Data transmission device, data transmission method, and data transmission program

Abstract

This invention relates to a data transmission apparatus, a data transmission method, and a data transmission program. The data transmission apparatus (100) includes: a wireless communication unit (101) for wireless communication with an external communication device; a travel path information acquisition unit (108) for acquiring the future travel path of a mobile body; a propagation environment information acquisition unit (109) for acquiring propagation environment information of the radio wave propagation path used in wireless communication on the travel path; a speed information acquisition unit (103) for acquiring the moving speed of the mobile body; a conversion unit (110) for converting the relationship between the travel path and the propagation environment information into data time slots defined by the communication speed per unit time based on the moving speed; an allocation unit (111) for sequentially allocating data starting from the data time slot with the faster communication speed; and a transmission instruction unit (112) for instructing the wireless communication unit to transmit the data allocated to the data time slot when data is allocated in the data time slot corresponding to the current time.

Description

[0001] Cross-references to related applications

[0002] This application is based on Japanese Patent Application No. 2020-161477, filed on September 25, 2020, the contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to a data transmission device, such as one that is mainly mounted on a mobile body, or a data transmission device that communicates directly or indirectly with a mobile body, which transmits data based on a communication plan for efficient data transmission. Background Technology

[0004] With the widespread adoption of wireless communication, opportunities for wireless communication in various settings have increased. Particularly in mobile vehicles such as automobiles, technologies utilizing high-capacity cellular communication, vehicle-to-everything (V2X) communication, and road-to-road (Road-to-Road) communication for driver assistance and autonomous driving control have garnered significant attention. Consequently, vehicles now possess communication capabilities, enhancing their so-called connectivity.

[0005] Here, it is known that in wireless communication, due to mutual interference of radio waves, the transmission and reception levels of radio waves vary depending on the location; this phenomenon is generally called fading. Since movement is a prerequisite in mobile vehicles such as automobiles, if the communication quality changes that occur with movement can be known in advance, countermeasures can be taken.

[0006] For example, Patent Document 1 describes a communication resource map showing the correspondence between a location and the amount of communication resources that are presumed to be usable for communication at that location.

[0007] Furthermore, Patent Document 2 describes the use of information that statistically processes the relationship between location and communication speed to predict the communication quality along the communication path.

[0008] Patent Document 1: Japanese Patent Application Publication No. 2019-203823

[0009] Patent Document 2: Japanese Patent Application Publication No. 2019-140563

[0010] Here, the inventors have discovered the following issues.

[0011] By using the radio map that indicates a place on a map and a state or an inference result of a radio wave propagation path in the place, it is possible to know in advance a state of a radio wave propagation path on a future movement path. Therefore, it is possible to make a communication plan for the future based on the movement path and the state of the radio wave propagation path. However, when communication is performed, since it is necessary to always acquire a current position of the vehicle and compare it with the radio map, the amount of computation increases.

[0012] In addition, when a communication plan is made, for example, in a case where a deadline is set for data to be transmitted and received, in order to complete the transmission and reception within the deadline, time management is necessary. Therefore, it is not possible to make a communication plan only by the radio map and the current position. SUMMARY

[0013] An object of the present disclosure is to efficiently transmit and receive data based on a communication plan.

[0014] More specifically, an object is to efficiently transmit and receive data by introducing an element of time.

[0015] A data transmission device of one aspect of the present disclosure is a data transmission device mounted on a mobile body, in which:

[0016] a wireless communication section that performs wireless communication with an external communication device;

[0017] a data holding section that holds data transmitted from the wireless communication section;

[0018] a travel path information acquisition section that acquires a future travel path of the mobile body;

[0019] a propagation environment information acquisition section that acquires propagation environment information of a radio wave propagation path used in the wireless communication on the travel path;

[0020] a speed information acquisition section that acquires a movement speed of the mobile body;

[0021] a conversion section that converts a relationship between the travel path and the propagation environment information into data slots defined by a communication speed per unit time based on the movement speed;

[0022] an allocation section that allocates the data in order from the data slot in which the communication speed is faster; and

[0023] a transmission instruction section that instructs the wireless communication section to transmit the data allocated to the data slot in a case where the data is allocated to the data slot corresponding to a current time.

[0024] A data transmission device of another aspect of the present disclosure is a data transmission device that transmits data to a mobile body, in which:

[0025] a transmission unit that transmits the data to a communication device outside that performs wireless communication with the mobile body;

[0026] a data storage unit that stores the data transmitted from the transmission unit;

[0027] a travel path information acquisition unit that acquires a future travel path of the mobile body;

[0028] a propagation environment information acquisition unit that acquires propagation environment information of a wave propagation path used in the wireless communication on the travel path;

[0029] a reception unit that receives a moving speed of the mobile body;

[0030] a conversion unit that converts a relationship between the travel path and the propagation environment information into data slots defined by communication speeds per unit time, based on the moving speed;

[0031] an allocation unit that allocates the data in order from the data slots in which the communication speeds are faster; and

[0032] a transmission instruction unit that instructs the transmission unit to transmit the data allocated to the data slots, in a case where the data is allocated in the data slots corresponding to a current time.

[0033] Another data transmission method of the present disclosure is a data transmission method performed by a data transmission device mounted on a mobile body and having a wireless communication unit that performs wireless communication with a communication device outside, in which

[0034] a future travel path of the mobile body is acquired,

[0035] propagation environment information of a wave propagation path used in the wireless communication on the travel path is acquired,

[0036] a moving speed of the mobile body is acquired,

[0037] a relationship between the travel path and the propagation environment information is converted into data slots defined by communication speeds per unit time, based on the moving speed,

[0038] the data is allocated in order from the data slots in which the communication speeds are faster,

[0039] the wireless communication unit is instructed to transmit the data allocated to the data slots, in a case where the data is allocated in the data slots corresponding to a current time.

[0040] Another data transmission method of the present disclosure is a data transmission method executed by a data transmission device having a transmission section that transmits data to an external communication device that performs wireless communication with a mobile body, wherein

[0041] acquiring a future travel path of the mobile body,

[0042] acquiring propagation environment information of a wave propagation path used in the wireless communication on the travel path,

[0043] receiving a moving speed of the mobile body,

[0044] converting a relationship between the travel path and the propagation environment information into data slots defined by communication speeds per unit time based on the moving speed,

[0045] allocating the data in order from the data slot with a faster communication speed,

[0046] in a case where the data is allocated in the data slot corresponding to a current time, instructing the transmission section to transmit the data allocated to the data slot.

[0047] Another data transmission program of the present disclosure is a data transmission program that can be executed by a data transmission device mounted on a mobile body and having a wireless communication section that performs wireless communication with an external communication device, wherein

[0048] acquiring a future travel path of the mobile body,

[0049] acquiring propagation environment information of a wave propagation path used in the wireless communication on the travel path,

[0050] acquiring a moving speed of the mobile body,

[0051] converting a relationship between the travel path and the propagation environment information into data slots defined by communication speeds per unit time based on the moving speed,

[0052] allocating the data in order from the data slot with a faster communication speed,

[0053] in a case where the data is allocated in the data slot corresponding to a current time, instructing the wireless communication section to transmit the data allocated to the data slot.

