We're beginning to hear more and more about this wireless technology called ZigBee. A catchy name for sure, but what is it and who needs it? We already have Bluetooth- and Wi-Fi-enabled devices, and WiMAX and Wireless USB proliferation are at the doorstep. Who needs another wireless standard?
Each wireless technology that makes it to market serves a special purpose or function. Bluetooth and wireless USB provide short-range connectivity in what is called a personal-area network (PAN). Bluetooth serves a short-range, moderate-speed, wire replacer, and wireless USB provides short-range, high-speed device connectivity. Wi-Fi is for local-area networks (LANs) and WiMAX is designed to provide wide-area networking (WAN) or metropolitan-area networking (MAN).
ZigBee fills yet another industry niche. It is a PAN technology based on the IEEE 802.15.4 standard. Unlike Bluetooth or wireless USB devices, ZigBee devices have the ability to form a mesh network between nodes. Meshing is a type of daisy chaining from one device to another. This technique allows the short range of an individual node to be expanded and multiplied, covering a much larger area.
One ZigBee network can contain more than 65,000 nodes (active devices). The network they form in cooperation with each other may take the shape of a star, a branching tree or a net (mesh). What's more, each device can operate for years off of a AA cell. That means that each node uses little power.
What might be perceived as a disadvantage is the low data rate of ZigBee devices, typically less than 100 kbps, depending on the selected frequency band. Is slow bad? That depends on the function or service the technology is intended to provide.
Who needs ZigBee?
If you are looking for wireless monitoring and remote control solutions, ZigBee may be the answer. Those are the functions for which ZigBee was designed. ZigBee nodes can be used to tie an entire home, office or factory together for safety, security and control.
Nodes are embedded in hundreds of sensors and controls that are built into large infrastructures for home automation, industrial automation, remote metering, automotives, medical equipment, patient monitoring, asset tracking systems, security systems, lighting and temperature control systems, and even toys.
There are three categories of ZigBee devices:
- ZigBee Network Coordinator. Smart node that automatically initiates the formation of the network.
- ZigBee Router. Another smart node that links groups together and provides multi-hoping for messages. It associates with other routers and end-devices.
- ZigBee End Devices. Where the rubber hits the road-sensors, actuators, monitors, switches, dimmers and other controllers.
Bottom line - ZigBee networks provide smart, low-cost, low-power, low-maintenance monitoring and control systems.