JP5167321B2 - Optical communication system and connection state determination method - Google Patents

Description

  The present invention relates to an optical communication system in which an ONU (Optical Network Unit) and an OLT (Optical Line Terminal) are connected by an optical fiber for communication, and a connection state determination method of the optical communication system, and more particularly to switching at the time of optical cable route switching work. The present invention relates to an optical communication system and a connection state determination method for performing optical time domain reflectometry (OTDR) measurement that evaluates connection points and a core contrast that specifies a communication optical fiber.

  In recent years, with the increase in optical access services and the expansion of the optical service area, the amount of optical facilities has increased, and the obstruction relocation work for changing the optical cable route has also increased along with road construction and the like. At the same time, there has been an increase in housing replacement work for changing the optical cable route in the communication equipment building.

  In obstacle relocation work or accommodation replacement work, after laying the switching destination optical cable, identify the communication optical fiber that is the switching source, cut the communication optical fiber, and switch the core to connect to the switching destination communication optical fiber An operation is performed, and a test is performed as to whether the connection is correctly made after the connection operation (see, for example, Non-Patent Documents 1 to 3).

  In order to identify the communication optical fiber that is the switching source during the core switching operation, the communication optical fiber from the communication equipment building is modulated on the longer wavelength side (for example, 1650 nm band) than the communication wavelength ( For example, if the communication optical fiber is bent to the extent that it does not affect communication at the outdoor switching point using the bending portion of the receiving section of the core wire contrast device, the modulation is performed from the communication optical fiber. Since light leaks, it is possible to identify the corresponding optical fiber for communication by determining the presence or absence of leaked light at the light receiving unit of the receiving unit.

  In addition, when performing a connection test at a connection point after connection work at an outdoor switching point, an optical measurement device called OTDR is used to output pulse light from a communication equipment building to measure connection loss and return loss at the connection point. Then, the normality confirmation terminal 18 confirms that each measured value is within the standard value and is correctly connected.

The following describes the work procedures for both the obstacle relocation work and the housing replacement work.
First, the work procedure at the time of obstacle relocation work will be described with reference to FIG. Communication is performed between the OLT 92 and the ONU 91. Further, the communication facility building 90 and optical coupler 11 is installed, or removed communication light _{L C,} pulsed light _{L P} and cord control for the light source from OTDR13-2 (LS: Light Source) 13-1 or you can insert the modulated light L _M from. Further, the communication optical fiber 94 at the trouble transfer destination is laid in advance between the work site A and the work site B.

When performing trouble transferring construction, first, it sends a modulated light L _M by core control light source 13-1 from communication facility building 90 to the communication optical fiber 93 of the switching target. Bend the communication optical fiber 93 be switched from the communication facility building 90 at the work site B is distant, in the relevant communication optical fiber 93 by receiving the leaking light of the modulated light L _M in ID tester (receiving unit) After specifying that there is, the communication optical fiber 93 is cut. At the same time, it is confirmed from the communication equipment building 90 that the communication optical fiber 93 has been cut using the OTDR for the communication optical fiber 93 to be switched.

Next, it sends the modulated light L _M by core control light source 13-1 from communication facility building 90 to the communication optical fiber 93 of the switching target. In the work site A, as in the work site B, the communication optical fiber 93 to be switched is bent, and the leaked light is received by the ID tester (reception unit). Then, the communication optical fiber 93 is cut. At the same time, the communication optical fiber 93 has been disconnected from the communication equipment building 90 using the OTDR 13-2 from the communication equipment building 90 to the communication optical fiber 93 to be switched, as in the confirmation work previously performed at the work site B. Confirm.

  Next, connection work with the communication optical fiber 94 of the obstacle relocation destination is performed at each of the work site A and the work site B. After the connection work is completed, the OTDR 13 is connected from the communication equipment building 90 to the communication optical fiber 94 to be switched. -2 is used to measure the connection loss and return loss at the connection point of the corresponding communication optical fiber 94, and confirm that each measurement value is within the standard value and is correctly connected.

Next, the work procedure for the housing replacement work will be described with reference to FIG. The workers are arranged in the communication facility building 90 and the work site A, respectively. Communication is performed between the OLT 92 and the ONU 91. Further, the communication facility building 90 and the optical coupler 11 is installed, or removed communication light _{L C,} the modulated light _{L M} from the pulse light _{L P} and cord control for the light source 13-1 from OTDR13-2 Can be inserted. Further, the communication optical fiber 93N as the accommodation replacement destination is laid in advance between the OLT 92N and the work site A.

