JP2020155889A - Radio quality analyzer, radio quality analysis method, and program - Google Patents

Abstract

To provide a radio quality monitoring device that corrects time lag between time-series data obtained by a plurality of sensor nodes and allows time-series data with time lag corrected to be integrally analyzed on the same time axis.SOLUTION: A radio quality analyzer 100 sets two sensor devices as a master and a slave and adjusts time information of another piece of header data so as to align it with one time axis based on time information of header information about a frame commonly received by both sensors. This allows the header information of the header data acquired by the two sensor devices which are objects of the processing to be expressed on the same time axis.SELECTED DRAWING: Figure 2

Description

The present invention relates to wireless communication technology, and more particularly to wireless quality monitoring technology.

The introduction of IoT (Internet of Things) devices into indoor environments such as factories, hospitals, and commercial facilities is progressing for the purpose of grasping and controlling the operating status of various devices.

For example, when wireless communication is used for state management and control of a manufacturing system in an environment such as a factory, if communication is interrupted due to the effects of radio wave attenuation or interference, the manufacturing process will be delayed or stopped. It may lead to. Therefore, particularly high quality is required for wireless communication.

It is desired to build a system for monitoring whether there is a problem with wireless quality and, if there is a problem, providing information that can identify the cause.

When the space to be monitored is large or there are various obstacles, it is difficult for a single sensor node to cover the entire target space. Therefore, sensor nodes are installed at various points in the target space. There is a demand to understand the radio quality in the target space by installing it and analyzing the data collected from these multiple sensor nodes in an integrated manner.

For example, Patent Document 1 provides a system that receives a test frame transmitted to measure the wireless communication quality, evaluates the wireless communication quality from the received signal strength, and stores the evaluation result in a database. It is disclosed.

Japanese Unexamined Patent Publication No. 2015-33069

However, in the above technique, since the problem of clock deviation between time series data is not taken into consideration, it is difficult to grasp the radio quality of the target space with high accuracy.

Generally, since there is a deviation in the clock managed by each sensor node, there is a time deviation between the time series data acquired by a plurality of sensor nodes. It is difficult to comprehensively analyze the radio quality of the target space using the data in which such a time lag occurs.

Therefore, in view of the above problems, the present invention corrects the time lag between the time series data acquired by the plurality of sensor nodes, and integrates the time series data obtained by correcting the time lag on the same time axis. The purpose is to realize a wireless quality monitoring system, a wireless quality analyzer, a wireless quality analysis method and a program that enable analysis.

In order to solve the above problems, the first invention is a wireless quality analyzer used in a wireless quality monitoring system including a plurality of sensor devices, which includes a header data collection unit, a master-slave selection unit, and a data acquisition unit. A first correction processing unit, a second correction processing unit, a correction time-series data acquisition unit, and an analysis unit are provided.

The header data collecting unit collects header data, which is time-series data including a plurality of header information acquired from frames received by each sensor device, from a plurality of sensor devices. The header information includes at least time information for specifying the transmission start time of the frame from which the header information is extracted.

The master-slave selection unit selects one of the plurality of sensor devices as the master device, and selects a sensor device other than the device selected as the master device among the plurality of sensor devices as the slave device.

The data acquisition unit acquires the header data acquired by the sensor device selected as the master device by the master-slave selection unit as the master header data, and is acquired by the sensor device selected as the slave device by the master-slave selection unit. Acquire header data as slave header data.

The first correction processing unit uses the header information included in the slave header data as the slave side header information, which is the header information acquired from the same frame as the frame in which the master side header information which is the header information included in the master header data is acquired. By setting the time information of the slave side header information extracted as the time information of the master side header information acquired from the same frame as the frame in which the slave side header information was acquired, the time of the slave side header information is set. The first correction process for correcting the information is executed.

Regarding the slave side header information that was not the target of the first correction processing, the second correction processing unit sets the transmission start time of the frame from which the slave side header information is acquired and the slave side header that is the target of the first correction processing. The slave-side header information having the smallest time difference from the transmission start time of the frame for which the information has been acquired is selected from the slave-side header information that is the target of the first correction process. Then, the second correction processing unit uses the selected slave-side header information as the slave-side reference header information, and the time information corrected by the first correction processing of the slave-side reference header information and the time of the slave-side reference header information. A second correction process that corrects the time information of the slave side header information that was not the target of the first correction process based on the time difference between the information and the time information of the slave side header information that was not the target of the first correction process. To execute.

The correction time series data acquisition unit is based on the master header data and the slave header data whose time information has been corrected by the first correction process and the second correction process, and the time information of each header information is the time on the same time axis. The header data adjusted so as to be obtained as the corrected time series data.

The analysis unit performs analysis processing on the quality of the wireless environment in which the sensor device is installed based on the corrected time series data.

In this wireless quality analyzer, two sensor devices are set as a master and a slave, and the other header data is aligned with one time axis based on the time information of the header information about the frame commonly received by both. Adjust the time information (time series data of header information). As a result, the header information of the header data acquired by the two sensor devices targeted for the above processing can be expressed on the same time axis.

Therefore, in this wireless quality analyzer, the time-series data acquired by a plurality of sensor devices (plurality of sensor nodes) is corrected for the time-series data, and the time-series data after the time-series data is corrected for the same time axis. It becomes possible to analyze in an integrated manner above.

The second invention is the first invention, and the correction time-series data acquisition unit is a set of a master header data and a slave header data whose time information is corrected by the first correction processing and the second correction processing. When multiple pieces are acquired, header information for commonly observed frames is detected, and based on the detected time information of the header information, each header data is included so that the time axis of each header data matches. Correct the time information of the header information.

In this wireless quality analyzer, for the sensor device included in the wireless quality monitoring system, the master / slave pair is changed and the first correction process and the second correction process are repeatedly executed to obtain the master header data and the second correction process. It is possible to acquire a plurality of sets of data with the slave header data whose time information has been corrected by the first correction process and the second correction process. Then, in this wireless quality analyzer, the header data acquired as described above and the header data corrected for the time information are matched as a master / slave pair based on the header data of the sensor device commonly selected. By making it possible, the header data acquired by all the sensor devices can be expressed on the same time axis.

Therefore, in this wireless quality analyzer, the time-series data acquired by a plurality of sensor devices (plurality of sensor nodes) is corrected for the time-series data, and the time-series data after the time-series data is corrected for the same time axis. It becomes possible to analyze in an integrated manner above.

The third invention is the first or second invention, and the header information further includes a retransmission flag, a source MAC address, a destination MAC address, and a sequence number.

The first correction processing unit receives the slave side header information and the master side header information.
In both (1), the retransmission flag is "0", and (2) the source MAC address is the same, and
(3) The destination MAC address is the same, and (3) the sequence number is the same.
In this case, it is determined that the frame from which the slave side header information is acquired and the frame from which the master side header information is acquired are the same frame.

As a result, the slave side header information and the master side header information corresponding to the same frame can be appropriately selected (specified).

The fourth invention is any one of the first to third inventions, in which information about the absolute time is acquired and the time axis of the corrected time series data becomes the time axis defined by the absolute time. A time axis correction unit for correcting the time information of the header information included in the correction time series data is further provided.

As a result, the analysis process can be executed using the corrected time series data on the same time axis defined by the absolute time.

A fifth invention is a wireless quality analysis method used in a wireless quality monitoring system including a plurality of sensor devices, which includes a header data acquisition step, a master-slave selection step, a data acquisition step, and a first correction processing step. , A second correction processing step, a correction time series data acquisition step, and an analysis step are provided.

The header data collection step collects header data, which is time-series data including a plurality of header information acquired from frames received by each sensor device, from a plurality of sensor devices. The header information includes at least time information for specifying the transmission start time of the frame from which the header information is extracted.

The master-slave selection step selects one of the plurality of sensor devices as the master device, and selects a sensor device other than the device selected as the master device among the plurality of sensor devices as the slave device.

In the data acquisition step, the header data acquired by the sensor device selected as the master device by the master-slave selection step is acquired as the master header data, and is acquired by the sensor device selected as the slave device by the master-slave selection step. Acquire header data as slave header data.

In the first correction processing step, the header information acquired from the same frame as the frame from which the master side header information, which is the header information included in the master header data, is acquired, and the header information included in the slave header data is the slave side header information. Extract as. Then, in the first correction processing step, the slave side header information is set to the time information of the master side header information acquired from the same frame as the frame in which the slave side header information is acquired, by setting the time information of the extracted slave side header information. The first correction process for correcting the time information of the side header information is executed.

In the second correction processing step, regarding the slave side header information that was not the target of the first correction processing, the transmission start time of the frame from which the slave side header information was acquired and the slave side header that was the target of the first correction processing are performed. The slave-side header information having the smallest time difference from the transmission start time of the frame for which the information has been acquired is selected from the slave-side header information that is the target of the first correction process. Then, in the second correction processing step, the selected slave side header information is used as the slave side reference header information, the time information corrected by the first correction processing of the slave side reference header information, and the time of the slave side reference header information. A second correction process that corrects the time information of the slave side header information that was not the target of the first correction process based on the time difference between the information and the time information of the slave side header information that was not the target of the first correction process. To execute.

