JP5469028B2 - Communications system - Google Patents

Description

  The present invention relates to a communication system including a mesh network having a plurality of communication nodes.

  Conventionally, in communication between devices, data is transmitted and received by directly connecting a terminal (communication node) as a transmission source and a communication node as a reception destination. In this case, there is an advantage that it is easy to understand because it is possible to secure a route for performing the desired communication by directly connecting the communication node and the communication node.

  However, when the number of communication partners increases, the number of connections required for communication between communication nodes becomes necessary. Therefore, for example, when it is necessary to communicate with all the communication nodes, there is a problem that the connection becomes complicated.

  As one method of solving such a problem, for example, as a wireless LAN access point, any one communication node is set as a base point (base point node), and the communication node relays each communication. There is a method for enabling communication nodes to communicate with each other.

  In the case of the method using the base point node, since the base point node relays communication of all the communication nodes, the communication is concentrated, so that the load on the base point node becomes very large. Therefore, a mesh network has been devised in which any one communication node does not undertake communication relay, but all communication nodes can serve as relay stations (see, for example, Patent Documents 1 and 2).

  FIG. 13 shows an example of a mesh network. The mesh network 100 illustrated in FIG. 13 includes nodes (communication nodes) A to E. Node A is connected to node B so that they can communicate with each other. Node B is connected to nodes A, C, and D so that they can communicate with each other. Node C is connected to nodes B and E so that they can communicate with each other. Node D is connected to nodes B and E so that they can communicate with each other. Node E is connected to nodes C and D so that they can communicate with each other.

  In a mesh network, when data is transmitted to a target communication node in communication, data is transmitted to a nearby communication node even if it cannot be directly transmitted. Then, the communication node to which the data has been transmitted further transmits the data to neighboring communication nodes. By repeating this, data can be transmitted to the target communication node. For example, in the mesh network 100 shown in FIG. 13, when data is transmitted from the node A to the node E, the data is transmitted from the node A to the node B, and then the data is transmitted from the node B to the node C. The data is transmitted from the node C to the node E. Alternatively, data may be transmitted from the node B to the node E through the node D. Since data is transmitted in this way, the load of data relay is not concentrated on one communication node, and communication can be efficiently performed as a whole.

  In such a mesh network, in order to deliver data to a target communication node, each communication node selects a route so that the number of relays is as small as possible. Therefore, it is possible to reduce unnecessary relays and efficiently use the network as the entire communication network.

  In a conventional mesh network, for example, as in Patent Document 3, it is common to configure each communication node to select a route with as few relay points as possible.

  However, in a mesh network, since the number of relays differs depending on each communication node, data generated later than data generated earlier in time may reach the receiving communication node earlier. For example, in the case of FIG. 13, when data (referred to as data D) occurs at node D after data (referred to as data A) generated at node A, data A and data D are generated in the order in which the data occurred. However, the data D may reach the node E first.

  In this case, since the order of arrival data is changed, when processing must be performed in the order of data generation, for example, the node E (or the entire network) needs to manage the order of data generation. For example, FIG. 13 is a network relating to vehicle window control, where node A is a window open / close lock button, node D is a window open / close button, and node E is a device that operates a window. If the window opening / closing is operated after the window opening / closing lock button is operated and locked, the window is not opened / closed correctly. However, as described above, the data D, that is, the window opening / closing button If the data indicating the above operation reaches the node E first, it leads to a malfunction in which the window operates despite being locked when viewed as the entire vehicle window.

  As described above, when the mesh network is applied in a control system application, there is a first problem that the influence of the data arrival order problem due to the difference in the number of relays is increased.

  In order to solve such problems, the applicant has proposed a communication system in which the transmission timing of data is adjusted at the transmission source and all data is transmitted to the destination node over the same time. According to this communication system, the subsequent data does not arrive earlier than the previous data, and the application does not need to manage the order of arrival of the data, and can have a simple configuration.

  However, in the communication system described above, there is a pattern that cannot be realized unless each node allows simultaneous transmission and reception. This pattern will be described using the mesh network 100 of FIG. 13 as an example. This mesh network 100 has a maximum number of hops of three. Each of the nodes A to E has a destination, a presence / absence of a relay station when transmitting to the destination, and a relay station as a table for determining a route to the destination, as shown in FIGS. A table indicating the number of hops to the next relay station and destination is stored.

  First, the operation of the mesh network 100 when data is transmitted from the node D to the node C and from the node A to the node C will be described with reference to FIG.

  At time t1, communication data 54 is generated at node D. As shown in FIG. 2, the node D creates a communication frame 50 in which transmission source information 51 = node D, destination information 52 = node C, and hop number 53 = 0 are added to the communication data 54. Next, the node D refers to the table of the node D shown in FIG. 7 and confirms that the relay station is the node B with the remaining two hops to the destination node C.

  Since the number of hops 53 of the communication frame 50 is 0, it can be seen that there are 2 hops in total up to the node C. This is different from the maximum number of hops 3 in the mesh network 100. Therefore, the node D adds 1 to the hop number 53 of the communication frame 50 and transmits the communication frame 50 to itself without transferring data to the node B of the relay station. At this time, since the communication is the communication frame 50 addressed to itself, the communication frame 50 is actually processed without transmitting the communication frame 50 using the communication path (node D → node D).

  At time t2, the node D confirms the destination of the communication frame 50 received from the node D itself. In this case, since the destination of the communication frame 50 is not the own node D, the table shown in FIG. 7 is referred again. Here, it can be seen that the destination node C is the remaining 2 hops and the relay station is the node B. Since the current number of hops is 1, it can be seen that there are a total of 3 hops up to node C. This is the same as the maximum number of hops 3 in the mesh network 100, and the node D passes the communication frame 50 to the node B that is a relay station. At this time, 1 is added to the number of hops of the communication frame 50, and the communication frame 50 is passed to the node B (node D → node B).

  At time t2, communication data 54 is generated at node A. As shown in FIG. 4, the node A creates a communication frame 50 in which transmission source information 51 = node A, destination information 52 = node C, and hop number 53 = 0 are added to the communication data 54. Next, the node A refers to the table of the node A shown in FIG. 4 and confirms that the relay station is the node B with the remaining two hops to the destination node C. Since the number of hops 53 of the communication frame 50 is 0, it can be seen that there are 2 hops in total up to the node C. This is different from the maximum number of hops 3 in the mesh network 100. Therefore, the node A adds 1 to the hop number 53 of the communication frame 50 without transmitting it to the node B of the relay station, and transmits the communication frame 50 to itself. At this time, since the communication is the communication frame 50 addressed to itself, the communication frame 50 is actually processed without transmitting the communication frame 50 using the communication path (node A → node A).

  At time t3, the node B confirms the destination of the communication frame 50 received by the node D. In this case, since the destination is not addressed to the own node B, the table of the own node B shown in FIG. 5 is referred to. Here, it can be seen that the destination node C has one hop remaining and no relay station. That is, node C is a node adjacent to node B. Since the current number of hops is 2, it can be seen that there are a total of 3 hops up to node C. This is the same as the maximum number of hops 3 in the mesh network 100, and the node B passes the communication frame 50 to the destination node C. At this time, the hop number 53 of the communication frame 50 is incremented by 1, and the communication frame 50 is passed to the node C (node B → node C).

  At time t3, the node A confirms the destination of the communication frame 50 received by the own node A. In this case, since the destination is not addressed to the own node A, the table of the own node A shown in FIG. 4 is referred to. Here, it can be seen that the destination node C is the remaining 2 hops and the relay station is the node B. Since the number of hops of the communication frame 50 is 1, it can be seen that there are a total of 3 hops up to the node C. This is the same as the maximum number of hops 3 in the mesh network 100, and the node A passes the communication frame 50 to the node B which is a relay station. At this time, the hop number 53 of the communication frame 50 is incremented by 1, and the communication frame 50 is passed to the node B (node A → node B).

  At time t4, the node C confirms the destination of the communication frame 50 received by the node B. In this case, the destination is the own node C. Also, since the number of hops stored in the communication frame 50 is 3, it can be seen that the communication frame 50 has been normally communicated, and the Node B delivers the communication data 54 in the communication frame 50 to the application. .

  At time t4, the node B confirms the destination of the communication frame 50 received by the node A. In this case, since the destination is not addressed to the own node A, the table of the own node B shown in FIG. 5 is referred to. Here, it can be seen that the destination node C has one hop remaining and no relay station. That is, node C is a node adjacent to node B. Since the current number of hops is 2, it can be seen that there are a total of 3 hops up to node C. This is the same as the maximum number of hops 3 in the mesh network 100, and the node B passes the communication frame 50 to the destination node C. At this time, the hop number 53 of the communication frame 50 is incremented by 1, and the communication frame 50 is passed to the node C (node B → node C).

  At time t5, the node C confirms the destination of the communication frame 50 received by the node B. In this case, the destination is the own node C. Further, since the number of hops stored in the communication frame 50 is 3, it can be seen that the communication frame 50 has been normally communicated, and the node C delivers the communication data 54 in the communication frame 50 to the application. .

