Wireless communication system, wireless collection device, wireless communication method, and wireless communication program

Abstract

The purpose of the present disclosure is to provide a wireless collection device capable of saving the capacity of a storage device that stores CSI. A wireless communication system according to the present disclosure comprises: a base station that transmits a wireless frame; and a wireless collection device that continuously collects the wireless frame. The wireless collection device has a storage device. The wireless collection device derives CSI from the wireless frame as a function of time. Furthermore, the wireless collection device determines, for the derived CSI, whether or not the magnitude of time variation in a predetermined period is greater than or equal to a threshold value. Furthermore, when it is found that the magnitude is greater than or equal to the threshold value, the wireless collection device stores the derived CSI in the storage device.

Description

Wireless communication system, wireless collection device, wireless communication method, and wireless communication program

[0001] The present disclosure relates to a wireless communication system, a wireless collection device, a wireless communication method, and a program for wireless communication.

[0002] In LTE / 5G (Long Term Evolution / fifth generation mobile communication system) and wireless LAN communication, a technique for estimating channel quality or a technique for measuring the movement of an object present in a propagation path by using propagation channel information (Channel State Information, hereinafter referred to as CSI) has been disclosed (see, for example, Patent Documents 1 and 2).

[0003] Bird and animal detection system using wireless LAN radio waves, NTT Technical Journal, April 2019. OAI 5G RAN PROJECT GROUP, OpenAirInterface 5G Radio Access Network Project, 5G RAN OpenAirInterface, https: / / openairinterface.org / oai-5g-ran-project / , accessed January 9, 2024

[0004] Incidentally, small time fluctuations in CSI mean that there are no large fluctuations in channel quality. Furthermore, even if the movement of the measurement target is estimated from CSI with small time fluctuations, the estimation accuracy can be said to be low. Therefore, CSI with small time fluctuations can be said to have little utility. However, in the above-mentioned method, the derived CSI is stored in a storage device regardless of the magnitude of time fluctuations. This creates a problem in that the storage capacity cannot be saved because CSI with little utility is stored.

[0005] In order to solve the above-mentioned problems, a first object of the present disclosure is to provide a wireless communication system that can save the capacity of a storage device that stores CSI.

[0006] A second object of the present disclosure is to provide a wireless collection device that can save the capacity of a storage device that stores CSI.

[0007] A third object of the present disclosure is to provide a wireless communication method that can save the capacity of a storage device that stores CSI.

[0008] A fourth object of the present disclosure is to provide a wireless communication program that can save the capacity of a storage device that stores CSI.

[0009] A first aspect of the present disclosure is preferably a wireless communication system comprising: a base station that transmits wireless frames; and a wireless collection device that collects the wireless frames, wherein the wireless collection device has a storage device and is configured to perform the following: a derivation process that derives CSI from the wireless frames as a function of time; a determination process that determines whether the magnitude of time fluctuation of the derived CSI over a predetermined period is equal to or greater than a threshold; and a storage process that stores the derived CSI in the storage device if it is determined that the magnitude is equal to or greater than the threshold.

[0010] In addition, a second aspect is preferably a wireless communication system comprising: a base station that transmits wireless frames; a wireless collection device that collects the wireless frames; and a detection device whose detection range is the communication area of ​​the base station, wherein the detection device is configured to perform a determination process of determining whether a target object, which is any one of a user, a user device, and a measurement object by the wireless frames, has been detected, and a process of sending a detection notification including information on the detection time to the wireless collection device if detection is confirmed, and the wireless collection device has a storage device and is configured to perform a process of receiving the detection notification, a process of continuously deriving CSI for the wireless frames collected after the detection time, and a process of storing the derived CSI in the storage device.

[0011] A third aspect is preferably a wireless collection device having a storage device and configured to perform the following processes: collecting wireless frames from a base station; deriving CSI from the wireless frames as a function of time; determining whether the magnitude of time fluctuation of the derived CSI over a predetermined period of time is equal to or greater than a threshold; and, if it is determined that the magnitude is equal to or greater than the threshold, storing the derived CSI in the storage device.

[0012] Furthermore, a fourth aspect is preferably a wireless communication method including: a base station transmitting wireless frames; a wireless collection device collecting the wireless frames; deriving CSI from the wireless frames as a function of time; determining whether the magnitude of time fluctuation of the derived CSI over a predetermined period is equal to or greater than a threshold; and, if it is determined that the magnitude is equal to or greater than the threshold, storing the derived CSI in a storage device.

