KR102287778B1 - Optical fiber monitoring device and long-distance optical path monitoring system comprising linear or ring type multi-stage connected operating terminal using the same - Google Patents

Abstract

The present invention relates to an optical path monitoring device and system for monitoring a failure of an optical path, wherein the optical path monitoring device according to the present invention is connected to a remote terminal 30 constituting an optical network and measures OTDR external OTDR module (50) light monitoring circuits 37 and 51 for generating measurement light and detecting that the measurement light is reflected; Provided in the remote terminal 30 and the unidirectional filters 39 and 53 connected to the light monitoring circuits 37 and 51 and outputting the measurement light to the second optical fiber F2 connected to the external OTDR module 50 It is characterized in that it is composed of a third optical fiber (F3) connecting the bypass circuit (33) and the unidirectional filters (39, 53).

Description

Optical fiber monitoring device and linear, ring-type multi-stage connection operation terminal using the same Long-distance optical fiber monitoring system

The present invention relates to an optical path monitoring apparatus for monitoring a failure of an optical path and an optical network system using the same, and more particularly, to a multi-stage connection in which a plurality of remote terminals are linearly or ring-typed, or a linear or ring-type multistage connection with a long distance between remote terminals. It relates to an optical fiber monitoring device necessary for monitoring a connected optical network, and a linear, ring-type, multi-stage connection operation terminal long-distance optical path monitoring system that can be implemented using the same.

As the informatization accelerated, the demand for data transmission amount and speed also increased. Accordingly, a linear or ring-type multi-stage network that connects the backbone network and the subscriber network with optical communication instead of a wire with a small channel capacity or wireless communication with a problem of bandwidth division In most cases, it constitutes

Optical fibers are usually processed or buried underground, and they are combined with optical network devices such as laser diodes, optical multiplexers, OFD optical distribution boxes, and photoelectric converters to form an optical network.

Among the elements constituting the optical network, equipment such as an optical multiplexer is installed in a relatively safe environment such as in a separate management center, office building, and on-site enclosure, and an element management system (EMS) to efficiently manage the equipment is provided. It is easy to monitor and manage. On the other hand, most of the optical path is exposed to the outdoors, and there are many cases of underground burial that are buried underground, so it is affected by reclamation or repair works such as gas and water pipes. There is often a risk.

An optical path monitoring system has been introduced to monitor such an optical path, and an example of such a conventional optical path monitoring system is disclosed in 'Patent Document 1'. 1 is a conceptual diagram of a conventional optical path monitoring system, wherein the conventional optical path monitoring system comprises a fiber terminal 1, an optical splitter 2, an optical network unit 3, and an optical network constituting an existing optical network system. A WDM (Wavelength Division Multiplexing) coupler 5, a monitoring device 6 and a control unit 7 are added to the terminal 4, and the monitoring device 6 is optionally connected to the optical path to monitor the abnormality of the optical path.

For better understanding, first looking at the existing optical network system, the optical fiber terminal 1 is provided in a central base station such as a telephone office to transmit an optical signal to the optical splitter 2, and from the optical splitter 2 to the optical network unit ( 3) Alternatively, by sending the optical signal to the optical network terminal 4, the optical signal is transmitted to the end 8 of the optical network. Considering the transmission of the optical signal in the opposite direction, the optical signal transmitted from at least one optical network unit 3 or optical network terminal 4 to the optical splitter 2 is transmitted to the central base station through the optical fiber terminal 1 do. The optical fiber terminal 1 may include an optical multiplexer (not shown) in order to transmit signals of a plurality of wavelength bands together, and in this case, the optical splitter 2 is a multiplexed signal provided by the optical fiber terminal 1 . A demultiplexer (not shown) for splitting the optical signal for each wavelength and transmitting it to the optical network unit 3 or the optical network terminal 4 may be provided.

However, since this conventional optical path monitoring system has a structure in which the monitoring device 6 is connected to the central control unit 7 and monitors the optical path connected to the remote optical network unit 3, the optical splitter 2, the optical network It is impossible to ignore the loss that occurs in the process of connecting and transferring the optical fiber to the unit (3), etc., and as these losses accumulate, if a failure occurs in the distant optical path, it is impossible to monitor at the central base station, and a technician can use the measuring equipment It is a reality to visit the site with a device and conduct a test to identify the point of failure of the next stage.

