2G

  (Redirected from 2.5G)

2G (or 2-G) is short for second-generation cellular network. 2G cellular networks were commercially launched on the GSM standard in Finland by Radiolinja (now part of Elisa Oyj) in 1991.[1]

Three primary benefits of 2G networks over their 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.

2G technologies enabled the various networks to provide services such as text messages, picture messages, and MMS (multimedia messages).

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. Both systems use digital signaling to connect the radio towers (which listen to the devices) to the rest of the mobile system.

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

The most common 2G technology was the time division multiple access (TDMA)-based GSM, originally from Europe but used in most of the world outside Japan and North America. In North America, Digital AMPS (IS-54 and IS-136) and cdmaOne (IS-95) were the main systems. In Japan, the ubiquitously deployed system was Personal Digital Cellular (PDC).

EvolutionEdit

2.5G (GPRS)Edit

2.5G ("second and a half generation"[3]) is used to describe 2G-systems that have implemented a packet-switched domain in addition to the circuit-switched domain. It doesn't necessarily provide faster service because bundling of timeslots is used for circuit-switched data services (HSCSD) as well.

2.75G (EDGE)Edit

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.

Phase-outEdit

2G, understood as GSM and CDMA, has been superseded by newer technologies such as 3G (UMTS / CDMA2000), 4G (LTE) and 5G; however, 2G networks are still used in most parts of Europe, Africa, Central America and South America,[4][5][6] and many modern LTE-enabled devices are known to still fallback to 2G for phone calls, especially in rural areas.[7] In some places, its successor 3G is being shut down rather than 2G – Vodafone announced that it will switch off 3G across Europe in 2020 but retain 2G as a fallback service.[8]

Various carriers have made announcements that 2G technology in the United States, Japan, Australia, and other countries is in the process of being shut down, or have already shut down 2G services so that carriers can reclaim those radio bands and re-purpose them for newer technologies (e.g. 4G LTE).[9][10]

CriticismEdit

In some parts of the world, including the United Kingdom, 2G remains widely used for dumbphones, and for internet of things (IoT) devices where the high patent licensing cost of newer technologies makes them prohibitive, such as smart meters, eCall systems and vehicle tracking devices.[11][8][12] Terminating 2G services could leave vulnerable people who rely on 2G infrastructure without means to access emergency contacts, leading to preventable deaths.[12]

Past 2G networksEdit

Country Network Shutdown date Standard Notes
  Australia Optus 01.08.2017 GSM 2G shut down in WA and NT on 3 April 2017.[13][14]
Telstra 01.12.2016 GSM [15]
Vodafone 30.06.2018 GSM
  Canada Bell 30.04.2019 cdmaOne Shutdown of CDMA transmitters began in remote areas in 2017, followed by an official announcement in June 2018
that 2G devices will lose service soon.[16][17]
Rogers Wireless 31.12.2021 GSM Initially announced for 2018, the 2G network shut-down was later pushed back to 31 December 2020.
In July 2020 this date was postponed for another year.[18][19]
SaskTel 31.07.2017 cdmaOne [20][21]
Telus 31.05.2017 cdmaOne [22][23]
  China China Unicom 2021 GSM [24][25]
  Japan au KDDI 31.03.2008 cdmaOne
NTT Docomo 31.03.2012 PDC [26]
Softbank 31.03.2010 PDC [27]
  Macau China Telecom 2010 cdmaOne [28]
CTM 01.08.2019 GSM Service for local customers terminated on 4 June 2015 with network service remaining for roaming users.[29][28]
3 01.08.2019 GSM Service for local customers terminated on 4 June 2015 with network service remaining for roaming users.[29][28]
SmarTone 01.08.2019 GSM Service for local customers terminated on 4 June 2015 with network service remaining for roaming users.[29][28]
  Mexico AT&T since Q1 2019 GSM [30]
Movistar 01.01.2021 GSM [31]
  Netherlands T-Mobile 01.06.2021 /
15.11.2023 (IoT)
GSM [32]
  New Zealand 2degrees 15.03.2018 GSM [33]
Spark 31.07.2012 cdmaOne [34][35]
  Singapore M1 18.04.2017 GSM [36]
Singtel 18.04.2017 GSM [36]
StarHub 18.04.2017 GSM [36]
  South Korea KT 19.03.2012 cdmaOne CDMA2000 1xRTT, EV-DO Rel. 0 (3G) service has also terminated.[37]
LG Uplus 30.06.2021 cdmaOne CDMA2000 1xRTT, EV-DO Rev. A/B (3G) service will also terminate.[38]
SK Telecom 27.07.2020 cdmaOne CDMA2000 1xRTT, EV-DO Rel. 0 (3G) service has also terminated.[39]
   Switzerland Salt since 01.07.2020 GSM As of December 2020 network coverage almost completely vanished with single sites in remote areas remaining
until local 4G coverage becomes available.[40][41][42]
Sunrise 31.12.2022 GSM Originally announced for the end of 2018, with the introduction of S-RAN phaseout was postponed to 2022.[43][44][45]
Swisscom 15.04.2021 GSM Official shutdown date was on 31.12.2020 (service guarantee)[46][47]
  Taiwan Chunghwa Telecom 30.06.2017 GSM [48]
FarEasTone 30.06.2017 GSM [48]
Taiwan Mobile 30.06.2017 GSM [48]
  United States AT&T 01.01.2017 GSM [49]
T-Mobile 31.12.2022 GSM [50]
T-Mobile (Sprint) 01.01.2022 cdmaOne CDMA2000 1xRTT, EV-DO Rev. A (3G) service will also terminate.[51][50]
Verizon 31.12.2022 cdmaOne CDMA2000 1xRTT, EV-DO Rev. A (3G) service will also terminate.[52]

