JP2011035721A - Communication system between road and vehicle and roadside communication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for increasing a probability of communication establishment between a vehicle having high degree of risk and roadside communication equipment in a communication system between a road and a vehicle. <P>SOLUTION: The communication system between the road and the vehicle has the vehicle having communication equipment and the roadside communication equipment which performs communication with the vehicle to transmit and receive information, wherein the vehicle acquires a traveling state of a self-vehicle including at least a position and speed to transmit the traveling state to the roadside communication equipment, the roadside communication equipment is provided with an assignment control part which determines the degree of risk for each vehicle based on the traveling state received from the vehicle, and assigns many communication resources to the vehicle having high degree of risk. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a roadside communication device that assigns communication resources to each vehicle, and a road-to-vehicle communication system that uses the roadside communication device.

  In an infrastructure collaboration system where vehicles and roadside communication devices exchange information, when the number of vehicles increases and the traffic volume increases, the traffic volume for each channel is averaged by assigning channels for communication with each vehicle. The technique to do is described in Unexamined-Japanese-Patent No. 2008-010920 (patent document 1). Japanese Patent Application Laid-Open No. 2006-352191 discloses a technique for establishing communication between a vehicle and a roadside communication device with low delay in an emergency by setting a priority to a communication packet according to the urgency of communication contents. (Patent Document 2).

JP 2008-010920 A JP 2006-352191 A

  However, the method described in Patent Document 1 has a problem that the quality of service cannot be ensured when the allowable amount of traffic is exceeded. In addition, the method described in Patent Document 2 performs communication in response to a request for emergency communication from a vehicle, and in other words, is an ad hoc method performed every time emergency communication is performed. For this reason, it has been impossible to perform an operation that increases the probability of establishment of communication for each vehicle.

  The present invention has been made in view of the above circumstances, and an object thereof is to improve the probability of establishment of communication between a high-risk vehicle and a roadside communication device in a road-to-vehicle communication system. To provide technology.

In order to achieve the above object, the present invention adopts the following configuration. That is,
A vehicle equipped with a communication device;
A road-to-vehicle communication system having a roadside communication device for communicating with the vehicle to transmit and receive information,
The vehicle acquires a traveling state of the host vehicle including at least a position and a speed and transmits the traveling state to the roadside communication device,
The roadside communication device includes an allocation control unit that determines a risk level for each vehicle based on a traveling state received from the vehicle and allocates a large number of communication resources to a vehicle having a high risk level. It is a road-vehicle communication system.

  In such a road-to-vehicle communication system, the roadside communication device determines the degree of risk based on the position and speed for each vehicle within the range in which the service is provided. And since the allocation amount of a communication resource is changed for every vehicle according to a risk, unlike the conventional road-vehicle communication system, it becomes possible to control the probability that communication will be established for every vehicle.

The present invention can also take the following configurations. That is,
An information acquisition unit that communicates with a vehicle and acquires a traveling state including at least the position and speed of the vehicle;
A roadside communication device comprising: an allocation control unit that determines a risk level of the vehicle based on a received traveling state and allocates a large number of communication resources to the vehicle when the risk level is high.

  Such a roadside communication device communicates with a vehicle within a service providing range, and changes the allocated amount of communication resources according to the danger level of each vehicle, so the probability that communication is established is controlled for each vehicle. It becomes possible to do.

  ADVANTAGE OF THE INVENTION According to this invention, the probability of communication establishment between a roadside communication apparatus and a high risk vehicle can be improved in the road-vehicle communication system.

The block diagram of a roadside communication apparatus and a vehicle. The figure which shows the structure of the whole road-vehicle communication system. The flowchart which shows the outline | summary of a process of a roadside communication apparatus. The flowchart which shows the process of a vehicle. It is a figure which shows the structure of the data used for road-vehicle communication, Fig.5 (a) is a block diagram of a 1 second unit, FIG.5 (b) is a block diagram of each flame | frame. FIG. 6A is a vehicle state determination table and FIG. 6B is a vehicle table. The flowchart which shows time slot allocation. FIG. 9 is a diagram for explaining communication resource allocation according to the third embodiment.

