The three different types of ZigBee gadgets in a ZigBee network are : Coordinator (Master) : Each ZigBee network has just one coordinator with the exclusive function to store information regarding the network and to decide the optimum transmission path between any two points of the network; Full Function Device (Router, Repeater) : Routers serve as an intermediate repeater
that passes information from other devices; Reduced Function Device (End Device) : This device has a minimal amount of functionality to allow it to talk to its parent node, which can be either the coordinator or the router.
Another important advantage of GPON is that it can carry information from a central office to subscribers up to 60 Km away without needing any intermediate repeaters
thus doing away with the requirement of power, shelter and upkeep services at the intermediate locations.
There are lower-speed digital radios that run the distance, so if you don't want intermediate repeaters
you have to go at a lower speed.