When that accommodates replacement construction, first, it sends a modulated light L _M by core control light source 13-1 from communication facility building 90 to the communication optical fiber 93 of the switching target. Bend the communication optical fiber 93 be switched at the work site A, after identifying whether the corresponding communication optical fiber 93 by receiving the leaking light of the modulated light L _M in ID tester (receiving unit), the appropriate communication light The fiber 93 is cut. At the same time, it is confirmed from the communication equipment building 90 that the communication optical fiber 93 is cut using the OTDR 13-2 for the communication optical fiber 93 to be switched.

  Next, switching is performed with the accommodation-replacement destination communication optical fiber 93N at the work site A, and after the connection is completed, the communication equipment building 90 uses the OTDR 13-2 for the communication optical fiber 93N to be switched, and the corresponding communication light. Measure the connection loss and return loss at the connection point of the fiber, and confirm that each measured value is within the standard value and is connected correctly.

Masahito Arii, Yuji Higashi, Tomotaka Enomoto, Katsaki Suzuki, Noriyuki Araki, Shigenori Uruno, Tsuneichi Watanabe, “Optical Media Network Operation Technology that Supports Expanding Optical Access Networks”, NTT Technology Journal, pp. 11-27. 58-61, 2006.12 Suzuki Katsuaki, Yamamoto Motoshi, Natsume Arata, “Optical Fiber Contrast Technology for R15 Core”, NTT Technical Journal, pp. 54-55, 2007.4 Kaoru Sasamura, Satoshi Awazu, Yukihiro Fujimoto, Hiroki Kataoka, “FTTH section communication monitoring technology to realize mid-call confirmation in switching work such as trouble relocation”, NTT Technical Journal, pp. 40-42, 2009.5

  When carrying out optical cable switching work in troubled relocation work, etc., specify the optical fiber to be switched by contrast control, disconnect the target optical fiber, confirm the disconnection by OTDR measurement, connect to the destination optical fiber, by OTDR measurement The work procedure is to check the connection to the destination optical fiber.

  At the time of relocation, the optical fiber for communication in the work procedure and the connection to the optical fiber for communication at the relocation destination are arranged at work site A and work site B with 4 or 8 optical fibers lined up. The four or eight optical fibers for communication having the optical fiber tape structure are cut and connected together. An example of a fiber of a four-core optical fiber tape is shown in FIG.

  Here, in the optical fiber tape, the first core wire and the fourth core wire or the eighth core wire are colored so that they can be identified. However, the work site for cutting and connecting is mainly in the manhole, and since the work environment is underground, it is difficult to identify because the work environment is dark. May end up.

  Even if it is connected by mistake, the optical fiber length from the communication equipment building 90 to the connection point is almost the same length as the first core wire and the fourth core wire or the eighth core wire. Even in the connection test using -2, it could not be determined that the connection was incorrect.

On the other hand, it receives signals from ONU91 installed in the user's home, has a function of displaying the MAC address, and monitor the uplink signal frame placed on the communication light _{L C} from ONU91, each ONU91 There is a device (hereinafter referred to as “monitor device”) having a function of determining the link establishment status between the Internet and the OLT 92 and the usage status of the Internet or Hikari Telephone in units of ONUs 91 (see, for example, Non-Patent Document 3).

  By using the monitor device, it is possible to check the service usage status of the user, so it is possible to avoid accidentally disconnecting the service being communicated by the user during the switching work. When performing, it is necessary to replace the connected OTDR 13-2 or LS 13-1 and a terminal for confirming normality.

  Further, the connection of the monitor device to the optical coupler 11 is an MT connector connection, and when connecting the monitor device, it is necessary to connect with an MT connector for each switching target core wire, and there are a plurality of switching target core wires. In this case, the connection work of the MT connector occurs every switching work, which is very complicated.

  Therefore, the present invention can perform an optical fiber communication system and a communication monitor at the same time as well as an OTDR measurement and a communication monitor at the same time, and does not need to change the connection of the measuring device according to a work procedure and a connection state determination method. The purpose is to provide.

