A proposed hardware upgrade for the existing Code Division Multiple Access (CDMA) cellular telephone system. CDMA2000 was developed by the Telecommunications Industry Association (TIA) and is part of the International Mobile Telecommunications-2000 (IMT-2000) initiative of the International Telecommunication Union (ITU). CDMA2000 boosts the bandwidth of existing CDMA cellular systems to 2 Mbps. Another common name for this system is 3G 3X.
The existing interim standard for CDMA is IS-95a, commonly called CDMAone (the brand name used by the vendor consortium called the CDMA Development Group). This standard has approximately 30 million users in the United States and Asia and competes with Time Division Multiple Access (TDMA) systems such as the Global System for Mobile Communications (GSM), with 150 million users worldwide; Digital Advanced Mobile Phone Service (D-AMPS), with 15 million users in the United States; and Personal Digital Cellular (PDC), with 45 million users in Japan. Since the CDMA upgrade includes only a small portion of the overall wireless communication market, the IMT-2000 initiative also includes proposed upgrades to TDMA systems. A competing upgrade for TDMA systems is General Packet Radio Service (GPRS), which is closer to implementation than CDMA2000 and might therefore win more support than CDMA2000.
The term “3G 1X” is used to describe a CDMA2000 system that uses the existing IS-94a base stations. This configuration limits transmission speeds to 144 Kbps. The CDMA Development Group promotes its implementation of the ANSI IS-95c standard as an alternative upgrade path from CDMAone. This implementation is commonly known as high data rate (HDR) and involves a hardware upgrade that gives users up to 10 aggregated 14.4-Kbps channels, but few vendors support this proposal because of the IMT-2000 initiative.