Pre-switching control device, pre-switching control method, and pre-switching control program

Abstract

In this pre-switching control device, a communication use status DB unit includes: an information holding unit that acquires and holds communication use status information of each subject ONU of an automatic switching system and event information of an online event in which burst traffic occurs; and a switching determination information calculation unit that calculates switching determination information of each ONU from the use bandwidth information of each ONU and the event information. A switching optimization unit acquires communication use status information from the communication use status DB unit and selects an optical SW to be switched.

Description

Pre-switching control device, pre-switching control method, and pre-switching control program

[0001] The present invention relates to a pre-switching control device, a pre-switching control method, and a pre-switching control program.

[0002] In a PON (Passive Optical Network) configuration consisting of an OLT (Optical Line Terminal) and an ONU (Optical Network Unit), an optical SW (optical switch) is inserted between the OLT and the ONU, and the OLT that accommodates the ONU is periodically switched depending on the current communication usage status, thereby making effective use of the bandwidth of the PON section.

[0003] Japanese Patent Application Publication No. 2012-19353

[0004] When an online event such as a major software update or the release of event information occurs, burst traffic occurs for certain users, which can cause communication to become unstable under the control of the OLT in question between the event occurrence and automatic switching.

[0005] The present invention has been made in view of the above circumstances, and has as its object to provide stable communications to users even when burst traffic occurs.

[0006] One aspect of the present invention is a pre-switching control device. In the pre-switching control device, a communication usage status DB unit has an information storage unit that acquires and stores communication usage status information of each ONU that is a target of the automatic switching system and event information of an online event that generates burst traffic, and a switching judgment information calculation unit that calculates switching judgment information for each ONU from the usage bandwidth information and event information of each ONU. A switching optimization unit acquires the communication usage status information from the communication usage status DB unit and selects an optical SW to be switched.

[0007] One aspect of the present invention is a pre-switching control method, which includes the steps of acquiring and retaining communication usage status information of each ONU that is a target of an automatic switching system and event information of an online event that generates burst traffic, calculating switching determination information for each ONU from the usage bandwidth information and event information of each ONU, and acquiring the communication usage status information and selecting an optical SW to be switched.

[0008] One aspect of the present invention is a pre-switching control program that causes a computer having a processor and a storage device to execute at least some of the functions of the components of the pre-switching control device.

[0009] According to the present invention, stable communication can be provided to users even when burst traffic occurs.

[0010] FIG. 1 is a block diagram showing an automatic switching system partially including a pre-switching control device according to an embodiment. FIG. 2 is a flowchart showing the flow of a calculation process for switching determination information executed by a communication usage status DB unit. FIG. 3 is a flowchart showing the flow of a response process for switching determination information executed by the communication usage status DB unit. FIG. 4 is a flowchart showing the flow of a switching optimization process executed by a switching optimization unit. FIG. 5 is a flowchart showing the flow of a calculation process for switching determination information executed by the communication usage status DB unit. FIG. 6 is a diagram showing information held by the communication usage status DB unit. FIG. 7 is a flowchart showing the flow of a response process for switching determination information executed by the communication usage status DB unit. FIG. 8 is a diagram showing information held by the communication usage status DB unit. FIG. 9 is a flowchart showing the flow of a switching optimization process executed by the switching optimization unit. FIG. 10 is a diagram showing an example of OLT information, SW information, switching determination information (coefficient) averages, and emergency call usage. FIG. 11 is a block diagram showing the hardware configuration of a computer constituting the pre-switching control device.

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] (Automatic Switching System) First, an automatic switching system 20 that partially includes a pre-switching control device 30 according to an embodiment will be described with reference to Fig. 1. Fig. 1 is a block diagram illustrating the automatic switching system 20 that partially includes a pre-switching control device 30 according to an embodiment.

[0013] The automatic switching system 20 includes a host IF function unit 21, a business AP unit 22, and a downstream IF function unit 24. The business AP unit 22 includes a switching control unit 23 and a switching optimization unit 50.

