Terminal device, communication method and program

Abstract

A terminal device according to an aspect of the present invention is in a passive optical communication network in which the terminal device and a subscriber line terminal device are connected to each other, said terminal device comprising: a distance measurement unit that measures the distance between the terminal device and the subscriber line terminal device; a signal strength measurement unit that measures the strength of a signal which has been received from the subscriber line terminal device; and an inference unit that infers the occurrence of a sign of a failure in the subscriber line terminal device on the basis of the result of measurement of the distance by the distance measurement unit and the result of measurement of the strength of the signal by the signal strength measurement unit.

Description

[Technical field]

[0001] The present invention relates to an end station device, a communication method, and a program. [Background technology]

[0002] In a passive optical network (PON) (see, for example, non-patent documents 1 and 2) in which a terminal device, which is an in-office communication device of a telecommunications line carrier (sometimes referred to as a line carrier), is connected to multiple subscriber line terminals, the subscriber line terminal is an in-home communication device installed in the home of a user who receives communication services from the telecommunications line carrier, and therefore the telecommunications line carrier cannot freely access this subscriber line terminal. On the other hand, when a failure or the like occurs in the subscriber line termination device, the line carrier is required to carry out a rapid recovery operation such as repairing or replacing the subscriber line termination device. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] NTT Access Network Service Systems Laboratories, "Technical Basics Lecture [GE-PON Technology] Part 2: IEEE802.3ah Standard," NTT Technical Review, September 2005, pp. 91-94. [Non-Patent Document 2] NTT Access Network Service Systems Laboratories, "Technical Basics Lecture [GE-PON Technology] Part 4: Systemization Functions of GE-PON," NTT Technical Journal, November 2005, pp. 59-61. Summary of the Invention [Problem to be solved by the invention]

[0004] On the other hand, currently, the terminal device detects a failure of the subscriber line termination device by detecting an abnormality in the connection status of the communication line (sometimes simply referred to as the line) between the terminal device and the subscriber line termination device, or by detecting a failure of the subscriber line termination device using the self-monitoring function of the subscriber line termination device and notifying the terminal device. Upon detection, the terminal device notifies the line carrier's management system of the failure of the subscriber line termination device, etc. Only after receiving this notification can the line carrier carry out the above-mentioned restoration work.

[0005] In this way, when the above-mentioned restoration work is performed after a failure or the like of the subscriber line termination device is detected, a period of time will be required during which the provision of communication services to users will be suspended until the restoration work is completed.

[0006] The present invention has been made in consideration of the above circumstances, and has as its object to provide a terminal device, a communication method, and a program that are capable of reducing the impact on communication services caused by a failure of a subscriber line termination device. [Means for solving the problem]

[0007] A terminal device according to one aspect of the present invention is a device in a passive optical communication network in which a terminal device and a subscriber line terminal are connected, and includes a distance measurement unit that measures a distance between the terminal device and the subscriber line terminal, a signal strength measurement unit that measures a strength of a signal received from the subscriber line terminal, and an estimation unit that estimates the occurrence of a precursor of a failure in the subscriber line terminal based on a result of the distance measurement by the distance measurement unit and a result of the signal strength measurement by the signal strength measurement unit. The estimation unit estimates the occurrence of a precursor of a failure in the subscriber line termination device when the distance measured by the distance measurement unit is a predetermined distance longer than a normal distance and the strength measured by the signal strength measurement unit is a predetermined strength stronger than a normal strength. . A terminal device according to one embodiment of the present invention is a device in a passive optical communication network in which a terminal device and a subscriber line terminal are connected, and comprises a distance measurement unit that measures the distance between the terminal device and the subscriber line terminal, a signal strength measurement unit that measures the strength of a signal received from the subscriber line terminal, and an estimation unit that estimates the occurrence of a precursor to a failure in the subscriber line terminal based on the distance measurement results by the distance measurement unit and the signal strength measurement results by the signal strength measurement unit, and the estimation unit estimates the occurrence of a precursor to a failure in the subscriber line terminal when the distance measured by the distance measurement unit is a predetermined length shorter than a normal distance and the strength measured by the signal strength measurement unit is a predetermined strength weaker than a normal strength.

