Method and system for determining origin of optical signal quality degradation
First Claim
1. A method for determining the origin of optical signal quality degradation comprising:
- an optical signal amplitude histogram measurement step of obtaining an optical signal amplitude histogram from an optical signal under measurement;
an averaged Q-factor parameter measurement step of obtaining an averaged Q-factor parameter, which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step;
a waveform distortion parameter measurement step of obtaining a waveform distortion parameter, which is another optical signal quality parameter calculated from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step; and
an optical signal quality evaluation step of evaluating an optical signal quality degradation factor using a measurement value of the averaged Q-factor parameter and a measurement value of the waveform distortion parameter obtained in said averaged Q-factor parameter measurement step and said waveform distortion parameter measurement step,wherein said optical signal quality evaluation step makes a decision that a main factor of the optical signal quality degradation is the waveform distortion in the optical signal under measurement when the averaged Q-factor parameter is reduced and the waveform distortion parameter is increased, and makes a decision that the main factor of the optical signal quality degradation is a factor other than waveform distortion when the waveform distortion parameter is not increased.
1 Assignment
0 Petitions
Accused Products
Abstract
A monitoring system includes first and second evaluation sections for obtaining an averaged Q-factor parameter and a waveform distortion parameter from an optical signal amplitude histogram collected from optical signals under measurement. The monitoring system further includes a third evaluation section for determining both averaged Q-factor parameter and waveform distortion parameter, and for making a decision as to whether the main factor of the optical signal quality degradation is waveform distortion or not by comparing the averaged Q-factor parameter and waveform distortion parameter with their initial values or initial characteristics which are obtained when no optical signal quality degradation is present.
-
Citations
30 Claims
-
1. A method for determining the origin of optical signal quality degradation comprising:
-
an optical signal amplitude histogram measurement step of obtaining an optical signal amplitude histogram from an optical signal under measurement; an averaged Q-factor parameter measurement step of obtaining an averaged Q-factor parameter, which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step; a waveform distortion parameter measurement step of obtaining a waveform distortion parameter, which is another optical signal quality parameter calculated from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step; and an optical signal quality evaluation step of evaluating an optical signal quality degradation factor using a measurement value of the averaged Q-factor parameter and a measurement value of the waveform distortion parameter obtained in said averaged Q-factor parameter measurement step and said waveform distortion parameter measurement step, wherein said optical signal quality evaluation step makes a decision that a main factor of the optical signal quality degradation is the waveform distortion in the optical signal under measurement when the averaged Q-factor parameter is reduced and the waveform distortion parameter is increased, and makes a decision that the main factor of the optical signal quality degradation is a factor other than waveform distortion when the waveform distortion parameter is not increased. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15)
-
-
2. A method for determining the origin of optical signal quality degradation comprising:
-
an optical signal amplitude histogram measurement step of obtaining an optical signal amplitude histogram from an optical signal under measurement; an averaged Q-factor parameter measurement step of obtaining an averaged Q-factor parameter, which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step; a waveform distortion parameter measurement step of obtaining a waveform distortion parameter, which is another optical signal quality parameter calculated from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step; an initial state storing step of storing into a storage medium at least one of an initial value and initial characteristic of the averaged Q-factor parameter and the waveform distortion parameter at a system installation without optical signal quality degradation, which are obtained using said averaged Q-factor parameter measurement step and said waveform distortion parameter measurement step; and an optical signal quality evaluation step of evaluating an optical signal quality degradation factor using a measurement value of the averaged Q-factor parameter and a measurement value of the waveform distortion parameter obtained in said averaged Q-factor parameter measurement step and said waveform distortion parameter measurement step, and using at least one of the initial values and initial characteristics stored in the storage medium in said initial state storing step, wherein said optical signal quality evaluation step makes a decision that a main factor of the optical signal quality degradation is the waveform distortion in the optical signal under measurement when the averaged Q-factor parameter is reduced and the waveform distortion parameter is increased, and makes a decision that the main factor of the optical signal quality degradation is a factor other than waveform distortion when the waveform distortion parameter is not increased.
