Control device and control method

Abstract

A control device comprising: a collection unit that acquires cooperation information from a plurality of communication stations that are connected to one or more terminals directly or via another device; and an analysis unit that classifies the plurality of communication stations into a plurality of groups on the basis of the cooperation information, determines one or more communication stations targeted for sleep control from among the plurality of communication stations belonging to a group among the plurality of classified groups, and impements sleep control in the determined one or more communication stations targeted for sleep control.　

Description

Control device and control method

[0001] The present invention relates to a control device and a control method.

[0002] In conventional communication systems that perform wireless communication between terminals and base stations, each base station calculates its throughput and autonomously goes into sleep mode when the throughput exceeds a threshold, thereby saving power. In such communication systems, terminals connected to the sleeping base station are instructed to hand over to the base station with the highest throughput, allowing the terminal to continue communication.

[0003] Yong Sheng Soh, Tony QSQuek, and Marios Kountouris, “Dynamic Sleep Mode Strategies in Energy Efficient Cellular Networks”, IEEE, Communications Theory, pp.3131 3136, June 2013.

[0004] However, in conventional communication systems, a terminal connected to a sleeping base station may be handed over to a base station already connected to a large number of terminals, resulting in a deterioration in communication quality.Furthermore, in conventional communication systems, each base station autonomously determines whether to sleep, which can limit the effectiveness of power saving by preventing optimization of the entire system.

[0005] In view of the above circumstances, an object of the present invention is to provide a technique that can increase the effect of power saving without deteriorating communication quality.

[0006] One aspect of the present invention is a control device that includes a collection unit that acquires cooperation information from multiple communication stations that are connected to one or more terminals directly or via other devices, and an analysis unit that classifies the multiple communication stations into multiple groups based on the cooperation information, determines one or more communication stations that are to be subject to sleep control from among multiple communication stations that belong to any of the classified groups, and executes sleep control on the determined one or more communication stations that are to be subject to sleep control.

[0007] One aspect of the present invention is a control method that acquires cooperation information from multiple communication stations that are connected to one or more terminals directly or via other devices, classifies the multiple communication stations into multiple groups based on the cooperation information, determines one or more communication stations that are to be subject to sleep control from among multiple communication stations that belong to any of the classified groups, and executes sleep control on the determined one or more communication stations that are to be subject to sleep control.

[0008] According to the present invention, it is possible to increase the effect of power saving without deteriorating the communication quality.

[0009] 1 is a diagram for explaining an overview of the overall configuration and processing of a mobile NW system in an embodiment. FIG. 1 is a diagram for explaining a method for selecting a potential sleep target. FIG. 2 is a diagram for explaining a method for selecting a central station to be a sleep target in the first embodiment. FIG. 3 is a diagram for explaining a method for selecting a potential sleep wake-up target. FIG. 4 is a diagram for explaining a method for selecting a central station to be a sleep wake-up target in the first embodiment. FIG. 5 is a diagram for explaining a configuration example of a mobile NW system in the first embodiment. FIG. 6 is a flowchart showing an example of the flow of sleep processing (part 1) executed by a management control device in the first embodiment. FIG. 7 is a flowchart showing an example of the flow of sleep processing (part 2) executed by a management control device in the first embodiment. FIG. 8 is a flowchart showing an example of the flow of sleep processing (part 2) executed by a management control device in the first embodiment. FIG. 9 is a diagram showing an example of the flow of sleep processing (part 1) executed by a management control device in the first embodiment. FIG. 10 is a diagram showing an example of the flow of sleep processing (part 1) executed by a management control device in the first embodiment. FIG. 1 is a diagram showing an example of the configuration of a mobile NW system in a seventh modified example of the first embodiment. FIG. 2 is a diagram for explaining an overview of the processing of a mobile NW system in a second embodiment. FIG. 3 is a diagram showing an example of the configuration of a mobile NW system in a second embodiment. FIG. 4 is a flowchart showing an example of the flow of sleep processing (part 1) performed by a management control device in a second embodiment. FIG. 5 is a flowchart showing an example of the flow of sleep release processing (part 1) performed by a management control device in a second embodiment. FIG. 6 is a flowchart showing an example of the flow of sleep processing (part 2) performed by a management control device in a second embodiment. FIG. 7 is a flowchart showing an example of the flow of sleep release processing (part 2) performed by a management control device in a second embodiment.FIG. 1 is a diagram for explaining an overview of the overall configuration and processing of a wired NW system in an embodiment. FIG. 2 is a diagram showing an example of the configuration of a wired NW system in a third embodiment. FIG. 3 is a flowchart showing an example of the flow of sleep processing (part 1) executed by a management control device in a third embodiment. FIG. 4 is a flowchart showing an example of the flow of sleep release processing (part 1) executed by a management control device in a third embodiment. FIG. 5 is a flowchart showing an example of the flow of sleep processing (part 2) executed by a management control device in a third embodiment. FIG. 6 is a flowchart showing an example of the flow of sleep release processing (part 2) executed by a management control device in a third embodiment.

[0010] An embodiment of the present invention will be described below with reference to the drawings. (Outline of First Embodiment) Fig. 1 is a diagram for explaining an overview of the overall configuration and processing of a mobile network system in an embodiment. First, the overall configuration of the mobile network system will be described. The mobile network system is an example of a communication system. The mobile network system is, for example, a fifth-generation mobile communication system (hereinafter referred to as "5G"). The mobile network system includes multiple radio stations 12, a transfer device 14, multiple central stations 16, and a management control device 20.

[0011] Each wireless station 12 and the transfer device 14, and each wireless station 14 and each central station 16 are connected by optical fiber that transmits optical signals. The transfer device 14 and the management control device 20, and each central station 16 and the management control device 20 are connected by electric wires or optical fiber that transmit electric signals. The example shown in Fig. 1 shows a case where there are M (M is an integer of 2 or more) wireless stations 12 and N (N is an integer of 2 or more) central stations 16. Note that although multiple transfer devices 14 may be provided, the following explanation will be given using a single device as an example.

[0012] Each wireless station 12 includes one or more antennas and performs wireless communication with one or more terminals 11. For example, each wireless station 12 receives signals transmitted from one or more terminals 11 and transmits the received signals to a central station 16 connected via a transfer device 14. Each wireless station 12 transmits the signals received via the transfer device 14 to one or more terminals 11. The wireless station 12 is, for example, a radio unit (RU) in the 5G communication standard. The wireless station 12 is one aspect of another device.

[0013] If the radio station 12 has multiple antennas, the radio station 12 may perform wireless communication with one or more terminals 11 using beamforming. The radio station 12 transitions to a sleep state in accordance with a sleep instruction transmitted from the management control device 20. The sleep state is a state in which power saving is possible by stopping some functions or stopping the entire device. Furthermore, the radio station 12 controls the optical path in accordance with an optical path control instruction transmitted from the management control device 20. An optical path is a route along which an optical signal propagates. The optical path control instruction is an instruction related to optical path control, and includes, for example, an instruction to start setting up an optical path and an instruction to stop setting up an optical path. For example, the radio station 12 stops setting up an optical path with the transfer device 14 in response to receiving the optical path control instruction. Stopping the setting up of an optical path in the radio station 12 means not emitting light on the path from the radio station 12 to the transfer device 14 (stopping light emission).

[0014] The transfer device 14 is provided between the radio station 12 and the central station 16. The transfer device 14 is a switch that connects the radio station 12 and the central station 16 via an optical path. The transfer device 14 controls the optical path in accordance with control instructions (hereinafter referred to as "optical path control information") related to the optical path transmitted from the management control device 20. For example, the optical path control performed by the transfer device 14 includes switching of the optical path and formation of a new optical path. The transfer device 14 controls the connection between the radio station 12 and the central station 16 by controlling the optical path. For example, upon receiving optical path control information for the optical path transmitted from the management control device 20, the transfer device 14 performs switching so that the optical path is connected between the radio station 12, which is the switching destination of the optical path, and the central station 16.

[0015] The central station 16 receives uplink signals transmitted from one or more wireless stations 12 via the transfer device 14. The central station 16 transmits downlink signals to the wireless stations 12 connected via the transfer device 14. The uplink signals transmitted from one or more wireless stations 12 are signals transmitted by the terminal 11, and the downlink signals are signals addressed to the terminal 11. Each central station 16 transitions to a sleep state in accordance with a sleep instruction transmitted from the management control device 20. The central station 16 is, for example, a distributed unit (DU) in the 5G communication standard. Information acquired by the management control device 20 from the central station 16 is called cooperation information. The cooperation information is information indicating the state of communication between each central station 16 and one or more terminals 11. The central station 16 is one aspect of a communication station.

[0016] The coordination information in the first embodiment includes, for example, information on the traffic volume of each central office 16. Hereinafter, the traffic volume information is referred to as traffic information. Note that, for example, traffic information is described in DCI (Downlink Control Information) or O-RAN CTI (O-RAN.WG4.CTI-TCP.0-v01.00). In the O-RAN CTI, it refers to schedule information. Furthermore, the central office 16 controls the optical paths in accordance with the optical path control instructions transmitted from the management and control device 20. For example, the central office 16 stops setting up the optical path between the central office 16 and the transfer device 14 in response to receiving the optical path control instruction. Stopping the setting up of the optical path in the central office 16 means not irradiating light on the path from the central office 16 to the transfer device 14 (stopping the optical irradiation).

[0017] The management control device 20 is a device that manages the entire mobile NW system. The management control device 20 acquires coordination information from each central station 16. The management control device 20 uses a coordination interface when acquiring coordination information from each central station 16. The coordination interface is an interface that connects the management control device 20 and each central station 16. The management control device 20 determines whether optical path control and sleep control are necessary based on the acquired coordination information. For example, if the management control device 20 determines that sleep control is necessary, it determines that optical path control is necessary. If the management control device 20 determines that optical path control and sleep control are necessary, it performs optical path control processing and sleep control processing. The optical path control processing is processing that switches optical paths between the radio stations 12 and the central station 16 and generates optical paths. The sleep control processing is processing that executes sleep or cancels sleep for each radio station 12 and each central station 16 that are subject to sleep control.

[0018] The transfer device 14 and the management control device 20 are installed in a section called a mobile front haul (MFH). The central station 16 may be regarded as an aggregation station, the radio stations 12 as distributed stations, and the transfer device 14 and the management control device 20 may be regarded as being installed in a mobile mid haul (MMH).

[0019] Next, an overview of the processing of the mobile network system will be explained. The upper diagram of Fig. 1 shows the connection state of the mobile network system before optical path switching, and the lower diagram of Fig. 1 shows the connection state of the mobile network system after optical path switching. The upper diagram of Fig. 1 shows an example in which terminals 11-1 and 11-2 are connected to wireless station 12-1, wireless station 12-1 is connected to central station 16-1 via transfer device 14, terminals 11-3 and 11-4 are connected to wireless station 12-M, and wireless station 12-M is connected to central station 16-N via transfer device 14.

[0020] The management and control device 20 determines, based on the cooperation information collected from each central office 16, that sleep control is necessary when one central office 16 can accommodate the traffic of the other central offices 16. That is, based on the cooperation information collected from each central office 16, the management and control device 20 performs optical path control processing and sleep control processing when one central office 16 can accommodate the traffic of the other central offices 16. For example, the management and control device 20 performs optical path control processing and sleep control processing in central office 16-N when all of the traffic of central office 16-1 can be accommodated. In this way, by accommodating the traffic of the other central offices 16 in one central office 16, the other central offices 16 that no longer have traffic can transition to a sleep state.

[0021] When performing optical path control processing, the management control device 20 transmits information on the optical path switching destination to the transfer device 14, and instructs the radio station 12 and the central station 16, which are the targets of optical path switching, to switch the optical path. For example, the management control device 20 transmits information on the optical path switching destination to the transfer device 14, for switching the optical path between the radio station 12-1 and the central station 16-1 to the optical path between the radio station 12-M and the central station 16-N, and instructs the radio station 12-1 and the central station 16-1, which are the targets of optical path switching, to switch the optical path.

[0022] Since the connection destination of the terminal 11 changes due to the switching of the optical path, the management control device 20 may instruct the central station 16, which is the target of the optical path switching, to change the connection. The transfer device 14 switches the optical path between the radio station 12 and the central station 16 in accordance with the instruction from the management control device 20. After the optical path switching is completed, the transfer device 14 notifies the management control device 20 of the completion of the optical path switching. The radio station 12 and the central station 16, which are the target of the optical path switching, switch the optical path in accordance with the instruction from the management control device 20.

[0023] When the optical path control process is completed, the management control device 20 transmits a sleep permission notification to the radio stations 12 and the central station 16 that are to be transitioned to the sleep state. The sleep permission notification is a signal that includes an instruction to transition the radio stations 12 and the central station 16 to the sleep state. As a result, the radio stations 12 and the central station 16 that are to be transitioned to the sleep state transition to the sleep state.

[0024] 1 shows an example in which terminals 11-1 to 11-4 are connected to wireless station 12-M, and wireless station 12-1 and central station 16-1 are in a sleep state. Hereinafter, the wireless station 12 and central station 16 that are the targets of optical path switching may be referred to as a switching source wireless station and a switching source central station, respectively, and the wireless station 12 and central station 16 that are the destination of optical path switching may be referred to as a switching destination wireless station and a switching destination central station, respectively.

[0025] Next, a method for selecting a central station 16 to be put into sleep mode in the first embodiment will be described. Here, the differences between a possible method for selecting a central station 16 to be put into sleep mode (hereinafter referred to as a "potential sleep-target selection method") and the selection method of the present invention will be explained. FIG. 2 is a diagram for explaining the potential sleep-target selection method. In FIG. 2, central stations 1 to 4 are used as an example. FIG. 2A shows traffic information collected from each of central stations 1 to 4. In the potential sleep-target selection method, when performing sleep control, the traffic volume of each central station is added up in order without reference to the traffic volume of each station, and compared with a threshold. For example, in the example shown in FIG. 2B, the total value obtained by adding up the traffic volume of central station 1 and the traffic volume of central station 2 is compared with the threshold. As shown in FIG. 2B, since the total value is less than the threshold, the management control device selects central station 2 as the sleep target, as shown in FIG. 2C.

[0026] The management control device then sums the traffic volume of central station 3 with that of central station 1, as shown in Fig. 2(D), and compares the sum with a threshold. For example, in the example shown in Fig. 2(D), the total value obtained by adding together the traffic volumes of central station 1, central station 2, and central station 3 is compared with the threshold. As shown in Fig. 2(D), the total value exceeds the threshold, so the management control device determines that central station 3 cannot go to sleep.

[0027] Next, the management control device sums the traffic volume of central station 4 to that of central station 1 and compares the sum with a threshold, as shown in Fig. 2(E). For example, in the example shown in Fig. 2(E), the total value obtained by adding together the traffic volumes of central station 1, central station 2, and central station 4 is compared with the threshold. As shown in Fig. 2(E), the total value exceeds the threshold, so the management control device determines that central station 4 cannot go to sleep.

[0028] As a result, in the proposed sleep target selection method, only one central station, central station 2, is determined to be the sleep target. However, as can be seen from FIG. 2 , the traffic volume of central stations 3 and 4 is relatively small, and even if the traffic of central stations 3 and 4 is consolidated into central station 1, the traffic volume does not exceed the threshold. Therefore, if the traffic of central stations 3 and 4 is consolidated into central station 1, both central stations 3 and 4 can be determined to be the sleep targets. In this way, by determining the sleep target based on the traffic volume, it is believed that the sleep target can be determined more efficiently.

[0029] 3 is a diagram illustrating a method for selecting a central station to be put into sleep mode in the first embodiment. In FIG. 3, central stations 1 to 6 are used as an example. (A) of FIG. 3 shows traffic information collected from each of central stations 1 to 6 and the predicted traffic volume for each of central stations 1 to 6. In this way, the management control device 20 in the first embodiment predicts traffic volume for a certain period of time using past traffic information collected from each of central stations 1 to 6.

[0030] Thereafter, the management control device 20 classifies each of the central stations 1 to 6 into a plurality of groups based on the traffic volume prediction results. For example, the management control device 20 classifies each of the central stations 1 to 6 into either a first group or a second group. The first group is a group for which the traffic volume prediction results indicate that the traffic transition is constant or regular. The second group is a group for which the traffic volume prediction results indicate that the traffic transition is constant or irregular. In other words, the second group is a group for which the traffic transition is irregular as a result of the traffic volume prediction.

[0031] One possible method for determining whether each central station belongs to the first or second group is to divide past samples into fixed time periods, calculate the maximum value, and then set an upper limit on the magnitude of variance or the correlation with time (the magnitude of the correlation coefficient) for the maximum value calculated for each interval. However, this determination method is not limited to this, and any other method may be used as long as it classifies each central station into either the first or second group based on the traffic volume prediction results. When using the magnitude of variance, the management control device 20 calculates the variance of the maximum values ​​calculated for each interval, and classifies the central station into the first group if the calculated variance value is less than a threshold, and into the second group if the calculated variance value is equal to or greater than the threshold. As a result, as shown in FIG. 3B, the management control device 20 classifies central stations 1, 2, and 3 into the first group (a group with consistent or regular traffic trends) and central stations 4, 5, and 6 into the second group (a group with irregular traffic trends).

[0032] The management control device 20 then selects a central station to be put into sleep mode within at least one of the first group or the second group. Here, a case where the management control device 20 selects a central station to be put into sleep mode within the first group will be described. The management control device 20 aggregates traffic among central stations 1, 2, and 3 belonging to the first group. For example, the management control device 20 selects the largest traffic volume among the predicted traffic volumes from each of central stations 1, 2, and 3 belonging to the first group. That is, the management control device 20 selects the value that maximizes the traffic volume in the traffic volume prediction results for central station 1, the value that maximizes the traffic volume in the traffic volume prediction results for central station 2, and the value that maximizes the traffic volume in the traffic volume prediction results for central station 3. Hereinafter, the value that maximizes the traffic volume in the traffic volume prediction results will be referred to as the maximum predicted value.

[0033] Then, as shown in (C) of FIG. 3, the management control device 20 sequentially sums up the predicted maximum values ​​of the selected central stations 1, 2, and 3. In this case, the management control device 20 may sum up the predicted maximum values ​​in ascending or descending order. Summing up the predicted maximum values ​​in descending order may enable consolidation of many central stations, in which case many central stations can be put into sleep mode. As a result, the power saving effect can be improved. The management control device 20 sums up the predicted maximum values ​​up to the point where the threshold value is not exceeded. Note that the threshold value in (C) of FIG. 3 indicates the maximum traffic volume that the central station can handle.

[0034] As a specific example of processing, taking the case of adding up the maximum predicted values ​​in ascending order, the management control device 20 first adds up the maximum predicted value of the central station with the smallest maximum predicted value and the maximum predicted value of the central station with the second smallest maximum predicted value. The management control device 20 compares the added total with a threshold. If the total is less than the threshold, the management control device 20 adds the maximum predicted value of the central station with the third smallest maximum predicted value to the total to calculate a new total. The management control device 20 then compares the added total with the threshold again. The management control device 20 repeats this processing until the total exceeds the threshold or until there are no more maximum predicted values ​​to add up.

