You can use LTE network of your service provider, and you can use the iPhone to connect to the Internet through the network (iPhone 5 or a newer version. There are no available all areas) See setting up cellular
You can use the LTE network provider you have. And you can use your iPhone to connect to the Internet through a network that (iPhone 5 or later. Not available in all areas) looks set Cellular.
You can use the network LTE of your provider, you can use iPhone to connect to the Internet through the network. (iPhone 5 or newer version. Not to use in all areas). Set cellular