Submarine Optical Cable Loopback Circuit for Fault Detection

Solution Overview

Problem

The high cost of repairing submarine optical cables necessitates a reduction in the number of components and movable units, making traditional configurations for confirming the used submarine optical cable unreliable.

Innovation Solution

A submarine optical communication system is designed with a first terminal station, a first splitting device, a second splitting device, and a second terminal station, incorporating a loopback mechanism in one of the paths to enable confirmation of the used submarine optical cable without additional communication devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a communication device is provided for an optical switch to confirm the submarine optical cable being used, then the reliability of the submarine optical communication system is improved, but the device complexity and cost increase

Engineering Contradiction:

Improvereliability of submarine optical communication systemVSAvoiddevice complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the cable confirmation function from the optical switch by using a separate loopback means connected to the terminal station. The loopback means includes a splitter that divides the optical signal into two paths: one returning through the submarine optical cable to confirm its status, and another returning through a different path. This separation allows the terminal station to independently monitor cable status without requiring communication devices within the optical switch itself.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The loopback means acts as an intermediary device between the terminal station and the optical switch. It receives the optical signal from the optical switch, splits it into multiple paths, and returns the signals to the terminal station for analysis. This intermediary structure enables cable confirmation functionality without integrating complex communication devices into the optical switch.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a communication device is provided for an optical switch to confirm the submarine optical cable being used, then the reliability of the submarine optical communication system is improved, but the number of components increases

Engineering Contradiction:

Improvereliability of submarine optical communication systemVSAvoidnumber of components

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent extracts the cable confirmation function from the optical switch by using a separate loopback means connected to the terminal station. The loopback means includes a splitter that divides the optical signal into two paths: one returning through the submarine optical cable to confirm its status, and another returning through a different path. This separation allows the terminal station to independently monitor cable status without requiring communication devices within the optical switch itself.

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If redundant configuration of submarine optical cable is used to improve reliability, then the reliability of the submarine optical communication system is improved, but the cost of repair increases

Engineering Contradiction:

Improvereliability of submarine optical communication systemVSAvoidcost of repair

Core Design Contradiction:

ReliabilityVSEase of repair

Solution Approach 1:

The patent implements a feedback mechanism where the terminal station continuously monitors the optical signal returning through the loopback means to detect cable status. When a cable fault occurs, the terminal station receives feedback signals that indicate the fault condition, enabling automatic or rapid manual switching to redundant cables. This feedback system improves reliability by enabling quick detection and response to cable failures without requiring complex repair operations.

Inventive Principle:

Principle #23Feedback

Data Source

PatentUS20250202597A1Submarine optical communication system

Publication Date: 2025.06.19 NEC CORP

AI summary

In order to be able to check a submarine optical cable in use while improving reliability, this submarine optical communication system has a loopback circuit included in a second path, and the loopback circuit includes: a first input port that receives a first optical signal output by a first switch; a splitter that causes the first optical signal input from the first input port to split; a first output port that outputs, to a second switch, one of the first optical signals split by the splitter; and a second output port that outputs, to a first optical receiver, at least a portion of the other of the first optical signals split by the splitter.