Link Scheduling in Wireless Networks With RF Energy Harvesting Nodes
In a wireless network, a scheduler ensures links are given frequent transmission opportunities. A short schedule means links transmit frequently and thus the resulting network capacity is high. In this paper, we consider a novel aim: deriving a link schedule that supports both data and energy links; the latter type of links are used to fulfill the energy requirement of radio frequency energy harvesting (EH) devices. This aim is significant as we envisage future wireless routers to have dual roles: forwarding data and charging devices. To this end, we present a mixed integer linear program to derive the shortest link schedule for both types of links; each with a data rate or energy requirement. We consider transmission power control and the physical interference model. In addition, we present a heuristic algorithm called linear programming approximation algorithm (LPAA) to derive the schedule for large-scale topologies. Our results show that the schedule length is affected by the number of links, energy requirement and energy conversion rate of EH nodes, transmit power, and signal-to-interference-noise ratio threshold. Lastly, our experimental results indicate that LPAA is capable of producing schedules that are near optimal.