Message relay device, in-vehicle device, communication system, message relay method and program

Abstract

This message relay device comprises: a first antenna directed in a first direction; a second antenna directed in a second direction different from the first direction; a receiving unit that is capable of receiving, from one mobile body, a message that is for another mobile body and includes delivery request area information; an antenna selecting unit that selects either the first antenna or the second antenna on the basis of setting information that defines a relationship between a delivery request area indicated in the delivery request area information and the antenna to be selected; and a transmitting unit that uses the selected antenna and transmits the message received by the receiving unit.

Description

[Technical field]

[0001] The present invention relates to a message relay device, an in-vehicle device, a communication system, a message relay method, and program Regarding. [Background technology]

[0002] Research is being conducted into vehicle-to-vehicle communication (also known as V2V communication, where V2V stands for vehicle-to-vehicle), which allows vehicles to exchange information about surrounding vehicles and road conditions with other vehicles. Vehicle-to-vehicle communication can be broadly divided into direct communication using a PC5 interface and communication via a base station using a UU interface.

[0003] Patent Document 1 discloses a server including a distribution area determination unit that determines a distribution area in which multiple mobile objects to which information is to be distributed are located, a transmission target determination unit that selects and determines a mobile object to which unicast transmission is to be performed via a mobile communication base station based on location information of the multiple mobile objects located within the distribution area, and an information transmission unit that unicasts the information to the mobile object to which unicast transmission is to be performed via the mobile communication base station. Specifically, when the server of Patent Document 1 receives information on a dangerous event from a vehicle, the server determines an area to which the information on the dangerous event is to be distributed based on the content of the information (see paragraph 0038). Then, the server selects a vehicle located within the distribution area based on location information of the mobile object (vehicle) that is known in advance (see paragraph 0039). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-202591 A Summary of the Invention [Problem to be solved by the invention]

[0005] The following analysis is given by the inventor. In the method of Patent Document 1, the server determines the distribution area based on the dangerous event information received from the vehicle, which generates calculation processing in the server, which may cause a transmission delay. In addition, after determining the distribution area, the server of Patent Document 1 needs to select vehicles located in this distribution area, which may cause a transmission delay. Furthermore, the server of Patent Document 1 uses unicast to transmit the dangerous event information, which may cause a delay due to the order in which the unicast is performed.

[0006] The present invention relates to a message relay device, an in-vehicle device, a communication system, a message relay method, and a method for relaying a message between mobile units, which can contribute to reducing transmission delays in communication between mobile units via a base station. program The purpose is to provide. [Means for solving the problem]

[0007] According to a first aspect, there is provided a message relay device comprising: a first antenna oriented in a first direction; a second antenna oriented in a second direction different from the first direction; a receiving unit capable of receiving from one mobile body a message including distribution request area information intended for another mobile body; an antenna selecting unit selecting either the first antenna or the second antenna based on setting information that defines a relationship between a distribution request area indicated in the distribution request area information and an antenna to be selected; and a transmitting unit that transmits the message received by the receiving unit using the selected antenna.

[0008] According to a second aspect, there is provided an in-vehicle device including a means for transmitting a message including the distribution request area information, addressed to another moving body, to the message relay device.

[0009] According to a third aspect, there is provided a communication system including the above-mentioned message relay device and the above-mentioned vehicle-mounted device.

[0010] According to a fourth aspect, there is provided a message relay method in which a message relay device equipped with a first antenna pointing in a first direction and a second antenna pointing in a second direction different from the first direction receives a message including distribution request area information from one mobile body and is intended for another mobile body, selects either the first antenna or the second antenna based on setting information that defines a relationship between the distribution request area indicated in the distribution request area information and the antenna to be selected, and transmits the received message using the selected antenna. This method is associated with a specific machine, namely the message relay device equipped with the first and second antennas.

[0011] According to a fifth aspect, there is provided a message relay method in which the above-mentioned on-board device transmits a message including distribution request area information to the message relay device, causes the message relay device to select either the first antenna or the second antenna based on setting information that defines a relationship between the distribution request area indicated in the distribution request area information and the antenna to be selected, and causes the message relay device to transmit the received message using the selected antenna. This method is associated with a specific machine, that is, an on-board device capable of transmitting a message to the message relay device equipped with the first and second antennas.

