Connectivity based location estimation scheme for wireless ad hoc networks

We propose a method to estimate the location of a mobile user. We assume that mobile users carry portable devices such as laptops or personal digital assistants equipped with off-the-shelf standard wireless interfaces. The infrastructure has a few fixed nodes whose locations are assumed to be known. The location estimates rely on neighborhood relationships gathered by each user through message exchanges over a wireless ad hoc network. We show that by incorporating non-neighbor constraints, one can substantially improve the accuracy of location estimation as compared to only utilizing neighbor relationships. We also compare our approach without the non-neighbor constraints with the results from a paper (Doherty, L. et al., Proc. INFOCOM, p.1655-63, 2001) based on the same model. Empirical evaluation of our algorithm for several numerical examples is also included.