Communication device and communication method

Abstract

To provide a communication device capable of easily establishing wireless links among vehicles entering an intersection in wireless communication between vehicles, and a communication method.SOLUTION: A communication device 100 mounted on a vehicle includes: a first communication circuit that functions as an access point in an infrastructure mode and transmits radio waves forward of the vehicle and receives the radio waves; and a second communication circuit that functions as a station in the infrastructure mode and transmits radio waves forward of the vehicle and receives the radio waves.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a communication device and a communication method. [Background technology]

[0002] Patent Document 1 discloses a method in which a wireless communication device mounted on an automobile switches between a plurality of modes, such as a station (STA) mode and an access point (AP) mode, to perform mutual communication.

[0003] Non-Patent Document 1 specifies PBSS (Personal Basic Service Set) as a method for terminals to communicate with each other without going through a base station. In PBSS, a PCP (PBSS Control Point), which is responsible for determining scheduling, is selected from one or more nearby terminals that can communicate.

[0004] Incidentally, traffic accidents are likely to occur at intersections, etc. Therefore, if vehicles entering an intersection could communicate with each other information, such as camera images, safety at the intersection could be improved in some cases. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2016 / 009481 [Non-patent literature]

[0006] [Non-Patent Document 1] IEEE802.11-2016 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in vehicle-to-vehicle communication based on PBSS, it is sometimes difficult to establish a wireless link between vehicles entering an intersection.

[0008] Non-limiting embodiments of the present disclosure contribute to providing a communication device and a communication method that can facilitate the establishment of a wireless link between vehicles entering an intersection. [Means for solving the problem]

[0009] A communication device according to one embodiment of the present disclosure is a communication device mounted on a vehicle, and has a first communication circuit that operates as an access point in infrastructure mode and transmits and receives radio waves toward the front of the vehicle, and a second communication circuit that operates as a station in infrastructure mode and transmits and receives radio waves toward the front of the vehicle.

[0010] A communication method according to one embodiment of the present disclosure is a communication method for a communication device mounted on a vehicle, in which a first communication circuit operates as an access point in infrastructure mode, the first communication circuit transmitting and receiving radio waves toward the front of the vehicle, and a second communication circuit operates as a station in infrastructure mode, the second communication circuit transmitting and receiving radio waves toward the front of the vehicle.

[0011] In addition, these comprehensive or specific aspects may be realized by a system, an apparatus, a method, an integrated circuit, a computer program, or a recording medium, or may be realized by any combination of a system, an apparatus, a method, an integrated circuit, a computer program, and a recording medium. Effect of the Invention

[0012] According to one embodiment of the present disclosure, it is possible to facilitate the establishment of a wireless link between vehicles entering an intersection.

[0013] Further advantages and benefits of an embodiment of the present disclosure will become apparent from the specification and drawings, in which such advantages and / or benefits are provided by some of the embodiments and features described in the specification and drawings, respectively, but not necessarily all of which are provided to obtain one or more identical features. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram illustrating an example of inter-vehicle communication using the PBSS mode. [Diagram 2] FIG. 1 is a diagram illustrating another example of inter-vehicle communication using the PBSS mode. [Diagram 3] FIG. 1 is a block diagram illustrating an example of a configuration of a communication device according to a first embodiment; [Figure 4] FIG. 1 is a diagram for explaining an example of antenna directivity; [Diagram 5] FIG. 1 is a diagram for explaining an example of inter-vehicle communication according to a first embodiment; [Figure 6] FIG. 1 is a diagram for explaining another example of inter-vehicle communication according to the first embodiment; [Figure 7] FIG. 1 is a diagram for explaining another example of inter-vehicle communication according to the first embodiment; [Figure 8] 1 is a flowchart showing an example of an operation of inter-vehicle communication according to a first embodiment. [Figure 9] FIG. 13 is a diagram showing another example of a block configuration of a communication device. [Figure 10A] 11 is a flowchart showing an example of an operation of inter-vehicle communication according to a second embodiment. [Figure 10B] 11 is a flowchart showing an example of an operation of inter-vehicle communication according to a second embodiment. [Figure 11] FIG. 1 is a diagram for explaining an example of a probe response frame. [Figure 12] FIG. 13 is a block diagram illustrating an example of a configuration of a communication device according to a third embodiment. [Figure 13] FIG. 1 is a diagram for explaining an example of antenna directivity; [Figure 14] FIG. 13 is a diagram for explaining an example of inter-vehicle communication according to a third embodiment; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the drawings as appropriate. However, more detailed explanation than necessary may be omitted. For example, detailed explanation of already well-known matters or duplicate explanation of substantially the same configuration may be omitted. This is to avoid the following explanation becoming unnecessarily redundant and to facilitate understanding by those skilled in the art.

[0016] It should be noted that the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0017] (First embodiment) Fig. 1 is a diagram for explaining an example of inter-vehicle communication using the PBSS mode. Fig. 1 shows vehicles 10A, 10B, 10C, and 10D. The vehicles 10A, 10B, 10C, and 10D may be vehicles that run on or near roads, such as automobiles, motorcycles, bicycles, or streetcars. Note that the following drawings will be described using an example of left-hand traffic, but the same can be applied to right-hand traffic.

[0018] The vehicle 10A is equipped with a communication device 1000a. The vehicle 10B is equipped with a communication device 1000b. The vehicle 10C is equipped with a communication device 1000c. The vehicle 10D is equipped with a communication device 1000d.

[0019] The communication devices 1000a to 1000d perform communication based on the PBSS mode. Hereinafter, communication performed between vehicles traveling side by side in the same traveling direction may be referred to as inter-vehicle communication.

[0020] The vehicle 10A and the vehicle 10B travel in the same direction on a road, for example. The communication device 1000a and the communication device 1000b perform inter-vehicle communication.

[0021] For example, communication device 1000a discovers (detects) communication device 1000b and establishes (connects) a wireless link with communication device 1000b based on the PBSS. Communication device 1000a and communication device 1000b determine one of the communication devices to be a PCP based on the method described in Non-Patent Document 1. As an example, communication device 1000a and communication device 1000b determine communication device 1000b to be a PCP and communication device 1000a to be a non-PCP. In this case, communication device 1000a, which is a non-PCP, is said to participate in the PBSS of communication device 1000b, which is a PCP.

[0022] The vehicle 10C and the vehicle 10D travel in the same direction on a road, for example. The communication device 1000c and the communication device 1000d perform inter-vehicle communication.

[0023] For example, the communication device 1000c discovers the communication device 1000d and establishes a wireless link with the communication device 1000d based on the PBSS. The communication devices 1000c and 1000d determine one of the communication devices as a PCP based on the method described in Non-Patent Document 1. As an example, the communication devices 1000c and 1000d determine the communication device 1000c as a PCP and the communication device 1000d as a non-PCP. In this case, the non-PCP communication device 1000d is said to participate in the PBSS of the PCP communication device 1000c.

[0024] Here, at places where vehicles cross paths, such as intersections, safety may be improved by performing inter-vehicle communication between vehicles that meet. For example, by transmitting an image from a camera (not shown) mounted on vehicle 10C from communication device 1000c to communication device 1000a, vehicle 10A can find a pedestrian (not shown) ahead of the right turn when making a right turn, and safety during the right turn may be improved.

