JP5246060B2 - Control method, control device, and storage medium - Google Patents

Description

  The present invention relates to a control method, a control device, and a storage medium.

  In recent years, research on ad hoc networks in which wireless terminals (for example, “nodes”) are interconnected in an autonomous distributed manner has been underway. In an ad hoc network, no access point is installed, and each node forms a communication path by relaying a packet received from an adjacent node to another adjacent node based on the communication path information.

  By the way, in an ad hoc network, the network environment frequently changes with changes in radio field intensity or movement of nodes. For this reason, each node connected to the ad hoc network performs communication path control before communicating with other nodes.

  For example, conventionally, each node performs communication path control by a technique called pure flooding. Specifically, each node transmits request control information (for example, “HELLO packet”) with the other node as the final destination for the purpose of confirming the communication path with the other node recognized by the node. . Then, each node that has received the HELLO packet determines whether or not the final destination is its own node. If the final destination is its own node, presence control information (for example, “ REGISTER packet ") is returned. On the other hand, if the final destination is not the local node, the HELLO packet is relayed to the adjacent node.

JP 2008-47984 A

  However, the above-described conventional method has a problem that the load on the network increases. That is, the source node that is the source of the HELLO packet must transmit HELLO packets as many as the number of other nodes that the node recognizes, and the more nodes increase, the more HELLO packets are loaded on the network. It was a factor.

  The disclosed technology has been made in view of the above, and an object thereof is to provide a control method, a control device, and a storage medium capable of suppressing a load on a network.

  In one aspect, a control method, a control device, and a storage medium disclosed in the present application receive request control information for requesting existence confirmation from another terminal in a network to which a plurality of terminals are connected. A control method for processing the request control information. The specific terminal includes a reception step of receiving request control information for requesting existence confirmation from another terminal. The specific terminal includes a relay step of relaying the request control information received in the reception step to a terminal different from the other terminals. In addition, the specific terminal identifies the source terminal that is the terminal that first transmitted the request control information from the request control information received in the reception step, and the identified terminal exists as the identified source terminal. A generation step of generating presence control information by setting as a final destination of presence control information indicating that the In addition, the specific terminal sets a predetermined standby time so as to be a relatively short time if the number of terminals that have passed through the communication path from the source terminal to the specific terminal is relatively large, and the set standby time An integration step of integrating the presence control information received from another terminal within the time and the presence control information generated by the generation step. The specific terminal includes a return step of transmitting the presence control information integrated in the integration step to the other terminal that has transmitted the request control information to the specific terminal.

  According to one aspect of the control method, the control device, and the storage medium disclosed in the present application, there is an effect that it is possible to suppress the load on the network.

FIG. 1 is a block diagram illustrating a configuration of a network system according to the first embodiment. FIG. 2 is a sequence diagram illustrating a processing procedure of the network system according to the first embodiment. FIG. 3 is a diagram for explaining the outline of the ad hoc network system according to the second embodiment. FIG. 4 is a block diagram illustrating a configuration of the ad hoc network system according to the second embodiment. FIG. 5A is a schematic diagram illustrating a packet and a routing table according to the second embodiment. FIG. 5B is a schematic diagram illustrating a packet and a routing table according to the second embodiment. FIG. 6 is a flowchart for explaining the entire processing procedure in the node. FIG. 7 is a flowchart for explaining routing table update processing. FIG. 8 is a flowchart for explaining the HELLO packet relay process. FIG. 9 is a flowchart for explaining a REGISTER packet return process. FIG. 10 is a flowchart for explaining processing for generating a REGISTER packet. FIG. 11A is a schematic diagram illustrating a packet and a routing table according to the third embodiment. FIG. 11B is a schematic diagram illustrating a packet and a routing table according to the third embodiment. FIG. 12 is a diagram illustrating a computer that executes a control program.

  Hereinafter, embodiments of a control method, a control apparatus, and a storage medium disclosed in the present application will be described. In addition, this invention is not limited by the following examples.

[Configuration of Network System in Embodiment 1]
First, the configuration of the network system according to the first embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a network system according to the first embodiment.

  As shown in FIG. 1, a plurality of terminals are connected to the network 1 in the first embodiment. Here, the specific terminal 10 is an arbitrary terminal, receives request control information for requesting existence confirmation from another terminal, and processes the request control information. The source terminal 20 is a terminal that first transmits request control information.

  As shown in FIG. 1, the specific terminal 10 includes a request control information reception unit 11, a request control information relay unit 12, a presence control information generation unit 13, a presence control information integration unit 14, and a presence control information return unit 15. With.

  The request control information receiving unit 11 receives request control information from another terminal.

  The request control information relay unit 12 relays the request control information received by the request control information receiving unit 11 to a terminal different from the terminal that transmitted the request control information to the specific terminal 10.

  The presence control information generation unit 13 identifies the source terminal 20 from the request control information received by the request control information reception unit 11. In addition, the presence control information generation unit 13 sets the identified transmission source terminal 20 as the final destination of presence control information indicating that the specific terminal 10 exists, and generates presence control information.

  The presence control information integration unit 14 sets a predetermined standby time so as to be a relatively short time if the number of terminals that have passed through the communication path from the transmission source terminal 20 to the specific terminal 10 is relatively large. Then, the presence control information integration unit 14 integrates the presence control information received from another terminal within the set standby time and the presence control information generated by the presence control information generation unit 13.

  The presence control information return unit 15 transmits the presence control information integrated by the presence control information integration unit 14 to the terminal that transmitted the request control information to the specific terminal 10.

