JP5315269B2 - Optical equipment judgment system and judgment method - Google Patents

Description

  The present invention relates to an optical equipment determination system and a determination method under an optical splitter in a PON type optical access network constructed with optical fibers.

  With the recent expansion of Internet users and the spread of broadband applications such as videophone and video distribution, the use of communication networks using optical fibers is progressing. In particular, a PON (Passive Optical Network) type optical access network is widely used because it can be constructed economically at a relatively low cost.

In a general optical access network, an OLT (Optical Line Terminal) is installed at a base (central office) of a communication carrier, and the OLT is connected to an outdoor optical fiber via an optical termination in the central office.
In particular, in a PON type optical access network, an outdoor optical fiber is connected to an optical splitter on a power pole or the like, and an optical signal is branched by the optical splitter and transmitted to an ONU (Optical Network Unit) in a subscriber's house. The management and maintenance work of such optical equipment of an optical access network is usually performed by a telecommunications carrier.

  When centrally monitoring PON type optical access network equipment from the central office, GE-PON (Gigabit Ether-Passive Optical Network) monitoring technology, OTDR (Optical Time Domain Reflectometer) (optical pulse tester), etc. The optical pulse testing technique by is used.

  According to the GE-PON monitoring technology, a fault notification and link monitoring between the OLT and the ONU can be performed by a control function using an OAM frame defined in IEEE 802.3ah which is a GE-PON standard (non-patent document). Reference 1). For this reason, it is possible to grasp the communication state of the ONU to be tested. However, with this technique, it is difficult to specify the failure location when there is a disconnection of an optical fiber or the like.

  As a technique for monitoring an optical access network using an optical pulse test, an optical line test system incorporating functions of an OTDR and a power meter has been proposed (see Non-Patent Document 2). According to this technique, it is possible to confirm a failure position such as a disconnection generated on the optical fiber. However, in this optical pulse test, an optical pulse is sent from the central office to the subscriber's house, so if a failure occurs in the optical line below the optical splitter (subscriber's house side), A plurality of reflected lights are superimposed, and it is difficult to specify a fault location and monitor a communication state.

  In addition, for a PON type optical access network, there has also been proposed a method for estimating a network failure section by combining a GE-PON monitoring technique and an optical pulse test technique (see Non-Patent Document 3). However, with this method, it is difficult to specify the position of the optical filter below the optical splitter and measure the line length.

NTT Technology Journal September 2005 pp91-94 "GE-PON Technology" Fumi Izumida, IEICE Technical Report Vol.105, No.428, pp.55-60, 2005 “Trends in Standardization of Maintenance and Monitoring Technology for Optical Access Systems” Proceedings of the 2009 IEICE General Conference B-10-32 "Efficient optical line failure section estimation system using Ops cooperation"

  As described above, it is difficult to monitor and maintain the equipment below the optical splitter. For example, in order to determine the quality of optical equipment based on the OTDR waveform, equipment data such as optical fiber length is required, but in order to construct and operate a highly accurate optical fiber length equipment database. As the number of subscribers increases, it is necessary to keep facility data up-to-date, resulting in very high operational costs. For this reason, it is not easy to associate a plurality of reflected lights appearing on the OTDR waveform with the optical filter installed in the immediate vicinity of the ONU in a one-to-one relationship.

  Furthermore, when actually repairing a failure or the like, it is necessary to contrast from the cores of a plurality of optical fibers below the optical splitter. For example, in the optical line test system described in Non-Patent Document 3, for example, the comparison is performed using the core line control light, but it is difficult to easily identify the MAC address of the ONU connected to the core line.

  The present invention has been made in view of the above problems, and provides an optical equipment determination system and an optical equipment determination method capable of accurately acquiring optical line length data and determining an optical equipment in association with an identifier. With the goal.

The optical equipment determination system according to the present invention has the following configuration.
(1) An optical subscriber line terminal device installed at a telecommunications carrier base, connected to the optical subscriber line terminal device through an optical line, and receives an optical signal from the optical subscriber line terminal device. An optical splitter to be branched, and a plurality of subscriber line terminators connected to the optical splitter via an optical line and an optical filter, receiving optical signals branched by the optical splitter, and each having a unique identifier An optical equipment determination system used in an optical access network comprising: an optical subscriber based on a response delay time between the optical subscriber line terminal device and each of the plurality of subscriber line terminators. A first optical line length calculating means for calculating an optical line length between the line terminal device and each of the plurality of subscriber line terminal devices; and an optical pulse test to execute the optical subscriber line terminal device. And the plurality Second optical line length calculating means for calculating the optical line length between the optical filters connected to each of the subscriber line termination devices, the optical line length calculated by the first optical line length calculating means, Collating means for collating the optical line length calculated by the second optical line length calculating means, and based on the collation result by the collating means, the optical subscriber line terminal station device and the plurality of subscriber line terminating devices respectively And the optical line length between the optical subscriber line terminal unit and the optical filter connected to each of the plurality of subscriber line terminators. It is set as the aspect which comprises the matching means matched with an identifier.
According to this aspect, by comparing the optical line length obtained from the response delay time measurement with the optical line length obtained in the optical pulse test, the optical subscriber line terminal station device and the subscriber line termination device Between the optical line length, the position of the optical filter, and the identifier of the subscriber line terminator.

