JP2014089504A - Communication system, communication apparatus, communication processor, computer program and communication method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To discriminate several types of application data.SOLUTION: A communication system includes: a first communication apparatus 2 for transmitting application data in a periodically assigned transmission period; and a second communication apparatus 3 for receiving the application data transmitted from the first communication apparatus. The first communication apparatus 2 transmits the application data by adding additional information to each of the plurality of application data. The additional information includes data total number information of the application data, the data order information of the application data, and the data type information of the application data. The data total number information indicates the total number for each type of the application data. The data order information indicates the order for each type of the application data. The second communication apparatus 3 discriminates the plurality of application data on the basis of the additional information added to each of the plurality of application data.

Description

  The present invention relates to a communication system, a communication device, a communication processing device, a computer program, and a communication method.

In recent years, road-to-vehicle communication and intelligent road traffic system (ITS) by vehicle-to-vehicle communication have been studied. Road-to-vehicle communication is communication between a roadside communication device (base station) and an in-vehicle communication device (mobile station), and inter-vehicle communication is communication between in-vehicle communication devices (mobile stations).
Standards and guidelines have been established for such communication systems for intelligent transportation systems (see Non-Patent Documents 1 and 2).

  In Non-Patent Document 1, a maximum of 16 road-to-vehicle communication periods that arrive every predetermined transmission cycle (100 ms) are discretely provided, and a time zone other than the road-to-vehicle communication period is set as the vehicle-to-vehicle communication period.

Here, Non-Patent Document 2 defines an extended layer. The extension layer is interposed between the layer 7 defined in Non-Patent Document 1 and the application.
The enhancement layer of the roadside communication device (base station) on the transmission side adds an EL base station header to application data (EL-SDU; EL-Service Data Unit) given from the application.

The EL base station header includes data related information (DataAssociatedInformation) and a division number. The data related information is related information of application data, and includes data order information (DataSequence) and total data information (DataTotalNumber).
The data order information indicates the order of application data, and the total data information indicates the total number of application data.

The data related information including the data order information and the total number of data is given from the application to the enhancement layer as a transmission request (EL-BaseStationBroadcastData request) together with the application data.
The enhancement layer sets the data related information given from the application as the data related information of the EL base station header.

  The enhancement layer also has a function of dividing large-size application data into a plurality of pieces of divided data as necessary. When application data is divided, an EL base station header is added to each piece of divided data.

The division number stored in the EL base station header indicates division information of application data. The division number includes the order and the total number.
The order included in the division number is the order of data division, and the total number included in the division number is the total number of data divisions.

The Japan Radio Industry Association, "700MHz band Intelligent Transport System ARIB-STDT109 1.0 Edition", [online], February 14, 2012, [October 15, 2012 search], Internet <http: //www.arib.or.jp/tyosakenkyu/kikaku_tushin/tsushin_kikaku_number.html> ITS Information Communication System Promotion Conference, “700 MHz Band Intelligent Transport System Extended Function Guidelines ITS FORUM RC-010 1.0 Edition”, [online], March 26, 2012, [October 15, 2012 search], Internet <http://www.itsforum.gr.jp/>

Data related information (data order information and total number of data) included in the transmission request from the application is stored in the EL base station header. The division number is also stored in the EL base station header.
Therefore, the communication device (base station or mobile station) that has received the packet to which the EL base station header is added receives the data related information (data order information and the total number of data) included in the EL base station header, and the division number (order). And the total number).

  However, the present inventor has found that there is a case where a plurality of application data or a plurality of divided data cannot be appropriately distinguished and handled only by the information of the EL base station header defined in Non-Patent Document 2.

  That is, when it is intended to provide a plurality of types in the application data to be transmitted, only the information included in the EL base station header defined in Non-Patent Document 2 is used to appropriately distinguish the plurality of application data or the plurality of divided data. It cannot be handled.

For example, a situation is assumed in which a roadside communication device (base station) transmits six pieces of application data in a transmission period (road-to-vehicle communication period) allocated within one cycle (100 ms).
Of the six application data to be transmitted in the transmission period within one cycle, the first to third are application data of the first type, and the fourth to sixth are second data. It is assumed that this is application data of the type.
The types of application data include, for example, types depending on the service providers that provide application data, types based on data contents, destinations such as road-to-vehicle communication data and road-to-road communication data (moving to a base station) The type depending on the destination)

In the above situation (when division is not considered), the communication device (base station, mobile station) on the packet reception side is based on the data order information and the total number of data included in the data related information of the EL base station header, Consider differentiating application data contained in a packet.
In order to distinguish application data, it is conceivable to set data order information and total data information corresponding to each application data, for example, as in the following first setting example.
Non-Patent Document 2 does not define how to set the data order information and the total number of data.

[First setting example]
[Data order information / total data information] of the first application data = [1/6]
[Data order information / total data information] of the second application data = [2/6]
[Data order information / total data information] of the third application data = [3/6]
[Data order information / total data information] of the fourth application data = [4/6]
[Data order information / total data information] of the fifth application data = [5/6]
[Data order information / total data information] = [6/6] of the sixth application data

When set as in the first setting example, the six pieces of application data can be identified by the values 1 to 6 of the data order information.
Therefore, the communication device that has received the six pieces of application data can distinguish these six pieces of application data based on the data order information.

  However, based on [data order information / total data information], the receiving communication device can distinguish individual application data, but distinguishes which application data is which type of application data. It is not possible.

Moreover, in the first setting example, it is difficult for the receiving-side communication device to determine whether all application data is available for each type of application data.
That is, if the communication device on the receiving side can receive the application data having the [data order information / total data information] of [1/6] to [3/6] among the six pieces of application data, the other application data is Even if it cannot be received, all of the first type of application data is available.
Similarly, if the communication device on the receiving side can receive application data whose [data order information / total data information] is [4/6] to [6/6] among the six pieces of application data, the other application data Even if the application data cannot be received, all of the second type of application data is available.

However, whether or not application data is available is determined by comparing the number of received application data with the total data information.
In other words, if the total data information is “6”, it is determined that all the application data are available if the data order information can acquire six pieces of application data from “1” to “6”.
Therefore, even though the total data information is “6”, it is determined that the application data of [1/6] to [3/6] is prepared and the first type of application data is prepared, or [4 / 6] to [6/6] cannot be determined as the second type of application data being prepared.

As described above, the application data type cannot be distinguished and handled only by the data order information and the total data information defined in Non-Patent Document 2.
If the data order information and the total data information are set as in the first setting example, a problem arises in distinguishing and handling the types of application data.

  Moreover, when the application data is divided, only the information defined in Non-Patent Document 2 (data order information and total number of data, and the order and total number included in the division number) may cause a more complicated problem. .

  The present invention has been made in view of the above problems.

(1) According to one aspect of the present invention, a first communication device that transmits application data in a periodically assigned transmission period, and a second communication that receives the application data transmitted from the first communication device. And the first communication device adds additional information to each of a plurality of application data and transmits the data. The additional information includes data total number information indicating the total number of the application data, and the order of the application data. The data total number information indicates the total number of each type of the application data, and the data order information indicates the type of the application data. Showing the order of each, before the second communication device is transmitted from the first communication device Based on the additional information added to the plurality of application data, a communication system, characterized in that to distinguish between the plurality of application data.

