JP3967346B2 - Optical line abnormality diagnosis device - Google Patents

Description

  The present invention relates to an optical line abnormality diagnosis apparatus for diagnosing an optical line abnormality in an optical communication network in which a transmission device of a communication station and an optical terminal at each user's house are connected via an optical line via an optical line.

  As shown in FIG. 7, an FTTH (Fiber to the Home) type optical communication network in which a communication station and each user's home are connected by an optical line such as an optical fiber via an optical branching unit (PON). It is configured.

  For example, the downstream optical signal a having a wavelength of 1.55 μm output from the transmission device 2 installed in the communication station 1 of the communication carrier is transmitted, for example, near the user's home via the optical line 3 made of an optical fiber. The light enters the optical branching device 4 attached to the installed power pole. The downstream optical signal a from the transmission device 2 incident on the optical branching device 4 is branched into a plurality of downstream optical signals a and respectively incident on the user's home 6 via each optical line 5 made of an optical fiber or the like. . The downstream optical signal a incident on each user home 6 is incident on an optical terminal (ONU) 7. The optical terminal 7 converts the incoming downstream optical signal a into an electrical signal c and sends it to each information terminal 8 such as a PC.

  The electrical signal c addressed to the communication station 1 output from the information terminal 8 at each user home 6 is converted into an upstream optical signal b having a wavelength of 1.31 μm at the optical terminal 7. The upstream optical signal b output from the optical terminal 7 enters the optical branching device 4 via the optical line 5. The optical branching unit 4 combines the upstream optical signals b incident from the optical line 5 and sends them to the communication station 1 via the optical line 3. Each upstream optical signal b having a wavelength of 1.31 μm input into the communication station 1 enters the transmission apparatus 2.

  In the optical communication network having such a configuration, the optical lines 5 are connected to the middle positions of the optical lines 5 made of optical fibers that connect the optical branching devices 4 and the user homes 6 so as to mechanically sandwich the optical lines 5. In many cases, a mechanical splice 9 is provided.

  FIG. 8 is a diagram showing a detailed configuration in the user home 6. The optical terminal 7 includes, for example, an optical transmission / reception unit 7a and an interface circuit 7b including a photoelectric conversion unit. The optical line 5 from the optical branching device 4 is connected to one end of an optical line 11 made of an optical fiber in the user's house 6, and the end of the optical line 11 is connected to the optical terminal 7 via a connector 12. In general, the length of the optical line 11 in the optical terminal 7 is set longer than the required length assuming that the installation position of the optical terminal 7 is changed in the user's home 6, so that as shown in the figure, It is stored in a state of being wound with a certain radius (curvature) or more. Further, the mechanical splice 9 described above may be provided in the middle of the optical line 11.

  In the optical communication network having such a configuration, for example, a single user reports that information communication with the transmission device 2 of the communication station 1 cannot be performed normally at the information terminal 8 of the user's home 6. Suppose that it is input to the administrator of the communication station 1.

  The administrator of the communication station 1 first investigates the cause of the failure to properly perform this information communication on the communication station 1 side.

  First, the transmission device 2 of the communication station 1 is driven, and a loopback test is performed using a normal optical communication signal for the optical terminal 7 of the user's home 6 where information communication with the transmission device 2 cannot be normally performed. If this loopback test is normal, it is estimated that the information terminal 8 at the user home 6 is abnormal.

  When the return test is abnormal, the optical terminal 7 of the user's home 6 where the information communication cannot be performed normally, or the optical lines 3, 5, 11 for connecting the communication station 1 and the optical terminal 7 of the user's home 6, the optical branching unit 4 or the mechanical splice 9 is considered to be abnormal, and an optical pulse d is sent from the optical pulse tester (OTDR) provided in the communication station 1 to the optical lines 3, 5, 11. The wavelength of the optical pulse d is set to 1.65 μm, which is longer than the wavelength 1.55 μm of the downstream optical signal a used for the optical communication and the wavelength 1.31 μm of the upstream optical signal b.

  The optical pulse tester receives the return light from the optical lines 3, 5, 11 composed of the back scattered light of the optical pulse d and the Fresnel reflected light, and the time change of the light intensity of the return light, that is, the communication station 1. The optical line characteristic indicating the characteristic of the distance change from And it is estimated that the abnormality has occurred in the distance position of the discontinuous part in this optical line characteristic.

  The detailed configuration and detailed operation of the optical pulse tester are disclosed in Patent Document 1.