(2) In the configuration of (1), an aspect further includes a determination unit that determines a facility state of the subscriber line termination device based on a verification result by the verification unit.
According to this aspect, the equipment state of the subscriber line terminating device can be determined based on the collation result.

(3) In the configuration of (2), the determination means determines at least one of a power source of the subscriber line termination device, whether there is a failure, whether an optical filter is connected, and a distance from the optical filter. Let it be an aspect.
According to this aspect, as the equipment state of the subscriber line terminating device, it is possible to determine the state of the power supply, the presence or absence of a failure, whether the optical filter is connected, the distance from the optical filter, and the like.

(4) In the configuration of (3), the determination means includes a first number representing the number of subscriber line termination devices whose optical line length is calculated by the first optical line length calculation means, and the second When the first number is smaller than the second number, at least 1 is compared with the second number representing the number of subscriber line terminators whose optical line length is calculated by the optical line length calculating means. If it is determined that one of the subscriber line terminators is in a power-off state or a faulty state and the first number is greater than the second number, an optical filter is attached to at least one of the subscriber line terminators. The first number and the second number coincide with each other, and the first optical line length calculating means sets the optical line length to the optical line length by the second optical line length calculating means. If there is a difference, at least one subscriber line terminator is Is determined to be provided remotely, the first number matches the second number, and the first optical line length calculating unit calculates the optical line length and the second optical line length calculating unit. If there is no difference in the optical line length, the equipment state of the plurality of subscriber line terminators is determined to be normal.
According to this aspect, the equipment state of the subscriber line termination device can be determined according to the number of subscriber line termination devices whose optical line length can be calculated.

(5) In the configuration of (1), the second optical line length calculation means executes the optical pulse test a plurality of times to measure a physical quantity of reflected light, and obtains the result of the plurality of optical pulse tests. It further comprises an output means for detecting a change in the measurement result of the measured physical quantity and outputting an identifier of the subscriber line terminating device corresponding to the change.
According to this aspect, it is possible to accurately perform the optical line contrast operation.

(6) In the configuration of (1), the optical line length between the optical subscriber line terminal device and each of the plurality of subscriber line terminators is stored together with an identifier associated with the association means. An embodiment further includes a database.
According to this aspect, the state of the subscriber line terminating device can be easily updated.

The optical equipment determination method according to the present invention has the following configuration.
(7) An optical subscriber line terminal device installed at a telecommunications carrier base, and the optical subscriber line terminal device connected to the optical subscriber line terminal device via an optical line, and receiving an optical signal from the optical subscriber line terminal device An optical splitter to be branched, and a plurality of subscriber line terminators connected to the optical splitter via an optical line and an optical filter, receiving optical signals branched by the optical splitter, and each having a unique identifier An optical equipment determination method used in an optical access network comprising: an optical subscriber based on a response delay time between the optical subscriber line terminal device and each of the plurality of subscriber line terminators. A first optical line length calculating step for calculating an optical line length between the line terminal device and each of the plurality of subscriber line terminal devices; and an optical pulse test to execute the optical subscriber line terminal device. And the plurality A second optical line length calculating step for calculating an optical line length between the optical filters connected to each of the subscriber line terminating devices, an optical line length calculated by the first optical line length calculating step, A collating step for collating the optical line length calculated by the second optical line length calculating step, and based on a collation result by the collating step, the optical subscriber line terminal device and the plurality of subscriber line terminations The optical line length between each of the devices, and the optical line length between the optical subscriber line terminal device and the optical filter connected to each of the plurality of subscriber line terminators, respectively. It is set as the aspect provided with the matching step matched with the identifier of an apparatus.
According to this aspect, by comparing the optical line length obtained from the response delay time measurement with the optical line length obtained in the optical pulse test, the optical subscriber line terminal station device and the subscriber line termination device Between the optical line length, the position of the optical filter, and the identifier of the subscriber line terminator.

(8) In the configuration of (7), a determination step of determining the equipment state of the subscriber line termination device based on the comparison result is further provided.
According to this aspect, the equipment state of the subscriber line terminating device can be determined based on the collation result.
(9) In the configuration of (8), at least one of the power source of the subscriber line termination device, the presence / absence of a failure, the presence / absence of an optical filter connection, and the distance to the optical filter is determined.
According to this aspect, as the equipment state of the subscriber line terminating device, it is possible to determine the state of the power supply, the presence or absence of a failure, whether the optical filter is connected, the distance from the optical filter, and the like.

  According to the present invention, it is possible to provide an optical equipment determination system and an optical equipment determination method capable of accurately acquiring optical line length data and determining optical equipment in association with an identifier.

