Yep, my iPhone gets signal pretty much anywhere in Phoenix...
Anywhere ACCEPT MY APARTMENT COMPLEX!!!
5 bars at the streetlight, as soon as I pull in my complex, 1 bar... searching... No Service...
It will blip signal at times, but as a standard, 1 conversation will drop at least 4 calls, and texts take up to an hour or two to show up...
I went to the ATT store to see what the problem was, and I was directed to an ATT App called: "ATT Mark The Spot"
Its a free ATT app that you can use to send ATT a message saying what the problem is you have, and how frequently it happens. You'll then get a text message reply saying they recieved it. The idea being when they get enough responses in a certain area that they'll look more closely at their coverage and where to position new towers. Not that its an immediate fix, but it gives that cover of them trying to make things better...