Fiber Identification Without Cut Points Using Distributed Optical Fiber Sensing

Abstract

A system, method and structure are provided to efficiently identify individual fibers located within deployed cables, reducing tedious field work and shortening service outage times. The system and method locate target fibers within a cable without cutting optical fiber ("Cable ID") and identify the target fiber ("Fiber ID") by detecting DFOS signal attention. Two distinct determinations are made: Cable ID and Fiber ID. The DFOS operation detects vibration signals occurring along the sensor fiber. Cable ID is implemented as an iterative, machine learning based algorithm that automatically locates the cable along the path of the sensor fiber. Fiber ID detects signal attenuation by branching and bending groups of fibers to accurately locate target individual fibers within the fiber cable.

Description

[Technical Field]

[0001] This disclosure relates generally to distributed fiber optic sensing (DFOS) systems, methods, and structures, and more particularly to a cut-pointless fiber identification technique utilizing distributed fiber optic sensing. [Background technology]

[0002] To support fifth-generation (5G and beyond) networks, telecommunications carriers and network service providers have deployed millions of miles of fiber optic cable plant. To reduce maintenance costs, deployed telecommunications fiber optic cables often contain dozens or even hundreds of individual fibers that provide redundancy by design. Many of these individual fibers are "dark," meaning they do not currently carry telecommunications traffic but are spare dark fiber for future use.

[0003] Locating and identifying individual fibers within a fiber cable is crucial for telecommunications operators, for example, when individual fibers support new locations or provide new services to existing locations. Often (but not always), fiber layout and fiber color coding depend on prior information and knowledge about the cable's orientation. This information may be obtained from construction maps or from notes or photographs taken manually during construction. When this prior knowledge is lacking or outdated, operators have a difficult time locating and identifying the correct fiber among the dozens, hundreds, or even thousands of fibers within a fiber optic cable, whether for maintenance purposes or to initiate new services. Therefore, locating individual optical fibers within optical cables containing many individual optical fibers is of great industrial importance. Summary of the Invention

[0004] An advancement in the art is provided by aspects of the present disclosure directed to DFOS techniques for efficiently identifying individual fibers located within deployed cables, which advantageously reduces tedious field work while reducing service outage time.

[0005] In contrast to the prior art, the systems and methods of the present invention locate a target fiber within a cable ("cable ID") without cutting the optical fiber and identify the target fiber ("fiber ID") by detecting DFOS signal attention.

[0006] In operation, the target fiber end point is automatically identified using optical power profile analysis technology. The area near the target fiber end point is analyzed to record the target fiber's high reflection peaks, which are then used to set an appropriate threshold. The optical power profile is then continuously measured and compared to the threshold in real time to generate a decision for the specific fiber.

[0007] As shown and described below, the inventive approach includes two aspects: Cable ID and Fiber ID. DFOS operates by detecting vibration signals occurring along the sensor fiber. When implemented, Cable ID is an interactive, machine learning-based algorithm that automatically locates cables along the sensor fiber path. Fiber ID detects signal attenuation by branching and bending groups of fibers, accurately locating targeted individual fibers within a fiber cable.

[0008] A more complete understanding of the present disclosure may be realized by reference to the accompanying drawings. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram illustrating an exemplary DFOS system, according to an embodiment of the present invention.

[0010] [Figure 2(A)]FIG. 2(A) is a schematic diagram illustrating an example problem associated with locating a target optical fiber in a deployed fiber optic cable, according to an embodiment of the present disclosure. [Figure 2(B)] FIG. 2(B) is a schematic diagram illustrating an example problem associated with locating a target optical fiber in a deployed fiber optic cable, according to an embodiment of the present disclosure.

[0011] [Figure 3] FIG. 3 is a schematic diagram illustrating the operation of an exemplary architecture of the method of the present invention, according to an embodiment of the present disclosure.

[0012] [Figure 4] FIG. 4 is a schematic diagram illustrating an exemplary operational procedure according to an embodiment of the present disclosure.

