HSDPA, HSUPA and HSPA

High-Speed Downlink Packet Access is an enhanced 3G mobile telephone communications protocol. Also dubbed 3.5G, 3G+, and Turbo 3G, HSDPA allows networks based on the Universal Mobile Telecommunications System (UMTS) to offer enhanced down-link data rates up to 99.3 Mb/s. The more recent HSPA+ (High-Speed Packet Access) can achieve speeds of 337.5 Mb/s. The high-speed down-link data channel from the base station is shared between its mobile users, and constantly re-scheduled according to the quality of the radio link to each phone. The data speeds made available the delivery of good quality live video to mobile phones.