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Simple and powerfull GSM + LTE Authentication Calculator: TUAK, Milenage, COMP128-1, 2, 3, Xor Visualyze and Analyze all APDUs between handset and RUIM, (U)SIM All you need to work with SIM, USIM, R-UIM card: build card tree, read, write, export GSM 03.48 compliant solutions for Over-The-Air campaign DES, 3DES, AES, MD5, and other encryptions and hashes Parse an ISO 7816-3 ATR online A collection of Java Card projects in source A simple tool to convert CAP files into IJC format

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10 Base-TBasic Ethernet at 10 Mbit/sec
100 Base-TEthernet running at 100 Mbit/sec
1000 Base-TEthernet running at 1,000 Mbit/sec
128QAMQAM with 7 bits per symbol.
16QAMQAM with 4 bits per symbol.
1GFirst Generation. Refers to analog cellular systems
1xA cdma2000 notation that indicates that one carrier is being used. Compare with 3x
1XRTTcdma2000 operating mode at basic chip rate (1.2288 Mcps). The theoretical top speed is 153 kbps
2GSecond Generation. Refers to digital cellular and PCS wireless systems oriented to voice and low speed data services
2RReceive, Reshape (an optical signal). See 3R
32QAMQAM with 5 bits per symbol.
3GThird Generation. Refers to the next generation of wireless systems - digital with high speed data. Being standardized by 3GPP and 3GPP2
3GiA3G Internet Appliance
3GPP3rd Generation Partnership Project for W-CDMA (GSM)
3GPP23rd Generation Partnership Project for cdma2000
3GSP3G Service Provider
3RReshaping, Retiming, Reamplifying (an optical signal). See 2R
3WCThree Way Call
3xA cdma2000 notation that indicates that three carriers are being used. Compare with 1x. Not widely implemented. Although this allows higher maximum speeds, the average speed per user will not change significantly
3XRTTcdma2000 operating mode at 3 times the basic chip rate of 1.2288 Mcps
64QAMQAM with 6 bits per symbol.
802.11An IEEE committee that standardizes a wireless Ethernet replacement technology in the ISM band. 802.11b is most commonly implemented and runs at approximately 10 Mbps in the 2.4GHz band. 802.11a runs at 54 Mbps in the 5 GHz band. 802.11g provides 24 Mbps in the same band as 802.11b.
802.11aA WiFi WLAN variant that is higher speed (54 Mbps) than 802.11b. Because it also operates in a different frequency band it has proven less popular than 802.11g which offers higher speed in the same band as 802.11b thus providing a simpler migration strategy. The range of this protocol is also lower and the LOS requirements more stringent. See ADRC
802.11bIEEE Wireless LAN system providing throughput of about 11 Mbps but see ADRC
802.11cAn IEEE standard for network interoperability between WLAN protocols
802.11dAn IEEE standard for operation of their WLAN protocols outside the normal frequency bands (e.g. due to the unavailability of those bands in some countries)
802.11eAn IEEE standard for QoS in their WLAN protocols 802.11a, 802.11b, 802.11g and 802.11n
802.11fAn IEEE standard for interconnection between wireless APs
802.11gA second generation version of WiFi providing 54 Mbps raw throughput (typically a user data rate of about half that) in the same 2.4 GHz frequency band as 802.11b. This gave it an advantage over 802.11a which had similar performance but operated in a different frequency band.
802.11hAn IEEE standard for spectrum and transmit power management for their WLAN protocols
802.11iEnhanced security for IEEE WLAN protocols
802.11jAn adaptation of 802.11 WLAN protocols to the Japanese 4.9-5 GHz frequency band
802.11kA proposed IEEE standard for RRM
802.11mA group for editorial maintenance of IEEE 802.11 WLAN standards
802.11nA future IEEE WLAN protocol that promises raw data rates of 540 Mbps in either the 2.4 GHz or 5 GHz band and thus will likely eventually replace 802.11a, 802.11b and 802.11g. The protocol is scheduled for completion in 2009. See EWC
802.11pA proposed IEEE standard for ITS. Also known as WAVE
802.11rA proposed IEEE standard for handoff between APs
802.11sA proposed IEEE standard for mesh networking
802.11tA proposed test specification for IEEE WLAN standards
802.11uA proposed standard for authorization of users on IEEE WLANs
802.11vA proposed wireless network management standard for IEEE WLAN protocols
802.11wA proposed standard for the protection of system management information in IEEE WLAN protocols
802.11yA proposed standard for operation of IEEE WLAN protocols in the 3.65-3.7 GHz frequency band
802.15See Bluetooth
802.16IEEE WiMax radio interface.
802.3IEEE standard for Ethernet
8PSKPSK with 8 states, allowing the coding of 8 bit combinations. It is used in EDGE.
8QAMQAM with 3 bits per symbol.
911The ES service code in many parts of the United States, Canada and a few other countries.
A(2)An IP host address
A-bisInterface between BTS and BSC
A-GPSAssisted GPS. Network provides information to mobile device to acquire satellite signals and may assist with processing of received data
A-interfaceInterface between the MSC and BS
A-KeyThe primary CAVE authentication key, used to generate SSD
A/DAnalog/Digital. Usually used in the context of conversion from analog to digital (or vice-versa)
A3GSM authentication algorithm
A5GSM data encryption algorithm
A5/3An encryption algorithm for GSM and EDGE
A8GSM voice encryption algorithm. Used to generate Kc
AAAAuthentication, Authorization and Accounting entity. See RADIUS and Diameter
AALAAL Adaptation Layer
ABNFAugmented BNF. Defined in RFC 2234
ABRAverage bit rate
ABSAlternate Billing Service
ACAuthentication Centre. Stores information for authenticating mobiles, and encrypting their voice and data transmissions
ACCAnalog Control Channel. See FSK
ACCMAsynchronous Control Character Map
ACCOLCAccess Overload Class
ACCTCDMA Access Control by Call Type
ACDAutomatic Call Distributor. Distributes incoming calls to one of a number of people equally able to handle them (e.g. for customer service)
ACELP(1)Adaptive CELP
ACELP(2)Algebraic CELP
ACFAuthentication Control Function
ACGAutomatic Code Gapping. A method of shedding load in telecommunications systems
ACHAccess Channel
ACKAcknowledgement signal
ACLRAdjacent Channel Leakage Ratio. The ratio of the on-channel transmit power to the power measured in one of the adjacent channels. An important W-CDMA parameter.
ACMSS7 ISUP Address Complete message. Response to IAM
ACPAdjacent Channel Power
ACREAuthorization & Call Routing Equipment. Used for routing calls to cellular phones with a 'cordless' mode
AD(1)Abbreviated Dialing
AD(2)Architecture Document
ADAAdvertising Agent. Provides information to a MS on the services provided by a 3G network
ADDSApplication Data Delivery Service. See SMS
Adjacent Channel InterferenceInterference from signals at slightly different frequencies
ADNAbbreviated Dialing Numbers
ADPCMAdaptive Differential PCM
ADRCAggregate Data Rate Caveat. A warning that most wireless data rates are aggregate, meaning that all users share the bandwidth, and often they are raw rates higher than the actual user throughput could ever be even on an unloaded system. It is probably good to start by dividing the raw rate by a factor of two to obtain the total user throughput rate and then further divide by the average number of simultaneous users (not connected users, but the number who are likely to be simultaneously transmitting)
ADSAsynchronous Data Service
ADSLAsymmetric DSL. Bit rates are higher from the network than from the client
AdSpecIETF Advertisement Specification
AEGAsian Expert Group. A WAP Working Group
AESAudio Engineering Society
AFApplication Function.
AFLTAdvanced Forward Link Trilateration. A geolocation technique that utilizes the mobile station's measured time of arrival of radio signals from the base stations (and, possibly, other terrestrial measurements)
AFRCNGSM Absolute radio frequency channel number
AFSKAudio FSK. Communication by changing frequencies in the audio band rather than RF. Used by MF, DTMF
AGCHGSM Access Grant Channel. The traffic channel assignment information is sent to the mobile on this channel.
AGPSNetwork Assisted GPS. Land station assists mobile in acquiring its position
AGWAccess Gateway
AH(1)Authentication Header
AH(2)Answer Hold. Service that allows an incoming call to be placed on hold without answering it first. Closely related to USCF
AHAGTIA TR-45 ad hoc Authentication Group
AIAir Interface
AICHAcquisition Indicator Channel
AINAdvanced Intelligent Network. Telcordia version of IN
Air InterfaceSynonym for Radio Interface.
AKAnonymity Key. In AKA it is derived from RAND using f5.
AKAAuthentication and Key Agreement. New generation of security being developed for 3GPP2 CDMA systems and 3GPP UMTS systems. Parts may also be applied to GSM
AlertA command to a mobile to notify the user of an incoming call or message
ALIAutomatic Location Information. A database that contains information about the location of emergency callers
AMAmplitude Modulation. See FM
AMAAutomatic Message Accounting. See CDR
AMFAKA Authentication Management Field. May indicate the algorithm and key used by the current authentication system.
AMIAlternate Mark Inversion
AMPSAdvanced Mobile Phone Service. TIA analog cellular, and all standards that retain compatibility with it (NAMPS, D-AMPS, CDMA). Standardized in EIA/TIA-553
AMRAdaptive MultiRate Voice Coder. Proposed for use in GSM and UMTS. Bit rates vary between 12.2 and 4.75 kbps
AMR-WBAMR wide (audio) band Voice Coder chosen for UMTS. Developed by Nokia and Voiceage. Has 9 different bitrates
AMTAAmerican Mobile Telecommunications Association
ANAccess Network
analogTransmission of information through a continuously variable signal. Compare with digital
analogueAlternate (British) spelling of analog
Anchor MSCThe first MSC involved in a wireless call
ANI(1)Automatic Number Identification. Provision of charge number during a call to allow toll calls without operator intervention
ANI(2)Access Network Identifier
ANI IIANI Information Digits. Describes the type of phone being used to call (e.g. residential line or payphone).
ANMSS7 ISUP Answer Message
ANSIAmerican National Standards Institute
ANSI-136ANSI version of the TDMA air interface standard. Replaces IS-136. Correct name is TIA-136
ANTADSL Network Termination
AOAAngle of Arrival. A technique for locating a radio by estimating the angle of signal arrival at multiple points. Compare with TOA
AoCAdvice of Charge
AP(1)Application Part (of a protocol)
AP(2)Access Point. An 802.11 BS
APCOAssociation of Public Safety Communications Officials
APDUApplication PDU
APIApplication Programming Interface
APLMNAssociated PLMN
APMApplication Transport
APMNAssociated PMN
APNAccess Point Name. In a GPRS network, the domain name referring to an external packet network
ARCHAccess Response Channel
ARIBAssociation of Radio Industries and Businesses. Responsible for standardization of telecommunications protocols in Japan
ARMARQ Response Mode
ARP(1)Authorized Receipt Point. The sole entity authorized to settle and exchange roamer charges and revenue for a carrier
ARP(2)IETF Address Resolution Protocol. Binds the physical (MAC) address of a device to an IP address on a local network (e.g. ethernet subnet).
ARPUAverage Revenue Per User/Unit
ARQAutomatic Repeat Request. A method of error correction where the receiver detects errors, and requests retransmission from the sender.
ASInternet Application Server. Handles applications for a range of addresses (e.g. a telephone switch)
ASCIIAmerican Standard Code for Information Interchange. The most commonly used method for encoding text in 8 bit characters. See UNICODE for more complex alphabets and the obsolete EBCDIC
ASEApplication Service Element
ASICApplication Specific Integrated Circuit. A computer chip that is customized for a special purpose application
ASN.1Abstract Syntax Notation 1. A formal, textual, representation of a protocol message set
ASPAS Process
ASRAutomatic Speech Recognition
Assisted GPS(1)A class of GPS receiver that uses information from another source to make positioning quicker. This is common in cellular phones, where the cellular BS transmits additional information to make the acquisition of satellites quicker and may offload some of the calculations.
AsynchronousData is transmitted only when needed. At least one bit is needed to indicate the start of transmission (known as a start bit). Compare with Synchronous
ATAccess Tandem. A switch that can be used to reach a variety of IXCs
ATIAccess Terminal Identifier
ATISAlliance for Telecommunications Industry Solutions. Parent organization for the T1 standards committees and many telecom industry groups, such as OBF
ATMAsynchronous Transfer Mode. Transmits data as 53 byte units using a connection-oriented protocol at speeds up to 2.488 Gbps
ATPAccess Transport Parameter (also Adenosine Tri-Phosphate :)
ATSAbstract Test Suite
AuCGSM term for AC
AUTHAn OMT bit that turns mobile authentication on or off for all mobiles within a cell
AUTHBSAuthentication Response from the BS
AuthenticationProving the identity of an individual or application (e.g. MS)
Authentication EnhancementsImprovements to network based authentication (TIA/EIA-41) defined in IS-778
Authentication VectorSee Quintet and Triplet
AUTHRAuthentication Response. The output of CAVE when RAND is used as a global challenge
AUTHUAuthentication Response to Unique Challenge
AUTNAKA Network Authentication Token. Composed of SQN (concealed), AMF and MAC
AVAuthentication Vector
AVCAnalog Voice Channel
AVPAttribute Value Pair. A method of encoding parameters that includes the length of the data, the attribute (parameter) type (usually fixed length) and the attribute value. cf TLV
AWGNAdditive White Gaussian Noise
AWIAlert with Information; used to transmit data while alerting an MS
AWSAn FCC term for IMTS-2000
B-SMSBroadcast SMS
B/IBusy/Idle bit
B8ZSBipolar with 8 Zero Substitution. Replaces an all-0 octet by one containing two BPV
Baby Bellsee RBOC
BackhaulRouting trunks from a cellsite to an MSC before routing to the PSTN.
badputA cute name for wasted bandwidth. Bandwidth = goodput(throughput) + badput + unused bandwidth
BAFBilling Automatic Message Accounting Format. The CDR/AMA format used by most US wireline telecom carriers
BAICBarring of All Incoming Calls
BAOCBarring of All Outgoing Calls
BARGGSMA Billing, Accounting and Roaming Group
BarringRefusal to allow certain types of calls
BasebandThe signal(s) used to modulate the radio channel in the transmitter, and which are recovered by the receiver by demodulating the received radio channel.
BATSBroadcast Air-interface Transport Service used by TIA/EIA-136
BBITBest Breakfast In Town.
BCCHBroadcast Control Channel
BCDBinary Coded Decimal. Digits 0-9 are encoded as 4 bit numbers (nibble), so two fit within a byte. See TBCD
BCEBase Station Central Equipment. See BSC
BCH(1)Broadcast Channel. A channel transmitted by one (e.g. BS) and received by many (e.g. MS)
BCH(2)Bose, Chaudhuri, and Hocquengham error detection and correction methodology
BCH(3)Basic Call Handling
BCMBasic Call Manager. See WIN
BCMCSBroadcast/Multicast Services for 3GPP2. Contrast with BMC
BCSMBasic Call State Model. A n IN concept
BDBilling Domain
BDNBarred Dialing Number
Bearer capabilityA capability of a transport protocol (e.g. a maximum bitrate or message latency). A Teleservice may be able to use any facility that can provide a specified bearer capability.
BEGBilling Expert Group. A WAP Working Group
Beidou(1)A Chinese GNSS.
BER(1)See Bit Error Rate
BER(2)Basic Encoding Rules. See ASN.1
BGCFBreakout Gateway Control Function. Controls the assignment of resources to IMS sessions in a serving system. Connected to the S-CSCF, MGCF and BGCF
BGPBorder Gateway Protocol of IETF RFC 1771. See EBGP.
BIBBackward Indicator Bit. Indicates when a received MTP frame is out of sequence. See FIB
BIC-RoamBarring of Incoming Calls while Roaming
BICCBearer Independent Call Control. ISUP adapted for use over IP-based transport. Compare with SIP
BIDA SID allocated for accounting purposes. BID's are allocated by Cibernet
bitFundamental unit of information, occupying two discrete states (e.g. 0 or 1)
Bit Error RateThe fraction of binary bits that are received with the wrong value.
BLASS7 ISUP Blocking acknowledgement. See BLO
BLOBBlock of Bits
BluetoothA cable-replacement radio protocol for short distance (5-100 meter) networking at moderate speeds (1 Mbps raw bandwidth for version 1 and 3 Mbps for version 2). Developed by the Bluetooth Consortium and standardized by IEEE 802.15.1
BLVBusy Line Verification
BM-SCBroadcast/Multicast Service Center
BMCBroadcast Multicast Control. See 3GPP TS25.324. Contrast with BCMCS.
BMIBS, MSC and Interworking function
BNFBackus-Naur Form. A precursor to ASN.1 and other meta-language
BNSBilled Number Screening
BOCBell Operating Company
BOICBarring of Outgoing International Calls
BOIC-exHCBOIC except to HC
Border RouterAn IP Router that connects to routers in other networks using the EBGP protocol.
BPBit Position
bpsBits per second. A measure of the speed of a transmission link
BPSKBiphase Shift Keying
BPVBi-Polar Violation. Transmission of two one-bits in a PCM channel (e.g. DS0) with the same polarity (e.g. both positive or both negative). May be deliberately used to indicate all-zero octets. See B8ZS and HDB3
BRBorder Router. Connects a CN with peer networks
BREWBinary Runtime for Wireless
BRIBasic Rate Interface (64 kbps). See DS0
Broadcast SMSShort messages sent to multiple mobiles in multiple cells, requiring only one message per cell
BSBase Station (includes BTS and BSC)
BSCBase Station Controller. The 'brains' of a base station, controlling the radio equipment in the BTS
BSFBootstrapping Function
BSICBS Identity Code. Color code used by GSM systems to ensure that the source of a frequency transmission can be identified, in areas where multiple cells transmitting on the same frequency can be received
BSMCBase Station Manufacturer Code
BSN(1)Backward Sequence Number. The sequence number of the last correctly received MTP frame received. Contrast with FSN
BSN(2)BCMCS Serving Node
BSS(1)BS Subsystem
BSS(2)Basic Service Set. An 802.11 network.
BTBurst Type
BTABasic Trading Area
BTSBase Transceiver System (radio portion of BS)
BTTCBroadcast SMS
BWIFBroadband Wireless Internet Forum. A program of IEEE-ISTO
BXAUS DoC Bureau of Export Administration. Administers EAR
byteAn 8 bit unit of data storage. See octet
C-PDScdma2000 Packet Data Service
C/ICarrier to Interference Ratio
C7See CCS7
CA(1)Certificate/Certification Authority
CA(2)Collision Avoidance
CACCarrier Access Code. Identifies a long distance carrier. 101+CIC
CALEAUS Communications Assistance for Law Enforcement law. Requires that telecommunications carriers provide for surveillance (aka wiretaps) at the switch site
CAMACentralized Automatic Message Accounting
CAMELCustomized Applications for Mobile Networks Enhanced Logic based on CAP. IN capabilities for GSM. Compare with WIN
Candidate MSCAn MSC being considered as the Target MSC of a handoff
CAP(2)Carrierless Amplitude and Phase modulation
CAP(3)Competitive Access Provider
CAPCSCellular Auxiliary Personal Communications Service
CARCommitted Access Rate. An IP method to achieve higher QoS
CARECustomer Account Record Exchange. Sent from a LEC to an IXC to establish a long distance account for a customer
Care-of AddressThe address that a Home Agent forwards packets to for handling by the Foreign Agent in MIP
CarnivoreUS FBI ISP wiretapping box, including a processor and removable hard drive to capture internet sessions (email, web access etc.).
