ZigBee Devices (FFD & RFD)

The IEEE 802.15.4 specification identifies two devices which is FFD and RFD. The 802.15.4 Full Function Device (FFD) is literally able to do it all. A FFD network will be powered from an inexhaustible power source, which is called out as an AC-fed mains supply, as it must always be active and listening on the network, among other things.
An RFD (Reduced Function Device) perform on recording temperature data, monitoring switches or controlling external devices. The power source of RFD is easily exhaustible and by that RFD is prone to sleep most of the time.
The ZigBee end device can be either an FFD or RFD depending on the application. A ZigBee router is an FFD that enables the extension of the physical range of a ZigBee network. It is used to allows more nodes to join the network as the radio range of the root ZigBee network is effectively increased. The router also can be functioning as a end devices.