At the recent i14y Lab Open RAN services and platforms PlugFest, which was part of the O-RAN ALLIANCE Global PlugFest Fall 2022, Rohde & Schwarz and VIAVI Solutions have combined their industry-leading capabilities to deliver an integrated solution for conformance testing of O-RAN Radio Units (O-RUs). With the automated testing solution, they were able to verify Analog Devices’ innovative 8T8R O-RU reference design and development kit according to both O-RAN and 3GPP pre-conformance.

The Joint European O-RAN and TIP PlugFest Fall 2022 was organized by i14y Lab, an industry consortium aiming at accelerating network disaggregation and Open RAN by building a European and German ecosystem of vendors and system integrators. It is supported by Deutsche Telekom and European Advanced Network Test Center (EANTC). Technology vendors like Analog Devices, Inc. had the opportunity to verify the conformance of their platforms with test and measurement (T&M) solutions from Rohde & Schwarz and VIAVI Solutions amongst others.

One successful scenario was the automated verification of an O-RAN Radio Unit (O-RU). Network disaggregation brings new challenges because it requires interoperability between network equipment from different vendors. The evolving O-RUs need to conform with both 3GPP and O-RAN standards. Fronthaul conformance tests, defined by the O-RAN ALLIANCE, ensure that the emerging O-RU designs are interoperable with the O-RAN distributed unit (O-DU).

To address multiple application scenarios, Analog Devices has developed a particularly flexible O-RU reference design. The ADRV904x-RD-RUMB 8T8R O-RU reference design and development kit supports time division duplex (TDD) as well as frequency division duplex (FDD) modes and multiple bands including all FR1 frequencies from 600 MHz up to 6 GHz, as well as it includes a complete O-RAN RU Split 7.2 x split for 4G & 5G NR standards.

Rohde & Schwarz and VIAVI Solutions are both leaders 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 that has been used to support several Open Testing and Integration Centres (OTICs), and was used at the O-RAN PlugFest for validating Analog Devices’ O-RU reference design:

• The R&S®SMM100A vector signal generator, R&S®FSVA3000 signal and spectrum analyzer as well as the R&S®VSE vector signal explorer analysis software from Rohde & Schwarz have emulated a real-world radio environment by generating, capturing and analyzing RF signals, extended for O-RAN applications.
• 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 user experience throughout the test setup.

At i14y Lab Open RAN PlugFest, this test platform verified Analog Devices’ O-RU reference design according to the O-RAN conformance test specifications defined by the open fronthaul interfaces workgroup WG4. This includes the control and user plane (CU-Plane) for both FDD and TDD modes of operation. In addition, the setup supported test cases from 3GPP TS 38.141-1 Base Stations (BS) conducted conformance transmitter testing.

With a wide portfolio ranging from mobile network infrastructure equipment verification through conformance to mobile network testing and benchmarking, Rohde & Schwarz helps to drive development, deployment and operation of Open RAN networks.

Alexander Pabst, Vice President of Market Segment Wireless Communications at Rohde & Schwarz, says: “Open RAN innovators like Analog Devices need powerful O-RU test solutions to verify the smooth interworking of their designs in a disaggregated multi-vendor network. The i14y Lab in Berlin is a fruitful collaboration space for testing, harmonizing and validating Open RAN solutions. We are proud to be a consortium partner of i14y Lab. Together with their partners they are providing more flexibility, innovation, and choice for all Open RAN industry players.”

Joe Barry, Vice President of Wireless Communications at Analog Devices, says: “By pre-testing Analog Devices’ O-RU reference design platforms for interoperability and O-RAN conformance standards using the Rohde & Schwarz and VIAVI test setup, our customers can accelerate their integration efforts with confidence. This will help to reduce design cycles and significantly improve time to market.”

Stephen Hire, Vice President of Wireless Marketing at VIAVI, says: “Open RAN technology has already proven itself in greenfield deployments, but to achieve mainstream breakthroughs it will need to demonstrate the flexibility to accommodate a wide range of spectrum allocations and different mixes of 4G and 5G. Flexible designs such as the new O-RU from Analog Devices help deliver on this. These more flexible designs require far more test permutations. We are pleased to have partnered with Rohde & Schwarz and supported Analog Devices and i14y to demonstrate how our automated platform can help customers efficiently prove conformance to 3GPP and O-RAN ALLIANCE specifications.”

For more information on O-RAN testing solutions from Rohde & Schwarz, visit: Testing O-RAN