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

1. Coordinate + Router(s) + End Device(s)

2. Coordinate + Router(s)

3. Coordinate + End Device(s)

All the XBee applications will be one of these cases.

Reference Link

• Digi - ZigBee in a nutshell - Device Type