WO2023004492A1 - Emplacement de panne dans un réseau à fibres optiques - Google Patents

Emplacement de panne dans un réseau à fibres optiques Download PDF

Info

Publication number
WO2023004492A1
WO2023004492A1 PCT/CA2022/050251 CA2022050251W WO2023004492A1 WO 2023004492 A1 WO2023004492 A1 WO 2023004492A1 CA 2022050251 W CA2022050251 W CA 2022050251W WO 2023004492 A1 WO2023004492 A1 WO 2023004492A1
Authority
WO
WIPO (PCT)
Prior art keywords
optical fiber
junctions
gaps
optical
data
Prior art date
Application number
PCT/CA2022/050251
Other languages
English (en)
Inventor
Louis Poulin
Michael Coutinho Fernandes
Nicholaos MIKEDIS
Original Assignee
Atvent Solutions Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from US17/473,152 external-priority patent/US11290179B1/en
Application filed by Atvent Solutions Inc. filed Critical Atvent Solutions Inc.
Publication of WO2023004492A1 publication Critical patent/WO2023004492A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/071—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G01M11/30—Testing of optical devices, constituted by fibre optics or optical waveguides
    • G01M11/31—Testing of optical devices, constituted by fibre optics or optical waveguides with a light emitter and a light receiver being disposed at the same side of a fibre or waveguide end-face, e.g. reflectometers
    • G01M11/3109—Reflectometers detecting the back-scattered light in the time-domain, e.g. OTDR
    • G01M11/3145—Details of the optoelectronics or data analysis
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
    • G06F—ELECTRIC DIGITAL DATA PROCESSING
    • G06F16/00—Information retrieval; Database structures therefor; File system structures therefor
    • G06F16/20—Information retrieval; Database structures therefor; File system structures therefor of structured data, e.g. relational data
    • G06F16/21—Design, administration or maintenance of databases
    • G06F16/215—Improving data quality; Data cleansing, e.g. de-duplication, removing invalid entries or correcting typographical errors

