O(log n)-Localized Algorithms on the Coverage Problem in Wireless Sensor Networks

Network lifetime is a critical issue in wireless sensor networks. In the coverage problem, sensors can be partitioned into many subsets to prolong network lifetime. These subsets are activated successively and each of them completely covers an interest region. Many centralized algorithms have been proposed to solve this problem. A very few distributed versions have also been presented but none of them obtains a good approximation ratio. In this paper, we first reduce the coverage problem to a related domatic number problem in directed graphs. We next prove the lower and upper bounds of this domatic number. Based on this proof, we present two localized and distributed algorithms to solve the coverage problem with an objective of maximizing network lifetime. The approximation ratio of these distributed algorithms is within a factor of O(log n). Theoretical analysis and performance evaluation results are also presented to verify our approach.