Maximum lifetime strategy for target monitoring in a mobile sensor network with obstacles

In this paper, an energy efficient technique is proposed for target monitoring in a mobile sensor network in the presence of obstacles. The main sources of energy consumption in a mobile sensor are sensing, communicating and movement. The objective is to maximize the lifetime of the network while monitoring the target. To this end, a graph is constructed and its edges are weighted according to the remaining energy of each sensor. The lifetime maximization problem is subsequently transformed into a shortest-path problem. The proposed technique provides an efficient relocation strategy for the sensors and an energy-efficient route to transfer information from the target to the destination in the presence of obstacles. It is shown that under certain conditions, the lifetime of the network under the proposed strategy is close to the maximum achievable time. Simulations demonstrate the effectiveness of the proposed technique.