Optical communication device and sleep control method

Abstract

An optical communication device including: a control signal generation unit that on the basis of a communication log including information indicating whether communication has succeeded in a wake mode of a power-receiving optical communication device driven by electricity obtained from a power-supply optical signal, generates a wake signal including one or more sets of time information indicating time at which radio communication between the power-receiving optical communication device and a terminal device is supposed to succeed; and an optical communication unit that converts the generated wake signal into an optical signal and transmits the optical signal to the power-receiving optical communication device.　

Description

[Technical field]

[0001] The present invention relates to an optical communication device and a sleep control method. [Background technology]

[0002] Conventionally, optical communication devices are known that charge a battery with power obtained through optical power supply and operate using the charged power. Since such optical communication devices have limited available power, they can reduce power consumption by going into sleep mode when no signal is being transmitted. However, in many LPWA (Low Power Wide Area) standards such as class A and enocean of LoRaWAN (Long Range Wide Area Network) (LoRa is a registered trademark), a signal arrives from a terminal device without a preamble (see, for example, Non-Patent Document 1). Therefore, it is difficult to wake up the sleep mode of the optical communication device in response to the arrival of a signal.

[0003] Therefore, conventional optical communication devices performing LPWA communication are constantly on standby for signals by being powered by a power source, etc. However, optical communication devices that are powered by optical power supply, etc., cannot operate constantly because their power is limited. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] “Commercialization of LoRaWAN for IoT Business Expansion”, NTT Technical Journal, [online], [Retrieved September 6, 2021], Internet < https: / / journal.ntt.co.jp / article / 5426> Summary of the Invention [Problem to be solved by the invention]

[0005] There are two possible methods for receiving upstream signals in LPWA communications while operating in a power-saving manner by charging the battery in optical communications equipment using power obtained from optical power supply or the like without using commercial power. The first method refers to the remaining charge of the optical communications equipment and starts it up only when possible. With the first method, it is possible to reduce the power consumption of the optical communications equipment, but since it starts up regardless of the arrival of a signal, the success rate of receiving signals may be low.

[0006] The second method is to use foresight information such as the transmission cycle of the terminal device that transmits the uplink signal. In the second method, the optical communication device acquires information on the transmission cycle of the terminal device as foresight information in some way, and stores the information on the transmission cycle as a terminal transmission cycle table. The optical communication device then refers to the terminal transmission cycle table and starts up in response to the arrival of a signal transmitted from the terminal device by transitioning between a sleep state and an awake state. In the second method, the signal reception success rate is high, but it is difficult to obtain foresight information.

[0007] As described above, conventionally, there has been a problem in that it is not possible to improve the success rate of receiving an upstream signal while saving power in an optical communication device that communicates with a terminal device that transmits an upstream signal.

[0008] In view of the above circumstances, an object of the present invention is to provide a technology that can improve the success rate of receiving an upstream signal while saving power in an optical communication device that communicates with a terminal device that transmits an upstream signal. [Means for solving the problem]

[0009] One aspect of the present invention is an optical communication device that includes a control signal generating unit that generates a sleep wake-up signal including one or more time information indicating that communication between a power receiving optical communication device powered by power obtained from an optical signal for power supply and a terminal device performing wireless communication is estimated to be successful based on a communication log including information on the success or failure of communication when the sleep state of the power receiving optical communication device is woken up, and an optical communication unit that converts the generated sleep wake-up signal into an optical signal and transmits it to the power receiving optical communication device.

[0010] One aspect of the present invention is a sleep control method that generates a sleep wake-up signal including one or more time information indicating that communication between a power-receiving optical communication device powered by power obtained from an optical signal for power supply and a terminal device performing wireless communication is estimated to be successful based on a communication log including information on the success or failure of communication when the sleep state of the power-receiving optical communication device is released, and converts the generated sleep wake-up signal into an optical signal and transmits it to the power-receiving optical communication device. Effect of the Invention

[0011] According to the present invention, it is possible to improve the success rate of receiving an upstream signal while saving power in an optical communication device that communicates with a terminal device that transmits an upstream signal. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a diagram illustrating a configuration example of an optical power supply system according to an embodiment. [Diagram 2] FIG. 2 is a diagram illustrating a specific configuration of an OLT in an embodiment. [Diagram 3] FIG. 2 is a diagram illustrating a specific configuration of an ONU in an embodiment. [Figure 4] FIG. 4 is a diagram illustrating an example of a communication log in the embodiment. [Diagram 5] FIG. 4 is a sequence diagram showing a processing flow of the optical power supply system according to the embodiment. [Figure 6] 11 is a flowchart showing the flow of a process for generating a sleep release signal performed by an OLT in the embodiment. [Figure 7] FIG. 13 is a diagram showing an example of an estimation result obtained from a trained model. [Figure 8] FIG. 13 is a diagram illustrating a relationship between an estimation result and a threshold value in the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing an example of the configuration of an optical power supply system 100 according to an embodiment. The optical power supply system 100 includes an OLT 10 and an ONU 20. The OLT 10 and the ONU 20 are connected via an optical transmission path 40. The OLT 10 and the ONU 20 are connected via the optical transmission path 40, thereby enabling communication between the OLT 10 and the ONU 20. For example, the OLT 10 and the ONU 20 are connected via a power supply line and a communication line, respectively.