[0013] [Figure 5] FIG. 5 is a schematic flow diagram illustrating the operation of a cable vibration on detector, according to an embodiment of the present disclosure.

[0014] [Figure 6] FIG. 6 is a schematic flow diagram illustrating the operation of a cable vibration off detector according to an embodiment of the present disclosure.

[0015] [Figure 7] FIG. 7 is a schematic flow diagram illustrating the operation of a window position finder according to an aspect of the present disclosure.

[0016] [Figure 8] FIG. 8 is a schematic diagram illustrating an exemplary experimental setup according to an embodiment of the present disclosure.

[0017] [Figure 9] FIG. 9 is a schematic flow diagram illustrating the overall operation according to an embodiment of the present disclosure.

[0018] [Figure 10]FIG. 10 is a schematic flow diagram illustrating fiber identification by DFOS (DAS / DVS), according to an embodiment of the present disclosure.

[0019] [Figure 11] FIG. 11 is a schematic diagram illustrating an example problem associated with cable cut restoration, according to an embodiment of the present disclosure.

[0020] [Figure 12] FIG. 12 is a schematic diagram illustrating an exemplary system layout according to an aspect of the present disclosure.

[0021] [Figure 13] FIG. 13 is a schematic diagram illustrating an exemplary V-groove clip, according to an embodiment of the present disclosure.

[0022] [Figure 14] FIG. 14 is a schematic flow diagram illustrating the overall operation according to an embodiment of the present disclosure.

[0023] [Figure 15] FIG. 15 is a schematic flow diagram illustrating an overall fiber pigtail finder with DFOS (DAS / DVS), according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0024] The following merely illustrates the principles of the present disclosure, and it should thus be understood that those skilled in the art will be able to devise various arrangements which embody the principles of the present disclosure, even though not explicitly described or shown herein, and which are within the spirit and scope of the present disclosure.

[0025] Furthermore, all examples and conditional language provided herein are meant to be for educational purposes only to aid in understanding the principles of the present disclosure and concepts provided by the inventors to further the present technology, and should not be construed as being limited to the specifically listed examples and conditions.

[0026] Moreover, all statements herein reciting principles, aspects, and embodiments of the present disclosure, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Furthermore, such equivalents are intended to include both currently known equivalents as well as equivalents developed in the future, i.e., elements developed that perform the same function, regardless of structure.

[0027] Thus, for example, it will be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative circuitry embodying the principles of the disclosure.

[0028] Unless otherwise specified, the drawings herein, including the figures, are not drawn to scale.

[0029] As additional background, we first note that distributed fiber optic sensing (DFOS) is an important and widely used technology for detecting environmental conditions (temperature, vibration, acoustic excitation, strain levels, etc.) anywhere along a fiber optic cable connected to an interrogator. As is well known, modern interrogators are systems that generate an input signal to the fiber and detect and analyze the reflected / scattered signal that is subsequently received. The signal is analyzed to generate an output that is indicative of the environmental conditions occurring along the fiber. The received signal can result from reflections within the fiber, such as Raman backscattering, Rayleigh backscattering, or Brillouin backscattering. DFOS can also use forward signals that exploit the velocity differences of multiple modes. Without loss of generality, the following description assumes a reflected signal, but the same approach can be applied to forward signals.

[0030] Figure 1 is a schematic diagram of a generalized conventional DFOS system. As understood, a modern DFOS system includes an interrogator that periodically generates an optical pulse (or any coded signal) and launches it into an optical fiber. The launched optical pulse signal is transmitted along the optical fiber.

[0031] At locations along the fiber, a small portion of the signal is reflected back to the interrogator. The reflected signal carries information that the interrogator uses for detection, such as changes in power level indicative of physical vibrations. As will be understood and appreciated, the interrogator can include a coded DFOS system, which can employ coherent receiver configurations known in the art.

[0032] The reflected signal is converted to the electrical domain and processed by an interrogator. Based on the time the pulse arrived and the time the signal was detected, the interrogator can determine from which location in the fiber the signal is coming and sense activity at each location in the fiber.

