摘要

The key technologies involved in the evolution of the Cloud-based Radio Access Network (C-RAN) are discussed in this paper. Taking the Frameless Network Architecture (FNA) as a starting point, a cell-less-based network topology for a multi-tier Heterogeneous Network (HetNet) and ultra-dense network is proposed. The FNA network topology modeling is researched with centralized processing and distributed antenna deployments. The Antenna Element (AE) is released as a new dimensional radio resource that is included in the centralized Radio Resource Management (RRM) processes. This contributes to the on-demand user-centric serving-set associations with cell-edge effect elimination. The Control Plane (CP) and User Plane (UP) separation and adaptation are introduced for energy efficiency improvements. The centralized RRM and different optimization goals are discussed for fully exploring the merits from the centralized computing of C-RAN. Considering the complexity, near-optimal approaches for specific users' Quality-of-Service (QoS) requirements are addressed. Finally, based on the research highlighted above, the way forward of C-RAN evolution is discussed.