High Speed Packet Access

A further-improved 3GPP standard called Evolved High Speed Packet Access (also known as HSPA+) was released late in 2008, with subsequent worldwide adoption beginning in 2010.

The newer standard allows bit rates to reach as high as 337 Mbit/s in the downlink and 34 Mbit/s in the uplink; however, these speeds are rarely achieved in practice.

It allows networks based on the Universal Mobile Telecommunications System (UMTS) to have higher data speeds and capacity.

Evolved High Speed Packet Access (HSPA+), introduced in 3GPP Release 7, further increased data rates by adding 64QAM modulation, MIMO, and Dual-Carrier HSDPA operation.

This phase introduced new basic functions and was aimed to achieve peak data rates of 14.0 Mbit/s with significantly reduced latency.

The improvement in speed and latency reduced the cost per bit and enhanced support for high-performance packet data applications.

Dual-Cell and MIMO 2x2 each multiply the maximum data rate by 2, because multiple independent transport blocks are transmitted over different carriers or spatial streams, respectively.

In 2007, an increasing number of telcos worldwide began selling HSDPA USB modems to provide mobile broadband connections.

Together with additional improvements, this allows for new features such as Voice over Internet Protocol (VoIP), uploading pictures, and sending large e-mail messages.

It also features several improvements similar to those of HSDPA, including multi-code transmission, shorter transmission time interval enabling faster link adaptation, fast scheduling, and fast hybrid automatic repeat request (HARQ) with incremental redundancy, making retransmissions more effective.

The non-scheduled mode can, for example, be used for VoIP services for which even the reduced TTI and the Node B based scheduler are unable to provide the necessary short delay time and constant bandwidth.

The maximum data rate of each non-scheduled flow is configured at call setup, and typically not frequently changed.