HSDPA (High Speed Downlink Packet Access)

HSDPA (High Speed Downlink Packet Access) is a kind of mobile communication protocol, also called 3.5 G (3 & frac12; G). The agreement in WCDMA downlink link providing packet data service, in a 5MHz carrier on transmission rate can reach 8-10 Mbit/s (such as using MIMO technology, May 20 Mbit/s). In a concrete realization is introduced in the adaptive modulation and coding (amcs), multi-input multi-output (MIMO), mixed automatic retransmission request (HARQ), rapid scheduling, rapid village selection technology.

In the three standards of 3G category, WCDMA commercial the carrier support on the number lead, but in its supported by the network data rate has long stay in theory of 384kbps level, and the network construction has been slow development state.

In contrast, in Korea, Japan and other countries to realize commercial CDMA2000 1X ev-do network system, has been realized 2.4 Mbps peak rate, its broadband access service can provide clients with 300kBps - 500kBps average download speed, enough and cable broadband rate of comparable.

In comparison, as has been commercialized 3G network system, facing the existing 3G business, WCDMA has slightly inadequate, the speed of data transmission in a huge gap, and science-induced business capability of disadvantaged, nature makes WCDMA faction unwilling to lag behind, must find a kind of surpassing CDMA2000 1X ev-do powerful weapons.

HSDPA technology is improve its high-speed WCDMA network descending speed of data transmission technology, is the most important in 3GPP R5 agreement in order to satisfy downlink data service asymmetrical demand brought out, it can not changing the has construction WCDMA system based on the structure of the network, greatly improving the user downlink data service rate (theoretical maximums can reach 14.4 Mbps), this technology is WCDMA network construction in improving downstream capacity and data service rate is a kind of important technologies.

For high-speed mobile packet data service support ability is 3G system is one of the most important features.

WCDMA R99 version can provide 384kbps data rates, the rate for most existing business in the grouping of basic enough. However, for a lot of traffic and delay to demand higher data services such as video, streaming media and download etc, require the system to provide higher transfer rate and shorter delay.

In the next few years, data service will obtain increased greatly, and become the third generation (3G) mobile communication. The main application and the major source of income. At present Japan and South Korea 3G operators have in the experience of 3G service was a great success. Japan DoCoMo company in 2001 - FOMA services launched WCDMA created to its gross income already accounts for 20% of the until May 2004 already has 400 million subscribers. Korean telecom company (SKT) in 2003, in the 3rd quarter deployed 1xEV - after, this company DO network data service revenue occupy per user average income (ARPU) value ratio rose 34 percent.

In order to adapt multimedia services for high-speed data transmission, the increasing needs of the third generation mobile communication cooperation project team (3GPP) has released a new high-speed data transmission technology, called high-speed downlink grouping access technology (HSDPA). This technique is WCDMA R 99 (i.e., we often say WCDMA) strengthen version, strengthens the downlink link transmission function.

Japan's NTT DoCoMo is the earliest test HSDPA technology operators in 2004, one of 3GSM global conference, HSDPA also changed all major European operator's agenda. In the United States, GSM operators of course also are seeking more weapons so that in more and more aggressive market to ensure the leading status. 1 December 2004, Cingular formal and lucent technologies signed a four-year 3GW - CDMA equipment, software and service supply agreement, included HSDPA technology deployment. Agreement will make Cingular company since 2005 to provide consumers with a wide range of multimedia services.

PA consultancy company and Yankee group that needs may HSDPA recently first from the enterprise market. PA consulting company believe in the enterprises, HSDPA market W - CDMA case plays key roles. Yankee group will HSDPA technology as a can make operators oriented enterprise market rolls out profitable service important differentiation factor, and to faster 3G service evolution plays very prominent role.

More attention by group of network efficiency of new technology, the influence of think deployment HSDPA technology operators will get quite competitive advantage.

In order to develop the 3GPP data services, and from the two aspects of air interface improved, introduced HSDPA technology. HSDPA not only support high-speed asymmetric data services, and greatly increase the network capacity of in the meantime also can make operator input cost minimization. It for UMTS higher data transfer rate and higher capacity provides a smooth evolution ways, as well as in GSM network introducing EDGE as well. HSDPA development is divided into three stages, namely basic HSDPA stage, enhance HSDPA stage and HSDPA further evolutionary stages, including HSDPA further evolutionary stages are not yet final determination, still in 3GPP inside for research.