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High Speed Packet Access

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It has been suggested that Evolved HSPA be merged into this article or section. (Discuss) Proposed since June 2012.
High Speed Packet Access (HSPA)[1] is an amalgamation of two mobile telephony protocols, High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA), that extends and improves the performance of existing 3rd generation mobile telecommunication networks utilizing the WCDMA protocols. A further improved 3GPP standard, Evolved HSPA (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 168 Mbit/s in the downlink and 22 Mbit/s in the uplink.
Internet protocols
Application layer
Transport layer
Internet layer
Link layer

Contents

Overview

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. It 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 to original WCDMA protocols.
These improvements are achieved in several ways:
  • Shared-channel transmission, which results in efficient use of available code and power resources in WCDMA
  • A shorter Transmission Time Interval (TTI), which reduces round-trip time and improves the tracking of fast channel variations
  • Link adaptation, which maximizes channel usage and enables the base station to operate at close to maximum cell power
  • Fast scheduling, which prioritizes users with the most favorable channel conditions
  • Fast retransmission and soft-combining, which further increase capacity
  • 16-QAM and 64-QAM (Quadrature Amplitude Modulation), which yields higher bit-rates
  • MIMO, which exploits antenna diversity to provide further improvements in bit-rates and system capacity.
By July 2010, HSPA had been commercially deployed by over 200 operators in more than 80 countries.
Many HSPA rollouts could be achieved by a software upgrade to existing 3G networks, giving HSPA a headstart over the then competing solution WiMAX, which requires a dedicated network infrastructure. A rich variety of HSPA enabled devices - more than 1000 available by July 2010 - together with ease of use is leading to rising sales of HSPA-enabled mobiles and is helping to drive the adoption of HSPA.[citation needed]

High Speed Downlink Packet Access (HSDPA)

Main article: HSDPA
The first step required to upgrade WCDMA to HSPA is to improve the downlink by introducing HSDPA. The improved downlink provides up to 14 Mbit/s with significantly reduced latency. The improvement in speed and latency reduces the cost per bit and enhances support for high-performance packet data applications.
HSDPA is based on shared channel transmission and its key features are shared channel and multi-code transmission, higher-order modulation, short Transmission Time Interval (TTI), fast link adaptation and scheduling along with fast Hybrid Automatic Repeat reQuest (HARQ).
The upgrade to HSDPA is often just a software update for most WCDMA networks, and as of May 2008 90 percent of WCDMA networks have been upgraded to HSDPA.[2]
Voice calls are usually prioritized over data transfer.
Singapore's three network providers M1, StarHub and SingTel provide up to 28 Mbit/s throughout the entire island. The Australian provider Telstra provides up to 14.4 Mbit/s nationwide and up to 42Mbit/s in selected areas. The Croatian VIPnet network supports a downlink speed of 7.2 Mbit/s, as does Rogers Wireless in Canada which also supports 21 Mbit/s in the Toronto area.[3] In South Korea, a nationwide 7.2 Mbit/s coverage is now established by SK Telecom and KTF. In Hong Kong, PCCW, CSL and Hutchinson 3 provide 21 Mbit/s coverage and [], BPL, MTS and Tata DoCoMo provide speed of 21.1 Mbit/s nationwide while Reliance ADAE provides speeds up to 28.8 Mbit/s nationwide. Sri-Lankan company Dialog Mobile also provides 7.2 Mbit/s while Mobitel Pvt Ltd provides 3.6 Mbit/s.

High Speed Uplink Packet Access (HSUPA)

Main article: HSUPA
The second major step in the WCDMA upgrade process is to upgrade the uplink, which is introduced in 3GPP Release 6. Upgrading to HSUPA is usually only a software update. Enhanced Uplink adds a new transport channel to WCDMA, called the Enhanced Dedicated Channel (E-DCH). An enhanced uplink creates opportunities for a number of new applications including VoIP, uploading pictures and sending large e-mail messages. The enhanced uplink increases the data rate (up to 5.8 Mbit/s), the capacity, and also reduces latency. The enhanced uplink features several improvements similar to those of HSDPA, including multi-code transmission, short Transmission Time Interval (TTI), fast scheduling and fast Hybrid Automatic Repeat reQuest (HARQ).
In Singapore, Starhub announced a 1.9 Mbit/s HSUPA Service as part of its new MaxMobile plan on 1 August 2007.[4] In Finland, Elisa announced on 30 August 2007 1.4 Mbit/s HSUPA to most large cities with plans to add the service to its whole 3G network within months.[5] (The same announcement contained a promise of covering 25% more of Finland by the end of the year, which actually took two more years to accomplish). 3 Italia and Ericsson announced on 16 July 2008 the successful tests of HSUPA 5.8 Mbit/s in the live network of 3 Italia.[6] In Haiti, NATCOM, the former public company now operated by Viettel from Vietnam, offers up to 7.2 Mbit/s nationwide.

