JP5895219B2 - Control device - Google Patents

Description

  The present invention relates to a communication technique, and more particularly to a control device that notifies a signal including predetermined information.

  Road-to-vehicle communication is being studied to prevent collisions at intersections. In the road-to-vehicle communication, information on the situation of the intersection is communicated between the roadside device and the vehicle-mounted device. Road-to-vehicle communication requires the installation of roadside equipment, which increases labor and cost. On the other hand, if it is the form which communicates information between vehicle-to-vehicle communication, ie, onboard equipment, installation of a roadside machine will become unnecessary. In that case, for example, the current position information is detected in real time by GPS (Global Positioning System), etc., and the position information is exchanged between the vehicle-mounted devices so that the own vehicle and the other vehicle enter the intersection respectively. (See, for example, Patent Document 1). In order to prevent a collision accident between the vehicle and the pedestrian, the pedestrian is caused to carry the wireless device. Furthermore, the degree of danger is determined from the GPS information of the pedestrian and the vehicle, and notification to the pedestrian and the driver is made (for example, see Patent Document 2).

JP 2005-202913 A JP 2004-220143 A

  In a wireless LAN (Local Area Network) conforming to a standard such as IEEE 802.11, an access control function called CSMA / CA (Carrier Sense Multiple Access Collision Aviation) is used. Therefore, in the wireless LAN, the same wireless channel is shared by a plurality of terminal devices. In such CSMA / CA, a packet signal is transmitted after confirming that no other packet signal is transmitted by carrier sense. When applying a wireless LAN to inter-vehicle communication such as ITS (Intelligent Transport Systems), it is necessary to transmit information to terminal devices mounted on each of an unspecified number of vehicles. It is desirable that As a result, the terminal device receives the broadcast signal, thereby detecting the approach of another vehicle and alerting the driver to prevent a collision accident between the vehicles.

  Further, in order to notify the driver of information via a network such as traffic jam information, it is desired to execute road-to-vehicle communication in addition to vehicle-to-vehicle communication. Furthermore, it is desired to prevent a collision accident between a pedestrian and the vehicle while preventing a collision accident between vehicles. In order to realize the former, it is necessary to suppress collision of packet signals between vehicle-to-vehicle communication and road-to-vehicle communication. On the other hand, in the latter, for example, a wireless device is carried by a pedestrian such as an elementary school student. In that case, when the number of pedestrians increases, the collision probability of packet signals further increases. Moreover, since the wireless device carried by the pedestrian is battery-driven, if the remaining battery level is low, the driver cannot be notified of the presence of the pedestrian. Therefore, efficient broadcast transmission is desired.

  The present invention has been made in view of such a situation, and an object thereof is to provide a technique for efficiently executing broadcast transmission.

  In order to solve the above problems, a control device according to an aspect of the present invention includes a receiving unit that receives signals broadcast from a plurality of wireless devices, and a plurality of wireless devices based on signals received by the receiving unit. The selection part which selects either of these is provided. The selection unit selects a wireless device that is likely to have a longer signal notification duration.

  Another embodiment of the present invention is also a control device. This device includes a receiving unit that receives signals broadcast from a plurality of wireless devices, and a selection unit that selects one of the plurality of wireless devices based on the signals received by the receiving unit. The signal received by the reception unit includes the position information of the wireless device that is a notification source, and the selection unit is based on the position information received by the reception unit and is present at a highly dangerous position. Select.

  Yet another embodiment of the present invention is also a control device. This device includes a receiving unit that receives signals broadcast from a plurality of wireless devices, and a selection unit that selects one of the plurality of wireless devices based on the signals received by the receiving unit. The selection unit selects a wireless device that has a transmission function and does not have a reception function.

  It should be noted that any combination of the above-described constituent elements and a conversion of the expression of the present invention between a method, an apparatus, a system, a recording medium, a computer program, etc. are also effective as an aspect of the present invention.

  According to the present invention, broadcast transmission can be executed efficiently.

It is a figure which shows the structure of the communication system which concerns on Example 1 of this invention. It is a figure which shows the structure of the base station apparatus of FIG. FIGS. 3A to 3D are diagrams showing frame formats defined in the communication system of FIG. FIGS. 4A to 4B are diagrams illustrating the configuration of the subframes of FIGS. 3A to 3D. It is a figure which shows the structure of the vehicle-mounted terminal device mounted in the vehicle of FIG. It is a figure which shows the structure of the grouping execution part of FIG. FIGS. 7A and 7B are diagrams showing data formats used in the communication system of FIG. It is a figure which shows the structure of the portable terminal device carried by the pedestrian of FIG. It is a sequence diagram which shows the setting procedure of the group by the communication system of FIG. It is a flowchart which shows the setting procedure of the group by the vehicle-mounted terminal device of FIG. It is a flowchart which shows the setting procedure of the group by the portable terminal device of FIG. It is a sequence diagram which shows the setting procedure of another group by the communication system of FIG. It is a flowchart which shows the return procedure from the slave by the portable terminal device of FIG. It is a sequence diagram which shows the setting procedure of another group by the communication system of FIG. It is a flowchart which shows the setting procedure of another group by the vehicle-mounted terminal device of FIG. It is a figure which shows the outline | summary of grouping area formation in the communication system which concerns on Example 2 of this invention. It is a sequence diagram which shows the 1st pattern of the setting procedure of the group in the communication system of FIG. It is a sequence diagram which shows the 2nd pattern of the setting procedure of the group in the communication system of FIG. It is a sequence diagram which shows the 3rd pattern of the setting procedure of the group in the communication system of FIG. It is a sequence diagram which shows the 4th pattern of the setting procedure of the group in the communication system of FIG. It is a sequence diagram which shows the 5th pattern of the setting procedure of the group in the communication system of FIG. It is a sequence diagram which shows the 6th pattern of the setting procedure of the group in the communication system of FIG. It is a sequence diagram which shows the 7th pattern of the setting procedure of the group in the communication system of FIG. It is a sequence diagram which shows the 8th pattern of the setting procedure of the group in the communication system of FIG. It is a figure which shows the outline | summary of grouping area formation in the communication system which concerns on Example 4 of this invention. It is a flowchart which shows the setting procedure of the group by the portable terminal device of FIG. FIGS. 27A and 27B are diagrams illustrating an outline of another grouping area formation in the communication system according to the fourth embodiment of the present invention. It is a flowchart which shows the setting procedure of the group by the vehicle-mounted terminal device of Fig.27 (a)-(b). FIGS. 29A to 29C are diagrams illustrating an outline of grouping area formation in the communication system according to the fifth embodiment of the present invention. It is a flowchart which shows the setting procedure of another group by the vehicle-mounted terminal device which concerns on Example 5 of this invention. It is a figure which shows the outline | summary of another grouping area formation in the communication system which concerns on Example 5 of this invention. It is a flowchart which shows the setting procedure of another group by the vehicle-mounted terminal device which concerns on Example 5 of this invention.

Example 1
Before describing the present invention in detail, an outline will be described. Embodiment 1 of the present invention relates to a communication system that executes vehicle-to-vehicle communication between terminal devices mounted on a movable vehicle and also executes road-to-vehicle communication from a base station device installed at an intersection or the like to a terminal device. . The terminal device may be mounted on a vehicle or carried by a pedestrian. Therefore, in the following description, the inter-vehicle communication and the road-to-vehicle communication may include a terminal device carried by a pedestrian. Furthermore, a terminal device mounted on a vehicle is called an “in-vehicle terminal device”, and a terminal device carried by a pedestrian is called a “portable terminal device”. It shall be collectively referred to as “terminal device”. As inter-vehicle communication, the terminal device broadcasts and transmits a packet signal storing information such as the speed or position of the vehicle or walking (hereinafter referred to as “data”). Further, the other terminal device receives the packet signal and recognizes the approach of the vehicle based on the data. The driver is alerted by notifying the driver of the approaching vehicle or pedestrian.

  In order to reduce interference between vehicle-to-vehicle communication and road-to-vehicle communication, the base station apparatus repeatedly defines a frame including a plurality of subframes. The base station apparatus selects any of a plurality of subframes for road-to-vehicle communication, and broadcasts a packet signal in which control information and the like are stored during the period of the head portion of the selected subframe. The control information includes information related to a period for the base station apparatus to broadcast the packet signal (hereinafter referred to as “road vehicle transmission period”). The terminal device specifies the road and vehicle transmission period based on the control information. The in-vehicle terminal device broadcasts and transmits a packet signal by the CSMA method in a period for performing inter-vehicle communication other than the road-to-vehicle transmission period (hereinafter referred to as “vehicle transmission period”). Thus, since the road-to-vehicle communication and the vehicle-to-vehicle communication are time-division multiplexed, the collision probability of packet signals between them is reduced.