[0008] A communication method according to one aspect of the present invention is performed by a terminal device in a passive optical communication network in which a terminal device and a subscriber line unit are connected to each other. circle A method for The distance measurement unit of the terminal device measuring a distance between the terminal device and the subscriber line termination device; The signal strength measurement unit of the terminal devicemeasuring the strength of a signal received from the subscriber line termination device; The estimation unit of the terminal device and estimating the occurrence of a precursor of a fault in the subscriber line termination device based on the distance measurement result and the signal strength measurement result. The step of estimating includes estimating the occurrence of a precursor of a fault in the subscriber line termination device when the measured distance is a predetermined distance longer than a normal distance and the measured strength is a predetermined strength stronger than a normal strength. . A communication method according to one embodiment of the present invention is a method performed by a terminal device in a passive optical communication network to which the terminal device and a subscriber line terminal device are connected, and includes the steps of: measuring the distance between the terminal device and the subscriber line terminal device using a distance measurement unit of the terminal device; measuring the strength of a signal received from the subscriber line terminal device using a signal strength measurement unit of the terminal device; and estimating, by an estimation unit of the terminal device, the occurrence of a precursor to a failure in the subscriber line terminal device based on the distance measurement results and the signal strength measurement results, wherein the estimation includes estimating the occurrence of a precursor to a failure in the subscriber line terminal device when the measured distance is a predetermined distance shorter than a normal distance and the measured strength is a predetermined strength weaker than a normal strength. Effect of the Invention

[0009] According to the present invention, it is possible to reduce the effect on communication services caused by a failure of a subscriber line termination device. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram showing an application example of a communication system according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a table showing an example of conditions for estimating deterioration of a subscriber line termination unit. [Diagram 3] FIG. 3 is a flow chart showing an example of a process for estimating deterioration of a subscriber line termination unit. [Figure 4] FIG. 4 is a block diagram showing an example of a hardware configuration of a terminal device in a communication system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an application example of a communication system according to an embodiment of the present invention. 1, a communication system according to an embodiment of the present invention includes an end station device 10 and a plurality of subscriber line terminals 20. The end station device 10 is an OLT (Optical Line Terminal) in a station of a line carrier, and the subscriber line terminals 20 are ONUs (Optical Network Units) in the premises of users who receive communication services provided by the line carrier.

[0012] The terminal device 10 and the subscriber line terminal 20 are communicatively connected to each other via a relay network 30, which is an optical communication network using an optical fiber cable and an optical splitter, to form a passive optical communication network. The optical fiber cable is also simply called an optical cable. The terminal device 10 is communicatively connected to a higher-level communication network 40 in the communication system. The terminal device 10 is communicatively connected to a management system 50 of a communication line carrier in the communication system via a monitoring and control network 60, which is a communication network for monitoring and control.

[0013] The terminal device 10 includes a maintenance function unit 11 , a communication processing unit 12 , and a storage unit 13 . The maintenance function unit 11 includes a distance measurement unit 11a and a deterioration estimation unit 11b. The distance measurement unit 11a outputs a control signal for measuring the cable length between the terminal device 10 and the subscriber line terminal 20, i.e., the distance which is the length of the optical cable, to each of the multiple subscriber line terminals 20 via the communication processing unit 12, and measures the distance of the communication path between the terminal device 10 and the subscriber line terminal 20 to which the control signal is sent, for each subscriber line terminal 20, based on the time required to send and receive this output control signal. The communication processing unit 12 has a signal strength measuring unit 12a. The signal strength measuring unit 12a measures the strength of the optical signals transmitted from the multiple subscriber line terminals 20, propagated through the optical fiber cable, and received by the terminal device 10 for each of the subscriber line terminals 20 that are the transmission sources.

