Control device

Abstract

A control device (3) disclosed herein comprises: a selection unit (33) that selects a provisional deletion flow having a delay fluctuation tolerance that is greater than the delay fluctuation tolerance of an additional target flow; a deletion unit (35) that generates a first provisional GCL in which a provisional deletion time slot is deleted; a first determination unit (36) that generates a second provisional GCL in which an additional target time slot is added to the first provisional GCL; and a second determination unit (37) that generates an update GCL in which the provisional deletion time slot is added to the second provisional GCL. If a deletion candidate flow having a transmission cycle that is the same as or an integer fraction of 1 of the transmission cycle of the additional target flow is present among deletion candidate flows, the selection unit (33) selects the deletion candidate flow as a provisional deletion flow. The selection unit (33) selects, as a provisional deletion flow, a deletion candidate flow transmitted in a time slot closest to the position at which the maximum time slot block included in the GCL is divided in equal parts on the time axis.

Description

Control device

[0001] The present disclosure relates to a control device.

[0002] Time Aware Shaper (TAS) is a known technology in which multiple communication devices communicating via a carrier network output frames via the network according to their respective Gate Control Lists (GCLs) (see Non-Patent Document 1).

[0003] When transmitting frames with various transmission periods using the TAS described in Non-Patent Document 1, it is necessary to design a GCL to prevent collisions, which occur when multiple frames are output to a single physical link. Therefore, when a user applies for a new flow, a new GCL is designed so that the time slots for transmitting the flow to be added, which is a flow to be added, do not overlap with the time slots for transmitting existing flows in the existing GCL. In this case, the higher the bandwidth utilization efficiency, i.e., the more time slots for transmitting existing flows in the existing GCL there are, the more difficult it may be to set the time slot for transmitting the flow to be added.

[0004] In order to solve the above-mentioned problem, Non-Patent Document 2 proposes to allow delay fluctuation when adding a time slot for transmitting a flow to be added to an existing GCL.

[0005] “IEEE802.1Qbv - Enhancements for Scheduled Traffic”, [online], [searched April 3, 2023], Internet<URL:https: / / www.ieee802.org / 1 / pages / 802.1bv.html> H.Abe, 6 others, “Improvement of accommodation efficiency by TAS scheduling considering jitter caused by transmission period”, 2023 IEEE 20th Annual Consumer Communications & Networking Conference

[0006] However, in the technology described in Non-Patent Document 2, the smaller the delay variation tolerance value, which is the delay variation allowed for the flow to be added, the higher the possibility that a time slot for transmitting the flow to be added cannot be added to an existing GCL.

[0007] For example, as shown in Figure 9A, when the bandwidth efficiency of communication using an existing GCL is low, i.e., when the existing GCL has few time slots for transmitting existing flows, there is a high degree of freedom in adding time slots for transmitting flows to be added. In Figure 9A, the horizontal axis is the time axis, and time slots for transmitting existing flows used by existing users are hatched, while time slots TS1 to TS4 for transmitting flows to be added are dotted. In this way, in the example shown in Figure 9A, time slots TS1 to TS4 for transmitting flows to be added can be easily added to the existing GCL.

[0008] In contrast, as shown in Figure 9B, for example, when bandwidth efficiency in communications using an existing GCL is high, i.e., when there are many time slots transmitting existing flows in the existing GCL, it becomes difficult to add a time slot transmitting a flow to be added. In Figure 9B, the horizontal axis also represents the time axis, with time slots transmitting existing flows indicated by hatching and time slots TS1 to TS4 transmitting a flow to be added indicated by dots. Thus, in the example shown in Figure 9B, time slots TS1, TS2, and TS4 transmitting flows can be added to the existing GCL. However, since a time slot transmitting an existing flow is set during the period in which time slot TS3 is to be added, time slot TS3-1 must be set immediately after that time slot in a period in which no time slots for any existing flows are set. This causes jitter in the flow to be added, and if the jitter exceeds the delay fluctuation tolerance, it may be impossible to design a new GCL.

[0009] In view of the above circumstances, an object of the present disclosure is to provide a control device that can increase the probability of being able to design a GCL that indicates a schedule for transmitting multiple flows.

[0010] In order to solve the above problem, a control device according to the present disclosure is a control device that controls a communication device having a communication port that transmits a plurality of flows in sequence based on a gate control list, and includes: a gate control list storage unit that stores the gate control list of the communication device; a selection unit that selects, as a provisional deletion flow, at least one of existing flows that are flows whose time slots are included in the gate control list and that have a delay variation tolerance greater than the delay variation tolerance of a target flow to be added that is a flow to be added to the gate control list; a deletion unit that generates a first provisional gate control list by deleting, from the gate control list, a provisional deletion time slot that is a time slot for transmitting the target flow to be added; and a determination unit that determines whether or not the target time slot for transmission of the target flow to be added can be added to the first provisional gate control list, and when it is determined that the target time slot for addition can be added to the first provisional gate control list, adds the target time slot to the first provisional gate control list. a first determination unit that generates a second tentative gate control list to which a target time slot has been added; a second determination unit that determines whether the tentative deletion time slot can be added to the second tentative gate control list, and if it is determined that the tentative deletion time slot can be added, generates an updated gate control list to which the tentative deletion time slot has been added to the second tentative gate control list; and an output unit that outputs the updated gate control list to the communication device, wherein the selection unit selects, when a deletion candidate flow that has a transmission period that is the same as or an integer multiple of the transmission period of the addition target flow among deletion candidate flows that are existing flows having a delay variation tolerance greater than the delay variation tolerance of the addition target flow, as the tentative deletion flow, and when a deletion candidate flow that has a transmission period that is the same as or an integer multiple of the transmission period of the addition target flow does not exist among the deletion candidate flows, selects, from among the time slot blocks consisting of consecutive used time slots included in the gate control list,The candidate flow for deletion that is transmitted in the time slot closest to the position where the maximum time slot block is equally divided on the time axis is selected as the tentatively deleted flow.