[0014] The upper IF function unit 21 functions as an interface with the upper host 10. The lower IF function unit 24 functions as an interface with the lower PON.

[0015] The host 10 transmits an automatic switching request to the automatic switching system 20 at regular time intervals. When the switching control unit 23 of the business AP unit 22 receives the automatic switching request, it queries the switching optimization unit 50 about the necessity of switching and the target optical SW. In response to the query about the necessity of switching and the target optical SW, the switching optimization unit 50 returns information about the necessity of switching and the target optical SW to the switching control unit 23. The switching control unit 23 controls the switching of the optical SW of the PON based on the information about the necessity of switching and the target optical SW. If switching is not required, the switching control unit 23 transmits information that switching is not required to the host 10. If switching is required, the switching control unit 23 transmits a switching instruction to the PON. The PON switches the optical SW in accordance with the switching instruction and transmits the switching result to the switching control unit 23. The switching control unit 23 transmits the received information about the switching result to the host 10.

[0016] The pre-switching control device 30 includes a communication usage status DB unit 40 and a switching optimization unit 50. The switching optimization unit 50 is included in the automatic switching system 20.

[0017] The communication usage status DB unit 40 includes an information holding unit 41 , a switching determination information calculation unit 42 , and a response unit 43 .

[0018] The information holding unit 41 acquires and holds various information. For example, the information holding unit 41 periodically acquires and holds information on the bandwidth used by each ONU from the automatic switching system 20. In other words, the information holding unit 41 holds information on the current and past bandwidth used by each ONU, i.e., the history of the bandwidth usage status. The information holding unit 41 also acquires and holds information on the current emergency call usage status of each ONU from the automatic switching system 20.

[0019] The information storage unit 41 also acquires and stores event information about online events that generate burst traffic from an external source such as the Internet. Examples of online events include major software updates and event releases. The event information includes the name, attributes, and start and end dates and times of the online event. The attributes of the online event include classification information such as OS updates, games, sports, entertainment, politics, etc.

[0020] The switching decision information calculation unit 42 calculates switching decision information (coefficients) for each ONU based on changes in bandwidth usage status accompanying the occurrence of past online events, from the bandwidth usage information and event information for each ONU. The information storage unit 41 also acquires and stores the switching decision information (coefficients) for each ONU.

[0021] The response unit 43 returns response information in response to an inquiry from the switching optimization unit 50 about whether switching is necessary.

[0022] When receiving an automatic switching request, the switching optimization unit 50 calculates whether switching is necessary and the target optical SW based on the switching decision information of each ONU linked to a future online event or the current bandwidth usage status.

[0023] (Calculation of Switching Determination Information) The calculation process of switching determination information executed by the communication utilization status DB unit 40 will be described with reference to Fig. 2. Fig. 2 is a flowchart showing the flow of the calculation process of switching determination information executed by the communication utilization status DB unit 40.

[0024] In step S11, the communication usage status DB unit 40 receives the bandwidth usage information of each ONU from the automatic switching system 20. The information holding unit 41 holds the bandwidth usage information of each ONU.

[0025] In step S12 , the switching determination information calculation unit 42 calculates a change in the current bandwidth usage status of each ONU based on the bandwidth usage information of each ONU stored in the information storage unit 41 .

[0026] In step S13, the switching determination information calculation unit 42 compares the change in the current bandwidth usage status of each ONU calculated in step S12 with the reference value of the change in the bandwidth usage status of each ONU stored in the information storage unit 41.

[0027] If the result of the comparison in step S13 is that the change in the current bandwidth usage status is smaller than the reference value, the switching determination information calculation unit 42 ends the calculation process of the switching determination information.

[0028] If the comparison result in step S13 indicates that the change in the current bandwidth usage status is equal to or greater than the reference value, then in step S14, the switching judgment information calculation unit 42 determines whether the change in the current bandwidth usage status is due to the occurrence of an online event and whether there is a correlation with the online event.