[0035] If the total value exceeds the threshold, the management control device 20 selects a sleep target based on the maximum predicted value added up to the time before the threshold was exceeded. For example, the management control device 20 selects a sleep candidate based on the central station with the maximum predicted value added up to the time before the threshold was exceeded. Similarly, when there are no more maximum predicted values ​​to add up, the management control device 20 selects a sleep target based on the maximum predicted value added up to the time before the threshold was exceeded. In the example shown in FIG. 3C , the sum of the maximum predicted values ​​of central station 1, central station 2, and central station 3 does not exceed the threshold. Therefore, central station 1, central station 2, and central station 3 are selected as sleep candidate targets. Here, before selecting a sleep target, the management control device 20 determines a central station to be aggregated from among central station 1, central station 2, and central station 3. For example, the management control device 20 may determine the central station with the largest traffic volume among the sleep candidate targets as the aggregation target central station, or the central station with the largest maximum predicted value as the aggregation target central station, or may determine the central station based on a predetermined priority order.

[0036] The method for determining the central station to be the aggregation destination is not limited to the above method, and other methods may be used. For example, the management control device 20 may determine the central station with the second largest traffic volume among the sleep candidate targets as the aggregation destination central station. In the following explanation, it is assumed that the management control device 20 determines central station 1 as the aggregation destination central station.

[0037] The management control device 20 then selects central station 2 and central station 3 as sleep candidates from among central station 1, central station 2, and central station 3. The management control device 20 then controls optical path switching to aggregate traffic from central station 2 and central station 3 into central station 1. This allows central station 2 and central station 3 to transition to a sleep state, as shown in FIG. 3D.

[0038] After consolidating the traffic, the management control device 20 holds the sum of the predicted maximum values ​​for the central station that aggregates the traffic (central station 1 in FIG. 3) and the central stations that aggregated the traffic (central stations 2 and 3 in FIG. 3) for the first group. This held sum of the predicted maximum values ​​is used when the sleep mode is released.

[0039] The management control device 20 may select a central station to be put to sleep in the same manner for the second group. Note that after aggregating the traffic, the management control device 20 does not store the total of the predicted maximum values ​​of the central station to which the traffic is aggregated and the central stations that aggregated it for the second group. This is because, unlike the first group, the traffic flowing through the central stations belonging to the second group is irregular, and it is therefore desirable to predict the traffic volume each time.

[0040] The above is the method for selecting a sleep target in the first embodiment. Next, we will explain the method for selecting a central station 16 to be woken up in the first embodiment. Here, we will explain the differences between the selection method of the present invention and the method that can be considered when selecting a central station 16 to be woken up (hereinafter referred to as the "potential sleep wake target selection method"). Figure 4 is a diagram for explaining the potential sleep wake target selection method. In Figure 4, central stations 1 to 4 are used as an example. As shown in Figure 4A, central stations 2 to 4 are assumed to be in a sleep state. If the traffic volume of central station 1 exceeds a threshold, the management control device determines to wake up the central station. In this case, the management control device wakes up the central station in order, starting with the central station with the most recently added traffic volume, as shown in Figure 4B.

[0041] For example, the management control device determines the central stations to be woken up in order of the most recently added traffic volume, such as central station 4, central station 3, etc., so that the traffic volume of central station 1 is less than the threshold. As a result, in the expected wake-up target selection method, as shown in Figure 4C, central stations 3 and 4 are determined as wake-up targets, and only central station 2 continues to be in sleep mode. However, as can be seen from Figure 4, the traffic volumes of central stations 3 and 4 are relatively low, while the traffic volume of central station 2 is high. In this case, if central station 2 is determined as the wake-up target, the other central stations can continue to be in sleep mode. In this way, it is believed that determining the wake-up target based on traffic volume can more efficiently determine the wake-up target.

[0042] 5 is a diagram illustrating a method for selecting a central station to be released from sleep mode in the first embodiment. In FIG. 5, central stations 1 to 3 are used as an example. Here, the case where the management control device 20 selects a central station to be released from sleep mode within the first group is described.

[0043] As shown in Figure 5A, assume that central station 2 and central station 3 are in a sleep state. The management control device 20 calculates the traffic volume based on the coordination information collected from central station 1 and compares the calculated traffic volume with the total value of the maximum predicted values ​​stored. In the example shown in Figure 5A, the calculated traffic volume (currently flowing traffic) does not exceed the total value of the maximum predicted values. Therefore, the management control device 20 determines that waking up from sleep is not necessary in the state shown in Figure 5A.

[0044] If a sudden increase in traffic volume causes the traffic volume currently flowing through the central station 1 to exceed the total value of the predicted maximum values, as shown in Figure 5(B), the management control device 20 predicts the traffic volume for a certain period of time using past traffic information collected from the central station 1. Then, as shown in Figure 5(C), if the predicted traffic volume exceeds a threshold indicating the maximum traffic volume that the central station 1 can handle, the management control device 20 decides to resume sleep mode. In this case, the management control device 20 identifies the central station 1 with the largest traffic volume (including a sleeping central station). The management control device 20 may also identify the central station with the largest traffic volume by targeting only sleeping central stations. The traffic volume of the central station 1 is excluded from the target.

[0045] Here, it is assumed that central station 3 has the smallest traffic volume, followed by central station 2 (central station 3 has the largest traffic volume, and central station 2 has the smallest traffic volume). In this case, the management control device 20 identifies central station 3 as the central station with the largest traffic volume. Then, the management control device 20 determines the identified central station 3 as the sleep wake target. The management control device 20 allocates traffic from central station 1 to the determined sleep wake target central station 3. As a result, when the traffic volume of central station 1 falls below the threshold, the management control device 20 ends the selection of the sleep wake target.

[0046] As a result, in the method for selecting a central station to be woken up in the first embodiment, central station 3 is selected as the wake-up target, and central station 2 continues to sleep, as shown in Figure 5D. In this way, in the method for selecting a central station to be woken up in the first embodiment, central stations with high traffic volume are prioritized as wake-up targets, so fewer central stations can be selected as wake-up targets. As a result, the number of central stations that remain in sleep mode can be increased, thereby contributing to power savings.

[0047] The management control device 20 predicts the traffic volume for the second group without comparing the traffic volume in Fig. 5B with the total value of the maximum predicted values ​​it holds. The subsequent processing is the same as the method for selecting a central station to be woken up for the first group.

[0048] A specific configuration for selecting a sleep target and a sleep release target as described above will be described below.

[0049] (Details of the First Embodiment) Fig. 6 is a diagram showing an example of the configuration of a mobile network system 100 according to the first embodiment. The mobile network system 100 according to the first embodiment includes a plurality of wireless stations 12-1 to 12-M, a transfer device 14, a plurality of central stations 16-1 to 16-N, and a management and control device 20. The wireless stations 12, the transfer device 14, and the central station 16 have been described in Fig. 1, and therefore further description thereof will be omitted.

[0050] The management control device 20 includes a collection unit 21, an analysis unit 22, and a control unit 23. The collection unit 21 includes an acquisition unit 211. The acquisition unit 211 collects cooperation information from each central station 16 at a predetermined interval or at any timing. For example, the acquisition unit 211 collects traffic information from each central station 16 as cooperation information.

[0051] The analysis unit 22 includes a storage unit 221 and an information analysis unit 222. The storage unit 221 records the collected linkage information in a predetermined storage device. Furthermore, the storage unit 221 stores the total value of the predicted maximum values ​​calculated by the information analysis unit 222.

[0052] The information analyzer 222 analyzes the state of communication between each central office 16 and the terminal 11 based on the coordination information. Specifically, the information analyzer 222 determines whether optical path control and sleep control are required based on the coordination information. The information analyzer 222, for example, predicts the traffic volume of each central office 16 based on the coordination information stored in the storage unit 221. The information analyzer 222 classifies each central office 16 into either a first group or a second group based on the traffic volume prediction result. Then, the information analyzer 222 determines whether optical path control and sleep control are required for each classified group.

[0053] The information analyzer 222 determines that optical path control and sleep control are necessary, for example, when all of the terminals 11 accommodated by one central office 16 belonging to the first group can be accommodated by any of the central offices 16 belonging to the first group. Similarly, the information analyzer 222 determines that optical path control and sleep control are necessary, for example, when all of the terminals 11 accommodated by one central office 16 belonging to the second group can be accommodated by any of the central offices 16 belonging to the second group.

[0054] When the information analyzer 222 determines that optical path control and sleep control are necessary, it notifies the controller 23 of control information including an optical path control instruction and a sleep instruction. The optical path control instruction is an instruction to request optical path switching, and includes, for example, information indicating the central station 16 that is the source of the optical path switching and information indicating the central station 16 that is the destination of the optical path switching. The sleep instruction is an instruction to execute sleep, and includes, for example, information indicating the radio station 12 and central station 16 that are to be put into sleep mode. The method of selecting the sleep target in the information analyzer 222 is as described in FIG. 3.

[0055] Furthermore, when the traffic volume of a certain central station 16 exceeds a threshold, the information analyzer 222 determines that optical path control and sleep control are necessary. In this case, the information analyzer 222 notifies the control unit 23 of control information including an optical path control instruction and a sleep release instruction. The sleep release instruction is an instruction to release the sleep state, and includes, for example, information indicating the wireless station 12 and central station 16 to be released from sleep. The method of selecting the sleep release target in the information analyzer 222 is as described in FIG. 5.

[0056] The control unit 23 includes an optical path control unit 231 and a sleep control unit 232. The optical path control unit 231 determines the radio station 12 and central station 16 that will be the source of optical path switching and the radio station 12 and central station 16 that will be the destination of optical path switching based on the analysis results of the information analysis unit 222. For example, the optical path control unit 231 determines the radio station 12 and central station 16 that will be the source of optical path switching based on information indicating the central station 16 that will be the source of optical path switching, which is included in the control information notified by the information analysis unit 222. For example, the optical path control unit 231 determines the radio station 12 and central station 16 that will be the destination of optical path switching based on information indicating the central station 16 that will be the destination of optical path switching, which is included in the control information notified by the information analysis unit 222. The optical path control unit 231 holds information about the radio stations 12 connected to the central station 16.

[0057] The optical path control unit 231 transmits optical path control information including information indicating the radio station 12 and central station 16 to which the determined optical path is to be switched to the transfer device 14. As a result, the optical path control unit 231 instructs the transfer device 14 to switch the optical path. Furthermore, the optical path control unit 231 transmits an optical path control instruction to the radio station 12 and central station 16 to which the determined optical path is to be switched.

[0058] Based on the analysis results of the information analysis unit 222, the sleep control unit 232 causes the wireless stations 12 and the central station 16 that are the targets of sleep control to enter or exit sleep mode.

[0059] Fig. 7 is a flowchart showing an example of the flow of sleep processing (part 1) executed by the management control device 20 in the first embodiment. Fig. 7 explains a case where sleep processing is performed on a central station 16 (a central station 16 belonging to the first group) where traffic transitions are constant or regular. The processing in Fig. 7 is repeatedly executed at a predetermined cycle. Note that, in this explanation, traffic information is used as an example of the cooperation information. In Fig. 7, the explanation is given assuming M = N = 4.

[0060] The acquisition unit 211 acquires cooperation information from each of the central stations 16-1 to 16-4 (step S101). For example, the acquisition unit 211 may collect information once per unit time, which is a predetermined cycle, or may collect information at any timing. The unit time here refers to, for example, a slot length, a subframe length, a frame length, 1 millisecond, 1 second, or 1 minute. The acquisition unit 211 stores the acquired cooperation information for each central station 16 in the storage unit 221 (step S102).

[0061] The information analysis unit 222 predicts the traffic trends for each of the central stations 16-1 to 16-4 over a certain period of time (step S103) based on the collaboration information for each central station 16 stored in the storage unit 221. Then, the information analysis unit 222 classifies the central stations 16-1 to 16-4 into either a first group or a second group based on the predicted traffic trends (step S104).

[0062] The information analyzer 222 determines whether there are multiple central stations 16 classified into the first group (step S105). If the information analyzer 222 determines that there are not multiple central stations 16 classified into the first group (step S105—NO), traffic cannot be aggregated within the first group. Therefore, the management control device 20 ends the process of FIG. 7.

[0063] On the other hand, if the information analyzer 222 determines that there are multiple central stations 16 classified into the first group (step S105—YES), the information analyzer 222 determines the central station 16 to be added for the maximum predicted value (step S106). In FIG. 7, the central station 16 to be added is, for example, the reference central station 16 among the central stations 16 classified into the first group. The central station 16 to be added may be determined randomly, or may be the central station 16 with the smallest or largest predicted maximum value.

[0064] Next, the information analysis unit 222 determines the sum B of the maximum predicted value (step S107). The sum B in FIG. 7 is a central station 16 other than the sum A that belongs to the first group, for example, the central station 16 with the smallest maximum predicted value. The information analysis unit 222 sums the maximum predicted value of the sum A and the maximum predicted value of the sum B to obtain a total value T ｔｏｔａｌ is calculated (step S108).

[0065] The information analysis unit 222 calculates the total value T ｔｏｔａｌ and a threshold value. The threshold value in the first embodiment is a value for control judgment, and indicates the maximum traffic volume that the central station 16 can handle. The threshold value may be the same for each central station 16, or may be a different value for each central station 16. The threshold value may be calculated based on the cooperation information, or may be stored in advance by the information analysis unit 222 for each central station 16. The information analysis unit 222 may, for example, calculate the calculated total value T ｔｏｔａｌ is compared with the threshold value of the central office 16 corresponding to the sum A.

[0066] The information analysis unit 222 calculates the total value T ｔｏｔａｌ The information analysis unit 222 determines whether the total value T ｔｏｔａｌ is not greater than the threshold value (step S109-NO), the information analysis unit 222 calculates a new total value T by adding the predicted maximum values ​​of the central stations 16 that have not been added among the central stations 16 classified into the first group. ｔｏｔａｌ For example, the information analysis unit 222 calculates a new total value T by adding the smallest predicted maximum value among the predicted maximum values ​​of the central stations 16 classified into the first group that have not yet been added. ｔｏｔａｌ In addition, if there is a maximum predicted value of a central station 16 that has not been added among the central stations 16 classified in the first group, the information analysis unit 222 may add the value of the maximum predicted value other than the smallest maximum predicted value to obtain a new total value T ｔｏｔａｌ may be calculated.

[0067] After that, the information analysis unit 222 executes the process of step S109 again. In this case, the information analysis unit 222 calculates the newly calculated total value Tｔｏｔａｌ The information analysis unit 222 determines whether the total value T ｔｏｔａｌ is greater than the threshold value (step S109-YES), the information analysis unit 222 records the total value of the predicted maximum values ​​added up until the threshold value is exceeded in the storage unit 221 (step S111).

[0068] The information analyzer 222 then determines the central station 16 to be aggregated (step S112). Specifically, the information analyzer 222 determines the central station 16 to be aggregated from among the central stations 16 corresponding to the maximum predicted values ​​added up to the time before the threshold value was exceeded. For example, the information analyzer 222 may determine the central station 16 with the largest maximum predicted value among the central stations 16 corresponding to the maximum predicted values ​​added up to the time before the threshold value was exceeded as the central station 16 to be aggregated. Note that the information analyzer 222 may also determine the central station 16 with the largest traffic volume among the central stations 16 corresponding to the maximum predicted values ​​added up to the time before the threshold value was exceeded as the central station 16 to be aggregated.

[0069] As an example, if the central stations 16 corresponding to the respective predicted maximum values ​​added up before exceeding the threshold are the central stations 16-1 to 16-3, the information analysis unit 222 selects the central station 16 to be aggregated from among the central stations 16-1 to 16-3. Here, it is assumed that the central station 16-1 is selected as the aggregation destination.

[0070] Thereafter, the information analyzer 222 notifies the control unit 23 of control information including an optical path control instruction and a sleep instruction. The information analyzer 222 includes, for example, information indicating that the central stations from which the switching is to be performed are the central stations 16-2 and 16-3 and information indicating that the central station to which the switching is to be performed is the central station 16-1 in the optical path control instruction. The information analyzer 222 includes, for example, information indicating that the central stations to be put to sleep are the central stations 16-2 and 16-3, information indicating the wireless station 12 connected to the central station 16-2, and information indicating the wireless station 12 connected to the central station 16-3.

[0071] The optical path control unit 231 determines the central office 16 that will be the source of the optical path switching and the central office 16 that will be the destination of the optical path switching, based on the optical path control instructions included in the control information notified by the information analysis unit 222. Here, the optical path control unit 231 determines the central office 16-1 as the destination of the optical path switching, and determines the central offices 16-2 and 16-3 as the source of the optical path switching. The optical path control unit 231 transmits optical path control information to the transfer device 14, including information indicating the destination central office and source central office of the determined optical path switching (step S113).

[0072] As a result, the transfer device 14 switches the optical path route by switching the optical paths heading to the central stations 16-2 and 16-3 to those heading to the central station 16-1. Furthermore, the optical path control unit 231 transmits an optical path control instruction to the source central station of the determined optical path and the radio stations 12 connected to the source central station (step S114).

[0073] The sleep control unit 232 determines the wireless stations 12 and central stations 16 to be put to sleep based on the sleep instruction included in the control information notified by the information analysis unit 222. Here, it is assumed that the sleep control unit 232 has determined that the wireless stations 12 and central stations 16-2 connected to the central station 16-2, and the wireless stations 12 and central stations 16-3 connected to the central station 16-3, are to be put to sleep. The sleep control unit 232 transmits a sleep instruction to each of the determined devices (step S115). This allows the devices to transition to a sleep state.

[0074] 7 shows a configuration in which sleep control is performed after optical path switching control is performed, but the management control device 20 may perform optical path switching control after sleep control is performed. Furthermore, the processing of step S114 may be executed by the optical path switching function of the transfer device 14.

[0075] 8 is a flowchart showing an example of the flow of sleep wakeup processing (part 1) executed by the management control device 20 in the first embodiment. In FIG. 8, a case where sleep wakeup processing is performed on a central station 16 with a constant or regular traffic transition (a central station 16 belonging to the first group) is described. Here, traffic information is used as an example of the linkage information. In FIG. 8, the explanation is given assuming M=N=4. Here, it is assumed that the central stations 16-2 to 16-4 are in sleep mode.

[0076] The acquisition unit 211 acquires cooperation information from each of the central stations 16-1 to 16-4 (step S201). The acquisition unit 211 stores the acquired cooperation information for each central station 16 in the storage unit 221.

[0077] The information analysis unit 222 reads the cooperation information and the total value of the predicted maximum values ​​for each central station 16 stored in the storage unit 221 (step S202). The information analysis unit 222 calculates the traffic volume for each central station 16-1 to 16-4 based on the cooperation information for each central station 16 that has been read (step S203). The information analysis unit 222 determines whether the traffic volume of the central station 16 that was selected as the aggregation destination in the process of FIG. 7 exceeds the total value of the predicted maximum values ​​(step S204). If the information analysis unit 222 determines that the traffic volume of the central station 16 that was selected as the aggregation destination in the process of FIG. 7 does not exceed the total value of the predicted maximum values ​​(step S204-NO), the management control device 20 ends the process of FIG. 8.

