Verification of path integrity in optical switch network
View Patent ↗To verify the integrity of optical paths through and among optical switches, optical signals are provided with co-propagating supplemental signals. The supplemental signals preferably have at least one characteristic which allows distinguishing one supplemental signal from another. Associated with a port of a switch, means are provided for detecting a supplemental signal and determining if the supplemental signal indicates that a desired optical signal is passing through the port as expected and desired. Means for imparting or changing the distinguishing characteristic of a supplemental signal may also be employed to facilitate verifying the passage of optical signals.
1. A method comprising:
detecting, at an output port of an optical switch, a supplemental signal that is co-propagated with an optical signal, wherein the supplemental signal includes one or more pre-determined attributes;
storing information about the one or more attributes of the detected supplemental signal to maintain a historical trend;
causing evaluation of the one or more pre-determined attributes of the detected supplemental signal for determining whether an alarm condition exists with respect to the optical signal; and
triggering the alarm condition based on the historical trend.
2. A method of claim 1 , further comprising:
determining whether the optical signal has been routed correctly by the optical switch based on the evaluation of the one or more pre-determined attributes.
3. A method of claim 1 , wherein the one or more pre-determined attributes specify a frequency characteristic, an amplitude characteristic, a phase characteristic, a modulation characteristic, data represented by modulation, or a combination thereof.
4. A method of claim 1 , wherein the attribute specifies information identifying the optical signal or an attribute of the optical signal.
5. A method of claim 1 , wherein the supplemental signal is modulated to provide as one of the attributes data associated with wavelength of the optical signal.
6. A method of claim 1 , wherein the supplemental signal includes a sub-carrier of the optical signal, the sub-carrier being used to frequency, phase, or amplitude modulate an electrical signal.
7. A method of claim 1 , wherein the one or more attributes are associated with a modulation applied electrically to an electrical signal to produce the optical signal.
8. An apparatus comprising:
an optical detector coupled to an optical switch and configured to detect, at an output port of the optical switch, a supplemental signal that is co-propagated with an optical signal, wherein the supplemental signal includes one or more pre-determined attributes and wherein information about the one or more attributes of the detected supplemental signal is stored to maintain a historical trend; and
an interface configured to cause evaluation of the one or more pre-determined attributes of the detected supplemental signal for determining whether an alarm condition exists with respect to the optical signal; wherein the alarm condition is triggered based on the historical trend.
9. An apparatus of claim 8 , wherein the evaluation of the one or more pre-determined attributes is performed to determine whether the optical signal has been routed correctly by the optical switch.
10. An apparatus of claim 8 , wherein the one or more pre-determined attributes specify a frequency characteristic, an amplitude characteristic, a phase characteristic, a modulation characteristic, data represented by modulation, or a combination thereof.
11. An apparatus of claim 8 , wherein the attribute specifies information identifying the optical signal or an attribute of the optical signal.
12. An apparatus of claim 8 , wherein the supplemental signal is modulated to provide as one of the attributes data associated with wavelength of the optical signal.
13. An apparatus of claim 8 , wherein the supplemental signal includes a sub carrier of the optical signal, the sub-carrier being used to frequency, phase, or amplitude modulate the electrical signal.
14. An apparatus of claim 8 , wherein the one or more attributes are associated with a modulation applied electrically to an electrical signal to produce the optical signal.
15. An apparatus comprising:
an optical matrix having a plurality of input ports and a plurality of output ports;
an optical detector coupled to one of the output ports and configured to detect a supplemental signal that is co-propagated with an optical signal at the output port of the optical matrix, wherein the supplemental signal includes one or more pre-determined attributes, and wherein information about the one or more attributes of the detected supplemental signal is stored to maintain a historical trend; and
a communication circuitry coupled to the optical detector and configured to cause evaluation of the one or more pre-determined attributes of the detected supplemental signal for determining whether an alarm condition exists with respect to the optical signal, wherein the alarm condition is triggered based on the historical trend.
16. An apparatus of claim 15 , further comprising:
another optical detector coupled to one of the input ports and configured to detect the supplemental signal prior to processing by the optical matrix.
17. An apparatus of claim 15 , further comprising:
an injector coupled to one of the input ports and configured to impart the one or more of the attributes to the supplemental signal.
18. An apparatus of claim 15 , further comprising:
a signal modifier coupled to one of the input ports and configured to modify the one or more of the attributes of the supplemental signal.