What is ZigBee and Why is it Important?
ZigBee is an IEEE 802.15.4 based specification for a suite of high-level communication protocols used to create networks with small, low-power digital radios, such as for home automation, and other low-power low-bandwidth needs.
The technology defined by the ZigBee specification is intended to be simpler and less expensive than other WPANs, such as Bluetooth or Wi-Fi. Applications include wireless light switches, electrical meters with in-home-displays, traffic management systems, and other consumer and industrial equipment that requires short-range low-rate wireless data transfer. The new NuBryte Smart Switch ( formerly Flex) uses ZigBee to interconnect with other Flex units in the home.
Zigbees low power use limits transmission distances to 10–100 meters line-of-sight, depending on environmental characteristics. ZigBee devices can transmit data over long distances by passing data through a mesh network( see below) of intermediate devices to reach more distant ones. ZigBee is typically used in low data rate applications that require long battery life and secure networking (ZigBee networks are secured by 128 bit symmetric encryption keys.) ZigBee has a defined rate of 250 kbit/s, best suited for intermittent data transmissions from a sensor or input device.
ZigBee Mesh Networks
A key component of the ZigBee protocol is the ability to support mesh networking Mesh networking is very different from what you're familiar with using WiFi.
Your work and home WiFi LAN are examples of a “star network” where all devices connect to a central hub, router or gateway. In a mesh network, nodes are interconnected with other nodes so that multiple pathways connect each node. If one node is out of service the other devices will “self route” because connections between nodes are dynamically updated and optimized through a sophisticated, built-in mesh routing table.
Mesh networks are decentralized in nature; each node is capable of self-discovery on the network. This feature makes ZigBee ideal for home automation devices. As nodes leave the network, the mesh topology allows the nodes to reconfigure routing paths based on the new network structure. The characteristics of mesh topology and ad-hoc routing provide greater stability in changing conditions or failure at single point.