This definition implies the existence of
incumbent services, which have prioritized access to the spectrum
and whose signals should be protected from harmful interference
stemming from other whitespace-operating services.
An example of whitespaces are TV whitespaces (TVWS),
which are portions of the frequency spectrum made available
after the digital TV switchover in the UHF/VHF spectrum in
certain geographical locations. To protect incumbent services
of the UHF/VHF spectrum, such as Digital Video Broadcasting