CN203301485U - PON (Passive Optical Network) line fault monitoring device based on optical mark method - Google Patents

PON (Passive Optical Network) line fault monitoring device based on optical mark method Download PDF

Info

Publication number
CN203301485U
CN203301485U CN2013203268018U CN201320326801U CN203301485U CN 203301485 U CN203301485 U CN 203301485U CN 2013203268018 U CN2013203268018 U CN 2013203268018U CN 201320326801 U CN201320326801 U CN 201320326801U CN 203301485 U CN203301485 U CN 203301485U
Authority
CN
China
Prior art keywords
optical
monitoring
fiber
output
port
Prior art date
Legal status (The legal status 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 status listed.)
Withdrawn - After Issue
Application number
CN2013203268018U
Other languages
Chinese (zh)
Inventor
李传起
王大迟
胡金林
陈艳
杨梦婕
陈美娟
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Guangxi Normal University
Original Assignee
Guangxi Normal University
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
Application filed by Guangxi Normal University filed Critical Guangxi Normal University
Priority to CN2013203268018U priority Critical patent/CN203301485U/en
Application granted granted Critical
Publication of CN203301485U publication Critical patent/CN203301485U/en
Withdrawn - After Issue legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Abstract

The utility model discloses a PON (Passive Optical Network) line fault monitoring device based on optical mark method. The device comprises a monitoring system, a wavelength selector, a 1:2 optical fiber coupler, a 1:N optical splitter and N fiber bragg gratings. The distances from the serially connected fiber bragg gratings on optical fiber branches to the optical splitter are different, the transmission times of a narrow band monitoring pulse sent by a laser source to the optical fiber branches are different, and the monitoring pulses on the optical fiber branches are sequentially arranged on time domain. The monitoring pulses arriving at the branches are marked on the time domain to distinguish different line feedback signals, thereby being called as the optical mark method. An upper computer compares the received monitoring pulse data with original data and judges the on/off conditions of the corresponding branches through the existence of specific pulses. The PON line fault monitoring device disclosed by the utility model overcomes the difficulty that OTDR (Optical Time Domain Reflectometry) cannot support multi-branch network monitoring, is a simple and easy real-time monitoring method of optical network lines with large branching ratios, and has the advantages of high precision and convenience for operation.