[0054] Another data transmission program of the present disclosure is a data transmission program that can be executed by a data transmission device having a transmission section that transmits data to an external communication device that performs wireless communication with a mobile body, wherein

[0055] acquiring a future travel path of the mobile body,

[0056] acquiring propagation environment information of a radio wave propagation path used in the wireless communication on the travel path,

[0057] receiving a moving speed of the mobile body,

[0058] based on the moving speed, converting a relationship between the travel path and the propagation environment information into data slots defined by a communication speed per unit time,

[0059] allocating the data in order from the data slot of the communication speed,

[0060] in a case where the data is allocated in the data slot corresponding to a current time, instructing the transmission section to transmit the data allocated to the data slot.

[0061] Further, the numbers in parentheses marked in the claims indicate the correspondence relationship of the present application with the embodiments described later, and are not intended to limit the present application.

[0062] According to the above-described structure, data can be efficiently transmitted and received based on a communication plan. BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 is a diagram showing the overall structure of the embodiment of the present disclosure.

[0064] Figure 2 is a block diagram showing a structure example of the data transmission device of Embodiment 1 of the present disclosure.

[0065] Figure 3 is an explanatory diagram explaining the operation of the wave environment information acquisition section and the conversion section of the data transmission device of Embodiment 1 and Embodiment 2 of the present disclosure.

[0066] Figure 4 is an explanatory diagram explaining the operation of the allocation section of the data transmission device of Embodiment 1 and Embodiment 2 of the present disclosure.

[0067] Figure 5 is a flowchart showing the operation of the data transmission device of Embodiment 1 of the present disclosure.

[0068] Figure 6 is a block diagram showing a structure example of the data transmission device of Embodiment 2 of the present disclosure.

[0069] Figure 7 is a flowchart showing the operation of the data transmission device of Embodiment 2 of the present disclosure.

[0070] Figure 8 is a diagram showing the overall structure of a modification of Embodiment 2 of the present disclosure. DETAILED DESCRIPTION

[0071] Hereinafter, with reference to the drawings, the embodiments of the present disclosure will be described.

[0072] Further, the present invention shown below refers to the invention recited in the claims, and is not limited to the following embodiments. Also, at least the statements within the double quotation marks refer to the statements recited in the claims, and similarly are not limited to the following embodiments.

[0073] The structures and methods recited in the dependent claims of the claims are arbitrary structures and methods in the invention recited in the independent claim of the claims. The structures and methods of the embodiments corresponding to the structures and methods recited in the dependent claims, and the structures and methods recited in the embodiments but not recited in the claims are arbitrary structures and methods in the present invention. The structures and methods recited in the embodiments in the case where the recitations in the claims are broader than the recitations in the embodiments also mean examples of the structures and methods of the present invention, and are arbitrary structures and methods in the present invention. In any case, the structures and methods recited in the independent claim of the claims become necessary structures and methods of the present invention.

[0074] The effects recited in the embodiments are effects in the case where the structures of the embodiments are examples of the present invention, and are not necessarily effects possessed by the present invention.

[0075] In the case where a plurality of embodiments exist, the structures disclosed in each embodiment are not closed only in each embodiment, and can be combined across the embodiments. For example, the structure disclosed in one embodiment can be combined with other embodiments. Also, the structures disclosed in a plurality of embodiments can be combined.

[0076] The problem recited in the present invention is not a publicly known problem, but is a problem thought of by the inventor alone, and is a fact that the invention is surely inventive together with the structures and methods of the present invention.

[0077] 1. Overall structure example of each embodiment

[0078] First, the use of the terms Figure 1 The devices related in each embodiment and their mutual relationship, and the overall structure example of each embodiment will be described.

[0079] The in-vehicle device 1 mounted on a vehicle corresponds to the data transmission device 100 of Embodiment 1, and transmits various data to the information accumulation server device 3 via the base station device 4.

[0080] The information distribution server device 2 is equivalent to the data transmission device 200 in embodiment 2, which transmits various data to the vehicle-mounted device 1 via the base station device 4.

[0081] The base station device 4 (equivalent to an "external communication device") is a device that conducts wireless communication with the vehicle-mounted device 1.

[0082] The wireless communication between the base station device 4 and the vehicle-mounted device 1 can utilize, for example, IEEE 802.11 (WiFi, registered trademark), IEEE 802.16 (WiMAX, registered trademark), W-CDMA (Wideband Code Division Multiple Access), HSPA (High Speed ​​Packet Access), LTE (Long Term Evolution), LTE-A (Long Term Evolution Advanced), 4G, 5G, etc. Alternatively, it can utilize DSRC (Dedicated Short Range Communication).

[0083] The communication methods between the information distribution server device 2 and the base station device 4, and between the information storage server device 3 and the base station device 4, can be any of the following: wired communication, wireless communication, or both wired and wireless communication. For example, if the wireless communication method between the base station device 4 and the vehicle-mounted device 1 is 4G, then since the base station device 4 is equivalent to an eNB, the wired line from the communication service provider is in front of the eNB. However, if the wireless communication method between the base station device 4 and the vehicle-mounted device 1 is WiFi, then since the base station device 4 is equivalent to an access point (AP), the communication between the access point and the router can be either wireless or wired.

[0084] Radio wave image server device 5 stores radio wave images and sends them to the requested destination. For example, radio wave image server device 5 sends radio wave images to vehicle-mounted device 1 and information distribution server device 2 based on radio wave image requests or periodically. The communication network used for transmitting the radio wave images can be either wired or wireless communication. Furthermore, in Figure 1 In the case of transmitting radio waves from the radio wave server device 5 to the vehicle-mounted device 1, a communication network that does not pass through the base station device 4 can be used, but a communication network that passes through the base station device 4 can also be used.

[0085] Here, the so-called radio wave map refers to the set of states or inferences about the propagation paths of radio waves at a specific location. For example, it refers to the set after mapping RSSI and transmission bit rate according to each grid point on the map.

[0086] exist Figure 1 In this system, the radio wave map server device 5 stores the state or inference results of the radio wave propagation path provided by the wireless communication mode of the base station device 4, and makes them available for use. Since the radio wave propagation path has an uplink and a downlink, the radio wave map server device 4 preferably stores radio wave maps of both.

[0087] For the radio wave diagram used in the downlink, the information used to evaluate the reception status of the downlink can be correlated with the location information. For example, the received signal strength when the detection vehicle receives the reference signal transmitted by the base station device 4 is measured, and the received radio wave diagram is generated by collecting this strength. For example, the RSSI, RSRP, or RSRQ of the reference signal are equivalent to this.

[0088] For the uplink radio waveform, the information used to evaluate the uplink reception status can be correlated with the location information. For example, the reception strength of the reference signal transmitted by the probe vehicle when the base station device 4 receives it is measured, and the reception waveform is generated by collecting this strength together with the location information of the probe vehicle. For example, the RSSI, RSRP, or RSRQ of the reference signal are equivalent to this. Alternatively, the transmission waveform can be generated by collecting the average transmission bit rate (bit / s) when the probe vehicle transmits data together with the location information of the probe vehicle.

[0089] In principle, the uplink wave diagram is used in the evaluation of the uplink wave propagation path, and the downlink wave diagram is used in the evaluation of the downlink wave propagation path. In Embodiment 1, since the vehicle-mounted device 1 functions as a data transmission device 100 and utilizes the uplink, the uplink wave diagram is used. In Embodiment 2, since the information distribution server device 2 functions as a data transmission device 200 and utilizes the downlink, the downlink wave diagram is used.

