KR20230131001A - Passive device for OTDR measurement for diagnosing the condition of optical cables - Google Patents

Abstract

The present invention relates to a passive element for OTDR measurement for diagnosing the condition of an optical cable, and more specifically, to a passive element for OTDR measurement that is coupled to transmission equipment to diagnose the condition of an optical cable.
To this end, the passive element for OTDR measurement for diagnosing the condition of an optical cable of the present invention includes a fourth terminal that receives an optical pulse from a first passive element for OTDR measurement connected to an OTDR measurement device; and a seventh terminal that transmits the optical pulse received from the fourth terminal to the third OTDR measurement terminal.

Description

Passive device for OTDR measurement for diagnosing the condition of optical cables}

The present invention relates to a passive element for OTDR measurement for diagnosing the condition of an optical cable, and more specifically, to a passive element for OTDR measurement that is coupled to transmission equipment to diagnose the condition of an optical cable.

The method mainly used in conventional optical networks for long-distance optical communication is to convert an electrical signal into an optical signal using a laser diode, transmit the converted optical signal through an optical cable, and when transmitting through the optical cable, This is a method of communicating by converting a weakened optical signal due to loss caused by an optical cable back into an electrical signal, amplifying it, and then converting the amplified electrical signal back into an optical signal.

However, optical cables that transmit optical signals have a very high risk of disconnection due to the surrounding environment or bending phenomenon. Therefore, the transmission of optical signals is interrupted or the smooth transmission of optical signals is not achieved due to the bending of the optical cable.

In this optical cable monitoring technology, a common device for measuring the fault condition of an optical cable is an OTDR (Optical Time Domain Reflectometer) measurement device. This OTDR measuring device applies an optical pulse to an optical cable and analyzes the reflected light returning according to the distance distribution of the light amount, measuring the distance to the loss connection point of the optical fiber, the connection loss, and the reflection amount from the connection point to the breakage point when the fiber is damaged. Measure distance, etc. Here, reflected light refers to light being reflected in a place where the refractive index of the optical fiber is non-uniform and returning in the direction of the light source. This OTDR measuring device is widely used as a measuring instrument for construction and repair of optical cables. In addition, the OTDR measuring device is a device with high resolution and is relatively expensive, so it is mainly carried and used by only experts who specialize in maintaining optical cables to inspect the condition of optical fibers.

The OTDR measuring device, which measures failure points or loss characteristics of optical fibers using this OTDR method, is installed coupled to transmission equipment to diagnose the condition of the optical cable between both ends of the transmission equipment in real time. However, when the distance between both ends of two transmission devices is short, there is the inconvenience of having to install an OTDR measurement device for each transmission device in order to diagnose the status of the optical cable in real time.

Korean Patent Publication No. 2006-0079281 (Title of invention: Optical cable line failure monitoring system and monitoring method) Korean Patent Publication No. 2009-0100109 (Invention Title: Optical subscriber network optical cable monitoring device and method using optical pulse type)

The problem to be solved by the present invention is to propose a passive device for diagnosing the condition of an optical cable.

Another problem that the present invention aims to solve is to propose a passive device that can easily diagnose the status of optical cables even when the distance between transmission equipment is long.

To this end, the passive element for OTDR measurement for diagnosing the condition of an optical cable of the present invention includes a fourth terminal that receives an optical pulse from a first passive element for OTDR measurement connected to an OTDR measurement device; and a seventh terminal transmitting the optical pulse received from the fourth terminal to a third OTDR measurement terminal.

The passive element for OTDR measurement for diagnosing the condition of an optical cable according to the present invention can reduce the number of OTDR measurement devices by arranging the minimum number of passive elements for OTDR measurement even if the number of transmission equipment disposed on the optical cable increases. By reducing the number of OTDR measurement devices that diagnose the condition of optical cables, it is possible to increase cost and management efficiency.

