JP2009033536A - Group management method and node - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress traffic without performing multicast transmission when a plurality of pieces of information providing terminals are grouped. <P>SOLUTION: Each of a plurality of nodes 102 stores a group identifier indicating a group of a sensor 103 and a node identifier indicating a node in a lower hierarchy by one ranking belonging to the group by making them associate with each other, when a group specification command including the group identifier is transmitted from a client terminal 101 to the most significant node, determines whether or not the most significant node and nodes not significant than that store the group identifier in the group specification command, and only when the group identifier is stored, transmits the group specification command only to a lower hierarchy by one corresponding to the group identifier. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a group management method for grouping and managing a plurality of information providing terminals in a system in which a client terminal collects information provided by a plurality of information providing terminals via a plurality of hierarchized nodes. The invention also relates to a node in the system.
In particular, the present invention relates to a hierarchical sensor network in which an enormous number of sensors are connected as a plurality of information providing terminals, and a group management method for realizing remote control for sensors while suppressing traffic on the network, and Regarding nodes.

  As information providing terminals, sensors in sensor networks have come to include not only devices that measure meteorological data such as temperature and humidity, but also network cameras that acquire video and still image data. In addition, the number of sensors to be connected has increased, and in the future, operation studies on a large-scale network in which 10 million sensors are connected have begun. For example, the U2 (Universal & Ubiquitous) disaster prevention and security system, which is one of the discussions by the Ministry of Internal Affairs and Communications, provides a service for providing information that overlays disaster information and weather information on map information represented by GoogleEarth. The large-scale sensor network will be applied as an infrastructure for collecting information to be superimposed. The information to be overlaid varies widely, such as wind direction, fire occurrence status, traffic jam information, etc., and the user selects as needed. Each information is converted into data by processing the sensing information acquired from the terminal sensor. In such a system, a wide variety of sensors are installed over a wide range, and a network system capable of performing sensor control for each type is required. At that time, as problems to be overcome, network traffic suppression and sensor control in which sensors are grouped are required.

  Traffic suppression is necessary from the following points. For one, since the number of sensors is enormous, even traffic for simply obtaining sensing information cannot be ignored. The other is that traffic for sensor control, such as changing the direction of the camera as in a network camera, is added as a result of higher functionality of the sensor.

There are three traffic suppression methods in the conventional sensor network.
• The first is to aggregate individual sensing data along the route and reduce the traffic ahead. Data from a plurality of temperature sensors in a certain area is converted to an average value in the area on the way, and only the average value is transmitted after that.
The second method is to multiplex packets transmitted from individual sensors into one packet along the route. That is, the data value from each sensor is left as it is, and the transmission format of the data is changed.
The third method is to divide the network from the sensor to the client terminal that acquires information into a plurality of hierarchies and distribute the traffic load. The lowest hierarchy processes only information from sensors in its own range, and the higher hierarchy is a pyramid type hierarchy in which the lower hierarchy in charge is determined (see Patent Document 1 below).

Control by grouping is necessary to obtain the desired sensing information from a vast number of sensors. Compared to the case where all data is collected at the client terminal and information processing is performed at the client terminal, traffic Contribute to the reduction of Conventionally, IGMP (Internet Group Management Protocol) is used as a protocol for grouping terminals on a network or transmitting data only to the grouped terminals.
JP 2004-208015 A (FIGS. 2 and 3)

  However, since the conventional group management method in the sensor network uses IGMP, even if grouping is possible, the following unnecessary traffic is generated and traffic is not suppressed. This is because the use of IGMP is for a router which is a network repeater, and the router uses data based on IGMP when distributing multicast data to which network. Therefore, the data based on IGMP is not addressed to a specific terminal but is transmitted to the entire network by multicast. For example, when joining a group (JOIN), the JOIN signal is sent by multicast, the router that is the relay point records the network from which the signal came, and the multicast data of the corresponding group to the network from the next time is recorded. It will begin to flow. Further, the router transmits a signal for confirming whether or not there is a terminal belonging to the group to the network in which multicast data is flowing for each group at a frequency of once every 60 seconds.

  Further, the conventional traffic suppression has a limit in a network in which a signal having a large data size flows, such as video data from a network camera. The number that can be multiplexed decreases, and since it is not numerical data, suppression by processing is difficult.

