Open radio access network (RAN) technology has shown a paced path into the market, a speed which has been dictated by complex technological and competitive challenges that have seen many of the initial deployments limited in their ability to take full advantage of the openness of open RAN.

Dell’Oro Group recently touched on this issue, noting that the openness of open RAN remains limited. While the overall open RAN market was set to generate nearly $10 billion in revenues, “multivendor RAN adoption and expectations remain limited.”

The firm pointed to market concentration as measured by the Herfindahl-Hirschman Index (HHI) and found that “the RAN market is now classified as ‘highly concentrated’ (HHI > 2500) in five of the six tracked regions. This suggests that the supplier diversity element of the open RAN vision is fading.”

Open RAN was initially touted as a way for operators to pick-and-choose RAN components regardless of their vendor of origin, with all of that equipment then able to link seamlessly by standards overseen by the O-RAN Alliance. This would allow a greater number of vendors to potentially participate in the market, driving down costs and opening up more negotiating opportunities for operators.

Unfortunately, the O-RAN Alliance was forced to implement some looseness in those standards in order to satisfy its members and the breadth of the technology. That led to significant interoperability challenges, which forced many forward-leaning operators that took an early open RAN plunge to become system integrators (SIs), a role they had no interest in tackling.

David Zufall, VP wireless infrastructure development at Dish Network (now Boost Mobile), touched on this frustration several years ago during a panel discussion at an industry event. Zufall explained that while the O-RAN Alliance had been the focal point for standardization efforts, real-world deployments had shown that operators were needing to take more control on those efforts.

“I think that’s going to be up to [operators] to force it among our vendors,” Zufall said. “We can define the basic layers, that it’s going to be a cloud-native environment and we have our principles, so I think we can define the environment. But I think we have to take the bold step and say ‘I am going to have a multivendor network and I am going to have a multicloud network and I’m not just going to use somebody’s middleware to enable the interoperability that happens to work on both of them. We were willing to do it on the RAN and we saved some money. We’re willing to do it on hardware, but we have to go to the next step, and I think that’s on the operator community to kind of force it across our vendors.”

Open RAN’s open highs

Zufall's money reference is a big part of the open RAN story. The telecom equipment vendor list today is much smaller than it was a decade ago due to deep consolidation, which has limited the pool of vendors operators are able to bid against each other for business.

Bernard Bureau, VP of wireless strategy and 5G services at Canadian operator Telus, recently explained to SDxCentral the considerable costs tied to RAN deployments. Bureau noted that RAN, in general, is the most expensive aspect of a mobile network, with “80, 90% of the money in network goes toward” RAN, “because we’ve got so many nodes, so many sites, so many network elements.”

That cost structure highlights the financial incentive operators have in championing open RAN, an incentive Bureau laid bare when describing Telus’ legacy RAN technology path.

Bureau explained that Telus witnessed first-hand the top-heavy nature of RAN spend, noting that the operator worked through two complete radio swaps of legacy non-open-RAN equipment over the past two decades that he called “heartbreaking.”

“It's like putting money in a pile, in a campfire, and lighting it up,” Bureau said. “It's disastrous in terms of impact.”

Telus has since gone full-speed toward an open RAN architecture, which is altering that operating model and cost structure. This includes efficiencies down into the core of the network.

Others are starting to see similar benefits.

“Having the ability to pick and choose vendors based on their capabilities and knowing that they can interoperate on either side of that equation and yield high performance, high quality, low cost, whatever your goal is, for the network,” Adam Koeppe, SVP of technology planning at Verizon, told SDxCentral late last year as part of that carrier launching a multivendor open RAN distributed antenna system (DAS). That system was deployed at the University of Texas in Austin and the Austin Convention Center using equipment from Samsung and CommScope running on top of Verizon’s edge-focused virtualized cloud architecture.

“In this case, you’ve got a Samsung component and you’ve got a CommScope component in the DAS system, so that hasn’t been done before. It represents, really, the true spirit, if you will, of [open] RAN where you have two vendors in that supplier system on either ends of that,” Koeppe added.Koeppe also touted Verizon’s level of announced open RAN detail and to the O-RAN Alliance specification tied to the deployment.

“Certainly, a very popular topic in the industry,” Koeppe said of open RAN, adding “not a lot of specificity coming out of operators in our industry related to actual O-RAN deployments.”

This level of trust was echoed by Boost Mobile CTO Eben Albertyn who during a “fireside chat” at this year’s CCA Mobile Carriers Show shot down open RAN complexity concerns. The executive noted that Boost Mobile has been able to deploy a high-performing open RAN-based 5G network that performs on par with well-established networks deployed by rivals.

“The perception that I pick up sometimes when I speak to the industry is that open RAN is not mature,” Albertyn said. “As I've explained, the other three have been optimizing that network for about 30 years now. We've been at it for about a year and a half and we've beaten them on quality in the biggest city in the world, in New York City. So open RAN is real and it's not as technical as people think. It's a very mature technology.”

Albertyn did admit that Boost Mobile struggled through the initial deployment, hindered by it being one of the first in the world to push a greenfield cloud-native deployment. But, the move has allowed the carrier to be more aggressive in vendor management.

