Test Plans, Results, and Lessons Learned About Open RAN Integration
Abstract: The vision of the 5G Challenge competitions was to accelerate adoption of 5G open interfaces, interoperable subsystems, and multi-vendor solutions by fostering a large, vibrant, and growing vendor community dedicated to advancing 5G interoperability towards true plug-and-play operation. This report provides test plans, results, and lessons learned about 5G Open RAN multi-vendor interoperability and compliance during the 2022 and 2023 5G Challenges. Multiple vendors demonstrated O-RAN ALLIANCE subsystem interoperability and performance on a limited timeline with no prior integration or planning. Contestants made significantly faster integration progress when they were open to sharing and working together. Significant integration time was devoted to resolving configuration parameters and compliance mismatches (e.g., which options were selected). Stringently following software development best practices improves the speed and success of multi-vendor interoperability.
The National Telecommunications and Information Administration’s Institute for Telecommunication Sciences (NTIA/ITS) and the U.S. Department of Defense’s Office of the Under Secretary of Defense for Research and Engineering (OUSD(R&E)) partnered to execute prize-based 5G Challenge competitions to foster, accelerate, and expand Open RAN development and adoption. This included a key partnership with CableLabs as the host lab and system integrator to develop and execute the test strategy and activities. This report presents the methodology and results from this research to expand and improve Open RAN interoperability testing and thereby accelerate the adoption and development of Open RAN services. The 5G Challenges implemented an innovative multi-vendor interoperability testing paradigm for fifth generation (5G) cellular open radio access network (Open RAN) standards- based systems. This novel testing approach allowed true ad hoc multi-vendor interoperability testing to encourage new development and entrants into the 5G Open RAN marketplace. The research provides insights and recommendations for future activities that replicate and build on the 5G Challenge’s testing framework to further support multi-vendor deployments of O RAN ALLIANCE open central units (O-CU), open distributed units (O-DU) and open radio units (O-RU). The O-CU hosts the control plane and user plane functions and protocols that control radio resources, packet data convergence, and transport layer processing. The O-DU hosts various protocol layers for base band processing and data transmission. The O- RU converts the radio signals from the antenna to digital signals sent to the O-DU and vice versa.