Trade-offs in Cache-enabled Mobile Networks

Mobile data traffic demand has been growing at an unprecedented rate in the last few years. Cache-enabled mobile edge computing is known to be one of the most promising techniques to accommodate the traffic demand and alleviate the congestion at the backhaul links. However, due to limited cache capacity at the eNBs, at some parts of the network, congestion of the backhaul links and the radio resources is still possible. Thus, efficient approaches are needed in order to cache content at eNBs as well as to leverage the utilization of the resources in the mobile network while trying to avoid their congestion.In this paper, we study the trade-offs between the radio resource utilization and the backhaul link utilization in cache-enabled mobile networks. Initially, we show the trade-offs by formulating a mobility-aware joint content caching, user association, and resource allocation problem as an Integer Linear Programming problem and proposing a greedy heuristic to solve the large instances of the problem. We then propose an approach to compute radio resource and backhaul link costs, and by using the costs, we formulate a joint user association and resource allocation problem aiming at preventing network congestion, assuming that the cached content is given. The results reveal that around 10% more users get an association to the network by using the proposed algorithm.