03-01-2011, 02:16 PM
By:
Abhijeet Agarwal
Presentation_on_GSM_Network day2 comb of all slides FINAL.ppt (Size: 454.5 KB / Downloads: 268)
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.
GSM Services
Tele-services
Bearer or Data Services
Supplementary services
Tele Services
Telecommunication services that enable voice communication
via mobile phones
• Offered services
- Mobile telephony
- Emergency calling
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
Voice mailbox
Electronic mail
Supplementary Services
Call related services :
Call Waiting- Notification of an incoming call while on the handset
Call Hold- Put a caller on hold to take another call
Call Barring- All calls, outgoing calls, or incoming calls
Call Forwarding- Calls can be sent to various numbers defined by the user
Multi Party Call Conferencing - Link multiple calls together
CLIP – Caller line identification presentation
CLIR – Caller line identification restriction
CUG – Closed user group
GSM System Architecture-I
Mobile Station (MS)
Mobile Equipment (ME)
Subscriber Identity Module (SIM)
Base Station Subsystem (BSS)
Base Transceiver Station (BTS)
Base Station Controller (BSC)
Network Switching Subsystem(NSS)
Mobile Switching Center (MSC)
Home Location Register (HLR)
Visitor Location Register (VLR)
Authentication Center (AUC)
Equipment Identity Register (EIR)
System ArchitectureMobile Station (MS)
The Mobile Station is made up of two entities:
Mobile Equipment (ME)
2. Subscriber Identity Module (SIM)
Mobile Equipment
Portable,vehicle mounted, hand held device Uniquely identified by an IMEI (International Mobile Equipment Identity)
Voice and data transmission
Monitoring power and signal quality of surrounding cells for optimum handover
Power level : 0.8W – 20 W
160 character long SMS.
Subscriber Identity Module (SIM)
Smart card contains the International Mobile Subscriber Identity (IMSI)
Allows user to send and receive calls and receive other subscribed services
Encoded network identification details
Key Ki,Kc and A3,A5 and A8 algorithms
Protected by a password or PIN
Can be moved from phone to phone – contains key information to activate the phone