Failure location identification system, method, program, and marker for discriminating optical core wire

Abstract

The present invention pertains to a marker for discriminating an optical core wire, the marker being connected to an optical core wire that constitutes an optical network and exhibiting unique response characteristics when an optical pulse is applied. This marker for discriminating an optical core wire comprises an optical fiber, and achieves unique response characteristics by a combination of optical pulse response characteristics respectively imparted to sections defined by performing segmentation every length interval, along the length direction of the optical fiber, that corresponds to the resolution of a pulse tester for generating an optical pulse. The optical pulse response characteristics include response characteristics in which an optical pulse is attenuated and response characteristics in which an optical pulse is not attenuated. The response characteristics in which an optical pulse is attenuated are imparted by providing, to the sections, any one of a fusion point, a connector, or a bend. The unique response characteristics are expressed by a bit string in which numbers representing response characteristics in which an optical pulse is attenuated and numbers representing response characteristics in which an optical pulse is not attenuated are arranged in the order of the sections.

Description

System, method, program for identifying fault location, and optical fiber discrimination marker

[0001] The present invention relates to a system, a method, a program, and an optical fiber identification marker for identifying a fault location in a network that uses optical fiber, for example.

[0002] In optical networks that use optical fibers, the presence or absence of a fault and the location of the fault have conventionally been estimated by conducting tests using a test system equipped with a pulse tester.

[0003] In this type of test, a pulse tester injects an optical pulse into an optical fiber, and of the Rayleigh scattered light that occurs during this process, it extracts "backward scattered light" that returns to the input side and "Fresnel reflection" that occurs due to a sudden change in refractive index at a connection point, etc., to measure the state of the optical line. After the optical pulse is injected, the elapsed time and the level of the returned light are measured to measure optical loss and connection points, and the measurement results can also be used to identify the location of a break in the optical line.

[0004] When testing with a pulse tester, optical wavelengths for communication are used during construction, but optical wavelengths for testing are used during operation. This is because optical wavelengths for communication are used by users during operation. Therefore, to avoid affecting communications, optical wavelengths for communication are not used during operation, but optical wavelengths for testing are used.

[0005] If the pulse tester predicts that a fault exists, and if the predicted fault is a physical one, a maintenance technician will be sent to the fault location to carry out repair work. Therefore, it is essential to identify the fault location.

[0006] In tests using conventional pulse testers, the fault location can be identified based on the distance from the pulse tester when the communication path to be measured is uniquely determined, such as in a single star configuration, passive double star configuration, or single loop configuration.

[0007] For example, in a single star configuration, since there is only one communication path, the fault location can be uniquely identified by measuring the elapsed time and the level of the returned light and calculating the communication distance from the pulse tester.

[0008] Furthermore, although the single-loop configuration has two communication paths, the communication path under test can be identified as one path. Therefore, by measuring the elapsed time and the level of the returned light and calculating the communication distance from the pulse tester, the failure point can be uniquely identified.

[0009] "Search Method for Optical Fiber Faults," NTT Technical Journal, October 2006

[0010] However, conventional technology using pulse testers identifies the fault location from the communication distance. Therefore, while it is possible to uniquely identify the fault location in an optical network with only one communication path, it is unable to uniquely identify the fault location in an optical network with multiple communication paths, such as a multi-loop configuration.

[0011] FIG. 16 is a diagram showing an example of a multi-loop optical network configuration and a problem that arises when identifying a fault location.

[0012] The optical networks with multi-loop configurations illustrated in Figures 16(a) and 16(b) have the same configuration, and include a first-stage loop 14 formed by an optical core line and a second-stage loop 15 formed by an optical core line 12.

[0013] An intra-office device 20 and an off-site device 22 are provided along the loop 14. An off-site device 22 is provided along the loop 15. The off-site device 22 is connected to both the loop 14 and the loop 15, so that the first-stage loop 14 and the second-stage loop 15 are connected by the off-site device 22. A customer-operated on-site device 40 is connected to the loop 15.

[0014] In such a multi-loop configuration, point α (near the utility pole bb1 in town aa) in FIG. 16A and point β (near the utility pole yy2 in town xx) in FIG. 16B are located at the same communication distance from the pulse tester 200.

