什么是HSPA？

    WCDMA的R99和R4系统能够提供的最高上下行速率分别为64kbps和384kbps，为了能够与CDMA1XEV-DO抗衡，WCDMA在R5规范中引入了HSDPA，在R6规范中引入了HSUPA，HSDPA和HSUPA合称为HSPA。
    HSDPA（高速下行分组接入）在下行链路上能够实现高达14.4Mbit/s的速率。通过新的自适应调制与编码以及将部分无线接口控制功能从无线网络控制器转移到基站中，实现了更高效的调度以及更快捷的重传，HSDPA的性能得到了优化和提升。
    HSUPA（高速上行分组接入）在上行链路中能够实现高达5.76Mbit/s的速度。基站中更高效的上行链路调度以及更快捷的重传控制成就了HSUPA的优越性能。
    HSDPA (High-Speed Downlink Packet Access) is specified in 3GPP Release 5. With HSDPA, WCDMA has been extended with additional transport and control channels, such as the high-speed downlink shared channel (HS-DSCH), which provides enhanced support for interactive, background and, to some extent, streaming services.
    Enhanced Uplink is specified in 3GPP Release 6 and has been extended with additional transport and control channels, such as the enhanced dedicated channel (E-DCH), and with similar features to HSDPA. Enhanced Uplink will cater for the needs of mobile broadband with increased performance in the uplink: it will provide up to 5.8Mbps in the uplink, reduced delay and 150-200 percent greater system capacity.