Maximum Lifetime Strategy for Target Monitoring with Controlled Node Mobility in Sensor Networks with Obstacles.

In this paper, an efficient technique is proposed for a mobile sensor network used to monitor a moving target in a field with obstacles while the network lifetime is maximized. The main sources of energy consumption of the sensors in the network are sensing, communication, and movement. A graph is constructed and its edges are weighted properly based on the remaining energy of each sensor. This graph is subsequently employed to address the lifetime maximization problem by solving a sequence of shortest path problems, which can be solved using existing methods. The proposed technique determines a near-optimal relocation strategy for the sensors as well as an energy-efficient route to transfer information from the target to destination. This near-optimal solution is calculated in every time instant, using the information of the previous time step. It is shown that by choosing appropriate parameters, sensors' locations and the communication route from target to destination obtained by the proposed algorithm can be arbitrarily close to the optimal locations and route at each time instant. Simulation results confirm the effectiveness of the proposed technique.