JP2010212778A - Pon system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To speedily detect continuous light emission abnormality due to light emitting element abnormality with respect to a PON (Passive Optical Network) system which transmits and receives transmission optical signals by time-division multiplexing. <P>SOLUTION: In the PON system, an OLT 1 and a plurality of ONUs 2-1 to 2-n are connected by an optical transmission line through an optical coupler part 3, optical signals are transmitted from the plurality of ONUs 2-1 to 2-n to the OLT 1 in transmission timing allocated thereto respectively, and optical signals are transmitted from the OLT 1 to the respective ONUs 2-1 to 2-n by time multiplexing in allocated reception timing corresponding to the ONUs 2-1 to 2-n. The optical coupler part 3 includes a means of detecting transmission optical signals corresponding to the ONUs 2-1 to 2-n to determine whether continuous light emission abnormality occurs based upon detection output signals of optical detection parts 4-1 to 4-n. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention connects a plurality of optical subscriber terminals (ONU; Optical Network Unit) to an optical subscriber line accommodation apparatus (OLT; Optical Line Terminal) via an optical coupler through a single optical transmission line. The present invention relates to a PON (Passive Optical Network) system that transmits and receives data in a time division multiplexed manner.

  The PON system is an optical subscriber terminal (optical subscriber line terminating device) (hereinafter abbreviated as “ONU”) installed in a plurality of distributed subscriber homes and an optical subscriber on the station side via an optical coupler. A line accommodating device (hereinafter abbreviated as “OLT”) is connected by an optical transmission line, and transmission data from the OLT to each ONU is time-division multiplexed, and each ONU receives the allocation timing data. The data transmitted at the allocation timing is time-division multiplexed in the optical coupler and transmitted to the OLT. The transmission / reception timing corresponding to the ONU is adjusted and set based on the transmission time measurement with each ONU on the OLT side, and is notified to each ONU so as to be time-multiplexed in the optical coupler.

  The PON system as described above has already been proposed in various configurations, and various duplex configurations have been proposed to improve reliability. For example, an active interface board and a spare interface board are provided on the OLT side. When the data received from each ONU via the optical coupler is stored in the memories of the active interface board and the spare interface board, and the received data at the same timing is compared to indicate the same data A PON system that determines normality has been proposed (see, for example, Patent Document 1).

JP 2001-119348 A

  When an optical signal is sent continuously or at a timing other than the allocation timing due to a failure in one of the ONUs, it is transmitted at the allocation timing of another ONU due to time division multiplexing by the optical coupler. Interfering light signal with respect to the received optical signal. As a result, normal ONU transmission is inhibited. When such a failure occurs, it cannot be determined which of the ONUs is faulty. Therefore, the maintenance staff visits each ONU in order to check whether it is normal. Increases with the number of ONUs, which increases the maintenance cost. In addition, it is conceivable to instruct each ONU to stop optical signal transmission from the OLT side and investigate whether or not the interfering light signal is stopped. In order to specify whether or not a failure occurs, it is necessary to send out a transmission stop instruction and a transmission start instruction for each device sequentially, and there is a problem that it takes a relatively long time.

  Therefore, it is possible to detect a faulty ONU at least in the optical coupler unit and quickly repair it to avoid service degradation.

  In the present invention, an optical subscriber line accommodating device (OLT) and a plurality of optical subscriber terminals (ONUs) are connected by an optical transmission line via an optical coupler unit, and each of the plurality of ONUs is assigned to an OLT. In the PON system that transmits an optical signal at a transmission timing that is transmitted, and transmits an optical signal by time-multiplexing from the OLT to the ONU at a reception timing assigned to each ONU, the optical coupler unit transmits the signal corresponding to the ONU. A configuration is provided in which a light detection unit capable of detecting an optical signal and monitoring whether or not a continuous light emission abnormality has occurred is provided.

  The optical coupler unit receives an optical coupler that branches the ONU-compatible transmission optical signal, a light detection unit that inputs the transmission optical signal branched by the optical coupler, and a detection signal from the light detection unit. And a monitoring unit for determining whether or not the transmission light signal is due to a continuous light emission abnormality.

  The optical coupler unit inputs an optical coupler that branches the ONU-compatible transmission optical signal, an optical switch that selectively switches the transmission optical signal branched by the optical coupler, and a transmission optical signal selected by the optical switch. A configuration that includes a light detection unit and a monitoring unit that performs switching control of the optical switch and inputs a detection signal from the light detection unit to determine whether or not the transmission light signal is due to a continuous light emission abnormality. Have.

