A Year Ago: Bluetooth - the invisible link

First publised: Wed, 20 May 1998 16:58:59 GMT

The next generation of wireless networking was unveiled today with the announcement of ‘Bluetooth'. Created by a consortium of mobile phone, portable computer and chip companies, Bluetooth is a high-speed, low-power microwave wireless link technology, designed to connect phones, laptops, PDAs and other portable equipment together with little or no work by the user.

Unlike infra-red, Bluetooth does not require line-of-sight positioning of connected units. The technology uses modifications of existing wireless LAN techniques but is most notable for its small size and low cost. The current prototype circuits are contained on a circuit board 0.9cm square, with a much smaller single chip version in development. When the system is introduced in the second half of 1999, it is expected to cost around £20 per unit, falling to under £3 over the following two years. It is envisioned that Bluetooth will be included within equipment rather than being an optional extra.

Although protocol and software details are not yet finalised, the fundamentals are in place. When one Bluetooth product comes within range of another - this can be set to beween 10cm and 100m - they automatically exchange address and capability details. They can then establish a 1 megabit/s link with security and error correction, to use as required. The protocols will handle both voice and data, with a very flexible network topography.

The consortium - led by Ericsson, IBM, Intel, Nokia and Toshiba - envisage the technology appearing first for data links between phones, mobile computers, digital cameras, printers, and Internet and telephony access points. Typical applications include email delivery to laptops via phones, potentially without the user even being aware that activity is taking place; cable-free connection to the Internet in public areas, calendar and address book synchronisation between PDAs, phones and desktop PCs, and hands-free handsets. No licence fees will be charged for Bluetooth products, although a product conformity check process will exist for approval marks.

Some questions remain to be addressed, such as how the system will interact with existing users of Bluetooth's 2.4 GHz radio frequency. This is an unlicenced band, already utilised by IEEE 802.11 wireless LANs, microwave ovens and various commercial data transmission systems. Torbjorn Gardenfer, product consultant for Ericsson, said: "They will interfere with each other, and the stronger signal will win."

As Bluetooth will typically operate with between 1/100th and 1/500th of the power of other systems, the potential for interference is high. However, if it achieves the level of ubiquity that its designers expect, Bluetooth has the potential to increase the connectivity of everyday objects by a tremendous amount.