WO2011153840A1 - Method and apparatus for achieving optical line detection in long reach passive optical network - Google Patents

Abstract

The present invention provides a method and an apparatus for achieving optical line detection in a long reach Passive Optical Network (PON). The present invention divides, with a reach extender box as a boundary, a detection path into two paths: a trunk optical fiber and a branch optical fiber, and respectively detects the optical lines of the trunk optical fiber and the branch optical fiber. The method of the present invention overcomes the block for the Optical Time Domain Reflectometer (OTDR) signals performed by the reach extender box, at the same time compensates the extra optical loss due to the long distance optical fiber, and thus satisfies the requirements for performing the optical line detection for the whole long reach PON.

Description

 Method and device for realizing optical line detection in long-distance passive optical network

 The present invention relates to an optical network system, and more particularly to a method and apparatus for implementing optical line detection in a long-range passive optical network (PON, Passive Optical Network). Background technique

 The rapid development and low-cost demand for wired broadband access technology has promoted the gradual replacement of existing copper (wired) systems by the use of optical fibers, that is, the optical advancement of copper has become a trend. At the same time, passive optical networks have the widest, fastest and most environmentally friendly features. Long-haul passive optical networks have the characteristics of flattening and simplifying the network, as well as adapting to long-distance network structures and reducing investment costs. Passive optical networks are being accepted by most operators and are beginning to be deployed or ready to be deployed to meet the growing demand for communication users and faster and better service requirements.

 Long-distance PON is a point-to-multipoint fiber access technology. 1 is a schematic structural diagram of a conventional long-distance passive optical network, as shown in FIG. 1, including an optical line terminal (OLT, Optical Line Terminal), an optical network unit (ONU), and an optical distribution network (ODN). , Optical Distribution Network ). Generally, an OLT is connected to a plurality of ONUs through an ODN extension box (Rebox, Reach Extender Box, also known as a long-distance box) and an optical power splitter (referred to as a splitter), as shown in FIG. Shown.

Since the extension box of the long-distance PON has the function of blocking the optical time domain reflectometer (OTDR) signal and the additional optical loss caused by the long-range optical fiber, the existing optical line detection scheme for the PON is The method of using an OTDR light source or instrument to quickly detect the entire PON at one time is not suitable for long-distance passive optical networks. That is, the original detection method needs to be adjusted to achieve the entire long-distance PON. Perform optical line detection. Summary of the invention

 In view of the above, the main object of the present invention is to provide a method and a device for implementing optical line detection in a long-range passive optical network, which can overcome the blocking of the OTDR signal by the extension box and compensate for the additional optical loss caused by the long-range optical fiber. Thereby meeting the optical line detection requirements of long-distance PON.

 In order to achieve the above object, the technical solution of the present invention is achieved as follows:

 The invention provides a method for realizing optical line detection in a long-range passive optical network (PON), comprising:

 The extension box connects the trunk fiber and the branch fiber by:

 Placing a light guiding module between the extension box and the optical splitter for providing an interface for introducing a test signal; or

 A light guiding module is disposed before and after the extension box, and the test signal is introduced into the beam splitter and the subsequent branch fiber, and the test reflection signal from the branch fiber is coupled to the trunk fiber through the light guiding module; or

 A light guiding module is disposed between the extension box and the optical splitter, the light guiding module is connected to the testing module, and the testing module is connected to the data processing module;

 Optical line detection of trunk fibers and/or branch fibers.

 The optical light guiding module is disposed between the extension box and the optical splitter to provide an interface for introducing a test signal, specifically: the light guiding module is a wavelength division multiplexing filter, and the extension box and the wavelength division multiplexing filter are The branch interface is connected, the optical splitter is connected to the universal interface of the wavelength division multiplexing filter, and the other branch interface of the wavelength division multiplexing filter is used as the connection port of the test module;

 Correspondingly, the optical line detection is performed on the trunk fiber and the branch fiber respectively: the test module is used to detect the light path of the branch fiber behind the extended box from the interface of the test module.

