Both carriers have announced that they're field-testing LTE-LAA (LTE License Assisted Access) that promises hundreds of megabits per second by combining open 5GHz wireless with licensed airwaves. In practice, that could deliver performance better than your internet connection at home. AT&T's San Francisco test managed a brisk 650Mbps, while T-Mobile's Los Angeles experiment has reached an even quicker 741Mbps.

It'll likely be a while before you see LAA in real life. Remember, AT&T's existing faux 5G service is barely up and running -- it's going to take longer before a faster technology is ready for American networks. And that's not including the need for manufacturers to hop aboard. Still, both tests are promising. Just as sped-up 3G made it easier to wait for LTE rollouts several years ago, LTE-LAA could give you a taste of 5G-like speeds while you wait for true 5G to reach your city.