FM is short for frequency modulation, which refers to the means of encoding the audio signal on the carrier frequency. FM full power, low power , translator and booster stations operate in the 88 – 108 MHz band. There are many classes of radio stations. The smallest provide service to areas within three or four miles of a transmitter site; the largest provide service to locations more than 60 miles from a transmitter site. Only noncommercial educational radio stations are licensed in the 88-92 MHz “reserved” band. Both commercial and noncommercial educational stations may operate in the “non-reserved” 92-108 MHz band.