Search here for communications (and some other) related acronyms and terms.

 

 

Link to the Glossary A - D

Link to the Glossary E - K

Link to the Glossary L - R

Link to the Glossary S - Z

 

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Acronyms A - D

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AC
Alternating Current

ACTS
Advanced Communications Technologies and Services

ADR
Alternative Dispute Resolution

ADPCM
Adaptive Differential Pulse Code Modulation. An encoding technique, similar to PCM, for digitising analogue voice signals at a reduced rate of 32 kBit/s

 

AM
Amplitude Modulation. A method for impressing information on a carrier by varying its amplitude

 

AMPS
Advance Mobile Phone System - cellular system standard used in the USA

 

API
Application Programmer's Interface

 

ATM
Asynchronous Transfer Mode

 

ATDMA
Advanced/Adaptive Time Division Multiple Access Project

 

ARQ
Automatic Repeat reQuest. A method of error connection whereby the receiver asks the transmitter to resend a block or frame found to contain errors

 

ASCII
Pronounced "asky". The American Standard Code for Information Interchange. The US version of the ISO 7-bit data code, usually transmitted in 8-bit characters, the additional bit being an (odd or even) parity bit

 

AVL
Automatic Vehicle Location - various land-mobile and satellite systems are used to establish the location of a vehicle or person

 

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BANDWIDTH
The size of the frequency range a communication channel can carry

 

BASE STATION
The transmitter/receiver and associated equipment at a fixed location

 

BAUD
Unit of signalling speed - expressed as the number of discrete condition or signal events per second

 

BCS
Base Station Controller

 

BER
Bit Error Rate

 

BFWA
Broadband Fixed Wireless Access

 

BIT
Binary digIT - a unit of information (Zero or One)

 

BPM
Business Process Management

 

BPS
Bits Per Second

 

BRAN
Broadband Access Network

 

BYTE
Eight BITs forming a unit of data (usually one character - a letter, number or symbol)

 

 
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CAI
Common Air Interface - a standard so that terminals can be used on any networks

 

CARRIER
An electromagnetic signal which is used as a medium for an information channel. The carrier's fundamental property such as frequency or amplitude is "modulated" (changed in some systematic way) by the information signal which is being transported)

 

CBS
Common Base Station - a shared wide-area repeater base station

 

CCIR
Committee Consultatif International Radio Communication

 

CCITT
The International Telephony and Telegraphy Consultative Committee, which is part of the International Telecommunications Union, an agency of the United Nations. The principal members of CCITT are the world's public communication authorities (PTO's)

 

CDLC
Cellular Data Link Control. A Proprietary protocol for modems which are to be used over a radio link. CDLC employs elaborate error correcting schemes to compensate for the high error rates of radio links

 

CDM

Credit and Debt Management 

 

CDMA
Code Division Multiple Access - Spread Spectrum, where users share the same time and spectrum and are separated by different unique coding.

 

CELLULAR
A technique used in mobile radio telephony to use the same radio spectrum many times in one network. Lower power radio transmitters are used to cover a limited area or "cell" such that the frequencies in use can be re-used in other parts of the network

 

CEPT
European Conference of Postal & Telecommunications Administrations. CEPT is an association of European PTTs (Postal Telephone and Telegraph Administrations) and network operators from 18 countries

 

CLI
Calling Line Identification

 

COMMUNITY REPEATER
A repeater base station which is shared by several separate groups of users

 

CORDLESS
In the world of mobile communications, a voice communications system in which the user is not continuously moving and which is limited in range.

 

CPE
Customer Premises Equipment

 

CPS
Carrier Pre-Selection

 

CSMA/CD
Carrier Sense Multiple Access/Collision Detection; one of the major classes of media access technology,

used in LANs, particularly Ethernet. It is specified in OSI Standard ISO 8802/3, based upon the work of IEEE committee 802.3

 

CT1
Cordless Telephone (1st Generation) in use only in the UK - operates in the HF / low VHF bands using analogue technology

 

CT2
Cordless Telephone (2nd Generation) - a digital standard for cordless telephones

 

CTCSS
Continuous Tone Controlled Signalling System (or Sub-audio Squelch)

 

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dB
Decibel - a measure of the change or difference in levels between two signals

 

DC
Direct Current

 

DCS - Digital Controlled Squelch.

A digital variant of the CTCSS signalling. Transmitted as a low speed digital signal alongside voice.

