The Impact of Proximate Base Station Measurements on Localizability in Cellular Systems

The ubiquity of cellular networks makes them a preferred choice for geolocation in places that lack GPS coverage. While the analysis of cellular-based geolocation has traditionally been driven by simulation-based approaches, the increasing irregularity in the base station (BS) locations facilitate the use of powerful mathematical tools from stochastic geometry for their performance analysis. In this paper, we examine the impact of proximate base station measurements on localizability (the ability to get a location fix) in cellular-based systems. By proximate base station measurements we mean any measurements which indicate that a specific base station is within a predefined distance to the mobile. In particular, we derive a mathematically tractable expression for localizability probability, where localizability is defined as the union of the two events: (i) at least L BSs are hearable at the device to be localized, and (ii) the nearest active BS is within a certain predefined distance from the device to be localized (i.e., there is a proximate BS). Using this result, we quantify the gains achieved in localizability by incorporating measurements from the proximate BS in the localization procedure.