http://www.presence-pc.com/tests/TGV-Internet-22741/2/
Actually, you can't use plain 3G because bandwidth cannot cope with all the passengers, and also because doppler would kill the link too often, just like for voice. and once you're dealing with satellites, you need smart caching proxies otherwise the latency is unbearable for savvy users.
In the end, it's even more complicated than putting the web in an airplane (well, save the final qualification process of the likes of FAA). The satellite antennas will get the equivalent of a lightning from the catenary 20 times a day, and no plane has to deal with tunnels... Pierre
Of course, masts are not right next to the tracks, and you could use gps to guess about the doppler (using a geo db of all antennas next to the track). But in the end, satellite is the less unmanageable option... Pierre
