An Energy-Efficient Opportunistic Routing for Load-Balancing in Wireless Sensors Networks

Opportunistic routing has been widely approved because of its throughput improvement for wireless mesh networks; however, few researches focus on transforming its benefit into realizing energy efficiency for wireless sensor networks (WSNs). We notice that two common issues in fixed-path routing schemes, including single-path routing or multi-path routing, are that (1) a path may traverse through a fixed set of sensors, draining out their energy, and (2) packet retransmission over an unreliable link of any fixed-path may consume energy significantly. In this paper, we exploit two natural advantages of opportunistic routing, i.e., path diversity and the improvement of transmission reliability, to develop a distributed routing scheme (EFFORT) for prolonging the network-lifetime of a WSN. Unlike prior works on minimizing transmission delay in opportunistic routing, we propose a metric (called OEC) that assists each sensor in determining a suitable forwarding set for reducing the damage to the lifetime caused by each forwarding, and, thus, enable EFFORT to extend the network lifetime by implementing forwarder selection and relay prioritization based on OEC. Simulation results show that EFFORT achieves network-lifetime extension, as well as energy-cost minimization as compared with other routing protocols.