The figure which shows an example of a structure of the optical equipment determination system which concerns on one Embodiment of this invention. The figure which shows the data flow between a functional block of an OLT control terminal, an optical pulse test control terminal, and a core line determination apparatus, and a functional block. The flowchart which shows the procedure of the MAC address mapping process to reflected waveform data by an optical equipment determination system. The flowchart which shows the detail of the difference calculation process (step S31 of FIG. 3) of the distance between ONUs. The figure which shows an example of the list | wrist of the character string showing the MAC address and RTT value of each ONU which OLT acquired. The figure which shows the specific example of the data table which stored the calculation result data by the flowchart of FIG. The flowchart which shows the detail of the difference calculation process (step S32 of FIG. 3) of the distance between optical filters. The figure which shows an example of an optical pulse waveform. The figure which shows the specific example of the data table which stored the calculation result data by the flowchart of FIG. The flowchart which shows the detail of the collation process (step S33 of FIG. 3) of ONU. The figure which shows an example of the correspondence table of a MAC address and a peak point. The example which displayed the MAC address of ONU linked | related about each peak point on the optical pulse waveform shown in FIG. The figure which shows the structure of the optical equipment determination system required for an optical line length data update process. The figure which shows an example of the data table transmitted to an equipment database. The figure which shows the data flow between the functional blocks of an OLT control terminal, an optical pulse test control terminal, and a core line determination apparatus required for the determination process of the equipment state below an optical splitter. The flowchart of the determination process of the equipment state performed in an optical equipment determination system. The figure which shows an example of the corresponding | compatible table produced | generated when the number of ONUs whose optical line length was measured is smaller than the number of optical filters whose optical line length was measured. The figure which shows an example of the corresponding | compatible table produced | generated when the number of the optical filters whose optical line length was measured is smaller than the number of ONUs whose optical line length was measured. An example of a correspondence table generated when the number of ONUs in which the optical line length is measured and the number of optical filters in which the optical line length is measured match, but there is data in which the optical line length difference does not match FIG. The figure which shows the data flow between the functional blocks of an OLT control terminal, an optical pulse test control terminal, and a cardiac-wire determination apparatus required for a cardiac-wire contrast operation | work. The flowchart which shows the procedure of the core line contrast operation | work performed in an optical equipment determination system. The figure which shows an example of the correspondence table of MAC address of ONU and a peak point. The figure which shows the example of a corresponding | compatible table when the measurement result of the physical quantity of the 1st time and the 2nd time corresponds. The figure which shows the example of a corresponding | compatible table when the measurement result of the physical quantity of the 1st time and the 2nd time does not correspond. The figure which shows an example of the display of the point and MAC address with which the physical quantity changed. The figure which shows the work image of a core wire object process.

Embodiments of an optical equipment determination system according to the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram illustrating an example of the configuration of an optical equipment determination system according to an embodiment of the present invention. As shown in FIG. 1, this optical equipment determination system can be applied to a PON type optical access network.

  The OLT 11 is an optical subscriber line terminal equipment installed in a central office. The subscriber premises are equipped with subscriber line termination units (ONU) 20-1 to 20-8. A unique MAC address is assigned to each of the ONU 20-1 to ONU 20-8. In the example shown in FIG. 1, eight ONUs (ONUs 20-1 to 20-8) are shown, but the number of ONUs (that is, the number of subscriber homes) is not limited to this.

In the immediate vicinity of the ONUs 20-1 to 20-8, optical filters 22-1 to 22-8 having characteristics that block in-service test light and are confirmed as sufficient reflection points in the optical pulse test are installed, respectively. ing.
Each of the ONUs 20-1 to 20-8 and the OLT 11 are connected by an optical fiber. An off-site optical splitter S for combining and distributing optical signals is provided on the optical fiber path, and a plurality of ONUs 20-1 to 20-8 are connected to one OLT 11.

Between the OLT 11 and the outside light splitter S, an inside light splitter 12 and an optical branching coupler 13 are further connected.
An OLT control terminal 40 for controlling the operation of the OLT 11 based on the GE-PON system is connected to the OLT 11. The OLT control terminal 40 may be a normal computer device, for example.

  The optical pulse test apparatus 30 is an apparatus for an OTDR test in which an optical pulse is incident on an optical fiber and backscattered light is measured. Test light emitted from the optical pulse test apparatus 30 is inserted into the optical fiber by the optical coupler 13. Based on the measured backscattered light, the reflection point in the fiber can be detected. The optical pulse test apparatus 30 is connected to the optical pulse test control terminal 50, and the OTDR test by the optical pulse test apparatus 30 is controlled by the optical pulse test control terminal 50. The optical pulse test control terminal 50 may be a normal computer device, for example.

The OLT control terminal 40 and the optical pulse test control terminal 50 are connected to the core wire determination device 60 via a wired or wireless network N such as a LAN.
FIG. 2 is a diagram illustrating a data flow between the functional blocks of the OLT control terminal 40, the optical pulse test control terminal 50, and the core wire determination device 60.

  The OLT control terminal 40 includes a communication function unit 41 and an OLT control unit 42. The communication function unit 41 functions as an interface for communicating with the optical pulse test control terminal 50 and the core wire determination device 60 via the network N. The OLT control unit 42 is connected to the OLT 11 and controls the test of the OLT 11 using the GE-PON technology.

  The optical pulse test control terminal 50 includes a communication function unit 51 and an optical pulse test device control unit 52. The communication function unit 51 functions as an interface for communicating with the OLT control terminal 40 and the core wire determination device 60 via the network N. The optical pulse test control unit 52 is connected to the optical pulse test apparatus 30 and performs control such as test execution of the optical pulse test apparatus 30.

The core wire determination device 60 includes a communication function unit 61, a flow control unit 62, and a data storage unit 63. The communication function unit 61 functions as an interface for communicating with the OLT control terminal 40 and the optical pulse test control terminal 50 via the network N.
The flow control unit 62 includes, for example, a processor, a program memory, and a work memory. The processor executes a predetermined program stored in the program memory, thereby realizing the processing shown in the flowchart of FIG.

The data storage unit 63 includes a storage device such as a hard disk device or a flash memory, and stores data calculated by the processing of FIG.
<MAC address mapping to reflected waveform data>
FIG. 3 is a flowchart showing the procedure of the MAC address mapping process to the reflected waveform data by the optical equipment determination system configured as described above.