[0015] Therefore, with the conventional technology, even if a failure at point α is detected, it is not possible to identify the failure point as either point α or point β, and it is not possible to instruct the maintenance person as to the location.

[0016] The present invention has been made in consideration of these circumstances, and aims to provide a system, method, program, and optical core wire discrimination marker that can uniquely identify the fault point even in an optical network with multiple communication paths, such as a multi-loop optical network.

[0017] To achieve the above object, a first aspect of the present invention is an optical core wire discrimination marker that is connected to an optical core wire that constitutes an optical network and that exhibits a unique response characteristic when an optical pulse is applied thereto.

[0018] A second aspect of the present invention is a fault location method in which an optical core line discrimination marker of the first aspect applies an optical pulse to an optical network to identify a fault location in the optical network connected to each optical core line, and identifies an optical core line that responds indicative of a fault in response to the application of the optical pulse based on the unique response characteristic of the optical core line discrimination marker connected to this optical core line.

[0019] Furthermore, a third aspect of the present invention is a system for locating a fault location in an optical network made up of a plurality of optical core lines, comprising: an optical core line discrimination marker connected to each of the plurality of optical core lines and exhibiting a unique response characteristic when an optical pulse is applied; and a pulse tester that applies an optical pulse to the optical network and identifies an optical core line that responds indicative of a fault, based on the unique response characteristic from the optical core line discrimination marker connected to this optical core line.

[0020] Furthermore, a fourth aspect of the present invention is a program that enables a processor to implement the functions of applying an optical pulse to an optical network composed of a plurality of optical core lines, each of which is connected to an optical core line discrimination marker that exhibits a unique response characteristic when an optical pulse is applied, and identifying an optical core line that has responded indicative of a fault when an optical pulse is applied to the optical network, based on the unique response characteristic from the optical core line discrimination marker connected to this optical core line.

[0021] According to the present invention, it is possible to uniquely identify a failure point even in an optical network having a plurality of communication paths, such as an optical network with a multi-loop configuration.

[0022] FIG. 1 is a conceptual diagram showing an example of application of a fault location identification system to an optical network, to which a fault location identification method according to an embodiment of the present invention is applied. FIG. 2 is a conceptual diagram showing an example of the configuration of a fault location identification system according to an embodiment of the present invention. FIG. 3 is a conceptual diagram showing an example of the internal structure of an optical core cable discrimination marker. FIG. 4 is a diagram for explaining a unique response characteristic assigned to the optical core cable discrimination marker. FIG. 5 is a waveform showing an example of a response characteristic. FIG. 6 is an example of an external view of an optical core cable discrimination marker on which a decimal identifier portion is displayed. FIG. 7 is a diagram showing an example of assigning a response characteristic to an optical core cable discrimination marker using fusion. FIG. 8 is a diagram showing a state in which the optical fiber shown in FIG. 7(b) is housed in a housing. FIG. 9 is an example of an external view of an optical core cable discrimination marker on which the identifier "175" is displayed on the outer surface of the housing. FIG. 10 is a diagram showing an example of assigning a response characteristic to an optical core cable discrimination marker using a connector. FIG. 11 is a diagram showing a state in which the optical fiber shown in FIG. 10(b) is housed in a housing. Fig. 12 is a diagram showing an example of using bending to impart a response characteristic to an optical fiber discrimination marker. Fig. 13 is a diagram showing the state in which the optical fiber shown in Fig. 12(b) is housed in a housing. Fig. 14 is an example of a waveform that includes a response F indicating a fault in addition to the response characteristic R specific to the optical fiber discrimination marker. Fig. 15 is a diagram explaining an example of application of a fault location identification system according to an embodiment of the present invention to an optical network with a multi-loop configuration. Fig. 16 is a diagram showing an example of an optical network configuration with a multi-loop configuration and issues that arise when identifying a fault location.

[0023] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings are schematic or conceptual, and the relationship between the thickness and width of each part, the size ratio between parts, etc., are not necessarily the same as those in reality. Furthermore, even when the same part is shown, the dimensions and ratios may be different depending on the drawing. In this specification and each drawing, elements similar to those previously described with reference to the previous drawings are designated by the same reference numerals, and detailed and redundant explanations will be omitted as appropriate.

[0024] [Configuration of Fault Location Locating System] FIG. 1 is a conceptual diagram showing an example of application of a fault location locating system to an optical network, to which a fault location locating method according to an embodiment of the present invention is applied.

