Joint Content Caching and Delivery Policy for Heterogeneous Cellular Networks

Caching the popular contents near users is an effective way to release the burden of the wireless networks and reduce the energy consumption of content service for delivery. In this paper, we consider a distributed way to cache content with different user preference in heterogeneous cellular networks (HetNets). Aiming at minimizing the energy consumption of the whole network, a joint content cache and delivery optimization problem is proposed. Considering the coupling multiplicative variables, we utilize the alternative optimization (AO) algorithm to decompose the original problem into the content cache and delivery problems, which are solved separately through the knapsack solution and message passing (MP) algorithm. Numerical results reveal that the proposed scheme achieves more in energy saving than conventional schemes.