Thistechniquenot onlyresolves the problemof "mobilecommunicate" in mobilesystem, but alsoprovidesagooddirection for applyingradio communicationnetworksynthetically in the future.
You can use that one mobile tool to communicate with whoever you want, as long as you have their cell phone number, and they don't need to be logged in to a site or service at that time to receive your message.