Communication device, communication system, control method and program for communication device

Abstract

To implement Sidelink communication with a specific communication partner even at a place at which a plurality of partners with which communication is possible exist.SOLUTION: A communication device comprises: extraction means for extracting a feature of a transmission destination included in an imaged picture from the imaged picture; creation means for creating a Layer-2 ID including feature information indicating the feature; and transmission means for transmitting the information in a Sidelink communication method using the Layer-2 ID.SELECTED DRAWING: Figure 10

Description

Technical Field

[0001] The present invention relates to a communication device, a communication system, a control method for a communication device, and a program.

Background Art

[0002] In recent years, the specifications of 3GPP (3rd Generation Partnership Project)'s LTE (Long Term Evolution) and next-generation (NR) have been under development. Among these, a standard specification called Sidelink communication has been established. This specification realizes direct wireless communication between devices using an interface called PC5 without going through a mobile communication network (core network). In Sidelink communication, a Layer-2 ID (hereinafter sometimes abbreviated as L2ID) is used as an identifier indicating a source device or a destination device.

[0003] For example, Patent Document 1 discloses a technique of using a communication identifier corresponding to a specific management area located around the current position of a communication terminal device as a destination communication identifier in order to realize vehicle-to-vehicle communication.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the technique of Patent Document 1, for example, even when it is desired to notify a specific target vehicle or the like of highly urgent information detected by a camera or a sensor, a response is also received simultaneously from unrelated vehicles or the like, and it takes time until the start of information exchange with the desired target. The problem that this invention aims to solve is to enable Sidelink communication with a specific communication partner even in a location where there are multiple communication partners. [Means for solving the problem]

[0006] To solve the above problems, a communication device according to one aspect of the present invention comprises: an image capture means for capturing an image; an extraction means for extracting characteristics of a transmission destination from an image captured by the image capture means; a generation means for generating a Layer-2 ID that includes characteristic information indicating the above characteristics; and a transmission means for transmitting information using the Layer-2 ID in a Sidelink communication manner. Furthermore, a communication device according to another aspect of the present invention comprises a storage means for storing features that can be extracted from captured images of an object on which the device is mounted, and a receiving means for receiving information in a Sidelink communication manner using a Layer-2 ID containing feature information indicating the above features. [Brief explanation of the drawing]

[0007] [Figure 1] A schematic diagram showing an example configuration of a communication system according to an embodiment of the present invention. [Figure 2] A block diagram showing an example of the functional configuration of the roadside device in this embodiment. [Figure 3] A block diagram showing an example of the functional configuration of the in-vehicle device and communication device in this embodiment. [Figure 4] A diagram showing an example of the hardware configuration of roadside equipment, in-vehicle equipment, and communication equipment. [Figure 5] This figure shows the first example of a Layer-2 ID generated by the ID generation unit. [Figure 6] This figure shows a second example of a Layer-2 ID generated by the ID generation unit. [Figure 7] This figure shows a third example of a Layer-2 ID generated by the ID generation unit. [Figure 8] A diagram showing the communication sequence in "Broadcast communication methods," etc. [Figure 9]A diagram showing the communication sequence in the "Unicast communication method". [Figure 10] A diagram showing the communication sequence between the on-board equipment of vehicle A and the roadside equipment. [Figure 11] A diagram showing the communication sequence between roadside devices and pedestrian communication devices. [Figure 12] A diagram showing the communication sequence between a roadside device and a bicycle's communication device. [Figure 13] A diagram illustrating the communication sequence between in-vehicle devices. [Figure 14] A flowchart illustrating the case where roadside equipment functions as a transmitting device. [Figure 15] A flowchart illustrating the case where the onboard equipment of vehicle A functions as a receiving device. [Figure 16] A flowchart illustrating the case where a pedestrian's communication device functions as a receiver. [Figure 17] A flowchart illustrating the case where a bicycle's communication device functions as a receiver. [Modes for carrying out the invention]

[0008] Embodiments of the present invention will be described in detail below with reference to the attached drawings. Note that the following embodiments are not limiting to the present invention. Furthermore, not all combinations of features described in the embodiments are essential to the solution of the present invention, and the features may be combined arbitrarily. The configuration of the embodiments may be modified or changed as appropriate depending on the specifications and various conditions (operating conditions, operating environment, etc.) of the system and apparatus to which the present invention is applied.

[0009] The technical scope of the present invention is defined by the claims and not by the individual embodiments described below. Furthermore, in the accompanying drawings, the same or similar components are denoted by the same reference numerals, and redundant descriptions are omitted. Components shown in the drawings described earlier may be referenced as appropriate in the descriptions of the drawings later.

[0010] <Communication System Configuration>

[0011] FIG. 1 is a diagram schematically showing a configuration example of a communication system according to an embodiment of the present invention. The communication system 10 of the present embodiment includes, as an example, a roadside device 101, in-vehicle devices 103 and 105, and portable communication devices 107 and 109. The roadside device 101 is installed near an intersection 20 or beside a road, and determines a traffic situation or the like based on a captured image of a camera 201 and a detection signal of a sensor 209. The roadside device 101 notifies notification information regarding the determined traffic situation or the like to passengers of vehicles 102 and 104, pedestrians 106, and bicycles 108. The notification of the notification information is performed by sidelink communication. The roadside device 101 may use not only its own detection result but also external information from, for example, a server on the Internet or the like for situation determination and notify vehicles and pedestrians by sidelink communication.

