Can't locate airplay icon on my I phone or I pad

See

http://support.apple.com/kb/ts4215

I'm having the same problem. Just got a new iMac with latest edition of Mountain Lion, latest version Apple TV, iPad3, iPhone5. As recently as last week used Airplay from the iPad, went to use it tonight and there is no Airplay icon. Apple TV network test is fine, can connect to iTunes, Netflix, everything else via my wireless, but no Airplay. Same for all my devices. They are connected and working fine individually, but no connection to Apple TV. I did everything that they suggested, still no luck.

Any other help would be appreciated.

Go to istumbler.net and verify any interference