[0090] However, if the propagation environment of the uplink and downlink can be evaluated as the same, the radio wave diagram used for the downlink can be used in the evaluation of the uplink, and vice versa. For example, a TDD mode using the same frequency band can be cited. As another example, situations where obstructions such as buildings are expected to cause similar changes in the propagation environment in both the uplink and downlink.

[0091] Traffic light 6 sends the signal type, which is the current signal color, and the remaining time before the signal type changes. The signal type includes at least a stop signal (indicating a stop) and a proceed signal (indicating a proceed). In many countries, such as Japan and the United States, the former is red and the latter is blue. For example, if the current light is red and there are 30 seconds remaining, the light will change from red to blue after 30 seconds.

[0092] Traffic light 6 transmits the signal type and remaining time using inter-rail communication, and on-board unit 1 receives the signal type and remaining time. However, traffic light 6 can also transmit this information using methods other than inter-rail communication. For example, it can also transmit from traffic light 6 to base station unit 4 via a wired communication network. In this case, on-board unit 1 receives this information from base station unit 4 using wireless communication.

[0093] GNSS satellite 7 is a satellite that transmits positioning signals; examples include GPS and differential GPS. The vehicle-mounted device 1 receives the positioning signals and, as needed, uses gyroscopes and radar sensors to obtain current location information indicating the vehicle's current position.

[0094] Furthermore, the information distribution server device 2, the information storage server device 3, and the radio wave image server device 5 are different devices, but at least two of their functions can be achieved through the same server device.

[0095] In addition, Figure 1 In this embodiment, the information distribution server device 2 is assumed to remain stationary, but it can also be mounted in a different vehicle than the vehicle carrying the vehicle-mounted device 1, and data can be transmitted to the vehicle-mounted device 1 via the base station device 4. This will be explained in a variation of embodiment 2.

[0096] 2. Implementation Method 1

[0097] (1) Structure of the data transmission device 100

[0098] use Figure 2 The structure of the data transmission device 100 in Embodiment 1 will be described below. In this embodiment, Figure 1 The vehicle-mounted device 1 is equivalent to the data transmission device 100.

[0099] The data transmission device 100 is a device "mounted" on a vehicle that is a "mobile body".

[0100] Here, "moving body" refers to an object capable of movement at any speed. It also includes situations where the moving body is stationary. Examples include cars, motorcycles, bicycles, pedestrians, ships, airplanes, and the objects carried by them, but not limited to these.

[0101] In addition to cases where the object is directly fixed to the moving body, "carrying" also includes cases where the object moves with the moving body even though it is not fixed to it. Examples include cases where the object is held by a person riding the moving body, or cases where the object is carried on cargo placed on the moving body.

[0102] The data transmission device 100 includes a wireless communication unit 101, a location information acquisition unit 102, a speed information acquisition unit 103, a data storage unit 104, a travel path storage unit 105, a radio wave diagram storage unit 106, and a control unit 107. Furthermore, the control unit 107 implements a travel path information acquisition unit 108, a propagation environment information acquisition unit 109, a conversion unit 110, a distribution unit 111, a transmission instruction unit 112, and a traffic light information acquisition unit 113.

[0103] The data transmission device 100 can be composed of a general-purpose CPU (Central Processing Unit), volatile memory such as RAM, non-volatile memory such as ROM, flash memory, or hard disk, various interfaces, and an internal bus connecting them. Furthermore, it can be configured to perform functions by executing software on this hardware. Figure 2 The functions of each functional module are recorded in the document.

[0104] Of course, the data transmission device 100 can also be implemented using dedicated hardware such as LSI.

[0105] In this embodiment, the data transmission device 100 is assumed to be an electronic control unit (ECU, hereinafter referred to as ECU) as a semi-finished product, but it is not limited thereto. For example, as a component, it can be a semiconductor circuit or a semiconductor module; as a finished product, it can be a personal computer (PC), a smartphone, a mobile phone, or a navigation system.

[0106] Furthermore, the data transmission device 100 can be composed of multiple ECUs, in addition to a single ECU. For example, a communication ECU can be responsible for communication with external systems.

[0107] The wireless communication unit 101 performs "wireless communication" with the base station device 4, which is an external communication device. Various communication methods can be used for wireless communication as described above, but in this embodiment, 4G or 5G is assumed to be a cellular communication method. Furthermore, multiple communication methods may be used for wireless communication.

[0108] Here, "wireless communication" refers to sending and / or receiving signals wirelessly.

[0109] Furthermore, when the data transmitting device 100 is a smartphone, mobile phone, tablet computer, etc., the wireless communication unit 101 can communicate wirelessly or wiredly with a wireless communication unit installed on the vehicle side, and the wireless communication unit installed on the vehicle side can communicate wirelessly with the base station device 4. When wireless communication is used between the wireless communication unit 101 and the wireless communication unit installed on the vehicle side, short-range wireless communication such as BLE and Bluetooth (registered trademark) can be used. In this case, the wireless communication unit 101 also communicates wirelessly with the base station device 4 via the wireless communication unit installed on the vehicle side.

[0110] The location information acquisition unit 102 acquires location information indicating the current location of the vehicle. The location information acquisition unit 102 mainly consists of a positioning receiver for a satellite positioning (GNSS) device. For the positioning receiver, it is sufficient to install a positioning receiver corresponding to the satellite system being used.

[0111] In addition to the positioning receiver, the location information acquisition unit 102 also includes a device for supplying correction information for correcting the location information. For example, inertial sensors such as gyroscope sensors and accelerometers, laser sensors, and map information databases can also be included in the location information acquisition unit 102.

[0112] In this embodiment, the location information acquisition unit 102 is included in the data transmission device 100, but it may also be disposed outside the data transmission device 100. In this case, the interface for receiving location information from the outside is equivalent to the location information acquisition unit 102.

[0113] The speed information acquisition unit 103 is, for example, a vehicle speed sensor, which detects and acquires the vehicle's moving speed. In this embodiment, the speed information acquisition unit 103 is included in the data transmission device 100, but it may also be provided externally to the data transmission device 100. In this case, the interface for receiving the moving speed from the outside corresponds to the speed information acquisition unit 103.

[0114] The data storage unit 104 stores the "data" transmitted from the wireless communication unit 101. Examples of data include image data captured by the vehicle-mounted camera, speed, acceleration, or location information, and other data related to the vehicle's movement and condition, but are not limited to these.

[0115] Here, "data" only needs to be informative in some way, including not only image data and vehicle information, but also programs and instructions.

[0116] The driving path storage unit 105 stores the vehicle's driving path. The driving path can be represented, for example, as a column of map coordinates on a map. Alternatively, it can be represented as a vector, a straight line, a curve, etc.

[0117] The radio wave image storage unit 106 stores the acquired radio wave images. The radio wave images are obtained through... Figure 1 The radio wave map server device 5 obtains the radio wave map by sending a radio wave map request. Details of the acquisition method will be described later in the section on propagation environment information acquisition unit 109. Alternatively, the radio wave map can also be automatically generated and acquired by using an antenna with a reference signal positioned in front of the vehicle's direction of travel to determine the transmission bit rate.

[0118] In this embodiment, since a radio wave diagram is used when sending data to the information storage server device 3 via the base station device 4, the radio wave diagram used is preferably a radio wave diagram for the uplink.

