JP2010219801A - Communication system and node management method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a communication system that properly executes load distribution of each device which stores a terminal constituting a mesh network. <P>SOLUTION: The communication system is configured such that nodes and data collection devices constitute a mesh network. A control device holds a node, connectable to a data collection device, as network constituting information on the basis of adjacent node information received from the node. When a data collection device exceeds its load threshold, the control device selects a node managed by the data collection device, and connectable to a data collection device other than the data collection device, on the basis of the network constituting information, and further, selects a data collection device connectable to the node, and instructs the selected data collection device to manage the node (S22). The data collection device sets the node as its own management target on the basis of the instruction (S26). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a communication system and a node management method for managing nodes constituting a mesh network.

  A system for collecting data using a mesh network in which wireless terminals communicate with each other has been proposed (see, for example, Patent Document 1 below). When collecting data from each terminal in a large-scale mesh network, it is assumed that a plurality of collection devices that collect data are prepared and collected. In many conventionally proposed routing protocols, a route is determined based on the number of hops from the collection device to the terminal. For this reason, in a large-scale mesh network, the collection devices constituting the network are realized by the same channel. For example, when using a routing protocol such as AODV (Ad hoc On-Demand Distance Vector), the collection device has the number of hops. Collect data from terminals that become shorter.

  In the system as described above, for example, when the collection device A and the collection device B exist in the system, the number of terminals from which the collection device B collects data increases as the number of terminals that shorten the number of hops to the collection device B increases. However, there may be a case where the capacity of the collection device B is exceeded and data cannot be collected.

  Therefore, in a system that collects data using a mesh network, the load distribution of the collection device is required. For example, in Patent Document 2 below, as a method of distributing the processing load, each terminal configuring the mesh network grasps its own processing load, transmits a route construction message including the load information, and loads Load distribution is realized by selecting a route in consideration of information.

JP 2002-2108080 A Japanese Patent Laid-Open No. 2006-212375

  However, according to the conventional load balancing technique, as the number of terminals that construct and connect paths to a specific collection device based on load information, that is, the number of terminals that can be accommodated increases, Collection load increases. At this time, when a terminal that can be connected only to a high-load collection device is newly added, the high-load collection device accommodates the terminal. Therefore, there has been a problem that a case where the load cannot be distributed occurs. That is, there is a problem that the load cannot be distributed appropriately only by considering the load distribution during the route search process.

  The present invention has been made in view of the above, and an object of the present invention is to provide a communication system and a node management method that can appropriately perform load distribution of devices that accommodate terminals constituting a mesh network.

  In order to solve the above-described problems and achieve the object, the present invention includes a node, a data collection device that collects data by wireless communication from a node managed by the node, and a control device. The node and the data collection device constitute a mesh network, and the node transmits adjacent node information, which is information of a node adjacent to the node, to the data collection device, and the data collection device The adjacent node information is transmitted to the control device, and the node managed by itself is transmitted to the control device as managed node information, and the control device is configured for each data collection device based on the received adjacent node information. Nodes that can be connected to the data collection device, and the information of the obtained nodes is held as network configuration information. When it is determined that there is a data collection device exceeding a certain load threshold, based on the network configuration information and the managed node information, the data collection device manages a data other than the data collection device. Select a node that can be connected to the device as a selection node, select a data collection device that can be connected to the selected node, instruct the selected data collection device to manage the selected node, and receive the instruction The data collection device that has made the selected node the management target of the selected node based on the instruction.

  According to the present invention, the control device holds, as network configuration information, a node that can communicate with each data collection device, and when the load of the data collection device exceeds the load threshold, based on the network configuration information. Since a node that can communicate with other data collection devices is selected from among the nodes accommodated by the data collection device, an instruction is given to change the data collection device that accommodates the selected node. There is an effect that it is possible to appropriately perform load distribution of a device that accommodates a terminal to be configured.

