JP2013239860A - Sink node device, storage server device, data collection system, data collection method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sink node device which allows for instantaneous understanding of the overall trend or characteristics of data sent from all nodes, and to provide a storage server device, a data collection system, a data collection method, and program.SOLUTION: A storage server device allocates the upper limit of bandwidth of a communication path to each sink node device. When the bandwidth required for data transmission exceeds the upper limit at a node, the data thinned-out randomly so as to be confined in the allocated bandwidth is transmitted. When the transmission amount of data decreases and the bandwidth has a margin, the data thus thinned-out is transmitted in random order. In a server receiving data according to such a transmission procedure, reversal of data arrival order or data sampling occur, but congestion is avoided and gradual real time collection of detailed data is possible.

Description

  The present invention relates to a sink node device in which the amount of data transmitted via a communication path varies depending on conditions, a storage server device that accumulates data from the sink node device, a data collection system including these, a data collection method thereof, and these Regarding the program.

  With the advancement of sensor network technology, monitoring of real-world environments and situations using sensors has begun to spread. Sensor network monitoring can be applied in a wide range of fields, including earthquake monitoring, building structure monitoring, blood pressure and heart rate monitoring, and farm monitoring. It is considered that more sensors will be arranged in the future. In this specification, a system and a method for collecting a plurality of data in one place using a network are described as a “data collection system” and a “data collection method”, respectively.

  There are two types of monitoring by the sensor network: one in which the sink node device continuously transmits sensor data, and the other in which the amount of sensor data to be transmitted is changed under certain conditions. As an example of the latter, a sink node device equipped with an acceleration sensor normally senses and transmits sensor data at a low sampling rate, but senses and transmits sensor data at a high sampling rate only when an earthquake is detected. Such an earthquake monitoring system. The present invention is intended for the latter in which the data transmission amount of the sink node device varies.

  In such an environment where the data transmission amount from the sink node device fluctuates, when the acquired sensor data is stored in the storage server device, access of write requests to the storage server device is concentrated and congestion may occur. In the example of the previous earthquake monitoring, although the acceleration at the time of the earthquake is high in importance, data accumulation is delayed due to congestion, and it takes time until the data can be referred to.

  Random Early Detection (RED) (for example, refer nonpatent literature 1) is mentioned as a prior art for avoiding congestion. The RED can shift the TCP retransmission timing by discarding the packet from the sink node device based on the probability. However, since processing is performed in order from the oldest transmission request, it takes time to refer to the latest sensor data. Is difficult to solve.

Sally Floyd and Van Jacobson, Random early detection gateways for consonance aviation, IEEE / ACM Transactions on Networking (TON) 4, Vol. 397-413, 1993.

  For monitoring applications using sensor networks, it is desirable to collect and grasp the status of observation objects as soon as possible. However, in the conventional data collection system, since it is assumed that the sink node device transmits in order from the oldest transmission request, it takes time until the storage server device collects the latest sensor data. When performing seismic monitoring with a conventional data collection system, if congestion occurs when an earthquake occurs over a wide area, the sink node device transmits the sensor data of the main motion after that because the sink node device transmits in order from the initial tremor sensor data. There is a large delay before the server device collects. As described above, the conventional data collection system has a problem that it is difficult to immediately grasp to what extent an event targeted for observation is detected in the sensor network.

  In consideration of such circumstances, the present invention is intended to solve the above problem, and its purpose is a sink node device capable of immediately grasping the overall trend and characteristics of the measurement target, A storage server device, a data collection system, a data collection method, and a program are provided.

  In order to solve the above-described problems, the present invention adopts a data transmission order that allows even old data to new data to be collected evenly, and improves the real-time property of the data collected from the sink node device. Specifically, when transmitting data from a distributed sink node device to a storage server device, when the transmission of the amount of data to be transmitted is required due to communication resource restrictions, the present invention Data is thinned out at random and transmitted so that the latest data is collected in the storage server device. The thinned data is transmitted when the bandwidth is available.

  A data collection system according to the present invention includes a sink node device described below, a storage server device, and a communication path connecting them.

