Communication system, program, and communication method

Abstract

To provide a communication system, a program, and a communication method that can ensure the reliability of wireless communication even when a communication environment changes.SOLUTION: A communication system 100 includes a route information acquisition unit 104 that acquires planned route information, a base station information acquisition unit 105 that acquires base station information including position information of each of a plurality of base stations 72, a threshold acquisition unit 107 that acquires a switching threshold R0 for received radio wave strength when the received radio wave strength of radio waves from the connection destination base station 72 is decreasing, an HO prediction area acquisition unit 108 that acquires an HO prediction area, an arrival time prediction unit 109 that predicts the scheduled arrival time when its own vehicle 81 will arrive at an HO prediction area B, a received radio wave strength prediction unit 110 that predicts the received radio wave strength in the HO prediction area before arriving at the HO prediction area, and a selection unit 111 that selects a communication method to be used in the HO prediction area based on the comparison result between the predicted received radio wave strength and the switching threshold R0.SELECTED DRAWING: Figure 8

Description

[Technical Field]

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

[0002] Conventionally, there are known technologies for wirelessly communicating various data with the outside in order to execute various vehicle functions such as autonomous driving. For example, Patent Document 1 describes a technology for determining whether to continue autonomous driving based on communication status information when communication with an autonomous driving assistance center is interrupted. Furthermore, Patent Document 2 describes a technology for, when there is a data gap, generating assistance data by complementing the data gap with previously received information and outputting the data to a driving assistance device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-71753 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-173904 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology of Patent Document 1 determines the communication status based on whether or not there is a communication interruption, and has the problem that it is not possible to grasp the deterioration of communication quality until a communication interruption occurs. In Patent Document 2, when data loss occurs, the data loss is compensated for and reliability is evaluated using data loss count information, which results in unreliable data transmission and reception and also has the problem that it is not possible to grasp the deterioration of communication quality until data loss occurs. Therefore, there is room for improvement in terms of ensuring communication reliability.

[0005] An object of the present invention is to provide a communication system, a program, and a communication method that can ensure the reliability of wireless communication even when the communication environment changes. [Means for solving the problem]

[0006] (1) A communication system is a communication system equipped with a wireless communication unit mounted on a mobile body and capable of transmitting and receiving data using a plurality of communication methods including a wireless communication method with a base station, wherein route information regarding a route along which the mobile body is scheduled to travel is generated based on input information, and the system includes a route information acquisition unit that acquires the route information, a base station information acquisition unit that acquires base station information including position information of each of a plurality of base stations that cover the communication area of ​​the route included in the acquired route information, a threshold acquisition unit that acquires a switching threshold of received radio wave strength that causes the wireless communication unit to switch to a new wireless communication destination, and a threshold acquisition unit that acquires a switching threshold of received radio wave strength that causes the wireless communication unit to switch to a new wireless communication destination based on at least the position information. the mobile station includes a handover predicted area acquisition unit that acquires a handover predicted area in which a handover is predicted to occur, in which the wireless communication unit switches from a base station currently connected to another base station; an arrival time prediction unit that predicts the arrival time of the mobile unit in the handover predicted area; a received radio wave strength prediction unit that predicts the received radio wave strength of radio waves from the base station in the handover predicted area at the arrival time before arriving at the handover predicted area; and a selection unit that selects a communication method to be used by the wireless communication unit in the handover predicted area based on a comparison result between the received radio wave strength predicted by the received radio wave strength prediction unit and the switching threshold value.

[0007] (2) The communication system described in (1) further includes a communication control unit that, when the predicted received radio wave strength is equal to or less than the switching threshold, multiplexes and transmits the same packet to the new connection destination using multiple different communication methods, and, when the predicted received radio wave strength exceeds the switching threshold, transmits the same data to the currently connected base station using one communication method, and the selection unit selects multiple different communication methods to be used by the wireless communication unit for the multiplexed transmission when the predicted received radio wave strength is equal to or less than the switching threshold.

[0008] (3) In the communication system described in (2), the selection unit predicts the received radio wave strength of radio waves from the wireless communication destination for each of the plurality of communication methods in the handover prediction area at the arrival time, and selects the plurality of different communication methods in order of the predicted received radio wave strength.

[0009] (4) In the communication system described in (2), the selection unit predicts a communication delay time of wireless communication for each of the plurality of communication methods in the handover prediction area at the arrival time, and selects the plurality of different communication methods in order of the predicted communication delay time shortest.

[0010] (5) In the communication system described in (2), the selection unit predicts the amount of data processing required to transmit data when using each of the plurality of communication methods in the handover prediction area at the arrival time, and selects the plurality of different communication methods in order of the predicted least amount of data processing.

[0011] (6) In the communication system described in (2), the selection unit determines the priority of parameters related to communication quality and data processing in the handover prediction area at the arrival time, and selects the plurality of different communication methods based on the parameters with the highest priority.

[0012] (7) In the communication system described in (6), the parameters relating to communication quality and data processing are the received radio wave strength, the communication delay time of wireless communication, and the amount of data processing required for transmitting data.

[0013] (8) The communication system described in any one of (1) to (7) includes an information processing device having the route information acquisition unit, the base station information acquisition unit, the threshold acquisition unit, the handover prediction area acquisition unit, the arrival time prediction unit, the received radio wave intensity prediction unit, and the selection unit, and a communication device having the wireless communication unit that performs bidirectional communication with an external communication device and the information processing device.

[0014] In the communication system described in (9) and (8), the information processing device is capable of communicating with the communication device, an in-vehicle sensor that detects movement information of the mobile body, an outside sensor that detects the surrounding conditions of the mobile body, and an input / output device that accepts input operations by the driver of the mobile body and outputs information to the driver, and generates the route information, predicts the handover prediction area, predicts the arrival time, and predicts the received radio wave strength from the base station in the handover prediction area based on information obtained from the communication device, the in-vehicle sensor, the outside sensor, and the input / output device.

[0015] (10) In the communication system described in (9), the input / output device accepts an input operation by the driver of a plurality of point information used in generating the route information by the information processing device, and transmits the information to the information processing device.

[0016] (11) The program is a program to be executed by a computer of a communication system that is mounted on a mobile body and has a wireless communication unit capable of transmitting and receiving data using multiple communication methods including a wireless communication method with a base station, and that generates route information regarding a route along which the mobile body is scheduled to travel based on input information, and includes a route information acquisition step of acquiring the route information, a base station information acquisition step of acquiring base station information including position information of each of multiple base stations that cover the communication area of ​​the route included in the acquired route information, and a threshold acquisition step of acquiring a threshold for switching the received radio wave intensity that causes the wireless communication unit to switch to a new wireless communication destination based on at least the position information. The computer is caused to execute the following steps: a handover prediction area acquisition step for acquiring a handover prediction area in which a handover is predicted to occur along the route, in which the wireless communication unit switches from a base station currently connected to to another base station; an arrival time prediction step for predicting the arrival time at which the mobile unit will arrive in the handover prediction area; a received radio wave strength prediction step for predicting the received radio wave strength of radio waves from the base station in the handover prediction area at the arrival time before arriving at the handover prediction area; and a selection step for selecting a communication method to be used by the wireless communication unit in the handover prediction area based on the result of comparing the received radio wave strength predicted by the received radio wave strength prediction step with the switching threshold value.

[0017] (12) A communication method is applied to a communication system equipped with a wireless communication unit mounted on a mobile body and capable of transmitting and receiving data using a plurality of communication methods including a wireless communication method with a base station, and includes a route information acquisition step of generating route information regarding a route along which the mobile body is scheduled to travel based on input information, acquiring the route information, a base station information acquisition step of acquiring base station information including position information of each of a plurality of base stations covering the communication area of ​​the route included in the acquired route information, a threshold acquisition step of acquiring a threshold for switching the received radio wave strength when the received radio wave strength from the destination base station has decreased, causing the wireless communication unit to switch the wireless communication to a new destination, and a step of acquiring at least the position information. the route information includes a handover prediction area acquisition step of acquiring a handover prediction area where a handover is predicted to occur, in which the wireless communication unit switches from a base station currently connected to another base station, on the route included in the route information, based on the route information; an arrival time prediction step of predicting an arrival time at which the mobile unit will arrive in the handover prediction area; a received radio wave strength prediction step of predicting a received radio wave strength of radio waves from the base station in the handover prediction area at the arrival time before arriving at the handover prediction area; and a selection step of selecting a communication method to be used by the wireless communication unit in the handover prediction area based on a comparison result between the received radio wave strength predicted in the received radio wave strength prediction step and the switching threshold value. [Effects of the Invention]

[0018] According to the present invention, the reliability of wireless communication can be ensured even when the communication environment changes. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic diagram illustrating a communication system according to an embodiment of the present invention and an external communication device that performs wireless communication with the communication system. [Figure 2] 1 is a schematic diagram illustrating an example of a communication system according to an embodiment of the present invention and a road to which the communication system is applied. [Figure 3]1 is a block diagram showing a hardware configuration of a communication device in a communication system according to an embodiment of the present invention. [Figure 4] 1 is a block diagram showing a hardware configuration of an information processing device in a communication system according to an embodiment of the present invention. [Figure 5] FIG. 1 is a schematic diagram showing the communication state between a communication system and a base station when the communication environment in an HO area is good. [Figure 6] 1 is a schematic diagram showing the communication state between a communication system and a base station when the communication environment in an HO area deteriorates. [Figure 7] 1 is a block diagram showing a configuration of functional blocks of a communication device in a communication system according to an embodiment of the present invention. [Figure 8] 1 is a block diagram showing a functional block configuration of an information processing device in a communication system according to an embodiment of the present invention; [Figure 9] FIG. 1 is a schematic diagram showing multiple communication methods available in an HO area. [Figure 10] FIG. 2 is a sequence diagram showing an example of a flow up to wireless communication control processing in a communication system according to an embodiment of the present invention. [Figure 11] 5 is a flowchart illustrating an example of a wireless communication control process executed by a communication processing device according to an embodiment of the present invention. [Figure 12] 10 is a flowchart showing an example of an HO area prediction process of the wireless communication control process executed by the communication processing device according to one embodiment of the present invention. [Figure 13] 10 is a flowchart showing an example of an HO compatible process of the wireless communication control process executed by the communication processing device according to one embodiment of the present invention. [Figure 14] 14 is a flowchart showing an example of a process, different from that shown in FIG. 13, of the HO compatible process in the wireless communication control process executed by the communication processing device according to one embodiment of the present invention. [Figure 15]15 is a flowchart showing an example of a process different from that shown in FIGS. 13 and 14 of an HO compatible process in the wireless communication control process executed by the communication processing device according to one embodiment of the present invention. [Figure 16] 16 is a flowchart showing an example of a process, different from those shown in FIGS. 13 to 15, of the HO compatible process in the wireless communication control process executed by the communication processing device according to one embodiment of the present invention. [Figure 17] 17 is a flowchart showing an example of a process, different from those shown in FIGS. 13 to 16, of the HO compatible process in the wireless communication control process executed by the communication processing device according to one embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, a communication system 100 will be described as an example of a communication system according to an embodiment of the present invention. Fig. 1 is a schematic diagram showing the communication system 100 and an external communication device 7 that performs wireless communication with the communication system 100. Fig. 2 is a schematic diagram showing an example of the communication system 100 and a road 83 to which the communication system 100 is applied.

