Monitoring system for a hybrid fiber cable network

• US 6,400,863 B1
• Filed: 06/06/2000
• Issued: 06/04/2002
• Est. Priority Date: 06/11/1999
• Status: Expired due to Term

• Current Assignee: ARRIS Enterprises LLC (CommScope Holding Company, Inc.)
• Original Assignee: General Instrument Corporation (CommScope Holding Company, Inc.)
• Inventors: Holborow, Clive E., Blum, William H., Weinstock, Jonathan A., Dziekan, Richard R., Lee, Nicholas D.
• Primary Examiner(s): Healy, Brian
• Application Number:
  US09/588,387
• Time in Patent Office: 728 Days
• Field of Search: 385/15, 385/16, 385/17, 385/24, 385/39, 385/42, 385/14, 385/100, 385/101, 359/109, 359/113, 359/115, 359/118, 359/125, 359/143, 359/173
• US Class Current: 385/24
• CPC Class Codes: H04B 10/077 using a supervisory or additional signal
• CPC Class Codes: H04B 10/07955 Monitoring or measuring power

Abstract

A monitoring system for a HFC network includes a plurality of “test points” disposed at various locations throughout the network. Each test point is used to allow for the isolation of communication problems within the network (for example, ingress) and mitigation of the effects of the network problems. By distributing a plurality of test points throughout the topology of the network, only limited sections of the network need to be isolated at any point in time to address the particular communication problem.

Claims

1. A broadband hybrid fiber cable communication network for providing bi-directional communication between a headend and a plurality of endpoints, the network comprising

a plurality of cable branches coupled to the cable modem test system for distributing downstream communication along a plurality of cable communication paths to a group of endpoints located at drops along each cable communication path, each cable branch also for consolidating upstream communication from its associated group of endpoints;

a network monitoring system for monitoring communication signals propagating both downstream from the headend to the endpoints and upstream from the endpoints to the headend, the monitoring system utilizing a predetermined bit error rate threshold associated with both upstream and downstream communication and functioning to measure the real time bit error rates associated with both upstream and downstream communication within the network, said monitoring system further providing a control output signal when the predetermined error rate threshold is exceeded; and

a plurality of test points disposed within the network between the headend and each cable branch, each test point in communication with the monitoring system for receiving as an input said monitoring system control output signal and using said control output signal to isolate a particular location associated with excessive bit error rate.

2. A broadband hybrid fiber cable communication network as defined in claim 1 wherein the network monitoring system comprises

a cable modem test system coupled to an upstream termination of each cable branch, said cable modem test system including predetermined bit error rate threshold limits and responsive to information transmission upstream along each branch for comparing a real time bit error rate with the predetermined bit error rate threshold and generating an alarm signal when a bit error rate threshold has been exceeded at an identified location within the network; and

a network monitoring system, responsive to the alarm output from the cable modem test set, for determining the identity of the test point associated with the received alarm and transmitting an alarm response signal to said identified test point.

3. A broadband hybrid fiber cable communication network as defined in claim 1 wherein a separate test point is disposed at the upstream termination of each cable branch.

4. A broadband hybrid fiber cable communication network as defined in claim 1 wherein a plurality of test points are disposed along each cable branch, a separate test point associated with separate groups of endpoints.

5. A broadband hybrid fiber cable communication network as defined in claim 1 wherein each test point comprises an active notch filter.

6. A broadband hybrid fiber cable communication network as defined in claim 1 wherein each test point comprises a broadband/telephone interface (BTI unit including a downstream receiver and an upstream transmitter for monitoring the communication on the downstream path and upstream path, respectively.

7. A broadband hybrid fiber cable communication network as defined in claim 1 wherein each test point comprises a scanning receiver for monitoring a plurality of separate channels capable of being used for upstream transmission.

8. A broadband hybrid fiber cable communication network as defined in claim 1 wherein each test point comprises a plurality of separate receivers, each for monitoring a separate one of a plurality of channels capable of being used for upstream transmission.

9. A monitoring arrangement for use in a hybrid fiber coax communication network comprising a plurality of separate cable branches, each cable branch comprising

a plurality of endpoints and the plurality of branches terminating at a common headend, the arrangement comprising

a monitoring system for monitoring communication signals propagating both downstream from the headend to the endpoints and upstream from the endpoints to the headend, utilizing a predetermined bit error rate threshold associated with both upstream and downstream communication and functioning to measure the real time bit error rates associated with both upstream and downstream communication within the network, said monitoring system further providing a control output signal when the predetermined error rate threshold is exceeded;

and

a plurality of test points disposed within the network between the headend and each cable branch, each test point in communication with the monitoring system for receiving as an input said monitoring system control output signal and using said control output signal to isolate a particular location associated with excessive bit error rate.

10. A monitoring arrangement as defined in claim 9 wherein the network monitoring system comprises

a cable modem test system coupled to an upstream termination of each cable branch, said cable modem test system including predetermined bit error rate threshold limits and responsive to information transmission upstream along each branch for comparing a real time bit error rate with the predetermined bit error rate threshold and generating an alarm signal when a bit error rate threshold has been exceeded at an identified location within the network; and

a network monitoring system, responsive to the alarm output from the cable modem test set, for determining the identity of the test point associated with the received alarm and transmitting an alarm response signal to said identified test point.

11. A monitoring arrangement as defined in claim 9 wherein a separate test point is disposed at the upstream termination of each cable branch.

12. A monitoring arrangement as defined in claim 9 wherein a plurality of test points are disposed along each cable branch, a separate test point associated with separate groups of endpoints.

13. A monitoring arrangement as defined in claim 9 wherein each test point comprises an active notch filter.

14. A monitoring arrangement as defined in claim 9 wherein each test point comprises a broadband/telephone interface (BTI) unit including a downstream receiver and an upstream transmitter for monitoring the communication on the downstream path and upstream path, respectively.

15. A monitoring arrangement as defined in claim 9 wherein each test point comprises a scanning receiver for monitoring a plurality of separate channels capable of being used for upstream transmission.

16. A monitoring arrangement as defined in claim 9 wherein each test point comprises a plurality of separate receivers, each for monitoring a separate one of a plurality of channels capable of being used for upstream transmission.