Why does my Apple TV cause wifi to drop on my MacBook? As soon as I attempt to connect my MacBook Pro to my Apple TV (in extended desktop or mirrored mode) my Macbook loses its wifi connection. Sometimes it will attempt to reconnect to the network, sometimes it won't. Even if it succeeds in reconnecting it will very soon drop again.

I have not been able to test whether using a wired connection on either the Apple TV or MacBook makes any difference yet but can try to give it a go if it's likely to make any difference.

The MacBook is late 2013 and is running Yosemite (but this was already a problem under Mavericks). The Apple TV is running 7.0.1, which I believe is the latest version.

I've tried resetting the SMC on the MacBook which appears to be the recommended solution to all sorts of Yosemite connectivity issues but that made no difference. What could be causing this, and what can I do to resolve it?
A few suggestions were made in this thread, which could play into it:

1) Check the device (Apple TV) to see if it is under a warranty replacement program
2) Try adjusting the settings on your WiFi router for the broadcast channels. Setting the device to 40MHz only instead of 20/40MHz auto might help alleviate.
3) Try changing the wireless encryption from WPA to WPA2 or vice versa. There may be an issue with how the devices interact with the authentication.