[0014] The power supply line and the communication line may be provided in the same fiber physically, or may be provided in separate independent fibers. That is, the optical signal for communication and the optical signal for power supply may share the same fiber physically, or may use separate independent fibers. When the optical signal for communication and the optical signal for power supply share the same fiber, a method of wavelength multiplexing the light for communication and the light for power supply using different frequency bands is conceivable. In the following explanation, an example of a configuration in which the optical signal for communication and the optical signal for power supply use separate independent fibers is explained. In FIG. 1, the OLT 10 and the ONU 20 have a single-star topology. Hereinafter, the direction from the OLT 10 toward the ONU 20 is referred to as the downstream direction, and the direction from the ONU 20 toward the OLT 10 is referred to as the upstream direction.

[0015] 1 shows one ONU 20, the optical power supply system 100 may include multiple ONUs 20. When multiple ONUs 20 are included in the optical power supply system 100, an optical splitter is provided between the OLT 10 and the multiple ONUs 20. The optical splitter splits the optical signal transmitted from the OLT 10 and transmits it to each ONU 20. The optical splitter multiplexes the optical signals transmitted from each ONU 20 and transmits it to the OLT 10.

[0016] One or more wireless terminals 30 (wireless terminals 30-1 and 30-2 in FIG. 1) are connected to the ONU 20. The ONU 20 and each wireless terminal 30 communicate with each other via LPWA. The wireless terminals 30 are, for example, IoT (Internet of Things) terminals such as sensors. Each wireless terminal 30 transmits a signal when a pre-set condition is satisfied. The condition may be, for example, the time, the day of the week, the amount of accumulated data, or the operation of a sensor attached to the terminal. That is, depending on the pre-set conditions, the wireless terminals 30-1 and 30-2 transmit signals to the ONU 20 at different times.

[0017] The OLT 10 is an optical communication device that supplies power for the operation of the ONU 20. In order to operate the ONU 20 in a power-saving manner, the OLT 10 causes the ONU 20 to wake up from sleep at a timing when it is estimated that communication between the ONU 20 and the wireless terminal 30 will be successful. For example, the OLT 10 transmits to the ONU 20 a sleep wake-up signal that includes information on one or more times when communication is estimated to be successful. The sleep wake-up signal is a signal for waking up some of the functional units of the ONU 20 from a sleep state.

[0018] In order to estimate the timing when communication is estimated to be successful, the OLT 10 learns the arrival timing of a signal from the wireless terminal 30 by machine learning. Here, learning refers to optimizing the coefficients used in the machine learning model. For example, learning refers to adjusting the coefficients used in the machine learning model so that the loss function is minimized. The coefficients used in the machine learning model are, for example, weight values ​​and bias values. In the initial stage of learning (for example, the initial generation stage of a trained model), the OLT 10 releases the sleep state of the ONU 20 at a random time and collects a communication log between the ONU 20 and the wireless terminal 30 obtained by the ONU 20 at the time of release from sleep.

[0019] The communication log is a log related to the communication between the ONU 20 and the wireless terminal 30 when the sleep state is released, and includes, for example, time information when the sleep state is released (release time information), information on whether the communication was successful, and information on the SSID (Service Set Identifier) ​​of the wireless terminal 30 when the communication was successful. The information on whether the communication was successful is information indicating whether the communication between the ONU 20 and the wireless terminal 30 was successful or unsuccessful. Successful communication between the ONU 20 and the wireless terminal 30 means that the ONU 20 has received a signal transmitted from the wireless terminal 30. Unsuccessful communication between the ONU 20 and the wireless terminal 30 means that the ONU 20 has not received a signal transmitted from the wireless terminal 30.

[0020] The OLT 10 uses the collected communication logs and the above-mentioned machine learning to learn at what timing the ONU 20 should be woken up from sleep to increase the probability of successful communication, and wakes up the ONU 20 from sleep mode at a timing when it is estimated that communication will be successful. Note that the timing when it is estimated that communication will be successful is a timing when there is a high probability that a signal transmitted from the wireless terminal 30 will arrive at the ONU 20.

