JP5963599B2 - Portable terminal device - Google Patents

Description

  The present invention relates to communication technology, and more particularly to a portable terminal device that transmits a signal including predetermined information.

  In the Intelligent Transport System (ITS), road-to-vehicle communication between a base station that is a roadside device and a mobile station that is a vehicle-mounted device and vehicle-to-vehicle communication that is communication between mobile stations is defined (for example, Non-Patent Document 1). Here, exclusive control is performed by time-sharing one channel, and each roadside device secures a communication period and transmits road-to-vehicle communication period information to the vehicle-mounted device. Furthermore, other in-vehicle devices transfer road-to-vehicle communication period information to the in-vehicle devices that exist outside the area where the roadside device can communicate, thereby making the information known (see, for example, Patent Document 1).

JP 2011-234400 A

700MHz band Intelligent Transport System ARIB STD T-109 1.0 Edition, Radio Industries Association, February 2012

  When considering the introduction of pedestrian terminals that are carried by pedestrians in addition to roadside units and in-vehicle devices, this is a compact and battery-powered portable terminal compared to in-vehicle devices, which simplifies processing. And power saving are necessary. Therefore, a practical process is required.

  This invention is made | formed in view of such a condition, The objective is to provide the technique which reduces the processing amount in the terminal device carried by a pedestrian rather than the terminal device mounted in a vehicle. .

  In order to solve the above-described problem, a portable terminal device according to an aspect of the present invention provides a mobile terminal device that transmits time-division multiplexed frames from a base station device in a road-vehicle transmission period. A reception unit that receives the packet signal in which the period information about the road and vehicle transmission period is stored, and a transmission unit that transmits the packet signal in the vehicle transmission period of the frame. The receiving unit receives the packet signal from the in-vehicle terminal device having a function for transferring the period information stored in the packet signal from the base station device in the vehicle transmission period of the frame, and the transmitting unit The period information stored in the packet signal received by the receiving unit is not transferred.

  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.

  ADVANTAGE OF THE INVENTION According to this invention, the processing amount in the terminal device carried by a pedestrian can be reduced rather than the terminal device mounted in a vehicle.

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. It is a figure which shows the timing of the flame | frame shown by Fig.3 (a)-(d). It is a figure which shows the structure of the vehicle-mounted terminal device mounted in the vehicle of FIG. 6A to 6E are diagrams illustrating a layer structure defined in the communication system of FIG. It is a figure which shows the detail of the structure of the IR control field prescribed | regulated in the communication system of FIG. 1, and road-to-vehicle communication period information. It is a figure which shows the road-to-vehicle communication period information transfer operation | movement by the vehicle-mounted terminal device of FIG. It is a figure which shows the internal setting of the road-vehicle communication period in the vehicle-mounted terminal device of FIG. It is a figure which shows the transfer setting of the road-vehicle communication period in the vehicle-mounted terminal device of FIG. It is a figure which shows the structure of the portable terminal device carried by the pedestrian of FIG. It is a figure which shows the road-to-vehicle communication period information transfer operation | movement by the portable terminal device of FIG. It is a figure which shows the internal setting of the road-vehicle communication period in the portable terminal device of FIG. It is a figure which shows the transfer setting of the road-to-vehicle communication period in the portable terminal device of FIG.

  Prior to specific description of the embodiments of the present invention, the underlying knowledge will be described. The embodiment of the present invention performs inter-vehicle communication between in-vehicle terminal devices mounted on a vehicle, and also executes road-to-vehicle communication from a base station device installed at an intersection or the like to an in-vehicle terminal device. The present invention relates to a communication system that also executes inter-step communication between a portable terminal device carried by a person and a terminal device mounted on a vehicle. Such a communication system is also called ITS (Intelligent Transport Systems). The communication system uses an access control function called CSMA / CA (Carrier Sense Multiple Access Collision Aviation), as well as a wireless LAN (Local Area Network) compliant with a standard such as IEEE 802.11. Therefore, the same radio channel is shared by a plurality of terminal devices. On the other hand, in ITS, it is necessary to transmit information to an unspecified number of terminal devices. In order to efficiently perform such transmission, the communication system broadcasts a packet signal.