The light guide module is placed before and after the extension box, and the test signal is introduced into the beam splitter and the subsequent branch fiber, and the test reflection signal from the branch fiber is coupled to the trunk fiber through the light guide module. Specifically:

 The light guiding module is composed of a first wavelength division multiplexing filter, a second wavelength division multiplexing filter and an optical circulator; a common interface of the first wavelength division multiplexing filter is connected to a trunk optical fiber, and the first wavelength division One end of the first branch interface extension box of the multiplexing filter is connected, and the second branch interface of the first wavelength division multiplexing filter is connected to the optical circulator; the common interface and the optical splitter of the second wavelength division multiplexing filter Connecting, the first branch interface of the second wavelength division multiplexing filter is connected to the other end of the extension box, and the second branch interface of the second wavelength division multiplexing filter is connected to the optical circulator; the optical circulator is also connected to the test module ;

 Correspondingly, the optical line detection of the trunk fiber and the branch fiber respectively is:

 The test module is controlled by the OLT through the extension box, and the signal of the test module is coupled to the optical splitter; the light reflection signal of the test module bypasses the extension box and enters the trunk fiber, and then is transmitted to the test module at the OLT.

 The light guide module is disposed between the extension box and the optical splitter, and the light guide module is connected to the test module, and the test module is connected to the data processing module, where the light guide module is a wavelength division multiplexing filter, and the wave is The common interface of the multiplex filter is connected to the optical splitter, the first branch interface of the WDM filter is connected to the extension box, and the second branch interface of the WDM filter is connected to the test module;

 Correspondingly, the optical line detection of the trunk fiber and the branch fiber respectively is:

 The OLT controls the test module through the extension box, and the signal of the test module is coupled to the optical splitter. The reflected signal of the test module is returned to the test module and processed, and then transmitted back to the OLT through the extension box.

 The method further includes: at the OLT, coupling the signal of the test module into the optical fiber by using a test module at the OLT to complete optical line detection of the backbone optical fiber between the OLT and the extension box.

The invention also provides a device for realizing optical line detection in a long-distance passive optical network (PON), comprising at least an extension box, a test module disposed near the extension box, and being disposed at the OLT Test module, where

 The extension box connects the trunk fiber and the branch fiber by:

 Placing a light guiding module between the extension box and the optical splitter for providing an interface for introducing a test signal; or

 A light guiding module is disposed before and after the extension box, and the test signal is introduced into the beam splitter and the subsequent branch fiber, and the test reflection signal from the branch fiber is coupled to the trunk fiber through the light guiding module; or

 A light guiding module is disposed between the extension box and the optical splitter, the light guiding module is connected to the testing module, and the testing module is connected to the data processing module;

 A test module is provided at the OLT for optical line detection of the backbone fiber.

 In the case where a light guiding module is disposed between the extension box and the optical splitter for providing an interface for introducing a test signal, the light guiding module is a wavelength division multiplexing filter, a signal for coupling the test module, and a test is to be performed. The reflected signal of the module is separated from the main signal stream;

 a general interface of the wavelength division multiplexing filter is connected to the optical splitter, a first branch interface of the wavelength division multiplexing filter is connected to the extension box, and a second branch interface of the wavelength division multiplexing filter is used as The connection port of the test module.

 In the case where the light guiding module is placed before and after the extension box, the light guiding module is composed of a first wavelength division multiplexing filter, a second wavelength division multiplexing filter, and an optical circulator;

 a test module near the extension box, configured to provide a detection light source for performing optical line detection on the branch fiber after the extension box; receiving an instruction from the OLT to initiate detection by the extension box, and outputting the detection signal to the optical circulator First interface;

 a first wavelength division multiplexing filter for receiving a reflected signal from the optical circulator and outputting from the universal interface to the trunk optical fiber, and transmitting to the test module at the OLT;

a second wavelength division multiplexing filter, configured to receive a detection signal from the optical circulator, and output the signal from the general interface to the optical splitter to enter the branch fiber to reach the ONU; the second wavelength division multiplexing filter The universal interface receives the reflected signal of the test module of the branch fiber, and outputs the signal from the second branch interface of the branch to the second interface of the optical circulator;

 An optical circulator for receiving a detection signal from a test module near the extension box, and outputting the detection signal from its second interface to a second branch interface of the second wavelength division multiplexing filter; receiving the second wavelength component The reflected signal of the filter is multiplexed and outputted from its third interface to the second branch interface of the first wavelength division multiplexing filter.