  According to the communication system of the present invention, the data total number information and the data order information do not indicate the total number and order of the plurality of application data as in the first setting example, but are for each type of application data. Become. Therefore, the second communication device on the receiving side can easily determine whether application data is available for each type of application data.

Further, as in the present invention, when the total data information and the data order information are for each type of application data, a plurality of different types of application data may have the same [total data information and data order information]. .
However, in the present invention, data type information of application data is added to each application data. Therefore, even if a plurality of application data have the same [total data information and data order information], The second communication device can distinguish the application data based on the data type information.

(2) The first communication device includes a division processing unit that divides the application data, adds the additional information to each of a plurality of divided data generated by dividing the application data, and transmits the divided data. The additional information further includes division total number information indicating the total number of the plurality of divided data divided from one application data, and division order information indicating the order of each of the plurality of divided data divided from the one application data. The second communication device recognizes a combination of a plurality of divided data to be combined based on the additional information added to each of the plurality of divided data transmitted from the first communication device, and It is preferable to combine the divided data.

As described above, when the total data information and the data order information are for each type of application data, a plurality of different types of application data may have the same [total data information and data order information].
Therefore, when a plurality of application data having the same [total data number information and data order information] are all divided, a plurality of divided data having different data types have the same [total data number information and data order information, and divided Total number information and division order information]. In this case, the second communication device on the receiving side may erroneously recognize that it is a combination of a plurality of pieces of divided data to be combined with divided data having different data types.
On the other hand, when the data type is included in the additional information as in the present invention, there are a plurality of pieces of divided data having the same [total data number information and data order information, and total divided number information and division order information]. However, the second communication device on the receiving side can correctly recognize the combination of a plurality of divided data to be combined based on the data type included in the additional information.

(3) From another viewpoint, the present invention provides an application unit that generates a transmission request for application data, and a communication process for transmitting the application data requested to be transmitted from the application unit in a transmission period that is periodically assigned. The transmission request includes the application data and additional information, and the additional information includes data total number information indicating the total number of the application data, and data order information indicating the order of the application data; Data type information indicating the type of the application data, the total data information indicates the total number for each type of the application data, the data order information indicates the order for each type of the application data, The communication processing unit includes a plurality of applications. It is a communication device, characterized in that to transmit by adding the additional information to the respective application data.

According to the communication device, the additional information added to each of the plurality of application data includes the data type information of the application data.
Therefore, even if a plurality of application data have the same [total data information and data order information], the other communication device on the receiving side can distinguish the application data based on the data type information.
In addition, since the total data information and the data order information are for each type of application data, other communication devices on the receiving side can easily determine whether the application data is available for each type of application data. Can do.

(4) The present invention viewed from another viewpoint includes a communication processing unit and an application unit that receives a notification that the application data has been received from the communication processing unit, and each of the received plurality of application data includes: Additional information is added, and the additional information includes data total number information indicating the total number of the application data, data order information indicating the order of the application data, and data type information indicating the type of the application data. The data total number information indicates the total number for each type of the application data, the data order information indicates the order for each type of the application data, and the communication processing unit includes the application data and the notification in the notification Including the additional information, the notification is sent to the application. A communication device characterized in providing a.

According to the communication device, even when a plurality of application data has the same [total data information and data order information], the application data can be distinguished by the data type information included in the additional information.
Further, since the total data information and the data order information are for each type of application data, the communication device can easily determine whether application data is available for each type of application data.

(5) The present invention from another viewpoint is a communication processing device used in the communication device described in (3), in which an application unit that generates a transmission request for application data and a transmission request from the application unit are made. A communication processing unit that transmits the application data in a periodically assigned transmission period, and the transmission request includes the application data and additional information, and the additional information includes a total number of the application data. Data total number information indicating the order of the application data, and data type information indicating the type of the application data, the data total number information indicating the total number for each type of the application data , The data order information is the application Indicates the order of each type of chromatography data, the communication processing unit is a communication processing apparatus which comprises causing transmitted by adding the additional information to the plurality of application data.

(6) The present invention viewed from another viewpoint is a communication processing device used in the communication device according to (4), wherein the communication processing unit and a notification that application data has been received are received from the communication processing unit. Additional information is added to each of the received plurality of application data, and the additional information indicates data total number information indicating the total number of the application data and the order of the application data Data order information and data type information indicating the type of the application data, the total data information indicates the total number for each type of the application data, and the data order information is for each type of the application data The communication processing unit indicates the application data in the notification. Including fine the additional information, a communication processing device characterized by providing the notification to the application unit.

(7) From another viewpoint, the present invention includes a combination processing unit that combines the plurality of pieces of divided data received when the plurality of pieces of divided data obtained by dividing the application data are received, and each of the plurality of pieces of divided data received Is appended with additional information, and the additional information includes data total number information indicating the total number of application data, data order information indicating the order of the application data, and a plurality of pieces of data divided from one application data. Including the total number of pieces of division data indicating the total number of pieces of divided data, division order information indicating the order of a plurality of pieces of divided data divided from the one application data, and data type information indicating the type of the application data. The total number information indicates the total number for each type of the application data, and the data order The information indicates the order of each type of the application data, and the combination processing unit recognizes a combination of a plurality of divided data to be combined based on the additional information added to each of the received plurality of divided data. Thus, the communication processing apparatus is characterized by combining a plurality of divided data.

When the total data information and the data order information are for each type of application data, a plurality of different types of application data may have the same [total data information and data order information].
Therefore, when a plurality of application data having the same [total data number information and data order information] are all divided in the communication device on the transmission side, a plurality of divided data having different data types are identical to each other. Data order information, division total number information, and division order information]. In this case, the communication processing apparatus on the receiving side may erroneously recognize that it is a combination of a plurality of divided data to which divided data of different data types should be combined.
On the other hand, in the communication processing apparatus of the present invention, even if there are a plurality of pieces of divided data having the same [total data number information and data order information, divided total number information and divided order information], the data included in the additional information Based on the type, it is possible to correctly recognize a combination of a plurality of divided data to be combined.

(8) The present invention viewed from another viewpoint is a computer program for causing a computer to function as the communication processing device according to any one of (5) to (7).

(9) According to another aspect of the present invention, the first communication device transmits a plurality of application data in a transmission period periodically assigned to the first communication device, and the second communication device Receiving the plurality of application data transmitted from the first communication device, and performing processing by distinguishing each of the received plurality of application data, and additional information is added to each of the plurality of application data The additional information includes data total number information indicating the total number of the application data, data order information indicating the order of the application data, and data type information indicating the type of the application data. Indicates the total number of each type of the application data, the data order information, The order of each type of application data is shown, and in the processing by the second communication device, the received data is received based on the additional information added to each of the plurality of application data transmitted from the first communication device. A communication method characterized by distinguishing a plurality of application data.