[0012] The in-vehicle devices 103 and 105 are mounted on vehicles 102 and 104 traveling on a road and communicate with devices outside the vehicle. In the following description, when distinguishing between the two vehicles 103 and 105 shown in FIG. 1, one vehicle 102 is referred to as vehicle A, and the other vehicle 104 is referred to as vehicle B. That is, one of the two in-vehicle devices 103 and 105, the in-vehicle device 103, is mounted on vehicle A, and the other in-vehicle device 105 is mounted on vehicle B. The in-vehicle devices 103 and 105 acquire information from outside the vehicle via sidelink communication and display it, or acquire information of vehicles 102 and 104 and share the information with external devices via sidelink communication.

[0013] Of the two portable communication devices 107 and 109 shown in FIG. 1, one communication device 107 is carried by a pedestrian 106 passing near the intersection 20. The other communication device 109 is installed on a bicycle 108 passing through the intersection 20 or carried by a passenger on the bicycle 108. In the following description, the bicycle 108 and the passenger on the bicycle 108 may be simply referred to as "bicycle" without distinction. For example, when it is said that it is mounted on the bicycle 108 below, it includes the situation of being carried by the passenger on the bicycle 108. The portable communication devices 107 and 109 acquire and display information transmitted to pedestrians 106 and bicycles 108 via Sidelink communication, and acquire information from pedestrians 106 and bicycles 108 and share that information with external devices via Sidelink communication.

[0014] <Device Functional Configuration> Next, the functional configuration of the roadside device 101, the in-vehicle devices 103 and 105, and the communication devices 107 and 109 of the communication system 10 will be described. Figure 2 is a block diagram showing an example of the functional configuration of the roadside device 101 in this embodiment. The roadside device 101 includes, as a functional configuration, a camera 201, a memory unit 202, a control unit 203, a situation determination unit 204, an ID generation unit 205, a feature extraction unit 206, a wireless communication unit 207, a wired communication unit 208, and a sensor 209.

[0015] Camera 201 photographs traffic conditions at intersection 20 and on the road, as well as vehicles 102 and 104, pedestrians 106 and bicycles 108 that are present near intersection 20 and the road. The memory unit 202 stores images captured by the camera 201 and information obtained through communication. The control unit 203 controls the overall operation of the roadside device 101. The situation determination unit 204 processes the captured images obtained by the camera 201 and the detection signals obtained by the sensor 209 to determine the traffic situation. The situation determination unit 204 generates notification information indicating the determined traffic situation.

[0016] The ID generation unit 205 generates Layer-2 IDs for each of the vehicles 102, 104, pedestrian 106, and bicycle 108, each containing characteristic information that describes their features. The feature extraction unit 206 extracts the characteristics of the vehicles 102 and 104, pedestrian 106, and bicycle 108, which are the destinations of the transmission, from the captured image obtained by the camera 201. The wireless communication unit 207 transmits and receives information with external wireless devices (i.e., in-vehicle devices 103, 105 and communication devices 107, 109, etc.) via Sidelink communication. Specifically, the wireless communication unit 207 transmits information via Sidelink communication using the Layer-2 ID generated by the ID generation unit 205. In this embodiment, the Sidelink communication is the Sidelink communication (PC5) standardized by 3GPP, and the Layer-2 ID is an identifier that indicates the destination of the communication in Sidelink communication standardized by 3GPP.

[0017] The wired communication unit 208 connects to the internet 30 and other devices via a wired connection to acquire information from other devices such as the server 40. The information acquired from other devices may be used by the situation determination unit 204 to determine traffic conditions, and may also be used to generate characteristic information that indicates specific features. Sensor 209 detects events useful for determining traffic conditions at intersection 20 and on roads, such as the degree of vehicle congestion and weather.

[0018] The roadside device 101 processes images captured by the camera 201 and detection signals from the sensor 209 in the situation determination unit 204 to determine the traffic conditions at the intersection 20 and on the road at each given time. Meanwhile, the roadside device 101 uses a feature extraction unit 206 to extract the characteristics of vehicles 102, 104, pedestrians 106, and bicycles 108 that appear in the captured images, based on the images taken by the camera 201 at each time.

[0019] Then, when the situation determination unit 204 of the roadside device 101 generates notification information indicating a traffic situation that should be notified to any of the vehicles 102, 104, pedestrians 106, or bicycles 108, the roadside device 101 transmits the notification information via the wireless communication unit 207. The roadside device 101 selects a recipient for the notification information from among the vehicles 102, 104, pedestrians 106, and bicycles 108 that are captured in the image, based on the traffic situation indicated by the information.

[0020] When transmitting notification information by the wireless communication unit 207, the roadside device 101 uses a Layer-2 ID containing characteristic information indicating the characteristics of the destination as an identifier. This allows the roadside device 101 to identify the destination and transmit notification information even when multiple communication-capable devices are present near the intersection 20. In addition, the roadside device 101 may also use feature information obtained from an external device such as a server 40 via the wired communication unit 208, in addition to feature information indicating features extracted from the image captured by the camera 201, to generate the Layer-2 ID.

[0021] Figure 3 is a block diagram showing an example of the functional configuration of the in-vehicle devices 103, 105 and the communication devices 107, 109 in this embodiment. In this embodiment, the in-vehicle devices 103, 105 and the communication devices 107, 109 have a common functional configuration. The in-vehicle devices 103, 105 and the communication devices 107, 109 are functionally configured to include a camera 301, a storage unit 302, a control unit 303, a situation determination unit 304, an ID generation unit 305, and a feature extraction unit 306. In addition, the in-vehicle devices 103, 105 and the communication devices 107, 109 are also functionally configured to include a wireless communication unit 307, a movement information acquisition unit 308, an operation unit 309, and a display unit 310.