[Processing Procedure of Network System in First Embodiment]
Next, the processing procedure of the network system according to the first embodiment will be described with reference to FIG. FIG. 2 is a sequence diagram illustrating a processing procedure of the network system according to the first embodiment.

  As shown in FIG. 2, the specific terminal 10 receives the request control information (step S1).

  The specific terminal 10 that has received the request control information relays the request control information to the terminal 30 (step S2).

  Here, the specific terminal 10 sets and sets a predetermined standby time so that the time is relatively short if the number of terminals that have passed through the communication path from the source terminal 20 to the specific terminal 10 is relatively large. Within the waiting time, presence control information is received from other terminals 30 (steps S3 and S4).

  And the specific terminal 10 produces | generates presence control information which shows that the specific terminal 10 exists, and integrates the produced | generated presence control information and the presence control information received from the other terminal within the set waiting time ( Step S5). Specifically, the specific terminal 10 identifies the source terminal 20 from the request control information received in step S1, and uses the identified source terminal 20 as the final presence control information indicating that the specific terminal 10 exists. The presence control information is generated by setting as a destination. Then, the specific terminal 10 integrates the generated presence control information with the presence control information received from another terminal.

  Thereafter, the specific terminal 10 transmits the integrated presence control information integrated in step S5 to the terminal 30 that has transmitted the request control information to the specific terminal 10 (step S6).

  In the first embodiment, the specific terminal 10 relays the request control information in step S2, and after the standby time has elapsed, the processing procedure for generating and integrating the presence control information in step S5 has been described. It is not limited to. For example, the process of generating the presence control information and the process of step S2 may be performed in parallel, and the process of integrating the presence control information may be performed after the standby time has elapsed.

[Effect of Example 1]
As described above, according to the first embodiment, the specific terminal 10 that has received the request control information relays the request control information to another terminal and returns the presence control information to the source terminal 20. In addition, the specific terminal 10 waits for a standby time that is set to be a relatively short time if the number of terminals that have passed through the communication path from the source terminal 20 to the specific terminal 10 is relatively large. The presence control information received from other terminals and the presence control information generated by the own terminal are integrated. In other words, if the distance from the source terminal 20 is short, the longer the specific terminal 10 is set, the longer the standby time is set, and the presence control information collected from the other terminals is collectively returned within the standby time to the source terminal 20. For this reason, the number of packets is reduced, and the network load can be suppressed.

[Outline of Ad Hoc Network System in Embodiment 2]
Subsequently, an ad hoc network system will be described as an embodiment of a control method, a control apparatus, and a storage medium disclosed in the present application. First, the outline of the ad hoc network system according to the second embodiment will be described with reference to FIG. FIG. 3 is a diagram for explaining the outline of the ad hoc network system according to the second embodiment.

  As shown in FIG. 3, at least a node X, a node Y, and a node Z are connected to the ad hoc network in the second embodiment. Here, the node Y and the node Z are arbitrary nodes, receive HELLO packets for requesting existence confirmation from other nodes, and process the HELLO packets. Node X is a transmission source node that first transmits a HELLO packet.

  As illustrated in FIG. 3, the node X transmits a HELLO packet, and the node Y receives the HELLO packet (step S10).

  The node Y that has received the HELLO packet relays the HELLO packet to the node Z different from the node X, and the node Z receives the HELLO packet (step S11). Further, the node Z that has received the HELLO packet relays the HELLO packet to a node different from the node Y (step S12).

  Here, the node Z sets a predetermined standby time so as to be a relatively short time if the number of terminals that have passed through the communication path from the node X to the node Z is relatively large, and within the set standby time The REGISTER packet is received from another node (step S13).

  Then, the node Z generates a REGISTER packet indicating that the node Z exists, and integrates the generated REGISTER packet with the REGISTER packet received from another node within the set waiting time (step S14). Specifically, the node Z identifies the node X as the transmission source node from the HELLO packet received in step S11, and sets the identified node X as the final destination of the REGISTER packet indicating that the node Z exists. A REGISTER packet is generated. Then, the node Z integrates the generated REGISTER packet and the REGISTER packet received from another node.

  Thereafter, the node Z transmits the integrated REGISTER packet integrated in step S14 to the node Y that transmitted the HELLO packet to the node Z (step S15).

  On the other hand, the node Y sets a predetermined waiting time to be a relatively short time if the number of terminals that have passed through the communication path from the node X to the node Y is relatively large, and within the set waiting time, A REGISTER packet is received from another node (step S16). Here, comparing the standby time set by the node Z with the standby time set by the node Y, it can be seen that the standby time set by the node Z is relatively shorter as shown in FIG. .

  Then, the node Y generates a REGISTER packet indicating that the node Y exists, and integrates the generated REGISTER packet with the REGISTER packet received from another node within the set waiting time (step S17). Specifically, the node Y identifies the node X as the transmission source node from the HELLO packet received in step S10, and sets the identified node X as the final destination of the REGISTER packet indicating that the node Y exists. A REGISTER packet is generated. Then, the node Y integrates the generated REGISTER packet and the REGISTER packet received from the node Z.

  Thereafter, the node Y transmits the integrated REGISTER packet integrated in step S17 to the node X that transmitted the HELLO packet to the node Y (step S18).

  For this reason, according to the second embodiment, the node Y that has received the HELLO packet relays the HELLO packet to another node Z and returns a REGISTER packet to the node X. In addition, the node Y waits for a standby time that is set to be a relatively short time if the number of nodes that have passed through on the communication path from the transmission source node to the own node is relatively large, while other nodes wait The REGISTER packet received from the node and the REGISTER packet generated by the own node are integrated. In other words, the longer the distance from the transmission source node, the longer the standby time is set, and the REGISTER packets collected from other nodes are collectively returned within the standby time to the transmission source node. For this reason, the number of packets is reduced, and the network load can be suppressed.

