AppleTV's are currently supported for AirPlay in Peer-to-Peer mode only. The AppleTV devices should be wired to access all other network resources. Peer-to-Peer AirPlay allows the AppleTV and Supported iOS or Mac device to discover one another over Bluetooth Low Energy. The stream will then be sent directly between the two devices on 40Mhz channel 149. To minimize co-channel contention, we do not use these channels to serve clients on Grizznet.

References: https://help.apple.com/deployment/ios/#/apd8fc751f59