The following is a compiled list of mobile terms and acronyms from the GSM Association

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

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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

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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

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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

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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

Differential Encoded Phase Shift Keying

DES

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)

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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

ETSI

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

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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

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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

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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

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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

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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

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LAN

Local Area Network

LANS

Local Area Network Services

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

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MAC

Media Access Control; the lower sublayer of the OSI system

MAN

Metropolitan Area Network

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

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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

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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

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PACS

Personal Access Communication System; a digital cordless technology
developed initially by Bell Labs in the US, PACS was designed to
compete with DECT

Packet switching

A communication system wherein the information is transmitted in
packets of a set size. These packets have address headers and find
their way to their destination by the most efficient route through the
network. Compared to circuit switching where a connection is occupied
until the traffic exchange is completed, packet switching offers
considerable efficiencies as connections can be used by a number of
users simultaneously

PAMR

Public Access Mobile Radio; Commercial service using trunking
techniques in which multiple groups of users can set up their own
closed systems within a shared public network

PAP

Public Access Profile; a DECT term

PCH

Paging Channel; downlink only, the MS is informed of incoming calls by
the BTS via the PCH

PCM

Pulse Code Modulation; the standard digital voice format at 64kbit/s

PCMCIA

Personal Computer Memory Card Interface Association the body
responsible for defining the standards and formats for memory expansion
cards for laptop computers and PDAs. Now extended to cover cards for
mobile phones

PCN

Personal Communications Network; a designation initially used in the UK
to refer to networks operating in the 1800MHz band (see also DCS1800).
No longer in use

PCS 1900

Personal Communications Systems 1900MHz; the terminology used in the US
to describe the new digital networks being deployed in the 1900MHz
band; rarely used today

PCU

Packet Control Unit; an element in a GPRS/UMTS network

PDA

Personal Digital Assistant

PDC

Personal Digital Communications; a digital cellular technology
developed and deployed uniquely in Japan. A TDMA technology, PDC is
incompatible with any other digital cellular standard

PEDC

Pan European Digital Communications; A designation occasionally used in
the early 1990.s to describe GSM. No longer in use

Penetration 

The percentage of the total population which owns a mobile phone

PHS / PHP

Personal HandyPhone System/Phone; a digital cordless technology
developed in Japan which achieved great success. Deployed by NTT DoCoMo
and other Japanese operators PHS offered two-way communications, data
services and Internet access and eventually won some 28 million
customers. Now in decline as cellular.s wide area capabilities offer
better service

PIN

Personal Identifier Number

PKI

Public Key Infrastructure

PLMN

Public Land Mobile Network; any cellular operator.s network

PMR

Private Mobile Radiocommunications; two-way radio technology widely
used for despatch and delivery services, taxi companies and the like.
See TETRA

POCSAG

Post Office Code Standardisation Group; a now defunct industry grouping
which standardised pager addressing systems

PoP

Points of Presence; a method of measuring the value of a cellular
licence; the approximate number of potential customers within a
geographical area

POTS

Plain Old Telephone Service

PROM

Programmable Read Only Memory

PSK

Phase Shift Keying

PSRCP

Public Safety Radio Communications Project; an initiative by the UK
Government to standardise all emergency services communications on to a
single digital technology (see TETRA)

PSDN

Public Switched Data Network

PSPDN

Public Switched Packet Data Network

PSTN

Public Switched Telephone Network

PSU

Power Supply Unit

PTO

Public Telecommunication Operator

PTT

Posts, Telephone and Telegraph Administration

PTT

Push-to-Talk; a feature of PMR systems

PWT

Personal Wireless Telecommunications; a variant of DECT developed for
use in the USA

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QAM

Quadrature Amplitude Modulation

QAPSK

Quadrature Amplitude Phase Shift Keying

QCELP

Quadrature Code Excited Linear Prediction

QoS

Quality of Service; a broad term to describe the performance attributes
of an end-to-end connection

QPSK

Quadrature Phase Shift Keying

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RACE

Research in Advanced Communications in Europe

RACH

Random Access Channel; uplink only, allows the MS to request an SDCCH
in response to a page or for a call

