UREA: Uncovered Region Exploration Algorithm for reorganization of mobile sensor nodes to maximize coverage

The recent advances in radio and embedded system technologies have enabled the proliferation of wireless microsensor networks. Such wirelessly connected sensors are released in many diverse environments to perform various monitoring tasks. The effectiveness of these networks is determined to a large extent by the coverage provided by the sensor deployment. The positioning of sensors affect coverage, communication cost and resource management. In this paper we investigate two important aspects of non deterministic sensor node deployment in sensor network. We present a new algorithm called Uncovered Region Exploration Algorithm UREA as a sensor deployment strategy to enhance the coverage after an initial random deployment of sensors. UREA decides a new location based on the uncovered region around the node in consideration. Virtual Force Algorithm VFA designed for the same purpose, calculates new locations of a sensor node based on the locations of the remaining nodes. The performance of UREA is compared with that of VFA. It was observed that with the same number of sensor nodes, UREA provides better coverage than that by VFA in less number of iterations. UREA is found to be consistent and robust. During simulation, it is assumed that the sensor network is a bounded, homogeneous and mobile ad-hoc network. Once the effective sensor positions are identified, a one-time movement of each node is carried out to redeploy the sensors at these new positions. Simulation results clearly show that this onetime displacement of sensor benefits the deployed network so as to improve coverage. In non deterministic deployments, mobility feature of the mobile ad-hoc network can be best exploited to reposition the sensors so as to achieve the best network coverage.