Control device, communication system, control method and program

Abstract

This control device comprises: a collection unit that collects, at a prescribed cycle, linkage information, which is information indicating the state of communications between a communication target terminal and a communication system comprising an allocation device that allocates wavelengths and a wireless station comprising an antenna; an analysis unit that analyzes the state of communications at the communication system on the basis of the linkage information; and an allocation control unit that, on the basis of the analysis results of the analysis unit, controls the execution of wavelength allocation by the allocation device.

Description

[Technical Field]

[0001] The present invention relates to a control device, a communication system, a control method, and a program. [Background technology]

[0002] There are technologies such as AMCC (Auxiliary Management and Control Channel) and SNMP (Simple Network Management Protocol) that detect faults and failures in network devices that make up optical communication systems, and when a fault or failure occurs, issue instructions to assign backup wavelengths or assign network devices. Such technologies acquire information when a fault or failure occurs in network devices, and then assign backup wavelengths or assign network devices. The interval for this monitoring is specified to be in minutes. [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] ITU-T Recommendation G.989.3, “40-Gigabit-capable passive optical networks (NG-PON2): Transmission convergence layer specification” (2020). [Non-patent document 2] Kyosuke Sone, Goji Nakagawa, Yoshio Hirose, and Takeshi Hoshida (Fujitsu), "Demonstration of Remote Monitoring and Control of WDM-PON Systems for 5G Mobile Fronthaul," IEICE Technical Report, pp. 5-10, Jan. 2020 [Non-patent document 3] "How do you determine the monitoring interval?", SecuAvail NEWS Vol.2, [online], [Retrieved September 21, 2021], Internet <URL: https: / / www.secuavail.com / SANEWS / vol02 / sanews05.html> [Non-patent document 4] "Systemwalker Centric Manager User's Guide: Monitoring Function Edition - UNIX (registered trademark) / Windows (registered trademark) (R) -", [online], [searched September 21, 2021], Internet <URL: https: / / software.fujitsu.com / jp / manual / manualfiles / M070125 / J2X13120 / 05Z200 / moni05 / moni0126.html> [Non-patent document 5] "A Simple Network Management Protocol (SNMP)", [online], [Retrieved September 21, 2021], Internet〈URL:https: / / datatracker.ietf.org / doc / html / rfc1098> [Non-patent document 6] "Simple Network Management Protocol (SNMP) Applications", [online], [Retrieved September 21, 2021], Internet〈URL:https: / / datatracker.ietf.org / doc / html / rfc3413> [Non-Patent Document 7] "Version 2 of the Protocol Operations for the Simple Network Management Protocol (SNMP)", [online], [Retrieved September 21, 2021], Internet <URL: https: / / datatracker.ietf.org / doc / html / rfc3416> Summary of the Invention [Problem to be solved by the invention]

[0004] However, when traffic fluctuations occur due to unexpected events such as natural disasters or train delays, AMCC and SNMP cannot obtain information about the sudden traffic fluctuations and are unable to control bandwidth through real-time wavelength reallocation, which can result in network congestion, friction, and other communication problems.

[0005] In view of the above circumstances, an object of the present invention is to provide a technique for reducing the frequency of occurrence of communication failures. [Means for solving the problem]

[0006] One aspect of the present invention is a control device comprising: a collection unit that acquires, at a predetermined period, coordination information, which is information indicating the state of communication between a communication system comprising a radio station equipped with an antenna and an allocation device that allocates wavelengths, and a terminal with which communication is to be performed; an analysis unit that analyzes the state of communication in the communication system based on the coordination information; and an allocation control unit that controls the execution of wavelength allocation by the allocation device based on the analysis results of the analysis unit.

[0007] One aspect of the present invention is a communication system comprising a radio station equipped with an antenna, an allocation device that allocates wavelengths, a collection unit that acquires coordination information, which is information indicating the state of communication between the system and a terminal with which communication is intended, at a predetermined period, an analysis unit that analyzes the state of communication in the system based on the coordination information, and an allocation control unit that controls the execution of wavelength allocation by the allocation device based on the analysis results of the analysis unit.

[0008] One aspect of the present invention is a control method having a collection step of acquiring, at a predetermined period, coordination information, which is information indicating the state of communication between a communication system including a radio station having an antenna and an allocation device that allocates wavelengths, and a terminal with which communication is to be performed; an analysis step of analyzing the state of communication in the communication system based on the coordination information; and an allocation control step of controlling the execution of wavelength allocation by the allocation device based on the analysis results of the analysis step.

[0009] One aspect of the present invention is a program for causing a computer to function as the above-described control device. [Effects of the Invention]

[0010] The present invention makes it possible to reduce the frequency of occurrence of communication failures. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an example of the configuration of a communication system according to an embodiment. [Figure 2] FIG. 2 is a diagram showing an example of the configuration of a management control device according to an embodiment. [Figure 3] 10 is a first flowchart showing an example of the flow of processing executed by a management control device in the embodiment. [Figure 4] 10 is a second flowchart showing an example of the flow of processing executed by the management control device in the embodiment. [Figure 5] 10 is a third flowchart showing an example of the flow of processing executed by the management control device in the embodiment. [Figure 6] 10 is a fourth flowchart showing an example of the flow of processing executed by the management control device in the embodiment. [Figure 7] FIG. 2 is a sequence diagram illustrating an example of a flow of processing executed by the communication system according to the embodiment. [Figure 8] FIG. 10 is a sequence diagram showing an example of a flow of processing executed by a communication system according to a modified example. [Figure 9] FIG. 10 is a diagram showing an example of the configuration of a communication system according to a third modified example. [Figure 10] FIG. 11 is a first sequence diagram showing an example of the flow of processing executed by a communication system according to a third modified example. [Figure 11] FIG. 20 is a second sequence diagram showing an example of the flow of processing executed by the communication system of the third modified example. [Figure 12] FIG. 10 is a diagram showing an example of the hardware configuration of a management control device in each embodiment and modification. [Figure 13]FIG. 10 is a diagram showing an example of the hardware configuration of an allocation device in each embodiment and modification. [Figure 14] FIG. 10 is a diagram showing an example of the hardware configuration of a remote station in each embodiment and modification; DETAILED DESCRIPTION OF THE INVENTION

[0012] (Embodiment) FIG. 1 is a diagram illustrating an example of the configuration of a communication system 100 according to an embodiment. The communication system 100 is a system that communicates using optical signals. The communication system 100 acquires a signal from a terminal 900 with which communication is to be performed. The terminal 900 is, for example, a mobile wireless terminal such as a smartphone. The communication system 100 transmits the acquired signal to an external network 910.

