JP2005333238A - Path management device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a path management device capable of minimizing a path information quantity and improving efficiency in data integration. <P>SOLUTION: To solve the problem, the path management device for managing path information to a specific wireless communication device requesting the information includes a communication means for making wireless communication with other peripheral wireless communication devices, a path information managing means for managing the shortest path of the path information to the specific wireless communication device which has requested the information each time an information request from the specific device is received, a data creating means for determining the contents of the received information request and creating requested data in response to the request, and a communication control means for updating the number of hops included in the received information request to cause the other peripheral communication devices to transmit for transmitting the requested data created by the data creating means. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a path management apparatus, and can be applied to a path management apparatus that efficiently integrates data in a network in which a plurality of nodes frequently transfer data to a specific node, for example.

  For example, in a wireless network system, when transferring certain information from a certain wireless communication device (hereinafter referred to as “node”) to a destination node, the packet is forwarded to at least one node and forwarded to the destination node. There are multi-hop wireless communication systems. In such a multi-hop wireless communication system, it is necessary to construct and maintain a route from the transmission source node to the transmission destination node.

  Conventionally, there is a DSR (Dynamic Source Routing) method as shown in Non-Patent Document 1 as a route construction / maintenance method.

  In this DSR method, first, a transmission source node broadcasts a route request packet (RREQ: Route Request Packet) including a transmission source address and a transmission destination address and a unique identification number that makes it possible to identify a route request. connect.

  The node that has received the route request packet (RREQ) refers to, for example, the routing table of the receiving node, checks the route to the destination node, and knows the route to the destination node. Based on the above, the address of the next transfer destination node is added and transferred, and when the route to the destination node is not known, the address of the receiving node is added and transferred.

  Each relay node repeatedly performs the data transfer process described above, so that the route request packet reaches the transmission destination node.

  When the route request packet reaches the destination node, the destination node generates a response packet (RREP: Route REPly) and forwards the response packet back to the route of the route request packet to the source node.

In this way, a bidirectional path from the transmission source node to the transmission destination node can be established.
"Dynamic Source Routing in Ad-hoc wireless Networks", D.C. B. Johnson, D.C. Amaltz, Mobile Computing, pp. 153-181, 1996.

  Incidentally, in a multi-hop wireless network system, a specific node may collect information possessed by a large number of nodes.

  In this case, many-to-one communication between a large number of nodes and a specific node is performed. When the one-to-one communication path construction / maintenance method as described above is applied as it is, the number of control packets received by each relay node is as follows. As a result, data integration was not performed efficiently.

  In other words, in the case of existing route control, the shortest route between the source and destination of one-to-one communication can be constructed, but in many-to-one communication, the route of one-to-one communication is overlapped, so efficient data The integration was not possible, and the amount of route information required for the node was enormous with the number of nodes.

  In addition, when there are a plurality of routes having the same length, the selection is random selection or fixed selection, and only a specific route (one) is selected.

  Therefore, in a large-scale network that mainly collects data to a specific node and has few accesses between other nodes, simple route construction processing, minimization of route information, and dynamic route evaluation value by feedback of data transfer status Therefore, there is a need for a path management device that enables data collection with a minimum waiting delay that enables high data integration.

  In order to solve this problem, the route management device of the present invention is a route management device that manages route information to a specific wireless communication device that requests information, and a communication unit that performs wireless communication with other peripheral wireless communication devices. Each time an information request for a specific wireless communication device is received, route information management means for managing the shortest route information of the route information to the specific wireless communication device that has requested the information request, and the content of the received information request are determined. Data creation means for creating request data in response to an information request, update the number of hops included in the received information request, send it to other peripheral wireless communication devices, and send request data created by the data creation means And a communication control means.

  According to the present invention, it is possible to collect data with a simple route construction process, minimization of route information amount, a dynamic route evaluation value based on feedback of data transfer status, and a minimum waiting delay enabling high data integration. it can.

(A) Embodiment Hereinafter, a case where the route management apparatus of the present invention is applied to a wireless communication apparatus of a wireless network that employs a multi-hop wireless communication system will be described.

(A-1) Configuration of Embodiment FIG. 1 is a diagram for explaining a network configuration of this embodiment. FIG. 1A is a diagram for explaining an example of a physical arrangement of a plurality of nodes and an image of a communicable range of each node, and FIG. It is a figure explaining the group (group) which consists of connection relations.

  In FIG. 1A, the wireless network 1 according to the present embodiment includes one sink node (hereinafter referred to as a sink) 20 and six general nodes (hereinafter referred to as nodes) N11 to N32. Of course, the physical arrangement of the wireless network 1 and the number of nodes are not limited thereto.

  As shown in FIG. 1B, the nodes N11 and N12 are located within a certain distance from the sink 20, and the nodes N21 and N22 are located within a certain distance from the nodes N11 and N12. Is located within a certain distance from the nodes N21 and N22. Nodes N11 and N12 are referred to as a group N1, nodes N21 and N22 are referred to as a group N2, and nodes N31 and N32 are referred to as a group N3. Furthermore, the sink 20 is defined as the most downstream, and the group that is separated from the sink 20 is indicated as the upstream.

  The sink 20 is a node (communication device) connectable to an external network (not shown) and the wireless network 1. The sink 20 can execute various functions realized by nodes N11 to N32, which will be described later. Unlike the nodes N11 to N32, the sink 20 has an information request command creation / transmission function that requests data to be collected by the sink 20. Is provided. As a result, it is possible to notify each of the nodes N11 to N32 of the information content collected by the sink 20 and the requested node information.

