Online underground

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Media captionRory Cellan-Jones gets a sneak preview of the Tube's new wi-fi service

For a few minutes this morning, I watched Jeremy Hunt giving evidence at the Leveson inquiry, then started watching last night's episode of The Apprentice via the BBC iPlayer. Nothing unusual in that, except that I was doing it deep underground on a London tube platform.

I was being given a sneak preview of the free wi-fi service which is going to be made available on London's Underground system during the Olympics. Virgin Media is hooking up around 80 stations to its fibre network, and then installing access points at various points - on escalators, on platforms, in corridors.

Where the service will not be available is on the trains - except when they are standing at a platform. Transport for London says it would be extremely costly to wire up a tunnel network, some of which dates back to Victorian times. And it seems there's concern too about the reaction of passengers who may still see the tube as a last refuge from the always-on world above ground.

So how does the service work? I logged on via my phone, entered my email address, and then I was online, first on an escalator heading down, then on a tube platform. I checked up on news, sent a historic tweet and then started watching The Apprentice. It seemed very fast, with the video streaming without any buffering. Rather better, in fact, than I get on my home broadband. And a quick speedtest carried out on a TFL employee's tablet computer showed download speeds of over 25Mbps.

Now of course that will change when I'm not the only one using it. And the whole service will be a fascinating experiment in the demand for greater connectivity. Will people feel it's a waste of time because they only have a couple of minutes before they get on a train and lose the signal? Or will they all be rushing to check travel information, update their social networking status, and send emails?

As someone who is addicted to being online, I think this will prove rather popular. And then there will be pressure to make the service available on the trains as well. So, if you're someone who goes underground to get away from it all, make the most of it.