Mobility and energy aware data routing for UAV-assisted VANETs

In this paper, we develop a mobility and energy aware data routing protocol for unmanned aerial vehicle-assisted vehicular ad-hoc networks (UAV-assisted VANETs). One of the UAV act as a flying roadside Uunit (RSU) collecting data from ground vehicles, while the other UAVs play the role of relays to deliver the data to mobility service center (MSC). The UAVs can adjust their three-dimensional (3D) locations within a predefined range, if needed, in order to ensure reliable communication links. The proposed approach aims to minimize the energy consumed by the UAVs in both data transfer and movement. which ensures fair distribution of the routing effort across the different UAVs in the network. This is achieved by taking the residual UAV energy into account in the routing decision. We formulate such a routing problem as a mixed integer non-linear program (MINLP) to determine both the selected route and the locations of the UAVs participating in the data transfer process. Since such a problem is non-convex, we proceed with a joint optimization solution where the route is optimized using an ILP and the UAVs' 3D locations are determined using the meta-heuristic particle swarm optimization (PSO) algorithm. We present a selected set of numerical results to illustrate the performance of the proposed solution for different scenarios and compare it to a meta-heuristic approach based on swarm intelligence.