Technique for monitoring optical networks

1. A method for managing at least a network portion of an optical communication network, the method comprising:

obtaining, at different times, threshold samples for discriminating a digital optical signal being propagated via said at least a network portion of the optical communication network;

determining changes occurring in decision thresholds based on the obtained threshold samples, and deriving therefrom a temporal decision threshold behavior at said at least a network portion of the optical communication network;

comparing the derived temporal decision threshold behavior with previously stored reference decision threshold behaviors to identify an event associated with a potential problem in said at least a network portion of the optical communication network; and

providing management information based on the identified event.

2. A method according to claim 1 , wherein the potential problem is associated with a specific channel operative at said at least a network portion of the optical communication network.

3. The method according to claim 1 , further comprising a step of affecting a change in the at least a network portion of the optical communication network based on the provided management information and monitoring a behavior of the at least a network portion of the optical communication network after said change has been affected.

4. The method according to claim 1 , further comprising a preliminary step of forming a data base for storing the reference decision threshold behaviors, each reference decision threshold behavior being associated with a different behavior of one of the decision thresholds.

5. The method according to claim 4 , wherein each of said stored reference decision threshold behavior represents a unique operating condition of said at least a network portion of the optical communication network.

6. The method according to claim 4 , wherein at least one of the reference decision threshold behaviors comprises one or more of the following: a typical shape of a time diagram, a spectral feature, a temporal feature, a statistical feature, and a noise-related feature.

7. The method according to claim 4 , wherein each of said reference decision threshold behaviors is associated with at least one of the following: a specific behavior manifesting a loss of said optical signal in a specific optical channel; a specific behavior indicating degradation problems in said specific optical signal of the specific optical channel; a specific behavior indicating dispersion in an optical line carrying said optical signal; another specific behavior indicating polarization mode dispersion; and non-linearity in the optical line carrying said optical signal.

8. The method according to claim 1 , further comprising identifying typical scenarios in said at least a network portion of the optical communication network, and identifying a decision threshold behavior associated with each of said typical scenarios.

9. The method according to claim 1 , wherein the optical signal is a binary signal.

10. A system for managing an optical communication network by monitoring at least a network portion of the optical communication network, the system comprising:

a sampler for obtaining threshold samples, at different times, for discriminating a digital optical signal being propagated via said at least a network portion of the optical communication network; and

at least one processing device configured to:

determine changes occurring in decision thresholds based on the obtained threshold samples, and to derive therefrom a temporal decision threshold behavior at said at least a network portion of the optical communication network;

compare the obtained temporal decision threshold behavior with previously stored reference decision threshold behaviors, and identify an event associated with a potential problem in said at least a network portion of the optical communication network; and

provide management information based on the identified event.

11. The system according to claim 10 , wherein the potential problem is associated with a specific channel operative at said at least a network portion of the optical communication network.

12. A software product comprising computer implementable instructions and/or data for carrying out the method according to claim 1 , and stored on a non-transitory computer readable storage medium, wherein that the software is capable of enabling operations of said method when used in a computer system.