches).

Unicode

The Unicode Worldwide Character Standard is a character coding system designed to support the interchange, processing and display of the written texts of the diverse languages of the modern world. In addition, it supports classical and historical texts of many written languages.

Unidirectional channel

A one way only channel.

Unique Challenge Response Procedure

A procedure by which the MS (Mobile Station) and the BS (Base Station) exchange information to confirm the mobile’s identity. The procedure is initiated by the BS (Base Station), which sends a challenge in the form of RANDU (Unique Random Variable).

UNIX

A portable, multiuser, time-shared operating system that supports process scheduling, job control, and a programmable user interface.

Unnumbered command

This may be used in a data transmission and represents a command that does not contain sequence numbers in the control field.

UPCON - User Plane CONgestion Management

As mobile networks become increasingly congested, the 3GPP have introduced techniques for RAN congestion management which are designed to reduce the impact of user plane congestion on the user’s service experience. UPCON introduces congestion mitigation techniques such as traffic prioritization, traffic reduction and limitation of traffic. UPCON utilizes additional network elements such as the RCAF (RAN Congestion Awareness Function) to support this.

UPF - User Plane Function

The User Plane Function is related to the 3GPP 5G Architecture. It is similar to the roles played by the Serving/Packet Gateway in a 4G LTE system. The UPF supports features and capabilities to facilitate user plane operation. Examples include: packet routing and forwarding, interconnection to the Data Network, policy enforcement and data buffering.

Uplink DPCH - Uplink Dedicated Physical Channel

There are two types of Uplink Dedicated Physical Channel, the uplink DPDCH (Dedicated Physical Data Channel) and the uplink DPCCH (Dedicated Physical Control Channel).

Uplink DPCH - Uplink Dedicated Physical Channel

There are two types of Uplink Dedicated Physical Channel, the uplink DPDCH (Dedicated Physical Data Channel) and the uplink DPCCH (Dedicated Physical Control Channel).

UPnP - Universal Plug and Play

UPnP is a generic term for a series of protocols and standards which support network devices such as computers, smartphones, printers etc. to seamlessly discover each other and establish a communication link in order to share data.

Upstream

The direction opposite to the data flow.

UPT - Universal Personal Telecommunications

A telecommunications service that provides personal mobility and service profile management. Users are identified by means of a UPT number.

URA - UTRAN Registration Area

The UTRAN (UMTS Terrestrial Radio Access Network) Registration Area is an area covered by a number of cells. The URA is configured in the UTRAN and broadcasted in relevant cells.

URI - Uniform Resource Identifier

A URI is an address string which identifies the location of a particular resource eg www.mpirical.com/tutorials.

URL - Uniform Resource Locator

A standard way of specifying the location of an object, typically a web page, on the Internet. URL are the form of address used on the WWW (World Wide Web). They are used in HTML (Hypertext Markup Language) documents to specify the target of a hyperlink which is often another HTML document (possibly stored on another computer). An example of a URL is http:\www.mpirical.com

URLC - UMA Radio Link Control

UMA (Universal Mobile Access) Radio Link Control is a protocol found within a UNC (Unlicensed Network Controller) to support the transfer of both GPRS control and user plane information between the UNC and the mobile device. This interface termed Up spans a broadband IP network in addition to the unlicensed radio technology in operation – WiFi (Wireless Fidelity) or Bluetooth.,

URLLC - Ultra Reliable Low Latency Communication

URLLC is one of the three facets of 5G, alongside MMTC (Massive Machine Type Communication) and eMBB (enhanced Mobile Broadband). In particular, URLLC features two parts; ultra-reliability which constitutes network reliability of beyond 99.999%, coupled with very low latency for packet transmission (in the order of 1ms and below). Note that the two are mutually exclusive in that some services will require both ultra-reliability and low latency, whereas other services may require one or the other.

URR - UMA Radio Resource

UMA (Universal Mobile Access) Radio Resource is a protocol found within a UNC (Unlicensed Network Controller) to support the transfer of GSM control plane information between the UNC and the mobile device. This interface termed Up spans a broadband IP network in addition to the unlicensed radio technology in operation – WiFi or Bluetooth.

URSP - UE Route Selection Policy

In 5G, the device can be provisioned with URSP information which provides information on which PDU Session on network slice a given service or application should use when it is activated.

US Channel - User Synchronous data Channel

In Bluetooth the US (User Synchronous data) Channel is used to carry transparent synchronous user data. It is carried in the SCO (Synchronous Connection Oriented) link only.

US-TDMA

A term sometimes used within Europe to identify the IS-136 (Interim Standard) TDMA (Time Division Multiple Access) based system.

USAT - Ultra Small Aperture Terminal

Satellite dishes for telemetry and other remote monitoring.

USB - Universal Serial Bus

The Universal Serial Bus provides an expandable, Plug and Play serial interface that ensures a standard, low-cost connection for peripheral devices such as keyboards, mice, joysticks, printers, scanners, storage devices, modems, and video conferencing cameras. Migration to USB is recommended for all peripheral devices that use legacy ports such as the PS/2, serial, and parallel ports.

