If you use the Tube to go shopping in the West End of London this Christmas, you should be in for a pleasant surprise, because some parts of central London’s underground railway network will have mobile coverage.
All of metro system’s tunnels and stations should be covered by early 2025, says Brendan O’Reilly, group chief technology officer of BAI Communications, the company that is building out a shared wholesale network that will works with all four of the UK’s network operators: BT’s EE, Three, Virgin Media O2 and Vodafone.
O’Reilly says this is a challenge, mainly because his team of 300 to 400 are only able to work for a few hours a night, between when the metro service closes after the last train runs and it re-opens for early commuters.
Of course, despite its name, most of London Underground’s trains run in the open air through the city’s suburbs where operators’ regular networks provide 4G or 5G wireless coverage.
Old technology
In many cities in the world, mobile services on metro trains has long been taken for granted. I first saw Stockholm schoolkids using their Nokia phones deep below the city while on the Tunnelbana 22 years ago. But Londoners, like me, have not been able to text, phone or use the internet from the Underground’s deep tunnels. This has not been down to Transport for London (TfL), which runs the transit network, not liking phone users – limited Wifi services have been available in TfL’s stations since 2012 – but because London’s metro network is the oldest in the world. The first Underground line was built in 1863 by the Metropolitan Railway – hence the word “metro” – and the deep-level lines – such as the Bakerloo, Central and Piccadilly lines – date back to the end of that century, and were built with tunnels just wide enough for trains to squeeze through.
BAI – originally called Broadcast Australia – got into underground mobile network business when it bought RFE, which ran the mobile coverage for Hong Kong’s Mass Transit Railway (MTR) metro from the transit network’s birth in 1979. Unlike the London Underground, the MTR was built with space for cables and antennas.
Today, BAI runs the mobile service on Toronto’s subway for the Toronto Transit Commission, is installing 5G networks for New York’s Metropolitan Transportation Authority (MTA) and on San Francisco’s Bay Area Rapid Transit (BART) system, and will provide coverage for the emergency services network that is being built by EE.
O’Reilly, who moved to BAI’s London office in 2021 after 11 years with O2, which was wholly owned by Telefónica at the time, understands shared networks. Ten years ago he led negotiations between O2 and Vodafone that resulted in an agreement to roll out shared UK networks for 2G, 3G and 4G.
BAI then “bid for Toronto” and took a majority stake in Transit Wireless, which is responsible for MTA’s coverage.
He tells me that mobile coverage on metro systems “makes good business sense, with long-term partners”, and adds that it is “a foundation layer for any smart city”.
Staying neutral
BAI has different business models in the various cities it has presence in. In Toronto, it works with Shaw Communications’ Freedom Mobile, while in London and New York it operates shared services for all operators. However, O’Reilly will not discuss BAI’s wholesale arrangements and how it splits the revenue from calls made underground.
“Each customer has a different set of needs,” says O’Reilly.
In New York, installation is difficult because its mass transit service runs 24 hours a day. But on the other hand, some lines have four tracks, so there’s space for installers to work while the trains run.
Frequently, metro systems have small data centres where operators can install their own equipment that are connected to leaky feeders (coaxial cables that radiate) and distributed antenna systems.
“We work with customers to get it right. What separates us is our complete neutrality,” O’Reilly says. “We really love long-term deals, and we’re keen to be a trusted partner.”
This is maybe in contrast, though O’Reilly didn’t say so, with some mobile operators’ deals with tower companies in some countries.
In London, BAI has been installing 5G cabling from day one, even though most network customers are still using 4G. “On the MTA and BART, we’re agreeing a 5G plan,” he says.
What O’Reilly likes seeing are seamless handovers as calls move from the open air, where they are on an operator’s network, and into tunnels, where BAI’s antennas take over. “It’s important calls don’t drop,” he says.
When BAI began the TfL contract in June 2021, the Jubilee line already had partial coverage, the result of an in-house project which BAI took over.
“But our own first stations should be live before the end of the year,” he says. “If you’re doing late Christmas shopping, as I do, you’ll be able to use it.”