[0119] The data storage unit 104, the travel path storage unit 105, and the radio wave map storage unit 106 can be implemented using volatile memory such as RAM, in addition to non-volatile memory such as flash memory or hard disk. Alternatively, removable storage media such as BD, DVD, and SD cards can also be used.

[0120] The control unit 107 controls the operation of the wireless communication unit 101, the location information acquisition unit 102, the speed information acquisition unit 103, the data storage unit 104, the driving route storage unit 105, and the radio wave map storage unit 106. Additionally, the control unit 107 implements the operation of the driving route information acquisition unit 108, the propagation environment information acquisition unit 109, the conversion unit 110, the distribution unit 111, the transmission instruction unit 112, and the traffic light information acquisition unit 113.

[0121] The driving route information acquisition unit 108 acquires the vehicle's future driving route. The driving route can also be automatically generated by pre-determining the destination on the navigation device. Alternatively, it can be received from an external driving assistance device. The generated or received driving route is stored in the driving route storage unit 105. Furthermore, the driving route information acquisition unit 108 acquires the driving route by reading the portion of the driving route currently in progress and to be traveled in the future from the driving route storage unit 105. Alternatively, the driving route information acquisition unit 108 acquires the entire driving route to be targeted by pre-retrieving it from the driving route storage unit 105 and storing it in RAM. Alternatively, for example, in the case of an autonomous vehicle, a driving route request can be sent to a server (not shown), from which the driving route can be downloaded and acquired.

[0122] The propagation environment information acquisition unit 109 acquires "propagation environment information" of the radio wave propagation path on the driving path, which is acquired by the driving path information acquisition unit 108. The radio wave propagation path is the radio wave propagation path used in wireless communication between the base station device 4 and the wireless communication unit 101, and is specifically formed on a line connecting the position of the vehicle on the driving path and the position of the base station device 4. The radio wave diagram containing the acquired propagation environment information is stored in the radio wave diagram storage unit 106.

[0123] Here, "propagation environment information" refers to information indicating the state or inference results of the radio wave propagation path. Indicators representing these include, for example, RSSI, RSRP, RSRQ, SNR, SIR, BER, propagation function, propagation path rows and columns, and average bit rate per unit time (bit / s).

[0124] In addition, "acquisition" includes situations where propagation environment information is acquired from external communication devices, read from the storage device of the data transmission device and acquired, and situations where the data transmission device acquires propagation environment information by generating it itself.

[0125] use Figure 3 (a) An explanation of the propagation environment information along the travel path acquired by the propagation environment information acquisition unit 109. Figure 3 In (a), the horizontal axis represents the travel path starting from the current position, and the vertical axis represents the transmission bit rate, which serves as information about the propagation environment. Furthermore, the transmission bit rate varies depending on the location along the travel path. For example, the communication environment is good when the location is close to base station device 4, while the communication environment is poor when there are obstructions such as buildings or mountains, or when the location is far from base station device 4. Therefore, the transmission bit rate also varies depending on the communication environment.

[0126] The propagation environment information acquisition unit 109 obtains the transmission bit rate along the driving path by sending a radio wave map request to the radio wave map server device 5. The radio wave map request includes requested location information, which can be expressed using latitude, longitude, and altitude (WGS-84) or IDs representing grid points on a map. In this embodiment, the requested location information includes multiple location information points along the driving path. The more location information points there are, the more continuously changing the transmission bit rate can be obtained; however, it is preferable to set a number corresponding to the level of positioning accuracy. For example, location information can be transmitted every 10 meters when the positioning accuracy is 1 to 10 meters, every 1 meter when the accuracy is 10 cm to 1 meter, and every 10 cm when the accuracy is less than 10 cm.

[0127] Furthermore, the request via radio wave map only obtains a portion of the radio wave map, specifically the section corresponding to the driving path. However, from the radio wave map... Figure 3 (a) That is based on the mapping of the relationship between propagation environment information and location information. Obtaining radio wave diagrams and obtaining propagation environment information are synonymous.

[0128] In this embodiment, the transmission bit rate is obtained as propagation environment information, but other propagation environment information, such as the receive strength (RSSI) in the base station device 4, could also be used. In this case, as described later, the conversion from receive strength to transmission bit rate can be performed.

[0129] The transmission bit rate, which serves as information about the propagation environment, can also be either a first transmission bit rate (equivalent to "first communication speed") or a second transmission bit rate (equivalent to "second communication speed") that is slower than the first transmission bit rate. These two transmission bit rates can be used separately via the transmission instruction unit 112, which will be described later.

[0130] Furthermore, if the radio wave map corresponding to the travel path has already been saved in the radio wave map storage unit 106, the propagation environment information acquisition unit 109 can also acquire propagation environment information from the radio wave map storage unit 106.

[0131] The traffic light information acquisition unit 113 acquires the remaining time of the stop signal of the traffic light. As described above, the traffic light 6 transmits the signal type and the remaining time until the signal type changes; the traffic light information acquisition unit 113 only needs to acquire the remaining time of the stop signal among the signal types. The traffic light information acquisition unit 113 acquires the remaining time of the stop signal via the wireless communication unit 101 or another communication unit not shown.

[0132] The conversion unit 110, based on the moving speed acquired by the speed information acquisition unit 103, converts the relationship between the travel path and the propagation environment information into data time slots defined by a communication speed per unit time. Hereinafter, using... Figure 3 To explain in detail.

[0133] Figure 3 (a) As already explained, it is a radio waveform showing the relationship of the transmission bit rate along the travel path. The conversion unit 110 uses the vehicle's current speed to... Figure 3 (a) radio wave diagram, as Figure 3 (b) In this way, the horizontal axis is converted from distance to time. That is, the distance to each location on the travel path is converted into the arrival time to each location on the travel path. Moreover, as... Figure 3 (b) In this way, by dividing the data into units of time, it is converted into data time slots defined by the transmission bit rate per unit of time (equivalent to "communication speed"). The unit of time can be any time, for example, it can be set to 1 second.

[0134] By dividing the data into such time slots, the amount of data that can be sent per unit of time can be calculated.

[0135] Since a vehicle moving at zero speed while stationary cannot convert distance to time, the transmission bit rate at the current location is assumed to continue in the future while the vehicle is stationary, and the radio wave diagram is converted into data time slots.

[0136] However, in the case of a stop due to a signal, since it is possible to predict that the vehicle will move in a certain manner in the near future, the conversion unit can convert to a data time slot based on the predicted movement speed. For example, when the vehicle stops according to the stop signal of the traffic light, the conversion unit 110 assumes that the vehicle's movement speed will increase proportionally to the speed limit of the travel path after the remaining time acquired by the traffic light information acquisition unit 113, and performs the conversion accordingly. For example, if the remaining time is 30 seconds and the speed limit of the travel path is 60 km / h, the vehicle is converted to a data time slot with the transmission bit rate at the current position before 30 seconds, and after 30 seconds, it is assumed to change to a speed of 60 km / h with an acceleration of 0.1G and is converted to a data time slot.

[0137] In addition, Figure 3 middle, Figure 3 (a) and Figure 4 (b) The vertical axis is set to the transmission bit rate, so no vertical axis conversion is needed. However, if the propagation environment information acquired by the propagation environment information acquisition unit 109 is different from the transmission bit rate, vertical axis conversion is also needed. For example, if the propagation environment information acquired by the propagation environment information acquisition unit 109 is the receiver strength (RSSI), a table that predefines the relationship between receiver strength and transmission bit rate is used, along with various calculations, to convert it to the transmission bit rate.

