Closer destination selection scheme for mobile sink and charger enabled WRSNs

In WRSNs (Wireless Rechargeable Sensor Networks), the wireless energy transfer technology enables charging sensor batteries and maintaining perpetual operation of the network. The MC (mobile charger) is able to provide stable and reliable energy supply for sensor nodes. Although many researchers study the efficient scheduling of the MC, none of them considers the situation where both the static sink and the MC can collect packets. In this case, each sensor node should choose the appropriate destination, i.e., the static sink or the MC. In this paper, we propose closer destination selection scheme for mobile sink and charger enabled WRSNs where a static sink and an MC coexist. In order for each sensor node to send packets to the closer destination, i.e., the static sink or the MC, when an MC tours to charge sensor nodes, it constructs another temporal tree-based topology network by sending a route construction packet to sensor nodes within the limited area. Whenever the MC stays at a sensor node, it calculates the maximum number of hops that sensor nodes should switch to a temporal network. This temporal network that the MC creates does not disturb the original network. By constructing a temporal network, an MC relaxes the load of sensor nodes around the static sink without unnecessary path extension. We evaluate the performance of our scheme through the computer simulation. Results indicate that our scheme improves the packet arrival rate and energy efficiency compared to the conventional scheme.