TW201739285A - Wireless communication apparatus and wireless communication method - Google Patents

Abstract

A wireless communication apparatus comprises: a wireless communication control unit that outputs a message upon receipt via another wireless communication apparatus of a wireless signal addressed to the wireless communication apparatus and including a message related to path control; and a network control unit that, if the message input from the wireless communication control unit is a path setting request designating an adjacent wireless communication apparatus that is passed through as an upstream path leading to a gateway, transmits, on the upstream path satisfying the designation of the path setting request, a downstream path control message including the address information of the wireless communication apparatus. Accordingly, a path can be fixed using RPL.

Description

Wireless communication device and wireless communication method

The present invention relates to a wireless communication device and to techniques for updating path information in a network formed by a plurality of wireless communication devices.

The wireless M2M (Machine-to-Machine) system is widely used in the expansion of the unlicensed frequency band accompanying the cost reduction or frequency reprogramming of the wireless module. A wireless M2M system is a system that transmits and receives monitoring information or control data between machines by wireless communication. In the wireless M2M system, in order to communicate with devices arranged in a wide area, the elongation of the communication distance is cited as one of the subjects.

In the technique of extending the communication distance, a relay node is disposed between the source node and the destination node, and the relay node receives the data transmitted by the source node, and the relay node receives the data. The multi-hop communication technology for the destination node to transmit. By applying multi-hop communication technology, the communication distance between the source node and the destination node can be extended without extending the communication distance of the wireless link. One of the multi-hop communication technologies is RPL (IPv6 Routing Protocol for Low Power and Lossy Networks) standardized by the IETF (see Non-Patent Document 1 below).

In wireless communication, since the radio wave condition changes from time to time, periodic updating of the path for communication is indispensable. In the RPL, for the update of the path, the node and the gateway periodically transmit the path information. Each node is constructed with The gateway is a tree-like multi-hop network at the root. The node determines the upstream path from the node toward the gateway based on the path information periodically transmitted by the gateway. In addition, the node determines the downlink path from the gateway toward the other nodes based on the path information periodically transmitted by other nodes.

The update of the uplink path and the downlink path in the RPL is illustrated using pictures 19-21.

Fig. 19 is a diagram showing an example of a network configuration. A gateway 91 and nodes 92a-c are present in the network 90. The node 92a is adjacent to the node 92b and is a higher node of the node 92b and the node 92c. Node 92b is adjacent node 92c and is the upper node of node 92c.

First, the update of the uplink path will be described.

Figure 20 is a diagram showing the sequence of updating the upstream path.

The gateway sets the uplink path information as an uplink path control message and periodically transmits it by broadcast (S801). The node 92a that receives the uplink path control message from the gateway updates the uplink path information to the gateway (S802). The node 92a sets the updated uplink path information as an uplink path control message and transmits it by broadcast (S803). The node 92b receives the uplink path control message from the node 92a and updates the uplink path information to the gateway (S804). The node 92b sets the updated uplink path information as an uplink path control message and transmits it by broadcast (S805). The node 92c receives the uplink path control message from the node 92b and updates the uplink path information to the gateway (S806). The node 92c sets the updated uplink path information as an uplink path control message and transmits it by broadcast (S807).

Next, the update of the downlink path will be described.

Figure 21 is a diagram showing the sequence of updating the downstream path. Node 92a~c The downlink path control message is periodically transmitted to the adjacent upper node in unicast.

The node 92c unicasts the downlink path control message to the adjacent upper node, that is, the node 92b (S901). The node 92b that has received the downlink path control message updates the downlink path information to the node 92c (S902). Further, the node 92b transmits the downlink path control message for which the updated downlink route information has been set to the adjacent upper node, that is, the node 92a (S903). The node 92a that has received the downlink path control message updates the downlink path information to the node 92c (S904). Further, the node 92a transmits a downlink path control message for which the updated downlink route information has been set to the gateway (S905). The gateway receiving the downlink path control message updates the downlink path information to the node 92c (S906).

[Previous Technical Literature]

[Non-patent literature]

Non-Patent Document 1: IETF RFC6550, "IPv6 Routing Protocol for Low-Power and Lossy Networks"

However, in RPL, there is a problem that the path is dynamically updated and the path cannot be fixed.

The present invention has been made to solve the above problems, and aims to obtain a wireless communication device in which a path is fixed if RPL is used.

