When you’re shopping for a smartphone, you likely put little thought into the radios that receive your signal. The reason: they’re all about the same, and pretty good at their job. You do fret over carrier strength in your area, though. Is AT&T stronger than Verizon, or is T-Mobile the better choice? You can check Open Signal, which is helpful for you, but what about the carrier? A new Apple patent could give carriers real-time info on their towers, including dropped signals.