  Next, the administrator (tester) of the communication station 1 investigates the reason why information communication with the transmission apparatus 2 shown below cannot be performed normally on the user home 6 side.

  The presence or absence of lighting of the light receiving lamp provided in the optical terminal 7 of the user home 6 is examined.

  The connector 12 at the end of the optical line 11 in the user's house 6 shown in FIG. 8 is disconnected from the optical terminal 7 and an optical power measuring device is connected to the connector 12 at the end of the optical line 11. Then, the light intensity of the optical communication signal from the transmission device 2 of the communication station 1 is measured. When the light intensity is normal, it is estimated that the optical terminal 7 or the information terminal 8 at the user home 6 is abnormal.

  The connector 12 at the end of the optical line 11 in the user home 6 shown in FIG. 8 is removed from the optical terminal 7, and the visible light source device is connected to the connector 12 at the end of the optical line 11. The visible light source device makes visible light such as red enter the optical lines 11, 5, 3 from the end of the optical line 11. The tester visually observes whether or not visible light such as red has reached each position including the mechanical splice 9 position of the optical line 11 in the user's home 6, and detects an abnormal part (abnormality occurrence range). Perform an inspection.

  The connector 12 at the end of the optical line 11 in the user's house 6 shown in FIG. 8 is removed from the optical terminal 7, and the light source device for contrast measurement is connected to the connector 12 at the end of the optical line 11. The light source device for core line contrast measurement makes the light for core line contrast measurement enter the optical lines 11, 5 and 3 from the end of the optical line 11. The tester attaches a portable core wire contrast device (ID tester) to each position of the optical lines 11, 5, and 3 to determine whether or not the light for core wire contrast measurement reaches the corresponding position. And verify the range of occurrence of abnormalities.

  The connector 12 at the end of the optical line 11 in the user's house 6 shown in FIG. 8 is removed from the optical terminal 7, and an optical pulse tester is connected to the connector 12 at the end of the optical line 11. Then, an optical pulse is transmitted from the optical pulse tester (OTDR) to the optical lines 11, 5 and 3. The optical pulse tester receives the return light from the optical lines 11, 5, and 3, and shows the temporal change in the light intensity of the return light, that is, the characteristics of the distance change from the end of the optical line 11 in the user's home 6. Get optical line characteristics. And it is estimated that the abnormality has occurred in the distance position of the discontinuous part in this optical line characteristic.

Then, as a result of the investigation of the cause explained above, when the abnormality occurrence position in the optical lines 11, 5, 3 is specified, measures against the abnormality are implemented. Specifically, measures are taken such as connection of cut points, replacement of the optical line in the section where the abnormality occurred, and return of the bent part.
JP 2001-74598 A

  However, even in the abnormality occurrence search method for examining the abnormality occurrence positions (abnormality occurrence sections) of the optical lines 3, 5, and 11 in the optical communication network by the above-described methods, there are the following problems that should still be improved.

  That is, in the technique of transmitting the optical pulse d from the optical pulse tester (OTDR) provided in the communication station 1 to the optical lines 3, 5 and 11 and measuring the optical line characteristics, the obtained optical line characteristics are obtained. Since the components of the return light from the plurality of optical lines 5 and 11 branched by the optical branching device 4 are combined, it is possible to determine which optical line 5 or 11 has an abnormality. Hateful.

  Further, in the method of checking the abnormality occurrence position (abnormality occurrence section) of the optical lines 11, 5, 3 from the user home 6 side where information communication with the transmission device 2 of the communication station 1 cannot be normally performed, The connector 12 at the end of the optical line 11 is removed from the optical terminal 7 and an optical power measuring device is connected to the connector 12 at the end of the optical line 11 to measure the light intensity of the optical communication signal.

  When the measurement of the light intensity is completed, the optical power measuring device is removed and a visible light source device is connected instead. When the visual inspection is completed, the visible light source device is removed and, instead, a light source device for contrast measurement is connected. When the inspection using the core wire contrast device is completed, the light source device for core wire contrast measurement is removed and, instead, an optical pulse tester is connected to measure the optical line characteristics from the user home 6 side.

  Thus, each time each measurement and each inspection is performed, it is necessary to reconnect each light source device, each measurement device, and each tester necessary for the connector 12 at the end of the optical line 11, and after the connection, Since adjustment is also necessary, the work of examining the abnormality occurrence positions (abnormality occurrence sections) of the optical lines 3, 5, and 11 becomes very complicated, and the inspection work efficiency is greatly reduced.

