JP2005236460A - Mobile communication system and terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate the need for a dedicated repeater, and to reduce the total cost of the system. <P>SOLUTION: In an inter-vehicle communication system S comprising a plurality of wireless communication units 11 mounted on vehicles 1 and performing wireless communication with each other, the wireless communication unit 11 is arranged to repeat communication data by transmitting the communication data to other wireless communication unit located in its own wireless communication area when the wireless communication unit of communication partner is not located in its own wireless communication area. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to mobile wireless communication, and more particularly to a technique for relaying communication data.

Conventionally, in mobile communication, a plurality of base stations forming a predetermined range of wireless communication areas are arranged so that these wireless communication areas are adjacent to each other, and the base stations are connected by multiple lines. Alternatively, a substantial wireless communication area is expanded by arranging a dedicated relay device for relaying communication data of the mobile terminal (for example, see Patent Document 1).
JP-A-5-30000

  However, in a configuration in which base stations are connected by a dedicated line, it is necessary to arrange a large number of base stations everywhere in the area where the radio communication area should be expanded, and further, multiplexing for communication between base stations Since a separate device is required, there is a problem that the cost of the entire system increases.

  Further, in the configuration in which a dedicated relay device is arranged, there is a problem that procedures such as communication control between the relay device and the mobile terminal and communication control between the relay device and the base station are complicated. is there.

  The present invention has been made in view of the above circumstances, and provides a mobile communication system and a mobile communication terminal that do not require a dedicated relay device and can reduce the cost of the entire system. With the goal.

  In order to achieve the above object, the present invention provides a mobile communication system comprising a plurality of mobile communication terminals, wherein each mobile communication terminal communicates with each other wirelessly, wherein the mobile communication terminal is a wireless communication area of its own terminal. The communication partner mobile communication terminal, and if the communication partner mobile communication terminal is present as a result of the determination by the determination means, the communication partner mobile communication The communication data is transmitted to the terminal, and when the mobile communication terminal of the communication partner is not located, the communication data is transmitted to another mobile communication terminal located within the wireless communication area of the terminal. And communication control means for relaying data.

  In the present invention, the communication control means may be configured so that the communication control means is a mobile communication device that is closest to the mobile communication terminal of the communication partner among other mobile communication terminals located within the wireless communication area of its own terminal. The terminal is configured to relay communication data.

  Further, the present invention is the above invention, wherein the mobile communication terminal includes position acquisition means for acquiring its own position information, and when transmitting communication data, the mobile communication terminal includes identification information assigned to its own terminal and the position information. When the communication data is received, the identification information and the position information included in the received communication data are stored as information of a terminal capable of direct wireless communication.

  Further, the present invention is the above invention, wherein the mobile communication terminal includes position acquisition means for acquiring its own position information, and when transmitting communication data, the mobile communication terminal includes identification information assigned to its own terminal and the position information. When the communication data is received, the identification information and the position information included in the received communication data are paired and stored as information of a terminal capable of direct wireless communication, and the communication control The means specifies a mobile communication terminal that is closest to the mobile communication terminal of the communication partner, based on the stored position information, among other mobile communication terminals that are located within the wireless communication area of the terminal. The communication data is relayed to the specified mobile communication terminal.

  In addition, the present invention is the above invention, wherein each time the mobile communication terminal has received the communication data, the identification information included in the communication data received this time is already stored. The associated position information is updated to the position information included in the communication data received this time, and the identification information included in the communication data received this time is not yet stored. The identification information and the position information included in the communication data are stored as a pair.

  Also, in the present invention according to the above invention, the mobile communication terminal stores the time when the identification information and the position information are stored or the time when the position information is updated as a pair with the identification information and the position information. When the time indicates a certain time before the current time, the time is erased together with identification information and position information corresponding to the time.

  Further, the present invention is the above invention, wherein the determination means of the mobile communication terminal includes the identification information of the mobile communication terminal of the communication partner in the wireless communication area of its own terminal based on whether the identification information is stored. It is characterized by determining whether or not the mobile communication terminal of the communication partner is in the service area.

