Zigbee association

As previously mentioned, Zigbee end devices (ZED) do not participate in routing. End devices communicate with the parent, who is also a router. When a Zigbee coordinator (ZC) allows for a new device to join a network, it enters a process known as an association. If a device loses contact with its parent, the device can at any time rejoin through the process known as orphaning. 

To formally join a Zigbee network, a beacon request is broadcast by a device to ask for subsequent beacons from devices on the mesh that are authorized to allow new nodes to join. At first, only the PAN coordinator is authorized to provide such a request; after the network has grown, other devices may participate.