Innovation: PCs enter the wireless age

PERSONAL computers have achieved a new level of freedom with a development that allows them to be networked without being physically connected.

Local-area networks which transmit data by radio signals will allow companies to set up office computer networks without having to bring a cable to every desk. It will also mean that PCs can be included in a wired network.

At the moment there are probably fewer than 5,000 users of wireless networks in the UK, says Chris Sorrill, executive officer of the Mobile Data Association, an industry organisation set up in April to promote wireless data transmission. NCR and Olivetti have products on the market, but the technical standards have not been approved. IBM launches its wireless local-area network in the UK in November.

To create a wireless local- area network, users need to slot an adaptor card into the back of each computer. Up to 50 machines can be linked into one network, with one computer acting as a base station. Data can be transmitted up to 180m from the base station, far enough to cover most offices.

If a portable computer is being linked into a wired network, one of the wired computers needs an adaptor so it can act as a base station. Acting as base station does not interfere with the normal operation of the computer.

At pounds 637 each, the wireless adaptor cards are much more expensive than the Ethernet cards that link up fixed networks. Those are manufactured in such large volumes that they cost less than pounds 100. But difficulties in installing fixed cabling in some buildings means cost can go as high as several thousand pounds per computer.

Wireless networks will be particularly useful in listed buildings. Ron McCall, IBM's product manager for wireless local-area networks, points out that lots of banks, for instance, are in old buildings, and that listed status has prevented Harrods connecting up the tills in its food hall.

'In general, retailers are always moving things about, or would like to, and this technology will give them that flexibility.' Mr McCall said.

Wireless data transmission is expected to have a huge impact in hospitals. When patient records are kept on computer, either every bed needs a computer beside it, or staff must refer to a ward computer. With a wireless local-area network, hand-held computers can be used anywhere on the ward to access the ward computer.

Long-distance, or wide- area wireless data transmission, is a more mature technology, with about 55,000 users in the UK, Mr Sorrill says. These range from taxi drivers to the emergency services.

Mr Sorrill says local and wide-area networks are increasingly being used for general business applications. Wireless data technology is also spawning such products as combined hand-held computers and cellular phones.

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