RAN Revolution With NGFI (xhaul) for 5G

From "Rethinking Ring and Young" in 2011 to proposing next generation fronthaul interface (NGFI, aka xhaul) in 2014, the radio access network (RAN) revolutionary path to meet ambitious 5G demands has been charted out. Traditional fronthaul solutions fell short both in required bandwidth and architecture flexibility. NGFI proposed by China Mobile targeting a packet-based, traffic-dependent, and antenna scale-independent interface will be central to the 5G RAN revolution. This paper presents its latest progress. Specifically, a two-level NGFI architecture will be highlighted, and the function split options with associated requirements in, e.g., latency, bandwidth, and synchronization will be presented. In addition, challenges as well as the potential solutions for NGFI realization will be discussed.