 a light guiding module is disposed between the extension box and the optical splitter, and the light guiding module is connected to the testing module. When the testing module is connected to the data processing module, the light guiding module is a wavelength division multiplexing filter, and the wave is The common interface of the multiplex filter is connected to the optical splitter, the first branch interface of the WDM filter is connected to the extension box, and the second branch interface of the WDM filter is connected to the test module;

 a data processing module, configured to receive a command to start a test, issue a test instruction to the test module, and analyze and process the obtained data, and send the result to the extension box

OLT;

 a test module near the extension box, configured to output the received detection signal to the second branch interface of the wavelength division multiplexing filter; receive the reflected signal from the wavelength division multiplexing filter and output the data to the data processing module ;

 a wavelength division multiplexing filter, configured to output the received detection signal from the test module near the extension box from its universal interface to the optical splitter and the branch fiber; the universal interface of the wavelength division multiplexing filter receives the branch fiber The test module reflects the signal and enters the test module near the extension box from its second branch interface.

 The apparatus also includes a coupler disposed at the OLT for connecting the test module at the OLT to the backbone fiber for optical line detection of the backbone fiber between the OLT and the extension box.

The wavelength division multiplexing filter is a sideband filter for transmitting wavelengths below 1620 nm, transmitting at wavelengths above 1625 nm, and there is a 5 nm safety isolation band. It can be seen from the above technical solution provided by the present invention that the detection path is divided into a main fiber and a branch fiber by the extension box, and the optical line detection is performed on the trunk fiber and the branch fiber, respectively. The method of the invention overcomes the blocking of the OTDR signal by the extension box, and compensates for the additional optical loss caused by the long-range optical fiber, thereby meeting the optical line detection requirement of the long-distance PON, and realizing the optical line detection of the entire PON network. . DRAWINGS

 1 is a schematic structural diagram of a conventional long-distance passive optical network;

 2 is a flow chart of a method for implementing optical line detection in a long-range passive optical network according to the present invention; a schematic structural diagram of the structure; a schematic structural diagram of the composition; detailed description

 The technical solutions of the present invention are further elaborated below in conjunction with the accompanying drawings and specific embodiments. 2 is a flow chart of a method for implementing optical line detection in a long-range passive optical network according to the present invention. As shown in FIG. 2, the method includes:

 Step 200: The detection path is divided into a main fiber and a branch fiber by using an extension box as a boundary, and the extension box is connected to the trunk fiber and the branch fiber.

 In this step, the optical line detection path can be divided into two types: the main fiber and the branch fiber by the following methods:

A. placing a light guiding module between the extension box and the optical splitter to provide an interface for introducing a test signal; or B. placing a light guiding module before and after the extension box, and introducing the test signal into the beam splitter and the subsequent branch fiber, and the test reflection signal from the branch fiber is coupled to the trunk fiber through the light guiding module; or

 C. Place a light guide module between the extension box and the optical splitter. The light guide module is connected to the test module, and the test module is connected to the data processing module.

 The method A includes: the light guiding module is a wavelength division multiplexing filter, and the extension box is connected to a branch interface of the wavelength division multiplexing filter, and the optical splitter is connected with a common interface of the wavelength division multiplexing filter, and the wave The other branch interface of the sub-multiplexing filter serves as the connection port of the test module.

 The method B includes: the light guiding module is composed of a first wavelength division multiplexing filter, a second wavelength division multiplexing filter, and an optical circulator; the universal interface of the first wavelength division multiplexing filter is connected to the backbone optical fiber, One end of the first branch interface extension box of the wavelength division multiplexing filter is connected, and the second branch interface of the first wavelength division multiplexing filter is connected with the optical circulator; the common interface and the splitting of the second wavelength division multiplexing filter Connected, the first branch interface of the second wavelength division multiplexing filter is connected to the other end of the extension box, and the second branch interface of the second wavelength division multiplexing filter is connected to the optical circulator; the optical circulator is also connected to the test module connection.