[0025] As an example of establishing communication at an intersection, a communication device 1000a of a vehicle 10A entering the intersection discovers a communication device 1000c of a vehicle 10C entering the intersection. In order to start communication with the discovered communication device 1000c, the communication device 1000a leaves (disconnects) the PBSS of the communication device 1000b and joins the PBSS of the communication device 1000c.

[0026] As a result, the communication device 1000a of the vehicle 10A can communicate with the communication device 1000c of the vehicle 10C that it encounters at the intersection and receive video from the camera mounted on the vehicle 10C. Also, the communication device 1000d of the non-PCP that is performing inter-vehicle communication with the communication device 1000c of the PCP can communicate with the communication device 1000a by sending a relay request to the communication device 1000c.

[0027] However, since the communication device 1000a has left the PBSS of the communication device 1000b, the communication device 1000a is not performing inter-vehicle communication with the communication device 1000b. This may make it difficult for the vehicle 10A to detect a vehicle approaching from behind, for example, and may reduce safety.

[0028] For example, if a camera (not shown) mounted on vehicle 10B detects a two-wheeled vehicle 10H approaching from behind, communication device 1000b does not need to transmit the camera's image of two-wheeled vehicle 10H to communication device 1000a, thereby reducing safety when vehicle 10A turns right.

[0029] Furthermore, before establishing a wireless link with communication device 1000c, communication device 1000a interrupts communication with communication device 1000b, and after leaving the PBSS, communication device 1000c executes a procedure for joining the PBSS. This may result in a delay in starting transmission of the camera image of vehicle 10C to communication device 1000a, which may reduce safety when vehicle 10A turns right.

[0030] Fig. 2 is a diagram for explaining another example of inter-vehicle communication using the PBSS mode, in which the same components as those in Fig. 1 are denoted by the same reference numerals.

[0031] For example, the vehicle 10A and the vehicle 10B travel in the same direction on a road. The communication device 1000a and the communication device 1000b establish a wireless link based on the PBSS and perform communication between the vehicle trains. For example, the communication device 1000a determines a non-PCP, and the communication device 1000b determines a PCP.

[0032] For example, the vehicle 10C and the vehicle 10D travel in the same direction on a road. The communication device 1000c and the communication device 1000d establish a wireless link based on the PBSS and perform inter-vehicle communication. For example, the communication device 1000c determines a PCP, and the communication device 1000d determines a non-PCP.

[0033] Here, when vehicle 10D enters the intersection and turns right after vehicle 10C has passed the intersection, two-wheeled vehicle 10G in the oncoming lane is hidden behind vehicle 10E and is positioned in the blind spot of the driver of vehicle 10D.

[0034] On the other hand, a sensor (not shown) such as a radar or a camera mounted on the vehicle 10B can detect the two-wheeled vehicle 10G. If the communication device 1000b can notify the communication device 1000d of the vehicle 10D of information about the two-wheeled vehicle 10G detected by the sensor of the vehicle 10B, safety when the vehicle 10D makes a right turn can be improved.

[0035] However, since the communication device 1000d participates in the PBSS of the communication device 1000c, it takes time to establish a wireless link with the communication device 1000b. For example, the communication device 1000d interrupts communication with the communication device 1000c, leaves the PBSS of the communication device 1000c, and then executes a procedure for joining the PBSS in the communication device 1000b, so it takes time to establish a wireless link with the communication device 1000b. If it takes time to establish a wireless link, the vehicle 10D may be late in discovering a vehicle, such as the motorcycle 10G approaching from the front, which may reduce safety.

[0036] A communication device according to the present disclosure facilitates wireless communication between vehicles, for example, by establishing a wireless link between vehicles at a location such as an intersection.

[0037] 3 is a diagram showing an example of a block configuration of a communication device 100 according to the first embodiment. As shown in FIG. 3, the communication device 100 includes an AP radio device 101, a non-AP radio device 102, a non-AP radio device 103, control devices 104 and 105, a connection circuit 106, and antennas 111, 112, and 113.

[0038] The antennas 111 and 112 change their directivity in a certain range in front of the vehicle. The antenna 113 changes its directivity in a certain range in the rear of the vehicle. The antennas 111, 112, and 113 may be array antennas or phased array antennas having a plurality of antenna elements.

[0039] AP radio 101, non-AP radio 102, and AP radio 103 operate in infrastructure mode conforming to the IEEE 802.11 series of standards, which may also be referred to as infrastructure BSS mode.

[0040] The AP radio 101 operates based on the AP mode. The AP radio 101 is connected to an antenna 111 and communicates within a certain range in front of the vehicle. The AP radio 101 communicates using, for example, millimeter waves.

[0041] The non-AP radio 102 operates based on a non-AP mode. The non-AP radio 102 is connected to an antenna 112 and communicates in a certain range in front of the vehicle. The non-AP radio 102 communicates using, for example, millimeter waves.

[0042] The non-AP radio 103 operates based on the non-AP mode. The non-AP radio 103 is connected to an antenna 113 and communicates within a certain range behind the vehicle. The non-AP radio 103 communicates using, for example, millimeter waves.

[0043] The AP may be called a base station or a parent device, and the non-AP may be called a STA, a terminal, a client, or a child device.

[0044] The AP radio 101 and the non-AP radio 102 may be physically separate. Also, the AP radio 101 and the non-AP radio 102 may be physically one radio, and one radio may have the functions of the AP radio 101 and the non-AP radio 102.

[0045] The non-AP radios 102, 103 may be physically separate. Also, the non-AP radios 102, 103 may be physically one radio, and one radio may have the functions of the non-AP radios 102, 103.

[0046] The control devices 104 and 105 perform routing control between subnets (BSSs) in which the AP radio 101, the non-AP radio 102, and the non-AP radio 103 participate. The control device 104 also determines the network address of the BSS that the AP radio 101 provides services to. The control devices 104 and 105 may be configured with a processor such as a CPU (Central Processing Unit) or a DSP (Digital Signal Processor), for example.

[0047] The control device 104 is connected to the AP radio 101 and the non-AP radio 102 via an interface such as a Universal Serial Bus (USB), a Peripheral Component Interconnect Express (PCIe), or an Ethernet. The control device 105 is connected to the non-AP radio 103 via an interface such as a USB, a PCIe, or an Ethernet.

[0048] The control devices 104 and 105 are connected to a connection circuit 106 via an interface such as Ethernet or a CAN (Controller Area Network). The connection circuit 106 connects the control devices 104 and 105. The connection circuit 106 may be a device or circuit such as a hub, a switch, a router, a wire harness, or a switch box. The connection circuit 106 may also be an access point, a slave unit, a USB dongle, or an expansion board based on a wireless communication method such as a wireless LAN (Local Area Network), WiGig (Wireless Gigabit), or Bluetooth.

[0049] A position detection device 200 that detects the position of a vehicle equipped with the communication device 100 is connected to the communication device 100. The position detection device 200 may detect the position of the vehicle using, for example, a navigation system that uses a Global Navigation Satellite System (GNSS). The position detection device 200 may be incorporated in the communication device 100. Furthermore, the communication device 100 may be carried by a pedestrian (not shown).

