Online Caching in Heterogeneous Networks

In this paper we propose a novel online caching method to perform the update phase in a distributed caching system, with a natural application to heterogeneous scenarios with cache-equipped small-cell base stations. We investigate the performance of our scheme, showing in particular that it results in a significant reduction of backhaul load, to the point of converging to the performance of the optimal offline placement scheme. While the optimal scheme is obtained at a high complexity cost, the performance of our solution is achieved in a low-complexity decentralized manner. Numerical simulations confirm that the novel online scheme adapts efficiently to varying networks parameters such as the file popularities, without the need of the usually time-consuming learning phase, which makes the proposal adapted for low-latency caching applications.