Team C²J

802.15 and ZigBee

    In an effort to standardize PWAN communications, the IEEE organized the 15th working group of IEEE 802 communications standards body.  This working group was concerned with PWAN communications as a whole and divided itself into several task groups to handle more specific applications.

    The 1st task group developed standards derived on Bluetooth 1.1 while the 2nd task group focused on the problem of coexisting 802.15 devices with devices from other standards using the same frequencies.  The 3rd task group was responsible for a high rate WPAN standard to be used when battery life was not as critical of an issue.

    The 4th task group was responsible for specifying standards for low-data rate, long battery-life, and low complexity applications.  The first standards were released in 2003.  In 2005, the task group released a revised standard that specified the 2.4Ghz Chirp Spread Spectrum as well as ultra-wide band (UWB) usage for data and positioning.  This year the task group released the 802.15.4-2006 revised standard, removing ambiguities and reducing complexity.

    ZigBee is a defined set of protocols that meet the 802.15.4 standards.  ZigBee is regulated by the ZigBee alliance and is currently in version 1.0 of the specification. The ZigBee alliance hopes to release a version 1.1 which will take advantage of some of the changes made in 802.15.4-2006.

    ZigBee devices are marketed as being simpler and cheaper than bluetooth with current radios requiring around %50 of the code required by a comparable bluetooth unit.  ZigBee radios can be as cheap as $1.10 per unit when mass produced.