  That is, as the inter-vehicle communication, the in-vehicle terminal device broadcasts a packet signal storing information such as the speed or position of the vehicle. Other in-vehicle terminal devices receive the packet signal and recognize the approach of the vehicle based on the information described above. As inter-pedal communication, the portable terminal device broadcasts a packet signal that stores information such as the speed and position of the pedestrian. The in-vehicle terminal device receives the packet transmitted from the portable terminal device and recognizes the approach of a pedestrian based on the above information. Here, in order to reduce interference between road-to-vehicle communication and vehicle-to-vehicle / step-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 in-vehicle terminal device and the portable terminal device specify the road and vehicle transmission period based on the control information, and in the period other than the road and vehicle transmission period (hereinafter referred to as “vehicle transmission period”), the packet signal is transmitted by the CSMA method. Broadcast. As a result, road-to-vehicle communication and inter-vehicle / step-to-vehicle communication are time-division multiplexed. In-vehicle terminal devices and portable terminal devices that cannot receive control information from the base station device, that is, in-vehicle terminal devices and portable terminal devices that exist outside the area formed by the base station device have a frame configuration. Regardless of whether the packet signal is transmitted by the CSMA method.

  Next, an outline of the present embodiment will be described. Hereinafter, the in-vehicle terminal device and the portable terminal device may be referred to as “terminal device” without being distinguished, and the in-vehicle terminal device and the portable terminal device may be collectively referred to as “terminal device”. For example, the portable terminal device is battery-driven. Here, for the purpose of reducing the power consumption of the portable terminal device, simplification of processing of the portable terminal device is required as compared with the in-vehicle terminal device. Therefore, the in-vehicle terminal device transfers control information, but the portable terminal device does not transfer control information. Hereinafter, even when a portable terminal device is used, it may be referred to as vehicle-to-vehicle communication, road-to-vehicle communication, or broadcast transmission or notification.

  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. , An eighth vehicle 12h, a ninth vehicle 12i, a tenth vehicle 12j, and a network 202. Here, only the first vehicle 12a is shown, but the vehicle-mounted terminal device 14 is mounted on each vehicle 12. The pedestrian 16 has a portable terminal device 18. 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, the fourth vehicle 12d, the ninth vehicle 12i, and the tenth vehicle 12j are traveling from right to left. Yes. 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. Only the ninth vehicle 12 i and the tenth vehicle 12 j exist outside the area 214, and other vehicles exist within the area 212.

  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 apparatus 10 receives a frame including a plurality of subframes based on a signal received from a GPS (Global Positioning System) satellite (not shown) or a frame formed by another base station apparatus 10 (not shown). Generate repeatedly. 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, accident information, traffic jam information, signal information, and the like. Note that the packet signal also includes information related to the timing when the road and vehicle transmission period is set and control information related to the frame.

  As described above, the in-vehicle terminal device 14 is mounted on the vehicle 12 and is movable. Moreover, the portable terminal device 18 is also carried by a pedestrian and can be moved. When receiving the packet signal from the base station device 10, the in-vehicle terminal device 14 and the portable terminal device 18 estimate that they exist in the area 212. When the in-vehicle terminal device 14 and the portable terminal device 18 exist in the area 212, based on the control information included in the packet signal, in particular, the information on the timing when the road and vehicle transmission period is set and the information on the frame, Generate a frame. As a result, the frames generated in each of the plurality of in-vehicle terminal devices 14 and the portable terminal device 18 are synchronized with the frames generated in the base station device 10. The in-vehicle terminal device 14 and the portable terminal device 18 notify a packet signal in a vehicle / pedestrian transmission period (hereinafter also referred to as “vehicle transmission period”) which is a period different from the road-vehicle transmission period. . Here, CSMA / CA is executed in the vehicle transmission period. On the other hand, when it is estimated that the in-vehicle terminal device 14 and the portable terminal device 18 exist outside the area 214, the packet signal is notified by executing CSMA / CA regardless of the frame configuration.

  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 30, and a network communication unit 28. 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 18, or another base station device 10 (not shown) by the antenna 20 as a reception process. 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 Trans) 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. It can be said that the frame is formed by multiplexing the subframes that can be used for notification by the in-vehicle terminal device 14 for a plurality of times. For example, when the frame length is 100 msec and N is 16, a subframe having a length of 6.25 msec is defined. N may be other than 16. 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. The selection unit 34 receives an instruction regarding the selected subframe via an interface (not shown). The selection unit 34 selects a subframe corresponding to the instruction. Apart from this, the selection unit 34 may automatically select a subframe. At that time, the selection unit 34 inputs a demodulation result from another base station device 10 or the in-vehicle terminal device 14 (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 is no unused subframe, 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 the 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 18 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. It is defined that the terminal device 14 and the portable terminal device 18 can report the packet signal. 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.

