Threshold-Based RRH Switching Scheme Considering Baseband Unit Aggregation for Power Saving in a Cloud Radio Access Network

Abstract

The increase in the volume of mobile data traffic degrades network performance. To improve this situation, a novel network architecture called cloud radio access network (C-RAN) has been introduced. In the existing literature, power saving in C-RAN is implemented in the following two parts: remote radio heads (RRHs) or baseband units (BBUs). However, such power saving schemes do not cooperate with each other, thereby increasing the power consumption of C-RAN. This possibility remains unexplored by researchers in the field. Therefore, in this study, we investigate the tradeoff between the power consumptions of RRHs and BBUs, and propose a novel power saving scheme with RRH switching and BBU aggregation. In the proposed solution, we formulate a theoretical model of BBU aggregation with an RRH traffic threshold to estimate the number of active RRHs and BBUs. Based on the theoretical model, we propose the optimal traffic threshold that minimizes the total power consumption of RRHs and BBUs. Numerical and simulation results reveal that the proposed traffic-threshold-based approach can reduce the total power consumption of C-RAN. Moreover, the results demonstrate that there is a tradeoff between the power consumptions of RRHs and BBUs.