JP6009814B2 - Core radio, radio, multi-hop communication system, and communication program - Google Patents

Description

  The present invention relates to a backbone radio device, a radio device, a multi-hop communication system, and a communication program, and relates to an apparatus, a system, and a program that perform communication by forming a radio communication path.

  Multi-hop communication systems that transmit packets by relay transmission of a plurality of wireless devices are widely used. A communication path of a multi-hop communication system includes a tree shape in which one of a plurality of wireless devices serves as a starting node and another wireless device serves as a branch node or a terminal node. The starting node forms the root of a tree shape. The branch node forms a tree-shaped branch point, and the end node forms the end of the tree shape. In general, information that defines a tree-shaped communication path is stored in a radio of an origin node, and the radio of the origin node performs control related to packet routing.

  In addition, some communication paths of a multi-hop communication system have a mesh shape in which a plurality of wireless devices are connected in a mesh pattern. In general, information that defines a mesh-shaped communication path is stored in each radio such that each radio stores an ID (Identification) of a radio adjacent to the communication path.

  Patent Document 1 below describes such a multi-hop communication system. In this system, route information that defines a communication route is generated by a parent node. The communication path between child nodes has a mesh shape. There are a plurality of communication paths from the child node to the parent node, and a communication path having a good communication status is selected from these.

JP 2011-223442 A

  In a multi-hop communication system, when information is transmitted from one wireless device to another wireless device, one is selected from a plurality of communication paths. In a system in which a mesh-shaped communication path is formed, a plurality of wireless devices are involved in the process of selecting a communication path, and the process is complicated. On the other hand, in a system in which a tree-shaped communication path is formed, the wireless device at the origin node selects the communication path. This simplifies the process of selecting a communication path. However, when the communication status of the communication path corresponding to one branch of the tree shape is not good, the communication status of the entire system is affected.

  An object of the present invention is to easily configure a communication path of a multi-hop communication system and to improve communication performance.

The present invention is a backbone wireless device that performs wireless communication with a plurality of wireless devices, and the plurality of wireless devices is a tree having the backbone wireless device as a starting node and each wireless device as a branch node or a terminal node. A plurality of communication paths having a shape are formed, and the basic wireless device is a basic wireless device adjacent to the basic wireless device side on the communication route, and the first wireless device and the second wireless device are individually connected to each wireless device. The path information associated with the communication status recognition unit for recognizing the communication status in the communication route, the route information is referred to based on the communication status in the communication route, and the first radio or the first for each radio It is formed by a selection unit that selects any one of a plurality of communication paths by individually selecting one of the two wireless devices as the backbone device, and the backbone device selected for each wireless device communication Includes a packet transmission unit that transmits packets to the road, and the route information, characterized in that it is a data communication path is indicated by following the base-side machine which is selected for each radio.

In addition, in the backbone wireless device according to the present invention, preferably, the communication status recognition unit cannot transmit a packet to a terminal side of a communication path from a packet received from among the plurality of wireless devices. When the communication status recognition unit acquires the communication disabled information, the selection unit refers to the route information and switches to the switching point wireless adjacent to the terminal side of the wireless device that has received the packet. switching the base-side machine for machine, from the switching point radios up to the backbone radios, selects a communication path indicated by following the base-side apparatus selected for each radio.

Further, in the basic radio according to the present invention, preferably, the communication status recognition unit determines whether it is possible to transmit a packet to a radio adjacent to the end side of the basic radio, When it is determined that the packet cannot be transmitted, the selection unit refers to the path information and is selected for the switching point radio adjacent to the terminal side of the backbone radio. The communication path indicated by tracing the backbone side selected for each wireless device is selected from the switching point wireless device to the backbone wireless device .

  In addition, the present invention is characterized by comprising the backbone radio device and the plurality of radio devices.

Further, the present invention is a wireless device that constitutes one of a plurality of wireless devices that perform wireless communication with a core wireless device, and the plurality of wireless devices have the core wireless device as a starting node. A plurality of tree-shaped communication paths having each radio as a branch node or a terminal node are formed, and each radio has a first radio and a first radio as adjacent trunks on the side of the backbone radio on the communication path. 2 wireless devices, subordinate route information individually associated with each wireless device on the terminal side, communication status recognition unit for recognizing the communication status in the communication route, By referring to the subordinate route information based on the communication status in the communication route, and selecting each of the first wireless device and the second wireless device as the backbone device individually for each wireless device, a plurality of ways A selection unit that selects one of the communication paths, and a packet transmission unit that transmits a packet to a communication path formed by the backbone side machine selected for each wireless device, and the subordinate route information includes It is information indicating a communication path by tracing the trunk side machine selected for the radio equipment.

In the wireless device according to the present invention, preferably, the communication status recognition unit included in the wireless device can transmit a packet to a wireless device adjacent to a terminal side of the wireless device. The selection unit included in the wireless device determines that it is not possible to transmit a packet, and switches the backbone side device selected for any one of the wireless devices on the terminal side of the wireless device. Thus, when a new communication route from the wireless device to the destination wireless device is formed, the backbone side device selected for the terminal-side wireless device is switched and the new communication route is selected. .

Further, the present invention is a communication program that is read into a core radio that performs wireless communication with a plurality of radios, and the plurality of radios branch from each radio using the core radio as a starting node. A plurality of tree-shaped communication paths that are nodes or terminal nodes are formed, and the basic wireless device is a basic wireless device adjacent to the basic wireless device side on the communication route, and the first wireless device and the second wireless device are has a routing information associated individually for each radio, the communication program, referring to the route information based on a communication status of a communication path and processing for recognizing, the communication status of the communication path, For each radio, a process for selecting any one of a plurality of communication paths by individually selecting either the first radio or the second radio as the backbone side machine for each radio, and One Processing to transmit a packet to a communication path formed by the selected main unit, and the route information is obtained by tracing the main unit selected for each wireless device. It is information that indicates a communication path .

In addition, the present invention is a communication program that is read by a wireless device that constitutes one of a plurality of wireless devices that perform wireless communication with a backbone wireless device , wherein the plurality of wireless devices are the backbone wireless devices. A plurality of tree-shaped communication paths with each machine as a starting node and each radio as a branch node or terminal node are formed, and each radio is designated as a trunk side machine adjacent to the backbone radio on the communication path. 1 wireless device and 2nd wireless device have subordinate route information individually associated with each wireless device on the terminal side, and the communication program recognizes the communication status in the communication route ; By referring to the subordinate route information based on the communication status in the communication route, and selecting each of the first wireless device and the second wireless device as the backbone device individually for each wireless device, a plurality of ways Through A process of selecting any one of the paths and a process of transmitting a packet to a communication path formed by the backbone side machine selected for each wireless device are executed by the wireless device, and the subordinate route information is It is information indicating a communication path by tracing the backbone side machine selected for each radio.

