The grand promise of 5G wireless service—connection speeds 10 times as fast as the speediest home broadband service—is slowly moving closer to reality. AT&T is launching its new 5G service Friday in 10 cities, including Los Angeles, San Francisco, and San Jose. Notably, the service is based on real 5G standards, unlike AT&T’s earlier "5G Evolution" offering, which in reality was just a variety of 4G.