JPH03249828A - Method for isolating fault position of optical transmission line and fault position isolating device - Google Patents

Abstract

PURPOSE:To instantaneously isolate the faults in an optical line and a transmitter by transferring light to an outgoing conductor when the insertion conductor of the light to be tested is an incoming conductor, and to the incoming conductor in an opposite case, taking out the light by means of a photocoupler installed on the inner side of a station in the same conductor, receiving it in a light receiver and isolating the fault in the optical line and the transmitter in accordance with the presence or absence of the light. CONSTITUTION:The light is demultiplexed by the photocoupler 4 inserted into the outgoing conductor, and it passes through an optical filter for interrupting communication light 10, where the light is subjected to phometry by a light receiver 9. When the fault such as breaking is present in the optical line, the light cannot be received and it is detected to be the line fault. Then, the light is reflected by the optical filter 7 and inserted into an optical fiber for test light transmission 5c. The optical fiber 5c is connected to the other side and it forms a loop between the incoming and outgoing conductors on the light. Thus, the fault can instantaneously be isolated by an operation from inside the station.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for highly accurate, high-speed, and simple isolation of failures in optical lines and transmission equipment from within a station.

"Conventional technology and its issues" When using a light source and a receiver to isolate a fault between an optical line and a transmission device, conventionally, after a fault occurs in an optical transmission line, a line maintainer can contact the station by telephone, etc. A light source is brought inside and a receiver is brought to the subscriber side.The light source is connected to the faulty core inside the station and a test light is inserted.On the subscriber side, a maintenance person uses the first receiver from the vicinity of the transmission equipment. The test light was received and failures were isolated based on the presence or absence of the light. Therefore, it takes a long time for maintenance staff to rush to the system and troubleshoot the problem, and the time required to recover from the failure is extremely long. Also, since it was necessary to go to the subscriber's home, it caused a great deal of inconvenience, especially late at night.

The present invention has been made in view of the above circumstances, and includes:
An object of the present invention is to provide a method and device for automatically identifying failures between optical lines and transmission equipment from within the station.

"Means for Solving the Problems" In order to achieve the above object, the first invention provides a method for isolating a failure between an optical line and a transmission device using a light source and a light receiver. Insert test light of a different wavelength from the optical coupler into either the upstream or downstream core wire, and pass only the above test light from the upstream core to the downstream core in the vicinity of the transmission equipment on the subscriber side outside the station. To isolate the fault position to be transmitted, place a device to transmit only the above test light to the above fault location. The test light is transmitted to the center, extracted by an optical coupler installed inside the center of the concentric line, and received by a light receiver, and the presence or absence of this test light is used to isolate failures between the optical line and the transmission equipment. The conventional technology is that automatic fault isolation tests are performed from inside the station, a first coupler is placed inside the station, and only the test wavelength light is sent to the subscriber side outside the station.
The difference is that a fault isolator is provided that has the function of passing between the downlink cores.

In the second invention, the position cut shown in the first invention is provided between the filters provided on each of the up and down core wires to reflect the test light, and the filters provided between these filters to reflect the test light. It is configured to include a test light propagation optical fiber through which the test light is propagated.

In the third invention, the positional division shown in the first invention includes a pair of optical waveguides connected to each core wire and provided so as to intersect with each other, and a device provided at the intersection of the optical waveguides. and a filter that reflects the test light supplied through one waveguide and propagates it to the other optical waveguide.

In the fourth invention, the fault location isolation shown in the first invention is performed by the third and fourth waveguides that intersect with the first and second waveguides connected to the respective down and up core wires of the device. A filter that reflects the test light and passes the communication light is installed at each intersection, and a total reflection plate is installed at the intersection of the third and fourth waveguides, so that the test light falls. The core wire is inserted from the first waveguide, reflected by the filter, inserted into the third waveguide, reflected by the total reflection plate, inserted into the fourth waveguide, reflected again by the filter, and then inserted into the second waveguide. It is inserted into the waveguide, propagates to the upstream core, and propagates along the opposite path to the above.

"Operation" According to the first invention, when the test light cannot be received by the optical receiver, it can be determined that there is a failure such as a break in the core wire, and that there is a line failure. Furthermore, if the test light can be received by the optical receiver, it can be determined that the transmission device is malfunctioning.

According to the second, third, and fourth inventions, the test light supplied through one core wire is reflected by one or a pair of two filters and propagated to the other core wire. Thereby, only the test light can be selectively propagated through these core wires.

"Example" FIG. 1 is a diagram illustrating a first example of the present invention,
1 is a transmission device, and 2 is a communication light λ. , 3 is the light receiving part of the communication destination, 4 is the optical coupler, 5 (58 to 5C) is the optical fiber, 6 is the first failure isolation device, 7 is the optical filter for removing the test light, 8 is the test A light emitting part, 9 a receiver for test light λ1, I
O is a communication light removal destination filter, and 11 is a control device. To carry out this method, first, test light is inserted from the test light emitting section 8 into the downlink core wire 5a. This test light is reflected by an optical filter and is connected to a test light propagation optical fiber 5c.
It is reflected by the optical filter 71 of the downlink fiber 5b, inserted into the downlink fiber 5b, and propagated toward the inside of the station.

