JP2019126018A - Vehicle radio communication system - Google Patents

Abstract

To reduce traffic by efficiently using network resources and thereby shorten a communication delay time when a mesh network is formed by installing a large number of radio communication terminals on a vehicle.SOLUTION: When each radio communication terminal transmits data, a vehicle radio communication system determines priority according to a type of transmission target data, selects a wide-area radio communication function if the priority is high, selects a narrow-area radio communication function if the priority is low, and performs radio communication. The high or low priority of each piece of data is variable according to a change in situation such as emergency. Also in the case where each radio communication terminal relays data, the vehicle radio communication system determines priority according to a type of data, and selects either wide-area radio communication or narrow-area radio communication. The wide-area radio communication and narrow-area radio communication are different in communication format from each other. The priority of data changes according to destinations.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a wireless communication system for a vehicle, and more particularly to a technique for wirelessly communicating between a plurality of wireless communication terminals mounted on a vehicle.

  For example, by connecting various devices on a vehicle via a wired or wireless mesh network, it is possible to communicate with each other using various routes as needed. In addition, when using wireless communication, the structure of the wire harness can be simplified by the amount of the route, and the burden of wiring operation of the wire harness can be reduced.

  In addition, in the case of configuring a mesh network, it is possible to selectively use various routes from one source node to another destination node to secure a communication route. Therefore, even if a path that can not be used due to a failure or the like occurs, it is possible to switch to another path and continuously connect. For example, if dynamic routing is used, the route used for communication can be changed each time on the mesh network, so that it is less susceptible to failure or the like.

  Further, for example, in the communication between an information processing apparatus having a plurality of communication methods and an image forming apparatus, Patent Document 1 switches to a better communication method when it finds a preferable communication method as compared to the communication method in use. It shows a technology for shortening communication time.

  Further, the data communication apparatus of Patent Document 2 shows a technology for performing data communication at an appropriate communication speed for each communication application. Specifically, the communication method used for data communication specified by the communication method specifying unit based on the communication application that issued the data communication start request by monitoring the operation of the application execution unit and the connection state of each communication processing unit The communication speed used for data communication is determined by referring to the communication speed setting table based on the wired / wireless communication).

  Further, Patent Document 3 shows a technique for rapidly transmitting data to a target node in a communication system including a plurality of nodes. Specifically, each node A to D transmits direct communication data including data to the destination node when a request for transmitting data to the destination node occurs. Also, when direct or proxy communication data addressed to the own node is received, an ACK indicating that it has been received is transmitted. Also, when direct communication data not addressed to the own node is received and then ACK can not be received, proxy communication data including data included in the direct communication data is transmitted. Furthermore, after transmitting the proxy communication data, when an ACK is received, a proxy communication completion notification is transmitted to the transmission source of the communication data directly.

  Further, Patent Document 4 shows a technique for enabling communication in an area covered by a small base station when the small base station can not communicate due to a failure or the like. Specifically, it is shown that a base station control device that controls a plurality of base stations detects an abnormality of each small base station and changes output radio waves of other base stations.

JP, 2011-49639, A JP-A-11-127218 JP 2014-225859 A JP, 2015-192405, A

  For example, a case where a large number of wireless communication terminals having a relatively narrow communicable range are arranged in various positions in a distributed state, and a mesh wireless communication network is simply configured using these wireless communication terminals Suppose. In this case, when data is transmitted from a wireless communication terminal of one transmission source node to a wireless communication terminal of another destination node, transmission is performed while communicating sequentially or in parallel between various terminals. It is necessary to perform communication processing to search for a route available for communication from the source to the destination. Furthermore, even after a route available for communication has been determined, this data passes through a large number of relay points before the data reaches the destination from the transmission source. Thus, traffic passing over the wireless communication network is increased. Also, as the number of data relays from the source to the destination increases, the delay time of communication also increases.

  For example, in the case where a plurality of communication methods are provided as in Patent Document 1, communication time can be shortened by automatically selecting a better communication method. However, in the case of adopting the technology of Patent Document 1, it is necessary to secure resources such as hardware so that a plurality of communication methods can always be used with the same communication partner, which increases the cost of the apparatus. Are concerned. In particular, in the case of an in-vehicle system, the number of wireless communication terminals may be increased, which may significantly increase the cost of the entire system. In addition, when resources such as hardware are insufficient, necessary communication performance may not be obtained.

  When the technology of Patent Document 2 is adopted, the communication speed can be optimized by reflecting not only the difference in wired / wireless communication but also the difference in communication application which has requested the start of communication. However, complicated control is required because the status of various communication applications must be monitored.

  In the case of adopting the technology of Patent Document 3, secure communication paths even when there is an obstacle between the transmission source node and the destination node by using direct communication and proxy communication properly. Becomes easier. However, traffic passing over the wireless communication network may increase. Also, as the number of data relays from the source to the destination increases, the delay time of communication also increases.

  Moreover, particularly in the case of a wireless communication system used on a vehicle, there may be a large number of wireless communication terminals used for controlling various types of electrical components in a limited narrow space on the vehicle. is there. Furthermore, it is necessary to consider in advance that radio waves of wireless communication performed on the host vehicle do not affect wireless communication in another vehicle or wireless communication outside the vehicle. Therefore, it is desirable to suppress the output power of radio waves transmitted by each wireless communication terminal on the vehicle, and to perform narrow-range wireless communication in a narrower range than the entire vehicle. However, if the communicable range of each wireless communication terminal is limited to a very narrow range, the increase in traffic and the increase in communication delay time become major problems as described above. Furthermore, there is a need to suppress the increase in cost of the communication system.

  In addition, in case of adopting a technology as disclosed in Patent Document 4 in preparation for failure of a wireless device such as a base station, a dedicated control station must be added, and control of an antenna and control of output radio wave intensity There is also the problem of becoming complicated.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to efficiently use network resources when traffic is installed on a vehicle to form a mesh network. It is an object of the present invention to provide a wireless communication system for a vehicle capable of reducing the amount of communication delay time generated on the network while suppressing the amount.

In order to achieve the above-mentioned object, the vehicle radio communication system according to the present invention is characterized by the following (1) to (7).
(1) A plurality of wireless communications having a wide area wireless communication function mounted on a vehicle and capable of wireless communication on the vehicle, and a narrow area wireless communication function having a narrower area capable of wireless communication than the wide area wireless communication function Equipped with a terminal,
When each wireless communication terminal transmits data, the priority is specified according to the type of transmission target data,
When the priority of the transmission target data is high, at least the wide area wireless communication function is selected, and when the priority of the transmission target data is low, at least the narrow area wireless communication function is selected to perform wireless communication.
A wireless communication system for a vehicle, characterized in that

  According to the wireless communication system for vehicles of the configuration of the above (1), when each wireless communication terminal transmits data, which one of the wide-area wireless communication function and the short-range wireless communication function is to be selected for communication is It can be automatically determined based on the type of transmission target data. Therefore, for example, when transmitting high priority data required to shorten the delay time of communication as much as possible, selecting the wide area wireless communication function reduces the number of times of relaying data from the transmission source to the destination. The delay time can be reliably reduced. Moreover, when transmitting low priority data, it is not necessary to shorten the delay time, so the short-range wireless communication function can be selected for communication. In addition, in the case where the transmission source and the destination are the same and the same type of data is transmitted, only one of the wide-area wireless communication function and the short-range wireless communication function needs to be secured. It can be assigned to other communications. In other words, limited resources can be used effectively. This also reduces the amount of traffic sent to the network.

