Radio base station, mobile station, vehicle, and message transmission method

Abstract

To reduce a railroad crossing accident.SOLUTION: A roadside machine 20a provided at a periphery of a railroad crossing road 150 where a railroad 120 and a road 110 intersect transmits a message including at least one information element indicating a traffic situation of the road 110 at an outlet side of the railroad crossing road 150 to a vehicle 10a passing through the road 110 toward an entrance side of the railroad crossing road 150 by wireless communication.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a radio base station, a mobile station, a vehicle, and a message transmission method. [Background technology]

[0002] Conventionally, in an intelligent transport system (e.g., ITS: Intelligent Transport System), a technology has been proposed for wireless communication between a roadside unit, which is a base station installed around a road, and an in-vehicle unit, which is a mobile station installed in a vehicle (see, for example, Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Association of Radio Industries and Businesses, "700MHz Band Intelligent Transport Systems ARIB-STD T109 Version 1.3", [online], July 27, 2017, [Retrieved June 22, 2018], Internet http: / / www.arib.or.jp / tyosakenkyu / kikaku_tushin / tsushin_kikaku_number.html Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional ITS is designed to reduce traffic accidents by targeting vehicles such as automobiles traveling on roads, and does not fully consider rail vehicles traveling on railways.

[0005] For this reason, conventional ITS has room for improvement in reducing level crossing accidents at railway crossings where railways and roads intersect, particularly those that occur when vehicles become stranded at the crossing as a result of misjudging traffic congestion ahead (so-called congestion ahead).

[0006] Therefore, an object of the present invention is to provide a base station, a mobile station, a vehicle, and a message transmission method that can reduce railroad crossing accidents. [Means for solving the problem]

[0007] A base station according to a first aspect is installed near a railroad crossing where a railroad and a road intersect. The base station includes a transmitter that transmits a message via wireless communication to a vehicle traveling on the road toward the entrance side of the railroad crossing. The transmitter transmits the message to the vehicle, the message including at least one information element indicating the traffic conditions on the road at the exit side of the railroad crossing.

[0008] A mobile station according to a second aspect is provided in a vehicle. The mobile station includes a receiver that receives a message via wireless communication from a base station provided near a railroad crossing when the vehicle travels along the road toward the entrance of the railroad crossing. The receiver receives the message from the base station, the message including at least one information element indicating the traffic conditions of the road at the exit of the railroad crossing.

[0009] A vehicle according to a third aspect includes the mobile station according to the second aspect.

[0010] A fourth aspect of the message transmission method is a message transmission method in which a base station installed near a railroad crossing where a railroad and a road intersect transmits a message to a vehicle via wireless communication, and includes a step of transmitting a message including information elements indicating the traffic conditions of the road at the exit side of the railroad crossing to a vehicle traveling on the road toward the entrance side of the railroad crossing. [Effects of the Invention]

[0011] According to one aspect of the present invention, it is possible to provide a base station, a mobile station, a vehicle, and a message transmission method that can reduce railroad crossing accidents. [Brief explanation of the drawings]

[0012] [Figure 1]FIG. 1 is a diagram showing a configuration of a transportation communication system according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating the configuration of a roadside device according to an embodiment. [Figure 3] 3A to 3C are diagrams showing the structure of a message for a vehicle according to one embodiment. [Figure 4] FIG. 4 is a diagram showing the configuration of a vehicle according to one embodiment. [Figure 5] FIG. 5 is a diagram illustrating an example of an operation sequence of the transportation communication system according to an embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0013] The embodiments will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

[0014] (Transportation Communication System) First, a transport communication system according to an embodiment will be described. Fig. 1 is a diagram showing the configuration of a transport communication system according to an embodiment.

[0015] As shown in Fig. 1, a transportation communication system according to one embodiment includes vehicles 10a to 10d and roadside units 20a and 20b. Hereinafter, when there is no need to distinguish between the vehicles 10a to 10d, they will be simply referred to as vehicle 10, and when there is no need to distinguish between the roadside units 20a and 20b, they will be simply referred to as roadside unit 20. The roadside unit 20 is an example of a base station.