[0022] Camera 301 captures images of the surroundings of vehicles 102 and 104, pedestrians 106, or bicycles 108. However, camera 301 is not essential for the functions of the in-vehicle devices 103 and 105 and the communication devices 107 and 109. For example, the in-vehicle devices 103 and 105 may obtain images from drive recorders or other devices installed in vehicles 102 and 104. Also, the communication devices 107 and 109 do not need to take images. The memory unit 302 stores images captured by the camera 301 and information obtained through communication. The memory unit 302 also stores features that can be extracted from the captured images of the vehicles 102, 104, pedestrian 106, and bicycle 108, which are the mounting structures on which the device is installed.

[0023] The control unit 303 controls the overall operation of the in-vehicle devices 103 and 105 and the communication devices 107 and 109. The situation determination unit 304 processes the captured images obtained by the camera 201 to determine the traffic situation and generates notification information indicating the determined traffic situation. The ID generation unit 305 generates a Layer-2 ID that includes characteristic information indicating the characteristics of the communication partner among the vehicles 102, 104, pedestrian 106, and bicycle 108.

[0024] In this embodiment, the ID generation unit 305 also generates a Layer-2 ID for information reception that includes characteristic information indicating the features of the vehicles 102, 104, pedestrians 106, and bicycles 108 on which the device is mounted. However, the Layer-2 ID for information reception may not be generated by the ID generation unit 305, and a predetermined Layer-2 ID may be stored in the storage unit 302 and used for reception. The feature extraction unit 306 extracts the characteristics of the communication partner from the captured image obtained by the camera 201.

[0025] The wireless communication unit 307 transmits and receives information with an external wireless device via Sidelink communication. The wireless communication unit 307 waits for Sidelink communication using a Layer-2 ID that contains characteristic information indicating the characteristics of the vehicles 102 and 104, pedestrians 106, and bicycles 108 equipped with its device, and receives information via Sidelink communication using the said Layer-2 ID. The movement information acquisition unit 308 acquires location information, speed information, etc., from the vehicles 102, 104, pedestrians 106, and bicycles 108 on which the device is installed. The movement information acquisition unit 308 acquires location information, speed information, etc., from, for example, the GPS circuit of the device itself. If the device is an in-vehicle device 103 or 105, the movement information acquisition unit 308 may acquire location information, speed information, etc., from the navigation system of the vehicles 102 or 104.

[0026] The control unit 309 receives operations on the in-vehicle devices 103 and 105 and the communication devices 107 and 109. The display unit 310 displays traffic conditions and other information indicated by notification information received from other devices. The in-vehicle devices 103, 105 and the communication devices 107, 109 have previously received input from the operation unit 309 regarding the characteristics of the vehicles 102, 104 on which they are mounted, pedestrians 106, and bicycles 108, and stored this information in the storage unit 302. If the device is, for example, an in-vehicle device 103 or 105, then characteristics may be automatically acquired from the vehicles 102 or 104 on which it is mounted and stored in the storage unit 302.

[0027] The features are stored in the storage unit 302 in the form of feature information used for generating Layer-2 IDs in the ID generation unit 305. The storage unit 302 may also store the features in the form of a generated Layer-2 ID. The storage unit 302 may also store the features in another format that can be converted to Layer-2 IDs or feature information.

[0028] In the in-vehicle devices 103, 105 and communication devices 107, 109, when waiting for notification information indicating traffic conditions, a Layer-2 ID containing characteristic information indicating the characteristics of the device itself is used, so that only notification information transmitted specifically identifying the device is received. Information reception by the in-vehicle devices 103, 105 and communication devices 107, 109 is not limited to cases where all of the characteristic information included in the Layer-2 ID matches. That is, if the characteristic information indicates multiple characteristics, the in-vehicle devices 103, 105 and communication devices 107, 109 may receive notification information using a Layer-2 ID in which some of the multiple characteristics match.

[0029] In this embodiment, the in-vehicle devices 103, 105 and the communication devices 107, 109 also have the function of determining the surrounding conditions of their own devices and transmitting notification information to other devices. That is, the in-vehicle devices 103, 105 and the communication devices 107, 109 process images captured by the camera 301 in the situation determination unit 304 to determine the surrounding traffic conditions. Then, when a traffic condition that should be notified to other devices occurs, the in-vehicle devices 103, 105 and the communication devices 107, 109 transmit notification information via the wireless communication unit 307. However, communication devices 107 and 109 may only receive information without having the function to transmit notification information to other devices. If they only receive notification information, communication devices 107 and 109 do not have a status determination unit 304, and the camera 301 is not essential for communication devices 107 and 109.

[0030] In this embodiment, the in-vehicle devices 103, 105 and the communication devices 107, 109 generate a Layer-2 ID, which is a transmission identifier. The in-vehicle devices 103, 105 and the communication devices 107, 109 extract features of vehicles, pedestrians, etc., that are visible in the captured image using the feature extraction unit 306. The in-vehicle devices 103, 105 and the communication devices 107, 109 select a transmission destination from among the vehicles, pedestrians, etc., visible in the captured image, according to the traffic situation to be notified.

[0031] The in-vehicle devices 103 and 105 and the communication devices 107 and 109 transmit traffic condition information via the wireless communication unit 307, using a Layer-2 ID containing characteristic information indicating the characteristics of the destination as an identifier. This allows the in-vehicle devices 103 and 105 and the communication devices 107 and 109 to identify the destination and transmit information even when multiple communication-capable devices are present in the vicinity.

[0032] The configurations shown in Figures 2 and 3 are examples only. Some (and sometimes all) of the functional blocks may be replaced with other functional blocks that perform similar functions, some functional blocks may be omitted, and further functional blocks may be added. In addition, one functional block as described below may be divided into multiple functional blocks, or multiple functional blocks may be merged into one functional block.

