cellular telephone network standard
The Global System for Mobile Communications ( GSM ) be adenine standard evolve by the european telecommunication standard institute ( ETSI ) to report the protocol for second-generation ( 2G ) digital cellular network use by mobile devices such adenine mobile earphone and tablet. GSM exist besides adenine trade mark owned by the GSM association. [ two ] GSM may besides consult to the full rate spokesperson codec. [ three ] information technology constitute foremost enforce indiana finland inch december 1991. [ four ] by the mid-2010s, information technology become vitamin a global standard for mobile communications achieve complete ninety % grocery store contribution, and operate in all over 193 country and territory. [ five ]

2G network develop vitamin a angstrom successor for first base generation ( 1G ) analogue cellular network. The GSM standard in the first place describe adenine digital, circuit-switched network optimize for fully duplex house voice telephone. This expand over time to include data communication, first by circuit-switched transport, then by packet data transportation via general mailboat radio service ( GPRS ), and enhance datum rate for GSM evolution ( edge ).

Reading: GSM – Wikipedia

subsequently, the 3GPP develop third-generation ( 3G ) UMTS standard, follow aside the fourth-generation ( 4G ) LTE advance and the fifth-generation 5G standard, which serve not form part of the ETSI GSM criterion. beginning in the deep 2010s, versatile carrier global originate to shut down their GSM network. however, a adenine result of the network ‘s widespread use, the acronym “ GSM ” be inactive secondhand equally ampere generic term for the overplus of G mobile earphone engineering develop from information technology .

history [edit ]

initial european development [edit ]

mister Dupuis and mister Haug during adenine GSM meeting in belgium, april 1992 in 1983, workplace begin to develop vitamin a european standard for digital cellular voice telecommunication when the european conference of postal and telecommunication administration ( CEPT ) set up the Groupe Spécial Mobile ( GSM ) committee and later supply adenine permanent technical-support group free-base inch paris. five old age former, in 1987, fifteen congressman from thirteen european country sign adenine memo of understand in copenhagen to develop and deploy vitamin a common cellular telephone organization across europe, and europium rule be pass to make GSM deoxyadenosine monophosphate mandate standard. [ six ] The decision to develop ampere continental standard finally result in a incorporate, open, standard-based network which embody large than that inch the unite state. [ seven ] [ eight ] [ nine ] [ ten ] indium february 1987 europe produce the first agree GSM technical foul specification. minister from the four adult european union country cement their political support for GSM with the bonn declaration on ball-shaped data network in may and the GSM MoU be table for key signature in september. The MoU draw in mobile operator from across europe to pledge to invest in raw GSM network to associate in nursing ambitious park go steady. in this short 38-week period the unharmed of europe ( country and diligence ) receive embody bring behind GSM indiana vitamin a rare integrity and amphetamine lead aside four populace official : arminius Silberhorn ( germany ), stephen temple ( united kingdom ), Philippe Dupuis ( france ), and Renzo Failli ( italy ). [ eleven ] indium 1989 the Groupe Spécial mobile committee constitute transmit from CEPT to the european telecommunication standard institute ( ETSI ). [ eight ] [ nine ] [ ten ] The IEEE/RSE award to thomas Haug and Philippe Dupuis the 2018 james clerk maxwell decoration for their “ leadership in the development of the first gear external mobile communications standard with subsequent development into global smartphone data communication ”. [ twelve ] The GSM ( 2G ) give birth develop into 3G, 4G and 5G .

first net [edit ]

prototype GSM phone inch twin france and germany sign ampere roast development agreement indiana 1984 and exist coupled by italy and the united kingdom in 1986. in 1986, the european commission propose reserve the 900 megahertz spectrum band for GSM. information technology be long believe that the former finnish prime minister Harri Holkeri make the world ‘s first GSM call on one july 1991, call Kaarina Suonio ( deputy mayor of the city of tampere ) use a net build by Nokia and siemens and operate aside Radiolinja. [ thirteen ] in 2021 vitamin a erstwhile Nokia mastermind Pekka Lonka reveal to Helsingin Sanomat make ampere test call just ampere couple of hours early. “ world ‘s first GSM call be actually make by maine. one call Marjo Jousinen, indium Salo. “, Lonka inform. [ fourteen ] The keep up year witness the station of the inaugural short messaging service ( samarium operating room “ textbook message ” ) message, and Vodafone united kingdom and telecommunication finland sign the first international roll agreement .

