17-07-2012, 04:50 PM
Tracking And Positioning Of Mobile Systems In Telecommunication Networks
[attachment=27861]
INTRODUCTION
MOBILE TECHNOLOGY
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. Only condition is that no two adjacent
cells must have same frequencies. An MTSO
controls these BSs so that a subscriber can continue
his call without interruption while moving between
different cells. The MTSO can reduce the time
required for calling a subscriber by locating the cell
of the subscriber. In case of an emergency like a
fire, or a patient needing first aid treatment, the
mobile subscriber should be accurately located.
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-
TECHNOLOGIES USED FOR GEOLOCATION
A. HANDSET BASED MOBILE POSITIONING
AND TRACKING
1) GLOBAL POSITIONING SYSTEM (GPS)
A mobile telephone can be located by a
mobile telephone itself or through a mobile
telecommunication network. To locate the
mobile telephone by itself, the mobile
telephone is provided with a GPS receiver to
calculate its location in latitude and longitude
coordinates based on the location information
received from a satellite through the GPS
receiver.
Description
When a location service is requested about a
specific mobile telephone by a user or a network,
the location data processor draws two circles C1
and C2 with their respective centers set at BSs T1
and T2 based on the TOAs of a signal transmitted
from the corresponding mobile telephone M1 or
M2 to the two BSs T1 and T2 located near the
mobile telephone M1 or M2. The two circles C1
and C2 define a common chord L1.
CONCLUSION
Our proposal is advantageous in that the
location of a mobile telephone can be accurately
tracked even in the multi-path fading and the
NLOS environment, by using more accurate
tracking curves connecting the intersection points
among circles with the radii being the distances
between corresponding BSs and the mobile
telephone in a cellular mobile communication
system. We have described about accurate
positioning of mobile telephones, which can be
used for several applications. The important
considerations to be undertaken while selecting a
location based technology are location accuracy,
implementation cost, reliability, increasing
functionality.
[attachment=27861]
INTRODUCTION
MOBILE TECHNOLOGY
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. Only condition is that no two adjacent
cells must have same frequencies. An MTSO
controls these BSs so that a subscriber can continue
his call without interruption while moving between
different cells. The MTSO can reduce the time
required for calling a subscriber by locating the cell
of the subscriber. In case of an emergency like a
fire, or a patient needing first aid treatment, the
mobile subscriber should be accurately located.
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-
TECHNOLOGIES USED FOR GEOLOCATION
A. HANDSET BASED MOBILE POSITIONING
AND TRACKING
1) GLOBAL POSITIONING SYSTEM (GPS)
A mobile telephone can be located by a
mobile telephone itself or through a mobile
telecommunication network. To locate the
mobile telephone by itself, the mobile
telephone is provided with a GPS receiver to
calculate its location in latitude and longitude
coordinates based on the location information
received from a satellite through the GPS
receiver.
Description
When a location service is requested about a
specific mobile telephone by a user or a network,
the location data processor draws two circles C1
and C2 with their respective centers set at BSs T1
and T2 based on the TOAs of a signal transmitted
from the corresponding mobile telephone M1 or
M2 to the two BSs T1 and T2 located near the
mobile telephone M1 or M2. The two circles C1
and C2 define a common chord L1.
CONCLUSION
Our proposal is advantageous in that the
location of a mobile telephone can be accurately
tracked even in the multi-path fading and the
NLOS environment, by using more accurate
tracking curves connecting the intersection points
among circles with the radii being the distances
between corresponding BSs and the mobile
telephone in a cellular mobile communication
system. We have described about accurate
positioning of mobile telephones, which can be
used for several applications. The important
considerations to be undertaken while selecting a
location based technology are location accuracy,
implementation cost, reliability, increasing
functionality.