High Speed Packet Access

Data services and multimedia are expected to have significant growth over the next few years and will likely become the dominant source of 3G traffic. High Speed Downlink Packet Access (HSDPA) provides large enhancements over Wideband Code Division Multiple Access (WCDMA) for the downlink. HSDPA was standardized as part of Third Generation Partnership Project (3GPP) Release 5 and Release 6. The HSDPA peak date rate available in the terminals is initially 1.8 Mbps, and it is increasing to 3.6 and 7.2 Mbps with potential beyond 10 Mbps. HSDPA has been designed to increase downlink packet data throughput by means of fast physical layer retransmission and transmission combining as well fast link adaptation controlled by the Node B – i.e. a base transmission station (BTS). High Speed Uplink Packet Access (HSUPA) was part of 3GPP Release 6 with the first specification version in December 2004. The HSUPA peak data rate in the initial phase is expected to be 1– 2 Mbps with the second phase pushing the data rate to 3– 4Mbps. HSDPA and HSUPA together are called High Speed Packet Access (HSPA). The section covers HSPA principles for WCDMA – the key new feature included in Release 5 and enhanced further in Release 6 specification.