LTE smart watch technology
If smart watches has LTE radios, it will automatically connect to the cellular network. You can use apps and receive and send messages, even if your phone is far away.
When someone calls your smart phone, your smart watch may also ring, and you can make or receive voice calls through its onboard microphone and speaker.
You can pair a smart watch that supports LTE with a wireless headset. For example, by pairing Apple Watch with Apple AirPods, you can use AirPods instead of Watchs microphones and speakers to play music and talk on the phone.