“I think open RAN and the technologies that we’ve used goes far and beyond just that of the radio, it changes the entire way of interacting with your supply chain and your landscape, and there is a lot more control that allows you to manipulate cost and quality in a way that suits your situation,” Albertyn said. “We didn’t want to go through all of these pains. We didn’t want to go through these changes, but we were, I think, extremely grateful that we had the opportunity to change at will when you’re in the situation changed.”

Those changes included having to become the de-facto SI for its own network deployment, which it initially wanted to have its vendors deal with.

“We were of the conviction that we could go into this journey with the use of partners, and they would actually help us to do most of the heavy lift. That couldn’t have been further from the truth. We actually crashed-and-burned completely,” Albertyn explained. “We had to become the systems integrator ourselves. We had to become an architect and the creator of the underlying infrastructure of the network itself. And we had to become the hub of the spokes around. That was a surprise and a huge slap in the face. We realized that the route that we fashioned was a complete dead end.”

Is it really open?

However, Albertyn’s description of that process also reinforces Dell’Oro Group’s proclamation over the lack of open RAN openness.

The diversity of equipment suppliers involved in many of these initial deployments have been limited to just a few vendors. The most common model has been to rely on a single provider for the main open RAN management underlay, with perhaps just one or two other vendors approved to provide the actual open RAN transmitting components.

This was highlighted by Vodafone’s recent announcement of vendors to power its wide-ranging open RAN deployments. The carrier selected long-used vendors like Ericsson, Nokia, and Samsung to supply components in specific markets with little overlap.

AT&T, which has been one of the open RAN market's leading operators, made a similar move with its extensive deployment plan.

The carrier tapped Ericsson to provide its Intelligence Automation Platform (EIAP), which is the vendor’s service management and orchestration (SMO) platform. The EIAP will span across multiple domains, including the service level where it can control the cloud RAN and traditional RAN functions, the radios, and the hardware. On top, AT&T has so far only named Fujitsu and Mavenir as approved open RAN vendors.

AT&T COO Jeff McElfresh said that network testing showed the two vendors as being “a little bit more advanced, little bit more mature, I should say, in their technology.”

McElfresh’s maturity comment is important for the still coalescing open RAN environment.

AT&T made some waves when it first announced its open RAN push by relying on Ericsson as the underlying platform provider. McElfresh reiterated that the move made sense due to AT&T’s long-standing work with the Swedish vendor and its entrenched infrastructure presence.

McElfresh added that AT&T’s decision to go with Ericsson also propelled that vendor’s adoption of open RAN principles.

“We required them to open up their radio architecture, which up until the deal that we drove, they were somewhat unwilling to let some disruptive technology partners into the mix,” McElfresh said.

Analysts have noted that despite this progress, challenges have remained.

“Open RAN has the promise of interoperability with the interfaces being standardized and then you give each of the application providers and hardware providers the ability to connect to the interfaces in a standardized way,” Recon Analytics Founder Roger Entner noted in a podcast last year. “In theory this should work really well. In reality, it doesn’t work very well.”

Entner pointed to Boost Mobile’s initial deployment struggles, which have been linked to AT&T’s controversial decision to rely heavily on Ericsson as the base of its open RAN efforts.

“It’s no surprise that, for example, AT&T when they are going to open RAN they gave everything to Ericsson to make sure everything works with a single-stack vendor and there’s no finger pointing, and only then will they open it up to other radio vendors and potentially other parts of the stack as well,” Entner added.

Open RAN security challenges

Analyst firms have also noted that this openness has drawn questions around network security.

Analysys Mason in a recent operator survey found ongoing concerns over deeper levels of open RAN complexity. Specifically, the analyst firm found one-third of operators think open RAN will make security management harder, though it should also be noted that another one-third of respondents expressed the opposite opinion.

“Such contradicting opinions about open RAN security are common,” James Kirby, senior analyst at Analysys Mason, wrote. “For example, some pundits claim that the increased number of open interfaces will pose a considerable security challenge while others argue that proprietary interfaces are not necessarily more secure and that the greater visibility into open RAN architectures makes vulnerabilities and threats easier to spot. Given that security failings can lead to hefty fines and reputational damage for operators, this uncertainty is contributing to slowed open RAN adoption.”

Kirby added that it’s imperative for the industry to work on better open RAN security standardization in order to alleviate concerns.

“To drive progress toward widespread, at-scale commercial adoption of multivendor open RAN (and support ecosystem diversity) it is imperative that progress is made to build confidence in its security and reduce its related operational burden,” Kirby states. “Critically, the industry must advance standardization with a goal to reach recognized security certifications that can create consistency in the ecosystem and de-risk and reduce the burden of multi-vendor security for operators.”

Despite that needed homework, Analysys Mason is positive on market growth, predicting open RAN and virtualized RAN (vRAN) architectures will account for more than 70% of segment vendor revenues by 2030.

Dell’Oro Group is also hopeful of the overall market if not so much in terms of the market’s openness.

“Our long-term view has remained largely consistent since we began tracking the market in 2019,” the research firm noted. “Long-term open RAN growth prospects remain favorable. Although near-term headwinds and business case challenges persist, the broader trajectory continues to point toward greater openness, virtualization, intelligence, and automation across the RAN. We remain optimistic about the outlook for open RAN and cloud RAN in the latter part of the forecast period, though the attractiveness of the multivendor RAN model continues to be limited.”

This article first appeared in the SDxCentral Open RAN Supplement. Register below to read the whole supplement for free