[0016] Vehicle 10 travels on road 110. In Fig. 1, a four-wheeled motor vehicle is illustrated as vehicle 10, but vehicle 10 may also be a motorcycle, a three-wheeled motor vehicle, an electric bicycle, or the like. Furthermore, although road 110 is illustrated as having one lane, road 110 may also have multiple lanes.

[0017] The roadside unit 20a is installed near a railroad crossing 150 where a road 110 and a railway 120 intersect. Railroad vehicles (not shown) travel on the railway 120. While FIG. 1 illustrates the railway 120 as consisting of one track, the railway 120 may have multiple tracks.

[0018] The railroad crossing 150 is equipped with railroad crossing safety equipment. FIG. 1 shows an example in which the railroad crossing safety equipment includes a railroad crossing warning device 130 (130a and 130b) and railroad crossing gates 140 (140a and 140b). The railroad crossing warning device 130 is a device that notifies vehicle drivers traveling on the road 110 of the presence of the railroad crossing 150 and issues a sound and light warning to stop road traffic when a railroad vehicle approaches. The railroad crossing gate 140 is a device that restricts traffic on the road 110 to give priority to railroad vehicles. The railroad crossing gate 140 has a barrier and a mechanism that raises and lowers it.

[0019] A sensor 160 is provided around the railroad crossing 150. The sensor 160 detects the traffic conditions on the road 110 on the exit side of the railroad crossing 150 and outputs the detection result to the roadside device 20a. The sensor 160 may be any sensor that can detect traffic conditions, such as an ultrasonic sensor, an optical sensor, or an image sensor. The exit side of the railroad crossing 150 refers to the rear side of the railroad crossing 150 in the direction of vehicle traffic on the lane, and the entrance side of the railroad crossing 150 refers to the front side of the railroad crossing 150 in the direction of vehicle traffic on the lane.

[0020] A traffic signal 170 is provided on the road 110 at the exit side of the railroad crossing 150 at a distance from the railroad crossing 150. The traffic signal 170 is a device that displays signals such as permission to proceed and a stop instruction to ensure traffic safety and smooth traffic flow on the road 110. Figure 1 shows an example in which the traffic signal 170 displays a light color indicating a stop instruction, causing vehicles 10b to 10d to stop.

[0021] The roadside device 20b is installed near the traffic signal 170. The roadside device 20b acquires signal light color information indicating the signal light color of the traffic signal 170. The signal light color information may include not only information indicating the current signal light color, but also information indicating a transition pattern of the signal light color over a certain period of time in the future. The roadside device 20b transmits the signal light color information to the roadside device 20a via wireless communication.

[0022] The roadside device 20a transmits a message via wireless communication to the vehicle 10a traveling on the road 110 toward the entrance side of the railroad crossing 150. Specifically, the roadside device 20a transmits a message including at least one information element indicating the traffic conditions on the road 110 at the exit side of the railroad crossing 150 to the vehicle 10a. For example, the at least one information element indicating the traffic conditions on the road 110 at the exit side of the railroad crossing 150 is based on signal light color information that the roadside device 20a receives from the roadside device 20b and detection information that the roadside device 20a acquires from the sensor 160.

[0023] Vehicle 10a receives a message from roadside device 20a. Based on the message received from roadside device 20a, vehicle 10a presents the driver of vehicle 10a with the traffic conditions on road 110 on the exit side of railroad crossing 150. If vehicle 10a is an autonomous vehicle, vehicle 10a may automatically control the proceeding or stopping of vehicle 10a onto railroad crossing 150, taking into account the traffic conditions on road 110 on the exit side of railroad crossing 150, based on the message received from roadside device 20a.

[0024] In this way, by transmitting a message including at least one information element indicating the traffic conditions of road 110 on the exit side of railroad crossing 150 to vehicle 10a traveling on road 110 toward the entrance side of railroad crossing 150, it is possible to reduce railroad crossing accidents at railroad crossing 150. In particular, it is possible to reduce railroad crossing accidents that occur when vehicle 10a becomes stuck at railroad crossing 150 as a result of the driver of vehicle 10a misjudging the congestion ahead of the crossing (so-called congestion ahead).

