Bluefi? Witooth? WiFi and Bluetooth are getting together

Earlier this week, Charles McLellan and I popped over to see wireless and network chip maker Broadcom, to film some 802.11n fun for Dialogue Box.
Written by Rupert Goodwins, Contributor

Earlier this week, Charles McLellan and I popped over to see wireless and network chip maker Broadcom, to film some 802.11n fun for Dialogue Box. You'll be able to see the results early next week: Broadcom is one of the more practically minded and sensible players in that market, and I think they said some eminently sane things about the standard.

As is usual, though, some of the best conversations came as the camera was being put away and we stood around just chatting. This got shamelessly nerdy, as I took every advantage to try and get up to speed on radio chip design and where it's going.

It's going in some interesting directions. Broadcom, like others in the market such as Cambridge Silicon Radio, are putting more and more features onto single chips; you can get 802.11g, Bluetooth and stereo FM in one device these days.

Perhaps most interesting is the way that these are almost purely digital now: the radio signal gets digitised as quickly as possible, with digital signal processing emulating most (in the case of the stereo FM component, all) of the normal radio functions that used to be done by analogue components.

Moore's Law doesn't apply to analogue chips, which are much more severely limited by physics, so if you go digital as soon as possible you get huge benefits in cost and performance. It does produce some apparently silly contrasts: I had a little AM/FM pocket radio as a kid which had six transistors in it. The equivalent digital radio chip will have several million - and will cost ten times less.

I asked my favourite question: what future developments in radio will get you most excited? There were meaningful glances - darn, things they wanted to say but couldn't! - but the considered response was still worth having. "Bluetooth and Wi-Fi...".

Now, these two standards were once very bad bedfellows. They both use the same frequencies and many of the same ideas, but interfered with each other something chronic - indeed, early devices could often only use one at a time. And you did need both - Wi-Fi for range and speed, Bluetooth for ease of connection and battery life.

Times have changed. Many years of work in making the standards co-exist mean they can now not only live in the same equipment but on the same chip and sharing the same antenna, while advances in technology and design mean it's no longer impossible to think of Wi-Fi as being too power-hungry to do Bluetoothian things.

And indeed, the next big revision of Bluetooth, due in the second half of 2008, will include the ability to set up high speed channels between two Bluetooth devices using Wi-Fi (or whatever). This neatly combines Bluetooth's superior ability to find and connect to its peers with 802.11's ability to actually do something useful with media data. If you've ever struggled to set up a Wi-Fi enabled consumer appliance like one of Reciva's wonderful Internet radios, and then connected to a Bluetooth headset with your mobile, you'll appreciate that. One doesn't expect you to enter hexadecimal...

It's even more intriguing to imagine what might happen if Bluetooth gets more net-centric and becomes routable over Wi-Fi. You've got a pal in Australia with an MP3 player? Wouldn't it be rather splendid to browse it from Amersham? Or be able to get at your home media files from a roving device over hotspots, as easily as you can listen to an iPod?

If handled well, this could be one of those convergences that creates whole new markets.

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