[Configuration of Ad Hoc Network System in Embodiment 2]
Next, the configuration of the ad hoc network system according to the second embodiment will be described with reference to FIGS. 4, 5-1, and 5-2. FIG. 4 is a block diagram illustrating a configuration of the ad hoc network system according to the second embodiment. FIGS. 5A and 5B are diagrams for explaining a packet and a routing table according to the second embodiment.

  As illustrated in FIG. 4, the node 100 includes a communication unit 110, a storage unit 120, and a control unit 130.

  The communication unit 110 is a wireless module and an antenna that can perform wireless communication.

  The storage unit 120 stores data used for various processes by the control unit 130, and particularly includes a routing table unit 121 and a work data unit 122.

  The routing table unit 121 stores communication path information. Here, the communication path information is information indicating a communication path when a packet is transmitted to a destination node. In other words, the communication path information is information indicating a correspondence relationship between a node that is a packet destination and a node that relays the packet. In addition to the information indicating the correspondence relationship, the routing table unit 121 manages quality information indicating the quality of the communication path, an FID (Frame ID) for uniquely identifying the packet from which the communication path information has been acquired, and a waiting time. Memorize the timer.

  Specifically, the routing table unit 121 stores communication path information by being updated by a routing table updating unit 132 described later when a packet is received by a packet receiving unit 131 described later. The communication path information stored in the routing table unit 121 is used for processing by a HELLO packet relay unit 133 described later, processing by a REGISTER packet return unit 135, and the like.

  For example, as illustrated in FIG. 5A, the routing table unit 121 stores communication path information (indicated as “routing table” in FIGS. 5A and 5B). That is, the routing table unit 121 includes a destination node (“destination”) indicating a node that is a packet destination, and an adjacent node (“adjacent”) indicating a node that interconnects with the own node among nodes that relay packets. Are stored in association with each other. The routing table unit 121 also includes a communication path quality (“quality”) for transmitting / receiving packets to / from the destination node, a FID (“FID”) for uniquely identifying the packet from which the communication path information has been acquired, and a standby A timer for managing time (“timer”) is stored in association with each other. Here, the quality is a value calculated from the number of hops, for example. The timer is a value calculated by subtracting the number of hops from a preset maximum value, and is a value calculated by subtracting “1” every time.

  Specifically, for example, as shown in S102 of FIG. 5A, the routing table unit 121 includes a destination node “W”, a quality “1”, an adjacent node “W”, and an FID “1”. The communication path information of timer “3” is stored. That is, the routing table unit 121 stores that there is a communication path to be transmitted to the adjacent node “W” when the packet is transmitted with the node “W” as the destination, and the quality of the path is “1”. Further, the routing table unit 121 stores that the FID for uniquely identifying the packet from which the communication path information has been acquired is “1”, and that the standby time is “3” at the present time.

  The work data unit 122 has a storage area having the same structure as the routing table unit 121, the HELLO packet, and the REGISTER packet. The work data unit 122 temporarily stores indeterminate communication path information before being stored in the routing table unit 121, and temporarily stores indeterminate information when generating a HELLO packet and a REGISTER packet.

  The control unit 130 controls the node 100 to execute various processes. In particular, the control unit 130 includes a packet reception unit 131, a routing table update unit 132, a HELLO packet relay unit 133, a REGISTER packet integration unit 134, and a REGISTER packet return unit 135.

  The packet receiving unit 131 receives a HELLO packet or a REGISTER packet from another node. Specifically, when the packet receiving unit 131 receives a packet from an adjacent node via the communication unit 110, the packet receiving unit 131 determines whether the received packet is a HELLO packet, a REGISTER packet, or a normal data packet. To do.

  When the packet reception unit 131 determines that the received packet is a HELLO packet or a REGISTER packet, the packet reception unit 131 sends the received packet to the routing table update unit 132. On the other hand, when it is determined that the received packet is a normal data packet, normal data packet processing is performed, and the processing ends.

  The routing table update unit 132 updates communication path information (routing table) stored by the routing table unit 121. Specifically, when receiving the HELLO packet or the REGISTER packet from the packet receiving unit 131, the routing table updating unit 132 refers to the routing table using an FID that uniquely identifies the HELLO packet or the REGISTER packet. Then, the routing table update unit 132 determines whether or not a FID that matches the FID included in the HELLO packet or the REGISTER packet exists in the routing table. The routing table update unit 132 performs a routing table update process when it is determined that it does not exist, and ends the process as it is when it is determined that it exists.

  In addition, when the routing table update unit 132 performs the routing table update process for the HELLO packet, the routing table update unit 132 then sends the HELLO packet to the HELLO packet relay unit 133. On the other hand, when the routing table update unit 132 performs the routing table update process for the REGISTER packet, the routing table update unit 132 then sends the REGISTER packet to the REGISTER packet integration unit 134. The routing table update process will be described in detail when explaining the processing procedure.

  The HELLO packet relay unit 133 relays the HELLO packet to other nodes. Specifically, when the HELLO packet relay unit 133 receives a HELLO packet from the routing table update unit 132, the HELLO packet relay unit 133 performs a HELLO packet relay process. When the HELLO packet relay unit 133 performs the HELLO packet relay process, the HELLO packet relay unit 133 then sends the HELLO packet received from the routing table update unit 132 to the REGISTER packet integration unit 134. The HELLO packet relay process will be described in detail when the processing procedure is described.