  As described above, the node C can receive the communication data 54 from the node D at the time t4, the communication data 54 from the node A at the time t5, and receive the communication data 54 in the order of generation of the communication data 54. it can. However, at time t3, node A → node B and node B → node C communications occur simultaneously. That is, the node B must simultaneously receive from the node A and transmit to the node C. In order to realize this, there is a second problem that each of the nodes A to E needs to have two independent communication I / Fs. Here, if there is only one communication I / F as in a general communication terminal configuration, only one of the communication at time t3 can be realized. As a result, communication is performed at time t3 as shown in FIG. If not, it will take more time than the specified communication time.

  Next, the operation of the mesh network 100 when data is transmitted from the node A to the node B and from the node C to the node A will be described with reference to FIG.

  At time t1, communication data 54 is generated at node A. As shown in FIG. 2, the node A creates a communication frame 50 in which transmission source information 51 = node A, destination information 52 = node B, and hop number 53 = 0 are added to the communication data 54. Next, the node A refers to the table of the node A shown in FIG. 4 and confirms that there is no relay station with the remaining one hop to the destination node B. That is, node B is an adjacent node of node A. Since the current hop count is 0, it can be seen that there is a total of 1 hop up to Node B. This is different from the maximum number of hops 3 in the mesh network 100. Therefore, the node A adds 1 to the hop number 53 of the communication frame 50 without transmitting to the destination node B, and transmits the communication frame 50 to itself. At this time, since the communication is the communication frame 50 addressed to itself, the communication frame 50 is actually processed without transmitting the communication frame 50 using the communication path (node A → node A).

  At time t2, the node A confirms the destination of the communication frame 50 received by the node A. In this case, since the destination is not addressed to the own node A, the table of the own node A shown in FIG. 4 is referred to. Here, it can be seen that the destination node B has one hop remaining and no relay station. Since the number of hops 53 of the communication frame 50 is 1, it can be seen that there are 2 hops in total up to the node B. This is different from the maximum number of hops 3 in the mesh network 100. Therefore, the node A adds 1 to the hop number 53 of the communication frame 50 without transmitting to the destination node B, and transmits the communication frame 50 to itself. At this time, since the communication is the communication frame 50 addressed to itself, the communication frame 50 is actually processed without transmitting the communication frame 50 using the communication path (node A → node A).

  At time t2, communication data 54 is generated at node C. As shown in FIG. 2, the node C creates a communication frame 50 in which transmission source information 51 = node C, destination information 52 = node A, and hop number 53 = 0 are added to the communication data 54. Next, the node C refers to the table of the node C shown in FIG. 6 and confirms that the relay station is the node B with the remaining two hops to the destination node A. Since the current number of hops is 0, it can be seen that there are a total of 2 hops up to node C. This is different from the maximum number of hops 3 in the mesh network 100. Therefore, the node C adds 1 to the number of hops of the communication frame 50 without transmitting it to the node B of the relay station, and transmits the communication frame 50 to itself. At this time, since the communication is the communication frame 50 addressed to itself, the communication frame 50 is actually processed without transmitting the communication frame 50 using the communication path (node C → node C).

  At the time t3, the node A confirms the destination of the communication frame 50 received by the own node A. In this case, since the destination is not addressed to the own node A, the table of the own node A shown in FIG. 4 is referred to. Here, it can be seen that the destination node B has one hop remaining and no relay station. Since the number of hops 53 of the communication frame 50 is 2, it can be seen that there are a total of 3 hops up to the node B. This is the same as the maximum number of hops 3 in the mesh network 100, and the node A passes the communication frame 50 to the destination node B. At this time, the hop number 53 of the communication frame 50 is incremented by 1, and the communication frame 50 is passed to the node B (node A → node B).

  At time t3, the destination of the communication frame 50 received by the node C is confirmed at the node C. In this case, since the destination is not addressed to the own node C, the table of the own node C shown in FIG. 6 is referred to. Here, it is confirmed that the relay station is the node B with the remaining two hops to the destination node A. Since the current number of hops 53 is 1, it can be seen that there are a total of 3 hops up to node C. This is the same as the maximum number of hops 3 in the mesh network 100, and the node C passes the communication frame 50 to the node B which is a relay station. At this time, 1 is added to the hop number 53 of the communication frame 50, and the communication frame 50 is passed to the node B (node C → node B).

  At time t4, the node B confirms the destination of the communication frame 50 received by the node A. In this case, the destination is the own node B. Further, since the hop number 53 stored in the communication frame 50 is also 3, it can be seen that the communication frame 50 has been normally communicated, and the Node B delivers the communication data 54 of the communication frame 50 to the application. .

  At time t4, the node B simultaneously confirms the destination of the communication frame 50 received by the node C. In this case, since the destination is not addressed to the own node B, the table of the own node B shown in FIG. 5 is referred to. Here, it is confirmed that there is no relay station in the remaining one hop to the destination node A. That is, node A is an adjacent node of node B. Since the current number of hops 53 is 2, it can be seen that there are a total of 3 hops up to node A. This is the same as the maximum number of hops 3 in the mesh network 100, and the node B passes the communication frame 50 to the destination node A. At this time, the hop number 53 of the communication frame 50 is incremented by 1, and the communication frame 50 is passed to the node A (node B → node A).

  At time t5, the node A confirms the destination of the communication frame 50 received by the node B. In this case, the destination is the own node A. Further, since the hop number 53 stored in the communication frame 50 is also 3, it is understood that the communication frame 50 has been normally communicated, and the node A delivers the communication data 54 of the communication frame 50 to the application. .

  As described above, the node B receives the communication data 54 from the node A at time t4, and the node A receives the communication data 54 from the node C at time t5. Can be seen. However, at time t3, communication from node A → node B and node C → node B occurs simultaneously. That is, node B must perform two receptions from node A and node C. In order to realize this, there is a second problem that it is necessary to have two independent communication I / Fs. Further, in the node B, it is necessary to simultaneously hold two communication frames 50 from the node A and the node C.

Japanese Patent Laid-Open No. 4-368034 JP 2010-130585 A JP 2006-20302 A

  Therefore, a first object of the present invention is to provide a communication system in which the order of arrival of data to an application can be the order of occurrence of data in a mesh network. In addition, the present invention provides a communication system in which, in a mesh network, the arrival order of data to an application can be the order of data generation without having each communication node have a plurality of communication I / Fs. Let it be the 2nd subject.

  The invention according to claim 1 for solving the first problem described above includes a plurality of communication nodes each including a reception unit that receives data and a transmission unit that transmits data. In the communication system to be configured, the reception unit transmits the data including a communication time that has elapsed since transmission by the destination and source communication nodes, and each of the plurality of communication nodes performs maximum communication in the mesh network. Communication condition storage means for storing time and communication time from itself to all the other communication nodes connected to the mesh network in advance, and the data based on the destination of the data received by the receiving means Destination determination means for determining whether the address is for itself or another communication node, and the reception means received by the reception means by the destination determination means. The communication condition storage means at the maximum communication time stored in the communication condition storage means and the communication time that has elapsed since the data was transmitted by the communication node of the transmission source. The added value obtained by adding the communication time to the stored destination is compared, and if the added value is the same value as the maximum communication time, the data is transmitted to the application connected to itself, and the addition is performed. A first communication control means for controlling the data to be sent to the application after waiting for the time obtained by subtracting the added value from the maximum communication time when the value is smaller than the maximum communication time; It exists in the communication system characterized by having.

  The invention according to claim 2 for solving the second problem is that, when each of the plurality of communication nodes determines that the data received by the receiving unit is addressed to another communication node by the destination determining unit, A reception request transmitting means for transmitting a reception request including a subtraction time obtained by subtracting the added value from the maximum communication time to the communication node of the destination or the relay destination; a reception request transmitted from the other communication node; and Priority determination means for determining the data with the shortest subtraction time among the subtraction times included in the reception request transmitted by the reception request transmission means as the highest priority data, and the communication node that has transmitted the reception request for the highest priority data. A communication confirmation means for notifying communication permission and notifying the communication node that has requested reception of data that is not the highest priority data; and the reception request After receiving the notification that the communication is possible, the transmission means causes the transmission means to transmit the data to the destination or relay destination communication node, and when the communication impossible notification is received, the reception request is received until the communication permission notification is received. The communication system according to claim 1, further comprising: a second communication control unit that causes the transmission unit to repeatedly transmit the reception request.

  In the invention according to claim 3, the subtraction time included in the reception request transmitted from the other communication node is the same as the subtraction time included in the reception request transmitted by the reception request transmission unit. If it is, the communication system according to claim 2, wherein the data corresponding to the reception request transmitted by the reception request transmission means is determined as the highest priority data.

  The invention according to claim 4 is characterized in that the reception request transmission means transmits a reception request further including the received data-specific ID, and the priority determination means receives the reception request received from the other communication node. If there is only a plurality of and all have the same subtraction time, or if there are only a plurality of reception requests transmitted by the reception request transmitting means and all have the same subtraction time, the top priority data is determined based on the ID. It exists in the communication system of Claim 2 or 3 characterized by the above-mentioned.

  In the invention according to claim 5, the number of relays of the communication node relayed after being transmitted by the source communication node as the communication time that has elapsed since being transmitted by the source communication node to the data, The communication condition storage means stores in advance the maximum number of relays in the mesh network as the maximum communication time in the mesh network, and from itself to all the other communication nodes connected to the mesh network. 5. The communication according to claim 2, wherein the number of relays from itself to all the other communication nodes connected to the mesh network is stored in advance as the communication time of Exists in the system.