[0011] According to the control device of the present disclosure, it is possible to increase the probability of designing a GCL that indicates a schedule for transmitting multiple flows.

[0012] 1 is a schematic diagram showing an example of a communication system including a control device according to the present embodiment. FIG. 1 is a functional configuration diagram showing an example of the control device shown in FIG. 1. FIG. 2 is a schematic diagram for explaining an example of a flow transmitted by the communication device shown in FIG. 1. FIG. 3 is a schematic diagram for explaining a deletion target flow to be deleted from an existing GCL. FIG. 4 is a schematic diagram for explaining an addition target flow to be added to a first provisional GCL. FIG. 5 is a diagram for explaining a deletion target time slot to be added to a second provisional GCL. FIG. 6 is a functional configuration diagram showing an example of a selection unit shown in FIG. 2. FIG. 7 is a diagram showing an example of a schedule update when a addition target flow is added. FIG. 8 is a diagram showing an example of a schedule update when a addition target flow is added by the control device shown in FIG. 2. FIG. 9 is a flowchart showing an example of the operation of the control device shown in FIG. 2. FIG. 10 is a flowchart showing an example of the operation of the selection unit shown in FIG. 2. FIG. 11 is a diagram showing a hardware configuration of the control device shown in FIG. 1. FIG. 12 is a schematic diagram showing the transmission timing of a priority frame when the bandwidth utilization rate is low in the prior art. FIG. 13 is a schematic diagram showing the transmission timing of a priority frame when the bandwidth utilization rate is high in the prior art.

[0013] The overall configuration of this embodiment will be described with reference to Fig. 1. Fig. 1 is a schematic diagram showing an example of a communication system 100 including a control device 3 according to the present disclosure.

[0014] The communication system 100 includes a user device 11 (transmitting terminal 11), a user device 12 (receiving terminal 12), multiple communication devices 2, and a control device 3. The user device 11 and the user device 12 may be transmitting and receiving terminals, respectively. However, hereinafter, an example will be described in which the user device 11 is the transmitting terminal 11 and the user device 12 is the receiving terminal 12.

[0015] <Configuration of Communication Device> Each of the multiple communication devices 2 may use TAS technology in the TSN (Time-Sensitive Networking) standard to receive multiple flows transmitted from the transmitting terminal 11 and transmit and receive them to the receiving terminal 12. The communication device 2 may be, for example, a switch.

[0016] Specifically, the communication device 2 has a communication port that transmits multiple flows in sequence based on a gate control list (GCL). More specifically, the communication device 2 stores a GCL that indicates a schedule for transmitting each of the multiple flows. When the communication device 2 receives a frame, it stores the frame in a queue and transmits the frame at the timing indicated in the GCL. When a GCL is generated by the control device 3, the communication device 2 receives and stores the GCL, and is able to transmit frames based on the stored GCL. In the example described below, the communication device 2 accepts input of an updated gate control list (updated GCL), which is output by the control device 3 and will be described in detail later. The communication device 2 can then execute the above-mentioned processing using the updated GCL.

[0017] <Configuration of Control Device> The control device 3 controls the communication device 2 having a communication port that sequentially transmits multiple flows based on the GCL. As shown in Fig. 2, the control device 3 includes a gate control list storage unit (GCL storage unit) 31, a pre-determination unit 32, a selection unit 33, a parameter storage unit 34, a deletion unit 35, a first determination unit 36, a second determination unit 37, and an output unit 38.

[0018] The GCL storage unit 31 and the parameter storage unit 34 are configured with memory. The memory may be a hard disk drive (HDD), a solid state drive (SSD), an electrically erasable programmable read-only memory (EEPROM), a read-only memory (ROM), a random access memory (RAM), or the like. The pre-determination unit 32, the selection unit 33, the deletion unit 35, the first determination unit 36, and the second determination unit 37 are configured with a controller. The controller may be configured with dedicated hardware such as an application specific integrated circuit (ASIC) or a field-programmable gate array (FPGA), a processor, or may include both. The output unit 38 is configured with an output interface. The output interface may include a communication interface. The communication interface may use standards such as Ethernet (registered trademark), Fiber Distributed Data Interface (FDDI), or Wi-Fi (registered trademark).

[0019] The GCL storage unit 31 stores the GCL of the communication device 2. Furthermore, when an updated GCL is generated by the pre-determination unit 32 or the second determination unit 37, which will be described in detail later, the GCL storage unit 31 stores the generated updated GCL.