[0050] 4 is a diagram illustrating an example of the directivity of antennas 111, 112, and 113. Antennas 111 and 112 that radiate radio waves ahead of the vehicle may have, as an example, a directivity with a half-value angle of 5°, as shown in sector 201. Antennas 111 and 112 may change the direction of directivity (beam or sector) within a range of 120° in front of the vehicle (60° to the left and 60° to the right of the front of the vehicle), as shown in sector 202.

[0051] Antenna 113 that radiates radio waves to the rear of the vehicle may have directivity with a half-power angle of 5°, as shown in sector 203, for example. Antenna 113 may change the direction of directivity within a range of 120° to the rear of the vehicle (60° to the left and 60° to the right of the rear front of the vehicle), as shown in sector 204, for example.

[0052] It should be noted that the movable range of the directivity direction shown in the sectors 202 and 204 is not limited to 120°. The movable range of the directivity direction may be 90° or 180°. In millimeter wave communication, a large number of antenna elements are arranged on a substrate or module to form a small, highly directional array antenna. For this reason, the communication range of one antenna module is often within 180°.

[0053] 5 is a diagram illustrating an example of inter-vehicle communication according to the first embodiment. Vehicles 10A, 10B, 10C, and 10D shown in FIG. 5 are equipped with the communication device 100 shown in FIG.

[0054] In the following, in order to distinguish between the communication devices 100 installed in the vehicles 10A, 10B, 10C, and 10D, the communication device installed in the vehicle 10A may be referred to as communication device 100a, the communication device installed in the vehicle 10B as communication device 100b, the communication device installed in the vehicle 10C as communication device 100c, and the communication device installed in the vehicle 10D as communication device 100d.

[0055] In addition, in order to distinguish between the units of the communication devices 100a, 100b, 100c, and 100d, the reference numerals of the units of the communication devices 100a, 100b, 100c, and 100d may be appended with a, b, c, or d. For example, the AP radio 101 of the communication device 100a may be referred to as AP radio 101a. The AP radio 101 of the communication device 100b may be referred to as AP radio 101b.

[0056] As an example, the vehicle 10A and the vehicle 10B travel in the same direction on a road. The non-AP wireless device 103a of the vehicle 10A connects (establishes a wireless link) to the AP wireless device 101b of the following vehicle 10B to perform communication between the vehicle trains. For example, the non-AP wireless device 103a of the vehicle 10A and the AP wireless device 101b of the vehicle 10B use a distribution service described in Non-Patent Document 1 to perform AP-non-AP communication. As a result, the communication device 100a of the vehicle 10A and the communication device 100b of the vehicle 10B perform data communication based on, for example, the Internet Protocol (IP).

[0057] Note that the communication device 100 does not communicate with a combination of non-AP radio devices. In other words, the communication device 100 does not communicate between terminals (between the non-AP radio device 102 and the non-AP radio device 103).

[0058] Also, the AP radio 101 transmits a beacon frame, and the non-AP radio 103 does not transmit a beacon frame. This allows the communication device 100 to reduce the total number of beacon frames, and improve the throughput of data communication due to interference between communication devices and occupation of wireless bands. The beacon frame may be called a beacon signal.

[0059] Also, the AP radio 101 may provide the service of one BSS and set up one subnet (a unit of a local area network in IP communication).

[0060] The control device 104 may also have a server function of DHCP (Dynamic Host Configuration Protocol). For example, when the non-AP radio device 103 connects to the AP radio device 101, the control device 104 may assign one of the IP addresses belonging to the subnet of the AP radio device 101 to the non-AP radio device 103.

[0061] For example, the vehicle 10C and the vehicle 10D travel in the same direction on a road. The non-AP radio 103c of the vehicle 10C and the AP radio 101d of the following vehicle 10D also perform inter-vehicle communication in the same manner as the non-AP radio 103a of the vehicle 10A and the AP radio 101b of the following vehicle 10B described above.

[0062] Here, the non-AP radio 102d of the vehicle 10D enters the intersection while scanning for beacon frames. The non-AP radio 102d of the vehicle 10D finds the AP radio 101b of the vehicle 10B, which is an AP, and connects to the AP radio 101b. Note that the AP radio 101b of the vehicle 10B can establish wireless links with multiple non-APs (the non-AP radio 103a of the vehicle 10A and the non-AP radio 102d of the vehicle 10D).

[0063] This allows the communication device 100d of the vehicle 10D to communicate with the communication device 100b of the vehicle 10B via the non-AP radio 102d without disconnecting the wireless link with the communication device 100c of the vehicle 10C (without disconnecting the inter-vehicle communication). Also, the communication device 100d of the vehicle 10D can communicate with the communication device 100a of the vehicle 10A via the communication device 100b (AP radio 101b) of the vehicle 10B.

[0064] The control device 104d of the vehicle 10D may operate as a router. For example, the control device 104d of the vehicle 10D may perform routing between the subnetwork corresponding to the BSS of the AP radio 101d and the subnetwork corresponding to the BSS of the radio 101b of the vehicle 10B to which the non-AP radio 102d is connected.

[0065] As a result, the communication device 100c of the vehicle 10C can communicate with the communication device 100b of the vehicle 10B via the communication device 100d (router) of the vehicle 10D. Furthermore, the communication device 100c of the vehicle 10C can communicate with the communication device 100a of the vehicle 10A via the communication device 100b of the vehicle 10B. In other words, the communication device 100c of the vehicle 10C can be connected to a network for inter-vehicle communication separate from the inter-vehicle communication with the communication device 100d of the following vehicle 10D.

[0066] The control device 104 may determine a communication path (routing path) by using a routing protocol such as RIP (Routing Information Protocol), OSPF (Open Shortest Path First), or BGP (Border Gateway Protocol).

[0067] Controller 104 may also perform routing between AP radio 101 and non-AP radio 103. Controller 104 may also perform routing between non-AP radio 102 and non-AP radio 103.

[0068] Furthermore, the communication device 100 may configure a mesh network using an existing routing protocol in infrastructure mode.

[0069] Furthermore, the control device 104 may randomly set the network address of the subnet used by the AP radio device 101. As an example, the control device 104 may randomly select one network address from network addresses 10.0.0.0 / 28, 10.0.0.16 / 28, 10.0.0.32 / 28, . . ., 10.0.0.240 / 28, 10.0.1.0 / 28, . . ., 10.0.0.240 / 28, . . ., 10.0.255.0 / 28, 10.1.0.0 / 28, . . ., 10.255.0.0 / 28, . . ., 10.255.255.0 / 28, . . ., 10.255.255.240 / 28 (256x256x16 combinations).

[0070] This reduces the probability that the network address of the subnetwork of the AP radio 101 will overlap with the network address of the subnetwork connected to the non-AP radios 102 and 103. It also reduces the probability that the network address of the subnetwork of the AP radio 101 will overlap with the network address of the subnetwork connected to the non-AP radios 102 and 103 by routing of the control device 104 of another vehicle. Through routing between the AP radio 101, non-AP radio 102, and non-AP radio 103 mounted on the vehicle 10, communication between a large number of vehicles becomes possible.

[0071] Furthermore, the control device 104 may perform bridging instead of routing when the network addresses of the AP radio 101 and the non-AP radio devices 102 and 103 overlap. When the network addresses of the AP radio device 101 and the non-AP radio devices 102 and 103 overlap and the subnet masks are different, the control device 104 may connect the subnets based on Proxy ARP (ARP: Address Resolution Protocol). The control device 104 may select any one of routing, bridging, or Proxy ARP depending on whether the network addresses of the AP radio device 101 (AP) and the non-AP radio devices 102 and 103 overlap or whether the subnet masks match.