  The present invention has been made to solve the conventional problems, and provides a plurality of information in a system in which a client terminal collects information provided by a plurality of information providing terminals via a plurality of hierarchized nodes. An object of the present invention is to provide a group management method and a node capable of suppressing traffic without performing multicast transmission when grouping terminals.

In order to achieve the above object, the present invention groups a plurality of information providing terminals in a system in which a client terminal collects information provided by a plurality of information providing terminals via a plurality of hierarchized nodes. In the group management method to manage,
Each of the plurality of nodes corresponds to a group identifier indicating a group of the information providing terminals, a node identifier indicating a node of a hierarchy one level lower belonging to the group, or an information providing terminal identifier indicating the information providing terminal. Storing in a table;
Transmitting a group designation command including the group identifier from the client terminal to the highest node;
It is determined whether or not the highest-order node and the lower-order node that has received the group designation command store the group identifier in the group designation command in the table. And a step of transmitting the group designation command to a node one level below corresponding to the group identifier or the information providing terminal.
With this configuration, since the group designation command is not transmitted to a node in the lower hierarchy that does not have the information providing terminal of the command transmission destination group, traffic can be suppressed.

In order to achieve the above object, the present invention groups a plurality of information providing terminals in a system in which a client terminal collects information provided by a plurality of information providing terminals via a plurality of hierarchized nodes. In the group management method to manage
The lowermost node connected to the information providing terminal registers a correspondence relationship between a group identifier indicating the group of the information providing terminals and an information providing terminal identifier indicating the information providing terminal in a table, and the information providing terminal Sending a group registration command including the group identifier of the node and the node identifier of the own node to a node in the upper hierarchy;
The node that has received the group registration command registers the correspondence between the group identifier and the node identifier in the group registration command in the table, and the group identifier only when the registered group identifier is a new registration. And a step of transmitting a group registration command including a node identifier indicating the own node to a node of a higher hierarchy,
Each of the plurality of nodes corresponds to a group identifier indicating a group of the information providing terminals, a node identifier indicating a node of a hierarchy one level lower belonging to the group, or an information providing terminal identifier indicating the information providing terminal. It was configured to be registered in the table.
With this configuration, since a group registration command is not transmitted to a node in the upper hierarchy that does not have an information providing terminal that is a group registration target, traffic can be suppressed.

In order to achieve the above object, the present invention groups a plurality of information providing terminals in a system in which a client terminal collects information provided by a plurality of information providing terminals via a plurality of hierarchized nodes. In the group management method to manage
Each of the plurality of nodes corresponds to a group identifier indicating a group of the information providing terminals, a node identifier indicating a node of a hierarchy one level lower belonging to the group, or an information providing terminal identifier indicating the information providing terminal. Storing in a table;
The lowermost node connected to the information providing terminal deletes the correspondence between the group identifier of the information providing terminal and the information providing terminal identifier from the table, and indicates the group identifier of the information providing terminal and the own node. Sending a group leaving command including a node identifier to a node in the upper hierarchy;
Only when the node that has received the group leave command deletes the correspondence between the group identifier and the node identifier in the group leave command from the table and does not register the deleted group identifier in the table, And a step of transmitting a group leaving command including the group identifier and a node identifier indicating its own node to a node in the next higher hierarchy.
With this configuration, since the group deletion command is not transmitted to a node in the upper hierarchy that does not have an information providing terminal that is a group deletion target, traffic can be suppressed.

In order to achieve the above object, the present invention groups a plurality of information providing terminals in a system in which a client terminal collects information provided by a plurality of information providing terminals via a plurality of hierarchized nodes. The node in the network to be managed,
A storage unit that stores a group identifier indicating the group of the information providing terminals, a node identifier indicating a node of the next lower hierarchy belonging to the group, or an information providing terminal identifier indicating the information providing terminal;
When a group designation command including the group identifier is transmitted from the client terminal to the highest node, it is determined whether or not the group identifier in the group designation command is stored in the storage means, and stored. And a means for transmitting the group designation command to a node in the next lower hierarchy corresponding to the group identifier or to the information providing terminal.
With this configuration, since the group designation command is not transmitted to a node in the lower hierarchy that does not have the information providing terminal of the command transmission destination group, traffic can be suppressed.