  In addition, since it is necessary to carry in a large number of light source devices, measuring devices, and testers to the user's house 6, it takes a lot of labor and time to carry in and remove these.

The present invention has been made in view of such circumstances, and a single device includes a light receiver, a plurality of light sources, and a plurality of functions for inspecting an abnormality in the optical path from the user's home side to the communication station side. By incorporating it, connection replacement work can be omitted, and the diagnosis operator can efficiently grasp the location (abnormality occurrence section) of the abnormality with a simple operation, reducing the overall equipment cost for inspecting the optical line abnormality. An object of the present invention is to provide an optical line abnormality diagnosis device that can be easily carried to a user's home and can be reduced in size and weight.

The present invention provides a connector for connecting a transmission device of a communication station and an optical terminal at a user's home via an optical line, and allowing the optical terminal end of the optical line to be detachably attached to the optical terminal. 12) is an optical line abnormality diagnosing device for diagnosing an optical line abnormality in the optical communication network attached with 12) from the user's home side through a connector removed from the optical terminal and attached to the self apparatus .

In this optical line abnormality diagnosis apparatus, a laser light source that outputs an optical signal, a light receiver that receives light input through a connector, and light from a user's home via an optical line from a transmission apparatus of a communication station. An optical communication signal transmitted to the terminal is received by a light receiver through a connector, and an optical communication signal intensity measuring unit for measuring the optical intensity of the optical communication signal is output from the laser light source to the optical line through the connector. Optical fiber output from the laser light source is output to the optical line via the connector, and the optical signal output from the optical line is output to the optical line via the connector. The optical line characteristic measuring unit that calculates the optical line characteristic by measuring the intensity of the return light, and the optical communication signal intensity measuring unit, the core line contrast measuring unit, and the optical line characteristic measuring unit are selected for the selection operation. Depending on the individual or order The drive unit and each measurement unit specified by this operation unit are driven and controlled, the output light of the laser light source is controlled to the optical signal of the specified measurement unit, and the light receiving sensitivity of the receiver is also controlled by the specified measurement unit And a control unit for controlling to a corresponding sensitivity. Furthermore, the optical communication signal strength measurement, the core wire contrast measurement, and the optical line characteristic measurement can be performed without changing the connection to the optical line connector attached to the self apparatus.

In the optical line abnormality diagnosis apparatus configured as described above, an optical communication signal intensity measurement unit that evaluates the optical intensity of the optical communication signal from the transmission apparatus of the communication station, The apparatus includes a core line contrast measuring unit that outputs line contrast measuring light and an optical line characteristic measuring unit (function of an optical pulse tester) that obtains optical line characteristics of an optical pulse.

Then, in order to enable each of the measurement units to be sequentially performed in a state where the optical line abnormality diagnosis apparatus is connected to the end of the optical line instead of the optical terminal, that is, in a state where the connection is not changed, a laser light source is used. The optical fiber for measuring the optical fiber and the optical line characteristic measurement light are commonly used, and the optical receiver is commonly used for the optical communication signal intensity measurement and the optical line characteristic characteristic measurement.

  Therefore, it is possible to omit the connection switching work for each different inspection (measurement), and for the diagnosis operator, the abnormality occurrence position (abnormality occurrence section) can be efficiently grasped by a simple operation, and the optical line abnormality is inspected. Can reduce the overall equipment cost.

Further, Oite to another invention, the optical line abnormality diagnosis apparatus, an optical communication signal strength measurement, core control measurement, and an optical line characteristics measurement, in accordance with the selection operation, the operation going specified alone or sequentially A laser light source that outputs a light beam for measuring the optical fiber line characteristic, and outputs a light pulse for measuring the optical line characteristic when the optical line characteristic is measured, and a receiver that receives the light input through the connector. A bias setting circuit that sets the light receiving sensitivity of the receiver to a sensitivity corresponding to the specified measurement item, and the light output from the laser light source is output to the optical line via the connector and input via the connector. An optical coupler that outputs light to the light receiver, an A / D converter that converts the output signal of the light receiver to a digital signal, and the modulation frequency and light pulse of the laser light source according to the measurement items specified in the operation unit Occurrence timing and A timing generator for setting a clock signal to the A / D converter and a digital signal corresponding to the incident optical signal output from the A / D converter are received, and when the optical communication signal is measured, the light reception level of the optical communication signal is set. A data processing unit that calculates and calculates the temporal change of the light intensity of the return light when measuring the optical line characteristics, and a laser light source, a bias setting circuit, a timing generation unit, and data processing according to the measurement item specified by the operation unit A control unit that drives and controls the unit. Furthermore, the optical communication signal intensity measurement, the core wire contrast measurement, and the optical line characteristic measurement can be performed without changing the connection to the optical line connector attached to the self apparatus.