[0033] Those skilled in the art will understand and appreciate that implementing signal coding on the interrogation signal can advantageously improve the signal-to-noise ratio (SNR) of Rayleigh scattering-based systems (e.g., distributed acoustic sensing, or DAS) and Brillouin scattering-based systems (e.g., Brillouin optical time-domain reflectometry, or BOTDR) by allowing more optical power to be transmitted into the fiber.

[0034] As currently implemented in many modern implementations, DFOS systems in fiber optic cables are allocated dedicated fibers and are physically separated from existing optical communication signals carried in different fibers. However, given the exponential growth in bandwidth demand, it is becoming increasingly difficult to economically operate and maintain optical fiber solely for DFOS operations. As a result, there is growing interest in integrating communication and sensing systems onto a common fiber that is part of a larger multi-fiber cable.

[0035] In terms of operation, the DFOS system envisions Rayleigh scattering-based systems (e.g., distributed acoustic sensing or DAS) and Brillouin scattering-based systems (e.g., Brillouin optical time-domain reflectometry or BOTDR) that include coding implementations. Such coding designs make these systems more likely to be integrated with fiber communication systems, as they operate at lower power and are more sensitive to the response time of optical amplifiers.

[0036] Advantageously, DFOS operation can also be integrated with a communication channel via WDM in the same fiber. Within the sensing fiber, the interrogation sequence and the returned sensing signal are optically amplified using either a discrete (EDFA / SOA) or distributed (Raman) method. The returned sensing signal is then amplified and processed with an optical bandpass filter before being sent to a coherent receiver. The coherent receiver detects the optical field in both polarizations of the signal and downconverts it to four baseband lanes for analog-to-digital conversion (ADC) sampling and digital signal processor (DSP) processing. As those skilled in the art will readily understand and appreciate, the decoding operation is performed in the DSP to generate the Rayleigh or Brillouin response of the fiber, and changes in the response are identified and considered as sensor readings.

[0037] In such a configuration, since the coded interrogation sequence is digitally generated, the out-of-band signal is also digitally generated and then combined with the code sequence before the waveform is created by the DAC. When digitally generated together, the out-of-band signal is generated only outside the period of the code sequence, so when added together, the combined waveform has a constant amplitude.

[0038] As those skilled in the art will understand and appreciate, DFOS / DAS / DVS systems have been shown to be capable of detecting, recording and listening to acoustic vibrations in the audible frequency range.

[0039] As noted above, the system of the present invention includes at least two inventive aspects: cable ID and fiber ID.

[0040] Cable ID.

[0041] Cable ID identifies target cables using artificial intelligence (AI) technology to distinguish cable vibration / sway events from other strong vibration signals experienced in the field (which may include overhead cable areas susceptible to wind) and buried cable vibrations caused by road traffic and construction activities. This cable identification involves quickly classifying buried and overhead areas. Prerequisites include human-machine input / interaction to unambiguously confirm target signals in real time, and a specially designed cable vibration-on detector that tolerates the vibration habits and response time variations of various technicians / operators. Further prerequisites include a specially designed cable vibration-off detector that uses an extended kernel to bridge scattered vibration points caused by the different sensitivities of adjacent sensing points, eliminating the effects of surrounding traffic. Because the length of slack cable can vary from location to location, a window locator can detect the location and extent of a cable vibration event, even if the length of the coil present in a manhole or handhole is unknown. The identified window is then used for fiber ID.

[0042] Fiber ID.

[0043] After locating the target cable by cable ID, the method of the present invention analyzes the power profile of sensor fibers located near the identified cable location to further identify fibers of particular interest. Features of the present invention include modifying the sensor to generate the power profile, establishing buffer and monitor regions from the identified cable location and recording pre-termination power levels in the monitor regions, continuously monitoring the average power in the monitor region and comparing it with the pre-termination power level to automatically determine whether the fiber under test is the correct fiber, etc.

