Low Latency Caching Placement Policy for Cloud-Based VANET with Both Vehicle Caches and RSU Caches

In the vehicular ad hoc networks (VANETs), caching is a very promising technique to mitigate the transmission burden and to improve consumers' Quality of Experience (QoE) in terms of latency. Determining caching placement policy is one of the most important issues to maximize the caching gain. In this paper, based on the cloud-based VANET architecture and the corresponding content retrieve process, a caching placement policy which jointly considers the caching at the vehicular layer and roadside unit (RSU) layer is proposed. More specifically, the caching placement problem is modeled as an optimization problem to minimize the average latency while satisfying the QoE requirements of vehicles, and the problem is solved effectively via convex optimization and Stimulated Anneal (SA) methods. Simulation results indicate that the proposed scheme performs better than the existing caching schemes.