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6 September 2022

O-RAN Alliance progresses certification, but maturity is still some way off

By Luc Braun

Standardization and certification for Open RAN has lagged behind technical developments as well as early deployments, which has led to some major operators creating their own ecosystems to ensure interoperability, notable examples being Japan’s Rakuten and Dish Network in the USA. Such a lag is typical of many fields, and can lead to de-facto standards taking hold, with Rakuten already enjoying some success through commercialization of its platform.

Standardization is now playing catch-up with field deployments and proceeding in parallel with new projects. A key step came in June 2022 when the O-RAN Alliance announced its Certification and Badging (C&B) project, with the aim of providing facilities around the world where 5G Open RAN equipment can be tested for conformity to the Alliance’s specifications.

A certificate or badge should guarantee the equipment’s adherence to O-RAN standards and suitability for deployment in multivendor Open RAN networks. An accompanying catalogue of issued certificates and badges available on the Open RAN Alliance’s website can then be used by network operators to help them select appropriate devices for their own networks.

The testing can be done at seven Alliance-approved labs, called Open Testing and Integration Centres (OTICs). Testing is undertaken to verify conformance of the device to Alliance technical specifications, interoperability with other devices, and finally validity of an end-to-end (E2E) Open RAN system with this equipment. Certificates are issued for conformance to technical specifications, while two separate badges are issued for Interoperability and E2E validity.

In Europe, several major MNOs – Telecom Italia for OTIC Torino, Orange for OTIC Paris, and Telefónica for OTIC Madrid – have set up Open RAN testing and security labs that have gained OTIC status. OTIC Berlin is hosted by Deutsche Telekom but operated in cooperation with industry partners, notably Nokia, Telefónica Deutschland and Vodafone Deutschland.

Three more OTICs are spread across the world. Kyrio OTIC, hosted by CableLabs, a research and development laboratory with a multitude of member organizations around the world, is the sole US OTIC to date.

So far, only two certificates have been issued, but the two Asian OTICs in China and Taiwan. The Asia & Pacific OTIC in mainland China certified MICAS RF open radio unit (O-RU) for conformance to the Alliance’s WG4 Open Fronthaul (OFH) specifications. The Auray OTIC and Security Lab in Taiwan certified a Foxconn O-RU, also for adherence to WG4 OFH specifications. Foxconn’s certificate issue saw testing conducted as part of O-RAN’s Global PlugFest in spring 2022. The WG4 OFH certificate saw testing performed in 31 different test cases.

Major electronic test and measurement firms have naturally played major roles in development of Open RAN certification. Among those is Keysight Technologies, a primary editor of the O-RAN WG4 Open Fronthaul interface specifications and member of the O-RAN Alliance’s C&B program. Perhaps unsurprisingly, the company was, through its Keysight Open RAN (KORA) Network Architect solutions, in a prime position to provide assistance for the certification tests for a standard it helped develop and define in the first place. As Keysight indicated, the challenge now is for itself and similar service providers to support the Open RAN equipment and network testing community meaningfully.

There are some serious questions to be addressed, however. As outlined above, since the program and partner OTICs were announced at the end of June, there have been only two certificates awarded as of late August 2022. Outside plugfest events the program seems to not have made an impact with the global Open RAN community as yet.

There are several reasons for this. For one, it seems the announcement of the program by the O-RAN Alliance was premature, or it should be understood perhaps more accurately as a statement of intent. Few OTICs are ready to proceed with testing and certification at this stage and are primarily occupied with preparatory work around both the testing process and equipment, but also the surrounding administrative processes.

The goal here will be to have an automated end-to-end testing set-up with a minimum of human labour involvement beyond maintenance or optimisation, allowing for continuous testing. For now, preparatory work is expected to be complete in a few weeks to months, with dry runs for certain certificates being underway already. The MICAS RF and Foxconn certificate tests were conducted manually and are not an indication of a fully operational system.

A large number of certificates and badges requires a wide range of different testing equipment and environments. Furthermore, the different technical specifications are at different stages of maturity, with some still subject to revision in future releases. Both of these pose significant challenges to the OTICs. For one, they have to cooperate and coordinate with each other on their certificate and badge offerings.

Even at later stages, individual OTICs will not be able to offer the full range of certificates and badges and there are, at least among European OTICs, concrete plans to coordinate with the others to create a system of cooperating and specialized testing facilities. How this will play out for the Asian and American OTICs is not known, but the O-RAN Alliance will certainly have to ramp up investment in testing facilities, either by creating more OTICs or expanding the testing capabilities of the existing ones.

A more important issue affecting OTICs globally is the variation in specification maturity. Work cannot yet begin in earnest on the testing set-up for some certificates for fear of future changes. The WG4 OFH specifications are considered mature and changes requiring a major overhaul of the testing set-up are not expected.

