GSM

GSM (850/900/1800/1900) GSM/GPRS/EDGEGSM technologyGlobal System for Mobile CommunicationsGlobal System for Mobile Communications (GSM)GSM-1800GSM900mobile phone base station GSM/3G Mobile Service.gsm
GSM (Global System for Mobile communications) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation (2G) digital cellular networks used by mobile devices such as tablets.wikipedia
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2G

2.5G2.75G2.5
GSM (Global System for Mobile communications) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation (2G) digital cellular networks used by mobile devices such as tablets. GSM networks operate in a number of different carrier frequency ranges (separated into GSM frequency ranges for 2G and UMTS frequency bands for 3G), with most 2G GSM networks operating in the 900 MHz or 1800 MHz bands.
Second-generation 2G cellular networks were commercially launched on the GSM standard in Finland by Radiolinja (now part of Elisa Oyj) in 1991.

3GPP

3rd Generation Partnership Project3rd Generation Partnership Project (3GPP)Third Generation Partnership Project (3GPP)
Subsequently, the 3GPP developed third-generation (3G) UMTS standards, followed by fourth-generation (4G) LTE Advanced standards, which do not form part of the ETSI GSM standard.
The initial scope of 3GPP was to make a globally applicable third-generation (3G) mobile phone system specification based on evolved Global System for Mobile Communications (GSM) specifications within the scope of the International Mobile Telecommunications-2000 project of the International Telecommunication Union (ITU).

Circuit Switched Data

CSDHSCSDcircuit-switched data
This expanded over time to include data communications, first by circuit-switched transport, then by packet data transport via GPRS (General Packet Radio Services) and EDGE (Enhanced Data rates for GSM Evolution, or EGPRS).
In communications, Circuit Switched Data (CSD) is the original form of data transmission developed for the time-division multiple access (TDMA)-based mobile phone systems like Global System for Mobile Communications (GSM).

Full Rate

GSMGSM 06.10GSM Full Rate
It may also refer to the (initially) most common voice codec used, Full Rate.
Full Rate (FR or GSM-FR or GSM 06.10 or sometimes simply GSM) was the first digital speech coding standard used in the GSM digital mobile phone system.

LTE Advanced

LTE-A4G+LTE
Subsequently, the 3GPP developed third-generation (3G) UMTS standards, followed by fourth-generation (4G) LTE Advanced standards, which do not form part of the ETSI GSM standard.
More LTE networks were deployed globally during 2010 as a natural evolution of several 2G and 3G systems, including Global system for mobile communications (GSM) and Universal Mobile Telecommunications System (UMTS) in the 3GPP family as well as CDMA2000 in the 3GPP2 family.

3G

3G networkIMTthird generation
Subsequently, the 3GPP developed third-generation (3G) UMTS standards, followed by fourth-generation (4G) LTE Advanced standards, which do not form part of the ETSI GSM standard.
the UMTS (Universal Mobile Telecommunications Service) system, first offered in 2001, standardized by 3GPP, used primarily in Europe, Japan, China (however with a different radio interface) and other regions predominated by GSM (Global Systems for Mobile) 2G system infrastructure. The cell phones are typically UMTS and GSM hybrids. Several radio interfaces are offered, sharing the same infrastructure:

Cellular network

cellularmobile networkcellular networks
GSM (Global System for Mobile communications) is a standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation (2G) digital cellular networks used by mobile devices such as tablets.
The details of the process of paging vary somewhat from network to network, but normally we know a limited number of cells where the phone is located (this group of cells is called a Location Area in the GSM or UMTS system, or Routing Area if a data packet session is involved; in LTE, cells are grouped into Tracking Areas).

SMS

short message servicetext messagetext messages
The following year saw the sending of the first short messaging service (SMS or "text message") message, and Vodafone UK and Telecom Finland signed the first international roaming agreement.
The first action plan of the CEPT Group GSM was approved in December 1982, requesting that "The services and facilities offered in the public switched telephone networks and public data networks ... should be available in the mobile system."

UMTS

WCDMA3GUniversal Mobile Telecommunications System
Subsequently, the 3GPP developed third-generation (3G) UMTS standards, followed by fourth-generation (4G) LTE Advanced standards, which do not form part of the ETSI GSM standard. The GSM standard does not include the 3G Universal Mobile Telecommunications System (UMTS) code division multiple access (CDMA) technology nor the 4G LTE orthogonal frequency-division multiple access (OFDMA) technology standards issued by the 3GPP. Finally, with the development of UMTS, EFR was refactored into a variable-rate codec called AMR-Narrowband, which is high quality and robust against interference when used on full-rate channels, or less robust but still relatively high quality when used in good radio conditions on half-rate channel.
The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard.

Vodafone UK

VodafoneUK
The following year saw the sending of the first short messaging service (SMS or "text message") message, and Vodafone UK and Telecom Finland signed the first international roaming agreement.
Racal Telecom was demerged from Racal Electronics in 1991, becoming Vodafone Group, and introduced the country's first GSM mobile phone network the same year.

Harri Holkeri

HolkeriHarri Hermani Holkeri
The former Finnish prime minister Harri Holkeri made the world's first GSM call on July 1, 1991, calling Kaarina Suonio (deputy mayor of the city of Tampere) using a network built by Telenokia and Siemens and operated by Radiolinja.
On 1 July 1991 he made the world's first GSM call.

