Clock Regeneration for Optical Communications Using Data Quantity Adjustment

Solution Overview

Problem

Conventional clock recovery techniques in optical communications networks are limited in handling diverse network configurations, requiring unique clock recovery requirements for different combinations of optical networks, and struggle to accurately regenerate client clock signals when interfacing with carrier networks using different clock signals.

Innovation Solution

A system and method that utilizes a clock signal generator and processor to calculate data quantities received and transmitted at an edge node, adjusting the clock source based on the difference between carrier and client clock signals, allowing for adaptable clock regeneration across various network configurations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional phase locked loop techniques are used for clock recovery, then clock signal can be recovered, but the system cannot handle diverse network configurations with different clock requirements

Engineering Contradiction:

Improveability to handle diverse network configurationsVSAvoidcomplexity of clock recovery system

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent implements a universal clock recovery system that can handle multiple network configurations through a single integrated apparatus. The system uses quantizers to measure data quantities at both carrier and client interfaces, and a frequency command controller that generates appropriate adjustment commands regardless of the specific network configuration. This multi-functional approach allows the same hardware to adapt to different optical network types (OTN, SONET, SDH, Ethernet) without requiring separate clock recovery systems for each configuration.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The system changes operational parameters dynamically based on network configuration. The frequency command controller adjusts the client clock signal frequency based on measured data quantities, and the system can modify its measurement and control parameters to accommodate different network types. This parameter-based adaptability allows the system to handle diverse configurations without increasing hardware complexity.

Inventive Principle:

Principle #35Parameter changes

2Measurement precision

If separate clock recovery systems are designed for each network configuration, then accurate clock recovery can be achieved, but the device complexity increases significantly

Engineering Contradiction:

Improveaccuracy of clock signal recoveryVSAvoidnumber of clock recovery systems required

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements a universal clock recovery system that can handle multiple network configurations through a single integrated apparatus. The system uses quantizers to measure data quantities at both carrier and client interfaces, and a frequency command controller that generates appropriate adjustment commands regardless of the specific network configuration. This multi-functional approach allows the same hardware to adapt to different optical network types (OTN, SONET, SDH, Ethernet) without requiring separate clock recovery systems for each configuration.

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The clock recovery system performs self-adjustment through automatic measurement and control. The quantizers automatically measure data quantities, and the frequency command controller automatically generates correction commands based on the measured differences. This self-service mechanism eliminates the need for manual configuration or multiple pre-designed systems for different network types, reducing overall device complexity while maintaining measurement precision.

Inventive Principle:

Principle #25Self-service

3Reliability

If the client clock signal is not adjusted, then simple transmission occurs, but data quantity mismatch between carrier and client interfaces causes transmission errors

Engineering Contradiction:

Improveaccuracy of data transmissionVSAvoidcomplexity of clock adjustment mechanism

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system implements feedback control by measuring the data quantity at both carrier and client interfaces using quantizers, comparing these measurements, and using the difference to generate frequency adjustment commands. This closed-loop feedback mechanism ensures that the client clock signal is adjusted to match the carrier interface data rate, preventing transmission errors while maintaining a relatively simple adjustment mechanism based on quantitative measurement and automatic correction.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS8437641B2Clock regeneration for optical communications

Publication Date: 2013.05.07 BAY MICROSYSTEMS INC

AI summary

A system and method for regenerating a client clock signal for use in optical communications is disclosed. The system and method involves using a carrier clock signal and a client clock signal to calculate quantities of data that are received and transmitted at an edge node and then adjusting a clock source in response to the difference between the calculated quantities of received and transmitted data.