Control device, communication control system, and control method

Abstract

Provided is a control device for transmitting an instruction to switch a route configuration to a controlled device that transfers communication data between terminals, the control device comprising: a transmission timing determination unit that determines, on the basis of a difference in transmission delay time between the controlled devices, a timing at which to transmit a route configuration switching instruction to the controlled device; and a route configuration control unit that transmits a route configuration switching instruction to the controlled device at the determined timing.

Description

Control device, communication control system, and control method

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

[0002] In conventional optical communication systems, when a device that relays communication between terminals switches route settings, the timing of the switch does not take into account the propagation time of the communication data, resulting in a problem of longer time required for communication data to be transmitted between terminals.

[0003] Hiroshi Ou, “First Demonstration of Real-Time Optical Path Control Scheme with AMCC Telemetry”, European Conference on Optical Communication (ECOC) 2022.

[0004] In view of the above circumstances, an object of the present invention is to provide a technique that can reduce the impact on communication data flow caused by switching of route settings.

[0005] One aspect of the present invention is a control device that transmits an instruction to switch route settings to a controlled device that transfers communication data between terminals, and the control device comprises: a transmission timing determination unit that determines the timing of transmitting a route setting switching instruction to the controlled device based on the difference in transmission delay time between the controlled devices; and a route setting control unit that transmits a route setting switching instruction to the controlled device at the determined timing.

[0006] According to the present invention, it is possible to reduce the influence of switching of route settings on communication data traffic.

[0007] 6 is an overall configuration diagram of an optical communication system 1 in one embodiment of the present invention. FIG. 7 is a block diagram showing the functional configuration of a control device 300 in one embodiment of the present invention. FIG. 8 is a flowchart showing an example of the operation of a control system in one embodiment of the present invention. FIG. 9 is a diagram showing transmission and reception of communication data between terminals 100. FIG. 10 is a diagram showing a comparative example of transmission and reception of communication data between terminals 100. FIG. 11 is a diagram showing another example of an optical communication system 1 in one embodiment of the present invention. FIG. 12 is a diagram showing a transmission delay time of communication data between each control target device 200 in the optical communication system 1 shown in FIG. 6. FIG. 13 is a diagram showing transmission and reception of communication data between terminals 100.

[0008] Hereinafter, a control device and a control method according to an embodiment of the present invention will be described in detail with reference to the drawings.

[0009] [Configuration of Optical Communication System] Fig. 1 is an overall configuration diagram of an optical communication system 1 according to one embodiment of the present invention. As shown in Fig. 1, the optical communication system 1 is configured to include terminals 100-1 and 100-2, control target devices 200-1 and 200-2, and a control device 300. In the following description, when it is not necessary to distinguish between the terminals 100-1 and 100-2, they may be simply referred to as "terminals 100." In the following description, when it is not necessary to distinguish between the control target devices 200-1 and 200-2, they may be simply referred to as "control target devices 200."

[0010] The control target device 200 is an example of a communication device of the present invention. The control device 300 is an example of a communication control device of the present invention. Furthermore, a control system including the control target device 200 and the control device 300 is an example of a communication control system of the present invention.

[0011] The optical communication system 1 illustrated in FIG. 1 has two terminals 100 and two control target devices 200, but may have more terminals 100 and control target devices 200.

[0012] The terminal 100 transmits and receives communication data to and from other terminals 100 via the control target device 200 .

[0013] The controlled device 200 is installed in a communication network between multiple terminals 100 that communicate with each other. The controlled device 200 is a device that transfers communication data sent and received between the multiple terminals 100. Communication data is input to the controlled device 200 from the terminals 100 or other controlled devices 200. The controlled device 200 outputs the communication data to the terminals 100 or other controlled devices 200.

[0014] Furthermore, the control target device 200 has a plurality of input / output ports. The control target device 200 switches the communication data path through which communication data is transmitted by performing path setting that switches the communication connection between the input / output ports inside the control target device 200. While the control target device 200 is switching the communication data path, it cannot transfer communication data received from the terminal 100 or other control target devices 200. The following description will be given assuming that the time required to switch the communication data path is the same for all control target devices 200.

[0015] The control device 300 controls the path setting performed by the control target device 200. The control device 300 controls the path setting performed by one or more control target devices 200, thereby controlling switching of signal paths for communication data transmitted and received between multiple terminals 100.

[0016] 1, the optical communication system 1 is configured such that one control device 300 controls multiple control target devices 200, but the configuration is not limited to this. For example, the optical communication system 1 may be configured such that a separate control device 300 is installed for each control target device 200.

