Modular Optical Line Card with Tunable Lasers and Switches

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Solution Overview

Problem

Current optical line card configurations are expensive and lack modularity, requiring full duplication for protection and being unable to upgrade channel capacity without replacing the entire line card.

Innovation Solution

A modular optical line card design featuring tunable lasers, dual modulation units, optical switches, and circulators, controlled by a processing unit for flexible configuration and protection, enabling enhanced modularity and cost-effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a protection optical line card identical to the first is used, then transmission reliability is improved, but device cost and complexity increase

Engineering Contradiction:
Improvetransmission reliabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The optical line card is divided into functional modules: laser sources, modulators, optical switches, and circulators. Each module can be independently configured or protected, allowing partial redundancy rather than full duplication. The optical switch segments the signal paths, enabling selective activation of protection paths for specific channels.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The optical line card is designed with multi-functional components that can serve both working and protection functions. The same optical switches and circulators are used for both signal routing and protection switching, eliminating the need for separate dedicated protection hardware and reducing overall system complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If a second identical protection optical line card is used, then transmission reliability is improved, but manufacturing cost increases

Engineering Contradiction:
Improvetransmission reliabilityVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The working and protection functions are merged into a single optical line card structure. The optical switches and circulators handle both normal signal transmission and protection switching, consolidating what would traditionally require two separate line cards into one integrated unit, thereby reducing manufacturing costs.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system dynamically reconfigures signal paths through optical switches based on failure detection. Instead of static duplicated hardware, the system uses dynamic switching to activate protection paths only when needed, allowing a single line card to serve dual purposes and reduce manufacturing expenses.

Inventive Principle:
Principle #15Dynamics

3Ease of manufacture

If the optical line card structure is fixed, then manufacturing simplicity is maintained, but adaptability for future upgrades deteriorates

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidadaptability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The optical line card employs modular functional blocks (laser sources, modulators, optical switches, circulators) that can be independently configured. This segmentation allows future upgrades by adding or reconfiguring specific modules without redesigning the entire system, maintaining manufacturing simplicity while enabling adaptability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The optical switches enable dynamic reconfiguration of signal paths, allowing the system to adapt to different channel capacities and traffic patterns. The same physical infrastructure can be reconfigured to handle increased traffic or new service requirements without hardware replacement.

Inventive Principle:
Principle #15Dynamics

4Reliability

If full duplication of optical line card elements is implemented, then protection capability is improved, but device complexity increases

Engineering Contradiction:
Improveprotection capabilityVSAvoiddevice complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Optical circulators act as intermediary components that enable bidirectional signal flow and protection switching without requiring separate dedicated protection paths. The circulators mediate between the working and protection signal paths, allowing a single set of core components to serve both functions and reduce overall system complexity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The optical switches and circulators are designed as universal components that perform both signal routing during normal operation and protection switching during failures. This multi-functionality eliminates the need for separate dedicated protection hardware, reducing device complexity while maintaining comprehensive protection capability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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

The modular design allows for flexible configuration, protection, and capacity upgrades, providing a cost-effective solution with improved modularity and the ability to handle increased channel demands without replacing the entire line card.

Implementation Method 1

a first tunable laser, a second tunable laser

Methodology Applied
Scientific EffectLaser emission: Laser

Implementation Method 2

a first modulator configured for modulating a first signal received on a first input linked to the first output of the first optical switch

Methodology Applied
Scientific EffectOptical modulation: Phase Modulation

Implementation Method 3

a first optical circulator comprising a first input/output port linked to the first output of the dual modulation unit and a second input/output port

Methodology Applied
Scientific EffectOptical circulation: Optical Fibre

Data Source

PatentEP3416316B1Optical line card and transmitter
Publication Date: 2019.09.25 NOKIA SOLUTIONS & NETWORKS OY
  • EP3416316B1 patent drawingFigure 1~2
  • EP3416316B1 patent drawingFigure 3~4
  • EP3416316B1 patent drawingFigure 5~7

AI summary

The present invention refers to an optical line card (10, 10', 10") comprising: - a first tunable laser (12), - a second tunable laser (12'), - a first optical switch (14) comprising a first input (14a) linked to the first tunable laser (12), a second input (14a') linked to the second tunable laser (12'), a first output (14b) which can be linked to the first (14a) or to the second (14a') input, a second output (14b') which can be linked to the first (14a) or to the second (14a') input, - a dual modulation unit (15) comprising: - a first modulator (16) configured for modulating a first signal received on a first input (16a) linked to the first output (14b) of the first optical switch (14), the first modulated signal being transmitted to a first output (16b), - a second modulator (16') configured for modulating a second signal received on a second input (16'a) linked to the second output (14b') of the first optical switch (14), the second modulated signal being transmitted to a second output (16'b), - a first optical circulator (18) comprising a first input/output port (18a) linked to the first output (16b) of the dual modulation unit (15) and a second input/output port (18b), - a second optical circulator (18') comprising a first input/output port (18'a) linked to the second output (16'b) of the dual modulation unit (15) and a second input/output port (18'b), - a second optical switch (20) comprising a first input (20a) linked to the second input/output port (18b) of the first optical circulator (18) and a second input (20a') linked to the second input/output port (18'b) of the second optical circulator (18').