Figure 1 shows a diagnostic system for diagnosing the state of an optical cable according to an embodiment of the present invention.
Figure 2 shows a diagnostic system for diagnosing the state of an optical cable according to another embodiment of the present invention.
Figure 3 shows the structure of a passive element for OTDR measurement according to an embodiment of the present invention.
Figure 4 shows the structure of a second passive element for OTDR measurement according to an embodiment of the present invention.
Figure 5 shows the structure of a 4-port-LPF according to an embodiment of the present invention.
Figure 6 shows the structure of a 5-port-HPF according to an embodiment of the present invention.

The foregoing and additional aspects of the present invention will become more apparent through preferred embodiments described with reference to the accompanying drawings. Hereinafter, these embodiments of the present invention will be described in detail so that those skilled in the art can easily understand and reproduce them.

Figure 1 shows a diagnostic system for diagnosing the state of an optical cable according to an embodiment of the present invention. Hereinafter, we will look at a method of diagnosing the state of an optical cable according to an embodiment of the present invention using Figure 1.

According to Figure 1, the diagnostic system 100 for diagnosing the state of an optical cable includes transmission equipment A (110), transmission equipment B (120), and transmission equipment C (130), and also includes an OTDR measurement device 140. . Looking at this in detail, in order to diagnose the condition of an optical cable or transmit an optical signal using an optical cable, transmission equipment A (110) to transmission equipment C (130) are sequentially arranged on the optical cable, and the arranged transmission equipment is used. This amplifies the optical signal or performs other necessary functions.

A plurality of optical cables are arranged between transmission equipment A (110) and transmission equipment B (120), and a plurality of optical cables are also arranged between transmission equipment B (120) and transmission equipment C (130). One optical cable transmits optical signals in the first direction from transmission equipment A (110) to transmission equipment C (130), and the other optical cable transmits optical signals in the first direction from transmission equipment C (130) to transmission equipment A (110). Transmits optical signals in two directions.

According to Figure 1, in order to diagnose the status of a plurality of optical cables arranged between transmission equipment A (110) and transmission equipment B (120), two OTDR measuring devices (140-1, 140-2) are connected to each optical cable. In order to diagnose the status of a plurality of optical cables arranged between transmission equipment B (120) and transmission equipment C (130), two OTDR measuring devices (140-3, 140-4) are connected to each optical cable. . As an example, the first OTDR measurement device (140-1) and the second OTDR measurement device (140-2) diagnose the status of the optical cable placed between transmission equipment A (110) and transmission equipment B (120), and the third The OTDR measurement device 140-3 and the fourth OTDR measurement device 140-4 diagnose the status of the optical cable disposed between transmission equipment B (120) and transmission equipment C (130).

As such, the present invention proposes a method of diagnosing the condition of an optical cable using an OTDR measuring device. However, in the diagnostic system for diagnosing the state of the optical cable proposed in Figure 1, as the number of transmission equipment increases, the number of OTDR measurement devices for diagnosing the state of the optical cable also increases. As mentioned above, the OTDR measurement device that diagnoses the condition of the optical cable is an expensive equipment, so as the length of the optical cable increases, installation costs and management difficulties become more difficult. Accordingly, the present invention proposes a passive element for OTDR measurement to solve the above-mentioned problems.

Figure 2 shows a diagnostic system for diagnosing the state of an optical cable according to another embodiment of the present invention. Hereinafter, we will look at a method of diagnosing the state of an optical cable according to another embodiment of the present invention using FIG. 2.

According to Figure 2, the system 200 for diagnosing the state of the optical cable includes transmission equipment A (210), transmission equipment B (220), and transmission equipment C (230), and in addition, an OTDR measurement device 240 and an OTDR measurement device Includes a passive element (250). As described above, the diagnostic system can see that transmission equipment A (210) to transmission equipment C (230) are arranged sequentially.

A plurality of optical cables are arranged between transmission equipment A (210) and transmission equipment B (220), and a plurality of optical cables are also arranged between transmission equipment B (220) to transmission equipment C (230). One optical cable transmits optical signals in the first direction from transmission equipment A (210) to transmission equipment C (230), and the other optical cable transmits optical signals in the first direction from transmission equipment C (230) to transmission equipment A (210). Transmits optical signals in two directions.