[0029] In step S15, the switching determination information calculation unit 42 reflects the correlation determination result in the ONU switching determination information (coefficient) set for each ONU.

[0030] (Response to Switching Determination Information) Next, a response process to switching determination information executed by the communication utilization status DB unit 40 will be described with reference to Fig. 3. Fig. 3 is a flowchart showing the flow of the response process to switching determination information executed by the communication utilization status DB unit 40.

[0031] When the switching optimization unit 50 receives the automatic switching request, it sends a switching necessity inquiry to the communication usage status DB unit 40 .

[0032] In step S21, the communication usage status DB unit 40 receives a query about whether or not switching is necessary from the switching optimization unit 50.

[0033] In step S22, the response unit 43 compares the current time, the next switching time, and the date and time of the online event.

[0034] In step S23, the response unit 43 determines whether an online event will occur before the next automatic switching request is received.

[0035] If the result of the judgment in step S23 is that an online event will occur before the next automatic switching request is received, in step S24, the response unit 43 returns to the switching optimization unit 50 response information, such as event "occurrence," "switching judgment information (coefficient)," and bandwidth information for each ONU.

[0036] If the result of the judgment in step S23 is that no online event occurs before the next automatic switching request is received, in step S25, the response unit 43 returns response information to the switching optimization unit 50, including ``no event'' and bandwidth information for each ONU.

[0037] (Switching Optimization Algorithm) Next, the switching optimization process executed by the switching optimization unit 50 will be described with reference to Fig. 4. Fig. 4 is a flowchart showing the flow of the switching optimization process executed by the switching optimization unit 50.

[0038] In step S31, the switching control unit 23 of the automatic switching system 20 receives an automatic switching request from the host 10, and in step S32, sends a switching necessity / target light SW inquiry to the switching optimization unit 50.

[0039] When the switching optimization unit 50 receives the switching necessity / target optical SW inquiry, it transmits the switching necessity inquiry to the communication usage status DB unit 40, and in step S33, the switching optimization unit 50 acquires communication usage status information from the communication usage status DB unit 40. The communication usage status information includes whether or not there is an online event until the next switching request, switching determination information (coefficient) for each ONU, the current bandwidth usage status of each ONU, and the current emergency call usage status of each ONU.

[0040] In step S34, the switching optimization unit 50 determines whether an online event will occur before the next automatic switching request is received.

[0041] If the result of the determination in step S34 is that an online event will occur before the next automatic switching request is received, the switching optimization unit 50 determines in step S35 whether there is an ONU that requires switching due to an online event.

[0042] If the result of the determination in step S35 is that there is an ONU that requires switching due to an online event, the switching optimization unit 50 selects switching pattern (1) in step S36. Switching pattern (1) is a switching pattern for determining whether switching is necessary and selecting an optical switch based on event information for a future online event.

[0043] If the result of the determination in step S35 is that there is no ONU that requires switching due to an online event, or if the result of the determination in step S34 is that no online event will occur before the next automatic switching request is received, the switching optimization unit 50 selects switching pattern (2) in step S37. Switching pattern (2) is a switching pattern for determining whether switching is necessary and selecting an optical SW based on the current bandwidth usage status.

[0044] In step S38, the switching optimization unit 50 returns the selected switching pattern (1) or (2) to the switching control unit 23.

[0045] The switching control unit 23 performs switching control in accordance with the received switching pattern (1) or (2). If switching is not required, the switching control unit 23 transmits information indicating that switching is not required to the host 10. If switching is required, the switching control unit 23 transmits switching instructions to OLT#1 and OLT#2. OLT#1 and OLT#2 switch between optical SW#1 and optical SW#2 in accordance with the received switching instruction and transmit the switching result to the switching control unit 23. The switching control unit 23 transmits the received switching result to the host 10.