  Further, the monitoring unit includes a PON interface unit that notifies the OLT by an OAM frame or an abnormality notification frame to which information indicating an optical subscriber terminal in which the continuous light emission abnormality has occurred is added upon detection of the continuous light emission abnormality.

  In addition, the OLT and a plurality of ONUs are connected by an optical transmission line via an optical coupler unit, and an optical signal is transmitted from each of the plurality of ONUs to the OLT at an assigned transmission timing. From the OLT to the ONU, A PON system that transmits time-multiplexed optical signals at an assigned reception timing, wherein an optical coupler unit selectively switches a transmission optical signal from an ONU, and a transmission optical signal selected by the optical switch And an optical switch control unit for selecting and controlling the optical switch by an external control input.

  The optical coupler unit includes an optical switch control unit that selectively controls the optical switch, a monitoring unit that monitors the presence or absence of a continuous light emission abnormality based on an output signal of a light detection unit that inputs a transmission optical signal, based on selection control of the optical switch, A monitoring control unit having a configuration including an OAM frame to which information indicating an optical subscriber terminal in which the continuous light emission abnormality has occurred or a PON interface unit for sending an abnormality notification frame to the OLT is detected by the continuous light emission abnormality detection by the monitoring unit. ing.

  The ONU also includes a monitoring control unit that issues an instruction to control the selection of the optical switch of the optical coupler unit, and receives and processes information about the ONU in which continuous light emission abnormality has occurred.

  In the optical coupler unit, it is not necessary to test at each ONU installation location by providing a light detection unit to determine whether or not there is a continuous light emission abnormality for each ONU. Therefore, each ONU is distributed and arranged. Even if the optical coupler unit or OLT is used, it is possible to identify the occurrence of continuous light emission abnormality and to identify the abnormal ONU, and to perform quick repair work. Can do.

It is explanatory drawing of Example 1 of this invention. It is explanatory drawing of Example 2 of this invention. It is explanatory drawing of Example 3 of this invention. It is explanatory drawing of Example 4 of this invention. It is explanatory drawing of Example 5 of this invention. It is explanatory drawing of Example 6 of this invention. It is explanatory drawing of Example 7 of this invention. It is explanatory drawing of Example 8 of this invention. It is explanatory drawing of Example 9 of this invention. It is explanatory drawing of Example 10 of this invention. It is explanatory drawing of Example 11 of this invention. It is explanatory drawing of Example 12 of this invention. It is explanatory drawing of Example 13 of this invention. It is explanatory drawing of Example 14 of this invention. It is explanatory drawing of Example 15 of this invention. It is explanatory drawing of Example 16 of this invention. It is explanatory drawing of Example 17 of this invention. It is explanatory drawing of Example 18 of this invention.

  In the present invention, referring to FIG. 1, an optical subscriber line accommodating device (OLT) 1 and a plurality of optical subscriber terminals (ONUs) 2-1 to 2-n are optically connected via an optical coupler unit 3. The optical signals are transmitted from the plurality of ONUs 2-1 to 2-n to the OLT 1 at transmission timings assigned thereto, and the ONTs 2-1 to 2-n are assigned to the respective ONUs. A PON system that transmits an optical signal by time multiplexing at a reception timing, and the optical coupler unit 3 can detect a transmission optical signal corresponding to the ONUs 2-1 to 2-n and monitor whether or not a continuous light emission abnormality has occurred. The photo detectors 4-1 to 4-n are provided.

