Communication control system, communication control method, and program

Abstract

SOLUTION: The communication control device is provided in a mobile object. The communication control device includes a communication processing unit configured to perform processing for transmitting a packet transmitted from a communication device through a wireless communication unit provided in the mobile object, a detection unit configured to detect that a communication state in a communication path through the wireless communication unit has become poor, and a control unit configured to perform control for transmitting an RST packet to the communication device when it is detected that the communication state has become poor. The communication control method includes a step of performing control for transmitting a packet transmitted from a communication device through a wireless communication unit provided in the moving object, a step of detecting that a communication state in a communication path through the wireless communication unit has become poor, and a step of performing control for transmitting an RST packet to the communication device when it is detected that the communication state has become poor.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Patent Documents 1 to 3 describe techniques relating to RST packets. [Prior art document] [Patent documents] Patent Document 1: JP 2016-63485 A Patent Document 2: JP 2023-33553 A Patent Document 3: International Publication No. 2015 / 52917 Summary of the Invention [Problem to be solved by the invention]

[0003] However, when a communication device communicates with the outside world through a wireless communication unit installed in a mobile object, the communication device does not know the communication status of the wireless communication unit, and therefore there is a problem that the communication device performs wasteful processing such as resending packets that did not arrive. In order to solve the above problem, the present application aims to suppress wasteful processing in wireless communication, and ultimately contribute to the development of sustainable transportation systems. [Means for solving the problem]

[0004] A first aspect of the present invention provides a communication control device. The communication control device is provided in a mobile body. The communication control device includes a communication processing unit that performs processing to transmit packets sent from a communication device through a wireless communication unit provided in the mobile body. The communication control device includes a detection unit that detects that a communication state in a communication path through the wireless communication unit has become poor. The communication control device includes a control unit that performs control to transmit a RST packet to the communication device when it is detected that the communication state has become poor.

[0005] In the above-mentioned communication control device, the control unit may start a process of discarding packets from the communication device that are to be transmitted through the wireless communication unit when predetermined conditions are met after a RST packet is transmitted to the communication device.

[0006] In any of the above communication control devices, the control unit may repeatedly transmit a RST packet to the communication device until the predetermined condition is satisfied.

[0007] In any of the above communication control devices, the predetermined condition may include that the number of times a RST packet has been transmitted to the communication device exceeds a predetermined number.

[0008] In any of the above communication control devices, the predetermined condition may include a condition that a time period during which a RST packet has been repeatedly transmitted to the communication device exceeds a predetermined time period.

[0009] Any of the above communication control devices may include a storage unit that stores a transmission history of RST packets to the communication device, and the control unit may determine whether to transmit a RST packet or discard a packet from the communication device that is to be transmitted through the wireless communication unit, based on the transmission history of the RST packets stored in the storage unit.

[0010] In any of the above communication control devices, the wireless communication unit may include a cellular communication unit that performs cellular communication and a wireless LAN communication unit that performs wireless LAN communication, and the detection unit may detect that a communication state in a communication path through the cellular communication unit has become poor and that a communication state in a communication path through the wireless LAN communication unit has become poor. The control unit may perform control to transmit a RST packet to the communication device when it is detected that a communication state in a communication path through the cellular communication unit has become poor.The control unit may perform control to transmit a RST packet to the communication device when it is detected that a communication state in a communication path through the wireless LAN communication unit has become poor.

[0011] In any of the above communication control devices, the moving body may be a vehicle, and the communication device may be an ECU.

[0012] In a second aspect of the present invention, there is provided a communication control method. The communication control method is executed in a communication control device provided in a mobile body. The communication control method includes a step of performing control to transmit packets transmitted from a communication device through a wireless communication unit provided in the mobile body. The communication control method includes a step of detecting that a communication state in a communication path through the wireless communication unit has become poor. The communication control method includes a step of performing control to transmit a RST packet to the communication device when it is detected that the communication state has become poor.

[0013] In a third aspect of the present invention, there is provided a program. The program causes a computer to function as any one of the communication control devices described above. The program may be stored in a non-transitory computer-readable storage medium.

