CONTROL APPARATUS, COMMUNICATION SYSTEM, CONTROL METHOD AND PROGRAM

A control device including a collection unit that acquires, at a predetermined cycle, cooperation information, which is information indicating a communication state between a communication system that includes a wireless station including an antenna and an allocation device that allocates a wavelength, and a terminal to be communicated, an analysis unit that analyzes the communication state in the communication system on the basis of the cooperation information, and an allocation control unit that controls execution of wavelength allocation by the allocation device on the basis of an analysis result of the analysis unit.

TECHNICAL FIELD

The present invention relates to a control apparatus, a communication system, a control method, and a program.

BACKGROUND ART

There is a technique for detecting a failure or an error of a network device, which is a device constituting an optical communication system such as an AMCC (Auxiliary Management and Control Channel) or an SNMP (Simple Network Management Protocol), and instructing allocation to a spare wavelength or allocation of the network device when the failure or the error occurs. In such a technique, information on an occurrence of the failure or the error of the network device is acquired, and allocation to the spare wavelength or instructing allocation of the network device is performed. An interval for monitoring is defined as a minute unit.

CITATION LIST

Non Patent Literature

SUMMARY OF INVENTION

Technical Problem

However, when traffic fluctuation occurs due to an unexpected event such as a disaster or a delay of a train, the AMCC and SNMP cannot acquire information on the unexpected traffic fluctuation, and cannot perform band control by real-time wavelength reallocation. As a result, a communication error may occur, such as an occurrence of conflict due to a network congestion.

In view of the above circumstances, an object of the present invention is to provide a technique for suppressing a frequency of communication error occurrence.

Solution to Problem

One aspect of the present invention is a control device including a collection unit that acquires, at a predetermined cycle, cooperation information, which is information indicating a communication state between a communication system that includes a wireless station including an antenna and an allocation device that allocates a wavelength, and a terminal to be communicated, an analysis unit that analyzes the communication state in the communication system on the basis of the cooperation information, and an allocation control unit that controls execution of wavelength allocation by the allocation device on the basis of an analysis result of the analysis unit.

One aspect of the present invention is a communication system comprising: a wireless station including an antenna, an allocation device that allocates a wavelength, a collection unit configured to acquire, at a predetermined cycle, cooperation information, which is information indicating a communication state between the system per se and a terminal to be communicated; an analysis unit configured to analyze the communication state in the system on the basis of the cooperation information; and an allocation control unit configured to control execution of wavelength allocation by the allocation device on the basis of an analysis result of the analysis unit.

One aspect of the present invention is a control method including a collection step of acquiring, at a predetermined cycle, cooperation information, which is information indicating a communication state between a communication system that includes a wireless station including an antenna and an allocation device that allocates a wavelength, and a terminal to be communicated, an analysis step of analyzing the communication state in the communication system on the basis of the cooperation information, and an allocation control step of controlling execution of wavelength allocation by the allocation device on the basis of an analysis result of the analysis unit.

One aspect of the present invention is a program for causing a computer to function as the above-mentioned control device.

Advantageous Effects of Invention

According to the present invention, the frequency of communication error occurrence can be suppressed.

DESCRIPTION OF EMBODIMENTS

Embodiment

FIG.1is a diagram showing a configuration example of a communication system100according to an embodiment. The communication system100is a system for performing communication using optical signals. The communication system100acquires signals of terminals900to be communicated. The terminal900is, for example, a mobile wireless terminal such as a smartphone. The communication system100transmits the acquired signals to an external network910.

The communication system100includes M wireless stations1, M distributed stations2, a management control device3, M allocation devices4, an aggregation station5and a core device6. M is an integer equal to or larger than 1. That is, the communication system100includes one or a plurality of wireless stations1, one or a plurality of distributed stations2, and the same number of allocation devices4as the distributed stations2. The distributed station2and the allocation device4correspond to each other in one-to-one correspondence.

The wireless station1receives the signals transmitted by the terminal900and transmits the signals to the terminal900. Therefore, the wireless station1is a device having an antenna. The wireless station1is, for example, a RU (Radio Unit) in a 5G communication standard.

The distributed station2is connected to the wireless station1by an optical fiber. The distributed station2receives upstream signals transmitted by the wireless station1. The distributed station2transmits downstream signals to the wireless station1. Note that the upstream signals are signals transmitted by the terminal900, and the downstream signals are signals propagating toward the terminal900. Each distributed station2is connected to a plurality of wireless stations1. That is, the distributed station2and the wireless station1have a one-to-M correspondence relationship. The distributed station2is, for example, a DU (Distributed Unit) in the 5G communication standard. Information acquired by the management control device3from the distributed station2will be referred to as cooperation information. The cooperation information is information indicating a communication state between the communication system100(that is, system per se) and the terminal900.

