Mobile positioning technology

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INTRODUCTION TO MOBILE TECHNOLOGY :


The mobile telecommunication network includes a several base stations (BSs) T 1 to T N for providing mobile telecommunication service to a mobile subscriber through a mobile telephone M1, a base station controller (BSC) for controlling the BSs T 1 to T N, and a mobile telephone switching office (MTSO) for connecting the BSC to another BTS or a PSTN (Public Switched Telephone Network). In a cellular mobile telecommunication network, the whole service area is divided into a several coverage areas having respective base stations (BS). Each BS coverage area is called a "cell." Each BS is provided with a frequency of a range between 450 to900 MHz. More than one cell can use same frequency.



NEED FOR GEO-LOCATION
One of the most powerful ways to personalize mobile services is based on location. The location based services, provides the subscribers very best of the service. Recent demands from new applications require positioning capabilities of mobile telephones or other devices. The ability to obtain the geo-location of the Mobile Telephone (MT) in the cellular system allows the network operators to facilitate new services to the mobile users. The most immediate motivation for the cellular system to provide MT position is enhanced in accident emergency services. The geo location of the mobile user could provide services like



ARCHITECTURE OF GEOLOCATION:
An example of geo location system architecture [KOS00] is shown in Figure. As we said earlier, in order to fix a call the subscriber we are calling must be located accurately. A geo location service provider provides location information and location aware services to subscribers.
Upon a request from a subscriber for location information about an MS, the service provider will contact a location control center querying it for the coordinates of the MS. This subscriber could be a commercial subscriber desiring to track a mobile device or a PSAP trying to answer an E-911 call