 The method C specifically includes: the light guiding module is a wavelength division multiplexing filter, and a universal interface of the wavelength division multiplexing filter is connected to the optical splitter, and the first branch interface of the wavelength division multiplexing filter is connected with the extension box, and the wavelength division The second branch interface of the multiplexing filter is connected to the test module.

 Step 201: Perform optical line detection on the trunk fiber and the branch fiber respectively.

 Step 202: The detection data or signal of the branch fiber is transmitted to the OLT, and the OLT combines the detection results of the backbone fiber and the branch fiber to complete the optical line detection of the entire long-distance passive optical network.

After the path is divided according to step 200, at the OLT, the test module's signal is coupled into the optical fiber by using the test module at the OLT, and the optical line detection signal is blocked in front of the extension box, thereby realizing the connection between the OLT and the extension box. Optical line detection of the backbone fiber; and for the branch after the extension box For the optical line detection of optical fibers, the following methods can be used for different detection methods: The detection method corresponding to the above method A is: using the test module from the interface of the test module, performing the optical line of the branch fiber after the extension box Detection

 Alternatively, the detection method corresponding to the foregoing mode B is: the OLT controls the test module by using an extension box, and the signal of the test module is coupled into the optical splitter; the light reflection signal of the test module bypasses the extension box and enters the trunk optical fiber, and then transmits Go to the test module at the OLT.

 Alternatively, the detection method corresponding to the foregoing mode C is: the OLT controls the test module by using an extension box, and the signal of the test module is coupled into the optical splitter; the reflected signal of the test module is returned to the test module and processed, and then extended The box is passed back to the OLT.

 It should be noted that the test module in the embodiment of the present invention includes but is not limited to an OTDR, and an OTDR will be described as an example in the following embodiments.

 For the method of the present invention, there is provided an apparatus comprising at least an extension box, an OTDR or OTDR optical transmitter or an OTDR optical module disposed near the extension box, and an OTDR disposed at the OLT, wherein

 With the extension box as the boundary, the optical line detection path is divided into two main channels: the main fiber and the branch fiber:

 The light guide module is connected between the extension box and the optical splitter to introduce an interface of the OTDR; or the light guide module is inserted before and after the extension box, and the light of the OTDR light emitter is introduced into the optical splitter and the subsequent branch fiber, and the branch fiber is branched. The light detecting reflected signal is coupled back to the trunk fiber through the light guide module bypassing the extension box; or

 The optical module is connected between the extension box and the optical splitter. The optical module is connected to the optical module and data processing module of the OTDR, and the data is transmitted back to the OLT through the extension box.

An OTDR is provided at the OLT for optical line detection of the backbone fiber. The devices of different detection modes are described in detail below. Schematic diagram of the structure of the structure, as shown in FIG. 3, the apparatus includes at least an extension box and a wavelength division multiplexing filter, wherein

 The wavelength division multiplexing filter, as a light guiding module, is disposed between the extension box and the optical splitter, and the general interface of the wavelength division multiplexing filter (C interface in the figure) is connected to the interface (S7R') of the optical splitter ( As indicated in Figure 1, the first branch interface of the wavelength division multiplexing filter (P interface in the figure) is connected to the extension box, and the second branch interface of the wavelength division multiplexing filter (the R interface in the figure) is The interface of the OTDR is used to couple the signal of the OTDR to separate the reflected signal of the OTDR from the main signal stream.

 The design of the wavelength division multiplexing filter is related to the wavelength selection of the OTDR, where the wavelength division multiplexing filter can be a sideband filter that transmits both wavelengths below 1620 nm and transmits wavelengths above 1625 nm. 5nm safety barrier.

 The working principle of the first embodiment of the device of the present invention shown in FIG. 3 is as follows: The OTDR is connected in the manner of FIG. 3, and the OTDR is opened to perform optical line detection on the branch fiber between the extension box and the ONU (also referred to as fault detection). ). In addition, at the OLT, a coupler can be used to connect the OTDR to the trunk fiber, so that the optical line detection of the trunk fiber between the OLT and the extension box can be completed (not shown in FIG. 3, as shown in FIG. This implementation is well-known in the art, and the specific implementation of the connection will not be repeated here.