[0025] (roadside unit) Next, a roadside device 20a according to an embodiment will be described. Fig. 2 is a diagram showing the configuration of the roadside device 20a according to an embodiment.

[0026] 2, the roadside device 20a has an antenna 21a, a wireless communication unit 21, a control unit 22, and an interface 23. The interface 23 is an interface for communicating with a sensor 160. The roadside device 20a may further have an interface for communicating with a railroad crossing warning device 130 and a railroad crossing barrier 140. The roadside device 20a may further have an interface for communicating with a sensor for detecting the approach of a railroad vehicle. The roadside device 20a may also have a GNSS (Global Navigation Satellite System) receiver.

[0027] The wireless communication unit 21 performs wireless communication via an antenna 21a. The antenna 21a may be an omnidirectional antenna or a directional antenna having directivity toward the entrance side of the railroad crossing 150. The antenna 21a may be an adaptive array antenna whose directivity can be dynamically changed.

[0028] The wireless communication method of the wireless communication unit 21 may be a method conforming to ARIB T109, a method conforming to the V2X (Vehicle to Everything) standard of 3GPP (registered trademark; the same applies hereinafter), or a method conforming to a wireless LAN standard such as the IEEE802.11 series. The wireless communication unit 21 may be configured to be compatible with all of these communication standards.

[0029] The wireless communication unit 21 has a receiving unit 21b that converts a wireless signal received by the antenna 21a into a baseband signal (received packet) and outputs it to the control unit 22. The wireless communication unit 21 also has a transmitting unit 21c that converts a baseband signal (transmitted packet) output by the control unit 22 into a wireless signal and transmits it from the antenna 21a.

[0030] If the wireless communication unit 21 complies with the ARIB T109 standard, it may have a function of performing carrier sensing using the receiving unit 21b to determine whether a radio wave frequency (for example, the 700 MHz band) is available. The transmitting unit 21c of the wireless communication unit 21 may transmit packets at a timing determined according to the result of the carrier sensing. One or more packets may constitute one message.

[0031] For example, the wireless communication unit 21 performs road-to-road communication with another roadside unit 20b. The road-to-road communication may be performed by unicast, broadcast, or multicast. The receiving unit 21b of the wireless communication unit 21 receives an road-to-road communication packet from the roadside unit 20b. The road-to-road communication packet may include identification information used to identify the sender. The receiving unit 21b receives a message made up of one or more packets from the roadside unit 20b. The message includes the signal light color information described above.

[0032] The wireless communication unit 21 performs road-to-vehicle communication with the vehicle 10. The road-to-vehicle communication may be performed by unicast, broadcast, or multicast. The road-to-vehicle communication packet transmitted to the vehicle 10 may include identification information used to identify the sender, synchronization information indicating a synchronization method for the roadside device 20a, the transmission time of the packet, and period information indicating the period of the road-to-vehicle communication (for example, the number of transfers in the road-to-vehicle communication, the period length of the road-to-vehicle communication), etc.

[0033] The transmitter 21c of the wireless communication unit 21 transmits a message made up of one or more packets to the vehicle 10 by road-to-vehicle communication. This message is generated by the control unit 22.

[0034] The control unit 22 is configured by a control circuit having at least one memory and at least one processor electrically connected to the memory. The control unit 22 controls various functions of the roadside unit 20a. The control unit 22 periodically generates messages for the vehicle 10 and periodically transmits the messages via the transmission unit 21c.

[0035] 3 is a diagram showing the configuration of a message M for the vehicle 10 according to one embodiment. The message M may be a message transmitted and received at layer 2 or layer 3 of the OSI reference model, or may be a message transmitted and received at the application layer.

[0036] As shown in FIG. 3(A), the message M includes information elements E1 to E5.

[0037] The information element E1 is railroad crossing presence information indicating that a railroad crossing 150 exists on the road 110. The information element E1 may be a flag that is set to "1" if the railroad crossing 150 exists, and to "0" if the railroad crossing 150 does not exist.

