You can also try turning off the automatic connections. Visit carrier setting and on its upper portion you will notice “Automatic” option. Now tap it for the purpose of removing the checkmark beside it. Once you do such, it means you have already disabled it. This is considered as one of the most effective ways of your iPhone from connecting automatically to the home service provide once you are abroad. It will also stop you from using the iPhone 5s unlimited data or if you use iPhone 6, then the same thing.