  When the pedestrian carries the terminal device, as described above, the traffic amount may increase and the remaining amount may be lost due to battery driving. Therefore, the communication system according to the present embodiment executes the following process in order to suppress the increase in traffic volume and reduce power consumption. A plurality of portable terminal devices each broadcast a packet signal. When the in-vehicle terminal device receives the packet signal, it selects one of the plurality of portable terminal devices as a “master”. The remaining portable terminal devices correspond to “slave”. A group is formed by one master and the remaining slaves. The in-vehicle terminal device reports a packet signal including information related to the master. The portable terminal device selected as the master continues to notify the packet signal. The portable terminal device not selected as the master, that is, the slave portable terminal device stops the notification of the packet signal.

  FIG. 1 shows a configuration of a communication system 100 according to Embodiment 1 of the present invention. This corresponds to a case where one intersection is viewed from above. The communication system 100 includes a base station device 10, a first vehicle 12a, a second vehicle 12b, a third vehicle 12c, a fourth vehicle 12d, a fifth vehicle 12e, a sixth vehicle 12f, and a seventh vehicle 12g, collectively referred to as a vehicle 12. , The eighth vehicle 12h, and the network 202. In addition, there are a first pedestrian 16a, a second pedestrian 16b, and a third pedestrian 16c, which are collectively referred to as a pedestrian 16. Here, only the first vehicle 12a and the first pedestrian 16a are shown, but the vehicle-mounted terminal device 14 is mounted on each vehicle 12, and the portable terminal device 110 is carried by each pedestrian 16. ing. An area 212 is formed around the base station apparatus 10, and an outside area 214 is formed outside the area 212.

  As shown in the drawing, the road that goes in the horizontal direction of the drawing, that is, the left and right direction, intersects the vertical direction of the drawing, that is, the road that goes in the up and down direction, at the central portion. Here, the upper side of the drawing corresponds to the direction “north”, the left side corresponds to the direction “west”, the lower side corresponds to the direction “south”, and the right side corresponds to the direction “east”. The intersection of the two roads is an “intersection”. The first vehicle 12a and the second vehicle 12b are traveling from left to right, and the third vehicle 12c and the fourth vehicle 12d are traveling from right to left. Further, the fifth vehicle 12e and the sixth vehicle 12f are traveling from the top to the bottom, and the seventh vehicle 12g and the eighth vehicle 12h are traveling from the bottom to the top.

  In the communication system 100, the base station apparatus 10 is fixedly installed at an intersection. The base station device 10 controls communication between terminal devices. The base station device 10 repeatedly generates a frame including a plurality of subframes based on a signal received from a GPS satellite (not shown) and a frame formed by another base station device 10 (not shown). Here, the road vehicle transmission period can be set at the head of each subframe. The base station apparatus 10 selects a subframe in which the road and vehicle transmission period is not set by another base station apparatus 10 from among a plurality of subframes in the frame. The base station apparatus 10 sets a road and vehicle transmission period at the beginning of the selected subframe. The base station apparatus 10 notifies the packet signal in the set road and vehicle transmission period. In the road and vehicle transmission period, a plurality of packet signals may be notified. The packet signal includes, for example, information related to the timing when the road and vehicle transmission period is set and control information related to the frame.

  The in-vehicle terminal device 14 and the portable terminal device 110 generate a frame based on the control information included in the received packet signal, particularly the information about the timing when the road and vehicle transmission period is set and the information about the frame. As a result, the frame generated in each of the in-vehicle terminal device 14 and the portable terminal device 110 is synchronized with the frame generated in the base station device 10. For example, the in-vehicle terminal device 14 and the portable terminal device 110 store information on the presence position in the packet signal. The in-vehicle terminal device 14 and the portable terminal device 110 also store control information in the packet signal. That is, the control information transmitted from the base station device 10 is transferred by the in-vehicle terminal device 14 and the portable terminal device 110.

  Here, the vehicle-mounted terminal device 14 notifies the packet signal by executing CSMA / CA during the vehicle transmission period. On the other hand, the in-vehicle terminal device 14 that cannot receive the packet signal from the base station device 10, that is, the in-vehicle terminal device 14 existing outside the area 214 performs packet transmission by executing CSMA / CA regardless of the frame configuration. Announce the signal. Furthermore, the in-vehicle terminal device 14 notifies the driver of the approach of the vehicle 12 or the pedestrian 16 by receiving a packet signal from another in-vehicle terminal device 14 or the portable terminal device 110.

  Similarly to the in-vehicle terminal device 14, the portable terminal device 110 also notifies the packet signal by executing CSMA / CA during the vehicle transmission period. However, in order to suppress an increase in traffic volume and to realize low power consumption, the notification by the portable terminal device 110 differs from the notification by the in-vehicle terminal device 14 in the following points. Each in-vehicle terminal device 14 broadcasts a packet signal for each frame. On the other hand, the plurality of portable terminal devices 110 form a group, and only the master of them forms a packet signal. Here, the group is a group of portable terminal devices 110 existing in an area close to a certain extent (hereinafter referred to as “grouping area”). The group is set by the in-vehicle terminal device 14.

  FIG. 2 shows the configuration of the base station apparatus 10. The base station apparatus 10 includes an antenna 20, an RF unit 22, a modem unit 24, a processing unit 26, a control unit 28, and a network communication unit 30. Further, the processing unit 26 includes a frame defining unit 32, a selecting unit 34, and a generating unit 36.

  The RF unit 22 receives a packet signal from the in-vehicle terminal device 14, the portable terminal device 110, and another base station device 10 (not shown) by the antenna 20 as reception processing. The RF unit 22 performs frequency conversion on the received radio frequency packet signal to generate a baseband packet signal. Further, the RF unit 22 outputs a baseband packet signal to the modem unit 24. In general, baseband packet signals are formed by in-phase and quadrature components, so two signal lines should be shown, but here only one signal line is shown for clarity. Shall be shown. The RF unit 22 includes an LNA (Low Noise Amplifier), a mixer, an AGC, and an A / D conversion unit.

  As a transmission process, the RF unit 22 performs frequency conversion on the baseband packet signal input from the modem unit 24 to generate a radio frequency packet signal. Further, the RF unit 22 transmits a radio frequency packet signal from the antenna 20 during the road-vehicle transmission period. The RF unit 22 also includes a PA (Power Amplifier), a mixer, and a D / A conversion unit.

  The modem unit 24 demodulates the baseband packet signal from the RF unit 22 as a reception process. Further, the modem unit 24 outputs the demodulated result to the processing unit 26. The modem unit 24 also modulates the data from the processing unit 26 as a transmission process. Further, the modem unit 24 outputs the modulated result to the RF unit 22 as a baseband packet signal. Here, since the communication system 100 corresponds to an OFDM (Orthogonal Frequency Division Multiplexing) modulation scheme, the modem unit 24 also performs FFT (Fast Fourier Transform) as reception processing and IFFT (Inverse Fast Forward) as transmission processing. Also execute.

  The frame defining unit 32 receives a signal from a GPS satellite (not shown), and acquires time information based on the received signal. In addition, since a well-known technique should just be used for acquisition of the information of time, description is abbreviate | omitted here. The frame defining unit 32 generates a plurality of frames based on the time information. For example, the frame defining unit 32 generates ten “100 msec” frames by dividing the “1 sec” period into ten on the basis of the timing indicated by the time information. By repeating such processing, the frame is defined to be repeated. The frame defining unit 32 may detect control information from the demodulation result and generate a frame based on the detected control information. Such processing corresponds to generating a frame synchronized with the timing of the frame formed by another base station apparatus 10.

  3A to 3D show frame formats defined in the communication system 100. FIG. FIG. 3A shows the structure of the frame. The frame is formed of N subframes indicated as the first subframe to the Nth subframe. This can be said that a frame is formed by time-multiplexing subframes that can be used for notification by the in-vehicle terminal device 14 and the portable terminal device 110. For example, when the frame length is 100 msec and N is 8, a subframe having a length of 12.5 msec is defined. N may be other than 8. The description of FIGS. 3B to 3D will be described later and returns to FIG.

  The selection part 34 selects the sub-frame which should set a road and vehicle transmission period among several sub-frames contained in the flame | frame. More specifically, the selection unit 34 receives a frame defined by the frame defining unit 32. In addition, the selection unit 34 receives an instruction regarding a subframe to be selected from the outside, and selects a subframe corresponding to the instruction. A plurality of subframes may be selected. Apart from this, the selection unit 34 may automatically select a subframe. At that time, the selection unit 34 inputs the demodulation results from the other base station device 10, the in-vehicle terminal device 14, and the portable terminal device 110 (not shown) via the RF unit 22 and the modem unit 24. The selection part 34 extracts the demodulation result from the other base station apparatus 10 among the input demodulation results. The selection unit 34 specifies the subframe that has not received the demodulation result by specifying the subframe that has received the demodulation result.

