Bayesian Source Localization in Networks with Heterogeneous Transmission Medium

Abstract

Precise positioning and tracking information in networks with a heterogeneous transmission medium presents a novel networking paradigm. Most of the localization algorithms are vulnerable to the variations of signal propagation speed, dielectric constant, and path-loss coefficient resulting in unreliable location estimation. In this paper, we propose a novel robust probabilistic Bayesian-based approach using received-signal-strength (RSS) measurements with varying path-loss exponent in wireless networks with heterogeneous medium. An application of such a localization method is relative positioning of nodes in a wireless network with a heterogeneous medium such as gastrointestinal tract monitoring using wireless video capsule endoscopy. The results of this study showed that the localization root mean square error (RMSE) of our Bayesian-based method when a sensor node was covered by four anchors was 1.0 mm which is smaller than that of other existing localization approaches under the same conditions such as classical MDS (43.1 mm), dwMDS (24.7 mm), MLE (21.8 mm) and POCS (1.7 mm). Copyright © 2012 Institute of Navigation