  FIG. 1 is an explanatory diagram of a first embodiment of the present invention, showing a main part of a PON system, and a plurality of ONUs (optical subscriber line termination devices) for an OLT (optical subscriber line accommodation device) 1 on the station side. 2-1... 2-n are connected by an optical fiber through the optical coupler unit 3, and the optical coupler unit 3 is connected to the ONUs 2-1 to 2-n before the multiplexing. The light detection units 4-1 to 4-n are provided for detecting the optical signal. The light detection units 4-1 to 4-n may emit continuous light when, for example, the light emitting elements emit light other than the assigned transmission timing due to the failure of the light emitting elements for transmission of the ONUs 2-1 to 2-n or their drive circuits. It has a configuration that can detect a case where a state is reached. At the normal time, each ONU 2-1 to 2-n starts transmitting an optical signal at the transmission timing assigned from the OLT 1 and continues transmitting the optical signal only for a predetermined period. For the OLT 1, A time-multiplexed optical signal is transmitted. Therefore, it is normal if the detection output signals of the light detection units 4-1 to 4-n are intermittent, and it can be determined as a continuous light emission failure if the detection output signals are continuous. For example, monitoring is performed by a flip-flop or the like that is set by the detection output signals of the photodetectors 4-1 to 4-n at each assigned transmission timing, and resets by the optical signal zero in the idle period. The continuous light emission failure of the 2-n light emitting elements is generated, and the detection result of such failure is displayed on the outside of the optical coupler unit 3 by display means not shown or communication not shown to the OLT 1 It is also possible to notify the OLT 1 by applying a means for multiplexing and transmitting optical signals, by notifying by means, or by adding information that can identify ONUs having a continuous light emission failure. As a result, it is possible to identify the ONU in which the failure has occurred without sequentially inspecting the installation locations of the respective ONUs 2-1 to 2-n, and it is possible to quickly stop the transmission of the ONU in which the continuous light emission failure has occurred and repair it. It is possible to resume normal ONU transmission / reception by performing work. Note that power for operation of the light detection units 4-1 to 4-n provided in the optical coupler unit 3 can be supplied from the OLT 1 side, or a commercial power source in the vicinity of the optical coupler unit 3 can be used. is there.

  FIG. 2 is an explanatory diagram of a second embodiment of the present invention, where the same reference numerals as those in FIG. 1 denote the same names, 4-1 to 4-n denote light detection units, and 5-1 to 5-n denote ONU2-. Optical couplers corresponding to 1 to 2-n and 6-1 to 6n denote monitoring units. In the second embodiment, the optical coupler unit 3 between the ONUs 2-1 to 2-n and the OLT 1 combines and demultiplexes optical signals with respect to the original ONUs 2-1 to 2-n. The optical signals from the ONUs 2-1 to 2-n before being waved are demultiplexed by the optical couplers 5-1 to 5-n and input to the light detection units 4-1 to 4-n, and the monitoring units 6-1 to 6-1 are performed. 6-n monitors whether or not the ONUs 2-1 to 2-n have a continuous light emission failure. When the continuous light emission failure is detected, the OLT 1 is connected to another communication network (not shown) or the OLT 1 and the ONUs 2-1 to ON. An optical signal having a wavelength different from the optical signal wavelength used between 2-n can be multiplexed and notified to the optical signal as the main signal between the OLT 1 and the ONUs 2-1 to 2-n. As described above, when the failure occurrence notification is transmitted to the OLT 1 after wavelength multiplexing, the OLT 1 can receive and process the failure occurrence notification by wavelength separation. Thereby, it is possible to detect the ONU in which the continuous light emission failure has occurred and perform the repair work quickly. In this case, the monitoring units 6-1 to 6-n receive the transmission timing information assigned to the ONUs 2-1 to 2-n through a communication path (not shown), and at timings other than the transmission timing. When a transmission optical signal is detected, it is possible to detect the occurrence of continuous light emission failure or transmission timing control function failure. Accordingly, it is possible to quickly stop and repair the ONU that transmits the interference light signal.

  FIG. 3 is an explanatory diagram of a third embodiment of the present invention, where the same reference numerals as those in FIGS. 1 and 2 indicate the same name, 6 is a common monitoring unit, and 7 is a means for displaying a failure occurrence display or failure occurrence notification. The interface part provided with is shown. This embodiment shows a case where the monitoring unit 6 can determine whether a continuous light emission abnormality has occurred based on detection signals of transmission optical signals from the light detection units 4-1 to 4-n. When detecting the occurrence of a continuous light emission failure, the failure occurrence ONU is notified to the OLT side (not shown) by displaying the failure occurrence by the light emitting element provided in the interface unit 7 or other communication network (not shown) or optical signal wavelength multiplexing. can do. As a result, it is possible to quickly perform repair work on an ONU in which a continuous light emission failure has occurred. The monitoring unit 6 receives the transmission timing information assigned to the ONUs 2-1 to 2-n via a communication path (not shown) and detects the transmission optical signal at a timing other than the transmission timing. In this case, a function for detecting the occurrence of continuous light emission failure or transmission timing control function failure may be provided.