In this address mapping process, the difference between the ONUs is calculated (step S31), the difference between the optical filters is calculated (step S32), and the reflection point (peak point) on the optical pulse waveform is compared with the ONU. Association (step S33) is performed.
FIG. 4 is a flowchart showing details of the distance difference calculation process between ONUs (step S31 in FIG. 3).

  First, the core line determination device 60 requests the OTL control terminal 40 to acquire the RTT (Round Trip Time) of the ONUs 20-1 to 20-8 connected to the OLT 11 (step S41). In response to this, the OLT control terminal 40 requests the OLT 11 to acquire the RTT values of the ONUs 20-1 to 20-8 (step S42). The value of RTT represents the round trip delay time required for the confirmation response to return after sending the data frame.

The OLT 11 acquires a character string representing the MAC address and RTT value of each ONU, and sends it back to the OLT control terminal 40 (step S43).
FIG. 5 is a diagram illustrating an example of a list 500 of character strings representing the MAC address and RTT value of each ONU acquired by the OLT 11. The list 500 shows an example in which character strings are acquired from eight ONUs (ONU 20-1 to ONU 20-8) (“number of ONU = 8” in the list 500). Corresponding to each ONU, each character string includes an ONL LLID (Logical Link ID), an RTT value, and a MAC address. The LLID is an identifier assigned to each ONU. In this embodiment, it is assumed that the LLID of the ONU 20-1 is "001", the LLID of the ONU 20-2 is "002", ..., and the LLID of the ONU 20-8 is "008". In the example shown in FIG. 5, the RTT value is displayed in hexadecimal by a multiple (counter) of 16 ns, which is the minimum unit defined by the GE-PON system.

  Thereafter, a character string corresponding to each ONU is sent from the OLT control terminal 40 to the core wire determination device 60 (step S44). The core determination device 60 selects the minimum value from the received RTT values of each ONU, calculates the difference value between the minimum value and the RTT value of the other ONU, and calculates the optical line length difference between the ONUs (step S45). ). The optical line length difference between the ONU that gives the minimum RTT value and other ONUs is obtained from {(RTT difference value) × (speed of light in the optical fiber)} / 2.

The calculated optical line length difference of each ONU and the character string of the MAC address are stored in the data storage unit 63. Since the minimum separation accuracy of the RTT is 16 ns, the resolution of the optical line length difference is about 1.5 m considering the speed of light in the optical fiber.
FIG. 6 is a diagram showing a specific example of a data table storing calculation result data according to the flowchart of FIG. A data table 600 as shown in FIG. 6 is stored in the data storage unit 63.

In the table 600, the ONU 20-1 with the MAC address “xx-xx-xx-f9” having the minimum RTT value is selected as the reference, and the optical line length difference with the ONU 20-1 is selected for the other ONUs. Are stored in the table 600.
FIG. 7 is a flowchart showing details of the distance difference calculation processing between the optical filters (step S32 in FIG. 3).

  First, an execution instruction for the optical pulse test for the optical fiber cable connected to the OLT 11 is sent from the core determination device 60 to the optical pulse test control terminal 50 (step S71). In response to this, the optical pulse test control terminal 50 controls the optical pulse test apparatus 30 to execute an optical pulse test on the optical fiber cable connected to the OLT 11 (step S72). The optical pulse test apparatus 30 acquires the optical pulse waveform that is reflected back from each optical filter and transmits it to the optical pulse test control terminal 50.

  FIG. 8 is a diagram illustrating an example of the obtained optical pulse waveform. In this figure, the horizontal axis indicates the optical line length, and the vertical axis indicates the signal light intensity. As shown in FIG. 8, peak points (peak points) A to H of the signal light intensity occur corresponding to the optical splitter and the optical filters 22-1 to 22-2.

When such an optical pulse waveform is measured by the optical pulse test control terminal 50, the optical pulse test control terminal 50 transmits the optical pulse waveform data to the core wire determination device 60 (step S73).
The core wire determination device 60 detects a peak point (reflection point) representing the optical filter from the peak value of the optical pulse waveform based on the preset reflection reference value of each optical filter, and corresponds to the peak point. The optical line length to be calculated is calculated (step S74).

The core wire determination device 60 selects a minimum value from the detected line length to the optical filter, and calculates a difference value between the minimum value and the line length to another optical filter (step S75).
Each detected filter point and the corresponding line length difference value are stored in the data storage unit 63.

FIG. 9 is a diagram showing a specific example of a data table storing calculation result data according to the flowchart of FIG. A data table 900 as shown in FIG. 9 is stored in the data storage unit 63.
In the table 900, the optical line lengths up to the respective peak points are stored corresponding to the peak points A, B,... Among these, the peak point A having the minimum optical line length (2000) is selected as a reference, and the difference in the optical line length from the peak point A is stored in the table 900 for the other peak points. .

FIG. 10 is a flowchart showing details of the ONU matching process (step S33 in FIG. 3).
First, the flow control unit 62 of the core wire determination device 60 reads data obtained by the above-described processes from the data storage unit 63 (step S101). That is, the flow control unit 62 determines the number of ONUs connected to the OLT 11 obtained by the process of FIG. 4, the corresponding MAC address, the difference in the optical line length between the ONUs, and each of the processes obtained by the process of FIG. 7. The filter point (peak point) and the difference in the optical line length between the peak points are read from the data storage unit 63.

