Glossary 121FCC Federal Communications Commission, anindependent United States governmentagency that regulates interstate andinternational radio communications.LLED Light Emitting Diode, a device that is able toemit light.Mmute A mute controls the circumstances underwhich a received signal is passed to the radio’sspeaker. For example, when a signal isreceived by the radio, the mute may remain‘closed’ if the signal is not strong enough,does not have valid signaling or is encrypted.PP25 Project 25. The Association of Public SafetyCommunications Officials (APCO) establishedProject 25 (P25). This project was led byUnited States Federal, state, and localgovernment representatives to developstandards for interoperable digital radios andsystems to meet the needs of public safetyusers. See http://www.project25.org forfurther information.Rrepeater A repeater is a relaying site, usually situatedabove a city or town. The repeater extendsthe range of radio communications byreceiving and re-transmitting signals receivedfrom radios.