advanced compatible television (ACTV) an extended definition television system that can operate with existing bandwidths on ex- isting receivers and is compatible with the NTSC broadcasting system. The ACTV sys- tem was proposed by the Advanced Televi- sion Research Consortium and was the first high definition television (HDTV) system. HDTV system was tested by the FCC July 17, 1992. The additional picture information needed to increase the picture width and to increase the resolution to the HDTV format is transmitted in an augmented channel as an alternative to simulcast transmission. See Advanced Television Research Consortium
