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.
RAD’s cell-site and aggregation site gateways backhaul 3G UMTS and 3.5G HSPA services over ATM, xDSL and packet switched transport, using standard pseudowire encapsulation with comprehensive QoS features. In addition to supporting quality delivery of UMTS data, they ensure accurate synchronization for R.99 voice traffic, using advanced clock recovery and distribution schemes to meet G.823/G.824 and G.8261 requirements, and enable frequency accuracy of +/-16 ppb (parts per billion).