[0021] The ONU20 is powered by the power supplied from the OLT10. In order to operate in a power-saving manner, the ONU20 operates in a sleep state except at the timing instructed by the OLT10. For example, the ONU20 transitions from a sleep state to an operable state at the time indicated by the time information included in the sleep release signal transmitted to the OLT10. The ONU20 records a communication log at the time when it transitions from a sleep state to an operable state (when the sleep state is released), and transmits the recorded communication log to the OLT10.

[0022] 2 is a diagram showing a specific configuration of the OLT 10 in the embodiment. The OLT 10 includes an optical power supply unit 11, a data transmission / reception unit 12, a control unit 13, a log storage unit 14, a learning unit 15, a learned model storage unit 16, a setting value storage unit 17, and a control signal generation unit 18.

[0023] The optical power supply unit 11 includes a light source that emits power supply light inside, generates the power supply light using the light source, and sends it to the optical transmission path 40. In this way, the optical power supply unit 11 transmits the power supply light to the ONU 20. As the power supply light, for example, an optical signal with a constant voltage that does not change over time is used.

[0024] The data transmitter / receiver 12 transmits and receives data to and from the ONU 20. The data transmitter / receiver 12 includes, for example, an optical transceiver, and includes a light source that emits light of a specific wavelength inside. The data transmitter / receiver 12 converts the light emitted from the light source included inside into an optical signal of transmission data (hereinafter referred to as "communication light") by modulating the light based on an electrical signal of a sleep release signal generated by the control signal generator 18, and sends the converted communication light to the optical transmission path 40.

[0025] The data transmitter / receiver 12 further includes an O / E (Optical / Electrical) converter such as a photodetector therein. The data transmitter / receiver 12 receives an optical signal of a communication log received via the optical transmission path 40, converts the received optical signal of the communication log into an electrical signal by the O / E converter, and outputs the electrical signal to the control unit 13.

[0026] The control unit 13 controls the operation of each functional unit included in the OLT 10. For example, the control unit 13 causes the optical power supply unit 11 to output power supply light. For example, the control unit 13 controls the control signal generation unit 18 to generate a sleep release signal.

[0027] The log storage unit 14 stores a communication log transmitted from the ONU 20. The log storage unit 14 is configured using a storage device such as a magnetic storage device or a semiconductor storage device.

[0028] The learning unit 15 inputs period information on the period to be estimated for waking up from sleep (hereinafter referred to as the "estimated target period") based on the communication log stored in the log storage unit 14, and generates a trained model that has been trained to output an estimated result of the reception success rate of the ONU 20 at each time indicated by the input period information. Specifically, the learning unit 15 generates a trained model using the time information at the time of waking up from sleep mode as learning data, and the SSID of the wireless terminal 30 and information on the success or failure of communication as teacher data. The estimated target period is preset in the form of "estimate at 1-second intervals from the current time until 5 seconds from now."

[0029] The learning algorithm used in the learning unit 15 is a supervised learning model, such as a neural network or deep learning. Note that the learning algorithm may be, for example, reinforcement learning or a classical machine learning method (linear regression, logistic regression, support vector machine, decision tree, random forest, naive Bayes, etc.).

[0030] The trained model storage unit 16 stores the trained model generated by the learning unit 15. The trained model storage unit 16 is configured using a storage device such as a magnetic storage device or a semiconductor storage device.

[0031] The set value storage unit 17 stores a threshold value used when the control signal generation unit 18 generates a sleep release signal, and information on the amount of power consumed in one sleep release in the ONU 20 (hereinafter referred to as "power consumption information") The set value storage unit 17 is configured using a storage device such as a magnetic storage device or a semiconductor storage device.

[0032] Based on the communication log, the control signal generating unit 18 generates a sleep release signal including one or more pieces of time information when communication between the ONU 20 and the wireless terminal 30 is estimated to be successful. More specifically, the control signal generating unit 18 generates the sleep release signal based on the trained model stored in the trained model storage unit 16, the threshold value and power consumption information stored in the set value storage unit 17, information on the remaining battery capacity of the ONU 20, and the estimated target period.

[0033] 3 is a diagram showing a specific configuration of the ONU 20 in the embodiment. The ONU 20 includes a light receiving unit 22, a power storage unit 23, a transmission / reception unit 24, a sleep control unit 25, a communication control unit 26, a log storage unit 27, an LPWA chip 28, and an antenna 29. The communication control unit 26 and the LPWA chip 28 are in a sleep state when not in use.

[0034] The light receiving unit 22 receives the optical signal transmitted from the optical power supply unit 11 via the optical transmission path 40, converts the received optical signal into an electrical signal, and outputs it to the power storage unit 23. The light receiving unit 22 is, for example, an O / E converter such as a photodetector.