[0014] The above summary of the invention does not list all of the features of the present invention, and subcombinations of these features may also constitute inventions. [Brief explanation of the drawings]

[0015] [Figure 1] 1 shows a schematic configuration of a communication system 22 according to an embodiment. [Figure 2] 2 shows an example of a system configuration of a communication system 22. [Figure 3]1 shows an example of a sequence relating to a communication control method executed in the communication system 22. [Figure 4] 10 shows a transmission history of RST packets stored in the storage unit 230. [Figure 5] 10 shows an example of a flowchart relating to a communication control method executed in a communication control unit 33. [Figure 6] An example of a computer 2000 is shown. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention will be described below through embodiments of the invention, but the following embodiments do not limit the scope of the invention according to the claims. Furthermore, not all of the combinations of features described in the embodiments are necessarily essential to the solution of the invention.

[0017] 1 is a schematic diagram illustrating a configuration of a communication system 22 according to an embodiment. The communication system 22 is provided in a mobile object 20.

[0018] The mobile object 20 is a mobile device. The mobile object 20 is, for example, a vehicle such as a bus or a train. A vehicle is an example of transportation equipment. The mobile object 20 may be various types of aircraft, including unmanned aerial vehicles.

[0019] The communication system 22 has the function of performing cellular communication and wireless LAN communication. The communication system 22 can communicate with communication devices connected to a communication network 90 via a wireless relay device 110 and a wireless base station 120. The communication network 90 includes a computer network such as the Internet, a cellular communication network, and the like.

[0020] The wireless base station 120 is a cellular communication base station that supports one or more cellular communication methods. The cellular communication methods supported by the wireless base station 120 may be, for example, communication methods used in mobile communication systems such as the fourth generation mobile communication system (4G) and the fifth generation mobile communication system (5G). The wireless base station 120 relays communication between a communication device in the communication system 22 and a communication device connected to the communication network 90.

[0021] The wireless relay device 110 has a function of relaying wireless LAN communications. For example, the wireless relay device 110 has a wireless LAN access point function. The wireless relay device 110 relays communications between a communication device in the communication system 22 and a communication device connected to the communication network 90.

[0022] In this embodiment, the mobile object 20 is a vehicle, and the communication system 22 includes a communication network and a plurality of communication devices connected to the communication network. The plurality of communication devices are, for example, ECUs (electronic control units) provided in the vehicle.

[0023] The communication system 22 has a wireless communication unit that can be wirelessly connected to the wireless relay device 110 and / or the wireless base station 120. The ECU in the communication system 22 can communicate with communication devices connected to the communication network 90 through the wireless communication unit.

[0024] When an ECU in the communication system 22 is wirelessly communicating with the outside world through a wireless communication unit, if the communication state of the communication path through the wireless communication unit becomes poor, a packet will not be delivered. In this case, the communication system 22 transmits a RST packet to the ECU. Upon receiving the RST packet, the ECU stops communication through the wireless communication unit. This prevents the ECU from continuing to retransmit the failed packet.

[0025] The communication terminal 100 is a terminal carried by a passenger of the mobile object 20. The communication terminal 100 is, for example, a mobile terminal such as a smartphone. The communication terminal 100 can wirelessly communicate with the outside through a wireless communication unit in the communication system 22.

[0026] When the communication terminal 100 is communicating wirelessly with the outside world through a wireless communication unit in the communication system 22, if the communication state of the communication path through the wireless communication unit becomes poor, the communication system 22 transmits a RST packet to the communication terminal 100. When the communication terminal 100 receives the RST packet, it stops communication through the wireless communication unit. This prevents the communication terminal 100 from continuing to retransmit packets that have not been delivered.

[0027] In this way, according to the communication system 22, if the external communication state becomes poor while the ECU and the communication terminal 100 are wirelessly communicating with the outside through a wireless communication unit in the communication system 22, the ECU and the communication terminal 100 receive a RST packet from the communication system 22, so that it is possible to prevent the ECU and the communication terminal 100 from continuing to perform useless processing such as retransmitting packets. Furthermore, if the ECU and the communication terminal 100 receive a RST packet while performing wireless LAN communication via the wireless relay device 110, for example, it becomes possible to switch to cellular communication and perform data communication.

[0028] 2 schematically illustrates an example of a system configuration of the communication system 22. The communication system 22 includes a TCU 30, an in-vehicle communication network 70, and a plurality of ECUs including one or more ECUs 50. The in-vehicle communication network 70 includes, for example, an Ethernet bus and an Ethernet hub.

