more info here on how it works......

http://www.gnermobileoffice.co.uk/GN.../howdoesitwork


Certain GNER trains will have special Wi-Fi equipment, including a satellite dish, installed in order to provide you with Internet access. As trains travels over the landscape, this equipment will access a combination of available networks to communicate to the outside world. It will 'talk' to satellites, digital TV connections and mobile stations. Using these networks we will be able to provide you with a link that is always live.

The communication technology we are trialling allows data communication over these multiple links to increase the bandwidth and availability of the system. You will experience approximately the same kind of quality as with a DSL connection though the connection speed will vary based on obstacles along the railway track and the amount of coverage offered for the different networks used. For example, when the train passes through a tunnel, 4-6 cellular phone links are used in parallel to maintain the Internet connection, and even if the speed decreases temporarily, the connection will entirely not drop. This means that your connection speed will vary during the trip. You will access our internet connection by using your own Wi-Fi enabled laptop to link in to the on train server, using wireless 802.11b network technology.