What is Zigbee?
Zigbee is a technology of data transfer in wireless networks. It is the only standards-based wireless technology designed to address the unique needs of low-cost, low-power wireless sensor and control networks in markets like Smart energy/smart grid, AMR (Automatic Meter Reading), lighting controls, building automation systems, tank monitoring, HVAC control, medical devices.
Since ZigBee can be used almost anywhere, is easy to implement and needs little power to operate, the opportunity for growth into new markets, as well as innovation in existing markets, is limitless. ZigBee offers a variety of innovative standards smartly designed to help you control and monitor almost anything remotely and thus helps design green systems and save money.
With hundreds of members around the globe, ZigBee uses the 2.4 GHz radio frequency which is can be used without any restrictions throughout the world.
A key component of the ZigBee protocol is the ability to support mesh networking. In a mesh network, controllers are interconnected with other controllers so that multiple pathways connect each controller. Connections between controllers are dynamically updated and optimized through sophisticated, built-in mesh routing table. Mesh networks are decentralized in nature; each controller is capable of self-discovery on the network.
Also, as controllers leave the network, the mesh topology allows the controllers 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 controllers.
Zigbee Coordinator: Is a device which acts as a master controller in the system responsible for initializing network and managing secure entry to other controllers in the network. It also acts as a gateway in most cases to transfer data from Zigbee PAN to Internet gateway.
This device remains always ON in the network and apart from acting as a sensor controller itself, is responsible for routing other sensor controller data as well. In a streetlight monitoring system, most of the controllers operate in router controller as they have ample power supply available.
Zigbee Router/End device
This device typically operates on batteries and can be dropped anywhere in the network. It finds its parent and starts communicating. This device is typically limited in resources (memory, power supply etc). i.e in data logger system, most of the data logger modules would operate in this mode.