[0025] FIG. 2 is a conceptual diagram showing an example of the configuration of a failure point identification system according to an embodiment of the present invention.

[0026] The optical network 10 illustrated in Fig. 1 is a general example, and is composed of a large number of optical cores 12 ((#1) to (#n)) (n is an integer equal to or greater than 2) each connected to an intra-office device 20. The intra-office device 20 is also connected to a core network 30. The optical cores 12 can be realized by optical fibers.

[0027] In this example, the optical core line 12 (#1) is connected to the home appliance 40 (#1) used by the first user, the optical core line 12 (#2) is connected to the home appliance 40 (#2) used by the second user, the optical core line 12 (#3) is connected to the home appliance 40 (#3) used by the third user, and the optical core line 12 (#n) is not connected to any home appliance 40 and serves as a backup core line.

[0028] As shown in FIG. 2, the fault location system 100 comprises a pulse tester 110 and a number of optical fiber discrimination markers 120 .

[0029] The optical fiber identification markers 120 are connected to the optical fibers 12 ((#1) to (#n)) respectively.

[0030] FIG. 3 is a conceptual diagram showing an example of the internal structure of the optical core discrimination marker.

[0031] 3, the optical fiber discrimination marker 120 is configured by storing an optical fiber 124 wound with a curvature that does not affect the optical transmission function in a space 122 secured inside a substantially box-shaped housing 123. Note that both ends of the optical fiber 124 are fusion splice points A and B where they are connected to the optical fiber 12, and therefore protrude outside the housing 123.

[0032] The fault location system 100 applies optical pulses from a pulse tester 110 via the optical network 10 to each optical fiber 12 to which such an optical fiber discrimination marker 120 is connected.

[0033] Each optical core cable discrimination marker 120 is given a unique response characteristic to an optical pulse in advance. Therefore, each optical core cable discrimination marker 120 returns a unique response when an optical pulse is applied from the pulse tester 110. The unique response characteristic given to each optical core cable discrimination marker 120 will be explained using FIG. 4.

[0034] FIG. 4 is a diagram for explaining the inherent response characteristics given to the optical core discrimination marker.

[0035] 4A is a front view showing the optical fiber 124 of the optical fiber discrimination marker 120 in an extended state. The optical fiber 124 has four sections K1 to K4 defined along its length, each section being separated by an interval L (e.g., 1 m) corresponding to the resolution of the pulse tester 110. The optical fiber 124 is spliced ​​to the optical fiber 12 at fusion points A and B. The number of sections K is determined by the length of the optical fiber 124 and the resolution of the pulse tester 110, and is not limited to four.

[0036] Each of the sections K1 to K4 is assigned a response characteristic to the optical pulse. The response characteristic to the optical pulse can be, for example, either a response characteristic in which the optical pulse attenuates or a response characteristic in which the optical pulse does not attenuate.

[0037] A response characteristic in which the optical pulse is attenuated can be imparted by providing a fusion point, a connector, a bend, or the like in section K. On the other hand, a response characteristic in which the optical pulse is not attenuated can be achieved by providing nothing in section K.

[0038] In this way, by combining the response characteristics assigned to each section K1 to K4, for example, by linking the response characteristics assigned to each section K1 to K4 in the order of the sections, a unique response characteristic R for each optical core line discrimination marker 120 can be realized.

[0039] The response characteristic R thus realized must be distinguishable from ordinary optical fiber fusion splices, device connections, and fault repair locations.

[0040] FIG. 5 is a waveform showing an example of the response characteristic.

[0041] In order to make the response characteristic R distinguishable from ordinary optical fiber fusion splices, device connections, and fault repair locations, it is preferable to set the response characteristic R to one that attenuates multiple times over a very short distance, i.e., one that makes it possible to distinguish between attenuation and no attenuation over a very short distance, as shown in, for example, FIG. 5 .

[0042] Furthermore, the unique response characteristic R can also be used as an identifier for identifying the optical core discrimination marker 120. For this purpose, for example, the response characteristic assigned to each of the sections K1 to K4 can be expressed as a numerical value, and the expressed numerical value can be used as the identifier.

