Control device, communication system, control method and program

Abstract

Provided is a control device including a method determination unit that determines whether a packet with a priority identifier has been transmitted according to a grant-free method, a time estimation unit that estimates a time at which a packet traffic volume becomes greater than or equal to a threshold, and a transfer control unit that generates a control signal for controlling a signal transfer device to transfer a packet arrived at the signal transfer device at the estimated time according to the priority identifier. The method determination unit determines whether repeated packet transmission is performed. When it is determined that the repeated packet transmission is performed, the time estimation unit estimates time in which multiple packets arrive at the signal transfer device a predetermined number of times at a predetermined time interval.

Description

[Technical Field]

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

[0002] In a switch network accommodating multiple services, packet forwarding control may be performed using a Time Aware Shaper (TAS) in the Time-Sensitive Networking (TSN) of the IEEE 802.1 standard (see Patent Document 1). In this case, a Virtual Local Area Network (VLAN), a priority code point (PCP), or a Quality of Service (QoS) is assigned to a packet as an identifier of the packet's priority class.

[0003] Furthermore, in the 5th Generation Mobile Communication System (5G), grant-free (configured grant) is specified for uplink packet transfer in order to realize low-latency services using Ultra Reliable and Low Latency Communication (URLLC) and the like (see Non-Patent Documents 2 and 3). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-092317 [Non-patent literature]

[0005] [Non-Patent Document 1] “Time-Sensitive Networking for Fronthaul”, IEEE Std P802.1CM, May 7, 2018 [Non-patent document 2] “System architecture for the 5G System (5GS)”, 3GPP TS23.501 [Non-patent document 3] “NR; NR and NG-RAN Overall Description”, 3GPP TS 38.300 Summary of the Invention [Problem to be solved by the invention]

[0006] By using grant-free, it is possible to reduce the control time required for scheduling requests and resource allocation for wireless terminals, and also to ensure strict reliability for the control channel.

[0007] Furthermore, in the fifth generation mobile communication system, a high-priority identifier defined in 5QI (5G QoS Identifier) ​​may be assigned to packets of URLLC services and the like that require low latency.

[0008] The "k-repetition" method introduced in Release 15 of "3GPP TS 38.300" involves repeatedly transmitting packets (a predetermined number of times). This can result in excessive packet repetition depending on the quality of service provided to the wireless terminal. When multiple wireless terminals exist, collisions between packets transmitted from different wireless terminals may limit the improvement in reliability.

[0009] However, when there are multiple services that require low latency, there is no distinction between the priority levels of the different services, and packets from different services are recognized as packets of the same priority level. As a result, even in time slots used for transmitting high-priority packets, the reserved time for transmission becomes long, and it becomes impossible to suppress the increase in the latency of packets assigned with high-priority identifiers.

[0010] In view of the above circumstances, the present invention aims to provide a control device, a communication system, a control method, and a program that can suppress an increase in delay time of packets assigned a high priority identifier. [Means for solving the problem]

[0011] One aspect of the present invention is a control device that includes a method determination unit that determines whether a packet assigned a priority identifier has been transmitted using a grant-free method, a time estimation unit that estimates the time when the traffic volume of the packet will be greater than or equal to a threshold, and a transfer control unit that generates a control signal for the signal transfer device so that the signal transfer device transfers packets that arrive at the signal transfer device at the estimated time in accordance with the priority identifier.

[0012] One aspect of the present invention is a communication system comprising a signal transfer device that transfers packets and a control device, wherein the control device has a method determination unit that determines whether the packet to which a priority identifier has been assigned has been transmitted using a grant-free method, a time estimation unit that estimates the time at which the traffic volume of the packet will be greater than or equal to a threshold, and a transfer control unit that generates a control signal for the signal transfer device so that the signal transfer device transfers packets that arrive at the signal transfer device at the estimated time in accordance with the priority identifier.

[0013] One aspect of the present invention is a control method executed by a control device, which includes a method determination step of determining whether a packet assigned a priority identifier has been transmitted using a grant-free method, a time estimation step of estimating the time when the traffic volume of the packet will be equal to or greater than a threshold, and a transfer control step of generating a control signal for the signal transfer device so that the signal transfer device transfers packets that arrive at the signal transfer device at the estimated time in accordance with the priority identifier.

