JP2014192661A - Repeating device, repeating system, and repeating method - Google Patents

Abstract

An object of the present invention is to reduce a load generated during data transmission in a sensor network.
A database that accumulates and stores, for each transmission destination, packets to which accumulated information transmitted from a node is added, and timer management that manages an interval at which the accumulated packets stored in the database are transmitted to a server. And a communication unit that transmits packets accumulated at intervals to the server.
[Selection] Figure 2

Description

  The present invention relates to a technique of a data transmission method in a network.

Conventionally, sensor data collected by a plurality of sensor devices (hereinafter referred to as “nodes”) installed in a sensor network is transmitted to a server on the cloud via the network, so that various locations can be stored on the server. The sensor data in is integrated. By using the collected sensor data of various locations, it is possible to provide new services and improve the efficiency of operations. However, when a plurality of nodes transmit sensor data to the server via the network, packets having a small data size are periodically transmitted to the server. This increases the processing load on the server that receives the sensor data and the packet processing load on the network.
In response to such a problem, a plurality of techniques for reducing the load on the server and the network have been proposed. For example, a technique for reducing the processing load on the server side by controlling the transmission interval from the node to the server has been proposed (see, for example, Patent Document 1). In addition, a technique for reducing the load on the network by aggregating data of child nodes at the parent node and transmitting the data to the server has been proposed (see, for example, Patent Document 2).

JP 2011-142439 A JP 2006-287565 A

  However, with the technique of Patent Document 1, it is possible to reduce the processing load on the server side by changing the packet transmission interval, but it is not possible to reduce the load on the network. Further, with the technique of Patent Document 2, it is possible to reduce the processing load on the server side and the load on the network, but the node processing needs to be aggregated, and the processing of the node becomes complicated. Therefore, there arises a problem that the processing load of the node becomes large. As described above, the conventional technique has a problem that the load on the network or the node cannot be reduced when the sensor data is transmitted from the node to the server.

  In view of the above circumstances, an object of the present invention is to provide a technique for reducing a load generated during data transmission in a sensor network.

  One embodiment of the present invention is a database that accumulates and stores, for each transmission destination, packets to which accumulated information transmitted from a node is added, and an interval at which the accumulated packets stored in the database are transmitted to a server. A relay device comprising a timer management unit that manages the communication and a communication unit that transmits the packets accumulated at the intervals to a server.

  One aspect of the present invention is the relay device described above, an acquisition unit that acquires the size information of the packet, and maximum size information that can transmit the packet acquired when the device is connected to the server; And an aggregation number calculating unit that calculates the aggregable number of packets accumulated in the database based on the packet size information, and the communication unit accumulates based on the aggregable number The transmitted packet is transmitted to the server.

  One aspect of the present invention is a system including a plurality of nodes and a relay device that relays packets transmitted from the nodes to a server, wherein the nodes collect data representing surrounding spatial information And a communication unit that transmits the packet including the data collected by the sensor to the relay device, and the relay device stores, for each transmission destination, a packet to which storage information transmitted from a node is added. A database to be stored, a timer management unit for managing an interval for transmitting the accumulated packets stored in the database to the server, a communication unit for transmitting the packets accumulated at the interval to the server, Is a relay system.

  One aspect of the present invention is a storage step of storing, for each transmission destination, a packet to which accumulated information transmitted from a node is added and storing it in a database; and storing the accumulated packet stored in the database in a server It is a relay method comprising a timer management step for managing an interval for transmission and a communication step for transmitting the packets accumulated at the interval to a server.

  According to the present invention, it is possible to reduce a load generated when data is transmitted in a sensor network.

