The Open Networking Foundation (ONF) is steering resources to open the radio access network (RAN) because the O-RAN Alliance is dropping the ball. The SD-RAN project marks the first time ONF has assembled resources for the RAN, and it is convinced the timing and market conditions are ripe for the creation of a more “truly open RAN ecosystem.”

Since the O-RAN Alliance was formed in early 2018 by a group of global mobile network operators, RAN vendors have joined the group. And, “like other standards activities we’ve seen elsewhere repeatedly,” are starting to “advocate for standards that are beneficial to their businesses,” said Timon Sloane, VP of marketing at ONF. 

That RAN vendor influence in the O-RAN Alliance is effectively precluding operators from directing the work to where they want it to land, he said. “What we’re seeing is that more vendor-specific contributions are being made and some are even in binary form, it’s not even open source.”

As such, it’s no wonder that the same major operators that founded the O-RAN Alliance — AT&T, China Mobile, China Unicom, Deutsche Telekom, and NTT — are now founding members of ONF’s SD-RAN project. Other founding members include Facebook, Google, Intel, Radisys, and Sercomm.

ONF is walking a fine line here by generally supporting the movements underway at the O-RAN Alliance while calling out its perceived inadequacies and fostering efforts to seed SD-RAN project outcomes back to the community at large. The SD-RAN project will consume the architecture and specifications from the O-RAN Alliance, determine where improvements are needed, and feed those activities back to the community, Sloane explained. 

“We’ll do some code sharing where it makes some sense and certainly we want to have common APIs and we’d love to have interoperable implementations come out of open communities,” he said. “We’re not trying to fork off from O-RAN. What we’re doing is compatible with O-RAN and is really, in our view, just helping fill some of the holes.”

ONF intends to protect itself from overt RAN vendor influence by adhering to the same model it has followed on other projects — develop a solution, demonstrate its capabilities, and effectively force industry participants to look at the opportunity with a fresh eye, Sloane explained. 

“With that the industry is able to come to it again and move beyond this inflection point. And so we’re right at that inflection point now,” he said. “Instead of just arguing, what we at ONF do is say ‘OK, we’ll go do it.’ That’s why ONF has an engineering team. ONF is different than every one of these organizations because ONF is an engineering organization” and at least 80% of its staff are engineers. 

“We think that that’s the model and running that model in parallel with O-RAN can have that seeding function and help push the industry through, and that’s what we’re hoping and intending to do,” Sloane said.

“What’s been delivered out of O-RAN hasn’t yet delivered the capabilities necessary,” he said, pointing specifically at the need for a microservices-based RAN intelligent controller (RIC), and the development of applications and interfaces for xApps to control the RAN.

The project is initially focused on developing an open source RIC and architecture that enables operators to gain more control over functions that are typically implemented as proprietary features on base station equipment. 

“The operators really are pushing for separation of hardware and software and for enabling new innovations to come in in software without it being tightly coupled to the hardware that they purchase. And xApps are where the functionality of the RAN is to be housed, and so in order to do this in a meaningful way you have to be able to do meaningful functions in these xApps,” Sloane said.

ONF plans to mix vendor proprietary and open source xApps to get closer to that vision, he explained. “These solutions are going to definitely include closed source RAN components. It doesn't mean the full RAN goes open, but it does mean that some critical key building blocks go open.”

RAN vendors aren’t moving aggressively toward an open RAN framework and are particularly reluctant to cede any control to the RIC and the xApps, Sloane said. 

Nokia, which claims it’s making a big push to embrace open architecture in the RAN, still isn’t fully embracing the level of openness that operators seek, Sloane explained. “Handover is not possible in an xApp. Handover is still a baked-in feature in their device. That’s just one concrete example of the spectrum of functionality that’s still not really lifted out, still not really open, or as open as the operators want.”

The RIC and xApps are the first of many steps that need to be taken to get the open RAN community thriving and reinvigorated, he said. “I suspect there’ll be other things to go after, other pieces, that’s the history everywhere else so I expect to see the same thing here.”

The RAN space is ripe for open source and ONF, through its SD-RAN project, hopes to help lead that charge and push it into reality. “RAN is the last bastion of closed and proprietary. We’ve gone after Ethernet, we’ve gone after mobile core, we’ve gone after [passive optical networking], we’ve gone after all of these other pieces,” Sloane said, highlighting ONF’s previous successes in this realm. 

The first wave of innovation gleaned from the SD-RAN project will be available later this year and trials are expected to get underway early next year, according to ONF.