JP2015097346A - Node device, node control program, and network topology control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique that controls network topology of a constructed radio communication network.SOLUTION: A node device that constructs a radio communication network by wirelessly communicating with an adjacent node device comprises: a storage unit that stores first subgroup identification information that is identification information to identify a subgroup to determine a group formed in a radio communication network and allocated to the node device; a receiving unit for receiving communication information including second subgroup identification information allocated to a transmission source node device from one or more other node devices; a determination unit that determines a transmission destination node device from the one or more other node devices depending on a collation result between the first subgroup identification information and the second subgroup identification information included in the received communication information; and a transmission unit that transmits communication information including the first subgroup identification information to the determined transmission destination.

Description

  The present invention relates to a node device that constructs a wireless communication network by performing wireless communication between adjacent node devices.

  2. Description of the Related Art In recent years, with the development of technology for remotely operating a mobile device such as a mobile robot that performs work in a plant, maintenance technology for the mobile device has attracted attention. The following technique is an example of a technique related to maintenance of a mobile device.

  As a first technique, focusing on the fact that the controlled object is a mobile robot and being able to move freely within the plant, there is a technique that provides a data relay function in the communication means of the mobile robot so that the function of the fault relay device can be substituted. is there. In the first technique, communication between the controller and the mobile robot is maintained by relaying data between the mobile robot that cannot communicate and the normal relay device.

  As the second technique, there is the following technique. The autonomous control unit captures failure information from the wireless network through the wireless network connection unit. And candidate information is sent to a wireless network through an autonomous control part and a wireless network connection part. If the priority of the self-OA (office automation) device is higher than that of other candidate information, the location of the OA device where the failure has occurred is transmitted to the moving unit and moved. The autonomous control unit sends the cancellation information after this movement to the wireless network through the wireless network connection unit. In this way, one of the priority orders in the auxiliary dedicated OA device moves to the location of the failed OA device and the operation is continued.

Japanese Patent Publication No. 5-8893 JP-A-9-261253

  Ad hoc communication technology refers to communication technology in which devices directly communicate with each other without using an access point. In recent years, each communication device to which the ad hoc communication technology is applied recognizes a surrounding communication device, and wireless ad hoc network technology has attracted attention. When the wireless ad hoc network technology is applied, the next communication can be performed particularly in a place where it is difficult for humans to enter, such as a disaster-stricken area, underground, or a narrow place.

  FIG. 1 is a diagram for explaining an example of a wireless ad hoc network technology. In the example of FIG. 1A, a relay device (B to D) is connected, and a mobile device (leading device) A on which a camera and a sensor are mounted is used. The mobile device and the plurality of relay devices are equipped with communication devices to which wireless ad hoc communication technology is applied. In the wireless ad hoc communication technology, each of the mobile device and the plurality of relay devices autonomously receives radio waves with good communication quality according to the communication status of its surroundings and can communicate with each other. The control terminal 1 can remotely control the mobile device A via the gateway 2.

  Initially, the repeater (B to D) is connected to the leading device A, and the leading device A pulls the repeaters B to D. In this state, the leading device A connected to the repeaters (B to D) is moved by the remote operation by the control terminal 1 and proceeds in a direction away from the control terminal 1. Then, triggered by the decrease in the radio field strength between the leading device A and the control terminal 1, the leading device A disconnects the repeater D, and the leading device A connects the relay device D and the gateway 2 as shown in FIG. Communicate with the control terminal 1 via.

  Furthermore, the remote control by the control terminal 1 moves the leading device A connected to the repeaters (B to C) and proceeds in a direction away from the control terminal 1. Then, triggered by a decrease in radio field strength between the leading device A and the control terminal 1, the leading device A disconnects the repeater C, and the leading device A passes through the relay device C, the relay device D, and the gateway 2 to the control terminal. Communicate with 1.

  Further, by the remote operation by the control terminal 1, the leading device A connected to the repeater B moves and proceeds in a direction away from the control terminal 1. Then, triggered by the decrease in radio field strength between the leading device A and the control terminal 1, the leading device A disconnects the repeater B, and the leading device A passes through the relay device B, the relay device C, the relay device D, and the gateway 2. To communicate with the control terminal 1.

  Thus, since the HOP type network communication via the repeaters (B to D) can be performed between the leading device A and the control terminal 1, the leading device A moves far in proportion to the number of repeaters. It becomes possible to do.

  Assume that a wireless communication network automatic extension device intended for such use is used. When an abnormality occurs in any of the relay devices that construct the wireless communication network, the mobile device X0 connected to the repeaters X1 and X2 is again connected to replace the relay device as shown in FIG. Move to the site. The abnormality includes a case where a current state is not hindered in communication between the leading device A and the control terminal, such as a battery shortage, but a state in which an influence will appear in the near future is detected.

  However, since the communication device to which the wireless ad hoc network technology is applied establishes communication with the communication device that transmits the radio wave with the best communication quality, the following is assumed. That is, when the mobile device (maintenance mobile device) X0 introduced for maintenance approaches each node device such as the relay device (B to D) and the head device A, the radio wave intensity emitted from the maintenance mobile device is different. It is stronger than that from the node device. Therefore, a communication path is established between the maintenance mobile device and the node device. As a result, it is assumed that the routing of the existing wireless ad hoc network changes and communication between the leading device A and the control terminal 1 is disconnected.

  For example, when employing a maintenance mobile device that performs maintenance using an existing wireless ad hoc network that has already been laid by a wireless network automatic extension device, the following event may occur when communication is performed using the same network group ID. That is, as shown in FIG. 1C, when the maintenance mobile device X0 physically approaches the installed node device, the existing ad hoc network topology changes dynamically. As a result, end-to-end wireless ad hoc network communication is interrupted. As a result, the information of the camera or sensor mounted on the mobile device displayed on the control terminal 1 may be lost. Therefore, the maintenance mobile device needs to be maintained so that the topology of the wireless ad hoc network does not change. As described above, the maintenance mobile device for the wireless ad hoc network cannot maintain the ad hoc network while maintaining the ad hoc network topology laid by the wireless network automatic extension device.

  The present invention provides, as one aspect, a technique for maintaining the network topology of a built wireless communication network.

  A node device that constructs a wireless communication network by performing wireless communication between adjacent node devices according to an aspect of the present invention includes a storage unit, a reception unit, a determination unit, and a transmission unit. The storage unit stores first subgroup identification information that is identification information that identifies a subgroup that identifies a group formed in the wireless communication network and is identification information assigned to the own node device. The receiving unit receives communication information including second subgroup identification information assigned to the source node device from one or more other node devices. The determination unit determines a node device as a transmission destination from one or more other node devices according to a collation result between the first subgroup identification information and the second subgroup identification information included in the received communication information. To do. The transmission unit transmits communication information including the first subgroup identification information to the determined transmission destination.

  In the network topology control method for a wireless communication network constructed by performing wireless communication between adjacent node devices according to one aspect of the present invention, the following is executed. The node device has the first subgroup identification information assigned to the own node device and the subgroup identification information assigned to the transmission source node device included in the communication information received from one or more other node devices. If they match, a wireless communication network is constructed with another node device. The sub group identification information is identification information for identifying a sub group that identifies a group formed in the wireless communication network. When the movable node device assigned with the second subgroup identification information passes through the area of the wireless communication network constructed by the node device assigned with the first subgroup identification information, the following processing is performed. Done. That is, each of the node devices constructing the wireless communication network transmits and receives communication information including the first subgroup identification information, thereby maintaining the connection form of the wireless communication network.