[0017] [Configuration of Control Device] The following provides a more detailed explanation of the control device 300. Fig. 2 is a block diagram showing the functional configuration of the control device 300 according to an embodiment of the present invention.

[0018] As shown in FIG. 2, the control device 300 includes an inter-device delay time acquisition unit 301 , an inter-device delay time storage unit 302 , a transmission timing determination unit 303 , and a path setting control unit 304 .

[0019] The inter-device delay time acquisition unit 301 acquires information on the transmission delay time of communication data between each control-target device 200, which is notified from a higher-level device or input by an operator through input operations. The transmission delay time of communication data between two control-target devices 200 is the time from when communication data is output from one control-target device 200 to when it is input to the other control-target device 200. In the optical communication system 1 shown in FIG. 1, the transmission delay time of communication data between the control-target device 200-1 and the control-target device 200-2 is the time from when communication data is output from the control-target device 200-1 to when it is input to the control-target device 200-2, and is the time from when communication data is output from the control-target device 200-2 to when it is input to the control-target device 200-1. Information on the transmission delay time of communication data between each control-target device 200 is measured, for example, by sending and receiving Ping between each control-target device 200.

[0020] The inter-device delay time storage unit 302 stores the transmission delay time of communication data between the control target devices 200 acquired by the inter-device delay time acquisition unit 301 .

[0021] The transmission timing determination unit 303 determines the timing for transmitting a path setting switching instruction to each control target device 200 based on the transmission delay time of communication data between each control target device 200 stored in the inter-device delay time memory unit 302.

[0022] The path setting control unit 304 controls path setting by transmitting a path setting switching instruction to each control target device 200 at the transmission timing determined by the transmission timing determination unit 303. When the control target device 200 receives the path setting switching instruction, it starts switching the communication data path.

[0023] A method for determining the transmission timing will be described below. The transmission timing determination unit 303 sets the time between the timing at which a path setting switching instruction is transmitted to one control-target device 200 and the timing at which a path setting switching instruction is transmitted to another control-target device 200 to the transmission delay time of communication data between the two control-target devices 200 that transmit the path setting switching instructions. For example, in FIG. 1, it is assumed that the transmission delay time of communication data between the control-target device 200-1 and the control-target device 200-2 is 10 ms. In this case, the transmission timing determination unit 303 sets the time between the timing at which a path setting switching instruction is transmitted to the control-target device 200-1 and the timing at which a path setting switching instruction is transmitted to the control-target device 200-2 to 10 ms.

[0024] In this case, the timing for sending the route setting switching instruction to the controlled device 200 (controlled device 200-1 in Figure 1) that first receives communication data from the sending terminal 100 is set to a time earlier than the controlled device 200 (controlled device 200-2 in Figure 1) that finally transmits the communication data to the receiving terminal 100.

[0025] In this case, either of the two timings for transmitting the path setting switching instruction may occur first if the terminal 100 performs both transmission and reception. For example, in FIG. 1, when the transmission delay time of communication data between the control-target device 200-1 and the control-target device 200-2 is 10 ms, the transmission timing determination unit 303 may set the timing for transmitting the path setting switching instruction to the control-target device 200-1 to be 10 ms earlier than the timing for transmitting the path setting switching instruction to the control-target device 200-2, and may set the timing for transmitting the path setting switching instruction to the control-target device 200-2 to be 10 ms earlier than the timing for transmitting the path setting switching instruction to the control-target device 200-1.

[0026] 3 is a flowchart showing an example of the operation of a control system according to an embodiment of the present invention. First, the inter-device delay time acquisition unit 301 of the control device 300 acquires information on the transmission delay time of communication data between each of the control-target devices 200 (step S001). The acquired information is stored in the inter-device delay time storage unit 302 (step S002). The transmission timing determination unit 303 determines the timing for transmitting a path setting switch instruction to each of the control-target devices 200 based on the transmission delay time of communication data between each of the control-target devices 200 stored in the inter-device delay time storage unit 302 (step S003). As a result, the time difference between the transmission timings when the control device 300 transmits path setting switch instructions to the two control-target devices 200 is determined.

[0027] When controlling the path setting of the control-target devices 200, the path setting control unit 304 transmits a path setting switching instruction to each control-target device 200 at the transmission timing determined by the transmission timing determination unit 303. When the transmission delay time of communication data between the control-target device 200-1 and the control-target device 200-2 is 10 ms, the path setting control unit 304 transmits a path setting switching instruction to the control-target device 200-1 (step S004-1), and then transmits a path setting switching instruction to the control-target device 200-2 10 ms later (step S004-2). When the control-target device 200-1 and the control-target device 200-2 each receive the path setting switching instruction, they each start switching their communication data paths (step S005). Thereafter, the control-target device 200-1 and the control-target device 200-2 take a predetermined time to complete the switching of their communication data paths.

