Satellite DigitalAudio Radio Service (SDARS) are satellite-based broadcasting services via which digital audio is broadcast in North America directly from satellites or via a repeater station to receivers on Earth. Which signal the receiver receives depends on the reception conditions.
In cities, the reception of the SDARS signal is covered by the repeater stations. The receiving devices can be fixed, mobile or portable stations.
SDARS is transmitted in the S-band at 2.3 GHz, exactly between 2.32 GHz and 2.345 GHz. This frequency range was defined by the Federal Communications Commission( FCC) for broadcasting via satellites in the early 1990s.
SDAR services are carried in the U.S. by XM Satellite Radio, Sirius Satellite Radio and WorldSpace Satellite. These are CD-quality paid broadcast programs that, due to the satellites, can be received nationwide. Each operating company broadcasts over 100 radio channels in a wide variety of genres. In addition to music channels, there are entertainment, news, sports and special interest channels. All channels can be received nationwide from the east to the west coast in the same quality.