HSPA - High Speed Packet Access is a mobile broadband technology built on third generation (3G) UMTS/WCDMA and is strongly positioned as the leading mobile data technology for the foreseeable future. It is an amalgamation of two mobile telephony protocols, High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA), that extends and improves the performance of existing WCDMA protocols.

Where HSDPA optimizes downlink performance, HSUPA uses the Enhanced Dedicated Channel (E-DCH) for a set of improvements that optimizes uplink performance. Networks and devices supporting HSUPA became available in 2007 and the combined improvements in the uplink and downlink are called HSPA. These improvements include higher throughputs, reduced latency and increased spectral efficiency. HSUPA (HSPA) is standardized in Release 6 and results in an approximated 85 percent increase in overall cell throughput on the uplink and more than 50 percent gain in user throughput. HSUPA also reduces packet delays, a significant benefit resulting in significantly improved application performance on HSPA networks.

HSPA is the most widely deployed mobile broadband technology in the world today and will build upon more than 5 billion connections with the GSM family of technologies. Globally, there are more than 400 commercial networks with HSPA in more than 150 countries. Propelling the strong growth is a strong selection of devices supporting HSPA. Already, there are more than 3000 commercial HSPA devices available worldwide from more than 260 suppliers.

Initial HSPA networks offered 3.6 Mbps peak downlink rates with the bulk of the remainder offering 7.2 Mbps; however, continued progress by vendors and leading innovative operators, allows for HSPA networks capable of peak bit-rates of 14.4 Mbps in the downlink and 5.76 Mbit/s in the uplink. In current deployments, HSPA users regularly experience throughput rates well in excess of 1 Mbps under favorable conditions, on both downlinks and uplinks, with 4 Mbps downlink speed commonly measured; planned enhancements will double peak user-achievable throughput rates.

 Beyond throughput enhancements, HSPA also significantly reduces latency. In optimized networks, latency will fall below 50 milliseconds (ms), relative to current HSDPA networks at 70 ms.  And with a later HSPA introduction of 2 ms Transmission Time Interval (TTI), latency will be as low as 30 ms.

The use of higher order modulation schemes (from 16 QAM up to 64 QAM), along with MIMO technology, which takes HSPA into HSPA+ or evolved HSPA was developed in 3GPP Release 7. The first HSPA+ networks using 64 QAM modulation and offering 21 Mbps are also in operation. 

HSPA gives carriers an efficient mobile broadband technology that can evolve to HSPA+ to meet the advanced wireless needs of customers. To leverage operator investments in HSPA and enhance the quality of service across networks, 3GPP finalized Release 7 and Release 8, which specify a series of enhancements to create HSPA+. Also, 3GPP examined further specifications in Release 9. HSPA+ employs many of the techniques utilized for LTE.

HSPA+