CDC Optical Network Architecture Using Super-Channel Multiplexing

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Solution Overview

Problem

Current optical network architectures with CDC capabilities face scalability issues, high costs, and single points of failure, particularly with multi-cast switch and optical cross connect switch-based structures, which also limit protection schemes to slower 1:1 restoration.

Innovation Solution

A modular CDC optical network architecture incorporating a super-channel multiplexer and optical cross connect switches, with dual-plane redundancy and dual-cast multiplexers, enabling colorless, directionless, and contentionless operations, and supporting 1+1 protection for rapid restoration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multi-cast switch (MCS) based structure is used for CDC optical network, then CDC capabilities are achieved, but scalability and cost efficiency deteriorate when ROADM node includes more than four directions

Engineering Contradiction:
ImproveCDC capabilitiesVSAvoidscalability
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The patent segments the optical network functions by introducing separate OXC switches for super-channel routing and separate WSS-based ROADMs for wavelength-level add-drop operations. This segmentation allows each component to be optimized independently, enabling the system to scale to more than four directions without the limitations of integrated MCS architectures.

Inventive Principle:
Principle #1Segmentation

2Reliability

If OXC switch based structure is used for CDC optical network, then CDC capabilities are achieved, but scalability deteriorates due to very large OXC switches and single points of failure

Engineering Contradiction:
ImproveCDC capabilitiesVSAvoidscalability
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent divides the monolithic OXC function into separate components: a dedicated OXC switch for super-channel routing and multiple WSS-based ROADMs for wavelength management. This segmentation reduces the size and complexity of each individual switch, eliminates single points of failure, and improves scalability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces dynamic configurability through software-controlled WSS devices that can be reconfigured to change routing paths, add/drop wavelengths, and adapt to different network topologies. This dynamic nature allows the system to scale flexibly without requiring physical reconfiguration of large OXC switches.

Inventive Principle:
Principle #15Dynamics

3Reliability

If known MCS based structure or OXC based structure is used, then CDC capabilities are achieved, but restoration speed deteriorates due to limitation to 1:1 protection scheme

Engineering Contradiction:
ImproveCDC capabilitiesVSAvoidrestoration speed
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent implements 1+1 protection by pre-establishing duplicate optical paths for critical super-channels. When a failure occurs, traffic is immediately switched to the pre-configured protection path without requiring complex real-time calculations, achieving rapid restoration comparable to electronic protection schemes.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces a control plane intermediary that manages the coordination between the data plane OXC switches and WSS ROADMs. This intermediary enables rapid failure detection and protection switching by maintaining real-time knowledge of network topology and path status, facilitating fast restoration without sacrificing CDC flexibility.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3503443B1Methods and apparatus for a colorless directionless and super-channel contentionless (CDSC) optical network architecture
Publication Date: 2024.04.17 JUNIPER NETWORKS INC
  • EP3503443B1 patent drawingFigure 1
  • EP3503443B1 patent drawingFigure 2
  • EP3503443B1 patent drawingFigure 3A

AI summary

In some embodiments, a system includes a super-channel multiplexer (SCM) and an optical cross connect (OXC) switch. The SCM is configured to multiplex a set of optical signals into a super-channel optical signal with a wavelength band. The OXC switch is configured to be operatively coupled to the SCM and a reconfigurable optical add-drop multiplexer (ROADM) degree. The OXC switch is configured to be located between the SCM and the ROADM degree and the OXC switch, the SCM, and the ROADM degree are configured to be included in a colorless, directionless, and contentionless (CDC) optical network. The OXC switch is configured to switch, based on the wavelength band, the super-channel optical signal to an output port from a set of output ports of the OXC switch. The OXC switch is configured to transmit the super-channel optical signal from the output port to the ROADM degree.