WO2012024977A1 - 无源光网络光纤故障的检测系统和方法 - Google Patents

无源光网络光纤故障的检测系统和方法 Download PDF

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Publication number
WO2012024977A1
WO2012024977A1 PCT/CN2011/076448 CN2011076448W WO2012024977A1 WO 2012024977 A1 WO2012024977 A1 WO 2012024977A1 CN 2011076448 W CN2011076448 W CN 2011076448W WO 2012024977 A1 WO2012024977 A1 WO 2012024977A1
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Prior art keywords
signal
optical path
optical
fiber
path detection
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Ceased
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PCT/CN2011/076448
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English (en)
French (fr)
Inventor
贝劲松
徐继东
苏婕
陆建鑫
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ZTE Corp
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ZTE Corp
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Priority to US13/818,937 priority Critical patent/US9036138B2/en
Priority to CA2809318A priority patent/CA2809318C/en
Priority to EP11819352.3A priority patent/EP2611047A4/en
Publication of WO2012024977A1 publication Critical patent/WO2012024977A1/zh
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/84—Systems specially adapted for particular applications
    • G01N21/88—Investigating the presence of flaws or contamination
    • G01N21/95—Investigating the presence of flaws or contamination characterised by the material or shape of the object to be examined
    • G01N21/958—Inspecting transparent materials or objects, e.g. windscreens
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/07—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems
    • H04B10/071—Arrangements for monitoring or testing transmission systems; Arrangements for fault measurement of transmission systems using a reflected signal, e.g. using optical time domain reflectometers [OTDR]
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G01M11/30—Testing of optical devices, constituted by fibre optics or optical waveguides
    • G01M11/31—Testing of optical devices, constituted by fibre optics or optical waveguides with a light emitter and a light receiver being disposed at the same side of a fibre or waveguide end-face, e.g. reflectometers
    • G01M11/3109—Reflectometers detecting the back-scattered light in the time-domain, e.g. OTDR
    • G01M11/3136—Reflectometers detecting the back-scattered light in the time-domain, e.g. OTDR for testing of multiple fibers
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/27—Arrangements for networking
    • H04B10/272—Star-type networks or tree-type networks
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0278—WDM optical network architectures
    • H04J14/0282—WDM tree architectures
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04J—MULTIPLEX COMMUNICATION
    • H04J14/00—Optical multiplex systems
    • H04J14/02—Wavelength-division multiplex systems
    • H04J14/0287—Protection in WDM systems
    • H04J14/0293—Optical channel protection
    • H04J14/0295—Shared protection at the optical channel (1:1, n:m)
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
    • G01M11/00—Testing of optical apparatus; Testing structures by optical methods not otherwise provided for
    • G01M11/30—Testing of optical devices, constituted by fibre optics or optical waveguides
    • G01M11/31—Testing of optical devices, constituted by fibre optics or optical waveguides with a light emitter and a light receiver being disposed at the same side of a fibre or waveguide end-face, e.g. reflectometers
    • G01M11/3109—Reflectometers detecting the back-scattered light in the time-domain, e.g. OTDR

Definitions

  • the present invention relates to the field of communications, and in particular to a system and method for detecting a fiber fault in a passive optical network.
  • BACKGROUND OF THE INVENTION The rapid development of network technologies and the popularization of network applications, such as network communication and online shopping, and online entertainment have become part of modern life, and the existing access network copper (wired) system is far from satisfactory.
  • This high-speed and broadband demand, while the passive optical network (PON) has broadband, high-speed, environmental protection and energy-saving features, is the best candidate to replace the existing access network, it is being operated by the vast majority Businesses are accepted and deployed to meet growing communications users and faster and better monthly service needs.
  • a passive optical network is a point-to-multipoint optical fiber access technology. As shown in FIG.
  • a passive optical network includes an optical line terminal (OLT), an optical network unit (ONU), and an optical network unit (ONU).
  • An optical distribution network (ODN) which is usually connected by an optical line terminal OLT through an optical power splitter (referred to as a splitter) of the optical distribution network ODN to a point-to-multipoint structure composed of a plurality of optical network units ONU.
  • ODN optical distribution network
  • ODR optical path detection device
  • OTDR Optical Time Domain Reflectometer
  • a branch fiber fails, and it is hoped that the fault can be quickly detected and the fault can be located and repaired without affecting the services of other branch fibers.
  • an OTDR When an OTDR is used to detect such a point-to-multipoint network at the OLT of the central office, it is relatively accurate to detect whether the primary kilo-fiber is normal, but the following two problems will be encountered when detecting the signal of the branched optical fiber. 1. If the distance between part of the branch fiber to the splitter is approximately equal, the OTDR cannot distinguish which branch fiber signal is. Unless the high-resolution OTDR is used, the highest resolution that can be provided now is 2 meters. Actual demand. 2.
  • the Rayleigh reflected signal of the branch fiber will have a large loss when passing through the splitter.
  • the signal such as the OTDR passes through the splitter to the end of the branch fiber and is then totally reflected (ie, without reflection loss) passing through the splitter to the OTDR.
  • the filter transmits all the light with a wavelength of 1625 nm or less, but the light emitted by the OTDR with a wavelength of 1625 nm or more can increase the light reflected by the port by 6 dB, and then the high-resolution OTDR can be used. According to whether there is reflected light to determine whether the branch fiber is faulty, but when there is a fault on the branch fiber, because the reflected light on the branch fiber is not enhanced by the optical filter, there is still the phenomenon that the reflected light is submerged in the noise. Therefore, the exact location where the branch fiber fault occurs cannot be determined.
  • a primary object of the present invention is to provide a detection system and method for a fiber optic failure of a passive optical network to solve the above problem that the branch fiber failure cannot be determined.
  • a detection system for a fiber optic failure of a passive optical network including: an optical path detection device OTDR, configured to emit an optical path detection signal corresponding to a wavelength of a branch fiber, and receive a path detection reflection signal, Determining whether there is a fault in the primary or secondary fiber according to the state of the optical path detection reflected signal; the wavelength division multiplexing coupler is configured to introduce the optical path detection signal onto the primary kilometer fiber, And transmitting the optical path detection reflection signal of the main kilo fiber transmission to the OTDR; the wavelength selection combiner is configured to transmit the optical path detection signal on the main kilo fiber to the branch fiber selector, and receive the received fiber optic selector from the branch The optical path detection reflected signal is guided back to the main kilometer fiber; the branch fiber selector is configured to transmit the optical path detection signal to the corresponding wavelength selection router, and transmit the optical path detection reflection signal from the wavelength selective router to the wavelength selective coupling The wavelength selection router is connected to the corresponding optical network unit
  • the wavelength division multiplexing coupler is further configured to receive a downlink signal of the optical line terminal, and introduce the downlink signal to the main kilo fiber, and separate the optical path detection reflection signal and the uplink signal transmitted by the main kilo fiber, and transmit the uplink signal.
  • the optical line terminal; the wavelength selective coupler is further configured to separate the optical path detection signal and the downlink signal transmitted by the main kilofiber, transmit the downlink signal to the optical splitter, and set the uplink signal transmitted by the optical splitter to transmit the uplink signal.
  • the system further includes: a splitter configured to transmit the downlink signal to all of the wavelength selective routers, and receive an uplink signal transmitted by each wavelength selective router to transmit the uplink signal to the wavelength selective coupler;
  • the wavelength selection router is further configured to transmit the downlink signal to the connected optical network unit, and separate the uplink signal and the optical path detection reflection signal of the optical network unit, and transmit the separated uplink signal to the optical splitter.
  • the wavelength division multiplexing coupler is a first optical filter
  • the first optical filter includes: a first interface, configured to be connected to the optical line terminal to transmit an uplink signal and a downlink signal; and a second interface, configured to be connected to the OTDR,
  • the optical path detection signal is transmitted to the main kilo fiber, and the optical path detection reflection signal is transmitted to the OTDR;
  • the universal interface is set to be connected to the main kilo fiber.
  • the second wavelength filter includes: a first interface, configured to be connected to the optical splitter to transmit an uplink signal and a downlink signal; and a second interface, configured to be connected to the branch fiber selector
  • the optical path detection signal is transmitted to the branch fiber selector to transmit the optical path detection reflection signal to the main kilofiber; the universal interface is set to be connected to the main kilo fiber.
  • the branch fiber selector is an arrayed waveguide grating, and the arrayed waveguide grating comprises: a universal interface, which is arranged to be connected to the wavelength selective combiner; and a plurality of grating branch inlets and outlets, which are arranged to be connected to the wavelength selective router on each fiber branch.
  • the wavelength selection router is a third optical filter, and the third optical filter includes: a first interface, configured to be connected to the optical splitter to transmit an uplink signal and a downlink signal; and a second interface, configured to be connected to the branch fiber selector, to receive Optical path detection signal, and transmission of optical path detection reflection signal to branch fiber selection
  • the universal interface is configured to be connected to the optical network unit through the branch fiber, transmit the optical path detection signal received by the second interface to the optical network unit, and receive the optical path detection reflected signal from the branch optical fiber.
  • Each of the first optical filter, the second optical filter, and the third optical filter is a thin film filter that reflects a signal of a wavelength detection wavelength and transmits a signal of a non-optical detection wavelength.
  • a method for detecting a fiber fault of a passive optical network including: an optical path detecting device OTDR transmitting an optical path detecting signal corresponding to a wavelength of a branch fiber; and a wavelength division multiplexing coupler receiving optical path Detecting the signal, transmitting the optical path detection signal to the wavelength selective combiner through the primary kilo-fiber; the wavelength selective coupler transmitting the optical path detection signal to the corresponding wavelength selective router through the branch fiber selector; the branching fiber is passed by the corresponding wavelength selection router Transmitting the optical path detection signal to the optical network unit; wherein, the optical path detection signal generates an optical path detection reflection signal during transmission, and the optical path detection reflection signal is transmitted to the OTDR along an optical path opposite to the optical path detection signal; The state of the optical
  • the wavelength division multiplexing coupler receiving the optical path detecting signal further includes: the wavelength division multiplexing coupler receiving the downlink signal of the optical line terminal, and introducing the downlink signal to the main kilo fiber; the wavelength selective coupler passing through the branch
  • the optical fiber selector transmits the optical path detection signal to the corresponding wavelength selection router, including: the wavelength selection combiner separates the optical path detection signal and the downlink signal transmitted by the main kilo fiber, transmits the downlink signal to the optical splitter, and transmits the downlink signal by the optical splitter.
