RadioAccessNetworks(C-RANs)方案.PDFVIP

Cooperative Hierarchical Caching in 5G Cloud Radio Access Networks (C-RANs) Tuyen X. Tran, Student Member, IEEE, Abolfazl Hajisami, Student Member, IEEE, and Dario Pompili, Senior Member, IEEE Abstract—Over the last few years, Cloud Radio Access Net- work (C-RAN) is proposed as a transformative architecture for 7 5G cellular networks that brings the flexibility and agility of cloud Internet 1 computing to wireless communications. At the same time, content 0 caching in wireless networks has become an essential solution to RRH 2 lower the content-access latency and backhaul traffic loading, r leading into user Quality of Experience (QoE) improvement Backhaul CPRI p and network cost reduction. In this article, a novel Cooperative A Hierarchical Caching (CHC) framework in C-RAN is introduced BBU where contents are jointly cached at the BaseBand Unit (BBU) EPC RRH 8 and at the Radio Remote Heads (RRHs). Unlike in traditional approaches, the cache at the BBU, cloud cache, presents a ] new layer in the cache hierarchy, bridging the latency/capacity T gap between the traditional edge-based and core-based caching RRH I . schemes. Trace-driven simulations reveal that CHC yields up to s 51% improvement in cache hit ratio, 11% decrease in average c content-access latency, and 18% reduction in backhaul traffic Fig. 1. C-RAN architecture