Carrier Update Files (.ipcc)
These are carrier update files directly from Apple servers (You can feel free to check the url). You can install these updates manually to your device using this guide.
These carrier update files are for users who would like to take advantage of their carrier’s new features without having to update their iOS version. Some updates may not be compatible without a mandatory iOS update (Ex. Trying to install a iOS 10 carrier update file on iOS 8.).