GSM terms, acronyms and definitions : A to O

Bruevich · Moderator Joined: 12 Feb 2006 Posts: 232

1G
The first generation of analogue mobile phone technologies including AMPS, TACS and NMT

2G
The second generation of digital mobile phone technologies including GSM, CDMA IS-95 and D-AMPS IS-136

2.5G
The enhancement of GSM which includes technologies such as GPRS

3G
The third generation of mobile phone technologies covered by the ITU IMT-2000 family

3GPP
The 3rd Generation Partnership Project, a grouping of international standards bodies, operators and vendors with the responsibility of standardising the WCDMA based members of the IMT-2000 family

3GPP2
The counterpart of 3GPP with responsibility for standardising the CDMA2000-based members of the IMT-2000 family. 3GPP2 is spearheaded by ANSI

8PSK
Octantal Phase Shift Keying

A5/1/2/3/8X
Encryption algorithms for GSM networks

AAL
ATM Adaptation Layer

ABR
Available Bit Rate

A-bis
Interface between the BSC and BTS in a GSM network

AB
Access Burst; used for random access and characterised by a longer guard period to allow for burst transmission from a MS that does not know the correct timing advance when first contacting a network

ACTE
Approvals Committee for Terminal Equipment

ACTS
Advanced Communications Technologies and Services – a European technology initiative

ACU
Antenna Combining Unit

ADPCM
Adaptive Differential Pulse Code Modulation; a form of voice compression that typically uses 32kbit/s

AFC
Automatic Frequency Control

AGCH
Access Grant Channel; downlink only, BTS allocates a TCH or SDCCH to the MS, allowing it access to the network

Air interface
In a mobile phone network, the radio transmission path between the base station and the mobile terminal

A-interface
Interface between the MSC and BSS in a GSM network

AM
Amplitude Modulation

AMPS
Advanced Mobile Phone System, the analogue mobile phone technology used in North and South America and in around 35 other countries. Operates in the 800MHz band using FDMA technology

AMR
Adaptive Multi-Rate codec. Developed in 1999 for use in GSM networks, the AMR
has been adopted by 3GPP for 3G

Analogue
The representation of information by a continuously variable physical quantity such as voltage

ANSI
American National Standards Institute. An non-profit making US organisation which does not carry out standardisation work but reviews the work of standards bodies and assigns them category codes and numbers

ANSI-136
See D-AMPS

API
Application Program Interface

AoC
Advice of Charge

ARIB
Association of Radio Industries and Businesses. An organisation established by Japan’s Ministry of Posts and Communications to act as the standardisation authority for radio communication and broadcasting

ARPU
Average Revenue Per User

ASCII
American Standard Code for Information Interchange

ASIC
Application Specific Integrated Circuit

ASP
Application Service Provider

Asymmetric Transmission
Data transmissions where the traffic from the network to the subscriber is at a higher rate than the traffic from the subscriber to the network

A-TDMA
Advanced Time Division Multiple Access

ATM
Asynchronous Transfer Mode; a multiplexed information transfer and switching method in which the data is organised into fixed length 53-octet cells and transmitted according to each application’s instantaneous need

AUC
Authentication Centre; the element within a GSM network which generates the parameters for subscriber authentication

Bandwidth
A term meaning both the width of a transmission channel in terms of Hertz and the maximum transmission speed in bits per second that it will support

BCH
Broadcast Channels; carry only downlink information and are mainly responsible for synchronisation and frequency correction (BCCH, FCCH and SCH)

BCCH
Broadcast Control Channel; the logical channel used in cellular networks to broadcast signalling and control information to all mobile phones within the network

B-CDMA
Broadband Code Division Multiple Access

B-ISDN
Broadband ISDN

BER
Bit Error Rate; the percentage of received bits in error compared to the total number of bits received

BERT
Bit Error Rate Test

Bit
A bit is the smallest unit of information technology. As bits are made up using the binary number system, all multiples of bits must be powers of two i.e. a kilobit is actually 1024 bits and a megabit 1048576 bits. Transmission speeds are given in bits per second (bit/s)

Bluetooth
A low power, short range wireless technology designed to provide a replacement for the serial cable. Operating in the 2.4GHz ISM band, Bluetooth can connect a wide range of personal, professional and domestic devices such a laptop computers and mobile phones together wirelessly.