[0014] One aspect of the present invention is a program for causing a computer to function as the above-described control device. [Effects of the Invention]

[0015] According to the present invention, it is possible to suppress an increase in delay time of packets to which a high-priority identifier is assigned. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a communication system in a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a signal transfer control device in the first embodiment. [Figure 3] FIG. 3 is a diagram illustrating an example of a time series of traffic volume related to a signal transfer device in the first embodiment. [Figure 4] 4 is a flowchart showing an example of the operation of the signal transfer control device in the first embodiment. [Figure 5] FIG. 10 is a diagram illustrating an example of the configuration of a communication system in a second embodiment. [Figure 6] FIG. 10 is a diagram illustrating an example of the configuration of a signal transfer control device in a second embodiment. [Figure 7] FIG. 2 is a diagram illustrating an example of a hardware configuration of a signal transfer control device in each embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the accompanying drawings. (First embodiment) 1 is a diagram showing an example of the configuration of a communication system 1a in the first embodiment. The communication system 1a is a system that communicates using signals (packets). The packets are transmitted through a predetermined path that includes one or more signal transfer devices.

[0018] The priority identifier assigned to the packet is not limited to an identifier of a specific system. For example, a high-priority identifier defined in 5QI (5G QoS Identifier) ​​may be assigned to the packet in advance. A high-priority identifier defined in, for example, VLAN, PCP, or QoS may also be assigned to the packet in advance. The packet may be a packet of a low-latency service using Ultra Reliable Low Latency Communication (URLLC) or the like.

[0019] The communication system 1a includes a higher-level device 2, a central station 3, a signal transfer control device 4, N (N is an integer equal to or greater than 1) signal transfer devices 5, M (M is an integer equal to or greater than 1) remote stations 6, and M wireless stations 7. One or more wireless terminals 8 can be communicatively connected to the wireless station 7 associated with the remote station 6.

[0020] The higher-level device 2 acquires upstream data from the wireless terminal 8 via the wireless station 7, the remote station 6, the signal forwarding device 5, and the central station 3. The higher-level device 2 transmits downstream data to the wireless terminal 8 via the central station 3, the signal forwarding device 5, the remote station 6, and the wireless station 7.

[0021] The central station 3 receives signals from one or more signal transfer devices 5. The central station 3 transmits upstream data corresponding to the received signals to the higher-level device 2. The central station 3 receives downstream data from the higher-level device 2. The central station 3 transmits signals corresponding to the downstream data to each signal transfer device 5.

[0022] The signal transfer control device 4 (control device) acquires cooperation information notified from the remote station 6 in a predetermined radio resource scheduling unit (for example, TTI (Transmission Time Interval) or slot unit). The cooperation information is information used for cooperation between the signal transfer control device 4 and the remote station 6. The time interval (transmission time interval) of the scheduling unit is, for example, 1 ms or 125 μs.

[0023] The cooperation information includes, for example, Radio Resource Control (RRC) information. The radio resource control information includes, for example, information indicating that a packet has been transmitted in a grant-free manner. The information indicating that a packet has been transmitted in a grant-free manner is, for example, "ConfiguredGrantConfig" information.

[0024] The cooperation information may include, as information (bandwidth information) related to traffic volume, scheduling information (O-RAN (Open Radio Access Network) CTI (Cooperative transport interface)) (ITU-T G.989.3 Amd.3 G.suppl.66) of the wireless terminal 8. The scheduling information may be, for example, downlink control information (DCI).

[0025] The cooperation information may include, for example, information specified in the specification number "TS28.552" of the 3GPP (Third Generation Partnership Project). The information specified in the specification number "TS28.552" is, for example, information (session information) regarding the number of user terminals connected to the cell (UE active) and average throughput information of the user terminals.

[0026] The cooperation information may include, for example, information specified in 3GPP specification numbers "TS23.502 4.2.2" and "TS38.401." The information specified in specification numbers "TS23.502 4.2.2" and "TS38.401" is, for example, "Registration information" of the user equipment (UE Registration).

