JP2007193748A - Communication node, sensor network system, and task processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication node, a sensor network system, and a task processing method for allowing reduction in a task processing cost and execution of more tasks. <P>SOLUTION: This communication node constituting the sensor network system is provided with a task determination means for determining resources necessary for task processing based on a task processing request, a processing method determination means for determining a task processing method based on the necessary resources, and a task processing means for performing task processing according to the processing method. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a communication node and a sensor network system for performing control for processing more tasks in a sensor network configured based on a connection established by a plurality of general-purpose sensor nodes with adjacent nodes. It relates to a task processing method.

  In a general sensor network system, a sensor node is often a device having a relatively small processing capability. Therefore, task processing cost reduction and decentralization are major issues.

  For example, in a certain sensing system, the required accuracy is transmitted from the server to the sensor node. The sensor node transmits a threshold value corresponding to the required accuracy to the sensor. The sensor compares the threshold variable means that changes the threshold according to the threshold received from the sensor node, the predetermined sensor, the analog value output by the sensor, and the changed threshold, and transmits the comparison result to the sensor node. The sensor node extracts the digital information according to the results output from the plurality of sensors, and transmits the extracted digital information to the server.

  As a result, the sensor node with low processing capability normally operates only the analog data comparator, and performs a relatively heavy process of digitizing the sensing data only when the threshold value is exceeded. By doing so, it is possible to reduce the processing cost in the sensor node (see, for example, Patent Document 1).

Further, for example, in a certain multi-sensor processing device, data obtained from sensor nodes is distributedly processed by a plurality of processing devices. By doing in this way, it becomes possible to determine the processing content of the sensor according to the number of processing devices allocated to the sensor determined to be used. In addition, a single processing device is not stopped due to overload (see, for example, Patent Document 2).
JP 2005-122655 A JP 2002-157233 A

  However, the background art described above has the following problems.

  In the sensing system disclosed in Patent Document 1, in order to determine the necessity of digital processing of each sensor node based on the threshold value of the signal magnitude of the detected event, conditions other than the signal magnitude may be set. Can not. Therefore, it is impossible to reduce the signal processing cost.

  In the multi-sensor processing device disclosed in Patent Document 2, data processing obtained as a result of sensing is distributed, and the sensing processing cost of the sensor node itself is not reduced.

  Therefore, an object of the present invention is to provide a communication node, a sensor network system, and a task processing method that can reduce task processing costs and execute more tasks.

  In order to solve the above-described problem, a communication node according to the present invention is a communication node constituting a sensor network system, and a task determination unit that determines a resource required for task processing based on a task processing request, and the necessary node One of the features is a processing method determination unit that determines a task processing method based on a resource, and a task processing unit that performs task processing according to the processing method.

  With this configuration, each communication node can determine a resource necessary for the requested task and determine a necessary processing method. As a result, the corresponding task can be processed in cooperation by a plurality of sensor nodes.

  The sensor network system of the present invention is a sensor network system including a plurality of communication nodes, and the communication node includes task determination means for determining resources necessary for task processing based on a task processing request. One of the characteristics is that it includes a processing method determination unit that determines a processing method of a task based on the necessary resource, and a task processing unit that performs task processing according to the processing method.

  By configuring in this way, each communication node constituting the sensor network system can determine the necessary resource for the requested task and determine the necessary processing method. As a result, the corresponding task can be processed in cooperation by a plurality of sensor nodes.

  The task processing method of the present invention is a task processing method in a communication node constituting a sensor network system, based on a connection establishment step for establishing a connection with another communication node, and a task processing request, A task determination step for determining a resource required for task processing; a processing method determination step for determining a task processing method based on the required resource; and a task processing step for performing task processing according to the processing method. It has one of the characteristics.

  In this way, a given task can be executed cooperatively by a plurality of sensor nodes.

  According to the embodiments of the present invention, it is possible to realize a communication node, a sensor network system, and a task processing method that can reduce task processing costs and execute more tasks.

Next, the best mode for carrying out the present invention will be described based on the following embodiments with reference to the drawings.
In all the drawings for explaining the embodiments, the same reference numerals are used for those having the same function, and repeated explanation is omitted.

  A sensor network system according to an embodiment of the present invention will be described with reference to FIG.

The sensor network system 10 according to the present embodiment includes a client node 100 and sensor nodes 200 (200 ₁ , 200 ₂ , 200 ₃ ,... As one or a plurality of communication nodes that can be connected to the client node 100 by wire or wirelessly. , 200 _n ) (where n is an integer of 1 <n). The sensor nodes 200 can be connected to each other by wire or wireless.

