Adaptive Delivery in Caching Networks

TL;DR

This paper introduces an adaptive delivery method for caching networks that intelligently switches between uncoded and coded transmissions based on demand redundancy, significantly improving delivery efficiency especially with correlated requests.

Contribution

The paper proposes a novel adaptive delivery scheme that reduces the gap to the lower bound in caching networks with correlated demands, enhancing efficiency over existing methods.

Findings

Adaptive method reduces delivery rate gap by up to 50%.

Performance improves notably with correlated user requests.

Lower bound on delivery rate derived for redundant requests.

Abstract

The problem of content delivery in caching networks is investigated for scenarios where multiple users request identical files. Redundant user demands are likely when the file popularity distribution is highly non-uniform or the user demands are positively correlated. An adaptive method is proposed for the delivery of redundant demands in caching networks. Based on the redundancy pattern in the current demand vector, the proposed method decides between the transmission of uncoded messages or the coded messages of [1] for delivery. Moreover, a lower bound on the delivery rate of redundant requests is derived based on a cutset bound argument. The performance of the adaptive method is investigated through numerical examples of the delivery rate of several specific demand vectors as well as the average delivery rate of a caching network with correlated requests. The adaptive method is shown to considerably reduce the gap between the non-adaptive delivery rate and the lower bound. In some specific cases, using the adaptive method, this gap shrinks by almost 50% for the average rate.