Delay-Constrained, Energy-Efficient Routing in Wireless Sensor Networks Through Topology Control

In this paper, we investigate the problem of finding energy-efficient paths for delay-constrained data in wireless sensor networks. This problem has been shown to be NP-complete and current solutions for this problem are inadequate, as they do not model the delays introduced by the channel access mechanisms. We present a heuristic solution for the aforesaid problem that employs topology control for sensor networks using 802.11 like channel access schemes. We propose a network architecture and a routing framework that enable us to model the access delays caused by the MAC layer. This in turn, allows us to obtain better estimates for the end-to-end delays along various paths. We identify a set of paths between the source and sink nodes, and index them in increasing order of their energy consumption. We then estimate the end-to-end delay along each of these ordered paths, and select the one with the lowest index that satisfies the delay constraint. Our studies show that the proposed framework achieves a good balance between latency introduced in the transfer and energy consumption, when compared with conventional solutions