Some Terms and Informative knowledge about GSM.


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

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

The enhancement of GSM which includes technologies such as GPRS

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

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

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

Octantal Phase Shift Keying

AAL - ATM Adaptation Layer

A-bis = Interface between the BSC and BTS in a GSM network
AB - Access Burst
used for random access and characterized 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

ABR - Available Bit Rate

AC - Alternating Current ( the standard electricity type )
ACCH - Analog Control Channel
ACTS - Advanced Communications Technologies and Services.
a European technology initiative
ACU - Antenna Combining Unit

AC Charger :an accessory device that allows you to power and/or charge your phone from a wall outlet

ADC - Analog to Digital Converter

Advice of charge:A service which provides the user with information on the cost of calls from a mobile phone

AFC - Automatic Frequency Control

AGC - Automatic Gain Control

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

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

AM - Amplitude Modulation

AMPS - Advanced Mobile Phone Service
Advanced Mobile Phone System (AMPS) is the analog mobile phone system standard developed by Bell Labs, and officially introduced in the Americas in 1983. It was the primary analog mobile phone system in North America (and other locales) through the 1980s and into the 2000s, and is still widely available today, although use has dropped considerably with the introduction of various digital standards.

Total Access Communication System (TACS) and ETACS are mostly-obsolete variants of AMPS which were used in some European countries (including the UK). TACS was also used in Japan under the name Japanese Total Access Communication (JTAC).

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

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

a part of a cell phone that receives and transmits cellular radio-frequency transmissions.

ASCII-American Standard Code for Information Interchange

ASIC - Application Specific Integrated Circuit
Electronic chips designed for some concrete purposes (for example, in phone it controls communication between MCU and DSP) They're designed and produced by the companies which use them.

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

AVCH - Analog Voice Channel

BB5 - base band 5

BCC - Base-station Color Code

B-CDMA - Broadband Code Division Multiple Access

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

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

BGA - ball grid array

B-ISDN - Broadband ISDN

BPS - Bits Per Second
( a measure of how fast binary digits can be sent through a channel. The number of 0s and 1s that travel down the channel per second.)

Base transceiver Station Identity Code

BTS - Base Transceiver Station
(This device allows communication between phones and cellular network or it is the network entity which communicates with the mobile station)

Back -light Illumination
illuminates a wireless device’s display and keypad for better low light viewing
Band :
a specific range of frequencies in the radio frequency (RF) spectrum.

A chargeable device which provides the mobile phone with power. A variety of battery technologies have been used for mobile phones including nickel cadmiu(NiCad),nickel metal hydride (NiMH) and lithium ion (Li-ion)
Battery status/Battery charge display
An indication of the amount of battery life remaining
Battery Capacity the capacity of wireless devices’ battery. Measured in milliampere hours (mAh).

Call barring
A service which enables users to bar certain incoming or outgoing calls on their mobile phones

Call timer:
A service which keeps track of the amount of airtime being used by the subscriber on a cumulative basis

Call divert:
The capability to divert incoming calls to another phone (fixed or mobile) or to an answering service

Call hold:
The ability to put an ongoing call on hold whilst answering or making a second call

Caller ID:
Caller Identification (displays the name/number of the person calling a mobile phone. Also known as CLI)

CB - Cell Broadcast

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

CCONT- Current Controller (in nokia fones)

CDMA - Code Division Multiple Access
(Code Division Multiple Access; also known as spread spectrum (or IS-95), 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)

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 Site:
a fixed cellular tower and radio antenna that handles communication with subscribers in a particular area or cell. A cellular network is made up of many cell sites, all connected back to the wired phone system.

CF - Call Forwarding

CI - Carrier to Interference ratio

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

CNT- Content

COBBA- Common Baseband Analog

CPU - Central Processing Unit

CMOS - Complementary Metal Oxide Substrate

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

CRC - Cyclic Redundancy Check

CT - Cordless Telephony

CTA - Cordless Terminal Adaptor (a DECT term)

CTM - Cordless Terminal Mobility

CTR - Common Technical Regulation

CUG - Closed User Group

D/A - Digital to Analogue conversion

DAC - Digital to Analogue Converter

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

Data capable:
Mobile phones which have the capability to enable transmission of data from a laptop computer or PDA via the phone

