OVERCOMING ENERGY EFFICIENCY CHALLENGES IN C-RAN: A REVIEW OF RECENT ADVANCES AND SOLUTIONS

Abstract

Cloud Radio Access Networks (C-RAN) represent a modern shift in cellular network architecture by centralizing baseband processing units (BBUs) in cloud data centers while deploying distributed remote radio heads (RRHs) at cell sites. Although C-RAN offers improved scalability, flexibility, and centralized network management, it also introduces significant energy efficiency challenges due to high power consumption in BBU pools, multiple active RRHs, and substantial cooling demands in central facilities. This paper reviews key energy efficiency challenges in C-RAN, particularly under dynamic traffic loads and idle power scenarios. It also explores recent advancements such as dynamic BBU pooling, RRH sleep mode techniques, AI-based traffic prediction, and the integration of renewable energy sources. Findings suggest that substantial energy savings can be achieved without compromising network performance by deploying these strategies across different layers of the network. The paper concludes with future research directions aimed at enhancing C-RAN energy efficiency in the context of evolving 5G and beyond-5G networks.