BHCA
Busy Hour Call Attempts; the number of call attempts made during a network’s busiest hour of the day

BSC
Base Station Controller; the network entity controlling a number of Base Transceiver Stations

BSS
Base Station System/Subsystem

BTS
Base Transceiver Station; the network entity which communicates with the mobile station

CAI
Common Air Interface; a standard developed for the UK’s public CT2 networks which enabled the same handset to be used on different networks

CAMEL
Customised Application for Mobile network Enhanced Logic; an IN feature in GSM networks that enables users to carry personal services with them when roaming into other networks that support CAMEL

CSE
CAMEL Service Environment

Capacity
A measure of a cellular network’s ability to support simultaneous calls

CB
Cell Broadcast

CC
Call Control; manages call connections

CCB
Customer Care and Billing

CCCH
Common Control Channels; a group of uplink and downlink channels between the MS and the BTS (see PCH, AGCH and RACH)

CCS7
Common Channel Signalling No. 7

CDMA
Code Division Multiple Access; also known as spread spectrum, CDMA cellular systems utilise a single frequency band for all traffic, differentiating the individual transmissions by assigning them unique codes before transmission. There are a number of variants of CDMA (see W-CDMA, B-CDMA, TD-SCDMA et al)

CDMAone
The first commercial CDMA cellular system; deployed in North America and Korea; also known as IS-95

CDMA2000
A member of the IMT-2000 3G family; backwardly compatible with cdmaOne

CDMA 1X
The first generation of cdma2000; the standardisation process indicated that there would be CDMA 2X and CDMA 3X but this no longer appears likely

CDMA 1X EV-DO
A variant of CDMA 1X which delivers data only

CDPD
Cellular Digital Packet Data; a packet switched data service largely deployed in the USA. The service uses idle analogue channels to carry the packetised information.

CDPSK
Coherent Differential Phase Shift Keying

CDR
Call Detail Records; the record made within the cellular network of all details of both incoming and outgoing calls made by subscribers, The CDR is passed to the billing system for action

Cell
The area covered by a cellular base station. A cell site may sectorise its antennas to service several cells from one locationCell site
The facility housing the transmitters/receivers, the antennas and associated equipment

Cell splitting
The process of converting a single cell to multiple cells by sectorising the antennas in the cell site or constructing additional cells within a cell site

CELP
Code Excited Linear Prediction; an analogue to digital voice coding scheme, there are a number of variants used in cellular systems

CEPT
Conference of European Posts and Telecommunications. A organisation of national posts, telegraphs and telephone administrations. Until 1988, when this work was take over by ETSI, the main European body for telecommunications standardisation. CEPT established the original GSM standardisation group

CF
Call Forwarding

CI
Carrier to Interference ratio

CIBER
Cellular Intercarrier Billing Exchange Roamer Record

CID
Caller Identification

Circuit switching
A method used in telecommunications where a temporary dedicated circuit of constant bandwidth is established between two distant endpoints in a network. Mainly used for voice traffic; the opposite of packet switching

CLID
Calling Line Identification

CLIP
Calling Line Identification Presentation

CLIR
Calling Line Identification Restriction

CM
Connection Management; is used to set up, maintain and take down call connections

CMOS
Complementary Metal Oxide Substrate

Codec
A word formed by combining coder and decoder the codec is a device which encodes and decodes signals. The voice codec in a cellular network converts voice signals into and back from bit strings. In GSM networks, in addition to the standard voice codec, it is possible to implement Half Rate (HR) codecs and Enhanced Full Rate (EFR) codecs

Control signal
A signal sent to a cellular phone from a base station or vice versa which carries information essential to the call but not including the audio portion of a conversation

CPE
Customer Premises Equipment; all the equipment on the end user’s side of the network interface

CPU
Central Processing Unit

CRC
Cyclic Redundancy Check

CRM
Customer Relationship Management

CSS
Customer Support System

CT
Cordless Telephony

CT0
Zero generation cordless telephony; the earliest domestic cordless phones which used analogue technology and which had severe limitations in terms of range and security

CT1
First generation cordless telephony; Improved analogue phones with greater range and security; a number of European nations produced CT1 standards

CT2
Second generation cordless telephony; Using digital technology CT2 phones offered greater range, improved security and a wide range of new functionalities. Used in both domestic and cordless PABX deployments, CT2 was standardised as an interim ETS but was overwhelmed by DECT

CT2-CAI
Second generation cordless telephony-common air interface

CTA
Cordless Terminal Adaptor; a DECT term

CTM
Cordless Terminal Mobility

CTR
Common Technical Regulation; part of the ETSI standardisation process

CUG
Closed User Group

D/A
Digital to Analogue conversion

DAC
Digital to Analogue Convertor

DAMA
Demand Assigned Multiple Access

D-AMPS
Digital AMPS, a US wireless standard also known as IS-136

DAN
DECT Access Node

DCA
Dynamic Channel Assignment

DCCH
Dedicated Control Channels; responsible for roaming, handovers, encryption etc. (See SDCCH, SACCH and FACCH)

