Point-to-multipoint performance monitoring and failure isolation system

• US 5,519,830 A
• Filed: 06/10/1993
• Issued: 05/21/1996
• Est. Priority Date: 06/10/1993
• Status: Expired due to Term

• Current Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Original Assignee: ADC Telecommunications Incorporated (TE Connectivity Limited)
• Inventors: Opoczynski, Adam
• Primary Examiner(s): Beausoliel, Jr., Robert W.
• Assistant Examiner(s): Palys, Joseph E.
• Application Number:
  US08/074,913
• Time in Patent Office: 1,076 Days
• Field of Search: 371/20.1, 371/11.2, 371/4, 371/5.1, 371/16.5, 371/6, 395/575, 395/5.2, 395/6, 395/182.02, 395/184.01, 395/185.05, 395/185.01
• US Class Current: 714/4.2
• CPC Class Codes: H04L 1/22 using redundant apparatus to increase reliability
• CPC Class Codes: H04L 1/24 Testing correct operation
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint
• CPC Class Codes: H04L 43/00 Arrangements for monitoring or testing data switching networks

Abstract

A system monitors the performance of a communications network and isolates the location of equipment failures therein through analysis of performance error data. The system passively monitors the performance of the network, operating in the background during normal data and/or voice transmission. The head end generates and inserts multiple error codes, one for each remote unit, into the downstream traffic path. Each remote unit extracts and decodes its respective error code to determine whether a downstream error occurred. Each remote unit then calculates a new error code based on the result of the downstream decode and the respective upstream data message. The head end receives the upstream error codes from all the remote units, decodes them, and accumulates the error data from all remote units over a period of time. An error distribution is generated, and an analysis is performed thereon to isolate the location of error causing equipment failures. The information thus obtained can then be used to initiate facility and equipment protection and/or appropriate maintenance procedures. The invention results in an increased quality of transmission with minimal network down time and minimal impact on overall system performance.

Claims

1. A system for performance monitoring a network and isolating the location of equipment failures therein, the network including a head end and a plurality of remote units connected with a distribution means for transmitting data messages between the head end and the plurality of remote ends, said distribution means including

a shared feeder connected to the head end, and

a plurality of distribution branches, each connected to the shared feeder and to a different one of the plurality of remote units,

said system comprising:

first generating means in the head end for generating a plurality of first error codes based on a plurality of downstream data messages;

first transmitting means in the head end for transmitting the plurality of first error codes and the plurality of downstream data messages to the plurality of remote units

a plurality of first decoding means, each in a different one of the plurality of remote units, each for decoding one of the plurality of first error codes and determining therefrom whether a downstream error occurred;

a plurality of second generating means, each in a different one of the plurality of remote units, each for generating one of a plurality of second error codes as a function of an upstream data message and whether a downstream error in transmission to the different one of the plurality of remote units occurred;

a plurality of transmitters, each in a different one of the plurality of remote units, for transmitting the one of the plurality of second error codes and the upstream data message to the head end;

decoding means in the head end for decoding the plurality of second error codes received from the plurality of remote units and producing therefrom a plurality of error data;

processing means in the head end for producing an error distribution from the plurality of error data; and

means for analyzing the error distribution to isolate the location of equipment failures, said means for analyzing including means for identifying when the error distribution takes the form of an unacceptably high level of errors for two of the plurality of remote units and an acceptable level of errors for the remaining plurality of remote units,

wherein the means for analyzing further includes means for isolating the equipment failure to the two remote units having the unacceptably high level of errors.

2. The system of claim 1 wherein the means for analyzing further includes means for identifying when the magnitudes of the unacceptably high level of errors for the two of the plurality of remote units are equivalent.

