Edinburgh Napier University

  The issue of energy holes, or hotspots, in wireless sensor networks is well referenced. As is the proposed mobilisa-tion of the sink node in order to combat this. However, as the sink node shall still pass some nodes more closely and frequently than others, issues remain, such as energy spikes. In this study we propose a lightweight MAC layer solution-Mobility Aware Duty Cycling and Dynamic Preambling Algorithm (MADCaDPAL). Building on existing solutions utilising a communication threshold between static nodes and a sink node using a predictable mobility pattern, this algorithm bases decisions relating to node wake-up schedules, clear channel assessment and the sending of preambles on the mobile sink position in relation to the threshold built by the static node. When tested on a lightweight carrier-sense multiple access based MAC implementation, we show a reduction in average energy consumption up to 80% and a significant reduction in energy spikes in individual nodes. This as well as maintaining or improving levels of frame delivery to the sink. Thus, significantly improving network lifetime.