It is a schematic perspective view which shows one Embodiment of an intelligent road traffic system. It is a block diagram of a roadside communication apparatus and a vehicle-mounted communication apparatus. (A) is a figure which shows a radio | wireless frame (super frame), (b) is a figure which shows the transmission period and transmission prohibition period in the radio | wireless frame of a roadside communication apparatus. It is a figure which shows the protocol stack of a communication apparatus. It is a figure which shows a packet structure. This is a packet transmission / reception sequence. It is a figure which shows the process of the extended layer on the transmission side, security management, and layer 7. It is explanatory drawing of EL-BaseStationBroadcastData primitive. It is a structural diagram of an EL base station header. It is a figure which shows the processing layer (comparative example) of the extended layer on the transmission side, security management, and layer 7. It is a figure which shows the setting value of the EL header in a comparative example. It is explanatory drawing of the problem which generate | occur | produces on the receiving side by the comparative example. It is a figure which shows the setting value of EL header in an Example. It is a flowchart which shows the process of the extended layer on the receiving side. It is a data structure figure of data related information.

[1. Communications system]
FIG. 1 is a schematic perspective view showing an overall configuration of an intelligent road traffic system (ITS) according to an embodiment of the present invention. In this embodiment, as an example of the road structure, a grid structure in which a plurality of roads in the north-south direction and the east-west direction intersect with each other is assumed.
As shown in FIG. 1, the intelligent transportation system of this embodiment includes a traffic signal 1, a roadside communication device (base station) 2, an in-vehicle communication device (mobile station) 3 (see FIG. 2), a central device 4, and in-vehicle communication. A vehicle 5 on which the machine 3 is mounted, and a roadside sensor 6 including a vehicle detector, a monitoring camera, and the like are included. As a mobile station, it is not restricted to the vehicle-mounted communication apparatus 3, For example, the communication apparatus for pedestrians which a pedestrian possesses may be sufficient.
Note that points that are not particularly described in the present embodiment are based on Non-Patent Documents 1 and 2.

Traffic signal machine 1 and roadside communication machine 2 (2A, 2B) are installed in each of a plurality of intersections A1-A5, B1-B5, C1-C5, D1-D5, E1-E5. Some roadside communication devices 2A among the plurality of roadside communication devices 2 are connected to the router 8 via a wired communication line 7 such as a telephone line. This router 8 is connected to the central device 4 in the traffic control center. The plurality of roadside communication devices 2 include a roadside communication device 2 </ b> B that is not connected to the router 8.
The central device 4 constitutes a local area network (LAN) with the traffic signal device 1 and the roadside communication device 2 in the area that the central device 4 has jurisdiction over. The central device 4 may be installed on the road instead of the traffic control center.

The roadside communication device 2A (online roadside communication device) connected to the central device 4 via the wired communication line 7 is a part of all roadside communication devices included in the area controlled by the central device 4, and the central device There is also a roadside communication device 2 </ b> B (stand-alone roadside communication device) that is not connected to 4 by a wired communication line 7.
In FIG. 1, the roadside communication device 2A installed at the intersections A1 to A5 is an online roadside communication device, and the roadside communication devices installed at the other intersections B1 to B5, C1 to C5, D1 to D5, and E1 to E5. 2B is a stand-alone roadside communication device. Thus, the installation / maintenance cost of the wired communication line 7 can be reduced by not using all roadside communication devices as online roadside communication devices.
In the case where the online roadside communication device 2A and the stand-alone roadside communication device 2B are not distinguished, they are referred to as “roadside communication device 2”.

The roadside sensor 6 is installed in various places on the road in the jurisdiction area for the purpose of counting the number of vehicles flowing into each intersection. The roadside sensor 6 is composed of a vehicle sensor for ultrasonically sensing the vehicle 5 passing underneath, or a monitoring camera for photographing road traffic conditions in time series, and the sensing information and image data are transmitted via the communication line 7. To the central device 4.
In FIG. 1, for simplification of illustration, only one signal lamp is depicted at each intersection. However, at each actual intersection, at least four signal lamps are used for ascending and descending roads that intersect each other. Is installed.

In an intelligent road traffic system, a plurality of roadside communication devices (base stations; communication devices) 2 installed at a plurality of intersections constituting a wireless communication system are in-vehicle communication devices (mobile stations; mobile stations) of vehicles traveling around the roadside communication devices. Wireless communication (road-to-vehicle communication) is possible with the communication device 3.
Each roadside communication device 2 is also capable of wireless communication (inter-road communication) with other roadside communication devices 2 that are located within a predetermined range within which their transmission waves reach.
An in-vehicle communication device (mobile station) 3 that also constitutes a wireless communication system performs wireless communication with the roadside communication device 2 and also wirelessly communicates with other in-vehicle communication devices 3 (vehicle-to-vehicle communication) using a carrier sense method. Is possible.

As shown in FIG. 2A, the online roadside communication device (base station) 2A includes a wireless communication unit (RF unit; PHY unit) 21 to which an antenna 20 for wireless communication is connected, and a wired communication line 7. And a communication processing device 25 for performing communication control processing.
The communication processing device 25 includes a control unit 23 and a storage unit 24 that stores necessary information. The control unit 23 performs communication control processing for wireless communication and wired communication. The storage unit 24 stores information necessary for wireless communication and wired communication.

  A part or all of the functions of the communication processing device 25 may be configured by a hardware circuit, or a part or all of the functions may be realized by a computer program. When some or all of the functions of the communication processing device 25 are realized by a computer program, the communication processing device 25 (control unit 23) includes a computer, and the computer program executed by the computer is stored in the storage unit 24. The

  As shown in FIG. 2B, the stand-alone roadside communication device (base station) 2B corresponds to a device in which the wired communication unit 22 is omitted from the online roadside communication device 2A.

The in-vehicle communication device (mobile station) 3 includes a wireless communication unit (RF unit; PHY unit; receiving unit) 31 to which an antenna 30 for wireless communication is connected, and a communication processing device 35 that performs communication control processing. ing.
A part or all of the functions of the communication processing device 35 of the in-vehicle communication device 3 may be configured by a hardware circuit, or a part or all of the functions may be realized by a computer program. . When a part or all of the functions of the communication processing device 35 are realized by a computer program, the communication processing device 35 (control unit 33) includes a computer, and the computer program executed by the computer is stored in the storage unit 34. The

FIG. 3A shows a radio frame (super frame) used in the radio communication system. This radio frame is set to have a length (frame length) in the time axis direction of 100 ms. That is, 10 frames are generated per second.
The radio frame is generated based on, for example, 1 PPS (signal with a period of 1 second) included in a GPS signal received by a GPS receiver (not shown) included in the roadside communication device 2.

One radio frame (100 ms) includes a plurality of road-to-vehicle communication periods SL1 and a plurality of vehicle-to-vehicle communication periods SL2.
The road-to-vehicle communication period SL1 is a time slot for road-to-vehicle communication assigned to the roadside communication device 2 (transmission period for roadside communication device), and wireless transmission by the roadside communication device 2 is allowed in this time zone SL1. . Up to 16 road-to-vehicle communication periods SL1 can be set in one radio frame (100 ms).

  The inter-vehicle communication period SL2 is a time slot (vehicle communication period) for the in-vehicle communication device 3, and this time zone SL2 is released as a radio transmission time by the CSMA method by the in-vehicle communication device 3, so that the roadside communication device 2 Wireless transmission is not performed in the inter-vehicle communication period SL2.

