Digital System DH, also known as the hybrid satellite/terrestrial WorldSpace system, is designed to provide satellite digital audio and data broadcasting for vehicular, fixed and portable reception by inexpensive common receivers.
ITU-R BS.1114-9-2015 Referenced Document
ITU-R BS.774 Service requirements for digital sound broadcasting to vehicular, portable and fixed receivers using terrestrial transmitters in the VHF/UHF bands
ITU-R BS.1114-9-2015 history
2015ITU-R BS.1114-9-2015 Systems for terrestrial digital sound broadcasting to vehicular, portable and fixed receivers in the frequency range 30-3 000 MHz