Keep getting 'No Service' with ATT

[ImMikeW]

Today in class I suddenly dropped from 4/5 bars to no bars, and then to no service. The person next to me who also had an iPhone had full bars with 3G. Its been about 4 hours later and I still have no service. I have been able to get it for a couple of seconds at a time but besides that nothing.

I have tried, powering off and rebooting multiple times, reset it (hold home and power button down till screen flashes), I have turned it off and taken the SIM card out, I have switched it between airplane mode a few times, and with everything I've tried, nothing. Any ideas as to what I can do to make this work?

[Poseidon79]

DFU Restore and try it stock. If you still have issues then your antenna is failing. Warranty time.