 group of manufacturers and allows any device, including computers, cell phones, and headphones, to auto- matically establish wireless device-to-device connections. The Bluetooth Special Interest Group, comprising more than 1,000 companies, works to support Bluetooth's role as a replacement technology for connectivity between peripherals, telephones, and computers. In effect it is a cable replacement solution and is often cited as the ideal way to simplify the rat's nest typically found behind most computer desks. Bluetooth operates at 2.45 GHz, a spectrum allocation set aside for the use of industrial, scientific, and medical devices (ISM). The system is capable of transmitting data at 1 Mbps, although headers and hand- shaking information consume about 20 percent of this capacity. A num- ber of other devices operate within this domain as well, including baby Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. Access Technologies Access Technologies monitors, garage-door openers, and some cordless phones. The process of ensuring that Bluetooth and these other devices don't interfere with one another has been a crucial part of the design process and, today, is one of the major detractors to the technology. 2.5 GHz cordless phones have become SO popular that interference between them and Bluetooth- equipped devices has become a significant nuisance in some cases. Applications suggested for Bluetooth are interesting, and while they are distance limited because of the technology's low operating power level, plenty of opportunities have presented themselves. The standard specifies operational distances of up to 100 meters between Bluetooth- equipped devices, but because of power restrictions most devices will only be able to operate within a 10-meter radius. Bluetooth is designed for the creation of personal area networks (PANs) that rely on picocel