  To achieve the above object, an optical communication system according to the present invention is an optical communication system in which an OLT (Optical Line Terminal) and an ONU (Optical Network Unit) are connected by a single optical fiber for communication. Of the communication optical fiber, the light that is disposed near the OLT and propagates through the communication optical fiber is branched to the measurement optical fiber, and the light from the measurement optical fiber is split into the communication light. An optical coupler coupled to a fiber; an OTDR connected to the measurement optical fiber, which outputs pulsed light toward the ONU and measures the light intensity of the return light from the communication optical fiber; and the measurement Connected to the optical fiber for measurement and connected to the optical fiber for measurement and the optical fiber for measurement, which outputs modulated light toward the ONU. It is, obtains the identifier from the ONU that is connected, and a monitoring device for collating the identifier stored in advance and the acquired identifier.

  Since the OTDR, the core-line contrast light source, and the monitor device are connected to the common optical fiber for measurement, the core-line contrast and the communication monitor can be performed simultaneously and the OTDR measurement and the communication monitor can be performed simultaneously. Furthermore, since the OTDR and the core wire reference light source are connected to a common optical fiber for measurement, it is not necessary to change the connection of the measuring device according to the work procedure. Therefore, the present invention can provide an optical communication system that can simultaneously perform the contrast control and the communication monitor and simultaneously perform the OTDR measurement and the communication monitor, and does not need to change the connection of the measuring device according to the work procedure. it can.

In the optical communication system of the present invention, the optical communication system includes a plurality of sets of the OLT and the ONU connected by the communication optical fiber, and the optical coupler is provided in each of the communication optical fibers. The light propagated by the communication optical fiber is branched to the different measurement optical fibers, and any one of the measurement optical fibers, the OTDR, the core wire reference light source, and the monitor An optical fiber switching optical switch for measurement that can be connected to the apparatus may be provided.
Since the measurement optical fiber switching optical switch connected to the plurality of communication optical fibers is provided, the test of the plurality of communication optical fibers can be performed using a common OTDR, a core wire reference light source, and a monitor device.

The optical communication system of the present invention may further include a monitoring optical coupler for branching the light propagated through the measurement optical fiber to the OTDR, the core-line reference light source, and the monitoring device.
Since the wavelengths of the pulsed light, the modulated light, and the communication light are different, the loss reduction due to the insertion of the coupler can be prevented by using the monitoring optical coupler.

  In order to achieve the above object, the connection state determination method of the present invention is a measurement method in which an OLT and an ONU are connected by a single optical fiber for communication and branched from an optical coupler inserted in the optical fiber for communication. A method for determining a connection state of an optical communication system in which an optical fiber is connected to an optical fiber reference light source and an OTDR, wherein a monitor device connected to the measurement optical fiber acquires an identifier from the ONU A collation between an identifier and a pre-stored identifier, and the optical fiber reference light source, wherein the optical fiber reference light source outputs modulated light toward the ONU; and the optical coupler of the optical fiber for communication The path change procedure for cutting the ONU side optical fiber to connect to the new communication optical fiber with a different path, and the monitor device acquires the identifier from the ONU. OTDR measurement in which the acquired identifier is collated with a previously stored identifier, and the OTDR outputs a pulsed light toward the ONU to measure the light intensity of the return light from the communication optical fiber. And in order.

  Since the OTDR, the core line contrast light source, and the monitor device are connected to a common optical fiber for measurement, the core line contrast and the communication monitor can be performed simultaneously in the core line contrast light output procedure, and the OTDR in the OTDR measurement procedure. Measurement and communication monitoring can be performed simultaneously. Furthermore, since the OTDR and the core line reference light source are connected to a common optical fiber for measurement, it is not necessary to change the connection between the core line reference light output procedure and the OTDR measurement procedure. Therefore, the invention of the present application can simultaneously perform the contrast control and the communication monitor, and simultaneously perform the OTDR measurement and the communication monitor, and does not need to change the connection of the measuring device according to the work procedure. Can be provided.

  In order to achieve the above object, the connection state determination method of the present invention is a measurement method in which an OLT and an ONU are connected by a single optical fiber for communication and branched from an optical coupler inserted in the optical fiber for communication. A method for determining a connection state of an optical communication system in which a core-line reference light source and an OTDR are connected to an optical fiber of the optical fiber, wherein a monitor device connected to the measurement optical fiber acquires an identifier from the ONU And comparing the identifier stored in advance with the identifier stored in advance, and the optical fiber for the optical fiber for communication, and the optical fiber for communication, in which the optical fiber for contrast control outputs modulated light toward the ONU An OLT changing procedure for cutting an optical fiber on the ONU side from a coupler and connecting to a new communication optical fiber connected to a new OLT different from the OLT, and the new The monitor device connected to the optical fiber for measurement branched from the optical coupler inserted in the trusted optical fiber acquires the identifier from the ONU, and collates the acquired identifier with the identifier stored in advance. The OTDR connected to the measurement optical fiber branched from the optical coupler inserted into the new communication optical fiber outputs pulse light toward the ONU and returns from the communication optical fiber. An OTDR measurement procedure for measuring the light intensity of light in order.