  FIG. 4 is an explanatory diagram of a fourth embodiment of the present invention. The same reference numerals as those in FIGS. 1 to 3 denote the same parts, 4 is a light detection unit, 8 is an optical coupler, and 9 is an optical switch (optical SW). Indicates. In this embodiment, the optical couplers 5-1 to 5-n corresponding to the ONUs 2-1 to 2-n branch the transmission optical signals from the ONUs 2-1 to 2-n into two, one between the OLT and the OLT. The optical signal is input to the optical coupler 8 having the original function for multiplexing and demultiplexing the optical signal, and the other is input to the optical switch 9. The optical switch 9 selects one of the optical signals demultiplexed by the optical couplers 5-1 to 5 -n and inputs the selected optical signal to the light detection unit 4 under the control of the monitoring unit 6. The monitoring unit 6 controls the optical switch 9 to input the optical signal branched by the optical couplers 5-1 to 5-n corresponding to the ONUs 2-1 to 2-n to the light detection unit 4, and based on the light detection signal Monitor whether a continuous light emission failure has occurred. In this case, the switching speed of the optical switch 9 is set to be lower than the switching speed of the transmission timing assigned to each of the ONUs 2-1 to 2-n. Thereby, it is possible to identify the ONU selected by the optical switch 9 and whether or not a continuous light emission failure that transmits an optical signal occurs in addition to the assigned transmission timing. In this case, the monitoring unit 6 receives the transmission timing information assigned to each of the ONUs 2-1 to 2-n via a communication path (not shown), and for each period in which the repetition cycle of the transmission timing is plural. By performing control to sequentially switch the optical switches 9, it is possible to determine whether or not a continuous light emission failure has occurred in the selection period corresponding to each ONU 2-1 to 2-n. In addition, display by failure occurrence detection, notification to the OLT, and the like can be executed by the interface unit 7. As described above, it is possible to automatically detect the continuous light emission failure of each of the ONUs 2-1 to 2-n and notify it to the OLT. Therefore, the continuous light emission failure recovery processing can be performed quickly.

  FIG. 5 is an explanatory diagram of a fifth embodiment of the present invention. The same reference numerals as those in the above-described drawings indicate the same name portions, 10 and 11 indicate PON interface units (PON IF), and 12 indicates a monitoring unit. The PON interface unit 10 of the optical coupler unit 3 receives ONUs 2-1 to 2-n according to an abnormality notification when the light detection units 4-1 to 4-n detect continuous light emission failures of the ONUs 2-1 to 2-n. An OAM (Operations, Administration and Maintenance) frame having an optical signal wavelength different from the transmission optical signal wavelength is formed, wavelength-multiplexed with respect to the optical signals from the ONUs 2-1 to 2-n, and transmitted to the OLT 1. The PON interface unit 11 of the OLT 1 transfers an OAM frame from the PON interface unit 10 of the optical coupler unit 3 to the monitoring unit 12, identifies a continuous light emission failure occurrence ONU, and includes a repair process including a transmission stop by dispatching maintenance personnel, etc. By performing the above, other normal ONU transmission / reception processing can be started.

  FIG. 6 is an explanatory diagram of a sixth embodiment of the present invention. The same reference numerals as those in the above-mentioned respective drawings indicate the same names, and have substantially the same configuration as the fifth embodiment shown in FIG. From the interface unit (PON IF) 13, an OAM frame including a continuous light emission failure occurrence code (light emission abnormality code) and an ONU identifier (ONU ID) having a wavelength different from the wavelength of the optical signal transmitted from the ONU side to the OLT side An optical signal is transmitted to the OLT (not shown) via the optical coupler 8. The OLT receives the OAM frame, identifies the ONU in which the continuous light emission failure has occurred, and performs repair processing including transmission stop by dispatching maintenance personnel, etc. to start other normal ONU transmission / reception processing Can do.

  FIG. 7 is an explanatory diagram of Embodiment 7 of the present invention, where the OLT 1 shows only the PON interface unit (PON IF) 11, the OAM analysis unit 13, and the monitoring control unit 14, and the optical coupler unit 3 is a PON interface unit. Only (PON IF) 13 is shown. The OAM frame transmitted from the PON interface unit 13 of the optical coupler unit 3 includes a continuous light emission failure occurrence code (light emission abnormality code) and an ONU identifier (ONU ID). The OLT 1 converts the OAM frame into a PON interface unit. 11, and is analyzed by the OAM analysis unit 13, and the analysis result is transferred to the monitoring control unit 14. The monitoring controller 14 displays the continuous light emission failure occurrence ONU information and notifies the maintenance personnel, so that the maintenance personnel can quickly repair the failure occurrence ONU and return to the normal state.