[0044] Real-time detection, interaction, and feedback.

[0045] The real-time interactive operation of the method of the present invention provides timely guidance to technicians in the field.

[0046] 2(A) and 2(B) are schematic diagrams illustrating an example problem associated with locating a target optical fiber in a deployed fiber optic cable, according to aspects of the present disclosure.

[0047] Referring to these figures, in FIG. 2(A), a deployed telecommunications optical fiber cable includes F1 fiber (main fiber cable from a central office) and F2 fiber (drop fiber from an FDH (fiber distribution hub)). As will be appreciated by those skilled in the art, there are hundreds / thousands of individual optical fibers in an F1 fiber cable, and tens / hundreds of individual optical fibers in an F2 fiber cable. When a telecommunications carrier / service provider receives a request for a new service, it needs to splice (jump) the optical fiber from the nearest splice point and connect to the community of the new service, as shown in FIG. 2(B). As will be further appreciated by those skilled in the art, such an operation is difficult and time-consuming in that it is necessary to find individual target optical fibers for the new splice.

[0048] FIG. 3 is a schematic diagram illustrating the operation of an exemplary architecture of the inventive method, according to an embodiment of the present invention.

[0049] Referring to this figure, a distributed fiber optic sensing system (DFOS) (101), which may be distributed acoustic sensing (DAS) and / or distributed vibration sensing (DVS), is shown installed in a central control office (CO) / local terminal (100) for real-time, long-term remote monitoring of the entire cable route. The DFOS system is connected to an optical sensor fiber in the field to provide sensing capabilities along the sensor fiber. Advantageously, the optical fiber used for sensing may be dark optical fiber or operational optical fiber supporting telecommunications services provided by one or more service providers.

[0050] When a request for a new service is received, the following steps are performed:

[0051] Step 1: Connect the fiber to the DFOS system.

[0052] A field technician connects the dark fiber or target fiber (fiber connecting to a new community) (202) in the fiber cable to the DFOS system.

[0053] Take your mobile device to the field.

[0054] The technician goes to the nearest junction point / connection box (301) with a mobile device (305) that receives signal analysis results in real time from the DFOS system (101 / 102), for example, via 4G / 5G signals or WiFi.

[0055] Identifies the location of the cable in the field (cable ID).

[0056] To locate a cable in the field, a technician vibrates the fiber cable (201). The DFOS system, combined with human (operator) input, determines the optimal location result and reduces false alarms.

[0057] The exemplary system can have two status states: idle and active. When the system is idle (the default), an unsupervised machine learning algorithm runs to determine which sections of optical fiber are buried. This is important because overhead cable sections often have strong vibration signals that can lead to false alarms. During testing, the operator actively switches fiber ports to find the target cable, so it is important that the system quickly learns the characteristics of the DAS connection path. When the operator arrives in the field, the algorithm has already gathered enough evidence to determine which sections of cable are buried. A binary vector is returned as the result.

[0058] FIG. 4 is a schematic diagram illustrating an exemplary operational procedure according to an embodiment of the present disclosure.

[0059] Once the operator is ready to perform the test (e.g., by opening a manhole / handhole), the system status changes to active, and the operator vibrates the cable according to instructions provided by the software. This is designed to be an interactive process between man and machine to distinguish it from other strong vibration signals in the field. First, the operator is asked to vibrate the cable twice during a specific period and stop in between. The software then scans the entire fiber optic cable path, searching for cable vibration signals along the entire path for all three periods, and returns three binary vectors for the three tests. The correct cable location must pass all three tests and be determined as a buried area. In the rare event that ambiguity still remains, the system has the option to prompt the operator to perform further on / off tests until a single location is found.

[0060] FIG. 5 is a schematic flow diagram illustrating the operation of a cable vibration on detector, in accordance with an embodiment of the present invention.

[0061] FIG. 6 is a schematic flow diagram illustrating the operation of a cable vibration off detector, in accordance with an embodiment of the present invention.