[0078] On the other hand, if the information analyzer 222 determines that the traffic volume of the central station 16 selected as the aggregation destination in the process of FIG. 7 exceeds the total value of the predicted maximum values ​​(step S204—YES), the information analyzer 222 predicts the traffic volume of each of the central stations 16-1 to 16-4 based on the cooperation information for each central station 16 that it read (step S205). The information analyzer 222 then determines whether there is a central station 16 whose predicted traffic volume exceeds a threshold (step S206). The threshold used here may be the same as or different from the threshold used in FIG. 7. For example, the information analyzer 222 compares the traffic volume predicted for the central station 16-1 with the threshold for the central station 16-1 to determine whether the predicted traffic volume exceeds the threshold.

[0079] If the information analyzer 222 determines that there is no central station 16 whose predicted traffic volume exceeds the threshold (step S206—NO), the management and control device 20 terminates the processing of FIG. 8. On the other hand, if the information analyzer 222 determines that there is a central station 16 whose predicted traffic volume exceeds the threshold (step S206—YES), the information analyzer 222 determines the central station 16 to be woken from sleep mode (step S207). Here, it is assumed that the central station 16 whose traffic volume exceeds the threshold is central station 16-1. The information analyzer 222 identifies the other central station 16 whose traffic volume is the highest among the sleeping central stations 16-2 to 16-4, among the central stations 16-1. The following two methods can be used to identify this central station 16.

[0080] (Identification Method 1) Assuming that the terminal 11 will return its connection to the original central office 16, the information analysis unit 222 first calculates the traffic volume of the terminal 11 and calculates the traffic volume of the sleeping central office 16. The information analysis unit 222 then identifies the central office 16 with the largest traffic volume among the calculated traffic volumes as the other central office 16 with the largest traffic volume among the traffic volumes aggregated at the central office 16-1.

[0081] (Identification Method 2) First, the information analyzer 222 predicts the central office 16 to which the terminal 11 will connect after waking up from sleep mode based on the location of the terminal 11. Next, the information analyzer 222 calculates the traffic volume of the sleeping central office 16 based on the prediction result. Then, the information analyzer 222 identifies the central office 16 with the highest traffic volume among the calculated traffic volumes as the other central office 16 with the highest traffic volume among the traffic volumes aggregated at the central office 16-1.

[0082] Assume that the central station 16-2 is identified as the other central station 16 with the highest traffic volume by one of the above identification methods. The information analyzer 222 determines the identified central station 16-2 as the central station 16 to be woken up. The information analyzer 222 then notifies the control unit 23 of control information including an optical path control instruction and a sleep wake-up instruction. The information analyzer 222, for example, includes in the optical path control instruction information indicating that the central station to be switched to is the central station 16-2. The information analyzer 222, for example, includes information indicating that the central station to be woken up is the central station 16-2 and information indicating the wireless station 12 to be woken up.

[0083] The optical path control unit 231 determines the central office 16 that will be the control target for the optical path based on the optical path control instruction included in the control information notified by the information analysis unit 222. Here, the optical path control unit 231 determines the central office 16-2 as the control target for the optical path. The optical path control unit 231 transmits optical path control information including information indicating the central office that will be the control target for the determined optical path to the transfer device 14 (step S208). As a result, the transfer device 14 forms an optical path toward the central office 16-2.

[0084] The sleep control unit 232 determines the wireless stations 12 and the central station 16 to be released from sleep mode based on the release instruction included in the control information notified by the information analysis unit 222. Here, it is assumed that the sleep control unit 232 has determined that the wireless stations 12 connected to the central station 16-2 and the central station 16-2 are to be released from sleep mode. The sleep control unit 232 transmits a release instruction to each of the determined devices (step S209). This allows the devices to be released from sleep mode.

[0085] Fig. 9 is a flowchart showing an example of the flow of sleep processing (part 2) executed by the management control device 20 in the first embodiment. Fig. 9 explains a case where sleep processing is performed on a central station 16 with irregular traffic transitions (a central station 16 belonging to the second group). The processing in Fig. 9 is repeatedly executed at a predetermined cycle. Note that, here, traffic information will be used as an example of the cooperation information. In Fig. 9, the explanation will be given assuming M = N = 4. In Fig. 9, the same processes as in Fig. 7 are assigned the same reference numerals as in Fig. 7, and explanations thereof will be omitted.

[0086] After the processes in steps S101 to S104 are completed, the information analyzer 222 determines whether there are multiple central stations 16 classified in the second group (step S151). If the information analyzer 222 determines that there are not multiple central stations 16 classified in the second group (step S151-NO), traffic cannot be aggregated within the second group. Therefore, the management control device 20 ends the process in FIG. 9.

[0087] On the other hand, if the information analyzer 222 determines that there are multiple central stations 16 classified into the second group (step S151—YES), the information analyzer 222 determines the central station 16 to be added for the maximum predicted value (step S152). In FIG. 9 , the central station 16 to be added is, for example, the reference central station 16 among the central stations 16 classified into the second group. The central station 16 to be added may be determined randomly, or may be the central station 16 with the smallest or largest predicted maximum value.

[0088] Next, the information analysis unit 222 determines the sum B of the maximum predicted value (step S153). The sum B in FIG. 9 is a central station 16 other than the sum A that belongs to the second group, for example, the central station 16 with the smallest maximum predicted value. The information analysis unit 222 sums the maximum predicted value of the sum A and the maximum predicted value of the sum B to obtain a total value T ｔｏｔａｌ is calculated (step S154).

[0089] The information analysis unit 222 calculates the total value T ｔｏｔａｌThe information analysis unit 222 compares the calculated total value T ｔｏｔａｌ is compared with the threshold value of the central office 16 corresponding to the sum A.

[0090] The information analysis unit 222 calculates the total value T ｔｏｔａｌ The information analysis unit 222 determines whether the total value T ｔｏｔａｌ is not greater than the threshold value (step S155-NO), the information analysis unit 222 calculates a new total value T by adding the predicted maximum values ​​of the central stations 16 that have not been added among the central stations 16 classified into the second group. ｔｏｔａｌ For example, the information analysis unit 222 calculates a new total value T by adding the smallest predicted maximum value among the predicted maximum values ​​of the central stations 16 classified into the second group that have not yet been added. ｔｏｔａｌ In addition, if the maximum predicted value of a central station 16 that has not been added among the central stations 16 classified in the second group is a maximum predicted value, the information analysis unit 222 may add the value of the maximum predicted value other than the smallest maximum predicted value to obtain a new total value T ｔｏｔａｌ may be calculated.

[0091] Thereafter, the information analysis unit 222 executes the process of step S155 again. In this case, the information analysis unit 222 calculates the newly calculated total value T ｔｏｔａｌ The information analysis unit 222 determines whether the total value T ｔｏｔａｌ is greater than the threshold (step S155—YES), the information analyzer 222 determines the central station 16 to be aggregated (step S157). Specifically, the information analyzer 222 determines the central station 16 to be aggregated from among the central stations 16 corresponding to the maximum predicted values ​​added up to the time before the threshold was exceeded. For example, the information analyzer 222 may determine the central station 16 with the largest maximum predicted value as the central station 16 to be aggregated from among the central stations 16 corresponding to the maximum predicted values ​​added up to the time before the threshold was exceeded. Note that the information analyzer 222 may also determine the central station 16 with the largest traffic volume as the central station 16 to be aggregated from among the central stations 16 corresponding to the maximum predicted values ​​added up to the time before the threshold was exceeded.

[0092] As an example, if the central stations 16 corresponding to the respective predicted maximum values ​​added up before exceeding the threshold are the central stations 16-1 to 16-3, the information analysis unit 222 selects the central station 16 to be aggregated from among the central stations 16-1 to 16-3. Here, it is assumed that the central station 16-1 is selected as the aggregation destination.

[0093] Thereafter, the information analyzer 222 notifies the control unit 23 of control information including an optical path control instruction and a sleep instruction. The information analyzer 222 includes, for example, information indicating that the central stations from which the switching is to be performed are the central stations 16-2 and 16-3 and information indicating that the central station to which the switching is to be performed is the central station 16-1 in the optical path control instruction. The information analyzer 222 includes, for example, information indicating that the central stations to be put to sleep are the central stations 16-2 and 16-3, information indicating the wireless station 12 connected to the central station 16-2, and information indicating the wireless station 12 connected to the central station 16-3.

[0094] The optical path control unit 231 determines the central office 16 that will be the source and destination of the optical path switching, based on the optical path control instructions included in the control information notified by the information analysis unit 222. Here, the optical path control unit 231 determines the central office 16-1 as the destination of the optical path switching, and determines the central offices 16-2 and 16-3 as the source and destination of the optical path switching. The optical path control unit 231 transmits optical path control information to the transfer device 14, including information indicating the destination and source central offices of the determined optical paths (step S158).

[0095] As a result, the transfer device 14 switches the optical path route by switching the optical paths heading to the central stations 16-2 and 16-3 to those heading to the central station 16-1. Furthermore, the optical path control unit 231 transmits an optical path control instruction to the source central station of the determined optical path and the radio stations 12 connected to the source central station (step S159).

[0096] The sleep control unit 232 determines the wireless stations 12 and central stations 16 to be put to sleep based on the sleep instruction included in the control information notified by the information analysis unit 222. Here, it is assumed that the sleep control unit 232 has determined that the wireless stations 12 and central stations 16-2 connected to the central station 16-2, and the wireless stations 12 and central stations 16-3 connected to the central station 16-3, are to be put to sleep. The sleep control unit 232 then transmits a sleep instruction to each of the determined devices (step S160). This allows the devices to transition to a sleep state.

[0097] 9 shows a configuration in which sleep control is performed after optical path switching control is performed, but the management control device 20 may perform optical path switching control after sleep control is performed. Furthermore, the processing of step S159 may be executed by the optical path switching function of the transfer device 14.

[0098] FIG. 10 is a flowchart showing an example of the flow of sleep wakeup processing (part 2) executed by the management control device 20 in the first embodiment. FIG. 10 describes a case where sleep wakeup processing is performed on a central station 16 with irregular traffic transitions (a central station 16 belonging to the second group). Note that the explanation here takes traffic information as an example of the linkage information. In FIG. 10, the explanation will be given assuming M=N=4. In FIG. 10, the same processes as in FIG. 8 are assigned the same reference numerals as in FIG. 8, and explanations thereof will be omitted. Here, it is assumed that the central stations 16-2 to 16-4 are in sleep mode.

[0099] The acquisition unit 211 acquires the cooperation information from each of the central stations 16-1 to 16-4 (step S251). The acquisition unit 211 stores the acquired cooperation information for each central station 16 in the storage unit 221.

[0100] The information analyzer 222 reads the cooperation information for each central station 16 stored in the storage unit 221 (step S252). Based on the cooperation information for each central station 16, the information analyzer 222 predicts the traffic volume for each of the central stations 16-1 to 16-4 (step S253). The information analyzer 222 determines whether there is a central station 16 whose predicted traffic volume exceeds a threshold (step S254). The threshold used here may be the same as or different from the threshold used in FIG. 9 . For example, the information analyzer 222 compares the traffic volume predicted for the central station 16-1 with the threshold for the central station 16-1 to determine whether the predicted traffic volume exceeds the threshold.

[0101] If the information analyzer 222 determines that there is no central station 16 whose predicted traffic volume exceeds the threshold (step S254—NO), the management control device 20 terminates the processing of FIG. 10 . On the other hand, if the information analyzer 222 determines that there is a central station 16 whose predicted traffic volume exceeds the threshold (step S254—YES), the information analyzer 222 determines the central station 16 to be woken from sleep mode (step S255). Here, the central station 16 whose predicted traffic volume exceeds the threshold is assumed to be central station 16-1. The information analyzer 222 identifies the other central station 16 with the highest traffic volume among the sleeping central stations 16-2 to 16-4 among the central stations 16-1. The identification method can be either (Identification Method 1) or (Identification Method 2) described in the first embodiment.

[0102] Assume that the central station 16-2 is identified as the other central station 16 with the highest traffic volume by one of the above identification methods. The information analyzer 222 determines the identified central station 16-2 as the central station 16 to be woken up. The information analyzer 222 then notifies the control unit 23 of control information including an optical path control instruction and a sleep wake-up instruction. The information analyzer 222, for example, includes in the optical path control instruction information indicating that the central station to be switched to is the central station 16-2. The information analyzer 222, for example, includes information indicating that the central station to be woken up is the central station 16-2 and information indicating the wireless station 12 to be woken up.

[0103] The optical path control unit 231 determines the central office 16 that will be the control target for the optical path based on the optical path control instruction included in the control information notified by the information analysis unit 222. Here, the optical path control unit 231 determines the central office 16-2 as the control target for the optical path. The optical path control unit 231 transmits optical path control information including information indicating the central office that will be the control target for the determined optical path to the transfer device 14 (step S256). As a result, the transfer device 14 forms an optical path toward the central office 16-2.

[0104] The sleep control unit 232 determines the wireless stations 12 and the central station 16 to be released from sleep mode based on the release instruction included in the control information notified by the information analysis unit 222. Here, it is assumed that the sleep control unit 232 has determined that the wireless stations 12 connected to the central station 16-2 and the central station 16-2 are to be released from sleep mode. The sleep control unit 232 transmits a release instruction to each of the determined devices (step S257). This allows the devices to be released from sleep mode.

[0105] The mobile network system 100 configured as described above includes a collection unit 21 that acquires cooperation information from multiple central stations 16, and an analysis unit 22 that classifies the multiple central stations 16 into multiple groups based on the cooperation information, determines one or more central stations 16 to be subject to sleep control from among the multiple central stations 16 belonging to any of the classified groups, and executes sleep control on the one or more central stations 16 to be subject to sleep control. This allows the sleep control to be determined taking into account the cooperation information obtained from each central station 16. This makes it possible to increase the effect of power saving without degrading communication quality.

[0106] More specifically, the mobile network system 100 collects traffic information from each central station 16 as collaboration information. The information analyzer 222 predicts trends in traffic volume for each central station 16 based on the collected traffic information for each central station 16. The information analyzer 222 classifies each central station 16 into either a first group or a second group based on the predicted trends in traffic volume for each central station 16. The information analyzer 222 adds up the predicted maximum values ​​of multiple central stations 16 belonging to either the first group or the second group until the predicted maximum values ​​exceed a threshold. The information analyzer 222 determines a central station 16 to be aggregated from among the central stations 16 from which the predicted maximum values ​​were obtained, and determines the central stations 16 other than the aggregated central station 16 to be put into sleep mode. In this way, traffic aggregation is determined based on the traffic prediction results, and if traffic aggregation is possible, the traffic is aggregated to one central station 16. This allows some central stations 16 to go into sleep mode. This enhances the power saving effect.

[0107] In the mobile network system 100, when the traffic volume suddenly increases, the sleeping central office 16 is started up, so that the quality of communication is not degraded and power consumption can be saved.

[0108] In the mobile network system 100, when determining whether to wake up the multiple central stations 16 belonging to the first group, traffic prediction is performed only when the current traffic volume exceeds the total value of the maximum predicted traffic volume. In this way, the multiple central stations 16 belonging to the first group do not need to constantly predict traffic, which reduces power consumption.

[0109] (Variation 1 of the First Embodiment) In the above-described embodiment, a configuration has been shown in which the management and control device 20 performs optical path control processing and sleep control processing. Alternatively, a forwarding device may be configured to perform optical path control processing and sleep control processing. FIG. 11 is a diagram showing an example configuration of a mobile NW system 100a in Variation 1 of the first embodiment. The mobile NW system 100a includes multiple wireless stations 12-1 to 12-M, a forwarding device 14a, multiple central stations 16-1 to 16-N, and a management and control device 20a.

[0110] 11 , the transfer device 14a includes a control unit 23, while the management control device 20a does not include a control unit 23. The information analysis unit 222 of the management control device 20a notifies the transfer device 14a of control information. The information analysis unit 222 may notify the transfer device 14a of control information only when optical path control and sleep control are performed. The control unit 23 of the transfer device 14a performs optical path control processing and sleep control processing based on the control information notified from the management control device 20a.

[0111] The control unit 23 of the transfer device 14a includes an optical path control unit 231 and a sleep control unit 232. The optical path control unit 231 performs the same processing as the optical path control unit 231 described above. The sleep control unit 232 performs the same processing as the sleep control unit 232 described above.

[0112] (Variation 2 of the First Embodiment) In the above-described embodiment, a configuration has been shown in which the management control device 20 performs optical path control processing and sleep control processing. Alternatively, a configuration may be adopted in which the management control device performs sleep control processing and the forwarding device performs optical path control processing. FIG. 12 is a diagram showing an example configuration of a mobile NW system 100b in Variation 2 of the first embodiment. The mobile NW system 100b includes multiple radio stations 12-1 to 12-M, a forwarding device 14b, multiple central stations 16-1 to 16-N, and a management control device 20b.

[0113] 12 , the transfer device 14b includes a control unit 141. The control unit 141 includes an optical path control unit 231. The control unit 23b of the management control device 20b includes a sleep control unit 232. The information analysis unit 222 of the management control device 20b notifies the transfer device 14b of control information including information indicating the central station 16 that is the source of optical path switching and information indicating the central station 16 that is the destination of optical path switching, and notifies the control unit 23b of control information including information indicating the radio station 12 and central station 16 that are the targets of sleep control.

[0114] The information analysis unit 222 may notify the control information only when optical path control and sleep control are performed. The control unit 141 of the transfer device 14b performs optical path control processing based on the control information notified from the management control device 20b. The control unit 23b of the management control device 20b performs sleep control processing based on the control information notified from the information analysis unit 222. The optical path control unit 231 included in the control unit 141 of the transfer device 14b performs processing similar to that of the optical path control unit 231 described above.

[0115] (Variation 3 of First Embodiment) In the above-described embodiment, a configuration has been shown in which the management control device 20 performs optical path control processing and sleep control processing. In contrast, the optical path control processing and sleep control processing may be performed by different devices. FIG. 13 is a diagram showing a configuration example of a mobile NW system 100c in Variation 3 of the first embodiment. The mobile NW system 100c includes multiple radio stations 12-1 to 12-M, a forwarding device 14, multiple central stations 16-1 to 16-N, an optical transmission management control device 65, and a wireless transmission management control device 70. As shown in FIG. 13, the mobile NW system 100c includes the optical transmission management control device 65 and the wireless transmission management control device 70 instead of the management control device 20.

[0116] The optical transmission management control device 65 controls the optical transmission section. The optical transmission management control device 65 includes a collection unit 21, an analysis unit 22, and a control unit 66. The collection unit 21 and the analysis unit 22 perform the same processes as the collection unit 21 and the analysis unit 22 provided in the management control device 20 described above. The control unit 66 includes an optical path control unit 231. The optical path control unit 231 performs the same processes as the optical path control unit 231 provided in the management control device 20 described above.

[0117] The wireless transmission management control device 70 controls the wireless transmission section. The wireless transmission management control device 70 includes a control unit 71. The control unit 71 includes a sleep control unit 232. The sleep control unit 232 performs the same processing as the sleep control unit 232 included in the management control device 20 described above.

