JP2009071688A - Communication gateway apparatus, on-vehicle network system, and gateway method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication gateway apparatus capable of reducing delay in transmission and reception of packet data irrespective of difference in the speed of packet data of each network or the like. <P>SOLUTION: The communication gateway apparatus 5 interconnects a plurality of networks having different protocols or the like and comprises: a plurality of protocol conversion processing parts 51 which input or output packet data to a corresponding network by a peculiar protocol, and output the packet data from the network by converting to intermediate packet data for which the protocol conversion processing part 51 of a destination network is specified based on a transmission destination address added to the packet data; a plurality of gateway processing parts 52 which perform a relay output of the intermediate packet data to a corresponding protocol conversion processing part 51; and a gateway selection part 53 for selecting a gateway processing part 52 which performs relay processing of the intermediate packet data. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a communication gateway device, a gateway method, and an in-vehicle network system including the communication gateway device that mutually connect a plurality of networks having different communication media or protocols.

  In recent years, electronic devices mounted on vehicles are increasing, and these electronic devices are connected to each other via a network to constitute an in-vehicle network system.

  In-vehicle network systems are increasingly composed of a plurality of communication networks. That is, each electronic device configures a network with a different communication method depending on each application. For example, control electronic devices such as engines and brakes configure a network with a CAN (Controller Area Network). Multimedia electronic devices such as navigation systems and audios form a network with MOST (Media Oriented Systems Transport).

  Furthermore, recently, it is required to connect not only between electronic devices mounted in the vehicle but also from an electronic device mounted in the vehicle to an external network such as the Internet via a mobile phone or the like. In addition, the diversification of communication methods is also progressing. As a result, an in-vehicle network system in which an electronic device mounted in a vehicle is connected to an external network by a wireless device is being proposed.

  In order to connect a plurality of networks, conventionally, as shown in FIG. 1, one communication gateway device having a function of converting a different protocol in each network is provided between two networks. In the case of the configuration shown in FIG. 1, in order to transmit / receive information (packet data) between the device M1 and the network N4 outside the vehicle via the wireless communication terminal G3, all the networks N1 to N3 and communication between the networks It is necessary to go through the gateway devices G1 and G2, and the transmission / reception delay of packet data is large.

  For example, in the case of a vehicle having a function to warn the driver of abnormalities around the vehicle with the surrounding monitoring sensor, when the motorcycle approaches in the blind spot of the driver, the surrounding monitoring sensor is operated and the approach of the motorcycle is detected from the speaker. However, if there is a large delay in packet data transmission / reception as described above, the warning to the driver may be delayed.

  As another example, if there is a notification of an accident of a preceding vehicle from a beacon installed in a roadside belt, etc., the driver will be warned and the seat belt will be wound up because the risk of collision and rear-end collision has improved. In the case of a vehicle having a function, if the packet data transmission / reception delay is large as in the above example, the time until the warning message is displayed to the driver after receiving the notification from the beacon, the seat belt There is a possibility that the time until the winding of the machine is delayed.

  In order to solve such a problem, as shown in FIG. 2, an in-vehicle network system that reduces a data transmission / reception delay between networks by providing one communication gateway device G4 between three or more networks. Has been proposed.

As such a communication gateway device, for example, Patent Document 1 discloses an in-vehicle gateway device for connecting a plurality of networks using different types of protocols, and packet data between devices on each network. A plurality of communication units provided between each network and the in-vehicle gateway device and the packet data transmission destination device corresponding to the packet data received from the transmission source device. Means for determining the destination of the received packet data with reference to the address table, means for converting the received packet data into a protocol related to the determined destination network, and on the network on which the converted packet data is determined Means for transmitting to the device, and can easily configure multiple networks. Vehicle gateway device has been proposed that.
JP 2003-309584 A

  However, because each network has a different communication method, the packet data communication speed is different, and because each application is different, the data amount of input / output packet data from each electronic device constituting each network is different. When packet data with high importance from a high-speed network is output to another network via a communication gateway device, it is necessary to wait for packet data from a network with a low communication speed to pass through the communication gateway device There is a possibility that the delay of transmission and reception of packet data may increase.

  In view of the above-described conventional problems, the object of the present invention is to provide packet data transmission between three or more networks regardless of the difference in packet data speed of each network or the difference in the amount of packet data transmitted and received. The object is to provide a communication gateway device, an in-vehicle network system, and a gateway method capable of reducing transmission / reception delay.

