Optical communication system and reset method

Abstract

The purpose of the present invention is to provide an optical communication system that can enhance cost reduction and the operation of an optical fiber network.　In an optical communication system 301 according to the present invention: power feeding light is fed from a parent node 10 to child nodes 20 through optical fibers 52; the parent node 10 superposes a signal on the power feeding light and transmits a reset signal to one of the child nodes 20 through an optical fiber 52; the child node 20 receives the reset signal through the optical fiber 52 to reset the child node itself; the parent node 10 superposes a signal on the power feeding light and transmits a reset completion confirmation signal to the child node 20 through the optical fiber 52; the child node 20, after resetting itself and after receiving the reset completion confirmation signal, intensity-modulates the power feeding light fed from the parent node 10 into a response signal and transmits the signal to the parent node 10 through the optical fiber 52; and the parent node 10 determines the success or failure of the resetting of the child node 20 on the basis of the presence or absence of the response signal transmitted from the child node 20 through the optical fiber 52.

Description

[Technical Field]

[0001] The present disclosure relates to an optical communication system including optically powered optical nodes, and a reset method for remotely resetting the optical nodes. [Background technology]

[0002] In optical fiber networks, particularly access networks that connect communication devices installed in communication buildings with user-side communication terminals, optical fiber core wires are frequently switched, such as by installing new routes or changing to different routes, in order to efficiently use the facilities during installation and maintenance. Normally, such core wire switching work is performed by an on-site technician who manually switches the optical fiber core wire connections, but a technology has been proposed that enables optical fiber core wire connections to be switched remotely.

[0003] For example, Non-Patent Documents 1 and 2 disclose a method in which a single laser can simultaneously realize the functions of optical power supply and control of multiple optical switches included in an optical node in a system consisting of a power supply control light source installed in a power supply environment such as a central office and one or more optical nodes installed remotely. This optical node is installed in an optical fiber network and performs mutual connection and switching of communication / main signal optical fiber core wire units.

[0004] 1 is a diagram illustrating a configuration in which optical power is supplied to optical nodes in an optical fiber network in a parallel manner. Optical power supply light emitted from a power supply control light source 11 inside an optical node (hereinafter, the optical node will be referred to as a "parent node") installed inside a communications building or the like is transmitted to multiple optical nodes (hereinafter, the optical node will be referred to as a "child node") via one of multiple power supply optical fibers 52 by a channel selector (optical switching device) 12 inside or near the parent node 10. The power supply light is photoelectrically converted by an optical power supply converter 21 in the child node 20 and stored as electricity in a power storage unit 22.

[0005] In addition, a control signal generated by intensity modulation or the like is superimposed on the optical power supply light. This control signal is, for example, a serial communication method. The control signal received by the child node 20 operates a device such as a PIC (Peripheral Interface Controller) microcomputer 23 within the child node 20. If necessary, the child node 20 may also return a control signal to the parent node 10. Note that, because this child node 20 is installed in a wide outdoor location, it does not use a commercial power source but operates on optical power supplied from the parent node 10.

[0006] FIG. 2 is a diagram illustrating a serial optical power supply configuration for optical nodes in an optical fiber network. Optical power supply light emitted from a power supply control light source 11 in a parent node 10, such as in a communications building, is transmitted sequentially to multiple child nodes 20 via a single power supply optical fiber. Each child node 10 is equipped with a 1×2 optical switch (n×n optical switch) 24, which switches the direction of the optical power supply light between supplying it to an optical power supply converter 21 in its own child node 20 or sending it to a subsequent child node 20. The switching of this 1×2 optical switch 24 is performed by a control signal superimposed on the optical power supply light. In this way, the 1×2 optical switch 24 switches the optical fiber route so that the power supply control light source 11 and each child node 20 can communicate one-to-one in a time-division manner, according to the control signal.

[0007] If the stored voltage value of the power storage unit 22 falls below a predetermined voltage value, it will be impossible to control or drive the PIC microcomputer 23 or the optical switch 24. For this reason, when there are multiple child nodes 20 as in the configurations of Figures 1 and 2, the operation is premised on the fact that optical power is supplied by appropriately switching the channel selector 12 or each 1x2 optical switch 24, and that a constant amount of electricity is always maintained stored in each power storage unit 22.