3. A system for performance monitoring a network and isolating the location of equipment failures therein, the network including a head end and a plurality of remote units connected with a distribution means for transmitting data messages between the head end and the plurality of remote ends, said distribution means including

a shared feeder connected to the head end, and

a plurality of distribution branches, each connected to the shared feeder and to a different one of the plurality of remote units,

said system comprising:

first generating means in the head end for generating a plurality of first error codes based on a plurality of downstream data messages;

first transmitting means in the head end for transmitting the plurality of first error codes and the plurality of downstream data messages to the plurality of remote units

a plurality of first decoding means, each in a different one of the plurality of remote units, each for decoding one of the plurality of first error codes and determining therefrom whether a downstream error occurred;

a plurality of second generating means, each in a different one of the plurality of remote units, each for generating one of a plurality of second error codes as a function of an upstream data message and whether a downstream error in transmission to the different one of the plurality of remote units occurred;

a plurality of transmitters, each in a different one of the plurality of remote units, for transmitting the one of the plurality of second error codes and the upstream data message to the head end;

decoding means in the head end for decoding the plurality of second error codes received from the plurality of remote units and producing therefrom a plurality of error data;

processing means in the head end for producing an error distribution from the plurality of error data; and

means for analyzing the error distribution to isolate the location of equipment failures,

wherein the means for analyzing includes means for identifying when the error distribution takes the form of a first unacceptably high level of errors for one of the plurality of remote units and a second unacceptably high level of errors for the remaining plurality of remote units, the second unacceptably high level of errors being less than the first unacceptably high level of errors.

4. The system of claim 3 wherein the means for analyzing further includes means for isolating the equipment failure to the remote unit having the first unacceptably high level of errors.

5. The system of claim 4 wherein the means for analyzing further includes means for identifying when the first unacceptably high level of errors is of the same magnitude as a total number of errors occurring in across all the remaining plurality of remote units.

6. A system for isolating the location of equipment failures in a telecommunications system including a head end, a plurality of remote ends and a distribution means for transmitting messages between the head end and the plurality of remote units, the distribution means including a shared feeder section connected to the head end and a plurality of distribution sections each connected to the shared feeder and to a different one of the plurality of remote units, the system comprising:

means in the head end for generating a plurality of downstream error codes, each based on a different one of a plurality of downstream messages;

means in each of the remote units for receiving a different one of the plurality of downstream messages and the respective one of the plurality of downstream error codes;

means in each of the remote units for decoding the received downstream error code and determining therefrom whether a downstream error occurred;

error flag means in each of the remote units for indicating whether a downstream error occurred;

means in each of the remote units for generating one of a plurality of upstream error codes each based on one of a plurality of upstream messages and on the decoded downstream error code;

means in the head end for receiving the plurality of upstream messages and the plurality of upstream error codes;

means in the head end for decoding the plurality of upstream error codes, determining therefrom whether at least one of either a downstream or upstream error occurred, and producing therefrom error data representative of at least one of either a downstream or upstream error in transmissions to and from each of the plurality of remote units;

accumulating means for accumulating the error data over a selected period of time and producing therefrom accumulated error data;

means for producing an error distribution across the plurality of remote ends from the accumulated error data;

means for analyzing the error distribution and identifying therefrom a type of the error distribution indicative of the location of an equipment failure;

means for setting a maximum acceptable bit error rate, including means for identifying when the error distribution shows a first level of errors associated with one of the plurality of remote units that is higher than the alarm triggering bit error rate and a uniform level of errors across the remaining plurality of remote units at a second level that is lower than the maximum acceptable bit error rate; and

means for setting an alarm triggering bit error rate.

7. The system according to claim 6 wherein the means for analyzing further includes means for identifying when the equipment failure to the one of the plurality of remote units having the first level of errors or to the distribution section connected thereto.

8. A system for isolating the location of equipment failures in a telecommunications system including a head end, a plurality of remote ends and a distribution means for transmitting messages between the head end and the plurality of remote units, the distribution means including a shared feeder section connected to the head end and a plurality of distribution sections each connected to the shared feeder and to a different one of the plurality of remote units, the system comprising:

means in the head end for generating a plurality of downstream error codes, each based on a different one of a plurality of downstream messages;

means in each of the remote units for receiving a different one of the plurality of downstream messages and the respective one of the plurality of downstream error codes;

means in each of the remote units for decoding the received downstream error code and determining therefrom whether a downstream error occurred;

error flag means in each of the remote units for indicating whether a downstream error occurred;

means in each of the remote units for generating one of a plurality of upstream error codes each based on one of a plurality of upstream messages and on the decoded downstream error code;

