Stands for Digital Video Broadcasting, and is defined as the European standard fot Digital Television. Also the name of the group that sets this standard, created in late 1993.
There are also in comercial use and implementation the American ATSC system, and the Japanese ISDB. All three standards allow for multiple video and audio
signals to be multiplexed in a program stream.
DVB uses the MPEG-2 standard for video and audio compression, MPEG standards for multiplexing, and a
variety of standards for transmission, according
to the medium of the transmission.
The main specifications are:
-
DVB-T for terrestrial broadcasting, using the COFDM modulation. Operating in UK since
December 2000.
-
DVB-C for cable broadcasting, with QAM modulation.
-
DVB-S for satellite based broadcasting using QPSK
modulation.
-
DVB-MC and DVB-MS for microwave broadcasting
above and under 10 Ghz frequency, respectively, using
QAM and QPSK modulations.
The DVB standard also allows an hierarchical transmission scheme, in which a main video signal is transmitted with
more or less priority than others, becoming more or less
error prone, and consuming more or less bandwidth
according to the priority assigned to it in the program stream.