JP7609612B2 - Wireless communication device and wireless communication system - Google Patents

Description

The present invention relates to a wireless communication device and a wireless communication system.

It has been known for some time that many networks, such as wireless LANs and cellular networks, communicate in infrastructure mode by connecting to a specific base station. These base stations form a so-called infrastructure network that allows for stable communications. Terminals connect to the infrastructure network to communicate.

For example, in Non-Patent Document 1, even if a communication partner exists within the same network accommodated by one base station, the transmitting terminal transmits communication data to the destination terminal via the base station. Also, if the destination terminal of the communication exists in an area configured by another base station, the communication data is transferred between base stations, and the communication data is transmitted to the destination terminal from the base station that configures the area to which the destination terminal belongs. In reality, there are multiple base stations, so networks can be formed in various forms.

Yamamoto et al., "Study on LTE base station load balancing method in various traffic environments," RCS Study Group, vol. 112, no. 351, pp. 41-46, December 2012.

When communicating in the above-mentioned ad-hoc network, it may be possible to perform wireless communication by shortening the wireless communication path due to overhear or the like. However, if a terminal where wireless communication is omitted due to overhear or the like does not transmit a reception notification, the terminal on the next fixed route in the routing order that should have originally transmitted the notification may start wireless communication even though the communication has ended, which may result in an increase in traffic.

The present invention has been made in consideration of the problems anticipated in the related art of the above-mentioned prior art. The object of the present invention is to provide a wireless communication system etc. that can suppress unnecessary traffic by appropriately transmitting a reception notification to make the appropriate terminal on the communication path recognize that the wireless communication has ended, even when the communication path is omitted due to overhear.

In accordance with an aspect of the present invention, a wireless communication device capable of forming an ad-hoc network includes: a reception notification generating unit that generates a reception notification of overheard communication data when the wireless communication device overhears communication data for which the destination wireless communication device is the wireless communication device, and a wireless transmission unit that transmits the reception notification to a wireless communication device that forms the fixed route and is a party to which the wireless communication device that transmitted the overheard communication data directly transmitted the communication data, when the wireless communication device is capable of directly communicating with one of the wireless communication devices that form a fixed route and is not a wireless communication device that forms the fixed route.

According to the present invention, even if a communication path is omitted due to overhear, by appropriately transmitting a reception notification, it is possible to provide a wireless communication system etc. that can suppress unnecessary traffic by making the appropriate terminal on the communication path recognize that the wireless communication has ended.

1 is a schematic diagram showing an example of a wireless communication system constituting a network according to an embodiment of the present invention; 2 is a schematic diagram showing an example of a communication path through which communication data is transferred in the wireless communication system of FIG. 1 according to the present embodiment. 2 is a schematic diagram showing an example in which a wireless communication device that has overheard communication data transmits a reception notification to other appropriate wireless communication devices in the wireless communication system of FIG. 1 according to this embodiment. FIG. (a) A schematic diagram showing an example of connection information stored in a wireless communication device according to the present embodiment, (b) A schematic diagram showing an example of connection information stored in a wireless communication device according to the present embodiment, (c) A schematic diagram showing an example of connection information stored in a wireless communication device according to the present embodiment, and (d) A schematic diagram showing an example of connection information stored in a wireless communication device according to the present embodiment. 1 is a block diagram showing an example of a configuration of a wireless communication device according to an embodiment of the present invention. 6 is a flowchart showing an example of a condition when a state of the wireless communication device according to the embodiment changes. 5 is a flowchart showing an example of a transmission operation when the wireless communication device according to the embodiment transmits communication data. 5 is a flowchart showing an example of a relay/reception operation when the wireless communication device according to the present embodiment relays or receives communication data. FIG. 2 is a schematic diagram showing an example of a configuration of a communication network according to a first comparative example; 10 is a schematic diagram showing the transmission and reception operations of terminals in the communication network according to the comparative example of FIG. 9 . FIG. 11 is a schematic diagram showing an example of the configuration of a communication network according to a second comparative example.

(Overview of the configuration of a wireless communication system)
The wireless communication device of the wireless communication system of the present embodiment has a configuration capable of reducing the number of hops by overhear. However, in the conventional technology, when overhear occurs, a terminal in which wireless communication on a communication path is omitted does not receive a reception notification, and there is a possibility that the terminal performs unnecessary wireless communication, which increases traffic.

The wireless communication system of this embodiment is configured to suppress an increase in traffic when the destination wireless communication device recognizes that it has received communication data through overhear by sending a reception notification to an appropriate terminal.

(Example of a configuration of a wireless communication system)
As an example, an outline of the operation in the topology of an ad-hoc network formed by the wireless communication device of this embodiment will be described with reference to Fig. 1. Note that in this specification, the wireless communication device may be referred to as a terminal.

In FIG. 1, the wireless communication system preselects terminals that are frequently used for relay communication, connects the selected terminals with a high communication success rate in a ring shape, and the wireless communication system performs wireless communication using the communication path connected in the ring shape as a fixed route.

In FIG. 1, a fixed route is formed by terminals 100a, 100b, 100c, 100d, 100e, 100f, 100g, and 100h connected in a ring shape.

A terminal other than the terminal located on the fixed route wirelessly communicates with any of the terminals forming the fixed route, but does not perform wireless communication with other terminals. For example, as shown in FIG. 1. Terminal 100a1 communicates directly with terminal 100a, and does not communicate directly with other terminals. Similarly, terminal 100a2 communicates directly with terminal 100a, and does not communicate directly with other terminals. Similarly, terminal 100b1 communicates directly with terminal 100b, and does not communicate directly with other terminals. Similarly, terminal 100c1 communicates directly with terminal 100c, and does not communicate directly with other terminals. Similarly, terminal 100d1 communicates directly with terminal 100d, and does not communicate directly with other terminals. Similarly, terminal 100d2 communicates directly with terminal 100d, and does not communicate directly with other terminals. Similarly, terminal 100e1 communicates directly with terminal 100e, and does not communicate directly with other terminals. Similarly, terminal 100f1 communicates directly with terminal 100f, and does not communicate directly with other terminals. Similarly, the terminal 100f2 communicates directly with the terminal 100f, but does not communicate directly with other terminals. Similarly, the terminal 100g1 communicates directly with the terminal 100g, but does not communicate directly with other terminals. Similarly, the terminal 100g2 communicates directly with the terminal 100g, but does not communicate directly with other terminals. Similarly, the terminal 100h1 communicates directly with the terminal 100h, but does not communicate directly with other terminals. Similarly, the terminal 100h2 communicates directly with the terminal 100h, but does not communicate directly with other terminals. Also, in this specification, the terminals 100a, 100b, 100c, 100d, 100e, 100f, 100g, 100h, 100a1, 100a2, 100b1, 100c1, 100d1, and 100d2 may be collectively referred to as the wireless communication device 100. Furthermore, 100e1, 100f1, 100f2, 100g1, 100g2, 100h1, and 100h2 may be collectively referred to as wireless communication device 100. Furthermore, a terminal that forms a fixed route directly communicates only with the next terminal that forms the fixed route, and with terminals outside the fixed route that can directly communicate. Furthermore, each terminal stores in advance information about the terminal to be connected.