  Further, the present invention is the above invention, wherein when the mobile communication terminal transmits communication data, a destination field storing identification information and position information of the mobile communication terminal that is a transmission destination of the communication data, and the communication A transmission source field storing identification information and position information of its own terminal that is a data transmission source, and a final destination field storing identification information and position information of a mobile communication terminal that is the final destination of the communication data It is characterized by using at least a radio frame.

  Further, the present invention provides the mobile communication terminal according to the above-mentioned invention, wherein when the mobile communication terminal of the communication partner is in the wireless communication area of its own terminal, the identification information and location information of the mobile terminal of the communication partner are displayed. When storing and transmitting in the destination field and the final destination field and the mobile communication terminal of the communication partner is not located, identification information and position information of the mobile communication terminal that relays communication data are stored in the destination field. And storing and transmitting the identification information and position information of the mobile communication terminal of the communication partner in the final destination field.

  Also, in the present invention according to the above invention, when the mobile communication terminal receives the communication data of the radio frame, identification information of the terminal is stored in the transmission destination field, and further, the mobile communication terminal stores its own identification information in the final destination field. If terminal identification information is not stored, its own identification information and position information are stored in the transmission source field, and a mobile communication terminal corresponding to the identification information of the previous final destination field exists in its own wireless communication area. When the service area is set, the identification information and position information of the final destination field are stored and transmitted in the transmission destination field, and the mobile communication terminal corresponding to the identification information of the previous final destination field is set in its own wireless communication area. When not located, the identification information and location information of the mobile communication terminal to which the communication data should be relayed are sent to the destination field. And transmits stored in field.

  Moreover, the present invention is characterized in that, in the above-mentioned invention, the mobile communication terminal acquires its own position information from a positioning device using GPS.

  According to another aspect of the present invention, there is provided a judging means for judging whether or not a mobile communication terminal of a communication partner is in a wireless communication area of its own terminal in a mobile communication terminal that communicates with other mobile communication terminals by radio. As a result of the determination by the determination means, when the communication partner mobile communication terminal is in the service area, the communication data is transmitted to the communication partner mobile communication terminal and the communication partner mobile communication terminal is not in the service area. Comprises communication control means for transmitting the communication data to another mobile communication terminal located within the wireless communication area of the terminal itself and relaying the communication data.

  According to the present invention, a dedicated relay device is not required, and the cost of the entire system can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram schematically showing a configuration of an inter-vehicle communication system S as a mobile communication system according to the present embodiment. The inter-vehicle communication system S includes a wireless communication device 11 (see FIG. 2) that is a mobile communication terminal mounted on each of a plurality of vehicles 1, and each wireless communication device 11 has a predetermined range in which wireless communication is possible ( In the wireless communication area, the wireless communication devices 11 communicate with each other wirelessly.

  FIG. 2 is a block diagram illustrating a schematic configuration of the in-vehicle system Sa mounted on the vehicle 1. As shown in this figure, the in-vehicle system Sa includes a vehicle control device 12, the wireless communication device 11, and an antenna 13 connected to the wireless communication device 11.

  The vehicle control device 12 acquires, for example, vehicle position information obtained from a car navigation system (not shown) using GPS (Global Positioning System), temporarily stores it, and manages the position information. The data is output to the wireless communication device 11. In addition to the position information, the vehicle control device 12 can also acquire various vehicle information such as vehicle speed information obtained from a vehicle speed meter (not shown) and brake information obtained from a brake pedal sensor (not shown). Can be done.

  FIG. 3 is a block diagram illustrating a configuration of the wireless communication device 11. As shown in the figure, the wireless communication device 11 includes a CPU 101, a memory 102, a data link unit 103, a modem unit 104, and an RF unit 105.

  The CPU 101 performs overall control of the wireless communication device 11. For example, the CPU 101 stores received data in the memory 102, calls transmission data from the memory 102, and determines carrier wave detection in wireless communication. The CPU 101 also executes processing such as acquiring various data such as vehicle position information from the vehicle control device 12 via an interface (not shown) and storing the data in the memory 102.

  The memory 102 stores a control program executed by the CPU 101, various data, variables, and the like. These data include data received by wireless communication and data such as the position information from the vehicle control device 12, and function as a buffer for temporarily storing these data.