  • the method includes: Each wavelength selection router transmits a downlink signal to the optical network unit connected thereto through the connected branch fiber.
  • the method further includes: the wavelength selection router separates the uplink signal of the optical network unit and the optical path detection reflection signal, and the separated uplink signal is transmitted to the optical line terminal along an optical path opposite to the downlink signal.
  • the optical path detection signal on the main kilo-fiber is forwarded to the branch fiber selector using a wavelength selective coupler instead of being transmitted to the optical splitter, thereby avoiding the loss of the optical path detection signal by the optical splitter while also passing the wavelength
  • the router is selected to forward the optical path detection reflection signal on the branch fiber to the branch fiber selector, which solves the problem that the branch fiber cannot be determined to be faulty due to the loss of the optical path detection reflection signal, and can quickly locate the fault branch fiber and Maintenance, reducing operator operating and maintenance costs.
  • FIG. 1 is a schematic structural diagram of a passive optical network according to the related art
  • FIG. 2 is a schematic structural diagram of an optical path detecting passive optical network system according to the related art
  • FIG. 3 is a schematic diagram of Embodiment 1 of the present invention.
  • FIG. 4 is a schematic structural diagram of a wavelength division multiplexing coupler according to Embodiment 2 of the present invention;
  • FIG. 4 is a schematic diagram of a structure of a wavelength selective coupler according to Embodiment 2 of the present invention
  • 6 is a schematic structural diagram of a branch fiber selector according to Embodiment 2 of the present invention.
  • FIG. 7 is a schematic diagram of a structure of a wavelength selective router according to Embodiment 2 of the present invention.
  • FIG. 8 is a schematic diagram of a fiber failure of a passive optical network according to Embodiment 3 of the present invention. Flowchart of the detection method of the passive optical network according to Embodiment 4 of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
  • the present invention will be described in detail with reference to the accompanying drawings.
  • FIG. 3 is a schematic structural diagram of a detection system for a fiber optic failure of a passive optical network according to an embodiment of the present invention. This embodiment uses a passive optical network composed of three optical network units as an example to describe an optical network.
  • the units are a first optical network unit 102, a second optical network unit 104, and a third optical network unit 106, respectively;
  • the system further includes an optical distribution network 20 and an optical line terminal 30; the present detection system inserts a wavelength division multiplexing coupler 42 at the optical line terminal 30 for connecting the optical path detecting device OTDR 40, and at the optical distribution network 20, inserting three
  • the optical modules are: a wavelength selective combiner 206, a branch fiber optic selector 208, and a wavelength selective router, wherein the wavelength selection router and the optical network unit are corresponding to each other, and the first wavelength selection router 210a and the second wavelength are respectively used in this embodiment.
  • the router 210b and the third wavelength selection router 210c are selected.
  • the optical path detecting device OTDR 40 is configured to emit an optical path detecting signal corresponding to the wavelength of the branch fiber, receive the optical path detecting reflected signal, and determine the main kilo fiber according to the state of the optical path detecting reflected signal or Whether the branch fiber has a fault; the wavelength division multiplexing coupler 42 is configured to introduce the optical path detection signal onto the main kilo fiber, and transmit the optical path detection reflection signal transmitted by the main kilo fiber to the OTDR 40; the wavelength selective combiner 206 The optical path detection signal on the primary kilo-fiber is transmitted to the branch fiber selector 208, and the received optical path detection reflection signal from the branch fiber selector 208 is returned to the primary kilo-fiber; the branch fiber selector 208, And transmitting the optical path detection signal to the corresponding wavelength selection router, and transmitting the optical path detection reflection signal from the wavelength selection router to the wavelength selective coupler 206; wherein the wavelength selection router and the optical network unit are
  • the corresponding wavelength selection routers in the embodiment are described by taking the first wavelength selection router 210a as an example.
  • the first wavelength selection router 210a is connected to the first optical network unit 102 through the branch fibers. And transmitting the optical path detection signal to the first optical network unit 102; and transmitting the optical path detection reflection signal on the branch fiber to the branch fiber selector 208.
  • 210b and 210c both of which may be thin film filters, for example, thin film filters of the sideband type. If the optical path detection wavelength is selected in the U band, that is, 1625 nm to 1675 nm, the thin film filter will be selected as a sideband filter.
  • the thin film filter will be selected as a wideband filter, that is, a signal reflecting a wavelength in the C-band, a signal transmitting a wavelength other than the C-band, and a branch fiber selector.
  • the arrayed waveguide grating will also choose to operate in the C-band.
  • a wavelength splitter 212 is disposed between the wavelength selective coupler 206 and the wavelength selection router (the first wavelength selection router 210a, the second wavelength selection router 210b, and the third wavelength selection router 210c) in the detection system shown in FIG.
  • the connection between the device 212 and the optical splitter 212 and other devices is indicated by a broken line to indicate that it does not transmit the optical path detection signal and the optical path detection reflected signal, and is only used for transmitting the uplink signal and the downlink signal.
  • the OTDR 40 is a device capable of tunable optical wavelength, and can adjust the wavelength of the corresponding optical path detection signal emitted by the OTDR 40 according to the branch fiber to be detected, so that the optical path detection signals of different wavelengths are transmitted along different branch fibers, thereby achieving Detecting whether the branch fiber is faulty.
  • each branch fiber has a wavelength selection router connected thereto, not every wavelength selection router transmits an optical path detection signal.
  • the wavelength of the optical path detection signal is selected by the branch fiber selector.
  • the corresponding wavelength selection router transmits the optical path detection signal, and the other wavelength selection routers do not have the optical path detection signal transmission.
  • the branch fiber selector of this embodiment can close the light of the wavelength by the channel that does not correspond to the wavelength.
  • the optical path detection signal on the primary kilo-fiber is forwarded to the branch fiber selector 208 by using the wavelength selective coupler 206 instead of being transmitted to the optical splitter, thereby avoiding the loss of the optical path detection signal by the optical splitter.
  • the optical path detection reflection signal on the branch fiber is forwarded to the branch fiber selector 208 through the wavelength selection router, which avoids the loss caused by the optical path detection reflection signal after passing through the optical splitter, thereby ensuring the optical path detection reflected signal to the utmost extent.
  • the strength solves the problem that the branch fiber cannot be determined to be faulty due to the loss of the optical path detection reflected signal, and the specific position of the fault can be determined according to the timing at which the optical path detection reflection signal is abnormal.
  • Embodiment 2 The detection system shown in FIG. 3 in the above Embodiment 1 can be attached to the original passive optical network system, and does not affect the operation of the original system when detecting the failure of the optical fiber, and the following is still shown in FIG.
  • the detection system of the optical fiber fault of the source optical network is taken as an example for description.
  • the operation process of the optical path detection signal and the communication signal is mainly described.
  • the system includes: a wavelength tunable OTDR 40, a wavelength division multiplexing coupler 42, a wavelength selective coupler 206, a branch fiber selector 208, and more than one of the splitters 212.
  • the connected wavelength selection routers which are the first wavelength selection router 210a, the second wavelength selection router 210b, and the third wavelength selection router 210c, respectively.
  • the wavelength division multiplexing coupler 42 is connected to the OTDR 40 and the optical line terminal 30; is connected to the wavelength selective coupler 206 through the main kilofiber; the wavelength selective coupler 206 is connected to the optical splitter 212 and the branch fiber selector 208;
  • the selector 208 is connected to each of the wavelength selection routers, that is, to the first wavelength selection router 210a, the second wavelength selection router 210b, and the third wavelength selection router 210c of the present embodiment; each wavelength selection router passes through a corresponding branch fiber
  • the optical network unit of the present embodiment is the first optical network unit 102, the second optical network unit 104, and the third optical network unit 106.
  • the first wavelength selection router 210a passes the first A branch fiber is connected to the first optical network unit 102; the second wavelength selection router 210b is connected to the second optical network unit 104 via the second branch fiber, and the third wavelength selection router 210c passes through the third branch fiber and the third optical network unit 106.
  • the OTDR 40 is configured to transmit an optical path detection signal of a specific wavelength to the corresponding branch fiber to the wavelength division multiplexing coupler 42 and determine whether the main kilo fiber and the corresponding branch fiber exist according to whether the received optical path detection reflection signal is abnormal. malfunction.
  • the optical path detection reflection signal may be a Fresnel reflection signal or a Rayleigh reflection signal.
  • the wavelength division multiplexing coupler 42 is configured to introduce the received optical path detection signal and the downlink signal of the optical line terminal (OLT) 30 onto the primary kilo-fiber, and transmit the optical path detection and reflection signal separated from the primary kilo-fiber. To the OTDR 40, the separated uplink signal is transmitted to the optical line terminal 30.
  • the wavelength selective combiner 206 is configured to separate the optical path detection signal from the primary kilo-fiber downlink signal and transmit it to the branch fiber selector 208; the remaining downlink signals are transmitted to the beam splitter 212; and the received branch fiber
  • the optical path detection reflection signal of the selector 208 is conducted back to the main kilo-fiber, and the upstream signal transmitted through the optical splitter 212 is transmitted to the main kilo-fiber.
  • the branch fiber selector 208 is configured to direct the optical path detection signal to the associated outlet according to the wavelength of the optical path detection signal, to enter the wavelength selective router connected thereto, and to select from the wavelength selective path
  • the optical path detection reflection signal of the branch fiber of the device is transmitted to the wavelength selective coupler 206.
  • the optical splitter 212 is configured to transmit the downlink signal to all of the wavelength selective routers connected thereto, and receive the uplink signals transmitted by all the wavelength selective routers, and transmit the uplink signals to the wavelength selective coupler 206.
