KR20130101636A - System and method for monitoring optical line - Google Patents

Abstract

PURPOSE: An optical line monitoring system and a method thereof are provided to accurately detect a line, where a failure has occurred, among multiple lines having the same or a similar distance in an optical time domain reflectometer (OTDR) pulse pattern. CONSTITUTION: A pulse matching part (240) confirms the identification information of multiple optical terminals with similar distance information, where the difference of distance information is less than a threshold value, in a reference state information table. The pulse matching part matches the identification information of each optical terminal to an individual pulse shown in a reference OTDR pulse pattern in order to enable the short distance priority of individual pulses shown in the reference OTDR pulse pattern to coincide with the short distance priority of optical terminals in the reference state information table. The pulse matching part matches the confirmed identification information of the multiple optical terminals to a single individual pulse. [Reference numerals] (120) Network inspection device; (210) Light signal transceiver unit; (220) Table generation unit; (230) Standard pulse pattern generation unit; (240) Pulse matching unit; (250) Obstacle verification unit; (260) Obstacle notice unit

Description

System and method for monitoring optical line

TECHNICAL FIELD The present invention relates to a light beam monitoring technology, and more particularly, to a light beam monitoring system and method for detecting a failed line among a plurality of lines having the same or similar distance in an optical time domain reflectometer (OTDR) pulse pattern. .

Optical cable has low loss and high bandwidth compared to copper wire and is widely used in high speed communication networks. However, the optical cable has a problem that the reliability is somewhat weak due to the low mechanical properties compared to the copper wire. That is, the optical cable is easier to cut compared to the copper wire, and there is a problem in that communication is impossible when the optical cable is bent at a predetermined angle or more. Therefore, operators who have built an optical communication network quickly identify the point of failure in order to recover the optical path when a failure occurs in the optical cable, and inject manpower into the point of failure.

On the other hand, a technique for checking whether an optical path is disturbed through an optical meter has been disclosed. Specifically, the optical measuring device sends an OTDR (Optical Time Domain Reflectometer) pulse to a plurality of optical termination devices connected to the distribution device, and the plurality of OTDR pulses (ie, pulse patterns) that are sequentially reflected and returned from the plurality of optical termination devices. ), And analyze each track for abnormalities.

However, the OTDR pulse pattern in which the plurality of OTDR pulses appear is a form in which the pulses are sequentially displayed according to the distance order, and the pulses returned from the plurality of optical termination devices located at the same or similar distance with respect to the optical measuring device are one waveform. Combined, they appear in the OTDR pulse pattern. That is, a plurality of pulses returning from the optical paths having the same or similar length are combined into one pulse and the combined pulses appear in the OTDR pulse pattern.

When a plurality of pulses returned from the optical termination devices located at the same or similar distance are combined as one pulse, the optical path monitoring system may not distinguish each optical path for the overlapping pulses in the OTDR pulse pattern. In addition, the optical beam monitoring system has a problem of delaying the response of the failure due to failure to accurately identify the failed optical path when a failure occurs in a particular optical path among the plurality of optical paths via the overlapping pulses.

The present invention has been proposed to solve such a conventional problem, and an object thereof is to provide a light ray monitoring system and method for accurately detecting a faulty line among a plurality of lines having the same or similar distance in an OTDR pulse pattern.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

According to the first aspect of the present invention for achieving the above object, the optical path monitoring system, the identification information of the optical termination device, the distance to the optical termination device and the reference state information to which the intensity of the optical signal received from the optical termination device is mapped. A database that stores a table and stores a reference Optical Time Domain Reflectometer (OTDR) pulse pattern in which a plurality of individual pulses appear; And determining whether or not the number of individual pulses represented in the reference OTDR pulse pattern is identical to the number of optical termination devices recorded in the reference state information table. The identification information is checked in the reference status information table, and the identification information of each optical termination device and the reference are matched so that the short-range ranking of the individual pulses appearing in the reference OTDR pulse pattern and the short-term order of the optical termination device in the reference status information table match. Matching individual pulses appearing in the OTDR pulse pattern, a pulse matching unit for matching the identified plurality of optical termination device identification information to one individual pulse; characterized in that it comprises a.

In accordance with a second aspect of the present invention for achieving the above object, a method for monitoring the quality of a light path in a light beam monitoring system includes: sending a status request optical signal to a plurality of optical termination devices, and responding a status response from each optical termination device. A receiving step of receiving an optical signal; A table storing step of analyzing the received state-responsive optical signal, mapping a distance for each optical termination device, a state-responsive optical signal strength, and identification information of the optical termination device, and storing the mapped information as a reference state information table; Pulses that send OTDR (Optical Time Domain Reflectometer) pulses to each optical termination device operating in a normal state, receive a plurality of OTDR individual pulses that are reflected and return, and store a reference OTDR pulse pattern in which the plurality of OTDR individual pulses appear. A pattern storing step; A discriminating step of determining whether the number of individual pulses indicated in the reference OTDR pulse pattern and the number of optical termination devices recorded in the reference state information table match; Confirming, in the reference state information table, a plurality of optical termination device identification information whose difference in distance information is equal to or less than a threshold value when the judgment result is inconsistent; And identifying the distance of each individual pulse in the reference OTDR pulse pattern, and identifying identification information of each optical termination device so that the near rank of the individual pulse and the optical termination device near rank in the reference state information table coincide with each other. Matching individual pulses appearing in the pulse pattern, matching step of matching the identified plurality of optical-end device identification information to one individual pulse; characterized in that it comprises a.