Through the detection of the first embodiment, the full optical line detection for the entire long-distance PON is completed. In the apparatus shown in the first embodiment, only one passive light guiding device, that is, a wavelength division multiplexing filter, is added, but the device shown in the first embodiment cannot perform all the light effects on the long-distance PON at the local OLT. Together, all optical line detection for long-haul PONs can be achieved. This solution has minimal changes to the system. Schematic diagram of the structure of the structure, as shown in Figure 4, the device includes at least an extension box, OTDR light emission a first wavelength division multiplexing filter, a second wavelength division multiplexing filter, and an optical circulator; wherein the first wavelength division multiplexing filter, the second wavelength division multiplexing filter, and the optical circulator constitute a guide Optical module. Detection source.

 The OTDR optical transmitter is powered by an extension box, and the OLT manages and controls the OTDR optical transmitter through an extension box.

 When the OTDR optical transmitter is connected to the OLT detection command, the signal of the OTDR optical transmitter enters the interface 1 of the optical circulator, and then enters the second branch interface of the second wavelength division multiplexing filter from the interface 2 of the optical circulator ( The R interface in the figure) enters the splitter and the branch fiber from the common interface of the second wavelength division multiplexing filter (C interface in the figure); and the reflected signal of the OTDR optical transmitter passes through the second wave splitting Use the filter C interface to the R interface, the optical circulator interface 2 to the interface 3 and the R-interface of the first wavelength division multiplexing filter to the optical path formed by the C interface, bypass the extension box to enter the trunk fiber, and finally transmit to the OLT On the OTDR.

 The first wavelength division multiplexing filter is configured to establish an interface for the detection signal of the branch fiber to bypass the optical path of the extension box and return to the OTDR at the OLT without affecting the normal optical communication channel. Therefore, the general interface of the first wavelength division multiplexing filter (C interface in the figure) is connected to the (R7S') interface of the backbone fiber, and the first branch interface of the first wavelength division multiplexing filter (P in the figure) The interface is connected to one end of the extension box, and the second branch interface of the first wavelength division multiplexing filter (the R interface in the figure) is connected to the interface 3 of the optical circulator.

 A second wavelength division multiplexing filter is used to couple the signal of the OTDR optical transmitter into the branch fiber; and the reflected signal of the OTDR optical transmitter is separated from the mainstream signal. The C interface of the second wavelength division multiplexing filter is connected to the (S7R') interface of the optical splitter, and the first branch interface of the second wavelength division multiplexing filter (P interface in the figure) is connected to the other end of the extension box The second branch interface of the second wavelength division multiplexing filter (the R interface in the figure) is connected to the optical circulator interface 2.

The design of the wavelength division multiplexing filter is related to the wavelength selection of the OTDR, here first and second The wavelength division multiplexing filters can each be a sideband filter that transmits both wavelengths below 1620 nm and transmits wavelengths above 1625 nm. It has a 5 nm safety isolation barrier.

 The optical circulator is configured to introduce the OTDR optical transmitter into the second wavelength division multiplexing filter, and simultaneously direct the reflected signal of the OTDR optical transmitter to the first wavelength division multiplexing filter. The interface 2 of the optical circulator is connected to the R interface of the second wavelength division multiplexing filter, the interface 1 of the optical circulator is connected to the OTDR optical transmitter, the interface 3 of the optical circulator and the R of the first wavelength division multiplexing filter Interface connection.

 The device shown in FIG. 4 constitutes three optical paths, and the first optical channel is a trunk optical path composed of a first wavelength division multiplexing filter, an extension box and a second wavelength division multiplexing filter, and is used for uplink and downlink light. The second optical channel is an optical path of a detection source of a branch fiber composed of an OTDR optical transmitter, an optical circulator, and a second wavelength division multiplexing filter, and is used to introduce a signal of the OTDR optical transmitter onto the branch fiber. Performing optical line detection on the third optical channel; the return path of the reflected signal of the OTDR optical transmitter consisting of the second wavelength division multiplexing filter, the optical circulator and the first wavelength division multiplexing filter, The detection signal of the branch fiber behind the extension box is transmitted via the backbone fiber to the OTDR at the OLT.