[0118] As an example, the information analyzer 222 of the optical transmission management control device 65 transmits control information including information indicating the radio stations 12 and the central station 16 that are to be subjected to sleep control to the radio transmission management control device 70. Based on the control information transmitted from the optical transmission management control device 65, the radio transmission management control device 70 causes the radio stations 12 and the central station 16 that are to be subjected to sleep control to put into sleep mode or to cancel sleep mode.

[0119] With this configuration, different processes such as optical path switching and sleep control can be performed by a plurality of devices, thereby reducing the amount of processing performed by a single device.

[0120] (Variation 4 of the First Embodiment) In the above-described embodiment, the configuration has been described in which the management control device 20 performs optical path control processing and sleep control processing. However, the optical path control processing and sleep control processing may be performed by different devices. FIG. 14 is a diagram showing an example configuration of a mobile NW system 100d in Variation 4 of the first embodiment. The mobile NW system 100d includes multiple radio stations 12-1 to 12-M, a forwarding device 14, multiple central stations 16-1 to 16-N, an optical transmission management control device 65, and a wireless transmission management control device 70. As shown in FIG. 14, the mobile NW system 100d includes the optical transmission management control device 65 and the wireless transmission management control device 70 instead of the management control device 20.

[0121] The optical transmission management control device 65 shown in Fig. 14 controls the optical transmission section. The optical transmission management control device 65 shown in Fig. 14 includes a control unit 66. The control unit 66 includes an optical path control unit 231. The optical path control unit 231 performs the same processing as the optical path control unit 231 included in the management control device 20 described above.

[0122] The wireless transmission management control device 70 shown in Fig. 14 controls the wireless transmission section. The wireless transmission management control device 70 shown in Fig. 14 includes a collection unit 21, an analysis unit 22, and a control unit 71. The collection unit 21 and the analysis unit 22 perform the same processes as the collection unit 21 and the analysis unit 22 provided in the management control device 20 described above. The control unit 71 includes a sleep control unit 232. The sleep control unit 232 performs the same processes as the sleep control unit 232 provided in the management control device 20 described above.

[0123] As an example, the information analyzer 222 of the wireless transmission management controller 70 transmits control information including information indicating the central office 16 from which the optical path is switched and information indicating the central office 16 to which the optical path is switched to, to the optical transmission management controller 65. The optical transmission management controller 65 switches the optical path based on the control information transmitted from the wireless transmission management controller 70.

[0124] With this configuration, different processes such as optical path switching and sleep control can be performed by a plurality of devices, thereby reducing the amount of processing performed by a single device.

[0125] (Fifth Modification of the First Embodiment) The mobile network system 100c shown in Fig. 13 may be configured as shown in Fig. 15. Fig. 15 is a diagram illustrating a configuration example of a mobile network system 100e in a fifth modification of the first embodiment. The mobile network system 100e includes a plurality of radio stations 12-1 to 2-M, a transfer device 14, a plurality of central stations 16-1 to 16-N, an optical transmission management controller 65, a radio transmission management controller 70, and an orchestrator 75. As shown in Fig. 15, the mobile network system 100e further includes the orchestrator 75 in addition to the mobile network system 100c.

[0126] The orchestrator 75 is provided above the optical transmission management control device 65 and the wireless transmission management control device 70. The orchestrator 75 transfers signals, for example, between the optical transmission management control device 65 and the wireless transmission management control device 70. The orchestrator 75 includes a signal transfer unit 751. The signal transfer unit 751 receives control information addressed to the wireless transmission management control device 70 and transmitted from the optical transmission management control device 65. The signal transfer unit 751 transfers the received control information to the wireless transmission management control device 70.

[0127] The optical transmission management control device 65 performs the same processing as the optical transmission management control device 65 shown in Fig. 13 except that it transmits control information addressed to the wireless transmission management control device 70 to the orchestrator 75. The wireless transmission management control device 70 performs the same processing as the wireless transmission management control device 70 shown in Fig. 13 except that it receives control information from the orchestrator 75.

[0128] (Variation 6 of the First Embodiment) The mobile NW system 100d shown in Fig. 14 may be configured as shown in Fig. 16. Fig. 16 is a diagram showing a configuration example of a mobile NW system 100f in Variation 6 of the first embodiment. The mobile NW system 100f includes a plurality of radio stations 12-1 to 12-M, a transfer device 14, a plurality of central stations 16-1 to 16-N, an optical transmission management controller 65, a radio transmission management controller 70, and an orchestrator 75. As shown in Fig. 16, the mobile NW system 100f further includes the orchestrator 75 in addition to the mobile NW system 100d.

[0129] The orchestrator 75 is provided above the optical transmission management control device 65 and the wireless transmission management control device 70. The orchestrator 75 transfers signals between the optical transmission management control device 65 and the wireless transmission management control device 70. The orchestrator 75 includes a signal transfer unit 751. The signal transfer unit 751 receives control information addressed to the optical transmission management control device 65 and transmitted from the wireless transmission management control device 70. The signal transfer unit 751 transfers the received control information to the optical transmission management control device 65.

[0130] The optical transmission management control device 65 performs the same processing as the optical transmission management control device 65 shown in Fig. 14 except that it receives control information from the orchestrator 75. The wireless transmission management control device 70 performs the same processing as the wireless transmission management control device 70 shown in Fig. 14 except that it transmits control information addressed to the optical transmission management control device 65 to the orchestrator 75.

[0131] (Seventh Modification of the First Embodiment) The mobile network system 100 may be configured as shown in FIG. 17 . FIG. 17 is a diagram illustrating a configuration example of a mobile network system 100g in a seventh modification of the first embodiment. The mobile network system 100g includes a plurality of radio stations 12-1 to 12-M, a forwarding device 14, a plurality of central stations 16-1 to 16-N, an optical transmission management controller 65, and a radio transmission management controller 70. As shown in FIG. 17 , the mobile network system 100g includes the optical transmission management controller 65 and the radio transmission management controller 70 instead of the management controller 20. The mobile network system 100g is configured such that the optical transmission management controller 65 and the radio transmission management controller 70 each receive cooperation information from each central station 16.

[0132] The optical transmission management control device 65 shown in Fig. 17 includes a collection unit 67, an analysis unit 68, and a control unit 66. The collection unit 67 includes an acquisition unit 671. The acquisition unit 671 performs the same processing as the acquisition unit 211 included in the management control device 20 described above. The analysis unit 68 includes a storage unit 681 and an information analysis unit 682. The storage unit 681 and the information analysis unit 682 perform the same processing as the storage unit 221 and the information analysis unit 222 included in the management control device 20 described above. The control unit 66 includes an optical path control unit 231. The optical path control unit 231 performs the same processing as the optical path control unit 231 included in the management control device 20 described above.

[0133] The wireless transmission management control device 70 includes a collection unit 72, an analysis unit 73, and a control unit 71. The collection unit 72 includes an acquisition unit 721. The acquisition unit 721 performs the same processing as the acquisition unit 211 included in the management control device 20 described above. The analysis unit 73 includes a storage unit 731 and an information analysis unit 732. The storage unit 731 and the information analysis unit 732 perform the same processing as the storage unit 221 and the information analysis unit 222 included in the management control device 20 described above. The control unit 71 includes a sleep control unit 232. The sleep control unit 232 performs the same processing as the sleep control unit 232 included in the management control device 20 described above.

[0134] The timing at which the optical transmission management control device 65 performs the optical path control processing and the timing at which the wireless transmission management control device 70 performs the sleep control processing may be timings determined by each device. The mobile NW system 100g may include an orchestrator 75 that controls the optical transmission management control device 65 and the wireless transmission management control device 70, and the orchestrator 75 may synchronize the timing at which the optical transmission management control device 65 performs the optical path control processing and the timing at which the wireless transmission management control device 70 performs the sleep control processing.

[0135] (Variation 8 of the First Embodiment) In the above-described configuration, the sleep control unit 232 puts both the sleep target wireless station 12 and the central station 16 to sleep, but the sleep control unit 232 may put either the sleep target wireless station 12 or the central station 16 to sleep. Furthermore, in the above-described configuration, the sleep control unit 232 wakes up both the sleep target wireless station 12 and the central station 16 to wake up, but the sleep control unit 232 may wake up either the sleep target wireless station 12 or the central station 16 to wake up.

[0136] (Ninth Modification of the First Embodiment) The cooperation information may include, for example, information regarding the number of terminals 11 accommodated by each central station 16 (hereinafter referred to as the "number of accommodated terminals"). The cooperation information may include, for example, information regarding the processing load of the central station 16 (hereinafter referred to as the "processing load information"). The processing load information may be, for example, information regarding the memory usage rate of the central station 16 or information regarding the usage rate of the CPU (Central Processing Unit). The cooperation information may include information regarding the communication quality of the terminals 11 connected to each central station 16 (hereinafter referred to as the "communication quality information"). The communication quality information may be, for example, a modulation and coding scheme (MCS), a reference signal received power (RSRP), a reference signal received quality (RSRQ), a signal-to-noise ratio (SINR), packet delay, location information, etc.

[0137] When the cooperation information includes information about the number of accommodated terminals, the information analysis unit 222 may use the information about the number of accommodated terminals to select a sleep control target (for example, a sleep target or a sleep release target). In this configuration, the information analysis unit 222 may select a central station to be subject to sleep control, in the same way as when traffic information is used.

[0138] First, the information analysis unit 222 predicts the number of accommodated terminals for each central station 16 over a certain period of time using information about the past number of accommodated terminals collected from each central station 16. The information analysis unit 222 classifies each central station 16 into multiple groups based on the predicted number of accommodated terminals. For example, the information analysis unit 222 classifies each central station 16 into either a first group or a second group. In this case, the first group is a group for which the predicted number of accommodated terminals is determined to have a constant or regular change in the number of accommodated terminals. The second group is a group for which the predicted number of accommodated terminals is determined to have a constant or regular change in the number of accommodated terminals.

[0139] The information analyzer 222 then aggregates traffic among the multiple central stations 16 belonging to the first group. For example, the information analyzer 222 selects the largest number of accommodated terminals among the predicted numbers of accommodated terminals from each of the multiple central stations 16 belonging to the first group. As an example, if the multiple central stations 16 belonging to the first group are central stations 16-1 to 16-3, the information analyzer 222 selects the value that maximizes the number of accommodated terminals in the predicted results for the number of accommodated terminals for central station 16-1, the value that maximizes the number of accommodated terminals in the predicted results for the number of accommodated terminals for central station 16-2, and the value that maximizes the number of accommodated terminals in the predicted results for the number of accommodated terminals for central station 16-3. Hereinafter, the value that maximizes the number of accommodated terminals in the predicted results for the number of accommodated terminals is referred to as the "maximum predicted number of terminals."

[0140] The information analysis unit 222 then sums up the maximum predicted number of terminals for each of the selected central stations 16-1, 16-2, and 16-3 in order. In this case, the information analysis unit 222 may sum up the maximum predicted number of terminals in ascending order, or in descending order. By summing up in ascending order, it is possible to consolidate a larger number of central stations 16, and in this case, it is possible to transition many central stations 16 to a sleep state. As a result, it is possible to improve the power saving effect. The information analysis unit 222 sums up the maximum predicted number of terminals up to the point where the sum does not exceed the threshold.

[0141] If the total exceeds the threshold, the information analysis unit 222 selects a sleep target based on the maximum predicted number of terminals added up to the time before the threshold is exceeded. For example, the information analysis unit 222 selects the central station 16 with the maximum predicted number of terminals added up to the time before the threshold is exceeded as a sleep candidate. Similarly, if there are no more maximum predicted numbers of terminals to add up, the information analysis unit 222 selects a sleep target based on the maximum predicted number of terminals added up to the time before the threshold is exceeded. Before selecting a sleep target, the information analysis unit 222 determines a central station 16 to be used as an aggregation destination from among the sleep candidate targets. For example, the information analysis unit 222 may determine the central station 16 with the largest number of terminals among the sleep candidate targets as the aggregation destination central station 16, or the central station 16 with the largest maximum predicted number of terminals as the aggregation destination central station 16, or may determine a central station 16 based on a predetermined priority order. The information analysis unit 222 then determines a central station 16 other than the aggregation destination from among the sleep candidate targets as the sleep target.

[0142] When the cooperation information includes processing load information and communication quality information, the information analysis unit 222 may select a sleep control target (for example, a sleep target or a sleep release target) using the processing load information or communication quality information in addition to the traffic information. For example, when selecting a sleep control target using communication quality information in addition to traffic information, the information analysis unit 222 determines that sleep control is to be performed when a condition based on traffic information is satisfied and a condition based on communication quality information is satisfied. The condition based on traffic information is the threshold and the total value shown in the embodiment. ｔｏｔａｌThe condition based on communication quality information may be, for example, a condition based on whether the path after sleep is feasible (e.g., whether quality degradation occurs). In this case, even if the information analyzer 222 determines the central office 16 to be put into sleep mode and the central office 16 to be controlled as an optical path based on a condition based on traffic information, quality may still degrade after the path is switched. Therefore, even if the information analyzer 222 determines the central office 16 to be put into sleep mode and the central office 16 to be controlled as an optical path based on a condition based on traffic information, the information analyzer 222 may not execute sleep mode if quality degradation occurs on the path after optical path control.

[0143] Second Embodiment In a second embodiment, a configuration will be described in which a base station is provided in which a wireless station, a remote station, and a central station are integrated.

[0144] (Outline of the Second Embodiment) FIG. 18 is a diagram for explaining an outline of the processing of the mobile network system in the second embodiment. First, the overall configuration of the mobile network system in the second embodiment will be explained. The mobile network system in the second embodiment is an example of a communication system. The mobile network system in the second embodiment is, for example, 5G. The mobile network system in the second embodiment includes a transfer device 14, a plurality of base stations 17-1 to 17-M, one or more servers 19, and a management control device 20.

[0145] Optical fibers that transmit optical signals are used to connect each base station 17 and the transfer device 14, and between the transfer device 14 and the server 19. Optical fibers or electrical lines that transmit electrical signals are used to connect the transfer device 14 and the management control device 20, and between each base station 17 and the management control device 20.

[0146] 18 shows an example in which there are M base stations 17 and one server 19. There is no particular limit to the number of base stations 17 and servers 19. Note that although a plurality of transfer devices 14 may be provided, the following description will be given taking the case of one device as an example.

[0147] Each base station 17 is a device that integrates a radio station (RU), a central unit (DU), and an aggregation station (CU: Central Unit) in 5G. The base station 17 has one or more antennas and performs wireless communication with one or more terminals 11 located within its communication area. For example, each base station 17 transmits signals transmitted from one or more terminals 11 to a server 19 via a transfer device 14. Each base station 17 transmits signals received via the transfer device 14 to one or more terminals 11. The base station 17 transmits cooperation information to a management control device 20. The base station 17 transmits signals received via the transfer device 14 to the terminal 11.

[0148] If the base station 17 is equipped with multiple antennas, the base station 17 may perform wireless communication with one or more terminals 11 using beamforming. The base station 17 transitions to a sleep state in accordance with a sleep instruction transmitted from the management control device 20. The base station 17 releases the sleep state in accordance with a sleep release instruction transmitted from the management control device 20. Furthermore, the base station 17 switches the optical path in accordance with an optical path control instruction transmitted from the management control device 20. For example, upon receiving an optical path control instruction, the base station 17 stops setting up an optical path with the transfer device 14. Stopping the setting up of an optical path in the base station 17 means not irradiating light on the path from the base station 17 to the transfer device 14 (stopping optical irradiation). The base station 17 is one aspect of a communication station.

[0149] The transfer device 14 in the second embodiment is provided between the base station 17 and the server 19. The transfer device 14 switches the optical path in accordance with optical path control information for the optical path transmitted from the management control device 20. The transfer device 14 switches the connection between the base station 17 and the server 19 by switching the optical path. For example, when the transfer device 14 receives optical path control information for the optical path transmitted from the management control device 20, it executes switching so that the optical path is connected between the base station 17, which is the switching destination of the optical path, and the server 19.

[0150] The coordination information in the second embodiment includes, for example, traffic information of each base station 17. The traffic information is the same as that in the first embodiment. Furthermore, the base station 17 controls the optical path in accordance with an optical path control instruction transmitted from the management control device 20. When the base station 17 receives an optical path switching start instruction after receiving the optical path control instruction, it stops setting up the optical path between the base station 17 and the transfer device 14.

[0151] The management control device 20 in the second embodiment is a device that manages the entire mobile NW system. The management control device 20 acquires cooperation information from each base station 17. When acquiring cooperation information from each base station 17, the management control device 20 uses a cooperation interface. The management control device 20 determines whether optical path control and sleep control are necessary based on the acquired cooperation information. When the management control device 20 determines that optical path control and sleep control are necessary, it performs optical path control processing and sleep control processing. The optical path control processing in the second embodiment is processing that switches optical paths between the base station 17 and the forwarding device 14 and generates optical paths. The sleep control processing in the second embodiment is processing that puts the base station 17 that is the target of sleep control into sleep mode or releases sleep mode.

[0152] Next, an overview of the processing of the mobile network system will be described. The upper diagram of Fig. 18 shows the connection state of the mobile network system before switching the optical path, and the lower diagram of Fig. 18 shows the connection state of the mobile network system after switching the optical path. The upper diagram of Fig. 18 shows an example in which terminals 11-1 and 11-2 are connected to base station 17-1, base station 17-1 is connected to server 19 via transfer device 14, terminals 11-3 and 11-4 are connected to base station 17-M, and base station 17-M is connected to server 19 via transfer device 14.

[0153] The management control device 20 determines, based on the cooperation information collected from each base station 17, that sleep control is necessary when one base station 17 can accommodate the traffic of other base stations 17. That is, based on the cooperation information collected from each base station 17, the management control device 20 performs optical path control processing and sleep control processing when one base station 17 can accommodate the traffic of other base stations 17. For example, the management control device 20 performs optical path control processing and sleep control processing in base station 17-M when all of the traffic of base station 17-1 can be accommodated. In this way, by accommodating the traffic of other base stations 17 in one base station 17, it is possible to transition the other base stations 17 that no longer have traffic to a sleep state.

[0154] When performing optical path control processing, the management control device 20 transmits information about the optical path switching destination to the transfer device 14 and instructs the base station 17 to which the optical path is to be switched to switch the optical path. Note that, because the connection destination of the terminal 11 changes due to the optical path switching, the management control device 20 may instruct the base station 17 to which the optical path is to be switched to change the connection. The transfer device 14 switches the optical path of the base station 17 in accordance with the instruction from the management control device 20. After completing the optical path switching, the transfer device 14 notifies the management control device 20 of the completion of the optical path switching. The base station to which the optical path is to be switched switches the optical path in accordance with the instruction from the management control device 20.

[0155] When the optical path control process is completed, the management control device 20 transmits a sleep permission notification to the base station 17 that is to be transitioned to the sleep state. As a result, the base station 17 that is to be transitioned to the sleep state transitions to the sleep state. Note that in the above explanation, an example was given of a configuration in which the management control device 20 performs the sleep control process after the optical path control process is completed, but the management control device 20 may also perform the optical path control process after the sleep control process is completed. In the following explanation, an example is given of a configuration in which the sleep control process is performed after the optical path control process is completed. The lower diagram of Figure 18 shows an example in which terminals 11-1 to 11-4 are connected to base station 17-M and base station 17-1 is transitioning to the sleep state.