CASCall Associated Signaling. See ISUP. Contrast with NCAS
CATSmart Card Application Toolkit
CATPTCDMA UIM Card Application Toolkit Protocol Teleservice
CATR(1)China Academy of Telecommunication Research of MII. A government owned research institute that participates in the development of standards. Formerly RITT.
CAVETIA Cellular Authentication and Voice Encryption Algorithm
CBCell Broadcast
CBCCB Center
CBMICB Message Identifier
CBRConstant Bit Rate
CBSGSM/W-CDMA Cell Broadcast SMS
CC(1)E.164 Country Code
CC(2)GSM Call Control protocol
CC(3)Content of Communications (for LAES)
CCACommon Cryptographic Algorithm
CCATCDMA Card Application Toolkit. Specifies communications between a CDMA R-UIM and the ME
CCBUS FCC Common Carrier Bureau
CCBSCall Completion to Busy Subscriber
CCCHGSM Common Control Channels - PCH, RACH, AGCH
CCF(1)Call Control Function (IN term)
CCF(2)Charging Collection Function (3GPP)
CCHControl Channel
CCITTInternational Telegraph and Telephone Consultative Committee. Precursor to ITU. See ITU-T and ITU-R
CCNRCall Completion on No Reply. See CFNA
CCPCompression Control Protocol
CCPDCommon Channel Packet Data
CCPNCall Completion to a Ported Number. See LNP
CCR(1)SS7 ISUP Continuity check request
CCR(2)Class Conformance Requirement
CCSCommon Channel Signaling
CCS7ITU-T version of SS7
CCSAChina Communications Standards Association. Successor to CWTS.
CCSCCellular Carrier Specific Code (e.g. #123)
CCSHCDMA Code Combining Soft Handoff
CCSSCall Completion Service Setup
CCVCredit Card Validation
CCWCancel Call Waiting
CDCollision Detection
CDATACharacter Data, such as a quoted text string. Used in XML and derivative protocols such as WML
CDCPCall Detail Collection Point. See TIA/EIA-124
CDGCDMA Development Group
CDGPCall Detail Generation Point
CDISCall Detail Information Source. An MSC or other entity that produces proprietary CDR's
CDMACode Division Multiple Access. Implemented in AMPS-compatible systems by IS-95. Also see W-CDMA
CDMA-PAMRA CDMA-based PAMR system.
cdma2000Trade name for CDMA air interface standards aimed at 3G requirements, including IS-2000. It operates in 1.25 MHz carriers at 1.2288 Mcps. There is some debate about whether the "CDMA" should be upper or lower case :)
cdmaOneTrade name for first generations of CDMA air interface standards, including TIA/EIA-95. Operates in pairs of 1.25 MHz channels
CdPACalled Party Address
CDPDCellular Digital Packet Data. A protocol that uses 30 khz AMPS channels to transmit packets of data. Standardized in TIA/EIA/IS-732
CdPNCalled Party Number. The DN of the party receiving a call
CDRCharging Data Record or Call Detail Record
CDRPCall Detail Rating Point
CDVCCCoded Digital Verification Color Code
CEASACellular Emergency Alert Systems Association. Promotes the use of emergency alerts over cell phones.
CEGCarrier Expert Group. A WAP Working Group
cellThe coverage area of a single radio cellsite or sector in a cellular or PCS system
cellularA radio concept that allows the multiplication of capacity by using many low-power cell to cover an area, reusing frequencies as much as possible
CELPCode Excited Linear Prediction
CENELECEuropean Committee for Electrotechnical Standardization
CEPCell Equipment Processor
CEPTConference des administrations Europeannes des Postes et Telecommunications
CEWSCell Work Station. Software running here supports termination of the LAPD links to the BTS. A minimal OA&M application is included to support maintenance of the A-bis interface processes and to route OA&M messages to/from the BTS. Call Handling software derives directly from the CEP and PPP of the BCE.
CFCollection function. LEA that collects J-STD-025 data
CFBCall Forwarding when subscribing telephone is busy
CFNACall forward on no-answer (and, usually, also on no page response). See CFNRc and CFNRy
CFNRcCall forward when mobile not reachable. See CFNA
CFNRyCall forward when mobile is not answered. See CFNA
CFUCall Forwarding Unconditional (i.e. every incoming call will be forwarded)
CGCharging Gateway
CGBSS7 ISUP Circuit group blocking
CGBASS7 ISUP CGB acknowledgement
CGI(1)Common Gateway Interface
CGI(2)GSM Cell Global Identification. Composed of LAI + CI
CGLCalling Geodetic Location. The position of a mobile phone, as transmitted through various signaling protocols. See GAD
CGLPSS7 ISUP Calling Geodetic Location Parameter (i.e. Latitude and Longitude)
CgPNCalling Party Number. The DN of the party initiating a call
CGSACellular Geographic Serving Area. MSA or RSA
CGUSS7 ISUP Circuit group unblocking
CGUASS7 ISUP CGU acknowledgement
CGVoPCarrier Grade Voice over Packet. See VoIP
CHAPPPP Challenge Handshake Authentication Protocol. Use of RADIUS to authenticate a terminal without sending security data in the clear. Compare with PAP
cHTMLCompact HTML. Use by iMode. See also WML and XHTML
ChurnThe rate at which subscribers leave one wireless carrier to go to another. A major expense for carriers
CIGSM Cell Identity. A 16 bit number identifying a cell within an LAI
CIBERCellular Intercarrier Billing Exchange Record. Format used for exchange of wireless billing records. Maintained by Cibernet Corp
CibernetA subsidiary of the CTIA responsible for facilitating billing aspects of roaming
CICCarrier Identification Code. See CAC
CiphertextEncrypted data. Compare with Plaintext
CIR(1)Synonym for C/I
CIR(2)Committed Information Rate. Bandwidth associated with a frame relay PVC
Circuit-switched dataData transmitted over a dedicated (although usually virtual) channel. The destinatioin address is implicitly defined by the (virtual) circuit that is selected
CISCCRTC Interconnection Steering Committee
CITELCommission InterAmericanna de Telecommunications Association. A Latin American telecommunications association
CKCipher Key. In AKA, it is derived from RAND using f3 and applied to traffic using f8
CKSNCK Sequence Number
CLASSCustom Local Area Signaling Services. A package of features offered by wireline carriers
ClearinghouseA central point for the gathering and redistribution of records, such as billing records
CLECCompetitive LEC. A new entrant in a market previously limited to one carrier. Some wireless carriers may qualify for this designation
CLICalling Line Identity. See CgPN
CLIPCalling Line Identification Presentation. See CNIP
CLIRCalling Line Identification Restriction. See CNIR
CLLICommon Language Location Identifier. An ASCII identifier of a telephone switch or calling area.
CLNPConnectionless Network Protocol
CLNSConnectionless Network Service
CMGSM Connection Management
CMACControl Mobile Attenuation Code
CMCCellular Mobile Carrier. A generic term used to classify carrier class cellular systems
CMEACellular MEA. Based on CAVE
CMIPCommon Management Information Protocol
CMRSCommercial Mobile Radio Service
CMSPIndian GSM licence. Replaced by UASL.
CMTCellular messaging teleservice. A service based on SMS that is similar to that provided by alphanumeric pagers
CMWNCancel Message Waiting Notification
CNCore Network. Protocols for this include GSM MAP and ANSI-41
CNACanadian Number Administrator. Administers telecom numbering resources in Canada, under the oversight of the CRTC.
CNAMECanonical Name. A basic Domain name that may be pointed to by multiple aliases
CNAPCalling NAme Presentation. A terminating party feature. Overridden by CNAR
CNARCalling NAme Restriction. An originating party feature
CNDBCalling Name Database
CNIPCalling Number Identification Presentation. A terminating party feature. Overridden by CNIR
CNIRCalling Number Identification Restriction. An originating party feature
COCentral Office
Co-channel InterferenceInterference from other signals using the same radio channel
COACare-Of Address
codecVoice coder and decoder. See vocoder and Voice Coder
COFETELComision Federal de Telecomunicaciones de Mexico
COLPConnected Line Identification Presentation. See COLR, CNIP
COLRConnected Line Identification Restriction. See CNIR, COLP
COMETIETF SIP Preconditions Met message
ConfidentialityKeeping information private (e.g. by encryption)
CONSConnection-Oriented Network Service
Control ChannelA cellular or PCS channel that broadcasts information about a cell to mobiles that are not currently in a call
CORBACommon Object Request Broker Architecture
CORDCellular Operations Record Distribution
CoSClass of Service. Method of managing traffic by grouping similar types (e.g. voice, video, email)
COTP(1)Connection-Oriented Transport Protocol. Specified by ISO 8073. An alternative to TCP that is packet-based rather than stream-based, meaning that the transport protocol, rather than the application protocol, keeps packets of data separate. Despite this, most systems use TCP with the ITOT protocol on top if necessary. Port 102 is reserved for use by this protocol.
COUNTCall History Count. An internal mobile counter that can be used to detect the presence of clones
COWSCommon Work Station. Software running in the Common Work Station element supports termination of the SS7 links to the MSC as well as the X.25 links to the OMC (including the OSI stack) and any PSDN services. The majority of the OA&M software is found here.
CPDECentralized PDE
CPECustomer Premises Equipment. A standard telephone is an example of telecommunications equipment that is usually located at the customer's site.
CPGSS7 ISUP Call ProGress Message
CPGACost per Gross Addition. The cost to a carrier of adding one subscriber
CPLIETF Call Processing Language. An XML-based language for describing internet telecommunications services.
CPPCalling Party Pays. The calling party pays for calls to mobile, not the mobile receiving the call. cf TPP
CQM(1)Channel Quality Measurement
CQM(2)Core Quality of Service Manager. Obsolete. See PDF
CRChange Request. A description of a problem in a standard (error, limitation, ambiguity or restriction) and a description of how it should be fixed
CR-LDPConstraint-based Routing LDP. See MPLS
CRCCyclic Redundancy Code (or check). Included in many digital protocols to check for errors in transmitted messages
CRDBCoordinate Routing DataBase. Proposed for E911 systems to convert a location into routing information
CRLCertificate Revocation List
CRM(1)Customer Resource Management
CRM(2)Channel Request Message
CRTCCanadian Radio-television and Telecommunications Commission
CRTPCompressed Real-Time Transport Protocol. Provides compression (and decompression) of RTP, UDP and IP headers.
CryptosyncExternally-provided synchronizing information for cryptoalgorithms (ciphers) that allows an encryptor at one end to uniquely encrypt each block of content into ciphertext, and yet allows a decryptor at the other end to properly decrypt the ciphertext to yield the original plaintext. Cryptosync often takes the form of the output of a binary counter
CS(1)IN Capability Set
CS(2)Circuit switched. Contrast with PS
CS-2IN Capability Set 2
CS-ACELPConjugate Structure ACELP
CSACanadian Standards Association
CSCCustomer Service Center
CSCFCall Session Control Function. Controls the assignment of resources from the home system. See I-CSCF, P-CSCF and S-CSCF
CSCNCanadian Steering Committee on Numbering. A working group of the CRTC CISC
CSDCircuit switched data. Data travels between two devices using a fixed amount of bandwidth allocated for the duration of the data call. Compare with Packet data that uses shared bandwidth to service multiple users. Packet data can be more efficient (except when the overhead of identifying and routing packets is greater than the savings) but the performance is less predictable.
CSFPCoded Superframe Phase
CSICAMEL Subscription Information
CSMACarrier Sense Multiple Access
CSMA/CDCSMA with CD (also known as CA). Ethernet devices use this to minimize collisions by checking the line before sending
CSRCContributing Source
CSSCascading Style Sheets. See HTML
CSUChannel Service Unit. Unit that interfaces between the telephone company and a private network
CTCall Transfer
CTCPCompressed TCP. Provides compression (and decompression) of TCP and IP headers.
CTIACellular Telecommunications Industry Association
CUGClosed User Group. Calls are restricted to within the group
CWCalling Waiting
CWTACanadian Wireless Telecommunications Association
CWTSChinese Wireless Telecommunications Standards. Replaced by CCSA
D DigitThe fourth digit of an NANP phone number. Currently restricted to the values 2-9 to allow 7 digit dialing
D-AMPSDigital AMPS (IS-54 and IS-136 TDMA)
D/LDownlink (e.g. from base station to mobile). Compare with U/L.
DAPX.500 Directory Access protocol
DataTACData TAC. A Motorola wireless data system. Formerly known as Ardis.
dBDecibel. 10 times the logarithm of the value in base 10
dBiDecibels relative to isotropic radiator. A measurement of the gain of an antenna.
dBmDecibels referenced to one milliwatt
DCCDigital Color Code. A number assigned to a control channel used to limit erroneous accesses
DCCHDigital Control Channel. The control channel used by IS-136 and TIA/EIA-136 D-AMPS systems
DCEData Communications Equipment (i.e. a computer)
DCFDRM Content Format
DCHDedicated Channel
DCNData Communications Network
DCS(1)Data Coding Scheme
DCS(2)Digital Cross-Connect System
DCS(3)European PCS frequencies in the 1800 MHz range.
DDMData Description Method
DEAUS Drug Enforcement Agency
DECTDigital Enhanced Cordless Telephony
DESData Encryption Standard. A commonly used encryption method, usually used with 56 bit keys. See AES, TDES.
DF(1)UIM Dedicated File. Compare with EF and MF
DF(2)Delivery Function (for LAES)
DFCADynamic Frequency and Channel Allocation. Dynamic assignment of radio channels to optimize capacity. Proposed for GSM, but not yet implemented.
DFPDistributed Functional Plane NRM
DHCPDynamic Host Control Protocol. Allows automatic assignment of IP addresses on a network
DHKEDiffie-Hellman Key Exchange. A method of securely exchange encryption keys over an insecure interface
DiameterAn IETF AAA protocol designed to be twice as good as RADIUS. Unlike its predecessor it supports MIP and uses SCTP (or TCP) instead of UDP for more reliable transport. It uses IPSEC and TLS instead of a shared secret.
DIDDirect Inward Dialing. Directs all calls to a block of numbers to a PBX
Diffie-HellmanA secure key exchange mechanism
DiffservDifferentiated Services. Different QoS for different types of traffic (e.g. voice, video, email). See IETF RFCs 2474 and 2475
digitalTransmission of information through a signal that can take on only certain discrete values (e.g. bits with values 0 or 1). Compare with analog
DisconnectionThe end of a call. Not to be confused with Termination of a call or the Release of a trunk
DLDownlink. Radio link from network 'down' to terminal. Compare with UL
DLCDigital Loop Carrier. A single digital facility (e.g. T1 or T3) carrying multiple lines to a business or other large customer
DLCIData Link Connection/Circuit Identifier
DLPDiscrete Logarithm Problem. Used in some cryptography systems
DMACDigital Mobile Attenuation Code
DMHData Message Handler. An informal name for the TIA IS-124 standard
DMODirect Mode Operation. Group calling capabilities, e.g. PTT, of a PAMR system. Compare with TMO.
DMTDiscrete Multi-Tone line code being proposed for VDSL. Compare with QAM/CAP
DMUDynamic MIP Key Update. A secure and efficient mechanism for distributing and updating Mobile IP (MIP) cryptographic keys in cdma2000 networks (including High Rate Packet Data which is often referred to as 1xEV-DO). Because the Dynamic Mobile IP Key Update (DMU) procedure occurs at the IP layer directly between the MIP MN and RADIUS or Diameter AAA Server, it may be used to securely bootstrap the MN-AAA key (and other cryptographic keys) in MIP networks using any RAN technology.
DN(1)Directory Number. The number dialed to terminate a call to a phone
DN(2)Domain Name (e.g. cnp-wireless.com).
DNICData network identification code
DNISDialed Number Identification Service. Identifies the called (not calling) number. Only useful when multiple numbers terminate at the same location (e.g. a regular phone number, 1-800 and 1-900 number). Contrast with CNIP
DNSInternet Domain Name Service/System. See RFC 1035
DOADead On Arrival
DoCUS Department of Commerce
DOIDomain of Interpretation
DOJUS Department of Justice
DomainA portion of the internet (e.g. cnp-wireless.com)
Donor SwitchThe switch from which a number has been ported. See LNP
DownlinkPath from base station to terminal
DPWIN/CAMEL Detection Point
DPC(1)Destination Point Code for an SS7 message
DPC(2)Downlink Power Control
DPCCHDedicated Physical Control Channel
DPCHDedicated Physical Channel
DPDCHDedicated Physical Data Channel
DPSKDifferential PSK
DQPSKDifferential Quadrature PSK
DRACDynamic Resource Allocation Control
DRMDigital Rights Management
DSDirect Spread. See CDMA
DS-CDMADirect Sequence CDMA
DS0Digital Signal Level 0. A 64 kbps digital link used to carry a single voice conversation or signaling traffic for multiple calls/trunks. In ANSI networks, 8 kbps is usually reserved for in-band signaling (on-hook/off-hook etc.), reducing the bandwidth to 56 kbps
DS1Digital Signal Level 1. A 1.544 Mbps signaling link carrying 24 DS0 channels
DS1CDigital Signal Level 1C. A 3.152 Mbps signaling link carrying 48 DS0 channels
DS2Digital Service, Level 2. 6.312 Mbps. Carries 96 DS0 channels (4 DS1 channels)
DS3Digital Service, Level 3. 44.736 Mbps. Carries 672 DS0 channels (28 DS1 channels)
DSADigital Signature Algorithm
DSCHDownlink Shared Channel
DSFDispersion Shifted Fiber
DSIDigital Speech Interpolation
DSLDigital Subscriber Line. See SHDSL, ADSL, SDSL, VDSL
DSLAMDSL Access Multiplexer
DSMADigital Sense Multiple Access. Access to a shared resource is controlled by sensing a digital signal before attempting an access. Used by CDPD
DSPDigital Signal Processing/Processor
DSR(1)Distributed Speech Recognition
DSR(2)Direct Signal Reporting
DSS-1Digital Subscriber Signaling System No. 1
DSU(1)Digital Service Unit. Interface between the terminal equipment (DTE) and the service provider's facilities
DTCDigital Traffic Channel
DTCHDedicated Traffic Channel
DTDDocument Type Definition. An XML grammar specification
DTEData Terminal Equipment
DTMDual Transfer Mode. Simultaneous voice and data connections with GSM and EDGE, bringing some 3G services to a 2G system (without the wide pipe though!)
