An Experimental Study of C-RAN Fronthaul Workload Characteristics: Protocol Choice and Impact on Network Performance

Cloud Radio Access Network (C-RAN) has been proposed as a new paradigm shift in the Radio Access Network (RAN) technology as a part of the fifth generation Long-Term Evolution Advanced (LTE-A) networks to support better spectral and energy efficiency along with the high availability. In this paper, we discuss implementation details of a C-RAN Fronthaul with the help of USRP-based transceivers and LabView platform. To the best of our knowledge, this is the first implementation of a C-RAN architecture that functionally splits the radio resource head (RRH) and the baseband processing unit (BBU) at the physical layer (Split 8) and transfers the completely unprocessed raw signal elements from the RRH to the BBU pool at the cloud for signal processing. We explore TCP and UDP as alternate protocols for fronthaul data transfer to the cloud. In order to evaluate the performance of a C-RAN fronthaul and the interplay of different performance parameters for fronthaul data transfer, we observe various metrics like the receiver goodput and the latency and compare the performance between a C-RAN setup and a generic distributed RAN setup. We observe that TCP works better for Ethernet fronthauling compared to UDP, as it provides reliable data delivery. The analysis discussed in this paper gives insights about the implementation and performance of a C-RAN environment which is essential for designing efficient fronthauling and functional splits of a C-RAN architecture.