[0014] Based on the distance measurement results by the distance measurement unit 11a and the optical signal strength measurement results by the signal strength measurement unit 12a, when these measurement results satisfy the conditions described below and are stored in the memory unit 13, the degradation estimation unit 11b estimates that degradation has occurred in the optical transmitting module (sometimes referred to as the transmitting module) of the subscriber line terminal 20 related to the measurement results, which is a precursor to a failure, etc., in other words, that there is a high possibility that the subscriber line terminal 20 will fail in the near future, and outputs a signal indicating the result of this estimation to the management system 50 via the monitoring and control network 60. This allows the communication line carrier to recognize that degradation has occurred in the transmission module of the subscriber line terminal 20, and to carry out maintenance work before the subscriber line terminal 20 breaks down.

[0015] In this embodiment, this degradation means that although communication between the terminal device 10 and the subscriber line termination device 20 is currently possible, there is a relatively high possibility that a malfunction or other problem will occur in the subscriber line termination device 20 in the future, which will cause communication between the terminal device 10 and the subscriber line termination device 20 to become impossible.

[0016] FIG. 2 is a table showing an example of conditions for estimating deterioration of a subscriber line termination unit. The storage unit 13 of the terminal device 10 stores information in a table format showing conditions for estimating the deterioration of the subscriber line termination device 20 as shown in FIG. The table shown in Figure 2 indicates, as a first condition, that when the distance (L in Figure 1), which is the cable length between the terminal device 10 and the subscriber line terminal 20, becomes equal to or exceeds a normal distance, for example, a predetermined distance longer than the distance when the cable is laid, and the strength of the optical signal transmitted from the subscriber line terminal 20 and received by the terminal device 10 becomes equal to or exceeds a normal strength, for example, a predetermined strength stronger than the strength of the optical signal when the subscriber line terminal 20 was installed, the degradation estimation unit 11b estimates that degradation has occurred in the transmitting module of the subscriber line terminal 20.

[0017] The above-mentioned predetermined distance that is longer than the normal distance is, for example, a distance that is approximately 0.01[%] longer than the normal distance. The above-mentioned predetermined intensity that is stronger than the normal intensity is, for example, an intensity that is about 1 [db] stronger than the normal intensity.

[0018] The length of the cable between the terminal device 10 and the subscriber line unit 20 may change due to, for example, deterioration of tension on the cable over time or an extended temperature cycle on the cable. Furthermore, the strength of the optical signal transmitted from the subscriber line terminal 20 and received by the terminal device 10 may vary due to, for example, abnormal operation of the transmission module of the subscriber line terminal 20 .

[0019] Furthermore, the table shown in Figure 2 indicates, as a second condition, that when the distance between the terminal device 10 and the subscriber line terminal 20 becomes equal to or less than a predetermined distance that is shorter than the normal distance, and the strength of the optical signal transmitted from the subscriber line terminal 20 and received by the terminal device 10 becomes equal to or less than a predetermined strength that is weaker than the normal strength, the degradation estimation unit 11b estimates that degradation has occurred in the transmitting module of the subscriber line terminal 20.

[0020] The above-mentioned predetermined distance that is shorter than the normal distance is, for example, a distance that is shorter than the normal distance by about 0.01%. The above-mentioned predetermined intensity that is weaker than the normal intensity is, for example, an intensity that is about 1 [db] weaker than the normal intensity.

[0021] When neither the first nor the second condition is satisfied, the degradation estimation unit 11b estimates that there is no degradation as a precursor to a failure or the like in the transmission module of the subscriber line termination device 20, or that there is a relatively low possibility that degradation has occurred. On the other hand, when the first or second condition is satisfied, the degradation estimation unit 11b estimates that there is a relatively high possibility that there is degradation as a precursor to a failure or the like in the transmission module of the subscriber line termination device 20.

[0022] The estimation using the above table is based on the relationship between the cable length between the terminal device 10 and the subscriber line unit 20 and the strength of the optical signal transmitted from the subscriber line unit 20 and received by the terminal device 10.