[0029] The TCU 30 is a telematics control unit. The TCU 30 includes a communication control unit 33 and a wireless communication unit 34. The wireless communication unit 34 includes a cellular communication unit 31 and a wireless LAN communication unit 32. The cellular communication unit 31 performs cellular communication. The wireless LAN communication unit 32 performs wireless LAN communication.

[0030] The communication control unit 33 is responsible for overall control of the TCU 30. The communication control unit 33 is an example of a communication control device. At least a part of the communication control unit 33 is realized by an arithmetic processing unit including a processor. The communication control unit 33 may be realized by a computer including a CPU, ROM, RAM, I / O, buses, etc.

[0031] The communication control unit 33 includes a communication processing unit 200 , a detection unit 210 , a control unit 220 , and a storage unit 230 .

[0032] The communication processing unit 200 performs processing for transmitting packets transmitted from the ECU 50 via the wireless communication unit 34 provided in the mobile object 20. The detection unit 210 detects that the communication state in the communication path via the wireless communication unit 34 has become poor. For example, the detection unit 210 detects that the communication state has become poor based on the length of the round trip time (RTT), the frequency of PDN session disconnections, etc. In this way, the detection unit 210 may detect a poor state of IP communication instead of detecting a poor wireless state such as RSSI.

[0033] When it is detected that the communication state of a communication path via the wireless communication unit 34 has become poor, the control unit 220 performs control to transmit an RST packet to the ECU 50. The RST packet is transmitted for each communication path for which a poor communication state has been detected.

[0034] When the ECU 50 communicates with the outside of the mobile object 20 through the wireless communication unit 34, if the communication path beyond the wireless communication unit 34 becomes faulty for some reason, the ECU 50 cannot check the external situation and therefore attempts to resend data even if communication is interrupted. However, in this embodiment, the TCU 30 transmits an RST packet to the ECU 50, so that the ECU 50, upon receiving the RST packet, can recognize the end of communication. This makes it possible to prevent the ECU 50 from resending packets.

[0035] When a predetermined condition is satisfied after an RST packet is transmitted to the ECU 50, the control unit 220 starts a process (also called a DROP process) of discarding a packet from the ECU 50 that is to be transmitted through the wireless communication unit 34. Depending on the settings or implementation of the ECU 50, even if the ECU 50 transmits an RST packet, the ECU 50 may not stop retransmission of the packet. Therefore, by having the control unit 220 start the DROP process when a predetermined condition is satisfied after the RST packet is transmitted, it is possible to prevent the RST packet from being transmitted to the ECU 50 multiple times.

[0036] The control unit 220 may repeatedly transmit an RST packet to the ECU 50 until a predetermined condition is satisfied. Here, the predetermined condition may include the number of times that the RST packet has been transmitted to the ECU 50 exceeding a predetermined number. The predetermined condition may include the time that the RST packet has been repeatedly transmitted to the ECU 50 exceeding a predetermined time. This makes it possible to discard packets from the ECU 50 that are highly likely not to correspond to the RST packet.

[0037] The storage unit 230 stores a transmission history of RST packets to the ECU 50. The control unit 220 determines, based on the transmission history of RST packets stored in the storage unit, whether to transmit an RST packet or to discard a packet from the ECU 50 that should be transmitted via the wireless communication unit 34. In this way, the control unit 220 determines, taking into account the transmission history of RST packets to the ECU 50, whether to transmit an RST packet or to discard a packet from the ECU 50. For example, when the control unit 220 determines, based on the transmission history of RST packets, to discard a packet from the ECU 50, the control unit 220 may discard the packet from the ECU 50 without transmitting the RST packet multiple times to the ECU 50. This makes it possible to quickly discard a packet from the ECU 50 that is highly likely not to correspond to the RST packet. This reduces the load imposed by the process of transmitting an RST packet.

[0038] The detection unit 210 detects that the communication state on the communication path through the cellular communication unit 31 has become poor. The control unit 220 performs control to transmit an RST packet to the ECU 50 when it is detected that the communication state on the communication path through the cellular communication unit 31 has become poor. The detection unit 210 detects that the communication state on the communication path through the wireless LAN communication unit 32 has become poor. The control unit 220 performs control to transmit an RST packet to the ECU 50 when it is detected that the communication state on the communication path through the wireless LAN communication unit 32 has become poor.