For reference, FIG. 2 shows the degree of loss occurring in an optical network of a typical linear multi-stage configuration. The optical cable distance between FDF (Fiber Distribution Frame), that is, the distance between remote terminals (RT), is 3 km. (Optical cable loss is 0.3dB/km, loss is 0.15dB per optical device connection point, and optical connector loss is about 0.5dB per point). Therefore, even through only 8 FDFs, the loss reaches about 35dB, so it is difficult to monitor the optical lines after that from the center.

In addition, the conventional optical path monitoring system is composed of a linear multi-stage optical network management system and an optical path monitoring system separately. There is a problem in that there is a difference between the location and the location where the actual failure occurs.

FIG. 3 shows a case in which the location of the fifth remote terminal is changed in FIG. 2, and shows an example that is extended by 3 km from the existing optical path. For example, if a failure occurs at a point 1km between the sixth remote terminal (RT#6) and the seventh remote terminal (RT#7), the optical fiber monitoring system predicts that the failure has occurred at 22km {because the fifth remote terminal (RT#7) Since the distance between #5) and the sixth remote terminal (RT#6) is 6 km}, based on this, the optical network management system is located between the seventh remote terminal (RT#7) and the eighth remote terminal (RT#8). It is indicated that an obstacle has occurred at a point of 1 km. In this case, the optical fiber manager excavates a 1km point between the 6th remote terminal (RT#6) and the 7th remote terminal (RT#7) that need repair, and in this process, manpower, time, and money are severely wasted. there is a problem that

In addition, when a remote terminal does not operate due to a failure or power supply failure, there is a problem in that monitoring becomes impossible when a disconnection failure occurs in the optical line of the subsequent stage.

KR 10-2013-0085538 A (2013. 7. 30.)

The present invention has been devised to solve the above problems, and the problem to be solved by the present invention is that it is possible to measure a point of failure between remote terminals by combining built-in or externally coupled to a remote terminal, and a beam capable of bypassing the remote terminal To provide a long-distance optical path monitoring system for a furnace monitoring device and a linear, ring-type, multi-stage connection operation terminal implemented using the same.

An optical path monitoring apparatus according to the present invention is an OTDR module connected to a remote terminal constituting an optical network to measure OTDR, comprising: a light monitoring circuit for generating measurement light and detecting that the measurement light is reflected; and a unidirectional filter connected to the optical monitoring circuit to output measurement light to a second optical fiber connected to the OTDR module, and a third optical fiber connecting the bypass circuit provided in the remote terminal and the unidirectional filter. do it with

A linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention comprises: a network management server for monitoring and controlling the optical ratio constituting an optical network; a central terminal provided between the optical network and the network management server to transmit optical transmission data and OTDR measurement data transmitted from the optical network to the network management server; A long-distance optical path monitoring system comprising a remote terminal distributed in the optical network to enable optical communication in a local area, and an OFD optical distribution box constituting the input/output terminals of the central terminal and the remote terminal, wherein the remote terminal is an Ethernet switch, the A bypass circuit for directly connecting the first optical fiber and the second optical fiber by switching the first optical fiber and the second optical fiber connected to the Ethernet switch, the SFP module connecting the first optical fiber and the second optical fiber to the Ethernet switch, and the Ethernet It consists of a built-in OTDR module connected to a switch in an I2C (Inter Integrated Circuit) method, and the built-in OTDR module generates a measurement light and is connected to a light monitoring circuit to detect the reflected measurement light and the light monitoring circuit for measurement It is composed of a unidirectional filter that outputs only one of the first optical fiber or the second optical fiber, and when the Ethernet switch operates normally, the first optical fiber and the second optical fiber are connected to the Ethernet switch through the SFP module and a remote terminal Networking with loads connected to the ethernet switch, when the Ethernet switch operates abnormally, it is directly connected to the first optical fiber and the second optical fiber through the bypass circuit to pass through the Ethernet switch without passing through the network. do it with

The optical path monitoring apparatus according to the present invention is provided in a remote terminal as an internal or external type, so that it is possible to monitor the optical path in one direction or in both directions.

In addition, by bypassing the remote terminal when the power is turned off or the remote terminal fails, the range of the optical fiber that can be monitored can be expanded.

The linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention is equipped with an optical path monitoring device in the remote terminal, so that long-distance optical path monitoring is possible.