[0012] According to a sixth aspect, there is provided a computer program (hereinafter, "program") for implementing each function of the message relay device and the in-vehicle device described above. This program is input to the computer device from an input device or from the outside via a communication interface, stored in a storage device, and drives the processor according to a predetermined step or process. This program can also display the processing result, including an intermediate state, at each stage via a display device as necessary, or can communicate with the outside via the communication interface. For example, the computer device for this purpose typically includes a processor, a storage device, an input device, a communication interface, and a display device as necessary, which are connectable to each other via a bus. This program can also be recorded on a computer-readable (non-transitive) storage medium. Effect of the Invention

[0013] According to the present invention, it is possible to reduce transmission delays in communications between mobile units via base stations. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing a configuration of an embodiment of the present invention. [Diagram 2] FIG. 2 is a diagram for explaining the operation of one embodiment of the present invention. [Diagram 3] FIG. 2 is a diagram for explaining the operation of one embodiment of the present invention. [Figure 4] FIG. 1 is a diagram showing a configuration of a first exemplary embodiment of the present invention. [Diagram 5] FIG. 2 is a diagram illustrating a configuration of a base station according to the first exemplary embodiment of the present invention. [Figure 6] FIG. 2 is a schematic diagram showing an arrangement of antennas of a base station according to the first embodiment of the present invention. [Figure 7] 4 is a diagram for explaining the contents of a message type included in a message by an in-vehicle device according to the first embodiment of the present invention; FIG. [Figure 8]FIG. 4 is a diagram for explaining processing contents for each message type by a base station according to the first embodiment of the present invention. [Figure 9] FIG. 4 is a diagram illustrating an example of setting information set in a base station according to the first embodiment of the present invention. [Figure 10] FIG. 2 is a diagram for explaining the operation of a base station according to the first embodiment of the present invention. [Figure 11] FIG. 2 is a diagram for explaining the operation of a base station according to the first embodiment of the present invention. [Figure 12] FIG. 11 is a diagram for explaining the operation of a base station according to the second exemplary embodiment of the present invention. [Figure 13] FIG. 11 is a diagram illustrating a positional relationship between a base station and adjacent base stations according to a third exemplary embodiment of the present invention. [Figure 14] FIG. 11 is a diagram for explaining processing contents for each message type by a base station according to the third embodiment of the present invention. [Figure 15] FIG. 11 is a diagram for explaining the operation of a base station according to the third exemplary embodiment of the present invention. [Figure 16] FIG. 11 is a diagram for explaining the operation of a base station according to the third exemplary embodiment of the present invention. [Figure 17] FIG. 2 is a diagram showing a configuration of a computer mounted on the message relay device or the vehicle-mounted device of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] First, an overview of one embodiment of the present invention will be described with reference to the drawings. Note that the reference numerals in the drawings are added to each element for convenience as an example to aid in understanding, and are not intended to limit the present invention to the illustrated embodiment. Also, the connection lines between blocks in the drawings and the like referred to in the following description include both bidirectional and unidirectional. A unidirectional arrow is a schematic representation of the flow of a main signal (data), and does not exclude bidirectionality. A program is executed via a computer device, which includes, for example, a processor, a storage device, an input device, a communication interface, and a display device as necessary. Also, this computer device is configured to be able to communicate with devices (including computers) inside or outside the device via the communication interface, regardless of whether it is wired or wireless. Also, although there are ports or interfaces at the connection points of input and output of each block in the drawing, they are not shown.

[0016] In one embodiment of the present invention, as shown in FIG. 1, a message relay device includes a first antenna 14, a second antenna 15, a receiving unit 11, an antenna selection unit 12, and a transmitting unit 13. 10 This can be realized by:

[0017] More specifically, the first antenna 14 is oriented in a first direction, and the second antenna 15 is oriented in a second direction that is different from the first direction.

[0018] The receiving unit 11 receives a message including distribution request area information from one mobile unit 20 via one of the antennas 14 and 15, the message being addressed to another mobile unit. As the distribution request area information, for example, information directly or indirectly specifying the transmission area (distribution request area) of the antennas 14 and 15 can be used. When directly specifying information is used, location information of the transmission area (distribution request area) corresponding to the location information or the traveling section of the road is sent to the mobile unit 20. of A method of distributing the information in advance may be adopted.