DTMFDual Tone Multifrequency. Tone signaling used by phones
DTNDeflected-To Number
DTXDiscontinuous Transmission. A mobile only transmits when the user is talking. This saves battery life, but can introduce some choppiness into conversations
Dual-bandA mobile that can support two different frequency ranges. Compare with Dual-mode
Dual-modeA mobile that can support two different technologies. Compare with Dual-band
DUPSS7 Data User Part
DVCCDigital Verification Color Code
DWDMDense Wave Division Multiplexing
E-Mail(1)Electronic Mail
E-OTDEnhanced Observed Time Difference. A positioning technology based on software within wireless phones combined with their existing signal measurement capabilities. Compare with the purely network-based AOA, TOA and TDOA
E-SMREnhanced SMR. See iDEN
E.118The ITU-T recommendation for ICCID.
E.164ITU-T dialing plan standard. Numbers are composed of CC+NSN (NDC + NDC)
E.212ITU-T mobile identification number standard
E.214ITU-T standard that allows an E.212 IMSI number to be mapped onto an E.164 number to allow routing through SS7 networks. Unfortunately, this mapping does not work in North America
E1A digital link carry 32 DS0 channels, with two used for signaling purposes. Used mostly outside North America. Compare with T1
E911Enhanced 9-1-1 service. Provides the identity and the approximate location of the calling phone
EA(1)Economic Area. A geographical area used by the US FCC to license the AWS A band.
EA(2)Equal Access
EACCEmergency Area Congestion Control
EAPIETF Extensible Authentication Protocol, RFC 4017
EAP-TLSEAP Transport Layer Security. Public key encryption for WiFi.
EAP-TTLSEAP Tunneled Transport Layer Security. Provides mutual authentication of WiFi network and client through the use of network-side certificates.
EARExport Administration Regulations. Replace ITAR for control of export of encryption technologies
EASEmergency Alert System. A US government system that transmits audio or text information about emergencies (mostly weather) to radio and TV stations. There has been some talk about extending this to wireless phones via broadcast SMS
EbEnergy of an information bit
EBCDICExtended Binary Coded Decimal Interchange Code. IBM's byte code for letters, numbers and special characters. Not as good as ASCII because, for example, letters are not all in a single group, making software more awkward
EBGPExternal BGP. BGP between routers in two different networks.
EBNFExtended BNF. Used to define XML, for example.
EBSEmergency Broadcast System. See EAS
ECExchange Carrier
ECCElliptic Curve Cryptography
ECDLPElliptic Curve Discrete Logarithm Problem. See ECC
ECMAEuropean Computer Manufacturer's Association
ECSAExchange Carrier's Standards Association. Renamed ATIS several years ago
ECTExplicit Call Transfer
EDACCDMA Error Detection and Correction coding. See FEC
EDGEEnhanced Data-rates for GSM (or Global) Evolution. Uses 8PSK modulation to increase data rates within the 200 kHz RF bandwidth to a theoretical limit of 384 kbps (474 kbps raw), although per-user rates will be significantly lower because few if any phones can use all 8 available timeslots. A higher speed successor to GPRS. See ADRC
EDIElectronic Data Interchange. Used to transfer business-level data between companies (e.g. invoices, purchase orders). Nowadays, more attention is on XML for this purpose
EDREfficient Data Representation. Assigns one record to represent a block of 1,000 pooled numbers
EDSEnhanced Dialed Service(s)
EESNExpanded ESN. An idea for a 56-bit identifier to replace ESN that never took off. See MEID and EUIMID.
EFUIM Elementary File. Compare with DF and MF
EFIExternal Functionality Interface
EFREnhanced Full Rate. The standard GSM Voice Coder operating at 12.2 kbps
EGNOS(1)European Geostationary Navigation Overlay System. A WAAS to augment GPS and GLONASS in Europe.
EGPRS-136GPRS adapted for use in TIA/EIA-136 networks
EHFCExtended Hyperframe Counter
EIAElectronics Industry Alliance
EIA/TIA-553Analog AMPS cellular standard. Formerly IS-3
EIREquipment Identity Register. Stores information about wireless terminals as opposed to subscriptions. Compare with HLR
EIRPEffective Isotropic Radiated Power
ELCAExtended Local Calling Area. Allows toll-free calls to numbers outside the normal toll-free zone, by arrangement with the terminating (usually wireless) carrier
EMAElectronic Messaging Association.
EMCElectro-Magnetic Compatibility
EMFElectro-Magnetic Field or Electro-Motive Force (Voltage)
EMIExchange Message Interface. A LEC billing record format. Compare with EMR. Contrast with BAF and CIBER
eMLPPEnhanced MLPP. A GSM method for implementing PS
EMRExchange Message Record. A LEC billing record format. Compare with EMI. Contrast with BAF and CIBER
EMSEnhanced Messaging Service. SMS extended to include simple graphics, audio and enhanced text (e.g. fonts). A precursor to MMS
EMTELEmergency Telecommunications for ETSI
ENEuropean Norm (Standard).
enumTelephone Number Mapping to an internet address. A method of converting a phone number into a domain name defined by IETF RFC 2916. Take the full number (including country code), reverse it, put a dot between each pair of adjacent digits, append '.e164.arpa' and, there you have it! This format is easier for DNS systems to handle.
EOEnd Office
EOMEnd Of Message
EP SCPETSI Project Smart Card Platform
EPEEnhanced Privacy and Encryption. A North American TDMA architecture that secures voice, messages, and data through encryption
Ephemeris(1)Information on GPS satellite orbits, used to make the acquisition of satellites more efficient.
ErlangMeasure of traffic load. Calculated as rate at which calls arrive divided by the rate at which they are completed
Erlang BA traffic model used to engineer resource groups when blockage is low, and the average holding time is known
Erlang CA traffic model commonly used for provisioning data circuits
ERMESEuropean Radio Messaging System. An ETSI paging system established in the 1990s. All European countries are supposed to provide spectrum for it.
ERPEffective Radiated Power
ERROR RESULTMessage sent to unsuccessfully end TCAP transaction
ESEmergency Service(s), such as 911
ESAEnhanced Subscriber Authentication. A long term replacement to the TIA CAVE algorithm
ESCEmergency Services Call
ESFExtended Superframe Format. DS1 format that is used for most T1 links
ESIFATIS Emergency Services Interconnect Forum
ESME(1)Emergency Services Message Entity. Entity that receives E911 messages from an MSC (e.g. ALI or S/R)
ESME(2)External SME. Used by SMPP to exchange short messages between incompatible technologies
ESMREnhanced SMR. Allows 'cellular' service as well as traditional SMR services
ESN(1)Electronic Serial Number. 32 bit identifier of an AMPS, CDMA or TDMA mobile. May eventually be replaced by MEID.
ESN(2)Emergency Service Number
ESNEEmergency Services Network Entity. Entity that is connected to an E911 trunk from an MSC (e.g. S/R or PSAP)
ESP(1)Emergency Service Provider
ESP(2)Enhanced Subscriber Privacy. Stronger TIA voice encryption algorithms than those originally provided with CAVE
ESP(3)IETF Encapsulating Security Payload, RFC 2406
ESRDEmergency Service Routing Digits. An NANP number that routes a call to a PSAP and identifies the cellsite or sector that the call originated from
ESRKEmergency Service Routing Key. A temporary phone number that routes an emergency call to the correct PSAP and allows access to information in the ALI
ESZEmergency Services Zone. A geographical region served by a single emergency call answering service.
EthernetA LAN protocol using collision detection to resolve access contention (CSMA/CD). Available in 10Mbps, 100Mbps and 1Gbps variants. Standardized as IEEE 802.3.
ETRETSI Technical Report
ETSEuropean Telecommunication Standard
ETSIEuropean Telecommunications Standards Institute
EUIMIDExpanded UIMID. A larger identifier for a cdma2000 UIM. There are two variants, the "Short Form" which is based on MEID and the "Long Form" based on ICCID. For compatibility with ESN a pUIMID is calculated.
EvDO1x cdma2000 Evolution for High Speed Data Only. See HRPD and EVDV. A high speed CDMA data system. It does not support voice, except as VoIP. Revision 0 promised 2.4 Mbps download, 153 kbps upload on a 1.25 MHz carrier. Revision A was 3.1 Mbps down, 1.8 up. Revision B was 14.7 Mbps download and 4.9 Mbps upload in a 5 MHz carrier and Revision C promises 100 Mbps download and 50 Mbps upload in a 20 MHz carrier. See LTE and ADRC
EVDVCDMA 1x Evolution - Voice and High Speed Data services. Although it is more flexible, it is so far less popular than EvDO
EVMError Vector Magnitude. The difference between the received coordinates of a symbol (defined by phase and amplitude) and the intended position (e.g. what was transmitted). This is a measure of error in digital modulation systems such as QAM.
EVRCEnhanced Variable Rate Voice Coder. An IS-95 voice coder for use on CDMA systems
EWCEnhanced Wireless Consortium. An association to promote the development of the IEEE 802.11n WLAN protocol
EWGGSMA Environmental Working Group
F-BCCHFast Broadcast Control Channel
F-SCHForward SCH (from BS)
f1AKA message authentication function used to compute MAC
f2AKA Message authentication function used to compute RES and XRES
f3AKA Key generating function used to compute CK. Compare with f8.
f4AKA Key generating function used to compute IK. Compare with f9
f5AKA Key generating function used to compute AK. It may simply generate 0 if concealment of SQN is not required.
f8AKA Ciphering Function. May be Kasumi. Uses CK, which is derived from RAND using f3
f9AKA Integrity Protection Function. May be Kasumi. Compare with f4
FAForeign Agent
FAC(1)FA Challenge
FAC(2)Final Assembly Code. The 2 digit IMEI ME manufacturer identity
FACCHFast Associated Control Channel
FAQFrequently Asked Questions
Fast FadingFade duration short relative to channel frame length
FBIUS Federal Bureau of Investigation
FCFeature Code. An asterisk followed by digits indicating the invocation of a feature (e.g. *73 may be used to disable call forwarding). Feature codes should be sent to the HLR for interpretation. There is no standardization of feature codes
FCCUS Federal Communications Commission
FCCHGSM Frequency Correction Channel; downlink only, correction of MS frequencies, transmission of frequency standard to MS etc.
FCIForward Call Indicator. Used to indicate whether a number portability query has occurred for this call (to prevent looping)
FCSFrame Check Sequence. A checksum for a transmitted frame
FDDFrequency Division Duplex
FDDIFiber Distributed Data Interface
FDMFrequency Division Multiplex. See FDMA
FDMAFrequency Division Multiple Access. Compare with TDMA and CDMA
FDNFixed Dialing Number
FEFunctional Entity. A logical element of a network. Not necessarily realized as a physically distinct device
FE-NTSFeature Enhanced NTS
FEC(1)Forward Error Correction
FEC(2)Forwarding Equivalence Class. An identity for packets that all get routed via MPLS in the same way
FERFrame Error Rate. The number of frames in error divided by the total. These frames are usually discarded, in which case this can be called the Frame Erasure Rate
FEXTFar End CrossTalk
FFGSMA Fraud Forum
FFPCCDMA Fast Forward Power Control
ffsFor Further Study
FFTFast Fourier Transform
FHMAFrequency Hopping Multiple Access
FHSSFrequency Hopping Spread Spectrum.
FIBForward Indicator Bit. Indicates the start of a retransmission cycle in MTP. See BIB
FIFOFirst in, first out. A queuing methodology similar to lining up for a bank teller. Compare with LIFO
FIPSUS Federal Information Processing Standards
FISUFill-In Signal Unit. The keep-alive message for SS7 MTP
FLEXA Motorola one-way paging protocol that runs at 1600, 3200 or 6400 bps. Compare with POCSAG
FM(1)Frequency Modulation
FOCCForward Control Channel. Used to send signaling messages from a base station to one or multiple mobiles
Foreign AgentIP node that receives packets from a Home Agent for delivery to a Mobile Node currently in its service area
FPLMTSFuture Public Land Mobile Telecommunications Systems. Now IMT-2000
FQDNFully Qualified DN. A domain name with enough information (including server name, if necessary, to determine a unique IP address). For example, if 'domain.com' had two servers, 'alpha' and 'beta', 'alpha.domain.com' would be fully-qualified, but 'domain.com' would not.
FRFull Rate (e.g. for a voice coder). Compare with HR
FRADFR Access Device
FSKFrequency Shift Keying
FSN(1)Forward Sequence Number. The sequence number of an MTP frame being transmitted. Contrast with BSN
FSN(2)Frame Sequence Number
FTAMFile Transfer, Access and Management
FTIFractional T1. A customer may lease a portion of a full T1
FTN(1)Forward-To Number
FTPInternet File Transfer Protocol
FTTCFiber to the curb
FTTHFiber to the home
FVCForward analog voice channel, transmitted by an MS
FWAFixed Wireless Access. See WLL
FWIFlash with Information; used to transmit data from an MS during a call
G.711The ITU-T standard for PCM encoding telephone audio on an 64 kbps channel. Because it operates at an8 kHz sampling rate (8 bits per sample) it can only encode frequencies between 0 and 4 kHz. There are two encoding variants. mu-law and A-law. A-law is used for international circuits and represents smaller signals with greater fidelity.
G3FAXGroup III Facsimile service
G95A sub-group of GGRF investigating roaming between GSM and CDMA systems based on TIA/EIA-95 and cdma2000
GADGeographic Area Description. GSM 101.109 and 3GPP 23.032 defines this. Related to CGL in ATIS T1.628
GAITGSM/TIA/EIA-41 Interoperability Trial
GALILEOA European positioning system based on 30 satellites and ground stations. Devices can position themselves based on accurate (atomic clock) time transmitted from the satellites and their knowledge of the satellite's positions. Similar to the US GPS
GAPSS7 ISUP Generic Address Parameter. Used in number portability to carry the LRN
Gateway MSCAn MSC designed to receive wireless calls from the PSTN
Gaussian NoiseNoise with constant power spectral density across the radio channel.
GBAGeneric Bootstrapping Architecture. Uses key material located in an HLR, HSS or AAA to 'bootstrap' a key for other purposes, e.g. mobile application security A security association is established by the BSF with both the UE and NAF allowing secure communication between the UE and the NAF, without the NAF having any root key material.
GbpsGiga-bps. A data speed of billions of bits per second. See Mbps and kbps
GCCGroup Call Control
GCCSGeneric Call Control service for Parlay/OSA
GCFGSM Global Certification Forum
GCRGroup Call Register
GDPISUP Generic Digits Parameter
GECOGlobal Emergency Call Origination. Allows a phone to make an emergency call in an area where the emergency digits are different than at home.
GEOGeostationary Orbit (for a satellite)
GETSUS Government Emergency Telecommunications Service
GFSKGaussian FSK
GGRFGSM Global Roaming Forum within the GSM Association. Composed of GAIT, G95 and groups considering interworking with iDEN and TETRA
GGSNGateway GSN. Connects to other packet data networks (e.g. internet). See SGSN
GHAGlobal Hexadecimal Address. See MEID.
GHOSTGSM Hosted Short Message Teleservice. Allows TIA/EIA-136 messages to be delivered to a GSM MS
GHzOne thousand million Hz. A measure of radio frequency
GIFGraphics Interface Format. A common graphics format suitable for computer-drawn graphics with few colors (up to 256). It supports simple animation. JPEG, PNG or TIFF are more suitable for photographs.
GigaPrefix to indicate one billion (e.g. Giga-bit). Abbreviated G. See Gbps
GIIGlobal Information Infrastructure
GISGeographic Information System. A system that combines mapping information with domain-specific information that can be queried by computers.
GIWUGSM Inter-Working Unit. An interface to various networks for data communications
Global challengeMethod of authentication using the same random number (RAND) for every mobile in a cellsite or sector
GLONASS(1)Russian satellite-based location system. Compatible with GPS
GMMGPRS Mobility Management Protocol
GMSKGaussian MSK
GMTGreenwich Mean Time. The reference point for time zones around the world.
GNSSGlobal Navigation Satellite System. A generic name for a satellite based positioning system. Examples are GPS, GLONASS, GALILEO and Beidou.
GoInterface between the GGSN and PDF that allows the application of policy (network rules) to bearer usage.
goodputSee throughput and badput
GPRSGeneral Packet Radio Service. A GSM-based packet data protocol using up to all 8 of the time slots in a GSM channel. It supports data rates up to 115 kbps, although 10-40 kbps is more likely in practice. Most terminals do not support usage of more than 1-3 timeslots. The difference with HSCSD is that the bandwidth can be shared amongst many users, making it more flexible, but also more susceptible to speed degradation due to overloading. See ADRC
GPSGlobal Positioning System. A system for determining location based on comparing signals from several US military satellites. Compare with AOA, TOA
GRTelecordia Generic Requirements document
GREGeneric Routing Encapsulation. See RFC 1701
GRIGPRS Roaming Exchange. Provides interconnection, routing, DNS, security and QoS functions
GSLGlobal Service Logic
GSMGlobal System for Mobile Communications
GSM-RA GSM-based PAMR system developed by European railways.
GSMAGSM Association
GSNGPRS support node. See SGSN, GGSN.
GSTNGeneral Switched Telephone Network. Synonym for PSTN
GTGlobal Title. A non-native SS7 address based on E.164 DNs, E.212 IMSI, etc.
GTAGT Address
GTAISS7 SCCP GT Address Indicator
GTPGPRS Tunneling Protocol
GTT(1)Global Title Translation. A method of routing in SS7 networks based on an GTs and not Point Code
GTT(2)Global Text Telephony
GUGGVNS User Group
GUIGraphical User Interface
GUPGeneric User Profile
GUTSGeneral UDP Transport Service
GVNSGlobal Virtual Network Service
H.245(1)A protocol used to control H.323 teleconferencing sessions.
H.248ITU-T protocol to control the MGW
H.323ITU-T recommendation for teleconferencing. See OpenH323
HAMIP Home Agent
HACHA Challenge
HANDMREQTIA/EIA-41 HandoffMeasurementRequest INVOKE message. Being replaced by HANDMREQ2
HANDMREQ2TIA/EIA-41 HandoffMeasurementRequest2 INVOKE message. Used by the Serving MSC to determine the signal strength being received by a neighboring Candidate MSC. Replaces HANDMREQ2
HandoffThe process of a MS changing from one frequency in one cell or sector to a different frequency in a neighboring cell or sector
HCHome Country
HCMHandset Configuration Management. See IOTA
HDB3High Density Bipoloar Order 3 Encoding
HDLCHigh Level Data Link Control
HDMLHandheld Markup Language
HDRHigh Data Rate. High speed data-only version of CDMA, standardized as EvDO. Now called HRPD
HDSLHigh bit rate DSL. Symmetric DSL used for corporate networking
HEHome Environment
HertzA unit of frequency. See MHz, GHz, kHz
HFC(1)HF Counter
HFC(2)Hybrid Fiber-Coax
HGHeader Generator
HIHandover Interface
HINFOHost Information
HIPPIHigh-Performance Parallel Interface
HLPIHigher Layer Protocol Identifier
HLRHome Location Register
HNIHome Network Identifier. The MCC and MNC prefix of a group of IMSI codes.