  The nodes N11 to N32 are communication devices that transmit and receive transmission frames to and from other nodes that can perform wireless communication via a wireless link. Also, the nodes N11 to N32 are based on the received transmission frame, based on the registration / update / addition function of the management information of the route selection table (routing table) possessed by the nodes N11 to N32, the transmission frame relay function, and the measurement data Data command creation / transmission function, data integration function for data included in transmission frame, relay function for transmission frame including data, report command creation / transmission function for reporting actual information of transmission frame including data to upstream node, etc. Is provided.

  FIG. 2 is a configuration block diagram showing an internal configuration of the nodes N11 to N32. As illustrated in FIG. 2, the nodes N11 to N32 include at least a communication port 11, a data storage unit 12, a cache 13, a command analysis unit 14, a comparison search unit 15, a timer 16, a calculation unit 17, a sensor unit 18, and the like.

  The communication port 11 is a communication unit that wirelessly communicates transmission frames. The communication port 11 gives the received transmission frame to the data storage unit 12 for storage. The communication port 11 is assigned a predetermined port number, and assigns the port number to the frame header of the received transmission frame.

  The data storage unit 12 temporarily stores transmission frames received by the communication port 11. The data storage unit 12 temporarily stores commands, packets, and the like created by the instruction analysis unit 14 described later.

  The cache 13 temporarily stores a routing table (Routng Table) 13a for managing received transmission frame information.

  Here, an example of management items of the routing table stored in the cache 13 will be described with reference to FIG.

  As shown in FIG. 3, examples of management items of the routing table 13a include a sink name (Sink Name), the number of hops (Hop Count), a network size (NS: Network Size), node performance information (Node Result), and downstream nodes. Information (Lower Node) 1 to 3 and downstream node data transfer performance information (Status) 1 to 3.

  In FIG. 3, the number of downstream nodes and data transfer record information management numbers is not particularly limited, and can be increased or decreased according to the transfer status of the transmission frame.

  The sink name (Sink Name) indicates the name of the sink that collects information. The number of hops (Hop Count) indicates the number of times a transmission frame is transferred between nodes. The network size (NS) indicates the size of the network based on the number of hops.

  The node result information (Node Result) is the number of data integration operations of the node, and the number of received data (RDN: Receive Data Number) counted every time the data integration operation is performed on the data included in the received transmission frame. , And a transmission data number (TDN) that is counted each time a transmission frame in which data is integrated is transmitted.

  Downstream nodes (Lower Nodes) 1 to 3 are information regarding downstream nodes that have transferred the transmission frame, and have a downstream node address (Node Address) and a port number of the communication port 11.

  Data transfer record information (Status) 1 to 3 is data transfer record information of the downstream nodes 1 to 3, and is the number of received data (RDN), the number of transmitted data (TDN), and the total number of transmitted data (TTDN: Total Transmit Data Number). ).

  The command analysis unit 14 determines the information type of the received packet based on the packet type (Packet Type) of the received packet stored in the data storage unit 12, and performs a predetermined command analysis process according to the information type of the received packet. To do.

  Here, the configuration of the transmission frame and the packet will be described with reference to FIG. In FIG. 4, the transmission frame is composed of a frame header part and a packet part.

  The frame header part has a transmission source address (Source Address) and a transmission destination address (Destination Address), and the packet part has a packet header part and a packet payload part.

  The packet header portion has a packet type (Packet Type) indicating the packet type of the packet payload portion, a packet transmission source node name (Source Name), a packet transmission destination name (Destination Name), and a hop count (Hop Count). .

  Further, the packet payload portion is a portion including a command generated by the sink 20 or the nodes N11 to N32.

  In the present embodiment, the commands generated by the sink 20 or the nodes N11 to N32 include an information request command (Query Command), a data command (Data Command), and a report command (Report Command).

  The information request command is a command created by the sink 20 when collecting information. The data command is a command created by the nodes N11 to N32 when providing measurement data. Further, the report command is a command created when notifying the adjacent upstream node of the transfer status of the transmission frame.

  The command analysis unit 14 confirms the packet type of the received packet for the received transmission frame having the above-described configuration, and if it determines that the packet type is an information request command, it performs reception processing and relay processing of the received packet. .

  When determining that the request is an information request command based on the packet type, the command analysis unit 14 causes the comparison search unit 15 to compare whether or not there is a sync name in the routing table 13a that matches the transmission source name of the received packet. If the transmission source name of the received packet is not registered in the routing table 13a, the command analysis unit 14 registers the transmission source name, the hop count, the transmission destination address, and the communication port number of the received packet in the routing table. Is. In addition, when registered, the instruction analysis unit 14 compares the hop count of the received packet with the hop count already managed in the routing table 13a, and the management information of the routing table 13a is determined according to the comparison result. Update / addition processing or received packet discard processing is performed.

  Further, the instruction analysis unit 14 increases the number of hops by “1” for the received information request command packet, gives the packet to the communication port 11, adds a broadcast address to the transmission destination address, and performs relay processing by broadcast. To control.

  Further, the instruction analysis unit 14 determines whether or not the own nodes N11 to N32 correspond to the nodes that request information from the sink 20 based on the content of the information request command, and creates a data command.

  Here, the configuration of the information request command will be described with reference to FIG. The information request command is a command created in the sink 20 and has a sink name (Sink Name), a request identification number (Query Number), an information request node name (Target Name), and a request information type (Data Class). Consists of.

  The sink name is the name of the sink 20 that collects information. The request identification number is a unique identification number for identifying an information request (Query).

