Commercial stations may own their translators (or boosters) when the translator (or booster) is in the parent station's primary service contour; they can only fill in where terrain blocks the signal. Boosters may only be owned by the primary station; translators outside a primary station's service contour cannot be owned by (or receive financial support from) the primary station. Most translators operate by receiving the main station's on-air signal with a directional antenna and sensitive receiver and re-transmitting the signal. They may not transmit in the FM reserved band from 88 to 92 MHz, where only non-commercial stations are allowed. Non-commercial stations may broadcast in the commercial portion of the band, however. Unlike commercial stations, they can relay programming to translators via satellite if the translators are in the reserved band. Translators in the commercial band may only be fed by a direct on-air signal from another FM station (or translator). Non-fill-in commercial-band translators may not be fed by satellite, according to FCC rule 74.1231(b). All stations may use any means to feed a booster.