 The working principle of the second embodiment of the apparatus of the present invention shown in FIG. 4 is that the optical line detection of the backbone fiber is performed by the OTDR at the OLT, the process of which is described in the first embodiment shown in FIG. Narration.

The optical line detection of the branched fiber is achieved by the apparatus described in FIG. First, the OLT sends an instruction to initiate detection to the OTDR optical transmitter through the extension box. The detection signal of the OTDR optical transmitter enters from the interface 1 of the optical circulator, and then outputs from the interface 2 of the optical circulator to the second wavelength division multiplexing. The R interface of the filter is output from the C interface of the second wavelength division multiplexing filter to the optical splitter to enter the branch fiber to reach the ONU; the reflected signal of the OTDR optical transmitter of the branched optical fiber enters the second wavelength division multiplexing filter from the optical splitter. The C interface of the device is then output from the R interface of the second wavelength division multiplexing filter to the optical circulator interface 2, and then output from the optical circulator interface 3 and enter the R interface of the first wavelength division multiplexing filter, and then The C interface of the first wavelength division multiplexing filter is output to the trunk fiber, and after transmission The OTDR is sent to the OLT at the OLT; the OTDR then processes the received branch fiber and the backbone fiber signal and transmits it to the OLT. The OLT combines the results to complete the optical line detection of the entire long-distance PON.

 Through the apparatus of the second embodiment shown in FIG. 4, the optical line inspection of the original long-distance PON system is broken, so that the operator can automatically perform the optical line of the entire long-distance PON with one OTDR at one time at the local OLT. The detection and result processing saves the inspection time for the operator, saves the labor cost of the inspection, and ultimately saves the operation cost for the operator. The schematic structure of the structure, as shown in FIG. 5, the device includes at least an OTDR optical module, a data processing module, a wavelength division multiplexing filter, and an extension box, where

 The OTDR optical module is configured to perform optical line detection on the branch fiber. The OLT sends a start detection command to the OTDR optical module through the extension box. The detection signal of the OTDR optical module is coupled into the optical splitter and the branch fiber through a wavelength division multiplexing filter. The reflected signal is returned to the optical module of the OTDR through the wavelength division multiplexing filter. The signal is processed by the data processing module and transmitted to the OLT through the EONT of the extension box. The OLT synthesizes the result and the detection result of the backbone fiber to complete the entire long distance. Optical line detection of PON systems.

 The data processing module is configured to perform data processing on the reflected signal of the OTDR optical module, and transmit the processed result to the OLT through the local optical fiber through the local controller and the EONT. If the local controller in the extension box has sufficient additional data processing capability, the data processing module in this embodiment will be omitted.

The wavelength division multiplexing filter is disposed between the optical splitter and the extension box, and is configured to couple the signal of the OTDR optical module into the branch fiber, and separate the reflected signal of the OTDR optical module from the mainstream signal and return it to the OTDR optical module. . The C interface of the wavelength division multiplexing filter is connected to the (S7R') interface of the optical splitter, and the P interface of the wavelength division multiplexing filter is connected to the extension box, and the R of the wavelength division multiplexing filter The interface is connected to the OTDR optical module.

 The design of the wavelength division multiplexing filter is related to the wavelength selection of the OTDR, where the wavelength division multiplexing filter can be a sideband filter that transmits both wavelengths below 1620 nm and transmits wavelengths above 1625 nm. 5nm safety barrier.

 The working principle of the third embodiment of the device of the present invention shown in FIG. 5 is: issuing a command to start a test to the data processing module located at the extension box by extending the existing EONT of the box, the OTDR to which the data processing module is connected The optical module issues a test command, and the OTDR optical module sends a detection signal to the R interface of the wavelength division multiplexing filter, and then enters the optical splitter and the branch optical fiber from the C interface of the wavelength division multiplexing filter; then the reflected signal of the OTDR of the branched optical fiber passes through The C interface of the wavelength division multiplexing filter is split into the R interface and enters the OTDR optical module, and is transmitted to the data processing module. The module analyzes and processes the obtained data, and sends the result through the EONT of the extension box. Give the OLT. In addition, at the OLT, a coupler can be used to connect the OTDR to the trunk fiber, so that the optical line detection of the trunk fiber between the OLT and the extension box can be completed (not shown in FIG. 5, combined with FIG. 1). This implementation is well known to those skilled in the art, and the specific implementation of the connection will not be repeated here. In this way, the OLT integrates the optical line detection of the entire long-distance PON system based on the result and the data of the backbone fiber measured by the OTDR.