Description

PON line fault monitoring device based on the optical markings method
Technical field
The utility model belongs to technical field of optical fiber communication, is specifically related to a kind of line fault of PON based on optical markings method monitoring device.
Background technology
" light entering and copper back " is the inexorable trend of broadband access technology development.Along with PON(Passive Optical Network, passive optical-fiber network) expansion of coverage, the Real-Time Monitoring of its line fault is become to particularly important.It is many that PON has circuit branch, complex structure and be vulnerable to the characteristics of user's geographical distribution impact, and these have increased the complexity of its line upkeep and management.The splitting ratio of PON technology of future generation will reach 1:128, in the urgent need to the automatic monitoring scheme of photosphere of the large splitting ratio network of a kind of effective support.Optical-fiber line fault accounts for very large proportion in all kinds of transmission faults, line fault has stronger sudden and uncertain.The substance of optical-fiber line fault monitoring is to find fault location.The main difficulty that the PON path monitoring faces is the branch road under failure judgement how.Along with OTDR(Optical Time Domain Reflectometer, optical time domain reflectometer) application of technology is ripe and extensively, the research of many equipment vendors is based on the centralized monitoring method of the PON of OTDR.OTDR first, to utilizing emitted light pulse signal in optical fiber, reflects and backscatter signals by receiving and analyzing, can measuring optical fiber length, the parameter such as line loss, and can position fault.This class scheme is used the outer wavelength of band as test light, at OLT(Optical Line Terminal, optical line terminal) and ONU(Optical Network Unit, optical network unit) in add wavelength selector, with the interference of elimination test light to Communication ray.But in point-to-multipoint optical-fiber network (as PON), CO(central office) reflection and backscatter signals that the OTDR in traces into are the stacks of all branched line signal powers, and this has increased the difficulty of line fault location.In addition, OTDR is in the monitoring of PON, and the difficulty that mainly faces is that in the PON system, tie point is more concentrated, must adopt high-resolution and the little OTDR in blind area could distinguish a plurality of loss events, and the optical branching device insertion loss in system is higher, has shortened the measuring range of OTDR; Therefore, for the optical-fiber network of large splitting ratio, OTDR can not provide accurate light line fault information.
For this reason, publication number is CN1980094A disclosed " a kind of arrangement for detecting of optical fiber circuit broken string of passive optical network PON system ", at first this device arranges the fiber grating of different reflection wavelengths on each optical fiber circuit, the detecting data that optical fiber circuit is reflected back has different reflection wavelengths; Then by light power meter, receive simultaneously the detecting data that returns of each loopback fiber, and utilize fiber grating pair detected light wave reflection luminous intensity, judge whether optical fiber circuit breaks and whether the optical fiber circuit loss is excessive, with clear and definite PON system, whether goes wrong.Although this device also can be realized the optical fiber circuit broken string of passive optical network PON system is detected, in the situation that the optical fiber branch road is more, lays the fiber grating of different reflection wavelengths, this can limit the user capacity of passive optical network PON system.In addition, this monitoring mode relies on the certainty of measurement of light power meter and the wave-length coverage of measurement, performance requirement to light power meter is higher, therefore if will allow the light power meter of function singleness can be in so complicated signal, the corresponding Monitoring Data that extracts each optical fiber circuit be difficult.This programme can be along with the increase of optical fiber circuit in the passive optical network PON system, and its precision and operability reduce gradually.
The utility model content
Technical problem to be solved in the utility model is to provide a kind of line fault of PON based on optical markings method monitoring device, and it has precision height and easy to operate characteristics.
For addressing the above problem, the utility model is achieved through the following technical solutions:
Based on the PON line fault monitoring device of optical markings method, comprise monitoring system, wavelength selector, 1:2 fiber coupler, 1:N optical branching device and N fiber grating, wherein the number of N is identical with the number of the optical network unit of required monitoring;
The input/output port of above-mentioned monitoring system shares an interface, and it mainly is comprised of LASER Light Source, fiber amplifier, optical circulator, photoelectric detector, data acquisition system and host computer; The output of LASER Light Source connects the first port of optical circulator through fiber amplifier, the second port of optical circulator is connected with the first port of wavelength selector, and the 3rd port of optical circulator is connected to the input port of photoelectric detector; The output of photoelectric detector is connected with the input of data acquisition system, and the output of data acquisition system is connected to host computer;
Optical line terminal is connected on first minute terminal of 1:2 fiber coupler, the second port of wavelength selector is connected on second minute terminal of 1:2 fiber coupler, and the terminal of closing of 1:2 fiber coupler is connected with the terminal of closing of 1:N optical branching device through an optical fiber main line; The N of a 1:N optical branching device output is connected with an optical network unit through an optical fiber branch road respectively;
N fiber grating is serially connected in respectively the optical network unit front end on N bar optical fiber branch road, and N fiber grating is different apart from the distance of 1:N optical branching device, the fiber grating on the adjacent fiber branch road is satisfied to the range difference Δ L of 1:N optical branching device:
ΔL ≥ T × C 2 × n eff
In formula: T-pulse signal duration; The propagation velocity of C-light; n effThe effective refractive index of-optical fiber.
In said apparatus, the span of described N is between 2~128.
In said apparatus, described LASER Light Source is the laser of narrowband light source.
In said apparatus, described data acquisition system is mainly by analog to digital converter, and data storage and programmable logic device form; The output of programmable logic device is connection mode number converter and data storage respectively, the input of analog to digital converter is connected with the output of photoelectric detector, the output of analog to digital converter is connected with the input of data storage, and the output of data storage is connected with the input of host computer.