  FIG. 4 shows frame timing. As described above, the frame period is indicated as 100 ms as the control period. “1” to “16” is a period in which the road and vehicle transmission period can be set, and is a period of “maximum 3024 μs”. 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 a packet signal to be notified during the road and vehicle transmission period. When a plurality of packet signals are transmitted in one road and vehicle transmission period, the generation unit 36 generates them. The packet signal is composed of control information and a payload. The control information includes a packet transmission time, a subframe number in which a road and vehicle transmission period is set, and the like. The payload includes, for example, accident information, traffic jam information, signal information, and the like. These data are acquired from the network 202 (not shown) by the network communication unit 28. The processing unit 26 broadcasts the packet signal to the modem unit 24 and the RF unit 22 during the road and vehicle transmission period. The control unit 30 controls processing of the entire base station apparatus 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 40, an RF unit 42, a modem unit 44, a processing unit 46, and a control unit 48. The processing unit 46 includes a timing specifying unit 50, a transfer determination unit 56, an acquisition unit 58, and a notification unit 60. The generation unit 62 is included. The timing specifying unit 50 includes an extraction unit 52 and a carrier sense unit 54. The antenna 40, the RF unit 42, and the modem unit 44 perform the same processing as the antenna 20, the RF unit 22, and the modem unit 24 in FIG. Therefore, here, the difference will be mainly described.

  The modem unit 44 and the processing unit 46 of the in-vehicle terminal device 14 receive packets from other in-vehicle terminal devices 14, the portable terminal device 18, and the base station device 10 (not shown) according to the ITS communication method described in FIG. Receive a signal. As described above, the modem unit 44 and the processing unit 46 receive the packet signal from the base station apparatus 10 during the road and vehicle transmission period. Further, the modem unit 44 and the processing unit 46 receive packet signals from other in-vehicle terminal devices 14 and portable terminal devices 18 in the vehicle transmission period.

  When the demodulation result from the modem unit 44 is a packet signal from the base station device 10 (not shown), the extraction unit 52 estimates that the signal is present in the area 212 in FIG. 1 and is mounted on the vehicle at the time of the base station device 10. The time of the terminal device 14 is synchronized. Furthermore, the timing of the sub-frame where the road and vehicle transmission period is arranged is specified. The extraction unit 52 generates a frame based on the timing of the subframe and the content of the message header of the packet signal, specifically, the content of the road and vehicle transmission period length. Note that the generation of the frame only needs to be performed in the same manner as the frame defining unit 32 described above, and thus the description thereof is omitted here. As a result, the extraction unit 52 generates a frame synchronized with the frame formed in the base station device 10. When receiving packets from a plurality of base station apparatuses 10, a frame is generated by combining subframes in which road and vehicle transmission periods of the packets are arranged. The extraction unit 52 selects a vehicle transmission period. When the vehicle transmission period is selected, the extraction unit 52 outputs information on the frame and subframe timing and the vehicle transmission period to the carrier sense unit 54.

  On the other hand, when the extraction unit 52 has not received the packet signal of the base station, the extraction unit 52 estimates that the extraction unit 52 exists outside the area 214 in FIG. When it is estimated that the extraction unit 52 exists outside the area 214, the extraction unit 52 selects a timing unrelated to the frame configuration. When the extraction unit 52 selects a timing unrelated to the frame configuration, the extraction unit 52 instructs the carrier sense unit 54 to execute carrier sense.

  The carrier sense unit 54 receives information regarding the timing of the frames and subframes and the vehicle transmission period from the extraction unit 52. The carrier sense unit 54 measures the interference power by executing carrier sense during the vehicle transmission period. Moreover, the carrier sense part 54 determines the transmission timing in a vehicle transmission period based on interference power. More specifically, the carrier sense unit 54 stores a predetermined threshold value in advance, and compares the interference power with the threshold value. If the interference power is smaller than the threshold value, the carrier sense unit 54 determines the transmission timing. When the carrier sense unit 54 is instructed by the extraction unit 52 to execute carrier sense, the carrier sense unit 54 determines the transmission timing by executing CSMA without considering the frame configuration. The carrier sense unit 54 notifies the generation unit 62 of the determined transmission timing.

  The acquisition unit 58 includes a GPS receiver, a gyro sensor, a vehicle speed sensor, and the like (not shown). Based on data supplied from the GPS receiver, the presence position, the traveling direction, the moving speed, and the like (hereinafter referred to as “position”). (Collectively referred to as “information”). 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 58 outputs the position information to the generation unit 62.