[0019] The antenna selection unit 12 selects either the first antenna 14 or the second antenna 15 based on setting information that defines the relationship between a delivery request area and a selected antenna. Furthermore, if a delivery request area that is not defined in the setting information is set, the antenna selection unit 12 does not select an antenna. For example, the setting information may be simple, such as delivery request area 11=transmission by antenna 14, delivery request area 12=transmission by antenna 15. Of course, a more advanced method of determining the delivery area may also be adopted depending on the message contents.

[0020] A transmitting unit 13 transmits the message received by the receiving unit 11 using the antenna selected by the antenna selecting unit 12 .

[0021] Fig. 2 is a diagram for explaining the operation of one embodiment of the present invention. For example, as shown in Fig. 2, it is assumed that a mobile unit 20 has acquired information to be notified to other mobile units. Here, it is assumed, for example, that the mobile unit 20 has detected the occurrence of an accident ahead of area 11 (Area 11). In this case, the mobile unit 20 transmits a message including delivery request area information to other mobile units using broadcast. In the example of Fig. 2, area 12 (Area 12) that can be transmitted by antenna 15 of message relay device 10 is specified as the delivery request area information.

[0022] The message relay device 10 that receives such a message addressed to another mobile unit operates as follows. First, the antenna selection unit 12 refers to the setting information and selects the antenna 15 corresponding to the delivery request area 12 (Area 12) from among the antennas 14 and 15. Then, the transmission unit 13 broadcasts the message received by the reception unit 11 using the antenna 15 selected by the antenna selection unit 12. As a result, the message sent by the mobile unit 20 and addressed to the other mobile unit is broadcast to the area 12 (Area 12) using the antenna 15 of the message relay device 10. As a result, the other mobile units located in the area 12 can obtain information that an accident has occurred ahead of the area 11 (Area 11).

[0023] On the other hand, there may be cases where a delivery request area not specified in the setting information is set in the delivery request area information. Fig. 3 shows the message relay device 10 when the delivery request area indicated in the delivery area information is the delivery area X2 of a message relay device X other than the message relay device 10. As shown in Fig. 3, when the antenna selection unit 12 refers to the setting information and determines that neither of the antennas 14, 15 is supported, it does not select an antenna. Since no antenna selection is performed, the transmission unit 13 also suppresses the transmission of the message received by the reception unit 11.

[0024] As described above, according to this embodiment, it is possible to reduce the transmission delay of communication between mobile objects via a base station. Furthermore, in this embodiment, when an area not supported by either antenna 14 or 15 is a delivery request area, the transmission of a message using broadcast is suppressed, so that it is also possible to save radio wave resources.

[0025] [First embodiment] Next, a first embodiment of the present invention will be described in detail with reference to the drawings. Fig. 4 is a diagram showing the configuration of the first embodiment of the present invention. Referring to Fig. 4, the configuration includes a base station 100 and a vehicle 200 equipped with an on-board device 210 capable of transmitting a message including message type information to the base station 100 and intended for other moving bodies such as other vehicles.

[0026] The base station 100 is a base station that functions as a message relay device. As such a base station 100, a base station compatible with a fifth generation communication system (5G) or LTE (Long Term Evolution) used to realize communication between vehicles and road infrastructure called C-V2X can be used. In the following embodiment, the base station 100 will be described as a base station compatible with 5G.

[0027] The on-board device 210 mounted on the vehicle 200 includes a message creation unit 211 and a message transmission unit 212. The message creation unit 211 operates when a predetermined event occurs, and 100 The antenna selection unit 102 (FIG. 5) creates a message for other mobile units, which contains information called a message type that can be interpreted. The body of the message can contain information notifying the occurrence of an accident, the presence of a fallen object, damage to the road, etc.

[0028] Message sending section 212 transmits the message created by message creating section 211 to base station 100. Details of the message types will be explained later with reference to FIG.

[0029] Next, the configuration of the base station 100 will be described in detail with reference to Fig. 5 and Fig. 6. Fig. 5 shows the configuration of the base station 100 according to the first embodiment of the present invention. 1005 is a diagram showing a configuration of the mobile communication system. Referring to FIG. 5, the mobile communication system includes three antennas 104 to 106, a receiving unit 101, an antenna selecting unit 102, and a transmitting unit 103. In this embodiment, the antennas 104 to 106 are described as being directional antennas, each having an angular coverage of about 120°. Specifically, as shown in FIG. 6, the antennas 104 to 106 are described as being capable of transmitting messages to areas A104 to A106, respectively.

[0030] When the receiver 101 receives a message from the vehicle 200 that is intended for another moving body, it notifies the antenna selector 102 of the message type contained in the header or the like and the combination of the receiving antennas.