[0043] As an example, the response characteristic is expressed as a binary number by representing a response characteristic in which the optical pulse attenuates as "1" and a response characteristic in which the optical pulse does not attenuate as "0." Then, the bit string obtained by arranging these binary numbers in the order of section K is used as the identifier of the optical core line discrimination marker 120.

[0044] 4, the response characteristic "1" of section K1, the response characteristic "1" of section K2, the response characteristic "0" of section K3, and the response characteristic "1" of section K4 are arranged in the order of sections K1 to K4 to obtain a bit string "1101." This bit string "1101" is used as the identifier of the optical core discrimination marker 120.

[0045] In the example shown in Figure 4, the response characteristic "1" of section K1 may be used to confirm the start position, and the bit string "101" realized by concatenating the response characteristics of the other three sections K2 to K4 may be used as an identifier for the optical core line discrimination marker 120.

[0046] In this specification, the bit string used to identify the optical core discrimination marker 120 is also referred to as an “identifier section.” The number of digits in the identifier section can be increased or decreased as desired depending on the attenuation level of the optical pulse, as long as it does not affect communication, and is not limited to three digits.

[0047] If the value of the identifier section is displayed by printing or the like on the outer surface of the housing 123 of the optical core cable discrimination marker 120, maintenance personnel can more easily identify the optical core cable discrimination marker 120 at the site. However, since a decimal numerical value is considered to be easier to recognize than a binary bit string, it is preferable to convert the binary bit string into a decimal numerical value and display the converted value on the outer surface of the housing 123 of the optical core cable discrimination marker 120.

[0048] FIG. 6 is an example of an external view of an optical fiber discrimination marker on which a decimal identifier portion is displayed.

[0049] In the example shown in Fig. 6, the value of the identifier section is displayed as "5" on the outer surface of the housing 123 of the optical core discrimination marker 120. "5" is the value obtained by converting the binary bit string "101" shown in Fig. 4 into a decimal number.

[0050] Next, specific examples for assigning the response characteristic R will be described in detail using the following three implementation examples.

[0051] [Implementation Example of Adding Response Characteristics to Optical Core Discrimination Marker] (Implementation Example 1) In implementation example 1, the response characteristics R are added to the optical core discrimination marker 120 by utilizing fusion.

[0052] FIG. 7 is a diagram showing an example in which response characteristics are imparted to an optical fiber discrimination marker by fusion.

[0053] FIG. 8 is a diagram showing a state in which the optical fiber shown in FIG. 7(b) is housed in a housing.

[0054] FIG. 7A shows that the resolution of the pulse tester 110 is 1 m in this example.

[0055] Fig. 7(b) is a front view showing the extended state of the optical fiber 124 that constitutes the optical core fiber discrimination marker 120. Using the resolution shown in Fig. 7(a), the optical fiber 124 of the optical core fiber discrimination marker 120 has ten sections K1 to K10 defined along its length, each meter apart. The black circles in the figure indicate fusion points, and the optical fiber 124 is connected to the optical core fiber 12 at fusion points A and B. Fusion points C1 to C6 are not connected to the optical core fiber 12, but are intentionally added to the optical fiber 124 in order to achieve the unique response characteristic R of the optical core fiber discrimination marker 120.

[0056] FIG. 7C is a diagram showing an example of response characteristics for each of sections K1 to K10.

[0057] FIG. 7D is a diagram showing an example of the response characteristics of each of the sections K1 to K10 expressed in bits.

[0058] 8, such an optical fiber 124 is wound with a curvature that does not affect the optical transmission function and stored in a space 122 inside a housing 123. Note that fusion points A and B, which are both ends of the optical fiber 124, are exposed to the outside of the housing 123 and connected to the optical fiber 12.

[0059] The response characteristics of sections K2, K4, and K6 to K9, which include fusion points C1 to C6, are "attenuated" and are represented by a bit "1." On the other hand, the response characteristics of sections K3 and K5, which do not include fusion points C1 to C6, are "not attenuated" and are represented by a bit "0." Note that sections K1 and K10, which include fusion points A and B connected to the optical fiber 12, are not taken into consideration in the response characteristics.

[0060] In this case, the bit string obtained by arranging the bits in sections K2 to K9 is "10101111," which is expressed as "175" in decimal. This value is used as the identifier of the optical core discrimination marker 120.

[0061] FIG. 9 is an example of an external view of an optical fiber discrimination marker in which the identifier "175" is displayed on the outer surface of the housing.