The present invention accurately grasps the path through the abnormal pulse, and recognizes the path found as a failure path and reports it to the manager, thereby reducing the recovery time of the optical path as well as improving work efficiency.

In particular, the present invention has an advantage of closely verifying whether there is a failure for each path by performing an additional failure check on an optical path having the same or similar distance that is not detected by comparing OTDR pulse patterns.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate exemplary embodiments of the invention and, together with the description, serve to explain the principles of the invention. And shall not be construed as limited to such matters.
1 is a view showing the configuration of a light path monitoring system according to an embodiment of the present invention.
2 is a view showing the configuration of a line inspection apparatus according to an embodiment of the present invention.
3 is a flowchart illustrating a method of matching a reference OTDR pulse pattern with identification information of an optical termination device in a light beam monitoring system according to an exemplary embodiment of the present invention.
4 is a diagram illustrating a reference OTDR pulse pattern according to an embodiment of the present invention.
FIG. 5 is a flowchart illustrating a method of verifying a failure of an optical path in the optical path monitoring system according to an embodiment of the present invention.
6 is a diagram illustrating an OTDR pulse pattern collected by a line inspection apparatus according to an embodiment of the present invention.

The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, in which: There will be. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing the configuration of a light path monitoring system according to an embodiment of the present invention.

As shown in FIG. 1, the optical path monitoring system according to the present invention includes an optical line device 110, a line inspection device 120, a database 130, a distribution device 140, and an optical termination device 141, 142. 143, 144).

Although the optical line device 110 is shown as one in FIG. 1, it is evident that a plurality of optical line devices, another distribution device and an optical termination device connected to the optical line device may be included in the optical path monitoring system.

The optical termination devices 141, 142, 143, and 144 are optical network units (ONUs), optical network terminals (ONTs), and the like, and form a subscriber network of a predetermined size to provide an optical communication service interface to end users. The optical termination devices 141, 142, 143, and 144 may accommodate fiber to the curb (FTTC), fiber to the building (FTTB), fiber to the floor (FTTF), and fiber to the office (FTTO). It is implemented to be connected to a number of end user terminals (eg, general purpose computer, telephone, etc.). In this case, the optical termination devices 141, 142, 143, and 144 may be connected to an end user terminal (eg, a computer) by an electric cable. In this case, the optical signal received from the optical line device 110 is converted into an electric signal. And transmits the electrical signal received from the user's terminal to an optical signal and transmits the electrical signal to the optical line apparatus 110 via the distribution device 140. The optical termination devices 141, 142, 143, and 144 are mainly installed in subscriber dense areas.

The distribution device 140 performs a function of branching the optical line device 110 and the single optical path L1 into a plurality of lines L1-1, L1-2, L1-3, and L1-4. That is, the distribution device 140 distributes the optical signal received from the optical line device 110 to the receiver end. In addition, the distribution device 140 combines the optical signals received from each optical termination device 141, 142, 143, 144 and transmits them to the optical line device 110.

In order to form more optical lines, a plurality of distribution devices 140 may be provided. That is, a primary distribution device may be installed in the optical communication network to be connected to the optical line device 140 to distribute the optical line primarily, and the primary distribution device and the optical termination device 141, 142, 143, and 144. The secondary distribution device which is installed between the second and second to distribute the optical line may be installed in the optical communication network.

An optical line terminal (OLT) 110 performs a function of connecting a backbone network and a subscriber network located in a specific region to each other. The optical line device 110 is connected to the distribution device 140 by a single optical path L1. In addition, the optical line device 110 performs one-to-many communication (point-to-multipoint communication) with the plurality of optical termination devices 141, 142, 143, and 144 through the distribution device 140.

The database 130 stores a reference state information table to which identification information, distance information, and optical signal strength information of the optical termination devices 141, 142, 143, and 144 are mapped. In this case, when there are a plurality of optical line devices 110, the database 130 stores the reference state information table for each optical line device 110. That is, the database 130, when there are a plurality of optical line devices 110, the optical terminal device ID to communicate with the optical line device 110, the distance to the optical terminal device (141, 142, 143, 144) The reference state information table to which the information and the respective optical signal intensity information are mapped are stored separately for each optical line device 110. In addition, the database 130 may store a reference optical time domain reflectometer (OTDR) pulse pattern and may also store failure history information for each optical termination device 141, 142, 143, or 144. The reference OTDR pulse pattern means a normal quality OTDR pulse pattern obtained when the optical path and the optical termination devices 141, 142, 143, and 144 are normal.

The line inspection device 120 is connected to a single light line L1 extending from the optical line device 110 and performs a function of analyzing whether a failure occurs in each light line. The line inspection device 120 may be connected to the single light path L1 through an optical switch device (not shown). In addition, the line inspection device 120 transmits the state request light signal to each of the optical end devices 141, 142, 143, and 144, which normally operate, and analyzes the received state response light signal. Check the distance from the signals 141, 142, 143 and 144 and the intensity of the state response optical signal. In addition, the optical line device 110 maps the distance and the optical signal intensity with the identified optical termination device (141, 142, 143, 144) and the identification information of the optical termination device (141, 142, 143, 144) This mapped information is stored in the database 130 as a reference state information table.

