Prolonging the system lifetime and equalising the energy for heterogeneous sensor networks using RETT protocol

In some Wireless Sensor Network (WSN) deployments, nodes may be used for different purposes (sensing, data pre-processing, actuation, etc.). Even if such a network is organised into clusters, this creates heterogeneity in terms of energy capability, which needs to be managed and balanced in order to ensure proper sensing capability with maximised lifespan. In this paper, we present Routing based on Energy–Temperature Transformation (RETT), a protocol that transforms the expected lifetime of each node into an equivalent temperature, and then by using the heat conduction formulas, finds the hottest path for sending data to a data sink in order to equalise the residual energy throughout the WSN. We investigate RETT’s ability to cope with heterogeneity and investigate its resilience and scalability based on node density and network size through a simulation study. We find that RETT is well suited to managing energy in the heterogeneous WSN case.