[0013] The communication system 100 includes M radio stations 1, M remote stations 2, a management and control device 3, M allocation devices 4, a central station 5, and a core device 6. M is an integer equal to or greater than 1. That is, the communication system 100 includes one or more radio stations 1, one or more remote stations 2, and the same number of allocation devices 4 as the number of remote stations 2. There is a one-to-one correspondence between the remote stations 2 and the allocation devices 4.

[0014] The wireless station 1 receives signals transmitted by the terminal 900 and transmits signals to the terminal 900. Therefore, the wireless station 1 is a device equipped with an antenna. The wireless station 1 is, for example, an RU (Radio Unit) in the 5G communication standard.

[0015] The distributed station 2 is connected to the radio station 1 via an optical fiber. The distributed station 2 receives an uplink signal transmitted by the radio station 1. The distributed station 2 transmits a downlink signal to the radio station 1. The uplink signal is a signal transmitted by the terminal 900, and the downlink signal is a signal propagating toward the terminal 900. Each distributed station 2 is connected to multiple radio stations 1. That is, there is a 1-to-M correspondence between the distributed station 2 and the radio station 1. The distributed station 2 is, for example, a DU (Distributed Unit) in the 5G communication standard. Information that the management control device 3 acquires from the distributed station 2 is called cooperation information. The cooperation information is information indicating the state of communication between the communication system 100 (i.e., its own system) and the terminal 900.

[0016] The cooperation information includes, for example, the average throughput of the terminals 900. The cooperation information includes, for example, the number of terminals 900 with which each wireless station 1 is communicating. The cooperation information includes, for example, registration information of the terminals 900. The registration information of the terminals 900 is information indicating a PDU session establishment request of the terminal 900. The cooperation information includes, for example, scheduling information including the traffic volume of each terminal 900. The scheduling information is information indicating the transmission timing and transmission data volume of user data allocated by the remote station 2 to each terminal 900.

[0017] The management control device 3 acquires cooperation information from the remote station 2. The management control device 3 acquires a wavelength assignment notification having content based on the acquired cooperation information. The wavelength assignment notification is information indicating what kind of wavelength assignment will be performed. More specifically, the wavelength assignment notification is information indicating what kind of wavelength assignment each allocation device 4 will perform. The wavelength assignment may be a wavelength switching process, a process of assigning newly added wavelengths, or a process of deleting some wavelengths and then reassigning the remaining wavelengths. The management control device 3 controls the operation of the allocation device 4 to execute the content of the wavelength assignment notification.

[0018] The allocation device 4 performs the allocation indicated in the wavelength allocation notification sent by the management control device 3. Therefore, the allocation device 4 is a device that allocates wavelengths under the control of the management control device 3. In other words, the management control device 3 is a device that controls the execution of wavelength allocation. When the wavelength allocation is completed, the allocation device 4 notifies the management control device 3 that the wavelength allocation process has been completed. Hereinafter, the notification indicating that the wavelength allocation process has been completed is referred to as an allocation completion notification.

[0019] The central station 5 aggregates the uplink signals transmitted from the remote stations 2. The central station 5 distributes the downlink signals. The central station 5 is, for example, a CU (Centralized Unit) in the 5G communication standard.

[0020] The core device 6 performs signal processing on the uplink signals aggregated by the aggregation station 5. The core device 6 transmits signals obtained as a result of the execution of signal processing on the uplink signals to an external network 910. The core device 6 also receives signals from the external network 910.

[0021] The core device 6 performs predetermined signal processing on a signal received from the external network 910. The core device 6 transmits a signal obtained as a result of executing the signal processing on the signal received from the external network 910 to the aggregation station 5 as a downlink signal. The signal processing is, for example, the transfer of user data in a User Plane Function (UPF) of the 5G core network.

[0022] 2 is a diagram showing an example of the configuration of the management control device 3 in the embodiment. The management control device 3 includes a collection unit 31, an analysis unit 32, and an allocation control unit 33.

[0023] The collection unit 31 includes a cooperation information receiving unit 311. The cooperation information receiving unit 311 acquires cooperation information from the remote station 2.

[0024] The analysis unit 32 includes a cooperation information accumulation unit 321, a real-time analysis unit 322, and a wavelength control determination unit 323. The cooperation information accumulation unit 321 records the acquired cooperation information in a predetermined storage device. The predetermined storage device is, for example, the storage device 302 described below. The real-time analysis unit 322 analyzes the state of communication in the communication system 100, such as the amount of change in the bandwidth and the number of connections per unit time, based on the cooperation information.

[0025] The wavelength control determination unit 323 determines whether or not to reallocate wavelengths based on the analysis results of the real-time analysis unit 322. For example, the wavelength control determination unit 323 compares the analysis results of the real-time analysis unit 322 with a predetermined threshold or the currently allocated bandwidth to determine whether or not to reallocate wavelengths. Wavelength reallocation means adding or deleting wavelengths. The assigned wavelength setting unit 331 may determine which wavelengths to add and which wavelengths are unused when allocating wavelengths, and determine which wavelengths to allocate based on the determination results.