In said apparatus, the reflection wavelength of described each fiber grating is all identical by wavelength with the permission of wavelength selector.
Principle of the present utility model is: the fiber grating that is connected in series on each optical fiber branch road is different to the distance of optical branching device, from the asynchronism(-nization) that the arrowband monitoring pulse that LASER Light Source sends is transmitted at each optical fiber branch road, the monitoring pulse on each optical fiber branch road will be arranged in order on time domain.Due to the monitoring pulse to arriving each branch road in the enterprising row labels of time domain, to distinguish different circuit feedback signals, therefore be called the optical markings method.On host computer, the monitoring pulse data that receives can contrast with initial data, the break-make situation that judges respective branch by having or not of certain pulses.The utility model has effectively overcome the difficulty that OTDR is difficult to support the multiple-limb network monitoring, is a kind of simple large shunt is than optical network line method for real-time monitoring.
Compared with prior art, the utlity model has following advantage:
1, the light pulse sequence that reflects by analysis of the utility model judges the situation of each branch road, adopts different Threshold Analysis feedback signals, can in time find in circuit gradual deterioratedly, ensures that proper communication is unaffected.
2, the monitoring pulse wavelength that adopts of the utility model is that ((850nm~1550nm) different, so in observation process, monitor signal can not produce any impact to optical communication system to the U wave band from optical communication wave band used at present for 1625nm~1675nm).
3, in the utility model, very little through the monitoring pulse loss of fiber grating reflection; Fiber grating is different to the distance of optical branching device, guarantees that the monitoring pulse can not superpose on time domain, and monitoring accuracy is higher, is suitable for the PON network of large splitting ratio.
4, the utility model device is in the CO(central office) inner can the monitoring whole PON optical-fiber network, do not want each optical fiber branch road of independent measurement, increase work efficiency, reduce the cost of overhaul.
The accompanying drawing explanation
Fig. 1 is whole principle schematic of the present utility model.
Fig. 2 is the inner principle schematic of data acquisition module.
Fig. 3 is transmission and the transmitting procedure schematic diagram of monitoring pulse.
Fig. 4 is reception and the data acquisition schematic diagram of monitoring pulse.
Embodiment
A kind of line fault of PON based on optical markings method monitoring device, as shown in Figure 1, comprise monitoring system, wavelength selector (WS), 1:2 fiber coupler, 1:N optical branching device and N fiber grating.Wherein the number of N is identical with the number of the optical network unit (ONU) of required monitoring.The value of N can be got infinity in theory, but considers actual effect, and in the utility model, the span of N is the arbitrary value in 2~128.In the utility model, described monitoring system, wavelength selector 1:2 fiber coupler and optical network unit all are arranged in central office (CO).
The input/output port of above-mentioned monitoring system shares an interface, and it mainly is comprised of LASER Light Source, fiber amplifier, optical circulator, photoelectric detector, data acquisition system and host computer.The output of LASER Light Source connects the first port of optical circulator through fiber amplifier, the second port of optical circulator is connected with the first port of wavelength selector, and the 3rd port of optical circulator is connected to the input port of photoelectric detector.The output of photoelectric detector is connected with the input of data acquisition system, and the output of data acquisition system is connected to host computer.In the utility model, LASER Light Source is the laser of narrowband light source.Fiber amplifier is erbium-doped fiber amplifier (EDFA).As shown in Figure 2, mainly by analog to digital converter, data storage and programmable logic device form data acquisition system.Described data acquisition system is mainly by analog to digital converter, and data storage and programmable logic device form; The output of programmable logic device is connection mode number converter and data storage respectively, the input of analog to digital converter is connected with the output of photoelectric detector, the output of analog to digital converter is connected with the input of data storage, and the output of data storage is connected with the input of host computer.The function of programmable logic device is that analog to digital converter and data storage are controlled and made the stable effectively operation of data acquisition.Wherein data storage is First Input First Output (FIFO) memory and/or random asccess memory (RAM).
Optical line terminal (OLT) is connected on first minute terminal of 1:2 fiber coupler, the second port of wavelength selector is connected on second minute terminal of 1:2 fiber coupler, and the terminal of closing of 1:2 fiber coupler is connected with the terminal of closing of 1:N optical branching device through an optical fiber main line.The N of a 1:N optical branching device output is connected with an optical network unit through an optical fiber branch road respectively.
N fiber grating is serially connected in respectively the optical network unit front end on N bar optical fiber branch road, and N fiber grating is different apart from the distance of 1:N optical branching device, the fiber grating on the adjacent fiber branch road is satisfied to the range difference Δ L of 1:N optical branching device:
ΔL ≥ T × C 2 × n eff
In formula: T-pulse signal duration.The propagation velocity of C-light.n effThe effective refractive index of-optical fiber.
In the utility model, the reflection wavelength of each fiber grating is all identical by wavelength with the permission of wavelength selector.The wavelength of fiber grating is generally the U wave band, and (1625nm~1675nm), avoided optical line terminal transmission 850nm, 1310nm and 1550nm wavelength used, make can not influence each other between monitor signal and signal of communication.
The line fault of the PON based on the optical markings method monitoring method that adopts the above-mentioned line fault of PON based on optical markings method monitoring device and realize, comprise the steps:
(1) transmission and the transmitting step of monitoring pulse signal, referring to Fig. 3:
(1.1) the monitoring pulse signal by the LASER Light Source emission is input to fiber amplifier.
(1.2), after fiber amplifier amplifies the monitoring pulse signal of inputting, output to the first port of optical circulator.
(1.3) optical circulator exports the monitoring pulse signal of its first port input to wavelength selector by its second port.
