A novel routing metric for environmentally-powered sensors with Hybrid Energy Storage Systems

Sustainable wireless sensor networks (WSNs) are potential candidates for remote patient monitoring, monitoring the health of civil structures (e.g. bridges, office buildings, pipelines), environmental monitoring, industrial monitoring and surveillance. However, limited battery life has been a barrier for widespread deployment of such networks. This paper proposes the novel communication using hybrid energy storage system (CHESS) routing metric for networks such that each node has an hybrid energy storage system (HESS). An HESS is composed of a supercapacitor (SC) and a rechargeable battery (RB). SCs and RBs have quite different characteristics, the most important for WSNs being that RBs can be recharged 100 s of times, while SCs can be recharged on the order of a million times before failing. While HESS architectures have been used for wireless devices, no routing algorithm has considered how to exploit these two storage mechanisms to maximize network life. CHESS also allows control of the depth of discharge of the RB.