[0039] With reference to FIG. 2 , the ECU 50 has been described as an example of a communication device. However, the communication terminal 100 is also an example of a communication device to which a RST packet is sent. Specifically, in the TCU 30, the wireless LAN communication unit 32 has a wireless access point function. This allows the communication terminal 100 to connect to the wireless LAN communication unit 32 as a station, and the communication processing unit 200 transmits packets received from the communication terminal 100 to the outside via the wireless communication unit 34 (i.e., the cellular communication unit 31 and / or the wireless communication unit 34). This allows the communication terminal 100 to communicate with communication devices connected to the communication network 90 by connecting to the TCU 30 via the wireless LAN communication unit 32. In this case, the control unit 220 may perform control to transmit a RST packet to the communication terminal 100 when it is detected that the communication state has become poor.

[0040] 3 shows an example of a sequence relating to a communication control method executed in the communication system 22. In S302, the ECU 50 transmits a packet to be transmitted outside the mobile object 20 to the communication control unit 33. In the communication control unit 33, the communication processing unit 200 receives the packet transmitted from the ECU 50 and outputs the received packet to the wireless communication unit 34 (S304). The wireless communication unit 34 transmits the packet acquired from the communication processing unit 200 (S306).

[0041] Thereafter, in S310, the detection unit 210 detects a poor communication state on a communication path along which the ECU 50 transmits packets via the wireless communication unit 34. In S314, the control unit 220 performs control to transmit an RST packet to the ECU 50 (S314). After transmitting the RST packet in S314, the control unit 220 receives from the ECU 50 a packet to be transmitted on the communication path along which the poor communication state has been detected (S322), and then performs control to discard the packet (S324). The packet may be discarded when the number of times that the control unit 220 has received a packet to be transmitted on the communication path along which the poor communication state has been detected exceeds a predetermined number.

[0042] 4 shows the transmission history of RST packets stored in the storage unit 230. The transmission history of RST packets associates the communication device ID with the average number of times the RST packet is transmitted.

[0043] The communication device ID is information that uniquely identifies the ECU 50 and the communication terminal 100. The communication device ID may be, for example, a MAC address. For a communication device that can be identified by an IP address, the communication device ID may be an IP address. The average number of RST packet transmissions is the average number of times a RST packet is transmitted to a corresponding communication device after a communication failure on the communication path is detected.

[0044] When a poor communication state is detected on a communication path, the control unit 220 identifies a communication device communicating on the communication path. The control unit 220 references the transmission history of RST packets and acquires the average number of RST packet transmissions associated with the identification information of the communication device communicating on the communication path. If the acquired average number of RST packet transmissions is less than a predetermined value, the control unit 220 determines to transmit a RST packet. On the other hand, if the acquired average number of RST transmissions is equal to or greater than the predetermined value, the control unit 220 determines not to transmit a RST packet and to perform DROP processing.

[0045] 4 shows an example in which the average number of RST packet transmissions is stored as the RST packet transmission history, but the average number of RST packet transmissions is one example of the RST packet transmission history. As another example, the average value of the length of the period during which RST packets are repeatedly transmitted may be stored as the RST packet transmission history. Furthermore, the RST packet transmission history may include a history of the number of times RST packets are transmitted, or may include a history of the length of the period during which RST packets are repeatedly transmitted.

[0046] FIG. 5 shows an example of a flowchart relating to a communication control method executed in the communication control unit 33.

[0047] In S402, the control unit 220 determines whether or not a poor communication state has been detected by the detection unit 210. If it is determined that a poor communication state has been detected, then in S404, it determines whether to send a RST packet to a communication device communicating on a communication path on which the poor communication state has been detected, or to perform a DROP process on packets from that communication device. For example, as described in relation to FIG. 4, the control unit 220 may determine whether to send a RST packet to that communication device or to perform a DROP process on packets from that communication device based on the RST packet transmission history. If it is determined in S404 that a DROP process should be performed, the process proceeds to S410.

[0048] If it is determined in S404 that a RST packet should be transmitted, the RST packet is transmitted to the communication device in S406. In S408, the control unit 220 determines whether to initiate DROP processing. For example, the control unit 220 may determine to initiate DROP processing when the number of times that a RST packet has been transmitted after a poor communication state has been detected exceeds a predetermined number of times. The control unit 220 may determine to initiate DROP processing when the time that RST packets have been repeatedly transmitted after a poor communication state has been detected exceeds a predetermined time.

