Mobile Unmanned Aerial Vehicles (UAVs) for Energy-Efficient Internet of Things Communications

摘要

In this paper, the efficient deployment and mobility of multiple unmannedaerial vehicles (UAVs), used as aerial base stations to collect data fromground Internet of Things (IoT) devices, is investigated. In particular, toenable reliable uplink communications for IoT devices with a minimum totaltransmit power, a novel framework is proposed for jointly optimizing thethree-dimensional (3D) placement and mobility of the UAVs, device-UAVassociation, and uplink power control. First, given the locations of active IoTdevices at each time instant, the optimal UAVs' locations and associations aredetermined. Next, to dynamically serve the IoT devices in a time-varyingnetwork, the optimal mobility patterns of the UAVs are analyzed. To this end,based on the activation process of the IoT devices, the time instances at whichthe UAVs must update their locations are derived. Moreover, the optimal 3Dtrajectory of each UAV is obtained in a way that the total energy used for themobility of the UAVs is minimized while serving the IoT devices. Simulationresults show that, using the proposed approach, the total transmit power of theIoT devices is reduced by 45% compared to a case in which stationary aerialbase stations are deployed. In addition, the proposed approach can yield amaximum of 28% enhanced system reliability compared to the stationary case. Theresults also reveal an inherent tradeoff between the number of update times,the mobility of the UAVs, and the transmit power of the IoT devices. Inessence, a higher number of updates can lead to lower transmit powers for theIoT devices at the cost of an increased mobility for the UAVs.