In the correction time series data acquisition step, the time information of each header information is the time on the same time axis based on the master header data and the slave header data whose time information has been corrected by the first correction process and the second correction process. The header data adjusted so as to be obtained as the corrected time series data.

The analysis step performs an analysis process on the quality of the wireless environment in which the sensor device is installed, based on the corrected time series data.

As a result, it is possible to realize a radio quality analysis method having the same effect as that of the first invention.

The sixth invention is a program for causing a computer to execute the radio quality analysis method according to the fifth invention.

Thereby, it is possible to realize a program for causing the computer to execute the radio quality analysis method having the same effect as that of the first invention.

According to the present invention, it is possible to correct the time lag between the time series data acquired by a plurality of sensor nodes and to analyze the time series data corrected for the time lag in an integrated manner on the same time axis. It is possible to realize a wireless quality monitoring system, a wireless quality analyzer, a wireless quality analysis method and a program.

The schematic block diagram of the wireless quality monitoring system 1000 which concerns on 1st Embodiment. The figure which added the observable range of each sensor device to the schematic block diagram of the wireless quality monitoring system 1000 which concerns on 1st Embodiment. The schematic block diagram of the wireless quality analyzer 100 which concerns on 1st Embodiment. The schematic block diagram of the sensor apparatus S_node1 which concerns on 1st Embodiment. A flowchart of processing executed by the wireless quality monitoring system 1000. The flowchart of the first correction process. The flowchart of the second correction process. The figure for demonstrating the 1st correction process. The figure for demonstrating the 1st correction process. The figure for demonstrating the 2nd correction process. The figure which showed the master header data M ₁ and the corrected slave header data Sc ₂ with the time axis aligned. The figure for demonstrating the 1st correction process. The figure for demonstrating the 1st correction process. The figure for demonstrating the 2nd correction process. The figure which showed the master header data M ₂ and the corrected slave header data Sc ₃ with the time axis aligned. The figure which showed the master header data M ₁ , the corrected slave header data Sc ₂ , the master header data M _2, and the corrected slave header data Sc ₃ in time series. The figure which showed the master header data M ₁ , the corrected slave header data Sc ₂ , the master header data M _2, and the corrected slave header data Sc ₃ in time series. The figure which showed the master header data M ₁ , the corrected slave header data Sc _2, and the corrected slave header data S'c ₃ in time series. The figure which showed the master header data M ₁ , the corrected slave header data Sc _2, and the corrected slave header data S'c ₃ in time series. The schematic block diagram of the wireless quality analyzer 100A of the 1st modification of 1st Embodiment. The figure which shows the CPU bus configuration.

[First Embodiment]
The first embodiment will be described below with reference to the drawings.

<1.1: Configuration of wireless quality monitoring system>
FIG. 1 is a schematic configuration diagram of the wireless quality monitoring system 1000 according to the first embodiment.

FIG. 2 is a schematic configuration diagram of the radio quality monitoring system 1000 according to the first embodiment, and is a diagram showing an observable range of each sensor device added.

FIG. 3 is a schematic configuration diagram of the wireless quality analyzer 100 according to the first embodiment.

FIG. 4 is a schematic configuration diagram of the sensor device S_node1 according to the first embodiment.

As shown in FIG. 1, the wireless quality monitoring system 1000 includes a wireless quality analyzer 100 and one or a plurality of sensor devices (in FIG. 1, sensor device S_node1, sensor device S_node2, and sensor device S_node3) and one or more. A plurality of communication devices (in FIG. 1, a communication device RbtA, a communication device RbtB, a communication device RbtC, a communication device RbtD, a communication device RbtE, and a communication device RbtF) are provided.

For convenience of explanation, as shown in FIG. 1, the wireless quality monitoring system 1000 includes three sensor devices, a sensor device S_node1, a sensor device S_node2, and a sensor device S_node3, and includes a communication device RbtA and a communication device RbtB. , Communication device RbtC, communication device RbtD, communication device RbtE, and communication device RbtF are included in the following description. Further, as shown in FIG. 2, (1) the observable range (receivable range of the radio signal) of the sensor device S_node1 is the observable range AR (S_node1), and (2) the observable range of the sensor device S_node2. It is assumed that (the receivable range of the radio signal) is the observable range AR (S_node2), and (3) the observable range of the sensor device S_node3 (the receivable range of the radio signal) is the observable range AR (S_node3). , Will be described below.

The communication device RbtA, the communication device RbtB, and the communication device RbtC are installed in, for example, a narrow space (for example, in a factory). Then, the communication device RbtA, the communication device RbtB, the communication device RbtC, the communication device RbtD, the communication device RbtE, and the communication device RbtF, for example, follow each other according to wireless LAN standards such as IEEE802.11a, b, g, n, ac. Can perform wireless communication. The communication device RbtA, the communication device RbtB, the communication device RbtC, the communication device RbtD, the communication device RbtE, and / or the communication device RbtF are, for example, machine tools with a wireless communication function.

The radio quality analyzer 100 and one or more sensor devices are connected wirelessly or by wire and can communicate with each other.

(1.1.1: Wireless quality analyzer)
As shown in FIG. 3, the wireless quality analyzer 100 includes a first communication interface 11, a first communication processing unit 12, a header data collecting unit 13, an analysis unit 14, and a storage unit St1.

The first communication interface 11 is a communication interface for transmitting / receiving data to / from an external device via, for example, a wired or wireless network. The first communication interface 11 converts the data Da1 output from the first communication processing unit 12 into data Da1_out in a format capable of communicating via a wired or wireless network, and transmits the data Da1_out via the network. Further, the first communication interface 11 receives the data Da1_in via the network. The first communication interface 11 converts the received data Da1_in into data Da1 that can be processed by the first communication processing unit 12, and outputs the data Da1 to the first communication processing unit 12.

When transmitting data to the outside, the first communication processing unit 12 outputs the data Da1 to the first communication interface 11. Further, when the first communication processing unit 12 receives data from the outside, the first communication processing unit 12 inputs the data Da1 from the first communication interface 11. When the first communication processing unit 12 receives the data Da1 including the header data from each sensor device, the first communication processing unit 12 extracts the header data of each sensor device from the data Da1, and uses the extracted data as the header data Da_head as the header data collecting unit. Output to 13.

The header data collecting unit 13 inputs the header data Da_head of each sensor device output from the first communication processing unit 12. The header data collecting unit 13 collects the header data Da_head of the sensor device included in the wireless quality monitoring system 1000, and outputs the collected data to the analysis unit 14 as the collected header data Da_head_all.

The "header data" is information on the header portion of each frame (referred to as "header data") for a sequence of frames obtained by decoding a demoted bit string based on the specifications of the target wireless system (for example, IEEE802.11a, etc.). It refers to time-series data (time-series data composed of a plurality of header information) from which (referred to as "header information") is extracted. The following information is typical information that can be extracted from the header part of each frame.
(1) Frame start time (2) Frame duration (3) Source MAC address (4) Destination MAC address (5) Frame length (number of bytes)
(6) Frame type (for example, beacon, Data, Ac, etc.)
(7) Retransmission flag (8) Sequence number (9) Data rate (for example, 6 Mbps, 54 Mbps, etc.)
Each header information includes, for example, the above information (1) to (9).

The analysis unit 14 inputs the collection header data Da_head_all output from the header data collection unit 13. Then, the analysis unit 14 executes the analysis process based on the collected header data Da_head_all, and outputs the data including the analysis result as the data Da_rst. Further, the analysis unit 14 is connected to the storage unit St1 and stores the processing result data, the intermediate processing result data, and the like in the storage unit St1. Further, the analysis unit 14 reads out the data stored in the storage unit St1 at a predetermined timing.

As shown in FIG. 3, the analysis unit 14 includes a master / slave selection unit 141, a data acquisition unit 142, a first correction processing unit 143, a second correction processing unit 144, and a correction time series data acquisition unit 145. , And an analysis processing unit 146.

The master / slave selection unit 141 acquires the header data Da_head of each sensor device from the collected header data Da_head_all output from the header data collection unit 13, and has two header data Da_heads acquired by each of the two different sensor devices. Judge whether or not. As a result of the determination, when it is determined that there are two header data Da_heads acquired by the two different sensor devices, one of the two different sensor devices is set as the master and the other is set as the slave.

The data acquisition unit 142 acquires master header data and slave header data from the collection header data Da_head_all output from the header data collection unit 13. Specifically, the data acquisition unit 142 uses (1) header data acquired by the sensor device set as the master by the master / slave selection unit 141 as master header data, and (2) master / slave selection unit 141. The header data acquired by the sensor device set as the slave is acquired as slave header data.