(Example of operation of wireless communication system)
Further, an example of the wireless communication operation of the wireless communication system according to the present embodiment will be described with reference to Fig. 2, Fig. 3, and Fig. 4. Fig. 2 is a schematic diagram showing a communication flow of the wireless communication system according to the present embodiment. Fig. 3 is a schematic diagram showing a reception notification flow of the wireless communication system according to the present embodiment. Fig. 4 is a schematic diagram showing terminal information stored in each of the wireless communication devices 100 according to the present embodiment. The details of the terminal information will be described later.

As shown in FIG. 2, a case will be described in which a request to send communication data is generated in terminal 100a2, with terminal 100d1 as the destination terminal.

Since terminal 100a2 is not a terminal that forms a fixed route, it performs wireless transmission of communication data to terminal 100a, which forms a fixed route, according to the terminal information of terminal 100a2 (see FIG. 4(a)). If terminal 100d1, which is the destination terminal, can overhear this wireless transmission, the wireless transmission ends. However, in FIG. 2, it is assumed that terminal 100d1 cannot overhear the wireless transmission from terminal 100a2.

Terminal 100a, which has received communication data from terminal 100a2, compares the destination terminal information of the communication data with the terminal information stored in terminal 100a, and determines that a terminal that does not form a fixed route within the communication area of terminal 100a is not a destination terminal. Then, terminal 100a wirelessly transmits the communication data to terminal 100b, which forms a fixed route to the next wireless destination, in accordance with the terminal information. If terminal 100d1, which is the destination terminal, can overhear this wireless transmission, the wireless transmission ends. However, in FIG. 2, it is assumed that terminal 100d1 cannot overhear the wireless transmission from terminal 100a.

Terminal 100b, which has received communication data from terminal 100a, compares the destination terminal information of the communication data with the terminal information stored in terminal 100b, and determines that a terminal that does not form a fixed route within the communication area of terminal 100b is not a destination terminal. Therefore, terminal 100b wirelessly transmits the communication data to terminal 100c, which forms a fixed route to the next wireless destination, in accordance with the terminal information. This wireless transmission is received by terminal 100c, but terminal 100d1, which is the destination terminal, can also overhear the wireless transmission. Therefore, terminal 100d1, which is the destination terminal, transmits a reception notification of the communication data.

As shown in FIG. 3, terminal 100d1, which is the destination terminal, determines from the terminal information stored in terminal 100d1 that the previous terminal is different from terminal 100b that transmitted the communication data. Then, from the terminal information of the destination of the communication data that it overheard, terminal 100d1 recognizes that the next wireless destination terminal of terminal 100b is terminal 100c. Therefore, terminal 100d1 transmits a reception notification of the communication data to terminal 100c.

Figure 3 shows how terminal 100d1, a destination terminal that has overheard communication data from terminal 100b to terminal 100c, determines that it has overheard the data from the terminal information and the next destination information of the communication data, and sends a reception notification to terminal 100c.

If there was no overhear, the above communication data would be transferred from terminal 100a2 → terminal 100a → terminal 100b → terminal 100c → terminal 100d → terminal 100d1. However, when terminal 100d1 overhears the communication data from terminal 100b, unnecessary wireless communication occurs from terminal 100c → terminal 100d → terminal 100d1. In other words, wireless communication from terminal 100a2 → terminal 100a → terminal 100b → terminal 100d1 and terminal 100c → (terminal 100d1) → terminal 100b is actually performed, making it possible to suppress traffic.

In the example of FIG. 11, a wireless communication device 100 that constitutes an infrastructure network in a vehicle 10 is shown. The wireless communication devices 100 that constitute the infrastructure network can be set in advance based on the installation positions of the wireless communication devices 100 and a combination that can form a communication path between the wireless communication devices 100 that is less affected by obstacles such as passengers. For example, in FIG. 11, terminals 100i, 100j, and 100k arranged along the body of the vehicle operate as fixed route terminals and form an infrastructure network. Terminals 100i1, 100j2, 100j3, and 100k1 can communicate with one of terminals 100e, 100f, and 100g that form the infrastructure network. In addition, as an example, a front right tire T1, a front left tire T2, a rear left tire T3, and a rear right tire T4 are attached to the vehicle 10.

(Example of the configuration of a wireless communication device)
FIG. 5 is a block diagram showing an example of the configuration of the wireless communication device 100. As shown in FIG. 5, the wireless communication device 100 includes a transmitting/receiving unit 110, a wireless receiving unit 120, a received data determining unit 130, a receiving notification generating unit 140, a transmission destination determining unit 150, a transmission data generating unit 160, an external I/F unit 170, a storage unit 180, and a wireless transmitting unit 190. Note that the antenna unit ANT is an option that may or may not be included in the wireless communication device 100. The wireless communication device 100 may be a general computer including the above blocks. The general computer executes a control program to realize the functions shown in FIG. 5. Only the parts related to the features of this embodiment will be described below. Therefore, it goes without saying that the wireless communication device 100 includes other functional blocks that are not directly related to the features of this embodiment.

The storage unit 180 may be a read only memory (ROM), a random access memory (RAM), a hard disk, etc. The storage unit 180 may also store various data such as input data, output data, and intermediate data for the wireless communication device 100 to execute processing. Some functions of the wireless communication device 100 may be executed by a central processing unit (CPU).

The transceiver unit 110 has a function of connecting the wireless transmitter unit 190 and the antenna unit ANT when the wireless communication device 100 is in a transmission mode, and connecting the wireless receiver unit 120 and the antenna unit ANT when the wireless communication device 100 is in a reception mode. In addition, when the antenna unit ANT has directionality, the transceiver unit 110 also has a function of controlling the directivity of the antenna unit ANT.

