WO2022030329A1

WO2022030329A1 - Wireless communication device, wireless communication scheme, and wireless communication program

Info

Publication number: WO2022030329A1
Application number: PCT/JP2021/027908
Authority: WO
Inventors: 徹大須賀; 聡子板谷; 史秀児島
Original assignee: 国立研究開発法人情報通信研究機構
Priority date: 2020-08-07
Filing date: 2021-07-28
Publication date: 2022-02-10
Also published as: JP2022030951A

Abstract

[Problem] To provide a wireless communication device capable of strategically and efficiently satisfying good QoS requirements under a wireless environment in which a communication failure factor is generated. [Solution] An embodiment relates to a wireless communication device comprising: an error correction unit 12 which, with respect to an error that can be corrected, performs a transmission data encoding process during data transmission, and performs a reception data decoding process during data reception; a noise estimating unit 13 which, on the basis of at least one of the success/failure of data communication via a wireless network, including whether the error has been corrected, and the result of measurement of a radiowave environment of the wireless network, estimates a noise generation pattern including the timing of generation of a communication failure factor including a periodically generated noise, and a continuation time of the communication failure factor; and a transmission waiting time setting unit 14 which, on the basis of the noise generation pattern, sets a transmission waiting time for allowing transmission of the transmission data to wait.

Description

Wireless communication equipment, wireless communication method and wireless communication program

An embodiment of the present invention relates to a wireless communication device, a wireless communication method, and a wireless communication program.

For example, at the manufacturing site, productivity is being improved by attaching sensors to tools and collecting information, and by operating AGVs (Automated Guided Vehicles) to transport parts. Since these tools, AGVs, etc. move according to the movement of people and objects, wireless communication is required for real-time information collection and operation.

In addition, at the manufacturing site, noise is generated due to the operation of machines, etc., which has an adverse effect such as causing an error in the data being communicated, and cannot meet the QoS (Quality of Service) requirements for wireless communication such as communication delay. There is a situation.

The technology described in Patent Document 1, Patent Document 2 and Non-Patent Document 1 is provided for such a situation that the QoS requirement of wireless communication cannot be satisfied.

In Patent Document 1, in an environment where a plurality of wireless communications coexist, a technique for scheduling so that a plurality of flows do not interfere with each other by monopolizing wireless resources according to the traffic volume of each flow and allocating a good time is used. It has been disclosed.

In Non-Patent Document 1, it is confirmed whether other communication is performed before communication, and if a radio wave having a signal strength of a certain level or higher is flying, the communication is waited for for other communication or noise. Specifications that avoid the impact are disclosed.

In Patent Document 2, radio waves whose received signal strength exceeds a threshold value are determined to be noise, noise generation time and non-generation time are measured, and noise is generated under the assumption that this is repeated periodically. A technique for setting a communication rate so that a communication delay can be satisfied by communication while there is no noise is disclosed.

Japanese Unexamined Patent Publication No. 2019-118050 Japanese Unexamined Patent Publication No. 2018-019307

Here, communication and noise at the manufacturing site have the following characteristics.
(1) Communication and noise generation basically do not have perfect periodicity. However, at the manufacturing site, a plurality of production processes are linked with each other using the takt time as a cycle. Therefore, it is possible to expect a certain degree of periodicity in communication and noise generation.
(2) At the manufacturing site, noise that has a slight effect on wireless communication (inverter noise, etc.) and heavy noise (wireless power supply, etc.) are mixed.

The technique disclosed in Patent Document 1 can be scheduled so as not to interfere with each other for a plurality of controllable flows. However, unlike communication, noise cannot be scheduled and has an adverse effect because its generation cannot be controlled. Therefore, there is a situation that the QoS requirement cannot be satisfied in an environment where noise is generated.

Further, the specifications disclosed in Non-Patent Document 1 can avoid interference when noise occurs. However, it is a sequential control that does not communicate if other communication or noise is flying when trying to communicate. Therefore, there is a situation that the QoS requirements cannot be met systematically.

Further, as shown in FIG. 7A, the technique disclosed in Patent Document 2 sets the transmission standby time W at equal intervals and the same duration with respect to the noise N generated only at equal intervals and the same duration. By setting to, it is possible to avoid noise N and communicate so as to satisfy the communication delay, for example. Then, the period between the transmission standby time W is defined as the communicable communication slot time T. However, as described above, although the noise at the manufacturing site has a certain degree of periodicity, the timing at which the noise is generated and the duration at which the noise continues are various. Therefore, as shown in FIG. 7B, there is a situation that the interference periods I0 to I2 in which the noises N100 and N200 overlap occur in the communication slot time T, and the QoS deteriorates. There is also a mild noise N300 that does not affect communication. Even if a slight noise N300 is generated, the communication is stopped, and the communication time is wasted, which hinders the improvement of the communication efficiency.