[0038] Information element E2 is railroad crossing geographic information that indicates the geographic attributes of railroad crossing 150. Information element E2 includes information that indicates the geographic location (latitude and longitude) of railroad crossing 150. Information element E2 may also include information that indicates the size of railroad crossing 150, for example, the distance between the entrance and exit. The information that indicates the distance between the entrance and exit of railroad crossing 150 may be a numerical value that indicates this distance (for example, how many meters), or may be information that indicates whether railway 120 is single-track or double-track.

[0039] Information element E3 is railroad vehicle approach information that indicates whether or not the approach of a railroad vehicle to the railroad crossing 150 has been detected. Information element E3 may be a flag that is set to "1" if the approach of a railroad vehicle has been detected, and to "0" if the approach of a railroad vehicle has not been detected. Information element E3 may indicate whether or not the railroad crossing warning device 130 is performing an alarm operation, or may indicate whether or not the railroad crossing barrier 140 is performing a blocking operation.

[0040] Information element E4 is at least one information element (traffic information at the railroad crossing destination) that indicates the traffic conditions of the road 110 on the exit side of the railroad crossing 150. Fig. 3(B) shows a first configuration example of information element E4. Fig. 3(C) shows a second configuration example of information element E4.

[0041] 3(B), information element E4 includes information element E41 (leading vehicle position information) indicating the latitude and longitude of leading vehicle 10b on road 110 on the exit side of railroad crossing 150, and information element E42 (leading vehicle speed information) indicating the moving speed of leading vehicle 10b. Leading vehicle 10b refers to the vehicle 10 closest to railroad crossing 150 on the exit side of railroad crossing 150, i.e., the vehicle 10 that has most recently passed through railroad crossing 150.

[0042] Information element E41 may be information indicating whether or not leading vehicle 10b is present at the exit side of railroad crossing 150. Information element E42 may be a numerical value indicating the moving speed of leading vehicle 10b (e.g., kilometers per hour), or may be a flag indicating whether leading vehicle 10b is in a stopped state. A stopped state refers to a state in which the moving speed is less than a threshold, for example, a state in which the moving speed is zero.

[0043] 3(C), information element E4 includes information element E44 (preceding vehicle stop information) that indicates whether there is a preceding vehicle 10b that is stopped on the road 110 on the exit side of the railroad crossing 150. Information element E44 may be a flag that is set to "1" if there is a preceding vehicle 10b that is stopped on the road 110 on the exit side of the railroad crossing 150, and is set to "0" if there is not.

[0044] The control unit 22 may generate the information elements E41, E42, and E44 based on the detection results obtained by the sensor 160. Alternatively, the control unit 22 may generate the information elements E41, E42, and E44 based on a message that the receiving unit 21b receives from the leading vehicle 10b via road-to-vehicle communication. This message includes location information indicating the geographical position of the leading vehicle 10b and speed information indicating the traveling speed of the leading vehicle 10b.

[0045] When a traffic light 170 is provided on the road 110 at the exit side of the railroad crossing 150 at a distance from the railroad crossing 150, the information element E4 includes an information element E43 (railroad crossing signal information) that indicates the signal light color of the traffic light 170. The information element E43 may include not only information indicating the current signal light color, but also information indicating the signal light color transition pattern for a certain period of time in the future.

[0046] The control unit 22 may generate the information element E43 based on signal light color information received by the receiving unit 21b from another roadside device 20b through road-to-road communication. Alternatively, the control unit 22 may generate the information element E43 based on signal light color information acquired via a communication line from a traffic control center (not shown).

[0047] If the road 110 has multiple lanes for travel in both directions, the message M may include an information element E5 (target lane information) for identifying the lane targeted by the information element E4. The information element E5 may be an identifier of the lane targeted by the information element E4, or may be information indicating the vehicle travel direction (bearing) of the lane targeted by the information element E4.

[0048] (vehicle) Next, a vehicle 10a according to one embodiment will be described. Fig. 4 is a diagram showing the configuration of the vehicle 10a according to one embodiment.

[0049] 4, the vehicle 10a includes a GNSS receiver 12, a display unit 13, a drive control unit 14, and an on-board device 16. The on-board device 16 is an example of a mobile station provided in the vehicle 10a. The on-board device 16 includes an antenna 11a, a wireless communication unit 11, and a control unit 15.

