Enhanced Data Rates for GSM Evolution

Enhanced Data rates for Global Evolution (EDGE), Enhanced GPRS (EGPRS), or IMT Single Carrier (IMT-SC) is a backwards-compatible digital mobile phone technology that allows improved data transmission rates, as an extension on top of standard GSM. EDGE can be considered a 3G radio technology and is part of ITU's 3G definition, [http://www.itu.int/ITU-D/imt-2000/BackgroundIMT2000/IMT-2000.pdf] Dead link|date=September 2008] but is most frequently referred to as 2.75G. EDGE was deployed on GSM networks beginning in 2003— initially by Cingular (now AT&T) in the United States. [ [http://www.itu.int/ITU-D/imt-2000/MiscDocuments/IMT-Deployments-Rev3.pdf] Dead link|date=September 2008]

EDGE is standardized by 3GPP as part of the GSM family, EDGE is an upgrade that provides a potential three-fold increase in capacity of GSM/GPRS networks. The specification achieves higher data-rates by switching to more sophisticated methods of coding, within existing GSM timeslots. Introducing 8PSK encoding, EDGE is capable of delivering higher bit-rates per radio channel in good conditions.

EDGE can be used for any packet switched application, such as an Internet connection. High-speed data applications such as video services and other multimedia benefit from EGPRS' increased data capacity. EDGE Circuit Switched is a possible future developmentFact|date=September 2008.

Evolved EDGE was added in Release 7 of the 3GPP standard. This is a further extension on top of EDGE, providing reduced latency and potential speeds of 1Mbit/s by using even more complex coding functions than the 8PSK originally introduced with EDGE.

Technology

EDGE/EGPRS is implemented as a bolt-on enhancement for 2G and 2.5G GSM and GPRS networks, making it easier for existing GSM carriers to upgrade to it. EDGE/EGPRS is a superset to GPRS and can function on any network with GPRS deployed on it, provided the carrier implements the necessary upgrade.

Although EDGE requires no hardware or software changes to be made in GSM core networks, base stations must be modified. 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 GSM. New mobile terminal hardware and software is also required to decode/encode the new modulation and coding schemes and carry the higher user data rates to implement new services.

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, 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 data speeds 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 will therefore meets the International Telecommunications Union's requirement for a 3G 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.

EGPRS modulation and coding scheme (MCS)

In good radio conditions, EDGE can be four times as efficient as GSM. GSM use four coding schemes (CS-1 to 4) while EDGE provides nine Modulation and Coding Schemes (MCS-1 to 9).

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Asia

Asia and Far East

* Bangladesh: Grameenphone is the largest mobile operator in the country and today provides for more than 20 million subscribers an opportunity to communicate using EDGE.
* China: China Mobile launched EDGE services in Guangdong province in 2005. Shanghai has good EDGE coverage through China Mobile (2007). China Unicom also launched EDGE service in Shanghai.:* Hong Kong: Peoples; also CSL, under the brands 1O1O and One2Free
* India: MTNL, Bharti Airtel, !deaVodafone and Reliance-Smart-GSM have launched EDGE services. As of July 2007, BSNL's plans for introducing the service are pending since year 2003.district headquarters are currently under the reach of EDGE of BSNL [http://www.lightreading.com/document.asp?doc_id=128832 "BSNL Expansion Delayed Yet Again"] - Light Reading (July 11, 2007).] [cite web|url=http://www.3g.co.uk/PR/August2004/8193.htm |title=Siemens to EDGE Wireless to India's Bharti |publisher=3g.co.uk |date= |accessdate=2008-09-11] [cite web|url=http://www.3g.co.uk/PR/Feb2004/6560.htm |title=Nokia to Pilot Launch EDGE wireless services in Delhi |publisher=3g.co.uk |date= |accessdate=2008-09-11] [cite web|url=http://www.3g.co.uk/PR/August2004/8139.htm |title=EDGE Wireless Rolls In To India |publisher=3g.co.uk |date= |accessdate=2008-09-11]
* Indonesia: Telkomsel, Excelcom, and Indosat provide EDGE network
* Malaysia: DiGi has reasonable EDGE coverage, particularly in West Malaysia. Coverage in East Malaysia is currently limited to Kuching, Kota Kinabalu and several main town centres. DiGi streams its MobileTV service over its EDGE network; also Maxis Mobile provides an EDGE network
* Nepal: Spice Nepal "Mero Mobile" has EDGE coverage in major cities
* Pakistan: Mobilink, Warid and Ufone are proividing EDGE services in major cities. Telenor (Pakistan) provides EDGE coverage throughout Pakistan.
* Philippines: SMART has a wide EDGE coverage over the Philippine archipelago. PLDT, the parent company of SMART, also offers the PLDT WeRoam GPRS/EDGE wireless internet service
* Sri Lanka: Dialog GSM offers EDGE Coverage in Colombo. Tigo has islandwide EDGE coverage.
* Thailand: DTAC provides nationwide EDGE coverage. [ [http://www.dtac.co.th/en/network/gprs_edge.aspx] Dead link|date=September 2008] Advanced Info Service (AIS) also has a nationwide EDGE coverage. The third largest mobile operator, True Move, has deployed EDGE in the Bangkok Metropolitan Area.
* Vietnam: two GSM operators MobiFone and Viettel, who have nation-wide GPRS coverage, have both initiated EDGE field trials on their network since Q4 2007.

Australasia

* Australia: Telstra has nationwide EDGE coverage (approximately 96% of population).
* New Zealand: Nationwide EDGE coverage across main metropolitan areas on Vodafone NZ's mobilize network, for corporate and industrial use only. New Zealand's public use only available via Australia's Telstra network.
* Samoa: Digicel Pacific ("previously Telecom NZ") is still under initiation.
* Fiji : Digicel Fiji brought EDGE network to Fiji

ee also

* UMTS
* WiFi
* Spectral efficiency comparison table
* Novatel Wireless
* Option N.V.
* List of device bandwidths

References

External links

* [http://www.gsmworld.com/technology/edge/index.shtml GSM World: EDGE Platform]
* [http://www.ericsson.com/technology/whitepapers/3107_The_evolution_of_EDGE_A.pdf The Evolution of EDGE (PDF file – Ericsson White Paper)]
* [http://www.moldcell.md/eng/Services/Data/EDGE/ Moldcell: brief comparison of EDGE vs GPRS and other benefits.]
* [http://www.3gpp.org/ftp/Specs/html-info/21905.htm 3GPP Vocabulary]
* [http://teledict.blogspot.com/2007/10/enhanced-data-rates-for-global.html Teledict:EDGE]
* [http://www.gsacom.com/ The Global mobile Suppliers Association]