  According to the present invention, it is possible to easily configure a communication path and improve communication performance.

It is a figure which shows the structural example of the multihop communication system which concerns on this invention. It is a figure which shows a path | route information table. It is a figure which shows the structural example of a main | base station. It is a figure which shows the structural example of a subunit | mobile_unit. It is a figure which shows the communication path | route and path | route information table of the subunit | mobile_unit C1 and C2. It is a figure which shows the communication path | route and path | route information table of the subunit | mobile_unit C1-C5. It is a figure which shows the subordinate table of the subunit | mobile_unit C1-C3. It is a figure which shows the subordinate table of the subunit | mobile_unit C4-C6. It is a figure which shows the subordinate table of the subunit | mobile_unit C7 and C8. It is a figure which shows the structural example of the packet for data transmission.

1. Overview of Configuration of Multihop Wireless System FIG. 1 shows a configuration example of a multihop communication system according to an embodiment of the present invention. The multi-hop communication system includes a parent device P0 and child devices C1 to C8 as a plurality of wireless devices. The multi-hop communication system is used for a telemeter system, for example. In this case, the subunit | mobile_unit C1-C8 is provided in measuring instruments in the position distant from main | base station P0, such as a water meter, a gas meter, and an electric energy meter, and acquires a measured value. Master device P0 causes slave devices C1 to C8 to transmit packets by multi-hop communication, and collects measurement values from each slave device.

  Master device P0 and slave devices C1 to C8 form a preferential route represented by a solid line in FIG. 1 as a preferential communication route, and form an auxiliary route represented by a broken line in the figure as an auxiliary communication route. To do. The priority route is used in the normal time, and the auxiliary route is used when the communication status of the priority route is not good.

  Here, the state where the communication path is formed refers to a state where a wireless device (parent device) adjacent to the parent device side is determined for each child device. For the slave unit that directly performs wireless communication with the master unit, the master unit is the master unit. Further, for the slave unit in which another slave unit for relay is interposed between the master unit and the slave unit, the other slave unit for relay is the master unit. In this embodiment, in order to form two types of communication paths, a priority path and an auxiliary path, a priority / parent side machine and an auxiliary / parent side machine are determined as two parent side machines for each slave unit. Has been. The point attached to the side of the straight line indicating the priority route and the auxiliary route in FIG. 1 is that the wireless device on the side to which the point is attached determines the wireless device on the side to which the point is not attached as the parent device. It is shown that.

  When the transmission destination ID described in the packet received from the other wireless device matches its own ID, the parent device and the child device execute processing for the packet and receive it from the other wireless device. When the transmission destination ID described in the packet does not match its own ID, the process for the packet is not executed. Therefore, in the wireless device that transmits the packet, the transmission destination ID according to the communication path is set, so that the packet is transmitted along the communication path.

  Focusing only on the priority route, in the multi-hop communication system according to the embodiment of the present invention, the parent device P0 is a starting node, the child devices C1, C2, C3, and C6 are branch nodes, and the child device C4 , C5, C7, and C8 can be said to be formed as a tree-shaped communication path.

  Base unit P0 stores a route information table indicating a communication route. FIG. 2 shows a route information table corresponding to the communication route shown in FIG. Here, ID0 is assigned to the parent device P0, and ID1 to ID8 are assigned to the child devices C1 to C8, respectively. In the route information table, priority / parent-side machine IDs and auxiliary / parent-side machine IDs are associated with the IDs of the two parent machines as the IDs of the two parent machines.

  When transmitting a packet, the parent device refers to the route information table and determines a communication route to reach the packet destination child device. Unless the route switching process described later is executed, the parent device refers to the priority / parent device ID associated with the ID of each child device, and determines the communication route.

  For example, when transmitting a packet to the child device C6, the parent device P0 acquires ID3 associated with ID6 as the priority / parent device ID. Then, ID1 associated with ID3 as the priority / parent device ID is acquired, and further, ID0 of the parent device P0 associated with ID1 as the priority / parent device ID is acquired. Accordingly, the parent device P0 determines a communication route from the child device C1 through the child device C3 to the child device C6 as a communication route for transmitting a packet to the child device P6. Base unit P0 includes in the packet information indicating that the packet should be transmitted through this communication path, transmits the packet to handset C1, causes handset C1 and C3 to relay, and sets handset C6 to the packet. Send.

2. Configuration of Main Unit and Sub Unit FIG. 3 shows a configuration example of the main unit P. Base unit P includes base unit control unit 10, base unit transmission / reception unit 12, interface 20, and memory 14. The base unit control unit 10 executes processing according to the base unit communication program 18 stored in the memory 14. Base unit control unit 10 generates a packet and causes base unit transmission / reception unit 12 to transmit the packet. Further, base unit control unit 10 acquires a packet received by base unit transmission / reception unit 12 and executes processing on the packet. The interface 20 connects an external computer 22 to the parent device control unit 10. Based on the control of the computer 22, the base unit control unit 10 may refer to the route information table 16 stored in the memory 14 and execute processing related to packet routing.

  FIG. 4 shows a configuration example of the slave unit C. The subunit | mobile_unit C is provided with the subunit | mobile_unit control part 26, the subunit | mobile_unit transmission / reception part 28, the measuring device 24, and the memory 30. FIG. The slave unit control unit 26 executes processing according to the slave unit communication program 34 stored in the memory 30. The subunit | mobile_unit control part 26 acquires the packet which the subunit | mobile_unit transmission / reception part 28 received, and performs the process with respect to the packet. Moreover, the subunit | mobile_unit control part 26 produces | generates a packet, and makes the subunit | mobile_unit transmission / reception part 28 transmit a packet. When transmitting the measurement value acquired by the measuring instrument 24, the subunit | mobile_unit control part 26 reads a measured value from the measuring instrument 24, and describes the measured value in a packet. Then, the slave unit transmitting / receiving unit 28 transmits the packet. The memory 30 stores a subordinate table 32 (to be described later) in addition to the priority / parent device ID 36 and the auxiliary / parent device ID 38.

  The parent device control unit 10 of the parent device P and the child device control unit 26 of the child device C perform control related to packet transmission and reception, whereby each process in the multihop communication system described below is executed.

3. Route Formation Processing (1) Purpose of Route Formation Processing In the multi-hop communication system according to the present embodiment, packets are transmitted according to a communication route, and communication is performed between the parent device and each child device. The parent device receives the packet transmitted from each child device and collects information from each child device. Before such packet transmission is performed, it is necessary to form a communication path and store the contents of the path information table in the parent device. Therefore, in the multi-hop communication system according to the present embodiment, the following route formation process is executed.