According to Figure 2, two OTDR measuring devices (240-1, 240-2) are connected respectively to diagnose the status of the optical cable placed between transmission equipment A (210) and transmission equipment C (230). In particular, the first The first OTDR measuring device 240-1 is connected to the optical cable arranged in the first direction, and the second OTDR measuring device 240-2 is connected to the optical cable arranged in the second direction. In addition, a separate OTDR measurement device is not connected to transmission equipment B (220) disposed between transmission equipment A (210) and transmission equipment C (230). However, passive elements for OTDR measurement are placed in transmission equipment B.

The passive element 250 for OTDR measurement performs a function of bypassing the optical pulse received from the OTDR measurement device 240. The structure of the passive element for OTDR measurement will be examined in detail in FIG. 3.

Figure 3 shows the structure of a passive element for OTDR measurement according to an embodiment of the present invention. Hereinafter, the structure of a passive element for OTDR measurement according to an embodiment of the present invention will be examined in detail using FIG. 3.

As shown in FIG. 3, in the optical cable diagnosis system 200, transmission equipment A 210 to transmission equipment C 230 are placed at designated locations to transmit optical signals using optical cables. Additionally, the optical cable diagnosis system includes an ODTR measurement device 240 to diagnose the condition of the optical cable, and also includes a passive element 250 for OTDR measurement as described above.

Below, we will look at the passive element 250 for OTDR measurement. The passive element 250 for OTDR measurement includes a first OTDR measurement passive element 250-1 to a third OTDR measurement passive element 250-3. The first OTDR measurement passive element 250-1 has the same structure as the third OTDR measurement passive element 250-3.

The first OTDR measurement passive element (250-1) is connected to transmission equipment A (210), transmits and receives optical signals with transmission equipment A (210), and transmits and receives optical signals from the first OTDR measurement device (240-1). Pulses are transmitted through optical cables. For this purpose, the first OTDR measurement passive element 250-1 has four terminals.

The first terminal of the first OTDR measurement passive element (250-1) is a receiving terminal that receives an optical signal from transmission equipment A (210), and the second terminal is a transmission terminal that transmits an optical signal to transmission equipment A (210). It is a terminal. The third terminal is a terminal that receives an optical signal from transmission equipment B (the second passive element for OTDR measurement) or transmits an optical pulse for diagnosing the condition of the optical cable, and the fourth terminal receives an optical signal from transmission equipment B (220). This is a transmitting terminal that transmits.

The second OTDR measurement passive element (250-2) is connected to transmission equipment B (220) and transmits and receives optical signals with transmission equipment B (220). The second OTDR measurement passive element 250-2 has eight ports as shown in FIG. 3. Below, we will look at the signals transmitted and received at each port in detail.

The first terminal is connected to transmission equipment B (220), receives an optical signal from transmission equipment B (220), and the received optical signal is transmitted to transmission equipment A (210) through the fourth terminal. The third terminal receives an optical signal from transmission equipment A (210), and the received optical signal is transmitted to transmission equipment B (220) through the second terminal. As shown in FIG. 3, a 1-4 port-LPF (250-2a) is disposed between the first and fourth terminals, and a 1-5 port-HPF (250) is disposed between the second and third terminals. -2b) is placed. The functions of the 4-port-LPF and 5-port-HPF will be described later. In addition, the fourth terminal receives an optical pulse from the first OTDR measurement passive element (250-1), and the received optical pulse is blocked (reflected) from passing through the 1-4 port-LPF (250-2a) to the first OTDR measurement passive element (250-1). It is delivered to 2-5 port-HPF (250-2d).