The wireless receiving unit 120 can amplify and demodulate communication data received via the antenna unit ANT. Any method can be used for demodulation in the wireless communication system 1000. It is also possible to use the MCS (Modulation Coding Scheme) defined in IEEE802.11. An example of radio waves received from the antenna unit ANT is radio waves in the millimeter wave band, but the radio waves are not limited to millimeter wave band radio waves, and radio waves in any frequency band can be used. The communication data received via the antenna unit ANT may also include a reception notification generated by another terminal.

The received data determination unit 130 has a function of determining whether the destination terminal of the received data that has been subjected to processing such as demodulation by the wireless receiving unit 120 is the own terminal. Information about the destination terminal may be present in the header section of the received data, but is not limited to this, and information about the destination terminal may also be written in an area other than the header section of the received data.

The reception notification generating unit 140 has a function of generating a reception notification when the destination terminal of the received data is the own terminal. The reception notification is not limited to an ACK, and the wireless communication system 1000 can set any form as the reception notification.

The destination determination unit 150 has a function of determining the destination terminal of the transmission data or reception notification, or the destination terminal of the received data. The destination determination unit 150 regards the destination terminal of the transmission data as the destination terminal related to the transmission request information, and transmits the transmission data to the next destination terminal by referring to the connection information storage unit 182 described later. That is, if the terminal itself is a terminal outside the fixed route, the communication data is transferred to a terminal in the fixed route to which the terminal itself belongs. Also, if the terminal itself is a terminal in a fixed route, and the destination terminal is a terminal in the area to which the terminal itself belongs, the communication data is transmitted to the terminal in the area. Also, if the terminal itself is a terminal in a fixed route and the destination terminal is a terminal outside the area to which the terminal itself belongs, the communication data is transferred to the terminal in the next fixed route.

Furthermore, if the destination terminal of the received communication data is the own terminal, the destination determination unit 150 returns a reception notification to the transmitting terminal that transmitted the communication data.

Furthermore, if the destination terminal of the communication data overheard by the own terminal is not the own terminal, the transmission destination determination unit 150 discards the communication data. Furthermore, if the destination terminal of the communication data overheard by the own terminal is the own terminal, the transmission destination determination unit 150 executes the following process.
The destination determination unit 150 refers to the connection information storage unit 182 and acquires information on the terminal to which the transmission terminal of the overheard communication data should have next transmitted the communication data. The destination determination unit 150 transmits a reception notification to the terminal to which the transmission terminal of the overheard communication data should have next transmitted the communication data, and prevents the terminal from transmitting the communication data. In other words, when a terminal receives a reception notification related to the communication data after receiving the communication data, the terminal determines that the communication data has been received by the destination terminal by overhearing, and operates to discard the communication data.

The transmission data generation unit 160 has a function of generating transmission data as the communication data to be transmitted when it receives a transmission request, which is information indicating that communication data to be transmitted has been generated, from the external I/F unit 170.

The external I/F unit 170 is an input/output interface for communication data to be transmitted and received, and may be an interface with a device such as a sensor connected to the wireless communication device 100, or with an electronic device. An ECU (Electronic Control Unit) may be configured by the device or electronic device connected to the external I/F unit 170. The electronic device may include electronic devices such as vehicle control devices, vehicle sensing devices, vehicle surrounding information acquisition devices, and entertainment devices as in-vehicle devices. The vehicle control devices may include navigation devices and autonomous driving control devices.

The memory unit 180 includes a communication data buffer unit 181 and a connection information memory unit 182.

The communication data buffer unit 181 has the function of temporarily storing communication data when a transmission request occurs in the terminal itself, communication data when relaying and transmitting, and transmission data such as reception notifications generated by the reception notification generation unit 140.

The connection information storage unit 182 has a function of storing information about the next terminal to which the terminal should transmit information received by the terminal itself, and in some cases, information about the terminal to which the terminal should transmit information that the terminal itself should receive. When there is no fixed route end and the terminal itself is a terminal that forms a fixed route, the connection information storage unit 182 stores information about the terminal to which the terminal should transmit information that the terminal itself should receive, and information about the next terminal to which the terminal itself should transmit information that the terminal itself has received.

The type of terminal information stored in the connection information storage unit 182 differs depending on whether the terminal itself is a terminal that forms a fixed route or a terminal that does not form a fixed route. In other words, in the case of a terminal that does not form a fixed route, the terminal that should transmit the information that the terminal itself should receive and the terminal that should next transmit the information that the terminal itself has received are only terminals that form a fixed route. However, the connection information storage unit 182 of a terminal that forms a fixed route stores information on the terminal that should transmit the information that the terminal itself should receive and the terminal that should next transmit the information that the terminal itself has received, as well as information on terminals that do not form a fixed route with the terminal itself and have good communication quality. For example, as shown in FIG. 4(c), the terminal 100b of the fixed route stores information on the terminal of the fixed route that should transmit the information that the terminal itself should receive, information on the terminal 100a, and stores information on the terminal of the fixed route that should next transmit the information that the terminal itself has received, information on the terminal 100c. Furthermore, terminal 100b on the fixed route stores information about terminal 100b1, which does not form a fixed route with good communication quality with its own terminal, as information about a terminal outside the fixed route to which the terminal should transmit information that the terminal should receive, and information about a terminal outside the fixed route to which the terminal should next transmit information that the terminal has received.

Similarly, as shown in FIG. 4(b), terminal 100a on a fixed route stores information on a terminal on a fixed route to which the terminal should receive information, information on terminal 100h, and stores information on a terminal on a fixed route to which the terminal should next transmit information received by the terminal, information on terminal 100b. Furthermore, the connection information storage unit 182 of terminal 100a on a fixed route stores information on the terminal itself and terminals outside the fixed route that have good communication quality. As shown in FIG. 4(b), terminals 100a1 and 100a2 are stored as information on terminals outside the fixed route to which the terminal should receive information, and information on terminals outside the fixed route to which the terminal should next transmit information received by the terminal.