Further, in another invention, in the optical line abnormality diagnosis device according to the invention described above, the operation unit designates visual measurement alone or sequentially in addition to each measurement. A visible light source that outputs visible light; and an optical switch that switches light output to the optical line via the connector to light from the visible light source and light from the laser light source. Further, the control unit drives and controls the visible light source during visual measurement, and switches the optical switch to the visible light source side to output visible light to the optical line.

In the optical line abnormality diagnosis apparatus of the present invention, a light receiver, a plurality of light sources, and a plurality of functions for inspecting abnormality of the optical line from the user's home side to the communication station side are incorporated in one apparatus.

  Therefore, connection change work can be omitted, and the diagnosis operator can efficiently grasp the location (abnormality occurrence section) of the abnormality with a simple operation, and costs such as labor costs and equipment costs for inspecting the optical line abnormality. Can be saved, and it is possible to contribute to the maintenance and improvement of communication quality by identifying the failure of the optical line at an early stage. Furthermore, carrying to a user's house becomes easy by size reduction and weight reduction.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing a schematic configuration of an optical communication network to which an optical line abnormality diagnosis device according to an embodiment of the present invention is applied. The same parts as those in the optical communication network shown in FIG.

  In FIG. 1, the connector 12 at the end of the optical line 11 in the user's home 6 where the information communication between the information terminal 8 and the transmission device 2 of the communication station 1 cannot be performed normally is removed from the optical terminal 7. The optical line abnormality diagnosis device 13 of the embodiment is connected to the terminal connector 12 at 11.

  FIG. 2 is a block diagram showing a schematic configuration of the optical line abnormality diagnosis device 13. The control unit 14 composed of a computer is based on the measurement conditions instructed by the diagnostic operator from the operation unit 15 and the following four inspection items, the data processing unit 16, the timing generation unit 17, the optical switch 18, the bias setting circuit 19, Each operation of the amplifier 20 is controlled. Furthermore, the control unit 14 can perform the inspection items in conjunction with each other and display the measurement results as a list or a partial display.

Inspection item 1 ... Optical communication signal light intensity measurement Inspection item 2 ... Visible light output Inspection item 3 ... Optical output for core line contrast measurement Inspection item 4 ... Optical line characteristic measurement The laser light source (LD) 24 drives the LD drive circuit 23. Based on the current, light having a wavelength of 1.31 μm or 1.55 μm is output. The visible light source (VLD) 26 outputs red continuous visible light having a wavelength of 0.635 μm or 0.650 μm based on the drive current of the VLD drive circuit 25.

  A light receiver 29 composed of an APD (avalanche photo diode) whose light receiving sensitivity (gain) can be adjusted by a bias setting circuit 19 is incident on the optical line abnormality diagnosis device 13 with return light from the optical communication network. The light separated by the optical coupler 28 is received, converted into an electrical signal, and sent to the amplifier 20. The amplifier 20 amplifies the electric signal and sends it to the A / D converter 22. The A / D converter 22 converts the electrical signal into a digital electrical signal and sends it to the data processing unit 16.

  In the data processing unit 16, an optical communication signal light intensity detection unit 30 in the inspection item 1 “optical communication signal light intensity measurement” is provided. The optical communication signal light intensity detection unit 30 obtains the optical communication signal light intensity using the signal level of the digital electrical signal input from the A / D converter 22, and displays the output on the display 21 via the control unit 14. To do.

  Further, in the data processing unit 16, an optical line characteristic calculation unit 31 in the inspection item 4 “optical line characteristic measurement” is provided. The optical line characteristic calculation unit 31 calculates the optical line characteristic 39 shown in FIG. 3 using the time-series signal level of the digital electric signal input from the A / D converter 22, and passes through the control unit 14. A display is output on the display 21.

  The timing generation unit 17 determines the generation timing of an optical pulse for measuring the optical line characteristic 39, supplies a clock signal to the A / D converter 22, sets the modulation frequency of the optical fiber for measurement of the core wire, and the like. .

  Next, an example of a specific procedure when the control unit 14 actually performs each of the inspection items 1 to 4 will be described in order.