  The data link unit 103 executes generation and control of a radio frame that conforms to the inter-vehicle communication protocol. The modem unit 104 modulates a transmission data signal or demodulates a reception data signal. The RF (high frequency) unit 105 transmits and receives data signals, and includes, for example, a PLL (Phase Locked Loop) circuit, an AGC (Auto Gain Control) circuit, an amplifier circuit, and the like. Note that the modem unit 104 and the RF unit 105 are configured to conform to a wireless communication method (for example, a spread spectrum communication method or the like) applied to the inter-vehicle communication system S of the present embodiment. Under such a configuration, the wireless communication device 11 performs bidirectional communication such as transmitting communication data to a wireless communication device of another vehicle and receiving communication data from another wireless communication device.

  By the way, as described above, the wireless communication device 11 forms a wireless communication area, and is capable of directly communicating with other wireless communication devices in the wireless communication area, and any countermeasures are taken. Otherwise, communication with a wireless communication device outside the wireless communication area becomes impossible.

  In addition, when a relay device that relays communication data of the wireless communication device 11 is used in the inter-vehicle communication system S in order to expand the wireless communication area, communication control between the relay device and the wireless communication device 11 can be performed. The problem that it becomes complicated arises.

  Therefore, in the inter-vehicle communication system S of the present embodiment, when the wireless communication device 11 transmits communication data to a first wireless communication device that is not capable of direct wireless communication, direct wireless communication is possible, and the first The communication data is transmitted to a second wireless communication device capable of direct wireless communication with the wireless communication device, and the second wireless communication device is configured to relay the communication data. Hereinafter, this configuration will be described in detail.

  FIG. 4 is a diagram schematically showing a configuration of a radio frame used in the inter-vehicle communication system S of the present embodiment. In this figure, only the portion related to the relay of communication data in the radio frame is shown.

  As shown in the figure, the radio frame 200 has three fields: a destination field 200a, a transmission source field 200b, and a final destination field 200c. The destination field 200a is a field in which identification information that uniquely identifies a transmission destination of communication data and current position information of a wireless communication device corresponding to the transmission destination are stored. The transmission source field 200b is a field in which identification information for uniquely specifying a communication data transmitter and current position information of a wireless communication device corresponding to the transmission source are stored. The final destination field 200c is a field in which identification information for uniquely specifying the final destination of communication data and the current position information of the wireless communication device corresponding to the final destination are stored. The transmission source field 200d is a field in which identification information for uniquely specifying the transmission source that originally transmitted the communication data and position information are stored.

  That is, when a certain wireless communication device 11a transmits communication data to a wireless communication device 11c that is not capable of direct wireless communication, when the communication data is relayed to the wireless communication device 11b capable of direct wireless communication, as shown in FIG. The field 200a stores identification information and position information of the wireless communication device 11b that is the transmission destination of the communication data, and the transmission source field 200b stores identification information and position of the wireless communication device 11a that is the transmission source of the communication data. Information is stored. The final destination field 200c stores identification information and position information of the wireless communication device 11c that is the final destination of the communication data, and the transmission source field 200d is the transmission source that originally transmitted the communication data. The identification information and position information of the wireless communication device 11a are stored.

  When the wireless communication device 11b as the transmission destination receives the wireless frame 200, based on the identification information stored in the final destination field 200c, the wireless frame 200 is addressed to the own device 11b or other wireless communication. Determine if it should be sent to the device. In this wireless frame 200, since the identification information of the other wireless communication device 11c is stored in the final destination field 200c, the wireless frame 200 is stored in the wireless communication device 11c specified in the final destination field 200c. As a result, the communication data reaches the wireless communication device 11c.

  Further, when transmitting the communication data to the wireless communication device 11c, the wireless communication device 11b transmits the identification information and position information of the wireless communication device 11c in each of the destination field 200a and the final destination field 200c as shown in FIG. At the same time, the identification information and position information of the own device 11b are stored in the transmission source field 200b.

  When the wireless communication device 11c as the transmission destination receives this wireless frame 200, the own device 11c is designated in the final destination field 200c, and therefore it is necessary to relay the wireless frame 200 to another wireless communication device. It can be judged that there is no.

