It's not the phone, it's the AT&T network which is sucks! Same thing happened to me when Boston celtics played here in CT for a exhibition match VS toronto raptors. We are using at that time
a 3G and 3Gs. The nearest cellsite was not capable of handling a huge amount of people that is why you can't send data.. The stadium should have "COW" - cellsite on wheels. That's what we called on it. Basically it was parked near the stadium and supporting the tower that is overloaded..
Or, since the stadium pretty much sits there year after year holding events and whatnot, maybe ATT might just realize that hey, this is a place we should invest some money into providing better service. Like here in Raleigh, we have a 60,000 seat college football stadium (Carter Finley) and a 21,000 seat basketball and hockey arena (RBC Center) right beside each other. Events happen at one of those facilities at least 180 nights a year if not more. Just suck it up and spend the money.