SATELLITE COMMUNICATION &BROADCASTING GLOBAL SYSTEM FOR MOBILE (GSM) BY, A. POOJA SHUKLA ECE ‘B’ IV YEAR 190912066 SAVEETHA UNIVERSITY
HISTORY OF GSM GSM was first introduced in the European marketin 1991. In 1982, it was recognized as a standard for digitalwireless communications. GSM was first named as Group Special Mobile.
Figures: March 2005 Reliance 3% Spice MTNL BhartiAircel 4% 2% BSNL 4% Bharti 27% Hutch BPL 6% IDEA BPL IDEA Aircel 13% BSNL Spice Hutch 22% Reliance 19% MTNL
WHAT IS GSM….? GSM is a second generation cellular systemstandard. It was developed to solve the fragmentationproblems of the first cellular generation. It is an 1st cellular system to specify digitalmodulation and network level architectures andservices. It uses an 2G technology.
It is an open system and non propriety technology. The greatest feature of GSM is internationalroaming.
GSM SERVICES AND FEATURESGSM services and features are classified into threemajor types. They are shown below, Base GSM SMS Infrastructure Base Station Station1. Telephone Services SMSC HLR2. Data Services3. Supplementary ISDN Services
TELEPHONE SERVICES• It is also called as teleservices.• The teleservices provides the following services, voice calls videotext and facsimile short text messages (SMS)
DATA SERVICES• It is also called as bearer services.• They are limited to layers 1,2 and 3 of the OSImodel.• Services include packet switched protocols anddata rates from 300 bps to 9.6 kbps.• Data may be transmitted using either a transparentor nontransparent mode.
SUPPLEMENTARY SERVICES• This service is provided on top of data services orteleservices.• It includes the following features, multiparty services or conferencing call waiting call hold call forwarding call waiting caller identification
PSTN ISDN PDN BSCMS BTS MSC GMSCBTS BSC VLR MS BTS EIR AUC MS HLR
o GSM network can be divided into following broadparts, Mobile Station (MS) Base Station Subsystem (BSS) Network Switching Subsystem (NSS) Operation Support Subsystem (OSS)
o The components of GSM architecture include thefunctions of databases and messaging systems, Home Location Register Visitor Location Register Equipment Identity Register Authentication Center SMS serving Center Gateway MSC Charge Back Center Transcoder and adaption unit
GSM CHANNELS Downlink Channel s Uplink Physical Channel: Each timeslot on a carrier is referred to as a physical channel Logical Channel: Variety of information is transmitted between the MS and BTS. Different types of logical channels: Traffic channel Control Channel
GSM NETWORK AREAS The basic service areas of GSM are given below,1. Cell Service Area2. Location Area3. MSC Service Area4. PLMN Service Area
ADVANTAGES OF GSM Crisper, cleaner quieter calls Security against fraud and eavesdropping International roaming capability in over 100 countries Improved battery life Efficient network design for less expensive system expansion Efficient use of spectrum Advanced features such as short messaging and caller ID A wide variety of handsets and accessories High stability mobile fax and data at up to 9600 baud Ease of use with over the air activation, and all account information is held in a smart card which can be moved from handset to handset