Living on the edge: The role of proactive caching in 5G wireless networks

TLDR

Proactive caching, enabled by predictive capabilities, storage advances, context awareness, and social networks, is a key enabler of beyond‑4G small‑cell networks that can substantially reduce peak traffic demands by serving predictable user demands at base stations and devices. The study aims to demonstrate the effectiveness of proactive caching through two case studies that exploit spatial and social network structures. The authors propose a two‑step mechanism: first, files are proactively cached during off‑peak periods based on popularity and user‑file pattern correlations to alleviate backhaul congestion; second, they predict influential users in social networks to cache strategic content and disseminate it via D2D communications. Numerical results show that proactive caching yields backhaul savings and a higher satisfied‑user ratio of up to 22 % and 26 %, respectively, with further gains achievable by increasing edge storage capacity.

Abstract

This article explores one of the key enablers of beyond 4G wireless networks leveraging small cell network deployments, proactive caching. Endowed with predictive capabilities and harnessing recent developments in storage, context awareness, and social networks, peak traffic demands can be substantially reduced by proactively serving predictable user demands via caching at base stations and users' devices. In order to show the effectiveness of proactive caching, we examine two case studies that exploit the spatial and social structure of the network, where proactive caching plays a crucial role. First, in order to alleviate backhaul congestion, we propose a mechanism whereby files are proactively cached during off-peak periods based on file popularity and correlations among user and file patterns. Second, leveraging social networks and D2D communications, we propose a procedure that exploits the social structure of the network by predicting the set of influential users to (proactively) cache strategic contents and disseminate them to their social ties via D2D communications. Exploiting this proactive caching paradigm, numerical results show that important gains can be obtained for each case study, with backhaul savings and a higher ratio of satisfied users of up to 22 and 26 percent, respectively. Higher gains can be further obtained by increasing the storage capability at the network edge.