[0008] In addition, in order to always maintain a constant amount of stored power in the power storage unit 22 of each child node 20, the power supply control light source 11 may use a control signal to inquire and check the amount of stored power in the power storage unit 22 of the child node 20 at any time. [Prior art documents] [Non-patent literature]

[0009] [Non-Patent Document 1] 2021 Institute of Electronics, Information and Communication Engineers General Conference B-13-16, "Study on remote optical path switching nodes for future optical access networks" [Non-patent document 2] 2022 Institute of Electronics, Information and Communication Engineers General Conference B-13-28, "A Study on Serial Connection Method of Remote Optical Path Switching Nodes" Summary of the Invention [Problem to be solved by the invention]

[0010] In an optical fiber network made up of the above optical nodes, it may be necessary to restart (reset) a child node. For example, this may occur when new firmware is installed in the PIC microcomputer mounted in the child node by some means, changing from the old firmware to the new firmware. In such cases, a technician must go to the site and reset each child node. However, having technicians go to the site to reset each child node poses the problem of making it difficult to reduce costs and improve the operation of the optical fiber network.

[0011] SUMMARY OF THE INVENTION In order to solve the above problems, an object of the present invention is to provide an optical communication system and a reset method that can reduce costs and improve the operation of an optical fiber network. [Means for solving the problem]

[0012] In order to achieve the above object, the optical communication system according to the present invention is configured to enable a parent node to remotely reset a child node and to confirm whether the remote reset was successful or unsuccessful.

[0013] Specifically, the optical communication system according to the present invention is an optical communication system in which one parent node and one or more child nodes are connected by an optical fiber for a main signal and an optical fiber for optical power feeding, and light for driving power is supplied from the parent node to the child node through the optical fiber for optical power feeding, The parent node is superimposing a signal on the light for driving power, and transmitting a reset signal and a reset completion confirmation signal to any one of the child nodes via the optical fiber for optical power feeding, and determining whether the reset of the child node has been successful based on the presence or absence of a response signal transmitted from the child node via the optical fiber for optical power feeding; The child node is receiving the reset signal from the optical fiber for optical power feeding to reset itself, and after resetting itself and receiving the reset completion confirmation signal, superimposing a signal on the light for driving power supplied from the parent node to generate the response signal and transmitting the response signal to the parent node through the optical fiber for optical power feeding. It is characterized by:

[0014] Furthermore, a child node resetting method according to the present invention is a resetting method for a child node in an optical communication system in which one parent node and one or more child nodes are connected by an optical fiber for a main signal and an optical fiber for optical power feeding, and light for driving power is supplied from the parent node to the child node by the optical fiber for optical power feeding, the resetting method comprising: the parent node superimposing a signal on the light for driving power and transmitting a reset signal to any one of the child nodes through the optical fiber for optical power feeding; the child node receiving the reset signal from the optical power feeding optical fiber and resetting itself; the parent node transmitting a reset completion confirmation signal through the optical fiber for optical power feeding; the child node, after resetting itself and receiving the reset completion confirmation signal, superimposing a signal on the light for driving power supplied from the parent node to generate the response signal, and transmitting the response signal to the parent node through the optical fiber for optical power supply; and the parent node determines whether the reset of the child node has been successful based on the presence or absence of a response signal transmitted from the child node through the optical fiber for optical power feeding; Do the following.

[0015] The present optical communication system and reset method allows a parent node to remotely reset a child node, and furthermore, the success or failure of the remote reset can be confirmed, eliminating the need for a technician to travel to the site. This saves the cost and time of dispatching a technician to the site. Therefore, the present invention can provide an optical communication system and reset method that can reduce costs and improve the operation of an optical fiber network.

[0016] Child nodes are powered and controlled by optical power supply light from a single power supply control light source from the parent node. Since the stored power of child nodes that are not optically powered decreases, it is necessary to efficiently supply optical power to multiple child nodes.

[0017] Therefore, the optical communication system according to the present invention is characterized in that, during the period from when the parent node transmits the reset signal to any one of the child nodes until when the parent node transmits the reset completion confirmation signal, the light for the driving power is supplied to any of the child nodes other than the child node. By utilizing the reset time to store power in the other child nodes, the efficiency of optical power supply can be improved.