The wireless communication device of the present invention includes: a wireless communication control unit that outputs a message when receiving a wireless signal from the wireless communication device including a message related to the path control through another wireless communication device; The road control unit is configured to indicate a path setting request from the adjacent wireless communication device via the wireless communication device as the information input by the wireless communication control unit, and include the downlink information including the address information from the wireless communication device. The path control message is transmitted on an uplink path that satisfies the indication of the path setting requirement.

With the present invention, the RPL can be used to make the path fixed.

10, 90‧‧‧ Network

11, 91‧‧ ‧ gateway

12a~e‧‧‧ nodes

92a~c‧‧‧ nodes

13a~e‧‧‧ links

21‧‧‧Applications Department

22‧‧‧Network Control Department

23‧‧‧Path Maintenance Department

24‧‧‧Wireless Communications Control Department

25‧‧‧Network Interface Control Department

26‧‧‧Sensor Interface Control Department

27‧‧‧ Sensors

28‧‧‧Path Maintenance Timer

30‧‧‧Wireless antenna

31‧‧‧ memory

32‧‧‧ processor

33‧‧‧sensor interface

34‧‧‧Network interface

35‧‧‧Wireless interface

36‧‧‧Timer

Fig. 1 is a view showing an example of the configuration of the network of the first embodiment.

Fig. 2 is a block diagram showing an example of a functional configuration of a node in the first embodiment.

Fig. 3 is a block diagram showing an example of a hardware configuration of a node in the first embodiment.

Fig. 4 is a view showing an example of a format of a path setting request in the first embodiment.

Fig. 5 is a flow chart showing the processing of the network control unit of the first embodiment.

Fig. 6 is a flow chart showing the processing of the network control unit of the first embodiment.

Fig. 7 is a schematic view showing the operation of setting a fixed path at a node in the gateway of the first embodiment.

Fig. 8 is a view showing an example of a list of fixed paths held by the path storage unit in the first embodiment.

Fig. 9 is a schematic diagram showing the operation of the node of the first embodiment to receive DIO by the node.

Fig. 10 is a schematic view showing the operation of the gateway in the first embodiment in the node setting exclusion route.

Fig. 11 is a view showing an example of a list of excluded routes held by the path storage unit in the first embodiment.

Fig. 12 is a schematic diagram showing the operation of the node of the first embodiment to receive DIO by the node.

Fig. 13 is a schematic diagram showing the operation of the node of the first embodiment to receive DIO by the node.

Fig. 14 is a flow chart showing the processing of the network control unit of the first embodiment.

Fig. 15 is a block diagram showing an example of a functional configuration of a node in the second embodiment.

Fig. 16 is a block diagram showing an example of a hardware configuration of a node in the second embodiment.

Fig. 17 is a flow chart showing the processing of the network control unit of the second embodiment.

Fig. 18 is a flow chart showing the processing of the network control unit of the second embodiment.

Fig. 19 is a diagram showing an example of a network configuration.

Figure 20 is a sequence diagram showing the process of updating the uplink path.

Figure 21 is a sequence diagram showing the process of updating the downstream path.

Embodiment 1.

First, the network configuration of the present invention will be described.

Fig. 1 is a view showing an example of the configuration of the network 10 of the first embodiment. The network 10 is a network of gateways 11 and nodes 12a-d which are wireless communication devices. Further, the network 10 is a tree-structured network having the gateway 11 as a root. Gateway 11 constructs a network and transmits and receives data directly or through nodes. In addition, the gateway 11 transmits and receives data to and from a device or other network connected to the gate 11.

The direction from the node toward the gateway 11 is upward, and the gate 11 is facing The direction to the node is down. The node 12a and the node 12b are the lower nodes of the gateway 11, and the path to the gateway 11 has been established. The node 12c exists in a distance that can communicate wirelessly with the node 12a and the node 12b, but the state of the path has not yet been established. The node 12d is a lower node of the node 12c, and establishes a path with the node 12c. Chains 13a~e are links between nodes. The solid line in Fig. 1 indicates that the path has been established. The dotted line in Fig. 1 indicates that the path has not been established. The path is established, for example, if the path is the gateway 11 and the node 12a, the gateway 11 maintains the downlink path information to the node 12a, and the node 12a maintains the state of the uplink path information to the gateway 11.