[0020] The pre-determination unit 32 determines whether or not a time slot to be added can be added to the GCL (hereinafter, sometimes referred to as the "existing gate control list (existing GCL)") stored in the GCL storage unit 31, based on the flow information of the flow to be added. The time slot to be added is a time slot for transmitting the flow to be added. The flow to be added is a flow to be additionally transmitted by at least one of the multiple communication devices 2 included in the communication system 100. The flow information is information indicating a transmission period, a time slot length, an end-to-end delay tolerance (E2E delay tolerance), and a delay fluctuation tolerance. The time slot length is the length of a time slot in which a frame is transmitted, which is determined for each flow. The E2E delay tolerance is a value determined for each flow and is the maximum E2E delay allowed for a frame. The delay fluctuation tolerance is a value determined for each flow and is the maximum fluctuation delay allowed for a frame. Note that the flow information may be determined by a contract between a user who transmits or receives the flow and a carrier who operates the communication system 100.

[0021] Specifically, the pre-determination unit 32 determines whether or not it is possible to set a time slot to be added during a period in which an existing time slot is not set in the existing GCL, in which a frame of the time slot length indicated in the flow information of the flow to be added can be transmitted in a transmission cycle of the flow so that the E2E delay and delay jitter are equal to or less than the E2E delay tolerance and the delay fluctuation tolerance, respectively. The existing time slot is a time slot for transmitting the existing flow.

[0022] 3A , the flows to be determined by the pre-determination unit 32 will be described. In the example shown in FIG. 3A , the plurality of communication devices 2 described above include communication devices 21 to 27. In the example shown in FIG. 3A , an existing flow FL1 is transmitted in sequence by communication devices 21, 23, 24, 25, and 26. An existing flow FL2 is transmitted in sequence by communication devices 22, 23, 24, 25, and 26. An existing flow FL3 is transmitted in sequence by communication devices 26, 25, and 27. In this example, a flow to be added FL4, which is transmitted in sequence by communication devices 21, 23, 24, 25, and 26, is about to be added. In this case, the pre-determination unit 32 determines whether a target time slot for transmitting the target time slot for transmitting the flow to be added FL4 can be added to a GCL that includes the time slots for transmitting the existing flows FL1, FL2, and FL3.

[0023] Furthermore, when the pre-determination unit 32 determines that the time slot to be added can be added to the existing GCL, it generates a GCL in which the time slot to be added is added to the existing GCL (hereinafter, sometimes referred to as an "updated gate control list (updated GCL)"). Furthermore, the pre-determination unit 32 can store the updated GCL in the GCL storage unit 31. Note that the updated GCL stored by the GCL storage unit 31 will be used as the existing GCL when each functional unit of the control device 3 executes processing thereafter. Furthermore, the pre-determination unit 32 may control the output unit 38 to output the updated GCL to the communication device 2.

[0024] The selection unit 33 selects, as a provisional deletion flow, at least one of the existing flows, which are flows whose time slots are included in the existing GCL (as described above, the GCL stored in the GCL memory unit 31), that has a delay fluctuation tolerance value greater than the delay fluctuation tolerance value of the target flow to be added, which is a flow to be added to the existing GCL.

[0025] Specifically, the selection unit 33 may not execute the process if the pre-determination unit 32 determines that the target time slot can be added to the existing GCL. The selection unit 33 may select the provisional deletion flow if the pre-determination unit 32 determines that the target time slot cannot be added to the existing GCL.

[0026] 4 is a diagram showing an example of the configuration of the selection unit 33. As shown in FIG. 4, the selection unit 33 includes a first selection unit 331, a second selection unit 332, and a third selection unit 333.

[0027] The first selection unit 331 selects a deletion candidate flow, which is a candidate for a provisional deletion flow, from among existing flows whose time slots are included in the existing GCL based on the jitter requirement (tolerance of delay variation) of the flow to be added. Specifically, the first selection unit 331 selects, as a deletion candidate flow, an existing flow whose delay variation tolerance is greater than the delay variation tolerance of the flow to be added, from among existing flows whose time slots are included in the existing GCL. Note that the first selection unit 331 may also select, as a deletion candidate flow, an existing flow whose delay variation margin value is greater than a predetermined threshold. The delay variation margin value is a value obtained by subtracting the actually allowed delay variation value from the delay variation margin value. The actually allowed delay variation value is a value indicating how much the time slots of the existing flows in the existing GCL are shifted from their original transmission cycles.

[0028] If there is a deletion candidate flow among the deletion candidate flows selected by the first selection unit 331 that has a transmission period that is the same as or an integer multiple of the transmission period of the flow to be added, the second selection unit 332 selects the deletion candidate flow as a provisional deletion flow.

[0029] The third selection unit 333 selects, as a provisional deletion flow, a deletion candidate flow that is transmitted in a time slot that is closest to the position on the time axis where the maximum time slot block, which has the longest time length, is equally divided from among time slot blocks that are composed of consecutive used time slots (time slots that transmit existing flows) included in the existing GCL.

