CDMA2000

CDMA2000 is a hybrid 2.5G / 3G technology of mobile telecommunications standards that use CDMA, a multiple access scheme for digital radio, to send voice, data, and signalling data (such as a dialed telephone number) between mobile phones and cell sites. CDMA2000 is considered a 2.5G technology in 1xRTT and a 3G technology in EVDO.

CDMA (code division multiple access) is a mobile digital radio technology where channels are defined with codes (PN sequences). CDMA permits many simultaneous transmitters on the same frequency channel, unlike TDMA (time division multiple access), used in GSM and D-AMPS, and FDMA, used in AMPS ("analog" cellular). Since more phones can be served by fewer cell sites, CDMA-based standards have a significant economic advantage over TDMA- or FDMA-based standards.

CDMA2000 has a relatively long technical history, and remains compatible with the older CDMA telephony methods (such as cdmaOne) first developed by Qualcomm, a commercial company, and holder of several key international patents on the technology.

The CDMA2000 standards CDMA2000 1xRTT, CDMA2000 EV-DO, and CDMA2000 EV-DV are approved radio interfaces for the ITU's IMT-2000 standard and a direct successor to 2G CDMA, IS-95 (cdmaOne). CDMA2000 is standardized by 3GPP2.

CDMA2000 is a registered trademark of the Telecommunications Industry Association (TIA-USA) in the United States, not a generic term like CDMA. (This is similar to how TIA has branded their 2G CDMA standard, IS-95, as cdmaOne.)

CDMA2000 is an incompatible competitor of the other major 3G standard UMTS.It is defined to operate at 450 MHz, 700 MHz, 800 MHz, 900 MHz, 1700 MHz, 1800 MHz, 1900 MHz, and 2100 MHz.

Below are the different types of CDMA2000, in order of increasing complexity:

CDMA2000 1xRTT

CDMA2000 1xRTT, the core CDMA2000 wireless air interface standard, is also known as 1x, 1xRTT, and IS-2000. The designation "1x", meaning "1 times Radio Transmission Technology", indicates the same RF bandwidth as IS-95: a duplex pair of 1.25 MHz radio channels. This contrasts with 3xRTT, which uses channels 3 times as wide (3.75 MHz) 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. Although capable of higher data rates, most deployments are limited to a peak of 144 kbit/s. IMT-2000 also made changes to the data link layer for the greater use of data services, including medium and link access control protocols and 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).

1xRTT officially qualifies as 3G technology, but it is considered by some to be a 2.5G (or sometimes 2.75G) technology. This allows it to be deployed in 2G spectrum in some countries that limit 3G systems to certain bands.

CDMA2000 3x (aka EV-DO rev B)

CDMA2000 3x is (also known as EV-DO Rev B) is a multi-carrier evolution of the Rev A specification. It maintains the capabilities of EVDO Rev A, and provides the following enhancements:
* Higher rates per carrier (up to 4.9 Mbit/s on the downlink per carrier). Typical deployments are expected to include 3 carriers for a peak rate of 14.7 Mbit/s
* Higher rates by bundling multiple channels together enhance the user experience and enables new services such as high definition video streaming.
* Uses statistical multiplexing across channels to further reduce latency, enhancing the experience for latency-sensitive services such as gaming, video telephony, remote console sessions and web browsing.
* Increased talk-time and standby time
* Hybrid frequency re-use which reduces the interference from the adjacent sectors and improves the rates that can be offered, especially to users at the edge of the cell.
* Efficient support for services that have asymmetric download and upload requirements (i.e. different data rates required in each direction) such as file transfers, web browsing, and broadband multimedia content delivery.

CDMA2000 EV-DO

CDMA2000 EV-DV

CDMA2000 EV-DV (Evolution-Data/Voice), supports downlink (forward link) data rates up to 3.1 Mbit/s and uplink (reverse link) data rates of up to 1.8 Mbit/s. EV-DV can also support concurrent operation of legacy 1x voice users, 1x data users, and high speed EV-DV data users within the same radio channel.

In 2004-2005 timeframe, there was much debate on the relative merits of DV and DO. Traditional operators with an existing voice network preferred deploying DV, since it does not require an overlay. Other design engineers, and newer operators without a 1x voice network, preferred EV-DO because it did not have to be backward compatible, and so could explore different pilot structures, reverse link silence periods, improved control channels, etc. And the network cost was lower, since EV-DO uses an IP network and does not require a SS7 network and complex network switches such as a mobile switching center (MSC). Also, equipment was not available for EV-DV in time to meet market demands whereas the EV-DO equipment and mobile application-specific integrated circuits (ASIC) were available and tested by the time the EV-DV standard was completed. As a result, the EV-DV standard was less attractive to operators, and has not been implemented. Verizon Wireless, then Sprint Nextel in 2004 and smaller operators in 2005 announced their plans to deploy EV-DO. So in March 2005, Qualcomm suspended development of EV-DV chipsets, and focused on improving the EV-DO product line.

