satellite digital audio radio service (SDARS)
1. A satellite-based direct-broadcast radio service in which digitally encoded audio entertainment material is broadcast to Earth-based receivers, either directly from an orbiting satellite, or–in cases in which the receiver is in a shielded location–from the satellite to the receiver via a repeater station.
2. A radiocommunication service in which audio programming is digitally transmitted by one or more space stations directly to fixed, mobile, and/or portable stations, and which may involve complementary repeating terrestrial transmitters, telemetry, tracking and control facilities. [47CFR]
3. A radiocommunication service in which compact-disc quality programming is digitally transmitted by one or more space stations. [47CFR]