Sweep Coverage with Faults

Time variant coverage, called sweep coverage in wireless sensor networks has got attention from various re-searchers in recent time. In this problem, a set of mobile sensors are collectively monitoring certain area of interest (AoI). In various applications periodic monitoring of the AoI is sufficient. For a given time period, the objective of the sweep coverage problem is to find minimum number of mobile sensors so that the periodic monitoring can be guaranteed. This problem has been studied by various researchers in the context of point, area and barrier coverage problems. The sweep coverage problem on a graph is studied in [11]. In this problem, for a given input graph, minimum number of mobile sensors must be deployed such a way that all nodes of the graph must be visited by at least one mobile sensor. The sweep coverage problem is NP-hard and can not be approximated within a factor of 2 [16]. In this paper, we propose a fault-tolerant sweep coverage algorithm. For a given integer, using our proposed algorithm, the non-faulty sensors adjusted their movement and guarantees sweep coverage of all the nodes of an undirected weighted graph if at most sensors becomes faulty.