  The transfer determination unit 56 controls the transfer of the message header. The transfer determination unit 56 extracts a message header from the packet signal. When the packet signal is directly transmitted from the base station apparatus 10, for example, “transfer twice” is set, but when the packet signal is transmitted to another in-vehicle terminal apparatus 14, The transfer count is reduced by 1 and set to the value of “transfer once”. The transfer determination unit 56 selects a message header to be transferred from the extracted message header. Here, for example, the message header with the largest number of transfers is selected. In addition, the transfer determination unit 56 may generate a new message header by combining the contents included in the plurality of message headers. The transfer determination unit 56 outputs the message header to be selected to the generation unit 62. At that time, the transfer determination unit 56 decreases the transfer count by one.

  The generation unit 62 receives position information from the acquisition unit 58 and receives a message header from the transfer determination unit 56. The generation unit 62 generates a packet signal including a MAC frame, and broadcasts the generated packet signal via the modem unit 44, the RF unit 42, and the antenna 40 at the transmission timing determined by the carrier sense unit 54. Send. This corresponds to vehicle / walking wheel communication. The transmission timing is included in the vehicle transmission period.

  The notification unit 60 obtains a packet signal from the base station device 10 (not shown) via the extraction unit 52 and also obtains a packet signal from other in-vehicle terminal device 14 and portable terminal device 18 (not shown). As a process for the acquired packet signal, the notification unit 60 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. Further, the notification unit 60 notifies the driver of obstacle detection information, traffic jam information, lamp color information, and the like via a monitor or a speaker.

  6A to 6E show a layer structure defined by the communication system 100. FIG. 6 (a) shows the frame format of the physical layer, FIG. 6 (b) shows the frame format of the MAC layer, FIG. 6 (c) shows the frame format of the LLC layer, and FIG. 6 (d) shows the vehicle format. The inter-vehicle / road-vehicle shared communication control information layer frame format is shown, and FIG. 6 (e) shows the L7 layer frame format. Among these, information related to propagation in the road-to-vehicle transmission period is defined in the “IR control field” included in the inter-vehicle / road-vehicle shared communication control information layer.

  FIG. 7 shows details of the structure of the IR control field defined in the communication system 100 and road-to-vehicle communication period information. From the head of the IR control field, 4-bit version information, 4-bit identification information, 3-bit synchronization information, 1-bit reservation, 20-bit transmission time, 128-bit road-to-vehicle communication period information, 16-bit information An extended area is located. The IR control field is 22 bytes in total.

  Here, further details of road-to-vehicle communication period information are shown. As shown in FIG. 4, since 16 subframes are defined in a control cycle of 100 ms, 16 road-to-vehicle communication periods can be defined. The “road-vehicle communication period” here corresponds to the “road-vehicle transmission period” described above. Each is indicated by a road-to-vehicle communication period 1 to a road-to-vehicle communication period 16, and 1 byte is allocated to each communication period. Here, the upper 2 bits (b7 and b6) indicate the number of transfers. When b7 and b6 are both 0, this indicates that no transfer is performed. When b7 is 0 and b6 is 1, transfer is performed once and b7 is 1 , B6 is 0, it means two transfers, and when b7, b6 are both 1, it means three transfers.

  The lower 6 bits (b5 to b0) indicate the road-to-vehicle communication period length. If 0 (all 0 from b5 to b0), this indicates that there is no road-to-vehicle communication period. This indicates that a communication period exists, and the road-to-vehicle communication period length is indicated by a numerical value. If 1 (b5 to b1 is 0, b0 is 1), the road-to-vehicle communication period length is 48 μs, and 2 (b5 to b2, b0 is 0, b1 is 1) is 96 μs. Further, every time 1 is increased, the period length of 48 μs increases, and in the case of 63 (all 1 from b5 to b0), the road-to-vehicle communication period length is 3024 μs at the maximum.

  FIG. 8 shows the road-to-vehicle communication period information transfer operation by the in-vehicle terminal device 14. For example, the base station device 10 has a road-to-vehicle communication period 1 of the road-to-vehicle communication period information in FIG. 7, the transfer count is 1 (b7 is 0, b6 is 1), and the road-to-vehicle communication period length is 3024 μs (b5 to b0 are 63) is transmitted. The fourth in-vehicle terminal device 14d in the area 212 that has received it confirms that the road-to-vehicle transmission period of 3024 μs is defined in the road-to-vehicle communication period 1 and the number of transfers is one, and the next outgoing call When this information is transferred. Specifically, the road-to-vehicle communication period 1 is transmitted by transmitting the road-to-vehicle communication period 1 with 0 transfer times (both b7 and b6 are both 0) and the road-to-vehicle communication period length of 3024 μs (b5 to b0 is 63). Will be transferred.