In order to achieve the above object, the present invention groups a plurality of information providing terminals in a system in which a client terminal collects information provided by a plurality of information providing terminals via a plurality of hierarchized nodes. The node in the network to be managed,
A storage unit that stores a group identifier indicating the group of the information providing terminals, a node identifier indicating a node of the next lower hierarchy belonging to the group, or an information providing terminal identifier indicating the information providing terminal;
In the case of the lowest layer node connected to the information providing terminal, the correspondence relationship between the group identifier of the information providing terminal and the information providing terminal identifier is registered in the storage means, and the group identifier of the information providing terminal Means for transmitting a group registration command including a node identifier of a node to a node of a higher hierarchy;
When the group registration command is received, the correspondence between the group identifier and the node identifier in the group registration command is registered in the storage unit, and only when the registered group identifier is newly registered, The system includes a means for transmitting a group registration command including a group identifier and a node identifier indicating its own node to a node in the next higher hierarchy.
With this configuration, since a group registration command is not transmitted to a node in the upper hierarchy that does not have an information providing terminal that is a group registration target, traffic can be suppressed.

In order to achieve the above object, the present invention groups a plurality of information providing terminals in a system in which a client terminal collects information provided by a plurality of information providing terminals via a plurality of hierarchized nodes. The node in the network to be managed,
A storage unit that stores a group identifier indicating the group of the information providing terminals, a node identifier indicating a node of the next lower hierarchy belonging to the group, or an information providing terminal identifier indicating the information providing terminal;
In the case of the lowest layer node connected to the information providing terminal, the correspondence relationship between the group identifier of the information providing terminal and the information providing terminal identifier is deleted from the storage unit, and the group identifier of the information providing terminal Means for transmitting a group leaving command including a node identifier indicating a node to a node in the upper hierarchy;
When the group leaving command is received, the correspondence between the group identifier and the node identifier in the group leaving command is deleted from the storage unit, and the deleted group identifier is not registered in the storage unit Only the group leaving command including the group identifier and the node identifier indicating the own node is transmitted to a node in the upper hierarchy.
With this configuration, since the group deletion command is not transmitted to a node in the next lower hierarchy that does not have the information providing terminal to be deleted, the traffic can be suppressed.

  According to the present invention, since no command is transmitted to a node that does not have a group information providing terminal, traffic can be suppressed.

<First Embodiment>
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a first embodiment of a group management method and nodes according to the present invention. In FIG. 1, a plurality of sensors 103 (sensors 1, 2, 3 to X, Y, 1 to Z) as information providing terminals are networked by a plurality of hierarchical nodes 102 (nodes A to I). The client terminal 101 that processes data acquired from the sensor 103 (hereinafter referred to as sensing data) is connected to the highest hierarchical node 102 (node A). The sensor 103 can include not only data that acquires numerical data such as temperature and humidity, but also data that acquires multimedia data such as moving images and still images, such as a network camera.

  The client terminal 101 sends a control signal such as requesting the sensor 103 to send sensing data or changing the camera orientation to the sensor 103 such as a network camera. The node 102 (nodes A to I) corresponds to a relay device of the network between the client terminal 101 and the sensor 103, the highest node A is connected to the client terminal 101, and the lowest layer nodes E to I are the sensor 103. Connected with. There are cases where the node 102 is configured by a single device, and cases where the node 102 indicates a gateway in a specific local area network are conceivable.

  The plurality of nodes 102 have a clear hierarchical order, and a signal from the client terminal 101 is sent only from the upper node 102, and a signal from the sensor 103 is sent only from the lower node 102. A feature of the hierarchical network is that not all nodes are in a parallel position like a bus network. In this system, the sensors 103 are grouped according to usage (hereinafter referred to as grouping), and each node 102 is associated with a group and a lower level node 102 (the lowest level node is the sensor 103) constituting the group. Is remembered.

In FIG. 1, the sensors 1, 2, 3 of the sensors (1, 2, 3-X) and the sensor 1 of the sensors (1-Z) are in one group (group # 1: circled in the figure). The numbers belong to #) in this specification, and the nodes A, B, D, E, and I shown as the group # 1 have a group ID (group # 1) and a lower configuration node or sensor. The correspondence information is shown. The correspondence relationship of this example is shown below.
Node A: Group # 1 → Node B, D
Node B: Group # 1 → Node E
Node E: Sensors 1 to 3 of group # 1 → sensor (1, 2 to X)
Node D: Group # 1 → Node I
Node I: sensor # 1 of group # 1 → sensor (1-Z)

  A thick arrow indicates a control signal from the client terminal 101 via the nodes A, B, D, E, and I. The client terminal 101 can issue a control signal based on group designation, and each node 102 determines the transmission destination of the received signal based on the correspondence information between the group and the lower-level node 102 or the sensor 103, and Signal transmission is suppressed. In the example of FIG. 1, only a thick arrow flows through the control signal.