Femtocell

femtofemtocellsaccess point base station
There are five different cell sizes in a GSM network—macro, micro, pico, femto, and umbrella cells.
Although much attention is focused on WCDMA, the concept is applicable to all standards, including GSM, CDMA2000, TD-SCDMA, WiMAX and LTE solutions.

Code-division multiple access

CDMAcode division multiple accessCDMA-450
The GSM standard does not include the 3G Universal Mobile Telecommunications System (UMTS) code division multiple access (CDMA) technology nor the 4G LTE orthogonal frequency-division multiple access (OFDMA) technology standards issued by the 3GPP.
IS-95, also called "cdmaOne", and its 3G evolution CDMA2000, are often simply referred to as "CDMA", but UMTS, the 3G standard used by GSM carriers, also uses "wideband CDMA", or W-CDMA, as well as TD-CDMA and TD-SCDMA, as its radio technologies.

Radiolinja

The former Finnish prime minister Harri Holkeri made the world's first GSM call on July 1, 1991, calling Kaarina Suonio (deputy mayor of the city of Tampere) using a network built by Telenokia and Siemens and operated by Radiolinja.
Radiolinja was a Finnish GSM operator founded on September 19, 1988.

Optus

Cable & Wireless OptusCable and Wireless OptusOptus B3
Optus in Australia completed the shut down its 2G GSM network on August 1, 2017, part of the Optus GSM network covering Western Australia and the Northern Territory had earlier in the year been shut down in April 2017.
GSM/GPRS utilising 900 MHz/1800 MHz covering 98.5% of the population

GPRS core network

serving GPRS support node3GPP GPRS Core Networkcore-network
GPRS Core Network – the optional part which allows packet-based Internet connections
The GPRS system is an integrated part of the GSM network switching subsystem.

Timing advance

technical limitations
The longest distance the GSM specification supports in practical use is 35 km. There are also several implementations of the concept of an extended cell, where the cell radius could be double or even more, depending on the antenna system, the type of terrain, and the timing advance.
In the GSM cellular mobile phone standard, timing advance value corresponds to the length of time a signal takes to reach the base station from a mobile phone.

GSM frequency bands

GSM 850GSM 900850 / 900 / 1800 / 1900
GSM networks operate in a number of different carrier frequency ranges (separated into GSM frequency ranges for 2G and UMTS frequency bands for 3G), with most 2G GSM networks operating in the 900 MHz or 1800 MHz bands.
GSM frequency bands or frequency ranges are the cellular frequencies designated by the ITU for the operation of GSM mobile phones and other mobile devices.

Mobile phone

cell phonemobilemobile phones
Also that year, Telecom Australia became the first network operator to deploy a GSM network outside Europe and the first practical hand-held GSM mobile phone became available.
In 1991, the second-generation (2G) digital cellular technology was launched in Finland by Radiolinja on the GSM standard.

SIM lock

unlockedlockedSIM unlocked
Some operators will block this by allowing the phone to use only a single SIM, or only a SIM issued by them; this practice is known as SIM locking.
A SIM lock, simlock, network lock, carrier lock or (master) subsidy lock is a technical restriction built into GSM and CDMA mobile phones by mobile phone manufacturers for use by service providers to restrict the use of these phones to specific countries and/or networks.

Picocell

picopico cellpico cells
There are five different cell sizes in a GSM network—macro, micro, pico, femto, and umbrella cells.
In cellular wireless networks, such as GSM, the picocell base station is typically a low-cost, small (typically the size of a ream of A4 paper), reasonably simple unit that connects to a base station controller (BSC).

Time-division multiple access

TDMAtime division multiple accessdynamic TDMA
These eight radio timeslots (or burst periods) are grouped into a TDMA frame.
TDMA is used in the digital 2G cellular systems such as Global System for Mobile Communications (GSM), IS-136, Personal Digital Cellular (PDC) and iDEN, and in the Digital Enhanced Cordless Telecommunications (DECT) standard for portable phones.

Adaptive Multi-Rate audio codec

AMRAMR-NBAdaptive Multi-Rate
Finally, with the development of UMTS, EFR was refactored into a variable-rate codec called AMR-Narrowband, which is high quality and robust against interference when used on full-rate channels, or less robust but still relatively high quality when used in good radio conditions on half-rate channel.
AMR was adopted as the standard speech codec by 3GPP in October 1999 and is now widely used in GSM and UMTS.

Enhanced full rate

EFREnhanced Full-Rate (EFR)ETSI GSM enhanced full rate
GSM was further enhanced in 1997 with the enhanced full rate (EFR) codec, a 12.2 kbit/s codec that uses a full-rate channel.
Enhanced Full Rate or EFR or GSM-EFR or GSM 06.60 is a speech coding standard that was developed in order to improve the quite poor quality of GSM-Full Rate (FR) codec.

Microcell

micro-cellularmicro
There are five different cell sizes in a GSM network—macro, micro, pico, femto, and umbrella cells.
Typically the range of a microcell is less than two kilometers wide, whereas standard base stations may have ranges of up to 35 kilometres (22 mi).