Communication system, management and control device, communication station, and control method

Abstract

This communication system comprises: at least one terminal accommodation station that communicates with at least one terminal; a plurality of communication stations connected to the at least one terminal accommodation station directly or through another device; an association information collection unit that acquires, from the communication stations, association information indicating the state of communication between the communication stations and the at least one terminal; an optical path switching control unit that controls switching of an optical path between the at least one terminal accommodation station and the plurality of communication stations when switching of the optical path between the at least one terminal accommodation station and the plurality of communication stations is determined to be necessary on the basis of the association information; and a sleep control unit for causing a communication station, which can be set to sleep, to transition to a sleep state before or after switching of the optical path.　

Description

[Technical Field]

[0001] The present invention relates to a communication system, a management and control device, a communication station, and a control method. This application claims priority based on PCT / JP2022 / 20495, filed in Japan on May 17, 2022, and the contents of that application are incorporated herein by reference. [Background technology]

[0002] In conventional communication systems that perform wireless communication between terminals and base stations, each base station calculates the throughput and automates the system to enter sleep mode when the throughput exceeds a threshold, thereby saving power. In such communication systems, terminals connected to a sleeping base station are instructed to hand over to the base station with the highest throughput. This allows the terminal to continue communicating. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] 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. [Overview of the project] [Problems that the invention aims to solve]

[0004] However, in conventional communication systems, a terminal connected to a sleep base station may be handed over to a base station already connected to many other terminals, potentially leading to a degradation of communication quality. Furthermore, in conventional communication systems, each base station autonomously decides whether or not to enter sleep mode, which can prevent overall optimization and limit the effectiveness of power saving. It should be noted that these problems are not limited to communication systems that use wireless communication between terminals and each base station, but can also occur in communication systems that use wired communication between terminal exchanges connected to terminals via wired connections and the terminals themselves.

[0005] In view of the above circumstances, the present invention aims to provide a technology that can significantly reduce power consumption without degrading communication quality. [Means for solving the problem]

[0006] One aspect of the present invention is a communication system comprising: one or more terminal reception stations that communicate with one or more terminals; a plurality of communication stations connected directly or via other devices to the one or more terminal reception stations; a cooperation information collection unit that acquires cooperation information from the communication stations indicating the status of communication between the communication stations and the one or more terminals; an optical path switching control unit that controls the switching of optical paths between the one or more terminal reception stations and the plurality of communication stations when it is determined that switching of optical paths between the one or more terminal reception stations and the plurality of communication stations is necessary based on the cooperation information; and a sleep control unit that puts communication stations capable of going into sleep mode into sleep mode before or after the switching of optical paths.

[0007] One aspect of the present invention is a management control device comprising: a communication station connected directly or via other devices to one or more terminal reception stations that communicate with one or more terminals; a cooperation information collection unit that acquires cooperation information from the communication station indicating the status of communication with the one or more terminals; an analysis unit that determines whether or not switching of optical paths and sleep control are necessary between the one or more terminal reception stations and the plurality of communication stations based on the cooperation information; an optical path switching control unit that controls the switching of optical paths between the one or more terminal reception stations and the plurality of communication stations when it is determined that switching of optical paths between the one or more terminal reception stations and the plurality of communication stations is necessary; and a sleep control unit that puts communication stations capable of sleep into a sleep state before or after the switching of optical paths is performed.

[0008] One aspect of the present invention is a communication station connected to a terminal exchange that communicates with a terminal, comprising: a transmitting unit that transmits coordination information indicating the status of communication with the terminal to a management control device; a receiving unit that receives an optical path switching instruction indicating that the management control device has determined, based on the coordination information, that it is necessary to switch the optical path between the terminal exchange and the communication station; and a sleep processing unit that enters a sleep state before or after the optical path switching based on the optical path switching instruction is performed.

[0009] One aspect of the present invention is a control method which involves a communication station connected directly or via other devices to one or more terminal stations that communicate with one or more terminals, and which acquires cooperation information from the communication station indicating the status of communication between the one or more terminal stations and the multiple communication stations, and when it is determined based on the cooperation information that switching of optical paths between the one or more terminal stations and the multiple communication stations is necessary, the method controls the switching of optical paths between the one or more terminal stations and the multiple communication stations, and before or after the switching of optical paths is performed, a communication station capable of going into sleep mode is put into sleep mode. [Effects of the Invention]

[0010] This invention makes it possible to significantly reduce power consumption without degrading communication quality. [Brief explanation of the drawing]

[0011] [Figure 1] This diagram illustrates the overall configuration and processing overview of the mobile network system in the embodiment. [Figure 2] This figure shows an example configuration of a mobile network system in the first embodiment. [Figure 3] This flowchart shows an example of the sleep process flow executed by the management control device in the first embodiment. [Figure 4] This flowchart shows an example of the sleep process flow executed by the management control device in the first embodiment. [Figure 5] This sequence diagram shows an example of a detailed flow of the sleep process performed by the mobile network system in the first embodiment. [Figure 6] This flowchart shows an example of the sleep wake-up process performed by the management control device in the first embodiment. [Figure 7] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by the mobile network system in the first embodiment. [Figure 8] This figure shows an example of the configuration of a mobile network system in a modified version of the first embodiment. [Figure 9] This figure shows an example of the configuration of a mobile network system in a modified version of the first embodiment. [Figure 10] This sequence diagram shows an example of a detailed flow of the sleep process performed by a mobile network system in a modified version of the first embodiment. [Figure 11] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by a mobile network system in a modified version of the first embodiment. [Figure 12] This figure shows an example configuration of a mobile network system in the second embodiment. [Figure 13] This flowchart shows an example of the sleep process flow executed by the management control device in the second embodiment. [Figure 14] This flowchart shows an example of the sleep process flow executed by the management control device in the second embodiment. [Figure 15] This sequence diagram shows an example of a detailed flow of the sleep process performed by the mobile network system in the second embodiment. [Figure 16] This flowchart shows an example of the sleep wake-up process performed by the management control device in the second embodiment. [Figure 17] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by the mobile network system in the second embodiment. [Figure 18] This sequence diagram shows an example of a detailed flow of the sleep process performed by a mobile network system in a modified version of the second embodiment. [Figure 19] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by a mobile network system in a modified version of the second embodiment. [Figure 20] This flowchart shows an example of the sleep process flow executed by the management control device in the third embodiment. [Figure 21] This flowchart shows an example of the sleep process flow executed by the management control device in the third embodiment. [Figure 22] This sequence diagram shows an example of a detailed flow of the sleep process performed by the mobile network system in the third embodiment. [Figure 23] This flowchart shows an example of the sleep wake-up process performed by the management control device in the third embodiment. [Figure 24] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by the mobile network system in the third embodiment. [Figure 25] This sequence diagram shows an example of a detailed flow of the sleep process performed by a mobile network system in a modified example of the third embodiment. [Figure 26]This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by a mobile network system in a modified example of the third embodiment. [Figure 27] This figure shows an example configuration of a mobile network system in the fourth embodiment. [Figure 28] This flowchart shows an example of the sleep process flow executed by the management control device in the fourth embodiment. [Figure 29] This flowchart shows an example of the sleep process flow executed by the management control device in the fourth embodiment. [Figure 30] This sequence diagram shows an example of a detailed flow of the sleep process performed by the mobile network system in the fourth embodiment. [Figure 31] This flowchart shows an example of the sleep wake-up process performed by the management control device in the fourth embodiment. [Figure 32] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by the mobile network system in the fourth embodiment. [Figure 33] This sequence diagram shows an example of a detailed flow of the sleep process performed by a mobile network system in a modified version of the fourth embodiment. [Figure 34] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by a mobile network system in a modified version of the fourth embodiment. [Figure 35] This diagram illustrates the overall configuration and processing overview of the wired network system in the embodiment. [Figure 36] This figure shows an example configuration of a wired network system in the fifth embodiment. [Figure 37] This flowchart shows an example of the sleep process flow executed by the management control device in the fifth embodiment. [Figure 38] This flowchart shows an example of the sleep process flow executed by the management control device in the fifth embodiment. [Figure 39]This sequence diagram shows an example of a detailed flow of the sleep process performed by the wired network system in the fifth embodiment. [Figure 40] This flowchart shows an example of the sleep wake-up process performed by the management control device in the fifth embodiment. [Figure 41] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by the wired network system in the fifth embodiment. [Figure 42] This figure shows an example of the configuration of a wired network system in a modified version of the fifth embodiment. [Figure 43] This figure shows an example of the configuration of a wired network system in a modified version of the fifth embodiment. [Figure 44] This sequence diagram shows an example of a detailed flow of the sleep process performed by a wired network system in a modified version of the fifth embodiment. [Figure 45] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by a wired network system in a modified version of the fifth embodiment. [Figure 46] This figure shows an example configuration of a wired network system in the sixth embodiment. [Figure 47] This flowchart shows an example of the sleep process flow executed by the management control device in the sixth embodiment. [Figure 48] This flowchart shows an example of the sleep process flow executed by the management control device in the sixth embodiment. [Figure 49] This sequence diagram shows an example of a detailed flow of the sleep process performed by the wired network system in the sixth embodiment. [Figure 50] This flowchart shows an example of the sleep wake-up process performed by the management control device in the sixth embodiment. [Figure 51] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by the wired network system in the sixth embodiment. [Figure 52]This sequence diagram shows an example of a detailed flow of the sleep process performed by a wired network system in a modified version of the sixth embodiment. [Figure 53] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by a wired network system in a modified version of the sixth embodiment. [Figure 54] This flowchart shows an example of the sleep process flow executed by the management control device in the seventh embodiment. [Figure 55] This flowchart shows an example of the sleep process flow executed by the management control device in the seventh embodiment. [Figure 56] This sequence diagram shows an example of a detailed flow of the sleep process performed by the wired network system in the seventh embodiment. [Figure 57] This flowchart shows an example of the sleep wake-up process performed by the management control device in the seventh embodiment. [Figure 58] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by the wired network system in the seventh embodiment. [Figure 59] This sequence diagram shows an example of a detailed flow of the sleep process performed by a wired network system in a modified version of the seventh embodiment. [Figure 60] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by a wired network system in a modified version of the seventh embodiment. [Figure 61] This figure shows an example configuration of a wired network system in the eighth embodiment. [Figure 62] This flowchart shows an example of the sleep process flow executed by the management control device in the eighth embodiment. [Figure 63] This flowchart shows an example of the sleep process flow executed by the management control device in the eighth embodiment. [Figure 64] This sequence diagram shows an example of a detailed flow of the sleep process performed by the wired network system in the eighth embodiment. [Figure 65]This flowchart shows an example of the sleep wake-up process performed by the management control device in the eighth embodiment. [Figure 66] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by the wired network system in the eighth embodiment. [Figure 67] This sequence diagram shows an example of a detailed flow of the sleep process performed by a wired network system in a modified version of the eighth embodiment. [Figure 68] This sequence diagram shows an example of a detailed flow of the sleep wake-up process performed by a wired network system in a modified version of the eighth embodiment. [Modes for carrying out the invention]

[0012] One embodiment of the present invention will be described below with reference to the drawings. (Overall configuration and processing overview of the mobile network system) Figure 1 is a diagram illustrating the overall configuration and processing overview of a mobile network system in an embodiment. First, the overall configuration of the mobile network system will be described. A mobile network system is an example of a communication system. A mobile network system is, for example, a fifth-generation mobile communication system (hereinafter referred to as "5G"). The mobile network system comprises one or more radio stations 12, a switching device 13, a plurality of distributed stations 14, an aggregation station 15, a core device 16, and a management control device 20.

[0013] The following connections are made via optical fibers that transmit optical signals: between the radio station 12 and the switching device 13, between the switching device 13 and the distributed stations 14, between the distributed stations 14 and the aggregation station 15, and between the aggregation station 15 and the core device 16. The following connections are made via electrical wires or optical fibers that transmit electrical signals: between the switching device 13 and the management control device 20, and between the distributed stations 14 and the management control device 20. The example shown in Figure 1 shows a case where there are four radio stations 12 and two distributed stations 14. Note that there may be multiple switching devices 13, but the following explanation will use the case of one device as an example.

[0014] Each radio station 12 is equipped with one or more antennas and communicates wirelessly with the terminal 11. For example, each radio station 12 receives a signal transmitted from the terminal 11 and transmits the received signal to the distributed station 14 connected via the switching device 13. Each radio station 12 transmits the received signal to the terminal 11 via the switching device 13. A radio station 12 is, for example, a Radio Unit (RU) in the 5G communication standard. A radio station 12 is one form of a terminal access station.

[0015] The switching device 13 is installed between the radio station 12 and the distributed station 14. The switching device 13 switches the optical path according to instructions from the management control device 20. An optical path is a path for optical signals. By switching the optical path, the switching device 13 switches the connection between the radio station 12 and the distributed station 14.

[0016] The distributed station 14 receives the uplink signal transmitted by the radio station 12 via the switching device 13. The distributed station 14 transmits the downlink signal to the radio station 12 via the switching device 13. The uplink signal is the signal transmitted by the terminal 11, and the downlink signal is the signal destined for the terminal 11. Each distributed station 14 transitions to a sleep state according to instructions from the management control device 20. The sleep state is a state in which power saving is possible by disabling some functions. The distributed station 14 is, for example, a DU (Distributed Unit) in the 5G communication standard. The information that the management control device 20 obtains from the distributed station 14 is called cooperation information. Cooperation information is information that indicates the status of communication between each distributed station 14 and the terminal 11. The distributed station 14 is one form of a communication station.

[0017] The coordination information includes, for example, information on the number of terminals 11 that can be accommodated by each distributed station 14 (hereinafter referred to as "number of accommodated terminals"). The coordination information includes, for example, information on the maximum number of accommodated terminals of the distributed station 14. The maximum number of accommodated terminals of the distributed station 14 is the maximum number that the distributed station 14 can accommodate. The coordination information includes, for example, information on the radio stations 12 to which the optical path distributed station 14 is connected (hereinafter referred to as "connected radio station information"). The coordination information includes, for example, information on the processing load of the distributed station 14 (hereinafter referred to as "processing load information"). The processing load information may be, for example, information on the memory usage rate of the distributed station 14 or information on the CPU (Central Processing Unit) usage rate. The coordination information includes, for example, information on the processing delay for each distributed station 14 (hereinafter referred to as "processing delay information"). The coordination information includes, for example, information on the transmission delay between terminal 11 and each distributed station 14 (hereinafter referred to as "delay information").

[0018] The aggregation station 15 aggregates the uplink signals transmitted by each distributed station 14. The aggregation station 15 distributes the downlink signals. The aggregation station 15 is, for example, a CU (Centralized Unit) in the 5G communication standard.

[0019] The core device 16 performs signal processing on the uplink signals aggregated by the aggregation station 15. The core device 16 transmits the resulting signals to the external network. The core device 16 receives signals from the external network.

[0020] The core device 16 performs predetermined signal processing on signals received from an external network. The core device 16 transmits the resulting signal as a downlink signal to the aggregation station 15. The signal processing is, for example, the transfer of user data in the UPF (User Plane Function) of the 5G core network.

[0021] The management control device 20 acquires coordination information from the distributed station 14. Based on the acquired coordination information, the management control device 20 determines whether optical path switching and sleep control are necessary. If the management control device 20 determines that optical path switching and sleep control are necessary, it performs optical path switching control processing and sleep control processing. Optical path switching control processing is the process of switching the optical path between the radio station 12 and the distributed station 14. For example, the management control device 20 instructs the switching device 13 to control the switching of the optical path between the radio station 12 and the distributed station 14. Sleep control processing is the process of executing or waking the distributed station 14 from sleep.

[0022] Next, I will explain the overview of the mobile network system's processing. The upper diagram in Figure 1 shows the connection status of the mobile network system before the optical path switchover, and the lower diagram in Figure 1 shows the connection status of the mobile network system after the optical path switchover. The upper diagram in Figure 1 shows an example where radio stations 12-1 and 12-2 are connected to distributed station 14-1, and radio stations 12-3 and 12-4 are connected to distributed station 14-2.

[0023] The management control device 20 determines whether or not to perform optical path switching control processing based on the coordination information collected from each distributed station 14. The management control device 20 determines to perform optical path switching control processing if there is a distributed station 14 that can transition to a sleep state. A distributed station 14 that can transition to a sleep state is, for example, a distributed station 14 that does not contain a terminal 11.

[0024] On the other hand, the management control device 20 determines that it will not perform optical path switching control processing if there are no distributed stations 14 that can transition to sleep mode. If the management control device 20 determines that it will perform optical path switching control processing, it instructs the switching device 13 to switch the optical path. The switching device 13 switches the optical path between the radio station 12 and the distributed stations 14 according to the instructions from the management control device 20. After the optical path switching is complete, the switching device 13 notifies the management control device 20 that the optical path switching is complete.

[0025] When the management control device 20 receives notification from the switching device 13 that the optical path switching is complete, it sends a sleep permission notification to the distributed stations 14 that are ready to enter sleep mode. The sleep permission notification is a signal that includes instructions to put the distributed stations 14 into sleep mode. As a result, the distributed stations 14 that are ready to enter sleep mode enter sleep mode.

[0026] The lower diagram in Figure 1 shows an example where radio stations 12-1 to 12-4 are connected to distributed station 14-1, and distributed station 14-2 has entered a sleep state. In this way, the mobile NW system 100 puts a distributed station 14 that can enter a sleep state into a sleep state by having a terminal 11 connected to a distributed station 14 that can enter a sleep state connect to another distributed station 14, based on the coordination information collected from each distributed station 14. Hereinafter, the distributed station 14 that can enter a sleep state will be referred to as the source distributed station, and the distributed station 14 that becomes the new connection destination for the terminal 11 connected to the source distributed station will be referred to as the destination distributed station.

[0027] (First embodiment) Figure 2 shows an example configuration of the mobile network system 100 in the first embodiment. The mobile network system 100 in the first embodiment includes one or more radio stations 12, a switching device 13, a plurality of distributed stations 14, an aggregation station 15, a core device 16, and a management control device 20. The radio stations 12, switching device 13, distributed stations 14, aggregation station 15, and core device 16 were explained in Figure 1, so their explanation is omitted here. The management control device 20 includes a collaborative information collection unit 21, an analysis unit 22, and a control unit 23.

[0028] The collaborative information collection unit 21 includes an acquisition unit 211. The acquisition unit 211 collects collaborative information from the distributed stations 14 at predetermined intervals.

[0029] The analysis unit 22 comprises a cooperation information storage unit 221 and a real-time analysis unit 222. The cooperation information storage unit 221 records the collected cooperation information in a predetermined storage device. The real-time analysis unit 222 analyzes the communication status between each distributed station 14 and the terminal 11, such as the amount of change in the number of connections of the distributed stations 14 per unit time, based on the cooperation information. Specifically, the real-time analysis unit 222 determines whether or not optical path switching and sleep control are necessary based on the cooperation information.

[0030] For example, the real-time analysis unit 222 determines that optical path switching and sleep control are necessary if all terminals 11 accommodated by the source distributed station can be accommodated by another distributed station 14. In this case, the real-time analysis unit 222 notifies the control unit 23 of information indicating the destination distributed station 14 for the optical path switching and information indicating the distributed station 14 to be put into sleep mode.

[0031] For example, the real-time analysis unit 222 determines that switching of the optical path and sleep control are necessary when the number of terminals 11 accommodated by the distributed station 14 exceeds the maximum number of terminals. In this case, the real-time analysis unit 222 notifies the control unit 23 of information indicating the distributed station 14 to which the optical path will be switched, and information indicating the distributed station 14 to which sleep mode will be disabled.

[0032] The control unit 23 includes an optical path switching control unit 231 and a sleep control unit 232. The optical path switching control unit 231 determines the distributed station 14 to which the optical path will be switched based on the analysis results of the real-time analysis unit 222, and instructs the switching device 13 to switch the optical path. For example, the optical path switching control unit 231 determines the distributed station 14 to which the optical path will be switched based on information indicating the distributed station 14 to which the optical path will be switched, which is notified by the real-time analysis unit 222.

[0033] The sleep control unit 232 instructs the distributed station 14 to either enter or exit sleep mode based on the analysis results of the real-time analysis unit 222.

[0034] Figure 3 is a flowchart showing an example of the sleep process flow executed by the management control device 20 in the first embodiment. In Figure 3, the example is explained in which the cooperation information includes at least the number of terminals accommodated by each distributed station 14 and the maximum number of terminals accommodated. The process flow in Figure 3 is executed repeatedly at a predetermined cycle.

[0035] The acquisition unit 211 acquires cooperation information from each distributed station 14 (step S101). The acquisition unit 211 stores the acquired cooperation information for each distributed station 14 in the cooperation information storage unit 221 (step S102). The real-time analysis unit 222 calculates the number of additional terminals that each distributed station 14 can accommodate based on the cooperation information for each distributed station 14 stored in the cooperation information storage unit 221 (step S103). Here, the number of additional terminals that can be accommodated represents the number of additional terminals 11 that can be accommodated in addition to the number of terminals currently accommodated by the distributed station 14. For example, the number of additional terminals that can be accommodated can be obtained by subtracting the number of currently accommodated terminals from the maximum number of accommodated terminals.

[0036] The real-time analysis unit 222 determines whether the first switching condition has been met (step S104). The first switching condition is a condition indicating that a switch in the optical path between the radio station 12 and the distributed station 14 is necessary, for example, that the number of additional terminals that a certain distributed station 14 can accommodate is greater than the number of terminals that the distributed station 14 subject to sleep determination can accommodate.

[0037] If the real-time analysis unit 222 determines that the first switching condition has been met (step S104-YES), it notifies the control unit 23 of an optical path switching instruction and a sleep control instruction. Based on the optical path switching instruction notified by the real-time analysis unit 222, the optical path switching control unit 231 instructs the switching device 13 to switch the optical path of the radio station 12 connected to the source distributed station (step S105). Specifically, the optical path switching control unit 231 instructs the optical path of the radio station 12 connected to the source distributed station to be directed towards the destination distributed station.

[0038] The sleep control unit 232 transmits a sleep permission notification to the source distributed station (step S106). For example, the sleep control unit 232 may transmit a sleep instruction to the source distributed station when it receives an optical path switching completion notification from the radio station 12 connected to the source distributed station and the destination distributed station. The optical path switching completion notification is a signal that includes information indicating that the optical path switching has been completed. This allows the source distributed station to enter sleep mode.

[0039] In step S104, if the real-time analysis unit 222 determines that the first switching condition is not met (step S104-NO), it determines whether there are other distributed stations 14 (step S107). Other distributed stations 14 are, for example, distributed stations 14 that have not been compared with the distributed station 14 that is the target of the sleep determination. If the real-time analysis unit 222 determines that there are no other distributed stations 14 (step S107-NO), it terminates the process.

[0040] On the other hand, if the real-time analysis unit 222 determines that there are other distributed stations 14 (step S107-YES), it selects information on the number of additional terminals that can be accommodated by the other distributed stations 14 (step S108). Using the selected information on the number of additional terminals that can be accommodated by the other distributed stations 14, the real-time analysis unit 222 executes the process in step S104 again.

[0041] Figure 4 is a flowchart showing an example of the sleep process flow executed by the management control device 20 in the first embodiment. The process shown in Figure 4 is described in more detail as a more specific version of the process shown in Figure 3.

[0042] The acquisition unit 211 acquires information from each distributed station 14 as linked information, including the maximum number of terminals each distributed station can accommodate, information on connected radio stations, and the number of terminals each distributed station can accommodate (step S201).

[0043] The acquisition unit 211 stores the acquired cooperation information for each distributed station 14 in the cooperation information storage unit 221 (step S202). The real-time analysis unit 222 calculates the additional number of terminals that can be accommodated in each distributed station 14 based on the cooperation information for each distributed station 14 stored in the cooperation information storage unit 221 (step S203). Next, the real-time analysis unit 222 substitutes a value of 1 for the constant i (step S204). i represents, for example, the distributed station 14-i that is the switching destination. When i = 1, the distributed station 14-1 becomes the switching destination distributed station. i takes a value of 1 ≤ i ≤ I. I is the total number of distributed stations 14.

[0044] Next, the real-time analysis unit 222 substitutes the value of (i + 1) for k (step S205). k represents, for example, the distributed station 14-k that is the switching source. When k = 2 (i = 1), the distributed station 14-2 becomes the switching source distributed station. k takes a value of 2 ≤ k ≤ K. K is the total number of distributed stations 14 - 1, that is, K = (I - 1).