Next, the configuration of the node 12a as the wireless communication device of the present invention will be described. The configuration of the nodes 12b to d is the same as that of the node 12a.

Fig. 2 is a block diagram showing an example of the functional configuration of the node 12a of the first embodiment. The node 12a includes an application unit 21, a network control unit 22, a path storage unit 23, a wireless communication control unit 24, a network interface control unit 25, and a sensor interface control unit 26. The wireless antenna 30 is connected to the wireless communication control unit 24. The network interface control unit 25 transmits and receives data to and from other networks connected to the node 12a. The information also has information to control the information. Further, a sensor 27 is connected to the sensor interface control unit 26.

Fig. 3 is a block diagram showing an example of the hardware configuration of the node 12a of the first embodiment. The node 12a includes a memory 31, a processor 32, a sensor interface 33, a network interface 34, and a wireless interface 35. The processor 32 is connected to the memory 31 to perform temporary memory or data storage of data required for calculation. In addition, the processor 32 is connected to the sensor interface 33, the network interface 34, and the wireless interface 35, and the control of each interface is performed by an instruction from the processor 32. In addition, The wireless interface 35 is connected to the wireless antenna 30 to transmit and receive wireless signals.

The memory 31 stores programs and materials for realizing the functions of the application unit 21, the network control unit 22, the wireless communication control unit 24, the network interface control unit 25, and the sensor interface control unit 26. Further, the memory 31 stores data for realizing the function of the path storage unit 23. The memory system is, for example, a ROM (Read Only Memory), a RAM (Random Access Memory), an HDD (Hard Disk Drive), and an SSD (Solid State Drive). The machine is composed of.

The processor 32 reads out programs and data stored in the memory 31, and realizes functions of the application unit 21, the network control unit 22, and the wireless communication control unit 24. The processor 32 is realized by executing a processing circuit such as a CPU or a system LSI (Large Scale Integration) that stores the program stored in the memory 31.

However, the complex processing circuit may be combined to execute the functions of the application unit 21, the network control unit 22, and the wireless communication control unit 24.

The sensor interface 33 implements the function of the sensor interface control unit 26.

The network interface 34 implements the functions of the network interface control unit 25.

Next, transmission and reception of wireless signals with other nodes will be described.

First, a case where a wireless signal is received by another node will be described.

The wireless antenna 30 receives the wireless signal transmitted by the other node and outputs it to the wireless communication control unit 24. The wireless communication control unit 24 converts the wireless signal input by the wireless antenna 30 into a frame and confirms the receiving destination of the frame. Two MAC addresses and network addresses are set at the destination of the receiving. The MAC address indicates the destination of the next node on the path. Network address frame The receiving end of the receiving office.

When the receiving destination of the frame and the MAC address of the own node are the same, the wireless communication control unit 24 outputs the signal to the network control unit 22, and if it is different from its own MAC address, the frame is revoked. The network control unit 22 confirms the network address of the receiving destination of the frame input by the wireless communication control unit 24. If the network address of the destination of the reception is different from the network address of the self node, the network control unit 22 refers to the path list of the path storage unit 23, and the path of the node having the network address of the destination of the destination. The information is read from the MAC address of the node to be transferred, and the network control unit 22 outputs the read MAC address and frame to the wireless communication control unit 24.

If the network address is the same as the network address of the self node, and the data portion of the frame contains the application data, the network control unit 22 outputs the data portion of the frame input by the wireless communication control unit 24. Go to the application section 21. The application unit 21 outputs the data to the network interface control unit 25 or the sensor interface control unit 26 in accordance with the content of the data. The application unit 21 outputs control information to the network interface control unit 25 if the data includes control information of the network connected to the network interface control unit 25. Further, if the data includes the control information of the sensor 27, the application unit 21 outputs control information to the sensor interface control unit 26.

If the network address of the frame input by the wireless communication control unit 24 is the same as the network address of the self node, and the data portion of the frame contains the path control message, the network control unit 22 controls the path according to the path. The content of the message is updated by the path list held by the path storage unit 23.

Next, a case where a wireless signal is transmitted to other nodes will be described.

