High Speed Downlink Packet Access (HSDPA)
A UMTS packet-based broadband data service feature of the WCDMA standard. HSDPA provides an improved downlink for the UMTS data service. It improves speed and system capacity by making better use of the bandwidth. Data transmission speeds are up to 8-10 Mbps over a 5 MHz bandwidth or more than 20 Mbps for systems that use multiple transmitters and receivers (Multiple Input Multiple Output or MIMO systems (802.11n)). The high speeds of HSDPA are achieved through techniques including 16 Quadrature Amplitude Modulation, variable error coding, and incremental redundancy. HSDPA use requires technology upgrades to sending and receiving devices in UMTS networks. This broadband service is provided by Cingular in limited locations in 2006.