  FIG. 8 is an explanatory diagram of an eighth embodiment of the present invention, showing only the main parts similar to those in FIG. 5. The PON interface unit 10 is a photodetecting unit 4-1 corresponding to ONUs 2-1 to 2-n. The abnormality notification frame selected in advance is formed based on the abnormality notification in which the occurrence of the continuous light emission failure is detected by ˜4-n, and transmitted to the OLT 1 by wavelength multiplexing of the optical signal as in the above-described embodiments. The OLT 1 is received by the PON interface unit 11, extracts an abnormality notification frame by wavelength separation, and transfers it to the monitoring unit 12. The monitoring unit 12 analyzes the abnormality notification frame, displays the continuous light emission failure occurrence ONU information, and notifies the maintenance personnel so that the maintenance personnel can quickly repair the failure occurrence ONU and return to the normal state. Can be made.

  FIG. 9 is an explanatory diagram of a ninth embodiment of the present invention, showing the main parts of the ONUs 2-1 to 2-n and the optical coupler unit 3, and the monitoring unit 6 before the PON interface unit 10 in FIG. And the continuous light emission failure occurrence detection signals from the light detection units 4-1 to 4-n corresponding to the ONUs 2-1 to 2-n are transferred to the monitoring unit 6, and the PON interface unit 10 and the optical coupler 8 are A case where an abnormality notification frame is transmitted as a wavelength multiplexed optical signal to the OLT (not shown) is shown. As an example of the configuration of the abnormality notification frame in this case, the header part code (unique code) indicating the abnormal notification frame, the code indicating the abnormal light emission state (light emission abnormality code), and the ONU of the abnormal light emission state Can be configured to include an ONU identifier (ONU ID). In the OLT (not shown), the abnormality notification frame is received and the ONU in the abnormal light emission state can be identified, so that the repair process can be quickly performed by maintenance personnel.

  FIG. 10 is an explanatory diagram of a tenth embodiment of the present invention. The OLT 1 shows only the main configuration of the PON interface unit (PON IF) 11, the monitoring control unit 14, and the switch unit (SW unit) 15. The coupler unit 3 shows only the PON interface unit (PON IF) 10. The switch unit 15 of the OLT 1 notifies the OLT 1 of the occurrence of the continuous light emission failure detected by the optical coupler unit 3 by the abnormality notification frame as described in the above embodiments. When the switch unit 15 identifies the code (unique code) indicating the abnormality notification frame in the header part of the abnormality notification frame, the switch unit 15 transfers the abnormality notification frame to the monitoring control unit 14. The monitoring control unit 14 identifies and displays the ONU in the abnormal light emission state notified by the abnormality notification frame, and notifies the maintenance personnel. Thereby, it is possible to quickly repair the ONU in an abnormal light emission state by maintenance personnel.

  FIG. 11 is an explanatory diagram of Embodiment 11 of the present invention, in which 1 is an OLT, 2-1 to 2-n are ONUs, 3 is an optical coupler unit, 4 is a light detection unit, and 9-1 to 9-n are An optical switch (optical SW), 16 is an optical switch control unit (optical SW control unit), and 17 is a personal computer (personal computer). In this embodiment, any one of the optical switches 9-1 to 9-n provided in the optical coupler unit 3 is controlled by the optical switch control unit 16 that receives a control command from the personal computer 17, and the ONU2- The optical signals from 1 to 2-n are selected and input to the light detection unit 4. As described above, the light detection unit 4 determines whether or not the optical signal from the selected ONU is in a continuous light emission failure state. In the case of the continuous light emission failure, as shown in the above-described embodiments, Anomaly is notified to OLT1. Alternatively, as in the ninth embodiment illustrated in FIG. 9, the light detection units 4-1 to 4-n corresponding to the ONUs 2-1 to 2-n are provided, and the light detection units 4-1 to 4-n are performed by the personal computer 17. Alternatively, the detection output signals may be sequentially selected to determine whether or not they are normal.

