While the benefits of Open RAN (advantageous network economics and deployment flexibility
chief among them) are widely touted, there are also well-articulated issues associated with the technology.
One question is whether operators are trading reduced capex related to RAN infrastructure for increased integration costs as someone has to do the work, and be paid for it, of integrating
multi-vendor kit. There are also questions around the ability to scale Open RAN in a way that
retains performance parity associated with an integrated infrastructure stack. And another issue
we’ll explore further on this paper is around security.
Ericsson’s Paul Challoner, vice president of network product solutions, acknowledged there’s
“potentially [a]reduction in capex through commoditization of some of the products, [but]how
many of the integration costs are one time and how many are recurring throughout
hardware/software lifecycle management?”
Challoner continued: “I think the industry has to work through those integration challenges.
Ultimately it can be done. But the specifications need more maturity and there needs to be
constructs, open lab structures, to do that integration. But that’s going to take some time to work
He also raised the question of scalability, particularly as it relates to supplying compatible radio.
“Who is it that makes the radios? And which Open RAN vendors can then provide millions of
radios around the world every year?” All in all, he said of Open RAN, “I think it’s a journey. We
need to take the Open RAN architectures and evolve those so they can meet the demanding
requirements of today’s networks.”
To address the perceived challenges of integration, Viavi’s O’Donnell points to test and
validation work that can be done in laboratories settings or environments like the Open Test and
Integration Center, a consortium focused on letting operators and vendors test out Open RAN
solutions prior to deployment.
This gets to the heart of the question around, if an Open RAN site has an issue, which of the
multiple vendors does an operator look to? “If somehow the overall KPI is failing, how do you
point to the individual component that’s causing the problem?” he mused. “That’s going to be an
issue. But, from our point of view, it’s testing. The testing and the finger pointing will be worked
out in the lab…before it’s deployed. If you’re doing a network slicing test and the latency is not
matching the requirements, then it’s in the lab that you’ll be able to monitor the latency KPI from
the RU to the DU and from the DU to the CU.”’
More on balancing capex savings with more complex integration, Radisys Vice President of
Engineering Ganesh Shenbagaraman said, “This is a question that is often seen from an operator
point of view. There has been a tradition or norm of just having two or three vendors. The new
dimension or the new reality of having multiple vendors is sometimes scary for the operators.
One reason is the integration costs and second is the time taken to integrate. That is not a
completely solved puzzle yet. There are companies looking at this space, Radisys being one such
So what do two major U.S. operators think? In September, the U.S. Federal Communications
Commission brought together a variety of Open RAN stakeholders for its Forum on 5G Open
Radio Access Networks. During the event, AT&T’s Laurie Bigler, assistant vice president and
tech staff member for access analytics and systems, pointed to trials of the Radio Intelligent
Controller (RIC) the operator has conducted on its millimeter wave 5G network in New York as
a proof point of the company’s interest, but also noted challenges around “ensuring the
reliability, integrity and performance for our customers,” which she acknowledged is not unique
to Open RAN.
“O-RAN is still developing specifications at this time and some are further along,” Bigler said.
“Having specs alone does not guarantee interoperability or performance. We really see that
integration is the biggest challenge ahead. You really don’t find the issues or gaps with the specs
until you actually try to integrate two vendors’ equipment.”
In terms of how Open RAN fits into AT&T deployment plans, Bigler said she foresees a
“gradual introduction of Open RAN into our existing network.”
Lori Fountain, director of network infrastructure planning with Verizon, made clear that Verizon
is “a player in O-RAN as well as an early adopter,” but said incorporation of the emerging
technology is “a journey. We’re kind of at the first step of that journey, which is the ability to
mix and match baseband software with an open [radio unit]and we’re excited.”
She continued: “The challenge we see at Verizon is scale and maturity. We have a mature
network here at Verizon and it’s not a greenfield network. We support O-RAN entirely and know
it is the future. We will be adopting this critical architecture and in a timeframe that successfully
allows the network to mature gracefully but, at the same time, protecting our customers.”