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Bluetooth: dead or alive?

Posted on 21 Nov 2002 at 15:36

It seems likely that 802.11 (in all its alphabetical forms) will co-exist with Bluetooth rather than compete with it, so the way forward is to integrate the two technologies into those devices that will move between the different areas.

Notebooks are the most obvious candidates, and we're already seeing notebooks that integrate both Bluetooth and 802.11. Sony and Toshiba released such laptops during 2002, although others are holding back, citing interference problems.

We know from our own experiments that using Bluetooth simultaneously does affect the bandwidth of the 802.11 connection, but not to a catastrophic effect. And according to Glenn Collinson at Bluetooth specialist CSR, things will get better in 2003. 'Early in the year you'll see notebooks where there's a hardware handshake between the two radios, so if you're transmitting in 802.11 it will switch off Bluetooth.

'A more sophisticated version is where Bluetooth will be told by the 802.11 what frequencies are being used and it will avoid those frequencies - advanced frequency-hopping.'

Perhaps this will be the killer argument against those who believe that 802.11 and Bluetooth are rivals. After all, just because you've got an Ethernet adaptor in your PC, you still need USB slots to connect your peripherals.

SENSE OF SECURITY
Security is a massive issue these days, and wireless technologies have come under more fire than most. You need only look at 802.11b for proof. So many wireless networks leak out into the public sphere that knowledgeable notebook users can easily surf the Internet using them. And it only takes a certain amount of willpower to break into a badly secured network and access what should be confidential documents.

Bluetooth is less likely to cause security problems. For one, it's usually based on data passing between two devices, limiting the scale of leaks. What's more, before you even form a partnership with another device - which requires permission at both ends - you need to exchange a numeric passkey, much like a PIN. The only problem with this is that passkeys are hugely guessable - try 5555, 1234 or, indeed, nothing and you're likely to gain success. Apparently, the industry doesn't consider security as a big issue.

'IMS Research did a survey, and within our research we talked to the big OEMs who designed Bluetooth into their phones, their cars and their PCs, and security hasn't been highlighted as a major issue for anybody. So I can only conclude that it's not an issue,' said Towers.

But this doesn't mean that Bluetooth is impregnable. Just as with 802.11b, there's the possibility that others can intercept your data as it's being transmitted from one device to another. However, unlike 802.11, Bluetooth uses frequency-hopping to make this more difficult. As with any wireless protocol, Bluetooth also has built-in encryption. If security is required, a 128-bit random number - the link key - is used in the authentication process. If two devices share a partnership, when that partnership was set up a link key would have been defined.

There are other hurdles too, as TDK shows in its rather tongue-in-cheek guide to hacking into a Bluetooth 'conversation':

'First hang around other people's offices or follow people in the street, staying within 10m of them. Try not to look suspicious with those three supermarket trolleys of equipment, all those cables and the antenna.

'Now, tune your receiver into the 2.4GHz band, find one of 79 active radio channels. Very quickly spot some packetised data, demodulate and de-encrypt it using the 128-bit encryption key for that particular radio dialog.