  FIG. 2 shows the configuration of the group management apparatus 201 according to the first embodiment of this invention. The group management apparatus 201 shows functions in the node 102 as an apparatus. In FIG. 2, the group management apparatus 201 according to the first embodiment of the present invention analyzes a packet receiving unit 202 that receives an IP packet, which is a signal in the network, and the contents of the packet received by the packet receiving unit 202. A packet distribution unit 203 that determines whether the signal is a group designation signal, a destination management table 205 that stores correspondence information between groups and lower-level nodes or sensors that constitute the group, and, in the case of a group designation signal, destination management A destination acquisition unit 204 that acquires information of a corresponding lower-level node or sensor from the table 205, and an IP packet that is received by the number of destinations acquired from the destination acquisition unit 204 are generated, and the destination of the IP packet is determined from the destination acquisition unit 204. The packet construction unit 206 that replaces the acquired destination and the I generated by the packet construction unit 206 Composed of the packet transmission unit 207 for transmitting a packet onto the network.

  FIG. 3 shows the configuration of the destination management table 205. The table 205-1 shown in FIG. 3A shows a case where the node 102 is one level below the own node, and groups # 1, # 2 (FIG. , A group identifier 301 indicating a circled number) and a node identifier 302 indicating nodes B and D in a hierarchy one level lower than the own node belonging to groups # 1 and # 2 are stored in association with each other. A table 205-2 shown in FIG. 3B shows a case where the sensor 103 is one level below the own node. The group identifier 301 indicating the group # 1 and one of the own nodes belonging to the group # 1. Sensor identifiers 303 indicating the sensors 1, 2, and 3 in the lower layers are stored correspondingly. The table 205 may have a configuration in which the node identifier 302 and the sensor identifier 303 are mixed.

  FIG. 4 shows the structure of a control IP packet 400a transmitted from the client terminal 101 to the sensor 103. The packet 400a includes an IP header 401, a TCP / UDP header 402, and a command indicating the use of the IP packet. It consists of a type 403, a group name 404 indicating a group designation signal, and a command parameter 405 which is a parameter value associated with the command. When the camera control command 400 a is transmitted to the group # 1, “group # 1” is stored in the group name 404 and an identifier indicating “camera control” is stored in the command type 403.

  The operation of the group management method and the nodes in the first embodiment or more will be described with reference to the flowchart 11 shown in FIG. First, an IP packet of a control signal is transmitted from the client terminal 101 to the first layer node A. The node A in the first layer receives the IP packet by the packet receiving unit 202. The packet distribution unit 203 analyzes the received packet data, and determines whether it is a group designation command or a packet that normally flows between networks like other PINGs depending on the presence or absence of the group name 404 (step). S101). If the command is a normal command, the received packet is transmitted to the lower layer via the packet transmission unit 207 (step S104).

  In the case of a group designation command, the destination acquisition unit 204 searches the destination management table 205 based on the group name 404 in the packet, and acquires a list of node identifiers 302 corresponding to the matching group identifier 301 (step S102). . The packet construction unit 206 duplicates the packet by the number of acquired node identifiers 302 and replaces the destination (node A) with the destinations (node B, D) of the node identifier 302 acquired from the destination management table 205 (step S103). The generated packet is transmitted to the lower layer via the packet transmission unit 207 (step S104). The above operation is performed by the node 102 in each layer, and the sensor 103 is performed in the nodes E and I in the lowest layer.

  According to the group management method and node in the sensor network of the first embodiment of the present invention as described above, a group designation command is identified in each node 102 in the hierarchical network, and the destination management table 205 in the node 102 is used. Since the destination corresponding to the specified group is determined and IP packets are transmitted only to the corresponding destination, unnecessary packets are not sent to the sensor-only nodes that do not belong to the group, and the entire network traffic is suppressed. be able to.

