Optical node, remote control system, and remote control method

Abstract

The purpose of the present invention is to provide an optical node, a remote control system, and a remote control method that are capable of improving the communication speed of uplink signals.　An optical node 30 according to the present invention comprises: a wavelength division multiplexing (WDM) coupler 33 that splits laser light having different wavelengths into rays corresponding to the wavelengths, the light being supplied via an optical fiber 20; a photoelectric conversion element 34 that receives at least one of the rays and subjects the ray(s) to photoelectric conversion; a power storage unit 35 that stores power received from the photoelectric conversion element 34; reflection switches (38-40) that switch between a reflective state and a non-reflective state for the other ray(s) and return the reflected ray to the optical fiber 20 via the WDM coupler 33; and a control unit 37 that breaks down information from modules (31, 32) to obtain drive signals and drives the reflection switches (38-40) by using power from the power storage unit 35.

Description

[Technical Field]

[0001] The present invention relates mainly to a remotely controllable optical node in an optical fiber network, a remote control system including the same, and a remote control method thereof. [Background technology]

[0002] In optical fiber networks, particularly in access networks connecting telecommunications carriers and optical terminals, optical line switching is performed at a certain frequency, such as connecting optical fiber cores to a desired route or changing the route, in order to efficiently use the facilities during installation and maintenance. Normally, such work is performed by going to the site and physically switching the connections, but a technology has been proposed to perform this work remotely using optical switches. For example, Non-Patent Document 1 discloses a remote control system that drives optical switches and optical sensors with power stored by optical power supply. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Tomohiro Kawano, Tatsuya Fujimoto, Kazuhide Nakae, Hiroshi Watanabe, Kazunori Katayama, "A Study on Optical Power Supply Control of Remote Optical Path Switching Nodes," 2021 IEICE Communication Society Conference, B-13-18 Summary of the Invention [Problem to be solved by the invention]

[0004] The system disclosed in Non-Patent Document 1 is equipped with only one reflective switch for upstream light, which has a switching time of several milliseconds. This system has the problem that the communication speed of the upstream signal is limited by the switching time of the reflective switch, making it difficult to improve the communication speed.

[0005] Therefore, in order to solve the above problems, an object of the present invention is to provide an optical node, a remote control system, and a remote control method that can improve the communication speed of upstream signals. [Means for solving the problem]

[0006] In order to achieve the above object, an optical node according to the present invention is provided with a reflection switch for each of a plurality of wavelengths supplied, and divides data for parallel transmission.

[0007] Specifically, the optical node according to the present invention comprises: a wavelength division multiplexing (WDM) coupler that splits laser light of multiple wavelengths supplied via an optical fiber into individual wavelengths; a photoelectric conversion element that receives at least one of the laser beams branched for each wavelength and performs photoelectric conversion; a power storage unit that stores power from the photoelectric conversion element; a reflection switch that switches between a reflection state and a non-reflection state for the other laser beams branched for each wavelength and returns the reflected laser beams to the optical fiber via the WDM coupler; a control unit that divides information from the module into drive signals and drives each of the reflection switches using the power of the power storage unit; Equipped with.

[0008] The present invention also provides a remote control method for the optical node, comprising: A wavelength division multiplexing (WDM) coupler is used to split laser light of multiple wavelengths supplied via an optical fiber into individual wavelengths. receiving at least one of the laser beams split into wavelengths with a photoelectric conversion element and performing photoelectric conversion; storing the power from the photoelectric conversion element in a power storage unit; Dividing the module information into drive signals and driving each of the reflective switches using the power of the power storage unit; The optical switch is switched by the drive signal between a reflective state and a non-reflective state for the other laser beams branched for each wavelength, and the reflected laser beams are returned to the optical fiber via the WDM coupler. The method is characterized by carrying out the following.