[0138] The allocation unit 111 allocates data sequentially, starting from the data time slot with the faster bit rate. This data is stored in the data storage unit 104.

[0139] Here, "allocating data" means allocating all data if it is possible to send all data through a single data time slot, and means allocating a portion of the data if it is not possible to send all data through a single data time slot. In the latter case, data is allocated across multiple data time slots.

[0140] use Figure 4 This section explains the method for allocating data to data time slots.

[0141] exist Figure 4 In (a), the transmission bit rate of each data time slot is fastest at slot a, decreasing in the order of b, c, d, e. Here, we consider the case of transmitting a specified amount of data. When the specified amount of data is allocated sequentially from the fastest bit rate data time slot a, in the order a1, a2, a3, a4, b1, b2, c1, c2, the data is fully contained in the data time slot d1 at the moment it is finally allocated. That is, these data time slots are the data time slots for transmitting data, and the unallocated data time slots d2, d3, d4, e1, e2, and e3 are the data time slots for not transmitting data.

[0142] Next, use Figure 4 (b) Explains the case of sending data with a specified sending deadline. Figure 4 In (b), a time slot designated as a "transmission deadline" is set between b1 and b2 in the transmitted data. Therefore, since the data cannot be sent after b2, it must be transmitted within the data time slot before the time slot following b1. Therefore, in Figure 4 In (b), data is allocated in the data slots prior to the transmission deadline. In this case, data is allocated in the order of a1, a2, a3, a4, b1, c1, c2, d1, d2, d3.

[0143] Here, "sending deadline" simply needs to specify the final time the request should be sent, including both cases where a deadline is specified and cases where a period is specified. Furthermore, the deadline and period can be specified not only by a specific moment or time, but also by other means such as the value of a counter.

[0144] When multiple data items are being sent, they are allocated sequentially, starting with the data whose sending deadline is closest to the current time. Figure 4 In (c), consider the case where data 1 has a transmission deadline of 1, and data 2 has a transmission deadline of 2. Transmission deadline 1 is set to be closer to the current time than transmission deadline 2. Data 1 is allocated in the data time slots prior to transmission deadline 1 in descending order of transmission bit rate. Figure 4 In (c), data is allocated to a1 and a2. Data 2 is allocated in data time slots that are before transmission deadline 2 and for which no data has yet been allocated, in descending order of transmission bit rate. Figure 5 In (c), the values ​​are assigned to a3, a4, b1, and c1.

[0145] The data transmission period can be appropriately set by the application accompanying the data transmission based on the type and size of the data. For example, data used for real-time control may be 10-100ms, big data and sensor detection data from other vehicles may be 1s-1m, and data used for map updates and software updates (OTA) may be 24h, taking into account the data's lifecycle, urgency, and allowable latency.

[0146] In this way, even for data with a delivery deadline, a communication plan can be developed to ensure that the data is sent before the deadline.

[0147] In this embodiment, since the data transmission timing is controlled by time rather than the vehicle's current position, a deviation occurs between the transmission bit rate of the initially converted data time slot and the actual transmission bit rate that can be transmitted when the vehicle's speed changes. Therefore, when the vehicle's speed changes, it is preferable to perform the conversion based on the conversion unit 110 and the allocation based on the allocation unit 111 again.

[0148] Therefore, in this embodiment, conversion based on conversion unit 110 and allocation based on allocation unit 111 are performed when the specified conditions are met.

[0149] As an example of the prescribed conditions, when the moving speed changes by more than a "prescribed value", a conversion based on the conversion unit 110 and an allocation based on the allocation unit 111 are performed. The prescribed value could be, for example, 1 m / s. Alternatively, it could be a value proportional to the speed or a value proportional to the speed gradient.

[0150] In this way, by converting and allocating data under varying speed conditions, the deviation between the propagation environment information of the radio wave diagram and the actual propagation environment of the transmitted data can be reduced.

[0151] Here, "specified value" includes not only a fixed value, but also a value that changes according to specified conditions.

[0152] As another example of the prescribed conditions, conversion based on conversion unit 110 and allocation based on allocation unit 111 are performed per unit time of data time slot. In this embodiment, for example, it may be set to every 1 second. In this case, although it is not linked to changes in movement speed, since the conversion and allocation are performed in a relatively short cycle, it follows changes in movement speed in terms of results.

[0153] In this way, by converting and allocating data per unit time slot, even changes in moving speed can be absorbed, further reducing the deviation between the propagation environment information of the radio wave diagram and the actual propagation environment of the transmitted data.

[0154] When data is allocated in the data time slot corresponding to the current time, the transmission instruction unit 112 instructs the wireless communication unit 101 to transmit the data allocated to the data time slot. For example, in Figure 5 In case (a), since data is allocated in the data time slot c1 at the current time, the wireless communication unit 101 is instructed to transmit the data allocated to the data time slot c1.

[0155] Furthermore, as described above, when two transmission bit rates are obtained—a first transmission bit rate (equivalent to "first communication speed") and a second transmission bit rate (equivalent to "second communication speed") that is slower than the first transmission bit rate—the transmission instruction unit 112 can instruct which transmission bit rate to use based on the type and size of the data. For example, the transmission instruction unit 112 may use the first communication bit rate when the data has a higher "priority," and in other cases, instruct the data to be transmitted using the second transmission bit rate. Furthermore, as examples of the various transmission bit rates, the first transmission bit rate can be set to the desired maximum speed, and the second transmission bit rate can be set to the recommended speed. In this way, by using two or more transmission bit rates separately, multiple transmitting terminals can be accommodated in the base station device 4.

[0156] Here, "priority" simply reflects the value assessment of the data itself, such as its importance and urgency.

[0157] (2) Operation of data transmission device 100

[0158] use Figure 6 The flowchart below explains the operation of the data transmission device 100 in this embodiment.

[0159] Furthermore, the following actions not only refer to the data transmission method executed by the data transmission device 100, but also to the processing of the data transmission program that can be executed by the data transmission device 100.

[0160] Moreover, these treatments are not limited to Figure 1 The order shown. That is, the order can be changed as long as there are no constraints such as the relationship between a step and the result of its predecessor.

[0161] The following operations are illustrated by an example of conversion based on conversion unit 110 and allocation based on allocation unit 111 performed per unit of time.

[0162] The driving path information acquisition unit 108 of the data transmission device 100 acquires the future driving path of the vehicle (S101).

[0163] The propagation environment information acquisition unit 109 acquires the propagation environment information of the radio wave propagation path on the driving path acquired by the driving path information acquisition unit 108 (S102).

[0164] The speed information acquisition unit 103 detects and acquires the vehicle's moving speed (S103).

[0165] Based on the moving speed acquired by the speed information acquisition unit 103, the conversion unit 110 converts the relationship between the travel path and the propagation environment information into a data time slot defined by the communication speed per unit time (S104).

[0166] The allocation unit 111 allocates the data stored in the data storage unit 104 sequentially, starting from the data time slot with the faster communication speed (S105).