[0026] In this way, the analysis unit 32 determines whether or not to allocate wavelengths based on the cooperation information.

[0027] When the analysis unit 32 decides to allocate wavelengths, the allocation control unit 33 decides how to allocate wavelengths. Then, the allocation control unit 33 controls the operation of the allocation device 4 so that the decided content is executed by transmitting a wavelength allocation notification. Specifically, the control of the operation of the allocation device 4 by the allocation control unit 33 is performed by the allocation control unit 33 transmitting to the allocation device 4 control information that is information indicating the operation to be executed by the allocation device 4.

[0028] The allocation control unit 33 includes an allocation wavelength setting unit 331 and a wavelength control signal generation unit 332. The allocation wavelength setting unit 331 determines the destination of a wavelength allocation notification. The destination is, for example, the allocation device 4. The allocation wavelength setting unit 331 may determine the content of wavelength allocation. For example, the allocation wavelength setting unit 331 may determine wavelengths to be added when allocating and wavelengths that are not in use, and determine the wavelengths to be allocated based on the determination result.

[0029] The wavelength control signal generator 332 generates a wavelength assignment notification and notifies a predetermined destination of the generated wavelength assignment notification. The wavelength control signal generator 332 also generates control information based on the content of the wavelength assignment notification and predetermined information indicating the operable content of the allocation device 4. The control information generated in this manner is information indicating the operation of the allocation device 4 to realize the content of the wavelength assignment notification. The wavelength control signal generator 332 transmits the generated control information to the allocation device 4.

[0030] In this way, the allocation control unit 33 determines the destination of the wavelength allocation notification by the allocation destination wavelength setting unit 331 and the wavelength control signal generation unit 332, and controls the allocation device 4 to execute the determined content. In other words, the allocation control unit 33 controls the execution of wavelength allocation by the allocation device 4 based on the analysis result of the analysis unit 32.

[0031] The content of the wavelength allocation notification is determined by the allocated wavelength setting unit 331 .

[0032] Fig. 3 is a first flowchart showing an example of the flow of processing executed by the management control device 3 in the embodiment. More specifically, Fig. 3 is a flowchart showing an example of the flow of processing executed by the management control device 3 in the case where the cooperation information indicates the average throughput of the terminals 900 and the number of active terminals 900 per cell. The flow of processing in Fig. 3 is not executed only when an unexpected event occurs, such as AMCC (Auxiliary Management and Control Channel) or SNMP (Simple Network Management Protocol), but is executed repeatedly at a predetermined cycle.

[0033] The number of active terminals 900 per cell is the number of terminals 900 with which each wireless station 1 is communicating for each wireless station 1. Hereinafter, the average throughput of the terminals 900 is referred to as the average terminal throughput. Hereinafter, the number of active terminals 900 per cell is referred to as the number of active terminals.

[0034] The cooperation information receiving unit 311 acquires cooperation information from the remote station 2 (step S101). Next, the real-time analyzing unit 322 adds up the number of active terminals 900 in all cells for each unit time based on the number of active terminals included in the acquired cooperation information (step S102). Note that adding up the number of active terminals 900 in all cells for each unit time means acquiring the number of terminals 900 with which each remote station 2 is communicating for each unit time. Hereinafter, the number of terminals 900 with which each remote station 2 is communicating for each unit time is referred to as the total number of active terminals.

[0035] Next, the real-time analysis unit 322 calculates a bandwidth that satisfies a predetermined condition regarding the low frequency of occurrence of communication failures (hereinafter referred to as the "failure frequency occurrence condition") based on the terminal average throughput and the total number of active terminals (step S103). The failure frequency occurrence condition is, for example, a condition that the frequency of occurrence of communication failures is lower than a predetermined frequency. The predetermined frequency is, for example, a condition that the frequency of occurrence per unit time is one or less.

[0036] The real-time analysis unit 322 calculates, for example, the product of the terminal average throughput and the total number of active terminals, and acquires the calculation result as the bandwidth that satisfies the failure frequency occurrence condition. The processing of steps S102 and S103 is an example of analysis of the communication state in the communication system 100 by the real-time analysis unit 322 based on the cooperation information.

[0037] Next, the wavelength control determination unit 323 determines whether the bandwidth that satisfies the fault frequency occurrence condition is wider than the currently allocated bandwidth (step S104). The current bandwidth refers to the bandwidth in use. If the bandwidth that satisfies the fault frequency occurrence condition is wider than the currently allocated bandwidth (step S104: YES), the allocation control unit 33 transmits a wavelength allocation notification (step S105).

[0038] Next, the allocation device 4 executes the contents of the wavelength allocation notification (step S106). On the other hand, if the width of the bandwidth that satisfies the fault frequency occurrence condition is equal to or less than the width of the currently allocated bandwidth (step S104: NO), the allocation control unit 33 does not send a wavelength allocation notification (step S107). If a wavelength allocation notification is not sent, the allocation device 4 does not reallocate wavelengths. In this way, the allocation control unit 33 controls the operation of the allocation device 4 depending on whether or not to send a wavelength allocation notification and the contents of the wavelength allocation notification.

[0039] In this way, the wavelength assignment notification is transmitted or not transmitted depending on the result of the determination in step S104, and therefore the process in step S104 is a process for determining whether or not to reassign wavelengths. The wavelength assignment notification in the process in step S105 may be a notification of wavelength assignment including addition and deletion of wavelengths.

[0040] The content of the wavelength assignment notification is determined by the assigned wavelength setting unit 331. The content of the wavelength assignment notification is determined by the assigned wavelength setting unit 331 based on the bandwidth information calculated by the real-time analysis unit 322 after step S105. For example, the assigned wavelength setting unit 331 determines the wavelength with the fewest active terminals as the reallocation destination. The assigned wavelength setting unit 331 determines the allocation device 4 to which the wavelength assignment notification is to be sent.

