ZigBee enables wireless embedded nets

Wireless embedded networks hold great promise for deployment in residential and commercial building-automation, industrial plant monitoring, and other wireless sensing and control applications. An association of corporations called the ZigBee Alliance is developing a standard for low-cost, low-power wireless embedded networking.

Version 1 of the ZigBee specification is set for release in the fourth quarter, and a number of platforms based on the standard are expected to be available around the same time. The specification provides network and application support services operating on top of the IEEE 802.15.4 standard of the media-access control layer and physical layer. ZigBee software may be implemented in microcontrollers for 802.15.4 radio chips.

The software employs a suite of technologies to enable scalable, self-organizing, self-healing networks that can manage a variety of traffic patterns. The standard is well-suited to applications such as lighting, heating and cooling controls; industrial building and automation; and medical device monitoring. The ZigBee Alliance's long-term goal is to enable a scalable, low-cost, embedded infrastructure based on interoperable platforms and profiles that will let devices communicate in ways that have been impractical until now.

The ZigBee standard defines three types of devices: ZigBee coordinator devices, ZigBee router devices and ZigBee end devices. Every network must contain only one ZigBee coordinator.

The primary responsibility of the coordinator is to set up the parameters for building a network and to start that process, including choosing a radio-frequency channel, a unique network identifier and a set of operational parameters.

ZigBee routers can be used to extend the range of a network by acting as relays between devices that are too far apart to communicate directly.

ZigBee end devices do not participate in routing.

All these devices can take on other roles an application requires.