At the recent O-RAN ALLIANCE Global PlugFest Fall 2023 at the Japan Open Testing and Integration Center (OTIC) hosted by Rakuten Mobile, Rohde & Schwarz and VIAVI Solutions presented their integrated solution for automated conformance testing of O-RAN radio units (O-RUs). With their joint test solution, which combines both companies’ industry-leading capabilities, they performed the automated verification of a commercial O-RU provided by NEC according to both O-RAN and 3GPP pre-conformance specifications.

O-RUs need to conform with both 3GPP standards and O-RAN ALLIANCE specifications. Fronthaul conformance tests as defined by the O-RAN ALLIANCE verify the proper behavior of fronthaul interfaces and ensure that the O-RU designs are interoperable with the O-RAN distributed unit (O-DU). Rohde & Schwarz and VIAVI Solutions are both leading in wireless communication testing and active in specifications development in the O-RAN ALLIANCE and 3GPP. Together they have developed an O-RAN conformance test solution supporting several Open Testing and Integration Centers.

O-RAN ALLIANCE Global PlugFests are periodic events organized and co-sponsored by O-RAN ALLIANCE to enable efficient progress of the O-RAN ecosystem through well-organized testing and integration. Vendors and providers come together to test, evaluate and verify their products and solutions. The O-RAN ALLIANCE Global PlugFest Fall 2023 was held in 16 labs across eight countries. Performing O-RU conformance tests in an automated setup was one of the focus areas at the Japan O-RAN PlugFest Fall 2023, hosted by Rakuten Mobile and held at the Rakuten Cloud Innovation Lab in Yokosuka Research Park, one of the Japan OTIC labs. There, O-RU vendors like NEC had the opportunity to verify the conformance of their platforms with test and measurement solutions from Rohde & Schwarz and VIAVI Solutions among others.

The setup used at the O-RAN PlugFest in Japan to validate NEC’s O-RU consisted of the following test solutions:

• The R&S SMM100A vector signal generator and R&S FSVA3000 signal and spectrum analyzer from Rohde & Schwarz emulated a real-world radio environment by generating, capturing and analyzing RF signals. For in-depth debugging R&S VSE vector signal explorer analysis software was used allowing to access detailed measurement results.
• The TM500 O-RU Tester from VIAVI Solutions has implemented the O-DU side of the M-plane and C/U-plane functionality which was necessary for the configuration of the interface with the O-RU and to exchange I/Q data over the Open Fronthaul.
• The O-RU Test Manager application from VIAVI has provided a single point of control for the integrated system and has ensured a seamless, fully automated user experience throughout the test setup.
• With this setup, automated conformance tests per specification O-RAN.WG4 CONF.0-v09.00 was performed. Additionally, the operation of Open Fronthaul (O-FH) control plane (C-plane), user plane (U-Plane), synchronization plane (S-plane) and management plane (M-Plane) was verified. The setup also supported test cases from 3GPP TS 38.141-1 for base station conducted conformance transceiver testing.

Rohde & Schwarz helps to drive development, deployment and operation of Open RAN networks with its wide portfolio ranging from mobile network infrastructure equipment verification through conformance to mobile network testing and benchmarking. Alexander Pabst, vice president of market segment wireless communications at Rohde & Schwarz, said,  “Large Open RAN deployments are currently planned in various regions around the globe, and a smooth system integration and testing is the key for successful network deployments. Open RAN pioneers like NEC require fully automated O-RU test solutions to overcome the challenge of increasing testing times. While automation used to be a welcome tool to save costs and testing time, for Open RAN it is fundamental. At the Japan O-RAN Plugfest our fully automated integrated solution combining Rohde & Schwarz and VIAVI expertise proved to make testing easier. The integration was based on our great, long-lasting collaboration. And the results can be applied to enhance O-RU robustness.”

Stephen Hire, vice president of wireless marketing at VIAVI, said, “Thorough interoperability, conformance and performance testing are vital to the success of O-RAN but it is also important that testing is conducted efficiently and in the shortest possible time. Automation of the testing helps to meet these objectives and we are pleased to have worked with NEC and Rohde & Schwarz to automate radio testing using the TM500 O-RU Test solution to help NEC meet their test and efficiency objectives.”