File:Rq.pdf

Autonomous mobile entity navigation through dynamic and unknown environments is an essential part of many mission critical applications like search and rescue and fire fighting. The dynamism of the environment necessitates the mobile entity to constantly maintain a high degree of awareness of the changing environment. This criteria makes it difficult to achieve good navigation performance by using just on-board sensors and existing navigation methods and motivates the use of wireless sensor networks (WSNs) to aid navigation. In this paper, we present a novel approach that integrates a roadmap based navigation algorithm with a novel network query protocol called Roadmap Query (RQ). RQ enables collection of frequent, up-to-date information about the surrounding environment, thus allowing the mobile entity to make good navigation decisions. Simulation results under realistic fire scenarios show that RQ outperforms existing approaches with respect to both navigation performance and communication cost in highly dynamic environments. To validate our protocol further, we present a mobile agent based implementation of RQ along with preliminary experimental results, on Mica2 motes.