Coded caching in hybrid networks

Abstract

Content caching is an efficient technique to reduce delivery latency and system congestion during peak-traffic times by bringing data closer to end users. Existing works on caching usually assume symmetric networks with identical user requests distribution, which might be in contrast to practical scenarios where the number of users is usually arbitrary. In this paper, we investigate a cache-assisted heterogeneous network in which edge nodes or base stations (BSs) are capable of storing content data in their local cache. We consider general practical scenarios where each edge node is serving an arbitrary number of users. First, we derive an optimal storage allocation over the BSs to minimize the shared backhaul throughput for a uncoded caching policy. Second, a novel coded caching strategy is proposed to further reduce the shared backhaul's load. Finally, the effectiveness of our proposed caching strategy is demonstrated via numerical results.