The road-to-vehicle communication period SL1 and the vehicle-to-vehicle communication period SL2 included in the wireless frame are alternately arranged in the time axis direction.
Slot numbers n (= 1 to 16) are assigned to the road-to-vehicle communication period SL1.

In each roadside communication device 2, one or a plurality of road-to-vehicle communication periods SL1 among a plurality of road-to-vehicle communication periods SL1 included in the radio frame is set as a transmission period, and the other road-to-vehicle communication periods SL1 are Transmission is prohibited. That is, for the roadside communication device 2, the vehicle-to-vehicle communication period SL2 and the road-to-vehicle communication period SL1 not assigned to the own device 2 are transmission prohibited periods.
FIG. 3B shows a transmission prohibition period when three road-to-vehicle communication periods SL1 of n = 4, 5, and 6 are assigned to the roadside communication device 2 as transmission periods. The roadside communication device 2 performs data transmission in a period (transmission period) other than the transmission prohibition period. The transmission period shown in FIG. 3B occurs periodically (every 100 ms). That is, the roadside communication device 2 can transmit a communication packet in a transmission period that is periodically assigned every 100 ms.

  The number of transmission periods allocated to one roadside communication device 2 in one radio frame is arbitrary. Further, the period length of one transmission period may be equal to the period length of the road-vehicle communication period or may be shorter than the road-vehicle communication period. A plurality of transmission periods may be set within one road-vehicle communication period SL1.

[2. Protocol stack]
FIG. 4 shows a communication protocol stack shown in the standard of Non-Patent Document 1 plus an extended layer EL shown in the guidelines of Non-Patent Document 2.

  The protocol stack defined in Non-Patent Document 1 includes Layer 1 (L1, Physical Layer), Layer 2 (L2, Data Link Layer), Inter-Vehicle / Road-Vehicle Shared Communication Control Information Layer (IVC). -RVC layer: Inter-Vehicle Communication-Road to Vehicle Communication Layer) and Layer 7 (L7, Application Layer: Application Layer). Each layer and application AP can access system management with information for system management.

Layer 1 operates in accordance with a physical layer defined in IEEE 802.11.
Layer 2 includes a MAC sublayer (Medium Access Control sublayer) and an LLC sublayer (Logical Link Control sublayer). The MAC sublayer is also simply referred to as a MAC layer (Medium Access Control layer), and the LLC sublayer (Logical Link Control sublayer) is also simply referred to as an LLC layer (Logical Link Control layer).

The MAC layer performs frame control and broadcast communication (broadcast) as wireless channel communication management. The MAC layer of the roadside communication device 2 performs a process of transmitting a communication packet in the transmission period assigned to the own device 2.
The LLC layer provides a connectionless communication service without confirmation in order to perform packet transmission between higher-layer entities.

  The inter-vehicle / road-vehicle shared communication control information layer (IVC-RVC layer) generates and manages information necessary for inter-vehicle / road-vehicle shared communication control. In Non-Patent Document 1, road-to-road communication is not defined, so when performing road-to-road communication in the road-to-vehicle communication period SL1 as in this embodiment, the inter-vehicle / road-to-vehicle shared communication control information layer (IVC -RVC layer), road-to-road communication is handled as a kind of road-to-vehicle communication.

  Layer 7 is for providing communication control means to the application AP. The application AP gives the application data (traffic information, vehicle information, etc.) stored in the transmitted communication packet to the layer 7 and acquires the application data stored in the received communication packet from the layer 7.

The enhancement layer EL defined in Non-Patent Document 2 exists as an upper layer of the layer 7, and is for extending the communication function between the application AP and the layer 7.
The enhancement layer EL provides a data transmission service to the application AP. The application AP gives a transmission request (EL-BaseStationBroadcastData request or EL-MobileStationBroadcastData request) including application data (traffic information, vehicle information, etc.) stored in the transmitted communication packet to the enhancement layer EL. In order to provide a data transmission service, the enhancement layer EL issues a data transmission request (BaseStationBroadcast request or MobileStationBroadcastData request) to a lower layer below layer 7.

Further, the enhancement layer EL can divide the application data given from the application AP and give the divided data to the layer 7. That is, the enhancement layer EL functions as a division processing unit 51 that divides application data and generates a plurality of pieces of divided data.
Further, the divided data received from the layer 7 can be combined and given to the application AP. That is, the enhancement layer EL also functions as a combination processing unit 52 that combines the divided data.
The extension layer EL can access the security management SEC together with the layer 7.

  Functions corresponding to the extension layer EL, layer 7, IVC-RVC layer, layer 2, application AP, security management SEC, and system management shown in FIG. 4 are the functions of the communication processing device 25 of the roadside communication device 2 and the in-vehicle communication device 3. It is executed by each communication processing device 35. Further, the layer 1 function is executed by the wireless communication unit 21 of the roadside communication device 2 and the wireless communication unit 31 of the in-vehicle communication device 3.

In the communication processing device 25, a function corresponding to the application AP in FIG. 4 is referred to as an “application unit 25a”, and functions lower than the application AP in FIG. 4 (extended layer EL, layer 7, IVC-RVC layer). , Layer 2, security management SEC, and system management) are referred to as “communication processing unit 25b”.
Also, in the communication processing device 35, the function corresponding to the application AP of FIG. 4 is referred to as “application device 35a”, and functions lower than the application AP of FIG. 4 (extended layer EL, layer 7, IVC-RVC layer). , Layer 2, security management SEC, and system management) are referred to as “communication processing unit 35b”.

  The functions of the application units 25a and 35a can be realized by a computer program, and the functions of the communication processing units 25b and 35b can be configured by hardware. Further, the functions of the communication processing units 25b and 35b may be realized by a computer program.

  The application AP (application units 25a and 35a) of the present embodiment has a plurality of applications AP1 and AP2. In FIG. 4, a first application AP1 and a second application AP2 are shown as a plurality of applications.

  The first application AP1 and the second application AP2 correspond to, for example, differences in service providers that provide application data. For example, the first application AP1 is an application for providing a service by a first service provider, and the second application AP2 is an application for providing a service by a second service provider.

  Further, the first application AP1 and the second application AP2, for example, the first application AP1 may correspond to a difference in content of provided data. For example, the first application AP1 is an application for providing traffic information, and the second application AP2 is an application for providing safe driving support information.

  Furthermore, the first application AP1 and the second application AP2 may correspond to, for example, differences in communication forms. For example, the first application AP1 is an application for providing road-to-vehicle communication data, and the second application AP2 is an application for providing road-to-road communication data.

  Each of the applications AP1 and AP2 outputs information (data type information) indicating different data types when making a transmission request.

[3. Communication packet and communication sequence]
FIG. 5 shows a configuration of communication packets transmitted by the roadside communication device 2 and the in-vehicle communication device 3. The configuration of the communication packet shown in FIG. 5 conforms to Non-Patent Documents 1 and 2 except for the security header and the security footer.
Data transmitted in road-to-vehicle communication, road-to-road communication, and vehicle-to-vehicle communication are all transmitted in the form of communication packets shown in FIG.