[0072] The control device 104 may also use an IPv6 (IP version 6) site local address and set a subnet for each BSS. The control device 104 may also use a unique IPv6 network address that is predefined for each AP radio 101.

[0073] Furthermore, when the non-AP radio 102 of the first vehicle connects to the AP radio 101 of the second vehicle, the non-AP radio 102 of the first vehicle may notify the AP radio 101 of the second vehicle of information such as the BSSID (BSS IDentifier), MAC address, or SSID (Service Set Identifier) ​​of the AP radio 101 of the first vehicle. The non-AP radio 102 of the second vehicle may obtain information about the AP radio 101 of the first vehicle from the AP radio 101 of the second vehicle, and exclude the AP radio 101 of the first vehicle from connections.

[0074] 5, for example, the non-AP radio 102d of vehicle 10D connects to the AP radio 101b of vehicle 10B. The non-AP radio 101d of vehicle 10D notifies the AP radio 101b of vehicle 10B of the SSID of the AP radio 101d of vehicle 10D. The non-AP radio 102b of vehicle 10B excludes the SSID of the AP radio 101d of vehicle 10D received by the AP radio 101b from the scanning targets and association targets. The non-AP radio 102b of vehicle 10B may also exclude the BSSID of the AP radio 101d of vehicle 10D from the scanning targets and association targets.

[0075] Fig. 6 is a diagram for explaining another example of inter-vehicle communication according to the first embodiment. In Fig. 6, the same components as in Fig. 5 are denoted by the same reference numerals.

[0076] In FIG. 6, roadside units 400a, 400b, 400c, and 400d are installed at an intersection. The roadside units 400a, 400b, 400c, and 400d are APs that operate based on the infrastructure mode. The roadside units 400a, 400b, 400c, and 400d are connected to each other by a backhaul line (not shown), and relay communication between non-AP wireless units by relay, bridge, or routing. The backhaul line may be configured by a wired or wireless line. Hereinafter, when the roadside units 400a, 400b, 400c, and 400d are not to be distinguished from each other, they may be referred to as the roadside unit 400.

[0077] When the non-AP wireless devices 102a, 102b, 102c, and 102d are connected to the roadside devices 400a, 400b, 400c, and 400d, mutual communication becomes possible between the non-AP wireless devices 102a, 102b, 102c, and 102d.

[0078] As an example, a non-AP wireless device 102b of a vehicle 10B entering an intersection and a non-AP wireless device 102d of a vehicle 10D entering the intersection connect to the roadside unit 400. The non-AP wireless device 102b of the vehicle 10B and the non-AP wireless device 102d of the vehicle 10D communicate with each other via the roadside unit 400.

[0079] The non-AP radio 102 of the communication device 100 may start scanning the AP radio 101 when the vehicle enters an intersection and is not connected to the roadside device 400. That is, when the vehicle enters an intersection and the communication device 100 has established a wireless link with the roadside device 400, the non-AP radio 102 may not execute the wireless link establishment process described in Fig. 5. In other words, the non-AP radio 102 may prioritize establishment of a wireless link with the roadside device over establishment of a wireless link with the AP radio of the vehicle.

[0080] When the non-AP radio 102x (not shown) of the following vehicle X (not shown) of the vehicle 10B does not connect to the roadside unit 400 (for example, when the non-AP radio 102x is out of range of the roadside unit 400), the non-AP radio 103b of the vehicle 10B may connect to the AP radio 101 of the following vehicle X. Then, the non-AP radios 102b, 103b of the vehicle 10B may perform routing.

[0081] As a result, even if the non-AP wireless device 102x of the following vehicle X of the vehicle 10B is outside the wireless communication range of the roadside unit 400, the non-AP wireless device 102x can communicate with the roadside unit 400 via the communication device 100b of the vehicle 10B. That is, the communication device 100b of the vehicle 10B expands the communication area of ​​the roadside unit 400.

[0082] Fig. 7 is a diagram for explaining another example of inter-vehicle communication according to the first embodiment. In Fig. 7, the same components as those in Fig. 5 are denoted by the same reference numerals. In Fig. 7, vehicle 10C is traveling in the opposite lane to the lane in which vehicles 10A and 10B are traveling.

[0083] It is assumed that the non-AP radio 103a of the vehicle 10A is communicating with the AP radio 101b of the following vehicle 10B in a convoy. It is assumed that the non-AP radio 102b of the vehicle 10B is communicating with the AP radio 101c of the vehicle 10C traveling in the oncoming lane. It is assumed that the non-AP radio 102c of the vehicle 10C has not established a wireless link with the AP radio 101 of another vehicle 10. It is assumed that the AP radio 101d and the non-AP radio 102d of the vehicle 10D have not established a wireless link with the AP radio 101 and the non-AP radio 103 of another vehicle 10.

[0084] If the non-AP radio 102 has established a wireless link with the AP radio 101 of the other vehicle 10 before the vehicle 10 enters the intersection, the non-AP radio 102 may disconnect the wireless link with the AP radio 101 of the other vehicle 10.

[0085] 7, the non-AP radio 102b of the vehicle 10B establishes a wireless link with the AP radio 101c of the vehicle 10C traveling in the oncoming lane. The non-AP radio 102b of the vehicle 10B may disconnect the wireless link with the AP radio 101c of the vehicle 10C before entering the intersection.

[0086] The non-AP radio 102b of vehicle 10B, which has disconnected its wireless link with the AP radio 101c of vehicle 10C, starts scanning for beacon frames. Based on the scanning of beacon frames, the non-AP radio 102b of vehicle 10B discovers the AP radio 101c of vehicle 10C and the AP radio 101d of vehicle 10D.

[0087] The non-AP radio 102b of the vehicle 10B establishes a wireless link with the AP radio 101 having the better wireless quality of the beacon frame from among the discovered AP radios 101c and 101d. The wireless quality may be a received signal strength indicator (RSSI).

[0088] Here, vehicle 10C is an oncoming vehicle of vehicle 10B and travels in the opposite direction to vehicle 10B. Vehicle 10D travels laterally to the traveling direction of vehicle 10B. Therefore, the relative speed between vehicle 10B and vehicle 10C is greater than the relative speed between vehicle 10B and vehicle 10D, and the wireless quality of AP radio 101d of vehicle 10D is better than the wireless quality of AP radio 101c of vehicle 10C. Therefore, non-AP radio 102b of vehicle 10B establishes a wireless link with AP radio 101d of vehicle 10D out of AP radios 101c and 101d that it has discovered.

[0089] That is, the non-AP radio 102b of the vehicle 10B establishes a wireless link with the AP radio 101d of the vehicle 10D that meets it head-on (meets for the first time) at the intersection. In other words, the non-AP radio 102b of the vehicle 10B cuts off the wireless link with the AP radio 101c of the vehicle 10C traveling in the oncoming lane, and prioritizes the establishment of a wireless link with the AP radio 101d of the vehicle 10D that enters the intersection from a road other than the road on which the vehicle 10B is traveling.