  In order to achieve the above-described object, a characteristic configuration of a communication gateway device according to the present invention is a communication gateway device that interconnects a plurality of networks having different protocols, and packet data is transmitted with a protocol unique to the corresponding network. In addition to input / output, the transmission packet data input from the network is converted into intermediate packet data that is specified by the protocol conversion processing unit of the transmission destination network based on the transmission destination address added to the transmission packet data, and is output. A plurality of protocol conversion processing units, a plurality of gateway processing units that relay output intermediate packet data output from each protocol conversion processing unit to a corresponding protocol conversion processing unit based on transmission / reception route information for the intermediate packet data, and each protocol From the conversion processor Certain force is intermediate packet data to that it includes a gateway selection unit for selecting a gateway processing unit for relaying process.

  According to the above-described configuration, the gateway selection unit outputs certain packet data to the destination network of the certain packet data via the certain gateway processing unit, and transmits other packet data to the relevant network via another gateway processing unit. By selecting a gateway processing unit that performs relay processing so that it is output to another destination network of packet data, it is possible to wait for packet data processing due to differences in the packet data speed of each network and the amount of packet data to be transmitted / received. To reduce delay in packet data transmission / reception.

  As described above, according to the present invention, packet data transmission / reception delay can be reduced between three or more networks regardless of the difference in the packet data speed of each network or the difference in the amount of packet data to be transmitted / received. It has become possible to provide a communication gateway device that can be reduced.

  Hereinafter, an embodiment in which a communication gateway device according to the present invention is applied to an in-vehicle network system will be described.

  As shown in FIG. 3, the in-vehicle network system includes a first communication network 2 that connects a plurality of vehicle control devices 22, a second communication network 3 that connects navigation devices 31 and audio devices 32, and a wireless communication interface. A third communication network 4 connected to a communication medium 42 outside the vehicle via 41 and a communication gateway device 5 according to the present invention connecting the communication networks 2, 3, 4 to each other are provided.

  The first communication network 2 is composed of a communication bus line based on a differential signal system in which a transmission line 21 transmits and receives data by transmitting signals having opposite phases to a pair of signal lines. This is a communication system in which electronic control units (hereinafter referred to as ECUs) 22 as a plurality of vehicle control devices 22 to be controlled communicate with each other via the communication bus line.

  As such a communication system, for example, there is a communication system based on a CAN (Controller Area Network) standard. Examples of the plurality of ECUs include an ECU that controls an engine, an ECU that controls a brake, an ECU that controls an automatic transmission, and an ECU that controls an electric power steering.

  In the second communication network 3, the transmission line 33 is composed of an optical fiber cable, and multimedia electronic devices such as a navigation device 31 and an audio device 32 such as a digital TV or a DVD player are mutually connected via the optical fiber cable. It is the communication system communicated to.

  As such a communication system, for example, there is a communication system based on the MOST (Media Oriented Systems Transport) standard. In the communication system based on the MOST (Media Oriented Systems Transport) standard, a plurality of electronic devices are connected to a ring-shaped optical fiber cable. Is done.

  The first communication network 2 and the second communication network 3 are connected to the communication gateway device 5 via the first communication interface 23 and the second communication interface 34, respectively. A transceiver having a function of checking a signal flowing through each of the communication networks 2 and 3 and the communication gateway device 5 and detecting a collision is provided.

  The third communication network 4 includes an existing communication infrastructure such as a wireless LAN, satellite communication, and a mobile phone line, and at least one of these via the wireless communication interface 41 allows communication with a communication medium 42 outside the vehicle. Packet data can be transmitted / received to / from devices inside the vehicle (ECU 22, navigation device 31, audio device 32, etc.).

  The wireless communication interface 41 is, for example, a portable information terminal device that implements a wireless communication function for accessing the above-described existing communication infrastructure. The portable information terminal device can be a USB (Universal Serial Bus) or a UART (Universal). It is connected to the communication gateway device 5 via an Asynchronous Receiver Transmitter). The portable information terminal device is specifically a mobile phone, a PDA, a notebook computer, or the like.

