3/4ths of the U.S. won't even be available in the highly touted 28 GHz auction. There is essentially no spectrum available in the crucial 28 GHz spectrum band in the top 50 markets.
Verizon controls 76% of the 28 GHz band in the top cities (The red in the chart.) TMO has 12% and another 10% is spoken for. Only 2% will be available for auction. Verizon has 46% of the 39 GHz band and AT&T 30%.
Stephen Wilkus, a veteran of Bell Labs and Alcatel-Lucent, calculates the 28 GHz auction will only cover 23.7% of the U.S. population. Much will be rural, inappropriate for the short reach of mmWave. .