[0045] After that, the real-time analysis unit 222 i -u i >u k determines whether it is satisfied (step S206). U i represents the maximum number of terminals that can be accommodated in the distributed station 14-i, u i represents the number of terminals accommodated in the distributed station 14-i, and u k represents the number of terminals accommodated in the distributed station 14-k. U i -u i >u k The condition represented by is a specific example of the first switching condition. Here, as an example, assume that the maximum number of terminals that can be accommodated in the distributed station 14-1 is 1000, the number of terminals accommodated in the distributed station 14-1 is 100, the maximum number of terminals that can be accommodated in the distributed station 14-2 is 800, and the number of terminals accommodated in the distributed station 14-2 is 200.

[0046] When i = 1 and k = 2, it is represented as follows. ·U1 - u1 ⇒ 1000 - 100 = 900

[0047] Based on the results described above, U1-u1>u2 is 900>200, and the first switching condition is met. The real-time analysis unit 222 checks the first switching condition (for example, U i -u i >u k If it is determined that the condition is met (step S206-YES), the control unit 23 is notified of an instruction to switch the optical path and an instruction to control sleep.

[0048] The optical path switching control unit 231 instructs the switching device 13 to switch the optical path of the radio station 12 connected to the distributed station 14-k based on the optical path switching instruction notified by the real-time analysis unit 222 (step S207). Specifically, the optical path switching control unit 231 instructs the optical path of the radio station 12 connected to the distributed station 14-k (e.g., distributed station 14-2) to be directed toward the destination distributed station, distributed station 14-i (e.g., distributed station 14-1). The sleep control unit 232 sends a sleep permission notification to the distributed station 14-k (e.g., distributed station 14-2) (step S208).

[0049] On the other hand, consider, as an example, the case where the maximum number of terminals that distributed station 14-1 can accommodate is 1000, the number of terminals that distributed station 14-1 can accommodate is 500, the maximum number of terminals that distributed station 14-2 can accommodate is 800, and the number of terminals that distributed station 14-2 can accommodate is 700. When i=1 and k=2, it can be expressed as follows. U1 - u1 ⇒ 1000 - 500 = 500

[0050] Based on the results described above, U1-u1>u2 becomes 500<700, and the first switching condition is not met. The real-time analysis unit 222 checks the first switching condition (for example, U i -u i >u k If it is determined that the condition is not met (step S206-NO), then it is determined whether k is the maximum value (step S209).

[0051] If the real-time analysis unit 222 determines that k is not the maximum value (step S209-NO), it adds 1 to the value of k (step S210). Then, the real-time analysis unit 222 executes the process in step S206 again. For example, as in the example above, if i=1, k=2 and k is not the maximum value, the real-time analysis unit 222 adds 1 to the value of k to make k=3. Then, the real-time analysis unit 222 determines whether U1-u1>u3 is satisfied.

[0052] On the other hand, if the real-time analysis unit 222 determines that k is at its maximum value (step S209-YES), it determines whether i is at its maximum value (step S211). If the real-time analysis unit 222 determines that i is at its maximum value (step S211-YES), it terminates the process.

[0053] On the other hand, if the real-time analysis unit 222 determines that i is not the maximum value (step S211-NO), it adds 1 to the value of i (step S212). After that, the real-time analysis unit 222 executes the process in step S205 again. For example, if i=1 and k=3, and k is the maximum value but i is not the maximum value, the real-time analysis unit 222 adds 1 to the value of i to make i=2.

[0054] Then, in the process of step S205, the real-time analysis unit 222 substitutes the value of (i+1) for k (step S205). In this case, i=2 and k=3. After that, in the process of step S206, the real-time analysis unit 222 determines whether or not U2-u2>u3 is satisfied.

[0055] Figure 5 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the mobile network system 100 in the first embodiment. In the explanation of Figure 5, distributed station 14-1 is assumed to be the destination distributed station, and distributed station 14-2 is assumed to be the source distributed station. Here, they will be referred to as destination distributed station 14-1 and source distributed station 14-2.

[0056] The acquisition unit 211 of the management control device 20 acquires coordination information from the switching destination distributed station 14-1 and the switching source distributed station 14-2 at predetermined intervals (steps S301 and S302). The acquisition unit 211 stores the acquired coordination information in the coordination information storage unit 221. When the coordination information is stored in the coordination information storage unit 221, the real-time analysis unit 222 makes a decision on switching the optical path and sleep control (step S303).

[0057] The decision to switch the optical path and perform sleep control in step S303 is to determine whether or not the first switching condition in step S104 has been met. Here, let's assume that the first switching condition in step S104 has been met. If the first switching condition has been met, the real-time analysis unit 222 instructs the optical path switching control unit 231 to perform optical path switching control and instructs the sleep control unit 232 to perform sleep control.

[0058] The optical path switching control unit 231 notifies the switching device 13 and the aggregation station 15 of the optical path switching destination information (step S304). The optical path switching destination information is information regarding the destination of the optical path. In the example shown in Figure 5, the optical path switching destination information includes information indicating the destination distributed station 14-1 as the destination of the optical path. When the switching device 13 receives the optical path switching destination information from the management control device 20, it instructs the radio station 12 connected to the source distributed station 14-2, the destination distributed station 14-1, and the source distributed station 14-2 to switch the optical path (step S305). For example, the switching device 13 instructs the radio station 12 connected to the source distributed station 14-2 to switch the optical path to the destination distributed station 14-1, instructs the destination distributed station 14-1 to switch so that the optical path is connected to the radio station 12 connected to the source distributed station 14-2, and instructs the source distributed station 14-2 not to set an optical path.

[0059] The radio station 12 connected to the source distributed station 14-2, the destination distributed station 14-1, and the source distributed station 14-2 prepare for the optical path switching (steps S306, S307, and S308). The radio station 12 connected to the source distributed station 14-2, the destination distributed station 14-1, and the source distributed station 14-2 transmit an optical path switching response notification to the switching device 13 (steps S309, S310, and S311). The optical path switching response notification is a signal that includes information indicating that the optical path switching destination information has been received.

[0060] When the switching device 13 receives an optical path switching response notification from the source distributed station 14-2, it sends an optical path switching start notification to the radio station 12 connected to the radio station 12 connected to the source distributed station 14-2, and to the destination distributed station 14-1 (step S312). The optical path switching start notification is a signal that includes a command to start switching the optical path.

[0061] The radio station 12 connected to the source distribution station 14-2 and the destination distribution station 14-1 switch their optical paths in response to receiving the optical path switching start notification (steps S313, S314). This process switches the optical path of the radio station 12 connected to the source distribution station 14-2 to point towards the destination distribution station 14-1. In other words, the radio station 12 and the destination distribution station 14-1 become able to communicate with each other.

[0062] The destination distributed station 14-1 transmits a route switching request to the core device 16 (step S315). A route switching request is a signal that includes a request for switching of the communication path in the core device 16. The core device 16 switches the path in response to receiving the route switching request (step S316).

[0063] Once the route switching is complete, the core device 16 sends a route switching response notification to the destination distributed station 14-1 (step S317). The route switching response notification is a signal that indicates that the switching of the communication route in the core device 16 is complete.

[0064] When the optical path switching is complete, the radio station 12 transmits an optical path switching completion notification to the control device 20 (step S318). The optical path switching completion notification is a signal that includes information indicating that the optical path switching has been completed. When the destination distributed station 14-1 has completed the optical path switching, it transmits an optical path switching completion notification to the control device 20 (step S319).

[0065] When the sleep control unit 232 receives an optical path switching completion notification from the destination of the optical path switching start notification, it sends a sleep permission notification to the switching source distributed station 14-2 (step S320). When the switching source distributed station 14-2 receives the sleep permission notification from the management control device 20, it sends a sleep response notification to the management control device 20 (step S321). The sleep response notification is a signal that includes information indicating that the sleep permission notification has been received. After sending the sleep response notification, the switching source distributed station 14-2 enters a sleep state (step S322).

[0066] Figure 6 is a flowchart showing an example of the sleep wake-up process performed by the management control device 20 in the first embodiment. The acquisition unit 211 acquires information on the number of connected terminals and the sleeping distributed stations 14-k from each distributed station 14 as linked information (step S401). The acquisition unit 211 notifies the analysis unit 22 of the acquired information on the number of connected terminals and the sleeping distributed stations 14-k.

[0067] The real-time analysis unit 222 reads information from the cooperation information storage unit 221 regarding the maximum number of terminals each distributed station 14 can accommodate and information regarding the radio station 12 that was connected to the sleeping distributed station 14-k (step S402). Based on the cooperation information for each distributed station 14 stored in the cooperation information storage unit 221, the real-time analysis unit 222 calculates the number of additional terminals that each distributed station 14 can accommodate (step S403).

[0068] Next, the real-time analysis unit 222 substitutes the value 1 for the constant i (step S404). The real-time analysis unit 222 then performs the analysis. i <ui Determine whether the condition is met (step S405). i i The conditions shown are specific examples of the first sleep wake-up conditions. The real-time analysis unit 222 determines the first sleep wake-up conditions (for example, U i i If it is determined that the condition is met (step S405-YES), it is determined that the sleeping distributed station 14-k needs to be woken up and the optical path needs to be switched.

[0069] The real-time analysis unit 222 notifies the control unit 23 of the determination result. Based on the determination result, the sleep control unit 232 sends an instruction to the distributed station 14-k that is in sleep mode to wake it up (step S406). The optical path switching control unit 231 obtains information about the radio station 12 that was connected to the distributed station 14-k before sleep mode from the information obtained in step S402. The optical path switching control unit 231 instructs the radio station 12 that was connected to the distributed station 14-k before sleep mode to change its connection to the distributed station 14-k.

[0070] In the process of step S405, the real-time analysis unit 222 determines the first sleep release condition (for example, U i i If it is determined that the condition is not met (step S405-NO), it is determined whether i is the maximum value (step S408). If the real-time analysis unit 222 determines that i is the maximum value (step S408-YES), it terminates the process.

[0071] On the other hand, if the real-time analysis unit 222 determines that i is not the maximum value (step S408-NO), it adds the value of 1 to the value of i (step S409). After that, the real-time analysis unit 222 executes the process in step S405 again.

[0072] ​​​Here, in the process of FIG. 6, specific numerical values will be used for explanation. As an example, the total number of distributed stations 14 is 2 (I = 2), the maximum number of terminals that can be accommodated by distributed station 14-1 is 1000, the number of terminals accommodated by distributed station 14-1 is 800, the maximum number of terminals that can be accommodated by distributed station 14-2 is 800, and the number of terminals accommodated by distributed station 14-2 is 1000.

[0073] When i = 1, U1 < u1 is 1000 > 800, and the first sleep release condition is not satisfied. The real-time analysis unit 222 determines that the first sleep release condition (for example, U i <u i ) is not satisfied (step S405 - NO), and determines whether i is the maximum value (step S408). Currently, since i = 1, the real-time analysis unit 222 determines that i is not the maximum value.

[0074] The real-time analysis unit 222 adds a value of 1 to the value of i to make i = 2. The real-time analysis unit 222 executes the process of step S405 again. When i = 2, U2 < u2 is 800 < 1000, and the first sleep release condition is satisfied. Thereafter, the processes of steps S406 and S407 are executed.

[0075] FIG. 7 is a sequence diagram showing an example of the detailed flow of the sleep release process executed by the mobile NW system 100 in the first embodiment. In the description of FIG. 7, it is assumed that the distributed station 14-2 is in the sleep state.

[0076] The distributed station 14-2 is in the sleep state (step S501). The acquisition unit 211 of the management control device 20 acquires the cooperation information from the distributed station 14-1 at a predetermined cycle (step S502). The acquisition unit 211 stores the acquired cooperation information in the cooperation information storage unit 221. When the cooperation information is stored in the cooperation information storage unit 221, the real-time analysis unit 222 performs optical path switching and sleep control determination (step S503). The optical path switching and sleep control determination in step S503 is whether the sleep release condition is satisfied. Here, it is assumed that the sleep release condition is satisfied.

[0077] The sleep control unit 232 of the management control device 20 transmits a sleep wake-up notification to the distributed station 14-2 (step S504). The sleep wake-up notification is a signal that includes content indicating that the sleep state is being released. Upon receiving the sleep wake-up notification, the distributed station 14-2 transmits a sleep wake-up response notification to the management control device 20 (step S505). The sleep wake-up response notification is a signal that includes content indicating that the sleep wake-up notification has been received.

[0078] The optical path switching control unit 231 notifies the switching device 13 and the aggregation station 15 of the optical path switching destination information (step S506). When the switching device 13 receives the optical path switching destination information from the management control device 20, it instructs the radio station 12, the distributed station 14-1, and the distributed station 14-2 to switch the optical path (step S507).

[0079] Radio station 12, distributed station 14-1, and distributed station 14-2 prepare for optical path switching (steps S508, S509, and S510). Once preparation for optical path switching is complete, radio station 12, distributed station 14-1, and distributed station 14-2 send an optical path switching response notification to the switching device 13 indicating that preparation for switching is complete (steps S511, S512, and S513).

[0080] When the switching device 13 receives optical path switching response notifications from the radio station 12, the distributed station 14-1, and the distributed station 14-2, it sends an optical path switching start notification to the radio station 12, the distributed station 14-1, and the distributed station 14-2 (step S514).

[0081] Radio station 12, distributed station 14-1, and distributed station 14-2 switch optical paths in response to receiving an optical path switching start notification (steps S515, S516, and S517). Distributed station 14-1 sends a route switching request to core device 16 (step S518). Core device 16 switches routes in response to receiving the route switching request (step S519). Once the route switching is complete, core device 16 sends a route switching response notification to distributed station 14-1 (step S520).

[0082] When the optical path switching is complete, the radio station 12 sends an optical path switching completion notification to the control unit 20 (step S521). When the optical path switching is complete, the distributed station 14-1 sends an optical path switching completion notification to the control unit 20 (step S522). When the optical path switching is complete, the distributed station 14-2 sends an optical path switching completion notification to the control unit 20 (step S523).

[0083] The mobile network system 100 configured as described above includes one or more radio stations 12 that communicate wirelessly with one or more terminals 11, multiple distributed stations 14 connected to the one or more radio stations 12 via a switching device 13, a cooperation information collection unit 21 that acquires cooperation information indicating the communication status between the multiple distributed stations 14 and one or more terminals 11 at predetermined intervals, an optical path switching control unit 231 that controls the switching of optical paths between the one or more radio stations 12 and the multiple distributed stations 14 when it is determined that switching of optical paths between the one or more radio stations 12 and the multiple distributed stations 14 is necessary based on the cooperation information, and a sleep control unit 232 that puts distributed stations capable of going into sleep mode after the optical path switching has been performed. This allows for optical path switching and sleep control while analyzing the load of each distributed station 14. Therefore, it is possible to significantly reduce power consumption without degrading communication quality.

[0084] (Modification 1 in the first embodiment) In the embodiment described above, the management control device 20 is configured to directly acquire cooperation information from the distributed stations 14. The management control device 20 may acquire cooperation information via other devices. Here, other devices are, for example, wireless controllers. Figure 8 is a diagram showing an example configuration of a mobile network system 100a in Modification 1 of the first embodiment. The mobile network system 100a comprises one or more wireless stations 12, a switching device 13, a plurality of distributed stations 14, an aggregation station 15, a core device 16, a management control device 20, and a wireless controller 30a. As shown in Figure 8, in the mobile network system 100a, a wireless controller 30a is provided between the management control device 20 and the distributed stations 14.

[0085] The wireless controller 30a acquires cooperation information from each distributed station 14 at predetermined intervals via wireless communication. The wireless controller 30a transmits the acquired cooperation information to the management control device 20 via wireless communication. Alternatively, the wireless controller 30a may receive a sleep control instruction from the management control device 20 and transmit it to the switching source distributed station. This configuration allows for the collection of collaborative information via wireless communication.

[0086] (Modification 2 in the first embodiment) In the embodiment described above, the management control device 20 is configured to perform optical path switching control processing and sleep control processing. Alternatively, the switching device 13 may be configured to perform optical path switching control processing and sleep control processing. Figure 9 is a diagram showing an example configuration of a mobile NW system 100b in a modified example 2 of the first embodiment. The mobile NW system 100b comprises one or more radio stations 12, a switching device 13b, a plurality of distributed stations 14, an aggregation station 15, a core device 16, and a management control device 20b.

[0087] As shown in Figure 9, the switching device 13b includes a control unit 23, while the management control device 20b does not include a control unit 23. The real-time analysis unit 222 of the management control device 20b notifies the switching device 13b of the analysis results. The real-time analysis unit 222 may also notify the switching device 13b of the analysis results only when optical path switching and sleep control are performed. The control unit 23 of the switching device 13b performs optical path switching control processing and sleep control processing based on the analysis results notified from the management control device 20b.

[0088] Figure 10 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the mobile NW system 100b in a modified example 2 of the first embodiment. In Figure 10, processes similar to those in Figure 5 are denoted by the same reference numerals as in Figure 5 and their explanation is omitted. In the explanation of Figure 10, distributed station 14-1 is assumed to be the destination distributed station, and distributed station 14-2 is assumed to be the source distributed station. Here, they will be referred to as destination distributed station 14-1 and source distributed station 14-2.

[0089] After the processes from step S301 to step S303 are executed, the real-time analysis unit 222 instructs the switching device 13b to perform optical path switching control and sleep control if the first switching condition is met (step S601). The switching device 13b receives the instruction transmitted from the management control device 20b.

[0090] The optical path switching control unit 231 of the switching device 13b determines the destination of the optical path from the information contained in the received instruction (step S602). The optical path switching control unit 231 notifies the aggregation station 15 of the optical path switching destination information (step S603). Subsequently, the optical path switching control unit 231 instructs the radio station 12 connected to the source distributed station 14-2, the destination distributed station 14-1, and the source distributed station 14-2 to switch the optical path (step S604). After that, the processes from steps S306 to S317 are executed.

[0091] When the optical path switching is complete, the radio station 12 sends an optical path switching completion notification to the switching device 13b (step S605). The radio station 12 may also send the optical path switching completion notification to the management control device 20b. When the switching destination distributed station 14-1 is complete, it sends an optical path switching completion notification to the switching device 13b (step S606). The radio station 12 may also send the optical path switching completion notification to the management control device 20b.

[0092] When the sleep control unit 232 of the switching device 13b receives an optical path switching completion notification from the destination of the optical path switching start notification, it sends a sleep permission notification to the switching source distributed station 14-2 (step S607). When the switching source distributed station 14-2 receives the sleep permission notification from the switching device 13b, it sends a sleep response notification to the switching device 13b (step S608). After sending the sleep response notification, the switching source distributed station 14-2 enters a sleep state (step S322).

[0093] Figure 11 is a sequence diagram showing an example of a detailed flow of the sleep wake-up process performed by the mobile NW system 100b in a modified example 2 of the first embodiment. In Figure 11, processes similar to those in Figure 7 are denoted by the same reference numerals as in Figure 7 and their explanation is omitted. In the explanation of Figure 11, it is assumed that the distributed station 14-2 is in a sleep state.

[0094] After the processes from step S501 to step S503 are executed, the real-time analysis unit 222 instructs the switching device 13b to perform optical path switching control and sleep control if the sleep release conditions are met (step S701). The switching device 13b receives the instruction transmitted from the management control device 20b.

[0095] The sleep control unit 232 of the switching device 13b transmits a sleep wake notification to the distributed station 14-2 based on the information contained in the received instruction (step S702). In response to receiving the sleep wake notification, the distributed station 14-2 transmits a sleep wake response notification to the switching device 13b (step S703).

[0096] The optical path switching control unit 231 of the switching device 13b determines the destination of the optical path from the information contained in the received instruction (step S704). The optical path switching control unit 231 of the switching device 13b notifies the aggregation station 15 of the optical path switching destination information (step S705). Subsequently, the processes from steps S507 to S520 are executed.

[0097] When the optical path switching is complete, radio station 12 sends an optical path switching completion notification to switching device 13b (step S706). When the optical path switching is complete, distributed station 14-1 sends an optical path switching completion notification to switching device 13b (step S707). When the optical path switching is complete, distributed station 14-2 sends an optical path switching completion notification to switching device 13b (step S708).

[0098] (Second embodiment) The second embodiment differs from the first embodiment in that it further includes processing load information (for example, information on memory usage or CPU usage for each distributed station) as collaborative information. In the second embodiment, as an example of processing load information, information on memory usage for each distributed station will be explained.

[0099] Figure 12 shows an example configuration of the mobile network system 100c in the second embodiment. The mobile network system 100c in the second embodiment comprises one or more radio stations 12, a switching device 13, a plurality of distributed stations 14, an aggregation station 15, a core device 16, and a management control device 20c. The management control device 20c comprises a collaborative information collection unit 21c, an analysis unit 22c, and a control unit 23.

[0100] The collaborative information collection unit 21c comprises an acquisition unit 211 and a distributed station monitoring unit 212c. The distributed station monitoring unit 212c monitors each distributed station 14 and measures the memory usage rate for each distributed station 14. The distributed station monitoring unit 212c outputs the memory usage rate information measured for each distributed station 14 as collaborative information to the analysis unit 22c.

[0101] The analysis unit 22c comprises a collaboration information storage unit 221 and a real-time analysis unit 222c. Based on the collaboration information, the real-time analysis unit 222c analyzes the communication status in the mobile NW system 100c, such as the change in the number of connections of the distributed station 14 per unit time. Specifically, the real-time analysis unit 222c divides the memory usage rate by the current number of connected terminals to estimate the memory usage rate per unit. Furthermore, the real-time analysis unit 222c multiplies the number of connected terminals of other distributed stations 14 by the memory usage rate per unit of the target distributed station 14, and determines optical path switching and sleep mode if the memory usage rate does not exceed 100% and the number of connected terminals of that distributed station 14 is less than the number of additional terminals that the target distributed station 14 can accommodate.

[0102] Figure 13 is a flowchart showing an example of the sleep process flow executed by the management control device 20c in the second embodiment. In Figure 13, processes similar to those in Figure 3 are denoted by the same reference numerals as in Figure 3, and their explanation is omitted.

[0103] The collaboration information collection unit 21c acquires collaboration information from each distributed station 14 (step S801). Specifically, the acquisition unit 211 acquires information such as the number of connected terminals and the maximum number of connected terminals from each distributed station 14 as collaboration information. Furthermore, the distributed station monitoring unit 212c measures the memory usage rate for each distributed station 14. The collaboration information collection unit 21c stores the acquired collaboration information for each distributed station 14 in the collaboration information storage unit 221 (step S802). Specifically, the collaboration information collection unit 21c stores information such as the number of connected terminals and the maximum number of connected terminals from each distributed station 14, as well as information on the memory usage rate for each distributed station 14, in the collaboration information storage unit 221 as collaboration information.

[0104] The real-time analysis unit 222c calculates the number of additional terminals that each distributed station 14 can accommodate based on the cooperation information for each distributed station 14 stored in the cooperation information storage unit 221 (step S803). Furthermore, the real-time analysis unit 222c estimates the memory usage rate of each distributed station 14 based on the cooperation information for each distributed station 14 stored in the cooperation information storage unit 221 (step S804).

[0105] The real-time analysis unit 222c determines whether the second switching condition has been met (step S805). The second switching condition is a condition indicating that a switch in the optical path between the radio station 12 and the distributed station 14 is necessary, for example, that the number of additional terminals that a certain distributed station 14 can accommodate is greater than the number of terminals that the distributed station 14 subject to sleep determination can accommodate, and that the memory usage rate does not exceed 100%.

[0106] If the real-time analysis unit 222c determines that the second switching condition is met (step S805-YES), it executes the processes from step S105 onwards. On the other hand, if the real-time analysis unit 222c determines that the second switching condition is not met (step S805-NO), it executes the processes from step S107 onwards.

[0107] Figure 14 is a flowchart showing an example of the sleep process flow executed by the management control device 20c in the second embodiment. The process shown in Figure 14 is described in more detail than the process shown in Figure 13. In Figure 14, processes similar to those in Figure 4 are denoted by the same reference numerals as in Figure 4 and their explanation is omitted.

[0108] The acquisition unit 211 acquires information from each distributed station 14 as linked information, including the maximum number of terminals each distributed station can accommodate, connected radio station information, and the number of terminals each distributed station can accommodate. Furthermore, the distributed station monitoring unit 212c acquires information on the memory usage rate of each distributed station 14 (step S901).

[0109] The acquisition unit 211 stores the acquired cooperation information for each distributed station 14 in the cooperation information storage unit 221. The distributed station monitoring unit 212c stores the acquired memory usage information for each distributed station 14 as cooperation information (step S902). The real-time analysis unit 222c calculates the number of additional terminals that each distributed station 14 can accommodate based on the cooperation information for each distributed station 14 stored in the cooperation information storage unit 221 (step S903). Furthermore, the real-time analysis unit 222c estimates the memory usage rate per unit of each distributed station 14 based on the cooperation information for each distributed station 14 stored in the cooperation information storage unit 221 (step S904).