Home AddressAn IP address permanently assigned to a device that is supported by Mobile IP. Messages routed to this address will arrive at the HA.
Home AgentIP node that receives packets at a Mobile Nodes static address and forwards them to a Foreign Agent for delivery at its current ('care-of') address
Home MSCThe MSC to which the PSTN routes based on an MDN
HomeRFPromoters of the SWAP protocol for in-home wireless networking. This protocol was abandoned in 2003.
HPCHigh Probability of Completion
HRHalf Rate (e.g. for a voice coder). Compare with FR
HRFWGHomeRF WG. Note that this protocol was abandoned in 2003
HRLHeader Reduction Lower
HRPDcdma2000 High Rate Packet Data (formerly EvDO and HDR). It combines TDM on the forward link to provide from 38kbps to 2.5Mbps data rates. The reverse link supports speeds from 9.6kbps to 154kbps
HRUHeader Reduction Upper
HS-DSCHHSDPA DSCH. A high speed channel for transmitting data to a W-CDMA mobile.
HS-PDSCCHHSDPA DL control channel
HS-PDSCHHSDPA DL physical channel
HSCSDHigh Speed Circuit Switched Data. GSM enhanced to allow the concurrent use of up to four timeslots, providing a theoretical maximum 57.6 kbps data rates, although maximum rates of 28.8kbps to 43.2kbps are more realistic in practice. The main difference with GPRS is that the timeslots are assigned exclusively to one mobile for the duration of a data call.
HSDPA3GPP High Speed Downlink Packet Access. Provides higher data rates 'down' from the network to the mobile at about 1.5 Mbps in a 5 MHz carrier. Uplink speeds will be the same as EDGE - 384 kbps. See HSUPA and HSPA Evolution. See ADRC
HSGHeader Stripping and Generation
HSPA EvolutionAn evolution of HSDPA and HSUPA that is promising downlink speeds of 28 Mbps, uplink speeds of 11.5 Mbps in a 5 MHz carrier. See ADRC
HSS3GPP Home Subscriber Server. Similar to AAA
HSSIHigh Speed Serial Interface. A serial interface that can be used for very short distances (up to 50 feet), supporting speeds up to 52 Mbps
HSUPA3GPP High Speed Uplink Packet Access. Complements HSDPA by providing higher throughput on the W-CDMA link for uploading (MS to network). Rates for initial systems will be about 1 Mbps but eventually 5.76 Mbps is promised. The RTT is estimated as under 50 ms. See HSPA Evolution and ADRC
HTMLHypertext Markup Language
HTTPHypertext Transfer Protocol . See RFC 2068
httpsSecure HTTP
Hyperband HandoffHandoff between two different frequency bands (e.g. 800 MHz cellular and 1800 MHz PCS)
HzCycles per second. A measure of radio frequency
I-CSCFInterrogating CSCF. Main contact point for IMS connections to a carrier's subscribers
I-SCMInterrogating SCM
I-WLANWLAN Interworking with a 3GPP cellular network.
IA5International Alphabet 5. Basically the ASCII character set
IAMSS7 ISUP Initial Address Message. Used to initiate a call
IANAInternet Assigned Number Authority. Mostly superseded by ICANN
IAPIntercept Access Point. A point within the telecommunications network that provides voice or data for CALEA interception to a DF
IAPPInter-Access Point Protocol. An IEEE protocol to allow the secure transfer of MS context from one AP to another. It is based on IEEE 802.11f.
IBCIterated Block Ciphers
IC(1)see IXC
IC(2)Integrated Circuit
ICANNThe Internet Corporation for Assignment Names and Numbers. Performs top level resource assignment tasks for the internet, e.g. for domain names and IP addresses.
ICCIDAn identifier for a SIM or UIMLuhn checksum. The number always starts with the digits '89' (indicating a 'Telecommunications' card) followed by a 1-3 digit E.164 Country Code and 1-4 digit Issuer Identification Number. These first digits, which cannot number more than 7, are followed by the Individual Account Identification Number which is most likely to be 11 digits long. Administered according to ITU-T Recommendation E.118
ICMPInternet Control Message Protocol. Method for reporting errors and performing loopback testing on the internet
ICOIntermediate Circular Orbit
ICSImplementation Conformance Statement
IDBITS Data Bus (SAE J2366)
iDENIntegrated Digital Enhanced Network. Motorola's proprietary system for E-SMR, used by Nextel and others. Based on GSM
IDLInterface Description Language
IDSLISDN Digital Subscriber Line. Just a fancy name for ISDN
IEInformation Element
IEC(2)Internet Engineering Consortium
IEC(3)International ElectrotechnIcal Commission and the identity of standards produced by this organization.
IEEEInstitute of Electrical and Electronic Engineers
IEEE 802.15.1The IEEE Standard for Bluetooth
IEEE 802.15.4The IEEEStandard for ZigBee
IEEE-ISTOIEEE Industry Standards and Technology Organization
IESGInternet Engineering Steering Group. Group that oversees the activities of IETF
IETFInternet Engineering Task Force. Standards setting body for the Internet
IFInformation Flow
IFASTInternational Forum on AMPS Standards Technology. Allocates IRM and SID codes
IGPInterior Gateway Protocol. See MPLS
IGS(1)International GNSS Services. A voluntary federation of more than 200 worldwide agencies that pool resources and permanent GPS and GLONASS station data to generate higher precision data and products. It is likely that the new GNSS, GALILEO, will be included in the future.
IIFInterworking and Interoperability Function
IKIntegrity Key. Protects (via encryption) the contents of signaling messages. In AKA it is derived from RAND using f4. It is applied to messages using f9
IKEInternet Key Exchange Protocol
ILECIncumbent LEC. The former monopoly local telephone carrier. cf CLEC
ILMIncoming Label Map. See MPLS
IM(1)IP Multimedia. A network using IP to transport voice, signaling, text, video etc.
IM(2)Instant Messaging
IM-MGWIM Media Gateway Function
IMAP4Internet Message Access Protocol. IETF RFC 2060
IMCInternet Mail Consortium
IMDInter-Modulation Distortion. The interaction of two or more signals, producing an unwanted additional signal
IMEI56 bit GSM International Mobile Equipment Identity. Composed of TAC + FAC + SNR + spare digit. A check digit is also included, but not always transmitted. See also IMEISV and MEID
IMEISVIMEI with Software Version Number. Composed of TAC + FAC + SNR + SVN
IMGIInernational Mobile Group Identity
iModeJapanese (NTT DoCoMo) wireless internet access system. See cHTML
IMRNIP Multimedia Routing Number
IMSIP Multimedia Subsystem. An All-IP wireless system, where data, voice and signaling are all carried as IP packets.
IMSIInternational Mobile Subscriber Identity. Formerly called International Mobile Station Identity. Based on the ITU-T E.212 numbering plan. Composed of MCC MNC and MSIN. The only subscription identifier used by GSM and the future subscription identifier for CDMA.
IMSI_Mcdma2000 MIN-based IMSI.
IMSI_OOperational value of IMSI used by a cdma2000 MS. Either IMSI_M or IMSI_T
IMSI_O_SThe last 10 digits of IMSI_O. Used for compatibility with older CDMA systems that relied on the 10 digit MIN.
IMSI_TTrue IMSI used by cdma2000. Compare with IMSI_M. See IMSI_O
IMT-2000International Mobile Telecommunications for the year 2000 (or thereabouts)
IMTS-2000The ITU 3G initiative. It does not define specific protocols, but just the performance goals for them, such as bandwidth. Specifications are being developed by 3GPP and 3GPP2.
IMUIInternational Mobile User Identity
INIntelligent Network. Wireless equivalents are WIN and CAMEL
INAPIN AP. The IN messaging protocol
INCIndustry Numbering Committee (for the NANP)
INIIRM Network Identifier. The first four digits that uniquely identifies a carrier HLR
INMIntegrated Network Management
INNInternal Network Number
INS(1)Intertial Navigation System. A device that calculates position based on estimating its own movement relative to a starting position at a known location. Can be quite accurate in the short term, but gets continually less accurate until reset at a known location again.
IntegrityPreventing information (e.g. a data transmission) from being manipulated. This can be accomplished by putting a MAC on each message.
InterfaceA connection between two network elements. Compare with Protocol
InterleavingMixing of bits upon transmission according to a simple pattern (e.g. organizing bits in a matrix by columns and transmitting by rows) to somewhat randomize the output and protect from burst of noise on the RF channel
Intermodulation InterferenceRF interference within a channel generated as one or more intermodulation products within the receiver itself, typically as the result of the presence of very strong signals in adjacent bands. Contrast with Systemic Interference and Non-systemic Interference
IntservIntegrated Services
INVOKEMessage sent to initiate an TCAP transaction
IOSInter-Operability Standard. A version of the TIA/EIA-634 A-interface that enhances inter-vendor compatibility
IOTInter-Operator Tariff
IOTAIP-based Over-the-Air configuration management
IP(1)Intelligent Peripheral
IP(2)Internet Protocol
IP-MIP Multicast
IPCPPPP IP Control Protocol
IPDRInternet Protocol Detail Record. An internet oriented record for carrying charging details for services. Compare with CIBER, BAF, TAP, EMI
IPHCIP Header Compression. Provides compression (and decompression) of TCP, UDP and IP headers.
IPLMNInterrogating PLMN
IPRIntellectual Property Rights (e.g. patents). See DRM.
IPSECIP Security. Compare with SSL (for TCP). See IETF RFC 2401. Also spelled IPSec
IPv4IP Protocol Version 4. The version currently in use in the internet, using 32 bit addressing. See also IPv6.
IPv6IP Protocol Version 6. The version that is supposed to provide significantly larger and more powerful addressing, and eventually replace IPv4. Don't hold your breath
IPv6CPIPv6 Control Protocol
IR(1)Intelligent Roaming
IR(3)Initialization and Refresh Packet. RFC 3095
IRAInternational Reference Alphabet
IRDBIR Database. A database that can be loaded into a phone over the radio interface that prioritizes systems that may be detected by a phone based on carrier agreements
IREGGSMA International Roaming Experts Group.
IRGIFAST International Roaming Guide
IRIIntercept (i.e. LAES) Related Information
IRMInternational Roaming MIN. A mobile subscription identifier beginning with the digit 0 or 1 to avoid conflict with NANP MINs
IRPIntegration Reference Point
IRSInternet Reachability Service
ISTIA Interim Standard
IS-124Wireless call detail and billing record format for online transfer
IS-136Second generation TDMA air interface standard
IS-2000cdma2000 air interface standard. A successor to TIA/EIA-95-B
IS-41Wireless intersystems operation standard. Now called TIA/EIA-41
IS-41-CIS-41 Revision C (Intersystem Operations Standard)
IS-54First generation TDMA Radio Interface standard
IS-634See TIA/EIA-634
IS-637CDMA short message service standard
IS-683see TIA/EIA-683
IS-756A TIA standard for WNP
IS-801TIA/EIA interim standard for CDMA MS-assisted position determination
IS-91Most advanced analog air interface standard (including NAMPS)
IS-93Wireless-PSTN interface standard
IS-95cdmaOne CDMA air interface standard
ISAKMPInternet Security Association and Key Management Protocol
ISCInternational Switching Centre
ISDNIntegrated Services Digital Network. PSTN utilizing SS7 interfaces
ISIInter-Symbol Interference
ISISIntermediate System - Intermediate System IP routing algorithm.
ISMIndustrial, Scientific, Medical frequency band (2.45-2.5 GHz). Available around the world for unlicensed applications, generally using low power and short distances
ISMAInterference Sense Multiple Access
ISOInternational Organization for Standardization
ISO-8859-1The most common 8-bit character set used for web pages. An ISO/IECstandard. Also see UNICODE
isotropicRadiating equally in all three dimensions (as opposed to directional, with energy being focussed more in some directions than other).
ISPInternet Service Provider
ISUPISDN User Part. SS7 signaling between switches. Standardized in ANSI T1.113 and ITU-T Q.760-769
ITARUS International Traffic in Arms Regulations. These rules used to govern export of encryption technology in the US and, to some extent, in Canada. Replaced by EAR
ITNIndividual Telephone Number Pooling. Phone numbers can be assigned to carriers one at a time, instead of in blocks of 1,000 or 10,000
ITOT(1)ISO Transport Service on top of TCP. Emulates the services of ISO protocols such as COTP but with TCP as the actual transport protocol. See RFC 2126.
ITS(1)Intelligent Transportation System ("Smart Highways")
ITS(2)IP Transport Subsystem
ITUInternational Telecommunications Union
ITU-RITU - Radio Communications Division
ITU-TITU - Telecommunications Division
IuInterface between an RNC and CN (MSC, SGSN or CBC). Support for this within GSM has been suggested, but is unlikely. See also Iub, Iur.
IUAISDN Q.921 User Adaptation Layer
IubA 3GPP interface between an RNC and a Node B. See Iu, Iur.
IurA 3GPP interface between two RNCs. This is a logical interface, and the RNCs may not be connected by point-to-point physical links. See Iu, Iub.
IVInitialization Vector. A 24-bit session-specific key for WEP
IVRInteractive Voice Response
IWFInter-working Function. Used for wireless data interworking between digital mode data and analog (e.g. modems)
IXCInter-eXchange Carrier. A carrier licensed to provide long distance services
J-STD-Joint ATIS-T1/TIA standard
J-STD-025LAES standard jointly produced by ATIS T1 and TIA TR-45
J-STD-034Wireless E911 Phase I standard (cellsite and mobile identification, callback capabilities). See J-STD-036
J-STD-036Wireless E911 Phase II standard (position of caller within 125m/400ft). See J-STD-034
J2EEJava 2 Enterprise Edition
J2MEJava 2 Micro Edition
JAINJava APIs for Intelligent Networks
JavaA C-like programming language that is compiled into a virtual machine language providing efficiency close to that of languages compiled into native machine code while providing portability of the compiled program. Each computer system that wants to run Java has to provide a virtual machine
JCPJava Community Process
JDCJapanese Digital Cellular
JFIFJPEG File Interchange Format
JIPISUP Jurisdiction Information Parameter
JPEGJoint Photographic Experts Group. Not usually used to refer to the group, but a graphics format created for them that is suitable for digital photographs and similar images. It supports 24 bit color as well as variable levels of compression and quality. It should be referred to as JFIF, but isn't. cf GIF, PNG, TIFF
JSRJava Specification Request
JSR 177JSR for Security and Trust services API for J2ME
JTCJoint Technical Committee (e.g. with members of more than one SDO)
KasumiA block cipher used by AKA for the A5/3, f8 and f9 algorithms. See the wikipedia entry for more details
kbpskilo-bps. A data speed of billions of bits per second. See Mbps and Gbps
KcGSM cipher key. Used for voice encryption
KDFKey Derivation Function
KGKey Generator
kHzkilo-Hertz. Thousands of cycles per second. See MHz and GHz
KiGSM subscriber authentication key
kiloPrefix to indicate one thousand (e.g. kilo-bit). Abbreviated k. See kbps
KSGKeystream Generators
KSIKey Set Identifier
KSSKey Stream Segment
L1Layer 2
L2Layer 2
L2TPLayer 2 Tunnel Protocol. Defined in RFC 2661. Successor to PPTP. IP packets are wrapped in a layer containing another set of IP addresses and possibly also control messages. The detailed format varies depending on whether the transport protocol is IP, UDP or another PSN type.
L3Layer 3
LAC(1)Link Access Control
LAC(2)Location Area Code. 16 bit number identifiying a location area (i.e. group of base stations) within a GSM PLMN
LAESLawfully Authorized Electronic Surveillance. See CALEA, J-STD-025, surveillance
LAIGSM Location Area Identity. Composed of MCC + MNC + LAC
LAKLocal Authentication Key
LANLocal Area Network. Compare with WAN, MAN.
LAPLink Access Protocol
LAPBLink Access Protocol, Balanced
LAPDLink Access Protocol for the ISDN D Channel
LATALocal Access and Transport Area. US local telephone service area
LBLetter Ballot
LBALocation Based Application
LBCLast Batch Count. Exchanged by CIBER billing clearinghouses to ensure they do not get out of sequence with each other.
LBSLocation Based Services
LCPLink Control Protocol. A subset of PPP that is used to negotiate and establish link capabilities, including authentication
LCSLocation Services. This usually implies positioning of an MS for commercial services, not emergency services
LDAPLightweight Directory Access Protocol. See IETF RFC 3377. Compare with X.500 DAP
LDPLabel Distribution Protocol. See MPLS
LDTLocation Determination Technology
LEALaw Enforcement Agency
LeakageInability to bill for a service
LEAPLighweight EAP. A Cisco proprietary version.
LECLocal Exchange Carrier (wireline carrier for local calls). Also see ILEC and CLEC
LEMFLaw Enforcement Monitoring Facility (for LAES)
LEOLow Earth Orbit
LERLabel Edge Router. See MPLS
LERGLocal Exchange Routing Guide. Includes a list of valid number blocks in the NANP
LFBLookahead For Busy
LIDBLine Information DataBase. Used for validating collect calls, 3rd party calls, etc.
LIFLocation Interoperability Forum within OMA
LIFOLast in, first out. A queuing methodology similar to stacking dishes and using the dish on the top of the stack. Compare with FIFO
LIRLocation Identification Restriction. Prevents the location of a mobile phone from being revealed (with legal exceptions for E911, etc.)
LLA-RHOCLink Layer Assisted ROHC
LMDSLocal Multipoint Distribution Service. Uses the 27.5-31.3 GHz frequency band to serve mulitple points within a radius of 3-5km. Most carriers in this space have abandoned it or gone bankrupt. See MMDS.
LMMLocalized Mobility Management to improve local handover performance in Mobile IP
LMRLand Mobile Radio
LMSDLegacy MS Domain. Refers to existing SS7-based telecommunications systems, when accessed from an All-IP system. See MMD
LMSILocal Mobile Station Identity. See TMSI
LMUGSM Location Measurement Unit
LNDLast Number Dialed
LNPLocal Number Portability. Allows consumers to keep a phone number (MDN) when changing carriers within the same geographical region
LNPWGLocal Number Portability Working Group of NANC
LORAN(1)Long Range Aid to Navigation. A land based navigation system based on the difference in time between signals received from several transmitters at known locations.