Definitions

  • the present patent application relates to remote location of optical fiber network faults with optical time-domain reflectometer.
  • optical fibers of telecommunication networks are installed over long distances in a branching arrangement with a plurality of segments connected at junctions with couplers, connectors or splices. Installation of these segments is performed by the telecommunications company employees that are not only responsible for laying out the optical fiber (OF) and connecting the various segments together but, in many cases, are also responsible for the data entry of the lengths of these segments in the network database (DB) along with GPS coordinates of locations of junctions. Therefore, in addition to smaller deviations from the real values (gaps), it is not uncommon to see major sporadic database errors made by the employee through data entry error(s) when installing the optical fiber network segments.
  • OF optical fiber
  • DB network database
  • the OF network segment When the OF network segment fails, it may be a partial loss of signal at a junction that reduces data throughput, or it can be a rupture at a junction or anywhere along the cable that prevents further transmission. In either case, a service call is made to find and repair the OF network segment when one of these faults is detected.
  • the optical time-domain reflectometry (OTDR) measurement method is a technique for finding a distribution of losses along an optical fiber by measuring reflected light and backward-scattered light over the length of the OF generated within the OF by an optical pulse that is propagated from one end.
  • OTDR equipment may not see each junction, but only the gradual loss along the line.
  • a junction introduces non-negligible loss, an event appears in the OTDR data as a distinguishable signal loss.
  • the end of the OF segment or a cut of the segment shows as the final loss in the OTDR data.
  • OTDR may not be used to identify every element of an OF span since only significant signal losses can be identified.
  • the optical fiber cable is installed over a long distance such as several kilometers or more, which makes remote monitoring necessary, and the monitoring is performed by remotely finding a state, particularly a distribution of loss, by using the OTDR measurement method.
  • OTDR data provides a distance along the fiber to an event, to find an event location, the maintenance team needs the data recorded from the time of installation about the length of OF between junctions in the corresponding GIS.
  • the process of narrowing down the most likely location to send the maintenance team to locate the source of a signal loss occurrence (fault) site with an OTDR measurement can be laborious and/or costly with the current locating techniques when the GIS data is erroneous.
  • the maintenance or repair team can be at a loss.
  • the applicant has developed a method for locating the source of an abnormality by determining the position of an OTDR signal loss occurrence or event in the optical fiber span when there is an error in the GIS or database (DB) data.
  • the method for identifying a location of a reflection event in an optical fiber span may comprise accessing database data representing lengths of optical fiber segments separated by junctions forming the optical fiber span, accessing optical time-domain reflectometry measurement data of the optical fiber span comprising a plurality of signal loss events fewer than a number of the optical fiber junctions, where the events are corresponding to the junctions.
  • Using the optimal solution to output the correct lengths of segments corrected with the solution s gaps and the position of one or more events.
  • the applicant’s method is particularly efficient and useful when working with a database and GIS comprising one or more considerable erroneous segment lengths values between network elements (junctions) which can often be attributed to data entry error from the installation or maintenance team employees that are susceptible to generate major discrepancies with the actual real lengths.
  • This data entry error for the length of one segment can be significant enough to require a correction gap greater than either this erroneous segment or the following segment.
  • a data entry error in one of the lengths of an optical fiber segment can be adjusted to a position beyond one of the two nearest neighboring junctions.
  • an employee making a database entry typo by interchanging the numbers (290 meters instead of 920 meters, for example) or entering the length for the wrong segment are the most significant errors present in most of the network databases.
  • Some embodiments can investigate/process a plurality of possible alternative spans (up to one for each possible network branch), one after the other, using the previously described method before selecting the span that best matches the OTDR measurement (the span with the smallest total of gaps or best fitness) when the span corresponding to the OTDR trace cannot be confidently identified using a cryptic or incomplete or erroneous database data.
  • the distance between OTDR events and each of the network elements is calculated and these distances are compared for each of the events to try to match at least a pair of them.
  • this distance is used as a first gap to use in the matching optimization step to accelerate the identification of the optimal solution.
  • the optical time-domain reflectometry measurement data comprises a complete loss of signal induced by a cut on one of the optical fiber segments of the span before the termination of the optical fiber span.
  • Some embodiments use the gaps to correct and update the database data.
  • Some embodiments save the gaps as metadata to correct and update the database data values when using the corresponding segments and spans.
