Enhanced Data rates for GSM Evolution (EDGE) or Enhanced GPRS (EGPRS), is a digital mobile phone technology that allows it to increase data transmission rate and improve data transmission reliability. Although technically a 3G network technology it is generally classified as the unofficial standard 2.75G, due to its slower network speed. EDGE has been introduced into GSM networks around the world since 2003, initially in North America.
It 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 development.
EDGE Evolution continues in Release 7 of the 3GPP standard providing doubled performance e.g. to complement High-Speed Packet Access (HSPA)
Technology
EDGE/EGPRS is implemented as a bolt-on enhancement to 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 (BSS) needs to be upgraded to support EDGE. 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.
Classification
Whether EDGE is 2G or 3G depends on implementation. While Class 3 and below EDGE devices clearly are not 3G, class 4 and above devices perform at a higher bandwidth than other technologies conventionally considered as 2G (such as 1xRTT). Because of the variability, EDGE is generally classified as 2.75G network technology.
EDGE Evolution
EDGE Evolution improves on EDGE in a number of ways. Latencies are reduced by lowering the Transmission Time Interval by half (from 20 ms to 10 ms). Bit rates are increased up to 1 MBit/s peak speed and latencies down to 100 ms using dual carriers, higher symbol rate and higher-order modulation (32QAM and 16QAM instead of 8-PSK), and turbo codes to improve error correction. And finally signal quality is improved using dual antennas. An EDGE Evolution terminal or network can support some of these improvements, or roll them out in stages.
Networks
EDGE is actively supported by GSM operators in North America. Some GSM operators elsewhere view UMTS as the ultimate upgrade path and either plan to skip EDGE altogether or use it outside the UMTS coverage area. However, the high cost and slow uptake of UMTS have resulted in fairly common support for EDGE in the global GSM/GPRS market.
The following companies have EDGE networks in production:
