Islamic University-Gaza Faculty of Engineering Electrical & Computer Engineering Department Global System for Mobile Communication GSM Group Alaa Al-ZatmaHosam Al-Awaj Obada Abdullah Supervisor Dr. 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 networks Palestine 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 forwarding To 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 Services receive 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 Database Store 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 BTS EIR HLR VLR MSC ME SIM GMSC Abis Network Subsystem Base Station Subsystem Mobile Station PSTN ISDN,PSPDN CSPDN BTS BSC MSC M 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 number The mobile send the calculated number to the AuC If 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

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