[0021] The communication system 100 is a system that is mounted on a moving object 8 and that wirelessly communicates various data with an external communication device 7 in order to execute multiple functions of the moving object 8. Examples of the moving object 8 include a vehicle and a drone. The moving object 8 may be a moving object with a person on board, or may be a moving object without a person on board, such as an unmanned vehicle or an unmanned aerial vehicle. In this embodiment, the communication system 100 mounted on the moving object 8 that is a vehicle will be described as an example. Note that, among the moving objects 8 that are vehicles, the moving object 8 that is mounted with the communication system 100 is referred to as the host vehicle 81, and the moving object 8 that is another vehicle as seen from the host vehicle 81 is referred to as the other vehicle 82.

[0022] The host vehicle 81 is, for example, an autonomously controlled or remotely controlled automatically driving vehicle. The host vehicle 81 is configured to be able to wirelessly communicate with the external communication device 7. The host vehicle 81 may be, for example, a vehicle that performs automatic driving based on estimated position information of the host vehicle 81 and map information about the surroundings of the host vehicle 81. Furthermore, for example, the host vehicle 81 may be a vehicle that performs automatic driving based on a control signal from a remote control center or the like.

[0023] The various functions of the mobile object 8 may be, for example, functions related to autonomous driving, functions related to driving assistance other than autonomous driving, functions related to calls with the outside world, or functions related to entertainment such as videos and games. The functions related to autonomous driving may be, for example, a collision safety function for avoiding a collision with an obstacle or another vehicle 82, a function for autonomously controlling the host vehicle 81, or a function for remotely controlling the host vehicle 81. Data required for the function for autonomously controlling the host vehicle 81 may be, for example, route information along which the host vehicle 81 travels under autonomous control, vehicle surroundings information indicating the conditions around the host vehicle 81, and driving information such as the speed of the host vehicle 81. Data required for the function for remotely controlling the host vehicle 81 may be vehicle surroundings information or a control signal for controlling the driving of the host vehicle 81. In the following description, the functions of the mobile object 8 are referred to as vehicle functions.

[0024] Before describing the communication system 100, an external communication device 7 that performs wireless communication with the communication system 100 will be described.

[0025] Examples of the external communication device 7 include a base station 72, a control server 71, a satellite system 73, a drone 74, a communication device (not shown) of another vehicle 82, a roadside device 75, and a communication terminal (not shown) carried by a pedestrian. The communication system 100 performs V2X (vehicle-to-everything) communication with these devices, which includes various communication methods such as V2N (vehicle-to-network) communication, V2V (vehicle-to-vehicle) communication, V2I (vehicle-to-infrastructure) communication, V2D (vehicle-to-device) communication, and V2P (vehicle-to-pedestrian) communication.

[0026] The base station 72 performs V2N communication by wirelessly communicating with various devices such as communication devices of mobile objects 8 moving on a road 83. The multiple base stations 72 are installed in different communication areas and are communicably connected to the control server 71 and other base stations 72 via a communication network NW. A communication area refers to a geographical range in which each base station 72 is responsible for communication with each mobile object 8. In the example shown in FIG. 2, base stations 72A and 72B, which are multiple base stations 72, are installed at intervals.

[0027] The base station 72 transmits data acquired through wireless communication with mobile objects 8 traveling within the communication area and various devices to the control server 71 via the communication network NW, or directly to the communication device of the mobile object 8.

[0028] Examples of communication networks NW include mobile communication networks operated by various communication carriers, core networks that connect mobile communication networks, and wide area networks (WANs) that include private networks and the Internet.

[0029] In this embodiment, the base station 72 holds, for example, its own identification information and data relating to the communication load (hereinafter referred to as communication load related data). The communication load related data includes, for example, communication traffic within its own communication area, the number of connections of communication partners such as mobile units 8 that are wirelessly communicating with the base station 72, and the like.

[0030] The control server 71 is communicably connected to external communication devices 7 such as a plurality of base stations 72 via a communication network NW, acquires various data from the external communication devices 7, and stores and manages the data in a database or the like.

[0031] The control server 71 also has a function of transmitting various data to the communication system 100 of the mobile object 8 via the base station 72, the communication devices of the other vehicles 82, etc. The information transmitted by the control server 71 includes, for example, map information including the route along which the mobile object 8 will travel, including roads 83, position information of the mobile object 8, control signals for remotely controlling the mobile object 8, and various data required for autonomous control of the mobile object 8, and the like, which are transmitted to the communication system 100. The map information includes position information of the base station 72, buildings, structures, etc. located near the route. The control server 71 also transmits current and past communication environment related information to the communication system 100. Examples of the communication environment related information include data on communication load such as communication traffic within the communication area A of the base station 72, the number of connections of communication partners such as mobile units 8 that are wirelessly communicating with the base station 72, images showing traffic conditions such as the traffic volume of mobile units 8, data such as images showing radio wave shields that exist around the base station 72 and block radio waves, and meteorological information including information on weather such as sunny, cloudy, rainy, etc., and amount of rain. Examples of radio wave shields include mobile units 8 such as buildings and vehicles.

[0032] The satellite system 73 may be, for example, a navigation satellite, a low-earth orbit satellite, or a geostationary orbit satellite that constitutes a global navigation satellite system (GNSS) such as a global positioning system (GPS) or a quasi-zenith satellite system. The satellite system 73, which is a navigation satellite, transmits GNSS signals indicating position information, satellite images that can grasp traffic information such as images including a road 83 on which the vehicle 81 is traveling, and the like to the ground. By analyzing the satellite images, it is possible to identify the position information of radio wave blocking objects such as buildings and mobile objects 8 that block radio waves. The satellite system 73, which is a low-earth orbit satellite, constitutes a non-terrestrial network (NTN) and enables wireless communication according to the 5G communication standard or the like.

[0033] The drone 74 transmits, for example, images including a road 83 on which the moving object 8 is traveling to the control server 71, the base station 72, the communication system 100, etc. The drone 74 constitutes a non-terrestrial network. For example, the satellite system 73 and the drone 74 may transfer data acquired from the control server 71, the base station 72, the communication device of the other vehicle 82, etc. to the communication system 100.

[0034] The communication device of the other vehicle 82 communicates with the communication devices of other moving bodies 8, including the vehicle itself 81, using V2V communication or V2N communication via a base station 72, and may transmit data indicating the wireless communication status, such as the amount of communication with the outside world, as well as its own location information, identification information, etc.

[0035] The roadside units 75 are also called RSUs (road side units) or the like. The roadside units 75 are installed in different communication areas around (on the roadside of) a road 83. A communication area refers to the range in which each roadside unit is responsible for communication with each mobile object 8, and indicates, for example, a geographical range set along the road 83.

[0036] The roadside unit 75 provides a V2X communication service by wirelessly communicating with communication devices of mobile objects 8 traveling on the road 83 and various devices present in the vicinity. The roadside unit 75 also transmits data acquired through wireless communication with mobile objects 8 traveling within the communication area and various devices to the control server 71 via the communication network NW, or directly to the communication devices of the mobile objects 8.

[0037] A communication terminal carried by a pedestrian or the like (hereinafter referred to as a pedestrian communication terminal) performs wireless communication with other external communication devices 7 including a base station 72. The pedestrian communication terminal may perform V2P communication with a communication device of a mobile object 8 including the vehicle 81, or may relay wireless communication between the communication device of the mobile object 8 and the base station 72.

[0038] 1, the communication system 100 is mounted on a mobile object 8 and includes a communication processing device 6, an in-vehicle sensor 4, and an outside-vehicle sensor 5. The communication system 100 predicts in advance the handover control of the base station 72 in response to a poor communication environment, and performs processing to select a communication method that can cope with the deterioration of communication quality due to the handover.

[0039] The in-vehicle sensor 4 is a sensor for detecting driving information such as the speed, acceleration, and angular velocity of the host vehicle 81. Examples of the in-vehicle sensor 4 include a vehicle speed sensor that detects the speed of the host vehicle 81, an acceleration sensor that detects the acceleration of the host vehicle 81, and a yaw rate sensor that detects the yaw angular velocity of the host vehicle 81.

[0040] The exterior sensor 5 is a device for detecting information about the surroundings of the host vehicle 81. The exterior sensor 5 may be, for example, a radar such as a millimeter-wave radar, a LiDAR (light detection and ranging), or a camera. The camera detects information about the surroundings of the host vehicle 81 by capturing still or video images of the surroundings of the host vehicle 81. The millimeter-wave radar or LiDAR detects the distance, direction, relative speed, etc. of objects present around the host vehicle 81 based on transmission waves transmitted to the surroundings of the host vehicle 81 and reflected received waves. The exterior sensor 5 of this embodiment irradiates the surroundings with millimeter waves or laser light and detects surrounding objects as point cloud data, thereby detecting the positions, shapes, etc. of surrounding objects with high accuracy. The exterior sensor 5 transmits the detected point cloud data to the information processing device 1. Position information of radio wave blocking objects such as buildings and other vehicles 82 present around the host vehicle 81 can be obtained from the point cloud data detected by the exterior sensor 5.

[0041] The communication processing device 6 includes an input / output device (HMI; Human Machine Interface) 3, a communication device 2, and an information processing device 1. In this embodiment, the HMI 3, the communication device 2, and the information processing device 1 are separate entities, but they may also be integrated. By separating the communication device 2 from the information processing device 1, etc., the processing in the device can be specialized for wireless communication with the external communication device 7, allowing for smoother wireless communication.