DCE
Data Communications Equipment

DCH
Data Clearing House

DCPSK
Differentially Coherent Phase Shift Keying

DCS1800
Digital Cellular System at 1800MHz, now known as GSM1800

DECT
Digitally Enhanced Cordless Telecommunications system, a second generation digital cordless technology standardised by ETSI

DEPSK[/b][/color]
Differential Encoded Phase Shift Keying

DES[/b][/color]
Digital Encryption Standard

DFSK
Double Frequency Shift Keying

Digital
a method of representing information as numbers with discrete values; usually expressed as a sequence of bits

DPCM
Differential Pulse Code Modulation

DPSK
Digital Phase Shift Keying

DQPSK
Digital Quadrature Phase Shift Keying

DS-CDMA
Direct Sequence CDMA

DSP
Digital Signal Processing

DSRR
Digital Short Range Radio; a UK standard for a low power, short range radio system designed for small voice and data networks

DTE
Data Terminal Equipment

DTMF
Dual Tone MultiFrequency; better know as Touch Tone. The tones generated by touching the keys on the phone are used for a variety of purposes including voice mail systems and voice messaging

DTX
Discontinuous Transmission

Dual Band
The capability of GSM infrastructure elements and handsets to work across both the 900MHz and 1800MHz bands. The capability to seamlessly handover between the two bands offers operators major capacity gains

DB
Dummy Burst; transmitted as a filler in unused timeslots of the carrier

Duplex
The wireless technique where one frequency band is used for traffic from the network to the subscriber (the downlink) and another, widely separated, band is used for traffic from the subscriber to the network (the uplink)

EDGE
Enhanced Data rates for GSM Evolution; effectively the final stage in the evolution of the GSM standard, EDGE uses a new modulation schema to enable theoretical data speeds of up to 384kbit/s within the existing GSM spectrum. An alternative upgrade path towards 3G services for operators, such as those in the USA, without access to new spectrum. Also known as Enhanced GPRS (E-GPRS)

EEPROM
Electrically Erasable Programmable Read Only Memory

EFR
Enhanced Full Rate; a alternative voice codec that provides improved voice quality in a GSM network (see codec)

EFT
Electronic Funds Transfer

EGSM
Extended (frequency range) GSM

EIR
Equipment Identity Register; a database that contains a list of all valid mobile stations within a network based on their IMEI

EIRP
Effective Isotropic Radiated Power

EPOC
The mobile phone operating system developed by Symbian. Derived from epoch-the beginning of an era-EPOC is a 32-bit operating environment which comprises a suite of applications, customisable user interfaces, connectivity options and a range of development tools

EPROM
Erasable Programmable Read Only Memory

Erlang
A dimensionless unit of average traffic density in a telecommunications network

ERMES
Enhanced Radio Messaging System; a paging technology developed by ETSI which was intended to allow users to roam throughout Europe. Adopted by a number of European and Middle Eastern countries, ERMES, like paging in general, was overtaken by the ubiquity of GSM

ERO
European Radiocommunications Office

ERP
Effective Radiated Power

ESMR
Enhanced Special Mobile Radio; a US PMR variant (see SMR)

ESN
Electronic Serial Number; a 32-bit number that uniquely identifies a mobile phone

ESPRIT
European Strategic Programme for Research and Development in Information Technology

ETACS
Extended TACS; the extension of TACS by the addition of new frequencies

ETS
European Telecommunications Standard

ETSI
European Telecommunications Standards Institute: The European group responsible for defining telecommunications standards

FACCH
Fast Associated Control Channel; similar to the SDCCH but used in parallel for operation of the TCH. If the data rate of the SACCH is insufficient borrowing mode is used

FB
Frequency Correction Burst; used for frequency synchronisation of the mobile

FCC
Federal Communications Commission; the US regulatory body for telecommunications

FCCH
Frequency Correction Channel; downlink only, correction of MS frequencies, transmission of frequency standard to MS etc.