[0035] The power storage unit 23 includes a battery therein. The power storage unit 23 stores the power of the electric signal in the battery by performing a charging process based on the electric signal output from the light receiving unit 22. In response to an instruction from the sleep control unit 25, the power storage unit 23 supplies a power supply voltage generated using the stored power to the communication control unit 26 and the LPWA chip 28. This causes the communication control unit 26 and the LPWA chip 28 to switch from a sleep state to an operable state.

[0036] The transmitting / receiving unit 24 transmits and receives data to and from the OLT 10. The transmitting / receiving unit 24 includes, for example, an optical transceiver, and includes a light source that emits light of a specific wavelength inside. The transmitting / receiving unit 24 converts the light emitted by the light source included inside into communication light by modulating the light based on the electrical signal of the communication log output from the communication control unit 26, and sends the converted communication light to the optical transmission path 40.

[0037] The transceiver 24 further includes an O / E converter such as a photodetector therein. The transceiver 24 receives the optical signal of the sleep release signal received via the optical transmission path 40, converts the received optical signal of the sleep release signal into an electrical signal by the O / E converter, and outputs the electrical signal to the sleep control unit 25.

[0038] The sleep control unit 25 controls the functional units in the sleep state to be in the active state in response to the sleep release signal received by the transmission / reception unit 24. Specifically, the sleep control unit 25 controls the functional units in the sleep state to be in the active state at the timing when the time included in the sleep release signal arrives.

[0039] The communication control unit 26 is a functional unit that can operate with power supplied from the power storage unit 23. Therefore, the communication control unit 26 goes into a sleep state when power is not being supplied from the power storage unit 23. The communication control unit 26 goes from the sleep state to an active state when power is being supplied from the power storage unit 23. The communication control unit 26 processes a signal received by the transceiver unit 24 and a signal received by the antenna 29 and input to the LPWA chip 28.

[0040] For example, the communication control unit 26 acquires a communication log based on a signal received by the antenna 29 and input to the LPWA chip 28. The communication control unit 26 stores the acquired communication log in the log storage unit 27. For example, the communication control unit 26 transmits the communication log stored in the log storage unit 27 to the OLT 10 via the transmission / reception unit 24.

[0041] The log storage unit 27 stores the communication log acquired by the communication control unit 26. The log storage unit 27 is configured using a storage device such as a magnetic storage device or a semiconductor storage device.

[0042] The LPWA chip 28 is a functional unit that can operate with power supplied from the power storage unit 23. Therefore, the LPWA chip 28 goes into a sleep state when power is not being supplied from the power storage unit 23. The LPWA chip 28 goes from the sleep state to an active state when power is supplied from the power storage unit 23. The LPWA chip 28 communicates with the wireless terminal 30 by the LPWN via the antenna 29.

[0043] Next, an example of learning by the learning unit 15 will be described with reference to FIG. 4. It is assumed that the communication log shown in FIG. 4 is stored in the log storage unit 14. FIG. 4 is a diagram showing an example of a communication log in the embodiment. In FIG. 4, the sleep wake-up time, the success or failure of reception, and each value of the SSID are registered in association with each other as the communication log. The sleep wake-up time indicates the time when the ONU 20 wakes up from the sleep state. The success or failure of reception indicates whether reception was successful or not when the sleep state of the ONU 20 is woken up (operable state). The value of the SSID indicates the identification name of the network to which the wireless terminal 30 is connected. Note that if communication fails, the ONU 20 cannot obtain information on the SSID. Therefore, if communication fails, a preset value (Y0 in FIG. 4) that means communication failure is used instead of the SSID of the wireless terminal 30 when communication is successful.

[0044] 4 shows that communication was successful at 0:00:00 and that the acquired SSID was Y1. On the other hand, it shows that communication failed at 0:00:01 and that the value of Y0 was set because the SSID could not be acquired. The learning unit 15 uses the communication log shown in FIG. 4 to learn the correspondence between the learning data and the teacher data, such as, for example, that data reception from the SSID of Y1 was successful at the time of X1 and that data reception was unsuccessful at the time of X2.

[0045] Fig. 5 is a sequence diagram showing a flow of processing of the optical power supply system 100 in the embodiment. Note that Fig. 5 describes a flow of generating a trained model in an initial stage. Note that, at the start of the processing in Fig. 5, it is assumed that no trained model is stored in the OLT 10.

[0046] The communication control unit 26 of the ONU 20 assigns the initial value "0" to the counters m and n (step S101). Here, the counters m and n represent the number of communication logs stored in the log storage unit 27. For example, the counter m represents the number of communication logs representing successful communication (reception success or failure is "success"), and the counter n represents the number of communication logs representing unsuccessful communication (reception success or failure is "failure").