  The REGISTER packet integration unit 134 generates a REGISTER packet to be returned to the transmission source node of the HELLO packet, and integrates the generated REGISTER packet and the REGISTER packet received from another node within the standby time. Specifically, the REGISTER packet integration unit 134 waits until the timer of the routing table managed by the routing table unit 121 becomes “0”, and when the timer becomes “0”, the REGISTER packet generation processing (integration processing is performed). After that, the integrated REGISTER packet is sent to the REGISTER packet reply unit 135. The REGISTER packet generation processing will be described in detail when the processing procedure is described.

  The REGISTER packet return unit 135 returns the integrated REGISTER packet to the transmission source node of the HELLO packet. Specifically, when the REGISTER packet reply unit 135 receives the REGISTER packet from the REGISTER packet integration unit 134, the REGISTER packet return unit 135 transmits the REGISTER packet, and then ends the processing.

[Processing Procedure of Ad Hoc Network System in Embodiment 2]
Next, the processing procedure of the ad hoc network system according to the second embodiment will be described with reference to FIGS. FIGS. 5A and 5B are diagrams for explaining a packet and a routing table according to the second embodiment.

[Overall procedure in the node]
First, the entire processing procedure in the node will be described with reference to FIG. FIG. 6 is a flowchart for explaining the entire processing procedure in the node.

  As shown in FIG. 6, in the node 100, the packet receiver 131 receives a packet (step S201).

  Here, the HELLO packet is a packet having a structure as shown in FIG. Specifically, a transmission source node (“transmission source”) indicating the node that first transmitted the HELLO packet, a hop number (“hop count”) indicating the quality of the communication path from the transmission source node, an adjacent node (“adjacent” )) And a FID (“FID”) for uniquely identifying the HELLO packet. That is, for example, in the HELLO packet transmitted by the node X in step S101, the node “W” is the transmission source node, the hop count from the transmission source node W is “1”, and the adjacent node is the own node “W” ", And the FID includes information indicating" 1 ".

  The REGISTER packet is a packet having a structure as shown in FIG. Specifically, it has a transmission source node (“transmission source”) indicating the node that first transmitted the REGISTER packet, and a hop count (“hop count”) indicating the quality of the communication path from the transmission source node. In addition, a destination node (“destination”) indicating a node that is a final destination of the REGISTER packet, an adjacent node (“adjacent”), and a FID (“FID”) for uniquely identifying the REGISTER packet are included. That is, for example, the REGISTER packet transmitted by the node Z in step S108 includes information indicating that the node “Z” is the transmission source node and the hop count from the transmission source node Z is “1”. In addition, information indicating that the node as the final destination is the node “W”, the adjacent node is the local node “Z”, and the FID is “1”.

  Then, the packet reception unit 131 determines whether the received packet is a HELLO packet (step S202), a REGISTER packet (step S207), or a normal data packet.

  If it is determined that the received packet is a HELLO packet (Yes at step S202), the packet receiving unit 131 sends the received packet to the routing table updating unit 132.

  Then, the routing table update unit 132 refers to the routing table using the FID included in the HELLO packet, and determines whether there is an FID that matches the FID included in the HELLO packet (step S203). .

  When it is determined that there is a matching FID (No at Step S203), the routing table update unit 132 ends the process as it is. On the other hand, when it is determined that there is no matching FID (Yes at Step S203), the routing table update unit 132 performs a routing table update process described later (Step S204). Send to.

  Then, the HELLO packet relay unit 133 determines whether or not the number of hops is a preset MAX value (step S205), and if it is the MAX value (Yes in step S205), the process is ended as it is. That is, in the ad hoc network according to the second embodiment, the MAX value is set for the number of hops so that the HELLO packet is not relayed indefinitely.

  On the other hand, if it is not the MAX value (No at Step S205), the HELLO packet relay unit 133 performs a HELLO packet relay process described later (Step S206), and then ends the process.

  On the other hand, when it is determined in step S202 that the received packet is not a HELLO packet (No in step S202), the packet receiver 131 next determines whether or not the received packet is a REGISTER packet (step S202). S207).

  If it is determined that the received packet is a REGISTER packet (Yes at step S207), the packet receiving unit 131 sends the received packet to the routing table updating unit 132.

  Then, the routing table update unit 132 refers to the routing table using the FID included in the REGISTER packet, and determines whether there is an FID that matches the FID included in the REGISTER packet (step S208). .

  When it is determined that there is a matching FID (No at Step S208), the routing table update unit 132 ends the process as it is. On the other hand, if it is determined that there is no matching FID (Yes at Step S208), the routing table update unit 132 performs a routing table update process described later (Step S209), and then transmits the REGISTER packet to the REGISTER packet integration unit 134. Send to.

  Then, the REGISTER packet integration unit 134 first determines whether or not the destination of the REGISTER packet is the local node (step S210). If it is determined that the node is the own node (No at step S210), the process is terminated as it is.

  On the other hand, when it is determined that the node is not the own node (Yes in step S210), the REGISTER packet integration unit 134 sets a work packet as a temporary storage area having the same structure as the REGISTER packet in the work data unit 122. Then, the REGISTER packet integration unit 134 copies the REGISTER packet to the set work packet (step S211), and then ends the process.

  On the other hand, if it is determined in step S207 that the received packet is not a REGISTER packet (No in step S207), the packet receiver 131 determines that the received packet is a normal data packet, and performs normal data packet processing. (Step S212), and the process ends.

