Optical Transceiver Bandwidth Calculation for Transmission Capacity

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Solution Overview

Problem

Existing optical communication networks face challenges in accurately calculating the bandwidth of optical signals passing through multiple wavelength filters, leading to inaccuracies in determining the baud rate and entropy, which hinders the increase of transmission capacity.

Innovation Solution

Incorporating a bandwidth calculating unit and a test signal receiving unit in optical transceivers that send and receive test signals with narrower bandwidths than the wavelength filters, allowing for accurate calculation of signal bandwidth and determination of modulation rate and level.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If the bandwidth of optical signal is wider than the bandwidth of wavelength filter, then the optical signal can carry more information, but the bandwidth of the optical signal is narrowed to the same bandwidth as the bandwidth of the wavelength filter upon passage through the wavelength filter

Engineering Contradiction:
Improveinformation capacityVSAvoidbandwidth accuracy
Core Design Contradiction:
Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent changes the parameter of test signal bandwidth to be narrower than the wavelength filter bandwidth, enabling accurate bandwidth measurement through frequency response analysis. This parameter change allows the system to determine the actual bandwidth after filter passage without the signal being truncated by the filter's bandwidth limitations.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If all pass filters have the same bandwidth or different bandwidths, then the network configuration becomes flexible, but calculating the bandwidth of optical signal having passed through all pass filters only on the basis of the number of pass filters yields inaccurate results

Engineering Contradiction:
Improvenetwork configuration flexibilityVSAvoidbandwidth calculation accuracy
Core Design Contradiction:
Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent introduces a feedback mechanism where the bandwidth calculating unit uses the received test signal to determine the actual bandwidth of the transmission path. This feedback loop provides accurate bandwidth information that reflects the combined effect of all wavelength filters, enabling proper selection of baud rate and modulation level regardless of the number or configuration of filters.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If the bandwidth of optical signal is accurately calculated, then the baud rate and entropy can be properly determined, but existing methods that calculate bandwidth only on the basis of the number of pass filters cannot achieve accurate bandwidth determination

Engineering Contradiction:
Improvebandwidth measurement accuracyVSAvoidmeasurement system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent introduces a test signal as an intermediary to measure the bandwidth of the transmission path. This intermediary signal allows the bandwidth calculating unit to determine the actual bandwidth without directly analyzing the data signal, simplifying the measurement process while maintaining accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4080790B1Optical transmitter/receiver, transmission signal determination method, and optical communication system
Publication Date: 2024.07.10 MITSUBISHI ELECTRIC CORP
  • EP4080790B1 patent drawingFigure 1
  • EP4080790B1 patent drawingFigure 2
  • EP4080790B1 patent drawingFigure 3~5

AI summary

Optical transceivers (2-na), (3-nb) are configured to include a bandwidth calculating unit (15) that calculates, when test signals are sent to a transmission line (5) of an optical communication network from a test signal transmitting unit (11) and a test signal receiving unit (14) receives the test signals having passed through wavelength filters (6-1a), (6-2a), a bandwidth of the test signals having passed through the wavelength filters (6-1a), (6-2a) from the test signals received by the test signal receiving unit (14), the test signal transmitting unit (11) generating, as the test signals, a collection of a plurality of signals having a narrower bandwidth than a bandwidth of the wavelength filters (6-la), (6-2a) and having different frequencies, the wavelength filter being included in optical splitters (6-1), (6-2) inserted in transmission lines (5); and a transmission signal determining unit (16) that performs determination of a modulation rate of a transmission signal and a modulation level of the transmission signal depending on the bandwidth of the test signals calculated by the bandwidth calculating unit (15).