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.
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
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
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
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