(2) Determining the first-layer child device First, the parent device broadcasts (sends broadcast) a search packet in order to determine the first-layer child device having itself as the parent device. Here, the slave device in the n-th layer is a slave device having n-1 relays to the master device along the priority route.

  The slave unit that has received the search packet transmits a subscription request packet to the master unit as a packet in response to the search packet. When the base unit receives the join request packet, the base unit acquires the ID of the transmission source included therein, associates the ID of the base unit with the acquired ID as a priority / master unit ID, and stores this correspondence in the route information table. sign up. The master unit transmits a join response packet to the slave unit that has transmitted the join request packet. The child device that has received the join response packet stores the ID of the transmission source included therein as the priority / parent device ID, and completes the determination of the priority / parent device.

  Note that the slave unit whose received signal level of the search packet does not satisfy the predetermined threshold does not transmit the join request packet. In addition, when the reception signal level of the subscription request packet is less than a predetermined threshold, the base unit does not execute processing for the subscription request packet. This limits the number of first-level child devices.

  In FIG. 5A, the slave units C1 and C2 are determined as the slave units in the first hierarchy, and are preferentially between the master unit P0 and the slave unit C1 and between the master unit P0 and the slave unit C2. The way the path is formed is shown. FIG. 5B shows a route information table that the parent device P0 has at this stage.

(3) Determination of second-layer child device and formation of auxiliary route Next, the parent device transmits a search command packet to each child device in the first layer. The first-layer child device that has received the search command packet determines the second-layer child device that has its own priority / parent device and the child device that has its own auxiliary / parent device. Broadcast.

  The slave unit that has received the search packet from the first-level slave unit and has not determined the priority / master unit sets the join request packet as the first response source packet as a response packet to the search packet. Send to the slave unit in the hierarchy. The first-layer child device acquires the ID included in the subscription request packet, associates the acquired ID with the ID as a priority / parent-side device ID, and registers the ID in its own subordinate table.

  Here, the subordinate table refers to a table indicating path information regarding other slave units located on the end side of itself. The subordinate table corresponds to a correspondence relationship related to another slave unit located on the end side of the subordinate table extracted from the route information table of the master unit.

  After updating the subordinate table, the first-layer slave unit transmits a join response packet to the slave unit that has transmitted the join request packet. The child device that has received the join response packet stores the ID of the transmission source included therein as the priority / parent device ID, and completes the determination of the priority / parent device.

  On the other hand, the slave unit that has received the search packet from the first layer slave unit and has already determined the priority / master side unit sets the auxiliary / subscription request packet as a packet in response to the search packet. The data is transmitted to the first-level slave unit of the transmission source. The first-layer child device acquires the ID included in the auxiliary / subscription request packet, associates the acquired ID with the ID as the auxiliary / parent device ID, and registers the ID in the subordinate table. The first-layer child device transmits an auxiliary / subscription response packet to the child device that transmitted the auxiliary / subscription request packet. The child device that has received the auxiliary / subscription response packet stores the ID of the transmission source included therein as the auxiliary / parent device ID, and completes the determination of the auxiliary / parent device.

  The child device that has determined the child device in the first hierarchy as the auxiliary / parent device transmits the contents of its own subordinate table to the child device in the first hierarchy as the auxiliary / parent device. In response to this, the child machine in the first hierarchy updates its subordinate table.

  Note that a slave unit whose received signal level of a search packet broadcast from a slave unit in the first layer does not satisfy a predetermined threshold does not transmit a join request packet or an auxiliary / subscribe request packet. In addition, when the reception signal level of the join request packet or the auxiliary / subscription request packet is less than a predetermined threshold, the first layer slave unit performs processing for the join request packet or the auxiliary / subscription request packet. Do not execute. As a result, the number of second-layer child devices and the number of child devices that use the first-layer child devices as auxiliary / parent devices are limited.

  Each slave unit in the first layer updates the subordinate table, and then transmits a response packet to the master unit as a response to the search command packet. This response packet includes information related to the subordinate table of each slave unit in the first layer. The master unit that has received the response packet updates the route information table based on the response packet.

  In FIG. 6A, the child devices C3, C4 and C5 are determined as the child devices of the second hierarchy, and between the child device C1 and the child device C3, between the child device C1 and the child device C4, and A state in which a preferential path is formed between the child device C2 and the child device C5 is shown. Furthermore, it is shown that the child device C2 is determined as the auxiliary / parent device for the child device C1, and the child device C1 is determined as the auxiliary / parent device for the child device C2. FIG. 6B shows a route information table that the parent device P0 has at this stage.

(4) Determination of third-layer child device and formation of auxiliary route Next, the parent device transmits a search command packet to each second-layer child device by relaying each first-layer child device. To do. The second-layer child device that has received the search command packet determines the third-layer child device that has its own priority / parent device and the child device that has its own auxiliary / parent device. Broadcast.

  Then, the second-layer child device updates its subordinate table through a process similar to the process executed by the first-layer child device. Then, after updating the subordinate table, the response packet is transmitted to the parent device through the relay of the first layer child device. This response packet includes information related to the subordinate table of each child device in the second layer. Each slave device in the first layer that relays the response packet updates its subordinate table based on the response packet. Further, the master unit that has received the response packet updates the route information table based on the response packet.

(5) Summary As described above, the master unit broadcasts the search packet, receives the subscription request packet from the slave unit, and determines the first-level slave unit that uses itself as the priority / master unit. Further, when determining the second and subsequent child devices, the parent device transmits a search command packet by relaying the child devices in a higher hierarchy. In response to this, the slave unit of the hierarchy determined last broadcasts the search packet, receives the join request packet, and transmits the join response packet, and determines the slave unit of the lower hierarchy. Further, it receives the auxiliary / subscription request packet and transmits the auxiliary / subscription response packet, and determines the slave unit that uses itself as the auxiliary / parent unit.

  The slave device in the first layer transmits the response packet directly to the master device, and the slave device in each layer lower than the second layer transmits the response packet to the master device by relaying the slave device in the upper layer, and receives the response packet The parent device updates the route information table. In addition, the slave unit in each layer that relays the response packet updates the subordinate table.

  In addition, the child device that has determined the auxiliary / parent device transmits the contents of its subordinate table to the auxiliary / parent device. In response to this, the auxiliary / parent device updates its subordinate table or route information table.

  From the viewpoint of the process executed by each slave unit that has received the search packet, this process is described as follows. When the priority / master unit has not been determined, the slave unit determines the master unit that has transmitted the search packet or the slave unit in the higher hierarchy as the priority / master unit by receiving the search packet, Alternatively, a subscription request packet is transmitted to the upper layer slave unit. Then, by receiving the join response packet transmitted as a response to the join request packet, the priority / master device ID is acquired and stored.

