ETSI Satellite Digital Radio
ETSI Satellite Digital Radio (SDR or ETSI SDR) describes a standard of satellite digital radio. It is an activity of the European standardisation organisation ETSI. It addresses systems where a satellite broadcast directly to mobile and handheld receivers in L band or S band and is complemented by terrestrial transmitters.
Source: Wikipedia — ETSI Satellite Digital Radio (CC BY-SA 4.0)