Opening and virtualizing the radio access network (RAN) is a pursuit with almost unanimous support — at least on the surface. Operators, software makers, and equipment vendors have coalesced around this effort with varying degrees of force.

Motivating factors differ, but the widely expected outcome is generally the same: a disaggregated, software-driven, open framework for RAN. Multiple and oftentimes overlapping initiatives are being driven by alliances that have earned the support of the biggest companies in telecom and new players that are emerging.

The proposition of this more flexible network architecture has also shifted from cost benefits to a less restrictive framework that opens up opportunities for third-party development, according to Stefan Pongratz, VP at Dell’Oro Group. Operators want more competition in the RAN market, and efforts to open and virtualize the RAN are contributing to that goal, but increased complexity in the RAN and mobile network core is muddying the waters of that request, Pongratz wrote in a research note.

“The [research and development] required to provide a competitive 5G portfolio with the increased complexity in the RAN and core, the increased use of machine learning and automation in services, and the proliferation of new use cases spanning across a wide range of industries will possibly move the needle in the opposite direction and complicate the entry for new entrants,” he concluded.

Ericsson, Nokia, and Samsung have much to lose if the RAN space flattens to a point where their equipment becomes a commodity. As such, the giants of RAN (only Huawei has a greater share of the market) are making their presence and positions known by contributing and participating to open RAN (O-RAN) and virtual RAN (vRAN) initiatives.

Indeed, disaggregating network hardware from software on an open structure, thereby negating the value of tightly integrated but heavily proprietary RAN equipment, seems to be in conflict with the business model of RAN vendors. Executives at each company shared a slightly different perspective on the trend toward openness and virtualization in interviews with SDxCentral at MWC Los Angeles 2019.

Ericsson Expects Variances in Architecture

“For us it’s fundamental that when we see technologies that can enable our customers to become more efficient and more flexible, more innovative, we need as a technology leader to take those on board,” said Ericsson EVP Fredrik Jejdling.

“In that matrix we’d rather have a very tight dialogue with our customers and with the industry, the ecosystem around cloud, to make sure that we build something fully validated that makes a lot of sense for our customers,” he said.

“There are a lot of elements in the core domain or in the IT world, if you may, that will apply here,” Jejdling said. However, he adds, “this is such a unique, very complex environment to deliver radio performance and we’ve solved it with bespoke ASIC development…The requirements around flexibility and other things means that we need to evaluate those vRAN structures again in the eyes of the customer because they are requesting this.”

At a high level, Ericsson has made progress in virtualizing the control and traffic layer planes to automate server functions, but “it’s never been to the level of full-stack virtualization, a full cloud RAN structure,” Jejdling said.

Ericsson joined the O-RAN Alliance in February 2019 and recently announced a partnership with Nvidia to build what the companies describe as the “world’s first software defined 5G RAN.” Jejdling described it as an exploration and further evaluation of opportunities in vRAN.

“I think ultimately there will be a mix between various types of architectures,” he said. “I don’t think we should look at virtualization as the only element of building cost efficient, high-performing radios.” There will likely be “more heterogeneous networks where certain use cases will be very suitable for more virtualized applications.”

Nokia Welcomes New Players With Caveats

The foundational components of 5G are also fueling this wave of development. Mike Murphy, CTO for Nokia’s business in North and South America, said the network architecture fundamentally changes from a “centralized architecture to a more distributed [architecture] with more open interfaces and more virtualized systems.”

Simply put, “that allows the entrance of some new players, particularly when you go virtualized and you start distributing across the country,” he said. “I don’t think the standalone [5G core] necessarily introduces new players by itself. What it does to introduce new players more so is this drive to what we call openness.”

Most network infrastructure is comprised of private interfaces today and moves are underway to make those publicly defined by forums enabling operators to theoretically mix and match hardware and software from multiple vendors, Murphy explained. “In some places that’s easier, in some places it’s more difficult. This is all fairly new so this whole process will develop over time.”

Vendors are taking different approaches to this trend, he said. “One is the defensive approach…The other approach is nonetheless, this is inevitable and it actually is good for the industry, so let’s support it wholeheartedly.”

Count Nokia, a member of the O-RAN Alliance, in the latter. “We support, as a basic rule, open systems and open interfaces,” Murphy said. “We believe that this is the right way for the industry for the long term.”

However, he also warned about potential problems that could arise when software or hardware from smaller, less battle-tested vendors hits the network. “When you open the window, flies come in. Of course you have to be good, you have to have a great product.”

Samsung Touts Operator-Led Focus

Samsung, which is also a member of the O-RAN Alliance, believes in the benefits of open RAN and is actively contributing to advancements in the space, said Alok Shah, VP of networks strategy at Samsung. “We’re building products that are O-RAN compliant now, and from our perspective it’s a great opportunity for operators to get more flexibility in their network, get more best-in-class solutions into their network,” he said.

“It’s not for every operator” though, because “it does require a different model when it comes to support,” validation, and integration, Shah said. That said, the O-RAN Alliance has made strides in defining those interfaces so that any two products that support the same version of O-RAN will indeed be interoperable, he explained.

“When it comes to support expectations, there are certainly operators that prefer one neck to choke and that’s fine…There’s certainly nothing wrong with that model. But I think we as an industry will be able to innovate” and make those support needs more manageable in a multi-vendor setup, Shah said.

“There are a number of operators who are very supportive of O-RAN and I think what makes O-RAN really powerful — the fact that it’s operator led, not vendor led,” he said. “Ultimately it’s operators like AT&T, and Verizon, and DoCoMO, and Vodafone who have really led this and they’re demanding that these interfaces truly are open. We’re seeing a tremendous amount of resources from the operators being applied there.”