  According to one aspect of the present invention, it is possible to maintain a network topology of a built wireless communication network.

It is a figure for demonstrating an example of a wireless ad hoc network technique. An example of the node apparatus in this embodiment is shown. An example of the configuration of the entire system in the present embodiment is shown. An example of the format of the Hello message frame in this embodiment is shown. An example of the link table in this embodiment is shown. An example of the routing table in this embodiment is shown. The structural example of the control terminal in this embodiment is shown. The structural example of the mobile apparatus and relay apparatus in this embodiment is shown. The link table and the update process flow of a routing table at the time of the Hello message reception performed by each node in this embodiment are shown. 6 shows a routing destination determination processing flow at the time of data transmission executed in each node in the present embodiment. The flow of deletion of the link table executed by each node and the record deletion processing flow of the corresponding routing table in this embodiment is shown. It is FIG. (1) for demonstrating the example which replaces a relay apparatus during communication via an ad hoc network in this embodiment (Example 1). FIG. 10 is a diagram (No. 2) for explaining an example of replacing a relay device during communication via an ad hoc network in the present embodiment (Example 1); FIG. 11 is a diagram (No. 3) for describing an example of replacing a relay device during communication via an ad hoc network in the present embodiment (Example 1); (4) for demonstrating the example which replaces a relay apparatus during communication via an ad hoc network in this embodiment (Example 1). FIG. 10 is a diagram (No. 5) for describing an example of replacing a relay device during communication via an ad hoc network in the present embodiment (Example 1); FIG. 16 is a diagram (No. 6) for describing an example of replacing a relay device during communication via an ad hoc network in the present embodiment (Example 1); FIG. 14 is a diagram (No. 7) for describing an example of replacing a relay device during communication via an ad hoc network in the present embodiment (Example 1); It is FIG. (The 1) for demonstrating the example which adds a relay apparatus and extends an ad hoc network in this embodiment (Example 2). It is FIG. (2) for demonstrating the example which adds a relay apparatus and extends an ad hoc network in this embodiment (Example 2). It is FIG. (3) for demonstrating the example which adds a relay apparatus and extends an ad hoc network in this embodiment (Example 2). It is a hardware structural example of the node apparatus in this embodiment.

  The system in the present embodiment includes a mobile device, a plurality of relay devices, a control terminal, and a gateway. Each of the mobile device and the plurality of relay devices is equipped with wireless ad hoc communication technology. The control terminal can remotely control the mobile device and the relay device. In the present embodiment, as an example, the present invention is applied to a case where a specific relay device in a wireless ad hoc network that has already been laid is maintained (that is, replaced with a new relay device) or a new relay device is added.

  The mobile device and the relay device communicate with each other by recognizing that they are communication devices in the same wireless ad hoc network using one network group ID. Here, the mobile device and the relay device are collectively referred to as “node device” or “node”.

  In the present embodiment, a sub group ID for managing a network group in the wireless ad hoc network specified by the network group ID is further introduced. This makes it possible to distinguish between an ad hoc network including an existing relay device and an ad hoc network including a maintenance mobile device or a maintenance relay device.

  Ad hoc communication devices equipped with wireless ad hoc communication technology can obtain communication quality and route information of adjacent relay devices by periodically transmitting and receiving Hello messages to each other. Thereby, the ad hoc communication apparatus can determine an optimal communication path.

  Further, in the present embodiment, by adding a sub group ID in the Hello message, the ad hoc communication devices can notify which sub group they belong to in a common network group.

  Arbitrary subgroup IDs can be set from the control terminal for ad hoc communication devices (existing relay device group (including mobile devices), maintenance relay device group (including maintenance mobile devices)). The ad hoc communication device can set / change affiliation to a subgroup based on a remote operation from a control terminal or a setting instruction from an operation unit provided in the device. Moreover, the ad hoc communication apparatus can transmit to the same subgroup as itself using the routing table produced | generated based on the link table containing the subgroup ID obtained from the received Hello message.

  Subgroups are also given priority. At this time, it is assumed that an ad hoc communication device of a subgroup with a low priority approaches within the radio wave effective range of a wireless ad hoc network using the subgroup with a high priority. In this case, the ad hoc communication device does not change the route of the group with the higher priority.

  As a result, a mobile device for maintenance equipped with wireless ad hoc communication technology reaches the target location without disrupting the topology of the ad hoc network even if it passes through the existing relay device configured with the ad hoc network. It becomes possible.

  FIG. 2 shows an example of a node device in the present embodiment. The node device 1 constructs a wireless communication network by performing wireless communication between adjacent node devices. The node device 10 includes a storage unit 11, a reception unit 12, a determination unit 13, and a transmission unit 14.

  The storage unit 11 stores first subgroup identification information that is identification information that identifies a subgroup that identifies a group formed in the wireless communication network and is identification information assigned to the own node device 10. An example of the storage unit 11 is the configuration definition DB 35.

  The receiving unit 12 receives communication information including second subgroup identification information assigned to the source node device from one or more other node devices 10a. An example of the receiving unit 12 is a wireless interface unit 30.

  The determination unit 13 determines a node device that is a transmission destination from one or more other node devices 10a in accordance with a collation result between the first subgroup identification information and the second subgroup identification information included in the received communication information. To decide. An example of the determination unit 13 is a data transmission processing unit 28.

  The transmission unit 14 transmits communication information including the first subgroup identification information to the determined transmission destination. An example of the transmission unit 14 is a wireless interface unit 30.

  The determination unit 13 can determine, from the route information, a transmission destination candidate having second subgroup identification information that matches the first subgroup identification information as a transmission destination. The path information relates to a transmission path in which transmission destination candidate information in which a transmission destination candidate indicated by a node device that is a transmission source of received communication information is associated with second transmission destination candidate second subgroup identification information is stored. Is. An example of the route information is the routing table 33.

  When the path information does not include subgroup identification information that matches the first subgroup identification information, the determination unit 13 determines a transmission destination from the transmission destination candidates according to the communication environment of the transmission destination candidate. Can do.

  Here, the route information stores transmission destination candidate information in the order of priority given to the subgroup identification information.

  By configuring in this way, the network topology of the constructed wireless communication network can be maintained.

  Further, in the method for controlling the network topology of the wireless communication network constructed by performing wireless communication between adjacent node devices, the following is executed. The node device 10 includes the first subgroup identification information assigned to the own node device and the subgroup identification information assigned to the transmission source node device included in the communication information received from one or more other node devices 10a. The following processing is performed when and match. That is, the node device 10 constructs a wireless communication network with other node devices. Here, the subgroup identification information is identification information for identifying a subgroup that identifies a group formed in the wireless communication network. When the movable node device assigned with the second subgroup identification information passes through the area of the wireless communication network constructed by the node device assigned with the first subgroup identification information, the following processing is performed. Done. That is, each of the node devices constructing the wireless communication network transmits and receives communication information including the first subgroup identification information, thereby maintaining the connection form of the wireless communication network.

  Thereby, for example, maintenance can be performed without affecting the routing of the constructed wireless communication network.

  FIG. 3 shows a configuration example of the entire system in this embodiment. The system 20 includes a control terminal 21, a gateway (GW) 22, a plurality of relay devices 23, and a mobile device 24. The control terminal 21 controls the plurality of relay devices 23 and the moving device 24 by remote operation. The control terminal 21 can set arbitrary subgroup IDs for the plurality of relay devices 23 and the mobile devices 24 by remote operation. The sub group ID is a group ID accompanying the network group ID. The subgroup ID will be described later.

