CN102291173A - Passive optical network failure detecting device and detecting method thereof - Google Patents

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

A kind of passive optical network fault checkout gear and detection method thereof

Technical field

The present invention is relevant, more detailed with the failure detector and the detection method thereof of network, is checkout gear and detection method thereof that a kind of OTDR of the chaotic laser light correlation method based on wavelength-tunable detects fault in the EPON.

Technical background

Passive optical network PON as the principal mode of Access Network of future generation, occupies an important position in fiber optic network communication, and prospect is extremely wide.The existing passive optical-fiber network mainly contains three parts and constitutes: i.e. optical line terminal OLT, Optical Distribution Network ODN and optical-fiber network subscriber unit ONU.Because its EPON has a plurality of subscriber units, the structure more complicated, branching ratio is more, and coverage is bigger, is carrying huge amount of information, and therefore, how research carries out fault detect to EPON is necessary.

Existing optical-fiber network detection technique is to utilize the OTDR of single wavelength, after breaking down in the EPON, subscriber unit does not receive useful information, utilize OTDR to detect again, because it surveys the untunable property of wavelength the OTDR of single wavelength, can only utilize sectional detecting method to carry out, detection has relative hysteresis quality, can't realize real-time detection.

In order to realize the real-time detection to EPON, the OTDR of wavelength-tunable becomes the research focus, 1996, utilizes adjustable laser to realize the OTDR of wavelength-tunable under the condition of two acoustooptic switch modulation^[1](Kuniaki Tanaka, Mitsuhiro Tateda, Measuring the individual attenuation distribution of passive branched optical network [J] .Photonics technology letters, 1996,8 (7): 915-917), utilize the fiber laser of length scanning formula in 2009, export the pseudorandom light pulse sequence, realized 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), utilized the mode of bi-orthogonal coded in 2010, realize the OTDR of wavelength-tunable, and used it for the research of optical network communication^[3](Shen Donghui, Xie Weilin, Dong Yi etc. based on the tunable wave length OTDR research [J] of bi-orthogonal coded. optical communication technique, 2010,4:39-41).

But the development of EPON communication at present is tending towards the miniature fiber network, therefore, needs a kind of new high-resolution, high-precision Detection Techniques.Time-of-flight method measuring distance and certainty of measurement that tradition OTDR adopts are contradiction on principle, the symbol width of pseudorandom light pulse sequence will be subject to electronic bottleneck in the correlation method of pseudorandom light pulse, precision can't break through, OTDR based on the chaotic laser light correlation method utilizes the correlation method of chaotic laser light correlation measurement with respect to time-of-flight method and pseudorandom light pulse, far measuring distance, the certainty of measurement height.

Technology formerly, single wavelength based on chaotic laser light correlation method OTDR, as publication number is CN101226100 a kind of " chaos light time domain reflectometer and method of measurement thereof ", and the chaotic laser light signal that the chaos light emitting devices is launched is divided into detection light and reference light by fiber coupler.Survey light retroeflection after circulator is transmitted in the testing fiber circuit and in photodetector, be converted into the signal of telecommunication, convert in the digital signal input signal processing unit through A/D converter by light signal; Reference light is received by photodetector, and light signal is converted into the signal of telecommunication, is input to signal processing apparatus through A/D converter again.Signal processing apparatus carries out cross-correlation to the two ways of digital signals of input.Concrete measuring principle is detection light I and the reference light II that chaos light is divided into, and establishes the reference light II and establishes the functional relation that the reference light II satisfies and be

, survey the functional relation that satisfies after the retroeflection of light I process testing fiber circuit

, its cross-correlation function then

When

The 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, handle the intensity and the two-way time that just can obtain to survey the light retroeflection by cross-correlation instrument or computer

Thereby, realize the detection of fault location and optical fiber transmission property.

Foregoing invention utilizes correlation method to handle, and has realized the fault detect of simple optical fiber.But, the chaotic laser light correlation method is used for optical network fault detects, have three problems: the one, how to realize the tunable of wavelength.The 2nd, detectable signal enters in the optical-fiber network, how to determine fault is in which paths in the network, further to determine the particular location of fault.The 3rd, how to be implemented in optical line terminal and to show detected fault message, realize the management and the detection of centralization.Still there is very big difficulty in this fault detect for optical-fiber network, and this also is the technical problem that realizes pressing in the optical network fault detection solution 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, how on the optical-fiber network path, to determine the problem of its fault particular location to solve, and then realize that the optical network fault of high accuracy, high-resolution and centralization detects.