  In order to communicate with the communication medium 42 outside the vehicle, for example, in the case of a portable information terminal device that communicates via a wireless LAN, these portable information terminal devices are IrDA (Infrared Data Association) which is a standard for infrared communication. ), At least one wireless communication function such as Bluetooth used for short-range wireless communication and WiMAX (Worldwide Interoperability for Microwave Access), which is a standard for fixed wireless communication, is implemented via a mobile phone line. In the case of a portable information terminal device that performs communication, a wireless communication function of a method used for wireless communication such as a mobile phone such as code division multiple access (CDMA) is mounted.

  The communication medium 42 outside the vehicle is, for example, a mobile phone, a PDA, and a laptop computer connected to the communication gateway device 5, and other mobile phones, PDAs, personal computers, etc. that can transmit and receive packet data. In addition, it is a server or the like that provides a so-called telematic service that provides traffic information, weather forecasts, and the like to a moving body such as a vehicle using a mobile communication system.

  Information output from the communication networks 2 to 4 described above and information input to the communication networks 2 to 4 are transmitted and received by a packet method. That is, packet data including information about a transmission source device, information about a transmission destination device, information contents, and the like is transmitted and received.

  The communication gateway device 5 is configured to mutually connect a plurality of networks 2 to 4 having different protocols. The communication gateway device 5 inputs and outputs packet data with a specific protocol to the corresponding network and is input from the network. A plurality of protocol conversion processing units 51 (511) that convert the transmitted packet data into intermediate packet data that is specified by the protocol conversion processing unit 51 of the transmission destination network based on the transmission destination address added to the transmission packet data and output 513) and a plurality of gateway processing units 52 (521-52n) that relay output intermediate packet data output from each protocol conversion processing unit 51 to the corresponding protocol conversion processing unit 51 based on transmission / reception route information for the intermediate packet data. ) And each protocol conversion process The intermediate packet data output from unit 51 is provided with a gateway selection unit 53 for selecting a gateway processing unit 52 for relaying process.

  The protocol conversion processing unit 51, gateway processing unit 52, and gateway selection unit 53 reduce costs by maintaining a high processing speed and by manufacturing a plurality of protocol conversion processing units 51 and gateway processing units 52 having the same configuration. Therefore, it is constructed by an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

  FIG. 4 shows the packet data and various tables in each functional block and the packet data conversion process for the configuration and processing of the protocol conversion processing unit 51, gateway processing unit 52, and gateway selection unit 53. Based on

  Each of the plurality of protocol conversion processing units 51 converts packet data of a specific protocol received from the communication networks 2 to 4 to which the protocol conversion processing unit 51 is connected into intermediate packet data, and performs gateway processing via the gateway selection unit 53 Further, the intermediate packet data input from the communication gateway apparatus 5 is converted into the specific protocol and transmitted to the communication networks 2 to 4 to which it is connected.

  In order to perform such conversion quickly and accurately, for example, each protocol conversion processing unit 51 performs route information management that identifies the transmission source address, the transmission destination address, and the protocol conversion processing unit 51 of the network corresponding to the transmission destination address. A table 51A is provided.

  The route information management table 51A includes an identification symbol that identifies a source address such as an ID number and an IP address used in the corresponding communication networks 2 to 4, and a destination address such as an IP address and a boat number used in the gateway processing unit 52. And an identification symbol for identifying the protocol conversion processing unit 51 of the network corresponding to the transmission destination address are associated with each other and stored in a storage unit provided in the ASIC or FPGA.

  For example, the route information management table 51A corresponding to the first communication network 2 has an ID number (for example, the first number) added to the packet data when the packet data is transmitted to and received from the first communication network 2. When the network 2 is based on the CAN standard, an ID added to a data frame defined by CAN), an IP address added to the intermediate packet data when the gateway processing unit 52 relays the intermediate packet data, and The port number is associated with the port number.

  The route information management table corresponding to the third network 4 includes an IP address and a port number added to the packet data when the packet data is transmitted to and received from the third network 4, and the gateway processing unit 52. Thus, when the intermediate packet data is relayed, the IP address and the port number added to the intermediate packet data are associated with each other.

  Here, the IP address transmitted / received between the communication networks 2 to 4 indicates, for example, the type of the communication medium 42 outside the vehicle (for example, the type of medium such as a mobile phone or an Internet provider). The port number transmitted / received between ˜4 is, for example, any of the devices included in the type of the communication medium 42 outside the vehicle indicated by the IP address (for example, a plurality of providers that provide Internet providers) ID number transmitted / received between each of the communication networks 2 to 4 indicates, for example, any electronic device connected to the communication network 2 to 4.