The identification information of the terminal stored in the connection information storage unit 182 may be information that is predetermined in the wireless communication system 1000. However, when the communication environment changes dynamically, the terminals may exchange communication quality with each other at predetermined time intervals, before transmitting information, etc., and the identification information of the terminal whose communication quality exceeds a predetermined value may be updated in the connection information storage unit 182. The predetermined value regarding the communication quality may be predetermined in the wireless communication system 1000. In addition, the information of the terminal that should transmit information that the terminal itself should receive, and the information of the terminal that should next transmit the information that the terminal itself has received, which are stored in the connection information storage unit 182, are each the identification information of one terminal. There is no limit to the type of communication quality, and the identification information of each one terminal may be the identification information of the terminal with the best type of communication quality stored in the connection information storage unit 182. In addition, the shape of the fixed route may be determined in advance or dynamically in the wireless communication system 1000.

When the connection information storage unit 182 is included in a terminal that does not form a fixed route, the information of the terminal to which the terminal itself should next transmit the information received and the information of the terminal to which the terminal itself should transmit the information to be received are the identification information of the same terminal that forms the fixed route. For example, the connection information storage unit 182 of the terminal 100a2 that does not form a fixed route shown in FIG. 4(a) stores the identification information of the terminal 100a that forms the fixed route as the information of the terminal to which the received information should next be transmitted and the information of the terminal to which the information to be received should be transmitted. Similarly, the connection information storage unit 182 of the terminal 100d1 that does not form a fixed route shown in FIG. 4(d) stores the identification information of the terminal 100d that forms the fixed route as the information of the terminal to which the received information should next be transmitted and the information of the terminal to which the information to be received should be transmitted. Moreover, the connection information storage unit 182 of the terminal that does not form a fixed route does not store information of other terminals that do not form a fixed route.

The wireless transmission unit 190 is capable of amplifying and modulating the communication data transmitted via the antenna unit ANT. Any modulation method can be adopted in the wireless communication system 1000. It is also possible to use the MCS (Modulation Coding Scheme) defined in IEEE802.11. An example of the radio waves transmitted from the antenna unit ANT is a millimeter wave band radio wave, but the radio waves are not limited to millimeter wave band radio waves, and any frequency band radio waves can be used. The communication data transmitted via the antenna unit ANT may also include a reception notification.

The wireless communication system 1000 according to the present embodiment described above can be mounted on a moving object such as a vehicle. When the wireless communication system 1000 is constructed inside an automobile, the terminals constituting the fixed route are installed in positions that provide a good view of the entire interior of the vehicle. As an example, the terminals constituting the fixed route can be installed in positions that provide a good view of the entire interior of the vehicle, such as on the ceiling, the rear-view mirror, or the floor.

According to the above configuration, even if the communication path is omitted due to overhear, by appropriately transmitting a reception notification, it is possible to provide a wireless communication system etc. that can suppress unnecessary traffic by making the appropriate terminal on the communication path recognize that the wireless communication has ended.

(Example of state transition operation of wireless communication device 100)
An example of state transition operation when the wireless communication device 100 according to this embodiment is in operation will be described with reference to FIG.

In step S601, the wireless communication device 100 determines whether or not there is a request to transmit communication data from the external I/F unit 170. If there is a request to transmit communication data (step S601: YES), the wireless communication device 100 proceeds to step S602. If there is no request to transmit communication data (step S601: NO), the wireless communication device 100 proceeds to step S604.

In step S602, the wireless communication device 100 transmits and receives terminal information to and from other wireless communication devices 100, and updates the terminal information to the latest information. This terminal information update process allows the terminal status to be constantly monitored, enabling stable communication. Next, the wireless communication device 100 proceeds to step S603.

That is, in step S602, the wireless communication device 100 checks the connection status with the other wireless communication devices 100. The connection status may include information such as RSSI (Received Signal Strength Indicator), such as radio wave strength, which indicates communication quality information with the wireless communication device 100. Based on these connection statuses, the wireless communication device 100 updates the terminal information to the latest information. That is, the wireless communication device 100 updates the stored contents of the connection information storage unit 182. The updated contents of the connection information storage unit 182 are shared by all wireless communication devices 100 in the wireless communication system.

In step S603, the wireless communication device 100 transitions to a mode for executing a transmitting terminal process for wireless communication with the wireless communication device of the communication partner indicated in the transmission request information related to the transmission request (see FIG. 7). Then, the wireless communication device 100 transitions to an idle state or S601.

In step S604, the received data determination unit 130 of the wireless communication device 100 determines whether communication data has been received. If communication data has been received (step S604: YES), the wireless communication device 100 proceeds to step S605. If communication data has not been received (step S604: NO), the wireless communication device 100 proceeds to step S606.

In step S605, the wireless communication device 100 determines whether the received communication data is addressed to the wireless communication device itself as a destination terminal, and transitions the state to relay/receive terminal processing for executing various processes based on the determination result (see FIG. 8). The wireless communication device 100 then transitions the state to the idle state or S601.

In step S606, the wireless communication device 100 transmits and receives terminal information to and from other wireless communication devices 100, and updates the terminal information to the latest information. This terminal information update process enables stable communication by constantly monitoring the state of the terminal. The terminal information update process can be performed at time intervals predetermined by the wireless communication system 1000. The terminal information update process may also be performed each time a predetermined event occurs in the wireless communication system 1000. The predetermined event may be when the communication quality of the link state between the wireless communication devices 100 falls below a predetermined value or exceeds a predetermined value. Furthermore, the wireless communication system 1000 can set any value to the predetermined value of the communication quality. The wireless communication system 1000 can set any value to the predetermined value of the communication quality for any parameter such as reception power, reception radio wave intensity, PER, BER, SNR, delay time, and number of hops. Then, the wireless communication device 100 transitions to the idle state or S601.

(Example of operation when wireless communication device 100 operates as a transmitting terminal)
An operation example in which the wireless communication device 100 according to this embodiment operates as a transmitting terminal will be described with reference to FIG.

In step S701, it is determined whether the wireless communication device 100 from which the transmission request has occurred is one of the terminals forming a fixed route. If the wireless communication device 100 from which the transmission request has occurred is one of the terminals forming a fixed route (step S701: YES), the wireless communication device 100 proceeds to step S702. If the wireless communication device 100 from which the transmission request has occurred is not one of the terminals forming a fixed route (step S701: NO), the wireless communication device 100 proceeds to step S705.

In step S702, the own terminal forming the fixed route determines whether a communication link has been established with the destination terminal of the communication data related to the transmission request. If the own terminal forming the fixed route has established a communication link with the destination terminal of the communication data related to the transmission request (step S702: YES), the wireless communication device 100 proceeds to step S703. If the own terminal forming the fixed route has not established a communication link with the destination terminal of the communication data related to the transmission request (step S702: NO), the wireless communication device 100 proceeds to step S704.