[0049] If it is determined in S408 that the DROP process should not be initiated, the process proceeds to S414. In S414, the control unit 220 determines whether or not a packet to be transmitted to a communication path in which a poor communication state has been detected has been received within a predetermined period from the communication device that transmitted the RST packet. If it is determined in S414 that a packet to be transmitted to a communication path in which a poor communication state has been detected has been received within a predetermined period, the process proceeds to S406. If it is determined that a packet to be transmitted to a communication path in which a poor communication state has been detected has not been received within a predetermined period, the process proceeds to S412.

[0050] If it is determined in S408 that the DROP process should be started, the DROP process is started in S410. Subsequently, in S412, the control unit 220 updates the transmission history of the RST packet stored in the storage unit 230, and ends the process of this flowchart.

[0051] If it is determined in S402 that a packet has not been received, it is determined in S414 whether a packet has been received within a predetermined period on the communication path on which the poor communication state has been detected. If it is determined in S414 that a packet has been received within a predetermined period on the communication path on which the poor communication state has been detected, the process returns to S402. If it is determined in S414 that a packet has not been received within a predetermined period on the communication path on which the poor communication state has been detected, the process returns to S412.

[0052] As described above, according to the TCU 30 of this embodiment, when the communication state becomes poor, a RST packet is transmitted to the communication device communicating through the communication path where the communication state has become poor, thereby preventing the communication device from continuing to perform useless processing such as packet retransmission processing, etc. Furthermore, for example, when a communication device is communicating through the wireless relay device 110 and receives a RST packet, it becomes possible to switch to cellular communication through the wireless base station 120 and perform data communication.

[0053] 6 shows an example of a computer 2000 in which multiple embodiments of the present invention may be embodied in whole or in part. A program installed on the computer 2000 may cause the computer 2000 to function as the communication system 22 according to an embodiment, or each part of the system, or various devices such as the TCU 30, or each part of the devices, perform operations associated with the system, each part of the system, or each device, and / or perform processes or steps of the processes according to an embodiment. Such programs may be executed by the CPU 2012 to cause the computer 2000 to perform specific operations associated with some or all of the processing procedures and block diagram blocks described herein.

[0054] The computer 2000 according to this embodiment includes a CPU 2012 and a RAM 2014, which are interconnected by a host controller 2010. The computer 2000 also includes a ROM 2026, a flash memory 2024, a communication interface 2022, and an input / output chip 2040. The ROM 2026, the flash memory 2024, the communication interface 2022, and the input / output chip 2040 are connected to the host controller 2010 via the input / output controller 2020.

[0055] The CPU 2012 operates according to programs stored in the ROM 2026 and RAM 2014, thereby controlling each unit.

[0056] The communication interface 2022 communicates with other electronic devices via a network. The flash memory 2024 stores programs and data used by the CPU 2012 in the computer 2000. The ROM 2026 stores a boot program and the like executed by the computer 2000 upon activation, and / or programs dependent on the hardware of the computer 2000. The input / output chip 2040 may also connect various input / output units such as a keyboard, mouse, and monitor to the input / output controller 2020 via input / output ports such as a serial port, a parallel port, a keyboard port, a mouse port, a monitor port, a USB port, an HDMI (registered trademark) port, etc.

[0057] The programs are provided via a computer-readable storage medium such as a CD-ROM, a DVD-ROM, or a memory card, or via a network. The RAM 2014, the ROM 2026, or the flash memory 2024 are examples of computer-readable storage media. The programs are installed in the flash memory 2024, the RAM 2014, or the ROM 2026 and executed by the CPU 2012. Information processing described in these programs is read by the computer 2000, and causes cooperation between the programs and the various types of hardware resources described above. An apparatus or a method may be configured by implementing operations or processing of information in accordance with the use of the computer 2000.

[0058] For example, when communication is performed between the computer 2000 and an external device, the CPU 2012 may execute a communication program loaded into the RAM 2014 and instruct the communication interface 2022 to perform communication processing based on the processing described in the communication program. Under the control of the CPU 2012, the communication interface 2022 reads transmission data stored in a transmission buffer processing area provided in a recording medium such as the RAM 2014 or flash memory 2024, transmits the read transmission data to a network, and writes received data received from the network to a reception buffer processing area or the like provided on the recording medium.

