Hierarchical Proactive Caching for Vehicular Ad Hoc Networks

Recently, emerging vehicular applications are increasing the demand of vehicles which form significant burdens on network backhaul and represents a cause to the quality of experience (QoE) decay of the vehicular users. Proactive caching is a promising technique to mitigate the load on core networks by caching some of the expected data items. This work proposes a hierarchical proactive caching scheme which jointly considers caching in vehicles and roadside units (RSUs). Minimization of the vehicle communication latency is the main objective of our study. The optimization problem is formulated to find the optimal caching decision at RSUs and vehicles. Numerical results show that proactive caching has a great performance gain compared to the baseline reactive scenario. Moreover, results reveal that caching in vehicles, with small memory cache size, has effective impact on the total network latency.