A Novel Coverage Enhancing Algorithm for Hybrid Wireless Sensor Networks

Providing field coverage is a key task in many sensor network applications. In some applications, the sensor field may have coverage holes due to random initial deployment of sensors and thus the desired level of coverage cannot be achieved. A hybrid wireless sensor network is a cost-effective solution to this problem by repositioning a portion of the mobile sensors to meet the network coverage requirement. This paper investigates how to redeploy mobile sensor nodes to improve network coverage in hybrid wireless sensor networks. We propose a novel coverage-enhancing algorithm for hybrid wireless sensor networks. It consists of two phases. In the first phase, we use a genetic algorithm to compute the candidate target positions of the mobile sensor nodes. In the second phase, we use an optimization scheme on the candidate target positions resulted from phase one to reduce the accumulated potential moving distance of mobile sensors, such that the exact mobile sensor nodes that need to be moved as well as their final target positions can be determined. Experimental results show that the proposed algorithm provided significant improvement in terms of area coverage rate, average moving distance, area coverage-distance rate and the number of moved mobile sensors than the GA, the PSO algorithm, and the virtual force algorithm.