The High-Speed Uplink Packet Access (HSUPA) protocol works with the 3G mobile telephone network, providing a maximum uplink speed of 5.76 megabits per second (Mbps). HSUPA is a part of the High-Speed Packet Access (HSPA) software family of protocols, maintained and defined by the 3rd Generation Partnership Project (3GPP). The 3GPP group, made up of numerous telecommunications associations, is involved in creating specifications for the 3G mobile phone system. Among its services, 3G allows simultaneous transfer of both voice data and non-voice data. To make use of HSPA protocols, you must have a mobile device that is HSPA-enabled.
HSUPA improves the performance of the enhanced dedicated channel (E-DCH) by increasing throughput and reducing delays. In other words, it increases the speed at which your mobile device can communicate with the network. The HSUPA is designed to quickly match the signal and protocol parameters required for wireless communications, also known as link adaptation. The new protocol also improves performance by reducing latency.
The latest version of HSUPA, with its uplink speed of 5.76 Mbps, can provide many more potential uses of Internet applications for 3G mobile devices. With better speeds, users might be more inclined to upload videos, for example. In terms of how the HSUPA protocol performs its work, it is similar to the High-Speed Downlink Packet Access (HSDPA) protocol. HSDPA essentially gives mobile devices the ability to receive large files, including e-mail attachments and web pages.
HSUPA makes use of a few new features, as well. Fast Hybrid Automatic Repeat reQuest (ARQ) is one of them. This allows the base station in the mobile network to make an immediate request to retransmit data, should it contain errors. By making retransmission requests more efficient, the overall data transmission can occur more quickly.
Multi-Code Transmission is a new feature as well. It allows for simultaneous use of as many as four codes by one user, rather than using one code per user. With multiple codes available at the same time, the user will see an increase in the uplink data rate.
Short Transmission Time Interval, which makes use of an uplink interval of either 2 milliseconds (ms) or 10 ms, is yet another new feature made available by HSUPA. The previous uplink interval ranged from 10 ms to 40 ms. With a shorter interval, overall transmission times are shorter.
Nokia actually created the name HSUPA but the 3GPP uses the term Enhanced Uplink (EUL) to refer to HSUPA.