[0027] A packet transmitted in a grant-free manner is a packet (user data) transmitted from a wireless terminal 8 when a grant (permission to transmit) has not been notified to the wireless terminal 8. A packet transmitted in a grant-based manner is a packet (user data) transmitted from a wireless terminal 8 after a grant (permission to transmit) has been notified to the wireless terminal 8.

[0028] The signal transfer control device 4 updates the scheduling information of the signal transfer device 5 that transfers the packet depending on whether the packet was transmitted using the grant-free method or the grant-based method and the priority identifier (priority class) assigned to the packet.

[0029] When it is determined that a packet has been transmitted upstream in the grant-free mode, the signal transfer control device 4 may select a path (route) in the network based on information on the network topology of multiple signal transfer devices 5. The selected path is, for example, the shortest path (shortest route) between the central station 3 and the remote station 6.

[0030] The signal transfer control device 4 transmits a control signal representing the scheduling information to the signal transfer device 5 on the selected path. The signal transfer control device 4 may also transmit a control signal representing the selected path to the signal transfer device 5 on the selected path. When the signal transfer device 5 acquires the control signal representing the selected path, it configures the selected path itself. The control signal may include control information (e.g., "OpenConfig") of the physical port. The signal transfer control device 4 updates the scheduling information of the signal transfer device 5 using the control signal representing the scheduling information.

[0031] The communication system 1a may further include one or more signal transfer devices 5. The selected path may include multiple signal transfer devices 5. When the selected path includes multiple signal transfer devices 5, the signal transfer control device 4 transmits a control signal representing scheduling information to each signal transfer device 5 in the selected path. The signal transfer control device 4 may also transmit a control signal representing the selected path to each signal transfer device 5 in the selected path.

[0032] The signal forwarding device 5 is, for example, a Layer 2 switch. The signal forwarding device 5 acquires a control signal from the signal forwarding control device 4. Based on the scheduling information represented by the acquired control signal, the multiple signal forwarding devices 5 transfer signals (packets) between the central station 3 and the distributed stations 6 by, for example, TAS in TSN of the IEEE 802.1 standard. Based on the selected path represented by the acquired control signal, the multiple signal forwarding devices 5 may switch the path of the signal between the central station 3 and the distributed stations 6 to the selected path. As a result, packets transmitted in the grant-free mode are transferred via the path (for example, the shortest path) selected by the signal forwarding control device 4.

[0033] The remote station 6 communicates with one or more wireless terminals 8 (user terminals) via a wireless station 7. The remote station 6 acquires a wireless signal corresponding to uplink data from the wireless terminal 8. The remote station 6 transmits the signal corresponding to the uplink data to one or more signal transfer devices 5.

[0034] The remote station 6 transmits the cooperation information to the signal forwarding controller 4 at time intervals that are the scheduling units of the radio resources. For example, "O-RAN CTI" is known as an example of an interface in the mobile fronthaul. The remote station 6 may notify the signal forwarding controller 4 of the cooperation information using a CTI that is extended compared to such a CTI.

[0035] A radio station 7 (RU: Radio Unit) (gNB: next generation Node B) performs radio communication with a radio terminal 8. The radio terminal 8 (user terminal) (NR UE: New Radio User Equipment) is, for example, a mobile terminal or an IoT (Internet of Things) terminal. The radio terminal 8 transmits an uplink data signal to the remote station 6 via the radio station 7. This allows the radio terminal 8 to transmit the uplink data to the higher-level device 2. The radio terminal 8 acquires a downlink data signal from the remote station 6 via the radio station 7. This allows the radio terminal 8 to acquire the downlink data from the higher-level device 2.

[0036] 2 is a diagram showing an example of the configuration of the signal transfer control device 4 in the first embodiment. The signal transfer control device 4 includes an acquisition unit 41, an analysis unit 42, and a control unit 43. The analysis unit 42 includes a storage processing unit 421, a storage unit 422, a method determination unit 423, and a time estimation unit 424. The control unit 43 includes a transfer control unit 431 and a control signal transmission unit 432. The remote station 6 includes a notification processing unit 61.