[0110] Next, the real-time analysis unit 222c substitutes the value 1 for the constant i (step S905). Next, the real-time analysis unit 222c substitutes the value (i+1) for k (step S906). After that, the real-time analysis unit 222c calculates 100-M i >m i ×u k , and U i -u i >u k Determine whether the condition is met (step S907). i This represents the memory usage of distributed station 14-i, and m i This represents the memory usage rate per unit for each of the 14 distributed stations. i This is calculated in the process of step S904. 100-M i >m i ×u k , and U i -u i >u k The conditions shown are specific examples of the second switching condition.

[0111] If the real-time analysis unit 222c determines that the second switching condition is met (step S907-YES), it executes the processing from step S207 onwards. On the other hand, if the real-time analysis unit 222c determines that the second switching condition is not met (step S907-NO), it executes the processing from step S209 onwards.

[0112] Here, we will explain the process in Figure 14 using specific numerical values. As an example, suppose that the maximum number of terminals accommodated by distributed station 14-1 is 1000, the number of terminals accommodated by distributed station 14-1 is 100, the memory usage rate M1 of distributed station 14-1 is 20%, the maximum number of terminals accommodated by distributed station 14-2 is 800, the number of terminals accommodated by distributed station 14-2 is 200, and the memory usage rate M2 of distributed station 14-2 is 30%. In this case, in the process of step S904, the real-time analysis unit 222c calculates m1=20 / 100=0.2 and m2=30 / 200=0.15 as approximate values ​​for the memory usage rate per unit of distributed station 14. m1 represents the approximate value for the memory usage rate per unit of distributed station 14-1, and m2 represents the approximate value for the memory usage rate per unit of distributed station 14-2.

[0113] The real-time analysis unit 222c processes 100-M in step S907. i >m i ×u k , and U i -u i >u k We determine whether the condition is met. If i=1 and k=2, it can be expressed as follows. ·100-M i ⇒100-20=80 ·m i ×u k ⇒ 0.2 × 200 = 40 ·U i -u i ⇒1000-100=900

[0114] Based on the results described above, 100-M i >m i ×u k , and U i -u i >u kThe conditions are 180 > 40 and 900 > 200. In this case, the real-time analysis unit 222c determines that the second switching condition has been met. Therefore, the real-time analysis unit 222c decides to switch the radio station 12 connected to distributed station 14-2 to distributed station 14-1, and decides to put distributed station 14-2 into sleep mode. The real-time analysis unit 222c notifies the optical path switching control unit 231 of the result of its decision to switch the radio station 12 connected to distributed station 14-2 to distributed station 14-1, and notifies the sleep control unit 232 of its decision to put distributed station 14-2 into sleep mode.

[0115] As a result, the optical path switching control unit 231 controls the switching of the optical path to connect the radio station 12 connected to the distributed station 14-2 to the distributed station 14-1, in accordance with the notification from the real-time analysis unit 222c. The sleep control unit 232 controls the sleep state to put the distributed station 14-2 into a sleep state, in accordance with the notification from the real-time analysis unit 222c.

[0116] Figure 15 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the mobile NW system 100c in the second embodiment. In Figure 15, processes similar to those in Figure 5 are denoted by the same reference numerals as in Figure 5, and their explanation is omitted. In the explanation of Figure 15, distributed station 14-1 is assumed to be the destination distributed station, and distributed station 14-2 is assumed to be the source distributed station. Here, they will be referred to as destination distributed station 14-1 and source distributed station 14-2.

[0117] The cooperation information collection unit 21c of the management control device 20c acquires cooperation information from the switching destination distributed station 14-1 and the switching source distributed station 14-2 at predetermined intervals (steps S1001 and S1002). The cooperation information acquired in steps S1001 and S1002 includes at least information on the number of connected terminals, information on the maximum number of connected terminals, and information on the memory usage rate for each distributed station 14. The cooperation information collection unit 21c stores the acquired cooperation information in the cooperation information storage unit 221.

[0118] When the real-time analysis unit 222c stores the linkage information storage unit 221, it performs optical path switching and sleep control determination (step S1003). The optical path switching and sleep control determination in step S1003 is a determination of whether or not the second switching condition in step S805 has been met. Here, let's assume that the second switching condition in step S805 has been met. If the second switching condition has been met, the real-time analysis unit 222c executes the processing from step S304 onwards.

[0119] Figure 16 is a flowchart showing an example of the sleep wake-up process performed by the management control device 20c in the second embodiment. In Figure 16, processes similar to those in Figure 6 are denoted by the same reference numerals as in Figure 6, and their explanation is omitted.

[0120] The acquisition unit 211 acquires information on the number of connected terminals and the number of sleeping distributed stations 14-k from each distributed station 14 as linked information. Furthermore, the distributed station monitoring unit 212c acquires information on the memory usage rate for each distributed station 14 as linked information (step S1101). The acquisition unit 211 notifies the analysis unit 22c of the acquired information on the number of connected terminals, the number of sleeping distributed stations 14-k, and the memory usage rate.

[0121] The real-time analysis unit 222c of the analysis unit 22c reads information from the cooperation information storage unit 221 about the maximum number of terminals that each distributed station 14 can accommodate and information about the radio station 12 that was connected to the sleeping distributed station 14-k (step S1102). Based on the cooperation information for each distributed station 14 obtained, the real-time analysis unit 222c calculates the number of additional terminals that each distributed station 14 can accommodate (step S1103).

[0122] Next, the real-time analysis unit 222c substitutes the value 1 for the constant i (step S1104). The real-time analysis unit 222c then performs the analysis. i i , or T1 <M i Determine whether any of the following conditions are met (step S1105). i i , or T1 <M i ​​The conditions shown are specific examples of the second sleep wake-up condition. In the second sleep wake-up condition, T1 <M i The memory usage of distributed station 14-i is M i This means that the value has exceeded the threshold T1 (for example, a predetermined value such as 80%, 90%, or 100%).

[0123] The real-time analysis unit 222c determines the second sleep wake-up condition (for example, U i i , or T1 <M i If it is determined that the condition is met (step S1105-YES), it is determined that switching of the optical path and waking up the sleeping distributed station 14-k are necessary.

[0124] The real-time analysis unit 222c notifies the control unit 23 of the determination result. Subsequently, the processing from step S406 onwards is executed. Meanwhile, the real-time analysis unit 222c determines the second sleep release condition (for example, U i i , or T1 <M i If it is determined that the condition is not met (step S1105-NO), the process in step S408 is executed.

[0125] Figure 17 is a sequence diagram showing an example of a detailed flow of the sleep wake-up process performed by the mobile NW system 100c in the second embodiment. In Figure 17, processes similar to those in Figure 7 are denoted by the same reference numerals as in Figure 7, and their explanation is omitted. In the explanation of Figure 17, it is assumed that the distributed station 14-2 is in a sleep state.

[0126] Distributed station 14-2 is in a sleep state (step S501). The cooperation information collection unit 21c of the management control device 20c acquires cooperation information from distributed station 14-1 at predetermined intervals (step S1201). The cooperation information acquired in step S1201 includes at least information on the number of connected terminals, information on the maximum number of connected terminals, etc., as well as information on the memory usage rate for each distributed station 14. The cooperation information collection unit 21c stores the acquired cooperation information in the cooperation information storage unit 221.

[0127] ​​ When the real-time analysis unit 222c stores the linkage information storage unit 221, it performs optical path switching and sleep control determination (step S1202). The optical path switching and sleep control determination in step S1202 is whether or not the sleep release condition has been met. Here, let's assume that the sleep release condition has been met. If the sleep release condition has been met, the real-time analysis unit 222c executes the processing from step S504 onwards.

[0128] The mobile network system 100c in the second embodiment configured as described above can achieve the same effects as the first embodiment. Specifically, in the mobile network system 100c, the management control device 20c further acquires information on the memory usage rate of each distributed station 14 as cooperation information, and determines whether or not to switch optical paths based on the cooperation information. If the management control device 20c determines that switching optical paths is necessary, it controls the switching of optical paths between one or more radio stations 12 and multiple distributed stations 14. Furthermore, after the optical path switching has been performed, the management control device 20c puts distributed stations that can enter sleep mode into sleep mode. This allows for the control of optical path switching and sleep mode while analyzing the load of each distributed station 14. Therefore, it becomes possible to significantly reduce power consumption without degrading communication quality.

[0129] (Modification 1 in the second embodiment) In the embodiment described above, the management control device 20c is configured to directly acquire cooperation information from the distributed station 14. The management control device 20c may also acquire cooperation information via other devices. Here, other devices are, for example, wireless controllers. In this configuration, the mobile NW system 100c is newly equipped with a wireless controller 30a, and the wireless controller 30a is provided between the management control device 20c and the distributed station 14.

[0130] The wireless controller 30a acquires cooperation information from each distributed station 14 at predetermined intervals via wireless communication. The wireless controller 30a transmits the acquired cooperation information to the management control device 20c via wireless communication. Alternatively, the wireless controller 30a may receive a sleep control instruction from the management control device 20c and transmit it to the switching source distributed station. This configuration allows for the collection of collaborative information via wireless communication.

[0131] (Modification 2 in the second embodiment) In the embodiment described above, the management control device 20c is configured to perform optical path switching control processing and sleep control processing. In contrast, the switching device 13 may be configured to perform optical path switching control processing and sleep control processing. In this configuration, the switching device 13 includes a control unit 23, while the management control device 20c does not include a control unit 23. The real-time analysis unit 222c of the management control device 20c notifies the switching device 13 of the analysis results. The real-time analysis unit 222c may notify the switching device 13 of the analysis results only when optical path switching and sleep control are performed. The control unit 23 of the switching device 13 performs optical path switching control processing and sleep control processing based on the analysis results notified by the management control device 20c.

[0132] Figure 18 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the mobile NW system 100c in a modified example 2 of the second embodiment. In Figure 18, processes similar to those in Figure 15 are denoted by the same reference numerals as in Figure 15 and their descriptions are omitted.

[0133] After the processes from step S1001 to step S1003 are executed, the real-time analysis unit 222c instructs the switching device 13b to perform optical path switching control and sleep control if the second switching condition is met (step S1301). The switching device 13b receives the instruction transmitted from the management control device 20c.

[0134] The optical path switching control unit 231 of the switching device 13b determines the destination of the optical path from the information contained in the received instruction (step S1302). The optical path switching control unit 231 notifies the aggregation station 15 of the optical path switching destination information (step S1303). Subsequently, the optical path switching control unit 231 instructs the radio station 12 connected to the source distributed station 14-2, the destination distributed station 14-1, and the source distributed station 14-2 to switch the optical path (step S1304). After that, the processes from steps S306 to S317 are executed.

[0135] When the optical path switching is complete, radio station 12 sends an optical path switching completion notification to switching device 13b (step S1305). Radio station 12 may also send the optical path switching completion notification to management control device 20c. When the switching destination distributed station 14-1 is complete, it sends an optical path switching completion notification to switching device 13 (step S1306). Radio station 12 may also send the optical path switching completion notification to management control device 20c.

[0136] When the sleep control unit 232 of the switching device 13b receives an optical path switching completion notification from the destination of the optical path switching start notification, it sends a sleep permission notification to the switching source distributed station 14-2 (step S1307). When the switching source distributed station 14-2 receives the sleep permission notification from the switching device 13, it sends a sleep response notification to the switching device 13b (step S1308). After sending the sleep response notification, the switching source distributed station 14-2 enters a sleep state (step S322).

[0137] Figure 19 is a sequence diagram showing an example of a detailed flow of the sleep wake-up process performed by the mobile NW system 100c in a modified example 2 of the second embodiment. In Figure 19, processes similar to those in Figure 17 are denoted by the same reference numerals as in Figure 17 and their explanation is omitted. Note that in the explanation of Figure 17, it is assumed that the distributed station 14-2 is in a sleep state.

[0138] After steps S501, S1201, and S1202 are executed, the real-time analysis unit 222c instructs the switching device 13b to perform optical path switching control and sleep control if the sleep release conditions are met (step S1401). The switching device 13b receives the instruction transmitted from the management control device 20c.

[0139] The sleep control unit 232 of the switching device 13b transmits a sleep wake notification to the distributed station 14-2 based on the information contained in the received instruction (step S1402). In response to receiving the sleep wake notification, the distributed station 14-2 transmits a sleep wake response notification to the switching device 13b (step S1403).

[0140] The optical path switching control unit 231 of the switching device 13b determines the destination of the optical path from the information contained in the received instruction (step S1404). The optical path switching control unit 231 of the switching device 13b notifies the aggregation station 15 of the optical path switching destination information (step S1405). Subsequently, the processes from steps S507 to S520 are executed.

[0141] When the optical path switching is complete, the radio station 12 sends an optical path switching completion notification to the switching device 13b (step S1406). When the optical path switching is complete, the distributed station 14-1 sends an optical path switching completion notification to the switching device 13b (step S1407). When the optical path switching is complete, the distributed station 14-2 sends an optical path switching completion notification to the switching device 13b (step S1408).

[0142] (Third embodiment) In the third embodiment, the configuration differs from the second embodiment in that the linked information further includes processing load information (for example, information on memory usage or CPU usage for each distributed station) and processing delay information for each distributed station. The system configuration is the same as in the second embodiment. In the third embodiment, as an example of processing load information, information on memory usage for each distributed station will be explained as an example.

[0143] The management control device 20c determines optical path switching and sleep based on information on the number of terminals for each distributed station 14, information on the memory usage rate for each distributed station 14, and information on the processing delay for each distributed station 14. For example, the distributed station monitoring unit 212c monitors each distributed station 14 and measures the memory usage rate for each distributed station 14. Furthermore, the distributed station monitoring unit 212c monitors each distributed station 14 and collects processing delay information for each distributed station 14. The distributed station monitoring unit 212c outputs the memory usage information measured for each distributed station 14 and the processing delay information for each distributed station 14 as linked information to the analysis unit 22c.

[0144] Figure 20 is a flowchart showing an example of the sleep process flow executed by the management control device 20c in the third embodiment. In Figure 20, processes similar to those in Figure 13 are denoted by the same reference numerals as in Figure 13 and their descriptions are omitted.

[0145] The collaboration information collection unit 21c acquires collaboration information from each distributed station 14 (step S1501). Specifically, the acquisition unit 211 acquires information such as the number of connected terminals and the maximum number of connected terminals from each distributed station 14 as collaboration information. Furthermore, the distributed station monitoring unit 212c measures the memory usage rate for each distributed station 14 and acquires processing delay information for each distributed station 14. The collaboration information collection unit 21c stores the acquired collaboration information for each distributed station 14 in the collaboration information storage unit 221 (step S1502). Specifically, in addition to the collaboration information including information such as the number of connected terminals and the maximum number of connected terminals from each distributed station 14, the collaboration information collection unit 21c stores information on the memory usage rate for each distributed station 14 and processing delay information for each distributed station 14 as collaboration information in the collaboration information storage unit 221.

[0146] The real-time analysis unit 222c calculates the number of additional terminals that each distributed station 14 can accommodate based on the cooperation information for each distributed station 14 stored in the cooperation information storage unit 221 (step S1503). Furthermore, the real-time analysis unit 222c estimates the memory usage rate of each distributed station 14 based on the cooperation information for each distributed station 14 stored in the cooperation information storage unit 221 (step S1504).

[0147] The real-time analysis unit 222c determines whether the third switching condition has been met (step S1505). The third switching condition is a condition that indicates that a switch in the optical path between the radio station 12 and the distributed station 14 is necessary, for example, that the number of additional terminals that a certain distributed station 14 can accommodate is greater than the number of terminals that the distributed station 14 subject to sleep determination can accommodate, that the memory usage rate does not exceed 100%, and that the processing delay of the distributed station 14 subject to sleep determination does not exceed a threshold.

[0148] If the real-time analysis unit 222c determines that the third switching condition is met (step S1505-YES), it executes the processes from step S105 onwards. On the other hand, if the real-time analysis unit 222c determines that the third switching condition is not met (step S1505-NO), it executes the processes from step S107 onwards.

[0149] Figure 21 is a flowchart showing an example of the sleep process flow executed by the management control device 20c in the third embodiment. The process shown in Figure 21 is described in more detail as the process shown in Figure 20. In Figure 21, processes similar to those in Figure 14 are denoted by the same reference numerals as in Figure 14 and their explanation is omitted.

[0150] The acquisition unit 211 acquires information from each distributed station 14 as linked information, including the maximum number of terminals each distributed station can accommodate, connected radio station information, and the number of terminals each distributed station can accommodate. Furthermore, the distributed station monitoring unit 212c acquires information on the memory usage rate and processing delay information of each distributed station 14 (step S1601).

[0151] The acquisition unit 211 stores the acquired cooperation information for each of the distributed stations 14 in the cooperation information storage unit 221. Further, the distributed station monitoring unit 212c stores the acquired information on the memory usage rate and the processing delay information of each distributed station 14 as cooperation information (step S1602). The real-time analysis unit 222c calculates the additional number of terminals that can be accommodated for each distributed station 14 based on the cooperation information for each distributed station 14 stored in the cooperation information storage unit 221 (step S1603). Further, the real-time analysis unit 222c estimates the memory usage rate per unit of each distributed station 14 based on the cooperation information for each distributed station 14 stored in the cooperation information storage unit 221 (step S1604).

[0152] Next, the real-time analysis unit 222c substitutes a value of 1 for the constant i (step S1605). Next, the real-time analysis unit 222c substitutes the value of (i + 1) for k (step S1606). Thereafter, the real-time analysis unit 222c performs 100 - M i >m i ×u k and, U i -u i >u k and, T > t i to determine whether it is satisfied (step S1607). T represents a threshold value, and t i in the third embodiment represents the processing delay of the distributed station 14 - i. 100 - M i >m i ×u k and, U i -u i >u k and, T > t i The conditions shown by are specific examples of the third switching condition.

[0153] When the real-time analysis unit 222c determines that the third switching condition is satisfied (step S1607 - YES), it executes the processing after step S207. On the other hand, when the real-time analysis unit 222c determines that the third switching condition is not satisfied (step S16°7 - NO), it executes the processing after step S209.

[0154] Figure 22 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the mobile NW system 100c in the third embodiment. In Figure 22, processes similar to those in Figure 15 are denoted by the same reference numerals as in Figure 15 and their explanation is omitted. In the explanation of Figure 22, distributed station 14-1 is assumed to be the destination distributed station, and distributed station 14-2 is assumed to be the source distributed station. Here, they will be referred to as destination distributed station 14-1 and source distributed station 14-2.

[0155] The cooperation information collection unit 21c of the management control device 20c acquires cooperation information from the switching destination distributed station 14-1 and the switching source distributed station 14-2 at predetermined intervals (steps S1701 and S1702). The cooperation information acquired in steps S1701 and S1702 includes at least information on the number of connected terminals, information on the maximum number of connected terminals, etc., as well as information on the memory usage rate for each distributed station 14 and processing delay information for each distributed station 14. The cooperation information collection unit 21c stores the acquired cooperation information in the cooperation information storage unit 221.

[0156] When the real-time analysis unit 222c has accumulated the linkage information in the linkage information storage unit 221, it performs optical path switching and sleep control determination (step S1703). The optical path switching and sleep control determination in step S1703 is a determination of whether or not the third switching condition in step S1505 has been met. Here, let's assume that the third switching condition in step S1505 has been met. If the fifth switching condition has been met, the real-time analysis unit 222c executes the processing from step S304 onwards.

[0157] Figure 23 is a flowchart showing an example of the sleep wake-up process performed by the management control device 20c in the third embodiment. In Figure 23, processes similar to those in Figure 16 are denoted by the same reference numerals as in Figure 16 and their descriptions are omitted.

[0158] The acquisition unit 211 acquires, from each distributed station 14, the information on the number of accommodated terminals and the information on the distributed stations 14-k that are in the sleep state as cooperation information. Further, the distributed station monitoring unit 212c acquires, as cooperation information, the information on the memory usage rate for each distributed station 14 and the processing delay information for each distributed station 14 (step S1751). The acquisition unit 211 notifies the analysis unit 22c of the acquired information on the number of accommodated terminals, the information on the distributed stations 14-k that are in the sleep state, the information on the memory usage rate, and the processing delay information for each distributed station 14.

[0159] The real-time analysis unit 222c of the analysis unit 22c reads, from the cooperation information storage unit 221, the information on the maximum number of accommodated terminals for each distributed station 14 and the information on the radio stations 12 connected to the distributed stations 14-k that are in the sleep state (step S1752). The real-time analysis unit 222c calculates the additional number of terminals that can be accommodated for each distributed station 14 based on the acquired cooperation information for each distributed station 14 (step S1753).

[0160] Next, the real-time analysis unit 222c substitutes a value of 1 into the constant i (step S1754). The real-time analysis unit 222c determines whether any of U i <u i , or, T1 < M i , or, T < t i is satisfied (step S1755). U i <u i , or, T1 < M i , or, T < t i The conditions represented by are specific examples of the third sleep release condition. In the third sleep release condition, T < t i means that the processing delay of the distributed station 14-i has exceeded the threshold value.

[0161] When the real-time analysis unit 222c determines that the third sleep release condition (for example, U i <u i , or, T1 < M i , or, T < t i ) is satisfied (step S1755 - YES), it determines that it is necessary to switch the optical path and release the sleep state of the distributed stations 14-k that are in the sleep state.

[0162] The real-time analysis unit 222c notifies the control unit 23 of the determination result. Subsequently, the processing from step S406 onwards is executed. Meanwhile, the real-time analysis unit 222c determines the third sleep release condition (for example, U i i , or T1 <M i , or T <t i If it is determined that the condition is not met (step S1755-NO), the process in step S408 is executed.

[0163] Figure 24 is a sequence diagram showing an example of a detailed flow of the sleep wake-up process performed by the mobile NW system 100c in the third embodiment. In Figure 24, processes similar to those in Figure 17 are denoted by the same reference numerals as in Figure 17 and their explanation is omitted. Note that in the explanation of Figure 17, it is assumed that the distributed station 14-2 is in a sleep state.

[0164] Distributed station 14-2 is in a sleep state (step S501). The cooperation information collection unit 21c of the management control device 20c acquires cooperation information from distributed station 14-1 at predetermined intervals (step S1801). The cooperation information acquired in step S1801 includes information on the memory usage rate and processing delay information for each distributed station 14. The cooperation information collection unit 21c stores the acquired cooperation information in the cooperation information storage unit 221.

[0165] When the real-time analysis unit 222c stores the linkage information storage unit 221, it performs optical path switching and sleep control determination (step S1802). The optical path switching and sleep control determination in step S1802 is whether or not the sleep release condition has been met. Here, let's assume that the sleep release condition has been met. If the sleep release condition has been met, the real-time analysis unit 222c executes the processing from step S504 onwards.

[0166] ​The mobile NW system 100c in the third embodiment configured as described above can achieve the same effects as the first embodiment. Specifically, in the mobile NW system 100c in the third embodiment, the management control device 20c further acquires information on the memory usage rate of each distributed station 14 and processing delay information for each distributed station 14 as cooperation information, and determines whether or not to switch optical paths based on the cooperation information. If the management control device 20c determines that switching optical paths is necessary, it controls the switching of optical paths between one or more radio stations 12 and multiple distributed stations 14. Furthermore, after the optical path switching has been performed, the management control device 20c puts distributed stations that can enter sleep mode into sleep mode. This allows for the control of optical path switching and sleep mode while analyzing the load of each distributed station 14. Therefore, it becomes possible to significantly reduce power consumption without degrading communication quality.

[0167] (Modification 1 in the third embodiment) In the embodiment described above, the management control device 20c is configured to directly acquire cooperation information from the distributed station 14. The management control device 20c may also acquire cooperation information via other devices. Here, other devices are, for example, wireless controllers. In this configuration, the mobile NW system 100c is newly equipped with a wireless controller 30a, and the wireless controller 30a is provided between the management control device 20c and the distributed station 14.

[0168] The wireless controller 30a acquires cooperation information from each distributed station 14 at predetermined intervals via wireless communication. The wireless controller 30a transmits the acquired cooperation information to the management control device 20c via wireless communication. Alternatively, the wireless controller 30a may receive a sleep control instruction from the management control device 20c and transmit it to the switching source distributed station. This configuration allows for the collection of collaborative information via wireless communication.

[0169] (Modification 2 in the third embodiment) In the embodiment described above, the management control device 20c is configured to perform optical path switching control processing and sleep control processing. In contrast, the switching device 13 may be configured to perform optical path switching control processing and sleep control processing. In this configuration, the switching device 13 includes a control unit 23, while the management control device 20c does not include a control unit 23. The real-time analysis unit 222c of the management control device 20c notifies the switching device 13 of the analysis results. The real-time analysis unit 222c may notify the switching device 13 of the analysis results only when optical path switching and sleep control are performed. The control unit 23 of the switching device 13 performs optical path switching control processing and sleep control processing based on the analysis results notified by the management control device 20c.

