INTERDICTION METHOD AND APPARATUS WITH FREQUENCY CHANGE INHIBIT FUNCTION

摘要

An off-premises method and apparatus for the interdiction of unauthorized channels of a broadband cable television signal. The subscriber module is based on a sequential state machine (432) which loads frequency control words corresponding to the jammed channels from a frequency control memory (404) into each latch (406-412) on a cyclic basis. In addition, according to one illustrated implementation, the loading of frequency control words to the latches (406-412) in the sequence can be inhibited without changing the words in the memory. The sequential state machine (432) will then in effect skip the deauthorized frequency control words and produce jamming signals at the previous frequencies. This provides flexibility in the system for either jamming or unjamming a specific channel to a subscriber for short periods of time. This allows a simple authorization and deauthorization technique (428) without having to reload the frequency control memory or recalibrate a frequency control word for the specific channel selected.