  Since it has a core-line contrast light output procedure, an OLT change procedure, and an OTDR measurement procedure, it can be determined whether or not the communication optical fiber different from the desired communication optical fiber is connected in the OLT change procedure. it can. Here, since the OTDR, the core line contrast light source, and the monitor device are connected to the common optical fiber for measurement, the core line contrast and the communication monitor can be simultaneously performed in the core line contrast light output procedure, and the OTDR measurement is performed. In the procedure, OTDR measurement and communication monitoring can be performed simultaneously. Thereby, this invention can provide the connection state determination method of the optical communication system which does not need to change connection of a measuring device according to a work procedure.

In the connection state determination method of the present invention, the optical communication system includes a plurality of sets of the OLT and the ONU connected by the communication optical fiber, and each of the optical couplers provided in each of the communication optical fibers. Branching to a different measurement optical fiber, connecting the measurement optical fiber to the measurement optical fiber switching optical switch, and switching the measurement optical fiber switching optical switch, the measurement optical fiber You may further have the core line selection procedure which selects either of them before the said core wire contrast light output procedure.
Since the core selection procedure is provided, a plurality of communication optical fibers can be tested using a common OTDR, a core reference light source, and a monitor device.

  The above inventions can be combined as much as possible.

  According to the present invention, an optical communication system and a connection state determination method that can simultaneously perform the contrast control and the communication monitor and simultaneously perform the OTDR measurement and the communication monitor, and do not need to change the connection of the measuring device according to the work procedure. Can be provided.

1 is an example of an optical communication system according to a first embodiment. It is an example of the optical communication system which concerns on Embodiment 1 in a core line contrast light output procedure. It is a 1st example of a state of the optical communication system which concerns on Embodiment 1 in a connection change procedure. It is a 2nd example of a state of the optical communication system which concerns on Embodiment 1 in a connection change procedure. It is a 3rd example of a state of the optical communication system which concerns on Embodiment 1 in a connection change procedure. It is a 4th state example of the optical communication system which concerns on Embodiment 1 in a connection change procedure. It is an example of the optical communication system which concerns on Embodiment 1 in an OTDR measurement procedure. An example of the optical communication system which concerns on Embodiment 2 is shown. An example of the optical communication system which concerns on Embodiment 3 is shown. It is an example of the optical communication system which concerns on Embodiment 3 in a core line contrast light output procedure. It is a 1st example of a state of the optical communication system which concerns on Embodiment 3 in an OLT change procedure. It is a 2nd state example of the optical communication system which concerns on Embodiment 3 in an OLT change procedure. An example of the optical communication system which concerns on Embodiment 4 is shown. 10 illustrates an example of an optical communication system according to a fifth embodiment. The work procedure at the time of conventional obstacle relocation work is shown. The work procedure at the time of conventional accommodation replacement work is shown. 2 shows an example of an optical communication system in which an erroneous connection has occurred.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components.

(Embodiment 1)
The optical communication system according to the present embodiment will be specifically described with reference to FIGS. The optical communication system and the connection state determination method according to the present embodiment will be described with reference to an embodiment in trouble relocation work.

  The optical communication system according to the present embodiment includes an ONU 91, an OLT 92, a communication optical fiber 93, an optical coupler 11, a measurement optical fiber 12, an optical measuring device 13, and a monitor device 14. This is an optical communication system in which an OLT 92 and an ONU 91 are connected by a single optical fiber 93 for communication. The OLT 92 and the ONU 91 are connected by a single optical fiber 93 for communication. The optical coupler 11 is disposed in the vicinity of the OLT 92 of the communication optical fiber 93 and branches the light propagated through the communication optical fiber 93 to the measurement optical fiber 12, and from the measurement optical fiber 12. The light is multiplexed into the communication optical fiber 93. The communication optical fiber 94 at the obstacle transfer destination is laid between the work site A and the work site B in advance.