USCH - Uplink Shared Channel

The Uplink Shared Channel is an uplink transport channel used in TDD (Time Division Duplex) mode, shared by several UE (User Equipment) carrying dedicated control or traffic data.

User

A person using or requesting telecommunications services.

User information

Information transferred across the functional interface between a source user and a telecommunications system for delivery to a destination user. Note: In telecommunications systems, user information includes user overhead information.

User Zone

Not to be confused with the Registration Zone, a User zone identifies an area within which CDMA Tiered Services may be provided. This usually corresponds to an RF (Radio Frequency) coverage area.

User Zone Registration

Whilst in the Idle State the mobile will register when it selects an active User Zone.

USF - Uplink State Flag

The Uplink State Flag is used on PDCH (Packet Data Channel) to allow multiplexing of radio blocks from a number of GPRS mobiles. USF is used in dynamic and extended dynamic medium access modes. The USF comprises 3bits at the beginning of each Radio Block that is sent on the downlink. It enables the coding of eight different USF states which are used to multiplex the uplink traffic.

USIM - UMTS Subscriber Identity Module

Usually referred to as a SIM card, the USIM ( UMTS Subscriber Identity Module) is the user subscription to the UMTS mobile network. The USIM contains relevant information that enables access onto the subscribed operator’s network.

USSD - Unstructured Supplementary Service Data

The USSD (Unstructured Supplementary Service Data) mechanism allows the MS (Mobile Station) user and a PLMN (Public Land Mobile Network) operator defined application to communicate in a way which is transparent to the MS and to intermediate network entities. An example of a USSD string is *#136#numbers#

USTS - Uplink Synchronous Transmission Scheme

To maximize the usage of 3G uplink capacity the 3GPP (Third Generation Partnership Project) is exploring techniques in which channel redundancy can be exploited. One approach is to implement USTS in which signals from mobiles within the cell are orthogonalized. That is, a number of mobiles are allocated the same scrambling code, but different channelization codes.

UT - Universal Time

The basis for coordinated distribution of time signals, counted from 0000 at midnight. When an accuracy better than one second is not required, Universal Time can be used to mean UTC (Coordinated Universal Time).

UTP - Unshielded Twisted Pair

A pair of unshielded wires that are twisted at routine intervals in order the minimize the amount of cross talk experienced from other pairs in the same cable.

UTRA - Universal Terrestrial Radio Access

Identifies the FDD (Frequency Division Duplex) and TDD (Time Division Duplex) mode of access for the UMTS System.

UTRAN - Universal Terrestrial Radio Access Network

UTRAN is a conceptual term identifying that part of a UMTS network which consists of one or more RNC (Radio Network Controller) and one or more Node B between Iu and Uu interfaces.

Uu - UMTS Air Interface

This is the radio interface between the UTRAN (UMTS Terrestrial Radio Access Network) and the UE (User Equipment) utilizing CDMA.

UUS - User-to-User Signalling

The UUS supplementary service allows the served subscriber to send/receive a limited amount of subscriber generated information to/from another user in association with a call to the user. This information shall be passed transparently (i.e. without modification of contents) through the network. Normally the network shall not interpret or act upon this information.

UV - Ultraviolet

Part of the electromagnetic spectrum in which the longest wavelength is just below the visible spectrum, extending from approximately 4nm to approximately 400nm.

UWC-136

A 3G (Third Generation) wireless standard based on TDMA (Time Division Multiple Access) technology. It was developed by the UWCC (Universal Wireless Communications Consortium).

UWCC - Universal Wireless Communications Consortium

An industry group supporting IS-136 (Interim Standard 136) TDMA (Time Division Multiple Access) and IS-41 (Interim Standard 41) wireless intelligent network technology.

V reference point

The interface point in an ISDN environment between the line termination and the exchange termination.

V-PCRF - Visited – Policy and Charging Rules Function

The PCRF is a policy decision point for subscriber data flows in the network. Using inputs from other network nodes, the PCRF will formulate rules which control how traffic flows (required QoS, restrictions, throttling, blocking, billing, etc) over the network down to individual subscriber SDF (Service Data Flow) granularity. The PCRF passes these rules to the PCEF (Policy and Charging Enforcement Function). In a roaming scenario, a Home PCRF can pass policy decision information to V-PCRF in the visited network.

V2I - Vehicle-to-Infrastructure

In relation to V2X, V2I (Vehicle-to-Infrastructure) enables vehicles to communicate with nearby roadside infrastructure, called RSU (Road side Units). This provides connectivity to fleet and traffic management centres, parking and toll control systems. It has a wide range of potential uses, such as connecting to smart parking systems to find available parking spaces automatically.

V2N - Vehicle-to-Network

In relation to V2X, V2N (Vehicle-to-Network) enables both broadcast and unicast communications to take place between vehicles and the V2X management system and also the V2X AS (Application Server). This is achieved by making use of the LTE network infrastructure and the E-UTRA. Vehicles are able receive broadcasted alerts regarding accidents further down the road or warnings of congestion or queues on the planned route.

