Hybrid Optical Switch for SDN Traffic Utilization

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Solution Overview

Problem

Optical communication networks face suboptimal resource utilization due to fluctuating traffic volumes, leading to inefficiencies in network resource management, especially in nodes with high traffic bursts exceeding maximum throughput capacity.

Innovation Solution

A hybrid optical switch that dynamically switches optical channels based on utilization factors, using Optical Transport Network (OTN) switches for low utilization channels and reconfigurable optical add/drop multiplexers (ROADM) for high utilization channels, optimizing channel utilization and reducing electrical switching workload.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Speed

If optical channels are always switched optically using ROADM, then switching speed is maintained high, but device complexity and cost increase due to requiring optical switching capacity for all channels

Engineering Contradiction:
Improveswitching speedVSAvoiddevice complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The system dynamically adjusts the switching method for each optical channel based on its utilization factor. When utilization is high, optical switching is used to maintain speed. When utilization is low, electrical switching is used to reduce complexity. This dynamic adaptation resolves the contradiction by making the switching mechanism flexible rather than static.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Different switching strategies are applied to different optical channels based on their individual utilization characteristics. High-utilization channels receive optical switching treatment while low-utilization channels receive electrical switching treatment. This localized quality assignment optimizes the system by matching the switching method to the specific needs of each channel.

Inventive Principle:
Principle #3Local quality

2Device complexity

If optical channels are always switched electrically using OTN switch, then device complexity is reduced, but productivity decreases due to the unwrapping and rewrapping process

Engineering Contradiction:
Improvedevice complexityVSAvoidproductivity
Core Design Contradiction:
Device complexityVSProductivity

Solution Approach 1:

The system dynamically selects between electrical and optical switching based on channel utilization. Electrical switching is used for low-utilization channels to reduce complexity, while optical switching is used for high-utilization channels to maintain productivity. This dynamic selection resolves the contradiction by optimizing the trade-off based on actual traffic conditions.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Different switching approaches are applied locally to different channels based on their utilization factors. Channels with high utilization factors receive optical switching to maintain high productivity, while channels with low utilization factors receive electrical switching to reduce device complexity. This localized differentiation resolves the contradiction.

Inventive Principle:
Principle #3Local quality

3Productivity

If optical channels with low utilization are unwrapped and switched electrically, then optical channel utilization is improved, but loss of time increases due to the unwrapping and rewrapping process

Engineering Contradiction:
Improveoptical channel utilizationVSAvoidloss of time
Core Design Contradiction:
ProductivityVSLoss of time

Solution Approach 1:

The system applies electrical switching (unwrapping) only to optical channels with low utilization factors, rather than all channels. This partial application of the unwrapping process improves overall optical channel utilization by freeing up capacity on underutilized channels, while minimizing the time loss associated with unwrapping and rewrapping operations.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The system changes the switching parameter (optical vs. electrical) based on the utilization factor parameter of each channel. By monitoring and responding to changes in utilization parameters, the system optimizes channel utilization while managing the time overhead of format conversion.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If optical channels with high utilization are switched optically, then productivity is maintained high, but device complexity increases due to requiring optical switching capacity

Engineering Contradiction:
ImproveproductivityVSAvoiddevice complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system dynamically allocates optical switching resources only to channels with high utilization factors, rather than maintaining optical switching capacity for all channels. This dynamic resource allocation maintains high productivity for critical channels while reducing overall device complexity by scaling back optical switching requirements during periods of lower overall demand.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Optical switching capacity is allocated locally to specific channels based on their utilization needs. High-utilization channels receive optical switching treatment to maintain productivity, while low-utilization channels are handled electrically to reduce device complexity. This localized resource allocation resolves the contradiction.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP3231113B1Hybrid optical switch for software-defined networking
Publication Date: 2022.05.25 ALCATEL LUCENT SA
  • EP3231113B1 patent drawingFigure 1
  • EP3231113B1 patent drawingFigure 2
  • EP3231113B1 patent drawingFigure 3

AI summary

We disclose a hybrid optical switch configured to switch optical channels based on their respective utilization factors. In an example embodiment, optical channels having relatively low utilization factors are unwrapped down to payload units, which are then switched electrically, e.g., using an Optical-Transport-Network (OTN) switch, in a manner that tends to increase the utilization factors of the optical channels that carry the switched payload units. In contrast, optical channels having relatively high utilization factors are switched optically, e.g., using a reconfigurable optical add/drop multiplexer, without being unwrapped. The hybrid optical switch may advantageously be deployed in a network node subjected to relatively high traffic-volume fluctuations because the switch tends to improve optical-channel utilization when the traffic volume is relatively low and to decrease the workload of the corresponding OTN switch when the traffic volume is relatively high.