  • Some embodiments can display the most likely position of an OF point of abnormality (fault) on a map of the region. Some embodiments can also display the nearby network GIS on that map. [00015] Some embodiments can use various OTDR measurements of alternative network branches comprising at least the span of the event corresponding to the fault, where the various measurements are used to match one or more additional trace events to correct the length of the span comprising the event of interest and/or narrow down the position the fault.
  • a computer program can be used to process and execute the method here described with any device comprising a processor and a readable memory device with access to the data.
  • An optical fiber cable monitoring method and an optical fiber cable monitoring system are able to link information obtained from a measurement result with information stored in a database containing an erroneous entry while still identifying a signal loss event location in an optical fiber cable.
  • the optical fiber cable monitoring method can use an automated algorithm to identify the network element corresponding to the loss event of the optical measurement (OTDR).
  • ODR loss event of the optical measurement
  • the applicant has developed a method for correcting database data of an optical fiber span with an OTDR measurement in the optical fiber span when there is an error in the GIS or DB data.
  • the method for correcting database data of an optical fiber span may comprise accessing database data representing lengths of optical fiber segments separated by junctions forming the optical fiber span, accessing optical time-domain reflectometry measurement data of the optical fiber span comprising a plurality of signal loss events fewer than a number of the optical fiber junctions, where the events are corresponding to the junctions. Completing an initial matching and a matching optimization to find the optimal matching solution with the smallest set of gaps. Using the optimal solution’s set of gaps to correct the lengths of optical fiber segments in the database data or GIS data.
  • Figure 1 is a schematic representation of a faulted optical fiber network with several elements (splices, couplers and loops) connecting an operation center to several branches (AI. .N and B).
  • Figure 2 is a graphic representation illustrating the results of an optical time-domain reflectometry measurement of branch Ai with multiple events of signal loss (I to VII) and the end of the line VIII.
  • Figure 3 is a visual representation of the initial matching process used to compare the OTDR measurement to the GIS of the network branch and extrapolate which of the reflectometry ’ s events can be matched to the nearest junction of the corresponding network.
  • Figure 4 is a visual representation of the optimal solution generated using the matching optimization process and corresponding to the real specifications of the span’s segments length.
  • Figure 5 is a flowchart of the matching algorithm used to complete the initial matching OTDR events with span junctions and the iterative matching optimization for determining the optimal matching arrangement solution.
  • Figure 6 is a block diagram of the main steps of the method that uses erroneous database data, an OTDR measurement and an automated algorithm to correct the database data and to find the location of a source of an abnormality of the span.
  • Figure 7 illustrates a possible result of the method where the most likely position of a fault and its associated optical fiber span connecting a service provider and a service subscriber are displayed on a map to help guide the dispatched maintenance team to rapidly pinpoint the real position.
  • Figure 8 is an example of an actual result of the method that shows a map displaying an optical fiber route and the junctions matched to events, where the loss per junction and cumulative loss are also displayed.
  • Figure 1 presents a schematized embodiment of a telecommunication provider’ s optical fiber network with two principal branches A and B, where a first branch or span A is used to provide multiple subscribers located at the various outputs (Ai to A N ).
  • the network is comprised of various elements (1 to 18) normally present in an optical fiber telecommunication network, such as couplers, loops (extra lengths) and splices joining OF subsegments together, where one of the junctions may be faulty.
  • a faulty element would affect the quality of the signal, thus affecting the service provided to the subscribers connected to the faulty branch, since the quality of the optical fiber network is greatly dependent on the fiber’s integrity.
  • additional various or alternative elements may be included in an OF span.
  • an OTDR apparatus is connected with an initial splice 1 near the network’s input at the provider’s operation center of Figure 1 to measure and record the optical time-domain reflection of the network’ s branch Ai (from splice 1 to the end Ai) comprising fifteen elements (including two couplers and one the end of the optical fiber).
  • the result of this OTDR measurement is illustrated in Figure 2, where the OTDR trace 20 can be used to identify the punctual significant signal losses (vertical axis), referred to as events, and the distance of optical fiber span separating them to the beginning of the span (horizontal axis).
  • the OTDR trace is saved or uploaded in a standard sor file format.
  • eight events (I to VIII) can be identified on the OTDR trace, where one of which is the event of interest corresponding to a major signal loss event VI induced by the faulty splice separated with the reflectometer by eight kilometers of optical fiber.
  • some of the span’s junctions (J) do not provide any measurable or significant signal loss so the events (e) are fewer than the junctions (e ⁇ j).