  Then, each protocol conversion processing unit 51 performs route information management on packet data of a specific protocol received from the communication networks 2 to 4 to which the protocol conversion processing unit 51 is connected and intermediate packet data input from the communication gateway device 5. By searching the table, conversion is made between an ID number, an IP address, etc. included in the packet data of a specific protocol and an IP address, etc. included in the intermediate packet data.

  Each protocol conversion processing unit 51 includes a packet filter processing unit 51B that discards the packet data when address information such as an ID number or an IP address included in the received packet data does not exist in the route information management table. ing.

  In the route information management table 51A, combinations of identification symbols assumed when the communication networks 2 to 4 corresponding to the route information management table 51A transmit and receive packet data to and from other communication networks 2 to 4 are stored. .

  Therefore, each packet filter processing unit 51B searches the route information management table 51A, whether the packet data received by the protocol conversion processing unit 51 is data transmitted from an appropriate transmission source, and Then, it is determined whether or not an appropriate transmission destination is designated. If the destination is not appropriate, it is determined that the input packet data is abnormal packet data. With such a configuration, it is possible to prevent inappropriate data from entering the communication gateway device 5.

  As shown in FIG. 5, each gateway processing unit 52 (521 to 52 n) is connected between the communication networks 2 to 4 (between the first communication network 2 and the second communication network 3, the first communication network 2. Between the two communication networks 2 to 4 provided between the second communication network 4 and the third communication network 4, and between the second communication network 3 and the third communication network 4). Three relay parts 52B, 52C, and 52D for switching are provided.

  Further, as shown in FIG. 3, the gateway processing unit 52 is configured to refer to each gateway processing for reference when switching between connection and disconnection of the three relay units 52B, 52C, and 52D provided in each gateway processing unit 52. The unit 52 is provided with a common routing table 52A. Note that the routing table 52A is provided in the ASIC or FPGA by associating an identification symbol such as an ID number or IP address added to the input intermediate packet data with the types of the communication networks 2 to 4 as output destinations. Stored in the storage unit.

  The processing of the gateway processing unit 52 will be described in detail. Each of the plurality of gateway processing units 52 searches the routing table 52A for the ID number and IP address of the intermediate packet data input from each protocol conversion unit 51, and outputs the output destination. Communication networks 2 to 4 are determined, the relay units 52B, 52C and 52D provided between the output communication networks 2 to 4 are switched to the connected state, and the other communication networks 2 to 4 are connected. The relay units 52B, 52C, and 52D provided in are switched to the shut-off state.

  Each gateway processing unit 52, like each protocol conversion processing unit 51, is an intermediate unit that discards the intermediate packet data when address information such as an IP address included in the input intermediate packet data does not exist in the routing table. The structure provided with the packet filter process part may be sufficient.

  Based on the load state of each gateway processing unit 52, the gateway selection unit 53 selects the gateway processing unit 52 that relays the intermediate packet data output from each protocol conversion processing unit 51.

  This will be described in detail below. As illustrated in FIG. 6, the gateway selection unit 53 includes a priority setting unit 531 and a gateway switching control unit 532, and further includes an input switch 533, an output switch 534, a protocol conversion input buffer 535, and a protocol conversion output buffer 536. A plurality of gateway processing output buffers 537 and a plurality of gateway processing input buffers 538 are provided.

  More specifically, each protocol conversion input buffer 535 temporarily stores intermediate packet data input from each protocol conversion unit 51, and protocol conversion output buffer 536 outputs intermediate packet data to be output to each protocol conversion unit 51. The gateway processing output buffer 537 is composed of three buffers corresponding to the gateway processing units 521 to 523, respectively, and temporarily stores intermediate packet data to be output to the gateway processing units 521 to 523. The gateway processing input buffer 538 is composed of three buffers corresponding to the gateway processing units 521 to 523, respectively, and temporarily stores intermediate packet data input from the gateway processing units 521 to 523.

  The priority setting unit 531 refers to the three buffers a, d, and g connected to the gateway processing unit 521 among the gateway processing input buffers 538, and determines the degree of congestion as the load state of the gateway processing unit 521. Then, referring to the three buffers b, e, and h connected to the gateway processing unit 522 among the gateway processing input buffers 538, the degree of congestion of the gateway processing unit 522 is determined, and each gateway processing input buffer 538 The congestion degree of the gateway processing unit 523 is determined with reference to the three buffers c, f, i connected to the gateway processing unit 523.

