Английская Википедия:2G

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2G is a short notation for second-generation cellular network, a group of technology standards employed for cellular networks. 2G was commercially launched on the GSM standard in Finland by Radiolinja (now part of Elisa Oyj) in 1991.[1] After 2G was launched, the previous mobile wireless network systems were retroactively dubbed 1G. While radio signals on 1G networks are analog, radio signals on 2G networks are digital, though both systems use digital signaling to connect cellular radio towers to the rest of the mobile network system. 2G was superseded by 3G technology.

The most common 2G technology was the time-division multiple access (TDMA)-based GSM standard, used in most of the world outside Japan.Шаблон:Citation needed In North America, Digital AMPS (IS-54 and IS-136) and cdmaOne (IS-95) were dominant, but GSM was also used.[2]Шаблон:Citation needed In Japan the ubiquitous system was Personal Digital Cellular (PDC) though another, Personal Handy-phone System (PHS), also existed.Шаблон:Citation needed

Three primary benefits of 2G networks over their 1G predecessors were:

  1. Digitally encrypted phone conversations, at least between the mobile phone and the cellular base station but not necessarily in the rest of the network.
  2. Significantly more efficient use of the radio frequency spectrum enabling more users per frequency band.
  3. Data services for mobile, starting with SMS text messages then expanding to Multimedia Messaging Service (MMS).

With General Packet Radio Service (GPRS), 2G offers a theoretical maximum transfer speed of 40 kbit/s (5 kB/s).[3] With EDGE (Enhanced Data Rates for GSM Evolution), there is a theoretical maximum transfer speed of 384 kbit/s (48 kB/s).[3]

Evolution

Файл:Cellular network standards and generation timeline.svg
Cellular network standards and generation timeline.

2.5G (GPRS)

2.5G ("second and a half generation"[4]) is used to describe 2G-systems that have implemented a packet-switched domain in addition to the circuit-switched domain. It does not necessarily provide faster service because bundling of timeslots is used for circuit-switched data services (HSCSD) as well.

2.75G (EDGE)

GPRS networks evolved to EDGE networks with the introduction of 8PSK encoding. While the symbol rate remained the same at 270.833 samples per second, each symbol carried three bits instead of one. Enhanced Data rates for GSM Evolution (EDGE), Enhanced GPRS (EGPRS), or IMT Single Carrier (IMT-SC) is a backward-compatible digital mobile phone technology that allows improved data transmission rates, as an extension on top of standard GSM. EDGE was deployed on GSM networks beginning in 2003, initially by AT&T in the United States.


2.875G (EDGE Evolution)

Phase-out

Шаблон:See also 2G, understood as GSM and CdmaOne, has been superseded by newer technologies such as 3G (UMTS / CDMA2000), 4G (LTE / WiMAX) and 5G (5G NR). However, 2G networks were still available Шаблон:As of in most parts of the world, while notably excluding the majority of carriers in North America, East Asia, and Australasia.[5][6][7]

Many modern LTE-enabled devices have the ability to fall back to 2G for phone calls, necessary especially in rural areas where later generations have not yet been implemented.[8] In some places, its successor 3G is being shut down rather than 2G – Vodafone previously announced that it had switched off 3G across Europe in 2020 but still retains 2G as a fallback service.[9] In the US T-Mobile shut down their 3G services while retaining their 2G GSM network.[10][11]

Various carriers have made announcements that 2G technology in the United States, Japan, Australia, and other countries are in the process of being shut down, or have already shut down 2G services so that carriers can re-use the frequencies for newer technologies (e.g. 4G, 5G).[12][13]

In 2022, Android 12 introduced a system setting to disable 2G connectivity for the device, as 2G is considered to be insecure.[14] Specifically, there exist well known methods to attack weaknesses in GSM since 2009[15] with practical use in crime.[16] Attack routes on 2G CdmaOne were found later and remain less publicized.[17]

