A Bandwidth Adaptation Scheme for Cloud Radio Access Networks

Abstract

With the advent of Cloud Radio Access Networks (C-RAN) where base band units (BBU) have the ability to dynamically support the bandwidth allocation and centrally manage the bearers transmitted from the remote radio heads (RRH), bandwidth adaptation (BA) mechanism emerges as a promising solution to provide the required resources for C-RAN to provide resources to the bearers during congestion. Existing studies use BA mechanism on congestion management only for LTE system but rarely for C-RAN. To achieve this goal, this paper takes the advantage of dual connectivity with the ability of bearer split to cooperatively provide resources by the serving RRHs, at the same time the mobility robustness and the throughput performance can be improved. The main contribution of this work is to propose an improved BA mechanism for C-RAN with dual connectivity in a centralized concept. More specifically, this work designs a “downgrading index” includes two additional centralized contribution attribute to decide the proportional resource contribution of the bearers which are transmitted by the chosen RRHs and are grouped to assist the serving RRHs. Finally, simulation results illustrate the proposed BA mechanism for C-RAN with dual connectivity significantly reduces the probabilities of the handoff bearer dropping and the bearer blocking.