-
-
3. A method for determining the origin of optical signal quality degradation comprising:
-
an optical splitting step of splitting an optical signal under measurement; an optical signal amplitude histogram measurement step of obtaining an optical signal amplitude histogram from a first optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting step; an averaged Q-factor parameter measurement step of obtaining an averaged Q-factor parameter, which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step; an optical signal to optical noise power measurement step of measuring optical signal to optical noise power from a second optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting step; an optical signal-to-noise ratio parameter obtaining step of obtaining an optical signal-to-noise ratio parameter, which is another optical signal quality parameter from the optical signal to optical noise power obtained in said optical signal to optical noise power measurement step; and an optical signal quality evaluation step of evaluating an optical signal quality degradation factor using a measurement value of the averaged Q-factor parameter obtained in said averaged Q-factor parameter measurement step and a measurement value of the optical signal-to-noise ratio parameter obtained in said optical signal-to-noise ratio parameter obtaining step, wherein said optical signal quality evaluation step makes a decision as to whether a main factor of the optical signal quality degradation is the degradation in the optical signal-to-noise ratio or not by determining and evaluating both the averaged Q-factor parameter and the optical signal-to-noise ratio parameter.
-
-
4. A method for obtaining the origin of optical signal quality degradation comprising:
-
an optical splitting step of splitting an optical signal under measurement; an optical signal amplitude histogram measurement step of obtaining an optical signal amplitude histogram from a first optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting step; an averaged Q-factor parameter measurement step of obtaining an averaged Q-factor parameters which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step; an optical signal to optical noise power measurement step of measuring optical signal to optical noise power from a second optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting step; an optical signal-to-noise ratio parameter obtaining step of obtaining an optical signal-to-noise ratio parameter, which is another optical signal quality parameter from the optical signal to optical noise power obtained in said optical signal to optical noise power measurement step; an initial state storing step of storing into a storage medium at least one of an initial value and initial characteristic of the averaged Q-factor parameter and of the optical signal-to-noise ratio parameter at a system installation without optical signal quality degradation, which are obtained using said averaged Q-factor parameter measurement step and said optical signal-to-noise ratio parameter obtaining step; and an optical signal quality evaluation step of evaluating an optical signal quality degradation factor using a measurement value of the averaged Q-factor parameter obtained in said averaged Q-factor parameter measurement step and a measurement value of the optical signal-to-noise ratio parameter obtained in said optical signal-to-noise ratio parameter obtaining step, and using at least one of the initial values and initial characteristics of the averaged Q-factor parameter and the optical signal-to-noise ratio parameter at the system installation without optical signal quality degradation, which are stored in the storage medium in said initial state storing step, wherein said optical signal quality evaluation step makes a decision as to whether a main factor of the optical signal quality degradation is the degradation in the optical signal-to-noise ratio or not by determining and evaluating both the averaged Q-factor parameter and the optical signal-to-noise ratio parameter.
-
-
5. A method for determining the origin of optical signal quality degradation comprising:
-
an optical splitting step of splitting an optical signal under measurement; an optical signal amplitude histogram measurement step of obtaining an optical signal amplitude histogram from a first optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting step; an optical signal to optical noise power measurement step of measuring optical signal to optical noise power from a second optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting step; a waveform distortion parameter measurement step of obtaining a waveform distortion parameter, which is an optical signal quality parameter from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step; an optical signal-to-noise ratio parameter obtaining step of obtaining an optical signal-to-noise ratio parameter which is an optical signal quality parameter from the optical signal to optical noise power obtained in said optical signal to optical noise power measurement step; and an optical signal quality evaluation step of evaluating an optical signal quality degradation factor using a measurement value of the waveform distortion parameter obtained in said waveform distortion parameter measurement step, and a measurement value of the optical signal-to-noise ratio parameter obtained in said optical signal-to-noise ratio parameter obtaining step, wherein said optical signal quality evaluation step makes a decision as to whether a main factor of the optical signal quality degradation is the degradation in the optical signal-to-noise ratio or the waveform distortion by determining and evaluating both the waveform distortion parameter and the optical signal-to-noise ratio parameter.
