CN102377486B - System for monitoring non-reflection faults in passive optical network (PON) optical link - Google Patents
System for monitoring non-reflection faults in passive optical network (PON) optical link Download PDFInfo
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Abstract
The invention discloses a system for monitoring non-reflection faults in a passive optical network (PON) optical link, and relates to the technical field of PON. The system comprises a local side and a user side which are connected through an optical distribution network, wherein the local side comprises an optical line terminal and an optical time domain reflector; the user side comprises a plurality of optical network units; the optical distribution network comprises a wavelength division multiplexing device, an optical switch and multilevel optical splitters, wherein the wavelength division multiplexing device is connected with the optical line terminal through a feeder line optical fiber; the optical switch is connected with the optical time domain reflector through a separate optical fiber, and one port of the optical switch is also connected with the wavelength division multiplexing device; and the multilevel optical splitters are respectively connected with the wavelength division multiplexing device and the optical switch, and the multilevel optical splitters are also respectively connected with the optical network units through distribution optical fibers. According to the system and a monitoring method of the system, diagnosis and accurate positioning of the faults of the feeder line optical fibers and the distribution optical fibers are simply and effectively realized under the condition of high branching ratio, and the problem of difficulty in positioning the faults when the system is in high branching ratio is solved.
Description
Technical field
The present invention relates to PON (Passive Optical Network, EPON) technical field, is specifically a kind of system of monitoring non-reflective fault in PON optical link.
Background technology
Because optical fiber communication has, transmission frequency bandwidth, message capacity are large, signal transmission quality advantages of higher, and this technology has in the communications field to be applied extremely widely.Optical Access Network FTTH has broad application prospects as the pith of in Networks of Fiber Communications.The interventional method of typical Optical Access Network comprises the PON cut-in method of P2P (Point to Point, point-to-point) and P2MP (Pointto Multi-Point, point-to-multipoint).PON system adopts the cut-in method of P2MP compared with P2P, has saved optical fiber cost greatly.
As shown in Figure 1, for the typical PON system P2MP structural representation that tape jam detects, it mainly contains three part compositions: local side apparatus, user side ONU (Optical Network Unit, optical network unit) and ODN (Optical Distribution Network, optical distribution network).Local side apparatus comprises OTDR (Optical Time Domain Reflecto-meter, optical time domain reflectometer) and OLT (Optical Line Terminal, optical line terminal), OLT provides Network Side Interface for PON system, a Fiber connection is passed through to an ODN network after closing road with the light signal of OTDR, ONU provides user side interface for PON system, is uply connected with ODN.ODN is the Passive Optical Components such as one or more levels optical splitter, OLT downlink data is transferred to each ONU along separate routes, gathered by multiple ONU upstream data simultaneously and be transferred to OLT.
The diagnosis and detection of above-mentioned typical PON system network failure is very important, also has a lot of patent to be described for optical fiber link fault detect at present.Application number is the Chinese patent of 20081025150.1, and describe local side and adopt optical switch, optical coupler and Fiber Analysis instrument, far-end arranges the method for fiber grating to carry out optical link quality monitoring; Describing in Chinese patent CN1866790A by increasing optical path adjusting box in ODN system, reaching each ONU and there is different range differences, the object that OTDR can test optical-fiber network Zhong Ge branch; The cooperation being described through webmaster management system and OTDR inside Chinese patent CN101217313A reaches PON diagnosing malfunction.In above-mentioned patent, local side all needs to place the optical switch of multipath, optical coupler, the reflector at ONU place and high performance Fiber Analysis instrument, and far-end then needs placement fiber grating.But technically there is dynamic range and the conflicting problem of precision in OTDR, its dynamic range is large, and precision is low, therefore based on current OTDR index, the problem of the quality detecting Distribution fibers is difficult to, the especially non-reflective event fault of Distribution fibers when branching ratio is very high.
In addition, current operator is in order to reduce PON primary construction cost, and the main Constructing ideas of " thin covering " that adopts saves initial investment." thin covering " refers to that optical cable carries out one-time construction by measure, but to be arranged on the products such as the optical splitter in corridor be modularized design, progressively can carry out dilatation.Therefore, the network of ODN is the structure of multistage light splitting, and articulation increases, and differential loss will be larger.In this case, realize the Distribution fibers fault after to multistage light splitting (comprising reflection event and non-reflective event fault) and carry out diagnosing that to detect be a very large difficulty, have to be solved.