The cooperation information includes, for example, an average throughput of the terminals900. The cooperation information includes, for example, the number of terminals900with which the wireless station1communicates for each wireless station1. The cooperation information includes, for example, registration information of the terminal900. Note that the registration information of the terminal900is information indicating a PDU session setting request of the terminal900. The cooperation information includes, for example, scheduling information including a traffic amount of each terminal900. Note that the scheduling information is information indicating transmission timing and transmission data amount of user data allocated to each terminal900by the distributed station2.

The management control device3acquires the cooperation information from the distributed station2. The management control device3acquires a wavelength allocation notification having a content based on the acquired cooperation information. The wavelength allocation notification is information indicating how wavelength allocation is performed. More specifically, the wavelength allocation notification is information indicating how the wavelength allocation is performed by each allocation device4. The wavelength allocation may be processing of wavelength switching, processing of newly added wavelength allocation, or processing of reallocating remaining wavelength after a part of wavelengths is deleted. The management control device3controls the operation of the allocation device4to execute the content of the wavelength allocation notification.

The allocation device4performs allocation indicated by the wavelength allocation notification transmitted by the management control device3. Therefore, the allocation device4is a device for allocating wavelength by receiving control of the management control device3. That is, the management control device3is a device for controlling the execution of wavelength allocation. The allocation device4notifies the management control device3of the completion of the wavelength allocation processing at the timing when the wavelength allocation is completed. Hereinafter, the notification indicating that the wavelength allocation processing has been completed is referred to as an allocation completion notification.

The aggregation station5aggregates the upstream signals transmitted by the distributed station2. The aggregation station5distributes the downstream signals. The aggregation station5is, for example, a CU (Centralized Unit) in the 5G communication standard.

The core device6executes signal processing on the upstream signals aggregated by the aggregation station5. The core device6transmits signals obtained as a result of execution of signal processing on the upstream signals to an external network910. In addition, the core device6receives the signals from the external network910.

The core device6performs preset predetermined signal processing on signals received from the external network910. The core device6transmits signals obtained as a result of execution of signal processing on the signals received from the external network910to the aggregation station5as the downstream signals. The signal processing is, for example, a transfer of user data in a UPF (User Plane Function) of a 5G core network.

FIG.2is a diagram showing an example of a configuration of the management control device3according to the embodiment. The management control device3includes a collection unit31, an analysis unit32, and an allocation control unit33.

The collection unit31includes a cooperation information reception unit311. The cooperation information reception unit311acquires the cooperation information from the distributed station2.

The analysis unit32includes a cooperation information accumulation unit321, a real-time analysis unit322, and a wavelength control judgement unit323. The cooperation information accumulation unit321records the acquired cooperation information in a predetermined storage device. The predetermined device is, for example, a storage device302which will be described later. The real-time analysis unit322analyzes the communication state in the communication system100for a change amount of the number of connections per band or unit time, and the like on the basis of the cooperation information.

The wavelength control judgement unit323judges whether or not to reallocate the wavelength on the basis of the analysis result of the real-time analysis unit322. For example, the wavelength control judgement unit323compares the analysis result of the real-time analysis unit322with a predetermined threshold value or a band currently allocated, and judges whether or not to reallocate the wavelength. Reallocation of wavelength means addition or deletion of wavelength. The allocation destination wavelength setting unit331may judge a wavelength to be added and a wavelength not used in the allocation, and determine the wavelength of the allocation destination on the basis of the judgement result.

In this way, the analysis unit32judges whether or not to allocate the wavelength on the basis of the cooperation information.

The allocation control unit33determines how the wavelength allocation is to be performed when the analysis unit32determines that the wavelength is to be allocated. Then, the allocation control unit33transmits the wavelength allocation notification to control the operation of the allocation device4so that the determined content is executed. Specifically, the operation of the allocation device4by the allocation control unit33is controlled by transmitting control information, which is information indicating the operation executed by the allocation device4, to the allocation device4by the allocation control unit33.

The allocation control unit33includes an allocation destination wavelength setting unit331, and a wavelength control signal generation unit332. The allocation destination wavelength setting unit331determines a transmission destination of the wavelength allocation notification. The transmission destination is, for example, the allocation device4. The allocation destination wavelength setting unit331may determine the content of wavelength allocation. The allocation destination wavelength setting unit331may judge, for example, a wavelength to be added and a wavelength not used in the allocation, and determine the wavelength of the allocation destination on the basis of a judgement result.

The wavelength control signal generation unit332generates the wavelength allocation notification, and notifies a predetermined notification destination of the generated wavelength allocation notification. In addition, the wavelength control signal generation unit332generates control information on the basis of the content of the wavelength allocation notification and predetermined information indicating the operable content of the allocation device4. The control information generated in this way is information indicating the operation of the allocation device4which realizes the content of the wavelength allocation notification. The wavelength control signal generation unit332transmits the generated control information to the allocation device4.

