Single OTDR Measurement for Multi-Path Fiber Networks
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Solution Overview
Problem
In fiber-optic communication systems, performing OTDR measurements in optical transmission systems with multiple paths is challenging due to the difficulty in determining the origin of reflective events, especially when multiple optical paths share a common branching point, leading to ambiguity in identifying irregularities and requiring additional equipment and time-consuming separate measurements.
Innovation Solution
A method that involves emitting a single OTDR sampling optical signal into multiple optical paths through a common branching point, altering predefined optical properties of the signal or its reflections, and analyzing the detected OTDR reflected signals to distinguish between reflections from different paths based on discrepancies in properties such as pulse shape or wavelength, allowing for the determination of the origin of reflective events without separate measurements for each path.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If separate OTDR measurements are performed for each optical path, then measurement precision is improved, but device complexity increases and productivity decreases
Solution Approach 1:
The patent applies parameter changes by modifying the wavelength of the OTDR sampling optical signal emitted into different optical paths. Specifically, different wavelengths are assigned to different paths (e.g., first wavelength for first path, second wavelength for second path), allowing the detection device to distinguish the origin of reflected signals based on wavelength analysis, thereby achieving precise determination without additional optical switching devices
Solution Approach 2:
The detection device is designed to perform multiple functions: it detects reflected optical signals from multiple different wavelengths simultaneously and determines the origin of each reflective event. This multi-functional capability eliminates the need for separate measurement equipment for each optical path, reducing device complexity while maintaining measurement precision
2Measurement precision
If separate OTDR measurements are performed for each optical path, then measurement precision is improved, but productivity decreases
Solution Approach 1:
The patent merges multiple separate OTDR measurements into a single simultaneous measurement process. By emitting OTDR sampling optical signals at different wavelengths into multiple optical paths at the same time and detecting all reflected signals in one operation, the system achieves the determination accuracy of separate measurements while reducing the number of measurements required from multiple sequential operations to a single concurrent operation
Solution Approach 2:
The use of different wavelengths as a distinguishing parameter enables the system to process multiple optical paths simultaneously without interference. The detection device analyzes the wavelength of each reflected signal to determine its origin, allowing precise measurement of multiple paths in a single operation rather than requiring sequential measurements
3Measurement precision
If additional optical devices are used for separate measurements, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent eliminates the need for additional optical switches and couplers by using wavelength as a distinguishing parameter. The detection device directly analyzes the wavelength of reflected signals to determine their origin, achieving precise measurement without requiring complex optical switching infrastructure or additional coupling devices
Solution Approach 2:
The patent extracts the wavelength information from the reflected optical signals and uses it as the key parameter for determining the origin of reflective events. By focusing on this specific parameter (wavelength) rather than using additional optical devices, the system simplifies the measurement setup while maintaining high determination accuracy
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 simplifies surveillance and maintenance by reducing the number of necessary measurements, lowers equipment costs, and improves accuracy by enabling a single OTDR measurement to determine irregularities in optical transmission systems, without the need for additional optical devices like switches or couplers.
Implementation Method 1
The light source sends an optical pulse into the optical path to be tested, which is then partly reflected back by the fiber itself or by an irregularity on the path, also called a 'reflection event'.
Implementation Method 2
altering a predefined optical property of the OTDR sampling optical signal emitted into the second optical path and/or of a reflection of the OTDR sampling optical signal received from the second optical path
Data Source
AI summary
A first optical path and a second optical path have a common path branching point. An OTDR sampling optical signal is emitted into the first optical path and into the second optical path through the common path branching point. At least one predefined optical property of the OTDR sampling optical signal emitted into the second optical path is altered and/or of a reflection of the OTDR sampling optical signal received from the second optical path is altered. An OTDR reflected optical signal resulting from a reflection of the OTDR sampling optical signal on the first optical path and/or from a reflection on the second optical path is detected. The OTDR reflected optical signal is analyzed to determine, based on the at least one predefined optical property, whether the OTDR reflected optical signal resulted from a reflection on the first optical path and/or on the second optical path.