Energy neutral directed diffusion for energy harvesting wireless sensor networks

In recent years, energy harvesting techniques have been used to mitigate the problem of the energy resource limitation in traditional Wireless Sensor Networks. In particular, it is now possible for a sensor with energy harvesting capabilities to operate perpetually in an Energy Neutral state, which can be achieved by making sure that the harvested energy will be able to replenish the energy that is being consumed. In this paper, we propose a query driven Energy Neutral Directed Diffusion (ENDD) protocol that aims at maintaining the network level energy neutral state, which in turn provides consistent data delivery and unlimited network lifetime. Traffic flow admission controls are carried out locally at each sensor based on their own energy harvesting status, which prevent sensors from shutting down due to excessive usage of energy. We also propose a real-time realistic energy consumption estimation model to improve the reliability of the admission control process. Furthermore, we analytically show that ENDD is highly scalable as it is able to guarantee a linear upper bound on the total number of communication control messages exchanged for route establishment. Extensive simulations are also carried out to evaluate and compare the performance of our proposed ENDD protocol against other query driven routing protocols.