[0170] Figure 25 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the mobile NW system 100c in a modified example 2 of the third embodiment. In Figure 25, processes similar to those in Figure 22 are denoted by the same reference numerals as in Figure 22 and their descriptions are omitted.

[0171] After the processes from step S1701 to step S1703 are executed, the real-time analysis unit 222c instructs the switching device 13b to perform optical path switching control and sleep control if the third switching condition is met (step S1901). The switching device 13b receives the instruction transmitted from the management control device 20c.

[0172] The optical path switching control unit 231 of the switching device 13b determines the destination of the optical path from the information contained in the received instruction (step S1902). The optical path switching control unit 231 notifies the aggregation station 15 of the optical path switching destination information (step S1903). Subsequently, the optical path switching control unit 231 instructs the radio station 12 connected to the source distributed station 14-2, the destination distributed station 14-1, and the source distributed station 14-2 to switch the optical path (step S1904). After that, the processes from steps S306 to S317 are executed.

[0173] When the optical path switching is completed, the radio station 12 transmits an optical path switching completion notification to the switching device 13b (step S1905). Note that the radio station 12 may also transmit the optical path switching completion notification to the management control device 20c. When the optical path switching is completed, the switching destination distributed station 14-1 transmits an optical path switching completion notification to the switching device 13 (step S1906). Note that the radio station 12 may also transmit the optical path switching completion notification to the management control device 20c.

[0174] When the sleep control unit 232 included in the switching device 13b receives an optical path switching completion notification from the transmission destination of the optical path switching start notification, it transmits a sleep permission notification to the switching source distributed station 14-2 (step S1907). When the switching source distributed station 14-2 obtains a sleep permission notification from the switching device 13, it transmits a sleep response notification to the switching device 13b (step S1908). After transmitting the sleep response notification, the switching source distributed station 14-2 shifts to the sleep state (step S322).

[0175] FIG. 26 is a sequence diagram showing an example of the detailed flow of the sleep release process executed by the mobile NW system 100c in the second modification of the third embodiment. In FIG. 26, the same processes as those in FIG. 23 are denoted by the same reference numerals as in FIG. 23, and the description thereof is omitted.

[0176] After the processes of step S501, step S1801, and step S1802 are executed, when the sleep release condition is satisfied, the real-time analysis unit 222c instructs the switching device 13b to perform optical path switching control and sleep control (step S2001). The switching device 13b receives the instruction transmitted from the management control device 20c.

[0177] Based on the information included in the received instruction, the sleep control unit 232 of the switching device 13b transmits a sleep release notification to the distributed station 14-2 (step S2002). In response to the reception of the sleep release notification, the distributed station 14-2 transmits a sleep release response notification to the switching device 13b (step S2003).

[0178] The optical path switching control unit 231 of the switching device 13b determines the destination of the optical path from the information contained in the received instruction (step S2004). The optical path switching control unit 231 of the switching device 13b notifies the aggregation station 15 of the optical path switching destination information (step S2005). Subsequently, the processes from steps S507 to S520 are executed.

[0179] When the optical path switching is complete, radio station 12 sends an optical path switching completion notification to switching device 13b (step S2006). When the optical path switching is complete, distributed station 14-1 sends an optical path switching completion notification to switching device 13b (step S2007). When the optical path switching is complete, distributed station 14-2 sends an optical path switching completion notification to switching device 13b (step S2008).

[0180] (Fourth embodiment) In the fourth embodiment, the configuration differs from the first embodiment in that the cooperation information further includes information on the transmission delay between the terminal 11 and each distributed station 14.

[0181] Figure 27 shows an example configuration of the mobile network system 100d in the fourth embodiment. The mobile network system 100d in the fourth embodiment comprises one or more radio stations 12, a switching device 13, a plurality of distributed stations 14, an aggregation station 15, a core device 16, and a management control device 20d. The management control device 20d comprises a collaborative information collection unit 21d, an analysis unit 22d, and a control unit 23.

[0182] The collaborative information collection unit 21d comprises an acquisition unit 211 and a delay measurement unit 213d. The delay measurement unit 213d measures the transmission delay between the terminal 11 and each distributed station 14. For example, the delay measurement unit 213d measures the transmission delay between the terminal 11 and each distributed station 14 based on the RTT (Round-Trip Time) obtained as a result of sending a Ping. The delay measurement unit 213d outputs the propagation delay information measured for each distributed station 14 as collaborative information to the analysis unit 22d.

[0183] The analysis unit 22d comprises a collaboration information storage unit 221 and a real-time analysis unit 222d. Based on the collaboration information, the real-time analysis unit 222d analyzes the communication status in the mobile NW system 100d, such as the amount of change in the number of connections of the distributed station 14 per unit time. Specifically, the real-time analysis unit 222d divides the delay time by the current number of connected terminals to estimate the delay time per terminal. Furthermore, the real-time analysis unit 222d multiplies the number of connected terminals of other distributed stations 14 by the delay time per terminal of the target distributed station 14, and determines optical path switching and sleep mode if the delay time does not exceed a threshold and the number of connected terminals of that distributed station 14 is less than the number of additional terminals that the target distributed station 14 can accommodate.

[0184] Figure 28 is a flowchart showing an example of the sleep process flow executed by the management control device 20d in the fourth embodiment. In Figure 28, processes similar to those in Figure 3 are denoted by the same reference numerals as in Figure 3, and their explanation is omitted.

[0185] The delay measurement unit 213d measures the transmission delay between terminal 11 and each distributed station 14 (step S2101). The cooperation information collection unit 21d acquires cooperation information from each distributed station 14 (step S2102). Specifically, the acquisition unit 211 acquires information on at least the number of terminals accommodated and information on the maximum number of terminals accommodated, etc., as cooperation information from each distributed station 14. The cooperation information collection unit 21d stores the acquired cooperation information for each distributed station 14 in the cooperation information storage unit 221 (step S2103). Specifically, in addition to the cooperation information including information on at least the number of terminals accommodated and information on the maximum number of terminals accommodated, etc., the cooperation information collection unit 21d stores information on the transmission delay between terminal 11 and each distributed station 14 as cooperation information in the cooperation information storage unit 221.

[0186] The real-time analysis unit 222d calculates the number of additional terminals that each distributed station 14 can accommodate based on the cooperation information for each distributed station 14 stored in the cooperation information storage unit 221 (step S2104). Furthermore, the real-time analysis unit 222d estimates the delay time for each distributed station 14 based on the transmission delay information between the terminal 11 and each distributed station 14 stored in the cooperation information storage unit 221 (step S2105).

[0187] The real-time analysis unit 222d determines whether the fourth switching condition has been met (step S2106). The fourth switching condition is a condition indicating that a switch in the optical path between the radio station 12 and the distributed station 14 is necessary, for example, that the number of additional terminals that a certain distributed station 14 can accommodate is greater than the number of terminals that the distributed station 14 subject to sleep determination can accommodate, and that the transmission delay does not exceed a threshold.

[0188] If the real-time analysis unit 222d determines that the fourth switching condition is met (step S2106-YES), it executes the processes from step S105 onwards. On the other hand, if the real-time analysis unit 222d determines that the second switching condition is not met (step S2106-NO), it executes the processes from step S107 onwards.

[0189] Figure 29 is a flowchart showing an example of the sleep process flow executed by the management control device 20d in the fourth embodiment. The process shown in Figure 29 is described in more detail than the process shown in Figure 28. In Figure 29, processes similar to those in Figure 4 are denoted by the same reference numerals as in Figure 4 and their explanation is omitted.

[0190] The delay measurement unit 213d measures the transmission delay between terminal 11 and each distributed station 14 (step S2201). The acquisition unit 211 acquires information from each distributed station 14 as linked information, including the maximum number of terminals each distributed station can accommodate, connected radio station information, and the number of terminals each distributed station can accommodate (step S2202).

[0191] The acquisition unit 211 stores the acquired cooperation information for each distributed station 14 in the cooperation information storage unit 221 (step S2203). The real-time analysis unit 222d calculates the number of additional terminals that each distributed station 14 can accommodate based on the cooperation information for each distributed station 14 stored in the cooperation information storage unit 221 (step S2204). Furthermore, the real-time analysis unit 222d estimates the transmission delay per unit of each distributed station 14 based on the measured transmission delay information between the terminal 11 and each distributed station 14 (step S2205).

[0192] Specifically, the real-time analysis unit 222d processes the transmission delay value T of the distributed station 14-i obtained in step S2201. i The number of terminals connected to distributed station 14-i is u i Divide by (T i / u i ) By doing so, the transmission delay t per distributed station 14-i i Next, the real-time analysis unit 222d substitutes the value 1 for the constant i (step S2206). Next, the real-time analysis unit 222d substitutes the value (i+1) for k (step S2207).

[0193] Subsequently, the real-time analysis unit 222d U i -u i >u k , and, T>t i ×(u i +u k Determine whether or not the condition is met (step S2208). In the fourth embodiment, t i This is the transmission delay t per distributed station 14-i. i It represents U i -u i >u k , and, T>t i ×(u i +u kThe conditions indicated by ) are specific examples of the fourth switching condition. If the real-time analysis unit 222d determines that the fourth switching condition is met (step S2208-YES), it executes the processes from step S207 onwards. On the other hand, if the real-time analysis unit 222d determines that the second switching condition is not met (step S2208-NO), it executes the processes from step S209 onwards.

[0194] Figure 30 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the mobile NW system 100d in the fourth embodiment. In Figure 30, processes similar to those in Figure 5 are denoted by the same reference numerals as in Figure 5, and their explanation is omitted. In the explanation of Figure 30, distributed station 14-1 is assumed to be the destination distributed station, and distributed station 14-2 is assumed to be the source distributed station. Here, they will be referred to as destination distributed station 14-1 and source distributed station 14-2.

[0195] The coordination information collection unit 21d of the management control device 20d acquires coordination information from the switching destination distributed station 14-1 and the switching source distributed station 14-2 at predetermined intervals (steps S2301 and S2302). The coordination information acquired in steps S2301 and S2302 shall include at least information on the number of connected terminals, information on the maximum number of connected terminals, and information on the transmission delay between terminal 11 and each distributed station 14. The coordination information collection unit 21d stores the acquired coordination information in the coordination information storage unit 221.

[0196] When the real-time analysis unit 222d stores the linkage information storage unit 221, it performs optical path switching and sleep control determination (step S2303). The optical path switching and sleep control determination in step S2303 is a determination of whether or not the fourth switching condition in step S2106 has been met. Here, let's assume that the fourth switching condition in step S2106 has been met. If the fourth switching condition has been met, the real-time analysis unit 222d executes the processing from step S304 onwards.

[0197] Figure 31 is a flowchart showing an example of the sleep wake-up process performed by the management control device 20d in the fourth embodiment. In Figure 31, processes similar to those in Figure 6 are denoted by the same reference numerals as in Figure 6, and their explanation is omitted.

[0198] The delay measurement unit 213d measures the transmission delay between terminal 11 and each distributed station 14 (step S2401). The acquisition unit 211 acquires information on the number of connected terminals and the sleeping distributed stations 14-k from each distributed station 14 as linked information (step S2402). The acquisition unit 211 notifies the analysis unit 22d of the acquired information on the number of connected terminals, the sleeping distributed stations 14-k, and the transmission delay.

[0199] The real-time analysis unit 222d of the analysis unit 22d reads information from the cooperation information storage unit 221 about the maximum number of terminals that each distributed station 14 can accommodate and information about the radio station 12 that was connected to the sleeping distributed station 14-k (step S2403). Based on the cooperation information for each distributed station 14 obtained, the real-time analysis unit 222d calculates the number of additional terminals that each distributed station 14 can accommodate (step S2404).

[0200] Next, the real-time analysis unit 222d substitutes the value 1 for the constant i (step S2405). The real-time analysis unit 222d then performs the analysis. i i , or T <t i Determine whether any of the following conditions are met (step S2406). i i , or T <t i The conditions shown are specific examples of the fourth sleep wake-up condition. In the fourth sleep wake-up condition, T <t i This means that the transmission delay between terminal 11 and distributed station 14-i has exceeded the threshold. In other words, the transmission delay t per distributed station 14-i i This means that the threshold has been exceeded.

[0201] The real-time analysis unit 222d determines the fourth sleep wake-up condition (for example, U i i , or T <t​​​i If it is determined that the condition is met (step S2406-YES), it is determined that switching of the optical path and waking up the sleeping distributed station 14-k are necessary.

[0202] The real-time analysis unit 222d notifies the control unit 23 of the determination result. Subsequently, the processing from step S406 onwards is executed. Meanwhile, the real-time analysis unit 222d determines the fourth sleep release condition (for example, U i i , or T <t i If it is determined that the condition is not met (step S2406-NO), the process in step S408 is executed.

[0203] Figure 32 is a sequence diagram showing an example of a detailed flow of the sleep wake-up process performed by the mobile NW system 100d in the fourth embodiment. In Figure 32, processes similar to those in Figure 7 are denoted by the same reference numerals as in Figure 7 and their explanation is omitted. In the explanation of Figure 32, it is assumed that the distributed station 14-2 is in a sleep state.

[0204] Distributed station 14-2 is in a sleep state (step S501). The cooperation information collection unit 21d of the management control device 20d acquires cooperation information from distributed station 14-1 at predetermined intervals (step S2501). The cooperation information acquired in step S2501 includes at least information on the number of connected terminals, information on the maximum number of connected terminals, etc., as well as information on the transmission delay between terminal 11 and each distributed station 14. The cooperation information collection unit 21d stores the acquired cooperation information in the cooperation information storage unit 221.

[0205] When the real-time analysis unit 222d stores the linkage information storage unit 221, it performs optical path switching and sleep control determination (step S2502). The optical path switching and sleep control determination in step S2502 is whether or not the sleep release condition has been met. Here, let's assume that the sleep release condition has been met. If the sleep release condition has been met, the real-time analysis unit 222d executes the processing from step S504 onwards.

[0206] ​ With the mobile network system 100d configured as described above, the same effects as in the first embodiment can be obtained. Specifically, in the mobile network system 100d, the management control device 20d further acquires information on the transmission delay between the terminal 11 and each distributed station 14 as cooperation information, and determines whether or not to switch optical paths based on the cooperation information. If the management control device 20d determines that switching optical paths is necessary, it controls the switching of optical paths between one or more radio stations 12 and multiple distributed stations 14. Furthermore, after the optical path switching has been performed, the management control device 20d puts distributed stations that can enter sleep mode into sleep mode. This allows for the control of optical path switching and sleep mode while analyzing the load of each distributed station 14. Therefore, it becomes possible to efficiently achieve power saving as a whole system.

[0207] (Modification 1 in the fourth embodiment) In the embodiment described above, the management control device 20d is shown to directly acquire cooperation information from the distributed station 14. The management control device 20d may also acquire cooperation information via other devices. Here, other devices are, for example, wireless controllers. In this configuration, the mobile NW system 100d is newly equipped with a wireless controller 30a, and the wireless controller 30a is provided between the management control device 20d and the distributed station 14.

[0208] The wireless controller 30a acquires cooperation information from each distributed station 14 at predetermined intervals via wireless communication. The wireless controller 30a transmits the acquired cooperation information to the management control device 20d via wireless communication. Alternatively, the wireless controller 30a may receive a sleep control instruction from the management control device 20d and transmit it to the switching source distributed station. This configuration allows for the collection of collaborative information via wireless communication.

[0209] (Modification 2 in the fourth embodiment) In the embodiment described above, the management control device 20d is configured to perform optical path switching control processing and sleep control processing. In contrast, the switching device 13 may be configured to perform optical path switching control processing and sleep control processing. In this configuration, the switching device 13 includes a control unit 23, while the management control device 20d does not include a control unit 23. The real-time analysis unit 222d of the management control device 20d notifies the switching device 13 of the analysis results. The real-time analysis unit 222d may notify the switching device 13 of the analysis results only when optical path switching and sleep control are performed. The control unit 23 of the switching device 13 performs optical path switching control processing and sleep control processing based on the analysis results notified from the management control device 20d.

[0210] Figure 33 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the mobile NW system 100d in a modified example 2 of the fourth embodiment. In Figure 33, processes similar to those in Figure 30 are denoted by the same reference numerals as in Figure 30 and their explanation is omitted.

[0211] After the processes from step S2301 to step S2303 are executed, the real-time analysis unit 222d instructs the switching device 13b to perform optical path switching control and sleep control if the fourth switching condition is met (step S2601). The switching device 13b receives the instruction transmitted from the management control device 20d.

[0212] The optical path switching control unit 231 of the switching device 13b determines the destination of the optical path from the information contained in the received instruction (step S2602). The optical path switching control unit 231 notifies the aggregation station 15 of the optical path switching destination information (step S2603). Subsequently, the optical path switching control unit 231 instructs the radio station 12 connected to the source distributed station 14-2, the destination distributed station 14-1, and the source distributed station 14-2 to switch the optical path (step S2604). After that, the processes from steps S306 to S317 are executed.

[0213] When the optical path switching is complete, the radio station 12 sends an optical path switching completion notification to the switching device 13b (step S2605). The radio station 12 may also send the optical path switching completion notification to the management control device 20d. When the switching destination distributed station 14-1 is complete, it sends an optical path switching completion notification to the switching device 13 (step S2606). The radio station 12 may also send the optical path switching completion notification to the management control device 20d.

[0214] When the sleep control unit 232 of the switching device 13b receives an optical path switching completion notification from the destination of the optical path switching start notification, it sends a sleep permission notification to the switching source distributed station 14-2 (step S2607). When the switching source distributed station 14-2 receives the sleep permission notification from the switching device 13, it sends a sleep response notification to the switching device 13b (step S2608). After sending the sleep response notification, the switching source distributed station 14-2 enters a sleep state (step S322).

[0215] Figure 34 is a sequence diagram showing an example of a detailed flow of the sleep wake-up process performed by the mobile NW system 100d in a modified example 2 of the fourth embodiment. In Figure 34, processes similar to those in Figure 31 are denoted by the same reference numerals as in Figure 31 and their explanations are omitted. Note that in the explanation of Figure 31, it is assumed that the distributed station 14-2 is in a sleep state.

[0216] After steps S501, S2501, and S2502 are executed, the real-time analysis unit 222d instructs the switching device 13b to perform optical path switching control and sleep control if the sleep release conditions are met (step S2701). The switching device 13b receives the instruction transmitted from the management control device 20d.

[0217] The sleep control unit 232 of the switching device 13b transmits a sleep wake notification to the distributed station 14-2 based on the information contained in the received instruction (step S2702). In response to receiving the sleep wake notification, the distributed station 14-2 transmits a sleep wake response notification to the switching device 13b (step S2703).

[0218] The optical path switching control unit 231 of the switching device 13b determines the destination of the optical path from the information contained in the received instruction (step S2704). The optical path switching control unit 231 of the switching device 13b notifies the aggregation station 15 of the optical path switching destination information (step S2705). Subsequently, the processes from steps S507 to S520 are executed.

[0219] When the optical path switching is complete, the radio station 12 sends an optical path switching completion notification to the switching device 13b (step S2706). When the optical path switching is complete, the distributed station 14-1 sends an optical path switching completion notification to the switching device 13b (step S2707). When the optical path switching is complete, the distributed station 14-2 sends an optical path switching completion notification to the switching device 13b (step S2708).

[0220] (Modification 1 common to the first to fourth embodiments) The mobile NW systems 100, 100a, 100c, and 100d do not need to be equipped with a switching device 13. In this configuration, each radio station 12 and each distributed station 14 are connected in advance in a full-mesh network configuration. Furthermore, when switching optical paths, the optical path switching control unit 231 instructs the radio stations 12 and distributed stations 14 that are subject to optical path switching to switch the optical path. For example, the optical path switching control unit 231 transmits an optical path switching instruction (for example, the process in step S305 of Figure 5) to the radio stations 12 and distributed stations 14 that are subject to optical path switching, and after receiving an optical path switching response notification from the radio stations 12 and distributed stations 14, it transmits an optical path switching start notification (for example, the process in step S312 of Figure 5) to the radio stations 12 and distributed stations 14 that are subject to optical path switching.

[0221] (Modification 2 common to the first to fourth embodiments) In each embodiment, the configuration is shown in which the source distributed station transitions to a sleep state triggered by the management control devices 20, 20c, and 20d issuing a sleep instruction to the source distributed station. The source distributed station may be configured to autonomously transition to a sleep state without a sleep instruction from the management control devices 20, 20c, and 20d. In this configuration, the source distributed station autonomously transitions to a sleep state when the autonomous sleep conditions are met. The autonomous sleep conditions are the conditions for the source distributed station to autonomously transition to a sleep state, such as the absence of radio stations 12 connected to the source distributed station (the number of radio stations 12 connected to the source distributed station being 0), or the absence of traffic during a certain period of time ΔT. In this configuration, the source distributed station is equipped with a sleep control unit. The sleep control unit equipped in the source distributed station causes itself (the source distributed station) to transition to a sleep state when the autonomous sleep conditions are met. This configuration is also applicable when the switching device 13b is equipped with a control unit 23.

[0222] (Modification 3 common to the first to fourth embodiments) In addition to the number of connected terminals, the information collected by the management control devices 20, 20c, and 20d can also include the number of terminals at each distributed station 14, the number of terminals at each radio station 12, the actual traffic volume, and a value obtained by multiplying the number of connected terminals by the average throughput of one terminal.

[0223] (Modification 4 common to the first to fourth embodiments) In each embodiment shown in the first to fourth embodiments, Figures 3, 4, 5, 10, 13, 14, 15, 18, 20, 21, 22, 25, 28, 29, 30, and 33 show a configuration in which the distributed station 14 to be put to sleep (for example, the source distributed station) is put to sleep after the optical path switching is completed. Specifically, the management control devices 20, 20b, 20c, and 20d show a configuration in which the distributed station 14 to be put to sleep (for example, the source distributed station) is put to sleep after the optical path switching is completed (for example, after receiving an optical path switching completion notification).

[0224] In contrast, in Figures 3, 4, 5, 10, 13, 14, 15, 18, 20, 21, 22, 25, 28, 29, 30, and 33, the mobile NW systems 100, 100a, 100b, 100c, and 100d may be configured to perform the optical path switching after putting the distributed station 14 to be put to sleep (for example, the source distributed station) into sleep mode. In this configuration, the management and control devices 20, 20b, 20c, and 20d will perform the optical path switching after putting the distributed station 14 to be put to sleep (for example, the source distributed station) into sleep mode. Here, "after the distributed station 14 to be put to sleep (for example, the source distributed station) has been put to sleep" may mean that the management control devices 20, 20b, 20c, and 20d have received a sleep response notification from the distributed station 14 to be put to sleep (for example, the source distributed station), or that they have sent a sleep permission notification to the distributed station 14 to be put to sleep (for example, the source distributed station).

[0225] (Fifth embodiment) The first to fourth embodiments described above illustrate configurations for solving problems that arise in mobile network systems. Specifically, the first to fourth embodiments describe configurations for solving the problem that, in a mobile network system where wireless communication is performed between terminals and each base station, each base station autonomously determines whether or not to enter sleep mode, which can prevent overall optimization and limit the effectiveness of power saving. However, such problems are not limited to mobile network systems and can also occur in wired network systems where terminals are connected by wires. Therefore, the fifth embodiment describes a configuration for resolving the above problem that can also occur in wired network systems.

[0226] (Overall configuration and processing overview of the wired network system) Figure 35 is a diagram illustrating the overall configuration and processing overview of a wired network system in an embodiment. First, the overall configuration of the wired network system will be described. A wired network system is an example of a communication system. A wired network system is, for example, a PON (Passive Optical Network). In the following description, the case where the wired network system is a PON will be described, but the wired network system may have other configurations as long as the terminals are connected by wires. For example, the wired network system may have a configuration in which the terminals are connected point-to-point. The wired network system comprises one or more ONUs 42, a switching device 43, a plurality of OLTs 44, a concentrator 45, a core device 46, and a management control device 50.

[0227] The ONU 42 and the switching device 43, the switching device 43 and the OLT 44, the OLT 44 and the concentrator 45, and the concentrator 45 and the core device 46 are connected by optical fibers that transmit optical signals. The switching device 43 and the management control device 50, and the OLT 44 and the management control device 50 are connected by electrical wires or optical fibers that transmit electrical signals. The example shown in Figure 35 shows a case where there are four ONU 42s and two OLT 44s. Note that there may be multiple switching devices 43, but the following explanation will use the case of one switching device as an example.