FDD
Frequency Division Duplex; a radio technique which uses paired spectrum; UMTS has an FDD element

FDMA
Frequency Division Multiple Access-a transmission technique where the assigned frequency band for a network is divided into sub-bands which are allocated to a subscriber for the duration of their calls

FEC
Forward Error Correction

FH
Frequency Hopping

FH-CDMA
Frequency Hopping CDMA

FMC
Fixed Mobile Convergence

FMI
Fixed Mobile Integration

FPLMTS
Future Public Land Mobile Telecommunications System, the original title of the ITU’s third generation concept now known as IMT-2000

FRA
Fixed Radio Access; see WLL

FSDPSK
Filtered Symmetric Differential Phase Shift Keying

FSK
Frequency Shift Keying; a method of using frequency modulation to send digital information

FSOQ
Frequency Shift Offset Quadrature Modulation

FSS
Fixed Satellite ServiceGb
The interface between the PCU and the SGSN in a GSM/GPRS network

Gc
The interface between the GGSN and the HLR in a GSM/GPRS network

Gd
The interface between the SGSN and the SMSC in a GSM/GPRS network

Gf
The interface between the SGSN and the EIR in a GSM/GPRS network

Gi
The interface between the GGSN and the Internet in a GPRS network

Gn
The interface between the GGSN and the SGSN in a GPRS network

Gp
The interfaces between the GGSN/SGSN and the Border Gateway in a GPRS network

Gr
The interface between the SGSN and the HLR in a GPRS network

Gs
The interface between the SGSN and the MSC in a GSM/GPRS network

GAIT
GSM/ANSI 136 Interoperability Committee

GAP
Generic Access Profile; a DECT term

Gbit/s
A unit of data transmission rate equal to one billion bits per second

GMSC
Gateway Mobile Services Switching Centre; the gateway between two networks

GCF
Global Certification Forum

Geostationary
Refers to a satellite in equatorial orbit above the earth which appears from the surface to be stationary

GERAN
GSM-EDGE Radio Access Network; the name for the evolution of GSM towards 3G based on EDGE

GGRF
GSM Global Roaming Forum

GGSN
Gateway GPRS Support Node; the gateway between a cellular network and a IP network.

GHz
A unit of frequency equal to one billion Hertz per second

GMPCS
Global Mobile Personal Communications by Satellite

GMSK
Gaussian filtered Minimum Shift Keying; a refinement of FSK which minimises adjacent channel interference

GPRS
General Packet Radio Service; standardised as part of GSM Phase 2+, GPRS represents the first implementation of packet switching within GSM, which is a circuit switched technology. GPRS offers theoretical data speeds of up to 115kbit/s using multislot techniques. GPRS is an essential precursor for 3G as it introduces the packet switched core required for UMTS

GPS
Global Positioning System; a location system based on a constellation of US Department of Defence satellites. Depending on the number of satellites visible to the user can provide accuracies down to tens of metres. Now being incorporated as a key feature in an increasing number of handsets

GRX
GPRS Roaming Exchange

GSM
Global System for Mobile communications, the second generation digital technology originally developed for Europe but which now has in excess of 71 per cent of the world market. Initially developed for operation in the 900MHz band and subsequently modified for the 850, 1800 and 1900MHz bands. GSM originally stood for Groupe Speciale Mobile, the CEPT committee which began the GSM standardisation process

GSM MoU
The GSM Memorandum of Understanding, an agreement signed between all the major European operators to work together to promote GSM. The precursor of the GSM Association

GSM-R
GSM-Railway, A variant of GSM designed to meet the special communications needs of international train operators

Handoff
The transfer of control of a cellular phone call in progress from one cell to another, without any discontinuity

Hands-free
The operation of a cellular phone without using the handset; usually installed in vehicles.

HCS
Hierarchical Cell Structure; the architecture of a multi-layered cellular network where subscribers are handed over from the macro to the micro to the pico layer depending on the current network capacity and the needs of the subscriber

HDLC
High level Data Link Control

HIPERLAN
High Performance Radio Local Access Network; a wireless local area network being standardised by ETSI (Also HIPERLAN2)

HLR
Home Location Register; the database within a GSM network which stores all the subscriber data. An important element in the roaming process

HSCSD
High Speed Circuit Switched Data; a special mode in GSM networks which provides higher data throughput By cocatenating a number of timeslots, each delivering 14.4kbit/s, much higher data speeds can be achieved

HSPSD
High Speed Packet Switched DataIub
The interface between the Node B and the RNC in a UMTS network

Iur
The interface between RNCs in a UMTS network

Iups
The connection between the RNC and the packet switched network in a GSM/GPRS/UMTS network

Iucs
The connection between the RNC and the circuit switched network in a GSM/GPRS/
UMTS network

I-ETS
Interim European Telecommunications Standard

I-mode
A service developed by Japanese operator NTT DoCoMo, I-mode delivers a huge range of services to subscribers and has proved enormously popular with some 30 million regular users. The revenue sharing model used for I-mode is being adopted by other operators as the basis for the new services enabled by GPRS and 3G

IMEI
International Mobile Equipment Identity

IMSI
International Mobile Subscriber Identity; an internal subscriber identity used only by the network