  • the wavelength selection router (that is, the first wavelength selection router 210a, the second wavelength selection router 210b, and the third wavelength selection router 210c of the present embodiment) is configured to transmit the downlink signal from the optical splitter 212 to the branch fiber, where the implementation
  • the second wavelength selection router 210b and the third wavelength selection router 210c are further configured to transmit the uplink signal on the branch fiber to the optical splitter 212.
  • the first wavelength selection router 210a is further configured to separate the optical path from the uplink signal of the branch fiber.
  • the detected reflected signal is transmitted to the branch fiber selector 208, and the remaining separated uplink signals are transmitted to the beam splitter 212.
  • the wavelength division multiplexing combiner 42 is disposed at the central optical line terminal 30 in this embodiment.
  • the wavelength division multiplexing coupler 42 may be composed of a thin film filter (TFF).
  • the thin film filter can reflect light of the optical path detection wavelength, but transmits light of the non-optical detection wavelength.
  • the thin film filter includes: a first interface (represented by “P"), configured to be connected to the optical line terminal 30, transmitting (transmitting) the uplink signal and the downlink signal, and the wavelengths of the uplink signal and the downlink signal in this embodiment are both smaller than the light.
  • the wavelength of the detection signal; the second interface (represented by “R"), is set to be connected to the OTDR40, transmits the optical path detection signal to the main kilo-fiber, and transmits the optical path detection reflection signal to the OTDR 40; C" indicates), set to connect to the main kilofiber.
  • the thin film filter is used to introduce the optical path detection signal outputted by the OTDR 40 onto the main kilometer fiber, and transmit the optical path detection reflection signal to the OTDR 40 while maintaining communication between the optical line terminal 30 and the normal uplink and downlink signals of the optical network unit. contacts.
  • the wavelength selective coupler 206 is disposed at the entrance of the beam splitter 212. As shown in FIG. 5, the wavelength selective coupler 206 may be composed of a thin film filter (TFF).
  • TTFF thin film filter
  • the thin film filter reflects light of the optical path detection wavelength, but transmits light of the non-optical detection wavelength.
  • the thin film filter includes: a first interface (represented by “P"), configured to be connected to the optical splitter 212, and transmitting an uplink signal and a downlink signal.
  • the wavelengths of the uplink signal and the downlink signal in this embodiment may both be smaller than the optical path detection signal.
  • the wavelength of the second interface (represented by “R") is set to be connected to the branch fiber selector 208, and the optical path detection signal is transmitted to the branch fiber selector 208 to transmit the optical path detection reflection signal to the main kilo fiber;
  • the interface (represented by “C”) is set to be connected to the primary kilofiber.
  • the thin film filter is used for introducing the optical path detection signal to the branch fiber selector, and guiding the optical path detection and reflection signal of the branch fiber back to the main kilo-fiber, while maintaining the normal uplink and downlink signals of the optical line terminal 30 and the optical network unit. Communication.
  • a branch fiber selector 208 is provided next to the splitter 212 of the optical distribution network 20, and the branch fiber selector 208 is a passive device. Referring to FIG. 6, the branch fiber selector 208 is composed of Arrayed Waveguide Gratings (AWG).
  • AWG Arrayed Waveguide Gratings
  • the arrayed waveguide grating comprises: a general purpose interface (denoted by "C"), arranged to be connected to the wavelength selective combiner 206; a plurality of grating branches (indicated by "1 to N"), set to be associated with each fiber branch
  • the upper wavelength selection router is connected, and is configured to transmit the optical path detection signal to the corresponding wavelength selection router according to the wavelength of the optical path detection signal.
  • the branch fiber selector 208 In order to make the branch fiber selector 208 truly passive, the AWG should be independent of the ambient temperature, that is, the change of the ambient temperature, such as -20 ° C to 60 ° C, has no effect on the AWG operating parameters and performance, otherwise the AWG needs a temperature. Control the device to keep it stable.
  • the choice of the operating wavelength range of the AWG is related to the tuning range of the OTDR used by the customer.
  • the wavelength In order to reduce the operation of the PON, the wavelength needs to avoid the upstream and downstream wavelength bands, according to the OTDR wavelength of ITU-T L.66. It is stipulated that its operating wavelength range is generally U-band, ie 1625 nm to 1675 nm. If necessary, you can also choose C-band, or other bands, as long as you avoid the normal working band of the passive optical network. In this case, the above filter and OTDR should also be adjusted accordingly.
  • the AWG channel spacing is typically 100 GHz, and 50 GHz spaced AWGs can be selected as needed.
  • the number of channels should be selected corresponding to the number of splits of the splitter 212.
  • the ODN of the split ratio of 1:32 is matched with 32 channels of AWG.
  • the basic working principle is that different wavelengths of optical signals travel in different channels in the AWG, and their channels are connected to the branch fibers through a wavelength selective router, so that the branch fibers are identified by the wavelength of the optical path detection signal of the OTDR, that is, light of different wavelengths.
  • the detection signal detects its corresponding branch fiber.
  • a wavelength selective router is connected in front of each branch fiber of the optical splitter 212.
  • the wavelength selective router of this embodiment may be composed of a thin film filter (TFF).
  • the thin film filter reflects light of 1625 nm or more (wavelength of OTDR), but transmits light of 1625 nm or less.
  • the thin film filter includes: a first interface (represented by “P”), configured to be connected to the optical splitter 212, and transmitting an uplink signal and a downlink signal.
  • the wavelengths of the uplink signal and the downlink signal in this embodiment may both be smaller than the optical path detection signal.
  • the second interface (represented by “R"), is configured to be coupled to the branch fiber selector 208, to receive the optical path detection signal, and to transmit the optical path detection reflected signal to the branch fiber selector 208; C" indicates), configured to connect to the optical network unit through the branch fiber, transmit the optical path detection signal received by the second interface to the optical network unit, and receive the optical path detection reflected signal from the branch fiber.
  • the thin film filter is configured to introduce an optical path detection signal from the branch fiber selector 208 onto the branch fiber, and direct the optical path detection reflection signal of the branch fiber back to the branch fiber selector 208 while maintaining the optical line terminal 30 and The communication between the normal uplink and downlink signals of the optical network unit.
  • the wavelength division multiplexing coupler 42, the wavelength selective coupler 206, and the wavelength selective routers (210a, 210b, and 210c) all use the same type of thin film filter that reflects signals having a wavelength above 1625 nm, and transmits A signal with a wavelength below 1625 nm. This choice simplifies system design and reduces costs.
  • the optical path detection system composed of the above series of auxiliary optical function modules can intelligently and quickly detect and locate the faults of the main kilofiber and any branch fiber by using an adjustable OTDR in the office. . Moreover, by selecting the optical path detection signals of different wavelengths to detect the branch fibers associated with them, the signal overlap of the equal length branch fibers is avoided and cannot be distinguished. At the same time, both the optical path detection signal and the optical path detection and reflection signal are bypassed by the optical splitter and returned to the main kilo-fiber. This avoids the attenuation of the optical path detection signal and the optical path detection reflection signal by the optical splitter, and ensures that the OTDR can receive its optical path. Detect the reflected signal.
  • Step S802 The optical path detecting device OTDR transmits an optical path detecting signal of a wavelength corresponding to the branch fiber.
  • Step S804 The wavelength division multiplexing coupler receives the optical path detecting signal, and transmits the optical path detecting signal to the wavelength selective coupling through the primary optical fiber.
  • Step S806 the wavelength selective coupler transmits the optical path detection signal to the corresponding wavelength selection router through the branch fiber selector; the optical wavelength detection signal is transmitted to the optical network unit by the corresponding wavelength selection router through the branch fiber; The optical path detection signal generates an optical path detection reflection signal during transmission, and the optical path detection reflection signal is transmitted to the OTDR along an optical path opposite to the optical path detection signal; wherein, the opposite optical path refers to the same optical device transmitted through, but transmits The opposite direction.
  • Step S808 The OTDR determines whether the main kilo fiber or the branch fiber has a fault according to the state of the optical path detection reflected signal.
  • the optical network module selected in this embodiment may be implemented in the manner provided in Embodiment 2.
  • the wavelength division multiplexing coupler, the wavelength selective coupler and the wavelength selective router all use the same type of thin film filter, the film The filter reflects the signal of the optical path detection wavelength and transmits the signal of the non-optical detection wavelength. It will not be detailed here.
  • the optical path detection signal on the main kilo-fiber is forwarded to the branch fiber selector by using the wavelength selective coupler instead of being transmitted to the optical splitter, thereby avoiding the loss of the optical path detection signal by the optical splitter, and also passing the wavelength.
  • the router is selected to forward the optical path detection reflection signal on the branch fiber to the branch fiber selector, which avoids the loss caused by the optical path detection reflection signal after passing through the optical splitter, thereby ensuring the intensity of the optical path detection reflected signal to the maximum extent and solving the problem.
  • the problem that the branch fiber is faulty cannot be determined due to the loss of the optical path detection reflection signal, and the specific position of the failure can be determined based on the timing at which the optical path detection reflection signal is abnormal.
  • Embodiment 4 In order to realize the optical fiber system for intelligently detecting a passive optical network, first, some modifications are made to the passive optical network, and some passive optical functional modules are added. In this embodiment, a wavelength division multiplexing coupler is added to the optical line terminal according to the manner of FIG.
  • the main function is to connect the OTDR to the main 1000 fiber, so that the optical path detection signal (ie, the signal transmitted by the OTDR) It can enter the passive optical network system, and the corresponding optical path detection reflected signal can be transmitted to the OTDR through the network.
  • the optical path detection signal ie, the signal transmitted by the OTDR
  • its main function is to separate the optical path detection signal transmitted by the OTDR from the main kilo fiber to the branch fiber selector, and transmit the optical path detection and reflection signal of the branch fiber back to the main Thousands of fibers. At the same time it guarantees normal communication of uplink and downlink signals.