  This corresponds to specifying a subframe in which the road and vehicle transmission period is not set by another base station apparatus 10, that is, an unused subframe. When there are a plurality of unused subframes, the selection unit 34 selects one subframe at random. When there are no unused subframes, that is, when each of a plurality of subframes is used, the selection unit 34 acquires reception power corresponding to the demodulation result, and gives priority to subframes with low reception power. Select

  FIG. 3B shows a configuration of a frame generated by the first base station apparatus 10a. The first base station apparatus 10a sets a road and vehicle transmission period at the beginning of the first subframe. Moreover, the 1st base station apparatus 10a sets a vehicle transmission period following a road and vehicle transmission period in a 1st sub-frame. The vehicle transmission period is a period during which the in-vehicle terminal device 14 and the portable terminal device 110 can notify the packet signal. That is, the first base station apparatus 10a can notify the packet signal in the road and vehicle transmission period which is the head period of the first subframe, and is used for in-vehicle use in the vehicle and vehicle transmission period other than the road and vehicle transmission period in the frame. The terminal device 14 and the portable terminal device 110 are regulated so that the packet signal can be notified. Furthermore, the first base station apparatus 10a sets only the vehicle transmission period from the second subframe to the Nth subframe.

  FIG. 3C shows a configuration of a frame generated by the second base station apparatus 10b. The second base station apparatus 10b sets a road and vehicle transmission period at the beginning of the second subframe. Also, the second base station apparatus 10b sets the vehicle transmission period from the first stage of the road and vehicle transmission period in the second subframe, from the first subframe and the third subframe to the Nth subframe. FIG. 3D shows a configuration of a frame generated by the third base station apparatus 10c. The third base station apparatus 10c sets a road and vehicle transmission period at the beginning of the third subframe. In addition, the third base station apparatus 10c sets the vehicle transmission period from the first stage of the road and vehicle transmission period in the third subframe, the first subframe, the second subframe, and the fourth subframe to the Nth subframe. As described above, the plurality of base station apparatuses 10 select different subframes, and set the road and vehicle transmission period at the head portion of the selected subframe. Returning to FIG. The selection unit 34 outputs the selected subframe number to the generation unit 36.

  The generation unit 36 receives a subframe number from the selection unit 34. The generation unit 36 sets a road and vehicle transmission period in the subframe of the received subframe number, and generates an RSU packet signal to be notified in the road and vehicle transmission period. In the following description, the RSU packet signal may be referred to as a packet signal. FIGS. 4A to 4B show subframe configurations. FIG. 4A shows a subframe in which a road and vehicle transmission period is set. As illustrated, one subframe is configured in the order of a road and vehicle transmission period and a vehicle and vehicle transmission period. FIG. 4B shows the arrangement of packet signals during the road and vehicle transmission period. As illustrated, a plurality of RSU packet signals are arranged in the road and vehicle transmission period. Here, the front and rear packet signals are separated by SIFS (Short Interframe Space). Returning to FIG.

  The network communication unit 30 is connected to a network 202 (not shown). The network communication unit 30 receives, for example, traffic jam information and construction information from the network 202. The packet signal generated in the generation unit 36 is composed of, for example, control information and a data payload. The control information includes a subframe number in which a road and vehicle transmission period is set. The generation unit 36 acquires the traffic jam information and the construction information from the network communication unit 30 and stores them in the data payload, thereby generating the RSU packet signal described above. Note that the location information of the intersection where the base station apparatus 10 is installed (hereinafter referred to as “intersection location information”) may also be included in the data payload. The control unit 28 controls processing of the entire base station device 10.

  This configuration can be realized in terms of hardware by a CPU, memory, or other LSI of any computer, and in terms of software, it can be realized by a program loaded in the memory, but here it is realized by their cooperation. Draw functional blocks. Accordingly, those skilled in the art will understand that these functional blocks can be realized in various forms only by hardware, or by a combination of hardware and software.

  FIG. 5 shows a configuration of the in-vehicle terminal device 14 mounted on the vehicle 12. The in-vehicle terminal device 14 includes an antenna 50, an RF unit 52, a modem unit 54, a processing unit 56, and a control unit 58. The processing unit 56 includes a timing specifying unit 60, a transfer determination unit 62, an acquisition unit 64, a generation unit 66, a notification unit 70, and a grouping execution unit 68. The timing identification unit 60 includes an extraction unit 72 and a carrier sense unit 74. The antenna 50, the RF unit 52, and the modem unit 54 execute the same processing as the antenna 20, the RF unit 22, and the modem unit 24 in FIG. Here, the difference will be mainly described.

  The modem unit 54 and the processing unit 56 receive packet signals from other in-vehicle terminal device 14 (not shown), the portable terminal device 110 (not shown), and the base station device 10 (not shown). As described above, the modem unit 54 and the processing unit 56 receive the packet signal from the base station apparatus 10 during the road and vehicle transmission period. Also, the modem unit 54 and the processing unit 56 receive packet signals from other in-vehicle terminal devices 14 and portable terminal devices 110 during the vehicle transmission period.

  When the demodulation result from the modem unit 54 is a packet signal from the base station apparatus 10 (not shown), the extraction unit 72 specifies the timing of the subframe in which the road and vehicle transmission period is arranged. Specifically, the extraction unit 72 determines whether or not the packet signal is from the base station apparatus 10 based on the control information included in the packet signal. In addition, the extraction unit 72 generates a frame based on the subframe timing and the timing information included in the control information. As a result, the extraction unit 72 generates a frame synchronized with the frame formed in the base station device 10. This corresponds to the operation in the area 212 of FIG. When the notification source of the packet signal is the other in-vehicle terminal device 14 or the portable terminal device 110, the extraction unit 72 omits the synchronized frame generation process.

  Based on the control information, the extraction unit 72 identifies the road and vehicle transmission period being used, and then identifies the remaining vehicle and vehicle transmission period. The extraction unit 72 outputs information on frame and subframe timing and vehicle transmission period to the carrier sense unit 74. On the other hand, when the extraction unit 72 does not receive a packet signal from the base station apparatus 10, that is, when a frame synchronized with the base station apparatus 10 is not generated, the extraction unit 72 selects a timing unrelated to the frame configuration. When the extraction unit 72 selects a timing unrelated to the frame configuration, the extraction unit 72 instructs the carrier sense unit 74 to perform carrier sensing unrelated to the frame configuration. This corresponds to the operation outside the area 214 in FIG.

  The carrier sense unit 74 receives information about the timing of the frames and subframes and the vehicle transmission period from the extraction unit 72. The carrier sense unit 74 determines the transmission timing by starting CSMA / CA within the vehicle transmission period. On the other hand, when the carrier sense unit 74 is instructed to perform carrier sense from the extraction unit 72, the carrier sense unit 74 determines the transmission timing by executing CSMA / CA without considering the frame configuration. The carrier sense unit 74 notifies the modem unit 54 and the RF unit 52 of the determined transmission timing, and broadcasts the packet signal.

  The transfer determination unit 62 controls transfer of control information. The transfer determination unit 62 extracts information to be transferred from the control information. The transfer determination unit 62 generates information to be transferred based on the extracted information. Here, the description of this process is omitted. The transfer determination unit 62 outputs information to be transferred, that is, a part of the control information, to the generation unit 66. The acquisition unit 64 includes a GPS receiver (not shown), a gyroscope, a vehicle speed sensor, and the like, and based on data supplied from these, the location of the vehicle 12 (not shown), that is, the vehicle 12 on which the in-vehicle terminal device 14 is mounted. The traveling direction, the moving speed, etc. (hereinafter collectively referred to as “position information”) are acquired. The existence position is indicated by latitude and longitude. Since a known technique may be used for these acquisitions, description thereof is omitted here. The acquisition unit 64 outputs the position information to the generation unit 66.

  The generation unit 66 receives position information from the acquisition unit 64 and receives a part of control information from the transfer determination unit 62. The generation unit 66 generates a packet signal by storing part of the control information in the control information and storing the position information in the payload. The generated packet signal is broadcast via the modem unit 54 and the RF unit 52. Such notification is made periodically, for example, at a frame period or a subframe period. The notification unit 70 acquires a packet signal from the base station device 10 (not shown) during the road-to-vehicle transmission period, and packets from other in-vehicle terminal devices 14 and portable terminal devices 110 (not shown) during the vehicle-to-vehicle transmission period. Get the signal. As a process for the acquired packet signal, the notification unit 70 notifies the driver of the approach of another vehicle 12 or a pedestrian 16 (not shown) via a monitor or speaker according to the content of the data stored in the packet signal. To do. The grouping execution unit 68 executes processing for forming a group for the plurality of portable terminal devices 110. The processing of the grouping execution unit 68 will be described later. The control unit 58 controls the operation of the in-vehicle terminal device 14.