  Specifically, the priority setting unit 531 includes a register that stores the number of addresses that are not currently used for each of the buffers a to i of the gateway processing input buffer 538, and refers to the registers a, d, and g. As the total or average of the values stored in these registers increases, the gateway processing unit 521 determines that the value is congested, and refers to the registers b, e, and h, and the total of the values stored in these registers. Alternatively, the gateway processing unit 522 determines that the gateway processing unit 522 is congested as the average increases, and the gateway processing unit 523 refers to the registers c, f, i to increase the sum or average of the values stored in these registers. Judged to be crowded.

  Then, the priority setting unit 531 uses the gateway processing units 521 to 523 that have determined that the intermediate packet data input from the protocol conversion unit 51 corresponding to the transmission source communication networks 2 to 4 is the least congested. It is determined that the data is relayed and output to the protocol conversion unit 51 corresponding to the destination communication networks 2 to 4, and information to that effect is output to the gateway switching control unit 532.

  The gateway switching control unit 532 performs switching control of the input switch 533 and the output switch 534 based on the determination by the priority setting unit 531.

  For example, when the gateway switching control unit 532 switches the output switch 534 and selects the three buffers a to c, the gateway switching control unit 532 receives information from the priority setting unit 531 that relay processing is performed using the gateway processing unit 521. The output switch 534 is switched to the buffer a. Further, when the gateway switching control unit 532 switches the input switch 533 to select the three buffers 1 to 3 and receives information from the priority setting unit 531 that relay processing is performed using the gateway processing unit 522, The input switch 533 is switched to the buffer 2.

  In addition, the gateway selection unit 53 includes a stack register that stores the switching status of each of the input switch 533 and the output switch 534 for each of the switches 533 and 534.

  For example, when the input switch 533 is switched to the buffer 2 when the input switch 533 is connected to the buffer 1 when the input switch 533 is connected to the buffer 1, the gateway switch control unit 532 uses the buffer before switching to the buffer 2. 1 is stored in the stack register. When the output of the intermediate packet data output to the gateway processing unit 522 via the buffer 2 is completed, the gateway switching control unit 532 refers to the stack register and switches the input switch 533 to the buffer 1.

  Then, the output of the intermediate packet data stored in the buffer 1 to the gateway processing unit 521 is resumed. At this time, the output of the intermediate packet data stored in the buffer 1 may be re-output from the beginning of the intermediate packet data, or only the intermediate packet data that was not output at the time of interruption is output. It may be configured to.

  In the above example, the example in which the input switch 533 is switched to the buffer 2 by the gateway switching control unit 532 while the input switch 533 is connected to the buffer 1 has been described, but after the switching to the buffer 2, the gateway switching control unit 532 further switches to the buffer 3. When the switching is performed, switching to the buffer 2 is performed after completion of the output of the intermediate packet data via the buffer 3, and switching to the buffer 1 is performed after the output of the intermediate packet data via the buffer 2 is completed.

  According to the above-described configuration, even when the amount of intermediate packet data being relay-processed by some of the gateway processing units 521 to 523 among the gateway processing units 521 to 523 is large, the gateway selection unit 53 performs the relay processing. Since another gateway processing unit 521 to 523 having a small amount of intermediate packet data in the middle is selected and relay processing is performed using the selected gateway processing unit 521, the waiting time for processing intermediate packet data is reduced, and intermediate processing is performed. Packet data transmission / reception delay can be reduced.

  Hereinafter, processing in the case of transmitting packet data from the first communication network 2 to the third communication network 4 via the communication gateway device 5 according to the present invention will be described based on the flowchart shown in FIG.

  When the protocol conversion unit 511 receives packet data from the first communication network 2 via the first communication interface 23 (S1), the protocol conversion unit 511 searches the route information management table 51A based on the ID number included in the packet data (S2). ).

  When the protocol conversion unit 511 finds the ID number in the route information management table 51A (S3), the protocol conversion unit 511 replaces the ID number with the IP address and port number corresponding to the ID number in the route information management table 51A. The packet data is converted into intermediate packet data (S4), and when the ID number is not found in the route information management table 51A (S3), the packet filter processing unit 51B discards the packet data (S14).