In addition, the line inspection device 120 extracts the reference OTDR pulse pattern from the database 130, and the optical termination devices 141, 142, 143, and 144 of the distance and the individual information table for each pulse shown in the reference OTDR pulse pattern. Based on the distance information, the identification information of the optical termination devices 141, 142, 143, and 144 is matched with each individual pulse.

Meanwhile, when the inspection point arrives, the line inspection device 120 transmits an OTDR-based pulse to the optical path, and reflects from the optical termination devices 141, 142, 143, and 144 and sequentially returns the OTDR pulse pattern and database ( The reference OTDR pulse patterns stored at 130 are compared to verify whether a failure occurs in the entire optical path. In this case, the line inspection device 120 refers to the reference OTDR pulse pattern matched with the optical terminal device identification information, and the branch light paths L1-1, L1-2, L1-3, and L1-4 in which the failed OTDR pulses are displayed. ) And the optical termination devices 141, 142, 143, and 144 included in the split optical path.

In addition, the line inspection device 120 transmits the status information optical signal to each of the optical termination devices 141, 142, 143, and 144, analyzes the received response signal, and then analyzes the received optical termination device ( By comparing the optical signal strength and distance for each of the 141, 142, 143, and 144 with the data of the reference state information table of the database 130, the specific branched beams L1-1, L1-2, L1-3, L1-4 ), Verify that the failure occurred.

The optical line device 110, the line inspection device 120 and the database 130 is mainly installed in the communication service provider management station.

2 is a view showing the configuration of a line inspection apparatus according to an embodiment of the present invention.

As shown in FIG. 2, the apparatus for checking a line according to an embodiment of the present invention includes an optical signal transceiver 210, a table generator 220, a reference pulse pattern generator 230, and a pulse matcher. 240, a failure verifying unit 250, and a failure reporting unit 260.

The optical signal transceiver 210 is connected to a single optical line L1 extending from the optical line apparatus 110 and is optically transmitted to the optical termination devices 141, 142, 143, and 144 through the single optical line L1. A signal is sent, and an optical signal transmitted from the optical termination devices 141, 142, 143, and 144 is received. The optical signal transceiver 210 may be connected to the single light path L1 through an optical switch device (not shown).

The table generator 220 generates a reference state information table (see Table 1) and stores the reference state information table in the database 130. Specifically, the table generating unit 220 is a state in which both the optical termination device (141, 142, 143, 144) and the optical path (L1, L1-1, L1-2, L1-3, L1-4) is operating normally In this case, the optical signal transmission and reception unit 210 is used to transmit the status request optical signal to each optical termination device (141, 142, 143, 144), and thus the status response optical signal is transmitted to each optical termination device (141, 142). 143, 144). In addition, the table generator 220 decodes and analyzes the received state response optical signal to measure distances from the optical termination devices 141, 142, 143, and 144, and intensity of each state response optical signal. The identification information, the optical signal strength, and the distance information of the terminal devices 141, 142, 143, and 144 are mapped, and the mapped data is stored in the database 130 as a reference state information table.

The reference pulse pattern generator 230 transmits an optical signal using the optical signal transceiver 210 to generate a reference OTDR pulse pattern based on the optical signals received from the optical termination devices 141, 142, 143, and 144. Perform the function. That is, the reference pulse pattern generator 230 operates the optical termination devices 141, 142, 143, and 144 and the optical paths L1, L1-1, L1-2, L1-3, and L1-4 normally. In the state, the OTDR pulses are transmitted to the optical termination devices 141, 142, 143, and 144 using the optical signal transceiver 210 to receive a plurality of OTDR individual pulses that are reflected and returned. Besides. The reference pulse pattern generator 230 sets the pattern in which the plurality of received OTDR individual pulses appear as a reference OTDR pulse pattern (see FIG. 4) and stores the pattern in the database 130.

The pulse matching unit 240 based on the distance information of the reference OTDR pulse pattern of the database 130 and the distance information of the reference state information table, the individual pulses and the optical termination devices 141, 142, 143, and 144 that appear in the OTDR pulse pattern ) To perform the matching function. Specifically, the pulse matching unit 240 checks the distance information of each optical termination device 141, 142, 143, 144 in the reference state information table (see Table 1) of the database 130, and the reference OTDR pulse pattern The identification information of each of the optical termination devices 141, 142, 143, and 144 and the individual information of the optical termination devices 141, 142, 143, and 144 correspond to the short distance rankings of the optical termination devices 141, 142, 143, and 144, respectively. The pulses are matched and stored in the database 130. In this case, when the number of the optical termination devices 141, 142, 143, and 144 does not match the number of individual pulses shown in the OTDR pulse pattern, the pulse matching unit 240 determines that the plurality of pulses are overlapped as one and the same distance. The plurality of optical termination devices 141, 142, 143, and 144 having information or having a difference in distance information less than or equal to a threshold value (for example, 20 m) from the reference state information table, and the plurality of optical termination devices 141, 142, The identification information of 143 and 144 is matched to one individual pulse.

