• Major UK operator Virgin Media O2 (VMO2) has committed to an initial, if somewhat limited, commercial Open RAN rollout
• The move is part of parent Telefónica’s Open RAN commitment 
• Somewhat unexpectedly, Mavenir has been selected as VMO2’s main technology and integration partner
• NEC and Rakuten Symphony miss out
• VMO2 speaks exclusively to TelecomTV about the move

Following years of testing and trials, major UK operator Virgin Media O2 (VMO2) has finally committed to a commercial Open RAN rollout, and has selected Mavenir as its key partner for the deployment.

It was only ever a matter of time before VMO2 pulled the Open RAN trigger. It has been testing open, disaggregated, multivendor radio access network (RAN) alternatives for years already, and one of its parent companies, Telefónica, has previously committed to using Open RAN systems for at least 50% of its 5G network expansion during the 2022-25 timeframe. 

And it seemed VMO2 was gearing up for a significant move last September when it announced a commercial pilot with NEC and Rakuten Symphony (the Open RAN-focused vendor spin-out from Japanese mobile operator Rakuten Mobile), albeit only for a handful of sites offering 4G services – see Virgin Media O2 dips its toes into Open RAN with 4G deployment.

The expectation then was that this would develop into a broader engagement with NEC and Rakuten Symphony, as Telefónica has been developing partnerships with both companies for a number of years, and had identified NEC as a key Open RAN systems integration partner – see Telefónica and NEC to build Open RAN live pilots in 4 global markets as a key milestone toward mass deployment.

But, for now at least, Mavenir, which is involved in a growing number of Open RAN engagements around the world, has snuck in as VMO2’s main Open RAN partner, and will act as systems integrator as well as primary technology supplier for the operator’s first substantial rollout of open radio access network systems. 

Mavenir is supplying its open virtualised radio access network (vRAN) software for distributed unit (DU) and centralised unit (CU) nodes. That software will run on servers comprising Intel Xeon Scalable processors as well as Intel vRAN Accelerator ACC100 and Intel 800 series Ethernet adapter components.

Mavenir will also supply its OpenBeam radio units (including massive MIMO radios) and integrate additional radio units from third-party suppliers. 

So what’s VMO2’s thinking here? According to Neil Geary, the operator’s director of technical strategy and architecture (network) who spoke with TelecomTV exclusively about the move, this development is largely being driven by Telefónica which, along with Liberty Global, is the joint owner of VMO2.

“We’ve come from the Telefónica heritage on the RAN side of our network, so we’re following the approach that Telefónica advises us on, which is to move towards those open interfaces such that it opens up options for innovation and also for longer-term stability and sustainability,” Geary told TelecomTV. 

But VMO2 clearly doesn’t want to give too much away: Geary didn’t want to discuss the size of the deployment with Mavenir, the location of the deployments or whether these are new or existing sites, or what the near-term targets might be for Open RAN-based rollouts as he says the operator is still in the “planning process,” though he noted the Open RAN sites will deliver 5G as well as 4G services. 

“I would love to have some live sites this year, but let's see how we go. This is something new and we know there might be teething problems along the way. But you've got to try this stuff out if you want to transform and innovate. We're not disclosing site numbers or targets at the moment, but it's definitely fair to say this represents our biggest Open RAN deployment to date,” noted the VMO2 man. 

It’s likely that VMO2 is keeping things close to its chest because the rollout will be somewhat smaller than initially planned. One industry source with knowledge of the operator’s plans told TelecomTV that the current deployment will cover about 200 sites, down significantly from an initial plan for 4,000 sites. A VMO2 spokesperson denied the initial plan was ever as large as 4,000 sites, though didn’t push back on the 200 number: “We aren’t disclosing specifics… we’re taking a measured approach,” noted a VMO2 spokesman.  

So it seems like another quite tentative step for VMO2.

“This is the next phase for us on Open RAN,” stated Geary. “There’s a strong belief that these open interfaces are the way to go. We also see the UK government vendor diversification strategy, and this helps contribute to that – the open interfaces give us optionality in the future, so this is what we’re focusing on now with Mavenir… The vision of open networks is something we’re a big fan of, and we’ve actually told all our vendors recently that this is the way we want to head,” he added, which essentially means that VMO2 expects its existing RAN suppliers Ericsson and Nokia to fall in line and support open interfaces that can enable multivendor deployments.  

Geary noted that the tender process for the Open RAN rollout involved “all our usual RAN vendors” but didn’t want to discuss the decision-making process any further, saying only that Mavenir is already a packet core technology supplier and that “we’re deepening our relationship, moving from the core into the access network.” 

But this is also VMO2’s first engagement with Mavenir in the RAN. So why the sudden switch to work with a new vendor? Were previous trials unsuccessful?

“They were small trials, so apart from some learnings and the reuse of some bits of kit here and there, we’re now pushing on with Mavenir,” stated Geary.  

So is this the end of the road for the likes of NEC and Rakuten Symphony? “I wouldn’t say that necessarily, but for now the focus is with Mavenir,” he added. 

TelecomTV understands that VMO2’s decision came as something of an unexpected blow to Rakuten Symphony, which thought it had the commercial rollout deal in the bag. 

But it wasn’t to be and, for the time being, VMO2 is aiming to play things safe, leaning heavily on one company to start with to ease itself into the world of Open RAN deployments.

“We’ve learned some lessons from what other operators have done with Open RAN,” noted Geary. “It’s a big shift for operators… and for those that have chosen to work with a large number of partners and integrate all of those different technologies in the different layers, that might be seen as adding risk. So we’re choosing to use Mavenir’s radios, but there are also some third-party radio units. Without reinventing the wheel, Mavenir is bringing us a set of network ingredients that are known to work together,” and Mavenir will make it all work neatly through its prime integrator role as it’s already pre-integrated and tested and verified, explained Geary, adding that VMO2 isn’t currently identifying the third-party radio suppliers that will be used “on some sites”. 

