UMTS (Universal Mobile Telecommunications System) is a 3G mobile technology using W-CDMA (Wideband Code Division Multiple Access) air interface. Developed to support voice and broadband services, such as video telephony and video conferencing, UMTS/W-CDMA offers data rates of up to 2 Mbps, compared to the 64 kbps bandwidth supported by 2G networks. These rates have been later upgraded to potentially 14 Mbps downstream with 3.5G HSDPA (High-Speed Downlink Packet Access) and 6 Mbps upstream with HSUPA (High-Speed Uplink Packet Access).
Original 3GPP (3G Partnership Project) standards for UMTS defined ATM as the transport network. As a result, 3G radio access network (RAN) elements, such as Node Bs and RNCs, feature ATM uplink interfaces. Nevertheless, cellular backhaul today comprises a variety of additional transport technologies, including widely prevalent 2G TDM, xDSL and new Ethernet/IP/MPLS. This requires mobile operators and transport providers to deploy multiservice RAN gateways to enable simultaneous and economical delivery of W-CDMA and other, multi-generation traffic, across any access.