Methods and systems for the performance analysis of fiber optic networks

• US 20070166032A1
• Filed: 01/10/2006
• Published: 07/19/2007
• Est. Priority Date: 01/10/2006
• Status: Active Grant

• Current Assignee: Ciena Corporation
• Original Assignee: Ciena Corporation
• Inventors: Frankel, Michael
• Granted Patent: US 8,761,610 B2
• Time in Patent Office: Days
• US Class Current: 398/9
• CPC Class Codes: H04B 10/2543 due to fibre non-linearities, e.g. Kerr effect
• CPC Class Codes: H04J 14/0201 Add-and-drop multiplexing
• CPC Class Codes: H04J 14/0227 Operation, administration, maintenance or provisioning [OAMP] of WDM networks, e.g. media access, routing or wavelength allocation
• CPC Class Codes: H04J 14/0278 WDM optical network architectures

Abstract

In general, the present invention provides novel approaches to signal propagation modeling that utilize the following: 1) geographic segmentation is applied by separating a large fiber optic network into individual non-overlapping segments, defined by optical add/drop placements; 2) impairment segmentation is applied, such that optical noise, self-phase, cross-phase, four-wave mixing, and other impairments are all treated separately; 3) each impairment is calculated by the most efficient approach to achieve the minimum required accuracy, the approaches being fully numeric, semi-analytic, or empirical; 4) impairment concatenation rules are applied to compute an overall impairment experienced by a signal that traverses more than one segment; and 5) impairment scaling rules are applied to rapidly estimate changes in configuration that can lead to improved performance (i.e. higher capacity, longer distance, or lower cost).

Claims

1. A method for the performance analysis of fiber optic networks, the method comprising:

given a fiber optic network of interest, applying geographic segmentation to the fiber optic network by separating the fiber optic network into a predetermined number of individual non-overlapping segments defined by one or more optical add/drop placements;

given a plurality of impairments of interest, applying impairment segmentation to the plurality of impairments such that each of the plurality of impairments is treated separately;

calculating each of the plurality of impairments using a predetermined method selected to achieve a predetermined minimum required accuracy;

applying one or more concatenation rules to compute an overall impairment experienced by a signal that traverses more than one segment; and

applying one or more impairment scaling rules to estimate changes in configuration that lead to improved fiber optic network performance.

2. The method of claim 1, wherein the plurality of impairments comprise a plurality of impairments selected from the group consisting of Optical Amplified Spontaneous Emission (ASE) noise accumulation associated with optical amplifiers, Self-Phase Modulation (SPM) associated with a single channel fiber nonlinearity, Cross-Phase Modulation (XPM) associated with a fiber nonlinearity coupling multiple adjacent channels, Four-Wave Mixing (FWM), Stimulated Raman Scattering (SRS), Multi-Path Interference (MPI), and Polarization Mode Dispersion (PMD).

3. The method of claim 1, wherein the predetermined method used to calculate each of the plurality of impairments comprises a method selected from the group consisting of a fully numeric method, a semi-analytic method, and an empirical method.

4. A system for the performance analysis of fiber optic networks, the system comprising:

given a fiber optic network of interest, a first algorithm operable for applying geographic segmentation to the fiber optic network by separating the fiber optic network into a predetermined number of individual non-overlapping segments defined by one or more optical add/drop placements;

given a plurality of impairments of interest, a second algorithm operable for applying impairment segmentation to the plurality of impairments such that each of the plurality of impairments is treated separately;

a third algorithm operable for calculating each of the plurality of impairments using a predetermined method selected to achieve a predetermined minimum required accuracy;

a fourth algorithm operable for applying one or more concatenation rules to compute an overall impairment experienced by a signal that traverses more than one segment; and

a fifth algorithm operable for applying one or more impairment scaling rules to estimate changes in configuration that lead to improved fiber optic network performance.

5. The system of claim 4, wherein the plurality of impairments comprise a plurality of impairments selected from the group consisting of Optical Amplified Spontaneous Emission (ASE) noise accumulation associated with optical amplifiers, Self-Phase Modulation (SPM) associated with a single channel fiber nonlinearity, Cross-Phase Modulation (XPM) associated with a fiber nonlinearity coupling multiple adjacent channels, Four-Wave Mixing (FWM), Stimulated Raman Scattering (SRS), Multi-Path Interference (MPI), and Polarization Mode Dispersion (PMD).

6. The system of claim 4, wherein the predetermined method used to calculate each of the plurality of impairments comprises a method selected from the group consisting of a fully numeric method, a semi-analytic method, and an empirical method.

7. A method for the performance analysis of fiber optic networks, the method comprising:

given a fiber optic network of interest, separating the fiber optic network into a plurality of segments;

performing an optical line amplifier (OLA) chain analysis of each of the plurality of segments; and

performing an impairment analysis of each of the plurality of segments,

wherein the impairment analysis comprises a plurality of impairment sub-analyses, each of the plurality of impairment sub-analyses limited to an analysis of one predetermined impairment.

8. The method of claim 7, wherein the optical line amplifier (OLA) chain analysis of each of the plurality of segments is performed in a parallel manner.

9. The method of claim 7, wherein the optical line amplifier (OLA) chain analysis of each of the plurality of segments is performed with load balancing.

10. The method of claim 7, wherein the impairment analysis of each of the plurality of segments is performed in a parallel manner.

11. The method of claim 7, wherein the impairment analysis of each of the plurality of segments is performed with load balancing.

12. The method of claim 7, wherein the impairments comprise impairments selected from the group consisting of Optical Amplified Spontaneous Emission (ASE) noise accumulation associated with optical amplifiers, Self-Phase Modulation (SPM) associated with a single channel fiber nonlinearity, Cross-Phase Modulation (XPM) associated with a fiber nonlinearity coupling multiple adjacent channels, Four-Wave Mixing (FWM), Stimulated Raman Scattering (SRS), Multi-Path Interference (MPI), and Polarization Mode Dispersion (PMD).

13. The method of claim 7, further comprising selecting and utilizing an initial per channel power in the fiber optic network.

14. The method of claim 13, further comprising selecting and utilizing a predetermined channel plan for the fiber optic network.

15. The method of claim 14, further comprising selecting and utilizing a predetermined channel plan cross-section for each of the plurality of segments of the fiber optic-network.

16. The method of claim 15, wherein performing the optical line amplifier (OLA) chain analysis of each of the plurality of segments provides a plurality of channel powers for the fiber optic network.

17. The method of claim 7, further comprising concatenating results obtained from performing the impairment analysis of each of the plurality of segments.

18. The method of claim 17, wherein concatenating the results obtained from performing the impairment analysis of each of the plurality of segments is performed in a parallel manner.

19. The method of claim 7, further comprising computing channel qualities (Q'"'"'s) for the fiber optic network.

20. The method of claim 7, further comprising applying scaling rules for one or more of the impairments in order to determine if the channel qualities (Q'"'"'s) are improved thereby.