  When the 9th in-vehicle terminal device 14i outside the area 214 receives this transmission signal, it confirms that the road-to-vehicle transmission period of 0,024 and 3024 μs is defined in the road-to-vehicle communication period 1. No transfer is performed because the transfer count is 0. Specifically, transmission is performed with the road-to-vehicle communication period 1 set to 0 transfer times (both b7 and b6 are both 0) and the road-to-vehicle communication period length is also 0 (b5 to b0 are all 0). When the tenth in-vehicle terminal device 14j outside the area 214 receives this transmission signal, it recognizes that the road-to-vehicle communication period is not defined in the road-to-vehicle communication period 1.

  In addition to indicating the road-to-vehicle communication period, the IR control field also includes a mechanism for synchronizing the in-vehicle terminal device 14 with the reference time of the base station device 10. By using the synchronization information and transmission time in the IR control field, the control period of 100 ms is synchronized. As a result, switching between the road and vehicle transmission period and the vehicle transmission period is synchronized between the base station apparatus 10 and the in-vehicle terminal apparatus 14 in the area 212. FIG. 8 is an example of the transfer of road-to-vehicle communication period information to one base station device 10, but an actual in-vehicle terminal device 14 includes a plurality of base station devices 10 and a plurality of other in-vehicle terminal devices 14. The road-to-vehicle communication period information is updated by receiving a transmission signal from the vehicle.

  FIG. 9 shows the internal setting of the road-to-vehicle communication period in the in-vehicle terminal device 14. This corresponds to an internal setting state of the road-to-vehicle communication period in the in-vehicle terminal device 14 that has received signals from the plurality of base station devices 10 and the plurality of other in-vehicle terminal devices 14. Among the road-to-vehicle communication periods that can be set at 16 locations, four road-to-vehicle transmission periods of road-to-vehicle communication period 1, road-to-vehicle communication period 4, road-to-vehicle communication period 6, and road-to-vehicle communication period 9 are set. The number of transfers in each road-to-vehicle communication period is 2, 2, 1, and 0. Each road-to-vehicle communication period length is 3024 μs, 3024 μs, 1440 μs, and 1920 μs. As described above, one subframe is obtained by dividing 100 ms by 16, but one subframe length is 6.24 ms except for the last 16th subframe, and only the 16th subframe is 6.40 m. It is defined as

  FIG. 9 shows the start time of each road-vehicle communication period. The range of the road-to-vehicle communication period 1 from the start time and the road-to-vehicle communication period length is 0 ms to 3.024 ms, the range of the road-to-vehicle communication period length 4 is 18.72 ms to 21.744 ms, and the range of the road-to-vehicle communication period length 6 is The range of 31.20 ms to 32.640 ms and the road-to-vehicle communication period length 9 is 49.92 ms to 51.840 ms. On the in-vehicle terminal device 14 side, a NAV (Network Allocation Vector) is set so that transmission is prohibited during these communication period lengths. More specifically, a guard time is provided before and after this period length, and before that, an amount corresponding to the transmission time of the transmission packet is added to the NAV period. This guard time is for absorbing the synchronization error of the time of the in-vehicle terminal device 14, and the transmission time corresponding to the transmission packet enters the road-to-vehicle communication period before the packet transmission ends when performing packet transmission. This is to avoid that.

  FIG. 10 shows the transfer setting for the road-to-vehicle communication period in the in-vehicle terminal device 14. The number of transfers for road-to-vehicle communication periods 1, 4, and 6 and the road-to-vehicle communication period length 9 are different from those in FIG. If the number of transfers is other than 0, the number of transfers is reduced by one. Road-to-vehicle communication period 1, road-to-vehicle communication period 4, and road-to-vehicle communication period 6 correspond to this. Since the road-to-vehicle communication period 9 in which the transfer count is 0 is not transferred any more, the road-to-vehicle communication period length is set to 0.

  FIG. 11 shows a configuration of the portable terminal device 18 carried by the pedestrian 16. The portable terminal device 18 includes an antenna 70, an RF unit 72, a modem unit 74, a processing unit 76, and a control unit 78. The processing unit 76 includes an acquisition unit 80, a generation unit 82, a timing identification unit 84, an extraction unit 86, and a notification unit 94, and the timing identification unit 84 includes a carrier sense unit 90 and a pattern holding unit 92. The antenna 70, the RF unit 72, the modem unit 74, and the acquisition unit 80 perform the same processing as the antenna 40, the RF unit 42, the modem unit 44, and the acquisition unit 58 of FIG. Therefore, here, the difference will be mainly described.

