CN102291173B - Passive optical network failure detecting device and detecting method thereof - Google Patents
Passive optical network failure detecting device and detecting method thereof Download PDFInfo
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Abstract
The invention relates to a passive optical network failure detecting device and a detecting method thereof. The device comprises an OTDR (optical time-domain reflectometer) based on a tunable wavelength chaotic laser correlation method; the OTDR comprises a chaotic signal source with a tunable wavelength; an optical detecting signal emitting network detection is distributed by a wavelength division multiplexing unit optical signal to enter an optical network target route to be detected, and the optical detecting signal returns to a signal processing unit when facing a failure; the method comprises the following steps of: setting an OTDR based on the wavelength tunable chaotic laser correlation method, detecting the detecting signal emitted by the chaotic signal source with adjustable OTDR wavelength in the OTDR wavelength division multiplexing unit according to wavelength coupled in various optical network target routes, and returning the detecting signal to the signal processing unit of the OTDR to perform correlative processing. In the invention, an FP (Fabry-Perot) semiconductor laser and tunable filter are utilized to obtain wavelength-tunable chaotic signal, and a wavelength meter is arranged in the correlative signal processing, so that the centralization failure detection with high precision and high resolution to the passive optical network is realized.
Description
Technical field
Failure detector and the detection method thereof of the present invention and network are relevant, more specifically, are checkout gear and the detection methods thereof that a kind of OTDR of the chaotic laser light correlation method based on Wavelength tunable detects fault in EPON.
Technical background
Passive optical network PON, as the principal mode of Next Generation Access, occupy an important position in fiber optic network communication, prospect is extremely wide.Existing passive optical-fiber network mainly contains three parts and forms: i.e. optical line terminal OLT, Optical Distribution Network ODN and optical-fiber network subscriber unit ONU.Because its EPON has multiple subscriber unit, complicated structure, branching ratio is more, and coverage is larger, carries huge amount of information, and therefore, how research carries out fault detect to EPON is necessary.
Existing optical-fiber network detection technique is the OTDR utilizing Single wavelength, after breaking down in EPON, subscriber unit does not receive useful information, recycling OTDR detects, due to the untunable property of its detection wavelength of OTDR of Single wavelength, sectional detecting method can only be utilized to carry out, detect and there is relative hysteresis quality, real-time detection cannot be realized.
In order to realize the real-time detection to EPON, the OTDR of Wavelength tunable becomes study hotspot, 1996, achieves the OTDR of Wavelength tunable under the condition utilizing adjustable laser to modulate at two acoustooptic switch
[1](Kuniaki Tanaka, Mitsuhiro Tateda, Measuring the individual attenuation distribution of passive branched optical network [J] .Photonics technology letters, 1996,8 (7): 915-917), within 2009, utilize the fiber laser of length scanning formula, export pseudorandom light pulse sequence, achieve the OTDR of correlation method Wavelength tunable
[2](Woojin Shin, Bong-Ahn Yu, Yeung Lak Lee. Wavelength tunable optical time-domain reflectometry based on wavelength swept fiber laser employing two-dimensional digital micro-mirror array [J] .Optical Communication, 2009,282 (6): 1191-1195), within 2010, utilize the mode of bi-orthogonal coded, achieve the OTDR of Wavelength tunable, and use it for the research of optical network communication
[3](Shen Donghui, Xie Weilin, Dong Yi etc. the tunable wave length OTDR based on bi-orthogonal coded studies [J]. optical communication technique, 2010,4:39-41).
But the development of current EPON communication is tending towards miniature fiber network, therefore, a kind of new high-resolution, high-precision Detection Techniques are needed.The time-of-flight method measuring distance that tradition OTDR adopts and certainty of measurement are contradiction in principle, in the correlation method of pseudorandom light pulse, the symbol width of pseudorandom light pulse sequence will be limited to electronic bottleneck, precision cannot break through, OTDR based on chaotic laser light correlation method utilizes chaotic laser light correlation measurement relative to the correlation method of time-of-flight method and pseudorandom light pulse, far measuring distance, certainty of measurement is high.
In first technology, Single wavelength based on chaotic laser light correlation method OTDR, as the one " chaos light time domain reflectometer and method of measurement thereof " that publication number is CN101226100, the chaotic laser light signal launched by chaos light emitting devices is divided into detection light and reference light by fiber coupler.Detection light is transmitted into retroeflection after in testing fiber circuit through circulator and, in photodetector, is converted into the signal of telecommunication by light signal, converts in digital signal input signal processing unit through A/D converter; Light signal, by photoelectric detector, is converted into the signal of telecommunication by reference light, then is input to signal processing apparatus through A/D converter.The two ways of digital signals of signal processing apparatus to input carries out cross-correlation.Concrete measuring principle is the detection light I and reference light II that are divided into by chaos light, if reference light II functional relation of setting reference light II to meet as
, the functional relation that detection light I meets after the retroeflection of testing fiber circuit
, then its cross-correlation function
.When
time, there is peak value in cross-correlation function.The peak value of cross-correlation function is relevant with retroreflection light intensity.Based on this principle, carry out processing the intensity and two-way time that just can obtain the retroeflection of detection light by cross-correlation instrument or computer
, thus realize the detection of fault location and optical fiber transmission property.