(2) Each of the wireless communication terminals switches the priority according to the type of transmission target data according to the change of the situation.
The wireless communication system for a vehicle according to the above (1), characterized in that

  According to the wireless communication system for vehicles of the above configuration (2), even the same type of data can be switched to increase or decrease the priority according to the change of the situation. For example, when the vehicle is in a normal driving condition, the safety of the driving needs to be emphasized, so the data related to the devices of the steering system is prioritized, and the data related to the opening / closing of the door and the devices of the power window It is assumed that the priority of is lower. On the other hand, in the case of an emergency such as when a vehicle encounters a traffic accident, it is necessary to place emphasis on the escape function rather than the driver's operation. It is assumed that the priority of the data related to the equipment of the power window is high.

(3) Each of the wide area wireless communication function and the short range wireless communication function includes a transmission / reception function,
Each of the wireless communication terminals has a destination identification function for identifying whether the received data is addressed to the own node, and a wireless relay function for wirelessly transmitting received data other than for the own node to the destination.
When the wireless relay function transmits data, the priority is specified according to the type of transmission target data, and when the priority of the transmission target data is high, at least the wide area wireless communication function is selected, and the transmission target is selected. When the priority of data is low, at least the short-range wireless communication function is selected to perform wireless communication,
The wireless communication system for a vehicle according to (1) or (2) above, characterized in that

  According to the vehicle radio communication system configured as described in (3) above, even when each radio communication terminal receives data not addressed to its own node from another radio communication terminal and performs radio relay toward the destination, wide area radio communication It is possible to automatically determine which one of the function and the short range wireless communication function to select and communicate based on the type of data to be transmitted.

(4) The wide area wireless communication function uses a first wireless communication format suitable for wide area communication,
The short range wireless communication function uses a second wireless communication format suitable for short range communication.
A vehicle radio communication system according to any one of the above (1) to (3), characterized in that

  According to the vehicle radio communication system of the configuration of (4), the wide area radio communication function and the narrow area radio communication function are realized in different radio communication formats, so that the entire system can be optimized. . For example, even if there is an obstacle on the communication path, the entire area of the vehicle can be obtained by the wide area wireless communication function by adopting a communication method in which radio waves easily reach the target terminal due to radio wave diffraction etc. as the first radio communication format. It will be easier to cover. Also, for example, by adopting a communication method with high interference performance and capable of high-speed communication as the second wireless communication format, when performing communication with the narrow-area wireless communication function, a large number of wireless within a narrow range in the vehicle Even in an environment where communication terminals are arranged, wireless communication can be reliably performed.

(5) A plurality of wireless communications having a wide area wireless communication function mounted on a vehicle and capable of wireless communication on the vehicle, and a narrow area wireless communication function having a narrower area capable of wireless communication than the wide area wireless communication function Equipped with a terminal,
When each wireless communication terminal transmits data, while grasping the degree of urgency in the own vehicle, at least the priority reflecting the difference in the type of transmission target data is specified,
According to the degree of urgency and the priority, one of the wide area wireless communication function and the narrow area wireless communication function is preferentially selected to perform wireless communication.
A wireless communication system for a vehicle, characterized in that

  According to the wireless communication system for a vehicle having the configuration of (5), in addition to the difference in the type of transmission target data, either wide area wireless communication or narrow area wireless communication is preferentially selected in consideration of the degree of urgency can do. Therefore, appropriate selection can be made in an emergency such as occurrence of an accident of the host vehicle or a failure of the wireless device. Further, since each wireless communication terminal can autonomously carry out selection, there is no need to add a special control station.

(6) In an emergency including occurrence of an accident of the own vehicle, when each wireless communication terminal transmits data, wireless communication is performed by preferentially selecting the wide area wireless communication function based on the degree of urgency.
The wireless communication system for vehicles as described in said (5).

  According to the vehicle radio communication system of the above configuration (6), since the wide area radio communication function is preferentially selected in an emergency, the communication delay time can be shortened. Therefore, even when transmitting low priority data, it is possible to transmit with reduced communication delay time in an emergency such as an accident occurrence.

(7) When each wireless communication terminal transmits data, if the communication path to the destination can not be secured by the communication of the narrow area wireless communication function, the wide area wireless communication function is selected based on the degree of urgency Select the priority and perform wireless communication,
The wireless communication system for vehicles as described in said (5).

  According to the wireless communication system for vehicles of the above configuration (7), switching to the wide area wireless communication function even when the communication path to the destination can not be secured due to the influence of a failure of some of the wireless communication terminals. Enables communication.

  According to the wireless communication system for a vehicle of the present invention, when a large number of wireless communication terminals are installed on a vehicle to form a mesh network, network resources are efficiently used to suppress the traffic amount, and on the network It is possible to reduce the communication delay time that occurs in

  The present invention has been briefly described above. Furthermore, the details of the present invention will be further clarified by reading the modes for carrying out the invention described below (hereinafter referred to as "embodiments") with reference to the attached drawings. .

FIG. 1 is a plan view showing a specific example of the arrangement of a plurality of wireless communication terminals and the configuration of a wireless communication line included in a wireless communication system for a vehicle according to an embodiment of the present invention. FIG. 2 is a schematic view showing a configuration example of a network in the vehicle radio communication system according to the embodiment of the present invention. FIG. 3 is a block diagram showing a configuration example of one wireless communication terminal used by the wireless communication system for a vehicle according to the embodiment of the present invention. FIG. 4 is a flowchart showing an outline of data priority determination processing in the wireless communication terminal at each node position. FIG. 5 is a flowchart showing an outline of transmission processing in the wireless communication terminal at each node position. FIG. 6 is a flowchart showing an outline of reception processing in the wireless communication terminal at each node position. FIG. 7 is a schematic view showing a configuration example of data transmitted and received by the wireless communication terminal at each node position. FIG. 8 is a flowchart showing a modification of the data priority determination process. FIG. 9 is a flowchart showing a modification of the transmission process. FIG. 10 is a flowchart showing a modification of the transmission process. FIG. 11 is a flowchart showing a modification of the reception process.

Specific embodiments of the present invention are described below with reference to the figures.
<Specific Example of Arrangement of Terminals and Configuration of Wireless Communication Line>
A specific example regarding the arrangement of the plurality of wireless communication terminals and the configuration of the wireless communication line included in the wireless communication system for a vehicle according to the embodiment of the present invention is shown in FIG.

  The entire area ARL of the rectangular shape shown in FIG. 1 corresponds to the area of the vehicle structure of a general automobile. FIG. 1 shows the arrangement of each element in a plane of the vehicle structure as viewed from above. The left end side of FIG. 1 represents the front side of the vehicle, and the right end side of FIG. 1 represents the rear side of the vehicle.

  In the example shown in FIG. 1, a large number of wireless communication terminals 10-1, 10-3,..., 10-17 are installed in the entire area ARL, that is, in each part of the vehicle structure and the area adjacent thereto. The positions and the total number of installation of each of the wireless communication terminals 10-1 to 10-17 are changed as necessary.