  The RF unit 72 and the modulation / demodulation unit 74 are packet signals from the base station apparatus 10 in the road and vehicle transmission period of the frame in which the road and vehicle transmission period and the vehicle and vehicle transmission period are time-division multiplexed. A packet signal in which a field is stored is received. The RF unit 72 and the modem unit 74 also receive a packet signal from the in-vehicle terminal device 14 in the vehicle transmission period of the frame. As described above, the in-vehicle terminal device 14 has a function for transferring the road-to-vehicle communication period length stored in the packet signal from the base station device 10.

  The timing identification unit 50 of the in-vehicle terminal device 14 includes an extraction unit 52 and a carrier sense unit 54, while the timing identification unit 84 of the portable terminal device 18 includes a carrier sense unit 90 and a pattern holding unit 92. In the case of the in-vehicle terminal device 14, the extraction unit 52 specifies the road-to-vehicle transmission period from the base station device 10 and determines the other as the vehicle-to-vehicle transmission period. The entire area definable by the device 10 is defined as a road-to-vehicle communication period, and the other areas are determined as vehicle-to-vehicle transmission periods. Such a pattern in the portable terminal device 18 is held in advance in the pattern holding unit 92. This corresponds to the timing specifying unit 84 setting the vehicle transmission period other than the period during which the road and vehicle transmission period can be set, regardless of whether the road and vehicle transmission period is actually set. . The whole area that can be defined by the base station apparatus 10, that is, the period during which the road and vehicle transmission period can be set is the 16 road and vehicle transmission periods (3024 μs) shown in FIG.

  The in-vehicle terminal device 14 includes the transfer determination unit 56, but the portable terminal device 18 does not include the transfer determination unit 56. This is because the portable terminal device 18 does not transfer road-to-vehicle communication period information. Therefore, the extraction unit 86 in the portable terminal device 18 does not monitor the road-to-vehicle communication period in the IR control field of the received packet signal. As a result, the configuration becomes easy. However, time synchronization using the synchronization information in the IR control field and the transmission time is performed by the portable terminal device 18 in the same manner as the in-vehicle terminal device 14. The modem unit 74 and the RF unit 72 transmit packet signals during the vehicle transmission period of the frame. Here, the road-to-vehicle communication period in the IR control field stored in the received packet signal is not transferred.

  FIG. 12 shows the road-to-vehicle communication period information transfer operation by the portable terminal device 18. This is a case where road-to-vehicle communication period information of the portable terminal device 18 for one base station device 10 is transferred. For example, the base station apparatus 10 has a road-to-vehicle communication period length of 1 in the road-to-vehicle communication period information in FIG. 7, a transfer count of 1 (b7 is 0, b6 is 1), a road-to-vehicle communication period length of 3024 μs (b5 to b0 is 63). ) IR control field is transmitted. The portable terminal device 18 in the area 212 that has received it transfers the IR control field with the number of transfers of 0 (b7 is 0, b6 is 0) and the road-to-vehicle communication engine length is 0 μs (b5 to b0 is 0). .

  FIG. 13 shows the internal setting of the road-to-vehicle communication period in the portable terminal device 18. This shows the state of the internal setting of the road-to-vehicle communication period in the portable terminal device 18 that has received signals from the plurality of base station devices 10 and the plurality of other in-vehicle terminal devices 14. As in FIG. 9, four road-to-vehicle transmission periods of road-to-vehicle communication period 1, road-to-vehicle communication period 4, road-to-vehicle communication period 6, and road-to-vehicle communication period 9 among road-to-vehicle communication periods that can be set at 16 locations. Is set. The number of transfers in each road-to-vehicle communication period is 2, 2, 1, and 0. Each road-to-vehicle communication period length is 3024 μs, 3024 μs, 1440 μs, and 1920 μs.

  As described above, one subframe is obtained by dividing 100 ms by 16, but one subframe length is 6.24 ms except for the last 16th subframe, and only the 16th subframe is 6.40 m. It is defined as In the example of the in-vehicle terminal device 14 in FIG. 9, the road-to-vehicle communication period setting is used for the road-to-vehicle period corresponding to the set road-to-vehicle communication period length. On the other hand, in the case of the portable terminal device 18, the maximum period that can be set as the road-to-vehicle communication period is determined without depending on the received packet signal from the base station device 10, so that it is unique as shown in FIG. 13. Determined.