When the inspection point arrives, the failure verification unit 250 verifies whether the optical paths L1, L1-1, L1-2, L1-3, and L1-4 are damaged by using the optical signal transceiver 210. It performs the function. Specifically, the failure verification unit 250 transmits an OTDR pulse to each optical path using the optical signal transceiver 210, collects the OTDR pulse pattern, and then references the collected OTDR pulse pattern and the database 130. The OTDR pulse patterns are compared to verify the failure of each optical path L1, L1-1, L1-2, L1-3, L1-4, and identify the failed optical path. At this time, the failure verifying unit 250, if it is impossible to identify the failure zone through the comparison of the reference OTDR pulse pattern and the collected OTDR pulse pattern, a plurality of optical termination devices 141, 142, 143, having the same distance or similar distance 144 is identified in the database 130, and the status request optical signal is transmitted to each of the plurality of optical termination devices 141, 142, 143, and 144 using the optical signal transceiver 210, and thus received By analyzing the status response optical signal, the failed optical paths L1, L1-1, L1-2, L1-3 and L1-4 are identified.

In addition, when the collected OTDR pulse pattern and the reference OTDR pulse pattern coincide with each other by more than a threshold value (for example, 95%), the failure verifying unit 250 may have the same or similar distance information (L1-1). , L1-2, L1-3, L1-4) in order to more accurately verify the status request optical signal to each of the plurality of optical termination devices 141, 142, 143, 144 having the same or similar distance By transmitting and analyzing the received state response optical signal, it is verified whether or not each branch light path (L1-1, L1-2, L1-3, L1-4) is disturbed.

When the failure notification unit 260 detects a failure of a specific optical path by the failure verification unit 250, the failure notification unit 260 checks the identification information of the optical termination devices 141, 142, 143, and 144 included in the optical path, and the optical termination device. After generating the failure occurrence information in which the identification information of (141, 142, 143, 144) is recorded, the failure occurrence information is notified to the administrator using the administrator's e-mail or mobile phone number previously stored.

3 to 6 will be described in more detail a method for monitoring the state of the optical path in the optical path monitoring system according to the present invention.

3 is a flowchart illustrating a method of matching a reference OTDR pulse pattern with identification information of an optical termination device in a light beam monitoring system according to an exemplary embodiment of the present invention.

Referring to FIG. 3, the table generator 220 of the line inspection apparatus 120 includes the optical termination devices 141, 142, 143, and 144 and the optical paths L1, L1-1, L1-2, L1-3, In a state in which all of L1-4) normally operate, the optical signal transmitting / receiving unit 210 is used to transmit the state request optical signal to the optical termination device 1 (141). Then, the optical termination device 1 141 transmits a state response optical signal in which its identification information is recorded, and the table generator 220 receives the state response optical signal through the optical signal transmission / reception unit 210 ( S301).

Subsequently, the table generating unit 220 confirms the round trip delay time from the time point at which the state request light signal is transmitted to the time point at which the state response light signal is received, and decodes the state response light signal to record the state response light signal. Check the identification information of the optical termination device 1 (141). Next, the table generator 220 measures the distance from the optical termination device 1 (141) by using Equation 1 below (S303).

D: Distance between optical line device and terminator

n: refractive index

dt: sum of delays for each device

t: Round trip delay time

C: speed of light

Here, 'dt' is a state in the time delay and the optical termination device 141, 142, 143, 144 internally delayed in order to relay the optical signal (that is, the state request optical signal and the state response optical signal) in the distribution device 140 As the sum of the delay time required to transmit the response optical signal, the line check device 120 determines the processing delay time of the distribution device 140 and the optical termination devices 141, 142, 143, and 144 from the manager in advance. Can receive and save input.

The table generator 110 measuring the distance from the optical termination device 1 (141) measures the intensity of the state response optical signal received from the optical termination device 1 (141). Subsequently, the table generation unit 220 maps the identification information of the optical termination device 1 141, the intensity of the state response optical signal, and the distance measured in step S303, and uses the mapped information as a reference state information table. 130) (S305). Subsequently, the table generator 220 checks whether the state measurement of all the optical termination devices 141, 142, 143, and 144 that can communicate is completed, and if not, proceeds to step S301 to resume the remaining optical termination devices 2,. 3,4 (142, 143, 144) and the distance and the intensity of the status response optical signal received from the optical termination device (142, 143, 144) is measured, respectively, identification of the optical termination device (142, 143, 144) Information, the distance from the optical termination devices 142, 143 and 144 and the intensity of the status response optical signal received from the optical termination devices 142, 143 and 144 are recorded in the reference status information table of the database 130 ( S307).

Meanwhile, the table generator 220 transmits a state request optical signal to each of the optical termination devices 141, 142, 143, and 144 at once, and sequentially receives them from the optical termination devices 141, 142, 143, and 144, respectively. The plurality of state response optical signals may be analyzed to measure distances and optical signal intensities of the respective optical termination devices 141, 142, 143, and 144. That is, the table generator 220 broadcasts or multicasts the state request optical signal, and analyzes the plurality of state request optical signals thus received, thereby providing a distance from each of the optical termination devices 141, 142, 143, and 144. And measurement of the optical signal strength may be performed.

Table 1 below shows a reference state information table according to an embodiment of the present invention.