A sink node device according to the present invention is a sink node device in which the amount of transmission data per unit time varies according to a predetermined condition,
A communication unit for transmitting transmission data;
A transmission buffer for temporarily storing transmission data;
An upper limit of transmission data amount per unit time that can be transmitted from the communication unit is set,
When the transmission data amount per unit time exceeds the upper limit, the transmission data is thinned out and delivered to the transmission unit so that the transmission data amount per unit time is within the upper limit, and the thinned transmission data is sent to the transmission buffer unit. Delivered to
When the amount of transmission data per unit time is less than the upper limit, the latest transmission data is delivered to the transmission unit, and the transmission data stored in the transmission buffer unit is extracted so as not to exceed the upper limit, and delivered to the transmission unit. A transmission control unit;
Is provided.

A data collection method according to the present invention is a data collection method for transmitting data to a storage server device using a sink node device in which a transmission data amount per unit time varies according to a predetermined condition,
In the sink node device, an upper limit of the amount of transmission data per unit time that can be transmitted to the storage server device is set,
When the amount of transmission data per unit time exceeds the upper limit, the sink node device transmits the thinned transmission data by thinning out the transmission data so that the amount of transmission data per unit time falls within the upper limit. Store in the buffer,
When the transmission data amount per unit time is less than the upper limit, the transmission data stored in the transmission buffer unit is extracted and transmitted together with the latest transmission data so as not to exceed the upper limit.

  When transmitting the transmission data to the storage server device, the sink node device transmits the transmission data by thinning out the transmission data so that the transmission data amount per unit time falls below the preset bandwidth. Send data when bandwidth is available. By adopting such a transmission method, this sink node device continues to send the latest data at a sampling rate commensurate with the bandwidth, and stably transmits the thinned data accumulated in the buffer. Realize that. That is, the storage server device can collect rough data from many sink node devices instantly, and can collect detailed data after a sufficient bandwidth is generated.

  Therefore, the present invention can provide a sink node device and a data collection method that can immediately grasp the overall trend and characteristics of the measurement target.

  The transmission control unit of the sink node device according to the present invention is characterized in that transmission data to be thinned out is selected at random. Also, the data collection method according to the present invention is characterized in that the transmission data to be thinned out is selected at random. By randomly thinning out the transmission data, it is possible to alleviate the deviation of the transmitted data with respect to the time axis, and improve the accuracy of the overall tendency grasped by the storage server device.

  The transmission control unit of the sink node device according to the present invention is characterized in that transmission data is randomly extracted from the transmission buffer unit. The data collection method according to the present invention is characterized in that transmission data is randomly extracted from the transmission buffer unit. In the present invention, the sink node device transmits the data stored in the buffer to the storage server device in a random order, so that old data to new data can be collected uniformly and the data can be refined step by step. .

  The transmission buffer unit of the sink node device according to the present invention has a plurality of write areas, writes the transmission data thinned out by the transmission control unit to the write area selected at random, and the transmission control unit Is characterized by sequentially selecting the write area of the transmission buffer unit to extract transmission data. Further, in the data collection method according to the present invention, the transmission buffer unit has a plurality of write areas, the thinned transmission data is written in the randomly selected write area, and the write of the transmission buffer unit is performed. It is characterized in that the transmission data is extracted by selecting the areas sequentially.

  When sending transmission data thinned out to multiple write areas at random, and sending input data in a predetermined order from the write area, when sending detailed data step by step from the sink node device to the storage server device Data transmission in a random order is possible. Further, by writing data to a randomly selected area among a plurality of buffer writing areas and setting the data transmission unit to the size of the buffer writing area, fragmentation of data in the disk can be prevented.

  The storage server device according to the present invention includes a receiving unit that receives transmission data from the sink node device, a storage unit that accumulates transmission data received by the receiving unit, and the sink node device thins out transmission data. And an estimation unit that estimates transmission data temporarily stored in the transmission buffer unit of the sink node device based on transmission data received by the reception unit. In the data collection method according to the present invention, when the sink node device is thinning out the transmission data, the storage server device receives the transmission data temporarily stored in the transmission buffer unit of the sink node device. The estimation is based on transmission data.

  The storage server device can immediately grasp the overall trend and characteristics by estimating the transmission data from which the estimation unit is thinned based on the received transmission data. Therefore, the present invention can provide a storage server device that can immediately grasp the overall trend and characteristics of the measurement target.

  The program according to the present invention can cause a computer to function as the sink node device or the storage server device.

  The present invention can provide a sink node device, a storage server device, a data collection system, a data collection method, and a program that can immediately grasp the overall trend and characteristics of the measurement target.

