cdma2000 is a third-generation (3G) wireless technology that is evolved from existing CDMA 2G technology. Its main features are faster data rates, always-on data service, and improved voice network capacity (more people can use each tower at the same time).
cdma2000 will be deployed in at least three phases.
The first, 1xRTT, supports up to 144 Kbps packet data speeds. It also doubles voice capacity over previous CDMA networks (IS-95).
The second release of 1x, 1xEV-DO, will support data rates up to 2.4 Mbps. It can only be deployed separately from voice networks - in its own spectrum - although devices can be made to access both networks.
The third, 1xEV-DV, supports circuit and packet data rates up to 3-5 Mbps. It fully integrates with 1xRTT voice networks.
A possible fourth phase is cdma2000 3x, although it uses three times as much spectrum.