JP6090631B2 - Wireless device - Google Patents

Description

  The present invention relates to communication technology, and more particularly to a radio apparatus that broadcasts 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

  It is desired to reduce the amount of communication processing for such a wireless device.

  The present invention has been made in view of such circumstances, and an object thereof is to provide a technique for reducing communication processing.

  In order to solve the above-described problems, a wireless device according to an aspect of the present invention is a wireless device, and is installed in a vehicle in which a communication unit that performs signal transmission processing and reception processing and another wireless device is mounted. When the estimation unit that estimates whether or not a wireless device is present and the estimation unit estimates that the wireless device is present in a vehicle in which another wireless device is mounted, the communication unit performs transmission processing and A control unit that stops at least one of the reception processes.

  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, communication processing can be reduced.

It is a figure which shows the structure of the communication system which concerns on the Example 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. FIGS. 6A to 6C are views showing a mode in which the portable terminal device carried by the pedestrian in FIG. 1 is attached to the folder. It is a figure which shows the operation | movement outline | summary of the portable terminal device of Fig.6 (a)-(c). It is a figure which shows the structure of the portable terminal device of Fig.6 (a)-(c). It is a figure which shows the structure of the estimation part of FIG. It is a flowchart which shows the process sequence in case the portable terminal device of FIG. It is a flowchart which shows the process sequence in case the portable terminal device of FIG. 8 is only for carrying. It is a flowchart which shows the process sequence in case the portable terminal device of FIG.

  Prior to specific description of the embodiments of the present invention, the underlying knowledge will be described. 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. Furthermore, the driver may get on the vehicle equipped with the terminal device while the driver carries the wireless device. At that time, a packet signal is broadcasted from the wireless device and the terminal device that exist at substantially the same position. As a result, the frequency utilization efficiency is deteriorated as compared with the case where the packet signal is broadcast from either one.

  Next, an outline of an embodiment of the present invention will be described. Embodiments of the present invention relate to a communication system that executes inter-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”. Note that the portable terminal device may execute the same operation as the in-vehicle terminal device in the vehicle. 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 terminal device broadcasts and transmits a packet signal by the CSMA method in a period for performing vehicle-to-vehicle communication other than the road-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.

  As described above, when the portable terminal device is present in the vehicle and the vehicle-mounted terminal device is mounted on the vehicle, a packet signal storing similar data is broadcasted from each. This leads to a deterioration in frequency utilization efficiency and an increase in the collision probability of packet signals. In order to cope with this, the communication system according to the present embodiment executes the following processing. Various types of portable terminal devices are defined. For example, vehicle-only, portable-only, and in-car / mobile-shared. Here, the vehicle-only is a type that operates in the same manner as the vehicle-mounted terminal device, and the portable-only is a type that operates only as a pedestrian terminal device. The portable terminal device according to the present embodiment estimates whether or not it exists in the vehicle. In addition, the portable terminal device executes processing according to the estimation result and type.

  FIG. 1 shows a configuration of a communication system 100 according to an embodiment 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, in particular, 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 location in a 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 in-vehicle terminal device 14 and the portable terminal device 110 notify the packet signal by executing CSMA / CA during the vehicle transmission period. On the other hand, the in-vehicle terminal device 14 and the portable terminal device 110 that cannot receive a packet signal from the base station device 10, that is, the in-vehicle terminal device 14 and the portable terminal device 110 existing outside the area 214 are related to the frame configuration. Instead, the packet signal is broadcast by executing CSMA / CA. Furthermore, the in-vehicle terminal device 14 and the portable terminal device 110 receive the packet signal from the other in-vehicle terminal device 14 and the portable terminal device 110, thereby allowing the vehicle 12 and the pedestrian 16 to approach the driver. Notice. As described above, various types of portable terminal devices 110 are defined, and processing contents differ depending on each type. This will be described later.