V2P - Vehicle-to-Pedestrian

In relation to V2X, V2P (Vehicle-to-Pedestrian) involves direct communications between a vehicle and a pedestrian or multiple pedestrians within close proximity. In addition, communication can be to other vulnerable road users, such as cyclists. V2P is conducted directly or through the use of network infrastructure. It will facilitate warnings to be provided to the pedestrian of an approaching vehicle, and warnings to the vehicle of vulnerable road users.

V2V - Vehicle-to-Vehicle

In relation to V2X, V2V (Vehicle-to-Vehicle) involves direct communications between two vehicles, or multiple vehicles within close proximity. These vehicles could include passenger vehicles, commercial vehicles and emergency vehicles.

V2X AS - V2X Application Server

The V2X AS is a key component in the delivery of V2X services. It is involved in the handling of services, such as receiving uplink data and also delivering data to the vehicle or V2X device. It will also provision both the 5G core and the vehicle / V2X device with parameters in order to perform V2X communication over the PC5 and Uu reference points.

V2X CF - V2X Control Function

The V2X Control Function is the key management element for V2X related services in a network. It is used to assist with network relation actions, such as providing the UE with the parameters necessary to use V2X communications. In addition, it will liaise with the V2X AS to obtain information required for broadcast functionality.

VAD - Voice Activity Detector

The function of the VAD is to indicate whether each frame contains signals that should be transmitted, i.e. speech, music or information tones.

VAN - Value Added Network

A network using the communication services of other commercial carriers, using hardware and software that permit enhanced telecommunication services to be offered.

VANC - VoLGA Access Network Controller

The VANC performed an aggregation and service control function within a VoLGA network. It should be noted that VoLGA has not seen significant deployment, with service providers adopting VoLTE as the preferred delivery mechanism for LTE based voice services.

VAS - Value Added Service

Value Added Services are unlike basic services in that they have unique characteristics and they relate to other services in a completely different way. They also provide benefits that basic services can not.

VBR - Variable Bit Rate

Variable Bit Rate is one of the traffic classes used by ATM (Asynchronous Transfer Mode). Unlike a permanent CBR (Constant Bit Rate) channel, a VBR data stream varies in bandwidth and is better suited to non real time transfers than to real-time streams such as voice calls.

VC - Virtual Channel

The communication channel associated with a VCC (Virtual Channel Connection) that provides for the transport of ATM (Asynchronous Transfer Mode) cells.

VCC - Virtual Channel Connection

A concatenation of VCL (Virtual Channel Link) between the points where the ATM (Asynchronous Transfer Mode) service users access the ATM Layer.

VCI - Virtual Channel Identifier

The identifier in the ATM (Asynchronous Transfer Mode) cell header that identifies to which virtual channel the cell belongs.

VCL - Virtual Channel Link

A Virtual Channel Link is a means of unidirectional transport of ATM (Asynchronous Transfer Mode) cells. It exists between the points where a VCI (Virtual Channel Identifier) value is assigned and the point where the value is translated or removed.

VDSL - Very high data rate Digital Subscriber Line

One of the family of DSL (Digital Subscriber Line) services. It offers very high data rates over relatively short distances (up to 55Mbps over a line length of 300m).

VDSL - Very High Digital Subscriber Line

A variant of HDSL (High Digital Subscriber Line) which provides a service at data rates greater than 10Mbps. With this increased data rate, there is a significant decrease in the radius which such a system can operate. For this reason a VHDSL system would be implemented with fibre optics transporting the data to a remote sight near the subscribers, and use VHDSL to bridge the last 30 metres or so to the subscriber.

VDSL2 - Very High Speed Digital Subscriber Line

VDSL2 (Very High Speed Digital Subscriber Line) is a DSL technology which can provide symmetrical links of up to 100Mbps, although this figure is largely dependent on the length of copper twisted pair available. VDSL2 uses similar modulation techniques to ADSL , with the increased bandwidth a direct result of the close proximity to a fibre optic node.

Verisign

Verisign is a leading provider of public key infrastructure and digital certificate solutions. These are used by enterprises, web sites and consumers to conduct secure communications and transactions over the Internet and private networks.

VF - Voice Frequency

Pertaining to those frequencies within that part of the audio range that is used for the transmission of speech. In telephony, the usable voice-frequency band ranges from approximately 300Hz to 3400Hz (3.1KHz bandwidth).

VGCS - Voice Group Call Service

Allows speech conversation of a predefined group of service subscribers in half duplex mode on the radio link.

VHF - Very High Frequency

Frequencies from 30MHz to 300MHz.

VID - VLAN Identifier

The VID is contained within each Ethernet frame of an Ethernet VLAN , allowing switches to separate traffic based on VID, hence creating separate VLAN.

Videophone

A telephone that is coupled to an imaging device that enables the call receiver or the call originator, or both, to view one another as on television, if they so desire.

ViLTE - Video over LTE

An initiative standardized in GSMA IR.94 which sees conversational video services being made available to customers on LTE access networks.

