HSUPA

High Speed Uplink Packet Access (HSUPA) is an upgrade to UMTS/HSDPA that uses the Enhanced Dedicated Channel (E-DCH) to constitute a set of improvements to optimize uplink performance. These improvements include higher throughput, reduced latency, and increased spectral efficiency.

HSUPA is standardized in Release 6. HSUPA will result in an approximately 85 percent increase in overall cell throughput on the uplink and an approximately 50 percent gain in user throughput. HSUPA also reduces packet delays.

HSUPA achieves its performance gains through the following approaches:

• An enhanced dedicated physical channel
• A short Transmission Time Interval (TTI), as low as 2 milliseconds, which allows faster responses to changing radio conditions and error conditions
• Fast Node-B-based scheduling, which allows the base station to efficiently allocate radio resources
• Fast Hybrid Automatic Repeat Request (ARQ), which improves the efficiency of error processing The combination of TTI, fast scheduling, and Fast Hybrid ARQ also serves to reduce latency, which can benefit many applications as much as improved throughput. HSUPA can operate with or without HSDPA in the downlink, though it is likely that most networks will use the two approaches together. The improved uplink mechanisms also translate to better coverage, and for rural deployments, larger cell sizes.

Many operators have or are now deploying UMTS worldwide. Nearly all UMTS operators are expected to upgrade to HSDPA, a downlink enhancement to UMTS. HSUPA, the corresponding enhancement for the uplink, was first deployed commercially in February of 2007, and is in the process of being adopted by operators worldwide.

Additional information

Global 3G Status Update

HSDPA - Mobile Broadband Today: Examining the economics of different broadband technologies (GSMA Presentation on HSDPA, August 2007 - PDF, 555 KB)

EDGE, HSPA, LTE: The Mobile Broadband Advantage (3G Americas white paper, Sept 2007)

UMTS Evolution from 3GPP Release 7 to Release 8: HSPA and SAE/LTE (3G Americas white paper, July 2007)

First Launch of HSUPA (February 2007)

HSUPA Questions and Answers