Data cable : interface for connecting a mobile fone to pc

db - decibel (unit if sound)

DCT /3,4 - digital core technology

DCT/L - digital core technology linda

DCCH - Digital Control Channel
DTCH - Digital Traffic Channel
DTX - Discontinuous Transmission Exchange

DCA - Dynamic Channel Assignment

DCCH - Dedicated Control Channels
( responsible for roaming, handovers, encryption etc)

DCE - Data Communications Equipment

DCH - Data Clearing House

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

a method of representing information as numbers with discrete values; usually expressed as a sequence of bits
Digital a method of encoding a transmission that involves translating information (in the case of digital phones the information would be a voice conversation) into a series of 0’s and 1’s. Digital communications technology offers cleaner calls without the static and distortion that is common with analog phones. The majority of new handsets sold today are digital rather than analog technology.

DSP - Digital Signal Processor
Digital Signal Processing refers to manipulating analog information, such as sound or photographs that has been converted into a digital form to improve accuracy and reliability of digital communications.

DSC- Digital Signal Controller

DTE - Data Terminal Equipment

DTMF - Dual Tone Multi Frequency;
(better know as Touch Tone. The tones generated by touching the keys on the phone are used for a variety of purposes )

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

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)

EEPROM - Electrically Erasable Programmable Read Only Memory

EFR- Enhanced Full Rate
(Enhanced Full Rate (codec): an improved version of the standard voice codec used in GSM phones; offers improved speech quality without impacting on network capacity)

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

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, customization user interfaces, connectivity options and a range of development tools

EPROM - Erasable Programmable Read Only Memory

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

FB - Frequency Correction Burst; used for frequency synchronization of the mobile

FDD - Frequency Division Duplex

FOMA - Freedom Of Mobile multimedia Access

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

GMSC - Gateway Mobile Services Switching Center; the gateway between two networks

GCF - Global Certification Forum

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.

A unit of frequency equal to one billion Hertz per second

GMPCS - Global Mobile Personal Communications by Satellite

GMSK - Gaussian filtered Minimum Shift Keying

General Packet Radio Service (GPRS) is a mobile data service available to users of GSM and IS-136 mobile phones. GPRS data transfer is typically charged per megabyte of transferred data, while data communication via traditional circuit switching is billed per minute of connection time, independently of if the user actually has transferred data or been in an idle state. GPRS can be utilized for services such as WAP access, SMS and MMS, but also for Internet communication services such as email and web access. In the future, it is expected that low cost voice over IP will be made available in cell phones.

The Global Positioning System (GPS), is currently the only fully-functional satellite navigation system. More than two dozen GPS satellites are in medium Earth orbit, transmitting signals allowing GPS receivers to determine the receiver's location, speed and direction.

GRX - GPRS Roaming Exchange


The Global System for Mobile Communications, GSM (original acronym: Groupe Spécial Mobile) is the most popular standard for mobile phones in the world. GSM service is used by over 2 billion people across more than 212 countries and territories.[1][2] The ubiquity of the GSM standard makes international roaming very common between mobile phone operators, enabling subscribers to use their phones in many parts of the world. GSM differs significantly from its predecessors in that both signaling and speech channels are Digital call quality, which means that it is considered a second generation (2G) mobile phone system. This fact has also meant that data communication was built into the system from the 3rd Generation Partnership Project (3GPP).

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

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

HR - Half Rate Traffic

IC - Integrated Circuit

ICSP - In Circuit Serial Programming

IF- Intermediate Frequency

Infrared data port:
A facility on a mobile phone to allow information to be exchanged with other devices e.g. a PC using infra red technology

The Internet is the worldwide, publicly accessible network of interconnected computer networks that transmit data by packet switching using the standard Internet Protocol (IP). It is a "network of networks" that consists of millions of smaller domestic, academic, business, and government networks, which together carry various information and services, such as electronic mail, online chat, file transfer, and the interlinked Web pages and other documents of the World Wide Web.

IMEI - International Mobile Equipment Identity
The International Mobile Equipment Identity (IMEI) is a number unique to every GSM and UMTS mobile phone. It is usually found printed on the phone underneath the battery and can also be found by dialing the sequence *#06# into the phone.

