A:Answer Yes, you can use any cellular service or you can connect to Wifi to use it. Cellular service, regardless of the carrier, will work only if the location where you are receives a signal from a cellular tower. My own apartment, for example, does not receive a signal from any nearby tower. It’s a problem in some rural areas and also urban locations such as mine where the signal is blocked by certain kinds other structures. (I also receive very poor and spotty radio reception.) Therefore, I’m able to use my iPhone for everything except calls and text messages whenever the WiFi isn’t on.