An embodiment of the present invention provides a wireless communication device, a wireless communication method, and a wireless communication program capable of systematically and efficiently satisfying good QoS requirements even in a wireless environment in which a communication failure element occurs.

The wireless communication device according to the first aspect of the present invention is a wireless communication device that performs data communication via a wireless network, and is a transmission device that transmits transmission data via the wireless network and a reception device that receives reception data. In data transmission, the transmission data is encoded so that the error can be corrected without retransmitting the data for a correctable error including a bit error generated in the data being communicated with the transmission / reception unit having the above. In the data reception, the error correction unit that performs the decryption process of the received data, the success or failure of the data communication via the wireless network including whether or not the error can be corrected by the error correction unit, and the wireless network. A noise estimation unit that estimates a noise generation pattern including the generation timing of a communication failure element including periodically generated noise and the duration of the communication failure element based on at least one of the results of measuring the radio wave environment of. And, based on the noise generation pattern, the time during which the transmitted data does not reach the receiving device normally even if the data is transmitted to the wireless network is set, and the time during which the transmitted data does not reach normally is set. The transmission device of the transmission / reception unit is provided with a transmission standby time setting unit for setting a transmission standby time for waiting for transmission of the transmission data to the wireless network.

In the first aspect of the wireless communication device according to the second aspect of the present invention, the noise estimation unit is (a) the number or ratio of the transmitted data that did not normally reach the receiving device (b). Number or percentage of received data that the transmission / reception unit could not receive normally (c) The signal strength observed in the measurement of the radio wave environment was equal to or higher than a predetermined threshold, and the transmission / reception unit was used for data. Number of times or ratio excluding the case where It is detected that the communication failure element has occurred when at least one value of the time or ratio excluding the case is equal to or higher than a predetermined threshold value, and the communication failure element has occurred or the value of the communication failure element. Is stored as time-series information together with the time when the communication failure element occurs, and based on the time-series information, the occurrence of the communication failure element is modeled and the noise generation pattern is estimated.

In the second aspect of the wireless communication device according to the third aspect of the present invention, the noise estimation unit further divides a predetermined time interval as a cycle, and the same noise generation pattern is repeated for each cycle. Is a precondition, and the noise generation pattern is estimated by modeling the occurrence of a communication failure element based on the time series information.

In the wireless communication device according to the fourth aspect of the present invention, in any one of the first to third aspects, the noise estimation unit (e) normally reaches the receiving side device among the transmitted data. Number or percentage of the received data (f) Number or percentage of the received data that the transmission / reception unit could not receive normally (g) The signal strength observed in the measurement of the radio wave environment is equal to or higher than a predetermined threshold value. Among them, the number of times or ratio excluding the case where the transmission / reception unit was transmitting / receiving data (h) The channel usage time observed in the measurement of the radio wave environment was equal to or more than a predetermined threshold value. It is detected that the communication failure element has occurred when at least one value of the time or ratio excluding the case where the transmission / reception unit is transmitting / receiving data is equal to or higher than a predetermined threshold value, and the predetermined time interval is set. First, it is presumed that the communication failure element does not occur in the noise generation pattern in a certain cycle in the divided cycle with respect to the divided cycle. The time zone and the second time zone in which the communication failure element is presumed to have occurred are stored, and these are recorded in a continuous cycle other than the certain cycle, which is a predetermined number of times or more, in the divided cycle. The first time zone and the second time zone are stored, and in the noise generation pattern in the continuous cycle, among the time zones stored in the first time zone, the noise generation pattern in the certain cycle When the second time zone is stored, the noise generation pattern is updated so that the time zone is included in the second time zone, and the noise generation pattern in the continuous cycle is the second time zone. Of the time zones stored as, when the noise generation pattern in the certain cycle is stored as the first time zone, the time zone is predetermined to be gradually included in the first time zone. It is characterized in that the noise generation pattern is updated so as to change the second time zone to the first time zone at a time or rate.

In the fourth aspect of the wireless communication device according to the fifth aspect of the present invention, the noise estimation unit has a constant timing in the second time zone in which the communication failure element is estimated to have occurred in the noise generation pattern. It is also characterized by further providing a mechanism for controlling so as to converge to a certain duration.

In the wireless communication device according to the sixth aspect of the present invention, it is estimated that the communication failure element has occurred in the noise generation pattern estimated by the noise estimation unit in any one of the first to fifth aspects. For the time zone, (i) information on the intensity or frequency of the noise in the estimated time zone (j) the time width of the estimated time zone (k) in the vicinity of the estimated time zone. Based on at least one of the information related to wireless communication including the communication throughput and the data rate in the same time zone of the time zone or other cycle, the transmission standby time setting unit sets the estimated time zone to the transmission standby time. It is characterized in that the error correction unit is further provided with a noise handling method determination unit for determining whether to increase the coding rate of the error correction.