[0050] The wireless communication unit 11 performs wireless communication via an antenna 11a. The antenna 11a may be an omnidirectional antenna or a directional antenna having directionality.

[0051] The wireless communication method of the wireless communication unit 11 may be a method conforming to ARIB T109, a method conforming to the 3GPP V2X standard, or a method conforming to a wireless LAN standard such as the IEEE802.11 series, etc. The wireless communication unit 11 may be configured to be compatible with all of these communication standards.

[0052] The wireless communication unit 11 has a receiving unit 11b that converts a wireless signal received by the antenna 11a into a baseband signal (received packet) and outputs it to the control unit 15. The wireless communication unit 11 also has a transmitting unit 11c that converts a baseband signal (transmitted packet) output by the control unit 15 into a wireless signal and transmits it from the antenna 11a.

[0053] If the wireless communication unit 11 complies with the ARIB T109 standard, it may have a function of performing carrier sensing using the receiver 11b to determine whether a radio wave frequency (for example, the 700 MHz band) is available. The transmitter 11c of the wireless communication unit 11 may transmit packets at a timing determined according to the result of the carrier sensing. One or more packets may constitute one message.

[0054] The wireless communication unit 11 performs road-to-vehicle communication with the roadside device 20a. The road-to-vehicle communication may be performed by unicast or broadcast. The receiving unit 11b of the wireless communication unit 11 receives a message M from the roadside device 20a.

[0055] The GNSS receiver 12 performs positioning based on GNSS satellite signals, and outputs to the control unit 15 position information indicating the current geographical position (latitude and longitude) of the vehicle 10a.

[0056] The presentation unit 13 presents information to the driver of the vehicle 10a under the control of the control unit 15. For example, the presentation unit 13 includes at least one of a display that displays information and a speaker that outputs information by voice. Hereinafter, presentation of information refers to at least one of displaying information and outputting information by voice.

[0057] The drive control unit 14 controls an engine or a motor as a power source, a power transmission mechanism, a brake, etc. If the vehicle 10a is an autonomous vehicle, the drive control unit 14 may cooperate with the control unit 15 to control the drive of the vehicle 10a.

[0058] The control unit 15 is configured by a control circuit having at least one memory and at least one processor electrically connected to the memory. The control unit 15 controls various functions in the vehicle 10a (on-vehicle device 16).

[0059] For example, the control unit 15 controls the presentation unit 13 based on a message M received by the reception unit 11b from the roadside device 20a.

[0060] The control unit 15 may control the presentation unit 13 based on the information element E1 (railroad crossing presence information) included in the message M to present information that there is a railroad crossing 150 in the traveling direction of the vehicle 10a.

[0061] The control unit 15 may control the presentation unit 13 to present information indicating the geographical attributes of the railroad crossing 150, based on the information element E2 (railroad crossing geographic information) included in the message M. Here, the control unit 15 may control the presentation unit 13 to present information indicating the distance between the current position of the vehicle 10a and the position of the railroad crossing 150.

[0062] The control unit 15 may control the presentation unit 13 to present information indicating whether or not a railway vehicle is detected approaching the railroad crossing 150, based on information element E3 (railroad vehicle approach information) included in the message M.

[0063] The control unit 15 may control the presentation unit 13 to present information indicating the traffic conditions on the road 110 on the exit side of the railroad crossing 150, based on the information element E4 (traffic information ahead of the railroad crossing) included in the message M.

[0064] For example, when the control unit 15 determines based on the information element E41 (leading vehicle position information), the information element E42 (leading vehicle speed information), or the information element E44 (leading vehicle stop information) that there is a stopped leading vehicle 10b on the road 110 on the exit side of the railroad crossing 150, the control unit 15 controls the presentation unit 13 to present information to that effect. Here, the control unit 15 may alert the driver by presenting information such as "Watch out for entering the railroad crossing" or "Congested ahead of the railroad crossing. Watch out for entering."

[0065] When the control unit 15 determines, based on the information element E43 (railroad crossing signal information), that the traffic signal 170 at the exit side of the railroad crossing 150 is displaying a signal indicating a stop instruction, the control unit 15 controls the presentation unit 13 to present information to that effect. Here, the control unit 15 may alert the driver by presenting information such as "Red light ahead of railroad crossing. Be careful entering."

