High-Speed Uplink Packet Access
This chapter presents High-Speed Uplink Packet Access (HSUPA) for Wideband Code Division Multiple Access (WCDMA), the key new feature included in Release 6 specifications. The HSUPA solution has been designed to deliver similar benefits for the uplink as did the High-Speed Downlink Packet Access (HSDPA) in Release 5, covered in Chapter 12, for the downlink. The technologies applied with HSUPA are to improve uplink packet data performance by means of fast physical layer (L1) retransmission and transmission combining, as well as fast Node B (Base Transceiver Station (BTS)) controlled scheduling. The chapter is organized as follows: first, HSUPA key aspects are presented and then a comparison with Release 99 uplink packet access possibilities is made. Next, the impact of HSUPA on the terminal (or User Equipment (UE) in 3rd Generation Partnership Project (3GPP) terms) capability classes is summarized and HSUPA performance analysis is presented, including a comparison with Release 99 uplink packet data capabilities.
13.2 Release 99 WCDMA Downlink Packet Data Capabilities
In Release 99, various methods exist for packet data transmission in WCDMA uplink. As described in Chapters 6 and 10, the three different channels in Release 99 and Release 4 WCDMA specifications that can be used for uplink packet data are:
- Dedicated Channel (DCH);
- Common Packet Channel (CPCH);
- Random Access Channel ...