[0041] Fig. 4 is a second flowchart showing an example of the flow of processing executed by the management control device 3 in the embodiment. More specifically, Fig. 4 is a flowchart showing an example of the flow of processing executed by the management control device 3 in an example where the cooperation information is the average throughput of the terminal 900 (i.e., the terminal average throughput) and the registration information of the terminal 900.

[0042] The processing flow in Figure 4 is not executed only when an unexpected event occurs, such as AMCC or SNMP, but is executed repeatedly at a predetermined interval.

[0043] The cooperation information receiving unit 311 acquires cooperation information from the remote station 2 (step S201). Next, the real-time analyzing unit 322 calculates the number of terminals 900 per unit time based on the registration information of the terminals 900 included in the cooperation information (step S202). Next, the real-time analyzing unit 322 calculates a bandwidth that satisfies the failure frequency occurrence condition based on the terminal average throughput and the number of terminals 900 per unit time (step S203).

[0044] The real-time analysis unit 322 calculates, for example, the product of the terminal average throughput and the number of terminals 900 per unit time, and acquires the calculation result as the bandwidth that satisfies the failure frequency occurrence condition. The processing of steps S202 and S203 is an example of analysis of the communication state in the communication system 100 by the real-time analysis unit 322 based on the coordination information.

[0045] Next, the wavelength control determination unit 323 determines whether the bandwidth that satisfies the fault frequency occurrence condition is wider than the currently allocated bandwidth (step S204). If the bandwidth that satisfies the fault frequency occurrence condition is wider than the currently allocated bandwidth (step S204: YES), the allocation control unit 33 transmits a wavelength allocation notification (step S205).

[0046] Next, the allocation device 4 executes the contents of the wavelength allocation notification (step S206). On the other hand, if the width of the bandwidth that satisfies the fault frequency occurrence condition is equal to or less than the width of the currently allocated bandwidth (step S204: NO), the allocation control unit 33 does not send a wavelength allocation notification (step S207). If a wavelength allocation notification is not sent, the allocation device 4 does not reallocate wavelengths. In this way, the allocation control unit 33 controls the operation of the allocation device 4 depending on whether or not to send a wavelength allocation notification and the contents of the wavelength allocation notification.

[0047] In this way, the wavelength assignment notification is transmitted or not transmitted depending on the result of the determination in step S204, and therefore the process in step S204 is a process for determining whether or not to reassign wavelengths. The wavelength assignment notification in the process in step S205 may be a notification of wavelength assignment including addition and deletion of wavelengths.

[0048] The content of the wavelength assignment notification is determined, for example, by the wavelength control determination unit 323 of the analysis unit 32. The content of the wavelength assignment notification may also be determined by the assigned wavelength setting unit 331. The content of the wavelength assignment notification is determined by the assigned wavelength setting unit 331 based on the bandwidth information calculated by the real-time analysis unit 322 after step S205. For example, the assigned wavelength setting unit 331 determines the wavelength with the fewest number of terminals per unit time as the wavelength to be reallocated. The assigned wavelength setting unit 331 determines the allocation device 4 to which the wavelength assignment notification is to be sent.

[0049] Fig. 5 is a third flowchart showing an example of the flow of processing executed by the management control device 3 in an embodiment. More specifically, Fig. 5 is a flowchart showing an example of the flow of processing executed by the management control device 3 in an example where the cooperation information is scheduling information.

[0050] The processing flow in FIG. 5 is not executed only when an unexpected event occurs, such as AMCC or SNMP, but is executed repeatedly at a predetermined interval.

[0051] The cooperation information receiving unit 311 acquires cooperation information from the remote station 2 (step S301). Next, the real-time analyzing unit 322 adds up the traffic volume of each terminal 900 included in the cooperation information for all terminals 900 (step S302). That is, in step S302, the real-time analyzing unit 322 adds up the transmission data volume of each scheduling information and acquires the calculation result as a bandwidth that satisfies the failure frequency occurrence condition.

[0052] The process of step S302 is an example of analysis of the state of communication in the communication system 100 by the real-time analysis unit 322 based on the association information.

[0053] Next, the wavelength control determination unit 323 determines whether the bandwidth that satisfies the fault frequency occurrence condition is wider than the currently allocated bandwidth (step S303). If the bandwidth that satisfies the fault frequency occurrence condition is wider than the currently allocated bandwidth (step S303: YES), the allocation control unit 33 transmits a wavelength allocation notification (step S304).

[0054] Next, the allocation device 4 executes the contents of the wavelength allocation notification (step S305). On the other hand, if the width of the bandwidth that satisfies the fault frequency occurrence condition is equal to or less than the width of the currently allocated bandwidth (step S303: NO), the allocation control unit 33 does not send a wavelength allocation notification (step S306). If a wavelength allocation notification is not sent, the allocation device 4 does not reallocate wavelengths. In this way, the allocation control unit 33 controls the operation of the allocation device 4 depending on whether or not to send a wavelength allocation notification and the contents of the wavelength allocation notification.

[0055] In this way, since the wavelength assignment notification is transmitted or not transmitted depending on the result of the determination in step S303, the process in step S303 is a process for determining whether or not to reassign wavelengths. Note that the wavelength assignment notification in the process in step S304 may be a notification of wavelength assignment including addition and deletion of wavelengths.

[0056] The content of the wavelength assignment notification is determined, for example, by the wavelength control determination unit 323 of the analysis unit 32. The content of the wavelength assignment notification may also be determined by the assigned wavelength setting unit 331. The content of the wavelength assignment notification is determined by the assigned wavelength setting unit 331 based on the bandwidth information calculated by the real-time analysis unit 322 after step S304. For example, the assigned wavelength setting unit 331 determines that the wavelength to be reallocated is one whose current bandwidth is greater than the required bandwidth. The assigned wavelength setting unit 331 determines the allocation device 4 to which the wavelength assignment notification is to be sent.