  • the OTDR trace ends with a complete loss of signal that is induced by a complete cut of one of the optical fiber span’s segments prior to the span termination that may or may not corresponds to a junction, which can be confused with a fiber end reflection when first looking at that OTDR trace (false fiber end reflection).
  • the matching of events is completed in order to identify the correct position of the junction corresponding to the event prior to the false fiber end reflection. Once the optimization of the solution is completed, this event can be used as a reference point to locate and indicate the most likely position of the optical fiber cut.
  • non-negligible signal loss is normally present for a limited number of the network elements (junctions), since the events are only produced by imperfect junctions which are responsible for the signal loss. In other words, there are normally significantly fewer signal loss events than there are network elements since most connections are well done and induce negligible signal loss. Therefore, it is nontrivial to successfully identify the source of signal losses using the erroneous lengths of the database when trying to match the positions of the OTDR events with a few subsets of elements from the GIS of the corresponding branch (span).
  • Figure 3 illustrates the span of the branch Ai generated by arranging, ordering and adding the lengths of the various span’s segments stored in the database used to generate the linear visual representation 30 of the branch Ai of Figure 1 and the corresponding to the OTDR trace 31 of Figure 2. While all fifteen elements (1 to 14 and output) of this embodiment’s branch are illustrated, only eight events (I to VIII) can be distinguished on the OTDR trace 31.
  • Segment 32 illustrates the adjusted positions of splice 14 and the output Ai when considering the correction gap D 14 to adjust the length of the previous segment.
  • the fitness F of the matching solutions is most importantly based on the sum of the absolute value of the difference between the database position of the junctions and the position of their respectively matched event, here referred to as gaps.
  • the equation of F may favor a solution that may require a larger correction gap to reduce the rest of the gaps. For example, a least-squares fitting may not be suitable since it can penalize the use of a single larger gap.
  • the gaps smaller than a selected tolerance to make up for some of the lesser uncertainties may be neglected when calculating the solution fitness. For example, this may avoid considering a gap smaller than the uncertainties of the OTDR event positions due to an inconsistent or imprecise refractive index of the various optical fiber segments of the span.
  • the initial matching presented could probably be considered as the optimal solution, since the matching of the events can be completed with the addition of a single gap D 14 , when in fact the actual optimal matching solution with the best corresponding fitness is obtained with a various matching arrangement.
  • the optimal solution for this example is illustrated at Figure 4, where the correction gap D h corresponding to the actual erroneous length of the database allows to generate the optimal matching solution by using this correction gap D ⁇ to adjust the length of the preceding OF segment to correct the position of the junction 7 and therefore adjusting the position the following junctions.
  • this correction gap D h is identified by the matching optimization algorithm as the optimal solution with the associated best fitness F since correcting the length of the segment preceding the junction 7 allows to better match the following events with the associated junction with smaller corresponding gaps which give the best fitness by minimizing the sum of the absolute value of gaps in the end.
  • Some embodiments comprise an additional matching optimization process able to identify and generate this optimal solution even when the previous solution has a good fitness and seems to be the best.
  • This matching optimization comprises an iterative algorithm that tries matching events with various junctions, even with non neighboring junctions, and evaluates the associated fitness. Once this iterative process is completed, the solution with the best fitness is kept as the optimal solution.
  • the algorithm for the optimization matching process is a modified version of the metaheuristic search method TABU search.
  • the algorithm used in the matching process can be as summarized in the flowchart presented in Figure 5 and comprising the three main steps; the environment setup and data formatting 51 to extract and standardize the format of the relevant data for the following steps, the initial matching 52 for matching events with their closest neighbors, and the matching optimization 53 for generating the best matching arrangement solution.
  • N is the number of possible alternative solutions
  • i E [1, N] is the current iteration indicator and the quality of the solutions is calculated with the following fitness equation F where n is the number of matched events and g e is the gap for matching event e.
  • the distance between a network element (junction) and the OTDR events is calculated for each one of the junctions and these distances are compared for each of them to try to match at least a pair of them.
  • this distance is used as a correction gap to correct the database data of the first junction presenting this gap and to try to achieve initial matching for the junctions and event positions. This correction gap is kept if this initial matching works and other correction gaps may be used if this initial matching fails with this first correction gap.
  • Figure 6 is a block diagram of the main steps of one embodiment of the method for determining the most likely position of a signal loss occurrence (event of interest) in an optical fiber network.