  Note that the wireless communication device 11 is not configured to determine whether or not to relay communication data based on information stored in the final destination field 200c, and a dedicated field for storing information indicating whether or not relaying is necessary is a wireless field. It is good also as a structure provided in the flame | frame 200. FIG.

  As described above, in the present embodiment, since the wireless frame 200 is configured to store the identification information and the position information of the wireless communication device that is the transmission destination and the final destination, the wireless communication device 11 acquires the information. Need to be. Therefore, in the present embodiment, the wireless communication device 11 stores in advance the peripheral terminal table 210 in which identification information and position information of wireless communication devices capable of direct wireless communication are registered in the memory 102 and transmits communication data. Is stored with reference to the peripheral terminal table 210 in the fields 200 a to 200 d of the radio frame 200.

  FIG. 7 is a diagram schematically showing the configuration of the peripheral terminal table 210. As shown in this figure, one record of the peripheral terminal table 210 includes a number 210a, identification information 210b, position information 210c, and time 210d. The number 210a is information for identifying each record, and is used when referring to each record, for example. The identification information 210b is information that uniquely identifies a wireless communication device capable of direct wireless communication, and corresponds to identification information stored in each field 200a to 200d of the wireless frame 200. The position information 210c is information indicating the current position of a wireless communication device capable of direct wireless communication. The time 210d is information indicating the time when the record is registered or updated.

  As the identification information 210b, for example, a MAC (Media Access Control) address assigned in advance to a communication device can be used. Further, as the position information 210c, for example, latitude / longitude information, an address, or system-specific information for specifying the position of the wireless communication device 11 can be used. In the present embodiment, as described above, the vehicle control device 12 is configured to acquire position information of the host vehicle 1 from a car navigation system (not shown) using, for example, GPS (Global Positioning System), and the wireless communication device 11 is configured to use the position information. Further, as the time 210d, a timer circuit or a timer circuit (not shown) built in the wireless communication device 11, time information obtained from another device, or the like can be used.

  Such registration or update of the record in the peripheral terminal table 210 is performed by receiving the radio frame 200. Specifically, the wireless communication device 11 sequentially receives receivable wireless frames 200 as well as the wireless frame 200 addressed to itself 11. Since the wireless communication device 11 can directly communicate with the wireless communication device that is the transmission source of the wireless frame 200, the wireless communication device 11 performs the peripheral terminal table processing shown below each time the wireless frame 200 is received, and Based on the information stored in the transmission source field 200b of the frame 200, a wireless communication device capable of direct communication is registered or updated in the peripheral terminal table 210.

  FIG. 8 is a flowchart showing such peripheral terminal table processing. As shown in this figure, when the wireless frame 200 is received, the CPU 101 of the wireless communication device 11 transmits transmission source information such as identification information of the wireless communication device that is the transmission source to the transmission source field of the wireless frame 200 received this time. Read from 200b (step S101). Next, the CPU 101 searches each record in the peripheral terminal table 210 using the identification information of the transmission source as a search key, and determines whether or not the corresponding record already exists (step S102).

  As a result of the determination, if the identification information of the transmission source is not yet registered in the peripheral terminal table 210 (step S102: No), the CPU 101 acquires an unused number 210a in the peripheral terminal table 210 (step S103). The identification information of the transmission source is stored in the record with the number 210a, and this record is registered in the peripheral terminal table 210 (step S104). As a result, a record of a wireless communication device capable of direct communication is newly generated and registered in the peripheral terminal table 210.

  On the other hand, as a result of the determination in step S102, when the identification information of the transmission source is already registered in the peripheral terminal table 210 (step S102: Yes), the CPU 101 stores the position information 210c included in the corresponding record. In order to update with the information included in the radio frame 200 received this time, the record number 210a is acquired (step S105).

  Next, the CPU 101 reads the location information of the source wireless communication device from the source field 200b of the radio frame 200 received this time (step S106), and records the location information of the source in step S104, or Then, it is stored in the record corresponding to the number 210a acquired in step S105 (step S107).

  The CPU 101 acquires the current time (step S108), and stores the time in the record registered in step S104 or the record corresponding to the number 210a acquired in step S105, as in step S107. (Step S109).

  Through the peripheral terminal table processing described above, wireless communication devices that are located in the wireless communication service area of the wireless communication device 11 and are capable of direct wireless communication are sequentially registered or updated in the peripheral terminal table 210.

