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Tracking and positioning of mobiles in
telecommunication
Mobile positioning technology has become an important area of research,
for emergency as well as for commercial services. Mobile positioning in
cellular networks will provide several services such as, locating stolen
mobiles, emergency calls, different billing tariffs depending on where the
call is originated, and methods to predict the user movement inside a
region.
The evolution to location-dependent services and
applications in wireless systems continues to require the development of
more accurate and reliable mobile positioning technologies. The major
challenge to accurate location estimation is in creating techniques that
yield acceptable performance when the direct path from the transmitter to
the receiver is intermittently blocked.
This is the Non-Line-Of-Sight (NLOS) problem, and it is
known to be a major source of error since it systematically causes mobile
to appear farther away from the base station (BS) than it actually is,
thereby increasing the positioning error.
In this paper, we present a simple method for mobile telephone tracking
and positioning with high accuracy. Our paper presents the location of a
mobile telephone by drawing a plurality of circles with the radii being
the distances between a mobile telephone and a several base stations (it
will be found using Time Of Arrival (TOA)) and the base stations at their
centers, and using location tracking curves connecting the intersection
points between each circle pair instead of the common chords defined by
the circles. We use location tracking curves connecting the intersection
points of the two circles which will be drawn by ordinary TOA method,
instead of the common chord as in TDOA
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