[0047] The control unit 13 instructs the control signal generating unit 18 to generate a sleep release signal. Since this is an initial stage, for example, the control unit 13 instructs the control signal generating unit 18 to perform sleep release randomly. The control signal generating unit 18 generates a sleep release signal in accordance with the instruction of the control unit 13 (step S102). For example, the control signal generating unit 18 generates a sleep release signal including information on multiple times randomly selected from times from the current time forward. The control signal generating unit 18 outputs the generated sleep release signal to the data transmitting / receiving unit 12.

[0048] The data transmitter / receiver 12 uses the sleep release signal output from the control signal generator 18 to convert it into an optical signal, and transmits the optical signal to the ONU 20 via the optical transmission path 40 . The transceiver 24 of the ONU 20 receives the optical signal transmitted from the OLT 10. The transceiver 24 converts the received optical signal into an electrical sleep release signal. The transceiver 24 outputs the sleep release signal to the sleep controller 25. When the time included in the sleep release signal arrives, the sleep controller 25 controls the power storage unit 23 to release the sleep state of the communication controller 26 and the LPWA chip 28 (step S104).

[0049] When the sleep state of the communication control unit 26 and the LPWA chip 28 is released, wireless communication between the ONU 20 and the wireless terminal 30 becomes possible. The communication control unit 26 stores a result according to whether the wireless signal was successfully received at the time of release from the sleep state in the log storage unit 27 (step S105). For example, when a signal transmitted from the wireless terminal 30 is received via the antenna 29 at the time the sleep state is released, the communication control unit 26 acquires the SSID of the wireless terminal 30 from the received signal, associates the acquired SSID with the time of release from the sleep state, and stores the information indicating that the wireless signal was successfully received as an additional communication log in the log storage unit 27. At this time, the communication control unit 26 adds 1 to the value of the counter m.

[0050] On the other hand, when the sleep state is released and the signal transmitted from the wireless terminal 30 has not been received via the antenna 29, the communication control unit 26 associates the time of release from the sleep state, information indicating failure in receiving the wireless signal, and a value indicating failure in communication, and stores them as an additional communication log in the log storage unit 27. At this time, the communication control unit 26 adds 1 to the value of the counter n.

[0051] Thereafter, the communication control unit 26 judges whether or not the transmission condition of the communication log is satisfied (step S106). The transmission condition of the communication log is that the values ​​of the counter m and the counter n are equal to or greater than a predetermined number (e.g., m≧Tm, n≧Tn). The transmission condition of the communication log may be any condition that is satisfied when a certain amount of communication logs indicating successful communication and communication logs indicating unsuccessful communication are accumulated. Tm and Tn may be the same value or different values.

[0052] If the communication log transmission condition is not satisfied (step S106-NO), the sleep control unit 25 judges whether the current time is the time included in the sleep release signal (step S107). If the current time is the time included in the sleep release signal (step S107-YES), the ONU 20 executes the process of step S105.

[0053] On the other hand, if the current time is not the time included in the sleep release signal (step S107-NO), the sleep control unit 25 controls the power storage unit 23 to transition the communication control unit 26 and the LPWA chip 28 to a sleep state (step S108). When the communication control unit 26 and the LPWA chip 28 transition to a sleep state, the sleep control unit 25 waits until the time included in the sleep release signal arrives. Then, when the time included in the sleep release signal arrives, the sleep control unit 25 controls the power storage unit 23 to release the sleep state of the communication control unit 26 and the LPWA chip 28 (step S104). Then, the processes from step S105 onwards are executed.

[0054] In the process of step S106, if the transmission condition of the communication log is satisfied (step S106-YES), the communication control unit 26 acquires all communication logs stored in the log storage unit 27. The communication control unit 26 outputs all acquired communication logs to the transmission / reception unit 24. Note that the communication control unit 26 may delete the acquired communication logs from the log storage unit 27. The transmission / reception unit 24 converts the communication logs output from the communication control unit 26 into an optical signal and transmits the optical signal to the OLT 10 via the optical transmission path 40 (step S110). Thereafter, the sleep control unit 25 controls the power storage unit 23 to transition the communication control unit 26 and the LPWA chip 28 to a sleep state (step S111).

[0055] The data transmitter / receiver 12 of the OLT 10 receives the optical signal transmitted from the ONU 20 (step S112). The data transmitter / receiver 12 converts the received optical signal into a communication log of an electrical signal. The data transmitter / receiver 12 outputs the communication log to the control unit 13. The control unit 13 stores the communication log received by the data transmitter / receiver 12 in the log storage unit 14 (step S113). The learning unit 15 generates a trained model by performing learning using the communication log stored in the log storage unit 14 (step S114). The learning unit 15 stores the generated trained model in the trained model storage unit 16.

