Microsoft exec slams industry on open RAN readiness

Operators should be able to sit an open, cloudified radio access network (RAN) atop any hyperscaler or so-called "containers-as-a-service" (CaaS) platform. The reality is more complicated. AT&T has admitted that Ericsson's RAN software will not rest exclusively on Nexus, the Microsoft Azure platform that hosts its 5G core. Some functions will continue to reside on Ericsson's cloud-native infrastructure solution (CNIS).

That sounds far from ideal because the whole rationale for cloudification, as far as many experts are concerned, is that said operator can collapse all its network functions onto the same underlying platform, scrap the silos and be more efficient. One of Microsoft's top telecom executives has now delivered a scathing verdict on the supplier community's state of readiness for the open cloud (or O-Cloud) part of open RAN.

"For me, observing the industry, the O-RAN stack is not mature yet," said Yousef Khalidi, the corporate vice president of Microsoft's Azure for Operators business, when asked about AT&T's use of CNIS. "We are very pro O-RAN. All the investment we are doing for AI in the RAN is all O-RAN-centric, and you'll see that with the Janus project we're announcing. But the point is, if you want to buy an O-RAN stack now and deploy it at scale, frankly, I don't see it out there yet. The option out there today is at best a virtual RAN solution from a handful of suppliers. The industry has not moved fast enough on the O-RAN side, unfortunately."

Described in a short online Microsoft post in October, Janus is presented as a monitoring and control system for the RAN intelligent controller (RIC), a feature of open RAN that has been likened to an app store for the network. Microsoft claims Janus can address some of the "latency and safety challenges" in this domain and says it has already been able to deploy three different classes of application – covering 18 apps in total – at a 5G cell site without affecting performance.

Rewriting the code

Prominent telcos have also complained that network software is often still incompatible with infrastructure platforms built by other companies. "The nature of cloud-native is that it can run on any stack," said Gabriela Styf Sjöman, BT's managing director of research and networks strategy, at a recent press briefing. "I think the challenge for the legacy network equipment providers is that they can't afford to rewrite the code. It has been a long journey for them first to virtualize. To then make it cloud-native is a massive investment."

BT, however, has had success in putting various network functions on a platform it has co-developed with Canonical, a UK software company, using Juniper Networks for orchestration along with Cisco and Dell for compute. Functions hosted on that platform include Ericsson's 5G core network applications. "There is lots of flux at the moment around this shift from a virtual cloud to a cloud-native cloud," said Howard Watson, BT's chief security and networks officer, reflecting on broader industry developments. "We are in a good place on this given what we've done, not least because of the skills we've developed."

Yet Khalidi says cloudification is far more advanced on the core network side than it is in the RAN. "Frankly, AT&T led the way, and Nexus and the deployments we have are proof you have disaggregation," he said. "You have the ability to buy off-the-shelf hardware." He blames slower RAN progress on a "business reason" rather than a technology one.

Nokia last year made a show of promising to scrap both Nokia container services (NCS) and Nokia cloudband infrastructure software (CBIS), two in-house platforms designed to host its own applications but not any third-party alternatives. "We're seeing a change in that market now where customers increasingly want to build a horizontal solution, so a standard architecture, standard cloud infrastructure, for all applications coming from all suppliers into their network," said Fran Heeran, Nokia's general manager of core networks, cloud and network services, at the time. "And that's not a market that Nokia was pursuing."

It has instead announced Red Hat as its primary cloud partner, transferring staff and assets to the IBM-owned company as part of the arrangement. But Tommi Uitto, the head of Nokia's mobile networks business group, said the goal is to ensure Nokia's RAN technology can be hosted on any platform. "We have an any-cloud strategy," he told Light Reading during Mobile World Congress (MWC) this week. "Nokia's blueprint today is Red Hat, but we are also prepared for it to be OpenStack or VMware or the hyperscalers."

Google enters the picture

While CNIS does remain a part of the mix at Ericsson, the Swedish kit vendor announced a partnership with Google last September to run its virtualized RAN software on a Google-supplied stack. Commonality at the hardware level is provided by x86, the chip architecture developed by Intel and AMD. Yet Granite Rapids-D, Intel's latest x86 product for the RAN market, looks far more customized than the processors typically sold to data center players.

"They gave us some information, but we don't know a lot of what is inside, so it is a bit of a black box," said Matteo Fiorani, the head of Ericsson's cloud infrastructure unit, when discussing the Google partnership last year. "We have passed on specific requirements of what we need to be able to run our application, and they have given us feedback on what they will provide us and told us what would be inside servers and racks, but not in detail."

AT&T is not the only big telco investing in Ericsson's cloud RAN technology. At MWC this week, Telefónica Germany announced plans to begin a rollout in Offenbach, near Frankfurt, in the first half of this year. The operator's statement on the deal notes it will use Intel chips in HPE servers. Just like AT&T, it will also be relying on CNIS.