[0033] <Hardware Configuration> In this embodiment, the roadside device 101, the in-vehicle devices 103 and 105, and the communication devices 107 and 109 have similar hardware configurations. In the following description, when referring to the roadside device 101, the in-vehicle devices 103 and 105, and the communication devices 107 and 109 collectively, they will be referred to as "roadside device 101, etc." Figure 4 shows an example of the hardware configuration of the roadside device 101, the in-vehicle devices 103 and 105, and the communication devices 107 and 109. The roadside equipment 101, etc., is equipped with a CPU 1601, ROM 1602, RAM 1603, auxiliary storage device 1604, communication interface (I / F) 1605, and device interface (I / F) 1606. CPU stands for Central Processing Unit. ROM stands for Read Only Memory, and RAM stands for Random Access Memory.

[0034] The CPU 1601 controls the entire roadside equipment 101 and other components using computer programs and data stored in the ROM 1602 or RAM 1603. The functions shown in Figures 2 and 3 are realized through the control of the CPU 1601. ROM1602 stores programs and other data that do not require modification. RAM1603 temporarily stores programs and data supplied from auxiliary storage device 1604, as well as data supplied from external sources via communication interface 1605. The auxiliary storage device 1604 is composed of, for example, a hard disk drive and stores various types of data.

[0035] The communication interface 1605 is used for communication with external devices. For example, the wireless communication units 207 and 307 shown in Figures 2 and 3 perform wireless communication with external devices via the communication interface 1605. The device interface 1606 connects various devices to the roadside device 101, etc., either as components of the roadside device 101, etc., or as external elements. For example, the device interface 1606 can connect display devices and input devices to the roadside device 101 for server administrators to check information managed by the roadside device 101. The device interface 1606 can also connect sensors 209 and cameras 201 to the roadside device 101. Furthermore, the device interface 1606 can connect cameras 301 and sensors on vehicles 102 and 104 to the in-vehicle devices 103 and 105.

[0036] In FIG. 4, an example is shown in which the components shown in FIGS. 2 and 3 are realized by a program and a CPU. However, the components shown in FIGS. 2 and 3 may be implemented by one or more dedicated hardware. When the components shown in FIGS. 2 and 3 are implemented by hardware, for example, a dedicated circuit may be automatically generated on an FPGA from a program for realizing each component by using a predetermined compiler. FPGA is an abbreviation for Field Programmable Gate Array. Also, a Gate Array circuit may be formed in the same manner as the FPGA and realized as hardware. Also, it may be realized by an ASIC (Application Specific Integrated Circuit).

[0037] <Regarding Layer-2 ID and Sidelink Communication> FIGS. 5 to 7 are diagrams showing examples of Layer-2 IDs generated by the ID generation units 207 and 305. The Layer-2 ID as an identifier indicating the communication destination in Sidelink communication formulated by 3GPP consists of a total of 3 bytes of data. That is, the Layer-2 ID has the uppermost byte described as "2 bytes", the middle byte described as "1 byte", and the lowermost byte described as "0 byte" in FIGS. 5 to 7. In the ID generation units 207 and 305 of the roadside device 101, in-vehicle devices 103 and 105, and communication devices 107 and 109, the Layer-2 IDs shown in FIGS. 5 to 7 are generated.

[0038] As described above, the Layer-2 IDs generated by the ID generation units 207 and 305 include characteristic information. The feature information used for vehicles 102 and 104 includes at least one of the following features: vehicle number, vehicle type, body shape, body color, direction of travel, speed, position, number of occupants, status of turn signals, and status of brake lights. The vehicle number is easily distinguishable from other vehicles, and the numerical value extracted from the image is both a feature and can be used directly as feature information. For this reason, it is preferable to use the vehicle number as a feature for vehicles 102 and 104. Furthermore, at least one of the following characteristics of pedestrian 106 is used as a characteristic indicated by the characteristic information: clothing, hairstyle, skin color, gender, walking direction, speed, and position. In addition, at least one of the following characteristics of bicycle 108 is used as a characteristic indicated by the characteristic information: vehicle type, body shape, number of wheels, body color, rider's clothing, rider's clothing color, direction of travel, speed, and position. For example, in the case of a bicycle with a vehicle number, such as a rental bicycle, the vehicle number may be used as a characteristic.

[0039] In the ID generation units 207 and 305 of the roadside device 101, the in-vehicle devices 103 and 105, and the communication devices 107 and 109, a Layer-2 ID is generated that includes feature information indicating one or more of the above-mentioned features. In the example shown in Figure 5, the Layer-2 ID contains characteristic information indicating the type, color, and direction of movement of the destination. For example, if the most significant byte ("2 bytes") is valued as "00", it indicates that the destination type is a "passenger car," and if it is valued as "F1", it indicates that the destination type is a "bicycle." In other words, the value of the most significant byte ("2 bytes") is characteristic information indicating the type of destination.

[0040] Furthermore, if the middle byte "1 byte" has a value of, for example, "00", it indicates that the color is "white", and if the value is "01", it indicates that the color is "blue". In other words, the value of the middle byte "1 byte" is characteristic information that indicates the color. Furthermore, if the least significant byte, "0byte," is valued as "00," for example, it indicates that the direction of movement is "east," and if it is valued as "01," it indicates that the direction of movement is "west." In other words, the value of the least significant byte, "0byte," is characteristic information indicating the direction of movement.