LOSLine of Sight. A direct path through the air from transmitter to receiver. Always desirable for wireless communications, although not always necessary (e.g. for cellular/PCS)
LPCLinear Predictive Coding
LPDULink Protocol Data Unit. A frame
LRFLocation Registration Function. See WIN
LRNLocation Routing Number. A routing number that identifies the terminating switch for a Ported DN
LSBLeast Significant Bit or Byte. Compare with MSB
LSMSLocal Service Management System. Telephone carrier interface that downloads information from the NPAC into one or more NPDBs
LSPLabel Switched Path. See MPLS
LSPIProposed SS7 ISUP Local Service Provider Identification
LSRLabel Switching Router. See MPLS
LSSULink Status Signal Unit. The link status message for SS7 MTP
LTLine Termination
LTEA GSM competitor to EvDO Revision C promising similar data rates. See ADRC
LUDTLong UDT. Supports messages up to 3 kilobytes in length
M2MMachine To Machine. Communications between unattended machines. Most electronic communications is between machines but in many cases, such as a cellphone or PC, this is usually only because a person is using the device. An example of an M2M scenario is when a heat or alarm sensor communicates with a central computer, perhaps with the central computer providing feedback to other devices to shut off a malfunctioning machine, turn on fans or other automated control
M2PASS7 MTP2 Peer-to-Peer User Adaptation Layer
M2UASS7 MTP2 User Adaptation Layer
M3UASS7 MTP3 User Adaptation Layer. Resides above SCTP and below SCCP in an IP telecom signaling protocol stack.
MAALManagement ATM Adaptation Layer. Maps management requests from system management to SAAL. See ATIS T1.652
MABELMajor Account Billing Exchange Logistical Record. Defined by Cibernet to facilitate centralized billing for large account customers
MAC(1)Medium Access Control
MAC(2)Message Authentication Code. In AKA, a value derived from SQN, RAND and AMF using f1 that shows that the sender was in possession of certain secret information (i.e. is authentic).
MACAMobile Assisted Channel Allocation. Mobile determines the best alternate cellsite to originate a call in, when no channels are available in the current site
MAHMobile Access Hunting. Termination to one of a group of mobiles
MAHOMobile Assisted Handoff. Mobile measures signal strength at neighoring base stations to determine which to handoff to
MANMetropolitan Area Network. Compare with LAN, WAN
MANETMobile ad hoc Network. A collection of wireless nodes that can dynamically form a network without any fixed network infrastructure.
MAPMobile AP. Protocol that interconnects wireless telephone systems. See GSM and TIA/EIA-41
MBIMIN Block Identifier. The first 6 digits (usually) of a North American MIN, when assigned separately from the MDN. The first digit is always 2-9 (inclusive). Digits 0 and 1 are reserved for IRM codes.
MBMSUTRA Multimedia Broadcast and Multimedia Service
MbpsMega-bps. A data speed of millions of bits per second. See Gbps and kbps
MC(1)Short Message Center
MCCE.212 Mobile Country Code. First 3 digits of IMSI
MCFTPMulti-Channel Flow Treatment Protocol
MCIMalicious Call Identification
MCLMinimum Coupling Loss. The minimum loss required between a transmitter and a nearby receiver to avoid adversely affecting receiver performance.
McpsMillion Chips-per-second. See CDMA and W-CDMA
MCSEMicrosoft Certified Systems Engineer
MD-ISMobile Data - Intermediate System. A CDPD term
MD5Message Digest 5. A secure hashing algorithm. See SHA-1
MDNMobile DN
MDSMulti-Point Distribution System.
MEMobile Equipment. Synonym for UE. Contrast with MS
MEAMessage Encryption Algorithm
MegaPrefix to indicate one million (e.g. Mega-bit). Abbreviated M. See Mbps
MEGACOMedia Gateway Control - IETF Working Group
MEIMobility Event Indicator
MEIDA 56 bit Mobile Equipment Identity for CDMA and TDMA MS. Similar to the GSM IMEI, but allowing hexadecimal digits, and with a simplified structure (2 digit region code, 6 digit manufacturer code, 6 digit serial number). ESN and MEID are assigned by the TIA in their role as GHA.
MEMSMicro-Eletronic Mechanical System
MESAMobility for Emergency Service Applications. A joint ETSI/TIA project to increase the interoperability of emergency service communications.
meshA form of networking where access to a server can be accomplished by routing through other clients that are physically closer
meta-languageA language that can be used to define other languages. See ASN.1 and BNF
MExE3GPP TSG-T Mobile Execution Environment
MF(1)Multi-frequency tone signaling. Used for trunk signaling
MF(2)UIM Master File. Compare with EF and DF
MGMedia Gateway
MGCMG Controller
MGCFMG Control Function
MGCPMG Control Protocol. A VoIP call control standard. Also see older protocol SGCP
MGWMedia Gateway. Interface between packet environment of the CN and circuit environment of PSTN
MHzMillion Hz. A measure of radio frequency
MIBManagement Information (Data)Bases
MIHMedia Independent Handover. An IEEE 802.11 term indicating handover between 802.11, 802.3 or 802.16 and another radio interface.
MIHFMIH Function. A cross-layer entity, defined by IEEE 802.21, that provides mobility support through SAPs offering Event, Information and Command services.
MIMEMultipurpose Internet Mail Extensions
MIMOMultiple Input, Multiple Output antennas. This increases throughput and reduces bit error rates compared to traditional antenna systems which transmit and receive through a single antenna.
MINMobile Identification Number. 10 digit identifier of a mobile subscription. IRM for cdma2000, TDMA, AMPS. A MIN intended for use outside North America is usually an IRM assigned by IFAST
MIN1The last 7 digits of a MIN encoded in a wierd, but compact, 24 bit binary format
MIN2The first 3 digits of a MIN encoded in a very wierd, but compact, 10 bit binary format
minimizationRemoval of information that has been collected, but that is outside the scope of a court order. See LAES
MIPMobile IP. IETF RFC 2002
MIPSMillion Instructions per Second. Measurement of processor speed
MISPMobile Internet Service Provider
MLCOMA/3GPP Mobile Location Center
MLPMobile Location Protocol. An XML-based protocol developed by the OMA LIF group.
MLPPMulti-Level Precedence and Pre-emption
MLTSMulti-line Telephone System
MM(1)Mobility Management
MM(2)Multimedia Message
MM1MMS interface between UA and MMS Relay/Server
MM2MMS interface between MMS Relay and MMS Server
MM3MMS interface between MMS Relay/Server and External Servers for fax, email etc.
MM4MMS interface between two MMS Relay/Servers
MM5MMS interface between MMS Relay/Server and HLR
MM6MMS interface between MMS Relay/Server and user databases
MM7MMS interface between MMS Relay/Server and VAS applications
MM8MMS interface between MMS Relay/Server and billing systems
MMDMulti-Media Domain. An IP-based signaling system supporting voice, video, graphics, sound and application data, such as email in an integrated fashion. Contrast with LMSD. See IMS
MMDSMulti-channel Multi-Point Distribution Service. Uses the 2.1-2.7 GHz frequency band. The success of this technology has been about as poor as its cousin, LMDS.
MMIMan-Machine Interface
MMLMan-Machine Language. A human-readable language devised for communications between a human and a computer. Examples of formal languages in telecommunications are ITU-T Z.300 and the related TL1. These languages are textual and most humans are unlikely to want to use them directly, so they are more likely to take the place of a human-readable (i.e. ASCII character) protocol, with a GUI for the human to view and control the interactions with the computer more effectively and pleasantly.
MMSMM Service (e.g. text, audio, graphics)
MMSEMultimedia Messaging Service Environment
MMSNAMMS Network Architecture
MMTAMultiMedia Telecommunications Association. A subsidiary of TIA
MNMobile Node. An internet term for a mobile device capable of IP communications. See Mobile IP
MN-FAMN Foreign Authentication. An extension to MIP that provides stronger authentication. See IETF RFC 3012
MNCE.212 Mobile Network Code (identifies an individual carrier, or a portion of a carrier network). Part of IMSI
MNICMobile Network Identification Code
MNIDMN Identification
MNOMobile Network Operator. A carrier.
MNPMobile Number Portability. See LNP, WNP
MOMobile Originated/Originating
Mobile IPA set of protocols that allows a MN to roam on the internet. Not widely implemented.
Mobile NodeAn IP network node that has both a static address and a 'care-of' address associated with it. IP packets can be routed to it via a Home Agent (at its static address) and a Foreign Agent (at its care-of address)
MobilityThe capability of a device to initiate or receive services in many different systems, and to maintain session while travelling between systems.
MobitexAn Ericsson Wireless Data protocol, once known as RAM Mobile Data in the US.
MOSMean Opinion Score. A method of measuring quality (e.g. of wireless voice transmission) by asking people to rank their opinion on a numeric scale, and then averaging the results. Sophisticated, huh!
MoU(1)GSM Memorandum of Understanding. The guidelines under which GSM systems are implemented
MoU(2)Minutes of Use. A common measure of the usage of a group of subscribers
MPCMobile Positioning Center. Interfaces between MSC, PDE, CRDB and ESME
MPC-MLQ(1)Multipulse LPC with Maximum Likelihood Quantization audio codec used in G.723.1. Operates at a bit rate of 6.3 kbps
MPCAPMobility Positioning Capabilities
MPEGMotion Pictures Experts Group. Not usually used to refer to a group but a format for audio/video compression (and, obviously, decompression)
MPLSMulti Protocol Label Switching. An IP protocol (RFC 3031) designed to provide preferred treatment to priority traffic to achieve a higher QoS. Every packet labeled with the same FEC gets the same treatment
MPSMinimum Performance Standards/Specification.
MRFMedia Resource Function. Provides conference bridges, announcements, tones and so forth to IP-based telephony networks. See MRFC and MRFP
MRFCMRF Controller
MRFPMRF Processor. Provides tones, recordings, conference bridges etc.
MRPMarket Representation Partner. A participant in the 3GPP or 3GPP2 process that represents the marketing of technology in a region, such as 3G Americas for 3GPP or CDG for 3GPP2.
MS(1)Mobile Station (wireless phone)
ms(2)Milliseconds. Thousandths of a second. Also msec
MS-SMESME embedded in MS
MSAMetropolitan Statistical Area. CGSA for urban cellular systems. Also used for licensing the FCC AWS D band.
MSAGMaster Street Address Guide. A database of street names and house number ranges that define ESZ and their associated ESNs to enable proper routing of 911 calls. See E911.
MSBMost Significant Bit or Byte. Compare with LSB
MSCMobile Switching Centre
MSC-GSee Gateway MSC
MSC-OSee Originating MSC
MSC-SServing MSC
MSC-VVisited MSC. The MSC which a mobile is currently registered in
MSCINMSC Identification Number
msecMilliseconds. See ms
MSEIAMS Emergency Information Assistance
MSIDMobile Station Identifier. A MIN or an IMSI. See IMSI_O
MSINMobile Subscriber Identity Number. Unique number assigned to a subscriber as part of IMSI
MSISDNMS ISDN number. Same as MDN
MSKMinimum Shift Keying. FSK where peak-to-peak FM deviation is half the data rate
MSOCDMA Markov Service Option
MSPMultiple Subscriber Profile
MSRNMobile Station Roaming Number. The GSM equivalent of the ANSI-41 TLDN
MSS(1)Mobile Satellite System/Service
MSS(3)Multimedia Streaming Service
MSUMessage Signal Unit. The payload message for SS7 MTP
MTMobile Terminated/Termination/Terminal. The UE is composed of the MT and SIM/USIM and possibly other peripherals
MTA(1)Major Trading Area
MTA(2)Mail Transfer Agent
MTEMonths to Exhaust. The time at which a numbering resource (e.g. area code) is expected to be fully utilized
MTPMessage Transfer Part (SS7 transport layer)
MTP2MTP Layer 2
MTP3MTP Layer 3
MTSOOlder term for MSC
MTTRMean Time to Restore (after failure)
MTUMessage Transfer Unit
MultipathA radio link between the transmitter and receiver comprised of multiple paths which include intermediate reflections from various surfaces, usually due to non-line of sight communication paths
MVNEMobile Virtual Network Enabler. Provides infrastructure and services such as billing, subscriber management and operations support to MVNOs.
MVNOMobile Virtual Network Operator. A company that markets cellular service but contracts with facilities-based cellular carriers to actually provide the coverage
MWIFMobile WIreless Internet Forum. Promotes the use of a single All-IP network for future wireless systems (e.g. convergence of 3GPP and 3GPP2 protocols)
MWNMessage Waiting Notification (e.g. stutter dial tone or an indication on a wireless phone's display)
MWNEManaged Wireless Network Entity. A piece of equipment that provides OA&M data
MXMail Exchange (internet mail server)
N-1 SwitchThe switch responsible for LNP queries
NAANetwork Access Application
NACKNegative ACK
NAFNetwork Application Function of GBA.
NAINetwork Access Identifier. This is an email-like address format used to identify a AAA or a device with an interface to one.
NAMNumber Assignment Module. A portion of a mobile phone that stores a single user profile, including MIN and IMSI, but not ESN
NAMPSNarrowband AMPS
NANCNorth American Numbering Council. The organization responsible for overseeing the distribution of telephone numbers in the NANP
NANPNorth American Numbering Plan
NANPANorth American Numbering Plan Administrator (or Area)
NAPTRNumber Authority Pointer. See IETF RFC 2915.
NAS(1)Network Access Servers
NAS(2)Non-Access Stratum. Protocols between the UE and the core network that are transparent to the RAN (e.g. SMS)
NATNetwork Address Translation. Maps an internal set of IP addresses to an external set (perhaps assigned dynamically by DHCP)
NBAPNode B Application Part
NCASNon-Call Associated Signaling. Compare with CAS
NCGNetwork Capability Gateway. Obsolete. See OSA-SCS
NCGWSynonym for NCG. Obsolete. See OSA-SCS
NCSNational Communication System. Responsible for US Government communications, including WPS and GETS
NDCE.164 National Destination Code
NDSNetwork Domain Security
NENetwork Entity
NEBSNetwork Equipment Building Systems
NEMA-0183(1)Electrical interface for communications between maritime electronic devices. This includes some GPS data.
Net AdditionsIncrease in new revenue-generating subscribers over a time period (usually a quarter year)
NFCCNetwork Firewall Configuration and Control
NFSNumber Field Sieve. Used in cryptography
NGNNext Generation Network. ITU-T term for future wireless systems with even higher speed data capabilities.
NHLFENext Hop Label Forwarding Entry. See MPLS
NHPNo-Header Packet. See RFC 3242
NI(1)Network Identity
NI(2)Number Incomplete
nibbleFour bit
NIDNetwork Identification. A number that uniquely identifies a portion of a wireless carrier's total system. Used by TIA/EIA-95 (CDMA) systems
NIDSNetwork-Initiated Data Session
NIIFNetwork Interconnection Interoperability Forum
NISTUS National Insitute of Standards and Technology
NLNeighbour List
NMRNetwork Measurement Results
NMSINational Mobile Subscription Identity. MNC + MSIN
NMTNordic Mobile Telephone. An analog cellular system available either in the 450 MHz or 900 MHz bands
Node BLogical node in the 3GPP RNS responsible for radio transmission/reception in one or more cells to and from the UE. Terminates the Iub interface towards the RNC.
Non-repudiationEnsuring that a communication cannot be disavowed later
Non-systemic InterferenceRF interference within a channel used in a wireless system that emanates from a transmitter that is not part of the same system, and that may have undefined channel characteristics. This is of greatest concern for systems operating in unlicensed bands, such as ISM. Compare with Systemic Interference
nonceA number that is used only once. Often used in cryptography
NPNumber Portability
NPANANP Numbering Plan Area (i.e. area code)
NPACNP Administration Center. Often used to refer to the NPAC SMS
NPDBNumber Portability Database. A list of ported numbers and associated LRNs used for LNP routing
NPDUNetwork Protocol Data Unit. A packet
NPINumbering Plan Identifier
NPMNon-Public Mode Service
NPRMFCC Notice of Proposed Rulemaking
NRMNetwork Reference Model (e.g. TIA/EIA/TSB-100)
NRNNetwork Routing Number
NRTLNationally Recognized Test Lab
NSAuthoritative Name Server for a Domain. Converts between a domain name (e.g. cnp-wireless.com) and an IP address and related information
NS/EPUS National Security and Emergency Preparedness. See WPS
NSAUS National Security Agency. Keeps a tight grip on exports of US encryption technology
NSDPB&SNon-signaling Data Protocol for Billing and Settlement. subset of IS-124
NSDPFNon-signaling Data Protocol for Fraud. A subset of IS-124
NSDUNetwork Service Data Unit
NSEPNational Security and Emergency Preparedness. People who are eligible for PAS/PACA
NSNNational Significant Number. All of an E.164 number apart from the CC, i.e. NDC + SN
NSSNetwork and Switching Subsystem
NSTACUS National Security Telecommunications Advisory Council
NTNetwork Termination
NTIAU.S. Dept. of Commerce National Telecommunications and Information Administration
NTSNumber Translation Service
Number PoolingSharing a block of numbers between carriers. In the NANP this means that a block of 10,000 numbers is shared (currently in multiples of 1,000) by several carriers. Pooling is implemented using LNP
Number PortingSee LNP or WNP
NVSENormal Vendor Specific Extension
NXXDigits 4-6 of a NANP directory number. N can be any digit 2-8, while X can be any digit 0-9
O-BCSMOriginating BCSM
O&MOperations and Maintenance
OA&MOperations, Administration and Maintenance
OAAOver-the-Air Activation. See OTA
OAM&POperations, Administration, Maintenance and Provisioning
OATSOver-the-Air Activation Teleservice. See TIA/EIA-136
OBFOrdering and Billing Forum of ATIS
OC-1SONET service at 51.84 Mbps. Equivalent to one DS3 (672 DS0)
OC-12SONET service at 622.08 Mbps. Equivalent to 12 DS3 or 8,064 DS0
OC-18SONET service at 933.12 Mbps. Equivalent to 18 DS3 or 12,096 DS0
OC-192SONET service at 9.95328 Gbps. Equivalent to 192 DS3 or 129,024 DS0
OC-24SONET service at 1.24416 Gbps. Equivalent to 24 DS3 or 16,128 DS0
OC-3SONET service at 155.52 Mbps. Equivalent to 3 DS3 or 2,016 DS0
OC-36SONET service at 1.86624 Gbps. Equivalent to 36 DS3 or 24,192 DS0
OC-48SONET service at 2.48832 Gbps. Equivalent to 48 DS3 or 32,256 DS0
OC-768SONET service at 38.813 Gbps. Equivalent to 768 DS3
OC-9SONET service at 466.56 Mbps. Equivalent to 9 DS3 or 6,048 DS0
OC-96SONET service at 4.97664 Gbps. Equivalent to 96 DS3 or 64,512 DS0
OCDMOptical Code Division Multiplexing
OCHOptical Channel
OCNOperating Company Number. US identifier for a telecom carrier
OCSOnline Charging System. Used for real-time charging (e.g. prepaid).