Foregoing invention utilizes correlation method process, achieves the fault detect of simple optical fiber.But, chaotic laser light correlation method is used for optical network fault and detects, have three problems: one is how to realize wavelength tunable.Two is that detectable signal enters in optical-fiber network, how to determine fault is in which paths in network, to determine the particular location of fault further.Three is how to realize showing at optical line terminal the fault message detected, realizes management and the detection of centralization.Still there is very large difficulty in this fault detect for optical-fiber network, this is also realize technical problem in the urgent need to address in optical network fault detection at present.
Summary of the invention
Based on above-mentioned prior art, the invention provides a kind of passive optical network fault checkout gear and detection method thereof, on optical-fiber network path, how to determine the problem of its fault particular location to solve, so realize high accuracy, high-resolution the optical network fault of centralization detect.
In order to solve the problem and realize above-mentioned purpose, the measure that the present invention takes is a kind of passive optical network fault checkout gear and detection method thereof.
A kind of passive optical network fault checkout gear, includes: the chaotic laser light correlation method OTDR of Wavelength tunable.
The chaotic laser light correlation method OTDR of described Wavelength tunable; Chaos signal source containing a Wavelength tunable, the light detecting signal launching network detection distributes through a wavelength division multiplexing unit light signal, and enter optical-fiber network destination path to be measured, light detecting signal turns back to a signal processing unit.
In technique scheme, the chaos signal source of a described Wavelength tunable is that a FP semiconductor laser produces multi-wavelength chaotic laser light under ring feedback condition, is realized the chaos signal source of Wavelength tunable by the tunable filter be arranged in feedback loop; Described signal processing unit is provided with wavelength measurement meter in chaos correlation method device; Described wavelength measurement meter is spectrometer or wavemeter.
A kind of detection method for above-mentioned passive optical network fault checkout gear, method described in it is the chaotic laser light correlation method OTDR being provided with a Wavelength tunable in EPON, the detectable signal that the chaos signal source of this OTDR Wavelength tunable is launched is coupled to each optical-fiber network destination path at OTDR wavelength division multiplexing unit according to wavelength detect, then signal processing unit detectable signal being turned back to OTDR carries out correlation method process.
In the above-mentioned methods, described chaos signal source is that ring feedback light is injected into FP laser, produce multi-wavelength chaotic signal, the intensity of feedback light and polarization state have optical attenuator and Polarization Controller to regulate, and filtering is carried out in the light path of ring feedback, realize chaotic signal single wavelength to export, as the detectable signal of OTDR; Described signal processing unit is as reference signal using the chaotic signal first via, a part is as detectable signal, detectable signal is coupled to corresponding optical-fiber network destination path at wavelength division multiplexing unit according to its wavelength value, determines its wavelength by wavelength measurement meter, and failure judgement network objectives path; The chaotic laser light signal be reflected back and the second tunnel reference signal formerly convert the signal of telecommunication to after photodetector, convert digital signal to through A/D to be input to signal processing unit and to carry out correlation method process, namely correlation peak on the correlation curve obtained is the abort situation in EPON in destination path.
The OTDR that the present invention is based on Wavelength tunable chaotic laser light correlation method detects checkout gear and the detection method thereof of passive optical network fault, compared with prior art, FP semiconductor laser and adjustable filter is utilized to obtain the chaotic signal of tunable wave length, and wavelength detecting device is provided with in the signal transacting of correlation method, achieve the fault of centralization to each network objectives path in EPON to detect in real time, and accurately orient concrete fault generation path and fault occurrence positions, achieve the fault detect of high accuracy, high-resolution optical-fiber network.
Accompanying drawing explanation
Fig. 1 is the basic structure schematic diagram of passive optical network PON.
Fig. 2 is the structural representation of OTDR in EPON.
Fig. 3 is the chaos source structure schematic diagram of the Wavelength tunable of OTDR of the present invention.
Fig. 4 is the signal processing unit structural representation of OTDR of the present invention.
