Open RAN, as the name implies, is meant to be open to multiple vendors, both hardware and software, that work together to achieve interoperability in accordance with an operator’s needs. But as incumbent radio vendors like Nokia throw out terms like “open but integrated,” at what point does an open RAN trial or deployment stop being open?
As with most open RAN discussions, we’ll look at Japanese operator Rakuten Mobile for relevant proof points. Rakuten Mobile has claimed the world’s first virtualized, open network. For its LTE deployment, Nokia worked with Altiostar to join the former’s radio with the latter’s baseband software with the whole thing running on a Cisco virtualization platform. General industry consensus suggests that this fits the definition of open.
But it’s important to consider what open fully entails, Altiostar’s Shabbir Bagasrawala told RCR Wireless News in a recent interview. “Open is probably from my perspective the fact that we’re creating a modular RAN. There’s multiple reasons why there’s this drive for modularity. I think there’s an industry-wide recognition of need for supply chain diversity,” which can help create cost savings, competition and stability, he said.
Another angle becomes apparent post-sales, Bagasrawala said, is the ability to pull out one modular pice of the RAN and put in something different. “My concept of open is…how can you take one module and replace it with another. That’s what I classify as open.”
Regarding a recent Nokia/AT&T Radio Intelligent Controller trial involving a Nokia radio, Nokia baseband, software developed by the O-RAN Alliance and other open-source software, Bagasrawala questioned the applicability of the “open” descriptor.
For its part, Nokia has been ramping up its position relative to the still nascent open RAN space with CTO and Nokia Bell Labs President Marcus Weldon recently floating the term “open and integrated. Not all openness is good and not all closed-ness is good,” he said. “And equally, not always is it necessary to be highly integrated and in many cases it’s good to be more loosely integrated and dynamically interworked. Maybe where we should be aiming…is somewhere in the middle.”
On June 23 Nokia announced an update to its 5G AirScale Cloud RAN with an emphasis on O-RAN compliant architecture, including compliant interfaces between the radio unit, distributed unit, radio access point and centralized unit.
Altiostar recently announced a collaboration with open RAN vendor Mavenir to “deliver a wide portfolio of radios based on OpenRAN principles for the U.S. market. Both companies will be supporting the development of radios through third party OEMs that will be based on O-RAN open interfaces and will address the frequencies of Tier 1 and regional/rural operators in the U.S.”