Thus, the allocation control unit33determines the transmission destination of the wavelength allocation notification and controls the allocation device4to execute the determined contents by the allocation destination wavelength setting unit331and the wavelength control signal generation unit332. That is, the allocation control unit33controls execution of wavelength allocation by the allocation device4on the basis of the analysis result of the analysis unit32.

The determination of the content of the wavelength allocation notification is determined by the allocation destination wavelength setting unit331.

FIG.3is a first flowchart showing an example of a flow of processing executed by the management control device3according to the embodiment. More specifically,FIG.3is a flowchart showing an example of a flow of processing executed by the management control device3, as an example, in a case where the cooperation information indicates an average throughput of the terminals900and the number of active terminals900for each cell. The flow of the processing shown inFIG.3is not executed only when an unexpected event such as an AMCC (Auxiliary Management and Control Channel) or an SNMP (Simple Network Management Protocol) occurs, but is repeatedly executed at a predetermined cycle.

Note that the number of active terminals900for each cell is the number of terminals900with which each wireless station1is communicating for each wireless station1. Hereinafter, the average throughput of the terminals900is referred to as terminal average throughput. Hereinafter, the number of active terminals900for each cell is referred to as terminal active number.

The cooperation information reception unit311acquires the cooperation information from the distributed station2(step S101). Next, the real-time analysis unit322adds the number of active terminals900of all cells for each unit time on the basis of the terminal active number included in the acquired cooperation information (step S102). Note that the addition of the number of active terminals900of all cells for each unit time means the acquisition of the number of terminals900with which each distributed station2is communicating in each unit time. Hereinafter, the number of terminals900with which each distributed station2is communicating in each unit time is referred to as all active terminal number.

Next, the real-time analysis unit322calculates a band satisfying a predetermined condition (hereinafter referred to as “error frequency occurrence condition”) regarding the low frequency of the communication error occurrence on the basis of the terminal average throughput and all active terminal number (step S103). The error frequency occurrence condition is, for example, a condition that the frequency of the communication error occurrence is lower than a preset predetermined frequency. The predetermined frequency is, for example, a condition that the frequency of occurrence per unit time is one or less.

The real-time analysis unit322calculates, for example, a product of the terminal average throughput and all active terminal number, and acquires a calculation result as the band satisfying the error frequency occurrence condition. The processing in the step S102and the step S103is an analysis of the communication state in the communication system100by the real-time analysis unit322, and an example of analysis based on the cooperation information.

Next, the wavelength control judgement unit323judges whether or not width of the band satisfying the error frequency generation condition is wider than the width of allocated band at the present time (step S104). Note that the band at the present time means a band in use. When the width of the band satisfying the error frequency occurrence condition is wider than the width of the allocated band at the present time (step S104: YES), the allocation control unit33transmits the wavelength allocation notification (step S105).

Next, the allocation device4executes the content of the wavelength allocation notification (step S106). On the other hand, when the width of the band satisfying the error frequency occurrence condition is equal to or less than the width of the allocated band at the present time (step S104: NO), the allocation control unit33does not transmit the wavelength allocation notification (step S107). When the wavelength allocation notification is not transmitted, the allocation device4does not perform the reallocation of the wavelength. Thus, the allocation control unit33controls the operation of the allocation device4according to whether or not to transmit the wavelength allocation notification and the content of the wavelength allocation notification.

Note that, in this way, since the wavelength allocation notification is transmitted or not transmitted in accordance with the judgement result of the step S104, the processing of the step S104is processing of judging whether or not to reallocate the wavelength. Note that the wavelength allocation notification of the processing in the step S105may be a notification of wavelength allocation including addition and deletion of wavelengths.

The content of the wavelength allocation notification is determined by the allocation destination wavelength setting unit331. The content of the wavelength allocation notification is determined on the basis of band information calculated by the real-time analysis unit322by the allocation destination wavelength setting unit331after the step S105is performed. For example, the allocation destination wavelength setting unit331judges a wavelength having a small number of active terminals as a reallocation destination. The allocation destination wavelength setting unit331determines the allocation device4of the transmission destination of the wavelength allocation notification.

FIG.4is a second flowchart showing an example of a flow of processing executed by the management control device3according to the embodiment. More specifically,FIG.4is a flowchart showing an example of a flow of processing executed by the management control device3, as an example, in a case where the cooperation information is the average throughput of the terminals900(that is, a terminal average throughput) and registration information of the terminal900.

The flow of the processing shown inFIG.4is not executed only when the unexpected event such as AMCC or SNMP occurs, but is repeatedly executed at the predetermined cycle.

The cooperation information reception unit311acquires the cooperation information from the distributed station2(step S201). Next, the real-time analysis unit322calculates the number of terminals900for each unit time on the basis of registration information of the terminal900among information included in the cooperation information (step S202). Next, the real-time analysis unit322calculates a band satisfying the error frequency occurrence condition on the basis of the terminal average throughput and the number of terminals900per unit time (step S203).