Inspection item 1... Optical communication signal light intensity measurement The control unit 14 stops the LD drive circuit 23 and the VLD drive circuit 25 and transmits light from the optical line abnormality diagnosis device 13 through the connector 12 to the light beam in the user home 6. Do not output to path 11. In this state, an optical communication signal transmitted from the transmission device 2 of the communication station 1 to the optical terminal 7 of the user home 6 via the optical lines 3, 5, 11 is received via the optical switch 18 and the optical coupler 28. The light is incident on the container 29. The optical communication signal received by the light receiver 29 is converted into an electric signal by the light receiver 29, amplified by the amplifier 20, A / D converted by the A / D converter 22, and optical communication in the data processing unit 16. The signal light intensity detector 30 calculates the optical communication signal light intensity. Then, it is determined whether or not the calculated optical communication signal light intensity satisfies a specified value, and the calculated optical communication signal light intensity and the determination result are displayed on the display 21.

Inspection item 2 .. Visible light output The control unit 14 activates the timing generation unit 17 and the VLD drive circuit 25 in a state where the LD drive circuit 23 is stopped, and sets the visible light source (VLD) 26 to 0.635 μm or 0. A continuous visible light having a red wavelength of 650 μm is output.

  Before the visible light output, the control unit 14 switches the setting of the light switch 18 to the visible light source (VLD) 26 side. The red visible light output from the visible light source (VLD) 26 is output to the optical lines 11, 5, 3 via the optical switch 18, the optical coupler 28, and the connector 12.

  The diagnostic practitioner visually observes whether red visible light reaches each position including the position of the mechanical splice 9 of the optical line 11 in the user's house 6 and the optical line 5 near the user's house 6. Inspect the abnormal part (abnormal range).

Test item 3... Optical output for core line contrast measurement The control unit 14 activates the timing generation unit 17 and the LD drive circuit 23 in a state where the VLD drive circuit 25 is stopped. Measurement light consisting of light having a wavelength of 31 μm or 1.55 μm is output. As the measurement light, the rectangular waveform core-line contrast measurement light 32 in FIG. 4A or the continuous waveform core-line contrast measurement light 32 in FIG. 4B is used. As the modulation frequency f of the core-line contrast measuring light 32 having a rectangular waveform in FIG. 4A, 270 Hz, 1 kHz, 2 kHz, etc. are adopted, and the duty ratio is 50%.

  Prior to the optical output for the core line contrast measurement, the controller 14 switches the setting of the optical switch 18 to the laser light source (LD) 24 side.

  The core line contrast measurement light 32 output from the laser light source (LD) 24 is output to the optical lines 11, 5, 3 via the optical switch 18, the optical coupler 28, and the connector 12.

  The diagnostic practitioner attaches the portable cord contrast device (ID tester) 33 shown in FIG. 5A to each position of the optical paths 11, 5, and 3, and the cord contrast measurement light 32 at the corresponding position. It is checked whether or not the error has occurred and the range of occurrence of abnormality is verified.

  As shown in FIG. 5 (a), the core wire contrast device (ID tester) 33 includes a bending tool 34 for bending the optical lines 11, 5, and 3 with a predetermined curvature R, and the bent optical lines 11, 5 3, a light detection circuit 35 that detects the core line contrast measurement light 32 leaking from 3, a determination circuit 36 that determines that the detected light intensity of the core line contrast measurement light 32 is equal to or higher than a specified value, and a determination result It is comprised with the indicator 37 which displays.

  In general, since the optical lines 11, 5, 3 are covered, the mounting position of the optical fiber contrast device (ID tester) 33 with respect to the optical lines 11, 5, 3 is as shown in FIG. 3 is an uncovered position on the utility pole 38 that supports 3. More specifically, as shown in FIG. 5 (b), a cord contrast device (ID tester) 33 is attached in order from the position of the utility pole 38 close to the user's home 6, and the cord contrast measurement light 32. The section in front of the position where the mark does not reach is defined as an abnormality occurrence range (section).

Inspection item 4 ... Optical line characteristic measurement The control unit 14 activates the timing generation unit 17 and the LD drive circuit 23 in a state where the VLD drive circuit 25 is stopped, and sets the laser light source (LD) 24 to 1.31 μm or 1 The optical pulse e shown in FIG. 3 made of .55 μm wavelength light is output at a constant period.

  Before the optical line characteristic measurement, the control unit 14 switches the setting of the optical switch 18 to the laser light source (LD) 24 side.