[0018] In the optical communication system according to the present invention, if the parent node does not receive the response signal after transmitting the reset completion confirmation signal, it is preferable that the parent node transmits the reset signal and the reset completion confirmation signal a specified number of times. Even if the reset of the child node fails, the reset may be successful by retrying. By automatically repeating the reset retry, the number of worker man-hours can be reduced, leading to cost reduction.

[0019] In the optical communication system according to the present invention, it is preferable that the child node includes in the response signal the start time at which the reset was initiated and the completion time at which the reset was completed, and that the parent node extracts the start time and the completion time from the response signal and manages the start time and the completion time for each child node. By having the parent node know the time required for the reset of each child node, it is possible to appropriately set the timing for sending the reset completion confirmation signal. In other words, it is possible to avoid issuing the reset completion confirmation signal while the child node is resetting or avoid wasting time after the child node has completed the reset.

[0020] The above inventions can be combined as much as possible. [Effects of the Invention]

[0021] The configuration of the present invention makes it possible to remotely restart (remotely reset) child nodes in an optical fiber network made up of optical nodes, and furthermore, to confirm whether the remote reset was successful or not. This allows multiple remote child nodes to be reset collectively from a parent node without requiring a technician to visit the site. Therefore, the present invention can provide an optical communication system and a reset method that can reduce costs and improve the operation of an optical fiber network. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1 is a diagram illustrating a mode in which optical power is supplied to optical nodes in an optical fiber network in parallel. [Figure 2] FIG. 1 is a diagram illustrating a mode in which optical power is supplied to optical nodes in an optical fiber network in series. [Figure 3] 1 is a diagram illustrating an optical communication system according to the present invention. [Figure 4] FIG. 1 is a diagram illustrating a method for resetting an optical node according to the present invention. [Figure 5] 1 is a diagram illustrating an optical communication system according to the present invention. [Figure 6] FIG. 1 is a diagram illustrating a method for resetting an optical node according to the present invention. [Figure 7] 1 is a diagram illustrating an optical communication system according to the present invention. [Figure 8] FIG. 1 is a diagram illustrating a method for resetting an optical node according to the present invention. [Figure 9] 1 is a diagram illustrating an optical communication system according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] The following description of the preferred embodiments of the present invention will be given with reference to the accompanying drawings. The preferred embodiments described below are examples of the present invention, and the present invention is not limited to the preferred embodiments. In this specification and the drawings, components having the same reference numerals are intended to represent the same components.

[0024] Each child node described in the following embodiments drives the control unit and devices within the node using the power stored in the power storage unit. When each child node is not receiving optical power, i.e., when the channel selector 12 is switched to the direction of another child node in Fig. 1, or when the 1 × 2 optical switch 24 is switched to the rear child node side in Fig. 2, the power stored in the power storage unit 22 decreases over time due to the operation of the PIC microcomputer 23, natural discharge, etc. Moreover, optical power feeding to the child nodes is performed through the optical fiber 52 for power feeding, not the optical fiber 51 for the main signal.

[0025] (Embodiment 1) 3 is a diagram illustrating an optical communication system 301 according to this embodiment. The optical communication system 301 is an optical communication system in which one parent node 10 and one or more child nodes 20 are connected by a main signal optical fiber 51 and an optical power feeding optical fiber 52, and light for driving power is supplied from the parent node 10 to the child node 20 by the optical power feeding optical fiber 52, The parent node 10 is a signal is superimposed on the light for driving power, and a reset signal and a reset completion confirmation signal are transmitted to any one child node 20 via the optical power feeding optical fiber 52; and whether or not the reset of the child node 20 has been successful is determined based on the presence or absence of a response signal transmitted from the child node 20 via the optical power feeding optical fiber 52; Child node 20 is The node 10 receives the reset signal from the optical fiber 52 for optical power supply and resets itself, and after resetting itself and receiving the reset completion confirmation signal, superimposes a signal on the light for driving power supplied from the parent node 10 to generate the response signal, and transmits the response signal to the parent node 10 via the optical fiber 52 for optical power supply. In this embodiment and the following embodiments, an example will be described in which a signal is superimposed on the light for driving power by intensity-modulating the light for driving power. Note that superimposing a signal on the light for driving power may also be achieved by other methods, such as wavelength-multiplexing a signal with a different wavelength from the power supply light onto the light for driving power.