[0062] Cable vibration events typically repeatedly generate the strongest vibration signals at the same location in the buried area, allowing for the establishment of intensity and occurrence thresholds. However, due to the non-uniform material composition of the fiber and the geometry of the cable coil, the response at each location is different. As a result, strong vibration patterns in the sensed vibration matrix may become sporadic and discrete. To solve this problem, a dilation kernel is applied to the initial binary detection results.

[0063] FIG. 7 is a schematic flow diagram illustrating the operation of the window position finder according to an embodiment of the present invention. As illustrated in FIG. 7, the software reports a window as the cable position, covering a set of consecutively detected positions. Since the length of slack fiber in each manhole / handhole is different, the influence range of cable vibrations is also different. This module is based on applying a probabilistic progressive Hough transform to a 1D vector and combines individual detection results at several cable positions into one window based on the continuity of the binary pattern. The center and width of the detection window correspond to the cable position and coil length.

[0064] Identify the location of the target fiber (fiber ID).

[0065] After locating the cable, the system switches to Fiber ID mode. The technician needs to terminate the fiber in the connection box using a pen (303) or his finger (304). The technician can terminate the fiber in groups, narrowing down the candidate groups and target fiber until the mobile device (305) provides a fiber discovery answer.

[0066] At this point a series of steps are performed: First, the sensor settings are changed to output a power profile.

[0067] Next, a buffer region is set from the previously determined and identified cable position, since the cable vibrated during the "Cable ID" step is likely not exactly at the same position (although it may be close) as the connection case.

[0068] After the buffer area, a monitor area is set up, and the average power level of this area is recorded as the "pre-termination level."

[0069] The technician is instructed to terminate fibers one by one or in groups. At the same time, the average power level in the "monitoring area" is continuously monitored. If it is below a certain percentage (e.g., 20%) of the "pre-termination level," it means that this terminated fiber or fiber group is the correct fiber and has been identified. Otherwise, it means that the terminated fiber or fiber group is not the correct one, and the technician can move on to another fiber or fiber group until the correct fiber or fiber group is identified.

[0070] Connecting new fiber to new communities and providing services.

[0071] Once the target fiber is identified, a technician can cut the fiber and connect it to the new community to provide service.

[0072] Experiments were conducted in the laboratory. Figure 8 is a schematic diagram illustrating an exemplary experimental setup according to an embodiment of the present disclosure. Two 1 km fiber spools were used. There were four fibers in the fiber spool. To terminate each fiber, the fiber jacket was pulled out for testing. Several scenarios were simulated: (1) no termination, (2) a weak (lose) termination, and (3) a good termination.

[0073] Scenario 1, no termination.

[0074] When the test fiber is unterminated, the signal received by the DAS shows continuous signal strength along the fiber.

[0075] Scenario 2, weak termination.

[0076] When a weak termination is applied to the test fiber, the signal received by the DAS will show a drop in signal strength at the termination location.

[0077] Scenario 3, good termination.

[0078] If the test fiber has proper termination applied, the signal received by the DAS will have a reduced noise level.

[0079] FIG. 9 is a schematic flow diagram illustrating the overall operation according to an embodiment of the present disclosure.

[0080] FIG. 10 is a schematic flow diagram illustrating fiber identification by DFOS (DAS / DVS), according to an embodiment of the present disclosure.

[0081] To further illustrate the application of the DFOS fiber location technology of the present invention, it is important to remember that there are millions of miles of optical fiber installed worldwide. Typically, optical fibers are spliced ​​and cascaded to reach their destination. However, because a single fiber cable contains tens, hundreds, or even thousands of fibers, it is important to locate the desired pigtail within the fiber cable when the fiber cable is cut. Although fibers may be color-coded, the color may fade after several years (e.g., 20 years) of installation. In some cases, field technicians may need to spend hours locating a single pigtail to repair a fiber cut. Therefore, locating a fiber pigtail within an optical cable is crucial for fiber owners to efficiently maintain their installations.

