CDMA2000
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CDMA2000 is a 3rd generation mobile communications standard. It is a member of the IMT-2000 "family" of standards. CDMA2000 is based on the 2nd generation cdmaOne/IS-95 standard.
CDMA2000 1X
Within the IMT-2000 family, CDMA2000 is officially known as IMT-CDMA Multi-Carrier. Eventually, CDMA2000 will offer the possibilty to use 1 up to 3 carriers of 1,25 MHz width each. A carrier of 1,25 MHz width is chosen to make a smooth evolution from cdmaOne possible. CDMAOne works with a channel width of 1,25 MHz.
CDMA2000 1XEV-DO and CDMA2000 1XEV-DV
The evolution from cdmaOne to CDMA2000 takes place in several phases. The first phase CDMA2000 1X, also referrred to as 1X RTT, introduces packet data with a peak bitrate of 144 kbps and 60-90 kbps on average.
CDMA2000 1X is fully compatible with cdmaOne. An improved version (Release 1) will double the bit rate to a peak rate of 307 kbps.
The next phase is known as CDMA2000 1X-EV (Evolved). The first step in this phase is 1X-EV-DO (Data Only). 1X-EV-DO will support data rates up to 2.4 Mbps on the downlink (the uplink will remain 153 kbps) on a dedicated data carrier. Finally, 1X-EV-DV (Data and Voice) will support even higer peak rates of 3.09 Mbps, simultaneous voice and high speed data, as well as improved Quality of Service mechanisms to make e.g high quality videoconferencing possible.
CDMA2000 is being developed by 3GPP2.