  The GW 22 enables communication by mutually converting data based on the protocol used in the ad hoc network and data based on the protocol used by the control terminal. The system 20 is applied when maintaining (replacing) a specific relay device in a wireless ad hoc network that has already been laid or adding a new relay device.

  The plurality of repeaters 23 and the mobile devices 24 are equipped with wireless ad hoc network communication technology, and are connected to each other by wireless ad hoc communication to form a wireless ad hoc network. The repeater 23 and the mobile device 24 have the same configuration related to the wireless ad hoc network communication technology, and the relay device 23 in which a camera and a sensor are mounted corresponds to the mobile device 24. Therefore, in FIG. 3, the relay device 23 and the moving device 24 are shared.

  The control terminal 21 is connected to a gateway (GW) 22 by wire. The control terminal 21 is connected to the wireless ad hoc network by connecting to any one of the relay devices 23 via the GW 22.

  The existing mobile device 24 and the relay device 23 communicate using a single network group ID to construct a common wireless ad hoc network.

  The relay device 23 and the mobile device 24 include a data generation relay processing unit 25, a data transmission processing unit 28, an ad hoc protocol processing unit 29, a wireless interface unit 30, a data reception processing unit 31, and a storage unit 36.

  The wireless interface unit 30 is a wireless communication interface that performs wireless communication with other nodes and the GW 22. For example, the wireless interface unit 30 receives a Hello message or normal communication data from another adjacent node, and outputs it to the ad hoc protocol processing unit 29. In addition, the wireless interface unit 30 broadcasts the Hello message received from the ad hoc protocol processing unit 29 to an adjacent node, or transmits the communication data received from the ad hoc protocol processing unit 29 to the destination node.

  The ad hoc protocol processing unit 29 adds an ad hoc header to each data transmitted from the data transmission processing unit 28 and transmits the data to the destination, and outputs the data received by the wireless interface unit 30 to the data reception processing unit 31. For example, when a hello message is input from the data transmission processing unit 28, the ad hoc protocol processing unit 29 adds an ad hoc header to the hello message and broadcasts to an adjacent node.

  In addition, when data is input from the data transmission processing unit 28, the ad hoc protocol processing unit 29 refers to the configuration definition DB 35, and uses a channel number and a group ID, a subgroup of a communication target used by the type of the data. Get an ID. Subsequently, the ad hoc protocol processing unit 29 adds an ad hoc header to which the channel number, group ID, subgroup ID, etc. acquired from the configuration definition DB 35 are added to the input data, and the routing information stored in the routing table 33. To transmit to the destination node. The routing table 33 is a table that stores the number of hops, route quality weight, return link weight, and the like as route information to the destination node. The routing table 33 stores a predetermined number of routes as the optimum route among the plurality of routes to the destination node, for example, in ascending order of communication quality weight, that is, in order of good communication quality.

  The ad hoc protocol processing unit 29 determines whether the data received by the wireless interface unit 30 is the above-described Hello message or communication data processed by an application program or the like. Then, if the received data is a Hello message, the ad hoc protocol processing unit 29 transfers the Hello message to the data reception processing unit 31.

  In addition, when the received data is communication data, the ad hoc protocol processing unit 29 acquires channel information included in the communication data, and determines whether the acquired channel information is channel information to be communicated. . Specifically, the ad hoc protocol processing unit 29 acquires the type of communication data and the channel number from the ad hoc header of the received communication data. Then, the ad hoc protocol processing unit 29 stores the combination of the acquired communication data type and channel number in the configuration definition DB 35, that is, the received communication data is data transmitted with the communication target channel number. It is determined whether.

  Thereafter, the ad hoc protocol processing unit 29 outputs the communication data to the data reception processing unit 31 when it is determined that the channel information is the communication target, that is, the data is transmitted with the normal channel number. The ad hoc protocol processing unit 29 discards the received communication data when it is determined that the data is not the channel number to be communicated, that is, the data is not transmitted with a normal channel number.

  The data reception processing unit 31 performs various reception processes on the data output from the ad hoc protocol processing unit 29. For example, if the data output from the ad hoc protocol processing unit 29 is communication data, the data reception processing unit 31 receives the communication data from the data generation relay processing unit 25 that executes an application or the like that is to be processed. Output the communication data.

  Further, when the data output from the ad hoc protocol processing unit 29 is a Hello message, the data reception processing unit 31 generates or updates the link table 34 and the routing table 33. The link table 34 stores each piece of information received by a Hello message. For example, the link table 34 stores a local transmission source address (LS), link quality information, the number of Hello receptions, a Hello request interval, and the like. Specifically, the data reception processing unit 31 refers to “local transmission source address (LS)” of the link table 34 to determine whether or not the received Hello message is transmitted from a new transmission source node. Judgment. Then, the data reception processing unit 31 generates a new link table 34 when it is transmitted from a new transmission source node.

  In addition, the data reception processing unit 31 updates the link table 34 when it is not transmitted from a new transmission source node but transmitted from an existing node.

  Further, when the above-described update or new generation of the link table 34 is performed, the data reception processing unit 31 generates routing information from the information stored in the link table 13 and stores it in the routing table 33.

  The data reception processing unit 31 includes a priority group selection unit 32. The sub-group ad hoc network specified by the sub-group ID has priority. For example, it is assumed that the subgroup indicated by subgroup ID = 1 has higher priority than the subgroup indicated by subgroup ID = 2. When generating the routing table, the priority group selection unit 32 registers the route information in the routing table in order of priority of the subgroup ID.

  The data generation relay processing unit 25 executes the program and transmits the generated data and the like to another node or another network. For example, the data generation relay processing unit 25 outputs data generated by an application process or the like executed using an upper protocol layer such as an application layer or a presentation layer to the data transmission processing unit 28. In addition, when the data generation relay processing unit 25 receives communication data from the data reception processing unit 31, the data generation relay processing unit 25 executes an application or the like that processes the communication data, and transmits new data generated based on the execution result to the destination. The result is held in a storage unit (not shown).

  The data generation relay processing unit 25 includes a route report unit 26 and a belonging group change unit 27. The route report unit 26 transmits route information of the own node to the control terminal 21.

  The affiliation group changing unit 27 sets / changes affiliation to a subgroup based on a subgroup ID setting or change instruction transmitted from the control device 21 based on a remote operation from the control device 21.

  When reaching the Hello message timing, the data transmission processing unit 28 generates a Hello message and outputs it to the ad hoc protocol processing unit 29. For example, the data transmission processing unit 28 stores the node information stored in the device itself in the Hello header in an ad hoc header, a compressed header, a Hello message header, a plurality of Hello headers, and a signature included in the Hello message. Specifically, the data transmission processing unit 28 stores optimum route information for each global destination node (GD) stored in the routing table 33 in each of the plurality of Hello headers. Then, the data transmission processing unit 28 generates a Hello message including a Hello header added with node information for each global destination node (GD) and outputs the Hello message to the ad hoc protocol processing unit 29.

  In addition, when receiving communication data from the data generation relay processing unit 25, the data transmission processing unit 28 outputs an ad hoc frame data transmission request for requesting addition of an ad hoc header to the ad hoc protocol processing unit 29 together with the communication data. To do.

  The storage unit 36 is a storage device such as an SSD (Solid State Drive), a hard disk drive, or a semiconductor memory device. The storage unit 36 stores a routing table 33, a link table 34, a configuration definition database (DB) 35, a program for executing processing to be described later, and the like.