[0059] The CPU 2012 may also cause all or a necessary portion of a file or database stored on a recording medium such as the flash memory 2024 to be read into the RAM 2014, and perform various types of processing on the data on the RAM 2014. The CPU 2012 then writes the processed data back to the recording medium.

[0060] Various types of information, such as various types of programs, data, tables, and databases, may be stored on the recording medium and subjected to information processing. The CPU 2012 may perform various types of processing on data read from the RAM 2014, including various types of operations, information processing, conditional judgment, conditional branching, unconditional branching, information search / replacement, etc., as described herein and specified by the instruction sequences of the programs, and write the results back to the RAM 2014. The CPU 2012 may also search for information in a file, database, etc. on the recording medium. For example, if multiple entries each having an attribute value of a first attribute associated with an attribute value of a second attribute are stored on the recording medium, the CPU 2012 may search for an entry that matches a condition specified by the attribute value of the first attribute from among the multiple entries, read the attribute value of the second attribute stored in the entry, and thereby obtain the attribute value of the second attribute associated with the first attribute that satisfies a predetermined condition.

[0061] The above-described programs or software modules may be stored in a computer-readable storage medium on or near the computer 2000. A recording medium such as a hard disk or RAM provided in a server system connected to a dedicated communication network or the Internet can be used as the computer-readable storage medium. The programs stored in the computer-readable storage medium may be provided to the computer 2000 via a network.

[0062] A program installed in computer 2000 and causing computer 2000 to function as TCU 30 may, when executed by the computer, act on CPU 2012, etc., to cause computer 2000 to function as each unit of TCU 30. When the information processing described in these programs is loaded into computer 2000, computer 2000 functions as each unit of TCU 30, which is a specific means formed by software and the various hardware resources described above working together. These specific means then perform calculations or processing of information according to the intended use of computer 2000 in this embodiment, thereby constructing a specific TCU 30 according to the intended use.

[0063] Various embodiments have been described with reference to block diagrams. In the block diagrams, each block may represent (1) a stage of a process where an operation is performed or (2) a portion of an apparatus responsible for performing the operation. Particular stages and portions may be implemented by dedicated circuitry, programmable circuitry provided with computer-readable instructions stored on a computer-readable storage medium, and / or a processor provided with computer-readable instructions stored on a computer-readable storage medium. Dedicated circuitry may include digital and / or analog hardware circuitry, and may include integrated circuits (ICs) and / or discrete circuits. Programmable circuitry may include reconfigurable hardware circuitry including logical AND, logical OR, logical XOR, logical NAND, logical NOR, and other logic operations, flip-flops, registers, memory elements such as field programmable gate arrays (FPGAs), programmable logic arrays (PLAs), and the like.

[0064] A computer-readable storage medium may include any tangible device capable of storing instructions that are executed by an appropriate device, such that the computer-readable storage medium with instructions stored thereon constitutes at least a portion of an article of manufacture containing instructions that can be executed to provide means for performing the operations specified in a process or block diagram. Examples of computer-readable storage media may include electronic storage media, magnetic storage media, optical storage media, electromagnetic storage media, semiconductor storage media, etc. More specific examples of computer-readable storage media may include floppy disks, diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), electrically erasable programmable read-only memory (EEPROM), static random access memory (SRAM), compact disc read-only memory (CD-ROM), digital versatile disc (DVD), Blu-ray disc, memory stick, integrated circuit card, etc.

[0065] The computer readable instructions may include either assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source or object code written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Smalltalk®, JAVA®, C++, etc., and conventional procedural programming languages ​​such as the “C” programming language or similar programming languages.

[0066] The computer-readable instructions may be provided to a processor or programmable circuitry of a programmable data processing apparatus, such as a computer, locally or over a local area network (LAN), a wide area network (WAN) such as the Internet, etc., and the computer-readable instructions may be executed to provide means for performing the operations specified in the described procedures or block diagrams.