Then, the flow control unit 62 compares and collates each data, and determines whether or not the optical line length differences match (step S102).
The flow control unit 62 extracts data that matches the difference in optical line length, and creates a correspondence table between filter points and MAC addresses (step S103).

  FIG. 11 is a diagram illustrating an example of a correspondence table between MAC addresses and peak points. In the correspondence table 1100 shown in FIG. 11, the ONU of the MAC address “xx-xx-xx-f9” and the peak point A correspond to each other. Also, since the difference “12” in the optical line length corresponding to the ONU with the MAC address “xx-xx-xx-f8” matches the difference “12” in the optical line length corresponding to the peak point B, both data are the same. It is associated. Similarly, with respect to the MAC addresses of other ONUs, peak points at which optical line length differences are matched are associated.

Furthermore, the flow control unit 62 associates the MAC address of the corresponding ONU with the peak point on the optical pulse waveform obtained as a result of the optical pulse test (step S104).
FIG. 12 shows an example in which the MAC address of the ONU associated with each peak point is displayed on the optical pulse waveform shown in FIG. As shown in FIG. 12, the peak point A is associated with the MAC address of the ONU 20-1, and the peak point B is associated with the MAC address of the ONU 20-2. Similarly, the corresponding ONU MAC addresses are also associated with other peak points.

However, execution of the process of step S104 may not be essential.
<Optical line length data update>
Then, the update process of the optical line length data by the optical equipment determination system which concerns on this embodiment is demonstrated with reference to drawings. In the following description, parts corresponding to those in the above description of MAC address mapping are denoted by corresponding reference numerals, and detailed description thereof is omitted.

  FIG. 13 is a diagram illustrating a configuration of an optical equipment determination system required for optical line length data update processing. In this configuration, in addition to the configuration shown in FIG. 1, an equipment database 601 and a database reference client terminal 603 are provided. The facility database 601 and the database reference client 6 terminal 03 may be connected to the network N.

The facility database 601 is a database that stores data transmitted from the core wire determination device 60. The database reference client terminal 603 is used for referring to data stored in the facility database 601.
Necessary data is transmitted to the equipment database 601 and stored from the correspondence table (for example, the data table 1100 shown in FIG. 11) between the MAC address and the peak point generated by the MAC address mapping described above.

  FIG. 14 is a diagram illustrating an example of a data table transmitted to the facility database 601. As shown in the data table 1400 illustrated in FIG. 14, the MAC address of each ONU, the corresponding optical line length (obtained as a result of the optical pulse test) are stored in the equipment database 601 from the data storage unit 63 of the core determination device 60. And the optical line length from the optical splitter S (lower length of the optical splitter) are sent.

Data sent to the facility database 601 can be output by the database reference client terminal 603 being read out and displayed on the display screen.
Data transmission from the core wire determination device 60 to the facility database 601 may be performed in accordance with an operation of the core wire determination device 60 by an operator, or may be automatically performed at predetermined time intervals.

Each piece of data updated as described above can be used in the determination of the equipment state below the outside light splitter and the core contrast work described below.
<Determination of equipment status under the outside light splitter>
Next, an equipment state determination process below the optical splitter S by the optical equipment determination system according to the present embodiment will be described with reference to the drawings. In the following description, portions corresponding to those described above are denoted by corresponding reference numerals, and detailed description thereof is omitted.

FIG. 15 shows the flow of data between functional blocks of the OLT control terminal 40, the optical pulse test control terminal 50, and the core wire determination device 60 required for the equipment state determination process below the optical splitter S. FIG.
In FIG. 15, in addition to the functional block diagram shown in FIG. 3, the core wire determination device 60 includes an equipment determination unit 64.

The equipment determination unit 64 determines the equipment state below the optical splitter S based on the results of the distance difference calculation process between the ONUs (step S31) and the distance difference calculation process between the optical filters (step S32). Determine.
FIG. 16 is a flowchart of an equipment state determination process executed in the optical equipment determination system configured as described above.

  Similar to step S101 shown in FIG. 10, the flow control unit 62 of the core wire determination device 60 performs a distance difference calculation process between ONUs (FIG. 4) and a distance difference calculation process between optical filters (FIG. 7). The data obtained by the above is read from the data storage unit 63 (step S161). That is, the flow control unit 62 determines the number of ONUs connected to the OLT 11 obtained by the process of FIG. 4, the corresponding MAC address, the difference in the optical line length between the ONUs, and each peak obtained by the process of FIG. The point and the difference in the optical line length between the points are read from the data storage unit 63.

Then, similarly to step S102 of FIG. 10, the flow control unit 62 compares and collates each data, and determines whether or not the optical line length differences match (step S162).
As in step S103 of FIG. 10, the flow control unit 62 extracts data having the same optical line length difference, and creates a correspondence table of filter points and MAC addresses (step S163).

Next, the flow control unit 62 determines whether or not a peak point having the same optical line length difference is obtained for all ONUs as a result of collation of each data (step S164).
When the peak points with the same optical line length difference are obtained for all ONUs (Yes in step S164), each peak point extracted from the optical pulse waveform is associated with the ONU MAC address in a one-to-one relationship. Then, it is determined that there is no abnormality in the ONUs 20-1 to 20-8 and the optical filters 22-1 to 22-8 (step S165).