[0009] Furthermore, the remote control system according to the present invention comprises: the optical node; a supervisory control device connected to the optical node by the optical fiber; A remote control system comprising: The monitoring and control device includes: a plurality of lasers each supplying laser light of a different wavelength to the optical fiber; a modulator that modulates the laser light having a wavelength received by the photoelectric conversion element with the control signal; a light receiver for receiving each of the other laser beams reflected by the reflection switch; a management unit that combines signals from the optical receivers to reproduce information from the modules; The present invention is characterized by comprising:

[0010] The remote control system according to the present invention further comprises: supplying laser beams of different wavelengths to the optical fiber from a plurality of lasers; modulating the laser light of a wavelength received by the photoelectric conversion element with the control signal; receiving the other laser light reflected by the reflective switch with a photoreceiver; and combining signals from the optical receivers to recover the information of the module; The method is characterized in that the following is further performed.

[0011] Here, the control unit further drives the module using the power of the power storage unit in accordance with a control signal included in the laser light received by the photoelectric conversion element. For example, the module is an optical sensor, a communication line selector switch, or both.

[0012] In a system consisting of a monitoring and control device on the optical supply side and one or more optical nodes located remotely, the present invention provides optical power supply from the monitoring and control device using multiple lasers with different wavelengths, and simultaneously realizes control of the optical switches and modules for each wavelength provided in the optical nodes, and parallel upstream communication at multiple wavelengths using the optical switches, thereby improving the upstream communication speed.

[0013] Therefore, the present invention can provide an optical node, a remote control system, and a remote control method that can improve the communication speed of an upstream signal. [Effects of the Invention]

[0014] The present invention can provide an optical node, a remote control system, and a remote control method that can improve the communication speed of an upstream signal. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a diagram illustrating an optical node and its remote control system according to the present invention; [Figure 2] 1 is a diagram illustrating a remote control method according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] 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.

[0017] 1 is a diagram illustrating a remote control system 301 according to this embodiment. The remote control system 301 includes an optical node 30 and a monitoring and control device 50 connected to the optical node 30 via an optical fiber 20. The monitoring and control device 50 a plurality of lasers (2 to 5) each supplying laser light of a different wavelength to the optical fiber; a modulator in the controller 1 that modulates the laser light of the wavelength received by the photoelectric conversion element 34 with a control signal; photoreceivers (9-11) for receiving the other laser beams reflected by the reflection switches (38-40); a management unit in the controller 1 that combines signals from the photodetectors (9-11) to reproduce information from the modules (31, 32); Equipped with.

[0018] The monitoring and control device 50 is installed in an environment where power can be provided. The monitoring and control device 50 is composed of lasers (2 to 5) that output light of different wavelengths, a WDM coupler 6, an optical circulator 7, a WDM coupler 8 for receiving light, optical receivers (9 to 11), and a controller 1. The controller 1 has a modulator and, for example, instructs the laser 2 to modulate the laser light output from the laser 2 so that the laser light contains information. On the other hand, the lasers 3 to 5 output unmodulated laser light. The laser light output from the lasers (2 to 5) is multiplexed by the WDM coupler 6 and input to the transmission optical fiber 20 via the optical circulator 7. Note that, although there are four lasers (four wavelengths) in FIG. 1, the number is not limited to this.

[0019] The optical node 30 is installed in any location, for example, a location without a power source. a wavelength division multiplexing (WDM) coupler 33 that splits laser light of multiple wavelengths supplied via the optical fiber 20 into individual wavelengths; a photoelectric conversion element 34 that receives at least one of the laser beams branched for each wavelength and performs photoelectric conversion; a power storage unit 35 that stores power from the photoelectric conversion element 34; a reflection switch (38-40) that switches between a reflection state and a non-reflection state for the other laser beams branched for each wavelength, and returns the reflected laser beams to the optical fiber 20 via a WDM coupler 33; a control unit 37 that divides information from the modules (31, 32) into drive signals and drives each of the reflection switches (38-40) using the power of the power storage unit 35; Equipped with. The optical node 30 is connected to the monitor control device 50 via the transmission line optical fiber 20. In this manner, this embodiment is configured such that one optical node 30 is connected to one monitor control device 50 via the transmission line optical fiber 20.

[0020] The downstream light propagated from the monitoring and control device 50 to the optical node 30 supplies drive power to the modules (communication line changeover optical switch 31 and optical sensor 32) included in the optical node 30, and a control signal for switching an arbitrary port of the communication line changeover switch 31 and a control signal for the optical sensor 32 are also superimposed on the downstream light. In this embodiment, the laser light with wavelength λ0 output by the laser 2 serves as the drive power and control signal. The upstream light from the optical node 30 to the monitoring and control device 50 is used to communicate the state of the optical node 30 and data from the optical sensor 32 to the monitoring and control device 50.