  By the way, in the peripheral terminal table processing, since the information of each record in the peripheral terminal table 210 is updated based on the information included in the received wireless frame 200, the wireless communication device that has already moved away from the wireless communication area. Even if there is, there will be continued registration in the peripheral terminal table 210 as it is. Therefore, the wireless communication device 11 according to the present embodiment performs wireless communication that is determined to have moved away from the wireless communication area by intermittently executing the following peripheral terminal table update process (for example, every 5 seconds). A record relating to the device is deleted from the peripheral terminal table 210.

  FIG. 9 is a flowchart showing the peripheral terminal table update process. As shown in this figure, the CPU 101 of the wireless communication device 11 reads one record from the peripheral terminal table 210 (step S201), and registers the record based on the time 210d (see FIG. 7) included in the record. Alternatively, it is determined whether a predetermined time (for example, 5 seconds) has elapsed from the updated time, and it is determined whether the information of the record is old (step S202).

  If the information is old (step S202: Yes), it is considered that the reliability of the information registered in the record is low and the wireless communication device registered in the record has already moved away from the wireless communication area. The record is deleted from the peripheral terminal table 210 (step S203). If the determination has not been completed for all the records in the peripheral terminal table 210 (step S204: No), the CPU 101 returns the processing procedure to step S201 to determine the remaining records. Also, as a result of the determination in step S202, even if the record information is not old (step S202: No), if all the records in the peripheral terminal table 210 have not been determined (step S204: No), the CPU 101 In order to determine the remaining records, the processing procedure returns to step S201.

  By this peripheral terminal table update process, information on wireless communication devices that have already been moved out of the wireless communication area is deleted from the peripheral terminal table 210, and only wireless communication devices capable of direct communication are registered in the peripheral terminal table 210. The Rukoto.

  Next, the operation when the wireless communication device 11 transmits communication data using the wireless frame 200 and the peripheral terminal table 210 will be specifically described. When transmitting the communication data, the wireless communication device 11 executes the following wireless route selection process to receive the communication data (that is, when the wireless communication device that is the final destination) is not capable of direct communication. Selects a wireless communication device to which the communication data is to be relayed from wireless communication devices capable of direct communication, and transmits the communication data to the wireless communication device.

  FIG. 10 is a flowchart showing such a wireless route selection process. As shown in this figure, when transmitting communication data, the CPU 101 of the wireless communication device 11 searches the identification information of the wireless communication device to determine whether the wireless communication device that is the final destination can directly communicate. As a key, the peripheral terminal table 210 stored in the memory 102 of the own device 11 is searched (step S301). In the present embodiment, the wireless communication device 11 has a configuration in which identification information and position information of a wireless communication device that can be a communication partner (final destination) are stored in the memory 102 in advance. Will be described later.

  As a result of this search, if the wireless communication device as the final destination is registered in the peripheral terminal table 210 (step S302: in the table), the wireless communication device can communicate directly with this wireless communication device, and other wireless communication devices Indicates that there is no need to relay communication data. Therefore, the CPU 101 reads out the identification information and position information of the wireless communication device from the peripheral terminal table 210 and stores them in the destination field 200a and the final destination field 200c of the wireless frame 200, and the identification information and position information of the device 11 itself. Is stored in the transmission source field 200b to generate the radio frame 200 (step S303) and transmit it.

  On the other hand, if the result of the search in step S303 is that the wireless communication device that is the final destination is not registered in the peripheral terminal table 210 (step S302: not in the table), direct communication with this wireless communication device is not possible and other wireless devices are not available. Indicates that relaying of communication equipment is required. Therefore, the CPU 101 of the wireless communication device 11 executes processing for selecting a wireless communication device suitable for relaying communication data from the wireless communication devices registered in the peripheral terminal table 210.