  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. 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, an execution unit 68, and a notification unit 70. 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 the 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. In addition, 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 packet signal notification source 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 execution unit 68 executes processing for the received packet signal. In order to clarify the description of the portable terminal device 110, the processing performed by the execution unit 68 in the in-vehicle terminal device 14 is referred to as “in-vehicle mode”. In the in-vehicle mode, for example, (i) a packet signal to be processed and (ii) a risk determination process are defined. First, (i) as the packet signal to be processed, the execution unit 68 processes the data stored in the packet signal from the base station device 10, the in-vehicle terminal device 14, and the portable terminal device 110.

  Next, (ii) as the risk determination process, the execution unit 68 executes the following process. In the case of the vehicle 12, the risk level of the area in the traveling direction is high, and the risk level is relatively low in the left and right and rear areas of the vehicle. In the case of the vehicle 12, it is difficult to change the traveling direction suddenly, and a driver who performs such driving is rare. Therefore, in the danger area (hereinafter referred to as “first danger area”) in the danger judgment process (hereinafter referred to as “first danger judgment process”) in the in-vehicle mode, the traveling direction of the vehicle 12 is relatively larger than the other directions. It is set to a shape.

  When the execution unit 68 receives position information from another in-vehicle terminal device 14 or the portable terminal device 110 located in the first danger area, the execution unit 68 basically notifies the driver of the presence via the notification unit 70. When the location information is received from the in-vehicle terminal device 14 or the portable terminal device 110 located outside the first danger area, the presence is not notified. Even when the execution unit 68 receives position information from another in-vehicle terminal device 14 or the portable terminal device 110 located in the first danger area, the execution unit 68 does not unconditionally notify the presence. The presence or absence of notification may be determined depending on whether or not a predetermined condition is satisfied. For this condition, the traveling direction and the moving speed included in the position information are used.

  For example, when the position information from another vehicle-mounted terminal device 14 is received, the execution unit 68 refers to the traveling direction included in the position information, and the vehicle 12 on which the vehicle-mounted terminal device 14 is mounted It is determined whether the vehicle 12 approaches or leaves. In addition, what is necessary is just to observe the time change of the distance between vehicles when the advancing direction cannot be acquired. When moving away from the own vehicle 12, the execution unit 68 does not cause the notification unit 70 to notify the presence of the vehicle 12 leaving the vehicle 12. Further, even when the vehicle 12 equipped with the in-vehicle terminal device 14 approaches the own vehicle 12, the execution unit 68 determines that the traveling direction of the approaching vehicle 12 and the traveling direction of the own vehicle 12 are the same. If it is substantially opposite, the approaching vehicle 12 is determined as an oncoming vehicle. Therefore, the execution unit 68 does not notify the notification unit 70 of the presence of the vehicle.

  The notification unit 70 includes a monitor and a speaker, and notifies the driver of the approach of another vehicle 12 or a pedestrian 16 (not shown) according to an instruction from the execution unit 68. The control unit 58 controls the operation of the in-vehicle terminal device 14.

  FIGS. 6A to 6C show a mode in which the portable terminal device 110 carried by the pedestrian 16 is attached to the folder 114. FIG. FIG. 6A is a perspective view showing the appearance of the portable terminal device 110. A monitor 116 is provided on one surface of the portable terminal device 110, and a button 112 is provided on the lower surface of the portable terminal device 110. FIG. 6A shows a state where the portable terminal device 110 is carried by a pedestrian. As shown, the button 112 is not pressed. FIG. 6B shows the folder 114 mounted on the vehicle 12 (not shown). The folder 114 is a docking station for mounting the portable terminal device 110. As illustrated, the folder 114 has a shape in which the portable terminal device 110 can be inserted from above.