The client node 100 transmits a task request 103 to the sensor network system. For example, client node 100 transmits a task request to the sensor node 200 _1.

The sensor node 200 establishes a connection with adjacent sensor nodes to form a sensor network. The sensor node 200 ₁ receives the task request from the client node 100 performs predetermined processing to be described later, the task processing request (task request process message) 104 sensor nodes with another same function, for example, the sensor node 200 ₂ Send. By doing in this way, each sensor node 200 can process a task in cooperation. One of the sensor node that has received the task request from the client node 100 or another sensor node that has received the task processing request from the sensor node returns a response 105 to the client node 100 as necessary.

  Next, the sensor node 200 in the sensor network system 10 according to the present embodiment will be described with reference to FIG.

  The sensor node 200 according to the present embodiment includes a communication unit 202, a task determination unit 203 connected to the communication unit 202, a processing method determination unit 204, a task processing unit 205, and a sensing unit 206 connected to the task processing unit 205. With.

  The communication unit 202 establishes connection with other communication nodes, for example, the client node 100 and the sensor node 200, and performs communication.

  Based on at least one of the task request from the client node 100 and the task processing request from the other sensor node 200, the task determination unit 203 determines necessary resource information, for example, the sensor type, from the requested task content. And grasping at least one of processing conditions and events to be observed.

  The processing method determination unit 204 determines a task processing method, for example, a sensor node required for task processing, according to information on necessary resources grasped by the task determination unit 203 and the status of other tasks being executed. Number, execution schedule in each sensor node, and the like.

  The task processing unit 205 executes task processing in accordance with the task processing method determined by the processing method determination unit 204.

  The sensing unit 206 observes a predetermined event by performing sensing as necessary according to a command from the task processing unit 205. The sensing unit 206 notifies an observation result, for example, an environmental sensing result.

  Next, the operation of each part of the sensor node 200 will be described.

  The operation of the task determination unit 203 will be described with reference to FIG. The task determination unit 203 determines a necessary resource for the requested task.

  The communication unit 202 receives a task request or task processing request (task request processing message) from another node, for example, the client node 100 or the sensor node 200, and notifies the task determination unit 203 of it (step S302).

  Next, the task determination unit 203 determines a task from the content of the notified task request or task processing request. Also, the task determination unit 203 extracts resource information indicating at least one of the resources required for task processing, for example, the sensor type, the processing condition, and the observed event based on the task (step S304).

  Next, the task determination unit 203 notifies the processing method determination unit 204 of the extracted resource information (step S306). The task determination unit 203 inputs task information to the task processing unit 205. In this way, the sensor node can grasp the conditions necessary for processing the task.

  Here, a method in which the task determination unit 203 extracts requested resource information from the task content in step S304 will be described with reference to FIG.

  For example, the task determination unit 203 extracts requested resource information from the requested task (requested task) information (step S402). For example, the task determination unit 203 extracts necessary information from the contents of the requested task (step S404).

  For example, in the request task, there is information (notifying accuracy within 10 seconds) indicating notification when the temperature becomes 40 ° C. or more, and information (response time within 1 second) indicating response of the current temperature in response to the request. included.

  The task determination unit 203 describes the extracted necessary information in a format such as metadata (step S406).

  For example, the task determination unit 203 describes a sensor type, detection accuracy, response time, and the like as task category metadata. The task determination unit 203 describes a temperature sensor as the sensor type, 10 s as the detection accuracy, and 1 s as the response time.

  In response to the task request, the requested resource information may be stored in advance as metadata. In this case, the task determination unit 203 extracts only relevant metadata from the task request.

  The requested resource information items include the sensor type used, sensor detection accuracy, response time, etc. as described above, but other items may be used as the requested resource information items. . Further, the requested resource information may be described by a method other than metadata.

  Next, a procedure for determining an appropriate task processing method for processing a requested task in the processing method determination unit 204 will be described with reference to FIG.

  The processing method determination unit 204 receives resource information required for task processing from the task determination unit 203 (step S502).

  Next, the processing method determination unit 204 generates a message for searching for a sensor node that meets the resource condition based on the requested resource information. For example, the processing method determination unit 204 generates a message for searching for a sensor node suitable for appropriate conditions, for example, a sensor type, an installation location, and the like based on requested resource information. The processing method determination unit 204 inputs the generated message to the communication unit 202. The communication unit 202 broadcasts the input message. The processing method determination unit 204 waits for a response from the corresponding sensor node (step S504).