The first correction processing unit 143 executes the first correction processing by using the master header data and the slave header data acquired by the data acquisition unit 142. Specifically, the first correction processing unit 143 sets the start time (frame corresponding to the header information) for the header information included in the slave header data in which the header information of the same frame exists in the master header data. The first correction process is executed by correcting the transmission start time).

The second correction processing unit 144 executes the second correction processing based on the master header data and the slave header data acquired by the data acquisition unit 142 and the processing result of the first correction processing. Specifically, the second correction processing unit 144 sets the start time (header information) for the remaining header information included in the slave header data that was not the target of the correction processing in the first correction processing. The second correction process is executed by correcting the transmission start time of the frame corresponding to.

The correction time series data acquisition unit 145 integrates the header data after the time information correction processing acquired by the first correction processing and the second correction processing so that each header information becomes data on the same time axis. By executing, the correction time series data is acquired.

The analysis processing unit 146 executes analysis processing for radio quality based on the correction time series data acquired by the correction time series data acquisition unit 145, and acquires data including the analysis processing result as data D_rst.

The storage unit St1 is connected to the analysis unit 14, and performs data writing / reading processing based on a command from the analysis unit 14.

(1.1.2: Sensor device)
As shown in FIG. 4, the sensor device S_node1 includes an antenna Ant1, an RF processing unit 21, an IQ data acquisition unit 22, a header data acquisition unit 23, and a second communication interface 24.

The antenna Ant1 is an antenna for receiving radio waves (RF signals) radiated (transmitted) from the outside. The antenna Ant1 may be a transmission / reception antenna.

The RF processing unit 21 receives an RF signal from the outside via the antenna Ant1, executes RF processing for reception (RF demodulation processing, AD conversion, etc.) on the received RF signal, and signals after the RF processing. Acquires Sig0 (eg, baseband OFDM signal). Then, the RF processing unit 21 outputs the signal Sigma 0 after the RF processing to the IQ data acquisition unit 22.

The IQ data acquisition unit 22 inputs the signal Sigma 0 output from the RF processing unit 21. The IQ data acquisition unit 22 acquires and acquires the data (I component data) of the I component signal (in-phase component signal) and the data (Q component data) of the Q component signal (orthogonal component signal) from the signal Sigma 0. The data is output as data D1_IQ to the header data acquisition unit 23.

The header data acquisition unit 23 inputs the data D1_IQ output from the IQ data acquisition unit 22. The header data acquisition unit 23 executes demodulation processing on the data D1_IQ, and adjusts to the specifications of the physical layer and MAC layer of the wireless system used (protocol used when the sensor device S_node1 performs wireless communication). Based on this, the bit string acquired by the above demodulation process is interpreted and the header information of each frame is acquired. Then, the header data acquisition unit 23 acquires the time-series data of the header information of each frame acquired by interpreting the bit string as the data D1_head. The header information includes, for example, the information (1) to (9) shown in the above (described in the description of "1.1.1: Wireless quality analyzer").

Then, the header data acquisition unit 23 outputs the data D1_head to the second communication interface 24.

The second communication interface 24 is a communication interface for transmitting / receiving data to / from an external device via, for example, a wired or wireless network. The second communication interface 24 inputs the data D1_head output from the header data acquisition unit 23, converts the data D1_head into data in a format that can be communicated via a wired or wireless network, and transmits the data to the outside (predetermined destination). ..

The sensor device S_node2 and the sensor device S_node3 have the same configuration as the sensor device S_node1.

<1.2: Operation of wireless quality monitoring system>
The operation of the wireless quality monitoring system 1000 configured as described above will be described below with reference to the drawings.

FIG. 5 is a flowchart of processing executed by the wireless quality monitoring system 1000.

FIG. 6 is a flowchart of the first correction process.

FIG. 7 is a flowchart of the second correction process.

Hereinafter, the processing executed by the wireless quality monitoring system 1000 will be described with reference to the flowcharts of FIGS. 5 to 7.

(Step S1):
In step S1, the header data collection process is executed.

Specifically, each sensor device included in the wireless quality monitoring system 1000 acquires header data D1_head by the RF processing unit 21, IQ data acquisition unit 22, and header data acquisition unit 23, and the acquired header data D1_head. Is transmitted from each sensor device to the radio quality analyzer 100 via the second communication interface 24.

The wireless quality analyzer 100 receives data including header data D1_head transmitted from each sensor device via the first communication interface 11, and header data transmitted from each sensor device by the first communication processing unit 12. Is acquired as header data Da_head.

The header data collecting unit 13 of the wireless quality analyzer 100 inputs the header data Da_head of each sensor device output from the first communication processing unit 12. The header data collecting unit 13 collects the header data Da_head of the sensor device included in the wireless quality monitoring system 1000, and outputs the collected data to the analysis unit 14 as the collected header data Da_head_all.

(Steps S2, S3):
The master / slave selection unit 141 of the analysis unit 14 of the wireless quality analyzer 100 acquires the header data Da_head of each sensor device from the collected header data Da_head_all output from the header data collection unit 13, and the two different sensor devices respectively. It is determined whether or not there are two acquired header data Da_head. As a result of the determination, when it is determined that there are two header data Da_heads acquired by the two different sensor devices, one of the two different sensor devices is set as the master and the other is set as the slave (step S2).

Here, the master / slave selection unit 141 sets the header data D_head (S_node1) acquired by the sensor device S_node1 as the master header data, and sets the header data D_head (S_node2) acquired by the sensor device S_node2 as the slave header data. It shall be.

Note that the header data D_head obtained by the sensor device S_nodeX written as header data D_head (S_nodeX), a master header data referred to as master header data _{M X} at the time of setting the sensor device S_nodeX the master device. Further, the slave header data at the time of setting the sensor device S_nodeX to the slave device is denoted as slave header data S _X, denoted the slave header data from which the header information is corrected slave header data Sc _X (hereinafter, the same).

The data acquisition unit 142 of the analysis unit 14 of the wireless quality analyzer 100 is based on the selection result (setting result) of the master device and the slave device by the master / slave selection unit 141.
M ₁ = D_head (S_node1)
S ₂ = D_head (S_node2)
As the master header data and the slave header data are acquired (step S3).

(Step S4):
In step S4, the first correction process is executed.

Specifically, the first correction processing unit 143 of the analysis unit 14 of the wireless quality analyzer 100 has the master header data M ₁ (S_node ₁ ) among the header information included in the slave header data S ₂ (header data of S_node ₂ ). The first correction process is executed for the header data of the same frame in the header data). The first correction process will be described below with reference to the flowchart of FIG.

(Step S41):
In step S41, the first correction processing unit 143 initializes the set C (makes the set C an empty set). The set C is a set of header information in the slave header data used to record the subscripts of which the start time has been corrected.

(Steps S42 to S45):
The first correction processing unit 143 executes the first loop processing (repetitive processing shown as “loop 1” in FIG. 6) (steps S42 to S45) for all the header information included in the master header data. For convenience, each header information included in the master header data is expressed as "h _i ^M " (i: integer, 1 ≤ i ≤ N1, N1: number of header information included in the master header data), and the slave header data. Each header information included in is expressed as "h _j ^S " (j: integer, 1 ≦ j ≦ N2, N2: number of header information included in slave header data).

In step S43, the first correction processing unit 143 determines whether or not the header information of the same frame as the frame including the header information _i ^M exists in the slave header data. Specifically, when the first correction processing unit 143 satisfies all of the following (1) to (4) in the header information h _i ^M of the master header data and the header information h _j ^S of the slave header data. , It is determined that the frame including the header information h _i ^M and the frame including the header information h _j ^S are the same, that is, the header information of the same frame as the frame including the header information h _i ^M exists in the slave header data. To do.
(1) and retransmission flag in the header information _h ^{i M,} and the retransmission flag in the header information _h ^{j S} are both "0".
(2) and the source MAC address in the header information _h ^{i M,} and the source MAC address in the header information _h ^{j S} are the same.
(3) and the destination MAC address in the header information _h ^{i M,} and the destination MAC address in the header information _h ^{j S} are the same.
(4) and sequence number of the header information _h ^{i M,} and the sequence number of the header information _h ^{j S} are the same.

When the first correction processing unit 143 determines that the header information of the same frame as the frame containing the header information h _i ^M exists in the slave header data, the process proceeds to step S44, while the header information h _i ^M is included. If it is determined that the header information of the same frame as the frame does not exist in the slave header data, the process proceeds to step S45.

In step S44, when the frame including the header information h _i ^M and the frame including the header information h _j ^S are the same, the first correction processing unit 143 determines the corrected start time (frame) of the header information h _j ^S. the start time) substituting the header information h _i ^M start time (start time of the frame). That is, the first correction processing unit 143
h _j ^S. cts ₌ ^{h i} M. ts
h _j ^S. cts: header information _h ^{j S} of correction after the start time (start time of the frame)
h _i ^M. ts: Header information _i ^M start time (frame start time)
Executes the process corresponding to.

