High Speed Packet Access

HSPA: High Speed Packet Access

HSPA - High Speed Packet Access is the most widely deployed mobile broadband technology in the world today and will build upon the 3.8 billion connections with the GSM family of technologies. HSPA is the terminology used when both HSDPA (3GPP Release 5) and HSUPA (3GPP Release 6) technologies are deployed on a network. HSPA Evolved (HSPA+ in 3GPP Release 7 and beyond) is also part of the HSPA technology and extends an operator’s investment in the network before the next step to 3GPP Long Term Evolution (LTE, or 3GPP Release 8 and beyond). HSPA builds on third generation (3G) UMTS/WCDMA and is strongly positioned as the leading mobile data technology for the foreseeable future.

According to independent analyst firm Informa Telecoms & Media, more than 94 percent of UMTS/WCDMA operators launched HSPA by the end of 2008. At the time, Informa reported there were 82.8 million HSPA customers worldwide and that number is expected to top 800 million by 2013.

Globally, there are more than 265 commercial networks with HSDPA of which 77 have been upgraded to HSPA; in Latin America, there are 47 HSDPA networks in 23 countries (May 2009). All UMTS and HSDPA networks are expected to be upgraded to HSPA.

Many HSPA networks, approximately 70% as of 1Q 2009, offer 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. The first networks using 64 QAM modulation and offering 21 Mbps are also in operation. The use of higher order modulation schemes (from 16 QAM up to 64 QAM), along with MIMO technology, takes HSPA into ‘HSPA+’ or evolved HSPA such as developed in 3GPP Release 7.

Propelling the strong growth is a strong selection of devices supporting HSPA. The GSMA reported that more than 1,343 HSPA devices were on the market from 135 suppliers as of 1Q 2009.

Whereas 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.

Typical HSPA downlink user achievable rates are 1 to 4 Mbps and typical user achievable HSPA uplink speeds are 500 kbps to 2 Mbps as of 1Q 2009. Theoretical peak speeds are significantly higher at 14 Mbps on the downlink and 5.8 Mbps on the uplink in a 5 MHz channel.

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.

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, standards body 3GPP finalized Release 7 and Release 8, which specify a series of enhancements to create HSPA+. Also, 3GPP is examining further specifications in Release 9. HSPA+ employs many of the techniques utilized for LTE.