  The link table 34 is a table that holds information extracted from the received Hello message by the data reception processing unit 31. The routing table 33 is a table that holds routing information for adjacent nodes managed in units of final destination nodes. The configuration definition DB 35 is a database that holds configuration information such as the communication status, group ID, and subgroup ID of the relay device 23 or the mobile device 24. For example, the configuration definition DB 35 stores a channel number used in the communication data in association with the type of communication data, and stores a wireless transmission signal output level value at a local point.

  As a result, by introducing a subgroup ID in a common wireless ad hoc network, it is possible to further form subgroups and enable communication within the common subgroup among the subgroups. it can. As a result, a maintenance mobile device equipped with wireless ad hoc communication technology can reach the target location without disrupting the topology of those ad hoc networks even if it passes through the existing relay device configured with an ad hoc network. It becomes possible to do.

  FIG. 4 shows an example of the format of the Hello message frame in the present embodiment. The Hello message frame refers to a frame that the node according to the present embodiment transmits to another node device to confirm each other's existence / state. The Hello message frame is transmitted and received in a wireless ad hoc network formed between nodes, that is, between the relay devices 23 and between the relay device 23 and the mobile device 24.

  The Hello message frame includes data items of “frame header” 41, “Hello message header” 42, “Hello header” 43, “MAC header” 44, “ad hoc header” 45, and “payload” 46.

  The “frame header” 41 includes a “local destination address” 41-1, a “local source address” 41-2, frame buffer management information, and parameters at the time of transmission / reception. The “local destination address” 41-1 indicates a destination node ID representing an adjacent node device to which a frame is to be passed next when a certain node device is viewed as a subject. The “local source address” 41-2 refers to a node ID representing a node device that directly sends a frame to a local destination address (that is, a local node device for the local destination address). The “Hello message header” 42 includes information regarding the Hello transmission source node.

  The “Hello header” 43 includes a “global destination address” 43-1 and route quality information to the GW viewed from the Hello transmission source node. The global destination address refers to a node ID that is the final destination for a series of propagation of data frames across a network.

  The “MAC header” 44 indicates a storage area for header information of a MAC (Media Access Control) frame. “Payload” 46 indicates a data portion.

  The “ad hoc header” 45 indicates a storage area for header information based on the ad hoc communication protocol. The “ad hoc header” 45 includes a “group ID” 45-1 and a “subgroup ID” 45-2. “Group ID” 45-1 indicates a network group ID for grouping ad hoc networks. The “subgroup ID” 45-2 indicates an ID for specifying a subgroup formed in the network specified by the network group ID. A priority is given to the ad hoc network in the subgroup specified according to the subgroup ID. For example, in the present embodiment, the priority is higher as the value of the subgroup ID is smaller.

  FIG. 5 shows an example of a link table in the present embodiment. Each node has a link table 34 for nodes adjacent to the node. A node adjacent to itself indicates a node that performs ad hoc communication with itself. When each node receives a Hello message frame from a node adjacent to itself, each node generates a link table 34 for the node that has transmitted the Hello message frame.

  The link table 34 includes data items of “local source address” 51, “aging timer” 52, “HELLO and received radio wave related parameters” 53, and “subgroup ID” 54.

  The “local source address” 51 stores the source address of the Hello message frame, that is, the local source address included in the ad hoc header of the Hello message frame received from the adjacent node.

  The “aging timer” 52 is information for adjusting the timing of deleting the link table 34, and a default value is set when the link table 34 is created.

  The “HELLO and received radio wave related parameters” 53 stores information included in various headers of Hello message frames received from adjacent nodes, received radio wave strength (or communication quality), and other received radio wave related parameters. Each node transmits a Hello message frame including information related to the communication quality of radio waves received from other nodes. The node refers to the Hello message frame received from the other node device, calculates the communication quality of the adjacent node, and the “HELLO and received radio wave related parameter” 53 includes information related to the calculated reception strength (or communication quality). Hold.

  The “subgroup ID” 54 stores the subgroup ID included in the ad hoc header of the Hello message frame received from the adjacent node.

  FIG. 6 shows an example of the routing table in the present embodiment. The routing table 33 is a table that holds routing information for adjacent nodes managed in units of global destination addresses (GD), and is generated for each global destination address. Each node generates the routing table 33 using the link table 34 generated from the Hello message frame received from the adjacent node.

The routing table 33 includes “global destination address” 61 and “local destination related information” 62 (62-1, 62-2, 62-3).
The “local destination related information” 62 is a predetermined unit in the order of priority of the subgroup ID and in the order of good reception strength (or communication quality) among a plurality of routes to the local destination node in units of “global destination address” 61. A number of routes (three in the example of this embodiment) are stored as optimum routes. “Local destination related information” 62 is information obtained from each link table 34 and includes “local destination address”, “route quality information”, and “subgroup ID”.

  For example, the “local destination related information” 62-1 includes “local destination address 1” 62-11, “route quality information 1” 62-12, and “subgroup ID 1” 62-13. The “local destination related information” 62-2 includes “local destination address 2” 62-21, “route quality information 2” 62-22, and “subgroup ID 2” 62-23. The “local destination related information” 62-3 includes “local destination address 3” 62-31, “route quality information 3” 62-32, and “subgroup ID 3” 62-33.

  In the “local destination address”, the “local source address” of the link table 34 is set. In the “route quality information”, “HELLO and received radio wave related parameters” 53 of the link table 34 is set. In the “subgroup ID”, the “subgroup ID” 54 of the link table 34 is set.

  FIG. 7 shows a configuration example of the control terminal in the present embodiment. The control terminal 21 includes an information display function unit 41, a device information processing unit 42, a device operation control unit 43, a device operation function unit 44, and a wireless communication processing unit 45.

  The wireless communication processing unit 45 is a communication interface that processes transmission of a command for operation to the mobile device 24 or reception of collected data from the mobile device 24 via the antenna 47 by wireless communication. The wireless communication processing unit 45 has an ad hoc function 46. The ad hoc function 46 performs protocol conversion and performs setting management for wireless ad hoc communication in order to perform wireless ad hoc communication.

  The device information processing unit 42 is a device that converts the collected data from the mobile device 24 obtained by the wireless communication processing unit 45 into video data or the like, and stores it, for example, a microprocessor unit (MPU) or the like. This is realized by the processor. The information display function unit 41 is a display that displays an image from a camera mounted on the moving device 24 or position information of the moving device 24.

  The device operation function unit 44 enables remote operation of an ON / OFF switch such as an information collecting device mounted on the moving device 24 and the moving device 24. In addition, information such as a subgroup ID can be input using the device operation function unit 44. The device operation control unit 43 generates a command for the mobile device from input information from the device operation function unit 44.

  FIG. 8 shows a configuration example of the mobile device and the relay device in the present embodiment. The mobile device 24 includes a mobile function unit 51, an operation control unit 52, an information processing unit 54, an information collection device 55, and a communication processing unit 56.

  The moving function unit 51 is a wheel driving mechanism such as a motor, or a servo mechanism that automatically operates to follow a target value using the position, orientation, orientation, and the like of the moving device 24 as control amounts.

  The operation control unit 52 converts the operation control information from the control terminal 21 into data for the mobile function unit 51 and the information collecting device 55 and transfers the data. The operation control unit 52 further has a separation control function 53. The separation control function performs separation control of the relay device 23 that is being pulled by the moving device 24.

  The information collecting device 55 is various sensor devices such as a camera, a GPS (Global Positioning System) logger, and a sonar.

  The information processing unit 54 converts the information collection device 55 and its own wireless strength control information into data and transmits it. The communication processing unit 56 is a communication interface that processes reception of commands for operations on the mobile device 24 or transmission of collected data via the antenna 58 by wireless communication. The communication processing unit 56 has an ad hoc function. The ad hoc function 57 performs protocol conversion and performs setting management for wireless ad hoc communication in order to perform wireless ad hoc communication.