[0021] The optical node 30 optically branches downstream light from the monitor and control device 50 using a WDM coupler 33. Of the branched light, light with wavelength λ0 (light emitted from the laser 2 to supply drive power) is converted into an electrical signal by a photoelectric conversion element 34 and stored in a power storage unit 35. The photoelectric conversion element 34 is an element suitable for the long wavelength band of 1300 nm to 1600 nm used for communications, and is made of, for example, indium gallium arsenide, and elements with an open circuit voltage of 5 V or less and a conversion efficiency of approximately 30% are readily available. The wavelength λ0 is a wavelength at which the photoelectric conversion element 34 can perform photoelectric conversion efficiently. The power storage unit 35 is made of, for example, an electric double layer capacitor such as EDLC.

[0022] The communication line changeover switch 31 and the optical sensor 32 operate on power stored in a power storage unit 35, which is boosted to a drive voltage by a boost circuit 36. The electrical signal converted by the photoelectric conversion element 34 is also input to a control unit 37, which extracts control signals for the communication line changeover switch 31 and the optical sensor 32 that are superimposed on the light of wavelength λ0. The control unit 37 controls the operation of the communication line changeover switch 31 and the optical sensor 32 using the control signals.

[0023] The control unit 37 also collects data on the status of the optical line switching nodes 30 and data from the optical sensors 32. When transmitting the data to the monitoring and control device 50, the control unit 37 divides the data into the number of reflection switches (38-40). In FIG. 1, the number of reflection switches is three, but is not limited to this number. The number of reflection switches is one less than the number of lasers provided in the monitoring and control device 50.

[0024] The control unit 37 inputs the divided data to reflective switches (38-40) that reflect the light (light with wavelengths λ1 to λ3) from the lasers 3 to 5. The reflective switches (38-40) perform ON / OFF operation using the divided data to intensity-modulate the reflected light and return the reflected light to the monitoring and control device 50. In other words, data from the optical node 30 is transmitted in parallel to the monitoring and control device 50 using multiple wavelengths. Because the reflective switches (38-40) operate frequently, it is desirable that they operate at a low voltage and with very little power consumption of a few nW or less; for example, it is preferable to use electrostatically driven MEMS optical switches that require little drive power and are generally available.

[0025] The reflected light that has propagated through optical fiber 20 is input to WDM coupler 8 via optical circulator 7 and split into individual wavelengths. The reflected light of wavelength λ1 is received by optical receiver 9, the reflected light of wavelength λ2 by optical receiver 10, and the reflected light of wavelength λ3 by optical receiver 11. The optical receivers (9-11) pass the information contained in the received reflected light to the management section of controller 1. The management section of controller 1 combines this information to regenerate the original data (i.e., the data of optical node 30).

[0026] 2 is a diagram illustrating the flow until the data of the optical sensor 32 is reproduced by the controller 1. First, the controller 1 instructs the optical sensor 32 to read. Specifically, the modulation unit of the controller 1 modulates the laser light to the laser 2, and outputs a signal instructing the optical sensor 32 to read. In response to this signal, the control unit 37 issues a read instruction to the optical sensor 32.

[0027] The data read by the optical sensor 32 is stored (buffered) in the control unit 37 (step S01). Next, the control unit 37 divides the data into predetermined division sizes and assigns an identification number (ID) to each divided data (step S02). Next, based on the divided data, the corresponding optical reflective switches (38-40) modulate light (light with wavelengths λ1-λ3) from the lasers (3-5) and return an optical signal to the monitoring control device 50 (step S03). Next, the monitoring control device 50 receives the received divided data using optical receivers (9-11) corresponding to each wavelength, combines the divided data in ID order, and recovers the data read by the optical sensor 32 (step S04). Finally, if the combined data is not corrupted, the data reading by the optical sensor 32 is completed (step S05).

[0028] In this embodiment, an example using three reflection switches (38 to 40) is shown, but it goes without saying that if lasers and optical receivers with wavelengths corresponding to the number of reflection switches are prepared, upstream communication with improved communication speeds can be achieved using more reflection switches.

