In line with the efforts of International Telecommunication Union (ITU) to provide global recommendations for IMT-2000, spectrum identification has been made, identifying parts of the 2 GHz band for IMT-2000 usage. Deploying IMT-2000 capable systems is however not limited to this spectrum band. The EDGE concept, a new TDMA-based radio access technology for both TDMA/136 and Global System for Mobile Communications (GSM) systems, provides thirdgeneration capabilities in the existing 800, 900, 1800, and 1900 MHz) frequency bands.
Enhanced Data rates for Global Evolution (EDGE) are a radio based high-speed mobile data standards. A technology that gives Global System for Mobile Communications (GSM) the capacity to handle services for the third generation of mobile network. EDGE was initially developed for mobile network operators who fail to win Universal Mobile Telephone System (UMTS) spectrum. EDGE gives incumbent GSM operators the opportunity to offer data services at speeds that are near to those available on UMTS networks. EDGE enables services like multimedia emailing, Web infotainment and video conferencing to be easily accessible from wireless terminals.
EDGE is a technology that gives GSM Networks the capacity to handle services for 3G. EDGE was developed to enable the transmission of large amounts of data at peak rates of up to 472kbps. Users should experience average speeds of 80 kbps to 130 kbps. EDGE deployment will begin in 2003 with full deployment finishing in 2004. EDGE devices are backwards compatible with GPRS and will be able to operate on GPRS networks where EDGE has not yet been deployed.
The Second Generation Evolution to EDGE:-
GSM and TDMA/136 are two second-generation cellular standards with worldwide success. Today GSM is used by more than 135 million subscribers in over 100 countries, and the TDMA/136 system family (including EIA-553 and IS-54) serves over 95 million subscribers in over 100 countries worldwide. Although speech is still the main service in these systems, support for data communication over the radio interface is being rapidly improved. The current GSM standard provides data services with user bit rates up to 14.4 kb/s for circuit switched data and up to 22.8 kb/s for packet data. Higher bit rates can be achieved with multislot operation, but since both high-speed circuit-switched data (HSCSD) and General Packet Radio Service (GPRS) are based on the original Gaussian minimum shift keying (GMSK) modulation, the increase of bit rates is slight.
EDGE uses high-level modulation in 200 kHz TDMA and is based on plug-in transceiver equipment. Universal Mobile Telecommunications Service (UMTS) is a new radio access network based on 5 MHz wideband code division multiple access (WCDMA). UMTS can be used in both new and existing spectra.
By adding third-generation capabilities to the GSM network implies the addition of packet switching, Internet access, and IP connectivity capabilities. With this approach, the existing mobile networks will reuse the elements of mobility support, user authentication/service handling, and circuit switching. Packet switching/IP capabilities are added to provide a mobile multimedia core network by evolving existing mobile telephony networks.
Implementing EDGE:
Implementation of EDGE by network operators has been designed to be simple. Only one EDGE transceiver unit will need to be added to each cell. With most vendors, it is envisaged that software upgrades to the Base Station Controller (BSCs) and Base Stations can be carried out remotely. The new EDGE capable transceiver can also handle standard GSM traffic and will automatically switch to EDGE mode when needed. Some EDGE capable terminals are expected to support high data rates in the downlink receiver only (i.e. high dates rates can be received but not sent), whilst others will access EDGE in both uplink and downlinks (i.e. high data rates can be received and sent).
The later device types will therefore need greater terminal modifications to both the receiver and the transmitter parts. EDGE is designed for migration into existing GSM and TDMA networks, enabling operators to offer multimedia and other IP-based services at speeds of up to 384 kbits/s (possibly 473 kbits/s in the future) in wide area networks.
An important attraction of EDGE is the smooth evolution and upgrade of existing network hardware and software, which can be introduced into an operator's current GSM or TDMA network in existing frequency bands.
In addition, the TDMA industry association, the Universal Wireless Communications Corporation, has introduced what it calls EDGE Compact.