FIG. 1 is a diagram illustrating a configuration example of a communication system according to the first embodiment. FIG. 2 is a diagram illustrating a configuration example of a communication system when a node is newly connected. FIG. 3 is a chart showing an example of a basic operation of data collection according to the first embodiment. FIG. 4 is a diagram illustrating an example of network configuration information. FIG. 5 is a chart diagram illustrating an example of load distribution processing according to the first embodiment. FIG. 6 is a diagram illustrating a configuration example after the load distribution process according to the first embodiment is performed. FIG. 7 is a chart illustrating an example of load distribution processing according to the second embodiment. FIG. 8 is a chart diagram illustrating an example of load distribution processing according to the third embodiment.

  Embodiments of a communication system and a node management method according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a diagram showing a configuration example of a first embodiment of a communication system according to the present invention. The communication system according to the present embodiment includes an operation center 1, data collection devices 2-1 and 2-2 that have a wireless communication function and collect data, and a data collection device 2-1 that has a wireless communication function. Nodes 3-1 to 3-8, which are wireless terminals that transmit data to 2-2. The data collection devices 2-1 and 2-2 and the nodes 3-1 to 3-8 construct a mesh network starting from one of the data collection devices 2-1 and 2-2. In FIG. 1, the number of nodes is 8 and the number of data collection devices is 2. However, the number of nodes and data collection devices is not limited to this, and any number of nodes and data collection devices may be used.

  The nodes 3-1 to 3-8, for example, acquire information such as temperature measured by a sensor mounted on the node 3-1 or acquire information from other devices using serial communication or infrared communication, and collect data. Based on a request from the device 2-1 or the data collection device 2-2, information acquired by using a route to the data collection device 2-1 or the data collection device 2-2 constructed on the mesh network is used as data. Send. Further, the band between the Operation Center 1 and the data collection devices 2-1 and 2-2 is larger than the band used for wired connection or between the data collection devices 2-1 and 2-2 and the nodes 3-1 to 3-8. Wireless connection using the band.

  Further, in FIG. 1, a group constituted by a node (a node that transmits data to the data collection device 2-1) accommodated by the data collection device 2-1 and the data collection device 2-1 is referred to as a block 4-1. A group constituted by a node accommodated by the data collection device 2-2 and the data collection device 2-2 is shown as a block 4-2. In the example of FIG. 1, it is assumed that the nodes 3-1 to 3-4 are accommodated in the data collection device 2-1, and the nodes 3-5 to 3-8 are accommodated in the data collection device 2-2.

  Various routing protocols for constructing a route in a mesh network have been proposed, but any routing protocol may be used in the present embodiment. Also, any method may be used for the wireless protocol and the wireless chip, and any hardware may be used.

  FIG. 2 is a diagram illustrating a configuration example of a communication system when nodes 3-9 to 3-12 are newly connected to the configuration illustrated in FIG. Here, there is a path connecting the nodes 3-9 to 3-12 and the data collection apparatus 2-2, but there is a path connecting the nodes 3-9 to 3-12 and the data collection apparatus 2-1. Do not do. Therefore, based on the conventional route selection method, the nodes 3-9 to 3-12 belong to the block B and transmit data to the data collection device 2-2. Here, even if the capacity of the data collection device 2-2 (processing capacity) is exceeded by newly accommodating the nodes 3-9 to 3-12, the conventional route selection method still uses the node 3-9. ˜3-12 belong to the block B, and data is transmitted to the data collection device 2-2. In the present embodiment, the following processing is performed in order to deal with such a problem.

  First, the basic operation of data collection of the communication system according to the present embodiment will be described. FIG. 3 is a chart showing an example of the basic operation of data collection according to this embodiment. Here, as an example, the exchange between the nodes 3-6 and 3-7 and the data collection device 2-2 and between the data collection device 2-2 and the Operation Center 1 is shown. The same exchange as that of the data collection device 2-2 is performed, and the same operation is performed between the data collection device 2-1 and the Operation Center 1.

