Subscriber terminal for monitoring radio-frequency signal ingress into cable television systems
First Claim
1. A subscriber terminal for connection to a headend by means of a cable, said terminal comprising means including first receiver means for monitoring and detecting the presence of at least one radio-frequency ingress signal on said cable, second receiver means connected to said cable for receiving coded signals from the headend, said coded signals including an ingress-frequency select signal and a return frequency command signal, means connected to the cable for transmitting a return signal to the headend at a specified return frequency, and control means operatively connected to said transmitting means and to said first and second receiver means and effective in response to said ingress-frequency select signal and return frequency command signal received from the headend, to select the frequency of said at least one ingress signal which said first receiver means is to monitor and detect, to code said return signal to represent information concerning the detected ingress signal and to control the transmitting means to transmit said return signal at said specified return frequency.
1 Assignment
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Accused Products
Abstract
A cable television subscriber home terminal capable of transmitting information along a cable to a central station at one of a series of predetermined return frequencies includes a receiver tuned to monitor possible ingress into the system at selected frequencies within the range of the return system frequency. A signal representing the magnitude and frequency of the detected ingress signal modulates a return signal, which is transmitted along the cable system to the headend to provide information concerning the detected ingress signal.
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Citations
8 Claims
- 1. A subscriber terminal for connection to a headend by means of a cable, said terminal comprising means including first receiver means for monitoring and detecting the presence of at least one radio-frequency ingress signal on said cable, second receiver means connected to said cable for receiving coded signals from the headend, said coded signals including an ingress-frequency select signal and a return frequency command signal, means connected to the cable for transmitting a return signal to the headend at a specified return frequency, and control means operatively connected to said transmitting means and to said first and second receiver means and effective in response to said ingress-frequency select signal and return frequency command signal received from the headend, to select the frequency of said at least one ingress signal which said first receiver means is to monitor and detect, to code said return signal to represent information concerning the detected ingress signal and to control the transmitting means to transmit said return signal at said specified return frequency.
Specification