  The relay device 23 includes a mobile function unit 61, an operation control unit 62, an information processing unit 64, and a communication processing unit 66. The relay device 23 is obtained by removing the information collection device 55 from the mobile device 24, and the operation control unit 52 does not have a separation control function. Further, the operation control unit 62 of the relay device 23 does not have the separation control function 53.

  The moving function unit 61 is a wheel driving mechanism such as a motor, or a servo mechanism that automatically operates to follow a target value using the position, orientation, orientation, and the like of the moving device 24 as control amounts.

  The operation control unit 62 converts the operation control information from the control terminal 21 into data for the mobile function unit 51 and the information collection device 55 and transfers the data.

  The information processing unit 64 transfers the wireless strength control information of the mobile device 24 or other relay device 23. The communication processing unit 66 is a communication interface that processes reception of commands for operating the mobile device 24 or transfer of collected data via the antenna 68 by wireless communication. The communication processing unit 66 has an ad hoc function. The ad hoc function 67 performs protocol conversion and performs setting management for wireless ad hoc communication in order to perform wireless ad hoc communication.

  FIG. 9 shows an update process flow of the link table and the routing table at the time of receiving the Hello message executed in each node in this embodiment. The flow in FIG. 9 is executed by each node for each ad hoc network managed by the network group ID.

  The node receives a Hello message from an adjacent node (S1). The node extracts a local source address from the ad-hoc header of the received Hello message, and searches the link table 34 for a link table 34 corresponding to the extracted local source address (S2).

  In S2, when there is a link table 34 corresponding to the extracted local source address (“Yes” in S2), the node updates information in the link table 34 (S3). Here, the “HELLO and received radio wave related parameters” 53 in the link table 34 are updated based on various header information of the received Hello message. Further, for example, “+1” is added to the value of the “aging timer” 52.

  In S2, if there is no link table 34 corresponding to the extracted local source address (“No” in S2), the node newly creates a link table for the extracted local source address (S4). In this case, the node extracts the subgroup ID from the ad-hoc header of the received Hello message, sets the local source address and subgroup ID in the newly created link table 34, and further sets the HELLO and received radio wave related parameters. To do. Further, the node sets a default value in the aging timer of the link table 34.

  The node updates the routing table 33 using the contents of the link table 34 updated in S3 or the contents of the link table 34 newly created in S4 (S5). The routing table 33 stores “local destination related information” in the order of priority of the subgroup ID and in the order of good reception strength (or communication quality) in units of “global destination addresses”.

  FIG. 10 shows a routing destination determination process flow at the time of data transmission executed in each node in the present embodiment. The flow in FIG. 10 is executed by each node in units of ad hoc networks managed by the network group ID. When transmitting a Hello message to an adjacent node, each node determines a transmission destination based on the flow of FIG. 10, and transmits a Hello message to the transmission destination.

  First, the node refers to one of a plurality of routing tables 33, and determines whether or not a global destination address as a transmission destination is registered in the referenced routing table 33 (S11). When the global destination address is not registered in the routing table 33 (“No” in S11), the node refers to the next routing table 33 and performs the determination in S11. In S11, when the global destination address is registered in the referenced routing table 33 (“Yes” in S11), the process of S12 is performed. The node performs the process of S11 for each routing table 33. If no global destination address is registered as a transmission destination in any routing table 33, communication is disabled.

  When the global destination address is registered in the routing table 33, the node searches the subgroup ID in the registration order (priority order) in the routing table 33, and the searched subgroup ID matches the own subgroup ID. It is determined whether or not to perform (S12). If the retrieved subgroup ID does not match the own subgroup ID (“No” in S12), the node retrieves the next subgroup ID from the routing table 33, and performs the determination in S12. The process of S12 is repeated for the number of subgroup IDs registered in the routing table 33.

  When the retrieved subgroup ID matches the own subgroup ID (“Yes” in S12), the node selects the “local destination address” corresponding to the subgroup ID from the routing table 33 as the transmission destination. (S14). Thereby, a local destination address as a data transmission destination is determined.

  As a result of repeating the process of S12 by the number of subgroup IDs registered in the routing table 33, if there is no matching subgroup, the node performs the following process. That is, the node selects “local destination address 1” registered first in the routing table 33 as a transmission destination (S13). Thereby, a local destination address as a destination to which data is transmitted is determined.

  FIG. 11 shows a link table deletion process flow and a corresponding link table record deletion process executed by each node in this embodiment. The flow in FIG. 11 is executed by each node in units of ad hoc networks managed by network group IDs. Further, the flow of FIG. 11 is executed by the node checking the aging timer at a certain period.

  The node refers to one of the plurality of link tables 34, and determines whether or not the value of the aging timer of the referenced link table 34 is greater than 0 (S21). When the value of the aging timer is larger than 0 (“Yes” in S21), the node subtracts the value of the aging timer by a predetermined value (for example, “1”) (S24).

  When the value of the aging timer of the referenced link table 34 is 0 or less (“No” in S21), the node deletes the referenced link table 34 (S22). Then, the node acquires the routing table 33 in which the local source address (local destination address) of the deleted link table 34 is registered. The node deletes “local destination related information” (“local destination address”, “route quality information”, “subgroup ID”) including the local destination address from the acquired routing table 33 (S23).

  After the processing of S23 or S24, the node performs S21-S24 for the next link table 34. The processes of S21 to S24 are repeated for the number of link tables.

  The above-described embodiment will be described more specifically with reference to FIGS.

Example 1
FIGS. 12 to 18 are diagrams for explaining an example of replacing the relay device during communication via the ad hoc network in the present embodiment (Example 1). 12-18, the solid line arrow shows a wired network. A dashed arrow indicates a wireless ad hoc network with subgroup ID = 1. A dotted arrow indicates a wireless ad hoc network with subgroup ID = 2. Further, it is assumed that the subgroup ID = 1 has a higher priority than the subgroup ID = 2. Each node can generate a link table 34 and a routing table based on a Hello message received from an adjacent node, and thus has a routing table for a transmission destination (for example, the control terminal 21).

  [Procedure 1.1] FIG. 12 shows a state in which a wireless ad hoc network with subgroup ID = 1, in which mobile device A is at the head and relay devices B to D are arranged behind it, is constructed. The relay apparatus B notifies the control terminal 21 that the battery needs to be replaced because the remaining battery level is equal to or less than the threshold value.

  [Procedure 1.2] The maintenance worker prepares a maintenance mobile device (maintenance mobile device) X0 and relay devices X1 and X2 connected to the mobile device X0. Subgroup ID = 2 is set in X0. Subgroup ID = 1 is set in relay apparatuses X1 and X2.

  As illustrated on the upper side of FIG. 13, the mobile device X0 and the relay device D transmit the Hello message including the subgroup ID, and update the link table 34 and the routing table 33.

  The lower table of FIG. 13 shows information of the routing table 33 for the control terminal 21 of each relay device 23 and the moving device 24 when the maintenance moving device X0 starts moving.

  For example, the relay device D is connected to the GW 22 through a wireless ad hoc network with subgroup ID = 1, and is connected to the maintenance mobile device X0 through a wireless ad hoc network with subgroup ID = 2. In this case, communication to the ad hoc network having the subgroup ID that matches the subgroup ID of the relay device D is prioritized ("Yes" in S12, S14 in FIG. 10), so communication between the GW 22 and the relay device D. Becomes effective.

