Remote optical path switching node and remote optical path switching method

Abstract

This remote optical path switching node 10, which is disposed at a connection point of optical fibers, comprises: an optical switch unit 11 that switches the connection of core wires of optical fibers connected to ports; a photoelectric conversion element 13 that photoelectrically converts feed light into electrical energy; a capacitor 14 for optical power feeding that stores the electrical energy which has been photoelectrically converted by the photoelectric conversion element 13; a capacitor 15 for manhole power generation that stores electrical energy supplied from a power generation unit 30; and a remote control unit 16 that supplies electrical energy to the optical switch unit 11 from at least one among the capacitor 14 for optical power feeding and the capacitor 15 for manhole power generation, and controls the optical switch unit 11 to switch the connection of core wires between optical fibers.

Description

[Technical Field]

[0001] The present invention relates to a remote optical path switching node and a remote optical path switching method. [Background technology]

[0002] In access networks that connect exchanges and user-side communication terminals with optical fibers, optical path switching is performed at a certain frequency during installation and maintenance work. The method of having workers enter manholes, open the housings at connection points, and switch the optical fiber cores poses the problem of time-consuming work required to arrange for workers and to perform the optical path switching work.

[0003] Therefore, it is being considered to configure the access network with a multistage loop type wiring and a remote optical path switching node. A multistage loop type wiring is a configuration in which multiple loop wirings are connected in multiple stages. A remote optical path switching node is placed at the connection point between the upper and lower loops of the multistage loop type wiring, and the connection of the optical fiber core wires between the loops can be switched remotely from the accommodation station. By realizing remote optical path switching using a remote optical path switching node, it is possible to reduce the work time.

[0004] However, since the remote optical path switching node is expected to be installed inside a manhole, it is difficult to secure an external power source. Non-Patent Documents 1 and 2 propose a remote optical path switching node that performs photoelectric conversion on the power supply light sent from the exchange, stores the electrical energy in a capacitor, and drives each part of the remote optical path switching node with the electrical energy stored in the capacitor. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Tomohiro Kawano, Tatsuya Fujimoto, Kazuhide Nakae, Hiroshi Watanabe, Kazunori Katayama, "Study on remote optical path switching nodes for future optical access networks," 2021 Institute of Electronics, Information and Communication Engineers General Conference, B-13-16, 2021 [Non-patent document 2] Tomohiro Kawano, Tetsuya Manabe, Akihiro Kuroda, Kazuhide Nakae, Hiroshi Watanabe, Kazunori Katayama, "A Study on Serial Connection Method of Remote Optical Path Switching Nodes," 2022 IEICE General Conference, B-13-28, 2022 Summary of the Invention [Problem to be solved by the invention]

[0006] The remote optical path switching nodes in Non-Patent Documents 1 and 2 have a problem in that, due to system trouble or the like, it may not be possible to charge the capacitor with the power supply light via the optical power supply fiber, and each part of the remote optical path switching node may not be able to be driven.

[0007] The present invention has been made in view of the above, and has as its object to operate a remote optical path switching node more stably. [Means for solving the problem]

[0008] A remote optical path switching node according to one aspect of the present invention is a remote optical path switching node disposed at a connection point of optical fibers, and includes an optical switch unit that switches the connection of the core wires of the optical fibers connected to a port, a photoelectric conversion element that photoelectrically converts power supply light into electrical energy, a first capacitor that stores the electrical energy, a second capacitor that stores electrical energy supplied from an external power generation device, and a remote control unit that supplies electrical energy from at least one of the first capacitor and the second capacitor to the optical switch unit and controls the optical switch unit to switch the connection of the core wires between the optical fibers. The remote optical path switching node is placed inside a manhole, and the power generation device is a solar panel placed on the manhole cover, a thermoelectric element placed on the manhole cover, or a device that generates power by utilizing the vibration of the manhole cover.

