Optimal Sleep/Wake Scheduling for Time-Synchronized Sensor Networks With QoS Guarantees

We study sleep/wake scheduling for low-duty cycle sensor networks. Our work explicitly considers the effect of synchronization error. We focus on a widely used synchronization scheme and show that its synchronization error is nonnegligible and using a conservative guard time is energy wasteful. We formulate an optimization problem that aims to set the capture probability threshold for messages from each individual node such that the expected energy consumption is minimized, and the collective quality of service (QoS) over the nodes is guaranteed. The problem is nonconvex. Nonetheless, we are able to obtain a solution with energy consumption that is provably at most 37% larger than the optimal solution. Simulations demonstrate the efficacy of our solution.