I usually don't have a problem accessing the University Wifi. I connect to the internet most anywhere except in one classroom that is basically in the basement of a building.
In this underground classroom I have a strong WiFi signal since we have a wireless hub thingy in the room. I have the WiFi signal light up but I have no Voice Network Signal (t-Mobile).
I can get e-mails, but I can not get text messages, connect with my browser or the facebook App.
So I am thinking the voice network is needed for an internet connection even thru WiFi. Does this make any sense?