WDM Inter-Card Channel Protection via Direct Card Communication
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing inter-card and inner-card channel protection methods in WDM systems lack device-level protection and are costly, with limitations in reliability and speed due to reliance on system control units and dual-output/dual-input card configurations.
Innovation Solution
An inter-card channel protection method where signals are divided into primary and standby paths, allowing direct communication between cards for signal quality assessment and switching, enabling device-level protection without relying on the system control unit, with two cards managing switching operations independently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If inter-card channel protection is supported by system control unit, then protection switching can be implemented, but the switching speed is low due to communication overhead between cards and system control unit
Solution Approach 1:
The patent extracts the protection switching function from the system control unit and implements it directly in the receiving card. The receiving card independently detects signal quality and controls the client-side lasers of both cards, eliminating the need for communication with the system control unit during switching operations. This extraction of the switching function to the card level resolves the speed limitation caused by system control unit communication overhead.
2Reliability
If inner-card channel protection is used with dual-output/dual-input cards, then signal quality detection and path selection can be performed, but the card price is relatively high
Solution Approach 1:
The patent makes the receiving card multi-functional by enabling it to perform both signal reception and protection switching control. The receiving card not only receives signals but also detects signal quality from both primary and standby paths and controls the client-side lasers of both transmitting cards. This multi-functionality eliminates the need for specialized dual-output/dual-input cards, allowing the use of standard simplex cards and reducing overall system cost.
3Ease of operation
If system control unit is involved in protection switching, then centralized control can be achieved, but the protection is impossible when system control unit fails
Solution Approach 1:
The patent segments the protection switching function from the system control unit and distributes it to the card level. Each receiving card independently performs signal quality detection and switching control for its associated transmitting cards. This segmentation creates distributed protection capability that operates autonomously at each card, ensuring protection availability even when the system control unit fails, while maintaining centralized configuration capability.
Data Source
AI summary
Disclosed is an inter-card channel protection method in a wave-length division multiplexing system. At the transmitting end, signals from the client side are divided via a coupler into two paths which are delivered to two cards, respectively. The two paths of signal transmitted by the two cards are sent via different routes to the receiving end. At the receiving end, the two paths of signal enter two cards, respectively, and the two cards communicate with each other directly. The standby card submits the signal quality detected by a detecting device to the primary card. The switching control unit on the primary card issues the commands of switching on/off the client-side lasers to the standby card in accordance with a decision made. One of the client-side lasers on the primary card and standby card is switched on while the other is switched off. The merits of this method include: protection can be realized with failures of card or essential chips thereon; protection switching can still be conducted with failures of system control unit; and, direct transfer of switching conditions and switching commands between the two cards is faster than communications with a system control unit via mailbox respectively.