Edge Caching Resource Allocation in Fog Radio Access Networks: An Incentive Mechanism Based Approach

In this paper, an edge caching resource allocation problem in fog radio access networks (F-RANs) is investigated. To motivate content providers (CPs) to participate in this resource allocation procedure, we introduce an incentive mechanism. By treating fog access points (F-APs) as a specific type of edge caching resource, the cloud server sets non-uniform prices of F-APs and leases them to the CPs, while the CPs cache the most popular contents in the storage of F-APs and get rewarded by the raised content hit rate. We formulate the interaction between the cloud server and the CPs as a Stackelberg game and solve the corresponding optimization problems to achieve Nash equilibrium (NE). In particular, by exploiting the multiplier penalty function method, we transform the constrained optimization problem for the cloud server into an equivalent non-constrained optimization problem. Then, we propose an edge caching resource pricing algorithm to solve the non-constrained optimization problem by applying the simplex search method. We also theoretically prove the existence and uniqueness of the NE. Simulation results show the rapid convergence of the proposed algorithm and the superiority performance in improving content hit rate.