  FIG. 6 shows the configuration of the grouping execution unit 68. The grouping execution unit 68 includes an information extraction unit 80, an area setting unit 82, a storage unit 84, a selection unit 86, and an output unit 88. The information extraction unit 80 receives each of the packet signals broadcast from the plurality of portable terminal devices 110 via the RF unit 52, the modulation / demodulation unit 54, and the like in FIG. 5, and extracts data from the packet signals. FIGS. 7A and 7B show data formats used in the communication system 100. FIG. FIG. 7A shows the format of data acquired by the information extraction unit 80. Here, the portable terminal device ID and the position information are included. The portable terminal device ID is information for identifying the portable terminal device 110 that is a packet signal notification source, and the position information is a position where the portable terminal device 110 is present. Note that information other than these may be included in the data. FIG. 7B will be described later, and the processing returns to FIG.

  The storage unit 84 stores map information as electronic data. In addition, when the vehicle-mounted terminal device 14 (not shown) is connected to the car navigation system, the map information may be shared with the car navigation system. The storage unit 84 also stores information on grouping areas for forming groups. The grouping area is defined as 10 m square, for example, and is defined in the vicinity of the intersection or in a predetermined area. Therefore, the map information is associated with a plurality of grouping areas. The grouping area information is stored as latitude / longitude information.

  The area setting unit 82 receives position information from the acquisition unit 64 (not shown), and extracts grouping area information from the storage unit 84 based on the position information. For example, the area setting unit 82 selects and acquires information on grouping areas existing in the traveling direction. The extracted grouping area information becomes a grouping area candidate from which a group is to be formed. The area setting unit 82 outputs the extracted grouping area information to the selection unit 86.

  The selection unit 86 receives the portable terminal device ID and the position information from the information extraction unit 80 and also receives the grouping area information from the area setting unit 82. The selection unit 86 confirms whether the position information is included in the grouping area. When position information from only one portable terminal device 110 is included in the grouping area over a predetermined period, the selection unit 86 determines that a group has already been formed. The selection unit 86 interrupts the subsequent processing and newly receives grouping area information from the area setting unit 82. On the other hand, when position information from a plurality of portable terminal devices 110 is included in the grouping area over a predetermined period, the selection unit 86 selects one of the plurality of portable terminal devices 110. Here, for example, the portable terminal device 110 is selected at random. The selected portable terminal device 110 corresponds to the master in the group.

  The output unit 88 includes the selection result of the selection unit 86 in the data. FIG. 7B shows a format of data output from the output unit 88. Here, the area position information and the master ID are included. The area position information is the position information of the grouping area where the group is to be formed, and is the information of the grouping area extracted by the area setting unit 82. The master ID is information for identifying the portable terminal device 110 selected by the selection unit 86. These are also called group information. Returning to FIG. Since the output unit 88 outputs the data to the generation unit 66 in FIG. 5, the packet signal including the information shown in FIG. 7B is notified from the in-vehicle terminal device 14.

  The portable terminal device 110 selected as the master, that is, the portable terminal device 110 selected by the selection unit 86 continues to notify the packet signal. On the other hand, the portable terminal device 110 other than the master, that is, the slave portable terminal device 110 stops reporting the packet signal. Thus, only one of the plurality of portable terminal devices 110 included in the group broadcasts the packet signal. Groups continue to be formed until the master leaves the grouping area.

  Since the master is selected at random, the plurality of portable terminal devices 110 can become masters with almost equal probability. Therefore, occurrence of a situation in which only a specific portable terminal device 110 becomes a master is suppressed. This corresponds to the suppression of the occurrence of the portable terminal device 110 in which the remaining amount of the battery is extremely reduced. As a result, selecting at random can be said to select the portable terminal device 110 that is likely to have a longer duration of packet signal notification. Furthermore, the possibility that the duration of the packet signal notification will be long is high that the period during which the packet signal notification is continued is likely to be long. As described above, when another in-vehicle terminal device 14 enters a grouping area in which a group has already been formed, the other in-vehicle terminal device 14 does not form a group.

  When a new portable terminal device 110 enters a grouping area where a group is formed, the new portable terminal device 110 broadcasts a packet signal. As a result, the information extraction unit 80 also receives a packet signal notified from the new portable terminal device 110. The selection unit 86 selects either the new portable terminal device 110 or the portable terminal device 110 that has already been selected as the master based on the information included in the packet signal from the new portable terminal device 110. Select again. Again, a random selection is made. The output unit 88 includes the result selected again by the selection unit 86 in the data and outputs the data to the generation unit 66. As a result, the master may or may not change. When a new portable terminal device 110 enters the grouping area where the group is formed, the new portable terminal device 110 may operate as a slave without notifying the packet signal.

  FIG. 8 shows a configuration of the portable terminal device 110 carried by the pedestrian 16. The portable terminal device 110 includes an antenna 120, an RF unit 122, a modem unit 124, a processing unit 126, and a control unit 128. The processing unit 126 includes a timing control unit 130, a generation unit 132, a transfer determination unit 134, an acquisition unit 136, and a grouping execution unit 138. The timing control unit 130 includes an extraction unit 140 and a carrier sense unit 142. The antenna 120, the RF unit 122, the modulation / demodulation unit 124, the extraction unit 140, the carrier sense unit 142, the transfer determination unit 134, the acquisition unit 136, and the generation unit 132 are the antenna 50, the RF unit 52, the modulation / demodulation unit 54, and the extraction unit 132 of FIG. 72, the carrier sense unit 74, the transfer determination unit 62, the acquisition unit 64, and the generation unit 66. Therefore, here, the difference will be mainly described.

  The grouping execution unit 138 executes processing corresponding to the group set by the in-vehicle terminal device 14 (not shown). When the group is not set, the generation unit 132, the modem unit 124, and the RF unit 122 broadcast the packet signal. Since this notification is periodically made in the same manner as the in-vehicle terminal device 14, it is also called normal operation. The grouping execution unit 138 acquires group information from the in-vehicle terminal device 14 via the modem unit 124. The grouping execution unit 138 extracts area position information from the group information. The area position information can be said to be information related to the grouping area in which the portable terminal device 110 selected as the master in the in-vehicle terminal device 14 becomes effective. In addition, the grouping execution unit 138 acquires position information from the acquisition unit 136. If the position information is not included in the area position information, the grouping execution unit 138 stops the process. On the other hand, if the position information is included in the area position information, the grouping execution unit 138 extracts the master ID from the group information.

  If the master ID is the own device, the grouping execution unit 138 executes an operation as a master. That is, the grouping execution unit 138 continues to notify the packet signal as in the normal operation. If the master ID is another portable terminal device 110, the grouping execution unit 138 executes an operation as a slave. At that time, the grouping execution unit 138 stops broadcasting the packet signal.

  When operating as a slave, the grouping execution unit 138 monitors the position information included in the packet signal notified from the master portable terminal device 110 and the position information from the acquisition unit 136. When the position information of the master portable terminal device 110 goes out of the grouping area, the grouping execution unit 138 switches from the slave to the normal operation. That is, the notification of the packet signal is resumed. This is because the master no longer exists in the group, which corresponds to the disappearance of the group. Also, when the position information from the acquisition unit 136 goes out of the grouping area, the grouping execution unit 138 switches from the master to the normal operation. This is because the portable terminal device 110 has left the group.

  The operation of the communication system 100 configured as above will be described. FIG. 9 is a sequence diagram illustrating a group setting procedure by the communication system 100. The first portable terminal device 110a notifies the packet signal (S10), and the second portable terminal device 110b also notifies the packet signal (S12). The in-vehicle terminal device 14 selects the first portable terminal device 110a as a master based on the received packet signal (S14). The in-vehicle terminal device 14 notifies the packet signal storing the group information (S16, S18). The first portable terminal device 110a is set as a master based on the group information (S20), and the second portable terminal device 110b is set as a slave based on the group information (S22). The first portable terminal device 110a continues to notify the packet signal (S24).

  FIG. 10 is a flowchart showing a group setting procedure by the in-vehicle terminal device 14. If the information extraction unit 80 receives packet signals from a plurality of portable terminal devices 110 in the grouping area (Y in S30), the selection unit 86 selects one portable terminal device 110 as a master ( S32). The output unit 88 notifies group information (S34). If the information extraction unit 80 has not received a packet signal from the plurality of portable terminal devices 110 in the grouping area (N in S30), the process ends.

  FIG. 11 is a flowchart showing a group setting procedure by the portable terminal device 110. The modem unit 124, the RF unit 122, etc. broadcast the packet signal (S40). The RF unit 122, the modem unit 124, etc. receive the packet signal (S42). If it is instructed to become a master in the group information included in the received packet signal (Y in S44), the grouping execution unit 138 continues to notify the packet signal (S46). If it is not instructed to become a master in the group information included in the received packet signal (N in S44), the grouping execution unit 138 stops the notification of the packet signal (S48).

