CDMA2000 1X (IS-2000) is an IMT-2000 (3G) technology, designed to deliver high-quality voice and high-speed data. It is an efficient wireless technology for circuit-switched voice communications and it supports packet data speeds of up to 153.6 kbps in a single 1.25 MHz radio channel.

CDMA2000 1X was the first 3G (IMT-2000) technology deployed, in October 2000.

Key features of CDMA2000 1X:

• Voice Capacity: Today, CDMA2000 1X supports 33-40 simultaneous voice calls per sector in a single 1.25 MHz FDD channel. Using a new codec (EVRC-B), additional Walsh codes and handset interference cancellation, it can handle up to 55 simultaneous voice calls. With further receiver enhancements and minor changes to the radio configuration, 1X Advanced (1X Rev. E) will quadruple the voice capacity of CDMA2000 1X systems.
• High-Speed Data: Supports bi-directional (up and downlink) peak data rates up to 153.6 kbps, delivering an average user data throughput of 80-100 kbps in commercial networks using a 1.25 MHz FDD channel.
• Spectral Efficiency: Up to 0.180 bit/sec/MHz over a 5 MHz FDD channel.
• Average Latency: 250 msec node-to-node ping, RTT.
• Applications: Supports circuit-switched voice, short messaging service (SMS), ringtone downloads, multimedia messaging service (MMS), games, GPS-based location services, music and video downloads.
• Backwards Compatibility: CDMA2000 1X is backwards compatible with 2G cdmaOne (IS-95A/B) systems and handsets.