answer:Sometimes what you’re seeing is the cell phone switching from one cell tower to another. Tower A gets further away and the phone switches to tower B. If that process goes wrong, the phone can’t hand off the call properly, so it drops out of service on tower A, then connects to tower B and reestablishes full service—but without your phone call. As for getting dropped from calls with full signal strength, that’s weird. Could be the other person’s phone, or you phone / service could be weird.