10-04-2012, 04:44 PM
GSM
RK-3 GSM Network.ppt (Size: 299 KB / Downloads: 312)
What is GSM
Global System for Mobile (GSM) is a second generation cellular standard developed to cater voice services and data delivery using digital modulation
GSM: History
Developed by Group Spéciale Mobile (founded 1982) which was an initiative of CEPT ( Conference of European Post and Telecommunication )
• Aim : to replace the incompatible analog system
• Presently the responsibility of GSM standardization resides with special mobile group under ETSI ( European telecommunication Standards Institute )
Full set of specifications phase-I became available in 1990
• Under ETSI, GSM is named as “ Global System for Mobile communication “
• Today many providers all over the world use GSM (more than 135
countries in Asia, Africa, Europe, Australia, America)
• More than 1300 million subscribers in world and 45 million subscriber in India.
Bearer Services
Include various data services for information transfer between GSM and other networks like PSTN, ISDN etc at rates from 300 to 9600 bps
Short Message Service (SMS)
up to 160 character alphanumeric data transmission to/from the mobile terminal
Unified Messaging Services(UMS)
Group 3 fax
Voice mailbox
Electronic mail
System ArchitectureBase Station Subsystem (BSS)
Base Station Subsystem is composed of two parts that communicate across the standardized Abis interface allowing operation between components made by different suppliers
Base Transceiver Station (BTS)
Base Station Controller (BSC)
System ArchitectureNetwork Switching Subsystem
Authentication Center (AUC)
Protects against intruders in air interface
Maintains authentication keys and algorithms and provides security triplets ( RAND,SRES,Kc)
Generally associated with HLR
Equipment Identity Register (EIR)
- Database that is used to track handsets using the IMEI (International Mobile Equipment Identity)
Made up of three sub-classes: The White List, The Black List and the Gray List
Only one EIR per PLMN
Advantages of GSM over Analog system
Capacity increases
Reduced RF transmission power and longer battery life.
International roaming capability.
Better security against fraud (through terminal validation and user authentication).
Encryption capability for information security and privacy.
Compatibility with ISDN,leading to wider range of services
GSM Applications
Mobile telephony
GSM-R
Telemetry System
- Fleet management
- Automatic meter reading
- Toll Collection
- Remote control and fault reporting of DG sets
Value Added Services