-
-
6. A method for determining the origin of optical signal quality degradation comprising:
-
an optical splitting step of splitting an optical signal under measurement; an optical signal amplitude histogram measurement step of obtaining an optical signal amplitude histogram from a first optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting step; an optical signal to optical noise power measurement step of measuring optical signal to optical noise power from a second optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting step; a waveform distortion parameter measurement step of obtaining a waveform distortion paramete, which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step; an optical signal-to-noise ratio parameter obtaining step of obtaining an optical signal-to-noise ratio parameter, which is another optical signal quality parameter from the optical signal to optical noise power obtained in said optical signal to optical noise power measurement step; an initial state storing step of storing into a storage medium at least one of an initial value and initial characteristic of the waveform distortion parameter and that of the optical signal-to-noise ratio parameter at a system installation without optical signal quality degradation, which are obtained using said waveform distortion parameter measurement step and said optical signal-to-noise ratio parameter obtaining step; and an optical signal quality evaluation step of evaluating an optical signal quality degradation factor using a measurement value of the waveform distortion parameter obtained in said waveform distortion parameter measurement step and a measurement value of the optical signal-to-noise ratio parameter obtained in said optical signal-to-noise ratio parameter obtaining step, and using at least one of the initial values and initial characteristics of the waveform distortion parameter and that of the optical signal-to-noise ratio parameter at the system installation without optical signal quality degradation, wherein said optical signal quality evaluation step makes a decision as to whether a main factor of the optical signal quality degradation is the degradation in the optical signal-to-noise ratio or the waveform distortion by determining and evaluating both the waveform distortion parameter and the optical signal-to-noise ratio parameter.
-
-
7. A method for determining the origin of optical signal quality degradation comprising:
-
an optical splitting step of splitting an optical signal under measurement; an optical signal amplitude histogram measurement step of obtaining an optical signal amplitude histogram from a first optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting step; an averaged Q-factor parameter measurement step of obtaining an averaged Q-factor parameter, which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step; an optical signal to optical noise power measurement step of measuring optical signal to optical noise power from a second optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting step; a waveform distortion parameter measurement step of obtaining a waveform distortion parameter, which is another optical signal quality parameter calculated from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step; an optical signal-to-noise ratio parameter obtaining step of obtaining an optical signal-to-noise ratio parameter, which is another optical signal quality parameter from the optical signal to optical noise power obtained in said optical signal to optical noise power measurement step; and an optical signal quality evaluation step of evaluating an optical signal quality degradation factor using a measurement value of the averaged Q-factor parameter obtained in said averaged Q-factor parameter measurement step, a measurement value of the waveform distortion parameter obtained in said waveform distortion parameter measurement step, and a measurement value of the optical signal-to-noise ratio parameter obtained in said optical signal-to-noise ratio parameter obtaining step, wherein said optical signal quality evaluation step makes a decision as to whether a main factor of the optical signal quality degradation is the degradation in the optical signal-to-noise ratio or the waveform distortion or not by determining and evaluating all of the averaged Q-factor parameter, the waveform distortion parameter1 and the optical signal-to-noise ratio parameter.
-
-
8. A method for determining the origin of optical signal quality degradation comprising:
-
an optical splitting step of splitting an optical signal under measurement; an optical signal amplitude histogram measurement step of obtaining an optical signal amplitude histogram from a first optical signal under measurement, which is obtained by splitting the optical signal under measurement in said optical splitting step; an averaged Q-factor parameter measurement step of obtaining an averaged Q-factor parameter1, which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step; an optical signal to optical noise power measurement step of measuring optical signal to optical noise power from a second optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting step; a waveform distortion parameter measurement step of obtaining a waveform distortion parameter, which is another optical signal quality parameter calculated from the optical signal amplitude histogram obtained in said optical signal amplitude histogram measurement step; an optical signal-to-noise ratio parameter obtaining step of obtaining an optical signal-to-noise ratio parameter, which is another optical signal quality parameter from the optical signal to optical noise power obtained in said optical signal to optical noise power measurement step; an initial state storing step of storing into a storage medium at least one of an initial value and an initial characteristic of the averaged Q-factor parameter, that of the waveform distortion parameter, and that of the optical signal-to-noise ratio parameter at a system installation without optical signal quality degradation, which are obtained using said averaged Q-factor parameter measurement step, said waveform distortion parameter measurement step and said optical signal-to-noise ratio parameter obtaining step; and an optical signal quality evaluation step of evaluating an optical signal quality degradation factor using a measurement value of the averaged Q-factor parameter obtained in said averaged Q-factor parameter measurement step, a measurement value of the waveform distortion parameter obtained in said waveform distortion parameter measurement step, and a measurement value of the optical signal-to-noise ratio parameter obtained in said optical signal-to-noise ratio parameter obtaining step, and using at least one of the initial values and initial characteristics of the averaged Q-factor parameter, that of the waveform distortion parameter, and the optical signal-to-noise ratio parameter at the system installation without optical signal quality degradation, which are stored into the storage medium by said initial state storing step, wherein said optical signal quality evaluation step makes a decision as to whether a main factor of the optical signal quality degradation is degradation in the optical signal-to-noise ratio, the waveform distortion or not by determining and evaluating all the averaged Q-factor parameter, the waveform distortion parameter, and the optical signal-to-noise ratio parameter.