  FIG. 12 is a sequence diagram illustrating a procedure for setting another group by the communication system 100. The first portable terminal device 110a notifies the packet signal (S60), and the second portable terminal device 110b also notifies the packet signal (S62). The in-vehicle terminal device 14 selects the first portable terminal device 110a as a master based on the received packet signal (S64). The in-vehicle terminal device 14 notifies the packet signal storing the group information (S66, S68). The first portable terminal device 110a rejects the master setting in the group information (S70), and the second portable terminal device 110b is set as a slave based on the group information (S72).

  The 1st portable terminal device 110a alert | reports the packet signal containing the effect which refuses the setting of a master (S74, S76). The in-vehicle terminal device 14 selects the second portable terminal device 110b as another master based on the received packet signal (S78). The second portable terminal device 110b is set to normal operation (S80). The in-vehicle terminal device 14 notifies the packet signal in which the group information is stored (S82, S84). The first portable terminal device 110a is set as a slave based on group information (S86), and the second portable terminal device 110b is set as a master based on group information (S88).

  FIG. 13 is a flowchart showing a return procedure from the slave by the portable terminal device 110. The grouping execution unit 138 operates as a slave (S100). If the master portable terminal device 110 leaves the grouping area (Y in S102), the grouping execution unit 138 changes to the normal operation (S106). Even if the master portable terminal device 110 does not exit the grouping area (N in S102), if the portable terminal device 110 exits the grouping area (Y in S104), the grouping execution unit 138 changes to the normal operation. (S106). If the portable terminal device 110 does not exit the grouping area (N in S104), the process ends.

  FIG. 14 is a sequence diagram illustrating a procedure for setting another group by the communication system 100. This is processing subsequent to FIG. The first portable terminal device 110a is set as a master (S110), and the third portable terminal device 110c enters the grouping area (S112). The first portable terminal device 110a notifies the packet signal (S114), and the third portable terminal device 110c also notifies the packet signal (S116). The in-vehicle terminal device 14 selects the first portable terminal device 110a as the master again based on the received packet signal (S118). The in-vehicle terminal device 14 notifies the packet signal in which the group information is stored (S120, S122). The first portable terminal device 110a is set as a master based on the group information (S124), and the third portable terminal device 110c is set as a slave based on the group information (S126). The first portable terminal device 110a continues to notify the packet signal (S128).

  FIG. 15 is a flowchart showing a setting procedure of still another group by the in-vehicle terminal device 14. When the information extraction unit 80 receives packet signals from the master portable terminal device 110 and the new portable terminal device 110 (Y in S140), the selection unit 86 sets one portable terminal device 110 as a master. Select (S142). The output unit 88 notifies group information (S144). If the information extraction unit 80 does not receive packet signals from the master portable terminal device 110 and the new portable terminal device 110 (N in S140), the process is terminated.

  According to the embodiment of the present invention, since a master in a group is selected and designated, a plurality of portable terminal devices can be classified into a master and a slave. Also, since only the master continues to report the packet signal and the slave stops reporting the packet signal, an increase in traffic volume and an increase in power consumption can be suppressed. Moreover, since a group is formed, broadcast transmission can be executed efficiently. When a new portable terminal device enters the grouping area, a new master is selected between the previous master and the new portable terminal device, so that the group can be continued. Further, as long as the master exists in the group, the group is continued, so that the group forming process can be made unnecessary. Further, when there is no more master in the group, the normal operation is resumed, so that position information can be notified. In addition, when the user leaves the group, the normal operation is resumed, so that position information can be notified. Moreover, since the master is selected at random, the probability of being selected as the master can be equalized. In addition, since the masters are selected equally, battery consumption is suppressed and the period of operation as the master can be extended.

(Example 2)
Next, Example 2 will be described. Similarly to the first embodiment, the second embodiment also relates to the formation of a group of a plurality of portable terminal devices according to instructions from the in-vehicle terminal device. In the first embodiment, in order to clarify the explanation, the portable terminal device receives group information from one in-vehicle terminal device. On the other hand, in Example 2, the case where the portable terminal device has received group information from a plurality of in-vehicle terminal devices is assumed. Here, it is assumed that the group information targets the same grouping area. Generally, since processing in each in-vehicle terminal device is performed independently, a plurality of in-vehicle terminal devices may select different masters for the same grouping area. Therefore, the second embodiment aims to form a group together with other portable terminal devices and efficiently perform broadcast transmission even when receiving group information independent from a plurality of in-vehicle terminal devices. To do.

  To cope with this, the portable terminal device according to the second embodiment follows the previously received group information if the timing difference between the two pieces of group information is within a threshold value. Therefore, group information received later is ignored. On the other hand, if the timing difference between the two pieces of group information received is within the threshold value, the portable terminal device follows the group information received later. The communication system 100, the base station device 10, the in-vehicle terminal device 14, and the portable terminal device 110 according to the second embodiment are the same types as those in FIGS. 1, 2, 5, and 8. Here, the difference will be mainly described.

  The grouping execution unit 138 of FIG. 8 receives the group information from another in-vehicle terminal device 14 before receiving a certain period of time after receiving the group information from the in-vehicle terminal device 14. Operates according to group information. The fixed period is set to 1 second, for example. In addition, when the grouping execution unit 138 receives group information from another in-vehicle terminal device 14 after a certain period of time has elapsed after receiving the group information from the in-vehicle terminal device 14, another group of in-vehicle terminal devices 14 operates according to the group information from 14. Even if the group information is received, the control as described above is not performed unless the in-vehicle terminal device 14 belongs to the group information. That is, even if group information is received from the in-vehicle terminal device 14, if the group position information is not included in the area position information, the grouping execution unit 138 According to the group information received from the in-vehicle terminal device 14.

  FIG. 16 shows an outline of grouping area formation in the communication system 100 according to the second embodiment of the present invention. This corresponds to the case where one intersection is viewed from above, as in FIG. 1, but in order to simplify the drawing, the display of the vehicle 12 and the pedestrian 16 is omitted, and the in-vehicle terminal device 14, the mobile phone Only the terminal device 110 is shown. The second in-vehicle terminal device 14b is going to form the first grouping area 300a, and the first in-vehicle terminal device 14a is going to form the second grouping area 300b. Therefore, the first portable terminal device 110a and the second portable terminal device 110b are objects of grouping by the second in-vehicle terminal device 14b, and the second portable terminal device 110b and the third portable terminal device 110c are the first ones. 1 It is the object of the group by the in-vehicle terminal device 14a. Here, it is assumed that some of the plurality of grouping areas 300 overlap, but they do not have to overlap.

  FIG. 17 is a sequence diagram illustrating a first pattern of a group setting procedure in the communication system 100. This is because the second in-vehicle terminal device 14b designates the first portable terminal device 110a as the master within one second after the first in-vehicle terminal device 14a designates the third portable terminal device 110c as the master. This is the case. The first in-vehicle terminal device 14a notifies a packet signal in which group information is stored (S150, S152, S154). Since the first portable terminal device 110a is outside the grouping area, the normal operation continues (S156), the second portable terminal device 110b is set as a slave (S158), and the third portable terminal device 110c is the master. (S160). Within 1 second, the second in-vehicle terminal device 14b notifies the packet signal storing the group information (S162, S164, S166). The first portable terminal device 110a is set as a master (S168), the second portable terminal device 110b is ignored (S170), and the third portable terminal device 110c is ignored (S172).

  FIG. 18 is a sequence diagram illustrating a second pattern of the group setting procedure in the communication system 100. This is because the second in-vehicle terminal device 14b designates the first portable terminal device 110a as the master one second after the first in-vehicle terminal device 14a designates the third portable terminal device 110c as the master. This is the case. The first in-vehicle terminal device 14a notifies a packet signal in which group information is stored (S180, S182, S184). Since the first portable terminal device 110a is outside the grouping area, the normal operation continues (S186), the second portable terminal device 110b is set as a slave (S188), and the third portable terminal device 110c is the master. (S190). After 1 second has elapsed, the second in-vehicle terminal device 14b reports the packet signal in which the group information is stored (S192, S194, S196). The first portable terminal device 110a is set as a master (S198), the second portable terminal device 110b is set as a slave (S200), and the third portable terminal device 110c is ignored (S202).

  FIG. 19 is a sequence diagram illustrating a third pattern of the group setting procedure in the communication system 100. This is because the first in-vehicle terminal device 14a designates the second portable terminal device 110b as the master, and within one second, the second in-vehicle terminal device 14b designates the first portable terminal device 110a as the master. This is the case. The first in-vehicle terminal device 14a notifies a packet signal storing group information (S210, S212, S214). Since the first portable terminal device 110a is outside the grouping area, the normal operation continues (S216), the second portable terminal device 110b is set as the master (S218), and the third portable terminal device 110c is the slave. (S220). Within one second, the second in-vehicle terminal device 14b notifies the packet signal storing the group information (S222, S224, S226). The first portable terminal device 110a is set as a master (S228), the second portable terminal device 110b is ignored (S230), and the third portable terminal device 110c is ignored (S232).

