SDN Controller Reroutes Services for Optical Wavelength Defragmentation
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Solution Overview
Problem
Current methods for optical wavelength defragmentation in optical networks require special signal replication functions in transmission apparatuses, increasing costs and being unsuitable for single optical wavelengths, and cause instantaneous interruptions during wavelength changes.
Innovation Solution
A control apparatus and method that dynamically reroutes services and changes wavelength bands between transmission apparatuses in optical networks without requiring special signal replication functions, using an SDN controller to detour services and adjust wavelength bands without interrupting communication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If optical wavelength defragmentation is performed by changing wavelength band in transmission apparatus, then fragmentation is resolved, but client signal is instantaneously interrupted
Solution Approach 1:
The system performs preliminary route detection and service detour setup before wavelength change occurs. The control apparatus identifies alternative routes and pre-configures detour paths, ensuring service continuity is maintained during the wavelength defragmentation process.
Solution Approach 2:
The control apparatus acts as an intermediary between the wavelength change operation and the service traffic. It coordinates the detour routing and wavelength switching, managing the transition smoothly without causing service interruption.
2Reliability
If signal replication function is added to transmission apparatus to prevent interruption, then service continuity is maintained, but apparatus cost increases
Solution Approach 1:
The signal replication function is extracted from the transmission apparatus and relocated to the control apparatus. This allows the transmission apparatus to remain simple while the control apparatus handles the complex routing and replication logic, reducing device complexity at the transmission end.
Solution Approach 2:
The control apparatus serves as an intermediary that performs signal replication and route management externally, eliminating the need for complex internal replication functions in the transmission apparatus.
3Reliability
If wavelength band change is performed in subcarrier with multiple optical wavelengths, then defragmentation is achieved, but subcarrier must be configured in advance limiting applicability
Solution Approach 1:
The control apparatus implements a universal wavelength defragmentation mechanism that works with both single optical wavelengths and subcarriers containing multiple wavelengths. The system dynamically determines the appropriate defragmentation approach based on the input type, making it universally applicable across different network configurations.
Solution Approach 2:
The system dynamically adapts its defragmentation strategy based on whether a single wavelength or multiple wavelengths are involved. It can switch between different operational modes without requiring pre-configuration, providing flexible and dynamic wavelength management.
Data Source
AI summary
A control apparatus includes an optical wavelength change control unit that specifies, in response to a request to change a wavelength band of a first optical wavelength path used by a first transmission apparatus and a second transmission apparatus to a wavelength band of a second optical wavelength path, a first route between routers which is affected by the request and a service which uses the first route and that specifies a second route between the routers which detours the specified service; a router control unit that transmits a request to detour the specified service to the second route, to a start-point router and an end-point router on the first route; and a transmission apparatus control unit that transmits a request to change the wavelength band of the first optical wavelength path to the wavelength band of the second optical wavelength path, to the first transmission apparatus and the second transmission apparatus.