Location discovery in wireless sensor networks using a two-stage simulated annealing

Abstract

Wireless Sensor Networks (WSN) monitor the physical world using small wireless devices known as sensor nodes. Location information plays a critical role in many of the applications where WSN are used. A widely used self-locating mechanism consists in equipping a small subset of the nodes with GPS hardware, while the rest of the nodes employ reference estimations (received signal strength, time of arrival, etc.) in order to determine their locations. Finding the location of nodes using node-to-noDe distances combined with a set of known noDe locations is referred to as Location Discovery (LD). The main difficulty found in LD is the presence of measurement errors, which results in location errors. We describe in this work an error model for the estimations, propose a two-stage Simulated Annealing to solve the LD problem using this model, and discuss the results obtained. We will put a special stress on the improvements obtained by using our proposed technique. ©Springer-Verlag Berlin Heidelberg 2009.