Yes it has a speaker so you turn the bezel to answer a call etc.
My my colleague has one of these and makes and takes calls with it although he has commented that he feels like Michael Knight speaking to Kitt from Knighrider. Lol.
Youll just need need to set things up in the Samsung Gear App on your phone.
Although from an american network this tutorial may help a little.
From a review...
”Can you finally leave your smartphone at home? With its own LTE, heart-rate monitor, Wi-Fi and GPS — not to mention mobile payments and voice control — the Samsung Gear S3 Frontier is the first smartwatch that promises a fully untethered experience. This timepiece also happens to be gorgeous and pretty durable. And yet the 4G execution and app ecosystem aren't quite where they need to be.”
From a tutorial online > Set up Watch as Standalone or Pair to phone.
Current Phone ~
Samsung Note 20 Ultra 5G SM-9820 _256Gb SnapDragon 865+
Samsung One Ui 2.5/ Android 10.