Bluetooth (the moniker refers to a 10th-century Danish king) is not a substitute for other forms of wireless communications. It operates over a very short range-roughly up to 10 meters. That’s plenty far enough, however, for a slew of applications. Your handheld organizer, for one thing, could radio its contents to the PC in your briefcase, updating its address book and appointment calendar. A Bluetooth-equipped computer on the passenger seat could dial up a Net connection using the cell phone in your pocket, download e-mail-and page you if it retrieved any messages marked “urgent.” A Bluetooth headset could even read your messages to you aloud while you drive, using commonly available text-to-speech software. Bluetooth-equipped keyboards, mice, printers and other peripherals would dispense with the need for many of those annoying connection cables.
Bluetooth will operate in a microwave portion of the radio spectrum (between 2.4 and 6 gigahertz) that is now used by some microwave ovens as well as an assortment of industrial, scientific and medical equipment. This is an “unlicensed” swath of spectrum, meaning anyone who wants can use it. To avoid interference problems, Bluetooth will employ a frequency-hopping technology. Devices in proximity with one another establish an ad hoc network in which the transmission frequency changes 1,600 times a second in a programmed sequence, in effect dodging potential interference.
Does the world really need another networking technology? Analysts say yes-if costs are kept low. The goal is for Bluetooth modules to add only $5 to $10 to the cost of a product-a trivial margin for a portable computer or handheld organizer, though a bit more significant for a cell phone or pager. If manufacturers hit that target, Bluetooth could “revolutionize the way people use” information devices, says Phillip Redmond of the Yankee Group in Boston.
Bluetooth is not the only game in town for short-range wireless connections. Infrared links can serve much the same purpose-and are being built into a growing number of computers and peripherals. Unlike Bluetooth, however, infrared communication requires that the devices point at each other. Because of infrared’s line-of-sight constraint, some predict, Bluetooth will prevail.