Why Tube tunnels don’t have WiFi (Wired)

Want a quick digital detox? In London, all you need to do is take the Tube. But, from next year, Transport for London (TfL) says it will roll out 4G coverage on the Underground. It’s a start, but London is still some way behind its big city rivals.

That 4G coverage will join the Tube’s Wi-Fi network, which, since 2012, has let people get online while travelling through London’s myriad of Underground stations. Unlike the metro networks in many other major cities around the world though, in London you can browse only while you’re at a station. So if you’re sitting on the Tube and have that all-important email to send, you will be off-the-grid while you’re in the tunnel; as soon as your train pulls in, it’s a mad dash to find the network and connect, in the hope your train doesn’t pull out just as you hit the ‘send’ button.

But why does London have much worse connectivity than most other public transport systems below ground? And why is there zero phone connectivity? Take Moscow’s Metro, where both Wi-Fi and mobile phone network have been available since 2014. New York has had fast and reliable Wi-Fi since 2017 – admittedly only at stations, but to make up for that the Metro system also has 4G, while the carriages at least have Bluetooth beacons that provide arrival times to customers using the MYmta app. Rome has excellent Wi-Fi service on most of its lines. Tokyo, Barcelona, Hong Kong and Melbourne all provide connectivity in tunnels. In South Korea, Seoul has even been trialing connectivity using the mmWave spectrum, which is expected to be a key part of next-generation 5G networks.

London’s failure to connect has multiple causes. First is cost.

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