Bi-directional OTDR Fiber Analysis via Dual-Device Data Exchange
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Solution Overview
Problem
Current optical time-domain reflectometer (OTDR) devices face challenges in detecting all optical events along optical fibers, particularly after splitters, due to limited pulse width dynamic range and resolution, which restricts the ability to perform complete bi-directional measurements in optical network deployments.
Innovation Solution
The OTDR device performs bi-directional optical measurements by exchanging results between two OTDR devices connected at opposite ends of the optical fiber, allowing for comprehensive characterization of the fiber, including insertion loss, optical continuous wave reflectometer-optical return loss, and fiber length measurements, using a single connection port to eliminate repetitive disconnection and enhance measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single OTDR device performs unidirectional measurements, then the device complexity is reduced, but the measurement precision and completeness of optical event detection deteriorate
Solution Approach 1:
The measurement process is segmented into two directional components: forward measurements from location A to location B, and reverse measurements from location B to location A. Each OTDR device performs measurements in its respective direction, and the results are segmented and combined to achieve complete bidirectional coverage of all optical events along the fiber.
Solution Approach 2:
The patent merges the results from two separate unidirectional measurements into a single comprehensive bidirectional measurement result. The sensor display generator combines the forward and reverse measurement data, integrating detection results from both directions to provide complete optical event characterization that neither single-direction measurement could achieve alone.
2Measurement precision
If OTDR devices are disconnected and reconnected at both ends of the fiber for complete measurements, then the measurement precision improves, but the loss of time increases
Solution Approach 1:
The system performs preliminary actions by establishing both forward and reverse measurement paths in advance through a single connection. The OTDR devices are pre-configured to communicate and coordinate their measurements through the fiber under test, eliminating the need for subsequent reconnections. The bidirectional measurement framework is set up beforehand, allowing immediate execution of complete measurements.
Solution Approach 2:
The measurement process maintains continuity by keeping both OTDR devices connected throughout the entire measurement sequence. The system continuously exchanges measurement data and coordination signals between the two devices without interruption or disconnection, enabling seamless bidirectional measurements that would otherwise require time-consuming reconnections.
3Reliability
If the pulse width is increased to improve signal strength, then the detection capability improves, but the resolution of optical events deteriorates
Solution Approach 1:
The system applies local quality by using different pulse width parameters for different measurement directions or different segments of the fiber. Each OTDR device can optimize its pulse width setting based on local requirements: using wider pulses for detecting weak signals in low-loss sections and narrower pulses for resolving closely spaced events in high-loss or critical sections.
Solution Approach 2:
The measurement system dynamically adjusts pulse width parameters during the measurement process. The OTDR devices can change pulse width settings between forward and reverse measurements, or adaptively adjust based on detected signal conditions, allowing optimization of both detection capability and resolution for different portions of the fiber under test.
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 enables a complete view of optical events along the fiber, including those after splitters, by averaging attenuation values and determining optical event parameters, thus improving the detection and measurement of faults and features in optical networks.
Implementation Method 1
emit, by a laser source of the OTDR device, a laser beam into a device under test (DUT)
Implementation Method 2
extract light that is scattered or reflected back from points along the optical fiber
Implementation Method 3
extract light that is scattered or reflected back from points along the optical fiber
Data Source
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AI summary
In some examples, an optical time-domain reflectometer (OTDR) device may include a laser source to emit a laser beam into a device under test (DUT), and a connection port to connect the OTDR device to a first end of the DUT, where the OTDR device may be designated a first OTDR device. A sensor display generator may determine a length of the DUT, receive, from a second OTDR device connectable to a second opposite end of the DUT, and over the DUT, OTDR information acquired by the second OTDR device in a direction from the second OTDR device towards the first OTDR device, and ascertain, based on acquisition by the first OTDR device, further OTDR information in a direction from the first OTDR device towards the second OTDR device. The sensor display generator may generate a bi-directional combined schematic display that includes relevant optical events with respect to the DUT.