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Peter Cochrane's Uncommon Sense: Wi-Fi On The Fly
Wi-Fi is wireless but not normally 'on-the-move' mobile - expect that to change

This all began some months ago by a chance encounter in a hotel lobby in Florida. I was looking to see if there was a public Wi-Fi service available and picked up several signals but none of them turned out to be base stations providing service. This prompted me to discreetly walk around the area with my laptop in hand sniffing for signal sources. It turned out that three laptops were on air and transmitting without, I presume, their owners being aware. The restaurant staff were also using PDAs to take orders linked back to the cash register and kitchen area.

I later repeated this experiment on a couple of train journeys in the UK, as well as more hotel lobbies, coffee shops and other public places across Europe and South-East Asia. In fact everywhere I go I see more and more people working on laptops and, whenever I spot a cluster, I take a look-see.

With Wi-Fi now being built into almost all new laptops and some PDAs, perhaps I shouldn't be amazed that there is an increasing amount of radiation in the 2.5GHz (802.11) Wi-Fi band. But do these people know that they are transmitting? For the most part I think not.

Today I happen to be flying the Atlantic and there are numerous laptops up and running, and yes, someone has their Wi-Fi turned on. The aluminium and titanium cabin tube of this Boeing 777 is an ideal WLAN conduit and the 2.4Ghz signal is available end to end - even in the toilets. As far as I can detect no two people are connected or indeed working together. What is happening here?

I suspect we have people working in corporate and home environments where they have Wi-Fi facilities and they just plain forget to turn off the facility when they are on the road. Alternatively they have turned to this mode by accident and are not even aware that they are both radiating and open to cyber attack.

While I have been tempted to 'drop into someone's screen and leave them a warning note, I have so far refrained from doing so. It all seems reminiscent of noticing someone has a shirt/blouse button or trouser/skirt zip undone. Better to be more discreet perhaps?

Have I ever been at fault and made this error? Oh yes! Just a couple of times I have overlooked the icon top right of my screen declaring that I was on air and at risk from, and a potential risk to others. And I have to confess that on one of these occasions I was on board an aircraft - but only mid-flight!

It is oh so easily done when you are on the move, flitting between public and office space, wired and wireless operation. A combination of tiredness and overload is all it takes, just a momentary lapse in concentration. So is it at all that risky?

The real surprise to me is that almost without exception the machines I stumble across are only using 40bit encryption that can be cracked in minutes. Only a few have had 128bit encryption enabled that would take hours to break. So one big risk is plain old cyber-attack: if you are switched on and don't know it, you are potentially wide open.

The radiated energy from a Wi-Fi card is only around 0.1W, and very similar to the average for a mobile phone in the middle of a cell network. Like the mobile phone the prospects for 'lap damage' are about the same as that for brain damage - zip!

What of interference with other electronic systems? This is always a possibility but on the average unlikely to be a serious problem.

Trains in Japan already provide simultaneous mobile phone and Wi-Fi services so passengers can be productive as they travel. There's none of the Doppler Shift signal drop out as experienced with some trains and mobile phones in the EU, and no high speed isolation from the net just because you happen to be moving. Think about it: 2Mbps to a laptop at 200kmph is more data than most can get to their static home.

The good or bad news - depending on your perspective and habits - is that several airlines are planning Wi-Fi services for their airborne passengers on continental and intercontinental routes. So soon it will be possible to access the net at near Mach 1.

Anyone who flies regularly will be acquainted with the failure of the seat back phone services that charge $2.50 per minute or more. Not surprising that at that price it is very rare to see anyone using these services. They have been a mitigated commercial failure.

Hopefully the pricing of Wi-Fi services will fall more in line with those in hotels where you can use all you need for a flat fee of $9.00 - or sometimes for free for those booking a room.

Does this mean we will also be allowed to use our mobile phones on board mid-flight? There is no reason why not, except for the fact that the terrestrial network of cells will most likely find it difficult to cope with the hand off cell to cell at speeds in excess of 700kmph. Satellite operation would overcome this limitation and voice over IP is another option we may be able to exercise. Either way it looks as though we are all going to be immersed in more airborne RF.

This column was typed on AA173 flying LGW UK to RDU US after sniffing out more Wi-Fi signals than I would have expected. It was edited over coffee two hours after landing and despatched to via a 54Mbps domestic Wi-Fi link connected to a cable modem in North Carolina. And in this location I can see six Wi-Fi signals, four of which have no encryption and are totally insecure!