A directional propagation model for locating mobile stations within a mobile phone network

Mobile location estimation is becoming a high value added service on cellular phone networks. Among different mobile location estimation methods, the one which estimates the location of Mobile Stations (MSs) with reference to an intrinsics of wireless communication, signal strengths, is able to be applied to different kinds of cellular network, and hence is more general. This approach makes use of a wave propagation model to perform location estimation. Most wave propagation models are non-directional. However, we found out that in estimating mobile location with reference to signal strength, the azimuth gain of directional antenna and environmental factors can help to improve the accuracy. In this paper, we report our study of a Directional Propagation Model (DPM) which enhanced the traditional propagation model with these factors. We experimented our model with 192,177 sets of real life data covering most parts of Hong Kong collected from a major mobile hone operator of Hong Kong. Results show that the DPM models have significant improvement over other existing location methods in terms of accuracy and stability.