The IMEI number is used by the GSM network to identify valid devices and therefore can be used to stop a stolen phone from accessing the network. For example, if a mobile phone is stolen, the owner can call his or her network provider and instruct them to "ban" the phone using its IMEI number. This renders the phone useless, regardless of whether the phone's SIM is changed.

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

IMSI - International Mobile Subscriber Identity
(an internal subscriber identity used only by the network)

IP - Internet Protocol

IrDA - Infra red Data Association

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

ISDN - Integrated Services Digital Network

International Standards Organisation

ISP - Internet Service Provider

software developed by Motorola and built into some wireless phones and PDAs that makes typing words on a keypad easier. The competitor to iTAP is T9

JAF - Just Another Flasher

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

JPEG- Joint Photographic Experts Group

JTAG - Joint Test Action Group

Kbps : Kilobits Per Second, a measure of bandwidth

Local Area Network

Local Area Network Services

LED - Light Emitting Diode
(a semiconductor device that illuminates when electricity passes through it. Often used as an indicator light, or to spell out words and numbers. LEDs come in many colors, and some LEDs contain multiple elements and are therefore capable of multiple colors. Provides good visibility in direct sunlight and in darkness)

LPT - Line Print Terminal

Land Mobile Satellite Service

A function on a cellular phone which, when activated, prevents use of the phone until the user enters a security code

LCD - Liquid crystal display

Lithium Ion battery:
a type of rechargeable battery for cell phones which is generally lighter weight than earlier battery types, has a relatively longer cycle life, and generally does not suffer from “memory” effect.

MAC - Media Access Control; the lower sub-layer of the OSI system

MAD - Memory Analog Digital

MAP - Mobile Application Part

Mb- Megabite
( a unit of data transmission speed equal to one million bits per second)

MCC - Mobile Country Code

MCU - Micro Control Unit

MCPA - Multi Carrier Power Amplifier

MHz - Megahertz (a unit of frequency equal to one million Hertz)

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)

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

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

MSIN - Mobile Station Identification Number

MSISDN - Mobile Station International ISDN Number

MSK - Minimum Shift Keying (Another term for FFSK)

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)

Master Reset:
restores the setting to factory

MIDI - Musical Instrument Digital Interface
(a standard that allows digital musical instruments to communicate with one another. In cell phone terms, MIDI is what gives you polyphonic sounds; which means your ring tones can sound like real music instead of beeps. )

MMS - Multimedia Messaging Service
(a further extension of SMS and EMS.MMS is designed to make use of newer and quicker mobile transmission methods such as GPRS, HSCSD, EDGE and UMTS, involving the attachment of multimedia extensions to messages, such as video and sound. An e-mail function is also planned. )

MO-SMS - Mobile-Originated Short Message Service
(the ability to send short text messages from a phone. Both the phone and the carrier’s network must support this feature for it to work. Messages can be sent to other phones by phone number. Many phones also allow sending messages directly to e-mail addresses. )

NCC (National Color Code or Network Color Code

Norme European de Telecommunications

NMSI - National Mobile Subscriber Identity

No Service:
An indication on the display of a cellular phone that indicates that the user is in an area where cellular service is unavailable

OMAP - Open Multimedia Applications Platform

OTP - One Time Programmable

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

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

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

Personal Digital Assistant

Personal Identifier Number

Power Supply Unit

Personal Communications Networks; an outdated term for GSM services in the 1800MHz band

Personal Digital Assistant; a sophisticated handheld device with advanced display

facilities and a range of business-oriented software programs

Phone book
A list of personal names and numbers stored in a mobile phone’s internal memory or in

the SIM card. These numbers can be called by accessing the appropriate memory and

making a single key stroke

Personal Identity Number; a number, usually four digits, that must be keyed into a

mobile phone to make it work. A security measure to prevent unauthorized usage

P-Java (Personal Java) a Java API and specification for running Java applications on

small devices.

Packet a piece of data transmitted over a packet-switching network such as the Internet

or wireless Internet; a packet includes not just data but also its destination.

Packet Switching a type of communication that splits information into “packets” of data

for transmission. This is efficient, as it only uses radio spectrum when it’s actually

sending something, rather than keeping an open channel at all times (as is done in

circuit switching). Packet switching is a core component to 3G technology.

Passive Matrix Display an LCD technology that uses a grid to supply the charge to each

particular pixel on the display. An STN screen has a slower refresh rate than a TFT

screen, but it’s cheaper. Also called a Super Twist Nematic of STN display.