If the data is input by the network interface control unit 25, the application unit 21 is paired. The network control unit 22 outputs the data. Further, when the measured value is input from the sensor 27, the sensor interface control unit 26 performs processing for converting the data into a predetermined format, and outputs the data to the application unit 21. The application unit 21 outputs the data input by the network interface control unit 25 or the sensor interface control unit 26 and the network address of the destination of the reception to the network control unit 22. The network control unit 22 sets the data input by the application unit 21 to the data portion of the frame, and sets the network address of the destination of the message to the header of the frame. Further, the network control unit 22 inquires of the path storage unit 23 about the MAC address of the node to be transferred next. The network control unit 22 outputs the MAC address and frame acquired by the path storage unit 23 to the wireless communication control unit 24. The wireless communication control unit 24 sets the MAC address input by the network control unit 22 to the header of the frame. Further, the wireless communication control unit 24 converts the frame into a wireless signal and outputs the wireless signal to the wireless antenna 30.

Further, the network control unit 22 generates a path control message by the path information held by the path storage unit 23, and sets the path control message in the data portion of the frame. Further, the network control unit 22 inquires of the path storage unit 23 about the MAC address of the node to be transferred, and outputs the acquired MAC address and frame to the wireless communication control unit 24. The network control unit 22 outputs the frame to the wireless communication control unit 24, and the wireless communication control unit 24 transmits the data to the other node via the wireless antenna 30.

In the RPL, DIO (Direction-Oriented Directed Acyclic Graph Information Object) is used in the control of the uplink path. The DAO (Destination Advertisement Object) is used in the control of the downlink path.

Each node can grasp the gateway 11 by DIO and DAO. The path to other nodes. The path list of the path storage unit 23 of each node holds path information for the gateway 11 and other nodes. The address of the receiving destination device, the address of the next node, the ranking information, and the valid period are saved as the path information of the gateway 11 and other nodes. The address of the next node is the address of the adjacent node on the path to the receiving destination device. The ranking information is a value calculated from the number of jumps up to the gateway 11 and the radio wave reception strength. The lower ranking information is suitable as a path in terms of the number of jumps and the state of the radio wave. The node determines the path by selecting the node with the lowest ranking information. The valid period is the valid period of the path information. The path information that has passed the valid period is abolished. The path list maintains the uplink path information for the gateway 11 and the downlink path information for the lower node.

The network control unit 22 maintains the address, ranking information, and valid period of the self node. The valid period is a value that is pre-specified as a parameter for the valid period of the path information.

Next, an operation when the uplink path is instructed by the path setting request will be described.

First, the format of the path setting requirement will be explained.

Fig. 4 is a view showing an example of a format of a path setting request in the first embodiment. The path setting requirement is composed of a message category field, a path setting field, a path number field, and a path field. In the message category, an identification code indicating the path setting request is set. In the path setting field, the fixed path is set to be valid, and the excluded path is valid or invalid. The fixed path is effective to indicate that the path indicated by the path field is set as a fixed path. The exclusion path is valid to indicate that the path indicated by the path field is set as the exclusion path. Invalid means that the fixed path and the excluded path that have been set are invalidated. The path number field is set in the path set by the path field. The number of paths. In the path field, the network address of the node to be set is set as the path to be set. If N is set in the path number field, N paths are set in the path field.

Next, a case where the node 12c receives the path setting request will be described as an example.

Fig. 5 is a flowchart showing the processing of the network control unit 22 of the first embodiment. The network control unit 22 of the node 12c starts processing when the transmission node 12a receives the path setting request from the gateway 11. The network control unit 22 determines the value of the path setting required for the path setting (step S301). When the path setting is set to be a fixed path, the network control unit 22 performs a process of validating the fixed path of the node 12c (step S302). The network control unit 22 registers the path displayed by the path field in the fixed path list as a process of validating the fixed path, and ends the process. The fixed path list is held by the path storage unit 23 (step S303).

In step S301, if the route setting is set to the exclusion route, the network control unit 22 performs a process of validating the exclusion route of the node 12c (step S304). The network control unit 22 registers the path indicated by the path field in the exclusion route list, and ends the process as a process of validating the exclusion route. The exclusion route list is held by the route storage unit 23 (step S305). In step S301, if the route setting is set to be invalid, the network control unit 22 performs a process of invalidating the fixed route list and the excluded route list held by the route storage unit 23 (step S306). The network control unit 22 initializes the fixed route list and the excluded route list held by the route storage unit 23 as a process of invalidating the fixed route list and the excluded route list (step S307), and ends the process.