[Routing table update processing]
Next, routing table update processing will be described with reference to FIG. FIG. 7 is a flowchart for explaining routing table update processing. Note that the routing table update processing is almost the same between the case of updating using the HELLO packet and the case of updating using the REGISTER packet, and the case of updating using the HELLO packet will be described below.

  The routing table update unit 132 first identifies the transmission source node from the HELLO packet (step S204-1). For example, the routing table updating unit 132 of the node X illustrated in FIG. 5A identifies the transmission source node “W” from the HELLO packet received in step S101.

  Next, the routing table update unit 132 sets a work table as a temporary storage area having the same structure as the routing table in the work data unit 122, and newly creates a record in the set work table (step S204-2). ).

  Subsequently, the routing table update unit 132 sets the transmission source node identified in step S204-1 to the “destination” of the newly created record in the work table (step S204-3). For example, the routing table update unit 132 sets the transmission source node “W” to “destination” of the newly created record in the work table.

  Further, the routing table update unit 132 identifies the adjacent node from the received HELLO packet, and sets the identified adjacent node in “adjacent” of the newly created record in the work table (step S204-4). For example, the routing table updating unit 132 identifies the adjacent node “W” from the HELLO packet received in step S101, and sets the identified adjacent node “W” in “adjacent” of the newly created record in the work table.

  Also, the routing table update unit 132 identifies the number of hops from the received HELLO packet, and sets the identified number of hops in the “quality” of the newly created record in the work table (step S204-5). For example, the routing table updating unit 132 identifies the hop number “1” from the HELLO packet received in step S101, and sets the identified hop number “1” as the “quality” of the newly created record in the work table.

  Further, the routing table update unit 132 identifies the FID from the received HELLO packet, and sets the identified FID in “FID” of the newly created record in the work table (step S204-6). For example, the routing table updating unit 132 identifies the FID “1” from the HELLO packet received in step S101, and sets the identified FID “1” to “FID” of the newly created record in the work table.

  Subsequently, the routing table update unit 132 determines whether or not the HELLO packet is a REGISTER packet (step S204-7). If it is a REGISTER packet (Yes at Step S204-7), the routing table update unit 132 sets “0” to “Timer” of the newly created record in the work table (Step S204-8). On the other hand, when the packet is not a REGISTER packet (No at Step S204-7), the routing table update unit 132 calculates a timer value by subtracting the hop count from the preset MAX value of the timer. Then, the routing table update unit 132 sets the calculated timer value in the “timer” of the newly created record in the work table (step S204-9). For example, the routing table updating unit 132 of the node X illustrated in FIG. 5A identifies the hop number “1” from the HELLO packet received in step S101, and subtracts the hop number “1” from the MAX value “4” of the timer. Thus, the timer value “3” is calculated. Then, the routing table updating unit 132 sets the calculated timer value “3” as the “timer” of the newly created record in the work table.

  As described above, the timer value is calculated by subtracting the number of hops from the MAX value of the timer, so that the longer the distance from the transmission source node, the longer the standby time is set.

  After step S204-8 or after step S204-9, the routing table update unit 132 determines whether or not the same “destination” and “adjacent” records exist in the routing table (step S204-10). If there is (Yes at Step S204-10), the routing table updating unit 132 overwrites the routing table with the newly created record in the work table (Step S204-11), and ends the process. For example, the routing table updating unit 132 of the node X illustrated in FIG. 5A updates the routing table as illustrated in Step S102 from the HELLO packet received in Step S101.

  On the other hand, if not (No at Step S204-10), the routing table updating unit 132 adds a newly created record to the work table to the routing table (Step S204-12), and ends the process.

[Relay processing of HELLO packet]
Next, HELLO packet relay processing will be described with reference to FIG. FIG. 8 is a flowchart for explaining the HELLO packet relay process.

  First, the HELLO packet relay unit 133 sets a work packet as a temporary storage area having the same structure as the HELLO packet in the work data unit 122, and copies the received HELLO packet to the set work packet (step S205). -1). For example, the HELLO packet relay unit 133 of the node Z illustrated in FIG. 5A copies the HELLO packet received in step S101 to the work packet.

  Next, the HELLO packet relay unit 133 adds 1 to the “hop count” copied to the work packet and sets a new hop count (step S <b> 205-2). For example, the HELLO packet relay unit 133 sets a new hop number “2” in the work packet.

  Further, the HELLO packet relay unit 133 sets its own node to “adjacent” copied to the work packet (step S205-3). For example, the HELLO packet relay unit 133 sets its own node “X” to “adjacent”.

  Further, the HELLO packet relay unit 133 sets “FID” as it is to “FID” copied to the work packet (step S205-4). For example, the HELLO packet relay unit 133 sets FID “1” to “FID”.

  Then, the HELLO packet relay unit 133 generates a new HELLO packet, and sets the contents of the work packet in the generated new HELLO packet (step S205-5).

  Thereafter, the HELLO packet relay unit 133 transmits the HELLO packet generated in step S205-5 (step S205-6). For example, the HELLO packet relay unit 133 of the node X illustrated in FIG. 5A transmits the generated HELLO packet to the node Y (see step S103).

[Register packet reply processing]
Next, the REGISTER packet return process will be described with reference to FIG. FIG. 9 is a flowchart for explaining a REGISTER packet return process.

  The REGISTER packet integration unit 134 determines whether there is a clock event (step S301). If there is no clock event (No at step S301), the REGISTER packet integration unit 134 returns to the process of determining whether there is a clock event.