1 is a conventional optical fiber monitoring system
Figure 2 shows the degree of loss (optical connector loss, optical connection loss, optical cable loss) occurs in a general optical network.
3 is a diagram illustrating a case in which the location of the fifth remote terminal in FIG. 2 is changed;
4 is a first embodiment of a linear, ring-type multi-stage connection operating terminal long-distance optical fiber monitoring system according to the present invention;
5 is an example of an OTDR measurement graph displayed in a linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention
6 is an example of a map-type OTDR measurement screen that can be displayed in a linear, ring-type multi-stage connection operation terminal long-distance optical fiber monitoring system according to the present invention;
7 is a detailed configuration diagram of a remote terminal;
8 is a state diagram in use of the first embodiment of the present invention;
9 is a second embodiment of a linear, ring-type multi-stage connection operating terminal long-distance optical fiber monitoring system according to the present invention;
10 is a block diagram of a remote terminal in the second embodiment of the present invention;
11 and 12 are diagrams of a state of use of the second embodiment of the present invention;
13 is a third embodiment of a linear, ring-type multi-stage connection operating terminal long-distance optical fiber monitoring system according to the present invention;
14 is a configuration diagram of a remote terminal and an external OTDR module in the third embodiment of the present invention;
15 is a fourth embodiment of a linear, ring-type multi-stage connection operating terminal long-distance optical fiber monitoring system according to the present invention;
16 is a configuration diagram of a remote terminal and an external OTDR module in the fourth embodiment of the present invention;
17 to 19 are diagrams of use of the third and fourth embodiments of the linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention;
20 to 26 are the fifth and sixth embodiments of the linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention

Hereinafter, the optical path monitoring apparatus and the linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention will be described in detail with reference to the accompanying drawings. For convenience and understanding of the description, the long-distance optical fiber monitoring system of the linear and ring-type multi-stage connection operation terminal will be described first, and then the optical fiber monitoring device will be described.

4 is a first embodiment of a linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention, in which a unidirectional OTDR (Optical Time Domain Reflectometer) module is built-in in the terminal. A first embodiment of a linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention includes OTDR measurement data provided in a central base station, a Central Office Terminal (COT) 20, and a plurality of optical networks provided in the optical network. It consists of two Remote Terminals (RT) 30 and OFD Optical Fiber Distribution 40, ① when a failure such as bending or cutting occurs in the optical path, ② The terminal 30, for example, RT#1 (remote terminal 1, hereinafter referred to as the same method) transmits optical path failure information to the OTDR measurement data, and ③ the network management server 10 sends an OTDR measurement command to RT#1 (or the remote terminal 30 automatically issues a measurement command), ④ using the OTDR module built into RT#1, measures the OTDR of the optical fiber, that is, the distance to the point of failure, and then the network management server (10) ), and ⑤ the network management server 10 uses the transmitted OTDR measurement data to display the location of the failure and displays the OTDR measurement graph, so that the optical path manager can easily identify the failure point.

5 is an example of an OTDR measurement graph displayed in the long-distance optical fiber monitoring system for a linear, ring-type multi-stage connection operation terminal according to the present invention, it can be seen that the failure occurred at about 3 km from the point where the OTDR test was performed.

In the present invention, when the location of the remote terminal 30 and the path of the optical path are stored in the network management server 10 in the present invention, an electronic map or satellite using the location and the path of the optical path of the remote terminal 30 that has performed the OTDR test Points of failure can be displayed in a more intuitive form, such as in a photo. 6 is an example of a map-type OTDR measurement screen that can be displayed in the linear, ring-type multi-stage connection operation terminal long-distance optical fiber monitoring system according to the present invention. It can be intuitively seen that it is near the three-way intersection where Saemunan-ro and Saemunan-ro 5-gil meet, which is the point where #2 is divided by about 1:2.

The network management server 10 is a component that monitors and controls the optical ratio, such as an industrial optical switch constituting an optical network, and includes a location information storage (not shown) in which the location of the remote terminal 30 and the path of the optical path are stored. can do.

The central terminal 20 is provided between the optical network and the network management server 10 and is a component that transmits optical transmission data and OTDR measurement data transmitted from the optical network to the network management server 10 . The detailed configuration of the central terminal 20 is the same as that of the remote terminal 30 .