 

DCS1800
ETSI standard based on GSM for cellular networks in the 1.8 GH\z to 2 GHz band. Adopted for UK PCN

 

DECT
Digital European Cordless Telephone. A pan-European standard for cordless systems designed to operate in a wide range of applications

 

DIGITAL
Used to describe a signal which changes state in discrete increments

 

DTE
Data Terminal Equipment

 

DTMF
Dual Tone Multi-Frequency

 

DUPLEX
Simultaneous two-way sending and receiving

 

 

Acronyms E - K

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EDI
Electronic Data Interchange

 

EEA
The European Association representing the Electronics, Telecommunications and Business Equipment Industries

 

EIA
The US Electronic Industries Association is an Accredited Standards Committee of ANSI (American National Standards Institute) responsible for some Physical Layer standards e.g. RS 232

 

EMC
Electromagnetic Compatibility

 

EPIRB
Emergency Position Indicating Radio Beacon

 

ERC
European Radiocommunications Committee - the main CEPT committee looking after radio matters

 

ERMES
European Radio MEssaging System - an ETSI digital paging standard that never took off

 

ERO
European Radio Office - website
permanent secretariat within ERC

 

ERP
Effective Radiated Power. The product of the power supplied to an antenna and its gain relative to a half wave dipole in a given direction

 

E-TACS
Extended Total Access Communications System. The extension to TACS by the addition of further channels

 

ETHERNET
A type of local area network based upon CSMA/CD technology - 10MB/s Ethernet was a joint development by Digital Equipment Corporation, Intel and Xerox

 

ETSI
European Telecommunications Standards Institute - website
an autonomous body formed in 1988 by the European Commission and CEPT to undertake standards writing activities. The membership of ETSI is open - currently 135 organisations including national administrations, public network operators, manufacturers, users and research bodies

 

EU
European Union

 

 

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FDD
Frequency Division Duplex

 

FDMA
Frequency Division Multiple Access. The process of dividing up the available spectrum into channels of different frequencies

 

FEC
Forward Error Correction. A technique for error correction which does not require the retransmission of data from the transmitter

 

FFSK
Fast Frequency Shift Key. Sub carrier modulated signalling system operating at 1,200 and 1,800 band that can be used for data transmission

 

FM
Frequency Modulation - variation of the frequency of a carrier wave in response to a modulating signal

 

FSK
Frequency Shift Keying - sub-carrier modulated signalling system that can be used for data transmission

 

FSS
Fixed Satellite Service

 

FWA
Fixed Wireless Access

 

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GHz
Gigahertz

 

GMSK
Gaussian Minimum Shift Keying. Another refinement of PSK which minimises adjacent channel interference

 

GPRS
General Packet Radio Service

 

GROUNDPLANE
The horizontal surface required for propagation from an antenna. Usually the earth's surface

 

GSM
Global System for Mobile Communications - originally a European cellular standard from ETSI now used world-wide

 

HDLC
High Level Data Link Control. A CCITT standard for the frame structure and protocol for the exchange of data at the Data Link level

 

HF
High Frequency - (3 to 30 MHz)

 

HYPERLAN
High Performance Radio Local Area Networks

 

Hz
Hertz - A frequency of one cycle per second
 

IA5
International Alphabet no. 5. The ISO equivalent of ASCII

 

IEC
International Electro technical Commission

 

IP
Internet Protocol

 

ISDN

Integrated Services Digital Network. An internationally agreed public network offering switched end-to-end digital services for voice and data

 

ISM
Industrial Scientific and Medical - the use of radio for non-communication purposes such as microwave heating and radiography

 

ITU
International Telecommunications Union

 

JPEG
Joint Photographic Experts Group

 

KHz
Kilohertz - 1000 cycles per second

 

 

Acronyms L - R

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LAN
Local Area Network. A network which spans a limited geographical area (usually within one building or site) and interconnects a variety of computers and terminals

 

LF
Low Frequency (30-300kHz)

 

LLU
Local Loop Unbundling - More

 

LPC
Linear Predictive Coding. A speech digitising technique which extracts features from the speech pattern and sends the features to the receiving end where the original speech is synthesized. Used because lower bit rates for good quality speech transmission can be achieved relative to conventional digitising such as PCM

 

LPD
Low Power Devices - generally small transmit (a few 100mw or less) and/or receive modules used for telemetry control

 

LSB
Lower Side Band (see SSB)

 

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MF
Medium Frequency (300kHz-3MHz)

 

MHz
Megahertz - 1,000,000 cycles per second

 

MSK
Minimum Shift Keying. Another term for FFSK

 

MOBILE
In the general sense, describes a system in which a radio communications link is maintained whilst on the move e.g. a user can continue a conversation in a moving vehicle train. Applied to cellular subscriber equipment refers to permanently vehicle-mounted equipment as distinct from hand-portables

 

MODEM
A contraction of the term "modulation-demodulator". A modem converts the serial digital data from a transmitting terminal into a form suitable for transmission over the analogue telephone channel. A second unit reconverts this signal to serial digital data for acceptance by the receiving terminal

 

MODULATION
The process of impressing information on a carrier usually by varying either its amplitude or frequency

 

MoU
Memorandum of Understanding, a document that details agreements between parties with a common interest

 

MULTIPLEXING
In communication systems, the function of transporting more than one stream of data over a single circuit (real or virtual) apparently simultaneously. Multiplexing can be either in the frequency domain (FDM) or the time domain (TDM)