  FIG. 20 is a sequence diagram illustrating a fourth pattern of the group setting procedure in the communication system 100. This is because the second in-vehicle terminal device 14b designates the first portable terminal device 110a as the master one second after the first in-vehicle terminal device 14a designates the second portable terminal device 110b as the master. This is the case. The first in-vehicle terminal device 14a notifies a packet signal in which group information is stored (S240, S242, S244). Since the first portable terminal device 110a is outside the grouping area, the normal operation continues (S246), the second portable terminal device 110b is set as the master (S248), and the third portable terminal device 110c is the slave. (S250). After 1 second has elapsed, the second in-vehicle terminal device 14b notifies the packet signal in which the group information is stored (S252, S254, S256). The first portable terminal device 110a is set as a master (S258), the second portable terminal device 110b is set as a slave (S260), and the third portable terminal device 110c returns to normal operation (S262). .

  FIG. 21 is a sequence diagram illustrating a fifth pattern of the group setting procedure in the communication system 100. This is because the second in-vehicle terminal device 14b designates the second portable terminal device 110b as the master within one second after the first in-vehicle terminal device 14a designates the third portable terminal device 110c as the master. This is the case. The first in-vehicle terminal device 14a notifies the packet signal storing the group information (S270, S272, S274). Since the first portable terminal device 110a is outside the grouping area, the normal operation continues (S276), the second portable terminal device 110b is set as a slave (S278), and the third portable terminal device 110c is the master. (S280). Within one second, the second in-vehicle terminal device 14b notifies the packet signal in which the group information is stored (S282, S284, S286). The first portable terminal device 110a is set as a slave, but since there is no master, it returns to normal operation (S288), the second portable terminal device 110b ignores (S290), and the third portable terminal The device 110c ignores (S292).

  FIG. 22 is a sequence diagram illustrating a sixth pattern of the group setting procedure in the communication system 100. This is because the second in-vehicle terminal device 14b designates the second portable terminal device 110b as the master one second after the first in-vehicle terminal device 14a designates the third portable terminal device 110c as the master. This is the case. The first in-vehicle terminal device 14a notifies a packet signal in which group information is stored (S300, S302, S304). Since the first portable terminal device 110a is outside the grouping area, the normal operation continues (S306), the second portable terminal device 110b is set as a slave (S308), and the third portable terminal device 110c is the master. (S310). After 1 second has elapsed, the second in-vehicle terminal device 14b notifies the packet signal storing the group information (S312, S314, S316). The first portable terminal device 110a is set as a slave (S318), the second portable terminal device 110b is set as a master (S320), and the third portable terminal device 110c ignores (S322).

  FIG. 23 is a sequence diagram illustrating a seventh pattern of the group setting procedure in the communication system 100. This is because the first in-vehicle terminal device 14a designates the second portable terminal device 110b as the master, and within one second, the second in-vehicle terminal device 14b designates the second portable terminal device 110b as the master. This is the case. The first in-vehicle terminal device 14a notifies the packet signal storing the group information (S330, S332, S334). Since the first portable terminal device 110a is outside the grouping area, the normal operation continues (S336), the second portable terminal device 110b is set as the master (S338), and the third portable terminal device 110c is the slave. (S340). Within one second, the second in-vehicle terminal device 14b notifies the packet signal in which the group information is stored (S342, S344, S346). The first portable terminal device 110a is set as a slave (S348), the second portable terminal device 110b is set as a master (S350), and the third portable terminal device 110c ignores (S352).

  FIG. 24 is a sequence diagram illustrating an eighth pattern of the group setting procedure in the communication system 100. This is because the first in-vehicle terminal device 14a designates the second portable terminal device 110b as the master, and after one second has elapsed, the second in-vehicle terminal device 14b designates the second portable terminal device 110b as the master. This is the case. The first in-vehicle terminal device 14a notifies the packet signal storing the group information (S360, S362, S364). Since the first portable terminal device 110a is outside the grouping area, the normal operation continues (S366), the second portable terminal device 110b is set as the master (S368), and the third portable terminal device 110c is the slave. (S370). Within one second, the second in-vehicle terminal device 14b notifies the packet signal in which the group information is stored (S372, S374, S376). The first portable terminal device 110a is set as a slave (S378), the second portable terminal device 110b is set as a master (S380), and the third portable terminal device 110c ignores (S382).

  According to the embodiment of the present invention, even if group information is received from another in-vehicle terminal device before the lapse of a certain period after the group information is received, the latter group information is discarded. Can be stabilized. In addition, when group information is received from another in-vehicle terminal device after a certain period of time has elapsed since receiving group information, the latest group information can be reflected because it follows the latter group information.

(Example 3)
Next, Example 3 will be described. The third embodiment also relates to the formation of a group of a plurality of portable terminal devices in accordance with an instruction from the in-vehicle terminal device as before. Until now, the in-vehicle terminal device has randomly selected one portable terminal device as a master. However, in order to achieve a desired purpose, a portable terminal device suitable for the purpose may be selected. For this reason, the third embodiment aims to form a group by selecting a portable terminal device suitable for various situations as a master to efficiently execute broadcast transmission. In the third embodiment, various criteria for selecting one portable terminal device will be described. The communication system 100, the base station device 10, the in-vehicle terminal device 14, and the portable terminal device 110 according to the third embodiment are the same types as those in FIGS. 1, 2, 5, and 8. Here, the difference will be mainly described.

With the random selection described so far as the first selection criterion, the second selection criterion to the seventh selection criterion will be described below.
1. Second Selection Criteria In the second selection criterion, the portable terminal device 110 that is likely to have a long duration of packet signal notification is selected as in the first selection criterion. The portable terminal device 110 stores information on the remaining battery level in the packet signal data. Therefore, the information extraction unit 80 extracts information related to the remaining battery level in addition to the information described so far. The selection unit 86 selects the portable terminal device 110 with a large remaining battery level as a master. Even if the portable terminal device 110 having a large remaining battery level becomes a master and continues to notify the packet signal, the possibility of running out of the battery is low. Therefore, selecting such a portable terminal device 110 can be said to select the portable terminal device 110 that is likely to have a longer duration of packet signal notification.

2. Third Selection Criteria In the third selection criteria to the sixth selection criteria, unlike the past, the portable terminal device 110 present at a high risk position is selected. Since the packet signal from the portable terminal device 110 is continuously received by selecting the portable terminal device 110 present at a high risk position as a master, it becomes possible to be careful. In the third selection criterion, the information extraction unit 80 derives the moving speed of the portable terminal device 110 by continuously receiving packet signals from the portable terminal device 110. The time change of the position information is used for deriving the moving speed. The selection unit 86 selects the portable terminal device 110 having a high moving speed as a master. This is because the higher the moving speed, the higher the risk.

3. The fourth selection criterion selection unit 86 receives position information from the acquisition unit 64. This position information can be said to be position information of the vehicle 12 on which the in-vehicle terminal device 14 is mounted. In addition, the selection unit 86 receives position information of each portable terminal device 110 from the information extraction unit 80. The selection unit 86 selects the portable terminal device 110 present near the vehicle 12 as a master based on the position information. This is because the closer to the vehicle 12, the higher the risk.

4). The fifth selection criterion selection unit 86 receives roadway position information stored in the storage unit 84. In addition, the selection unit 86 receives position information of each portable terminal device 110 from the information extraction unit 80. The selection unit 86 selects the portable terminal device 110 existing near the roadway as a master based on the position information. This is because the closer to the roadway, the higher the risk.

5. The sixth selection criterion selection unit 86 receives position information from the acquisition unit 64. As described above, this position information can be said to be position information of the vehicle 12 on which the in-vehicle terminal device 14 is mounted. The selection unit 86 predicts the traveling direction of the vehicle 12 based on the history of position information. Since a well-known technique should just be used for the said prediction, description is abbreviate | omitted here. In addition, the information extraction unit 80 continuously receives the packet signal from the portable terminal device 110, thereby acquiring the history of the position information of the portable terminal device 110. Moreover, the information extraction part 80 estimates the advancing direction of the pedestrian 16 who carried the portable terminal device 110 based on the history of position information. The selection unit 86 selects, as a master, the portable terminal device 110 that comes toward the vehicle 12 based on the traveling direction of the vehicle 12 and the traveling direction of the pedestrian 16. This is because the danger increases as the vehicle 12 is approached.

6). Seventh Selection Criteria In the seventh selection criterion, the premise is different from the previous one. As described above, the portable terminal device 110 is equipped with a reception function and a transmission function. Furthermore, a terminal device (hereinafter referred to as “transmission-only device”) that has only a transmission function and no reception function is also defined here. The transmission-only device is carried by the pedestrian 16, for example. The transmission-dedicated device broadcasts the packet signal without performing carrier sense. Note that only the carrier sense function may be installed in the transmission-dedicated device without having the packet signal reception function. Here, in the packet signal notified from the portable terminal device 110 or the transmission dedicated device, information (hereinafter referred to as “type information”) indicating whether it is the portable terminal device 110 or the transmission dedicated device. ) Is included. The information extraction unit 80 extracts type information from the received packet signal. The selection unit 86 selects a transmission-only device by referring to the type information when selecting the master from the portable terminal device 110 and the transmission-only device. This is because the transmission-dedicated device does not have a reception function and cannot operate as a slave.