[0028] Fig. 4 is a diagram showing transmission and reception of communication data between terminals 100. Fig. 4 shows that in the optical communication system 1 shown in Fig. 1, terminal 100-1 transmits communication data to terminal 100-2 via control target device 200-1 and control target device 200-2. In Fig. 4, the start timing of switching of the communication data path is the same, and control target device 200-1 starts switching of the communication data path 10 ms earlier than control target device 200-2.

[0029] At this time, while the control target device 200-1 is switching the communication data path, it is unable to transmit the communication data received from the terminal 100-1 to the control target device 200-2. However, since the start timing of switching the communication data path in the control target device 200-2 is 10 ms (the transmission delay time of the communication data between the control target device 200-1 and the control target device 200-2) later than the start timing of switching the communication data path in the control target device 200-1, the control target device 200-2 can transmit all of the communication data received from the control target device 200-1 to the terminal 100-2. Therefore, the time during which communication data communication in the terminal 100-2 is affected can be kept to approximately the time required for switching the communication data path in the control target device 200-1.

[0030] Fig. 5 is a diagram showing a comparative example of transmission and reception of communication data between terminals 100. In the comparative example shown in Fig. 5, the control device 300 controls the path setting by simultaneously transmitting a path setting switching instruction to the control target device 200-1 and the control target device 200-2. In other words, the control target device 200-1 and the control target device 200-2 simultaneously start switching the communication data path.

[0031] At this time, as shown in Fig. 5, not only is the communication data that the control target device 200-1 receives from the terminal 100-1 while the control target device 200-1 is switching the communication data path unable to be received by the terminal 100-2, but also the communication data that the control target device 200-2 receives from the terminal 100-1 via the control target device 200-1 while the control target device 200-2 is switching the communication data path unable to be received by the terminal 100-2. Therefore, in the comparative example shown in Fig. 5, the time during which communication data communication is affected in the terminal 100-2 is longer than the time required to switch the communication data path in the control target device 200-1.

[0032] As a result, the control device 300 can reduce the impact of communication data communication caused by switching the route setting in the control target device 200 by setting the timing for sending a route setting switching instruction based on the transmission delay time of communication data between the control target device 200, which is the destination.

[0033] Fig. 6 is a diagram showing another example of an optical communication system 1 according to an embodiment of the present invention. Unlike the optical communication system 1 shown in Fig. 1, the optical communication system 1 shown in Fig. 6 includes four control target devices 200 (control target devices 200-1 to 200-4). The control target devices 200-3 and 200-4 transfer communication data transmitted and received between the control target devices 200-1 and 200-2.

[0034] Fig. 7 is a diagram showing the transmission delay time of communication data between the control target devices 200 in the optical communication system 1 shown in Fig. 6. The transmission delay time of communication data between the control target device 200-1 and the control target device 200-3 is 10 ms, the transmission delay time of communication data between the control target device 200-1 and the control target device 200-4 is 15 ms, the transmission delay time of communication data between the control target device 200-3 and the control target device 200-2 is 13 ms, and the transmission delay time of communication data between the control target device 200-4 and the control target device 200-2 is 8 ms.

[0035] Consider that the control device 300 switches the route by which terminal 100-1 transmits communication data to terminal 100-2 from a route passing through control target device 200-1, control target device 200-3, and control target device 200-2 to a route passing through control target device 200-1, control target device 200-4, and control target device 200-2.

[0036] The control device 300 transmits a path setting switching instruction to the control-target device 200 through which communication data did not pass before the path switching and through which communication data will pass after the path switching, earlier than the other control-target devices 200, and causes the control-target device 200 to switch the path setting. In the example shown in Fig. 6, the control-target device 200-4 is the control-target device 200 through which communication data did not pass before the path switching and through which communication data will pass after the path switching. The control device 300 transmits a path setting switching instruction to the control-target device 200-4 earlier than the other control-target devices 200.

[0037] The control device 300 may send a route setting switching instruction to a controlled device 200 through which communication data did not pass before the route switching and through which communication data will pass after the route switching, based on the transmission delay time between the controlled device 200 and the controlled device 200 that first receives communication data from the source terminal 100.

[0038] 6 and 7, the transmission delay time of communication data between the control-target device 200-4 and the control-target device 200-1, which first receives communication data from the source terminal 100-1, is 15 ms. Therefore, the control device 300 only needs to send a path setting switching instruction to the control-target device 200-4 within 15 ms after sending the path setting switching instruction to the control-target device 200-1. This allows the control-target device 200-4 to send the communication data received after the path switching to the control-target device 200-2.