[0013] A fifth aspect is preferably a wireless communication program including a program that causes a wireless collection device to execute the following processes: a process of collecting wireless frames from a base station; a process of deriving CSI from the wireless frames as a function of time; a process of determining whether the magnitude of time fluctuation of the derived CSI over a predetermined period of time is equal to or greater than a threshold; and a process of storing the derived CSI in a storage device if it is determined that the magnitude is equal to or greater than the threshold.

[0014] According to a first aspect of the present disclosure, when the derived CSI is found to have large time variations, the wireless collection device stores the CSI in a storage device. According to a second aspect, the wireless collection device stores the CSI collected during the time when the user, the user equipment, or the measurement target via the wireless frame is detected by the detection device in a storage device. This allows the capacity of the storage device for storing the CSI to be saved.

[0015] 1 is a configuration example of a wireless communication system according to a first embodiment of the present disclosure; FIG. 2 is a configuration example of a wireless data collection device according to the first embodiment of the present disclosure; FIG. 3 is a flowchart of processing executed by the wireless data collection device according to the first embodiment of the present disclosure; FIG. 4 is a diagram showing a hardware configuration of the wireless data collection device according to the first embodiment of the present disclosure; FIG. 5 is a configuration example of a wireless communication system according to a modified example of the first embodiment of the present disclosure; FIG. 6 is a configuration example of a wireless data collection device according to a modified example of the first embodiment of the present disclosure;

[0016] Embodiments of the present disclosure will be described with reference to the drawings. The same or corresponding components will be designated by the same reference numerals, and repeated description may be omitted.

[0017] 1 shows an example of the configuration of a wireless communication system 100 according to a first embodiment of the present disclosure. The wireless communication system 100 includes a wireless base station (hereinafter referred to as a base station) 110 and a wireless collection device 140. Here, an example will be described in which the wireless collection device 140 collects wireless frames 10 from the base station 110 using a method based on IEEE 802.11ac / ax, which is a wireless LAN standard.

[0018] The base station 110 is equipped with one or more antennas. The base station 110 uses these antennas to communicate with the user equipment 50. The user equipment 50 is a mobile terminal such as a smartphone, or a fixed terminal such as a wireless LAN router.

[0019] The base station 110 also transmits a known radio frame 10 to the wireless collection device 140 .

[0020] The communication area 20 is an area in which the base station 110 performs wireless communication.

[0021] The wireless collection device 140 continuously collects wireless frames 10 from the base station 110 using one or more antennas 143 (not shown). Furthermore, the wireless collection device 140 calculates the difference between the collected wireless frames 10 and known frames, and derives CSI. The CSI includes amplitude information, phase information, timestamp information, and relative value information between the antennas of the wireless collection device 140 and the antenna of the base station 110. Based on the CSI, the wireless collection device 140 can measure the measurement target 60 present within the communication area 20, or estimate the channel quality.

[0022] If the derived CSI is deemed to have large time variations, the wireless collection device 140 stores the CSI in a storage device 170 (not shown).

[0023] Although the present embodiment shows a case where there is one base station 110 and one wireless collection device 140, there may be a plurality of each.

[0024] Although the method in which the wireless collection device 140 collects wireless frames 10 from the base station 110 and derives CSI has been described above based on IEEE 802.11ac / ax, the method for collecting wireless frames 10 is not limited to this. For example, in LTE / 5G, it is possible to collect wireless frames 10 and derive CSI by using Open Air Interface (OAI), which is Open Source Software (OSS).

[0025] The magnitude of the CSI fluctuation may be calculated in the form of a variance value. By using a variance value, it is possible to reduce the influence of noise and the like contained in the CSI through statistical effects. Furthermore, the magnitude of the CSI fluctuation may be calculated in the form of a moving variance value or a moving average value. Alternatively, the magnitude of the fluctuation may be calculated using the amplitude difference and phase difference of the CSI as targets.

[0026] 2 shows an example of the configuration of the wireless data collection device 140 according to the first embodiment of the present disclosure. The wireless data collection device 140 includes a CSI derivation circuit 141, a control circuit 142, an antenna 143, and a storage device 170.

[0027] The CSI derivation circuit 141 continuously collects radio frames 10 via the antenna 143 and executes a process (derivation process) of deriving CSI as a function of time from the radio frames 10. The CSI derivation circuit 141 notifies the control circuit 142 of the CSI derived as a function of time.

