Enhanced Data Rates for GSM Evolution
Encyclopedia
Enhanced Data rates for GSM Evolution (EDGE) (also known as Enhanced GPRS (EGPRS), or IMT Single Carrier (IMT-SC), or Enhanced Data rates for Global Evolution) is a digital mobile phone
Mobile phone
A mobile phone is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator...

 technology that allows improved data transmission rates as a backward-compatible extension of GSM. EDGE is considered a pre-3G radio technology and is part of ITU
Itu
Itu is an old and historic municipality in the state of São Paulo in Brazil. The population in 2009 was 157,384 and the area is 641.68 km². The elevation is 583 m. This place name comes from the Tupi language, meaning big waterfall. Itu is linked with the highway numbered the SP-75 and are flowed...

's 3G
3G
3G or 3rd generation mobile telecommunications is a generation of standards for mobile phones and mobile telecommunication services fulfilling the International Mobile Telecommunications-2000 specifications by the International Telecommunication Union...

 definition. EDGE was deployed on GSM networks beginning in 2003 — initially by Cingular (now AT&T) in the United States.

EDGE is standardized by 3GPP
3GPP
The 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, known as the Organizational Partners...

 as part of the GSM family.

Through the introduction of sophisticated methods of coding and transmitting data, EDGE delivers higher bit-rates per radio channel, resulting in a threefold increase in capacity and performance compared with an ordinary GSM/GPRS connection.

EDGE can be used for any packet switched
Packet switching
Packet switching is a digital networking communications method that groups all transmitted data – regardless of content, type, or structure – into suitably sized blocks, called packets. Packet switching features delivery of variable-bit-rate data streams over a shared network...

 application, such as an Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...

 connection.

Evolved EDGE
Evolved EDGE
Evolved EDGE is a bolt-on extension to the GSM mobile telephony standard, which extends the previous EDGE upgrade to achieve theoretical speeds of up to 1 Mbit/s with relatively low cost and ease...

 continues in Release 7 of the 3GPP
3GPP
The 3rd Generation Partnership Project is a collaboration between groups of telecommunications associations, known as the Organizational Partners...

 standard providing reduced latency and more than doubled performance e.g. to complement High-Speed Packet Access (HSPA
High Speed Packet Access
High Speed Packet Access is an amalgamation of two mobile telephony protocols, High Speed Downlink Packet Access and High Speed Uplink Packet Access , that extends and improves the performance of existing WCDMA protocols...

). Peak bit-rates of up to 1Mbit/s and typical bit-rates of 400kbit/s can be expected.

Technology

EDGE/EGPRS is implemented as a bolt-on enhancement for 2.5G GSM/GPRS networks, making it easier for existing GSM carriers to upgrade to it. EDGE is a superset to GPRS and can function on any network with GPRS deployed on it, provided the carrier implements the necessary upgrade.

EDGE requires no hardware or software changes to be made in GSM core networks. EDGE-compatible transceiver units must be installed and the base station subsystem needs to be upgraded to support EDGE. If the operator already has this in place, which is often the case today, the network can be upgraded to EDGE by activating an optional software feature. Today EDGE is supported by all major chip vendors for both GSM and WCDMA/HSPA.

Transmission techniques

In addition to Gaussian minimum-shift keying (GMSK), EDGE uses higher-order PSK/8 phase shift keying (8PSK) for the upper five of its nine modulation and coding schemes. EDGE produces a 3-bit word for every change in carrier phase. This effectively triples the gross data rate offered by GSM. EDGE, like GPRS, uses a rate adaptation algorithm that adapts the modulation and coding scheme (MCS) according to the quality of the radio channel, and thus the bit rate and robustness of data transmission. It introduces a new technology not found in GPRS, Incremental Redundancy
Hybrid ARQ
Hybrid automatic repeat request is a combination of high-rate forward error-correcting coding, and ARQ error-control for detectable-but-uncorrectable errors. In standard ARQ, redundant bits are added to data to be transmitted using an error-detecting code such as cyclic redundancy check...