VIM - Virtualized Infrastructure Manager

The VIM operates within the NFV MANO (Management and Orchestration) architecture, handling all activities associated with the NFVI, including resource management and operations management. In addition, the VIM will store the software images associated with the VNFs (Virtualized Network Functions) within the system.

VLAN - Virtual Local Area Network

VLAN is a term used to refer to an Ethernet network that shares the same physical infrastructure as other VLAN but is a logically separate entity. VLAN traffic is separated by marking each frame with a VID (VLAN ID), as specified by the IEEE 802.1Q working group. Alternatively, VLANs can be separated from one another based on their switch port.

VLD - Virtual Link Descriptor

The VLD provides a description of a Virtual Link within an NFV (Network Functions Virtualization) system. Key elements of the descriptor include the number of endpoints (for example an E-Line would contain 2 endpoints), link throughput and available QoS.

VLF - Very Low Frequency

Frequencies from 3KHz to 30KHz.

VLR - Visitor Location Register

The Visitor Location Register contains all subscriber data required for call handling and mobility management for mobile subscribers currently located in the area controlled by the VLR.

VMSC - Visited Mobile Switching Centre

The Visited Mobile Switching Centre is the term given to the MSC (Mobile Switching Centre) that is serving a mobile in the VPLMN (Visited Public Land Mobile Network).

VNF - Virtualized Network Function

Within an NFV (Network Functions Virtualization) framework, the VNF is the term given to a network node that has been implemented as a software process. An example could be an MME (Mobility Management Entity), where traditionally this would be a physical device but after virtualization, it would run as a software based VNF. All VNFs in the system will share compute, storage and networking resources through interaction with the NFVI (NFV Infrastructure).

VNFFDG - VNF Forwarding Graph Descriptor

Within the NSD (Network Service Descriptor), the VNFFGD defines the VNF Forwarding Graph, outlining the Virtual Links and VNFs (Virtualized Network Functions) which together form the Network Service.

VNFFG - VNF Forwarding Graph

The VNFFG defines the chain of VNFs (Virtualized Network Functions) which are linked together in order to instantiate a Network Service.

VNFM - VNF Manager

The VNF Manager operates within the NFV MANO (Management and Orchestration) architecture, handling all lifecycle management operations associated with the on-boarded VNFs (Virtualized Network Functions). This includes VNF instantiation, upgrade, scale up/down and termination.

VoB - Voice over Broadband

The term VoB (Voice over Broadband) refers to VoIP (Voice over IP) services that allow end users to make and receive calls over a broadband connection, for example using a DSL (Digital Subscriber Line) or cable connection. Services include: phone-to-phone, PC-to-phone and PC-to-PC calls.

Vocoder

A voice coder device that usually consists of a speech analyzer, which converts analogue speech waveforms into narrowband digital signals, and a speech synthesizer, which converts the digital signals into artificial speech sounds.

VoDSL - Voice over DSL

The term VoDSL (Voice over DSL) typically means the leveraging of the copper infrastructure to provide both quality voice services as well as support a wide variety of data applications over the same existing line to the customer’s site. VoDSL commonly implies a number of traffic circuits over a single DSL (Digital Subscriber Line) connection.

Voice memo

A voice recorder built into a phone enabling the user to record notes.

Voice Privacy

The voice transmitted over a CDMA Traffic Channel has some protection against eavesdropping over the air interface.

Voicemail

A service offered by networks that will record voice messages for users if they are unable to answer a call. Charges may apply for retrieving messages.

VoIP - Voice over Internet Protocol

Voice over IP is a system enabling voice data to be delivered using the IP (Internet Protocol). It is sometimes referred to as IP telephony.

VoLGA - Voice over LTE Generic Access

VoLGA was an early proposal for voice service delivery over an LTE transport network. The technology did not see any significant deployment, with service providers opting for VoLTE as the preferred voice delivery service.

VoLTE - Voice over LTE

Based on GSMA IR.92, VoLTE allows subscribers on LTE access to conduct voice calls, without the requirement to fall back to 2G or 3G. Call control is based on an IMS, which will include a TAS for supplementary services. In addition, an SCC-AS will typically be deployed in order to support SR-VCC. During a VoLTE call, subscribers will have a Dedicated EPS bearer in place which provides a guaranteed level of QoS.

VoNR - Voice over New Radio

VoNR is the general term given to IMS based voice services which use 5G as the access network (as opposed to LTE and VoLTE).

VoWiFi - Voice over WiFi

VoWiFi allows subscribers to conduct voice calls whilst using a WiFi access network. Call control is based on IMS and in many cases, the VoWiFi is integrated with the service providers VoLTE service offering. Therefore, subscribers can switch between LTE and WiFi access during a call.

VP - Virtual Path

Virtual Path enables the bundling of multiple ATM (Asynchronous Transfer Mode) VC (Virtual Circuit).

VPC - Virtual Path Connection

The concatenation of multiple ATM (Asynchronous Transfer Mode) virtual path links.