Summary of the invention
For the defect existed in prior art, the object of the present invention is to provide a kind of system of monitoring PON optical link non-reflective fault, when high branching ratio, simple and effectively can realize diagnosis and the accurate location of feeder fiber and Distribution fibers fault, the problem of fault location difficulty when solving system high branching ratio.
For reaching above object, the invention provides a kind of system of monitoring non-reflective fault in PON optical link, comprise the local side and user side that are connected by optical distribution network, local side comprises optical line terminal and optical time domain reflectometer, user side comprises multiple optical network unit, described optical distribution network comprises: wavelength division multiplex device, is connected with optical line terminal by feeder fiber; Optical switch, be connected with optical time domain reflectometer by independent optical fiber, a branch port of optical switch also connects wavelength division multiplex device, and the test light signal of described optical time domain reflectometer is squeezed into feeder fiber by optical switch and wavelength division multiplex device, and monitors it; Multistage optical splitter, be connected respectively with optical switch with wavelength division multiplex device, multistage optical splitter also connects each optical network unit respectively by Distribution fibers, and the test light signal of described optical time domain reflectometer squeezes into Distribution fibers by luminous-power distributor, monitors Distribution fibers.
On the basis of technique scheme, described multistage optical splitter is formed by multiple luminous-power distributor cascade.
On the basis of technique scheme, described multistage optical splitter is formed by multiple luminous-power distributor two-level concatenation, and the branching ratio of each luminous-power distributor of the second level is equal.
On the basis of technique scheme, each luminous-power distributor of the described second level only has a branch, and each branch connects an optical network unit.
On the basis of technique scheme, the branching ratio of described first order luminous-power distributor is 1 × ml, cascade ml second level luminous-power distributor, the branching ratio of each second level luminous-power distributor is 2 × m2, wherein ml is the maximum branch number of first order luminous-power distributor, and m2 is the maximum branch number of second level luminous-power distributor.
On the basis of technique scheme, ml=4, m2=8 in described multistage optical splitter, maximum branch is than being ml × m2=32.
On the basis of technique scheme, described multistage optical splitter is formed by multiple luminous-power distributor two-level concatenation, and the branching ratio of each luminous-power distributor of the second level is unequal.
On the basis of technique scheme, multistage optical splitter comprises multiple monitoring mouth, and a branch port of optical switch is connected to feeder fiber by wavelength division multiplex device, and all the other branch port of optical switch are connected to the monitoring mouth of multistage optical splitter respectively.
On the basis of technique scheme, the operation wavelength of described optical time domain reflectometer is 1625nm or 1650nm.
Beneficial effect of the present invention is: a kind of system of monitoring PON optical link non-reflective fault of the present invention, and in actual applications, the OTDR dynamic range used reduces greatly (at least reducing by 6 to 9dB than typical); Under the condition realizing optical link detection, WDM (Wavelength Division Multiplexing, the wavelength division multiplexing) device used only has one, OSW (optical switch, optical switch) branch port number less, cost reduce; Under solving PON system high branching ratio situation simply and effectively by OSW, the problem of branch's fault (comprising nonreflective fault) cannot be located.
Accompanying drawing explanation
Fig. 1 is the typical PON system P2MP structural representation that in background technology, tape jam detects;
Fig. 2 is the schematic diagram that the present invention monitors the system embodiment of non-reflective fault in PON optical link;
Fig. 3 is the structural representation of the multistage optical splitters of branching ratio such as secondary;
Fig. 4 is the structure chart of most preferred embodiment in Fig. 3;
Fig. 5 is the structure chart that in Fig. 3, each luminous-power distributor only has the embodiment of a branch;
Fig. 6 is the structural representation of the secondary multistage optical splitter of branching ratio such as not;
Fig. 7 is the structure chart of an embodiment in Fig. 6.
Embodiment
Below in conjunction with drawings and Examples, the present invention is described in further detail.
