Optimal and distributed algorithms for coverage hole healing in hybrid sensor networks

Network coverage is one of the most decisive factors for determining the efficiency of a WSN. In this paper, we focus on how to schedule mobile sensors in order to cope with coverage hole issues in a hybrid WSN containing both static and mobile sensors. To this end, we introduce a new metric, namely to maximise the minimum remaining energy of all moved sensors since the more energy remains, the longer the network can operate. Based on this metric, we propose an efficient coverage healing algorithm that always determines an optimal location for each mobile sensor in order to heal all coverage holes, after all mobile sensors locations and coverage holes are located. When the target area is too big, we present a scalable area-based algorithm which returns a near optimal solution. Furthermore, we also present a lightweight-distributed scheduling strategy for mobile sensors in case of small sensor failures.