I'm on t-mobile and never have any trouble with signal...always 3g...always full strength! That being said a couple of weeks ago I had some problems as t-mobile were 'improving the network in my area'...for about 3 days signal was a bit hit and miss and my battery wouldn't even last a day as it was constantly searching for network! It's all sorted now though...and t-mobile did send me a text a few days before warning of the upcoming problems! Maybe call them and see if the same thing is going on in your area at the moment? Hope this helps!