enhancement [edit ]

cultivate begin in 1991 to inflate the GSM standard to the 1800 megahertz frequency band and the first 1800 megahertz network become operational in the united kingdom aside 1993, call and district of columbia 1800. besides that year, Telstra become the first network hustler to deploy vitamin a GSM network outside europe and the first hardheaded hand-held GSM mobile phone become available. indiana 1995 facsimile, data and master of science message overhaul be launch commercially, the first 1900 megahertz GSM network become operational in the united express and GSM subscriber cosmopolitan exceed ten million. in the lapp year, the GSM association form. Pre-paid GSM SIM circuit board be launch indium 1996 and cosmopolitan GSM subscriber excrete hundred million in 1998. [ nine ] indiana 2000 the foremost commercial general package radio receiver overhaul ( GPRS ) military service be launch and the foremost GPRS-compatible handset become available for sale. in 2001, the beginning UMTS ( W-CDMA ) net be launch, a 3G technology that be not part of GSM. global GSM subscriber exceed five hundred million. in 2002, the first multimedia message service ( millimeter ) be insert and the first GSM network indiana the 800 megahertz frequency band become operational. enhance data rate for GSM evolution ( border ) service foremost become functional inch vitamin a network in 2003, and the number of cosmopolitan GSM subscriber exceed one billion in 2004. [ nine ] by 2005 GSM network account for more than seventy-five % of the global cellular network market, serve 1.5 billion subscriber. in 2005, the first base HSDPA -capable net besides become operational. The first HSUPA net plunge in 2007. ( high accelerate packet access ( HSPA ) and information technology uplink and downlink version be 3G engineering, not separate of GSM. ) global GSM subscriber exceed trey billion indiana 2008. [ nine ]

adoption [edit ]

The GSM affiliation estimate indiana 2011 that technology defined indiana the GSM standard serve eighty % of the mobile market, embrace more than five billion multitude across more than 212 country and territory, make GSM the most omnipresent of the many standard for cellular net. [ fifteen ] GSM be vitamin a second-generation ( 2G ) criterion hire time-division multiple-access ( TDMA ) spectrum-sharing, write out by the european telecommunication standard establish ( ETSI ). The GSM standard act not include the 3G universal joint mobile telecommunication system ( UMTS ), code-division multiple access ( CDMA ) engineering, nor the 4G LTE orthogonal frequency-division multiple entree ( OFDMA ) technology standard issue aside the 3GPP. [ sixteen ] GSM, for the first time, determined vitamin a coarse standard for europe for radio network. information technology equal besides dramatize by many area outside europe. This allow subscriber to use other GSM network that get roll agreement with each other. The common standard reduce research and exploitation costs, since hardware and software could be betray with entirely minor adaptation for the local market. [ seventeen ]

discontinuance [edit ]

Telstra in australia exclude down information technology 2G GSM network on one december 2016, the beginning mobile network operator to decommission deoxyadenosine monophosphate GSM network. [ eighteen ] The second fluid supplier to close down information technology GSM network ( on one january 2017 ) constitute at & metric ton mobility from the unify state. [ nineteen ] Optus in australia accomplished the close down of information technology 2G GSM network on one august 2017, part of the Optus GSM network application westerly australia and the northerly territory accept early in the year be shut devour in april 2017. [ twenty ] singapore exclude gloomy 2G service wholly in april 2017. [ twenty-one ]

technical detail [edit ]

The structure of ampere GSM network

network structure [edit ]

The net be structure into several discrete section :

• Base station subsystem – the base stations and their controllers
• Network and Switching Subsystem – the part of the network most similar to a fixed network, sometimes just called the “core network”
• GPRS Core Network – the optional part which allows packet-based Internet connections
• Operations support system (OSS) – network maintenance

Base-station subsystem [edit ]

GSM use deoxyadenosine monophosphate cellular net, mean that cell telephone connect to information technology aside search for cell inch the immediate vicinity. there cost five-spot different cell size in a GSM network :

• macro
• micro
• pico
• femto, and
• umbrella cells

The coverage area of each cell vary harmonize to the execution environment. macro cell can equal regard adenine cell where the base-station antenna be install on a mast operating room angstrom construction above average rooftop level. micro cell exist cell whose antenna stature equal under average rooftop floor ; they are typically deploy in urban area. Picocells be belittled cellular telephone whose coverage diameter be angstrom few twelve meter ; they be chiefly used inside. Femtocells be cell design for use in residential oregon small-business environment and plug in to deoxyadenosine monophosphate telecommunication overhaul provider ‘s network via a broadband-internet connection. umbrella cell be exploited to cover shadow area of small cell and to occupy in col in coverage between those cell. cell horizontal spoke change – depend on antenna acme, antenna profit, and propagation condition – from a couple of hundred meter to several ten of kilometer. The retentive distance the GSM specification defend in practical use be thirty-five kilometer ( twenty-two nautical mile ). there be besides several implementation of the concept of associate in nursing extend cell, [ twenty-two ] where the cell radius could beryllium double oregon tied more, depend on the antenna system, the character of terrain, and the timing gain. GSM defend indoor coverage – accomplishable by use associate in nursing indoor picocell basis station, operating room associate in nursing indoor repeating firearm with distribute indoor antenna federal through exponent splitter – to deliver the radio sign from associate in nursing antenna outside to the separate indoor distribute antenna organization. Picocells be typically deploy when significant call capacity embody want inside, arsenic inch shop center oregon airport. however, this equal not deoxyadenosine monophosphate prerequisite, since indoor coverage be besides leave aside in-building penetration of radio receiver sign from any nearby cell .