[0066] When the road 110 has multiple lanes for travel in both directions, the control unit 15 may determine whether to present information based on the information element E4, based on the information element E5 (target lane information) included in the message M. Specifically, the control unit 15 presents information based on the information element E4 only when the lane in which the vehicle 10a is traveling matches the lane indicated by the information element E5.

[0067] When the vehicle 10a is an autonomous vehicle, the control unit 15 may control the driving of the vehicle 10a based on the message M received by the receiving unit 11b from the roadside device 20a.

[0068] The control unit 15 may control the vehicle 10a to slow down as the vehicle 10a approaches the railroad crossing 150 and to stop temporarily just before the railroad crossing 150 based on the information element E1 (railroad crossing existence information) and information element E2 (railroad crossing geographic information) contained in the message M.

[0069] In addition, if the control unit 15 determines that an approach of a railway vehicle to the railroad crossing 150 has been detected based on information element E3 (railroad vehicle approach information) included in message M, it may control the vehicle 10a to continue in a stopped state until the railway vehicle passes through the railroad crossing 150.

[0070] The control unit 15 may control the entry of the vehicle 10a into the railroad crossing 150 based on the information element E4 (traffic information ahead of the railroad crossing) included in the message M, taking into consideration the traffic conditions on the road 110 on the exit side of the railroad crossing 150.

[0071] For example, if the control unit 15 determines, based on information element E41 (preceding vehicle position information), information element E42 (preceding vehicle speed information), or information element E44 (preceding vehicle stop information), that there is a preceding vehicle 10b that is stopped on the road 110 on the exit side of the railroad crossing 150, the control unit 15 may control the vehicle 10a to continue in a stopped state until the preceding vehicle 10b resumes movement or until the preceding vehicle 10b moves a predetermined distance away from the railroad crossing 150.

[0072] If the control unit 15 determines, based on information element E43 (railroad crossing destination signal information), that the traffic light 170 at the exit side of the railroad crossing 150 is displaying a signal indicating a stop, it may control the vehicle 10a to continue in a stopped state until the traffic light 170 switches to a signal indicating permission to proceed.

[0073] When the road 110 has multiple lanes for travel in both directions, the control unit 15 may determine whether to present information based on the information element E4, based on the information element E5 (target lane information) included in the message M. Specifically, the control unit 15 performs drive control of the vehicle 10a based on the information element E4 only when the lane in which the vehicle 10a is traveling matches the lane indicated by the information element E5.

[0074] (Example of operation sequence) 5 is a diagram illustrating an example of an operation sequence of a transportation communication system according to an embodiment. The sequence illustrated in FIG. 5 may be executed periodically.

[0075] As shown in FIG. 5, in step S1, the receiving unit 21b of the roadside device 20a receives signal light color information from the roadside device 20b through road-to-road communication.

[0076] In step S2, the control unit 22 of the roadside device 20a acquires the detection information from the sensor 160 via the interface 23. Note that the order of steps S1 and S2 may be reversed.

[0077] In step S3, the control unit 22 of the roadside device 20a generates a message M.

[0078] In step S4, the transmitter 21c of the roadside device 20a transmits the generated message M to the vehicle 10a by road-to-vehicle communication. The receiver 11b of the vehicle 10a receives the message M from the roadside device 20a.

[0079] In step S5, the control unit 15 of the vehicle 10a presents information based on the received message M or controls the driving of the vehicle 10a.

[0080] (Other embodiments) In the above-described embodiment, an example was described in which information element E4 (traffic information ahead of the railroad crossing) indicating the traffic conditions on the road 110 at the exit side of the railroad crossing 150 individually includes an information element regarding the preceding vehicle 10b and an information element regarding the traffic light 170.

[0081] Here, the information element regarding the preceding vehicle 10b indicates the current stopped state of the preceding vehicle 10b at the exit side of the railroad crossing 150, and the information element regarding the traffic light 170 can be considered to indicate the congestion situation in the near future at the exit side of the railroad crossing 150.