[0167] The transmission instruction unit 112 determines whether data is allocated in the data time slot corresponding to the current time (S106). If data is allocated in the data time slot corresponding to the current time (S106: "Yes"), the wireless communication unit 101 is instructed to transmit the data allocated in the data time slot (S107). If no data is allocated in the data time slot corresponding to the current time (S106: "No"), the process proceeds to S108.

[0168] Control unit 107 determines whether a unit of time has elapsed (S108). If a unit of time has elapsed (S108: "Yes"), the process is moved to S103.

[0169] According to the data transmission apparatus 100, data transmission method, and data transmission program of this embodiment, since the radio wave diagram is converted into a data time slot defined by the communication speed per unit time, the transmission of data can be managed by time.

[0170] Furthermore, since data is allocated and transmitted sequentially starting from the faster data time slots, the communication time required can be reduced, thereby enabling efficient data transmission. As a result, the occupancy time of the base station device 4 can be shortened, thereby reducing the burden on the base station device 4, and multiple transmitting terminals can be accommodated by the base station device 4.

[0171] Furthermore, the ability to execute communication plans based solely on the availability of data in the current data time slot reduces the burden on data transmission devices.

[0172] Moreover, by performing conversion and allocation at specified intervals, data can be sent at appropriate times even if the vehicle speed changes.

[0173] 3. Implementation Method 2

[0174] (1) Structure of data transmission device 200

[0175] use Figure 6 The structure of the data transmission device 200 in Embodiment 2 will be described below. Figure 6The information distribution server device 2 is equivalent to the data transmission device 200. Furthermore, since the structure is the same as that of the data transmission device 100 in Embodiment 1, the description is omitted, and the description of Embodiment 1 is appropriately referenced.

[0176] The data transmitting device 200 is a device for transmitting data to the vehicle-mounted device 1 mounted on the "mobile body". Furthermore, the data transmitting device 200 is a device that communicates with the transmitting and receiving devices of the vehicle-mounted device 1 mounted on the mobile body; however, for the sake of simplicity, it may be described as communicating with the vehicle.

[0177] The data transmission device 200 includes a receiving unit 201, a transmitting unit 202, a data storage unit 203, a travel path storage unit 204, a radio wave diagram storage unit 205, and a control unit 206. Furthermore, the control unit 206 implements a travel path information acquisition unit 207, a propagation environment information acquisition unit 208, a conversion unit 209, a distribution unit 210, and a transmission instruction unit 211.

[0178] The data transmission device 200 can be composed of a general-purpose CPU (Central Processing Unit), volatile memory such as RAM, non-volatile memory such as ROM, flash memory, or hard disk, various interfaces, and an internal bus connecting them. Furthermore, it can be configured to perform functions by executing software on this hardware. Figure 1 The functions of each functional module are recorded in the document.

[0179] Of course, the data transmission device 200 can also be implemented using dedicated hardware such as LSI.

[0180] In this embodiment, the data transmission device 200 is assumed to be a finished server device, but it is not limited thereto. For example, it can be a semiconductor circuit or a semiconductor module as a component, an ECU as a semi-finished product, or a personal computer (PC), a smartphone, a mobile phone, or a navigation system as a finished product.

[0181] In addition, the data transmission device 200 can be composed of multiple server devices, in addition to a single server device.

[0182] The receiving unit 201 receives various data from outside the data transmitting device 200. Specifically, the receiving unit 201 communicates with the vehicle, which is a moving body, and receives the vehicle's moving speed obtained by the vehicle speed information acquisition unit 103 and the remaining time of the stop signal obtained by the traffic light information acquisition unit 113.

[0183] exist Figure 7The receiving unit 201 receives data from the vehicle via the base station device 4, which is an external communication device, but not necessarily via the base station device 4.

[0184] The transmitting unit 202 transmits various data to the outside of the data transmitting device 200. Specifically, the transmitting unit 202 transmits data to the base station device 4, which serves as an external communication device for "wireless communication" with the vehicle. The example of the wireless communication method is the same as the example described by the wireless communication unit 101.

[0185] The data storage unit 203 stores the "data" sent from the sending unit 202. The example of the data is the same as the example described by the data storage unit 104.

[0186] The driving path storage unit 204 stores the vehicle's driving path. The example of the driving path is the same as the example described via the driving path storage unit 105. Alternatively, the driving path generated in the vehicle can be received by the receiving unit 201 and stored in the driving path storage unit 204. Alternatively, the driving path received from an external driving assistance device via the receiving unit 201 can also be stored in the driving path storage unit 204. To distinguish the driving paths of multiple vehicles, it is preferable to store them in association with the vehicle ID that identifies the vehicle.

[0187] The radio wave image storage unit 205 stores the acquired radio wave images. The radio wave images are obtained through... Figure 7 The radio wave image server device 5 sends a radio wave image request to obtain it. The details of the acquisition method are the same as those described by the propagation environment information acquisition unit 109. Furthermore, when the information distribution server device 2 also functions as the radio wave image server device 5, it is not necessary to send a radio wave image request to the outside.

[0188] In this embodiment, since a radio wave pattern is used when transmitting data to the vehicle-mounted device 1 via the base station device 4, the radio wave pattern used is preferably a radio wave pattern for the downlink.

[0189] The data storage unit 203, the travel path storage unit 204, and the radio wave map storage unit 205 can be implemented using volatile memory such as RAM, in addition to non-volatile memory such as flash memory or hard disk. Alternatively, removable storage media such as BD, DVD, or SD cards can also be used.

[0190] The control unit 206 controls the operation of the receiving unit 201, the transmitting unit 202, the data storage unit 203, the travel path storage unit 204, and the radio wave pattern storage unit 205. In addition, the control unit 206 implements the travel path information acquisition unit 207, the propagation environment information acquisition unit 208, the conversion unit 209, the distribution unit 210, and the transmission instruction unit 211.

[0191] The driving route information acquisition unit 207 acquires the vehicle's future driving route. Specifically, it acquires the route by reading it from the driving route storage unit 204. The method by which the driving route acquisition unit 207 acquires the driving route is the same as that described by the driving route information acquisition unit 108.

[0192] The propagation environment information acquisition unit 208 acquires "propagation environment information" of the radio wave propagation path on the driving path acquired by the driving path information acquisition unit 207. The method for acquiring the propagation environment information of the propagation environment information acquisition unit 208 and the examples of the propagation environment information are the same as those described by the propagation environment information acquisition unit 109.

[0193] The conversion unit 209 converts the relationship between the travel path and the propagation environment information into a data time slot defined by the communication speed per unit time, based on the vehicle's moving speed received by the receiving unit 201. The conversion method of the conversion unit 209 is the same as that described by the conversion unit 110.

[0194] The allocation unit 210 allocates data stored in the data storage unit 203 sequentially, starting from the data time slot with the faster transmission bit rate. The allocation method of the allocation unit 210 is the same as that described in the allocation unit 111. In addition, the timing of conversion and allocation is also the same as that described in Embodiment 1.

[0195] If data is allocated in the data time slot corresponding to the current time, the transmission instruction unit 211 instructs the transmission unit 202 to transmit the data allocated to the data time slot. The transmission instruction content of the transmission instruction unit 211 is the same as that described by the transmission instruction unit 112.

[0196] (2) Operation of data transmission device 200

[0197] use Figure 8 The flowchart below explains the operation of the data transmission device 200 in this embodiment.

[0198] Furthermore, the following actions not only refer to the data transmission method executed by the data transmission device 200, but also to the processing of the data transmission program that can be executed by the data transmission device 200.