  In this embodiment, when communication data is relayed to a wireless communication device capable of direct communication, a wireless communication device that is closest to the wireless communication device that is the final destination in terms of a linear distance is selected. Specifically, the CPU 101 of the wireless communication device 11 sequentially obtains a linear distance between each wireless communication device registered in the peripheral terminal table 210 and the final destination wireless communication device based on the position information (step S304). ). Next, the CPU 101 obtains a wireless communication device having the shortest distance from the final destination wireless communication device based on the straight distance thus obtained (step S305), and relays communication data to the wireless communication device. The identification information and position information of the wireless communication device are stored in the destination field 200a, and the identification information and position information of the wireless communication device that should finally receive the communication data are stored in the final destination field 200c. The wireless frame 200 storing the identification information and position information of the device 11 in the field 200b and the transmission source field 200d is generated (step S306) and transmitted.

  When the wireless communication device 11 transmits communication data by this wireless route selection processing, if the final destination wireless communication device can communicate directly, the communication data is directly transmitted to the wireless communication device, and direct communication is performed. If not possible, a wireless communication device having the shortest distance from the final destination wireless communication device is selected from the wireless communication devices capable of direct communication, and communication data is relayed to the wireless communication device.

  FIG. 11 is a diagram schematically illustrating a communication data transmission operation of the wireless communication device 11. In this figure, there are three wireless communication devices B, H, and K in the wireless communication area 300 of the wireless communication device A, and the wireless communication device C is outside the wireless communication area 300. Indicates the case where it exists. Moreover, the point (*) shown in this figure shows the minimum unit of distance used in the inter-vehicle communication system S of the present embodiment.

  In the schematic diagram shown in FIG. 11, since the wireless communication devices B, H, and K are in the wireless communication area 300 of the wireless communication device A, the peripheral terminal table 210 of the wireless communication device A includes these The identification information and position information of the three wireless communication devices B, H, and K are stored.

  At this time, for example, when the wireless communication device A receives the wireless frame 200 transmitted from the wireless communication device K and the wireless communication device C is designated in the final destination field 200c of the wireless frame 200, the wireless communication device A Since the wireless communication device C is not registered in the peripheral terminal table 210, the wireless frame 200 is relayed to other wireless communication devices.

  Therefore, the wireless communication device A determines the three-square theorem as the wireless communication device having the shortest distance from the wireless communication device C that is the final destination among the wireless communication devices B, H, and K registered in the peripheral terminal table 210. The corresponding wireless communication device is identified as the wireless communication device B, and the wireless frame 200 is transmitted to the wireless communication device B. As a result, the wireless frame 200 is relayed by the wireless communication device B and reaches the wireless communication device C.

  In this operation example, the wireless communication device K transmits a wireless frame 200 with a wireless communication device C that is not capable of direct communication as a final destination. Information on the wireless communication device C that is the final destination is wireless communication in advance. It is stored in the memory 102 of the device K.

  Specifically, each of the wireless communication devices 11 is configured to list identification information and position information of wireless communication devices that can be final destinations of communication data and store them in the memory 102 in advance as a terminal list (not shown). . This terminal list is configured so that the user can perform setting, registration, deletion, and the like by operating an input device (not shown) provided in the wireless communication device 11 (for example, a keyboard). In addition, it is good also as a structure which stores this terminal list in the vehicle control apparatus 12, the wireless communication apparatus 11 refers to the data of a terminal list via the vehicle control apparatus 12, and provides an input device in the vehicle control apparatus 12.

  This terminal list includes the name of the wireless communication device, the identification information, the position information, and the like for facilitating the identification of the wireless communication device by the user, and these information are initially registered. Among these, the location information is registered / updated when receiving wireless data from the corresponding wireless communication device.

  For example, when a plurality of users divide and move on a plurality of vehicles 1, the names and identification information of the wireless communication devices mounted on those vehicles 1 are stored in the terminal list of each wireless communication device 11. Register in advance. Then, since each wireless communication device can directly communicate with each other once they gather at the meeting place, each wireless communication device is in the peripheral terminal table 210 as a wireless communication device capable of direct wireless communication. Register the communication device. At this time, if the wireless communication device registered in the peripheral terminal table 210 is also registered in the terminal list, each wireless communication device also registers / updates the location information of the terminal list for the wireless communication device. Thereby, the information on the wireless communication device registered in the terminal list is constantly updated to the latest information, and each wireless communication device 11 can be used as the final destination information at the time of wireless communication.

