Performance Analysis of Transport Protocols and RLC modes in 5G Open RAN Networks

Open Radio Access Network (O-RAN) is crucial to the development of the 6th Generation (6G) as it enables an open and disaggregated architecture, fostering innovation, interoperability, and cost reduction—key elements for the efficient development and deployment of next-generation networks. This paper investigates the impact of Acknowledged Mode (AM) and Unacknowledged Mode (UM) Radio Link Control (RLC) modes on the performance of Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) transport protocols in wireless communication networks using the O-RAN architecture. Through tests conducted on a testbed composed of commercial equipment, it is observed that the UM mode achieves the highest throughput levels for the considered transport protocols, with gains of up to 20%. Furthermore, tests using TCP transport protocol show a direct relation between the achieved throughput and the Congestion Window (CWND) size. Thus, it is observed that the RLC UM mode outperforms the RLC AM for the considered Reference Signal Received Power (RSRP) conditions, with gains of up to 18%.