Fiber Termination Unit ID Optical signal strength (dBm) Street ONT1 -28 15.5 km ONT2 -27 13 km ONT3 -27.5 13 km ONT4 -28.5 17 km

As shown in Table 1, when checking the status information of each optical termination device (141, 142, 143, 144 connected to the optical line device 110), the database 130 is the optical termination device (141, 142, 143) And a reference state information table in which the identification information of 144, the optical signal strength, and the distance to the optical termination devices 141, 142, 143, and 144 are mapped.

Next, the reference pulse pattern generator 230 operates all of the optical termination devices 141, 142, 143, and 144 and the optical paths L1, L1-1, L1-2, L1-3, and L1-4. In this state, the OTDR pulses are sent to each of the optical termination devices 141, 142, 143, and 144 using the optical signal transceiver 210 to receive a plurality of OTDR individual pulses reflected and returned. Subsequently, the reference pulse pattern generator 230 sets a reference OTDR pulse pattern (see FIG. 4) and stores the pattern represented by the plurality of OTDR individual pulses in the database 130 (S309).

Then, the pulse matching unit 240 checks the distance information of each optical termination device 141, 142, 143, 144 in the reference state information table (see Table 1) of the database 130, and uses the distance information. The route via each individual pulse shown in the reference OTDR pulse pattern is identified (S311). In detail, the pulse matching unit 240 checks the near rank of the optical termination devices 141, 142, 143, and 144 based on the distance information recorded in the reference state information table. For example, when the pulse matching unit 240 extracts the distance information as shown in Table 1 from the database 130, the short-range order has the optical termination device 2 (142), the optical termination device 3 (143), and the optical termination device 1 (141). It is confirmed that the optical termination device 4 (144). At this time, the line inspection device 120 recognizes that the distance between the optical termination device 2 142 and the optical termination device 3 143 is the same.

Subsequently, the pulse matching unit 240 checks the distance information for each pulse in the reference OTDR pulse pattern, and the short distance ranks of the individual pulses and the short distance ranks of the optical termination devices 141 correspond to each other. The identification information of each of the optical termination devices 141, 142, 143, and 144 and each individual pulse are matched and stored in the database 130 (S213).

In this case, when the number of the optical termination devices 141, 142, 143, and 144 does not match the number of individual pulses shown in the OTDR pulse pattern, the pulse matching unit 240 determines that the plurality of individual pulses are overlapped as one. In addition, the pulse matching unit 240 checks a plurality of optical termination device identification information having the same distance information or similar distance information having a difference in distance information equal to or less than a threshold value (for example, 20 m) from a reference state information table. Match the optical termination device identification to one individual pulse.

4 is a diagram illustrating a reference OTDR pulse pattern according to an embodiment of the present invention.

Referring to FIG. 4, in the reference OTDR pulse pattern, the Y axis represents the intensity of the pulse and the X axis represents the distance. That is, in the reference OTDR pulse pattern, the pulse intensity increases from bottom to top with respect to the Y axis, and the distance from the left to right with respect to the X axis increases. In the reference OTDR pulse pattern of FIG. 4, pulse positions having close distance information are in the order of reference numerals 410, 420, and 430 pulses. That is, in the reference OTDR pulse pattern, the reference numeral 410 has the closest distance information, and the reference 430 pulse has the farthest distance information.

When the reference state information table as shown in Table 1 is stored in the database 130, the pulse matching unit 240 is represented by the number of optical termination devices (141, 142, 143, 144) and the OTDR pulse pattern. It is confirmed that the number of individual pulses (that is, three) does not coincide, and thus, it is determined that two OTDR pulses are superimposed as one. In addition, the pulse matching unit 240 may include the optical termination device 2 142 and the optical termination device 3 143 having the same distance information or having similar distance information having a distance difference equal to or less than a threshold (for example, 20 m). Check it in the standard status information table in Table 1.

Next, the pulse matching unit 240 matches the pulse of reference numeral 420 shown in the reference OTDR pulse pattern of FIG. 4 with the identification information ONT1 of the optical termination device 1 141 having the third closest distance information. The pulse 430 is matched with the identification information of the optical termination device 4 (ONT4) having the farthest distance information. In addition, the pulse matching unit 240 matches the identification information of the optical termination device 2 (142) and the identification information of the optical termination device 3 (143) having the same distance information and the first order of the shortest distance with the pulse of reference numeral 410. That is, the pulse matching unit 240 overlaps and matches identification information of the optical termination devices 2 and 3 142 and 143 having the same distance information with one OTDR pulse 410. When the matching is completed, the pulse matching unit 240 stores the reference OTDR pulse pattern matched with the identification information of the optical termination devices 141, 142, 143, and 144 in the database 130.

By using the stored reference OTDR pulse pattern through this method, it is possible to identify the route paths L1-1, L1-2, L1-3, L1-4 of each pulse shown in the OTDR pulse pattern.

FIG. 5 is a flowchart illustrating a method of verifying a failure of an optical path in the optical path monitoring system according to an embodiment of the present invention.

6 is a diagram illustrating an OTDR pulse pattern collected by a line inspection apparatus according to an embodiment of the present invention.