  When the intermediate packet data is output from the protocol conversion unit 511 to the gateway selection unit 53, the priority setting unit 531 refers to each of the buffers a to i to determine the congestion level of each gateway processing unit 52 (S5). The gateway processing unit 52 used for the relay process is selected (S6).

  When the intermediate packet data is output from the gateway selection unit 53 to the gateway processing unit 52 selected in step S6, the selected gateway processing unit 52 performs routing based on the IP address and port number included in the intermediate packet data. The table 52A is searched (S7).

  When the selected gateway processing unit 52 finds the IP address and port number in the routing table 52A (S8), the communication network 2 to 4 corresponding to the IP address and port number in the routing table 52A, that is, the book In the description, the third communication network 4 is determined as the output destination (S9), and when the IP address and port number are not found in the routing table 52A (S8), the intermediate packet filter processing unit is made to discard the intermediate packet data. (S14).

  When the intermediate packet data is output to the protocol conversion unit 513 that communicates with the third communication network 4 via the selected gateway processing unit 52, the protocol conversion unit 513 includes the IP address included in the intermediate packet data, The route information management table 51A is searched based on the port number (S10).

  When the protocol conversion unit 513 finds the IP address and port number in the route information management table 51A (S11), the protocol conversion unit 513 corresponds the IP address and port number to the IP address and port number in the route information management table 51A. When the intermediate packet data is converted into packet data corresponding to the protocol of the third communication network 4 by replacing with the IP address and port number (S12), and the IP address and port number are not found in the route information management table 51A In step S11, the packet filter processing unit 51B discards the intermediate packet data (S14).

  Then, the protocol conversion unit 513 transmits the packet data to the third communication network 4 via the third communication interface 41 (S13).

  As described above, the gateway method according to the present invention is a communication gateway method for connecting a plurality of networks 2, 3, 4 having different protocols to each other, and is executed by a plurality of protocol conversion processing units 51, respectively. The packet data is input / output with a protocol specific to the network, and the transmission packet data input from the network is converted into the protocol conversion processing unit 51 of the transmission destination network based on the transmission destination address added to the transmission packet data. The protocol conversion processing steps (steps S1 to S4 and S10 to S14 in FIG. 7) that are converted into the specified intermediate packet data and output, and the plurality of gateway processing units 52 are executed and output from each protocol conversion processing unit 51 Intermediate packet data into intermediate packet The gateway processing steps (steps S7 to S9 in FIG. 7) for relay output to the corresponding protocol conversion processing unit 51 based on the transmission / reception route information for the data, and the gateway selection unit 53, the load status of each gateway processing unit 52 And a gateway selection step (steps S5 and S6 in FIG. 7) for selecting the gateway processing unit 52 that executes the gateway processing step.

  Hereinafter, another embodiment will be described. In the above-described embodiment, the gateway selection unit 53 selects the gateway processing unit 52 that relays the intermediate packet data output from each protocol conversion processing unit 51 based on the load state of each gateway processing unit 52. Although described, it is not limited to such a configuration. Examples other than such a configuration will be described below.

  As a first embodiment, a priority order is set for each gateway processing unit 52 based on a destination address, a source address, or a combination of both, and the gateway selection unit 53 performs each protocol conversion process based on the priority order. The gateway processing unit 52 that relays the intermediate packet data output from the unit 51 may be selected.

  This will be described in detail below. An example in which priority order is set for each gateway processing unit 52 based on the transmission source address will be described. For the intermediate packet data input from the first communication network 2 to the communication gateway device 5, the priority of each gateway processing unit 52 is set. The ranks are set in the order of 521, 522, and 523 in order from the highest rank, and for the intermediate packet data input from the second communication network 3 to the communication gateway apparatus 5, the priority order of each gateway processing unit 52 is ranked. For the intermediate packet data set in the order of 522, 523, and 521 in order from the higher one, and input to the communication gateway device 5 from the third communication network 2, the priority order of each gateway processing unit 52 is set to the higher one. Set in order of 523, 521, and 522 in order from Storing the position of the set in the storage unit provided in the ASIC and the like constituting the gateway selection unit 53. The priority order set above is an example.

