XBee T1
Zigbee Device Type
As mentioned, XBee is base on Zigbee protocol, and Zigbee is one of the main wireless protocol family. Zigbee defines a network layer above the 802.15.4 to support advanced mesh routing capabilities.
Since Zigbee protocol defines 3 devices type, so you might expect to configure them when using XBee modules to form a wireless network. XBee is made for the field application, and 1 to 1 communication is a special case of Zigbee application.
Coordinator
Zigbee networks always have a only one single coordinator device.
The coordinator can start the network, and allow routers and end devices to join it.
Router
A router is a full-featured Zigbee network node.
It can join the existing networks and send, receive, and route information.
It can also allow other routers and end devices to join the network.
End Device
An end device is essentially a reduced version of a router, include hardware and functions.
Can join existing networks and send and receive information
Cannot act as messenger between any other devices.
Cannot allow other devices to join the network.
Uses less expensive hardware
Always needs a router or the coordinator to be its parent device.
Zigbee Network Example
Coordinate + Router(s) + End Device(s)
Coordinate + Router(s)
Coordinate + End Device(s)
All the XBee applications will be one of these cases.