[0028] The control circuit 142 calculates the magnitude of time fluctuation of the derived CSI over a predetermined period and executes a process (determination process) to determine whether the magnitude of the time fluctuation is equal to or greater than a threshold. If it is determined that the magnitude is equal to or greater than the threshold, the control circuit 142 executes a process (storage process) to store the derived CSI in the storage device 170. On the other hand, if it is not determined that the magnitude is equal to or greater than the threshold, the control circuit 142 discards the derived CSI without storing it.

[0029] The control circuit 142 determines the time variation of the CSI newly notified from the CSI derivation circuit 141 over a set period as described above, and determines whether or not to store the CSI in the storage device 170 by threshold judgment.

[0030] The CSI derivation circuit 141 may further perform a process of measuring the movement, shape, etc. of the measurement target 60 present in the communication area 20 based on the derived CSI. Alternatively, the CSI derivation circuit 141 may further perform a process of estimating channel quality based on the derived CSI and feeding it back to the base station 110.

[0031] The control circuit 142 may determine preferred values ​​of transmission parameters for the base station 110 when transmitting the radio frame 10 and feed them back to the base station 110. The transmission parameters here refer to the timing, duration, interval, transmission power, beamforming angle, etc., of the radio frame 10 transmitted by the base station 110. This enables the base station 110 to transmit the radio frame 10 more efficiently. In this case, for example, the control circuit 142 may store a table that associates the magnitude of time fluctuation of CSI with preferred values ​​of transmission parameters. The control circuit 142 calculates the time fluctuation of CSI and determines preferred values ​​by referring to the table based on the result. The control circuit 142 then notifies the base station 110 of the determined preferred values. The base station 110 then changes the transmission parameters to the notified preferred values ​​and transmits the radio frame 10.

[0032] The storage device 170 may be, for example, a volatile or non-volatile semiconductor memory such as a RAM, a ROM, or a flash memory, or a magnetic disk, a flexible disk, an optical disk, a DVD, etc. The storage device 170 may be located outside the wireless data collection device 140 as a server or a cloud server.

[0033] The functions of the control circuit 142 and the CSI derivation circuit 141 of the wireless data collection device 140 may also be implemented in a server or a cloud server.

[0034] 3 is a flowchart of processing executed by the wireless collection device 140 according to the first embodiment of the present disclosure. First, the CSI derivation circuit 141 collects radio frames 10 from the base station 110 (step S01). Next, the CSI derivation circuit 141 derives CSI from the radio frames 10 as a function of time (step S02). Furthermore, the control circuit 142 determines whether the magnitude of time fluctuation of the derived CSI over a predetermined period is equal to or greater than a threshold (step S03). If it is determined that the magnitude is equal to or greater than the threshold, the control circuit 142 stores the derived CSI in the storage device 170 (step S04). On the other hand, if it is determined that the magnitude is not equal to or greater than the threshold, the control circuit 142 discards the derived CSI (step S05). These steps are then repeated for newly collected CSI by the CSI derivation circuit 141.

[0035] In step S03, it may be determined whether the time period during which the magnitude of the time variation is equal to or greater than a threshold continues for a certain period of time or more. This makes it possible to store in the storage device 170 CSI whose time variation is deemed to be particularly significant.

[0036] 4 is a diagram showing the hardware configuration of the wireless data collection device 140 according to the first embodiment of the present disclosure. The processing performed by the wireless data collection device 140 may be executed by a program using a computer including a CPU (Central Processing Unit, also referred to as a processor) and memory, with a program stored in the memory. Alternatively, the processing may be executed by a program using an integrated circuit such as an FPGA (Field Programmable Gate Array). The program may be provided by being recorded on a storage medium or via a network.

[0037] The wireless data collection device 140 has an input unit 40, an output unit 41, a communication unit 42, a CPU 43, a memory 44, and an HDD 45 connected via a bus 46, and functions as a computer. The wireless data collection device 140 is also configured to input and output data to and from a computer-readable storage medium 47.

[0038] The input unit 40 is, for example, a keyboard and a mouse, etc. The output unit 41 is, for example, a display device such as a display.

[0039] The communication unit 42 is, for example, a communication interface that communicates with a wireless device to be controlled.

[0040] The CPU 43 controls each component of the wireless data collection device 140 and performs predetermined processing, etc. The memory 44 and HDD 45 are the storage device 170 described above that stores data, etc.