[0228] An ONU 42 is an optical subscriber line termination device installed in a user's home that terminates optical signals. One or more terminals 41 are connected to each ONU 42 by wires such as electrical cables. Each ONU 42 communicates with the terminals 41 via wired connections. For example, each ONU 42 receives electrical signals transmitted from terminals 41 and converts the received electrical signals into optical signals. Each ONU 42 transmits the converted optical signals to an OLT 44 connected via a switching device 43. Each ONU 42 receives optical signals via the switching device 43. Each ONU 42 converts the received optical signals into electrical signals and transmits them to terminals 41. An ONU 42 is one form of a terminal exchange.

[0229] The switching device 43 is installed between the ONU 42 and the OLT 44. The switching device 43 switches the optical path according to instructions from the management control device 50. By switching the optical path, the switching device 43 switches the connection between the ONU 42 and the OLT 44.

[0230] OLT44 is an optical subscriber line terminal device installed on the electric utility side that terminates optical signals. OLT44 receives the uplink signal transmitted by ONU42 via switching device 43. OLT44 transmits the downlink signal to ONU42 via switching device 43. The uplink signal is a signal converted from a signal transmitted by terminal 41 into an optical signal, and the downlink signal is an optical signal destined for terminal 41. Each OLT44 enters a sleep state according to instructions from the management control device 50. The information acquired by the management control device 50 from OLT44 is called cooperation information. The cooperation information in the fifth to eighth embodiments shown below is information indicating the communication status between each OLT44 and terminal 41. OLT44 is one form of a communication station.

[0231] The collaboration information includes, for example, information regarding the number of terminals accommodated. In the fifth to eighth embodiments, the information regarding the number of terminals accommodated represents the number of terminals 41 that can be accommodated for each OLT44. The collaboration information includes, for example, the maximum number of terminals that can be accommodated for an OLT44. The maximum number of terminals that can be accommodated for an OLT44 is the maximum number that an OLT44 can accommodate. The collaboration information includes, for example, information about the ONU42 to which the OLT44 of the optical path is connected (hereinafter referred to as "connected ONU information"). The collaboration information includes, for example, processing load information. In the fifth to eighth embodiments, the processing load information is information regarding the processing load of the OLT44, and may be, for example, information regarding the memory usage rate of the OLT44 or information regarding the CPU usage rate. The collaboration information includes, for example, processing delay information. In the fifth to eighth embodiments, the processing delay information represents information regarding the processing delay for each OLT44. The collaboration information includes, for example, delay information. In the fifth to eighth embodiments, the delay information represents information regarding the transmission delay between terminal 41 and each OLT44.

[0232] The OLT44 comprises at least a transmitting unit, a receiving unit, and a sleep processing unit. The transmitting unit transmits coordination information to the management control unit 50 at the request of the management control unit 50 or voluntarily. The receiving unit receives an optical path switching instruction from the management control unit 50. The fact that the OLT44 receives an optical path switching instruction from the management control unit 50 indicates that the management control unit 50 has determined, based on the coordination information, that an optical path switch between the ONU42 and the OLT44 is necessary. The sleep processing unit enters a sleep state after the optical path switch based on the optical path switching instruction has been performed. Furthermore, the OLT44 includes an optical path switching processing unit for performing the optical path switching process.

[0233] The concentrator 45 aggregates the uplink signals transmitted by each OLT 44. The concentrator 45 distributes the downlink signals.

[0234] The core device 46 performs signal processing on the uplink signals aggregated by the concentrator 45. The concentrator 45 transmits the resulting signals to an external network. The core device 46 receives signals from the external network.

[0235] The core device 46 performs predetermined signal processing on signals received from an external network. The core device 46 transmits the resulting signal, obtained as a result of performing signal processing on signals received from an external network, to the concentrator 45 as a downstream signal.

[0236] The management control device 50 acquires coordination information from the OLT 44. Based on the acquired coordination information, the management control device 50 determines whether optical path switching and sleep control are necessary. If the management control device 50 determines that optical path switching and sleep control are necessary, it performs optical path switching control processing and sleep control processing. The optical path switching control processing in the fifth to eighth embodiments is the process of switching the optical path between the ONU 42 and the OLT 44. For example, the management control device 50 instructs the switching device 43 to control the switching of the optical path between the ONU 42 and the OLT 44. The sleep control processing in the fifth to eighth embodiments is the process of causing the OLT 44 to enter sleep mode or to cancel sleep mode.

[0237] Next, we will explain the overview of the wired network system's processing. The upper diagram of Figure 35 shows the connection status of the wired network system before optical path switching, and the lower diagram of Figure 35 shows the connection status of the wired network system after optical path switching. The upper diagram of Figure 35 shows an example in which ONU42-1 and 42-2 are connected to OLT44-1, and ONU42-3 and 42-4 are connected to OLT44-2.

[0238] The management control device 50 determines whether or not to perform optical path switching control processing based on the cooperation information collected from each OLT 44. The management control device 50 determines to perform optical path switching control processing if there is an OLT 44 that can transition to a sleep state. An OLT 44 that can transition to a sleep state is, for example, an OLT 44 that does not house a terminal 41.

[0239] On the other hand, the management control device 50 determines that it will not perform optical path switching control processing if there are no OLT44s that can transition to sleep state. If the management control device 50 determines that it will perform optical path switching control processing, it instructs the switching device 43 to switch the optical path. The switching device 43 switches the optical path between the ONU42 and the OLT44 according to the instruction from the management control device 50. After the optical path switching is complete, the switching device 43 notifies the management control device 50 that the optical path switching is complete.

[0240] When the management control device 50 receives notification from the switching device 43 that the optical path switching is complete, it sends a sleep permission notification to the OLT 44 that is capable of entering a sleep state. The sleep permission notification in the fifth to eighth embodiments is a signal that includes an instruction to put the OLT 44 into a sleep state. As a result, the OLT 44 that is capable of entering a sleep state enters a sleep state.

[0241] The lower diagram in Figure 35 shows an example where ONUs 42-1 to 42-4 are connected to OLT 44-1, and OLT 44-2 has entered sleep mode. In this way, in a wired network system, based on the coordination information collected from each OLT 44, terminals 41 connected to an OLT 44 that can enter sleep mode are connected to other OLT 44s, thereby putting the OLT 44 that can enter sleep mode into sleep mode. Hereafter, the OLT 44 that can enter sleep mode will be referred to as the source OLT, and the OLT 44 that becomes the new connection destination for terminals 41 connected to the source OLT will be referred to as the destination OLT. The following describes the specific configuration using the fifth to eighth embodiments as examples.

[0242] (Fifth embodiment) Figure 36 shows an example configuration of a wired network system 200 in the fifth embodiment. The wired network system 200 in the fifth embodiment includes one or more ONUs 42, a switching device 43, a plurality of OLTs 44, a concentrator 45, a core device 46, and a management control device 50. The ONUs 42, switching device 43, OLTs 44, concentrator 45, and core device 46 were explained in Figure 35, so their explanation is omitted here. The management control device 50 includes a linkage information collection unit 51, an analysis unit 52, and a control unit 53.

[0243] The linked information collection unit 51 includes an acquisition unit 511. The acquisition unit 511 collects linked information from the OLT 44 at predetermined intervals or at arbitrary timings. The arbitrary timing may be, for example, a predetermined time, or the timing when an instruction to collect linked information is input to the management control device 50 from an external source.

[0244] The analysis unit 52 comprises a collaboration information storage unit 521 and a real-time analysis unit 522. The collaboration information storage unit 521 records the collected collaboration information in a predetermined storage device. The real-time analysis unit 522 analyzes the communication status between each OLT 44 and the terminal 41, such as the amount of change in the number of OLT 44 connections per unit time, based on the collaboration information. Specifically, the real-time analysis unit 522 determines whether or not optical path switching and sleep control are necessary based on the collaboration information.

[0245] For example, the real-time analysis unit 522 determines that optical path switching and sleep control are necessary if all terminals 41 accommodated by the source OLT can be accommodated by another OLT 44. In this case, the real-time analysis unit 522 notifies the control unit 53 of information indicating the OLT 44 to which the optical path will be switched, and information indicating the OLT 44 to be put into sleep mode.

[0246] For example, the real-time analysis unit 522 determines that switching of the optical path and sleep control are necessary when the number of terminals 41 accommodated by the OLT 44 exceeds the maximum number of terminals. In this case, the real-time analysis unit 522 notifies the control unit 53 of information indicating the OLT 44 to which the optical path will be switched, and information indicating the OLT 44 to which sleep mode will be disabled.

[0247] The control unit 53 includes an optical path switching control unit 531 and a sleep control unit 532. The optical path switching control unit 531 determines the OLT 44 to which the optical path will be switched based on the analysis results of the real-time analysis unit 522, and instructs the switching device 43 to switch the optical path. For example, the optical path switching control unit 531 determines the OLT 44 to which the optical path will be switched based on information indicating the OLT 44 to which the optical path will be switched, which is notified by the real-time analysis unit 522.

[0248] The sleep control unit 532 instructs the OLT 44 to either enter or exit sleep mode based on the analysis results of the real-time analysis unit 522.

[0249] Figure 37 is a flowchart showing an example of the sleep process flow executed by the management control device 50 in the fifth embodiment. In Figure 37, the case where the cooperation information includes at least information on the number of terminals accommodated by each OLT 44 and information on the maximum number of terminals accommodated is explained as an example. The process flow in Figure 37 is executed repeatedly at a predetermined cycle.

[0250] The acquisition unit 511 acquires linkage information from each OLT 44 (step Sa101). The acquisition unit 511 stores the acquired linkage information for each OLT 44 in the linkage information storage unit 521 (step Sa102). The real-time analysis unit 522 calculates the number of additional terminals that each OLT 44 can accommodate based on the linkage information for each OLT 44 stored in the linkage information storage unit 521 (step Sa103). Here, the number of additional terminals that can be accommodated represents the number of additional terminals 41 that can be accommodated in addition to the number of terminals currently accommodated by the OLT 44. For example, the number of additional terminals that can be accommodated can be obtained by subtracting the number of currently accommodated terminals from the maximum number of accommodated terminals.

[0251] The real-time analysis unit 522 determines whether the fifth switching condition has been met (step Sa104). The fifth switching condition is a condition that indicates that a switchover of the optical path between the ONU 42 and the OLT 44 is necessary, for example, that the number of additional terminals that a certain OLT 44 can accommodate is greater than the number of terminals that the OLT 44 subject to sleep determination can accommodate.

[0252] If the real-time analysis unit 522 determines that the fifth switching condition has been met (step Sa104-YES), it notifies the control unit 53 of an optical path switching instruction and a sleep control instruction. Based on the optical path switching instruction notified by the real-time analysis unit 522, the optical path switching control unit 531 instructs the switching device 43 to switch the optical path of the ONU 42 connected to the switching source OLT (step Sa105). Specifically, the optical path switching control unit 531 instructs the optical path of the ONU 42 connected to the switching source OLT to be directed towards the switching destination OLT.

[0253] The sleep control unit 532 sends a sleep permission notification to the switching source OLT (step Sa106). For example, the sleep control unit 532 may send a sleep instruction to the switching source OLT when it receives a notification that the optical path switching is complete from the ONU 42 connected to the switching source OLT and the switching destination OLT. This allows the switching source OLT to enter a sleep state.

[0254] In step Sa104, if the real-time analysis unit 522 determines that the fifth switching condition is not met (step Sa104-NO), it determines whether there are other OLT44s (step Sa107). Other OLT44s are, for example, OLT44s that have not been compared with the OLT44 that is the target of the sleep determination. If the real-time analysis unit 522 determines that there are no other OLT44s (step Sa107-NO), it terminates the process.

[0255] On the other hand, if the real-time analysis unit 522 determines that there are other OLT44s (step Sa107-YES), it selects information on the number of additional terminals that can be accommodated by the other OLT44s (step Sa108). Using the selected information on the number of additional terminals that can be accommodated by the other OLT44s, the real-time analysis unit 522 executes the process in step Sa104 again.

[0256] Figure 38 is a flowchart showing an example of the sleep process flow executed by the management control device 50 in the fifth embodiment. The process shown in Figure 38 is described in more detail as a more specific version of the process shown in Figure 37.

[0257] The acquisition unit 511 acquires information from each OLT 44 as linked information, including the maximum number of terminals each OLT 44 can accommodate, the connected ONU information, and the number of terminals (step Sa201).

[0258] The acquisition unit 511 stores the acquired linkage information for each OLT44 in the linkage information storage unit 521 (step Sa202). The real-time analysis unit 522 calculates the number of additional terminals that each OLT44 can accommodate based on the linkage information for each OLT44 stored in the linkage information storage unit 521 (step Sa203). Next, the real-time analysis unit 522 substitutes the value of 1 for the constant i (step Sa204). In the fifth to eighth embodiments, i represents, for example, the OLT44-i that will be the switching destination. If i=1, OLT44-1 becomes the switching destination OLT. i is a value of 1≦i≦I. I is the total number of OLT44s.

[0259] Next, the real-time analysis unit 522 substitutes the value of (i+1) for k (step Sa205). In the fifth to eighth embodiments, k represents, for example, the OLT44-k that will be switched over. When k=2 (i=1), OLT44-2 becomes the OLT that will be switched over. k is a value of 2≦k≦K. K is the total number of OLT44s minus 1, i.e., K=(I-1).

[0260] Subsequently, the real-time analysis unit 522 U i -u i >u k Determine whether or not the condition is met (step Sa206). In the fifth to eighth embodiments, U i represents the maximum number of terminals that can be accommodated by the OLT44-i, and in the fifth to eighth embodiments, u i represents the number of terminals accommodated by OLT44-i, and in the fifth to eighth embodiments, u k represents the number of terminals accommodated by OLT44-k. In the fifth embodiment, U i -u i >u k The conditions shown are specific examples of the fifth switching condition. Here, as an example, let's assume that the maximum number of terminals OLT44-1 can accommodate is 1000, the number of terminals OLT44-1 can accommodate is 100, the maximum number of terminals OLT44-2 can accommodate is 800, and the number of terminals OLT44-2 can accommodate is 200.

[0261] When i=1 and k=2, it can be expressed as follows. U1 - u1 ⇒ 1000 - 100 = 900

[0262] Based on the results described above, U1-u1>u2 is 900>200, and the fifth switching condition is met. The real-time analysis unit 522 checks the fifth switching condition (for example, U i -u i >u k If it is determined that the condition is met (step Sa206-YES), the control unit 53 is notified of an instruction to switch the optical path and an instruction to control sleep.

[0263] The optical path switching control unit 531 instructs the switching device 43 to switch the optical path of the ONU 42 connected to OLT 44-k based on the optical path switching instruction notified by the real-time analysis unit 522 (step Sa207). Specifically, the optical path switching control unit 531 instructs the optical path of the ONU 42 connected to OLT 44-k (e.g., OLT 44-2) to be directed toward the destination OLT, OLT 44-i (e.g., OLT 44-1). The sleep control unit 532 sends a sleep permission notification to OLT 44-k (e.g., OLT 44-2) (step Sa208).

[0264] On the other hand, consider, as an example, the case where the maximum number of terminals OLT44-1 can accommodate is 1000, the number of terminals OLT44-1 can accommodate is 500, the maximum number of terminals OLT44-2 can accommodate is 800, and the number of terminals OLT44-2 can accommodate is 700. When i=1 and k=2, it can be expressed as follows. U1 - u1 ⇒ 1000 - 500 = 500

[0265] Based on the results described above, U1-u1>u2 becomes 500<700, and the fifth switching condition is not met. The real-time analysis unit 522 considers the fifth switching condition (for example, U i -u i >u k If it is determined that the condition is not met (step Sa206-NO), then it is determined whether k is the maximum value (step Sa209).

[0266] If the real-time analysis unit 522 determines that k is not the maximum value (step Sa209-NO), it adds 1 to the value of k (step Sa210). Then, the real-time analysis unit 522 executes the process in step Sa206 again. For example, as in the example above, if i=1, k=2 and k is not the maximum value, the real-time analysis unit 522 adds 1 to the value of k to make k=3. Then, the real-time analysis unit 522 determines whether U1-u1>u3 is satisfied.

[0267] On the other hand, if the real-time analysis unit 522 determines that k is at its maximum value (step Sa209-YES), it determines whether i is at its maximum value (step Sa211). If the real-time analysis unit 522 determines that i is at its maximum value (step Sa211-YES), it terminates the process.

[0268] On the other hand, if the real-time analysis unit 522 determines that i is not the maximum value (step Sa211-NO), it adds 1 to the value of i (step Sa212). After that, the real-time analysis unit 522 executes the process in step Sa205 again. For example, if i=1 and k=3, and k is the maximum value but i is not the maximum value, the real-time analysis unit 522 adds 1 to the value of i to make i=2.

[0269] Then, in the process of step Sa205, the real-time analysis unit 522 substitutes the value of (i+1) for k (step Sa205). In this case, i=2 and k=3. After that, in the process of step Sa206, the real-time analysis unit 522 determines whether or not U2-u2>u3 is satisfied.

[0270] Figure 39 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the wired network system 200 in the fifth embodiment. In the explanation of Figure 39, OLT44-1 is assumed to be the destination OLT and OLT44-2 is assumed to be the source OLT. Here, they will be referred to as destination OLT44-1 and source OLT44-2.

[0271] The acquisition unit 511 of the management control device 50 acquires coordination information from the switching destination OLT 44-1 and the switching source OLT 44-2 at predetermined intervals or at arbitrary timings (steps Sa301 and Sa302). The acquisition unit 511 stores the acquired coordination information in the coordination information storage unit 521. When the coordination information is stored in the coordination information storage unit 521, the real-time analysis unit 522 makes a decision on switching the optical path and sleep control (step Sa303).

[0272] The decision to switch the optical path and perform sleep control in step Sa303 is to determine whether or not the fifth switching condition in step Sa104 has been met. Here, let's assume that the fifth switching condition in step Sa104 has been met. If the fifth switching condition has been met, the real-time analysis unit 522 instructs the optical path switching control unit 531 to perform optical path switching control and instructs the sleep control unit 532 to perform sleep control.

[0273] The optical path switching control unit 531 notifies the switching device 43 and the concentrator 45 of the optical path switching destination information (step Sa304). The optical path switching destination information is information regarding the destination of the optical path. In the example shown in Figure 39, the optical path switching destination information includes information indicating the destination OLT 44-1 as the destination of the optical path. When the switching device 43 receives the optical path switching destination information from the management control device 50, it instructs the ONU 42 connected to the source OLT 44-2, the destination OLT 44-1, and the source OLT 44-2 to switch the optical path (step Sa305). For example, the switching device 43 instructs the ONU 42 connected to the source OLT 44-2 to switch the optical path to the destination OLT 44-1, instructs the destination OLT 44-1 to switch so that the optical path is connected to the ONU 42 connected to the source OLT 44-2, and instructs the source OLT 44-2 not to set an optical path.

[0274] The ONU 42 connected to the source OLT 44-2, the destination OLT 44-1, and the source OLT 44-2 prepare for the optical path switching (steps Sa306, Sa307, and Sa308). The ONU 42 connected to the source OLT 44-2, the destination OLT 44-1, and the source OLT 44-2 send an optical path switching response notification to the switching device 43 (steps Sa309, Sa310, and Sa311).

[0275] When the switching device 43 receives an optical path switching response notification from the switching source OLT 44-2, it sends an optical path switching start notification to the ONU 42 connected to the ONU 42 connected to the switching source OLT 44-2 and to the switching destination OLT 44-1 (step Sa312).

[0276] Upon receiving the optical path switching start notification, the ONU42 connected to the source OLT44-2 and the destination OLT44-1 switch their optical paths (steps Sa313 and Sa314). This process switches the optical path of the ONU42 connected to the source OLT44-2 to point towards the destination OLT44-1. In other words, the ONU42 and the destination OLT44-1 become able to communicate with each other.

[0277] The destination OLT 44-1 sends a route switching request to the core device 46 (step Sa315). The core device 46 switches the route in response to receiving the route switching request (step Sa316). Once the route switching is complete, the core device 46 sends a route switching response notification to the destination OLT 44-1 (step Sa317).

[0278] When the optical path switching is complete, ONU42 sends an optical path switching completion notification to the management control unit 50 (step Sa318). When the switching destination OLT44-1 is complete, it sends an optical path switching completion notification to the management control unit 50 (step Sa319).

[0279] When the sleep control unit 532 of the management control device 50 receives an optical path switching completion notification from the destination of the optical path switching start notification, it sends a sleep permission notification to the switching source OLT 44-2 (step Sa320). When the switching source OLT 44-2 receives the sleep permission notification from the management control device 50, it sends a sleep response notification to the management control device 50 (step Sa321). After sending the sleep response notification, the switching source OLT 44-2 enters a sleep state (step Sa322).

[0280] Figure 40 is a flowchart showing an example of the sleep wake-up process performed by the management control device 50 in the fifth embodiment. The acquisition unit 511 acquires information on the number of connected terminals and the sleeping OLT44-k from each OLT44 as linked information (step Sa401). The acquisition unit 511 notifies the analysis unit 52 of the acquired information on the number of connected terminals and the sleeping OLT44-k.

[0281] The real-time analysis unit 522 reads information from the linkage information storage unit 521 regarding the maximum number of terminals each OLT44 can accommodate and information regarding the ONU42 that was connected to the sleeping OLT44-k (step Sa402). Based on the linkage information for each OLT44 stored in the linkage information storage unit 521, the real-time analysis unit 522 calculates the number of additional terminals that each OLT44 can accommodate (step Sa403).

[0282] Next, the real-time analysis unit 522 substitutes the value 1 for the constant i (step Sa404). The real-time analysis unit 522 then performs U i i Determine whether the condition is met (Step Sa405). i i The conditions shown are specific examples of the first sleep wake-up conditions. The real-time analysis unit 522 determines the first sleep wake-up conditions (for example, U i i If it is determined that the condition is met (step Sa405-YES), it is determined that the sleeping OLT44-k needs to be woken from sleep mode and the optical path needs to be switched.

[0283] ​​​The real-time analysis unit 522 notifies the control unit 53 of the determination result. The sleep control unit 532 sends an instruction to the sleeping OLT44-k to wake it up based on the determination result (step Sa406). The optical path switching control unit 531 obtains information about the ONU42 that was connected to the OLT44-k before it went to sleep from the information obtained in step Sa402. The optical path switching control unit 531 instructs the ONU42 that was connected to the OLT44-k before it went to sleep to change its connection to the OLT44-k.

[0284] In the processing of step Sa405, the real-time analysis unit 522 determines the first sleep release condition (for example, U i i If it is determined that the condition is not met (step Sa405-NO), it is determined whether i is the maximum value (step Sa408). If the real-time analysis unit 522 determines that i is the maximum value (step Sa408-YES), it terminates the process.

[0285] On the other hand, if the real-time analysis unit 522 determines that i is not the maximum value (step Sa408-NO), it adds the value of 1 to the value of i (step Sa409). After that, the real-time analysis unit 522 executes the process in step Sa405 again.

[0286] Here, we will explain the process in Figure 40 using specific numerical values. As an example, the total number of OLT44s is 2 (I=2), the maximum number of terminals accommodated in OLT44-1 is 1000, the number of terminals accommodated in OLT44-1 is 800, the maximum number of terminals accommodated in OLT44-2 is 800, and the number of terminals accommodated in OLT44-2 is 1000.

[0287] If i=1, U1<u1は、1000> The value becomes 800, and the first sleep wake-up condition is not met. The real-time analysis unit 522 determines that the first sleep wake-up condition (for example, U i i ​​) If it is determined that the condition is not satisfied (step Sa405 - NO), it is determined whether i is the maximum value (step Sa408). Currently, since i = 1, the real - time analysis unit 522 determines that i is not the maximum value.

[0288] The real - time analysis unit 522 adds the value of 1 to the value of i to set i = 2. The real - time analysis unit 522 executes the process of step Sa405 again. When i = 2, U2 < u2 becomes 800 < 1000, and the first sleep release condition is satisfied. Then, the processes of steps Sa406 and Sa407 are executed.

[0289] FIG. 41 is a sequence diagram showing an example of the detailed flow of the sleep release process executed by the wired NW system 200 in the fifth embodiment. In the description of FIG. 41, it is assumed that the OLT44 - 2 is in the sleep state.

[0290] The OLT44 - 2 is in the sleep state (step Sa501). The acquisition unit 511 of the management control device 50 acquires the cooperation information from the OLT44 - 1 at a predetermined period or an arbitrary timing (step Sa�02). The acquisition unit �11 stores the acquired cooperation information in the cooperation information storage unit 521. When the cooperation information is stored in the cooperation information storage unit 521, the real - time analysis unit 522 performs optical path switching and sleep control determination (step Sa503). The optical path switching and sleep control determination in step Sa503 is whether the sleep release condition is satisfied. Here, it is assumed that the sleep release condition is satisfied.

[0291] The sleep control unit 532 of the management control device 50 transmits a sleep release notification to the OLT44 - 2 (step Sa504). In response to the reception of the sleep release notification, the OLT44 - 2 transmits a sleep release response notification to the management control device 50 (step Sa505).