[0046] (Example) Hereinafter, an example of the operation of a pre-switching control device according to an example will be described with reference to Figs.

[0047] (Calculation of Switching Determination Information) First, the calculation process of switching determination information executed by the communication usage status DB unit 40 will be described with reference to Fig. 5 and Fig. 6. Fig. 5 is a flowchart showing the flow of the calculation process of switching determination information executed by the communication usage status DB unit 40. Fig. 6 is a diagram showing information held by the communication usage status DB unit 40.

[0048] As shown in FIG. 6 , the information storage unit 41 of the communication usage status DB unit 40 stores a table (top row) of event information and date and time. The event information includes the name of the event and the attributes of the event. The date and time include information on the start date and time and the end date and time. The information storage unit 41 also stores a table (middle row) of event information (attributes) and correlation determination time t. The correlation determination time t is set for each attribute of the event information. The information storage unit 41 also stores a table (bottom row) of event attributes, OLT information, SW information, ONU information, and switching determination information (coefficients). The OLT information, SW information, ONU information, and switching determination information (coefficients) are stored for each attribute of the event information. That is, the OLT information, SW information, ONU information, and switching determination information (coefficients) are stored for each ONU as three types of numerical values: "software release," "politics," and "sports."

[0049] In step S41, the communication usage status DB unit 40 receives the bandwidth usage information of each ONU from the automatic switching system 20. The information holding unit 41 holds the bandwidth usage information of each ONU.

[0050] In step S42, the switching determination information calculation unit 42 calculates a change in the current bandwidth usage status of each ONU based on the bandwidth usage information of each ONU held in the information holding unit 41.

[0051] In step S43, the switching determination information calculation unit 42 compares the change in the current bandwidth usage status of each ONU calculated in step S42 with a reference value for the change in the bandwidth usage status of each ONU stored in the information storage unit 41. In this embodiment, the reference value is set to 20% of the maximum bandwidth that the OLT can provide. In other words, the switching determination information calculation unit 42 determines whether the bandwidth used by the OLT has increased by 20% or more. The reference value can be changed to an appropriate value depending on the actual changes in the bandwidth used.

[0052] If the result of the comparison in step S43 indicates that the increase in bandwidth usage is less than 20%, the switching determination information calculation unit 42 ends the process of calculating the switching determination information.

[0053] If the comparison result in step S43 indicates that the increase in bandwidth usage is 20% or more, then in step S43, the switching determination information calculation unit 42 determines whether the change in the current bandwidth usage status is caused by the occurrence of an online event and determines a correlation with the online event. Specifically, the switching determination information calculation unit 42 references a table of event information (attributes) and correlation determination time t (middle section of FIG. 6 ) and obtains a correlation determination time t corresponding to the attribute of the event information. Next, the switching determination information calculation unit 42 determines that there is a correlation if the change in the current bandwidth usage status has occurred within t minutes. Conversely, the switching determination information calculation unit 42 determines that there is no correlation if the change in the current bandwidth usage status has not occurred within t minutes.

[0054] The switching determination information calculation unit 42 reflects the determination result in the switching determination information (coefficient) set for each ONU for each attribute in steps S45 and S46. In this embodiment, the switching determination information (coefficient) is k (0≦k≦1).

[0055] If the result of the determination in step S44 is that there is no correlation, in step S45, the switching determination information calculation unit 42 updates the switching determination information (coefficient) held in the information holding unit 41 by setting k=k-0.1.

[0056] If the result of the determination in step S44 is that there is a correlation, in step S46, the switching determination information calculation unit 42 updates the switching determination information (coefficient) held in the information holding unit 41 by setting k=k+0.1.

[0057] (Response to Switching Determination Information) Next, the response process to switching determination information executed by the communication usage status DB unit 40 will be described with reference to Fig. 7 and Fig. 8. Fig. 7 is a flowchart showing the flow of the response process to switching determination information executed by the communication usage status DB unit 40. Fig. 8 is a diagram showing information held by the communication usage status DB unit 40. Details of the information shown in Fig. 8 are as described with reference to Fig. 6.

