Content Delivery Analysis in Cellular Networks With Aerial Caching and mmWAVE Backhaul
Wei Wang, Nan Cheng, Yiliang Liu, Haibo Zhou, Xiaodong Lin, Xuemin Shen
Abstract
In this paper, we investigate the successful content delivery (SCD) performance in the unmanned aerial vehicle (UAV) integrated terrestrial cellular networks, where the caching-enabled UAVs are dispatched to offload the burst traffic from the cellular networks. Specifically, the UAV and terrestrial cellular network share the same spectrum resources for user downlink communications and each UAV uses millimeter wave (mmWave) communications for self-backhaul. We derive a closed-form expression of the achievable rate of the mmWave wireless backhaul link and then analyze the minimum cache hit probability to achieve a certain backhaul rate requirement. By approximating the general probabilistic line-of-sight (LoS) propagation model as a LoS ball model, we analyze the conditional SCD probabilities by leveraging stochastic geometry tools. Simulation results demonstrate that the UAV integrated cellular network can not only provide more access opportunities but also achieve higher SCD performance than the conventional terrestrial network for ground users. Moreover, there exists an optimal UAV density and height to maximize the SCD performance. Our results provide useful guidelines for the design and deployment of future UAV-assisted networks.