Point-to-multipoint performance monitoring and failure isolation system

• US 5,655,068 A
• Filed: 01/17/1996
• Issued: 08/05/1997
• Est. Priority Date: 06/10/1993
• Status: Expired due to Term

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.), 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:
  US08/588,363
• Time in Patent Office: 566 Days
• Field of Search: 395/182.02, 395/184.01, 395/185.05, 395/185.01, 371/4, 371/5.1, 371/6, 371/20.1
• 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 branches each connected between the shared feeder and a different one of the 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, including means for identifying when the error distribution takes the form of a uniform first unacceptably high level of errors across all the remote units, and wherein none of the remote units individually exceeds a second unacceptably high level of errors, the second level of errors being substantially higher than the first level of errors.

2. The system of claim 1, wherein the means for analyzing further includes means for isolating the equipment failure to the shared feeder.

3. The system of claim 2, wherein at least one of the first and second levels is settable by a user.

4. 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 setting a maximum acceptable bit error rate and an alarm triggering bit error rate higher than the maximum acceptable bit error rate; and

means for analyzing the error distribution and identifying therefrom a type of the error distribution indicative of the location of an equipment failure when both the error distribution shows a uniform level of errors across all the remote units that is higher than the maximum acceptable bit error rate, and none of the remote units individually exceeds the alarm triggering bit error rate.

5. The system of claim 4, wherein the means for analyzing further includes means for isolating the equipment failure to the shared feeder section.

6. The system of claim 5, wherein the alarm triggering bit error rate is user settable.

7. 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 having 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 so as to detect both

(i) a uniform distribution of errors across all the remote units at a level higher than the maximum acceptable bit error rate, and

(ii) errors for every individual remote unit less than the alarm triggering bit error rate; and

(f) isolating an equipment failure based on the outcome of comparing step (e).

8. The method of claim 7, wherein isolating step (f) includes the step of isolating the equipment failure to the shared feeder.

9. 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 network having 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 a 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 the 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 upon the decoded downstream error codes and upon a plurality of upstream messages, wherein each of the plurality of second error codes is generated in a different one of the plurality of 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;

(h) setting a first and a second unacceptable error rates, the second rate being substantially higher than the first;

(i) analyzing the error distribution so as to detect the coincidence of both

(1) a uniform distribution of errors across all remote units at a level higher than the first unacceptable error rate, and

(2) an individual error rate for every remote unit at a level lower than the second unacceptable error rate; and

(j) isolating an equipment failure based on the outcome of comparing step (i).

10. The method of claim 9, wherein isolating step (i) includes the step of isolating the equipment failure to the shared feeder.