Efficient Data Dissemination Strategy for UAV in UAV-Assisted VANETs

With development of emerging intelligent transportation systems (ITSs), unmanned aerial vehicles (UVAs) are gaining growing attention to achieve UAV-assisted VANETs for improving performance of data dissemination. However, in UAV-assisted VANETs, the performance of data dissemination can be significantly compromised by the limited bandwidth resource of UAVs. In this paper, we propose a scheduling strategy to provide efficient data dissemination. In particular, first, we take into account a scenario with either unavailable or overloaded infrastructure, where a UAV is employed to provide data dissemination. Furthermore, considering the limited bandwidth resource of the UAV, we formulate a coding-based cooperative caching data dissemination (C3D2) problem which makes use of the cooperative effect between network coding and vehicular caching with the objective of maximizing the bandwidth efficiency of UAVs. Meanwhile, the NP-hardness of the C3D2 problem is proved by constructing a polynomial time reduction from the simultaneous matrix completion problem. Based on the effectiveness of the binary particle swarm optimization (BPSO) framework in solving the complex problems, we propose a BPSO-based cooperative caching scheduling (BPSO_C2S) algorithm consisting of a series of strategies, such as particle representation, particle evaluation, particle update and infeasible solution amendment. In addition, we analyze the computational complexity of the BPSO_C2S. Finally, we build the simulation model and give a comprehensive performance evaluation through the real-world map and taxi trajectories. Simulation results demonstrate the effectiveness and superiority of the proposed solution.