[0058] When the switching optimization unit 50 receives the automatic switching request, it sends a switching necessity inquiry to the communication usage status DB unit 40 .

[0059] In step S51, the communication usage status DB unit 40 receives a query about whether or not switching is necessary from the switching optimization unit 50.

[0060] In step S52, the response unit 43 compares the current time, the next switching time, and the date and time of the online event.

[0061] In step S53, the response unit 43 determines whether an online event will occur before the next automatic switching request is received.

[0062] If the result of the judgment in step S53 is that an online event will occur before the next automatic switching request is received, in step S54, the response unit 43 returns to the switching optimization unit 50 a message indicating that an event has occurred, the switching decision information (coefficient) for each ONU, the current bandwidth usage status of each ONU, and the current emergency call usage status of each ONU.

[0063] If the result of the judgment in step S53 is that no online event will occur before the next automatic switching request is received, in step S55, the response unit 43 returns to the switching optimization unit 50 a message indicating "no event," the current bandwidth usage status of each ONU, and the current emergency call usage status of each ONU.

[0064] In this embodiment, the switching request is received at 60-minute intervals, at 15 minutes past the hour. For example, as shown in FIG. 8 (top row), the current time is 2023 / 03 / 14 / 21:15, and the next automatic switching request is 2023 / 03 / 14 / 22:15. The start time of "Event A" is 2023 / 03 / 14 / 22:00. Therefore, "Event A" will occur before the next automatic switching request is received. Therefore, the responding unit 43 returns to the switching optimization unit 50 the event "occurred" and the numerical values ​​in the boxes in FIG. 8 (bottom row) as the switching determination information (coefficients) for each ONU, etc.

[0065] The switching request time and request interval can be changed depending on the situation.

[0066] (Switching Optimization Algorithm) Next, the switching optimization process executed by the switching optimization unit 50 will be described with reference to Fig. 9 and Fig. 10. Fig. 9 is a flowchart showing the flow of the switching optimization process executed by the switching optimization unit 50.

[0067] In step S61, the switching control unit 23 of the automatic switching system 20 receives an automatic switching request from the host 10, and in step S62, sends a switching necessity / target light SW inquiry to the switching optimization unit 50.

[0068] When the switching optimization unit 50 receives the switching necessity / target optical SW inquiry, it transmits the switching necessity inquiry to the communication usage status DB unit 40, and in step S63, the switching optimization unit 50 acquires communication usage status information from the communication usage status DB unit 40. The communication usage status information includes whether or not there is an online event until the next switching request, switching determination information (coefficient) for each ONU, the current bandwidth usage status of each ONU, and the current emergency call usage status of each ONU.

[0069] In this implementation example, among the optical SWs that do not use emergency calls, the optical SW with the largest switching judgment information (coefficient) and the optical SW with the smallest switching judgment information (coefficient) that is 0.5 or less are selected as the switching targets.

[0070] In step S64, the switching optimization unit 50 determines whether an online event will occur before the next automatic switching request is received.

[0071] If the result of the determination in step S64 is that an online event will occur before the next automatic switching request is received, in step S65 the switching optimization unit 50 determines whether there are any ONUs that require switching due to the online event. In this embodiment, the switching optimization unit 50 determines that switching is necessary if the average of the switching determination information (coefficient) of ONUs under the same SW is greater than a threshold value of 0.5. The threshold value can be changed to an appropriate value depending on the actual bandwidth usage.

[0072] If the result of the determination in step S65 is that there is an ONU that requires switching due to an online event, the switching optimization unit 50 selects switching pattern (1) in step S66. Switching pattern (1) is a switching pattern for determining whether switching is necessary and selecting an optical SW based on event information for a future online event.