(1.4) wavelength selector carries out filtering to the monitoring pulse signal, namely only allow the monitoring pulse signal of specific wavelength in the monitoring pulse signal to pass through, the monitoring pulse signal of other wavelength will be cut, and the monitoring pulse signal becomes the monitoring pulse signal of single wavelength after by wavelength selector; Wherein specific wavelength refers to that wavelength selector allows the wavelength that passes through;
(1.5) the monitoring pulse signal of fiber coupler single wavelength that wavelength selector is sent into forms the coupling light wave with the light wave coupling of communicating by letter that optical line terminal is sent into, and the coupling light wave is transferred to the 1:N optical branching device on the optical fiber main line.
(1.6) the 1:N optical branching device by the coupling light ripple be divided into N part enter respectively the first optical fiber branch road, the second optical fiber branch road ..., N optical fiber branch road, form the first coupling light wave, the second coupling light wave ..., the N light wave that is coupled.
(1.7) first coupling light waves are transferred to the first fiber grating on the first optical fiber branch road will separate, and the first communication light wave continues to be transmitted to the first optical network unit by the first fiber grating, and the first monitoring pulse signal can be reflected by the first fiber grating;
The light wave that is coupled for the second time is transferred to the second fiber grating on the second optical fiber branch road will separate, and the second communication light wave continues to be transmitted to the second optical network unit by the second fiber grating, and the second monitoring pulse signal can be reflected by the second fiber grating;
By that analogy,
The N time coupling light wave is transferred to the N fiber grating on N optical fiber branch road will separate; N communication light wave continues to be transmitted to the N optical network unit by the N fiber grating, and N monitoring pulse signal can be reflected by the N fiber grating;
The reflection wavelength of described each fiber grating is all identical by wavelength with the permission of wavelength selector.
(2) reception and the data acquisition step of monitoring pulse signal: referring to Fig. 4;
(2.1) by first monitoring pulse signal uplink on the first optical fiber branch road of the first fiber grating reflection, second monitoring pulse uplink on the second optical fiber branch road of being reflected fully by the second fiber grating, N monitoring pulse uplink on N optical fiber branch road of being reflected fully by the N fiber grating by that analogy;
(2.2) because the fiber grating that is connected in series on each optical fiber branch road is different to the distance of 1:N optical branching device, the asynchronism(-nization) that the monitoring pulse signal that sends from LASER Light Source transmits at each optical fiber branch road, the monitoring pulse signal on each optical fiber branch road are arranged in order and transfer to 1:N optical branching device formation coupling monitoring pulse on time domain.
In the utility model, N fiber grating is different apart from the distance of 1:N optical branching device, the fiber grating on the adjacent fiber branch road is satisfied to the range difference Δ L of 1:N optical branching device:
ΔL ≥ T × C 2 × n eff
In formula: T-pulse signal duration.The propagation velocity of C-light.n effThe effective refractive index of-optical fiber.
(2.3) coupling monitoring pulse signal is divided into two-way when uplink is to the 1:2 fiber coupler on the optical fiber main line: first via coupling monitoring pulse signal transfers to optical line terminal via first minute terminal of 1:2 fiber coupler, and the second tunnel coupling monitoring pulse signal enters the second port of optical circulator via second minute terminal of 1:2 fiber coupler by wavelength selector;
(2.4) the second tunnel coupling monitoring pulse signal that enters from the second port of circulator, transfer to photoelectric detector via the 3rd port output of circulator;
(2.5) the coupling monitoring pulse signal in the light territory of in photoelectric detector, step (2.4) being sent into is converted to the coupling monitoring pulse signal in electric territory;
(2.6) coupling in electric territory monitoring pulse signal completes the storing process of analog-to-digital conversion and digital signal in data acquisition module, and data acquisition module is sent to host computer by the monitoring of the coupling in its memory pulse data by given pace;
(2.7) host computer receives reference pre-stored in actual measurement coupling monitoring pulse data that actual monitoring that data acquisition module sends into goes out and host computer and is coupled and monitors pulse data and compare; With reference to coupling monitoring pulse data, be wherein in the normal situation of each optical fiber branch road, the monitoring pulse that sends from LASER Light Source after each fiber grating reflection, the coupling monitoring pulse data when each optical fiber branch road that receives on host computer all works; This is with reference to all recording in advance at the beginning of the operation of coupling monitoring pulse data system, and later monitoring is all take this initial data as reference;
When surveying the comparison of coupling monitoring pulse data and reference coupling monitoring pulse data; 2 data respectively need to be divided into to N time-domain segment compares respectively; namely the first time-domain segment actual measurement coupling monitoring pulse data and the first time-domain segment compare with reference to surveying coupling monitoring pulse data; the second time-domain segment actual measurement coupling monitoring pulse data and the second time-domain segment compare with reference to surveying coupling monitoring pulse data; by that analogy, N time-domain segment actual measurement coupling monitoring pulse data and N time-domain segment compare with reference to surveying coupling monitoring pulse data;
If all time-domain segment actual measurement coupling monitoring pulse datas are all monitored pulse data when consistent with all time-domain segment with reference to surveying to be coupled, represent that all optical fiber branch roads are all normal; If when wherein a certain time-domain segment actual measurement coupling monitoring pulse data was inconsistent with reference to coupling monitoring pulse data with corresponding a certain time-domain segment, the corresponding optical fiber branch road of this time-domain segment was undesired.
In said method, the span of described N is between 2~128.The wavelength of described each fiber grating is all identical with the wavelength of selector, and the wavelength of fiber grating is generally U wave band (1625nm~1675nm), avoided optical line terminal transmission 850nm, 1310nm and 1550nm wavelength used, made can not influence each other between monitor signal and signal of communication.