  In the invention according to claim 6, when the second communication control means receives the notification that the communication is possible, the second communication control unit increments the number of relays transmitted from the transmission source communication node included in the data, and When the transmission means transmits the data to the destination or relay destination communication node and receives the notification that the communication is not possible, the number of relays after being transmitted by the source communication node included in the data is incremented. The communication system according to claim 5, wherein the data is transmitted to itself.

  According to a seventh aspect of the present invention, when the first communication control means increments the number of relays transmitted from the transmission source communication node when the added value is smaller than the maximum number of relays, 7. The communication system according to claim 5, wherein the data is transmitted to the communication system.

  As described above, according to the first aspect of the present invention, when the first communication control means determines that the data received by the receiving means is addressed to itself by the destination determining means, the maximum stored in the communication condition storing means. The communication time is compared with an addition value obtained by adding the communication time to the destination stored in the communication condition storage means to the communication time that has passed since the transmission means transmits the data received by the receiving means. When the added value is the same as the maximum communication time, the data received by the receiving means is transmitted to the application connected to itself, and when the added value is smaller than the maximum communication time, the added value is subtracted from the maximum communication time. Control is made so that data is sent to the application after waiting for the amount of time. In other words, the time from the transmission of data from each communication node to the delivery to the application is matched with the maximum communication time of the mesh network, so the order of arrival of data to the application is generated even if the number of relays is different. It will not be different from the order. In addition, it is not necessary to manage the order of data in an application such as a system, apparatus, or software that processes arrived data, and can be configured simply.

  According to the second aspect of the present invention, the priority determination means uses the reception request transmitted from another communication node and the data with the shortest subtraction time out of the subtraction time included in the reception request transmitted by the reception request transmission means. When the second communication control unit receives a notification indicating that communication is possible after transmitting a reception request, the transmission unit transmits data to the destination or relay destination communication node and receives a notification indicating that communication is not possible. The reception request transmission unit repeats transmission of the reception request until a communication enable notification is received. Therefore, it is not possible to cause a communication node to perform a plurality of transmissions and receptions at the same time, or to perform transmission and reception at the same time, so that data can reach an application without having a plurality of communication I / Fs at each communication node. The order can be the order of data generation.

  According to the third aspect of the present invention, the priority determination means has the same subtraction time included in the reception request transmitted from another communication node and subtraction time included in the reception request transmitted by the reception request transmission means. If there is, since the data corresponding to the reception request transmitted by the reception request transmission means is determined as the highest priority data, the subtraction time included in the reception request transmitted by the own reception request transmission means and received from another communication node Even when the subtraction times included in the reception request are the same, the highest priority data can be determined.

  According to the invention of claim 4, when the priority determination means has a plurality of reception requests received from other communication nodes and all have the same subtraction time, or the reception request transmitted by the reception request transmission means If there is only a plurality and all have the same subtraction time, the highest priority data is determined based on the ID, so there are only a plurality of reception requests received from other communication nodes and all have the same subtraction time, or Even when there are only a plurality of reception requests to be transmitted by the reception request transmission means and all have the same subtraction time, the highest priority data can be determined.

  According to the fifth aspect of the present invention, even if the number of relays is different, the data arrival order does not differ from the data generation order.

  According to the sixth aspect of the present invention, when the second communication control unit receives the notification that communication is possible, the second communication control unit increments the number of relays transmitted from the transmission source communication node included in the data, and sends it to the transmission unit. Since the data is transmitted to the destination or relay destination communication node, the number of relays can be adjusted. In addition, when the second communication control means receives the notification that communication is not possible, the number of relays after being transmitted by the transmission source communication node included in the data is incremented and the data is transmitted to itself. The number of relays can be adjusted by the number of times of virtual transmission and reception, and the communication time can be counted with a simple configuration.

  According to the seventh aspect of the present invention, when the first communication control means increments the number of relays transmitted from the communication node of the transmission source when the added value is smaller than the maximum number of relays, Therefore, the number of relays can be adjusted by the number of times of virtual transmission and reception inside, and the communication time can be waited with a simple configuration.

It is a block diagram which shows one Embodiment of the communication system of this invention. It is explanatory drawing which shows the structural example of the communication frame as data transmitted within the communication system shown by FIG. It is a block diagram which shows the structure of the communication node shown by FIG. It is a table | surface which shows the communication path table of the communication node A shown by FIG. It is a table | surface which shows the communication route table of the communication node B shown by FIG. It is a table | surface which shows the communication route table of the communication node C shown by FIG. It is a table | surface which shows the communication route table of the communication node D shown by FIG. It is a table | surface which shows the communication route table of the communication node E shown by FIG. It is a flowchart which shows operation | movement of the communication node shown by FIG. It is explanatory drawing which shows transmission of the communication frame in the communication system shown by FIG. It is explanatory drawing which shows transmission of the communication frame in the communication system shown by FIG. It is explanatory drawing which shows transmission of the communication frame in the communication system shown by FIG. It is a block diagram of the communication system using the conventional mesh network. It is explanatory drawing for demonstrating the conventional problem. It is explanatory drawing for demonstrating the conventional problem. It is explanatory drawing for demonstrating the conventional problem.

  The communication system of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the communication system 1 of the present invention includes a plurality of communication nodes 20 (node A, node B, node C, node D, and node E). A mesh network is configured.

  In the communication system 1 shown in FIG. 1, the node A is connected to the node B so as to communicate with each other. Node B is connected to nodes A, C, and D so that they can communicate with each other. Node C is connected to nodes B and E so that they can communicate with each other. Node D is connected to nodes B and E so that they can communicate with each other. Node E is connected to nodes C and D so that they can communicate with each other. In the present embodiment, it is assumed that the communication speed between the communication nodes 20 is the same.

  FIG. 2 shows a configuration example of a communication frame 50 as data transmitted in the communication system 1. The communication frame 50 includes transmission source information 51, destination information 52, a hop number 53, and communication data 54. The frame length of the communication frame 50 is fixed.

  The source information 51 stores information (for example, the node A) indicating the source communication node 20 that generated the communication frame 50, and the destination information 52 is information (for example, the destination communication node 20 of the communication frame 50). Node E) is stored.

  The hop number 53 stores the number (number of relays) of the communication nodes 20 relayed after the communication frame 50 is transmitted by the transmission source communication node 20, and the communication data 54 is used by the destination communication node 20. Data is stored. The number of hops 53 corresponds to the communication time that has elapsed since the transmission by the communication node 20 of the transmission source.

  Each of the communication nodes 20 is composed of, for example, a CPU. FIG. 3 shows a block diagram of the communication node 20. The communication node 20 includes a communication frame creation unit 2, a communication I / F 3, a data reception unit 4 as a reception unit, a plurality of reception buffers 5, a data transmission unit 6 as a transmission unit, and a plurality of transmission buffers 7. A communication path table 8 as communication condition storage means, a maximum hop count storage section 9 as communication condition storage means, a destination determination section 10 as destination determination means, and a hop number predictor as first communication control means 11, a communication control unit 12 as a first communication control unit, a reception request transmission unit, a priority determination unit, a communication confirmation unit 13 as a second communication confirmation unit, a virtual communication path 14, and an application notification unit 15 It is equipped with.

  When the communication data 54 is transmitted via the application notification unit 15, the communication frame creation unit 2 creates a communication frame 50 as shown in FIG. 2 and transmits it to the communication confirmation unit 13 described later.

  The communication I / F 3 is an interface for inputting / outputting an external communication frame 50 and a later-described reception request and communication availability notification. The communication frame 50 input from the outside is output to the data receiving unit 4 and is externally input. The input reception request and communication availability notification described later are output to the communication confirmation unit 13 described later, and the communication frame 50 input from the data transmission unit 6 is output to the outside.

  The data receiving unit 4 receives a communication frame 50 input from the communication I / F 3 or a virtual communication path 14 described later, and stores it in the reception buffer 5. A plurality of reception buffers 5 are provided, and a plurality of communication frames 50 can be stored.

  The data transmission unit 6 outputs the communication frame 50 selected by the communication control unit 12 described later from the communication frames 50 stored in the transmission buffer 7 to the communication I / F 3. A plurality of transmission buffers 7 are provided, and a plurality of communication frames 50 can be stored.

  As shown in FIGS. 4 to 8, the communication path table 8 has the number of hops to the communication nodes 20 other than itself constituting the communication system 1, that is, from all of the communication nodes 20 connected to the mesh network. The communication time (the number of relays), the presence / absence of relay stations, and the relay station name (information that can indicate the relay station such as an address) when there are relay stations are stored in advance on the table for each communication node 20.

  The maximum hop count storage unit 9 stores in advance the maximum hop count (maximum number of relays) as the maximum communication time in the communication system 1. In this embodiment, the communication path table 8 and the maximum hop count storage unit 9 are configured separately, but each area may be provided in one memory or the like.

  The destination determination unit 10 analyzes the destination information 52 in the communication frame 50 stored in the reception buffer 5 and outputs the communication frame 50 to the communication control unit 12 when it is the communication frame 50 addressed to itself. The communication frame 50 is output to the communication confirmation unit 13.

