Ingress monitoring system and method

A system for monitoring reverse paths of a bi-directional cable communication network to detect and analyze an ingress signal entering and carried by one of said reverse paths within a frequency band assigned thereto for carrying reverse signals, said ingress signal carrying path ending at a network sub-headend or headend through a corresponding one of a plurality of communication lines connected thereto, said system comprising:

• a plurality of radio frequency signal detectors being provided with bandpass filter means and respectively coupled to said plurality of communication lines at said sub-headend or headend for receiving a radio frequency signal within said frequency band to generate corresponding output signals indicative of the strength of the received radio frequency signal, one of said frequency signal detectors being coupled to the communication line corresponding to the ingress signal carrying path for receiving the ingress signal with said reverse signals to generate corresponding one of said output signals which is indicative of the strength of the received ingress signal with said received reverse signals wherein each said radio frequency signal detector includes:
• an amplitude level detector circuit coupled to said bandpass filter means for generating an amplitude level signal for any said received frequency signal;
• an amplitude level comparator circuit comparing the amplitude level signal with a predetermined amplitude threshold to generate an integrator control signal whenever the amplitude level signal exceeds the amplitude threshold;
• an integrator circuit for integrating the amplitude level signal according to the integrator control signal to generate as one of said strength indicative signals a first output signal indicating an integrated value for the amplitude level signal over a time during which the amplitude level signal exceeds the amplitude threshold;
• and
• a further integrator circuit for integrating the amplitude level to generate as one of said strength indicative signals a second output signal representing an integrated value for the amplitude level signal;
• signal processor means adapted to perform selective analysis of the detector output signals by extracting source characteristics data from said detector output signals over a predetermined period of time and comparing said source characteristics data with at least one predetermined ingress thresholds to generate an alarm signal whenever the ingress signal is detected wherein said signal processing means for analyzing the detector output signals derive a ratio of the first and second output signals for comparing thereof with said one or more predetermined ingress thresholds to generate said alarm signal whenever the ingress signal is detected;
• controller means receiving the alarm signal to generate monitoring sequence control data indicative of the communication line corresponding to the ingress signal carrying path to be monitored:
• switch means having a plurality of inputs being connected to the communication lines and being responsive to the monitoring sequence control data to select the input connected to the communication line to be monitored;
• and
• signal monitor means coupled to an output of the switch means and being responsive to the monitoring sequence control data for analyzing the ingress signal.

A system for monitoring reverse paths of a bi-directional cable communication network to detect and analyze an ingress signal entering and carried by one of said reverse paths within a frequency band assigned thereto for carrying reverse signals, said ingress signal carrying path ending at a network sub-headend or headend through a corresponding one of a plurality of communication lines connected thereto, said system comprising:

• a plurality of radio frequency signal detectors being provided with bandpass filter means and respectively coupled to said plurality of communication lines at said sub-headend or headend for receiving a radio frequency signal within said frequency band to generate corresponding output signals indicative of the strength of the received radio frequency signal, one of said frequency signal detectors being coupled to the communication line corresponding to the ingress signal carrying path for receiving the ingress signal with said reverse signals to generate corresponding one of said output signals which is indicative of the strength of the received ingress signal with said received reverse signals wherein each said radio frequency signal detector includes:
• an amplitude level detector circuit coupled to said bandpass filter means for generating an amplitude level signal for any said received frequency signal;
• an amplitude level comparator circuit comparing the amplitude level signal with a predetermined amplitude threshold to generate an integrator control signal whenever the amplitude level signal exceeds the amplitude threshold;
• an integrator circuit for integrating a portion of the amplitude level signal above the amplitude threshold according to the integrator control signal to generate as one of said strength indicative signals a first output signal indicating an integrated value for the amplitude level signal portion over a time during which the amplitude level signal exceeds the amplitude threshold;
• and
• a further integrator circuit for integrating the amplitude level to generate as one of said strength indicative signals a second output signal representing an integrated value for the amplitude level signal;
• signal processor means adapted to perform selective analysis of the detector output signals by extracting source characteristics data from said detector output signals over a predetermined period of time and comparing said source characteristics data with at least one predetermined ingress thresholds to generate an alarm signal whenever the ingress signal is detected wherein said signal processing means for analyzing the detector output signals derive a ratio of said first and second output signals for comparing thereof with said one or more predetermined ingress thresholds to generate said alarm signal whenever said ingress signal is detected;
• controller means receiving the alarm signal to generate monitoring sequence control data indicative of the communication line corresponding to the ingress signal carrying path to be monitored:
• switch means having a plurality of inputs being connected to the communication lines and being responsive to the monitoring sequence control data to select the input connected to the communication line to be monitored;
• and
• signal monitor means coupled to an output of the switch means and being responsive to the monitoring sequence control data for analyzing the ingress signal.