  • Inserting a wavelength selective router in front of each branch fiber after the optical splitter its main function is to introduce the optical path detection signal from the branch fiber selector into the branch fiber, and to reflect the optical path detection reflection signal of the branch fiber from the uplink signal. The separation is transmitted to the branch fiber selector, and the uplink and downlink communication is guaranteed to operate normally.
  • the wavelength selective router separates it from the upstream signal into the AWG grating interface to which it is connected, via the AWG-guided wavelength selective coupler.
  • the OTDR can intelligently test the entire passive optical network system.
  • the following shows the entire optical path detection process using the system shown in Figure 3. See Figure 9, Passive Optical Network.
  • the method for detecting the fiber fault includes the following steps: Step S902: Adjusting the wavelength of the detection signal of the OTDR according to the branch fiber to be measured, and the OTDR transmitting the optical path detection signal according to the adjusted wavelength; when the passive optical network needs to be detected, firstly in the process
  • the OTDR is connected to the wavelength division multiplexing coupler, and then 40 pairs of a desired measuring branch fiber are selected, and the corresponding optical path detection wavelength is selected, and the wavelength of the OTDR ⁇ ba detection signal is adjusted to the wavelength, if In the U-band, the wavelength range is generally between 1625 nm and 1675 nm. If it is the C-band, the wavelength range is generally between 1528 nm and 1560 nm.
  • Step S904 The optical path detection signal is transmitted into the main kilo-fiber through the R interface of the WDM multiplexer connected to the OTDR, and the reflected signal (ie, the optical path detection reflected signal) returns the original path.
  • Step S906 The optical path detection signal is transmitted to the C interface of the wavelength selective coupler through the primary kilofiber, and then separated from the R interface to the general interface of the branch fiber selector (ie, AWG);
  • Step S908 Branch The wavelength of the optical fiber selector optical signal detection signal is introduced into the corresponding grating outlet, and enters the R interface of the wavelength selective router connected to the grating outlet;
  • Step S910 The optical path detection signal is output from the C interface of the wavelength selective router to The branch fiber connected thereto is transmitted to the optical network unit ONU connected to the C interface.
  • the optical path detection transmitting signal will have an abnormal signal, which will be quickly discovered by the OTDR and can be quickly located.
  • the optical path detection signal will be transmitted to the C interface of the wavelength selective coupler, and then separated from the R interface to the general interface of the AWG of the branch fiber selector, and then the wavelength of the optical path detection signal It is imported into its corresponding raster exit, enters the R interface of the wavelength selective router connected to it, and then outputs from its C interface to the branch fiber connected to it, and transmits it to the ONU connected to it.
  • the reflected signal of the optical path detection signal (ie, the optical path detection reflected signal) returns along the optical path opposite thereto, that is, through the R interface of the wavelength selective router to the C interface, to the grating branch of the AWG of the branch fiber selector, and the AWG.
  • the universal interface enters the R interface of the wavelength selective coupler connected to it, and then outputs from the C interface, enters the main kilofiber, passes through the transmission of the primary kilofiber to the C interface of the wavelength division multiplexing coupler, and is then separated from its R interface.
  • the output is returned to the OTDR, so each time the OTDR will show an optical path detection reflection signal of one main kilofiber plus one branch fiber.
  • Step S912 Determine whether the main kilo fiber or the branch fiber has a fault according to the state of the optical path detection reflected signal on the OTDR. If other branch fibers are to be detected, the above steps need to be repeated, that is, the wavelength of the light emitted by the OTDR is adjusted to the wavelength corresponding to the branch fiber, and then the optical path detection signal is emitted, and the OTDR will receive the corresponding optical path detection reflection signal. According to whether the reflected signal is abnormal according to the optical path, it can be judged whether there is a fault or not, and the fault is located. Repeat the above steps until the end of the measurement. The communication between the OLT and the ONU can still be maintained in the normal state during the detection process. Taking the system structure shown in FIG.
  • the downlink signal forwarding process is as follows:
  • the optical line terminal OLT sends a downlink signal, and the wavelength division multiplexing coupler receives the downlink signal of the optical line terminal.