  The processing method determination unit 204 determines whether or not the communication unit 202 has received a response from one or more sensor nodes that meet the resource condition (step S506).

  When a response from at least one sensor node that matches the resource condition is not received (step S506: NO), the processing method determination unit 204 transmits the task request source, that is, the client node 100 that transmitted the task request or the task processing request. A non-executable notification indicating that the sensor node is not executable is transmitted to the sensor node (step S508).

  On the other hand, when a response from at least one sensor node that matches the resource condition is received (step S506: YES), the processing method determination unit 204 determines the task processing execution status of the sensor node and the number of surrounding sensor nodes. That is, based on the number of responding sensor nodes, the task processing schedule and the sensor node processing order to be executed are determined (step S510).

  Next, the processing method determination unit 204 inputs information indicating the task processing schedule and the sensor node processing order to be executed to the task processing unit 205 (step S512).

  By doing so, it is possible to obtain an appropriate method for executing a given task in cooperation with a plurality of sensor nodes.

  Here, the execution status of the task processing of the own sensor node and the method of detecting the number of surrounding sensor nodes when determining the task processing schedule in step S510 will be described with reference to FIGS. 6A to 6D.

  The processing method determination unit 204 confirms the task execution schedule of the own sensor node. For example, the processing method determination unit 204 confirms a task execution schedule as shown in FIG. 6A. In FIG. 6A, the horizontal axis indicates time, and the sensor node executes one or more tasks on a predetermined schedule. For example, the sensor node executes tasks A and B at a certain timing, tasks A, B and C at the next timing, and tasks A, B and D at the next timing.

  The processing method determination unit 204 confirms the processing conditions in the resource information extracted by the requested task. For example, the processing method determination unit 204 confirms a processing condition of “measurement temperature once every minute and issue a notification if the temperature is 40 degrees or more”.

  When a new task is processed only by its own sensor node, in the execution situation as shown in FIG. 6A, another task is included, that is, the task is executed at all timings. Execution becomes impossible.

  However, if tasks are distributed and executed by two or three nodes as shown in FIGS. 6C and 6D, new tasks can be processed. In this way, the number of other sensor nodes around which the task can be distributed and executed is determined so that it can be processed by the own sensor node.

  Next, the processing of the task processing unit 205 will be described with reference to FIG. The task processing unit 205 processes the requested task.

  The task processing unit 205 receives information indicating the task processing schedule for task processing and the sensor node processing order from the processing method determination unit 204, and receives information indicating the content of the task from the task determination unit 203 (step S702).

  Next, the task processing unit 205 assigns a unique ID for each task based on information indicating the content of the task. Further, the task processing unit 205 sends a task processing request message including a task ID, a task processing schedule, a sensor node processing order, and task contents as shown in FIG. Is transmitted to the adjacent sensor node that has been established (step S704).

  As an example, a task processing request message in the case where three sensor nodes sequentially process a task every minute will be described with reference to FIG. 8B.

  In this case, the task processing request message includes a task processing schedule as follows: 1. Task reception Task execution, 3.1 minute stop, 4. Information indicating task transmission is stored, information indicating that processing is performed in the order of A, B, C, A,... Is stored as the sensor node processing order, and the temperature of the task content is 40 degrees or higher. Information indicating notification to the client node is stored.

  Next, the task processing unit 205 processes the task according to the task processing schedule (step S706).

  Next, the task processing unit 205 determines whether it is necessary to return the response 105 to the client node 100 as a result of the task processing (step S708). For example, the task processing unit 205 determines whether or not the task content is satisfied, and in the above-described example, whether or not the temperature is 40 degrees or higher.

  When it is determined that the response 105 needs to be returned to the client node 100 (step S708: YES), the task processing unit 205 returns the response 105 to the client node 100 (step S710). For example, when the task processing unit 205 determines that the task content is satisfied, in the above-described example, the task processing unit 205 determines that the response 105 needs to be returned to the client node 100 when the temperature reaches 40 degrees or more.

  On the other hand, when it is not determined that it is necessary to respond to the client node 100 (step S708: NO) and when a response is returned to the client node 100 in step S710 (step S710), the task processing unit 205 continues to process the task request. It is determined whether or not it is necessary to do this (step S712). For example, when the task processing unit 205 determines that the task content is not satisfied, in the above-described example, if the temperature is not 40 degrees or higher, the task processing unit 205 determines that it is not necessary to return the response 105 to the client node 100.

