Passive Geolocation in a 4G WIMAX Single Base Station Scenario

Abstract

The proliferation of Fourth Generation (4G) mobile wireless networks has led to an increased demand for position-based services. In many densely populated environments, there is an abundance of base stations by which a mobile station may be passively geographically located (geolocated) using various techniques that require multiple base stations. Areas in which base station density is sparse may not possess the requisite number of base stations to perform such techniques and, therefore, require different methods by which to geolocate mobile stations. In this thesis, we present a passive geolocation scheme that only requires observation of the initial ranging information exchange between a mobile station and a single base station in order to determine a position estimate for the mobile station. The scheme is specifically applied to the Institute of Electrical and Electronics Engineers (IEEE) 802.16 Worldwide Interoperability for Microwave Access (WiMAX) 4G standard. The method is validated through computer simulation and field experimentation in an Alcatel-Lucent IEEE 802.16e-2005 deployed network. The mean geolocation error resulting from simulation and experimentation was 85 meters, which is a degradation of 58 meters compared to a three-base station scenario.