A looming 5G ban on Huawei risked turning the UK market for radio access networks into a Nordic duopoly. Three UK, the smallest of the four mobile networks, quickly chose Sweden's Ericsson as its second 5G supplier after the government published its decision on the controversial Chinese vendor. BT, the incumbent, has awarded deals to both Ericsson and Finland's Nokia. O2, owned by Spain's Telefónica, already relied almost entirely on the Nordic firms.

But Vodafone has now come forward with a commitment to use open RAN, an emerging technology, at about 2,600 mobile masts currently served by Huawei. The figure equals about 35% of the Chinese vendor's estate within Vodafone's network, according to a spokesperson for the UK service provider, who spoke with Light Reading after the Financial Times first reported on the move (subscription required). While vendor selection is in the early stages, Vodafone hopes to kick off a major deployment by 2022.

Figure 1: Vodafone's headquarters in the UK town of Newbury.

Other than their own wariness, there is nothing to prevent Ericsson and Nokia from supplying open RAN products. Yet Vodafone is likely to avoid them. It is interested in open RAN largely because that could boost supplier diversity in a market where there are currently few viable alternatives to the giant kit vendors. Trials in various geographies have already been carried out with Mavenir and Parallel Wireless, two US developers of open RAN software.

The technology promises a new set of interfaces that would allow service providers to mix and match different suppliers in the radio access network (RAN). Many operators have complained that today's systems force them to rely on one company for all the RAN technologies at a particular site. Thanks to other "virtualization" advances, they would be able to run open RAN software on commoditized, general-purpose equipment.

Clearing the hurdles

Yet open RAN still needs to clear some major hurdles. Above all, its ecosystem is still relatively undeveloped. On the hardware side, it lacks the manufacturing capability of the traditional kit vendors. Until it scales up, it may struggle to meet telco demands or be as economical as mainstream technologies, now used to serve billions of mobile customers worldwide.

Another concern is that open RAN still falls short in more challenging deployment scenarios. The 2,600 sites that Vodafone has promised to overhaul lie in western rural parts of the UK. Using open RAN to support 5G services in more densely populated communities would be difficult. Vodafone's ultimate goal, however, is to ensure that open RAN can work anywhere, across all the different generations of mobile technology.

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Vodafone is under pressure to comply with a government deadline for the removal of all Huawei's 5G products by the end of 2027. This would be fairly straightforward with mainstream technologies from Ericsson and Nokia. Using open RAN as a substitute, even across only 35% of these sites in rural areas, may be tough.

The payoff would be a much broader choice of vendors in future. That might even include UK firms, which have not featured in the network equipment sector since the days of Marconi, eventually bought by Ericsson in 2006. Lime Microsystems, based in the UK town of Guildford, is one player that might benefit. It is already supplying 4G equipment to a Vodafone site in Wales that was supposed to be used during this year's Royal Welsh Show, an agricultural event canceled in 2020 because of the coronavirus pandemic.

Government interest

The government has become an enthusiastic advocate of open RAN, seemingly convinced it is the best way to foment competition. "The chances of creating another Nokia in the UK are close to zero," said Ian Livingston, the head of a UK taskforce set up to explore alternatives to Ericsson and Nokia, and a former BT CEO, during a parliamentary committee last week. Vodafone has previously urged authorities to back research-and-development initiatives that might spur the open RAN ecosystem.

Livingston is under no illusion about the complexities that surround open RAN. "As you move to a diversity of suppliers, you don't have a single entity doing systems integration and it becomes more difficult," he said last week. "There are challenges beyond the obvious ones."

Vodafone had always seemed the likeliest of the UK's four mobile networks to use open RAN as a Huawei substitute. It already relies heavily on Ericsson as a kit vendor and has been phasing out Nokia. It does not view Samsung as an option because the South Korean firm lacks a 2G offer, which remains important to Vodafone's machine-to-machine connectivity business. Vodafone has also been notably active within the Telecom Infra Project, a Facebook-led initiative set up to aid the development of open RAN and other emerging network technologies.

Japan's Rakuten and America's Dish have already made significant open RAN commitments. Yet both those companies are building their networks from scratch as greenfield players. With today's update, Vodafone is taking a bigger step into the unknown than any other brownfield telco in a developed market.

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— Iain Morris, International Editor, Light Reading