-
-
16. A system for determining the origin of optical signal quality degradation comprising:
-
optical signal amplitude histogram measurement means for obtaining an optical signal amplitude histogram from an optical signal under measurement; averaged Q-factor parameter measurement means for obtaining an averaged Q-factor parameter, which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained by said optical signal amplitude histogram measurement means; waveform distortion parameter measurement means for obtaining a waveform distortion parameter, which is another optical signal quality parameter calculated from the optical signal amplitude histogram obtained by said optical signal amplitude histogram measurement means; and optical signal quality evaluation means for evaluating an optical signal quality degradation factor using a measurement value of the averaged Q-factor parameter and a measurement value of the waveform distortion parameter obtained by said averaged Q-factor parameter measurement means and said waveform distortion parameter measurement means, wherein said optical signal quality evaluation means makes a decision that a main factor of the optical signal quality degradation is the waveform distortion in the optical signal under measurement when the averaged Q-factor parameter is reduced and the waveform distortion parameter is increased, and makes a decision that the main factor of the optical signal quality degradation is a factor other than waveform distortion when the waveform distortion parameter is not increased. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30)
-
-
17. A system for determining the origin of optical signal quality degradation comprising:
-
optical signal amplitude histogram measurement means for obtaining an optical signal amplitude histogram from an optical signal under measurement; averaged Q-factor parameter measurement means for obtaining an averaged Q-factor parameter, which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained by said optical signal amplitude histogram measurement means; waveform distortion parameter measurement means for obtaining a waveform distortion parameter, which is another optical signal quality parameter calculated from the optical signal amplitude histogram obtained by said optical signal amplitude histogram measurement means; initial state storing means for storing into a storage medium at least one of an initial value and an initial characteristic of the averaged Q-factor parameter and that of the waveform distortion parameter at a system installation without optical signal quality degradation, which are obtained using said averaged Q-factor parameter measurement means and said waveform distortion parameter measurement means; and optical signal quality evaluation means for evaluating an optical signal quality degradation factor using a measurement value of the averaged Q-factor parameter and a measurement value of the waveform distortion parameter obtained by said averaged Q-factor parameter measurement means and said waveform distortion parameter measurement means, and using at least one of the initial values and initial characteristics stored in said storage medium in said initial state storing means, wherein said optical signal quality evaluation means makes a decision that a main factor of the optical signal quality degradation is the waveform distortion in the optical signal under measurement when the averaged Q-factor parameter is reduced and the waveform distortion parameter is increased, and makes a decision that the main factor of the optical signal quality degradation is a factor other than waveform distortion when the waveform distortion parameter is not increased.
-
-
18. A system for determining the origin of optical signal quality degradation comprising:
-
optical splitting means for splitting an optical signal under measurement; optical signal amplitude histogram measurement means for obtaining an optical signal amplitude histogram from a first optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting means; averaged Q-factor parameter measurement means for obtaining an averaged Q-factor parameter, which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained by said optical signal amplitude histogram measurement means; optical signal to optical noise power measurement means for measuring optical signal to optical noise power from a second optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting means; optical signal-to-noise ratio parameter obtaining means for obtaining an optical signal-to-noise ratio parameter, which is another optical signal quality parameter from the optical signal to optical noise power obtained by said optical signal to optical noise power measurement means; and optical signal quality evaluation means for evaluating an optical signal quality degradation factor using a measurement value of the averaged Q-factor parameter obtained by said averaged Q-factor parameter measurement means and a measurement value of the optical signal-to-noise ratio parameter obtained by said optical signal-to-noise ratio parameter obtaining means, wherein said optical signal quality evaluation means makes a decision as to whether a main factor of the optical signal quality degradation is the degradation in the optical signal-to-noise ratio or not by determining and evaluating both the averaged Q-factor parameter and the optical signal-to-noise ratio parameter.