[0030] Specifically, the third selection unit 333 compares the maximum time length of a time slot block (maximum time slot block length) when each of the deletion candidate flows selected by the first selection unit 331 is deleted, and then selects the deletion candidate flow with the shortest maximum time slot block length as the tentative deletion flow.

[0031] For example, if the maximum time slot block length is shorter than the transmission period of the flow to be added, the third selection unit 333 selects the deletion candidate flow closest to the center of the maximum time slot block as the provisional deletion flow.Also, if the maximum time slot block length is longer than the transmission period of the flow to be added, and the maximum time slot block length ÷ the transmission period of the flow to be added = n, the third selection unit 333 selects the deletion candidate flow closest to the position where the maximum time slot block is divided into n+1 equal parts as the provisional deletion flow.

[0032] In addition, the third selection unit 333 may select a provisional deletion flow when the second selection unit 332 determines that there is no deletion candidate flow (existing flow having a delay fluctuation tolerance value greater than the delay fluctuation tolerance value of the flow to be added) that has a transmission period that is the same as or an integer multiple of the transmission period of the flow to be added.

[0033] In this way, the selection unit 33 selects at least one of the existing flows (candidate for deletion flows) that have a delay variation tolerance greater than the delay variation tolerance of the flow to be added as a provisional deletion flow from among the existing flows whose time slots are included in the existing GCL.

[0034] Here, if there is a deletion candidate flow among the deletion candidate flows (existing flows with a delay fluctuation tolerance greater than the delay fluctuation tolerance of the flow to be added) that has a transmission period that is the same as or an integer multiple of the transmission period of the flow to be added, the selection unit 33 selects the deletion candidate flow as a provisional deletion flow.

[0035] Furthermore, if the selection unit 33 determines that there is no deletion candidate flow among the deletion candidate flows that has a transmission period that is the same as or an integer multiple of the transmission period of the flow to be added, the selection unit 33 selects as the provisional deletion flow the deletion candidate flow that is transmitted in the time slot that is closest to the position where the largest time slot block among the time slot blocks consisting of consecutive used time slots included in the existing GCL is equally divided on the time axis.

[0036] Referring back to FIG. 2, the parameter storage unit 34 stores the flow information of the provisionally deleted flow selected by the selection unit 33.

[0037] The deletion unit 35 generates a first provisional gate control list (first provisional GCL) by deleting the provisional deletion time slot, which is the time slot for transmitting the provisional deletion flow selected by the selection unit 33, from the existing GCL (the GCL stored in the GCL memory unit 31, as described above).

[0038] The first determination unit 36 ​​determines whether or not it is possible to add a target time slot, which is a time slot for transmitting a target flow to be added, to the first provisional GCL. Specifically, the first determination unit 36 ​​determines whether or not it is possible to set a time slot for transmitting a flow of the time slot length indicated in the flow information of the target flow to be added, in a transmission period of the target flow to be added, so that the E2E delay and delay jitter are equal to or less than the E2E delay tolerance and the delay fluctuation tolerance, respectively, during a period when no existing time slot is set in the first provisional GCL.

[0039] In the example shown in Fig. 3B, the deletion unit 35 generates a first provisional GCL by deleting the existing time slot of the existing flow FL1 (see Fig. 3A) from the GCL, and the first determination unit 36 ​​determines whether the addition target flow FL4 can be added to the first provisional GCL.

[0040] In addition, if the first judgment unit 36 ​​determines that the time slot to be added can be added to the first interim GCL, it generates a second interim gate control list (second interim GCL) in which the time slot to be added is added to the first interim GCL.

[0041] The second determination unit 37 determines whether a provisional deletion time slot for transmitting a provisional deletion flow can be added to the second provisional GCL. Specifically, the second determination unit 37 determines whether a provisional deletion time slot can be added to the second provisional GCL based on the flow information of the flow to be deleted. More specifically, the second determination unit 37 determines whether a provisional deletion time slot can be set during a period in which a time slot is not set in the second provisional GCL, for transmitting a flow having a time slot length indicated in the flow information of the provisional deletion flow, in a transmission period of the flow, so that the E2E delay and delay jitter are equal to or less than the E2E delay tolerance and delay fluctuation tolerance of the provisional deletion flow, respectively.

[0042] In the example shown in Figure 3B, if it is determined that the flow to be added FL4 can be added to the first interim GCL, a second interim GCL is generated, and the second judgment unit 37 determines whether a provisional deletion time slot F1 as shown in Figure 3C can be added to the second interim GCL.

[0043] Furthermore, if the second determination unit 37 determines that a provisional deletion time slot for transmitting the provisional deletion flow can be added to the second provisional GCL, the second determination unit 37 generates a GCL (hereinafter, sometimes referred to as an "updated gate control list (updated GCL)") in which the provisional deletion time slot for transmitting the provisional deletion flow has been added to the second provisional GCL. The second determination unit 37 also stores the updated GCL in the GCL storage unit 31. The updated GCL stored by the GCL storage unit 31 will be used as the existing GCL when each of the above-mentioned functional units executes processing thereafter. The second determination unit 37 may also control the output unit 38 to output the updated GCL to the communication device 2.