RAM

Random Access Memory

RFP

Radio Fixed Part; equivalent to a base station in a DECT system

RCC

Radio Common Carrier

RELP

Regular pulse Excitation Linear Prediction coding

Reuse

The assignment of frequencies or channels to cells so that adjoining
cells do not use the same frequencies and cause interference whereas
more distant cells can use the same frequencies. Reuse expands the
capacity of a cellular network by enabling the use of the same channels
throughout the network

RP 

Radio Part

RNC

Radio Network Controller; the element which controls the Node Bs within
a UMTS network. It is roughly analogous to a BSC in a GSM network

Roaming

A service unique to GSM which enables a subscriber to make and receive
calls when outside the service area of his home network e.g. when
travelling abroad

Router 

A device which forwards information in a network on a connectionless
basis

RRM

Radio Resource Management, part of the UMTS infrastructure

RT

Remote Terminal

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SACCH

Slow Associated Control Channel; transmits continuous measurements in
parallel with operation of TCH or SDCCH; needed for handover decisions

SAR

Specific Absorption Rate

SB

Synchronisation Burst; used for time synchronisation of the mobile

S-CDMA

Synchronous CDMA (see CDMA)

SCH

Synchronisation Channel; downlink only frame synchronisation and
identification of base station

SCP

Switching/Service Control Point

SDCCH

Stand-alone Dedicated Control Channel; communications channel between
the MS and the BTS. Used for signalling during call set-up before a TCH
is allocated

SDLC

Synchronous Data Link Control

SDMA

Spatial Division Multiple Access

SGSN

Serving GPRS Support Node; the gateway between the RNC and the core
network in a GPRS/UMTS network

SIM

Subscriber Identity Module; A smart card containing the telephone
number of the subscriber, encoded network identification details, the
PIN and other user data such as the phone book. A user.s SIM card can
be moved from phone to phone as it contains all the key information
required to activate the phone

SoHo

Small Office/Home Office

Streaming

An Internet derived expression for the one-way transmission of video
and audio content

STK

SIM ToolKit: specified within the GSM standard, this allows operators
to add additional functions to the phone menu in order to provide new
services such as mobile banking or email

SMR

Specialised Mobile Radio; the US term for private mobile radio (See PMR)

SMS

Short Message Service; a text message service which enables users to
send short messages (160 characters) to other users. A very popular
service, particularly amongst young people, with 400 billion SMS
messages sent worldwide in 2002

SMSC

SMS Centre-the network entity which switches SMS traffic

SMSCB

SMS Cell Broadcast

SMS-MO

SMS Mobile Originated

SMS-MT

SMS Mobile Terminated

SMS-PP

SMS Point to Point

SP

Service Provider

SQAM

Staggered Quadrature Amplitude Modulation

SQPSK

Staggered Quadrature Phase Shift Keying

SS

Supplementary Service Support; handles special services

SS7

Signalling System Number 7 (See CCS7)

SSP

Service Switching Point

STM

Synchronous Transfer Mode

Symbian

A company created by Psion, Nokia, Ericsson and Motorola in 1998 with
the aim of developing and standardising an operating system which
enable mobile phones from different manufacturers to exchange
information

The operating system is known as EPOC. Matsushita has subsequently
joined Symbian

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TACS

Total Access Communications System (an AMPS variant deployed in a
number of countries principally the UK)

TAP

Transferred Account Procedure; the essential charging methodology for
international GSM roaming. There have been four TAP standards, TAP1,
TAP2, TAP2+ and TAP3. The latter offers variable record length and is
sufficiently flexible to support all future requirements arising from
the move to 3G

TBR

Technical Basis for Regulation (part of the ETSI standardisation
process)

TCH

Traffic Channel

TD-CDMA

Time Division CDMA

TD-SCDMA

Time Division-Synchronous CDMA; a CDMA variant developed by Chinese
vendors which is claimed to offer high data rates and greater coverage

TDD

Time Division Duplex; a radio technology for use in unpaired spectrum.
WCDMA/UMTS includes a band for TDD mode usage and both PHS and DECT use
this technology

TDMA

Time Division Multiple Access; a technique for multiplexing multiple
users onto a single channel on a single carrier by splitting the
carrier into time slots and allocating these on a as-needed basis

