The shape of the 5G landscape in the US in 2020 and beyond is hard to predict until one decision is made – whether Sprint and T-Mobile USA will be allowed to merge. If they do, there will be a far bigger challenger for AT&T and Verizon, plus they will divest customers and spectrum to Dish Network and enable a fourth major 5G operator. Yet the outcome remains uncertain. The deal has passed most regulatory hurdles but faces a significant legal challenge from a group of 13 states, plus the District of Columbia, which some analysts believe will derail the transaction. That could spark many potential knock-on effects if appeals failed – a new buyer for Sprint and/or TMO, perhaps…