[0292] The optical path switching control unit 531 notifies the switching device 43 and the concentrator 45 of the optical path switching destination information (step Sa506). When the switching device 43 receives the optical path switching destination information from the management control device 50, it instructs the ONU 42, OLT 44-1, and OLT 44-2 to switch the optical path (step Sa507).

[0293] ONU42, OLT44-1, and OLT44-2 prepare for optical path switching (steps Sa508, Sa509, and Sa510). Once ONU42, OLT44-1, and OLT44-2 have completed preparations for optical path switching, they send an optical path switching response notification to the switching device 43 indicating that the preparations for switching are complete (steps Sa511, Sa512, and Sa513).

[0294] When the switching device 43 receives optical path switching response notifications from the ONU 42, OLT 44-1, and OLT 44-2, it sends an optical path switching start notification to the ONU 42, OLT 44-1, and OLT 44-2 (step Sa514).

[0295] ONU42, OLT44-1, and OLT44-2 switch optical paths in response to receiving an optical path switching start notification (steps Sa515, Sa516, and Sa517). OLT44-1 sends a route switching request to the concentrator 45 (step Sa518). The concentrator 45 switches the path in response to receiving the route switching request (step Sa519). Once the route switching is complete, the concentrator 45 sends a route switching response notification to OLT44-1 (step Sa520).

[0296] When the optical path switching is complete, ONU42 sends an optical path switching completion notification to the management control unit 50 (step Sa521). When the optical path switching is complete, OLT44-1 sends an optical path switching completion notification to the management control unit 50 (step Sa522). When the optical path switching is complete, OLT44-2 sends an optical path switching completion notification to the management control unit 50 (step Sa523).

[0297] The wired network system 200 configured as described above includes one or more ONUs 42 that perform wired communication with one or more terminals 41, multiple OLTs 44 connected to the one or more ONUs 42 via a switching device 43, a cooperation information collection unit 51 that acquires cooperation information indicating the communication status between the multiple OLTs 44 and the one or more terminals 41 at predetermined intervals or at arbitrary timings, an optical path switching control unit 531 that controls the switching of optical paths between the one or more ONUs 42 and the multiple OLTs 44 when it is determined that switching of optical paths between the one or more ONUs 42 and the multiple OLTs 44 is necessary based on the cooperation information, and a sleep control unit 532 that puts OLTs 44 capable of sleeping into a sleep state after the optical path switching has been performed. This allows for optical path switching and sleep control while analyzing the load of each OLT 44. Therefore, it is possible to significantly reduce power consumption without degrading communication quality.

[0298] (Modification 1 in the fifth embodiment) In the embodiment described above, the management control device 50 is configured to directly acquire cooperation information from the OLT 44. The management control device 50 may acquire cooperation information via another device (e.g., a controller). Figure 42 shows an example configuration of a wired network system 200a in Modification 1 of the fifth embodiment. The wired network system 200a includes one or more ONUs 42, a switching device 43, a plurality of OLTs 44, a concentrator 45, a core device 46, a management control device 50, and a controller 60a. As shown in Figure 42, in the wired network system 200a, a controller 60a is provided between the management control device 50 and the OLT 44.

[0299] Controller 60a acquires coordination information from each OLT 44 at predetermined intervals or at arbitrary timings. Controller 60a transmits the acquired coordination information to the management control device 50. Controller 60a may also receive a sleep control instruction from the management control device 50 and transmit it to the switching source OLT. With this configuration, the management control device 50 can collect collaborative information via wireless communication.

[0300] (Modification 2 in the fifth embodiment) In the embodiment described above, the management control device 50 is configured to perform optical path switching control processing and sleep control processing. Alternatively, the switching device 43 may be configured to perform optical path switching control processing and sleep control processing. Figure 43 is a diagram showing an example configuration of a wired network system 200b in a modified example 2 of the fifth embodiment. The wired network system 200b comprises one or more ONUs 42, a switching device 43b, a plurality of OLTs 44, a concentrator 45, a core device 46, and a management control device 50b.

[0301] As shown in Figure 43, the switching device 43b includes a control unit 53, while the management control device 50b does not include a control unit 53. The real-time analysis unit 522 of the management control device 50b notifies the switching device 43b of the analysis results. The real-time analysis unit 522 may notify the switching device 43b of the analysis results only when optical path switching and sleep control are performed. The control unit 53 of the switching device 43b performs optical path switching control processing and sleep control processing based on the analysis results notified from the management control device 50b.

[0302] Figure 44 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the wired network system 200b in a modified example 2 of the fifth embodiment. In Figure 44, processes similar to those in Figure 39 are denoted by the same reference numerals as in Figure 39 and their explanation is omitted. In the explanation of Figure 44, OLT44-1 is assumed to be the switching destination OLT, and OLT44-2 is assumed to be the switching source OLT. Here, they will be referred to as switching destination OLT44-1 and switching source OLT44-2.

[0303] After the processes from step Sa301 to step Sa303 are executed, the real-time analysis unit 522 instructs the switching device 43b to perform optical path switching control and sleep control if the fifth switching condition is met (step Sa601). The switching device 43b receives the instruction transmitted from the management control device 50b.

[0304] The optical path switching control unit 531 of the switching device 43b determines the destination of the optical path from the information contained in the received instruction (step Sa602). The optical path switching control unit 531 notifies the concentrator 45 of the optical path switching destination information (step Sa603). Subsequently, the optical path switching control unit 531 instructs the ONU 42 connected to the source OLT 44-2, the destination OLT 44-1, and the source OLT 44-2 to switch the optical path (step Sa604). After that, the processes from step Sa306 to step Sa317 are executed.

[0305] When the optical path switching is complete, ONU42 sends an optical path switching completion notification to switching device 43b (step Sa605). ONU42 may also send the optical path switching completion notification to management control device 50b. When the switching destination OLT44-1 is complete, it sends an optical path switching completion notification to switching device 43b (step Sa606). ONU42 may also send the optical path switching completion notification to management control device 50b.

[0306] When the sleep control unit 532 of the switching device 43b receives an optical path switching completion notification from the destination of the optical path switching start notification, it sends a sleep permission notification to the switching source OLT 44-2 (step Sa607). When the switching source OLT 44-2 receives the sleep permission notification from the switching device 43b, it sends a sleep response notification to the switching device 43b (step Sa608). After sending the sleep response notification, the switching source OLT 44-2 enters a sleep state (step Sa322).

[0307] Figure 45 is a sequence diagram showing an example of a detailed flow of the sleep wake-up process performed by the wired NW system 200b in a modified example 2 of the fifth embodiment. In Figure 45, processes similar to those in Figure 41 are denoted by the same reference numerals as in Figure 41 and their explanation is omitted. In the explanation of Figure 45, it is assumed that OLT44-2 is in a sleep state.

[0308] After the processes from step Sa501 to step Sa503 are executed, the real-time analysis unit 522 instructs the switching device 43b to perform optical path switching control and sleep control if the sleep release conditions are met (step Sa701). The switching device 43b receives the instruction transmitted from the management control device 50b.

[0309] The sleep control unit 532 of the switching device 43b sends a sleep wake notification to the OLT 44-2 based on the information contained in the received instruction (step Sa702). In response to receiving the sleep wake notification, the OLT 44-2 sends a sleep wake response notification to the switching device 43b (step Sa703).

[0310] The optical path switching control unit 531 of the switching device 43b determines the destination of the optical path from the information contained in the received instruction (step Sa704). The optical path switching control unit 531 of the switching device 43b notifies the concentrator 45 of the optical path switching destination information (step Sa705). Subsequently, the processes from step Sa507 to step Sa520 are executed.

[0311] When the optical path switching is complete, ONU42 sends an optical path switching completion notification to switching device 43b (step Sa706). When the optical path switching is complete, OLT44-1 sends an optical path switching completion notification to switching device 43b (step Sa707). When the optical path switching is complete, OLT44-2 sends an optical path switching completion notification to switching device 43b (step Sa708).

[0312] (Sixth embodiment) The sixth embodiment differs from the fifth embodiment in that it further includes processing load information (for example, information on memory usage for each OLT44 or information on CPU usage) as collaborative information. In the sixth embodiment, as an example of processing load information, information on memory usage for each OLT44 will be explained.

[0313] Figure 46 shows an example configuration of a wired network system 200c in the sixth embodiment. The wired network system 200c in the sixth embodiment comprises one or more ONUs 42, a switching device 43, a plurality of OLTs 44, a concentrator 45, a core device 46, and a management control device 50c. The management control device 50c comprises a linkage information collection unit 51c, an analysis unit 52c, and a control unit 53.

[0314] The linked information collection unit 51c comprises an acquisition unit 511 and a monitoring unit 512c. The monitoring unit 512c monitors each OLT 44 and measures the memory usage rate for each OLT 44. The monitoring unit 512c outputs the memory usage rate information measured for each OLT 44 as linked information to the analysis unit 52c.

[0315] The analysis unit 52c comprises a linkage information storage unit 521 and a real-time analysis unit 522c. Based on the linkage information, the real-time analysis unit 522c analyzes the communication status in the wired NW system 200c, such as the change in the number of connections of the OLT44 per unit time. Specifically, the real-time analysis unit 522c divides the memory usage rate by the current number of connected terminals to estimate the memory usage rate per unit. Furthermore, the real-time analysis unit 522c multiplies the number of connected terminals of other OLT44s by the memory usage rate per unit of the target OLT44, and determines optical path switching and sleep mode if the memory usage rate does not exceed 100% and the number of connected terminals of that OLT44 is less than the number of additional terminals that the target OLT44 can accommodate.

[0316] Figure 47 is a flowchart showing an example of the sleep process flow executed by the management control device 50c in the sixth embodiment. In Figure 47, processes similar to those in Figure 37 are denoted by the same reference numerals as in Figure 37 and their descriptions are omitted.

[0317] The linkage information collection unit 51c acquires linkage information from each OLT 44 (step Sa801). Specifically, the acquisition unit 511 acquires information such as the number of terminals accommodated and the maximum number of terminals accommodated from each OLT 44 as linkage information. Furthermore, the monitoring unit 512c measures the memory usage rate for each OLT 44. The linkage information collection unit 51c stores the acquired linkage information for each OLT 44 in the linkage information storage unit 521 (step Sa802). Specifically, the linkage information collection unit 51c stores information such as the number of terminals accommodated and the maximum number of terminals accommodated from each OLT 44, as well as the memory usage rate for each OLT 44, as linkage information in the linkage information storage unit 521.

[0318] The real-time analysis unit 522c calculates the number of additional terminals that each OLT 44 can accommodate based on the collaboration information for each OLT 44 stored in the collaboration information storage unit 521 (step Sa803). Furthermore, the real-time analysis unit 522c estimates the memory usage rate of each OLT 44 based on the collaboration information for each OLT 44 stored in the collaboration information storage unit 521 (step Sa804).

[0319] The real-time analysis unit 522c determines whether the sixth switching condition has been met (step Sa805). The sixth switching condition is a condition that indicates that switching of the optical path between the ONU 42 and the OLT 44 is necessary, for example, that the number of additional terminals that a certain OLT 44 can accommodate is greater than the number of terminals that the OLT 44 subject to sleep determination can accommodate, and that the memory usage rate does not exceed 100%.

[0320] If the real-time analysis unit 522c determines that the sixth switching condition is met (step Sa805-YES), it executes the processes from step Sa105 onwards. On the other hand, if the real-time analysis unit 522c determines that the sixth switching condition is not met (step Sa805-NO), it executes the processes from step Sa107 onwards.

[0321] Figure 48 is a flowchart showing an example of the sleep process flow executed by the management control device 50c in the sixth embodiment. The process shown in Figure 48 is described in more detail as the process shown in Figure 47. In Figure 48, processes similar to those in Figure 38 are denoted by the same reference numerals as in Figure 38 and their explanation is omitted.

[0322] The acquisition unit 511 acquires information from each OLT 44 as linked information, including the maximum number of terminals each OLT 44 can accommodate, the connected ONU information, and the number of terminals accommodated. Furthermore, the monitoring unit 512c acquires information on the memory usage rate of each OLT 44 (step Sa901).

[0323] The acquisition unit 511 stores the acquired linkage information for each OLT44 in the linkage information storage unit 521. The monitoring unit 512c stores the acquired memory usage information for each OLT44 as linkage information (step Sa902). The real-time analysis unit 522c calculates the number of additional terminals that each OLT44 can accommodate based on the linkage information for each OLT44 stored in the linkage information storage unit 521 (step Sa903). Furthermore, the real-time analysis unit 522c estimates the memory usage rate per unit of each OLT44 based on the linkage information for each OLT44 stored in the linkage information storage unit 521 (step Sa904).

[0324] Next, the real-time analysis unit 522c substitutes the value 1 for the constant i (step Sa905). Next, the real-time analysis unit 522c substitutes the value (i+1) for k (step Sa906). After that, the real-time analysis unit 522c performs 100-M i >m i ×u k , and U i -u i >u k Determine whether or not the condition is met (step Sa907). In the sixth to eighth embodiments, M i This represents the memory usage of the OLT44-i, and in the sixth to eighth embodiments, m i This represents the memory usage rate per OLT44 unit. iThis is calculated in step Sa904. 100-M i >m i ×u k , and U i -u i >u k The conditions shown are specific examples of the sixth switching condition.

[0325] If the real-time analysis unit 522c determines that the sixth switching condition is met (step Sa907-YES), it executes the processes from step Sa207 onwards. On the other hand, if the real-time analysis unit 522c determines that the sixth switching condition is not met (step Sa907-NO), it executes the processes from step Sa209 onwards.

[0326] Here, we will explain the process in Figure 48 using specific numerical values. As an example, let's assume that the maximum number of terminals OLT44-1 can accommodate is 1000, the number of terminals OLT44-1 can accommodate is 100, the memory usage rate M1 of OLT44-1 is 20%, the maximum number of terminals OLT44-2 can accommodate is 800, the number of terminals OLT44-2 can accommodate is 200, and the memory usage rate M2 of OLT44-2 is 30%. In this case, in the process of step Sa904, the real-time analysis unit 522c calculates m1=20 / 100=0.2 and m2=30 / 200=0.15 as approximate values ​​for the memory usage rate per OLT44. m1 represents the approximate value for the memory usage rate per OLT44-1, and m2 represents the approximate value for the memory usage rate per OLT44-2.

[0327] The real-time analysis unit 522c processes step Sa907, and 100-M i >m i ×u k , and U i -u i >u k We determine whether the condition is met. If i=1 and k=2, it can be expressed as follows. ·100-M i ⇒100-20=80 ·m i ×u k ⇒ 0.2 × 200 = 40 ·U i -u i ⇒1000-100=900

[0328] Based on the results described above, 100-M i >m i ×u k , and U i -u i >u k The conditions are 180 > 40 and 900 > 200. In this case, the real-time analysis unit 522c determines that the sixth switching condition is met. Therefore, the real-time analysis unit 522c decides to switch the ONU 42 connected to OLT 44-2 to OLT 44-1 and decides to put OLT 44-2 into sleep mode. The real-time analysis unit 522c notifies the optical path switching control unit 531 of the result of its decision to switch the ONU 42 connected to OLT 44-2 to OLT 44-1 and notifies the sleep control unit 532 of its decision to put OLT 44-2 into sleep mode.

[0329] As a result, the optical path switching control unit 531 controls the switching of the optical path to connect the ONU 42 connected to OLT 44-2 to OLT 44-1, in accordance with the notification from the real-time analysis unit 522c. The sleep control unit 532 controls the sleep state to put OLT 44-2 into a sleep state, in accordance with the notification from the real-time analysis unit 522c.

[0330] Figure 49 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the wired network system 200c in the sixth embodiment. In Figure 49, processes similar to those in Figure 39 are denoted by the same reference numerals as in Figure 39 and their explanation is omitted. In the explanation of Figure 49, OLT44-1 is assumed to be the destination OLT and OLT44-2 is assumed to be the source OLT. Here, they will be referred to as destination OLT44-1 and source OLT44-2 in the explanation.

[0331] The linkage information collection unit 51c of the management control device 50c acquires linkage information from the switching destination OLT 44-1 and the switching source OLT 44-2 at predetermined intervals or at arbitrary timings (steps Sa1001 and Sa1002). The linkage information acquired in steps Sa1001 and Sa1002 shall include at least information on the number of connected terminals, information on the maximum number of connected terminals, and information on the memory usage rate for each OLT 44. The linkage information collection unit 51c stores the acquired linkage information in the linkage information storage unit 521.

[0332] When the real-time analysis unit 522c receives the information stored in the information storage unit 521, it performs a decision on switching the optical path and controlling sleep mode (step Sa1003). The decision on switching the optical path and controlling sleep mode in step Sa1003 is to determine whether the sixth switching condition in step Sa805 has been met. Let's assume that the sixth switching condition in step Sa805 has been met. If the sixth switching condition has been met, the real-time analysis unit 522c executes the processing from step Sa304 onwards.

[0333] Figure 50 is a flowchart showing an example of the sleep wake-up process performed by the management control device 50c in the sixth embodiment. In Figure 50, processes similar to those in Figure 40 are denoted by the same reference numerals as in Figure 40 and their descriptions are omitted.

[0334] The acquisition unit 511 acquires information on the number of connected terminals and the number of sleeping OLT44-k from each OLT44 as linked information. Furthermore, the monitoring unit 512c acquires information on the memory usage rate for each OLT44 as linked information (step Sa1101). The acquisition unit 511 notifies the analysis unit 52c of the acquired information on the number of connected terminals, the number of sleeping OLT44-k, and the memory usage rate.

[0335] The real-time analysis unit 522c of the analysis unit 52c reads information on the maximum number of terminals that each OLT44 can accommodate and information on the ONU42 that was connected to the sleeping OLT44-k from the linkage information storage unit 521 (step Sa1102). Based on the linkage information for each OLT44 obtained, the real-time analysis unit 522c calculates the number of additional terminals that each OLT44 can accommodate (step Sa1103).

[0336] Next, the real-time analysis unit 522c substitutes the value 1 for the constant i (step Sa1104). The real-time analysis unit 522c then performs U i i , or T1 <M i Determine whether any of the following conditions are met (Step Sa1105). i i , or T1 <M i The conditions shown are specific examples of the second sleep wake-up condition. In the second sleep wake-up condition, T1 <M i This is the memory usage of OLT44-i M i This means that the value has exceeded the threshold T1 (for example, a predetermined value such as 80%, 90%, or 100%).

[0337] The real-time analysis unit 522c determines the second sleep wake-up condition (for example, U i i , or T1 <M i If it is determined that the condition is met (step Sa1105-YES), it is determined that switching the optical path and waking the sleeping OLT44-k are necessary.

[0338] The real-time analysis unit 522c notifies the control unit 53 of the determination result. Subsequently, the processing from step Sa406 onwards is executed. Meanwhile, the real-time analysis unit 522c determines the second sleep release condition (for example, U i i , or T1 <M i If it is determined that the condition is not met (step Sa1105-NO), the process in step Sa408 is executed.

[0339] ​​​​Figure 51 is a sequence diagram showing an example of a detailed flow of the sleep wake-up process performed by the wired NW system 200c in the sixth embodiment. In Figure 51, processes similar to those in Figure 41 are denoted by the same reference numerals as in Figure 41 and their explanation is omitted. In the explanation of Figure 51, it is assumed that OLT44-2 is in a sleep state.

[0340] OLT44-2 is in sleep mode (step Sa501). The cooperation information collection unit 51c of the management control device 50c acquires cooperation information from OLT44-1 at predetermined intervals or at arbitrary timings (step Sa1201). The cooperation information acquired in step Sa1201 shall include at least information on the number of terminals accommodated, information on the maximum number of terminals accommodated, and information on the memory usage rate for each OLT44. The cooperation information collection unit 51c stores the acquired cooperation information in the cooperation information storage unit 521.

[0341] When the real-time analysis unit 522c receives the information stored in the information storage unit 521, it performs optical path switching and sleep control determination (step Sa1202). The optical path switching and sleep control determination in step Sa1202 is whether or not the sleep release condition has been met. Let's assume that the sleep release condition has been met. If the sleep release condition has been met, the real-time analysis unit 522c executes the processing from step Sa504 onwards.

[0342] The wired network system 200c in the sixth embodiment configured as described above can achieve the same effects as the fifth embodiment. Specifically, in the wired network system 200c, the management control device 50c further acquires information on the memory usage rate of each OLT44 as cooperation information and determines whether or not optical path switching is necessary based on the cooperation information. If the management control device 50c determines that optical path switching is necessary, it controls the switching of optical paths between one or more ONU42 and multiple OLT44. Furthermore, after the optical path switching has been performed, the management control device 50c puts OLT44 that are capable of going into sleep mode into sleep mode. This allows for the control of optical path switching and sleep mode while analyzing the load of each OLT44. Therefore, it becomes possible to significantly reduce power consumption without degrading communication quality.

[0343] (Modification 1 in the sixth embodiment) In the embodiment described above, the management control device 50c is configured to directly acquire cooperation information from the OLT 44. The management control device 50c may also acquire cooperation information via another device (e.g., a controller). The wired network system 200c is further equipped with a controller 60a, and the controller 60a is provided between the management control device 50c and the OLT 44.

[0344] Controller 60a acquires coordination information from each OLT 44 at predetermined intervals or at arbitrary timings. Controller 60a transmits the acquired coordination information to the management control device 50c. Controller 60a may also receive a sleep control instruction from the management control device 50c and transmit it to the switching source OLT. With this configuration, the management control device 50c can collect collaborative information via wireless communication.

[0345] (Modification 2 in the sixth embodiment) In the embodiment described above, the management control device 50c is configured to perform optical path switching control processing and sleep control processing. In contrast, the switching device 43 may be configured to perform optical path switching control processing and sleep control processing. In this configuration, the switching device 43 includes a control unit 53, while the management control device 50c does not include a control unit 53. The real-time analysis unit 522c of the management control device 50c notifies the switching device 43 of the analysis results. The real-time analysis unit 522c may notify the switching device 43 of the analysis results only when optical path switching and sleep control are performed. The control unit 53 of the switching device 43 performs optical path switching control processing and sleep control processing based on the analysis results notified by the management control device 50c.

[0346] Figure 52 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the wired NW system 200c in a modified example 2 of the sixth embodiment. In Figure 52, processes similar to those in Figure 49 are denoted by the same reference numerals as in Figure 49 and their explanation is omitted.

[0347] After the processes from step Sa1001 to step Sa1003 are executed, the real-time analysis unit 522c instructs the switching device 43b to perform optical path switching control and sleep control if the sixth switching condition is met (step Sa1301). The switching device 43b receives the instruction transmitted from the management control device 50c.

[0348] The optical path switching control unit 531 of the switching device 43b determines the destination of the optical path from the information contained in the received instruction (step Sa1302). The optical path switching control unit 531 notifies the concentrator 45 of the optical path switching destination information (step Sa1303). Subsequently, the optical path switching control unit 531 instructs the ONU 42 connected to the switching source OLT 44-2, the switching destination OLT 44-1, and the switching source OLT 44-2 to switch the optical path (step Sa1304). After that, the processes from step Sa306 to step Sa317 are executed.

[0349] When the optical path switching is complete, ONU42 sends an optical path switching completion notification to switching device 43b (step Sa1305). ONU42 may also send the optical path switching completion notification to management control device 50c. When the switching destination OLT44-1 is complete, it sends an optical path switching completion notification to switching device 43 (step Sa1306). ONU42 may also send the optical path switching completion notification to management control device 50c.

[0350] When the sleep control unit 532 of the switching device 43b receives an optical path switching completion notification from the destination of the optical path switching start notification, it sends a sleep permission notification to the switching source OLT 44-2 (step Sa1307). When the switching source OLT 44-2 receives the sleep permission notification from the switching device 43, it sends a sleep response notification to the switching device 43b (step Sa1308). After sending the sleep response notification, the switching source OLT 44-2 enters a sleep state (step Sa322).

[0351] Figure 53 is a sequence diagram showing an example of a detailed flow of the sleep wake-up process performed by the wired NW system 200c in a modified example 2 of the sixth embodiment. In Figure 53, processes similar to those in Figure 51 are denoted by the same reference numerals as in Figure 51 and their explanations are omitted. Note that in the explanation of Figure 51, it is assumed that OLT44-2 is in a sleep state.

[0352] After steps Sa501, Sa1201, and Sa1202 are executed, the real-time analysis unit 522c instructs the switching device 43b to perform optical path switching control and sleep control if the sleep release conditions are met (step Sa1401). The switching device 43b receives the instruction transmitted from the management control device 50c.

[0353] The sleep control unit 532 of the switching device 43b sends a sleep wake notification to the OLT 44-2 based on the information contained in the received instruction (step Sa1402). In response to receiving the sleep wake notification, the OLT 44-2 sends a sleep wake response notification to the switching device 43b (step Sa1403).

