The 28GHz band millimeter band is the first high-band auction by the FCC, which will be followed directly by a 24GHz auction. Millimeter waves, 28GHz or 39GHz, can deliver multi-megabit or gigabit per second speeds but only over 1,000 to 2,000 feet. The FCC now has 109 open 28GHz licenses left to auction, out of 3,072 total licenses.
The agency has previously said that it would continue with auctioning spectrum licenses and clearing bandwidth for mobile operators to use, despite the shutdown. (See 5G Auction Carries On Despite US Government Shutdown.)
Still, some parts of the FCC are now closed. The experimental OET licensing site, for instance, now sends you to
It's not clear what the lack of a test/trial licensing will mean for 5G in the US (for the time being).
— Dan Jones, Mobile Editor, Light Reading