  On the portable terminal device 18 side, the NAV is set so that transmission is prohibited during the maximum period. Therefore, the transmission period of the portable terminal device 18 is 3.024 ms to 6.24 ms, 9.264 ms to 12.48 ms, 15.504 ms to 18.72 ms, 21.774 ms to 24.96 ms in a cycle of 100 ms. 27.984 ms to 31.20 ms, 34.224 ms to 37.44 ms, 40.464 ms to 43.68 ms, 46.704 ms to 49.92 ms, 52.944 ms to 56.16 ms, 59.184 ms to 62.40 ms, 65 .424 ms to 68.64 ms, 71.664 ms to 74.88 ms, 77.904 ms to 81.12 ms, 84.144 ms to 87.36 ms, 90.384 ms to 93.60 ms, 96.624 ms to 100.00 ms Is done.

  More specifically, a guard time of 64 μs is provided before and after this period length, and a packet signal transmission time equivalent is added to the NAV period before that. If the transmission time of the packet signal is 300 μs, the NAV setting during the control period of 100 ms is 0 ms to 3.088 ms, 5.876 ms to 9.328 ms, 12.116 ms to 15.568 ms, 18.356 ms to 21.808 ms. 24.596 ms to 28.048 ms, 30.83 ms to 34.288 ms, 37.076 ms to 40.528 ms, 43.316 ms to 46.768 ms, 49.556 ms to 53.008 ms, 55.796 ms to 59.248 ms, 62 0.036 ms to 65.488 ms, 68.276 m to 71.728 ms, 74.516 ms to 77.968 ms, 80.756 ms to 84.208 ms, 86.996 ms to 90.448 ms, 93.236 ms to 96.688 ms, 99.636 ms -99. The 99ms.

  Therefore, the transmission period is 3.088 ms to 5.8776 ms, 9.328 ms to 12.116 ms, 15.568 ms to 18.356 ms, 21.808 ms to 24.596 ms, 28.048 ms to 30.83 ms, with a period of 100 ms. 34.288 ms to 37.076 ms, 40.528 ms to 43.316 ms, 46.768 ms to 49.556 ms, 53.008 ms to 55.79 ms, 59.248 ms to 62.36 ms, 65.488 ms to 68.276 ms, 71. 728 ms to 74.516 ms, 77.968 ms to 80.756 ms, 84.208 ms to 86.996 ms, 90.448 ms to 93.236 ms, 96.688 ms to 99.636 ms.

  FIG. 14 shows the transfer setting for the road-to-vehicle communication period in the portable terminal device 18. Since the portable terminal device 18 does not transfer the road-to-vehicle communication period, the road-to-vehicle communication period length is set to all zero.

  According to the embodiment of the present invention, since the road-to-vehicle communication period information transmitted from the base station apparatus and the in-vehicle terminal apparatus is not transferred, the process for transferring can be omitted. Since the process for transferring is omitted, the amount of processing can be reduced. Since road-to-vehicle communication period information is not transferred, the monitoring function for road-to-vehicle communication period information can be reduced, and the amount of processing can be reduced. Moreover, since the vehicle transmission period other than the maximum period in which the road and vehicle transmission period can be set is automatically set, the monitoring process for the road-to-vehicle communication period information can be omitted. Since the amount of processing is reduced, power consumption can be reduced.

  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 each of those constituent elements or combinations of processing processes, and such modifications are also within the scope of the present invention. .

  In the embodiment of the present invention, the portable terminal device 18 does not transfer the road-to-vehicle communication period length. However, the present invention is not limited to this. For example, when the number of instructions set by the base station apparatus 10 is 2, the portable terminal apparatus 18 is configured so that the transfer is performed once. The number of transfers may be less than the number of transfers set by. That is, the portable terminal device 18 performs the transfer within the range of the transfer count smaller than the transfer count stored in the received packet signal. According to this modification, the number of transfers is reduced, so that the processing amount can be reduced.

  In the embodiment of the present invention, the portable terminal device (1) does not execute the transfer of the IR control field, and (2) sets the NAV for all settable road and vehicle transmission periods. However, the present invention is not limited to this. For example, the portable terminal device 18 may execute only one of (1) and (2). According to this modification, the processing amount can be reduced.

  The outline of one embodiment of the present invention is as follows. A portable terminal device according to an aspect of the present invention is a packet signal from a base station device in a road-to-vehicle transmission period among frames in which a road-to-vehicle transmission period and a vehicle-to-vehicle transmission period are time-division multiplexed, and A receiving unit that receives a packet signal in which period information relating to a road and vehicle transmission period is stored, and a transmission unit that transmits a packet signal in a vehicle and vehicle transmission period of the frame. The receiving unit receives the packet signal from the in-vehicle terminal device having a function for transferring the period information stored in the packet signal from the base station device in the vehicle transmission period of the frame, and the transmitting unit The period information stored in the packet signal received by the receiving unit is not transferred.