  Each of these wireless communication terminals 10-1 to 10-17 requires various electric components mounted on each part of this automobile, such as an electronic control module (ECU), various sensors, various switches, various loads, etc. It is provided to enable transmission and reception of signals by wireless communication.

  In the example shown in FIG. 1, by using the wireless communication functions of the wireless communication terminals 10-1 to 10-17, wireless communication paths C01, C03, C04,. can do. Further, in the example shown in FIG. 1, a plurality of small cell regions ARS1, ARS2, and ARS3 sufficiently smaller than the entire region ARL are formed in the space inside the entire region ARL. Of course, the number, size, position, etc. of each wireless communication path, each small cell area, etc. are changed as needed.

  In addition, the small cell regions ARS1 and ARS2 adjacent to each other are formed in a state in which parts thereof overlap each other. The same applies to the small cell areas ARS2 and ARS3 adjacent to each other. The radio communication terminals 10-3, 10-4 and 10-8 are disposed inside the small cell area ARS1, and the radio communication terminals 10-8 and 10-11 are disposed inside the small cell area ARS2, and the small cell The radio communication terminals 10-12, 10-13, and 10-15 are disposed inside the area ARS3.

  Each of the radio communication terminals 10-1 to 10-17 shown in FIG. 1 is narrow in a relatively small area as in the range of any of small cell areas ARS1 to ARS3 shown in FIG. It is compatible with both area wireless communication and relatively large wide area wireless communication within the range corresponding to the entire area ARL.

  In the present embodiment, “wide area” is assumed to be, for example, about 3 meters in size, and “narrow area” is assumed to be, for example, about 1 meter in size. Accordingly, it is possible to suppress that radio waves transmitted by the vehicle radio communication system in the own vehicle affect radio communication in another vehicle and various radio communications outside the other vehicle.

<Example of network configuration>
An exemplary configuration of a network in a vehicle radio communication system according to an embodiment of the present invention is shown in FIG. That is, a wireless communication network as shown in FIG. 2 can be formed by using the wireless communication terminals 10-1 to 10-17 shown in FIG.

  In the network shown in FIG. 2, four different small cell areas AR-A, AR-B, AR-C, and AR-D are formed. Here, the two small cell areas AR-A and AR-B adjacent to each other are in a partially overlapped state. The same applies to two small cell areas AR-B and AR-C adjacent to each other. The same applies to two small cell areas AR-C and AR-D adjacent to each other.

  In the example of FIG. 2, the small cell area AR-A corresponding to the group A includes three nodes NA-1, NA-2, and NA-3. In addition, the small cell area AR-B corresponding to the B group includes four nodes NB-1, NB-2, NB-3, and NB-4. Further, the small cell area AR-C corresponding to the C group includes four nodes NC-1, NC-2, NC-3, and NC-4. Also, the small cell area AR-D corresponding to the D group includes three nodes ND-1, ND-2, and ND-3.

  Among the nodes shown in FIG. 2, the node NA-3 in the small cell area AR-A and the node NB-1 in the small cell area AR-B are common, and are configured by one wireless communication terminal 10 Ru. The same applies to the node NB-4 of the small cell area AR-B and the node NC-1 of the small cell area AR-C. The same applies to the node NC-4 of the small cell area AR-C and the node ND-1 of the small cell area AR-D. Also, the other nodes NA-1, NA-2, NB-2, NB-3, NC-2, NC-3, ND-2 and ND-3 are each configured by one wireless communication terminal 10. .

  In the example of FIG. 2, the nodes NA-1 to NA-3 in the small cell area AR-A are arranged in a state where they can be connected to each other by a wireless communication line. The same applies to each of the nodes NB-1 to NB-4 in the small cell area AR-B. The same applies to each of the nodes NC-1 to NC-4 in the small cell area AR-C. The same applies to each of the nodes ND-1 to ND-3 in the small cell area AR-D.

  Further, since the node NA-3 and the node NB-1 are common, the communication path between the small cell areas AR-A and AR-B adjacent to each other can be obtained by passing through the common node. It can be secured. Similarly, since the node NB-4 and the node NC-1 are common, a communication path can be secured between the small cell areas AR-B and AR-C adjacent to each other. Further, since the node NC-4 and the node ND-1 are common, a communication path can be secured between the small cell areas AR-C and AR-D adjacent to each other.

  In the present embodiment, the radio communication terminal 10 disposed at the position of each node has a wide area corresponding to the entire area ARL, in addition to the narrow area radio communication corresponding to the small cell areas AR-A to AR-D. It also has a function to perform range wireless communication. Therefore, all the nodes inside the entire area ARL can wirelessly communicate with each other without necessarily providing the above common node.

<Network design method>
When actually designing the communication network as shown in FIG. 2, for example, the radio communication terminals 10-1 to 10-17 shown in FIG. 1 are divided into a plurality of groups, and each group is It corresponds to one of the small cell areas AR-A to AR-D shown in FIG. Then, the network is configured to mutually connect a plurality of adjacent small cell areas AR-A to AR-D. The connection relationship between the plurality of small cell areas is determined in advance. In addition, it is desirable to create a group so as to include one or more nodes that span multiple small cell areas. Then, for each of the small cell regions AR-A to AR-D, route design is performed only in the cell. Path design in a cell can be handled automatically by using, for example, a “dynamic routing” procedure.

<Example of general communication operation on network>
In the communication network shown in FIG. 2, a general operation example will be described below on the assumption that data is transmitted from the transmission source node NA-1 to the node ND-2. However, in the case of the system of the present embodiment, a special operation different from the operation shown below can be performed. This will be explained later.

1. Since the destination is communication of the node ND-2 at the node NA-1, the small cell region AR-A which is the own cell is connected to the small cell region AR-D including the destination via AR-B and AR-C. Make sure. Here, when the connection between the small cell areas AR-A, AR-B, AR-C, and AR-D is fixed, for example, the connection is made by referring to the information held in a predetermined table. You can check When the connection between the small cell areas AR-A, AR-B, AR-C, and AR-D is variable, for example, control is performed so that the latest state is periodically grasped and reflected in the table. Just do it.

2. In order to transfer data to the small cell area AR-D including the destination node, first, it is necessary to transmit data to the small cell area AR-B adjacent to the own cell. A communication path to a node NA-3 existing at a position crossing the cell areas AR-A and AR-B is created. Specifically, triggered by the operation of the transmission source node NA-1, the procedure of "dynamic routing" is executed in the small cell area AR-A, the connection of each node in this cell is confirmed, and communication is performed. Appropriate routes available are automatically created.

3. Each node in the small cell area AR-A transfers the transmission data output from the node NA-1 to the node NA-3 according to the route created by the above process.

4. Here, since the node NA-3 is common to the node NB-1, based on the transmission data received by the node NB-1, in the small cell area AR-B, the same as the above "2." and "3." Perform the action of Thus, a path from node NB-1 to node NB-4 is created in small cell area AR-B, and transmission data of node NB-1 is transferred to node NB-4 using this path. .

5. Further, since the node NB-4 is common to the node NC-1, based on the transmission data received by the node NC-1, in the small cell area AR-C, the same as the above "2." and "3." Do the action. Thus, a path from the node NC-1 to the node NC-4 is created in the small cell area AR-C, and transmission data of the node NC-1 is transferred to the node NC-4.