  FIG. 6C shows a case where the portable terminal device 110 shown in FIG. 6A is attached to the folder 114 shown in FIG. As described above, since the folder 114 is mounted on the vehicle 12, the portable terminal device 110 is mounted on the vehicle 12 when the folder 114 is in a state as shown in FIG. In such a state, the button 112 is pressed by the folder 114. The portable terminal device 110 recognizes the attachment to the folder 114 when the button 112 is pressed, that is, through physical contact between the button 112 and the folder 114. Note that the folder 114 is provided with a power terminal (not shown), and the portable terminal device 110 may be supplied with power via the button 112.

  As described above, various types of portable terminal devices 110 are defined, and are classified into in-vehicle-only, portable-only, and in-vehicle / portable-shared. Here, before explaining the configuration of the portable terminal device 110, an outline of the difference in operation due to the difference in type will be described. FIG. 7 shows an outline of the operation of the portable terminal device 110. Here, an operation when a user carrying the portable terminal device 110 gets into the vehicle 12 is shown. As illustrated, an environmental factor column 300, a user action column 302, a terminal type column 304, an action column 306, an in-vehicle determination algorithm column 308, and an explanation column 310 are included.

  The environmental factor column 300 indicates whether or not the in-vehicle terminal device 14 is mounted on the vehicle 12 on which the user has boarded. The user action column 302 indicates whether or not the user has attached the in-vehicle terminal device 14 to the folder 114 for each case of the environmental factor column 300. The attachment is equivalent to the button 112 being pressed as shown in FIG. The terminal type column 304 indicates the type of the portable terminal device 110 for each case of the user operation column 302. As described above, there are three types of portable terminal device 110. For example, the on-vehicle portable terminal device 110 does not operate as a portable device. The operation column 306 shows an operation for each type of portable terminal device 110. This is an operation after getting into the vehicle 12. An in-vehicle determination algorithm column 308 shows an algorithm for determining that the vehicle is present in the vehicle 12. Here, A, B, and C are defined as algorithms. Details of the operation column 306 and the in-vehicle determination algorithm column 308 will be described later. The explanation column 310 is a number given for convenience in order to clarify the explanation in each case shown in FIG. The following description will be made corresponding to this number.

  FIG. 8 shows the configuration of the portable terminal device 110. 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, a connection unit 150, an estimation unit 152, an instruction unit 154, an execution unit 156, and a notification unit 158. 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 description will be made in the order of the numbers shown in the explanation column 310 of FIG.

In the case of (1) First, the configuration in the case where the portable terminal device 110 is dedicated to the vehicle will be described. The connection unit 150 detects a connection with the folder 114. For example, the connection unit 150 determines that the folder 114 is connected when the button 112 is pressed. On the other hand, when the button 112 is not pressed, the connection unit 150 determines that the connection unit 150 is not connected to the folder 114. Connection unit 150 outputs the determination result to estimation unit 152.

  The estimation unit 152 estimates whether or not the portable terminal device 110 is present in the vehicle 12. Here, three types of algorithms for determining the presence in the vehicle 12 are defined. Hereinafter, these will be described in order as A to C, but these correspond to A to C shown in the in-vehicle determination algorithm column 308 of FIG.

About (A) The estimation part 152 will estimate that it exists in the vehicle 12, when the detection of a connection state is notified from the connection part 150. FIG. Here, in particular, in order to estimate that the vehicle-mounted terminal device 14 is present in the vehicle 12, the following configuration is provided. The folder 114 is electrically connected to the in-vehicle terminal device 14. When the button 112 is connected to the in-vehicle terminal device 14, the portable terminal device 110 and the in-vehicle terminal device 14 are electrically connected. Is done. In this state, when the connection unit 150 receives a signal from the in-vehicle terminal device 14, the estimation unit 152 recognizes that the in-vehicle terminal device 14 exists in the vehicle 12.