Countries with CDMA2000 operators

* Bangladesh: Pacific Telecom's [http://www.citycell.com/ Citycell] is the only CDMA2000 1x RTT provider among mobile phone operators. Fixed wireless phone operators ( [http://www.nationalphone.net/ NationalPhone] , [http://www.rankstel.com/ Rankstel] , [http://www.dhakaphone.com/ DhakaPhone] , [http://www.onetelbd.com/ OneTel Communications Ltd.] , [http://www.jalalabad-tel.net/ Jalalabad Telecom Ltd(Bijoy Phone)] ) also provide CDMA2000 1x RTT.
* Belarus: [http://www.belcel.by/en/ BelCel (diallog)] provides CDMA2000 1x and EV-DO in the 450 MHz band (for phones and modems).
* Brazil: Vivo provides a CDMA2000 1xRTT network that is being phased out for an EDGE network and an EVDO network for data access. Embratel also provides a CDMA2000 1xRTT-based network for WLL and an EVDO network for broadband access.
* Canada: Most providers are also using 1x including Aliant, Bell Mobility, Manitoba Telecom Services, NMI Mobility, NorthernTel, SaskTel, Solo Mobile, TBayTel, Télébec Mobilité, TELUS Mobility and Virgin Mobile Canada.
* Czech Republic: Telefonica O2 Czech Republic, formerly Eurotel (the world's first CDMA EV-DO in 450 MHz launched in August 2004), succeeded by UMTS, and Mobilkom a.s. alias [http://www.ufon.cz/ U:fon] (430 MHz launched in May 2007)
* Denmark: Nordisk Mobiltelefoni operates CDMA2000 network in the 450 MHz band. Modems will work in Norway, Sweden, Iceland, Poland and Ireland.
* Ecuador: Telecsa S.A Alegro PCS CDMA 1X - CDMA 1X EVDO network operating in 1900 MHz. Movistar CDMA 1X network operating in 850 MHz.
* Estonia: CDMA2000 1x network operating in 450 MHz spectrum is available since July 2007 by Eesti Energia subsidiary Televõrgu AS by name Kõu, covering all of country territory.
* Gambia: CDMA20001x network, 450, 800 MHz, since 2005 from Gamtel, named Jamano, equipment from Huawei. EV-D0 planned.
* Ghana: CDMA2000 1x network operating in 800 MHz spectrum is available since October 2005 by Kasapa subsidiary Hutchinson Telecom, covering most of the country's 10 regions.
* Iceland: [http://www.ice.net/ Ice.net] "Nordisk Mobiltelefoni AB" will soon launch a CDMA2000 network in the 450 MHz band on Iceland. Modems will work in Norway, Sweden, Denmark, Poland and Ireland.
* India: BSNL, Reliance Communications and Tata Teleservices are major wireless services providers on CDMA2000 1x.
* Indonesia: [http://www.mobile-8.com/ Mobile-8 Telecom] with its brand, FREN is the first Indonesian major wireless operator with CDMA2000 1x RTT and currently expand its EVDO Rev A, who has introduced the first Mobile TV in the market. Later followed by Sampoerna Telecom with its brand, CERIA which operates CDMA 2000 at 450 MHz. The other CDMA2000 providers are running with fixed wireless access license such as Bakrie Telkom with its brand, Esia and Telkom with its brand, TelkomFlexi.
* Ireland: [http://www.ice.net/ Ice.net] "Nordisk Mobiltelefoni AB" will soon launch a CDMA2000 network in the 450 MHz band on Ireland. Modems will work in Norway, Sweden, Denmark, Iceland and Poland.
* Japan: On April 1, 2002, au (by KDDI) launched CDMA 1X brand using CDMA2000 1x technology. On November 28, 2003, au launched EV-DO service in the CDMA 1X WIN brand. au currently providing an EV-DO Rev. A network, the first carrier to do so.
* Kenya: CDMA2000 1x is available in Nairobi through [http://www.telkom.co.ke Telcom Kenya] , [http://www.flashcom.co.ke Flashcom LTD] , and [http://www.popotewireless.co.ke E.M. Communications Ltd.] , which is branded as "popote" in Kenya.
* Latvia: [http://www.triatel.lv Triatel] offers mobile and fixed telephony and data services using CDMA2000 at 450 MHz.
* Malawi: CDMA2000 1x and EV-DO will be available in Malawi in 2008 through [http://www.access.mw Access Communications Ltd] the Second National Operator in the 800 MHz Band.
* Madagascar: Telma (Telecom Malagasy) operates CDMA2000 network in the 450 MHz band. The network called "Telma fixe" is available since 2005 and offers fixed telephony and data services.
* Mexico: Iusacell and Unefon are using the 1x technology.
* Moldova: [http://www.unite.md Unite] offers both mobile and fixed telephony and data services using CDMA2000 in the 450 MHz band since March 2007.
* Mongolia: [http://www.g-mobile.mn G-mobile] and [http://www.Skytel.mn Skytel] are the operators using cdma 2000
* Morocco: Wana has recently launched a CDMA2000 service.
* Nepal: Nepal Telecom is providing the service using CDMA2000 and United Telecom Limited is providing service to customers using IS-95 standard.
