Zigbee is a wireless mesh protocol developed as an open global standard for products needing a low-cost, low-power wireless network option. It operates on IEEE 802.15.4 and unlicensed 2.4 GHz, 900 MHz, and 868 MHz. Zigbee was created and ratified by member companies of the Zigbee Alliance.
There are three node types in a Zigbee mesh network. They are the coordinator, routers and end devices. There can only be one coordinator. The coordinator sets up the network and chooses the operating channel and PAN ID. Once the coordinator establishes the network it acts as a routing node and manages other network functions. Coordinators cannot sleep and must be powered all the time.
A router can join existing networks and send, receive and route information. End Devices can join existing networks but can only communicate through their parent node and can not relay messages on to other nodes. End devices can sleep.
Image source: Digi International
Zigbee is a great option for commercial and industrial applications with noisy RF environments. Zigbee’s mesh capability is one of the reasons the topology works well in noisy applications. With mesh, nodes can automatically be rerouted to a new path if their current path has some sort of interference. Some common applications for Zigbee are smart energy, lighting controls, HVAC controls and fleet applications. Zigbee networks can operate with as few as two devices but can operate with hundreds of nodes as well.
The range of Zigbee devices depends on the type of device used and application environment. Typically indoor range between 2.4 GHz Zigbee nodes is 200-400 feet, so a few devices can usually cover an average home. If multiple routing or power amplified devices are used, the network range can be greatly extended.
The latest edition of Zigbee is Zigbee 3.0. This newer version allows for enhanced security options, which are centralized and distributed security. Zigbee 3.0 is backwards compatible with older versions. Another great feature of Zigbee is Over the Air (OTA) updates can be done.
One of my favorite products for Zigbee applications, as well as learning and teaching Zigbee, is the Digi International XBee®.
A full list of our Zigbee products can be found here.
For more information on Zigbee, please see this article by Digi International and this paper by Silicon Labs…