In order to address the above problem and realize above-mentioned purpose, the measure that the present invention taked 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; The chaos signal source that contains a wavelength-tunable, the light detecting signal of launching network measuring enters optical-fiber network destination path to be measured through a wavelength division multiplexing unit light signal allocation, and 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 the multi-wavelength chaotic laser light under the ring feedback condition, by the chaos signal source that is arranged on the tunable filter realization wavelength-tunable in the feedback loop; Described signal processing unit is to be provided with the wavelength measurement meter in chaos correlation method device; Described wavelength measurement meter is spectrometer or wavemeter.

A kind of detection method that is used for above-mentioned passive optical network fault checkout gear, its described method is the chaotic laser light correlation method OTDR that is provided with a wavelength-tunable in EPON, the detectable signal of the chaos signal source of this OTDR wavelength-tunable emission is coupled to each optical-fiber network destination path in OTDR wavelength division multiplexing unit according to wavelength detects, the signal processing unit that again detectable signal is turned back to OTDR carries out correlation method to be handled.

In said method, described chaos signal source is that the ring feedback light is injected into the FP laser, produce the multi-wavelength chaotic signal, feedback light intensity and polarization state have optical attenuator and Polarization Controller to regulate, and in the light path of ring feedback, carry out filtering, realize the output of chaotic signal single wavelength, as the detectable signal of OTDR; Described signal processing unit is as the reference signal with the chaotic signal first via, a part is as detectable signal, detectable signal is coupled to corresponding optical-fiber network destination path in the wavelength division multiplexing unit according to its wavelength value, determines its wavelength by the wavelength measurement meter, and failure judgement network objectives path; The chaotic laser light signal of reflected back and the second tunnel reference signal formerly convert the signal of telecommunication to behind photodetector, converting digital signal to through A/D is input to signal processing unit and carries out correlation method and handle, correlation peak on the correlation curve that obtains promptly is the abort situation in the destination path in the EPON.

The OTDR that the present invention is based on wavelength-tunable chaotic laser light correlation method detects the checkout gear and the detection method thereof of passive optical network fault, compared with prior art, utilize FP semiconductor laser and adjustable filter to obtain the chaotic signal of tunable wave length, and in the signal processing of correlation method, be provided with the wavelength checkout gear, realized that in EPON centralization detects in real time to the fault in each network objectives path, and accurately orient concrete fault path and fault occurrence positions take place, realized the fault detect of high accuracy, high-resolution optical-fiber network.

Description of drawings

Fig. 1 is the basic structure schematic diagram of passive optical network PON.

Fig. 2 is the structural representation of OTDR in the 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.

Among the figure: the 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: the 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, be on the basis of existing OTDR, utilize tunable chaotic signal to do detectable signal, and to signal employing wavelength detection and correlation method processing, be implemented in the real-time online fault detect in each network objectives path in the EPON, and then accurately detect the particular location that breaks down, to adapt to high accuracy, the high-resolution centralization fault detect in the mininet detection.It is as follows at first to implement a kind of passive optical network fault checkout gear of the present invention.

As Fig. 1, 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, ODN carries out signal allocation through the Optical Distribution Network unit, and the signal after the distribution enters into optical-fiber network subscriber unit ONU through the 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 send in the tunable signal source, detectable signal is coupled in the network objectives path according to wavelength by the wavelength division multiplexing unit and detects, run into fault after, turn back to signal processing unit and handle.Can regulate detectable signal and observe testing result at optical line terminal, realize centralized management and real time fail diagnosis with this.

State on the implementation in the EPON checkout gear, its chaos signal source, as Fig. 3,FP semiconductor laser 1 is launched chaotic signal and is entered erbium-dopedfiber amplifier 3 byfirst circulator 2 and carry out the amplification of signal, be divided into two-way byfirst coupler 4, one the tunnel as output signal, one the tunnel injects back in the FP semiconductor laser as feedback signal and to produce chaotic signal, feedback light intensity and feedback polarization state of light are regulated by theoptical attenuator 7 and thePolarization Controller 8 that are in the feedback control loop, the output wavelength of chaotic laser light is by 6 controls of the tunable filter in the feedback control loop, and then the tunability of realization wavelength.

