Actually, the non-battery-powered devices are the important part of Zigbee network. In Zigbee network, only coordinator and router can * route* the tracfic, others device can only send or receive. So if there is no other router or only few router, the Zigbed network will degrade from mesh topology to star topology. Because of power limit, the battery-powered devices are not suitable for router role so they almost is an end device. The AC-powered devices normally do router role.