  As shown in FIG. 3, when the node 3-6 is activated, the node 3-6 transmits a route search message to all the data collection devices grasped by the node 3-6 or to a data collection device appropriately selected based on a predetermined rule (step S11). ). The route search message is a message for searching for a route to the destination device in the mesh network. The route search message is broadcast to the adjacent node, and whether the adjacent node holds the route to the destination device. Messages for inquiring sequentially. Here, it is assumed that the node 3-6 and the node 3-7 are adjacent to each other, and there is a path from the node 3-6 to the data collection device 2-2 via the node 3-7. In this case, the route search message is transmitted to the data collection device 2-2 via the node 3-7.

  When receiving the route search message, the data collection device 2-2 returns a response to the route search message (step S12). When the node 3-6 receives a response to the route search request message transmitted from the node 3-6 from the data collection device, the node 3-6 sends the ID (of the node) to the data collection device that is the shortest hop among the data collection devices that have responded. A registration notification including Identifier is transmitted (step S13). Here, it is assumed that the data collection device 2-2 is the shortest hop, and the node 3-6 transmits a registration notification to the data collection device 2-2. If there is a response from only one data collection device, a registration notification is transmitted to that data collection device.

  Here, as a basic operation, a case will be described in which the load (the number of nodes to be accommodated, the data collection rate, etc.) of the data collection device does not exceed a predetermined load threshold. In this case, for the node that transmitted the route search request message, the data collection device that has the shortest hop collects data for that node.

  When the data collection device 2-2 receives the registration notification, the data collection device 2-2 performs a process of adding a new node (node 3-6) to the block 4-2 managed by the data collection device 2-2, and also adds the node 3 to the block 4-2 managed by the data collection device 2-2. The operation center 1 is notified that -6 has been added (step S14). In the present embodiment, the data collection device that has received the registration notification starts data collection for the node that has transmitted the registration notification. When data collection is started, the data collection device 2-2 transmits a data acquisition request message for requesting data acquisition to the registration notification transmission source node (here, the node 3-6) (step S15). Then, the node (here, the node 3-6) that has received the data acquisition request message transmits a response message to the data acquisition request message to the data collection device 2-2 (step S16). After that, the data collection device 2-2 transmits a data collection message to the node to which the data acquisition request message is transmitted (here, the node 3-6), and starts data collection.

  In addition, as a method of acquiring information (for example, network ID etc.) for each node to connect to the data collection device, any method such as a method of holding in advance or a method of inquiring an adjacent node is used. May be.

  In this embodiment, the operation center 1 manages the position of each node. The management method is realized by acquiring information on adjacent nodes of each node (information on which node is adjacent). . Specifically, for example, each node may add its own routing table information to the registration notification message, or separately send a message to the data collection device and receive the message. The data collection device may notify the Operation Center 1.

  In addition, as a method for each node to acquire information on adjacent nodes, for example, there is a method in which a message for acquiring information on adjacent nodes is transmitted by broadcast and grasped based on a response to the message. In addition, when a route search request message is broadcast, if there is an adjacent node, the node forwards the route search request message by broadcast, so a method of grasping the adjacent node by receiving the route search request message But it ’s okay.

  The Operation Center 1 grasps the configuration of the mesh network based on information (adjacent information) of adjacent nodes of each node, and holds the state as network configuration information. FIG. 4 is a diagram illustrating an example of network configuration information. In the example of FIG. 4, for each data collection device, an identifier of a node that can communicate with the data collection device (a node in which a route to the data collection device exists) (here, a code attached to the node for convenience is used as the identifier). ) For each number of hops. The number of hops is the number of hops from the node to the data collection device. In addition, when the operation center 1 receives additional information on a node notified from the data collection device (for example, the notification in step S14), the operation center 1 acquires information on the node and adds it to the network configuration information.

