Standing for Enhanced Data for Global Evolution, or Enhanced Data rates for GSM Evolution, depending on who you believe, EDGE is a high-speed mobile data standard, supported by both 3GPP and ETSI, which is intended to increase the speed of data throughput within a GSM and TDMA mobile networks.
By building upon enhancements already provided by the General Packet Radio Service,or GPRS, and the High Speed Circuit Switched Data,or HSCSD, technologies that are currently being deployed by many of the major mobile telecomms companies, EDGE allows transfer speeds of 48Kbps across the GSM network, giving a theoretical maximum wide reach speed of 384Kbps, and a local speeds of up to 2Mpbs, when all 8 GSM timeslot channels are used. This is a vast improvement on the original GSM data services which gave a maximum bit rate of 9.6 kbit/s, and actually makes it feasible to stream multimedia broadcasts and other broadband applications to mobile phones. This increase in bandwidth over that which is achievable by GSM, GPRS and HSCSD technologies is achieved by switching the old-style Gaussian minimum shift keying, GMSK modulation system, for a new system, called the 8-phase shift keying, 8-PSK, which can give a four fold increase in throughput.
EDGE was developed by Ericcson between 1997 and 1999 as an alternate technology for used by those who didn't win a license to operate within the UMTS/3G frequency range, and it is also currently being marketed as a stopgap to fill 'missing' bandwidth caused by the current delays to 3G network rollout. The main selling point is that it fits within the current GSM architecture and can utilise the same base stations. h downside is that the fact that it needs more of these stations to function due to its requirement for a higher radio signal quality than that which is found in current GSM networks, before this higher data throughput can be achieved.