In figure: 1:FP semiconductor laser; 2: the first optical circulators; 3: amplifier; 4: the first couplers; 5: the second optical circulators; 6: tunable filter; 7: optical attenuator; 8: optical polarization controller; 9: the second couplers; 10: the three couplers; 11: wavelength sight gauge; 12: the three optical circulators; 13: the first photodetectors; 14: the second photodetectors; 15: the first A/D converters; 16: the second A/D converters; 17: signal processing apparatus; 18: display unit.
Embodiment
Below in conjunction with accompanying drawing, the specific embodiment of the present invention is further detailed.
Implement a kind of passive optical network fault checkout gear provided by the present invention and fault detection method thereof, on the basis of existing OTDR, tunable chaotic signal is utilized to do detectable signal, and wavelength detecting and correlation method process are adopted to signal, realize the real-time online fault detect in each network objectives path in EPON, and then accurately detect the particular location broken down, to adapt to the high accuracy in mininet detection, high-resolution centralization fault detect.First a kind of passive optical network fault checkout gear of the present invention is implemented as follows.
As Fig. 1, the present embodiment is in conjunction with existing EPON, provide the brief configuration schematic diagram of EPON, wherein, optical line terminal OLT, launch signal of communication, carry out signal distribution through Optical Distribution Network unit ODN, the signal after distribution enters into optical-fiber network subscriber unit ONU through network objectives path.
As Fig. 2, a kind of EPON checkout gear of the present invention mainly includes three parts, i.e. chaos signal source, wavelength division multiplexing unit and signal processing unit.Wherein, chaos signal source, signal processing unit is installed in optical line terminal OLT, the detectable signal that tunable signal source sends, detectable signal to be coupled in network objectives path according to wavelength by wavelength division multiplexing unit and to detect, and after running into fault, turns back to signal processing unit and processes.Can detectable signal be regulated at optical line terminal and observe testing result, achieving centralized management and real-time fault diagnosis with this.
State in EPON checkout gear on the implementation, its chaos signal source, as Fig. 3, FP semiconductor laser 1 is launched chaotic signal and is entered by the first circulator 2 amplification that erbium-doped fiber amplifier 3 carries out signal, two-way is divided into by the first coupler 4, one tunnel is as output signal, one tunnel is injected back in FP semiconductor laser as feedback signal and is produced chaotic signal, the intensity of feedback light and the polarization state of feedback light are regulated by the optical attenuator 7 be in feedback control loop and Polarization Controller 8, the output wavelength of chaotic laser light is controlled by the tunable filter 6 in feedback control loop, and then realize the tunability of wavelength.
In implementation process, wavelength division multiplexing unit used can adopt in the array waveguide grating of multi-wavelength passage or Wave decomposing multiplexer any one.
Signal processing unit wherein, as Fig. 4, the signal that signal processing unit receives, a part is the chaotic laser light signal that chaos signal source directly sends, through the second coupler 9, be divided into two-way, reference light and detection light, reference light is through the 3rd coupler 10, the first via enters into wavelength sight gauge 11, here can be that one in wavemeter or spectrometer observes its wavelength, determine the wavelength channel of corresponding wavelength division multiplexing unit with this, namely determine the network objectives path detected; Related operation is carried out for the detectable signal waited for and reflect in second tunnel, detection light enters into wavelength division multiplexing unit through the 3rd circulator 12, optical-fiber network subscriber unit to be measured is coupled into by the wavelength channel of correspondence according to its wavelength, run into fault and turn back to signal processing unit, carry out related operation with the second tunnel reference signal.First the signal that two-way carries out related operation changes into the signal of telecommunication by the first photodetector 13 and the second photodetector 14, digital signal is changed into again by an A/D converter 15 and the 2nd A/D converter 16, its signal processing apparatus 17 can adopt computer or digital correlation instrument to carry out related operation, and display unit 18 shows correlated results.Determine the abort situation in network objectives path and this network objectives path detected at optical line terminal according to the wavelength value of observation and associated picture like this, achieve centralized management.
A kind of fault detection method for described passive optical network fault checkout gear of concrete enforcement is as follows.
As Fig. 1-Fig. 4, the inventive method is the chaotic laser light correlation method OTDR arranging a Wavelength tunable in EPON, and the OTDR in the present invention, mainly contains the chaos signal source of Wavelength tunable, wavelength division multiplexing unit, and signal processing unit is formed.Wherein the chaos signal source of OTDR and signal processing unit are arranged in the optical line terminal OLT in optical-fiber network, and wavelength division multiplexing cellular installation is in Wavelength Assignment network ODN.When carrying out optical-fiber network and detecting, the detectable signal of OTDR is coupled into each network objectives path at Optical Distribution Network unit according to wavelength, detects.