Further, the first correction processing unit 143 adds the subscript _{j of} the header information h _j ^S determined to be the header information of the same frame as the frame including the header information h _i ^M to the set C. That is, the first correction processing unit 143
C = C∪ {j}
Executes the process corresponding to. Then, the first correction processing unit 143 advances the processing to step S45.

In step S45, the first correction processing unit 143 determines whether or not the first loop processing has been executed for all the header information included in the master header data, and if the header information to be processed still remains, it is determined. The process is returned to step S42, and if there is no header information to be processed yet, the first correction process is terminated and the process proceeds to step S5.

Here, the case shown in FIG. 8 will be described as an example of the first correction process.

FIG. 8 shows in chronological order the frames corresponding to each header information when the master header data is the header data D_head (S_node1) of the sensor device S_node1 and the slave header data is the header data D_head (S_node2) of the sensor device S_node2. It is a diagram. In FIG. 8, the horizontal axis is time, and the frame corresponding to each header information is represented by a rectangle. Then, under the rectangle corresponding to each frame, (1) the type of frame (in the case of data, it is described as "Data", in the case of Ac, it is described as "Ack", and in the case of beacon, it is described as "Beacon"). And (2) information about the source and destination. The source and destination (destination) are "X-> Y" (X: source, Y: destination (destination), and "*" indicate that the destination is arbitrary (for example, broadcast). It is written as)). The same applies to this notation.

In the case of FIG. 8, the master header data M ₁ is
M ₁ = D_head (S_node1) = {h ₁ ^M , h ₂ ^M , ..., h ₇ ^M }
, And the slave header data _S 2 _{_ts_set} is
S ₂ = D_head (S_node1) = {h ₁ ^S , h ₂ ^S , ..., h ₇ ^S }
Is.

Further, in the case of FIG. 8, it will be described below assuming that the frames corresponding to the following header information are the same frame.
Same frame:
(1) Frame corresponding to header information h ₁ ^M and frame corresponding to header information h ₂ ^S (2) Frame corresponding to header information h ₄ ^M and frame corresponding to header information h ₄ ^S (3) Header A frame corresponding to the information h ₆ ^M and a frame corresponding to the header information h ₇ ^{S In} this case, the first correction processing unit 143 determines that the frame is the same as the header information h ₁ ^M of the master header data. About the header information h ₂ ^S in
h ₂ ^S. cts = h ₁ ^M. ts
The processing corresponding to is executed, and the corrected header information h ₂ ^{S is} the corrected start time (frame start time) h ₂ ^S. cts is the start time of the header information h ₁ ^M (frame start time) h ₁ ^M. Set to ts.

Further, the first correction processing unit 143 refers to the header information h ₄ ^S in the slave header data determined to be in the same frame as the header information h ₄ ^M of the master header data.
h ₄ ^S. cts = h ₄ ^M. ts
The processing corresponding to is executed, and the corrected header information h ₄ ^{S is} the corrected start time (frame start time) h ₄ ^S. cts is the start time of the header information h ₄ ^M (frame start time) h ₄ ^M. Set to ts.

Further, the first correction processing unit 143 refers to the header information h ₇ ^S in the slave header data determined to be in the same frame as the header information h ₆ ^M of the master header data.
h ₇ ^S. cts = h ₆ ^M. ts
The processing corresponding to is executed, and the corrected header information h ₇ ^{S is} the corrected start time (frame start time) h ₇ ^S. cts is the start time of the header information h ₆ ^M (frame start time) h ₆ ^M. Set to ts.

Then, the first correction processing unit 143 adds the subscript j of the header information in the slave header data subjected to the above processing to the set C. That is, the first correction processing unit 143 sets the set C to C = {2, 4, 7}.
And.

The state of the above processing is schematically shown in FIG.

As described above, in the case of FIG. 8, the first correction processing unit 143 executes the first correction processing.

(Step S5):
In step S5, the second correction process is executed.

Specifically, the second correction processing unit 144 of the analysis unit 14 of the wireless quality analyzer 100 includes the subscript j in the set C among the header information included in the slave header data S ₂ (header data of S_node2). It is for each header information not h _{j S} ^(each header information was not subjected to the first correction process h _{j ^S),} executes the second correction processing. The second correction process will be described below with reference to the flowchart of FIG. 7.

(Step S51):
In step S51, the second correction processing unit 144, the header information subscript j is not included in the set C h _{j S} a ^(each header information was not subjected to the first correction process h _{j ^S),} the 2 The second loop process (repeated process shown as “loop 2” in FIG. 7) (steps S51 to S56) is executed as the target of the correction process.

に相当する処理を実行して、添え字ｋ＿ｏｐｔを取得する。 (Step S52):
In step S52, the second correction processing unit 144 has the start time h _k ^S. Of the header information h _k ^S for the subscript k included in the set C. ts and header information h _j ^S. Start time before correction h _j ^S. Find the subscript k_opt that minimizes the absolute value of the difference from ts. That is, the second correction processing unit 144

The subscript k_opt is acquired by executing the process corresponding to.

(Steps S53 to S55):
In step S53, the second correction processing unit 144 _determines the start time h _{k_opt} ^S. of the header information h _{k_opt} ^S acquired in step S52. ts and header information _h ^j start time before the correction of ^S _h ^j S. Compare with ts.
(1) h _{k_opt} ^S. ts <h _j ^S. If it is not ts, the second correction processing unit 144
h _j ^S. cts = h _{k_opt} ^S. ts- (h _{k_opt} ^S .ts-h _j ^S .ts)
By executing the process corresponding to, the start time after the correction of the header information h _j ^S is h _j ^S. Acquire cts (step S54). Then, the second correction processing unit 144 advances the processing to step S56.
(2) h _{k_opt} ^S. ts <h _j ^S. In the case of ts, the second correction processing unit 144
h _j ^S. cts = h _{k_opt} ^S. ts + (h _j ^S .ts-h _{k_opt} ^S .ts)
By executing the process corresponding to, the start time after the correction of the header information h _j ^S is h _j ^S. Acquire cts (step S55). Then, the second correction processing unit 144 advances the processing to step S56.

(Step S56):
In step S56, the second correction processing unit 144 determines whether or not the header information to be processed still remains, and if the header information to be processed still remains, returns the processing to step S52 and still If there is no header information to be processed, the second correction process is terminated and the process proceeds to step S6.

Here, the case shown in FIG. 10 will be described as an example of the second correction process. FIG. 10 is a diagram for explaining a second correction process when the same data as in FIG. 8 is used as a processing target.

In the case of FIG. 10, since the set C = {2, 4, 7}, the header information to be the target of the second correction processing is h ₁ ^S , h ₃ ^S , h ₅ ^S , h ₆ ^S.
(1) Regarding the header information h ₁ ^S , among the header information in which the subscript j is included in the set C = {2, 4, 7}, the start time thereof is the start time h ₁ ^S of the header information h ₁ ^S. .. Since the header information having the start time closest to ts is the header information h ₂ ^S , the second correction processing unit 144 sets k_opt = 2. And h _{k_opt} ^S. ts> h _j ^S. Since ts (h ₂ ^S .ts> h ₁ ^S .ts), the second correction processing unit 144
h _j ^S. cts = h _{k_opt} ^S. ts- (h _{k_opt} ^S .ts-h _j ^S .ts)
h ₁ ^S. cts = h ₂ ^S. ts- (h ₂ ^S .ts-h ₁ ^S .ts)
By executing the process corresponding to, the start time after the correction of the header information h ₁ ^S is h ₁ ^S. Get cts.
(2) Regarding the header information h ₃ ^S , among the header information in which the subscript j is included in the set C = {2, 4, 7}, the start time thereof is the start time h ₃ ^S of the header information h ₃ ^S. .. Since the header information having the start time closest to ts is the header information h ₄ ^S , the second correction processing unit 144 sets k_opt = 4. And h _{k_opt} ^S. ts> h _j ^S. Since ts (h ₄ ^S .ts> h ₃ ^S .ts), the second correction processing unit 144
h _j ^S. cts = h _{k_opt} ^S. ts- (h _{k_opt} ^S .ts-h _j ^S .ts)
h ₃ ^S. cts = h ₄ ^S. ts- (h ₄ ^S .ts-h ₃ ^S .ts)
By executing the process corresponding to, the start time after the correction of the header information h ₃ ^S is h ₃ ^S. Get cts.
(3) Regarding the header information h ₅ ^S , among the header information in which the subscript j is included in the set C = {2, 4, 7}, the start time thereof is the start time h ₅ ^S of the header information h ₅ ^S. .. Since the header information having the start time closest to ts is the header information h ₄ ^S , the second correction processing unit 144 sets k_opt = 4. And h _{k_opt} ^S. ts <h _j ^S. Since ts (h ₄ ^S .ts <h ₅ ^S .ts), the second correction processing unit 144
h _j ^S. cts = h _{k_opt} ^S. ts + (h _j ^S .ts-h _{k_opt} ^S .ts)
h ₅ ^S. cts = h ₄ ^S. ts + (h ₅ ^S .ts-h ₄ ^S .ts)
By executing the process corresponding to, the start time after the correction of the header information h ₅ ^S is h ₅ ^S. Get cts.
(4) Regarding the header information h ₆ ^S , among the header information in which the subscript j is included in the set C = {2, 4, 7}, the start time thereof is the start time h ₆ ^S of the header information h ₆ ^S. .. Since the header information having the start time closest to ts is the header information h ₇ ^S , the second correction processing unit 144 sets k_opt = 7. And h _{k_opt} ^S. ts> h _j ^S. Since ts (h ₇ ^S .ts> h ₆ ^S .ts), the second correction processing unit 144
h _j ^S. cts = h _{k_opt} ^S. ts- (h _{k_opt} ^S .ts-h _j ^S .ts)
h ₆ ^S. cts = h ₇ ^S. ts- (h ₇ ^S .ts-h ₆ ^S .ts)
By executing the process corresponding to, the start time after the correction of the header information h ₆ ^S is h ₃ ^S. Get cts.