In implementation process, used wavelength division multiplexing unit can adopt the array waveguide grating of multi-wavelength passage or in the 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, throughsecond coupler 9, be divided into two-way, reference light and detection light, reference light is through the 3rd coupler 10, the first via enters intowavelength sight gauge 11, here can be a kind of its wavelength of observation in wavemeter or the spectrometer, determine the wavelength channel of corresponding wavelength division multiplexing unit, promptly determine the network objectives path of detecting with this; The second tunnel detectable signal that is used to wait for and reflect carries out related operation, survey light and enter into the wavelength division multiplexing unit through the3rd circulator 12, be coupled into optical-fiber network subscriber unit to be measured according to its wavelength by the wavelength channel of correspondence, run into fault and turn back to signal processing unit, carry out related operation with the second tunnel reference signal.The signal that two-way carries out related operation at first changes into the signal of telecommunication by first photodetector 13 and second photodetector 14, change into digital signal by an A/D converter 15 and the 2nd A/D converter 16 again, itssignal processing apparatus 17 can adopt computer or digital correlation instrument to carry out related operation, shows correlated results on display unit 18.In wavelength value and the network objectives path of associated picture definite detection and the abort situation in this network objectives path of optical line terminal, realized centralized management like this according to observation.

It is concrete that to implement a kind of fault detection method that is used for described passive optical network fault checkout gear as follows.

As Fig. 1-Fig. 4, the inventive method is the chaotic laser light correlation method OTDR that a wavelength-tunable is set in EPON, and the OTDR among the present invention mainly contains the chaos signal source of wavelength-tunable, and wavelength division multiplexing unit and signal processing unit constitute.Wherein the chaos signal source of OTDR and signal processing unit are installed in the optical line terminal OLT in the optical-fiber network, and the wavelength division multiplexing unit is installed among the Wavelength Assignment network ODN.When carrying out the optical-fiber network detection, the detectable signal of OTDR is coupled into each network objectives path in the Optical Distribution Network unit according to wavelength, detects.

In said method, chaos signal source is that the ring feedback light is injected into the FP laser, produce the multi-wavelength chaotic signal, feedback light intensity and polarization state have optical attenuator and Polarization Controller to regulate, and in the light path of feedback, add adjustable filter, realized the output of chaotic signal wavelengthtunable.

The conduct of a chaotic signal part is with reference to signal, a part is as detectable signal, the first via of reference signal is used to observe wavelength, determine network objectives path to be detected, detectable signal is coupled to according to its wavelength value in the corresponding network objectives path in the wavelength division multiplexing unit, runs into the chaotic laser light signal that the fault back reflection returns this wavelength; Behind photodetector, convert the chaotic laser light signal that reflects and the second tunnel reference signal formerly to the signal of telecommunication, converting computer or the digital correlation instrument that digital signal is input in the signal processing unit to through A/D carries out related calculation, there is a relevant peaks in breakpoint location corresponding on the correlation curve that obtains, orient the particular location of fault in this network objectives path with this, realized the real-time online detection.

Implementing said method is to detect in the prior art basis of simple optical fiber fault at the OTDR with the chaotic laser light correlation method, realized the OTDR of the chaotic laser light correlation method of tunable wave length, because the chaotic signal that the chaos signal source of OTDR is partly launched is a wavelength-tunable, being applied to EPON so measures, segmentation with respect to single wavelength OTDR detects, and this method can realize the real-time detection to network; Adopt correlation method to handle in signal processing to chaotic signal, with respect to the correlation measurement precision of traditional time-of-flight method and pseudo-random pulse and resolution all than higher; In signal processing unit, added the wavelength sight gauge,, realized real-time resolution the network objectives path to the wavelength real-time monitored; Just can detect at optical line terminal, realize the overall optical network is carried out the detection and the management of centralization each optical-fiber network destination path.