In this case, as shown in the correspondence table 1100 in FIG. 11, corresponding peak points can be detected for the MAC addresses of all ONUs.
On the other hand, when the number of ONUs whose optical line length is measured is smaller than the number of optical filters whose optical line length is measured, a correspondence table 1700 as shown in FIG. 17 is generated in step S163. In the correspondence table 1700 of FIG. 17, the MAC address data of the ONU corresponding to the peak point H is not obtained. In this case, it is determined that there is no abnormality in the optical fiber cable below the optical splitter S, but there is an ONU that has failed or is not turned on (step S166).

  If the number of optical filters whose optical line length is measured is smaller than the number of ONUs whose optical line length is measured, a correspondence table 1800 as shown in FIG. 18 is generated in step S163. In the correspondence table 1800 of FIG. 18, an optical filter corresponding to the ONU 20-8 whose MAC address is “xx-xx-xx-ac” is not detected. In this case, it is determined that there is an optical fiber cable to which no optical filter is connected below the optical splitter S (step S167).

  Further, when there are data in which the number of ONUs in which the optical line length is measured and the number of optical filters in which the optical line length is measured are the same, but the difference in the optical line length is not consistent, as shown in FIG. A correspondence table 1900 has been generated in step S163. In the correspondence table 1600 of FIG. 19, the optical line length difference of the ONU 20-8 whose MAC address is “xx-xx-xx-ac” is “100”, and the optical line length difference at the peak point H is “115”. And they do not match. In such a case, it is determined that there is a difference in the distance between the optical filter and the ONU line (step S168).

In particular, since the minimum resolution of the optical line difference calculated based on the RTT value is 1.5 m, if the mismatch of the optical line length difference is 1.5 m or more, the length of the mismatch between the optical filter and the ONU It is determined that there is an optical fiber corresponding to this.
<Application to core contrast work>
Next, an example in which the optical equipment determination system according to the present embodiment is applied to a core line contrast operation will be described with reference to the drawings. In the following description, portions corresponding to those described above are denoted by corresponding reference numerals, and detailed description thereof is omitted.

FIG. 20 is a diagram illustrating a data flow between the functional blocks of the OLT control terminal 40, the optical pulse test control terminal 50, and the cardiac determination device 60 required for the cardiac control work.
In FIG. 20, in addition to the functional block diagram shown in FIG. 3, the core wire determination device 60 includes a measured value comparison unit 65. FIG. 26 is a diagram illustrating a specific work image for contrasting the core wires. In the following description, it is assumed that the operator PO in the central office and the outdoor worker PS at the lower part of the outdoor light splitter S proceed with work while communicating with a mobile phone or the like.

FIG. 21 is a flowchart showing the procedure of the core line contrast work performed in the optical equipment determination system configured as described above.
First, in response to an instruction from the operator PO, the core line determination device 60 creates a correspondence table between the MAC address of each ONU and the filter point (peak point) in the optical pulse waveform (step S211). The correspondence table is created in the same procedure as the MAC address mapping shown in FIG. However, in the optical pulse test (steps S72 to S73 in FIG. 7), a physical quantity (for example, reflection peak intensity) relating to each optical filter point is measured.

  FIG. 22 is a diagram illustrating an example of a correspondence table between ONU MAC addresses and peak points. In the correspondence table 2200 shown in FIG. 22, the ONU of the MAC address “xx-xx-xx-f9” and the peak point A correspond to each other. Further, since the optical line length difference “12” of the ONU with the MAC address “xx-xx-xx-f8” and the optical line length difference “12” at the peak point B match, both data are associated with each other. Similarly, peak points at which optical line length differences are matched are also associated with the MAC addresses of other ONUs. Furthermore, in the correspondence table 2200, the measured reflection peak intensity (filter peak value) is associated with each peak point.

Next, for example, an outdoor worker PS bends the core of a specific optical fiber below the optical splitter S, thereby changing the peak intensity of the reflected waveform (step S212).
Subsequently, the same processing as in step S211 is repeated, and again, the core line determination device 60 creates a correspondence table between the MAC address of each ONU and the filter point in the optical pulse waveform (step S213).

  In the core wire determination device 60, the measurement value comparison unit 65 compares the physical quantity (reflection peak intensity) measured in step S211 with the physical quantity (reflection peak intensity) obtained in step S213, and the measurement result in step S211. And whether or not the measurement results in step S213 match (step S214).

  If all the physical quantity measurement results match (Yes in step S214), the correspondence table 2301 created in step S211 and the correspondence table 2302 created in step S213 match as shown in FIG. For this reason, it is determined that there is no change between the first measurement (step S211) and the second measurement (step S213) (step S215). In this case, as shown in FIG. 23, the first and second reflection peak intensities (optical filter peak values) are the same for all ONUs (or optical filters).

  On the other hand, if there is a discrepancy in the measurement results (No in step S214), as shown in FIG. 24, an optical filter is created between the correspondence table 2401 created in step S211 and the correspondence table 2402 created in step S213. There is a discrepancy in peak values. In the example shown in FIG. 24, the physical quantity measurement result changes at the peak point H.

In this case, the peak point where the physical quantity has changed and the MAC address of the corresponding ONU are displayed, for example, on the display screen of the core wire determination device 60 (step S216).
FIG. 25 is a diagram illustrating an example of display of points and MAC addresses where the physical quantity has changed. In this example, the peak point “H” corresponding to the MAC address “xx-xx-xx-ac” of the ONU in which the physical quantity change has occurred is shown on the display of the optical pulse waveform.

