My Tab gets two to three bars in my room. I was using it online, surfing the Web, watching YouTube, etc.. I shut the screen off and left to go get lunch. When I returned, it had completely lost its 4G signal (bars grayed out and No sign instead of 4G with arrows). I checked my phone (a Galaxy S4 also on VZW) and it was getting its signal. Putting the Tab in airplane mode for 30 seconds resolved the problem. I'm simply curious as to what could've caused this. Why would the Tab lose its 4G and not the phone?