  The hop number predictor 11 adds the number of hops to the destination stored in the communication path table 8 to the hop number 53 of the communication frame 50 input from the communication control unit 12 or the communication confirmation unit 13 described later (addition). Value) is predicted, and the result is output to the communication control unit 12 and the communication confirmation unit 13.

  When receiving the communication frame 50 addressed to the own node from the destination determination unit 10, the communication control unit 12 outputs the communication frame 50 to the hop number predictor 11 in order to obtain the total hop number. When the communication control unit 12 inputs the total hop number predicted by the hop number predictor 11, the maximum hop number stored in the maximum hop number storage unit 9 and the total hop number predicted by the hop number predictor 11. When the total hop count and the maximum hop count are the same, the communication frame 50 is output to the application notification section 15 connected to itself and the total hop count is smaller than the maximum hop count. Increments the number of hops 53 in the communication frame 50 and outputs the communication frame 50 to the virtual communication path 14.

  When the communication confirmation unit 13 receives a communication frame 50 addressed to another node from the destination determination unit 10 or the communication frame creation unit 2, the communication confirmation unit 13 stores the communication frame 50 in the transmission buffer 7 and calculates the total number of hops. The frame 50 is output to the hop number predictor 11. In addition, the communication confirmation unit 13 selects a relay station necessary for transmitting the communication frame 50 input with reference to the communication path table 8 described above to the destination communication node 20.

  Further, when the total hop number predicted by the hop number predictor 11 is input, the communication confirmation unit 13 subtracts the total hop number from the maximum hop number stored in the maximum hop number storage unit 9 (subtraction time). ), And creates and creates a reception request including the obtained number of remaining hops and the transmission source information 51 (the ID unique to the received data) of the communication frame 50 input from the destination determination unit 10 or the communication frame creation unit 2 The received reception request is transmitted to the selected relay station via the communication I / F 3.

  Further, when the communication confirmation unit 13 inputs a reception request from the communication I / F 3, when the communication frame 50 is stored in the number of remaining hops included in the reception request, the transmission source information 51, and the transmission buffer 7. The number of remaining hops included in the reception request of the communication frame 50 and the transmission source information 51 are compared, and the communication frame 50 with the highest priority is determined as the highest priority frame (highest priority data).

Here, the determination of the highest priority frame is performed according to the following (1) to (5).
(1) The communication frame 50 having the smallest number of remaining hops among reception requests received from other communication nodes and reception requests transmitted to other communication nodes is designated as the highest priority frame (no distinction between reception requests and transmission requests). ).
(2) When the number of remaining hops of the reception request received from the other communication node and the reception request transmitted to the other communication node are the same, it corresponds to the reception request transmitted to the other communication node. The communication frame 50 is the highest priority frame.
(3) When there are a plurality of reception requests transmitted from other communication nodes, and each has the same number of remaining hops, the highest priority frame of the transmission source information 51 is set as the highest priority frame.
(4) When there are only a plurality of reception requests transmitted to other communication nodes, and each has the same remaining hop count, the highest priority frame of the transmission source information 51 is determined.
(5) A communication frame transmitted to the own node is not included in the priority determination.

  In addition, the communication confirmation unit 13 notifies the communication node 20 that has transmitted the reception request of the highest priority frame that communication is possible, and prohibits communication to the communication node 20 that has transmitted the reception request of the communication frame 50 that is not the highest priority frame. Notice. Specifically, for example, in the node B, when reception requests are transmitted from the nodes A, D, and C, and the communication frame 50 for which the reception request is made by the node A is the highest priority frame, the node B Notify that the communication is possible, and notify nodes D and C that communication is not possible. On the other hand, when the communication frame 50 corresponding to the reception request transmitted by the node B itself is the highest priority frame, the node B notifies the nodes A, D, and C that communication is impossible.

  In addition, when the communication confirmation unit 13 receives a notification that communication is possible from another communication node 20 after transmitting the reception request, the communication confirmation unit 13 increments the hop number 53 of the communication frame 50 stored in the transmission buffer 7 requested to receive (+1) And output to the data transmission unit 6. When receiving a communication failure notification from another communication node 20, the communication confirmation unit 13 increments the hop number 53 of the communication frame 50 stored in the transmission buffer 7 requested to receive the communication frame 50 to the virtual communication path 14. Output.

  The virtual communication path 14 transmits the communication frame 50 from the communication control unit 12 or the communication confirmation unit 13 to the data reception unit 4 in order to virtually transmit the communication frame 50 within the communication node 20.

  When receiving the communication frame 50 from the communication control unit 12, the application notification unit 15 notifies the application executed in its own communication node 20, extracts the communication data 54 in the communication frame 50, and delivers it to the application. The application refers to a unit (for example, window lock) that executes a function assigned to the communication node 20 among devices and systems (for example, vehicle window control) realized in the entire communication system 1. Although not shown in the figure, it is configured by hardware or software.

  Next, the operation of the communication node 20 configured as described above will be described with reference to the flowchart of FIG.

  First, in step S101, the communication node 20 determines whether or not communication data 54 has occurred within itself. If it has occurred (in the case of Y), the process proceeds to step S102, and if it has not occurred (in the case of N). ) Proceeds to step S111. In this step, for example, it is determined whether or not the application notification unit 15 has received communication data 54 to be transmitted from the application to another communication node 20.

  Next, in step S102, the communication node 20 creates the communication frame 50 and proceeds to step S103. In this step, the data received by the application notification unit 15 is transmitted to the communication frame creation unit 2, and the communication frame creation unit 2 generates a communication frame 50 from the communication data 54 received from the application notification unit 15 and sends it to the communication confirmation unit 13. Output. The communication confirmation unit 13 stores the communication frame 50 in the transmission buffer 7.

  In step S <b> 103, the communication confirmation unit 13 of the communication node 20 refers to the communication path table 8 and relays necessary for transferring the communication frame 50 stored in the transmission buffer 7 to the destination communication node 20. A station (destination if direct transmission to the destination) is selected, and the process proceeds to step S104.

  Next, in step S104, the communication node 20 predicts the total number of hops of the communication frame 50 stored in the transmission buffer 7, and proceeds to step S105. In this step, the communication confirmation unit 13 causes the hop number predictor 11 to predict the total number of hops to the destination of the communication frame 50.

  Next, in step S105, the communication node 20 obtains the remaining hop count obtained by subtracting the total hop count predicted in step S105 from the maximum hop count stored in the maximum hop count storage unit 9, and the obtained remaining hop count and A reception request including the transmission source information 51 of the communication frame 50 stored in the transmission buffer 7 is created, this reception request is transmitted to the relay station or destination selected in step S103, and the process proceeds to step S106. In this step, the communication confirmation unit 13 outputs a reception request to the communication I / F 3.

  Next, in step S106, when the communication confirmation unit 13 of the communication node 20 is notified that communication is possible from the relay station or destination selected in step S103 in response to the reception request (in the case of Y), the process proceeds to step S107. When communication failure is notified (in the case of N), the process proceeds to step S109.

  Next, in step S107, the communication node 20 adds (increments) the hop number 53 in the communication frame 50, and proceeds to step S108.

  Next, in step S108, the communication node 20 transmits the communication frame 50 to the relay station or destination selected in step S103, and returns to step S101. In this step, the communication frame 50 is transmitted from the data transmission unit 6 to the destination or relay destination communication node 20 via the communication I / F 3.

  Next, in step 109, the communication node 20 adds (increments) the hop number 53 in the communication frame 50, and proceeds to step S110.

  Next, in step S110, the communication node 20 performs internal communication addressed to its own node, and returns to step S101. In this step, the communication frame 50 is transmitted from the communication confirmation unit 13 to the data reception unit 4 via the virtual communication path 14.

  On the other hand, in step S111, the communication node 20 determines whether or not the communication frame 50 has been received from the adjacent communication node 20, and proceeds to step S112 if received (in the case of Y). If (N), the process proceeds to step S119.

  Next, in step S112, the communication node 20 performs destination determination and proceeds to step S113. In this step, the destination determination unit 10 analyzes the destination information 52 in the communication frame 50 to determine whether it is addressed to itself or to another communication node 20. When output to the communication control unit 12 and addressed to another communication node 20, the communication frame 50 is output to the communication confirmation unit 13.

  Next, in step S113, the communication node 20 determines whether or not it is addressed to its own node as a result of step S112. If it is addressed to its own node, the process proceeds to step S114. Proceed to step S103.

  Next, in step S114, the communication control unit 12 of the communication node 20 confirms the hop number 53 in the communication frame 50 addressed to the own node, and proceeds to step S115.

  Next, in step S115, the communication control unit 12 of the communication node 20 determines whether or not the hop number 53 confirmed in step S114 is the same as the maximum hop number stored in the maximum hop number storage unit 9, and the same If (if Y), the process proceeds to step S116, and if not (N), the process proceeds to step S117.

  Next, in step S116, the communication node 20 delivers the communication data 54 in the communication frame 50 to the application. In this step, the communication control unit 12 outputs the communication frame 50 to the application notification unit 15, and the application notification unit 15 delivers the communication data 54 in the communication frame 50 to the application.

  Next, in step S117, the communication control unit 12 of the communication node 20 adds (increments) the hop number 53 in the communication frame 50, and proceeds to step S118.

  Next, in step S118, the communication node 20 performs internal communication addressed to its own node similarly to step S110, and returns to step S101.