6. Further, since the node NC-4 is common to the node ND-1, the procedure of "dynamic routing" is executed in the small cell area AR-D based on the transmission data received by the node ND-1 and this cell The connection of each node in the network is confirmed, and an appropriate path available for communication is automatically created. Based on this path, the path from the node ND-1 to the destination node ND-2 is specified in the small cell area AR-D, and the transmission data of the node ND-1 is transferred to the node ND-2.

  When the destination node sends data back to the source node, the data is transmitted in the reverse direction using the same route as when the source sends data to the destination. In addition, the processing for creating the above-mentioned path in each cell may be performed in advance, and the information obtained as a result may be held by each node. In that case, when transferring actual transmission data, the time required to create the above path is significantly reduced.

  In the communication network as shown in FIG. 2, since a large number of nodes can be used as needed, various routes are selectively used to secure a communication route from a data transmission source to a transmission destination (destination). It is possible. However, since there are many correspondent nodes that can communicate, the efficiency in searching for a route and in transmitting data actually decreases. That is, when carrying out a route search in a state where the communication route has not been determined, it is necessary to transmit signals such as packets to the other nodes of the routes that can not actually be used, so When the number of traffic increases, unnecessary traffic increases, the load of communication processing on the network increases, and the signal transmission delay time increases. In addition, even after the communication path is determined, the number of nodes relaying the signal on the communication path increases, so that the transmission delay time of the signal increases.

  However, in the system according to the present embodiment, in addition to the function in which each wireless communication terminal 10 performs wireless communication in the range of each small cell area AR-A to AR-D, the function in which wireless communication is performed in the range of entire area ARL Have. Therefore, for example, when node NA-1 in small cell region AR-A transmits data to node ND-2 in small cell region AR-D as a destination, the small cell region from within small cell region AR-A It is also possible to transmit directly wirelessly to each node in AR-D. When the communication path is appropriately changed using this function, the number of relays in the path between the transmission source and the destination is reduced, and the delay time of transmission data is reduced. Also, the traffic generated on the network can be reduced.

<Configuration Example of Wireless Communication Terminal>
An exemplary configuration of one radio communication terminal 10 used by the vehicle radio communication system according to the embodiment of the present invention is shown in FIG. The wireless communication terminal 10 shown in FIG. 3 includes a wide area communication module 21, a short range communication module 22, a communication success determination function 23, a reception destination determination function 24, a reception data output function 25, an output interface (I / F) 26, and an input. An interface 27, a communication data creation function 28, a transmission destination determination function 29, a priority determination function 30, a route detection / construction function 31, and antennas 32 and 33 are provided.

  In addition, the wide area communication module 21 includes a wide area wireless reception function 21a and a wide area wireless transmission function 21b, and the narrow area communication module 22 includes a narrow area wireless reception function 22a and a narrow area wireless transmission function 22b.

  Each function of the wireless communication terminal 10 shown in FIG. 3 can be configured using dedicated hardware, or the minimum necessary hardware including a microcomputer and software executed by the microcomputer It can also be realized using.

  The wide-area wireless reception function 21a and the wide-area wireless transmission function 21b cover the entire inside of the vehicle, for example, between the source terminal and the destination terminal without relaying anywhere within the entire area ARL shown in FIG. The wireless communication system has a function of receiving and transmitting a wireless signal in a wireless communication format having a characteristic that direct wireless communication can be performed. Specifically, even if there is an obstacle on the communication path, a communication format is used in which the transmitted radio waves easily reach the target terminal by radio wave diffraction or the like. Further, the transmission output of the wide-area wireless transmission function 21b is set relatively large so that radio waves can reach anywhere in the entire area ARL.

  On the other hand, the short range wireless reception function 22a and the short range wireless transmission function 22b are wireless between terminals within a range smaller than the entire region ARL, for example, any of the small cell regions ARS1 to ARS3 shown in FIG. It has a function of receiving and transmitting a signal. The wireless communication format adopted by the short range wireless reception function 22a and the short range wireless transmission function 22b is different from the wide range wireless reception function 21a and the wide range wireless transmission function 21b, and has a characteristic suitable for a small cell. That is, a communication format suitable for high-speed communication or high interference capability is used so that communication can be reliably performed in a small area. Further, since the communication area of the short range wireless communication is smaller than that of the wide range wireless communication, the transmission output of the short range wireless transmission function 22b is restricted to be smaller than that of the wide area wireless transmission function 21b.

The communication success determination function 23 determines whether the communication is successful or not from the reception data of the wide area radio reception function 21a or the short range radio reception function 22a.
The reception destination determination function 24 determines whether the received data input from the wide-area wireless reception function 21a or the short-range wireless reception function 22a is addressed to the own terminal.

  If the data received by wireless communication is data destined for the own terminal, the received data output function 25 outputs this data to the outside via the output interface 26. For example, a device such as an electronic control module (ECU) mounted on the host vehicle is connected to the output interface 26, and received data is passed to application software or the like operating on the ECU.

  It is possible to connect to the input interface 27 various in-vehicle devices capable of outputting data. For example, a device that outputs data representing the state of electrical components such as a door switch, a window open / close switch, a horn, a radio switch, a seat belt sensor, a steering sensor, and a wiper switch is connected to the input interface 27 as necessary.

  The communication data generation function 28 generates communication data by adding information necessary for communication based on data input to the wireless terminal from the in-vehicle device via the input interface 27. For example, the communication data creation function 28 creates communication data of a frame configuration as shown in FIG. The signal of the frame configuration shown in FIG. 7 includes a transmission source address As1, a transmission destination address Ar1, a transmission source address As2, a transmission destination address Ar2, a data type k1, data D, and an error check code.

  The source address As2 stores the address of the node where the data transmission request has been generated, and the destination address Ar2 stores the address of the destination node (destination) of the data transmission. Further, the addresses of the transmission source and the transmission destination node of the actual communication are stored in the transmission source address As1 and the transmission destination address Ar1, respectively. Further, the main body of data transmitted by the transmission source is stored in data D. The data type k1 represents, for example, information such as the type and ID of the on-vehicle device from which the data D has been sent.

  The transmission destination determination function 29 determines the transmission destination of the data based on the communication data input from the communication data generation function 28.

  The priority determination function 30 determines the priority of the communication data based on the input communication data and the information of the transmission destination determined by the transmission destination determination function 29. Further, based on the determined priority of the communication data, the priority determination function 30 selects one of wide area wireless communication and narrow area wireless communication as communication means used for transmitting the communication data. Details will be described later.

  The route detection / construction function 31 determines the wireless communication route from the destination information of the communication data, when the priority determination function 30 selects the short range wireless communication. In addition, about the path | route which can be utilized in the small cell to which the node of an own terminal belongs, it can also be defined beforehand, For example, it can also be automatically determined by "dynamic routing."

  The antenna 32 is connected to the wide area wireless reception function 21 a and the wide area wireless transmission function 21 b. The antenna 33 is connected to the short range wireless reception function 22 a and the short range wireless transmission function 22 b. That is, when the wide area communication module 21 performs the wide area wireless communication, the antenna 32 suitable for the wide area wireless communication is used, and when the narrow area communication module 22 performs the short area wireless communication, the antenna suitable for the narrow area wireless communication Use 33.