means in the head end for receiving the plurality of upstream messages and the plurality of upstream error codes;

means in the head end for decoding the plurality of upstream error codes, determining therefrom whether at least one of either a downstream or upstream error occurred, and producing therefrom error data representative of at least one of either a downstream or upstream error in transmissions to and from each of the plurality of remote units;

accumulating means for accumulating the error data over a selected period of time and producing therefrom accumulated error data;

means for producing an error distribution across the plurality of remote ends from the accumulated error data;

means for analyzing the error distribution and identifying therefrom a type of the error distribution indicative of the location of an equipment failure;

including means for identifying when the error distribution shows a first level of errors associated with two of the plurality of remote units that is higher than the alarm triggering bit error rate and a uniform level of errors across the remaining plurality of remote units at a second level that is lower than the maximum acceptable bit error rate; and

means for setting a maximum acceptable bit error rate.

9. The system according to claim 8 wherein the means for analyzing further includes means for identifying when the equipment failure to the two of the plurality of remote units having the first level of errors or to the distribution sections connected thereto.

10. A system for isolating the location of equipment failures in a telecommunications system including a head end, a plurality of remote ends and a distribution means for transmitting messages between the head end and the plurality of remote units, the distribution means including a shared feeder section connected to the head end and a plurality of distribution sections each connected to the shared feeder and to a different one of the plurality of remote units, the system comprising:

means in the head end for generating a plurality of downstream error codes, each based on a different one of a plurality of downstream messages;

means in each of the remote units for receiving a different one of the plurality of downstream messages and the respective one of the plurality of downstream error codes;

means in each of the remote units for decoding the received downstream error code and determining therefrom whether a downstream error occurred;

error flag means in each of the remote units for indicating whether a downstream error occurred;

means in each of the remote units for generating one of a plurality of upstream error codes each based on one of a plurality of upstream messages and on the decoded downstream error code;

means in the head end for receiving the plurality of upstream messages and the plurality of upstream error codes;

means in the head end for decoding the plurality of upstream error codes, determining therefrom whether at least one of either a downstream or upstream error occurred, and producing therefrom error data representative of at least one of either a downstream or upstream error in transmissions to and from each of the plurality of remote units;

accumulating means for accumulating the error data over a selected period of time and producing therefrom accumulated error data;

means for producing an error distribution across the plurality of remote ends from the accumulated error data;

means for analyzing the error distribution and identifying therefrom a type of the error distribution indicative of the location of an equipment failure, including means for identifying when the error distribution rate shows a first level of errors associated with one of the plurality of remote units that is higher than the maximum acceptable bit error rate and a uniform level of errors across the remaining plurality of remote units at a second level that is higher than the maximum acceptable bit error rate and lower than the first level of errors; and

means for setting a maximum acceptable bit error rate.

11. The system according to claim 10 wherein the means for analyzing further includes means for isolating the equipment failure to the one of the plurality of remote units having the first level of errors or to the distribution section connected thereto.

12. A method of analyzing an error distribution to isolate the location of equipment failures in a communications system, the communications system including a distribution network including a shared feeder connected to a head end and a plurality of distribution sections, each connected to the shared feeder and to a different one of a plurality of remote units, the method comprising the step of:

(a) setting a maximum acceptable bit error rate;

(b) setting an alarm triggering bit error rate, wherein the alarm triggering bit error rate is higher than the maximum acceptable bit error rate;

(c) accumulating a plurality of error codes representative of at least one of either a downstream or upstream error in transmissions to and from each of the plurality of remote units and generating therefrom a set of error data;

(d) generating an error distribution from the set of error data received from the plurality of remote units;

(e) comparing the error distribution with the maximum acceptable bit error rate and the alarm triggering bit error rate; and

(f) isolating an equipment failure based on the outcome of comparing step (e), including isolating a second equipment failure if the result of comparison step (e) shows a level of errors that is higher than the alarm triggering bit error rate for one of the plurality of remote units and an even distribution of errors across the remaining plurality of remote units at a level that is lower than the maximum acceptable bit error rate.