  When the priority / master unit has already been determined, the slave unit determines the master unit or slave unit that has transmitted the search packet by receiving the search packet as an auxiliary / master unit, and sets the auxiliary / subscribe request packet. Send. Then, by receiving the auxiliary / subscription response packet transmitted as a response to the auxiliary / subscription request packet, the auxiliary / parent device ID is acquired and stored.

  That is, each of the slave units that receive the search packet selects one of the master unit (core radio unit) and a plurality of other slave units (relay units) that form a communication path for the master unit on the communication path. An auxiliary / parent device that is determined as a priority / parent device (first backbone device) adjacent to the parent device side and that is not determined as a priority / parent device is adjacent to the parent device side on the communication path. The slave unit control unit includes a determination unit that determines a side unit (second backbone side unit).

  By the route formation process, the parent device updates the route information table, and each child device updates its subordinate table. Thereby, the preferential communication path and the auxiliary communication path shown in FIG. 1 are formed, and the path information table shown in FIG. 2 is stored in the parent device P0. Further, in the state where the communication path shown in FIG. 1 is formed, the slave units C1 to C8 are respectively connected to FIGS. 7 (C1) to (C3), FIG. 8 (C4) to (C6), and FIG. 9 Subordinate tables shown in (C7) and (C8) are stored.

(6) Formation of a communication path based on the number of relays Each slave unit may execute processing for preferentially determining another slave unit having the smallest number of relays to the master unit as the master unit. In this case, it is assumed that the search packet includes a numerical value indicating the number of relays between the slave unit that broadcasts the search packet and the master unit.

  The base unit includes 0 as the number of relays in the broadcast search packet. Further, each slave unit in the first layer or lower includes a numerical value obtained by adding 1 to the number of relays to the base unit in the broadcast search packet as the number of relays. The slave unit that has received the search packet obtains the number of relays to the base unit when the slave unit that is the transmission source of the search packet is the master unit, based on the relay count included in the search packet.

  The slave unit that has received the search packet has a lower number of relays to the master unit, even if the priority / master unit or auxiliary / master unit has already been determined. If the side machine can be decided, the previous decision is canceled and the priority / parent side machine or auxiliary / parent side machine is decided again. Along with this, the subordinate table possessed by the slave unit in the higher hierarchy and the route information table possessed by the master unit are updated.

  When such a process is executed, the communication path to be formed is unsatisfactory, for example, the wireless devices at both ends of the communication path do not recognize each other's IDs and recognize incorrect IDs only by executing the path forming process once. May be complete. For this reason, the route forming process may be executed a plurality of times to converge the contents of each table, and the process for uniquely forming the communication route may be executed.

(7) Process for Determining Multiple Auxiliary / Master Units In the above description, the process for each slave unit to determine one auxiliary / master unit has been described. In addition to such a configuration, each slave unit may employ a process for determining a plurality of auxiliary / master units. In this case, each slave unit determines the second and subsequent auxiliary / master units by receiving the search packet even if the first auxiliary / master unit has already been determined. . In this case, in the route information table and the subordinate table, the IDs of the slave units are associated with the IDs of a plurality of auxiliary / master units.

4). Packet Transmission Process (1) Data Transmission Packet A process in which the master unit transmits a data transmission packet to the destination slave unit will be described. Packets for data transmission include packets for the purpose of route formation such as the search packet, the subscription request packet, the subscription response packet, the auxiliary / subscription request packet, the auxiliary / subscription response packet, the search command packet, and the response packet. Is a packet intended for data transmission.

  FIG. 10 shows a configuration example of a data transmission packet. The data transmission packet includes a transmission source ID description part, a transmission destination ID description part, a control information description part, a communication path information description part, and a data description part.

  In the transmission source ID description part, the ID of the wireless device that is the transmission source of the data transmission packet is described as the transmission source ID. In the transmission destination ID description section, the ID of the wireless device that is the transmission destination of the data transmission packet adjacent on the communication path is described as the transmission destination ID.

  In the control information description section, information for controlling the wireless device that has received the data transmission packet is described. In the communication path information description portion, communication path information indicating a path through which the data transmission packet is transmitted is described. The communication path information includes, for example, a parent device P0 as a data transmission packet transmission source, such as (ID0, ID1,..., IDj,... IDn), and a slave device that relays the data transmission packet. It is assumed that each of C1... Cj. Arbitrary data to be transmitted is described in the data description part.

(2) Transmission of Data Transmission Packet First, the parent device refers to the route information table, determines a communication route to the destination child device of the data transmission packet, and generates communication route information. That is, the priority / parent device ID associated with the destination ID, the priority / parent device ID associated with the same ID as the priority / parent device ID, and the priority / parent device ID A priority / parent device ID associated with the same ID is acquired by tracing the priority / parent device ID in order, and a series of IDs until the parent device's own ID is acquired. get.

  For example, a case where the parent device P0 transmits a packet with the child device C6 as a destination will be described. The parent device refers to the route information table shown in FIG. 2 and acquires ID3 associated with ID6 as the priority / parent device ID. Then, ID1 associated with ID3 as the priority / parent device ID is acquired. Furthermore, ID0 of the parent device associated with ID1 as the priority / parent device ID is acquired. As a result, the parent device P0 determines a communication route that reaches the child device C6 via the child devices C1 and C3 as a communication route for transmitting the data transmission packet to the child device C6, and generates communication route information. According to the above example, the communication path information is (ID0, ID1, ID3, ID6).

  The base unit generates a data transmission packet, describes its own ID in the transmission source ID description part, and describes the ID described next to its own ID in the communication path information in the transmission destination ID description part. In addition, information for controlling the transmission destination slave unit is described in the control information description part, and communication path information is described in the communication path information description part. Then, the data to be transmitted is described in the data description part. The base unit transmits a data transmission packet in which necessary information is described in each description unit.

(3) Relay of data transmission packet and acquisition of data in destination slave unit When the destination unit does not match its own ID, the slave unit that has received the data transmission packet receives the data transmission packet The process for is not executed. On the other hand, when the transmission destination ID matches its own ID, the following processing is executed.

  (A) When the ID described at the end of the communication path information matches its own ID, the slave unit acquires data described in the data description part of the data transmission packet. As a result, data is acquired by the destination slave unit.

  (B) On the other hand, if the ID described at the end of the communication path information does not match the own ID, describe the own ID in the transmission source ID description section, and next to the own ID in the communication path information. The described ID is described in the transmission destination ID description part, and the description content of the received data transmission packet is changed. Then, the data transmission packet whose description content is changed is transmitted. As a result, the slave unit that is not the destination of the data transmission packet relays the received data transmission packet.