<Description of Characteristic Operation of Wireless Communication Terminal 10>
<Determination of data priority>
An outline of data priority determination processing in the radio communication terminal 10 at each node position is shown in FIG. That is, when data to be transmitted is input from the reception destination determination function 24 or the transmission destination determination function 29 to the priority determination function 30, the priority determination function 30 executes the data priority determination process shown in FIG. . The operation of FIG. 4 will be described below.

  The priority determination function 30 identifies the type k1 of the input transmission target data in S11. It is assumed that this type k1 is information that can specify an on-vehicle device corresponding to transmission target data such as a door switch, window open / close switch, horn, radio switch, seat belt sensor, steering sensor, wiper switch, etc. Be done.

  In practice, the communication data created by the communication data creation function 28 and the communication data received by the wide area radio reception function 21a or the short range radio reception function 22a include information of the data type k1 as shown in FIG. Since it is possible to identify the type k1 from this communication data.

  Also, the priority determination function 30 specifies the destination k2 of the input transmission target data in S12. In the communication data input from the reception destination determination function 24 or the transmission destination determination function 29 to the priority determination function 30, as shown in FIG. 7, information representing a node of a transmission destination (destination) as "transmission destination address Ar2" include. Therefore, the priority determination function 30 can extract and acquire the information of the destination k2 from the input communication data.

  The priority determination function 30 can refer to, for example, a priority table TB1 prepared in advance. In the present embodiment, the priority table TB1 holds information on priorities determined in advance for each of various combinations of the data type k1 and the destination k2.

  Therefore, the priority discrimination function 30 refers to the priority table TB1 with the destination k2 identified in the classification k1 and S12 identified in S11 as a parameter, and the priority Px corresponding to the combination of k1 and k2 in S13 the priority table Acquire from TB1. That is, based on the information of the type of data and the destination, an appropriate priority Px for the corresponding communication data is determined.

<Outline of transmission processing>
An outline of transmission processing in the radio communication terminal 10 at each node position is shown in FIG. That is, when each wireless communication terminal 10 transmits data input to the interface 27 as a wireless signal to terminals of other nodes according to a transmission request input from the interface 27, the priority of the corresponding transmission target data is determined. For this purpose, the priority determination function 30 executes the transmission process (Send) shown in FIG.

  In step S21, the priority discrimination function 30 compares the priority Px of the communication data to be transmitted with the predetermined priority reference value Pr. Here, the priority Px of communication data is a value determined in S13 of FIG.

  If the priority Px of the communication data is larger than the priority reference value Pr, the priority determination function 30 selects the wide area communication module 21 as the wireless communication means used to transmit the communication data in S22.

  If the priority Px of the communication data is equal to or less than the priority reference value Pr, the priority discrimination function 30 detects the route in S23 in order to specify the communication path in the case of transmitting this communication data by narrow area wireless communication. An instruction is given to the construction function 31. The route detection / construction function 31 obtains a communication path suitable for delivering the corresponding communication data to the designated destination according to the instruction of the priority determination function 30. In addition, the priority determination function 30 selects the short range communication module 22 in S24 as the wireless communication means used for transmitting the corresponding communication data.

<Operation example for transmission>
In a vehicle, it is very important to ensure the safety of driving, so high priority is usually assigned to data output by a steering sensor related to steering of the vehicle, for example. Therefore, when the radio communication terminal 10 tries to transmit such data, the condition (Px> Pr) of S21 of FIG. 5 is satisfied, and S22 is executed. That is, the wide area communication module 21 is used to wirelessly transmit communication data.

  In this case, the communication data generation function 28 generates communication data based on the data input from the input interface 27. This communication data is input to the priority determination function 30 through the transmission destination determination function 29. Then, since the priority discrimination function 30 selects the wide area wireless communication in S22, the communication data is transmitted from the priority discrimination function 30 through the wide area wireless transmission function 21b as a radio wave from the antenna 32.

  Here, since the communication range of the wide area communication module 21 is the entire area ARL, data from the transmission source to the destination is only by one wireless communication without relaying regardless of the distance between the transmission source and the destination node. It is possible to deliver Therefore, it is possible to minimize the transmission delay time of data generated with wireless communication.

  On the other hand, since the operation of a device such as a power window is not directly related to the safety of driving, data of such a device is usually assigned a low priority. Therefore, when the radio communication terminal 10 intends to transmit such data, the condition (Px> Pr) of S21 of FIG. 5 is not satisfied, and S23 and S24 are executed. That is, the route detection / construction function 31 selects an appropriate route, and wirelessly transmits communication data using the short range communication module 22.

  In this case, the communication data generation function 28 generates communication data based on the data input from the input interface 27. This communication data is input to the priority determination function 30 through the transmission destination determination function 29. Then, since the priority discrimination function 30 selects the short range wireless communication in S24, the communication data is transmitted from the priority discrimination function 30 through the route detection / construction function 31 and the short range radio transmission function 22b as a radio wave from the antenna 33 Be done.

  Here, since the communication range of the narrow area communication module 22 is relatively small as in any of the small cell areas ARS1 to ARS3, the source and destination nodes may be located at other adjacent locations unless another node is present. It is necessary to relay communication. In addition, when the distance between the source and destination nodes is large, communication is relayed using a route that spans a plurality of small cell areas ARS1 to ARS3, and the number of relays increases and delay time increases. Increase. In addition, when the amount of traffic sent over the network increases, the communication latency time in each node also increases, and the transmission delay time of data generated along with wireless communication may further increase.

  However, since the communication range of the short range communication module 22 is narrow, the number of nodes receiving interference at the time of data transmission is smaller than that when the wide area communication module 21 transmits. Therefore, communication data to be transmitted using the wide area communication module 21 is selected as communication data to be transmitted with priority as much as possible over transmission of other data such as communication data related to the safety of driving.

<Overview of reception processing>
An outline of reception processing in the radio communication terminal 10 at each node position is shown in FIG. That is, when the radio communication terminal 10 of the own node receives a radio wave transmitted from the radio communication terminal 10 of another node and the communication succeeds, each function in the radio communication terminal 10 performs the reception process (Recv) of FIG. Run.

  The reception destination discrimination function 24 compares the destination (transmission destination address Ar2 in FIG. 7) of the reception data received by the wide-area radio reception function 21a or the short-range radio reception function 22a with the address of the own node. It is determined in S31 whether it is addressed to a node or to another node.

  When the radio communication terminal 10 receives data addressed to its own node, the received data output function 25 performs data processing on the received data. That is, the reception data output function 25 extracts the data D from the frame as shown in FIG. 7 and passes it to application software or the like of the in-vehicle device connected to the output interface 26.

  When the radio communication terminal 10 receives data addressed to another node, the priority discrimination function 30 specifies the priority Px of this data by the same processing as that in FIG. 4. Furthermore, the priority determination function 30 compares the priority Px of the received data with the priority reference value Pr in S33. Here, the priority Px of the received data is a value determined by the same processing as S13 of FIG. 4 based on the data type k1 included in the received frame (see FIG. 7).

  When the priority Px of the received data is larger than the priority reference value Pr, the priority determination function 30 uses the wide area communication module 21 as a wireless communication means used for transmission to relay the received data to another node. Select with.