[0057] Fig. 6 is a fourth flowchart showing an example of the flow of processing executed by the management control device 3 in an embodiment. More specifically, Fig. 6 is a flowchart showing an example of the flow of processing executed by the management control device 3 in an example where one piece of cooperation information is registration information of the terminal 900.

[0058] The processing flow in FIG. 6 is not executed only when an unexpected event occurs, such as AMCC or SNMP, but is executed repeatedly at a predetermined interval.

[0059] The cooperation information receiver 311 acquires registration information of the terminals 900 from the remote station 2 (step S401). Next, the real-time analyzer 322 calculates an increase or decrease in the number of terminals 900 per unit time based on the registration information of the terminals 900 (step S402). Next, the wavelength control determiner 323 determines whether the magnitude of the increase or decrease obtained in step S402 is equal to or greater than a predetermined threshold value (step S403).

[0060] If the magnitude of the increase or decrease is not equal to or greater than the threshold (step S403: NO), the process ends. On the other hand, if the magnitude of the increase or decrease is equal to or greater than the threshold (step S403: YES), the cooperation information receiver 311 acquires the average throughput of the terminals 900 (i.e., the terminal average throughput) from the remote station 2 (step S404). Next, the real-time analyzer 322 calculates a bandwidth that satisfies the failure frequency occurrence condition based on the terminal average throughput and the number of terminals 900 per unit time (step S405).

[0061] The real-time analysis unit 322 calculates, for example, the product of the terminal average throughput and the number of terminals 900 per unit time, and acquires the calculation result as the bandwidth that satisfies the failure frequency occurrence condition. The processing of steps S402 and S405 is an example of analysis of the communication state in the communication system 100 by the real-time analysis unit 322 based on the cooperation information.

[0062] Next, the allocation control unit 33 transmits a wavelength allocation notification (step S406). Next, the allocation device 4 executes the content of the wavelength allocation notification (step S407).

[0063] 6, if it is not determined in step S403 that the magnitude of the increase or decrease is equal to or greater than the threshold, the wavelength allocation notification is not transmitted. That is, if it is not determined in step S403 that the magnitude of the increase or decrease is equal to or greater than the threshold, the allocation control unit 33 does not transmit the wavelength allocation notification. In this way, the allocation control unit 33 controls the operation of the allocation device 4 depending on whether or not to transmit a wavelength allocation notification and the content of the wavelength allocation notification.

[0064] In this way, since the wavelength assignment notification is transmitted or not transmitted depending on the result of the determination in step S403, the process in step S403 is a process for determining whether or not to reassign wavelengths. Note that the wavelength assignment notification in the process in step S406 may be a notification of wavelength assignment including addition and deletion of wavelengths.

[0065] The content of the wavelength assignment notification is determined, for example, by the wavelength control determination unit 323 of the analysis unit 32. The content of the wavelength assignment notification may also be determined by the assigned wavelength setting unit 331. The content of the wavelength assignment notification is determined by the assigned wavelength setting unit 331 based on the bandwidth information calculated by the real-time analysis unit 322 after step S406. For example, the assigned wavelength setting unit 331 determines the wavelength that has experienced a large decrease in the number of terminals per unit time as the wavelength to be reallocated. The assigned wavelength setting unit 331 determines the allocation device 4 to which the wavelength assignment notification is to be sent.

[0066] 3 to 6, the wavelength control determination unit 323 determines whether or not to execute wavelength allocation based on the cooperation information. More specifically, the wavelength control determination unit 323 determines whether or not to execute wavelength allocation based on the analysis of the communication state in the communication system 100 by the real-time analysis unit 322, which is based on the cooperation information. Then, as shown in FIGS. 3 to 6, the allocation control unit 33 controls the execution of wavelength allocation by the allocation device 4 based on whether or not to send a wavelength allocation notification and the content of the wavelength allocation notification.

[0067] Fig. 7 is a sequence diagram showing an example of the flow of processing executed by the communication system 100 of the embodiment. More specifically, Fig. 7 is a sequence diagram showing an example of the flow of processing executed by the communication system 100 in a case where the cooperation information indicates the average throughput of the terminals 900 and the number of active terminals 900 for each cell.

[0068] FIG. 7 shows an example of the flow of processing executed by the communication system 100, taking as an example a case where the result of the determination by the wavelength control determining unit 323 as to whether or not to execute wavelength allocation is a result that wavelength allocation is executed.

[0069] "Distributed station #1" means one of the distributed stations 2 included in the communication system 100, and "distributed station #2" means another distributed station 2 included in the communication system 100 that is different from "distributed station #1". "Allocation device #1" is the allocation device 4 corresponding to "distributed station #1". "Allocation device #2" is the allocation device 4 corresponding to "distributed station #2".

[0070] The wireless station 1 transmits information indicating the number of active terminals 900 for each cell to the management control device 3 (step S501). Next, the wireless station 1 transmits information indicating the average throughput of the terminals 900 to the management control device 3 (step S502). Either the process of step S501 or the process of step S502 may be executed first.

[0071] Next, the wavelength control determination unit 323 determines whether to execute wavelength allocation based on the cooperation information obtained in steps S501 and S502 (step S503). Next, the allocation control unit 33 transmits wavelength allocation notifications to the remote station #1, the remote station #2, and the central station 5 (step S504).

[0072] Next, the remote station #1, the remote station #2, and the central station 5 transmit a wavelength assignment response notification to the assignment control unit 33 (step S505). The wavelength assignment response notification is information indicating that the wavelength assignment notification has been received.

[0073] Next, the allocation control unit 33 notifies the distributed station #1, distributed station #2, and central station 5 of the time when communication will start after wavelength allocation (step S506). Next, the distributed station #1, distributed station #2, and central station 5 return a response to the notification of the time when communication will start after wavelength allocation to the allocation control unit 33 (step S507).

