Extending network lifetime in wireless sensor networks using power-aware geographic routing

Abstract

Wireless Sensor Networks (WSNs) use geographic routing to deliver measurement data to one or more sink nodes. In employing geographic routing, where data packets are forwarded along approximate geodesic (shortest) paths, WSNs can distribute the forwarding task unevenly between nodes. Nodes closest to the data sinks, or the geographic centre of the network coverage area, as well as nodes at the periphery of void areas, carry significantly more traffic. Consequently, their batteries deplete at a faster rate than the remaining nodes, causing void areas to form and grow, thus decreasing the overall network lifetime below its potential value. This thesis proposes a novel power-aware routing protocol inspired by the propagation of light-rays in graded-index media, aiming to balance the load over the network and to extend the overall network lifetime with minimal, local coordination overheads only. The idea has been implemented in a custom-built network simulator, where two versions of the algorithm were constructed: Curvy routing, which uses a fixed refractive index distribution and Energy Aware routing, which takes into account energy level changes to update the refractive index. Comparisons have been made between those, a baseline protocol and existing solutions in the literature, where simulation results have shown that the proposed protocols perform better in sparse networks, providing a realistic and plausible solution which can be applied successfully in real-life scenarios