[0009] A remote optical path switching method according to one aspect of the present invention is a remote optical path switching method executed by a remote optical path switching node disposed at a connection point of optical fibers, the remote optical path switching node comprising a first capacitor for storing electrical energy obtained by photoelectric conversion of power supply light, and a second capacitor for storing electrical energy supplied from an external power generation device, and when the electrical energy of the first capacitor cannot be used, the remote optical path switching node checks the amount of electrical energy stored in the second capacitor, and when the amount of stored electrical energy is equal to or greater than a threshold, switches the connection of the core wires of the optical fiber by using the electrical energy of the second capacitor. The remote optical path switching node is placed inside a manhole, and the power generation device is a solar panel placed on the manhole cover, a thermoelectric element placed on the manhole cover, or a device that generates power by utilizing the vibration of the manhole cover. [Effects of the Invention]

[0010] According to the present invention, it is possible to operate a remote optical path switching node more stably. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a remote optical path switching node. [Figure 2] FIG. 2 is a flowchart showing an example of the flow of a power supply process when switching an optical path. [Figure 3] FIG. 3 is a flowchart showing an example of the flow of a power supply process when switching an optical path. [Figure 4] FIG. 4 is a diagram showing an example of a network configuration using multistage loop wiring. [Figure 5] FIG. 5 is a diagram illustrating an example of an optical path switching procedure. [Figure 6] FIG. 6 is a diagram illustrating an example of an optical path switching procedure. [Figure 7] FIG. 7 is a diagram illustrating an example of the configuration of a remote optical path switching node. DETAILED DESCRIPTION OF THE INVENTION

[0012] An example of the configuration of a remote optical path switching node 10 of this embodiment will be described with reference to Fig. 1. The remote optical path switching node 10 is a device that is placed, for example, in a manhole at a connection point between loops of a multistage loop-type wiring, and switches the connection of optical fiber core wires between the loops. The remote optical path switching node 10 operates by using electrical energy obtained by photoelectric conversion of power supply light sent from a storage station, as well as electrical energy obtained by a power generation unit 30 installed in a manhole cover.

[0013] The remote optical path switching node 10 shown in Figure 1 includes an optical switch unit 11, a port monitoring unit 12, an optoelectronic conversion element 13, an optical power supply capacitor 14 (first capacitor), a manhole power generation capacitor 15 (second capacitor), and a remote control unit 16.

[0014] The optical fiber cores of each loop are connected to the optical switch unit 11 via the port monitoring unit 12. The optical fiber cores are connected to ports provided in the remote optical path switching node 10. The optical switch unit 11 switches the connection of the optical fiber cores between each loop in response to instructions from the exchange. Specifically, the optical switch unit 11 connects ports by physically moving components within the optical switch unit 11 so that light entering from a port is emitted to the destination port. By connecting ports with the optical switch unit 11, the optical fiber cores between the loops are connected, and an optical path is established.

[0015] The port monitor 12 measures the optical power of the optical fiber core at each port to which the optical fiber core is connected, and determines the connections between the ports. Then, the port monitor 12 generates connection information indicating the connections between the determined ports.

[0016] When switching the optical path, the optical switch unit 11 and the port monitor unit 12 are powered by at least one of the optical power supply capacitor 14 and the manhole power generation capacitor 15 to operate.

[0017] An optical fiber that transmits the power supply light and control light sent from the accommodating station is connected to the photoelectric conversion element 13. The photoelectric conversion element 13 receives the power supply light sent from the accommodating station, photoelectrically converts the optical energy of the power supply light into electrical energy, and stores the electrical energy in the optical power supply capacitor 14. In addition, another photoelectric conversion element (not shown) receives the control light sent from the accommodating station, converts the control light into an electrical signal, and transmits it to the remote control unit 16, thereby notifying the remote control unit 16 of remote instructions from the accommodating station.

[0018] The optical power supply capacitor 14 stores the electrical energy converted from the power supply light, and drives the optical switch unit 11, the port monitor unit 12, and the remote control unit 16 with the stored electrical energy.

[0019] The manhole power generation capacitor 15 is connected to the power generation unit 30 via electrical wiring. The manhole power generation capacitor 15 stores the electrical energy generated by the power generation unit 30 and drives the optical switch unit 11, the port monitoring unit 12, and the remote control unit 16 with the stored electrical energy.

[0020] The remote control unit 16 is a control unit that controls the remote optical path switching node 10 based on remote instructions using control light sent from the accommodating station. For example, the remote control unit 16 controls the optical switch unit 11 to connect the core wires between the loops, and sends connection information between the core optical fiber wires obtained by the port monitoring unit 12 to the accommodating station. The remote control unit 16 also monitors the amount of electricity stored in the optical power feeding capacitor 14 and the manhole power generation capacitor 15, and controls the power supply from the optical power feeding capacitor 14 and the manhole power generation capacitor 15 to the optical switch unit 11 and the port monitoring unit 12. A microprocessing unit (MPU) equipped with a processor can be used for the remote control unit 16.

