BEE-DRONES: Energy-efficient Data Collection on Wake-Up Radio-based Wireless Sensor Networks

Several recent studies demonstrated that the utilization of Unmanned Aerial Vehicles (UAVs) in combination with Wireless Sensor Networks (WSNs) can enhance the system performance in terms of lifetime and data delivery ratio; at the same time, the communication among Wireless Ground Sensors (WGSs) and UAVs poses several technical challenges which are far from being solved. Specifically, in this paper, two main issues are addressed: (i) how to ensure seamless synchronization among ground and aerial devices at each transit, and (ii) how to compute energy-efficient schedules for the WGSs and feasible trajectories for the UAVs. To this purpose, BEE-DRONES, a novel framework for data collection in wake-up radio based UAV-aided WSNs is proposed; in order to solve the synchronization issue, a solution where UAVs transfer energy toward selected WGSs is presented. The solution allows WGSs to power down the main radio when not requested. The joint WGSs wake-up scheduling and UAV path planning optimization problem is formulated, by taking into account the limited autonomy of the UAVs, the energy consumption of both UAVs and WGSs, and the data requirements of the applications, and it is solved via a two-step heuristic. The OMNeT++ simulation results demonstrate that the BEE-DRONES framework is able to enhance the WSN lifetime, and to optimize the quality of gathered data in terms of minimal temporal/spatial correlation.