IMT-2000
The family of third generation technologies approved by the ITU. There are five members of the family: IMT-DS, a direct sequence WCDMA FDD solution IMT-TC, a WCDMA TDD solution IMT-MC, a multicarrier solution developed from cdma2000 IMT-SC, a single carrier solution developed from IS-136/UWC-136 IMT-FT, a TDMA/TDD solution derived from DECT

IN
Intelligent Network

INAP
Intelligent Network Application Part

Internet
A loose confederation of autonomous databases and networks. Originally developed for academic use the Internet is now a global structure of millions of sites accessible by anyone

Intranet
A private network which utilises the same techniques as the Internet but is accessible only by authorised users

IP
Internet Protocol

IPR
Intellectual Property Rights

IPv6
The next generation of IP addressing designed to replace the current system IPv4 which uses a 32 bit address code which limits the number of possible addresses. IPv6 uses a 128 bit code ensuring that the possible number of IP addresses will be virtually limitless

IrDA
Infra red Data Association

Iridium
A low earth orbit satellite communications system developed initially by Motorola.

IS-54
The first evolution in the USA from analogue to digital technology. Used a hybrid of analogue and digital technology, superseded by IS-136

IS-95
Cellular standard know also as cdmaOne

IS-136
Cellular standard also known as TDMA or D-AMPS

ISDN
Integrated Services Digital Network

ISO
International Standards Organisation

ISP
Internet Service Provider

ITU
International Telecommunications Union

ITU-R
ITU Telecommunications Radio Sector

ITU-T
ITU Telecommunications Standardisation Sector

IWF
Interworking Function

Java
A programming language developed by Sun Microsystems Java is characterised by the fact that programs written in Java do not rely on an operating system

JPEG
Joint Photographic Experts Group

LAP
Link Access Protocol

LEO
Low Earth Orbit; refers to satellites which orbit the Earth at around 1,000 kilometres

LMSS
Land Mobile Satellite Service

LOS
Line of Sight

MAC
Media Access Control; the lower sublayer of the OSI system

MAP
Mobile Application Part

Mbit/s
Megabit: a unit of data transmission speed equal to one million bits per second

MHz
Megahertz; a unit of frequency equal to one million Hertz

MCPA
Multi Carrier Power Amplifier

MeXe
Mobile Execution Environment; likely to be based on Java, MeXe enables WAP-enabled devices to offer a wider range of features with greater security and flexibility, as well as greater control of telephony features

MFSK
Multiple Frequency Shift Keying

MMI
Man Machine Interface

MMS
Multimedia Messaging Service; an evolution of SMS, MMS goes beyond text messaging offering various kinds of multimedia content including images, audio and video clips

MMSK
Modified Minimum Shift Keying

MNO
Mobile Network Operator

Modulation
The process of imposing an information signal on a carrier. This can be done by changing the amplitude (AM), the frequency (FM) or the phase, or any combination of these

MoU
Memorandum of Understanding-
see GSM MoU

MPEG
Motion Picture Experts Group; MPEG4 is a technology for compressing voice and video so that the information can be transmitted over normally difficult links such as mobile radio

MS
Mobile Station

MSC
Mobile Switching Centre; the switching centre of a mobile phone network, the MSC has interfaces to the BSCs, HLR, VLR and other MSCs

MSISDN
Mobile Station International ISDN Number

MSK
Minimum Shift Keying; Another term for FFSK

Multiplexing
A telecommunications technique where several channels can be combined to share the same transmission medium. The most common forms are Time Division Multiplexing (TDM) and Frequency Division Multiplexing (FDM)

MVPN
Mobile Virtual Private Network

N-AMPS
Narrowband AMPS

NB
Normal Burst; used to carry traffic and control channels except RACH

NET
Norme Europeenne de Telecommunications

NMT
Nordic Mobile Telephone system; an analogue cellular technology deployed in the Nordic countries in the late 1970’s; variations were also deployed in the Benelux countries and in Russia. NMT operated in the 450 and 900MHz bands and was the first technology to offer international roaming, albeit only in the Nordic countries

Node B
The element in a UMTS network which interfaces with the mobile station, analogous to a BTS in a GSM network

OTA
Over the air activation (of services and tariff changes)

O&M
Operations and Maintenance

OMC
Operations and Maintenance Centre

OMC-R
The radio OMC

OMC-S
The switching OMC

OSI
Open Systems Interconnection; a seven layer model for protocols defined by ISO

muthumadhu · Joined: 09 Jun 2009 Posts: 7

Hai,
Your definitions are very useful.You done the great work