  When there is a clock event (Yes in step S301), the REGISTER packet integration unit 134 subtracts “1” from each timer value stored in the routing table unit 121, and stores the timer value after subtraction (step S302). .

  Then, the REGISTER packet integration unit 134 determines whether or not all the timer values are “0” (step S303). If the timer value is not “0” (No in step S303), the clock event is again determined. It returns to the process which determines whether there exists.

  On the other hand, when it becomes “0” (Yes at Step S303), the REGISTER packet integration unit 134 performs a REGISTER packet generation process described later (Step S304), and then converts the integrated REGISTER packet to the REGISTER packet return unit 135. Send to.

  Then, the REGISTER packet reply unit 135 transmits the integrated REGISTER packet received from the REGISTER packet integration unit 134 (step S305). For example, the REGISTER packet return unit 135 of the node X illustrated in FIGS. 5A and 5B waits until the timer “3” that has started standby in Step S102 becomes “0” in Step S113. The transition of the routing table from step S112 to step S113 indicates waiting until the timer becomes “0”. Then, the REGISTER packet reply unit 135 integrates the REGISTER packets received in step S111 within the waiting time, and transmits the integrated REGISTER packets to the node W in step S114.

  As shown in FIGS. 5A and 5B, the other nodes Y and Z similarly wait for a predetermined time, and receive REGISTER packets received within the waiting time, and REGISTER packets generated by the own node. And a REGISTER packet is returned.

[REGISTER packet generation processing]
Next, REGISTER packet generation processing will be described with reference to FIG. FIG. 10 is a flowchart for explaining processing for generating a REGISTER packet.

  The REGISTER packet integration unit 134 generates a new field of the new REGISTER packet in order to generate a new REGISTER packet (step S304-1). For example, the REGISTER packet reply unit 134 of the node X illustrated in FIG. 5B generates empty fields of “transmission source”, “hop count”, “destination”, “adjacent”, and “FID”.

  Next, the REGISTER packet integration unit 134 sets the own node in the empty field “source” (step S304-2). For example, the REGISTER packet integration unit 134 sets its own node “X” as “transmission source”.

  Further, the REGISTER packet integration unit 134 sets 1 to the empty field “hop count” (step S304-3).

  Further, the REGISTER packet integration unit 134 sets the transmission source node of the HELLO packet in the empty field “destination” (step S304-4). For example, the REGISTER packet integration unit 134 of the node X illustrated in FIG. 5B sets the transmission source node “W” identified in the routing table update processing for the HELLO packet received in step S101.

  Further, the REGISTER packet integration unit 134 sets its own node in the empty field “adjacent” (step S304-5). For example, the REGISTER packet integration unit 134 sets its own node “X” to “adjacent”.

  Further, the REGISTER packet integration unit 134 sets “FID” of the HELLO packet in the empty field “FID” (step S304-6). For example, the REGISTER packet integration unit 134 of the node X illustrated in FIG. 5B sets the FID “1” included in the HELLO packet received in step S101.

  Subsequently, the REGISTER packet integration unit 134 determines whether or not there is a copy of the REGISTER packet in the work packet of the work data unit 122 (step S304-7).

  If there is no copy (No at Step S304-7), the REGISTER packet integration unit 134 ends the generation process as it is, and sends the generated REGISTER packet to the REGISTER packet return unit 135.

  On the other hand, if there is a copy (Yes at Step S304-7), the REGISTER packet integration unit 134 adds 1 to the “hop count” copied to the work packet and sets a new hop count (Step S304-8). ). For example, the REGISTER packet relay unit 135 of the node X illustrated in FIG. 5B sets a new hop number “3” in the work packet when the work packet includes a copy of the REGISTER packet whose source is the node Z.

  Further, the REGISTER packet integration unit 134 sets its own node to “adjacent” copied to the work packet (step S304-9). For example, the REGISTER packet relay unit 135 of the node X illustrated in FIG. 5B sets its own node “X” to “adjacent”.

  Further, the REGISTER packet integration unit 134 sets “FID” as it is to “FID” copied to the work packet (step S304-10). For example, the REGISTER packet integration unit 134 of the node X illustrated in FIG. 5B sets FID “1” to “FID”. The REGISTER packet relay unit 135 does not change the “transmission source” and “destination” copied to the work packet.

  Then, the REGISTER packet integration unit 134 integrates the REGISTER packet by adding the contents of the work packet to the new REGISTER packet (step S304-11). For example, the REGISTER packet integration unit 134 of the node X illustrated in FIG. 5B, as illustrated in step S114, the transmission source “Z”, the number of hops “3”, the destination “W”, the adjacent “X”, and the FID “1”. The REGISTER packet of the transmission source “X”, the number of hops “1”, the destination “W”, the adjacent “X”, and the FID “1” are integrated.

  Thereafter, the REGISTER packet integration unit 134 returns to the process of determining whether or not there is a copy of the REGISTER packet in the work packet. In the case of the REGISTER packet integration unit 134 of the node X shown in FIG. 5B, since the work packet further includes a copy of the REGISTER packet whose transmission source is the node Y, the REGISTER packet is also integrated.

[Effect of Example 2]
As described above, according to the second embodiment, when an arbitrary node in an ad hoc network to which a plurality of nodes are connected receives a HELLO packet for confirmation of existence from another node, the received HELLO packet is transferred to another node. Relay to a node different from the node. The node also identifies the source node that is the node that first transmitted the HELLO packet from the received HELLO packet, and sets the identified source node as the final destination of the REGISTER packet indicating that the node exists. To generate a HELLO packet. In addition, the node sets a predetermined standby time so that a relatively short time is set if the number of nodes that have passed through the communication path from the transmission source node to the own node is relatively large, and within the set standby time. The REGISTER packet received from another node is integrated with the generated REGISTER packet. Then, the node transmits the integrated REGISTER packet to the other node that transmitted the HELLO packet to its own node.