The wireless communication method according to the seventh aspect of the present invention is a wireless communication method for performing data communication via a wireless network, and retransmits data in response to a correctable error including a bit error generated in the data being communicated. In the data transmission, the transmission data is encoded, and in the data reception, the received data is decoded, and the radio including whether or not the error can be corrected is performed so that the error can be corrected without the above. Based on at least one of the results of measuring the success or failure of data communication via the network and the radio environment of the wireless network, the timing of occurrence of a communication failure element including periodic noise and the duration of the communication failure element. The noise generation pattern including the above is estimated, and based on the noise generation pattern, the time during which the transmission data does not reach the receiving device normally even if the data is transmitted to the wireless network is set, and the transmission data is normal. It is characterized in that the transmission of the transmission data to the wireless network is made to wait during the time when the data is not reached.

The wireless communication program according to the eighth aspect of the present invention is a wireless communication method for performing data communication via a wireless network, and retransmits data in response to a correctable error including a bit error generated in the data being communicated. In order to be able to correct the error without doing so, the procedure of encoding the transmitted data in the data transmission and decoding the received data in the data reception, and whether or not the error can be corrected are included. Based on at least one of the results of measuring the success or failure of data communication via the wireless network and the radio environment of the wireless network, the timing of occurrence of a communication failure element including periodic noise and the continuation of the communication failure element. A procedure for estimating a noise generation pattern including time and a time during which the transmitted data does not normally reach the receiving device even if data is transmitted to the wireless network are set based on the noise generation pattern. It is characterized by comprising a procedure of waiting for transmission of the transmission data to the wireless network during a time when the transmission data does not reach normally.

According to the first to eighth aspects of the present invention, a wireless communication device, a wireless communication method, and a wireless system capable of systematically and efficiently satisfying good QoS requirements even in a wireless environment in which a communication failure element occurs. Can provide communication programs.

FIG. 1 is a schematic block diagram showing an example of a basic configuration of a wireless communication system capable of executing the wireless communication method according to the first embodiment. FIG. 2 is a schematic diagram showing an example of an image of a manufacturing site to which the wireless communication system according to the first embodiment is applied. FIG. 3 is a flowchart showing an example of the wireless communication method according to the first embodiment. FIG. 4 is a time chart showing an example of data communication by the wireless communication method according to the first embodiment. 5 (a) to 5 (c) are time charts showing other examples of data communication by the wireless communication method according to the first embodiment. It is a schematic block diagram which shows an example of the basic structure of the wireless communication system which can execute the wireless communication method which concerns on 2nd Embodiment. 7 (a) and 7 (b) are time charts showing the problems to be solved by the invention.

Hereinafter, some embodiments of the present invention will be described with reference to the drawings. In each figure, common reference numerals are given to common parts, and duplicate explanations are omitted.

(First Embodiment)
FIG. 1 is a schematic block diagram showing an example of a basic configuration of a wireless communication system capable of executing the wireless communication method (wireless communication method) according to the first embodiment. FIG. 2 is a schematic diagram showing an example of an image of a manufacturing site to which the wireless communication system according to the first embodiment is applied.

<Wireless communication system 100>
As shown in FIG. 1, the wireless communication system 100 capable of executing the wireless communication method according to the first embodiment includes a plurality of wireless communication devices that perform data communication via the wireless network 3. FIG. 1 shows one first wireless communication device 1 and one second wireless communication device 2 as a basic example. A plurality of first wireless communication devices 1 may exist, and a plurality of second wireless communication devices 2 may exist.

The first wireless communication device 1 is incorporated in the transmitting side device 51 as hardware, for example. In the example of the transmitting side device 51, when the environment to which the wireless communication system 100 is applied is a manufacturing site, as shown in FIG. 2, a production tool (manufacturing tool, manufacturing device, etc.) 51a, a robot 51b, and an automatic guided vehicle (manufacturing tool 51) are used. AGV: Automatic Guided Vehicle) 51c, inspection device 51d, surveillance camera (imaging device) 51e, and the like.

The second wireless communication device 2 is incorporated in the receiving side device 52 as hardware, for example. As shown in FIG. 2, an example of the receiving side device 52 is an access point (AP) device 52a or the like at a manufacturing site.

When the transmitting side device 51 has a wireless communication device (existing wireless communication device), the first wireless communication device 1 transmits the wireless communication flow executed by the first wireless communication device 1 as software (wireless communication computer program). It can also be incorporated into the side device 51. The same applies to the second wireless communication device 2. In these cases, the existing wireless communication device operates as a wireless communication device similar to the first wireless communication device 1 or the second wireless communication device 2.

