Quezi

The Sony Ericsson Xperia X1 supports HSPA (photo by tomsun - CC-BY)

The terms HSPA, HS*PA, HSDPA and HSUPA all relate to the high speed data access provided by high-specification cellphones and the cellular networks to which those phones are attached.

These are “high speed” technologies over and above that provided by “third generation” (3G) cellphone technology.

HSDPA stands for “high speed downlink packet access” and is a way to download data from the internet to the mobile phone at very high speeds. As of late 2008, the fastest HSDPA speed that is widely implemented is 7.2 Mbit/s (megabits per second), although many high-end phones are limited to 3.6 Mbit/s.

All of these figures are theoretical maximums which are unlikely to be achieved in practice. They assume a perfect radio link between the mobile phone and the cellphone tower, and that there are no other phones sharing the tower’s available bandwidth. Nevertheless, HSDPA can provide a very satisfying speed for web browsing – not quite up to the speed available using WiFi but fast enough to have a similar “feel”.

HSUPA is “high speed uplink packet access” and is the corresponding technology for uploading data quickly from the phone to the internet. It is alternatively known as “enhanced uplink” (EUL), and has a theoretical maximum speed of 5.76 Mbit/s.

For most users, uplink speed isn’t nearly so important as downlink speed. However, users who are uploading large photos, videos, songs or other media files will benefit from a fast uplink speed.

The abbreviations HSPA and HS*PA can be read as “high speed packet access” and are loose ways of referring to various mobile phone protocols that improve on the performance of standard 3G (UMTS) protocols. As of 2008/09 the most important HSPA protocols are HSDPA and HSUPA, but HSPA could also be considered to include “Evolved High Speed Packet Access” (HSPA+) which has a theoretical maximum of 42 Mbit/s downlink and 22 Mbit/s uplink.