[0062] As illustrated in Figure 9, by displaying an identifier expressed in decimal numbers on the outer surface of the housing 123, maintenance personnel can easily identify the optical fiber discrimination marker 120 during on-site work.

[0063] (Implementation Example 2) In implementation example 2, a connector is used to impart the response characteristic R to the optical fiber discrimination marker 120.

[0064] FIG. 10 is a diagram showing an example in which a connector is used to provide a response characteristic to an optical fiber discrimination marker.

[0065] FIG. 11 is a diagram showing a state in which the optical fiber shown in FIG. 10(b) is housed in a housing.

[0066] 10(a), (c), and (d) are the same as FIG. 7(a), (c), and (d), so only FIG. 10(b) will be described here.

[0067] Fig. 10(b) is a front view showing the extended state of the optical fiber 124 that constitutes the optical core fiber discrimination marker 120. Using the resolution shown in Fig. 10(a), the optical fiber 124 of the optical core fiber discrimination marker 120 has ten sections K1 to K10 defined along its length, each 1 m apart. The optical fiber 124 is connected to the optical core fiber 12 at fusion points A and B. The connectors D1 to D6 are not connected to the optical core fiber 12, but are intentionally provided to achieve the unique response characteristic R of the optical core fiber discrimination marker 120.

[0068] 11, such an optical fiber 124 is wound with a curvature that does not affect the optical transmission function and stored in a space 122 inside a housing 123. Note that fusion points A and B, which are both ends of the optical fiber 124, are outside the housing 123 and connected to the optical fiber 12.

[0069] The response characteristics of sections K2, K4, and K6 to K9, which have connectors D1 to D6, are "attenuated" and are represented by a bit "1." On the other hand, the response characteristics of sections K3 and K5, which do not have connectors D1 to D6, are "not attenuated" and are represented by a bit "0." Note that sections K1 and K10, which include fusion points A and B connected to the optical fiber 12, are not taken into consideration in the response characteristics.

[0070] In this case, too, the bit string obtained by arranging the bits in sections K2 to K9 is "10101111", as in the case of FIG. 7, which is "175" in decimal notation.

[0071] In this way, by using connectors, it is possible to impart unique response characteristics, just as in the case of using fused points.

[0072] (Implementation Example 3) In implementation example 3, a response characteristic is imparted to the optical core discrimination marker 120 by utilizing bending.

[0073] FIG. 12 is a diagram showing an example in which a response characteristic is given to an optical core discrimination marker by utilizing bending.

[0074] FIG. 13 is a diagram showing a state in which the optical fiber shown in FIG. 12(b) is housed in a housing.

[0075] 12(a), (c), and (d) are the same as FIG. 7(a), (c), and (d), so only FIG. 12(b) will be described here.

[0076] Fig. 12(b) is a front view showing the extended state of the optical fiber 124 that constitutes the optical core line discrimination marker 120. Using the resolution shown in Fig. 12(a), the optical fiber 124 of the optical core line discrimination marker 120 has ten sections K1 to K10 defined along its length, each 1 m apart. Black circles in the figure indicate fusion points, and the optical fiber 124 is connected to the optical core line 12 at fusion points A and B. Bends E1 to E6 are intentionally provided to achieve a unique response of the optical core line discrimination marker 120.

[0077] 13, such an optical fiber 124 is wound with a curvature that does not affect the optical transmission function and stored in a space 122 inside a housing 123. Note that fusion points A and B, which are both ends of the optical fiber 124, protrude outside the housing 123 and are connected to the optical fiber 12.

[0078] The response characteristics of sections K2, K4, and K6 to K9, which have bends E1 to E6, are "attenuated" and are represented by a bit "1." On the other hand, the response characteristics of sections K3 and K5, which do not have bends E1 to E6, are "not attenuated" and are represented by a bit "0." Note that sections K1 and K10, which include fusion points A and B connected to the optical fiber 12, are not taken into consideration in the response characteristics.

[0079] In this case, too, the bit string obtained by arranging the bits in sections K2 to K9 is "10101111", as in the case of FIG. 7, which is "175" in decimal notation.

[0080] In this way, by utilizing bending, it is possible to impart unique response characteristics, similar to the case where fusion points are utilized.