The real-time analysis unit322calculates, for example, a product of the terminal average throughput and the number of terminals900per unit time, and acquires a calculation result as the band satisfying the error frequency occurrence condition. The processing in the step S202and the step S203is an analysis of the communication state in the communication system100by the real-time analysis unit322, and an example of analysis based on the cooperation information.

Next, the wavelength control judgement unit323judges whether or not width of the band satisfying the error frequency generation condition is wider than the width of the allocated band at the present time (step S204). When the width of the band satisfying the error frequency occurrence condition is wider than the width of the allocated band at the present time (step S204: YES), the allocation control unit33transmits the wavelength allocation notification (step S205).

Next, the allocation device4executes the content of the wavelength allocation notification (step S206). On the other hand, when the width of the band satisfying the error frequency occurrence condition is equal to or less than the width of the allocated band at the present time (step S204: NO), the allocation control unit33does not transmit the wavelength allocation notification (step S207). When the wavelength allocation notification is not transmitted, the allocation device4does not perform the re-allocation of the wavelength. Thus, the allocation control unit33controls the operation of the allocation device4according to whether or not to transmit the wavelength allocation notification and the content of the wavelength allocation notification.

Note that, in this way, since the wavelength allocation notification is transmitted or not transmitted in accordance with the judgement result of the step S204, the processing of the step S204is processing for judging whether or not to reallocate the wavelength. Note that the wavelength allocation notification of the processing in the step S205may be a notification of wavelength allocation including addition and deletion of wavelengths.

The content of the wavelength allocation notification is determined, for example, by the wavelength control judgement unit323of the analysis unit32. The content of the wavelength allocation notification may be determined by the allocation destination wavelength setting unit331. The content of the wavelength allocation notification is determined on the basis of band information calculated by the real-time analysis unit322by the allocation destination wavelength setting unit331after the step S205is performed. For example, the allocation destination wavelength setting unit331judges a wavelength having a small number of terminals per unit time as a reallocation destination. The allocation destination wavelength setting unit331determines the allocation device4of the transmission destination of the wavelength allocation notification.

FIG.5is a third flowchart showing an example of a flow of processing executed by the management control device3according to the embodiment. More specifically,FIG.5is a flow chart showing an example of a flow of processing executed by the management control device3, as an example, in a case where the cooperation information is scheduling information.

The flow of the processing shown inFIG.5is not executed only when the unexpected event such as AMCC or SNMP occurs, but is repeatedly executed at the predetermined cycle.

The cooperation information reception unit311acquires the cooperation information from the distributed station2(step S301). Next, the real-time analysis unit322adds the traffic amount of each terminal900included in the cooperation information to all the terminals900(step S302). That is, in the step S302, the real-time analysis unit322adds the transmission data amount of each scheduling information, and acquires a calculation result as the band satisfying the error frequency generation condition.

The processing in the step S302is an analysis of the communication state in the communication system100by the real-time analysis unit322, and an example of analysis based on the cooperation information.

Next, the wavelength control judgement unit323judges whether or not the width of the band satisfying the error frequency generation condition is wider than the width of an allocated band at the present time (step S303). When the width of the band satisfying the error frequency occurrence condition is wider than the width of the allocated band at the present time (step S303: YES), the allocation control unit33transmits the wavelength allocation notification (step S304).

Next, the allocation device4executes the content of the wavelength allocation notification (step S305). On the other hand, when the width of the band satisfying the error frequency occurrence condition is equal to or less than the width of the allocated band at the present time (step S303: NO), the allocation control unit33does not transmit the wavelength allocation notification (step S306). When the wavelength allocation notification is not transmitted, the allocation device4does not perform the reallocation of the wavelength. Thus, the allocation control unit33controls the operation of the allocation device4according to whether or not to transmit the wavelength allocation notification and the content of the wavelength allocation notification.

Note that, in this way, since the wavelength allocation notification is transmitted or not transmitted in accordance with the judgement result of the step S303, the processing of the step S303is processing for judging whether or not to reallocate the wavelength. Note that the wavelength allocation notification of the processing in the step S304may be a notification of wavelength allocation including addition and deletion of wavelengths.

The content of the wavelength allocation notification is determined, for example, by the wavelength control judgement unit323of the analysis unit32. The content of the wavelength allocation notification may be determined by the allocation destination wavelength setting unit331. The content of the wavelength allocation notification is determined based on the band information calculated by the real-time analysis unit322by the allocation destination wavelength setting unit331after the step S304is performed. For example, the allocation destination wavelength setting unit331judges a wavelength in which a current band is larger than a required band as a reallocation destination. The allocation destination wavelength setting unit331determines the allocation device4of the transmission destination of the wavelength allocation notification.