  On the other hand, in step S119, the communication node 20 determines whether or not a reception request has been received from the adjacent communication node 20, and if received (in the case of Y), the process proceeds to step S111. In the case of N), the process returns to step S101.

  Next, in step S120, the communication node 20 determines the highest priority data and proceeds to step S121. In this step, the communication confirmation unit 13 includes the number of remaining hops included in the reception request received from the adjacent communication node 20, the transmission source information 51, and the remaining hop included in the reception request transmitted to the adjacent communication node 20. The communication frame 50 having the highest priority is determined as the highest priority frame (highest priority data).

  Next, in step S121, the communication node 20 notifies whether communication is possible and returns to step S101. In this step, the communication confirmation unit 13 controls the communication I / F 3 to notify the communication node 20 that has transmitted the highest priority frame reception request that communication is possible and to receive the communication frame 50 that is not the highest priority frame. Is notified to the communication node 20 that transmitted the message.

  Next, an operation example of the communication system 1 (mesh network) having a plurality of communication nodes 20 having the above-described configuration will be described. 4 to 8 show the contents of the communication path table 8 to the nodes A to E. FIG. The maximum number of hops of the mesh network constituting the communication system 1 is 3, and this value is stored in advance in the maximum hop number storage unit 9 of each communication node 20.

  First, as an example, an operation of the communication system 1 when data is transmitted from the node D to the node C and from the node A to the node C will be described with reference to FIG.

  First, the operation of each node A to E at time t1 will be described. Communication data 54 is generated at node D. As illustrated in FIG. 2, the node D creates a communication frame 50 in which the transmission source information 51, the destination information 52, and the hop number 53 are added to the communication data 54, and stores the communication frame 50 in the transmission buffer 7. At this time, the node D creates a communication frame 50 in which the node D is stored as the transmission source information 51, the node C is stored as the destination information 52, and 0 is stored as the hop number 53.

  Next, the node D refers to the table of the node D shown in FIG. 7 and selects the node B as a relay station. Further, the node D predicts the total number of hops = 2, which is obtained by adding the number of hops to the destination stored in the communication path table 8 to the number of hops 53 = 0 of the created communication frame 50.

  Next, the node D obtains the remaining hop count = 1 by subtracting the total hop count = 2 from the maximum hop count = 3, the obtained remaining hop count = 1, and the transmission source information 51 of the created communication frame 50 = node A reception request including D is generated, and the reception request generated via the communication I / F 3 is transmitted to the selected relay node B.

  When the node B receives the reception request, the node B determines the highest priority frame. Here, as shown in FIG. 10, Node B does not communicate with others and is free, and therefore determines that communication frame 50 corresponding to the reception request transmitted from Node D is the highest priority frame. Then, a notification indicating that communication is possible is transmitted to the node D. Upon receiving the notification that communication is possible, the node D adds 1 to the hop number 53 of the communication frame 50 to set the hop number 53 = 1, and transmits the communication frame 50 to the node B (node D → node B).

  The operation of each of the nodes A to E at the next time t2 will be described. The node B determines the destination information 52 of the communication frame 50 received from the node D. In this case, since the destination information 52 is not addressed to the node B, the node B refers to the communication path table 8 of the node B shown in FIG. 5 and selects the node C as the destination without the relay station.

  Next, the node B predicts the total number of hops = 2 by adding the number of hops 53 = 1 to the destination stored in the communication path table 8 to the number of hops 53 = 1 of the communication frame 50 transmitted from the node D. . Next, the node B obtains the number of remaining hops = 1 by subtracting the total number of hops = 2 from the maximum number of hops = 3, and obtains the number of remaining hops = 1 and the transmission source of the communication frame 50 transmitted from the node D Information 51 = A reception request including the node D is created, and the reception request created via the communication I / F 3 is transmitted to the selected destination node C.

  When the node C receives the reception request, the node C determines the highest priority frame. Here, as shown in FIG. 10, the node C does not communicate with others and is free, so the communication frame 50 corresponding to the reception request transmitted from the node B is determined as the highest priority frame. Then, a communication enable notification is transmitted to the node B. Upon receiving the notification that communication is possible, the node B adds 1 to the hop number 53 of the communication frame 50 to set the hop number 53 = 2, and transmits the communication frame 50 to the node C (node B → node C).

  On the other hand, communication data 54 is generated at the node A at time t2. As illustrated in FIG. 2, the node A creates a communication frame 50 in which transmission source information 51, destination information 52, and hop number 53 are added to the communication data 54, and stores the communication frame 50 in the transmission buffer 7. At this time, the node A creates a communication frame 50 in which the node A is stored as the source information 51, the node C is stored as the destination information 52, and 0 is stored as the hop number 53.

  Next, the node A refers to the node A table shown in FIG. 4 and selects the node B as a relay station. Further, the node A predicts the total number of hops = 2 by adding the number of hops 53 to the destination stored in the communication path table 8 to the number of hops 53 = 0 of the created communication frame 50.

  Next, the node A obtains the remaining hop count = 1 by subtracting the total hop count = 2 from the maximum hop count = 3, the obtained remaining hop count = 1, and the transmission source information 51 of the created communication frame 50 = node A reception request including A is generated, and the reception request generated via the communication I / F 3 is transmitted to the selected relay node B.

  When the node B receives the reception request, the node B determines the highest priority frame. Here, as shown in FIG. 10, since the node B has the communication frame 50 to be transmitted to the node C having the same number of remaining hops as the number of remaining hops of the reception request, the transmission is given priority to the transmission to the node C. The communication frame 50 to be determined is determined as the highest priority frame, and a communication failure notification is transmitted to the node B. When the node A receives the communication disabled notification, the node A adds 1 to the hop number 53 of the communication frame 50 that has transmitted the reception request, and performs internal communication with the communication frame 50 having the hop number 53 = 1 addressed to itself (node). A → Node A).

  The operation of each of the nodes A to E at the next time t3 will be described. The node C determines the destination information 52 of the communication frame 50 received from the node B. In this case, since the destination information 52 is addressed to the own node C, the node C predicts the hop count 53 = 2 of the communication frame 50 received from the node B as the total hop count 2 (that is, the hop count 53 to the destination). = 0).

  Since the predicted total number of hops = 2 is smaller than the maximum number of hops = 3, the node C adds 1 to the hop number 53 of the communication frame 50 received from the node B to set the hop number 53 = 3. Is communicated to its own node (node C → node C).

  On the other hand, the node A determines the destination information 52 of the communication frame 50 received from the own node A. In this case, since the destination information 52 is not addressed to the node A, the node A refers to the communication path table 8 of the node A shown in FIG. 4 and selects the node B as the relay station.

  Next, the node A predicts the total number of hops = 3 by adding the number of hops 53 = 2 to the destination stored in the communication route table 8 to the number of hops 53 = 1 of the communication frame 50 transmitted from the node A. To do.

  Next, the node A obtains the number of remaining hops = 0 by subtracting the total number of hops = 3 from the maximum number of hops = 3, and includes the obtained number of remaining hops 0 and the transmission source information 51 = node A of the communication frame 50. A reception request is generated, and the reception request generated via the communication I / F 3 is transmitted to the selected relay station node B.

  When the node B receives the reception request, the node B determines the highest priority frame. Here, as shown in FIG. 10, Node B does not communicate with others and is free, so the communication frame 50 corresponding to the reception request transmitted from Node A is determined as the highest priority frame. Then, a notification indicating that communication is possible is transmitted to node A. Upon receiving the notification that communication is possible, the node A adds 1 to the hop number 53 of the communication frame 50 to set the hop number 53 to 3, and transmits the communication frame 50 to the node B (node A → node B).

  Next, the operation of each of the nodes A to E at time t4 will be described. The node C determines the destination information 52 of the communication frame 50 received from its own node C. In this case, since the destination information 52 is addressed to the own node C, the node C predicts the hop number 53 = 3 of the communication frame 50 received from the own node C and the total hop number 53 = 3. Since the predicted total hop count = 3 is the same as the maximum hop count = 3, the node C delivers the communication data 54 of the communication frame 50 received from the node C to the application.

  On the other hand, the node B determines the destination information 52 of the communication frame 50 received from the node A. In this case, since the destination information 52 is not addressed to the node B, the node B refers to the communication path table 8 of the node B shown in FIG. 5 and selects the destination node C without a relay station.

  Next, the node B predicts the total number of hops = 3 by adding the number of hops 53 = 1 to the destination stored in the communication path table 8 to the number of hops 53 = 2 of the communication frame 50 transmitted from the node A. .

  Next, the node B obtains the remaining hop count = 0 by subtracting the total hop count = 3 from the maximum hop count = 3, and includes the obtained remaining hop count 0 and the transmission source information 51 = node A of the communication frame 50. A reception request is generated, and the reception request generated via the communication I / F 3 is transmitted to the selected destination node C.

  When the node C receives the reception request, the node C determines the highest priority frame. Here, as shown in FIG. 10, the node C does not communicate with others and is free, so the communication frame 50 corresponding to the reception request transmitted from the node B is determined as the highest priority frame. Then, a communication enable notification is transmitted to the node B. Upon receiving the notification that communication is possible, the node C adds 1 to the hop number 53 of the communication frame 50 to set the hop number 53 to 3, and transmits the communication frame 50 to the node C (node B → node C).