[0081] As described above, by setting the fusion point C, connector D, or bend E for the optical fiber 124 of the optical fiber discrimination marker 120 at intervals L of the resolution of the pulse tester 110, it is possible to give the optical fiber 124 a unique response characteristic.

[0082] [Fault Location Identification Method] Next, a method for identifying a fault location in the optical network 10 by the fault location identification system 100 according to this embodiment will be described.

[0083] When a fault location in the optical network 10 is identified by the fault location identification system 100 according to this embodiment, an optical pulse is applied to the optical network 10 from the pulse tester 110 .

[0084] In response to the application of this pulse, a response is obtained from each optical core cable 12 constituting the optical network 10. An optical core cable 12 without a fault will provide a response characteristic R of the optical core cable discrimination marker 120, as shown in Fig. 5 for example. However, a response from an optical core cable 12 with a fault will include a response F indicating the fault in addition to the response characteristic R specific to the optical core cable discrimination marker 120, as shown in Fig. 14 for example.

[0085] FIG. 14 shows an example of a waveform that includes a response F indicating a fault in addition to the response characteristic R specific to the optical fiber discrimination marker.

[0086] As described above, the response characteristic R of each optical core line discrimination marker 120 is unique to each optical core line discrimination marker 120, so that it is possible to identify which optical core line discrimination marker 120 is responding based on the response characteristic R.

[0087] Therefore, as illustrated in Figure 14, if the response from the optical core 12 includes a response F indicating a fault in addition to the response characteristic R, the optical core 12 containing the fault point can be identified based on the response characteristic R.

[0088] Such a fault location identification system 100 can be applied not only to identifying a fault location in an optical network 10 having a uniquely determined communication path as illustrated in Fig. 1, but also to identifying a fault location in a second or subsequent loop in an optical network 10A having a multi-loop configuration having multiple communication paths as illustrated in Fig. 15. An example of application of the fault location identification system 100 to an optical network having a multi-loop configuration will be described below.

[0089] [Application to an Optical Network with a Multi-Loop Configuration] FIG. 15 is a diagram illustrating an example of application of the fault point identification system according to the embodiment of the present invention to an optical network with a multi-loop configuration.

[0090] Here, an example of application to an optical network with a multi-loop configuration, particularly to a second-stage loop, will be described using Fig. 15. Note that in Fig. 15, the same components as in Fig. 1 are numbered the same as in Fig. 1 to avoid redundant explanation.

[0091] The optical network 10A having a multi-loop configuration illustrated in FIG. 15 includes a first-stage loop 14 formed by optical core lines 12 and a second-stage loop 15 formed by optical core lines 12 .

[0092] An intra-office device 20 and an off-site device 22 are provided along the loop 14. An off-site device 22 is provided along the loop 15. The off-site device 22 is connected to both the loop 14 and the loop 15, so that the first stage loop 14 and the second stage loop 15 are connected by the off-site device 22.

[0093] In order to identify the fault location, optical fiber identification markers 120 are connected to each optical fiber 12 in the loop 14 as well as to each optical fiber 12 in the loop 15 .

[0094] 15 shows an example in which optical core line discrimination markers 120 (#1) and 120 (#2) are connected to the optical core line 12 of the loop 15 in both directions of the loop 15 from the vicinity of the off-site equipment 22. In this case, the optical core line discrimination marker 120 (#1) is used to detect a fault by applying an optical pulse to the loop 15 in the clockwise direction (path 1) in the figure, and the optical core line discrimination marker 120 (#2) is used to detect a fault by applying an optical pulse to the loop 15 in the counterclockwise direction (path 2) in the figure.

[0095] In order to make the response characteristics different for each direction of the loop 15, the optical core line discrimination marker 120(#1) and the optical core line discrimination marker 120(#2) are preset to exhibit different response characteristics R1, R2, as shown in the insets 15(1) and 15(2) of Fig. 15. For example, the (b) response characteristic R1 of the (a) optical core line discrimination marker 120(#1) shown in Fig. 15(1) includes three attenuations, and the (b) response characteristic R2 of the (a) optical core line discrimination marker 120(#2) shown in Fig. 15(2) includes two attenuations.