  According to the embodiment of the present invention, since the portable terminal device that is likely to have a long operation period as the master is selected as the master, the lifetime of the group can be lengthened. In addition, since the group continues for a long period, broadcast transmission can be executed efficiently. Moreover, since the portable terminal device with much remaining battery capacity is selected as the master, the operation period as the master can be lengthened. Moreover, since the portable terminal device which exists in a highly dangerous position is selected as a master, the packet signal from a highly dangerous portable terminal device can be received. Thereby, the risk of collision can be reduced. Moreover, since the portable terminal device with a high moving speed is selected as a master, the movement of the portable terminal device with a high risk can be monitored. Moreover, since the portable terminal device which exists near the vehicle is selected, the presence near the vehicle can be monitored. Moreover, since the portable terminal device which comes toward the vehicle is selected, a collision can be easily avoided. In addition, since a transmission-dedicated device that has a transmission function and no reception function is selected, the power consumption of the portable terminal device can be reduced.

Example 4
Next, Example 4 will be described. The fourth embodiment also relates to the formation of a group of a plurality of portable terminal devices in accordance with an instruction from the in-vehicle terminal device as before. So far, the portable terminal device belongs to any group. If it is strictly defined that it belongs to one group, it is necessary to determine the boundary between adjacent grouping areas. When communication is performed only to determine the boundary of the grouping area, power consumption increases and frequency resources are wasted. In addition, depending on the boundary determination method, additional operations are required, which increases the circuit scale. Further, because the boundary determination method causes another grouping area to be entered, there is a risk that danger may be missed.

  Therefore, the purpose of the fourth embodiment is to form a group in an appropriate grouping area and efficiently execute broadcast transmission. In order to cope with this, when grouping areas of groups formed by a plurality of in-vehicle terminal devices overlap each other, and portable terminal devices exist in a plurality of grouping areas, the portable terminal devices are divided into a plurality of groups. Belongs. The communication system 100, the base station device 10, the in-vehicle terminal device 14, and the portable terminal device 110 according to the fourth embodiment are the same types as those in FIGS. Here, the difference will be mainly described.

  FIG. 25 shows an outline of grouping area formation in the communication system 100 according to the fourth embodiment of the present invention. This corresponds to the case where one intersection is viewed from above, as in FIG. 1, but in order to simplify the drawing, the display of the vehicle 12 and the pedestrian 16 is omitted, and the in-vehicle terminal device 14, the mobile phone Only the terminal device 110 is shown. The first in-vehicle terminal device 14a is going to form the first grouping area 300a, and the second in-vehicle terminal device 14b is going to form the second grouping area 300b. Therefore, the first portable terminal device 110a and the fourth portable terminal device 110d belong to a group in the first grouping area 300a. Further, the first portable terminal device 110a, the second portable terminal device 110b, and the third portable terminal device 110c belong to a group in the second grouping area 300b. Thus, the 1st portable terminal device 110a belongs to two groups.

  In the first portable terminal device 110a in FIG. 25, the grouping execution unit 138 receives group information from the first in-vehicle terminal device 14a. This group information is information relating to a group formed by a plurality of portable terminal devices 110 existing in the first grouping area 300a. The grouping execution unit 138 executes an operation as a master or an operation as a slave in the first grouping area 300a according to the group information.

  Following this, the grouping execution unit 138 receives group information from the second in-vehicle terminal device 14b. This group information is information relating to a group formed by a plurality of portable terminal devices 110 existing in the second grouping area 300b partially overlapping with the first grouping area 300a. The grouping execution unit 138 executes the operation as the master or the operation as the slave in the second grouping area 300b in accordance with the group information already received and in accordance with the newly received group information. Furthermore, the same operation is repeated when receiving group information from another in-vehicle terminal device 14.

  FIG. 26 is a flowchart showing a group setting procedure by the portable terminal device 110. The grouping execution unit 138 receives the packet signal from the first in-vehicle terminal device 14a (S390). When existing in the grouping area indicated by the group information (Y in S392), the grouping execution unit 138 follows the group information from the first in-vehicle terminal device 14a (S394). If it does not exist in the grouping area indicated in the group information (N in S392), step 394 is skipped.

  The grouping execution unit 138 receives the packet signal from the second in-vehicle terminal device 14b (S396). When existing in the grouping area indicated by the group information (Y in S398), the grouping execution unit 138 follows the group information from the second in-vehicle terminal device 14b (S400). If it does not exist in the grouping area indicated in the group information (N in S398), step 400 is skipped.

  Up to this point, the processing when one portable terminal device 110 receives group information from a plurality of different portable terminal devices 110 has been described. Next, processing when one portable terminal device 110 receives different group information from one portable terminal device 110 will be described.

  FIGS. 27A and 27B show an outline of another grouping area formation in the communication system 100 according to the fourth embodiment of the present invention. These correspond to the case where one intersection is viewed from above, as in FIG. 1, but in order to simplify the drawing, the display of the vehicle 12 and the pedestrian 16 is omitted, the in-vehicle terminal device 14, the mobile phone Only the terminal device 110 is shown. Fig.27 (a) is a case where the signal of the direction which the vehicle 12 carrying the 1st vehicle-mounted terminal device 14a advances is blue, FIG.27 (b) mounted the 1st vehicle-mounted terminal device 14a. This is a case where the signal in the direction in which the vehicle 12 travels is red. Here, the base station apparatus 10 (not shown) installed at the intersection broadcasts a packet signal in which information related to the light color of the traffic light is stored, and the first in-vehicle terminal apparatus 14a receives the packet signal. To obtain the light color information.

  The area setting unit 82 of FIG. 5 sets the first grouping area 300a and the second grouping area 300b for each intersection in the map information stored in the storage unit 84. Here, the first grouping area 300a is an area that should be set in the traveling direction, and the second grouping area 300b is an area that should be set in the direction of turning left or right. The selection part 86 produces | generates the 1st group information regarding the group formed by the some portable terminal device 110 which exists in the 1st grouping area 300a.

  The selection unit 86 also generates second group information related to a group formed by the plurality of portable terminal devices 110 existing in the second grouping area 300b. The output unit 88 outputs the first group information when the lamp color information is blue, and outputs the second group information when the lamp color information is red. That is, the first group information and the second group information are notified at different timings. As described above, in the first group information and the second group information, only one of the plurality of portable terminal devices 110 forming each group is allowed to notify the packet signal.

  The grouping execution unit 138 in FIG. 8 receives the second group information after receiving the first group information from the in-vehicle terminal device 14. The grouping execution unit 138 controls the RF unit 122, the modem unit 124, and the like so as to follow the second group information instead of the already received first group information. That is, when the group information from one grouping execution unit 138 is updated, the grouping execution unit 138 controls to follow the updated group information.

  FIG. 28 is a flowchart showing a group setting procedure by the portable terminal device 110. If the lamp color is blue (Y in S410), the output unit 88 stores the group information for blue in the packet signal (S412). If the lamp color is not blue (N in S410), the output unit 88 stores the group information for red in the packet signal (S414).

  According to the embodiment of the present invention, since group information from a plurality of in-vehicle terminal devices is reflected, it can belong to a plurality of groups. Further, since it belongs to a plurality of groups, broadcast transmission can be executed efficiently. Moreover, since it belongs to a plurality of groups, communication only for determining the boundary of the grouping area becomes unnecessary, so that power consumption can be suppressed and frequency resources can be used effectively. Moreover, since it belongs to a plurality of groups, danger can be notified. Further, since the grouping area is changed according to the light color of the traffic light, a group corresponding to the light color can be set.

(Example 5)
Next, Example 5 will be described. The fifth embodiment also relates to the formation of a group of a plurality of portable terminal devices in accordance with an instruction from the in-vehicle terminal device as before. Until now, it was assumed that the size of the grouping area was almost constant. However, traffic volume and danger vary from place to place. In a place where the probability of occurrence of a collision accident is high, it is desirable to notify the packet signal by as many portable terminal devices as possible in order to prevent the packet signal from reaching the in-vehicle terminal device. On the other hand, in places where the occurrence probability of collision accidents is low, it is not necessary to be notified of packet signals by many portable terminal devices. The number of portable terminal devices that should be notified of packet signals depends on the number of portable terminal devices included in the group, which also depends on the size of the grouping area.