In step S703, since the terminal forming the fixed route has established a communication link with the destination terminal of the communication data related to the transmission request, the wireless communication device 100 transmits the communication data to the destination terminal. The wireless communication device 100 ends the transmission process and starts the operation of the flowchart showing the state transitions in Figure 6.

In step S704, since the terminal forming the fixed route has not established a communication link with the destination terminal of the communication data related to the transmission request, the communication data is transferred to another terminal forming the fixed route to which the communication data should be transferred next, according to the terminal information. The wireless communication device 100 ends the transmission process and proceeds to step S601 in FIG. 6.

In step S705, since the wireless communication device 100 from which the transmission request occurred is not one of the terminals forming the fixed route, the wireless communication device 100 from which the transmission request occurred transfers the communication data to one of the terminals forming the fixed route with which a communication link has been established. The wireless communication device 100 ends the transmission process and proceeds to step S601 in FIG. 6.

(Example of operation when wireless communication device 100 operates as a relay/receiving terminal)
An operation example in which the wireless communication device 100 according to this embodiment operates as a relay/receiving terminal will be described with reference to FIG.

In step S801, the wireless communication device 100 determines whether the destination terminal of the received communication data is the wireless communication device 100 itself. If the destination terminal of the received communication data is the wireless communication device 100 itself (step S801: YES), the wireless communication device 100 proceeds to step S802. If the destination terminal of the received communication data is not the wireless communication device 100 itself (step S801: NO), the wireless communication device 100 proceeds to step S806.

In step S802, the wireless communication device 100 executes reception processing of the received communication data because the destination terminal of the received communication data is the wireless communication device 100 itself. The communication data that has been received and processed may be output to an external electronic device via the external I/F unit 170. Next, the wireless communication device 100 proceeds to step S803.

In step S803, the wireless communication device 100 determines the source terminal of the received communication data from the communication data. Also, the wireless communication device 100 that has received the communication data refers to the terminal information and determines whether the previous terminal information matches the source terminal of the received communication data. If the previous terminal information matches the source terminal of the received communication data (step S803: YES), the wireless communication device 100 ends the process and starts the operation of the flowchart showing the state transition in FIG. 6. That is, the wireless communication device 100 does not receive the communication data by overhear, but receives it by an expected regular communication path. If the previous terminal information does not match the source terminal of the received communication data (step S803: NO), the wireless communication device 100 proceeds to step S804. In this case, the wireless communication device 100 receives the communication data by overhear.

In step S804, the reception notification generating unit 140 of the wireless communication device 100 generates a reception notification indicating that the communication data has been normally received by overhear. Next, the wireless communication device 100 proceeds to step S805.

In step S805, the wireless communication device 100 transmits the reception notification generated by the reception notification generating unit 140 to the other wireless communication device 100 that transmitted the communication data received by overhear. Since the terminal information is shared by all wireless communication devices 100 in the wireless communication system 1000, the wireless communication device 100 that overheard can determine the wireless communication device 100 to which the overheard communication data is to be transmitted. Next, the wireless communication device 100 ends the processing and starts the operation of the flowchart showing the state transitions in FIG. 6.

In step S806, the wireless communication device 100 determines whether the destination terminal of the received communication data is another terminal with which a communication link has been established with the wireless communication device 100. If the destination terminal of the received communication data is another terminal with which a communication link has been established with the wireless communication device 100 (step S806: YES), the wireless communication device 100 proceeds to step S807. If the destination terminal of the received communication data is another terminal with which a communication link has not been established with the wireless communication device 100 (step S806: NO), the wireless communication device 100 proceeds to step S808.

In step S807, the wireless communication device 100 transfers the received data to another wireless communication device 100 with which a communication link has been established. Next, the wireless communication device 100 ends the processing and starts the operation of the flowchart showing the state transitions in FIG. 6.

In step S808, the wireless communication device 100 transfers the received data to the next wireless communication device 100 that forms the next fixed route for the own terminal, according to the terminal information of the own terminal. Next, the wireless communication device 100 ends the processing and starts the operation of the flowchart showing the state transitions in Figure 6.

(Variation 1)
In the above embodiment, a network constructed by the wireless communication system 1000 installed in an automobile is described as an example. However, the embodiment is not limited to the inside of an automobile, and can be applied to mesh networks in general constructed inside moving bodies such as trains, airplanes, ships, etc., and inside structures such as houses and factories.

(Variation 2)
In addition, the network topology between the base stations is not limited to the topology shown in Fig. 1, and the network topology between the base stations may be configured in any topology. For example, the network topology between the base stations may be configured as a ring network, a bus network, or a P2P network.

(Variation 3)
In the above embodiment, the wireless communication device 100 that forms the fixed route may be installed in the vehicle body or other periphery within the vehicle, but the installation location of the wireless communication device 100 that forms the fixed route is not limited to these locations. For example, the fixed route may be formed by the wireless communication device 100 installed under the floor, ceiling, or the like of the vehicle that has a radio wave environment that is less susceptible to the influence of the vehicle occupants. The under floor and ceiling may be the interior of the vehicle that is a component that forms the body.

(Variation 4)
In the above description of the embodiment, the wireless communication device 100 forming the fixed route is mainly described as being predetermined in the wireless communication system 1000. However, when the wireless communication system 1000 is started, all the wireless communication devices 100 included in the network may transmit and receive packets for measuring communication quality to each other, and the wireless communication device 100 having good communication quality may be determined as the fixed route. Good communication quality may also refer to a case where the communication quality information is equal to or greater than a predetermined value. The predetermined value is a value that the wireless communication system 1000 may set to any value. The communication quality information may also include information such as RSSI, such as radio wave strength, BER (bit error rate), PER (Packet Error Rate), etc. Furthermore, the communication quality information may also include information such as SNR (Signal to Noise Ration), RCPI (Received Channel Power Indicator), information such as success rate, communication delay time, number of hops, etc. Furthermore, the communication quality may be measured when the wireless communication system 1000 is started up, at a time interval predetermined by the wireless communication system 1000, when communication data is transmitted, or at the time of a predetermined event. Furthermore, the fixed route may be updated at the above measurement timing by the wireless communication device 100 having a good communication quality equal to or higher than a predetermined value. As outlined in the embodiment, the predetermined event may be set when the communication quality between any of the terminals falls below a predetermined value. Furthermore, the fixed route may be set by communication quality information with a high priority set by the wireless communication system 1000.