VPI - Virtual Path Identifier

The field in the ATM (Asynchronous Transfer Mode) cell header that identifies to which VP (Virtual Path) the cell belongs.

VPLMN - Visited Public Land Mobile Network

A Visited Public Land Mobile Network is a PLMN upon which the mobile subscriber has roamed when leaving their HPLMN (Home Public Land Mobile Network).

VPLS - Virtual Private LAN Service

VPLS is an Ethernet based virtual multipoint to multipoint service, typically implemented over an IP/MPLS network. Connectivity between customer sites using the VPLS service is based on PWE3.

VPN - Virtual Private Network

This is a private network link, which is carried on a public network. VPNs can be implemented in number of ways, ranging from: Layer 1 VPN utilizing physical layer links such as E1 and SDH; Layer 2 VPN using data link connections based on ATM, FR, Ethernet etc; Layer 3 VPN, typically based on IP in IP tunnelling techniques such as those provided by IPSec. In addition, MPLS networks are also extensively deployed to support VPN connectivity. In this case, customer traffic is kept separate through the use of unique labels per customer.

VPWS - Virtual Private Wire Service

VPWS is a virtual point to point connection, typically implemented over an MPLS network using PWE3.

VRB - Virtual Resource Block

The E-UTRA uses the concept of VRB (Virtual Resource Block) when allocating resources. It defines two types: LVRB (Local Virtual Resource Block) – this is the same as the PRBs; DVRB (Distributed Virtual Resource Block) – this identifies a distribution of the resources required over a number of PRBs.

VSWR - Voltage Standing Wave Ratio

A standing wave may be formed when a wave is transmitted into one end of a transmission line and is reflected from the other end by an impedance mismatch. VSWR is the ratio of maximum to minimum voltage in a standing wave pattern.

VT-CSI - Visited Terminated – CAMEL Subscription Information

CAMEL Phase 3 allows the initiation of terminating CAMEL services at the VMSC (Visited Mobile Switching Centre). The VT-CSI if present is passed to the VMSC/VLR during the Update Location procedure.

VT-IM-CSI - Visited Terminated – IP Multimedia – CAMEL Subscription Information

CAMEL Phase 3 allows the initiation of terminating CAMEL services at the VMSC (Visited Mobile Switching Centre). The VT-CSI if present is passed to the VMSC/VLR during the Update Location procedure. VT-IM-CSI allows for this functionality to be extended to the IMS.

WAE - WAP Application Environment

Nominally viewed as the ‘ WAP Browser’, the WAP 2.0 Application Environment has evolved to embrace developing standards of the Internet browser mark-up language.

WAEPL - Weighted Acoustic Echo Path Loss

A term used to identify the measure of the echo performance under normal conversation. ANSI / EIA / TIA -579 defines the measurement of WAEPL.

WAG - WLAN Access Gateway

The WAG is the gateway between a 3GPP and WLAN network. The WAG provides filtering, policy and charging functionality for the traffic between the WLAN user equipment and the 3GPP network.

WAN - Wide Area Network

A network that provides data communications to a large number of independent users spread over a larger geographic area than that of a LAN (Local Area Network). It may consist of a number of LAN connected together.

WAP - Wireless Application Protocol

A standard designed to allow the content of the Internet to be viewed on the screen of a mobile device such as mobile phones, personal organisers and pagers. WAP also overcomes the processing limitation of such devices. The information and services available are stripped down to their basic text format.

WAP Gateway

A WAP (Wireless Application Protocol) Gateway accesses web content for a mobile. In theory it is capable of converting HTML (Hypertext Markup Language) pages to WML (Wireless Markup Language) pages, but much of the content accessed from WAP Gateways has already been specially authored in WML.

Warchalking

Warchalking is the practice of marking symbols on pavements (sidewalks) and walls to indicate the presence of nearby open wireless access. It was supposedly inspired by the practice of Hobos during the Great Depression to use chalk marks to indicate which homes were friendly. Warchalking is now rarely encountered, since many WiFi networks feature automated security.

Wardriving

Wardriving was the practice of driving around an area looking for wireless networks that are open. Once detected, the sites are recorded by marking chalk symbols on the nearby pavement (sidewalk) or wall – a process referred to as warchalking. Wireless networks are detected by using sniffing software such as NetStumbler.

Waveguide

Waveguide is a medium that confines and guides a propagating electromagnetic wave. It is usually rectangular, elliptical, or circular in cross section.

Wavelength

The distance travelled by a wave during one complete cycle.

WB-AMR - Wideband Adaptive Multi Rate

Wideband variable rate speech codecs such as the WB-AMR codec used in UMTS and VoLTE systems offers superior wideband speech quality at data rates comparable to current narrowband speech codecs. With a higher data rate available, HD voice services can be offered to the customer.

WCDMA - Wideband Code Division Multiple Access

An ITU (International Telecommunications Union) standard derived from CDMA (Code Division Multiple Access) technology. WCDMA has been identified for 3G (Third Generation) mobile wireless technology.

WDM - Wavelength Division Multiplexing

A technique by which two or more optical signals having different wavelengths are simultaneously transmitted in the same direction over one fibre.