-
-
19. A system for determining the origin of optical signal quality degradation comprising:
-
optical splitting means for splitting a optical signal under measurement; optical signal amplitude histogram measurement means for obtaining an optical signal amplitude histogram from a first optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting means; averaged Q-factor parameter measurement means for obtaining an averaged Q-factor parameter, which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained by said optical signal amplitude histogram measurement means; optical signal to optical noise power measurement means for measuring optical signal to optical noise power from a second optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting means; optical signal-to-noise ratio parameter obtaining means for obtaining an optical signal-to-noise ratio parameter, which is an optical signal quality parameter from the optical signal to optical noise power obtained by said optical signal to optical noise power measurement means; initial state storing means for storing into a storage medium at least one of an initial value and initial characteristic of the averaged Q-factor parameter and that of the optical signal-to-noise ratio parameter at a system installation without optical signal quality degradation, which are obtained using said averaged Q-factor parameter measurement means and said optical signal-to-noise ratio parameter obtaining means; and optical signal quality evaluation means for evaluating an optical signal quality degradation factor using a measurement value of the averaged Q-factor parameter obtained by said averaged Q-factor parameter measurement means and a measurement value of the optical signal-to-noise ratio parameter obtained by said optical signal-to-noise ratio parameter obtaining means, and using at least one of the initial values and initial characteristics of the averaged Q-factor parameter and that of the optical signal-to-noise ratio parameter at the system installation without optical signal quality degradation, which are stored in the storage medium in said initial state storing means, wherein said optical signal quality evaluation means makes a decision as to whether a main factor of the optical signal quality degradation is the degradation in the optical signal-to-noise ratio or not by determining and evaluating both the averaged Q-factor parameter and the optical signal-to-noise ratio parameter.
-
-
20. A system for determining the origin of optical signal quality degradation comprising:
-
optical splitting means for splitting an optical signal under measurement; optical signal amplitude histogram measurement means for obtaining an optical signal amplitude histogram from a first optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting means; optical signal to optical noise power measurement means for measuring optical signal to optical noise power from a second optical signal under measurement which is obtained by splitting the optical signal under measurement by said optical splitting means; waveform distortion parameter measurement means for obtaining a waveform distortion parameter1 which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained by said optical signal amplitude histogram measurement means; optical signal-to-noise ratio parameter obtaining means for obtaining an optical signal-to-noise ratio parameter, which is another optical signal quality parameter from the optical signal to optical noise power obtained by said optical signal to optical noise power measurement means; and optical signal quality evaluation means for evaluating an optical signal quality degradation factor using a measurement value of the waveform distortion parameter obtained by said waveform distortion parameter measurement means and a measurement value of the optical signal-to-noise ratio parameter obtained by said optical signal-to-noise ratio parameter obtaining means, wherein said optical signal quality evaluation means makes a decision as to whether a main factor of the optical signal quality degradation is the degradation in the optical signal-to-noise ratio or the waveform distortion by determining and evaluating both the waveform distortion parameter and the optical signal-to-noise ratio parameter.
-
-
21. A system for determining the origin of optical signal quality degradation comprising:
-
optical splitting means for splitting an optical signal under measurement; optical signal amplitude histogram measurement means for obtaining an optical signal amplitude histogram from a first optical signal under measurement obtained by splitting the optical signal under measurement in said optical splitting means; optical signal to optical noise power measurement means for measuring optical signal to optical noise power from a second optical signal under measurement which is obtained by splitting the optical signal under measurement by said optical splitting means; waveform distortion parameter measurement means for obtaining a waveform distortion parameter, which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained by said optical signal amplitude histogram measurement means; optical signal-to-noise ratio parameter obtaining means for obtaining an optical signal-to-noise ratio parameter, which is another optical signal quality parameter from the optical signal to optical noise power obtained by said optical signal to optical noise power measurement means; initial state storing means for storing into a storage medium at least one of an initial value and initial characteristic of the waveform distortion parameter and that of the optical signal-to-noise ratio parameter at a system installation without optical signal quality degradation, which are obtained using said waveform distortion parameter measurement means and said optical signal-to-noise ratio parameter obtaining means; and optical signal quality evaluation means for evaluating an optical signal quality degradation factor using a measurement value of the waveform distortion parameter obtained by said waveform distortion parameter measurement means and a measurement value of the optical signal-to-noise ratio parameter obtained by said optical signal-to-noise ratio parameter obtaining means, and using at least one of the initial values and initial characteristics of the waveform distortion parameter and that of the optical signal-to-noise ratio parameter at the system installation without optical signal quality degradation, wherein said optical signal quality evaluation means makes a decision as to whether a main factor of the optical signal quality degradation is the degradation in the optical signal-to-noise ratio or the waveform distortion by determining and evaluating both the waveform distortion parameter and the optical signal-to-noise ratio parameter.