[0354] The optical path switching control unit 531 of the switching device 43b determines the destination of the optical path from the information contained in the received instruction (step Sa1404). The optical path switching control unit 531 of the switching device 43b notifies the concentrator 45 of the optical path switching destination information (step Sa1405). Subsequently, the processes from step Sa507 to step Sa520 are executed.

[0355] When the optical path switching is complete, ONU42 sends an optical path switching completion notification to switching device 43b (step Sa1406). When the optical path switching is complete, OLT44-1 sends an optical path switching completion notification to switching device 43b (step Sa1407). When the optical path switching is complete, OLT44-2 sends an optical path switching completion notification to switching device 43b (step Sa1408).

[0356] (Seventh Embodiment) In the seventh embodiment, the configuration differs from the sixth embodiment in that the linked information further includes processing load information (for example, information on the memory usage rate or CPU usage rate for each OLT44) and processing delay information for each OLT44. The system configuration is the same as in the sixth embodiment. In the seventh embodiment, as an example of processing load information, information on the memory usage rate for each OLT44 will be explained.

[0357] The management control device 50c determines optical path switching and sleep based on information on the number of terminals for each OLT44, information on the memory usage rate for each OLT44, and information on the processing delay for each OLT44. For example, the monitoring unit 512c monitors each OLT44 and measures the memory usage rate for each OLT44. Furthermore, the monitoring unit 512c monitors each OLT44 and collects processing delay information for each OLT44. The monitoring unit 512c outputs the memory usage information measured for each OLT44 and the processing delay information for each OLT44 as linked information to the analysis unit 52c.

[0358] Figure 54 is a flowchart showing an example of the sleep process flow executed by the management control device 50c in the seventh embodiment. In Figure 54, processes similar to those in Figure 47 are denoted by the same reference numerals as in Figure 47 and their explanation is omitted.

[0359] The linkage information collection unit 51c acquires linkage information from each OLT 44 (step Sa1501). Specifically, the acquisition unit 511 acquires at least information on the number of terminals accommodated and information on the maximum number of terminals accommodated, etc., as linkage information from each OLT 44. Furthermore, the monitoring unit 512c measures the memory usage rate for each OLT 44 and acquires processing delay information for each OLT 44. The linkage information collection unit 51c stores the acquired linkage information for each OLT 44 in the linkage information storage unit 521 (step Sa1502). Specifically, in addition to the linkage information including at least information on the number of terminals accommodated and information on the maximum number of terminals accommodated, etc., the linkage information collection unit 51c stores information on the memory usage rate for each OLT 44 and processing delay information for each OLT 44 as linkage information in the linkage information storage unit 521.

[0360] The real-time analysis unit 522c calculates the number of additional terminals that each OLT44 can accommodate based on the collaboration information for each OLT44 stored in the collaboration information storage unit 521 (step Sa1503). Furthermore, the real-time analysis unit 522c estimates the memory usage rate of each OLT44 based on the collaboration information for each OLT44 stored in the collaboration information storage unit 521 (step Sa1504).

[0361] The real-time analysis unit 522c determines whether the seventh switching condition has been met (step Sa1505). The seventh switching condition is a condition that indicates that switching of the optical path between the ONU 42 and the OLT 44 is necessary, for example, that the number of additional terminals that a certain OLT 44 can accommodate is greater than the number of terminals that the OLT 44 subject to sleep determination accommodates, that the memory usage rate does not exceed 100%, and that the processing delay of the OLT 44 subject to sleep determination does not exceed a threshold.

[0362] If the real-time analysis unit 522c determines that the seventh switching condition is met (step Sa1505-YES), it executes the processes from step Sa105 onwards. On the other hand, if the real-time analysis unit 522c determines that the seventh switching condition is not met (step Sa1505-NO), it executes the processes from step Sa107 onwards.

[0363] Figure 55 is a flowchart showing an example of the sleep process flow executed by the management control device 50c in the seventh embodiment. The process shown in Figure 55 is described in more detail than the process shown in Figure 54. In Figure 55, processes similar to those in Figure 48 are denoted by the same reference numerals as in Figure 48 and their explanation is omitted.

[0364] The acquisition unit 511 acquires information from each OLT 44 as linked information, including the maximum number of terminals each OLT 44 can accommodate, connected ONU information, and the number of terminals accommodated. Furthermore, the monitoring unit 512c acquires information on the memory usage rate and processing delay information of each OLT 44 (step Sa1601).

[0365] The acquisition unit 511 stores the acquired linkage information for each OLT44 in the linkage information storage unit 521. Furthermore, the monitoring unit 512c stores the acquired memory usage information and processing delay information for each OLT44 as linkage information (step Sa1602). The real-time analysis unit 522c calculates the number of additional terminals that each OLT44 can accommodate based on the linkage information for each OLT44 stored in the linkage information storage unit 521 (step Sa1603). Furthermore, the real-time analysis unit 522c estimates the memory usage rate per unit of each OLT44 based on the linkage information for each OLT44 stored in the linkage information storage unit 521 (step Sa1604).

[0366] Next, the real-time analysis unit 522c substitutes the value 1 for the constant i (step Sa1605). Next, the real-time analysis unit 522c substitutes the value (i+1) for k (step Sa1606). After that, the real-time analysis unit 522c performs 100-M i >m i ×u k, and U i -u i >u k , and, T>t i Determine whether the condition is met (step Sa1607). T represents a threshold, and in the seventh embodiment, t i This represents the processing delay of OLT44-i. 100-M i >m i ×u k , and U i -u i >u k , and, T>t i The conditions shown are specific examples of the seventh switching condition.

[0367] If the real-time analysis unit 522c determines that the seventh switching condition is met (step Sa1607-YES), it executes the processes from step Sa207 onwards. On the other hand, if the real-time analysis unit 522c determines that the seventh switching condition is not met (step Sa1607-NO), it executes the processes from step Sa209 onwards.

[0368] Figure 56 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the wired network system 200c in the seventh embodiment. In Figure 56, processes similar to those in Figure 49 are denoted by the same reference numerals as in Figure 49 and their explanation is omitted. In the explanation of Figure 56, OLT44-1 is assumed to be the destination OLT and OLT44-2 is assumed to be the source OLT. Here, they will be referred to as destination OLT44-1 and source OLT44-2.

[0369] The linkage information collection unit 51c of the management control device 50c acquires linkage information from the switching destination OLT 44-1 and the switching source OLT 44-2 at predetermined intervals or at arbitrary timings (steps Sa1701 and Sa1702). The linkage information acquired in steps Sa1701 and Sa1702 shall include at least information on the number of terminals accommodated, information on the maximum number of terminals accommodated, etc., as well as information on the memory usage rate for each OLT 44 and processing delay information for each OLT 44. The linkage information collection unit 51c stores the acquired linkage information in the linkage information storage unit 521.

[0370] When the real-time analysis unit 522c receives the information stored in the information storage unit 521, it performs a decision on switching the optical path and controlling sleep mode (step Sa1703). The decision on switching the optical path and controlling sleep mode in step Sa1703 is to determine whether the seventh switching condition in step Sa1505 has been met. Let's assume that the seventh switching condition in step Sa1505 has been met. If the fifth switching condition has been met, the real-time analysis unit 522c executes the processing from step Sa304 onwards.

[0371] Figure 57 is a flowchart showing an example of the sleep wake-up process performed by the management control device 50c in the seventh embodiment. In Figure 57, processes similar to those in Figure 50 are denoted by the same reference numerals as in Figure 50 and their descriptions are omitted.

[0372] The acquisition unit 511 acquires information on the number of connected terminals and the number of sleeping OLT44-k from each OLT44 as linked information. Furthermore, the monitoring unit 512c acquires information on the memory usage rate and processing delay for each OLT44 as linked information (step Sa1751). The acquisition unit 511 notifies the analysis unit 52c of the acquired information on the number of connected terminals, the number of sleeping OLT44-k, the memory usage rate, and the processing delay for each OLT44.

[0373] The real-time analysis unit 522c of the analysis unit 52c reads information from the linkage information storage unit 521 about the maximum number of terminals that each OLT 44 can accommodate and information about the ONU 42 that was connected to the sleeping OLT 44-k (step Sa1752). Based on the linkage information for each OLT 44 obtained, the real-time analysis unit 522c calculates the number of additional terminals that each OLT 44 can accommodate (step Sa1753).

[0374] Next, the real-time analysis unit 522c substitutes the value 1 for the constant i (step Sa1754). The real-time analysis unit 522c then performs U i i , or T1 <M i , or T <t i ​Determine whether any of the following conditions are met (Step Sa1755). i i , or T1 <M i , or T <t i The conditions shown are specific examples of the third sleep wake-up condition. In the third sleep wake-up condition, T <t i This means that the processing delay of OLT44-i has exceeded the threshold.

[0375] The real-time analysis unit 522c determines the third sleep release condition (for example, U i i , or T1 <M i , or T <t i If it is determined that the condition is met (step Sa1755-YES), it is determined that switching the optical path and waking the sleeping OLT44-k are necessary.

[0376] The real-time analysis unit 522c notifies the control unit 53 of the determination result. Subsequently, the processing from step Sa406 onwards is executed. Meanwhile, the real-time analysis unit 522c determines the third sleep release condition (for example, U i i , or T1 <M i , or T <t i If it is determined that the condition is not met (step Sa1755-NO), the process in step Sa408 is executed.

[0377] Figure 58 is a sequence diagram showing an example of a detailed flow of the sleep wake-up process performed by the wired NW system 200c in the seventh embodiment. In Figure 58, processes similar to those in Figure 51 are denoted by the same reference numerals as in Figure 51 and their explanations are omitted. Note that in the explanation of Figure 51, it is assumed that OLT44-2 is in a sleep state.

[0378] ​​​OLT44-2 is in sleep mode (step Sa501). The linkage information collection unit 51c of the management control device 50c acquires linkage information from OLT44-1 at predetermined intervals or at arbitrary timings (step Sa1801). The linkage information acquired in step Sa1801 includes information on the memory usage rate and processing delay information for each OLT44. The linkage information collection unit 51c stores the acquired linkage information in the linkage information storage unit 521.

[0379] When the real-time analysis unit 522c receives the information stored in the information storage unit 521, it performs optical path switching and sleep control determination (step Sa1802). The optical path switching and sleep control determination in step Sa1802 is whether or not the sleep release condition has been met. Let's assume that the sleep release condition has been met. If the sleep release condition has been met, the real-time analysis unit 522c executes the processing from step Sa504 onwards.

[0380] The wired network system 200c in the seventh embodiment, configured as described above, can achieve the same effects as the fifth embodiment. Specifically, in the wired network system 200c in the seventh embodiment, the management control device 50c further acquires information on the memory usage rate and processing delay for each OLT44 as linked information, and determines whether or not to switch optical paths based on the linked information. If the management control device 50c determines that switching optical paths is necessary, it controls the switching of optical paths between one or more ONU42s and multiple OLT44s. Furthermore, after the optical path switching has been performed, the management control device 50c puts OLT44s that are capable of going into sleep mode into sleep mode. This allows for the control of optical path switching and sleep mode while analyzing the load on each OLT44. Therefore, it becomes possible to significantly reduce power consumption without degrading communication quality.

[0381] (Modification 1 in the 7th embodiment) In the embodiment described above, the management control device 50c is shown to directly acquire cooperation information from the OLT 44. The management control device 50c may also acquire cooperation information via another device (e.g., a controller). In this configuration, the wired network system 200c is newly equipped with a controller 60a, and the controller 60a is provided between the management control device 50c and the OLT 44.

[0382] Controller 60a acquires coordination information from each OLT 44 at predetermined intervals or at arbitrary timings. Controller 60a transmits the acquired coordination information to the management control device 50c. Controller 60a may also receive a sleep control instruction from the management control device 50c and transmit it to the switching source OLT. With this configuration, the management control device 50c can collect collaborative information via wireless communication.

[0383] (Modification 2 in the 7th embodiment) In the embodiment described above, the management control device 50c is configured to perform optical path switching control processing and sleep control processing. In contrast, the switching device 43 may be configured to perform optical path switching control processing and sleep control processing. In this configuration, the switching device 43 includes a control unit 53, while the management control device 50c does not include a control unit 53. The real-time analysis unit 522c of the management control device 50c notifies the switching device 43 of the analysis results. The real-time analysis unit 522c may notify the switching device 43 of the analysis results only when optical path switching and sleep control are performed. The control unit 53 of the switching device 43 performs optical path switching control processing and sleep control processing based on the analysis results notified by the management control device 50c.

[0384] Figure 59 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the wired NW system 200c in a modified example 2 of the seventh embodiment. In Figure 59, processes similar to those in Figure 56 are denoted by the same reference numerals as in Figure 56 and their explanation is omitted.

[0385] After the processes from step Sa1701 to step Sa1703 are executed, the real-time analysis unit 522c instructs the switching device 43b to perform optical path switching control and sleep control if the seventh switching condition is met (step Sa1901). The switching device 43b receives the instruction transmitted from the management control device 50c.

[0386] The optical path switching control unit 531 of the switching device 43b determines the destination of the optical path from the information contained in the received instruction (step Sa1902). The optical path switching control unit 531 notifies the concentrator 45 of the optical path switching destination information (step Sa1903). Subsequently, the optical path switching control unit 531 instructs the ONU 42 connected to the source OLT 44-2, the destination OLT 44-1, and the source OLT 44-2 to switch the optical path (step Sa1904). After that, the processes from step Sa306 to step Sa317 are executed.

[0387] When the optical path switching is complete, ONU42 sends an optical path switching completion notification to switching device 43b (step Sa1905). ONU42 may also send the optical path switching completion notification to management control device 50c. When the switching destination OLT44-1 completes the optical path switching, it sends an optical path switching completion notification to switching device 43 (step Sa1906). ONU42 may also send the optical path switching completion notification to management control device 50c.

[0388] When the sleep control unit 532 of the switching device 43b receives an optical path switching completion notification from the destination of the optical path switching start notification, it sends a sleep permission notification to the switching source OLT 44-2 (step Sa1907). When the switching source OLT 44-2 receives the sleep permission notification from the switching device 43, it sends a sleep response notification to the switching device 43b (step Sa1908). After sending the sleep response notification, the switching source OLT 44-2 enters a sleep state (step Sa322).

[0389] Figure 60 is a sequence diagram showing an example of a detailed flow of the sleep wake-up process performed by the wired NW system 200c in a modified example 2 of the seventh embodiment. In Figure 60, processes similar to those in Figure 57 are denoted by the same reference numerals as in Figure 57 and their explanation is omitted.

[0390] After steps Sa501, Sa1801, and Sa1802 are executed, the real-time analysis unit 522c instructs the switching device 43b to perform optical path switching control and sleep control if the sleep release conditions are met (step Sa2001). The switching device 43b receives the instruction transmitted from the management control device 50c.

[0391] The sleep control unit 532 of the switching device 43b sends a sleep wake notification to the OLT 44-2 based on the information contained in the received instruction (step Sa2002). In response to receiving the sleep wake notification, the OLT 44-2 sends a sleep wake response notification to the switching device 43b (step Sa2003).

[0392] The optical path switching control unit 531 of the switching device 43b determines the destination of the optical path from the information contained in the received instruction (step Sa2004). The optical path switching control unit 531 of the switching device 43b notifies the concentrator 45 of the optical path switching destination information (step Sa2005). Subsequently, the processes from step Sa507 to step Sa520 are executed.

[0393] When the optical path switching is complete, ONU42 sends an optical path switching completion notification to switching device 43b (step Sa2006). When the optical path switching is complete, OLT44-1 sends an optical path switching completion notification to switching device 43b (step Sa2007). When the optical path switching is complete, OLT44-2 sends an optical path switching completion notification to switching device 43b (step Sa2008).

[0394] (Eighth embodiment) In the eighth embodiment, the configuration differs from the fifth embodiment in that the communication information further includes information on the transmission delay between the terminal 41 and each OLT 44.

[0395] Figure 61 shows an example configuration of a wired network system 200d in the eighth embodiment. The wired network system 200d in the eighth embodiment comprises one or more ONUs 42, a switching device 43, a plurality of OLTs 44, a concentrator 45, a core device 46, and a management control device 50d. The management control device 50d comprises a linkage information collection unit 51d, an analysis unit 52d, and a control unit 53.

[0396] The collaborative information collection unit 51d comprises an acquisition unit 511 and a delay measurement unit 513d. The delay measurement unit 513d measures the transmission delay between the terminal 41 and each OLT 44. For example, the delay measurement unit 513d measures the transmission delay between the terminal 41 and each OLT 44 based on the RTT obtained as a result of sending a Ping. The delay measurement unit 513d outputs the propagation delay information measured for each OLT 44 as collaborative information to the analysis unit 52d.

[0397] The analysis unit 52d comprises a collaboration information storage unit 521 and a real-time analysis unit 522d. Based on the collaboration information, the real-time analysis unit 522d analyzes the communication status in the wired NW system 200d, such as the change in the number of connections of the OLT44 per unit time. Specifically, the real-time analysis unit 522d divides the delay time by the current number of connected terminals to estimate the delay time per terminal. Furthermore, the real-time analysis unit 522d multiplies the number of connected terminals of other OLT44s by the delay time per terminal of the target OLT44, and determines optical path switching and sleep mode if the delay time does not exceed a threshold and the number of connected terminals of that OLT44 is less than the number of additional terminals that the target OLT44 can accommodate.

[0398] Figure 62 is a flowchart showing an example of the sleep process flow executed by the management control device 50d in the eighth embodiment. In Figure 62, processes similar to those in Figure 37 are denoted by the same reference numerals as in Figure 37 and their descriptions are omitted.

[0399] The delay measurement unit 513d measures the transmission delay between terminal 41 and each OLT 44 (step Sa2101). The cooperation information collection unit 51d acquires cooperation information from each OLT 44 (step Sa2102). Specifically, the acquisition unit 511 acquires information such as the number of terminals accommodated and the maximum number of terminals accommodated from each OLT 44 as cooperation information. The cooperation information collection unit 51d stores the acquired cooperation information for each OLT 44 in the cooperation information storage unit 521 (step Sa2103). Specifically, in addition to the cooperation information including information such as the number of terminals accommodated and the maximum number of terminals accommodated from each OLT 44, the cooperation information collection unit 51d stores information on the transmission delay between terminal 41 and each OLT 44 as cooperation information in the cooperation information storage unit 521.

[0400] The real-time analysis unit 522d calculates the number of additional terminals that each OLT 44 can accommodate based on the collaboration information for each OLT 44 stored in the collaboration information storage unit 521 (step Sa2104). Furthermore, the real-time analysis unit 522d estimates the delay time for each OLT 44 based on the transmission delay information between the terminal 41 and each OLT 44 stored in the collaboration information storage unit 521 (step Sa2105).

[0401] The real-time analysis unit 522d determines whether the eighth switching condition has been met (step Sa2106). The eighth switching condition is a condition that indicates that switching of the optical path between the ONU 42 and the OLT 44 is necessary, for example, that the number of additional terminals that a certain OLT 44 can accommodate is greater than the number of terminals that the OLT 44 subject to sleep determination can accommodate, and that the transmission delay does not exceed a threshold.

[0402] If the real-time analysis unit 522d determines that the eighth switching condition is met (step Sa2106-YES), it executes the processes from step Sa105 onwards. On the other hand, if the real-time analysis unit 522d determines that the sixth switching condition is not met (step Sa2106-NO), it executes the processes from step Sa107 onwards.

[0403] Figure 63 is a flowchart showing an example of the sleep process flow executed by the management control device 50d in the eighth embodiment. The process shown in Figure 63 is described in more detail than the process shown in Figure 62. In Figure 63, processes similar to those in Figure 38 are denoted by the same reference numerals as in Figure 38 and their explanation is omitted.

[0404] The delay measurement unit 513d measures the transmission delay between terminal 41 and each OLT 44 (step Sa2201). The acquisition unit 511 acquires information from each OLT 44 as linked information, including the maximum number of terminals each OLT 44 can accommodate, the connected ONU information, and the number of terminals accommodated (step Sa2202).

[0405] The acquisition unit 511 stores the acquired collaboration information for each OLT 44 in the collaboration information storage unit 521 (step Sa2203). The real-time analysis unit 522d calculates the number of additional terminals that each OLT 44 can accommodate based on the collaboration information for each OLT 44 stored in the collaboration information storage unit 521 (step Sa2204). Furthermore, the real-time analysis unit 522d estimates the transmission delay per unit of each OLT 44 based on the measured transmission delay information between the terminal 41 and each OLT 44 (step Sa2205).

[0406] Specifically, the real-time analysis unit 522d processes the transmission delay value t of OLT44-i obtained in step Sa2201. i The number of terminals that OLT44-i can accommodate is U i Divide by (t i / u i ) By doing so, the transmission delay per OLT44-i unit is t i Next, the real-time analysis unit 522d substitutes the value 1 for the constant i (step Sa2206). Next, the real-time analysis unit 522d substitutes the value (i+1) for k (step Sa2207).

[0407] Subsequently, the real-time analysis unit 522d U i -u i >u k , and, T>t i ×(U i+u k Determine whether or not the condition is met (step Sa2208). In the eighth embodiment, t i The transmission delay t per OLT44-i unit i It represents U i -u i >u k , and, T>t i ×(ui+u k The conditions indicated by ) are specific examples of the eighth switching condition. If the real-time analysis unit 522d determines that the eighth switching condition is met (step Sa2208-YES), it executes the processes from step Sa207 onwards. On the other hand, if the real-time analysis unit 522d determines that the sixth switching condition is not met (step Sa2208-NO), it executes the processes from step Sa209 onwards.

[0408] Figure 64 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the wired network system 200d in the eighth embodiment. In Figure 64, processes similar to those in Figure 39 are denoted by the same reference numerals as in Figure 39 and their explanation is omitted. In the explanation of Figure 64, OLT44-1 is assumed to be the destination OLT and OLT44-2 is assumed to be the source OLT. Here, they will be referred to as destination OLT44-1 and source OLT44-2.

[0409] The linkage information collection unit 51d of the management control device 50d acquires linkage information from the switching destination OLT 44-1 and the switching source OLT 44-2 at predetermined intervals or at arbitrary timings (steps Sa2301 and Sa2302). The linkage information acquired in steps Sa2301 and Sa2302 shall include at least information on the number of connected terminals, information on the maximum number of connected terminals, and information on the transmission delay between terminal 41 and each OLT 44. The linkage information collection unit 51d stores the acquired linkage information in the linkage information storage unit 521.

[0410] When the real-time analysis unit 522d receives the information stored in the information storage unit 521, it performs a decision on switching the optical path and controlling sleep mode (step Sa2303). The decision on switching the optical path and controlling sleep mode in step Sa2303 is to determine whether the eighth switching condition in step Sa2106 has been met. Let's assume that the eighth switching condition in step Sa2106 has been met. If the eighth switching condition has been met, the real-time analysis unit 522d executes the processing from step Sa304 onwards.

[0411] Figure 65 is a flowchart showing an example of the sleep wake-up process performed by the management control device 50d in the eighth embodiment. In Figure 65, processes similar to those in Figure 40 are denoted by the same reference numerals as in Figure 40 and their descriptions are omitted.

[0412] The delay measurement unit 513d measures the transmission delay between terminal 41 and each OLT 44 (step Sa2401). The acquisition unit 511 acquires information on the number of connected terminals and the sleeping OLT 44-k from each OLT 44 as linked information (step Sa2402). The acquisition unit 511 notifies the analysis unit 52d of the acquired information on the number of connected terminals, the sleeping OLT 44-k, and the transmission delay.

[0413] The real-time analysis unit 522d of the analysis unit 52d reads information on the maximum number of terminals that each OLT44 can accommodate and information on the ONU42 that was connected to the sleeping OLT44-k from the linkage information storage unit 521 (step Sa2403). Based on the linkage information for each OLT44 obtained, the real-time analysis unit 522d calculates the number of additional terminals that each OLT44 can accommodate (step Sa2404).

[0414] Next, the real-time analysis unit 522d substitutes the value 1 for the constant i (step Sa2405). The real-time analysis unit 522d then performs U i i , or T <t i Determine whether any of the following conditions are met (Step Sa2406). i i , or T <t​​i The conditions shown are specific examples of the fourth sleep wake-up condition. In the fourth sleep wake-up condition, T <t i This means that the transmission delay between terminal 41 and OLT44-i has exceeded the threshold. In other words, the transmission delay t per OLT44-i i This means that the threshold has been exceeded.

[0415] The real-time analysis unit 522d determines the fourth sleep release condition (for example, U i i , or T <t i If it is determined that the condition is met (step Sa2406-YES), it is determined that switching the optical path and waking the sleeping OLT44-k are necessary.

