DVB-T and ISDB-T already fix the main problem...

The whole issue with adjacent TV transmitters wasting spectrum by having to transmit on different frequencies is already addressed by single frequency network support in the DVB-T and ISDB-T standards. In principle, all countries which use these standards can efficiently pack all of their terrestrial TV broadcasting into a well defined chunk of spectrum - eliminating the need for location based white space detection altogether. Of course the US decided to use ATSC instead, so that's not a solution that's open to them...