[0073] In step S67, the switching optimization unit 50 selects "optical SW (A) that is not used for emergency calls and has the largest switching determination information (coefficient)" under the control of the 8SP.

[0074] In the selection of step S67, if there is an ONU that corresponds to optical SW (A), in step S68, the switching optimization unit 50 selects "optical SW (B) that is not used for emergency calls and has the smallest switching judgment information (coefficient)" under the control of 8SP.

[0075] In the selection of step S68, if there is an ONU corresponding to the optical SW (B), in step S69, the switching optimization unit 50 selects the optical SW (A) and the optical SW (B) as switching targets.

[0076] In the selection of step S68, if there is an ONU corresponding to the optical SW (B), in step S69, the switching optimization unit 50 selects the optical SW (A) and the optical SW (B) as switching targets.

[0077] If there is no ONU corresponding to the optical SW (B) in the selection of step S68, if there is no ONU corresponding to the optical SW (A) in the selection of step S67, or if the result of the determination in step S64 is that no online event will occur before the next automatic switching request is received, the switching optimization unit 50 selects switching pattern (2) in step S70. Switching pattern (2) is a switching pattern for determining whether switching is necessary and selecting an optical SW based on the current bandwidth usage status.

[0078] In step S71, the switching optimization unit 50 returns the selected switching pattern (1) or (2) to the switching control unit 23.

[0079] The switching control unit 23 performs switching control in accordance with the received switching pattern (1) or (2). If switching is not required, the switching control unit 23 transmits information indicating that switching is not required to the host 10. If switching is required, the switching control unit 23 transmits switching instructions to OLT#1 and OLT#2. OLT#1 and OLT#2 switch between optical SW#1 and optical SW#2 in accordance with the received switching instruction and transmit the switching result to the switching control unit 23. The switching control unit 23 transmits the received switching result to the host 10.

[0080] 10 is a diagram showing an example of OLT information, SW information, average switching decision information (coefficient), and emergency call usage. In the example of FIG. 10, two optical SWs enclosed in a frame, i.e., optical SW #4 of OLT #1 and optical SW #1 of OLT #2, are selected as switching targets. Optical SW #4 of OLT #1 corresponds to "optical SW (A) with no emergency call usage and the largest switching decision information (coefficient)," and optical SW #1 of OLT #2 corresponds to "optical SW (B) with no emergency call usage and the smallest switching decision information (coefficient)."

[0081] (Hardware Configuration) For example, the pre-switching control device 30 is configured by a computer. In other words, both the communication usage status DB unit 40 and the switching optimization unit 50 are configured by computers. Hereinafter, the hardware configuration of a computer 60 that can configure the pre-switching control device 30 will be described with reference to Fig. 11. Fig. 11 is a block diagram showing the hardware configuration of the computer 60 that configures the pre-switching control device 30.

[0082] The computer 60 includes a processor 61 , a read-only memory (ROM) 62 , a random access memory (RAM) 63 , an auxiliary storage device 64 , an input / output interface (IF) 65 , and a communication interface (IF) 66 .

[0083] The processor 61 , ROM 62 , RAM 63 , auxiliary storage device 64 , input / output IF 65 and communication IF 66 are electrically connected to one another via a bus 67 , and can transmit and receive data to and from one another via the bus 67 .

[0084] The processor 61 is configured by a general-purpose hardware processor including, for example, a CPU (Central Processing Unit), a GPU (Graphical Processing Unit), etc. The processor 61 controls the ROM 62, the RAM 63, the auxiliary storage device 64, and the input / output IF 65 as a whole.

[0085] The ROM 62 is a non-volatile memory that constitutes part of the main storage device. The ROM 62 non-temporarily stores a startup program required when the processor 61 is started. The processor 61 starts up by executing the program in the ROM 62. The ROM 62 is configured, for example, by an EPROM (Erasable Programmable Read Only Memory), and stores various startup settings in addition to the startup program.