  According to this aspect, since the period information stored in the packet signal from the base station apparatus is not transferred, the processing amount can be reduced.

  The transmission unit may set a vehicle transmission period other than a period during which the road and vehicle transmission period can be set, regardless of whether the road and vehicle transmission period is actually set. In this case, a period other than the period in which the road and vehicle transmission period can be set is automatically set as the vehicle and vehicle transmission period, so that the monitoring process for the period information stored in the packet signal from the base station apparatus can be omitted.

  Another aspect of the present invention is also a portable terminal device. This device is a packet signal from a base station device in a road and vehicle transmission period of frames in which a road and vehicle transmission period and a vehicle and vehicle transmission period are time-division multiplexed. A receiving unit that receives a packet signal in which number-of-times information related to the number of times of period information transfer is stored, and a transmitting unit that transmits a packet signal during a vehicle transmission period of a frame. The transmission unit transfers the period information stored in the packet signal received by the reception unit within a range of the transfer number smaller than the transfer number indicated by the number of times information stored in the packet signal received by the reception unit.

  According to this aspect, since the period information stored in the received packet signal is transferred in the range of the transfer count smaller than the transfer count indicated by the count information stored in the packet signal, the processing amount can be reduced.

  Yet another embodiment of the present invention is also a portable terminal device. This device includes a receiving unit that receives a packet signal from a base station device in a road-vehicle transmission period in a road-vehicle transmission period and a vehicle-vehicle transmission period that are time-division multiplexed. A transmission unit that transmits the packet signal in the transmission period. The transmission unit sets the vehicle transmission period other than the period during which the road and vehicle transmission period can be set, regardless of whether the road and vehicle transmission period is actually set.

  According to this aspect, since the vehicle and vehicle transmission period is automatically set to a vehicle and vehicle transmission period other than the period in which the road and vehicle transmission period can be set, the monitoring process for the period information stored in the packet signal from the base station apparatus can be omitted.

  10 base station devices, 14 in-vehicle terminal devices, 18 portable terminal devices, 20 antennas, 22 RF units, 24 modulation / demodulation units, 26 processing units, 28 network communication units, 30 control units, 32 frame definition units, 34 selection units, 36 generation unit, 40 antenna, 42 RF unit, 44 modulation / demodulation unit, 46 processing unit, 48 control unit, 50 timing identification unit, 52 extraction unit, 54 carrier sense unit, 56 transfer determination unit, 58 acquisition unit, 60 notification unit, 62 generation unit, 70 antenna, 72 RF unit, 74 modulation / demodulation unit, 76 processing unit, 78 control unit, 80 acquisition unit, 82 generation unit, 84 timing identification unit, 86 extraction unit, 90 carrier sense unit, 92 pattern holding unit, 94 Notification unit, 100 Communication system.

Claims (3)

Of the frame in which the road and vehicle transmission period and the vehicle and vehicle transmission period are time-division multiplexed, in the road and vehicle transmission period, a packet signal that is a packet signal from the base station apparatus and stores period information on the road and vehicle transmission period A receiver for receiving the signal;
In the vehicle transmission period of the frame, a transmission unit that transmits a packet signal,
When the number of transfers stored in the packet signal from the base station apparatus has a transferable value in the vehicle transmission period of the frame, the receiving unit displays the period information stored in the packet signal. Receive the packet signal from the in-vehicle terminal device to be transferred ,
The transmitter is characterized in that the period information stored in the packet signal is not transferred even if the number of transfers stored in the packet signal received by the receiver is a transferable value. Terminal equipment.   2. The transmission unit sets a vehicle transmission period other than a period during which a road and vehicle transmission period can be set, regardless of whether or not a road and vehicle transmission period is actually set. The portable terminal device described in 1. Of the frame in which the road and vehicle transmission period and the vehicle and vehicle transmission period are time-division multiplexed, in the road and vehicle transmission period, a receiving unit that receives a packet signal from the base station device;
In the vehicle transmission period of the frame, a transmission unit that transmits a packet signal,
Regardless of whether or not the road and vehicle transmission period is actually set, the transmission unit sets NAV (Network Allocation Vector) for all of the frames in which the road and vehicle transmission period can be set. A portable terminal device that sets a vehicle-to-vehicle transmission period other than all the periods during which the road-to-vehicle transmission period can be set .

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