OPTIMUM AMPLITUDE AND FREQUENCY OF JAMMING CARRIER IN INTERDICTION PROGRAM DENIAL SYSTEM

摘要

Off-premises cable television interdiction apparatus comprises a microprocessor actuation and control means (300) for actuating and controlling one or more frequency agile voltage controlled oscillators (341-344). The voltage controlled oscillators (341-344) selectively jam only unauthorized premium programming transmitted in the clear from a headend to a particular subscriber. Each voltage controlled oscillator (341-344) is allocated a continuous band of frequencies consistent with the elimination of jamming signal frequency harmonics which may disturb authorized programming at a higher channel frequency. The microprocessor actuation and control means (300) provides a calibration mode and a normal mode of operation. The method of interdiction comprises the steps of generating and storing voltage control words for operating the oscillators consistent with a headend selected jamming factor for a particular channel to be jammed and addressably transmitting and storing premium programming authorization data. An optimum frequency amplitude window for the jamming signal is disclosed.