  The information requesting node names are names of the nodes N11 to N32 from which the sink 20 requests information provision. The sink 20 can designate a plurality of nodes that request information provision, and can designate all nodes (for example, “ALL”).

  The request information type is data type information that the sink 20 desires to collect. For example, in this embodiment, “maximum value and average value of temperature measured every 10 minutes” is set as the request information type. Other than this, for example, data that can be measured by each of the nodes N11 to N32 can be widely applied. For example, data such as humidity, pressure, concentration, image, and sound can be collected.

  Next, the instruction analysis unit 14 determines whether or not the own node is an information request node from the information request command having the above configuration. If the own node is included, the command analysis unit 14 determines the data indicated in the request information type as the sensor unit. 18, a data command having the measurement result is created, and the data command is temporarily stored in the data storage unit 12. In addition, when the own node is not included, the instruction analysis unit 14 creates a data command that does not include the measurement result by the sensor unit 18 and temporarily stores the data command in the data storage unit 12. .

  Here, the configuration of the data command created by the instruction analysis unit 14 will be described with reference to FIG. As shown in FIG. 6, the data command includes a sink name (Sink Name), a request identification number (Query Number), a network scale (Network Scale), an integration number (Aggregation), and a data value (Data Vave).

  The sink name is the name of the sink 20 that collects information. The request identification number is a unique identification number for identifying an information request (Query).

  The network scale is the size of the wireless network 1 based on the number of hops. The number of integration is the number of data integration. The data value is a data value measured by the sensor unit 18.

  Next, when transmitting the packet having the created data command, the command analysis unit 14 causes the comparison search unit 15 to search the management information corresponding to the sync name of the data command from the routing table 13a, and from the search result. The downstream node and its data transfer record information are read, the downstream node is selected based on the downstream node and the data transfer record information, and the relay node for transmitting the data command transmission frame is determined. Further, the instruction analysis unit 14 gives a packet of the data command to the communication port 11 and causes the selected downstream node address to be transmitted as a transmission destination address of the transmission frame and the address of the own node to be transmitted by unicast as the transmission source address. It is.

  Here, a method for determining a relay node by the instruction analysis unit 15 will be described. When there are a plurality of downstream nodes read by the instruction analysis unit 15 from the routing table 13a, the downstream node having a relatively high data integration degree is evaluated by evaluating the data integration degree by the downstream node based on the data transfer result information of the routing table 13a. Is selected and the relay node is determined.

  As an evaluation method of the data integration degree of the downstream node, for example, RDN and TDN are read from the data transfer performance information of each downstream node read from the routing table 13a, and (TDN ÷ RDN) is calculated, and the calculation result is small. A downstream node is selected as a relay node. As a result, it is possible to select a downstream node with a high degree of data integration among a plurality of downstream nodes, and to increase the degree of integration (aggregation) of data commands created in the downstream node. Efficient communication can be made possible.

  Also, for example, RDN, TDN, and TTDN are read from the data transfer record information, (TDN ÷ RDN × TTDN) is calculated, and a downstream node having a small calculation result is selected as a relay node. As a result, among the plurality of downstream nodes, the degree of data integration is high to some extent, and it is possible to select a downstream node that does not concentrate on the long-term data to a specific node, thereby reducing overall power consumption of many-to-one communication. It becomes possible.

  Note that the downstream node selection method by the instruction analysis unit 14 may perform different calculations depending on the positions of the nodes N11 to N32.

  If the command analysis unit 14 determines that the received packet is a data command based on the packet type of the received packet stored in the data storage unit 12, the instruction analysis unit 14 sends the destination name of the received packet to the comparison search unit 15. By comparing whether or not the sink name in the routing table 13a matches, it is searched whether or not the transfer route related to the sink 20 is registered in the routing table 13a.

  When the command analysis unit 14 determines that the transfer path related to the sink 20 is registered in the routing table 13 a, the command analysis unit 14 stores the content of the data command of the received packet in the comparison search unit 15 and the data storage unit 12. Whether the sink name matches the request identification number is compared based on the contents of the data command created by the node in the past.

  Further, when the sync name and the request identification number match, the instruction analysis unit 14 performs an integration process on the data value of the data command of the received packet and the data value of the data command created in the past, and the integration process A data command is created by updating the result as a new data value.

  Here, when updating the data command by the instruction analysis unit 14, for the network scale, write the data scale of the received packet or the network scale with the larger number of hops among the data commands created in the past, The data integration value is increased by “1” and updated.

  When the request information type of the information request command requires statistical processing, the instruction analysis unit 14 writes the result of statistical processing performed by the calculation unit 17 into the data value of the data command.

  Further, when performing the data command integration processing, the instruction analysis unit 14 adds “1” to the RDN of the node integration performance (Node Result) in the routing table 13a and updates it.

  The instruction analysis unit 14 creates a packet based on the updated data command, gives the created packet to the communication port 11, sets the address of the selected downstream node as the transmission destination address of the transmission frame, and sets the address of the own node. The transmission source address is transmitted by unicast.

  Here, the packet is created by the instruction analysis unit 14 using the transmission destination name as the sink name, the transmission source name as the node name having the maximum number of hops, and the packet type as the data command.

  Further, the selection method of the downstream node described above can be applied to the selection method of the downstream node that transmits the transmission frame.

  In addition, when transmitting the transmission frame including the updated data command, the command analysis unit 14 adds “1” to the TDN of the node integration result (Node Result) in the routing table 13a and updates it.