OCSPOnline Certificate Status Protocol. An IETF protocol
octetA snooty standards term for byte
ODBOperator Determined Barring
OETUS FCC Office of Engineering & Technology
OFAOptical Fiber Gateway
OFDMAOrthogonal FDMA
OGOptical Gateway
OHGOperators Harmonization Group. A group of wireless carriers that wants to make CDMA systems work on both ANSI-41 and GSM networks
OLAOptical Line Amplifier
OLCOverload Control
OLIOriginating Line Indicator. ISUP parameter that identifies the class of phone (e.g. residential, payphone, hotel/motel)
OLNSOriginating Line Number Screening (using LIDB)
OLTOptical Line Termination
OMAOpen Mobile Alliance
OMCOperations and Maintenance Center
OMNCSOffice of the Manager, NCS
OMTOverhead Message Train (messages transmitted from base station on the analog Control Channel)
ONOptical Network
OPCOriginating Point Code. Where an SS7 message came from
OPDUOperation PDU
OpenH323A project to create an open source implementation of H.323
OPSPOrigination Participation Service Provider
OPTSOver-the-Air Programming Teleservice. See TIA/EIA-136
Originating MSCThe first MSC involved in a mobile terminated call. Either a Gateway MSC or the Home MSC
OriginationThe process of starting a call, usually initiated by dialing digits
ORREQTIA/EIA-41 OriginationRequest transaction
OSA3GPP Open Service Access. Enables third parties to use network functionality through an open standardized interface (OSA API)
OSA-ASOSA Application Server
OSA-SCSOSA Control Server
OSFOperations Systems Function
OSIFrench synonym for ISO
OSPFOpen Shortest Path First IP routing algorithm.
OSS(1)Operations Support Subsystem
OSS(2)Operator Services Switch
OTAOver-the-Air programming. Uploads internal mobile tables or software.
OTAFOver-The-Air Activation Function. A specialized MC for performing OTASP and OTAPA
OTAPAOver-The-Air Parameter Administration. A network initiated form of OTA
OTASPOver-the-Air Service Provisioning. A mobile-initiated form of OTA
overdialThe process of dialing a phone number during an established call, when the original number dialed was to access some kind of gateway system. See Roamer Port
OWFOne Way Function. A function that is much easier to perform than to invert (i.e. back-calculate). This concept is the foundation of much of modern cryptography
OXCOptical Cross Connect
P-CSCFProxy CSCF. First contact point for a terminal within the IMS
P-PPDSN to PDSN interface used to support fast handoff (tunneling of packets from old serving system to new serving system).
PACPPTP Access Concentrator. Concentrates PPP traffic on a dial access platform. See PNS
PACAPriority Access and Channel Assignment. Channels are assigned to mobiles attempting to originate a call in order of priority, rather than first-come, first-served. See PAS
Packet dataData transmitted from multiple users in individually address discrete packets. Compare with CSD
PACSPersonal Access Communications System
PADPacket Assembly/Disassembly
PageThe process of telling an MS to prepare for an incoming call
PAMRPublic Access Mobile Radio. A wide-area form of PMR that provides group-oriented communications (such as PTT) to the public, rather than being run for a single organization. See SMR.
PANPersonal Area Network. A network that connects personal devices, such as computer, keyboard, mouse, phone and monitor. Also known as Piconet
PAPPassword Authentication Protocol. A simple authentication protocol that sends security information in the clear. Compare with CHAP
Parlay/OSAOpen Service Access/Architecture. An API that enables operator and 3rd party applications to make use of network functionality through a set of open, standardised interfaces. Implementations are JAIN SPA, OMG-IDL and WSDL
PASPriority Access Service. See PACA
PBCCHGPRS Packet Broadcast CCH
PBXPrivate Branch Exchange. A privately owned switch providing wired and possibly also wireless service for an office, factory, campus, etc.
PCPersonal Computer
PCAPUTRAN Positioning Calculation Application Part
PCCCHGPRS Packet Control Channel
PCFPacket Control Function. Obsolete. See PDF
PCG3GPP Project Coordination Group
PCHPaging Channel
PCIProtocol Capability Indicator
PCIAPersonal Communications Industry Association. Rival trade association to CTIA
PCMPulse Code Modulation. The encoding scheme for digital voice in a circuit-switched telephone network.
PCMCIAPersonal Computer Memory Card International Association
PCNPersonal Communications Network. See PCS
PCSPersonal Communications System. See DCS, PCS1900
PCS1900North American PCS frequencies, 1850-1990 MHz. See DCS
PCSCPersonal Communications Switching Center. See MSC
PDPacket data
PDAPersonal Digital Assistant
PDCPacific Digital Cellular. A Japanese cellular standard based on GSM operating in the 800 MHz and 1500 MHz frequency bands.
PDC-PPDC Packet network used
PDCPUTRA Packet Data Convergence Protocol
PDDPost-Dial Delay. The delay between dialing and having the call cut through to the party at the other end
PDEPosition Determining Entity
PDFPolicy Decision Function
PDGPD Gateway. Similar to PDSN.
PDHPlesiochhronous Digital Hierarchy
PDLPPD link protocol
PDNPublic Data Network or Packet Data Network
PDPPD Protocol
PDREGPower-Down Registration
PDSNPacket Data Serving Node. Not to be confused with PSDN
PDUProtocol Data Unit
PEAPProtected EAP. A more secure version of LEAP developed by Microsoft and Cisco.
pen registerA form of surveillance where dialed digits and time of call are collected
PenetrationThe percentage of the population of a service area (POP) that have acquired a certain service
PER(1)Packed Encoding Rules. Avoids the TLV overhead of BER and TCAP
PER(2)Packet Error Rate. The fraction of packets that have one or more errors. Compare with BER.
pESNPseudo ESN. Formed from the 8-bit prefix 0x80 followed by the 24 least significant bits of the SHA-1 extract of the MEID. See also tESN and pUIMID.
PetaPrefix to indicate one thousand trillion (e.g. Peta-bit). Abbreviated P
PHPacket Handler
PHBPer-Hop Behaviour
PHSPersonal Handyphone Service. A real success until people found that it was not true cellular service
PIPolling Indicator
PIC(1)Preferred Inter-exchange Carrier Code. Identifies the long distance carrier for a subscriber. Generally national in scope
PIC(2)Point in Call. An IN, WIN, CAMEL term
PiconetSee PAN
PINPersonal Identification Number. Used to restrict access to personal services or capabilities
PINTPSTN and Internet Interworking - IETF WG. See RFC 2848
PISNPrivate Integrated Services Network. Composed of inter-connected PBXs.
PKCPublic Key Cryptography. Also known as Asymmetric Key Cryptography
PKEPublic Key Encryption
PKIPublic Key Infrastructure
PLPhysical Layer
PlaintextUnencrypted data. Compare with Ciphertext
PLCMUsed for encoding cdma2000 conversations on the reverse traffic channel. Originally based on the ESN of an MS it now can be assigned by the BS or calculated from the IMSI or MEID.
PLMNPublic Land Mobile Network. A cellular, PCS or 3G wireless network
PM(1)Privacy Mode
PM(2)Personal Mobility
PMNPublic Mobile Network. Synonym for PLMN
PMRProfessional/Private Mobile Radio. A radio system established to service a single organization or group of related organizations. They usually provide special group communications capabilities, such as PTT. See SMR. Contrast with PAMR
PN(1)Pseudo-Noise. Orthogonal code used to separate CDMA transmissions
PN(2)Project number
PN SequenceA defined repetitive sequence of binary bits, typically quite long. PN sequences are often used to test digital communications systems because they are composed of typical data patterns (as opposed to, say, alternating 1s and 0s) but are nonetheless defined bit-by-bit, so that the correctness of received bits can be determined at the receiver. PN sequences are also used extensively in the channel structure of many wireless technologies such as CDMA.
PNAPresence Network Agent
PNGPortable Network Graphics. A web graphics format using lossless compression (and decompression) and 48 bit color (unlike JPEG). Its proponents believe that it will also replace GIF and TIFF.
PNPPrivate Numbering Plan
PNSPPTP Network Server. See PAC
PoCPush/Press-to-Talk over Cellular. Refers to systems running over standard cellular systems that emulate the push-to-talk system of iDen and similar systems. See PTT.
POCSAGA paging protocol that runs at 512 or 2400 bps. Compare with FLEX, ReFLEX.
POIPoint of Interconnect
Point CodeA numeric SS7 address. 24 bits in the NANP, 16 bits in Japan, and 14 bits in most other countries
PoolingThe ability to share a block of 10,000 NANP phone numbers between carriers. See ITN and Thousands block pooling
POP(1)Population of a service area. Licenses are often valued based on this
POP(2)Point of Presence. A place where a carrier provides connectivity to its network
POP3Post Office Protocol Version 3. IETF RFC 1939
Port-inThe porting of a number from the perspective of the new service provider. See LNP and WNP
Port-outThe porting of a number from the perspective of the old service provider. See LNP and WNP
Portable BlockA block of 10,000 NANP directory numbers that contains at least one Ported DN
PortalA fancy name for a web page that provides a single point of entry for a suite of web services
Ported DNA DN that has been ported from one carrier to another. See LNP and WNP
POS(2)Packet over SDH
POS (1)Personal Operating Space. A space about a person or object about 10 meters in radius that envelopes the person. See WPAN
POTSPlain Old Telephone Service (incoming and outgoing calls, but no fancy features)
PPDRPublic Protection and Disaster Relief
PPDUPresentation PDU
PPP(1)Point-to-Point Protocol. IETF RFC 1661. Provides a reliable link to the internet over a single-user facility (e.g. phone line) that can carry several network protocols simultaneously. See PPP, PAP, CHAP
PPP(2)Peripheral Pre-Processor
PPTPPoint-to-Point Tunneling Protocol. Allows PPP to be tunneled through an IP network. Uses an enhanced GRE mechanism for flowcontrol and congestion control. Defined in RFC 2637. May be replaced by L2TP
PQoSPosition QoS. The desired/required/measured quality of position measuring accuracy and delay
PRACKIETF SIP Provisional Acknowledgement message
PRAMPPower Ramp
PRBSPseudo-Random Binary Sequence
PRC(1)Premium Rate Charging
PRC(2)Primary Reference Clock
PRC(3)People's Republic of China
Prepaid wirelessWireless services paid for in advance, as opposed to monthly billing. Technical challenges limit the services available, such as roaming and international calling
PRIPrimary Rate Interface (1.544 Mbps). See T1, DS1
Private long code maskUsed for encrypting TIA/EIA-95 conversations. Based on secret key information
PRLCDMA Preferred Roaming List. A database within an MS that prioritizes the systems that the mobile might encounter while roaming.
PRNProvide Roaming Number
ProtocolA specification of the messages used to communicate over one or more Interface
PS(1)Packet Switch(ed)
PS(2)Priority Service. See WPS, PACA
PS(3)Positioning Server.
PSAPPublic Service Answering Point. The place where 9-1-1 calls are answered
PSDPower Spectral Density
PSDCWAG Persistent Storage Drafting Committee. A WAP Working Group
PSDNPacket/Public Switched Data Network. Not be be confused with PDSN
Pseudolite(1)A GPS ground station that transmits a signal similar to a satellite that might not be visible to all GPS devices.
PSIDPrivate SID. Used to identify a virtual private wireless system (e.g. wireless PBX)
PSK(1)Phase Shift Keying. Information bits are identified by changes in phase of the carrier. Usually, the signal is split into two parts. I is unchanged, and Q is phase shifted by 90 degrees. Phase can be controlled by the amount of each path that is remixed upon output
PSK(2)Pre-Shared Key.
PSMMPilot Signal Strength Message. Used for CDMA triangulation
PSNPacket Switched Network
PSPDNPacket Switched PDN
PSS3GPP Packet Streaming Service.
PSTNPublic Switched Telephone Network. The 'phone system'.
PSVTPacket-Switched Video Telephony
PTMPoint-to-Multipoint (Broadcast)
PTTPush To Talk. Pressing a button on a phone initiates communications with a pre-defined group of other users. The system will usually give one radio the ability to transmit, and the remainder can only listen until the button is released or the phone exceeds the maximum time limit on the right to talk.
Public long code maskSee PLCM.
PUC(1)GSM Personal Unblocking Code. A code provided by a carrier to regain access to a SIM that has become locked due to multiple entries of an invalid PIN. If this code is entered incorrectly 10 times, the SIM will become permanently inoperable and must be replaced.
pUIMIDPseudo UIMID formed from the 8 bit prefix 0x80 and the least significant 24-bit SHA-1 extract of the EUIMID.
PUK(1)GSM Personal Unblocking Key. See PUC.
PUREGPower-Up Registration
PVProtocol Version
PVCPermanent VC
PVIPV Indicator
PZIDPacket Zone ID
QAMQuadrature Amplitude Modulation. A method of encoding a digital symbol in an analog symbol using combinations of phase and amplitude that are modulated at right angles to the main carrier. See 8QAM, 16QAM, 32QAM, 64QAM, 128QAM
QCELPQualcomm Code Excited Linear Prediction
QoEQuality of Experience. The subscriber's perception of their quality of service.
QoRQuery on Release. A method for implementing LNP
QoSQuality of Service. A list of measurable attributes such as bandwidth, delay and jitter that should be met for a specific communications service
QPSKQuadrature PSK used in CDMA. Phase can be in one of four states
QSIGISDN based signaling inter-PBX protocol.
QuintetA group of 5 security data elements used in AKA. Composed of RAND, expected user response (XRES), Cipher Key (CK), Integrity Key (IK) and network authentication token (AUTN)
R and RRevise and Resubmit. The usual treatment for a contribution to a standards committee
R-PInterface between a PDSN and a PCF that uses a GRE tunnel to carry user data and signaling messages.
R-SCHReverse SCH (from MS)
R-SGWRoaming SGW. Interface between SS7 SCCP and MTP to IP protocols
R-UIMRemovable UIM
RARegistration Authority
RABRadio Access Bearer
RACRouting Area Code. An 8 bit number identifying a routing area with a location aarea
RACFRadio Access Control Function. An IN term
RACHRandom Access Channel. Mobiles compete to access this shared Control Channel
Radio FrequencyElectro-magnetic radiation having a frequency in the range used for telecommunications, greater than that of the highest audio-frequency and less than that of the shortest infra-red waves.
Radio InterfaceThe interface between an MS and a BS
RADIUSRemote Authentication Dial-In User Service. An internet user authentication system. See IETF RFC 2138, 2139 and AAA
RAIGSM Routing Area Identification. Composed of LAI + RAC
RAKEA receiver technique which uses several baseband correlators to individually process several signal multipath components. The correlator outputs are combined to achieve improved communications reliability and performance
RANRadio Access Network
RANAPUTRAN RAN Application Part
RANDRandom number used for authentication purposes
RANDBSRandom number used for base station challenge authentication operation. See CAVE
RANDCRAND Confirmation. A portion of RAND used to try to confirm the value that was used by an MS during a Global challenge
RANDSSDRandom number used for CAVE SSD Update operation
RANDUThe random number used for a Unique Challenge
RAORevenue Accounting Office
RASCRadio Access System Controller. An IN term
RATRadio Access Technology. Used to distinguish between GPRS and UMTS in 3GPP networks.
Rate CenterThe location of a phone for billing purposes. Long distance charges are calculated based on the distance between two rate centers (often the switch location). Rate centers and competition combine to cause very inefficient number assignment, because every carrier operating in a rate center must be assigned at least 10,000 numbers. But, see Pooling
RATIRandom ATI. Compare with UATI
RBOCRegional BOC. One of 7 local exchange companies formed from the breakup of AT&T: NYNEX, Bell Atlantic, BellSouth, Southwestern Bell, Pacific Bell, US West and Ameritech
RCFRadio Control Function. An IN term
RDRequirements Document
RDFResource Description Format
RDVRoamer Database Verification (IS-847). Ability of HLR to query VLR database to determine whether information needed to support roamers is correct
REAGRegional EA Grouping. A geographical area (encompassing several EAs) used to license the AWS B, C and E bands.
RECCReverse Analog Control Channel
Recipient SwitchThe switch to which a number has been ported. See LNP
REDRandom Early Detection
Reed-SolomonA type of FEC
ReFLEXA two-way paging protocol related to FLEX. Operates at speeds up to 9600 bps inbound and 6400 bps outbound (25 kHz channel) or 25600 bps (50 kHz channel)
RegistrationThe process where an MS informs a system of its presence
Rel(1)Abbreviation for release of a specification (e.g. GSM Rel 5)
REL(2)SS7 ISUP circuit Release message
ReleaseReturning a trunk, transceiver or other telephony resource to the idle list
RESAuthentication response. A value calculated from at least a secret key and a random number, that can be used to infer that the respondent is in possession of the secret key, without revealing it.
RETURN RESULTMessage sent to successfully end TCAP transaction
REVALRecommendations on the Procedures for Evaluation of Radio Transmission Technologies for FPLMTS
Reverse 911Dialing up all landline phones within a geographical area to deliver a recorded message, e.g. about a weather emergency. This is usually a voluntary service
Revertive dialingCalling your own phone number. Often used to access a voice mail system
RFRadio Frequency
RFCIETF Request for Comments. Internet standard (well, not officially, but in practice many internet 'standards' are still just RFCs)
RFI(1)Request For Information
RFI(2)Radio Frequency Interference
RFIDRadio Frequency Identification. A small chip that is designed to allow the identification and tracking of an object (e.g.manufactured item, airline bag).
RFPRequest for Proposal
RFUReserved for Future Use
RIHRate Input Handler. Puts a price on usage (e.g. a phone call)
RijndaelEncryption algorithm chosen for AES (replacement for DES). Means 'Rhine Valley' in Flemish. Pronounced 'Rain Doll' (while clearing your throat)
RIL3GSM Radio Interface Layer 3
RIPRouting Information Protocol. Compare with OSPF
RLCRadio Link Control
RLHRate Load Handler. Loads rated transactions into the billing system and monitors the usage limits (e.g. for prepaid, fraud analysis)
RLP(1)Radio link protocol
RLP(2)OMA/3GPP Roaming Location Protocol between SUPL Location Platforms (SLP).
RNRadio Network
RNCRadio Network Controller
RNSRadio Network Subsystem
RNTIRadio Network Temporary Identity. See TMSI
ROARegistered Operating Agency
RoamerA mobile that is present in a system (MSC-V) that is not its home system
Roamer PortA phone number that allows Termination to a Roamer via the MSC-V
ROERRemote Operation Error. See ROSE
ROHCRObust Header Compression (and, if you're lucky, decompression). RFC 3095. Provides compression of IP, UDP, RTP and ESP headers using W-LSB. In future, compression of TCP, SIP and other header types is also planned. It is more robust than CRTP
ROIVRemote Operation Invoke. See RORJ
RORJRemote Operation Reject. See ROIV
RORSRemote Operation Result
ROSERemote Operations Service Element. A message packaging protocol
RouterAn IP packet switch. Compare with STP
RPC(1)Radio Port Controller. An IN term
RPC(2)Remote Procedure Call. A method of exchanging data between applications running on different machines. Compare with SOAP
RR(1)Radio Resource
RR(2)Resource Record. Basic storage element for DNS
RRCRR Control
RRMRR Management
RRPMIP Registration Reply
RRQMIP Registration Reply Request
RSReed-Solomon error correction code
RSA(1)Rural Statistical Area. CGSA for rural cellular systems. Also used for licensing the FCC AWS D band.
