On maximizing the lifetime of delay-sensitive wireless sensor networks with anycast

Sleep-wake scheduling is an effective mechanism to prolong the lifetime of energy-constrained wireless sensor networks. However, it incurs an additional delay for packet delivery when each node needs to wait for its next-hop relay node to wake up, which could be unacceptable for delay-sensitive applications. Prior work in the literature has proposed to reduce this delay using anycast, where each node opportunistically selects the first neighboring node that wakes up among multiple candidate nodes. In this paper, we study the joint control problem of how to optimally control the sleep-wake schedule, the anycast candidate set of next-hop neighbors, and anycast priorities, to maximize the network lifetime subject to a constraint on the expected end-to-end delay. We provide an efficient solution to this joint control problem. Our numerical results indicate that the proposed solution can substantially outperform prior heuristic solutions in the literature, especially under the practical scenarios where there are obstructions in the coverage area of the wireless sensor network.