  Next, the operation of each of the nodes A to E at time t5 will be described. The node C determines the destination information 52 of the communication frame 50 received from the node B. In this case, since the destination information 52 is addressed to the own node C, the node C predicts the number of hops 53 = 3 of the communication frame 50 received from the own node C as the total number of hops = 3. Since the predicted total hop count = 3 is the same as the maximum hop count = 3, the node C delivers the communication data 54 of the communication frame 50 received from the node C to the application.

  As is clear from FIG. 10, at node C, communication data 54 of communication frame 50 from node D is delivered to the application at time t4, and communication data 54 of communication frame 50 from node A is delivered to the application at time t5. The data 54 can be delivered to the application in the order of generation. In addition, no node A to E communicates at the same time.

  As the next example, the operation of the communication system 1 when data is transmitted from the node A to the node B and from the node C to the node A will be described with reference to FIG.

  First, the operation of each node A to E at time t1 will be described. Communication data 54 is generated at node A. As illustrated in FIG. 2, the node A creates a communication frame 50 in which transmission source information 51, destination information 52, and hop number 53 are added to the communication data 54, and stores the communication frame 50 in the transmission buffer 7. At this time, the node A creates a communication frame 50 in which the node A is stored as the transmission source information 51, the node B is stored as the destination information 52, and 0 is stored as the hop number 53.

  Next, node A refers to the table of node A shown in FIG. 4 and selects destination node B without a relay station. Further, the node A predicts the total number of hops = 1 by adding the number of hops 53 = 1 to the destination stored in the communication path table 8 to the number of hops 53 = 0 of the created communication frame 50.

  Next, the node A obtains the remaining hop count = 2 by subtracting the total hop count = 1 from the maximum hop count = 3, the obtained remaining hop count = 2, and the transmission source information 51 of the created communication frame 50 = node A reception request including A is created, and the reception request created via the communication I / F 3 is transmitted to the selected destination node B.

  When the node B receives the reception request, the node B determines the highest priority frame. Here, as shown in FIG. 11, the node B does not communicate with others and is free, so the communication frame 50 corresponding to the reception request transmitted from the node A is determined as the highest priority frame. Then, a notification indicating that communication is possible is transmitted to node A. Upon receiving the notification that communication is possible, the node A adds 1 to the hop number 53 of the communication frame 50 to set the hop number 53 = 1, and transmits the communication frame 50 to the node B (node A → node B).

  The operation of each of the nodes A to E at the next time t2 will be described. The node B determines the destination information 52 of the communication frame 50 received from the node A. In this case, since the destination information 52 is addressed to the own node B, the node B predicts the hop count 53 = 1 of the communication frame 50 received from the node A as the total hop count = 1. Since the predicted total hop count = 1 is smaller than the maximum hop count = 3, the node B adds 1 to the hop count 53 of the communication frame 50 received from the node A to set the hop count 53 = 2. Is communicated to its own node B (node B → node B).

  On the other hand, communication data 54 is generated at the node C. As illustrated in FIG. 2, the node C creates a communication frame 50 in which the transmission source information 51, the destination information 52, and the hop number 53 are added to the communication data 54, and stores the communication frame 50 in the transmission buffer 7. At this time, the node C creates a communication frame 50 that stores the node C as the source information 51, the node A as the destination information 52, and 0 as the hop number 53.

  Next, the node C selects the relay station node B with reference to the table of the node C shown in FIG. In addition, the node C predicts the total number of hops = 2 by adding the number of hops 53 = 2 to the destination stored in the communication path table 8 to the number of hops 53 = 0 of the created communication frame 50.

  Next, the node C obtains the remaining hop count = 1 by subtracting the total hop count = 2 from the maximum hop count = 3, the obtained remaining hop count = 1, and the transmission source information 51 of the created communication frame 50 = node A reception request including C is generated, and the reception request generated via the communication I / F 3 is transmitted to the selected relay station node B.

  When the node B receives the reception request, the node B determines the highest priority frame. Here, as shown in FIG. 11, the node B has the communication frame 50 transmitted from the node A, but is the processing data in the own node B, and the communication I / F 3 is free. Therefore, the communication frame 50 corresponding to the reception request transmitted from the node C is determined as the highest priority frame, and a communication enable notification is transmitted to the node C. Upon receiving the notification that communication is possible, the node C adds 1 to the hop number 53 of the communication frame 50 to set the hop number 53 = 1, and transmits the communication frame 50 to the node B (node C → node B).

  The operation of each of the nodes A to E at the next time t3 will be described. The node B determines the destination information 52 of the communication frame 50 received from the own node B. In this case, since the destination information 52 is addressed to the own node B, the node B predicts the hop number 53 = 2 of the communication frame 50 received from the own node B as the total hop number = 2. Since the predicted total number of hops = 2 is smaller than the maximum number of hops = 3, the node B adds 1 to the hop number 53 of the communication frame 50 received from its own node B, and sets the hop number 53 = 3. 50 performs internal communication addressed to its own node B (node B → node B).

  At the same time, the node B determines the destination information 52 of the communication frame 50 received from the node C. In this case, since the destination information 52 is not addressed to the node B, the node B refers to the communication path table 8 of the node B shown in FIG. 5 and selects the node A as the destination without the relay station.

  Next, the node B predicts the total number of hops = 2 by adding the number of hops 53 = 1 to the destination stored in the communication path table 8 to the number of hops 53 = 1 of the communication frame 50 transmitted from the node C. . Next, the node B obtains the number of remaining hops = 1 by subtracting the total number of hops = 2 from the maximum number of hops = 3, and obtains the number of remaining hops = 1 and the transmission source of the communication frame 50 transmitted from the node C. Information 51 = A reception request including node C is created, and the reception request created via the communication I / F 3 is transmitted to the selected destination node A.

  When the node A receives the reception request, the node A determines the highest priority frame. Here, as shown in FIG. 11, since the node A does not communicate with others and is in an idle state, the communication frame 50 corresponding to the reception request transmitted from the node B is determined as the highest priority frame. Then, a communication enable notification is transmitted to the node B. Upon receiving the notification that communication is possible, the node B adds 1 to the hop number 53 of the communication frame 50 to set the hop number 53 = 2, and transmits the communication frame 50 to the node A (node B → node A).

  The operation of each of the nodes A to E at the next time t4 will be described. The node B determines the destination information 52 of the communication frame 50 received from the own node B. In this case, since the destination information 52 is addressed to the own node B, the node B predicts the hop number 53 = 3 of the communication frame 50 received from the own node B as the total hop number = 3. Since the predicted total number of hops = 3 is the same as the maximum number of hops = 3, the node B delivers the communication data 54 of the communication frame 50 received from its own node B to the application.

  In the node A, the destination information 52 of the communication frame 50 received from the node B is determined. In this case, since the destination information 52 is addressed to the own node A, the node A has the hop number 53 = 0 of the communication frame 50 received from the node B and the hop number 53 = 0 to the destination stored in the communication path table 8. The total number of hops by adding = 2 is predicted. Since the predicted total number of hops = 2 is smaller than the maximum number of hops = 3, the node A adds 1 to the hop number 53 of the communication frame 50 received from the node B to set the hop number 53 = 3. To the local node A (node A → node A).

  The operation of each of the nodes A to E at the next time t5 will be described. The node A determines the destination information 52 of the communication frame 50 received from its own node A. In this case, since the destination information 52 is addressed to the own node A, the node A predicts the hop number 53 = 3 of the communication frame 50 received from the own node A as the total hop number = 3. Since the predicted total hop count = 3 is the same as the maximum hop count = 3, the node A delivers the communication data 54 of the communication frame 50 received from the node A to the application.

  As described above, as illustrated in the example of the node B at the time t3, by allowing a plurality of data to be held, the node B transmits the communication frame 50 from the node A at the time t4 and the node A to the node C at the time t5. The communication frame 50 can be received and delivered to the application in the order in which the communication data 54 is generated. In addition, no node A to E communicates at the same time.

  As the next example, the operation of the communication system 1 when data is transmitted from the node B to the node E and from the node E to the node A will be described with reference to FIG.

  First, the operation of each node A to E at time t1 will be described. Communication data 54 is generated at the node B. As illustrated in FIG. 2, the node B creates a communication frame 50 in which transmission source information 51, destination information 52, and the hop number 53 are added to the communication data 54, and stores the communication frame 50 in the transmission buffer 7. At this time, the node B creates a communication frame 50 in which the node B is stored as the transmission source information 51, the node E is stored as the destination information 52, and 0 is stored as the hop number 53.

  Next, the node B selects the relay station node C with reference to the table of the node B shown in FIG. Further, the node B predicts the total number of hops = 2 by adding the number of hops 53 = 2 to the destination stored in the communication path table 8 to the number of hops 53 = 0 of the created communication frame 50.

  Next, the node B obtains the remaining hop count = 1 by subtracting the total hop count = 2 from the maximum hop count = 3, the obtained remaining hop count = 1, and the transmission source information 51 of the created communication frame 50 = node A reception request including B is created, and the reception request created via the communication I / F 3 is transmitted to the selected destination node C.

