Phase and Time Synchronization for 5G C-RAN: Requirements, Design Challenges and Recent Advances in Standardization

Abstract

Cloud-RAN is one of the key enablers for 5G. In this paper we present the importance of network synchronization for the fronthaul architectures. The term network synchronization refers to the distribution of time and frequency among spatially distributed remote nodes. Underlining this point, we investigate the requirements and network design challenges to precisely synchronize the 5G C-RAN radio units. We conclude the article by pointing-out the recent advances in standardization together with describing the proposed practical solutions and methodologies to practically overcome these challenges in real networks.