About (B) The estimation unit 152 confirms the destination of the packet signal received by the modem unit 124 or the like. When packet signals are received from the same in-vehicle terminal device 14 for a predetermined period, the estimation unit 152 estimates that the vehicle-mounted terminal device 14 is present in the vehicle 12 mounted thereon. In particular, the estimation unit 152 extracts position information included in the received packet signal, and the extracted position information is included in a certain range from the position information acquired by the acquisition unit 136. When continuing for a predetermined period, it is estimated that the vehicle 12 exists. The predetermined period is set to 1 second or 10 seconds, for example. Since the packet signal is broadcast periodically, it may be received periodically over a predetermined period. The algorithm C will be described later.

  The instruction unit 154 detects a connection in the connection unit 150, and when the estimation unit 152 estimates that the vehicle terminal device 14 is mounted in the vehicle 12, the transmission processing is performed on the modem unit 124 and the like. And at least one of the reception processes is stopped. Here, both the transmission process and the reception process are stopped when the estimation unit 152 estimates the presence by the algorithm A, and the transmission process is stopped when the estimation unit 152 estimates the presence by the algorithm B. In these cases, the in-vehicle terminal device 14 executes transmission processing and reception processing. Note that the instruction unit 154 may stop the in-vehicle terminal device 14 from performing transmission processing and reception processing. In that case, transmission processing and reception processing in the modem unit 124 and the like are executed. On the other hand, if it is not estimated that the vehicle 12 exists, that is, if it exists outside the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to stop both transmission processing and reception processing. When the reception process is being executed, the execution unit 156 executes the in-vehicle mode in the same manner as the execution unit 68 in FIG.

In the case of (2), the connection unit 150 does not detect connection with the folder 114. For this reason, the estimation unit 152 estimates that the vehicle-mounted terminal device 14 is present in the vehicle 12 by the algorithm B. When the connection unit 150 does not detect connection and the estimation unit 152 estimates that the vehicle terminal 12 is mounted in the vehicle 12, the instruction unit 154 transmits to the modem unit 124 and the like. Stop processing. On the other hand, if it is not estimated that the vehicle 12 exists, that is, if it exists outside the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to stop both transmission processing and reception processing. The execution unit 156 does not execute the in-vehicle mode.

In the case of (3) The connection unit 150 detects the connection with the folder 114. The estimation unit 152 estimates whether or not it exists in the vehicle 12. At that time, the estimation unit 152 uses the algorithm A or C without using the algorithm B. In the algorithm A, it is not necessary to detect the electrical connection with the in-vehicle terminal device 14, and it is only necessary to detect that the button 112 is pressed.

About (C) The structure of the estimation part 152 in the algorithm C is demonstrated based on FIG. FIG. 9 shows the configuration of the estimation unit 152. The estimation unit 152 includes a measurement unit 160. The measurement unit 160 measures the moving speed. The measurement unit 160 derives the moving speed based on the time change of the position information acquired by the acquisition unit 136. Moreover, the measurement part 160 may acquire a moving speed with a speed sensor. The estimation unit 152 estimates that the vehicle 12 is present when the moving speed measured by the measurement unit 160 becomes higher than the threshold value. For example, the threshold value is set to 20 km / h. Here, a value that cannot be realized by the pedestrian is set as the threshold value. Returning to FIG.

  The instruction unit 154 detects a connection in the connection unit 150, and when the estimation unit 152 estimates that the vehicle terminal device 14 is mounted in the vehicle 12, the transmission processing is performed on the modem unit 124 and the like. And execute reception processing. At that time, the execution unit 156 executes the in-vehicle mode as the reception process in the same manner as the execution unit 68 of FIG. On the other hand, if it is not estimated that the vehicle 12 exists, that is, if it exists outside the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to stop both transmission processing and reception processing.

In the case of (4), the connection unit 150 does not detect connection with the folder 114. Therefore, the estimation unit 152 estimates that the vehicle 12 exists in the algorithm C. When the connection unit 150 does not detect the connection and the estimation unit 152 estimates that the connection unit 150 exists in the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to stop both transmission processing and reception processing. Further, the instruction unit 154 prompts the user to attach the folder 114 via the monitor 116. On the other hand, if it is not estimated that the vehicle 12 exists, that is, if it exists outside the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to stop both transmission processing and reception processing. The execution unit 156 does not execute the in-vehicle mode.

