Try turning it OFF. Wait a few, and then turn it back on again. For whatever reason, it is just not finding the carrier signal. I have AT&T, and I live in a fairly remote area. I lose connection with the carrier all of the time, and see that my phone is searching, searching, searching. Since that drives me basically crazy, I do the turn off and back on. Sometimes I set it to Airplane mode and then turn Airplane mode back off. Usually one of those results in it finding the signal.
If it still doesn't find it, you might try calling Verizon to see if it is an issue on their end, or take it into your local Apple Store or Apple Distributor, and have them take a look.
Hope this helps, and that one of the "easy" solutions work for you!