It is a figure which shows the system configuration | structure of the relay system in this embodiment. 2 is a schematic block diagram illustrating a functional configuration of a GW device 20. FIG. It is a figure showing the specific example of the method of accumulate | storing a request message. It is a figure which shows the specific example of the request message in which the buffering option is not described. It is a flowchart which shows the specific example of the flow of the transmission interval calculation process in this embodiment. It is a flowchart which shows the specific example of the flow of the sensor data transmission process in this embodiment. It is a sequence diagram which shows the specific example of operation | movement of the sensor data transmission process in this embodiment.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram illustrating a system configuration of a relay system according to the present embodiment. The relay system of this embodiment includes a plurality of nodes 10-1 to 10-3, a GW (Gate Way) device 20, a server 30, and a network 50. In the following description, the nodes 10-1 to 10-3 are referred to as nodes 10 unless otherwise distinguished.

The node 10 is a wireless terminal with a sensor, and collects spatial information around its own device. Spatial information is information detected by a sensor attached to the node 10, for example, information such as temperature and humidity around the device itself. Further, the node 10 periodically transmits the collected spatial information (sensor data) to the GW device 20. The node 10 forms a sensor network 40 by being arranged at various locations.
The GW device 20 is a relay device that relays communication between the node 10 and the network 50. The GW device 20 transmits the sensor data transmitted from the node 10 to the server 30 via the network 50.

The server 30 is configured using an information processing apparatus and collects sensor data transmitted from the GW device 20.
The sensor network 40 is formed by a plurality of nodes 10.
The network 50 may be a network configured in any way. For example, the network 50 may be configured using the Internet.

  FIG. 2 is a schematic block diagram illustrating a functional configuration of the GW device 20. The GW device 20 includes a CPU (Central Processing Unit), a memory, an auxiliary storage device, and the like connected by a bus, and executes a relay program. By executing the relay program, the GW device 20 includes a communication unit 201, a control unit 202, an acquisition unit 203, an aggregation number calculation unit 204, a reception interval calculation unit 205, a transmission interval calculation unit 206, an analysis unit 207, a timer management unit 208, It functions as an apparatus including the database 209 and the generation unit 210. Note that all or part of the functions of the GW device 20 may be realized using hardware such as an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA). The relay program may be recorded on a computer-readable recording medium. The computer-readable recording medium is, for example, a portable medium such as a flexible disk, a magneto-optical disk, a ROM, a CD-ROM, or a storage device such as a hard disk built in the computer system. Further, the relay program may be transmitted / received via a telecommunication line.

The communication unit 201 performs wireless communication with the node 10. In addition, the communication unit 201 communicates with the server 30. For example, the communication unit 201 receives a request message storing sensor data from the node 10 and transmits the request message to the server 30. In addition, the communication unit 201 receives the response message transmitted from the server 30 and transmits it to the node 10. Further, the communication unit 201 acquires a value of MSS (Maximum Segment Size) when establishing a connection with the server 30. The MSS represents the maximum size that can transmit a packet in one communication.
The control unit 202 controls each functional unit of the GW device 20.

The acquisition unit 203 collects packets of sensor data periodically transmitted from the node 10 to the server 30 for a certain period (for example, 30 minutes, 1 hour, etc.). For example, the acquisition unit 203 collects packets of sensor data that are transmitted from the node 10 to the server 30 by WireShar (registered trademark). Thereafter, the acquisition unit 203 acquires each value of the header size and the body size from the collected packets. The body size (size information) represents the size of sensor data stored in the payload of the packet.
The aggregation number calculation unit 204 calculates the aggregation possible number using the MSS value and the acquired header size and body size values. The aggregable number represents the number of sensor data that can be aggregated into one packet transmitted from the own device (GW device 20) to the server 30.

The reception interval calculation unit 205 calculates the sensor data reception interval based on the sensor data packets periodically collected by the acquisition unit 203. For example, the reception interval calculation unit 205 calculates the reception interval of sensor data based on the difference between the reception time of the collected packet of sensor data and the reception time of the packet of sensor data collected after collecting the packet. To do.
The transmission interval calculation unit 206 transmits the number of aggregations calculated by the aggregation number calculation unit 204 and the reception interval calculated by the reception interval calculation unit 205 from the own device (GW device 20) to the server 30. A transmission interval for transmitting sensor data is calculated. For example, the transmission interval calculation unit 206 calculates, as the transmission interval, a value obtained by multiplying the value of the aggregateable number and the value of the reception interval. The transmission interval calculation unit 206 notifies the timer transmission unit 208 of the calculated transmission interval.

