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.