 The device shown in Figure 5 is the most automated, and the optical line detection of the backbone fiber and the optical line detection of the branched fiber can be performed simultaneously. The OTDR does not need to be modified. Through the apparatus of the third embodiment shown in FIG. 5, the operator can perform complete optical line detection on the entire long-distance PON at the local OLT, and at the same time, the OTDR signal of the branch fiber is prevented from being damaged by the long-distance transmission. Less. It saves operators time for testing, saves labor costs for testing, and ultimately saves operators operating costs.

 The above description is only for the preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included. Within the scope of protection of the present invention.

Claims

Claim  A method for implementing optical line detection in a long-range passive optical network (PON), characterized in that:  The extension box connects the trunk fiber and the branch fiber by:  Placing a light guiding module between the extension box and the optical splitter for providing an interface for introducing a test signal; or  A light guiding module is disposed before and after the extension box, and the test signal is introduced into the beam splitter and the subsequent branch fiber, and the test reflection signal from the branch fiber is coupled to the trunk fiber through the light guiding module; or  A light guiding module is disposed between the extension box and the optical splitter, the light guiding module is connected to the testing module, and the testing module is connected to the data processing module;  Optical line detection of trunk fibers and/or branch fibers.  The method of claim 1 , wherein the light guiding module is disposed between the extension box and the optical splitter to provide an interface for introducing a test signal, specifically: the light guiding module is a wave division With a filter, the extension box is connected to a branch interface of the wavelength division multiplexing filter, the beam splitter is connected to the general interface of the wavelength division multiplexing filter, and the other branch interface of the wavelength division multiplexing filter is used as the connection port of the test module. ;  Correspondingly, the optical line detection is performed on the trunk fiber and the branch fiber respectively: the test module is used to detect the light path of the branch fiber behind the extended box from the interface of the test module.  3. The method according to claim 1, wherein the light guiding module is placed before and after the extension box, and the test signal is introduced into the beam splitter and the subsequent branch fiber, and the test reflection signal of the branch fiber passes. The light guiding module is coupled to the trunk fiber, specifically: The light guiding module is composed of a first wavelength division multiplexing filter, a second wavelength division multiplexing filter and an optical circulator; a common interface of the first wavelength division multiplexing filter is connected to a trunk optical fiber, and the first wavelength division One end of the first branch interface extension box of the multiplexing filter is connected, and the second branch interface of the first wavelength division multiplexing filter is connected to the optical circulator; the common interface and the optical splitter of the second wavelength division multiplexing filter Connecting, the first branch interface of the second wavelength division multiplexing filter is connected to the other end of the extension box, and the second branch interface of the second wavelength division multiplexing filter is connected to the optical circulator; the optical circulator is also connected to the test module ;  Correspondingly, the optical line detection of the trunk fiber and the branch fiber respectively is:  The test module is controlled by the OLT through the extension box, and the signal of the test module is coupled to the optical splitter; the light reflection signal of the test module bypasses the extension box and enters the trunk fiber, and then is transmitted to the test module at the OLT.  The method of claim 1 , wherein the light guide module is placed between the extension box and the optical splitter, the light guide module is connected to the test module, and the test module is connected to the data processing module, specifically: The light guiding module is a wavelength division multiplexing filter, and a general interface of the wavelength division multiplexing filter is connected to the optical splitter, and a first branch interface of the wavelength division multiplexing filter is connected to the extension box, and the wavelength division is The second branch interface of the multiplexing filter is connected to the test module;  Correspondingly, the optical line detection of the trunk fiber and the branch fiber respectively is:  The OLT controls the test module through the extension box, and the signal of the test module is coupled to the optical splitter. The reflected signal of the test module is returned to the test module and processed, and then transmitted back to the OLT through the extension box.  The method according to any one of claims 1 to 4, further comprising: coupling the signal of the test module into the optical fiber at the OLT by using a test module at the OLT, and completing the OLT to the extended box Optical line detection between the backbone fibers.  