  The optical pulse e output from the laser light source (LD) 24 is output to the optical lines 11, 5, 3 via the optical switch 18, the optical coupler 28, and the connector 12. The return light from the optical lines 11, 5, 3 consisting of the backscattered light and the Fresnel reflected light of the light pulse e enters the light receiver 29 via the optical switch 18 and the optical coupler 28. The return light received by the light receiver 29 is converted into an electrical signal by the light receiver 29, amplified by the amplifier 20, A / D converted by the A / D converter 22, and optical line characteristics in the data processing unit 16. Input to the calculation unit 31.

  The optical line characteristic calculation unit 31 calculates the optical line characteristic 39 shown in FIG. 3 using the time-series signal level of the digital electric signal input from the A / D converter 22, and passes through the control unit 14. A display is output on the display 21. This optical line characteristic 39 indicates the characteristic of the change in the light intensity of the return light with time, that is, the change in the distance L from the end of the optical line 11 in the user's home 6.

  Then, as shown in FIG. 5 (c), the diagnostic operator expands the abnormality occurrence range (section) specified by “optical output for contrast control measurement” of the inspection item 3 in the displayed optical line characteristic 39. Then, a more detailed abnormality occurrence position is specified.

  In this optical line characteristic 39, it is difficult to detect an abnormality that occurs in the optical line 11 in the vicinity of the optical line abnormality diagnosis device 13 (dead zone). Furthermore, as shown in FIG. 8, when the optical line 11 is stored in a wound state, it is difficult to grasp the accurate distance position of the abnormal position. In such a case, an accurate abnormality occurrence position is specified in combination with the results of the other inspection items 1, 2, and 3.

  FIG. 6 is a flowchart showing the entire operation of the optical line abnormality diagnosis device 13 connected to the terminal connector 12 of the optical line 11 in the user home 6.

  When the optical line abnormality diagnosis device 13 is activated, the display 21 displays the start of “optical communication signal light intensity measurement” of the inspection item 1 (step S1). When the diagnosis operator inputs a measurement instruction via the operation unit 15 (S2), the light receiving sensitivity (gain) of the light receiver (APD) 29 is adjusted to the light intensity of the optical communication signal (S3). Then, the light intensity of the optical communication signal from the transmission device 2 of the communication station 1 is measured, it is determined whether or not the light intensity satisfies the specified value (S4), and the measurement result and the judgment result are displayed on the display 21. Output (S5).

  When the diagnostic practitioner instructs continuous measurement via the operation unit 15 (S6), the display 21 displays the start of “visible light output” of the inspection item 2 (S7). Then, the VLD driving circuit 25 and the visible light source (VLD) 26 are activated to output red visible light to the optical lines 11, 5, and 3 (S8). The diagnosis practitioner visually inspects the state of the optical line 11 in the user's house 6 and the optical line 5 near the user's house 6 to inspect the abnormal part (abnormality occurrence range) (S9).

  When the diagnosis practitioner instructs continuous measurement via the operation unit 15 (S10), the display 21 displays the start of the “cardiac line contrast measurement light output” (S11). Then, the LD drive circuit 23 and the laser light source (LD) 24 are activated to output the core line contrast measurement light 32 to the optical lines 11, 5, and 3 (S12). The diagnosis practitioner attaches the core wire contrast device (ID tester) 33 to each position of the optical lines 11, 5, and 3, and grasps whether or not the core wire contrast measurement light 32 reaches the corresponding position. Then, the abnormality occurrence range is verified (S13).

  When the diagnosis practitioner instructs continuous measurement via the operation unit 15 (S14), the display 21 displays the start of “optical line characteristic measurement” of the inspection item 4 (S15). Then, the light receiving sensitivity (gain) of the light receiver (APD) 29 is adjusted to the light intensity of the return light (S16). The LD driving circuit 23 and the laser light source (LD) 24 are activated to output the optical palace e to the optical lines 11, 5, and 3 (S17). The optical receiver 29 receives (measures) the return light (S18), and the optical line characteristic calculator 31 calculates the optical line characteristic 39 and outputs it to the display 21 (S19).

  In the optical line abnormality diagnosis device 13 configured as described above, the “optical communication signal light intensity measurement”, “visible light output”, and “core line contrast measurement light output” can be performed by one optical line abnormality diagnosis device 13. The four inspection items of “optical line characteristic measurement” can be implemented.

