European Open RAN MoU Group Release 4 Published

The Open RAN MoU Group, composed of leading European telecom operators Deutsche Telekom, Orange, Telefónica, TIM, and Vodafone, have published the fourth release of their technical priorities document. The MoU, signed in January 2021, aims to accelerate the development of Open RAN solutions and avoid fragmentation by providing the vendor community with a set of technical priorities all five operators broadly agree on. Hardware and software manufacturers can use these to guide their R&D efforts and technology roadmaps.

The release also feeds into the work carried by organisations like the O-RAN ALLIANCE and the Telecom Infra Project. This helps ensure open interfaces are standardised and products, solutions, and systems can be tested and validated. The process is designed to “promote a fast pace for the development of competitive Open RAN solutions in Europe, across other regions and ultimately accelerate the global adoption of the technology” according to the MoU statement.

Release 4 provides “guidance to the RAN supplier industry on where they can focus to accelerate market deployments in Europe, focusing on commercial product availability in the short term, and solution development in the medium term” by providing updates on

• Developing further requirements on Service Management Orchestration (SMO) especially related to AI/ML framework, interworking with traditional RAN and slicing management, as well as security
• Cloud infrastructure mainly focused on O2 and Acceleration Abstraction Layer
• A new dedicated section on hardware acceleration
• Enhancements to previous releases such as RAN software, O-RU and O-CU/DU

The priorities highlight some of the points of contention that have arisen in Open RAN over the past year. These include how to accelerate the standardisation of interfaces like the O2 interface and the role hardware accelerators should play in managing and optimising the RAN via the non real time and near real time RICs (the famous in-line Vs look-aside debate).

Resolving these questions is important to the future development of a fully open SMO, a key component of Open RAN networks. Indeed, the SMO can help operators reduce the TCO of building and managing complex multi-vendor 5G networks by replacing manual processes with intelligent automation.

The document warns however that the priorities “will evolve over time following the progress of O-RAN ALLIANCE standardisation, in the respective standardisation bodies, and market development of Open RAN solutions”. The last point in particular seems important. 

Indeed, one of the main criticisms levelled at service providers championing Open RAN today is the lack of vendor diversity in existing commercial deployments. Given the resources and levels of investment needed to develop RAN solutions in the first place (for example, it’s taken Mavenir at least $830 million in funding to get to this stage), it feels like a lot of hoops to jump through for as yet little guarantee of success. This is obviously an area the Open RAN community absolutely has to improve on.

The issue with today’s Open RAN deployments is they require vendor proprietary extensions to enable this intelligent automation, whether in the SMO itself or in the RIC (both near real time and non near real time), according to a white paper jointly published last summer by NTT DOCOMO and Vodafone. The authors suggest that overcoming this issue will go a long way to fulfilling Open RAN’s promise of enabling a true multi-vendor deployment (hat tip to Iain Morris from Light Reading for the white paper).