[0037] The notification processing unit 61 notifies the acquisition unit 41 of the cooperation information in units of radio resource scheduling. The acquisition unit 41 acquires the cooperation information from the notification processing unit 61 in units of radio resource scheduling. The acquisition unit 41 outputs the cooperation information to the storage processing unit 421 every time it acquires the cooperation information.

[0038] The storage processing unit 421 records the notified link information in the storage unit 422. The storage processing unit 421 may associate the notified link information with the notification time and record them in the storage unit 422. For example, the storage processing unit 421 associates the notified link information with the notification time and records them in the storage unit 422 in the form of table information.

[0039] The storage processing unit 421 outputs the notified cooperation information to the scheme determination unit 423. The storage processing unit 421 may record the notified cooperation information in the storage unit 422. The storage unit 422 outputs the stored cooperation information to the storage processing unit 421 in response to an instruction from the storage processing unit 421. The storage processing unit 421 may store information on the network topology of a plurality of signal transfer devices 5.

[0040] The scheme determination unit 423 determines whether a packet has been transmitted in the grant-free scheme based on the cooperation information. For example, when the notification processing unit 61 notifies the scheme determination unit 423 of "ConfiguredGrantConfig" information, the scheme determination unit 423 determines that a signal has been transmitted in the grant-free scheme from the wireless terminal 8 associated with the remote station 6 of the notification processing unit 61. When the notification processing unit 61 does not notify the scheme determination unit 423 of "ConfiguredGrantConfig" information, the scheme determination unit 423 determines that a signal has been transmitted in the grant-based scheme from the wireless terminal 8 associated with the remote station 6 of the notification processing unit 61. The scheme determination unit 423 outputs the detection result of the transmission scheme to the transfer control unit 431.

[0041] When it is determined that the packet has been transmitted using the grant-free method, the method determination unit 423 may determine whether or not repeated transmission of the packet (transmission a predetermined number of times) is to be performed, based on the cooperation information. For example, when the remote station 6 notifies the remote station 6 using the cooperation information that the grant-free method is the "k-repetition" method, the method determination unit 423 determines that repeated transmission of the packet (transmission a predetermined number of times) is to be performed. The method determination unit 423 outputs the detection result of the transmission method to the transfer control unit 431. The method determination unit 423 may also output the detection result of the transmission method to the time estimation unit 424.

[0042] 3 is a diagram showing an example of time-series traffic volume related to the signal transfer device 5 in the first embodiment. The time estimation unit 424 estimates in advance the time (time period) during which packets are transmitted in the grant-free mode based on previously notified cooperation information. For example, the traffic volume of packets transmitted in the grant-free mode is greater than the traffic volume of packets transmitted in the grant-based mode. Therefore, during the time during which packets are transmitted in the grant-free mode, the traffic volume may increase compared to the time during which packets are transmitted in the grant-based mode.

[0043] Time "t1" is, for example, the time when the signal forwarding device 5 acquires the control signal transmitted from the signal forwarding control device 4. The intervals between the times illustrated in FIG. 3 are, for example, time intervals in radio resource scheduling units. In FIG. 3, the time estimation unit 424 estimates, for example, the time when the traffic volume is equal to or greater than a threshold (the time period from time "t2" to time "t4"). During the time when the traffic volume is equal to or greater than the threshold, packets may be transmitted in the grant-free mode. The time estimation unit 424 outputs the estimation result of such time (first time) to the forwarding control unit 431. A margin time length may be added to the length of the estimated time.

[0044] In addition, during the time period from time "t2" to time "t4" when the traffic volume exceeds the threshold, the time when the traffic volume actually exceeds the threshold may be a continuous period from time "t2" to time "t4", or may be periodic (discrete) times "t2", "t3", and "t4".

[0045] For example, when a packet is transmitted k times (e.g., three times) from the wireless terminal 8 using the "k-repetition" scheme, multiple packets (a number corresponding to the number of slots) arrive at the remote station 6 or the signal forwarding device 5 k times at a time interval (transmission time interval) of the scheduling unit of the wireless resource. Therefore, the time estimation unit 424 estimates the time (the time slot from time "t2" to time "t4") when multiple packets (a number corresponding to the number of slots) arrive k times at the remote station 6 or the signal forwarding device 5. The time estimation unit 424 outputs the estimation result of this time (second time) to the forwarding control unit 431. A margin time length may be added to the length of the estimated time. In FIG. 3, the traffic volume in the time slot from time "t5" to time "t6" is below a threshold, for example. During the time when the traffic volume is below the threshold, packets may be transmitted using the grant-based scheme.