[0042] The HMI 3 is an interface that receives information input by the driver of the vehicle 81 and outputs the information to the driver. The HMI 3 may be configured to include, for example, buttons, a display, a speaker, etc. The information that the driver inputs to the HMI 3 may be, for example, point information for generating route information along which the vehicle 81 is scheduled to travel. The point information may be the current location of the vehicle 81, the starting point of the planned route, the destination point, stop-off points along the route from the starting point to the destination point, and evacuation points. An evacuation point is, for example, an area where the vehicle 81, while autonomously driving, makes an emergency stop in the event of an abnormality, etc. Note that there may be multiple stop-off points and evacuation points.

[0043] The communication device 2 is a part that performs wireless communication with the external communication device 7. The communication device 2 may be a device that handles either or both of telematics and infotainment information. The communication device 2 of this embodiment transmits and receives data to and from the external communication device 7 via multiple wireless lines using various communication methods. The data acquired by the communication device 2 is transmitted to the information processing device 1.

[0044] Here, the hardware configuration of the communication device 2 will be described with reference to Fig. 3. Fig. 3 is a block diagram showing the hardware configuration of the communication device 2.

[0045] The communication device 2 includes a computer 28, a storage unit 23, a wireless communication unit 24, and an I / F unit 25. A bus 27 and the like connect these units together.

[0046] The computer 28 includes a processor 20 and a read-only memory (ROM) 21 and a random-access memory (RAM) 22 as main storage devices. The processor 20 may be a central processing unit (CPU), a microprocessing unit (MPU), a system on a chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a field-programmable gate array (FPGA). Alternatively, the processor 20 may be a combination of these. The processor 20 may also be a combination of these with a hardware accelerator or the like. The processor 20 controls each component to realize various functions of the communication device 2 based on programs such as firmware, system software, and application software stored in the ROM 21, the RAM 22, or an auxiliary storage device that is part of the storage unit 23. Note that some or all of the programs may be incorporated into the circuitry of the processor 20.

[0047] The storage unit 23 is a storage area for various programs and various data for causing the hardware group to function as the communication device 2, and can be configured with a ROM, RAM, flash memory, a solid-state drive (SSD), a hard disk drive (HDD), etc. Specifically, the storage unit 23 stores programs and the like for causing the computer 28 to execute each function of this embodiment.

[0048] The wireless communication unit 24 executes processing for the communication device 2 to perform wireless communication with the external communication device 7. The wireless communication unit 24 is configured to be able to transmit data using multiple communication methods, such as V2N communication using a base station 72 as the wireless communication destination, V2I communication using a roadside device 75 as the wireless communication destination, V2V communication using a communication device of another vehicle 82 as the wireless communication destination, V2D communication using a drone 74 as the wireless communication destination, V2P communication using a communication device carried by a pedestrian as the wireless communication destination, NTN communication using a satellite system 73 as the wireless communication destination, and MEC (Multi-access Edge Computing) communication. The wireless communication unit 24 can also transmit data using multiple wireless links. The type of wireless link is not particularly limited. Examples of wireless links include wireless LAN (Local Area Network) communication standards including Wi-Fi (registered trademark), LTE (Long Term Evolution) communication standards, and wireless communication links within the same communication carrier based on 5G communication standards, and wireless communication links between different communication carriers. Wireless communication links based on communication standards such as 6G communication standards, which are being put into practical use, can also be used.

[0049] The I / F unit 25 is a communication interface for the communication device 2 to communicate with the information processing device 1. The I / F unit 25 may be a wired communication interface compatible with an in-vehicle communication means such as a wire harness for electrical communication or an optical fiber cable for high-speed optical communication, or at least a part of the I / F unit 25 may be a wireless communication interface.

[0050] The GNSS unit 26 includes an antenna and receives GNSS signals, etc. The GNSS unit 26 transmits the received GNSS signals to the processor 20. The GNSS unit 26 may transmit the received GNSS signals to the information processing device 1 via the I / F unit 25.

[0051] The following describes the information processing device 1. The information processing device 1 acquires and processes various information from an in-vehicle sensor 4, an out-vehicle sensor 5, a communication device 2, and an HMI 3. The information processing device 1 controls the communication device 2 and functions of the vehicle 81 related to autonomous driving and the like through wireless communication with an external communication device 7.

[0052] Next, an example of the hardware configuration of the information processing device 1 will be described with reference to Fig. 4. Fig. 4 is a block diagram showing the hardware configuration of the information processing device 1.

[0053] The information processing device 1 includes a computer 16, a storage unit 13, and an I / F unit 14. A bus 15 and the like connect these units together.

[0054] The computer 16 includes a processor 10 and a read-only memory (ROM) 11 and a random-access memory (RAM) 12 as main storage devices. The processor 10 may be a central processing unit (CPU), a microprocessing unit (MPU), a system on a chip (SoC), a digital signal processor (DSP), a graphics processing unit (GPU), an application-specific integrated circuit (ASIC), a programmable logic device (PLD), or a field-programmable gate array (FPGA). Alternatively, the processor 10 may be a combination of these. The processor 10 may also be a combination of these with a hardware accelerator or the like. The processor 10 controls each unit to realize various functions of the information processing device 1 based on programs such as firmware, system software, and application software stored in the ROM 11, the RAM 12, or an auxiliary storage device that is part of the storage unit 13. Note that some or all of the programs may be incorporated into the circuitry of the processor 10.

[0055] The storage unit 13 is a storage area for storing various programs and various data for causing the hardware group to function as the information processing device 1, and can be configured with a ROM, RAM, flash memory, a solid-state drive (SSD), a hard disk drive (HDD), or the like. Specifically, the storage unit 13 stores programs for causing the computer 16 to execute each function of this embodiment, and information related to vehicle functions (hereinafter referred to as vehicle function-related information). Examples of the vehicle function-related information include details of vehicle functions such as collision safety functions, details of data transmitted and received via wireless communication, parameters related to communication quality and data processing, and their priorities, which will be described later.

[0056] The I / F unit 14 is a wired communication interface through which the information processing device 1 communicates with the communication device 2, the in-vehicle sensor 4, the outside sensor 5, or the ECU 84 of the host vehicle 81. The information processing device 1 uses the I / F unit 14 to communicate with the in-vehicle sensor 4, the outside sensor 5, the ECU 84, etc. via an in-vehicle LAN including, for example, Ethernet (registered trademark), which is implemented by CAN (Controller Area Network) communication, LIN (Local Interconnect Network) communication, electrical communication, or optical communication. Note that the I / F unit 14 may be a wired communication interface compatible with in-vehicle communication means, such as a wire harness for electrical communication or an optical fiber cable for high-speed optical communication, or at least a part of the I / F unit 14 may be a wireless communication interface.

[0057] 2, for example, when the vehicle 81 continues traveling within a communication area A covered by a base station 72A and the strength of the radio wave received by the communication device 2 from the base station 72A drops below a switching threshold R0, a handover must be performed to continue wireless communication, and the communication destination must be switched from the base station 72A to, for example, a base station 72B. The handover is performed, for example, in a handover area (hereinafter referred to as an HO area) B, which is an area where the communication areas A of the base stations 72 overlap. The switching threshold R0 is a reference value of the strength of the radio wave received that causes the communication device 2 to perform a handover.

[0058] For example, if handover by a mobile unit 8, which is an autonomous vehicle, does not proceed smoothly due to a deterioration in the communication environment, etc., data loss or delays in data transmission speed may occur, making it impossible to perform important functions such as autonomous driving, and there is a risk that the reliability of the mobile unit 8's functions via wireless communication cannot be guaranteed.

[0059] The traffic conditions, such as the traffic volume of the mobile object 8, on the road 83 on which the mobile object 8 travels change depending on the location, time of day, and events such as the occurrence of an accident. In addition, the environment around the road 83 also changes as the mobile object 8 moves, such as a rural area with few radio wave shields or an urban area with many radio wave shields. Therefore, the communication environment around the communication device 2 mounted on the mobile object 8 also tends to change depending on the traffic conditions, etc.

[0060] Fig. 5 is a schematic diagram showing a situation where the communication environment in HO area B is good. Fig. 6 is a schematic diagram showing a situation of road 83 where the communication environment in HO area B is deteriorated.

[0061] In the example shown in Fig. 5, there is little traffic of mobile objects 8 around the base station 72A where the vehicle 81 is traveling, and there is little communication traffic from the mobile objects 8 and other external communication devices 7. There are also few radio wave obstructions between the base station 72 and the vehicle 81. In this situation, as shown in Fig. 5, the vehicle 81 can continue traveling without performing a handover. This allows the communication device of the mobile object 8 to communicate wirelessly with the base station 72 without interruption.

[0062] On the other hand, in the example shown in FIG. 6 , there is heavy traffic in HO area B, and many radio wave obstructions, such as other vehicles 82, exist between the host vehicle 81 and HO area B or base station 72. In such a situation, as shown in FIG. 6 , the communication environment in HO area B deteriorates, and the received radio wave strength from base station 72B in HO area B decreases. In this case, a handover is performed early to switch the connection from base station 72A to base station 72B or the like. The handover may cause interruptions or delays in communication between the communication device 2 and the control server 71 or the like via the base station 72. For this reason, for example, when a mobile object 8, which is an autonomous vehicle, moves through HO area B, data loss or delays in data transmission speed may occur in wireless communication with base station 72, which may prevent the mobile object 8 from performing important functions, such as autonomous driving, and may make it difficult to ensure the reliability of the mobile object 8's functions via wireless communication.

[0063] The communication system 100 according to this embodiment performs wireless communication control processing to perform multiplexed data transmission by predicting the HO area B. This wireless communication control processing can ensure the reliability of communication in the HO area B.

[0064] Next, various functions that are realized by the processor 20 of the communication device 2 and that execute wireless communication control processing will be described with reference to FIG.

[0065] As shown in FIG. 7, the processor 20 of the communication device 2 includes a self-position estimation unit 201, a communication mode switching unit 202, and a communication control unit 203.

[0066] The self-position estimation unit 201 executes a process of estimating position information (hereinafter referred to as self-position information) of the vehicle 81. The self-position estimation unit 201 may estimate the self-position information based on, for example, map information, a GNSS signal, or the like received from the control server 71.