  When the node C receives the reception request, the node C determines the highest priority frame. Here, as shown in FIG. 11, the node C does not communicate with others and is free, so the communication frame 50 corresponding to the reception request transmitted from the node B is determined as the highest priority frame. Then, a communication enable notification is transmitted to the node B. Upon receiving the notification that communication is possible, the node B adds 1 to the hop number 53 of the communication frame 50 to set the hop number 53 = 1, and transmits the communication frame 50 to the node C (node B → node C).

  The operation of each of the nodes A to E at the next time t2 will be described. Communication data 54 is generated at the node E. As illustrated in FIG. 2, the node E creates a communication frame 50 in which transmission source information 51, destination information 52, and the hop number 53 are added to the communication data 54, and stores the communication frame 50 in the transmission buffer 7. At this time, the node E creates a communication frame 50 that stores the node E as the transmission source information 51, the node A as the destination information 52, and 0 as the hop number 53.

  Next, the node E refers to the table of the node D shown in FIG. 8 and selects the node D as a relay station. Further, the node E predicts the total number of hops = 3 by adding the number of hops 53 to 3 to the destination stored in the communication path table 8 to the number of hops 53 = 0 of the created communication frame 50.

  Next, the node E obtains the remaining hop count = 0 by subtracting the total hop count = 3 from the maximum hop count = 3, the obtained remaining hop count = 0, and the transmission source information 51 of the created communication frame 50 = node A reception request including E is generated, and the reception request generated via the communication I / F 3 is transmitted to the selected relay station node D.

  When the node D receives the reception request, the node D determines the highest priority frame. Here, as shown in FIG. 12, the node D does not communicate with others and is free, so the communication frame 50 corresponding to the reception request transmitted from the node E is determined as the highest priority frame. Then, a notification indicating that communication is possible is transmitted to the node E. Upon receiving the notification that communication is possible, the node E adds 1 to the hop number 53 of the communication frame 50, sets the hop number 53 = 1, and transmits the communication frame 50 to the node B (node E → node D).

  On the other hand, the node C determines the destination information 52 of the communication frame 50 received from the node B. In this case, since the destination information 52 is not addressed to the node C, the node C refers to the communication path table 8 of the node C shown in FIG. 6 and selects the node E as the destination.

  Next, the node C predicts the total number of hops = 2 by adding the number of hops 53 = 1 to the destination stored in the communication path table 8 to the number of hops 53 = 1 of the communication frame 50 transmitted from the node B. .

  Next, the node C obtains the remaining hop count = 1 by subtracting the total hop count = 2 from the maximum hop count = 3, and includes the obtained remaining hop count 1 and the transmission source information 51 of the communication frame 50 = node B A reception request is created, and the reception request created via the communication I / F 3 is transmitted to the selected destination node E.

  When the node E receives the reception request, the node E determines the highest priority frame. Here, as shown in FIG. 12, since the node E has the communication frame 50 to be transmitted to the node D having the remaining hop count smaller than 1 and the remaining hop count = 0, the transmission is given priority. The communication frame 50 to be transmitted to the node D is determined as the highest priority frame, and a communication failure notification is transmitted to the node C. When the node C receives the notification that communication is not possible, the node C adds 1 to the hop number 53 of the communication frame 50 that has transmitted the reception request, and performs internal communication with the communication frame 50 having the hop number 53 = 1 addressed to itself (node). C → node C).

  The operation of each of the nodes A to E at the next time t3 will be described. The node C determines the destination information 52 of the communication frame 50 received from its own node C. In this case, since the destination information 52 is not addressed to the node C, the node C refers to the communication path table 8 of the node C shown in FIG. 6 and selects the node E as the destination without the relay station.

  Next, the node C predicts the total number of hops = 3 by adding the number of hops 53 = 1 to the destination stored in the communication path table 8 to the number of hops 53 = 2 of the communication frame 50 transmitted from the node C. To do. Next, the node C obtains the number of remaining hops = 0 by subtracting the total number of hops = 3 from the maximum number of hops = 3, and transmits the obtained number of remaining hops = 0 and the communication frame 50 transmitted from the own node C. Source information 51 = A reception request including node B is created, and the reception request created via the communication I / F 3 is transmitted to the selected destination node E.

  When the node E receives the reception request, the node E determines the highest priority frame. Here, as illustrated in FIG. 11, the node E does not communicate with others and is free, so the communication frame 50 corresponding to the reception request transmitted from the node C is determined as the highest priority frame. Then, a notification indicating that communication is possible is transmitted to the node C. When the node C receives the notification that communication is possible, the hop number 53 of the communication frame 50 is incremented by 1 to set the hop number 53 = 3, and the communication frame 50 is transmitted to the node E (node C → node E).

  The node D determines the destination information 52 of the communication frame 50 received from the node E. In this case, since the destination information 52 is not addressed to the node D, the node D refers to the communication path table 8 of the node D shown in FIG. Further, the node D predicts the total number of hops = 3 by adding the number of hops 53 = 2 to the destination stored in the communication path table 8 to the number of hops 53 = 1 of the created communication frame 50.

  Next, the node D obtains the remaining hop count = 0 by subtracting the total hop count = 3 from the maximum hop count = 3, the obtained remaining hop count = 0, and the transmission source information 51 of the created communication frame 50 = node A reception request including E is generated, and the reception request generated via the communication I / F 3 is transmitted to the selected relay station node B.

  When the node B receives the reception request, the node B determines the highest priority frame. Here, as shown in FIG. 12, the node B does not communicate with others and is free, so the communication frame 50 corresponding to the reception request transmitted from the node D is determined as the highest priority frame. Then, a notification indicating that communication is possible is transmitted to the node D. Upon receiving the notification that communication is possible, the node D adds 1 to the hop number 53 of the communication frame 50 to set the hop number 53 = 2, and transmits the communication frame 50 to the node B (node D → node B).

  The operation of each of the nodes A to E at the next time t4 will be described. The node E determines the destination information 52 of the communication frame 50 received from the node C. In this case, since the destination information 52 is addressed to the own node E, the node E predicts the number of hops 53 = 3 of the communication frame 50 received from the node C as the total number of hops = 3. Since the predicted total number of hops = 3 is the same as the maximum number of hops = 3, the node E delivers the communication data 54 of the communication frame 50 received from the node C to the application.

  The node B determines the destination information 52 of the communication frame 50 received from the node D. In this case, since the destination information 52 is not addressed to the node B, the node B refers to the communication path table 8 of the node B shown in FIG. 5 and selects the node A as the destination without the relay station.

  Next, the node B predicts a total hop count = 3, which is obtained by adding the hop count 53 = 1 to the destination stored in the communication path table 8 to the hop count 53 = 2 of the communication frame 50 transmitted from the node D. . Next, the node B obtains the remaining hop count = 0 by subtracting the total hop count = 3 from the maximum hop count = 3, and the obtained remaining hop count = 0 and the transmission source of the communication frame 50 transmitted from the node D Information 51 = A reception request including the node E is created, and the reception request created via the communication I / F 3 is transmitted to the selected destination node A.

  When the node A receives the reception request, the node A determines the highest priority frame. Here, as shown in FIG. 12, since the node A does not communicate with others and is free, the communication frame 50 corresponding to the reception request transmitted from the node B is determined as the highest priority frame. Then, a communication enable notification is transmitted to the node B. Upon receiving the notification that communication is possible, the node B adds 1 to the hop number 53 of the communication frame 50 to set the hop number 53 to 3, and transmits the communication frame 50 to the node A (node B → node A).

  The operation of each of the nodes A to E at the next time t5 will be described. The node A determines the destination information 52 of the communication frame 50 received from the node B. In this case, since the destination information 52 is addressed to the own node A, the node A predicts the hop number 53 = 3 of the communication frame 50 received from the node B as the total hop number = 3. Since the predicted total hop count = 3 is the same as the maximum hop count = 3, the node A delivers the communication data 54 of the communication frame 50 received from the node B to the application.

  As described above, when a plurality of communication frames 50 are received and transmitted as in the example of the node D at time t2, the communication priority is set based on the relationship between the number of remaining hops of the communication frame 50. Thus, the node E can receive the communication frame 50 from the node B at the time t4, and the node A can receive the communication frame 50 from the node E at the time t5, and can be delivered to the application in the order in which the communication data 54 is generated. In addition, no node A to E communicates at the same time.

  According to the above-described embodiment, when the communication control unit 12 determines that the communication frame 50 received by the data reception unit 4 is addressed to itself by the destination determination unit 10, the maximum hop stored in the maximum hop count storage unit 9. And the total hop count obtained by adding the hop count to the destination stored in the communication path table 8 to the hop count 53 included in the communication frame 50 received by the data receiving unit 4. If it is the same value as the maximum hop number, the communication data 54 of the communication frame 50 received by the data receiving unit 4 is transmitted to the application connected to itself, and if the total hop number is smaller than the maximum hop number, the maximum hop number The communication frame 50 is controlled to wait for the time obtained by subtracting the total number of hops from the number before being transmitted to the application.

  In other words, the time from transmission of the transmission data 54 from each communication node 20 to delivery to the application is made to match the maximum communication time of the mesh network, so that the arrival of the communication data 54 to the application even if the number of relays is different. The order is no longer different from the data generation order. In addition, the system, apparatus, software, and other applications that process the communication data 54 that has arrived do not need to manage the order of the communication data 54 and can be configured simply.

