METHOD AND APPARATUS FOR CHARACTERIZING IMPULSE NOISEAND OPTIMIZING DATA LINK EFFICIENCY

1 . A method of characterizing an impulse noise impairment impacting communications over data links of a network, comprising the steps of:

configuring a test signal comprising a bit stream of a predetermined bit sequence and packet size that is transmitted over the data links;

receiving the test signal transmitted over the data links;

comparing the bit stream of the test signal, as transmitted, to a received bit stream of the test signal, as received during said receiving step, to identify differences in bit sequence; and

estimating characteristics of the impulse noise impairment impacting communications between the data links based on the differences in bit sequence detected during said comparing step.

2 . The method according to claim 1 , wherein the characteristics estimated during said estimating step include at least one of impulse noise duration, impulse noise magnitude and impulse noise periodicity.

3 . The method according to claim 1 , wherein the predetermined bit sequence consists of a known sequence of 1s and 0s that define an array of quadrature amplitude modulation (QAM) symbols.

4 . The method according to claim 3 , wherein the differences in bit sequence identified in said comparing step are analyzed during said estimating step to determine a number of QAM-symbols in the test signal, as received, in error.

5 . The method according to claim 4 , wherein the number of QAM-symbols in error in the test signal, as received, is used to estimate duration of the impulse noise impairment by multiplying the number of QAM-symbols in error by a rate of transmission of each QAM-symbol.

6 . The method according to claim 1 , wherein said steps of receiving, comparing and estimating are repeated for multiple iterations over a period of time to converge on an estimate of the characteristics of the impulse noise impairment.

7 . The method according to claim 1 , further comprising the steps of modifying the test signal configured during said configuring step and, after said modifying step, repeating said steps of receiving, comparing and estimating with use of the test signal as modified during said modifying step.

8 . The method according to claim 1 , further comprising the step of automatically determining and implementing optimal forward error correction (FEC) settings needed to compensate for the impulse noise impairment based on the estimated characteristics of the impulse noise impairment estimated during said estimating step.

9 . The method according to claim 8 , further comprising the step of automatically raising an alarm if the impulse noise impairment impacting communications over the data links, as estimated during said estimating step, cannot be adequately corrected by adjusting available FEC settings.

10 . The method according to claim 1 , further comprising the step of predicting a source of the impulse noise impairment by comparing the characteristics of the impulse noise impairment provided during said estimating step with known signatures of impulse noise impairments produced by suspected sources.

11 . The method according to claim 1 , wherein said receiving step is performed during a maintenance window of the data links of the network.

12 . The method according to claim 1 , wherein said receiving step is performed simultaneously with actively running services over the data links of the network by including the test signal in preamble information of the actively running services.

13 . The method according to claim 1 ,

wherein the test signal transmitted is from a cable modem,

wherein the test signal received during the receiving step is received by a cable modem termination system (CMTS), and

wherein a communication protocol used by the cable modem and CMTS for transmitting and receiving the test signal is Data Over Cable System Interface Specification (DOCSIS).

14 . A signal processing electronic device for characterizing an impulse noise impairment impacting communications over data links of a network, the signal processing electronic device comprising:

at least one processing unit configured

to receive a test signal that comprises a bit stream of a predetermined bit sequence and packet size and that is transmitted over the data links;

to compare the bit stream of the test signal, as transmitted, to a received bit stream of the test signal, as received;

to identify differences in bit sequence; and

to estimate characteristics of the impulse noise impairment impacting communications between the data links, based on the differences in bit sequence detected.

15 . The signal processing electronic device according to claim 14 ,

wherein the signal processing electronic device is selected from a group consisting of a cable modem termination system (CMTS) and a server, and

wherein the characteristics estimated include at least one of impulse noise duration, impulse noise magnitude and impulse noise periodicity.

16 . The signal processing electronic device according to claim 14 , wherein the at least one processing unit is further configured

to analyze the differences in bit sequence to determine a number of QAM-symbols in the test signal, as received, in error and

to estimate duration of the impulse noise impairment by multiplying the number of QAM-symbols in error by a rate of transmission of each QAM-symbol, and

wherein the at least one processing unit is configured to modify the test signal to be transmitted.

17 . The signal processing electronic device according to claim 14 , wherein the at least one processing unit is further configured

to automatically determine and implement optimal forward error correction (FEC) settings needed to compensate for the impulse noise impairment based on the estimated characteristics of the impulse noise impairment, and

wherein the at least one processing unit is configured to automatically raise an alarm if the impulse noise impairment impacting communications over the data links as estimated cannot be adequately corrected by adjusting available FEC settings.

18 . The signal processing electronic device according to claim 14 , wherein the at least one processing unit is further configured

to automatically compare the characteristics of the impulse noise impairment estimated with a plurality of known signatures of impulse noise impairments produced by suspected sources to identify a suspected source of the impulse noise impairment.

19 . At least one non-transitory computer readable storage medium having computer program instructions stored thereon for characterizing an impulse noise impairment impacting communications over data links of a network, wherein the computer program instructions, when executed by at least one processor, cause the at least one processor to perform the following operations:

configure a test signal comprising a bit stream of a predetermined bit sequence and packet size for being transmitted from one end of the data links to an opposite end of the data links and for being received at the opposite end of the data links;

compare the bit stream of the test signal, as transmitted, to a received bit stream of the test signal, as received, to identify differences in bit sequence; and

estimate characteristics of the impulse noise impairment impacting communications between the data links based on the differences in bit sequence.

20 . At least one non-transitory computer readable storage medium according to claim 19 , wherein the computer program instructions, when executed by the at least one processor, cause the at least one processor to perform at least one of the following operations:

determine and implement optimal forward error correction (FEC) settings needed to compensate for the impulse noise impairment based on the estimated characteristics of the impulse noise impairment; and

compare the estimated characteristics of the impulse noise impairment with a plurality of known signatures of impulse noise impairments produced by suspected sources to predict a source of the impulse noise impairment estimated.