[0090] The non-AP radio 102c of vehicle 10C, which has not established a wireless link, discovers the AP radio 101b of vehicle 10B and the AP radio 101d of vehicle 10D. The non-AP radio 102d of vehicle 10D, which has not established a wireless link, discovers the AP radio 101b of vehicle 10B and the AP radio 101c of vehicle 10C.

[0091] The non-AP radio 102d of vehicle 10D may connect to the AP radio 101c of vehicle 10C out of the AP radio 101b of vehicle 10B and the AP radio 101c of vehicle 10C that it has discovered. This is because a wireless link has been established between the non-AP radio 102b of vehicle 10B and the AP radio 101d of vehicle 10D. The non-AP radio 102d of vehicle 10D may notify the AP radio 101c of vehicle 10C with which it has established a wireless link of the BSSID of the AP radio 101d.

[0092] When the non-AP radio 102c of the vehicle 10C acquires the BSSI of the AP radio 101d of the vehicle 10D, it may connect to the AP radio 101b of the vehicle 10B without connecting to the AP radio 101d of the vehicle 10D.

[0093] Furthermore, when the non-AP radio 102c of the vehicle 10C can communicate with the communication device 100b of the vehicle 10B by the routing of the communication device 100d of the vehicle 10D, the non-AP radio 102c of the vehicle 10C does not need to be connected to the AP radio 101b of the vehicle 10B. The non-AP radio 102c of the vehicle 10C may be connected to an AP radio (not shown) of a preceding vehicle traveling in front of the vehicle 10C.

[0094] Fig. 8 is a flowchart showing an operation example of inter-vehicle communication according to the first embodiment. In Fig. 8, an operation example of a communication device 100b mounted on a vehicle 10B will be described. The communication device 100b periodically executes, for example, the process of the flowchart shown in Fig. 8.

[0095] The control device 104b detects (scheduled to) the vehicle 10B entering an intersection based on the position detection by the position detection device 200b (S1001). For example, the control device 104b detects that the vehicle 10B has entered a predetermined area including the intersection (for example, a circle with a radius of 50 m centered on the intersection) based on the current position of the vehicle 10B detected by the position detection device 200b and map information.

[0096] The control device 104b may detect the entry of the vehicle 10B into an intersection using the ON of a direction indicator as a trigger.

[0097] The control device 104b determines whether the connection destination of the non-AP radio device 102b is the roadside device 400 (S1002). When the control device 104b determines that the connection destination of the non-AP radio device 102b is the roadside device 400 ("Yes" in S1002), the control device 104b shifts the process to S1009.

[0098] When the control device 104b determines that the non-AP wireless device 102b is not connected to the roadside device 400 ("No" in S1002), the control device 104b controls the non-AP wireless device 102b to start scanning for beacon frames (S1003).

[0099] In addition, if the non-AP radio 102b is connected to the AP radio 101 of the other vehicle 10 before starting the scan of the beacon frame in S1003, the control device 104b may disconnect the communication with the AP radio 101 of the other vehicle 10. In other words, the control device 104b may temporarily put the non-AP radio 102b, which is in front of the vehicle 10B and wirelessly communicates with the AP radio 101 of the other vehicle 10, into a free state (a state in which it is not connected to the AP radio 101). This allows the non-AP radio 102b of the vehicle 10B to disconnect the connection with the AP radio 101c of the vehicle 10C traveling in the oncoming lane, for example, and connect to the AP radio 101c of the vehicle 10C (the vehicle 10C that meets at the intersection) that enters from a road different from the road on which the vehicle 10B is traveling.

[0100] The control device 104b judges whether or not the AP radio 101 of another vehicle 10 has been detected based on the start of scanning for beacon frames in S1003 (S1004).

[0101] If the control device 104b does not detect the AP radio 101 of the other vehicle 10 ("No" in S1004), the control device 104b shifts the process to S1003.

[0102] When the control device 104b detects the AP radio 101 of another vehicle 10 ("Yes" in S1004), it selects the AP radio 101 to connect to (S1005). For example, the control device 104b selects the AP radio 101 with the best wireless quality of the beacon frame.

[0103] The control device 104b associates with the AP wireless device 101 selected in S1005 and determines an IP address (S1006).

[0104] The control device 104b transmits the BSSID of the AP radio 101b to the AP radio 101 associated in S1006 via the non-AP radio 102b (S1007). When communicating based on IPv4, the control device 104b may determine the IP address based on DHCP. When communicating based on IPv6, the control device 104b may determine the IP address based on SLAAC (StateLess Address Auto Configuration) or DHCPv6.

[0105] The control device 104b sets up routing between the AP radio 101b and the non-AP radio 102b, and transmits the set routing information via the AP radio 101b (S1008).

[0106] The control device 104b notifies the connected network of the IP address of the network with which the wireless link is established via the AP wireless device 101b (S1009).

[0107] In the processes of S1008 and S1009, the control device 104b may discover the AP radio 101 of another vehicle 10 by using, for example, mDNS (multicast Domain Name System) or Bonjour.

[0108] The control device 104b may also use mDNS or Bonjour to notify the IP address and service information. The service information may include application information such as collision avoidance information, route information, dynamic map, and Internet connection gateway. The service information may also include protocol information such as MQTT (Message Queuing Telemetry Transport), WebSocket, or ROS (Robot OS) message.

[0109] The control device 104b receives IP address information of the communication devices 100 of the other vehicles 10 via the AP radio 101b and the non-AP radio 102b (S1010).

[0110] The control device 104b determines the destination IP address of the data and performs data communication via the AP radio device 101b and the non-AP radio devices 102b and 103b (S1011). The control device 104b may broadcast or multicast the data to the subnetwork for which the route has been set.

[0111] As described above, communication device 100 has AP radio 101 and antenna 111 that operate as an AP in infrastructure mode and transmit and receive radio waves toward the front of vehicle 10, and non-AP radio 102 and antenna 112 that operate as a station in infrastructure mode and transmit and receive radio waves toward the front of vehicle 10. This enables communication device 100 to easily establish a wireless link at a location such as an intersection where roads intersect.

[0112] For example, the communication device 100 can maintain inter-vehicle communication with the communication device of the vehicle 10 traveling ahead by the AP radio 101, and can further establish communication with the communication device of the vehicle entering the intersection by the non-AP radio 102. That is, the communication device 100 can easily establish communication with the communication device of the vehicle entering the intersection by the non-AP radio 102, without disconnecting the inter-vehicle communication of the AP radio 101.

[0113] In addition, the control device 104 controls the non-AP radio 102 to select the AP radio 101 with good wireless quality (the AP radio 101 of the vehicle with a slow relative speed). Since the wireless link with the vehicle 10 with a slow relative speed has a low risk of being disconnected early, the communication device 100 can perform a large amount of data communication.

[0114] Furthermore, since communication device 100 includes two radio devices, AP radio device 101 and non-AP radio device 102, which communicate in front of vehicle 10, communication device 100 can perform low-latency inter-vehicle communication.

[0115] Furthermore, the communication device 100 can form a mesh network using directional millimeter wave communication, even in a mobility environment where the position and direction of the vehicle 10 changes from moment to moment, and can communicate with a large number of vehicles.

[0116] The position detection device 200 may detect the entry of the vehicle into an intersection using an ADAS. The ADAS may detect the entry of the vehicle 10 into an intersection using at least one sensor such as a camera, a LiDAR (Light Detection and Ranging, Laser Imaging Detection and Ranging), or a radar.

