Today’s fast growing world needs fast communication ,either it may be voice or data. This calls for a new technology which is faster than all existing technologies in mobile communication and hence can replace technologies like GPRS. Enhanced Data for Global Evolution(EDGE) is such a technology .EDGE is a member of global system for mobile communications(GSM). In short EDGE is a technology which enhances data rates for mobile communications.
EDGE not only enhances data rates but also intended for efficient spectrum utilization which it has passed successfully. This paper is intended for explaining how theoretical data rates of 384 kbps is possible with EDGE technique. And how enhanced data for global evolution (EDGE) can play an important role in the evolution toward wideband code division multiple access (WCDMA).And this paper also includes brief details on EDGE and modulation scheme used for EDGE. EDGE can be introduced in two ways: (1) as a packet-switched enhancement for general packet radio service (GPRS), known as enhanced GPRS or EGPRS, and (2) as a circuit-switched data enhancement called enhanced circuit-switched data (ECSD). My paper, however, will only discuss the packet switched enhancement, EGPRS. The purpose of this paper is to describe EDGE technology and how it leverage existing GSM systems and complements WCDMA for further growth.
EDGE is the next step in the evolution of GSM and IS-136. The objective of the new technology is to increase data transmission rates and spectrum efficiency and to facilitate new applications and increased capacity for mobile use .With the introduction of EDGE in GSM phase 2+,existing services such as GPRS and high-speed circuit switched data (HSCSD) are enhanced by offering a new physical layer. The services themselves are not modified. EDGE is introduced within existing specifications and descriptions rather than by creating new ones.
This paper focuses on the packet-switched enhancement for GPRS, called EGPRS.GPRS allows data rates of 115 kbps and, theoretically, of up to 160 kbps on the physical layer. EGPRS is capable of offering data rates of 384 kbps and, theoretically, of up to 473.6 kbps. A new modulation technique and error-tolerant transmission methods, combined with improved link adaptation mechanisms, make these EGPRS rates possible. This is the key to increased spectrum efficiency and enhanced applications, such as wireless Internet access, e-mail and file transfers.
GPRS/EGPRS will be one of the pacesetters in the overall wireless technology evolution in conjunction with WCDMA. Higher transmission rates for specific radio resources enhance capacity by enabling more traffic for both circuit- and packet-switched services. The goal of EDGE is to boost system capacity, both for real-time and best effort services, and to compete effectively with other third-generation radio access networks such as WCDMA and cdma2000.
Regarded as a subsystem within the GSM standard ,GPRS has introduced packet-switched data into GSM networks. Many new protocols and new nodes have been introduced to make this possible .EDGE is a method to increase the data rates on the radio link for GSM. Basically, EDGE only introduces a new modulation technique and new channel coding that can be used to transmit both packet-switched and circuit-switched voice and data services. EDGE is therefore an add-on to GPRS and cannot work alone. GPRS has a greater impact on the GSM system than EDGE has. By adding the new modulation and coding to GPRS and by making adjustments to the radio link protocols, EGPRS offers significantly higher throughput and capacity.
GPRS and EGPRS have different protocols and different behaviour on the base station system side .However, on the core network side, GPRS and EGPRS share the same packet-handling protocols and ,therefore, behave in the same way. Reuse of the existing GPRS core infrastructure (serving GRPS support node/gateway GPRS support node) emphasizes the fact that EGPRS is only an “add-on”to the base station system and is therefore much easier to introduce than GPRS.
In addition to enhancing the throughput for each data user, EDGE also increases capacity. With EDGE ,the same time slot can support more users. This decreases the number of radio resources required to support the same traffic, thus freeing up capacity for more data or voice services. EDGE makes it easier for circuit-switched and packet-switched traffic to coexist while making more efficient use of the same radio resources. Thus in tightly planned networks with limited spectrum, EDGE may also be seen as a capacity booster for the data traffic.