GSM(Global system for mobile communication ) is a second generation cellular standard developed to cater voice services and data delivery using digital modulation.

1. PREPARED BY:
BHARTI
KAVIA
M.Tech ECE 1st year

2. OUTLINE

3. Cellular concept is one the most faster growing and demanding
in telecommunications application.
Most beneficial part of cellular concept is GSM(global system for
mobile communication).
 Developed by Group Spéciale Mobile (founded 1982) which was
an initiative of CEPT ( Conference of European Post and
Telecommunication )
Global System for Mobile (GSM) is a second generation cellular
standard developed to cater voice services and data delivery using
digital modulation.

4. Tele-services :
• Offered services
- Emergency calling
- Mobile telephony
Bearer or Data Services:
Include various data services for information transfer between GSM and
other networks like PSTN, ISDN etc at rates from 300 to 9600 bps.

5. • Short Message Service (SMS)
-160 character alphanumeric data
• Voice mailbox
Supplementary services:
• Call Waiting
• Call Hold
• Call Barring
• Call Forwarding
• Multi Party Call Conferencing

6. The GSM network is made up of geographic areas include
• cells:
- Cell is the area given radio coverage by one base transceiver
station.
• location areas(LAs).
-The location area is a group of cell. The area in which the
subscriber is paged.

7. • MSC/VLR service areas:
-an MSC/VLR service area represents the part of the GSM
network that is covered by one MSC .
-which is reachable.
Public landmobile network(PLMN) areas:
-PLMN service area is an area served by one network operator.

8.  Frequency band:
• Frequency range is from 1,850 to 1,990MHz.
 Duplex distance:
• Duplex distance is 80MHz.
• The distance between the uplink and downlink frequencies.
 Channel separation:
• The channel separation between adjacent carrier frequencies is
200KHz.
 Transmission rate:
• Transmission rateover the air bit rate is 270kbps

9. SIM ME BTS BSC MSC
HLR VLR
EIR AuC
PSTN
PLMN
Internet
Mobile
station
Base Station
Subsystem
Network Subsystem Other Networks

10. Mobile Station (MS)
• Mobile Equipment (ME)
• Subscriber Identity Module (SIM)
Base Station Subsystem (BSS)
• Base Transceiver Station (BTS)
• Base Station Controller (BSC)
Network Switching Subsystem(NSS)
• Mobile Switching Center (MSC)
• Home Location Register (HLR)
• Visitor Location Register (VLR)
• Authentication Center (AUC)
• Equipment Identity Register (EIR)

11. The MS consists of two parts: the subscriber identity module(SIM)
and the mobile equipment(ME).
In a broader definition, the MS also include a third part called
terminal equipment(TE), which can be a PDA or PC connected to
the ME. In this case, the first two parts are called mobile
terminal(MT).
An SIM can be :
• A smart card, usually the size of a credit card
• A smaller-sized “plug-in SIM”
• A smart card that can be perforated, which contains a plug-in SIM that
can be broken out of it

12. SUBSCRIBER IDENTITY MODULE(SIM)
• Smart card contains the International Mobile Subscriber Identity
(IMSI).
• It is protected by a personal identity number(PIN) between 4 to 8
digits in length.
• Can be moved from phone to phone – contains key information to
activate the phone.
MOBILE EQUIPMENT(ME)
• The ME contains the noncustomer-related hardware and software
specific to the radio interface.
• When the SIM is removed from an MS, the remaining ME can’t be
used reaching the services, except for emergency calls.

13. BASE TRANSCEIVER STATION (BTS):
• The BTS contains transmitter, receiver and signaling equipment
specific to the radio interface in order to contact the MSs.
• An important part of BTS is transcoder/rate adapter unit(TRAU) that
carries out GSM-specific speech encoding/decoding and rate
adaptation in data transmission.

14. BASE STATION CONTROLLER (BSC)
• The BSC is responsible for the switching functions in the BSS, and
is in turn connected to an MSC in the NSS.
• The BSC supports radio channel allocation/release and handoff
management.
• The BTS communicates with the BTSs using ISDN protocols via the
A-bis interface.
• A BSC is typically engineered at 80 percent utilization.

15. • The NSS supports the switching functions , subscriber profiles and
mobility management.
MOBILE SWITCHING CENTER (MSC)
• The interface follows a signaling protocol used in telephone network.
• An incoming call is routed to an MSC, unless the fixed network is able to
interrogate the HLR directly. That MSC is called gateway MSC(GMSC).
• Billing information and collection
• Mobility management
- Registration
- Location Updating
- Inter BSS and inter MSC call handoff

16. HOME LOCATION REGISTERS (HLR)
• HLR is a database used for mobile user management. All permanent
subscriber data are stored in this database.
• As soon as mobile subscriber leaves its current local area, the
information in the HLR is updated via VLR.
• database contains IMSI, MSISDN, location information and service
information.
VISITOR LOCATION REGISTERS (VLR)
• VLR is a temporary database of the service area visited by MS. All
subscriber data of an MS required for call handling and other purpose
are stored in VLR.
• Assigns a TMSI to each MS entering the VLR area which keeps on
changing.
• Controls those mobiles roaming in its area
• Database contains IMSI, MSISDN, Location Area and service information.

17. AUTHENTICATION CENTER (AUC)
• The authentication center is used in the security data management for
the authentication of subscribers.
• The AuC may be colocated with the HLR.
• Contains the algorithms for authentication as well as the keys for
encryption.
• Protects network operators from fraud.
EQUIPMENT IDENTITY REGISTER (EIR)
• Stores all devices identifications registered for this network.
• Database that is used to track handsets using the IMEI (International
Mobile Equipment Identity)
• Prevents calls from stolen, unauthorised or defective mobile devices

18. The GSM radio link uses both FDMA and TDMA technologies.
The 900 MHz frequency bands for the GSM downlink signal
and the uplink signal are 935-960 MHz and 890-915 MHz ,
respectively.
The frequency band is divided into 124 pairs of frequency
duplex channels with 200KHz carrier spacing.
Discontinuous transmission is used in GSM to save power
consumption of the MS.

19. wireless communication
Total mobility
Worldwide connectivity
High capacity
High transmission quality

20.  2nd Generation
• GSM -9.6 Kbps (data rate)
2.5 Generation ( Future of GSM)
• HSCSD (High Speed ckt Switched data)
• Data rate : 76.8 Kbps (9.6 x 8 kbps)

21. • GPRS (General Packet Radio service)
• Data rate: 14.4 - 115.2 Kbps
• EDGE (Enhanced data rate for GSM Evolution)
• Data rate: 547.2 Kbps (max)
3 Generation
• WCDMA(Wide band CDMA)
• Data rate : 0.348 – 2.0 Mbps