, which, instead of retransmitting disturbed packets, sends more redundancy information to be combined in the receiver. This increases the probability of correct decoding.

EDGE can carry a bandwidth up to 236.8 kbit/s (with end-to-end latency of less than 150 ms) for 4 timeslots (theoretical maximum is 473.6 kbit/s for 8 timeslots) in packet mode. This means it can handle four times as much traffic as standard GPRS. EDGE meets the International Telecommunications Union's requirement for a 3G
3G
3G or 3rd generation mobile telecommunications is a generation of standards for mobile phones and mobile telecommunication services fulfilling the International Mobile Telecommunications-2000 specifications by the International Telecommunication Union...

 network, and has been accepted by the ITU as part of the IMT-2000 family of 3G standards. It also enhances the circuit data mode called HSCSD, increasing the data rate of this service.

EDGE modulation and coding scheme (MCS)

EDGE is four times as efficient as GPRS. GPRS uses four coding schemes (CS-1 to 4) while EDGE uses nine Modulation
Modulation
In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...

 and Coding Schemes (MCS-1 to 9).
 Coding and modulation 
scheme (MCS)
 Bit Rate 
(kbit/s/slot)
 Modulation
Modulation
In electronics and telecommunications, modulation is the process of varying one or more properties of a high-frequency periodic waveform, called the carrier signal, with a modulating signal which typically contains information to be transmitted...

 
MCS-1 8.80 GMSK
MCS-2 11.2 GMSK
MCS-3 14.8 GMSK
MCS-4 17.6 GMSK
MCS-5 22.4 8-PSK
MCS-6 29.6 8-PSK
MCS-7 44.8 8-PSK
MCS-8 54.4 8-PSK
MCS-9 59.2 8-PSK

Evolved EDGE

Evolved EDGE
Evolved EDGE
Evolved EDGE is a bolt-on extension to the GSM mobile telephony standard, which extends the previous EDGE upgrade to achieve theoretical speeds of up to 1 Mbit/s with relatively low cost and ease...

 improves on EDGE in a number of ways. Latencies are reduced by lowering the Transmission Time Interval
Transmission Time Interval
TTI, Transmission Time Interval, is a parameter in UMTS related to encapsulation of data from higher layers into frames for transmission on the radio link layer. TTI refers to the duration of a transmission on the radio link...

 by half (from 20 ms to 10 ms). Bit rates are increased up to 1 Mbit/s peak bandwidth and latencies down to 80 ms using dual carriers, higher symbol rate and higher-order modulation (32QAM and 16QAM instead of 8-PSK), and turbo code
Turbo code
In information theory, turbo codes are a class of high-performance forward error correction codes developed in 1993, which were the first practical codes to closely approach the channel capacity, a theoretical maximum for the code rate at which reliable communication is still possible given a...

s to improve error correction. And finally signal quality is improved using dual antennas improving average bit-rates and spectrum efficiency. EDGE Evolution can be gradually introduced as software upgrades, taking advantage of the installed base. With EDGE Evolution, end-users will be able to experience mobile internet connections corresponding to a 500 kbit/s ADSL service.

Networks

The Global mobile Suppliers Association (GSA) states that, as of January 2009, there were 413 GSM/EDGE networks in 177 countries, from a total of 441 mobile network operator commitments in 184 countries.

See also

  • HSDPA
  • List of device bandwidths
  • Novatel Wireless
    Novatel Wireless
    Novatel Wireless, Inc. is a company providing wireless broadband access solutions for use in portable personal computers, handheld computing and mobile devices. The company is perhaps best known for its MiFi line of compact wireless routers....

  • Spectral efficiency comparison table
  • UMTS
  • WiFi
    WIFI
    WIFI is a radio station broadcasting a brokered format. Licensed to Florence, New Jersey, USA, the station is currently operated by Florence Broadcasting Partners, LLC.This station was previously owned by Real Life Broadcasting...


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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