The optical measuring device 13 is connected to the measurement optical fiber 12 and functions as OTDR and LS. Optical measuring unit 13, when functioning as OTDR measures the light intensity of the return light from the pulse light L _P to output the communication optical fiber 93 toward the ONU91. Optical measuring unit 13, when functioning as a core control light source outputs modulated light P _M toward the ONU91. Wavelength of communication light _{L C,} for example, the uplink signal is 1490 nm, the downlink signal is 1310 nm. In this case, the wavelength of the modulated light _{L M} and the pulse light _{L P,} for example, to use a maintenance wavelength 1650 nm.

As shown in FIG. 1, the workers are arranged in the communication facility building 90, the work site A, and the work site B, respectively. Communication is performed between the OLT 92 and the ONU 91. Further, the optical coupler 11 is installed in the communication facility building 90, the optical fiber 12 for measurement, which is connected to the optical coupler 11, and retrieve the communication light L _C, pulsed light L _P and the modulated light P _M Or other test light can be inserted.

  A monitoring optical coupler 15 is further installed in the measurement optical fiber 12. The monitoring optical coupler 15 branches the light propagated through the measurement optical fiber 12 into an optical measuring device 13 and a monitoring device 14. An optical measuring device 13 is connected to one of the branching optical couplers 15 for monitoring, and a monitoring device 14 is connected to the other branching of the optical coupler 15 for monitoring. The monitor device 14 is connected to the measurement optical fiber 12, acquires an identifier from the connected ONU 91, and collates the acquired identifier with a pre-stored identifier. The identifier of the ONU 91 is a MAC address, for example. Here, it is preferable that the monitoring optical coupler 15 has a wavelength dependency, and the 1310 nm band is transmitted through the monitor device 14 and the 1650 nm band is transmitted through the optical measuring device 13. Thereby, loss reduction due to insertion of the coupler can be prevented.

  The connection state determination method of the optical communication system according to the present embodiment includes a core-line contrast light output procedure, a connection change procedure, and an OTDR measurement procedure in this order. When performing the obstacle relocation work, the monitor device 14 acquires the identifier of the corresponding ONU 91 in advance and confirms the usage status.

In the optical fiber reference light output procedure, the monitor device 14 connected to the measurement optical fiber 12 acquires an identifier from the ONU 91 and collates the acquired identifier with a previously stored identifier. Also, core control light source provided in the optical measuring unit 13 outputs the modulated light _{L M} toward the ONU91. For example, as shown in FIG. 2, initially, it emits modulated light L _M from the communication facility building 90. From communication facility building 90 by bending the communication optical fiber 93 at the work site B is distant, to identify whether the specified communication optical fiber 93 by receiving the leaking light of the modulated light L _M in ID tester (receiving unit) .

In the connection change procedure, the communication optical fiber 93 closer to the ONU 91 than the optical coupler 11 in the communication optical fiber 93 is cut and connected to a new communication optical fiber 94 having a different path. For example, the communication optical fiber 93 is cut as shown in FIG. Then, the monitor device 14 displays that communication has been interrupted. Next, as shown in FIG. 4, for emitting the modulated light L _M from the communication facility building 90. Bend the communication optical fiber 93 in the same manner at the work site A, after identifying the modulated light L _M corresponding communication optical fiber 93 by receiving the ID tester leakage light (receiver) of, as shown in FIG. 5, The communication optical fiber 93 is cut. Next, as shown in FIG. 6, the work site A and the work site B are connected to the communication optical fiber 94 at the trouble transfer destination.

In the OTDR measurement procedure, the monitor device 14 acquires an identifier from the ONU 91 and collates the acquired identifier with a previously stored identifier. Furthermore, OTDR provided in the optical measuring unit 13 measures the light intensity of the return light from the pulse light L _P outputs to optical communication fiber 93 and the communication optical fiber 94 toward the ONU91. For example, when the connection is completed, the identifier and usage status of the ONU 91 are displayed on the monitor device 14 of the communication facility building 90 as shown in FIG. Further, the optical measuring unit 13 outputs a pulse light L _P, the connection loss and return loss at the connection point between the communication optical fiber 93 and the communication optical fiber 94 to determine whether the kept within the specified values.

  Here, as shown in FIG. 17, when the tape is connected in reverse, the monitor device 14 acquires an identifier of another ONU 91. For this reason, it turns out that the monitor apparatus 14 is not connected correctly. At this time, the monitor device 14 may display that the identifier of the ONU 91 is different, or may not display the identifier of the ONU 91.

