Hey there, thanks for asking! 4G LTE standalone connectivity is only available on Samsung Galaxy Watch Active2 LTE version. This model only has Bluetooth connectivity. Standalone voice calling on LTE versions require initial pairing with an eligible Samsung Galaxy device and a separate qualifying wireless plan. Your carrier may not support standalone voice calling, or support it may be available only in certain areas. Please check with your carrier for more information regarding wireless service plan for cellular service. Standalone functionality is limited if paired phone is not powered on or connected to a wireless network. ^Elizabeth