Max-SNR Opportunistic Routing for Large-Scale Energy Harvesting Sensor Networks

Providing sensors with adequate energy in large-scale wireless sensor networks (WSNs) over long periods is a major bottleneck in their implementation. In this regard, energy harvesting (EH), i.e., capturing energy from ambient renewable energy sources, is a promising solution for low-power and low data-rate WSNs. The randomness in the energy available forces the redesign of WSN protocols. Our specific interest here is to enable the delivery of sensed data to a fusion center (FC) in a large-scale EH-WSN. We propose a novel, energy-aware, opportunistic routing protocol in a large-scale EH-WSN requiring multi-hop communication. In choosing the best forwarding partner, our scheme considers the energy available at sensor nodes, their distances from the FC and also the amount of data to be transmitted. Our protocol requires no prior knowledge of the network topology. We provide a mathematical analysis of our routing protocol to confirm the achieved numerical results. As our results show, the proposed protocol significantly increases data delivery as compared to the state-of-the-art technologies. We also introduce an EH-aware manner for distributing sensors in the environment such that all nodes have approximately equal transmission load independent of their locations, which significantly increases the data delivery ratio.