Undersea 3G: British carriers EE and Vodafone strike deal for Channel Tunnel services

The British carriers EE and Vodafone(s vod) have signed a 10-year agreement with the operators of the Channel Tunnel, the 50-kilometer (31-mile) underwater tunnel that links the UK with France, to provide mobile services there.

The deal with Eurotunnel covers the North Running Tunnel, going from the UK to France. French carriers Bouygues Telecom, Orange and SFR struck a similar arrangement covering the South Running Tunnel in 2012, just before the London Olympics.

Echoing that deal, EE and Vodafone said that from March this year they will offer 2G and 3G services to passengers of both high-speed Eurostar passenger trains and Le Shuttle, the rail-bound shuttle service for cars. Both companies said they also intended to offer 4G services in future.

The carriers said they had managed to install the necessary equipment without any disruption to rail traffic, and the quality of calls 100 meters (328 feet) underwater would be as good as above ground. According to an EE spokesman, data speeds will reach 3-5Mbps on 3G and around 12-15Mbps on 4G.

The technology provider is Axell Wireless, with its distributed antenna system (DAS). Similar to the South Running Tunnel deployment, the key here is “leaky feeder” technology, i.e. a long cable acting as an antenna with the assistance of repeaters, hooked up via radio-over-fiber to the carriers’ base stations.

This article was updated at 4am PT to add further technical details.