RSA(2)Rivest, Shamir and Adleman PKE algorithm. Also the name of a corporation based on commercialization of this algorithm
RSIDResidential SID. Used to identify a virtual residential wireless system
RSNRobust Security Network. The long-term security enhancement for WiFi that replaces both WPA and WEP.
RSSReceived Signal Strength. A measure of the strength of a radio signal
RSSIReceived Signal Strength Indication. Used to determine when a Handoff should be attempted
RSVPIETF Resource Reservation Protocol. RFC 2205. A control protocol for assigning bandwidth to packets based on their desired QoS
RTCPRTP Control Protocol.
RTFRadio Terminal Function. An IN term
RTP(1)ISUP Release to Pivot Capability. Allows a call connected to one switch to be redirected to another by dropping back to an earlier switch to optimize trunking
RTP(2)IETF Real Time Protocol. Used by SIP, among other protocols
RTSPReal Time Streaming Protocol
RTT(1)Radio Transmission Technology candidate for IMT-2000
RTT(2)Round trip time. The time for a message to get from origin to destination and back again. For communications based on the exchange of many small messages this is more important than the actual bandwidth.
RTT(3)Abbreviation for 1XRTT
RVCReverse analog Voice Channel
RXAbbreviation for receive or receiver
RXPA protocol that bridges ReFLEX networks together. Based on XML, HTTP and TCP/IP. See WCTP
RZReturn to Zero
S-CSCFServing CSCF. Handles IMS session states
S-SCMServing SCM
S/NSignal to noise ratio
S/REmergency services selective router
SASecurity Association
SA13GPP TSG SA Working Group 1 for Service Specifications.
SA23GPP TSG SA Working Group 2 for Architecture Specifications.
SA33GPP TSG SA Working Group 3 for Security Specifications.
SA43GPP TSG SA Working Group 4 for Codec Specifications.
SA53GPP TSG SA Working Group 5 for Telecom Management.
SAALSignaling ATM Adapatation Layer. Equivalent of MTP layer 2 for ATM networks used to carry SS7 traffic. Includes SSCF, SSCOP and MAAL
SABMSet Asynchronous Balanced Mode
SACCHSlow Associated Control Channel. A control channel that is transmitted at a low bit rate in parallel with digitized voice.
SAFERSafe And Fast Encryption Routine. Based on IBC
SAICSingle Antenna Interference Cancellation
SAMPSANSI-136 System Assisted Mobile Positioning through Satellite. TDMA, MS-assisted location determination, using GPS
SAPService Access Point. Identifies a particular user service, sending and receiving a specific class of data.
SAPISAP Identifier. Assigned by IANA.
SAR(1)Segmentation and Reassembly
SAR(2)Successive Approximation Converter. Type of analog-to-digital converter
SAR(3)Specific Absortion Rate. Amount of RF energy absorbed (e.g. for RF/health studies)
SASLSimple Authentication and Security Layer. IETF RFC 2222
SAT(1)Supervisory Audio Tone. One of three tones around 6 kHz that are transmitted from a base station to an MS by analog cellular (EIA/TIA-553)
SAT(2)SIM Application Toolkit
SCSteering Committee
SCADA(1)Supervisory Control and Data Acquisition.
SCC(1)SAT Color Code. A slight variation in frequency to limit false SAT detection
SCC(2)Service Control Code. A 1, 2 or 3 digit code followed by an asterisk (*) used for controlling switch capabilities during a call (e.g. 777*). Compare with FC
SCCPSignaling Connection Control Part. SS7 enhanced routing and identification layer
SCEService Creation Environment for the Intelligent Network (IN, WIN)
SCEGSmart Card Expert Group. A WAP Working Group
SCEMASecure Cellular Encryption Module Algorithm
SCFService Control Function. Most important part of an SCP
SCH(1)CDMA Supplemental Channel. Used for transmitting higher speed data
SCH(2)GSM Synchronisation Channel; downlink only frame synchronisation and identification of base station.
SCIDSubchannel Identity
SCM(1)Station Class Mark. Identifies the power class and transmission mode of an AMPS terminal
SCM(2)3GPP2 Session Control Manager. Manages multimedia sessions. Obsolete. See CSCF
SCPService Control Point. An SS7 network element used to control call processing (e.g. by providing database or intelligent network services)
SCPTCDMA Service Category Programming Teleservice
SCRStatic Conformance Requirements
SCTPStream Control Transmission Protocol specified in IETF RFC 2960. Similar to TCP, it differs in supporting multiple independent streams of packets which prevents a failure in one stream backing up packets in all streams.
SCVPSimple Certificate Validation Protocol. Allows a simple device to send a certificate to a server for validation. An IETF draft
SDBShort Data Burst
SDCAIndian Short Distance Charging Area
SDCCSupplementary DCC
SDCCHGSM Standalone Dedicated Control Channel.
SDFService Data Function (IN term)
SDFUSub-rate Digital Facility Unit
SDHSynchronous Digital Hierarchy
SDLSpecification Description Language
SDL(2)System Design Language
SDOStandards Development Organization. The TIA and ATIS are SDO's
SDPIETF Session Description Protocol that describes multimedia sessions for the purposes of session announcement, invitation, and other forms of multimedia session initiation. See SIP
SDR(1)Software-Defined Radio. A radio that can operate in different modes (e.g. frequency bands, modulation schemes) based on the software that is currently loaded and active in the device.
SDR(2)Special Drawing RIghts. A virtual currency used for exchange of billing information between carriers.
SDSLSymmetric DSL. Bit rates are the same in both directions
SDU(1)Selection and Distribution Unit. Part of a base station that contains the voice coders
SDU(2)Service Data Unit
segmentationThe process of breaking a long protocol message into pieces that are no longer than the maximum allowed by lower protocol layers. Oh, and reassembling them later!
SensitivityThe ability to receive a radio signal very near to the thermal noise level. The more sensitive the receiver, the lower the required incident radio signal required for acceptable reception.
SerGGSMA Services Group
Serving MSCThe MSC currently serving an MS
SETSUPL Enabled Terminal. Supports the location procedures of SUPL, interacting with the network over the user plane bearer.
SettlementThe process of exchanging revenue between telecommunications carriers
SF_EUIMID(1)Short Form EUIMID. Based on the MEID format and allocated from the same numbering space. However, the SF_EUIMID of an R-UIM will never be the same as the MEID of the phone that it is inserted into.
SFIShort File Identifier in a UIM or SIM
SG(1)ITU Study Group
SG(2)Signaling Gateway. Converts an internet protocol to another protocol, e.g. SS7
SG(3)GSMA Security Group
SGCPSimple Gateway Control Protocol. A VoIP call control standard. Also see MGCP
SGMLStandardized Generalized Markup Language. The father of XML
SGWSignaling Gateway
SHA-1Secure Hash Algorithm. Produces a condensed representation ('hash') of a string of bits (e.g. protocol message). Because it is computationally infeasible to determine the original text knowing the digest it is useful in authentication algorithms. Because it is also infeasible to find two strings that produce the same digest, it is also useful in digital signing algorithms. See MD5.
SHDSLSingle-pair high speed DSL
SIDSystem Identifier. A 15 bit identifier of an AMPS wireless license or system
SIFSignalling Information Field. The payload of an SS7 MTP message
SIGSpecial Interest Group
SignalingMessages used to control calls, assign resources, maintain and monitor telecommunications systems
SIM(1)GSM Subscriber Identification Module (Smart Card). Compare with UIM
SIM(2)Service Interaction Manager. A WIN concept
SIMPLESIP for IM and Presence Leveraging
SINSpecification Information Node
SINADSignal + Noise + Distortion
SIPSession Initiation Protocol. An IETF IP protocol for VoIP (packetized voice) call processing. See SDP.
SIP-ASSIP Application Server
SIP-TVariant of SIP that encapsulates ISUP signaling to provide support for circuit-switched communications
SKeySession Key
SLAService Level Agreement. A carrier agrees to provide a certain level of service (e.g. availability, bit rate, voice quality) and provide significant discounts if the levels are not met
SLCSUPL Location Center. Coordinates the operations of SUPL in the network.
SLEEService Level Execution Environment
SLF3GPP Subscription Locator Function
Slow FadingFade duration long relative to channel frame length
SLP(1)Service Logic Program
SLP(2)SUPL Location Platform. Consists of an SLC and an SPC.
SLSSignaling Link Selection
SMSession Management
SM-MTMobile Terminated Short Message
SM-SCShort Message Service Center (see MC)
Smart CardSee UIM, SIM
SMCKOTA Secure Mode Ciphering Key. Allows for the encryption of provisioning data that is going to be transmitted over a radio interface
SMDPPTIA/EIA-41 SMS Delivery Point-to-Point message
SMDSSwitched Multimegabit Data Service
SME(1)Short Message Entity (SMS terminal)
SME(2)Signaling Message Encryption
SMGSubject Matter Group
SMILSynchronised Multimedia Integration Language
SMPPShort Message Peer-to-Peer Protocol. Promoted by the SMPP Forum
SMRSpecialized Mobile Radio. A form of private mobile radio that allows one talker and multiple listeners in a group (e.g. taxi company)
SMS(1)Short Message Service
SMS(2)Service Management System. Communicates number portability (LNP) and pooling information between carriers.
SMSCBSee Broadcast SMS
SMSCHSMS Point-to-Point Channel
SMTPSimple Mail Transmission Protocol defined in IETF RFC 2821
SMVCDMA Selectable Mode Voice Coder
SN(1)Service Node. A combination of SCP and IP functionality
SN(2)E.164 Subscriber Number
SNDCPSub-Network Dependant Convergence Protocol
SNMPSimple Network Management Protocol. Network management protocol usually used with TCP/IP networks, and others
SNR(1)See S/N
SNR(2)Serial number. The unique 6 digit number assigned to a GSM phone within an IMEI
SOAService Order Activation. For LNP, this represents an interface between a carrier and the NPAC SMS
SOAPSimple Object Access Protocol. XML based language for exchanging data between internet applications on different machines. Bypasses firewalls by being disguised as XML/HTML. Compare with CORBA and RPC
SOCSystem Operator Code. Used in IS-136 TDMA digital systems to identify the wireless carrier
SOHOSmall Office/Home Office
SoLSASupport of Localized Service Area
SONETSynchronous Optical Network
SoRStatement of Requirements.
SP(1)Signaling Point. An SS7 network node: SCP, SSP or STP
SP(2)ANSI standards proposal number
SPAJAIN Service Provider APIs
SPASMSubscriber Parameter Administration Security Mechanism
SPCSS7 Signaling Point Code. Also PC
SPIService Provider Identification
SPINASubscriber PIN Access
SPINISubscriber PIN Intercept
SPLService Programming Lock. A method of preventing a mobile from changing from the service the subscriber has contracted with
SPMCSignaling Point Management Cluster
SpoolSimultaneous Peripheral Operations On-Line. Writing a print or other file to a special area of memory or disk so that it can be printed (or otherwise processed) while other computer operations are ongoing.
SPSServing PS
SPSServing PS
SQMSubscription Quality of Service Manager
SQNSequence number (used for authentication/encryption). Its use can prevent replay attacks, where the same information is transmitted by a fraudulent device as by the legitimate device.
SRCWAP Specification Requirements Committee
SRDCTIA Standards Requirement Document
SRESExpected response to authentication challenge for GSM authentication. Compare with AUTHR
SRFService Resource Function. Most important part of an IP
SSSupplementary/Supplemental Service
SS7Signaling System Number 7 (common channel telecommunications packet switching)
SSCFService-Specific Coordination Function. Maps between SAAL and higher layer protocols (e.g. SS7 MTP Layer 3). This includes responsibility for link changeover and flow control See ATIS T1.645
SSCOPService Specific Connection-Oriented Protocol. Part of SAAL that provides reliable point-to-point communications with sequencing, retransmission on error, flow control, keep-alive, connection control. See ATIS T1.637.
SSDShared Secret Data. A secondary key used in most CAVE operations
SSD-APortion of SSD used for Authentication
SSD-BPortion of SSD used for voice, data and signaling encryption
SSFService Switching Function. An IN term for a switch
SSIDService Set Identifier. An identifier of an 802.11 network.
SSLSecure Socket Layer. Secures TCP connections (e.g. for m-commerce)
SSNSub-system number. Along with PC, identifies an SS7 network application or a virtual SS7 network entity
SSOSingle Sign On. Having one set of authentication data to access many services.
SSPService Switching Point (e.g. MSC). An SS7 SP that contains switching and signaling functions.
STEnd of pulsing signal. An MF tone
Stage IThe portion of a standard that describes the external behavior of a standard or capability
Stage IIThe portion of a standard that describes the flow of messages through a network to implement Stage I behavior
Stage IIIThe portion of a standard that completely describes a protocol, to the level of bit encoding of messages and parameters, based on Stage II message flows
STKSIM Toolkit
STMSynchronous transport mode
STPSS7 signaling transfer point (i.e. packet switch). An SS7 SP that provides routing services. Compare with Router
STU-IIISecure Telephone Unit - III. US government telephone encryption system
SUASCCP User Adaptation Layer. Replaces SCCP and M3UA. Resides above SCTP and below the application in an IP telecom signaling protocol stack.
SUPLOMA Secure User-Plane Location architecture for LCS with intelligent, IP-enabled mobile devices.
surveillanceLawfully (hopefully) authorized monitoring of communications
SVCSwitched Virtual (data) Circuit
SVNGSM Software Version Number. A 2 digit code identifying a line of mobiles. See IMEISV
SVPSwitched Virtual Path
SWAPShared Wireless Access Protocol. Being defined by HRFWG. Operates in the 2.4 GHz ISM band. Abandoned in 2003.
SWG3GPP Sub-Working Group
SynchronousData that is transmitted as a regular, precisely clocked, stream of bits. A pattern of bits is used as a filler for times when there is no data to transmit. Compare with Asynchronous
SyncMLA standard for synchronizing mobile devices.
Systemic InterferenceRF interference within a channel used in a wireless system that emanates from other elements of the system itself, and thus has predictable characteristics. For example, transmissions on the same channel form other base stations (intended for other mobiles). Contrast with Non-systemic Interference and Intermodulation Interference
T-BCSMTerminating BCSM
T1(1)Group of standards committees related mostly to wireline standards, such as SS7, but also North American GSM standards
T1(2)A digital link carrying 24 DS0 channels. Used mostly within North America. Compare with E1
T1A1Renamed the ATIS Network Performance, Reliability and Quality of Service Committee in 2004.
T1E1Renamed the ATIS Network Interface, Power, and Protection Committee in 2004.
T1M1OA&M standards committee for North American wireline networks. Renamed as the ATIS Telecom Management and Operations Committee in 2004.
T1P1Personal Communications (i.e. US GSM) standards committee for North America. Renamed the ATIS Wireless Technologies and Systems Committee in 2004.
T1S1SS7 standards committee for North America. Split into the ATIS Packet Technologies and Systems Committee and the Protocol Interworking Committee in 2004.
T1X1Renamed the ATIS Optical Transport and Synchronization Committee in 2004.
T3Physical device carrying one DS3 service
TA(1)Terminal Adaptor
TA(2)Timing Advance. An adjustment in the time of cellular transmission based on the distance of a terminal from a base station. This can be used to estimate the distance of a terminal and determine its approximate location.
TAC(1)Total Access Communications. A name used by Motorola in several products, such as TACS, DataTAC
TAC(2)Type Approval Code. 6 digit part of IMEI that is assigned by a central authority (e.g. national telecom regulatory body)
TACSTAC System. Basically AMPS in the 900 MHz frequency band
TADIGGSMA Technology and Documentation Interoperability Group.
TandemAny switch that is used to receive and route traffic (e.g. phone calls), but neither originates nor terminates them
TAP(1)Transfer Account Procedure. A billing record format used mainly by GSM carriers
TAP(2)Telocator (now PCIA) Alphanumeric Protocol for paging, now also used for SMS.
TAPSTETRA Adcanced Packet Service. A European data system based on GPRS and EDGE designed to work with TETRA. Ideal data performance is 600 kbps with frequency hopping and 466 kbps without. Defined by ETSI TS 101.962.
TARTemporary Alternative Routing
Target MSCThe destination MSC for an inter-system handoff
TAS(1)Telephony Application Server
TBCDTelephony BCD. Digit 0 is encoded as 10, as on a rotary dial phone
TCAPTransaction Capabilities Application Part. Message packaging standard used by TIA/EIA-41, LNP, 800 and other SS7-based applications. Defined in ANSI T1.114
TCBTelecommunication Certification Body. A national authority for the certification of radio devices.
TCCTelephony Country Code
TCGTrusted Computing Group
TCHTraffic Channel. Often classified as full rate(FR) or half rate (HR)
TCPTransmission Control Protocol. A protocol that provides for reliable delivery of messages over the internet. See UDP and IP
TCP/IPTCP used over IP
TD-CDMATDD mode of operation for UTRA
TDD(1)Telephone Device for the Deaf. See TTY
TDD(2)Time Division/Domain Duplex. See TDMA
TDESTriple DES. An encryption algorithm with a strength of about 112 bits. See AES, DES.
TDMTime Division Multiplexing. See also TDMA
TDMATime Division/Domain Multiple Access. Modulation technique used by D-AMPS and GSM
TDOATime Difference of Arrival. See TOA and OTDOA
TDPTrigger Detection Point. See IN
TDS-CDMATime Division Synchronization CDMA. Chinese 3G radio access proposal
TDSOCDMA Test Data Service Option
TEData Terminal Equipment. A personal computer, for example
TEGWAP Telematics Expert Group
TeleserviceA telecommunications service provided between two telecommunications terminals (e.g. a call between two phones or a short message between two wireless devices). Contrast with Bearer capability
TeraPrefix to indicate one trillion (e.g. Tera-bit). Abbreviated T
TerminationThe process of reaching the destination of a call. Not to be confused with Disconnection
tESNA unique ESN for a phone. See pESN, UIMID, pUIMID
TETRATerrestrial Trunked Radio. A European PAMR system using 25 kHz channels.
TFOTandem (or Transcoder) Free Operation. Elimination of the Voice Coder from a digital mobile-to-mobile call (assuming that both mobiles are capable of using the same type)
TFTTraffic Flow Template. Used to determine the QoS that applies to a specific packet.
TGTask Group of ITU-R
Thermal NoiseRadio frequency noise associated with thermal activity. At a typical temperature of 300 degrees Kelvin (26.84 degrees Celsius), thermal noise is -174 dBm per hertz, or 114 dBm in a 1 MHz channel.