  According to such processing, the data transmission packet transmitted from the parent device is relayed on the communication route according to the communication route information and received by the destination child device. The destination child device acquires data described in the data description portion of the data transmission packet.

  For example, when the parent device P0 transmits a packet with the child device C6 as a destination, relay transmission according to the communication path information (ID0, ID1, ID3, ID6) is performed. That is, the data transmission packet transmitted from the parent device P0 is relayed by the child device C1 and the child device C3 and received by the child device C6. The subunit | mobile_unit C6 acquires the data described in the data description part of the data transmission packet.

(4) Acknowledgment processing The slave unit receives the data transmission packet, and when the transmission destination ID and its own ID match, and when the processing for the data transmission packet is completed, An acknowledge packet is transmitted to the transmission source.

  That is, the slave unit transmits an acknowledge packet using the transmission source ID of the data transmission packet as the destination ID. The master device or slave device that has received the acknowledge packet and that is the transmission source of the data transmission packet recognizes that the transmission data transmission packet transmitted by the device itself has been received and that processing has been executed. Such an acknowledge process is applied to a path switching process described later.

5. Process for collecting measured values When the multi-hop communication system according to the present embodiment is used in a telemeter system, each slave unit is provided in a measuring instrument located at a position away from the master unit, such as a water meter, a gas meter, and an electric energy meter. , Get the measured value. The order in which the measurement values are collected from each slave unit is, for example, the order in which the number registered as the priority / master unit in the route information table is large.

  The master unit transmits a data transmission packet destined for the slave unit from which the measured value is collected. In the data description portion of the data transmission packet, reply command information indicating that the measurement value should be returned is described. The destination slave unit, that is, the reply slave unit, after receiving the data transmission packet, generates a reply data transmission packet according to the reply command information described in the data description part. The reply slave unit describes the measurement value in the data description part of the data transmission packet. Then, describe the contents of the transmission destination ID description part and the communication path information description part so that the data transmission packet is transmitted through the communication path opposite to the communication path from the master unit to the reply slave unit. Send a data transmission packet.

  The master unit that has received the data transmission packet for reply acquires the measurement value described in the data description part. The master unit performs the same process on the other slave units and collects the measured values from each slave unit.

6). Path formation polling The process in which the master unit collects the measurement values from each slave unit may be executed together with the path formation process. In this case, each slave unit includes a measured value in a join response packet transmitted to the master unit or slave unit that is the priority / master unit. Further, the measurement value is included in the auxiliary / subscription response packet transmitted to the parent device or the child device serving as the auxiliary / parent device. Further, the slave unit that transmits the response packet includes the measurement value of the subordinate slave unit in the response packet. The master unit acquires the measurement value of the slave unit from the join response packet, the auxiliary / join response packet, and the response packet.

  According to such route formation polling, it is not necessary to separately execute processing for collecting measurement values after the processing for forming a communication route is completed, and the processing for collecting the measurement values from each child device by the parent device is simplified. It becomes.

7). Route Switching Process (1) Route Switching Process by Master Unit As described above, each slave unit transmits an acknowledge packet to the transmission source of the data transmission packet when the processing for the data transmission packet is completed. When receiving the acknowledge packet, the parent device or the slave device that is the transmission source of the data transmission packet recognizes that the data transmission packet transmitted by itself is received and the processing for the packet is executed.

  On the other hand, when the master device or slave device that is the transmission source of the data transmission packet does not receive the acknowledge packet, it recognizes that the processing for the data transmission packet that it has transmitted is not executed. Then, the route switching process described next is executed.

(A-1) First, a case where the transmission source of the data transmission packet is a slave unit and the slave unit does not receive an acknowledge packet after transmission of the data transmission packet will be described. In this case, a slave unit that has not received an acknowledge packet (hereinafter referred to as a communication interrupted slave unit) transmits an incommunicable packet with the master unit as the destination.

  The incommunicable packet includes incommunicable information indicating that the communication interrupted handset is not executing processing for the data transmission packet in the destination handset. The configuration of the incommunicable packet may be the same as that of the data transmission packet. In this case, the communication description information is described in the data description section, and further, the communication path information included in the data transmission packet that has not been processed at the transmission destination is described as the disabled / communication path information. In the communication path information description section, communication path information indicating a communication path opposite to the communication path from the parent device to the communication interrupting device is described.

  For example, a data transmission packet in which (ID0, ID1, ID3, ID6, ID8) is described as communication path information is transmitted from the parent device, relayed by the child device C1, and then the child device C3 receives the data transmission packet. An example of reception and transmission will be described.

  If the data transmission packet transmitted from the child device C3 is received by the child device C6 and the subsequent processing is executed, the child device C3 should receive the acknowledge packet transmitted from the child device C6. . However, if the communication status is not good, such as radio wave interference between the slave unit C3 and the slave unit C6, the slave unit C3 may not receive an acknowledge packet.

  In this case, the child device C3 transmits a communication impossible packet destined for the parent device P0 as a communication interruption device. Communication path information (ID3, ID1, ID0) is described in the communication path information description part of the incommunicable packet. Further, in the data description part, (ID0, ID1, ID3, ID6, ID8) is described as disabling / communication path information in addition to the disabling communication information.

  The master unit that has received the incommunicable packet transmitted from the communication disruption unit acquires the ID of the transmission source, that is, the ID of the communication disruption unit, from the communication path information of the incommunicable packet. Then, in the disabled / communication path information, the ID described next to the ID of the communication breaker is acquired as the switching point ID. The parent device refers to the route information table, and the auxiliary / parent device ID associated with the switching point ID, the priority / parent device ID associated with the same ID as the auxiliary / parent device ID, and Priority / parent device ID associated with the same ID as the priority / parent device ID,..., Priority after the auxiliary / parent device ID associated with the switching point ID, The parent machine ID is acquired by tracing in sequence, and a series of IDs until the parent machine's own ID is acquired is acquired.

  The parent device generates communication path information after switching by replacing the ID before the switching point ID in the disabled / communication path information with a series of acquired IDs. The communication path information after the switching indicates a communication path in which the master unit of the slave unit having the switching point ID is switched from the communication disruption unit to the auxiliary / master unit.

  The base unit generates a new data transmission packet, describes its own ID in the transmission source ID description section, and describes the ID described next to its own ID in the communication path information after switching as the transmission destination ID description. Describe in the section. In addition, information for controlling the transmission destination slave unit is described in the control information description part, and the communication path information after switching is described in the communication path information description part. Then, the same data to be transmitted as the previously transmitted data transmission packet is described in the data description section. The base unit transmits a data transmission packet in which necessary information is described in each description unit.

