CDMA2000

{{Short description|Family of 3G mobile technology standards}} {{About|the mobile phone technology|the channel access method|Code-division multiple access}} {{Use mdy dates|date=November 2014}}

[[File:Huawei EC226 with USB cable (3384718751).jpg|thumb|Huawei CDMA2000 EVDO USB wireless modem (2009)]]

'''CDMA2000''' (also known as '''C2K''' or '''IMT Multi‑Carrier''' ('''IMT‑MC''')) is a family of 3G<ref>{{cite web | url = http://www.itu.int/ITU-D/imt-2000/DocumentsIMT2000/What_really_3G.pdf | title = What really is a Third Generation (3G) Mobile Technology | access-date = October 28, 2012 | publisher = International Telecommunication Union | archive-url = https://web.archive.org/web/20110607105523/http://www.itu.int/ITU-D/imt-2000/DocumentsIMT2000/What_really_3G.pdf | archive-date = June 7, 2011 }}</ref> mobile technology standards for sending voice, data, and signaling data between mobile phones and cell sites. It is developed by 3GPP2 as a backwards-compatible successor to second-generation cdmaOne (IS-95) set of standards and used especially in North America and South Korea.

CDMA2000 compares to UMTS, a competing set of 3G standards, which is developed by 3GPP and used in Europe, Japan, China, and Singapore.

The name CDMA2000 denotes a family of standards that represent the successive, evolutionary stages of the underlying technology. These are: *Voice: CDMA2000 1xRTT, 1X Advanced *Data: CDMA2000 1xEV-DO (Evolution-Data Optimized): Release 0, Revision A, Revision B, Ultra Mobile Broadband (UMB)

All are approved radio interfaces for the ITU's IMT-2000. In the United States, ''CDMA2000'' is a registered trademark of the Telecommunications Industry Association (TIA-USA).<ref>[http://tess2.uspto.gov/bin/showfield?f=doc&state=4001:kets67.2.3 CDMA2000 trademark application] {{Webarchive|url=https://web.archive.org/web/20170113010120/http://tess2.uspto.gov/bin/showfield?f=doc&state=4001:kets67.2.3 |date=January 13, 2017 }}, uspto.gov, November 17, 2009</ref>

As of 2025, almost all public CDMA2000 networks have been shut down, usually to be replaced by LTE networks.

==1X== {{List of mobile phone generations}} '''CDMA2000 1X (IS-2000)''', also known as '''1x''' and '''1xRTT''', is the core CDMA2000 wireless air interface standard. The designation "1x", meaning ''1 times radio transmission technology'', indicates the same radio frequency (RF) bandwidth as IS-95: a duplex pair of 1.25 MHz radio channels. 1xRTT almost doubles the capacity of IS-95 by adding 64 more traffic channels to the forward link, orthogonal to (in quadrature with) the original set of 64. The 1X standard supports packet data speeds of up to 153 kbit/s with real world data transmission averaging 80–100 kbit/s in most commercial applications.<ref>{{cite web|url=http://www.cdg.org/technology/cdma20001x.asp|title=CDG : Technology : CDMA2000 1X|website=CDMA Development Group|access-date=July 28, 2017|archive-date=August 2, 2010|archive-url=https://web.archive.org/web/20100802011151/http://www.cdg.org/technology/cdma20001x.asp|url-status=dead}}</ref> IMT-2000 also made changes to the data link layer for greater use of data services, including medium and link access control protocols and quality of service (QoS). The IS-95 data link layer only provided best-effort delivery for data and circuit switched channel for voice (i.e., a voice frame once every 20 ms).

==1xEV-DO== {{Main|Evolution-Data Optimized}}[[File:1XEV_Mobile_Phone_Screenshot_blackberry.png|thumb|BlackBerry smartphone displaying '1XEV' as the service status in the upper right corner (2011)]] '''CDMA2000 1xEV-DO (Evolution-Data Optimized)''', often abbreviated as '''EV-DO''' or '''EV''', is a telecommunications standard for the wireless transmission of data through radio signals, typically for broadband Internet access. It uses multiplexing techniques including code-division multiple access (CDMA) as well as time-division multiple access to maximize both individual user's throughput and the overall system throughput. It is standardized (IS-856) by 3rd Generation Partnership Project 2 (3GPP2) as part of the CDMA2000 family of standards and has been adopted by many mobile phone service providers around the world – particularly those previously employing CDMA networks.

==1X Advanced== 1X Advanced (Rev.E)<ref>{{cite web|url=https://www.cdg.org/news/events/webinar/100513_cdma450_operators/2-ALU-Newbury%20450%20Webinar_3.pdf|title=Evolution of CDMA Roadmap—Voice Perspective|publisher=Alcatel-Lucent|date=May 13, 2010|access-date=May 17, 2016|archive-date=October 5, 2016|archive-url=https://web.archive.org/web/20161005115836/https://www.cdg.org/news/events/webinar/100513_cdma450_operators/2-ALU-Newbury%20450%20Webinar_3.pdf|url-status=dead}}</ref><ref>{{cite web|url=http://www.3gpp2.org/Public_html/specs/C.S0099-0_v2.0_Guidelines%20for%20using%20cdma2000%201x%20Revision%20E%20Features%20on%20Earlier%20Revisions_20110819.pdf|title=Guidelines for using cdma2000 1x Revision E Features on Earlier Revisions|publisher=3GPP2|date=July 2011|access-date=May 17, 2016|archive-url=https://web.archive.org/web/20160705073206/http://www.3gpp2.org/Public_html/specs/C.S0099-0_v2.0_Guidelines%20for%20using%20cdma2000%201x%20Revision%20E%20Features%20on%20Earlier%20Revisions_20110819.pdf|archive-date=July 5, 2016|url-status=dead|df=mdy-all}}</ref> is the evolution of CDMA2000 1X. It provides up to four times the capacity and 70% more coverage compared to 1X.<ref>{{cite web|url=http://www.qualcomm.com/solutions/wireless-networks/technologies/1x-advanced|title=1X Advanced|publisher=Qualcomm|access-date=September 18, 2013|archive-date=July 12, 2014|archive-url=https://web.archive.org/web/20140712002148/http://www.qualcomm.com/solutions/wireless-networks/technologies/1x-advanced|url-status=live}}</ref>