  The relay device C is connected to the relay device D by wireless ad hoc communication with subgroup ID = 1. The relay device B is connected to the relay device C by wireless ad hoc communication with subgroup ID = 1. The mobile device A is connected to the relay device B by wireless ad hoc communication with subgroup ID = 1.

  [Procedure 1.3] The maintenance mobile device X0 moves toward the relay device B. As a moving method of the maintenance mobile device X0, for example, a remote operation from the control terminal 21 or a method of tracing a travel log of an existing relay device can be considered. At that time, the mobile device X0 is controlled by the control terminal 21 via the relay device D. When the maintenance mobile device X0 comes close to the radio wave effective range of the relay device C, Hello messages are transmitted to each other in the same manner as in [Procedure 1.2], and the mutual information is exchanged.

  FIG. 14 shows each relay device and mobile device at the time when the maintenance mobile device X0 reaches the vicinity of the relay device C, the position of the maintenance mobile device, and the information in the routing table 33 for those control terminals.

  For example, the relay device D is connected to the GW 22 by wireless ad hoc communication with subgroup ID = 1. Compared to FIG. 13, the reason why the record of “local destination address (LD) = X0” is deleted from the control terminal routing table 33 of the relay apparatus D in FIG. 14 is as follows. Since the maintenance mobile device X0 is separated from the relay device D and the relay device D cannot receive the Hello message from the maintenance mobile device X0, the aging timer is decreased as described in FIG. The link table 34 for the mobile device X0 is deleted. As a result, the routing table 33 is also updated based on the deleted link table 34, and the record relating to “local destination address (LD) = X0” is deleted from the routing table 33. In the following description, the process of deleting the local destination address (LD) from the routing table 33 is omitted.

  The relay device C is connected to the relay device D through a wireless ad hoc network with subgroup ID = 1, and is connected to the maintenance mobile device X0 through a wireless ad hoc network with subgroup ID = 2. In this case, communication to an ad hoc network having a subgroup ID that matches the subgroup ID of relay device C is prioritized ("Yes" in S12, S14 in FIG. 10), so communication between relay devices CD. Becomes effective.

  The relay device B is connected to the relay device C through a wireless ad hoc network with subgroup ID = 1, and is connected to the maintenance mobile device X0 through a wireless ad hoc network with subgroup ID = 2. In this case, communication to the ad hoc network having a subgroup ID that matches the subgroup ID of relay device B is prioritized ("Yes" in S12, S14 in FIG. 10), so communication between relay devices B-C. Becomes effective.

  The mobile device A is connected to the relay device B by wireless ad hoc communication with subgroup ID = 1.

  [Procedure 1.4] When the maintenance mobile device X0 reaches the periphery of the target relay device B, the state becomes the upper side of FIG. The table on the lower side of FIG. 15 shows the information in the routing table 33 for the control terminal of each relay device 23 and the mobile device 24 when the maintenance mobile device X0 reaches the vicinity of the relay device B.

  For example, the relay device D is connected to the GW by wireless ad hoc communication with subgroup ID = 1. The relay device C is connected to the relay device D by wireless ad hoc communication with subgroup ID = 1.

  The relay device B is connected to the relay device C by wireless ad hoc communication with subgroup ID = 1, and is connected to the maintenance mobile device X0 by wireless ad hoc communication with subgroup ID = 2. In this case, communication to the ad hoc network having a subgroup ID that matches the subgroup ID of relay device B is prioritized ("Yes" in S12, S14 in FIG. 10), so communication between relay devices B-C. Becomes effective.

  The mobile device A is connected to the maintenance mobile device X0 by wireless ad hoc communication with subgroup ID = 2, and is connected to the relay device B by wireless ad hoc communication with subgroup ID = 1. In this case, communication to the ad hoc network having a subgroup ID that matches the subgroup ID of mobile device A is prioritized ("Yes" in S12, S14 in FIG. 10), so communication between relay devices A and B is performed. Becomes effective.

  [Procedure 1.5] The maintenance mobile device X0 performs ad hoc communication with a neighboring relay device, and transmits a wireless deactivation request for the relay device B to the control terminal 21. Then, the neighboring relay device transfers the wireless deactivation request to the control terminal 21 using the control terminal routing table.

  The control terminal 21 that has received the request transmits a radio deactivation instruction to the relay apparatus B. The wireless deactivation instruction is transmitted to the relay apparatus B via the GW 22 and each relay apparatus. Here, since the routing table for the relay device B is generated in each relay device, each relay device uses the routing table for the relay device B to address the wireless deactivation instruction to the relay device B. Can be transferred.

  The relay device B performs wireless deactivation after receiving the deactivation instruction. Then, the relay device B is disconnected from the wireless ad hoc network with subgroup ID = 1 (the upper diagram in FIG. 16).

  The table on the lower side of FIG. 16 shows information of the routing table 33 for the control terminal 21 of each relay device 23 and the mobile device 24 at the time when the radio of the relay device B is deactivated.

  For example, the relay device D is connected to the GW by wireless ad hoc communication with subgroup ID = 1. The relay device C is connected to the relay device D by wireless ad hoc communication with subgroup ID = 1.

  In the relay apparatus B, the aging timer decreases due to the wireless inactivation, and as a result, the link table 34 is deleted according to the flow of FIG. 11, and the routing table 33 is also updated based on the deleted link table 34. .

  Since the mobile device A can no longer receive the Hello message from the relay device B, the aging timer is decreased and the mobile device A erases the link table for the relay device B as described in FIG. As a result, the mobile device A updates the routing table 33 based on the deleted link table 34 and deletes the record of “local destination address (LD) = B” from the routing table 33. Then, in the routing table 33 of the mobile device A, the record group (“local destination related information”) for “local destination address (LD) = X0” is the highest. Since there is no subgroup ID that matches the subgroup ID of the mobile device A in the routing table 33, the mobile device A selects the “local destination address (LD)” registered first in the routing table 33 (FIG. 10). In S12, “No” in S12, S13). As a result, “local destination address (LD) = X0” is selected, and communication between the mobile device A and the maintenance mobile device X0 becomes valid.

  [Procedure 1.6] The control terminal 21 issues a wireless activation instruction for the relay device X2 connected to the maintenance mobile device X0. Here, since the relay device X2 is set as the subgroup ID = 1, as shown in the upper side of FIG. 17, the Hello message is transmitted to the adjacent node as the subgroup ID = 1. After receiving the Hello message from the relay device X2, the mobile devices A, X0 and the relay device C generate a link table 34 for information on the relay device X2, and update the routing table 33 based on the generated link table. . As a result, the ad hoc network with subgroup ID = 1 can be replaced with a configuration of GW → relay device D → relay device C → relay device X2 → mobile device A.

  The table on the lower side of FIG. 17 shows information of the routing table 33 for the control terminal 21 of each relay device 23 and the mobile device 24 at the time of wireless activation of the relay device X2.

  For example, the relay device D is connected to the GW by wireless ad hoc communication with subgroup ID = 1. The relay device C is connected to the relay device D by wireless ad hoc communication with subgroup ID = 1.

  The relay device X2 is connected to the relay device C through wireless ad hoc communication with subgroup ID = 1, and is connected to the maintenance mobile device X0 through wireless ad hoc communication with subgroup ID = 2. In this case, communication to an ad hoc network having a subgroup ID that matches the subgroup ID of relay device X2 is given priority ("Yes" in S12, S14 in FIG. 10), so communication between relay devices C-X2 Becomes effective.