  When the command analysis unit 14 transmits / receives a transmission frame including a data command, the command analysis unit 14 creates a report command based on the transmitted / received transmission frame, its own node name, and the routing table 13a, and transmits the transmission frame including the report command to an adjacent upstream node To communicate with.

  Here, the structure of the report command will be described with reference to FIG. As shown in FIG. 7, the report command includes a sink name (Sink Name), a request identification number (Query Number), a node name (Node Name), and a data transfer result (Status).

  The node name is its own node name. The data transfer result is the node integration result (Node Result) of the routing table 13a.

  The command analysis unit 14 creates a packet based on the created report command, gives the packet to the communication port 11, and performs wireless communication by broadcast.

  Further, the command analysis unit 14 resets the node integration result (Node Result) of the routing table 13a when a transmission frame including a report command is transmitted by broadcast.

  If the command analysis unit 14 determines that the received packet is a report command based on the packet type of the received packet stored in the data storage unit 12, the instruction analysis unit 14 sends the destination name of the received packet to the comparison search unit 15. A comparison is made as to whether or not the sink name in the routing table 13a matches, and a search is made as to whether or not the transmission destination name is registered in the routing table 13a.

  Further, when the transmission destination name is registered in the routing table 13a, the instruction analysis unit 14 determines that the transmission source address of the transmission frame matches the address of the downstream node of the routing table 13a. It is made to search whether there exists.

  Further, when the transmission destination address of the transmission frame is registered in the routing table 13a as the address of the downstream node, the command analysis unit 14 reads information (RDN, TDN) included in the report command and reads the read information. (RDN, TDN) is updated to the data transfer result information of the corresponding downstream node in the routing table 13a. Note that the TTDN of the routing table 13a can be updated by accumulating the TDN values before the update.

  The comparison search unit 15 receives the instruction from the instruction analysis unit 14, reads the transmission frame stored in the data storage unit 12, and compares / searches the management information corresponding to the information content of the transmission frame from the routing table 13a. To do.

  When receiving a transmission frame including an information request command, the timer 16 measures the transmission waiting time (TW) of the transmission frame including the data command according to an instruction from the command analysis unit 14. When the transmission standby time (TW) has elapsed, the timer 16 notifies the instruction analysis unit 14 that it has elapsed.

  The calculation unit 17 performs statistical processing of a transmission standby time (TW) and a data value to be integrated according to an instruction from the instruction analysis unit 14.

  The calculation method of the transmission waiting time (TW) by the calculation unit 17 is, for example, from the initial value of the network size (NS: variable indicating the maximum hop size of the wireless network 1) managed by the routing table 13a. It is calculated by multiplying the value obtained by subtracting the number of hops by the initial value of unit time (W) (see the following formula (1)).

TW = (NS−hop count) × W (1)
Note that the initial value of the unit time (W) is determined by the specifications and performance of the communication method applied to the wireless network 1.

  Further, the data statistical processing by the calculation unit 17 is processed according to the request information type of the information request command. For example, when requesting an average value of the data values integrated by the request information type, the calculation unit 17 sets the integrated data A value averaging process is performed.

  The sensor unit 18 is a measuring unit that measures a data value.

  Next, the internal configuration of the sink 20 will be described with reference to the configuration block diagram of FIG.

  As shown in FIG. 8, the sink 20 includes a communication port 21, a data storage unit 22, a cache 23, an instruction generation unit 24, a comparison search unit 25, a timer 26, a calculation unit 27. At least an external communication port 29 is provided.

  The sink 20 can also function as a general node, and the internal configuration of the sink 20 can correspond to the internal configuration of the nodes N11 to N32.

  That is, the functions of the communication port 21, the data storage unit 22, the cache 23, the comparison search unit 25, the timer 26, and the calculation unit 27 of the sink 20 are the same as the communication port 11, the data storage unit 12, the cache 13, and the comparison of the nodes N11 to N32. This corresponds to the functions of the search unit 15, timer 16, and calculation unit 17.

  Therefore, in the following, the functional description of the specific configuration of the sink 20 will be described in detail, and the detailed functional description of the configuration corresponding to the nodes N11 to N32 will be omitted.

  The instruction generator 24 creates an information request command when collecting information. The instruction generation unit 24 creates a packet based on the created information request command, gives the created packet to the communication port 21, sets the transmission source address as the address of the sink 20, and sets the transmission destination address as the broadcast address. It is given to allow wireless communication by broadcast.

  The external communication port 29 is a communication port for an external network (not shown).

(A-2) Operation of Embodiment FIG. 9 is a communication sequence diagram between the sink 20 and the nodes N11 to N32 in the wireless network 1 of the present embodiment. Hereinafter, the route construction operation will be described with reference to the sequence diagram shown in FIG. 9 as appropriate.

(A-2-1) Information Request Packet Transmission Process FIG. 10 is a flowchart illustrating a processing operation for transmitting a transmission frame including an information request command by the sink 20.

  As shown in FIG. 10, when the sink 20 collects information, the instruction generation unit 24 generates an information request command (Query Command) indicating a node requesting information and a request information type in the sink 20 (S1). ).

  At this time, the generated information request command includes the name of the sink 20 (Sink Name) as a node name for collecting information, a unique request identification number (Query Number) for identifying the information request command, and the name of the node requesting information. (Target Name) and a request information type (Data Class) indicating the information content to be collected are written by the instruction generation unit 24.

  In this embodiment, the contents of data to be collected are “temperature every 10 minutes” and “maximum value and average value of this temperature”, and information indicating that is written in the request information type.

  When the information request command is generated, the instruction generator 24 adds a predetermined packet header to the generated information request command to form a packet (hereinafter referred to as REQ) (S2).