  And the gateway selection part 53 memorize | stores the communication networks 2-4 of a transmission source in a memory | storage part instead of judging the congestion degree of each gateway process part 521 with reference to the buffer ai of the gateway process output buffer 537. By comparing with the set priority order, it is determined which of the gateway processing units 521 is used for the relay processing.

  By setting in this way, for example, intermediate packet data input from the first communication network 2 is preferentially relayed by the gateway processing unit 521, and the gateway processing output buffer 537 stores the intermediate packet data as intermediate packet data. When the capacity is exceeded and processing is awaited, the intermediate packet data input thereafter is relayed by the gateway processing unit 522 of the next priority. The same processing is performed on the intermediate packet data input from the other communication networks 3 and 4 based on the respective priorities.

  In addition, when a priority is set for each gateway processing unit 52 based on a combination of a transmission destination address and a transmission source address, for example, table data including each combination and a priority order corresponding to each combination is stored. , And stored in a storage unit provided in the ASIC or the like constituting the gateway selection unit 53, the gateway selection unit 53 compares each of the transmission source and transmission destination communication networks 2 to 4 with the table data, Decide which gateway processing unit 521 to use for relay processing

  According to the above-described configuration, one gateway processing unit 52 is preferentially assigned to transmission / reception of packet data with a high degree of urgency such as vehicle engine speed data, and another gateway processing unit 52 is used for music voice data or the like. By setting priorities so that packet data with low urgency is preferentially assigned to transmission / reception of packet data, the state where packet data with high urgency is waiting for processing due to packet data with low urgency is reduced can do.

  As a second embodiment, priority is set for each gateway processing unit 52, an emergency transmission flag setting area is provided in the header of the packet data, and the gateway selection unit 53 sets the emergency transmission flag. The gateway processing unit 52 having a higher priority order for the packet data may be selected.

  For example, the priority order of each gateway processing unit 52 based on the urgency level of the packet data is set in the order of 521, 522, and 523 in order from the highest order, and the setting of these priority orders is performed by the gateway selection unit 53. The information is stored in a storage unit provided in the ASIC or the like constituting the device.

  By setting in this way, the packet data with a high urgency level in which the emergency transmission flag is set is preferentially used in the relay processing by the gateway processing unit 521 having a high priority, and the emergency transmission flag is set. Packet data with a low urgency level that is not used is preferentially used in the relay processing by the gateway processing unit 523 with a low priority.

  According to the above-described configuration, there is a high probability that packet data with high urgency and packet data with low urgency are different in the gateway processing unit 52 used in the relay process. It is possible to reduce the state of waiting for processing due to low packet data.

  In the above-described configuration, when the amount of packet data with high urgency is increased, the gateway processing unit 52 with a high priority may be waiting for processing. In such a case, the gateway selection unit 53 determines that the congestion level of the gateway processing unit 52 having a low priority is in advance based on the load state of each gateway processing unit 52 and the priority set in each gateway processing unit 52. The configuration may be such that the gateway processing unit 52 with the lower priority is used for the relay process as long as it is equal to or less than the set predetermined value.

  In the above-described embodiment, the gateway selection step of the gateway method according to the present invention is executed by the gateway selection unit 53, and the gateway processing unit 52 that executes the gateway processing step is selected based on the load state of each gateway processing unit 52. The gateway selection step is executed by the gateway selection unit 53, and the gateway processing unit 52 that executes the gateway processing step is selected based on the priority set in each gateway processing unit 52. It may be.

  In the above-described embodiment, a configuration has been described in which the packet filter processing unit 51B of each protocol conversion processing unit 51 discards the packet data when the address information included in the input packet data does not exist in the route information management table. However, the packet filter processing unit 51B discards the packet data not only when the address information does not exist in the route information management table.

  For example, the in-vehicle network system is configured to add authentication data indicating data attributes, communication priorities, and the like to packet data transmitted and received between the communication networks 2 to 4. Each protocol conversion processing unit 51, when receiving the packet data, checks whether the authentication data list stored in advance in its own storage unit matches the authentication data of the transmission source added to the received packet data. It may be configured to determine whether or not to discard the packet data by collating.

  In the above-mentioned embodiment, although the vehicle-mounted network system demonstrated the structure provided with the three communication networks 2-4, the number of communication networks is not restricted to three.