[0056] The control signal generating unit 18 generates a sleep release signal based on the learned model stored in the learned model storage unit 16 (step S115). The process of generating a sleep release signal based on the learned model will be described later. The control signal generating unit 18 outputs the generated sleep release signal to the data transceiver unit 12. The data transceiver unit 12 converts the sleep release signal output from the control signal generating unit 18 into an optical signal and transmits the optical signal to the ONU 20 via the optical transmission path 40 (step S116). Thereafter, the OLT 10 updates the learned model by performing learning every time it receives a communication log from the ONU 20. Updating the learned model means re-adjusting the coefficients used in the machine learning model so that the loss function is minimized.

[0057] The sleep control unit 25 of the ONU 20 determines whether or not a sleep release signal has been received (step S117). If the sleep release signal has not been received (step S117-NO), the ONU 20 waits in a sleep state until the sleep release signal is received. On the other hand, if the sleep release signal has been received (step S117-YES), the sleep control unit 25 controls the power storage unit 23 to release the sleep state of the communication control unit 26 and the LPWA chip 28 at the time included in the sleep release signal (step S104). Thereafter, the ONU 20 executes the processes from step S105 onward.

[0058] 6 is a flowchart showing the flow of a process for generating a sleep release signal performed by the OLT 10 in the embodiment. It is assumed that a trained model is stored in the trained model storage unit 16 at the start of the process in FIG. The control signal generating unit 18 receives an input of an estimation target period (step S201). Information on the estimation target period may be input to the OLT 10 by a user operating the OLT 10 or an external device. For example, assume that the current time is "0:00:03" as the estimation target period, and information that "estimates from the current time to 5 seconds ahead at 1-second intervals" is input.

[0059] The control signal generating unit 18 inputs the estimation target period to the trained model stored in the trained model storage unit 16 to obtain an estimation result. When the above estimation target period is input to the trained model, estimation results are obtained for "00:00:04", "00:00:05", "00:00:06", "00:00:07", and "00:00:08". FIG. 7 is a diagram showing an example of an estimation result obtained from the trained model.

[0060] Figure 7 shows that the estimation result for the estimation target period "00:00:04" is a "success rate of 70%", the estimation result for "00:00:05" is a "success rate of 5%", the estimation result for "00:00:06" is a "success rate of 23%", the estimation result for "00:00:07" is a "success rate of 90%", and the estimation result for "00:00:08" is a "success rate of 5%".

[0061] Next, the control signal generating unit 18 determines the number of times N at which the ONU 20 can cancel the sleep state based on the remaining battery level of the ONU 20 and the power consumption information stored in the setting value storage unit 17. awake For example, when the power consumption indicated by the power consumption information is 50 mAh and the remaining battery power is 110 mAh, the number of times that the sleep can be cancelled is calculated (step S203). awake This happens twice.

[0062] Next, the control signal generating unit 18 refers to the estimation results obtained by the trained model, and calculates the number N of estimation results whose success rate exceeds the threshold value stored in the setting value storage unit 17 (hereinafter referred to as "successful estimation results"). A Here, if the threshold is 60% and the results shown in FIG. 7 are obtained, the number of successful estimation results N A becomes 2. Fig. 8 is a diagram showing the relationship between the estimation result and the threshold value in the embodiment.

[0063] Next, the control signal generating unit 18 determines the number of times that the sleep cancel can be performed, N awake and the number of successful estimation results N A (Step S204) awake The number of successful estimation results is N AIf it is equal to or less than (step S204-N awake ≦N A ), the control signal generator 18 selects the number of times N awake The control signal generator 18 selects the times associated with the (e.g., two) estimation results (step S205). In the case of the results shown in Fig. 8, the control signal generator 18 selects the estimation target periods "00:00:04" and "00:00:07", which are associated with the estimation results "70%" and "90%".

[0064] The control signal generating unit 18 generates a sleep release signal including the selected time (step S206). The control signal generating unit 18 outputs the generated sleep release signal to the data transmitting / receiving unit 12. The data transmitting / receiving unit 12 converts the sleep release signal output from the control signal generating unit 18 into an optical signal and transmits the optical signal to the ONU 20 via the optical transmission path 40 (step S207).

[0065] In the process of step S204, the number of times that the sleep can be cancelled N awake The number of successful estimation results is N A Greater than (step S204-N awake >N A ), the control signal generator 18 determines whether the number of successful estimation results is N A A time corresponding to one (e.g., two) estimation results is selected (step S208). Note that the time when the number of successful estimation results is N A However, in ONU20, the number of sleep releases possible and the number of successful estimation results N A The difference between this and "N awake -N A Therefore, the control signal generating unit 18 can release the sleep state only "N awake -N A " times are randomly selected (step S209). At this time, the control signal generating unit 18 may select a time for which no estimation result has been obtained (for example, a time after "0:00:08" in the example of FIG. 7), or may randomly select a time from among times for which an estimation result has been obtained.

