On-train Wi-Fi gets satellite upgrade

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 send data from the train to the Internet.

Henry Hyde-Thomson, chairman of 21Net, said 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 300km 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."

Graeme Wearden writes for ZDNet UK