[0021] The power generation unit 30 is a device that is installed on, for example, a manhole cover and generates electricity using renewable energy such as sunlight, heat, vibration, etc. Examples 1-3 of the power generation unit 30 installed on a manhole cover will be described below.

[0022] In the first embodiment, the power generation unit 30 generates electricity by utilizing solar light energy. A solar panel is installed on the top of the manhole cover as the power generation unit 30, and electricity generated by absorbing solar light energy and photoelectric conversion is stored in the manhole power generation capacitor 15 via electrical wiring. The size of the solar panel is equivalent to the size of a manhole cover (0.6 m). 2 ), even if the power conversion efficiency of solar power generation is taken into account as 20%, a power of several hundred watts can be obtained, which is sufficient to operate the remote optical path switching node 10. The surface of the solar panel may be covered with a material that has excellent pressure resistance and impact resistance.

[0023] In the second embodiment, the power generation unit 30 generates electricity using solar thermal energy. A thermoelectric element is installed on the manhole cover as the power generation unit 30, and electricity generated by the thermoelectric effect utilizing the temperature difference between the upper side of the manhole cover (outside the manhole) and the lower side of the manhole cover (inside the manhole) is stored in the manhole power generation capacitor 15 via electrical wiring. If a typical thermoelectric element generates electricity equivalent to the size of the manhole cover, several watts of power can be obtained even considering that the power conversion efficiency of the thermoelectric element is 5%, so that sufficient power can be secured to operate the remote optical path switching node 10. The surface of the thermoelectric element may be covered with a material that has excellent pressure and impact resistance.

[0024] Example 3 is an example of generating electricity using energy from vibrations. A vibration power generation mechanism that utilizes vibrations transmitted to the manhole cover due to, for example, a vehicle traveling and generates electricity through effects such as electromagnetic induction, electrostatic induction, inverse magnetostriction effect, or piezoelectric effect is installed on the manhole cover as power generation unit 30. The vibration power generation mechanism need not be installed on the manhole cover, but may be installed in any location inside or around the manhole where vibrations are likely to occur.

[0025] In any of Examples 1 to 3, it is preferable to configure the manhole so that the electrical wiring does not interfere (be pulled, etc.) when the manhole cover is opened.

[0026] Next, an example of power supply processing when the electrical energy of the optical power supply capacitor 14 cannot be used will be described with reference to the flowchart in Fig. 2. When power cannot be stored in the optical power supply capacitor 14 due to a system trouble, power is supplied from the manhole power generation capacitor 15 according to the flowchart in Fig. 2.

[0027] Specifically, in step S11, the remote control unit 16 checks the amount of electricity stored in the manhole power generation capacitor 15.

[0028] In step S12, the remote control unit 16 determines whether the amount of electricity stored in the manhole power generation capacitor 15 is sufficient.

[0029] If the stored power amount is sufficient, the remote control unit 16 supplies power from the manhole power generation capacitor 15 to the optical switch unit 11 and the port monitor unit 12 in step S13.

[0030] If the amount of stored electricity is insufficient, the remote control unit 16 waits for electricity to be stored in the manhole power generation capacitor 15.

[0031] By the above process, even when the electrical energy of the optical power supply capacitor 14 cannot be used, the manhole power generation capacitor 15 can be used to switch the optical path.

[0032] Next, an example of a power supply process that gives priority to using the electrical energy of the manhole power generation capacitor 15 will be described with reference to the flowchart of FIG.

[0033] In step S21, the remote control unit 16 checks the amount of electricity stored in the manhole power generation capacitor 15.

[0034] In step S22, the remote control unit 16 determines whether the amount of electricity stored in the manhole power generation capacitor 15 has reached a level at which the optical switch unit 11 and the port monitor unit 12 can operate.

[0035] If the stored power amount is sufficient, the remote control unit 16 supplies power from the manhole power generation capacitor 15 to the optical switch unit 11 and the port monitor unit 12 in step S23.

[0036] If the amount of stored power is insufficient, the remote control unit 16 feeds power from the optical power feeding capacitor 14 to the optical switch unit 11 and the port monitor unit 12 in step S24.

[0037] It is also possible to supply power to the optical switch unit 11 and the port monitor unit 12 through both the optical power supply capacitor 14 and the manhole power generation capacitor 15 .