[0074] Next, the allocation control unit 33 transmits wavelength control information to each allocation device 4, "allocation device #1" and "allocation device #2" (step S508). Wavelength control information is an instruction for wavelength allocation. Wavelength control information is an example of control information. Next, the allocation control unit 33 notifies the distributed station #1, distributed station #2, and central station 5 of the start of wavelength allocation (step S509). Next, each allocation device 4, "allocation device #1" and "allocation device #2", notifies the allocation control unit 33 that wavelength allocation has been completed (step S510). Next, the distributed station #1, distributed station #2, and central station 5 notify the allocation control unit 33 that wavelength allocation has been completed (step S511).

[0075] It should be noted that the process of step S505 does not necessarily have to be executed. Even if there is no response after the allocation control unit 33 transmits the wavelength allocation notification, the processes from step S506 onward are executed. It should be noted that the process of step S508 may be executed before the process of step S507.

[0076] The communication system 100 of the embodiment configured as described above controls wavelength allocation not only when an unexpected event such as AMCC or SNMP occurs, but also repeatedly at a predetermined cycle, thereby making it possible for the communication system 100 to reduce the frequency of communication failures.

[0077] Furthermore, in the communication system 100 of the embodiment configured as described above, the management control device 3 directly acquires the cooperation information from the remote station 2 and controls the allocation of wavelengths. As a result, the communication system 100 can control the allocation of wavelengths with less time loss than when the cooperation information is transferred from the remote station 2 to a transfer destination, such as the core device 6, and then transferred from the transfer destination to the management control device 3. Therefore, the communication system 100 can reduce the frequency of occurrence of communication failures.

[0078] (First Modification) In the communication system 100 of the embodiment, the management control device 3 sends notifications to the remote stations 2 and the central station 5 as shown in the flowchart of Fig. 7. However, the notifications do not necessarily have to be sent from the management control device 3 to the remote stations 2 and the central station 5. The notifications may be sent from the allocation device 4 to the remote stations 2 and the central station 5, for example. An example of a sequence diagram for such a case is shown in Fig. 8.

[0079] Fig. 8 is a sequence diagram showing an example of the flow of processing executed by the communication system 100 of the modified example. More specifically, Fig. 8 is a sequence diagram showing an example of the flow of processing executed by the communication system 100 of the modified example, taking as an example a case where the cooperation information indicates the average throughput of the terminals 900 and the number of active terminals 900 for each cell.

[0080] FIG. 8 shows an example of the flow of processing executed by the communication system 100 of the modified example, taking as an example the result of the determination by the wavelength control determination unit 323 as to whether or not to execute wavelength allocation as a result of executing wavelength allocation.

[0081] "Distributed station #1" means one of the distributed stations 2 included in the communication system 100, and "distributed station #2" means another distributed station 2 included in the communication system 100 that is different from "distributed station #1". "Allocation device #1" is the allocation device 4 corresponding to "distributed station #1". "Allocation device #2" is the allocation device 4 corresponding to "distributed station #2".

[0082] The wireless station 1 transmits information indicating the number of active terminals 900 for each cell to the management control device 3 (step S601). Next, the wireless station 1 transmits information indicating the average throughput of the terminals 900 to the management control device 3 (step S602). Either the process of step S601 or the process of step S602 may be executed first.

[0083] Next, the wavelength control determination unit 323 determines whether or not to execute wavelength allocation based on the cooperation information obtained in steps S601 and S602 (step S603). Next, the allocation control unit 33 transmits wavelength control information to each of the allocation devices 4, "allocation device #1" and "allocation device #2" (step S604).

[0084] Next, each of the allocation devices 4, "allocation device #1" and "allocation device #2", transmits a wavelength allocation notification to the distributed station #1, distributed station #2, and central station 5 (step S605). Next, the distributed station #1, distributed station #2, and central station 5 transmit a wavelength allocation response notification to each of the allocation devices 4, "allocation device #1" and "allocation device #2" (step S606).

[0085] Next, each allocation device 4 of "allocation device #1" and "allocation device #2" notifies the remote station #1, remote station #2 and central station 5 of the time of start of communication after wavelength allocation (step S607). Next, the remote station #1, remote station #2 and central station 5 return a response to the notification of the time of start of communication after wavelength allocation to each allocation device 4 of "allocation device #1" and "allocation device #2" (step S608).

[0086] Next, each allocation device 4 of "allocation device #1" and "allocation device #2" notifies the distributed station #1, distributed station #2, and central station 5 of the start of wavelength allocation (step S609). Next, the distributed station #1, distributed station #2, and central station 5 notify each allocation device 4 of "allocation device #1" and "allocation device #2" that wavelength allocation has been completed (step S610). Next, each allocation device 4 of "allocation device #1" and "allocation device #2" notifies the allocation control unit 33 that wavelength allocation has been completed (step S611).

[0087] (Second Modification) Note that some or all of the functional units included in the management control device 3 may be included in the remote station 2. For example, the collection unit 31 and the analysis unit 32 may be included in the remote station 2 instead of the management control device 3.

[0088] (Third Modification) It should be noted that it is not necessary for each remote station 2 to have its own allocation device 4, and one allocation device 4 may be provided for a plurality of remote stations 2.

[0089] Fig. 9 is a diagram showing an example of the configuration of a communication system 100a in a third modified example. To simplify the following explanation, components equivalent to those in the communication system 100 are given the same reference numerals as in Fig. 1, and description thereof will be omitted. The communication system 100a differs from the communication system 100 in that the remote stations 2 and the allocation devices 4 have an N-to-1 relationship (N is an integer equal to or greater than 2) rather than a one-to-one relationship. The relationship between the allocation device 4 and the central station 5 in the communication system 100a is a one-to-one relationship, unlike that in the communication system 100. Therefore, in the communication system 100a, the relationship between the allocation device 4 and the central station 5 does not change regardless of the content of wavelength allocation.

