CDMA2000, also known as IMT-CDMA Multi-Carrier or 1xRTT, is a code-division multiple access (CDMA) version of the IMT-2000 standard developed by the International Telecommunication Union (ITU). The CDMA2000 standard is third-generation (3-G) mobile wireless technology. The world's first 3G commercial system was launched by SK Telecom (South Korea) in October 2000, using CDMA2000 1X.
CDMA2000 can support mobile data communications at speeds ranging from 144 Kbps to 2 Mbps. Versions have been developed by Ericsson and Qualcomm. As of March 2006, the CDMA Development Group reports more than 250,300,000 subscribers worldwide.