A system for monitoring reverse paths of a bi-directional cable communication network to detect and analyze an ingress signal entering and carried by one of said reverse paths within a frequency band assigned thereto for carrying reverse signals, said ingress signal carrying path ending at a network sub-headend or headend through a corresponding one of a plurality of communication lines connected thereto, said system comprising:

• a plurality of radio frequency signal detectors being provided with bandpass filter means and respectively coupled to said plurality of communication lines at said sub-headend or headend for receiving a radio frequency signal within said frequency band to generate corresponding output signals indicative of the strength of the received radio frequency signal, one of said frequency signal detectors being coupled to the communication line corresponding to the ingress signal carrying path for receiving the ingress signal with said reverse signals to generate corresponding one of said output signals which is indicative of the strength of the received ingress signal with said received reverse signals;
• signal processor means adapted to perform selective analysis of the detector output signals by extracting source characteristics data from said detector output signals over a predetermined period of time and comparing said source characteristics data with at least one predetermined ingress thresholds to generate an alarm signal whenever the ingress signal is detected;
• an amplitude level detector circuit coupled to said bandpass filter means for generating an amplitude level signal for any said received frequency signal;
• a peak-and-hold detector circuit receiving the amplitude level signal for generating as a first one of said strength indicative signals a first output signal representing a peak value for said received frequency signal;
• an amplitude level comparator circuit comparing the amplitude level signal with a predetermined amplitude threshold to generate an integrator control signal whenever said amplitude level signal exceeds the amplitude threshold;
• a first integrator circuit for integrating the amplitude level to generate as a second one of said strength indicative signals a second output signal representing an integrated value for the amplitude level signal;
• a second integrator circuit for integrating a portion of the amplitude level signal above the amplitude threshold according to the integrator control signal to generate as a third one of said strength indicative signals a third output signal representing an integrated value for the amplitude level signal portion over a time during which the level signal exceeds the amplitude threshold;
• a third integrator circuit receiving the integrator control signal to generate as a fourth one of said strength indicative signals a fourth output signal representing a cumulative time during which the level signal exceeds the amplitude threshold;
• a fourth integrator circuit for integrating the amplitude level signal according to the integrator control signal to generate as a fifth one of said strength indicative signals a fifth output signal representing an integrated value for the amplitude level signal over a time during which the level signal exceeds the amplitude threshold.

A method of monitoring reverse paths of a bi-directional cable communication network to detect and analyze an ingress signal entering and carried by one of said reverse paths within a frequency band assigned thereto for carrying reverse signals, said ingress signal carrying path ending at a network sub-headend or headend through a corresponding one of a plurality of communication lines connected thereto, said method comprising the steps of:

• detecting the reverse signals at said sub-headend or headend and taking at least two different types of measurements of said reverse signals over a predetermined period of time to generate source characteristics data;
• analyzing the source characteristics data through comparison with at least one predetermined ingress thresholds to generate an alarm signal whenever the ingress signal is detected;
• processing the alarm signal to generate monitoring sequence control data indicative of the communication line corresponding to the ingress signal carrying path to be monitored;
• selectively monitoring said ingress signal communication line according to the monitoring sequence control data;
• analyzing the ingress signal according to the monitoring sequence control data;
• comparing ingress signal analysis data generated at said monitoring step with predetermined threshold data to generate alarm message data;
• generating diagnostic sequence control data according to the alarm message data;
• and
• determining source characteristics of the ingress signal according to the diagnostic sequence control data.