Criticism

In some parts of the world, including the United Kingdom, 2G remains widely used for older feature phones and for internet of things (IoT) devices such as smart meters, eCall systems and vehicle trackers to avoid the high patent licensing cost of newer technologies.[18] Terminating 2G services could leave vulnerable people who rely on 2G infrastructure unable to communicate even with emergency contacts, causing harm and possibly deaths.[19]

Past 2G networks

Country Network Shutdown date Standard Notes
Шаблон:Flag Ålcom Шаблон:Fontcolour GSM 2G availability cannot be guaranteed after 1 Jan 2022, all stations are planned to be shut down in 2024.[20]
Шаблон:Flag Optus 2017-08-01 GSM 2G shut down in WA and NT on 03 Apr 2017.[21][22]
Telstra 2016-12-01 GSM [23]
Vodafone 2018-06-30 GSM
Шаблон:Flag Batelco 2021-11-30 GSM [24]
Шаблон:Flag Orange Шаблон:Fontcolour GSM [25]
Telenet Шаблон:Fontcolour GSM [26]
Proximus Шаблон:Fontcolour GSM [27]
Шаблон:Flag DSTCom 2021-06-01 GSM [28][29]
Progresif 2021-06-01 GSM [28][29]
imagine 2021-06-01 GSM [28][29]
Шаблон:Flag Bell 2019-04-30 cdmaOne Shutdown of CDMA transmitters commenced in remote areas in 2017, followed by an official announcement in June 2018 that 2G devices will lose service soon.[30][31]
Rogers Wireless GSM Шаблон:Fontcolour
850 MHz remains active.[32][33][34][35]
SaskTel 2017-07-31 cdmaOne [36][37]
Telus Mobility 2017-05-31 cdmaOne [38][39]
Шаблон:Flag Digicel 2020-07-01 GSM [40][41]
Шаблон:Flag China Unicom GSM Шаблон:Fontcolour[42][43][44]
China Telecom Шаблон:Fontcolour cdmaOne Шаблон:Fontcolour
CDMA2000 1xRTT, EV-DO Rev. A/B (3G) service also terminates.[45][46]
Шаблон:Flag Claro 2023-02-23 GSM [47][48]
Tigo 2022-11-01 GSM [49]
Шаблон:Flag Bouygues Шаблон:Fontcolour GSM [50]
Orange Шаблон:Fontcolour GSM [25]
SFR Шаблон:Fontcolour GSM [51]
Шаблон:Flag 3 2021-09-30 GSM [52]
SmarTone 2022-10-14 GSM [53]
Шаблон:Flag Шаблон:Fontcolour GSM per government statement[54]
Шаблон:Flag Шаблон:Fontcolour GSM per government statement[55]
Шаблон:Flag FLOW 2022-09-30 GSM [56][57]
Шаблон:Flag au KDDI 2008-03-31 cdmaOne
NTT Docomo 2012-03-31 PDC [58]
Softbank 2010-03-31 PDC [59]
Шаблон:Flag Umniah Шаблон:Fontcolour GSM [60]
Шаблон:Flag Orange Шаблон:Fontcolour GSM [25]
Шаблон:Flag China Telecom Шаблон:Fontcolour cdmaOne [61]
CTM 2019-08-01 GSM Service for local customers terminated on 04 Jun 2015 with service remaining for roaming users.[62][61]
3 2019-08-01 GSM Service for local customers terminated on 04 Jun 2015 with service remaining for roaming users.[62][61]
SmarTone 2019-08-01 GSM Service for local customers terminated on 04 Jun 2015 with service remaining for roaming users.[62][61]
Шаблон:Flag AT&T GSM Шаблон:Fontcolour[63]
Movistar 2021-01-01 GSM [64]
Шаблон:Flag T-Mobile 2021-06-01 /