  For this reason, according to the second embodiment, the node that has received the HELLO packet relays the HELLO packet to another node and returns a REGISTER packet. In addition, the node waits for a standby time that is set to be a relatively short time if the number of nodes that have passed through the communication path from the transmission source node to the own node is relatively large, and from other nodes during that time The received REGISTER packet is integrated with the REGISTER packet generated by the own node. In other words, the longer the distance from the transmission source node, the longer the standby time is set, and the REGISTER packets collected from other nodes are collectively returned within the standby time to the transmission source node. For this reason, the number of packets is reduced, and the network load can be suppressed.

  Further, as described in the second embodiment, each node returns a REGISTER packet regardless of whether or not the final destination of the HELLO packet is set. That is, each node returns a REGISTER packet even if the final destination of the HELLO packet is not set in the HELLO packet. On the other hand, even when the final destination of the HELLO packet is set, each node returns a REGISTER packet regardless of whether or not the own node is set as the final destination of the HELLO packet.

  Further, as described in the second embodiment, each node stores the FID included in the received HELLO packet in the routing table. Then, each node determines whether or not a FID that matches the FID included in the received HELLO packet exists in the routing table, and if it exists, does not relay the HELLO packet to another node. For this reason, according to the second embodiment, it is possible to prevent a situation in which the same HELLO packet is continuously relayed.

  Next, the ad hoc network system according to the third embodiment will be described with reference to FIGS. 11A and 11B. FIGS. 11A and 11B are diagrams for explaining a packet and a routing table according to the third embodiment. In FIGS. 11A and 11B, it is assumed that the timer MAX value is “6”.

  The ad hoc network according to the third embodiment assumes that a plurality of communication paths exist between a transmission source node and a predetermined node. Therefore, each node may receive a plurality of REGISTER packets indicating that the same node exists from a plurality of communication paths. Therefore, when receiving a plurality of REGISTER packets from a plurality of communication paths, each node according to the third embodiment selects a REGISTER packet corresponding to the highest quality communication path, and generates the selected REGISTER packet and its own node. Are integrated with the REGISTER packet.

  For example, in the examples of FIGS. 11A and 11B, as the communication path from the transmission source node W to the node Z, the communication path from the node W to the node X to the node Z and the node W to the node X to the node Y to There is a communication path for node Z. For this reason, the node X may relay the HELLO packet directly to the node Z as shown in step S203-1.

  The node Z updates the routing table in step S204 based on the HELLO packet received in step S203-1, and relays the HELLO packet in step S205. Node Z also receives the HELLO packet in step S207. As shown in FIG. 11A, the HELLO packet is relayed from the node X to the node Y in step S203-2 and then relayed from the node Y to the node Z.

  As described above, in the third embodiment, the node Z receives the HELLO packet relayed directly from the node X and the HELLO packet relayed via the node Y. Therefore, the node Z transmits a REGISTER packet to each of the node X and the node Y, as shown in step S209 and step S211 in FIG.

  As in the second embodiment, the node X in the third embodiment also waits until the timer becomes “0”. For example, the process waits until the timer managed by the routing table shown in step S214 in FIG. When the timer becomes “0”, the node X performs integration of REGISTER packets as in the second embodiment, but in the third embodiment, selects the REGISTER packet corresponding to the highest quality communication path. Then, only the selected REGISTER packet is targeted for integration.

  For example, as illustrated in FIG. 11B, the node X receives the REGISTER packet having the node Z as a transmission source twice in steps S209 and S213. One is a REGISTER packet having a transmission source “Z”, a hop count “1”, a destination “W”, an adjacent “Z”, and an FID “1”. The other is a REGISTER packet with a transmission source “Z”, a hop count “2”, a destination “W”, an adjacent “Y”, and an FID “1”.

  Here, the node X in the third embodiment compares the number of hops of both REGISTER packets, and selects the REGISTER packet having a smaller hop number as the REGISTER packet corresponding to the communication path with the highest quality. For example, the node X selects a REGISTER packet having a transmission source “Z”, a hop number “1”, a destination “W”, an adjacent “Z”, and an FID “1”.

  As a result, as shown in step S215 of FIG. 11-2, the node X does not integrate two REGISTER packets originating from the node Z, but integrates only one selected REGISTER packet. . Note that the hop count of the REGISTER packet originating from the node Z is “2”. When the node X integrates REGISTER packets received from other nodes, the hop count is set to “1”. It is because it adds.

  For this reason, according to the third embodiment, even when there are a plurality of communication paths between the transmission source node and the predetermined node, the REGISTER packet corresponding to the communication path with the highest quality is selected. As a result of the integration, a REGISTER packet with low value as information is not transmitted, and the load on the network is further reduced.

  Although some of the embodiments have been described in detail with reference to the drawings, these are only examples, and various modifications and improvements can be made based on the knowledge of those skilled in the art including the aspects described in the column of the disclosure of the invention. It is possible to implement the present invention in other forms.

[Computer]
In the various processes described in the above embodiments, a program prepared in advance is stored in a storage medium such as a flexible disk (FD), a CD-ROM, an MO disk, a DVD disk, a magneto-optical disk, and an IC card. Can be realized by reading and executing the program from the storage medium. In the following, an example of a computer that reads and executes a control program having the same function as that of the above embodiment from a storage medium will be described with reference to FIG. FIG. 12 is a diagram illustrating a computer that executes a control program.