  A specific example is shown in FIG. In a network in which 10 million sensors 103 exist and each layer is managed in units of 100, if an IP packet of about 200 bytes is transmitted as a control signal for sensing data acquisition, one sensor is used if transmission by grouping is not performed. Since a control signal is sent every time, 2 GB of traffic flows between the client terminal 101 and the first layer node, and 0.2 GB of traffic flows between the first layer and the second layer. In the transmission of the control signal in the group designation according to the present invention, since the packet is duplicated at the node 102, traffic between the client terminal 101 and the first layer node 102 and 200 bytes of traffic for each packet starts between the nodes 102. Will be enough. Also, since packets are not sent to unnecessary hierarchies, the amount of traffic can be greatly reduced as compared with the prior art.

<Second Embodiment>
Next, FIG. 7 shows a group management method in the sensor network according to the second embodiment of this invention. In the second embodiment, an additional registration function for group information is added to the first embodiment. FIG. 7 shows a mechanism for additionally registering the sensor Y under the node H in the group # 1.
(1) First, communication indicating that it belongs to the group # 1 is sent from the sensor Y to the node H, which is an upper node.
(2) The node H receives the signal and additionally registers the correspondence information between the group # 1 and the sensor Y in the destination management table 205 in the node H.
(3) Further, since the registration for the group # 1 is the first time in the node H, a signal indicating that the node H belongs to the group # 1 is sent to the node D, which is the upper node.
(4) The node D receives the signal and registers the correspondence information between the group # 1 and the node H in the destination management table 205 in the node D. Furthermore, since registration (node I) relating to group # 1 has already been made in node D, a signal indicating that node D belongs to group # 1 is not sent to node A, which is a higher node.

  If the sensor Y does not have an IP communication mechanism, the upper node H sets the group # 1 to which the managed sensor Y belongs, and updates the destination management table 205 in the own node H. Subsequent transmission of the group registration signal to the upper node D follows the above-described sequence.

  FIG. 8 shows a group management apparatus 201a in the sensor network according to the second embodiment of the present invention. The packet distribution unit 203 in the configuration of the first embodiment analyzes the packet contents and sends a group registration signal. In the case of a group registration signal, a destination update unit 601 for adding new correspondence information between a group and a node or a sensor is added to the destination management table 205, and the destination management table 205 is added. A command transmission determination unit 602 is provided to check whether the added information is a new group and to determine whether or not the own node's group registration with respect to the upper node is necessary, and generates a group registration packet when it is determined to be necessary This is configured by adding means to the packet construction unit 206.

  FIG. 9 shows the structure of IP packets 400b and 400c for group registration. A packet 400b in FIG. 9A shows a structure when the sensor 103 (sensor Y) is registered as a group, and a packet 400c in FIG. 9B shows a structure when the node 102 (node H) is registered as a group. Yes. A packet 400b shown in FIG. 9A designates an IP header 401, a TCP / UDP header 402, a command type 701 indicating “group registration” as the use of the IP packet, and an identifier of a group to be registered. Group name 404 and sensor name 702 for designating the identifier of sensor Y to be registered. The packet 400c shown in FIG. 9B is composed of a node name 703 that specifies the identifier of the node H to be registered instead of the sensor name 702, and the other fields are the same as those in FIG. 9A. is there.

  The operation of the group management method and nodes in the sensor network configured as described above will be described with reference to FIG. First, the group registration packets 400b and 400c are issued by the sensor 103 or the lower node 102. The issued packet is received by the packet receiving unit 202 of the upper node. The packet distribution unit 203 analyzes the received packet data, and detects the group registration packets 400b and 400c depending on whether or not the command type 701 of the group registration packet indicates “group registration” (step S201). Packets other than “group registration” are transmitted as they are to the upper node (step S104).

  In the case of the group registration packets 400b and 400c, the destination update unit 601 registers the correspondence information between the group name 404 and the node name 703 or the sensor name 702 in the packets 400b and 400c in the destination management table 205 (step S202). The destination update unit 601 transmits the registered group name to the command transmission determination unit 602, and the command transmission determination unit 602 determines whether or not only one registered group name is registered in the destination management table 205. (Step S203). When there is only one, the group is registered for the first time for the own node, and the packet construction unit 206 generates the packets of the group registration commands 400b and 400c for informing the upper node 102 that the own node belongs to the group ( Step S204). The generated group registration packets 400b and 400c are transmitted to the upper node 102 by the packet transmission unit 207 (step S104). If there are a plurality of registered group names in the destination management table 205, it can be determined that the upper node 102 already knows that the own node belongs to the group, so the processing is completed.