  If the priority Px of the received data is less than or equal to the priority reference value Pr, the priority discrimination function 30 detects the route in S35 in order to specify the communication path in the case of transmitting the received data by narrow area wireless communication. An instruction is given to the construction function 31. The route detection / construction function 31 obtains a communication path suitable for relaying and delivering the corresponding received data to the designated destination according to the instruction of the priority determination function 30. In addition, the priority determination function 30 selects the short range communication module 22 as the wireless communication means used for transmitting the corresponding received data in S36.

<Operation example for reception>
Even when the radio communication terminal 10 of the transmission source node that has generated the data transmission request uses the wide area communication module 21 and transmits the radio wave of communication data to the range of the entire area ARL, this radio wave is the radio of the destination node There are cases where the communication terminal 10 can be reached directly and cases where relaying is required. When radio waves transmitted by the transmission source node directly reach the destination node, S31 and S32 of FIG. 6 are executed in the wireless communication terminal 10 of this destination node, so the wireless communication terminal 10 sends the destination in-vehicle device Receive data can be passed.

  When the radio wave transmitted by the radio communication terminal 10 of the transmission source node does not directly reach the radio communication terminal 10 of the destination node, the radio communication terminal 10 of the other node receives this radio wave instead of the destination node and Relay data The wireless communication terminal 10 to relay relays either the wide area communication module 21 or the narrow area communication module 22 according to the result of comparing the priority Px and the priority reference value Pr in S33 of FIG. 6 for the received data. Select for relay transmission. That is, when the transmission source node transmits using the wide area communication module 21, data is transmitted in S34 using the wide area communication module 21 even when another node relays. When the transmission source node transmits using the short range communication module 22, data is transmitted in S36 using the short range communication module 22 even when another node relays. Note that, as described later, when each node knows the distance to the destination, wide area wireless communication and narrow area wireless communication may be selected according to the distance. In this case, for example, the short-range wireless communication is performed under the condition that the distance to the destination is short and it is certain that no further relay is necessary.

<Modification on data priority determination: Modification example-1>
A modified example of the data priority determination process shown in FIG. 4 is shown in FIG. That is, when data to be transmitted is input from the reception destination determination function 24 or the transmission destination determination function 29 to the priority determination function 30, the priority determination function 30 executes the data priority determination process shown in FIG. . The operation of FIG. 8 will be described below.

  In a vehicle, it is very important to ensure the safety of driving, so high priority is usually assigned to data output by a steering sensor related to steering of the vehicle, for example. Also, for example, data outputted by a switch of the power window is usually assigned a low priority because it is not directly related to the driving of the vehicle. Therefore, the priority Px of the communication data of the steering sensor is normally higher than the communication data of the switch of the power window.

  On the other hand, in an emergency where the host vehicle encounters a traffic accident and an occupant needs to escape from the vehicle, it is more important to make the escape easier than the safety of driving. Therefore, depending on the situation, it may be preferable to set the priority Px of the communication data of the switch of the power window higher than the priority of the communication data of the steering sensor.

  Therefore, in the data priority determination process shown in FIG. 8, the priority table TB2 for normal travel and the priority table TB3 for emergency are separately prepared in advance so that they can be used properly according to the situation. .

  That is, in the priority table TB2 for normal driving, for example, data is registered in advance such that the priority Px of the communication data of the steering sensor is higher than that of the switch of the power window. In the emergency priority table TB3, for example, data is registered in advance such that the priority Px of the communication data of the switch of the power window is higher than the priority of the communication data of the steering sensor.

  The priority determination function 30 of the wireless communication terminal 10 acquires information indicating the current state of the vehicle in S41, and selects one of the priority tables TB2 and TB3 in S42 according to the state. For example, if the air bag of the vehicle is activated, or if a large acceleration is detected and the vehicle is stopped, the priority determination function 30 selects the priority table TB3 as an emergency. Do. If it is not an emergency, the priority table TB2 is selected.

  In S45 of FIG. 8, the priority determination function 30 determines the priority Px based on the data type k1 and the destination k2 using the priority table TB2 or TB3 selected in S42.

<Modification relating to transmission processing: Modification example 2>
A modification of the transmission process shown in FIG. 5 is shown in FIG. That is, when each wireless communication terminal 10 transmits data input to the interface 27 as a wireless signal to terminals of other nodes according to a transmission request input from the interface 27, the priority of the corresponding transmission target data is determined. For this purpose, the priority determination function 30 executes the transmission process (Send) shown in FIG.

  In the transmission process of FIG. 9, it is determined in S51 whether or not a plurality of transmission requests have occurred simultaneously. Then, when a plurality of transmission requests are simultaneously generated, the processing order of the plurality of transmission requests is determined in accordance with the type k1 of each data in the next S52. That is, the order of processing is determined such that data to be prioritized (for example, data having a short allowable delay time) among the plurality of data is processed first.

  In addition, before identifying the priority Px, it is determined in S53 whether the distance of the destination k2 is close to, for example, a predetermined threshold value. Then, if the distance is short, the process proceeds from S53 to S56 and S57, and the short range wireless communication is selected.

  If the distance to the destination k2 is not short, reference is made to the priority Px in the next S54, and either wide area wireless communication or narrow area wireless communication is performed according to the priority Px as in the case of the transmission processing of FIG. The selection is made (S55, S57).

  For example, when S53 in FIG. 9 is omitted, and the priority Px is determined in S13 in FIG. 4 instead, processing may be performed to lower the priority Px when the distance of the destination k2 is short. . Also in this case, the short-range wireless communication is selected when the distance of the destination k2 is short as in the process of FIG. Further, the same process as each of steps S51 to S53 shown in FIG. 9 may be added between S31 and S33 of the reception process shown in FIG. Thereby, when relaying data, the same operation as that of FIG. 9 can be performed.

<Possibility of deformation of wireless communication system for vehicles>
The wireless communication terminal 10 shown in FIG. 3 switches between the wide area communication module 21 and the narrow area communication module 22 according to the type and priority of transmission target data, and switches the communication format. Furthermore, control may be performed to switch the directivity of the antennas 32 and 33 in accordance with the direction of the communication partner.

  Further, with regard to the selection of the communication path between the transmission source and the destination in the case of performing the short range wireless communication using the short range communication module 22, it is conceivable to use various existing technologies. Also, for example, the communication path may be selected using the technology disclosed in Patent Document 3.

  In the configuration of the wireless communication terminal 10 shown in FIG. 3, the processing of the priority determination function 30 is performed after the processing of the transmission destination determination function 29 is performed on the communication data generated by the communication data generation function 28. Although the process is performed, the process of the transmission destination determination function 29 may be performed after the process of the priority determination function 30 is performed in reverse order.

  As a specific example of the communication format of the wide area communication module 21, it is assumed that a communication format having a narrow band characteristic is adopted, and as a specific example of the communication format of the narrow area communication module 22, a communication format having a wide band characteristic It is assumed to adopt However, such a communication form is appropriately changed as needed.

<Modification-3>
A modification of the transmission process shown in FIG. 5 is shown in FIG. That is, when each wireless communication terminal 10 transmits data input to the interface 27 as a wireless signal to terminals of other nodes in accordance with a transmission request input from the interface 27, the transmission process (Send) shown in FIG. To be executed.