  The analysis unit 207 analyzes the request message transmitted from the node 10. Specifically, first, the analysis unit 207 acquires values of a request method, a request URL (Uniform Resource Locator), a request URI (Uniform Resource Identifier), and a request body from the request message received by the communication unit 201. A request method represents a process for requesting a resource that has received a request message. The request URL represents an identifier for identifying a destination to which the request message is transmitted. The request URI represents an identifier that specifies a resource to which the request is applied. The request body represents data (sensor data) transmitted to the server 30.

Next, the analysis unit 207 determines whether or not buffering option information (hereinafter simply referred to as a buffering option) is described in the header portion of the request message. The buffering option (accumulated information) is information indicating whether to transmit the sensor data stored in the request message collectively.
When the buffering option is described, the analysis unit 207 accumulates the acquired sensor data in the database 209. At this time, the analysis unit 207 stores the sensor data in the database 209 using the request URL corresponding to the acquired sensor data as an index.
On the other hand, when the buffering option is not described, the analysis unit 207 instructs the generation unit 210 to generate a request message for transmitting the acquired sensor data to the server 30.

  The analysis unit 207 analyzes the response message transmitted from the server 30. The analysis unit 207 acquires each value of the status code and the response body from the transmitted response message. The response body represents response data transmitted from the server 30. Thereafter, the analysis unit 207 instructs the generation unit 210 to generate a response message.

  The timer management unit 208 manages the timer based on the result analyzed by the analysis unit 207. For example, the timer management unit 208 counts down the transmission interval notified from the transmission interval calculation unit 206 for each request URL of the request message when the analysis unit 207 determines that the buffering option is described in the request message. To start.

The database 209 is configured using a storage device such as a magnetic hard disk device or a semiconductor storage device. The database 209 stores sensor data for each request URL.
The generation unit 210 generates a first request message using the acquired request method, request URI, and request body. Specifically, the generation unit 210 generates a first request message by storing a request method and a request URI in a header and storing a request body in a body part. The first request message is a request message in which one sensor data transmitted from the node 10 is stored.

In addition, the generation unit 210 generates a response message using the acquired status code and response body. Specifically, the generation unit 210 generates a response message by storing a status code in the header and storing a response body in the body part.
Further, when the expiration of the timer is notified from the timer management unit 208, the generation unit 210 generates a second request message using the sensor data recorded in the database 209. The second request message is a request message in which a plurality of sensor data is stored. Specifically, first, the generation unit 210 acquires sensor data corresponding to the request URL notified of expiration of the timer from the database 209. Next, the generation unit 210 generates a request body using the acquired sensor data. Thereafter, the generation unit 210 generates a second request message using the request method, the request URI, and the generated request body.

  FIG. 3 is a diagram illustrating a specific example of a method for accumulating request messages. FIG. 3A is a diagram illustrating a request message transmitted from the node 10. “A” in FIG. 3A represents a header portion composed of a request line and a message header, and “b” in FIG. 3A represents a body portion of the request message. The header portion “a” in FIG. 3A includes a request method, a request URL, a request URI, an HTTP (Hypertext Transfer Protocol) version, a source address, a body portion size, a buffering option, a connection state, and the like. Each information is described. In the example shown in FIG. 3A, the buffering option “Buffering: on” is described in the header portion “a”. The buffering option is given when the node 10 determines that sensor data needs to be accumulated. The node 10 stores a table for determining whether or not accumulation is necessary in advance, and it is necessary to describe the buffering option in the request message by checking the table every time sensor data is acquired. Judge whether there is. For example, the table stores destinations and user IDs for which sensor data needs to be accumulated. If the acquired sensor data is data that only transmits a PIN (Personal identification number) such as a management protocol, the node 10 determines that there is no need to store the data and does not describe a buffering option. When the buffering option is described in the received request message, the analysis unit 207 stores the sensor data in the database 209 using the request URL described in the header portion “a” as an index. In addition, sensor data collected by the node 10 is described in the body part “b” in FIG.