  As shown in FIG. 12, the control program (computer) 40 is a bus for a cache 41, a RAM (Random Access Memory) 42, an HDD (Hard Disk Drive) 43, a ROM (Read Only Memory) 44 and a CPU (Central Processing Unit) 45. 46 is connected. Here, the computer 40 reads the control program from the storage medium, and stores the request control information reception program 44a, the request control information relay program 44b, the presence control information generation program 44c, the presence control information integration program 44d, and the presence control information in the ROM 44. A reply program 44e is stored.

  Then, the CPU 45 reads out and executes these programs 44a to 44e, so that each program 44a to 44e has a request control information reception process 45a, a request control information relay process 45b, and presence control information as shown in FIG. A generation process 45c, a presence control information integration process 45d, and a presence control information return process 45e. Each of the processes 45a to 45e includes a request control information receiving unit 11, a request control information relay unit 12, a presence control information generating unit 13, a presence control information integrating unit 14, and a presence control information returning unit 15 shown in FIG. Correspond to each.

DESCRIPTION OF SYMBOLS 1 Network 10 Specific terminal 11 Request control information receiving part 12 Request control information relay part 13 Presence control information generation part 14 Presence control information integration part 15 Presence control information reply part 20 Source terminal 30 Terminal 100 Node 110 Communication part 120 Storage part 121 Routing table section 122 Work data section 130 Control section 131 Packet receiving section 132 Routing table update section 133 HELLO packet relay section 134 REGISTER packet integration section 135 REGISTER packet return section

Claims (8)

An arbitrary specific terminal in a network to which a plurality of terminals are connected receives request control information for requesting existence confirmation from another terminal, and processes the request control information.
A specific device
A receiving step of receiving request control information for requesting existence confirmation from another terminal;
Relaying the request control information received in the receiving step to a terminal different from the other terminals;
Presence control that identifies the source terminal that is the terminal that first transmitted the request control information from the request control information received in the reception step, and indicates that the specific terminal exists as the identified source terminal A generation step for generating presence control information by setting as a final destination of information;
If the number of terminals that have passed through the communication path from the source terminal to the specific terminal is relatively large, a predetermined waiting time is set so that the time is relatively short, and the other terminals are set within the set waiting time. An integration step of integrating the presence control information received from the presence control information generated by the generation step;
A control method comprising: a return step of transmitting presence control information integrated in the integration step to the other terminal that has transmitted the request control information to the specific terminal.   In the integration step, when a plurality of presence control information indicating that the same terminal exists is received from a plurality of communication paths, the presence control information corresponding to the communication path with the highest quality is selected, and the selected presence control is selected. The control method according to claim 1, wherein the information and the presence control information generated by the generation step are integrated.   The control method according to claim 1, wherein a final destination of the request control information is not set in the request control information. In the request control information, a final destination of the request control information is set,
The specific terminal is
2. The control method according to claim 1, wherein, in the reply step, the presence control information is transmitted regardless of whether or not a local node is set as a final destination of the request control information. The specific terminal is
In the reception step, storing identification information for uniquely identifying the request control information included in the received request control information in a storage table;
In the relay step, the storage table is referenced to determine whether or not identification information that matches the identification information included in the received request control information exists in the storage table. The control method according to claim 1, wherein the control information is not relayed to the different terminal. As a specific terminal in a network to which a plurality of terminals are connected, a control apparatus that receives request control information for requesting existence confirmation from another terminal and processes the request control information,
A receiving unit for receiving request control information for requesting existence confirmation from another terminal;
A relay unit that relays the request control information received by the receiving unit to a terminal different from the other terminals;
Presence control that identifies the source terminal that is the terminal that first transmitted the request control information from the request control information received by the receiving unit, and indicates that the specific terminal exists as the identified source terminal A generation unit configured to generate presence control information by setting as a final destination of information;
If the number of terminals that have passed through the communication path from the source terminal to the specific terminal is relatively large, a predetermined waiting time is set so that the time is relatively short, and the other terminals are set within the set waiting time. An integration unit that integrates the presence control information received from the presence control information generated by the generation unit;
A control apparatus comprising: a reply unit that transmits presence control information integrated by the integration unit to the other terminal that transmits the request control information to the specific terminal.   When the integration unit receives a plurality of presence control information indicating that the same terminal exists from a plurality of communication paths, the integration unit selects the presence control information corresponding to the highest quality communication path, and selects the selected presence control. The control apparatus according to claim 6, wherein the information and the presence control information generated by the generation step are integrated. An arbitrary specific terminal in a network to which a plurality of terminals are connected is a storage medium that stores request control information for requesting existence confirmation from another terminal and stores a control program for processing the request control information,
A specific device
A reception procedure for receiving request control information for requesting existence confirmation from another terminal,
A relay procedure for relaying the request control information received by the reception procedure to a terminal different from the other terminals;
Presence control that identifies the source terminal that is the terminal that first transmitted the request control information from the request control information received by the reception procedure, and indicates that the specific terminal exists as the identified source terminal A generation procedure for generating presence control information by setting as the final destination of the information;
If the number of terminals that have passed through the communication path from the source terminal to the specific terminal is relatively large, a predetermined waiting time is set so that the time is relatively short, and the other terminals are set within the set waiting time. An integration procedure for integrating the presence control information received from the presence control information generated by the generation procedure;
A storage medium for storing a control program, which executes a return procedure for transmitting presence control information integrated by the integration procedure to the other terminal that has transmitted the request control information to the specific terminal.

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