[0090] Fig. 10 is a first sequence diagram showing an example of the flow of processing executed by the communication system 100a of the third modified example. More specifically, Fig. 10 is a sequence diagram showing an example of the flow of processing executed by the communication system 100a, taking as an example a case where the cooperation information indicates the average throughput of the terminals 900 and the number of active terminals 900 for each cell.

[0091] FIG. 10 shows an example of the flow of processing executed by the communication system 100a when the result of the determination by the wavelength control determining unit 323 as to whether or not to execute wavelength allocation is to execute wavelength allocation.

[0092] "Distributed station #1" means one of the distributed stations 2 included in the communication system 100a, and "distributed station #2" means another distributed station 2 included in the communication system 100a that is different from "distributed station #1".

[0093] The wireless station 1 transmits information indicating the number of active terminals 900 for each cell to the management control device 3 (step S701). Next, the wireless station 1 transmits information indicating the average throughput of the terminals 900 to the management control device 3 (step S702). Either the process of step S701 or the process of step S702 may be executed first.

[0094] Next, the wavelength control determination unit 323 determines whether to execute wavelength allocation based on the cooperation information obtained in steps S701 and S702 (step S703). Next, the allocation control unit 33 transmits wavelength allocation notifications to the remote station #1, the remote station #2, and the central station 5 (step S704).

[0095] Next, the remote station #1, the remote station #2, and the central station 5 transmit a wavelength assignment response notification to the assignment control unit 33 (step S705). The wavelength assignment response notification is information indicating that the wavelength assignment notification has been received.

[0096] Next, the allocation control unit 33 notifies the distributed station #1, distributed station #2, and central station 5 of the time when communication will start after wavelength allocation (step S706). Next, the distributed station #1, distributed station #2, and central station 5 return a response to the notification of the time when communication will start after wavelength allocation to the allocation control unit 33 (step S707).

[0097] Next, the allocation control unit 33 transmits wavelength control information to the allocation device 4 (step S708). Next, the allocation control unit 33 notifies the remote station #1, the remote station #2, and the central station 5 of the start of wavelength allocation (step S709). Next, the allocation device 4 notifies the allocation control unit 33 that wavelength allocation has been completed (step S710). Next, the remote station #1, the remote station #2, and the central station 5 notify the allocation control unit 33 that wavelength allocation has been completed (step S711).

[0098] It should be noted that the process of step S705 does not necessarily have to be executed. Even if there is no response after the allocation control unit 33 transmits the wavelength allocation notification, the processes from step S706 onward are executed. It should be noted that the process of step S708 may be executed before the process of step S707.

[0099] 10, the management control device 3 sends a notification to the remote station 2 and the central station 5. However, the notification does not necessarily have to be sent from the management control device 3 to the remote station 2 and the central station 5. The notification may be sent from the allocation device 4 to the remote station 2 and the central station 5, for example. A second sequence diagram showing an example of the flow of processing executed in the communication system 100a in such a case is shown in FIG.

[0100] Fig. 11 is a second sequence diagram showing an example of the flow of processing executed by the communication system 100a of the third modified example. More specifically, Fig. 11 is a sequence diagram showing an example of the flow of processing executed by the communication system 100a, taking as an example a case where the cooperation information indicates the average throughput of the terminals 900 and the number of active terminals 900 for each cell.

[0101] FIG. 11 shows an example of the flow of processing executed by the communication system 100a in the case where the result of the determination by the wavelength control determining unit 323 as to whether or not to execute wavelength allocation is to execute wavelength allocation.

[0102] The wireless station 1 transmits information indicating the number of active terminals 900 for each cell to the management control device 3 (step S801). Next, the wireless station 1 transmits information indicating the average throughput of the terminals 900 to the management control device 3 (step S802). Either the process of step S801 or the process of step S802 may be executed first.

[0103] Next, the wavelength control determination unit 323 determines whether or not to execute wavelength allocation based on the cooperation information obtained in steps S801 and S802 (step S803). Next, the allocation control unit 33 transmits wavelength control information to the allocation device 4 (step S804).

[0104] Next, the allocation device 4 transmits a wavelength allocation notification to the distributed station #1, the distributed station #2, and the central station 5 (step S805). Next, the distributed station #1, the distributed station #2, and the central station 5 transmit wavelength allocation response notifications to the allocation device 4 (step S806).

[0105] Next, the allocation device 4 notifies the remote station #1, the remote station #2, and the central station 5 of the time when communication will start after wavelength allocation (step S807). Next, the remote station #1, the remote station #2, and the central station 5 return a response to the notification of the time when communication will start after wavelength allocation to the allocation device 4 (step S808).

[0106] Next, the allocation device 4 notifies the distributed station #1, distributed station #2, and central station 5 of the start of wavelength allocation (step S809). Next, the distributed station #1, distributed station #2, and central station 5 notify the allocation device 4 that wavelength allocation has been completed (step S810). Next, the allocation device 4 notifies the allocation control unit 33 that wavelength allocation has been completed (step S811).

[0107] (Example of hardware configuration) FIG. 12 is a diagram illustrating an example of the hardware configuration of the management control device 3 in each embodiment and modification. Some or all of the functional units of the management control device 3 are realized as software by a processor 301, such as a CPU (Central Processing Unit), executing programs stored in a storage device 302 having a non-volatile storage medium (non-transitory storage medium) and a storage unit 303. The programs may be recorded on a computer-readable non-transitory storage medium. Examples of computer-readable non-transitory storage media include portable media such as flexible disks, magneto-optical disks, ROMs (Read Only Memory), and CD-ROMs (Compact Disc Read Only Memory), and storage devices such as hard disks built into a computer system. A communication unit 304 executes predetermined communication processing. The communication unit 304 may acquire data and programs.