As described above, in the case of FIG. 10, the second correction processing unit 144 executes the second correction processing.

Thus, the sensor device set the S_node1 the master device, at the time of setting the sensor device S_node2 to the slave device, the header information of the sensor device S_node2 _h ^j start time after correction ^S _h ^j S. Set data of cts Sc ₂ . cts_set can be acquired as the following data. The start time of the corrected header information _h ^{j S} of the sensor device S_nodeX _h ^j S. Set data of cts is set as set data Sc _X. It is expressed as cts_set, and the fact that the master device when the set data is acquired is S_nodeY is indicated as "Sc _X .cts_set.master = S_nodeY" (hereinafter, the same applies).
Sc ₂ . cts_set = {h ₁ ^S. cts, h ₂ ^S. cts, h ₃ ^S. cts, h ₄ ^S. cts, h ₅ ^S. cts, h ₆ ^S. cts, h ₇ ^S. cts}
h ₁ ^S. cts = h ₂ ^S. ts- (h ₂ ^S .ts-h ₁ ^S .ts)
h ₂ ^S. cts = h ₁ ^M. ts
h ₃ ^S. cts = h ₄ ^S. ts- (h ₄ ^S .ts-h ₃ ^S .ts)
h ₄ ^S. cts = h ₄ ^M. ts
h ₅ ^S. cts = h ₄ ^S. ts + (h ₅ ^S .ts-h ₄ ^S .ts)
h ₆ ^S. cts = h ₇ ^S. ts- (h ₇ ^S .ts-h ₆ ^S .ts)
h ₇ ^S. cts = h ₆ ^M. ts
Sc ₂ . cts_set. master = S_node1
11, the start time of a frame of the header information included in the master header data _{M 1} of the master device S_node1 _h ⁱ M. Set data of ts M ₁ . and Ts_set, start time of the corrected frame of each header information of the sensor device S_nod2 _h ^j S. Set data of cts Sc ₂ . The figure which matched the time axis based on cts_set is shown. The set data M ₁ . ts_set is as follows.
M ₁ . ts_set = {h ₁ ^M. ts, h ₂ ^M. ts, h ₃ ^M. ts, h ₄ ^M. ts, h ₅ ^M. ts, h ₆ ^M. ts, h ₇ ^M. ts}
As shown in FIG. 11, in the radio quality analyzer 100, the slave header data is adjusted so that the start times of the header information of the frames commonly included in the master header data M ₁ and the slave header data S ₂ match. By doing so, it is possible to acquire the corrected slave header data Sc ₂ in which the master header data M ₁ and the time axis are matched.

(Step S6):
In step S6, the analysis unit 14 stores the corrected slave header data acquired by the first correction process and the second correction process in the storage unit St1.

(Step S7):
In step S7, the analysis unit 14 determines whether or not there is other data to be processed. Specifically, the analysis unit 14 sets the master device and the slave device, and determines whether or not a set of sensor devices for executing the processes of steps S2 to S6 still remains. As a result of the determination, if there is no set of sensor devices that are set in the master device and the slave device and should execute the processes of steps S2 to S6, the analysis unit 14 advances the process to step S8 and advances the process to the master device and the slave device. If a set of sensor devices for executing the process of steps S2 to S6 remains, the analysis unit 14 returns the process to step S2.

Here, after the processing of steps S2 to S6 is executed with the master device as the sensor device 1 and the slave device as the sensor device 2, there is still a case where the master device is the sensor device 2 and the slave device is the sensor device 3. This case will be described.

FIG. 12 corresponds to each header information when the master header data is the header data D_head (S_node2) of the sensor device S_node2 and the slave header data is the header data D_head (S_node3) of the sensor device S_node3, as in FIG. It is the figure which showed the frame in time series. In the case of FIG. 12, the period during which the header data D_head (S_node2) of the sensor device S_node2 is acquired is the same as the period during which the header data D_head (S_node2) of the sensor device S_node2 shown in the case of FIG. 8 is acquired. It is assumed that.

In the case of FIG. 12, the master header data M ₂ is
M ₂ = D_head (S_node2) = {h ₁ ^M , h ₂ ^M , ..., h ₇ ^M }
, And the slave header data _{S 3} is
S ₃ = D_head (S_node3) = {h ₁ ^S , h ₂ ^S , ..., h ₅ ^S }
Is.

Further, in the case of FIG. 12, it will be described below assuming that the frames corresponding to the following header information are the same frame.
Same frame:
(1) Frame corresponding to header information h ₃ ^M and frame corresponding to header information h ₂ ^S (2) Frame corresponding to header information h ₆ ^M and frame corresponding to header information h ₄ ^{S In} this case, the first 1 The correction processing unit 143 refers to the header information h ₂ ^S in the slave header data determined to be in the same frame as the header information h ₁ ^M of the master header data.
h ₂ ^S. cts = h ₃ ^M. ts
The processing corresponding to is executed, and the corrected header information h ₂ ^{S is} the corrected start time (frame start time) h ₂ ^S. The cts are set to the header information h ₃ ^M start time (frame start time) h ₃ ^M. Set to ts.

Further, the first correction processing unit 143 refers to the header information h ₄ ^S in the slave header data determined to be in the same frame as the header information h ₆ ^M of the master header data.
h ₄ ^S. cts = h ₆ ^M. ts
The processing corresponding to is executed, and the corrected header information h ₄ ^{S is} the corrected start time (frame start time) h ₄ ^S. cts is the start time of the header information h ₆ ^M (frame start time) h ₆ ^M. Set to ts.

Then, the first correction processing unit 143 adds the subscript j of the header information in the slave header data subjected to the above processing to the set C. That is, the first correction processing unit 143 sets the set C to C = {2,4}.
And.

The state of the above processing is schematically shown in FIG.

As described above, in the case of FIG. 12, the first correction processing unit 143 executes the first correction processing.

Next, the second correction processing unit 144 executes the second correction processing.

Here, the case shown in FIG. 14 will be described as an example of the second correction process. FIG. 14 is a diagram for explaining a second correction process when the same data as in FIG. 12 is used as a processing target.

In the case of FIG. 14, since the set C = {2,4}, the header information to be the target of the second correction processing is h ₁ ^S , h ₃ ^S , and h ₅ ^S.
(1) Regarding the header information h ₁ ^S , among the header information in which the subscript j is included in the set C = {2, 4}, the start time is the start time h ₁ ^S of the header information h ₁ ^S. Since the header information having the start time closest to ts is the header information h ₂ ^S , the second correction processing unit 144 sets k_opt = 2. And h _{k_opt} ^S. ts> h _j ^S. Since ts (h ₂ ^S .ts> h ₁ ^S .ts), the second correction processing unit 144
h _j ^S. cts = h _{k_opt} ^S. ts- (h _{k_opt} ^S .ts-h _j ^S .ts)
h ₁ ^S. cts = h ₂ ^S. ts- (h ₂ ^S .ts-h ₁ ^S .ts)
By executing the process corresponding to, the start time after the correction of the header information h ₁ ^S is h ₁ ^S. Get cts.
(2) For the header information _h ^{3 S,} within the header information subscript j is included in the set C = {2,4}, the start time, the start time _h ³ S header information _h ^{3 S.} Since the header information having the start time closest to ts is the header information h ₂ ^S , the second correction processing unit 144 sets k_opt = 2. And h _{k_opt} ^S. ts <h _j ^S. Since ts (h ₂ ^S .ts <h ₃ ^S .ts), the second correction processing unit 144
h _j ^S. cts = h _{k_opt} ^S. ts + (h _j ^S .ts-h _{k_opt} ^S .ts)
h ₃ ^S. cts = h ₂ ^S. ts + (h ₃ ^S .ts-h ₂ ^S .ts)
By executing the process corresponding to, the start time after the correction of the header information h ₅ ^S is h ₃ ^S. Get cts.
(3) For the header information _h ^{5 S,} subscript j is within the header information included in the set C = {2,4}, the start time, the start time _h ⁵ S header information _h ^{5 S.} Since the header information having the start time closest to ts is the header information h ₄ ^S , the second correction processing unit 144 sets k_opt = 4. And h _{k_opt} ^S. ts <h _j ^S. Since ts (h ₄ ^S .ts <h ₅ ^S .ts), the second correction processing unit 144
h _j ^S. cts = h _{k_opt} ^S. ts + (h _j ^S .ts-h _{k_opt} ^S .ts)
h ₅ ^S. cts = h ₄ ^S. ts + (h ₅ ^S .ts-h ₄ ^S .ts)
By executing the process corresponding to, the start time after the correction of the header information h ₅ ^S is h ₅ ^S. Get cts.