[0156] (Details of the Second Embodiment) Fig. 19 is a diagram showing an example of the configuration of a mobile NW system 200 in the second embodiment. The mobile NW system 200 in the second embodiment includes a transfer device 14, multiple base stations 17-1 to 17-M, one or more servers 19, and a management control device 20. The transfer device 14, the base stations 17, and the server 19 have been described in Fig. 18, so description thereof will be omitted.

[0157] The management control device 20 includes a collection unit 21, an analysis unit 22, and a control unit 23. The acquisition unit 211 collects cooperation information from each base station 17 at a predetermined period or at any timing. For example, the acquisition unit 211 collects traffic information of each base station 17 as cooperation information.

[0158] The analysis unit 22 includes a storage unit 221 and an information analysis unit 222. The storage unit 221 records the collected linkage information in a predetermined storage device. Furthermore, the storage unit 221 stores the total value of the predicted maximum values ​​calculated by the information analysis unit 222.

[0159] The information analysis unit 222 analyzes the state of communication between each base station 17 and the terminal 11 based on the cooperation information. Specifically, the information analysis unit 222 determines whether optical path control and sleep control are necessary based on the cooperation information. The information analysis unit 222 predicts the traffic volume of each base station 17 based on the cooperation information stored in the storage unit 221, for example. The information analysis unit 222 classifies each base station 17 into either a first group or a second group based on the traffic volume prediction result. Then, the information analysis unit 222 determines whether optical path control and sleep control are necessary for each classified group.

[0160] The information analysis unit 222 determines that optical path control and sleep control are necessary, for example, when all of the terminals 11 accommodated by one base station 17 belonging to the first group can be accommodated by any of the base stations 17 belonging to the first group. Similarly, the information analysis unit 222 determines that optical path control and sleep control are necessary, for example, when all of the terminals 11 accommodated by one base station 17 belonging to the second group can be accommodated by any of the base stations 17 belonging to the second group.

[0161] When the information analysis unit 222 determines that optical path control and sleep control are necessary, it notifies the control unit 23 of control information including an optical path control instruction and a sleep instruction. The optical path control instruction in the second embodiment is an instruction to request switching of the optical path, and includes, for example, information indicating the base station 17 that is the source of the optical path switching and information indicating the base station 17 that is the destination of the optical path switching. The sleep instruction in the second embodiment is an instruction to execute sleep, and includes, for example, information indicating the base station 17 that is the sleep target. The method of selecting the sleep target in the information analysis unit 222 is the same as in the first embodiment.

[0162] Furthermore, when the traffic volume of a certain base station 17 exceeds a threshold, the information analysis unit 222 determines that optical path control and sleep control are necessary. In this case, the information analysis unit 222 notifies the control unit 23 of control information including an optical path control instruction and a sleep release instruction. The sleep release instruction in the second embodiment is an instruction to execute sleep release, and includes, for example, information indicating the base station 17 to be released from sleep. The method of selecting the base station to be released from sleep in the information analysis unit 222 is the same as in the first embodiment.

[0163] The control unit 23 includes an optical path control unit 231 and a sleep control unit 232. The optical path control unit 231 determines the base station 17 that will be the source of optical path switching and the base station 17 that will be the destination of optical path switching based on the analysis results of the information analysis unit 222. For example, the optical path control unit 231 determines the base station 17 that will be the source of optical path switching based on information that indicates the base station 17 that will be the source of optical path switching, which is included in the control information notified from the information analysis unit 222. For example, the optical path control unit 231 determines the base station 17 that will be the destination of optical path switching based on information that indicates the base station 17 that will be the destination of optical path switching, which is included in the control information notified from the information analysis unit 222.

[0164] The optical path control unit 231 transmits optical path control information including information indicating the base station 17 to which the determined optical path is to be switched to, to the transfer device 14. As a result, the optical path control unit 231 instructs the transfer device 14 to switch the optical path. Furthermore, the optical path control unit 231 transmits an optical path control instruction to the base station 17 to which the determined optical path is to be switched.

[0165] Based on the analysis result of the information analysis unit 222, the sleep control unit 232 causes the base station 17 that is the target of sleep control to execute sleep or cancel sleep.

[0166] Fig. 20 is a flowchart showing an example of the flow of sleep processing (part 1) executed by the management control device 20 in the second embodiment. Fig. 20 explains a case where sleep processing is performed on a base station 17 (a base station 17 belonging to the first group) where traffic transitions are constant or regular. The processing in Fig. 20 is repeatedly executed at a predetermined cycle. Here, traffic information is used as an example of cooperation information. In Fig. 20, the explanation is given assuming M=4.

[0167] The acquisition unit 211 acquires cooperation information from each of the base stations 17-1 to 17-4 (step S301). For example, the acquisition unit 211 may collect information once per unit time as a predetermined cycle, or may collect information at any timing. The acquisition unit 211 stores the acquired cooperation information for each base station 17 in the storage unit 221 (step S302).

[0168] The information analysis unit 222 predicts the traffic trends for each of the base stations 17-1 to 17-4 over a certain period of time (step S303) based on the cooperation information for each base station 17 stored in the storage unit 221. Thereafter, the information analysis unit 222 classifies the base stations 17-1 to 17-4 into either a first group or a second group based on the predicted traffic trends (step S304).

[0169] The information analysis unit 222 determines whether there are multiple base stations 17 classified into the first group (step S305). If the information analysis unit 222 determines that there are not multiple base stations 17 classified into the first group (step S305-NO), traffic cannot be aggregated within the first group. Therefore, the management control device 20 ends the processing of FIG. 20.

[0170] On the other hand, if the information analysis unit 222 determines that there are multiple base stations 17 classified into the first group (step S305—YES), the information analysis unit 222 determines an addition target A of the maximum predicted value (step S306). Addition target A in FIG. 20 is, for example, a reference base station 17 among the base stations 17 classified into the first group. Addition target A may be determined randomly, or may be the base station 17 with the smallest or largest predicted maximum value.

[0171] Next, the information analysis unit 222 determines the addition target B of the predicted maximum value (step S307). The addition target B in FIG. 20 is the base station 17 other than the addition target A that belongs to the first group, for example, the base station 17 with the smallest predicted maximum value. The information analysis unit 222 adds up the predicted maximum value of the addition target A and the predicted maximum value of the addition target B to determine the total value T ｔｏｔａｌ is calculated (step S308).

[0172] The information analysis unit 222 calculates the total value T ｔｏｔａｌand a threshold value. The threshold value in the second embodiment is a value for control judgment, and indicates the maximum traffic volume that the base station 17 can handle. The threshold value may be the same for each base station 17, or may be a different value for each base station 17. The threshold value may be calculated based on cooperation information, or may be stored in advance by the information analysis unit 222 for each base station 17. The information analysis unit 222 compares the calculated total value T ｔｏｔａｌ is compared with the threshold value of the base station 17 corresponding to the addition target A.

[0173] The information analysis unit 222 calculates the total value T ｔｏｔａｌ The information analysis unit 222 determines whether the total value T ｔｏｔａｌ is not greater than the threshold (step S309-NO), the information analysis unit 222 adds the predicted maximum values ​​of the base stations 17 classified into the first group that have not been added, to obtain a new total value T ｔｏｔａｌ For example, the information analysis unit 222 calculates a new total value T by adding the smallest predicted maximum value among the predicted maximum values ​​of the base stations 17 classified into the first group that have not yet been added. ｔｏｔａｌ In addition, if the maximum predicted value of a base station 17 that has not been added among the base stations 17 classified in the first group is a maximum predicted value, the information analysis unit 222 may add the value of the maximum predicted value other than the smallest maximum predicted value to obtain a new total value T ｔｏｔａｌ may be calculated.

[0174] After that, the information analysis unit 222 executes the process of step S309 again. In this case, the information analysis unit 222 calculates the newly calculated total value T ｔｏｔａｌ The information analysis unit 222 determines whether the total value T ｔｏｔａｌ is greater than the threshold value (step S309-YES), the information analysis unit 222 records the total value of the predicted maximum values ​​added up until the threshold value is exceeded in the storage unit 221 (step S311).

[0175] Furthermore, the information analysis unit 222 determines the base station 17 to be aggregated (step S312). Specifically, the information analysis unit 222 determines the base station 17 to be aggregated from among the base stations 17 corresponding to the respective predicted maximum values ​​added up before the threshold value is exceeded. For example, the information analysis unit 222 may determine the base station 17 with the largest predicted maximum value among the base stations 17 corresponding to the respective predicted maximum values ​​added up before the threshold value is exceeded as the base station 17 to be aggregated. Note that the information analysis unit 222 may determine the base station 17 with the largest traffic volume among the base stations 17 corresponding to the respective predicted maximum values ​​added up before the threshold value is exceeded as the base station 17 to be aggregated.

[0176] As an example, if the central stations 16 corresponding to the maximum predicted values ​​added up before exceeding the threshold are the base stations 17-1 to 17-3, the information analysis unit 222 determines the base station 17 to be aggregated from among the base stations 17-1 to 17-3. Here, it is assumed that the base station 17-1 is determined to be the aggregation destination.

[0177] Thereafter, the information analysis unit 222 notifies the control unit 23 of control information including an optical path control instruction and a sleep instruction. The information analysis unit 222 includes, for example, information indicating that the base stations from which the switching is to be performed are base stations 17-2 and 17-3 and information indicating that the base station to which the switching is to be performed is base station 17-1 in the optical path control instruction. The information analysis unit 222 includes, for example, information indicating that the base stations to be put to sleep are base stations 17-2 and 17-3.

[0178] The optical path control unit 231 determines the base station 17 that will be the source of optical path switching and the base station 17 that will be the destination of optical path switching, based on the optical path control instructions included in the control information notified from the information analysis unit 222. Here, the optical path control unit 231 determines base station 17-1 as the destination of optical path switching, and determines base stations 17-2 and 17-3 as the source of optical path switching. The optical path control unit 231 transmits optical path control information including information indicating the destination base station and source base station of the determined optical path to the transfer device 14 (step S313).

[0179] As a result, the transfer device 14 switches the optical path route by switching the optical paths heading toward the base stations 17-2 and 17-3 to head toward the base station 17-1. Furthermore, the optical path control unit 231 transmits an optical path control instruction to the switching source base station of the determined optical path (step S314).

[0180] The sleep control unit 232 determines the base station 17 to be put to sleep based on the sleep instruction included in the control information notified from the information analysis unit 222. Here, the sleep control unit 232 determines base station 17-2 and base station 17-3 as the sleep targets. The sleep control unit 232 transmits a sleep instruction to each determined device (step S315). This allows the sleep target devices to transition to a sleep state.

[0181] 20 shows a configuration in which sleep control is performed after optical path switching control is performed, but the management control device 20 may perform optical path switching control after sleep control is performed. Furthermore, the processing of step S314 may be executed by the optical path switching function of the transfer device 14.

[0182] Fig. 21 is a flowchart showing an example of the flow of sleep release processing (part 1) executed by the management control device 20 in the second embodiment. Fig. 21 explains a case where sleep release processing is performed on a base station 17 (a base station 17 belonging to the first group) where traffic transitions are constant or regular. Note that the explanation here takes traffic information as an example of cooperation information. In Fig. 21, the explanation is given assuming M=4. Here, it is assumed that base stations 17-2 to 17-4 are in sleep mode.

[0183] The acquisition unit 211 acquires cooperation information from each of the base stations 17-1 to 17-4 (step S401). The acquisition unit 211 stores the acquired cooperation information for each base station 17 in the storage unit 221.

[0184] The information analysis unit 222 reads the cooperation information of each base station 17 stored in the storage unit 221 and the total value of the predicted maximum values ​​(step S402). The information analysis unit 222 calculates the traffic volume of each base station 17-1 to 17-4 based on the cooperation information for each base station 17 that has been read (step S403). The information analysis unit 222 determines whether the traffic volume of the base station 17 that has become the aggregation destination in the processing of FIG. 20 exceeds the total value of the predicted maximum values ​​(step S404). If the information analysis unit 222 determines that the traffic volume of the base station 17 that has become the aggregation destination in the processing of FIG. 20 does not exceed the total value of the predicted maximum values ​​(step S404-NO), the management control device 20 ends the processing of FIG. 21.

[0185] On the other hand, if the information analysis unit 222 determines that the traffic volume of the base station 17 selected as the aggregation destination in the processing of FIG. 20 exceeds the total value of the predicted maximum values ​​(step S404—YES), the information analysis unit 222 predicts the traffic volume of each of the base stations 17-1 to 17-4 based on the read cooperation information for each base station 17 (step S405). The information analysis unit 222 then determines whether there is a base station 17 whose predicted traffic volume exceeds a threshold (step S406). The threshold used here may be the same as or different from the threshold used in FIG. 20. For example, the information analysis unit 222 compares the traffic volume predicted for base station 17-1 with the threshold for base station 17-1 to determine whether the predicted traffic volume exceeds the threshold.

[0186] If the information analysis unit 222 determines that there is no base station 17 whose predicted traffic volume exceeds the threshold (step S406—NO), the management control device 20 terminates the processing of FIG. 21. On the other hand, if the information analysis unit 222 determines that there is a base station 17 whose predicted traffic volume exceeds the threshold (step S406—YES), the information analysis unit 222 determines the base station 17 to be released from sleep mode (step S407). Here, it is assumed that the base station 17 whose traffic volume exceeds the threshold is base station 17-1. The information analysis unit 222 identifies the other base station 17 with the highest traffic volume among the traffic volumes aggregated at base station 17-1 from among the sleeping base stations 17-2 to 17-4. As the identification method, either (Identification Method 1) or (Identification Method 2) described in the first embodiment is used.

[0187] It is assumed that base station 17-2 is identified as the other base station 17 with the highest traffic volume by any of the above identification methods. The information analysis unit 222 determines the identified base station 17-2 as the base station 17 to be released from sleep mode. Thereafter, the information analysis unit 222 notifies the control unit 23 of control information including an optical path control instruction and a sleep release instruction. For example, the information analysis unit 222 includes, in the optical path control instruction, information indicating that the base station to be switched to is base station 17-2. For example, the information analysis unit 222 includes information indicating that the base station to be released from sleep mode is base station 17-2.

[0188] The optical path control unit 231 determines the base station 17 to be the control target of the optical path based on the optical path control instruction included in the control information notified from the information analysis unit 222. Here, the optical path control unit 231 determines the base station 17-2 as the control target of the optical path. The optical path control unit 231 transmits optical path control information including information indicating the base station to be controlled for the determined optical path to the transfer device 14 (step S408). As a result, the transfer device 14 forms an optical path directed toward the base station 17-2.

[0189] The sleep control unit 232 determines the base station 17 to be released from sleep mode based on the sleep release instruction included in the control information notified by the information analysis unit 222. Here, the sleep control unit 232 determines the base station 17-2 as the base station to be released from sleep mode. The sleep control unit 232 transmits the sleep release instruction to the determined base station 17-2 (step S409). This allows the base station 17-2 to be released from sleep mode.

[0190] Fig. 22 is a flowchart showing an example of the flow of sleep processing (part 2) executed by the management control device 20 in the second embodiment. Fig. 22 describes a case where sleep processing is performed on a base station 17 with irregular traffic transitions (a base station 17 belonging to the second group). The processing in Fig. 22 is repeatedly executed at a predetermined cycle. Note that, here, traffic information will be used as an example of cooperation information. In Fig. 22, the description will be given assuming M = N = 4. In Fig. 22, processing similar to that in Fig. 20 will be assigned the same reference numerals as in Fig. 20, and description thereof will be omitted.

[0191] After the processing from step S301 to step S304 is completed, the information analysis unit 222 determines whether there are multiple base stations 17 classified into the second group (step S351). If the information analysis unit 222 determines that there are not multiple base stations 17 classified into the second group (step S351-NO), traffic cannot be aggregated within the second group. Therefore, the management control device 20 ends the processing of FIG. 22.

[0192] On the other hand, if the information analysis unit 222 determines that there are multiple base stations 17 classified into the second group (step S351—YES), the information analysis unit 222 determines an addition target A of the maximum predicted value (step S352). Addition target A in FIG. 22 is, for example, a reference base station 17 among the base stations 17 classified into the second group. Addition target A may be determined randomly, or may be the base station 17 with the smallest or largest predicted maximum value.

[0193] Next, the information analysis unit 222 determines the addition target B of the predicted maximum value (step S353). The addition target B in FIG. 22 is the base station 17 other than the addition target A that belongs to the second group, for example, the base station 17 with the smallest predicted maximum value. The information analysis unit 222 adds up the predicted maximum value of the addition target A and the predicted maximum value of the addition target B to determine the total value T ｔｏｔａｌ is calculated (step S354).

[0194] The information analysis unit 222 calculates the total value T ｔｏｔａｌ The information analysis unit 222 compares the calculated total value T ｔｏｔａｌ is compared with the threshold value of the base station 17 corresponding to the addition target A.

[0195] The information analysis unit 222 calculates the total value T ｔｏｔａｌ The information analysis unit 222 determines whether the total value T ｔｏｔａｌ is not greater than the threshold value (step S355—NO), the information analysis unit 222 adds the predicted maximum values ​​of the base stations 17 classified into the second group that have not been added, to obtain a new total value T ｔｏｔａｌ For example, the information analysis unit 222 calculates a new total value T by adding the smallest predicted maximum value among the predicted maximum values ​​of the base stations 17 classified into the second group that have not yet been added. ｔｏｔａｌ In addition, if the maximum predicted value of a base station 17 that has not been added among the base stations 17 classified in the second group is a maximum predicted value, the information analysis unit 222 may add the value of the maximum predicted value other than the smallest maximum predicted value to obtain a new total value T ｔｏｔａｌ may be calculated.

[0196] Thereafter, the information analysis unit 222 executes the process of step S355 again. In this case, the information analysis unit 222 calculates the newly calculated total value T ｔｏｔａｌ The information analysis unit 222 determines whether the total value T ｔｏｔａｌis greater than the threshold (step S355—YES), the information analysis unit 222 determines the base station 17 to be aggregated (step S357). Specifically, the information analysis unit 222 determines the base station 17 to be aggregated from among the base stations 17 corresponding to the respective predicted maximum values ​​added up before the threshold was exceeded. For example, the information analysis unit 222 may determine the base station 17 with the largest predicted maximum value among the base stations 17 corresponding to the respective predicted maximum values ​​added up before the threshold was exceeded as the base station 17 to be aggregated. Note that the information analysis unit 222 may determine the base station 17 with the largest traffic volume among the base stations 17 corresponding to the respective predicted maximum values ​​added up before the threshold was exceeded as the base station 17 to be aggregated.

[0197] As an example, if the base stations 17 corresponding to the maximum predicted values ​​added up before exceeding the threshold are base stations 17-1 to 17-3, the information analysis unit 222 determines the base station 17 to be aggregated from among the base stations 17-1 to 17-3. Here, it is assumed that base station 17-1 is determined to be the aggregation destination.