  Exemplary embodiments of the present invention will be described in detail below with reference to the drawings. First, the configuration of the entire road-vehicle communication system is shown in the block diagram of FIG. The road-to-vehicle communication system includes a roadside communication device 1 and a vehicle 2 that are within a service providing range (hereinafter also referred to as a cell). The roadside communication device 1 comprehensively determines the risk based on information collected from the vehicle 2 and the like in order to provide information for preventing the accident to the vehicle 2 in the cell, and limited communication. Determine which vehicle the resource is assigned to and schedule it. In the following explanation, a case where there is one roadside communication device and a plurality of vehicles in one cell is taken as an example. However, the present invention is not limited to this, and a plurality of roadside communication devices perform processing in cooperation. It doesn't matter.

The roadside communication apparatus includes an allocation control unit 11, an antenna 12, a transmission control unit 13, an information acquisition unit 14, a map DB 15, and a camera 16.
The allocation control unit 11 schedules information to be transmitted to the vehicle. The transmission control unit 13 performs wireless communication with each vehicle via the antenna 12. The information acquisition unit 14 extracts information necessary for allocation control from data received from the vehicle via the antenna 12. The map DB 15 stores map information in the cell. The camera 16 is a photographing device for photographing the inside of a cell, and is used for analyzing a picture and detecting a pedestrian.

The map DB 15 stores, for example, matters that affect the operation of the vehicle, such as the position of the road, the width and the speed limit, and the position and size of the buildings and obstacles. In addition, information such as information on the location and number of accidents, traffic regulations, and construction site information is updated and stored as needed. It is also possible to obtain information in cooperation with the outside of the system, for example, VICS (Vehicle Information and Communication System: trademark of Road Traffic Information Communication System Center). The degree can be improved. In the following embodiments, the camera 16 is used only for detecting pedestrians, but the captured image may be analyzed to acquire the position and speed of the vehicle. This allows for a determination that takes into account vehicles that are not equipped with a communication device.

Similarly, in the block diagram of FIG. 1, the vehicle 2 includes an in-vehicle communication device 21, an antenna 22, a vehicle information collection unit 23, a GPS 24, a speedometer 25, an ABS 26, a VSC 27, and a direction indicator 28.
The in-vehicle communication device 21 transmits and receives information to and from the roadside communication device by wireless communication via the antenna 22. The vehicle information collection unit 23 acquires data from each part of the host vehicle connected through the in-vehicle network, and transmits the data to the in-vehicle communication device. The GPS 24 is a terminal of a satellite positioning system and receives a signal from a GPS satellite to acquire the current position of the vehicle. The speedometer 25 detects the speed of the vehicle. The ABS 26 (Antilock Brake System) is a device that prevents the wheels from locking during sudden braking, and the number of times the ABS is operated is stored in a memory (not shown). The VSC 27 (Vehicle Stability Control) is a device that prevents a skid or the like when a sudden steering operation is performed, and the number of times the VSC is operated is stored in a memory (not shown). Hereinafter, the vehicle information transmitted by the in-vehicle communication device is also referred to as a traveling state. The direction indicator 28 is turned on by the operation of the vehicle driver and displays the traveling direction. A CPU (not shown) controls the entire process and gives instructions to each block.

  Note that the reliability of positioning by GPS may be low depending on radio wave conditions. In such a case, you may use the autonomous navigation apparatus which estimates the displacement from the previous position detection result by speed or a direction of travel. In addition to the ABS and VSC shown above, since the vehicle can be provided with various safety devices, the vehicle information collection unit may acquire the operation status thereof. For example, TRC (Traction Control) controls a brake and an engine motor when detecting idling during driving. Moreover, you may acquire the operation condition of VDIM (Vehicle Dynamics Integrated Management: trademark of Toyota Motor Corporation) which integrates and controls this safety device.

<Embodiment 1>
Here, taking the cell shown in FIG. 2 as an example, the process flow of the present invention, that is, a method in which the roadside communication apparatus allocates communication resources for each vehicle based on information from the vehicle and images taken by the camera will be described.

As a communication method between the roadside communication device and the vehicle, various patterns can be considered in a modulation method, a method of encoding and decoding, a method of multiplexing nodes, and a combination thereof. In this embodiment, uplink communication and downlink communication are transmitted and received using the same frequency band secured for road-to-vehicle communication, and the communication direction is controlled by time division. A data structure used in such communication is shown in FIG.
FIG. 5A shows the direction of communication when uplink communication, which is communication from the vehicle to the roadside communication device, and downlink communication, which is communication from the roadside communication device to the vehicle, are performed using the same frequency band. Is shown to be controlled by time division. In the present embodiment, one uplink communication or downlink communication is performed in a period of 50 msec. In other words, the communication direction is switched every 50 msec. As a result, a combination of uplink communication and downlink communication appears 10 times in one second (1u1d, 2u2d,..., 10u10d).

