Upload
thomas-fowler
View
213
Download
1
Embed Size (px)
Citation preview
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