As described above, in the case of FIG. 14, the second correction processing unit 144 executes the second correction processing.

Thus, the sensor device set the S_node2 the master device, at the time of setting the sensor device S_node3 to the slave device, the header information of the sensor device S_node3 _h ^j start time after correction ^S _h ^j S. Set data of cts Sc ₃ . cts_set can be acquired as the following data.
Sc ₃ . cts_set = {h ₁ ^S. cts, h ₂ ^S. cts, h ₃ ^S. cts, h ₄ ^S. cts, h ₅ ^S. cts}
h ₁ ^S. cts = h ₂ ^S. ts- (h ₂ ^S .ts-h ₁ ^S .ts)
h ₂ ^S. cts = h ₃ ^M. ts
h ₃ ^S. cts = h ₂ ^S. ts + (h ₃ ^S .ts-h ₂ ^S .ts)
h ₄ ^S. cts = h ₆ ^M. ts
h ₅ ^S. cts = h ₄ ^S. ts + (h ₅ ^S .ts-h ₄ ^S .ts)
Sc ₃ . cts_set. master = S_node2
15, the start time of a frame of the header information included in the master header data _{M 2} of the master device S_node2 _h ⁱ M. Set data of ts M ₂ . and Ts_set, start time of the corrected frame of each header information of the sensor device S_nod3 _h ^j S. Set data of cts Sc ₃ . The figure which matched the time axis based on cts_set is shown. The set data M ₂ . ts_set is as follows.
M ₂ . ts_set = {h ₁ ^M. ts, h ₂ ^M. ts, h ₃ ^M. ts, h ₄ ^M. ts, h ₅ ^M. ts, h ₆ ^M. ts, h ₇ ^M. ts}
As shown in FIG. 15, in the wireless quality analyzer 100, the slave header data is adjusted so that the start times of the header information of the frames commonly included in the master header data M ₂ and the slave header data S ₃ match. By doing so, it is possible to acquire the corrected slave header data Sc ₃ in which the master header data M ₂ and the time axis match.

(Step S8):
In step S8, the correction time series data acquisition unit 145 of the analysis unit 14 of the wireless quality analyzer 100 integrates the master header data acquired in steps S1 to S6 and the corrected slave header data (integration process), that is, , Execute the process of adjusting the time information of each header data so that the data is represented by the same time axis.

This integrated process will be described with reference to FIGS. 16 to 18.

16, (1) the header data of the sensor device S_node1 a master header data (data _{M 1),} the header data of the sensor device S_node2 acquired as a slave header data (data _{S 2),} the corrected sensor device S_node2 The slave header data (data Sc ₂ ) and (2) the header data of the sensor device S_node 2 are used as the master header data (data M ₂ ), and the header data of the sensor device S_node ₃ is acquired as the slave header data (data S ₃ ). , Is the figure which showed the slave header data (data Sc ₃ ) after correction of the sensor device S_node3.

As can be seen from FIG. 16, (1) the header data M ₁ and the header data Sc ₂ have the same time axis, and (2) the header data M ₂ and the header data Sc ₃ have the same time axis. ing. However, the time axes of the header data M ₁ and the header data Sc ₃ do not match.

Therefore, in the wireless quality analyzer 100, the header data of the device commonly selected for either the master device or the slave device in the first correction process and the second correction process twice is based on the header data after the correction. Then, a process (integrated process) of adjusting all the header data acquired by the wireless quality analyzer 100 so that the time axes match is executed.

In the case of FIG. 16, the sensor device S_node2 is selected as the slave device (the master device is the sensor device S_node1) in the first first correction process and the second correction process, and the second first correction process and the second correction process are performed. Since the master device (slave device is the sensor device S_node3) is selected in the correction process, the wireless quality analyzer 100 uses the header data of the sensor device S_node2 and the header data of the sensor device S_node1 based on the corrected header data. The integrated process is executed so that the time information of the data and the time information of the header data of the sensor device S_node3 become the time information on the same time axis.

In the case of FIG. 16, the situation is as follows.
(1) First first correction process, second correction process Master: Sensor device S_node1 (header data M ₁ )
Slave: Sensor device S_node2 (corrected header data Sc ₂ )
(2) Second first correction process, second correction process Master: Sensor device S_node2 (header data M ₂ )
Slave: Sensor device S_node3 (corrected header data Sc ₃ )
Therefore, in this case, in the wireless quality analyzer 100, the corrected header data Sc ₂ (Sc ₂₎ of the sensor device S_node 2 is set as the reference time axis with the time axis defined by the time information of the header data M ₁ of the sensor device S_node ₁ as the reference time axis. and time information .master = S_node1) each header information, the time information by the same time axis and the time information of each header information of the header data _Sc 3 after correction of the sensor device S_node3 _(Sc 2 .master = S_node2) Execute the integration process as follows. The specific processing will be described below.

The correction time series data acquisition unit 145 of the analysis unit 14 refers to the data stored in the storage unit St1 and refers to the data stored in the storage unit St1.
(1) a sensor device S_node1 a master, and the header data _Sc 2 after correction of the sensor device S_node2 sensor device acquired as slave _{S_node2 (Sc 2 .cts_set.master = S_node1)} ,
(2) The corrected header data Sc ₃ (Sc ₃ .cts_set.master = S_node 2) of the sensor device S_node 3 acquired with the sensor device S_node 2 as the master and the sensor device S_node 3 as the slave.
Recognize that is present.

Then, the correction time series data acquisition unit 145 acquires the following data.
(1) Header data Sc ₂ (Sc ₂ .cts_set.master = S_node1)
(Header data _Sc 2 after correction is a sensor device acquires the master device as a sensor device _{S_node1 S_node2 (Sc 2 .cts_set.master = S_node1} ))
(2) Header data M ₂
(Master header data M ₂ equal to the header data D_head (S_node ₂ ) of the sensor device S_node ₂ )
(3) Header data Sc ₃ (Sc ₃ .cts_set.master = S_node2)
(Header data Sc ₃ after correction of the sensor device S_node ₃ acquired with the master device as the sensor device S_node ₂ (Sc ₃ .cts_set. master = S_node 2))
Then, the correction time series data acquisition unit 145 is the processing target of the first correction processing when the master is set to the sensor device S_node2 and the slave is set to the sensor device S_node3 based on the above data (1) to (3). Detects header information. In the case of FIG. 16, the following header information is detected.
(A1) Header information h ₃ ^M of header data M ₂ and header information h ₂ ^{S of} corrected slave header data Sc ₃ (Sc ₃ .cts_set.master = S_node ₂ )
(In the third and fourth rows of FIG. 16, it corresponds to the header information in the area surrounded by the dotted line)
(A2) Header information h ₆ ^M of header data M ₂ and header information h ₄ ^{S of} corrected slave header data Sc ₃ (Sc ₃ .cts_set.master = S_node 2)
(In the third and fourth rows of FIG. 16, it corresponds to the header information in the area surrounded by the dotted line)
The frame corresponding to the header information of the above (A1) is referred to as a frame A1, and the frame corresponding to the header information of the above (A2) is referred to as a frame A2.

Next, the correction time series data acquisition unit 145 detects the header information corresponding to the frame A1 and the frame A2 from the corrected header data Sc ₂ (Sc ₂ .cts_set.master = S_node1). The correction time series data acquisition unit 145, as the header information corresponding to the frame A1, and acquires the header information _h ^{3 S} header data _Sc 2 corrected _(Sc 2 _{.cts_set.master} = S_node1), the frame A2 As the corresponding header information, the header information h ₆ ^S of the corrected header data Sc ₂ (Sc ₂ .cts_set.master = S_node1) is acquired (in the second row of FIG. 16, the header information in the area surrounded by the dotted line). Equivalent to).