The test light is branched by the optical coupler 4 inserted into the downlink cable 5b, passes through the communication destination blocking optical filter 10, and can be measured by the light receiver 9. If there is a failure such as a break in the optical line, the test light cannot be received, indicating a line failure. Figure 2 shows the flow of fault isolation. When an alarm indicating that a failure has occurred in the transmission device occurs (Step 1), the test light generator 8 (LD
A test light is generated from .lambda., ), and a fault isolation operation is performed (step 2), and it is determined whether the optical line or the transmission device is at fault (steps 3 to 5). In other words, the test light receiver 9
If the test light is received at the test light receiver 9, it is determined that the transmission device 1 is malfunctioning (steps 3 and 4), and if the test light receiver 9 does not receive the test light, the core of the optical path is detected. Line 5a・
5b failure (Steps 3 and 5).

Next, with reference to FIG. 3, a specific example of the configuration of the first fault isolation device 6 shown in FIG. 1 will be explained.

Here, 12 is a housing, and 13 is a hood part. The test light λ is reflected by the optical filter and inserted into the test light propagation optical fiber 5C. This optical fiber 5C is connected to the other end and forms a loop between the upstream and downstream fibers for the test light.

With the above configuration, failures can be isolated instantaneously by operations within the station. As is clear from these results, compared to the conventional method, there is an improvement in that failure recovery time can be shortened and serviceability can be improved.

4 to 6 show a second embodiment of the present invention, and 14 is a second and third failure isolation device. The implementation of this method is similar to the first embodiment shown in FIG. 1, but the failure isolation differs from the first embodiment in the configuration of the device 14. FIG. 4 shows a schematic diagram of the overall configuration, and FIGS. 5 and 6 show specific examples of the configuration of the second and third failure division devices 14.

In the following second and third embodiments, the same reference numerals are given to parts having the same configuration as in the first embodiment to simplify the explanation.

The failure isolation device 14 shown in FIG. 5 has a structure in which the upstream and downstream core wires intersect within the device, and an optical filter 7 is inserted at the intersection. Moreover, the fault isolation device 14 shown in FIG.
A waveguide circuit is used at the intersection of the two, and the size can be significantly reduced compared to the fiber type shown in FIG. Here, 15 is an optical fiber core, 16 is a silicon substrate or a glass substrate,
17 is a waveguide. In these cases, compared to the first embodiment, only one optical filter 7 is required, the test light propagation optical fiber 5C is unnecessary, and the cutting device can be constructed economically. Other effects are similar to those of the first embodiment.

FIG. 7 shows a third embodiment of the present invention, in which 18 is an optical filter for blocking test light, 19 is an optical matrix switch, and 2
0 is a modem, and 21 is a remote control device. The execution form of this method is similar to the first example and the second example, but
Since the test light blocking optical filter 18 is inserted close to the transmission equipment inside the station, the transmission quality is not affected even if the test is performed without considering the level of the inserted test light, and the optical matrix
Remote automatic disconnection can be tested from any position using the two-way switch 19 and the remote control device 21. Other effects are similar to those in the first and second embodiments.

FIG. 8 shows a fourth embodiment of the present invention, and 23 indicates the first,
Second, third, and fourth waveguides 17 a s 17 b 5
The fourth failure section is the device 23, which is composed of the optical filters 17c and 17'c, the optical filter 7, the total reflection plate 22, and the like.

Next, the operation of the fault isolation device 23 will be explained.

An optical filter 7 is inserted at the intersection of the first and third waveguides 17a and 17c and the second and fourth waveguides 17b and 17'c, and the test light is reflected by the optical filter 7 and passes through the waveguide 17a.
It propagates from 17c to 17b, from 17'c to 17b, or in the reverse direction. Further, a total reflection plate 22 is installed at the intersection of the waveguides 17c and 17'c, and the test light is totally reflected by this total reflection plate 22, so that the test light is reflected from the waveguide 17c to 17'c.
or vice versa.

Therefore, as shown in FIG. 8, the test light λ is inserted into the first waveguide 17a from the downstream optical fiber 5a, reflected by the optical filter 7, inserted into the third waveguide 17C, and then passed through the total reflection plate. 22 and inserted into the fourth waveguide 17'c,
It is reflected by the optical filter 7, inserted into the second waveguide 17b, and then inserted into the upstream optical fiber 5b. Moreover, the reverse path can also be propagated. Further, the communication destination passes through the optical filter 7 as it is and propagates. The waveguide [17d] is processed to have an angle of 10c' or more at the tip to prevent reflection.

In the second and third embodiments shown in FIGS. 5 and 6, the communication light itself may be reflected by the optical filter and inserted into the light receiver of the same transmission device.

