High Speed Packet Access

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HSPA+ indicator shown in notification shade on a 3G specified Android smartphone running version 6.0.1 (Marshmallow). Android hspa+ 2.png
HSPA+ indicator shown in notification shade on a 3G specified Android smartphone running version 6.0.1 (Marshmallow).

High Speed Packet Access (HSPA) [1] 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, 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. [2]

Mobile telephony collective term for the operation of mobile telephone devices

Mobile telephony is the provision of telephone services to phones which may move around freely rather than stay fixed in one location. Telephony is supposed to specifically point to a voice-only service or connection, though sometimes the line may blur.

3G is the third generation of wireless mobile telecommunications technology. It is the upgrade for 2G and 2.5G GPRS networks, for faster data transfer speed. This is based on a set of standards used for mobile devices and mobile telecommunications use services and networks that comply with the International Mobile Telecommunications-2000 (IMT-2000) specifications by the International Telecommunication Union. 3G finds application in wireless voice telephony, mobile Internet access, fixed wireless Internet access, video calls and mobile TV.

The 3rd Generation Partnership Project (3GPP) is a standards organization which develops protocols for mobile telephony. Its best known work is the development and maintenance of:



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 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, 3G+, or Turbo 3G. It allows networks based on the Universal Mobile Telecommunications System (UMTS) to have higher data speeds and capacity. HSDPA was introduced with 3GPP Release 5, which also accompanied an improvement on the uplink providing a new bearer of 384 kbit/s. The previous maximum bearer was 128 kbit/s. HSDPA also decreases latency and therefore the round trip time for applications. Evolved High Speed Packet Access (HSPA+), which was introduced in 3GPP Release 7, further increased data rates by adding 64QAM modulation, MIMO, and Dual-Carrier HSDPA operation. Even higher speeds of up to 337.5 Mbit/s are possible under 3GPP Release 11. [3]

The Universal Mobile Telecommunications System (UMTS) is a third generation mobile cellular system for networks based on the GSM standard. Developed and maintained by the 3GPP, UMTS is a component of the International Telecommunications Union IMT-2000 standard set and compares with the CDMA2000 standard set for networks based on the competing cdmaOne technology. UMTS uses wideband code division multiple access (W-CDMA) radio access technology to offer greater spectral efficiency and bandwidth to mobile network operators.

Latency is a time interval between the stimulation and response, or, from a more general point of view, a time delay between the cause and the effect of some physical change in the system being observed. Latency is physically a consequence of the limited velocity with which any physical interaction can propagate. The magnitude of this velocity is always less than or equal to the speed of light. Therefore, every physical system with any physical separation (distance) between cause and effect will experience some sort of latency, regardless of the nature of stimulation that it has been exposed to.

Evolved High Speed Packet Access technical standard for wireless, broadband telecommunication

Evolved High Speed Packet Access, or HSPA+, or HSPA(Plus), or HSPAP is a technical standard for wireless broadband telecommunication. It is the second phase of HSPA which has been introduced in 3GPP release 7 and being further improved in later 3GPP releases. HSPA+ can achieve data rates of up to 42.2 Mbit/s. It introduces antenna array technologies such as beamforming and multiple-input multiple-output communications (MIMO). Beam forming focuses the transmitted power of an antenna in a beam towards the user's direction. MIMO uses multiple antennas at the sending and receiving side. Further releases of the standard have introduced dual carrier operation, i.e. the simultaneous use of two 5 MHz carriers. The technology also delivers significant battery life improvements and dramatically quicker wake-from-idle time, delivering a true always-on connection. HSPA+ is an evolution of HSPA that upgrades the existing 3G network and provides a method for telecom operators to migrate towards 4G speeds that are more comparable to the initially available speeds of newer LTE networks without deploying a new radio interface. HSPA+ should not be confused with LTE though, which uses an air interface based on Orthogonal frequency-division multiple access modulation and multiple access.

The first phase of HSDPA was specified in the 3GPP release 5. Phase one 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 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, and fast hybrid automatic repeat request (HARQ). Further new features are the High Speed Downlink Shared Channels (HS-DSCH), quadrature phase shift keying, 16-quadrature amplitude modulation, and the High Speed Medium Access protocol (MAC-hs) in base station.