[0416] The real-time analysis unit 522d notifies the control unit 53 of the determination result. Subsequently, the processing from step Sa406 onwards is executed. Meanwhile, the real-time analysis unit 522d determines the fourth sleep release condition (for example, U i i , or T <t i If it is determined that the condition is not met (step Sa2406-NO), the process in step Sa408 is executed.

[0417] Figure 66 is a sequence diagram showing an example of a detailed flow of the sleep wake-up process performed by the wired NW system 200d in the eighth embodiment. In Figure 66, processes similar to those in Figure 41 are denoted by the same reference numerals as in Figure 41 and their explanation is omitted. In the explanation of Figure 66, it is assumed that OLT44-2 is in a sleep state.

[0418] ​​OLT44-2 is in sleep mode (step Sa501). The coordination information collection unit 51d of the management control device 50d acquires coordination information from OLT44-1 at predetermined intervals or at arbitrary timings (step Sa2501). The coordination information acquired in step Sa2501 shall include at least information on the number of terminals accommodated, information on the maximum number of terminals accommodated, and information on the transmission delay between terminal 41 and each OLT44. The coordination information collection unit 51d stores the acquired coordination information in the coordination information storage unit 521.

[0419] When the real-time analysis unit 522d receives the information stored in the information storage unit 521, it performs optical path switching and sleep control determination (step Sa2502). The optical path switching and sleep control determination in step Sa2502 is whether or not the sleep release condition has been met. Let's assume that the sleep release condition has been met. If the sleep release condition has been met, the real-time analysis unit 522d executes the processing from step Sa504 onwards.

[0420] With the wired network system 200d configured as described above, the same effects as in the fifth embodiment can be obtained. Specifically, in the wired network system 200d, the management control device 50d further acquires information on the transmission delay between the terminal 41 and each OLT 44 as cooperation information, and determines whether or not optical path switching is necessary based on the cooperation information. If it is determined that optical path switching is necessary, the management control device 50d controls the switching of optical paths between one or more ONUs 42 and multiple OLTs 44. Furthermore, after the optical path switching has been performed, the management control device 50d puts OLTs 44 that are capable of sleep into sleep mode. This allows for the control of optical path switching and sleep mode while analyzing the load on each OLT 44. Therefore, it becomes possible to efficiently achieve power saving for the entire system.

[0421] (Modification 1 in the 8th embodiment) In the embodiment described above, the management control device 50d is shown to directly acquire cooperation information from the OLT 44. The management control device 50d may also acquire cooperation information via another device (e.g., a controller). In this configuration, the wired network system 200d is newly equipped with a controller 60a, and the controller 60a is provided between the management control device 50d and the OLT 44.

[0422] Controller 60a acquires coordination information from each OLT 44 at predetermined intervals or at arbitrary timings. Controller 60a transmits the acquired coordination information to the management control device 50d. Controller 60a may also receive a sleep control instruction from the management control device 50d and transmit it to the switching source OLT. With this configuration, the management control device 50d can collect collaborative information via wireless communication.

[0423] (Modification 2 in the 8th embodiment) In the embodiment described above, the management control device 50d is configured to perform optical path switching control processing and sleep control processing. In contrast, the switching device 43 may be configured to perform optical path switching control processing and sleep control processing. In this configuration, the switching device 43 includes a control unit 53, while the management control device 50d does not include a control unit 53. The real-time analysis unit 522d of the management control device 50d notifies the switching device 43 of the analysis results. The real-time analysis unit 522d may notify the switching device 43 of the analysis results only when optical path switching and sleep control are performed. The control unit 53 of the switching device 43 performs optical path switching control processing and sleep control processing based on the analysis results notified by the management control device 50d.

[0424] Figure 67 is a sequence diagram showing an example of a detailed flow of the sleep process performed by the wired NW system 200d in a modified example 2 of the eighth embodiment. In Figure 67, processes similar to those in Figure 64 are denoted by the same reference numerals as in Figure 64 and their explanation is omitted.

[0425] After the processes from step Sa2301 to step Sa2303 are executed, the real-time analysis unit 522d instructs the switching device 43b to perform optical path switching control and sleep control if the eighth switching condition is met (step Sa2601). The switching device 43b receives the instruction transmitted from the management control device 50d.

[0426] The optical path switching control unit 531 of the switching device 43b determines the destination of the optical path from the information contained in the received instruction (step Sa2602). The optical path switching control unit 531 notifies the concentrator 45 of the optical path switching destination information (step Sa2603). Subsequently, the optical path switching control unit 531 instructs the ONU 42 connected to the source OLT 44-2, the destination OLT 44-1, and the source OLT 44-2 to switch the optical path (step Sa2604). After that, the processes from step Sa306 to step Sa317 are executed.

[0427] When the optical path switching is complete, ONU42 sends an optical path switching completion notification to switching device 43b (step Sa2605). ONU42 may also send the optical path switching completion notification to management control device 50d. When the switching destination OLT44-1 is complete, it sends an optical path switching completion notification to switching device 43 (step Sa2606). ONU42 may also send the optical path switching completion notification to management control device 50d.

[0428] When the sleep control unit 532 of the switching device 43b receives an optical path switching completion notification from the destination of the optical path switching start notification, it sends a sleep permission notification to the switching source OLT 44-2 (step Sa2607). When the switching source OLT 44-2 receives the sleep permission notification from the switching device 43, it sends a sleep response notification to the switching device 43b (step Sa2608). After sending the sleep response notification, the switching source OLT 44-2 enters a sleep state (step Sa322).

[0429] Figure 68 is a sequence diagram showing an example of a detailed flow of the sleep wake-up process performed by the wired NW system 200d in a modified example 2 of the eighth embodiment. In Figure 68, processes similar to those in Figure 65 are denoted by the same reference numerals as in Figure 65 and their explanations are omitted. Note that in the explanation of Figure 65, it is assumed that OLT44-2 is in a sleep state.

[0430] After steps Sa501, Sa2501, and Sa2502 are executed, the real-time analysis unit 522d instructs the switching device 43b to perform optical path switching control and sleep control if the sleep release conditions are met (step Sa2701). The switching device 43b receives the instruction transmitted from the management control device 50d.

[0431] The sleep control unit 532 of the switching device 43b sends a sleep wake notification to the OLT 44-2 based on the information contained in the received instruction (step Sa2702). In response to receiving the sleep wake notification, the OLT 44-2 sends a sleep wake response notification to the switching device 43b (step Sa2703).

[0432] The optical path switching control unit 531 of the switching device 43b determines the destination of the optical path from the information contained in the received instruction (step Sa2704). The optical path switching control unit 531 of the switching device 43b notifies the concentrator 45 of the optical path switching destination information (step Sa2705). Subsequently, the processes from step Sa507 to step Sa520 are executed.

[0433] When the optical path switching is complete, ONU42 sends an optical path switching completion notification to switching device 43b (step Sa2706). When the optical path switching is complete, OLT44-1 sends an optical path switching completion notification to switching device 43b (step Sa2707). When the optical path switching is complete, OLT44-2 sends an optical path switching completion notification to switching device 43b (step Sa2708).

[0434] (Modification 1 common to the fifth to eighth embodiments) The wired NW systems 200, 200a, 200c, and 200d do not need to be equipped with a switching device 13. In this configuration, each ONU 42 and each OLT 44 are connected in advance in a full-mesh network configuration. Furthermore, when switching optical paths, the optical path switching control unit 531 instructs the ONU 42 and OLT 44 to be switched to switch optical paths. For example, the optical path switching control unit 531 sends an optical path switching instruction (for example, the process in step Sa305 of Figure 39) to the ONU 42 and OLT 44 to be switched. Then, after receiving an optical path switching response notification from each of the ONU 42 and OLT 44 to be switched, the optical path switching control unit 531 sends an optical path switching start notification (for example, the process in step Sa312 of Figure 39) to the ONU 42 and OLT 44 to be switched.

[0435] (Modification 2 common to the fifth to eighth embodiments) In the fifth to eighth embodiments, a configuration was shown in which the source OLT transitions to a sleep state triggered by a sleep instruction issued by the management control devices 50, 50c, and 50d to the source OLT. The source OLT may be configured to autonomously transition to a sleep state without a sleep instruction from the management control devices 50, 50c, and 50d. In this configuration, the source OLT autonomously transitions to a sleep state when the autonomous sleep conditions are met. The autonomous sleep conditions in Modification 2, which is common to the fifth to eighth embodiments, are the conditions for the source OLT to autonomously transition to a sleep state, such as the absence of an ONU 42 connected to the source OLT (the number of ONU 42s connected to the source OLT is 0), or the absence of traffic during a certain period of time ΔT. In this configuration, the source OLT is equipped with a sleep control unit. The sleep control unit equipped in the source OLT causes the source OLT to transition to a sleep state when the autonomous sleep conditions are met. This configuration is also applicable when the switching device 43b is equipped with a control unit 53.

[0436] (Modification 3 common to the fifth to eighth embodiments) In addition to the number of connected terminals, the management control devices 50, 50c, and 50d can also collect information such as the number of terminals in each OLT 44, the number of terminals in each ONU 42, the actual traffic volume, and a value obtained by multiplying the number of connected terminals by the average throughput of one terminal.

[0437] (Modification 4 common to the fifth to eighth embodiments) In the embodiments shown in the fifth to eighth embodiments, Figures 37, 38, 39, 44, 47, 48, 49, 52, 54, 55, 56, 59, 62, 63, 64, and 67 show a configuration in which the OLT 44 to be put to sleep (e.g., the source OLT) is put to sleep after the optical path switching is completed. Specifically, the management control devices 50, 50b, 50c, and 50d show a configuration in which the OLT 44 to be put to sleep (e.g., the source OLT) is put to sleep after the optical path switching is completed (e.g., after receiving an optical path switching completion notification).

[0438] In contrast, as shown in Figures 37, 38, 39, 44, 47, 48, 49, 52, 54, 55, 56, 59, 62, 63, 64, and 67, the optical path switching may be performed after the OLT 44 to be put to sleep (e.g., the source OLT) is put to sleep. In this configuration, the management control devices 50, 50b, 50c, and 50d will perform the optical path switching after the OLT 44 to be put to sleep (e.g., the source OLT) is put to sleep. For example, the management control devices 50, 50b, 50c, and 50d will perform the optical path switching by sending an optical path switching start notification to the target device after the OLT 44 to be put to sleep (e.g., the source OLT) is put to sleep. Here, "after the OLT 44 to be put to sleep (e.g., the source OLT) has been put to sleep" may refer to the period after the management control devices 50, 50b, 50c, and 50d have received a sleep response notification from the OLT 44 to be put to sleep (e.g., the source OLT), or after they have sent a sleep permission notification to the OLT 44 to be put to sleep (e.g., the source OLT).

[0439] At least some or all of the functional units of the management control devices 20, 20b, 20c, 20d, 50, 50b, 50c, and 50d, or some or all of the functional units of the switching devices 13, 13b, 43, and 43b, are implemented as software by a processor such as a CPU (Central Processing Unit) executing a program stored in a storage device and a memory unit having a non-volatile recording medium (non-temporary recording medium). The program may be recorded on a computer-readable non-temporary recording medium. A computer-readable non-temporary recording medium is, for example, a portable medium such as a flexible disk, magneto-optical disk, ROM (Read Only Memory), or CD-ROM (Compact Disc Read Only Memory), or a storage device such as a hard disk built into a computer system.

[0440] At least some or all of the functional units of the management control devices 20, 20b, 20c, 20d, 50, 50b, 50c, and 50d, or some or all of the functional units of the switching devices 13, 13b, 43, and 43b, may be implemented using hardware including electronic circuits (or circuits) such as LSI (Large Scale Integrated Circuit), ASIC (Application Specific Integrated Circuit), PLD (Programmable Logic Device), or FPGA (Field Programmable Gate Array).

[0441] While embodiments of this invention have been described in detail above with reference to the drawings, the specific configuration is not limited to these embodiments and includes designs and the like that do not depart from the spirit of this invention. [Industrial applicability]

[0442] This invention can be applied to optical communication systems such as optical access systems. [Explanation of Symbols]

[0443] 11…Terminal, 12, 12-1~12-4…Radio Station, 13, 13b, 43, 43b…Switching Device, 14, 14-1~14-2…Distributed Station, 15…Aggregation Station, 16, 46…Core Device, 20, 20b, 20c, 20d, 50, 50b, 50c, 50d…Management and Control Device, 21, 21c, 21d, 51, 51c, 51d…Cooperation Information Collection Unit, 22, 52…Analysis Unit, 23, 53…Control Unit, 30a…Radio Controller, 42, 42-1~42-4…ONU, 44, 44-1~44-2…OLT, 45…Concentrator, 60a…Controller, 100, 100a, 100b, 100c, 100d…Mobile NW System 200, 200a, 200b, 200c, 200d…Wired NW system, 211, 511…Acquisition unit, 212c…Distributed station monitoring unit, 512c…Monitoring unit, 213d, 513d…Delay measurement unit, 221, 521…Cooperation information storage unit, 222, 522…Real-time analysis unit, 231, 531…Optical path switching control unit, 232, 532…Sleep control unit

Claims

1. One or more terminal exchanges that communicate with one or more terminals, Multiple communication stations connected directly or via other devices to the aforementioned one or more terminal exchange stations, A cooperation information collection unit that acquires cooperation information from the communication station indicating the communication status between the communication station and the one or more terminals, When it is determined that switching of optical paths between the one or more terminal stations and the multiple communication stations is necessary based on the aforementioned coordination information, an optical path switching control unit controls the switching of optical paths between the one or more terminal stations and the multiple communication stations. A sleep control unit that puts communication stations capable of going into sleep mode into sleep mode before or after the optical path switching has occurred, Equipped with, The aforementioned collaborative information collection unit is a communication system that acquires the collaborative information via a wireless controller that performs wireless communication with each of the multiple communication stations.

2. One or more terminal exchanges that communicate with one or more terminals, Multiple communication stations connected directly or via other devices to the aforementioned one or more terminal exchange stations, A cooperation information collection unit that acquires cooperation information from the communication station indicating the communication status between the communication station and the one or more terminals, When it is determined that switching of optical paths between the one or more terminal stations and the multiple communication stations is necessary based on the aforementioned coordination information, an optical path switching control unit controls the switching of optical paths between the one or more terminal stations and the multiple communication stations. A sleep control unit that puts communication stations capable of going into sleep mode into sleep mode before or after the optical path switching has occurred, Equipped with, The aforementioned linked information includes at least information on the number of terminals accommodated per communication station and information on the maximum number of terminals accommodated per communication station. The system further includes an analysis unit that determines, based on information on the number of terminals accommodated by each communication station and information on the maximum number of terminals accommodated by each communication station, whether switching of the optical path between the one or more terminal-accommodating stations and the multiple communication stations is necessary if all terminals accommodated by the communication station subject to sleep determination can be accommodated by other communication stations. The optical path switching control unit controls the switching of optical paths so that the terminal station connected to the communication station subject to the sleep determination is connected to the other communication station. The sleep control unit transitions the communication station subject to the sleep determination to a sleep state as a communication station capable of sleep, The aforementioned collaborative information further includes at least one of the following: processing load information relating to the processing load for each communication station, or information on transmission delays between one or more terminals and the plurality of communication stations. The analysis unit determines, based on the information on the number of terminals accommodated by each communication station, the information on the maximum number of terminals accommodated by each communication station, and the processing load information or transmission delay information, that switching of the optical path between the one or more terminal-accommodating stations and the multiple communication stations is necessary if all terminals accommodated by the communication station subject to sleep determination can be accommodated by other communication stations. Communication system.

3. A communication station connected directly or via other devices to one or more terminal exchanges that communicate with one or more terminals, and a cooperation information collection unit that acquires cooperation information from the communication station indicating the status of communication between the one or more terminals, An analysis unit that determines whether or not switching of optical paths and sleep control are necessary between the one or more terminal stations and multiple communication stations based on the aforementioned coordination information, When it is determined that switching of optical paths is necessary between the one or more terminal stations and the multiple communication stations, an optical path switching control unit controls the switching of optical paths between the one or more terminal stations and the multiple communication stations. A sleep control unit that puts communication stations capable of going into sleep mode into sleep mode before or after the optical path switching has occurred, Equipped with, The aforementioned collaborative information collection unit is a management control device that acquires the collaborative information via a wireless controller that communicates wirelessly with the communication station.

4. A communications station connected to a terminal exchange that communicates with terminals, A transmitting unit that transmits coordination information indicating the communication status with the terminal to a management control device, A receiving unit receives an optical path switching instruction indicating that the management control device has determined, based on the cooperation information, that it is necessary to switch the optical path between the terminal station and the communication station. A sleep processing unit that enters a sleep state before or after the switching of the optical path based on the optical path switching instruction, Equipped with, The transmitting unit is a communication station that transmits the cooperation information to the management control device via a wireless controller that communicates wirelessly with the device.

5. A communication station connected directly or via other devices to one or more terminal exchange stations that communicate with one or more terminals acquires cooperation information indicating the communication status between the one or more terminals via a wireless controller that communicates wirelessly with the communication station. If it is determined that switching of the optical path between the one or more terminal stations and the multiple communication stations is necessary based on the aforementioned cooperation information, the switching of the optical path between the one or more terminal stations and the multiple communication stations will be controlled. Before or after the optical path switchover, put communication stations capable of going into sleep mode into sleep mode. Control method.

6. One or more terminal exchanges that communicate with one or more terminals, Multiple communication stations connected directly or via other devices to the aforementioned one or more terminal exchange stations, A cooperation information collection unit that acquires cooperation information from the communication station indicating the communication status between the communication station and the one or more terminals, When it is determined that switching of optical paths between the one or more terminal stations and the multiple communication stations is necessary based on the aforementioned coordination information, an optical path switching control unit controls the switching of optical paths between the one or more terminal stations and the multiple communication stations. Before the optical path is switched, a sleep control unit puts communication stations that can enter sleep mode into sleep mode, A communication system equipped with [the following features].

7. One or more terminal exchanges that communicate with one or more terminals, Multiple communication stations connected directly or via other devices to the aforementioned one or more terminal exchange stations, A cooperation information collection unit acquires cooperation information from the communication station, which indicates the communication status between the communication station and the one or more terminals, and which includes any of the following: information regarding the processing load of the communication station, information regarding the processing delay of the communication station, or information regarding the transmission delay between the communication station and the one or more terminals. When it is determined that switching of optical paths between the one or more terminal stations and the multiple communication stations is necessary based on the aforementioned coordination information, an optical path switching control unit controls the switching of optical paths between the one or more terminal stations and the multiple communication stations. A sleep control unit that puts communication stations capable of going into sleep mode into sleep mode before or after the optical path switching has occurred, Equipped with, The aforementioned collaborative information collection unit is a communication system that acquires the collaborative information via a wireless controller that performs wireless communication with each of the multiple communication stations.

8. One or more terminal exchanges that communicate with one or more terminals, Multiple communication stations connected directly or via other devices to the aforementioned one or more terminal exchange stations, A cooperation information collection unit that acquires cooperation information from the communication station indicating the communication status between the communication station and the one or more terminals, Based on the aforementioned coordination information, if all terminals accommodated by one of the multiple communication stations to be put into sleep mode can be accommodated by other communication stations, an optical path switching control unit controls the switching of optical paths between the one or more terminal accommodation stations and the multiple communication stations. A sleep control unit that puts the communication station to be put into sleep mode before or after the optical path switching has occurred, Equipped with, The aforementioned collaborative information collection unit is a communication system that acquires the collaborative information via a wireless controller that performs wireless communication with each of the multiple communication stations.

9. A communication station connected directly or via other devices to one or more terminal exchanges that communicate with one or more terminals, and a cooperation information collection unit that acquires cooperation information from the communication station indicating the status of communication between the one or more terminals, An analysis unit that determines whether or not switching of optical paths and sleep control are necessary between the one or more terminal stations and multiple communication stations based on the aforementioned coordination information, When it is determined that switching of optical paths is necessary between the one or more terminal stations and the multiple communication stations, an optical path switching control unit controls the switching of optical paths between the one or more terminal stations and the multiple communication stations. Before the optical path is switched, a sleep control unit puts communication stations that can enter sleep mode into sleep mode, A control device equipped with a management control system.

10. A communication station connected directly or via other devices to one or more terminal exchanges that communicate with one or more terminals, and a cooperation information collection unit that acquires cooperation information from the communication station indicating the status of communication between the one or more terminals, which includes information regarding the processing load of the communication station, information regarding the processing delay of the communication station, or information regarding the transmission delay between the communication station and the one or more terminals. An analysis unit that determines whether or not switching of optical paths and sleep control are necessary between the one or more terminal stations and multiple communication stations based on the aforementioned coordination information, When it is determined that switching of optical paths is necessary between the one or more terminal stations and the multiple communication stations, an optical path switching control unit controls the switching of optical paths between the one or more terminal stations and the multiple communication stations. A sleep control unit that puts communication stations capable of going into sleep mode into sleep mode before or after the optical path switching has occurred, Equipped with, The aforementioned collaborative information collection unit is a management control device that acquires the collaborative information via a wireless controller that communicates wirelessly with the communication station.

11. A communication station connected directly or via other devices to one or more terminal exchanges that communicate with one or more terminals, and a cooperation information collection unit that acquires cooperation information from the communication station indicating the status of communication between the one or more terminals, An analysis unit determines, based on the aforementioned coordination information, that if all terminals accommodated by a communication station to be put into sleep mode can be accommodated by other communication stations, then switching of optical paths and sleep control between the one or more terminal-accommodating stations and multiple communication stations is necessary. When it is determined that switching of optical paths is necessary between the one or more terminal stations and the multiple communication stations, an optical path switching control unit controls the switching of optical paths between the one or more terminal stations and the multiple communication stations. A sleep control unit that puts the communication station to be put into sleep mode before or after the optical path switching has occurred, Equipped with, The aforementioned collaborative information collection unit is a management control device that acquires the collaborative information via a wireless controller that communicates wirelessly with the communication station.

12. A communications station connected to a terminal exchange that communicates with terminals, A transmitting unit that transmits coordination information indicating the communication status with the terminal to a management control device, A receiving unit receives an optical path switching instruction indicating that the management control device has determined, based on the cooperation information, that it is necessary to switch the optical path between the terminal station and the communication station. A sleep processing unit that enters a sleep state before the optical path is switched based on the optical path switching instruction, A communications station equipped with the necessary equipment.

13. A communications station connected to a terminal exchange that communicates with terminals, A transmission unit transmits to a management control device cooperation information indicating the status of communication with the terminal, which includes any of the following: information regarding the processing load of the communication station, information regarding the processing delay of the communication station, or information regarding the transmission delay between the communication station and the terminal. A receiving unit receives an optical path switching instruction indicating that the management control device has determined, based on the cooperation information, that it is necessary to switch the optical path between the terminal station and the communication station. A sleep processing unit that enters a sleep state before or after the switching of the optical path based on the optical path switching instruction, Equipped with, The transmitting unit is a communication station that transmits the cooperation information to the management control device via a wireless controller that communicates wirelessly with the device.

14. A communication station connected directly or via other devices to one or more terminal exchanges that communicate with one or more terminals acquires cooperation information from the communication station indicating the status of communication between the one or more terminals. If it is determined that switching of the optical path between the one or more terminal stations and the multiple communication stations is necessary based on the aforementioned cooperation information, the switching of the optical path between the one or more terminal stations and the multiple communication stations will be controlled. Before the optical path is switched, any communication stations that can enter sleep mode are put into sleep mode. Control method.

15. A communication station connected directly or via other devices to one or more terminal exchange stations that communicate with one or more terminals, and a communication station that communicates with one or more terminals, are provided with cooperation information indicating the status of communication between the one or more terminals, which includes information regarding the processing load of the communication station, information regarding the processing delay of the communication station, or information regarding the transmission delay between the communication station and the one or more terminals. This cooperation information is acquired via a wireless controller that communicates wirelessly with the communication station. If it is determined that switching of the optical path between the one or more terminal stations and the multiple communication stations is necessary based on the aforementioned cooperation information, the switching of the optical path between the one or more terminal stations and the multiple communication stations will be controlled. Before or after the optical path switchover, put communication stations capable of going into sleep mode into sleep mode. Control method.

16. A communication station connected directly or via other devices to one or more terminal exchange stations that communicate with one or more terminals acquires cooperation information indicating the communication status between the one or more terminals via a wireless controller that communicates wirelessly with the communication station. Based on the aforementioned coordination information, if all terminals accommodated by one of the multiple communication stations to be put into sleep mode can be accommodated by other communication stations, the switching of the optical path between the one or more terminal-accommodating stations and the multiple communication stations is controlled. Before or after the optical path switching occurs, the communication station to be put into sleep mode is put into sleep mode. Control method.

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