  • the downlink signal is imported into the main kilometer fiber;
  • the wavelength selection combiner separates the optical path detection signal and the downlink signal transmitted by the main kilofiber, transmits the downlink signal to the optical splitter, and the downlink signal is transmitted by the optical splitter to all the wavelength selective routers.
  • the wavelength selection router transmits the downlink signal to the optical network unit connected thereto through the connected branch fiber;
  • the optical path detection reflected signal of the optical fiber is transmitted to the OTDR through the opposite optical path of the optical path detection signal through the wavelength selective router.
  • the downlink signal sent by the optical line terminal OLT is transmitted through the wavelength division multiplexing coupler, passes through the main kilo fiber to the wavelength selective combiner, and then passes through the filter to the optical splitter, and the splitter passes the splitter to reach each wavelength selection.
  • the router passes through the filter on the wavelength selection router to each branch fiber, and then reaches the corresponding ONU through the branch fiber.
  • the uplink signal forwarding process is as follows:
  • the uplink signal sent by the ONU passes through the branch fiber to reach the wavelength selection router, and the uplink signal passes through the filter of the wavelength selection router to reach the optical splitter, and passes through the optical splitter to reach the wavelength selection.
  • the coupler, through the filter of the wavelength selective coupler, reaches the main kilofiber, passes through the main kilofiber to the wavelength division multiplexing coupler, and passes through the wavelength division multiplexing coupler to the OLT.
  • the optical network module selected in this embodiment may be implemented in the manner provided in Embodiment 2.
  • the wavelength division multiplexing coupler, the wavelength selective coupler and the wavelength selective router all use the same type of thin film filter, the film The filter reflects the signal of the optical path detection wavelength and transmits the signal of the non-optical detection wavelength. It will not be detailed here.
  • the optical path detection signal of the OTDR and the optical path detection reflection signal do not have any interference to the downlink and uplink optical links.
  • the communication between the OLT and the ONU of the passive optical network is always smooth, that is, their services are not interrupted. If a branch fiber fails, the user of other branch fibers will not be aware of the OTDR for detection and fault location, and subsequent repair and recovery of normal operation.
  • the above embodiments can monitor, detect, and locate faults of the primary and all branch fibers of the passive optical network, and select the branch fiber corresponding to the OTDR by selecting the signal wavelength of the OTDR. Measurement. This avoids the problem of overlapping and indistinguishable signals of equal-length branched fibers.
  • the optical path detection signal and the reflected signal of the OTDR are bypassed to the main optical fiber by the optical splitter, so that the loss of the optical splitter is independent of the optical path detection signal, which ensures the detection capability and accuracy of the OTDR for the branched optical fiber, and can be very effective. Help operators quickly locate faults, shorten maintenance time, and reduce maintenance costs.

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Abstract

本发明公开了一种无源光网络光纤故障的检测系统和方法。该系统包括：光程检测设备、波分复用耦合器、波长选择耦合器、分支光纤选择器和波长选择路由器，该检测系统是附属在原无源光网络系统上，在检测进行时不影响原系统的运行。根据本发明，解决了因光程检测反射信号被损耗而无法确定分支光纤是否存在故障的问题，同时能够对故障分支光纤进行快速定位及维修，降低了运营商的运行和维护成本。

Description

无源光网络光纤故障的检测系统和方法 技术领域 本发明涉及通信领域， 具体而言， 涉及一种无源光网络光纤故障的检测系 统和方法。 背景技术 网络技术的快速发展和网络应用的普及化， 如网络通讯和网络购物， 以及 网络娱乐等已经成为现代人生活的一部分， 现有的接入网络铜线 （有线） 系统 已远远满足不了这种高速和宽带的需求， 而无源光网络（PON, Passive Optical Network ) 具有宽带、 高速、 环保和节能特点， 是取代现有接入网络的最佳候 选者， 其正在被绝大多数运营商所接受并被部署， 用以满足日益增长的通信用 户以及更快速和更好的月艮务需求。 无源光网络是一种点对多点的光纤接入技术， 如图 1所示， 无源光网络包 括光线路终端（ OLT, Optical Line Terminal ),光网络单元（ ONU, Optical Network Unit ) 以及光分配网络 ( ODN, Optical Distribution Network ), 其通常由一个光 线路终端 OLT通过光分配网络 ODN的光功率分离器（简称分光器）连接多个 光网络单元 ONU构成的点到多点结构。 在大量无源光网络的安置和部署后， 需要考虑该网络的运行和维护， 特别 是光纤线路的检测和故障的定位。 为了降低运行和维修成本， 运营商希望在 OLT处用一个光程检测设备， 又称光时域反射计（OTDR, Optical Time Domain Reflectometer ) 来检测整个无源光网络的主千和分支光纤， 如果一个分支光纤 出现故障， 希望在不影响其它分支光纤的业务的情况下， 能迅速发现故障和对 故障进行定位以及维修。 在局方 OLT处用一个 OTDR来检测这种点到多点网络时， 可以比较准确 地检测到主千光纤是否正常， 但检测分支光纤的信号时将会遇到以下两个问 题。 一、 如果部分分支光纤到分光器的距离大致相等时， OTDR不能分辨到底 是哪个分支光纤的信号， 除非使用高分辨率的 OTDR, 但现在所能提供的最高 分辨率为 2米， 还是不能满足实际需求。 二、 如果分光器的分光比例很大， 这时分支光纤的瑞利反射信号经过分光 器时将有很大的损耗， 等该反射信号到达 OTDR时， 该反射信号和噪声信号混 合在一起， 难以分辨。 例如： 对于 1:32分光比的 10公里 ODN, 分光器的损耗是 3*5+3=18 dB; 而 10公里光纤损耗是 0.40* 10 = 4.0 dB。 一般 OTDR的最大动态范围是 40 dB 左右。 如 OTDR的信号经过分光器到达分支光纤的末端然后全反射 (即不计反 射损耗） 经过分光器到达 OTDR。 如果不计其它损耗 （如连接损耗等）， 这时 OTDR的信号全光程最大损耗将是 2* 18+2*4.0 = 44 dB。 这已经超出 OTDR的 工作动态范围， 因此分支光纤的信号已淹没在噪声中。 可见， 传统用在局方的 OTDR是不能测量大分光比的 ODN的分支光纤的故障。 这种现象比较普及， 在实际铺设的 PON网络中由于种种原因甚至对很小分光比的 PON, 用普通的 OTDR也不能看到分支光纤的反射信号。 针对上述问题， 现有的补 ¾办法是在所有的 ONU前加一个光滤波片， 见 图 2所示。