As great as it sounds to have nationwide 5G in the U.S., the real joy comes when you find yourself in an area served by mid-band or mmWave signals. Verizon, T-Mobile, and AT&T use low-band spectrum in order to cover the majority of the U.S. because these signals travel far and can penetrate structures. But the one thing they cannot do is deliver the kind of 5G download data speed that you’ve been hearing about in terms of powering self-driving cars, downloading feature-length films in seconds, and more.