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Concept
High Speed Packet Access
Résumé
High Speed Packet Access (HSPA) is an amalgamation of two mobile protocols—High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA)—that extends and improves the performance of existing 3G mobile telecommunication networks using the WCDMA protocols. 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.
The first HSPA specifications supported increased peak data rates of up to 14 Mbit/s in the downlink and 5.76 Mbit/s in the uplink. They also reduced latency and provided up to five times more system capacity in the downlink and up to twice as much system capacity in the uplink compared with original WCDMA protocol.
High Speed Downlink Packet Access (HSDPA) is an enhanced 3G (third-generation) mobile communications protocol in the High-Speed Packet Access (HSPA) family. HSDPA is also known as 3.5G and 3G+. It allows networks based on the Universal Mobile Telecommunications System (UMTS) to have higher data speeds and capacity. HSDPA also decreases latency, and therefore the round-trip time for applications.
HSDPA was introduced in 3GPP Release 5. It was accompanied by an improvement to the uplink that provided a new bearer of 384 kbit/s (the previous maximum bearer was 128 kbit/s). 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. Under 3GPP Release 11, even higher speeds of up to 337.5 Mbit/s were possible.
The first phase of HSDPA was specified in 3GPP Release 5. 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.
Source officielle
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