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CDMA2000 is a 3G mobile telecommunications standard, one of the approved radio interfaces for the ITU's IMT-2000 standard, and a successor to 2G CDMA (IS-95, branded cdmaOne). The underlying signaling standard is known as IS-2000. CDMA2000 is an incompatible competitor of the other major 3G standard W-CDMA.
CDMA2000 is a registered trademark of the Telecommunications Industry Association (TIA-USA) in the United States, not a generic term like CDMA. TIA has branded their 2G CDMA standard (aka IS-95) as cdmaOne.
There are many different types of CDMA2000. In order of increasing complexity:
CDMA2000 1x, also known as 3G1X or sometimes 1xRTT, is the core 3G CDMA2000 technology. The designation 1x is used to identify the version of CDMA2000 radio technology that operates in one pair of 1.25 MHz radio channels.
CDMA2000 1xRTT (Radio Transmission Technology) is the basic layer of CDMA2000, which supports up to 144 kbit/s packet data speeds. While 1xRTT officially qualifies as 3G technology, 1xRTT is considered by most to be a 2.5G (or sometimes 2.75G) technology as it is several times slower than other 3G technologies. It also doubles voice capacity over previous CDMA networks.
CDMA2000 1xEV (Evolution) is CDMA2000 1x with High Data Rate (HDR) capability added. 1xEV is commonly separated into two phases:
Phase 1 of CDMA2000 1xEV, CDMA2000 1xEV-DO (Evolution-Data Optimized) supports downlink (Forward Link) data rates up to 3.1 Mbit/s and Up Link (Reverse Link) rates up to 1.8 Mbps in a radio channel dedicated to carrying high speed packet data.
Phase 2 of CDMA2000 1xEV, CDMA2000 1xEV-DV (Evolution-Data and Voice), supports downlink (Forward Link) data rates up to 3.1 Mbit/s and Up Link (Reverse Link) rates of up to 1.8 Mbits/s. 1xEV-DV can also support concurrent operation of legacy 1x voice users, 1xRTT data users, and high speed 1xEV-DV data users within the same radio channel.
1xEV-DO is commercially deployed around the world. The European market is slightly ahead of the American market - there is a CDMA2000 1xEV-DO network run by the Czech mobile operator Eurotel since Summer 2004. It offers speeds up to around 1Mbps. The service is sold for about 30 Euro/month with unlimited data. You have to purchase a Gtran GPC-6420 modem for about 300 Euro to start using the service.
As of July 2004, there are no commercial deployments of 1xEV-DV. American carrier Sprint PCS had announced plans to deploy a 1xEV-DV network on top of their existing CDMA network. However, due to delays in the availability of 1xEV-DV equipment and competitive pressures from other American networks deploying 3G networks, Sprint announced, in June 2004, its intention to broadly deploy 1xEV-DO.
Qualcomm has recently put the development of EV-DV on an indefinite halt, due to lack of carrier interest, mostly because both Sprint and Verizon are using EV-DO.
CDMA2000 3x utilizes a pair of 3.75 MHz radio channels (i.e., 3 X 1.25 MHz) to achieve higher data rates. The 3X version of CDMA2000 is sometimes referred to as Multi-Carrier or MC. The 3x version of CDMA2000 has not been deployed and is not under development at present.
- Radio-Electronics.ComArticle on CDMA20001xEV-DO
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