As shown in Figure 2, an a kind of embodiment of monitoring the system of PON optical link non-reflective fault of the present invention, comprise the local side and user side that are connected by ODN, local side comprises OLT and OTDR, user side comprises multiple ONU, and described ODN comprises WDM device, OSW and multistage optical splitter.OLT is connected with the public port 1 of WDM device by feeder fiber, and OTDR is connected with the public port (i.e. com mouth) of OSW by an independent optical fiber.In the present embodiment, multistage optical splitter is formed (also can form for multiple luminous-power distributor multi-stage cascade) by 5 luminous-power distributor two-level concatenation, the branching ratio of OSW is 1 × 5, the value of OSW branch is identical with the quantity of luminous-power distributor in multistage optical splitter, and each luminous-power distributor has a monitoring mouth.A branch port P1 of OSW is connected to the port 3 of WDM device, all the other the branch port P2 ~ P5 of OSW is connected to monitoring mouth M1, M2, M4, M5 of multistage optical splitter respectively, multistage optical splitter is also connected with the port 2 of WDM device by a monitoring mouth M3, the luminous-power distributor connection wiring optical fiber respectively of described multistage optical splitter afterbody, every bar Distribution fibers connects an ONU.The test light signal of described OTDR is squeezed into feeder fiber by OSW and WDM device, and monitors feeder fiber; The test light signal of OTDR squeezes into Distribution fibers by multistage optical splitter, monitors Distribution fibers, and in the present embodiment, the operation wavelength first-selection of OTDR is 1625nm or 1650nm, plays optimum test effect.
The multistage optical splitter of branching ratio two kinds of situations such as described multistage optical splitter can be divided into the multistage optical splitter of the branching ratios such as secondary and secondary not.
As indicated at 3, be the structural representation of the multistage optical splitter of the branching ratios such as secondary, wherein comprise that 1 branching ratio is 1 × ml luminous-power distributor 0, a ml branching ratio is 2 × m2 luminous-power distributor, 1 ~ ml, whole ODN supports ml × m2 road branching ratio.The monitoring mouth M3 of the multistage optical splitter of the branching ratios such as secondary connects feeder fiber by WDM device, the monitoring mouth of 2 × m2 luminous-power distributor is M1, M2, M4 ~ Mml, connect with the branch port of OSW respectively, in addition, OSW also leaves a branch port P1 and is connected (as Fig. 2) with WDM device, and the com mouth of OSW and OTDR pass through Fiber connection.In such cases, each branch of first order luminous-power distributor 0 connects a second level luminous-power distributor 1 ~ ml, and each second level luminous-power distributor has m2 branch, is therefore called the multistage optical splitter of the branching ratios such as secondary.
As shown in Figure 5, be more special embodiment a kind of in the multistage optical splitter of the branching ratios such as secondary, as ml=4 in figure, m2=1, namely first order luminous-power distributor has 4 branches, and each branch connects a second level luminous-power distributor, and each second level luminous-power distributor only has a branch.The present embodiment is mainly used in the stricter high-end user of link failure positioning requirements, point-to-point mode can be adopted to realize monitoring, namely OTDR only monitors the optical fiber link of each high-end user, realizes Distribution fibers fault point diagnosing and the location of point-to-point PON.
As shown in Figure 2 and Figure 4, for the present invention's comparatively preferred embodiment, in the multistage optical splitter of the branching ratios such as secondary, always have 5 luminous-power distributors, comprise the first order luminous-power distributor 0 that a branching ratio is 1 × 4, and 4 branching ratios are 2 × 8 second level luminous-power distributors 1 ~ 4, each second level luminous-power distributor all has 8 branches, always have 4 × 8=32 bar branch, therefore whole ODN supports 32 tunnel branching ratios.OSW branching ratio is 1 × 5, and therefore OSW has 6 ports altogether, comprising P1 ~ P5 totally 5 branch port and com mouth; Branch's score light utensils such as secondary have 5 to monitor mouth M1 ~ M5, the branch port P1 of OSW is connected with the port 3 of WDM device, the port M3 of the multistage optical splitter of the branching ratios such as secondary is connected with the port 2 of WDM device, and the branch port P2 ~ P5 of OSW is connected with monitoring mouth M1, M2, M4, M5 of the multistage optical splitters of branching ratio such as secondary respectively.The OLT device downlink business light signal of local side connects through the port one of feeder fiber with WDM device, port 2 and the multistage optical splitter of WDM device are monitored mouth M3 and are connected, light signal enters into the multistage optical splitter of the branching ratios such as secondary and carries out optical power fluctuation, by downlink business optical signal transmission to each branch ONU; Uplink service light signal enters into WDM device after the multistage optical splitter of the branching ratios such as secondary, through WDM device transmission to feeder fiber, finally arrives OLT, completes the transmission of whole up-downgoing business light signal.