Case (5) Next, a configuration in the case where the portable terminal device 110 is dedicated for carrying will be described. As described above, the connection unit 150 detects the connection with the folder 114. Connection unit 150 outputs the determination result to estimation unit 152. The estimation unit 152 estimates whether or not the portable terminal device 110 is present in the vehicle 12. Here, the estimation unit 152 executes algorithms A and B as algorithms for determining that the vehicle 12 is present in the vehicle 12. The instruction unit 154 detects a connection in the connection unit 150, and when the estimation unit 152 estimates that the vehicle terminal device 14 is mounted in the vehicle 12, the transmission processing is performed on the modem unit 124 and the like. And at least one of the reception processing is stopped. This is the same as in the case of (1). On the other hand, if it is not estimated that the vehicle 12 exists, that is, if it exists outside the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to execute transmission processing and reception processing.

  The execution unit 156 executes processing for the received packet signal. The processing performed by the execution unit 156 of the portable terminal device 110 dedicated for portable use is called “portable mode”. In the portable mode, (i) as a packet signal to be processed, the execution unit 156 stores the packet signal from the base station device 10, the in-vehicle terminal device 14, and other portable terminal devices 110 operating in the in-vehicle mode. The processed data is processed, but the data stored in the packet signal from the other portable terminal device 110 operating in the portable mode is discarded. In the following description, another portable terminal device 110 operating in the in-vehicle mode may be referred to as the in-vehicle terminal device 14 for the sake of clarity.

  This is because when the portable terminal device 110 is operating in the portable mode, the main target for avoiding the danger is the vehicle 12. This is because it is difficult for pedestrians to cause major accidents, and pedestrians cannot be their main targets. Therefore, the portable terminal device 110 only needs to be able to acquire the position of the vehicle 12 located in the vicinity of the pedestrian, and the request for acquiring the positions of other pedestrians located in the vicinity of the pedestrian is low. In this way, the execution unit 156 executes a simpler reception process in the mobile mode than in the in-vehicle mode. This transmission source type is specified with reference to the header of the MAC frame.

  Next, (ii) as a risk determination process, the execution unit 156 executes the following process. In the case of the pedestrian 16, since the traveling speed is slow, it cannot be said that the risk in the area in the traveling direction is high. There is a possibility that the vehicle will rush to the pedestrian 16 from any direction. Therefore, the danger area (hereinafter referred to as “second danger area”) in the danger determination process in the portable mode (hereinafter referred to as “second danger determination process”) is set in a circle around the pedestrian 16. Further, the second dangerous area is defined to be narrower than the first dangerous area. When the execution unit 156 receives position information from the in-vehicle terminal device 14 located in the second danger area in the portable mode, the execution unit 156 basically notifies the pedestrian 16 of the presence via the notification unit 158. On the other hand, when the execution unit 156 receives position information from the in-vehicle terminal device 14 located outside the second danger area, the execution unit 156 does not notify the presence.

  Even when the execution unit 156 receives the position information from the in-vehicle terminal device 14 located in the second danger area in the portable mode, the execution unit 156 does not notify the existence unconditionally but satisfies the predetermined condition. The presence or absence of notification may be determined depending on the above. Similar to the in-vehicle mode, the traveling direction included in the position information is used for the condition. For example, when position information is received from the in-vehicle terminal device 14, the traveling direction included in the position information is referred to, and the in-vehicle terminal device 14 on which the in-vehicle terminal device 14 is mounted approaches the pedestrian 16. Determine whether to come or leave. When going away, the presence of the vehicle 12 going away is not notified. Note that the instruction unit 154 may execute the transmission process in the portable mode at a lower frequency than the transmission process in the in-vehicle mode.

