First, when I read this, I thought ITU wants to use short waves, which naturally propagate beyond line of site, only they are very tricky to use reliably. Plus very narrow band don't allow much data to be sent.
But actually they are dedicating 1087.7-1092.3 MHz for satellite service. I wonder if we already have satellite constellation up there that is able to receive that frequency band?
Original article:
United Nations News Centre - UN conference reaches agreement on radio spectrum for global flight tracking