But isn't the SIM card supposed to work with the cell tower software? Isn't it more the job of the removable SIM card and not the actual phone itself? Sure, the phone sends out the messages using the hardware, the actual physical parts inside the phone, but isn't the SIM card supposed to have the ability to talk to whichever towers they were designed to talk with? I mean, are some phones talking to cell phone towers without the SIM cards? When I take out my SIM card, I can't talk to the towers or is there a way to still talk to towers without the SIM cards? I use Ubuntu Mate 16.04. Version 6.04 is before my time. I started using Ubuntu around version 8 or 9. But Ubuntu has been improving since then. Now, it is at version 20.