Once you’ve activated your iPhone with your carrier, it should continue to work on the cellular network without any problems as long as you’re within range of a tower. Nevertheless, the vagaries of ...

While most people seem to manage just fine with a single SIM card in their smartphone, some -- especially travelers, who can save money by fitting a local SIM card into their handset -- love the ...

A SIM card, or subscriber identity module, is a small card in your cellphone that connects you to the network. Your SIM card contains your phone number, and lets you make phone calls, send text ...

After you purchase and use your cellphone for an extended period of time, you can change networks. However, the phone that you're currently using may not be offered on that network. If you wish to ...

These two ways of connecting your phone to a cellular network are very different. We tell you about each and how you can switch from one to another. I started my career with CNET all the way back in ...