An Energy-efficient Hierarchical Protocol for Wireless Powered Sensor Networks

In this paper, a new hierarchical protocol has been proposed for the emerging wireless powered sensor network (WPSN) in which a centralized hybrid sink node (HSN) firstly supplies the sensor nodes (SN) with stable power wirelessly, and then it aggregates packets of sensed data through multiple hops for energy saving. In WPSN, the performance of packet aggregation will be dramatically influenced by severe Doubly Near-Far Effect, thus some SNs located far from HSN require much more energy to send packets but only can harvest little energy. So in our model, from the perspective of energy saving, the network is proposed to be divided into several layers. In order to obtain the exact border of each layer, the energy broadcasted by HSN and the radius of each layer are optimized. Numerical results are provided to demonstrate the proposed solutions. Our proposed protocol outperforms the typical protocols of WSN and the star network topology in the same condition.