  • Some embodiments require connectivity to the network database 61 compiling previously measured and inputted specifications of the optical fiber network (step 60) and to the OTDR measurement 63 to access the required data. This connectivity is necessary to ensure efficient searching, uploading, sorting and processing the required data, especially in most cases where the database is disorganized, jumbled and/or cryptic in addition to being specific for each provider. Note that the database structure can change with the year of installation of the optical fiber or with the tendered installation company and is significantly different for the inside of buildings.
  • Some embodiments are comprising an additional automated program and/or algorithm (step 51 of Figure 5 and step 64 of Figure 6) used to efficiently generate the span of one or more of possible alternative network branches and also to standardize the format of the data.
  • the following integrated matching process 600 may involve the iterative steps 601, 602, 603 and 604 used to optimize the quality of the match with a minimal correction to the initial database data (minimal total of matching gaps) needed to complete the matching process of most of the OTDR events as previously described.
  • the optimal solution is selected and the associated gaps are used to correct the length of the segments of the span (step 68), display the matched events on a map 69 and correct the database data when allowed or save them as metadata when the database access is limited.
  • Some embodiments can be used to locate the position of an event of interest of an OTDR measurement completed on a network without a specified corresponding branch. This is useful when the specific span of the branch associated with the OTDR measurement cannot be identified within all the possible branches of the database when the data of the connection information between these branch segments are unspecified or erroneous.
  • connection information data specifies which of the optical fiber segment is connected or spliced to which of the other optical fiber segments present at a given junction.
  • the connection information data should specify to which following branch an optical fiber is connected, but in some cases, it is either not found or non-existent (unspecified) and/or inexact (erroneous).
  • some embodiments first generate a span for each of the possible branches, from the OTDR reflectometer position (OTDR input) to the ends of the branches, with the DB data at step 64.
  • the access to the database is limited to the data extraction and does not allow modifying its data for various reasons including information security.
  • the gaps are saved as metadata in the user’s device and/or a dedicated alternative network correction database accessible from any device for using the presented method. These metadata are then used to correct the associated network database data when they are used once more in the same or an alternative case.
  • Figure 7 illustrates an example of a map of an optical fiber route 70 connecting a provider center or central office 71 and a subscriber’s building 72, where the span junctions matched with events are identified with circles 76 and where the most likely position of an event of interest is indicated with a X mark 74.
  • the optical fiber route displayed on the map can be generated with an application or program by combining the geographic information of the branch elements, the correct lengths of the branch segments, a map of the concerned area and the results of the method.
  • the coordinates of the event of interest’s most likely position and alternative possible positions are also displayed.
  • all the junctions matched with an event e are displayed on the map with their distance from a starting point (De), their associated signal loss (SLe) and respective coordinates (Coord. e).
  • the map is an interactive map that can display the possible itineraries to get to a selected location.
  • Figure 8 is an example of an actual optical fiber route 70 connecting a provider center 71 to a subscriber 71 displayed on a map where the events are mapped to junctions (connectors or splices) along the route and where the loss per junction and cumulative loss are displayed.
  • the OTDR measurement can be made at other junctions of the network, not necessarily at one of the branch ends. Therefore, embodiments can be programmed to be installed on a portable device equipped with readable memory, a processor, a display and access to the required data to use an additional OTDR trace by simply identifying the junction and the optical fiber on which the OTDR measurement was taken and the direction of the measurement signal: upstream (toward the provider) or downstream (toward the subscriber). This can allow the fault position to be further narrowed down or pinpointed by the maintenance team while investigating in the field.
  • the OTDR reading of other branches sharing at least the span comprising the event of interest can be used to narrow down the possible location of the fault.
  • one or more additional events may be detected on these new OTDR measurements and used to help increase the identification of associated gaps to better correct the database data, thus better narrowing down the possible position of the fault.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Theoretical Computer Science (AREA)
  • Databases & Information Systems (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Quality & Reliability (AREA)
  • Optics & Photonics (AREA)
  • Data Mining & Analysis (AREA)
  • General Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Electromagnetism (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Testing Of Optical Devices Or Fibers (AREA)