FIG.6is a fourth flowchart showing an example of a flow of processing executed by the management control device3according to the embodiment. More specifically,FIG.6is a flow chart showing an example of a flow of processing executed by the management control device3, as an example, in a case where one piece of the cooperation information is registration information of the terminal900.

The flow of the processing shown inFIG.6is not executed only when the unexpected event such as AMCC or SNMP occurs, but is repeatedly executed at the predetermined cycle.

The cooperation information reception unit311acquires the registration information of the terminal900from the distributed station2(step S401). Next, the real-time analysis unit322calculates the increase/decrease of the number of terminals900for each unit time on the basis of the registration information of the terminal900(step S402). Next, the wavelength control judgement unit323judges whether or not the magnitude of the increase/decrease obtained in the step S402is equal to or larger than a preset predetermined threshold value (step S403).

When the magnitude of the increase/decrease is not equal to or larger than the threshold value (step S403: NO), the processing is terminated. On the other hand, when the magnitude of the increase/decrease is equal to or larger than the threshold value (step S403: YES), the cooperation information reception unit311acquires the average throughput (that is, terminal average throughput) of the terminals900from the distributed station2(step S404). Next, the real-time analysis unit322calculates the band satisfying the error frequency occurrence condition on the basis of the terminal average throughput and the number of terminals900per unit time (step S405).

The real-time analysis unit322calculates, for example, a product of the terminal average throughput and the number of terminals900per unit time, and acquires a calculation result as the band satisfying the error frequency occurrence condition. The processing of the step S402and the step S405is an analysis of the communication state in the communication system100by the real-time analysis unit322, and an example of analysis based on the cooperation information.

Next, the allocation control unit33transmits the wavelength allocation notification (step S406). Next, the allocation device4executes the content of the wavelength allocation notification (step S407).

Note that when the magnitude of the increase/decrease is not judged to be equal to or larger than the threshold value in the step S403as shown by the flow of the processing inFIG.6, the wavelength allocation notification is not transmitted. That is, when the magnitude of the increase/decrease is not judged to be equal to or larger than the threshold value in the step S403, the allocation control unit33does not transmit the wavelength allocation notification. In this way, the allocation control unit33controls the operation of the allocation device4according to whether or not to transmit the wavelength allocation notification and the content of the wavelength allocation notification.

Note that, in this way, since the wavelength allocation notification is transmitted or not transmitted in accordance with the judgement result of the step S403, the processing of the step S403is processing for judging whether or not to reallocate the wavelength. Note that the wavelength allocation notification of the processing in the step S406may be a notification of wavelength allocation including addition and deletion of wavelengths.

The content of the wavelength allocation notification is determined, for example, by the wavelength control judgement unit323of the analysis unit32. The content of the wavelength allocation notification may be determined by the allocation destination wavelength setting unit331. The content of the wavelength allocation notification is determined based on the band information calculated by the real-time analysis unit322by the allocation destination wavelength setting unit331after the step S406is performed. For example, the allocation destination wavelength setting unit331determines a wavelength having a large reduction in the number of terminals per unit time as a reallocation destination. The allocation destination wavelength setting unit331determines the allocation device4of the transmission destination of the wavelength allocation notification.

As shown inFIG.3toFIG.6, the wavelength control judgement unit323judges whether or not to execute the wavelength allocation on the basis of the cooperation information. More specifically, the wavelength control judgement unit323judges whether or not to execute the wavelength allocation on the basis of a result of analysis based on the cooperation information, which is the analysis of the communication state in the communication system100by the real-time analysis unit322. Then, as shown inFIG.3toFIG.6, the allocation control unit33controls execution of the wavelength allocation by the allocation device4according to whether or not to transmit the wavelength allocation notification and the content of the wavelength allocation notification.

FIG.7is a sequence diagram showing an example of a flow of processing executed by the communication system100of the embodiment. More specifically,FIG.7is a sequence diagram showing an example of a flow of processing executed by the communication system100, as an example, in a case where the cooperation information indicates the average throughput of the terminals900and the number of active terminals900for each cell.

In addition,FIG.7shows an example of a flow of processing executed by the communication system100, as an example, in a case where the result of the judgement as to whether or not to execute the wavelength allocation by the wavelength control judgement unit323is a result of executing the wavelength allocation.

“Distributed station #1” means one of the distributed stations2provided in the communication system100, and “distributed station #2” is one of the distributed stations provided in the communication system100and means another distributed station2which is different from “distributed station #1”.

“Allocation device #1” is the allocation device4corresponding to “distributed station #1”. “Allocation device #2” is the allocation device4corresponding to “distributed station #2”.

Information indicating the number of active terminals900for each cell is transmitted from the wireless station1to the management control device3(step S501). Next, information indicating the average throughput of the terminals900is transmitted from the wireless station1to the management control device3(step S502). For the processing of step S501and the processing of step S502, any one may be executed before the other one.

