Optical Node Information Distribution in WDM Networks
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Solution Overview
Problem
In WDM optical networks, the wavelength continuity constraint and cross-connect restrictions complicate the computation of paths, leading to inefficient channel establishment and suboptimal resource utilization, particularly in Automatic Switched Optical Networks (ASON) integrated with RWA, where simultaneous route selection and wavelength assignment are challenging due to the lack of effective information distribution mechanisms.
Innovation Solution
A method and system for distributing optical node information in WDM optical networks, where an optical node generates and distributes an information bit stream based on node information, including potential wavelength connectivity and occupancy status, using an extended IGP protocol, to facilitate accurate and efficient route and wavelength assignment by reducing data volume and enhancing synchronization across the network.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of information
If node information is distributed using conventional flooding methods, then all network elements receive complete status information, but the data volume increases significantly causing slow computation and low efficiency
Solution Approach 1:
The patent segments node information into two distinct types: Link State Information (LSI) containing static topology data and Status Information (SI) containing dynamic resource state. This segmentation allows different information to be processed at different times and in different formats, reducing the computational burden on network elements while maintaining information completeness for path computation.
Solution Approach 2:
The patent applies preliminary action by distributing Link State Information in advance before actual connection requests are processed. The LSI is updated and flooded proactively, so that when connection requests arrive, the necessary topological information is already available, eliminating the need for real-time flooding of complete node information and significantly reducing computation time.
2Ease of manufacture
If wavelength continuity constraint is strictly enforced, then optical channel setup is simplified, but route selection flexibility is reduced leading to suboptimal resource utilization
Solution Approach 1:
The patent introduces dynamics by enabling dynamic wavelength assignment that adapts to network conditions. The system can switch between strict wavelength continuity mode and flexible wavelength assignment mode depending on the connection request characteristics and available resources, allowing optimal resource utilization while maintaining simplicity when possible.
Solution Approach 2:
The patent changes the parameter of wavelength assignment from fixed/strict to flexible/dynamic. By modifying how wavelengths are assigned based on real-time network state information, the system can satisfy wavelength continuity constraints when beneficial while allowing flexibility to maximize resource utilization, thus resolving the contradiction between simplicity and efficiency.
3Reliability
If separate route selection and wavelength assignment is performed, then wavelength continuity constraint is easier to satisfy, but connection establishment time increases significantly
Solution Approach 1:
The patent merges route selection and wavelength assignment into a unified path computation process. By combining these two functions and processing them simultaneously using the distributed Link State Information, the system achieves both wavelength continuity satisfaction and fast connection establishment, eliminating the sequential processing bottleneck while maintaining reliability.
Data Source
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AI summary
A method for distributing node information, including the following steps: an optical node generates an information bit stream based on its own node information; the optical node distributes the information bit stream it generates and a wavelength sequence corresponding to the node information. According to the embodiments of the present invention, an information bit stream is generated based on the node information of an optical node so as to greatly reduce the volume of data in the node information distributed by an optical node.