  As described above, according to the group management method and the node in the sensor network according to the second embodiment of the present invention, the group registration command is issued from the lower layer, and the received node 102 is the destination management table in the own node 102. If the correspondence between the group name and the lower-level node 102 belonging to the group 205 is registered, and if it is the first group registered in the own node 102, the group registration command 400b indicating that the own node 102 belongs to the above group to the higher-level node 102. , 400c, group registration can be performed in a chained manner with minimum traffic.

<Other examples of group registration>
When the client terminal 101 designates the sensor 103 and performs group registration, the client terminal 101 designates the identifier of the target sensor 103. At that time, a value indicating that it is a registration instruction from the client terminal 101 is set in the command type 403 of FIG. 4, and the sensor 103 side receives the command according to the procedure of the second embodiment of the present invention. Registration is possible by issuing packets of group registration commands 400b and 400c from the lower level to the higher level node 102.

<Third Embodiment>
Next, FIG. 11 shows a group management method and nodes in a sensor network according to the third embodiment of the present invention. In the third embodiment, a group information registration deletion (leaving) function is added to the first embodiment. FIG. 11 shows a mechanism for removing the sensor Y under the node H from the group # 1, and it is assumed that the sensor Y has been removed.
(1) First, when the node H issues a command for the sensor Y, an error occurs because the sensor Y is not connected, and the node H detects this error.
(2) The node H determines that the sensor Y does not exist, and deletes the registration information regarding the sensor Y from the destination management table 205 of the own node H.
(3) Subsequently, when there is no registration related to the group # 1 to which the sensor Y belongs in the destination management table 205, the node H itself is an upper node in order to leave the group # 1. A packet “leave group” is issued to node D.
(4) The node D receives the signal and deletes the correspondence information between the group # 1 and the node H from the destination management table 205 in the node D. As a result of the deletion, the registration (node I) regarding the group # 1 still exists in the node D, so the leave command from the group # 1 is not transmitted to the node A, which is the upper node.

  The group management device in the sensor network of the third embodiment has means for detecting that the command to the lower node has an error in the packet distribution unit 203 in FIG. 8 having the configuration of the second embodiment. In addition, a means for analyzing the packet contents and determining whether the signal is a group leaving signal is added to the destination update unit 601. In the case of an error or group leaving signal, the correspondence between the corresponding group and the node or sensor from the destination management table 205 is added. A means for deleting information is added, and the command transmission determination unit 602 checks whether there is no deleted group in the destination management table 205, and determines whether it is necessary to leave the group of the own node with respect to the upper node. And a packet for leaving the group when the packet construction unit 206 determines that it is necessary. We are adding a means for generating a.

  FIG. 12 shows the structure of group leaving IP packets 400d and 400e. FIG. 12A shows a structure when the sensor 103 is detached from the group, and FIG. 12B shows a structure when the node 102 is detached from the group. A packet 400d shown in FIG. 12A includes an IP header 401, a TCP / UDP header 402, a command type 901 indicating “group leaving” as the use of the IP packet, and a sensor or node to be removed. It consists of a group name 404 that specifies the identifier of the group to which it belongs and a sensor name 702 that specifies the identifier of the sensor to be removed. Also, the packet 400e shown in FIG. 12B is composed of a node name 703 that specifies the identifier of the node to be removed instead of the sensor name 702, and the other fields are the same as in FIG. 12A. .

  The operation of the group management method and nodes in the sensor network configured as described above will be described with reference to FIG. First, when the node 102 detects that the command issued to the lower-level node 102 or the sensor 103 has an error (step S301), the node 102 determines based on the identifier of the node 102 or the sensor 103 in error. The destination management table 205 is referred to, the identifier of the corresponding group is acquired, and the corresponding record is deleted (step S302).

  When the error detection is triggered, there is a possibility that the sensor 102 or the node 103 that has caused the error may belong to a plurality of groups, so that the corresponding group is identified from the destination management table 205. Based on the group identifier 301 acquired above, the destination management table 205 of the own node 102 is referred to, and the presence or absence of a matching record is confirmed (step S303). If it exists, the process ends. If not, the own node 102 will also leave the group, so the group leaving command packets 400d and 400e for the upper node 102 are generated (step S304) and transmitted to the upper node 102 (step S104). The upper node 102 is triggered by the group leaving commands 400d and 400e, and deletes only the correspondence information between the group name 404 and the node name 703 included in the commands 400d and 400e. Other processes are the same as described above.

