This document discusses geolocation systems and technologies used for determining the location of mobile devices. It provides an overview of the typical architecture of a mobile telecommunication network and geolocation system. It then describes several technologies used for geolocation including GPS, angle of arrival, time of arrival, and location tracking curves. It also discusses the need for tracking mobile devices and provides some references on geolocation research.

1. Presented By:
PRASANNA C NAIK
4CB11EC411
02/04/2014

2.  INTRODUCTION
 CONFIGURATION OF A TYPICAL MOBILE
TELECOMMUNICATION NETWORK.
 ARCHITECTURE OF A GEOLOCATION
SYSTEM
 TECHNOLOGIES USED FOR GEOLOCATION
 NEED FOR TRACKING
 REFFERENCE

3.  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

5.  A geolocation service provider provides
location information and location aware
sevices to subscribers.
 The service provider will contact the
location control center about the coordinates
of the mobile system (MS).
 The location control center will gather
information required to compute the MS’s
location.
GEOLOCATION SYSTEM
ARCHITECTURE [K0S00]

6. 1.HANDSET BASED MOBILE POSITIONING AND TRACKING
1.1 GLOBAL POSITIONING SYSTEM (GPS)
2. DIRECTION BASED GEOLOCATION
2.1 ANGLE OF ARRIVAL METHOD
3. DISTANCE BASED POSITIONING
3.1 TIME OF ARRIVAL(TOA)
3.2 TIME DIFFERENCE OF ARRIVAL(TDOA)
4. LOCATION TRACKING CURVE METHOD

7.  To locate the mobile telephone by
itself, the mobile telephone is provided
with a GPS receiver to calculate its
location.
 There should be an unobstructed line
of sight to four or more GPS satellites.
 GPS satellites broadcast signals from
space, which each GPS receiver uses
to calculate its three-dimensional
location (latitude, longitude, and
altitude) plus the current time
 GPS receivers are used in mobile
phones, vehicles, marine navigation
devices and military applications.

8.  This method calculates the angle of
arrival of signal receiving at the BS.
 When a mobile user switches the
system ON it receives the signal from
different base stations, may be 3 or 4
or more. The angle of arrival method
requires two or more base station for
the determination.
 It measures the direction of signal
falling on the base station and
measures the angle of incidence with
respect to a normal and determines
the position of the system.

9.  The TOA method calculates the distance
of a mobile telephone and a BS based
on the TOA of a signal transmitted from
the mobile telephone at the BS.
 It is assumed that the mobile telephone
is located at the intersection point of
three circles having the radius of the
distances between the BSs and the
mobile telephone.
 The distance is calculated by the
following equation,
Ri = C τi = sqrt ( (xi – X ) 2
+ (yi – Y) 2
) where,
C – Propagation speed of electromagnetic
wave,
τi – propagation of time from the mobile
telephone to ith
base station,
Xi, yi -- location of ith
base station,
X, Y – mobile position

11.  When curves are selected for all selected
BS pairs, the location data processor
obtains the intersection points among the
selected curves.
 As the selected curves do not intersect at
one point due to the multi-path fading or the
NLOS effects, the midpoint of these
intersection points is determined as the
location of the mobile telephone.
 The location data processor represents the
intersection points in the latitude and the
longitude coordinates and transmits the
position coordinates to the network and the
mobile telephone.

12. Emergency service for subscriber safety.
Location sensitive billing.
Cellular Fraud detection.
Intelligent transport system services.
Efficient and effective network performance
and management.

13.  J. Caffery, and G. Stuber Jr, “Vehicle location and tracking for IVHS in CDMA
micro-cells”, Proc. IEEE PIMRC, 1994.
 G. Morley, and W. Grover, “Improved location estimation with pulse-ranging in
presence of shadowing and multi-path excess-delay effects”, Electronics Letters,
vol.31, No.18, 1995.
 Sourabh Pawade, Pushkar Masodkar, Prof Pankaj Hedaoo/ International Journal
ofEngineering Research and Applications (IJERA) ISSN: 2248-962
www.ijera.comVol. 1, Issue 3, pp.1080-1087signals", Proc. SPIE Conf. Wireless
Technologies and