Unfortunately the technology that Airplay uses to communicate between iPads and Apple TVs is what is called a “multicast traffic” which essentially blasts out its location to all computers that are listening for that type of traffic. The problem is that since a single network segment can only handle upwards of 254 addresses that means only 254 computers could theoretically be on the network at once. Our network is set up in such a way that there are somewhere in the neighborhood of 30 wireless network segments to allow all wireless devices to be able to access our network. The type of “multicast traffic” that Airplay uses can’t technologically cross between these network segments without causing so much traffic that it could reduce the wireless network to a crawl. If the airplay device and your iPad happen to be in the same network segment (1 in 30 chance) then Airplay will actually work on campus. However there is no way to guarantee that they will be on the same network.
We will continue to evaluate this, and if there comes a time when we can technologically implement this without crashing the wireless network we will certainly be looking to implement this in classrooms and presentation rooms. This is not just a USD issue, but one in which any enterprise network faces when looking to implement Airplay capability.