It is a figure explaining the data collection system which concerns on this invention. It is a figure explaining the sink node apparatus which concerns on this invention. It is a figure explaining the storage server apparatus concerning this invention. It is a figure explaining the thinning-out operation | movement of the transmission data which the sink node apparatus concerning this invention performs. It is a figure explaining the estimation operation | movement of the data which the storage server apparatus based on this invention performs. It is a figure explaining the data collection method which concerns on this invention. It is a figure explaining the write-in area | region of the sink node apparatus which concerns on this invention.

  Embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below are examples of the present invention, and the present invention is not limited to the following embodiments. In the present specification and drawings, the same reference numerals denote the same components.

  FIG. 1 is an overall view of the data collection system 301. The data collection system 301 includes a sink node device 20, a storage server device 10, and a communication path 30 that connects the sink node device 20 and the storage server device 10. The sink node device 20 is connected to the input device 40 and transmits data input from the input device 40 to the storage server device 10. The storage server device 10 collects transmission data sent from one or more sink node devices 20. In the data collection system 301, the sink node device 20 mainly performs congestion control in this collection process.

  FIG. 2 is a configuration diagram of the sink node device 20. The sink node device 20 is a sink node device in which the amount of transmission data per unit time varies according to a predetermined condition. The sink node device 20 has a communication unit 21 that transmits transmission data, a transmission buffer unit 22 that temporarily stores transmission data, and an upper limit of the amount of transmission data that can be transmitted from the communication unit 21 per unit time. When the transmission data amount per unit time exceeds the upper limit, the transmission data is thinned out and delivered to the transmission unit 21 so that the transmission data amount per unit time is within the upper limit, and the thinned transmission data is transmitted to the transmission buffer unit 22. When the amount of transmission data per unit time is less than the upper limit, the latest transmission data is delivered to the transmission unit 21 and the transmission data stored in the transmission buffer unit 22 is extracted so as not to exceed the upper limit. And a transmission control unit 23 to be delivered to 21.

  The data collection system 301 performs a data collection method for transmitting data to the storage server device 10 using the sink node device 20 in which the transmission data amount per unit time varies according to a predetermined condition. FIG. 6 is a diagram illustrating signal exchange between the sink node device and the storage server device, explaining the data collection method. In the data collection method, an upper limit of the transmission data amount per unit time that can be transmitted to the storage server device 10 is set in the sink node device 20, and when the transmission data amount per unit time exceeds the upper limit, the unit Transmission data is thinned and transmitted so that the amount of transmission data per time is within the upper limit, the thinned transmission data is stored in the transmission buffer unit 22, and when the amount of transmission data per unit time is less than the upper limit, In this method, the transmission data stored in the transmission buffer unit 22 is extracted and transmitted together with the latest transmission data so as not to exceed the upper limit.

  In the present embodiment, the input data input from the input device 40 to the sink node device 20 is data whose data amount varies depending on conditions. In particular, in the present embodiment, the data is acquired from a sensor that can change the measurement frequency of the value. FIG. 4 shows an example of input data. The input data is a target of various data satisfying the above characteristics, and is not limited to sensor data. Specific examples include temperature, humidity, current or voltage values, fluid flow rates, substance concentrations, brightness, noise, position, acceleration, images, and other values measured by sensor devices. Further, the information is not limited to this, and may be information acquired via, for example, the Web or the Internet other than the sensor. Furthermore, in addition to these values, information including metadata indicating sensor characteristics and states, measurement date and time, and the like may be used.

  Considering both the communication path 30 to the storage server device 10 and the data storage performance of the storage server device 10, the sink node device 20 is set in advance with an upper limit value of the transmission bandwidth that does not cause congestion.

  The transmission control unit 23 includes an immediate transmission determination unit 23a and a slow transmission determination unit 23b. When the input data input from the input device 40 can be transmitted in an amount that is less than the set upper limit value of the bandwidth, the immediate transmission determining unit 23a stores the input data without thinning out or storing the input data in the transmission buffer unit 22. It transmits to the server apparatus 10 as transmission data.

  The immediate transmission determining unit 23a of the transmission control unit 23 selects transmission data to be thinned out at random. If the input data from the input device 40 increases and if the transmitted data exceeds the upper limit of the set bandwidth, the immediate transmission determining unit 23a randomly thins out the transmission data and transmits it. . Specifically, as shown in FIG. 4, the immediate transmission determination unit 23 a randomly thins out data input from the input device 40 and stores it in the transmission buffer unit 22, and immediately stores the data that has not been thinned out. Transmission is performed from the communication unit 21. The rate at which data is thinned out at random can be determined based on an amount less than the bandwidth allocated from the storage server device 10 to the sink node device 20, for example. In this way, the sink node device 20 can uniformly transmit the old data to the new data to the storage server device 10 by thinning out the input data at random.