[0046] Returning to FIG. 2, the description of the exemplary configuration of the signal transfer control device 4 continues. The transfer control unit 431 generates a control signal based on the network topology of multiple signal transfer devices 5, the detection result of the transmission method, and the estimation result of the transmission time (transmission time zone). When it is determined that a packet has been transmitted using the grant-based method, the transfer control unit 431 generates a control signal representing transfer scheduling information so that the signal transfer device 5 transfers the packet according to the high-priority identifier (priority class) assigned to the packet. The transfer control unit 431 outputs the control signal to the control signal transmission unit 432.

[0047] When it is determined that repeated packet transmission is not performed in the grant-free method, the transfer control unit 431 generates a control signal so that the signal transfer device 5 transfers packets that arrive at the signal transfer device 5 within a predetermined first time period (the time period from time "t2" to time "t4" illustrated in FIG. 3) according to the priority class. Packets may arrive periodically within the first time period. Furthermore, the first time period and the packet arrival period (pattern) may be derived in advance based on past coordination information, or may be derived in advance using machine learning, for example.

[0048] When it is determined that repeated packet transmission is to be performed in the grant-free method, the transfer control unit 431 generates a control signal so that the signal transfer device 5 transfers packets that arrive at the signal transfer device 5 within a predetermined second time (within the period of repeated transmission) according to the priority class. The second time may be a time different from the above-mentioned first time, or may be the same as the above-mentioned first time. During the second time (the time from time "t2" to time "t4" illustrated in FIG. 3), packets may arrive periodically. Furthermore, the second time and the packet arrival period (pattern) may be derived in advance based on past coordination information, for example, or may be derived in advance using machine learning.

[0049] When it is determined that a packet has been transmitted using the grant-based method, the transfer control unit 431 generates a control signal representing transfer scheduling information so that the signal transfer device 5 transfers the packet according to the priority identifier (priority class) assigned to the packet. The transfer control unit 431 outputs the control signal to the control signal transmission unit 432 at time "t1" illustrated in FIG.

[0050] The control signal transmitter 432 transmits a control signal to each signal forwarding device 5. In the signal forwarding device 5, the packet forwarding scheduling information is updated based on the control signal, thereby controlling the forwarding timing of high-priority packets.

[0051] Next, an example of the operation of the communication system 1a will be described. 4 is a flowchart showing an example of the operation of the signal transfer control device 4 in the first embodiment. The scheme determination unit 423 determines whether a packet has been transmitted from the wireless terminal 8 in the grant-free scheme based on the cooperation information (step S101).

[0052] If it is determined that the packet has been transmitted from the wireless terminal 8 using the grant-based method (step S101: NO), the transfer control unit 431 generates a control signal representing transfer scheduling information so that the signal transfer device 5 transfers the packet according to the priority identifier assigned to the packet (step S102). The transfer control unit 431 returns the process to step S101.

[0053] If it is determined that the packet has been transmitted from the wireless terminal 8 in the grant-free mode (step S101: YES), the transfer control unit 431 determines whether or not repeated transmission of the packet is to be performed based on the cooperation information (step S103).

[0054] If it is determined that repeated packet transmission is not to be performed (step S103: NO), the transfer control unit 431 generates a control signal so that the signal transfer device 5 transfers packets that arrive at the signal transfer device 5 within a first time period (a first length of time period) from the time the control signal is acquired by the signal transfer device 5, according to the priority identifier (step S104). The transfer control unit 431 returns the process to step S101.

[0055] If it is determined that repeated packet transmission is to be executed (step S103: YES), the transfer control unit 431 generates a control signal so that the signal transfer device 5 transfers packets that arrive at the signal transfer device 5 within a second time period (a second length of time) from the time the control signal is acquired by the signal transfer device 5, according to the priority identifier (step S105). The transfer control unit 431 returns the process to step S101.