  In the present embodiment, the case where only the wireless communication devices 11 mounted on the vehicle 1 communicate with each other is illustrated. However, the present invention is not limited to this, and the wireless communication device 11 is, for example, a wireless terminal installed at the user's home. It is good also as a structure which communicates with these. In this configuration, when a user registers a home wireless terminal in the terminal list, when the wireless communication device 11 mounted on the vehicle 1 is activated, the wireless communication device 11 can directly wirelessly communicate with the wireless terminal. While registering in the peripheral terminal table 210 as a terminal, the location information of the wireless terminal is registered / updated in the terminal list.

  As described above, according to the present embodiment, the wireless communication device 11 determines whether or not the wireless communication device of the communication partner is within its own wireless communication area, and the communication partner, that is, the final destination. When the wireless communication device to be used is not located, the dedicated relay device is configured to transmit the communication data to the other wireless communication device located within its own wireless communication area and relay the communication data. Therefore, it is possible to reduce the cost of the entire system.

  Further, according to the present embodiment, the wireless communication device 11 has the peripheral terminal table 210 in which wireless communication devices capable of direct communication are registered, and the peripheral terminal table 210 is updated by receiving normal communication data. And since it was set as the structure which selects the radio | wireless communication apparatus optimal for relaying from the radio | wireless communication apparatus registered into this peripheral terminal table 210, the extra communication regarding relay of communication data becomes unnecessary, and it is to a radio | wireless communications system. Can be reduced.

  In particular, in recent years, as a technique that does not require a specific relay device, data that lists communication terminals that can be directly communicated with each communication terminal is transmitted into the communication system, and each terminal transmits the data when communication data is transmitted. Although techniques such as referencing have been proposed, in this technique, the communication volume increases because each communication terminal individually transmits list data, and the application to a mobile communication system is difficult. There's a problem.

  On the other hand, according to the present embodiment, each of the wireless communication devices 11 that are mobile communication terminals is optimal for the function of sequentially registering and updating information of wireless communication devices capable of direct communication, and transmission of communication data. Therefore, it is possible to prevent an increase in communication volume and to easily configure a mobile communication system having a relay function.

  The above-described embodiment shows one aspect of the present invention, and it is needless to say that the embodiment can be arbitrarily modified and applied within the scope of the present invention. For example, in the above-described embodiment, the case where the present invention is applied to the wireless communication device 11 mounted on the vehicle 1 is illustrated. However, the present invention is not limited to this, for example, for communication between mobile communication terminals such as a mobile phone, The present invention can be applied.

It is a figure which shows schematically the structure of the communication system between vehicles concerning embodiment of this invention. It is a block diagram which shows schematic structure of the vehicle-mounted system mounted in a vehicle. It is a block diagram which shows the functional structure of a radio | wireless communication apparatus. It is a figure which shows typically the structure of the radio | wireless frame used for a communication system between vehicles. It is a figure which shows typically the structure of the radio | wireless frame used for a communication system between vehicles. It is a figure which shows typically the structure of the radio | wireless frame used for a communication system between vehicles. It is a figure which shows the structure of a periphery terminal table typically. It is a flowchart of a peripheral terminal table process. It is a flowchart of a peripheral terminal table update process. It is a flowchart of a wireless route selection process. It is a figure for demonstrating transmission operation | movement of the communication data of a radio | wireless communication apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Roadside apparatus 11, 11a-11c, AC, H, K Wireless communication apparatus 12 Vehicle control apparatus 101 CPU (judgment means, communication control means)
102 memory 200 radio frame 200a destination field 200b source field 200c final destination field 200d source field 210 peripheral terminal table 210b identification information 210c position information S inter-vehicle communication system

Claims (12)