Claims (5)

1. based on the PON line fault monitoring device of optical markings method, its feature as for: comprise monitoring system, wavelength selector, 1:2 fiber coupler, 1:N optical branching device and N fiber grating, wherein the number of N is identical with the number of the optical network unit of required monitoring;
The input/output port of above-mentioned monitoring system shares an interface, and it mainly is comprised of LASER Light Source, fiber amplifier, optical circulator, photoelectric detector, data acquisition system and host computer; The output of LASER Light Source connects the first port of optical circulator through fiber amplifier, the second port of optical circulator is connected with the first port of wavelength selector, and the 3rd port of optical circulator is connected to the input port of photoelectric detector; The output of photoelectric detector is connected with the input of data acquisition system, and the output of data acquisition system is connected to host computer;
Optical line terminal is connected on first minute terminal of 1:2 fiber coupler, the second port of wavelength selector is connected on second minute terminal of 1:2 fiber coupler, and the terminal of closing of 1:2 fiber coupler is connected with the terminal of closing of 1:N optical branching device through an optical fiber main line; The N of a 1:N optical branching device output is connected with an optical network unit through an optical fiber branch road respectively;
N fiber grating is serially connected in respectively the optical network unit front end on N bar optical fiber branch road, and N fiber grating is different apart from the distance of 1:N optical branching device, the fiber grating on the adjacent fiber branch road is satisfied to the range difference Δ L of 1:N optical branching device:
ΔL ≥ T × C 2 × n eff
In formula: T-pulse signal duration; The propagation velocity of C-light; n effThe effective refractive index of-optical fiber.
2. according to claim 1 based on the PON line fault monitoring device of optical markings method, its feature as for: the span of described N is between 2~128.
3. according to claim 1 based on the PON line fault monitoring device of optical markings method, its feature as for: described LASER Light Source is the laser of narrowband light source.
4. according to claim 1 based on the PON line fault monitoring device of optical markings method, its feature as for: described data acquisition system is mainly by analog to digital converter, and data storage and programmable logic device form; The output of programmable logic device is connection mode number converter and data storage respectively, the input of analog to digital converter is connected with the output of photoelectric detector, the output of analog to digital converter is connected with the input of data storage, and the output of data storage is connected with the input of host computer.
5. according to claim 1 based on the PON line fault monitoring device of optical markings method, its feature as for: the wavelength of described each fiber grating is all identical with the wavelength that the permission of wavelength selector is passed through.
CN2013203268018U 2013-06-07 2013-06-07 PON (Passive Optical Network) line fault monitoring device based on optical mark method Withdrawn - After Issue CN203301485U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2013203268018U CN203301485U (en) 2013-06-07 2013-06-07 PON (Passive Optical Network) line fault monitoring device based on optical mark method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2013203268018U CN203301485U (en) 2013-06-07 2013-06-07 PON (Passive Optical Network) line fault monitoring device based on optical mark method