[0067] The communication mode switching unit 202 executes a process of switching the wireless communication mode between a normal mode and an HO-compatible mode based on a control signal from the information processing device 1. The normal mode is a mode in which data required to execute each of a plurality of functions of the host vehicle 81 is transmitted using one predetermined communication method. In the normal mode of this embodiment, the communication device 2 uses a V2N communication method to communicate with the base station 72. The base station 72 then transmits and receives data to and from the control server 71 via the communication network NW. That is, the communication device 2 transmits and receives data to and from the control server 71 via the base station 72. The HO-compatible mode is a communication mode compatible with wireless communication in an HO area B in a degraded communication environment, and transmits data required to execute the functions of the host vehicle 81 using a communication method in accordance with transmission control information (described later) from the information processing device 1.

[0068] The communication control unit 203 executes processing to control wireless communication between the communication device 2 and the external communication device 7 and communication between the communication device 2 and the information processing device 1. The communication control unit 203 controls wireless communication with the external communication device 7 in accordance with the communication mode switched by the communication mode switching unit 202.

[0069] Next, various functions realized by the processor 10 of the information processing device 1 will be described with reference to FIG.

[0070] As shown in FIG. 8, the processor 10 of the information processing device 1 includes a location information acquisition unit 101, a map information acquisition unit 102, a position information acquisition unit 103, a route information acquisition unit 104, a base station information acquisition unit 105, a communication environment related information acquisition unit 106, a threshold acquisition unit 107, an HO prediction area acquisition unit 108, an arrival time prediction unit 109, a received radio wave intensity prediction unit 110, a selection unit 111, and a communication control unit 112.

[0071] The point information acquisition unit 101 executes a process of acquiring point information. For example, the point information acquisition unit 101 executes a process of acquiring point information input by the driver from the HMI 3. The point information acquired from the HMI 3 may be position information such as a departure point of a planned route of the vehicle 81, a destination point, a stop-off point on the route from the departure point to the destination point, an evacuation point, etc. The point information acquisition unit 101 may also acquire self-position information of the current location acquired by the position information acquisition unit 103 as point information.

[0072] The map information acquisition unit 102 executes a process of acquiring map information including at least the road 83 on which the vehicle 81 is traveling and the road 83 on which the vehicle 81 is scheduled to travel. The map information acquisition unit 102 acquires the map information from the control server 71 via the communication device 2, for example.

[0073] The position information acquisition unit 103 executes a process of acquiring self-position information of the current location (hereinafter referred to as current location information). The position information acquisition unit 103 may acquire, for example, current location information of the vehicle 81 estimated by the self-position estimation unit 201 of the communication device 2. Alternatively, for example, the position information acquisition unit 103 may estimate current location information of the vehicle 81 based on map information, a GNSS signal, etc. acquired by the map information acquisition unit 102, and acquire the estimated information as the current location information. Alternatively, for example, the position information acquisition unit 103 may acquire vehicle surroundings information such as point cloud information around the vehicle 81 from the external vehicle sensor 5, acquire map information from the control server 71 via the communication device 2, and compare the vehicle surroundings information with the map information to estimate the position information of the vehicle 81, thereby acquiring the self-position information.

[0074] The route information acquisition unit 104 executes a process of acquiring planned route information regarding a route along which the vehicle 81 is scheduled to travel. The route information acquisition unit 104 may generate route information based on the point information acquired by the point information acquisition unit 101, the map information acquired by the map information acquisition unit 102, the current location information acquired by the position information acquisition unit 103, and the like, and acquire the generated information as planned route information. As a method of generating the planned route information, for example, a starting point or the current location, a destination point, a stop-off point, and an evacuation point may be identified on a map indicated by the map information, and roads 83 connecting these may be generated as planned route information. Furthermore, for example, the route information acquisition unit 104 may acquire route information as planned route information from a car navigation device or the like that generates route information, or may acquire route information stored in the control server 71 from the control server 71 as planned route information.

[0075] The base station information acquisition unit 105 executes a process of acquiring base station information including the location information and identification information of each of a plurality of base stations 72 existing along the route included in the planned route information and in the vicinity thereof. In this embodiment, the base station information acquisition unit 105 may acquire roadside unit information including the location information and identification information of each of a plurality of roadside units 75 existing along the route included in the planned route information in addition to the base stations 72.

[0076] The communication environment related information acquisition unit 106 executes a process of acquiring, via the communication device 2, communication environment related information about the road 83 and its surroundings, which is included in the planned route information acquired by the route information acquisition unit 104. The communication environment related information acquisition unit 106 may acquire, for example, data related to communication loads, such as communication traffic in a communication area A covered by base stations 72 installed at each point on the road 83 included in the planned route information managed by the control server 71, and the number of connections to the base station 72 from communication devices of mobile objects 8 and communication terminals of pedestrians and the like that wirelessly communicate with the base station 72 (hereinafter, communication load related data). Furthermore, for example, the communication environment related information acquisition unit 106 may acquire communication load related data, such as current communication traffic in the communication area A of the base station 72, or communication load related data, such as communication traffic in the same time period in the past. For example, the communication environment related information acquisition unit 106 may acquire position information and wireless communication volume of each mobile body 8 from a communication device of another vehicle 82 traveling on a road 83 included in the planned route information by V2V communication with the other vehicle 82 or V2N2V communication via the base station 72 or the communication network NW. For example, the communication environment related information acquisition unit 106 may acquire an image including the road 83 indicated in the planned route information from the satellite system 73 or the drone 74, and extract information about traffic conditions such as traffic volume of the mobile body 8, position information of the mobile body 8 and radio wave shielding objects such as buildings, from the acquired image. For example, weather information may be acquired from the satellite system 73, which is a meteorological satellite. For example, the communication environment related information acquisition unit 106 may acquire communication volume between the pedestrian communication terminal of a pedestrian walking on the road 83 included in the planned route information and the base station 72, etc., from the base station 72, the pedestrian communication terminal, etc.

[0077] In this embodiment, the communication environment related information acquisition unit 106 may acquire data related to communication load such as communication traffic and number of connections in the communication area of ​​the roadside unit 75, satellite system 73, drone 74, communication devices of other vehicles 82, etc., and location information of radio wave obstructions predicted to exist between the communication device 2 in the HO prediction area, in a similar manner to the communication load related data of the base station 72.

[0078] The threshold acquisition unit 107 executes a process of acquiring a switching threshold R0 for received radio wave strength set in each base station 72. In the communication system 100 according to this embodiment, when the received radio wave strength received from the currently connected base station 72 falls below the switching threshold R0, the base station 72 searches for a new wireless connection destination for the communication device 2, and switches the connection to the new connection destination.

[0079] The HO predicted area acquisition unit 108 executes a process to acquire a predicted area of ​​HO area B where handover will be performed (hereinafter referred to as HO predicted area). The HO predicted area acquisition unit 108 may acquire, for example, predetermined location information of HO area B stored in the control server 71 or each base station 72 as the HO predicted area. The HO predicted area acquisition unit 108 may also acquire the HO predicted area by predicting HO area B based on various information. In this case, the HO predicted area acquisition unit 108 may predict HO area B based on base station information, or may predict HO area B based on the base station information and the switching threshold R0 of each base station 72 indicated by the base station information, or may further take communication environment-related information into account when predicting HO area B.

[0080] When the HO area B is acquired by the HO prediction area acquisition unit 108, the arrival time prediction unit 109 predicts the scheduled arrival time, which is the time when the host vehicle 81 will arrive in the HO area B. The arrival time prediction unit 109 may, for example, acquire driving information such as the vehicle speed of the host vehicle 81 from the in-vehicle sensor 4 and predict the scheduled arrival time based on the driving information. The arrival time prediction unit 109 may predict the scheduled arrival time using at least one of the legal speed limit of the road 83 indicated by the scheduled route information, the average speed of the traveling mobile object 8, traffic conditions, and the vehicle speed of the host vehicle 81.

[0081] The received signal strength prediction unit 110 executes a process of predicting the received signal strength from the base station 72 in the HO prediction area at the scheduled arrival time predicted by the arrival time prediction unit 109 before the vehicle arrives at the HO prediction area. In the following description, the predicted value of the received signal strength from the base station 72 in the HO prediction area at the scheduled arrival time is referred to as predicted value R1. In this embodiment, predicted value R1 is a predicted value for the radio waves transmitted from the currently connected base station 72.

[0082] The received signal strength prediction unit 110 may use, for example, the received signal strength from the currently connected base station 72 in the HO prediction area in the past during the same time period as the expected arrival time as the predicted value R1. Alternatively, for example, the received signal strength prediction unit 110 may predict the predicted value R1 based on at least one of the following information: the total wireless communication volume of communication devices, such as other vehicles 82, currently traveling in the HO prediction area; data related to the current communication load of the currently connected base station 72 in the HO prediction area; and information on radio wave obstructions located between the currently connected base station 72 and the vehicle 81, as identified by the location information of the radio wave obstructions, the currently connected base station 72, and the HO prediction area. Alternatively, for example, the received signal strength prediction unit 110 may predict the predicted value R1 based on both past communication environment-related information in the HO prediction area and current communication environment-related information obtained in real time. Alternatively, for example, the received signal strength prediction unit 110 may further predict the predicted value R1 based on weather information for the HO prediction area at the expected arrival time. For example, when the frequency of the radio wave used for wireless communication between the communication device 2 and the connected base station 72 is equal to or higher than a predetermined frequency (e.g., 10 GHz), the received radio wave intensity prediction unit 110 may predict that the greater the predicted rainfall in the HO prediction area at the predicted arrival time, the lower the predicted value R1. This makes it possible to more accurately predict the predicted value R1 for handover of wireless communication using high-frequency radio waves, since the higher the frequency of the radio wave used for wireless communication, the greater the tendency for it to be affected by rain, etc.

[0083] The selection unit 111 executes a process of selecting a communication method to be used by the wireless communication unit 24 at least in the HO prediction area based on the comparison result between the predicted value R1 predicted by the received signal strength prediction unit 110 and the switching threshold R0. In this embodiment, when the predicted value R1 is equal to or smaller than the switching threshold R0, the selection unit 111 selects multiple different communication methods to be used by the wireless communication unit 24 at least in the HO prediction area. Note that when the predicted value R1 exceeds the switching threshold R0, the selection unit 111 decides to communicate with the currently connected base station 72 without selecting multiple different communication methods.