[0198] Thereafter, the information analysis unit 222 notifies the control unit 23 of control information including an optical path control instruction and a sleep instruction. The information analysis unit 222 includes, for example, information indicating that the base stations from which the switching is to be performed are base stations 17-2 and 17-3 and information indicating that the base station to which the switching is to be performed is base station 17-1 in the optical path control instruction. The information analysis unit 222 includes, for example, information indicating that the base stations to be put to sleep are base stations 17-2 and 17-3.

[0199] The optical path control unit 231 determines the base station 17 that will be the source of optical path switching and the base station 17 that will be the destination of optical path switching, based on the optical path control instructions included in the control information notified by the information analysis unit 222. Here, the optical path control unit 231 determines base station 17-1 as the destination of optical path switching, and determines base stations 17-2 and 17-3 as the source of optical path switching. The optical path control unit 231 transmits optical path control information including information indicating the destination base station and source base station of the determined optical path to the transfer device 14 (step S358).

[0200] As a result, the transfer device 14 switches the optical path route by switching the optical paths heading toward the base stations 17-2 and 17-3 to head toward the base station 17-1. Furthermore, the optical path control unit 231 transmits an optical path control instruction to the switching source base station of the determined optical path (step S359).

[0201] The sleep control unit 232 determines the base station 17 to be put into sleep mode based on the sleep instruction included in the control information notified by the information analysis unit 222. Here, the sleep control unit 232 determines the base station 17-2 and the base station 17-3 as the base stations to be put into sleep mode. The sleep control unit 232 transmits a sleep instruction to the determined base stations 17-2 and 17-3 (step S360). This allows the base station 17-2 and the base station 17-3 to be put into sleep mode.

[0202] 22 shows a configuration in which sleep control is performed after optical path switching control is performed, but the management control device 20 may perform optical path switching control after sleep control is performed. Furthermore, the processing of step S359 may be executed by the optical path switching function of the transfer device 14.

[0203] Fig. 23 is a flowchart showing an example of the flow of sleep release processing (part 2) executed by the management control device 20 in the second embodiment. Fig. 23 explains a case where sleep release processing is performed on a base station 17 with irregular traffic transitions (a base station 17 belonging to the second group). Note that the explanation here takes traffic information as an example of cooperation information. In Fig. 23, the explanation is given assuming M = N = 4. Here, it is assumed that base stations 17-2 to 17-4 are in sleep mode.

[0204] The acquisition unit 211 acquires cooperation information from each of the base stations 17-1 to 17-4 (step S451). The acquisition unit 211 stores the acquired cooperation information for each base station 17 in the storage unit 221.

[0205] The information analysis unit 222 reads the cooperation information for each base station 17 stored in the storage unit 221 (step S452). The information analysis unit 222 predicts the traffic volume for each base station 17-1 to 17-4 based on the read cooperation information for each base station 17 (step S453). The information analysis unit 222 determines whether there is a base station 17 whose predicted traffic volume exceeds a threshold (step S454). The threshold used here may be the same as or different from the threshold used in FIG. 22. For example, the information analysis unit 222 compares the traffic volume predicted for base station 17-1 with the threshold for base station 17-1 to determine whether the predicted traffic volume exceeds the threshold.

[0206] If the information analysis unit 222 determines that there is no base station 17 whose predicted traffic volume exceeds the threshold (step S454—NO), the management control device 20 terminates the processing of FIG. 23. On the other hand, if the information analysis unit 222 determines that there is a base station 17 whose predicted traffic volume exceeds the threshold (step S454—YES), the information analysis unit 222 determines the base station 17 to be released from sleep mode (step S455). Here, it is assumed that the base station 17 whose predicted traffic volume exceeds the threshold is base station 17-1. The information analysis unit 222 identifies the other base station 17 with the highest traffic volume among the traffic volumes aggregated at base station 17-1 from among the sleeping base stations 17-2 to 17-4. As the identification method, either (Identification Method 1) or (Identification Method 2) described in the first embodiment is used.

[0207] It is assumed that base station 17-2 is identified as the other base station 17 with the highest traffic volume by any of the above identification methods. The information analysis unit 222 determines the identified base station 17-2 as the base station 17 to be released from sleep mode. Thereafter, the information analysis unit 222 notifies the control unit 23 of control information including an optical path control instruction and a sleep release instruction. For example, the information analysis unit 222 includes, in the optical path control instruction, information indicating that the base station to be switched to is base station 17-2. For example, the information analysis unit 222 includes information indicating that the base station to be released from sleep mode is base station 17-2.

[0208] The optical path control unit 231 determines the base station 17 to be the control target of the optical path based on the optical path control instruction included in the control information notified from the information analysis unit 222. Here, the optical path control unit 231 determines the base station 17-2 as the control target of the optical path. The optical path control unit 231 transmits optical path control information including information indicating the base station to be controlled for the determined optical path to the transfer device 14 (step S456). As a result, the transfer device 14 forms an optical path directed to the base station 17-2.

[0209] The sleep control unit 232 determines the base station 17 to be released from sleep mode based on the sleep release instruction included in the control information notified by the information analysis unit 222. Here, the sleep control unit 232 determines the base station 17-2 as the base station to be released from sleep mode. The sleep control unit 232 transmits the sleep release instruction to the determined base station 17-2 (step S457). This allows the base station 17-2 to be released from sleep mode.

[0210] The mobile network system 100 according to the second embodiment configured as described above includes a collection unit 21 that acquires cooperation information from a plurality of base stations 17, and an analysis unit 22 that classifies the plurality of base stations 17 into a plurality of groups based on the cooperation information, determines one or more base stations 17 to be subjected to sleep control from among the plurality of base stations 17 belonging to any of the classified groups, and executes sleep control on the one or more base stations 17 to be subjected to sleep control. This allows the sleep control to be determined taking into account the cooperation information obtained from each base station 17. This makes it possible to increase the effect of power saving without degrading communication quality.

[0211] In the mobile NW system 100 according to the second embodiment, when there is a sudden increase in traffic volume, the sleeping base station 17 is started up, thereby making it possible to save power without degrading the quality of communication.

[0212] In the mobile network system 100 according to the second embodiment, when waking up the base stations 17 belonging to the first group, traffic prediction is performed only when the current traffic volume exceeds the total value of the maximum predicted traffic volume. In this way, the base stations 17 belonging to the first group do not need to constantly predict traffic. This allows for reduced power consumption.

[0213] (Variation 1 of Second Embodiment) In the above-described embodiment, a configuration has been shown in which the management control device 20 performs optical path control processing and sleep control processing. In contrast, a forwarding device may be configured to perform optical path control processing and sleep control processing. In such a configuration, the mobile NW system 200 includes a forwarding device 14a shown in FIG. 11 instead of the forwarding device 14, and a management control device 20a shown in FIG. 11 instead of the management control device 20. The specific processing can be achieved by replacing the radio station 12 and the central station 16 with the base station 17 in the processing described in FIG. 11.

[0214] (Variation 2 of Second Embodiment) In the above-described embodiment, a configuration has been shown in which the management control device 20 performs optical path control processing and sleep control processing. Alternatively, a configuration may be adopted in which the management control device performs sleep control processing and the forwarding device performs optical path control processing. In such a configuration, the mobile NW system 200 includes a forwarding device 14b shown in FIG. 12 instead of the forwarding device 14, and a management control device 20b shown in FIG. 12 instead of the management control device 20. The specific processing can be achieved by replacing the radio station 12 and the central station 16 with the base station 17 in the processing described in FIG. 12.

[0215] (Variation 3 of the Second Embodiment) In the above-described embodiment, a configuration has been shown in which the management control device 20 performs optical path control processing and sleep control processing. However, the optical path control processing and sleep control processing may be performed by different devices. In such a configuration, the mobile NW system 200 includes an optical transmission management control device 65 and a radio transmission management control device 70 shown in FIG. 13 instead of the management control device 20. The specific processing can be achieved by replacing the radio station 12 and the central station 16 with the base station 17 in the processing described in FIG. 13.

[0216] (Variation 4 of the Second Embodiment) In the above-described embodiment, a configuration has been shown in which the management control device 20 performs optical path control processing and sleep control processing. However, the optical path control processing and sleep control processing may be performed by different devices. In such a configuration, the mobile NW system 200 includes an optical transmission management control device 65 and a radio transmission management control device 70 shown in FIG. 14 instead of the management control device 20. The specific processing can be achieved by replacing the radio station 12 and the central station 16 with the base station 17 in the processing described in FIG. 14.

[0217] (Fifth Modification of the Second Embodiment) The mobile NW system 200 may be configured as shown in Fig. 15. In this configuration, the mobile NW system 200 includes an optical transmission management control device 65, a radio transmission management control device 70, and an orchestrator 75 shown in Fig. 15 instead of the management control device 20. The specific processing can be performed by replacing the radio station 12 and the central station 16 with the base station 17 in the processing described in Fig. 15.

[0218] (Variation 6 of the Second Embodiment) The mobile NW system 200 may be configured as shown in Fig. 16. In this configuration, the mobile NW system 200 includes an optical transmission management control device 65, a radio transmission management control device 70, and an orchestrator 75 shown in Fig. 16 instead of the management control device 20. Specific processing can be performed by replacing the radio station 12 and the central station 16 with the base station 17 in the processing described in Fig. 16.

[0219] (Seventh Modification of the Second Embodiment) The mobile NW system 200 may be configured as shown in Fig. 17. In this configuration, the mobile NW system 200 includes an optical transmission management control device 65 and a radio transmission management control device shown in Fig. 17 instead of the management control device 20. The specific processing can be performed by replacing the radio station 12 and the central station 16 with the base station 17 in the processing described in Fig. 17.

[0220] (Variation 8 of the Second Embodiment) The cooperation information may include, for example, information on the number of terminals accommodated in each base station 17. The cooperation information may include, for example, processing load information of the base station 17. The processing load information in the second embodiment may be, for example, information on memory usage rate or CPU usage rate of the base station 17. The cooperation information may include communication quality information of the terminals 11 connected to each base station 17.

[0221] When the cooperation information includes information regarding the number of accommodated terminals, the information analysis unit 222 may select a base station to be subjected to sleep control (for example, a base station to be subjected to sleep control or a base station to be subjected to sleep cancellation) using the information regarding the number of accommodated terminals. When configured in this manner, the information analysis unit 222 may select a base station to be subjected to sleep control in the same way as when traffic information is used.

[0222] First, the information analysis unit 222 predicts the number of accommodated terminals for a certain period of time for each base station 17 using information about the past number of accommodated terminals collected from each base station 17. The information analysis unit 222 classifies each base station 17 into a plurality of groups based on the prediction result of the number of accommodated terminals. For example, the information analysis unit 222 classifies each base station 17 into either a first group or a second group. In this case, the first group is a group for which it is determined that the change in the number of accommodated terminals is constant or regular, based on the prediction result of the number of accommodated terminals. The second group is a group for which it is determined that the change in the number of accommodated terminals is constant or irregular, based on the prediction result of the number of accommodated terminals.

[0223] Thereafter, the information analysis unit 222 aggregates traffic among the multiple base stations 17 belonging to the first group. For example, the information analysis unit 222 selects the maximum number of accommodated terminals among the predicted numbers of accommodated terminals from each of the multiple base stations 17 belonging to the first group. As an example, if the multiple base stations 17 belonging to the first group are base stations 17-1 to 17-3, the information analysis unit 222 selects the maximum predicted number of terminals for base station 17-1, the maximum predicted number of terminals for base station 17-2, and the maximum predicted number of terminals for base station 17-3, respectively.

[0224] The information analysis unit 222 then sums up the maximum predicted number of terminals for each of the selected base stations 17-1, 17-2, and 17-3 in order. At this time, the information analysis unit 222 may sum up the maximum predicted number of terminals in ascending order, or may sum up the maximum predicted number of terminals in descending order. By summing up in ascending order, it is possible to consolidate many base stations 17, and in this case, it is possible to transition many base stations 17 to a sleep state. As a result, it is possible to improve the power saving effect. The information analysis unit 222 sums up the maximum predicted number of terminals up to the point where the sum does not exceed the threshold.

[0225] If the total value exceeds the threshold, the information analysis unit 222 selects a sleep target based on the maximum predicted number of terminals added up to the time before the threshold is exceeded. For example, the information analysis unit 222 selects a sleep candidate based on the base station 17 with the maximum predicted number of terminals added up to the time before the threshold is exceeded. Similarly, if there are no more maximum predicted numbers of terminals to add up, the information analysis unit 222 selects a sleep target based on the maximum predicted number of terminals added up to the time before the threshold is exceeded. Before selecting a sleep target, the information analysis unit 222 determines a base station 17 to be an aggregation destination from among the sleep candidate targets. For example, the information analysis unit 222 may determine the base station 17 with the largest number of accommodated terminals among the sleep candidate targets as the aggregation destination base station 17, or the base station 17 with the largest maximum predicted number of terminals as the aggregation destination base station 17, or may determine a base station 17 based on a predetermined priority order. Then, the information analysis unit 222 determines a base station 17 other than the aggregation destination from among the sleep candidate targets as the sleep target.

[0226] When the cooperation information includes processing load information and communication quality information, the information analysis unit 222 may select a sleep control target (e.g., a sleep target or a sleep release target) using the processing load information or communication quality information in addition to the traffic information. For example, when selecting a sleep control target using communication quality information in addition to traffic information, the information analysis unit 222 determines to perform sleep control when a condition based on the traffic information and a condition based on the communication quality information are satisfied. The condition based on the communication quality information may be, for example, a condition based on whether a path after sleep is feasible (e.g., whether quality degradation occurs). In this case, even if the information analysis unit 222 determines the base station 17 to be the sleep target and the base station 17 to be the optical path control target based on the condition based on the traffic information, quality degradation may occur after the path is switched. Therefore, even if the information analysis unit 222 determines the base station 17 to be the sleep target and the base station 17 to be the optical path control target based on the condition based on the traffic information, the information analysis unit 222 may not execute sleep if quality degradation occurs on the path after optical path control.

[0227] (Third Embodiment) In the above-described first and second embodiments, configurations for solving problems that arise in mobile network systems have been described. Specifically, in the first and second embodiments, configurations for solving a problem that arises in a mobile network system in which wireless communication is performed between a terminal and each base station, each base station autonomously determines whether or not to sleep, which may prevent overall optimization and limit the effect of power saving. However, such problems are not limited to mobile network systems, but may also arise in wired network systems in which terminals are connected by wire. Therefore, in the third embodiment, a configuration for solving the above problems that may arise in wired network systems will be described.

[0228] (Overall configuration and processing overview of wired network system) FIG. 24 is a diagram for explaining an overview of the overall configuration and processing of a wired network system in an embodiment. First, the overall configuration of the wired network system will be explained. The wired network system is an example of a communication system. The wired network system is, for example, a PON (Passive Optical Network). In the following explanation, a case where the wired network system is a PON will be explained, but the wired network system may have other configurations as long as terminals are connected by wire. For example, the wired network system may have a configuration in which terminals are connected point-to-point. The wired network system includes multiple ONUs 42, a transfer device 43, multiple OLTs 44, a concentrator 45, a core device 46, and a management control device 50.

[0229] Optical fibers that transmit optical signals are connected between each ONU 42 and the transfer device 43, between the transfer device 43 and each OLT 44, between each OLT 44 and the concentrator 45, and between the concentrator 45 and the core device 46. Electrical lines or optical fibers that transmit electrical signals are connected between the transfer device 43 and the management control device 50, and between each OLT 44 and the management control device 50. The example shown in Figure 24 shows a case where there are four ONUs 42 and two OLTs 44. Note that multiple transfer devices 43 may be provided, but the following explanation will be given using a case where there is one.

[0230] The ONUs 42 are optical subscriber line terminals provided in user premises that terminate optical signals. One or more terminals 41 are connected to each ONU 42 via wires such as electrical lines. Each ONU 42 performs wired communication with the terminals 41. For example, each ONU 42 receives an electrical signal transmitted from the terminal 41 and converts the received electrical signal into an optical signal. Each ONU 42 transmits the converted optical signal to the OLT 44 connected thereto via a transfer device 43. Each ONU 42 receives the optical signal via the transfer device 43. Each ONU 42 converts the received optical signal into an electrical signal and transmits it to the terminal 41. The ONUs 42 are one aspect of other devices.

[0231] The transfer device 43 is provided between the ONU 42 and the OLT 44. The transfer device 43 is a switch that connects the ONU 42 and the OLT 44 via an optical path. The transfer device 43 switches the optical path in accordance with optical path control information transmitted from the management control device 50. The transfer device 43 switches the connection between the ONU 42 and the OLT 44 by switching the optical path.

[0232] The OLT 44 is an optical line termination device provided on the electric utility side and terminates optical signals. The OLT 44 receives upstream signals transmitted from one or more ONUs 42 via a transfer device 43. The OLT 44 transmits downstream signals to one or more ONUs 42 connected via the transfer device 43. The upstream signals transmitted from one or more ONUs 42 are signals obtained by converting signals transmitted from the terminal 41 into optical signals, and the downstream signals are optical signals addressed to the terminal 41. Each OLT 44 transitions to a sleep state in accordance with a sleep instruction transmitted from the management control device 50. Information acquired by the management control device 50 from the OLT 44 is called coordination information. The coordination information in the third embodiment is information indicating the state of communication between each OLT 44 and the terminal 41. The OLT 44 is one aspect of a communication station.

[0233] The cooperation information in the third embodiment includes, for example, information on the traffic volume of each central office 16. The traffic information is the same as in the first embodiment.

[0234] The OLT 44 includes at least a transmitter, a receiver, and a sleep processor. The transmitter transmits coordination information to the management controller 50 either in response to a request from the management controller 50 or independently. The receiver receives an optical path control instruction from the management controller 50. The OLT 44 receiving an optical path control instruction from the management controller 50 indicates that the management controller 50 has determined, based on the coordination information, that it is necessary to switch the optical path between the ONU 42 and the OLT 44. The sleep processor transitions to a sleep state after switching the optical path based on the optical path control instruction. Furthermore, the OLT 44 includes an optical path switching processor for performing optical path switching processing.

[0235] The concentrator 45 aggregates the upstream signals transmitted by the OLTs 44. The concentrator 45 distributes the downstream signals.

[0236] The core device 46 performs signal processing on the upstream signals aggregated by the concentrator 45. The concentrator 45 transmits the signals obtained as a result of the signal processing performed on the upstream signals to an external network. The core device 46 receives signals from the external network.

[0237] The core device 46 performs predetermined signal processing on signals received from an external network, and transmits the signals obtained as a result of the signal processing performed on the signals received from the external network to the concentrator 45 as downstream signals.

[0238] The management control device 50 is a device that manages the entire wired network system. The management control device 50 acquires coordination information from each OLT 44. When acquiring coordination information from each OLT 44, the management control device 50 uses a coordination interface. The management control device 50 determines whether optical path control and sleep control are necessary based on the acquired coordination information. When it is determined that optical path control and sleep control are necessary, the management control device 50 performs optical path control processing and sleep control processing. The optical path control processing in the third embodiment is processing that switches optical paths between the ONU 42 and the OLT 44 and generates optical paths. The sleep control processing in the third embodiment is processing that puts the OLT 44 into sleep mode or releases sleep.