[0026] The parent node 10 of the optical communication system 301 has the following four additional functions compared to the parent node of the optical communication system described in FIG. (Additional function 1) A transmission function for transmitting a reset signal generated by modulating the power supply light from the parent node 10 to a specific child node 20. (Additional function 2) A transmission function for transmitting a reset completion confirmation signal generated by modulating the power supply light from the parent node 10 to a specific child node 20. (Additional function 3) A receiving function for receiving a response signal confirming the completion of resetting that is generated by the child node 20 after the resetting is completed by modulating the reflected light of the power supply light and transmitted to the parent node 10. (Additional function 4) A judgment function that determines whether the reset was successful or unsuccessful based on whether or not a response signal was received.

[0027] As for additional function 4, success / failure is determined, for example, based on whether a response signal indicating that the reset has been completed is received within a certain period of time after the reset completion confirmation signal is sent. 3, the symbol Sig indicates a reset signal, a reset completion confirmation signal, and a response signal that are transmitted and received between the parent node 10 and the child node 20.

[0028] In contrast to the child nodes of the optical communication system described in FIG. 1, the child node 20 of the optical communication system 301 has the following three additional functions. (Additional function a) A receiving function for receiving a reset signal, which is modulated power supply light, from the parent node 10. (Additional function b) An execution function that executes a reset on the PIC microcontroller 23 after receiving a reset signal. (Additional function c) A function of transmitting a response signal generated by modulating the reflected light of the power supply light to the parent node 20 after the reset is completed.

[0029] 4 is a sequence diagram illustrating a method for resetting a child node 20 in the optical communication system 301. Note that this sequence assumes that the child node 20 has sufficient stored power to execute a remote reset, that no other commands are being executed in the child node 20 (multiple commands are not being executed simultaneously), and that the child node 20 is in a state where it can normally receive the reset request command.

[0030] The reset method is a reset method for resetting a child node 20 in an optical communication system 301, The parent node 10 superimposes a signal on the light for driving power and transmits a reset signal to any one of the child nodes 20 via the optical fiber 52 for optical power supply (step S01); The child node 20 receives the reset signal from the optical fiber 52 for optical power supply and resets itself (step S02); The parent node 10 intensity-modulates the light for driving power and transmits a reset completion confirmation signal to the child node 20 via the optical fiber 52 for optical power supply (step S03). After resetting itself and receiving the reset completion confirmation signal, the child node 20 superimposes a signal on the light for driving power supplied from the parent node 10 to generate the response signal, and transmits the response signal to the parent node 10 through the optical fiber 52 for optical power supply (step S04); and The parent node 10 determines whether the reset of the child node 20 has been successful or not based on the presence or absence of a response signal transmitted from the child node 20 through the optical fiber 52 for optical power feeding (step S05); Do the following.

[0031] In this embodiment, a case where the child node 20#1 is remotely reset will be described. Step S01 The parent node 10 drives the channel selector 12 or drives the 1×2 optical switch 24 for the child node 20#1, bringing the optical path into a state in which it can optically feed power to the child node 20#1. Then, the parent node 10 sends a reset signal to the child node 20#1 using additional function 1. The child node 20#1 receives the reset signal using additional function a. Step S02 The child node 20#1 resets itself with the additional function b. Step S03 The parent node 10 uses the additional function 2 to transmit a reset completion confirmation signal to the child node 20#1. Step S04 If the child node 20#1 has completed its own reset, it transmits a response signal as a response to the reset completion confirmation signal using the additional function c. Step S05 The parent node 10 receives the response signal using additional function 3. However, there are cases where the parent node 10 is unable to receive the response signal within the specified time from the transmission of the reset completion confirmation signal. Therefore, the parent node 10 uses additional function 4 to determine whether the reset was successful or unsuccessful based on whether or not the response signal was received.

[0032] The functions and sequences described above allow the parent node 10 to remotely restart (remote reset) the child node 20, and further allow the parent node 10 to confirm whether the remote reset was successful or unsuccessful.

[0033] Although this embodiment has been described with reference to the parallel optical communication system of FIG. 1, the serial optical communication system of FIG. 2 can also be remotely reset in the same manner.