Next, the wavelength control judgement unit323judges whether or not to execute the wavelength allocation on the basis of the cooperation information obtained in the step S501and the step S502(step S503). Next, the allocation control unit33transmits the wavelength allocation notification to the distributed station #1, the distributed station #2and the aggregation station5(step S504).

Next, the distributed station #1, the distributed station #2and the aggregation station5transmit a wavelength allocation response notification to the allocation control unit33(step S505). The wavelength allocation response notification is information indicating that the wavelength allocation notification has been received.

Next, the allocation control unit33notifies the distributed station #1, the distributed station #2and the aggregation station5of the start time of communication after the wavelength allocation (step S506). Next, the distributed station #1, the distributed station #2and the aggregation station5return a response to the notification of the start time of communication after the wavelength allocation to the allocation control unit33(step S507).

Next, the allocation control unit33transmits wavelength control information to each allocation device4of “allocation device #1” and “allocation device #2” (step S508). The wavelength control information is an instruction to allocate a wavelength. The wavelength control information is an example of control information. Next, the allocation control unit33notifies the distributed station #1, the distributed station #2and the aggregation station5of the start of wavelength allocation (step S509). Next, each allocation device4of “allocation device #1” and “allocation device #2” notifies the allocation control unit33of completion of the wavelength allocation (step S510). Next, the distributed station #1, the distributed station #2and the aggregation station5notify the allocation control unit33of the completion of the wavelength allocation (step S511).

Note that it is not always necessary to execute processing of step S505. In this way, even when there is no response after the allocation control unit33transmits the wavelength allocation notification, processing after the step S506is executed. Note that the processing of step S508may be executed before the processing of step S507.

The communication system100of the embodiment constituted in this way repeatedly executes the wavelength allocation control not only when the unexpected event such as AMCC and SNMP occurs, but also at the predetermined cycle. Therefore, in the communication system100, it is possible to suppress a frequency of communication error occurrence.

Further, in the communication system100of the embodiment constituted in this way, the management control device3directly acquires the cooperation information from the distributed station2and executes the control of wavelength allocation. As a result, the communication system100can perform the wavelength allocation control with less time loss compared to a case where the cooperation information is transferred from the distributed station2to a transfer destination such as the core device6and then transferred from the transfer destination to the management control device3, for example. Therefore, in the communication system100, it is possible to suppress the frequency of communication error occurrence.

First Modified Example

In the communication system100of the embodiment, the management control device3notifies the distributed station2and the aggregation station5as shown in the flowchart ofFIG.7. However, it is not always necessary to transmit the notification from the management control device3to the distributed station2and the aggregation station5. The notification may be transmitted from the allocation device4to the distributed station2and the aggregation station5, for example. An example of sequence diagram for such a case is shown inFIG.8.

FIG.8is a sequence diagram showing an example of a flow of processing executed by the communication system100of the modified example. More specifically,FIG.8is a sequence diagram showing an example of a flow of processing executed by the communication system100of the modified example, as an example, in a case where the cooperation information indicates the average throughput of the terminals900and the number of active terminals900for each cell.

In addition,FIG.8shows an example of a flow of processing executed by the communication system100of the modified example, as an example, in a case where the result of the judgement as to whether or not to execute the wavelength allocation by the wavelength control judgement unit323is a result of executing the wavelength allocation.

“Distributed station #1” means one of the distributed stations2provided in the communication system100, and “distributed station #2” is one of the distributed stations provided in the communication system100and means another distributed station2which is different from “distributed station #1”. “Allocation device #1” is the allocation device4corresponding to “distributed station #1”. “Allocation device #2” is the allocation device4corresponding to “distributed station #2”.

Information indicating the number of active terminals900for each cell is transmitted from the wireless station1to the management control device3(step S601). Next, information indicating the average throughput of the terminals900is transmitted from the wireless station1to the management control device3(step S602). For the processing of step S601and the processing of step S602, any one may be executed before the other one.

Next, the wavelength control judgement unit323judges whether or not to execute the wavelength allocation on the basis of the cooperation information obtained in the step S601and the step S602(step S603). Next, the allocation control unit33transmits the wavelength control information to each allocation device4of “allocation device #1” and “allocation device #2” (step S604).

Next, each allocation device4of “allocation device #1” and “allocation device #2” transmits the wavelength allocation notification to the distributed station #1, the distributed station #2and the aggregation station5(step S605). Next, the distributed station #1, the distributed station #2and the aggregation station5transmit the wavelength allocation response notification to each allocation device4of “allocation device #1” and “allocation device #2” (step S606).

Next, each allocation device4of “allocation device #1” and “allocation device #2” notifies the distributed station #1, the distributed station #2and the aggregation station5of the start time of communication after the wavelength allocation (step S607). Next, the distributed station #1, the distributed station #2and the aggregation station5return the response to the notification of the start time of communication after the wavelength allocation to each allocation device4of “allocation device #1” and “allocation device #2” (step S608).