PC Card (PCMCIA) a removable, credit-card sized devices that may be plugged into slots

in PCS and wireless communication devices to provide fax or modem functions or network


PCMCIA (Personal Computer Memory Card International Association) a group of hardware

manufacturers and vendors responsible for developing standards for PC Cards (also

called PCMCIA cards.)


also known as DCS 1800 or GSM 1800, PCN is a term used to describe a wireless

communication technology in Europe and Asia.

PDA (personal digital assistant) a portable, handheld computing device that acts as an

electronic organizer. PDAs are typically used for managing addresses, appointments,

to-do lists and notes, but some newer models support wireless Internet access, e-mail,

and other interactive applications. Also referred to as Handheld Computers. PDAs come

in two major flavors - Palm and Pocket PC.

PIN (Personal Identification Number) a numeric code or password that may be required by

a service provider in order to make outgoing calls or obtain access to certain

applications and data. This code is always associated to a SIM card, not a phone and is

designed to help guard against cellular fraud.

PTT (Push-To-Talk) a two-way communication service that works like a “walkie talkie”.

This feature, found on Motorola iDEN phones from Nextel and Telus Mobility’s Mike,

allow communication in only direction at a time unlike a cell phone that allows for

simultaneous conversations. New PTT systems are now being introduced that use VoIP

technology to provide PTT service digitally over 3G data networks

PUK (Personal Unblocking Code) used to unblock a blocked SIM card, this code is given

during the suBion of a phone

represents the on/off (power) key on some wireless devices.

RAM - Random Access Memory

RAP3G- Radio Application Processor 3rd Generations

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

RF AMP = Radio Frequency Amplifier

RFP - Radio Fixed Part
(equivalent to a base station in a DECT system)

RP - Radio Part

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

A device which forwards information in a network on a connection less basis

RT - Remote Terminal

RX :- signal received

SAR - Specific Absorption Rate

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

Security Code:
a numeric code (password) used to prevent unauthorized or accidental alteration of data programmed into wireless phones. The security code can be used by the owner of a phone to change the lock code.

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

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

a combination of mobile phone and personal digital assistant

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)

SP - Service Provider

SRAM - Syncronous Random Access Memory

Standby time:
The length of time a battery can power a mobile phone when it is switched on but not making or receiving calls

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. Matsua has subsequently joined Symbian


TACS - Total Access Communications System

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)

TFD : Thin Film Diode
(a type of LCD (Liquid Crystal Display) flat-panel display technology. TFD technology combines the excellent image quality and fast response times of TFT, with the low power consumption and low cost of STN.)

TFT - Thin Film Transistor
(an LCD technology that uses transistors to precisely control the voltage to each liquid crystal cell. This is also referred to as an “active matrix” display. TFT screens offer the best image quality and refresh rates, but at a higher cost.)

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

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

The length of time a battery can power a mobile phone when making or receiving calls

T9 :
software built into some wireless phones and PDAs that makes typing words on a keypad easier. The competitor to T9 is iTAP

Tri-Band fone:
a phone capable of operating on three different digital frequencies (example: 900MHz, 1800MHz and 1900MHz).


Upp - Universal power processor

UI - User Interface

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

URL - Uniform Resource Locator( the addressing system of the Internet)

UTRA - Universal Terrestrial Radio Access

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

UWB - Ultra Wide Band

USB - Universal Serial Bus


VBR - Variable Bit Rate

VCO - Voltage Control Oscillator

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

VSLI- Very Large Scale Integration

A service offered by network operators whereby calls received when the mobile is in use, switched off or out of coverage can be diverted to an answering service which can be personalised by the user

WAP - Wireless Application Protocol
(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)

WASP - Wireless Application Service Provider

Web clipping:
this is an application that allows a user to extract relevant information from a web page for display on a smart phone or a PDA.

Wi-Fi Wireless Fidelity, the popular term for the 802.11b wireless Ethernet standard.

Windows CE:
a streamlined version of Windows from Microsoft for handheld computers which has since been upgraded and renamed Pocket PC. Windows CE run Pocket versions of Microsoft office applications such as Word and Excel as well as many applications that were geared specifically for the smaller platform.

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 wireless