  At this time, the packet header indicates that the packet type (Packet Type) is an information request command. Further, the name of the sink 20 is indicated in the transmission source name (Source Name), and the special name for flooding is indicated in the transmission destination name (Destination Name).

  Further, “1” is written in the hop count (Hop Count) of the packet header.

  The packet formed in this way is given from the command generation unit 24 to the communication port 21, and a transmission frame to which a frame header is attached by the communication port (hereinafter, this transmission frame is called Query) is transmitted from the communication port 21 to the wireless link. (S3).

  At this time, the address of the sink 20 is indicated in the transmission source address (Source Address) of the frame header, and the broadcast address is indicated in the transmission destination address (Destination Address).

  In this way, the query is broadcast to the adjacent upstream nodes N11 and N12.

(A-2-2) REQ Reception Processing FIG. 11 is a flowchart for explaining the reception operation of the nodes N11 to N32 that receives the Query transmitted from the sink 20.

  As shown in FIG. 11, the Query transmitted from the sink 20 is received by all the nodes N11 and N12 of the N1 group (S4).

  At this time, the transmission frame is received when the frame header is confirmed by the communication ports 11 of the nodes N11 and N12, and the transmission destination address is a broadcast address.

  When the query is received by each of the nodes N11 and N12 of the N1 group, the query is given from the communication port 11 of each node 11 and N12 to the data storage unit 12 and stored (S5).

  At this time, the frame header is stored in the data storage unit 12 after the port number of the communication port 11 is given.

  When the query is stored in the data storage unit 22, the packet type of the packet header is read by the instruction analysis unit 14, and the type of the packet is confirmed (S6). As a result, it is determined that the received packet is a REQ.

  When the command analysis unit 14 determines that the received packet is a REQ, the command analysis unit 14 performs a routing table creation process and a query relay process based on information included in the REQ (S7).

  It should be noted that similar REQ reception processing is also performed in upstream nodes N21 to N32 subsequent to the N2 group.

(A-2-2-1) Routing Table Creation Processing FIG. 12 is a flowchart showing processing for registering, updating, adding, etc. a REQ transmission path with reference to the routing table 13a in the nodes N11 to N32 that have received the query. It is.

  When the command analysis unit 14 determines that the received packet is REQ, the comparison / search unit 15 determines whether the REQ transmission path is registered in the routing table 13a of the cache 13 (S8).

The comparison search unit 15 compares the transmission source name of the REQ and the sink name of the routing table 13a, and searches for a match (S9).
If the transmission source name of the REQ and the sink name of the routing table 13a do not match, the command analysis unit 14 determines that the transmission path of the REQ is not registered in the routing table 13a, and the command analysis unit 14 transmits the REQ. A route is newly registered in the routing table 13a (S15).

  At this time, the sync name and the hop count in the packet header of the REQ are registered in the sync name and the hop count of the routing table 13a, and the transmission source address and port number in the Query frame header are set to the downstream node of the routing table 13a. Registered in node address and port number.

  An initial value (for example, “5”) is registered in the network size of the routing table 13a. The initial value of the network size is a variable determined from the estimation of the network size to be used, and the network size is a variable that can be updated based on the maximum number of hops.

  On the other hand, if the transmission source name of the REQ matches the sink name of the routing table 13a, the instruction analysis unit 14 determines that the transmission path of the REQ is registered in the routing table 13a. The size of the registered number of hops and the number of hops in the packet header of the received REQ are compared by the comparison / search unit 15 (S10).

  In S10, when the number of hops of the received REQ is smaller than the number of hops of the routing table 13a, the received REQ reaches the node with a shorter path length than the registered route of the routing table 13a. The downstream node 1 and the hop count are updated to the frame header transmission source address and port number and the hop count of the reception REQ by the command analysis processing 14 (S12).

  If the hop count of the received REQ and the hop count of the routing table 13a are the same in S10, whether or not the transmission source address of the Query frame header matches the address of the downstream node 1 of the routing table 13a. Are compared by the comparison search unit 15 (S11).

  When the comparison search unit 14 does not match the transmission source address of the frame header with the address of the downstream node 1 of the routing table 13a, that is, the redundant path has the same hop count and different routes. The address and port number are added to the downstream node 2 of the routing table 13a (S13).

Further, when the hop count of the received REQ is larger than the hop count of the routing table 13a in S10, or the hop count of the received REQ and the routing table 13a is the same in S11 and the transmission source address and routing of the frame header are the same. When the address of the downstream node 1 in the table 13a matches, the received REQ is discarded by the instruction analysis unit 14 (S14).
As a result, each of the nodes N11 to N32 can record only the route received by the shortest route from the sink 20 in the routing table 13a, so that the table size can be reduced.

(A-2-2-2) REQ Relay Processing FIG. 13 is a flowchart showing REQ relay processing.

  As illustrated in FIG. 13, when new registration, update, and addition of the routing table 13 a are performed in each of the nodes N <b> 11 to N <b> 32, the instruction analysis unit 14 adds “1” to the hop count of the packet header of the received REQ. (S16).

  The REQ in which the hop count of the packet header is updated is given to the communication port 11, and in the communication port 11, the frame header in which the own node address is written in the transmission source address and the broadcast address is written in the transmission destination address is REQ. And transmitted (relayed) by broadcast (S17).

  The REQ reception process described above is performed in the same manner in the N2 group and the N3 group, and the query is transferred from the sink 20 to the N1, N2, and N3 groups to all the nodes in the wireless network 1, and is transmitted through the shortest path. The adjacent downstream node of the transferred packet is held in the routing table 13a.