5 and 6, the failure verifying unit 250 of the line inspection apparatus 120 checks whether a light ray inspection point arrives, and when the inspection point arrives, the optical signal transceiver 210 is used. By sending OTDR pulses to the respective optical termination devices 141, 142, 143, and 144, and sequentially receiving a plurality of OTDR individual pulses reflected from each optical termination device 141, 142, 143, and 144, the optical signal is returned. The OTDR pulse patterns of the optical paths connected to the line device 110 are collected (S501 and S503).

Subsequently, the failure verification unit 250 extracts, from the database 130, the reference OTDR pulse pattern matching the identification information of each optical termination device 141, 142, 143, and 144, and collects the reference OTDR pulse pattern and the collected information. The OTDR pulse patterns are compared to check the coincidence of the two pulse patterns (S505).

Next, when the matching result is not more than a threshold (eg, 95%) as a result of the comparison, the failure verification unit 250 determines whether or not a failure section can be identified by comparing the reference OTDR pulse pattern with the collected OTDR pulse pattern. (S507, S509). At this time, the failure verifying unit 250 identifies whether a failure of the optical path section by checking whether the individual pulse that does not match the intensity of each individual pulse appearing in the reference OTDR pulse pattern appears in the collected OTDR pulse pattern.

For example, referring to FIGS. 4 and 6, when the OTDR pulse pattern of FIG. 6A is collected, the failure verification unit 250 collects the reference OTDR pulse pattern of FIG. 4 and the OTDR collected at the time of inspection. By comparing the coincidence ratio of (a) of FIG. 6, which is a pulse pattern, it is possible to identify that individual non-matching pulses are 612 pulses, and identify that the optical termination device identification information matched with the 612 pulses is the optical termination device 1 (ONT1).

On the other hand, when the OTDR pulse pattern of FIG. 6 (b) is collected, the failure verification unit 250 has a matching ratio between FIG. 4, which is a reference OTDR pulse pattern, and FIG. You can see that it is below the threshold. However, the failure verifying unit 250 may determine that the individual pulses ie, 622, 623, and 624 corresponding to the individual pulses 410, 420, and 430 of the reference OTDR pulse pattern (FIG. 4) are replaced by the OTDR pulse pattern (FIG. b)), but in the collected OTDR pulse pattern (FIG. 6 (b)), a new pulse 621 is generated by any branching path L1-1, L1-2, L1-3, L1-. 4) it does not identify whether it was introduced through One of the reasons for generating the new pulse 621 may be due to the occurrence of a breaking fault in the sections L1-2 and L1-3 having the same or similar distance, thereby causing the Fresnel reflection.

If it is possible to identify a fault section by comparing the reference OTDR pulse pattern with the collected OTDR pulse pattern, the error verifying unit 250 may be inconsistent with the reference OTDR pulse pattern among individual pulses shown in the collected OTDR pulse pattern. Check the individual pulses. Subsequently, the failure verifying unit 250 checks the identification information of the optical termination devices 141, 142, 143, and 144 that match the individual discrepancies in the reference OTDR pulse pattern having matching information (S511).

Then, the failure notification unit 260 recognizes that a failure has occurred in the optical path including the checked optical termination device (141, 142, 143, 144), and informs the administrator of this failure occurrence information (S513). In this case, the failure notification unit 260 checks the identification information of the optical termination devices 141, 142, 143, and 144 included in the failed optical path in the reference OTDR pulse pattern having matching information, and checks the identified optical termination device ( After generating the failure occurrence information in which the identification information of 141, 142, 143, and 144 is recorded, the failure occurrence information is notified to the administrator using an administrator's e-mail or mobile phone number previously stored.

For example, referring to FIG. 6A, the failure verification unit 250 compares the OTDR pulse pattern of FIG. 6A and the reference OTDR pulse pattern of FIG. 4 collected at the time of inspection, and FIG. In the OTDR pulse pattern according to 6 (a), the individual pulses of 611 and 613 coincide with the individual pulses of 410 and 430, respectively, but the individual pulses of reference 612 do not match the individual pulses of reference 420. Check. Then, the failure verifying unit 250 checks the optical terminal device identification information matching the individual pulses of the 612 in the reference OTDR pulse pattern having matching information in order to identify the path in which the individual pulses of the 612 are introduced. That is, the failure verifying unit 250 verifies that the failure occurs in the optical path path (that is, L1-1) including the optical termination device 1 141 reflecting the individual pulses of 612. Then, the failure notification unit 260 generates the failure occurrence information in which the identification information ONT1 of the optical termination device 1 141 is recorded and notifies the manager. Accordingly, the administrator determines that a failure occurs in the path including the optical termination device 1 (141), and checks the corresponding path first to perform a failure recovery.

On the other hand, in operation S509, the failure verifying unit 250 compares the reference OTDR pulse pattern with the collected OTDR pulse pattern, and if it is impossible to identify a failure section, the plurality of optical termination device identification information duplicated and matched to individual pulses may be obtained. Check in the reference OTDR pulse pattern with matching information. Subsequently, the failure verifying unit 250 transmits a state request optical signal to each of the identified plurality of optical termination devices 142 and 143 using the optical signal transceiver 210, and transmits the plurality of optical termination devices ( 142 and 143 respectively receive a status response optical signal (S515). Subsequently, the failure verification unit 250 analyzes the state response optical signal, and measures the distance from the optical termination devices 142 and 143 having the same or similar distance and the intensity of the state response optical signal, respectively. In this case, the failure verification unit 250 may calculate the distance from the optical termination devices 142 and 143 through Equation 1 described above.