[0056] As described above, the scheme determination unit 423 determines whether a packet assigned a priority identifier has been transmitted using the grant-free scheme. The time estimation unit 424 estimates the time at which the packet traffic volume will be equal to or greater than a threshold. The transfer control unit 431 generates a control signal for the signal transfer device 5 so that the signal transfer device 5 transfers packets that arrive at the signal transfer device at the estimated time according to the priority identifier.

[0057] The scheme determination unit 423 may determine whether or not repeated packet transmission is to be performed. If it is determined that repeated packet transmission is to be performed, the time estimation unit 424 may estimate the time it takes for multiple packets (e.g., a number equivalent to the number of slots) to arrive at the signal forwarding device 5 a predetermined number of times at predetermined time intervals.

[0058] This makes it possible to suppress an increase in delay time for packets that have been assigned a high-priority identifier.

[0059] (Second embodiment) The second embodiment differs from the first embodiment in that a distributed station control device that controls a distributed station 6 transmits radio resource control information to the signal transfer control device 4. The second embodiment will be described focusing on the differences from the first embodiment.

[0060] 5 is a diagram showing an example of the configuration of a communication system 1b in the second embodiment. The communication system 1b includes a higher-level device 2, a central station 3, a signal transfer control device 4, N signal transfer devices 5, M distributed stations 6, M wireless stations 7, and a distributed station control device 9. One or more wireless terminals 8 can be communicatively connected to the wireless station 7 associated with the distributed station 6.

[0061] The remote station 6 transmits cooperation information to the remote station control device 9 at time intervals of the radio resource scheduling unit. The remote station control device 9 (cooperation information transfer device) transmits cooperation information to the signal transfer control device 4 at time intervals of the radio resource scheduling unit. The remote station control device 9 may control the operation of the remote station 6. The signal transfer control device 4 acquires the cooperation information from the remote station control device 9.

[0062] 6 is a diagram showing an example of the configuration of the signal transfer control device 4 in the second embodiment. The notification processing unit 61 notifies the distributed station control device 9 of cooperation information at time intervals corresponding to the scheduling unit of radio resources. The distributed station control device 9 transmits the cooperation information of each distributed station 6 to the acquisition unit 41 at time intervals corresponding to the scheduling unit of radio resources. The acquisition unit 41 acquires the cooperation information from the distributed station control device 9.

[0063] As described above, the distributed station control device 9 transmits the cooperation information of each distributed station 6 to the acquisition unit 41 at time intervals of radio resource scheduling units. This makes it possible to suppress an increase in the delay time of packets assigned with high-priority identifiers, even if each distributed station 6 does not notify the signal transfer control device 4 of the cooperation information.

[0064] (Example of hardware configuration) FIG. 7 is a diagram illustrating an example of the hardware configuration of the signal transfer control device 4 in each embodiment. Some or all of the functional units of the signal transfer control device 4 are realized as software by a processor 101, such as a CPU (Central Processing Unit), executing programs stored in a storage device 102 having a non-volatile recording medium (non-transitory recording medium) and a storage unit 103. The programs may be recorded on a computer-readable non-transitory recording medium. Examples of computer-readable non-transitory recording media include portable media such as flexible disks, magnetic disks, ROMs (Read Only Memory), and CD-ROMs (Compact Disc Read Only Memory), and storage devices such as hard disks built into computer systems. A communication unit 104 executes predetermined communication processing. The communication unit 104 may acquire data and programs.

[0065] Some or all of the functional units of the signal transfer control device 4 may be realized using hardware including electronic circuits (electronic circuits or circuitry) using, for example, an LSI (Large Scale Integrated circuit), an ASIC (Application Specific Integrated Circuit), a PLD (Programmable Logic Device), or an FPGA (Field Programmable Gate Array).