  FIG. 12 is an explanatory diagram of a twelfth embodiment of the present invention, showing ONUs 2-1 to 2-n and an optical coupler unit 3. The optical coupler unit 3 is an optical switch (ONUs 2-1 to 2-n) (Optical SW) 9-1 to 9-n, the light detection unit 4, the operation interface unit (operation IF) 18, the optical coupler control unit 19, and the interface unit 7 will be described. The operation interface unit 18 selectively controls the optical switches 9-1 to 9-n via the optical coupler control unit 19, and inputs the upstream optical signals from the ONUs 2-1 to 2-n to the light detection unit 4. A detection signal from the light detection unit 4 is input to the optical coupler control unit 19 to determine whether or not there is a continuous light emission failure. It is identified whether the ONUs 2-1 to 2-n selected by the optical switches 9-1 to 9-n are normal or has a continuous light emission failure, and the identification result is obtained from the operation interface unit 18 and the interface unit 7. Is displayed on one or both of these. As a result, the maintenance staff identifies the ONU when a continuous light emission failure occurs and executes the repair process.

  FIG. 13 is an explanatory diagram of a thirteenth embodiment of the present invention. In FIG. The PON interface and monitoring control unit 20 selectively controls the optical switches (optical SW) 9-1 to 9-n corresponding to the ONUs 2-1 to 2-n, and controls the optical detection units 4 to turn ONUs 2-1 to 2-n. n transmission optical signals are input, and a detection signal from the light detection unit 4 is input to the PON interface and the monitoring control unit 20. Accordingly, it is possible to determine whether there is a continuous light emission failure and the ONUs 2-1 to 2-n when the continuous light emission failure occurs, and notify the OLT 1 of the ONU information of the continuous light emission failure occurrence as an optical signal OAM frame. it can. The OLT 1 can be transferred to the monitoring control unit 14 via the PON interface unit 11 to notify maintenance personnel.

  FIG. 14 is an explanatory diagram of Embodiment 14 of the present invention, showing the ONUs 2-1 to 2-n and the optical coupler unit 3, and omitting the illustration of the OLT. This optical coupler unit 3 shows a light detection unit 4, optical switches (optical SW) 9-1 to 9-n, and a monitoring control unit 21, and the monitoring control unit 21 is a PON interface unit (PON IF unit) 22. And an optical switch control unit (optical SW control unit) 23 and a monitoring unit 24. The PON interface unit 22 of the monitoring control unit 21 is changed from the OLT (not shown) to the ONUs 2-1 to 2-n. It has a function of receiving a control frame to be transmitted at a timing assigned to the monitoring control unit 21 different from the assigned reception timing, and transmitting an OAM frame to the OLT at a timing assigned to the monitoring control unit 21. The control frame indicates a case including a code indicating optical switch switching (optical SW switching code) and an ID (ONU ID) indicating ONU selected by optical switch switching, and the OAM frame includes ONUs 2-1 to 2-n. And the ONU identifier (ONU ID) are notified to the OLT by the OAM frame when the continuous light emission failure occurrence is detected. In this case, the control frame is used to specify ONUs or sequentially select ONUs 2-1 to 2-n connected to the optical coupler unit 3. In accordance with such an instruction from the OLT, the optical switches 9-1 to 9-n are controlled from the optical switch control unit 23, and the transmission optical signals of the ONUs 2-1 to 2-n are input to the light detection unit 4.

  The ONU transmission optical signal selected by the optical switches 9-1 to 9-n is input to the light detection unit 4, and the light detection signal is input to the monitoring unit 24. The illustrated state shows a state in which the optical switch 9-1 is switched to input the transmission optical signal of the ONU 2-1 to the light detection unit 4. The monitoring unit identifies whether the light detection signal from the light detection unit 4 is based on the designated transmission timing or the continuous light emission state, and notifies the PON interface unit 22 in the case of the continuous light emission state. . The PON interface unit 22 forms an OAM frame and transmits an OAM frame of an optical signal at a transmission timing designated by the ONU. Therefore, on the OLT side, a plurality of ONUs 2-1 to 2-n connected via the optical coupler unit 3 by the control frame are sequentially designated or specific ONUs are designated to test whether they are normal. The test result can be received by the OAM frame, and remote monitoring is possible in the OLT.