In the case of (6), the connection unit 150 does not detect connection with the folder 114. Therefore, the estimation unit 152 estimates that the vehicle 12 exists in the algorithm B. When the connection unit 150 does not detect the connection and the estimation unit 152 estimates that the connection unit 154 is present in the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to stop transmission processing. On the other hand, if it is not estimated that the vehicle 12 exists, that is, if it exists outside the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to execute transmission processing and reception processing. The execution unit 156 uses the mobile mode when executing the reception process.

In the case of (7) The connection unit 150 detects the connection with the folder 114. The estimation unit 152 estimates whether or not it exists in the vehicle 12. At that time, the estimation unit 152 uses the algorithm A or C without using the algorithm B. The instruction unit 154 detects a connection in the connection unit 150 and causes the modem unit 124 and the like to stop both transmission processing and reception processing when the estimation unit 152 estimates that the connection unit 150 exists in the vehicle 12. On the other hand, if it is not estimated that the vehicle 12 exists, that is, if it exists outside the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to execute transmission processing and reception processing. At that time, the execution unit 156 executes the portable mode as the reception process.

In the case of (8), the connection unit 150 does not detect connection with the folder 114. The estimation unit 152 estimates that the vehicle 12 exists in the algorithm C. When the connection unit 150 does not detect the connection and the estimation unit 152 estimates that the connection unit 150 exists in the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to stop both transmission processing and reception processing. On the other hand, if it is not estimated that the vehicle 12 exists, that is, if it exists outside the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to execute transmission processing and reception processing. At that time, the execution unit 156 executes the portable mode as the reception process.

Case (9) Finally, the configuration in the case where the portable terminal device 110 is in-vehicle / portable will be described. Since the processes of the connection unit 150 and the estimation unit 152 are the same as in the case of (1), description thereof is omitted here. The instruction unit 154 detects a connection in the connection unit 150, and when the estimation unit 152 estimates that the vehicle terminal device 14 is mounted in the vehicle 12, the transmission processing is performed on the modem unit 124 and the like. And at least one of the reception processes is stopped. This is also the same as in the case of (1), and the execution unit 156 executes the in-vehicle mode when the reception process is being executed.

  On the other hand, if it is not estimated that the vehicle 12 exists, that is, if it exists outside the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to execute transmission processing and reception processing. This is the same as in the case of (5), and the execution unit 156 executes the mobile mode when the reception process is being executed. In this way, the instruction unit 154 performs the reception process in the in-vehicle mode instead of causing the modem unit 124 or the like to stop the reception process in the portable mode when the estimation unit 152 estimates that the vehicle 12 is present in the vehicle 12. Let it run.

In the case of (10), the connection unit 150 does not detect connection with the folder 114. The estimation unit 152 estimates that the vehicle-mounted terminal device 14 is present in the vehicle 12 with the algorithm B. When the connection unit 150 does not detect connection and the estimation unit 152 estimates that the vehicle terminal 12 is mounted in the vehicle 12, the instruction unit 154 transmits to the modem unit 124 and the like. Stop processing. On the other hand, if it is not estimated that the vehicle 12 exists, that is, if it exists outside the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to execute transmission processing and reception processing. The execution unit 156 executes the mobile mode when the reception process is being executed.

In the case of (11) The connection unit 150 detects the connection with the folder 114. The estimation unit 152 estimates whether or not it exists in the vehicle 12. At that time, the estimation unit 152 uses the algorithm A or C. The instruction unit 154 detects a connection in the connection unit 150, and when the estimation unit 152 estimates that the vehicle terminal device 14 is mounted in the vehicle 12, the transmission processing is performed on the modem unit 124 and the like. And execute reception processing. At that time, the execution unit 156 executes the in-vehicle mode as the reception process. On the other hand, if it is not estimated that the vehicle 12 exists, that is, if it exists outside the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to execute transmission processing and reception processing. At that time, the execution unit 156 executes the portable mode as the reception process.