Evolved High Speed Packet Access (HSPA+)

Main article: Evolved HSPA
Evolved HSPA (also known as: HSPA Evolution, HSPA+) is a wireless broadband standard defined in 3GPP release 7 and 8 of the WCDMA specification. it provides extensions to the existing HSPA definitions and is therefore backwards compatible all the way to the original Release 99 WCDMA network releases. Evolved HSPA provides data rates up to 84 Mbit/s in the downlink and 10.8 Mbit/s in the uplink (per 5 MHz carrier) with multiple input, multiple output (2x2 MIMO) technologies and higher order modulation (64 QAM). With Dual Cell technology, these can be doubled.
Since 2011, HSPA+ has been very widely deployed amongst WCDMA operators with nearly 200 commitments.[7]

Dual-Cell HSDPA (DC-HSDPA)

Main article: High-Speed Downlink Packet Access#Dual-Cell
Dual-Cell HSDPA, part of 3GPP Release 8, is the natural evolution of HSPA by allowing a user to connect to two cells at once, thereby theoretically doubling the connection speeds for the user.[8] An HSPA+ network can theoretically support up to 28 Mbit/s and 42 Mbit/s with a single cell although real life speeds are far lower. Besides the throughput gain from doubling the number of cells to be used, some diversity and joint scheduling gains can also be achieved.[9] Dual-cell can particularly improve the QoS (Quality of Service) for end users in poor radio reception where they cannot benefit from the other WCDMA capacity improvements (MIMO and higher order modulations) due to poor radio signal quality. From Release 9 onwards it will be possible to use DC-HSDPA in combination with MIMO. The support of MIMO in combination with DC-HSDPA will allow operators even more capacity improvements within their network.

Dual-Cell HSUPA (DC-HSUPA)

Main article: DC-HSUPA
Similar enhancements as introduced with DC-HSDPA in the downlink for UMTS Release 8 are being standardized for UMTS Release 9 in the uplink, called Dual-Cell HSUPA.[10] applied to HSUPA UL physical channels and DPCCH. The standardisation of Release 9 was completed in December 2009.[11]

Multi-carrier HSPA (MC-HSPA)

The aggregation of more than two carriers has been studied and 3GPP Release 11 is scheduled to include 4-carrier HSPA. The standard is scheduled to be finalised in Q3 2012 and first chipsets supporting MC-HSPA in late 2013. Release 11 specifies 8-carrier HSPA allowed in non-contiguous bands with 4x4 MIMO offering peak transfer rates up to 672 Mbit/s.

See also

References

  1. ^ Nomor Research: White Paper "Technology of High Speed Packet Access", nomor.de
  2. ^ "GSM/3G Market Update". Global mobile Suppliers Association. June http://www.ericsson.com/ericsson/corpinfo/publications/review/2006_03/06.shtml.
  3. ^ Rogers.com
  4. ^ Starhub.com
  5. ^ Elisa.fi
  6. ^ Ericsson.com
  7. ^ http://www.gsacom.com/news/gsa_335.php4
  8. ^ Nomor Research White Paper: Dual-cell HSPA and its Evolution, nomor.de
  9. ^ R1-081546, “Initial multi-carrier HSPA performance evaluation”, Ericsson, 3GPP TSG-RAN WG1 #52bis, April, 2008
  10. ^ Nomor 3GPP Newsletter 2009-03: Standardisation updates on HSPA Evolution, nomor.de
  11. ^ 3GPP releases

Further reading

  • Martin Sauter: Communication Systems for the Mobile Information Society, John Wiley, September 2006, ISBN 0-470-02676-6

External links

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