  If it is determined that it is necessary to continue processing the task request (step S712: YES), the task processing unit 205 transmits a task request message to the next sensor node according to the sensor node processing order (step S714). Next, the process returns to step S706.

  On the other hand, if it is determined that it is not necessary to continue processing the task request (step S712: NO), the processing ends.

  In this way, a given task can be executed cooperatively by a plurality of sensor nodes.

  Next, a method for executing a task schedule will be described with reference to FIG.

  As an example, a case will be described in which task processing is executed by n sensor nodes (n is an integer of n> 1).

From client node 100, a task request is transmitted to the sensor node 200 ₁ (step S902).

Next, the sensor node 200 _1, from the requested task, performs predetermined processing described above, makes decisions task processing system in accordance with the task processing system determines the task processing request message (step S904), the task The request processing message is transmitted to any one of the other sensor node groups 200 ₂ to 200 _n (step S906).

  The sensor node 200 that has received the task request processing message performs task processing according to the task request processing message (step S908), and returns a response to the client node 100 as necessary (step S910).

  Also, the sensor node processing order, task content, and task processing schedule of the task request processing message need only be transmitted for the first time if they are cached in each sensor node. Only the task ID may be notified.

  According to the present embodiment, each sensor node determines a resource necessary for the requested task and determines a necessary processing method. As a result, the corresponding task can be processed in cooperation by a plurality of sensor nodes. Therefore, it is possible to perform more task processing with one sensor node.

  Further, according to the present embodiment, each sensor node can grasp the conditions necessary for processing the requested task. For this reason, each sensor node can determine a processing method for executing a task in a coordinated manner.

  Further, according to the present embodiment, each sensor node can obtain an appropriate method for cooperatively executing a given task by a plurality of sensor nodes. For this reason, it becomes possible to perform task processing in cooperation with a plurality of sensor nodes.

  Further, according to the present embodiment, a given task can be executed in cooperation with a plurality of sensor nodes. For this reason, it is possible to reduce the processing cost executed by one sensor.

  The communication node, sensor network system, and task processing method according to the present invention can be applied to a sensor network system.

It is explanatory drawing which shows the sensor network system concerning one Example of this invention. It is a block diagram which shows the sensor node concerning one Example of this invention. It is a flowchart which shows operation | movement of the sensor node concerning one Example of this invention. It is explanatory drawing which shows the division of a task. It is a flowchart which shows operation | movement of the sensor node concerning one Example of this invention. It is explanatory drawing which shows an example of the scheduling of a task. It is explanatory drawing which shows an example of the scheduling of a task. It is explanatory drawing which shows an example of the scheduling of a task. It is explanatory drawing which shows an example of the scheduling of a task. It is a flowchart which shows operation | movement of the sensor node concerning one Example of this invention. It is explanatory drawing which shows a task request processing message. It is explanatory drawing which shows a task request processing message. It is a flowchart which shows operation | movement of the sensor network system concerning one Example of this invention.

Explanation of symbols

100 Client node 200 ₁ , 200 ₂ , 200 ₃ , 200 ₄ , 200 ₅ , 200 Sensor node

Claims (5)

The communication nodes that make up the sensor network system:
Task determination means for determining resources necessary for task processing based on the task processing request;
Processing method determination means for determining a processing method of a task based on the necessary resources;
Task processing means for performing task processing in accordance with the processing method;
A communication node comprising: In the communication node according to claim 1:
The communication node characterized in that the task determination means grasps at least one of a sensor type, a processing condition, and an observed event from the content of the task requested to be processed. In the communication node according to claim 1 or 2:
The processing method determining means determines the number of communication nodes required for task processing and the task processing execution schedule based on other tasks being executed in the own communication node. A sensor network system composed of multiple communication nodes:
The communication node is
Task determination means for determining resources necessary for task processing based on the task processing request;
Processing method determination means for determining a processing method of a task based on the necessary resources;
Task processing means for performing task processing in accordance with the processing method;
A sensor network system comprising: A task processing method in a communication node constituting a sensor network system, comprising:
Establishing a connection with another communication node;
A task determination step for determining a resource required for the task processing based on the task processing request;
A processing method determination step of determining a task processing method based on the necessary resources;
A task processing step for performing task processing in accordance with the processing method;
A task processing method characterized by comprising:

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