A specification for a suite of high level communication protocols used to create personal area networks built from small, low-power digital radios based on an IEEE802.15 standard. Though low-powered, ZigBee devices can transmit data over long distances by passing data through intermediate devices to reach more distant ones, creating a mesh network; i.e., a network with no centralized control or high-power transmitter/receiver able to reach all of the networked devices. The decentralized nature of such wireless ad hoc networks make them suitable for applications where a central node can't be relied upon.
The IEEE802.15.4-2003 ZigBee specification was ratified on December 14, 2004.
The ZigBee Alliance announced availability of Specification 1.0 on June 13, 2005, known as the ZigBee 2004 Specification.
There are several variants:
ZigBee 2006 Specification was announced in September 2006, obsoleting the original 2004 stack. This specification mainly replaces the Message/KeyValuePair structure used in 2004 with a "cluster library".
ZigBee PRO (also known as Zigbee 2007), the enhanced ZigBee Pro Specification, was posted on 30 October 2007, and was finalized that same year. ZigBee PRO is fully backward-compatible with ZigBee 2006 devices. A ZigBee 2007 device may join and operate on a ZigBee 2006 network and vice versa. Due to differences in routing options, ZigBee PRO devices must become non-routing ZigBee End-Devices (ZEDs) on a ZigBee 2006 network and ZigBee 2006 devices must become ZEDs on a ZigBee PRO network. The applications running on those devices work the same, regardless of the stack profile beneath them. The first ZigBee Application Profile, Home Automation, was announced November 2, 2007.