  FIG. 3 is a configuration diagram of the storage server device 10. The storage server device 10 includes a receiving unit 11 that receives transmission data from the sink node device 20, a storage unit 12 that accumulates transmission data received by the receiving unit 11, and a sink node device 20 that has thinned transmission data. And an estimation unit 13 that estimates transmission data temporarily stored in the transmission buffer unit 22 of the sink node device 20 based on the transmission data received by the reception unit 11.

  In the data collection method performed by the data collection system 301, when the sink node device 20 is thinning out the transmission data, the reception unit 11 receives the transmission data temporarily stored in the transmission buffer unit 22 of the sink node device 20. The estimation unit 13 estimates based on the data.

  FIG. 5 illustrates an example in which the estimation unit 13 performs interpolation processing on the waveform of the sensor data input to the sink node device 20 based on the transmission data received by the reception unit 11. That is, the overall tendency and characteristics of the data can be immediately grasped in real time from the transmission data received by the storage server device 10. Note that the overall trend and characteristics are not limited to waveform interpolation because the analysis result of the thinned data is the target. As a specific example, the analysis may include an average value, a variance value, a frequency component, frequent pattern extraction, and similar pattern search.

  The transmission control unit 23 takes out transmission data from the transmission buffer unit 22 at random. As shown in FIG. 6, in the sink node device 20, the amount of input data from the input device 40 is reduced, and a margin is generated in the bandwidth, and then the delayed transmission determination unit 23b transmits the transmission stored in the transmission buffer unit 22. Data is taken out in random order and transmitted from the communication unit 21. By transmitting the transmission data stored in a random order, the storage server device 10 can collect all the old data to new data evenly and can refine the data step by step.

  Such random transmission usually causes disk fragmentation. For this reason, the transmission buffer unit 22 has a plurality of write areas, and the transmission data thinned out by the transmission control unit 23 is written in a randomly selected write area. The write area is sequentially selected and the transmission data is taken out. As shown in FIG. 7, the transmission buffer unit 22 has N write areas (N = 3 in FIG. 7), and stores the thinned transmission data at the end of a randomly selected write area series. To do. The stored transmission data is taken out for each writing area by the slow transmission determining unit 23b after a margin is generated in the bandwidth. That is, the slow transmission determining unit 23b takes the transmission unit of the transmission data as the size of the write area, and takes out the transmission data by changing the transmission unit step by step according to the transmittable bandwidth. For example, if the amount of data stored in the transmission buffer unit 22 is X, the transmission unit is X / N.

  As described above, the data collection system 301 can collect detailed data step by step in real time while avoiding congestion in a node where the amount of data transmitted via the communication path 30 varies depending on conditions.

  The data collection system 301 can be realized using a computer. Specifically, computers can be connected via a communication path, and a program can be executed by one computer and function as the storage server device 10, and a program can be executed by another computer and function as the sink node device 20. .

The following is a summary of the data collection system of this embodiment.
(Task)
In an environment where there are one or more nodes in which the amount of data transmitted via a communication path varies depending on conditions, congestion of the communication path due to a sudden increase in the amount of data transmission is a problem. In the conventional congestion control technique, since each node transmits in order from the oldest data, it takes time to receive and accumulate the latest data from all nodes. That is, it was difficult to immediately grasp the overall trend and characteristics of data sent from all nodes.

(Constitution)
Therefore, the data collection system of this embodiment has the following configuration.
(1)
This is a data collection system in which one or more sink node devices whose transmission data amount varies depending on conditions are connected to the storage server device via a network, and the storage server device collects data from the sink node device via the network. And
The storage server device
A communication unit for receiving data from the sink node device;
A storage unit for storing received data;
With
The sink node device
A communication unit that transmits data to the storage server device via the network with a bandwidth lower than a value set based on an available bandwidth;
An immediate transmission determining unit that preferentially thins out the latest data to an amount that can send data within the bandwidth constraint, and determines data to be transmitted immediately;
A transmission buffer unit for storing the thinned data;
A slow transmission determining unit that determines transmission of data stored in the transmission buffer unit;
A data collection system comprising:

(2)
The sink node device has a function of randomly selecting data to be transmitted immediately by the immediate transmission determination unit, according to (1) above.