Next, the failure verifying unit 250 compares the measured distance and the optical signal strength with the information of the reference state information table, so that the measured distance or the optical signal intensity is equal to the information of the reference state information table and the reference value (for example, 30 m and the signal strength is 2dBm or more is checked whether the optical termination device (142, 143) (S517). At this time, the failure verification unit 250 checks the identification information of the optical termination device (142, 143) measuring the distance and the signal strength, and the distance information and the optical signal strength information mapped with the identification information in the reference state information table After extraction, the measured distance and optical signal strength are compared with the extracted distance information and signal strength information, respectively.

Subsequently, when any one of the measured distance and the optical signal strength deviates from the reference state information table and the reference value or more, the failure verification unit 250 transmits the optical signal of the optical termination devices 142 and 143 that have sent out the optical signal. The identification information is checked, and it is determined that the failure occurs in the optical paths L1-2 and L1-3 including the optical termination devices 142 and 143 (S519). In this case, when the measured distance is different from the distance information of the reference state table and the reference value (for example, 30 m) or more, the failure verifying unit 250 generates a failure such as disconnection or break in the corresponding optical paths L2 and L3. It can be judged that. In addition, the failure verifying unit 250 blends in the optical paths L2 and L3 when the measured optical signal strength is different from the optical signal strength information of the reference state table by more than a reference value (for example, 2 dBm). It can be determined that the optical signal loss caused by

Then, the failure notification unit 260 recognizes that a failure has occurred in the optical paths L2 and L3 including the identified optical termination devices 142 and 143, and notifies the manager of the failure occurrence information (S513).

On the other hand, in step S507, the failure verification unit 250, if the collected OTDR pulse pattern and the reference OTDR pulse pattern is matched with each other more than the threshold value (for example, 95%), the optical termination device having the same or similar distance information ( In order to more accurately verify whether or not the 142, 143) of the failure, the steps S515 and S517 proceeds. That is, even if the collected OTDR pulse pattern and the reference OTDR pulse pattern coincide with each other by more than a threshold value (for example, 95%), the failure verification unit 250 matches the plurality of optical termination device identification information that overlaps and matches individual pulses. The reference OTDR pulse pattern having the information is checked, and a status request optical signal is sent to each of the plurality of optical termination devices 142 and 143 corresponding to the identified identification information.

Next, the failure verification unit 250 analyzes the state response optical signals received from the plurality of optical termination devices 142 and 143, and the distance from the optical termination devices 142 and 143 and the optical termination devices 142. , And measure the intensity of the state response optical signal received from 143). In addition, the failure verifying unit 250 compares the measured distance and the optical signal strength with the information of the reference state information table, and the measured distance and the optical signal intensity correspond to the information and the reference value (for example, the distance is 30m in the reference state information table). , The signal strength is checked by the optical termination device (142, 143) whether the deviation is more than -2dBm). Subsequently, when any one of the measured distance and the optical signal strength deviates from the reference state information table or more than the reference value, the failure verifying unit 250 includes the optical path including the optical termination devices 142 and 143 ( L1-2, L1-3) is identified as a failure.

On the other hand, the failure verifying unit 250 determines that all the optical paths operate normally when both the measured distance and the optical signal strength do not deviate beyond the reference state information table and the reference value.

As described above, the present invention accurately identifies a path into which an abnormal pulse flows, and recognizes the path as a path for generating a failure and reports the result to an administrator, thereby shortening the recovery time of the optical path and improving work efficiency. In addition, the present invention closely examines whether there is a failure for each beam by performing an additional failure inspection on the same or similar distance optical paths that are not detected by comparing OTDR pulse patterns.

While the specification contains many features, such features should not be construed as limiting the scope of the invention or the scope of the claims. In addition, the features described in the individual embodiments herein may be combined and implemented in a single embodiment. Conversely, various features described in the singular < Desc / Clms Page number 5 > embodiments herein may be implemented in various embodiments individually or in combination as appropriate.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. The present invention is not limited to the drawings.

110: optical line device 120: line inspection device
130: database 140: distribution device
141, 142, 143 and 144: Optical termination device 210: Optical signal transceiver
220: table generator 230: reference pulse pattern generator
240: pulse matching unit 250: failure verification unit
260: disability notification unit

Claims (11)