该滤波片透射所有的波长为 1625nm以下的光，但反射波长为 1625nm 以上的 OTDR发射的光， 釆用光滤波片后， 端口反射的光可以增加 6 dB, 再 配上高分辨 OTDR, 就可以根据有没有反射光来确定分支光纤是否有故障， 但 是当分支光纤上有故障时， 因为该分支光纤上的反射光没有经过光滤波片增 强， 所以还是存在上述的反射光淹没在噪声中的现象， 因此不能确定分支光纤 故障发生的确切位置。 另外， 如果有部分分支光纤长度基本相等， 反射的光基 本重叠， 即使是高分辨 OTDR也不能分辨接收的反射光是哪路光纤分支的光。 更糟糕的是， 对于大分光比的 ODN (如： 1: 128 分光比以上）， 滤波片带来的 增益有可能还远远不够分光器的损耗， 因此在局方的 OTDR将有可能收不到来 自分支光纤的任何信息， 进而导致无法确定分支光纤是否存在故障， 以及故障 的具体位置。 发明内容 本发明的主要目的在于提供一种无源光网络光纤故障的检测系统和方法， 以解决上述的无法确定分支光纤故障的问题。 根据本发明的一个方面， 提供了一种无源光网络光纤故障的检测系统， 包 括： 光程检测设备 OTDR, 设置为发射与分支光纤对应波长的光程检测信号， 接收光程检测反射信号， 根据光程检测反射信号的状态确定主千光纤或分支光 纤是否存在故障； 波分复用耦合器，设置为将光程检测信号导入到主千光纤上， 以及将主千光纤传输的光程检测反射信号传输至 OTDR; 波长选择 合器， 设 置为将主千光纤上的光程检测信号传输至分支光纤选择器， 将接收到的来自分 支光纤选择器的光程检测反射信号导回到主千光纤上； 分支光纤选择器， 设置 为将光程检测信号传输至对应的波长选择路由器， 并将来自波长选择路由器的 光程检测反射信号传输至波长选择耦合器； 波长选择路由器， 通过分支光纤与 对应的光网络单元相连， 设置为将光程检测信号传输至光网络单元； 将分支光 纤上的光程检测反射信号传输至分支光纤选择器。 上述波分复用耦合器， 还设置为接收光线路终端的下行信号， 并将下行信 号导入到主千光纤上， 以及分离主千光纤传输的光程检测反射信号和上行信 号， 将上行信号传输至光线路终端； 波长选择耦合器， 还设置为分离主千光纤 传输的光程检测信号和下行信号， 将下行信号传输至分光器， 以及设置为接收 分光器传输的上行信号， 将上行信号传输至主千光纤上； 该系统还包括： 分光 器， 设置为将下行信号传输至所有的波长选择路由器， 以及接收每个波长选择 路由器传输的上行信号， 将上行信号传输至波长选择耦合器； 上述波长选择路 由器， 还设置为将下行信号传输至相连的光网络单元， 以及分离光网络单元的 上行信号和光程检测反射信号， 将分离出的上行信号传输至分光器。 上述波分复用耦合器为第一光滤波器， 第一光滤波器包括： 第一接口， 设 置为与光线路终端相连，传输上行信号和下行信号；第二接口，设置为与 OTDR 相连， 将光程检测信号传输至主千光纤， 将光程检测反射信号传输至 OTDR; 通用接口， 设置为与主千光纤相连。 上述波分选择耦合器为第二光滤波器， 第二光滤波器包括： 第一接口， 设 置为与分光器相连， 传输上行信号和下行信号； 第二接口， 设置为与分支光纤 选择器相连， 将光程检测信号传输至分支光纤选择器， 将光程检测反射信号传 输至主千光纤； 通用接口， 设置为与主千光纤相连。 上述分支光纤选择器为列阵波导光栅， 列阵波导光栅包括： 通用接口， 设 置为与波长选择 合器相连； 多个光栅分支进出口， 设置为与每个光纤分支上 的波长选择路由器相连， 以及用于根据光程检测信号的波长将光程检测信号传 输至对应的波长选择路由器。 上述波长选择路由器为第三光滤波器， 第三光滤波器包括： 第一接口， 设 置为与分光器相连， 传输上行信号和下行信号； 第二接口， 设置为与分支光纤 选择器相连， 接收光程检测信号， 以及将光程检测反射信号传输至分支光纤选 择器； 通用接口， 设置为通过分支光纤与光网络单元相连， 将第二接口接收的 光程检测信号传输至光网络单元， 以及接收来自分支光纤的光程检测反射信 号。 上述第一光滤波器、 第二光滤波器和第三光滤波器均为薄膜滤波器， 薄膜 滤波器反射光程检测波长的信号， 透射非光程检测波长的信号。 根据本发明的另一方面， 提供了一种无源光网络光纤故障的检测方法， 包 括： 光程检测设备 OTDR发射与分支光纤对应波长的光程检测信号； 波分复用 耦合器接收光程检测信号， 将光程检测信号通过主千光纤传输至波长选择 合 器； 波长选择耦合器通过分支光纤选择器将光程检测信号传输至对应的波长选 择路由器； 由对应的波长选择路由器通过分支光纤将光程检测信号传输至光网 络单元； 其中， 光程检测信号在传输的过程中产生光程检测反射信号， 光程检 测反射信号沿与光程检测信号相反的光路传输至 OTDR上； OTDR根据光程检 测反射信号的状态确定主千光纤或分支光纤是否存在故障。 上述波分复用耦合器接收光程检测信号的过程中还包括： 波分复用耦合器 接收光线路终端的下行信号， 并将下行信号导入到主千光纤上； 上述波长选择 耦合器通过分支光纤选择器将光程检测信号传输至对应的波长选择路由器包 括： 波长选择 合器分离主千光纤传输的光程检测信号和下行信号， 将下行信 号传输至分光器， 由分光器将下行信号传输至所有的波长选择路由器， 以及通 过分支光纤选择器将光程检测信号传输至光程检测信号的波长对应的波长选 择路由器上； 上述波长选择路由器通过分支光纤将光程检测信号传输至光网络 单元包括： 每个波长选择路由器通过所连接的分支光纤将下行信号传输至与其 连接的光网络单元。 该方法还包括： 波长选择路由器分离光网络单元的上行信号和光程检测反 射信号， 分离出的上行信号沿与下行信号相反的光路传输至光线路终端。 通过本发明， 使用波长选择耦合器将主千光纤上的光程检测信号转发至分 支光纤选择器， 而不是传输给分光器， 进而避免了分光器对光程检测信号的损 耗， 同时还通过波长选择路由器将分支光纤上的光程检测反射信号转发至分支 光纤选择器， 解决了因光程检测反射信号被损耗而无法确定分支光纤是否存在 故障的问题， 并能够对故障分支光纤进行快速定位及维修， 降低了运营商的运 行和维护成本。 附图说明 此处所说明的附图用来提供对本发明的进一步理解， 构成本申请的一部 分， 本发明的示意性实施例及其说明用于解释本发明， 并不构成对本发明的不 当限定。 在附图中： 图 1是根据相关技术的无源光网络的结构示意图； 图 2是根据相关技术的光程检测无源光网络系统的结构示意图； 图 3是才艮据本发明实施例 1和 2的无源光网络光纤故障的检测系统结构示 意图； 图 4是根据本发明实施例 2的波分复用耦合器的结构示意图 图 5是根据本发明实施例 2的波长选择耦合器的结构示意图 图 6是根据本发明实施例 2的分支光纤选择器的结构示意图 图 7是根据本发明实施例 2的波长选择路由器的结构示意图 图 8是根据本发明实施例 3的无源光网络光纤故障的检测方法流程图； 以 及 图 9是根据本发明实施例 4的无源光网络光纤故障的检测方法流程图 具体实施方式 下文中将参考附图并结合实施例来详细说明本发明。 需要说明的是， 在不 冲突的情况下， 本申请中的实施例及实施例中的特征可以相互组合。 本发明实施例的光网络系统包括光网络单元、 光分配网络和光线路终端， 其中， 系统中的各设备间通过光纤连接， 以下实施例以在该系统中实现为例进 行说明。 实施例 1 图 3示出了才艮据本发明实施例的无源光网络光纤故障的检测系统结构示意 图， 本实施例以三个光网络单元组成的无源光网络为例进行说明， 光网络单元 分别为第一光网络单元 102、 第二光网络单元 104和第三光网络单元 106; 该 系统还包括光分配网络 20和光线路终端 30; 本检测系统是在光线路终端 30处插入波分复用耦合器 42 , 用于连接光程 检测设备 OTDR40, 以及在光分配网络 20处， 插入三个光模块： 波长选择 合器 206、 分支光纤选择器 208和波长选择路由器， 其中， 波长选择路由器与 光网络单元是——对应的， 本实施例分别为第一波长选择路由器 210a、 第二波 长选择路由器 210b和第三波长选择路由器 210c。 上述各器件的特性和功能如下： 光程检测设备 OTDR 40, 设置为发射与分支光纤对应波长的光程检测信 号， 接收光程检测反射信号， 根据光程检测反射信号的状态确定主千光纤或分 支光纤是否存在故障； 波分复用耦合器 42 , 设置为将光程检测信号导入到主千光纤上， 以及将主 千光纤传输的光程检测反射信号传输至 OTDR40; 波长选择 合器 206 , 设置为将主千光纤上的光程检测信号传输至分支光 纤选择器 208 , 将接收到的来自分支光纤选择器 208的光程检测反射信号导回 到主千光纤上； 分支光纤选择器 208 , 设置为将上述光程检测信号传输至对应的波长选择 路由器， 并将来自波长选择路由器的光程检测反射信号传输至波长选择耦合器 206; 其中， 波长选择路由器与光网络单元是——对应的， 本实施例分别为第 一波长选择路由器 210a、 第二波长选择路由器 210b 和第三波长选择路由器 210c, 它们具有相同的功能， 本实施例上述对应的波长选择路由器以第一波长 选择路由器 210a为例进行说明； 第一波长选择路由器 210a, 通过分支光纤与第一光网络单元 102相连， 设 置为将上述光程检测信号传输至第一光网络单元 102; 将分支光纤上的光程检 测反射信号传输至分支光纤选择器 208。 上述波分复用耦合器 42 ,波长选择耦合器 206以及波长选择路由器（ 210a,
210b和 210c ), 可以均为薄膜滤波器， 例如均为边带类型的薄膜滤波器， 如果 选择光程检测波长在 U波段， 即 1625nm到 1675nm, 那么该薄膜滤波器将选 择为边带滤波器， 即反射波长在 1625纳米以上的信号， 透射波长在 1625纳米 以下的信号， 同时分支光纤选择器中的列阵波导光栅也将选择工作在 U波段； 如果选择光程检测波长在 C波段， 即 1528nm到 1560nm, 那么该薄膜滤波器 将选择为宽带滤波器，即反射波长在 C波段的信号，透射波长非 C波段的信号， 同时分支光纤选择器中的列阵波导光栅也将选择工作在 C波段。 图 3所示的检测系统中的波长选择耦合器 206和波长选择路由器（第一波 长选择路由器 210a、 第二波长选择路由器 210b和第三波长选择路由器 210c ) 之间设置有分光器 212 , 该分光器 212和该分光器 212与其他设备相连的连线 用虚线表示， 用以说明其不传输光程检测信号和光程检测反射信号， 仅用于传 输上行信号和下行信号。 其中， OTDR 40为光波长可调谐的设备， 可以根据要检测的分支光纤调整 OTDR 40发射的相应的光程检测信号的波长，使不同波长的光程检测信号沿不 同的分支光纤传输， 进而达到检测该分支光纤是否故障的目的。 本实施例中， 虽然每个分支光纤都有与其相连的波长选择路由器， 但并不 是每个波长选择路由器都传输光程检测信号， 本实施例通过分支光纤选择器选 择与光程检测信号的波长对应的波长选择路由器传输光程检测信号， 其它的波 长选择路由器没有光程检测信号传输， 本实施例的分支光纤选择器可以通过与 其波长不对应通道会对该波长的光有巨大损耗而关闭其通道。 本实施例通过使用波长选择耦合器 206将主千光纤上的光程检测信号转发 至分支光纤选择器 208, 而不是传输给分光器， 进而避免了分光器对光程检测 信号的损耗， 同时还通过波长选择路由器将分支光纤上的光程检测反射信号转 发至分支光纤选择器 208, 避免了光程检测反射信号经分光器后带来了损耗， 因此最大限度地保证了光程检测反射信号的强度， 解决了因光程检测反射信号 被损耗而无法确定分支光纤是否存在故障的问题， 并且还能够根据光程检测反 射信号发生异常的时刻确定出故障的具体位置。 实施例 2 上述实施例 1 中图 3 所示的检测系统可以附属在原有的无源光网络系统 上， 在检测光纤故障进行时不影响原有系统的运行， 下面仍以图 3所示的无源 光网络光纤故障的检测系统为例进行说明， 本实施例主要对光程检测信号和通 讯信号的运行过程进行全面描述。 由图 3所示可知， 该系统包括： 波长可调谐的 OTDR 40、 波分复用耦合器 42、 波长选择耦合器 206、 分支光纤选择器 208以及一个以上与分光器 212相 连的波长选择路由器， 本实施例分别为第一波长选择路由器 210a、 第二波长选 择路由器 210b和第三波长选择路由器 210c。 