[0039] The control device 300 transmits a path setting switching instruction to a control-target device 200 through which communication data passed before the path switching and through which communication data does not pass after the path switching, based on the transmission delay time between the control-target device 200 and the control-target device 200 that first receives communication data from the source terminal 100. In the example shown in Fig. 6, the control-target device 200-3 is the control-target device 200 through which communication data passed before the path switching and through which communication data does not pass after the path switching.

[0040] 6 and 7, the transmission delay time of communication data between the control target device 200-3 and the control target device 200-1, which first receives communication data from the source terminal 100-1, is 10 ms. Therefore, the control device 300 only needs to transmit a path setting switching instruction to the control target device 200-3 10 ms or more after transmitting the path setting switching instruction to the control target device 200-1. This allows the control target device 200-3 to transmit the communication data received before the path switching to the control target device 200-2.

[0041] For the controlled device 200 that first receives communication data from the source terminal 100 and the controlled device 200 that ultimately transmits the communication data to the destination terminal 100, the control device 300 shifts the transmission delay time of the communication data between the two controlled devices 200 after the path switching and sends a path setting switching instruction.

[0042] In the example shown in FIG. 6, the control-target device 200-1 is the control-target device 200 that first receives communication data from the source terminal 100-1, and the control-target device 200-2 is the control-target device 200 that ultimately transmits the communication data to the destination terminal 100-2. The transmission delay time for communication data between the control-target device 200-1 and the control-target device 200-2 after the path switching is 23 ms (= 15 ms + 8 ms). Therefore, the control device 300 transmits a path setting switching instruction to the control-target device 200-1, and then transmits a path setting switching instruction to the control-target device 200-2 23 ms later to switch the path setting. This reduces the impact of the path setting switching on the control-target device 200 on communication data communication, as explained using the example shown in FIG. 1.

[0043] In addition, the route setting control unit 304 may send a route setting switching instruction to the controlled device 200 to switch the route setting so as to shorten the transmission time of communication data between the terminals 100 based on the transmission delay time of communication data between the controlled devices 200 stored in the inter-device delay time memory unit 302.

[0044] The above explanation has been given on the assumption that the time required to switch the path setting is the same in the control-target devices 200. A case where the time required to switch the path setting in the control-target devices 200 is different will be explained below by taking as an example a case where the time required to switch the path setting in the control-target devices 200-1 and 200-2 in the optical communication system 1 shown in Fig. 1 is t1 and t2, respectively (t1>t2).

[0045] When the times required to switch the path setting differ among the control-target devices 200, it is sufficient for the other control-target devices 200 to be able to transfer the communication data that the control-target device 200 that takes the longest time to switch the path setting transferred last before starting the path setting switch and the communication data that the other control-target devices 200 transferred first after completing the path setting switch. The transmission timing determination unit 303 determines the timing to transmit the path setting switch instruction so that the other control-target devices 200 can transfer the communication data that the control-target device 200 that takes the longest time to switch the path setting transferred last before starting the path setting switch and the communication data that the other control-target devices 200 transferred first after completing the path setting switch.

[0046] 8 is a diagram illustrating the transmission and reception of communication data between terminals 100. If the time when control-target device 200-1 starts path setting switching is set to 0, control-target device 200-2 cannot transfer communication data from time 10 ms to time t1+10 ms. Therefore, control-target device 200-2 only needs to complete path setting switching between time 10 ms and time t1+10 ms. To achieve this, control-target device 200-2 only needs to start path setting switching between time 10 ms and time t1-t2+10 ms, and transmission timing determination unit 303 only needs to determine the timing for transmitting a path setting switching instruction to control-target device 200-2 to be 10 ms after but before t1-t2+10 ms after the timing for transmitting a path setting switching instruction to control-target device 200-1.

[0047] When t1 < t2, if the time when the control target device 200-2 starts the path setting switch is set to 0, the control target device 200-2 cannot transfer communication data from time 0 to time t2. Therefore, the control target device 200-1 only needs to complete the path setting switch between time -10 ms and time t2 - 10 ms. For this purpose, the control target device 200-1 only needs to start the path setting switch between time -10 ms and time t2 - t1 - 10 ms. The transmission timing determination unit 303 determines the timing for transmitting the path setting switch instruction to the control target device 200-2 as time 0, and determines the timing for transmitting the path setting switch instruction to the control target device 200-1 as the timing between time -10 ms and time t2 - t1 - 10 ms.