[0041] In the example shown in Figure 6, the Layer-2 ID includes characteristic information indicating the type, color, and vehicle number of the recipient. The Layer-2 ID shown in Figure 6 is generated when the vehicle number of the recipient is extracted from the captured image. In the Layer-2 ID shown in Figure 6, the values ​​of the most significant byte ("2 bytes") and the middle byte ("1 byte") indicate the type and color of the destination, similar to the example shown in Figure 5. In the Layer-2 ID shown in Figure 6, the value of the least significant byte, "0 byte," represents the last two digits of the vehicle number. In other words, in the example shown in Figure 6, the value of the least significant byte, "0 byte," is characteristic information indicating the vehicle number.

[0042] The Layer-2 IDs shown in Figures 5 and 6 contain multiple feature information indicating multiple characteristics, but the example shown in Figure 7 contains feature information indicating only one characteristic. Specifically, the Layer-2 ID shown in Figure 7 contains feature information indicating the vehicle number. Specifically, the value "FF" in the most significant byte "2 bytes" of the Layer-2 ID shown in Figure 7 indicates that it is a Layer-2 ID in vehicle number mode. The values ​​of the middle byte "1 byte" and the least significant byte "0 bytes" represent the first two digits and the last two digits of the vehicle number, respectively. The Layer-2 ID shown in Figure 7 and one of the Layer-2 IDs shown in Figures 5 and 6 can be used interchangeably. In other words, if the value of the most significant byte ("2 bytes") in the Layer-2 ID is anything other than "FF", the feature information will be interpreted as the Layer-2 ID shown in Figure 5 or Figure 6. Conversely, if the value of the most significant byte ("2 bytes") is "FF", the feature information (i.e., the vehicle number) will be interpreted as the Layer-2 ID shown in Figure 7.

[0043] The Layer-2 IDs shown in Figures 5 to 7 are generated by the ID generation units 207 and 305 of the roadside device 101, the in-vehicle devices 103 and 105, and the communication devices 107 and 109, respectively, as identifiers for transmission or reception, and are used for sending and receiving information in Sidelink communication.

[0044] Here, we will explain the communication methods used in Sidelink communication. There are three communication methods in Sidelink communication: "Broadcast communication method," "Groupcast communication method," and "Unicast communication method." Figure 8 is a sequence diagram showing the communication sequence in the "Broadcast communication method" and the "Groupcast communication method". In the "Broadcast communication method" and the "Groupcast communication method," a Layer-2 ID (abbreviated as "L2ID" in Figure 8), which is an identifier, is set as the destination on the transmitting and receiving devices (i.e., the transmitting device and the receiving device), respectively. The transmitting device attaches the Layer-2 ID set as the destination to the transmission data and sends it. The transmission data is then received by the receiving device, which has set a Layer-2 ID as the destination that shares at least some commonality with the Layer-2 ID attached to the transmission data.

[0045] In other words, in the "Broadcast communication method" and the "Groupcast communication method," data communication between devices is possible by setting Layer-2 IDs on the transmitting and receiving devices. Therefore, if there are multiple receiving devices that have set a Layer-2 ID common to the Layer-2 ID assigned to the transmitted data as the receiving destination, multiple receiving devices will receive the transmitted data simultaneously.

[0046] Figure 9 is a sequence diagram showing the communication sequence in the "Unicast communication method". In the "Unicast communication method," the transmitting device sends a connection request to the destination identified by the Layer-2 ID. The receiving device exchanges security information with the transmitting device if it has set the destination to a Layer-2 ID that shares at least some commonality with the Layer-2 ID attached to the connection request. Once a secure communication link is established through the exchange of security information, data communication becomes possible between the transmitting and receiving devices. In the communication system 10 of this embodiment, any communication method can be applied, but in the processing examples described below, the "Unicast communication method" will be used.

[0047] <Examples of processing in communication systems> Figures 10 to 12 are sequence diagrams showing the communication processing sequence between the roadside device 101 and the on-board device 103 and communication devices 107 and 109. Figure 10 shows the processing between the on-board device 103 of vehicle A and the roadside device 101, representing two on-board devices 103 and 105. Figure 11 shows the processing between the roadside device 101 and the communication device 107 of pedestrian 106. Figure 12 shows the processing between the roadside device 101 and the communication device 109 of bicycle 108. In the following description, the on-board device 103 and the communication devices 107 and 109 will be collectively referred to as "on-board device 103, etc."

[0048] The on-board device 103 and communication devices 107 and 109 generate Layer-2 IDs for reception from the characteristic information of the mounted vehicle 102, pedestrian 106, and bicycle 108 (F601, F801, F901). The on-board device 103 generates two Layer-2 IDs for reception, for example, "AAA" and "AAA'" from two pieces of characteristic information. The communication device 107 for pedestrian 106 generates a Layer-2 ID, for example, "CCC," from the characteristic information representing the pedestrian 106. The communication device 109 for bicycle 108 generates a Layer-2 ID, for example, "DDD," from the characteristic information representing the bicycle 108. Note that the on-board device 103 may generate one Layer-2 ID, or the communication devices 107 and 109 may generate multiple Layer-2 IDs from multiple pieces of characteristic information.

[0049] The in-vehicle device 103 and the communication devices 107 and 109 start waiting for Sidelink communication using the generated Layer-2 ID (F602, F802, F902). In the roadside device 101, when a vehicle 102, pedestrian 106, or bicycle 108 enters the imaging range of the camera 201 of the roadside device 101, features are extracted from the image captured by the camera 201 (F603, F803, F903). Then, the roadside device 101 generates a Layer-2 ID for transmission from the feature information indicating the extracted features (F604, F804, F904).

