• BT’s Chief Architect Neil McRae can’t see Open RAN lowering mobile network costs
• But he says Open RAN will definitely play a role in BT’s networks in the future
• Small cell and neutral host deployments are primary focus for BT currently
• Various elements and models already being analyzed, with RAN Intelligent Controller (RIC) systems featuring in some
• Companies such as Nokia, Mavenir and Accelleran are involved

Open RAN will be part of BT’s future network rollouts but the benefits it brings will be functional and operational rather than directly financial via lower capex, the UK national operator’s Chief Architect Neil McRae told industry media and analysts during a briefing in London this week. 

Keen to overturn the perception that BT is anti-Open RAN, McRae noted the telco has been exploring the potential of open mobile network architectures and elements for some time at its R&D facilities and is ramping up its Open RAN activities, with plans to set up a dedicated lab at some point in the near future.

But he also made it clear that there’s a long way to go before Open RAN becomes any part of BT’s production network and that he is skeptical about some of the potential claims being made for the architecture, especially those related to costs. 

“One of the big myths right now and for the foreseeable future is that Open RAN is going to save us money. I look at that with a lot of skepticism because I know how to write open source code and all the effort that requires, and when you look at some of the CPU and infrastructure you need, I know how much Intel sells it for and I know how much the other five guys who make layer one chips cost... you added together and you think, well, that doesn't really work – it's really simple math. There is nothing complex about this,” says McRae, who talks of a “cadre of companies that believe there are cost savings to be had with Open RAN, but a lot needs to be addressed before that can happen” as the whole total cost of ownership (TCO) of a network needs to be considered and not just the RAN infrastructure. 

McRae didn’t elaborate on the “cadre,” but he appears to be talking of his European telco peers – Deutsche Telekom, Orange, TIM, Telefónica and Vodafone – which are the co-signatories to an Open RAN MoU document and which have jointly issued an Open RAN tech wish list for the tech developer community. (See Open RAN MoU operators publish their tech wish list.)

Certainly those operators have aspirations related to lower comparative capex and opex for their planned Open RAN deployments and are working hard to find ways to reduce the costs of building and running a network. But as everyone in the market realizes, it’s such early days for Open RAN that no-one yet knows the total costs involved. But, understandably, that’s what many want to know more about, which makes it no surprise, then, that TCO was identified as the most important area of focus for the Open RAN community by those voting in the recent Open RAN Summit attendees poll. (See Open RAN community needs to focus on TCO models, RIC development: Poll results.)

McRae, pragmatist that he is, doesn’t buy into the lower cost argument based on the cost analysis he sees every day: So right now that spells good news for BT's two main 5G network infrastructure suppliers, Ericsson and Nokia, though there's little doubt they'll be under pressure to play ball as and when Open RAN has something McRae feels he can put to good use (and Nokia, to be fair, has been banging the Open RAN support drum for a while already).

And McRae is also clear that he's certainly interested in what Open RAN has to offer – though he's quick to point out its current limitations.

“Open RAN is in its early stages... and having seen the pace it has moved during the past two years, it's insane how quickly things are developing. But it's still got some big hurdles to overcome” related to performance and capability, explained McRae. “Could we build the network we have today in the UK, not just our network but other networks, purely with Open RAN. Right now, the answer to that is that we absolutely couldn’t. Could that be the future? Absolutely it could, and that's where we're engaged... Open RAN will absolutely play a significant [role and be] part of our network. We're running to RFIs [requests for information] right now, one focused around small cells and one focused around neutral host, and we believe that, today, Open RAN is very well placed for those two applications... We’re starting to look at how we augment our macro layer with small cells,” noted the BT man, adding that dense urban areas such as shopping centres could benefit from a neutral host infrastructure that multiple operators could use, with the open, software-oriented nature of Open RAN systems making that resource sharing easier to develop.  

And BT is already putting some Open RAN-based tech through its paces: McRae says there’s a small cell field trial underway in Leeds, and that BT has been engaging in small cell tests with Mavenir as well as Ericsson, Nokia and Huawei in recent times. 

And he’s also keen on the service and application innovation that an Open RAN architecture can offer.

“Could Open RAN introduce new suppliers and new vendors and create more competition and create more innovation? For sure. And it's that innovation which still excites us the most. Our ability to provide more exciting services to customers is what we are really focused on. And the second aspect of that is ‘network-ification’ – this is how we are bringing the network into places that network has never existed before, into healthcare, into stadiums, into multi-storey car parks, into flying drones... We are trying to bring the network to that space and we believe that Open RAN will allow us to bring the network to more places.”

And at the end of the day, whether BT deploys any technology or not simply depends on whether it’s useful and economic, and that goes for any open or proprietary technology. “We will use any technology if it allows our customers to get a better experience or a better service, and we can make money out of it,” said McRae. “Ideally, it'd be an open technology,” he added, but if it was proprietary tech that enabled a great customer service and experience and had strong business potential, “then we'll take a look at it. I think every company has to be open minded to every piece of technology,” noted the BT man. 

Where McRae thinks BT can benefit is by sourcing and developing the applications that could run on an Open RAN architecture and in particular the xApps that can run on a Near Real-Time RAN Intelligent Controller (RIC), an element that’s generating a lot of buzz in the industry right now. (See RIC at the heart of the Open RAN action.)

And BT is quite active with RIC developers just now – McRae says BT has a trial underway with Nokia, while Paul Crane, the operator’s Networks Research Director, says a trial is also underway with Antwerp, Belgium-based startup Accelleran, while BT is also active in the Telecom Infra Project (TIP) subgroup called RIA (RAN Intelligence and Automation). (See Accelleran adds 5G to its Open RAN mix.)

Crane says BT is busy developing some of its own xApps currently, while McRae believes BT can differentiate itself from others by “bringing our own capabilities to it... we have a huge data science team and we have more patents in AI than any other company in the UK,” says the Chief Architect.

So, Open RAN developments are alive and well in BT just now, with some specific use cases the operator wants to develop – just don’t ask about how much less it could save by building a nationwide Open RAN architecture...

- Ray Le Maistre, Editorial Director, TelecomTV