Issue No.11 - November (2008 vol.7)
Wei Wang , National University of Singapore, Singapore
Vikram Srinivasan , National University of Singapore, Singapore
Kee-Chaing Chua , National University of Singapore, Singapore
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/TMC.2008.68
This paper considers the coverage problem for hybrid networks which comprise both static and mobile sensors. The mobile sensors in our network only have limited mobility, i.e., they can move only once over a short distance. In random static sensor networks, sensor density should increase as O(log L + k log log L) to provide k-coverage in a network with a size of L. As an alternative, an all-mobile network can provide k-coverage with a constant density of O(k), independent of network size L. We show that the maximum distance for mobile sensors is O( 1/sqrt(k) log^(4/3)(kL)). We then propose a hybrid network structure, comprising static sensors and a small fraction of O( 1/sqrt(k)) of mobile sensors. For this network structure, we prove that k-coverage is also achievable with a constant sensor density of O(k). Furthermore, for this hybrid structure, we prove that the maximum distance which any mobile sensor has to move is bounded as O(log^(3/4)L). We then propose a distributed relocation algorithm, where each mobile sensor only requires local information in order to optimally relocate itself. We verify our analysis via extensive numerical evaluations and show an implementation of the mobility algorithm on real mobile sensor platforms.
Distributed networks, Wireless communication
Wei Wang, Vikram Srinivasan, Kee-Chaing Chua, "Coverage in Hybrid Mobile Sensor Networks", IEEE Transactions on Mobile Computing, vol.7, no. 11, pp. 1374-1387, November 2008, doi:10.1109/TMC.2008.68