[0050] When the roadside device 101 detects an event that should be notified to a vehicle 102, pedestrian 106, or bicycle 108 via the camera 201 or sensor 209 (F605, F805, F905), the roadside device 101 generates notification information (F606, F806, F906). The roadside device 101 requests a connection using one or more Layer-2 IDs generated by F604, F804, and F904 (F607, F807, F907) to transmit notification information to the vehicle's onboard device 103, etc. The onboard device 103 and communication devices 107 and 109 respond to the exchange of security information if any of the one or more Layer-2 IDs used in the connection request match the waiting Layer-2 IDs.

[0051] If the Layer-2 ID contains multiple feature information, the in-vehicle device 103 may respond to the exchange of security information if some or all of the multiple feature information matches some or all of the feature information of the waiting Layer-2 ID. In other words, the in-vehicle device 103 may receive information using a Layer-2 ID that contains multiple feature information if all or part of the multiple feature information is feature information that indicates the characteristics of the mounted device. Security is established between the roadside device 101 and the on-board device 103 when the on-board device 103 responds to the exchange of security information (F608, F808, F908). Once security is established, the on-board device 103 or the communication devices 107, 109 transmit a connection acceptance to the roadside device 101 (F609, F809, F909).

[0052] Upon receiving the connection acceptance, the roadside device 101 transmits notification information to the on-board device 103, etc., and the on-board device 103, etc., receives the notification information (F610, F810, F910). Once all notification information has been sent and received, and the vehicle 102, pedestrian 106, or bicycle 108 moves out of the field of view of the roadside device 101's camera 201, the roadside device 101 requests to disconnect Sidelink communication (F611, F811, F911). When the in-vehicle device 103 or communication devices 107, 109 respond to the disconnection request (F612, F812, F912), Sidelink communication is disconnected.

[0053] After the Sidelink communication is disconnected, the roadside device 101 deletes (discards) the Layer-2 IDs generated by F604, F804, and F904 (F613, F813, F913). Figure 13 is a sequence diagram showing the sequence of communication processing that takes place between two in-vehicle devices 103 and 105. Each on-board device 103 and 105 generates a Layer-2 ID for receiving from the characteristic information of the vehicles 102 and 104 on which it is installed (F701, F703). In the example shown in Figure 13, the on-board device 103 in vehicle A generates a Layer-2 ID for receiving, for example, "AAA". The on-board device 105 in vehicle B generates a Layer-2 ID for receiving, for example, "BBB". Each on-board device 103 and 105 starts waiting for Sidelink communication using the generated Layer-2 ID (F702, F704).

[0054] Subsequently, when the other vehicle enters the imaging range of the camera 301 of the on-board devices 103 and 105 in either vehicle A or vehicle B, features are extracted from the image captured by camera 301 (F705). Figure 13 shows an example where vehicle B enters the imaging range of the on-board device 103 in vehicle A. In the on-board device 103 of vehicle A, a Layer-2 ID for transmission is generated from the feature information indicating the extracted features of vehicle B (F706). Based on the information captured by camera 301, when the onboard device 103 of vehicle A detects an event that should be notified to vehicle B (F707), the onboard device 103 generates notification information (F708). The onboard device 103 of vehicle A requests a connection using the Layer-2 ID generated in F706 to transmit the notification information to the onboard device 105 of vehicle B (F709). The onboard device 105 of vehicle B responds to the exchange of security information if the Layer-2 ID used in the connection request matches the waiting Layer-2 ID, etc.

[0055] When the onboard device 105 of vehicle B responds to the exchange of security information, security is established between the onboard devices 103 and 105 (F710), and a connection acceptance is sent from the onboard device 105 of vehicle B to vehicle B (F711). Upon receiving the connection acceptance, the in-vehicle device 103 transmits notification information to the in-vehicle device 105 in vehicle B, and the in-vehicle device 105 in vehicle B receives the notification information (F712). Once all notification information has been sent and received, and vehicle B moves out of the field of view of the camera 301 on vehicle A's onboard device 103, vehicle A's onboard device 103 requests to disconnect Sidelink communication (F713). When vehicle B's onboard device 105 responds to the disconnection request (F714), Sidelink communication is disconnected.

[0056] After the Sidelink communication is disconnected, the onboard device 103 of vehicle A deletes the Layer-2 ID generated in F706 (F715). Next, the processing operations of each device that realizes the sequence described above will be explained with reference to the flowchart. Figure 14 is a flowchart showing the processing operation when the roadside device 101, etc., functions as a transmitting device that sends notification information. The recipients of the notification information are vehicles 102, 104, pedestrians 106, or bicycles 108. Processing begins in S1001, and when the destination is detected by cameras 201 and 301 of the roadside device 101 (S1002), the feature extraction units 206 and 306 extract the features of the destination (S1003).

[0057] If the extracted features include the vehicle numbers of vehicles 102 and 104, or bicycle 108, a Layer-2 ID including the vehicle number is generated as feature information (S1004). If the extracted features do not include the vehicle number, no Layer-2 ID is generated in S1004, and a Layer-2 ID is generated from feature information that indicates features other than the vehicle number (S1005). In S1004, for example, the Layer-2 ID shown in Figure 7 is generated, and in S1005, for example, the Layer-2 ID shown in Figure 5 is generated.

[0058] As mentioned above, vehicle license plates are a superior characteristic of the destination, so in the example in Figure 14, the vehicle license plate and other characteristics are distinguished to generate the Layer-2 ID. Note that the characteristic information used to generate the Layer-2 ID may be changed depending on the traffic conditions indicated by the notification information. In that case, multiple formats for the Layer-2 ID may be predetermined and implemented in the transmitting and receiving devices, or the format may be sent via communication.

