TIA/EIA IS-95 (Telecommunications Industry Association / Electronic Industries Association Interim Standard - 95) was first published in July 1993. The IS-95A revision was published in May 1995 and is the basis for many of the commercial 2G CDMA systems around the world. IS-95A describes the structure of the wideband 1.25 MHz CDMA channels, power control, call processing, hand-offs, and registration techniques for system operation. In addition to voice services, many IS-95A operators provide circuit-switched data connections at 14.4 kbps. IS-95A was first deployed in September 1996 by Hutchison (HK).

The IS-95B revision, also termed TIA/EIA-95, combines IS-95A, ANSI-J-STD-008 and TSB-74 into a single document. The ANSI-J-STD-008 specification, published in 1995, defines a compatibility standard for 1.8 to 2.0 GHz CDMA PCS systems. TSB-74 describes interaction between IS-95A and CDMA PCS systems that conform to ANSI-J-STD-008. Many operators that have commercialized IS-95B systems offer 64 kbps packet-switched data, in addition to voice services. Due to the data speeds IS-95B is capable of reaching, it is categorized as a 2.5G technology. cdmaOne IS-95B was first deployed in September 1999 in Korea and has since been adopted by operators in Japan and Peru.

3G is the term used to describe next generation mobile services which provide better quality voice and high-speed Internet and multimedia services. While there are many interpretations of what 3G represents, the only definition accepted universally is the one published by the International Telecommunication Union (ITU). ITU, working with industry bodies from around the world, defines and approves technical requirements and standards as well as the use of spectrum for 3G systems under the IMT-2000 (International Telecommunication Union-2000) program.
The ITU requires that IMT-2000 (3G) networks, among other capabilities, deliver improved system capacity and spectrum efficiency over the 2G systems and support data services at minimum transmission rates of 144 kbps in mobile (outdoor) and 2 Mbps in fixed (indoor) environments.
Based on these requirements, in 1999 ITU approved five radio interfaces for IMT-2000 standards as a part of the ITU-R M.1457 Recommendation. CDMA2000 is one of the five standards. It is also known by its ITU name IMT-CDMA Multi Carrier.



CDMA2000 represents a family of technologies that includes CDMA2000 1X and CDMA2000 1xEV.
CDMA2000 1X can double the voice capacity of cdmaOne networks and delivers peak packet data speeds of 307 kbps in mobile environments.

CDMA2000 1xEV includes:
 -CDMA2000 1xEV-DO
  CDMA2000 1xEV-DO delivers peak data speeds of 2.4Mbps and supports applications such as
  MP3 transfers and video conferencing.
 -CDMA2000 1xEV-DV
  CDMA2000 1xEV-DV provides integrated voice and simultaneous high- speed packet data
  multimedia services at speeds of up to 3.09 Mbps.
 -1xEV-DO and 1xEV-DV are both backward compatible with CDMA2000 1X and cdmaOne.

The world's first 3G (CDMA2000 1X) commercial system was launched by SK Telecom (Korea) in October 2000. Since then, CDMA2000 1X has been deployed in Asia, North and South America and Europe, and the subscriber base is growing at 700,000 subscribers per day. CDMA2000 1xEV-DO was launched in 2002 by SK Telecom and KT Freetel. The commercial success of CDMA2000 has made the IMT-2000 vision a reality.