Next, the correction time-series data acquisition unit 145 sets the master header data as the corrected header data Sc ₂ (Sc ₂ .cts_set.master = S_node1), and sets the slave header data as the corrected slave header data Sc ₃ (Sc _3). .Cts_set.master = S_node2), and the same process as the first correction process and the same process as the first correction process are executed. That is, in the corrected time series data acquisition unit 145, the time information of each header information of the corrected slave header data Sc ₃ (Sc ₃ .cts_set.master = S_node 2) is the header data M ₁ and the corrected header data. _{Sc 2 (Sc 2 .cts_set.master = S_node1} ) of as defined by the time axis and the same time axis for defining the time information of each header information, it corrects the time information of each header information. That is, as shown in FIGS. 17 and 18, the frame start time of the header information h ₃ ^S corresponding to the frame A1 of the corrected header data Sc ₂ (Sc ₂ .cts_set.master = S_node1) h ₃ ^S. The cts and the header information h ₂ ^S frame start time h ₂ ^S. Corresponding to the frame A1 of the corrected slave header data Sc ₃ (Sc ₃ .cts_set.master = S_node2). The time information is corrected so that it matches with cts.

The header data of the sensor device S_node ₃ after this correction process is set as the header data S'c ₃ , and the frame start time after the correction of each header information h _j ^S of the header data S'c ₃ is h _j ^S. Notated as cts2. Further, each header information of the header data when the sensor device S_nodeX is a slave is referred to as header information h _j ^SX . Therefore, the header data _Sc 2 after correction of the sensor device S_node2 _(Sc 2 .cts_set.master = S_node1) is
Sc ₂ = {h ₁ ^S2 , h ₂ ^S2 , ..., h ₇ ^S2 }
Sc ₂ . cts_set = {h ₁ ^S2 . cts, h ₂ ^S2 . cts, ..., h ₇ ^S2 . cts}
Is.

As shown in FIG. 18, the header data S'c ₃ of the sensor device S_node ₃ after the correction process is as follows.
S'c ₃ . cts2_set = {h ₁ ^S3 . cts2, h ₂ ^S3 . cts2, h ₃ ^S3 . cts2, h ₄ ^S3 . cts2, h ₅ ^S3 . cts2}
h ₁ ^S3 . cts2 = h ₂ ^S3 . cts2- (h ₂ ^S3 .cts-h ₁ ^S3 .cts)
h ₂ ^S3 . cts2 = h ₃ ^S2 . cts
h ₃ ^S3 . cts2 = h ₂ ^S3 . cts2 + (h ₃ ^S3 .cts-h ₂ ^S3 .cts)
h ₄ ^S3 . cts2 = h ₆ ^S2 . cts
h ₅ ^S3 . cts2 = h ₄ ^S. cts2 + (h ₅ ^S3 .cts-h ₄ ^S3 .cts)
S'c ₃ . cts2_set. master_data = Sc ₂ . cts_set
In "S'c ₃ .cts2_set.master_data = Sc ₂ .cts_set", the data used to change the time information of the frame start time of the header data S'c ₃ is the data Sc ₂ . It shows that it is cts_set.

By performing the processing as described above, the wireless quality analyzer 100 acquires the result data of the integrated processing (for example, the data shown in FIG. 18), that is, the data in which the time information of each header information is expressed on the same time axis. can do.

(Step S9):
In step S9, the analysis process is executed. Specifically, the analysis processing unit 146 of the analysis unit 14 of the wireless quality analyzer 100 outputs data (data after integration processing) in which the time information of each header information is expressed by the same time axis acquired in step S8. It is used to analyze the wireless communication environment. For example, in the case shown in FIG. 19, it can be predicted that the sensor device S_node2 cannot receive the Ac transmitted from the communication device C to the communication device B in the area surrounded by the dotted line. That is, from the positional relationship between the sensor device S_node2, the communication device C, and the communication device B (see FIGS. 1 and 2), the frame originally transmitted from the communication device C to the communication device B (FIG. 19). The radio signal including the header information (frame corresponding to h ₃ ^S ₃ ) should be able to be received by the sensor device S_node2. From the data shown in FIG. 19, the sensor device S_node2 is, the frame of the sensor device S_node3 is normally received (Ack, C-> B) successfully receives the (header information _h ³ frames corresponding to ^S3 in Fig. 19) It is possible to properly detect what has not been done.

As described above, in the wireless quality analyzer 100, it is possible to appropriately analyze the wireless communication environment by using the data (data after the integrated processing) in which the time information of each header information is expressed on the same time axis. it can.

As described above, in the wireless quality analyzer 100, two sensor devices are set as the master and the slave, and the time information of the header information about the frame commonly received by both is used as a reference so as to be aligned with one of the time axes. , Adjust the time information of the other header data (time series data of header information). As a result, the header information of the header data acquired by the two sensor devices targeted for the above processing can be expressed on the same time axis. Then, the wireless quality analyzer 100 changes the master / slave pair of the sensor device included in the wireless quality monitoring system 1000, and repeatedly executes the above processing. Then, in the wireless quality analyzer 100, the header data acquired as described above and the header data corrected for the time information are matched as a master / slave pair based on the header data of the sensor devices commonly selected. By making it possible, the header data acquired by all the sensor devices can be expressed on the same time axis.

Therefore, in the wireless quality analyzer 100, the time-series data acquired by the plurality of sensor devices (plurality of sensor nodes) is corrected for the time-series data, and the time-series data after the time-series data is corrected for the same time axis. It becomes possible to analyze in an integrated manner above.

Further, in the wireless quality monitoring system 1000, as described above, the wireless quality analyzer 100 can acquire the time series data represented on the same time axis by using the data collected from the sensor device. There is no need to add hardware or software for time synchronization on the sensor side. That is, in the wireless quality monitoring system 1000, the time between the time series data collected from the sensor device can be aligned only by the processing on the wireless quality analyzer 100 side, so that its usefulness is extremely high.

Further, in the wireless quality monitoring system 1000, if the two sensor devices have a common area where the wireless signal can be received (observable), the monitoring area can be expanded in a Imozuru manner. For example, in the case of FIG. 2, there is an overlap region between (1) the observable range AR (S_node1) of the sensor device S_node1 and the observable range AR (S_node2) of the sensor device S_node2, and (2) the observation of the sensor device S_node2. If there is an overlapping region in the possible range AR (S_node2) and the observable range AR (S_node3) of the sensor device S_node3, the time axes are sequentially matched based on the time information of the frames commonly observed in the overlapping region. The monitoring area (observable area) of the wireless quality monitoring system 1000 is the logical sum of the observable range AR (S_node1), the observable range AR (S_node2), and the observable range AR (S_node3). (Area obtained by adding the above three ranges).

That is, the wireless quality monitoring system 1000 does not need to be provided with a sensor device that covers the entire area used by the wireless quality monitoring system 1000 (can receive (observe) wireless signals), and sets the observable range as described above. By doing so, the monitoring area (observable area) of the wireless quality monitoring system 1000 can be easily expanded.

≪First modification≫
Next, a first modification of the first embodiment will be described.

The same parts as those in the above embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

FIG. 20 is a schematic configuration diagram of the wireless quality analyzer 100A of the first modification of the first embodiment.

The wireless quality monitoring system of this modification has a configuration in which the wireless quality analyzer 100 is replaced with the wireless quality analyzer 100A in the wireless quality monitoring system 1000 of the first embodiment.

As shown in FIG. 20, the wireless quality analyzer 100A has a configuration in which the analysis unit 14 is replaced with the analysis unit 14A in the wireless quality analyzer 100. Other than that, the wireless quality analyzer 100A is the same as the wireless quality analyzer 100.

The analysis unit 14A has a configuration in which a clock unit 147 and a time axis correction unit 148 are added to the analysis unit 14. Other than that, the analysis unit 14A is the same as the analysis unit 14.

In the wireless quality analyzer 100 of the first embodiment, the time of the time-series data of the header data acquired by all the sensor devices included in the wireless quality monitoring system 1000 so as to match the time axis of one sensor device. Correct the deviation. That is, the result data of the integrated processing (for example, the data shown in FIG. 18) acquired by the wireless quality analyzer 100 of the first embodiment, that is, the data in which the time information of each header information is expressed on the same time axis is the data. It is the data using the relative time axis.

In the wireless quality analyzer 100A of this modification, the result data of the integrated processing acquired by executing the same processing as in the first embodiment can be corrected so as to match the absolute time.

The clock unit 147 is a functional unit that manages time information, and is a functional unit that can acquire an absolute time.

The time axis correction unit 148 corrects the time axis of the result data of the integrated processing acquired by the correction time series data acquisition unit 145 so as to match the absolute time, based on the absolute time information acquired by the clock unit 147. Perform the processing. Specifically, the time axis correction unit 148 uses time information as a reference when the integrated process is executed by the correction time series data acquisition unit 145 (in the case of FIG. 18, each header information of the header data of the sensor device S_node1). (Time information defined by the time information of) (this is called "first reference time information") is corrected based on the absolute time information acquired by the clock unit 147, and the time information (the first reference time information) is used as the reference. 1 Adjust so that the reference time information) is the absolute time.

Then, the time axis correction unit 148 is header data of a sensor device other than the sensor device that has acquired the header data including the first reference time information, and is each header information of the header data matched with the first reference time information. The time information is corrected based on the first reference time information and the absolute time information acquired by the clock unit 147 so that the time information becomes the absolute time.