(3)
The sink node device has a function of randomly selecting data to be transmitted from the transmission buffer unit by the slow transmission determination unit, wherein the data collection system according to (1) or (2) above.

(4)
The sync node device randomly selects and writes one of a plurality of buffer write areas to the transmission buffer unit, and sequentially reads one of the buffer write areas when the slow transmission determination unit determines transmission The data collection system according to (3), further including a function of selecting data at random.

  The storage server device assigns an upper limit of the bandwidth of the communication path to each sink node device. When the bandwidth required for data transmission by the node exceeds the upper limit, data which is thinned out at random so as to be within the allocated bandwidth is transmitted. After the amount of data transmission is reduced and there is room in bandwidth, the thinned data is transmitted in a random order. With such a transmission procedure, in the server that receives the data, the data arrival order is reversed and the data sampling occurs, but congestion can be avoided and detailed data can be collected in stages in real time.

(effect)
The data collection system of the present embodiment realizes congestion avoidance and real-time detailed data collection in an environment where one or more nodes where the amount of data transmitted via a communication path varies depending on conditions, There is an effect that the overall tendency and characteristics of data sent from all nodes can be immediately grasped.

10: Storage server device 11: Receiving unit 12: Storage unit 13: Estimating unit 20: Sink node device 21: Transmitting unit 22: Transmission buffer unit 23: Transmission control unit 23a: Immediate transmission determining unit 23b: Late transmission determining unit 30: Communication path 40: Input device 301: Data collection system

Claims (13)

A sink node device in which the amount of transmission data per unit time varies according to a predetermined condition,
A communication unit for transmitting transmission data;
A transmission buffer for temporarily storing transmission data;
An upper limit of transmission data amount per unit time that can be transmitted from the communication unit is set,
When the transmission data amount per unit time exceeds the upper limit, the transmission data is thinned out and delivered to the transmission unit so that the transmission data amount per unit time is within the upper limit, and the thinned transmission data is sent to the transmission buffer unit. Delivered to
When the amount of transmission data per unit time is less than the upper limit, the latest transmission data is delivered to the transmission unit, and the transmission data stored in the transmission buffer unit is extracted so as not to exceed the upper limit, and delivered to the transmission unit. A transmission control unit;
A sink node device comprising:   The sink node device according to claim 1, wherein the transmission control unit randomly selects transmission data to be thinned out.   The sink node device according to claim 1 or 2, wherein the transmission control unit randomly extracts transmission data from the transmission buffer unit. The transmission buffer unit has a plurality of write areas, writes the transmission data thinned out by the transmission control unit to the write area selected at random,
The sink node apparatus according to claim 3, wherein the transmission control unit sequentially selects the write area of the transmission buffer unit and extracts transmission data. A receiving unit for receiving transmission data from the sink node device according to any one of claims 1 to 4;
A storage unit for accumulating transmission data received by the receiving unit;
An estimation unit that estimates transmission data temporarily stored in the transmission buffer unit of the sink node device based on transmission data received by the reception unit when the sink node device is thinning out transmission data;
A storage server device comprising: A sink node device according to any one of claims 1 to 4;
A storage server device according to claim 5;
A communication path connecting the sink node device and the storage server device;
A data collection system comprising: A data collection method for transmitting data to a storage server device using a sink node device in which a transmission data amount per unit time varies according to a predetermined condition,
In the sink node device, an upper limit of the amount of transmission data per unit time that can be transmitted to the storage server device is set,
When the amount of transmission data per unit time exceeds the upper limit, the sink node device transmits the thinned transmission data by thinning out the transmission data so that the amount of transmission data per unit time falls within the upper limit. Store in the buffer,
A data collection method for extracting and transmitting transmission data stored in the transmission buffer unit together with the latest transmission data so as not to exceed the upper limit when the transmission data amount per unit time is less than the upper limit.   The data collection method according to claim 7, wherein transmission data to be thinned out is selected at random.   The data collection method according to claim 7 or 8, wherein transmission data is randomly extracted from the transmission buffer unit. The transmission buffer unit has a plurality of write areas, and the thinned transmission data is written in the randomly selected write area,
The data collection method according to claim 9, wherein transmission data is extracted by sequentially selecting the write area of the transmission buffer unit.   When the sink node device thins out transmission data, the transmission data stored temporarily in the transmission buffer unit of the sink node device is estimated based on the transmission data received by the storage server device. The data collection method according to claim 7.   A program for causing a computer to execute the data collection method according to claim 7.   The program for making a computer perform the data collection method of Claim 11.

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