[0086] The RAM 63 is a volatile memory that constitutes part of the main storage device. The RAM 63 temporarily stores programs required for processing by the processor 61 and data required for executing the programs. The processor 61 executes the programs in the RAM 63 to perform operations on the data in the RAM 63 and store the results of the operations in the RAM 63.

[0087] The auxiliary storage device 64 is configured by a non-volatile memory such as an HDD (Hard Disk Drive) or an SSD (Solid State Drive). The auxiliary storage device 64 non-temporarily stores programs to be executed by the processor 61 and data required for executing the programs. The processor 61 loads the programs and data in the auxiliary storage device 64 into the RAM 63 and executes the programs to perform various functions.

[0088] The input / output IF 65 is connected to the input / output device 71 and the like, and enables input and output of information. For example, the input / output device 71 and the like may include a keyboard, a mouse, a touch panel, a receiving device, a disk drive, etc. The input / output device 71 is not limited to these, and may include any other input device.

[0089] The program non-temporarily stored in the auxiliary storage device 64 is provided to the computer 60, for example, via a recording medium 72 on which the program is non-temporarily recorded and which can be read by the computer 60. Such a recording medium 72 is called a non-temporarily computer-readable recording medium. Non-temporarily computer-readable recording media include disks such as flexible disks, optical disks (CD-ROM, CD-R, DVD-ROM, DVD-R, etc.), and magneto-optical disks (MO, etc.), as well as semiconductor memories.

[0090] The communication IF 66 enables input and output of information, and includes Bluetooth (registered trademark), Wi-Fi (registered trademark), and the like.

[0091] The programs non-temporarily stored in the auxiliary storage device 64 include a pre-switching control program. The pre-switching control program is a program that causes the computer 60 to execute at least some of the functions of the pre-switching control device 30.

[0092] For example, if the recording medium 72 is a disk, the program non-temporarily stored in the auxiliary storage device 64 is read into the auxiliary storage device 64 via the disk drive serving as the input / output device 71 and the input / output IF 65 and non-temporarily stored therein. Alternatively, the program may be stored in a server on a network, downloaded from the server, and non-temporarily stored in the auxiliary storage device 64.

[0093] When the computer 60 starts up, the processor 61 executes a program in the ROM 62 and loads and starts the OS into the RAM 63. Under control of the OS, the processor 61 monitors input instructions, connections to external devices, and the like. Under control of the OS, the processor 61 also sets up a program area and a data area in the RAM 63. In response to a start instruction input for the pre-switching control device 30, the processor 61 loads the pre-switching control program from the auxiliary storage device 64 into the program area of ​​the RAM 63, and loads data required for executing the pre-switching control program from the auxiliary storage device 64 into the data area of ​​the RAM 63. The processor 61 calculates data in the data area according to the pre-switching control program and writes the calculation results to the data area. Through these operations, the processor 61, RAM 63, auxiliary storage device 64, input / output IF 65, and bus 67 work together to execute at least some of the functions of the pre-switching control device 30.

[0094] (Effects) As described above, when an automatic switching request is received, the pre-switching control device 30 according to the embodiment provides the automatic switching system 20 with switching pattern (1) for determining whether switching is necessary and selecting an optical SW based on event information about a future online event if an online event will occur between now and the next time an automatic switching request is received, or with switching pattern (2) for determining whether switching is necessary and selecting an optical SW based on the current bandwidth usage status if no online event will occur. If switching is necessary, the automatic switching system 20 switches the optical SW in advance before the online event occurs. This makes it possible to provide stable communications to users even when burst traffic occurs.

[0095] The present invention is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the invention. Furthermore, the embodiments may be implemented in appropriate combinations, in which case the combined effects can be obtained. Furthermore, the above-described embodiments include various inventions, and various inventions can be extracted by combining selected elements from the disclosed elements. For example, if the problem can be solved and the desired effect can be obtained even if some elements are deleted from all elements shown in the embodiments, the configuration from which these elements are deleted can be extracted as an invention.