Next, each allocation device4of “allocation device #1” and “allocation device #2” notifies the start of wavelength allocation to the distributed station #1, the distributed station #2and the aggregation station5(step S609). Next, the distributed station #1, the distributed station #2and the aggregation station5notify each allocation device4of “allocation device #1” and “allocation device #2” of the completion of the wavelength allocation (step S610). Next, each allocation device4“allocation device #1” and “allocation device #2” notifies the allocation control unit33of the completion of the wavelength allocation (step S611).

Second Modified Example

Note that a part or all of the respective functional units provided in the management control device3may be provided in the distributed station2. For example, the collection unit31and the analysis unit32may be provided in the distributed station2in place of the management control device3.

Third Modified Example

Note that, in the allocation device4, it is not always necessary that each allocation device4exists in each of the distributed stations2, and one allocation device4may be provided for each of the plurality of distributed stations2.

FIG.9is a diagram showing an example of a configuration of the communication system100aaccording to the third modified example. Hereinafter, for the sake of simplicity of description, functional units having the same functions as those included in the communication system100are denoted by the same reference numerals as those inFIG.1, and description thereof is omitted. The communication system100ais different from the communication system100in that the distributed station2and the allocation device4do not have a one-to-one relationship but have an N-to-one relationship (N is an integer of 2 or more). The relationship between the allocation device4and the aggregation station5in the communication system100ais different from the communication system100and has a one-to-one relationship. Therefore, in the communication system100a, the relationship between the allocation device4and the aggregation station5is not changed regardless of the content of wavelength allocation.

FIG.10is a first sequence diagram showing an example of a flow of processing executed by the communication system100aof the third modified example. More specifically,FIG.10is a sequence diagram showing an example of a flow of processing executed by the communication system100a, as an example, in a case where the cooperation information indicates the average throughput of the terminals900and the number of active terminals900for each cell.

In addition,FIG.10shows an example of a flow of processing executed by the communication system100a, as an example, in a case where the result of the judgement as to whether or not to execute the wavelength allocation by the wavelength control judgement unit323is a result of executing the wavelength allocation.

“Distributed station #1” means one of the distributed stations2provided in the communication system100a, and “distributed station #2” is one of the distributed stations provided in the communication system100aand means another distributed station2which is different from “distributed station #1”.

Information indicating the number of active terminals900for each cell is transmitted from the wireless station1to the management control device3(step S701). Next, information indicating the average throughput of the terminals900is transmitted from the wireless station1to the management control device3(step S702). For the processing of step S701and the processing of step S702, any one may be executed before the other one.

Next, the wavelength control judgement unit323judges whether or not to execute the wavelength allocation on the basis of the cooperation information obtained in the step S701and the step S702(step S703). Next, the allocation control unit33transmits the wavelength allocation notification to the distributed station #1, the distributed station #2and the aggregation station5(step S704).

Next, the distributed station #1, the distributed station #2and the aggregation station5transmit the wavelength allocation response notification to the allocation control unit33(step S705). The wavelength allocation response notification is information indicating that the wavelength allocation notification has been received.

Next, the allocation control unit33notifies the distributed station #1, the distributed station #2and the aggregation station5of the start time of communication after the wavelength allocation (step S706). Next, the distributed station #1, the distributed station #2and the aggregation station5return the response to the notification of the start time of communication after the wavelength allocation to the allocation control unit33(step S707).

Next, the allocation control unit33transmits the wavelength control information to the allocation device4(step S708). Next, the allocation control unit33notifies the distributed station #1, the distributed station #2and the aggregation station5of the start of wavelength allocation (step S709). Next, the allocation device4notifies the allocation control unit33of the completion of the wavelength allocation (step S710). Next, the distributed station #1, the distributed station #2and the aggregation station5notify the allocation control unit33of the completion of the wavelength allocation (step S711).

Note that it is not always necessary to execute processing of step S705. In this way, even when there is no response after the allocation control unit33transmits the wavelength allocation notification, processing after the step S706is executed. Note that the processing of step S708may be executed before the processing of step S707.

In a flowchart ofFIG.10, the management control device3notifies the distributed station2and the aggregation station5. However, it is not always necessary to transmit the notification from the management control device3to the distributed station2and the aggregation station5. The notification may be transmitted from the allocation device4to the distributed station2and the aggregation station5, for example.FIG.11shows a second sequence diagram showing an example of a flow of processing executed by the communication system100aof such a case.

FIG.11is a second sequence diagram showing an example of a flow of processing executed by the communication system100aof the third modified example. More specifically,FIG.11is a sequence diagram showing an example of a flow of processing executed by the communication system100a, as an example, in a case where the cooperation information indicates the average throughput of the terminals900and the number of active terminals900for each cell.