[0044] 3C , if it is determined that a provisional deletion time slot for transmitting the provisional deletion flow FL1 can be added to the second provisional GCL, the second determination unit 37 generates an updated GCL in which the provisional deletion time slot for transmitting the provisional deletion flow FL1 is added to the second provisional GCL as shown in FIG. 3D . The second determination unit 37 may also control the output unit 38 to output the updated GCL to the communication device 2.

[0045] Furthermore, if the first determination unit 36 ​​determines that the time slot to be added cannot be added to the first provisional GCL, or if the second determination unit 37 does not determine that the time slot to be temporarily deleted can be added to the second provisional GCL, the selection unit 33 selects an additional flow to be temporarily deleted, and the deletion unit 35 deletes the additionally selected flow to be temporarily deleted from the existing GCL, as described above. At this time, the selection unit 33 selects an additional flow to be temporarily deleted from the existing flows excluding the flows already selected as flows to be temporarily deleted, as described above. Then, the processing by the first determination unit 36, or the processing by the first determination unit 36 ​​and the second determination unit 37, is repeated.

[0046] Here, the above-mentioned selection unit 33 can determine whether the number of selected flows to be temporarily deleted is equal to or greater than a threshold. In this configuration, if it is determined that the number of flows to be temporarily deleted is equal to or greater than the threshold, the selection unit 33 can determine that it is not possible to generate a GCL indicating a schedule for transmitting multiple flows including the flow to be added and the existing flows. In this case, the selection unit 33 may control the output unit 38 to output update disable information to another device (e.g., the communication device 2, a display device, or another control device). The update disable information is information indicating that it is not possible to generate a GCL indicating a schedule for transmitting multiple flows including the flow to be added and the existing flows.

[0047] The output unit 38 outputs the updated GCL to the communication device 2 under the control of the second determination unit 37 as described above. The output unit 38 may also output the update disable information to another device under the control of the selection unit 33 as described above.

[0048] The control device 3 described above does not need to include the pre-determination unit 32. In such a configuration, the selection unit 33 can select a flow to be provisionally deleted from the existing flows without processing by the pre-determination unit 32.

[0049] One possible method for adding a target flow to be added is to delete and initialize all schedules, as shown in Figure 5A, and then schedule flows with a small delay variation tolerance first, followed by flows with a large delay variation tolerance. However, this method requires longer calculation time than adding a target flow to an existing schedule. Furthermore, this method changes the transmission timing of each flow when the schedule is switched, which may result in temporary delay variation. In Figure 5A, the horizontal axis is the time axis, and time slots in which existing flows used by existing users are transmitted are hatched.

[0050] Therefore, in this embodiment, when adding a flow to be added, the provisionally deleted flow is deleted from the existing flow whose time slot is included in the existing GCL, and then the time slot to be added is added to the GCL. In other words, some of the existing flows are deleted, and then the flow to be added is added.

[0051] Here, as shown in Figure 5B, if there is a bias in the time slots to be deleted, it may be impossible to add a time slot transmitting a flow to be added to the GCL. For example, as shown in Figure 5B, if many existing flows are deleted in the first half of a certain interval and many existing flows in the second half are not deleted, it is highly likely that time slots TS1 and TS2 of the flow to be added, which are transmitted in the first half, can be scheduled, but time slots TS3 and TS4 of the flow to be added, which are transmitted in the second half, cannot be scheduled. Note that in Figure 5B, the horizontal axis is the time axis, and time slots in which existing flows used by existing users are transmitted are hatched, and time slots TS1 to TS4 of the flow to be added are transmitted are dotted.

[0052] Therefore, in this embodiment, as shown in Fig. 5C, the control device 3 (selector 33) selects flows to be temporarily deleted so that the time slots to be deleted are not biased. This increases the possibility that all of the time slots TS1, TS2, TS3, and TS4 of the flow to be added can be scheduled.

[0053] Specifically, if there is a deletion candidate flow with a transmission period equal to or equal to an integer multiple of the transmission period of the flow to be added among the deletion candidate flows with a delay variation tolerance greater than the delay variation tolerance of the flow to be added, the selector 33 selects the deletion candidate flow as a provisional deletion flow. This deletes the time slot of the provisional deletion flow. Typically, flows have a predetermined transmission period. By deleting the time slot of an existing flow with a transmission period equal to or equal to an integer multiple of the transmission period of the flow to be added, it is possible to add a time slot to be added in place of the deleted time slot.

[0054] Furthermore, if there is no existing flow whose transmission period is the same as or an integral multiple of the transmission period of the flow to be added, the selector 33 selects, as a tentative deletion flow, a deletion candidate flow transmitted in a time slot closest to the position where the largest time slot block included in the GCL is equally divided on the time axis. This causes the time slots of the deletion candidate flow to be deleted with a predetermined periodicity. By using the time slots of the deletion candidate flow deleted with a predetermined periodicity and time slots that are available from the beginning, it becomes more likely that the addition target time slot can be added.

[0055] Therefore, according to the present disclosure, it is possible to increase the probability of being able to design a GCL that indicates a schedule for transmitting multiple flows.