The communication packet has a PHY header (physical header) at the head. The PHY header is placed before the MAC frame (MPDU; MAC Protocol Data Unit) acquired from the MAC layer by layer 1 (physical layer) of the communication devices 2 and 3 (roadside communication device 2 or in-vehicle communication device 3) on the transmission side. Added.
The PHY header is read in layer 1 (physical layer) in the communication devices 2 and 3 on the reception side and used for communication control processing in layer 1 on the reception side. Note that the entire communication packet including the PHY header is a PPDU (PHY Protocol Data Unit). The MAC frame (MPDU) on the rear side of the PHY header is also a PSDU (PHY Service Data Unit).

  The configuration of the PHY header conforms to IEEE 802.11. Therefore, the PHY header includes a preamble and the like.

Subsequent to the PHY header, a MAC control field (MAC header) and an LLC control field (LLC header) are provided. The MAC control field is added before the LLC frame (LPDU; LLC Protocol Data Unit) acquired from the LLC layer by the MAC layer of the layer 2 of the communication devices 2 and 3 on the transmission side.
The MAC control field is read by the MAC layer of the layer 2 of the communication devices 2 and 3 on the reception side and used for communication control processing in the MAC layer on the reception side.
The LLC frame (LPDU) on the rear side of the MAC control field is also an MSDU (MAC Service Data Unit).

The LLC control field following the MAC control field is added in front of the IR frame (IPDU; IVC-RVC Protocol Data Unit) acquired from the IVC-RVC layer by the LLC layer of the layer 2 of the transmitters 2 and 3 on the transmission side. The
The LLC control field is read by the LLC layer of the layer 2 of the communication devices 2 and 3 on the reception side, and used for communication control processing in the LLC layer on the reception side.
The IR frame (IPDU) on the rear side of the LLC control field is also an LSDU (LLC Service Data Unit).

Following the LLC control field, an IR control field (IR header) is provided. The IR control field is added before the AP frame (APDU; Application Protocol Data Unit) by the IVC-RVC layer of the communication devices 2 and 3 on the transmission side.
The IR control field is read in the IVC-RVC layer of the receiving side communication devices 2 and 3 and used for the communication control processing in the receiving side IVC-RVC layer.
An AP frame (APDU; Application Protocol Data Unit) behind the IR control field is also an ISDU (IVC-RVC Service Data Unit).

Following the IR control field, an L7 header is provided. The L7 header is added before the ASDU (Application Service Data Unit) by the layer 7 of the communication devices 2 and 3 on the transmission side.
The L7 header is read by the layer 7 of the receiving side communication devices 2 and 3 and used for communication control processing in the receiving side layer 7.
An EL frame (EL-PDU; EL-Protocol Data Unit) behind the layer 7 header is also an ASDU (Application Service Data Unit).

Subsequent to the L7 header, an EL header (EL base station header) is provided. The EL header is added before EL-SDU (EL-Service Data Unit) by the enhancement layer EL of the communication devices 2 and 3 on the transmission side.
The EL header is read by the enhancement layer EL of the reception side communication devices 2 and 3 and used for processing in the reception side enhancement layer EL.

  EL-SDU is a security header and application data. And a security footer. The application data is given from the application AP to the communication processing units 25b and 35b.

The application data is read by the application AP of the receiving side communication devices 2 and 3 and used for processing in the receiving side application AP.
The application AP can generate data to be transmitted, read the received data and use it for its own processing, or retransmit (transfer) the received data.

  As shown in FIG. 6, when the communication device on the transmission side is the base station 2, the application AP on the transmission side expands the transmission request for application data APData (see FIG. 7A) as an EL-BaseStationBroadcastData request. Output to layer EL. The EL-BaseStationBroadcastData request includes application data and other information (described later).

When receiving the application data from the application AP included in the transmission request, the transmission-side enhancement layer EL causes the security management SEC to execute security processing as necessary (Security request in FIG. 6).
The security management (security processing unit) SEC on the transmission side performs security processing on the unsecured application data received from the enhancement layer EL to generate secure application data. Further, the security management SEC adds a security header and a security footer before and after the application data (see FIG. 7B).

In security management SEC, processing (security processing) for converting unsecured application data to secure application data includes processing such as encryption processing and signature processing (however, it is defined in Non-Patent Documents 1 and 2). Absent).
The security management returns the secure application data subjected to the security processing to the enhancement layer EL (Security response in FIG. 6).

When the application data (EL-SDU) is larger than a predetermined size, the transmission-side enhancement layer EL (the division processing unit 51) divides the application data (EL-SDU) into a plurality of divisions equal to or smaller than the predetermined size. The data is divided (division processing in FIG. 6; see FIG. 7C). FIG. 7C shows a state where the application data (EL-SDU) returned from the security management SEC is divided into two.
When the data is divided, an EL header (EL base station header / EL mobile station header) is added as additional information to each divided data. That is, an EL header is added to each of the two pieces of divided data shown in FIG. 7C, and two EL-PDUs are generated.

As shown in FIG. 6, the transmission-side enhancement layer EL generates a BaseStationBroadcastData request for each EL-PDU as a transmission request to the layer 7. The BaseStationBroadcastData request includes EL-PDU (ASDU) and other information.
As shown in FIG. 7D, the transmission side layer 7 adds an L7 header to each EL-PDU (ASDU) to generate an APDU.
Subsequently, a layer lower than layer 7 on the transmission side sequentially performs processing, and transmits a communication packet in a transmission period periodically allocated (100 ms).

  Then, when receiving the APDU from the lower layer, the layer 7 of the receiving side communication devices 2 and 3 causes the enhancement layer EL to receive the ASDU (EL-PDU) included in the APDU as shown in FIG. BaseBaseBroadcastData display is generated and given to the enhancement layer EL.

  When receiving the divided data as the EL-PDU, the reception-side enhancement layer EL (the combination processing unit 52) combines the EL-PDU excluding the EL header (additional information) (divided data), and EL -Generate an SDU (joining process in FIG. 6).

When the EL-SDU is secure application data, the reception-side enhancement layer EL passes the secure application data (EL-SDU) to the security management SEC (Unsecurity request in FIG. 6). The security management SEC performs unsecurity processing (decoding processing) on the secure application data and returns it to unsecure application data (EL-SDU) (Unsecurity response in FIG. 6).
When the enhancement layer EL receives the unsecured application data (EL-SDU) from the security management SEC, the enhancement layer EL generates the reception notification to pass the unsecured application data (EL-SDU) to the application AP.

  The enhancement layer EL generates an EL-BaseStationBroadcastData display as an application data (EL-SDU) reception notification and provides it to the application AP. The EL-BaseStationBroadcastData display includes application data (EL-SDU) and other information (described later).

FIG. 8A shows information included in the EL-BaseStationBroadcastData request and EL-BaseStationBroadcastData display defined in Non-Patent Document 2.
As shown in FIG. 8A, the EL-BaseStationBroadcastData request and the EL-BaseStationBroadcastData display specified in Non-Patent Document 2 each include application-related data (ApplicationData) and data-related information (DataAssociatedInformation). Yes.
On the other hand, in the present embodiment, as shown in FIG. 8B, the EL-BaseStationBroadcastData request and the EL-BaseStationBroadcastData display include, in addition to application data (ApplicationData) and data-related information (DataAssociatedInformation), respectively, Information (EL-DataClassification) is additionally included. The data type information may be simply referred to as “data type”.