Next, the operation of the node 12c to set the uplink path will be described.

Fig. 6 is a flowchart showing the processing of the network control unit 22 of the first embodiment. The network control unit 22 of the node 12c starts processing when the node 12a receives the DIO. The network control unit 22 determines the current path setting (step S401). If the fixed path and the excluded path are set to be invalid, the network control unit 22 selects the uplink path based on the path information notified by the received DIO. The network control unit 22 determines the uplink path in accordance with the standard communication protocol of the RPL. For example, there is a method of selecting by the shortest number of relays and a method of selecting according to the strength of the received electric field strength. The network control unit 22 sets the upper node that is adjacent to the uplink path to the next node address of the uplink path information (step S402). Next, the network control unit 22 transmits a downlink path control message, that is, DAO, to the higher node that determines the uplink path. When the node 12a is selected as the uplink path, the network control unit 22 transmits the DAO to the node 12a. As described above, the upper node sets the downlink path information to the node 12c by receiving the DAO (step S403).

On the other hand, in step S401, if the fixed path is set to be valid, the network control unit 22 determines whether or not the received source network address (node 12a) of the DIO is registered in the fixed path list (step S404). If the DIO's source network address (node 12a) is registered in the fixed path list, the network control unit 22 sets the node 12a at the next node address of the uplink information of the gateway 11 (step S402). The DAO is transmitted to the node 12a (step S403). If the DIO's source network address (node 12a) is not registered in the fixed path list, the network control unit 22 abolishes the received DIO because it is not a DIO that is notified by the fixed path. The network control unit 22 does not set the uplink path here, nor does it transmit the DAO (step S405).

Further, in step S401, if it is set that the exclusion route is valid, the network control unit 22 determines whether or not the received source network address (node 12a) of the DIO is registered in the exclusion route list (step S406). . If the received source network address (node 12a) of the DIO is registered in the exclusion path list, the network control unit 22 abolishes the received DIO because it is the DIO notified by the exclusion path. The network control unit 22 does not set the uplink path and does not transmit the DAO (step S405). If the received source network address (node 12a) of the DIO is not registered in the exclusion path list, the network control unit 22 sets the node 12a at the next node address of the uplink path information of the gateway 11. (Step S402), the DAO is transmitted to the node 12a (step S403).

Next, the operation of setting the fixed path will be described using a specific example.

Fig. 7 is a schematic view showing an operation of setting a fixed path at the node 12c by the gateway 11 of the first embodiment.

When the gateway 11 transmits the path setting request for setting the link 13c to the fixed path to the node 12c, the fixed path is set in the path setting field, the path number field is set to 1, and the path field setting node 12a is set. Network address.

Fig. 8 is a view showing an example of a list of fixed paths held by the path storage unit 23 of the first embodiment. If the link 13c is set to a fixed path, the fixed path list at the node 12c sets the network address of the node 12a as shown in FIG.

Fig. 9 is a schematic diagram showing the operation of the node 12c of the first embodiment to receive DIO by the nodes 12a and 12b. When the fixed path list of the node 12c is registered to the node 12a, the node 12c receives the DIO from the node 12a registered in the fixed path list, and selects the node 12a as the uplink path, and transmits the DAO to the node 12a. In addition, the node 12c is a node that is not registered in the fixed path list. 12b receives the DIO and abolishes the received DIO. Therefore, the node 12c sets the uplink path via the node 12a that is set as the fixed path.

Next, the operation of setting the exclusion route will be described using a specific example.

Fig. 10 is a schematic view showing the operation of setting the exclusion path at the node 12c by the gateway 11 of the first embodiment.

When the gateway 11 transmits the route setting request for setting the link 13d to the exclusion route to the node 12c, the route setting field is set to be valid in the path setting field, the path number field is set to 1, and the path field setting node 12b is set. Network address.

Fig. 11 is a view showing an example of a list of excluded routes held by the path storage unit 23 of the first embodiment. If the exclusion path setting link 13d is used, the exclusion path list at the node 12c sets the network address of the node 12b as shown in FIG.

