Smart watches on Android Wear received support for 3G and LTE
Currently, only one model of smart watches on Android Wear supports LTE: this is the second generation LG Watch Urbane.

Thanks to the Android Wear update, you can expect a large number of new devices. Users will have to buy a separate SIM card for the device and spend extra money on mobile Internet - mobile operators will be happy with this.
Peter Ludwig, Android Wear Manager, wroteon the blog on Wednesday: “No more worrying about Bluetooth or Wi-Fi - your watch will automatically switch to the mobile network when it’s out of the coverage area of your smartphone’s signal.”
“As long as your watch or phone is connected to the mobile Internet, you can use the watch to send or receive messages, send data about sports, receive answers from Google and launch your favorite applications. And yes, you can even make or receive calls right from the clock if your hands are busy or your phone is far away, ”adds Ludwig.
Now you must ask the question: "There is Samsung Gear S with 3G." But these smart watches of the Korean company work on the Tizen operating system . Apple watch, released in April and running on watchOS, do not yet support cellular communications.