  FIG. 3B is a diagram illustrating a request message transmitted from the node 10 after a predetermined time (for example, 10 minutes, 1 hour, etc.) has elapsed from the request message in FIG. The buffering option “Buffering: on” is also described in the header portion of the request message shown in FIG. That is, the request message shown in FIG. 3B also stores sensor data in the database 209 with the request URL as an index. FIG. 3C illustrates a second request message in which the sensor data of the request message of FIG. 3A and the sensor data of the request message of FIG. 3B are accumulated.

Next, a method for adding request message sensor data will be described with reference to FIG. When the request message of FIG. 3B is received after the sensor data of the request message of FIG. 3A is accumulated in the database 209, the analysis unit 207 acquires the request URL described in the header portion. . Next, the analysis unit 207 searches the database 209 using the acquired request URL as an index. The analysis unit 207 adds the sensor data of the request message acquired after the sensor data of the searched request URL.
This is the end of the description of the method for adding the request message sensor data.

FIG. 4 is a diagram illustrating a specific example of a request message in which a buffering option is not described.
In the request message shown in FIG. 4, the buffering option “Buffering: on” is not described in the header part “c” of the request message. Therefore, the sensor data of the request message shown in FIG. 4 is not accumulated in the database 209. In this case, the quest message illustrated in FIG. 4 is transmitted to the server 30.

FIG. 5 is a flowchart showing a specific example of the flow of transmission interval calculation processing in the present embodiment.
First, the communication unit 201 of the GW device 20 transmits a Syn packet to the server 30 (step S101). At this time, the communication unit 201 stores the MSS value used for communication between the own device (GW device 20) and the server 30 in the Syn packet. Next, the communication unit 201 receives a Syn / Ack packet from the server 30 (step S102). At this time, the communication unit 201 acquires the MSS value stored in the received Syn / Ack packet. Then, the communication unit 201 transmits an Ack packet to the server 30 (step S103). The connection between the GW device 20 and the server 30 is established by performing the processes of steps S101 to S103.

Thereafter, the communication unit 201 acquires the MSS value used for communication with the server 30 (step S104). Specifically, the communication unit 201 compares the MSS value transmitted to the server 30 with the received MSS value, and acquires the smaller MSS as the MSS value used for communication with the server 30.
Next, the acquisition unit 203 collects packets of sensor data transmitted from the node 10 to the server 30 for a certain period (step S105). The acquisition unit 203 acquires each value of the header size and the body size from the collected packet (step S106). Specifically, the acquisition unit 203 acquires the size of the HTTP header of the acquired packet and the size of the sensor data stored in the payload.

  The aggregation number calculation unit 204 calculates the number of sensor data that can be aggregated using the MSS value and the header size and body size values (step S107). The reception interval calculation unit 205 calculates the reception interval of the sensor data packets based on the difference in the reception times of the packets collected for a certain period by the acquisition unit 203 (step S108). Thereafter, the transmission interval calculation unit 206 calculates the transmission interval using the calculated reception interval value and the value of the number that can be aggregated (step S109). For example, the transmission interval calculation unit 206 calculates the transmission interval by multiplying the value of the reception interval by the value of the number that can be aggregated. Then, the transmission interval calculation unit 206 notifies the timer management unit 208 of the calculated transmission interval value. Thereafter, the transmission interval calculation process ends.

FIG. 6 is a flowchart showing a specific example of the flow of sensor data transmission processing in the present embodiment.
The communication unit 201 of the GW device 20 receives a request message periodically transmitted from the node 10 (step S201). The analysis unit 207 analyzes the received request message (step S202). Specifically, the analysis unit 207 acquires each value of the request method, the request URL, the request URI, and the sensor data stored in the received request message. Thereafter, the analysis unit 207 determines whether or not a buffering option is described in the header portion (step S203). When the buffering option is described (step S203—YES), the analysis unit 207 searches the database 209 using the acquired request URL as an index. Then, the analysis unit 207 accumulates the sensor data acquired in the process of step S203 in the database 209 after the sensor data of the searched request URL (step S204).

