The US MNOs no longer have to worry only about the competition from one another in the 5G era. They are facing challenges from new entrants to the mobile space. Dish Network plans a national 5G build-out enabled by divestments of spectrum and customers from Sprint (assuming its merger with T-Mobile finally goes through). And more dangerously, the major cable operators plan to build on their existing services, based on MVNO deals and WiFi, by launching their own cellular networks in selected areas. The two largest cablecos, Comcast and Charter, are particularly ominous for the MNOs, since they have a far-reaching collaboration deal ranging from R&D to roaming to cross-marketing. If other cable firms were to join, these regionally-based operators…