WiFi connection on the Underground will open up additional interactive advertising opportunities, such as augmented reality and QR codes, for brands that pay for media space in stations and on tube trains.
Connectivity is only available at platforms and in ticket halls, but train passengers will also be able to connect as their carriage rolls into stations.
The service will be free over the summer during the Olympics to all passengers but in the autumn, WiFi on the Underground will only be free to Virgin Media broadband and mobile customers or available via pay-as-you-go and other commercial models.
Passengers who are not Virgin Media customers will be able to use a free online portal to view live travel information using the network.
By the end of 2012, up to 120 Underground stations are expected be connected to free Wi-Fi via Virgin Media.