[0067] Here, the computer may be a computer such as a PC (personal computer), tablet computer, smartphone, workstation, server computer, or general-purpose computer, or may be a computer system in which multiple computers are connected. Such a computer system in which multiple computers are connected is also called a distributed computing system, and is a computer in the broad sense. In a distributed computing system, the multiple computers collectively execute a program by each executing a part of the program and passing data between the computers as needed during program execution.

[0068] Examples of processors include computer processors, central processing units (CPUs), processing units, microprocessors, digital signal processors, controllers, microcontrollers, etc. A computer may have one or more processors. In a multiprocessor system with multiple processors, each processor executes a portion of a program and passes data between processors as needed during program execution, allowing the multiple processors to collectively execute the program. For example, in multitasking, each of the multiple processors may execute a portion of each task in small chunks by switching tasks at time slice intervals. In this case, which portion of a program each processor executes changes dynamically. Alternatively, which portion of a program each of the multiple processors executes may be statically determined by multiprocessor-aware programming.

[0069] Although the present invention has been described above using embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

[0070] It should be noted that the execution order of each process, such as operations, procedures, steps, and stages, in the devices, systems, programs, and methods shown in the claims, specifications, and drawings is not specifically stated as "before," "prior to," etc., and that the processes can be performed in any order unless the output of a previous process is used in a subsequent process. Even if the operational flow in the claims, specifications, and drawings is described using "first," "next," etc. for convenience, this does not mean that the processes must be performed in this order. [Explanation of symbols]

[0071] 20 Mobile 22 Communication Systems 30 TCU 31 Cellular Communications Department 32 Wireless LAN communication section 33 Communication control section 34 Radio Communication Department 50 ECU 70 In-vehicle communication network 90 Communication Network 100 communication terminal 110 Radio repeater 120 wireless base stations 200 Communication processing unit 210 Detector 220 Control Unit 230 Storage section 2000 Computer 2010 Host Controller 2012 CPU 2014 RAM 2020 Input / Output Controller 2022 Communication Interface 2024 flash memory 2026 ROM 2040 Input / Output Chip

Claims

1. A communication control device provided in a mobile object, a communication processing unit that performs processing for transmitting packets transmitted from a communication device through a wireless communication unit provided in the mobile object; a detection unit that detects that a communication state in a communication path through the wireless communication unit has become poor; a control unit that performs control to transmit an RST packet to the communication device when it is detected that the communication state has become poor; A communication control device comprising:

2. The control unit starts a process of discarding a packet from the communication device that is to be transmitted through the wireless communication unit when a predetermined condition is satisfied after the RST packet is transmitted to the communication device. The communication control device according to claim 1 .

3. The control unit repeatedly transmits an RST packet to the communication device until the predetermined condition is satisfied. The communication control device according to claim 2 .

4. The predetermined condition includes that the number of times that an RST packet has been transmitted to the communication device exceeds a predetermined number. The communication control device according to claim 3 .

5. The predetermined condition includes a time period during which the RST packet has been repeatedly transmitted to the communication device exceeding a predetermined time period. The communication control device according to claim 3 .

6. a storage unit for storing a history of RST packet transmissions to the communication device; Furthermore, The control unit determines whether to transmit an RST packet or discard a packet from the communication device that is to be transmitted through the wireless communication unit, based on a transmission history of the RST packet stored in the storage unit. The communication control device according to claim 1 .

7. the wireless communication unit includes a cellular communication unit that performs cellular communication and a wireless LAN communication unit that performs wireless LAN communication; the detection unit detects that a communication state in a communication path through the cellular communication unit has become poor and that a communication state in a communication path through the wireless LAN communication unit has become poor; The control unit When it is detected that a communication state in a communication path through the cellular communication unit has become poor, control is performed to transmit an RST packet to the communication device; When it is detected that the communication state in the communication path through the wireless LAN communication unit has become poor, control is performed to transmit an RST packet to the communication device. The communication control device according to claim 1 .

8. the moving body is a vehicle, The communication device is an ECU The communication control device according to claim 1 .

9. A communication control method executed in a communication control device provided in a mobile object, comprising: a step of controlling the transmission of packets from a communication device through a wireless communication unit provided in the mobile object; detecting that a communication state in a communication path via the wireless communication unit has become poor; a step of controlling the communication device to transmit an RST packet when it is detected that the communication state has become poor; A communication control method comprising:

10. A program for causing a computer to function as the communication control device according to any one of claims 1 to 5.

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