The document discusses HSPA systems and provides an overview of High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA). It notes that HSPA was introduced to improve the packet data capabilities of WCDMA in response to growing interest in rich calls, mobile TV, and streaming services. HSDPA introduced faster scheduling, link adaptation, and hybrid automatic repeat request to improve downlink performance, while HSUPA later improved uplink performance using similar techniques. The document provides technical details on the channels, link adaptation, scheduling, mobility, and retransmissions used in HSDPA and HSUPA systems.