The document provides an overview of the GSM technology. It discusses the history and evolution of GSM, introduces GSM services, and describes the architecture and components of GSM networks including the network subsystem, radio subsystem, and operation and maintenance subsystem. It also covers the process of transmitting speech via radio signals in GSM networks and provides examples of call routing procedures. Finally, it lists some advantages of GSM and discusses practical knowledge about optical fiber networks.

1. The GSM TechnoloGy
GloBAl SySTeM
FoR MoBIle
coMMUnIcATIon
Anshul Joshi
ECE-A
Roll No-17

2. conTenTS
• hISToRy & evolUTIon
• InTRodUcTIon
• GSM ARchITecTURe
• FRoM Speech To RAdIo
• cAll RoUTInG
• AdvAnTAGeS
• pRAcTIcAl KnowledGe AT BSnl.

3. hISToRy

4. Evolution From 1G
In 2001 the first commercial launch of 3G was done in
Japan. With 3G following services are available :
 Video Conferencing
 High speed Internet Access
Online Gaming

5. InTRodUcTIon
Global System for Mobile (GSM) is a second generation
cellular standard developed to cater voice services and data
delivery using digital modulation.
GSM SeRvIceS
TELE SERVICES : Includes mobile phones, emergency calling etc.
DATA SERVICES : Includes SMS (Short message service), fax,
voicemail, electronic mail.
SUPPLYMENTARY SERVICES : I/C & O/G calls, call forwarding,
call hold, call waiting, conference, etc.

6. GSM
NAetwRocrkh suIbT-syestecmTURe
Radio sub-system
Operation and maintenance sub-system

8. neTwoRK SUBSySTeM
Performs call processing and subscriber related
functions. It includes:
MSC: Mobile Switching Centre
HLR: Home Location Register
VLR : Visitor Location Register
AuC: Authentication Centre
EIR: Equipment Identity Register
GMSC:Gateway MSC.

9. Network
mobile switchiNg ceNtre subsystem
The functions carried out by the MSC are listed
below:
Call Processing
Call Switching
Operations And Maintenance Support
Internetwork Networking
When the MSC provides the interface with the other
networks in the GSM network it is known as a
Gateway MSC.

10. home locatioN register
Reference database for
subscriber parameters.
 Subscriber ID (IMSI & MSIN).
 Current location of subscriber.
 Subscriber status
(registered/unregistered)
 Authentication key and AUC
functionality.
 Mobile subscriber roaming
number.
Network
subsystem

11. • Provides local database
for subscriber when they
are away from home.
It contains:
• Mobile
status(busy/free/no ans)
• Location area identity(LAI)
• TMSI AND MSIN .
Network
Visitor locatioN register subsystem

12. autheNticatioN ceNtre
Network
subsystem
• Provides authentication and encryption.
• Ensures confidentiality of each cell.
• Protects network operators from frauds.
• Associated with HLR.
• Takes place each time the subscriber
initializes” on the system.

13. eQuiPmeNt iDeNtity register
• Centralized database for validating the
IMEI.
• It contains three lists-
 White List
 Black List
 Grey List
Network
subsystem

14. raDio subsystem
• Management of radio
network and is
controlled by a MSC .
One MSC controls many
radio subsystem.
It consists of :
 BSC: Base station
controller.
 BTS: Base transceiver
station.

15. base statioN coNtroller
 It is connected to MSC.
 Controls one or more BTS.
 Switches traffic and
signaling to/from BTSs and
MSC.
 Connects terrestrial circuits
and channels on air
interface.
 Controls handover
performed by BTS.
 Frequency allocation and
power control.
raDio
subsystem

16. base traNsceiVer statioN
• Maintains air interface and
minimize transmission
problems.
• Paging information.
• Radio level power control.
• BTS identification.
• Ciphering
• Speech processing.
raDio
subsystem

17. OPERATION AND MAINTENANCE SUBSYSTEM
Dynamic monitoring and controlling of
network.
Operation and maintenance data function.
Configuration management.
Fault report and alarm handling.
Performance supervision.
Storage of software and data.
Stores data for minimum one year.

18. FROM SPEECh TO RADIO TRANSMISSION
Blah... Blah... Blah... Blah… Blah… Blah...
Source Decoding
Channel Decoding
Deciphering
Burst De-formatting
ThE GSM TEChNOlOGY
Digitizing and
Source Coding
Channel Coding
Interleaving
Ciphering
Burst Formatting
Modulating Demodulating
De-interleaving

19. • Call Originating from MS
• Call termination to MS

20. OOUUTTGGOOIINNGG CCAAllll
1. MS sends dialed number to BSS
2. BSS sends dialed number to
MSC
3,4 MSC checks VLR if MS is
allowed the requested service. If
so, MSC asks BSS to allocate
resources for call.
5 MSC routes the call to GMSC
6 GMSC routes the call to local
exchange of called user
7, 8,
9,10 Answer back(ring back) tone
is routed from called user to MS
via GMSC,MSC,BSS

21. IINNCCOOMMIINNGG CCAAllll
1. Calling a GSM subscribers
2. Forwarding call to GSMC
3. Signal Setup to HLR
4. 5. Request MSIN from VLR
6. Forward responsible MSC
to GMSC
7. Forward Call to current
MSC
8. 9. Get current status of MS
10.11. Paging of MS
12.13. MS answers
14.15. Security checks
16.17. Set up connection

22. ADvANTAGES OF GSM
 Communication
– mobile, wireless communication, support for voice and data
services
 Total mobility
– international access, chip-card enables use of access points of
different providers.
 Worldwide connectivity
– one number, the network handles every location.
 High capacity
– better frequency efficiency, smaller cells, more customers per cell.
 High transmission quality
– high audio quality and reliability for wireless, uninterrupted phone
calls at higher speeds (e.g., from cars, trains).
• Security functions
– access control, authentication via chip-card and PIN

23. PRACTICAl KNOwlEDGE AT BSNl
Topics Covered-
Splicing
Breakage Of Optical Fiber
National Optical Fiber Network(NOFN)
BSNL Leased Line
Reliance Scenario

24.  Joining two fibers end to end using heat.
Minimize Scattering and Back Reflection.
Process:
• Striping
• Cleaning
• Cleaving
• Sliplicing
SPlICING

25. Breakage Of Optical fiBer
Two Equipments Used:
Optical Time Domain Reflectmeter
• Optoelectronic Instrument
• Characterize an Optical Fiber
• Optical Equivalent of ETDR
Rodometer
• Measures Distance

26. NOfN
To Connect 2.5L GP
Budget-20,000 Cr.
Started-01/04/13
Utilizing Existing Fibers N/W
NOFN Access To All Service Providers
e-Health, e-Education, e-Governance

27. BSNl leaSed liNeS
On Demand Data Lines
Varying Speed ( 64Kbps - 2Mbps)
Private Network
Services
• Speech Services
• Data Services
P2P
Private Data Network
Closed User Group

28. reliaNce SceNariO
Why Reliance is the first to launch 4G
service over a broader area?