The fifth terminal is connected to transmission equipment B (220), receives an optical signal from transmission equipment B (220), and the received optical signal is transmitted to transmission equipment C (230) through the eighth terminal. The seventh terminal receives an optical signal from transmission equipment C (230), and the received optical signal is transmitted to transmission equipment B (220) through the sixth terminal. As shown in FIG. 3, a 2-4 port-LPF (250-2c) is disposed between the 5th and 8th terminals, and a 2-5 port-HPF (250) is disposed between the 6th and 7th terminals. -2d) is placed.

The seventh terminal receives an optical pulse from the 2-5 port-HPF (250-2d) and transmits the received optical pulse to the transmission equipment C (230).

The fourth terminal of the first OTDR measurement passive element (250-1) is connected to the third terminal of the second OTDR measurement passive element (250-2), and the first OTDR measurement passive element (250-1) is connected to the third terminal of the second OTDR measurement passive element (250-1). The third terminal is connected to the fourth terminal of the second OTDR measurement passive element (250-2).

The third OTDR measurement passive element (250-3) is connected to transmission equipment C (230), transmits or receives optical signals to transmission equipment C (230), and receives them from the second OTDR measurement device (240-2). An optical pulse is transmitted through an optical cable. For this purpose, the third passive element for OTDR measurement (250-3) has four terminals, the first terminal is a receiving terminal for receiving an optical signal from transmission equipment C (230), and the second terminal is a reception terminal for receiving optical signals from transmission equipment C (230). ) is a transmitting terminal that transmits an optical signal from, and the third terminal is a receiving terminal that receives an optical signal from an optical cable connected to transmission equipment B (220), and the fourth terminal is an optical signal connected to transmission equipment B (220). This is a terminal that transmits or receives light pulses.

The fourth terminal of the third OTDR measurement passive element (250-3) is connected to the seventh terminal of the second OTDR measurement passive element (250-2), and the third OTDR measurement passive element (250-3) is connected to the fourth terminal of the third OTDR measurement passive element (250-3). The third terminal is connected to the eighth terminal of the second OTDR measurement passive element (250-2).

In addition, the terminal for transmitting optical signals proposed in the present invention can be converted into a terminal for receiving optical signals, and the terminal for receiving optical signals can be converted into a terminal for transmitting optical signals. That is, the terminal can be converted into a terminal for transmitting optical signals or a terminal for receiving optical signals, if necessary.

Figure 4 shows the structure of a second passive element for OTDR measurement according to an embodiment of the present invention. Hereinafter, the structure of the second passive element for OTDR measurement according to an embodiment of the present invention will be examined using FIG. 4.

As described above, the second passive element for OTDR measurement includes a 4-port LPF and a 5-port HPF inside. In particular, the 1-4th port-LPF is disposed between the first terminal and the fourth terminal, and the 1-5th port-HPF is disposed between the second terminal and the third terminal. In addition, the 2-4th port-LPF is disposed between the 5th terminal and the 8th terminal, and the 2-5th port-HPF is disposed between the 6th terminal and the 7th terminal.

The optical pulses blocked from passing through the 1-4 port-LPF are transmitted to the 2-5 port-HPF, and the optical pulses blocked from passing through the 2-4 port-LPF are transmitted to the 1-5 port-HPF. Below, we will look at 4-port-LPF and 5-port-HPF.

Figure 5 shows the structure of a 4-port-LPF according to an embodiment of the present invention. Hereinafter, the structure of the 4-port LPF according to an embodiment of the present invention will be described in detail using FIG. 5.

In general, the wavelength of an optical signal transmitted through an optical cable is 1260 to 1617 nm, while the wavelength of an optical pulse for diagnosing an optical cable is 1622.5 to 1670 nm. That is, the wavelength of the optical pulse is relatively high compared to the optical signal. Therefore, using LPF, optical signals with relatively low wavelengths are passed through and transmitted to transmission equipment B, and optical pulses with relatively high wavelengths are reflected (blocked from passing). Referring to FIG. 4, the optical pulse input to the fourth terminal is blocked from passing by the 4-port-LPF and is transmitted to the 5-port-HPF, and the optical signal input to the first terminal passes through the 4-port-LPF. It is transmitted through the fourth terminal.