In the case of (12) The connection unit 150 does not detect the connection with the folder 114. Therefore, the estimation unit 152 estimates that the vehicle 12 exists in the algorithm C. When the connection unit 150 does not detect the connection and the estimation unit 152 estimates that the connection unit 150 exists in the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to stop both transmission processing and reception processing. Further, the instruction unit 154 prompts the user to attach the folder 114 via the monitor 116. On the other hand, if it is not estimated that the vehicle 12 exists, that is, if it exists outside the vehicle 12, the instruction unit 154 causes the modem unit 124 and the like to execute transmission processing and reception processing. At that time, the execution unit 156 executes the portable mode as the reception process.

  The operation of the communication system 100 configured as above will be described. FIG. 10 is a flowchart showing a processing procedure when the portable terminal device 110 is dedicated for in-vehicle use. If the connection unit 150 detects a connection (Y in S10) and the estimation unit 152 does not estimate that the in-vehicle terminal device 14 is present (N in S12), the execution unit 156 operates in the in-vehicle mode (S14). ). On the other hand, if the connection unit 150 does not detect the connection (N in S10) or the estimation unit 152 estimates that there is the in-vehicle terminal device 14 (Y in S12), the execution unit 156 stops the process. (S16).

  FIG. 11 is a flowchart showing a processing procedure when the portable terminal device 110 is dedicated to carrying. If the connection unit 150 does not detect a connection (N in S20) and the estimation unit 152 does not estimate that the vehicle is in the vehicle (N in S22), the execution unit 156 operates in the portable mode (S24). On the other hand, if the connection unit 150 detects a connection (Y in S20) or estimates that the estimation unit 152 is in the vehicle (Y in S22), the execution unit 156 stops the process (S26).

  FIG. 12 is a flowchart showing a processing procedure when the portable terminal device 110 is in-vehicle / portable. If the connection unit 150 does not detect a connection (N in S30) and the estimation unit 152 does not estimate that the vehicle is in the vehicle (N in S34), the execution unit 156 operates in the portable mode (S36). If the estimation unit 152 estimates that the vehicle is in the vehicle (Y in S34), the execution unit 156 stops the process (S38). On the other hand, if the connection unit 150 detects a connection (Y in S30) and the estimation unit 152 estimates that there is the in-vehicle terminal device 14 (Y in S32), the execution unit 156 stops the process (S38). ). If the estimation unit 152 does not estimate that the in-vehicle terminal device 14 is present (N in S32), the execution unit 156 operates in the in-vehicle mode (S40).

  According to the embodiment of the present invention, even when the portable terminal device is brought into the vehicle, the processing is changed according to the type of the portable terminal device, so that the frequency utilization efficiency can be improved. Further, if the vehicle-mounted terminal device is mounted on the vehicle, the portable terminal device is stopped using the vehicle-mounted terminal device, so that the power consumption of the portable terminal device can be reduced. Moreover, since it does not perform vehicle-mounted mode when not mounting | wearing with a folder, a driver | operator can be made to perform safe driving | operation. Moreover, since it carries out portable mode when it exists outside a vehicle, the danger that a pedestrian will be involved in a collision accident can be reduced. Therefore, communication processing of the portable terminal device can be reduced.

  Moreover, since it estimates that it exists in a vehicle when connected to a folder, estimation accuracy can be improved. Further, when the moving speed becomes high, it is estimated that the vehicle exists in the moving vehicle, and therefore it can be estimated by the portable terminal device alone. Further, when packet signals from the same in-vehicle terminal device are received in a predetermined period, it is estimated that the in-vehicle terminal device is present in the vehicle, so that it can be estimated with high accuracy. Further, when it is estimated that the vehicle exists in the vehicle, a different process from that in the case where it is estimated that the vehicle exists outside the vehicle is executed, so that the terminal device can be used for both pedestrian use and on-vehicle use.

  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. .

