Cluster Content Caching: An Energy-Efficient Approach to Improve Quality of Service in Cloud Radio Access Networks

TL;DR

This paper introduces a cluster content caching structure in cloud radio access networks to reduce power consumption and enhance quality of service by leveraging distributed caching and centralized processing.

Contribution

It proposes a novel cluster content caching architecture and joint resource allocation algorithms to improve energy efficiency and QoS in C-RANs.

Findings

Reduces backhaul traffic and power consumption.

Improves QoS guarantees with lower local storage costs.

Simulation confirms performance gains of the caching approach.

Abstract

In cloud radio access networks (C-RANs), a substantial amount of data must be exchanged in both backhaul and fronthaul links, which causes high power consumption and poor quality of service (QoS) experience for real-time services. To solve this problem, a cluster content caching structure is proposed in this paper, which takes full advantage of distributed caching and centralized signal processing. In particular, redundant traffic on the backhaul can be reduced because the cluster content cache provides a part of required content objects for remote radio heads (RRHs) connected to a common edge cloud. Tractable expressions for both effective capacity and energy efficiency performance are derived, which show that the proposed structure can improve QoS guarantees with a lower power cost of local storage. Furthermore, to fully explore the potential of the proposed cluster content caching structure, the joint design of resource allocation and RRH association is optimized, and two distributed algorithms are accordingly proposed. Simulation results verify the accuracy of the analytical results and show the performance gains achieved by cluster content caching in C-RANs.