[0199] Moreover, these treatments are not limited to Figure 1 The order shown. That is, the order can be changed as long as there are no constraints such as the relationship between a step and the result of its predecessor.

[0200] The following operations are illustrated by an example of conversion based on conversion unit 209 and allocation based on allocation unit 210 performed per unit of time.

[0201] The driving path information acquisition unit 207 of the data transmission device 200 acquires the future driving path of the vehicle (S201).

[0202] The propagation environment information acquisition unit 208 acquires the propagation environment information of the radio wave propagation path on the driving path acquired by the driving path information acquisition unit 207 (S202).

[0203] The receiving unit 201 receives and acquires the vehicle's moving speed (S203).

[0204] Based on the moving speed received by the receiving unit 201, the conversion unit 209 converts the relationship between the travel path and the propagation environment information into a data time slot defined by the communication speed per unit time (S204).

[0205] The allocation unit 210 allocates the data stored in the data storage unit 203 sequentially, starting from the data time slot with the faster communication speed (S205).

[0206] The transmission instruction unit 211 determines whether data is allocated in the data time slot corresponding to the current time (S206). If data is allocated in the data time slot corresponding to the current time (S206: "Yes"), the transmission unit 202 is instructed to transmit the data allocated to the data time slot (S207). If no data is allocated in the data time slot corresponding to the current time (S206: "No"), the process proceeds to S208.

[0207] Control unit 206 determines whether a unit of time has elapsed (S208). If a unit of time has elapsed (S208: "Yes"), the process is moved to S203.

[0208] According to the data transmission apparatus 200, data transmission method, and data transmission program of this embodiment, since the radio wave diagram is converted into a data time slot defined by the communication speed per unit time, the transmission of data can be managed by time.

[0209] Furthermore, since data is allocated and transmitted sequentially starting from the faster data time slots, the communication time required can be reduced, thereby enabling efficient data transmission. As a result, the occupancy time of the base station device 4 can be shortened, thereby reducing the burden on the base station device 4, and multiple transmitting terminals can be accommodated by the base station device 4.

[0210] Furthermore, the ability to execute communication plans based solely on the availability of data in the current data time slot reduces the burden on data transmission devices.

[0211] Moreover, by performing conversion and allocation at specified intervals, data can be sent at appropriate times even if the vehicle speed changes.

[0212] (3) Modification of the data transmission device 200

[0213] The data transmission device 200 in Embodiment 2 is implemented by the information distribution server device 2, but the data transmission device 200 can also be mounted on a vehicle as a mobile body to transmit data to other vehicles.

[0214] exist ​ In this process, the data transmission device 200 mounted on vehicle A transmits data to vehicle B, which is another vehicle. Specifically, the data is transmitted as follows.

[0215] The receiving unit 201 of the data transmitting device 200 receives the moving speed and travel path of vehicle B. Additionally, the propagation environment information acquisition unit 208 acquires propagation environment information by acquiring the downlink radio wave diagram between vehicle B and base station device 4. Furthermore, the transmitting unit 202, based on the instruction of the transmitting instruction unit 211, transmits data allocated to data time slots via the conversion unit 209 and the allocation unit 210 to base station device 4. Base station device 4 transmits data directly or temporarily via a backbone server to the vehicle-mounted device 1 of vehicle B.

[0216] Furthermore, although the propagation environment information acquisition unit 208 acquires the downlink radio wave pattern between vehicle B and base station device 4, it can also acquire the uplink radio wave pattern between vehicle A and base station device 4. The specific usage of the uplink radio wave pattern is as described in Embodiment 1.

[0217] 4. Other implementation methods

[0218] Embodiments 1 and 2 are examples of data transmitting devices, but they can also be applied to data receiving devices. Regarding the radio wave pattern used at this time, in ​ When the on-board unit 1 is used as a data receiving device, the downlink waveform is obtained; when the information distribution server unit 2 is used as a data receiving device, the uplink waveform is obtained.

[0219] 5. Summary

[0220] The features of the data transmission apparatus in each embodiment of this disclosure have been described above.

[0221] Since the words used in each implementation are illustrative, they can also be replaced with synonymous words or words that contain synonymous functions.

[0222] The block diagram used to describe the implementation is obtained by classifying and arranging the configuration of the device for each function. Individual functional blocks can be implemented by arbitrarily combining hardware and software. Furthermore, since the block diagram illustrates the functions, it can be understood as a disclosure of methods and procedures for implementing those methods.

[0223] It can be understood that the functional blocks of the processes, flows and methods described in the various implementations can be changed in sequence, as long as there are no restrictions such as using the results of previous steps in one step.

[0224] Terms such as first, second to N (where N is an integer) used in each embodiment and claim are used to distinguish two or more configurations and methods of the same kind and are not intended to limit order or superiority.

[0225] Each embodiment is based on a device mounted on a vehicle, but this disclosure also includes dedicated or general-purpose devices other than those for vehicles, except where specifically defined in the claims.

[0226] In each embodiment, the description is based on the premise that the device disclosed in each embodiment is mounted on a vehicle, but it may also be based on the premise that it is held by a pedestrian.

[0227] Furthermore, the following examples can be cited as examples of the manner of the apparatus disclosed herein.

[0228] Examples of components include semiconductor elements, electronic circuits, modules, and microcomputers.

[0229] Examples of semi-finished products include electronic control units (ECUs) and motherboards.

[0230] Examples of finished products include mobile phones, smartphones, tablets, personal computers (PCs), workstations, and servers.

[0231] In addition, it includes devices with communication functions, such as cameras, still cameras, and car navigation systems.

[0232] In addition, necessary functions such as antennas and communication interfaces can be added to each device.

[0233] It is assumed that the data transmission apparatus of this disclosure is used to provide various services. Along with the provision of these services, the apparatus of this disclosure, the methods of this disclosure, and / or the procedures of this disclosure are used.

[0234] Furthermore, this disclosure can be implemented not only by dedicated hardware having the structure and functions described in each embodiment, but also by a combination of a program and hardware, wherein the program is a program for implementing this disclosure recorded on a recording medium such as a memory or hard disk, and the hardware is general-purpose hardware having a dedicated or general-purpose CPU and memory capable of executing the program.

[0235] Programs stored on non-portable physical recording media of dedicated or general-purpose hardware (e.g., external storage devices (hard disks, USB drives, CD / BDs, etc.) or internal storage devices (RAM, ROM, etc.)) can also be provided to the dedicated or general-purpose hardware via the recording media, or from the server via a communication line without using the recording media. This allows for the continuous provision of the latest functionality through program upgrades.

[0236] The data transmission device disclosed herein is primarily described as a device for use in automobiles, but it can of course be applied to two-wheeled motorcycles, motorized bicycles, railways, and all moving bodies such as pedestrians, ships, and airplanes.

[0237] In addition, it can be applied to devices such as mobile phones, tablets, and game consoles for various purposes.

