HSUPA

HSUPA, or High-Speed Uplink Packet Access, is an extension of the UMTS standard to improve uplink data transmission in mobile networks. It is part of the High Speed Packet Access family (HSPA) alongside HSDPA for downlink, introduced by 3GPP as part of Release 6, with later enhancements. HSUPA enables higher uplink throughput and more efficient use of uplink radio resources than earlier UMTS uplink schemes.

Technical approach: To achieve higher uplink rates, HSUPA introduces the Enhanced Uplink channel (E-DCH), a scheduling mechanism in the Node B that allocates uplink resources on a per-user basis. It uses fast HARQ with incremental redundancy and adaptive modulation and coding. Uplink transmissions may use more advanced coding and modulation depending on conditions, and the system includes improved power control to balance performance and interference. The result is lower latency and higher practical uplink speeds than older UMTS uplink schemes.

Impact and deployment: HSUPA has been deployed worldwide as part of HSPA networks, providing uplink speeds in the Mbps range under favorable conditions; real-world rates depend on bandwidth, load, and device capability. The technology was later supplemented by HSPA+ enhancements that increased uplink and downlink performance. HSUPA is usually discussed with HSDPA as part of the HSPA family that raised data rates on 3G networks.