  In addition, one laser light source (LD) 24 is used in common for “light output for core line contrast measurement” and “optical line characteristic measurement”, and the light receiving sensitivity (gain) of the light receiver 29 is instructed from the control unit 14. Thus, the light receiver 29 is commonly used for “optical communication signal light intensity measurement” and “optical line characteristic measurement”.

  Accordingly, it is possible to omit the connection switching work for each different inspection (measurement), and for the diagnosis operator, the abnormality occurrence position (abnormality occurrence section) can be efficiently grasped by a simple operation, and the optical lines 11, 5, The overall cost for inspecting 3 abnormalities can be reduced.

  Further, in the optical line abnormality diagnosis method configured as described above, as described in the flowchart of FIG. 6, first, the light intensity of the optical communication signal from the transmission device 2 of the communication station 1 in the inspection item 1 is measured. To do. And when the optical communication signal beyond a regulation value has not arrived at the user's home 6, it is judged that there is an abnormality on the optical line 11, 5, 3 side, and then the optical line 11, 5, 3 in the inspection item 2 Visible light is output as light for visual inspection, and a diagnostic operator visually inspects the optical lines 11 and 5 in the user home 6 and in the vicinity of the user home 6.

  If no abnormalities can be clearly confirmed in the optical lines 11 and 5 by visual inspection, then the optical fiber 11 for measuring the core wire in the inspection item 3 is output to the optical lines 11, 5 and 3. The diagnostic practitioner wears the core wire contrast device 33 at each position shown in FIG. 5B of the optical paths 11, 5, and 3 inside the user home 6 and outside the user home 6, and for the core wire contrast measurement at the corresponding position. Whether or not the light 32 has arrived is grasped, and the abnormality occurrence range is verified.

  Finally, the return light measurement of the optical pulse in the inspection item 4 is performed, and as shown in FIG. 5C, the exact abnormality occurrence position within the abnormality occurrence range specified in the inspection item 3 on the optical line characteristic 39 is obtained. Identify.

  As described above, the four inspection items of “optical communication signal light intensity measurement”, “visible light output”, “core line contrast measurement light output”, and “optical line characteristic measurement” are executed in the order of items 1-4. As a result, an accurate abnormality occurrence position can be identified efficiently.

  In addition, if an accurate abnormality occurrence position can be specified on the way, it is possible to stop execution of subsequent inspection items.

In addition, this invention is not limited to embodiment mentioned above.
In the present embodiment, a case has been described in which either visible light or core-line contrast measurement light is selected by the optical switch 18 and output to the optical lines 11 and 5. However, the optical switch 18 is optically multiplexed. The maintenance worker visually inspects the transmission state of the visible light by outputting the visible light and the light for contrast measurement to the optical lines 11 and 5 at the same time. When a failure is found, the user can return to the user's home 6 again, and the state of the failure can be investigated in more detail using the core wire contrast device 33 without switching to the light for core wire contrast measurement.

  In the present embodiment, the case where the optical terminal (for example, the optical subscriber unit (Optical Network Unit; ONU)) is a network installed in the user's home 6, FTTH (Fiber To The Home) has been described. The present invention can also be applied to FTTC (Fiber To The Curb) and FTTB (Fiber To The Building).

  Furthermore, the present invention can also be applied to a communication method in which a transmission apparatus and a user's house are connected one-on-one like SS (Single Star).

The schematic diagram which shows schematic structure of the optical communication network to which the optical- path abnormality diagnosis apparatus of one Embodiment of this invention is applied. The block diagram which shows schematic structure of the optical-path abnormality diagnostic apparatus of the embodiment The figure which shows the optical line characteristic measurement which the optical line abnormality diagnostic apparatus of the embodiment performs The figure which shows the light for a core line contrast measurement output from the optical-path abnormality diagnostic apparatus of the embodiment Illustration of the structure and usage of the core contrast Flow chart showing the overall operation of the optical line abnormality diagnosis device of the same embodiment Schematic diagram showing the schematic configuration of a general optical communication network Schematic configuration diagram of user premises in the same optical communication network

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Communication station, 2 ... Transmission apparatus, 3, 5, 11 ... Optical line, 4 ... Optical splitter, 6 ... User's house, 7 ... Optical terminal, 8 ... Information terminal, 9 ... Mechanical splice, 12 ... Connector, 13 DESCRIPTION OF SYMBOLS ... Optical line abnormality diagnosis apparatus, 14 ... Control part, 15 ... Operation part, 16 ... Data processing part, 17 ... Timing generation part, 18 ... Optical switch, 19 ... Bias setting circuit, 20 ... Amplifier, 21 ... Display, DESCRIPTION OF SYMBOLS 22 ... A / D converter, 23 ... LD drive circuit, 24 ... Laser light source (LD), 25 ... VLD drive circuit, 26 ... Visible light source (VLD), 28 ... Optical coupler, 29 ... Light receiver, 30 ... Optical communication Signal light intensity detection unit, 31... Optical line characteristic calculation unit, 32... Optical fiber contrast measurement light, 33... Optical fiber contrast device (ID tester), 39.