[0084] The selection unit 111 may select a communication method by performing, for example, the following processes (A) to (D). (A) Identify the communication methods available in the HO prediction area (B) Determine the priority of selection parameters that are the criteria for selecting a communication method. (C) Predict the values ​​of the selection parameters for each communication method (D) Select multiple communication methods from the multiple communication methods identified in (A).

[0085] The processes (A) to (D) will be described with reference to Fig. 9. Fig. 9 is a schematic diagram showing an example of a plurality of communication methods that can be used by the communication device 2 mounted on the vehicle 81 in the HO prediction area. The two-dot chain circle shown in Fig. 9 indicates the HO prediction area.

[0086] In the process of (A), the selection unit 111 identifies a connection destination other than the currently connected base station 72 with which communication is possible using the wireless communication unit 24 in the HO prediction area in order to select a plurality of different communication methods. That is, the selection unit 111 identifies a route destination that can be used to communicate with the control server 71 in the HO prediction area. In FIG. 9 , five communication methods are available in the HO prediction area: V2N communication with base station 72A, which is the currently connected base station 72, or a base station 72B different from the currently connected base station 72; V2I communication with a roadside device 75; V2V communication with a communication device mounted on another vehicle 82; communication with base station 72A via a satellite system 73, i.e., communication using NTN; and V2D communication with a drone 74.

[0087] In the process (B), the selection unit 111 determines the priority of selection parameters related to communication quality and data processing in the HO prediction area. Examples of the selection parameters include received radio wave strength, communication delay time of wireless communication, and the amount of data processing required for data transmission by the communication processing device 6. The selection unit 111 may set the priority of the selection parameters to the priority selected by the driver of the vehicle 81. That is, the selection unit 111 may determine the priority input by the driver of the vehicle 81 and accepted by the HMI 3 as the priority of the selection parameters. Furthermore, for example, the priority of the selection parameters may be information that is predetermined and stored in the storage unit 13 or the like.

[0088] In the process (C), the selection unit 111 predicts the value of a selection parameter for each communication method. For example, the selection unit 111 predicts the received radio wave strength of radio waves from wireless communication connection destinations (in FIG. 9 , the roadside unit 75, the communication device mounted on the other vehicle 82, the satellite system 73, the base station 72B, and the drone 74) for each of the plurality of communication methods in the HO prediction area at the scheduled arrival time. In the following description, the predicted value of the received radio wave strength of radio waves from the roadside unit 75 is referred to as predicted value R2, the predicted value of the received radio wave strength of radio waves from the communication device of the other vehicle 82 is referred to as predicted value R3, the predicted value of the received radio wave strength of radio waves from the satellite system 73 is referred to as predicted value R4, the predicted value of the received radio wave strength of radio waves from the base station 72B is referred to as predicted value R5, and the predicted value of the received radio wave strength of radio waves from the drone 74 is referred to as predicted value R6. The predicted values ​​R1 to R6 may be predicted, for example, like the predicted value R1, from the received radio wave strength in the past HO prediction area during the same time period as the scheduled arrival time, or may be predicted based on data regarding communication load such as current communication traffic and number of connections, location information of radio wave obstructions, etc.

[0089] Furthermore, for example, the selection unit 111 predicts the communication delay time for each of the communication methods when multiple communication methods are used in the HO prediction area at the scheduled arrival time. The selection unit 111 may predict the communication delay time based on, for example, the communication time, communication traffic, number of connections, etc., of past data transmissions in the HO prediction area during the same time period as the scheduled arrival time, or may predict the communication delay time based on communication traffic in the current HO prediction area.

[0090] Furthermore, for example, the selection unit 111 predicts the amount of data processing required for transmitting data when each of a plurality of communication methods is used in the HO prediction area at the scheduled arrival time. For example, when transmitting data using each communication method, the selection unit 111 may predict the amount of data processing based on whether data read from the storage unit 13 is transmitted or detected data is analyzed and processed before transmission, the number of steps required for data transmission, etc.

[0091] In the process (D), the selection unit 111 selects a plurality of communication methods from the plurality of communication methods identified in the process (A) based on the priority of the selection parameters determined in the process (B) and the predicted value predicted in the process (C) for each communication method of the selection parameters with the highest priority. For example, the selection unit 111 may select a plurality of communication methods based only on the predicted value of the selection parameter with the highest priority, or may select a plurality of communication methods based on the predicted values ​​of a plurality of selection parameters selected in descending order of priority.

[0092] The selection unit 111 may select a communication method without performing the process (B). That is, one selection parameter used for selecting a communication method may be determined in advance, and multiple communication methods may be selected based on the predicted value of the one selection parameter.

[0093] When the predicted value R1 predicted by the received signal strength prediction unit 110 is equal to or less than the switching threshold R0, the communication control unit 112 controls the wireless communication unit 24 in at least the HO prediction area to transmit data using the communication method selected by the selection unit 111. When two or more communication methods are selected by the selection unit 111, the communication control unit 112 multiplexes and transmits data using multiple different communication methods. In this specification, multiplexed transmission refers to transmitting the same packet at the same time using different means. When multiplexing data, the communication control unit 112 duplicates the packet as many times as the number of communication methods used in the multiplexed transmission and transmits the duplicated identical packet using different communication methods. This allows the communication device 2 to multiplex and transmit data even when the communication environment in the HO area B is degraded. Therefore, even if the communication environment in the HO area B is degraded, the base station 72 can process the data by adopting the packet that arrived first, thereby maintaining the reliability of wireless communication. The multiplexed data may be a single message containing multiple packets, or a single message packetized by the communication control unit 112 into multiple packets.

[0094] The communication control unit 112 may perform a process of transmitting data using the communication method selected by the selection unit 111 when the vehicle 81 is within a predetermined distance from the HO prediction area (hereinafter referred to as the HO prediction area or its vicinity). The predetermined distance may be set, for example, depending on the communication area A of the base station 72, the vehicle speed of the vehicle 81, vehicle functions subject to function restrictions, etc. The predetermined distance may be set, for example, to 30 m if the vehicle speed of the vehicle 81 is within the legal speed limit, or 120 m if the vehicle speed is higher. On the other hand, when the predicted value R1 predicted by the received radio wave intensity prediction unit 110 exceeds the switching threshold R0, the communication control unit 112 transmits the same data to the currently connected base station 72 using one communication method.

[0095] Next, an example of the processing flow by the communication processing device 6 in the communication system 100 from generating planned route information for the vehicle 81 until traveling through the HO predicted area will be described with reference to Fig. 10. Fig. 10 is a sequence diagram showing an example of the processing flow from input of point information by the driver until traveling through the HO predicted area.

[0096] As shown in FIG. 10, in step S101, the HMI 3 receives location information such as a departure point and a destination input by the driver of the vehicle 81, for example.

[0097] In step S102, the HMI 3 transmits the location information received in step S101 to the information processing device 1.

[0098] In step S103 , the communication device 2 transmits the map information received from the control server 71 to the information processing device 1 .

[0099] In step S104, the information processing device 1 generates planned route information based on the vehicle surroundings information of the vehicle 81 transmitted from the external sensor 5, the location information transmitted from the HMI 3 in step S102, and the map information transmitted from the communication device 2 in step S103.

[0100] In step S105, the communication device 2 transmits the base station information acquired from the control server 71 to the information processing device 1. The base station information transmitted from the communication device 2 in step S105 includes identification information and location information of the road 83 included in the planned route information and each of the multiple base stations 72 arranged in the vicinity thereof.

[0101] In step S106, the communication device 2 transmits the switching threshold value R0 of each base station 72 acquired from the control server 71 or the base station 72 to the information processing device 1.

[0102] In step S107, the information processing device 1 predicts an HO area B based on the base station information received in step S105, and transmits the predicted HO predicted area to the communication device 2.

[0103] In step S108, the information processing device 1 predicts the scheduled arrival time at which the vehicle 81 will arrive at the HO prediction area based on driving information of the vehicle 81 transmitted from the in-vehicle sensor 4, and transmits the predicted scheduled arrival time to the communication device 2.

[0104] In step S109, the information processing device 1 predicts the received radio wave intensity of the radio waves from the base station 72 in the HO prediction area just before the HO prediction area at the scheduled arrival time predicted in step S108, and obtains a predicted value R1.

[0105] In step S110, the information processing device 1 compares the switching threshold R0 transmitted from the communication device 2 in step S106 with the predicted value R1 predicted in step S109, and determines the data transmission method in the HO prediction area based on the comparison result. Specifically, the information processing device 1 determines whether to perform a process to select a communication method or to transmit over a single line without changing the communication method. When performing the process to select a communication method, the information processing device 1 identifies multiple communication methods available in the HO prediction area and selects two or more communication methods from the identified communication methods.

[0106] In step S111, the information processing device 1 transmits to the communication device 2 transmission control information indicating the data transmission method determined in step S111.

[0107] In step S112, the communication device 2 transmits, for example, data required for executing a vehicle function to a connection destination specified for each communication method via multiplex transmission or one line in accordance with the transmission control information transmitted in step S113.

[0108] In step S113, the communication device 2 transmits to the information processing device 1 the data required to execute each function of the vehicle 81 received from the connection destination.

[0109] In step S114, the information processing device 1 transmits to the HMI 3 the data transmitted from the communication device 2 in step S113.

[0110] In step S115, the HMI 3 outputs the data transmitted from the information processing device 1 in step S114 to a display or the like.

[0111] Next, an example of wireless communication control processing executed by the communication processing device 6 will be described with reference to FIGS.

[0112] First, the overall flow of the wireless communication control process will be described with reference to Fig. 11. Fig. 11 is a flowchart showing an example of the wireless communication control process executed by the communication processing device 6.

[0113] As shown in FIG. 11, in step S10, the processor 10 of the information processing device 1 executes the HO prediction process.

[0114] In step S21, the processor 10 or 20 of the communication processing device 6 determines whether the host vehicle 81 has approached the HO prediction area acquired by the HO prediction process to a predetermined distance. If the processor 10 or 20 determines that the host vehicle 81 has approached to the predetermined distance (step S21; YES), the processor 10 or 20 proceeds to step S30. On the other hand, if the processor 10 or 20 determines that the host vehicle 81 has not approached to the predetermined distance (step S21; NO), the processor 10 or 20 repeats the process of step S21 after a predetermined time has elapsed.