[0023] The strength of an optical signal transmitted through an optical fiber cable attenuates in proportion to the distance, which is the length of the cable. Furthermore, the output strength of the optical signal of the optical transmission module of the subscriber line terminal 20 changes due to aging or other reasons, and eventually goes into a failure state. In many cases, the output strength of this optical signal becomes weaker due to aging.

[0024] From the above, if the cable length is shortened while the strength of the optical signal is weakened, or if the cable length is lengthened while the strength of the optical signal is strengthened, it is considered that the transmitting module of the subscriber line terminal 20 is degraded or there is a relatively high possibility that such deterioration will occur, and there is a relatively high possibility that a failure or the like of the subscriber line terminal 20 will occur in the near future, as described above, which will cause communication between the terminal device 10 and the subscriber line terminal 20 to be impossible.

[0025] Therefore, in this embodiment, the deterioration estimation unit 11b compares the distance between the terminal device 10 and the subscriber line terminal 20 and the strength of the optical signal transmitted from the subscriber line terminal 20 and received by the terminal device 10 with the table shown in Figure 2, and estimates whether or not there is a possibility of deterioration of the transmitting module of the subscriber line terminal 20.

[0026] FIG. 3 is a flowchart illustrating an example of a processing procedure relating to estimation of deterioration of a subscriber line termination unit. At a predetermined timing, the distance measurement unit 11a of the maintenance function unit 11 of the terminal device 10 outputs the above-mentioned control signal to each of the multiple subscriber line termination devices 20 via the communication processing unit 12, and measures the distance between the terminal device 10 and the subscriber line termination device 20 to which the control signal is to be sent, for each subscriber line termination device 20, based on the time required to send and receive the output control signal (S11). The signal strength measuring unit 12a of the communication processing unit 12 of the terminal device 10 measures the strength of the optical signals propagated through the optical cable from the multiple subscriber line terminals 20 and received at the terminal device 10 for each of the subscriber line terminals 20 that are the source of the optical signals (S12).

[0027] The deterioration estimation unit 11b of the maintenance function unit 11 compares the distance measurement results in S11 and the optical signal strength measurement results in S12 with the table shown in Figure 2 stored in the memory unit 13, and determines whether or not the optical transmitting module of the subscriber line terminal 20 related to the measurement results among the multiple subscriber line terminals 20 satisfies the above-mentioned first or second condition related to deterioration as a precursor to a failure, etc. (S13).

[0028] If neither the first nor the second condition is satisfied (NO in S13), the degradation estimation unit 11b estimates that the above-mentioned degradation has not occurred in the optical transmitting module of the subscriber line terminal device 20 related to the measurement result, or that the possibility of such degradation is relatively low, and returns to S11.

[0029] On the other hand, when the first or second condition is satisfied (YES in S13), the degradation estimation unit 11b estimates that the above-mentioned degradation has occurred in the optical transmitting module of the subscriber line terminal device 20 related to the measurement result, or that the possibility of such degradation is relatively high (S14).

[0030] Following the estimation in S14, the maintenance function unit 11 outputs a signal indicating the estimation result that the above-mentioned deterioration has occurred in the optical transmitting module of the subscriber line terminal 20 related to the measurement result, or that the possibility of such deterioration is relatively high, to the management system 50 via the monitoring and control network 60, and causes the signal to be displayed on a display device (not shown) in the management system 50 (S15).

[0031] As described above, in the communication system according to this embodiment, the distance, which is the length of the optical fiber cable between the terminal device 10 and the subscriber line terminal 20, is measured, the strength of the optical signal received by the terminal device 10 from the subscriber line terminal 20 via the optical fiber cable is measured, and based on the distance measurement results and the optical signal strength measurement results, it is estimated that degradation, which is a precursor to a failure, has occurred in the transmission module of the subscriber line terminal 20, or that the possibility of such degradation is relatively high. This makes it possible to precisely predict an abnormality in the subscriber line terminal 20, compared to, for example, the conventional method of detecting a failure in the subscriber line terminal based only on changes in the strength of the optical signal transmitted from the subscriber line terminal 20 and received by the terminal device 10.

