L2OR: Low-Cost Low-Complexity Opportunistic Routing for Wireless Sensor Networks

Opportunistic routing can greatly improve energy efficiency in wireless sensor networks (WSNs). An important challenge is the design of a coordination protocol to implement an effective relay selection and prioritization scheme to minimize expected cost. Many existing opportunistic routing protocols often assumed an ideal link-layer, and thus the computed forwarder list may be suboptimal. Worth noting that, the computation complexity of optimal result grows rapidly with size of candidate set when the nonideal link-layer conditions are taken into account. It is, however, not feasible for energy and processing capability constrained WSNs. To address this problem, we propose a low-cost low-complexity opportunistic routing (L2OR) protocol to achieve an energy-efficient data delivery over WSNs. Our research work begins with a thorough investigation and understanding of properties of forwarder list under nonideal link-layer conditions. On this basis, a low-complexity heuristic algorithm is designed to efficiently find a reasonable choice of forwarder list, with an objective of reducing the search space to the size of candidate set. We conduct theoretical analysis and a set of simulation experiments to evaluate the performance of our L2OR. It is shown that, when comparing to typical energy-aware opportunistic protocol, the L2OR can achieve performance improvement in terms of data transmission efficiency as well as energy consumption.