In 5G, the four US MNOs will not just be competing with one another. They will also have to face rising mobile and quad play strength among the largest cablecos. This is likely to be a justification for approving the proposed merger of Sprint and T-Mobile, but that enlarged third player may be less concerning to Verizon and AT&T than the combination of Charter and Comcast. The two biggest cable operators have both launched mobile services, via MVNO deals with Verizon, on top of their existing large base of WiFi hotspots and homespots. The latter enable them, like disruptors such as Free Mobile in France, to reduce their MVNO fees and other mobile network costs by offering WiFi-first deals to…