  Next, a description will be given of the load distribution processing performed in the present embodiment when the number of nodes accommodated by a data collection device exceeds the load threshold of the data collection device (for example, data collection in FIG. 2). When the device 2-2 exceeds the load threshold). FIG. 5 is a chart showing an example of load distribution processing according to the present embodiment. Here, it is assumed that the data collection device 2-2 has exceeded the load threshold. First, when the data collection device 2-2 determines that its own load has exceeded the load threshold value, the data collection device 2-2 transmits a load distribution request message to that effect to the Operation Center 1 (step S21).

  The Operation Center 1 that has received the load balancing request message, based on the network configuration information that is held, has the load that does not exceed the threshold among the nodes accommodated by the data collection device that is the source of the load balancing request message The node that can communicate with the data collection device (hereinafter referred to as the migration destination data collection device) and has the shortest hop number on the route to the data collection device that is the transmission source is selected. Note that the Operation Center 1 knows the nodes accommodated by each data collection device, for example, using the notification in step S14 described above.

  For example, when the load of the data collection device 2-2 exceeds the load threshold due to the addition of the nodes 3-9 to 3-12 as in the example of FIG. 2, the communication with the data collection device 2-1 is possible. Then, the node 3-6 having the shortest hop count is selected to the data collection device 2-2. The Operation Center 1 transmits a collection notification message for notifying the migration destination data collection device (here, the data collection device 2-1) to collect data from the selected node (step S22). Here, assuming that the node 3-6 is selected, a collection notification message for notifying the data collection device 2-1 that can communicate with the node 3-6 to start data collection is transmitted from the node 3-6.

  The data collection device (data collection device 2-1) that has received the collection notification message determines whether or not the route relating to the node (node 3-6) notified by the message is held (step S23). When the route is held (Yes at Step S23), the process proceeds to Step S26, and data collection is started. When the route is not held (No at Step S23), the route to that node is searched. A route search message is transmitted (step S24). Then, the node 3-6 transmits a response message to the route search message (step S25), and the data collection device 2-1 receives the response message.

  Then, the data collection device 2-1 transmits a data acquisition request message to the node 3-6 (step S26), and the node 3-6 transmits a response to the acquisition request message (step S27). Thereafter, the data collection device 2-1 transmits a data collection message to the node 3-6, and starts data collection. In this way, the node 3-6 accommodated in the data collection device 2-2 (transmitting data) is accommodated in the data collection device 2-1.

  In addition, as a method of determining the load of each data collection device, for example, the operation center 1 periodically notifies the information such as the number of managed data collection devices to the operation center 1 or collects data from the operation center 1. The load status of each data collection device is grasped by a method such as periodically inquiring the device.

  FIG. 6 is a diagram illustrating a configuration example after performing the load distribution processing according to the present embodiment for the state of FIG. In the state of FIG. 2, the number of nodes accommodated by the data collection devices 2-1 and 2-2 is 4 and 8, respectively, and the load of the data collection device 2-2 is high. Through the above load distribution processing, the nodes 3-5 and 3-6 that were accommodated in the data collection device 2-2 are accommodated in the data collection device 2-1, and the data collection devices 2-1 and 2-2 are accommodated. The number of nodes to be used is six each, and the load is distributed.

  In the present embodiment, each data collection device transmits a load distribution request message when its own load exceeds the load threshold, and Operation Center 1 performs processing based on the load distribution request message. However, the present invention is not limited to this, and if the operation center 1 knows the load of each data collection device and there is a data collection device that exceeds the load threshold, the processing from step S22 onward is performed for that data collection device. You may make it implement.

  In the present embodiment, the collection notification message for notifying the data collection device 2-1 to start data collection from the node 3-6 is transmitted to the data collection device 2-1 in step S23. 6 may be notified to connect to the data collection device 2-1. In that case, when the node 3-6 holds a route to the data collection device 2-1, the node 3-6 transmits to the data collection device 2-1. When the node 3-6 does not hold the route, the route search is performed. Is transmitted to the data collection device 2-1, and then the data collection device 2-1 transmits a data acquisition request message to the node 3-6.

