IEEE 802.15.4/ZigBee is intended as a specification for low-powered networks for such uses as wireless monitoring and control of lights, security alarms, motion sensors, thermostats and smoke detectors.
802.15.4/ZigBee is built on the IEEE 802.15.4 standard that was ratified earlier this month and specifies the MAC and PHY layers. The "ZigBee" comes from higher-layer enhancements in development bye a multivendor consortium called the Zigbee Alliance. For example, 802.15.4 specifies 128-bit AES encryption, while ZigBee specifies but how to handle encryption key exchange.
802.15.4/ZigBee networks are slated to run in the unlicensed frequencies, including the 2.4-GHz band in the U.S.
Pat Kinney, chairman of the IEEE 802.15.4 Task Group, chairman of the ZigBee Building Automation Profile Work Group and principal of Kinney Consulting in Export, Pa., says corporate IT staffs will likely end up responsible for managing these networks. If nothing else, they'll need to be involved to avoid interference issues between ZigBee networks and wireless communications networks, such as 802.11-based LANs.
802.15.4 is part of the 802.15 wireless personal-area network effort at the IEEE. It is a simple (28K byte) packet-based radio protocol aimed at very low-cost, battery-operated widgets and sensors (whose batteries last years, not hours) that can intercommunicate and send low-bandwidth data to a centralized device.
In the context of a business environment, this results in wireless automated monitoring and control of facilities. There are many applications for home-appliance networks, too, and for home healthcare. Kinney says that residential gateways that merge traffic onto a broadband Internet connection are slated to get ZigBee slots for this purpose.
Yet another protocol was needed for the widget communications job, says Kinney, because other short-range protocols such as 802.11 and 802.15 (Bluetooth) use too much power and the protocols are too complex (and thus more expensive) to be embedded in virtually every kind of device imaginable.
From ZigBee vendor group to wireless-enable facilities monitoring, Network World on Wireless in the Enterprise, 08/25/03.
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