The uplink frame corresponding to uplink communication is further divided into a predetermined number of time slots, and each vehicle transmits information to the roadside communication device using the time slots assigned to the own vehicle. In the present embodiment, as shown in FIG. 5B, 10 time slots are assigned to each upstream frame. Therefore, the time slot period is 5 msec. On the other hand, in the downlink communication time zone, the roadside communication device creates a downlink frame and transmits information. In the present embodiment, the downstream frame does not designate a specific vehicle as a transmission destination, but is broadcasted throughout the cell, and the same information is delivered to all the vehicles.
Here, uplink communication and downlink communication are alternately performed at the same time, but it is not necessarily limited to this. The time may be asymmetric according to the communication status within the cell and the difference between the uplink and downlink information amounts. For example, in a road-to-vehicle communication system, the amount of information in a downstream frame is usually larger than that in an upstream frame, so it may be possible to allocate a long time to downlink communication. Also, the number and period of time slots in the upstream frame can be changed according to the actual communication situation.

The roadside communication apparatus first allocates one time slot per second to a vehicle in a cell in which communication is established for the first time. Accordingly, if the vehicles A, B, and C in FIG. 2 are information transmission targets, an uplink communication period of at least one second is ensured for each vehicle. The number of time slots of 1 per second is an initial value in the present embodiment, and should be set in light of the actual situation of the system. FIG. 5B shows how the initial time slot is set in the upstream frame. Here, the assignment is made in order from the top of the frame 1u, but actually, it may be assigned to any of the frames 1u to 10u. Each vehicle performs uplink communication using the assigned time slot. The information transmitted by each vehicle has a size that can be sufficiently transmitted in one slot. For example, it is about 100 bytes. Subsequent to the initial assignment, an additional assignment according to the risk level of the vehicle is performed. These processes will be described in detail later.
As described above, the downlink frame transmits the same information throughout the cell. In the present embodiment, the roadside communication device collects the traveling state received from each vehicle and the pedestrian position information obtained by analyzing the image captured by the camera, and edits and transmits the information as necessary. In addition, if the downlink frame composed of the combination of the header and the data is repeatedly transmitted a plurality of times during the downlink communication period, the probability that the information reaches the vehicle can be increased.

The outline of the operation of the roadside communication device will be described with reference to the flowchart of FIG.
In step S101, the information acquisition unit of the roadside communication device receives information from each vehicle in the cell and acquires the traveling state. Also, the state of the cell is photographed with a camera.
In step S102, the allocation control unit of the roadside communication device determines how dangerous each vehicle is and records it as a score in the vehicle table. Details of this processing will be described later.
In step S103, the allocation control unit of the roadside communication apparatus allocates communication resources (time slots in the uplink frame) to each vehicle according to the risk determined in the previous step. In addition, a downlink frame for transmission in the cell is created. Details of this processing will be described later.
In step S104, the transmission control unit of the roadside communication device transmits information via the antenna.
The roadside communication device repeats the above operations periodically.

The operation of the vehicle will be described using the flowchart of FIG.
In step S901, the vehicle information collection unit acquires the traveling state of the host vehicle. That is, the position is obtained from the GPS, the speed is obtained from the speedometer, the traveling direction is obtained from the direction indicator, and the number of operations is obtained from the ABS and the VSC.
In step S902, the in-vehicle communication device transmits the traveling state.
In step S903, the in-vehicle communication device receives information from the roadside communication device.
In step S904, the CPU of the vehicle analyzes the received information, determines whether or not a subsequent process is necessary based on the driving state of the surrounding vehicle and the presence or absence of a pedestrian, and performs an appropriate process if necessary.
The vehicle periodically repeats the above operation while in the cell.