(Variation 5)
In the above description of the embodiment, no specific data is described as the communication data, but the application is not limited thereto. For example, the communication data may be information of a sensor that detects the state of a moving object, information for controlling the moving object, information of electronic devices mounted on the moving object, and the like. Examples of the sensor include various sensors such as a door opening/closing detection sensor, a seat belt sensor, an engine rotation sensor, a vehicle speed sensor, and a brake or accelerator sensor. Examples of the electronic device include a navigation device, and entertainment devices such as a radio or a television.

(Variation 6)
The transfer direction of the ring-shaped fixed route in Fig. 1 can be set to either a clockwise or counterclockwise direction by the wireless communication system 1000. The arrangement of the wireless communication device 100 of the wireless communication system 1000 is not limited to the above embodiment, and the wireless communication device 100 can be arranged at any position in a predetermined space. However, it is preferable that the wireless communication device 100 has wireless quality equal to or higher than a predetermined value with at least one of the wireless communication devices 100.

Comparative Example
A comparative example will be described with reference to FIG. 9 and FIG.

Figures 9 and 10 are schematic diagrams for explaining the operation of a communication system when a transmitting terminal A, a relay terminal B, a relay terminal C, and a receiving terminal D are present, and a request to transmit communication data is made from transmitting terminal A to receiving terminal D.

Transmitting terminal A directly communicates communication data to receiving terminal D. When receiving terminal D transmits an ACK to transmitting terminal A, transmitting terminal A determines that direct communication to receiving terminal D has been successful, discards the communication data, and ends the transmission operation. If transmitting terminal A does not receive an ACK from receiving terminal D, relay terminal B, which has been overhearing the direct communication, transmits the communication data transmitted from transmitting terminal A to receiving terminal D as a proxy. The proxy communication from relay terminal B to receiving terminal D is called proxy communication D1. In this case, since direct communication to receiving terminal D has not been successful, transmitting terminal A inputs the communication data to a transmission buffer to execute a retransmission process. Therefore, transmitting terminal A enters a state of waiting for retransmission or waiting for notification of completion of proxy communication. Since relay terminal C has not overheard the direct communication, it does not start processing related to the communication data.

If relay terminal B receives an ACK from receiving terminal D in proxy communication D1, relay terminal B determines that proxy communication D1 has been successful, discards the communication data, and transmits a proxy communication completion notification to transmitting terminal A. If relay terminal B does not receive an ACK from receiving terminal D, relay terminal C, which has been overhearing proxy communication D1, transmits the communication data transmitted from relay terminal B to receiving terminal D as a proxy. The proxy communication from relay terminal C to receiving terminal D is called proxy communication D2. In this case, relay terminal B inputs the communication data to a transmission buffer to execute a retransmission process because proxy communication D1 to receiving terminal D has not been successful. Therefore, relay terminal B enters a state of waiting for retransmission or waiting to relay another wireless communication. After retransmission, relay terminal B discards the communication data regardless of whether it has received an ACK from receiving terminal D.

If relay terminal C does not receive an ACK from receiving terminal D in proxy communication D2, relay terminal C determines that proxy communication D2 has failed and inputs the communication data into a transmission buffer to execute retransmission processing. Therefore, relay terminal C enters a state of waiting for retransmission or waiting to relay another wireless communication. After retransmission, relay terminal C discards the communication data regardless of whether it has received an ACK from receiving terminal D. If relay terminal C receives an ACK from receiving terminal D in proxy communication D2, relay terminal C determines that proxy communication D2 has been successful, discards the communication data, and transmits a proxy communication completion notification to transmitting terminal A. The proxy communication completion notification in this case may be referred to as a proxy communication completion notification DS1.

When relay terminal C receives an ACK from transmitting terminal A in the proxy communication completion notification DS1, relay terminal C determines that the wireless communication of proxy communication completion notification DS1 was successful and discards the proxy communication completion notification DS1. Having received proxy communication completion notification DS1 from relay terminal C, transmitting terminal A stops retransmission and discards the communication data. Relay terminal B can determine by overhear that the proxy communication data waiting to be retransmitted was successfully transmitted and received by another terminal, so discards the proxy communication data waiting to be retransmitted.

If relay terminal C does not receive an ACK from transmitting terminal A in the proxy communication completion notification DS1, relay terminal B, which has overheard the proxy communication completion notification DS1, executes the following operation. That is, relay terminal B transmits a proxy communication completion notification DS2 to transmitting terminal A instead of the proxy communication completion notification DS1 transmitted from relay terminal C to transmitting terminal A. Since relay terminal B can determine by overhearing that the proxy communication data waiting to be retransmitted has been successfully transmitted and received by another terminal, it discards the proxy communication data waiting to be retransmitted. In this case, relay terminal C inputs the proxy communication completion notification DS1 to the transmission buffer to execute the retransmission process because the proxy communication completion notification DS1 to transmitting terminal A has not been successful. Therefore, relay terminal C enters a state of waiting for retransmission or waiting to relay another wireless communication. After retransmission, relay terminal C discards the proxy communication completion notification DS1 regardless of whether it has received an ACK from transmitting terminal A or not.

If relay terminal B receives an ACK from transmitting terminal A in the proxy communication completion notification DS2, relay terminal B determines that the wireless communication of the proxy communication completion notification DS2 has been successful and discards the proxy communication completion notification DS2. Since transmitting terminal A has received the proxy communication completion notification DS2 from relay terminal B, it stops retransmission and discards the communication data. If relay terminal B does not receive an ACK from transmitting terminal A in the proxy communication completion notification DS2, relay terminal B determines that the communication of the proxy communication completion notification DS2 has failed and inputs the proxy communication completion notification DS2 into the transmission buffer for retransmission. Therefore, relay terminal B enters a state of waiting for retransmission or waiting to relay another wireless communication. After retransmission, relay terminal B discards the proxy communication completion notification DS2 regardless of whether it has received an ACK from transmitting terminal A.

If transmitting terminal A does not receive a proxy communication completion notification from any terminal, transmitting terminal A executes retransmission of the communication data. When retransmission is executed, the communication system repeats the above operation.

However, while this technology uses overhear to enable reliable communication in a short time by having other terminals proxy the communication, it is highly likely that traffic will increase because it cannot suppress communication between terminals that cannot recognize each other's overhear.

