An Algorithm For Mobile Location Estimation In A 3g Network

ABSTRACT

Locating the position of a mobile user with a high degree of accuracy is a trending research

interest. It holds the key to a breakthrough in many service challenges faced by operators in the

wireless communication industry. With a success in this field, it will be possible for call rates in

mobile phones to be charged based on the location a subscriber is calling from; fighting crimes

and delivering emergency services through the mobile network’s ability to detect the caller’s

position will be possible. Many techniques have been proposed or developed for locating the

position of a mobile station in a telecommunication network. Those in operation are mostly

handset-based and each technique has its limitations. These ranged from the degree of accuracy

of the location estimate and response time of the system, to the cost and ease of implementing

the technique. The same goes for the various algorithms employed by these techniques. This

work presents a novel network-based Time Difference of Arrival (TDOA) algorithm for use in

estimating the position of a caller in a 3G mobile network. It is based on geometric principles

and uses known network parameters to calculate the unknown positions of mobile users in the

network. The algorithm improved the accuracy in the estimated position of a mobile user without

incurring the mathematical complexities in hyperbolic trilateration methods conventionally used

by TDOA techniques. From the results of the simulation, the improvement in the accuracy of the

located coordinates of the mobile phone was up to 86.82% and 89.20% for the x and y

coordinates respectively. The method adds no modification in the available cellular infrastructure

and incurs no additional costs.