I have recently purchased my first Android (Galaxy s2 skyrocket) and I've been having problems with my call signal. When I go to work every morning, I have to ride the train for about an hour which goes into a tunnel for about 30 minutes. When I reach my destination and come out from the train station (which is underground), my phone claims to have signal and data but I can not make any calls, can't text, cant use the internet until I shut my phone down and turn it back on. Also, when I talk to people on the phone, they tell me that my voice gets super quiet sometimes and I know its not me because I never had that problem with my old phone. Any help would be appreciated. Thank you in advance.