Maximizing Lifetime of Wireless Sensor Networks with Mobile Sensor Nodes

In this paper we propose a new method utilizing mobile sensor nodes to prolong WSN lifetime while maintaining a large sensing area. We formulate this problem as a problem in finding the best positions for mobile sensor nodes to maximize the integral of the sensing area for the remaining lifetime of WSN. This problem implies the Euclidean Steiner Tree Problem, and is thus an NP-hard problem. We developed a GA(genetic algorithm)-based algorithm to find a near-optimal solution. Through simulations, we confirmed that the proposed method achieves better performance than a general local-search based approximation method for 100-node WSNs. We also confirmed that our method can find solutions within 5.1% difference from the optimal solution for 10-node WSNs.