[0239] Next, an overview of the processing of the wired network system will be explained. The upper diagram of Fig. 24 shows the connection state of the wired network system before optical path switching, and the lower diagram of Fig. 24 shows the connection state of the wired network system after optical path switching. The upper diagram of Fig. 24 shows an example in which ONUs 42-1 and 42-2 are connected to OLT 44-1, and ONUs 42-3 and 42-4 are connected to OLT 44-2.

[0240] The management control device 50 performs optical path control processing and sleep control processing when one OLT 44 can accommodate traffic of another OLT 44 based on the coordination information collected from each OLT 44. For example, the management control device 50 performs optical path control processing and sleep control processing in OLT 44-2 when traffic of OLT 44-1 can be accommodated. In this way, by accommodating traffic of another OLT 44 in one OLT 44, the other OLT 44 can be transitioned to a sleep state.

[0241] When the management control device 50 determines that the optical path control process should be performed, it transmits information about the optical path switching destination to the transfer device 43 and instructs the OLT 44, which is the optical path switching target, to switch the optical path.

[0242] The lower diagram of Figure 24 shows an example in which ONUs 42-1 to 42-4 are connected to OLT 44-1 and OLT 44-2 has transitioned to a sleep state. In this way, in a wired network system, based on the linkage information collected from each OLT 44, a terminal 41 connected to an OLT 44 that can transition to a sleep state is connected to another OLT 44, thereby transitioning the OLT 44 that can transition to a sleep state to a sleep state. Hereinafter, an OLT 44 that can transition to a sleep state will be referred to as a switching source OLT, and an OLT 44 that will be the new connection destination of a terminal 41 connected to the switching source OLT will be referred to as a switching destination OLT. A specific configuration will be described below.

[0243] Fig. 25 is a diagram showing an example of the configuration of a wired NW system 300 according to the third embodiment. The wired NW system 300 according to the fifth embodiment includes a plurality of ONUs 42-1 to 42-M, a transfer device 43, a plurality of OLTs 44-1 to 44-N, a concentrator 45, a core device 46, and a management control device 50. The ONUs 42, the transfer device 43, the OLT 44, the concentrator 45, and the core device 46 have been described in Fig. 24, and therefore description thereof will be omitted.

[0244] The management control device 50 includes a collection unit 51, an analysis unit 52, and a control unit 53. The collection unit 51 includes an acquisition unit 511. The acquisition unit 511 collects cooperation information from each OLT 44 at a predetermined period or at any timing. For example, the acquisition unit 511 collects traffic information of each OLT 44 as cooperation information.

[0245] The analysis unit 52 includes a storage unit 521 and an information analysis unit 522. The storage unit 521 records the collected linkage information in a predetermined storage device. Furthermore, the storage unit 521 stores the total value of the predicted maximum values ​​calculated by the information analysis unit 522.

[0246] The information analysis unit 522 analyzes the state of communication between each OLT 44 and the terminal 41 based on the coordination information. Specifically, the information analysis unit 522 determines whether optical path control and sleep control are necessary based on the coordination information. The information analysis unit 522 predicts the traffic volume of each OLT 44 based on the coordination information stored in the storage unit 521, for example. The information analysis unit 522 classifies each OLT 44 into either a first group or a second group based on the traffic volume prediction result. Then, the information analysis unit 522 determines whether optical path control and sleep control are necessary for each classified group.

[0247] The information analysis unit 522 determines that optical path control and sleep control are necessary, for example, when all of the terminals 41 accommodated in one OLT 44 belonging to the first group can be accommodated in any of the OLTs 44 belonging to the first group. Similarly, the information analysis unit 522 determines that optical path control and sleep control are necessary, for example, when all of the terminals 41 accommodated in one OLT 44 belonging to the second group can be accommodated in any of the OLTs 44 belonging to the second group.

[0248] When the information analysis unit 522 determines that optical path control and sleep control are necessary, it notifies the control unit 53 of control information including an optical path control instruction and a sleep instruction. The optical path control instruction in the third embodiment is an instruction to request switching of the optical path, and includes, for example, information indicating the OLT 44 that is the source of the optical path switching and information indicating the OLT 44 that is the destination of the optical path switching. The sleep instruction in the third embodiment is an instruction to execute sleep, and includes, for example, information indicating the OLT 44 that is the sleep target. The method of selecting the sleep target in the information analysis unit 522 is the same as in the first embodiment.

[0249] Furthermore, when the traffic volume of a certain OLT 44 exceeds a threshold, the information analysis unit 522 determines that optical path control and sleep control are necessary. In this case, the information analysis unit 522 notifies the control unit 53 of control information including an optical path control instruction and a sleep release instruction. The sleep release instruction in the third embodiment is an instruction to execute sleep release, and includes, for example, information indicating the OLT 44 to be released from sleep. The method of selecting the OLT 44 to be released from sleep in the information analysis unit 522 is the same as in the first embodiment.

[0250] The control unit 53 includes an optical path control unit 531 and a sleep control unit 532. The optical path control unit 531 determines the OLT 44 that will be the source of optical path switching and the OLT 44 that will be the destination of optical path switching based on the analysis results of the information analysis unit 522. For example, the optical path control unit 531 determines the OLT 44 that will be the source of optical path switching based on information that indicates the OLT 44 that will be the source of optical path switching, which is included in the control information notified from the information analysis unit 522. For example, the optical path control unit 531 determines the OLT 44 that will be the destination of optical path switching based on information that indicates the OLT 44 that will be the destination of optical path switching, which is included in the control information notified from the information analysis unit 522.

[0251] The optical path control unit 531 transmits optical path control information including information indicating the OLT 44 to which the determined optical path is to be switched to the transfer device 43. As a result, the optical path control unit 531 instructs the transfer device 43 to switch the optical path. Furthermore, the optical path control unit 531 transmits an optical path control instruction to the OLT 44 to which the determined optical path is to be switched.

[0252] The sleep control unit 532 causes the OLT 44 that is the target of sleep control to execute sleep or cancel sleep based on the analysis result of the information analysis unit 522 .

[0253] Fig. 26 is a flowchart showing an example of the flow of sleep processing (part 1) executed by the management control device 50 in the third embodiment. Fig. 26 explains a case where sleep processing is performed on an OLT 44 (OLT 44 belonging to the first group) where traffic transitions are constant or regular. The processing in Fig. 26 is repeatedly executed at a predetermined cycle. Note that, here, traffic information will be used as an example of the linkage information. In Fig. 26, the explanation will be given assuming M = N = 4.

[0254] The acquisition unit 511 acquires cooperation information from each of the OLTs 44-1 to 44-4 (step S501). For example, the acquisition unit 511 may collect information once per unit time as a predetermined cycle, or may collect information at any timing. The acquisition unit 511 stores the acquired cooperation information for each OLT 44 in the storage unit 521 (step S502).

[0255] The information analysis unit 522 predicts the traffic transition for each of the OLTs 44-1 to 44-4 for a certain period of time (step S503) based on the cooperation information for each OLT 44 stored in the storage unit 521. Thereafter, the information analysis unit 522 classifies the OLTs 44-1 to 44-4 into either a first group or a second group based on the predicted traffic transition results (step S504).

[0256] The information analysis unit 522 determines whether there are multiple OLTs 44 classified into the first group (step S505). If the information analysis unit 522 determines that there are not multiple OLTs 44 classified into the first group (step S505-NO), traffic cannot be aggregated within the first group. Therefore, the management control device 50 ends the processing of FIG. 26.

[0257] On the other hand, if the information analysis unit 522 determines that there are multiple OLTs 44 classified into the first group (step S505—YES), the information analysis unit 522 determines an addition target A for the maximum predicted value (step S506). The addition target A in FIG. 26 is, for example, the reference OLT 44 among the OLTs 44 classified into the first group. The addition target A may be determined randomly, or may be the OLT 44 with the smallest maximum predicted value, or the central office 16 with the largest maximum predicted value.

[0258] Next, the information analysis unit 522 determines the summation target B of the predicted maximum value (step S507). The summation target B in FIG. 26 is the OLT 44 other than the summation target A that belongs to the first group, for example, the OLT 44 with the smallest predicted maximum value. The information analysis unit 522 sums the predicted maximum value of the summation target A and the predicted maximum value of the summation target B to determine the total value T ｔｏｔａｌ is calculated (step S508).

[0259] The information analysis unit 522 calculates the total value T ｔｏｔａｌ and a threshold value. The threshold value in the third embodiment is a value for control judgment, and indicates the maximum traffic volume that the OLT 44 can handle. The threshold value may be the same value for each OLT 44, or may be a different value for each OLT 44. The threshold value may be calculated based on the cooperation information, or may be stored in advance by the information analysis unit 522 for each OLT 44. The information analysis unit 522 compares the calculated total value T ｔｏｔａｌ is compared with the threshold value of the OLT 44 corresponding to the addition target A.

[0260] The information analysis unit 522 calculates the total value T ｔｏｔａｌ The information analysis unit 522 determines whether the total value Tｔｏｔａｌ is not greater than the threshold value (step S509-NO), the information analysis unit 522 calculates a new total value T by adding the predicted maximum values ​​of the OLTs 44 that have not been added among the OLTs 44 classified into the first group. ｔｏｔａｌ For example, the information analysis unit 522 calculates a new total value T by adding the smallest predicted maximum value among the predicted maximum values ​​of the OLTs 44 classified into the first group that have not been added. ｔｏｔａｌ In addition, if there is a maximum predicted value of an OLT 44 that has not been added among the OLTs 44 classified in the first group, the information analysis unit 522 may add the value of the maximum predicted value other than the smallest maximum predicted value to obtain a new total value T ｔｏｔａｌ may be calculated.

[0261] After that, the information analysis unit 522 executes the process of step S509 again. In this case, the information analysis unit 522 calculates the newly calculated total value T ｔｏｔａｌ The information analysis unit 522 determines whether the total value T ｔｏｔａｌ is greater than the threshold value (step S509-YES), the information analysis unit 522 records the total value of the predicted maximum values ​​added up until the threshold value is exceeded in the storage unit 521 (step S511).

[0262] Furthermore, the information analysis unit 522 determines the OLT 44 to be the aggregation destination (step S512). Specifically, the information analysis unit 522 determines the aggregation destination OLT 44 from among the OLTs 44 corresponding to each predicted maximum value added up until the threshold value is exceeded. For example, the information analysis unit 522 may determine the OLT 44 with the largest predicted maximum value among the OLTs 44 corresponding to each predicted maximum value added up until the threshold value is exceeded as the aggregation destination OLT 44. Note that the information analysis unit 522 may determine the OLT 44 with the largest traffic volume among the OLTs 44 corresponding to each predicted maximum value added up until the threshold value is exceeded as the aggregation destination OLT 44.

[0263] As an example, if the OLTs 44 corresponding to the respective predicted maximum values ​​added up before exceeding the threshold are the OLTs 44-1 to 44-3, the information analysis unit 522 determines the OLT 44 to be aggregated from among the OLTs 44-1 to 44-3. Here, it is assumed that the OLT 44-1 is determined as the aggregation destination.

[0264] Thereafter, the information analysis unit 522 notifies the control unit 53 of control information including an optical path control instruction and a sleep instruction. The information analysis unit 522 includes, for example, information indicating that the switching source OLTs are OLTs 44-2 and 44-3 and information indicating that the switching destination OLT is OLT 44-1 in the optical path control instruction. The information analysis unit 522 includes, for example, information indicating that the sleep target OLTs are OLTs 44-2 and 44-3.

[0265] The optical path control unit 531 determines the OLT 44 that will be the source of optical path switching and the OLT 44 that will be the destination of optical path switching, based on the optical path control instructions included in the control information notified from the information analysis unit 522. Here, the optical path control unit 531 determines OLT 44-1 as the destination of optical path switching, and determines OLTs 44-2 and 44-3 as the source of optical path switching. The optical path control unit 531 transmits optical path control information including information indicating the destination OLT and source OLT of the determined optical path to the transfer device 43 (step S513).

[0266] As a result, the transfer device 43 switches the optical path route by switching the optical paths heading toward the OLTs 44-2 and 44-3 to those heading toward the OLT 44-1. Furthermore, the optical path control unit 531 transmits an optical path control instruction to the OLT from which the determined optical path is to be switched (step S514).

[0267] The sleep control unit 532 determines the OLT 44 to be put into sleep mode based on the sleep instruction included in the control information notified from the information analysis unit 522. Here, the sleep control unit 532 determines OLT 44-2 and OLT 44-3 as the sleep targets. The sleep control unit 532 transmits a sleep instruction to each of the determined devices (step S515). This allows the sleep target devices to transition to a sleep state.

[0268] 26 shows a configuration in which sleep control is performed after optical path switching control is performed, but the management control device 50 may perform optical path switching control after sleep control is performed. Furthermore, the processing of step S514 may be executed by the optical path switching function of the transfer device 43.

[0269] Fig. 27 is a flowchart showing an example of the flow of sleep release processing (part 1) executed by the management control device 50 in the third embodiment. Fig. 27 explains a case where sleep release processing is performed on an OLT 44 (OLT 44 belonging to the first group) where traffic transitions are constant or regular. Note that the explanation here takes traffic information as an example of the linkage information. In Fig. 27, the explanation is given assuming M = N = 4. Here, it is assumed that OLTs 44-2 to 44-4 are in sleep mode.

[0270] The acquiring unit 511 acquires the cooperation information from each of the OLTs 44-1 to 44-4 (step S601). The acquiring unit 511 stores the acquired cooperation information for each OLT 44 in the storage unit 521.

[0271] The information analysis unit 522 reads the cooperation information and the total value of the predicted traffic of each OLT 44 stored in the storage unit 521 (step S602). The information analysis unit 522 calculates the traffic volume of each OLT 44-1 to 44-4 based on the cooperation information for each OLT 44 that has been read (step S603). The information analysis unit 522 determines whether the traffic volume of the OLT 44 that has become the aggregation destination in the processing of FIG. 26 exceeds the total value of the predicted maximum values ​​(step S604). If the information analysis unit 522 determines that the traffic volume of the OLT 44 that has become the aggregation destination in the processing of FIG. 26 does not exceed the total value of the predicted maximum values ​​(step S604-NO), the management control device 50 ends the processing of FIG. 27.

[0272] On the other hand, if the information analysis unit 522 determines that the traffic volume of the OLT 44 that was selected as the aggregation destination in the processing of FIG. 26 exceeds the total value of the predicted maximum values ​​(step S604—YES), the information analysis unit 522 re-predicts the traffic volume of each of the OLTs 44-1 to 44-4 based on the read collaboration information for each OLT 44 (step S605). The information analysis unit 522 then determines whether there is an OLT 44 whose predicted traffic volume exceeds a threshold (step S606). The threshold used here may be the same as or different from the threshold used in FIG. 26. For example, the information analysis unit 522 compares the traffic volume predicted for the OLT 44-1 with the threshold for the OLT 44-1 to determine whether the predicted traffic volume exceeds the threshold.

[0273] If the information analysis unit 522 determines that there is no OLT 44 whose traffic volume exceeds the threshold (step S606—NO), the management control device 50 terminates the processing of FIG. 27. On the other hand, if the information analysis unit 522 determines that there is an OLT 44 whose traffic volume exceeds the threshold (step S606—YES), the information analysis unit 522 determines the OLT 44 to be released from sleep mode (step S607). Here, it is assumed that the OLT 44 whose traffic volume exceeds the threshold is OLT 44-1. The information analysis unit 522 identifies the other OLT 44 with the largest traffic volume among the traffic volumes aggregated to OLT 44-1 from among the sleeping OLTs 44-2 to 44-4. As a method of identification, either (Identification Method 1) or (Identification Method 2) described in the first embodiment is used.

[0274] It is assumed that the OLT 44-2 is identified as the other OLT 44 with the highest traffic volume by any of the above identification methods. The information analysis unit 522 determines the identified OLT 44-2 as the OLT 44 to be released from sleep mode. Thereafter, the information analysis unit 522 notifies the control unit 53 of control information including an optical path control instruction and a sleep release instruction. For example, the information analysis unit 522 includes information indicating that the OLT to be switched to is the OLT 44-2 in the optical path control instruction. For example, the information analysis unit 522 includes information indicating that the OLT to be released from sleep mode is the OLT 44-2.

[0275] The optical path control unit 531 determines the OLT 44 that will be the control target of the optical path based on the optical path control instruction included in the control information notified from the information analysis unit 522. Here, the optical path control unit 531 determines the OLT 44-2 as the control target of the optical path. The optical path control unit 531 transmits optical path control information including information indicating the OLT that will be the control target of the determined optical path to the transfer device 43 (step S608). As a result, the transfer device 43 forms an optical path toward the OLT 44-2.

[0276] The sleep control unit 532 determines the OLT 44 to be released from sleep mode based on the sleep release instruction included in the control information notified from the information analysis unit 522. Here, the sleep control unit 532 determines the OLT 44-2 as the release target. The sleep control unit 532 transmits a sleep release instruction to the determined OLT 44-2 (step S609). This allows the OLT 44-2 to be released from sleep mode.

[0277] Fig. 28 is a flowchart showing an example of the flow of sleep processing (part 2) executed by the management control device 20 in the third embodiment. Fig. 28 explains a case where sleep processing is performed on an OLT 44 with irregular traffic transitions (OLT 44 belonging to the second group). The processing in Fig. 28 is repeatedly executed at a predetermined cycle. Note that, here, traffic information will be used as an example of the linkage information. In Fig. 28, the explanation will be given assuming M = N = 4. In Fig. 28, the same processes as those in Fig. 26 are assigned the same reference numerals as those in Fig. 26, and explanations thereof will be omitted.

[0278] After the processing from step S501 to step S504 is completed, the information analysis unit 522 determines whether there are multiple OLTs 44 classified into the second group (step S551). If the information analysis unit 522 determines that there are not multiple OLTs 44 classified into the second group (step S551-NO), traffic cannot be aggregated within the second group. Therefore, the management control device 50 ends the processing of FIG. 28.

[0279] On the other hand, if the information analysis unit 522 determines that there are multiple OLTs 44 classified into the second group (step S551—YES), the information analysis unit 522 determines an addition target A for the maximum predicted value (step S552). The addition target A in FIG. 28 is, for example, the reference OLT 44 among the OLTs 44 classified into the second group. Note that the addition target A may be determined randomly, or may be the OLT 44 with the smallest maximum predicted value, or the OLT 44 with the largest maximum predicted value.

[0280] Next, the information analysis unit 522 determines the summation target B of the predicted maximum value (step S553). The summation target B in FIG. 28 is the OLT 44 other than the summation target A that belongs to the second group, for example, the OLT 44 with the smallest predicted maximum value. The information analysis unit 522 sums the predicted maximum value of the summation target A and the predicted maximum value of the summation target B to determine the total value T ｔｏｔａｌ is calculated (step S554).

[0281] The information analysis unit 522 calculates the total value T ｔｏｔａｌ The information analysis unit 522 compares the calculated total value T ｔｏｔａｌ is compared with the threshold value of the OLT 44 corresponding to the addition target A.