其中， 波分复用耦合器 42与 OTDR 40以及光线路终端 30相连； 通过主 千光纤与波长选择耦合器 206相连； 波长选择耦合器 206与分光器 212以及分支光纤选择器 208相连； 分支光纤选择器 208与每个波长选择路由器相连， 即与本实施例的第一波 长选择路由器 210a、 第二波长选择路由器 210b 和第三波长选择路由器 210c 相连； 每个波长选择路由器分别通过相应的分支光纤与光网络单元相连， 本实施 例的光网络单元分别为第一光网络单元 102、 第二光网络单元 104和第三光网 络单元 106; 如图 3所示， 第一波长选择路由器 210a通过第一分支光纤与第一 光网络单元 102相连； 第二波长选择路由器 210b通过第二分支光纤与第二光 网络单元 104相连， 第三波长选择路由器 210c通过第三分支光纤与第三光网 络单元 106相连。 OTDR 40, 设置为向波分复用耦合器 42发射针对相应分支光纤的特定波 长的光程检测信号， 并根据分析收到光程检测反射信号是否异常来确定主千光 纤和相应分支光纤是否存在故障。 光程检测反射信号可以是菲涅尔反射信号或者瑞利反射信号， 当该信号有 突变， 可以确定主千光纤或相应分支光纤是否存在故障， 可根据突变的时刻和 信号的传输速度确定故障的具体位置。 波分复用耦合器 42 , 设置为将收到的光程检测信号和光线路终端 （ OLT ) 30的下行信号导入到主千光纤上，以及将主千光纤上分离出来的光程检测反射 信号传输至 OTDR40上， 并将分离出的上行信号传输至光线路终端 30。 波长选择 合器 206 ,设置为从主千光纤下行信号中分离出光程检测信号， 并将其传输至分支光纤选择器 208; 其余的下行信号传输至分光器 212; 以及 将收到的来自分支光纤选择器 208的光程检测反射信号导回到主千光纤上， 同 时将通过分光器 212的上行信号传送到主千光纤上。 分支光纤选择器 208 , 设置为根据光程检测信号的波长将光程检测信号导 向与其相关的出口， 进入与其相连的波长选择路由器上， 并将来自波长选择路 由器的分支光纤的光程检测反射信号传输至波长选择耦合器 206; 本实施例以 将光程检测信号传输至第一波长选择路由器 210a为例进行说明。 分光器 212 , 设置为将上述下行信号传输至所有的与其相连的波长选择路 由器， 以及接收所有的波长选择路由器传输的上行信号， 将上行信号传输至波 长选择耦合器 206。 波长选择路由器（即本实施例的第一波长选择路由器 210a、 第二波长选择 路由器 210b和第三波长选择路由器 210c ),设置为将来自分光器 212的下行信 号传给分支光纤， 其中， 本实施例的第二波长选择路由器 210b 和第三波长选 择路由器 210c还用于将分支光纤上的上行信号传输至分光器 212; 第一波长选 择路由器 210a还用于从分支光纤的上行信号中分离出光程检测反射信号传输 至分支光纤选择器 208, 以及将其余分离出的上行信号传输至分光器 212。 为了在不影响正常业务时， 将光程检测信号导入和导出， 本实施例将波分 复用 合器 42设置于局方光线路终端 30处。 参见图 4所示， 波分复用耦合器 42可以由一个薄膜滤波器 （ TFF ) 组成。 该薄膜滤波器可以对光程检测波长的光均反射， 但对非光程检测波长的光均透 射。 该薄膜滤波器包括： 第一接口 （用" P"表示）， 设置为与光线路终端 30 相 连， 传输（透射） 上行信号和下行信号， 本实施例的上行信号和下行信号的波 长均小于光程检测信号的波长； 第二接口 （用" R"表示）， 设置为与 OTDR40相连， 将光程检测信号传输至 主千光纤， 将光程检测反射信号传输至 OTDR 40; 通用接口 （用" C"表示）， 设置为与主千光纤相连。 该薄膜滤波器用于将 OTDR 40输出的光程检测信号导入到主千光纤上， 并将光程检测反射信号传输至 OTDR 40, 同时保持光线路终端 30与光网络单 元的正常上下行信号的通讯往来。 在本发明实施例中， 将波长选择耦合器 206设置在分光器 212的入口处， 参见图 5所示， 波长选择耦合器 206可以由一个薄膜滤波器 （TFF ) 组成。 该 薄膜滤波器对光程检测波长的光均反射， 但对非光程检测波长的光均透射。 该薄膜滤波器包括： 第一接口 （用" P"表示）， 设置为与分光器 212相连， 传输上行信号和下行信号， 本实施例的上行信号和下行信号的波长可以均小于 光程检测信号的波长； 第二接口 （用" R"表示）， 设置为与分支光纤选择器 208相连， 将光程检测 信号传输至分支光纤选择器 208 , 将光程检测反射信号传输至主千光纤； 通用接口 （用" C"表示）， 设置为与主千光纤相连。 该薄膜滤波器用于将光程检测信号导入到分支光纤选择器上， 并将分支光 纤的光程检测反射信号导回主千光纤上， 同时保持光线路终端 30 与光网络单 元的正常上下行信号的通讯往来。 在光分配网络 20的分光器 212旁设置一个分支光纤选择器 208,分支光纤 选择器 208是个无源器件。 参见图 6所示， 分支光纤选择器 208是由列阵波导 光栅 ( AWG, Arrayed Waveguide Gratings ) 组成。 该列阵波导光栅包括： 通用接口 （用" C"表示）， 设置为与波长选择 合器 206相连； 多个光栅分支进出口 （用" 1至 N"表示）， 设置为与每个光纤分支上的波长 选择路由器相连， 以及用于根据光程检测信号的波长将光程检测信号传输至对 应的波长选择路由器。 为了使分支光纤选择器 208做到真正的无源，应使 AWG与环境温度无关， 即环境温度的变化如 -20°C至 60 °C对 AWG工作参数和性能没有影响， 否则 AWG需要一个温控设备来保持其工作稳定。 AWG的工作波长范围的选择与客 户所用的 OTDR的调谐范围有关， 为了减少对 PON工作的千 4尤， 因此其波长 需要避开上下行波长的波段， 根据 ITU-T L.66的 OTDR波长的规定， 通常其 工作波长范围在 U波段， 即 1625 nm至 1675nm。如有需要也可以选择 C波段， 或其他波段， 只要避开无源光网络正常工作波段即可， 在这种情况下， 上述滤 波器和 OTDR也要作相应的调整。 AWG的通道间隔一般为 100GHz, 根据需 要也可选择 50GHz的间隔的 AWG。 其通道数的选择应与分光器 212的分光数 相对应， 如 1 :32的分光比的 ODN就要配上 32个通道的 AWG。 其基本工作原 理是不同波长的光信号在 AWG中走不同的通道， 而其通道通过波长选择路由 器与分支光纤相连， 这样分支光纤被 OTDR的光程检测信号的波长标识了， 即 不同波长的光程检测信号检测其相对应的分支光纤。 本实施例在分光器 212的每一个分支光纤前连一个波长选择路由器， 参见 图 7所示， 本实施例的波长选择路由器可以由一个薄膜滤波器 （TFF ) 组成。 该薄膜滤波器对 1625nm ( OTDR的波长）以上的光均反射， 但对 1625nm以下 的光均透射。 该薄膜滤波器包括： 第一接口 （用" P"表示）， 设置为与分光器 212相连， 传输上行信号和下行信号， 本实施例的上行信号和下行信号的波长可以均小于 光程检测信号的波长； 第二接口 （用" R"表示）， 设置为与分支光纤选择器 208相连， 接收光程检 测信号， 以及将光程检测反射信号传输至分支光纤选择器 208; 通用接口 （用" C"表示）， 设置为通过分支光纤与光网络单元相连， 将第二 接口接收的光程检测信号传输至光网络单元， 以及接收来自分支光纤的光程检 测反射信号。 该薄膜滤波器用于将来自分支光纤选择器 208上的光程检测信号导入到分 支光纤上， 并将分支光纤的光程检测反射信号导回分支光纤选择器 208上， 同 时保持光线路终端 30与光网络单元的正常上下行信号的通讯往来。 上述波分复用耦合器 42 ,波长选择耦合器 206以及波长选择路由器（210a、 210b和 210c ),均使用同一种类型的薄膜滤波器，该薄膜滤波器反射波长在 1625 纳米以上的信号， 透射波长在 1625 纳米以下的信号。 这种选择方式简化了系 统的设计， 降低了成本。 本实施例通过以上一系列辅助光功能模块组成的光程检测系统， 可以在局 方用一个可调 i皆的 OTDR来智能地、快速地检测和定位主千光纤和任何一支分 支光纤的故障。 而且通过选择不同波长的光程检测信号来检测与其相关的分支 光纤， 这样就避免了长度相等分支光纤的信号重叠， 不能区分。 同时让光程检 测信号和光程检测反射信号均绕过分光器回到主千光纤， 这样就避免了分光器 对光程检测信号和光程检测反射信号的衰减，保证了 OTDR能够接收到其光程 检测反射信号。 实施例 3 图 8示出了才艮据本发明实施例的无源光网络光纤故障的检测方法流程图， 该方法以在图 3所示的系统上实现为例进行说明， 该方法包括： 步骤 S802: 光程检测设备 OTDR发射与分支光纤对应波长的光程检测信 号； 步骤 S804: 波分复用耦合器接收上述光程检测信号， 将光程检测信号通过 主千光纤传输至波长选择耦合器； 步骤 S806:波长选择耦合器通过分支光纤选择器将光程检测信号传输至对 应的波长选择路由器； 由对应的波长选择路由器通过分支光纤将光程检测信号 传输至光网络单元； 其中， 上述光程检测信号在传输的过程中产生光程检测反射信号， 光程检 测反射信号沿与光程检测信号相反的光路传输至 OTDR上； 其中， 相反的光路 指传输经过的光器件相同， 但传输方向相反。 步骤 S808: OTDR根据光程检测反射信号的状态确定主千光纤或分支光纤 是否存在故障。 本实施例选择的光网络模块可以釆用实施例 2中提供的方式实现， 例如上 述波分复用耦合器， 波长选择耦合器以及波长选择路由器， 均使用同一种类型 的薄膜滤波器， 该薄膜滤波器反射光程检测波长的信号， 透射非光程检测波长 的信号。 这里不再详述。 本实施例通过使用波长选择耦合器将主千光纤上的光程检测信号转发至 分支光纤选择器， 而不是传输给分光器， 进而避免了分光器对光程检测信号的 损耗， 同时还通过波长选择路由器将分支光纤上的光程检测反射信号转发至分 支光纤选择器， 避免了光程检测反射信号经分光器后带来了损耗， 因此最大限 度地保证了光程检测反射信号的强度， 解决了因光程检测反射信号被损耗而无 法确定分支光纤是否存在故障的问题， 并且还能够根据光程检测反射信号发生 异常的时刻确定出故障的具体位置。 实施例 4 为了实现智能地检测无源光网络的光纤系统， 首先对无源光网络做一些改 造， 增加一些无源的光功能模块。 本实施例按照图 3的方式， 在光线路终端处 增加了一个波分复用耦合器， 它的主要功能是把 OTDR连接在主千光纤上， 使 得光程检测信号（即 OTDR发射的信号）能进入无源光网络系统， 相应的光程 检测反射信号能通过网络传到 OTDR上。 在分光器前插入波长选择耦合器，它的主要功能是把 OTDR发射的光程检 测信号从主千光纤中分离出来传给分支光纤选择器， 以及把分支光纤的光程检 测反射信号传回主千光纤。 同时它保证上下行信号的正常通讯。 在分光器后每个分支光纤前插入波长选择路由器， 它的主要功能是把来自 分支光纤选择器上的光程检测信号导入到分支光纤上， 以及把分支光纤的光程 检测反射信号从上行信号中分离出来传到分支光纤选择器上， 同时保证上下行 通讯正常运行。 在分光器旁放上分支光纤选择器， 见图 6所示， 它的一端与波长选择 合 器相连， 另一端与每个波长选择路由器相连。 它的主要功能是根据光程检测信 号的波长通过 AWG分路， 巴光程检测信号导向与其相应的波长选择路由器及 分支光纤上， 以及将选择的分支光纤的光程检测反射信号通过与其相连的波长 选择路由器把它从上行信号中分离出来， 进入与其相连的 AWG光栅接口， 经 AWG导向波长选择耦合器上。 当所有这些模块按图 3所示结构连接后， OTDR就能智能地测试整个无源 光网络系统， 下面以图 3所示系统对整个光程检测流程进行说明， 参见图 9, 无源光网络光纤故障的检测方法包括以下步骤： 步骤 S902: 根据需要测量的分支光纤调整 OTDR 的检测信号的波长， OTDR按照调整后的波长发射光程检测信号； 当无源光网络需要检测时， 首先在局方把 OTDR连在波分复用耦合器上， 然后 4十对一个所需测量分支光纤， 选定其所对应的光程检测波长， OTDR^巴检 测信号的波长调到该波长上， 如果是 U波段， 其波长范围一般在 1625纳米至 1675纳米之间， 如果是 C波段， 其波长范围一般在 1528纳米至 1560纳米之 间。 