[0115] In step S30, the processor 10 and the processor 20 execute the HO handling process.

[0116] In step S22, the processor 10 or 20 of the communication processing device 6 determines whether the host vehicle 81 has arrived at the HO prediction area and is now a predetermined distance away from the HO prediction area. If the processor 10 or 20 determines that the host vehicle 81 has moved the predetermined distance away (step S22; YES), the processor 10 or 20 switches the communication mode of the communication device 2 from the HO-compatible mode to the normal mode (step S50), and then ends the wireless communication control process. On the other hand, if the processor 10 or 20 determines that the host vehicle 81 has not moved the predetermined distance away (step S22; NO), the processor 10 or 20 repeats the process of step S22 after a predetermined time has elapsed.

[0117] Next, the HO prediction process in step S10 of the wireless communication control process will be described with reference to Fig. 12. Fig. 12 is a flowchart showing an example of the HO prediction process executed by the communications processing device 6.

[0118] As shown in FIG. 12, in step S11, the location information acquisition unit 101 of the processor 10 acquires location information such as the departure point and destination point of the vehicle 81 input by the driver of the vehicle 81 via the HMI 3 from the HMI 3.

[0119] In step S12, the map information acquisition unit 102 acquires map information transmitted from the control server 71 via the communication device 2, and the position information acquisition unit 103 acquires current position information of the vehicle 81 as its own position information.

[0120] In step S13, the route information acquisition unit 104 generates planned route information based on the location information, self-position information, and map information acquired in steps S11 and S12.

[0121] In step S14, the base station information acquisition unit 105 acquires base station information of the base stations 72 that exist on the route included in the planned route information generated in step S13 and in the vicinity thereof.

[0122] In step S15, the threshold acquisition unit 107 acquires a switching threshold R0 for the received radio wave strength of at least the currently connected base station 72, and stores the acquired threshold in the storage unit 13. The threshold acquisition unit 107 may acquire the switching threshold R0 of not only the currently connected base station 72, but also the base station 72 indicated by the base station information acquired in step S13.

[0123] In step S16, the HO predicted area acquisition unit 108 predicts the HO area B based on the base station information and the like acquired in step S14, and acquires the HO predicted area.

[0124] In step S17, the arrival time prediction unit 109 acquires the travel information including the vehicle speed of the host vehicle 81 from the in-vehicle sensor 4.

[0125] In step S18, the arrival time prediction unit 109 predicts the estimated arrival time at which the host vehicle 81 will arrive at the HO prediction area based on the vehicle speed acquired in step S17, the map information acquired in step S12, etc. Then, the processors 10 and 20 terminate the HO prediction process.

[0126] Next, the HO response process in step S30 of the wireless communication control process will be described with reference to Fig. 13. Fig. 13 is a flowchart showing an example of the HO response process executed by the information processing device 1 and the communication device 2.

[0127] 13, in step S31, the communication environment related information acquisition unit 106 acquires communication environment related information for the HO prediction area or its vicinity acquired in step S16. For example, the communication environment related information acquisition unit 106 may acquire, as the communication environment related information, communication traffic between the currently connected base station 72 or a new connection destination and another vehicle 82 or other external communication device, position information and number of radio wave shielding objects such as moving objects 8 and buildings existing between the base station 72 and the vehicle 81, and weather information.

[0128] In step S32, the received radio wave strength prediction unit 110 predicts the received radio wave strength from the currently connected base station 72 in the HO prediction area at the scheduled arrival time predicted in step S18 based on the communication environment related information acquired in step S31, and obtains a predicted value R1.

[0129] In step S33, the received radio wave intensity predicting unit 110 reads out from the storage unit 13 the switching threshold value R0 acquired in step S15.

[0130] In step S34, the communication control unit 112 compares the switching threshold value read in step S33 with the predicted value R1 predicted in step S32. If the communication control unit 112 determines that the predicted value R1 exceeds the switching threshold value R0 (step S34; NO), the communication control unit 112 generates transmission control information for controlling the wireless communication unit 24 to transmit data to the currently connected base station 72 over a single line, and transmits the information to the communication device 2 (step S35). As a result, the communication device 2 transmits data to the currently connected base station 72 over a single line in accordance with the received transmission control information. On the other hand, if the communication control unit 112 determines that the predicted value R1 is equal to or less than the switching threshold value R0 (step S34; YES), the communication control unit 112 proceeds to step S36.

[0131] In step S36, the selection unit 111 identifies a communication method that can be used to transmit data to the control server 71 in the HO prediction area at the scheduled arrival time predicted in step S18, other than the communication method used with the currently connected base station 72. That is, the selection unit 111 identifies a connection destination that can be communicated with in the HO prediction area using the wireless communication unit 24, other than the currently connected base station 72. The selection unit 111 may identify candidate connection destinations in the HO prediction area, such as the drone 74 or a communication device of another vehicle 82, from point cloud data of the HO prediction area and its surroundings detected by the exterior sensor 5. Furthermore, for example, the selection unit 111 may refer to new map information from the map information acquisition unit 102, base station information from the base station information acquisition unit 105, and information from the control server 71, and identify a base station 72, roadside device 75, or satellite system 73 that can be connected to in the HO prediction area, other than the currently connected base station 72.

[0132] In step S37, the selection unit 111 generates transmission control information for controlling multiplexed transmission of data using all the communication methods identified in step S36, and transmits the generated transmission control information to the communication device 2. As a result, the communication device 2 multiplexes and transmits data using all the communication methods identified in step S36 in the HO prediction area or its vicinity in accordance with the received transmission control information.

[0133] Next, an example of a processing flow of the HO response processing that is different from the example shown in Fig. 13 will be described with reference to Fig. 14. Note that the processing of steps S31 to S36 shown in Fig. 14 is the same as the processing in the example shown in Fig. 13, and therefore description thereof will be omitted.

[0134] As shown in FIG. 14, when it is determined that the predicted value R1 is equal to or less than the switching threshold value R0 (step S34; YES), and an available communication method is identified in step S36 (step S36), the process proceeds to step S361.

[0135] In step S361, the selection unit 111 predicts the received radio wave intensity from each wireless communication destination in the HO prediction area at the scheduled arrival time for all communication methods identified in step S36.

[0136] In step S362, the selection unit 111 selects multiple communication methods having high predicted values ​​of received radio wave strength predicted in step S361 from all of the communication methods identified in step S36. The selection unit 161 may select a predetermined number or more (at least two or more) communication methods in descending order of predicted value of received radio wave strength, for example, or may select the communication methods having the first and second highest predicted values ​​of received radio wave strength and the communication methods having a predicted value of received radio wave strength higher than a predetermined value.

[0137] For example, in the example shown in FIG. 9, assume that the relationship of each predicted value predicted in step S361 is R3 < R1 < R5 ≤ R0 < R6 < R2 << R4. In this case, the selection unit 111 may select the communication method to be performed with the satellite system 73 having the predicted value R4, the communication method to be performed with the roadside unit 75 having the predicted value R2, and the communication method to be performed with the drone 74 having the predicted value R6.

[0138] In step S38, the selection unit 111 generates transmission control information for controlling the multiplex transmission of data using the plurality of communication methods selected in step S362, and transmits the transmission control information to the communication device 2. As a result, the communication device 2 multiplex-transmits data by the plurality of communication methods selected in step S362 in the HO prediction area or in the vicinity thereof according to the received transmission control information.

[0139] Next, an example of a processing flow different from the examples shown in FIGS. 13 and 14 of the HO handling process will be described with reference to FIG. 15. Note that the processing of steps S31 to S36 shown in FIG. 15 is the same as the processing in the examples shown in FIGS. 13 and 14, and thus the description thereof will be omitted.

[0140] As shown in FIG. 15, when it is determined that the predicted value R1 is less than or equal to the switching threshold value R0 (step S34; YES) and the available communication method is specified in step S36 (step S36), the process proceeds to step S363.

[0141] In step S363, the selection unit 111 predicts the received radio wave intensity from each connection destination of the wireless communication in the HO prediction area at the scheduled arrival time and the respective communication delay times when using each communication method for all the communication methods specified in step S36.

[0142] In step S364, the selection unit 111 selects a communication method with strong received radio wave intensity and small delay predicted in step S363. For example, the selection unit 111 may select a plurality of communication methods in descending order of the received radio wave intensity from communication methods with received radio wave intensity stronger than a predetermined intensity and communication delay time shorter than a predetermined time, or may select a plurality of communication methods in ascending order of the communication delay time.

[0143] For example, in the example shown in FIG. 9, the predicted communication delay time between the communication device 2 and the base station 72 during connection in the HO prediction area at the scheduled arrival time is T1, the predicted communication delay time between the roadside unit 75 is T2, the predicted communication delay time between the communication devices of other vehicles 82 is T3, the predicted communication delay time between the satellite system 73 is T4, the predicted communication delay time between the base station 72 different from the connected base station 72 is T5, and the predicted communication delay time between the drone 74 is T6.

[0144] For example, in the example shown in FIG. 9, the relationship of each predicted value predicted in step S363 is R3 < R1 < R5 ≦ R0 < R6 < R2 << R4, and T6 < T2 ≦ T3 < T5 < T1 < T4. In this case, the selection unit 111 may select the communication method performed between the drone 74 with predicted values of R6 and T6 and the communication method performed between the roadside unit 75 with predicted values of R2 and T2. As in the process shown in FIG. 14, when only the received radio wave intensity is used as the selection parameter, the communication method for communicating with the satellite system 73 is also selected, but as in the process shown in FIG. 15, by also using the communication delay time as the selection parameter, communication methods with large communication delay times can be excluded.

[0145] In step S39, the selection unit 111 generates transmission control information for controlling multiplex transmission of data using the plurality of communication methods selected in step S364, and transmits it to the communication device 2. As a result, the communication device 2 multiplexes and transmits data by the plurality of communication methods selected in step S364 in the HO prediction area or its vicinity according to the received transmission control information.

[0146] Next, an example of a processing flow of the HO response processing that is different from the example shown in Figures 13 to 15 will be described with reference to Figure 16. Note that the processing of steps S31 to S36 shown in Figure 16 is the same as the example shown in Figures 13 to 15, and therefore description thereof will be omitted.