[0282] The information analysis unit 522 calculates the total value T ｔｏｔａｌ The information analysis unit 522 determines whether the total value T ｔｏｔａｌ is not greater than the threshold value (step S555-NO), the information analysis unit 522 calculates a new total value T by adding the predicted maximum values ​​of the OLTs 44 that have not been added among the OLTs 44 classified into the second group. ｔｏｔａｌ For example, the information analysis unit 522 calculates a new total value T by adding the smallest predicted maximum value among the predicted maximum values ​​of the OLTs 44 classified into the second group that have not been added. ｔｏｔａｌ In addition, if the maximum predicted value of an OLT 44 that has not been added among the OLTs 44 classified in the second group is an OLT 44, the information analysis unit 522 may add the value of the maximum predicted value other than the smallest maximum predicted value to obtain a new total value T ｔｏｔａｌmay be calculated.

[0283] Thereafter, the information analysis unit 522 executes the process of step S555 again. In this case, the information analysis unit 522 calculates the newly calculated total value T ｔｏｔａｌ The information analysis unit 522 determines whether the total value T ｔｏｔａｌ is greater than the threshold (step S555-YES), the information analysis unit 522 determines the OLT 44 to be the aggregation destination (step S557). Specifically, the information analysis unit 522 determines the OLT 44 to be the aggregation destination from among the OLTs 44 corresponding to the respective predicted maximum values ​​added up until the threshold was exceeded. For example, the information analysis unit 522 may determine the OLT 44 with the largest predicted maximum value among the OLTs 44 corresponding to the respective predicted maximum values ​​added up until the threshold was exceeded as the aggregation destination OLT 44. Note that the information analysis unit 522 may determine the OLT 44 with the largest traffic volume among the OLTs 44 corresponding to the respective predicted maximum values ​​added up until the threshold was exceeded as the aggregation destination OLT 44.

[0284] As an example, if the OLTs 44 corresponding to the respective predicted maximum values ​​added up before exceeding the threshold are the OLTs 44-1 to 44-3, the information analysis unit 522 determines the OLT 44 with the largest traffic volume from among the OLTs 44-1 to 44-3 as the aggregation destination OLT 44. Here, it is assumed that the OLT 44-1 is determined as the aggregation destination.

[0285] Thereafter, the information analysis unit 522 notifies the control unit 53 of control information including an optical path control instruction and a sleep instruction. The information analysis unit 522 includes, for example, information indicating that the switching source OLTs are OLTs 44-2 and 44-3 and information indicating that the switching destination OLT is OLT 44-1 in the optical path control instruction. The information analysis unit 522 includes, for example, information indicating that the sleep target OLTs are OLTs 44-2 and 44-3.

[0286] The optical path control unit 531 determines the OLT 44 that will be the source of optical path switching and the OLT 44 that will be the destination of optical path switching, based on the optical path control instruction included in the control information notified from the information analysis unit 522. Here, the optical path control unit 531 determines OLT 44-1 as the destination of optical path switching, and determines OLTs 44-2 and 44-3 as the source of optical path switching. The optical path control unit 531 transmits optical path control information including information indicating the destination OLT and source OLT of the determined optical path to the transfer device 43 (step S558).

[0287] As a result, the transfer device 43 switches the optical path route by switching the optical paths heading toward the OLTs 44-2 and 44-3 to head toward the OLT 44-1. Furthermore, the optical path control unit 531 transmits an optical path control instruction to the OLT from which the determined optical path is to be switched (step S559).

[0288] The sleep control unit 532 determines the OLT 44 to be put into sleep mode based on the sleep instruction included in the control information notified from the information analysis unit 522. Here, the sleep control unit 532 determines OLT 44-2 and OLT 44-3 as the sleep targets. The sleep control unit 532 transmits a sleep instruction to each of the determined devices (step S560). This allows the sleep target devices to transition to a sleep state.

[0289] 28 shows a configuration in which sleep control is performed after optical path switching control is performed, but the management control device 50 may perform optical path switching control after sleep control is performed. Furthermore, the processing of step S559 may be executed by the optical path switching function of the transfer device 43.

[0290] Fig. 29 is a flowchart showing an example of the flow of sleep release processing (part 2) executed by the management control device 20 in the third embodiment. Fig. 29 explains a case where sleep release processing is performed on an OLT 44 with irregular traffic transitions (OLT 44 belonging to the second group). Note that, here, traffic information is used as an example of the linkage information. In Fig. 29, the explanation is given assuming M = N = 4. Here, it is assumed that OLTs 44-2 to 44-4 are in sleep mode.

[0291] The acquiring unit 511 acquires the cooperation information from each of the OLTs 44-1 to 44-4 (step S651). The acquiring unit 511 stores the acquired cooperation information for each OLT 44 in the storage unit 521.

[0292] The information analysis unit 522 reads the collaboration information for each OLT 44 stored in the storage unit 521 (step S652). The information analysis unit 522 predicts the traffic volume for each of the OLTs 44-1 to 44-4 based on the collaboration information for each OLT 44 that has been read (step S653). The information analysis unit 522 determines whether there is an OLT 44 for which the predicted traffic volume exceeds a threshold (step S654). The threshold used here may be the same as or different from the threshold used in FIG. 28. For example, the information analysis unit 522 compares the traffic volume predicted for the OLT 44-1 with the threshold for the OLT 44-1 to determine whether the predicted traffic volume exceeds the threshold.

[0293] If the information analysis unit 522 determines that there is no OLT 44 whose predicted traffic volume exceeds the threshold (step S654—NO), the management control device 50 terminates the processing of FIG. 29 . On the other hand, if the information analysis unit 522 determines that there is an OLT 44 whose predicted traffic volume exceeds the threshold (step S654—YES), the information analysis unit 522 determines the OLT 44 to be the target for waking from sleep mode (step S655). Here, it is assumed that the OLT 44 whose traffic volume exceeds the threshold is OLT 44-1. The information analysis unit 522 identifies the other OLT 44 with the largest traffic volume among the traffic volumes aggregated to OLT 44-1 from among the sleeping OLTs 44-2 to 44-4. The identification method is either (Identification Method 1) or (Identification Method 2) described in the first embodiment.

[0294] It is assumed that the OLT 44-2 is identified as the other OLT 44 with the highest traffic volume by any of the above identification methods. The information analysis unit 522 determines the identified OLT 44-2 as the OLT 44 to be released from sleep mode. Thereafter, the information analysis unit 522 notifies the control unit 53 of control information including an optical path control instruction and a sleep release instruction. For example, the information analysis unit 522 includes information indicating that the OLT to be switched to is the OLT 44-2 in the optical path control instruction. For example, the information analysis unit 522 includes information indicating that the OLT to be released from sleep mode is the OLT 44-2.

[0295] The optical path control unit 531 determines the OLT 44 that will be the control target of the optical path based on the optical path control instruction included in the control information notified from the information analysis unit 522. Here, the optical path control unit 531 determines the OLT 44-2 as the control target of the optical path. The optical path control unit 531 transmits optical path control information including information indicating the OLT that will be the control target of the determined optical path to the transfer device 43 (step S656). As a result, the transfer device 43 forms an optical path toward the OLT 44-2.

[0296] The sleep control unit 532 determines the OLT 44 to be released from sleep mode based on the sleep release instruction included in the control information notified from the information analysis unit 522. Here, the sleep control unit 532 determines the OLT 44-2 as the sleep release target. The sleep control unit 532 transmits a sleep release instruction to the determined OLT 44-2 (step S657). This allows the OLT 44-2 to be released from sleep mode.

[0297] The wired network system 300 configured as described above includes a collection unit 51 that acquires cooperation information from a plurality of OLTs 44, and an analysis unit 52 that classifies the plurality of OLTs 44 into a plurality of groups based on the cooperation information, determines one or more OLTs 44 to be subjected to sleep control from among the plurality of OLTs 44 belonging to any of the classified groups, and executes sleep control on the one or more OLTs 44 to be subjected to sleep control. This allows the sleep control to be determined taking into account the cooperation information obtained from each OLT 44. This makes it possible to increase the effect of power saving without degrading communication quality.

[0298] In the wired NW system 300, when the traffic volume suddenly increases, the OLT 44 that is asleep can be started up, thereby enabling power saving without degradation of communication quality.

[0299] In the wired network system 300, when determining whether to wake up the OLTs 44 belonging to the first group, traffic prediction is performed only when the current traffic volume exceeds the total value of the predicted maximum value. In this way, the OLTs 44 belonging to the first group do not need to constantly predict traffic. This allows for reduced power consumption.

[0300] (Variation 1 of the Third Embodiment) The collaboration information may include, for example, information on the number of terminals accommodated in each OLT 44. The collaboration information may include, for example, processing load information of the OLT 44. The processing load information in the third embodiment may be, for example, information on the memory usage rate or CPU usage rate of the OLT 44. The collaboration information may include communication quality information of the terminals 41 connected to each OLT 44.

[0301] When the cooperation information includes information regarding the number of accommodated terminals, the information analysis unit 522 may select a sleep control target (for example, a sleep target or a sleep release target) using the information regarding the number of accommodated terminals. When configured in this manner, the information analysis unit 522 may select an OLT to be a sleep control target, in the same way as when traffic information is used.

[0302] First, the information analysis unit 522 predicts the number of accommodated terminals for a certain period of time for each OLT 44 using information on the past number of accommodated terminals collected from each OLT 44. The information analysis unit 522 classifies each OLT 44 into a plurality of groups based on the prediction result of the number of accommodated terminals. For example, the information analysis unit 522 classifies each OLT 44 into either a first group or a second group. In this case, the first group is a group for which it is determined that the change in the number of accommodated terminals is constant or regular, as a result of the prediction result of the number of accommodated terminals. The second group is a group for which it is determined that the change in the number of accommodated terminals is constant or irregular, as a result of the prediction result of the number of accommodated terminals.

[0303] Thereafter, the information analysis unit 522 aggregates traffic among the multiple OLTs 44 belonging to the first group. For example, the information analysis unit 522 selects the maximum number of accommodated terminals among the predicted numbers of accommodated terminals from each of the multiple OLTs 44 belonging to the first group. As an example, if the multiple OLTs 44 belonging to the first group are OLTs 44-1 to 44-3, the information analysis unit 522 selects the maximum predicted number of terminals for OLT 44-1, the maximum predicted number of terminals for OLT 44-2, and the maximum predicted number of terminals for OLT 44-3, respectively.

[0304] The information analysis unit 522 then sums up the maximum predicted number of terminals for each of the selected OLTs 44-1, 44-2, and 44-3 in order. At this time, the information analysis unit 522 may sum up the maximum predicted number of terminals in ascending order, or in descending order. By summing up in ascending order, it is possible to consolidate many OLTs 44, and in this case, it is possible to transition many OLTs 44 to a sleep state. As a result, it is possible to improve the power saving effect. The information analysis unit 522 sums up the maximum predicted number of terminals up to the point where the threshold is not exceeded.

[0305] If the total value exceeds the threshold, the information analysis unit 522 selects a sleep target based on the maximum predicted number of terminals added up to the time before the threshold is exceeded. For example, the information analysis unit 522 selects the OLT 44 with the maximum predicted number of terminals added up to the time before the threshold is exceeded as a sleep candidate. Similarly, if there are no more maximum predicted number of terminals to add up, the information analysis unit 522 selects a sleep target based on the maximum predicted number of terminals added up to the time before the threshold is exceeded. Before selecting a sleep target, the information analysis unit 522 determines an OLT 44 to be an aggregation destination from among the sleep candidate targets. For example, the information analysis unit 522 may determine the OLT 44 with the largest number of accommodated terminals among the sleep candidate targets as the aggregation destination OLT 44, or the OLT 44 with the largest maximum predicted number of terminals as the aggregation destination OLT 44, or may determine the OLT 44 based on a predetermined priority order. Then, the information analysis unit 522 determines an OLT 44 other than the aggregation destination from among the sleep candidate targets as the sleep target.

[0306] First, the information analysis unit 522 sorts the OLTs 44 in order of the number of accommodated terminals identified by the information on the number of accommodated terminals. Then, the information analysis unit 522 adds up the OLTs 44 with the fewest number of accommodated terminals in order of the number of accommodated terminals. The information analysis unit 522 compares the added total with a threshold and adds up the OLTs 44 with the fewest number of accommodated terminals in order of the number of accommodated terminals until the threshold is exceeded. The information analysis unit 522 selects a sleep target from among the multiple OLTs 44 related to the added number of accommodated terminals, based on the added number of accommodated terminals before the threshold is exceeded. Next, the information analysis unit 522 determines an OLT to be the aggregation destination from among the multiple OLTs 44 related to the added number of accommodated terminals. For example, the information analysis unit 522 determines the OLT 44 that accommodates the most terminals 41 among the added number of accommodated terminals within the range that does not exceed the threshold as the aggregation destination OLT 44. Thereafter, the information analysis unit 522 determines, from among the plurality of OLTs 44 relating to the total number of accommodated terminals, the OLTs 44 other than the aggregation destination as targets for sleep.

[0307] When the collaboration information includes processing load information and communication quality information, the information analysis unit 522 may select a sleep control target (e.g., a sleep target or a sleep release target) using the processing load information or communication quality information in addition to the traffic information. For example, when selecting a sleep control target using communication quality information in addition to traffic information, the information analysis unit 522 determines to perform sleep control when a condition based on the traffic information and a condition based on the communication quality information are satisfied. The condition based on the communication quality information may be, for example, a condition based on whether a path after sleep is feasible (e.g., whether quality degradation occurs). In this case, even if the information analysis unit 522 determines the OLT 44 to be the sleep target and the OLT 44 to be the optical path control target based on a condition based on traffic information, quality degradation may occur after the path is switched. Therefore, even if the information analysis unit 522 determines the OLT 44 to be the sleep target and the OLT 44 to be the optical path control target based on a condition based on traffic information, the information analysis unit 522 may not execute sleep if quality degradation occurs on the path after optical path control.

[0308] At least some or all of the functional units of the management control devices 20, 20a, 20b, and 50, some or all of the functional units of the transfer devices 14, 14a, 14b, and 43, and some or all of the functional units of the OLT 44 are realized as software by a processor such as a central processing unit (CPU) executing a program stored in a storage device having a non-volatile storage medium (non-transitory storage medium) and a storage unit. The program may be recorded on a computer-readable non-transitory storage medium. Examples of computer-readable non-transitory storage media include portable media such as flexible disks, magneto-optical disks, read-only memories (ROMs), and compact disc read-only memories (CD-ROMs), and storage devices such as hard disks built into computer systems.

[0309] At least some or all of the functional units of the management control devices 20, 20a, 20b, 50, some or all of the functional units of the transfer devices 14, 14a, 14b, 43, or some or all of the functional units of the OLT 44 may be realized using hardware including electronic circuits (electronic circuits or circuitry) using, for example, an LSI (Large Scale Integrated circuit), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).

[0310] Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention.

[0311] The present invention can be applied to optical communication systems such as optical access systems.

[0312] 11, 41... terminal, 12, 12-1 to 12-M... radio station, 14, 14a, 14b, 43... forwarding device, 16, 16-1 to 16-N... central office, 17, 17-1 to 17-M... base station, 19... server, 20, 20a, 20b, 50... management control device, 21... collection unit, 22, 52... analysis unit, 23, 23b, 66, 71, 141... control unit, 42, 42-1 to 42-M... ONU, 44, 44-1 to 44-N... OLT, 45... concentrator, 46... core device, 65... optical transmission management control device, 70... wireless transmission management control device, 75... orchestrator, 211, 671, 771... acquisition unit, 221, 521, 681, 731... storage unit, 222, 522, 682, 732... information analysis unit, 231... optical path control unit, 232... sleep control unit, 100, 100a, 100b, 100c, 100d, 100e, 100f, 100g, 200... mobile NW system, 300... wired NW system, 751... signal transfer unit

Claims

1. A control device comprising: a collection unit that acquires coordination information from a plurality of communication stations that are connected to one or more terminals directly or via other devices; and an analysis unit that classifies the plurality of communication stations into a plurality of groups based on the coordination information, determines one or more communication stations to be subject to sleep control from among a plurality of communication stations that belong to any one of the classified groups, and executes sleep control on the determined one or more communication stations to be subject to sleep control.

2. The control device described in claim 1, wherein the coordination information is information on the traffic volume of each communication station, and the analysis unit uses the traffic volume information to predict the traffic volume for a certain period of time for each communication station, and classifies the multiple communication stations into multiple groups based on the traffic volume prediction results.

3. The control device described in claim 2, wherein the analysis unit classifies each of the plurality of communication stations into either a first group in which traffic trends are constant or regular, or a second group in which traffic trends are irregular, based on the results of traffic volume prediction, and determines one or more communication stations within the first group or the second group to be subject to sleep control.

4. The control device described in claim 3, wherein the analysis unit sequentially adds up predicted maximum values, which are values ​​that maximize the traffic volume in the traffic volume prediction results, for either a plurality of communication stations belonging to the first group or a plurality of communication stations belonging to the second group, determines one or more communication stations from which each predicted maximum value obtained before the threshold value was exceeded as candidates for sleep, and determines from among the candidates for sleep, all communication stations other than the communication station with the largest traffic volume, as the one or more communication stations to be put to sleep.

5. The control device according to claim 3 or 4, wherein the analysis unit, for a plurality of communication stations belonging to the first group, if the traffic volume of each of the plurality of communication stations belonging to the first group exceeds the total value of each predicted maximum value of the sleep target candidates, re-predicts the traffic volume of each of the plurality of communication stations belonging to the first group, and determines that sleep awakening is necessary if the predicted traffic volume exceeds a threshold, and, for a plurality of communication stations belonging to the second group, re-predicts the traffic volume of each of the plurality of communication stations belonging to the second group, and determines that sleep awakening is necessary if the predicted traffic volume exceeds a threshold.

6. The control device described in claim 1, wherein the coordination information is information on the number of terminals accommodated by each communication station, and the analysis unit predicts the number of terminals accommodated by each communication station for a certain period of time using the information on the number of terminals accommodated by each communication station, and classifies the multiple communication stations into multiple groups based on the predicted number of terminals accommodated.

7. The control device according to claim 6, wherein the analysis unit classifies each of the multiple communication stations into either a first group in which the trend in the number of accommodated terminals is constant or regular, or a second group in which the trend in the number of accommodated terminals is irregular, based on the prediction result of the number of accommodated terminals, sequentially adds up the predicted maximum capacity values, which are values ​​that maximize the number of accommodated terminals in the prediction result of the number of accommodated terminals, for either the multiple communication stations belonging to the first group or the multiple communication stations belonging to the second group, determines one or more communication stations from which each predicted maximum capacity value was obtained before the threshold was exceeded as candidates to be put to sleep, and determines from among the candidates to be put to sleep, all communication stations other than the communication station with the largest number of accommodated terminals, as the one or more communication stations to be put to sleep.

8. A control method comprising: acquiring coordination information from a plurality of communication stations connected to one or more terminals directly or via other devices; classifying the plurality of communication stations into a plurality of groups based on the coordination information; determining one or more communication stations to be subject to sleep control from among a plurality of communication stations belonging to any one of the plurality of groups; and executing sleep control on the determined one or more communication stations to be subject to sleep control.