  In addition to application data (ApplicationData), data-related information (DataAssociatedInformation), and data type, the EL-BaseStationBroadcastData request and EL-BaseStationBroadcastData display of EL-BaseStationBroadcastData in this embodiment are described in Non-Patent Document 2, respectively. Information defined as information included in the display is included as it is.

  As described above, the data-related information is transmitted between the application AP and the enhancement layer EL in a transmission request or a reception notification. As shown in FIG. 8C, the data related information includes a base station ID (BaseStationID), a data order (DataSequence), and a total number of data (DataTotalNumber).

The base station ID is ID information for identifying the base station (roadside communication device 2).
The data order is information (data order information) indicating the order of application data.
The total number of data is information indicating the total number of application data (total data information).

The data type is information (data type information) indicating the type of application data.
The data type information is, for example, 4-bit information as shown in FIG. In this case, 16 types of applications can be classified.

In FIG. 8D, in order to distinguish the application data of the four services of the road-to-vehicle communication data provided by the first application AP1 (“road car 1” in FIG. 8D), four values of b0000-b0011 are used. Is assigned.
In addition, four values of b0100 to b0111 are assigned to distinguish application data of four services of road-to-vehicle communication data provided by the second application AP2 (“road car 2” in FIG. 8D). .

Furthermore, in order to distinguish the application data of the four services of the first road-to-road communication data provided by the first application AP1 (“road 1” in FIG. 8D), four values of b1000-b1011 are set. Assigned.
Furthermore, in order to distinguish the application data of the four services of the second road-to-road communication data provided by the second application AP2 ("Route 2" in FIG. 8D), four values b1100 to b1111 are used. Is assigned.
Note that the method of setting the data type is not limited to that shown in FIG.

FIG. 9 shows how to set the EL base station header (additional information) and how to read the EL base station header by the enhancement layer EL of the present embodiment.
As shown in FIG. 9, the EL base station header (additional information) of the present embodiment includes a “version” field, an “EL header type” field, an “EL security classification information” field, a “data related information” field, and a “division” It has a “number” field and a “data type” field.

The “version” field is a field indicating protocol version information of the enhancement layer EL.
The “EL header type” field is information indicating information for distinguishing the EL base station header from the EL mobile station header. When the transmitting side is a base station, the EL header is an EL base station header, and when the transmitting side is a mobile station, the EL header is an EL mobile station header.
The “EL security classification information” field is a field indicating whether or not access to the security management SEC (unsecurity processing) is necessary.

  The “data related information” field has the same data structure as the “data related information” included in the EL-BaseStationBroadcastData request. That is, the “data related information” field includes fields of “base station ID”, “data order”, and “total number of data”.

The “partition number” field has an “order” field and a “total number” field.
Information indicating the order of data division (division order information) is stored in the “order” field.
The “total number of divisions” field stores information indicating the total number of data divisions (total number of divisions).
The fields other than the “data type” field are defined in Non-Patent Document 2. The “data type” field in FIG. 9 uses what is reserved as the “reservation” field in Non-Patent Document 2.

In this embodiment, when the transmission-side enhancement layer EL receives a transmission request (EL-BaseStationBroadcastData request) from the application AP, the data-related information and the data type (data type information) included in the transmission request are displayed in the EL base. Set in the “data related information” field and “data type” field of the station header.
Further, in the present embodiment, the transmission-side enhancement layer EL indicates the order and total number of each of the plurality of pieces of divided data divided from one application data in accordance with the data division performed in the enhancement layer EL. It is set in the “order” field and “total number” field of the “division information” field of the station header.
For example, when one application data is divided into two, the [order / total number] of the EL base station header added to the first divided data is set to [1/2]. The [order / total number] of the EL base station header added to the divided data is set to [2/2].
When application data is not divided, [order / total number] of the EL base station header added to the application data is set to [1/1].

Further, when receiving the EL-PDU from the layer 7, the receiving-side enhancement layer EL extracts the EL base station header from the EL-PDU.
The reception-side enhancement layer EL sets the data-related information and data type included in the EL base station header as the data-related information and data type in the reception notification (EL-BaseStationBroadcastData display) to the application AP.

[4. Processing example]
[4.1 Comparative Example]
10 to 12 show processing examples as comparative examples. The comparative example shows a processing example when the “data type” shown in FIG. 9 is omitted from the EL base station header, that is, a processing example when only non-patent documents 1 and 2 are compliant.
In the comparative example, since the data type is omitted, only the data related information and the division number are information that the enhancement layer EL on the receiving side distinguishes the data (EL-PDU).

  In FIG. 10, an application AP of a certain base station 2 (base station ID = N) has six pieces of application data RV1-1 to RV1-3 as application data to be transmitted in a transmission period within one superframe. Assume that each RV2-1 to 2-3 transmission request is given to the enhancement layer EL.

The six application data items include three application data RV1-1, RV1-2, and RV1-3 output from the first application AP1, and three application data RV2-1 output from the second application AP2. , RV2-2, and RV2-3.
The three application data RV1-1, RV1-2, RV1-3 output from the first application AP1, and the three application data RV2-1, RV2-2, RV2 output from the second application AP2. -3 is different in data type.

  In FIG. 10, application data RV1-1 and RV2-1 are each divided into two pieces of divided data, and a total of eight EL-PDU transmission requests are made from the enhancement layer EL to the layer 7. Shall.

In Non-Patent Documents 1 and 2, it is not considered at all that the application AP includes a plurality of applications AP1 and AP2 and that application data having different data types is output from the application AP.
Then, regarding the six pieces of application data RV1-1 to RV1-3 and RV2-1 to 2-3 shown in FIG. 10, if the difference between the applications AP1 and AP2 that output the application data and the difference in data type are not considered, Simply, six pieces of application data are given from the application AP to the enhancement layer EL.

In this case, as the application AP, [data order information / total data information] of the data related information of the transmission request (EL-BaseStationBroadcastData request) of each of the six application data
Similar to the first setting example described above, it is natural to set as follows.

[First setting example in comparative example]
[Data Order Information / Total Data Information] = [1/6] of application data RV1-1
[Data order information / total data information] of application data RV1-2 = [2/6]
[Data Order Information / Total Data Information] = [3/6] of Application Data RV1-3
[Data order information / total data information] of application data RV2-1 = [4/6]
[Data order information / total data information] of application data RV2-2 = [5/6]
[Data Order Information / Total Data Information] = [6/6] of application data RV2-3

  With this setting, the total number of data is 6 in the enhancement layer EL on the receiving side, and it can be recognized that the values of 1 to 6 are set as the data order for each of the six application data. Individual application data can be distinguished. However, Non-Patent Documents 1 and 2 do not describe such a setting method.

In the enhancement layer EL on the receiving side, the individual application data can be distinguished and recognized, so that the divided data can be combined.
In other words, if [data order information / data total number information] is set so that individual application data can be distinguished and recognized, a plurality of divided data (EL-PDU) divided from one application data are respectively It has the same data related information (base station ID / data order information / total data information).
Therefore, the reception-side enhancement layer EL can recognize that the combination of EL-PDUs to be combined is an EL-PDU group having the same base station ID / data order information / total data information.

