Issue and solution on coverage and performance for wireless sensor networks

To reduce energy consumption and extend lifetime is concernful in wireless sensor networks (WSNs). Besides, WSNs need to maintain coverage quality to capture the timely changed targets. A broad strategy is to select some sensors as working nodes to cover the monitored region while turning off redundant nodes. Therefore, scheduling node state and maintaining the coverage quality are two important aspects in WSNs. The contribution lies in two aspects in this paper. First, we present a mathematical model to compute minimum number of nodes under any given required coverage quality. Simulation results demonstrate that our approach is more accurate when the ratio of target region to sensor region is larger, and the complexity of proposed method is lower while the sensor's region can be perceived as arbitrary shape. Second, it is an NP-hard issue that network's coverage quality and ratio of sleeping nodes get to maximize together. The paper experiments by using genetic algorithm to try to solve this problem, which is significant in WSNs for practical applications.