Not all radio transmissions are prohibited in the core of the Quiet Zone. For example, emergency service (police, fire, and ambulance) radios and CB radios are permitted. However, large transmitter owners must typically coordinate their operations with the Green Bank Observatory. The only broadcast radio stations are part of the Allegheny Mountain Radio network, with just one station in the AM band, and several low-power FM broadcast translator stations. Exceptions to restrictions are usually determined on a case-by-case basis, with preference given to public safety concerns, such as remote alarm systems, repeaters for emergency services, and NOAA Weather Radio.