Astra Digital Radio definition audioDigital Radio
over satellite, compatible with analog television transmissions. Alternatively the normal TV subcarriers can be modulated by a MPEG-1 Layer-2 48 kHz 192 kbps signal. Quality is better than analog carriers and only needs half the bandwidth
(analog stereo = 2 carrier, digital stereo = 1 carrier). Quality is limited and the data rate can't be increased.