Next, details of the process performed by the allocation control unit in step S102 described above will be described with reference to FIG. FIG. 6A is a vehicle state determination table in which various states of the vehicle and scores representing the degree of danger of the state are stored. FIG. 6B is a vehicle table in which one entry is stored for each vehicle. The vehicle state determination table and the vehicle table are held by the assignment control unit, and can be configured using a RAM, a flash memory, or the like according to the characteristics of the apparatus.
The allocation control unit first updates each column of the vehicle table using the traveling state received from each vehicle in step S101 described above. If the vehicle is the first communication established, a new entry is created. Subsequently, a cumulative score is calculated for each vehicle. Specifically, each item in the vehicle state determination table is compared with the value stored in the vehicle table, and if they match, the score is cumulatively added. At that time, the data of the map DB, the image taken by the camera, and the traveling state of other vehicles are also used as appropriate.

Next, details of the process performed by the assignment control unit in step S103 described above will be described with reference to the flowchart of FIG.
In step S501, the allocation control unit allocates one time slot per second as an initial value in the present embodiment for all vehicles. Thereby, one uplink communication period is ensured in any of the upstream frames 1u to 10u in FIG. As a result, minimum communication resources are guaranteed for all vehicles in the cell. The minimum communication resource in this embodiment is one time slot (5 msec) per second.
In step S502, the allocation control unit sums up the cumulative scores of the vehicles that have entries in the vehicle table.
In step S503, the assignment control unit obtains a score ratio by dividing the cumulative score of each vehicle by the total value obtained in the previous step.
In step S504, the allocation control unit allocates time slots according to the score ratio. The number of slots that each vehicle can use is the number obtained by adding the assigned value in this step to one per second assigned as the initial value.

Various calculation methods can be considered for this allocation process. For example, the cumulative score may be classified into ranges, and a predetermined number of slots may be assigned for each range. In other words, if the cumulative score is 1 to 5, one time slot is additionally allocated per second, and if the cumulative score is 6 to 10, two time slots are additionally allocated. Alternatively, when assigning additional time slots, the cumulative score of each vehicle is directly used as the number of timeslots assigned per second, and assignment according to the score ratio is performed only when the number of time slots is insufficient. good.
Further, by comparing the cumulative scores of the vehicles in the cell, one time slot may be allocated to each of the uplink communication periods 1u to 10u in FIG. In this case, a vehicle having the maximum score is provided with a communication opportunity once every 100 msec. Then, time slots are assigned to other vehicles according to the score ratio with the vehicle having the maximum score. According to the above method, communication resources can be distributed according to the score while ensuring a minimum communication opportunity of 1 slot per second for any vehicle.
Also, in the downstream frame, a header part and a broadcast data part are created as shown in FIG. The header portion includes information for specifying that the frame is a downlink frame, time slot allocation information created by the above-described method, and the like. Further, in the present embodiment, the broadcast data section includes information on pedestrians obtained from the running state of each vehicle in the cell, images taken by the photographing device, and other information to be notified. Since one downlink communication period is 50 msec, if it falls within this time, the combination of the header part and the broadcast data part is transmitted multiple times within one period to improve the reception probability on the vehicle side. Also good.

  Subsequently, a series of processes performed in the road-to-vehicle communication system will be described by taking a cell as shown in FIG. 2 as an example. Although the roadside communication device in this example receives information from all the vehicles shown in the figure in the uplink communication, in order to simplify the description, the vehicles A, B, and C in the downlink communication. Only three units are subject to information transmission. Therefore, the risk score is determined only for these three units.

  First, in S901 and S902 in FIG. 4, the vehicle information collection units of the vehicles A, B, and C acquire the traveling state of the host vehicle. And it transmits to a roadside communication apparatus from a vehicle-mounted communication apparatus. In this uplink communication, since the time slot in the initial state described above is used, information transmission is performed once per second.

Next, in S101 of FIG. 3, the information acquisition unit of the roadside communication apparatus analyzes the uplink frame to acquire the traveling state, and acquires the position of the pedestrian based on the image captured by the camera. In S102, first, the entry of each vehicle in the vehicle table is updated. Here, for the vehicles A, B, and C, as shown in FIG. 6B, the position, speed, traveling direction, and the number of operations of the ABS and VSC are recorded.
Subsequently, each vehicle is compared with each item in the vehicle state determination table of FIG. 6A, and an accumulated score is calculated. For example, when looking at vehicle A, the speed is 85 km / h, so it corresponds to “high speed (80 km / h or more)” and the score is plus 2. Since vehicle A is going to enter the same intersection, plus 1 and ABS once Since it is operating, it is plus 1, and the cumulative score is 4. Similarly, the cumulative score of vehicle B is plus 1 because there are pedestrians on the path. Further, the vehicle C is in the crowded vehicle group, so it is plus 1, the vehicle B is going to change lanes, it is plus 1, and the cumulative score is 2. After the determination, the accumulated score is written in the vehicle table of FIG.

