Roadmap Query Protocols for Sensor Network Guided Navigation in Dynamic Environments

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 makes it particularly difficult to achieve navigation using just on-board sensors and existing navigation methods. This motivates the integration of wireless sensor networks with navigation. The ease of deployment of a wireless sensor network along with its capability of collecting and delivering information about the surrounding environment makes it feasible to use wireless sensor networks to aid navigation in dynamic environments. In this paper, we present integrated navigation and network query strategies that achieve good navigation performance with low network communication cost. The reduced communication cost not only increases network lifetime but also improves navigation performance by increasing network responsiveness, which is required to maintain a high degree of awareness in dynamic environments. The proposed strategies include a roadmap based navigation strategy coupled with two different query strategies called Roadmap Query (RQ) and Robust Roadmap Query (RRQ). The query strategies are optimized for the roadmap based navigation strategy, and are shown, through simulation under realistic fire scenarios, to outperform existing approaches in terms of both navigation performance and communication cost. We also present a mobile agent based implementation of RQ and provide empirical results of its performance on a Mica2 mote testbed.