[0056] <Operation of Control Device> Here, the operation of the control device 3 according to this embodiment will be described with reference to Fig. 6. Fig. 6 is a flowchart showing an example of the operation of the control device 3 according to this embodiment. The operation of the control device 3 described with reference to Fig. 6 corresponds to an example of a control method executed by the control device 3 according to this embodiment.

[0057] In step S11, the pre-determination unit 32 determines whether or not a time slot to be added for transmitting the flow to be added can be added to the existing GCL based on the flow information of the flow to be added. As described above, the flow information is information indicating the frame length, transmission period, E2E delay tolerance, and delay fluctuation tolerance.

[0058] If it is determined in step S11 that the target time slot cannot be added to the existing GCL, in step S12 the selector 33 selects a provisionally deleted flow, which is at least one of the existing flows having a delay variation tolerance greater than the delay variation tolerance of the target flow to be added. At this time, the selector 33 can store flow information of the provisionally deleted flow in the parameter storage 34.

[0059] FIG. 7 is a flowchart showing an example of the operation of the selection unit 33 in step S12.

[0060] In step S121, the selector 33 (first selector 331) selects, based on the jitter requirement of the flow to be added, a deletion candidate flow from among the existing flows whose time slots are included in the existing GCL. Specifically, the selector 33 selects, as the deletion candidate flow, an existing flow whose delay variation tolerance is greater than the delay variation tolerance of the flow to be added, from among the existing flows whose time slots are included in the existing GCL.

[0061] In step S122, the selector 33 (second selector 332) determines whether any existing flow among the deletion candidate flows has a transmission period that is the same as or an integer multiple of the transmission period of the flow to be added. If it is determined that any existing flow among the deletion candidate flows has a transmission period that is the same as or an integer multiple of the transmission period of the flow to be added, the selector 33 selects the deletion candidate flow as a provisional deletion flow and terminates the process.

[0062] If it is determined in step S122 that there is no deletion candidate flow among the deletion candidate flows that has a transmission period that is the same as or an integer multiple of the transmission period of the flow to be added, in step S123, the selection unit 33 (third selection unit 333) selects as a provisional deletion flow a deletion candidate flow that is transmitted in a time slot from among the time slot blocks included in the existing GCL that is closest to the position that equally divides the maximum time slot block on the time axis, and terminates the processing.

[0063] Referring back to FIG. 6, in step S13, the deletion unit 35 generates a first provisional GCL by deleting the provisional deletion time slot for transmitting the provisional deletion flow from the GCL.

[0064] In step S14, the first determination unit 36 ​​determines whether or not the time slot to be added can be added to the first provisional GCL.

[0065] If it is determined in step S14 that the time slot to be added can be added to the first interim GCL, then in step S15, the first determination unit 36 ​​generates a second interim GCL in which the time slot to be added is added to the first interim GCL.

[0066] In step S16, the second determination unit 37 determines whether or not a provisional deletion time slot can be added to the second provisional GCL.

[0067] If it is determined in step S11 that the time slot to be added can be added to the existing GCL, the pre-determination unit 32 generates an updated GCL in which the time slot to be added is added to the existing GCL in step S17. Also, if it is determined in step S16 that the time slot to be temporarily deleted can be added to the second provisional GCL, the second determination unit 37 generates an updated GCL in which the time slot to be temporarily deleted is added to the second provisional GCL in step S17.

[0068] In step S18, the second determination unit 37 stores the updated GCL in the GCL storage unit 31.

[0069] In step S19 , the output unit 38 outputs the updated GCL to the communication device 2 .

[0070] Also, if the first judgment unit 36 ​​determines in step S14 that the time slot to be added cannot be added to the first provisional GCL, or if it determines in step S16 that the time slot to be temporarily deleted cannot be added to the second provisional GCL, the control device 3 returns to step S12 and repeats the processing.

[0071] In the above-described operation, when the selector 33 selects a provisional deletion flow in step S12, it can determine whether the number of provisional deletion flows is equal to or greater than a threshold. In this configuration, if it is determined that the number of provisional deletion flows is less than the threshold, the control device 3 can proceed to step S13. If it is determined that the number of provisional deletion flows is equal to or greater than the threshold, the output unit 38 outputs update disable information, and then the control device 3 can terminate its operation.

[0072] As described above, the control device 3 according to this embodiment includes a GCL storage unit 31, a selection unit 33, a deletion unit 35, a first determination unit 36, a second determination unit 37, and an output unit 38. The GCL storage unit 31 stores the GCL of the communication device. The selection unit 33 selects, as a provisional deletion flow, at least one existing flow having a delay variation tolerance greater than the delay variation tolerance of the flow to be added, from among existing flows whose time slots are included in the GCL. The deletion unit 35 generates a first provisional GCL by deleting the provisional deletion time slot from the GCL. The first determination unit 36 ​​determines whether the time slot to be added can be added to the first provisional GCL. If the first determination unit 36 ​​determines that the time slot to be added can be added to the first provisional GCL, the first determination unit 36 ​​generates a second provisional GCL by adding the time slot to be added to the first provisional GCL. The second determination unit 37 determines whether a temporary deletion time slot can be added to the second temporary GCL. If the second determination unit 37 determines that a temporary deletion time slot can be added, the second determination unit 37 generates an updated gate control list in which the temporary deletion time slot is added to the second temporary GCL. The output unit 38 outputs the updated GCL to the communication device 2.