  In addition, when there are a plurality of shortest paths for one Query, a plurality of paths are held, so that a redundant shortest path to the sink is held in the routing table 13a.

(A-2-3) Data Command Creation Processing Next, data command creation processing by the nodes N11 to N32 that have received the REQ will be described with reference to FIG.

  When the REQ is received (S18), the command analysis unit 14 sets the transmission waiting time (TW) in the timer 16 (S19).

  This transmission standby time (TW) is an interval at which each node relays transmission. When the transmission standby time elapses, a notification signal is given from the timer 16 to the command analysis unit 14, and the transmission frame is transmitted / relayed. Further, the data received within this time is integrated by the instruction analysis unit 14.

  The transmission waiting time (TW) is calculated by the calculation unit 17 according to an instruction from the instruction analysis unit 14, and the calculation method follows, for example, the above equation (1). As a result, as shown in FIG. 8, the downstream node can have a longer transmission waiting time (TW) than the upstream node, and the efficiency of data integration can be improved.

  Next, the information requesting node of the received information request command is confirmed by the instruction analysis unit 1, and it is confirmed whether the own node is included in the information requesting node (S20).

  When the information request node is confirmed, a data command is generated by the instruction analysis unit 14 as follows.

  First, when the own node is included in the information request node, the instruction analysis unit 14 confirms the request information type and creates a data command in which the data value measured by the sensor unit 18 is written (S21).

  At this time, as shown in FIG. 15A, the data command is written with the sink name and request identification number of the information request command. Further, the maximum hop count is read from the routing table 13a and written in the network scale.

  In this embodiment, the request information type is the maximum value and the average value of the temperature every 10 minutes, and data measured by other nodes (upstream nodes) is not received and data integration is not performed. Therefore, the data value measured in the sensor unit 18 is written in the data value, and “1” is written in the integration number.

  On the other hand, when the own node is included in the information request node, the command analysis unit 14 creates a data command in which no data value is written (S21).

  At this time, as shown in FIG. 15B, the data command is written with the sink name and request identification number of the information request command. Further, the maximum hop count is read from the routing table 13a and written in the network scale.

  Also, since the own node is not included in the information request node, 0 is written in the data value, and the data measured by the other node (upstream node) has not been received and data integration has not been performed. “0” is written in the number.

  As described above, the data command is generated by the instruction analysis unit 14 in the nodes N11 to N32 that have received the REQ. The created data command is stored in the data storage unit 12 during the transmission waiting time (TW).

(A-2-4) Data command transmission processing When a data command is created and the transmission standby time (TW) elapses, the created data command is packetized and transmitted as a transmission frame.

  FIG. 16 is a flowchart for explaining data command transmission processing.

  In FIG. 16, when the transmission standby time (TW) has not elapsed (S22), the command analysis unit 14 waits for transmission processing until the transmission standby time (TW) elapses.

  On the other hand, when the transmission standby time (TW) has elapsed, the command analysis unit 14 reads the data command from the data storage unit 12 (S23).

  When the data command is read from the data storage unit 12, a DATA packet is formed in the data command by the instruction analysis unit 14 (S24).

  At this time, in the DATA packet, the data command is inserted into the packet payload, the name of the sink 20 is inserted into the transmission destination name of the packet header, and the node name with the maximum hop count is inserted into the transmission source name of the packet header. Shown as a data command in the type.

  Next, the path information corresponding to the sync name of the data command is searched by the comparison search unit 15 from the routing table 13a (S25).

  When the path information is searched by the comparison search unit 15, the comparison search unit 15 reads the downstream node and the data transfer record information of the downstream node from the search information, and the downstream node is the DATA transmission destination node. (S26).

  At this time, when a plurality of downstream nodes exist in the search information from the routing table 13a, the instruction analysis unit 14 selects a node having a relatively high data integration degree.

  For example, as shown in FIG. 17, the transmission destination node selection method reads the data transfer performance information of each downstream node from the routing table 13a (S29), and based on the RDN and TDN of the data transfer performance information. Thus, (TDN ÷ RDN) of each downstream node is calculated by the calculation unit 17 (S30). The downstream node corresponding to the smallest one among these calculation results is selected as the transmission destination node (S31).

  Further, for example, based on the read RDN, TDN, and TTDN of each data transfer record information, (TDN / RDN × TTDN) of each downstream node is calculated by the calculation unit 17 (S30). The downstream node corresponding to the smallest one among these calculation results is selected as the transmission destination node (S31).

  In this way, the transmission destination node is determined and selected, and a DATA packet including a data command is given to the communication port 11. In the communication port 11, the address of the selected downstream node is written in the transmission destination address. A frame header in which the address of the own node is written in the address is added to the DATA packet and transmitted by unicast (S27).

  Each time DATA is sent out from the communication port 11, the command analysis unit 14 adds “1” to the TDN of the node performance information (Node Result) in the routing table 13a and updates it (S28).

  As in this embodiment, when the request information type is a continuous information request such as “temperature every 10 minutes”, the transmission waiting time (TW) is calculated again after the DATA transmission. Set to timer 16.

(A-2-5) DATA Reception Processing Next, reception processing of the nodes N11 to N32 that receive the transmitted DATA will be described with reference to FIG.

  When the transmitted transmission frame is given to the nodes N11 to N32, the transmission port address of the transmission frame is confirmed at the communication port 11, and if it is the address of the own node or the address for broadcast, the communication port 11 A transmission frame is received (S32).

  In the case of DATA, since each of the nodes N11 to N32 performs unicast transmission, the node that determines that the transmission destination address is not its own node address discards the DATA.

