Bluetooth wireless connectivity holds promise for business applications, but has suffered through early hype and a protracted ratification process to finalise the specification. With many Bluetooth products already shipping and more in the pipeline, the pressure is now on developers to offer applications support.

Bluetooth began at handset maker Ericsson as a concept for linking phones wirelessly to peripherals such as headsets. When Ericsson sought partnerships with other makers of portable electronic equipment, it became clear that the technology would be useful for a wide range of applications.

Since the formation of the Bluetooth Special Interest Group (SIG) in 1998, the number of proposed applications has grown dramatically. "The PC industry is driving complexity into Bluetooth. They want to build in support for absolutely everything," said Nick Hunn, managing director of Bluetooth vendor TDK Systems. New applications extended the specification, but this process delayed the delivery of the first products by several years. Early products suffered because vendors rushed to market before the specification was finalised, and many products had difficulty interoperating with kit from other manufacturers.

These setbacks led to a popular backlash in 2000, when some industry observers predicted that the growing use of wireless LAN (WLAN) standards would make Bluetooth obsolete before it even got off the ground.

But Bluetooth is designed as a short-range, low-power standard for applications such as linking phones to PDAs or laptop PCs, for which WLAN standards such as 802.11b would be inappropriate. Bluetooth is also expected to serve as a replacement for cable interfaces in a variety of devices, ranging from mice and keyboards to industrial equipment such as barcode scanners.

Bluetooth can be used for accessing a LAN, but this only makes sense for devices such as PDAs that do not require high bandwidth. For now, linking to a mobile phone is still seen as the killer application for Bluetooth. Research firm Frost & Sullivan estimates that phones accounted for 44 percent of Bluetooth silicon shipments in 2001.

Bluetooth's focus is on the personal area network (PAN), where a user's devices can all communicate wirelessly within a typical range of 10 metres. Security is an obvious concern. Bluetooth has a number of security tricks, such as the requirement to enter a PIN number before a device will allow another to access it. Encryption and the fact that devices can frequency-hop up to 1,600 times a second add further protection. Frequency hopping in an ad-hoc network, or piconet, is controlled by one master device, which should make it hard for an outside node to eavesdrop on communications.

The factors most likely to affect Bluetooth acceptance are the cost of building it into devices and software support. Industry observers have said that the technology will take off when the price of Bluetooth chipsets falls to $5 or less. Last year's average price was about $15, but economies of scale could soon drive this down. Frost & Sullivan expects sales of Bluetooth chipsets to grow to 971 million by 2006.

On the PC side, Microsoft is expected to support Bluetooth in Windows XP this year, and both PalmSource and Symbian are supporting it for handhelds. The specification already includes rules that govern how devices interact with others, which is why Bluetooth is regarded as so complex.

Some members of the Bluetooth SIG are already planning Bluetooth 2.0. This would expand its range and transmission rates to match current WLAN technologies, but is still some years away. For now, the challenge for vendors is to get Bluetooth embedded in as many devices as possible and to tackle interoperability problems.

"Microsoft can help here," said Hunn. "If you can switch on a device and it works [with Windows], then people will use it."

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