IT Help Central has been unsuccessful in connecting Apple TV devices to TTUnet Wi-Fi. As a workaround, customers may connect Apple TV to the TTUnet wired network.
To use AirPlay, the devices you're using to connect to Apple TV must be on the same network. As such, you will only be able to use AirPlay over the TTUnet wired network. If you are trying to connect to Apple TV over Wi-Fi using AirPlay, it will not find the Apple TV; as a workaround, you can connect a laptop to the TTUnet wired network, and then try sharing an ad-hoc Wi-Fi network from the laptop to your iPhone or iPad.