[0073] Here, if the deletion candidate flows include a deletion candidate flow whose transmission period is the same as or an integral multiple of the transmission period of the flow to be added, the selector 33 selects the deletion candidate flow as a provisional deletion flow.Also, if the deletion candidate flows do not include a deletion candidate flow whose transmission period is the same as or an integral multiple of the transmission period of the flow to be added, the selector 33 selects, as a provisional deletion flow, a deletion candidate flow transmitted in a time slot that is closest to the position that equally divides the largest time slot block on the time axis, from among time slot blocks made up of consecutive used time slots included in the GCL.

[0074] This allows the control device 3 according to this embodiment to increase the probability of successfully designing a GCL that indicates a schedule for transmitting multiple flows. In particular, the control device 3 according to this embodiment selects, as a tentative deletion flow, a deletion candidate flow that has a transmission period that is the same as or an integral multiple of the transmission period of the flow to be added, or a deletion candidate flow that is transmitted in a time slot that is closest to the position that equally divides the largest time slot block on the time axis, thereby enabling the existing flows to be deleted evenly. As a result, the control device 3 according to this embodiment can further increase the probability of successfully designing a GCL that indicates a schedule for transmitting multiple flows.

[0075] The control device 3 of this embodiment further includes a pre-determination unit 32 that determines whether a time slot to be added for transmitting a flow to be added can be added to an existing GCL based on flow information indicating the frame length, transmission period, E2E delay tolerance, and delay fluctuation tolerance of the flow to be added, and if it is determined that the time slot to be added can be added, generates an updated GCL in which the time slot to be added is added to the existing GCL. Furthermore, the selection unit 33 can select a flow to be provisionally deleted if it is determined that the time slot to be added cannot be added to the existing GCL.

[0076] As a result, the control device 3 may be able to generate an updated GCL without performing the processes of selecting a provisional deletion flow, deleting the provisional deletion flow from the existing GCL, and adding the provisional deletion flow to the second provisional GCL. Therefore, the control device 3 may be able to generate an updated GCL with a small processing load.

[0077] <Program> The above-described control device 3 can be realized by a computer 401. A program for causing the above-described control device 3 to function may be provided. The program may be stored in a storage medium or provided via a network. FIG. 8 is a block diagram showing a schematic configuration of a computer 401 functioning as the control device 3. Here, the computer 401 may be a general-purpose computer, a dedicated computer, a workstation, a PC (Personal Computer), an electronic notepad, or the like. The program instructions may be program code, code segments, or the like for executing necessary tasks.

[0078] 8, the computer 401 includes a processor 410, a read-only memory (ROM) 420, a random access memory (RAM) 430, a storage 440, an input unit 450, an output unit 460, and a communication interface (I / F) 470. Each component is communicably connected to one another via a bus 480. The processor 410 is specifically a central processing unit (CPU), a micro processing unit (MPU), a graphics processing unit (GPU), a digital signal processor (DSP), a system on a chip (SoC), or the like, and may be configured by multiple processors of the same type or different types.

[0079] The processor 410 controls each component and executes various arithmetic processes. That is, the processor 410 reads a program from the ROM 420 or the storage 440 and executes the program using the RAM 430 as a work area. The processor 410 controls each component and executes various arithmetic processes in accordance with the program stored in the ROM 420 or the storage 440. In the above-described embodiment, the program according to the present disclosure is stored in the ROM 420 or the storage 440.

[0080] The program may be stored in a storage medium readable by the computer 401. Using such a storage medium, the program can be installed in the computer 401. Here, the storage medium on which the program is stored may be a non-transitory storage medium. The non-transitory storage medium is not particularly limited, and may be, for example, a CD-ROM, a DVD-ROM, or a USB (Universal Serial Bus) memory. Furthermore, the program may be downloaded from an external device via a network.

[0081] The ROM 420 stores various programs and various frames. The RAM 430 temporarily stores programs or frames as a working area. The storage 440 is configured with a hard disk drive (HDD) or a solid state drive (SSD) and stores various programs including the operating system and various frames.

[0082] The input unit 450 includes one or more input interfaces that receive input operations from a user and acquire information based on the user operations. For example, the input unit 450 may be, but is not limited to, a pointing device, a keyboard, a mouse, or the like.

[0083] The output unit 460 includes one or more output interfaces that output information. For example, the output unit 460 may be, but is not limited to, a display that outputs information as a video or a speaker that outputs information as an audio. If the output unit 460 is a touch panel display, it also functions as the input unit 450.

[0084] The communication interface (I / F) 470 is an interface for communicating with external devices.

