Iphone5 att bad signal problems?

Recently got a iphone5… Nothing but problems (signal wise). Is this a common issue? I'm on the ATT network, but have foound that most everyone with a iphone5 has been having similar probs… Att changed out my sim card twice thinking it would help. But nothing

You may want to think about returning your phone and getting a different phone with a different provider. AT&T does not have the best service where I live.

Is the phone locked to at&t? If is not can try a different sim froma friend (tmobile for example) to verify what is causing the problem the sim and network or the phone. A method that might help is to reset carrier settings and do a firmware update or restore.