Zigbee low power mode when both devices are battery-powered

Question

Does Zigbee allow low power mode when the communication is between 2 battery powered devices so that both can last longer on the batteries?

I suppose typically there's a mains-powered host that would be listening for transmissions from battery powered devices that would wake-up and transmit occasionally which would make it low power on the battery-powered side.

But what about a communication between 2 battery powered devices? Whould it require a synchronized clocks between the 2 for them to synchronously wake up for communication?

Answer 1

In ZigBee there is always a Coordinator that starts the network. There can optionally be Routers as well (the Coordinator is a Router as well). The Coordinator and Routers are always on (typically mains powered) devices. LowPower devices are called EndDevices and they can sleep. EndDevices need the Coordinator or a Router as the "Parent", the Parent queues messages for their EndDevice "Children".

So there is no synchronization between 2 EndDevices that are communicating. They send the message to the other EndDevice, which is queued by its parent, when they wake up they "poll" the parent to see if there are any messages queued.

You can use one of these SDK's: http://www.ti.com/tool/z-stack

And this packet sniffer: http://www.ti.com/tool/packet-sniffer

To test the behavior.