  A description will be given of the above example in which the child device C3 serving as a communication breaker transmits a communication impossible packet. The base unit P0 receives the incommunicable packet transmitted from the handset C3 and relayed by the handset C1. And ID3 is acquired as ID of the subunit | mobile_unit C3 which is a communication interruption subunit | mobile_unit based on the communication path information (ID3, ID1, ID0) of a communication impossible packet. Base unit P0 obtains ID6 described next to ID3 as the switching point ID in the impossible / communication path information (ID0, ID1, ID3, ID6, ID8) described in the data description part of the communication impossible packet. To do.

  The parent device P0 refers to the route information table shown in FIG. 2, and acquires ID4 associated with ID6 as the auxiliary / parent device ID. Then, ID1 associated with ID4 as the priority / master device ID is acquired. Further, ID0 of the parent device P0 associated with ID1 as the priority / parent device ID is acquired.

  The parent device P0 replaces the ID before the switching point ID6 in the disabled / communication path information (ID0, ID1, ID3, ID6, ID8) with the series of acquired IDs (ID0, ID0). , ID1, ID4, ID6, ID8).

  Base unit P0 generates a new data transmission packet, describes its own ID0 in the transmission source ID description section, and sets ID1 described next to its own ID0 in the communication path information after switching as the transmission destination ID. Describe in the description section. In addition, information for controlling the transmission destination slave unit is described in the control information description part, and the communication path information after switching is described in the communication path information description part. Then, the same data to be transmitted as the previously transmitted data transmission packet is described in the data description section. Base unit P0 transmits a data transmission packet in which necessary information is described in each description section.

  As described above, the communication path information of the data transmission packet previously transmitted from the parent device P0 is (ID0, ID1, ID3, ID6, ID8), whereas the data transmission transmitted from the parent device P0 again. The communication path information of the packet for use is (ID0, ID1, ID4, ID6, ID8). That is, the communication path from the parent device P0 to the child device C8 is from the communication route from the parent device P0 to the child device C1, the child device C3, and the child device C8 by relaying the child device C8, and from the parent device P0 to the child device C1. The communication path to the child device C8 is switched by relay between the child device C4 and the child device C6. As a result, when the communication status on the communication path by the relay of the child device C3 is not good, the route from the child device C1 to the child device C6 by the relay of the child device C4 is used.

(A-2) From the viewpoint of the processing executed by the parent device, the route switching processing described here is explained as follows. Based on the communication disabling information transmitted from the communication disruption device, the master device as the backbone wireless device recognizes that the communication status in the path on the terminal side from the communication disruption device is not good. Then, with reference to the route information table, the parent device of the child device adjacent to the terminal side of the communication disruption device is switched. As a result, a new communication path is selected from a plurality of communication paths indicated by the path information table. The base unit transmits a data transmission packet to the newly selected communication path.

  That is, the master unit (core radio unit) refers to the communication status recognition unit that recognizes the communication status in the communication path, and the path information table (route information) provided in the master unit based on the communication status in the communication path. The base unit control unit includes a selection unit that selects one of the street communication paths. The master unit transmits the packet to the selected communication path.

  Further, from the viewpoint of processing executed by the slave unit adjacent to the terminal side of the communication disruption unit, the path switching processing described here is described as follows.

  As described above, the slave unit adjacent to the terminal side of the communication disruption unit is any one of the master unit (core radio unit) and a plurality of other slave units (relay units) that form a communication path to the master unit. Is determined as the priority / master side machine (first trunk side machine) adjacent to the base unit side on the communication path, and the base unit side on the communication path is determined not to be determined as the priority / master side machine. The slave unit control unit includes a determination unit that determines the auxiliary / master unit (second backbone unit) adjacent to the slave unit.

  The slave unit adjacent to the terminal side of the communication disruption unit is communicated with the master unit by a communication path based on one of the priority / master unit or auxiliary / master unit corresponding to the communication path selected by the master unit. Send and receive packets.

(B-1) Next, the case where the transmission source of the data transmission packet is the parent device and the parent device does not receive the acknowledge packet after the transmission of the data transmission packet will be described.

  In this case, the master unit that has not received the acknowledge packet sets the communication path information included in the data transmission packet that has not been processed at the transmission destination as disabled / communication path information. Then, in the disabling / communication path information, the ID described next to the parent device's own ID is acquired as the switching point ID. The parent device refers to the route information table, and the priority / parent device ID associated with the same ID as the auxiliary / parent device ID associated with the switching point ID, and the priority / parent device ID. Priority / parent device ID associated with the same ID as the priority / parent device ID,... Acquire a series of IDs until the ID of the master unit is acquired.

  The parent device generates communication path information after switching by replacing the ID before the switching point ID in the disabled / communication path information with a series of acquired IDs. The communication path information after switching indicates a communication path in which the parent device of the child device corresponding to the switching point ID is switched from the parent device to the auxiliary / parent device.

  The base unit generates a new data transmission packet, describes its own ID in the transmission source ID description section, and describes the ID described next to its own ID in the communication path information after switching as the transmission destination ID description. Describe in the section. In addition, information for controlling the transmission destination slave unit is described in the control information description part, and the communication path information after switching is described in the communication path information description part. Then, the same data to be transmitted as the previously transmitted data transmission packet is described in the data description section. The base unit transmits a data transmission packet in which necessary information is described in each description unit.

  For example, an example will be described in which a data transmission packet in which (ID0, ID1, ID3, ID6, ID8) is described as communication path information is transmitted from the parent device, and the parent device has not received an acknowledge packet. The parent device sets the communication path information (ID0, ID1, ID3, ID6, ID8) included in the data transmission packet that has not been processed at the transmission destination as the disabled / communication path information. Then, in the disabled / communication path information, ID1 described after ID0 of the parent device itself is acquired as the switching point ID.

  The parent device P0 refers to the route information table shown in FIG. 2, and acquires ID2 associated with ID1 as the auxiliary / parent device ID. Then, ID0 of the parent device P0 associated with ID2 as the priority / parent device ID is acquired.

  The base unit P0 replaces the ID before the switching point ID1 in the disabled / communication path information (ID0, ID1, ID3, ID6, ID8) with the acquired ID0 and ID2, and after switching the communication path information (ID0) , ID2, ID1, ID3, ID6, ID8).

  Base unit P0 generates a new data transmission packet, describes its own ID0 in the transmission source ID description section, and sets ID2 described next to its own ID0 in the communication path information after switching as the transmission destination ID. Describe in the description section. In addition, information for controlling the transmission destination slave unit is described in the control information description part, and the communication path information after switching is described in the communication path information description part. Then, the same data to be transmitted as the previously transmitted data transmission packet is described in the data description section. Base unit P0 transmits a data transmission packet in which necessary information is described in each description section.