Figure 6 shows the structure of a 5-port-HPF according to an embodiment of the present invention. Hereinafter, the structure of the 5-port-HPF according to an embodiment of the present invention will be described in detail using Figure 6.

In general, the wavelength of an optical signal transmitted through an optical cable is 1260 to 1617 nm, while the wavelength of an optical pulse for optical cable diagnosis is 1622.5 to 1670 nm. Therefore, using HPF, light pulses with relatively high wavelengths are passed through and transmitted to transmission equipment C. Additionally, the optical signal that is blocked from passing is re-incident to the HPF and is blocked from passing. Since the optical signal re-incident to the HPF is blocked from passing through, there are no optical pulses passing through Pass(2), so the port can be removed. In this way, by repeatedly blocking the passage of optical signals, the isolation characteristics are improved. In other words, it is possible to process tasks performed in two modules using one module.

As such, the present invention proposes a method of diagnosing the state of an optical cable without distance limitations using a passive element for OTDR measurement.

The present invention has been described with reference to an embodiment shown in the drawings, but this is merely illustrative, and those skilled in the art will understand that various modifications and other equivalent embodiments are possible therefrom. .

100, 200: Optical cable diagnosis system 110, 210: Transmission equipment A
120, 220: Transmission equipment B 130, 230: Transmission equipment C
140, 240: OTDR measuring device
250: Passive element for OTDR measurement

Claims (8)

a fourth terminal that receives an optical pulse from a first OTDR measurement passive element connected to the OTDR measurement device; and
A passive element for OTDR measurement for diagnosing the condition of an optical cable, including a second OTDR measurement device including a seventh terminal that transmits the optical pulse received from the fourth terminal to the third OTDR measurement terminal.
The method of claim 1, wherein a 1-4 port-LPH and a 1-5 port-HPF are disposed between the fourth and seventh terminals of the second OTDR measuring device. Passive elements for OTDR measurement.
The method of claim 2, wherein the second OTDR measuring device is connected to transmission equipment B through two terminals,
The first terminal of the second OTDR measuring device receives or transmits an optical signal from the transmission equipment B,
The sixth terminal of the second OTDR measurement device is a passive element for OTDR measurement for diagnosing the condition of an optical cable, characterized in that it transmits or receives an optical signal to the transmission equipment B.
The method of claim 2, wherein the 1-4 port-LPH has 4 ports,
Among the optical pulses and optical signals input to the first port, an optical signal with a relatively low wavelength is passed through and transmitted to the first terminal via a second port,
A passive element for OTDR measurement for diagnosing the condition of an optical cable, characterized in that an optical pulse with a relatively high wavelength is passed through and transmitted to the 1st-5th port-HPF via a third port.
The method of claim 4, wherein the 1-5 port-HPF has 5 ports,
Among the optical pulses and optical signals input to the first port, the optical pulse with a relatively high wavelength is passed through and delivered to the seventh terminal via the second port,
Optical signals with relatively low wavelengths are blocked from passing, output to the third port, and then re-incident to the fourth port.
A passive element for OTDR measurement for diagnosing the condition of an optical cable, characterized in that the re-incident optical signal is blocked from passing and transmitted to the sixth terminal via the fifth port.
The method of claim 5, wherein the second OTDR measuring device,
Two 4-port-LPHs including the 1st-4th port-LPH are arranged,
A passive element for OTDR measurement for diagnosing the condition of an optical cable, characterized in that two 5-port HPFs including the 1st-5th port-HPF are arranged.
The method of claim 6, wherein the second OTDR measuring device,
A passive element for OTDR measurement for diagnosing the condition of an optical cable, comprising 8 terminals when connected to the first OTDR measurement device or the third OTDR measurement device through two optical cables.
The passive element for OTDR measurement for diagnosing the condition of an optical cable according to claim 7, wherein the wavelength of the optical signal is 1260 to 1617 nm, and the wavelength of the optical pulse is 1622.5 to 1670 nm.

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