Fig. 12 is a schematic diagram showing the operation of the node 12c of the first embodiment to receive DIO by the nodes 12a and 12b. If the node 12b is registered in the exclusion route list of the node 12c, the node 12c receives the DIO from the node 12a that is not registered in the exclusion route list, and the selection node 12a transmits the DAO to the node 12a as the uplink path. Further, if the node 12c receives the DIO from the node 12b registered in the exclusion route list, the DIO to be received is revoked. Therefore, the node 12c sets an uplink path via a node other than the node 12b that is set as the exclusion path.

Next, the operation of changing the fixed path will be described.

Fig. 13 is a schematic view showing an operation of changing the fixed path by the node 12c of the first embodiment.

Fig. 14 is a flowchart showing the processing of the network control unit 22 of the first embodiment. The node 12c is formed to set the node 12a designated as a fixed path. The state of the next node address of the uplink path information to the gateway 11. At this time, the network control unit 22 of the node 12c starts the process by receiving the path setting request of the setting node 12b as a fixed path. The network control unit 22 of the node 12c refers to the fixed path list and determines whether or not there is a node registered in the fixed path list (step S501). If there is a node registered in the fixed route list, the network control unit 22 of the node 12c deletes the originally registered node 12a from the fixed route list (step S502). Further, the network control unit 22 of the node 12c registers the node 12b notified of the route setting request in the fixed route list (step S503).

The network control unit 22 of the node 12c determines whether or not the originally registered node 12a is set as the uplink path (step S504). When the node 12a is set to the next node address of the uplink path information to the gateway 11, the network control unit 22 of the node 12c transmits the DAO set to Lifetime=0 to the node 12a. When the node 12a that has received the DAO of the Lifetime=0 is set to retain the downlink route information of the node 12c, the downlink path information of the node 12c is deleted (step S505). The network control unit 22 of the node 12c transmits the DAO to the node 12b notified of the path setting request (step S506). Further, the network control unit 22 of the node 12c sets the node 12b notified of the route setting request to the next node address of the uplink route information to the gateway 11 (step S507), and ends the process.

However, in step S501, if there is no node registered in the fixed path list, the processing proceeds to step S506. Further, in step S504, if the node 12a is not set as the uplink path, the processing proceeds to step S506.

Further, in the present embodiment, the route list is described as maintaining the uplink route information to the gateway 11, but may also be maintained via the gate switch. The path information of other upper nodes other than the node of the next node address of the uplink path information of the track 11. In addition, the uplink path information to the upper node can also be maintained.

As described above, in the present embodiment, the wireless communication control unit 24 that outputs a message when the other node receives the message from the node to the path control is included; and the message input by the wireless communication control unit is When the route setting request of the first adjacent node passing through the uplink path of the gateway is instructed, the network control unit 22 that transmits the downlink path control message including the address information of the node is transmitted on the uplink path that satisfies the instruction of the path setting request. Therefore, RPL can be used to fix the path.

Further, when the path setting request is instructed to pass the uplink path of the first adjacent node and the uplink path control message received by the first adjacent node is input, the network control unit 22 outputs the first adjacent node as the first adjacent node. Since the downlink path control message of the destination end is received, the path to the first adjacent node indicated as the fixed path can be established.

Further, when the network control unit 22 is instructed to pass the uplink path of the first adjacent node by the path setting request and the uplink path control message received by the second adjacent node is input, the second control is not output. Since the node serves as the downlink path control message of the destination of the reception, the path of the second adjacent node other than the fixed path may not be established.

Further, when the network control unit 22 is instructed to pass the uplink path of the first adjacent node by the path setting request, the network control unit 22 is instructed to output the uplink path via the second adjacent node by the new path setting request. A downlink path control message in which the adjacent node is the destination of the reception and the downlink path to the own node is invalid, and the radio communication control unit 24 is to be input by the network control unit. The line path control message is transmitted to the first adjacent node, so the fixed path can be changed.

Further, when the path setting request is instructed to exclude the third adjacent node from the path, and the uplink path control message received by the fourth neighboring node is input, the network control unit 22 outputs the fourth adjacency Since the node serves as the downlink path control message of the destination of the reception, it is possible to establish a path to the fourth adjacent node other than the excluded path.

Further, when the path setting request is instructed to exclude the third adjacent node from the path, and the uplink path control message received by the third adjacent node is input, the network control unit 22 does not output the third path. Since the adjacent node serves as the downlink path control message of the destination of the reception, the path to the third adjacent node indicated as the exclusion path may not be established.