[0029] As described in the above embodiments, according to the optical node and the system using the same of the present invention, the downstream laser light supplied from the monitoring control device to the optical node can use multiple wavelengths, thereby making it possible to multi-wavelengthize the upstream light from the optical node and improve the upstream communication speed.

[0030] Furthermore, it goes without saying that this remote control system can be easily expanded by providing an optical selector on the monitor and control device side, thereby increasing the number of optical nodes provided in the system.

[0031] According to the present invention, in a system consisting of a monitoring and control device installed in a power supply environment and one or more optical nodes located remotely, it is possible to simultaneously realize optical power supply using multiple lasers, control of multiple modules included in the optical node, and upstream communication functions using multiple wavelengths, thereby improving communication speed. [Explanation of symbols]

[0032] 1: Controller 2~5: Laser 6: WDM coupler 7: Optical circulator 8: WDM coupler 9~11: Optical receiver 20: Optical fiber 30: Optical node 31: Communication line changeover switch 32: Optical sensor 33: WDM coupler 34: Photoelectric conversion element 35: Power storage unit 36: Boost circuit 37: Control unit 38~40: Reflection switch 50: Monitoring and control device 301: Remote control system

Claims

1. a wavelength division multiplexing (WDM) coupler that splits laser light of multiple wavelengths supplied via an optical fiber into individual wavelengths; a photoelectric conversion element that receives at least one of the laser beams branched for each wavelength and performs photoelectric conversion; a power storage unit that stores power from the photoelectric conversion element; a plurality of reflection switches, each of which is provided for each of the other laser beams branched into a plurality of wavelengths, and which switch between a reflection state and a non-reflection state for each of the other laser beams and return the reflected laser beam to the optical fiber via the WDM coupler; a control unit that divides the module information into drive signals corresponding to the number of the reflection switches and drives each of the reflection switches using the power of the power storage unit; An optical node comprising:

2. The optical node according to claim 1, characterized in that the control unit further drives the module using power from the power storage unit in accordance with a control signal contained in the laser light received by the photoelectric conversion element.

3. 3. The optical node according to claim 1, wherein the module is an optical sensor, a communication line changeover switch, or both.

4. an optical node according to any one of claims 1 to 3; a supervisory control device connected to the optical node by the optical fiber; A remote control system comprising: The monitoring and control device includes: a plurality of lasers each supplying laser light of a different wavelength to the optical fiber; a modulator that modulates the laser light of a wavelength received by the photoelectric conversion element with a control signal; a plurality of photodetectors, each of which corresponds in number to the number of the reflection switches, for receiving the other laser beams reflected by the reflection switches; a management unit that combines signals from the light receivers to reproduce information from the module; A remote control system comprising:

5. A method for remotely controlling an optical node, comprising: A wavelength division multiplexing (WDM) coupler is used to split laser light of multiple wavelengths supplied via an optical fiber into individual wavelengths. receiving at least one of the laser beams split into wavelengths with a photoelectric conversion element and performing photoelectric conversion; storing the power from the photoelectric conversion element in a power storage unit; Dividing the module information into a drive signal corresponding to the number of reflection switches, and driving each of the reflection switches using the power of the power storage unit; and By using the drive signal, the reflection switches provided for the other laser lights branched into a plurality of wavelengths are switched between a reflection state and a non-reflection state for each of the other laser lights, and the reflected laser lights are returned to the optical fiber via the WDM coupler. A remote control method comprising:

6. The remote control method according to claim 5, further comprising driving the module using the power of the power storage unit in accordance with a control signal included in the laser light received by the photoelectric conversion element.

7. 7. The remote control method according to claim 5, wherein the module is an optical sensor, a communication line changeover switch, or both.

8. In a monitoring and control device connected to the optical node by the optical fiber, supplying laser beams of different wavelengths to the optical fiber from a plurality of lasers; modulating the laser light of a wavelength received by the photoelectric conversion element with a control signal; receiving the other laser light reflected by the reflection switch with the same number of light receivers as the reflection switches; and combining the signals from each of the optical receivers to recover the information of the module; 8. The remote control method according to claim 5, further comprising:

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