As described above, the first embodiment of the invention can be implemented by both hardware and software, but the embodiment will be described assuming that it is mainly implemented as hardware.

<1st wireless communication device 1>
As shown in FIG. 1, the first wireless communication device 1 includes a first transmission / reception unit 11, a first error correction unit 12, a noise estimation unit 13, a transmission standby time setting unit 14, and a first communication control unit 15.

The first transmission / reception unit 11 wirelessly transmits / receives data.

In the case of data transmission, for example, the first error correction unit 12 can correct the error without retransmitting the data for a correctable error such as a bit error generated in the data being communicated. The transmission device of the first transmission / reception unit 11 performs the transmission data coding process, and in the case of data reception, for example, the reception device of the first transmission / reception unit 11 performs the reception data decoding process.

The noise estimation unit 13 is used for at least one of the communication result of data communication via the wireless network 3 including whether or not the error can be corrected by the first error correction unit 12 and the result of measuring the radio wave environment of the wireless network 3. Based on this, the noise generation pattern is estimated. The noise generation pattern includes, for example, the occurrence timing of the communication failure element that occurs periodically and the duration of the communication failure element. An example of a communication failure element is noise, and the communication failure element includes at least noise. In the present specification, the "communication failure element" is abbreviated as noise or the like as necessary. Here, when the noise estimation unit 13 can correct a bit error or the like by the first error correction unit 12, the data has normally arrived at the transmitting side device 51 or the transmitting side device 51 has normally received the data as received data. It is judged that it has been completed, and it is excluded from the detection of noise and the like.

The noise estimation unit 13 according to this embodiment is, for example,
(A) Number or ratio of transmitted data that did not reach the receiving device 52 normally (b) Number or ratio of received data that the first transmission / reception unit 11 could not normally receive (c) Of the radio wave environment The number or ratio of the signal strength observed in the measurement excluding the case where the first transmission / reception unit 11 was transmitting / receiving data while the signal strength was equal to or higher than the predetermined threshold value (d) Observed in the measurement of the radio wave environment. While the channel usage time was at least a predetermined threshold, at least one value of the time or ratio excluding the case where the first transmission / reception unit 11 was transmitting / receiving data was at least a predetermined threshold. In some cases, it is detected that a communication failure element has occurred. Further, the noise estimation unit 13 stores the occurrence of the communication failure element or the value of the communication failure element as time-series information together with the time when the communication failure element occurs, and based on this time-series information, the communication failure element of the communication failure element. Model the occurrence and estimate the noise generation pattern.

Further, the noise estimation unit 13 according to this embodiment is based on the precondition that, for example, a predetermined time interval is divided as a cycle and the same noise generation pattern is repeated for each of these divided cycles, and the time series information is described above. It is also possible to model the occurrence of a communication failure element and estimate the noise generation pattern based on the above. When modeling, for example,
-Estimate the noise generated in the same time zone for each cycle as a noise generation pattern-The noise generation pattern is created by statistically superimposing the time-series information of the noise etc. generated in each cycle or the value of the noise etc. At least one of the estimates may be used.

The transmission standby time setting unit 14 is based on the noise generation pattern estimated by the noise estimation unit 13, and the time during which the transmission data does not normally reach the reception device of the reception side device 52 due to the influence of noise or the like (transmission standby time). ) Is set. Then, the transmission standby time setting unit 14 causes the data transmission / reception unit of the transmission side device 51 to wait for data transmission to the wireless network during the transmission standby time.

The first communication control unit 15 controls the transmission / reception of data in the first transmission / reception unit 11. At the time of data transmission, the first communication control unit 15 causes the data transmission from the first wireless communication device 1 to the second wireless communication device 2 to stand by during the transmission standby time. Then, data transmission from the first wireless communication device 1 to the second wireless communication device 2 is executed during the communication slot time during which data transmission is possible, which is set in addition to the transmission standby time.

<Second wireless communication device 2>
As shown in FIG. 1, the second wireless communication device 2 includes a second transmission / reception unit 21, a second error correction unit 22, and a second communication control unit 25.

The second transmission / reception unit 21 wirelessly transmits / receives data.

Similar to the first error correction unit 12, the second error correction unit 22 performs an encoding process in the case of data transmission and a decoding process in the case of data reception so that the bit error or the like can be corrected. conduct.

The second communication control unit 25 controls the transmission / reception of data in the second transmission / reception unit 21.

<Wireless communication flow (wireless communication method)>
FIG. 3 is a flowchart showing an example of the wireless communication method according to the first embodiment. FIG. 4 is a time chart showing an example of data communication by the wireless communication method according to the first embodiment.

