The FCC plans to kick off an auction of spectrum in the 2.5 GHz band for a date in July, FCC Chair Jessica Rosenworcel told attendees in an address at Mobile World Congress in Barcelona today. According to the FCC website, the band includes 117.5 MHz of spectrum and the commission has assigned the number 108 to the auction.
The spectrum is considered mid-band, which stakeholders see offering the optimum mixture of speed and coverage for 5G services. The spectrum was allocated for educational purposes decades ago but has not been widely used. Some educational entities leased their spectrum to Sprint and other wireless service providers. The Sprint licenses transferred to T-Mobile when T-Mobile acquired Sprint, which some would argue gives T-Mobile a 5G spectrum advantage over other wireless carriers.
In 2019, the FCC estimated that the spectrum was unused in about half the country, including many rural areas. In an order adopted that year, the commission said licenses would be auctioned by county and that up to three licenses, ranging in size from 17.5 MHz to 50.5 MHz, would be available in each county.
At that time, the commission gave Tribal nations one year to request licenses for vacant spectrum in the band in tribal areas. Since then, the commission has awarded at least 259 licenses to Tribal nations that requested them.

An inventory of spectrum available for the auction is available at this link.
According to Rosenworcel, the 2.5 GHz band is “the single largest swath of contiguous mid-band spectrum we have below 3 gigahertz and the airwaves available in this auction are going to help extend 5G beyond our most populated areas.”
She added that after the 2.5 GHz auction date, the FCC also plans to work with federal partners to open up “the next tranche of mid-band spectrum in the 3.1-3.45 GHz band.”