[0082] Existing methods for locating fiber pigtails in optical cables involve shining a red light into one end of the cable and detecting the signal at the break point. However, this method is distance-limited by signal transmission losses within the fiber. This method does not work well if the break is far from the central office.

[0083] Another method is to directly splice the fiber and measure the fiber length using an OTDR, but this is a time-consuming and inefficient process.

[0084] Here, we disclose a method for locating fiber optic pigtails in deployed fiber optic cables as an efficient way to reduce tedious field work. We employ a distributed fiber optic sensing (DFOS) system to generate results in real time.

[0085] As described herein, the method of the present invention utilizes DFOS to detect signals from an open end of an optical fiber. When a fiber optic cable is cut, the reflected signal is larger than when the fiber optic cable is uncut due to approximately 4% reflection from air. In this case, the enhanced reflection affects sensing detection at the end of the fiber.

[0086] As those skilled in the art will understand and appreciate, locating a fiber pigtail disposed within a fiber optic cable presents several challenges.

[0087] Cable cut point detection.

[0088] To identify the signal, an end point localization AI method is used to identify the location of the fiber end (fiber cut location).

[0089] Reduced reflected signal from fiber cut points.

[0090] Since large reflections from the open end of an optical fiber affect the sensitivity of DFOS, it is necessary to reduce signal reflections. One way to achieve this is to terminate the optical fiber.

[0091] Signal generation at the endpoints.

[0092] To ensure that the pigtail is the target fiber, a vibration source with a designed frequency pattern is used at the end of the fiber. If the DFOS detects the same frequency pattern, the fiber pigtail is the target fiber.

[0093] Real-time detection and feedback.

[0094] A remote mobile device is employed to provide real-time feedback to identify fiber pigtails for deployed fibers in the field.

[0095] FIG. 11 is a schematic diagram illustrating an exemplary problem associated with cable cut restoration, according to an embodiment of the present invention.

[0096] As discussed above, and as those skilled in the art will understand and appreciate, fiber optic cables typically contain tens, hundreds, or even thousands of individual optical fibers. When a cable cut occurs, it can be difficult to quickly locate the specific fiber pigtail that needs repair. In many cases, it is impossible for a field technician to quickly repair the entire fiber at the fiber cut point. This is because splicing individual optical fibers is a time-consuming and tedious task, especially in field situations. Typically, technicians attempt to repair a cut fiber depending on the customer's urgency. In these situations, quickly identifying the specific fiber pigtail is crucial.

[0097] FIG. 12 is a schematic diagram illustrating an exemplary system layout and exploded view of a V-groove clip, according to an embodiment of the present disclosure.

[0098] FIG. 13 is a schematic diagram illustrating an exemplary V-groove clip, according to an embodiment of the present invention.

[0099] A distributed fiber optic sensing system (DFOS) (101) capable of distributed acoustic sensing (DAS) and / or distributed vibration sensing (DVS) is installed in the central control office (CO) / central office to remotely monitor the entire cable route. To ensure two directions for locating the fiber pigtail, the DFOS (101) may be located in the W-side CO (100) and later moved to the E-side CO (101), or two COs may contain two DFOS systems. The DFOS system is connected to optical fiber in the field to provide sensing capabilities. The fiber can be dark fiber or a service provider's operational fiber.

[0100] When a cable disconnection event occurs, the following steps occur:

[0101] Connect the fiber from the W site CO to the DFOS system.

[0102] A field technician connects a dark fiber or a target fiber (203) in a fiber cable (201) (where the fiber needs to be repaired urgently due to an urgent customer need) from the W-site CO (100) to the DFOS system.

[0103] Connect the fiber from the E-site CO to the DFOS system.

[0104] If two DFOS systems are available, the technician connects the fiber from the E-site CO (101). If only one DFOS system is available, the technician performs the following three steps to move the DFOS system to the E-site CO:

[0105] Take your mobile device to the field.