  As described above, according to the group management method and node in the sensor network of the third exemplary embodiment of the present invention, after detecting an error at the time of command transmission, the destination node 102 that has an error from the destination management table 205 is detected. Alternatively, a means for deleting the correspondence information with the group for the sensor 103 is provided, and when the information belonging to the group disappears from the destination management table 205, the commands 400d and 400e for leaving the group are also issued to the upper node 102. By doing so, it becomes possible to leave the node 102 and the sensor 103 from the group with the minimum necessary traffic without monitoring the sequential state.

<Other examples of leaving the group>
When the client terminal 101 designates the sensor 103 to leave the group, the client terminal 101 designates the sensor 103 identifier. At that time, a value indicating “instruction to leave from the client” is set in the command type 403 of the packet 400a in FIG. 4, and the sensor 103 side receives the command to trigger the third embodiment of the present invention. By issuing packets 400d and 400e of group leaving commands from the lower level to the upper node 102 by the procedure of the form, it is possible to leave.

  Note that each functional block used in the description of the above embodiment is typically realized as an LSI which is an integrated circuit. These may be individually made into one chip, or may be made into one chip so as to include a part or all of them. The name used here is LSI, but it may also be called IC, system LSI, super LSI, or ultra LSI depending on the degree of integration. Further, the method of circuit integration is not limited to LSI's, and implementation using dedicated circuitry or general purpose processors is also possible. An FPGA (Field Programmable Gate Array) that can be programmed after manufacturing the LSI, or a reconfigurable processor that can reconfigure the connection and setting of circuit cells inside the LSI may be used. Further, if integrated circuit technology comes out to replace LSI's as a result of the advancement of semiconductor technology or a derivative other technology, it is naturally also possible to carry out function block integration using this technology. For example, biotechnology can be applied.

  The present invention does not transmit a command to a node that does not have an information providing terminal of the group, and therefore has an effect that traffic can be suppressed, and for a hierarchical sensor network in which a large number of sensors are connected. Useful.

The block diagram which shows the group management method and node in the 1st Embodiment of this invention The block diagram which shows the group management apparatus in the node in the 1st Embodiment of this invention FIG. 3 is an explanatory diagram illustrating a configuration of a destination management table in FIG. 2. (A) When the target is a node, (b) When the target is a sensor Configuration diagram of sensor control packet according to the first embodiment of the present invention The flowchart for demonstrating the group management method and node processing in the 1st Embodiment of this invention Explanatory diagram showing traffic volume when issuing conventional sensor control commands The block diagram which shows the group management method and node in the 2nd Embodiment of this invention The block diagram which shows the group management apparatus in the node in the 2nd Embodiment of this invention The block diagram of the group registration packet in the 2nd Embodiment of this invention. (A) During sensor registration, (b) During node registration The flowchart for demonstrating the group management method and node processing in the 2nd Embodiment of this invention The block diagram which shows the group management method and node in the 3rd Embodiment of this invention The block diagram of the group leaving packet in the 3rd Embodiment of this invention. (A) When sensor leaves, (b) When node leaves The flowchart for demonstrating the group management method and node processing in the 3rd Embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 101 Client terminal 102 Node 103 Sensor 201 Group management apparatus 202 Packet receiving part 203 Packet distribution part 204 Destination acquisition part 205 Destination management table 206 Packet construction part 207 Packet transmission part 601 Destination update part 602 Command transmission determination part

Claims (7)