[0031] The antenna selection unit 102 selects a transmission antenna from the message type and the reception antenna information based on preset setting information. The transmission unit 103 broadcasts the message from the antenna selected by the antenna selection unit 102.

[0032] As an example of information for indirectly specifying distribution request area information, a message type to be included in a message transmitted by the in-vehicle device 210 will be described here. FIG. 7 is a diagram for explaining the contents of a message type to be included in a message by the in-vehicle device 210 of this embodiment. The message type of this embodiment is composed of a combination of two information elements. The first information element indicates the traveling direction (absolute direction) of the vehicle, with "1" representing east (E), "2" representing north (N), "3" representing west (W), and "4" representing south (S). The second information element indicates the message transmission request direction as seen from the vehicle, with "1" representing forward (F) and "2" representing backward (R). Thus, message type 1-1 indicates that the message is a message requested to be transmitted forward by a vehicle traveling east. Similarly, message type 1-2 indicates that the message is a message requested to be transmitted backward by a vehicle traveling east.

[0033] The base station 100 selects an antenna from which to transmit each message, using the antenna that received the message and the message type. FIG. 8 is a diagram for explaining the processing contents for each message type of the message received by the base station 100 at the antenna 104 in the first embodiment of the present invention. When the antenna 104 receives a message, the vehicle that is the sender is located in the range from due south to due northeast of the base station 100. When a message of message type 1-1 is received from such a vehicle, the sender is traveling to the east, and the sender is requested to transmit a message further ahead. As shown in FIG. 6, the base station 100 does not have an antenna that can transmit a message east of the distribution area A104 of the antenna 104, so the base station 100 discards the message of message type 1-1. On the other hand, when a message of message type 1-2 is received, the sender is traveling to the east, and the sender is requested to transmit a message further ahead. As shown in FIG. 6, the base station 100 has an antenna 105 capable of transmitting a message to an area A105 west of the distribution area A104 of the antenna 104, so the base station 100 selects the antenna 105. Similarly, when the base station 100 receives a message of message type 2-1, the sender is traveling northward, and a message transmission is requested ahead of the area. As shown in FIG. 6, the base station 100 has an antenna 106 capable of transmitting to an area A106 northward of the distribution area A104 of the antenna 104, so the base station 100 selects the antenna 106. On the other hand, when the base station 100 receives a message of message type 2-2, the sender is traveling northward, and a message transmission is requested behind the area. As shown in FIG. 6, the base station 100 does not have an antenna capable of transmitting a message south of the distribution area A104 of the antenna 104, so the base station 100 discards the message of message type 2-2.

[0034] By performing the above calculations, setting information is created that specifies the selected antenna for each message type for each receiving antenna, and the setting information is stored in the antenna selection unit 102, thereby enabling the transfer of messages with little delay. 100 9 is a diagram showing an example of setting information set in the . In the example of FIG. 9, for each receiving antenna, the message type to be transferred and the antenna (transmitting antenna) to be selected at that time are specified. By using such setting information, it is possible to quickly determine the transmitting antenna from the combination of the receiving antenna and the message type of the message. Note that combinations that are not specified in the setting information are determined by the base station 100 described above. inability Since the distribution request area is an area that is not available, the request will be discarded.

[0035] Next, the operation of this embodiment will be described in detail with reference to the drawings. 100 10 is a diagram for explaining the operation of the base station 100. Fig. 10 is a diagram showing the operation when the vehicle 200, heading east (E) from a position southeast of the base station 100, discovers an accident ahead. In this case, the message creation unit 211 of the in-vehicle device 210 of the vehicle 200 transmits a message MSG(1-2) including a message type 1-2 to the base station 100 to notify the following vehicle of the occurrence of the accident.

[0036] The base station 100, which has received the message MSG(1-2), refers to the setting information exemplified in FIG. 8 and selects the antenna 105 as the transmitting antenna for the message MSG(1-2). The base station 100 then broadcasts the message MSG(1-2) received from the vehicle 200 using the selected antenna 105. This enables the vehicle 200 located in the area A105 in FIG. 6 to receive the message MSG(1-2). In the above process, the transmitting antenna 105 is selected based on the message type included in the message MSG(1-2) without performing any calculation process. This results in a smaller transmission delay than the method of Patent Document 1 and the like.

