ZigBee is an open global standard for wireless technology designed to use low-power digital radio signals for personal area networks. ZigBee operates on the IEEE 802.15.4 specification and is used to create networks that require a low data transfer rate, energy efficiency, and secure networking. It is employed in a number of applications such as building automation systems, heating, and cooling control and in medical devices.
The technology defined by Zigbee specification is intended to be simpler and less expensive than other wireless personal area networks (WPANs), such as Bluetooth or more general wireless networking such as Wi-Fi. Applications include wireless light switches, home energy monitors, traffic management systems, and other consumer and industrial equipment that requires short-range low-rate wireless data transfer. Zigbee devices can transmit data over long distances by passing data through a mesh network of intermediate devices to reach more distant ones.
Its low power consumption limits transmission distances to 10–100 meters line-of-sight, depending on power output and environmental characteristics. Zigbee is typically used in low data rate applications that require long battery life and secure networking. Zigbee has a defined rate of 250 kbit/s, best suited for intermittent data transmissions from a sensor or input device. Zigbee was conceived in 1998, standardized in 2003, and revised in 2006. The name refers to the waggle dance of honey bees after their return to the beehive.
One of ZigBee’s defining features is the secure communications it is able to provide. This is accomplished through the use of 128-bit cryptographic keys. This system is based on symmetric keys, which means that both the recipient and originator of a transaction need to share the same key. These keys are either pre-installed, transported by a “trust center” designated within the network or established between the trust center and a device without being transported. Security in a personal area network is most crucial when ZigBee is used in corporate or manufacturing networks.
Zigbee protocols are intended for embedded applications requiring low power consumption and tolerating low data rates. The resulting network will use very little power, individual devices must have a battery life of at least two years to pass Zigbee certification. Applications include Home automation, wireless sensor networks, industrial control systems, embedded sensing, medical data collection, smoke & intruder warning, building automation, remote wireless microphone configuration.