[0048] Similarly, regarding the timing for transmitting the path setting switch instruction to the control target devices 200-3 and 200-4 shown in FIG. 6, it may also be determined in consideration of the time required for the path setting switch in each control target device 200.

[0049] In the above description, by setting the timing for transmitting the path setting switch instruction from the control device 300 to the control target device 200 to different timings, the timings for starting the path setting switch in the control target device 200 are made different, but it is not limited to this. For example, the control device 300 may simultaneously transmit a path setting switch instruction including information on the timing for starting the path setting switch to a plurality of control target devices 200. At this time, the control target device 200 has a function of adjusting the timing for starting the path setting switch, and starts the path setting switch based on the timing for starting the path setting switch included in the received path setting switch instruction. In this case, without adjusting the timing for transmitting the path setting switch instruction by the control device 300, the timings for starting the path setting switch in the control target device 200 can be made different.

[0050] In the above-described embodiments, some or all of the configurations of the control target device 200 and the control device 300 may be implemented by a computer. In this case, a program for implementing this function may be recorded on a computer-readable recording medium, and the program may be loaded into a computer system and executed. Note that the term "computer system" as used herein includes hardware such as an OS and peripheral devices. Furthermore, "computer-readable recording medium" refers to portable media such as floppy disks, optical magnetic disks, ROMs, and CD-ROMs, as well as storage devices such as hard disks built into computer systems. Furthermore, "computer-readable recording medium" may also include media that dynamically store programs for a short period of time, such as communication lines used when transmitting programs via networks such as the Internet or telephone lines, or media that store programs for a fixed period of time, such as volatile memory within the computer system serving as the server or client. The program may be designed to implement some of the above-described functions, or may be capable of implementing the above-described functions in combination with programs already stored in the computer system, or may be implemented using a programmable logic device such as an FPGA (Field Programmable Gate Array).

[0051] Although an embodiment of the present invention has been described in detail above with reference to the drawings, the specific configuration is not limited to this embodiment, and includes designs within the scope of the present invention that do not deviate from the gist of the present invention.

[0052] 100, 100-1, 100-2... terminals, 200, 200-1, 200-2, 200-3, 200-4... control target devices, 300... control device, 301... inter-device delay time acquisition unit, 302... inter-device delay time storage unit, 303... transmission timing determination unit, 304... path setting control unit

Claims

1. A control device that transmits an instruction to switch route settings to a controlled device that transfers communication data between terminals, comprising: a transmission timing determination unit that determines the timing of transmitting a route setting switching instruction to the controlled device based on the difference in transmission delay time between the controlled devices; and a route setting control unit that transmits a route setting switching instruction to the controlled device at the determined timing.

2. The control device according to claim 1, wherein the time required to switch the route setting is the same in the controlled devices, and the transmission timing determination unit determines the difference in transmission delay time between the controlled devices as the difference in timing for sending the route setting switching instruction to the controlled devices.

3. The control device according to claim 1, wherein the transmission timing determination unit determines the timing for transmitting a path setting switching instruction to the control target device based on the time required for switching the path setting in the control target device.

4. The control device described in claim 1 or 2, wherein the transmission timing determination unit sets the timing for sending the path setting switching instruction to a first controlled device, which is a controlled device through which communication data does not pass before the path is switched and through which communication data passes after the path is switched, to a timing from the time when the path setting switching instruction is sent to a source controlled device, which is a controlled device that first receives communication data from the source terminal, until the time of the transmission delay time between the source controlled device and the first controlled device.

5. The control device described in claim 1 or 2, wherein the transmission timing determination unit sets the timing for sending the path setting switching instruction to a second controlled device, which is a controlled device through which communication data passes before the path is switched and through which communication data does not pass after the path is switched, to a timing after a transmission delay time between the source controlled device and the second controlled device has elapsed, after sending the path setting switching instruction to a source controlled device, which is a controlled device that first receives communication data from the source terminal.

6. A communication control system comprising a controlled device that transfers communication data between terminals, and a control device that transmits an instruction to switch route settings to the controlled device, wherein the control device comprises: a transmission timing determination unit that determines the timing at which the controlled device switches route settings based on the difference in transmission delay time between the controlled devices; and a route setting control unit that transmits a route setting switching instruction to the controlled device that includes information on the determined timing, and the controlled device switches route settings based on the timing included in the route setting switching instruction.

7. A control method for transmitting an instruction to switch a route setting to a controlled device that transfers communication data between terminals, the control method comprising: a transmission timing determination step for determining the timing to transmit a route setting switching instruction to the controlled device based on the difference in transmission delay time between the controlled devices; and a route setting control step for transmitting a route setting switching instruction to the controlled device at the determined timing.

Images