Further, the network control unit 22 is instructed to invalidate the path excluding the third adjacent node by the new path setting request after the uplink path excluding the third adjacent node is instructed by the path setting request. In the case of the purpose, the uplink path information including the address information of the third adjacent node is deleted from the exclusion path list, so the exclusion path can be changed.

Embodiment 2.

In the first embodiment, the route is fixed by the route setting request. However, in the present embodiment, the embodiment shows a case where a communication failure occurs in the fixed route.

In the present embodiment, a portion different from the first embodiment will be described.

Fig. 15 is a block diagram showing an example of the functional configuration of the node 12a of the second embodiment. The difference from the functional configuration of the node 12a of the first embodiment is the addition of the path maintenance timer 28.

Fig. 16 is a block diagram showing an example of the hardware configuration of the node 12a of the second embodiment. The difference from the hardware configuration of the node 12a of the first embodiment is that the timer 36 is added. The timer 36 implements the function of the path maintenance timer 28.

First, a method of detecting a communication failure will be described.

Fig. 17 is a flow chart showing the processing of the network control unit 22 of the second embodiment. The network control unit 22 of the node 12c starts the process by receiving the path setting request message that the node 12a is a fixed path. The network control unit 22 of the node 12c activates the path maintenance timer 28 (step S601). The network control unit 22 of the node 12c waits to receive DIO from the node 12a set in the fixed path (step S602). The network control unit 22 of the node 12c determines whether or not the DIO is received by the node 12a set in the fixed path (step S603). If the DIO is received by the node 12a, the path maintenance timer 28 is reset (step S604). If the DIO is not received by the node 12a, the processing proceeds to step S603.

Next, the operation of resetting the path when the path maintenance timer 28 has expired will be described.

Fig. 18 is a flow chart showing the processing of the network control unit 22 of the second embodiment. If the path maintenance timer 28 has expired, the network control unit 22 of the node 12c starts processing. When the path maintenance timer 28 has expired, the network control unit 22 of the node 12c determines that a communication failure has occurred in the fixed path (node 12a) (step S701). If it is determined that the communication is a failure, the network control unit 22 of the node 12c collects the path information of the path other than the fixed path. The collected path information is information required for path selection such as the number of times of the route or the strength of the received electric field (step S702). The network control unit 22 of the node 12c is configured to make a communication failure notification. The communication failure notification system contains communication failures and collected path information. (Step S703).

The network control unit 22 of the node 12c notifies the gateway 11 of the communication failure notification, and thus sets a temporary path. At this time, the network control unit 22 selects the adjacent upper node through which the uplink path passes, based on the collected path information. Here, it is assumed that the node 12b is selected as the upper node (step S704). The network control unit 22 of the node 12c transmits a communication failure notification to the gateway 11 via the node 12b, and ends the processing (step S705).

The gateway 11 transmits a path setting request to the node 12c based on the communication failure notification received by the node 12c. The node 12c resets the path by receiving the path setting request from the gateway 11. The path setting request transmitted by the gateway 11 may be, for example, the node 12a being set to the exclusion path, or the node 12b being set to the fixed path.

In the present embodiment, the network control unit 22 sets a temporary uplink path from the collected route information. However, if the route list holds the uplink route information of a node other than the route determined to have a communication failure, The maintained uplink path information can also be utilized as a temporary path.

As described above, in the present embodiment, after receiving the route setting request for the uplink route via the first adjacent node, the network control unit 22 does not receive the uplink path control by the first adjacent node even after a predetermined time elapses. In the case of a message, a communication failure notification notifying the communication failure of the first adjacent node is transmitted to the gateway through the other adjacent nodes, so that it is monitored whether or not a communication failure occurs in the fixed path, and the gateway 11 can grasp that the communication failure occurs in the fixed path. If the gateway 11 is aware of a communication failure on a fixed path, a new fixed path can be set.