  Next, in S103 of FIG. 3, the allocation control unit of the roadside communication device allocates communication resources to each vehicle, that is, schedules time slots and creates a downlink frame. Communication resource allocation is performed along the flow of FIG. In the present embodiment, in S501, one time slot is allocated to each of the vehicles A to C per second. In S502 and S503, the ratio of the cumulative score for each vehicle is obtained. In this case, it is vehicle A: B: C = 4: 1: 2 from FIG.6 (b). In step S504, the remaining time slots in the upstream frame are allocated according to this ratio. In the example of FIG. 5, there are 10 time slots in each of 10 uplink communication periods (1u to 10u), so there are 100 time slots per second. As a distribution method, for example, one time slot is distributed to each of the uplink communication periods 1u to 10u so that the vehicle A having the maximum cumulative score can secure one communication opportunity every 100 msec, and the vehicle For B and C, distribution according to the ratio may be performed.

  In S104 of FIG. 3, the transmission control unit performs data creation and modulation processing, and actually transmits information via the antenna. The configuration of the downstream frame at this time is shown in FIG. In the header (H), it is described which time slot each vehicle is permitted to use. In the data portion, the traveling state collected from each vehicle in the cell and the position information of the pedestrian are stored as broadcast data.

Then, in S903 of FIG. 4, the vehicles A, B, and C receive information. In S904, the CPU of each vehicle determines and executes an appropriate subsequent process according to the information. How to use the received information is defined as the specification of each vehicle, but for example, the following control can be considered.
Since the vehicle A can obtain information that the vehicle A is approaching at the same intersection and cannot be seen with the naked eye, the vehicle A notifies the driver by outputting a voice message or an image to a display unit such as a car navigation system. Also, a warning that the vehicle speed is too fast may be issued. Further, since the vehicle B can obtain information that there is a pedestrian ahead of the left turn, the vehicle B is notified to that effect, or in some cases, an instruction is sent to the braking device to stop the vehicle body. Further, since the vehicle C can obtain information that the vehicle B changes lanes, the vehicle C can notify the driver to that effect. Further, when the inter-vehicle distance between the vehicle C and the vehicles in the crowded vehicle group behind is narrowed, control such as an alert is performed accordingly.

  In the next uplink communication, a vehicle determined to have a high risk score may transmit information to the roadside communication device using more time slots than a vehicle having a low score. it can. If a plurality of time slots are assigned to a certain vehicle, the traveling state can be repeatedly transmitted. As a result, the probability that communication is established between the vehicle having a high score and the roadside communication device is increased, so that the roadside communication device can accurately collect information and create broadcast data, It becomes possible to increase safety. In the above description, the initial value of time slot allocation is specified once per second, but this is not limited to this. For example, if the risk level of the vehicle can be grasped when communication is established for the first time, the number corresponding to the risk level may be assigned from the beginning.

<Embodiment 2>
In this embodiment, different forms of the configuration of the downlink frame created for downlink communication will be described.
As in the first embodiment, when creating a downlink frame as broadcast data, in other words, when including the running state of all the vehicles in the cell and the location information of the pedestrian in the downlink frame, Problems can arise depending on the number of vehicles and pedestrians. That is, if there are many vehicles and pedestrians in the cell, there is a possibility that the size cannot be transmitted in one period of the downlink frame (for example, 50 msec). Thus, the data overflowing from the down frame is not transmitted or is sent to the next down frame, so that the provision of information to the vehicle is insufficient or delayed.
As a countermeasure against such a situation, it is conceivable to flexibly change the period of the downstream frame in accordance with the data size. For example, if a communication period of 70 msec is required to transmit a down frame containing data of all vehicles and pedestrians, information transmission is performed by recording the data length in the header portion. Thereby, downlink communication can be performed without causing data overflow.