13. The method according to claim 12 wherein isolating step (f) further includes the step of isolating the equipment failure to the one of the plurality of remote units.

14. The method according to claim 12 wherein isolating step (f) further includes the step of isolating the equipment failure to two of the plurality of remote units.

15. A method of analyzing an error distribution to isolate the location of equipment failures in a communications system, the communications system including a distribution network including a shared feeder connected to a head end and a plurality of distribution sections, each connected to the shared feeder and to a different one of a plurality of remote units, the method comprising the step of:

(a) setting a maximum acceptable bit error rate;

(b) setting an alarm triggering bit error rate, wherein the alarm triggering bit error rate is higher than the maximum acceptable bit error rate;

(c) accumulating a plurality of error codes representative of at least one of either a downstream or upstream error in transmissions to and from each of the plurality of remote units and generating therefrom a set of error data;

(d) generating an error distribution from the set of error data received from the plurality of remote units;

(e) comparing the error distribution with the maximum acceptable bit error rate and the alarm triggering bit error rate; and

(f) isolating an equipment failure based on the outcome of comparing step (e) wherein the plurality of remote units includes at least three remote units and including the step of isolating a third equipment failure if the result of comparison step (e) shows a level of errors that is higher than the alarm triggering bit error rate for two of the plurality of remote units and an ever distribution of errors across the remaining plurality of remote units at a level that is lower than the maximum acceptable bit error rate.

16. A method of analyzing an error distribution to isolate the location of equipment failures in a communications system, the communications system including a distribution network including a shared feeder connected to a head end and a plurality of distribution sections, each connected to the shared feeder and to a different one of a plurality of remote units, the method comprising the step of:

(a) setting a maximum acceptable bit error rate;

(b) setting an alarm triggering bit error rate, wherein the alarm triggering bit error rate is higher than the maximum acceptable bit error rate;

(c) accumulating a plurality of error codes representative of at least one of either a downstream or upstream error in transmissions to and from each of the plurality of remote units and generating therefrom a set of error data;

(d) generating an error distribution from the set of error data received from the plurality of remote units;

(e) comparing the error distribution with the maximum acceptable bit error rate and the alarm triggering bit error rate; and

(f) isolating an equipment failure based on the outcome of comparing step (e), including isolating a fourth equipment failure if the result of comparison step (e) shows a first rate of errors for one of the plurality of remote units that is higher than the maximum acceptable bit error rate and an even distribution of errors across the remaining plurality of remote units at a second rate of errors that is higher than the maximum acceptable bit error rate, wherein the second rate of errors is lower than the first rate of errors.

17. The method according to claim 16 wherein isolating step (f) further includes the step of isolating the equipment failure to the one of the plurality of remote units.

18. A method for monitoring the performance of a telecommunications system connected in a point-to-multipoint configuration, and for isolating the location of equipment failures therein, the telecommunications system including a distribution system including a shared feeder section connected to a head end and a plurality of distribution sections each connected to the shared feeder section and to a different one of the plurality of remote units, the method comprising the steps of:

(a) generating a plurality of first error codes based on a plurality at the head end of downstream messages;

(b) transmitting each of the plurality of error codes to a different one of a plurality of remote units over the distribution network;

(c) decoding at each remote unit each of the error codes and downstream messages to determine whether any downstream errors occurred;

(d) generating at each remote unit a plurality of second error codes based on the decoded downstream error codes and on a plurality of upstream messages, wherein each of the plurality of second error codes is generated in a different one of the remote units;

(e) transmitting the plurality of second error codes and corresponding upstream messages to the head end over the distribution network;

(f) accumulating the plurality of error codes received from the plurality of remote units over a selected period of time;

(g) generating an error distribution from the accumulated error codes; and

(h) analyzing the error distribution and isolating therefrom the location of the equipment failures;

(i) setting a maximum acceptable bit error rate;

(j) setting an alarm triggering bit error rate, wherein the alarm triggering bit error rate is higher than the maximum acceptable bit error rate;

(k) comparing the error distribution with the maximum acceptable bit error rate and the alarm triggering bit error rate;

(l) isolating an equipment failure based on the outcome of comparing step (k), including isolating a second equipment failure if the result of the comparison step (k) shows a rate of errors that is higher than the alarm triggering bit error rate for one of the plurality of remote units and an even distribution of errors across the remaining plurality of remote units at a rate that is lower than the maximum acceptable bit error rate.