[0117] 8, when the control device 104 detects an entry into an intersection, the control device 104 executes the process of S1002, but the present invention is not limited to this. The control device 104 may also execute the process of S1002 when a blind spot exists within a predetermined angle (e.g., 120°) in front of the vehicle 10 based on an ADAS (Advanced driver-assistance systems). The blind spot in front of the vehicle may be detected by a sensor such as a camera, LiDAR, or radar.

[0118] Furthermore, communication device 100 may transmit the list of network addresses or the routing information using a wireless scheme different from the wireless schemes used by AP radio 101 and non-AP radio devices 102 and 103. For example, communication device 100 may transmit the list of network addresses or the routing information using a wireless scheme such as Dedicated Short Range Communications (DSRC), Long Term Evolution (LTE)-Vehicle-to-Everything (V2X), or Wi-Fi (registered trademark).

[0119] 3 includes two control devices 104 and 105 and a connection circuit 106, but the present invention is not limited to this. The communication device 100 may include one control device.

[0120] Fig. 9 is a diagram showing another example of a block configuration of the communication device 100. In Fig. 9, the same components as in Fig. 3 are denoted by the same reference numerals. As shown in Fig. 9, the communication device 100 has one control device 114.

[0121] The control device 114 controls routing between subnets (BSSs) in which the AP radio 101, the non-AP radio 102, and the non-AP radio 103 participate. The control device 114 also determines the network address of the BSS that the AP radio 101 provides service to. The control device 114 may be configured by a processor such as a CPU or a DSP.

[0122] (Second embodiment) In the first embodiment, when the control device 104 detects an AP radio 101 of another vehicle 10, it selects the AP radio 101 with the best wireless quality. In the second embodiment, the control device 104 selects the AP radio 101 with the largest increase in the number of subnetworks with which it can communicate. In other words, the control device 104 excludes AP radios 101 that are already reachable by routing from the selection candidates. The following describes the differences from the first embodiment.

[0123] 10A and 10B are flowcharts showing an operation example of inter-vehicle communication according to the second embodiment. A and B circled in FIG. 10A are connected to A and B circled in FIG. 10B. In FIG. 10A and 10B, the same processes as those described in FIG. 8 are denoted by the same reference numerals, and the description thereof will be omitted. The communication device 100b periodically executes the processes of the flowcharts shown in FIG. 10A and 10B, for example.

[0124] The control device 104b controls the non-AP radio 102b to receive a DMG (Directional Multi Gigabit) beacon frame transmitted from the AP radio 101c of the vehicle 10C (S1101-1).

[0125] After receiving the DMG beacon frame, the control device 104b controls the non-AP radio 102b to transmit a probe request to the AP radio 101c of the vehicle 10C (S1102-1).

[0126] The control device 104b controls the non-AP radio 102b to receive a probe response including a neighbor report from the AP radio 101c of the vehicle 10C (S1103-1). The neighbor report, which will be described later, is information about the AP radio 101 of another communication device 100 that can be connected directly or by routing (for example, multi-hop) (for example, a list of BSSIDs of the connectable AP radio 101).

[0127] The control device 104b controls the non-AP radio 102b to receive the DMG beacon frame transmitted from the AP radio 101d of the vehicle 10D (S1101-2).

[0128] After receiving the DMG beacon frame, the control device 104b controls the non-AP radio 102b to transmit a probe request to the AP radio 101d of the vehicle 10D (S1102-2).

[0129] The control device 104b controls the non-AP radio 102b to receive a probe response including a neighbor report from the AP radio 101d of the vehicle 10D (S1103-2).

[0130] After the beacon frame scanning time has elapsed, the control device 104b selects the AP wireless device 101 to which it is to connect (S1105).

[0131] For example, the control device 104b selects one of the AP radio 101c of the vehicle 10C that received the DMG beacon frame in S1101-1 and the AP radio 101d of the vehicle 10D that received the DMG beacon frame in S1101-2.

[0132] Here, if the control device 104b associates with the AP radio 101c, it can communicate with the AP radio 101c and the AP radio 101 having the BSSID listed in the list received in S1103-1. Therefore, the control device 104b can obtain the number of connectable subnets when associating with the AP radio 101c from the list received in S1103-1. Similarly, the control device 104b can obtain the number of connectable subnets when associating with the AP radio 101d from the list received in S1103-2.

[0133] The control device 104b acquires the current number of communicable BSSIDs (number of connectable subnets) in S1112, which will be described later. The control device 104b compares the number of BSSIDs acquired in S1112 (for example, acquired in the previous flow chart processing) with the number of connectable subnets when connected to the AP radio 101c acquired in S1103-1. The control device 104b compares the number of BSSIDs acquired in S1112 with the number of connectable subnets when connected to the AP radio 101d acquired in S1103-2. The control device 104b selects the AP radio 101c or AP radio 101d that has the larger increase (largest increase) in the number of newly connectable subnets (number of newly connectable AP radios).

[0134] The control device 104b controls the AP radio 101b to obtain a list of AP radios 101 (list of BSSIDs) connectable directly or by routing from the communication devices 100a, 100c, and 100d of the vehicles 10A, 10C, and 10D (S1112).

[0135] When the control device 104b acquires the list of BSSIDs in S1112, the control device 104b transmits a probe response including a neighbor report (S1113). The neighbor report includes the list of BSSIDs acquired in S1112. The neighbor report may be transmitted, for example, by using the probe response.

[0136] Fig. 11 is a diagram for explaining an example of a probe response frame. Fig. 11 shows a probe response frame (probe response signal) transmitted by the AP radio 101b of the vehicle 10B. Explanations of blank field elements shown in Fig. 11 are omitted. As shown in Fig. 11, the probe response includes a frame body field.

[0137] The frame body field contains a neighbor report element. In the example of Fig. 11, the frame body field contains neighbor report elements for AP radios 101a, 101c, and 101d. The neighbor report elements for AP radios 101a, 101c, and 101d contain the BSSIDs of AP radios 101a, 101c, and 101d.

[0138] As described above, the control device 104 may select an AP radio to which the AP radio 102 connects based on the increase in the number of subnets. This allows the communication device 100 to establish a wireless link with the AP radio of another vehicle entering the intersection.

[0139] Furthermore, if the AP radio device 101 transmits routing information in advance, the non-AP radio device 102b can set up routing with little delay after starting connection processing.

[0140] If routing is established to the Internet (routing is established to the roadside device, and as a result, routing is established to the Internet), the control device 104 may select the non-AP radio device 102 having the fewest number of hops to the roadside device (or an ITS (Intelligent Transport Systems) server) which is the gateway to the Internet. The AP radio device 101 may notify the number of hops by using a neighbor report in the probe response.

[0141] Furthermore, for example, when the control device 104 enters an intersection, the control device 104 may obtain the relative speed of other vehicles and select the AP radio 101 of a vehicle whose obtained relative speed is smaller than a predetermined threshold. The relative speed of the vehicle may be obtained using a beacon frame or a probe response frame. Furthermore, the relative speed of the vehicle may be obtained (calculated) from information such as the absolute speed and azimuth angle of the vehicle notified by another communication method.

[0142] In addition, the control device 104 may connect to the AP radio 101 with a high relative speed, perform a certain amount of communication, and then disconnect and connect to another AP radio.