WDP - Wireless Datagram Protocol

Wireless Datagram Protocol is a general datagram service, offering a consistent service to the upper layer protocols and communicating transparently over one of the available underlying bearer services. It forms part of the WAP (Wireless Application Protocol) suite.

Web server

A Web Server is the device used to store or host web pages for an Intranet, Extranet or Internet.

WECA - Wireless Ethernet Compatibility Alliance

The WECA was formed by 3Com, Aironet, Harris Semiconductor, Lucent Technologies, Nokia and Symbol Technologies in August 1999 (it should be noted that a number of these companies have since been taken over). It was renamed the WiFi Alliance in October 2002.

WEP - Wired Equivalent Privacy

The IEEE 802.11b WLAN (Wireless Local Area Network) standard incorporates a confidentiality and integrity provision called WEP. To protect the data, WEP uses the stream cipher RC4 from RSA Security Inc. There are two levels of WEP commonly available; one based on a 40bit encryption key and 24bit initialization vector (64bit encryption) and one based on a 104bit encryption key and 24bit initialization vector (128bit encryption). Prior to encryption, the data is run through an integrity check process to ensure that the recipient of the data can detect whether it has been tampered with during transmission. The RC4 algorithm then generates a key stream from either the 64bit or 128bit encryption key which is applied to the user data and integrity check. In August 2001, Scott Fluhrer, Itsik Mantin, Adi Shamir published a paper entitled Weakness in the Key Scheduling Algorithm of RC4; which outlined a theoretical method for breaking the WEP key. Providing enough traffic has been captured, modern day cracking software can crack WEP in seconds.

White noise

Noise having a frequency spectrum that is continuous and uniform over a specified frequency band.

Wi-Fi 4

This the term given by the Wi-Fi Alliance to networks operating to the IEEE 802.11n standard.

Wi-Fi 5

This the term given by the Wi-Fi Alliance to networks operating to the IEEE 802.11ac standard.

Wi-Fi 6

This the term given by the Wi-Fi Alliance to networks operating to the IEEE 802.11ax standard.

Wi-Fi Direct

This is an extension of the IEEE 802.11 standard supporting a direct communication link between to Wi-Fi devices without the need for an Access Point.

Wi-Fi Easy Connect

One of the Wi-Fi Alliance’s certification programs, Wi-Fi Easy Connect operates alongside WPA3 (Wi-Fi Protected Access 3) to enhance the user experience when adding devices to a Wi-Fi network; especially those with a limited graphical user interface. Instead of detecting a Wi-Fi network and entering security keys, users will scan QR codes using a smartphone.

Wi-Fi HaLow

Incorporating the IEEE 802.11ah amendment, Wi-Fi HaLow supports a certification program for Wi-Fi based IoT devices requiring extended coverage and improved power efficiency. Examples of devices in this space include those targeted at smart homes, healthcare as well as industrial and agriculture.

Wi-Fi Location

Part of the Wi-Fi Alliance’s certification program, Wi-Fi Location enables accurate location information regarding the Wi-Fi device to be calculated by measuring the roundtrip delay for a signal passing between the access point and the device. Such information can then be used for navigation, alongside new feature rich services for manufacturing, retail and healthcare.

Wi-Fi Passpoint

Launched by the Wi-Fi Alliance in 2012, Wi-Fi Passpoint is an industry wide solution to streamline how users access Wi-Fi hotspots and eliminate the need to authenticate each time. Therefore, for networks supporting Passpoint, users may seamlessly switch between Wi-Fi networks or even between Cellular and Wi-Fi.

WiCoP - WLAN Control Protocol

WiCoP was a control protocol which allowed for the control and provisioning of large scale WLANs. WiCoP has since been obsoleted by CAPWAP (Control and Provisioning of Wireless Access Points).

Wideband

The term Wideband is often used to distinguish it from Narrowband, however both terms are subjective. It usually identifies a signal that occupies a broad frequency spectrum (Broadband).

WiFi - Wireless Fidelity

WiFi is an interoperability standard developed by the WiFi Alliance and issued to those manufacturers whose IEEE 802.11 equipment has passed a suite of basic interoperability tests. Equipment passing these tests carries the WiFi logo.

WiFi Alliance

The WiFi Alliance is a non profit international association formed in 1999 to certify interoperability of wireless local area network products based on the IEEE 802.11 specifications. WiFi product certification began in March 2000. One of the goals of the WiFi Alliance is to ensure customers realize maximum benefit from their WiFi products in a secure and productive manner. Equipment passing these interoperability tests are allowed to carry the WiFi logo and service providers meeting a minimum service level may display the WiFi Zone logo.

WiFi Zone

The WiFi Zone is a certification award issued by the WiFi Alliance to service providers using WiFi certified equipment and meeting a minimum service level. The WiFi Alliance provide a register of service providers enabling users to find a location offering WiFi public access.

