Lifetime Maximization of Monitoring Sensor Networks

We study the problem of maximizing the lifetime of a sensor network assigned to monitor a given area. Our main result is a linear time dual approximation algorithm that comes arbitrarily close to the optimal solution if we additionally allow the sensing ranges to increase by a small factor. The best previous result is superlinear and has a logarithmic approximation ratio. We also provide the first proof of the NP completeness of this specific problem.