However, if importance is placed on distinguishing the six pieces of application data individually in [data order information / total data information] as described above, as described in [Problems to be Solved by the Invention], the type of application data is as follows. It is impossible to determine whether or not data is available every time.
That is, in the above setting example, since the total data information is “6”, it can be determined that all the applications are prepared if the six pieces of application data are prepared, but [1/6] to [3/6]. In a state where the application data RV1-1 to RV1-3 of the first application AP1 are prepared in a state where the application data is prepared, or in a state where the application data of [4/6] to [6/6] are prepared, It cannot be determined that the application data RV2-1 to RV2-3 of the second application AP2 are prepared.

  Therefore, the six application data RV1-1 to RV1-3 and RV2 shown in FIG. 10 are determined so that the extension layer EL or the application AP can determine whether or not the data is prepared for each type of application data. [Data order information / total data information] for each of −1 to 2-3 is set as follows.

[Second setting example in comparative example]
[Data Order Information / Total Data Information] = [1/3] of Application Data RV1-1
[Data order information / total data information] of application data RV1-2 = [2/3]
[Data order information / total data information] of application data RV1-3 = [3/3]
[Data Order Information / Total Data Information] = [1/3] of Application Data RV2-1
[Data Order Information / Total Data Information] of application data RV2-2 = [2/3]
Application data RV2-3 [data order information / data total number information] = [3/3]

  In this case, the data related information and division number of the EL base station header included in each of the eight EL-PDUs shown in FIG. 10 are as shown in FIG.

In [Second Setting Example in Comparative Example] and FIG. 11, [Data Order Information / Total Data Information] indicates the data order and the total number of data for each data type of application data.
That is, only the three first-type application data RV1-1, RV1-2, and RV1-3 output from the first application AP1 are considered, and the three application data RV1-1 are considered in consideration of the data order and the total number of data. , RV1-2, RV1-3, [data order information / total data information] = [1/3] to [3/3] are set.
Similarly, only the three second-type application data RV2-1, RV2-2, and RV2-3 output from the second application AP2 are considered, and the three application data in consideration of the data order and the total number of data. [Data Order Information / Total Data Information] = [1/3] to [3/3] is set in each of RV2-1, RV2-2, and RV2-3.

  In this way, by setting the data order and the total number of data for each type of application data, it is possible to determine whether the data is prepared for each type of application data in the extension layer EL or application AP on the receiving side. It becomes like this.

However, a plurality of pieces of data having the same [data order information / total number of data information] (for example, two pieces of RV1-1 and RV2-1 in FIG. 11) may be generated, and application data may not be properly distinguished from each other.
For example, if the EL base station header is set as shown in FIG. 11, a new problem as shown in FIG. 12 occurs.

  In FIG. 12, among the eight packets (EL-PDU) shown in FIG. 10, the division number [order / total number] = [2/2] of application data RV1-1 and the application data RV2-1 It is assumed that the divided data of the division number [order / total number] = [1/2] cannot be received by radio on the receiving side communication devices 2 and 3 due to a failure in the propagation path or the like.

In this case, when the data related information is set as shown in FIG. 11, the application data RV1-1 and RV2-1 have the same data related information (base station ID / data order information / total data information). Become.
Therefore, the enhancement layer EL on the receiving side splits the division number [order / total number] = [1/2] of the division number [EL-PDU] of the application data RV1-1 and the division number [order / The divided data (EL-PDU) of [total number] = [2/2] is erroneously recognized as a combination of EL-PDUs to be combined.
As a result, as shown in FIG. 12, the receiving-side enhancement layer EL combines the data obtained by removing the EL header from each of these incorrect combinations of EL-PDUs, and performs unsecurity processing (decoding processing) on the security management SEC. Will be required.

  However, the security management SEC that has received the wrong combination of combined data cannot correctly perform the unsecurity processing. For this reason, the receiving-side enhancement layer EL and application AP acquire a decoding error as an Unsecurity response (decoding response) from the security management SEC, and obtain original application data RV1-1 and RV2-1. Can not.

  Further, the same data related information (base station ID / data order information) is also applied to the application data RV1-2, RV1-3, RV2-2, and RV2-3 that can be received by radio waves in the communication devices 2 and 3 on the receiving side. / Data total number information) is the data RV2-2, RV2-, which are the data RV1-2, RV1-3 received earlier in the storage unit 24 of the communication devices 2, 3 on the receiving side. By overwriting with 3, the previously received data RV1-2 and RV1-3 may be substantially discarded.

  For this reason, in the example shown in FIG. 12, the enhancement layer EL and the application AP can eventually acquire only two pieces of application data RV2-2 and RV2-3.

[4.2 Examples]
13 and 14 show an embodiment. The EL base station header shown in FIG. 13 has a data type in addition to the data related information and the division number, similarly to the EL base medical station header shown in FIG.

In FIG. 13, the data related information is set in the same way as [Second Setting Example in Comparative Example] and FIG. 11, and whether or not data is prepared for each type of application data in the extension layer EL or application AP. Can be judged.
In FIG. 13, only the application data RV1-1 is divided into two. Therefore, FIG. 13 shows seven EL-PDUs, one less than in FIG.

  In FIG. 13, the division number (order / total number) is set in the same manner as in FIG. 11 except that the application data RV2-1 is not divided and is 1/1.

  In FIG. 13, different values are set as data types for application data RV1-1 to RV1-3 and application data RV2-1 to 2-3. Therefore, the reception-side enhancement layer EL can determine that the application data RV1-1 to RV1-3 and the application data RV2-1 to 2-3 are different in data type based on the data type.

  As shown in FIG. 14, the reception-side enhancement layer EL receives data-related information (base station ID, data order, total number of data), division number (order, total number), from the EL base station header of the acquired EL-PDU. The data type is acquired (step S1).

The enhancement layer EL considers the data type in addition to the data-related information and the division number, and the divided data (EL-PDU) having the same data-related information and the data type is combined with a plurality of divided data ( (EL-PDU) combination, and the divided data are combined (step S2). For this reason, as shown in FIG. 12, it is possible to prevent a wrong combination.
That is, in the example shown in FIG. 13, two divided data divided from the application data RV1-1 can be correctly combined.

The application data RV1-2 and RV2-2 have the same data-related information but have different data types, so that the receiving-side enhancement layer EL can be distinguished as different data.
Similarly, the application data RV1-3 and RV2-3 have the same data-related information but have different data types, so that the extension layer EL on the receiving side can be distinguished as different data.
As a result, overwrite discard as shown in FIG. 12 is prevented.

  As described above, the reception-side enhancement layer EL can distinguish and process each of the six pieces of application data RV1-1 to RV1-3 and RV2-1 to RV2-3.

  Then, the reception-side enhancement layer EL has data-related information and data types in the reception notification (EL-BaseStationBroadcastData display) for each of the six pieces of application data RV1-1 to RV1-3 and RV2-1 to RV2-3. The data related information and data type set in the EL base station header are set, and the reception notification is passed to the application AP (step S3).