[0108] Some or all of the functional units of the management control device 3 may be realized using hardware including electronic circuits (electronic circuits or circuitry) using, for example, an LSI (Large Scale Integrated circuit), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).

[0109] FIG. 13 is a diagram illustrating an example of the hardware configuration of the allocation device 4 in each embodiment and modification. Some or all of the functional units of the allocation device 4 are realized as software by a processor 401, such as a CPU, executing a program stored in a storage device 402 having a non-volatile storage medium (non-transitory storage medium) and a storage unit 403. The program may be recorded on a computer-readable non-transitory storage medium. Examples of computer-readable non-transitory storage media include portable media such as flexible disks, optical magnetic disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into a computer system. A communication unit 404 executes predetermined communication processing. The communication unit 404 may acquire data and programs.

[0110] Some or all of the functional units of the allocation device 4 may be realized using hardware including electronic circuits using, for example, LSI, ASIC, PLD, FPGA, or the like.

[0111] FIG. 14 is a diagram illustrating an example of the hardware configuration of a remote station 2 in each embodiment and modification. Some or all of the functional units of the remote station 2 are realized as software by a processor 201, such as a CPU, executing a program stored in a storage device 202 having a non-volatile recording medium (non-transitory recording medium) and a storage unit 203. The program may be recorded on a computer-readable non-transitory recording medium. Examples of computer-readable non-transitory recording media include portable media such as flexible disks, magneto-optical disks, ROMs, and CD-ROMs, and storage devices such as hard disks built into a computer system. A communication unit 204 executes predetermined communication processing. The communication unit 204 may acquire data and programs.

[0112] Some or all of the functional units of the remote station 2 may be realized using hardware including electronic circuits using, for example, LSI, ASIC, PLD, FPGA, or the like.

[0113] Each of the remote station 2, the management control device 3, and the allocation device 4 may be implemented using a plurality of information processing devices communicably connected via a network. In this case, each functional unit included in each of the remote station 2, the management control device 3, and the allocation device 4 may be distributed and implemented in a plurality of information processing devices.

[0114] The embodiments may be combined.

[0115] Although an embodiment of the present invention has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the gist of the present invention. [Industrial Applicability]

[0116] The present invention is applicable to optical communication systems such as optical access systems. [Explanation of symbols]

[0117] 100...communication system, 1...radio station, 2...distributed station, 3...management control device, 4...allocation device, 5...aggregation station, 6...core device, 31...collection unit, 32...analysis unit, 33...allocation control unit, 311...cooperation information receiving unit, 321...cooperation information storage unit, 322...real-time analysis unit, 323...wavelength control determination unit, 331...allocation destination wavelength setting unit, 332...wavelength control signal generation unit, 201...processor, 202...storage device, 203...storage unit, 204...communication unit, 301...processor, 302...storage device, 303...storage unit, 304...communication unit, 401...processor, 402...storage device, 403...storage unit, 404...communication unit, 900...terminal, 910...network

Claims

1. A control device for reducing the frequency of occurrence of communication failures in a communication system including a radio station having an antenna, a remote station that receives an uplink signal transmitted by the radio station, an allocation device that allocates wavelengths to communications using optical signals, and a central station that aggregates the uplink signals transmitted by the remote station, a collection unit that acquires, at a predetermined cycle, link information that indicates a state of communication between the communication system and a communication target terminal; an analysis unit that determines whether wavelength allocation is necessary and identifies wavelengths to be allocated based on the communication state indicated by the collaboration information so as to reduce the frequency of occurrence of communication failures; an allocation control unit that controls the allocation device to allocate the wavelengths identified by the analysis unit for optical communication between the remote station and the central station; A control device comprising:

2. the cooperation information includes an average throughput of the terminals and the number of the terminals communicating with each of the wireless stations, for each of the wireless stations; The control device according to claim 1 .

3. The cooperation information includes an average throughput of the terminal and registration information of the terminal. The control device according to claim 1 .

4. The cooperation information includes scheduling information including traffic volume of each terminal 900. The control device according to claim 1 .

5. the collection unit acquires the cooperation information from a remote station that acquires a signal transmitted by the wireless station. The control device according to any one of claims 1 to 4.

6. A communication system that reduces the frequency of occurrence of communication failures in its own system, a radio station having an antenna; a remote station for receiving an uplink signal transmitted by the radio station; an allocation device that allocates wavelengths to communications using optical signals; a central station that aggregates the upstream signals transmitted from the remote stations; a collection unit that acquires, at a predetermined period, link information that indicates the state of communication between the system itself and a communication target terminal; an analysis unit that determines whether wavelength allocation is necessary and identifies wavelengths to be allocated based on the communication state indicated by the collaboration information so as to reduce the frequency of occurrence of communication failures; an allocation control unit that controls the allocation device to allocate the wavelengths identified by the analysis unit for optical communication between the remote station and the central station; A communication system comprising:

7. a collection step of periodically acquiring, at a predetermined interval, coordination information that indicates a state of communication between a communication system that includes a radio station having an antenna, a distributed station that receives an uplink signal transmitted from the radio station, an allocation device that allocates wavelengths to communications using optical signals, and a central station that aggregates the uplink signals transmitted from the distributed station, the communication system suppressing the frequency of occurrence of communication failures in the system itself and a terminal with which communication is to be performed; an analysis step of determining whether wavelength allocation is necessary and specifying wavelengths to be allocated based on the communication state indicated by the collaboration information so as to reduce the frequency of occurrence of communication failures; an allocation control step of controlling the allocation device to allocate the wavelengths identified in the analysis step for optical communication between the remote station and the central station; A control method comprising:

8. A program for causing a computer to function as the control device according to any one of claims 1 to 5.

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