  The transmission frame received by the communication port 11 is given to the data storage unit 12 and temporarily stored (S33).

  When the transmission frame is stored in the data storage unit 12, the command analysis unit 14 checks the packet type of the packet header (S34). Thereby, it is determined that the received packet is a DATA packet.

  If it is determined that the received packet is a DATA packet, the comparison / search unit 15 compares whether or not the transmission destination name in the packet header matches the sync name in the routing table 13a (S35).

  If the transmission destination name in the packet header does not match the sync name in the routing table 13a, the received packet is discarded (S36).

  On the other hand, if the transmission destination name in the packet header matches the sync name in the routing table 13a, the sync name and request identification number of the data command of the received packet and the data created in the past stored in the data storage unit 12 A data command whose command sync name and request identification number match is searched by the comparison search unit 15 (S37).

  When the data command is searched by the comparison search unit 15, the command analysis unit 14 performs data integration processing between the received data command and the data command created in the past (S38).

  At this time, the larger hop number of the hop counts between the received data command and the data command created in the past is written in the network scale of the data command. The number of times added is written, and the result obtained by integrating or statistically processing both data values is written in the data value.

  In the data integration or statistical processing, the result of integration or statistical calculation by the calculation unit 17 is written in the data value of the data command. In this embodiment, the result of the calculation unit 17 calculating the maximum value and the average value of the temperature calculated by the calculation unit 17 is written in the data value.

  When the data command is updated / integrated in this way, the data command that has been integrated is stored in the data storage unit 12. And it transmits when transmission waiting time (TW) passes.

  When the network scale of the data command is updated, the network scale of the routing table 13a is also updated (S39). This network scale update is reflected when the next transmission waiting time (TW) is calculated.

  Further, the instruction analysis process 14 adds “1” to the RDN of the track record information of the node in the routing table 13a and updates it every time data is received and integrated (S40).

(A-2-6) Report Command Creation and Transmission Processing Next, creation of a report command in which each node notifies the adjacent upstream node of the DATA reception / transmission (relay) status will be described with reference to FIG.

  When data integration is performed for the received data command and DATA is transmitted (S41), a report command is generated by the instruction analysis unit 14.

  In the report command, the instruction analysis unit 14 writes the sync name and request identification number of the transmitted data command in the sync name and request identification number of the report command. In addition, the name of the own node is written in the node name of the report command.

  Further, the command analysis unit 14 reads the node performance information from the routing table 13a (S42), and the read node performance information (RDN and TDN) is written in the data transfer performance information of the report command. Then, a report command is created (S43).

When the report command is created, a report packet is formed in the report command by the instruction analysis unit 14 (S44).
At this time, in the Report packet, a report command is inserted into the packet payload, the name of the own node is inserted into the transmission source name of the packet header, and the node name with the maximum hop count is inserted into the transmission destination name of the packet header. Shown in the type as a report command.

  The Report packet formed by the instruction analysis unit 14 is given to the communication port 11, and in the communication port 11, a frame header in which the own node address is written in the transmission source address and the broadcast address is written in the transmission destination address. A transmission frame (hereinafter referred to as “Report”) that is attached to the Report packet and includes a report command is transmitted by broadcast (S45).

  Thereby, the performance information of the node which transmitted DATA can be provided to an adjacent node.

  Further, after the transmission of the report, the instruction analysis unit 14 resets the contents of the node record information in the routing table 13a (S46). However, the TDN of the track record information of the node is “0”.

(A-2-7) Report Reception Processing Next, report reception processing of the nodes N11 to N32 will be described with reference to FIG.

  When the transmission frame is given to the nodes N11 to N32, the transmission destination address of the transmission frame is confirmed at the communication port 11, and the communication port 11 receives the transmission frame when it is the address of the own node or the address for broadcast. (S47).

  In the case of Report, since it is transmitted by broadcast, all adjacent nodes receive it.

  The received transmission frame is given to the data storage unit 12 and temporarily stored (S48), and the packet type of the packet header is confirmed by the command analysis unit 14 (S49). As a result, it is determined that the received packet is a Report packet.

  If it is determined that the received packet is a report packet, the comparison / search unit 15 compares the sync name of the report command with the sync name of the routing table 13a (S50).

  If the sync name of the report command does not match the sync name of the routing table 13a, the received packet is discarded (S51).

  On the other hand, if the sync name of the report command matches the sync name of the routing table 13a, it is determined whether or not the transmission source address of the received report matches the downstream node address of the routing table 13a (S51).

  When the transmission source address of the report matches the downstream node address of the routing table 13a, the command analysis unit 14 extracts the data transfer record information from the report command, and the data transfer record corresponding to the downstream node of the routing table 13a. The information is updated to the retrieved data performance information (S52).

  In addition, the RDN and TDN of the routing table 13a can be updated based on the data record information of the report command, but the TTDN can be updated by adding the value of the TDN immediately before the update.

  On the other hand, if the transmission source address of the report does not match the downstream node address of the routing table 13a, the received packet is discarded (S53).

  Thereby, the upstream node can receive the data transfer record information from the downstream node, manage the record information of the downstream node, and can contribute to the calculation of the degree of integration of the downstream node in the subsequent route selection. .

(A-3) Effects of Embodiment As described above, according to the present embodiment, in the many-to-one communication in which data is collected in the sink 20, it is not necessary to have information on all routes, only information on adjacent downstream nodes. The table size can often be reduced.

  Further, according to the present embodiment, each node can easily construct a table of adjacent downstream nodes that are the shortest path to the sink by flooding the data request (Query) from the sink 20.