[0038] Next, a multi-stage loop type wiring network will be described with reference to FIG.

[0039] In a multistage loop-type wiring, one or more lower loops 200 are connected to an upper loop 100 connected to an accommodation station 300. A remote optical path switching node 10 is placed at the connection point between the upper loop 100 and the lower loop 200. The upper loop 100 and the lower loop 200 are composed of optical fiber having multiple cores. By connecting the optical fiber core of the upper loop 100 to the optical fiber core of the lower loop 200 at the remote optical path switching node 10, an optical path is established between a communication device on the lower loop 200 and a communication device in the accommodation station. It is also possible to connect optical paths between communication devices on different lower loops 200 via the upper loop 100. The upper loop 100 is equipped with an optical fiber that supplies power supply light to each remote optical path switching node 10. This optical fiber can also be used to transmit control light.

[0040] Next, the optical path switching procedure will be described with reference to Figures 5 and 6. In the example of Figures 5 and 6, an optical path is connected between the accommodation station 300 and the communication device 210 on the lower loop 200. The communication device 210 is, for example, a wireless base station. The optical fiber cores of the upper loop 100 are connected to ports 1 and 2 of the remote optical path switching node 10, and the optical fiber cores of the lower loop 200 are connected to ports 3 and 4 of the remote optical path switching node 10.

[0041] First, as shown in Fig. 5, the accommodation station 300 transmits control light to the remote optical path switching node 10 to instruct it to connect port 1 and port 3. Upon receiving the instruction, the remote optical path switching node 10 controls the optical switch unit 11 to connect port 1 and port 3. When port 1 and port 3 of the remote optical path switching node 10 are connected, an optical path is established between the accommodation station and the communication device 210 via port 1 and port 3, as shown in Fig. 6.

[0042] After the optical path switching at the remote optical path switching node 10 is completed, the accommodation station 300 transmits control light to the remote optical path switching node 10 to instruct it to acquire connection information.

[0043] The remote optical path switching node 10 controls the port monitor 12 to check the connection between port 1 and port 3 and returns the connection information to the accommodating station 300. The connection information may be checked by an optical test. For example, the control light transmitted from the accommodating station 300 is used to return the connection information to the accommodating station 300, and the control light is superimposed with the connection information before transmission.

[0044] When the accommodating station 300 confirms the connection information, it starts using the optical path between itself and the communication device 210 .

[0045] By using a multistage loop-type wiring and a remote optical path switching node, it is possible to easily switch optical paths if a failure occurs after use has begun. For example, if a failure occurs between port 3 and the communication device 210, the accommodation station 300 sends control light to the remote optical path switching node 10, instructing it to connect ports 1 and 4. Upon receiving the control light, the remote optical path switching node 10 connects ports 1 and 4. This connects an optical path between the accommodation station and the communication device 210 via ports 1 and 4.

[0046] Next, an embodiment of a remote optical path switching node will be described with reference to Fig. 7. The remote optical path switching node 10 in Fig. 7 has a configuration in which a manhole power generation capacitor 15 is added to the remote optical path switching node of Non-Patent Document 2. In Fig. 7, power lines that supply power to each part are shown with solid lines, and optical fibers are shown with dashed lines. Components that have the same functions as each part of the remote optical path switching node 10 in Fig. 1 are assigned the same reference numerals.

[0047] The optical fiber of each loop is connected to the optical switch unit 11 via the port monitor unit 12 .

[0048] The optical fiber transmitting the power supply light and control light is connected to the photoelectric conversion element 13, the optical receiving unit 17, and the MEMS (Micro Electro Mechanical Systems) switch 19. The power supply light is incident on the photoelectric conversion element 13, and the control light is incident on the optical receiving unit 17 and the MEMS switch 19. The power supply light is photoelectrically converted by the photoelectric conversion element 13, and electrical energy is stored in optical power supply capacitors 14A and 14B (first capacitors). The remote optical path switching node 10 in FIG. 7 has two optical power supply capacitor systems: the optical power supply capacitor 14A supplies power to the optical switch unit 11 and port monitoring unit 12, and the optical power supply capacitor 14B supplies power to the remote control unit 16. If the manhole power generation capacitor 15 is also added, the remote optical path switching node 10 in FIG. 7 has three power sources.

[0049] The control light is received by the optical receiving unit 17, converted into an electrical signal, and transmitted to the remote control unit 16. The remote control unit 16 operates the remote optical path switching node 10 in accordance with the control light converted into an electrical signal.