As indicated with 6, be the structural representation of the secondary multistage optical splitter of branching ratio such as not.Usually when network design, some community user numbers are few, and some community user numbers are many, the system of the multistage optical splitter of branching ratio such as utilize secondary not, can flexible configuration according to the quantity of user.The described secondary multistage optical splitter of branching ratio such as not comprises the luminous-power distributor that branching ratio is 1 × ml, and 2 × (m2 ~ mr) (r>3) luminous-power distributor, wherein m2, m3 ... in the branch of mr, element branches quantity can be had identical, or all the quantity of branch is all different, whole ODN supports that maximum branch ratio is
road.The monitoring mouth M3 of the described secondary multistage optical splitter of branching ratio such as is not connected with feeder fiber by WDM device, all the other monitoring mouths M1, M2, M4 ~ (Mml+1) connects with the branch port of OSW respectively, the system of the multistage optical splitter of branching ratio such as utilize this kind of secondary not, is applicable to the detection case adopting point-to-multipoint at low-end subscribers.
As shown with 7, for one of secondary Bu Deng branch score light device more preferably value embodiment, namely during ml=4, first order luminous-power distributor 0 has 4 branches, each branch connects a second level luminous-power distributor, in the luminous-power distributor of the second level, luminous-power distributor 1 only has a branch, luminous-power distributor 2 has 4 branches, luminous-power distributor 3 has 8 branches, luminous-power distributor 4 has 8 branches, namely luminous-power distributor 3 is identical with the numbers of branches of luminous-power distributor 4, but it is different with other numbers of branches, therefore be secondary Bu Deng branch score light device.
Based on the system of non-reflective fault in the monitoring PON optical link shown in Fig. 2, monitoring method provided by the invention specifically comprises the steps:
A01. local side OLT control OSW is switched to branch port P1, through the port 3 of WDM device, OSW is switched to feeder fiber path.
A02. open OTDR, make OTDR that test pulse occur, test light signal is driven into feeder fiber, detects feeder fiber, the operation wavelength first-selection of OTDR is 1625nm or 1650nm, plays most preferred effect.
A03. after feeder fiber detects, OLT is selected by OSW again, makes OSW be switched to branch to be measured in multistage optical splitter, as being switched to any one branch port of P2 to P5 in Fig. 2 by OSW, as OSW is switched to branch port P2.
A04. after branch to be measured selectes, open OTDR, make OTDR that test pulse occur, realize respectively detecting the Distribution fibers of each branch of multistage optical splitter ONU.As shown in Figure 4, above-mentioned branch port P2 connects with the monitoring mouth M1 of multistage optical splitter, realizes detecting the diagnosis of each branch (1 ~ 8) ONU after luminous-power distributor 1.
A05. repeat steps A 03 to A04, the Distribution fibers completing other branches to be measured detects.If OSW is switched to branch port P3, then branch port P3 connects with the monitoring mouth M2 of multistage optical splitter, realizes detecting the diagnosis of each branch ONU after luminous-power distributor 2; If OSW is switched to branch port P4, then branch port P4 connects with the monitoring mouth M4 of multistage optical splitter, realizes detecting the diagnosis of each branch ONU after luminous-power distributor 3; If OSW is switched to branch port P5, then branch port P5 connects with the monitoring mouth M5 of multistage optical splitter, realizes detecting the diagnosis of each branch ONU after luminous-power distributor 4.
The present invention is not limited to above-mentioned execution mode, and for those skilled in the art, under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications are also considered as within protection scope of the present invention.The content be not described in detail in this specification belongs to the known prior art of professional and technical personnel in the field.
