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T T-Mobile "WiMAX" railway hotspot link - what's the real story?

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.

Nomad has yet to install complete track-side coverage. It's fixing base-stations to railway stations owned by Southern to avoid the need to pay Network Rail, which owns the lines and most of the land adjacent to them. Wallbridge reckons the company will need to install 60-odd base-stations along the route, of which 37 are now in place.

Wallbridge claims users will get access speeds of up to 256Kbps over the link, the limiting factor being the 1Mbps commercial ADSL connections between the base-stations and the internet. There are four GPRS modems in each carriage as a back-up, a technique used by other providers, such as Broadreach and Sweden's Icomera, the company behind GNER's East Coast Line Wi-Fi service.

T-Mobile's role in the Southern/Nomad operation is to provide billing and promotional services, and to sell access time. None of the companies were willing to explain how costs and revenue are shared, though that's the norm in this emerging market. In any case, revenue sharing isn't an issue for the moment: the service is being offered free of charge until June, when the network installation is scheduled to have been completed. Then, users will have to pay £5 for an hour's access, sufficient for the 55-minute journey from London to Brighton.

Performance

How well does the Brighton Express Wi-Fi service perform? To be fair, we travelled only part of the way, to Croydon, and in a carriage packed with notebook-toting journalists all eager to sample the joys of supposedly high-speed internet access. While we were able to access El Reg, and our email servers, trying to stream the most recent Hitch-hikers' Guide to the Galaxy trailer failed after the first few minutes. On the basis of this one, admittedly worse-case scenario trial, we didn't get the promised "genuine broadband experience".

Glancing at the carriages wireless control box, the Train Control Unit, we noticed how often the WiMAX connection LED was off, in turn revealing how much the four GPRS modems were needed to deliver bandwidth during the journey. The situation - and the bandwidth - should improve as Nomad adds the remaining 23 WiMAX base-stations along the line. Increasing the 6Mbps WiMAX bi-directional bandwidth used in the trial to the 32Mbps it claims the system is capable of delivering and widening the DSL backhaul pipe will help too.

Even so, T-Mobile has already had some very positive feedback from users of the trial service, it says, as has Southern Trains. Together they have done a good job with the carriage's signage to alert passengers to the presence of the service. Large signs at each door are complemented by window stickers at each table. The service is democratically offered to both First and Second Class passengers.

Adding up

The London-Brighton service has had around 135 users between 1 and 11 April. Adding a further 14 carriages to the one unit currently equipped with Wi-Fi, as Southern is already planning to do, will boost the usage figures, but it's clear it's going to take some time to recoup the costs. On average 12 people use the service each day. Assuming they pay £5 to do so, that's £60 a day. At that rate it will take over 15 years to pay for the WiMAX links and the single carriage's kit - assuming T-Mobile doesn't take its cut.

Last year, Broadreach surveyed 1600 UK rail passengers and found 78 per cent of business travellers are interested in using Wi-Fi on train journeys. A similar number said the provision of such services would persuade them to take trips by train rather than by car or plane.

More to the point, most of them are willing to pay up to £12 for the privilege, depending on the length of the journey, and that's a big motivation for TOCs to roll-out wireless internet technology. If they can stomach the up-front cost.

This story copyright  TheRegister®