  As described above, in the present embodiment, the Operation Center 1 holds, as network configuration information, a node that can communicate with each device and the number of hops to that device for each data collection device, and the data collection device has its own load. When the load threshold is exceeded, a load distribution request message is transmitted to the Operation Center 1. The operation center 1 can communicate with the migration destination data collection device whose load does not exceed the threshold among the nodes accommodated by the data collection device of the message transmission source based on the network configuration information, and the transmission source The node having the shortest number of hops along the route to the data collection device is selected, and a collection notification message for notifying the migration destination data collection device to start data collection from the selected node is transmitted. The migration destination data collection device that has received the collection notification message collects data from the node based on the message. Therefore, it is possible to appropriately perform load distribution of the data collection device that accommodates the nodes constituting the mesh network.

Embodiment 2. FIG.
FIG. 7 is a chart showing an example of load distribution processing according to the second embodiment of the communication system according to the present invention. The configuration of the communication system of the present embodiment is the same as that of the first embodiment. Components having the same functions as those in the first embodiment will be described with the same reference numerals as those in the first embodiment.

  In this embodiment, in consideration of the fact that when the load is concentrated on the data collection device and the processing capacity is exceeded, transmission / reception of the data collection message will not be performed normally, each node receives a predetermined value from the reception of the data acquisition request message. If the data collection message does not arrive even after the time elapses, it is determined that the data collection device exceeds the load threshold value, and connection with another data collection device is performed.

  As shown in FIG. 7, first, the data collection device 2-2 transmits a data acquisition request message to the node 3-6 (step S31). Then, the node 3-6 transmits a response message to the message to the data collection device 2-2 (step S32). Further, when the node 3-6 receives the data acquisition request message, the node 3-6 starts a timer and waits for a data collection message until a predetermined time set in the timer elapses (step S33). When the node 3-6 receives the data collection message, the node 3-6 stops the timer.

  When the started timer times out (when the data collection message is not received even after a predetermined time elapses), the node 3-6 selects another data collection device known by itself (in this case, the data collection) If it is determined that the device 2-1 is selected), it is determined whether or not the route to the selected data collection device is held (step S34). If it is determined that the route is retained (Yes in step S34), the process proceeds to step S37. If it is determined that the route is not retained (No in step S34), the process proceeds to the selected data collection device 2-1. A route search message for searching for a route is transmitted (step S35).

  The data collection device 2-1 that has received the route search message transmits a response message to the route search message (step S 36). Then, the node 3-6 transmits a registration notification including the ID of the own node to the data collection device 2-1 (step S37). When the data collection device 2-1 receives the registration notification, the data collection device 2-1 notifies the Operation Center 1 that the node 3-6 has been added to the block 4-1 managed by the data collection device 2-1. When the operation center 1 receives this notification, the operation center 1 checks whether the notified node is managed by another data collection device, and if it is managed by another data collection device, the operation center 1 Notify to stop data collection.

  After step S38, the data collection device 2-1 transmits a data acquisition request message to the node 3-6 (step S39). Then, the node 3-6 transmits a response message to the message to the data collection device 2-1 (step S40). Thereafter, a data collection message is transmitted from the data collection device 2-1, and data collection from the node 3-6 is started.

  Here, the node 3-6 has been described as an example, but each node performs the above-described processing in the same manner as the node 3-6 using a timer. The operations of the present embodiment other than those described above are the same as those of the first embodiment. By performing such processing, when there is a data collection device exceeding its own processing capability, a node accommodated in the data collection device can change the data collection device accommodated.

  In addition, although the above load distribution process was demonstrated as a method different from Embodiment 1, you may make it use the load distribution process of Embodiment 1 and the load distribution process of this Embodiment together here.