Claims (7)
1. monitor the system of non-reflective fault in PON optical link for one kind, the local side comprising optical distribution network and connected by optical distribution network and user side, local side comprises optical line terminal and optical time domain reflectometer, and user side comprises multiple optical network unit, it is characterized in that, described optical distribution network comprises:
Wavelength division multiplex device, is connected with optical line terminal by feeder fiber;
Optical switch, be connected with optical time domain reflectometer by independent optical fiber, a branch port of optical switch also connects wavelength division multiplex device, and the test light signal of described optical time domain reflectometer is squeezed into feeder fiber by optical switch and wavelength division multiplex device, and monitors it;
Multistage optical splitter, be connected respectively with optical switch with wavelength division multiplex device, multistage optical splitter also connects each optical network unit respectively by Distribution fibers, and the test light signal of described optical time domain reflectometer squeezes into Distribution fibers by luminous-power distributor, monitors Distribution fibers;
Multistage optical splitter comprises multiple monitoring mouth, and a branch port of optical switch is connected to feeder fiber by wavelength division multiplex device, and all the other branch port of optical switch are connected to the monitoring mouth of multistage optical splitter respectively;
Described multistage optical splitter is formed by multiple luminous-power distributor cascade.
2. system of monitoring non-reflective fault in PON optical link as claimed in claim 1, it is characterized in that: described multistage optical splitter is formed by multiple luminous-power distributor two-level concatenation, the branching ratio of each luminous-power distributor of the second level is equal.
3. system of monitoring non-reflective fault in PON optical link as claimed in claim 2, is characterized in that: each luminous-power distributor of the described second level only has a branch, and each branch connects an optical network unit.
4. system of monitoring non-reflective fault in PON optical link as claimed in claim 2, it is characterized in that: the branching ratio of first order luminous-power distributor is 1 × m1, cascade m1 second level luminous-power distributor, the branching ratio of each second level luminous-power distributor is 2 × m2, wherein m1 is the maximum branch number of first order luminous-power distributor, and m2 is the maximum branch number of second level luminous-power distributor.
5. system of monitoring non-reflective fault in PON optical link as claimed in claim 4, is characterized in that: m1=4, m2=8 in described multistage optical splitter, and maximum branch is than being m1 × m2=32.
6. system of monitoring non-reflective fault in PON optical link as claimed in claim 1, it is characterized in that: described multistage optical splitter is formed by multiple luminous-power distributor two-level concatenation, the branching ratio of each luminous-power distributor of the second level is unequal.
7. system of monitoring non-reflective fault in PON optical link as claimed in claim 1, is characterized in that: the operation wavelength of described optical time domain reflectometer is 1625nm or 1650nm.
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| CN105095947A (en) * | 2014-05-19 | 2015-11-25 | 中兴通讯股份有限公司 | Passive optical label, optical reading/ writing device and intelligent optical distribution network |
| CN105634649A (en) * | 2014-10-31 | 2016-06-01 | 中国移动通信集团公司 | Colorless reconfigurable optical add-drop multiplexer and optical signal receiving method |
| CN104536093B (en) * | 2014-12-29 | 2017-10-24 | 武汉光迅科技股份有限公司 | A kind of multichannel multiplex for simulative surveillance PON system switches equipment |
| WO2017071827A1 (en) | 2015-10-30 | 2017-05-04 | Telefonaktiebolaget Lm Ericsson (Publ) | Protection apparatus for a bidirection optical link |
| CN107070544B (en) * | 2017-01-11 | 2023-06-27 | 上海嘉慧光电子技术有限公司 | Optical module, detection device using the same, and determination method |
| CN109617600B (en) * | 2018-12-28 | 2020-09-15 | 东南大学 | Detection pulse waveform self-debugging system and method based on PON link fault recognition |
| CN115133982A (en) * | 2021-03-26 | 2022-09-30 | 华为技术有限公司 | Optical splitting device, optical splitting system, passive optical network and optical fiber fault detection method |
| CN115967445B (en) * | 2022-06-29 | 2024-03-19 | 中兴通讯股份有限公司 | Method, equipment and system for generating optical network topology |
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| KR100687710B1 (en) * | 2004-11-20 | 2007-02-27 | 한국전자통신연구원 | Method and apparatus for monitering optical fiber of passive optical network system |
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| CN1333454A (en) * | 2000-07-12 | 2002-01-30 | 信息产业部武汉邮电科学研究院 | Optical cable real time monitoring system |
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