Wideband Code Division Multiple Access, or W-CDMA, is a wireless communication technology derived from Code Division Multiple Access (CDMA) cellular phone technology that is proposed for 3G (third-generation) wireless communication systems. Wideband Code Division Multiple Access (W-CDMA) uses wider frequency bands than CDMA, so it can achieve higher throughput for data transmission. The Universal Mobile Telecommunications System (UMTS) standard proposed by the European Telecommunications Standards Institute (ETSI) and incorporated into the International Mobile Telecommunications-2000 (IMT-2000) initiative of the International Telecommunication Union (ITU) is partly based on W-CDMA.
W-CDMA is not fully compatible with air and network interfaces of the proposed CDMA2000 standard, which is another part of the IMT-2000 initiative, and it is not compatible with the air interface of the existing Global System for Mobile Communications (GSM) cellular phone network. The CDMA2000 standard uses synchronous base station transmissions with 20-millisecond frames, while W-CDMA uses asynchronous base station transmissions with 10-millisecond frames.