3G Wireless Demystified
Telecom experts provide the big picture of 3rd Generation universal mobile telecommunication systems (UMTS).
TABLE OF CONTENTS 3G Wireless Demystified
Enhanced Data for Global Evolution (EDGE)
EDGE is an evolved version of the global system for mobile (GSM) radio channels that uses new phase modulation and packet transmission to provide for advanced high-speed data services. The EDGE system uses eight level phase shift keying (8PSK) to allow one symbol change to represent 3 bits of information. This is three times the amount of information that is transferred by a standard two level GMSK signal used by first generation GSM systems. This results in a gross radio channel data transmission rate of 604.8 kbps and a net maximum delivered data transmission rate of approximately 474 kbps. The GPRS advanced packet transmission control system allows for constantly varying data transmission rates in either direction between mobile radios.
System Overview
The key changes to allow EDGE system operation are mobile telephones and base station transceivers that are capable of transmitting and receiving using the new 8PSK modulation. The EDGE system allows for mixing both types of modulation on a single radio channel. This means one time slot may use 8PSK modulation, and another time slot can use GMSK modulation. This mixing of technologies allows for existing GSM mobile telephones (non-EDGE compatible) to access the system. Although it is possible that single-mode EDGE mobile telephones may be built, most EDGE mobile telephones are capable of both GSM and EDGE transmission.
The highest EDGE data rates are permitted only when the radio channel conditions are optimum. Optimum radio channel performance usually occurs when the subscriber...
Copyright APDG 2002 under license agreement with Books24x7