[0066] The control signal generating unit 18 generates a sleep release signal including the time selected in the processes of steps S208 and S209 (step S210). The control signal generating unit 18 outputs the generated sleep release signal to the data transmitting / receiving unit 12. The data transmitting / receiving unit 12 converts the sleep release signal output from the control signal generating unit 18 into an optical signal and transmits the optical signal to the ONU 20 via the optical transmission path 40 (step S211).

[0067] In addition, when the sleep mode of the ONU 20 is released in the process of Fig. 6, the OLT 10 can acquire the communication log from the ONU 20 if the transmission condition of the communication log is satisfied. In this case, a new communication log is stored in the log storage unit 14 of the OLT 10. Therefore, the learning unit 15 may be configured to re-learn the trained model using the newly acquired communication log. This configuration makes it possible to improve the accuracy of the output (estimation result) of the trained model.

[0068] As an example of the processing in steps S208 and S209, awake As shown in Figure 8, the number of successful prediction results is 5. A An example will be described below in which N is 2. In this case, the number of successful estimation results N A Even if the ONU 20 is notified of a sleep release signal including the times "0:00:04" and "0:00:07", which are the times selected as the sleep release times, the number of times N awake Since =5, ONU 20 can wake up three more times. Therefore, ONU 20 randomly selects three additional suitable times and calculates the number of successful estimation results N A The ONU 20 is then notified of a sleep release signal including the two times selected as the "success rate." As a result, the ONU 20 will perform sleep release at the two times with the highest estimated success rates ("00:00:04" and "00:00:07") and three other times selected at random.

[0069] The reason for mixing in randomly selected times as described above is to collect training data at unknown times to make the trained model smarter. A If the sleep mode is released at this time, the learned model will output biased and inaccurate estimation results if the learning by the learning unit 15 is not successful. If the OLT 10 transmits a sleep release instruction to the ONU 20 based on the estimation results obtained from such a learned model, there is a high possibility that reception will fail.

[0070] On the other hand, by mixing in wake-ups at random times, the diversity of wake-up attempt data will increase, and it is expected that the probability of producing "successfully received" training data will increase, making it easier for learning to progress.

[0071] The optical power supply system 100 configured as above includes a control signal generating unit 18 that generates a sleep release signal including one or more pieces of time information when communication between the ONU 20 and the wireless terminal 30 is estimated to be successful based on a communication log including information on the success or failure of communication when the sleep state of the ONU 20 is released, and a data transmitting / receiving unit 12 that converts the generated sleep release signal into an optical signal and transmits it to the ONU 20. As a result, the ONU 20 can release the sleep state at the time when communication with the wireless terminal 30 is estimated to be successful. Furthermore, when communication with the wireless terminal 30 is not performed, the ONU 20 can be put into a sleep state. Therefore, it is possible to improve the success rate of receiving the upstream signal while saving power in an optical communication device that communicates with a terminal device that transmits an upstream signal.

[0072] Furthermore, the control signal generating unit 18 acquires one or more estimation results using a trained model that has been trained to output an estimation result of the reception success rate of the wireless terminal 30 at each time indicated by the input estimation target period, and acquires one or more time information based on the acquired one or more estimation results. In this way, by using a trained model that has been trained in advance, it is possible to easily obtain an estimation result of the reception success rate. Then, based on the obtained estimation result of the reception success rate, it is possible to select a time for waking up the sleep of the ONU 20. Therefore, it is possible to wake up the sleep of the ONU 20 at a timing when the reception success rate is high. Therefore, it is possible to improve the reception success rate of the upstream signal with low power consumption in an optical communication device that communicates with a terminal device that transmits an upstream signal.

[0073] The following describes modified examples. In the above-described embodiment, a configuration has been shown in which the OLT 10 includes the learning unit 15 and generates a trained model. The learning unit 15 may be implemented in another device, and the OLT 10 may be configured to execute the above-described processing using a trained model generated by the other device. When configured in this way, the OLT 10 transmits a communication log to the other device and receives trained model data from the other device.

[0074] In Figure 6, the number of times that sleep can be released is N awake The number of successful estimation results is N A Even if the number of possible sleep releases is less than or equal to the number of times N, a random sleep release may be mixed into the sleep release signal in order to increase the diversity of the sleep release times and speed up the learning process. awake The number of successful predictions is N A In the case where there are three estimation results, the control signal generating unit 18 may not select all of the times associated with the three estimation results, but may instead select the times associated with the two estimation results (e.g., in order of highest success rate) and select one random time instead, and generate a sleep release signal including the three times in total.