However, according to the present disclosure, even if a communication path is omitted due to overhear, by appropriately transmitting a reception notification, it is possible to provide a wireless communication system etc. that can suppress unnecessary traffic by making the appropriate terminal on the communication path recognize that the wireless communication has ended.

The following describes the features of the wireless communication device 100 and wireless communication system 1000 of this embodiment.

When the wireless communication device 100 capable of configuring an ad-hoc network according to the first aspect of the present disclosure is capable of direct communication with any one of the wireless communication devices forming a fixed route and is not a wireless communication device forming a fixed route, it preferably includes the following configuration. The wireless communication device 100 preferably includes a reception notification generating unit 140 that generates a reception notification of the overheard communication data when the wireless communication device itself overhears communication data for which the destination wireless communication device is the wireless communication device. Furthermore, the wireless communication device 100 preferably includes a wireless transmission unit 190 that transmits a reception notification to a wireless communication device forming a fixed route to which the wireless communication device that transmitted the overheard communication data directly transmitted the communication data.

According to the above configuration, even if the communication path is omitted due to overhear, by appropriately transmitting a reception notification, it is possible to provide a wireless communication system etc. that can suppress unnecessary traffic by making the appropriate terminal on the communication path recognize that the wireless communication has ended.

It is preferable that the wireless communication device 100 according to the second aspect of the present disclosure does not communicate directly with other wireless communication devices that do not form a fixed route.

According to the above configuration, by using a fixed route with good communication quality as the communication path, it may be possible to suppress the occurrence of retransmission processing and route search processing due to deterioration of the communication environment due to the movement of radio wave obstructions such as passengers. Therefore, it may be possible to suppress deterioration of the communication speed and power consumption of the wireless communication system, and it may be possible to improve the communication performance of the wireless communication system.

When a transmission request occurs in the wireless communication device 100 according to the third aspect of the present disclosure, the wireless transmission unit 190 preferably executes the following process. That is, the wireless transmission unit 190 preferably transmits communication data related to the transmission request to one of the wireless communication devices that form a fixed route with which direct communication is possible as the destination wireless communication device.

According to the above configuration, when a transmission request occurs to a wireless communication device outside a fixed route, a fixed route with good communication quality is used, which makes it possible to improve the communication speed and communication reliability of the wireless communication system. In addition, a wireless communication device outside a fixed route can dynamically belong to the communication area of a wireless communication device within one of the fixed routes, which may make it possible to improve the communication performance of the wireless communication system.

The wireless communication device 100 capable of configuring an ad-hoc network according to the fourth aspect of the present disclosure is capable of direct communication with one or more wireless communication devices forming a fixed route, and preferably includes the following configuration when it is one of the wireless communication devices forming a fixed route. The wireless communication device 100 preferably includes a reception notification generating unit 140 that generates a reception notification of the overheard communication data when the wireless communication device itself overhears communication data whose destination wireless communication device is the wireless communication device. Furthermore, the wireless communication device 100 preferably includes a wireless transmission unit 190 that transmits a reception notification to a wireless communication device forming a fixed route to which the wireless communication device that transmitted the overheard communication data directly transmitted the communication data.

According to the above configuration, even if the communication path is omitted due to overhear, by appropriately transmitting a reception notification, it is possible to provide a wireless communication system etc. that can suppress unnecessary traffic by making the appropriate terminal on the communication path recognize that the wireless communication has ended.

When the wireless communication device 100 capable of configuring an ad-hoc network according to the fifth aspect of the present disclosure is any one of the wireless communication devices forming a fixed route, it preferably includes the following configuration. When the wireless communication device 100 receives communication data for which the wireless communication device itself is not the destination wireless communication device, it preferably includes a wireless receiving unit 120 that receives a reception notification of the communication data from the wireless communication device that is the destination wireless communication device. Furthermore, it is preferable that the wireless communication device 100 includes a wireless transmitting unit 190 that, when the wireless receiving unit receives the reception notification, discards the communication data without forwarding the received communication data.

According to the above configuration, even if the communication path is omitted due to overhear, the terminal whose communication should be omitted can receive the reception notification. As a result, the terminal whose communication should be omitted can recognize that the wireless communication has ended, so that unnecessary communication data is not transmitted and unnecessary traffic can be suppressed.

When the wireless receiving unit 120 of the wireless communication device 100 that does not form a fixed route according to the sixth aspect of the present disclosure receives communication data from another wireless communication device, it is preferable to execute the following process. That is, when the destination wireless communication device of the received communication data is a wireless communication device that can directly communicate with the wireless communication device itself, it is preferable that the wireless transmitting unit 190 of the wireless communication device 100 transmits the communication data to the wireless communication device that does not form a fixed route.

The above configuration makes it possible to quickly transmit communication data, whose destination wireless communication device is a wireless communication device in an area where direct communication with the wireless communication device is possible, to a wireless communication device in an area with high communication reliability. Therefore, a wireless communication device having the above configuration makes it possible to improve the communication speed and communication reliability of a wireless communication system.

When the wireless receiving unit 120 of the wireless communication device 100 according to the seventh aspect of the present disclosure receives communication data from another wireless communication device, it is preferable to distinguish between the cases and execute processing as follows. That is, when the destination wireless communication device of the received communication data is not a wireless communication device that does not form a fixed route that allows direct communication with the wireless communication device itself, it is preferable for the wireless transmitting unit 190 to execute the following processing. That is, it is preferable for the wireless transmitting unit 190 to transfer the communication data to a wireless communication device that forms a fixed route adjacent to the wireless communication device itself.

The above configuration makes it possible to quickly transfer communication data that does not have a wireless communication device in an area where direct communication with the wireless communication device is possible as a destination wireless communication device via a fixed route with high communication reliability. Therefore, a wireless communication device having the above configuration makes it possible to improve the communication speed and communication reliability of a wireless communication system.

In accordance with the eighth aspect of the present disclosure, it is preferable that the communication quality between adjacent wireless communication devices that perform direct communication to form a fixed route exceeds a predetermined value. It is also preferable that the communication quality between a wireless communication device that does not form a fixed route and that performs direct communication with a wireless communication device that forms a fixed route, and the wireless communication device that forms the fixed route, also exceeds a predetermined value.

The above configuration makes it possible to maintain the communication quality of wireless communication devices that form fixed routes and wireless communication devices that do not form fixed routes at appropriate values, thereby improving the reliability of communication in the wireless communication system.