  Thus, while the communication path information of the data transmission packet previously transmitted from the parent device P0 is (ID0, ID1, ID3, ID6, ID8), the data transmission transmitted from the parent device P0 again. The communication path information of the packet for use is (ID0, ID2, ID1, ID3, ID6, ID8). In other words, the communication path from the parent device P0 to the child device C8 is from the communication route from the parent device P0 to the child device C1, the child device C3 and the child device C6 via the relay of the child device C8, and from the parent device P0 to the child device C2. The communication path to the child device C8 is switched by relay of the child device C1, the child device C3, and the child device C6. Accordingly, when the communication status between the parent device P0 and the child device C1 is not good, a route from the parent device P1 to the child device C1 is used by relay of the child device C2.

(B-2) From the viewpoint of processing executed by the parent device, the route switching processing described here is explained as follows. The master unit as the main radio unit recognizes that the communication status in the terminal side communication path is not good because the acknowledge packet has not been received. Then, referring to the route information table, the parent device of the child device adjacent to the terminal side from the parent device is switched. As a result, a new communication type route is selected from a plurality of communication routes indicated by the route information table. The base unit transmits a data transmission packet to the newly selected communication path.

  That is, the master unit (core radio unit) refers to the communication status recognition unit that recognizes the communication status in the communication path, and the path information table (route information) provided in the master unit based on the communication status in the communication path. The base unit control unit includes a selection unit that selects one of the street communication paths. The master unit transmits the packet to the selected communication path.

  Further, from the viewpoint of processing executed by the slave unit adjacent to the terminal side of the master unit, the path switching process described here is described as follows.

  As described above, the child device adjacent to the terminal side of the parent device (core wireless device) is either the parent device or a plurality of other child devices (relay devices) that form a communication path to the parent device. , Determined as the priority / master side machine (first trunk side machine) adjacent to the master unit side on the communication path, and further, those not determined as the priority / master unit side to the master unit side on the communication path The slave unit control unit includes a determination unit that determines the adjacent auxiliary / master unit (second backbone unit).

  The slave unit adjacent to the terminal side of the master unit is connected to the master unit by a communication path based on one of the priority / master unit or auxiliary / master unit corresponding to the communication path selected in the master unit. Send and receive packets.

(2) Route switching process due to a communication disruption device When a slave unit becomes a communication disruption unit, the slave unit may execute processing for switching a communication path with reference to a subordinate table. This processing is to switch the communication path on the terminal side from the communication breaker based on the subordinate table provided in the communication breaker.

(A-1) The communication disruption device acquires the destination ID from the communication path information included in the data transmission packet that has not been processed at the transmission destination. Then, with reference to its own subordinate table, another communication path from the communication interruption device to the destination child device is searched based on the destination ID. At this time, it does not matter whether the communication path is a priority path or an auxiliary path. Further, when a plurality of communication paths are searched, the one with the smallest number of relays is searched.

  When the communication route from the communication disruption device to the destination child device is not searched, the communication disruption device sends an incommunicable packet to the parent device as described in “(1) Route switching processing by the parent device”. Transmitting and causing the base unit to execute processing for switching the communication path.

  On the other hand, when a new communication path from the communication interruption device to the destination child device is searched, the communication interruption device generates a new data transmission packet and executes the following processing. The communication disruption device changes the disabling / communication route information included in the data transmission packet that has not been processed at the transmission destination to the content indicating the searched new communication route. That is, the ID after the own ID in the disabled / communication path information is changed to the content indicating the new communication path. Then, the ID described next to its own ID in the changed communication path information is described in the transmission destination ID description part of the newly generated data transmission packet. In addition, information for controlling the transmission destination slave unit is described in the control information description part, and the changed communication path information is described in the communication path information description part. Then, the same data to be transmitted as the data transmission packet that has not been processed at the transmission destination is described in the data description section. The communication breaker transmits a newly generated data transmission packet.

  A case will be described in which a packet for data transmission is transmitted from the parent device P0 to the child device C3 through the relay of the child device C1, but the child device C3 is disconnected. The child device C3, which is a communication disruption device, acquires the destination ID from the communication path information included in the data transmission packet that has not been processed at the transmission destination. If this disabling / communication path information is (ID0, ID1, ID3, ID6, ID8), handset C3 acquires ID8 as the destination ID. The slave unit C3 refers to its own subordinate table and searches for a new communication path that reaches the destination slave unit C8.

  FIG. 7 (C3) shows a subordinate table of the child device C3. According to this, ID7 is associated with ID8 as the auxiliary / parent device ID, and ID3 is associated with ID7 as the priority / parent device ID. Accordingly, the child device C3 obtains, as a search result, a route to the child device C8 by relay of the child device C7 as a communication route to the destination child device C8.

  The subunit | mobile_unit C3 produces | generates a new data transmission packet. Then, the communication path information (ID0, ID1, ID3, ID6, ID8) is changed to new communication path information (ID0, ID1, ID3, ID7, ID8).

  The slave C3 describes ID7 described next to its own ID3 in the communication path information after the change in the transmission destination ID description part of the newly generated data transmission packet. In addition, information for controlling the transmission destination slave unit is described in the control information description part, and the changed communication path information is described in the communication path information description part. Then, the same data to be transmitted as the data transmission packet that has not been processed at the transmission destination is described in the data description section. The subunit | mobile_unit C3 transmits the packet for data transmission produced | generated newly.

  As a result, the communication path from the parent device P0 to the child device C8 is changed from the communication route from the parent device P0 to the child device C1, the child device C3, and the child device C6, and from the parent device P0 to the child device C1. The communication path to the child device C8 is switched by relay between the child device C3 and the child device C7. This switching is performed in the child device C3 which is a relay breaker.

  According to such processing, the relay breaker whose data transmission packet has not been processed in the subordinate slave unit changes the communication path and continuously transmits the data transmission packet to the destination slave unit. In this case, since the relay breaker does not need to transmit a packet that cannot be communicated to the master unit, the process of transmitting the data transmission packet to the destination slave unit is quickly performed. Furthermore, the number of packets transmitted by the slave unit closer to the master unit than the relay breaker is reduced. This avoids congestion in the multi-hop communication system.

(A-2) From the viewpoint of processing executed by the relay breaker, the route switching processing described here is described as follows.

Relay disruption machine medium, by acknowledge packet is not received, it recognizes that the communication condition at terminal side of the communication path is not good. Then, referring to the subordinate table, if a new communication path from the relay breaker to the destination slave unit is formed by switching the parent unit of any slave unit on the end side of the relay breaker, The parent side machine (core side machine) of the corresponding child machine on the side is switched, and the new communication path is selected. The relay breaker transmits the packet to the selected communication path.

