Adaptive Routing for Optical Networks on Chip

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Solution Overview

Problem

In Optical Networks on Chip (ONoC), especially in Wavelength Division Multiplexing (WDM) based systems, increasing numbers of optical devices lead to significant signal losses and crosstalk, causing transmission quality deterioration and errors, while thermal changes further affect signal quality due to thermo-optic effects.

Innovation Solution

An adaptive routing method using Q-learning that evaluates path quality based on signal-to-noise ratio (SNR) and ambient temperature changes, updating Q tables to determine optimal next-hop nodes and transmission paths, thereby comprehensively considering crosstalk, losses, and thermal sensitivity factors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the number of optical devices is increased to enhance ONoC functionality, then device versatility is improved, but signal loss and crosstalk increase causing transmission quality deterioration

Engineering Contradiction:
Improvedevice versatilityVSAvoidtransmission quality
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent implements dynamic routing that adapts to changing network conditions by continuously monitoring signal quality metrics (SNR, crosstalk levels, temperature) and adjusting path selection in real-time. This allows the system to maintain reliable transmission despite increasing device density by dynamically avoiding degraded paths.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system employs feedback mechanisms where transmission quality metrics are continuously measured and fed back to the routing controller. This feedback loop enables the system to learn from actual transmission performance and adjust routing decisions to avoid paths suffering from excessive loss or crosstalk, thereby maintaining reliability as device count increases.

Inventive Principle:
Principle #23Feedback

2Productivity

If more optical devices are deployed to improve network capacity, then productivity is enhanced, but harmful factors such as crosstalk and losses increase

Engineering Contradiction:
Improvenetwork capacityVSAvoidcrosstalk and signal losses
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces an intelligent routing intermediary that mediates between network capacity requirements and signal quality constraints. This intermediary evaluates multiple path options considering crosstalk and loss factors, selecting optimal routes that maintain high network capacity while avoiding paths where harmful factors exceed acceptable thresholds.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system dynamically changes routing parameters (path selection, wavelength assignment) based on measured signal quality conditions. When crosstalk or losses exceed acceptable levels on certain paths, the system transitions to alternative paths with better signal characteristics, thereby maintaining network capacity while mitigating harmful effects.

Inventive Principle:
Principle #35Parameter changes

3Temperature

If ambient temperature changes occur, then thermal effects are introduced, but transmission quality deteriorates due to resonant wavelength shifts

Engineering Contradiction:
Improveambient temperatureVSAvoidtransmission quality
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent implements preliminary temperature compensation by monitoring ambient temperature changes and proactively adjusting routing decisions before significant wavelength drift occurs. The system predicts potential transmission quality issues based on temperature trends and pre-selects alternative paths that are less sensitive to thermal effects or have better current signal conditions.

Inventive Principle:
Principle #10Preliminary action

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 approach effectively guarantees optical signal quality and improves ONoC performance by adaptively routing services, mitigating transmission errors and quality deterioration caused by device density and thermal effects.

Implementation Method 1

due to a thermo-optic effect, a resonant wavelength of a silicon-based microring resonator may be shifted with changes of an ambient temperature

Methodology Applied
Scientific EffectThermo-optic effect:

Data Source

PatentUS11855689B1Routing method and related device
Publication Date: 2023.12.26 BEIJING UNIV OF POSTS & TELECOMM
  • US11855689B1 patent drawing
  • US11855689B1 patent drawing
  • US11855689B1 patent drawing

AI summary

A routing method includes: determining a path quality between a first node and each of second nodes in a service to be transmitted through a path quality evaluation model; where, the second node is one next-hop node of the first node; and the path quality evaluation model is constructed according to a signal-to-noise ratio SNR and an ambient temperature change; determining an optimal next-hop node from second nodes according to the path quality; updating a Q table of the first node according to the optimal next-hop node; taking the optimal next-hop node as a new first node; returning to the step of determining a path quality between a first node and each of second nodes until the new first node is a destination node of the service to be transmitted; and determining a transmission path of the service to be transmitted according to the Q table.