<< Estimating the occurrence pattern of communication failure elements >>
First, as shown in step ST1 in FIG. 3, the generation pattern of communication failure elements such as noise periodically generated in the wireless network 3 is estimated. The generation pattern of the communication failure element such as noise is based on at least one of the communication result of data communication via the wireless network 3 and the measurement result of measuring the radio wave environment of the wireless network 3. These communication results and / or measurement results can be obtained, for example, by actually transmitting and receiving data by the first transmission / reception unit 11.

Here, the communication failure element includes, for example, an element that occurs in conjunction with the tact time set in the wireless usage environment. An example of a wireless usage environment is, for example, a manufacturing site shown in FIG. For example, at a manufacturing site, each of a plurality of production processes is linked with a takt time as a cycle. Therefore, it is possible to expect a certain degree of periodicity in the generation of noise and the like. In the wireless communication method according to the first embodiment, for example, attention is paid to a communication failure element that occurs in conjunction with the takt time, and it is searched for whether or not the occurrence timing and duration of this communication failure element have periodicity. do. The noise estimation unit 13 estimates a pattern (noise generation pattern) such as the timing at which the communication failure element occurs and the duration during which the communication failure element continues.

<< Exclusion of minor communication failure elements >>
Next, as shown in step ST2 in FIG. 3, among the communication failure elements, the mild ones are excluded from the noise generation pattern. In the first embodiment, the minor communication failure element means, for example, an element that can be recovered by error correction in the first error correction unit 12 and the second error correction unit 22, an element that does not affect communication, and the like. Inverter noise and the like can be mentioned as an example of a minor communication failure element. In this way, a minor communication failure element is excluded from the noise generation pattern, and transmission is made to stand by when a severe communication failure element occurs. This makes it possible to eliminate waste of wireless resources and improve communication efficiency.

<< Setting the transmission standby time >>
Next, as shown in step ST3 in FIG. 3, the transmission standby times W0 to W1 for waiting for data transmission are set based on the estimated noise generation pattern. The transmission standby times W0 to W1 are not set at equal intervals, but are flexibly set according to the generation timing of noises N0 to N2 and the like and the duration of noise and the like, as shown in FIG. As a result, it is possible to reduce the occurrence of communication interference due to noises N0 to N2 and the like, as compared with the case where the transmission standby times W0 to W1 are set at equal intervals. This makes it possible to systematically and efficiently satisfy good QoS requirements even in a wireless environment where communication failure elements occur. The transmission standby time is set in the transmission standby time setting unit 14.

<< Communication slot time setting >>
Next, as shown in step ST4 in FIG. 3, the communication slot times T0 to T2 at which data can be transmitted are set at the time excluding the transmission standby time W0 to W1. The communication slot times T0 to T2 are sequentially set to, for example, the transmission standby time W0 to W1 after the transmission standby time W0 to W1. The communication slot times T0 to T2 can also be set, for example, by detecting that the transmission standby time W0 to W1 has ended and that the transmission standby time W0 to W1 has started, respectively.

<< Sending data >>
In steps ST1 to ST4 up to this point, transmission standby times W0 to W1 and communication slot times T0 to T2 are set in the transmission side device 51, respectively. After that, as shown in step ST5 in FIG. 3, data transmission may be executed according to the set transmission standby time W0 to W1 and the communication slot time T0 to T2. The transmission data TD is transmitted from the transmission side device 51 to the first transmission / reception unit 11 via, for example, the first error correction unit 12, and is transmitted from the first transmission / reception unit 11 to the wireless network 3. The second transmission / reception unit 21 receives the transmission data TD as the reception data RD. Such data communication is repeated until the required communication is completed.

According to such a first embodiment, for example,
(1) In a wireless environment where a communication failure element occurs, when it is possible to expect a certain degree of periodicity in the occurrence of the communication failure element, the timing at which the communication failure element occurs, the duration of the communication failure element, etc. Estimate the pattern of. The transmission waiting time is flexibly set according to this estimated pattern. Therefore, even in a wireless environment where a communication failure element occurs, good QoS requirements can be satisfied systematically and efficiently.
(2) Minor communication failure elements are excluded, and when a severe communication failure element occurs, transmission is made to stand by. That is, when a minor communication failure element occurs, communication is continued. Therefore, waste of wireless resources can be eliminated, and communication efficiency can be improved.
You can get the advantage.