  The mobile device A is connected to the maintenance mobile device X0 by wireless ad hoc communication with subgroup ID = 2, and is connected to the relay device X2 by wireless ad hoc communication with subgroup ID = 1. In this case, communication to the ad hoc network having a subgroup ID that matches the subgroup ID of mobile device A is prioritized ("Yes" in S12, S14 in FIG. 10), so communication between relay devices A-X2 Becomes effective.

  [Procedure 1.7] When replacement with the target relay device is completed, that is, when the ad hoc network with subgroup ID = 1 is configured as GW → relay device D → relay device C → relay device X2 → mobile device A The following processing is performed. That is, the control terminal 21 transmits an instruction to disconnect the relay device X2 to the maintenance mobile device X0. The maintenance mobile device X0 that has received the disconnection instruction disconnects the relay device X2 as shown in the upper side of FIG. Alternatively, when the maintenance mobile device X0 is notified that the relay device X2 has been replaced with the relay device X2, the maintenance mobile device X0 may automatically disconnect the relay device X2.

  As shown in the lower side of FIG. 18, immediately after disconnecting the relay device X2, the information in the routing table for the control terminal of the mobile device A and the relay device B is the same as in FIG. However, if the maintenance mobile device X0 leaves and cannot receive the Hello message from the maintenance mobile device X0, the record related to “local destination address (LD) = X0” is deleted from those routing tables.

(Example 2)
Next, an example in which a relay device is added to extend an ad hoc communication network will be described. FIG. 19 to FIG. 21 are diagrams for explaining an example in which an ad hoc communication network is extended by adding a relay device in the present embodiment (example 2). The relay device (including the maintenance relay device) and the mobile device (including the maintenance mobile device) in the second embodiment are the same as those described in the first embodiment.

  [Procedure 2.1] FIG. 19 shows a state in which an ad hoc network is constructed with the subgroup ID = 1 of the mobile device A and the relay devices B to C, starting with the mobile device A. The maintenance worker remotely operates the control terminal 21 to start the movement of the maintenance mobile device X0 with the moving destination as the mobile device A. The procedure during the movement of the maintenance mobile device A is the same as the procedure 1.2 to 1.3 in the first embodiment.

  The table on the lower side of FIG. 19 shows information in the routing table 33 for the control terminal of each relay device 23 and the mobile device 24 when the maintenance mobile device X0 reaches the vicinity of the mobile device A.

  For example, the relay apparatus C is connected to the GW by wireless ad hoc communication with subgroup ID = 1.

  The relay device B is connected to the relay device C by wireless ad hoc communication with subgroup ID = 1, and is connected to the maintenance mobile device X0 by wireless ad hoc communication with subgroup ID = 2. In this case, communication to the ad hoc network having a subgroup ID that matches the subgroup ID of relay device B is prioritized ("Yes" in S12, S14 in FIG. 10), so communication between relay devices B-C. Becomes effective.

  The mobile device A is connected to the relay device B by wireless ad hoc communication with subgroup ID = 1, and is connected to the maintenance mobile device X0 by wireless ad hoc communication with subgroup ID = 2. In this case, communication to the ad hoc network having a subgroup ID that matches the subgroup ID of mobile device A is prioritized ("Yes" in S12, S14 in FIG. 10), so communication between relay devices A and B is performed. Becomes effective.

  Here, it is assumed that the subgroup of maintenance mobile device X0 is subgroup ID = 2, and the subgroup of relay devices X1 and X2 is subgroup ID = 1. When the maintenance mobile device X0 reaches the periphery of the mobile device A, it performs ad hoc communication with a neighboring relay device, and transmits a wireless activation request for the relay device X2 to the control terminal 21. Then, the neighboring relay device transfers the wireless deactivation request to the control terminal 21 using the control terminal routing table.

  The control terminal 21 that has received the request transmits a radio activation instruction to the relay device X2. The wireless deactivation instruction is transmitted to the relay device X2 via the GW 22 and each relay device. Here, since the routing table for the relay device X2 is generated in each relay device, each relay device uses the routing table for the relay device X2 to send its wireless deactivation instruction to the relay device X2. Can be transferred.

  [Procedure 2.2] FIG. 20 shows information of the routing table 33 for each relay device 23 and the control terminal 21 of the mobile device 24 at the time of wireless activation of the relay device X2. The table on the lower side of FIG. 20 shows information of the routing table 33 for the control terminal 21 of each relay device 23 and the mobile device 24 at the time of wireless activation of the relay device X2.

  For example, the relay apparatus C is connected to the GW by wireless ad hoc communication with subgroup ID = 1.

  The relay device B is connected to the relay device C by wireless ad hoc communication with subgroup ID = 1, and is connected to the maintenance mobile device X0 by wireless ad hoc communication with subgroup ID = 2. In this case, communication to the ad hoc network having a subgroup ID that matches the subgroup ID of relay device B is prioritized ("Yes" in S12, S14 in FIG. 10), so communication between relay devices B-C. Becomes effective.

  The relay device X2 is connected to the relay device B by wireless ad hoc communication with subgroup ID = 1, and is connected to the maintenance mobile device X0 by wireless ad hoc communication with subgroup ID = 2. In this case, communication to the ad hoc network having a subgroup ID that matches the subgroup ID of relay device X2 is given priority ("Yes" in S12, S14 in FIG. 10), so communication between relay devices X2-B. Becomes effective.

  The mobile device A is connected to the relay device B through wireless ad hoc communication with subgroup ID = 1, connected to the maintenance mobile device X0 through wireless ad hoc communication with subgroup ID = 2, and is connected to the relay device X2 with subgroup ID = 1. Connected by wireless ad hoc communication. Here, if the relay device X2 is closer to the mobile device A than the relay device B, the communication quality between the mobile device A and the relay device X2 is higher than the communication quality between the mobile device A and the relay device B. Is good. In this case, in the routing table 33 of the mobile device A, the record of “local destination address (LD) = X2” is higher than the record of “local destination address (LD) = B”. Accordingly, communication between the mobile device A and the relay device X2 having higher priority among the communication to the ad hoc network having the subgroup ID that matches the subgroup ID of the mobile device A is enabled (in FIG. 10, S12 "Yes", S14).

  Thereby, the ad hoc network of subgroup ID = 1 can be configured as GW → relay apparatus C → relay apparatus B → relay apparatus X2 → mobile apparatus A.

  [Procedure 2.3] After the configuration of the ad hoc network indicated by the subgroup ID = 1 is changed, as shown in the upper side of FIG. 21, the mobile device A reaches a range where the radio field intensity with the relay device X2 does not fall below the threshold. You will be able to move. This makes it possible to extend the ad hoc network.

  In addition, as shown in the lower side of FIG. 21, when the mobile device A leaves the relay device B, the Hello message from the relay device B cannot be received, and the “local destination address ( The record for “LD) = B” will be erased.

  FIG. 22 is a hardware configuration example of the node device according to the present embodiment. The microprocessor unit (MPU) 70 is responsible for various calculation processes. The MPU is communicably connected via a wired physical layer processing unit (PHY) 72 and an MII (Media Independent Interface) / MDIO (Management Data Input / Output) interface 71. “MII / MDIO” means “MII or MDIO”. Both MII and MDIO are interfaces between the physical layer and the MAC sublayer (Media Access Control sublayer). The MPU 70 is communicably connected to a timer IC 74 for measuring time and the like via an I2C (Inter-Integrated Circuit) / PIO (Parallel Input / Output) bus 73. “I2C / PIO” means “I2C or PIO”. The MPU 70 is communicably connected to a dynamic random access memory (DRAM) 76, a flash memory 77, and a wireless LAN processing unit 78 which is a network interface via a PCI (Peripheral Component Interconnect) bus 75. The MPU 70 is connected to the motor 80, the pulling mechanism 81, the camera 82, and the sensors 83 by a predetermined bus. The node device is also equipped with a rechargeable battery as a power source for supplying power to these electronic components for operation. Of course, in view of common knowledge in the technical field, devices other than the standards and types exemplified here may be used as appropriate.