[0034] (Embodiment 2) 5 is a diagram illustrating an optical communication system 302 according to this embodiment. The optical communication system 302 differs from the optical communication system 301 in FIG. 3 in that, from the time when the parent node 10 transmits the reset signal to any one of the child nodes 20 (e.g., child node 20#1) until the time when the parent node transmits the reset completion confirmation signal, the light for driving power is supplied to any one of the child nodes other than the child node (e.g., child node 20#2).

[0035] Specifically, the optical communication system 302 has the following two functions added to the parent node 10 of the optical communication system 301. (Additional function 5) A function for determining the time required to reset all child nodes 20. (Additional function 6) A function that allows any child node to supply optical power to other child nodes or execute child node devices (such as switching the connection of optical fiber cores) while the node is reset.

[0036] 6 is a sequence diagram illustrating a method for resetting a child node 20 in an optical communication system 302. As in the first embodiment, a case where a child node 20#1 is remotely reset will be described. In this diagram, only the parts that differ from the sequence in FIG. Step S11 After step S01, the parent node 10 drives the channel selector 12 by the additional function 6 to switch the destination of the optical power supply light to a child node other than the child node 20#1 (the child node 20#2 in this embodiment). Then, the parent node 10 supplies optical power to the child node 20#2 or executes a command. During this time, step S02 is performed in the child node 10#1. Step S12 The parent node 10 receives the time T required for resetting, which is stored in advance in the additional function 5. RAfter the above has elapsed, the channel selector 12 is driven, and the destination of the optical power supply light is returned to the child node 20#1. Thereafter, steps S03 and subsequent steps are performed on the child node 20#1.

[0037] The functions and sequences described above make it possible in a parallel optical communication system to supply optical power to other child nodes 20 or to execute other commands while a child node 20 is executing a reset command. This allows for efficient operation of one power-feed-controlled light source 11 in the parent node 10.

[0038] (Embodiment 3) 7 is a diagram illustrating an optical communication system 303 according to this embodiment. In the optical communication system 303, the following two functions are added to the child node 20 of the optical communication system 303 compared to the child node of the optical communication system described in FIG. (Additional function d) A function in which the child node 20 (child node 20#1 in this embodiment) that has received a reset signal autonomously switches its own 1×2 optical switch 24 to the backward side before starting the reset. (Additional function e) A function of switching the 1×2 optical switch 24 to its own side after the child node 20 has been reset.

[0039] 8 is a sequence diagram illustrating a method for resetting a child node 20 in an optical communication system 301. As in the first embodiment, a case where a child node 20#1 is remotely reset will be described. In this diagram, only the parts that differ from the sequence in FIG. 4 will be described. Step S21 In step S01, the child node 10#1 receives the reset signal and autonomously switches its own 1×2 optical switch 24 to the backward side. Step S22 While the reset command is being executed in child node 10#1, parent node 10 switches the destination of the optical power supply light to a child node other than child node 20#1 (child node 20#3 in this embodiment). Then, parent node 10 supplies optical power to child node 20#3 or executes a command. During this time, step S02 is performed in the child node 10#1. Step S23 The parent node 10 receives the time T required for resetting, which is stored in advance in the additional function 5. R After the above has elapsed, the transmission destination of the optical power supply light is returned from child node 20#3 to child node 20#1 (end of optical power supply / command execution). Step S24 After completing the execution of the reset command in step S02, the child node 20#1 switches its own 1×2 optical switch 24 to its own side. Thereafter, steps S03 and subsequent steps are performed on the child node 20#1.

[0040] The functions and sequences described above make it possible to supply optical power to other child nodes 20 or to execute other commands while a child node 20 is executing a reset command in a serial optical communication system. This allows for efficient operation of one power-feed control light source 11 in the parent node 10.

[0041] (Embodiment 4) In the first to third embodiments, if the parent node 10 cannot receive a response signal from the child node 20 in step S05 (if the reset has failed), steps S01 to S05 are automatically repeated for the child node 20 for which the reset has failed. This repetition is preferably repeated a certain number of times (N times) until the parent node 10 can receive a response signal.

