Ok, sim cards are what the device uses to connect to LTE services. For Canada, Bell, telus and rogers are the big players, in the states, at&t, T mobile and a few others. I am using telus as my mobility service provider. My basic plan is 5 dollars a month per tablet, and as I use data per month, I pay for what I use. The point of doing this is that I have my tablets fully connected anywhere there is mobile service. This is great for when we are camping close to mobile towers so we can having our weather, news, travel plans all at our fingertips.