[0085] The following supplementary note is further disclosed in relation to the above-described embodiment: [Supplementary note 1] A control device for controlling a communication device having a communication port for sequentially transmitting a plurality of flows based on a gate control list, comprising: a memory, a controller, and an output interface, wherein the memory stores the gate control list of the communication device, and the controller: selects, as a provisional deletion flow, at least one of existing flows whose time slots are included in the gate control list and whose delay variation tolerance is greater than the delay variation tolerance of a to-be-added flow that is a flow to be added to the gate control list, from existing flows whose time slots are included in the gate control list, generates a first provisional gate control list by deleting, from the gate control list, a provisional deletion time slot that is a time slot for transmitting the provisional deletion flow, determines whether or not it is possible to add, to the first provisional gate control list, a to-be-added time slot that is a time slot for transmitting the to-be-added flow, and if it is determined that it is possible to add, to the first provisional gate control list, generates a second provisional gate control list by adding, to the first provisional gate control list, determining whether the provisional deletion time slot can be added to the second provisional gate control list, and if it is determined that the provisional deletion time slot can be added, generating an updated gate control list in which the provisional deletion time slot is added to the second provisional gate control list; the output interface outputs the updated gate control list to the communication device; and the controller, if there is a deletion candidate flow having a transmission period that is the same as or an integer multiple of the transmission period of the addition target flow among deletion candidate flows that are existing flows having a delay variation tolerance greater than the delay variation tolerance of the addition target flow, selects the deletion candidate flow as the provisional deletion flow;a control device that, when there is no deletion candidate flow that has a transmission period that is the same as or an integer multiple of the transmission period of the flow to be added, selects, as a flow to provisionally delete, a deletion candidate flow that is transmitted in a time slot that is closest to a position that equally divides the largest time slot block on the time axis, from among a time slot block consisting of consecutive used time slots included in the gate control list. [Supplementary Item 2] In the control device described in Supplementary Item 1, the controller determines whether or not a time slot to be added for transmitting the flow to be added can be added to the gate control list based on flow information that indicates the frame length, transmission period, end-to-end delay tolerance, and delay variation tolerance of the flow to be added, and, when it is determined that the time slot to be added can be added, generates an updated gate control list by adding the time slot to be added to the gate control list, and when it is determined that the time slot to be added cannot be added to the gate control list, selects the flow to provisionally delete.

[0086] All publications, patent applications, and technologies mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent application, and technology was specifically and individually indicated to be incorporated by reference.

[0087] Although the above-described embodiments have been described as typical examples, it will be apparent to those skilled in the art that many modifications and substitutions can be made within the spirit and scope of the present disclosure. Therefore, the present invention should not be construed as being limited by the above-described embodiments, and various modifications or alterations are possible without departing from the scope of the claims.

[0088] 2, 21 to 27 Communication device 3 Control device 11 User device (transmitting terminal) 12 User device (receiving terminal) 31 Gate control list storage unit (GCL storage unit) 32 Pre-determination unit 33 Selection unit 34 Parameter storage unit 35 Deletion unit 36 ​​First determination unit 37 Second determination unit 38 Output unit 100 Communication system 331 First selection unit 332 Second selection unit 333 Third selection unit 401 Computer 410 Processor 420 ROM 430 RAM 440 Storage 450 Input unit 460 Output unit 470 Communication interface 480 Bus

Claims

1. A control device for controlling a communication device having a communication port that transmits a plurality of flows in sequence based on a gate control list, comprising: a gate control list storage unit that stores the gate control list of the communication device; a selection unit that selects, as a provisional deletion flow, at least one of existing flows whose time slots are included in the gate control list and that has a delay variation tolerance greater than the delay variation tolerance of a target flow to be added which is a flow to be added to the gate control list; a deletion unit that generates a first provisional gate control list by deleting, from the gate control list, a provisional deletion time slot which is a time slot for transmitting the provisional deletion flow; and a first determination unit that determines whether or not a target time slot to be added which is a time slot for transmitting the target flow to be added can be added to the first provisional gate control list, and when it is determined that the target time slot to be added can be added to the first provisional gate control list, generates a second provisional gate control list by adding the target time slot to be added to the first provisional gate control list. a second determination unit that determines whether the provisional deletion time slot can be added to the second provisional gate control list, and if it is determined that the provisional deletion time slot can be added, generates an updated gate control list in which the provisional deletion time slot is added to the second provisional gate control list; and an output unit that outputs the updated gate control list to the communication device, wherein the selection unit, when a deletion candidate flow having a transmission period equal to or equal to an integer multiple of the transmission period of the addition target flow exists among deletion candidate flows that are existing flows having a delay variation tolerance greater than the delay variation tolerance of the addition target flow, selects the deletion candidate flow as the provisional deletion flow,A control device that, when there is no deletion candidate flow among the deletion candidate flows that has a transmission period that is the same as or an integer multiple of the transmission period of the flow to be added, selects as a provisional deletion flow a deletion candidate flow that is transmitted in a time slot that is closest to a position that equally divides the maximum time slot block on the time axis among time slot blocks consisting of consecutive used time slots included in the gate control list.

2. A control device as described in claim 1, further comprising a pre-determination unit which determines whether or not a target time slot for adding, for transmitting a target flow to be added, can be added to the gate control list based on flow information indicating the frame length, transmission period, end-to-end delay tolerance, and delay fluctuation tolerance of the target flow to be added, and if it is determined that the target time slot can be added, generates an updated gate control list in which the target time slot for addition has been added to the gate control list; and if it is determined that the target time slot for addition cannot be added to the gate control list, the selection unit selects the provisionally deleted flow.

Images