Abstract

Selon l'invention, un procédé de surveillance de câble à fibre optique et un système de surveillance de câble à fibre optique sont capables d'associer des informations obtenues à partir d'un résultat de mesure avec des informations stockées dans une base de données contenant une entrée erronée tout en identifiant quand même un emplacement d'évènement de perte de signal dans un câble à fibre optique. Le procédé de surveillance de câble à fibre optique peut utiliser un algorithme automatisé pour identifier l'élément de réseau correspondant à l'évènement de perte de la mesure optique (OTDR). Ainsi, un opérateur peut reconnaître un emplacement réel d'une panne qui est associée à un emplacement d'un point d'anomalie sur le câble à fibre optique lorsqu'une anomalie dans le réseau est détectée.
PCT/CA2022/050251 2021-07-26 2022-02-22 Emplacement de panne dans un réseau à fibres optiques WO2023004492A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US202163225847P 2021-07-26 2021-07-26
US63/225,847 2021-07-26
US17/473,152 2021-09-13
US17/473,152 US11290179B1 (en) 2021-07-26 2021-09-13 Fault location in an optical fiber network

Publications (1)

Publication Number Publication Date
WO2023004492A1 true WO2023004492A1 (fr) 2023-02-02

Family

ID=82117358

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CA2022/050251 WO2023004492A1 (fr) 2021-07-26 2022-02-22 Emplacement de panne dans un réseau à fibres optiques

Country Status (1)

Country Link
WO (1) WO2023004492A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040047629A1 (en) * 2002-08-20 2004-03-11 Red Sky Systems, Inc. Adaptor arrangement for detecting faults in an optically amplified multi-span transmission system using a remotely located OTDR
US20130286852A1 (en) * 2012-04-27 2013-10-31 General Instrument Corporation Estimating Physical Locations of Network Faults
US20140104599A1 (en) * 2012-10-12 2014-04-17 Electronics And Telecommunications Research Institute Method of improving performance of optical time domain reflectometer (otdr)
US20140133844A1 (en) * 2012-11-14 2014-05-15 Stefan Dahlfort Sequence-based link fault localization
US20180006715A1 (en) * 2015-05-07 2018-01-04 Centre For Development Of Telematics Gis based centralized fiber fault localization system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040047629A1 (en) * 2002-08-20 2004-03-11 Red Sky Systems, Inc. Adaptor arrangement for detecting faults in an optically amplified multi-span transmission system using a remotely located OTDR
US20130286852A1 (en) * 2012-04-27 2013-10-31 General Instrument Corporation Estimating Physical Locations of Network Faults
US20140104599A1 (en) * 2012-10-12 2014-04-17 Electronics And Telecommunications Research Institute Method of improving performance of optical time domain reflectometer (otdr)
US20140133844A1 (en) * 2012-11-14 2014-05-15 Stefan Dahlfort Sequence-based link fault localization
US20180006715A1 (en) * 2015-05-07 2018-01-04 Centre For Development Of Telematics Gis based centralized fiber fault localization system

Similar Documents

Publication Publication Date Title
US11112332B2 (en) Optical fiber monitoring method, and optical fiber monitoring system
CN108696313B (zh) 一种光缆故障精确定位方法
US20210376923A1 (en) Logical to physical link mapping in a fiber optic network
US8570501B2 (en) Fiber identification using mode field diameter profile
CN104378156B (zh) 一种对光缆故障点精确定位的方法
CN104395737A (zh) 用于识别多芯光缆中的光纤顺序的系统和方法
US8095003B2 (en) Fiber optic testing system and method incorporating geolocation information
CN111510205A (zh) 一种基于深度学习的光缆故障定位方法、装置及设备
CN112887017B (zh) 一种光缆接续杆塔的定位方法及定位系统
CN110545140B (zh) 光缆故障点逼近定位方法
CN115021804B (zh) 一种长距离通信光缆故障定位方法及相关装置
CN115882938A (zh) 一种光网故障监测系统
US11290179B1 (en) Fault location in an optical fiber network
WO2023004492A1 (fr) Emplacement de panne dans un réseau à fibres optiques
CN112433126A (zh) 一种基于数字模型的线束安装后故障空间位置快速定位法
CN109217917B (zh) 故障光纤的位置确定方法及装置、存储介质、处理器
JP2003234708A (ja) 下水道光ネットワークシステム
CN113302852B (zh) 光纤路径搜索方法、光纤路径搜索装置和程序
CN114362819A (zh) 一种光缆故障点定位方法、装置、设备及介质
CN113890607B (zh) 光缆t接点定位方法、装置、计算机设备和存储介质
CN115987381B (zh) 一种光纤同缆的检测方法与装置
CN221487722U (zh) 基于光时域反射仪的光缆普查定位系统
CN113411121B (zh) 光通信网络中检测设备布点和光纤纤芯连接联合优化方法
TWI742598B (zh) 行動化查測被動式光網路之系統與方法
US11677462B1 (en) Landmark correlation mechanism

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22731465

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 22731465

Country of ref document: EP

Kind code of ref document: A1