[0147] As shown in FIG. 16, when it is determined that the predicted value R1 is equal to or less than the switching threshold value R0 (step S34; YES), and an available communication method is identified in step S36 (step S36), the process proceeds to step S365.

[0148] In step S365, the selection unit 111 predicts, for all communication methods identified in step S36, the received radio wave strength from each wireless communication connection destination in the HO prediction area at the scheduled arrival time, and the data processing volume required to transmit data when using each communication method.

[0149] In step S366, the selection unit 111 selects multiple communication methods with strong received radio wave strength and small data processing amounts predicted in step S365. For example, the selection unit 111 may select multiple communication methods in descending order of received radio wave strength from among communication methods with received radio wave strength stronger than a predetermined strength and data processing amounts smaller than a predetermined amount, or may select multiple communication methods in descending order of data processing amounts.

[0150] For example, in the example shown in Figure 16, the predicted data processing volume between the communication device 2 and the base station 72 to which it is connected in the HO prediction area at the scheduled arrival time is O1, the predicted data processing volume between the roadside unit 75 is O2, the predicted data processing volume between the communication device of another vehicle 82 is O3, the predicted data processing volume between the satellite system 73 is O4, the predicted data processing volume between a base station 72 other than the currently connected base station 72 is O5, and the predicted data processing volume between the drone 74 is O6.

[0151] For example, in the example shown in FIG. 9, assuming that the relationships of the respective predicted values predicted in step S366 are R3 < R1 < R5 ≤ R0 < R6 < R2 << R4 and O3 < O2 < O6 < O1 < O5 < O4. In this case, the selection unit 111 may select the communication method performed with the drone 74 having predicted values of R6 and T6 and the communication method performed with the roadside device 75 having predicted values of R2 and T2. As in the process shown in FIG. 16, by using both the received radio wave intensity and the data processing amount as selection parameters, the communication method performed with the communication device of another vehicle 82 having a weak received radio wave intensity and the communication method performed with the satellite system 73 having a large data processing amount can be excluded from the selection of the communication method used in the HO prediction area.

[0152] In step S40, the selection unit 111 generates transmission control information for controlling the multiplex transmission of data using the plurality of communication methods selected in step S366, and transmits the transmission control information to the communication device 2. As a result, the communication device 2 multiplex-transmits data in the plurality of communication methods selected in step S366 in the HO prediction area or in the vicinity thereof according to the received transmission control information.

[0153] Next, an example of a processing flow different from the examples shown in FIGS. 13 to 16 of the HO handling will be described with reference to FIG. 17. Note that the processing of steps S31 to S36 shown in FIG. 17 is the same as the processing in the examples shown in FIGS. 13 to 16, and thus the description thereof is omitted.

[0154] As shown in FIG. 17, when it is determined that the predicted value R1 is less than or equal to the switching threshold value R0 (step S34; YES) and the available communication method is specified in step S36 (step S36), the process proceeds to step S367.

[0155] In step S367, the selection unit 111 determines the priority order of the selection parameters used for the selection of the communication method. The selection unit 111 may, for example, assign priorities in the order of received radio wave intensity, communication delay time, and data processing amount.

[0156] In step S368, the selection unit 111 predicts the predicted values ​​of the selection parameters with the highest priority determined in step S367 for all the communication methods identified in step S36. For example, if the priorities of the selection parameters are received signal strength, communication delay time, and data processing amount, in that order, the selection unit 111 may predict the received signal strength and communication delay time for each communication method in the HO prediction area at the scheduled arrival time.

[0157] In step S369, the selection unit 111 selects a plurality of communication methods using the predicted values ​​of the selection parameters with the highest priorities predicted in step S368.

[0158] In step S41, the selection unit 111 generates transmission control information for controlling multiplexed transmission of data using the multiple communication methods selected in step S369, and transmits the generated transmission control information to the communication device 2. As a result, the communication device 2 multiplexes and transmits data using the multiple communication methods selected in step S369 in the HO prediction area or its vicinity, in accordance with the received transmission control information.

[0159] According to the embodiment described above, the following effects are achieved.

[0160] The communication system 100 according to this embodiment is a communication system 100 that is mounted on a vehicle 81 and includes a wireless communication unit 24 that can transmit and receive data using a plurality of communication methods including a wireless communication method with a base station 72, and includes a route information acquisition unit 104 that generates planned route information regarding a route that the vehicle 81 is scheduled to travel based on input information, acquires the planned route information, a base station information acquisition unit 105 that acquires base station information including position information of each of a plurality of base stations 72 that cover the communication area of ​​the route included in the acquired planned route information, a threshold acquisition unit 107 that acquires a switching threshold R0 of received radio wave intensity that causes the wireless communication unit 24 to switch to a new wireless communication connection destination, and a threshold acquisition unit 108 that acquires a threshold R0 of received radio wave intensity that causes the wireless communication unit 24 to switch to a new wireless communication connection destination. The device is equipped with an HO prediction area acquisition unit 108 that acquires, based on location information, an HO prediction area in which a handover is predicted to occur, in which the wireless communication unit 24 switches from the base station 72 currently connected to to another base station 72, on a route including planned route information; an arrival time prediction unit 109 that predicts the planned arrival time at which the vehicle 81 will arrive at the HO prediction area B; a received radio wave strength prediction unit 110 that predicts the received radio wave strength of radio waves from the base station 72 in the HO prediction area at the planned arrival time before arriving at the HO prediction area; and a selection unit 111 that selects the communication method to be used by the wireless communication unit 24 in the HO prediction area based on a comparison result between the received radio wave strength predicted by the received radio wave strength prediction unit 110 and a switching threshold R0.

[0161] This allows the system to predict the communication environment in HO area B before a handover occurs by acquiring information such as the HO prediction area and its expected arrival time in advance and comparing the predicted value R1 of the received radio wave strength from the HO-destination base station in the predicted HO area B with the switching threshold R0. Then, in an area where a deterioration in communication quality due to a handover is predicted, a communication method can be selected to deal with the deterioration in communication quality in that area. Therefore, even if the communication environment changes due to a handover, the reliability of wireless communication can be ensured, improving the reliability of, for example, vehicle control or assistance.

[0162] Furthermore, the communication system 100 according to this embodiment further includes a communication control unit 112 that multiplexes and transmits the same packet to a new connection destination using a plurality of different communication methods when the predicted received radio wave strength is equal to or less than the switching threshold R0, and transmits the same data to the currently connected base station 72 using one communication method when the predicted received radio wave strength exceeds the switching threshold R0, and a selection unit 111 selects a plurality of different communication methods to be used by the wireless communication unit 24 for multiplex transmission when the predicted received radio wave strength is equal to or less than the switching threshold R0.

[0163] This allows data to be transmitted by multiplexing using different communication methods in areas where a drop in communication quality due to handover is expected, allowing the destination to perform processing such as adopting the packet that arrived first from communication device 2. Therefore, even if the communication environment changes due to handover or the like, the reliability of wireless communication can be ensured, improving the reliability of, for example, vehicle control or assistance.

[0164] In addition, in the communication system 100 according to this embodiment, the selection unit 111 predicts the received radio wave strength of radio waves from the wireless communication destination for each of the plurality of communication methods in the HO prediction area at the scheduled arrival time, and selects the plurality of different communication methods in descending order of the predicted received radio wave strength.

[0165] This allows data to be transmitted by multiplex transmission using a communication method with a high predicted value of received radio wave strength, thereby enabling smoother data transmission.

[0166] In addition, in the communication system 100 according to this embodiment, the selection unit 111 predicts the communication delay time of wireless communication for each of the plurality of communication methods in the HO prediction area at the scheduled arrival time, and selects the plurality of different communication methods in order of the predicted communication delay time in the order of shortest.

[0167] This allows data to be transmitted by multiplexing using different communication methods with small communication delay times in areas where a deterioration in communication quality due to handover is expected, thereby enabling data to be transmitted with less delay.

[0168] Furthermore, in the communication system 100 according to this embodiment, the selection unit 111 predicts the amount of data processing required for transmitting data when using each of the plurality of communication methods in the HO prediction area at the scheduled arrival time, and selects the plurality of different communication methods in descending order of the predicted amount of data processing.

[0169] This allows data to be transmitted by multiplex transmission using a communication method with a small amount of data processing in areas where a deterioration in communication quality due to handover is expected, thereby enabling transmission with low power consumption and low cost.

[0170] In addition, in the communication system 100 according to this embodiment, the selection unit 111 determines the priority of selection parameters related to communication quality and data processing in the HO prediction area at the scheduled arrival time, and selects multiple different communication methods based on the parameters with the highest priority.

[0171] This allows the communication method to be selected according to the priority of the parameters, making it possible to transmit data appropriately depending on the situation.

[0172] In the communication system 100 according to this embodiment, the selection parameters relating to communication quality and data processing are the received radio wave intensity, the communication delay time of wireless communication, and the amount of data processing required for data transmission.

[0173] This allows a communication method to be selected according to the priority of received radio wave intensity, communication delay time, and data processing volume, thereby enabling more appropriate data transmission according to the situation.

[0174] The communication system 100 according to this embodiment also includes an information processing device 1 having a route information acquisition unit 104, a base station information acquisition unit 105, a threshold acquisition unit 107, an HO prediction area acquisition unit 108, an arrival time prediction unit 109, a received radio wave intensity prediction unit 110, and a selection unit 111, and a communication device 2 having a wireless communication unit 24 that performs bidirectional communication with an external communication device 7 and the information processing device 1.

[0175] As a result, by separating the communication device 2 that performs wireless communication with the external communication device 7 and the like from the information processing device 1 that performs calculation processing using various information such as prediction of the HO area B and prediction of the received radio wave strength, the processing of the communication device 2 can be specialized for wireless communication with the external communication device 7. This allows for smoother wireless communication and more reliably ensures the reliability of wireless communication even when the communication environment in the HO area B is degraded.

[0176] In addition, in the communication system 100 according to this embodiment, the information processing device 1 is capable of communicating with the communication device 2, an in-vehicle sensor 4 that detects movement information of the vehicle 81, an external sensor 5 that detects the situation around the vehicle 81, and an HMI 3 that accepts input operations by the driver of the vehicle 81 and outputs information to the driver, and generates planned route information, predicts the HO prediction area, predicts the planned arrival time, and predicts the received radio wave strength from the base station 72 in the HO prediction area based on the information acquired from the communication device 2, the in-vehicle sensor 4, the external sensor 5, and the HMI 3.