The remote terminal 30 is a component that is distributed in an optical network to enable optical communication in a local area. 7 is a detailed configuration diagram of the remote terminal 30, in which the remote terminal 30 is an Ethernet switch 31, which is a switching device for Ethernet, and a first optical fiber (F1, for example, an input side) connected to the Ethernet switch 31. A bypass circuit 33 that directly connects the first optical fiber F1 and the second optical fiber F2 by switching the second optical fiber F2 and the second optical fiber F2, the first optical fiber F1 and the second optical fiber ( F2) is an SFP (Small Form Factor) module 35 connected to the Ethernet switch 31 (meaning the input/output terminal of the Ethernet switch 31, the SFP standard is not necessarily required) and I2C ( It is composed of a built-in OTDR module connected by the Inter Integrated Circuit) method, and when the Ethernet switch 31 operates normally, that is, when it functions as a remote terminal, the first optical fiber F1 and the second optical fiber F2 are SFP It is connected to the Ethernet switch 31 through the module 35 to network with loads connected to the remote terminal 30, and bypasses when the Ethernet switch 31 operates abnormally due to a failure, power failure, etc. It is directly connected to the first optical fiber F1 and the second optical fiber F2 through the circuit 33 so that it passes without passing through the Ethernet switch 31 . The reason for making the bypass path in this way is that when there is no bypass path, when the Ethernet switch 31 is abnormal, such as power off, the remote terminal ( 30) also makes networking impossible.

The built-in OTDR module is a component that performs OTDR of the optical path when an OTDR measurement command is received (via I2C) from the network management server 10 through the Ethernet switch 31, and generates measurement light (for example, 1625 nm wavelength band) and a light monitoring circuit 37 for detecting that the measurement light is reflected, and a unidirectional filter 39 connected to the light monitoring circuit 37 and outputting the measurement light only to the second optical fiber F2, which is an output side. Here, unidirectional means only in the measurement light wavelength band, and communication light including data (eg, 1310 nm, 1550 nm wavelength band) may pass through the unidirectional filter 39 in both directions. That is, in the present invention, the unidirectional filter 39 is a wide band stop filter for measuring the opposite direction in which the OTDR is to be measured.

In the present invention, the remote terminal 30 is equipped with a Bluetooth module (not shown), so that a technician near the remote terminal 30 accesses the remote terminal 30 using a portable device such as a smartphone and issues an OTDR measurement command, OTDR measurement data may be transmitted. The reason for such a configuration to enable on-site connection is so that on-site maintenance personnel can directly access the site and quickly identify the point of failure by OTDR measurement, and in the worst case, a failure occurs at both ends of the optical path and is separated from the optical network. This is to enable OTDR measurement within the separated section when there is a remote terminal 30 that operates normally in the designated section. If there is no means available for field access, it is impossible to check the point of failure in the failure section, so it has no choice but to receive and process failure information from the central base station. By doing so, the point of failure can be quickly identified. In addition, if there is another failure in the separated section other than the separated ends, the point of failure cannot be known, but if there is a means that can be accessed in the field, other failure points can be identified by measuring the OTDR from the normally operating remote terminal 30 in the separated section. can

The OFD optical distribution box 40 is a component constituting the input/output terminals of the central terminal 20 and the remote terminal 30, and connects the optical fibers constituting the optical network to the central terminal 20 and the remote terminal 30. It is a component connected to the input/output terminal.

8 is a state diagram of the first embodiment of the present invention, and when OTDR measurement is required, an OTDR measurement command may be issued from the network management server 10 or the smart phone to the remote terminal 30 to determine the failure point.

9 is a second embodiment of a linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention, which enables two-way OTDR measurement like a two-way optical communication network, and for this purpose, a two-way built-in OTDR in the remote terminal 30 A module is provided. 10 is a block diagram of the remote terminal 30 in the second embodiment of the present invention, in which two unidirectional filters 39 are provided inside the built-in OTDR module, respectively, a first optical fiber (F1) and a second optical fiber (F2) The first optical fiber F1 and the second optical fiber F2 each pass through one unidirectional filter 39 to bypass the point at which the measurement light is emitted and the communication light has to pass through both of the two unidirectional filters 39 . It differs from the remote terminal 30 of the first embodiment in that it is connected to the circuit 33 .

Due to this configuration, in the second embodiment of the linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention, bidirectional OTDR measurement (① to ⑤, a to e) as shown in FIG. 9 is possible. In this case, in order to increase the accuracy of the OTDR measurement, even if the failure information is received in either direction, the bidirectional OTDR measurement may be performed. For example, when failure information is reported to the network management server 10 at RT#1, the network management server 10 transmits a forward OTDR measurement command for RT#1 (③) and at the same time as the opposite direction for RT#2. By transmitting (c) the OTDR measurement command, the OTDR measurement can be performed on both sides of the section expected to be a failure. As a result, if the failure points match (RT#1 distance to predicted failure point + RT#2 distance to predicted failure point = distance between RT#1 and RT#2), the probability of failure is very high, and even if it does not It can be inferred with high probability that a failure occurred between the RT#1 predicted failure point and the RT#2 predicted failure point. This operation is possible because the order or topology of each remote terminal 30 is stored in the network management server 10 in the present invention.

