21-04-2012, 12:37 PM
Digital Cellular Networks
DIGITAL_CELLULAR_SYSTEM.ppt (Size: 132.5 KB / Downloads: 34)
What is GSM
Global System for Mobile Communication (GSM) is a second generation cellular standard developed to cater voice services and data delivery using digital modulation
GSM: History
• Developed by Group Special 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