 

MUTING
The process by which the audio circuits of a receiver are turned off in the absence of a carrier on the appropriate frequency. Used in conjunction with CTCSS and Selcal to achieve selective reception by a mobile or group of mobiles

 

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NGN
Non Geographic Numbers

 

NMT
Nordic Mobile Telephone - cellular system standard evolved by the Nordic countries

 

OEM
Original Equipment Manufacturer

 

OFCOM
Office of Communications

 

PABX
Private Automatic Branch Exchange

 

PAMR
Public Access Mobile Radio - A PMR Two-Way Radio type of service provided by a third-party Network Operator

 

PBX
Private Branch Exchange

 

PBR
Private Business Radio (see PMR)

 

PCM
Pulse Code Modulation. An encoding technique for digitising analogue voice signals

 

PCN
Personal Communications Network. Used generically to describe a mobile communications system for use with a mass market low cost hand-portable

 

PCS
Personal Communications System. A universal mobile personal telecommunications system usually involving a base station, dispatch centre and vehicle-mounted mobile transceivers

 

PDN
Public Data Network

 

PMR
Professional / Private / Personal Mobile Radio - Two Way Radio - Generally recognised as the term covering communications other than mobile telephones

 

POCSAG
Post Office Code Standardisation Advisory Group. Industry standard coding scheme for addressing pagers

 

PSTN
Public Switched Telephone Network

 

PTNC
Public Telecommunications Network Operator

 

PTT
Press To Talk - often used to describe the transmit button on a PMR two-way radio

 

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Q
no entries

 

RA
Radiocommunications Agency - the spectrum regulator prior to OFCOM

 

RF
Radio Frequency. Carrier frequencies used for radio communications

 

RFID
Radio Frequency IDentification - tagging and tracking items

 

RIS
Radio Investigation Service - part of Ofcom dealing with keeping the spectrum 'clean' and free from interference

 

RLAN
Radio Local Area Network

 

RoHS
Restriction of the Use of Certain Hazardous Substances

 

RPC1
Radiopaging Code No. 1. The CCIR equivalent of POCSAG

 

RTPI
Real Time Passenger Information

 

RTTE
Radio and Telecommunication Terminal Equipment - A European Directive enabling manufacturers to 'self-certify' their product for technical compliance and to place them on the market

 

RX

Receiver

 

 

 

Acronyms S - Z

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SELCALL
Selective Calling. In PMR systems, a method of sending control information by means a sequence of, usually, five tones

 

SIDEBANDS
The radiation of frequencies above and below the carrier frequency which result from modulation of a carrier

 

SHF
Super High Frequency - above 30 GHz

 

SIM
Subscriber Identity Module

 

SIMPLEX
A one-way communications channel

 

SLA
Service Level Agreement

 

SMO
Spectrum Management Organisation

 

SPC
Stored Program Control. Generally the application of computer techniques to the control of private or public telephone exchanges

 

SSB
Single Side Band. A modulation method used mainly on HF (Short Wave)

 

STS
Sequential Tone Signalling

 

STH
Short Term Hire

 

 

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TACS
Total Access Communication system - analogue cellular system standard used in the UK and derived from AMPS

 

TCBS
Trunked Common Base Station

 

TCVR
Transceiver - a combined TX and RX

 

TETRA
TErrestrial Trunked RAdio - originally a European digital trunked radio ETSI standard

 

TDD
Time Division Duplex. A technique for achieving full duplex on a half duplex channel by using time

division multiplexing

 

TDMA
Time Division Multiple Access

 

TOKEN BUS
A LAN technology specified in ISO 8802/4 and IEEE 802/4

 

TOKEN RING
A LAN technology specified in ISO 8802/5 and IEEE 802/5 primarily supported by IBM. Employs a system of token passing for media access

 

TX
Transmitter

 

 

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UHF
Ultra-High Frequency. Used to describe radio signals in the 300 MHz to 3GHz frequency band

 

UMTS
Universal Mobile Telecommunications Service. A pan-European research project aimed at unifying all the existing mobile networks into a single standardised environment

 

USB
Universal Serial Bus or alternatively Upper Side Band (see SSB)

 

VHF
Very High Frequency. Used to describe radio signals in the 30MHz to 300MHz frequency band

 

VoIP
Voice over Internet Protocol

 

WAN
Wide Area Network. To be distinguished from the LAN, a WAN interconnects geographically remote sites

 

WAP
Wireless Access Protocol

 

WARC
World Administrative Radio Conference (of the ITU)

 

WEEE
Waste Electrical and Electronic Equipment

 

WIRELESS
A generalised term used to describe a non-wired communication link

 

WLAN
Wireless Local Area Network

 

WLR
Wholesale Line Rental

 

ZVEI
Zentralverband Elektrotechnik-(Electronic Manufacturing Industry Association of Germany) Standards body which has specified one of the coding schemes used in Selcall

 

 

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