[0042] (Embodiment 5) 9 is a diagram for explaining the operation of the optical communication system 304 of this embodiment. In the optical communication system of this embodiment, the following functions are added to the optical communication systems (301 to 303) of the first to third embodiments. (Additional function f) A function added to the child node 20, which returns the reset start time and completion time together with a response signal sent after the reset is completed. (Additional function 7) A function added to the parent node 10, which manages the number or identifier of the child node 10 (e.g., child node #1) contained in the response signal from the child node 20, as well as the reset start time and completion time data.

[0043] The above-described functions enable the parent node 10 of the optical communication system of this embodiment to calculate the time required for resetting each child node 20 from the start and completion times of the reset. In other words, it is possible to avoid sending the reset completion confirmation signal in step S03 during resetting (which would result in repeated resetting because the child node cannot send a response signal) or some time after the reset is complete (which would result in a period of inactivity), thereby improving the availability of the optical communication system. [Explanation of symbols]

[0044] 10: Parent node 11: Power supply control light source 12: Channel selector 20, 20#1, 20#2, 20#3: Child nodes 21: Optical power converter 22: Power storage unit 23:PIC microcomputer 24: Optical switch 51: Optical fiber for main signal 52: Optical fiber for optical power supply 301-304: Optical communication systems

Claims

1. An optical communication system in which one parent node and one or more child nodes are connected by an optical fiber for a main signal and an optical fiber for optical power supply, and light for driving power is supplied from the parent node to the child node through the optical fiber for optical power supply, The parent node is superimposing a signal on the light for driving power, and transmitting a reset signal and a reset completion confirmation signal to any one of the child nodes via the optical fiber for optical power feeding, and determining whether the reset of the child node has been successful based on the presence or absence of a response signal transmitted from the child node via the optical fiber for optical power feeding; The child node is receiving the reset signal from the optical fiber for optical power feeding to reset itself, and after resetting itself and receiving the reset completion confirmation signal, superimposing a signal on the light for driving power supplied from the parent node to generate the response signal and transmitting the response signal to the parent node through the optical fiber for optical power feeding. An optical communication system comprising:

2. The optical communication system described in claim 1, characterized in that, from the time when the parent node transmits the reset signal to any one of the child nodes until the time when the parent node transmits the reset completion confirmation signal, light for the driving power is supplied to any of the child nodes other than the child node.

3. 2. The optical communication system according to claim 1, wherein if the parent node does not receive the response signal after transmitting the reset completion confirmation signal, the parent node transmits the reset signal and the reset completion confirmation signal a specified number of times.

4. The child node includes in the response signal a start time at which the reset was initiated and a completion time at which the reset was completed; and The parent node extracts the start time and the completion time from the response signal and manages the start time and the completion time for each of the child nodes.

2. The optical communication system according to claim 1,

5. 1. A reset method for resetting a child node in an optical communication system in which one parent node and one or more child nodes are connected by an optical fiber for a main signal and an optical fiber for optical power supply, and light for driving power is supplied from the parent node to the child node through the optical fiber for optical power supply, comprising: the parent node superimposing a signal on the light for driving power and transmitting a reset signal to any one of the child nodes through the optical fiber for optical power feeding; the child node receiving the reset signal from the optical power feeding optical fiber and resetting itself; the parent node transmitting a reset completion confirmation signal through the optical fiber for optical power feeding; the child node, after resetting itself and receiving the reset completion confirmation signal, superimposing a signal on the light for driving power supplied from the parent node to generate a response signal, and transmitting the response signal to the parent node through the optical fiber for optical power supply; and the parent node determines whether the reset of the child node has been successful based on the presence or absence of the response signal transmitted from the child node through the optical fiber for optical power feeding; How to reset.

6. The reset method described in claim 5, characterized in that the parent node supplies light for the driving power to any one of the child nodes other than the child node in question during the period from after the parent node transmits the reset signal to the child node until the parent node transmits the reset completion confirmation signal.

7. 6. The reset method according to claim 5, wherein, if the parent node does not receive the response signal after transmitting the reset completion confirmation signal, the parent node transmits the reset signal and the reset completion confirmation signal a specified number of times.

8. The response signal includes a start time at which the child node started the reset and a completion time at which the child node completed the reset; and The parent node extracts the start time and the completion time from the response signal and manages the start time and the completion time for each of the child nodes.

6. The reset method according to claim 5,

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