In addition,FIG.11shows an example of a flow of processing executed by the communication system100a, as an example, in a case where the result of the judgement as to whether or not to execute the wavelength allocation by the wavelength control judgement unit323is a result of executing the wavelength allocation.

Information indicating the number of active terminals900for each cell is transmitted from the wireless station1to the management control device3(step S801). Next, information indicating the average throughput of the terminals900is transmitted from the wireless station1to the management control device3(step S802). For the processing of step S801and the processing of step S802, any one may be executed before the other one.

Next, the wavelength control judgement unit323judges whether or not to execute the wavelength allocation on the basis of the cooperation information obtained in the step S801and the step S802(step S803). Next, the allocation control unit33transmits the wavelength control information to the allocation device4(step S804).

Next, the allocation device4transmits the wavelength allocation notification to the distributed station #1, the distributed station #2and the aggregation station5(step S805). Next, the distributed station #1, the distributed station #2and the aggregation station5transmit the wavelength allocation response notification to the allocation device4(step S806).

Next, the allocation device4notifies the distributed station #1, the distributed station #2and the aggregation station5of the start time of communication after the wavelength allocation (step S807). Next, the distributed station #1, the distributed station #2and the aggregation station5return the response to the notification of the start time of communication after the wavelength allocation to the allocation device4(step S808).

Next, the allocation device4notifies the distributed station #1, the distributed station #2and the aggregation station5of the start of wavelength allocation (step S809). Next, the distributed station #1, the distributed station #2and the aggregation station5notify the allocation device4of the completion of the wavelength allocation (step S810). Next, the allocation device4notifies the allocation control unit33of the completion of the wavelength allocation (step S811).

FIG.12is a diagram showing a hardware configuration example of the management control device3according to each embodiment and each modified example. A part or all of each functional unit of the management control device3are realized as software by causing a processor301such as a CPU (Central Processing Unit) to execute a program stored in a storage device302and a storage unit303including a non-volatile recording medium (non-transitory recording medium). The program may be recorded in the non-transitory recording medium that is computer-readable. Examples of the non-transitory recording medium that is computer-readable include a portable medium such as a flexible disc, a magneto-optical disc, a ROM (Read Only Memory), or a CD-ROM (Compact Disc Read Only Memory), and a non-transitory recording medium such as a storage device including a hard disk incorporated in a computer system. A communication unit304executes predetermined communication processing. The communication unit304may acquire data and a program.

A part or all of each functional unit of the management control device3may be realized using hardware including an electronic circuit or circuitry in which an LSI (Large Scale Integrated circuit), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), an FPGA (Field Programmable Gate Array), or the like is used.

FIG.13is a diagram showing a hardware configuration example of the allocation device4according to each embodiment and each modified example. A part or all of each functional unit of the allocation device4are realized as software by causing a processor401such as the CPU to execute the program stored in a storage device402and a storage unit403including the non-volatile recording medium (non-transitory recording medium). The program may be recorded in the non-transitory recording medium that is computer-readable. Examples of the non-transitory recording medium that is computer-readable include the portable medium such as the flexible disc, the magneto-optical disc, the ROM, or the CD-ROM, and the non-transitory recording medium such as the storage device including the hard disk incorporated in the computer system. The communication unit404executes the predetermined communication processing. The communication unit404may acquire the data and the program.

A part or all of each functional units of the allocation device4may be realized using hardware including an electronic circuit or circuitry in which the LSI, the ASIC, the PLD, the FPGA, or the like is used.

FIG.14is a diagram showing a hardware configuration example of the distributed station2according to each embodiment and each modified example. A part or all of each functional unit of the distributed station2are realized as software by causing a processor201such as the CPU to execute a program stored in a storage device202or a storage unit203including the nonvolatile recording medium (non-transitory recording medium). The program may be recorded in the non-transitory recording medium that is computer-readable. Examples of the non-transitory recording medium that is computer-readable include the portable medium such as the flexible disc, the magneto-optical disc, the ROM, or the CD-ROM, and the non-transitory recording medium such as the storage device including the hard disk incorporated in the computer system. A communication unit204executes the predetermined communication processing. The communication unit204may acquire the data and the program.

A part or all of each functional unit of the distributed station2may be realized using hardware including the electronic circuit or circuitry in which the LSI, the ASIC, the PLD, the FPGA, or the like is used.

Each of the distributed station2, the management control device3and the allocation device4may be implemented by using a plurality of information processing devices communicatively connected via a network. In this case, each functional unit included in each of the distributed station2, the management control device3and the allocation device4may be distributed and implemented in the plurality of information processing devices.

Each embodiment may be combined.

Although the above embodiment of the present invention has been described in detail with reference to the drawings, a specific configuration is not limited to these embodiments, and design within the scope of the gist of the present invention, and the like are included.

INDUSTRIAL APPLICABILITY

The present invention is applicable to optical communication systems such as optical access systems.

REFERENCE SIGNS LIST