A reference optical time domain reflectometer (OTDR) pulse pattern in which a plurality of individual pulses are stored and a reference state information table in which identification information of the optical termination device, a distance from the optical termination device, and an optical signal intensity received from the optical termination device are mapped. A database for storing the; And
If the number of individual pulses shown in the reference OTDR pulse pattern and the number of optical termination devices recorded in the reference state information table are different from each other, the plurality of optical termination devices having a difference in distance information is equal to or less than a threshold value are identified. Information is identified in the reference status information table, and identification information of each optical termination device and the reference OTDR are matched such that a short-range order of individual pulses appearing in the reference OTDR pulse pattern and a short-term order of the optical termination device in the reference state information table are identical. And a pulse matching unit for matching individual pulses appearing in the pulse pattern, and matching the identified plurality of optical termination device identification information to one individual pulse. The method of claim 1,
When the inspection point of the optical ray arrives, an OTDR pulse pattern is generated in which a plurality of OTDR individual pulses that are reflected and returned by sending an OTDR pulse to each optical termination device are obtained, and the obtained OTDR pulse pattern and a reference OTDR pulse of the database And a failure verifying unit verifying a pattern matching rate and verifying a failure of the optical path based on the matching rate. 3. The method of claim 2,
The failure verification unit,
By comparing the individual pulses appearing in the obtained OTDR pulse pattern and the individual pulses appearing in the reference OTDR pulse pattern, respectively, and checking the discrepancies of the individual pulses, and confirming the optical termination device identification information matched with the individual pulses, The optical line surveillance system, characterized in that for identifying the section of the furnace. 3. The method of claim 2,
The failure verification unit,
Identify a plurality of optical termination device identification information matched with the one individual pulse, send a status request optical signal to each optical termination device corresponding to the identification information, and receive a status response optical signal from the optical termination device, respectively; And analyzing the respective state response optical signals to measure the intensity of the state response optical signal and the distance between the optical termination devices for each of the plurality of optical termination devices. When the optical signal intensity or distance stored in the table and the deviation is greater than the reference value, the optical termination device that sent the separated optical signal is identified, and it is determined that the failure occurred in the optical path section including the optical termination device Ray Surveillance System. 5. The method of claim 4,
The failure verification unit,
By comparing the reference OTDR pulse pattern with the obtained OTDR pulse pattern, it is possible to determine whether or not it is possible to identify a faulty optical path, and if it is impossible to identify, identify the plurality of optical termination device identification information matched with the one individual pulse and identify the identification. And a status request optical signal to each optical termination device corresponding to the information. 6. The method according to any one of claims 3 to 5,
And a failure notification unit for identifying identification information of the optical termination device included in the failed optical path section, and generating and reporting failure occurrence information recorded with the identification information of the optical termination device to an administrator. Ray Surveillance System. The method of claim 1,
Receives a status request optical signal from each optical termination device by sending a status request optical signal to each optical termination device, and analyzes the received response signal to measure distance and intensity for each optical response device. And a table generator configured to map the measured distance between the optical termination device and the optical signal strength with identification information of the corresponding optical termination device, and store the mapped information in the database as a reference state information table. Ray monitoring system, characterized in that. As a method of monitoring the quality of a light beam in a fiber optic monitoring system,
A receiving step of transmitting a status request optical signal to a plurality of optical termination devices and receiving a status response optical signal from each optical termination device;
A table storing step of analyzing the received state-responsive optical signal, mapping a distance for each optical termination device, a state-responsive optical signal strength and identification information of the optical termination device, and storing the mapped information as a reference state information table;
Pulses that send OTDR (Optical Time Domain Reflectometer) pulses to each optical termination device operating in a normal state, receive a plurality of OTDR individual pulses that are reflected and return, and store a reference OTDR pulse pattern in which the plurality of OTDR individual pulses appear. A pattern storing step;
A discriminating step of determining whether the number of individual pulses indicated in the reference OTDR pulse pattern and the number of optical termination devices recorded in the reference state information table match;
Confirming, in the reference state information table, a plurality of optical termination device identification information whose difference in distance information is equal to or less than a threshold value when the judgment result is inconsistent; And
Identify the distance of each individual pulse in the reference OTDR pulse pattern, and identify identification information of each optical termination device so that the near-order ranking of the individual pulses and the optical-end device near-field ranking in the reference state information table correspond to the reference OTDR pulses. Matching individual pulses appearing in the pattern, the matching step of matching the identified plurality of optical-end device identification information to one individual pulse; comprising a. The method of claim 8,
After the matching step,
Receiving a plurality of OTDR pulses that are reflected and returned by sending OTDR pulses to the plurality of optical termination devices when the inspection point of the optical path arrives, and obtaining an OTDR pulse pattern in which the plurality of OTDR pulses appear; And
When there is an inconsistent individual pulse by comparing the individual pulses appearing in the obtained OTDR pulse pattern with the individual pulses appearing in the reference OTDR pulse pattern, the identification information of the optical termination device matched with the individual pulses is used as the reference OTDR pulse. Identifying a faulty optical path section by checking in a pattern. The method of claim 9,
After the matching step,
Identifying a plurality of optical termination device identification information matched with the one individual pulse, and transmitting a status request optical signal to each optical termination device corresponding to the identification information to receive a status response optical signal from each optical termination device. step;
Analyze each received state response optical signal and measure the intensity of the state response optical signal and the distance between the optical termination device for each of the plurality of optical termination devices, and store the measured distance and the optical signal intensity in the reference state table. Comparing the optical signal strength and distance; And
As a result of the comparison, if any one of the measured optical signal intensity and distance deviates from the optical signal intensity or distance stored in the reference state table or more than a reference value, the optical termination device that transmits the separated optical signal is identified, and the optical And determining that a failure has occurred in the optical path including the terminating device. 11. The method according to claim 9 or 10,
Checking identification information of the optical termination device included in the failed optical path section, and generating and reporting the failure occurrence information recorded with the identification information of the optical termination device to an administrator; Surveillance method.

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