19. The method according to claim 18 wherein isolating step (l) further includes the step of isolating the equipment failure to the one of the plurality of remote units.

20. A method for monitoring the performance of a telecommunications system connected in a point-to-multipoint configuration, and for isolating the location of equipment failures therein, the telecommunications system including a distribution system including a shared feeder section connected to a head end and a plurality of distribution sections each connected to the shared feeder section and to a different one of the plurality of remote units, the method comprising the steps of:

(a) generating a plurality of first error codes based on a plurality at the head end of downstream messages;

(b) transmitting each of the plurality of error codes to a different one of a plurality of remote units over the distribution network;

(c) decoding at each remote unit each of the error codes and downstream messages to determine whether any downstream errors occurred;

(d) generating at each remote unit a plurality of second error codes based on the decoded downstream error codes and on a plurality of upstream messages, wherein each of the plurality of second error codes is generated in a different one of the remote units;

(e) transmitting the plurality of second error codes and corresponding upstream messages to the head end over the distribution network;

(f) accumulating the plurality of error codes received from the plurality of remote units over a selected period of time;

(g) generating an error distribution from the accumulated error codes; and

(h) analyzing the error distribution and isolating therefrom the location of the equipment failures;

(i) setting a maximum acceptable bit error rate;

(j) setting an alarm triggering bit error rate, wherein the alarm triggering bit error rate is higher than the maximum acceptable bit error rate;

(k) comparing the error distribution with the maximum acceptable bit error rate and the alarm triggering bit error rate;

(l) isolating an equipment failure based on the outcome of comparing step (k), including isolating a third equipment failure if the result of comparison step (k) shows a rate of errors that is higher than the alarm triggering bit error rate for two of the plurality of remote units and an even distribution of errors across the remaining plurality of remote units at a rate that is lower than the maximum acceptable bit error rate.

21. The method according to claim 20 wherein isolating step (l) further includes the step of isolating the equipment failure to the two of the plurality of remote units.

22. A method for monitoring the performance of a telecommunications system connected in a point-to-multipoint configuration, and for isolating the location of equipment failures therein, the telecommunications system including a distribution system including a shared feeder section connected to a head end and a plurality of distribution sections each connected to the shared feeder section and to a different one of the plurality of remote units, the method comprising the steps of:

(a) generating a plurality of first error codes based on a plurality at the head end of downstream messages;

(b) transmitting each of the plurality of error codes to a different one of a plurality of remote units over the distribution network;

(c) decoding at each remote unit each of the error codes and downstream messages to determine whether any downstream errors occurred;

(d) generating at each remote unit a plurality of second error codes based on the decoded downstream error codes and on a plurality of upstream messages, wherein each of the plurality of second error codes is generated in a different one of the remote units;

(e) transmitting the plurality of second error codes and corresponding upstream messages to the head end over the distribution network;

(f) accumulating the plurality of error codes received from the plurality of remote units over a selected period of time;

(g) generating an error distribution from the accumulated error codes; and

(h) analyzing the error distribution and isolating therefrom the location of the equipment failures;

(i) setting a maximum acceptable bit error rate;

(j) setting an alarm triggering bit error rate, wherein the alarm triggering bit error rate is higher than the maximum acceptable bit error rate;

(k) comparing the error distribution with the maximum acceptable bit error rate and the alarm triggering bit error rate;

(l) isolating an equipment failure based on the outcome of comparing step (k), including isolating a fourth equipment failure if the result of the comparison step (k) shows a first rate of errors that is higher than the maximum acceptable bit error rate for one of the plurality of remote units and an even distribution of errors across the remaining plurality of remote units at a second rate of errors that is higher than the maximum acceptable bit error rate, wherein the second rate of errors is lower than the first rate of errors.

23. The method according to claim 22 wherein isolating step (l) further includes the step of isolating the equipment failure to the one of the plurality of remote units.