[0075] Some of the functional units of the OLT 10 and ONU 20 in the above-mentioned embodiment may be realized by a computer. In that case, a program for realizing this function may be recorded in a computer-readable recording medium, and the program recorded in the recording medium may be read into a computer system and executed to realize the function. The term "computer system" here includes hardware such as an OS and peripheral devices. The term "computer-readable recording medium" refers to portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into a computer system. The term "computer-readable recording medium" may also include a medium that dynamically holds a program for a short period of time, such as a communication line when a program is transmitted via a network such as the Internet or a communication line such as a telephone line, and a medium that holds a program for a certain period of time, such as a volatile memory inside a computer system that is a server or client in that case. The above-mentioned program may be a program for realizing some of the above-mentioned functions, or may be a program that can realize the above-mentioned functions in combination with a program already recorded in the computer system, or may be a program that is realized using a programmable logic device such as an FPGA (Field Programmable Gate Array).

[0076] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and designs that do not deviate from the gist of the present invention are also included. [Industrial Applicability]

[0077] The present invention can be applied to an optical communication system that performs optical power feeding. [Explanation of symbols]

[0078] 10...OLT, 20...ONU (optical communication device), 30, 30-1, 30-2...wireless terminal, 11...optical power supply unit, 12...data transmission / reception unit, 13...control unit, 14...log storage unit, 15...learning unit, 16...trained model storage unit, 17...setting value storage unit, 18...control signal generation unit, 22...light receiving unit, 23...power storage unit, 24...transmission / reception unit, 25...sleep control unit, 26...communication control unit, 27...log storage unit, 28...LPWA chip, 29...antenna

Claims

1. a control signal generating unit that generates a sleep release signal including one or more pieces of time information that indicates when communication between a power receiving optical communication device driven by power obtained from an optical signal for power supply and a terminal device performing wireless communication is expected to be successful, based on a communication log including information on whether communication has been successful or not when a sleep state of the power receiving optical communication device is released; an optical communication unit that converts the generated sleep release signal into an optical signal and transmits the optical signal to the power receiving optical communication device; An optical communication device comprising:

2. The control signal generation unit receives period information regarding a period to be estimated for waking up from sleep, acquires one or more estimation results using a trained model trained to output an estimation result of a reception success rate of the power receiving optical communication device at each time indicated by the input period information, and acquires the one or more time information based on the acquired one or more estimation results.

2. The optical communication device according to claim 1.

3. The control signal generation unit identifies a success estimation result in which the reception success rate is equal to or greater than a threshold from among the one or more acquired estimation results, and generates the sleep release signal including at least one piece of time information associated with the identified success estimation result.

3. The optical communication device according to claim 2.

4. the control signal generation unit calculates a possible number of times of release representing the number of times the sleep can be released in the power receiving optical communication device based on power information representing the remaining power of the power receiving optical communication device and information on the power consumed in the release from sleep, compares the calculated possible number of times of release with the success estimation result, and determines the one or more pieces of time information to be included in the release signal according to the comparison result.

4. The optical communication device according to claim 3.

5. The control signal generating unit If the number of times the game can be released is equal to or less than the number of the estimated successful results, Selecting the estimated success results in the order of the highest success rate of reception, the number of which corresponds to the number of times that can be released, and generating the sleep release signal including information on the time associated with the selected estimated success results; Or, selecting the success estimation results in order of the highest success rate of reception, the success estimation results being less than the number of times that the release can be performed, and generating the sleep release signal including information on a time associated with the selected success estimation result and information on a randomly selected time; 5. The optical communication device according to claim 4.

6. The control signal generating unit If the number of possible releases is greater than the number of the estimated successful results, randomly determining new time information corresponding to a difference between the number of times that the release can be performed and the number of the estimated successful results, and generating the sleep release signal including the determined new time information and time information associated with the estimated successful results; 5. The optical communication device according to claim 4.

7. The communication log includes release time information when the sleep state of the power receiving optical communication device is released and a name of a network to which the terminal device is connected, A learning unit that generates the trained model by using the release time information as training data and the network name and the information on the success or failure of the communication as teacher data.

3. The optical communication device according to claim 2.

8. Based on a communication log including information on the success or failure of communication at the time of waking up a sleep state of a power receiving optical communication device driven by power obtained from an optical signal for power supply, a sleep wake-up signal is generated including one or more pieces of time information indicating that communication between the power receiving optical communication device and a terminal device performing wireless communication will be successful; The sleep control method further comprises converting the generated sleep release signal into an optical signal and transmitting the optical signal to the power receiving optical communication device.

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