Thousands block poolingThe ability to share a block of 10,000 NANP phone numbers in groups of 1,000 between carriers. Individual phone numbers within the block can then be ported (using LNP) to other carriers
throughputThe actual traffic supported, as opposed to the raw bandwidth. Bandwidth that does not result in throughput may be due to packets containing errors, retransmissions, errorneous routing and many other causes. See goodput and badput
TIATelecommunications Industry Association. A trade association that, among other things, defines standards for cellular and PCS, specifically AMPS, NAMPS, CDMA and TDMA
TIA-136ANSI version of the TDMA air interface standard. Replaces IS-136 and TIA/EIA-136
TIA/EIAA prefix for a standard produced by the TIA in association with the EIA
TIA/EIA-124Wireless call detail and billing record format for online transfer. Replaces IS-124
TIA/EIA-136ANSI version of the TDMA air interface standard. Replaces IS-136. Replaced by TIA-136
TIA/EIA-41Wireless intersystem operations standard. Previously called IS-41
TIA/EIA-41-DIntersystem Operations Standard. Replaces IS-41
TIA/EIA-634A-interface standard between BS and MSC
TIA/EIA-93Wireless-PSTN interface standard. Replaces IS-93
TIA/EIA-95CDMA air interface standard
TIA/EIA-95-BThird generation CDMACDMA air interface standard. Replaces IS-95
TIFFTagged Image File Format. Supports up to 24 bit color. Files tend to be large, but high quality. Perhaps because of the file size, it is not supported by many browsers. cf GIF, JPEG, PNG
TIPHONTelecommunications and Internet Protocol Harmonization over Networks
TISPAN(1)Telecoms and Internet Converged Services and Protocols for Advanced Networks. See etsi.org/tispan
Title IIIA surveillance that is authorized to collect content (e.g. voice communications. Contrast with pen register and trap and trace
TKIPTemporal Key Integrity Protocol. A modification to WEP that increases security by frequently changing keys.
TL1Telcordia (formerly Bellcore) MML language for telecommunications network monitoring.
TLDNTemporary Local Directory Number. A number used for routing calls from the Home MSC to MSC-V in ANSI-41. Compare with MSRN
TLLITemporary Link Level Identity
TLSTransport Layer Security
TLVTag, Length Value. Encoding of parameters by including an identifier (tag), length (of value) and the actual parameter contents (value). Used by BER and TCAP, for example. cf AVP
TM3TIA committee for standardization of Terrestrial Mobile Multimedia Multicast. Created in 2005. Also known as TR-47
TMNTelecommunications Management Network. A network management protocol, used to logically define managed objects
TMOTrunked Mode Operation. A cellular-like mode of operation of a PAMR system. Compare with DMO.
TMSITemporary mobile station identity. Used as a shorter, more private, mobile identifier. Identifies the system that assigned it, and not directly the MS
TNRNTerminating Network Routing Number
TOATime of Arrival. A technique for location a radio by comparing the time of signal arrival at multiple points. Compare with AOA
TONType of Number
TOSType Of Service
TPDUTransport PDU
TPKT(1)An early version of ITOT.
TPPTerminating Party Pays. The mobile pays for airtime, whether it is making or receiving a call. cf CPP
TR(1)3GPP Technical Report. These are informative, as opposed to TS
TR(2)TIA Technical Review standards committee prefix
TR-45TIA Standards Committee responsible for AMPS-based cellular and PCS standards, including TDMA and CDMA digital
TR-45.1TIA analog cellular standards subcommittee
TR-45.2TIA Standards Subcommittee responsible for intersystem protocols
TR-45.3TIA TDMA digital cellular/PCS standards subcommittee
TR-45.4TIA BS/MSC "A" interface standards subcommittee
TR-45.5TIA CDMA digital cellular/PCS standards subcommittee
TR-45.6TIA CDPD standards subcommittee
TR-45.7TIA OA&M cellular standards subcommittee. Now defunct.
TR-47See TM3
Traffic ChannelA portion of a radio channel used to transmit one direction of a digital voice conversation. Compare with Voice Channel
Transcoder(1)A device that converts a communication signal from one system to another, e.g. analog to digital or air interface digital to PCM.
TranscodingConversion from one voice (or other media format) coder to another. Multiple transcoding operations can seriously reduce the end-to-end quality.
TransparentData that is, to lower protocol layers, simply a sequenced collection of bits. Good protocol design tries to make all protocol layers transparent to all others, although often violations of this principal are necessary
trap and traceCollection of the identity of a part originating a call for surveillance purposes
TRAUTranscoding Rate and Adaptation Unit
TrFOTranscoding Free Operation. Establishment of a call without a transcoder.
TripletA group of 3 security data elements used in GSM authentication. Composed of network challenge random number (RAND), expected user response (SRES) and Cipher Key (CK)
TS3GPP Technical Specification. Normative, as opposed to TR
TSARTeleservice segmentation and reassembly for TIA/EIA-136
TSBTIA Telecommunications Systems Bulletin. Often used as an addendum or erratum to a published interim standard
TSGTechnical Specification Group. Part of the 3GPP and 3GPP2 processes
TSG CN3GPP TSG for CN standardization
TSG GERAN3GPP TSG for GSM standardization
TSG N3GPP2 TSG for inter-system network protocols. Replaced by TSG-X.
TSG RAN3GPP TSG for W-CDMA standardization
TSG S3GPP2 TSG for service and system aspects (requirements, architecture, Stage 1 descriptions etc.).
TSG SA3GPP TSG for defining services and architecture of W-CDMA 3G systems
TSG-A3GPP2 TSG for the IOS
TSG-C3GPP2 TSG for the cdma2000 radio interface
TSG-N3GPP2 TSG for network procotols. Replaced by TSG-X
TSG-P3GPP2 TSG for packet data protocols. Replaced by TSG-X
TSG-T3GPP TSG for terminal and UIM standardization
TSG-X3GPP2 TSG for the core network. Formed by the merger of TSG-N and TSG-P
TSITime Slot Interchange
TTTranslation Type. Defines the type of routing address used by GTT (e.g. E.164 directory number, E.212 IMSI etc.).
TTATelecommunications Technology Association. Standardizes wireless network protocols in Korea
TTC(1)Telecommunication Technology Committee. Telecommunications standardization in Japan
TTC(2)Terminating Toll Center
TTCNTree and Tabular Combined Notation. ISO/International Electrotechnical Commission IEC 646-3 is a notation for the specification of tests for communication systems. A TTCN-specified test suite is a collection of various test cases together with all of the declarations and components needed.
TTYA device used by the deaf or hearing-impaired to communicate text messages over telephone systems. It runs at 45.45 bps. See TDD
TunnelAn extra protocol addressing layer used to carry data where the inner addressing layer will not take it. Often used in IP, e.g. as part of Mobile IP or VPN
TunnelingSending data transparently through a foreign network. Usually implies the use of a larger than optimal number of protocol layers
TUPTelephone User Part. Forerunner protocol to SS7 ISUP
TWGGSMA Terminal Working Group
TXAbbrevation for transmission or transmitter
U/LUplink (e.g. from mobile to base station). Compare with D/L.
UA(1)User Agent. An application operating on behalf of a user device (e.g. phone or computer). See MM1.
UA(2)GSM Unnumbered Acknowledge
UAProfWAP UA Profiles Drafting Committee. Or a reference to the profiles that they generate.
UASLIndian Unified Access Services Licence. Replaces CMSP. This allows both GSM and CDMA carriers, as well as other technologies, to be implemented.
UATIUnicast ATI. A 128 bit address for a HRPD device. A 32 bit short version is available for transmission.. The AAA returns the IMSI or MIN to the serving network. Compare with RATI
UCPUniversal Computer Protocol. Part of ERMES is an ETSI paging system . The most commonly used operations are: 01 - Call Input Operation; 03 - Call Input With Supplementary Services Operation; Operation 30 - SMS Message Transfer Operation; and Operation 51 - Submit Short Message Operation.
UDHUniversal Data Header
UDPUser Datagram Protocol. An internet protocol providing basic services only. Compare with TCP
UDRRADIUS Usage Data Record. Captures accounting data for packet data sessions.
UDTSS7 MTP unit data message. Carries a payload of about 250 octet
UDTSUDT service message. Used to send error responses to UDT messages
UEUser Equipment (e.g. phone and all peripherals such as USIM)
UEAUMTS Encryption Algorithm. May be null (no encryption) or Kasumi
UGIDUser Group Identification
UHDMCDMA Universal Handoff Direction Message
UHFUltra-High Frequency. 300-3000 MHz (used in the US and Canada as television channels 14-83)
UIAUMTS Integrity Algorithm. One possibility is Kasumi
UIDUser Interactive Dialog
UIMUser Identification Module (Smart Card). See SIM
UIMIDUIM Identifier. Really just a 32-bit ESN assigned to a UIM that supports CDMA operation. See tESN.
ULUplink. Radio link in the direction 'up' to network. Compare with DL
ULDCH3GPP Enhanced Uplink DCH
UmRadio interface between MS and BSS/BSC
UMLETSI Universal Modelling Language
UMTSUniversal Mobile Telecommunications System (a 3G initiative). See www.umts-forum.org. It operates in 5 MHz channels at 3.84 Mcps with 200 kHz between channels.
UNIUser-Network Interface
UNICODEA text encoding method that, by using more than 8 bits, can code special characters for many languages. Standardized as ISO 10646. Compare with ASCII, EBCDIC and ISO-8859-1
Unique ChallengeA method of encryption using a unique random number (RANDU) as a challenge
UplinkPath from terminal to base-station
UPRCTIA User Performance Requirements document. Now know as SRD
UPTUniversal Personal Communications
URIUniform Resource Identifier. A superset of URL and URN. If an object is on the internet and does not have one of these it really doesn't exist.
URLUniform Resource Locator. Form of internet address usable by a browser. Of the format ":". http, ftp and mailto are examples of schemes. The remainder of the URL is defined by the scheme, with some restrictions on the characters that can be used. Illegal ASCII characters can be included with the %XX notation, where XX is the two digit hexadecimal value of the character.
URNUniform Resource Name
USATUSIM Application Toolkit
USCFUser Selected Call Forwarding. Allows an incoming call to be diverted before it is answered, either to a preset number, or to a number specified at the time of diversion. Closely related to AH
USIMUser Services Identity Module or Universal Subscription Identity Module. SIM for UMTS. See UIM
USSDGSM Unstructured Supplementary Service Data
UtThe 3GPP interface between the UE and AS.
UTCUniversal Coordinated Time (don't ask)
UTMUniversal Transverse Mercator.
UTRAUniversal Terrestrial Radio Access.
UTRANUniversal Terrestrial RAN. The BS, BTS etc. for W-CDMA/UMTS
UU-SIGNALUser to User Signaling
UWBA radio technology that uses short very high speed bursts of data over short distances. It is controversial because some claim that it can share spectrum with other users, and others claim that it will cause unacceptable interference.
UWCUniversal Wireless Consortium. Promotes D-AMPS technologies around the world
UWC/136TDMA digital cellular/PCS based on the IS-136 or TIA/EIA-136 standards
UWCCUniversal Wireless Communications Consortium. Proponent of TDMA digital systems based on UWC/136. Disbanded at the end of 2001.
V and VVerification and Validation. A committee review of a standard before formal ballot
VAValidation Authority
VADVoice Activity Detection. A system that not only detects the absence of voice, and prevents transmission of unecessary digitized voice during this time
VARValue-added Reseller
VASValue Added Service
VASPVAS Provider. A company that provides a service (e.g. web content) without being the carrier.
VCVirtual Circuit
VCIVC identifier
VDSLVery high speed DSL, providing about 58 Mbit/sec in both directions. Available as asymetric (see ADSL) or symmetric (see SDSL). See VDSL Alliance
VDSL AlliancePromoters of VDSL
VGCVoice Group Call
VGCSVoice Group Call Service
VHEVirtual Home Environment
VHFVery High Frequency. 30-300 MHz (used in the US and Canada as television channels 2-13)
VLANVirtual LAN. A subset of a LAN where files and services not available to a user are hidden.
VLRVisitor Location Register
VMACVoice Mobile Attenuation Code
VMSVoice Message System
vocoderVoice Coder or codec
Voice ChannelA radio channel used to transmit one direction of an analog voice conversation. Compare with Traffic Channel
Voice CoderConverts an analog voice signal into a digitally coded representation, and vice-versa. Wireless voice coders often also compress the voice into a bit rate from 8kbps to 13 kbps. Also called codec or vocoder
VoIPVoice over IP
VP(1)Voice Privacy (i.e. encryption)
VP(2)Virtual Path
VPIVP Identifier
VPIMVoice Profile for Internet Mail
VPMVoice Privacy Mask
VPNVirtual Private Network
VSARADIUS Vendor Specific Attribute. A field used to transmit data for a particular accounting application (e.g. cdma2000 packet data).
VSELPVector Sum Excited Linear Prediction
W-CDMAPhysical layer of the FDD mode of operation of UTRA. A 'European' version of CDMA and the 3G evolutionary step planned for GSM. Operates in pairs of 5 MHz channels at 3.84 Mcps
W-LSBWindow-Based LSB encoding for IP header compression (and decompression). Part of ROHC
W3CWorld Wide Web Consortium
WADGPS(1)Wide Area Differential GPS. Provides signal correction information from a number of ground reference stations.
WAEWireless Application Environment. See WAP
WAG(1)Wireless Applications Group
WAG(2)WLAN Access Gateway
Walsh codesA group of 2N vectors or words which contain 2N binary elements which with themselves and their logical inverses form a mutually orthogonal set.
WANWide Area Network. Compare with LAN, MAN
WAPWireless Application Protocol. A new protocol that is supposed to provide more efficient internet access from wireless phone. See also WML
WAP W3CWAP - W3C Coordination Committee
WARWLAN Access Router. Manages traffic into and out of a wireless LAN.
WARCWorld Administrative Radio Convention
WASPWireless Application Service Provider
WASUWireless Access Subscriber Unit
WATMWireless ATM
WATSWide Area Telephone Service
WAVESee 802.11p
WBMPWireless Bit MaP. A WAP graphic format
WCMPWireless Control Message Protocol. Protocol for reporting errors and performing loopback testing in WAP. Based on ICMP
WCTPWireless Communications Transfer Protocol. An interface between internet applications and messaging service providers (e.g. paging carriers). Developed by wctp.org. See RXP
WDMOptical Wavelength Division Multiplexing
WDPWireless Datagram Protocol. See WAP
WEMTCDMA Wireless Enhanced Messageing Teleservice
WEPWired Equivalent Privacy. First security system for 802.11 WLAN. Has known security weaknesses in the algorithm and the use of fixed keys. WEP derives a 64 bit RC4 key from a 40 bit AP-specific key and a 24-bit IV that is unique to the session. Compare with WPA
WFQWeighted Fair Queuing
WGWorking Group
WGS-84World Geodetic System 1984
WIWork Item
WID3GPP WI Description.
WIFWireless Interconnect Forum (managed by Telcordia)
WiFiIEEE 802.11b wireless LAN system
WIGWAP Interoperability Group
WIMWAP Identity Module
WiMaxIEEE OFDM radio interface.
WIMSWireless Multimedia Message Service
WINWireless Intelligent Network. Protocol with similar goals as IN, AIN and CAMEL
WIN Phase ISupports voice controlled services, incoming call screening and CNAP/CNAR
WIN Phase IISupports billing-related services, including Prepaid and Freephone (i.e. 1-800, including airtime)
WIN Phase IIISupports location-based services, such as location sensitive billing and intelligent directory assistance
WIPWIN Implementation of PAS
WIPPWireless Internet Protocol Partnership
WLAOptical Wavelength Adapter
WLANWireless LAN, of which the most popular is WiFi
WLLWireless Local Loop. See FWA
WMLWireless Markup Language. An HTML-like page description and scripting language, that is an essential part of WAP. Compare with cHTML and XHTML
WNEWireless Network Entity
WNOWireless Network Operator. A carrier
WNPWireless Number Portability. LNP for wireless phones
WNP Phase IThe ability for a switch to route to a ported number in another switch
WNP Phase IIThe ability for a switch to allow numbers to be ported in or out of its number range
WNP Phase IIIThe ability to support services such as short message service in a number portability environment
WPWorking Party
WPAWiFi Protected Access. An enhanced version of WEP that does not rely on a static, shared key.
WPANWireless Personal Area Network. Standards are being defined by IEEE 802.15
WPGWAP WIreless Protocols Group
WPSWireless Priority Service. See PACA, PS, NS/EP
WrInterface between Proxy AAA and WLAN access network.
WREWireless Residential Extension - home base station
WsInterface between Proxy AAA and Home system AAA.
WSDLWeb Service Description Language
WSIWireless Service Indication
WSPWireless Session Protocol. See WAP
WTAWireless Telephony Applications
WTAIWTA Interface
WTBUS FCC Wireless Telecommunications Bureau
WTLSWireless Transport Layer Security. See WAP
WTPWireless Transaction Protocol. See WAP
WWANWireless WAN
wwwWorld-Wide Web
WxInterface between AAA and HSS
WZ1World Zone 1. An obsolete telephone numbering term for countries identified by country code 1 ( USA, Canada and some Caribbean nations)
X.25An ITU/CCITT defined general purpose packet switching protocol
X.500The ISO directory protocol. See DAP, LDAP, DNS
xDSLRefers to all the DSL variants
XHTMLExtensible HTML. A version of HTML defined by XML and designed to be extensible. This may also be the evolutionary path for cHTML and WML
XMACExpected MAC
XMLExtensible Markup Language. A meta-language that can be used to define languages like HTML and WML
XORExclusive OR. A boolean operation, often used in cryptography. The exclusive-or of two bits is 1 if they have the same value and 0 if they have different values. This operation has the nice property that no information is lost. For example, (A xor B) xor B = A and (A xor B) xor A = B. Try that on any other boolean operation!
XRESExpected response to authentication challenge. For AKA it is derived from RAND using f2. Compare with AUTHR
XUDTExtended UDT. Supports message segmentation
Z.300An ITU-T series of specifications related to MML
ZBTSIZero Byte Time Slot Interchange (TSI). Bits 2 through 193 of each DS1 frame are scrambled to minimize the possibility of an all-zero octet. If all zero octets are still found, a group of all-ones is substituted. Due to its complexity this method is not often used.
ZCSZero Code Suppression. The seventh bit of an all-0 octet is replaced by a 1-bit. Only applicable to voice because there is no way to remove this one bit error.
ZigBeeA 'cable replacement' radio technology. Somewhat a competitor to Bluetooth although it is designed more for M2M applications (home, business and inustrial automation). It claims to be cheaper and use less power. It uses unlicensed bands at 2.4 GHz, 915 MHz (US) or 868 MHz (Europe). Data speeds are 20-250 kbps depending on the frequency band used. The communications range is from 10 to 75 meters. Developed by the ZigBee Alliance and standardized as IEEE 802.15.4
ZRPZone Routing Protocol. An internet routing protocol that focuses on routing updates within a zone.