[0050] The MEMS switch 19 is used to transmit data from the remote optical path switching node 10 to the accommodation station. The remote control unit 16 controls the reflection of the control light by switching the MEMS switch 19 on and off, and superimposes the information to be transmitted onto the control light.

[0051] The power lines connect the capacitors 14A, 14B, and 15 to each component of the remote optical path switching node 10, and supply power from the capacitors 14A, 14B, and 15 to each component. Load switches (LSWs) are arranged on the power lines. The remote control unit 16 controls the LSWs to control the power supply to each component. For example, when switching the optical path, the remote control unit 16 turns on the LSW connected to the optical switch unit 11 to supply power to the optical switch unit 11.

[0052] The power generation unit 30 placed on the manhole cover and the manhole power generation capacitor 15 are connected by a power line, and the power generated by the power generation unit 30 is stored in the manhole power generation capacitor 15. The amount of electricity stored in the manhole power generation capacitor 15 is monitored by the remote control unit 16. When sufficient power has been stored in the manhole power generation capacitor 15, the remote control unit 16 turns on the LSW connected to the manhole power generation capacitor 15, connects the manhole power generation capacitor 15 to the boost element 18, and supplies power from the manhole power generation capacitor 15 to each unit.

[0053] As described above, the remote optical path switching node 10 disposed at the connection point of the optical fibers of this embodiment includes the optical switch unit 11 that switches the connection of the optical fiber core wires connected to the port, the photoelectric conversion element 13 that photoelectrically converts the power supply light into electrical energy, the optical power supply capacitor 14 that stores the electrical energy photoelectrically converted by the photoelectric conversion element 13, the manhole power generation capacitor 15 that stores electrical energy supplied from the power generation unit 30, and the remote control unit 16 that supplies electrical energy to the optical switch unit 11 from at least one of the optical power supply capacitor 14 and the manhole power generation capacitor 15 and controls the optical switch unit 11 to switch the connection of the optical fiber core wires. This allows power to be supplied to the optical switch unit 11 from the manhole power generation capacitor 15 even if the electrical energy of the optical power supply capacitor 14 is unavailable due to a system trouble. As a result, the remote optical path switching node 10 can operate more stably. [Explanation of symbols]

[0054] 10 Remote Optical Path Switching Node 11 Optical switch section 12 Port Monitoring Unit 13 Photoelectric conversion element 14, 14A, 14B Optical power supply capacitor (first capacitor) 15 Manhole power generation capacitor (second capacitor) 16 Remote control unit 17 Optical receiver 18 Boost element 19 MEMS switches 30 Power Generation Department

Claims

1. A remote optical path switching node disposed at a connection point of an optical fiber, an optical switch unit for switching the connection of optical fiber cores connected to the port; a photoelectric conversion element that photoelectrically converts the power supply light into electrical energy; a first capacitor for storing the electrical energy; a second capacitor for storing electrical energy supplied from an external power generating device; a remote control unit that supplies electrical energy from at least one of the first capacitor and the second capacitor to the optical switch unit and controls the optical switch unit to switch the connection of the core wires between the optical fibers; the remote optical path switching node is disposed in a manhole; The power generation device is a solar panel placed on the manhole cover, a thermoelectric element placed on the manhole cover, or a device that generates power by utilizing the vibration of the manhole cover. Remote optical path switching node.

2. 2. The remote optical path switching node according to claim 1, a port monitoring unit that monitors connections between the ports, The remote control unit transmits connection information indicating the connection between the ports. Remote optical path switching node.

3. A remote optical path switching method executed by a remote optical path switching node disposed at a connection point of an optical fiber, comprising: the remote optical path switching node includes a first capacitor for storing electrical energy obtained by photoelectric conversion of power supply light, and a second capacitor for storing electrical energy supplied from an external power generating device; The remote optical path switching node When the electric energy of the first capacitor cannot be utilized, the amount of electric energy stored in the second capacitor is confirmed; When the amount of stored electricity is equal to or greater than a threshold, the electrical energy of the second capacitor is used to switch the connection of the core wire of the optical fiber; the remote optical path switching node is located in a manhole; The power generation device is a solar panel placed on the manhole cover, a thermoelectric element placed on the manhole cover, or a device that generates power by utilizing the vibration of the manhole cover. Remote optical path switching method.

Images