Higher-order modulation is a type of digital modulation usually with an order of 4 or higher. Examples: quadrature phase-shift keying (QPSK), and m-ary quadrature amplitude modulation (m-QAM).

Quadrature amplitude modulation (QAM) is the name of a family of digital modulation methods and a related family of analog modulation methods widely used in modern telecommunications to transmit information. It conveys two analog message signals, or two digital bit streams, by changing (modulating) the amplitudes of two carrier waves, using the amplitude-shift keying (ASK) digital modulation scheme or amplitude modulation (AM) analog modulation scheme. The two carrier waves of the same frequency are out of phase with each other by 90°, a condition known as orthogonality or quadrature. The transmitted signal is created by adding the two carrier waves together. At the receiver, the two waves can be coherently separated (demodulated) because of their orthogonality property. Another key property is that the modulations are low-frequency/low-bandwidth waveforms compared to the carrier frequency, which is known as the narrowband assumption.

The upgrade to HSDPA is often just a software update for WCDMA networks. In general, voice calls are usually prioritized over data transfer.

User equipment categories

The following table is derived from table 5.1a of the release 11 of 3GPP TS 25.306 [4] and shows maximum data rates of different device classes and by what combination of features they are achieved. The per-cell per-stream data rate is limited by the "maximum number of bits of an HS-DSCH transport block received within an HS-DSCH TTI" and the "minimum inter-TTI interval". The TTI is 2 ms. So, for example, Cat 10 can decode 27,952 bits/2 ms = 13.976 MBit/s (and not 14.4 MBit/s as often claimed incorrectly). Categories 1-4 and 11 have inter-TTI intervals of 2 or 3, which reduces the maximum data rate by that factor. 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. The data rates given in the table are rounded to one decimal point.

Further UE categories were defined from 3GGP Release 7 onwards as Evolved HSPA (HSPA+) and are listed in Evolved HSDPA UE Categories.


  1. 16-QAM implies QPSK support, 64-QAM implies 16-QAM and QPSK support.
  2. The maximal code rate is not limited. A value close to 1 in this column indicates that the maximum data rate can be achieved only in ideal conditions. The device is therefore connected directly to the transmitter to demonstrate these data rates.
  3. The maximum data rates given in the table are physical layer data rates. Application layer data rate is approximately 85% of that, due to the inclusion of IP headers (overhead information) etc.


GPRS-speed in a HSDPA plan O2-DE-UMTS-reduced-bandwidth-as-GPRS.png
GPRS-speed in a HSDPA plan

As of 28 August 2009, 250 HSDPA networks have commercially launched mobile broadband services in 109 countries. 169 HSDPA networks support 3.6 Mbit/s peak downlink data throughput. A growing number are delivering 21 Mbit/s peak data downlink and 28 Mbit/s.

Mobile broadband marketing term for wireless Internet access through a portable modem, USB wireless modem, or a tablet/smartphone or other mobile device

Mobile broadband is the marketing term for wireless Internet access through a portable modem, USB wireless modem, or a tablet/smartphone or other mobile device. The first wireless Internet access became available in 1991 as part of the second generation (2G) of mobile phone technology. Higher speeds became available in 2001 and 2006 as part of the third (3G) and fourth (4G) generations. In 2011, 90% of the world's population lived in areas with 2G coverage, while 45% lived in areas with 2G and 3G coverage. Mobile broadband uses the spectrum of 225 MHz to 3700 MHz.

CDMA2000-EVDO networks had the early lead on performance, and Japanese providers were highly successful benchmarks for it. But lately this seems to be changing in favour of HSDPA as an increasing number of providers worldwide are adopting it.

During 2007, an increasing number of telcos worldwide began selling HSDPA USB modems to provide mobile broadband connections. In addition, the popularity of HSDPA landline replacement boxes grew—providing HSDPA for data via Ethernet and WiFi, and ports for connecting traditional landline telephones. Some are marketed with connection speeds of "up to 7.2 Mbit/s", [5] which is only attained under ideal conditions. As a result, these services can be slower than expected, when in fringe coverage indoors.