In the above-mentioned methods, chaos signal source is that ring feedback light is injected into FP laser, produce multi-wavelength chaotic signal, the intensity of feedback light and polarization state have optical attenuator and Polarization Controller to regulate, and in the light path of feedback, add adjustable filter, achieve the output of chaotic signal wavelengthtunable.
A chaotic signal part is as reference signal, a part is as detectable signal, the first via of reference signal is for observing wavelength, determine network objectives path to be detected, detectable signal is coupled in corresponding network objectives path according to its wavelength value at wavelength division multiplexing unit, runs into the chaotic laser light signal that fault back reflection returns this wavelength; The chaotic laser light signal reflected and the second tunnel reference signal is formerly converted to the signal of telecommunication after photodetector, convert digital signal to through A/D and be input to computer in signal processing unit or digital correlation instrument carries out related calculation, there is a relevant peaks in breakpoint location corresponding on the correlation curve obtained, orient the particular location of fault in this network objectives path with this, achieve real-time online and detect.
Implementing said method is detecting in the prior art basis of simple optical fiber fault with the OTDR of chaotic laser light correlation method, achieve the OTDR of the chaotic laser light correlation method of tunable wave length, because the chaotic signal of the chaos signal source fractional transmission of OTDR is Wavelength tunable, so be applied to EPON measure, detect relative to the segmentation of Single wavelength OTDR, this method can realize the real-time detection to network; In signal processing, correlation method process is adopted to chaotic signal, relative to the correlation measurement precision of traditional time-of-flight method and pseudo-random pulse and resolution all higher; In signal processing unit, add wavelength sight gauge, to wavelength real-time monitored, achieve the real-time resolution to network objectives path; Just can detect each optical-fiber network destination path at optical line terminal, achieve detection and the management of whole optical-fiber network being carried out to centralization.
Claims (3)
1. a passive optical network fault checkout gear, includes: the chaotic laser light correlation method OTDR of Wavelength tunable;
The chaotic laser light correlation method OTDR of described Wavelength tunable contains chaos signal source, wavelength division multiplexing unit and signal processing unit;
The chaos signal source of a described Wavelength tunable is that a FP semiconductor laser (1) produces chaotic laser light under ring feedback condition, carries out filtering, realize the chaos signal source of Wavelength tunable by the tunable filter be arranged in feedback loop (6) to feedback light;
Described signal processing unit is that the chaotic signal sent by chaos signal source is a part of as reference signal, and a part is as detectable signal, and the first via of reference signal determines its wavelength by wavelength measurement meter (11), failure judgement network objectives path; Detectable signal is coupled to corresponding optical-fiber network destination path at wavelength division multiplexing unit according to its wavelength value, run into fault and reflect back into signal processing unit, the detectable signal returned and formerly the second tunnel reference signal change into the signal of telecommunication by light signal, convert digital signal to through A/D again and carry out correlation method process, namely the correlation peak on the correlation curve obtained is the abort situation in EPON in destination path.
2. the detection method for passive optical network fault checkout gear according to claim 1, method described in it is the chaotic laser light correlation method OTDR being provided with a Wavelength tunable in EPON, and the detectable signal that OTDR Wavelength tunable chaos signal source is launched is coupled to each optical-fiber network destination path at OTDR wavelength division multiplexing unit according to the wavelength of detectable signal and detects, then signal processing unit detectable signal being turned back to OTDR carries out correlation method process.
3. the detection method of a kind of passive optical network fault checkout gear as claimed in claim 2, chaos signal source described in it is that ring feedback light is injected into FP laser, produce chaotic signal, the intensity of feedback light and polarization state have optical attenuator and Polarization Controller to regulate, and filtering is carried out in the light path of ring feedback, realize adjustable chaotic signal single wavelength to export, as the detectable signal of OTDR.
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| CN103248447A (en) * | 2012-02-09 | 2013-08-14 | 北京邮电大学 | Wavelength division multiplexing passive optical network system |
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| WO2020194879A1 (en) * | 2019-03-27 | 2020-10-01 | 日本電気株式会社 | Light-transmission-path-spectrum measurement device, light-transmission-path system, light-transmission-path-spectrum measurement method, and computer-readable medium |
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| CN110635842B (en) * | 2019-10-11 | 2022-08-05 | 太原理工大学 | Passive wavelength division multiplexing network optical fiber fault detection system and detection method thereof |
| CN113949444B (en) * | 2020-07-17 | 2023-05-12 | 华为技术有限公司 | Fault detection method, network equipment and system of optical switching device |
| CN114499656B (en) * | 2021-12-24 | 2023-10-03 | 中国电子科技集团公司第三十四研究所 | Real-time online monitoring device and monitoring method for long-distance optical cable |
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