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Enemies dig in for WiMAX-on-cell phone trench war

Can standards committee redeem its reputation?

As far as Intel is concerned, that's easy: laptop computing must be able to pick up the Internet anywhere. The WiMax dream is to have a system that does everything Centrino WiFi does today, without all the inherent problems of a licence-exempt wireless. WiMax won't be something any heating engineer or kindergarten supervisor or second viola player or recycling operative can buy off the shelf and stick up on a pole, creating neighbourhoods with 20 different transmitters all on Channel 6.

In the UK, the comms regulator, Ofcom, has already announced that it expects to make a bit of money auctioning off this "limited and valuable" resource to the WiMax operators. It will be a managed spectrum.

The problem is that Intel's requirements are not the requirements of the rest of the market. Intel provides comms for laptop computers. It's easy to see that a technology that suits a laptop PC user, will be no good at all for the mobile phone user; just look (for example) at the size of the PC display! - something that big and power hungry will never be used on a mobile phone.

And WiMax technology, today, is big and power hungry. It's all very well saying, as committee members do, that the problem will be solved, but the mobile phone market can't wait forever. And they have an alternative: the femtocell.

The problem the mobile phone world is facing is a big one: it needs more bandwidth, but it can't afford to provide it with big cellular masts.

The cost of putting up UMTS cells is huge, and fraught with bureaucratic obstacles, as anxious neighbourhoods contest the erection of the masts on the grounds of possible health issues, or the effect on property values.

But there's the extra problem of just how many users you can support on a single mast; and it was always a problem which engineers knew they'd have to face, when the UMTS standards body decided to pick the 2.1 GHz frequency. It had many advantages, but the serious drawback of 2.1 GHz is that it's really not good at going through brick walls. In-building penetration is a real issue, and there's only one fool-proof solution to the problem: put the masts inside the buildings.

Femtocells are wireless access points. The only difference between them and ordinary WiFi access points, is that they transmit on mobile phone frequencies, and are licensed to mobile phone operators. Otherwise, they are high-speed wireless data in the home (or the office) for the user of the householder alone.

If you were Vodafone, and had a real problem in extending your access from current 3G levels, and you were told "You can use WiFi, or WiMax, or WCDMA femtocells" you would almost certainly take WiMax seriously, because of the option of owning the licence. You'd take WiFi seriously, if only because there are already a lot of mobile phones which can switch from UMTS to WiFi automatically; but ultimately, you'd really want to go for a solution that you can install in 2007, and which you'd own. And that's the femtocell.

WiFi is not as power hungry as WiMax will be; but even there, a WiFi smartphone runs a third as long on a single charge, as it does if you turn WiFi off and stick to standard cellular. A WiMax phone, built in 2007 (if there wre such a thing) would probably last half the time the WiFi phone did - maybe less. And it would be -crucially - no better at moving from one cell to the next than the WiFi phone is ... which is to say, crap at it.

Intel has made it clear that it doesn't think the phone market is going to buy WiMax. It put its money where its heart was, not where the mouth was. It owned one of the biggest, most powerful mobile phone processor designs in XScale; and it sold X-Scale off, abandoning all ambitions to own a share of the market.

Intel can make all the excuses it likes for that; bottom line is that it lacked faith in that technology for phones, and that if it had had faith, it would never have been content to let someone else reap the rewards of that faith. It baled out.

If and when the cellular hand-off problem is solved, and operators can see a network smoothly and swiftly allowing high-speed data users to drive a 140 kmph car while downloading large files reliably, onto a pocket-sized terminal that carries a full day's battery charge, they will be interested.

And at that point, they'll start looking at how many WiMax cells they can install, how man they need per square mile, what it costs per user, and how many users extra it will give them in the first five years.

Against that, they have to look at the number of households that already have broadband. Each of those households can be converted into a femtocell for around $50, with a payback period measured in months, maybe even weeks. They'll be encouraged to use their UMTS phone as the universal data gateway if they have that, meaning more paid-for traffic on their public masts. And the handsets will be very, very much cheaper and simpler to design, operate and fix, than multiple-radio devices which have to do WCDMA, GSM, WiFi, Bluetooth and WiMax.

Can the 802.20 committee find a way of avoiding that morass, and getting a short-cut to a UMA style solution that works for mobile phones as well as for PC laptops?

In another decade, we'll know what happened. Right now, the only thing that's certain is that Intel doesn't seem to think so. ®

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