Optical Network Path Restoration Using Adjoint Weights
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In optical networks, restoring a connection after a link failure is time-consuming due to the need to adjust amplifier gain and laser wavelength, leading to potential service outages.
Innovation Solution
A method and system that assign adjoint weights to operational links in the original path, allowing for the determination of a new path with minimal changes in wavelength and amplifier gain, using connection costs to select the best alternate path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a new connection is set up after link failure in an optical network, then service restoration is achieved, but the process takes tens of seconds due to amplifier gain adjustment and laser retuning
Solution Approach 1:
The patent pre-establishes backup paths and pre-configures network elements before a failure occurs. When a link fails, the pre-planned backup path can be activated immediately without requiring real-time calculations or adjustments, thus eliminating the tens of seconds delay associated with real-time laser retuning and amplifier gain adjustment.
Solution Approach 2:
The patent changes the operational parameters of existing connections by allowing them to continue on the backup path without requiring laser retuning or amplifier gain adjustment. This is achieved by selecting a backup path that uses the same wavelength and infrastructure, thereby avoiding the time-consuming parameter changes that would otherwise be required.
2Reliability
If all connections along the original path are torn down and reestablished, then the path is reestablished, but the process is complicated and time-consuming in optical networks
Solution Approach 1:
The patent segments the connection restoration process into two independent parts: (1) detecting the failed link and (2) activating the pre-established backup path. This segmentation avoids the complex process of tearing down and reestablishing all connections along the original path, as the backup path is already configured and ready for immediate activation.
Solution Approach 2:
The patent introduces a backup path as an intermediary solution between the failed link and the required service restoration. This intermediary backup path is pre-configured and requires no complex real-time adjustments, thereby simplifying the restoration process compared to directly reestablishing the original path.
3Reliability
If laser retuning is performed to restore the connection, then the connection can be reestablished, but it takes tens of seconds which causes service disruption
Solution Approach 1:
The patent performs laser retuning and wavelength configuration in advance during backup path setup, rather than during failure restoration. This preliminary action ensures that when a link fails, the backup path is already configured with the correct laser wavelengths, eliminating the need for time-consuming real-time retuning.
Solution Approach 2:
The patent creates a copy of the original path configuration as a backup path that uses the same wavelength and infrastructure. This copy is pre-configured and ready for immediate activation, avoiding the need to perform time-consuming laser retuning operations during failure restoration.
Data Source
AI summary
A method and system of determining a new path through an optical network from a source node to a destination node when a link in an original path fails are disclosed. When a fault on a link is detected, adjoint weights are assigned to each operational link for each node on the original path. A connection cost is determined for each node based on the adjoint weights of the links connected to the node. A new path through the optical network is determined based at least in part on the adjoint weights and the connection costs.