  Therefore, in order to reduce the probability of occurrence of a collision accident, the size of the grouping area should be adjusted according to the location. The fifth embodiment aims to form a group so as to adjust the size of the grouping area according to the location, and to efficiently perform broadcast transmission. In the fifth embodiment, the size of the grouping area is changed according to the presence / absence of a traffic light, the number of pedestrians carrying the portable terminal device, the distance from the roadway, and a predetermined area. The communication system 100, the base station apparatus 10, the in-vehicle terminal apparatus 14, and the portable terminal apparatus 110 according to the fifth embodiment are the same types as those in FIG. 1, FIG. 2, FIG. 5, and FIG. Here, the difference will be mainly described.

1. The adjustment area setting unit 82 according to the traffic light extracts the grouping area information from the storage unit 84 as described above, and sets the grouping area. Here, the size of the grouping area is changed according to the degree of risk. More specifically, the size of the grouping area is changed depending on whether a traffic light is installed at the intersection. For example, a grouping area is not set at an intersection where no traffic lights are installed. That is, each portable terminal device 110 performs a normal operation and notifies a packet signal. This is equivalent to minimizing the grouping area. In addition, a grouping area is set at an intersection where a traffic light is installed at the intersection. As in the fourth embodiment, the position of the grouping area is changed according to the signal color.

  FIGS. 29A to 29C show an outline of grouping area formation in the communication system 100 according to the fifth embodiment of the present invention. These correspond to the case where one intersection is viewed from above, as in FIG. 1, but in order to simplify the drawing, the display of the vehicle 12 is omitted and only the in-vehicle terminal device 14 is shown. . FIG. 29A shows a case where no traffic signal is installed at the intersection. As shown, the grouping area is not defined. In order to realize this, the in-vehicle terminal device 14 does not notify the packet signal in which the group information is stored. Therefore, the portable terminal device 110 (not shown) performs a normal operation. Note that whether or not a traffic light is installed at the intersection is stored in the storage unit 84.

  FIG. 29B shows a case where the light color of the traffic light is red, and FIG. 29C shows a case where the light color of the traffic light is blue. When the traffic light is red as shown in FIG. 29 (b), the grouping area 300 is set in the traveling direction of the in-vehicle terminal device 14, and when the traffic light is blue as shown in FIG. 29 (c), the in-vehicle terminal device. The grouping area 300 is set in the left or right turn direction. The relationship between the light color of the traffic light and the direction of the grouping area 300 is reversed in FIGS. 27 (a)-(b) and FIGS. 29 (b)-(c).

2. Adjustment according to the number of pedestrians Information extraction unit 80 receives packet signals from a plurality of portable terminal devices 110. When the number of portable terminal devices 110 is equal to or greater than the threshold value, the area setting unit 82 divides the grouping area. In addition, when the portable terminal device 110 becomes smaller than the threshold value, the area setting unit 82 may combine the grouping areas. That is, the area setting unit 82 changes the size of the grouping area according to the number of communication systems 100 included in the group.

  FIG. 30 is a flowchart illustrating another group setting procedure by the in-vehicle terminal device 14 according to the fifth embodiment of the invention. If the number of portable terminal devices 110 in the grouping area is equal to or greater than the threshold value (Y in S420), the area setting unit 82 divides the grouping area (S422). If the number of portable terminal devices 110 in the grouping area is not greater than or equal to the threshold value (N in S420), the process ends.

3. The adjustment area setting unit 82 according to the traveling direction receives position information from the acquisition unit 64. Further, based on the history of position information, the area setting unit 82 estimates the traveling direction of the vehicle 12 on which the portable terminal device 110 is mounted. In addition, the area setting unit 82 excludes the rear from the position of the vehicle 12 from the grouping area in the traveling direction of the vehicle 12.

4). The adjustment area setting unit 82 according to the distance from the roadway changes the size of the grouping area according to the distance from the roadway. More specifically, the size of the grouping area becomes smaller as it gets closer to the roadway. FIG. 31 shows an outline of another grouping area formation in the communication system 100 according to the fifth embodiment of the present invention. In FIG. 31, an intersection is shown. As illustrated, a plurality of first type grouping areas 310 are set along the roadway. A plurality of second type grouping areas 312 are set at positions farther from the roadway than the first type grouping area 310. Here, the first type grouping area 310 is smaller than the second type grouping area 312. A larger grouping area than the second type grouping area 312 may be set at a position farther from the roadway than the second type grouping area 312.

5. The adjustment area setting unit 82 according to whether the area is a predetermined area changes the size of the grouping area according to whether the area is a predetermined area. Examples of predetermined areas are schools, government offices, public halls, nursing homes, and hospitals. The area setting unit 82 makes the size of the grouping area smaller in these areas than the size of the grouping area other than these areas.

  FIG. 32 is a flowchart showing still another group setting procedure by the in-vehicle terminal device 14 according to the fifth embodiment of the invention. If it is a predetermined area (Y in S430), the area setting unit 82 reduces the size of the grouping area (S432). If it is not a predetermined area (N in S430), the process is terminated.

  According to the embodiment of the present invention, since the grouping area is changed according to the degree of risk, a group suitable for the situation can be formed. Also, broadcast transmission can be effectively executed by a group suitable for the situation. Further, since the size of the grouping area is changed according to the presence / absence of a traffic signal, the danger due to the presence / absence of the traffic signal can be reflected in the size of the grouping area. Further, since the size of the grouping area is changed according to the signal color, the danger due to the signal color can be reflected in the size of the grouping area. Moreover, since the size of the grouping area is changed according to the number of portable terminal devices included in the group, it is possible to suppress the occurrence of a situation where the number of slaves increases excessively.

  Moreover, since the rear from the position of the vehicle is excluded from the grouping area in the traveling direction of the vehicle, portable terminals that are not dangerous can be removed from the group. Further, since the size of the grouping area is changed according to the distance from the roadway, the danger due to the distance from the roadway can be reflected in the size of the grouping area. In addition, since the size of the grouping area is changed according to whether or not it is a predetermined area, it is possible to reduce the risk to traffic weak people.

  In the above, this invention was demonstrated based on the Example. This embodiment is an exemplification, and it will be understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. .

  In the embodiment of the present invention, the in-vehicle terminal devices 14 form a group. However, the present invention is not limited to this. For example, the base station device 10 may form a group. At that time, the base station apparatus 10 includes a grouping execution unit 68. According to this modification, a group can be reliably formed around the base station device 10.

  You may combine Example 1-5 arbitrarily. According to this modification, the effect of any combination of the first to fifth embodiments can be obtained.

  DESCRIPTION OF SYMBOLS 10 Base station apparatus, 12 Vehicle, 14 In-vehicle terminal device, 16 Pedestrian, 20 Antenna, 22 RF part, 24 Modulation / demodulation part, 26 Processing part, 28 Control part, 30 Network communication part, 32 Frame definition part, 34 Selection part , 36 generation unit, 50 antenna, 52 RF unit, 54 modulation / demodulation unit, 56 processing unit, 58 control unit, 60 timing identification unit, 62 transfer determination unit, 64 acquisition unit, 66 generation unit, 68 grouping execution unit, 70 notification Unit, 72 extraction unit, 74 carrier sense unit, 80 information extraction unit, 82 area setting unit, 84 storage unit, 86 selection unit, 88 output unit, 100 communication system, 110 portable terminal device, 120 antenna, 122 RF unit, 124 modulation / demodulation unit, 126 processing unit, 128 control , 130 timing control unit, 132 generating unit, 134 transfer determination unit, 136 obtaining unit, 138 grouping execution unit, 140 extraction unit, 142 the carrier sense unit.

Claims (6)

A receiving unit for receiving signals broadcast from a plurality of wireless devices;
A selection unit that selects one of a plurality of wireless devices based on the signal received by the reception unit;
The selection unit selects a wireless device that is likely to have a long signal notification duration, continues signal notification to the selected wireless device, and stops notification to wireless devices other than the selected wireless device. Control device characterized. The signal received by the receiving unit includes information on the remaining battery level for driving the wireless device,
The control device according to claim 1, wherein the selection unit selects a wireless device with a large remaining battery level as a wireless device that is likely to have a longer signal notification duration.   The control device according to claim 1, wherein the selection unit randomly selects a wireless device as a wireless device that is likely to have a longer signal notification duration.   This control device is mounted on a movable vehicle,
  The control device according to claim 1, wherein each of the plurality of wireless devices is a portable terminal device that is carried by a pedestrian. A receiving unit for receiving signals broadcast from a plurality of wireless devices;
A selection unit that selects one of a plurality of wireless devices based on the signal received by the reception unit;
Each signal received by the receiving unit includes type information of a wireless device that is a notification source,
The selection unit, based on the type information received in the reception unit, selects a wireless device equipped with a transmission function and not equipped with a reception function , continues the signal notification to the selected wireless device, A control device that stops a notification to a wireless device other than the selected wireless device.   This control device is mounted on a movable vehicle,
  The control device according to claim 5, wherein each of the plurality of wireless devices is a portable terminal device carried by a pedestrian.

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