  FIG. 15 is an explanatory diagram of a fifteenth embodiment of the present invention, showing the OLT 1 and the optical coupler unit 3, and a plurality of ONUs connected to the optical coupler unit 3 are not shown. The optical coupler unit 3 shows only the PON interface unit 22, and other components are not shown. The OLT 1 shows a PON interface unit 11, an OAM generation / analysis unit 21, and a monitoring control unit 14, and the other components are not shown. This embodiment shows a case in which the PON interface unit 22 of the optical coupler unit 3 is handled in the same manner as an ONU on the OLT 1 side. Accordingly, the transmission / reception timing from the OLT 1 to the PON interface unit 22 of the optical coupler unit 3 is illustrated. Allocation is performed in the same manner as a plurality of ONUs in which is omitted. Thereby, the control information (optical SW switching code) of the optical switch including the ONU identifier (ONU ID) by the OAM frame from the OLT 1 is received, and the test result based on the control result is displayed as the light emission abnormality code (light emission abnormality code) and the ONU. The OAM frame including the identifier (ONU ID) can be transmitted to the OLT 1.

  FIG. 16 is an explanatory diagram of Embodiment 16 of the present invention. The same reference numerals as those in the embodiment shown in FIG. 13 denote the same names, and the transmission optical signals from the ONUs 2-1 to 2-n to the OLT 1 are represented by PON. Interface and monitoring control unit (PON IF & monitoring control unit) 20 inputs to optical detection unit 4 via optical switches (optical SW) 9-1 to 9-n that are selectively controlled by dotted line paths, and detection by optical detection unit 4 The signal is input to the PON interface and monitoring control unit 20. As a result, it is possible to determine the presence or absence of continuous light emission failure and the ONUs 2-1 to 2-n when the continuous light emission failure occurs, and to notify the OLT 1 of ONU information on the occurrence of continuous light emission failure using the abnormality notification frame. . The OLT 1 can transfer to the monitoring control unit 14 via the PON interface unit 11 and notify the maintenance personnel of the continuous light emission failure occurrence ONU.

  FIG. 17 is an explanatory diagram of a seventeenth embodiment of the present invention, showing the same parts as those shown in FIG. 14. The optical coupler unit 3 includes a light detection unit 4 and optical switches 9-1 to 9-n. The monitoring control unit 21 includes a PON interface unit (PON IF unit) 22, an optical switch control unit (optical SW control unit) 23, and a monitoring unit 24, and includes a monitoring control unit 21. The PON interface unit 22 of 21 receives an OAM frame transmitted from the OLT (not shown) at a timing assigned to the monitoring control unit 21 different from the reception timing assigned to the ONUs 2-1 to 2-n. A function of transmitting an abnormality notification frame to the OLT at the timing assigned to the control unit 21 is provided. The received OAM frame indicates a case where a code indicating optical switch switching (optical SW switching code) and an ID indicating ONU selected by optical switch switching (ONU ID) is shown, and an abnormality notification frame for transmission to the OLT Includes a code indicating it, a light emission abnormality code of ONUs 2-1 to 2-n, and an identifier (ONU ID) of the ONU in which abnormality has occurred, and notifies the OLT by an abnormality notification frame upon detection of continuous light emission failure. . In this case, the OAM frame is used to specify ONUs or sequentially select ONUs 2-1 to 2-n connected to the optical coupler unit 3. By controlling the optical switches 9-1 to 9-n from the optical switch control unit 23 in accordance with such an instruction from the OLT and inputting the transmission optical signals of the ONUs 2-1 to 2-n to the light detection unit 4, the ONU 2 The normality of −1 to 2-n is confirmed and the failure ONU is detected, and when a failure occurs, the OLT can be notified by an abnormality notification frame.

  FIG. 18 is an explanatory diagram of an embodiment 18 of the present invention, showing the OLT 1 and the optical coupler unit 3, and a plurality of ONUs are not shown. The optical coupler unit 3 shows only the PON interface unit 10 and other components are not shown. The OLT 1 includes a PON interface unit 11, a monitoring control unit 14, an OAM generation / analysis unit 21, a layer 2 switch ( L2SW) 25, and other components are not shown. The monitoring control unit 14 of the OLT 1 forms a link with the PON interface unit 10 provided in the optical coupler unit 3 via the layer 2 switch 25, and continuously emits ONUs from the PON interface unit 10 of the optical coupler unit 3. When a failure is detected, the OLT 1 is notified by an abnormality notification frame. The OLT 1 receives the abnormality notification frame by the PON interface unit 11, and the layer 2 switch 25 transfers the abnormality notification frame to the monitoring control unit 14. The monitoring control unit 14 identifies an ONU having a continuous light emission failure by using the abnormality notification frame, and issues an optical switch switching control instruction to the OAM generation / analysis unit 21. The OAM generation / analysis unit 21 generates an OAM frame including an optical switch switching code (optical SW switching code) and an ONU identifier (ONU ID), and sends the OAM frame to the optical coupler unit 3 via the PON interface unit 11. . The optical coupler unit 3 receives the OAM frame by the PON interface unit 10 and transmits optical switches 9-1 to 9-n corresponding to the ONU identifiers (see FIGS. 11, 12, 13, 14, and 17). Until the continuous light emission failure is repaired, the switching state continued to the light detection unit 4 side can be maintained, and transmission / reception of an optical signal by a normal ONU other than the ONU in which the continuous light emission failure occurs can be performed.