In the wireless quality analyzer 100A, the wireless communication environment analysis processing is appropriately performed by using the data (data after the integration processing) expressing the time information of each header information on the same time axis defined by the absolute time. It can be performed.

The clock unit 147 may be installed in a device (which may be a sensor device) other than the wireless quality analyzer 100A. In this case, the wireless quality analyzer 100A may acquire the absolute time information from the device by communication via the network.

[Other Embodiments]
In the above embodiment (including a modified example), the case where the wireless quality monitoring system has the configuration shown in FIG. 1 has been described as an example, but the configuration of the wireless quality monitoring system is not limited to the above (FIG. 1 and the like). , The position, number, etc. of the sensor devices may be other than the above. Further, in the above, the case where the sensor device exists separately from the communication device has been described, but the present invention is not limited to this, and for example, the communication device includes or is added to the sensor device. It may be.

Further, when the wireless quality analyzer and the sensor device of the above embodiment (including a modification) communicate wirelessly, the wireless quality analyzer and the sensor device communicate with each other by using the antenna of the sensor device. May be good.

Further, in the above embodiment (including the modified example), the case where there are two master / slave pairs has been described, but the present invention is not limited to this, and one master / slave pair may be used. It may be 3 or more. When there is only one master / slave pair, the header data with the same time axis can be acquired when the second correction process is completed. In this case, the integration process in step S8 can be omitted.

Further, in the wireless quality monitoring system described in the above embodiment (including a modification), each block may be individually integrated into one chip by a semiconductor device such as an LSI, or may be partially or completely included. It may be made into a chip.

Although it is referred to as an LSI here, it may be referred to as an IC, a system LSI, a super LSI, or an ultra LSI depending on the degree of integration.

Further, the method of making an integrated circuit is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure the connection and settings of the circuit cells inside the LSI may be used.

In addition, a part or all of the processing of each functional block of each of the above embodiments may be realized by a program. Then, a part or all of the processing of each functional block of each of the above embodiments is performed by the central processing unit (CPU) in the computer. Further, the program for performing each process is stored in a storage device such as a hard disk or a ROM, and is read and executed in the ROM or the RAM.

Further, each process of the above embodiment may be realized by hardware, or may be realized by software (including a case where it is realized together with an OS (operating system), middleware, or a predetermined library). Further, it may be realized by mixed processing of software and hardware.

Further, for example, when each functional unit of the above embodiment (including a modified example) is realized by software, the hardware configuration (for example, CPU, ROM, RAM, input unit, output unit, etc.) shown in FIG. 21 is busted. (Hardware configuration connected by Bus) may be used to realize each functional unit by software processing.

Further, the execution order of the processing methods in the above-described embodiment is not necessarily limited to the description of the above-described embodiment, and the execution order can be changed without departing from the gist of the invention.

A computer program that causes a computer to perform the above-mentioned method and a computer-readable recording medium that records the program are included in the scope of the present invention. Here, examples of computer-readable recording media include flexible disks, hard disks, CD-ROMs, MOs, DVDs, DVD-ROMs, DVD-RAMs, large-capacity DVDs, next-generation DVDs, and semiconductor memories. ..

The computer program is not limited to the one recorded on the recording medium, and may be transmitted via a telecommunication line, a wireless or wired communication line, a network typified by the Internet, or the like.

The specific configuration of the present invention is not limited to the above-described embodiment, and various changes and modifications can be made without departing from the gist of the invention.

1000 Wireless quality monitoring system 100, 100A Wireless quality analyzer 13 Header data collection unit 14, 14A Analysis unit 141 Master / slave selection unit 142 Data acquisition unit 143 First correction processing unit 144 Second correction processing unit 145 Correction time series data acquisition Unit 146 Analysis processing unit 147 Clock unit 148 Time axis correction unit

Claims (6)

A wireless quality analyzer used in a wireless quality monitoring system that includes multiple sensor devices.
It is a header data collecting unit that collects header data which is time series data including a plurality of header information acquired from frames received by each sensor device from the plurality of sensor devices, and the header information is at least the header information. The header data collection unit, which includes time information for specifying the transmission start time of the extracted frame,
A master-slave selection unit that selects one of the plurality of sensor devices as a master device and selects a sensor device other than the device selected as the master device among the plurality of sensor devices as a slave device.
The header data acquired by the sensor device selected as the master device by the master-slave selection unit is acquired as the master header data, and the header data acquired by the sensor device selected as the slave device by the master-slave selection unit is acquired. The data acquisition unit to be acquired as slave header data,
The header information included in the slave header data, which is the header information acquired from the same frame as the frame in which the master side header information which is the header information included in the master header data is acquired, is extracted and extracted as the slave side header information. By setting the time information of the slave side header information to the time information of the master side header information acquired from the same frame as the frame from which the slave side header information was acquired, the time information of the slave side header information is corrected. The first correction processing unit that executes the first correction processing
Regarding the slave side header information that was not the target of the first correction process, the transmission start time of the frame from which the slave side header information was acquired and the frame from which the slave side header information that was the target of the first correction process was acquired. The slave-side header information having the smallest time difference from the transmission start time of is selected from the slave-side header information that is the target of the first correction process, and the selected slave-side header information is used as the slave-side reference header information. The time information of the slave-side reference header information corrected by the first correction process, the time information of the slave-side reference header information, and the time information of the slave-side header information not subject to the first correction process. A second correction processing unit that executes a second correction process for correcting the time information of the slave side header information that was not the target of the first correction process based on the time difference of
Based on the master header data and the slave header data whose time information has been corrected by the first correction process and the second correction process, the time information of each header information is adjusted to be the time on the same time axis. A correction time series data acquisition unit that acquires the corrected header data as correction time series data,
Based on the corrected time series data, an analysis unit that analyzes the quality of the wireless environment in which the sensor device is installed, and an analysis unit.
A wireless quality analyzer equipped with. The correction time series data acquisition unit
When a plurality of pairs of the master header data and the slave header data whose time information has been corrected by the first correction process and the second correction process are acquired, the header information for the commonly observed frame is detected. Then, based on the detected time information of the header information, the time information of the header information included in each header data is corrected so that the time axis of each header data matches.
The wireless quality analyzer according to claim 1. The header information further includes a retransmission flag, a source MAC address, a destination MAC address, and a sequence number.
The first correction processing unit
In the slave side header information and the master side header information,
In both (1), the retransmission flag is "0", and (2) the source MAC address is the same, and
(3) The destination MAC address is the same, and (3) the sequence number is the same.
In this case, it is determined that the frame from which the slave side header information has been acquired and the frame from which the master side header information has been acquired are the same frame.
The wireless quality analyzer according to claim 1 or 2. A time axis that acquires information about the absolute time and corrects the time information of the header information included in the corrected time series data so that the time axis of the corrected time series data becomes the time axis defined by the absolute time. Further equipped with a correction unit,
The wireless quality analyzer according to any one of claims 1 to 3. A wireless quality analysis method used in wireless quality monitoring systems that include multiple sensor devices.
It is a header data collection step of collecting header data which is time series data including a plurality of header information acquired from frames received by each sensor device from the plurality of sensor devices, and the header information is at least the header information. The header data collection step, which includes time information for specifying the transmission start time of the extracted frame, and
A master-slave selection step of selecting one of the plurality of sensor devices as a master device and selecting a sensor device other than the device selected as the master device among the plurality of sensor devices as a slave device.
The header data acquired by the sensor device selected as the master device by the master-slave selection step is acquired as the master header data, and the header data acquired by the sensor device selected as the slave device by the master-slave selection step is acquired. Data acquisition step to acquire as slave header data,
The header information included in the slave header data, which is the header information acquired from the same frame as the frame in which the master side header information which is the header information included in the master header data is acquired, is extracted and extracted as the slave side header information. By setting the time information of the slave side header information to the time information of the master side header information acquired from the same frame as the frame from which the slave side header information was acquired, the time information of the slave side header information is corrected. The first correction processing step for executing the first correction processing to be performed, and
Regarding the slave side header information that was not the target of the first correction process, the transmission start time of the frame from which the slave side header information was acquired and the frame from which the slave side header information that was the target of the first correction process was acquired. The slave-side header information having the smallest time difference from the transmission start time of is selected from the slave-side header information that is the target of the first correction process, and the selected slave-side header information is used as the slave-side reference header information. The time information of the slave-side reference header information corrected by the first correction process, the time information of the slave-side reference header information, and the time information of the slave-side header information not subject to the first correction process. The second correction processing step of executing the second correction processing for correcting the time information of the slave side header information that was not the target of the first correction processing based on the time difference of
Based on the master header data and the slave header data whose time information has been corrected by the first correction process and the second correction process, the time information of each header information is adjusted to be the time on the same time axis. The correction time series data acquisition step to acquire the corrected header data as correction time series data,
Based on the corrected time series data, an analysis step for performing analysis processing on the quality of the wireless environment in which the sensor device is installed, and
A wireless quality analysis method that includes. A program for causing a computer to execute the wireless quality analysis method according to claim 5.

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