  Moreover, according to embodiment mentioned above, the communication confirmation part 13 has the number of remaining hops most among the number of remaining hops contained in the reception request transmitted from the other communication node 20, and the reception request transmitted from the own communication node 20. After determining the few communication frames 50 as the highest priority frame and transmitting a reception request, upon receiving a notification that communication is possible, the data transmission unit 6 transmits the communication frame 50 to the destination or relay destination communication node 20, and communication is not possible. When a notification is received, transmission of a reception request is repeated until a communication enable notification is received.

  Accordingly, the communication node 20 is not allowed to perform a plurality of transmissions and receptions at the same time, and the transmission and reception are not performed at the same time, and communication to an application can be performed without having each communication node 20 have a plurality of communication I / Fs The arrival order of the data 54 can be the generation order of the communication data 54.

  Further, according to the above-described embodiment, the communication confirmation unit 13 includes the number of remaining hops included in the reception request transmitted from the other communication node 20 and the number of remaining hops included in the reception request transmitted by the own communication node 20. Since the communication frame 50 corresponding to the reception request transmitted by the own communication node 20 is determined as the highest priority frame, the remaining hop count included in the reception request transmitted by the own communication node 20 and other communication Even when the number of remaining hops included in the reception request received from the node 20 is the same, the highest priority frame can be determined.

  Further, according to the above-described embodiment, the communication confirmation unit 13 has a plurality of reception requests received from the other communication nodes 20, and all of them have the same remaining hop count, or is transmitted by the own communication node 20. If there are a plurality of reception requests only and all have the same remaining hop count, the highest priority frame is determined based on the transmission source information 51. Therefore, there are only a plurality of reception requests received from other communication nodes 20, and all have the same remaining hop count. The highest priority frame can be determined even when the number is the number of hops, or when there are only a plurality of reception requests transmitted by the own communication node 20 and all have the same number of remaining hops.

  Further, according to the above-described embodiment, the communication frame 50 includes the number of hops 53 relayed after being transmitted by the transmission source communication node 20 as the communication time that has passed since the transmission by the transmission source communication node 20. The maximum hop count storage unit 9 stores in advance the maximum hop count in the mesh network as the maximum communication time in the mesh network, and the communication path table 8 stores all other hops connected to the mesh network from itself. As the communication time to the other communication node 20, the number of hops from itself to all other communication nodes 20 connected to the mesh network is stored in advance. As a result, the arrival order of the communication data 54 does not differ from the generation order of the communication data 54 even if the number of relays is different.

  Further, according to the above-described embodiment, when the communication confirmation unit 13 receives the notification that communication is possible, the communication frame 50 is incremented by the hop number 53 included in the communication frame 50 and the communication frame 50 is sent to the data transmission unit 6 as a destination or relay. Since transmission is performed to the previous communication node 20, the hop count 53 can be adjusted. In addition, when the communication confirmation unit 13 receives a notification that communication is not possible, the communication frame 50 is transmitted to itself by incrementing the number of hops 53 included in the communication frame 50. The hop number 53 can be adjusted, and the communication time can be counted with a simple configuration.

  Further, according to the above-described embodiment, when the total number of hops is smaller than the maximum number of hops, the communication confirmation unit 13 increments the hop number 53 of the communication frame 50 and transmits the communication frame 50 to itself. The number of hops 53 can be adjusted by the number of virtual transmissions / receptions inside, and the communication time can be counted with a simple configuration.

  According to the above-described embodiment, the transmission source information 51 is used as the data unique ID, but the present invention is not limited to this. For example, other information such as the type of communication data 54 may be used.

  Further, according to the above-described embodiment, the transmission source information 51, the destination information 52, and the hop number 53 are located at the head of the communication frame 50, but the present invention is not limited to this. Each communication node 20 constituting the communication network 1 can determine the arrangement with common recognition. Further, in addition to the transmission source information 51, the destination information 52, and the hop number 53 of the communication data 54, the communication frame 50 includes a place for storing the destination information using the relay to facilitate the communication relay process. May be.

  In the above-described embodiment, the procedure for confirming whether communication with the communication node 20 that is the communication partner is performed before transmitting the communication frame 50 is shown, but this method is not limited to this. For example, you may utilize methods, such as Unexamined-Japanese-Patent No. 2002-111773, WO2008 / 093424.

  Further, according to the above-described embodiment, when the communication frame 50 is transmitted to another communication node 20 or the own node 20 on the assumption that the communication speed between the communication nodes 20 is the same, the hop number 53 is set to 1. Only incremented. However, the present invention is not limited to this. For example, the present invention can be applied to the communication system 1 in which the communication speed between the communication nodes 20 is different.

  In this case, when transmitting the communication frame 50, the number of hops 53 may be incremented by the number corresponding to the communication speed between the communication node 20 on the transmission side and the communication node 20 on the reception side. Specifically, it is only necessary to increment 11 counts when the communication speed is 2 Mbps, 2 counts when the communication speed is 11 Mbps, and the hop number 53.

  Further, the above-described embodiments are merely representative forms of the present invention, and the present invention is not limited to the embodiments. That is, various modifications can be made without departing from the scope of the present invention.

1 communication system 4 data receiving unit (receiving means)
6 Data transmission part (transmission means)
8 Communication route table (communication condition storage means)
9 Maximum number of hops storage (communication condition storage means)
10 Destination determination unit (destination determination means)
12 Communication control unit (first communication control means)
13 Communication confirmation unit (reception request transmission means, priority determination means, communication confirmation means, second communication control means)
20 communication nodes 53 hop count (communication time that has elapsed since transmission by the communication node of the transmission source, number of relays of communication nodes relayed since transmission by the communication node of the transmission source)

Claims (7)

In a communication system comprising a mesh network having a plurality of communication nodes comprising a receiving means for receiving data and a transmitting means for transmitting data,
The receiving means transmits the data including the communication time that has elapsed since being transmitted by the destination and the source communication node,
Each of the plurality of communication nodes is
Communication condition storage means in which the maximum communication time in the mesh network and the communication time from itself to all the other communication nodes connected to the mesh network are stored in advance;
Destination determination means for determining whether the data is addressed to itself or another communication node based on the destination of the data received by the reception means;
When the data received by the receiving means is determined by the destination judging means to be addressed to itself, the maximum communication time stored in the communication condition storage means and the data sent from the communication node of the transmission source A comparison is made with an added value obtained by adding the communication time to the destination stored in the communication condition storage means to the elapsed communication time, and if the added value is the same value as the maximum communication time, it is connected to itself. When the data is transmitted to the application and the added value is smaller than the maximum communication time, the data is waited for the time obtained by subtracting the added value from the maximum communication time and then transmitted to the application. First communication control means for controlling;
A communication system, further comprising: Each of the plurality of communication nodes is
When the data received by the receiving unit is determined to be addressed to another communication node by the destination determining unit, a reception request including a subtraction time obtained by subtracting the added value from the maximum communication time is sent to the destination or the relay destination. A reception request transmission means for transmitting to the communication node;
Priority determination means for determining the data having the shortest subtraction time among the subtraction times included in the reception request transmitted from the other communication node and the reception request transmitted by the reception request transmission means, as the highest priority data;
A communication confirmation means for notifying the communication node that has transmitted the reception request of the highest priority data that communication is possible, and notifying the communication node that has requested the reception of data that is not the highest priority data;
After transmitting the reception request, upon receiving the communication enable notification, the transmission means transmits the data to the destination or relay destination communication node, and upon receiving the communication disable notification, receives the communication enable notification. Second communication control means for causing the reception request transmission means to repeat transmission of the reception request until
The communication system according to claim 1, further comprising: When the priority determination unit has the same subtraction time included in the reception request transmitted from the other communication node and the subtraction time included in the reception request transmitted by the reception request transmission unit, the reception request The communication system according to claim 2, wherein data corresponding to the reception request transmitted by the transmission means is determined as the highest priority data. The reception request transmitting means transmits a reception request further including an ID unique to the received data;
When the priority determination means has only a plurality of reception requests received from the other communication nodes and all have the same subtraction time, or there are only a plurality of reception requests to be transmitted by the reception request transmission means, all the same 4. The communication system according to claim 2, wherein when the time is a subtraction time, the highest priority data is determined based on the ID. 5. The data includes the number of relays of the communication node relayed since being transmitted by the source communication node, as the communication time elapsed since being transmitted by the source communication node,
In the communication condition storage means, the maximum number of relays in the mesh network is stored in advance as the maximum communication time in the mesh network, and as the communication time from itself to all the other communication nodes connected to the mesh network, The communication system according to any one of claims 2 to 4, wherein the number of relays from itself to all of the other communication nodes connected to the mesh network is stored in advance. When the second communication control unit receives the communication permission notification, the second communication control unit increments the number of relays transmitted from the transmission source communication node included in the data, and sends the data to the transmission unit. Alternatively, when the relay node is transmitted to the communication node and the communication failure notification is received, the relay number from the transmission source communication node included in the data is incremented and the data is addressed to itself. The communication system according to claim 5, wherein transmission is performed. The first communication control means, when the added value is smaller than the maximum number of relays, to increment the number of relays after being transmitted by the communication node of the transmission source, and to transmit the data to itself The communication system according to claim 5 or 6, wherein the communication system is characterized.

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