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GSM & Cell Phone Terminology
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Consumer Quick Glossary
Advice of charge
A service which provides the user with information on the cost of
calls from a mobile phone
Airtime
The amount of time a subscriber spends using his/her mobile phone
Battery status/Battery charge display
An indication of the amount of battery life remaining
Battery
A chargeable device which provides the mobile phone with power. A
variety of battery technologies have been used for mobile phones
including nickel cadmium (NiCad), nickel metal hydride (NiMH) and
lithium ion (Li-ion)
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
CLI
See Caller ID
CLR
Clear; the key on a cellular phone which is pressed to remove
information from the display
Data capable
Mobile phones which have the capability to enable transmission of
data from a laptop computer or PDA via the phone
Dual band
Mobile phones which support transmission and reception of calls on
the 900MHz and 1800MHz bands with seamless handover between the two
frequency bands
EFR
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
END
The key on a cellular phone which is pressed to terminate a call
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
Lock
A function on a cellular phone which, when activated, prevents use
of the phone until the user enters a security code
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
One-touch dialling
The ability to dial frequently called numbers using a single key
stroke; see Speed Dialling
PCN
Personal Communications Networks; an outdated term for GSM services
in the 1800MHz band
PDA
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
PIN
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 unauthorised usage
RCL
The function on a cellular phone which recalls a phone number from
memory
Roaming
The ability to make and receive calls on the same mobile phone when
travelling outside the area of the home network operator
Smartphone
a combination of mobile phone and personal digital assistant
SND
Send; The key on a cellular phone which initiates a call or answers
an incoming call
Speed dialling
See One-touch dialling
Standby time
The length of time a battery can power a mobile phone when it is
switched on but not making or receiving calls
Talk-time
The length of time a battery can power a mobile phone when making or
receiving calls
Voicemail
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; a standard whereby mobile phones can
gain access to specially tailored Internet websites
WML
Wireless Markup Language; a specially designed markup language used
for tailoring WAP content. WML enables optimum usage of the limited
display capabilities of the mobile phone
Detailed GSM Glossary
#
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
A
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
B
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
C
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
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)
E
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
F
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
G
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
H
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
I
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
J
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
K
L
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
M
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
N
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
O
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
P
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
Q
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
R
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
S
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 standardizing 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
T
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 standardization
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)
U
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
V
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
W
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
X
XML
eXtended Markup Language
Y
Z |