[0143] (Third embodiment) In the first and second embodiments, the AP radio 101 communicates at the front of the vehicle. In the third embodiment, the AP radio also communicates at the rear of the vehicle.

[0144] Fig. 12 is a diagram showing an example of a block configuration of a communication device 300 according to the third embodiment. As shown in Fig. 12, the communication device 300 includes an AP radio device 301, non-AP radio devices 102, 303, and 323, a control device 314, and antennas 111, 311, 321, 112, 313, and 333. A position detection device 200 is connected to the communication device 300.

[0145] AP radio 301 is connected to antennas 111, 311 and 321. Non-AP radios 102, 303 and 323 are connected to antennas 112, 313 and 333, respectively.

[0146] The control device 314 performs routing control for a subnetwork (BSS) in which the AP radio 301 and the non-AP radio devices 102, 303, and 323 participate. The control device 314 also determines a network address for the BSS that is provided by the AP radio 301. The control device 314 may be configured by a processor such as a CPU or a DSP.

[0147] The communication device 300 may include multiple control devices. For example, the multiple control devices may be provided one for each of the AP radio device 301 and the non-AP radio devices 102, 303, and 323. The multiple control devices may be connected by the connection circuit 106 described in FIG.

[0148] Also, the non-AP radios 102, 303, 323 may be physically separate. Also, the non-AP radios 102, 303, 323 may be physically one radio, and one radio may have the functions of the non-AP radios 102, 303, 323.

[0149] Also, the AP radio 301 and the non-AP radios 102, 303, and 323 may be physically separate. The AP radio 301 and the non-AP radios 102, 303, and 323 may be physically one radio, and the one radio may have the functions of the AP radio 101 and the non-AP radios 102, 303, and 323.

[0150] 13 is a diagram illustrating an example of the directivity of antennas 111, 112, 311, 313, 321, and 333. Antennas 111 and 112 that radiate radio waves ahead of the vehicle may have directivity with a half-power angle of 5°, as shown in sector 201, for example. Antennas 111 and 112 may change the direction of directivity within a range of 120° in front of the vehicle (60° to the left and 60° to the right of the front of the vehicle), as shown in sector 202, for example.

[0151] Antenna 311 connected to AP radio 301 and antenna 313 connected to non-AP radio 303 may have directivity with a half-power angle of 5°, as shown in sector 205, for example. Antennas 311, 313 may change the direction of directivity in a range of 120° to the left rear of the vehicle, as shown in sector 206, for example.

[0152] Antenna 321 connected to AP radio 301 and antenna 333 connected to non-AP radio 323 may have directivity with a half-power angle of 5°, as shown in sector 207, for example. Antennas 321, 333 may change the direction of directivity in a range of 120° to the left rear of the vehicle, as shown in sector 208, for example.

[0153] AP radio 301 communicates with vehicles (non-AP radios) in a 360° direction around vehicle 10 by switching between or simultaneously using antennas 111, 311, and 321. Also, communication device 300 is provided with non-AP radios 102, 303, and 323 connected to antennas 112, 313, and 333, respectively, to communicate with vehicles (AP radios) in a 360° direction around vehicle 10. Communication device 300 communicates with at least one communication device (AP radio) in each direction of sectors 202, 206, and 208 shown in FIG.

[0154] It should be noted that the antennas 111, 112, 311, 313, 321, and 333 cover an angular range of 120° or more (for example, 140°), and the coverage ranges may overlap.

[0155] Also, for example, four antennas may be connected to AP radio 301, and each antenna may cover an angular range of 90° at the four corners of vehicle 10. Communication device 300 may include four non-AP radios, and each non-AP radio may cover an angular range of 90° at the four corners of vehicle 10.

[0156] 14 is a diagram illustrating an example of inter-vehicle communication according to the third embodiment. Vehicles 10A, 10B, 10C, and 10D shown in FIG. 14 are equipped with the communication device 300 shown in FIG.

[0157] In the following, in order to distinguish between the communication devices 300 installed in the vehicles 10A, 10B, 10C, and 10D, the communication device installed in the vehicle 10A may be referred to as communication device 300a, the communication device installed in the vehicle 10B as communication device 300b, the communication device installed in the vehicle 10C as communication device 300c, and the communication device installed in the vehicle 10D as communication device 300d.

[0158] In order to distinguish between the units of the communication devices 300a, 300b, 300c, and 300d, the reference numerals of the units of the communication devices 300a, 300b, 300c, and 300d may be followed by the letters a, b, c, and d.

[0159] The communication devices 300a, 300b, 300c, and 300d mounted on the vehicles 10A, 10B, 10C, and 10D perform communication based on the infrastructure mode.

[0160] Both vehicle 10A and vehicle 10B travel in the same direction on a road, for example. The non-AP radio 303a of vehicle 10A connects to the AP radio 301b of the following vehicle 10B and performs inter-vehicle communication.

[0161] The non-AP radios 303a and 323a of the vehicle 10A respectively cover communications on the right rear and left rear of the vehicle 10A. The non-AP radio 323a of the vehicle 10A communicates with, for example, the AP radio 301c of the vehicle 10C traveling in the oncoming lane.

[0162] The AP radio 301c of the vehicle 10C covers communication in the front, right rear, and left rear of the vehicle 10C. The AP radio 301c of the vehicle 10C communicates with, for example, the non-AP radio 323a of the vehicle 10A traveling in the oncoming lane. The AP radio 301c of the vehicle 10C also communicates with, for example, the non-AP radio 102b of the vehicle 10B traveling in the oncoming lane.

[0163] The operation of the communication device 300 is similar to that described in the flowchart of FIG. 8, and therefore a description thereof will be omitted.

[0164] As described above, the AP radio 301 and the antennas 111, 311, 321 may transmit and receive radio waves toward the front, right rear, and left rear of the vehicle 10. This allows the communication device 100 to communicate with communication devices of vehicles 10 traveling in front, behind, and to the sides.

[0165] In the above-described embodiments, the notation "... part" or "... machine" used for each component may be replaced with other notations such as "... circuit", "... assembly", "... device", "... unit", or "... module".

[0166] Although the embodiments have been described above with reference to the drawings, the present disclosure is not limited to such examples. It is clear that a person skilled in the art can come up with various modified or altered examples within the scope of the claims. It is understood that such modified or altered examples also belong to the technical scope of the present disclosure. In addition, the components in the embodiments may be arbitrarily combined within the scope of the present disclosure.

[0167] The present disclosure can be realized by software, hardware, or software in cooperation with hardware. Each functional block used in the description of the above embodiment may be realized partially or entirely as an LSI, which is an integrated circuit, and each process described in the above embodiment may be controlled partially or entirely by one LSI or a combination of LSIs. The LSI may be composed of individual chips, or may be composed of one chip that includes some or all of the functional blocks. The LSI may have input and output of data. Depending on the degree of integration, the LSI may be called an IC, a system LSI, a super LSI, or an ultra LSI.

[0168] The method of integration is not limited to LSI, and may be realized by a dedicated circuit, a general-purpose processor, or a dedicated processor. Also, after LSI manufacturing, a programmable FPGA (Field Programmable Gate Array) or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used. The present disclosure may be realized as digital processing or analog processing.