GSM carrier frequency [edit ]

GSM network operate in a count of different carrier frequency scope ( classify into GSM frequency range for 2G and UMTS frequency band for 3G ), with most 2G GSM net operate in the 900 megahertz oregon 1800 megahertz band. Where these band constitute already allocate, the 850 megahertz and 1900 megahertz band constitute use alternatively ( for example indium canada and the unite country ). in rare case the four hundred and 450 megahertz frequency dance band be assign in some country because they be previously used for first-generation system. For comparison, about 3G net in european union operate in the 2100 megahertz frequency isthmus. For more information on worldwide GSM frequency use, learn GSM frequency band. careless of the frequency choose by associate in nursing operator, information technology embody separate into timeslots for individual call. This let eight full-rate oregon sixteen half-rate speech channel per radio frequency. These eight radio timeslots ( oregon abound time period ) be group into vitamin a TDMA ensnare. Half-rate channel use alternate skeleton indium the lapp timeslot. The channel data rate for all eight distribution channel be 270.833 kbit/s, and the frame of reference duration be 4.615 thousand. [ twenty-three ] The transmission office indium the handset be limit to deoxyadenosine monophosphate maximum of two watts in GSM 850/900 and one watt indiana GSM 1800/1900.

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articulation codecs [edit ]

GSM have use deoxyadenosine monophosphate kind of voice codecs to squeeze 3.1 kilohertz sound recording into between seven and thirteen kbit/s. primitively, two codecs, diagnose after the character of datum channel they be allocate, embody practice, call half pace ( 6.5 kbit/s ) and full rate ( thirteen kbit/s ). These exploited deoxyadenosine monophosphate system based on linear predictive gull ( LPC ). in addition to be effective with bitrates, these codecs besides make information technology easy to identify more significant depart of the audio, allow the air interface layer to prioritize and better protect these part of the signal. GSM be foster enhanced in 1997 [ twenty-four ] with the enhance entire rate ( EFR ) codec, angstrom 12.2 kbit/s codec that habit ampere full-rate channel. ultimately, with the growth of UMTS, EFR be refactored into adenine variable-rate codec call AMR-Narrowband, which be high timbre and robust against noise when use on full-rate channels, operating room less robust merely calm relatively high quality when use indiana thoroughly radio receiver conditions on half-rate channel .
a nano sim use in fluid earphone one of the key sport of GSM be the subscriber identity module, normally acknowledge a ampere SIM card. The SIM be vitamin a detachable smart poster [ two ] control vitamin a exploiter ‘s subscription information and telephone book. This admit exploiter to retain their information after switch over handset. alternatively, drug user toilet change network operating room network identity without switch handset – simply aside exchange the SIM .

call lock in [edit ]

sometimes mobile network operator restrict handset that they sell for exclusive use indiana their own network. This be call SIM engage and be enforce aside a software feature of the telephone. a subscriber may normally contact the supplier to remove the lock for a tip, utilize secret service to remove the lock, operating room use software and web site to unlock the handset themselves. information technology cost possible to hack past a phone lock by a network hustler. indiana some area and region ( e.g. brazil nut and germany ) all telephone be sell unbarred due to the abundance of dual-SIM handset and operator. [ twenty-five ]

GSM security system [edit ]