Claims (7)

Translated fromChinese

1.一种无源光网络故障检测装置，包括有：波长可调的混沌激光相关法OTDR； 1. A passive optical network fault detection device, comprising: a chaotic laser correlation method OTDR with adjustable wavelength;所述波长可调的混沌激光相关法OTDR含有一波长可调的混沌信号源，发射出网络检测的光探测信号经一波分复用单元光信号分配，进入待测光网络目标路径，遇到故障后光探测信号返回到一信号处理单元。The chaotic laser correlation method OTDR with adjustable wavelength contains a chaotic signal source with adjustable wavelength, and the optical detection signal emitted by the network is distributed through a wavelength division multiplexing unit optical signal, and enters the target path of the optical network to be tested. After a fault, the light detection signal is returned to a signal processing unit.2.如权利要求1所述的一种无源光网络故障检测装置，其所述一波长可调的混沌信号源是一FP半导体激光器（1）在环反馈条件下产生多波长混沌激光，由设置在反馈环中的可调滤波器（6）实现波长可调的混沌信号源。2. A kind of passive optical network fault detection device as claimed in claim 1, said a wavelength-tunable chaotic signal source is a FP semiconductor laser (1) that produces multi-wavelength chaotic laser under loop feedback conditions, by The adjustable filter (6) arranged in the feedback loop realizes the chaotic signal source with adjustable wavelength.3.如权利要求1所述的一种无源光网络故障检测装置，其所述信号处理单元是在混沌相关法装置中设置有波长测量计（11）。3. A passive optical network fault detection device according to claim 1, wherein said signal processing unit is provided with a wavelength measuring meter (11) in the chaos correlation method device.4.如权利要求3所述的一种无源光网络故障检测装置，其所述波长测量计（11）是光谱仪或者是波长计。4. A passive optical network fault detection device according to claim 3, wherein the wavelength measurement meter (11) is a spectrometer or a wavelength meter.5.一种用于权利要求1所述的无源光网络故障检测装置的检测方法，其所述方法是在无源光网络中设置有一个波长可调的混沌激光相关法OTDR，并将OTDR波长可调混沌信号源发射的探测信号在OTDR波分复用单元根据探测信号的波长耦合到各光网络目标路径进行检测，再将探测信号返回到OTDR的信号处理单元进行相关法处理。5. a detection method for the passive optical network failure detection device described in claim 1, its described method is to be provided with a wavelength-tunable chaotic laser correlation method OTDR in the passive optical network, and the OTDR The detection signal emitted by the wavelength-tunable chaotic signal source is coupled to the target path of each optical network according to the wavelength of the detection signal in the OTDR wavelength division multiplexing unit for detection, and then the detection signal is returned to the signal processing unit of the OTDR for correlation processing.6.如权利要求5所述的一种无源光网络故障检测装置的检测方法，其所述混沌信号源是环反馈光注入到FP激光器，产生多波长混沌信号，反馈光的强度和偏振态有光衰减器和偏振控制器调节，并在环反馈的光路中进行滤波，实现可调的混沌信号单一波长输出，作为OTDR的探测信号。6. the detection method of a kind of passive optical network fault detection device as claimed in claim 5, its described chaotic signal source is that ring feedback light is injected into FP laser, produces multi-wavelength chaotic signal, the intensity and polarization state of feedback light It is adjusted by an optical attenuator and a polarization controller, and is filtered in the optical path of the loop feedback to realize an adjustable single-wavelength chaotic signal output as the detection signal of the OTDR.7.如权利要求5所述的一种无源光网络故障检测装置的检测方法，其所述信号处理单元是将混沌信号一部分作为参考信号，一部分作为探测信号，参考信号的第一路由波长测量计确定其波长，判断故障网络目标路径；探测信号在波分复用单元按照其波长值耦合到相应的光网络目标路径，遇到故障反射回到信号处理单元，返回的探测信号和在先第二路参考信号由光信号转化成电信号，再经A/D转换成数字信号进行相关法处理，得到的相关曲线上的相关峰值即是无源光网络中目标路径中的故障位置。7. The detection method of a kind of passive optical network fault detection device as claimed in claim 5, its said signal processing unit is to use a part of the chaotic signal as a reference signal, a part as a detection signal, and the first routing wavelength measurement of the reference signal Determine its wavelength and determine the target path of the faulty network; the detection signal is coupled to the corresponding optical network target path in the wavelength division multiplexing unit according to its wavelength value, and reflected back to the signal processing unit in case of a fault, the returned detection signal and the previous first The two-way reference signal is converted from an optical signal to an electrical signal, and then converted into a digital signal by A/D for correlation processing. The correlation peak on the obtained correlation curve is the fault location in the target path in the passive optical network.

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