[0059] After the Layer-2 ID is generated, if an event occurs that requires notification to the destination (S1006), notification information is generated (S1007). Furthermore, in order to send the notification information to the destination via Sidelink communication, the destination is requested to connect using the Layer-2 ID generated in S1004 and S1005 (S1008). Subsequently, the Sidelink communication security establishment operation is performed (S1009), and acceptance of the Sidelink communication connection is received from the destination (S1010).

[0060] After receiving the connection acceptance, notification information is sent to the recipient (S1011). Once all notification information has been sent and the recipient is out of the shooting range of cameras 201 and 301 (S1012; No), Sidelink communication with the recipient is disconnected (S1013). Then, the generated Layer-2 ID is deleted (S1014), and the processing operation shown in Figure 14 ends. Note that even if no event occurs to notify the recipient (S1006; No), and the recipient is out of the shooting range of cameras 201 and 301 (S1012; No), the processing operation ends via S1013 and S1014.

[0061] While the recipient is within the shooting range of cameras 201 and 301 (S1012; Yes), notification information is sent to the recipient each time an event occurs that warrants notification (S1006~S1011). Figures 15 to 17 are flowcharts illustrating the processing operations when an in-vehicle device 103 functions as a receiving device for receiving notification information. Figure 15 shows the processing operations in the in-vehicle device 103 of vehicle A, representing two in-vehicle devices 103 and 105. Figure 16 shows the processing in the communication device 107 of pedestrian 106. Figure 17 shows the processing in the communication device 109 of bicycle 108.

[0062] When the characteristics of a vehicle 102, a pedestrian 106, or a bicycle 108 are manually or automatically input into the in-vehicle device 103, characteristic information representing the input characteristics is stored in the storage unit 302 (S1101, S1201, S1301). The in-vehicle device 103 generates one or more Layer-2 IDs from the feature information. For example, the in-vehicle device 103 generates a Layer-2 ID "AAA'" that includes the vehicle number (S1102), and also generates a Layer-2 ID "AAA" that includes feature information representing features other than the vehicle number (S1103).

[0063] Furthermore, for example, the communication device 107 of pedestrian 106 generates three Layer-2 IDs "CCC", "CCC-1", and "CCC-2" corresponding to three types of characteristic information (S1202, S1203, S1204). Furthermore, for example, the communication device 109 of the bicycle 108 generates a Layer-2 ID "DDD'" that includes the vehicle number (S1302), and also generates a Layer-2 ID "DDD" that includes feature information representing features other than the vehicle number (S1303). After generating the Layer-2 ID, the in-vehicle device 103 and the like wait for a Sidelink communication connection request using the generated Layer-2 ID (S1104, S1205, S1304).

[0064] Upon receiving a connection request in S1104, S1205, and S1304, the in-vehicle device 103 establishes security for Sidelink communication (S1105, S1206, S1305) and sends a connection acceptance to the requester (S1106, S1207, S1306). Once the connection is accepted, the in-vehicle device 103 receives notification information (S1107, S1208, S1307), and after receiving the information, it returns to the standby state as described in S1104, S1205, and S1304.

[0065] In the communication system 10, notification information transmitted and received via Sidelink communication indicates, for example, the surrounding traffic conditions detected based on information from sensors and cameras. The notification information may be warning information based on future predictions, or it may be sensor data or camera images. In the communication system 10, by sending and receiving notification information, vehicles 102 and 104 can, for example, grasp not only the presence or absence of oncoming vehicles at the merging point, but also the movement of oncoming vehicles based on location information, speed information, etc., thereby enabling driver assistance.

[0066] Furthermore, since notification information in the communication system 10 can be exchanged with low latency via Sidelink communication, it becomes possible for vehicles 102 and 104 to take measures such as controlling the order of merging and emergency brake control. Furthermore, by sending and receiving notification information, vehicles 102 and 104 can, for example, become aware in advance of road traffic information such as accidents, congestion, emergency vehicles, construction vehicles, and vehicles driving erratically, as well as the movements of pedestrians 106 and bicycles 108, enabling safer driving. In the communication system 10, pedestrians 106 and cyclists 108 can learn in advance about dangerous movements of vehicles 102 and 104 around them through the sending and receiving of notification information, thereby reducing the possibility of being involved in an accident.

[0067] (Other embodiments) The present invention can take the form of, for example, a system, apparatus, method, program, or recording medium (storage medium). Specifically, it may be applied to a system consisting of multiple devices (for example, a host computer, interface devices, a web application, etc.), or to an apparatus consisting of a single device.

[0068] Furthermore, the present invention can also be realized by supplying a program (computer program) that implements one or more of the functions of the embodiments described above to a system or device via a network or recording medium (storage medium). One or more processors in the computer of that system or device read and execute the program. In this case, the program (program code) read from the recording medium itself implements the function of the embodiment. Moreover, the recording medium on which the program is recorded can constitute the present invention.

[0069] Furthermore, the functionality of the embodiment may be realized not only by the computer executing the program it has read, but also by the operating system (OS) running on the computer performing some or all of the actual processing based on the program's instructions, thereby realizing the functionality of the embodiment described above.

[0070] Furthermore, after the program read from the recording medium is written to the memory of a function expansion card inserted into the computer or a function expansion unit connected to the computer, the CPU or other components of the function expansion card or function expansion unit may perform some or all of the actual processing based on the instructions of the program, thereby realizing the functions of the embodiment described above. When the present invention is applied to the above-mentioned recording medium, the recording medium will store a program corresponding to the flowchart described above.