[0169] Furthermore, if a new integrated circuit technology that can replace LSI appears due to the progress of semiconductor technology or a derivative technology, it is possible to integrate the functional blocks using that technology. The application of biotechnology is also a possibility.

[0170] The present disclosure may be implemented in any type of apparatus, device, or system having a communication function (collectively referred to as a communication apparatus). The communication apparatus may include a radio transceiver and processing / control circuitry. The radio transceiver may include a receiver and a transmitter, or both as functions. The radio transceiver (transmitter and receiver) may include a radio frequency (RF) module and one or more antennas. The RF module may include an amplifier, an RF modulator / demodulator, or the like. Non-limiting examples of communication devices include telephones (e.g., cell phones, smartphones, etc.), tablets, personal computers (PCs) (e.g., laptops, desktops, notebooks, etc.), cameras (e.g., digital still / video cameras), digital players (e.g., digital audio / video players), wearable devices (e.g., wearable cameras, smart watches, tracking devices, etc.), game consoles, digital book readers, telehealth and telemedicine devices, communication-enabled vehicles or mobile conveyances (e.g., cars, airplanes, boats, etc.), and combinations of the above devices.

[0171] Communications Equipment includes, but is not limited to portable or mobile equipment, non-portable or fixed equipment, devices and systems of any kind, such as smart home devices (appliances, lighting equipment, smart meters or metering devices, control panels, etc.), vending machines and any other "Things" that may exist on an Internet of Things (IoT) network.

[0172] Communications include data communications via cellular systems, wireless LAN systems, communications satellite systems, etc., as well as data communications via combinations of these.

[0173] A communications apparatus also includes devices, such as controllers and sensors, connected or coupled to a communications device that performs the communications functions described in this disclosure, such as controllers and sensors that generate control and data signals used by the communications device to perform the communications functions of the communications apparatus.

[0174] The communication apparatus also includes infrastructure facilities, such as base stations, access points, and any other apparatus, device, or system that communicates with or controls the various apparatuses listed above, but are not limited to these.

[0175] Summary of the Disclosure The communication device of the present disclosure is a communication device mounted on a vehicle and has a first communication circuit that operates as an access point in infrastructure mode and transmits and receives radio waves toward the front of the vehicle, and a second communication circuit that operates as a station in infrastructure mode and transmits and receives radio waves toward the front of the vehicle.

[0176] In the communication device of the present disclosure, when the vehicle enters a predetermined area including an intersection and a wireless link with the communication device of the first vehicle is established, the second communication circuit disconnects the wireless link with the communication device of the first vehicle.

[0177] In the communication device according to the present disclosure, the second communication circuit establishes a wireless link with a communication device of a second vehicle different from the communication device of the first vehicle.

[0178] In the communication device according to the present disclosure, the second communication circuit selects a communication device of a second vehicle with which to establish a wireless link based on a quality of a beacon signal.

[0179] In the communication device according to the present disclosure, the second communication circuit selects a communication device of a second vehicle with which to establish a wireless link based on an increase in the number of subnets.

[0180] In the communication device according to the present disclosure, the second communication circuit prioritizes establishment of a wireless link with a roadside unit over establishment of a wireless link with a communication device of another vehicle.

[0181] In the communication device according to the present disclosure, the first communication circuit transmits a probe response signal including information regarding an access point of a communication device of another vehicle.

[0182] In the communication device according to the present disclosure, the first communication circuit transmits and receives radio waves toward the rear of the vehicle.

[0183] In the communication device according to the present disclosure, the second communication circuit transmits and receives radio waves toward the rear of the vehicle.

[0184] The communication method of the present disclosure is a communication method of a communication device mounted on a vehicle, in which a first communication circuit operates as an access point in infrastructure mode, the first communication circuit transmitting and receiving radio waves toward the front of the vehicle, and a second communication circuit operates as a station in infrastructure mode, the second communication circuit transmitting and receiving radio waves toward the front of the vehicle. [Industrial Applicability]

[0185] The present disclosure is suitable for wireless communication between vehicles or between a roadside unit and a vehicle, for example. [Explanation of symbols]

[0186] 10, 10A, 10B, 10C, 10D 101, 101a, 101b, 101c, 101d AP wireless devices 301, 301a, 301b, 301c, 301d AP wireless devices 102, 102a, 102b, 102c, 103d Non-AP wireless devices 103, 103a, 103b, 103c, 103d Non-AP wireless devices 303, 303a, 303b, 303c, 303d Non-AP wireless devices 323, 323a, 323b, 323c, 323d Non-AP wireless devices 104, 105, 114, 314 control device 106 Connecting circuit 111, 112, 113, 311, 321, 313, 333 アンテナ 200 position output device

Claims

1. A communication device mounted on a vehicle, a first communication circuit that operates as an access point in an infrastructure mode and transmits and receives radio waves toward a front of the vehicle; a second communication circuit that operates as a station in an infrastructure mode and transmits and receives radio waves toward the front of the vehicle; Equipped with the second communication circuit selects the communication device of the second vehicle to establish a wireless link based on a larger one of an increase in the number of subnets in the first access point to which the connection is to be made and an increase in the number of subnets in the second access point to which the connection is to be made. Communications equipment.

2. When the vehicle enters a predetermined area including an intersection and a wireless link is established with the communication device of the first vehicle, the second communication circuit cuts off the wireless link with the communication device of the first vehicle. The communication device according to claim 1 .

3. the second communication circuit establishes a wireless link with a communication device of a second vehicle different from the communication device of the first vehicle; The communication device according to claim 2 .

4. the second communication circuit prioritizes establishment of a wireless link with the roadside device over establishment of a wireless link with a communication device of another vehicle; A communication device according to any one of claims 1 to 3.

5. The first communication circuit transmits a probe response signal including information about an access point of a communication device of another vehicle. A communication device according to any one of claims 1 to 4.

6. The first communication circuit transmits and receives radio waves toward the rear of the vehicle. A communication device according to any one of claims 1 to 5.

7. A communication method for a communication device mounted on a vehicle, comprising: the first communication circuit operates as an access point in an infrastructure mode; the first communication circuit transmits and receives radio waves toward the front of the vehicle; the second communication circuit operates as a station in an infrastructure mode; the second communication circuit transmits and receives radio waves toward the front of the vehicle; the second communication circuit selects the communication device of the second vehicle to establish a wireless link based on the larger of an increase in the number of subnets in the first access point to which the connection is to be made and an increase in the number of subnets in the second access point to which the connection is to be made; Communication methods.

8. A communication device mounted on a vehicle, a first communication circuit that operates as an access point in an infrastructure mode and transmits and receives radio waves toward a front of the vehicle; a second communication circuit that operates as a station in an infrastructure mode and transmits and receives radio waves toward the front of the vehicle; a third communication circuit that operates as a station in an infrastructure mode and transmits and receives radio waves toward the rear of the vehicle; A communication device having the above configuration.

9. A communication method for a communication device mounted on a vehicle, comprising: the first communication circuit operates as an access point in an infrastructure mode; the first communication circuit transmits and receives radio waves toward the front of the vehicle; the second communication circuit operates as a station in an infrastructure mode; a second communication circuit for transmitting and receiving radio waves toward a front of the vehicle; a third communication circuit operates as a station in an infrastructure mode; a third communication circuit for transmitting and receiving radio waves toward the rear of the vehicle; Communication methods.

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