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both systems use digital signaling to connect cellular radio towers to the rest of the mobile network system. 2G was superseded by 3G technology.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.^{[citation needed]} In North America, Digital AMPS (IS-54 and IS-136) and cdmaOne (IS-95) were dominant, but GSM was also used.^{[2][citation needed]} In Japan the ubiquitous system was Personal Digital Cellular (PDC) though another, Personal Handy-phone System (PHS), also existed.^{[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

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

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 as of 2023^[update] 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

Zdroj:https://en.wikipedia.org?pojem=2.75G
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Country	Network	Shutdown date	Standard	Notes
Åland	Ålcom	2024	GSM	2G availability cannot be guaranteed after 1 Jan 2022, all stations are planned to be shut down in 2024.[20]
Australia	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
Bahrain	Batelco	2021-11-30	GSM	[24]
Belgium	Orange	2030	GSM	[25]
	Telenet	2027	GSM	[26]
	Proximus	2027	GSM	[27]
Brunei	DSTCom	2021-06-01	GSM	[28][29]
	Progresif	2021-06-01	GSM	[28][29]
	imagine	2021-06-01	GSM	[28][29]
Canada	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	1900 MHz shutdown in Jun 2021. 850 MHz remains active.[32][33][34][35]
	SaskTel	2017-07-31	cdmaOne	[36][37]
	Telus Mobility	2017-05-31	cdmaOne	[38][39]
Cayman Islands	Digicel	2020-07-01	GSM	[40][41]
China	China Unicom		GSM	Local shutdown commenced in Q1 2021.[42][43][44]
	China Telecom	2025	cdmaOne	Local shutdown commenced on 16 Jun 2020. CDMA2000 1xRTT, EV-DO Rev. A/B (3G) service also terminates.[45][46]
Colombia	Claro	2023-02-23	GSM	[47][48]
	Tigo	2022-11-01	GSM	[49]
France	Bouygues	2026-12-31	GSM	[50]
	Orange	2025-12-31	GSM	[25]
	SFR	2026	GSM	[51]
Hong Kong	3	2021-09-30	GSM	[52]
	SmarTone	2022-10-14	GSM	[53]
Iceland		2025	GSM	per government statement[54]
Israel		2025	GSM	per government statement[55]
Italy	TIM Group	2029-12-31	GSM	[56][57][58]
	Vodafone Italia	2025-12-31	GSM	[59][60]
Jamaica	FLOW	2024-04-15	GSM	Shutdown commenced on September 30, 2022. [61][62][63]
	Digicel	2024-08-31	GSM	[64][63]
Japan	au KDDI	2008-03-31	cdmaOne
	NTT Docomo	2012-03-31	PDC	[65]
	Softbank	2010-03-31	PDC	[66]
Jordan	Umniah	2022-??-??	GSM	[67]
Luxembourg	Orange	2030	GSM	[25]
Macau	China Telecom	2010-??-??	cdmaOne	[68]
	CTM	2019-08-01	GSM	Service for local customers terminated on 04 Jun 2015 with service remaining for roaming users.[69][68]
	3	2019-08-01	GSM	Service for local customers terminated on 04 Jun 2015 with service remaining for roaming users.[69][68]
	SmarTone	2019-08-01	GSM	Service for local customers terminated on 04 Jun 2015 with service remaining for roaming users.[69][68]
Mexico	AT&T		GSM	Local shutdown commenced in Q1 2019.[70]
	Movistar	2021-01-01	GSM	[71]
Netherlands	T-Mobile	2021-06-01 / 2023-11-15 (IoT)	GSM	[72]
New Caledonia	OPT-NC	2025	GSM	Shutdown commenced in 2022.[73]
New Zealand	2degrees	2018-03-15	GSM	[74]
	Spark	2012-07-31	cdmaOne	[75][76]
Norway	Telenor	2025	GSM	[77]
	Telia	2025	GSM	[77]
Poland	Orange	2030	GSM	[25]
Romania	Orange	2030	GSM	[25]
Saint Vincent and the Grenadines	FLOW	2023-09-30	GSM	[78][79]
Singapore	M1	2017-04-18	GSM	[80]
	Singtel	2017-04-18	GSM	[80]
	StarHub	2017-04-18	GSM	[80]
Sint Maarten	TelCell	2019-01-01	GSM	[81]
	UTS	2017-09-26	GSM	[82]
Slovakia	Orange	2030	GSM	[25]
South Africa		2024-06-30	GSM	per government statement[83][84]
South Korea	KT	2012-03-19	cdmaOne	CDMA2000 1xRTT, EV-DO Rel. 0 (3G) service has also terminated.[85]
	LG Uplus	2021-06-30	cdmaOne	CDMA2000 1xRTT, EV-DO Rev. A/B (3G) service has also terminated.[86]
	SK Telecom	2020-07-27	cdmaOne	CDMA2000 1xRTT, EV-DO Rel. 0 (3G) service has also terminated.[87]
Spain	Orange	2030	GSM	[25]
Switzerland	Salt	2020-12-31	GSM	[88][89][90] 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	[91][92][93] With the introduction of S-RAN in 2018 phaseout was postponed to 2022.
	Swisscom	2021-04-07	GSM	[94][95][96] Official shutdown date was on 31 Dec 2020 (guaranteed availability).
Taiwan	Chunghwa Telecom	2017-06-30	GSM	[97]
	FarEasTone	2017-06-30	GSM	[97]
	Taiwan Mobile	2017-06-30	GSM	[97]
Trinidad and Tobago	Digicel	2024-12-31	GSM	[98][99][100]
United Arab Emirates	Du	2023-12-31	GSM	[101]
	Etisalat	2023-12-31	GSM	[102]
United Kingdom		2033	GSM	per government statement on confirmation by mobile providers[103][104][105]
United States  Puerto Rico  US Virgin Islands	AT&T	2017-01-01	GSM	[106]
	Cellcom	2023-12-01	cdmaOne	CDMA2000 1xRTT, EV-DO Rev. A (3G) service has also terminated. [107]
	Commnet Wireless (Choice)	2022-12-31	cdmaOne	CDMA2000 1xRTT, EV-DO Rev. A (3G) service has also terminated. [108]
	Copper Valley Wireless	2022-09-30	cdmaOne