As described above, based on the position of the optical filter where the change in the physical quantity is detected and the MAC address of the ONU, the outdoor worker PS is connected to the ONU of the subscriber whose corresponding core wire is to work in the field. It becomes possible to confirm that it is a fiber core wire.
As described above, in this core line contrast operation, the operator PO operates the core line determination device 60 to measure physical quantities such as the reflection peak intensity of each optical filter below the optical splitter (first time). Next, the outdoor worker PS bends one of the optical fibers below the optical splitter, and in this state, the operator PO operates the lower core wire determination 60 to perform the second measurement.

  The core wire determination device 60 can display the ONUs under the optical fiber to which the bend is applied, and the worker PS can compare the ONUs connected to the optical fiber core wire to which the bend is applied. The measurement value comparison unit 65 compares the first and second measurement results, and detects the MAC address of the ONU that has changed and the corresponding optical filter point. The detection result can be displayed on the display screen of the core wire determination device 60.

As for the method of changing the peak value of the optical pulse waveform, not only bending the core wire at the bottom of the optical splitter as described above, but also polarization modulation by applying side pressure to the optical fiber may be used. . Alternatively, the peak value may be changed by other methods.
As described above, according to the core line determination device according to the present embodiment, the MAC address mapping process shown in FIG. 3 allows one-to-one correspondence between the MAC address of each ONU and the reflection point by the optical filter. It becomes. This eliminates the need for an equipment database that holds detailed information about equipment, and even if an optical filter is added, an update operation for manually inputting the optical filter data into the equipment database is also unnecessary. In addition, by acquiring the result of the optical pulse test and the RTT information acquired by the OLT 11 in real time, the reflection point of the latest optical filter can be associated with the MAC address of the ONU.

  The maximum length of the optical line is expressed on the order of several kilometers, whereas the measurement accuracy of the line length obtained from the RTT information is about 1.5 m. For this reason, the position of the optical filter can be specified with high accuracy. Furthermore, when measuring the position of the optical filter from the reflection waveform obtained as a result of the optical pulse test, even if the reflection peak value is superimposed because the line length of the plurality of optical filters is the same, the RTT Since collation with the optical line length obtained based on this is performed, it is easy to estimate the position of the optical filter.

  In addition, according to the above-described embodiment, since the position of the optical filter can be specified only by existing optical equipment such as an optical filter and an OLT, no additional equipment investment is required. Therefore, it is excellent also in terms of economy. In addition, it does not require measurement from the subscriber's home side, and can be realized only by a test from the central office side, and it is not necessary to increase the number of field workers.

  Moreover, the line length from the optical pulse test apparatus 30 to each ONU and the line length from the optical splitter S to each ONU are automatically updated and stored in the equipment database by the update process of the optical line length data. Since these data are line length data measured by the optical pulse tester 30, the line length measurement accuracy is extremely high. In addition, since it is a system that does not involve human input for data entry into the database, there is no error due to human error, and an accurate track length database can be constructed. In addition, it is possible to update data in real time, and it is possible to refer to an equipment database without a time lag.

Furthermore, in the process of determining the equipment state below the off-site optical splitter S, it is possible to confirm whether the optical filter is connected to each ONU and confirm the normality of the optical line. Further, at the time of determination, the position of the optical filter can be confirmed even if there is an ONU that is not in a communication state or an ONU that is not turned on. Therefore, an abnormality in the optical line section below the optical splitter S can be confirmed. By determining whether or not an optical filter is installed, it is possible to evaluate the normality of the optical filter installation. In addition, in the work subject to the core in the optical equipment determination system according to the present embodiment, a physical quantity (for example, peak intensity) is measured. It is performed a plurality of times (for example, twice). The ONU MAC corresponding to the peak point of the optical filter connected to the optical line subjected to the artificial state change based on the result of the measurement after artificially changing the state of the optical line during the measurement. An address is detected. Therefore, it is possible for the operator to confirm in the field whether or not the optical line to which the state change has been applied is an optical fiber core wire connected to the ONU of the subscriber to be worked on.

  In the optical equipment determination system according to the present embodiment, an RTT that represents a round-trip time of a frame between an OLT that is a transmission apparatus in a PON type network and an ONU installed in a subscriber's house is measured, and from the OLT to the ONU Calculate the optical line length. On the other hand, an optical pulse test is performed, and the position of the optical filter provided in the immediate vicinity of the ONU and the length of the optical line to the optical filter are measured based on the reflected waveform from the optical filter. By comparing the optical line length obtained by the RTT measurement with the optical line length obtained by the optical pulse test, the MAC address of the ONU corresponding to the position of the optical filter is determined, and each is associated and stored. Can do.

Furthermore, the data regarding the optical line length obtained as described above can be easily and accurately registered in the database system.
Further, the state of the optical equipment below the optical splitter (such as the presence or absence of a failure) can be determined based on the data verification result.

  In addition, an artificial change is applied to the optical line, and the change in the physical quantity such as the peak value of the reflected waveform from the optical filter is measured. The optical line in which the artificial change is applied from the peak point where the change is detected. The optical filter connected to, the position of the optical filter, and the MAC address of the corresponding ONU can be acquired. For this reason, the contrast operation | work of the optical fiber below an optical splitter can be advanced easily.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the invention at the stage of implementation. Further, each of the embodiments includes inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements shown in one embodiment or the constituent elements shown in some embodiments are combined, they are described in the column of the problem to be solved by the invention. In the case where the problems described above can be solved and the effects described in the “Effects of the Invention” can be obtained, a configuration in which these constituent requirements are deleted or combined can be extracted as an invention.