[0041] The storage medium 47 is capable of storing wireless communication programs and the like that cause the wireless data collection device 140 to execute the functions of the wireless data collection device 140. Note that the architecture that configures the wireless data collection device 140 is not limited to the example shown in the figure.

[0042] As described above, in this embodiment, when the derived CSI is determined to have large temporal fluctuations, the wireless data collection device 140 stores the CSI in the storage device 170. This makes it possible to provide a wireless communication system, a wireless data collection device, a wireless communication method, and a wireless communication program that can save the capacity of the storage device that stores the CSI.

[0043] <Modification 1> The wireless collection device 140 may store the CSI at a first interval even when it is determined that the magnitude of the time fluctuation of the CSI is not equal to or greater than the threshold. On the other hand, when it is determined that the magnitude of the time fluctuation is equal to or greater than the threshold, the CSI is stored at a second interval that is shorter than the first interval. This provides the same effect as in embodiment 1.

[0044] <Modification 2> Figure 5 shows an example configuration of a wireless communication system 100 according to a modification of the first embodiment of the present disclosure. When multiple base stations 110 are used and correlation is found between the CSI derived from the radio frames 10 transmitted from each base station 110, only the CSI derived from the radio frame 10 with the highest received power may be stored. This enables selective storage of the CSI with the best S / N ratio. In this case, the wireless data collection device 140 derives CSI from each of the radio frames 10 transmitted from the multiple base stations 110. Furthermore, the wireless data collection device 140 determines whether any of the derived CSI is correlated with each other, for example, based on the temporal behavior of the CSI. If any of the derived CSI is correlated with each other, the wireless data collection device 140 references the received power of the radio frame 10 that was the source of the CSI, and determines the CSI derived from the radio frame 10 with the highest received power. Furthermore, the time variation of the determined CSI is calculated using the method described above. If the magnitude of the time variation is equal to or greater than a threshold, the CSI is stored in the storage device 170.

[0045] It is also possible to store only the CSI with the greatest time fluctuation among the CSIs that are correlated with each other. Alternatively, the source base station 110 that stores the CSI may be changed every certain period of time. <Variation 3> Fig. 6 shows an example configuration of a wireless collection device 140 according to a variation of the first embodiment of the present disclosure. CSI derived in multiple wireless collection devices 140 may be stored in a storage device 170 arranged outside the wireless collection device 140. It is possible to manage multiple wireless collection devices 140 with a single storage device 170.

[0046] Second Embodiment The following describes changes from the first embodiment.

[0047] 7 illustrates a configuration example of a wireless communication system 100 according to a second embodiment of the present disclosure. The wireless communication system 100 of this embodiment includes a base station 110, a wireless data collection device 140, and a detection device 150. The detection device 150 has a detection range that is the communication area 20 or a part of the area, and detects physical quantities such as sound, heat, light, infrared rays, and ultraviolet rays.

[0048] For example, by using the sound detection device 150, the presence of a target object can be confirmed by detecting the sound emitted by the target object, which can be a user (not shown), a user device 50, or a measurement object 60 measured by the wireless frame 10.

[0049] It should be noted that the user here is not limited to the owner of the user device 50, but also includes users who handle other user devices.

[0050] The detection device 150 determines whether a target physical quantity has been detected in the communication area 20. If detection is confirmed, the detection device 150 transmits a detection notification including information on the time of detection to the wireless collection device 140.

[0051] After transmitting the detection notification, the detection device 150 determines whether the target physical quantity continues to be detected. If the detection is no longer confirmed, the detection device 150 transmits a non-detection notification to the wireless collection device 140.

[0052] The wireless collection device 140 continuously collects wireless frames 10 from the base station 110, as in the first embodiment. Upon receiving a detection notification, the wireless collection device 140 reads the detection time information from the detection notification and continuously derives CSI for the wireless frames 10 collected after the detection time. The wireless collection device 140 then stores the derived CSI in the storage device 170.

[0053] Furthermore, upon receiving the non-detection notification, the wireless collection device 140 stops deriving and storing the CSI.

[0054] In this manner, in this embodiment, the wireless collection device 140 stores the CSI collected during the time when the target object is detected by the detection device 150. This provides the same effects as in the first embodiment.

[0055] <Modification 4> The detection device 150 may also be a camera that captures images of the communication area 20 or a part of it as its detection range. The camera analyzes the captured image and determines whether a target object has been detected. If detection is confirmed, the camera transmits a detection notification to the wireless collection device 140. This provides the same effect as in embodiment 2.