Wild Card APN

The APN (Access Point Name) field in the HLR (Home Location Register) may contain a wild card APN if the HPLMN (Home Public Land Mobile Network) operator allows the subscriber to access any network of a given PDP (Packet Data Protocol) Type. If an SGSN (serving GPRS Support Node) has received such a wild card APN, it may either choose the APN Network Identifier received from the Mobile Station or a default APN Network Identifier for addressing the GGSN (Gateway GPRS Support Node) when activating a PDP context.

WiMAX - World wide Interoperability for Microwave Access

WiMAX is a mobile broadband technology standardized by the IEEE 802.16m working group. Although WiMAX is a potential option for supporting 4G, it has seen mixed success around the globe, with many service providers adopting LTE as an alternative.

WISP - Wireless Internet Service Provider

A WISP is an Internet Service Provider who provides access to the public Internet via a wireless connection. This is achieved in most cases by using the WiFi technology.

WLAN - Wireless Local Area Network

A WLAN is a LAN which uses a wireless technology such as WiFi in order to allow devices to communicate with one another.

WLL - Wireless Local Loop

Sometimes called Radio in the Loop, Fixed Radio Access or Fixed Wireless Local Loop. WLL is a system that connects subscribers to the PSTN (Public Switched Telephone Network) using radio signals as a substitute for copper for all or part of the connection between the subscriber and the switch.

WML - Wireless Markup Language

The Wireless Mark up Language is the WAP (Wireless Application Protocol) equivalent to HTML (Hyper Text Mark up Language) used to construct web pages for a WAP device.

WMM - WiFi Multi Media

This termed is used in WiFi networks to define a network capable of supporting QoS (Quality of Service) traffic such as voice, video etc. These capabilities have been defined in the IEEE (Institute of Electrical and Electronics Engineers) 802.11e enhancement.

Worm

A worm is designed to create large volumes of network traffic through self replication and distribution to other network nodes. Significant worms such as MyDoom and Sobig were responsible for grinding the Internet to a halt. Nowadays, anti-malware software and hardware is designed to spot the traffic patterns associated with a worm and mitigate the attack accordingly.

WPA - WiFi Protected Access

Proposed jointly by the IEEE and WiFi Alliance , WiFi Protected Access is a specification of standards based, interoperable security enhancements that increase the level of data protection and access control for existing WiFi networks. WPA has been designed to be forward compatible with the IEEE 802.11i enhancement, which is also termed WPA2. It utilizes the enhanced data encryption TKIP (Temporal Key Integrity Protocol) in addition to user authentication using 802.1X and EAP (Extensible Authentication Protocol).

WPA2 - WiFi Protected Access 2

The successor to WPA, WPA2 features the mandatory elements of the 802.11i WiFi security standard. This includes support of an AES based encryption mechanism termed CCMP (Counter Mode CBC-MAC Protocol).

WPA3

Building upon the near universal adoption of WPA2 (Wi-Fi Protected Access 2), WPA3 was introduced in 2018 to bring new and more robust security capabilities to both personal and enterprise networks. The new standard from the Wi-Fi Alliance introduces a new approach to authentication termed SAE (Simultaneous Authentication of Equals), makes devices more resistant to offline dictionary attacks and provides greater protection from password guessing by third parties.

WRC - World Radio Conference

The WRC is promoted and organized by the ITU-R (International Telecommunications Union – Radiocommunications Standardization Sector) in order to discuss and possibly amend Radio Regulations (the rules which govern how RF spectrum is utilized). The WRC usually meet every two years to discuss radio related issues.

WSP - Wireless Session Protocol

Wireless Session Protocol provides the upper level application layer of WAP (Wireless Application Protocol) with a consistent interface for two session services. The first is a connection-mode service that operates above the transaction layer protocol, and the second is a connectionless service that operates above a secure or non secure datagram transport service.

WTLS - Wireless Transport Layer Security

The Wireless Transport Layer Security layer is designed to provide privacy, data integrity and authentication between two communicating applications. WTSL forms part of the WAP (Wireless Application Protocol) suite.

WTP - Wireless Transaction Protocol

Wireless Transaction Protocol has been defined as a light weight transaction oriented protocol that is suitable for implementation in thin clients and operates efficiently over wireless datagram networks. WTP forms part of the WAP (Wireless Application Protocol) suite.

WWW - World Wide Web

An international, virtual network based information service composed of Internet host computers that provide on line information.

X-Modem

A file transfer protocol, written in 1977 by Ward Christiansen. This protocol was effective but slow. Later versions (X-Modem2 and X-Modem1K) were also introduced.

X.25

The X.25 protocol is a widely available, low speed, packet switched data service. It offers data rates below those of Frame Relay and in today’s next generation networks, use of X.25 is very rare.

X.400

X.400 is the universal protocol for email. X.400 defines the envelope for email messages so all messages conform to a standard format.

X.500

The ITU X.500 family of standards defines X.500 directory services. The directory can be used for many applications, such as storing certificates, or other information. Protocols such as LDAP are often used to access the X.500 Directory.

