Permanent phone reception is available on underground sections of London’s Tube network for the first time.
Passengers using the eastern half of the Jubilee line are able to connect their devices to a 4G signal from Tuesday, Transport for London (TfL) announced.
Travellers can make phone calls, send messages, browse websites and stream videos in ticket halls, station corridors and even when trains pass through tunnels.
The service, which has cost TfL £10 million to deliver, is available between Westminster and Canning Town.
Customers with EE, O2, Three and Vodafone devices – including virtual operators who use their services such as GiffGaff and Tesco Mobile – are able to connect to the signal.
This is in addition to free Wi-Fi which is available at many Tube stations, but cuts out in tunnels.
Mobile coverage on underground sections of the Tube has only previously been available in a short trial on the Waterloo and City line during summer 2017.
TfL will begin work to expand 4G access to cover platforms and tunnels across the entire Jubilee line by the end of 2020. It hopes to add coverage to other lines from next year.
Deputy mayor for transport Heidi Alexander said: “Poor mobile connectivity is a major barrier to growth so I’m delighted that Tube passengers on the eastern section of the Jubilee line will be able to enjoy 4G access.
“This milestone will enable Londoners and visitors to get online while travelling through tunnels and platforms, doing everything from watching videos and messaging friends to catching up on emails.”
TfL chief technology officer Shashi Verma said: “We are delighted to have delivered this pilot of 4G mobile signal on the eastern end of the Jubilee line.
“This has been very complex work to install the necessary equipment to allow our customers to be able to get phone reception within our tunnels while keeping the stations open and operational.
“We are now looking at extending the pilot to cover the entire Jubilee line by the end of the year, as well as award our wider concession to allow the whole Underground network to be connected in the future.”