2023-11-15 (IoT)
GSM [65]
Шаблон:Flag OPT-NC Шаблон:Fontcolour GSM Шаблон:Fontcolour[66]
Шаблон:Flag 2degrees 2018-03-15 GSM [67]
Spark 2012-07-31 cdmaOne [68][69]
Шаблон:Flag Telenor Шаблон:Fontcolour GSM [70]
Telia Шаблон:Fontcolour GSM [70]
Шаблон:Flag Orange Шаблон:Fontcolour GSM [25]
Шаблон:Flag Orange Шаблон:Fontcolour GSM [25]
Шаблон:Flag FLOW 2023-09-30 GSM [71][72]
Шаблон:Flag M1 2017-04-18 GSM [73]
Singtel 2017-04-18 GSM [73]
StarHub 2017-04-18 GSM [73]
Шаблон:Flag TelCell 2019-01-01 GSM [74]
UTS 2017-09-26 GSM [75]
Шаблон:Flag Orange Шаблон:Fontcolour GSM [25]
Шаблон:Flag Шаблон:Fontcolour GSM per government statement[76][77]
Шаблон:Flag KT 2012-03-19 cdmaOne CDMA2000 1xRTT, EV-DO Rel. 0 (3G) service has also terminated.[78]
LG Uplus 2021-06-30 cdmaOne CDMA2000 1xRTT, EV-DO Rev. A/B (3G) service has also terminated.[79]
SK Telecom 2020-07-27 cdmaOne CDMA2000 1xRTT, EV-DO Rel. 0 (3G) service has also terminated.[80]
Шаблон:Flag Orange Шаблон:Fontcolour GSM [25]
Шаблон:Flag Salt 2020-12-31 GSM [81][82][83]
Shutdown commenced on 01 Jul 2020. A few single 2G-only sites remained until Sep 2023 to preserve CSFB functionality.
Sunrise 2023-01-03 GSM [84][85][86]
With the introduction of S-RAN in 2018 phaseout was postponed to 2022.
Swisscom 2021-04-07 GSM [87][88][89]
Official shutdown date was on 31 Dec 2020 (guaranteed availability).
Шаблон:Flag Chunghwa Telecom 2017-06-30 GSM [90]
FarEasTone 2017-06-30 GSM [90]
Taiwan Mobile 2017-06-30 GSM [90]
Шаблон:Flag Digicel Шаблон:Fontcolour GSM [91][92]
Шаблон:Flag Du Шаблон:Fontcolour GSM [93]
Etisalat Шаблон:Fontcolour GSM [94]
Шаблон:Flag Шаблон:Fontcolour GSM per government statement on confirmation by mobile providers[95][96][97]
Шаблон:Flag
Шаблон:Flag
Шаблон:Flag
AT&T 2017-01-01 GSM [98]
Cellcom 2023-12-01 cdmaOne CDMA2000 1xRTT, EV-DO Rev. A (3G) service has also terminated.
[99]
T-Mobile Шаблон:Fontcolour GSM [100]
T-Mobile (Sprint) 2022-05-31 cdmaOne CDMA2000 1xRTT, EV-DO Rev. A (3G) service has also terminated.
Shutdown commenced on 31 Mar 2022.[101][102][103][104]
Union Wireless 2015 GSM [105]
UScellular Шаблон:Fontcolour cdmaOne CDMA2000 1xRTT, EV-DO Rev. A (3G) service will also terminate.
[106][107]
Verizon 2022-12-31 cdmaOne CDMA2000 1xRTT, EV-DO Rev. A (3G) service also terminated.[108]
Шаблон:Flag Digitel Шаблон:Fontcolour GSM Шаблон:Fontcolour
[109]
Movilnet Шаблон:Fontcolour GSM [109]
Movistar Шаблон:Fontcolour GSM Шаблон:Fontcolour
[109]
Шаблон:Flag GSM per government statement[110]
Shutdown commenced in Dec 2023.[111]
Шаблон:Fontcolour[112]
Шаблон:Fontcolour[113]

See also

References

Шаблон:Reflist

Шаблон:S-start Шаблон:S-bef Шаблон:S-ttl Шаблон:S-aft Шаблон:S-end

Шаблон:Mobile telecommunications standards Шаблон:Mobile phones

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