See alsoEdit

ReferencesEdit

  1. ^ "Radiolinja's History". 20 April 2004. Archived from the original on 23 October 2006. Retrieved 23 December 2009.
  2. ^ a b "GPRS & EDGE". 3gpp.org. Retrieved 17 August 2019.
  3. ^ "What is Second and a Half Generation (2.5G) | IGI Global". www.igi-global.com. Retrieved 6 October 2019.
  4. ^ "Germany's rural 4G users still spend one-fourth of their time on 3G and 2G networks". Opensignal. 13 June 2019. Retrieved 6 October 2019.
  5. ^ "T-Mobile Poland expects to keep 2G for five-to-six years". TeleGeography A. Division of PriMetrica. 17 July 2019. Retrieved 6 October 2019.
  6. ^ "2G phase-out – modernisation of the Swisscom mobile network | Swisscom". www.swisscom.ch. Retrieved 6 October 2019.
  7. ^ "SUNSET ON 2G/3G MOBILE NETWORKS? NOT EXACTLY..." CSL Group.
  8. ^ a b Hall, Kat. "Sod 3G, that can go, but don't rush to turn off 2G, UK still needs it – report". www.theregister.com.
  9. ^ Serr, Melanie (5 April 2017). "What You Need To Know About the 2G Network Shutdown". Geotab Blog. Retrieved 6 October 2019.
  10. ^ "The status of the 2G/3G network sunset". nae_ global. 31 July 2019. Retrieved 11 December 2019.
  11. ^ "Freedom of Information: Right to know request" (PDF). www.ofcom.org.uk. 3 June 2020. Retrieved 27 November 2020.
  12. ^ a b Rockman, Simon. "Millions Will Lose Out When Government Kills 2G". Forbes.
  13. ^ "Optus to shutter GSM network in April 2017". TeleGeography. 5 August 2015. Retrieved 23 January 2021.
  14. ^ "2G Network Closure Update". Optus. 19 October 2016. Retrieved 6 July 2017.
  15. ^ "Telstra switches off GSM network". TeleGeography. 2 December 2016. Retrieved 23 January 2021.
  16. ^ "CDMA Network Discontinuation". Bell Canada. Retrieved 23 January 2021.
  17. ^ "Bell completing CDMA shutdown on 30 April". TeleGeography. 1 April 2019. Retrieved 23 January 2021.
  18. ^ "Rogers extends availability of GSM/GPRS network to December 2020". MobileSyrup. 4 May 2018. Retrieved 23 January 2021.
  19. ^ "Important Notice Regarding Upcoming 2G/3G Changes on the Rogers Network". BULWARK. 15 July 2020. Retrieved 23 January 2021.
  20. ^ "Final countdown for Saskatchewan CDMA". TeleGeography. 6 July 2016. Retrieved 23 January 2021.
  21. ^ "SaskTel reminds CDMA customers of network shutdown". Sasktel. 11 January 2017. Retrieved 23 January 2021.
  22. ^ "Telus 'shutting CDMA in 2015'". TeleGeography. 21 October 2013. Retrieved 23 January 2021.
  23. ^ "CDMA network shut down - Information on the discontinuation of CDMA network support". TELUS. Retrieved 23 January 2021.
  24. ^ "China Unicom to retire 2G next year". Developing Telecoms Ltd. 13 November 2020. Retrieved 23 January 2021.
  25. ^ "China Unicom to Shut All 2G Networks by 2021 to Cut Costs". Yicai Global. 13 November 2020. Retrieved 23 January 2021.
  26. ^ "DoCoMo's nine-month profits up 16%, announces 2G shutdown March 2012". TeleGeography. 30 January 2009. Retrieved 23 January 2021.
  27. ^ "Discontinuation Notice of 2G Service". Softbank. 24 November 2009. Retrieved 23 January 2021.
  28. ^ a b c d "Macau to shut down 2G networks for roaming users". TeleGeography. 10 April 2019. Retrieved 23 January 2021.