[0032] As described above, by predicting the signs of a failure, the line operator can continue communication services before a failure occurs by repairing or replacing the subscriber line termination device 20. In this way, by repairing or replacing the subscriber line termination device 20 before a failure occurs in the subscriber line termination device 20, the period during which communication services for users are affected is within the period required to repair or replace the subscriber line termination device 20, so that the impact on communication services for users can be minimized.

[0033] FIG. 4 is a block diagram showing an example of a hardware configuration of a terminal device of a communication system according to an embodiment of the present invention. In the example shown in Fig. 4, the terminal device 10 of the communication system according to the embodiment is configured by, for example, a server computer or a personal computer, and has a hardware processor 111A such as a CPU (Central Processing Unit). A program memory 111B, a data memory 112, an input / output interface 113, and a communication interface 114 are connected to the hardware processor 111A via a bus 115. The same is true for the subscriber line termination device 20 and the management system 50 of the communication system.

[0034] The communication interface 114 includes, for example, one or more wireless communication interface units, and enables transmission and reception of information to and from a communication network NW. As the wireless interface, for example, an interface that adopts a low-power wireless data communication standard such as a wireless LAN (Local Area Network) is used.

[0035] An input device 200 and an output device 300 that are attached to the terminal device 10 and used by a user or the like are connected to the input / output interface 113 . The input / output interface 113 takes in operation data input by a user or the like through an input device 200 such as a keyboard, a touch panel, a touchpad, a mouse, etc., and outputs output data to an output device 300 including a display device using liquid crystal or organic EL (Electro Luminescence), etc., for display. The input device 200 and the output device 300 may be devices built into the terminal device 10, or may be input devices and output devices of other information terminals that can communicate with the terminal device 10 via the network NW.

[0036] The program memory 111B is a non-transient tangible storage medium that is a combination of a non-volatile memory that can be written to and read from at any time, such as a hard disk drive (HDD) or a solid state drive (SSD), and a non-volatile memory such as a read only memory (ROM), and stores programs necessary for executing various control processes, etc. according to one embodiment.

[0037] The data memory 112 is a tangible storage medium, for example, a combination of the above-mentioned nonvolatile memory and a volatile memory such as RAM (Random Access Memory), and is used to store various data acquired and created in the course of various processes.

[0038] The terminal device 10 according to an embodiment of the present invention can be configured as an information processing device having a maintenance function unit 11 and a communication processing unit 12 shown in FIG. 1 as software-based processing function units.

[0039] Each information storage unit and the storage unit 13 used as a working memory by each unit of the terminal device 10 can be configured by using the data memory 112 shown in Fig. 4. However, these configured storage areas are not essential components in the terminal device 10, and may be areas provided in a storage device such as an external storage medium such as a Universal Serial Bus (USB) memory, or a database server located in the cloud.

[0040] The processing function units in each of the maintenance function unit 11 and the communication processing unit 12 can be realized by reading and executing a program stored in the program memory 111B by the hardware processor 111A. Note that some or all of these processing function units may be realized in various other forms, including integrated circuits such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

[0041] The methods described in each embodiment may be stored as a program (software means) that can be executed by a computer on a recording medium such as a magnetic disk (floppy disk, hard disk, etc.), an optical disk (CD-ROM, DVD, MO, etc.), or a semiconductor memory (ROM, RAM, flash memory, etc.), and may be distributed by transmitting the program via a communication medium. The programs stored on the medium include a setting program that configures the software means (including not only execution programs but also tables and data structures) that the computer executes. The computer that realizes the present device reads the program recorded on the recording medium, and in some cases, configures the software means by the setting program, and executes the above-mentioned processing by controlling the operation of the software means. The recording medium in this specification is not limited to a recording medium for distribution, but also includes a storage medium such as a magnetic disk or semiconductor memory provided inside the computer or in a device connected via a network.

