You’ll soon be able to call to say you’re running late even if your Tube is stuck in a tunnel.
The Jubilee line is set to get full 4G mobile connectivity in tunnels between Westminster and Canning Town from March next year.
The service will also cover ticket halls and corridors at almost all stations in the section, with the exceptions of Waterloo and London Bridge which remain subject to final approval but should be added later in the year.
The trial will build on TfL's existing free WiFi service at more than 260 stations across the capital and, if successful, could see a contract to roll it out across the network awarded in the summer of 2020.
Mayor of London Sadiq Khan said: "This is a really important step for the millions of people who use the Tube each year.
"Introducing 4G and, in the future, 5G will help Londoners and visitors keep in touch and get the latest travel information while on the go."
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