<Other examples of data communication>
5 (a) to 5 (c) are time charts showing other examples of data communication by the wireless communication method according to the first embodiment.
As described above, the noise estimation unit 13 according to this embodiment is
(E) Number or ratio of transmitted data that did not reach the receiving device 52 normally (f) Number or ratio of received data that the first transmission / reception unit 11 could not normally receive (g) Of the radio wave environment The number or ratio of the signal strength observed in the measurement excluding the case where the first transmission / reception unit 11 was transmitting / receiving data while the signal strength was equal to or higher than the predetermined threshold value (h) Observed in the measurement of the radio wave environment. While the channel usage time was at least a predetermined threshold, at least one value of the time or ratio excluding the case where the first transmission / reception unit 11 was transmitting / receiving data was at least a predetermined threshold. In some cases, it is detected that a communication failure element has occurred.

The noise estimation unit 13 according to this embodiment divides a predetermined time interval, for example, a tact time 0 to a tact time 4 ... as a cycle. As shown in FIG. 5A, the noise estimation unit 13 generates a communication failure element in a certain cycle, for example, in the tact time 2, in the noise generation pattern in the tact time 2, with respect to these divided cycles. The time zone estimated not to be present (first time zone: communication slot time T) and the time zone estimated to have generated the communication failure element (second time zone: transmission standby time W) are stored. Similarly, a communication failure element also occurs in a noise generation pattern in a cycle other than the tact time 2 that is continuous for a predetermined number of times or more, for example, a tact time 0, a tact time 1, a tact time 3, a tact time 4, and so on. The time zone estimated not to exist (first time zone: communication slot time T) and the time zone estimated to have generated the communication failure element (second time zone: transmission standby time W) are stored.

Next, as shown in FIG. 5 (b), among tact time 0 to tact time 4 ..., tact time 0 and tact that are continuous for a predetermined number of times (the number of times in this example is assumed to be "2") and tact. In the noise generation patterns at time 1, takt time 3 and takt time 4, it is estimated that no communication failure element has occurred, and the first time zone (T) and the stored time zone are in a certain cycle. When the noise generation pattern is stored as the second time zone (W), the noise generation pattern is updated so that the time zone is included in the second time zone (W). In this way, the transmission standby time Wa is added to the above time zones (communication slot time T) of the tact time 0 and the tact time 1, and the tact time 3 and the tact time 4.

Further, as shown in FIG. 5 (c), in the noise generation pattern in the tact time 2, it is estimated that a communication failure has occurred, and the tact time is the second time zone and the stored time zone (W). It is estimated that a communication failure element has occurred in the noise generation patterns at 0 and tact time 1, and tact time 3 and tact time 4, and when stored as the first time zone, the time zone is the first time zone (T). ) Is gradually included, and the noise generation pattern is updated so as to change the second time zone (W) to the first time zone (T) at a predetermined time or ratio. In the example shown in FIG. 5 (c), the time zone is. An example of reduction at a predetermined time or rate is shown. As shown in FIG. 5C, the transmission standby time Wa in the tact time 0 and the tact time 1, and the tact time 3 and the tact time 4 is set in accordance with the update of the second time zone (W) in the tact time 2. You may update it.

The noise estimation unit 13 can also set the transmission standby time, for example, as shown in FIGS. 5A to 5C. In such a noise estimation unit 13, in the noise generation pattern, the time zone W (second time zone and third time zone) in which the communication failure element is estimated to have occurred converges to a certain timing and a certain duration. It is also possible to further provide a mechanism for controlling the noise. For this mechanism, for example, consideration of hysteresis in noise and the like, and classical control methods such as PID control can be used.

<Modification example of wireless communication device>
Further, the first wireless communication device 1 may further include, for example, a noise handling method determination unit.

The noise handling method determination unit determines the time zone in which the communication failure element is estimated to have occurred in the noise generation pattern estimated by the noise estimation unit 13.
(I) Information on the intensity or frequency of noise in the estimated time zone (j) Time width of the estimated time zone (k) In a time zone near the estimated time zone or in the same time zone of another cycle Based on at least one of the information related to wireless communication including the communication throughput and the data rate, the transmission standby time setting unit 14 sets the estimated time zone as the transmission standby time, or the error correction unit 12 corrects the error. Decide whether to increase the coding rate.

(Second Embodiment)
FIG. 6 is a schematic block diagram showing an example of a basic configuration of a wireless communication system capable of executing the wireless communication method (wireless communication method) according to the second embodiment.

Depending on the wireless usage environment, a severe communication failure element may suddenly occur in the wireless network 3. The second embodiment relates to a wireless communication method, a wireless communication system, and a wireless communication program capable of maintaining good QoS even when a severe communication failure element suddenly occurs.

As shown in FIG. 6, the difference between the wireless communication system 100b and the wireless communication system 100 is that the wireless communication system 100 further includes a severe noise detection unit 71.

The severe noise detection unit 71 detects a sudden severe communication failure element that suddenly occurs in the wireless network 3. The severe noise detection unit 71 waits for data transmission from the first wireless communication device 1 to the second wireless communication device 2 (omitted in FIG. 6) while the severe communication failure element is occurring.