[0177] This makes it possible to more accurately predict the received signal strength from the HO-destination base station in the HO prediction area, thereby more reliably maintaining communication reliability even when the communication environment deteriorates.

[0178] In the communication system 100 according to this embodiment, the HMI 3 accepts input operations by the driver of a plurality of point information used for generating planned route information by the information processing device 1, and transmits the information to the information processing device 1.

[0179] This makes it easier to create a planned driving route for the vehicle 81.

[0180] The program according to this embodiment is a program to be executed by the computer 16, 28 of the communication system 100, which is mounted on the vehicle 81 and includes a wireless communication unit 24 capable of transmitting and receiving data using a plurality of communication methods including a wireless communication method with a base station 72, and which generates planned route information regarding a route that the vehicle 81 is scheduled to travel based on input information, and includes a route information acquisition step of acquiring the planned route information, a base station information acquisition step of acquiring base station information including position information of each of a plurality of base stations 72 that cover the communication area of ​​the route included in the acquired planned route information, and a receiving radio wave strength switching threshold R0 that causes the wireless communication unit 24 to switch to a new wireless communication destination when the received radio wave strength from the destination base station 72 has decreased. the HO predicted area acquisition step of acquiring an HO predicted area in which a handover is predicted to occur, in which the wireless communication unit 24 switches from the base station 72 to which it is currently connected, to another base station 72, on a route including the planned route information, based on at least the position information of the base station 72; an arrival time prediction step of predicting the planned arrival time at which the vehicle 81 will arrive in the HO predicted area; a received radio wave strength prediction step of predicting the received radio wave strength of radio waves from the base station 72 in the HO predicted area at the planned arrival time before arriving at the HO predicted area; and a selection step of selecting a communication method to be used by the wireless communication unit 24 in the HO predicted area based on the result of comparing the received radio wave strength predicted by the received radio wave strength prediction step with the switching threshold R0.

[0181] The communication method according to this embodiment is a communication method using a wireless communication unit 24 that is mounted on the vehicle 81 and is capable of transmitting and receiving data using a plurality of communication methods including a wireless communication method with a base station 72, and includes a route information acquisition step in which planned route information regarding a route that the vehicle 81 is scheduled to travel is generated based on input information, and the method acquires the planned route information; a base station information acquisition step in which base station information including position information of each of a plurality of base stations 72 that cover the communication area of ​​the route included in the acquired planned route information is acquired; and a threshold acquisition step in which, when the received radio wave strength of the radio waves from the destination base station 72 has decreased, the wireless communication unit 24 acquires a threshold R0 for switching the wireless communication to a new destination. the HO prediction area acquisition step of acquiring an HO prediction area in which a handover is predicted to occur, in which the wireless communication unit 24 switches from the base station 72 to which it is currently connected to another base station 72, on a route including the planned route information, based on at least the position information of the base station 72; an arrival time prediction step of predicting the planned arrival time at which the vehicle 81 will arrive in the HO prediction area; a received radio wave strength prediction step of predicting the received radio wave strength of radio waves from the base station 72 in the HO prediction area at the planned arrival time before arriving at the HO prediction area; and a selection step of selecting a communication method to be used by the wireless communication unit 24 in the HO prediction area based on a comparison result between the received radio wave strength predicted by the received radio wave strength prediction step and a switching threshold R0.

[0182] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be modified as appropriate. [Explanation of symbols]

[0183] 1. Information processing equipment 2. Communications equipment 3. HMI 4 In-vehicle sensors 5. Outside vehicle sensors 8 Mobile 24 Radio Communication Department 72 Base station 81 Vehicle 100 Communication Systems 104 Route information acquisition unit 105 Base station information acquisition unit 107 Threshold acquisition unit 108 Handover prediction area acquisition unit (HO prediction area acquisition unit) 109 Arrival time prediction unit 110 Received signal strength prediction unit 111 Selection section 112 Communication control unit B. Handover Area (HO Area) R0 switching threshold

Claims

1. A communication system equipped with a wireless communication unit mounted on a mobile body and capable of transmitting and receiving data using a plurality of communication methods including a wireless communication method with a base station, a route information acquisition unit that generates route information regarding a route along which the mobile object is scheduled to travel based on input information and acquires the route information; a base station information acquisition unit that acquires base station information including location information of each of a plurality of base stations that cover a communication area of ​​the route included in the acquired route information; a threshold acquisition unit that acquires a switching threshold for received radio wave intensity that causes the wireless communication unit to switch to a new wireless communication connection; a handover predicted area acquisition unit that acquires, based on at least the location information, a handover predicted area in which a handover is predicted to occur in which the wireless communication unit switches from a base station currently connected to another base station along a route included in the route information; and an arrival time prediction unit that predicts an arrival time at which the mobile object will arrive in the handover prediction area; a received radio wave intensity prediction unit that predicts received radio wave intensity of radio waves from the base station in the handover prediction area at the arrival time before the handover prediction area is reached; A communication system comprising: a selection unit that selects a communication method to be used by the wireless communication unit in the handover prediction area based on a comparison result between the received radio wave strength predicted by the received radio wave strength prediction unit and the switching threshold.

2. a communication control unit that, when the predicted received radio wave strength is equal to or less than the switching threshold, multiplexes and transmits the same packet to the new connection destination using a plurality of different communication methods, and, when the predicted received radio wave strength exceeds the switching threshold, transmits the same data to the currently connected base station using one communication method; The communication system according to claim 1 , wherein the selection unit selects a plurality of different communication methods to be used by the wireless communication unit for the multiplex transmission when the predicted received radio wave intensity is equal to or less than the switching threshold.

3. 3. The communication system according to claim 2, wherein the selection unit predicts received radio wave strength of radio waves from wireless communication destinations for each of the plurality of communication methods in the handover prediction area at the arrival time, and selects the plurality of different communication methods in descending order of the predicted received radio wave strength.

4. 3. The communication system according to claim 2, wherein the selection unit predicts a communication delay time of wireless communication for each of the plurality of communication methods in the handover prediction area at the arrival time, and selects the plurality of different communication methods in order of the predicted communication delay time.

5. 3. The communication system according to claim 2, wherein the selection unit predicts a data processing amount required for transmitting data when using each of the plurality of communication methods in the handover prediction area at the arrival time, and selects the plurality of different communication methods in order of decreasing predicted data processing amount.

6. 3. The communication system according to claim 2, wherein the selection unit determines priorities of parameters related to communication quality and data processing in the handover prediction area at the arrival time, and selects the plurality of different communication methods based on the parameters with the highest priorities.

7. 7. The communication system according to claim 6, wherein the parameters relating to communication quality and data processing are the received radio wave intensity, a communication delay time of wireless communication, and a data processing amount required for data transmission.

8. an information processing device including the route information acquisition unit, the base station information acquisition unit, the threshold acquisition unit, the handover predicted area acquisition unit, the arrival time prediction unit, the received radio wave intensity prediction unit, and the selection unit; The communication system according to claim 1 , further comprising: a communication device having the wireless communication unit for performing two-way communication with an external communication device and the information processing device.

9. the information processing device is capable of communicating with the communication device, an in-vehicle sensor that detects movement information of the mobile body, an outside sensor that detects a situation around the mobile body, and an input / output device that accepts an input operation by a driver of the mobile body and outputs information to the driver; 9. The communication system according to claim 8, wherein the route information is generated, the handover predicted area is predicted, the arrival time is predicted, and the received radio wave strength from the base station in the handover predicted area is predicted based on information acquired from the communication device, the in-vehicle sensor, the outside-vehicle sensor, and the input / output device.

10. The communication system according to claim 9 , wherein the input / output device receives an input operation by a driver of a plurality of pieces of location information used in generating the route information by the information processing device, and transmits the information to the information processing device.

11. A program executed by a computer in a communication system equipped with a wireless communication unit mounted on a mobile body and capable of transmitting and receiving data using a plurality of communication methods including a wireless communication method with a base station, a route information acquisition step of generating route information relating to a route along which the mobile object is scheduled to travel based on the input information and acquiring the route information; a base station information acquisition step of acquiring base station information including location information of each of a plurality of base stations that cover a communication area of ​​the route included in the acquired route information; a threshold value acquisition step of acquiring a switching threshold value for received radio wave intensity that causes the wireless communication unit to switch to a new wireless communication connection; a handover predicted area acquisition step of acquiring, based on at least the location information, a handover predicted area in which a handover is predicted to occur in which the wireless communication unit switches from a base station currently connected to another base station along a route included in the route information; an arrival time prediction step of predicting an arrival time at which the mobile unit will arrive in the handover prediction area; a received radio wave intensity prediction step of predicting received radio wave intensity of radio waves from the base station in the handover prediction area at the arrival time before the handover prediction area is reached; and a selection process for selecting a communication method to be used by the wireless communication unit in the handover prediction area based on a comparison result between the received radio wave strength predicted by the received radio wave strength prediction process and the switching threshold value.

12. A communication method applied to a communication system equipped with a wireless communication unit mounted on a mobile body and capable of transmitting and receiving data using a plurality of communication methods including a wireless communication method with a base station, comprising: a route information acquisition step of generating route information relating to a route along which the mobile object is scheduled to travel based on the input information and acquiring the route information; a base station information acquisition step of acquiring base station information including location information of each of a plurality of base stations that cover a communication area of ​​the route included in the acquired route information; a threshold acquisition step of acquiring a threshold for switching the received radio wave strength, which causes the wireless communication unit to switch the wireless communication to a new destination when the received radio wave strength from the destination base station has decreased; a handover predicted area acquisition step of acquiring, based on at least the location information, a handover predicted area in which a handover is predicted to occur in which the wireless communication unit switches from a base station currently connected to another base station along a route included in the route information; an arrival time prediction step of predicting an arrival time at which the mobile unit will arrive in the handover prediction area; a received radio wave intensity prediction step of predicting received radio wave intensity of radio waves from the base station in the handover prediction area at the arrival time before the handover prediction area is reached; a selection step of selecting a communication method to be used by the wireless communication unit in the handover prediction area based on a comparison result between the received radio wave strength predicted in the received radio wave strength prediction step and the switching threshold value.

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