On the other hand, when the buffering option is not described (step S203—NO), the generation unit 210 generates a first request message to be transmitted to the server 30 based on the received request message (step S205). Specifically, the generation unit 210 generates a first request message by storing a request method and a request method URI in the header part of the request message and storing a request body in the body part. Then, the communication unit 201 transmits the generated first request message to the server 30 (step S214).
Moreover, after the process of step S204, the production | generation part 210 produces | generates the response message containing the information which shows having accumulate | stored sensor data (step S206). The communication unit 201 transmits the generated response message to the node 10 (step S207).

  Next, the timer management unit 208 determines whether or not the timer corresponding to the request URL of the request message received in step S201 is activated (step S208). When the timer is activated (YES in step S208), the timer management unit 208 determines whether or not the timer corresponding to the request URL of the request message received in step S201 has expired (step S209). On the other hand, if the timer is not activated in the processing of step S208 (step S208-NO), the timer management unit 208 sets the value calculated by the transmission interval calculation unit 206 in the own device and starts the timer (step S208). S210). And the process after step S201 is repeatedly performed.

When the timer has expired (step S209—YES), the timer management unit 208 notifies the generation unit 210 of the expiration of the timer (step S211). On the other hand, in the process of step S209, when the timer is not expired (step S209—NO), the processes after step S201 are repeatedly executed.
Next, when the expiration of the timer is notified, the generation unit 210 refers to the database 209 and generates a request body using the request method of the request message received in the process of step S201 and the sensor data corresponding to the request URI. . (Step S212). The generation unit 210 generates a second request message using the request method, the request URI, and the generated request body (step S213). Specifically, the second request message is generated by storing the request method and request URI in the header portion and storing the request body in the body portion. Thereafter, the communication unit 201 transmits the generated second request message to the server 30 (step S214).

FIG. 7 is a sequence diagram showing a specific example of the operation of the sensor data transmission process in the present embodiment.
The node 10 transmits a request message including the sensor data to the GW device 20 (step S301). The communication unit 201 of the GW device 20 receives the request message transmitted from the node 10. Thereafter, the analysis unit 207 analyzes the received request message (step S302). When the buffering option is described in the request message, the analysis unit 207 accumulates the sensor data stored in the request message in the database 209 (step S303). On the other hand, when the buffering option is not described in the request message, the generation unit 210 generates a first request message based on the received request message. Thereafter, the communication unit 201 transmits the generated first request message to the server 30.

Further, the generation unit 210 generates a response message using a status code representing a result for the request and a response body (step S304). The communication unit 201 transmits the generated response message to the node 10 (step S305). After that, the timer management unit 208 sets the transmission interval calculated by the transmission interval calculation unit 206 in the timer, and starts timer countdown (step S306).
The node 10 transmits a request message including the sensor data to the GW device 20 (step S307). The communication unit 201 of the GW device 20 receives the request message transmitted from the node 10. Thereafter, the analysis unit 207 analyzes the received request message (step S308).

  When the buffering option is described in the request message, the analysis unit 207 accumulates the sensor data stored in the request message transmitted in step S307 in the database 209 (step S309). Further, the generation unit 210 generates a response message using a status code representing a result for the request and a response body (step S310). The communication unit 201 transmits the generated response message to the node 10 (step S311).

  When the timer corresponding to the request URL of the request message transmitted in the process of step S307 expires, the timer management unit 208 notifies the generation unit 210 that the timer has expired. When the expiration of the timer is notified from the timer management unit 208, the generation unit 210 refers to the database 209 and generates a request body using the sensor data corresponding to the request URL of the request message transmitted in step S307. (Step S312). Thereafter, the generation unit 210 generates a second request message using the request method, the request URI, and the request body (step S313). Specifically, the generation unit 210 generates a second request message by storing the request method and the request URI in the header part and storing the request body in the body part. The communication unit 201 transmits the generated second request message to the server 30 (step S314).

