Incorporating new open RAN architecture into legacy networks isn’t an easy task, and operators like BT and Orange are looking at smaller scale deployments before macro networks.
BT Managing Director and Chief Architect Neil McRae and Orange Global Radio Innovation Director Olivier Simon are among experts that will delve into the topic of legacy networks and open RAN this Thursday during the FierceWireless Open RAN Summit, a free virtual event.
Before deciding on wide-scale implementations, operators like BT and Orange are taking more targeted approaches to open RAN. They’re zeroing in on applications, like private networks and pilots, that in part have less demanding performance requirements and can provide learnings down the line.
Although the companies have different timelines and emphases for integrating open RAN in legacy networks, both expressed the sentiment that the shift is more a matter of when than if. However, they don’t equate open RAN with ditching Ericsson, Nokia and other larger vendors for only newer or challenger vendors, which have cropped up and helped champion open RAN.
For Orange, which operates in 26 countries, the carrier has committed to start deploying O-RAN Alliance-compliant base stations starting in 2025.
Simon, who heads up radio research at Orange Group and is on the executive committee for the O-RAN Alliance, told Fierce that’s when the technology will be mature enough for the most demanding use-cases - particularly in dense urban environments that use multiple frequency bands and require technology like Massive MIMO. Massive MIMO arrays already have 64 or 128 active antennas, and it's a technology that's been pegged by some as key for mid-band 5G.
“The current pure open RAN solution that we have today, we believe, are not mature enough to cover such demanding use cases,” he said.
Before that, Orange is starting with easier scenarios such as rural deployments, indoor and private networks, and then will “progressively ramp up to the rest of the network.”
Private networks don’t usually need Massive MIMO (Simon said only around 5% of private network deployments – like a very large campus or private venue) and often use 1-2 frequencies instead of the 5-7 different bands used in public networks. They can be supported by smaller 2T2R or 4T4R antennas.
“For this type of solution, the requirements in terms of performance of chipsets and integration are less demanding and we think we can address that quickly,” he said. Orange is already working on some lab and trial activities on the three use cases for open RAN, to be ready to go commercial in 2022 or 2023, according to Simon.
“The 2025 mark is for us is kind of the time for us that we think open RAN will start to dominate the deployment,” he said, in terms of macro.
In a standalone 5G pilot program in France, working with vendors like Mavenir, Casa and others, Simon said the goal is to not only test the migration but to verify the promise of open RAN, such as less time to market and more dynamic operations.
As a greenfield deployment, an objective is to make it easy and go as fast as possible on those promises – look at the results and see how much the operator gains.
“With that we’ll be able to properly plan the migration of the brownfield operation.”
BT’s Neil McRae says the operator isn’t less enthusiastic about open RAN than others but has some unique requirements and wants to implement the best and most economical solutions – be that with open RAN or another approach.
For BT, owner of mobile brand EE in the U.K., there’s less of an emphasis for open RAN in the macro network than there is for small cells, private networks, and neutral host environments.
“We think the architecture of the network and open RAN’s strengths right now are in those areas,” McRae said in an interview with Fierce. BT is halfway through a significant piece of work to select more open RAN partners for the next steps in 4G and 5G private networks, according to McRae. He cited the start of huge demand in the U.K. for customers that want service providers to build the network but also deliver products for video analytics and services for efficiency in industries like manufacturing.
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“We think open RAN could play a really big part in delivering those solutions in a cost-effective way” for Industry 4.0. “We’re probably more focused on that because we see that as this new opportunity, than overly focused about our macro network where we’re mid-way through deployments.”
McRae called out shipping ports (BT helped build a private 5G network for Belfast Harbor) and airports, both industries feeling different impacts from Covid, as prime use cases. Private 4G or 5G networks are typically greenfield implementations, which he acknowledged could be easier than changing up the macro network with open RAN.
There’s also work being done to try and incorporate key feature functions for emergency services that would need to be tailored in open RAN. For example, in situations like a traffic accident or major incident, responders need capabilities like group push-to-talk, which require quality of service and prioritization parameters that aren't always front of mind in a typical RAN scenario.
“Open RAN gives us the ability to offer them and offer them perhaps in a better and more controlled way,” McRae said. "If I think of the RIC [RAN Intelligent Controller], that will give us an xApp that really allows us to build on the emergency services feature functionality that we need.”
Still, McRae emphasized that open RAN isn’t the only way to go.
“Ultimately, we’re not religious about this direction, we want the best solution that allows us to deliver the services our customers want in the most economical way,” he said.
Nokia’s O-RAN pause
Nokia itself caused a stir in the O-RAN community last week when it confirmed pausing technical work after three contributing members were restricted by the U.S., but both McRae and Simon feel confident the issue will be resolved.
“I’m 100% convinced we’ll work it out. But there are political challenges that we all need to work together to resolve,” McRae said, noting he couldn’t speak for Nokia, but that includes vendors, operators, governments and other stakeholders. “It’s no secret we’re swapping out Huawei here in the U.K, and we want to make sure whatever direction we move in, it has a long-term sustainable solution. We don’t want to do anything that may have some doubts, and I suspect that’s what Nokia are convinced about because you don’t want to invest in something that isn’t able to generate a return.”
The Finnish vendor is a major contributor to the Alliance, and he believes open RAN is stronger with Nokia than without.
Simon said similar issues arose within bodies like 3GPP and ETSI when Huawei was on the U.S. entity list, and rule changes will be needed to ensure companies can remain members but others are able to protect their businesses and comply with U.S. regulations.
In line with the O-RAN Alliance stance, Simon said “we are currently working on this adaptation, and we are confident that Nokia will kind of be able to come back to the contribution well protected and well in-compliance with U.S. regulation in the coming weeks.”
Open RAN 'take it as a must'
BT is targeting nationwide 5G coverage in the U.K. by 2028 and chose Ericsson as a RAN vendor, while also under a government mandate to remove existing Huawei gear.
In the macro networks, McRae expects open RAN “to really generate huge momentum” in the next generation of radio technology (but doesn’t want to call it 6G, noting a long runway still to go to deliver on 5G).
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Orange’s Simon thinks operators need to get going on open RAN in the next several years.
“The move to open RAN is probably the most important architectural move since the beginning of the deployment of 2G,” said Simon, noting more continuity between transitions of earlier generations including up to 5G.
“With open RAN we have a disruptive evolution,” he said, not just with open interfaces but also thanks to separation of software from hardware via virtualization.
Simon’s advice to operators considering open RAN in a brownfield environment is to take it seriously, but don’t assume it’s easy.
“But take it as a must,” he said. “Because I’m quite sure that the operator which will not use the next 3,4,5 years to make this change will be in a difficult situation from a competitive perspective.”