[0037] 11 shows the operation when a vehicle 200 heading east (E) from a position southeast of the base station 100 discovers an abnormality on a road it has already traveled. In this case, the message creation unit 211 of the in-vehicle device 210 of the vehicle 200 sends a abnormality In order to notify base station 100 of the occurrence of the message, a message MSG(1-1) including a message type 1-1 is transmitted to base station 100.

[0038] The base station 100 that has received the message MSG(1-1) discards the received message MSG(1-1) without selecting an antenna because the transmission antenna for the message MSG(1-1) is not specified in the setting information illustrated in Fig. 8. This avoids wasteful use of the radio resources of the base station 100 and surrounding vehicles.

[0039] As described above, according to this embodiment, it is possible to realize the transmission of messages between vehicles with little transmission delay. Also, as described with reference to Fig. 11, messages that cannot be transmitted to the requested area are discarded, so that the use of wireless resources is avoided. This reduces the effects of delays, etc., when transmitting a message to be transmitted.

[0040] [Second embodiment] Next, a second embodiment in which the number of times a message is repeatedly transmitted can be set in a message will be described in detail with reference to the drawings. The second embodiment can be realized with a configuration almost similar to that of the first embodiment, so the following description will focus on the differences. Figure 12 is a diagram for explaining the operation of a base station in the second embodiment of the present invention.

[0041] The message creation unit 211a of the in-vehicle device 210a of this embodiment creates messages for other moving bodies. To In addition to the message type, it is possible to specify the number of times the message should be repeated.

[0042] Therefore, when a specified event occurs, the in-vehicle device 210a of this embodiment transmits to the base station 100a a message MSG(1-2, rpt=n) for other moving bodies, which includes a message type and the number of times the message is to be repeatedly transmitted, rpt.

[0043] The base station 100a receives a message MSG(1-2, rpt=n) for other mobile units, which includes the message type and the number of times rpt the message is repeatedly transmitted, and selects a transmission antenna based on the message type, as in the first embodiment. The base station 100a then uses the selected antenna to repeatedly transmit the message for other mobile units the number of times n, which is specified by the number of times rpt. Note that a predetermined time may be used as the interval for transmitting the message.

[0044] According to this embodiment, which operates as described above, it becomes possible for a message sent from one vehicle to reach a larger number of vehicles. In the above embodiment, the message transmission interval has been described as a predetermined time, but the transmission interval may be set arbitrarily by the transmission source vehicle 200a. In this case, the transmission interval may be included in the message addressed to other moving bodies in addition to the message type and the number of repeated transmissions of the message rpt, and a function for interpreting this may be added to the base station 100a side.

[0045] In the above embodiment, the source mobile unit has set Repeated messages Although an example of repeatedly transmitting the signal based on the number of transmissions rpt has been described, 100a In this case, the base station may set the number of repeated transmissions rpt_i to be applied to the inter-vehicle message in advance. 100a When a mobile station receives a message including the repeat transmission count rpt from a source mobile station and is intended for another mobile station, the repeat transmission count rpt_i may be changed to the repeat transmission count rpt.

[0046] [Third embodiment] Next, a third embodiment in which a plurality of base stations can cooperate to deliver to an appropriate area even if a delivery request area specified by a message type is an area that cannot be delivered by one base station will be described in detail with reference to the drawings. FIG. 13 is a diagram showing the positional relationship between a base station and adjacent base stations in the third embodiment of the present invention. In the following description, it is assumed that adjacent base stations 100-N, 100-E, 100-S, and 100-W are arranged to the north, south, east, and west of a base station 100b as shown in FIG. The connection between the base station 100b and the adjacent base stations 100-N, 100-E, 100-S, and 100-W may be wired or wireless.

[0047] Also, the adjacent base stations 100-N, 100-E, 100-S, and 100-W will be described as each having a function of transmitting a message when a message transmission request is received from the base station 100b.