Claims (3)

A connector (12) for connecting the transmission device of the communication station and the optical terminal at the user's home via an optical line, and for detaching the optical line end from the optical terminal at the optical terminal end of the optical line. An optical line abnormality diagnosing device for diagnosing an abnormality of the optical line in the attached optical communication network from the user's home side through the connector removed from the optical terminal and attached to the own device ,
A laser light source (24) for outputting an optical signal;
A light receiver (29) for receiving light input through the connector;
The optical communication signal transmitted from the transmission device of the communication station to the optical terminal at the user's home via the optical line is received by the light receiver via the connector, and the light intensity of the optical communication signal is measured. An optical communication signal intensity measurement unit (30);
A core contrast measuring unit that sends the core contrast measuring light output from the laser light source to the optical line via the connector;
The optical pulse output from the laser light source is output to the optical line via the connector, the return light from the optical line is received by the light receiver via the connector, and the intensity of the return light is determined. An optical line characteristic measuring unit (31) for measuring and calculating the optical line characteristic;
The operation unit (15) for designating the optical communication signal intensity measurement unit, the core line contrast measurement unit, and the optical line characteristic measurement unit individually or in sequence according to a selection operation;
Each of the measurement units designated by the operation unit is driven and controlled, the output light of the laser light source is controlled to the optical signal of the designated measurement unit, and the light receiving sensitivity of the light receiver is set to the designated measurement unit. A control unit (14) for controlling to a corresponding sensitivity;
With
An optical line abnormality characterized in that the optical communication signal strength measurement, the core line contrast measurement, and the optical line characteristic measurement can be performed without changing the connection to the optical line connector attached to the self-device. Diagnostic device. A connector (12) for connecting the transmission device of the communication station and the optical terminal at the user's home via an optical line, and for detaching the optical line end from the optical terminal at the optical terminal end of the optical line. An optical line abnormality diagnosing device for diagnosing an abnormality of the optical line in the attached optical communication network from the user's home side through the connector removed from the optical terminal and attached to the own device,
An operation unit (15) for designating optical communication signal intensity measurement, core line contrast measurement, and optical line characteristic measurement individually or sequentially according to the selection operation;
A laser light source (24) for outputting a core-line-contrast measurement light at the time of a core-line contrast measurement, and outputting an optical pulse for measuring an optical line characteristic at the time of measuring an optical line characteristic;
A light receiver (29) for receiving light input through the connector;
A bias setting circuit (19) for setting the light receiving sensitivity of the light receiver to a sensitivity corresponding to the designated measurement item ;
An optical coupler (28) for outputting the light output from the laser light source to the optical line via the connector and outputting the light input via the connector to the light receiver;
An A / D converter (22) for converting the output signal of the light receiver into a digital signal;
A timing generator (17) for setting a modulation frequency of the laser light source, a generation timing of an optical pulse, and a clock signal to the A / D converter according to a measurement item designated by the operation unit;
A digital signal corresponding to the incident optical signal output from the A / D converter is received, and a light reception level of the optical communication signal is calculated at the time of measuring the optical communication signal. A data processing unit (16) for calculating a temporal change in intensity;
A control unit (14) for driving and controlling the laser light source, the bias setting circuit, the timing generation unit, and the data processing unit according to a measurement item designated by the operation unit ,
An optical line abnormality characterized in that the optical communication signal strength measurement, the core line contrast measurement, and the optical line characteristic measurement can be performed without changing the connection to the optical line connector attached to the self-device. Diagnostic device. In addition to each of the above measurements, the operation unit also designates visual measurement alone or in turn,
A visible light source that outputs visible light; and a light switch that switches light output from the visible light source and light from the laser light source to light output to the optical line via the connector;
The control unit drives and controls the visible light source during visual measurement and switches the optical switch to the visible light source side to output the visible light to the optical line.
The optical line abnormality diagnosis device according to claim 2, wherein:

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