Islamic University-GazaIslamic University-GazaFaculty of EngineeringFaculty of EngineeringElectrical & Computer Engineering DepartmentElectrical & Computer Engineering Department

Global System for Mobile Communication

GSMGroup

Alaa Al-Zatma Hosam Al-Awaj

Obada Abdullah

SupervisorDr. Basil Hamad

Contents

Introduction to GSM

Services provided by GSM

Architecture of GSM Network

Cells & its types

Calling with GSM

Security of GSM

Conclusion

Introduction to GSM

GSM is a digital cellular communications system In early of 1982, the standard GSM was formed.More than 800 million end users in 193 countries over 550 networksPalestine

JAWWAL use GSM

More ..

Provides a best cellular service in best voice and speed of connection

More security

Compatibility

Use TDMA or CDMA to increase capacity

Services provided by GSM

Call waiting & Call hold– If you are using the phone, Call Waiting will

alert you to a second caller. You need never miss an incoming call.

– Use Call Hold to put the person you are talking to on hold so you can call another party, and then switch between the two calls.

Call forwardingTo divert incoming calls to another number. Calling line identity (CLI)CLI displays the number (name if stored on your phone) of the incoming call.

Cont..

SMS (short messaging service)

allow you to send & receive text messages on your phone

Data Servicesreceive and send data

GSM currently has a data transfer rate of 9.6 kbps.

New developments which push up data transfer rates for GSM users like:

HSCSD (high speed circuit switched data)

GPRS (general packet radio service) are now available.

Architecture of GSM Network

Base Transceiver Station: Control the frequencies Its task is transmitting

& receiving for mobile

Mobile services Switching Center •Backbone of GSM Network•Advanced digital divider manager of BSCs•Manage, prepare, control, and passing the call through the GSM network

Home Location Register:It has a very important DatabaseStore information about

subscribers belonging the coverage area of MSC

stores the current location of these subscribers and the services to which they have access

Visitor Location Register: contains temporary

information from a subscriber’s HLR

Authentication Center: used for security purposes provides the parameters

needed for authentication and encryption functions

Equipment Identity Register :used for security purposes

containing information about the mobile equipments

Gateway Mobile services Switching Center :

It is an interface between the mobile cellular network and the PSTN

Manage the outer communications (Roaming)

Base Station Controller:controls a group of BTS manages BTS radio

resources It is principally in

charge of handovers

Mobile Station:Consist of:•mobile equipment•a smart card called the Subscriber Identity Module (SIM)

The cell: It’s the main unit of cellular system

Identified by its Cell Global Identity number (CGI)

Corresponds to the radio coverage of BTS

Types of cells are used: Macro cells:

large cells for remote and sparsely populated

areas

Micro cells:

used for densely populated areas

splitting the existing areas into smaller cells

Cells

Location Area (LA)Defined as group of cells in the network

The subscriber's location is known in this area and store in VLR

If the subscriber transported from Location to another VLR must have a report of subscriber's new location

Calling with GSM ..

Your mobile call the cellular phone’s network and send it to nearest tower

The tower transmit the waves to the switchboard

If you call Telephone the switchboard transmit your call to PSTN

If you call another mobile, then the switchboard transmit the wave to the nearest tower of another mobile

If the caller are increase, the company must be increase the towers to make fine calling

So you can see small towers in high buildings and centers, etc..

Handover

Handover is the switching of an on going call to a different channel or cell.

Type of handover there are four different type of handover in which

involve transferring a call between :

BSC

BSC

BTS

BTS EIR

HLR VLR

MSCME

SIM

GMSCAbis

Network SubsystemBase Station Subsystem

Mobile

Station

PSTN

ISDN,PSPDN

CSPDN

BTS

BTS

BSC

BSC

MSCM S C

Why authentication ?Authentication involves two functional entities, the SIM card, (AuC). Each subscriber has a secret key which copied in the SIM card, (AuC). The AuC generates a random number and it sends to the mobile. Both the mobile and the AuC apply these number to the ciphering algorithm called A3, to calculate a third numberThe mobile send the calculated number to the AuCIf the two calculated number is the same then the subscriber is authenticated

Authentication & Security

cont.

Another level of security is performed on the mobile equipment itself each GSM equipment is identified by a unique (IMEI) number. A list of IMEIs in the network is stored in the (EIR) and they will divided in to three list White-listed the equipment is allowed to connect to the network. Grey-listed the equipment is under observation from the network for possible problems. Black-listed the equipment has either been reported stolen, or is not type approved; The terminal is not allowed to connect to the network.

Conclusion

We see the architecture of GSM network and the main function of the main part of this network.

each dialed call must pass through BTS;BSC and MSC.

GSM system characterized by high mobility so any one can travel during the time of the call.

Another important characteristic of GSM is the high security; so no one can listen to your call this is because of the random number.

There is no affect genetic material

Reference

http://www.myjawwal.com

http://www.luc.ac.be/~hbaerten/gsm/

http://www.gsmworld.com/

http://www.gsmag.com/

http://www.mobileworld.org/

http://kbs.cs.tu-berlin.de/~jutta/gsm/gsm-list.html

http://www.howstuffworkcom

THANK YOU