Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band {, e.g. by time division } with signal insertion during the vertical blanking interval {only} the inserted signal being digital
Systems for the simultaneous or sequential transmission of more than one television signal, e.g. additional information signals, the signals occupying wholly or partially the same frequency band {, e.g. by time division } with signal insertion during the vertical blanking interval {only} the inserted signal being digital