A British company claims to have conducted the world's first trials of a high-speed wireless network powered by a bi-directional satellite link on board a moving train.
Train Wi-Fi isn't new, as companies such as Pointshot and Icomera have been trialling systems for several months. But 21Net insists its technology is a significant breakthrough because it gives a faster uplink to the Internet than its rivals, who are dependent on GPRS or 3G to sent data from the train to the Internet.
Henry Hyde-Thomson, chairman of 21Net, told ZDNet UK on Wednesday that his company's system will support business applications such as video conferencing and the sending of large emails, and is comparable to ADSL.
"We've built a system offering multi-megabyte data rates in both directions on a train moving over 300 kilometres per hour," Hyde-Thomson said.
Trials took place in late June and late July at undisclosed locations in Europe. Hyde-Thomson said that during one trial four laptops were able to each get a connection speed of 700Kbps simultaneously.
21Net's near-symmetrical broadband link contrasts favourably with a 3G connection, which typically give a maximum uplink speed of 64Kbps. One analyst, though, has already speculated that 21Net's service could be more expensive to operate than one using a mobile network uplink.
Tunnels are a big problem for any company trying to supply a moving train with a high-speed connection.
Hyde-Thomson said users won't expect to be able to get an Internet connection at all times during their journey: "You don't expect to get an Internet connection in the dark of a tunnel any more than you'd expect to use your mobile."
According to Hyde-Thomson, the satellite connection can be restored within a couple of seconds once a train emerges from a tunnel. He added that users will maintain their link to the local server onboard the train, and that Web applications won't crash.
Broadreach told ZDNet UK last month that its system uses an "intelligent spoofing" technique to cope with tunnels, and 21Net's solution is thought to be similar.
Several UK train companies, including GNER and Virgin, are already showing firm interest in Wi-Fi. 21Net, though, says it is not focusing on British market and is instead hoping to win business from Continental operators.