According to the wireless communication system 100b, since it further has a severe noise detection unit 71, when a severe communication failure element suddenly occurs, the data transmission is forcibly put on standby. Therefore, good QoS can be maintained even when a severe communication failure element suddenly occurs.

As shown in FIG. 6, the severe noise detection unit 71 may be in the transmitting side device 51 or in the receiving side device 52. Further, it may be in each of the transmitting side device 51 and the receiving side device 52. Further, in addition to the transmitting side device 51 and the receiving side device 52, the wireless communication system 100b may be separately provided as a severe noise detecting device.

As a method of determining whether or not the severe noise detection unit 71 has detected severe noise,
(L) Detect that a frame transmission error has occurred.
(M) Detects that a bit error or the like has occurred in the received frame.
(N) Provide a sensor for detecting severe noise.

In the case of (l), the severe noise detection unit 71 can be provided in, for example, the transmitting side device 51.
In the case of (m), the severe noise detection unit 71 can be provided in, for example, the receiving side device 52.
In the case of (n), the severe noise detection unit 71 can be provided in the transmitting side device 51 and / or the receiving side device 52. Alternatively, the wireless communication system 100b can be provided separately from the transmitting side device 51 and the receiving side device 52.

According to such a second embodiment, in addition to the advantages obtained from the first embodiment, good QoS is maintained even when a severe communication failure element suddenly occurs in the wireless network 3, for example. be able to.

Further, the embodiments of the present invention can be variously omitted, replaced, or changed without departing from the gist of the present invention. For example, the transmission standby time setting unit 14 for setting the transmission standby time does not necessarily have to be provided in the transmission side device 51. The transmission standby time setting unit 14 can also be provided in the receiving side device 52. When the transmission standby time setting unit 14 is provided in the receiving side device 52, for example, a CTS (Clear To Send) or the like may be used to allow the transmitting side device 51 to transmit. Further, the transmission standby time setting unit 14 can be provided in an external device such as a communication control server. For example, such novel forms and modifications are included in the scope and gist of the present invention, as well as in the scope of the invention described in the claims and the equivalent of the invention described in the claims. Will be.

100: Wireless communication system 100b: Wireless communication system 1: First wireless communication device 11: First transmission / reception unit 12: First error correction unit 13: Noise estimation unit 14: Transmission standby time setting unit 15: First communication control unit 2 : 2nd wireless communication device 21: 2nd transmission / reception unit 22: 2nd error correction unit
3: Wireless network 51: Transmitter device 51a: Production tool 51b: Robot 51c: Automated guided vehicle 51d: Inspection device 51e: Surveillance camera 52: Receiver device 52a: Access point (AP) device 71: Severe noise detector N: Noise N100: Noise N200: Noise N300: Noise N0 to N2: Noise W: Transmission standby time W0 to W1: Transmission standby time Wa: Transmission standby time T: Communication slot time T0 to T2: Communication slot time I0 to I2: Interference period TD: Transmission data RD: Received data