[0071] Furthermore, the disclosure of the above embodiments includes the following configurations and methods. (Composition 1) An extraction means for extracting characteristics of the destination that are visible in the captured image from the captured image, A generation means for generating a Layer-2 ID that includes feature information indicating the aforementioned features, A transmission means that transmits information via Sidelink communication using the aforementioned Layer-2 ID, A communication device characterized by comprising: (Configuration 2) A storage means for storing features that can be extracted from captured images of the mounted object on which the device is installed, A receiving means that receives information via Sidelink communication using a Layer-2 ID containing feature information that exhibits the aforementioned features, A communication device characterized by comprising: (Composition 3) The communication device according to configuration 2, characterized by comprising a generation means for generating the Layer-2 ID. (Composition 4) The aforementioned Sidelink communication is Sidelink communication (PC5) as defined by 3GPP. The communication device according to any one of configurations 1 to 3, characterized in that the Layer-2 ID is an identifier indicating the destination of communication in Sidelink communication as defined by 3GPP. (Composition 5) The communication device according to any one of configurations 1 to 4, characterized in that, as a feature of the above, at least one of the following is used in a vehicle: vehicle number, vehicle type, body shape, body color, direction of travel, speed, position, number of occupants, state of illumination of turn signal lamps, and state of illumination of brake lamps. (Composition 6) The communication device according to configuration 5, characterized in that a vehicle number is used as one of the aforementioned features. (Composition 7) The communication device according to any one of configurations 1 to 4, characterized in that, as a feature, at least one of the following is used for a pedestrian: clothing, hairstyle, skin color, gender, walking direction, speed, and position. (Composition 8) The communication device according to any one of configurations 1 to 4, characterized in that, as a feature, at least one of the following is used in relation to a bicycle: vehicle type, body shape, number of wheels, body color, rider's clothing, rider's clothing color, direction of travel, speed, and position. (Composition 9) The communication device according to configuration 2 or 3, wherein the receiving means receives information using the Layer-2 ID when all or part of the multiple feature information items are feature information indicating the characteristics of the mounted object. (Composition 10) The communication device according to configuration 1, characterized in that the Layer-2 ID is discarded after the transmission of the aforementioned information. (Composition 11) A communication system characterized by comprising the communication device described in Configuration 1 and the communication device described in Configuration 2. (Method 1) An extraction step to extract the characteristics of the recipient that are visible in the captured image from the captured image, A generation step of generating an ID that includes feature information showing the aforementioned features, A transmission step of sending information to the recipient using the ID, A method for controlling a communication device, characterized by having the following features. (Composition 12) A program for causing a computer to function as one of the means of a communication device described in any one of configurations 1 to 10. [Explanation of symbols]

[0072] 10...Communication systems, 20...Intersections, 101...Roadside equipment, 102, 104... Vehicles, 103, 105... On-board equipment, 106...Pedestrians, 108...Bicycles, 107, 109...Portable communication devices 201...Camera, 202, 302...Memory unit, 203, 303...Control unit, 204, 304... Situation Judgment Unit, 205, 305... ID Generation Unit, 206, 306... Feature extraction unit, 207, 307... Wireless communication unit, 208...Wired communication unit, 209...Sensor, 308...Movement information acquisition unit, 309...Operation unit, 310...Display unit

Claims

1. The method of taking an image is, An extraction means for extracting characteristics of the transmission destination from the captured image captured by the aforementioned shooting means, A generation means for generating a Layer-2 ID that includes feature information indicating the aforementioned features, A transmission means that transmits information using Sidelink communication with the aforementioned Layer-2 ID, A communication device characterized by comprising:

2. A storage means for storing features that can be extracted from captured images of the mounted object on which the device is installed, Sidelink communication using a Layer-2 ID containing feature information that exhibits the aforementioned features. A receiving means for receiving information, A communication device characterized by comprising:

3. The communication device according to claim 2, characterized by comprising a generation means for generating the Layer-2 ID.

4. The aforementioned Sidelink communication is Sidelink communication (PC5) established by 3GPP (3rd Generation Partnership Project) (registered trademark), The communication device according to any one of claims 1 to 3, characterized in that the Layer-2 ID is an identifier indicating the destination of communication in Sidelink communication as defined by the 3GPP.

5. The communication device according to claim 1 or 2, characterized in that, as a feature of the above, at least one of the following is used in a vehicle: vehicle number, vehicle type, body shape, body color, direction of travel, speed, position, number of occupants, state of illumination of turn signal lamps, and state of illumination of brake lamps.

6. The communication device according to claim 5, characterized in that a vehicle number is used as the aforementioned feature.

7. The communication device according to claim 1 or 2, characterized in that, as a feature, at least one of the following is used for a pedestrian: clothing, hairstyle, skin color, gender, walking direction, speed, and position.

8. The communication device according to claim 1 or 2, characterized in that, as a feature, at least one of the following is used for a bicycle: vehicle type, body shape, number of wheels, body color, rider's clothing, rider's clothing color, direction of travel, speed, and position.

9. The communication device according to claim 2 or 3, wherein the receiving means receives information using the Layer-2 ID, which includes a plurality of the feature information, when all or part of the plurality of feature information is feature information indicating the characteristics of the mounted body.

10. The communication device according to claim 1, characterized in that the Layer-2 ID is discarded after the transmission of the aforementioned information.

11. A communication system comprising the communication device described in claim 1 and the communication device described in claim 2.

12. The process involves taking a picture, and the shooting steps are as follows: An extraction step is performed to extract characteristics of the destination from the captured image taken in the aforementioned shooting step, A generation step of generating an ID that includes feature information showing the aforementioned features, A transmission step of sending information to the recipient using the ID, A method for controlling a communication device, characterized by having the following features.

13. A program for causing a computer to function as each of the means of the communication device described in claim 1 or 2.

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