High-Speed Uplink Packet Access (HSUPA) is a 3G mobile telephony protocol in the HSPA family. This technology was the second major step in the UMTS evolution process. It was specified and standardized in 3GPP Release 6 to improve the uplink data rate to 5.76 Mbit/s, [6] extending the capacity, and reducing latency. Together with additional improvements, this creates opportunities for a number of new applications including VoIP, uploading pictures, and sending large e-mail messages.

HSUPA has been superseded by newer technologies further advancing transfer rates. LTE provides up to 300 Mbit/s for downlink and 75 Mbit/s for uplink. Its evolution LTE Advanced supports maximum downlink rates of over 1 Gbit/s.


Enhanced Uplink adds a new transport channel to WCDMA, called the Enhanced Dedicated Channel (E-DCH). 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. Similarly to HSDPA, HSUPA uses a "packet scheduler", but it operates on a "request-grant" principle where the user equipment (UE) requests permission to send data and the scheduler decides when and how many UEs will be allowed to do so. A request for transmission contains data about the state of the transmission buffer and the queue at the UE and its available power margin. However, unlike HSDPA, uplink transmissions are not orthogonal to each other.

In addition to this "scheduled" mode of transmission, the standards allows a self-initiated transmission mode from the UEs, denoted "non-scheduled". The non-scheduled mode can, for example, be used for VoIP services for which even the reduced TTI and the Node B based scheduler will be unable to provide the very short delay time and constant bandwidth required.

Each MAC-d flow (i.e., QoS flow) is configured to use either scheduled or non-scheduled modes. The UE adjusts the data rate for scheduled and non-scheduled flows independently. The maximum data rate of each non-scheduled flow is configured at call setup, and typically not changed frequently. The power used by the scheduled flows is controlled dynamically by the Node B through absolute grant (consisting of an actual value) and relative grant (consisting of a single up/down bit) messages.

At the physical layer, HSUPA introduces new channels E-AGCH (Absolute Grant Channel), E-RGCH (Relative Grant Channel), F-DPCH (Fractional-DPCH), E-HICH (E-DCH Hybrid ARQ Indicator Channel), E-DPCCH (E-DCH Dedicated Physical Control Channel), and E-DPDCH (E-DCH Dedicated Physical Data Channel).

E-DPDCH is used to carry the E-DCH Transport Channel; and E-DPCCH is used to carry the control information associated with the E-DCH.

User equipment categories

The following table shows uplink speeds for the different categories of HSUPA.

Further UE categories were defined from 3GGP Release 7 onwards as Evolved HSPA (HSPA+) and are listed in Evolved HSUPA UE Categories.

Evolved High Speed Packet Access (HSPA+)

Evolved HSPA (a5lso known as HSPA Evolution, HSPA+) is a wireless broadband standard defined in 3GPP release 7 of the WCDMA specification. It provides extensions to the existing HSPA definitions and is therefore backward compatible all the way to the original Release 99 WCDMA network releases. Evolved HSPA provides data rates up to 42.2 Mbit/s in the downlink [6] and 22 Mbit/s in the uplink [6] (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]

See also

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Node B

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Etisalat Misr telecommunication company in Egypt

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  1. Nomor Research: White Paper "Technology of High Speed Packet Access", nomor.de
  2. "Universal Mobile Telecommunications System (UMTS); UE Radio Access capabilities" (PDF). ETSI. January 2014. Retrieved March 4, 2014.
  3. "HSPA". About Us.
  4. 3GPP TS 25.306 v11.0.0 http://www.3gpp.org/ftp/Specs/html-info/25306.htm
  5. "Vodafone UK - Maintenance". vodafone.co.uk.
  6. 1 2 3 Sadique, Abubaker. "Introduction to Generation in mobile Communication" . Retrieved August 3, 2018.
  7. "DC-HSPA+ brings 42 Mbps to 39 networks". 3GPP. Retrieved July 8, 2017.