https://support.apple.com/en-us/HT202618
Apple TV Settings for the Classroom
http://learninginhand.com/blog/appletv
Get help with AirPlay and AirPlay Mirroring on your iPhone, iPad, or iPod touch
https://support.apple.com/en-us/HT204291
Recommendations
Follow these recommendations for the best possible AirPlay experience:
- Apple TV should be connected to Ethernet if available.
- Mount the Apple TV with the rubber side touching the surface it's mounted to.
- Mount the Apple TV with few or no obstructions between it and the other device.
Any objects between the two devices could interfere with the BTLE or Wi-Fi signals. Mounting the Apple TV in a cabinet, behind a TV, above a projector, or in the ceiling could degrade the signal between the devices. - If possible, avoid using Wi-Fi channels 149 and 153 in rooms where peer-to-peer AirPlay is frequently in use.
- Though the devices will share air time fairly with the infrastructure network, removing any conflicting traffic from the room improves the stability of the AirPlay session. The fourth–generation Apple TV can also use an 80 MHz wide 802.11ac channel at 149,80 if the device streaming to it is also 802.11ac capable, though the increased throughput available with 802.11ac makes airtime contention less of a concern.
Official Link: http://help.apple.com/deployment/ios/#/apd8fc751f59