OTN Framer Dynamic Time Slot Reallocation for Wavelength Abnormalities

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Solution Overview

Problem

In OTUCn optical transport networks, multicarrier transmission using multiple optical subcarriers is vulnerable to abnormalities in optical wavelengths, which can lead to complete disruption of client signal traffic when an optical wavelength becomes unavailable.

Innovation Solution

A framer and framing method that dynamically reallocates time slots and adjusts transmission bands by identifying and avoiding affected time slots due to optical wavelength abnormalities, ensuring continued transmission of client signals using available optical wavelengths.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If multicarrier transmission using multiple optical subcarriers is implemented to increase transmission capacity, then transmission capacity is improved, but vulnerability to optical wavelength abnormalities increases

Engineering Contradiction:
Improvetransmission capacityVSAvoidvulnerability to optical wavelength abnormalities
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The patent segments client signal traffic into multiple logical paths and further divides each logical path into multiple time slots. This segmentation allows the system to distribute traffic across multiple optical subcarriers, so that when one wavelength experiences abnormality, only a portion of the traffic is affected rather than the entire signal being disrupted.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent dynamically changes the allocation parameters of time slots to optical subcarriers based on detected wavelength abnormalities. When abnormality is detected in a particular wavelength, the system reallocates time slots from affected logical paths to logical paths transmitted on healthy subcarriers, thereby adapting the transmission parameters to maintain reliability while preserving high transmission capacity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If time slots are reallocated to avoid abnormal optical wavelengths, then reliability is improved, but transmission efficiency may deteriorate

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidtransmission efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent implements dynamic time slot allocation where the mapping between time slots and optical subcarriers is not fixed but can be adjusted in real-time based on network conditions and wavelength availability. This dynamic approach allows the system to optimize both reliability and efficiency by reallocating resources only when necessary, rather than using static allocation that would either sacrifice efficiency or fail to adapt to abnormalities.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system continuously monitors the transmission status of optical wavelengths and provides feedback on detected abnormalities. Based on this feedback, the time slot allocation is adjusted to avoid affected wavelengths while maintaining optimal use of available capacity. This feedback mechanism ensures that reliability improvements through reallocation do not lead to unnecessary efficiency losses.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3208958B1Framer and framing method
Publication Date: 2019.08.21 NIPPON TELEGRAPH & TELEPHONE CORP
  • EP3208958B1 patent drawingFigure 1
  • EP3208958B1 patent drawingFigure 2
  • EP3208958B1 patent drawingFigure 3

AI summary

A framer in a transmission device that allocates time slots of an optical channel to a logical path, divides client signals received via the logical path to the time slots allocated to the logical path, and transmits the client signals by a plurality of optical subcarriers using optical wavelengths correlated with the time slots includes: a time slot allocating unit 54 configured to perform a process of reducing a transmission band of the logical path when some of the optical wavelengths are unavailable and changing the time slots allocated to the logical path depending on the reduced transmission band to avoid using the time slots corresponding to the unavailable optical wavelengths.