Since I’ve diversified my research interests beyond communications, I kind of lost track of what has been happening in cognitive radio. Via Kevin Drum I learned of another proposed FCC auction of broadcast spectrum in the 600-700 MHz range. Apparently there’s a political debate over how wide the guard bands should be. On the one side, wide guard bands prevent more spectrum from being auctioned off, and on the other, they may allow for some municipalities to put in services operating in those bands (?)
I never thought I would see the day when the sharpness of your bandpass filter would become a political issue, but there you have it.