11 and 12 are state diagrams of a second embodiment of the present invention, in which RT#1 and RT#2 can measure OTDR in both directions with respect to a failure point, and, for example, RT#2 is abnormal as shown in FIG. By bypassing RT#2, the point of failure where RT#1 is between RT#2 and RT#3 can be tested with RT#3 in both directions with the OTDR. As discussed earlier in [Technology behind the invention], since OTDR measurement is currently possible for up to 8 remote terminals, if 8 remote terminals 30 are not abnormal in succession, OTDR measurement is possible for the entire optical network. If the eight remote terminals 30 are abnormal, it will be said that it is extremely unusual, so it will be possible to monitor a long-distance optical path by the present invention. For reference, it is sufficient if the bypass speed is within 2.05 ms after the occurrence of an abnormality in the remote terminal 30 , and the bypass release speed is sufficient if it is within 2.5 s after the remote terminal 30 is restored.

13 is a third embodiment of the linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention, in the form of having a unidirectional OTDR module 50 outside the remote terminal 30 as an external type. In the third embodiment of the present invention, as shown in FIG. 14 , the remote terminal 30 includes an Ethernet switch 31 , a bypass circuit 33 , and an SFP module 35 , and the external OTDR module 50 is a light monitoring circuit 51 and a unidirectional filter 53, and the Ethernet switch 31 and the optical monitoring circuit 51 are connected by Ethernet. And since the measurement light is output through the external OTDR module 50 , the input side of the first optical fiber F1 is connected to the remote terminal 30 , and the output side of the second optical fiber F2 is connected to the external OTDR module 50 . The third optical fiber F3 is connected between the bypass circuit 33 of the remote terminal 30 and the unidirectional filter 53 of the external OTDR module 50 for bypassing the communication light.

FIG. 15 is a fourth embodiment of a linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention, in which the remote terminal 30 is provided with a bidirectional OTDR module 50 externally. In the fourth embodiment of the present invention, as shown in FIG. 16 , the remote terminal 30 includes an Ethernet switch 31 , a bypass circuit 33 , and an SFP module 35 , and an external OTDR module 50 includes a light monitoring circuit 51 and two unidirectional filters 53 , and the Ethernet switch 31 and the optical monitoring circuit 51 are connected by Ethernet. And since the measurement light is output in both directions through the external OTDR module 50, both the first optical fiber F1 as the input side and the second optical fiber F2 as the output side are connected to the external OTDR module 50, and each one unidirectional filter It is connected to the bypass circuit 33 of the remote terminal 30 via 53 . A third optical fiber (F3) and a fourth optical fiber (F4) are provided between the bypass circuit 33 of the remote terminal 30 and the two unidirectional filters 53 of the external OTDR module 50 for bypass of the communication light, respectively. Connected.

17 to 19 are use state diagrams of the third and fourth embodiments of the linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention, one-way OTDR measurement, two-way OTDR measurement, abnormal remote terminal 30 by It can be seen that the OTDR measurement is possible after the pass. The reason why the third and fourth embodiments of the linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention are necessary is to use a heterogeneous remote terminal 30 or a pre-installed remote terminal 30 according to the present invention. This is to establish a long-distance optical fiber monitoring system for a ring-type multi-stage connection operation terminal.

20 to 26 relate to the fifth and sixth embodiments of the linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention, and the Ethernet switch 31 and optical monitoring in the third and fourth embodiments The connection of the circuit 51 is replaced by WiFi. The fifth and sixth embodiments of the present invention have effects beyond simply changing the communication method between the Ethernet switch 31 and the light monitoring circuit 51 . Because, since the first to fourth embodiments of the linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention use I2C or Ethernet, the remote terminal 30, in particular, whether the Ethernet switch 31 operates normally In the case of the fifth and sixth embodiments, since the OTDR measurement command is possible through the WiFi wireless network in addition to the remote terminal 30, the above dependence is greatly reduced. To this end, in the fifth and sixth embodiments of the linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system according to the present invention, the WiFi module 55 is included in the external OTDR module 50 .