  In the transmission process of FIG. 10, the priority determination function 30 acquires information indicating the current state of the host vehicle in S61. The information acquired in S61 also includes information indicating occurrence of an accident of the host vehicle, that is, collision detection. For example, when a large acceleration that causes the air bag to operate is detected, this is regarded as collision detection of the host vehicle and processed.

  When any one of the on-vehicle devices mounted on the host vehicle detects a collision of the host vehicle, all the wireless communication terminals 10 can share the information. For example, the wireless communication terminal 10 connected to the on-vehicle apparatus that has detected the collision broadcasts this information to all the other wireless communication terminals 10.

The communication data creation function 28 adds information necessary for communication to the input data input from the input interface 27 to create communication data to be sent (S62).
The transmission destination determination function 29 determines the transmission destination from the communication data created by the communication data creation function 28 (S63).

  The priority determination function 30 determines the priority Px by executing the process shown in FIG. 4 or 8, for example, on the communication data input from the transmission destination determination function 29 (S64). In addition, in the case where the collision detection state is grasped in S61, communication data is used for operation information such as a button relating to the danger of a life, such as opening and closing of a window or a door necessary for an occupant to get out of the vehicle. The priority Px of P.sub.x is made to be the highest and is made to exceed the priority reference value Pr.

  Based on the information acquired in S61, the priority determination function 30 identifies in S65 whether the state of high urgency is high. For example, in an emergency where the collision detection state is grasped in S61, the process proceeds from S65 to S67. If the degree of urgency is low, the process proceeds from step S65 to step S66.

  The priority determination function 30 compares the priority Px of the communication data determined in S64 with the priority reference value Pr (S66), and if "Px> Pr", the process proceeds to S67, and if "Px ≦ Pr" Go to S68.

  At S68, the route detection / construction function 31 detects a communication route (communication route) to the destination by the short range wireless communication. If it is possible to communicate with the destination by the short range wireless communication, the process proceeds from S68 to S69.

  On the other hand, if the communication path to the destination can not be secured due to the occurrence of a failure of the wireless device, etc., the "communication availability judgment" function of the route detection / construction function 31 is regarded as a state of high urgency and S68 to S67. Go to

  For example, when an acknowledgment (ACK) for the transmitted communication data does not return within a predetermined time on the communication route to the destination, it is considered that the generation of the communication route has failed. Alternatively, the wireless communication terminals 10 performing short-range wireless communication may be defined to transmit and receive beacon signals at fixed time cycles, and if the beacon signals can not be received for a fixed period, the corresponding communication The route is considered to be incommunicable.

  Therefore, in the case of an emergency such as a collision detection state of the own vehicle, when the priority Px of communication data exceeds the priority reference value Pr, and due to a failure or the like, a communication path can not be secured by narrow area wireless communication. In this case, the wide area wireless communication is executed by the wide area communication module 21 in S67.

  If the priority Px of communication data is equal to or lower than the priority reference value Pr and the communication path can be secured by the short range wireless communication at times other than emergency, the short range communication module 22 performs the narrow range wireless communication in S69. Communication is performed.

A modification of the reception process shown in FIG. 6 is shown in FIG. That is, when the radio communication terminal 10 of the own node receives a radio wave transmitted from the radio communication terminal 10 of another node, each function in the radio communication terminal 10 executes the reception process (Recv) of FIG.
The communication success discrimination function 23 identifies in S71 whether the short range wireless reception function 22a or the wide area wireless reception function 21a has successfully received the communication data transmitted by radio waves from the wireless communication terminals 10 of other nodes. In the case of success, the process proceeds to S72.

  The reception destination determination function 24 determines in S72 whether the destination of the communication data received by the short range radio reception function 22a or the wide area radio reception function 21a is the own node. If the communication data addressed to the own node is received, the process proceeds to S73, the received data output function 25 performs data processing, and the result is passed to the application software via the output interface 26.

  If communication data addressed to another node is received, the process proceeds to step S74 to relay the data. In that case, the priority determination function 30 acquires information representing the current state of the host vehicle, as in S61 of FIG. 10 (S74). Further, the priority determination function 30 determines the priority Px of the communication data to be relayed (S75).

  Based on the information acquired in S74, the priority determination function 30 identifies in S76 whether the state of high urgency is high. For example, in an emergency where the collision detection state is grasped in S74, the process proceeds from S76 to S78. If the degree of urgency is low, the process proceeds from step S76 to step S77.

  The priority determination function 30 compares the priority Px of the communication data determined in S75 with the priority reference value Pr (S77), and if “Px> Pr”, the process proceeds to S78, and if “Px ≦ Pr” Go to S79.

  At S79, the route detection / construction function 31 detects a communication route (communication route) to the destination by the short range wireless communication. If it is possible to communicate by the short range radio communication to the destination, the process proceeds from S79 to S80. If the communication path to the destination can not be secured due to the occurrence of a failure of the wireless device, etc., it is considered that the "communication availability judgment" function of the route detection / construction function 31 is in a state of high urgency and S79 to S78. Go to

  Therefore, even when each wireless communication terminal 10 relays communication data, when in an emergency such as a collision detection state of the own vehicle, the priority Px of the communication data exceeds the priority reference value Pr, and the failure occurs. When the communication path can not be secured by the short range wireless communication due to the reason, the wide range wireless communication is executed by the wide range communication module 21 in S78.

  If the priority Px of communication data is equal to or lower than the priority reference value Pr and the communication path can be secured by the short range wireless communication except during an emergency, the short range communication module 22 performs the short range wireless communication in S80. Communication is performed.

  In the process of FIG. 10, whether or not it is an emergency is identified in S65, but if the degree of urgency is reflected in the priority Px in S64, S65 may be omitted. In that case, wide area wireless communication can be preferentially selected in an emergency by the determination of the next S66. The same applies to the reception process of FIG.

<Advantages of Wireless Communication System for Vehicles>
As described above, according to the wireless communication system for a vehicle according to the embodiment of the present invention, when each wireless communication terminal 10 performs wireless transmission of communication data, the wide range according to the type k1 of data and its priority Px One of the communication module 21 and the short range communication module 22 is selected. Therefore, there is no need to simultaneously secure the resources of both the wide area communication module 21 and the short range communication module 22 in order to communicate with the same communication partner, and the remaining unused resources are exchanged with other communication partners. Can be used to communicate with That is, communication can be performed efficiently by effectively using limited resources for wireless communication. Also, the amount of traffic sent to the network can be reduced.

  In addition, when each wireless communication terminal 10 transmits communication data with high priority, the wide area communication module 21 is always selected to perform wireless communication in the range of the entire area ARL. It is possible to shorten the communication quality and to surely improve the communication quality.

  Further, since each wireless communication terminal 10 switches between wide area communication and narrow area communication according to the type k1 of data and its priority Px when performing wireless transmission of communication data, the application software of the transmission source in-vehicle device There is no need to monitor the operation and control is easier.

  In addition, when the wireless communication terminal 10 executes the data priority determination process shown in FIG. 4, it is possible to assign an appropriate priority Px to each combination of the type k1 of transmission target data and the destination k2 thereof. it can.

  Further, when the wireless communication terminal 10 executes the data priority determination process shown in FIG. 8, it is possible to appropriately switch the high and low of the priority of each communication data, for example, in an emergency, according to the condition of the vehicle. .