[0056] As described above, the present disclosure can provide a wireless communication system, a wireless collection device, a wireless communication method, and a wireless communication program that can save the capacity of a storage device that stores CSI.

[0057] The present disclosure is not limited to the above-described embodiments, and various modifications can be made in the implementation stage without departing from the spirit of the present disclosure. Furthermore, the embodiments and modifications may be implemented in appropriate combinations, in which case the combined effects can be obtained.

[0058] <Correspondence to Terms Used in the Claims> The detection device 150 and the camera described in the second embodiment are collectively referred to as a detection device in the claims.

[0059] 10 wireless frame, 20 communication area, 40 input unit, 41 output unit, 42 communication unit, 43 CPU, 44 memory, 46 bus, 47 storage medium, 50 user equipment, 60 measurement target, 100 wireless communication system, 110 wireless base station, 140 wireless collection device, 141 CSI derivation circuit, 142 control circuit, 143 antenna, 150 detection device, 170 storage device

Claims

1. A wireless communication system comprising: a base station that transmits wireless frames; and a wireless collection device that collects the wireless frames, wherein the wireless collection device has a memory device and is configured to perform the following: a derivation process that derives CSI from the wireless frames as a function of time; a determination process that determines whether the magnitude of time fluctuation of the derived CSI over a predetermined period of time is greater than or equal to a threshold; and a storage process that stores the derived CSI in the memory device if it is determined to be greater than or equal to the threshold.

2. The wireless communication system described in claim 1, wherein the wireless collection device further executes a process of storing the CSI in the storage device at a first interval if the magnitude of the time fluctuation is not found to be equal to or greater than the threshold in the determination process, and stores the CSI in the storage device at a second interval shorter than the first interval in the storage process.

3. The wireless communication system according to claim 1 or 2, wherein there are a plurality of base stations, and the wireless collection device is further configured to perform the following processes: deriving CSI from each of the wireless frames transmitted from the plurality of base stations; determining whether or not the derived CSI contains CSI that is correlated with each other; and, if there is CSI that is correlated with each other, referencing the power at the time of reception of the wireless frame that was the basis of the CSI; and determining the CSI derived from the wireless frame with the highest power, and wherein the derivation process, the determination process, and the storage process are performed on the determined CSI.

4. The wireless communication system according to claim 1 or 2, wherein the wireless collection device is further configured to execute a process of determining a preferred value of a transmission parameter for the base station when transmitting the wireless frame based on the magnitude of the time fluctuation, and a process of notifying the base station of the preferred value, and the base station is configured to execute a process of changing the transmission parameter to the preferred value and transmitting the wireless frame.

5. A wireless communication system comprising: a base station that transmits wireless frames; a wireless collection device that collects the wireless frames; and a detection device whose detection range is the communication area of the base station, wherein the detection device is configured to perform a determination process of determining whether a target object, which is either a user, a user device, or a measurement object by the wireless frames, has been detected, and a process of sending a detection notification including information on the detection time to the wireless collection device if detection is confirmed, and the wireless collection device has a memory device and is configured to perform a process of receiving the detection notification, a process of continuously deriving CSI for the wireless frames collected after the detection time, and a process of storing the derived CSI in the memory device.

6. A wireless collection device having a storage device and configured to perform the following processes: collecting wireless frames from a base station; deriving CSI from the wireless frames as a function of time; determining whether the magnitude of time fluctuation of the derived CSI over a predetermined period of time is greater than or equal to a threshold; and, if it is determined that the magnitude is greater than or equal to the threshold, storing the derived CSI in the storage device.

7. A wireless communication method comprising: a base station transmitting wireless frames; a wireless collection device collecting the wireless frames; deriving CSI from the wireless frames as a function of time; determining whether the magnitude of time fluctuation of the derived CSI over a predetermined period of time is greater than or equal to a threshold; and if it is determined that the magnitude is greater than or equal to the threshold, storing the derived CSI in a storage device.

8. A wireless communication program including a program that causes a wireless collection device to execute the following processes: a process of collecting wireless frames from a base station; a process of deriving CSI from the wireless frames as a function of time; a process of determining whether the magnitude of time fluctuation of the derived CSI over a predetermined period of time is equal to or greater than a threshold; and a process of storing the derived CSI in a storage device if it is determined to be equal to or greater than the threshold.

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