==Networks== {{See also|List of CDMA2000 networks}} The CDMA Development Group states that, as of April 2014, there are 314 operators in 118 countries offering CDMA2000 1X and/or 1xEV-DO service.<ref>{{cite web |url=https://www.cdg.org/resources/cdma_stats.asp |title=CDG : CDMA Statistics |publisher=CDMA Development Group |access-date=June 13, 2015 |archive-date=September 27, 2018 |archive-url=https://web.archive.org/web/20180927201826/http://cdg.org/resources/cdma_stats.asp |url-status=dead }}</ref>{{Update inline|date=August 2020}}

As of 2025, only very few active networks remain, with most of them being private networks maintained for machine to machine communication for specific critical infrastructure.

== Access authentication in CDMA networks == Access authentication in CDMA networks for telecommunications and computing provide network access for a mobile device. Specific methods such as CAVE-based Authentication (IS-95/1xRTT), and A12 Authentication (1xEV-DO) are possible. The serving network provides the mobile device access authentication mechanism.<ref>{{Cite web |author=Authority Hub-Where Authentication Meets Artistry |title=Unlocking the Secrets of CDMA Subscriber Identity Module |url=https://mojoauth.com/ciam-101/cdma-subscriber-identity-module |access-date=2025-10-13 |website=Authority Hub - Where Authentication Meets Artistry |language=en}}</ref><ref>{{Cite web |title=CDMA Network Technology: A Decade Of Advances And Challenges |url=https://www.tek.com/en/documents/technical-brief/cdma-network-technology-decade-advances-and-challenges |access-date=2025-10-13 |website=www.tek.com |language=en}}</ref> The exact method employed depends upon the type of service being used:

* CAVE-based Authentication – Used for access authentication in CDMA/1xRTT * AKA – 3G successor to CAVE-based authentication * A12 Authentication – Used for access authentication in 1xEV-DO

1xEV-DO Hybrid MS/AT devices may employ both CAVE-based and A12 authentication since these devices connect to both the 1xRTT and 1xEV-DO networks.

==History== {{Expand section|date=March 2011}}

CDMA2000 technology was developed by Qualcomm in the late 1990s as an enhancement to the cdmaOne standard.

The intended 4G successor to CDMA2000 was UMB (Ultra Mobile Broadband); however, in November 2008, Qualcomm announced it was ending development of the technology, favoring LTE instead.<ref>{{cite web |url=https://www.reuters.com/article/marketsNews/idUSN1335969420081113?rpc=401& |title=Qualcomm halts UMB project, sees no major job cuts |archive-url=https://web.archive.org/web/20090414175331/http://www.reuters.com/article/marketsNews/idUSN1335969420081113?rpc=401& |archive-date=April 14, 2009 |url-status=live |website=Reuters |date=November 13, 2008}}</ref>

In the USA, the last CDMA2000 network was shut down in 2024.<ref>{{Cite web |last=Zeman |first=Benjamin |date=2024-04-26 |title=What the heck happened to CDMA networks? |url=https://www.androidpolice.com/what-happened-to-cdma-networks/ |access-date=2025-09-25 |website=Android Police |language=en}}</ref>

== Patent licensing == In 2007, Qualcomm provided a global patent license for CDMA2000 to the Chinese company Teleepoch.<ref>{{Cite news|date=2007-09-27|title=Qualcomm gives patent license for CDMA2000 units to Chinese firm|language=en|work=Reuters|url=https://www.reuters.com/article/qualcomm-patent-idUKWNAS497420070927|access-date=2021-12-05|archive-date=December 5, 2021|archive-url=https://web.archive.org/web/20211205160023/https://www.reuters.com/article/qualcomm-patent-idUKWNAS497420070927|url-status=live}}</ref>

==References== {{Reflist}}

==External links== * [https://web.archive.org/web/20120829055636/http://www.tiaonline.org/standards/committees/committee.cfm?comm=tr-45 TIA TR-45 Engineering Committee for CDMA Standards] * [http://www.3gpp2.org/ 3GPP2] {{Webarchive|url=https://web.archive.org/web/20040123013738/http://3gpp2.org/ |date=January 23, 2004 }} Standards and specifications * [http://www.radio-electronics.com/info/cellulartelecomms/3gpp2/cdma2000-1xrtt-basics-tutorial.php CDMA2000] Overviews of the CDMA2000 standards - 1X to UMB * [http://cdma2000.info cdma2000.info] Online interactive cdma2000 SDU decoder - covers all releases up to C.S0005-F 2.0

{{DEFAULTSORT:Cdma2000}} Category:3rd Generation Partnership Project 2 standards Category:Code division multiple access