ARM has become the latest player to throw its weight behind the Bluetooth wireless networking project, a special interest group originally founded by Ericsson, IBM, Intel, Nokia and Toshiba and now attracting a high level of industry support. Bluetooth aims to replace wired local area networks (LANs) with an array of computers, phones, PDAs and consumer electronics that contain embedded radios. Simon Ellis, a marketing communications manager with Intel, says: The fundamental thing we’re trying to achieve is to replace the need of all these wires with wireless radio. These radios will use the international industrial, scientific and medical (ISM) spectrum – 2.4 GHz – to deliver an asymmetric 720Kbps link with a 56Kbps back channel between the different devices. That 2.4GHz also happens to be the spectrum power sources in microwaves ovens use, so the radios have been designed to tolerate interference. If there is a collision, Ellis explains, the radio detects the error and retransmits the signal. The algorithm for the voice coder/decoder has also been chosen for its ability to degrade gracefully. At the moment a Bluetooth radio requires two CMOS microprocessors: one radio and one baseband chip. As the technology advances, Ericsson hopes to combine those two chips into one, bringing the per-unit price from $20 to $5 in the process. The interface between the radio and the computer or other host device is a Universal Serial Bus (USB) port. The hardest thing in developing Bluetooth was to get the radio companies to agree on one solution, Ellis reveals. It turns out that the concept of a radio operating at this frequency with this capability already existed, meaning there were a number of different designs. In particular, Ericsson and Nokia had rival versions. We came together to take best of both designs and bring them together, Ellis says, it’s not a perfect spec. It is, however, an open standard. Any company that wants to market Bluetooth-enabled devices can sign a contract and get a royalty-free license. Among those who have already come to the Bluetooth party are Motorola, 3Com, Compaq, Dell, HP, Sony and Qualcomm. A developers’ conference is scheduled for October 27-29 in Atlanta, Georgia. Developers will be given a preview of Bluetooth as developed by the five founders, and they’ll get a chance to influence the final spec. The first Bluetooth-enabled products are expected to ship in the third or fourth quarter of 1999.
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