(Embodiment 2)
FIG. 8 shows an example of an optical communication system according to the present embodiment. The optical communication system according to the present embodiment includes a plurality of sets of OLT 92-i and ONU 91-i connected by a communication optical fiber 93-i, and these sets include a common optical measuring device 13 and monitor device 14. Prepare. For this purpose, the optical communication system according to the present embodiment includes an optical switch 21, a controller 22, and an operation terminal 23. In FIG. 8, for the sake of simplicity, one of a set of OLT 92-i and ONU 91-i connected by a plurality of communication optical fibers 93-i is described as a representative.

  The optical coupler 11-i is provided in each of the communication optical fibers 93-i, and branches the light propagated through the communication optical fibers 93-i to different measurement optical fibers 12-i. Each measurement optical fiber 12-i is connected to the optical switch 21. The optical switch 21 can connect any optical fiber of the measurement optical fibers 12-i to the optical measuring device 13 and the monitor device. As a result, by connecting the monitoring optical coupler 15 between the optical switch 21 and the optical measuring device 13 and connecting it to the monitoring device 14, the switching work can be performed as in the first embodiment.

The controller 22 controls the optical switch 21 and the optical measuring device 13. The operation terminal 23 operates the controller 22. For example, when the operator inputs the identification number k of the communication optical fiber 93-i to the operation terminal 23, the controller 22 causes the k-th of the plurality of measurement optical fibers 12-i and the measurement optical fiber 12. Is output to the optical switch 21. Then, the optical switch 21 connects the measurement optical fiber 12-k and the measurement optical fiber 12. On the other hand, when the operator selects OTDR of OTDR or LS for the operation terminal 23, the controller 22 outputs a command for performing OTDR measurement to the optical measuring device 13. Then, the optical measuring unit 13 outputs a pulse light _{L P.} As described above, when the operator selects a core wire from the operation terminal 23 and performs the test, the optical switch 21 automatically connects the corresponding core wire, and emits the modulated light and performs the measurement by OTDR. Can do.

  In the case of the present embodiment, since the optical switch 21 is used for selecting the test core wire, the switching operation of a plurality of core wires can be performed very simply. Since the operation terminal 23 does not have to be placed in the communication equipment building 90, the trouble relocation work can be easily performed from outside the communication equipment building 90.

(Embodiment 3)
The optical communication system according to the present embodiment will be specifically described with reference to FIGS. The optical communication system and the connection state determination method according to the present embodiment will be described with reference to an embodiment in the housing replacement work.

As shown in FIG. 9, the workers are arranged in the communication facility building 90 and the work site A, respectively. Communication is performed between the OLT 92 and the ONU 91. Further, the optical coupler 11 is connected to the communication facility building 90, the optical fiber 12 for measurement, which is connected to the optical coupler 11, and retrieve the communication light L _C, pulsed light L _P and the modulated light P _M Or other test light can be inserted.

  A monitor optical coupler 15 is further installed at one end of the measurement optical fiber 12. The monitoring optical coupler 15 branches the light propagated through the measurement optical fiber 12 into an optical measuring device 13 and a monitoring device 14. An optical measuring device 13 is connected to one of the branching optical couplers 15 for monitoring, and a monitoring device 14 is connected to the other branching of the optical coupler 15 for monitoring.

  In addition, the communication optical fiber 93N as the accommodation replacement destination is preliminarily laid between the OLT 92N as the accommodation replacement destination and the work site A, and in the communication facility building 90, similarly to the communication optical fiber 93 performing the communication. Is provided with an optical coupler 11N. Further, a monitoring optical coupler 15N is provided at one end of the optical coupler 11N. An optical measuring device 13N is provided at one end of the monitoring optical coupler 15N, and a monitoring device is provided at the other end. 14N is connected.

  The connection state determination method of the optical communication system according to the present embodiment includes a core-line contrast light output procedure, an OLT change procedure, and an OTDR measurement procedure in this order. When the accommodation replacement work is performed, the identifier of the corresponding ONU 91 is acquired in advance by the monitor device 14 and the monitor device 14N, and the usage status is confirmed.

In the optical fiber reference light output procedure, the monitor device 14 connected to the measurement optical fiber 12 acquires an identifier from the ONU 91 and collates the acquired identifier with a previously stored identifier. Also, core control light source provided in the optical measuring unit 13 outputs the modulated light _{L M} toward the ONU91. For example, as shown in FIG. 10, first, it emits modulated light L _M from the communication facility building 90. Work site bending the communication optical fiber 93 A, to identify whether the specified communication optical fiber 93 by receiving the leaking light of the modulated light L _M in ID tester (receiving unit).

