Graph-Theoretic Approach for Cache Placement and Delay Optimization in Cache-Enabled Mobile Networks

Caching at base stations (BSs) is a promising scheme to alleviate the traffic burden in mobile communication systems. In this paper, we aim to minimize the average delay of all users in the cache-enabled mobile network where the BSs can exchange data with each other via X2 interface. We jointly consider cache placement and user association problems and employ graph theory to deal with the optimization task. For a given network graph, we aim to lind the maximum cliques and place different tiles in the maximum clique so as to improve local cache hit probability. In the user association procedure, we make the BSs which store the requested files of users serve these users as many as possible. Simulation results show that our proposed algorithm yields the lowest delay among the other representative algorithms.