Global system for mobile communication

1. GSM
TECHNOLOGY

2. WHAT IS GSM?
GSM stands for Global System
for Mobile Communication.
It is a digital cellular technology used
for transmitting mobile voice and data
services. It was developed in order to
create a common European mobile
telephone standard but it has been
rapidly accepted worldwide. – Formerly
it was “Groupe Spéciale Mobile”
(founded in 1982) – now: Global
System for Mobile Communication.

3. WHY GSM?
 International roaming
 Digital system
 High degree of flexibility(open architecture that will
Support for new services)
 Low-cost mobile sets and base stations (BSs)
 High-quality speech
 Compatibility with Integrated Services Digital Network
(ISDN) and other telephone company services
Listed below are the features of GSM that account for its
popularity and wide acceptance.

4. GSM HISTORY
Years Events
1982 Conference of European Posts and Telegraph (CEPT) establishes a
GSM group .
1985 A list of recommendations to be generated by the group is accepted.
1987 Time Division Multiple Access (TDMA) is chosen as the access
method (with Frequency Division Multiple Access [FDMA]).
1988 GSM system is validated.
1989 The European Telecommunications Standards Institute (ETSI) was
given the responsibility of the GSM specifications.
2001 As of May 2001, over 550 million people were subscribers to mobile
telecommunications.

5. GSM ARCHITECTURE
BASE STATION
SUBSYSTEM
NETWORK SWITCHING
SUBSYSTEM
MOBILE
STATION

6. MOBILE STATION
 Mobile Equipment
o Portable hand held device
o Provides access to the various data
services
o Monitoring power and signal quality of
surrounding cells for optimum handover.
 Subscriber Identity Module (SIM)
o Allows user to send and receive calls.
o Protected by a password or PIN
o Can be moved from phone to phone
The MS consists of the physical equipment, and the SIM
card. It provides the air interface to the user in GSM
networks.

7. BASE STATION SUBSYSTEM
The BSS is composed of two parts:
o The Base Transceiver Station (BTS)
o The Base Station Controller (BSC)

8. NETWORK SWITCHING SUBSYSTEM
 Home Location Register
(HLR)
 Visitor Location Register
(VLR)
 Equipment Identity Register
(EIR)
 Authentication Center (AuC)
 Mobile Services Switching
Center (MSC)
The Network switching system (NSS), the main part of
which is the Mobile Switching Center (MSC), performs the
switching of calls between the mobile and other fixed or
mobile network users.

9. GSM NETWORK AREAS

10. ACCESS METHODS
TIME DIVISION MULTIPLE ACCESS

11. INCOMING AND OUTGOING CALLS
PSTN to MS: MS to PSTN:

12. GSM SERVICES
GSM offers three basic types of services:
 Telephony services or teleservices
• Voice Calls
• Videotext
• Short Text Messages
 Data services or bearer services
 Supplementary services
• Conferencing
• Call Waiting
• Call Hold
• Call Forwarding
• Number Identification

13. GSM BILLING
 Telephony Service
 GPRS Services
 SMS Service
 Supplementary service
GSM service providers are doing billing based on the
services they are providing to their customers. All the
parameters are simple enough to charge a customer for the
provided services.

14. APPLICATIONS
 Mobile telephony
 GSM-R
 Telemetry System
 Automatic meter
reading
 Home automation
 Value Added
Services