-
-
22. A system for determining the origin of optical signal quality degradation comprising:
-
optical splitting means for splitting an optical signal under measurement; optical signal amplitude histogram measurement means for obtaining an optical signal amplitude histogram from a first optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting means; averaged Q-factor parameter measurement means for obtaining an averaged Q-factor parameters which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained by said optical signal amplitude histogram measurement means; optical signal to optical noise power measurement means for measuring optical signal to optical noise power from a second optical signal under measurement which is obtained by splitting the optical signal under measurement in said optical splitting means; waveform distortion parameter measurement means for obtaining a waveform distortion parameter, which is another optical signal quality parameter calculated from the optical signal amplitude histogram obtained by said optical signal amplitude histogram measurement means; optical signal-to-noise ratio parameter obtaining means for obtaining an optical signal-to-noise ratio parameter, which is another optical signal quality parameter from the optical signal to optical noise power obtained by said optical signal to optical noise power measurement means; and optical signal quality evaluation means for evaluating an optical signal quality degradation factor using a measurement value of the averaged Q-factor parameter obtained by said averaged Q-factor parameter measurement means, a measurement value of the waveform distortion parameter obtained by said waveform distortion parameter measurement means, and a measurement value of the optical signal-to-noise ratio parameter obtained by said optical signal-to-noise ratio parameter obtaining means, wherein said optical signal quality evaluation means makes a decision as to whether a main factor of the optical signal quality degradation is the degradation in the optical signal-to-noise ratio, the waveform distortion or not by determining and evaluating all the averaged Q-factor parameter, the waveform distortion parameter and the optical signal-to-noise ratio parameter.
-
-
23. A system for determining the origin of optical signal quality degradation comprising:
-
optical splitting means for splitting an optical signal under measurement; optical signal amplitude histogram measurement means for obtaining an optical signal amplitude histogram from a first optical signal under measurement, which is obtained by splitting the optical signal under measurement in said optical splitting means; averaged Q-factor parameter measurement means for obtaining an averaged Q-factor parameter1, which is an optical signal quality parameter calculated from the optical signal amplitude histogram obtained by said optical signal amplitude histogram measurement means; optical signal to optical noise power measurement means for measuring optical signal to optical noise power from a second optical signal under measurement obtained by splitting the optical signal under measurement in said optical splitting means; waveform distortion parameter measurement means for obtaining a waveform distortion parameter, which is another optical signal quality parameter calculated, from the optical signal amplitude histogram obtained by said optical signal amplitude histogram measurement means; optical signal-to-noise ratio parameter obtaininq means for obtaining an optical signal-to-noise ratio parameter, which is another optical signal quality parameter from the optical signal to optical noise power obtained by said optical signal to optical noise power measurement means; initial state storing means for storing into a storage medium at least one of an initial value and initial characteristic of the averaged Q-factor parameter, that of the waveform distortion parameter, and that of the optical signal-to-noise ratio parameter at a system installation without optical signal quality degradation, which are obtained using said averaged Q-factor parameter evaluation measurement means, said waveform distortion parameter evaluation measurement means and said optical signal-to-noise ratio parameter obtaining means; and optical signal quality evaluation means for evaluating an optical signal quality degradation factor using a measurement value of the averaged Q-factor parameter obtained by said averaged Q-factor parameter measurement means, a measurement value of the waveform distortion parameter obtained by said waveform distortion parameter measurement means, and a measurement value of the optical signal-to-noise ratio parameter obtained by said optical signal-to-noise ratio parameter obtaining means, and at least one of the initial values and initial characteristics of the averaged Q-factor parameter, the waveform distortion parameter, and the optical signal-to-noise ratio parameter at the system installation without optical signal quality degradation, which are stored into the storage medium by said initial state storing means, wherein said optical signal quality evaluation means makes a decision as to whether a main factor of the optical signal quality degradation is the degradation in the optical signal-to-noise ratio, the waveform distortion or not by determining and evaluating all the averaged Q-factor parameter, the waveform distortion parameter and the optical signal-to-noise ratio parameter.
-
Specification