[0082] However, the roadside unit 20a may take into consideration the conditions of both the preceding vehicle 10b and the traffic signal 170 to determine whether or not to permit the vehicle 10a to enter the railroad crossing 150, and may transmit to the vehicle 10a one information element indicating whether or not the vehicle 10a is permitted to enter the railroad crossing 150 as information element E4 (railroad crossing destination traffic information).

[0083] For example, if the roadside unit 20a determines that the preceding vehicle 10b is stopped at the exit side of the railroad crossing 150 or that there will be congestion on the exit side of the railroad crossing 150 in the near future, it transmits to the vehicle 10a an information element E4 (traffic information ahead of the railroad crossing) indicating that entry into the railroad crossing 150 is prohibited.

[0084] A program for causing a computer to execute each process performed by the vehicle 10 (on-board device 16) and a program for causing a computer to execute each process performed by the roadside device 20 may be provided. The program may be recorded on a computer-readable medium. Using the computer-readable medium, it is possible to install the program on a computer. Here, the computer-readable medium on which the program is recorded may be a non-transitory recording medium. The non-transitory recording medium is not particularly limited, and may be, for example, a recording medium such as a CD-ROM or a DVD-ROM.

[0085] The circuits that execute the processes performed by the vehicle 10 (on-board device 16) may be integrated, and at least a part of the vehicle 10 (on-board device 16) may be configured as a semiconductor integrated circuit (chip set, SoC). Also, the circuits that execute the processes performed by the roadside device 20 may be integrated, and the roadside device 20 may be configured as a semiconductor integrated circuit (chip set, SoC).

[0086] The above describes one embodiment in detail with reference to the drawings, but the specific configuration is not limited to that described above, and various design changes can be made within the scope that does not deviate from the gist of the invention. [Explanation of symbols]

[0087] 10: Vehicle 11: Wireless communication unit 11a: Antenna 11b: Receiving unit 11c: Transmitter 12: GNSS receiver 13: Presentation section 14: Drive control unit 15: Control section 16: In-vehicle device 20: Roadside machine 21: Wireless communication unit 21a: Antenna 21b: Receiving unit 21c: Transmitter 22: Control section 23: Interface 110: Road 120: Railway 130: Railroad crossing alarm 140: Railroad crossing gate 150: Railroad crossing 160: Sensor 170:Traffic signal

Claims

1. A radio base station installed near a railroad crossing where a railroad and a road intersect, a transmitter that transmits a message by wireless communication to vehicles traveling on the road toward the entrance side of the railroad crossing, When a roadside sensor detects a preceding vehicle on the exit side of the railroad crossing, the transmitter transmits the message to the vehicle, the message including one bit of information indicating whether the preceding vehicle in a stopped state is present on the exit side, so that the vehicle does not become stuck at the railroad crossing. Radio base station.

2. When the preceding vehicle exists, the transmitting unit transmits the message including location information indicating the latitude and longitude of the preceding vehicle to the vehicle. The radio base station according to claim 1.

3. The transmitting unit transmits the message to the vehicle, the message further including direction information indicating a traveling direction of the leading vehicle. The radio base station according to claim 2.

4. A mobile station provided in a vehicle, a receiving unit that receives a message by wireless communication from a wireless base station provided in the vicinity of a railroad crossing when the vehicle travels along the road toward an entrance side of the railroad crossing where a railroad and a road intersect, The receiving unit receives from the wireless base station the message including one bit of information indicating whether or not there is a stopped preceding vehicle on the exit side of the railroad crossing detected by a roadside sensor so that the vehicle does not become stuck at the railroad crossing. Mobile station.

5. The mobile station according to claim 4 is provided vehicle.

6. a wireless communication step in which a wireless base station provided in the vicinity of a level crossing where a railroad and a road intersect transmits a message by wireless communication to vehicles traveling on the road toward an entrance side of the level crossing, In the wireless communication step, when a roadside sensor detects a stopped preceding vehicle on the exit side of the railroad crossing so that the vehicle does not become stuck at the railroad crossing, the vehicle is notified of the presence or absence of the preceding vehicle by the message including one bit of information indicating the presence or absence of the preceding vehicle. How to send a message.

Images