[0066] 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 gist of the present invention. [Industrial Applicability]

[0067] The present invention is applicable to communication systems that use switch networks. [Explanation of symbols]

[0068] 1a, 1b...communication system, 2...higher-level device, 3...central station, 4...signal transfer control device, 5...signal transfer device, 6...distributed station, 7...wireless station, 8...wireless terminal, 9...distributed station control device, 41...acquisition unit, 42...analysis unit, 43...control unit, 61...notification processing unit, 101...processor, 102...storage device, 103...storage unit, 104...communication unit, 421...storage processing unit, 422...storage unit, 423...scheme determination unit, 424...time estimation unit, 431...transfer control unit, 432...control signal transmission unit

Claims

1. a method determination unit that determines whether a packet to which a priority identifier is assigned is transmitted by a grant-free method, and, when it is determined that the packet is transmitted by the grant-free method, determines whether repeated transmission of the packet is to be performed; a time estimation unit that, when it is determined that repeated transmission of the packets will not be performed, estimates a first time period during which a traffic volume of the packets will be equal to or greater than a threshold, and, when it is determined that repeated transmission of the packets will be performed, estimates a second time period during which a plurality of the packets will arrive at the signal transfer device a predetermined number of times at predetermined time intervals; a transfer control unit that generates a control signal for the signal transfer device so that the signal transfer device transfers the packet that arrived at the signal transfer device in accordance with the priority identifier when it is determined that the packet will not be transmitted in a grant-free manner, generates a control signal for the signal transfer device so that the signal transfer device transfers the packet that arrived at the signal transfer device in the estimated first time in accordance with the priority identifier when it is determined that repeated transmission of the packet will not be executed, and generates a control signal for the signal transfer device so that the signal transfer device transfers the packet that arrived at the signal transfer device in the estimated second time in accordance with the priority identifier when it is determined that repeated transmission of the packet will be executed; A control device comprising:

2. A communication system comprising a signal forwarding device that forwards packets and a control device, The control device a method determination unit that determines whether the packet to which a priority identifier is assigned is transmitted by a grant-free method, and, if it is determined that the packet is transmitted by the grant-free method, determines whether repeated transmission of the packet is to be performed; a time estimation unit that, when it is determined that repeated transmission of the packets will not be performed, estimates a first time period during which a traffic volume of the packets will be equal to or greater than a threshold, and, when it is determined that repeated transmission of the packets will be performed, estimates a second time period during which a plurality of the packets will arrive at the signal transfer device a predetermined number of times at predetermined time intervals; a transfer control unit that generates a control signal for the signal transfer device so that the signal transfer device transfers the packet that arrived at the signal transfer device in accordance with the priority identifier when it is determined that the packet will not be transmitted in a grant-free manner, generates a control signal for the signal transfer device so that the signal transfer device transfers the packet that arrived at the signal transfer device in the estimated first time in accordance with the priority identifier when it is determined that repeated transmission of the packet will not be performed, and generates a control signal for the signal transfer device so that the signal transfer device transfers the packet that arrived at the signal transfer device in the estimated second time in accordance with the priority identifier when it is determined that repeated transmission of the packet will be performed Communication system.

3. A control method executed by a control device, a method determination step of determining whether a packet to which a priority identifier is assigned is transmitted in a grant-free manner, and if it is determined that the packet is transmitted in a grant-free manner, determining whether repeated transmission of the packet is to be performed; a time estimation step of estimating a first time period during which the traffic volume of the packets will be equal to or greater than a threshold value when it is determined that the repeated transmission of the packets will not be performed, and estimating a second time period during which the plurality of packets will arrive at the signal transfer device a predetermined number of times at predetermined time intervals when it is determined that the repeated transmission of the packets will be performed; a transfer control step of generating a control signal for the signal transfer device so that the signal transfer device transfers the packet that arrived at the signal transfer device in accordance with the priority identifier when it is determined that the packet will not be transmitted in a grant-free manner, generating a control signal for the signal transfer device so that the signal transfer device transfers the packet that arrived at the signal transfer device in the estimated first time in accordance with the priority identifier when it is determined that repeated transmission of the packet will not be performed, and generating a control signal for the signal transfer device so that the signal transfer device transfers the packet that arrived at the signal transfer device in the estimated second time in accordance with the priority identifier when it is determined that repeated transmission of the packet will be performed; A control method comprising:

4. A program for causing a computer to function as the control device according to claim 1.

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