这里需要说明的是， 当分支光纤选择器的安置结束后， 其 AWG的光栅接 口与分支光纤的关系也就固定下来了， 而不同的光栅接口对应不同的波长进 出， 因此分支光纤被光波长进行了标识， 对不同的分支光纤检测需要选用其对 应的波长进行。 当 OTDR调到所要测量分支光纤所对应的波长后，用该波长发出光程检测 信号。 步骤 S904: 光程检测信号通过与 OTDR连接的波分复用 合器的 R接口 被 合进主千光纤进行传输， 其反射信号 （即光程检测反射信号）将原路返回 到 OTDR上； 步骤 S906: 光程检测信号通过主千光纤传输到波长选择耦合器的 C接口， 然后被分离出来从 R接口输出到分支光纤选择器 （即 AWG ) 的通用接口； 步骤 S908:分支光纤选择器 居光程检测信号的波长将其导入到相应的光 栅出口， 并进入与该光栅出口相连的波长选择路由器的 R接口； 步骤 S910: 光程检测信号从波长选择路由器的 C接口输出到与其相连的 分支光纤， 经传输到达与该 C接口相连的光网络单元 ONU。 上述主千光纤有任何故障， 光程检测发射信号将会出现反常信号， 该信号 将很快被 OTDR发现， 并且能迅速定位。 上述主千光纤没有问题， 光程检测信号将一直传输到波长选择耦合器的 C 接口， 然后被分离出来从 R接口输出到分支光纤选择器的 AWG的通用接口， 接着 居光程检测信号的波长被导入到其相应的光栅出口， 进入与其相连的波 长选择路由器的 R接口，接着从其 C接口输出到与其相连的分支光纤， 经传输 到达与其相连的 ONU。 上述光程检测信号的反射信号 （即光程检测反射信号） 沿与其相反的光路 返回，即通过波长选择路由器的 R接口到 C接口，到达分支光纤选择器的 AWG 的光栅分支进出口， 出 AWG的通用接口进入与其相连的波长选择耦合器的 R 接口， 然后由 C接口输出， 进入主千光纤， 经主千光纤的传输到达波分复用耦 合器的 C接口，然后被分离从其 R接口输出返回到 OTDR上，所以每次 OTDR 上将展示一个主千光纤加一个分支光纤的光程检测反射信号。 步骤 S912: 才艮据 OTDR上光程检测反射信号的状态确定主千光纤或分支 光纤是否存在故障。 如果要检测其它的分支光纤， 则需要重复以上的步骤， 即把 OTDR发射的 光波长调到与分支光纤对应的波长， 然后发出光程检测信号， OTDR将收到对 应的光程检测反射信号， 根据该光程检测反射信号是否异常即可判断其是否有 故障， 以及对故障进行定位。 重复以上的步 4聚一直到测量结束。 在检测过程中 OLT与 ONU之间的通讯仍可以保持正常状态。 以图 3所示 系统结构为例， 对于下行光链路， 在检测过程中， 下行信号的转发过程如下： 光线路终端 OLT发出下行信号， 波分复用耦合器接收光线路终端的下行信号， 并将下行信号导入到主千光纤上； 波长选择 合器分离主千光纤传输的光程检测信号和下行信号， 将下行信 号传输至分光器， 由分光器将下行信号传输至所有的波长选择路由器， 以及通 过分支光纤选择器将光程检测信号传输至光程检测信号的信号波长对应的波 长选择路由器上； 波长选择路由器通过所连接的分支光纤将下行信号传输至与其连接的光 网络单元； 分支光纤的光程检测反射信号通过波长选择路由器沿光程检测信号 的相反光路传输至 OTDR上。 上述光线路终端 OLT发出的下行信号， 经过波分复用耦合器的透射， 穿过 主千光纤到达波长选择 合器， 然后透过滤波片到达分光器， 经过分光器的分 光到达每个波长选择路由器， 穿过波长选择路由器上的滤波片到达每个分支光 纤， 然后通过分支光纤到达相应的 ONU。 对于上行光链路， 其上行信号转发过程如下： 由 ONU发出的上行信号， 穿过分支光纤到达波长选择路由器， 上行信号 透过波长选择路由器的滤波片到达分光器， 穿过分光器到达波长选择耦合器， 透过波长选择耦合器的滤波器到达主千光纤， 穿过主千光纤到达波分复用耦合 器， 透过波分复用耦合器到达 OLT处。 本实施例选择的光网络模块可以釆用实施例 2中提供的方式实现， 例如上 述波分复用耦合器， 波长选择耦合器以及波长选择路由器， 均使用同一种类型 的薄膜滤波器， 该薄膜滤波器反射光程检测波长的信号， 透射非光程检测波长 的信号。 这里不再详述。 在整个传输过程中， OTDR的光程检测信号以及光程检测反射信号没有对 下行和上行光链路有任何千扰。 在整个光程检测从开始到关闭的过程中， 无源 光网络的 OLT与 ONU之间的通讯始终保持畅通，也就是它们的业务没有中断。 如果有一个分支光纤发生故障， 在局方用 OTDR进行检测和故障定位， 以及后 继的修复及恢复正常工作状态过程中， 其他分支光纤的用户将不会有所感知。 这将大大降低了运营商的维修的成本。 以上实施例可以监视、 检测以及定位无源光网络的主千和所有的分支光纤 的故障， 而且通过选择 OTDR 的信号波长来选择与其对应的分支光纤进行检 测。 这样就避免了长度相等分支光纤的信号重叠、 不能区分的问题。 同时让 OTDR的光程检测信号和反射信号均绕过分光器回到主千光纤， 这样分光器的 损耗与光程检测信号无关， 保证了 OTDR对分支光纤的检测能力和精度， 能非 常有效地帮助运营商快速发现故障的位置，缩短了维爹的时间， 降氏维护成本。 特别是某个分支光纤发生故障时， 运营商可以在不影响其他分支光纤的正常业 务时， 对该分支光纤进行快速地检测和故障定位， 以及进行维修， 降低了运营 商的运行和维护成本。 以上所述仅为本发明的优选实施例而已， 并不用于限制本发明， 对于本领 域的技术人员来说， 本发明可以有各种更改和变化。 凡在本发明的 ^"神和原则 之内， 所作的任何修改、 等同替换、 改进等， 均应包含在本发明的保护范围之 内。

Claims

权 利 要 求 书
1. 一种无源光网络光纤故障的检测系统， 包括：
光程检测设备 OTDR, 设置为发射与分支光纤对应波长的光程检测 信号， 接收光程检测反射信号， 根据所述光程检测反射信号的状态确定 主千光纤或所述分支光纤是否存在故障；
波分复用耦合器， 设置为将所述光程检测信号导入到所述主千光纤 上， 以及将所述主千光纤传输的光程检测反射信号传输至所述 OTDR; 波长选择 合器， 设置为将所述主千光纤上的光程检测信号传输至 分支光纤选择器， 将接收到的来自所述分支光纤选择器的光程检测反射 信号导回到所述主千光纤上； 分支光纤选择器， 设置为将所述光程检测信号传输至对应的波长选 择路由器， 并将来自所述波长选择路由器的光程检测反射信号传输至所 述波长选择耦合器；
波长选择路由器， 通过分支光纤与对应的光网络单元相连， 设置为 将所述光程检测信号传输至所述光网络单元； 将所述分支光纤上的光程 检测反射信号传输至所述分支光纤选择器。
2. 根据权利要求 1所述的系统， 其中，
所述波分复用耦合器， 还设置为接收光线路终端的下行信号， 并将 所述下行信号导入到所述主千光纤上， 以及分离所述主千光纤传输的光 程检测反射信号和上行信号， 将所述上行信号传输至所述光线路终端； 所述波长选择耦合器， 还设置为分离所述主千光纤传输的所述光程 检测信号和所述下行信号， 将所述下行信号传输至分光器， 以及设置为 接收所述分光器传输的上行信号， 将所述上行信号传输至所述主千光纤 上；
所述系统还包括： 所述分光器， 设置为将所述下行信号传输至所有 的波长选择路由器，以及接收每个波长选择路由器传输的所述上行信号， 将所述上行信号传输至所述波长选择耦合器； 所述波长选择路由器， 还设置为将所述下行信号传输至相连的光网 络单元， 以及分离所述光网络单元的上行信号和光程检测反射信号， 将 分离出的上行信号传输至所述分光器。
3. 根据权利要求 2所述的系统， 其中， 所述波分复用耦合器为第一光滤波 器， 所述第一光滤波器包括：
第一接口， 设置为与所述光线路终端相连， 传输所述上行信号和所 述下行信号；
第二接口， 设置为与所述 OTDR相连， 将所述光程检测信号传输至 所述主千光纤， 将所述光程检测反射信号传输至所述 OTDR;
通用接口， 设置为与所述主千光纤相连。
4. 根据权利要求 2所述的系统， 其中， 所述波分选择 合器为第二光滤波 器， 所述第二光滤波器包括：
第一接口， 设置为与所述分光器相连， 传输所述上行信号和所述下 行信号；
第二接口， 设置为与所述分支光纤选择器相连， 将所述光程检测信 号传输至所述分支光纤选择器， 将所述光程检测反射信号传输至所述主 千光纤；
通用接口， 设置为与所述主千光纤相连。
5. 根据权利要求 1或 2所述的系统， 其中， 所述分支光纤选择器为列阵波 导光栅， 所述列阵波导光栅包括：
通用接口， 设置为与所述波长选择耦合器相连；
多个光栅分支进出口， 设置为与每个光纤分支上的波长选择路由器 相连， 以及用于根据所述光程检测信号的波长将所述光程检测信号传输 至对应的波长选择路由器。
6. 根据权利要求 2所述的系统， 其中， 所述波长选择路由器为第三光滤波 器， 所述第三光滤波器包括：
第一接口， 设置为与所述分光器相连， 传输所述上行信号和所述下 行信号； 第二接口， 设置为与所述分支光纤选择器相连， 接收所述光程检测 信号， 以及将所述光程检测反射信号传输至所述分支光纤选择器；
通用接口， 设置为通过所述分支光纤与所述光网络单元相连， 将所 述第二接口接收的光程检测信号传输至所述光网络单元， 以及接收来自 所述分支光纤的光程检测反射信号。 根据权利要求 3、 4、 6中任一项所述的系统， 其中， 所述第一光滤波器、 第二光滤波器和第三光滤波器均为薄膜滤波器， 所述薄膜滤波器反射光 程检测波长的信号， 透射非光程检测波长的信号。 一种无源光网络光纤故障的检测方法， 包括：
光程检测设备 OTDR发射与分支光纤对应波长的光程检测信号； 波分复用耦合器接收所述光程检测信号， 将所述光程检测信号通过 主千光纤传输至波长选择耦合器；
所述波长选择耦合器通过分支光纤选择器将所述光程检测信号传输 至对应的波长选择路由器； 由所述对应的波长选择路由器通过分支光纤 将所述光程检测信号传输至光网络单元；
其中， 所述光程检测信号在传输的过程中产生光程检测反射信号， 所述光程检测反射信号沿与所述光程检测信号相反的光路传输至所述 OTDR上；
所述 OTDR根据所述光程检测反射信号的状态确定主千光纤或所述 分支光纤是否存在故障。 根据权利要求 8所述的方法， 其中，
所述波分复用耦合器接收所述光程检测信号的过程中还包括： 所述 波分复用耦合器接收光线路终端的下行信号， 并将所述下行信号导入到 所述主千光纤上；
所述波长选择耦合器通过分支光纤选择器将所述光程检测信号传输 至对应的波长选择路由器包括： 所述波长选择耦合器分离所述主千光纤 传输的所述光程检测信号和所述下行信号， 将所述下行信号传输至分光 器， 由所述分光器将所述下行信号传输至所有的波长选择路由器， 以及 通过分支光纤选择器将所述光程检测信号传输至所述光程检测信号的波 长对应的波长选择路由器上； 所述波长选择路由器通过分支光纤将所述光程检测信号传输至光网 络单元包括： 所述波长选择路由器通过所连接的分支光纤将所述下行信 号传输至与其连接的光网络单元。
10. 才艮据权利要求 9所述的方法， 其中， 所述方法还包括：
所述波长选择路由器分离所述光网络单元的上行信号和光程检测反 射信号， 分离出的上行信号沿与所述下行信号相反的光路传输至所述光 线路终端。
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CA2809318C (en) 2017-07-25
EP2611047A4 (en) 2014-05-28
CN101924590B (zh) 2016-04-13
US20130148109A1 (en) 2013-06-13
EP2611047A1 (en) 2013-07-03
US9036138B2 (en) 2015-05-19

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