[0048] FIG. 14 is a diagram for explaining the processing contents for each message type by the base station 100b of this embodiment. The difference from the processing contents for each message type shown in FIG. 8 is that for the message types for which a transmitting antenna was not selected in FIG. 8, it is specified that a request is made to an adjacent base station to transmit a message. For example, in the example of FIG. 8, when a message of message type 1-1 is received, the message is discarded, but in the example of FIG. 14, it is specified that a request is made to the adjacent base station 100-E located on the east side of the base station 100b to transmit a message. Similarly, in the example of FIG. 8, when a message of message type 2-2 ...b to transmit a message. south The adjacent base station 100- S It is stipulated that a request to send a message is made to the

[0049] By using the above-mentioned setting information, the following operation becomes possible. Fig. 15 is a diagram showing the operation when a vehicle 200-1 heading west (W) from a position southeast of the base station 100b discovers an accident ahead. In this case, the message creation unit 211 of the in-vehicle device 210 of the vehicle 200-1 sends a message to the base station 100b in order to notify the following vehicles of the occurrence of the accident. b sends a message MSG(3-2) including message type 3-2 to the

[0050] The base station 100b that has received the message MSG(3-2) refers to the setting information exemplified in FIG. 14 and selects the adjacent base station 100-E as the transmitting base station of the message MSG(3-2). Then, the base station 100b requests the selected base station 100-E to broadcast the message MSG(3-2) received from the vehicle 200-1. The adjacent base station 100-E that has received the request broadcasts the message MSG(3-2) received from the vehicle 200-1 as requested by the base station 100b. This makes it possible to quickly notify the vehicles 200-2 and 200-3 that are following the vehicle 200-1 of the accident ahead, as shown in FIG. 15.

[0051] 16 is a diagram showing the operation when a vehicle 200-1 traveling east (E) from a position southeast of the base station 100b discovers a foreign object (TIRE) that has fallen in the oncoming lane. In this case, the message creation unit 211 of the in-vehicle device 210 of the vehicle 200-1 transmits a message MSG(1-1) including a message type 1-1 to the base station 100b to inform the oncoming vehicle of the presence of the fallen object.

[0052] The base station 100b that has received the message MSG(1-1) refers to the setting information exemplified in FIG. 14 and selects the adjacent base station 100-E as the transmitting base station of the message MSG(1-1). Then, the base station 100b requests the selected adjacent base station 100-E to broadcast the message MSG(1-1) received from the vehicle 200-1. The base station 100-E that has received the request broadcasts the message MSG(1-1) received from the vehicle 200-1 as requested by the base station 100b. This makes it possible to quickly inform the vehicles 200-2 and 200-3 traveling in the oncoming lane of the vehicle 200-1 of the presence of a fallen object ahead, as shown in FIG. 16.

[0053] According to this embodiment that operates as described above, it becomes possible to transfer messages over a wider range. In the above embodiment, the adjacent base station 100-E is described as not selecting an antenna in particular, but the adjacent base station 100-E may also select an antenna using a message type. For example, in the case of FIG. 15, when the adjacent base station 100-E is requested by the base station 100b to transmit a message of message type 3-2, the adjacent base station 100-E may be configured to select a specific antenna of the adjacent base station 100-E and transmit the message only to the vehicle 200-2.

[0054] In the above embodiment, the base station 100b does not consider the distance to the adjacent base station when selecting the adjacent base station. However, the base station 100b may consider the distance to the adjacent base station when selecting the adjacent base station and decide whether or not to transmit the message. For example, when the distance to the adjacent base station is several kilometers or more, depending on the content of the message, there is a possibility that there is no need to notify the adjacent base station or the effect of the warning may be weakened. In such a case, it is preferable that the base station 100b considers the content of the message and the distance to the adjacent base station and decides whether or not to request the adjacent base station to transmit the message.

[0055] Although each embodiment of the present invention has been described above, the present invention is not limited to the above-mentioned embodiments, and further modifications, substitutions, and adjustments can be made without departing from the basic technical idea of ​​the present invention. For example, the system configuration, the configuration of each element, and the data expression form shown in each drawing are examples to help understand the present invention, and the present invention is not limited to the configurations shown in these drawings.

[0056] In the above embodiment, a total of eight message types consisting of the travel direction (absolute direction) of the vehicle and the message transmission request direction as seen from the vehicle (two values, forward and backward) are used, but the expression form of the message type is not limited to this. For example, on a highway or the like, when the travel direction of the vehicle is substantially two-way, the travel direction (absolute direction) of the vehicle becomes two-value. In addition to the message transmission request direction (two values, forward and backward), the left and right directions and the distance from the vehicle may be specified. For example, when specifying the distance from the vehicle, it may be possible to specify "rearward, within 300-1000 m from the vehicle". In this case, setting information corresponding to these message types may also be set in the antenna selection unit of the message relay device (base station).

[0057] In addition, in the above-described embodiment, a vehicle is assumed as a moving object, but the present invention can also be applied to relaying messages between pedestrians, flying objects (drones), etc.