  DESCRIPTION OF SYMBOLS 11 ... OLT, 12 ... In-house optical splitter, 13 ... Optical coupler, 20-1-20-8 ... ONU, 22-1-22-8 ... Optical filter, 30 ... Optical pulse test apparatus, 40 ... OLT control terminal, 50 ... Optical pulse test control terminal, 60 ... Core wire determination device, N ... Network, S ... Outside light splitter.

Claims (9)

An optical subscriber line terminal device installed at a telecommunications carrier base, and an optical device that is connected to the optical subscriber line terminal device via an optical line and branches an optical signal from the optical subscriber line terminal device A splitter, and a plurality of subscriber line terminators connected to the optical splitter via optical lines and optical filters, receiving optical signals branched by the optical splitter, and assigned with unique identifiers, respectively. An optical equipment determination system used in an optical access network,
Based on a response delay time between the optical subscriber line terminal device and each of the plurality of subscriber line terminators, between the optical subscriber line terminal device and each of the plurality of subscriber line terminators. First optical line length calculating means for calculating the optical line length of
Second optical line length calculation means for performing an optical pulse test and calculating an optical line length between the optical subscriber line terminal station device and an optical filter connected to each of the plurality of subscriber line termination devices When,
Collating means for collating the optical line length calculated by the first optical line length calculating means with the optical line length calculated by the second optical line length calculating means;
Based on the verification result by the verification means, the optical line length between the optical subscriber line terminal device and each of the plurality of subscriber line termination devices, and the optical subscriber line terminal device and the plurality of subscriptions An association means for associating the optical line length between the optical filters connected to each of the subscriber line termination devices with the identifier of each subscriber line termination device;
An optical equipment determination system comprising:   The optical equipment determination system according to claim 1, further comprising determination means for determining an equipment state of the subscriber line termination device based on a result of collation by the collation means.   The optical equipment determination system according to claim 2, wherein the determination means determines at least one of a power source of the subscriber line termination device, whether there is a failure, whether an optical filter is connected, and a distance from the optical filter. . The determination means includes
A first number representing the number of subscriber line terminators whose optical line length has been calculated by the first optical line length calculating means; and a subscription whose optical line length has been calculated by the second optical line length calculating means. Compare with a second number representing the number of line termination devices,
If the first number is less than the second number, it is determined that at least one subscriber line termination device is in a power-down state or a failure state;
If the first number is greater than the second number, it is determined that an optical filter is not attached to at least one subscriber line termination device;
When the first number matches the second number, and there is a difference between the optical line length by the first optical line length calculation unit and the optical line length by the second optical line length calculation unit Determining that at least one subscriber line terminator is remote from the optical filter;
When the first number matches the second number, and there is no difference between the optical line length by the first optical line length calculation means and the optical line length by the second optical line length calculation means The optical equipment determination system according to claim 3, wherein the equipment status of the plurality of subscriber line termination devices is determined to be normal. The second optical line length calculation means measures the physical quantity of reflected light by executing the optical pulse test a plurality of times,
2. The apparatus according to claim 1, further comprising an output unit that detects a change in the measurement result of the physical quantity obtained as a result of the plurality of optical pulse tests and outputs an identifier of the subscriber line termination apparatus corresponding to the change. Optical equipment judgment system.   2. The database according to claim 1, further comprising a database that stores an optical line length between the optical subscriber line terminal device and each of the plurality of subscriber line termination devices together with an identifier associated with the association unit. Optical equipment judgment system. An optical subscriber line terminal device installed at a telecommunications carrier base, and an optical device that is connected to the optical subscriber line terminal device via an optical line and branches an optical signal from the optical subscriber line terminal device A splitter, and a plurality of subscriber line terminators connected to the optical splitter via optical lines and optical filters, receiving optical signals branched by the optical splitter, and assigned with unique identifiers, respectively. An optical equipment determination method used in an optical access network,
Based on a response delay time between the optical subscriber line terminal device and each of the plurality of subscriber line terminators, between the optical subscriber line terminal device and each of the plurality of subscriber line terminators. A first optical line length calculating step of calculating the optical line length of
A second optical line length calculating step of calculating an optical line length between the optical subscriber line terminal station device and an optical filter connected to each of the plurality of subscriber line terminal devices by executing an optical pulse test; When,
A collating step of collating the optical line length calculated by the first optical line length calculating step with the optical line length calculated by the second optical line length calculating step;
Based on the verification result in the verification step, an optical line length between the optical subscriber line terminal device and each of the plurality of subscriber line termination devices, and the optical subscriber line terminal device and the plurality of subscriptions An associating step of associating an optical line length between the optical filter connected to each of the subscriber line terminating devices with an identifier of each subscriber line terminating device;
An optical equipment determination method comprising:   The optical equipment determination method according to claim 7, further comprising a determination step of determining an equipment state of the subscriber line termination device based on the collation result.   The optical equipment determination method according to claim 8, wherein at least one of a power source of the subscriber line termination device, a presence / absence of a failure, a connection / non-connection of an optical filter, and a distance from the optical filter is determined.

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