Pioneered by Philips Semiconductors, ZigBee is a low data rate, two-way standard for home automation and data networks. The standard originates from the Firefly Working Group and provides a specification for up to 254 nodes including one master, managed from a single remote control. Real usage examples of ZigBee includes home automation tasks such as turning lights on, turn up the heat, setting the home security system, or starting the VCR. With ZigBee all these tasks can be done from anywhere in the home at the touch of a button. ZigBee also allows for dial-in access via the Internet for automation control.
The ZigBee standard uses small very low-power devices to connect together to form a wireless control web. A ZigBee network is capable of supporting up to 254 client nodes plus one full functional device (master). ZigBee protocol is optimized for very long battery life measured in months to years from inexpensive, off-the-shelf non-rechargeable batteries, and can control lighting, air conditioning and heating, smoke and fire alarms, and other security devices. The standard supports 2.4 GHz (worldwide), 868 MHz (Europe) and 915 MHz (Americas) unlicensed radio bands with range up to 75 meters.
[Reference: Philips Semiconductors Protocols - ZigBee]