said by fgoldstein :

These were all PCS licenses, mostly C-block (a few Fs). NextWave bid crazy-high prices at the C-block auction in 1996 or so, and then defaulted before paying for them, declaring bankruptcy. It's a long, long story but this was part of the settlement. VZW picked up the rest of NextWave's remaining licenses last year in a private deal, I think with some of the money going to the FCC (well, the treasury really).