That is, the relay breaker refers to a communication status recognition unit that recognizes the communication status in the communication path, and a subordinate table (route information) provided in the relay breaker based on the communication status in the communication path, so that a plurality of communication paths The slave unit control unit includes a selection unit that selects any one of the selection units.

  Further, from the viewpoint of processing executed by the slave unit on the terminal side of the communication disruption unit, the route switching processing described here is explained as follows.

As described above, the slave unit on the terminal side of the communication disruption unit is any one of the communication disruption unit and a plurality of other slave units (relay units) that form a communication path for the communication disruption unit on the communication path. Is determined as the priority / parent side machine (first trunk side machine) adjacent to the parent machine side, and further, the auxiliary / adjacent machine adjacent to the parent machine side on the communication path is determined as the priority / parent side machine. The slave unit control unit includes a determination unit that determines a master unit (second backbone unit).

  The slave unit at the end of the communication disruption unit is connected to the communication disruption unit by a communication path based on one of the priority / master unit or auxiliary / master unit corresponding to the communication path selected in the relay disruption unit. Send and receive packets.

  Note that the route switching processing by the communication disruption device is performed in an auxiliary manner to the route switching processing by the parent device. Therefore, it does not necessarily have to be executed in a multi-hop communication system. When the route switching process due to the communication disruption device is not executed, each slave device does not have to have a subordinate table.

  10 parent device control unit, 12 parent device transmission / reception unit, 14, 30 memory, 16 route information table, 18 parent device communication program, 20 interface, 22 computer, 24 measuring instrument, 26 child device control unit, 28 child device transmission / reception unit, 32 Subordinate table, 34 Slave device communication program, 36 Priority / master device ID, 38 Auxiliary / master device ID, P, P0 Master device, C, C1 to C8 slave devices.

Claims (8)

A basic radio that performs radio communication with a plurality of radios,
The plurality of radios form a plurality of tree-shaped communication paths in which the core radio is a starting node and each radio is a branch node or a terminal node,
The backbone radio is
As a key-side machine adjacent to the core radio side on a communication path, and the path information stored in the first radio and the second radio is associated individually for each radio,
A communication status recognition unit that recognizes the communication status in the communication path;
By referring to the path information based on the communication status in the communication path and individually selecting either the first radio or the second radio as the backbone machine for each radio, a plurality of types of communication A selector for selecting one of the routes;
It includes a packet transmission unit that transmits packets to the communication path formed by the base-side machine which is selected for each radio, and
The route information is
A backbone wireless device characterized in that it is information indicating a communication path by tracing the backbone side device selected for each wireless device. The backbone wireless device according to claim 1,
The communication status recognition unit
From the one that received the packet among the plurality of wireless devices, obtain communication incompatibility information that the packet cannot be transmitted to the end side of the communication path,
The selection unit includes:
When the communication status recognizing unit acquires the incommunicable information, it refers to the path information, switches the backbone side machine for the switching point radio adjacent to the terminal side of the radio that has received the packet, and switches the switching point. A basic wireless device, wherein a communication path indicated by tracing the basic device selected for each wireless device is selected from a wireless device to the basic wireless device. The backbone wireless device according to claim 1 ,
The communication status recognition unit
Determine whether it is possible to send a packet to a radio adjacent to the terminal radio side,
The selection unit includes:
When it is determined that it is not possible to transmit the packet is refers to the route information, switches the base-side unit that is selected for switching point radio adjacent the distal side of the trunk radio, the A trunk radio that selects a communication path indicated by tracing the trunk side machine selected for each radio from a switching point radio to the trunk radio. The backbone radio device according to any one of claims 1 to 3 ,
The plurality of radios;
A multi-hop wireless communication system comprising: A wireless device constituting one of a plurality of wireless devices that perform wireless communication with a backbone wireless device,
The plurality of radios form a plurality of tree-shaped communication paths in which the core radio is a starting node and each radio is a branch node or a terminal node,
Each radio is
Subordinate route information in which the first wireless device and the second wireless device are individually associated with each wireless device on the terminal side as a basic device adjacent to the basic wireless device side on the communication route;
A communication status recognition unit that recognizes the communication status in the communication path;
By referring to the subordinate route information based on the communication status in the communication route, and selecting each of the first wireless device and the second wireless device as the backbone device individually for each wireless device, a plurality of ways A selection unit for selecting one of the communication paths;
A packet transmission unit that transmits a packet to a communication path formed by the backbone side machine selected for each wireless device,
The subordinate route information is
A radio apparatus characterized in that a communication path is indicated by tracing the backbone side machine selected for each radio machine. The wireless device according to claim 5,
The communication status recognition unit included in the wireless device is
Determining whether it is possible to send a packet to a radio adjacent to the terminal side of the radio device;
The selection unit included in the wireless device includes:
It is determined that it is not possible to transmit a packet, and by switching the backbone side device selected for any one of the wireless devices on the end side of the wireless device, a new communication from the wireless device to the destination wireless device is performed. When a new communication path is formed, the radio apparatus is characterized by switching the backbone side machine selected for the terminal side radio apparatus and selecting the new communication path. A communication program that is read into a core wireless device that performs wireless communication with a plurality of wireless devices,
The plurality of radios form a plurality of tree-shaped communication paths in which the core radio is a starting node and each radio is a branch node or a terminal node,
The backbone radios as base-side machine adjacent to the core radio side on a communication path, have the route information stored in the first radio and the second radio is associated individually for each radio And
The communication program is
Processing for recognizing the communication status in the communication path;
By referring to the path information based on the communication status in the communication path and individually selecting either the first radio or the second radio as the backbone machine for each radio, a plurality of types of communication Processing to select one of the routes,
Causing the backbone wireless device to execute a process of transmitting a packet to a communication path formed by the backbone side device selected for each wireless device ;
The route information is
A communication program characterized in that it is information indicating a communication path by tracing the backbone side machine selected for each radio . A communication program that is read into a wireless device that constitutes one of a plurality of wireless devices that perform wireless communication with a backbone wireless device ,
The plurality of radios form a plurality of tree-shaped communication paths in which the core radio is a starting node and each radio is a branch node or a terminal node,
Each radio is
As the backbone side devices adjacent to the backbone wireless device side on the communication route, the first wireless device and the second wireless device have subordinate route information individually associated with each wireless device on the terminal side. And
The communication program is
Processing for recognizing the communication status in the communication path ;
By referring to the subordinate route information based on the communication status in the communication route, and selecting each of the first wireless device and the second wireless device as the backbone device individually for each wireless device, a plurality of ways A process for selecting one of the communication paths;
A process of transmitting a packet to a communication path formed by the backbone side machine selected for each wireless device, causing the wireless device to execute,
The subordinate route information is
A communication program characterized in that it is information indicating a communication path by tracing the backbone side machine selected for each radio.

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