Global System for Mobile Communication

Global system for mobile communication (GSM) is a widely accepted standard for digital cellular communication, with a market share of 62. 2% and more than 251 networks in 108 countries. With more than 70 million subscribers, GSM provided a stable and comprehensive system specification for the transmission of mobile voice and data service (Zvonar 2). This standard was established during the early 1980’s by Conference of European Posts and Telecommunications (CEPT) as Groupe Special Mobile (GSM) in order to create a consistent and widely adaptable system for mobile communications.

Today, GSM has been used in the 900 Mhz, 1800 Mhz and 1900 MHz bands (Bedell 130). The GSM Network GSM recommends certain specifications that define the functions and interface of the network. There are three major systems in the GSM network: the switching system (SS), the base station system (BSS), and the operation and support system (OSS). (GSM Web Proforum Tutorials 4). The Switching System (SS) is responsible for the processing of calls and other subscriber related functions.

The SS includes the home location register (HLR), visitor location register (VLR), authentication center (AUC), mobile services switching center (MSC) and equipment identity register (EIR) as functional units. The HLR holds important user information. It manages and contains user profile, location and usage status. The MSC on the other hand handles the technical part. It has the important role of handling all the calls coming in and going out of the network.

The MSC is also responsible for toll ticketing, common channel signaling and network interfacing. When a subscriber moves to a different subscriber location, such as in roaming, the VLR performs the dynamic task of integrating subscriber information from the HLR to the current MSC. The AUC controls the security of the network by ensuring the confidentiality of user information. On the technical side, the EIR stores important information about the equipments to prevent calls from stolen or unidentified mobile stations.

(GSM Network Architecture) The Base Station System (BSS) is composed of the base station controller (BSC), the base transceiver station (BTS) and the air interface. At the base station, The BTS consists of an antenna and a radio transceiver. The transceiver defines the cell coverage area and the mobile protocols. The BSC handles the various BTS and controls and coordinates these. The BSC also regulates the transmit power levels of the handsets and towers. (Bedell 132).

The operations and maintenance center (OMC) connects all equipment in the switching system and the base station controllers. The implementation of this OMC is called the operation and support system (OSS). The OSS is used by the network operator to monitor and control the network system. The OSS provides an overview of the network and it provides a platform for the maintenance of activities of the different operators and organizations. (GSM Web Proforum Tutorials 6). All these systems create a widely effective standard for mobile communications.

As more improvements have been made such as the GPRS and EDGE technology, GSM remains the enduring standard for telecommunications. Works Cited Bedell, P. Wireless Crash Course McGraw-Hill Professional, 2005 Zvonar, Z. , Jung, P. , Kammerlander K. GSM: evolution towards 3rd generation systems Springer 1999 Global System for Mobile Communication. Web Proforum Tutorials. The International Engineering Consortium. http://www. iec. org GSM Network Architecture. http://www. wifinotes. com/mobile-communication-technologies/gsm-architechture. html