- 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-compatibledigital mobile phonetechnology 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 3Gdefinition, [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
3GPPas 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 8PSKencoding, 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
Internetconnection. 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 EDGEwas added in Release 7 of the 3GPPstandard. 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.
EDGE/EGPRS is implemented as a
bolt-on enhancementfor 2Gand 2.5GGSM 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.
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 3Gnetwork, and has been accepted by the ITUas part of the IMT-2000family of 3Gstandards. 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
Modulationand Coding Schemes (MCS-1 to 9).
Asia and Far East
Bangladesh: Grameenphoneis the largest mobile operator in the country and today provides for more than 20 million subscribers an opportunity to communicate using EDGE.
China: China Mobilelaunched EDGE services in Guangdongprovince in 2005. Shanghai has good EDGE coverage through China Mobile (2007). China Unicomalso launched EDGE service in Shanghai.:* Hong Kong: Peoples; also CSL, under the brands 1O1Oand One2Free
India: MTNL, Bharti Airtel, !dea Vodafoneand Reliance-Smart-GSMhave 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 Indosatprovide 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 Mobileprovides an EDGE network
Nepal: Spice Nepal "Mero Mobile" has EDGE coverage in major cities
Pakistan: Mobilink, Warid and Ufoneare 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: DTACprovides 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.
Australia: Telstrahas 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
* Spectral efficiency comparison table
List of device bandwidths
* [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]
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