  As described above, in this embodiment, when each node receives a data acquisition request message, the timer is started, and even if a time-out occurs, the data collection message does not arrive from the data collection device that is the transmission source of the data acquisition request message. In some cases, registration notifications are sent to other data collection devices. Therefore, when there is a data collection device whose processing load exceeds the allowable value, the node accommodated in the data collection device can be accommodated in another data collection device, and the load distribution of the data collection device is appropriately distributed. Can be done.

Embodiment 3 FIG.
FIG. 8 is a chart showing an example of load distribution processing according to the third embodiment of the communication system according to the present invention. The configuration of the communication system of the present embodiment is the same as that of the first embodiment, but in this embodiment, each data collection device communicates with a node accommodated by itself using different radio channels. Assuming Components having the same functions as those in the first embodiment will be described with the same reference numerals as those in the first embodiment.

  Each node is given and holds in advance information on which data collection device it can connect to, or there is a data collection device that can connect to adjacent nodes while changing the radio channel To determine which data collection device can connect to itself. The processing for determining which data collection device each node performs registration notification is a method of performing a route search in the same manner as in the first embodiment and notifying the data collection device that is the shortest hop. Alternatively, a registration notification may be transmitted to the selected data collection device.

  The Operation Center 1 grasps the arrangement of each node by the following method, and holds the grasped arrangement of each node as network configuration information as in the first embodiment. Each node transmits a message by broadcast while changing a radio channel at the time of activation, and other nodes other than the transmission source send the message back to the transmission source node when receiving the message. By performing this operation for all the radio channels used in the communication system, it is possible to obtain information on what kind of nodes are adjacent to each other. Each node notifies the data collection device of the acquired information, and the notified data collection device transfers the information to the Operation Center 1.

  Next, returning to FIG. 8, the load distribution processing according to the present embodiment will be described. As in the example of FIG. 2, when the load of the data collection device 2-2 exceeds the load threshold, the data collection device 2-2 transmits a load distribution request message for requesting load distribution processing to the Operation Center 1 (step S41). The Operation Center 1 that has received the load distribution request message selects a node that can communicate with another data collection device (migration destination data collection device) among the nodes accommodated by the data collection device that is the transmission source of the message, A channel change request message for requesting to change the radio channel to the selected node and to connect to the migration destination data collection device is transmitted (step S42). At this time, as in the first embodiment, among the nodes that can communicate with other data collection apparatuses, a node having the shortest hop number on the path to the apparatus may be selected. Note that the changed wireless channel requested by this message is the wireless channel used by the migration destination data collection device. Hereinafter, an example in which the node 3-6 is selected and the migration destination data collection device is the data collection device 2-1 will be described.

  Upon receiving the channel change request message, the node 3-6 determines whether or not it holds a route to the data collection device 2-1 that is the migration destination data collection device requested by the message (step S43). . If it is determined that the route is held (Yes at Step S43), the process proceeds to Step S46. If it is determined that the route is not held (No at Step S43), the route to the data collection device 2-1 is determined. A route search message for searching is transmitted (step S44). The data collection device 2-1 that has received the route search message transmits a response message to the message to the node 3-6 (step S45).

  Then, the node 3-6 transmits a registration notification including its own ID to the data collection device 2-1 (step S46), and the data collection device 2-1 is added by the node 3-6 as a node managed by the node 3-6. This is notified to Operation Center 1 (step S47). The operations of the present embodiment other than those described above are the same as those of the first embodiment.

  In the above example, the data device transmits the load distribution message when its own load exceeds the load threshold. However, the present invention is not limited to this, and the Operation Center 1 periodically sends data to the data collection device. By inquiring, the load state of each data collection device may be grasped, and step S42 and subsequent steps may be performed for the data acquisition device exceeding the load threshold.

  In the above example, the channel change request message is used to request the selected node to change the radio channel and to connect to the migration destination data collection device. In the same manner as in the first embodiment, it is also possible to notify the migration destination data collection device to collect data of the selected node.

