Sink Mobility Schemes in Wireless Sensor Networks for Network Lifetime Extension

Sensor nodes in Wireless Sensor Networks (WSNs) are normally battery-powered and remain stationary after deployment. When a sensor node runs out of energy it will no longer provide sensing and data processing. This can lead to a huge loss in the network due to the routing path re-allocation and failure of sensing and reporting events in the environment. Hence energy conservation has been receiving increased attention in WSN research works. The concept of mobile sink has been recently introduced for WSNs in order to improve the overall performance of WSNs as it shifts the burden of energy consumption from the sensor nodes to sink nodes, which are typically considered to have unconstrained energy supply and larger computational power. In this thesis we present two sink mobility schemes: Load Base sink Movement (LBM) and Residual Energy Aware Routing (REAR) to prolong network lifetime in a random event-driven scenario. LBM computes the optimal tentative sink node position considering both the geographical distance from sensors to sink and transmission load of sensors as well. REAR is a routing strategy that considers the residual energy of sensors when establishing routing paths. Experimental results confirm that the proposed schemes can significantly extend the network lifetime, compared to existing techniques