BAI plans to invest more than £1bn across the Connected London programme.
Three and EE have agreed to a deal to join the BAI Communications (BAI) network which will provide customers with access to 4G and 5G connectivity across the Tube.
The deal was awarded a 20-year concession with TFL to deliver mobile connectivity on the underground in June 2021, allowing customers to never lose coverage while they stream videos, make calls, or check travel information.
Every platform, tunnel and ticket hall across the Tube network is set to have mobile coverage by the end of 2024.
The Elizabeth line is on track for high-speed connectivity to go live next year across its platforms and tunnels.
BAI Communications UK CEO Billy D’Arcy said: “We’re pleased to welcome Three and EE as our launch partners and the first operators who will be transforming customer experience on the London Underground by enabling them to access seamless, 5G-ready connectivity.
“This is an important next step on the project’s journey which will allow passengers to move around the capital more smartly, safely, and securely.
“More broadly, the new backbone of connectivity will create a platform for innovation and allow London’s residents and businesses to harness smart city technology, helping to improve urban life and boost the economy.”
All mobile operators will be able to access London Underground WiFi and BAI’s neutral host mobile network.