  In the OLT change procedure, the communication optical fiber 93 closer to the ONU 91 than the optical coupler 11 in the communication optical fiber 93 is disconnected, and a new communication optical fiber 93N connected to a new OLT 92N different from the OLT 92 Connecting. For example, the communication optical fiber 93 is cut as shown in FIG. Then, it is displayed on the monitor device 14 that the communication is cut off. Next, as shown in FIG. 12, the work site A connects to the accommodation changing destination communication optical fiber 93N.

In the OTDR measurement procedure, the monitor device 14N connected to the measurement optical fiber 12N branched from the optical coupler 11N inserted into the new communication optical fiber 93N acquires the identifier from the ONU 91, and the acquired identifier and Collate with an identifier stored in advance. Also, OTDR optical measurement device 13N, which is connected to the optical fiber 12N for measurement which is branched from the inserted to a new communication optical fiber 93N optical coupler 11N may output the pulse light _{L P} toward the ONU91 Then, the optical intensity of the return light from the communication optical fiber 93N and the communication optical fiber 93 is measured. For example, when the connection between the communication optical fiber 93N and the communication optical fiber 93 is completed, the identifier of the ONU 91 and the usage status are displayed on the monitor device 14N of the communication facility building 90. Further, the optical measuring device 13N outputs a pulse light L _P, the connection loss and return loss at the connection point between the communication optical fiber 93 and the communication optical fiber 93N determines whether the kept within the specified values.

(Embodiment 4)
FIG. 13 shows an example of an optical communication system according to the present embodiment. The optical communication system according to this embodiment includes a plurality of sets of OLT 92-i and ONU 91-i connected by the communication optical fiber 93-i described in the second embodiment. For example, a set of OLT 92-i and ONU 91-i connected by communication optical fiber 93-i and a set of OLT 92-j and ONU 91-j connected by communication optical fiber 93-j are provided. . In FIG. 13, for simplicity, one of a set of OLT 92-i and ONU 91-i connected by a plurality of communication optical fibers 93-i is described as a representative. In addition, one of a set of OLT 92-j and ONU 91-j connected by a plurality of communication optical fibers 93-j is described as a representative.

  Then, accommodation replacement work is performed for one of the communication optical fibers 93-i to one of the communication optical fibers 93-j. At this time, these sets include a common optical measuring device 13 and a monitor device 14. For this purpose, the optical communication system according to the present embodiment includes optical switches 21-1 and 21-2, an optical switch 24, a controller 22, and an operation terminal 23.

When the operator selects one of the plurality of communication optical fibers 93-i and inputs it to the operation terminal 23, the optical switch 21-1 automatically connects the corresponding measurement optical fiber 12-i. . When the operator selects one of the connection cores from the plurality of communication optical fibers 93-j and inputs it to the operation terminal 23, the optical switch 21-2 automatically applies the corresponding measurement optical fiber. 12-j is connected. Then, the controller 22, the optical measuring unit 13 to output the modulated light _{L M} and the pulse light _{L P.} Thereby, the optical switch 21-1 and the optical switch 21-2 can automatically connect the corresponding core wires, and can perform emission of modulated light and measurement by OTDR.

A monitoring optical coupler 15 is connected between the optical switch 21-1 and the optical switch 21-2 and the optical measuring device 13, and the monitoring optical coupler 15 and the monitoring device 14 are connected. Therefore, measurement i.e. core control and OTDR measurements in emission and OTDR of the modulated light L _M can be carried out in the same manner as Embodiment 3.

  In the case of the present embodiment, since an optical switch is used for selecting the test core wire, even switching work by changing accommodation can be performed very easily without connecting two monitor devices. Since the operation terminal 23 does not have to be placed in the communication equipment building 90, the accommodation replacement work can be easily performed from outside the communication equipment building 90.

(Embodiment 5)
FIG. 14 shows an example of an optical communication system according to the present embodiment. In the optical communication system according to the present embodiment, the connection destination of the monitoring optical coupler 15 and the monitoring optical coupler 15N described in the third embodiment is the common monitoring device 14. In this way, by connecting the monitoring optical coupler 15N to the common monitoring device 14, it is possible to easily perform the operation without having to connect a plurality of monitoring devices 14.

  The present invention can be applied to the information communication industry.