  As described above, in the present embodiment, in a communication system in which each data collection device communicates with a node managed by itself using different radio channels, each node changes to an adjacent node while changing the radio channel. In response to the inquiry about whether there is a connectable data collection device, the neighboring information is acquired, the information is transmitted to the data collection device, and the data collection device transfers the information to the Operation Center 1 so that Center 1 now keeps track of the placement of each node. The data collection device transmits a load distribution request message to the Operation Center 1 when its own load exceeds the load threshold, and the Operation Center 1 performs load distribution processing based on the network configuration information. Therefore, even in a communication system in which each data collection device communicates with a node managed by itself using different radio channels, the same effect as in the first embodiment can be obtained.

  As described above, the communication system and the node management method according to the present invention are useful for a communication system that collects data from nodes constituting a mesh network, and in particular, the number of nodes accommodated by the data collection device that performs data collection is large. Suitable for changing communication systems.

1 Operation Center
2-1, 2-2 Data collection device 3-1 to 3-12 Node 4-1, 4-2 Block

Claims (11)

A communication system in which a node, a data collection device that collects data by wireless communication from a node managed by the node, and a control device are included, and the node and the data collection device constitute a mesh network. And
The node transmits adjacent node information, which is information of a node adjacent to the node, to the data collection device,
The data collection device transmits the adjacent node information to the control device, and transmits a node managed by itself to the control device as managed node information,
The control device obtains a node connectable to the data collection device for each data collection device based on the received adjacent node information, holds the obtained node information as network configuration information, and the load is a predetermined load. When it is determined that there is a data collection device exceeding the threshold, based on the network configuration information and the managed node information, a node managed by the data collection device and connected to a data collection device other than the data collection device Select a possible node as a selection node, select a data collection device that can be connected to the selection node, and instruct the selected data collection device to manage the selection node;
The data collection device that has received the instruction sets the selected node as a management target based on the instruction. A communication system in which a node, a data collection device that collects data by wireless communication from a node managed by the node, and a control device are included, and the node and the data collection device constitute a mesh network. And
The node transmits adjacent node information, which is information of a node adjacent to the node, to the data collection device,
The data collection device transmits the adjacent node information to the control device, and transmits a node managed by itself to the control device as managed node information,
The control device obtains a node connectable to the data collection device for each data collection device based on the received adjacent node information, holds the obtained node information as network configuration information, and the load is a predetermined load. When it is determined that there is a data collection device exceeding the threshold, based on the network configuration information and the managed node information, a node managed by the data collection device and connected to a data collection device other than the data collection device Select a possible node as a selection node, select a data collection device that can be connected to the selection node, and instruct the selection node to connect to the selected data collection device;
The node that has received the instruction transmits a registration notification for connecting to the instructed data collection device to the data collection device,
The data collection apparatus that has received the registration notification sets the node that is the transmission source of the registration notification as its management target. The data collection device transmits a load distribution request for requesting load distribution to the control device when its own load exceeds a predetermined load threshold,
3. The control device according to claim 1, wherein when the load distribution request is received, the control device determines that the data collection device that transmitted the request is a data collection device that exceeds the load threshold. The communication system described. The data collection device transmits load information indicating its own load status to the control device,
The communication system according to claim 1, wherein the control device determines whether there is a data collection device whose load exceeds a predetermined load threshold based on the load information.   The communication system according to any one of claims 1 to 4, wherein a node that minimizes the number of hops of a route with a connectable data collection device is selected as the selection node. The frequency used for communication between the data collection device and a node managed by the data collection device is a different frequency for each data collection device,
The said node transmits a predetermined | prescribed message to an adjacent node with each said frequency, and acquires adjacent node information based on the response with respect to those messages, It is any one of Claims 1-5 characterized by the above-mentioned. Communications system. The node instructs the data collection from the data collection device that is the transmission source of the data acquisition request even if a predetermined time has elapsed after receiving the data acquisition request for starting data acquisition from the data collection device. If the data collection request is not received, a data collection device other than the data collection device of the transmission source is selected from among the data collection devices known by itself and connected to the selected data collection device Send a registration notification to the data collector,
