GSM ( GLOBAL SYSTEM FOR MOBILE )

GSM  ( GLOBAL SYSTEM FOR MOBILE )

It is a second generation cellular standard ( most famous working standard mobile phase )
It is developed to cater voice and data delivery
It is using digital modulation
The utility of gsm provides national and international roaming very simple and easy between mobile phone generator

GSM SERVICES 

• TELE SERVICE:-includes mobile phone ,emergency calling
• DATA SERVICE:-includes sms ,fax,electronic mail,voice mails
• SUPPLYMENTARY SERVICES:-incoming ,outgoing calls, call waiting ,call forwarding,call holding,conference etc

GSM ARCHITECTURE

• Network Sub system
• Radio sub system
• Operation maintenance sub system

NETWORK SUB SYSTEM
Network sub system perform :call processing , subscriber related function
It includes;-

1. MSC-mobile switching center
2. HLR-Home location register
3. VLR-Visitor location Register
4. AUC-Authentication center
5. EIR-Equipment identity register
6. GMSC-Gateway MSC

MSC:-Mobile switching center

function carried out these are listed

• Call processing :-includes control of data/voice call setup
• Operation and Maintenance Support :- data base management,traffic metering and measurement
• Internet Work:- Manges the interface b/w the GS network and PSTN
• When the MSC provides the interface with other network in the GSM network it is known as Gateway MSC

HLR
:-Home Location Register sub system reference database for subscriber parameter

• Mobile Subcriber roaming number
• Subscriber ID (IMSC & MSISDN )
• Current location of subscriber
• Subscriber status ( registered or unregistered)
• Automating Key and AUC functionality

VISITORS LOCATION REGISTER

• It provides local database for the subscribers where ever they are in physically located within PLMN
• It is local database and contains copy of most of the data stored in HLR
• It contain Mobile Status :- busy status,no answer
• Location area identifies LAI ,MSRNand TMSI

AUR

Authentication center subsystem

• It provides authentication and encryption parameter for the verification  of subscriber identity
• It ensure confidentiality of each cell
• It protect network operator from frauds found in today's cellular world

EIR
Equipment identity register sub system
It contain centralized database for validating international mobile equipment identity IMEI

RADIO SUB SYSTEM
Management of radio network and is controlled by msc
it consists of

• BSC: Base station controller
• BTS: Base transceiver station

BSC

• Base station controller sub system
• It is connected to MSC
• Controls one or more BTS
• Switches traffic and signalling b/w BTS and MSC

BTS
Base transceiver station sub system

• The BTS is networking component s of a mobile communication  system from which all signals are sent and received.
• A BTS is controlled by MSC
• A BTS is also called a base station(BS) and is commonly refered as a cell phone tower

OPERATION AND MAINTENANCE SUBSYSTEM

• Dynamic monitoring and controlling of network operation and maintenance data function
• Configuration management
• Fault report and alarm handling
• Performance supervision
• Storage of software and data
• Store data for minimum one year

Q.Explain the architecture of GSM in detail. (15mark)[B. Tech Degree VII Semester Special Supplementary Examination June 2012 CS/IT 703 ADVANCED COMPUTER NETWORKS (2006 Scheme)]