For example, in FIG. 7, LDλ of DSUI. 2?

strong signal light λ emitted from is reflected by the filter and inserted into the PD3. In this case, LDλ of 0CUl
. Signal light λ emitted from 2. becomes a weak optical signal due to line loss, and is received by PD3 of the DSUI. Therefore, in areas where line loss is large, the transmission quality deteriorates significantly due to the above-mentioned reflected light, and it may become impossible to transmit signals.

In the fourth embodiment shown in FIG. 8, since the uplink and downlink lines do not intersect, there is an effect that the signal transmission quality does not deteriorate due to the reflection of signal light as described above. Other effects are similar to those of the third embodiment.

FIG. 9 shows a fourth embodiment of the present invention, and the fourth section shows a system configuration to which the device 23 is applied.

The operation and effects of the system are similar to those of the third embodiment. 2
4 is a database.

FIG. 10 is a flowchart showing the operation of the fourth embodiment shown in FIG. In this case, since the method compares the test light level measured in advance during normal operation and the case at the time of failure, it is possible to isolate the failure with higher accuracy than the method shown in FIG. 2.

"Effects of the Invention" As explained above, according to the present invention, it is possible to instantly isolate failures between optical lines and transmission equipment, and countermeasures can be taken quickly, thereby shortening failure recovery time and improving serviceability. There are advantages that can be improved.

[Brief explanation of drawings]

1 to 3 are diagrams showing the first embodiment of the present invention, in which FIG. 1 is a schematic diagram of the overall configuration, FIG. 2 is a flowchart showing the control contents of the CPU, and FIG. 4 to 6 are diagrams showing the second embodiment,
Fig. 4 is a schematic diagram of the overall configuration, Fig. 5 is a diagram showing the second failure division, and Fig. 6 is a diagram showing the third failure division,
FIG. 7 is an overall schematic diagram showing the third embodiment. 8th
The figure shows a fourth failure isolation device, and FIGS. 9 and 10 are diagrams for explaining the fourth embodiment of the present invention. DESCRIPTION OF SYMBOLS 1...Transmission device, 2...Communication light emitting section, 3...Communication light receiving section, 4...Optical coupler, 5... ...Optical fiber (5a...core wire,
5b... Core wire, 5c... Optical fiber for test light propagation)
, 6... First fault segment is a device, (first fault location segment is a device), 7...-... Optical filter for blocking test light, 8... Test light emitter, 9. Old... Test light receiver, 10... Optical filter for blocking communication destination, 1
1... Control device, 12... Housing, 13... Cord, 14... Second and third fault isolation device (second and third The third failure location is the device), 15... Optical fiber core, 16...
・Silicon substrate or glass substrate, 17... Waveguide, 18. Old... Optical filter for blocking test light, 19...
...Optical matrix switch, 20...Modem, 21...Remote control device, 22...
Total reflection plate, 23...Fourth failure cutoff is vessel, 24
・・・・・・Database

Claims (4)

[Claims] (1) In a method for isolating failures between optical lines and transmission equipment using a light source and receiver, a test light of a wavelength different from the communication light is transmitted from inside the station to one of the upstream or downstream core wires through an optical coupler. A fault location isolator is placed near the transmission equipment on the outside subscriber side to transmit only the test light from the uplink core to the downlink core, and only the test light is isolated to the fault location. If the inserted core wire is an up core wire, the above test light is propagated to the down core wire, and in the opposite case, it is propagated to the up core wire, and is taken out by an optical coupler installed inside the center of the concentric wire and sent to an optical receiver. A method for locating a fault in an optical transmission line, characterized in that the fault is isolated between the optical line and the transmission device based on the presence or absence of this test light. (2) The fault location isolator described in item (1) above,
It is made up of a filter that is installed on each upstream and downstream core wire to reflect the test light, and an optical fiber for propagating the test light that is installed between these filters to propagate the reflected test light. Features: Fault location isolater for optical transmission lines. (3) The fault location isolator described in item (1) above,
A pair of optical waveguides connected to each of the core wires and provided so as to intersect with each other; and a pair of optical waveguides provided at the intersection of the optical waveguides to reflect the test light supplied through one waveguide to the other. 1. A fault location isolater for an optical transmission line, characterized in that it is comprised of a filter for propagating light to an optical waveguide. (4) The fault location isolator described in item (1) above,
It has third and fourth waveguides that respectively intersect with the first and second waveguides connected to the downlink and uplink core wires, and the test light is reflected at each of the intersections, and the communication light is A total reflection plate is installed at the intersection of the third and fourth waveguides, and the test light is inserted from the first waveguide of the down cable, reflected by the filter, and a total reflection plate is installed at the intersection of the third and fourth waveguides. It is inserted into the third waveguide, reflected by the total reflection plate, and inserted into the fourth waveguide.
A failure point cutoff in an optical transmission line characterized in that the optical transmission line is configured to be reflected again by a filter, inserted into a second waveguide, propagated to an upstream fiber, and propagated along a path opposite to the above. Divider.