  Furthermore, according to this embodiment, data transfer status reports are sequentially received from adjacent downstream nodes, and feedback is applied to selection of adjacent downstream nodes, so that efficient data integration can be realized. It is also possible to avoid using too much power due to excessive load concentration on a specific node.

  Further, according to the present embodiment, each node is notified of an accurate network scale from the upstream node at the stage of relaying data to the sink 20. Since the data transfer waiting time is sequentially calculated according to the network size and the accurate distance from the sink, data transmission / relay can be delayed for an appropriate time, so that data integration can be performed with high probability.

(B) Other Embodiments (B-1) In the above-described embodiment, the content of the information type requested by the information request command is “temperature”, but the content of the information type is not limited to this, for example, humidity, It can be measured at each node such as pressure and concentration, and can be widely applied if the sink 20 requires it.

  Further, even in a network in which an audio signal and an image signal are transmitted to an external network through a certain sink, the present invention can be applied when transmitting an audio signal and an image signal as DATA.

(B-2) In the embodiment described above, the information fed back to the upstream node by the report command is the data transfer count (RDN, TDN). If the transfer control status of the node is concerned, for example, the battery of each node Information such as the remaining amount, failure information, and traffic volume calculated by other methods may be used.

(B-3) In the above-described embodiment, a calculation example in which one transmission destination (adjacent downstream node) is selected from a plurality of transmission destinations in the routing table when transmitting DATA has been described. It may be.

(B-4) In the above-described embodiment, the case where the present invention is applied to a wireless communication apparatus configuring a multi-hop wireless communication network has been described. However, the form of the wireless communication network is not limited to this and can be widely applied.

It is a block diagram for demonstrating the network structure of embodiment. It is a block diagram which shows the internal structure of a node. It is a management item example of a routing table. It is explanatory drawing which shows the structural example of a transmission frame and a packet. It is explanatory drawing explaining the structural example of an information request command. It is explanatory drawing explaining the structural example of a data command. It is explanatory drawing explaining the structural example of a report command. It is a block diagram which shows the internal structure of a sink. It is a communication sequence diagram of the network according to the embodiment. It is a flowchart explaining the transmission operation | movement of an information request command. It is a flowchart explaining the reception operation | movement of the transmission frame in a node. It is a flowchart explaining the creation process of a routing table. It is a flowchart which shows the relay process of REQ in a node. It is a flowchart explaining the transmission operation of a data command. It is explanatory drawing which shows the example of preparation of a data command. It is a flowchart explaining the transmission process of a data command. It is a flowchart explaining the selection method of a transmission destination node. It is a flowchart explaining the reception process of DATA. It is a flowchart explaining the transmission process of a report command. It is a flowchart explaining the reception process of Report.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wireless network, 20 ... Sink, N11-N32 ... Node,
11 (11-1 to 11-n), 21 (21-1 to 21-n) ... communication ports,
12, 22 ... data storage unit, 13, 23 ... cache,
13a, 23a ... routing table, 14 ... instruction analysis unit,
24 ... Command generation unit 15, 25 ... Comparison / search unit 16, 26 ... Timer,
17, 27: Calculation unit, 18: Sensor unit.

Claims (8)

In a route management device that manages route information to a specific wireless communication device that requests information,
Communication means for performing wireless communication with other peripheral wireless communication devices;
Path information management means for managing the shortest path of path information to the specific radio communication device that has requested the information request each time an information request for the specific radio communication device is received;
Data creation means for judging the content of the received information request and creating request data in response to the information request;
Communication control means for updating the number of hops included in the received information request and transmitting it to other peripheral wireless communication devices, and transmitting the request data created by the data creation means apparatus. The route information management means
A routing table for managing the information about the downstream wireless communication apparatus immediately before transferring the information request, and the number of hops included in the information request for each information request;
The shortest path detection unit that detects the shortest path by comparing the transfer source information and the hop count information of the received information request with the management information of the routing table;
The route management apparatus according to claim 1, further comprising: a routing table update unit that updates the shortest route detected by the shortest route detection unit so as to be stored at least in a routing table.   3. The route management apparatus according to claim 1, wherein the data creation unit integrates the request data given from the immediately preceding upstream wireless communication device and the request data created by the data creation unit. A transmission destination in which the communication control means selects, as a transmission destination, a downstream wireless communication device that forms the shortest route to a specific wireless communication device based on the routing table of the route information management means when transmitting the request data Having a selection part,
The path management apparatus according to claim 2 or 3, wherein the communication control unit causes the request data to be transmitted to a transmission destination selected by the transmission destination selection unit.   The transmission destination selection unit, when there are a plurality of downstream wireless communication devices constituting the shortest path, selects a downstream wireless communication device having a relatively high data integration degree as a transmission destination among the downstream wireless communication devices. The route management device according to claim 4.   The communication control unit obtains a transmission standby time of the request data based on the number of hops to a specific wireless communication device and a network scale, and transmits the request data after the transmission standby time elapses. Item 6. The route management device according to any one of Items 1 to 5. A communication control status monitoring means for monitoring the communication control status of the communication control means and managing the monitoring result in the routing table;
The communication control means feeds back the monitoring result of the communication control status managed in the routing table to the upstream wireless communication apparatus after the transmission of the request data. The route management device described in 1. When the monitoring result of the communication control status is received from the immediately preceding downstream wireless communication device,
8. The route management device according to claim 7, wherein the routing table update unit updates information related to the downstream wireless communication device based on the received monitoring result of the communication control information.

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