Network issues, including dropped calls, failed call attempts, and poor call quality, can occur for a number of reasons (even in a highly populated area)- including but not limited to:
Gaps in network coverage
A geographic obstruction, such as a mountain
A type of building construction
To minimize connectivity issues, we constantly monitor and optimize our network to deliver the best possible wireless service.
The other thing is, if you download the AT&T app Mark the Spot, you can mark the spots in the app by following the instructions so, we can implement enhancements.
If you cannot download the application, please go to the live chat or contact us from an alternate phone so, we can report this issue. We do take our network seriously as I work in the department that tracks this type of feedback. If it is reported to us either by the application or through chat or technical support, we will get our network team on it by, reporting this issue. Since it is highly populated, have your family and friends download and report too because the more the better!
I hope this helps!!!
*I am an AT&T employee and the postings on this site are my own and don't necessarily represent AT&T's position, strategies or opinions.