T-Mobile steams in with WiMAX, Wi-Fi train

The rail deal

Analysis European rail operators love Wi-Fi. They're keen on anything that encourages more businesspeople to take the train, and wireless networking is an attractive way to provide paying travellers with ad hoc connections to the internet and company networks. A journey's duration becomes productive work time, whether it's part of a daily commute or a longer trip.

Connecting a carriage to the internet is not a problem. Nor is sharing that connection among the passengers, many of whom travel with wireless-enabled laptops nowadays. The tricky part is providing sufficient bandwidth to let them all send and receive large emails, and to surf the web, at an acceptable speed. This is crucial - if it's too slow, they won't pay for it.

T-Mobile this week re-iterated its claim to be the first Wi-Fi hotspot provider to offer "genuine" broadband speeds on a UK train. It compares its offering to similar services run separately by train operators GNER and Virgin. Where they use satellite uplinks to provide connectivity when the train is moving, T-Mobile's service, installed on Southern Trains' Brighton Express by wireless specialist Nomad Digital, uses WiMAX, a would-be wireless standard touted for its ability to host high-bandwidth connections.

However, WiMAX - also known, more prosaically, as 802.16-2004 - is designed with the assumption that neither end of the connection is moving. So Nomad has had to do a little fiddling with the technology to get it to cope with a train moving at up to 100mph, tactfully calling its implementation "pre-standard". It also has to put its base-stations quite close together. Fixed WiMAX links are typically intended to operate over tens of miles - the 60 mile line from London to Brighton needs a base-station every mile or so, so the train's rooftop antenna is never much more than half that distance from the strongest signal.

Cheap as chips?

Nomad won't say how much the network is costing - "it's cheap, very cheap", said company Executive Chairman Nigel Wallbridge - but at around £5000 a base-station, and with 60 or so of them along the line, it's costing Nomad and Southern £300,000 just to put WiMAX alongside the track. Equipping each carriage with Wi-Fi access points, a WiMAX antenna, back-up GPRS modems and the router and other equipment needed to tie them altogether runs into tens of thousands of pounds.

And this is just one line - rolling out the service across the remaining 614km of track over which Southern's trains operate takes the price to over £2.2m.

That's one of the chief reasons why other Wi-Fi providers with their eye on the rail business have opted for satellite links - more expensive to install in the carriage, but more scalable as the number of trains equipped with Wi-Fi increase. One railway Wi-Fi specialist, Broadreach Networks, even stresses it will use any suitable technology to connect the carriage to the Internet, from 3G mobile to WiMAX, and even Wi-Fi access points sited in stations, based on the needs of a given roll-out. Broadreach is behind Virgin Trains' Wi-Fi service, currently being installed on the operators' Pendolino trains.

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