Hello Mike, thanks for asking! Samsung smartwatches are available in two versions: Bluetooth and LTE. The LTE version can receive calls and messages without being connected to a phone. However, you'll first need to activate service for your watch through the same carrier as your mobile phone. Don't worry, AT&T, Sprint, T-Mobile, and Verizon all offer plans for the LTE versions of Galaxy Watch and Gear S3. Plans and connection method may vary depending on the carrier. ^Elizabeth