In a group management method in which a client terminal groups and manages a plurality of information providing terminals in a system that collects information provided by a plurality of information providing terminals via a plurality of hierarchical nodes,
Each of the plurality of nodes corresponds to a group identifier indicating a group of the information providing terminals, a node identifier indicating a node of a hierarchy one level lower belonging to the group, or an information providing terminal identifier indicating the information providing terminal. Storing in a table;
Transmitting a group designation command including the group identifier from the client terminal to the highest node;
It is determined whether or not the highest-order node and the lower-order node that has received the group designation command store the group identifier in the group designation command in the table. Transmitting the group designation command to a node in the lower hierarchy corresponding to a group identifier or to the information providing terminal;
A group management method characterized by comprising. In a group management method in which a client terminal groups and manages a plurality of information providing terminals in a system that collects information provided by a plurality of information providing terminals via a plurality of hierarchical nodes,
The lowermost node connected to the information providing terminal registers a correspondence relationship between a group identifier indicating the group of the information providing terminals and an information providing terminal identifier indicating the information providing terminal in a table, and the information providing terminal Sending a group registration command including the group identifier of the node and the node identifier of the own node to a node in the upper hierarchy;
The node that has received the group registration command registers the correspondence between the group identifier and the node identifier in the group registration command in the table, and the group identifier only when the registered group identifier is a new registration. And a step of transmitting a group registration command including a node identifier indicating the own node to a node of a higher hierarchy,
Each of the plurality of nodes corresponds to a group identifier indicating a group of the information providing terminals, a node identifier indicating a node of a hierarchy one level lower belonging to the group, or an information providing terminal identifier indicating the information providing terminal. A group management method characterized by being registered in the table. In a group management method in which a client terminal groups and manages a plurality of information providing terminals in a system that collects information provided by a plurality of information providing terminals via a plurality of hierarchical nodes,
Each of the plurality of nodes corresponds to a group identifier indicating a group of the information providing terminals, a node identifier indicating a node of a hierarchy one level lower belonging to the group, or an information providing terminal identifier indicating the information providing terminal. Storing in a table;
The lowermost node connected to the information providing terminal deletes the correspondence between the group identifier of the information providing terminal and the information providing terminal identifier from the table, and indicates the group identifier of the information providing terminal and the own node. Sending a group leaving command including a node identifier to a node in the upper hierarchy;
Only when the node that has received the group leave command deletes the correspondence between the group identifier and the node identifier in the group leave command from the table and does not register the deleted group identifier in the table, Transmitting a group leaving command including the group identifier and a node identifier indicating its own node to a node in the next higher hierarchy;
A group management method characterized by comprising. The node in the network in which the client terminal groups and manages the plurality of information providing terminals in a system that collects information provided by the plurality of information providing terminals via a plurality of hierarchical nodes,
A storage unit that stores a group identifier indicating the group of the information providing terminals, a node identifier indicating a node of the next lower hierarchy belonging to the group, or an information providing terminal identifier indicating the information providing terminal;
When a group designation command including the group identifier is transmitted from the client terminal to the highest node, it is determined whether or not the group identifier in the group designation command is stored in the storage means, and stored. Means for transmitting the group designation command to a node in the next lower hierarchy corresponding to the group identifier or the information providing terminal only when
A prepared node. The node in the network in which the client terminal groups and manages the plurality of information providing terminals in a system that collects information provided by the plurality of information providing terminals via a plurality of hierarchical nodes,
A storage unit that stores a group identifier indicating the group of the information providing terminals, a node identifier indicating a node of the next lower hierarchy belonging to the group, or an information providing terminal identifier indicating the information providing terminal;
In the case of the lowest layer node connected to the information providing terminal, the correspondence relationship between the group identifier of the information providing terminal and the information providing terminal identifier is registered in the storage means, and the group identifier of the information providing terminal Means for transmitting a group registration command including a node identifier of a node to a node of a higher hierarchy;
When the group registration command is received, the correspondence between the group identifier and the node identifier in the group registration command is registered in the storage unit, and only when the registered group identifier is a new registration, the group A means for transmitting a group registration command including an identifier and a node identifier indicating its own node to a node in the upper hierarchy;
A prepared node. The node in the network in which the client terminal groups and manages the plurality of information providing terminals in a system that collects information provided by the plurality of information providing terminals via a plurality of hierarchical nodes,
A storage unit that stores a group identifier indicating the group of the information providing terminals, a node identifier indicating a node of the next lower hierarchy belonging to the group, or an information providing terminal identifier indicating the information providing terminal;
In the case of the lowest layer node connected to the information providing terminal, the correspondence relationship between the group identifier of the information providing terminal and the information providing terminal identifier is deleted from the storage unit, and the group identifier of the information providing terminal Means for transmitting a group leaving command including a node identifier indicating a node to a node in the upper hierarchy;
When the group leaving command is received, the correspondence between the group identifier and the node identifier in the group leaving command is deleted from the storage unit, and the deleted group identifier is not registered in the storage unit Only, a means for transmitting a group leaving command including the group identifier and a node identifier indicating the own node to a node in the upper hierarchy,
A prepared node.   When the lowest layer node connected to the information providing terminal detects a reception error in response to the command sent to the information providing terminal, or when the group leaving command is received from the client terminal The node according to claim 6, wherein the node transmits to the node.