GSM - Digital Mobile Telephone Standard

General Information:

GSM (Global System for Mobile Communications) is a second-generation digital mobile telephone standard using a variation of Time Division Multiple Access (TDMA). It is the most widely used of the three digital wireless telephone technologies - CDMA (Code Division Multiple Access), GSM and TDMA. GSM digitizes and compresses voice data, then sends it down a channel with two other streams of user data, each in its own time slot. It operates at either the 900, 1800 or 1,900MHz frequency bands.

GSM was initially developed as a pan-European collaboration, intended to enable mobile roaming between member countries. As at March 2003, GSM digital wireless services were offered in some form in over 193 countries. In June 2002, about 69% of all digital mobile subscriptions in the world used GSM phones on GSM networks.


TECHNICAL DETAILS:

The GSM network can be divided into three broad parts -

* The subscriber carries the mobile station
* The base station subsystem controls the radio link with the mobile station
* The network subsystem performs the switching of calls between the mobile users and other mobile and fixed network users