1 OLT (Optical subscriber line accommodation equipment)
2-1 to 2-n ONU (Optical subscriber line terminator)
3 Optical coupler part 4-1 to 4-n Photodetector part

Claims (7)

An optical transmission line is connected between the optical subscriber line accommodation apparatus and the plurality of optical subscriber terminals via an optical coupler unit, and each of the plurality of optical subscriber terminals is assigned to the optical subscriber line accommodation apparatus. PON that transmits an optical signal at a specified transmission timing, and transmits the optical signal from the optical subscriber line accommodating apparatus to the optical subscriber terminal by time multiplexing at a reception timing allocated to the optical subscriber terminal. In the system,
The PON system is characterized in that the optical coupler unit includes a light detection unit that detects a transmission optical signal corresponding to the optical subscriber terminal and can monitor whether or not a continuous light emission abnormality has occurred.   The optical coupler unit includes: an optical coupler that branches the transmission optical signal corresponding to the optical subscriber terminal; a light detection unit that inputs the transmission optical signal branched by the optical coupler; and a detection by the light detection unit The PON system according to claim 1, further comprising a monitoring unit that inputs a signal and determines whether or not the transmission light signal is due to a continuous light emission abnormality.   The optical coupler unit is an optical coupler that branches the transmission optical signal corresponding to the optical subscriber terminal, an optical switch that selectively switches the transmission optical signal branched by the optical coupler, and the optical switch that is selected by the optical switch. A light detection unit that inputs a transmission optical signal and switching control of the optical switch and a detection signal from the light detection unit are input to determine whether or not the transmission optical signal is due to a continuous light emission abnormality. The PON system according to claim 1, further comprising a monitoring unit configured to perform monitoring.   The monitoring unit includes a PON interface unit that notifies the optical subscriber line accommodation apparatus by an OAM frame or an abnormality notification frame to which information indicating an optical subscriber terminal in which the continuous light emission abnormality has occurred is added, upon detection of the continuous light emission abnormality. The PON system according to claim 1, wherein the PON system is provided. An optical transmission line is connected between the optical subscriber line accommodation apparatus and the plurality of optical subscriber terminals via an optical coupler unit, and each of the plurality of optical subscriber terminals is assigned to the optical subscriber line accommodation apparatus. PON that transmits an optical signal at a specified transmission timing, and transmits the optical signal from the optical subscriber line accommodating apparatus to the optical subscriber terminal by time multiplexing at a reception timing allocated to the optical subscriber terminal. In the system,
The optical coupler unit inputs an optical switch that selectively switches the transmission optical signal from the optical subscriber terminal and the transmission optical signal selected by the optical switch, and monitors whether there is a continuous light emission abnormality. A PON system comprising: a light detection unit; and an optical switch control unit that selectively controls the optical switch by an external control input.   The optical coupler unit is an optical switch control unit that selectively controls the optical switch, and a monitoring unit that monitors the presence or absence of a continuous light emission abnormality by an output signal of a light detection unit that inputs the transmission optical signal by the selection control of the optical switch. And a PON interface unit for sending an OAM frame or an abnormality notification frame to which information indicating the optical subscriber terminal in which the continuous light emission abnormality has occurred is transmitted to the optical subscriber line accommodation device by detecting the continuous light emission abnormality by the monitoring unit. The PON system according to claim 5, further comprising a monitoring control unit configured to include the monitoring control unit.   The subscriber line accommodation apparatus is provided with a monitoring control unit that performs a selection control instruction of the optical switch of the optical coupler unit and receives and processes information of a subscriber terminal in which a continuous light emission abnormality has occurred. Item 6. The PON system according to Item 5.

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