A wireless communication system 1000 according to a ninth aspect of the present disclosure preferably includes a wireless communication device 100 according to any one of the first to third aspects that does not form a fixed route, and a wireless communication device 100 according to any one of the fourth to seventh aspects that forms a fixed route. It is preferable that the wireless communication device 100 that does not form a fixed route executes one-to-one direct communication with the wireless communication device 100 that forms a fixed route.

According to the above configuration, even if the communication path is omitted due to overhear, by appropriately transmitting a reception notification, it is possible to provide a wireless communication system etc. that can suppress unnecessary traffic by making the appropriate terminal on the communication path recognize that the wireless communication has ended.

In the wireless communication system 1000 according to the tenth aspect of the present disclosure, it is preferable that the wireless communication device 100 that forms a fixed route and the wireless communication device 100 that does not form a fixed route and executes one-to-one direct communication with the wireless communication device that forms the fixed route are updated. For example, it is preferable that the configuration of the wireless communication system is updated at least one of the following times: when the wireless communication device is started, when a request to transmit electronic data is generated, at a predetermined time interval, or when the communication quality between the wireless communication devices falls below a predetermined value.

With the above configuration, wireless communication devices that form fixed routes and wireless communication devices that do not form fixed routes are updated at appropriate times, making it possible to improve the reliability of communication in the wireless communication system.

The block diagram of FIG. 5 used to explain the above-mentioned embodiment shows functional blocks. These functional blocks are realized by any combination of at least one of hardware and software. Furthermore, the method of realizing each functional block is not particularly limited. For example, each functional block may be realized using one device that is physically or logically coupled, or may be realized using two or more devices that are physically or logically separated and directly or indirectly connected to each other. The functional blocks may be realized by combining software with one device or multiple devices.

When the wireless communication device 100 is composed of multiple hardware elements, each functional block is realized by any one of the hardware elements or a combination of the hardware elements. Examples of hardware elements include a processor, memory, storage, a communication device, an input device, an output device, a bus, etc.

In this case, each function of the wireless communication device 100 is realized by loading a specific software or program onto hardware such as a processor and memory. Specifically, each function is realized by loading specific software onto the hardware, causing the processor to perform calculations and control the reading and writing of data in the memory and storage.

Although the embodiments have been described in detail with reference to the drawings, the present invention is not limited to the contents described in the above embodiments. Furthermore, the components described above include those that a person skilled in the art would easily imagine and those that are substantially the same. Furthermore, the configurations described above can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the configuration can be made without departing from the spirit of the present invention.

REFERENCE SIGNS LIST 100 Wireless communication device 110 Transmitting/receiving section 120 Wireless receiving section 130 Receiving data determining section 140 Reception notification generating section 150 Transmission destination determining section 160 Transmission data generating section 170 External I/F section 180 Storage section 181 Communication data buffer section 182 Connection information storing section 190 Wireless transmitting section 1000 Wireless communication system ANT Antenna section

Claims (10)

A wireless communication device capable of configuring an ad-hoc network,
If the wireless communication device can directly communicate with any one of the wireless communication devices forming a fixed route, and is not a wireless communication device forming the fixed route,
a reception notification generating unit that generates a reception notification of the overheard communication data when the wireless communication device overhears the communication data whose destination wireless communication device is the wireless communication device itself;
a wireless communication device including a wireless transmission unit that transmits the reception notification to a wireless communication device that forms the fixed route and is a party to which the wireless communication device that transmitted the overheard communication data directly transmitted the communication data. The wireless communication device according to claim 1, wherein the wireless communication device does not directly communicate with other wireless communication devices that do not form the fixed route. The wireless communication device according to claim 1 or 2, wherein when a transmission request occurs in the wireless communication device, the wireless transmission unit transmits communication data related to the transmission request to one of the wireless communication devices that form a fixed route that allows direct communication as a destination wireless communication device. A wireless communication device capable of configuring an ad-hoc network,
When the wireless communication device is capable of directly communicating with one or more wireless communication devices forming a fixed route, and is one of the wireless communication devices forming the fixed route,
a reception notification generating unit that generates a reception notification of the overheard communication data when the wireless communication device overhears the communication data whose destination wireless communication device is the wireless communication device itself;
a wireless communication device including a wireless transmission unit that transmits the reception notification to a wireless communication device that forms the fixed route and is a party to which the wireless communication device that transmitted the overheard communication data directly transmitted the communication data. A wireless communication device capable of configuring an ad-hoc network,
When the wireless communication device is one of the wireless communication devices forming a fixed route,
a wireless receiving unit that, when receiving communication data for which the wireless communication device is not a destination wireless communication device, receives a reception notification of the communication data from the wireless communication device that is a destination wireless communication device;
a wireless transmission unit that, when the wireless reception unit receives the reception notification, discards the received communication data without forwarding the communication data. When the wireless receiving unit receives communication data from another wireless communication device, if the destination wireless communication device of the communication data is a wireless communication device that does not form a fixed route capable of direct communication with the wireless communication device,
The wireless communication device according to claim 5 , wherein the wireless transmission unit transmits the communication data to the wireless communication device that does not form a fixed route. When the wireless receiving unit receives communication data from another wireless communication device, if the destination wireless communication device of the communication data is not a wireless communication device that does not form a fixed route capable of direct communication with the wireless communication device itself,
The wireless communication device according to claim 5 or 6, wherein the wireless transmission unit transfers the communication data to the wireless communication device that forms a fixed route adjacent to the wireless communication device itself. a communication quality between the wireless communication device forming the fixed route and another adjacent wireless communication device forming the fixed route, which directly communicates with the wireless communication device forming the fixed route, exceeds a predetermined value;
A wireless communication device as described in any one of claims 1 to 7, wherein the communication quality between a wireless communication device that does not form the fixed route and a wireless communication device that forms the fixed route, which directly communicates with the wireless communication device that forms the fixed route, also exceeds a predetermined value. The wireless communication device according to claim 1 , which does not form a fixed route;
A wireless communication system comprising: a wireless communication device according to any one of claims 4 to 7 that forms the fixed route; and a wireless communication device that does not form the fixed route that performs one-to-one direct communication with the wireless communication device that forms the fixed route. The wireless communication system according to claim 9, wherein the wireless communication device forming the fixed route and the wireless communication device not forming the fixed route that executes one-to-one direct communication with the wireless communication device forming the fixed route are updated at least one of the following times: when the wireless communication device is started, when a request to transmit electronic data is generated, at a predetermined time interval, or when the communication quality between the wireless communication devices falls below a predetermined value.

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