In a mobile communication system comprising a plurality of mobile communication terminals, each mobile communication terminal communicating with each other wirelessly,
The mobile communication terminal is
A determination means for determining whether or not the mobile communication terminal of the communication partner is in the wireless communication area of its own terminal;
As a result of the determination by the determination means, when the communication partner mobile communication terminal is in the service area, the communication data is transmitted to the communication partner mobile communication terminal, and the communication partner mobile communication terminal is not in the service area. And a communication control means for transmitting the communication data to another mobile communication terminal residing in the wireless communication area of the terminal and relaying the communication data. The communication control means relays communication data to a mobile communication terminal that is closest to the mobile communication terminal of the communication partner, among other mobile communication terminals that are located within the wireless communication area of the terminal. The mobile communication system according to claim 1, wherein The mobile communication terminal is
Provided with position acquisition means for acquiring own position information,
When transmitting communication data, including the identification information assigned to its own terminal and the location information,
3. When receiving communication data, the identification information and the position information included in the received communication data are stored as information on a terminal capable of direct wireless communication. Mobile communication system. The mobile communication terminal is
Provided with position acquisition means for acquiring own position information,
When transmitting communication data, including the identification information assigned to its own terminal and the location information,
When the communication data is received, the identification information and the position information included in the received communication data are paired and stored as information on a terminal capable of direct wireless communication,
Based on the stored location information, the communication control means selects a mobile communication terminal that is closest to the mobile communication terminal of the communication partner, among other mobile communication terminals that are located within the wireless communication area of the terminal. The mobile communication system according to claim 1, wherein the communication data is relayed to the specified mobile communication terminal. The mobile communication terminal is
Each time communication data is received, if the identification information included in the communication data received this time is already stored, the position information associated with the corresponding identification information is included in the communication data received this time. Update to the location information
If the identification information included in the communication data received this time is not yet stored, the identification information and the position information included in the communication data received this time are stored as a pair. Item 5. The mobile communication system according to Item 3 or 4. The mobile communication terminal is
The time when the identification information and the position information are stored or the time when the position information is updated is stored as a pair with the identification information and the position information, and
The mobile communication system according to claim 5, wherein when the time indicates a certain time before the current time, the time is erased together with identification information and position information corresponding to the time. The determination means of the mobile communication terminal is:
Determining whether or not the mobile communication terminal of the communication partner is in the wireless communication area of the terminal based on whether or not the identification information of the mobile communication terminal of the communication partner is stored. The mobile communication system according to claim 6, wherein When the mobile communication terminal transmits communication data,
A destination field in which identification information and location information of the mobile communication terminal that is the transmission destination of the communication data are stored;
A transmission source field in which identification information and location information of the terminal serving as a transmission source of the communication data are stored;
The mobile unit according to any one of claims 3 to 6, wherein a radio frame having at least a final destination field storing identification information and position information of a mobile communication terminal that is a final destination of the communication data is used. Communications system. The mobile communication terminal is
When the mobile communication terminal of the communication partner is located in the wireless communication area of its own terminal, the identification information and the position information of the mobile terminal of the communication partner are stored in the destination field and the final destination field and transmitted. ,
When the communication partner mobile communication terminal is not located, the identification information and position information of the mobile communication terminal relaying communication data are stored in the destination field, and the identification information and position of the communication partner mobile communication terminal are stored. The mobile communication system according to claim 8, wherein information is stored in the final destination field and transmitted. The mobile communication terminal is
When communication data of the wireless frame is received,
If the identification information of the terminal is stored in the destination field, and the identification information of the terminal is not stored in the final destination field,
Storing its own identification information and location information in the source field;
When the mobile communication terminal corresponding to the identification information of the previous final destination field is located in its own wireless communication area, the identification information and position information of the final destination field are stored and transmitted in the transmission destination field, and transmitted.
When the mobile communication terminal corresponding to the identification information of the previous final destination field is not located in its own wireless communication area, the identification information and position information of the mobile communication terminal to which the communication data should be relayed are stored in the transmission destination field The mobile communication system according to claim 9, wherein the mobile communication system is transmitted. The mobile communication terminal is
The mobile communication system according to any one of claims 3 to 10, wherein its own position information is acquired from a positioning device using GPS. In mobile communication terminals that communicate wirelessly with other mobile communication terminals,
A determination means for determining whether or not the mobile communication terminal of the communication partner is in the wireless communication area of its own terminal;
As a result of the determination by the determination means, when the communication partner mobile communication terminal is in the service area, the communication data is transmitted to the communication partner mobile communication terminal, and the communication partner mobile communication terminal is not in the service area. A mobile communication terminal comprising: communication control means for transmitting the communication data to another mobile communication terminal residing in the wireless communication area of its own terminal and relaying the communication data.

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