Publications (1)

Publication Number Publication Date
CN203301485U true CN203301485U (en) 2013-11-20

Family

ID=49577464

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2013203268018U Withdrawn - After Issue CN203301485U (en) 2013-06-07 2013-06-07 PON (Passive Optical Network) line fault monitoring device based on optical mark method

Country Status (1)

Country Link
CN (1) CN203301485U (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103684584A (en) * 2014-01-03 2014-03-26 上海长跃通信技术有限公司 Optical fiber transmission quality automatic-monitoring system
CN108462530A (en) * 2016-12-12 2018-08-28 中兴通讯股份有限公司 A kind of optical line terminal test device

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103684584A (en) * 2014-01-03 2014-03-26 上海长跃通信技术有限公司 Optical fiber transmission quality automatic-monitoring system
CN108462530A (en) * 2016-12-12 2018-08-28 中兴通讯股份有限公司 A kind of optical line terminal test device

Similar Documents

Publication Publication Date Title
CN103297126B (en) The PON line fault monitoring method of optically-based labelling method and device thereof
CN106788696A (en) The monitoring of optical cable on-line intelligence and fault location system based on GIS platform
CN104202084B (en) A kind of device and method monitoring TDM optical network link failure
CN103323215B (en) A kind of light time domain reflection measuring apparatus and method
CN101984561A (en) System and method for detecting optical fiber faults of passive optical network
CN104601228A (en) System and method for positioning PON network optical fiber link failures
CN105530046B (en) Realize the method and system that luminous power and branch off attenuation failure are tested automatically
CN106788712A (en) Electric power optical cable on-line intelligence monitoring system
CN102761364A (en) Method and device for detecting optical time domain detection signal
CN102412902A (en) Optical network unit photoelectric device with optical time domain reflection function
CN107332101A (en) It is a kind of can Dynamic Execution optical time domain reflection detection component and detection method
CN203747825U (en) ONU optical module with optical fiber fault detection function
CN203747824U (en) Optical cable line fault point detector
CN203301485U (en) PON (Passive Optical Network) line fault monitoring device based on optical mark method
CN106685522B (en) A kind of network monitoring method and device based on poll Self Matching
CN110289905B (en) Device and method for accurately monitoring TWDM-PON fault by using FP laser
CN110266374B (en) Device and method capable of monitoring TDM-PON secondary branch circuit fault with high precision
CN102928740B (en) Intelligent collection type fault diagnosis and In-Line Temperature Measure System
CN201742408U (en) Optical time domain reflectometer and device and system thereof
CN110266375A (en) High-precision fault monitoring device and method towards TWDM-PON
CN110176957A (en) A kind of device and method of high-precision, Larger Dynamic range monitoring WDM-PON failure
WO2011070404A1 (en) Optical system and method for monitoring the physical structure of optical networks, based on otdr with remote detectors
CN105953942A (en) Distributed fiber based cable fault diagnosis system
CN105577458A (en) Device and method for positioning branch fault in passive optical access network
CN202939260U (en) Intelligent platform with fault diagnosis and on-line temperature measuring functions

Legal Events

Date Code Title Description
C14 Grant of patent or utility model
GR01 Patent grant
C25 Abandonment of patent right or utility model to avoid double patenting
AV01 Patent right actively abandoned

Granted publication date: 20131120

Effective date of abandoning: 20160622