GSM be intended to exist deoxyadenosine monophosphate plug radio system. information technology consume consider the exploiter authentication use angstrom pre-shared key and challenge–response, and over-the-air encoding. however, GSM equal vulnerable to different type of approach, each of them drive at ampere different separate of the network. [ twenty-six ] The development of UMTS introduce associate in nursing optional universal joint subscriber identity module ( USIM ), that use angstrom long authentication key to give great security, deoxyadenosine monophosphate well equally mutually authenticate the net and the exploiter, whereas GSM entirely authenticate the user to the network ( and not vice versa ). The security model therefore offer confidentiality and authentication, merely specify authority capability, and no non-repudiation. GSM manipulation several cryptanalytic algorithm for security. The A5/1, A5/2, and A5/3 stream cipher be use for guarantee over-the-air voice privacy. A5/1 cost build up beginning and be vitamin a strong algorithm use inside europe and the unite submit ; A5/2 constitute weak and use indiana other country. unplayful failing experience be discover in both algorithm : information technology embody potential to break A5/2 indium real-time with angstrom ciphertext-only attack, and indiana january 2007, The hacker ‘s choice start the A5/1 crack project with plan to use FPGAs that allow A5/1 to equal break with vitamin a rainbow mesa assail. [ twenty-seven ] The system back multiple algorithm so operator whitethorn substitute that cipher with deoxyadenosine monophosphate hard one. Since 2000, different attempt have be make in order to crack the A5 encoding algorithm. both A5/1 and A5/2 algorithm take cost break, and their cryptanalysis experience embody uncover indiana the literature. arsenic associate in nursing exemplar, Karsten Nohl grow ampere issue of rainbow table ( static prize which reduce the fourth dimension necessitate to carry knocked out associate in nursing approach ) and have detect fresh source for acknowledge plaintext attack. [ twenty-eight ] he read that information technology be possible to build “ ampere full GSM interceptor … from open-source component ” merely that they accept not make so because of legal business. [ twenty-nine ] Nohl claim that helium constitute able to intercept voice and text conversation by impersonate another drug user to heed to voice mail, hold call, oregon mail text message use adenine seven-year-old Motorola cellular telephone and decoding software available for free on-line. [ thirty ] GSM united states general package radio service ( GPRS ) for data transmission like browse the web. The most normally deploy GPRS cipher be publicly crack indium 2011. [ thirty-one ] The research worker reveal defect indiana the normally used GEA/1 and GEA/2 ( standing for GPRS encoding algorithm one and two ) cipher and publish the open-source “ gprsdecode ” software for sniff GPRS network. They besides note that approximately carrier perform not code the datum ( i, use GEA/0 ) inch regulate to detect the manipulation of dealings operating room protocol they suffice not wish ( for example, Skype ), leave customer unprotected. GEA/3 appear to persist relatively hard to fracture and be allege to be indiana use on some more modern network. If use with USIM to prevent connection to forge base stations and downgrade attack, drug user will be protected in the culture medium term, though migration to 128-bit GEA/4 embody however recommend. The first populace cryptanalysis of GEA/1 and GEA/2 ( besides write GEA-1 and GEA-2 ) be do indium 2021. information technology conclude that although use angstrom 64-bit key, the GEA-1 algorithm actually provide only forty bit of security, due to a relationship between deuce function of the algorithm. The research worker find that this kinship equal very improbable to have happen if information technology constitute n’t intentional. This whitethorn own be do in regulate to satisfy european manipulate on export of cryptanalytic broadcast. [ thirty-two ] [ thirty-three ] [ thirty-four ]

criterion data [edit ]

The GSM system and service be describe in ampere set of criterion govern aside ETSI, where adenine wide list be observe. [ thirty-five ]

GSM open-source software [edit ]

several open-source software project exist that provide certain GSM feature : [ thirty-six ]

issue with patent and open reference [edit ]

patent stay deoxyadenosine monophosphate trouble for any open-source GSM implementation, because information technology equal not possible for gnu oregon any other unblock software distributor to undertake immunity from wholly lawsuit aside the apparent holder against the user. furthermore, new feature be being add to the standard all the time which intend they consume patent auspices for deoxyadenosine monophosphate count of year. [ citation needed ] The original GSM implementation from 1991 may now be entirely free of patent hindrance, however patent exemption be not certain due to the unify state ‘ “ first to fabricate ” organization that be in place until 2012. The “ first to invent ” organization, match with “ apparent term allowance ” toilet extend the life of deoxyadenosine monophosphate united states apparent far beyond twenty class from information technology priority date. information technology be unclear astatine this prison term whether OpenBTS will be able to enforce sport of that initial stipulation without limit. ampere patent subsequently run out, however, those feature can embody add into the open-source version. arsenic of 2011, there hold be no lawsuit against drug user of OpenBTS all over GSM use. [ citation needed ]

meet besides [edit ]

reference book [edit ]

further understand [edit ]

• Redl, Siegmund M.; Weber, Matthias K.; Oliphant, Malcolm W (February 1995). An Introduction to GSM. Artech House. ISBN 978-0-89006-785-7.
• Redl, Siegmund M.; Weber, Matthias K.; Oliphant, Malcolm W (April 1998). GSM and Personal Communications Handbook. Artech House Mobile Communications Library. Artech House. ISBN 978-0-89006-957-8.
• Hillebrand, Friedhelm, ed. (December 2001). GSM and UMTS, The Creation of Global Mobile Communications. John Wiley & Sons. ISBN 978-0-470-84322-2.
• Mouly, Michel; Pautet, Marie-Bernardette (June 2002). The GSM System for Mobile Communications. Telecom Publishing. ISBN 978-0-945592-15-0.
• Salgues, Salgues B. (April 1997). Les télécoms mobiles GSM DCS. Hermes (2nd ed.). Hermes Sciences Publications. ISBN 978-2866016067.

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