The watch pairs up to the phone via Bluetooth to make calls.
In regards to the Lte version.
"Leave your phone behind.
4G LTE connectivity uses your mobile data plan so you can send texts, get emails, receive notifications and even make calls all without your phone.1" from Samsung gear-s3.
Daily Driver > Samsung Galaxy s²² Ultra 256Gb in Phantom Black.
The advice I offer is my own and does not represent Samsung’s position.
I'm here to help. " This is the way. "