Telematics

A wireless communications system designed for the collection and
dissemination of information, particularly refers to vehicle-based
electronic systems, vehicle tracking and positioning, on-line vehicle
navigation and information systems and emergency assistance

TETRA

Terrestrial Trunked Radio; a European developed digital private mobile
radio technology which is now being extensively deployed worldwide

Tetrapol

A competitive digital PMR technology to TETRA developed by French
vendors

TFTS

Terrestrial Flight Telephone System

Timeslot

A frame within a TDMA schema; has a time interval of 576 microseconds.
Physical content of a timeslot is known as a burst. Five different
burst types exist, they are distinguished by different TDMA frame
divisions (see NB, FB, SB, AB and DB)

TIPHON

Telecommunications and Internet Protocol Harmonisation over Networks;
an ETSI project designed to support the market for voice communications
and voice band communications. In particular TIPHON will ensure that
users on IP-based networks can communicate with those on circuit
switched networks

TMN

Telecommunications Management Network

TMSI

Temporary Mobile Subscriber Identity; covers the IMSI to prevent
over-the-air interception and tracing

TRAU

Transcoder Rate Adapter Unit; the transport unit for a 16kbit/s traffic
channel on the A-bis interface

Tri-band

Refers to a mobile phone able to operate on the three internationally
designated GSM frequencies- 900, 1800 and 1900MHz

TrueSync

A technology which enables the optimal synchronisation of calendars,
address books, action lists and memoranda. It enables multi-point,
one-step synchronisation of wireless and wireline devices, desktop
computers and server-based applications and services

TRX

Transmitter/receiver (transceiver)

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UI

User Interface

Um

The air interface between the BTS and the MS in a GSM network

Uu

The air interface between the Node B and the MS in a UMTS network.

UMTS

Universal Mobile Telecommunications System; the European entrant for
3G; now subsumed into the IMT-2000 family as the WCDMA technology. 

UPN

Universal Personal Number

UPT

Universal Personal Telecommunications

URL

Uniform Resource Locator; the addressing system of the Internet

USO

Universal Service Obligation

UTRA

Universal Terrestrial Radio Access; the air interface component of
WCDMA. 

UTRAN

Universal Terrestrial Radio Access Network; the UMTS radio access
network comprising the RNC, Node B and the air interface

USIM

Universal Subscriber Identity Module; the 3G equivalent of the GSM SIM

UWB

Ultra Wide Band

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VAS

Value Added Services

VBR

Variable Bit Rate

VHE

Virtual Home Environment

VLR

Visitor Location Register

Vocoder

Voice coder

VoIP

Voice over Internet Protocol

VPN

Virtual Private Network

VSAT

Very Small Aperture Terminal

VSELP

Vector Sum Excited Linear Prediction

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WAP

Wireless Application Protocol; a de facto standard for enabling mobile
phones to access the Internet and advanced services. Users can access
websites and pages which have been converted by the use of WML into
stripped-down versions of the original more suitable for the limited
display capabilities of mobile phones

WARC

World Administration Radio Conference; an ITU conference held at
regular intervals to determine the allocation of spectrum for various
services

WCDMA 

Wideband CDMA; the technology created from a fusion of proposals to act
as the European entrant for the ITU IMT-2000 family

WLL

Wireless Local Loop; a technique for providing telephony and low speed
data services to fixed customers using wireless. Regarded as having
considerably potential for rapidly addressing the telecommunications
gap in developing countries. A number of different WLL solutions have
been marketed based on cellular and cordless technologies

WLAN

Wireless Local Area Network; a short range radio network normally
deployed in traffic hotspots such as airport lounges, hotels and
restaurants. WLAN enables suitably equipped users to access the fixed
network wirelessly, providing high speed access (up to 11Mbit/s
download) to distant servers. The key WLAN technologies are the
IEEE802.11 family and ETSI HIPERLAN/2

WML

Wireless Markup Language; a markup language developed specifically for
wireless applications. WML is based on XML

WQAM

Weighted Quadrature Amplitude Modulation

WWW

World Wide Web

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XML

eXtended Markup Language

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