ZigBee Networks

Zigbee networks are called personal area networks (PAN). Each network contains a 16-bit identifier called a PAN ID.

ZigBee defines three different device types – coordinator, router, and end device.

Coordinator – Responsible for selecting the channel and PAN ID. The coordinator starts a new PAN. Once it has started a PAN, the coordinator can allow routers and end devices to join the PAN. The coordinator can transmit and receive RF data transmissions, and it can assist in routing data through the mesh network. Coordinators are not intended to be battery-powered devices. Since the coordinator must be able to allow joins and/or route data, it should be mains powered.

Router – A router must join a ZigBee PAN before it can operate. After joining a PAN, the router can allow other routers and end devices to join the PAN. The router can also transmit and receive RF data transmissions, and it can route data packets through the network. Since routers can allow joins and participate in routing data, routers cannot sleep and should be mains powered.

End Device – An end device must join a ZigBee PAN, similar to a router. The end device, however, cannot allow other devices to join the PAN, nor can it assist in routing data through the network. An end device can transmit or receive RF data transmissions. End devices are intended to be battery powered devices. Since the end device may sleep, the router or coordinator that allows the end device to join must collect all data packets intended for the end device, and buffer them until the end device wakes and is able to receive them. The router or coordinator that allowed the end device to join and that manages RF data on behalf of the end device is known as the end device’s parent. The end device is considered a child of its parent.