Device types

Zigbee defines three different device types: coordinator, router, and end device.

Coordinator

Zigbee networks always have a single coordinator device. This device:

• Starts the network, selecting the channel and PAN ID.
• Distributes addresses, allowing routers and end devices to join the network. Assists in routing data.
• Buffers wireless data packets for sleeping end device children.
• Manages the other functions that define the network, secure it, and keep it healthy. This device cannot sleep and must be powered on at all times.

Router

A router is a full-featured Zigbee node. This device:

• Can join existing networks and send, receive, and route information. Routing involves acting as a messenger for communications between other devices that are too far apart to convey information on their own.
• Can buffer wireless data packets for sleeping end device children. Can allow other routers and end devices to join the network.
• Cannot sleep and must be powered on at all times.
• May have multiple router devices in a network.

End device

An end device is essentially a reduced version of a router. This device:

• Can join existing networks and send and receive information, but cannot act as messenger between any other devices.
• Cannot allow other devices to join the network.
• Uses less expensive hardware and can power itself down intermittently, saving energy by temporarily entering a non responsive sleep mode.
• Always needs a router or the coordinator to be its parent device. The parent helps end devices join the network, and stores messages for them when they are asleep.

Zigbee networks may have any number of end devices. In fact, a network can be composed of one coordinator, multiple end devices, and zero routers.

An example of such a network is shown in the following diagram:

Note Each Zigbee network must be formed by one, and only one, coordinator and at least one other device (router or end device).