[0096] DESCRIPTION OF SYMBOLS 10... Host 20... Automatic switching system 21... Upper IF function unit 22... Business AP unit 23... Switching control unit 24... Lower IF function unit 30... Pre-switching control device 40... Communication usage status DB unit 41... Information storage unit 42... Switching determination information calculation unit 43... Response unit 50... Switching optimization unit 60... Computer 61... Processor 62... ROM 63... RAM 64... Auxiliary storage device 67... Bus 71... Input / output device 72... Recording medium 65... Input / output IF 66... ​​Communication IF

Claims

1. A pre-switching control device having a communication usage status DB unit having an information storage unit that acquires and stores communication usage status information of each ONU that is the target of an automatic switching system and event information of online events in which burst traffic occurs, and a switching judgment information calculation unit that calculates switching judgment information for each ONU from the utilization bandwidth information of each ONU and the event information, and a switching optimization unit that acquires the communication usage status information from the communication usage status DB unit and selects an optical SW to be switched.

2. The pre-switching control device of claim 1, wherein the switching judgment information calculation unit calculates a change in the bandwidth usage status of each ONU, compares the change in the bandwidth usage status of each ONU with a reference value, and if the change in the bandwidth usage status of each ONU is equal to or greater than the reference value, determines a correlation with the online event, and reflects the determination result in the switching judgment information.

3. The pre-switching control device according to claim 2, wherein the switching judgment information calculation unit determines whether the OLT's bandwidth usage has increased by 20% or more, and if the increase in bandwidth usage is 20% or more, obtains a correlation judgment time according to the attributes of the online event, and determines that there is a correlation if a change in each ONU occurs within the correlation judgment time.

4. The pre-switching control device as described in claim 2, wherein the communication usage status DB unit has a response unit which responds to an inquiry from the switching optimization unit as to whether switching is necessary, and the response unit compares the current time, the next switching time, and the start date and time of the online event to determine whether the online event will occur before receiving the next automatic switching request, and if the online event will occur, returns information on the occurrence of the online event, bandwidth usage information of each ONU, and switching judgment information to the switching optimization unit, and if the online event will not occur, returns information on the absence of the online event and bandwidth usage information of each ONU to the switching optimization unit.

5. In response to a query from the automatic switching system regarding the necessity of switching and the target optical SW, the switching optimization unit obtains from the communication usage status DB unit information on whether the online event has occurred, switching decision information for each ONU, current and past bandwidth usage information for each ONU, and current emergency call usage status for each ONU, and determines whether the online event will occur before the next automatic switching request is received; if the online event will occur, determines whether there are any ONUs that require switching due to the online event; if there are ONUs that require switching, selects whether or not switching is required and an optical SW based on information about the future online event; and if there are no ONUs that require switching or if the online event has not occurred, selects whether or not switching is required and an optical SW based on the current bandwidth usage status. The pre-switching control device described in claim 4.

6. The pre-switching control device according to claim 5, wherein the switching optimization unit determines whether there is an optical SW whose average of the switching judgment information is greater than a threshold value, and if there is an optical SW whose average of the switching judgment information is greater than the threshold value, selects as switching targets a first optical SW that is not used for emergency calls and has the greatest switching judgment information, and a second optical SW that is not used for emergency calls and has the smallest switching judgment information.

7. A pre-switching control method comprising the steps of: acquiring and retaining communication usage status information of each ONU targeted by an automatic switching system and event information of an online event in which burst traffic occurs; calculating switching decision information for each ONU from the bandwidth usage information of each ONU and the event information; and acquiring the communication usage status information and selecting an optical SW to be switched.

8. A pre-switching control program that causes a computer having a processor and a storage device to execute at least some of the functions of the components of the pre-switching control device according to any one of claims 1 to 6.

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