  Further, each radio communication terminal 10 executes the processing of FIGS. 10 and 11 to narrow the case where an accident of the own vehicle such as a collision occurs or a failure of some of the radio communication terminals 10 included in the in-vehicle system Wide area wireless communication can be automatically selected in an emergency where it is not possible to secure a communication path by area wireless communication. Thus, when performing communication with a high degree of urgency, the communication delay time can be shortened. Further, when performing communication with a low degree of urgency or priority, interference and effects of radio waves respectively transmitted from a large number of wireless communication terminals 10 can be suppressed by selecting narrow area wireless communication.

Here, the features of the above-described vehicle radio communication system according to the embodiment of the present invention will be briefly summarized and listed in the following [1] to [7].
[1] A wide-area wireless communication function (wide-area communication module 21) mounted on a vehicle and capable of wireless communication on the vehicle, and a narrow-area wireless communication function having a narrower wireless communication area than the wide-area wireless communication function A plurality of wireless communication terminals (10) having (a short range communication module 22), and when each wireless communication terminal transmits data, the priority (Px) is set according to the type (k1) of transmission target data. Identify
When the priority of the transmission target data is high, at least the wide area wireless communication function is selected, and when the priority of the transmission target data is low, at least the narrow area wireless communication function is selected to perform wireless communication (FIG. 5). reference),
A wireless communication system for a vehicle, characterized in that

[2] Each of the wireless communication terminals switches the priority (Px) according to the type (k1) of the transmission target data according to the change of the situation (see FIG. 8).
The wireless communication system for a vehicle according to [1], characterized in that

[3] Each of the wide area wireless communication function and the short range wireless communication function includes a transmission / reception function,
Each wireless communication terminal has a destination identification function (reception destination determination function 24) for identifying whether the received data is addressed to its own node, and a wireless relay function for wirelessly transmitting received data other than that addressed to the own node to the destination. (Priority determination function 30: S33 to S36)
When the wireless relay function transmits data, a priority (Px) is specified according to the type of transmission target data, and when the priority of the transmission target data is high, at least the wide area wireless communication function is selected; When the priority of the transmission target data is low, at least the short-range wireless communication function is selected to perform wireless communication.
A vehicle radio communication system according to the above [1] or [2], characterized in that

[4] The wide area wireless communication function uses a first wireless communication format suitable for wide area communication,
The short range wireless communication function uses a second wireless communication format suitable for short range communication.
A vehicle radio communication system according to any one of the above [1] to [3], characterized in that

[5] A wide-area wireless communication function (wide-area communication module 21) mounted on a vehicle and capable of wireless communication on the vehicle, and a narrow-area wireless communication function in which the area capable of wireless communication is narrower than the wide-area wireless communication function A plurality of wireless communication terminals (10) having (a short range communication module 22);
When each wireless communication terminal transmits data, it grasps the level of urgency in the own vehicle, and specifies at least the priority (Px) reflecting the difference in the type of transmission target data (S64, S75).
According to the degree of urgency and the priority, one of the wide area wireless communication function and the narrow area wireless communication function is preferentially selected to perform wireless communication (S65 to S69, S76 to S80).
A wireless communication system for a vehicle, characterized in that

[6] In an emergency including occurrence of an accident of the own vehicle, when each wireless communication terminal transmits data, wireless communication is performed by preferentially selecting the wide area wireless communication function based on the degree of urgency (S65, S67),
The vehicle radio communication system according to the above [5].

[7] When each wireless communication terminal transmits data, if the communication path to the destination can not be secured by the communication of the narrow area wireless communication function, the wide area wireless communication function is selected based on the degree of urgency Perform a wireless communication by preferentially selecting (S68, S67),
The vehicle radio communication system according to the above [5].

DESCRIPTION OF SYMBOLS 10 wireless communication terminal 21 wide area communication module 21a wide area wireless reception function 21b wide area wireless transmission function 22 narrow area communication module 22a narrow area wireless reception function 22b narrow area wireless transmission function 23 communication success determination function 24 reception destination determination function 25 received data output function 26 output interface 27 input interface 28 communication data creation function 29 transmission destination determination function 30 priority determination function 31 route detection / construction function 32, 33 antennas TB1, TB2, TB3 priority table Px priority Pr priority reference value AR-A , AR-B, AR-C, AR-D Small cell area ARL whole area ARS1, ARS2, ARS3 Small cell area C01, C03, C04, C05, C07 Wireless communication path C08, C09, C11, C12, C13, C14 Wireless communication Path C15, C16 Wireless communication path NA-1, NA-2, NA-3, NB-1, NB-2, NB-3, NB-4 Node NC-1, NC-2, NC-3, NC-4 , ND-1, ND-2, ND-3 nodes

Claims (7)

It has a wide-area wireless communication function mounted on a vehicle and capable of wireless communication on the vehicle, and a plurality of wireless communication terminals having a narrow-area wireless communication function in which the area capable of wireless communication is narrower than the wide-area wireless communication function. ,
When each wireless communication terminal transmits data, the priority is specified according to the type of transmission target data,
When the priority of the transmission target data is high, at least the wide area wireless communication function is selected, and when the priority of the transmission target data is low, at least the narrow area wireless communication function is selected to perform wireless communication.
A wireless communication system for a vehicle, characterized in that Each of the wireless communication terminals switches the priority according to the type of transmission target data according to the change of the situation.
A wireless communication system for a vehicle according to claim 1, characterized in that. Each of the wide area wireless communication function and the short range wireless communication function includes a transmission / reception function,
Each of the wireless communication terminals has a destination identification function for identifying whether the received data is addressed to the own node, and a wireless relay function for wirelessly transmitting received data other than for the own node to the destination, When the relay function transmits data, the priority is specified according to the type of transmission target data, and when the transmission target data has high priority, at least the wide area wireless communication function is selected, and the transmission target data is selected. When the priority is low, at least the short-range wireless communication function is selected to perform wireless communication,
The wireless communication system for vehicles according to claim 1 or 2 characterized by things. The wide area wireless communication function uses a first wireless communication format suitable for wide area communication,
The short range wireless communication function uses a second wireless communication format suitable for short range communication.
The wireless communication system for a vehicle according to any one of claims 1 to 3, characterized in that: It has a wide-area wireless communication function mounted on a vehicle and capable of wireless communication on the vehicle, and a plurality of wireless communication terminals having a narrow-area wireless communication function in which the area capable of wireless communication is narrower than the wide-area wireless communication function. ,
When each wireless communication terminal transmits data, while grasping the degree of urgency in the own vehicle, at least the priority reflecting the difference in the type of transmission target data is specified,
According to the degree of urgency and the priority, one of the wide area wireless communication function and the narrow area wireless communication function is preferentially selected to perform wireless communication.
A wireless communication system for a vehicle, characterized in that In an emergency including an accident occurrence of the own vehicle, when each wireless communication terminal transmits data, the wide area wireless communication function is preferentially selected based on the degree of urgency to perform wireless communication.
The wireless communication system for a vehicle according to claim 5. When each wireless communication terminal transmits data, if the communication path to the destination can not be secured by the communication of the narrow area wireless communication function, the wide area wireless communication function is given priority based on the degree of urgency. Select to communicate wirelessly,
The wireless communication system for a vehicle according to claim 5.

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