MDS Coded Cooperative Caching for Heterogeneous Small Cell Networks

Abstract

In this paper, the cooperative caching strategies are developed for a typical cache-enabled small cell network under heterogeneous file and network settings, where the neighboring base stations are enabled to collaborate to share the cached content. To make full usage of the content diversity in the caches, maximum distance separable (MDS) codes are used for content restructuring. The content placement and the cooperation policy among the neighboring base stations are jointly optimized to minimize the {\em long-term average} user attrition (UA) cost for fetching content from external storage subject to the cache capacity constraints. In addition to the unicast based cooperative caching scheme, a compound caching strategy, namely multicast-aware cooperative caching assuming fixed and dynamic cooperative policies, respectively, is developed to combine the merits of multicast-aware content delivery and cooperative content sharing. Mathematical analysis and simulation results are presented to illustrate the advantages of MDS coded cooperative caching strategies in terms of reducing the backhaul requirements.