And which radios are deployed on which sites will be determined by the spectrum and service requirements. As this brownfield deployment is for 4G and 5G, “the radios have different requirements, because 4G bands are all low-band FDD [frequency division duplex] and 5G is all today mostly TDD [time division duplex] massive MIMO,” noted Mavenir CEO Pardeep Kohli. “So we focused on building our own radios where [Open RAN-enabled] radios from other vendors were not available, which is mainly in the massive MIMO area – 32TR, 64TR Open RAN radios… There are not many vendors who have those, so we built those ourselves. But wherever we need low-band radios from partners, we're using them. So if you have a single-band FDD channel, or dual band or triple band, there are vendors who have those radios – we have tested now with 16 different [radio] partners. And if you look at the stack, it’s Intel hardware on the baseband, then you have a cloud layer – whether it's Red Hat or VMware – then our [vRAN] software, and then different radio vendors. So we have put this together and we are offering it as a fully integrated, tested and verified solution,” added Kohli, who declined to specify which cloud layer partner would be involved in the VMO2 deployment. 

And with brownfield deployments, the variety of configurations is expanding. Kohli noted that Mavenir has already worked on a standalone 5G Open RAN deployment with Dish Network and a 4G-only deployment with Triangle Communications in the US, but that for most brownfield deployments, the starting point will be non-standalone (NSA) 5G, so the bar is higher. “We’ve now reached a point where the maturity of the NSA stack means it can be deployed and can meet operator requirements, and there are others that will do the same thing: Go with a small-scale rollout to start and then ramp up if it’s proven to work. This will be the year when we prove ourselves in a live environment and prove we can do better than existing vendors and with open interfaces… and it’s all cloud native and you will have the same set of people working across the board. Of course there are application-specific details, but the operational aspects will become easier for the operators,” he explained.  

And what about network management tools? Are there any early plans to explore the potential use of RAN intelligent controller (RIC) capabilities? 

Geary says VMO2 will work with Mavenir to integrate the new systems with the operator’s existing back-office IT systems and explore how systems such as a RIC might play a role in the future. “You’ve touched upon some of the more challenging aspects for a brownfield operator there and we’re cognisant of those… We have learned from our previous tests and trials about the physical aspects of a deployment of this sort and the interaction into our management systems… You don’t want to take things too rapidly in terms of jumping all the way to that longer-term vision with intelligent controllers and optimising everything to the nth degree. We’re certainly interested in RIC and we’ve had a lot of conversations about it, and can see the long-term potential benefit of opening up those layers of the software and essentially applying smart algorithms to optimise the RAN, but we don't think we need that just yet.”

So what is VMO2 hoping for from this deployment? Is this the ultimate test to see if Open RAN is worth deploying more broadly? That’s part of it, but it’s also part of a broader network architecture transformation, noted Geary. 

“We are building critical mass for this new way of building networks because it’s not just the RAN that’s going through this transformation towards much more virtualised and open interfaces, but the RAN is an important area where you want to bring innovation and new ways of thinking to help push forward. This option gives us the flexibility we seek to evolve our network,” he explained.

But it also needs to be as good as what VMO2 can achieve with the experienced, tried-and-tested RAN systems from Nokia and Ericsson – the operator can’t take a step backwards just to check out Open RAN.

Mavenir’s Kohli is adamant that VMO2 will not be “compromised on quality, spectral efficiency and coverage… Open RAN brings open interfaces, but there’s no reason why this can’t equal or be better than legacy [RAN systems].”

Geary added: “Those are table stakes, particularly for a brownfield operator, on performance and spectral efficiency and we’re working closely on agreeing a software-feature roadmap with Mavenir to ensure we get what we need on the journey of this particular roadmap.” 

And then there’s security, which is also of key importance. “We have to operate a secure network for our customers. Because of the layers [in the Open RAN architecture] and the ability to get a view on what's happening on all the individual layers, that deeper and broader visibility means you see down to the code level. And as everything is moving towards software and a more standardised approach, such as this one represents… any necessary security patches or fixes may actually be quicker to [develop and] deploy because you’re leveraging a wider ecosystem than in the older RAN way of doing things, where it’s more of a black box. There are also some very large Open RAN deployments worldwide, which gives us more confidence. There are some networks out there with hundreds of thousands of sites in other countries, and security will be equally important to all of those major operators in Japan, the US and Germany,” noted Geary. 

And as for the innovation part of the equation, so often referenced when Open RAN is discussed, Kohli claimed that open, multivendor deployments will enable faster innovation. “With proprietary technologies, companies are building their own ASICs, which takes two to three years, and at the end you get whatever you can do with the ASIC plus a small amount of flexibility on top. With an open architecture, we are enabling a [new] pace at which these things can be done – you’re not designing a chip, you’re writing a C++ program, and that means you can accelerate how you bring new algorithms for new innovation much faster into the market,” he said. 

“We have been catching up with the market as we have had to develop 4G and 5G together and catch up with where [the incumbent traditional vendors] are today and we are now reaching that point. But now we believe the pace at which things can be done will be accelerated and by working with other vendors, such as Cohere, you can show that on the same spectrum you can have double the spectral efficiency and show this really working… Then you can see Open RAN is not just about vendor diversity and open interfaces but it can accelerate innovation as well,” added Kohli.

- Ray Le Maistre, Editorial Director, TelecomTV