[0096] When the fault location identification system 100 identifies a fault along path 1, an optical pulse is applied from an optical pulse tester 110 (#1) to the loop 14. The applied optical pulse is passed through the off-site device 22 and applied to the optical core cable discrimination marker 120 (#1) along path 1, and a response characteristic R1 as shown in Fig. 15(1) is output from the optical core cable discrimination marker 120 (#1). If a fault exists in the loop 14 of path 1, a response F indicating the fault is also output following the response characteristic R1, as shown in Fig. 14.

[0097] On the other hand, when locating a fault along path 2, the fault location system 100 applies an optical pulse from the pulse tester 110 (#2) to the loop 14. The applied optical pulse is passed through the off-site device 22 and applied to the optical core cable discrimination marker 120 (#2) along path 2, and the optical core cable discrimination marker 120 (#2) outputs a response characteristic R2 as shown in Fig. 15(2). If there is a fault in the loop 14 of path 2, a response F indicating the fault is also output following the response characteristic R2, as shown in Fig. 14.

[0098] In this way, even if a failure occurs in the second or subsequent loop of the multi-loop optical network 10A, the fault location identification system 100 can identify not only the optical fiber 12 where the failure has occurred, but also the route based on the output response characteristic R.

[0099] As described above, according to the embodiments of the present invention, it is possible to provide a fault location identification system 100, a fault location identification method, a program, and an optical core wire discrimination marker 120 that can uniquely identify a fault location even in an optical network with multiple communication paths, such as an optical network with a multi-loop configuration.

[0100] In short, this invention is not limited to the above-described embodiments, and in the implementation stage, the components can be modified and embodied without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in the above-described embodiments. For example, some components may be omitted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined.

[0101] 1 Route 2 Route 10 Optical network 10A Optical network with multi-loop configuration 12 Optical fiber 14 First loop 15 Second loop 20 In-station equipment 22 Outside equipment 30 Core network 40 In-house equipment 100 Fault location identification system 110 Pulse tester 120 Marker for identifying optical fiber 122 Space 123 Housing 124 Optical fiber 200 Pulse tester A Fusion point B Fusion point C Fusion point D Connector E Bending F Response indicating fault K Section L Interval R Response characteristic α Point β Point

Claims

1. An optical fiber identification marker that is connected to the optical fibers that make up an optical network and exhibits unique response characteristics when an optical pulse is applied.

2. An optical fiber discrimination marker as described in claim 1, comprising an optical fiber, wherein the unique response characteristic is realized by a combination of response characteristics to the optical pulses given to each section defined by dividing the optical fiber into sections of a length corresponding to the resolution of a pulse tester that generates the optical pulses along the length of the optical fiber.

3. An optical core discrimination marker according to claim 2, wherein the response characteristics to the optical pulse include a response characteristic in which the optical pulse attenuates and a response characteristic in which the optical pulse does not attenuate.

4. An optical fiber discrimination marker as described in claim 3, wherein the response characteristic of attenuating the optical pulse is imparted by providing any one of a fusion point, a connector, and a bend in the section.

5. An optical core wire discrimination marker as described in claim 3, wherein the unique response characteristic is expressed by a bit string in which numbers representing response characteristics in which the optical pulse attenuates and numbers representing response characteristics in which the optical pulse does not attenuate are arranged in section order.

6. A fault location identification method in which an optical core cable discrimination marker according to any one of claims 1 to 5 applies an optical pulse to the optical network to identify a fault location in the optical network to which each optical core cable is connected, and identifies an optical core cable that responds indicative of a fault in response to the application of the optical pulse based on the unique response characteristics of the optical core cable discrimination marker connected to that optical core cable.

7. A system for locating a fault location in an optical network made up of a plurality of optical core lines, comprising: an optical core line discrimination marker connected to each of the plurality of optical core lines and exhibiting a unique response characteristic when an optical pulse is applied; and a pulse tester that applies the optical pulse to the optical network and identifies an optical core line that responds indicating a fault based on the unique response characteristic from the optical core line discrimination marker connected to that optical core line.

8. A program that enables a processor to perform the following functions: apply an optical pulse to an optical network consisting of multiple optical core lines, each connected to an optical core line discrimination marker that exhibits a unique response characteristic when an optical pulse is applied; and identify an optical core line that responds indicating a fault when the optical pulse is applied to the optical network, based on the unique response characteristic from the optical core line discrimination marker connected to that optical core line.

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