Claims

1. A data transmission device that is a data transmission device mounted on a mobile body, comprising: a wireless communication section that performs wireless communication with an external communication device; a data storage section that stores data transmitted from the wireless communication section; a travel path information acquisition section that acquires a future travel path of the mobile body; a propagation environment information acquisition section that acquires propagation environment information of a wave propagation path used in the wireless communication on the travel path; a speed information acquisition section that acquires a moving speed of the mobile body; a conversion section that converts a relationship between the travel path and the propagation environment information into data slots defined by communication speed per unit time, based on the moving speed; an allocation section that allocates the data in order from the data slots in which the communication speed is faster; and a transmission instruction section that instructs the wireless communication section to transmit the data allocated to the data slots, in a case where the data is allocated in the data slots corresponding to a current time, the data transmission device further comprising a signal light information acquisition section that acquires a remaining time of a stop signal of a signal light, in a case where the mobile body stops in accordance with the stop signal of the signal light, the conversion section performs conversion, taking into account that the moving speed of the mobile body increases by a certain ratio to a limit speed of the travel path after the remaining time elapses.

2. The data transmission device according to claim 1, wherein the conversion section and the allocation section perform conversion and allocation per unit time.

3. The data transmission device according to claim 1, wherein the conversion section and the allocation section perform conversion and allocation in a case where the moving speed changes by a prescribed value or more.

4. The data transmission device according to claim 1, wherein a transmission deadline is set in the data, the allocation section allocates the data in the data slots before the transmission deadline.

5. The data transmission device according to claim 4, wherein in a case where the data is plural, the allocation section allocates the data in the data slots in order from the data whose transmission deadline is close to a current time.

6. The data transmission device according to claim 1, wherein the propagation environment information includes a first communication speed and a second communication speed that is slower than the first communication speed, the transmission instruction section instructs transmission of the data at the first communication speed in a case where the priority of the data is high, and instructs transmission of the data at the second communication speed in other cases.

7. A data transmission device that transmits data to a mobile body, comprising: a transmission section that transmits the data to an external communication device that performs wireless communication with the mobile body; a data storage section that stores the data transmitted from the transmission section; a travel path information acquisition section that acquires a future travel path of the mobile body; a propagation environment information acquisition section that acquires propagation environment information of a wave propagation path used in the wireless communication on the travel path; a reception section that receives a moving speed of the mobile body; ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ a conversion section that converts a relationship between the travel route and the propagation environment information into data slots defined by a communication speed per unit time, based on the moving speed; an allocation section that allocates the data in order from the data slot in which the communication speed is faster; a transmission instruction section that instructs the transmission section to transmit the data allocated to the data slot, in a case where the data is allocated to the data slot corresponding to the current time point, furthermore, the remaining time until a stop signal of a traffic light is received by the reception section, in a case where the mobile body stops in accordance with the stop signal of the traffic light, the conversion section performs the conversion assuming that the moving speed of the mobile body increases by a certain ratio to the limit speed of the travel route after the remaining time elapses.

8. The data transmission device according to claim 7, wherein the conversion section and the allocation section perform the conversion and the allocation per the unit time.

9. The data transmission device according to claim 7, wherein the conversion section and the allocation section perform the conversion and the allocation in a case where the moving speed is equal to or higher than a predetermined value.

10. The data transmission device according to claim 7, wherein a transmission deadline is set in the data, the allocation section allocates the data in the data slot before the transmission deadline.

11. The data transmission device according to claim 10, wherein in a case where the data is plural, the allocation section allocates the data in the data slot in order from the data whose transmission deadline is close to the current time point.

12. The data transmission device according to claim 7, wherein the propagation environment information includes a first communication speed and a second communication speed slower than the first communication speed, the transmission instruction section instructs the transmission of the data at the first communication speed in a case where the priority of the data is high, and instructs the transmission of the data at the second communication speed in other cases.

13. A data transmission method, which is a data transmission method performed by a data transmission device mounted on a mobile body and having a wireless communication section that performs wireless communication with an external communication device, wherein a future travel route of the mobile body is acquired, propagation environment information of a wave propagation path on the travel route used in the wireless communication is acquired, a moving speed of the mobile body is acquired, a relationship between the travel route and the propagation environment information is converted into data slots defined by a communication speed per unit time, based on the moving speed, the data is allocated in order from the data slot in which the communication speed is faster, in a case where the data is allocated to the data slot corresponding to the current time point, the transmission of the data allocated to the data slot is instructed to the wireless communication section, furthermore, the remaining time until a stop signal of a traffic light is acquired, in a case where the mobile body stops in accordance with the stop signal of the traffic light, the conversion is performed assuming that the moving speed of the mobile body increases by a certain ratio to the limit speed of the travel route after the remaining time elapses. In a case where the mobile body stops in accordance with the stop signal of the signal light, a conversion is performed as if the moving speed of the mobile body increases at a certain ratio to the limit speed of the travel path after the lapse of the remaining time.

14. A data transmission method, which is a data transmission method executable by a data transmission device having a transmission section that transmits data to an external communication device that performs wireless communication with a mobile body, wherein a future travel path of the mobile body is acquired, propagation environment information of a wave propagation path used in the wireless communication on the travel path is acquired, a moving speed of the mobile body is received, a relationship between the travel path and the propagation environment information is converted into data slots defined by communication speeds per unit time based on the moving speed, the data is allocated in order from the data slot with the faster communication speed, in a case where the data is allocated in the data slot corresponding to the current time, the transmission section is instructed to transmit the data allocated to the data slot, a remaining time of a stop signal of a signal light is further received, in a case where the mobile body stops in accordance with the stop signal of the signal light, a conversion is performed as if the moving speed of the mobile body increases at a certain ratio to the limit speed of the travel path after the lapse of the remaining time.

15. A storage medium storing a data transmission program, which is a data transmission program executable by a data transmission device mounted on a mobile body and having a wireless communication section that performs wireless communication with an external communication device, wherein a future travel path of the mobile body is acquired, propagation environment information of a wave propagation path used in the wireless communication on the travel path is acquired, a moving speed of the mobile body is acquired, a relationship between the travel path and the propagation environment information is converted into data slots defined by communication speeds per unit time based on the moving speed, the data is allocated in order from the data slot with the faster communication speed, in a case where the data is allocated in the data slot corresponding to the current time, the wireless communication section is instructed to transmit the data allocated to the data slot, a remaining time of a stop signal of a signal light is further acquired, in a case where the mobile body stops in accordance with the stop signal of the signal light, a conversion is performed as if the moving speed of the mobile body increases at a certain ratio to the limit speed of the travel path after the lapse of the remaining time.

16. A storage medium storing a data transmission program, which is a data transmission program executable by a data transmission device having a transmission section that transmits data to an external communication device that performs wireless communication with a mobile body, wherein a future travel path of the mobile body is acquired, propagation environment information of a wave propagation path used in the wireless communication on the travel path is acquired, a moving speed of the mobile body is received, a relationship between the travel path and the propagation environment information is converted into data slots defined by communication speeds per unit time based on the moving speed, based on the above-described moving speed, the relationship between the above-described travel path and the above-described propagation environment information is converted into data slots defined by a communication speed per unit time, the above-described data is sequentially allocated from the above-described data slots in which the above-described communication speed is fast, in a case where the above-described data is allocated in the above-described data slot corresponding to the current time, the above-described transmission unit is instructed to transmit the above-described data allocated to the above-described data slot, further receiving a remaining time of a stop signal of a traffic light, in a case where the above-described mobile body stops in accordance with the above-described stop signal of the above-described traffic light, it is considered that the moving speed of the above-described mobile body is increased by a certain ratio to the limit speed of the above-described travel path after the above-described remaining time elapses and the conversion is performed.

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