Ingress monitoring system and method

• US 7,254,827 B1
• Filed: 05/08/2000
• Issued: 08/07/2007
• Est. Priority Date: 05/08/2000
• Status: Expired due to Term

• Current Assignee: VeEX Incorporated
• Original Assignee: Sunrise Telecom Incorporated
• Inventors: Terreault, Gérard
• Primary Examiner(s): Beliveau; Scott E.
• Assistant Examiner(s): SHELEHEDA, JAMES R
• Application Number:
  US09/567,085
• Time in Patent Office: 2,647 Days
• Field of Search: 725106-107, 725125-128, 725/121, 725/124, 725/112, 348/192, 348/198, 348/180
• US Class Current: 725/125
• CPC Class Codes: H04N 17/00 Diagnosis, testing or measuring for television systems or their details

Abstract

A system for monitoring reverse paths of a bi-directional cable communication network such as a CATV network, to detect and analyze ingress signals entering a reverse path and ending at a network sub-headend or headend through a corresponding one of communication lines, comprises a plurality of radio frequency signal detectors connected thereto. The radio frequency signal detectors are provided with bandpass filter for receiving a radio frequency signal within the frequency band used, to generate corresponding output signals indicative of the strength of the received radio frequency signal. The output signal generated by the frequency signal detector which is coupled to the communication line corresponding to the ingress signal carrying path is indicative of the strength of the received ingress signal with received reverse signals. The system further comprises a signal processor for analyzing the detector output signals through comparison with one or more predetermined ingress thresholds to generate an alarm signal whenever the ingress signal is detected. The system further comprises a control computer 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. The system also comprises a selector switch 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 monitoring instrumentation such as a spectrum analyzer and a broadband analyzer coupled to an output of the switching device and being responsive to the monitoring sequence control data for analyzing the ingress signal and generating alarm message data accordingly. The control computer receives the alarm message data to further generate diagnostic sequence control data for the monitoring instrumentation also used to determine source characteristics of the ingress signal.

Claims

1. 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;

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 wherein said signal monitor means include signal analyzer means for generating ingress signal analysis data and data processor means receiving said monitoring sequence control data to control operation of said analyzer means and comparing the ingress signal analysis data with predetermined threshold data to generate alarm message data, said controller means receiving the alarm message data to further generate diagnostic sequence control data according to the alarm message data, said signal monitor means being further responsive to the diagnostic sequence control data to determine source characteristics of the ingress signal.

2. The system according to claim 1, wherein said signal analyzer means comprise a 10 frequency scanning signal spectrum analyzer for generating ingress signal spectral analysis data.

3. The system according to claim 2, wherein said data processor means include local data processor means associated with said frequency scanning signal spectrum analyzer, said monitoring sequence control data including spectral monitoring sequence control data, said predetermined threshold data including spectral-related threshold data, the local processor means receiving the spectral monitoring sequence control data for comparing said ingress signal spectral analysis data with the spectral-related threshold data to generate spectral-related alarm message data included in said alarm message data, the diagnostic sequence control data including spectral diagnostic sequence control data.

4. The system according to claim 2, wherein said signal analyzer means further comprise a sampling broadband signal analyzer for generating ingress signal broadband analysis data.

5. The system according to claim 4, wherein said data processor means include first and second local data processor means respectively associated with said frequency scanning signal spectrum analyzer and said sampling broadband signal analyzer, said monitoring sequence control data including spectral monitoring sequence control data and broadband monitoring sequence control data, said predetermined threshold data including spectral-related threshold data and broadband-related threshold data, the first and second local processor means respectively receiving the spectral monitoring sequence control data and the broadband monitoring sequence control data for comparing the ingress signal spectral analysis data and the ingress signal broadband analysis data respectively with the spectral-related threshold data and the broadband-related threshold data to generate spectral-related alarm message data and broadband-related alarm message data included in said alarm message data, the diagnostic sequence control data including spectral diagnostic sequence control data and broadband diagnostic sequence control data.

6. The system according to claim 1, wherein said signal monitor means include a sampling broadband signal analyzer for generating ingress signal broadband analysis data.

7. The system according to claim 6, wherein said data processor means include local data processor means associated with said sampling broadband signal analyzer, said monitoring sequence control data including broadband monitoring control sequence data, said predetermined threshold data including broadband-related threshold data, said local processor means receiving the broadband monitoring sequence control data for comparing the ingress signal broadband analysis data with the broadband-related threshold data to generate broadband-related alarm message data included in said alarm message data, the diagnostic sequence control data including broadband diagnostic sequence control data.

8. The system according to claim 6, wherein said sampling broadband signal analyzer including time domain analyzer means and FFT analyzer means.

9. 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.

10. 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.

11. 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.

12. The system according to claim 11, wherein said amplitude level comparator circuit further generates a counter control output signal whenever said amplitude level signal successively raises above and drops below said amplitude threshold according to one or more amplitude cycles, each said radio frequency signal detector further including a counter circuit receiving said counter control output signal to generate as a sixth one of said strength indicative signals an output signal representing a number of said amplitude cycles.

13. The system according to claim 11, wherein said signal processing means for analyzing the detector output signals derive a ratio of said fourth and fifth output signals for comparing thereof with said one or more predetermined ingress thresholds to generate said alarm signal whenever the ingress signal is detected.

14. The system according to claim 11, wherein said signal processing means for analyzing the detector output signals derive a ratio of said second and fifth output signals for comparing thereof with said one or more predetermined ingress thresholds to generate said alarm signal whenever the ingress signal is detected.

15. 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.

16. The method according to claim 15, wherein said signal analyzing step is performed according to a frequency spectrum scanning mode to generate ingress signal spectral analysis data.

17. The method according to claim 16, wherein said monitoring sequence control data include spectral monitoring sequence control data, said predetermined threshold data including spectral-related threshold data, said comparing step includes the step of comparing said ingress signal spectral analysis with the spectral-related threshold data to generate spectral-related alarm message data included in said alarm message data, the diagnostic sequence control data including spectral diagnostic sequence control data.

18. The method according to claim 16, wherein said signal analyzing step is further performed according to a broadband sampling mode to generate ingress signal broadband analysis data.

19. The method according to claim 18, wherein said monitoring sequence control data include spectral monitoring sequence control data and broadband monitoring sequence control data, said predetermined threshold data including spectral-related threshold data and broadband-related threshold data, said comparing step includes the step of comparing the ingress signal spectral analysis data and the ingress signal broadband analysis data respectively with the spectral-related threshold data and the broadband-related threshold data to generate spectral-related alarm message data and broadband-related alarm message data included in said alarm message data, the diagnostic sequence control data including spectral diagnostic sequence control data and broadband diagnostic sequence control data.

20. The method according to claim 15, wherein said signal analyzing step is performed according to a broadband sampling mode to generate ingress signal broadband analysis data.

21. The method according to claim 20, wherein said monitoring sequence control data include broadband monitoring control sequence data, said predetermined threshold data including broadband-related threshold data, said comparing step including the step of comparing the ingress signal broadband analysis data with the broadband-related threshold data to generate broadband-related alarm message data included in said alarm message data, the diagnostic sequence control data including broadband diagnostic sequence control data.

22. The method according to claim 20, wherein said broadband sampling mode is one of a time domain analyzing mode and a FFT analyzing mode.