X.509

X.509 is the ITU recommendation that defines the format for digital certificates and CRL (Certificate Revocation Lists). X.509 applications include X.509 version 3 for public-key certificates and X.509 version 2 for CRL.

X2AP - X2 Application Protocol

X2AP is a control protocol found between eNBs on the X2 control plane. Main functions of X2AP include X2 based mobility, as well as X2 “Global Procedures”. The former is largely associated with eNB (Evolved Node B) controlled handover procedures whereas the latter deals with the establishment and management of the X2 connection.

XDMS - XML Document Management Server

An XDMS is responsible for hosting several Application Usages (essentially an Application Usage is an instance of an XML configuration document relative to a particular aspect of a service eg Converged Address Book, Social Presence). Client devices such as mobile phones can use XCAP (XML Configuration Access Protocol) in order to interact with these Application Usages in order to acquire or manipulate the data within the XML document.

xDSL

Term used for all forms of technology using a DSL (Digital Subscriber Line). DSL enables simultaneous two way transmission of voice and high speed data over a phone line.

XML - eXtensible Markup Language

The major difference between HTML (Hypertext Markup Language) and XML is that HTML describes the content of a web page and XML classifies the information. XML indicates what type of information should go where and in what format.

XnAP - Xn Application Protocol

XnAP is the control protocol used between gNBs to support a variety of RAN related procedures, such as establishing Dual Connectivity, coordination of Xn based handovers, data forwarding and RAN Paging. During the handover process, the source gNB will provide the target gNB with all the necessary information it needs to handle the subscriber, including security and User Plane connectivity information. For Dual Connectivity, the Master gNB will use XnAP to set up a Secondary gNB, with each gNB serving the user simultaneously.

Xon/Xoff

Xon/Xoff is a protocol for controlling the flow of data between DCE (Data Circuit Terminating Equipment) and other devices ( DTE (Data Terminal Equipment)) on an asynchronous serial connection.

XRES - Expected Response

In the UMTS authentication process the network sends RAND (Random Number) to the UMTS Subscriber, XRES is the value that the network is looking for to indicate a positive response.

Y-Modem

A file transfer protocol based on X-Modem , Y-Modem was designed by Chuck Forsberg to add batch transmission, and variable block size. The variable function was seldom ever at the maximum size, 1024 bytes. The error detection scheme was CRC (Cyclic Redundancy Check). A subsequent version was Y-Modem-G. This was an effort to send data in a stream, evaluating the blocks on the fly and only talking back to the sender if there was an error. Both programs had to be identical and the noise predominant on POTS (Plain Old Telephone Service) at the time was a problem.

Yagi

A Yagi antenna, also known technically as a Yagi-Uda unidirectional array, is a unidirectional antenna commonly used in communications at frequencies above 10MHz. A good example is the common TV antenna.

Z - Zulu time

Identifies Coordinated Universal Time, synonymous with GMT (Greenwich Meridian Time).

Z-Modem

A file transfer protocol based on X-Modem. The Z-Modem and Y-Modem protocols were designed by Chuck Forsberg to add batch transmission, and variable data block size. Z-Modem is considerably faster than Y-Modem and has better error checking capability.

Z-Wave

Used primarily within home automation and associated with the IoT (Internet of Things), Z-Wave is a communication protocol providing short range, low latency data transfer.

Zero-bit insertion

A bit stuffing technique used in some telecommunication protocols. It ensures that six consecutive 0 bits never appear between flags.

ZigBee

This is a communication protocol based upon the IEEE 802.15.4 standard providing connectivity within the PAN (Personal Area Networking) sphere. It supports low power consumption, low data rates and a relatively low cost and is often associated with the IoT (Internet of Things).

zip

Zip is a compression utility used to create.ZIP archives.

Zip - Zoning Improvement Plan

The ZIP codes are numeric codes used as postal codes in the United States. They identify pre-assigned geographic boundaries and make mail sorting and delivery more efficient.

Zombie

A compromised computer that has been loaded with agent software enabling it to controlled remotely as an attack launch point. These are often used in coordination with a large number of similarly affected systems for large traffic attacks such as DoS (Denial of Service).

Zone Timer

A timer used by the mobile station to remove outdated entries from its list of zones in which it has previously registered.

ZUC - Zadoff-Chu

The E-UTRA utilizes Zadoff Chu sequences. These are complex-valued mathematical sequences which generate signal of constant amplitude, whereby cyclicly shifted versions of the sequence comprising the signal do not cross-correlate with each other when the signal is recovered at the receiver.

ZUC - Zu Chongzhi

ZUC is a stream cipher that forms the basis of the 128-EEA3 and 128-EIA3 cryptographic algorithms utilised within LTE networks. The 128-EEA3 is the 128 bit encryption algorithm defined using ZUC and the 128-EIA3 is the EPS Integrity Algorithm designed as a Universal Hash Function using ZUC at its core. Following agreements in 2009 for a requirement for a third LTE encryption and integrity algorithm set, 128-EEA and 128-EIA were designed in China. The algorithm set is based on a core stream cipher algorithm named ZUC, after Zu Chongzhi, a famous Chinese scientist.