APS Service Channel Switching Synchronization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In the context of automatic protection switching (APS) in Ethernet networks, users cannot determine the wait-to-restore (WTR) state of the first recovered side before service is switched back to the working channel, and if the WTR time on the first recovered side is greater than that on the second recovered side, the first recovered side may switch back prematurely, not meeting customer requirements for timely recovery.
Innovation Solution
Implementing a method where the first recovered side reaches a WTR state upon receiving information from the second recovered side, and both sides switch back to the working channel only after exhausting their respective WTR times, ensuring synchronization and adherence to the customer's recovery time frame.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the first recovered side does not enter the WTR state and switches back to the working channel immediately upon recovery, then the switching speed is improved, but the reliability of meeting customer recovery time requirements deteriorates
Solution Approach 1:
The patent applies preliminary action by having the first recovered side enter the WTR state in advance upon receiving WTR entry notification from the second recovered side, before the actual switchback occurs. This ensures that the WTR timing is properly initialized and the switchback will occur at the correct time, resolving the contradiction between fast switching and reliable timing.
Solution Approach 2:
The patent uses feedback mechanisms where the second recovered side sends WTR entry notification to the first recovered side, and both sides exchange WTR timeout notification upon timeout. This feedback loop ensures both sides are synchronized and the switchback occurs at the correct time, maintaining reliability while enabling fast switching.
2Device complexity
If the first recovered side enters the WTR state independently without synchronization, then the device complexity is reduced, but the consistency of switching behavior between the two sides deteriorates
Solution Approach 1:
The patent introduces WTR entry notification and WTR timeout notification as intermediary signals between the two recovered sides. These notifications coordinate the WTR state entry and timeout events, ensuring both sides maintain consistent switching behavior without requiring complex centralized state management.
3Productivity
If the first recovered side switches back before the WTR time expires when its WTR time is longer, then the productivity is improved, but the adherence to customer requirements deteriorates
Solution Approach 1:
The patent employs feedback through WTR timeout notification exchange between the two recovered sides. When the second recovered side times out first, it sends a notification to the first recovered side, forcing it to wait until its own WTR time expires before switching back. This ensures precise timing control and adherence to customer requirements while maintaining high recovery efficiency.
Data Source
Figure 1~2
Figure 3
Figure 4~6
AI summary
The present invention relates to the field of communication technologies, and discloses a method and a system for switching an APS service channel, and an automatic protection switching device. The method includes: a first recovered side reaches a wait-to-restore (WTR) state when the first recovered side receives information about transition to the WTR state from a second recovered side if a current state of the first recovered side is a first No Request (NR) state and if a state prior to transition to the first NR state is a Signal Fail (SF) state; and the first recovered side reaches a second NR state upon expiry of a WTR time of the first recovered side after receiving WTR time expiry information sent by the second recovered side. Therefore, the user can know the WTR state of the first recovered side clearly; and, when the WTR time set on the first recovered side is greater than the WTR time set on the second recovered side, the service is not switched back to the working channel until the WTR time of the first recovered side expires, thereby meeting the customer requirement of switching back to the working channel upon expiry of the WTR time after the working channel recovers from the fault.