GSM (Global System for Mobile Communications) is a second-generation cellular technology standard that was first introduced in Europe in 1991. It was developed to address fragmentation issues with first-generation cellular networks and specifies digital network architectures and services. Key features of GSM include international roaming, telephone services like voice calls and SMS, data services up to 9.6 kbps, and supplementary services like call forwarding and caller ID. The GSM network architecture includes mobile stations, base stations, switching systems, databases, and messaging centers.

1. SATELLITE COMMUNICATION &
BROADCASTING
GLOBAL SYSTEM FOR MOBILE (GSM)
BY,
A. POOJA SHUKLA
ECE ‘B’ IV YEAR
190912066
SAVEETHA UNIVERSITY

2. HISTORY OF GSM
 GSM was first introduced in the European market
in 1991.
 In 1982, it was recognized as a standard for digital
wireless communications.
 GSM was first named as Group Special Mobile.

3. Figures: March 2005
Reliance
3%
Spice MTNL Bharti
Aircel
4% 2% BSNL
4% Bharti
27% Hutch
BPL
6% IDEA
BPL
IDEA Aircel
13%
BSNL Spice
Hutch 22% Reliance
19%
MTNL

4. WHAT IS GSM….?
 GSM is a second generation cellular system
standard.
 It was developed to solve the fragmentation
problems of the first cellular generation.
 It is an 1st cellular system to specify digital
modulation and network level architectures and
services.
 It uses an 2G technology.

5.  It is an open system and non propriety technology.
 The greatest feature of GSM is international
roaming.

6. GSM SERVICES AND FEATURES
GSM services and features are classified into three
major types. They are shown below,
Base GSM SMS Infrastructure Base
Station Station
1. Telephone Services SMSC
HLR
2. Data Services
3. Supplementary ISDN Services

7. TELEPHONE SERVICES
• It is also called as teleservices.
• The teleservices provides the following services,
 voice calls
 videotext and facsimile
 short text messages (SMS)

8. DATA SERVICES
• It is also called as bearer services.
• They are limited to layers 1,2 and 3 of the OSI
model.
• Services include packet switched protocols and
data rates from 300 bps to 9.6 kbps.
• Data may be transmitted using either a transparent
or nontransparent mode.

9. SUPPLEMENTARY SERVICES
• This service is provided on top of data services or
teleservices.
• It includes the following features,
 multiparty services or conferencing
 call waiting
 call hold
 call forwarding
 call waiting
 caller identification

10. GSM SYSTEM ARCHITECTURE

11. PSTN
ISDN
PDN
BSC
MS BTS
MSC
GMSC
BTS BSC
VLR
MS
BTS EIR
AUC
MS HLR

12. o GSM network can be divided into following broad
parts,
 Mobile Station (MS)
 Base Station Subsystem (BSS)
 Network Switching Subsystem (NSS)
 Operation Support Subsystem (OSS)

13. o The components of GSM architecture include the
functions of databases and messaging systems,
 Home Location Register
 Visitor Location Register
 Equipment Identity Register
 Authentication Center
 SMS serving Center
 Gateway MSC
 Charge Back Center
 Transcoder and adaption unit

14. GSM OPERATION
Speech Speech
Speech coding Speech decoding
13 Kbps
Channel Coding Channel decoding
22.8 Kbps
Interleaving De-interleaving
22.8 Kbps
Burst Formatting Burst Formatting
33.6 Kbps
Ciphering De-ciphering
33.6 Kbps
Radio Interface
Modulation Demodulation
270.83 Kbps

15. GSM CHANNELS
Downlink
Channel
s
Uplink
 Physical Channel: Each timeslot on a carrier is
referred to as a physical channel
 Logical Channel: Variety of information is
transmitted between the MS and BTS. Different types
of logical channels:
 Traffic channel
 Control Channel

16. GSM NETWORK AREAS
 The basic service areas of GSM are given below,
1. Cell Service Area
2. Location Area
3. MSC Service Area
4. PLMN Service Area

17. GSM FRAME STRUCTURE

18. ADVANTAGES OF GSM
 Crisper, cleaner quieter calls
 Security against fraud and eavesdropping
 International roaming capability in over 100 countries
 Improved battery life
 Efficient network design for less expensive system
expansion
 Efficient use of spectrum
 Advanced features such as short messaging and caller ID
 A wide variety of handsets and accessories
 High stability mobile fax and data at up to 9600 baud
 Ease of use with over the air activation, and all account
information is held in a smart card which can be moved
from handset to handset

19. THANK YOU…..!!!