Practical scheduling for stochastic event capture in wireless rechargeable sensor networks

Existing scheduling schemes for stochastic event capture with rechargeable sensors either adopt simplified assumptions on event staying time or provide no performance guarantee. Considering the stochasticity of event staying time, we investigate the sensor scheduling problem aiming to maximize the overall Quality of Monitoring (QoM) in events capture application of wireless rechargeable sensor networks. We first provide a paradigm to calculate the QoM of a point of interests (PoI) and formulate the scheduling problem into an optimization problem. Although we find that that this problem is NP-complete, we prove that the objective function of the optimization problem is monotone submodular. Therefore we can express the problem as a maximization of a submodular function subject to a matroid constraint. Accordingly we can design an approximation algorithm which achieves a factor of 1/2 of the optimum. We evaluate the performance of our solution through simulations, and simulation results show that our scheme outperforms former works.