Resolving Cache-Load Imbalance Bottleneck of Stochastic Shared-Cache Networks

This work proposes a two-layered coded caching scheme to resolve the cache-load imbalance bottleneck of the coded caching in a stochastic shared-cache network where the association between users and shared caches is random, i.e., for the scenario where each user can appear within the coverage area of – and subsequently is assisted by – a specific cache-enabled helper node based on a uniform probability distribution. To insightfully capture the effectiveness of our scheme in mitigating the adverse effect of randomness in shared-cache networks, we derive the exact scaling laws of the average delivery time. In the scenario of an error-free broadcast channel of bounded capacity per unit of time where the delivery involves K users and Λ cache-enabled helper nodes, we show that empowering users with an additional layer of caching can significantly mitigate, and in certain memory regimes completely nullify the adverse effects of the cache-load imbalance bottleneck.