[0058] In addition, in the above embodiment, an example was given in which a base station having three antennas was used, but the number of antennas is not limited as long as it is equal to or greater than 2. In addition, in the above embodiment, an example was given in which a base station was used as a message relay device, but the message relay device may be other communication devices such as a roadside unit or a wireless access point.

[0059] Moreover, the procedures shown in the above-mentioned first to third embodiments can be realized by a program that causes a computer (9000 in FIG. 17) that functions as a base station or an on-board device of a vehicle to realize the functions of these devices. Such a computer is exemplified by a configuration including a CPU (Central Processing Unit) 9010, a communication interface 9020, a memory 9030, and an auxiliary storage device 9040 in FIG. 17. That is, the CPU 9010 in FIG. 17 may execute a message transmission program or a message transfer program, and may perform an update process of each calculation parameter held in the auxiliary storage device 9040 or the like.

[0060] In other words, each unit (processing means, functions) of each device shown in the first to third embodiments described above can be realized by a computer program that causes a processor installed in these devices to execute each of the above-mentioned processes using its hardware.

[0061] Finally, preferred embodiments of the present invention will be summarized. [First form] (See the message relay device according to the first aspect above.) [Second Form] The message relay device described above may be configured to discard the message if the antenna selection unit does not select an antenna based on the setting information. [Third Form] The delivery request area information included in the message received by the message relay device is information that specifies the transmission areas of the first and second antennas of the message relay device, The antenna selection unit may be configured to select an antenna corresponding to the transmission area. [Fourth Form] The delivery request area information included in the message received by the message relay device includes a traveling direction of the moving body and a transmission request direction based on a position of the moving body, The antenna selection unit may be configured to select an antenna capable of transmitting the message based on setting information that defines a transmitting antenna based on a combination of the distribution request area information and the antenna that received the message. [Fifth Form] The antenna selection unit of the message relay device includes: A moving body located in the first direction, a message traveling in the first direction and having a request to send in the second direction; selecting the second antenna in the case of any message traveling in the second direction and having a transmission request direction in the first direction; A moving body located in a second direction, a message traveling in the second direction and having a transmission request direction in the first direction; A configuration may be adopted in which the first antenna is selected in the case of any of the messages traveling in the first direction and having the second direction as a transmission request direction. [Sixth Form] The number of transmission requests can be set for the message received by the message relay device. The transmission section may be configured to repeat transmission of the message at a predetermined time interval for a number of times designated by the number of transmission requests. [7th form] The message relay device is connected to an adjacent message relay device, A configuration may be adopted in which a request is made to transmit the message to adjacent message relay devices located in a direction defined by the distribution request area information. [8th form] (See the above second aspect of the in-vehicle device.) [9th form] (See communication system from the third viewpoint above) [10th form] (See the fourth aspect of message relaying method above) [11th form] (See the fifth aspect of message relaying method above) [12th form] (See Programme for the 6th Aspect above) The eighth to twelfth embodiments can be expanded into the second to seventh embodiments in the same manner as the first embodiment.

[0062] The disclosures of the above patent documents are incorporated herein by reference and may be used as the basis or part of the present invention as necessary. Within the framework of the entire disclosure of the present invention (including the scope of claims), modifications and adjustments of the embodiments and examples are possible based on the basic technical ideas. Furthermore, within the framework of the disclosure of the present invention, various combinations or selections (including partial deletions) of various disclosed elements (including each element of each claim, each element of each embodiment or example, each element of each drawing, etc.) are possible. In other words, the present invention naturally includes various modifications and corrections that a person skilled in the art would be able to make in accordance with the entire disclosure including the scope of claims and the technical ideas. In particular, with regard to the numerical ranges described in this document, any numerical value or small range included within the range should be interpreted as being specifically described even if not otherwise specified. Furthermore, the disclosures of the above cited documents may be used in part or in whole in combination with the disclosures of this document as part of the disclosure of the present invention in accordance with the spirit of the present invention as necessary, and are deemed to be included in the disclosures of this application. [Explanation of symbols]

[0063] 10 Message Relay Device 11, 101 Receiver 12, 102 Antenna selection unit 13, 103 Transmitter 14 First Antenna 15 Second Antenna 20 Mobile 100 base stations 200, 200a, 200-1~200-3 vehicles 210, 210a Onboard equipment 211, 211a Message Creation Department 212 Message sending unit 100, 100a, 100b base station 100-E, 100-N, 100-W, 100-S Adjacent base stations 104~106 Antenna 9000 Computers 9010 CPU 9020 Communication Interface 9030 Memory 9040 Auxiliary storage device

