Shortly after Alexander Graham Bell patented the telephone, someone else developed a better version. Bell's inferior device prevailed, however, and his rival's invention was forgotten. The bottom line: first isn't always the best, but it's sometimes the most successful.

And the same may apply to products based on Bluetooth, a cheap wireless networking technology for offices and mobile workers.

Ericsson is renowned for researching and building functional products, but has a tendency to be slow to market its wares. For example, it lost out in the wireless application protocol (Wap) battle to Nokia - not because Nokia's 7110 handset was better, but because it made it to market before Ericsson's R320, and therefore gained valuable visibility as the generic Wap handset.

But Ericsson now wants revenge, and is the first to produce and release a device based on Bluetooth, which is designed to replace cables in short-range, so-called personal area networks (Pans).

The company's first commercially available standalone appliance is a wireless headset for mobile phones. Ericsson formed a special interest group with Nokia, IBM, Intel and Toshiba in 1998 to develop the technology.

Bluetooth is based on single-chip networking technology, which provides communication on the 2.4Ghz radio frequency. Devices have a range of about 10 metres and up to eight other devices can link to form a piconet, or Pan.

Piconets communicate with each other easily and the chips can change frequency at about 1600 hops per second. This phenomena is known as frequency hopping and provides protection against interference.

The Ericsson offering has two elements: the headset and a Bluetooth transceiver that can connect either to an Ericsson T28 or R320 phone.

Teething troubles
But while the concept is sound - using a dedicated slice of the radio spectrum to enable communication between Bluetooth devices - the headset appears to have its faults. The Bluetooth adaptor often needs unplugging and replugging to work, and some remaining software issues can cause error messages when trying to configure the headset.

So questions remain as to whether the headset is a precursor of better things to come, or if it represents the limit of Bluetooth's commercial capabilities. A useful analogy would be the Model T Ford: by the end of the year, we are more likely to be using the Bluetooth equivalent of a Jaguar 'E' type.

But while this does not mean people should sneer at Ericsson's offering (Model Ts are valuable collectors' items), there will be a wider range of products available in future that will do more than just connect a mobile phone to a headset.

Problems aside, Bluetooth does undoubtedly offer one key advantage to applications such as this - its range. The broadcast range of the device is quite respectable, about five metres through walls, or about eight to 10 metres with line of sight.

Future devices are expected to provide ranges of up to 100 metres, however, which means they could be used to create a poor man's wireless data network, and improve wireless telephony communications.

While Ericsson doesn't intend to offer Bluetooth products outside the mobile communications arena, other manufacturers, such as modem maker Xircom, are already playing with Bluetooth network cards for laptops and personal digital assistants (PDAs).

And it is here that hype and reality may meet. With the onset of general packet radio service (GPRS) technology, mobile communication users will have 'always-on' access to the internet at about 115Kbps.

For the business person 'on the go', for example, it would be nice to know that a Bluetooth-enabled GPRS handset could instantly download new emails onto a laptop or PDA.

Also, because the frequency of Bluetooth headsets does not interfere with aircraft systems, it could be possible for passengers who are not sitting together to communicate during a flight.

The downside of this is obvious, however, to all those who listen to loud phone conversations on public transport.

Summary:

• By the end of the year, there will be functional and useful Bluetooth devices available for use with telephony and data applications.
• Ericsson is first to market with a product that has a Bluetooth-enabled telephony headset.