[0042] The present invention is not limited to the above-mentioned embodiment, and can be modified in various ways without departing from the gist of the present invention. The embodiments may be combined as appropriate, and in that case, the combined effect can be obtained. Furthermore, the above-mentioned embodiment includes various inventions, and various inventions can be extracted by combinations selected from the multiple components disclosed. For example, if the problem can be solved and the effect can be obtained even if some components are deleted from all the components shown in the embodiment, the configuration from which the components are deleted can be extracted as an invention. [Explanation of symbols]

[0043] 10…Terminal equipment 11…Maintenance function department 11a...Distance measurement section 11b...Deterioration estimation section 12...Communication processing unit 12a…Signal strength measurement section 13...Storage section 20…Subscriber line termination equipment 30...Relay network 40…Higher-level communication network 50...Management system 60...Monitoring and control network

Claims

1. A terminal device in a passive optical communication network in which a terminal device and a subscriber line terminal are connected, a distance measuring unit for measuring the distance between the terminal device and the subscriber line termination device; a signal strength measuring unit for measuring the strength of a signal received from the subscriber line termination device; an estimation unit that estimates the occurrence of a precursor of a fault in the subscriber line termination device based on a result of distance measurement by the distance measurement unit and a result of signal strength measurement by the signal strength measurement unit; Equipped with The estimation unit is when the distance measured by the distance measuring unit is a predetermined distance longer than a normal distance and the strength measured by the signal strength measuring unit is a predetermined strength stronger than a normal strength, the occurrence of a precursor of a failure in the subscriber line termination device is estimated. Terminal equipment.

2. A terminal device in a passive optical communication network in which a terminal device and a subscriber line terminal are connected, comprising: a distance measuring unit for measuring the distance between the terminal device and the subscriber line termination device; a signal strength measuring unit for measuring the strength of a signal received from the subscriber line termination device; an estimation unit that estimates the occurrence of a precursor of a fault in the subscriber line termination device based on a result of distance measurement by the distance measurement unit and a result of signal strength measurement by the signal strength measurement unit; Equipped with The estimation unit is when the distance measured by the distance measuring unit is a predetermined length shorter than a normal distance and the strength measured by the signal strength measuring unit is a predetermined strength weaker than a normal strength, the occurrence of a precursor of a failure in the subscriber line termination device is estimated. Terminal equipment.

3. A method performed by a terminal device in a passive optical communication network in which a terminal device and a subscriber line terminal are connected, comprising the steps of: measuring a distance between the terminal device and the subscriber line termination device by a distance measuring unit of the terminal device; measuring the strength of a signal received from the subscriber line termination device by a signal strength measuring unit of the terminal device; an estimation unit of the terminal device estimates occurrence of a precursor of a fault in the subscriber line termination device based on the distance measurement result and the signal strength measurement result; Equipped with The estimating step comprises: and estimating the occurrence of a precursor of a fault in the subscriber line termination device when the measured distance is a predetermined distance longer than a normal distance and the measured strength is a predetermined strength stronger than a normal strength. Communication methods.

4. A method performed by a terminal device in a passive optical communication network in which the terminal device and a subscriber line terminal are connected, comprising: measuring a distance between the terminal device and the subscriber line termination device by a distance measuring unit of the terminal device; measuring the strength of a signal received from the subscriber line termination device by a signal strength measuring unit of the terminal device; an estimation unit of the terminal device estimates occurrence of a precursor of a fault in the subscriber line termination device based on the distance measurement result and the signal strength measurement result; Equipped with The estimating step comprises: and estimating the occurrence of a precursor of a fault in said subscriber line termination device when said measured distance is a predetermined distance shorter than a normal distance and said measured strength is a predetermined strength weaker than a normal strength. Communication methods.

5. A communication processing program that causes a processor to function as each unit of the terminal device according to claim 1 or 2.

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