The communication system according to any one of claims 1 to 6, wherein the data collection device that has received the registration notification sets the node from which the registration notification is transmitted as a management target. A node, and a data collection device that collects data by wireless communication from a node managed by the node, and the node and the data collection device constitute a mesh network,
The node instructs data collection from the data collection device that is the transmission source of the data acquisition request even if a predetermined time has elapsed after receiving a data acquisition request for starting data acquisition from the data collection device If a data collection request is not received, a data collection device other than the data collection device of the transmission source is selected from among the data collection devices known by itself and connected to the selected data collection device Registration notification to the data collection device,
The data collection apparatus that has received the registration notification sets the node that is the transmission source of the registration notification as its management target. A node in a communication system, comprising: a node; a data collection device that collects data by wireless communication from a node managed by the node; and a control device, wherein the node and the data collection device constitute a mesh network A management method,
An adjacent information transmission step in which the node transmits adjacent node information, which is information of a node adjacent to the node, to the data collection device;
An adjacent information transfer step in which the data collection device transmits the adjacent node information to the control device;
A management information transmission step in which the data collection device notifies the control device of nodes managed by itself as managed node information;
A network configuration information holding step for obtaining a node connectable to the data collection device for each data collection device based on the received adjacent node information, and holding the obtained node information as network configuration information;
When the control device determines that there is a data collection device whose load exceeds a predetermined load threshold, based on the network configuration information and the managed node information, the node managed by the data collection device, and A node that can be connected to a data collection device other than the data collection device is selected as a selection node, a data collection device that can be connected to the selection node is further selected, and the selected node is managed with respect to the selected data collection device A data collection instruction step to instruct;
A data collection device that has received the instruction, a management node changing step in which the selected node is a management target based on the instruction;
A node management method comprising: A node in a communication system, comprising: a node; a data collection device that collects data by wireless communication from a node managed by the node; and a control device, wherein the node and the data collection device constitute a mesh network A management method,
An adjacent information transmission step in which the node transmits adjacent node information, which is information of a node adjacent to the node, to the data collection device;
An adjacent information transfer step in which the data collection device transmits the adjacent node information to the control device;
A management information transmission step in which the data collection device notifies the control device of nodes managed by itself as managed node information;
A network configuration information holding step for obtaining a node connectable to the data collection device for each data collection device based on the received adjacent node information, and holding the obtained node information as network configuration information;
When the control device determines that there is a data collection device whose load exceeds a predetermined load threshold, based on the network configuration information and the managed node information, the node managed by the data collection device, and A node that can be connected to a data collection device other than the data collection device is selected as a selection node, a data collection device that can be connected to the selection node is further selected, and the selected node is connected to the selected data collection device. A data collection change instruction step for instructing
A registration notification transmission step in which the node receiving the instruction transmits a registration notification for connecting to the instructed data collection device to the data collection device;
The data collection device that has received the registration notification is a management node change step in which the node that is the transmission source of the registration notification is its management target,
A node management method comprising: A node management method in a communication system comprising a node and a data collection device that collects data by wireless communication from a node managed by itself among the nodes, wherein the node and the data collection device constitute a mesh network. And
Even if a predetermined time has elapsed since the node received a data acquisition request for starting data acquisition from the data collection device, the node collects data from the data collection device that is the transmission source of the data acquisition request If the data collection request is not received, a data collection device other than the data collection device of the transmission source is selected from among the data collection devices known by itself and connected to the selected data collection device A registration notification step for transmitting a registration notification to the data collection device;
The data collection device that has received the registration notification includes a management node change step in which the node that is the transmission source of the registration notification is a management target,
A node management method comprising:

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