10 Network Management Server 20 Central Terminal
30 Remote Terminal 31 Ethernet Switch
33 Bypass Circuit 35 SFP Module
37, 51 Light monitoring circuit 39, 53 Unidirectional filter
55 WiFi module 40 OFD optical distribution box
50 External OTDR Module

Claims (8)

a network management server 10 for monitoring and controlling the optical ratio constituting the optical network;
a central terminal 20 provided between the optical network and the network management server 10 to transmit optical transmission data and OTDR measurement data transmitted from the optical network to the network management server 10;
a remote terminal 30 distributed in the optical network to enable optical communication in a local area; and
A linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system consisting of an OFD optical distribution box 40 constituting the input and output terminals of the central terminal 20 and the remote terminal 30,
The remote terminal 30 switches the Ethernet switch 31, the first optical fiber F1 and the second optical fiber F2 connected to the Ethernet switch 31, so that the first optical fiber F1 and the second optical fiber (F1) and the second optical fiber ( A bypass circuit 33 directly connecting F2), an SFP module 35 in which the first optical fiber F1 and the second optical fiber F2 are connected to an Ethernet switch 31, and I2C to the Ethernet switch 31 It consists of a built-in OTDR module connected in an (Inter Integrated Circuit) method,
The built-in OTDR module of the remote terminal 30 generates measurement light and is connected to a light monitoring circuit 37 for detecting that the measurement light is reflected and the light monitoring circuit 37 to transmit the measurement light to the first optical fiber, respectively. (F1) and the second optical fiber (F2) provided with two unidirectional filters (39), and the first optical fiber (F1) and the second optical fiber (F2) are respectively connected to each other via a unidirectional filter (39). It is a bidirectional built-in OTDR module to be connected to the bypass circuit (33),
When the Ethernet switch 31 operates normally, the first optical fiber F1 and the second optical fiber F2 are connected to the Ethernet switch 31 through the SFP module 35 and the load connected to the remote terminal 30 ( loads), and when the Ethernet switch 31 operates abnormally, it is directly connected to the first optical fiber F1 and the second optical fiber F2 through the bypass circuit 33 to connect the Ethernet switch ( 31) A linear, ring-type multi-stage connection operation terminal long-distance optical fiber monitoring system, characterized in that it passes without passing through.
delete a network management server 10 for monitoring and controlling the optical ratio constituting the optical network;
a central terminal 20 provided between the optical network and the network management server 10 to transmit optical transmission data and OTDR measurement data transmitted from the optical network to the network management server 10;
a remote terminal 30 distributed in the optical network to enable optical communication in a local area;
OFD optical distribution box 40 constituting the input and output terminals of the central terminal 20 and the remote terminal 30, and
A linear, ring-type multi-stage connection operation terminal long-distance optical path monitoring system having an external OTDR module 50 for OTDR testing the optical network,
The remote terminal 30 is connected to an Ethernet switch 31, a bypass circuit 33 connected to the Ethernet switch 31, and an SFP module 35 connecting the Ethernet switch 31 and the bypass circuit 33. A first optical fiber (F1) and a second optical fiber (F2) are connected to the bypass circuit (33),
The external OTDR module 50 generates measurement light and is connected to a light monitoring circuit 51 for detecting that the measurement light is reflected and the light monitoring circuit 51 to transmit the measurement light to the first and second optical fibers ( It consists of two unidirectional filters 53 that output to F1 and F2), and the Ethernet switch 31 and the optical monitoring circuit 51 are connected in an Ethernet manner,
The first and second optical fibers F1 and F2 are respectively connected to the bypass circuit 33 of the remote terminal 30 through one unidirectional filter 53 , and bypass of the remote terminal 30 . Linear, ring-type multi-stage connection operation terminal long-distance, characterized in that the third optical fiber (F3) and the fourth optical fiber (F4) are respectively connected between the circuit 33 and the two unidirectional filters 53 of the external OTDR module 50 Fiber optic monitoring system.
delete 4. The method according to claim 3,
The external OTDR module 50 is configured to further include a WiFi module 55, so that an OTDR measurement command is possible to a wireless network other than the optical network.
4. The method according to claim 1 or 3,
Linear and ring type multi-stage connection operation terminal long-distance optical path, characterized in that a Bluetooth module is provided in the remote terminal 30 to connect to the remote terminal 30 as a portable device, issue an OTDR measurement command, and receive OTDR measurement data surveillance system.
4. The method according to claim 1 or 3,
OTDR measurement graph or map-type OTDR measurement screen is displayed on the network management server (10) Linear, ring-type multi-stage connection operation terminal long-distance optical fiber monitoring system, characterized in that the display. delete

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