Claims

A wireless communication device that performs data communication via a wireless network.
A transmission / reception unit having a transmission device for transmitting transmission data and a reception device for receiving reception data via the wireless network, and a transmission / reception unit.
For correctable errors including bit errors that occur in the data being communicated, the transmitted data is encoded in the data transmission so that the error can be corrected without retransmitting the data, and in the data reception. Is an error correction unit that decodes the received data, and
Noise generated periodically based on at least one of the results of measuring the success or failure of data communication via the wireless network including whether or not the error was corrected by the error correction unit and the radio wave environment of the wireless network. A noise estimation unit that estimates a noise generation pattern including the occurrence timing of the communication failure element including the above and the duration of the communication failure element, and
Based on the noise generation pattern, the time during which the transmission data does not reach the receiving device normally even if the data is transmitted to the wireless network is set, and the transmission / reception is performed during the time during which the transmission data does not reach normally. A transmission standby time setting unit for setting a transmission standby time for causing the transmission device of the unit to wait for transmission of the transmission data to the wireless network, and a transmission standby time setting unit.
A wireless communication device characterized by being equipped with.
The noise estimation unit is
(A) The number or ratio of the transmitted data that did not reach the receiving device normally (b) The number or ratio of the received data that the transmitting / receiving unit could not normally receive (c) The radio wave environment The number or ratio of the signal strength observed in the measurement of (d) excluding the case where the transmission / reception unit was transmitting / receiving data while the signal strength was equal to or higher than the predetermined threshold value (d) Observed in the measurement of the radio wave environment. When at least one value of the time or ratio excluding the case where the transmission / reception unit is transmitting / receiving data is equal to or more than the predetermined threshold while the channel usage time is equal to or more than the predetermined threshold. Detecting that the communication failure element has occurred,
The occurrence of the communication failure element or the value of the communication failure element is stored as time-series information together with the time when the communication failure element occurs.
The wireless communication device according to claim 1, wherein the noise generation pattern is estimated by modeling the occurrence of the communication failure element based on the time-series information.
The noise estimation unit further
The noise generation pattern is modeled based on the time-series information on the precondition that the same noise generation pattern is repeated for each cycle by dividing a predetermined time interval as a cycle. 2. The wireless communication device according to claim 2, wherein the noise is estimated.
The noise estimation unit is
(E) The number or ratio of the transmitted data that did not reach the receiving device normally (f) The number or ratio of the received data that the transmitting / receiving unit could not normally receive (g) The radio wave environment The number or ratio of the signal strength observed in the measurement of (h) excluding the case where the transmission / reception unit was transmitting / receiving data while the signal strength was equal to or higher than the predetermined threshold value (h) was observed in the measurement of the radio wave environment. When at least one value of the time or ratio excluding the case where the transmission / reception unit is transmitting / receiving data is equal to or more than the predetermined threshold while the channel usage time is equal to or more than the predetermined threshold. Detecting that the communication failure element has occurred,
A predetermined time interval is divided as a cycle, and for the divided cycle,
It is estimated that the communication failure element occurred in the first time zone in which the communication failure element was estimated not to occur in the noise generation pattern in the certain cycle in the divided cycle. Remember the second time zone,
The first time zone and the second time zone are stored in a continuous cycle of a predetermined number of times or more other than the certain cycle in the divided cycle.
Of the time zones stored as the first time zone in the noise generation pattern in the continuous cycle, when the noise generation pattern in the certain cycle is stored as the second time zone, the time zone is the said. The noise generation pattern is updated so as to be included in the second time zone.
Of the time zones stored as the second time zone in the noise generation pattern in the continuous cycle, when the noise generation pattern in the certain cycle is stored as the first time zone, the time zone is the said. A claim characterized in that the noise generation pattern is updated so as to change the second time zone to the first time zone at a predetermined time or rate so as to be gradually included in the first time zone. Item 6. The wireless communication device according to any one of Items 1 to 3.
The noise estimation unit is
The claim is characterized in that, in the noise generation pattern, a mechanism for controlling the second time zone in which the communication failure element is presumed to have occurred so as to converge to a certain timing and a certain duration is further provided. 4. The wireless communication device according to 4.
In the noise generation pattern estimated by the noise estimation unit, with respect to the time zone estimated that the communication failure element occurred.
(I) Information on the intensity or frequency of the noise in the estimated time zone (j) Time width of the estimated time zone (k) Time zone in the vicinity of the estimated time zone or another cycle Based on at least one piece of information related to wireless communication, including communication throughput and data rate in the same time zone.
Further, the transmission standby time setting unit is provided with a noise handling method determination unit for determining whether to set the estimated time zone to the transmission standby time or to increase the error correction coding rate in the error correction unit. The wireless communication device according to any one of claims 1 to 5, wherein the wireless communication device is provided.
It is a wireless communication method that performs data communication via a wireless network.
For correctable errors including bit errors that occur in the data being communicated, the transmitted data is encoded in the data transmission so that the error can be corrected without retransmitting the data, and in the data reception. Decrypts the received data and performs
A communication failure element including periodic noise based on at least one of the results of measuring the success or failure of data communication via the wireless network including whether or not the error can be corrected and the radio wave environment of the wireless network. The noise generation pattern including the occurrence timing of the above and the duration of the communication failure element is estimated.
Based on the noise generation pattern, the time during which the transmitted data does not normally reach the receiving device even if the data is transmitted to the wireless network is set, and the wireless during the time during which the transmitted data does not reach normally. A wireless communication method characterized by waiting for transmission of the transmission data to a network.
A wireless communication program that communicates data via a wireless network.
For correctable errors including bit errors that occur in the data being communicated, the transmitted data is encoded in the data transmission so that the error can be corrected without retransmitting the data, and in the data reception. The procedure for decrypting the received data and
A communication failure element including periodic noise based on at least one of the results of measuring the success or failure of data communication via the wireless network including whether or not the error can be corrected and the radio wave environment of the wireless network. And the procedure for estimating the noise generation pattern including the occurrence timing of the above and the duration of the communication failure element.
Based on the noise generation pattern, the time during which the transmitted data does not normally reach the receiving device even if the data is transmitted to the wireless network is set, and the wireless during the time during which the transmitted data does not reach normally. The procedure for waiting for the transmission of the transmission data to the network and
A wireless program characterized by being equipped with.