The server 30 receives the second request message transmitted from the GW device 20. Next, the server 30 records the sensor data stored in the received second request message in the database. Then, the server 30 generates a response message. Thereafter, the server 30 transmits the generated response message to the GW device 20 (step S315).
The communication unit 201 of the GW device 20 receives the response message transmitted from the server 30. The analysis unit 207 analyzes the transmitted response message (step S316). The generation unit 210 generates a response message (step S317). The communication unit 201 transmits the generated response message to the node 10 (step S318).

  According to the GW device 20 configured as described above, a plurality of sensor data is accumulated based on the request URL given to the request message. Therefore, every time sensor data is transmitted from the node 10, sensor data is not transmitted, and the number of accesses to the server 30 decreases. In addition, since a plurality of sensor data is transmitted as one data, the amount of communication can be reduced, and the processing load on the server 30 can also be reduced. Further, the GW device 20 transmits the sensor data accumulated in the maximum size that does not cause fragmentation to the server 30. For this reason, it is possible to reduce a load generated when data is transmitted in the sensor network.

<Modification>
In this embodiment, the number of nodes 10 existing in the relay system is three, but the number of nodes 10 may be four or more, or the number of nodes 10 may be two or less. .
In the present embodiment, the number of GW devices 20 existing in the relay system is one, but the number of GW devices 20 may be configured by a plurality.
Further, the timing at which the GW device 20 transmits the sensor data stored in the server 30 need not be limited to the above-described timing. For example, the GW device 20 may transmit the sensor data to the server 30 when the number of sensor data stored in the database 209 exceeds the number that can be aggregated. Further, the transmission interval may be set by the user.
In the present embodiment, the GW device 20 is used as a relay device that transmits sensor data to the server 30. However, the present invention is not limited to this, and any relay device having a proxy function may be used. It may be a device.
The buffering option may be described in the body part of the request message.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and includes designs and the like that do not depart from the gist of the present invention.

10 (10-1 to 10-3) ... node, 20 ... GW device, 30 ... server, 40 ... sensor network, 50 ... network, 201 ... communication unit, 202 ... control unit, 203 ... acquisition unit, 204 ... number of aggregation Calculation unit, 205 ... Reception interval calculation unit, 206 ... Transmission interval calculation unit, 207 ... Analysis unit, 208 ... Timer management unit, 209 ... Database, 210 ... Generation unit

Claims (4)

A database for storing and storing packets with accumulated information transmitted from nodes for each destination;
A timer management unit for managing an interval for transmitting the accumulated packets stored in the database to a server;
A communication unit that transmits the packet accumulated at the interval to a server;
A relay device comprising: An acquisition unit for acquiring size information of the packet;
Aggregation for calculating the number of packets that can be accumulated in the database based on the maximum size information that can be transmitted when the packet is connected to the server and the size information of the packets. A number calculator,
Further comprising
The relay device according to claim 1, wherein the communication unit transmits the accumulated packets to a server based on the aggregation possible number. A system comprising a plurality of nodes and a relay device that relays packets transmitted from the nodes to a server,
The node is
A sensor that collects data representing the surrounding spatial information;
A communication unit for transmitting a packet including the data collected by the sensor to the relay device;
With
The relay device is
A database for storing and storing packets with accumulated information transmitted from nodes for each destination;
A timer management unit for managing an interval for transmitting the accumulated packets stored in the database to a server;
A communication unit that transmits the packet accumulated at the interval to a server;
A relay system comprising: A storage step of storing, for each transmission destination, a packet to which accumulated information transmitted from a node is added and storing it in a database;
A timer management step for managing an interval for transmitting the accumulated packets stored in the database to a server;
A communication step of transmitting the packets accumulated at the intervals to a server;
A relay method.

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