A further variable in this equation to be considered is the Telecom Infra Project’s (TIP) own badging program. Given the close cooperation and overlapping membership between TIP and the Alliance, there are some questions about the nature of the coexistence between their respective standards programs. Talks are currently underway between the two to better define these programs’ individual roles and relationship, and we are expecting announcements on the results of these discussions in the coming weeks and months. While the impact of the discussions on the Alliance program is not yet clear, decisions are being made with the ongoing talks in mind, leading to further delay.

There is also the issue of incorporating and clearly defining the role of Alliance plugfests within the testing and interoperability ecosystem. Plugfests, which so far have featured heavily in testing, and for a long time provided one of the only occasions on which especially smaller equipment vendors were able to test specifications adherence and performance in multivendor deployments, are to be “rebranded”. It is the OTICs which are to bear the brunt of testing and certification loads, while plugfests are to be events where new proofs-of-concept or trial experimental applications are demonstrated in a cooperative and multivendor forum.

This change is nothing unexpected, and will see the OTICs reclaim testing authority, which, in absence of a central power, had drifted towards the plugfests. One should not expect the trend of certificate or badge awards happening during plugfests to continue much longer, at least not for mature specifications.

For newer ones, or those subject to future updates, plugfests might continue to occupy a vital role in testing and inter-vendor cooperation, however. This will largely be dependent on OTICs willingness to engage with immature specifications. The Open RAN Alliance and ORAN movement will remain at risk of fragmentation and will continue to be vulnerable if its standards cannot find a way to stay abreast of new developments and technological innovations.

The C&B program, once operational, might still face some potential challenges. The interest from large RAN equipment vendors is unclear. Open RAN deployments and trials seen so far have only rarely been multivendor. MNOs largely prefer single-vendor systems, at least locally, to ease integration and maintenance challenges.

Interoperability and E2E multivendor systems have, until now, not been a priority. Details about the exact technical specifications of various Open RAN deployments have also been few and far between, and there are doubts over the adherence of the deployed equipment to Alliance specifications. The C&B program might see a slow initial adoption, due to much of the equipment in use simply not being up to standard.

Additionally, a cautious approach from large vendors might not be all that surprising, considering they may have a vested interest in promoting their own technologies and products, rather than emphasizing interoperability, and this has been the case so far.

There is also the fact that in the absence of a mature ecosystem, those essentially greenfield operators best placed to harness Open RAN from the outset for freedom of choice and potentially reduced costs have gone it alone. Rakuten is an obvious example, which has gone further by commercializing its platform and targeting operators around the world. Among its scalps is the new German MNO 1&1 Drillisch, part of the United Internet AG Group, which acquired two blocks of spectrum in the 2 GHz band and five at 3.6 GHz in 2019, spending just over €1bn.

1&1 was initially drawn to Open RAN by Rakuten’s example, and then opted for its platform after the Japanese operator made it commercially available. 1&1 should now become the first European operator to build a network entirely based on Open RAN but using Rakuten’s platform rather than waiting for wider certification. Although a new operator, United Internet AG itself has experience of mobile service provision having been an MVNO with over 11m customers in Germany, riding over Telefónica’s and a to a lesser extent Vodafone’s network there.

In the USA, Dish Network as a new operator is in a somewhat similar position, although differs in having a Master Network Services Agreement (MNSA) with T-Mobile USA to give its customers access to 5G services while it builds out its own network. That network will comprise an Open RAN ecosystem just as Rakuten has in Japan, though it is not clear yet whether this will also result in a platform Dish will commercialize externally. Certainly, its high profile threatens to usurp AT&T’s traditional role as the perceived leader in driving open network initiatives in the USA, although both operators are working together to accelerate progress in the market.

Together with CableLabs, the R&D arm of the US cable providers, the two operators hosted O-RAN Alliance ‘PoCfests’ earlier this year. These provided testing and interoperability events but claimed to go beyond mere plugfests by spawning full proof-of-concept (PoC) trials too. So here at least the operators are to some extent dovetailing with the O-RAN Alliance testing and certification program.

The announcement of the Open RAN Alliance’s certificate and badge program can be seen then as an important step towards development and maturing of the Open RAN ecosystem. While the program is off to a slow start, the field is still in its infancy and there is plenty of time to catch up. There is still need for a ‘stamp of approval’ system from an institution respected across the Open RAN community.

The benefits to MNOs and equipment vendors remain the same. Small vendors especially stand to benefit enormously from a central catalogue of Open RAN approved equipment, through which to advertise their products. MNOs on the other hand would equally appreciate a central registry of devices from which they can pick the one most suited to their individual needs.