[0106] A technician carrying a mobile device (301) that communicates with the DFOS system (102 / 103) via 4G / 5G signals and receives real-time signal analysis results is dispatched to the cable cut site (300).

[0107] Clip the fiber and find the desired fiber pigtail.

[0108] When the V-groove clip is used to clip the fiber pigtail, the V-groove induces fiber loss and results in signal termination. Thus, the reflected signal is reduced, and the DFOS system transmits the result to the mobile device. If the fiber pigtail to be tested is not the target fiber pigtail (connected to the DFOS system), change to another fiber pigtail until the target fiber pigtail is identified.

[0109] It can be seen that the reflected / scattered signal is significantly reduced after clipping with the V-groove clip. In most cases, this step can identify the target cable. However, further testing may be done to confirm that the cut pigtail is the target one.

[0110] vibration source.

[0111] After finding the target fiber pigtail (204, 205), the technician turns on the vibration source (302) to generate a design pattern, which can be a special frequency tone, a time sequence pattern, or an intensity sequence signal. This procedure ensures that the fiber pigtail is the target for repair.

[0112] Repair the fiber. After finding the target fiber pigtail (204, 205), the technician can splice / repair the fiber to reduce the service outage period.

[0113] FIG. 14 is a schematic flow diagram illustrating the overall operation according to an embodiment of the present invention.

[0114] FIG. 15 is a schematic flow diagram illustrating an overall fiber pigtail finder with DFOS (DAS / DVS), according to an embodiment of the present invention.

[0115] While the present disclosure has been illustrated herein using certain specific examples, those skilled in the art will recognize that the present teachings are not limited thereto. Accordingly, the present disclosure should be limited only by the scope of the claims appended hereto.

Claims

1. 1. A method for determining fiber identity utilizing distributed fiber optic sensing (DFOS), comprising: (a) an optical sensor fiber that is an individual fiber among a plurality of optical fibers in a fiber optic cable; a DFOS / DVS interrogator in optical communication with the optical sensor fiber, configured to generate optical pulses, input the generated pulses into the optical sensor fiber, and receive backscattered signals from the optical sensor fiber; an intelligent analyzer configured to analyze the DFOS / DVS data received by the DFOS / DVS interrogator and identify vibration activity occurring at locations along the optical sensor fiber from the backscattered signals; a first distributed fiber optic sensing / distributed vibration sensing (DFOS / DVS) system including: (b) operating the first DFOS / DVS system; (c) separating the plurality of optical fibers in the optical fiber cable into groups of separate optical fibers at a field location; (d) physically vibrating the groups of distinct optical fibers one by one in the field until the first DFOS / DVS system indicates a candidate group containing the optical sensor fiber; (e) physically vibrating each individual optical fiber in the candidate group one by one until the optical sensor fiber is pointed to by the first DFOS / DVS system; (f) identifying the indicated optical sensor fiber.

2. The method of claim 1 , wherein the field location is a manhole.

3. The method of claim 1 , further comprising splicing the indicated optical sensor fiber to a new fiber.

4. The method of claim 1 , further comprising terminating the distinct groups one by one with a person's fingers.

5. 2. The method of claim 1, wherein when one or more of the plurality of optical fibers in the fiber optic cable break, vibration clips are attached to the broken ends of the optical fibers one by one until the light sensor fiber is pointed to by the first DFOS / DVS system.

6. The method of claim 5 , wherein the vibrating clip vibrates in a predetermined vibration pattern.

7. The method of claim 5 further comprising a second DFOS / DVS system at a distal end of the fiber optic cable.

8. 8. The method of claim 7, wherein the first DFOS / DVS system provides information indicative of the optical sensor fiber to a handheld mobile device via digital wireless communication.

9. The method of claim 8 , wherein the vibration clip includes a plurality of V-grooves that impart a plurality of physical bends to the optical fiber before vibration is applied.

10. 10. The method of claim 9, wherein the indicative information provided by the first DFOS / DVS system is determined by an artificial intelligence engine included as part of the intelligent analyzer.

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