MADRID – FYUZ – Telcos haven't always been complimentary about Nokia's claims to be an open RAN convert, and the Finnish vendor's occasional surliness about open RAN performance has probably not helped its case. But that all seemed to change this morning when Yago Tenorio, a senior Vodafone executive and one of the high priests of open RAN, gave his blessing to products designed by Nokia and US chipmaker Marvell as a "fully compliant open RAN system." For the first time, Tenorio told Light Reading, Europe has a big vendor committed to open RAN.

It is one of several big announcements Tenorio is serving up at the food-themed FYUZ (pronounced fuse) event in Madrid today, run by the Facebook-led Telecom Infra Project, which Tenorio chairs, and the O-RAN Alliance, the group developing open RAN specifications. The organizers have apparently seized on the flavor combinations in cooking as the perfect metaphor for open RAN, whose chefs are attempting to mix ingredients from different vendors without giving telcos a technical form of indigestion.

Figure 1: A traditional mast site where all the components are provided by Ericsson.
(Source: Ericsson)

Just about everyone seems to agree that systems integration – when all those ingredients are brought together in one simmering pot – is the most difficult job of all. That much was acknowledged by TIP in slides previously leaked to Light Reading. Preparing a meal from scratch, instead of ordering it ready-made from a giant vendor, "provides choice of suppliers but creates inefficiencies in integration, validation and lifecycle management," said the organization.

Tenorio believes working from a common recipe could help, and so Vodafone has signed a memorandum of understanding with Japan's NTT DoCoMo. "We will be using the same procedures and protocols and scripts to the point that we are going to connect NTT's lab in Japan with our lab in Newbury," he told Light Reading. "This sends a message about how the industry is responding to the need for an easier systems integration."

Systems integrator tyranny

The hope is that such a partnership could produce a sort of open RAN equivalent to the celebrity chef cookbooks that hit stores around Christmas. The main audience could be the smaller operators that lack the resources to invest in their own systems integration teams. "We get calls from non-competing operators every week who want to know," said Tenorio.

He agrees this could be a potential new revenue stream for the likes of Vodafone, but the chief goal is to coordinate activities, avoid any duplication of effort and reduce cost. TIP could ultimately be involved through what its board calls an "Open RAN Innovation Hub," a kind of central repository of expertise. Once it has shown a particular flavor combination works, there is less to go wrong in the kitchen.

Implicit in all of this is some degree of wariness about relying on third-party systems integrators like Accenture, Tech Mahindra or even Rakuten, the Japanese company now touting its open RAN expertise. "The role of TIP is to make sure you keep everyone honest," said Tenorio. "If there is nothing else but a systems integrator, the risk is you go with Tech Mahindra, they have all the knowhow, and you are doing open RAN but depending on them." He worries this could become a new form of lock-in.

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Tenorio also slams any suggestion that open RAN's new specifications could eventually produce "plug-and-play" technologies, allowing an operator to build an open RAN network as easily as a child assembles Lego. "That is totally unrealistic," he said. 3GPP technologies, he points out, have been in the field for many years and still nobody would deploy them without extensive testing, even if some of this happens inside the facilities of the big kit vendors.

Does this not mean the O-RAN Alliance mission is ultimately pointless? NTT DoCoMo, after all, has been combining radios from one vendor with baseband products from someone else long before that organization existed. If it cannot eliminate the need for systems integration, what purpose does it serve? "If not for the O-RAN Alliance, we wouldn't be talking about open RAN," said Tenorio. "It is instrumental. Without specs, it would be fragmented and not reach scale."

A side order of chips

The Nokia open RAN breakthrough that Tenorio heralds combines a Marvell accelerator with massive MIMO technology and means replacing it or substituting it for another compliant vendor will be much easier, according to the Vodafone executive. His company is also collaborating with Samsung, the main supplier for its Huawei swap-out in the UK, on integrating the very same Marvell chip.

Vodafone's R&D facilities in Malaga are currently weighing different types of acceleration and trying to figure out their respective benefits. With inline, a system preferred by Marvell, much of the baseband processing is offloaded onto a separate chip. Intel, meanwhile, has been touting an alternative called lookaside and, more recently, something it refers to as integrated acceleration. Unsurprisingly, these continue to rely more heavily on the central processing unit that typically comes from Intel in the shape of an x86 chip.

The main gripe for Tenorio is that the software running on these different chips is not portable. "Even if you use FlexRAN [Intel's reference architecture], you have to design your software in a particular way using the instruction set FlexRAN gives you," he said. "Once coded for FlexRAN, it is not portable for another accelerator – you can only use Intel from that point on." The next wave of standardization needs to be on these Layer 1 interfaces, he says.

Light Reading will have more on that subject later this week. In the meantime, Vodafone is now preparing to expand its European open RAN activities outside the UK and into Germany. A commercial pilot will involve two clusters in two different cities but the ambition, as in the UK, is to go much bigger. The likelihood is that Vodafone will stick with many of the same vendors and tools it has used in the UK, including Samsung (radio units and software), NEC (radio units) Wind River (cloud platform), Dell (servers) and Intel (chips).

But the frequencies and radios used in Germany are not identical to those in the UK, Tenorio points out. "Before you start talking about thousands of nodes, you have to start small and make sure you create skills locally, and that your operational processes work," he said. With Vodafone aiming to use open RAN across 30% of its European footprint by 2030, traditional vendors merely paying lip service to the concept may need to watch out. "We meant it and we need to make progress."

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— Iain Morris, International Editor, Light Reading