  The outline of one embodiment of the present invention is as follows. A wireless device according to an aspect of the present invention is a wireless device, and whether or not the wireless device is present in a vehicle in which a communication unit that performs signal transmission processing and reception processing and another wireless device is mounted. And when the estimation unit estimates that the wireless device is present in a vehicle equipped with another wireless device, the communication unit performs at least one of transmission processing and reception processing. And a control unit for stopping.

  According to this aspect, when it is estimated that the wireless device is present in a vehicle on which another wireless device is mounted, at least one of the transmission process and the reception process is stopped, so that the communication process can be reduced.

  Another aspect of the present invention is also a wireless device. This device is a wireless device, and includes a communication unit that performs signal transmission processing and reception processing, an estimation unit that estimates whether or not the wireless device is present in the vehicle, and an estimation unit in the vehicle. A control unit that stops at least one of the transmission process and the reception process with respect to the communication unit when it is estimated that the wireless device is present.

  According to this aspect, when it is estimated that the wireless device is present in the vehicle, at least one of the transmission process and the reception process is stopped, so that the communication process can be reduced.

  You may further provide a connection part. The estimation unit may estimate that the wireless device is present when the connection state in the connection unit is detected. In this case, when the connection state is detected, it is estimated that the wireless device is present in the vehicle, so that the estimation accuracy can be improved.

  You may further provide the measurement part which measures a moving speed. The estimation unit may estimate that the wireless device is present when the moving speed measured by the measurement unit is higher than a threshold value. In this case, when the moving speed becomes high, it is estimated that the wireless device is present in the vehicle, so that the wireless device alone can be estimated.

  The estimation unit may estimate that the wireless device is present when the communication unit receives a signal from the same other wireless device for a predetermined period. In this case, the estimation accuracy can be improved.

  When the estimation unit estimates that the wireless device is present in the vehicle, the control unit performs another process for the communication unit instead of at least one of the stopped transmission process and reception process. You may let them. In this case, different processes can be executed inside and outside the vehicle.

  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 execution unit, 70 notification unit, 72 extraction unit, 74 carrier sense unit, 100 communication system, 110 portable terminal device, 112 button, 114 folder, 120 antenna, 122 RF unit, 124 modulation / demodulation unit, 126 processing unit, 128 control unit, 130 timing control unit, 132 Generator, 13 4 transfer determination unit, 136 acquisition unit, 140 extraction unit, 142 carrier sense unit, 150 connection unit, 152 estimation unit, 154 instruction unit, 156 execution unit, 158 notification unit, 160 measurement unit.

  According to the present invention, communication processing can be reduced.

Claims (5)

A wireless device that broadcasts a signal including location information of the device itself by a wireless method using the CSMA method,
A communication unit that performs signal transmission processing and reception processing;
This is another wireless device that corresponds to the same wireless method as this wireless method and that reports a signal including the position information of the own device by the CSMA method , and this wireless device is installed in a vehicle in which the other wireless device is mounted. An estimator for estimating whether the device exists;
When the estimation unit estimates that the wireless device is present in a vehicle in which another wireless device is mounted, at least one of signal transmission processing and reception processing in the wireless system is performed on the communication unit. A control unit for stopping
A wireless device comprising: A connecting portion;
The wireless device according to claim 1, wherein the estimation unit estimates that the wireless device is present when a connection state in the connection unit is detected. It further comprises a measuring unit that measures the moving speed,
The wireless device according to claim 1, wherein the estimating unit estimates that the wireless device is present when a moving speed measured by the measuring unit is higher than a threshold value.   The wireless device according to claim 1, wherein the estimation unit estimates that the wireless device is present when the communication unit receives a signal from the same other wireless device in a predetermined period.   When the estimation unit estimates that the wireless device is present in the vehicle, the control unit may replace the communication unit with at least one of the stopped transmission process and reception process. The wireless device according to claim 1, wherein processing is executed.

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