If information appliances do outsell PCs by 2002, as market studies project, a technology called Bluetooth will come into its own.

Bluetooth will connect all kinds of devices wirelessly and (its backers hope) effortlessly. At 0.1W of power and a potential cost of £3 or less per device in mass-market volume, Bluetooth is both low-powered and relatively low-priced — qualities that make it ideal for mobile appliances.

With a single, small radio chip, Bluetooth technology can replace cumbersome cable connections in all sorts of devices, from laptops to headphones to printers. It's likely to turn up in the second half of this year in some high-priced mobile phones and as an option on some laptops.

On your laptop, Bluetooth will provide a simple way to wirelessly send pages to a printer or to hook up to the Internet by connecting wirelessly with your Bluetooth-enabled mobile phone. Your phone itself could reside safely in your pocket as you have a conversation over a Bluetooth wireless headset such as the one recently demonstrated by Ericsson.

But Bluetooth can do more than just replace point-to-point cables. Its supporters say a second wave of applications will follow next year. We could see Bluetooth used to join multiple devices into an instant, ad hoc network. Some envision executives in a meeting linking their handheld computers to compare agendas or to exchange virtual business cards. A speaker's laptop could wirelessly "squirt" its slides to an LCD projector.

Another advanced use would be Internet or LAN access points — by standing near the access point, your mobile phone or handheld could log on at a quite respectable speed of 721K kbps.

Bluetooth was proposed two years ago by Ericsson, IBM, Intel Corp., Nokia and Toshiba, which formed the Bluetooth Special Interest Group (SIG). They have since been joined by almost 2,000 companies. The technology is named after 10th century Danish King Harald Blaatand (Blue Tooth), who unified Scandinavia.

When the technology was first announced in May 1998, there were optimistic predictions that Bluetooth products would flood the market by late 1999. But various factors have worked against that scenario, including the hesitance of Microsoft to commit to the Bluetooth protocol. The software maker finally joined the SIG in December, opening the door to Bluetooth support in Windows and on Pocket PCs.

Bluetooth is essentially a radio receiver operating in a spread-spectrum mode; it changes frequency for every data packet some 1,600 times per second. This synchronised frequency-hopping, together with low power that limits range to a few feet, is what enables one Bluetooth connection to avoid interfering with another.

This technology faces some major challenges before it reaches its lofty goals. There are, as yet, no Bluetooth products in stores. Only a handful of prototypes have even been demonstrated at trade shows over the past six months.

Price is a big issue at present. There's a reason infrared ports, despite their limitations, are so widely used: They're cheap. It costs only a few pounds to add them to a system, whereas Bluetooth still costs more than £15. That's irrelevant for a £1,500 laptop, but it's a big problem for a £100 handheld.

Standards are another problem. While the first Bluetooth applications are relatively simple, more advanced applications such as ad hoc and multipoint connections require a software standard. Devices need to know how to discover one another on the network and figure out how to cooperate. Two emerging technologies — Sun's Jini and Microsoft's Universal Plug-n-Play — address this issue, but it's too soon to say whether either will emerge as a standard. Fortunately, experts say devices could support both at once.