11, 11N, 11-i, 11-j: Optical couplers 12, 12-i, 12-j, 12N: Measurement optical fiber 13, 13N: Optical measuring device 13-1: LS
13-2: OTDR
14, 14N: monitoring device 15, 15N: monitoring optical coupler 18: normality confirmation terminal 21, 21-1, 21-2: optical switch 22: controller 23: operation terminal 24: optical switch 18: normality confirmation terminal 90 : Communication equipment building 91, 91-i: ONU
92, 92N, 92-i, 92-j: OLT
93, 93N, 93-i, 93-j: optical fiber for communication 94: optical fiber for communication at the destination of trouble transfer

Claims (6)

An optical communication system in which an OLT (Optical Line Terminal) and an ONU (Optical Network Unit) are connected by a single optical fiber for communication,
Of the communication optical fiber, disposed near the OLT, the light propagating through the communication optical fiber is branched to the measurement optical fiber, and the light from the measurement optical fiber is used for the communication. An optical coupler for combining with an optical fiber;
OTDR (Optical Time Domain Reflectometer) that is connected to the measurement optical fiber, outputs pulsed light toward the ONU, and measures the light intensity of the return light from the communication optical fiber;
A core-contrast light source connected to the measurement optical fiber and outputting modulated light toward the ONU;
A monitor that is connected to the measurement optical fiber, acquires an identifier from the connected ONU, and collates the acquired identifier with a pre-stored identifier;
An optical communication system comprising: The optical communication system includes a plurality of sets of the OLT and the ONU connected by the communication optical fiber,
The optical coupler is provided in each of the communication optical fibers, and the light propagated through the communication optical fiber is branched into different optical fibers for measurement,
The optical fiber switching optical switch for measurement which can connect arbitrary optical fibers of the optical fibers for measurement with the OTDR, the core line contrast light source, and the monitor device is provided. Optical communication system. The light according to claim 1, further comprising: a monitoring optical coupler that branches light propagating through the measurement optical fiber to the OTDR, the core-line contrast light source, and the monitoring device. Communications system. Optical communication in which the OLT and ONU are connected by a single optical fiber for communication, and the optical fiber for measurement branched from the optical coupler inserted in the optical fiber for communication is connected to the optical fiber reference light source and the OTDR. A system connection state determination method,
The monitoring device connected to the measurement optical fiber acquires an identifier from the ONU, and collates the acquired identifier with a pre-stored identifier,
A cord contrast light output procedure in which the cord contrast light source outputs modulated light toward the ONU;
A path change procedure for cutting the optical fiber on the ONU side of the optical coupler of the communication optical fiber and connecting to the new communication optical fiber having a different path;
The monitor device acquires an identifier from the ONU, collates the acquired identifier with a previously stored identifier,
The OTDR outputs a pulsed light toward the ONU and measures the light intensity of the return light from the communication optical fiber; and
A method for determining a connection state of an optical communication system having, in order. Optical communication in which the OLT and ONU are connected by a single optical fiber for communication, and the optical fiber for measurement branched from the optical coupler inserted in the optical fiber for communication is connected to the optical fiber reference light source and the OTDR. A system connection state determination method,
The monitoring device connected to the measurement optical fiber acquires an identifier from the ONU, and collates the acquired identifier with a pre-stored identifier,
A cord contrast light output procedure in which the cord contrast light source outputs modulated light toward the ONU;
An OLT change procedure for cutting an optical fiber on the ONU side of the optical coupler of the communication optical fiber and connecting to a new communication optical fiber connected to a new OLT different from the OLT;
The monitor device connected to the measurement optical fiber branched from the optical coupler inserted into the new communication optical fiber acquires the identifier from the ONU, and the acquired identifier and the identifier stored in advance And matching
The OTDR connected to the measurement optical fiber branched from the optical coupler inserted into the new communication optical fiber outputs pulse light toward the ONU and returns from the communication optical fiber. OTDR measurement procedure for measuring the light intensity of
A method for determining a connection state of an optical communication system having, in order. The optical communication system includes a plurality of sets of the OLT and the ONU connected by the communication optical fiber,
An optical coupler provided in each of the communication optical fibers is branched into different measurement optical fibers, and the measurement optical fibers are connected to the measurement optical fiber switching optical switch, and the measurement optical fiber switching is performed. 6. The method according to claim 4, further comprising a core selection procedure for selecting any one of the measurement optical fibers by switching an optical switch before the core control light output procedure. Of determining the connection state of the optical communication system.

Images