  29. ^ a b c "Macau mobile users reach 1.56m in 3Q13; 2G users number less than 5,000 as switch off looms". TeleGeography. 29 October 2013. Retrieved 23 January 2021.
  30. ^ "AT&T Mexico 2G switch-off imminent, report says". TeleGeography. 16 January 2019. Retrieved 14 April 2021.
  31. ^ "Movistar Mexico to switch off 2G on 1 January 2021". TeleGeography. 9 October 2020. Retrieved 14 April 2021.
  32. ^ "T-Mobile Netherlands delays consumer 2G shutdown to Jun-21; M2M 2G continues to Jun-23". TeleGeography. 9 October 2020. Retrieved 23 January 2021.
  33. ^ "2degrees 2G shuts on 15 March". TeleGeography. 13 February 2018. Retrieved 23 January 2021.
  34. ^ "Telecom NZ to close CDMA network by mid-2012". TeleGeography. 8 July 2010. Retrieved 23 January 2021.
  35. ^ "Telecom closes CDMA network". TeleGeography. 31 July 2012. Retrieved 23 January 2021.
  36. ^ a b c "IMDA: 2G shutdown will start on 1 April". TeleGeography. 28 March 2017. Retrieved 23 January 2021.
  37. ^ "Terminating 2G Service in Korea: Policy Issues and Suggestions". International Telecommunications Policy Review. 1 March 2014. Retrieved 23 January 2021.
  38. ^ "S. Korea to end 2G network services by June". The Korea Herald. 17 January 2021. Retrieved 23 January 2021.
  39. ^ "SK Telecoms shutters 2G service". TeleGeography. 28 July 2020. Retrieved 23 January 2021.
  40. ^ "Salt und Swisscom besiegeln das Aus für Uralt-Handys – 2020 wird das 2G-Netz abgeschaltet" (in German). watson. 7 April 2017. Retrieved 23 January 2021.
  41. ^ "Fragwürdiges Angebot - Trotz Netz-Abschaltung sind noch 2G-Handys im Handel" (in German). SRF. 23 July 2020. Retrieved 23 January 2021.
  42. ^ "Schweiz: GSM-Netz bei Salt noch nicht ganz weg" (in German). Teltarif.de. 23 June 2020. Retrieved 23 January 2021.
  43. ^ "Sun sets on 2G technology for Swiss cellco". TeleGeography. 20 June 2017. Retrieved 23 January 2021.
  44. ^ "Schweiz: Sunrise schaltet 2G vorerst doch nicht ab" (in German). Teltarif.de. 23 November 2018. Retrieved 14 April 2021.
  45. ^ "Abschaltung: Die Tage von GSM sind in der Schweiz gezählt" (in German). Teltarif.de. 20 June 2020. Retrieved 23 January 2021.
  46. ^ "Swisscom plots the end of 2G as it moves to launch 5G in 2020". Fierce Wireless. 9 October 2016. Retrieved 23 January 2021.
  47. ^ "Swisscom schaltet GSM-Netz komplett ab" (in German). Teltarif.de. 13 April 2021. Retrieved 14 April 2021.
  48. ^ a b c "Taiwanese cellcos shutter 2G networks". TeleGeography. 3 July 2017. Retrieved 23 January 2021.
  49. ^ "AT&T confirms 2G shutdown took place on 1 January". TeleGeography. 18 January 2017. Retrieved 23 January 2021.
  50. ^ a b "T-Mobile's 2G, 3G shutdown dates leaked". TeleGeography. 8 February 2021. Retrieved 14 April 2021.
  51. ^ "T-Mobile aiming to shut down legacy Sprint networks in 2022". TeleGeography. 10 December 2020. Retrieved 23 January 2021.
  52. ^ "Verizon to shut down 3G CDMA networks on 31 December 2022". TeleGeography. 31 March 2021. Retrieved 14 April 2021.
Preceded by
1st Generation (1G)
Mobile Telephony Generations Succeeded by
3rd Generation (3G)