Clock Frequency Range Control for Seamless Path Switching

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing non-instantaneous interruption switching devices face challenges in quickly adjusting clock frequency to eliminate delay differences between active and backup systems, leading to prolonged maintenance operation times, especially with increasing path length differences, as they rely solely on reception side clock frequency adjustments without considering transmission side deviations.

Innovation Solution

A transmission apparatus with a system that includes a clock frequency control unit, frequency adjustment range calculation unit, and output speed control, allowing for simultaneous adjustments on both transmission and reception sides to determine an optimal clock frequency adjustment range, thereby shortening the delay difference adjustment time by considering frequency deviations on both sides.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the frequency adjustment range is made small to ensure frequency deviation accuracy, then the clock frequency adjustment precision is improved, but the maintenance operation time required for adjustment increases with increasing delay time difference

Engineering Contradiction:
Improvefrequency deviation accuracyVSAvoidmaintenance operation time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent applies dynamics by making the frequency adjustment range adaptive rather than fixed. The range is dynamically determined based on the measured delay time difference between active and backup systems. When delay difference is large, a larger frequency adjustment range is permitted; when delay difference is small, a tighter range is used. This resolves the contradiction by allowing the system to optimize between adjustment precision and adjustment speed based on real-time conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of frequency adjustment range from a fixed value to a variable that depends on the delay time difference. By calculating the appropriate adjustment range based on the measured delay, the system can efficiently eliminate delays without unnecessarily constraining the adjustment process, thereby reducing maintenance operation time while maintaining sufficient frequency deviation accuracy.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If the frequency adjustment range is made small to ensure frequency deviation accuracy, then the clock frequency adjustment precision is improved, but the adjustment speed decreases

Engineering Contradiction:
Improvefrequency deviation accuracyVSAvoidadjustment speed
Core Design Contradiction:
Measurement precisionVSSpeed

Solution Approach 1:

The system dynamically adjusts the frequency adjustment range based on the measured delay time difference. This allows the adjustment process to proceed at optimal speed for each specific condition, rather than being constrained by a fixed conservative range. The adjustment speed increases when larger ranges are permitted by the calculated parameters.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

By changing the frequency adjustment range parameter from fixed to variable, the system enables faster adjustment when conditions permit. The calculated range allows the clock frequency to be adjusted more aggressively when needed, improving adjustment speed without sacrificing necessary precision.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If only reception side clock frequency adjustment is performed, then the device complexity is reduced, but the delay difference adjustment time increases

Engineering Contradiction:
Improveclock system configurationVSAvoiddelay difference adjustment time
Core Design Contradiction:
Device complexityVSLoss of time

Solution Approach 1:

The patent applies preliminary action by measuring and considering the transmission side clock frequency deviation before performing the frequency adjustment. This advance knowledge allows the reception side to calculate the optimal adjustment range more accurately, reducing the time needed to eliminate delay differences while maintaining appropriate precision.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses feedback from the transmission side clock frequency measurement to guide the reception side adjustment process. By incorporating transmission side information into the adjustment calculation, the system achieves faster convergence without significantly increasing overall device complexity, as the additional measurement capability is localized to the transmission side.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3876471B1Transmission device and transmission system
Publication Date: 2023.09.06 NIPPON TELEGRAPH & TELEPHONE CORP
  • EP3876471B1 patent drawingFigure 1~2
  • EP3876471B1 patent drawingFigure 3
  • EP3876471B1 patent drawingFigure 4

AI summary

A first reception processing unit performs a process of receiving a first signal transmitted on a first transmission line, a second reception processing unit performs a process of receiving a second signal transmitted on a second transmission line, and an output speed control unit controls output speeds of the first signal and the second signal subjected to the reception process. A system switching unit selects and outputs the first signal or the second signal subjected to a reception process, and an output processing unit performs a process for output to another apparatus on the output from the system switching unit. A reception side clock output unit outputs a clock signal giving a processing timing of each process, and a clock frequency control unit adjusts a frequency of the clock signal giving the processing timing to the output processing unit. A frequency adjustment range calculation unit calculates an adjustment range of the frequency based on frequency deviation accuracy of the reception side clock output unit, frequency deviation accuracy of a transmission side clock output unit that outputs a clock signal giving a processing timing to a transmission process at a transmission apparatus on the transmission side, and a prescribed value of a frequency deviation.