Iphone 4s says no service! D

Okay, so my iphone 4s says no service usually it says AT&T 4G and it shows the bar sign but today it didn't, this is my first time experiencing this complication. In the morning when i was in school, everything was fine and i used the internet to look for information about a book and in my biology class never has signal so sometimes my phone says no service but later on it continued to say no service, I looked at my friends iphone 4s and she has AT&T too and she had 4G. I tried everything i turned off my Wi-Fi then turned it back on, i turned off the cellular data and turn it back on, i put it on airplane mode then turned it off, it said it was searching but then it said no service. I've had this phone since april so its not that old. Although, my lock/power button is broken, i don't know how but when i pressed it, i was unable to. I can't call or text and i really need it for school. I'm going to take it to the AT&T store but for now is there anything I can do? Oh, also i can't reboot it because my lock button is broken and i'm scared to restore it because what if I need to turn on my iphone?

Not surprising. There's a really high chance that it is not your iphone that is the issue.at&t has been rated worse cell provider again so chances are they are just experiencing some down time. I wouldn't be worried too much about it right now. Just try to wait it out.wait for a day at least to see if the problem is fixed. Also go to some place high where there's less chance of disturbance and see if you can get a signal.otherwise, you gotta contact at&t.