6. A device for implementing optical line detection in a long-range passive optical network (PON), characterized in that it comprises at least an extension box, a test module disposed near the extension box, and a test module disposed at the OLT. among them, The extension box connects the trunk fiber and the branch fiber by: Locating a light guiding module between the extension box and the optical splitter for providing an interface for introducing a test signal; or  A light guiding module is disposed before and after the extension box, and the test signal is introduced into the beam splitter and the subsequent branch fiber, and the test reflection signal from the branch fiber is coupled to the trunk fiber through the light guiding module; or  A light guiding module is disposed between the extension box and the optical splitter, the light guiding module is connected to the testing module, and the testing module is connected to the data processing module;  A test module is provided at the OLT for optical line detection of the backbone fiber.  7. Apparatus according to claim 6 wherein:  In the case where a light guiding module is disposed between the extension box and the optical splitter for providing an interface for introducing a test signal, the light guiding module is a wavelength division multiplexing filter, a signal for coupling the test module, and a test is to be performed. The reflected signal of the module is separated from the main signal stream;  a general interface of the wavelength division multiplexing filter is connected to the optical splitter, a first branch interface of the wavelength division multiplexing filter is connected to the extension box, and a second branch interface of the wavelength division multiplexing filter is used as The connection port of the test module.  The apparatus according to claim 6, wherein, in a case where a light guiding module is placed before and after the extension box, the light guiding module is configured by a first wavelength division multiplexing filter and a second wavelength division a multiplexing filter and an optical circulator; wherein  a test module near the extension box, configured to provide a detection light source for performing optical line detection on the branch fiber after the extension box; receiving an instruction from the OLT to initiate detection by the extension box, and outputting the detection signal to the optical circulator First interface;  a first wavelength division multiplexing filter for receiving a reflected signal from the optical circulator and outputting from the universal interface to the trunk optical fiber, and transmitting to the test module at the OLT; a second wavelength division multiplexing filter, configured to receive a detection signal from the optical circulator, and output the signal from the general interface to the optical splitter to enter the branch fiber to reach the ONU; the second wavelength division multiplexing filter The universal interface receives the reflected signal of the test module of the branch fiber, and outputs the signal from the second branch interface of the branch to the second interface of the optical circulator;  An optical circulator for receiving a detection signal from a test module near the extension box, and outputting the detection signal from its second interface to a second branch interface of the second wavelength division multiplexing filter; receiving the second wavelength component The reflected signal of the filter is multiplexed and outputted from its third interface to the second branch interface of the first wavelength division multiplexing filter.  The device according to claim 6, wherein a light guiding module is disposed between the extension box and the optical splitter, and the light guiding module is connected to the testing module, and the testing module is connected to the data processing module. The light guiding module is a wavelength division multiplexing filter, and a general interface of the wavelength division multiplexing filter is connected to the optical splitter, and a first branch interface of the wavelength division multiplexing filter is connected to the extension box, and the wavelength division is The second branch interface of the multiplexing filter is connected to the test module;  a data processing module, configured to receive a command to start a test, issue a test command to the test module, and analyze and process the obtained data, and send the result to the OLT through the extension box;  a test module near the extension box, configured to output the received detection signal to the second branch interface of the wavelength division multiplexing filter; receive the reflected signal from the wavelength division multiplexing filter and output the data to the data processing module ;  a wavelength division multiplexing filter, configured to output the received detection signal from the test module near the extension box from its universal interface to the optical splitter and the branch fiber; the universal interface of the wavelength division multiplexing filter receives the branch fiber The test module reflects the signal and enters the test module near the extension box from its second branch interface.  The device according to any one of claims 6 to 9, wherein the device further comprises: a coupler disposed at the OLT, configured to connect the test module at the OLT to the trunk fiber, and complete the OLT Optical line detection of the backbone fiber between the extension boxes. 11. Apparatus according to any one of claims 6 to 9 wherein: The wavelength division multiplexing filter is a sideband filter for transmitting wavelengths above 1620 nm to wavelengths above 1625 nm, and there is a 5 nm safety isolation band.