However, even when a variable-length frame as described above is used, there may be a problem in data processing in the vehicle. In other words, when viewed from the vehicle side, if the number of vehicles and pedestrians in the cell increases and the data to be processed increases, the data processing time increases or the processing capacity may be exceeded depending on the performance of the CPU. It can happen. As a result, a situation may occur in which subsequent processing required on the vehicle side is not in time.
As a countermeasure for such a situation, it is conceivable to reduce the data size of the downstream frame. In other words, the traveling state of the vehicle that is unlikely to affect other vehicles and the position information of the pedestrian are created so as not to be included in the broadcast data.
One example of a specific method is as follows. First, an item “is there another vehicle within 50 m from the host vehicle” is added to the vehicle table of FIG. If “no other vehicle is present”, the traveling state of the vehicle is not included in the descending frame. Note that the threshold to be excluded from the downlink frame may simply be a distance, but the speed of the vehicle and the traveling direction may be taken into consideration. As a result, it is possible to prevent data from overflowing from the period of the downstream frame. In addition, even when the processing capability of the CPU of the vehicle is low, the relationship with other vehicles can be determined, so that it is possible to select an appropriate subsequent process.

<Embodiment 3>
This embodiment demonstrates the form from which the communication system between a roadside communication apparatus and a vehicle differs.
Here, OFDMA (Orthogonal Frequency Division Multiplexing Access) is used as an access method for wireless communication to establish communication between the roadside communication device and a large number of vehicles. The concept of communication resource allocation in this embodiment is shown in FIG. A frequency of 1.0 MHz that can be used for road-to-vehicle communication is divided into 100 subcarriers, and data is spread over this bandwidth and transmitted. Furthermore, the concept of time division is adopted here, and one frame period (5 msec) is divided into n at equal intervals. Thus, the slot represented by the subcarrier and time becomes a communication resource in this embodiment.

  By configuring the communication resources as described above, the configuration can be flexibly changed, so that communication within the road-vehicle communication system can be performed efficiently. In this embodiment, communication resources are also allocated to the downstream frame as shown in FIG. As a result, for example, for vehicles with a high score representing the degree of danger, it is considered that the content instructed from the roadside communication device will increase. Both link communications can be enhanced.

DESCRIPTION OF SYMBOLS 1 Roadside communication apparatus 11 Assignment control part 13 Transmission control part 14 Information acquisition part 2 Vehicle 21 In-vehicle communication apparatus 23 Vehicle information collection part

Claims (8)

A vehicle equipped with a communication device;
A road-to-vehicle communication system having a roadside communication device for communicating with the vehicle to transmit and receive information,
The vehicle acquires a traveling state of the host vehicle including at least a position and a speed and transmits the traveling state to the roadside communication device,
The roadside communication device includes an allocation control unit that determines a risk level for each vehicle based on a traveling state received from the vehicle and allocates a large number of communication resources to a vehicle having a high risk level. Road-to-vehicle communication system. The road-to-vehicle communication system according to claim 1, wherein the allocation control unit determines that the risk is higher as the speed of the vehicle is higher. 3. The road-to-vehicle communication system according to claim 1, wherein the allocation control unit makes a determination so as to increase a degree of danger when the vehicle is at a point where accidents frequently occur. The traveling state further includes an operation history of a vehicle safety device,
The road-to-vehicle communication system according to any one of claims 1 to 3, wherein the allocation control unit determines that the degree of danger is higher as the number of times the safety device is operated. The allocation control unit
Based on the traveling state of the vehicle for which communication has been established, it is determined whether each vehicle is in a congested situation and whether there is a possibility of contact with another vehicle, and the risk is determined based on the result of the determination. The road-to-vehicle communication system according to any one of claims 1 to 4, wherein the degree is determined. It further has a photographing device that senses a pedestrian by photographing inside the cell that provides the service,
The traveling state further includes a traveling direction of the vehicle,
The road-to-vehicle communication system according to any one of claims 1 to 5, wherein the assignment control unit performs determination to increase the degree of danger when a pedestrian is present in a traveling direction of the vehicle. The road-to-vehicle communication system according to any one of claims 1 to 6, wherein the communication resource is a time slot for performing communication multiplexed by frequency division and / or time division. An information acquisition unit that communicates with a vehicle and acquires a traveling state including at least the position and speed of the vehicle;
A roadside communication apparatus comprising: an allocation control unit that determines a risk level of the vehicle based on the received traveling state and allocates a large number of communication resources to the vehicle when the risk level is high.

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