Claims

1. a first antenna pointing in a first direction; a second antenna pointing in a second direction different from the first direction; a receiving unit capable of receiving, from one mobile unit, a message including distribution request area information and intended for another mobile unit; an antenna selection unit that selects, for each antenna that has received the message, either the first antenna or the second antenna based on setting information that defines a relationship between the distribution request area indicated in the distribution request area information and an antenna to be selected; a transmitting unit that transmits the message received by the receiving unit using the selected antenna; A message relay device comprising:

2. A message relay device according to claim 1, which discards the message if the delivery request area indicated in the delivery request area information is not specified in the setting information.

3. the delivery request area information is information specifying a transmission area of ​​either the first antenna or the second antenna of the message relay device, 3. The message relay device according to claim 1, wherein the antenna selection unit selects an antenna corresponding to the transmission area.

4. the delivery request area information includes a traveling direction of the one moving body and a transmission request direction based on a position of the one moving body, The message relay device of claim 1 or 2, wherein the antenna selection unit associates the traveling direction, the transmission request direction, and the antenna to be selected for each antenna that receives the message and stores them as the setting information, and selects either the first antenna or the second antenna based on the stored setting information, thereby selecting an antenna capable of transmitting the message.

5. a first antenna pointing in a first direction; a second antenna pointing in a second direction different from the first direction; a receiving unit capable of receiving, from one mobile unit, a message including distribution request area information and intended for another mobile unit; an antenna selection unit that selects, for each antenna that has received the message, either the first antenna or the second antenna based on setting information that defines a relationship between the distribution request area indicated in the distribution request area information and an antenna to be selected; a transmitting unit that transmits the message received by the receiving unit using the selected antenna; A message relay device comprising: An in-vehicle device comprising: a means for transmitting the message including the distribution request area information and addressed to another moving body.

6. a first antenna pointing in a first direction; a second antenna pointing in a second direction different from the first direction; a receiving unit capable of receiving, from one mobile unit, a message including distribution request area information and intended for another mobile unit; an antenna selection unit that selects, for each antenna that has received the message, either the first antenna or the second antenna based on setting information that defines a relationship between the distribution request area indicated in the distribution request area information and an antenna to be selected; a transmitting unit that transmits the message received by the receiving unit using the selected antenna; A message relay device comprising: and an in-vehicle device including means for transmitting the message including the distribution request area information and addressed to another mobile unit.

7. a first antenna pointing in a first direction; a second antenna oriented in a second direction different from the first direction; receiving a message including distribution request area information from one mobile unit and addressed to another mobile unit; selecting, for each antenna that has received the message, either the first antenna or the second antenna based on setting information that defines a relationship between the distribution request area indicated in the distribution request area information and the antenna to be selected; A message relay method for transmitting the received message using the selected antenna.

8. a first antenna pointing in a first direction; a second antenna that is oriented in a second direction different from the first direction; and a vehicle-mounted device connected to the message relay device, Transmitting a message including distribution request area information to the message relay device and addressed to another mobile unit; A message relay method which causes the message relay device to select either the first antenna or the second antenna for each antenna that has received the message, based on setting information that defines a relationship between the delivery request area indicated in the delivery request area information and the antenna to be selected, and transmits the received message using the selected antenna.

9. a first antenna pointing in a first direction; a second antenna pointing to a second direction different from the first direction; and A process of receiving a message including delivery request area information from one mobile unit and addressed to another mobile unit; a process of selecting either the first antenna or the second antenna for each antenna that has received the message, based on setting information that defines a relationship between the distribution request area indicated in the distribution request area information and the antenna to be selected; and transmitting the received message using the selected antenna.

10. a first antenna pointing in a first direction; a second antenna pointing in a second direction different from the first direction; and a computer mounted on an in-vehicle device connected to the message relay device, A process of transmitting a message including delivery request area information to the message relay device and addressed to another mobile unit; a process of causing the message relay device to select either the first antenna or the second antenna for each antenna that has received the message, based on setting information that defines a relationship between the delivery request area indicated in the delivery request area information and the antenna to be selected, and causing the message relay device to transmit the received message using the selected antenna; A program that executes the following.

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