  In the above-described embodiment, the communication system based on the CAN standard, the communication system based on the MOST standard, and the existing communication infrastructure such as the wireless LAN have been described as the three communication networks 2 to 4. The communication network is not limited to the one exemplified in the above embodiment, and may be a communication system based on the LIN (Local Interconnect Network) standard, for example.

  In the above-described embodiment, the configuration in which the communication gateway device 5 according to the present invention is applied to an in-vehicle network system has been described. If it is a system which has the composition which performs, it may apply to a network system carried in not only a vehicle installation but an airplane, an air-conditioning system, etc., for example.

  Note that the above-described embodiment is merely an example of the present invention, and it is needless to say that the specific configuration and the like of each block can be changed and designed as appropriate within the scope of the effects of the present invention.

Functional block configuration diagram of a conventional in-vehicle network system in which a communication gateway device is provided between two networks Functional block configuration diagram of a conventional in-vehicle network system in which one communication gateway device is provided between three or more networks Functional block configuration diagram of a communication gateway device according to the present invention Explanatory drawing about packet data conversion process and configuration of route information management table and routing table Functional block diagram of gateway processing unit Functional block diagram of the gateway selector The flowchart for demonstrating the process which transmits packet data between each communication network via the communication gateway apparatus 5 by this invention.

Explanation of symbols

2: First communication network 3: Second communication network 4: Third communication network 5: Communication gateway device 51: Protocol conversion processing unit 51A: Route information management table 51B: Packet filter processing unit 52: Gateway processing unit 53 : Gateway selector

Claims (8)

A communication gateway device for connecting a plurality of networks with different protocols to each other,
Packet data is input to and output from the corresponding network using a unique protocol, and transmission packet data input from the network is converted to the destination network protocol based on the destination address added to the transmission packet data. A plurality of protocol conversion processing units that convert and output intermediate packet data that identifies
A plurality of gateway processing units that relay output intermediate packet data output from each protocol conversion processing unit to a corresponding protocol conversion processing unit based on transmission / reception route information for the intermediate packet data;
A communication gateway apparatus including a gateway selection unit that selects a gateway processing unit that relays intermediate packet data output from each protocol conversion processing unit.   2. The communication gateway device according to claim 1, wherein each protocol conversion processing unit includes a route information management table that specifies a protocol conversion processing unit of a network corresponding to a transmission source address, a transmission destination address, and a transmission destination address.   3. The communication gateway device according to claim 2, wherein each protocol conversion processing unit includes a packet filter processing unit that discards the packet data when address information included in the input packet data does not exist in the route information management table. .   The gateway selection unit according to any one of claims 1 to 3, wherein the gateway selection unit selects a gateway processing unit that relays intermediate packet data output from each protocol conversion processing unit based on a load state of each gateway processing unit. Communication gateway device.   A priority is set for each gateway processing unit based on a destination address, a source address, or a combination of both, and the gateway selection unit outputs intermediate packet data output from each protocol conversion processing unit based on the priority 4. The communication gateway device according to claim 1, wherein a gateway processing unit that performs relay processing is selected.   Priorities are set for each gateway processing unit, an emergency transmission flag setting area is provided in the header of the packet data, and the gateway selection unit has a priority for the packet data for which the emergency transmission flag is set. The communication gateway device according to claim 1, wherein a high gateway processing unit is selected.   A first communication network connecting a plurality of vehicle control devices, a second communication network connecting navigation devices and audio devices, and a third communication network connecting to a communication medium outside the vehicle via a wireless communication interface; An in-vehicle network system comprising the communication gateway device according to any one of claims 1 to 6, wherein the communication networks are connected to each other. A communication gateway method for connecting a plurality of networks having different protocols to each other,
A transmission destination that is executed by each of a plurality of protocol conversion processing units and inputs / outputs packet data with a specific protocol to the corresponding network, and the transmission packet data input from the network is added to the transmission packet data. A protocol conversion processing step for converting and outputting the intermediate packet data specifying the protocol conversion processing unit of the destination network based on the address;
A gateway processing step that is executed by a plurality of gateway processing units and relays the intermediate packet data output from each protocol conversion processing unit to a corresponding protocol conversion processing unit based on transmission / reception route information for the intermediate packet data;
A gateway comprising a gateway selection step that is executed by the gateway selection unit and selects a gateway processing unit that executes the gateway processing step based on a load state of each gateway processing unit or a priority set in each gateway processing unit Method.

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