Radio emissions can be tuned almost exactly by frequency; this is how tuning an AM/FM radio works. Most applications also have more-or-less exclusive access to

Radio emissions can be tuned almost exactly by frequency; this is how tuning an AM/FM radio works. Most applications also have more-or-less exclusive access to their band. All of the regulation that the FCC does is mainly to prevent interference between users and fairly consider the needs of all lobbyists when allocating bands.