  The MPU 70 can execute various processes by loading various programs such as firmware stored in the flash memory 77 which is a kind of nonvolatile storage device onto the DRAM 76 and executing the programs. For example, the MPU 70 can execute various programs such as a firmware program for causing the node to execute the various processes described above.

  The DRAM 76 can also be used as a frame transmission buffer and a reception buffer. The flash memory 77 can store a firmware program and the like. The flash memory 77 can also store information unique to the relay device and the mobile device (for example, node ID and MAC address).

  The wired PHY processing unit 72 is a circuit that performs physical layer processing in wired connection. The wireless LAN processing unit 78 is hardware that performs physical layer processing in wireless LAN connection. The wireless LAN processing unit 78 can include, for example, an antenna, an ADC (Analog-to-Digital Converter), a DAC (Digital-to-Analog Converter), a modulator, a demodulator, and the like. I do.

  The timer IC 74 is a circuit that performs a count-up operation until a set time elapses, and outputs an interrupt signal when the set time elapses.

  In the above-described embodiment, the node device has been mainly described. However, a control program that causes a computer to execute the above-described method is also included in the example of the present embodiment. The control program may be provided by being stored in a computer-readable storage medium such as a magnetic disk, a magneto-optical disk, a nonvolatile semiconductor memory, or an optical disk, loaded into a computer, and executed by the computer.

  The motor 80 is a drive unit used in a servo mechanism that automatically operates so as to follow a target value, using the wheel drive mechanism and the position, orientation, orientation, and the like of the moving device 24 as control amounts. The traction mechanism 81 is a mechanism for connecting and towing the relay device. In the case of the moving device 24, a detaching mechanism for detaching the towing relay device is provided. The camera 82 is mounted on the moving device 24 and is used for imaging a subject. The sensors 83 include various sensors such as a temperature sensor, a pressure sensor, an optical sensor, an infrared sensor, and a radiation sensor.

  A computer that executes the control program is built in or connected to a node device (not shown), and the node device (not shown) is operated according to the control program so that the node device (not shown) operates in the same manner as the node device of the embodiment. Controls node equipment.

  In this embodiment, an example of a table format is disclosed for easy understanding of various types of data. However, the present invention is not limited to this example, and XML (Extensible Markup Language) or a tree structure that can manage data in association with each other The management format may be adopted.

  According to the present embodiment, the maintenance mobile device can maintain the wireless ad hoc network so that the topology does not change, and the following effects can be expected. Equipped with various sensors that can move while automatically laying wireless ad hoc communication equipment even in places where people can not reach radio waves (complex structures / underground / radioactively contaminated spaces / buildings that are likely to break down) Maintenance can be performed even after the device has been sent. In addition, when a problem or necessity of battery replacement occurs in a node of a wireless ad hoc communication device that has already been laid, it is possible to specify the location of the node and approach it so that the node replacement work can be performed remotely. It becomes. The position of an arbitrary node in the installed wireless ad hoc communication network can be specified and approached, and the wireless ad hoc communication network can be extended therefrom.

  The present invention is not limited to the above-described embodiment, and various configurations or embodiments can be taken without departing from the gist of the present invention.

10, 10a Node device 11 Storage unit 12 Reception unit 13 Determination unit 14 Transmission unit 21 Control terminal 22 GW
DESCRIPTION OF SYMBOLS 23 Relay apparatus 24 Mobile apparatus 25 Data generation relay process part 26 Route report part 27 Affiliated group change part 28 Data transmission process part 29 Ad hoc protocol process part 30 Wireless interface part 31 Data reception process part 32 Priority group selection part 33 Routing table 34 Link Table 35 Configuration DB
36 Memory

Claims (9)

A node device that constructs a wireless communication network by performing wireless communication between adjacent node devices,
A storage unit for storing first subgroup identification information which is identification information for identifying a subgroup for identifying a group formed in the wireless communication network and is identification information assigned to the own node device;
A receiving unit that receives communication information including second subgroup identification information assigned to a source node device from one or more other node devices;
A node device as a transmission destination is determined from the one or more other node devices according to a result of collation between the first subgroup identification information and the second subgroup identification information included in the received communication information. A decision unit;
A transmitter that transmits the communication information including the first subgroup identification information to the determined transmission destination;
A node device comprising: The determination unit stores transmission destination candidate information in which a transmission destination candidate indicated by the transmission source node device of the received communication information is associated with the second subgroup identification information of the transmission destination candidate. The transmission destination candidate having the second subgroup identification information that matches the first subgroup identification information is determined as the transmission destination from the route information regarding the transmitted transmission path. Node equipment. The determination unit stores transmission destination candidate information in which a transmission destination candidate indicated by the transmission source node device of the received communication information is associated with the second subgroup identification information of the transmission destination candidate. When the route information regarding the transmitted route does not include subgroup identification information that matches the first subgroup identification information, the transmission destination candidate to the transmission destination is determined according to the communication environment of the transmission destination candidate. The node device according to claim 1, wherein the node device is determined. The node apparatus according to any one of claims 1 to 3, wherein the path information stores the transmission destination candidate information in the order of priority given to the subgroup identification information. To a node device that constructs a wireless communication network by performing wireless communication between adjacent node devices,
Reading out, from the storage device, first subgroup identification information which is identification information for identifying a subgroup for identifying a group formed in the wireless communication network and is identification information assigned to the own node device;
Receiving communication information including second subgroup identification information assigned to the source node device from one or more other node devices;
In accordance with a collation result between the first subgroup identification information and the second subgroup identification information included in the received communication information, a node device as a transmission destination is determined from the one or more other node devices. ,
A node control program that causes a process of transmitting the communication information including the first subgroup identification information to the determined transmission destination. When the determination is made, transmission destination candidate information in which the transmission destination candidate indicated by the transmission source node device of the received communication information and the second subgroup identification information of the transmission destination candidate are related to each other is obtained. The transmission destination candidate having the second subgroup identification information that matches the first subgroup identification information is determined as the transmission destination from the stored route information regarding the transmission route. The node control program described. When the determination is made, transmission destination candidate information in which the transmission destination candidate indicated by the transmission source node device of the received communication information and the second subgroup identification information of the transmission destination candidate are related to each other is obtained. When the stored route information regarding the transmission route does not include subgroup identification information that matches the first subgroup identification information, the transmission destination candidate transmits the transmission information according to the communication environment of the transmission destination candidate. The node control program according to claim 5, wherein the destination is determined. The node control program according to any one of claims 5 to 7, wherein the path information stores the transmission destination candidate information in the order of priority given to the subgroup identification information. A method of controlling a network topology of a wireless communication network constructed by performing wireless communication between adjacent node devices,
The node device is identification information for identifying a subgroup for identifying a group formed in the wireless communication network, and the first subgroup identification information assigned to the own node device and one or more other node devices When the sub-group identification information assigned to the source node device included in the communication information received from the mobile node matches the other node device, the wireless communication network is constructed.
When a movable node device assigned with the second subgroup identification information passes through the area of the wireless communication network constructed by the node device assigned with the first subgroup identification information, the wireless communication A network topology control method characterized in that each node device that constructs a network maintains a connection form of the wireless communication network by transmitting and receiving communication information including the first subgroup identification information.

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