12a‧‧‧Wireless communication device

21‧‧‧Applications Department

22‧‧‧Network Control Department

23‧‧‧Path Maintenance Department

24‧‧‧Wireless Communications Control Department

25‧‧‧Network Interface Control Department

26‧‧‧Sensor Interface Control Department

27‧‧‧ Sensors

30‧‧‧Wireless antenna

Claims (12)

A wireless communication device, comprising: a wireless communication control unit that outputs a message when receiving a wireless signal from a wireless communication device including a message related to path control through another wireless communication device; The path control unit is configured to: if the message input by the wireless communication control unit is a path setting request indicating an adjacent wireless communication device that is an uplink path to the gateway, the address information including the wireless communication device is included The downlink path control message is transmitted on an uplink path that satisfies the indication of the path setting requirement described above. The wireless communication device according to claim 1, wherein the network control unit inputs the first neighbor when the uplink route of the first adjacent wireless communication device is instructed by the path setting request The uplink path control message received by the wireless communication device outputs the downlink path control message indicating the first adjacent wireless communication device as the destination of the reception, and the wireless communication control unit inputs the aforementioned information from the network control unit. The downlink path control message is transmitted to the first adjacent wireless communication device. The wireless communication device according to claim 2, wherein the network control unit is instructed to pass through an uplink path of the first adjacent wireless communication device by the path setting request, and is input by the second adjacent When the uplink control message is received by the wireless communication device, the downlink path control message in which the second adjacent wireless communication device is used as the destination of the reception is not output. The wireless communication device of claim 2, wherein the wireless communication device includes a path storage unit that maintains path information about an uplink path, and the network control unit is instructed via the path setting request via the first In the uplink path of the adjacent radio communication device, the uplink path information including the address information of the first adjacent radio communication device is registered in the fixed path list of the path storage unit. The wireless communication device according to claim 4, wherein the network control unit uses the new path after the uplink path of the first adjacent wireless communication device is instructed by the path setting request When the setting request is instructed to invalidate the uplink path via the first adjacent radio communication device, the uplink path information including the address information of the first adjacent radio communication device is deleted from the fixed path list. The wireless communication device according to any one of claims 2 to 5, wherein, after the network control unit is instructed to pass the uplink path of the first adjacent wireless communication device by the path setting request, When the new path setting request is instructed to pass the uplink path of the second adjacent wireless communication device, the first adjacent wireless communication device is output as the destination of the reception, and the downlink path to the wireless communication device is invalid. In the downlink path control message, the radio communication control unit transmits the downlink path control message input by the network control unit to the first adjacent radio communication device. The wireless communication device according to any one of claims 2 to 6, wherein the network control unit receives the path setting request indicating an uplink path of the first adjacent wireless communication device, even if When the uplink control message is not received by the first adjacent wireless communication device, the communication failure of the first adjacent wireless communication device is transmitted to the gateway through another adjacent wireless communication device. Communication failure notification. The wireless communication device according to any one of claims 1 to 7, wherein the network control unit is instructed to cause an uplink path excluding the third adjacent wireless communication device by the path setting request, and is When the uplink path control message received by the fourth adjacent wireless communication device is input, the downlink path control message indicating the fourth adjacent wireless communication device as the destination of the reception is output, and the wireless communication control unit is configured by the network. The downlink path control message input by the control unit is transmitted to the fourth adjacent wireless communication device. The wireless communication device according to claim 8, wherein the network control unit is configured to instruct an uplink path excluding the third adjacent wireless communication device by the path setting request, and is input to the third When the uplink control message is received by the adjacent wireless communication device, the downlink path control message that uses the third adjacent wireless communication device as the destination of the reception is not output. The wireless communication device according to claim 8 or 9, wherein the wireless communication device includes a path storage unit that maintains path information about the uplink path, and the network control unit is instructed to indicate the third item by the path setting request. When the uplink path is excluded from the adjacent radio communication device, the uplink path information including the address information of the third adjacent radio communication device is registered in the exclusion path list of the path storage unit. The wireless communication device according to claim 10, wherein the network control unit is configured by the new route except that the third adjacent wireless communication device is excluded by the path setting request When the route setting request is instructed to invalidate the route excluding the third adjacent wireless communication device, the uplink route information including the address information of the third adjacent wireless communication device is deleted from the excluded route list. A wireless communication method comprising: a wireless communication control step of outputting the foregoing message when receiving a wireless signal from a wireless communication device including a message related to path control through another wireless communication device; and a network control step If the message input by the wireless communication control step is a path setting request indicating an adjacent wireless communication device as an uplink path to the gateway, the downlink path including the address information from the wireless communication device is included. The control message is transmitted on an uplink path that satisfies the indication of the path setting requirement described above.