* New Zealand: Telecom is the only CDMA2000 network, operating both 1x and EVDO Rev A nationwide, however this is only guaranteed for the next 5 years after recently announcing a switch to GSM [http://www.nzherald.co.nz/category/62/story.cfm?c_id=62&objectid=10444528] .
* Norway: [http://www.ice.no/ Ice.net] former known as Nordisk Mobiltelefon, provides CDMA2000 in the 450 MHz band (for modems). Modems will work in Norway, Sweden, Denmark, Poland, Iceland and Ireland.
* Pakistan: PTCL, World Call, and GoCdma provide CDMA2000 connections..
* People's Republic of China: China Unicom is the major mobile wireless service provider on CDMA2000 1x.
* Poland: Since 2002 [http://www.sferia.pl/ Sferia] provides fixed and mobile telephones in Warsaw using a CDMA2000 radio network in the 870 MHz band. [http://www.ice.net/ Ice.net] "Nordisk Mobiltelefoni AB" will soon launch a CDMA2000 network in the 450 MHz band in Poland. Modems will work in Norway, Sweden, Denmark, Iceland and Ireland. Also the national telephone and internet service provider, [http://www.tp.pl/ Telekomunikacja Polska S.A.] is about to launch a CDMA2000 based internet access service in the 450 MHz band.
* Portugal: Zapp Mobile provides CDMA2000 in the 450 MHz band (for modems).
* Romania: Zapp Mobile provides CDMA2000 in the 450 MHz band (for phones and modems).
* Russia: [http://www.skylink.ru Skylink] is CDMA2000 1x and EV-DO operator in many regions, including Moscow Oblast, Leningrad Oblast and others. [http://www.bwc.ru BWC] is CDMA2000 1x and EV-DO operator in Irkutsk Oblast. [http://www.etk.ru/ ETK] is cdma2000 1x and EV-DO operator in Krasnoyarsk Krai.
* South Africa: Neotel has been awarded a licence to operate in the 800 MHz band by ICASA and launched CDMA2000 services in 2008.
* Sri Lanka: CDMA technology was introduced in 2005 and currently there are 5 CDMA2000 operators. Sri Lanka Telecom (SLT) [http://www.slt.lk/ www.slt.lk] moved to CDMA2000 service supplier and has ZTE EVDO Rev. 0 network and all island covered 1x data service. Suntel [http://www.suntel.lk/ www.suntel.lk] and Lanka Bell [http://www.lankabell.com/ www.lankabell.com] are using 800 MHz range. Both operators have islandwide 1x data service and these days trying to enter EVDO rev0 data market. DBN and Tritel are expecting to enter the Sri Lanka CDMA2000 market in June 2007 on 450 MHz. Among the five operators, Lanka Bell has the largest CDMA2000 market share.
* Suriname: [http://www.telesur.sr Telesur] provides a CDMA2000 1xRTT EV-DO network that is being deployed for high speed mobile data access and WLL.
* Sweden: [http://www.ice.net/ Ice.net] former known as "Nordisk Mobiltelefoni AB" provides CDMA2000 in the 450 MHz band for data modems. The modems can be used on the same network in Norway and Denmark. And later also on Ireland, Iceland and in Poland.
* Taiwan: Asia Pacific Telecom Group (APTG) provides CDMA2000 in the 800 MHz band
* Thailand: Hutch provides CDMA2000-1xRTT service and is in process of deploying EV-DO in 25 provinces. CAT Telecom is currently in the final phase of implementing an EV-DO network in the remaining provinces of Thailand. They plan to join forces and co-market a nationwide EV-DO service under a single brand, which has yet to be decided.
* Ukraine: [http://people.net.ua/ PEOPLEnet] is the provider 800 MHz CDMA2000 1x and EV-DO Rev A since 2007 year. [http://mts.com.ua/ MTS] 450 MHz Rev A (only data, no telephony), [http://www.intertelecom.ua/ Intertelecom (ITC)] 800 MHz CDMA2000 1x and partly EV-DO Rev 0
* United States: Alltel, Cellcom, Cellular South, Cricket Communications (from Leap Wireless), MetroPCS, Sprint PCS, U.S. Cellular and Verizon Wireless use 1x & EVDO.
* Venezuela: Movilnet and movistar are the country's wireless services providers on CDMA2000 1x and CDMA Ev-DO, with nationwide coverage.

External links

* [http://www.3gpp2.org/ 3GPP2] Standards and specifications
* [http://www.cdg.org/ CDMA2000 Development Group (CDG)]
* [http://www.tiaonline.org TIA] Standards documentation
* [http://www.cdg.org/worldwide/cdma_world_subscriber.asp Market statistics from the 'CDMA2000 development group' industry consortium]
* [http://www.cdg.org/worldwide/index.asp?h_area=0&h_technology=999&h_frequency=1 List of countries and operators who have deployed CDMA2000 in the 450 Mhz band]
* [http://www.cdg.org/technology/cdma_technology/cdma_stats.asp CDMA2000 statistics worldwide]
* [http://www.qrctech.com/freq_chart_24x36.pdf Most Widely Used Cellular Channelizations]