  In the application AP, the data type included in the reception notification is determined, and whether the application data included in the reception notification is to be processed by the first application AP1 or the second application AP2. Can be easily determined.

[5. Modified example]
FIG. 15A shows data related information included in the EL base station header defined in Non-Patent Document 2.
FIG. 15B shows data related information included in the EL base station header according to the modification.

  In Non-Patent Document 2, as shown in FIG. 15A, the “base station ID” field of the data related information is 6 bits (from the 12th bit to the 17th bit). On the other hand, in the modification shown in FIG. 15B, the “base station ID” field has 4 bits (from the 14th bit to the 17th bit) in 6 bits that are the “base station ID” field in Non-Patent Document 2. Is used). The remaining 2 bits (13th and 12th bits) are fields for data type (data type information).

The transmission-side enhancement layer EL sets the data type included in the transmission request in the “data type” field shown in FIG.
The enhancement layer EL on the receiving side distinguishes data with reference to the data type shown in FIG. Further, the reception-side enhancement layer EL sets the data type shown in FIG. 15B to the “data type” of the reception notification.

  If the structure of the data related information shown in FIG. 15B is adopted, the data type can be stored in the “data related information” field. Therefore, as shown in FIG. There is no need to secure a separate field.

  Further, in Non-Patent Document 2, a part of the area constituting the “base station ID” field is used as a “data type” field as shown in FIG. Even if the communication devices 2 and 3 are premised on being defined as shown in FIG. 4, it is possible to distinguish and process data of different data types.

The enhancement layer EL of the communication devices 2 and 3 assuming that the data-related information is defined as shown in FIG. 15A acquires the EL-PDU having the data-related information shown in FIG. Then, the base station ID and the data type shown in FIG.
That is, on the receiving side, even if communication packets are transmitted from the same base station, it is recognized that the base station IDs are different due to different data types.
As a result,
Even in the communication devices 2 and 3 on the assumption that the data-related information is defined as shown in FIG. 15A, it is assumed that data of different data types are transmitted from different base stations. , Can be handled distinctly.

[6. Addendum]
With respect to the present invention, the embodiments disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is not meant to be described above, but is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

1 Traffic signal 2 Roadside communication equipment (base station)
3 In-vehicle communication device (mobile station)
4 Central device 5 Vehicle 6 Roadside sensor 7 Wired communication line 21 Wireless communication unit 22 Wired communication unit 23 Control unit 24 Storage unit 25 Communication processing device 25a Application unit 25b Communication processing unit 31 Wireless communication unit 33 Control unit 34 Storage unit 35 Communication processing Device 25b Application unit 35b Communication processing unit 51 Division processing unit 52 Join processing unit AP Application EL Enhancement layer L7 Layer 7

Claims (9)

A first communication device that transmits application data in a periodically assigned transmission period;
A second communication device that receives the application data transmitted from the first communication device,
The first communication device transmits additional information to each of a plurality of application data,
The additional information is
Data total number information indicating the total number of the application data;
Data order information indicating the order of the application data;
Data type information indicating the type of the application data;
Including
The data total number information indicates the total number of each type of the application data,
The data order information indicates an order for each type of the application data,
The second communication device distinguishes the plurality of application data based on the additional information added to each of the plurality of application data transmitted from the first communication device. The first communication device includes a division processing unit that divides the application data, adds the additional information to each of a plurality of divided data generated by dividing the application data, and transmits the divided data.
The additional information is
Division total number information indicating the total number of a plurality of divided data divided from one application data;
Division order information indicating the order of each of a plurality of pieces of divided data divided from the one application data;
Further including
The second communication device recognizes a combination of a plurality of divided data to be combined based on the additional information added to each of the plurality of divided data transmitted from the first communication device, and a plurality of divided data The communication system according to claim 1. An application part that generates a transmission request for application data;
A communication processing unit that transmits the application data requested to be transmitted from the application unit in a periodically assigned transmission period;
With
The transmission request includes the application data and additional information,
The additional information is
Data total number information indicating the total number of the application data;
Data order information indicating the order of the application data;
Data type information indicating the type of the application data;
Including
The data total number information indicates the total number of each type of the application data,
The data order information indicates an order for each type of the application data,
The communication processing unit adds the additional information to each of a plurality of application data to be transmitted. A communication processing unit;
An application unit that receives notification from the communication processing unit that application data has been received;
With
Additional information is added to each of the received application data.
The additional information is
Data total number information indicating the total number of the application data;
Data order information indicating the order of the application data;
Data type information indicating the type of the application data;
Including
The data total number information indicates the total number of each type of the application data,
The data order information indicates an order for each type of the application data,
The communication processing unit includes the application data and the additional information in the notification, and gives the notification to the application unit. A communication processing device used in the communication device according to claim 3,
An application part that generates a transmission request for application data;
A communication processing unit that transmits the application data requested to be transmitted from the application unit in a periodically assigned transmission period;
With
The transmission request includes the application data and additional information,
The additional information is
Data total number information indicating the total number of the application data;
Data order information indicating the order of the application data;
Data type information indicating the type of the application data;
Including
The data total number information indicates the total number of each type of the application data,
The data order information indicates an order for each type of the application data,
The communication processing apparatus, wherein the communication processing unit adds the additional information to each of a plurality of application data to be transmitted. A communication processing device used in the communication device according to claim 4,
A communication processing unit;
An application unit that receives notification from the communication processing unit that application data has been received;
And
Additional information is added to each of the received application data.
The additional information is
Data total number information indicating the total number of the application data;
Data order information indicating the order of the application data;
Data type information indicating the type of the application data;
Including
The data total number information indicates the total number of each type of the application data,
The data order information indicates an order for each type of the application data,
The communication processing unit includes the application data and the additional information in the notification, and gives the notification to the application unit. When receiving a plurality of pieces of divided data obtained by dividing application data, a combination processing unit for combining the plurality of pieces of divided data received,
Additional information is added to each of the plurality of divided data received,
The additional information is
Data total number information indicating the total number of the application data;
Data order information indicating the order of the application data;
Division total number information indicating the total number of a plurality of divided data divided from one application data;
Division order information indicating the order of a plurality of pieces of divided data divided from the one application data;
Data type information indicating the type of the application data;
Including
The data total number information indicates the total number of each type of the application data,
The data order information indicates an order for each type of the application data,
The combining processing unit recognizes a combination of a plurality of divided data to be combined based on the additional information added to each of the received plurality of divided data, and combines the plurality of divided data. Communication processing device.   The computer program for functioning a computer as the said communication processing apparatus of any one of Claims 5-7. The first communication device transmits a plurality of application data in a transmission period periodically assigned to the first communication device,
A second communication device receiving the plurality of application data transmitted from the first communication device, and performing processing by distinguishing each of the received plurality of application data;
Additional information is added to each of the plurality of application data,
The additional information is
Data total number information indicating the total number of the application data;
Data order information indicating the order of the application data;
Data type information indicating the type of the application data;
Including
The data total number information indicates the total number of each type of the application data,
The data order information indicates an order for each type of the application data,
In the processing by the second communication device, the received plurality of application data is distinguished based on the additional information added to each of the plurality of application data transmitted from the first communication device. Communication method.

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