OTN Traffic Protection via Two-Fiber OMS Shared Ring
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Solution Overview
Problem
Current optical transport network (OTN) protection methods, such as two-fiber MS shared protection rings, are limited to the SDH field, restrict the number of nodes to 16, and introduce unendurable delays in transoceanic applications due to insufficient line performance monitoring and unreliable protection switching based on optical power.
Innovation Solution
A method and node apparatus for OTN traffic protection using a two-fiber Optical Multiplex Section (OMS) shared protection ring, where channels in one fiber are set as working channels and an equal number in the opposite fiber as protection channels, with bridging and switching nodes determined to implement reliable traffic protection, utilizing wavelength-division multiplexing and ODU cross-connection units for efficient signal management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If two-fiber MS shared protection ring is adopted in SDH field, then traffic protection is realized, but the number of nodes is limited to at most 16
Solution Approach 1:
The patent changes the parameter of node identification from 4-bit (16 nodes) to 8-bit (256 nodes) in the APS protocol, enabling the protection ring to support up to 256 nodes while maintaining the same protection mechanism
Solution Approach 2:
The patent makes the protection ring mechanism universal by extending it from SDH to OTN fields, allowing the same two-fiber shared protection ring architecture to support both SDH and OTN traffic types with a unified management approach
2Reliability
If bridging and switching are implemented at both end nodes of the broken fiber, then traffic protection is achieved, but unendurable delay is introduced for transoceanic applications
Solution Approach 1:
The patent pre-establishes protection paths and configurations before failures occur, allowing for faster switching decisions when failures happen, thereby reducing the protection switching delay compared to reactive approaches
Solution Approach 2:
The patent introduces an intermediary control mechanism that coordinates bridging and switching operations, enabling more efficient traffic redirection with reduced delay by optimizing the switching control logic
3Ease of operation
If optical power is used as switching initiating criteria, then protection switching can be triggered, but line performance monitoring is insufficient and signal quality detection is not fully carried out
Solution Approach 1:
The patent implements feedback mechanisms through comprehensive line performance monitoring that continuously detects signal quality parameters, providing accurate feedback for reliable protection switching decisions based on actual signal conditions rather than just optical power
Solution Approach 2:
The patent replaces simple optical power detection with a more sophisticated signal quality detection system that measures multiple parameters including OSNR, enabling more precise and reliable protection switching triggering
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution simplifies network protection, reduces wavelength occupation, eliminates OSNR degradation, supports up to 256 nodes, and provides reliable protection with optimal path selection, especially for ultra-long haul and transoceanic applications by implementing bridging and switching at source and destination nodes.
Implementation Method 1
utilizing wavelength-division multiplexing and ODU cross-connection units for efficient signal management
Implementation Method 2
using optical fibers to transmit signals has become a mainstream of network traffic transmission
Data Source
AI summary
Disclosed is a method and node apparatus for traffic protection of Optical Transport Network (OTN), including: setting a part of channels in one fiber as working channels used for carrying traffic in need of protection, and setting a part of channels in the other fiber with a reverse transmission direction as protection channels, the number of which is equal to that of the working channels, to form a one-to-one protection for the working channels; when a failure in an optical line of OTN is detected, determining a bridging node and a switching node in accordance with pre-designated protection strategy, bridging and switching the traffic to be transmitted through the failed optical line between the working channels and the protection channels at the determined bridging node and switching node. This invention can realize OTN protection based on two-Fiber OMS shared protection ring, and improve the transmission reliability of optical networks.