WO2024038521A1

WO2024038521A1 - Wireless communication system, wireless terminal device, wireless base station, controller, and wireless communication method

Info

Publication number: WO2024038521A1
Application number: PCT/JP2022/031090
Authority: WO
Inventors: 花絵大谷; ヒランタアベセカラ; 裕介淺井; 泰司鷹取; 朗岸田
Original assignee: 日本電信電話株式会社
Priority date: 2022-08-17
Filing date: 2022-08-17
Publication date: 2024-02-22

Abstract

The present disclosure relates to a wireless communication system, the purpose of the present disclosure being to enable a terminal transmitting low-priority frames to be granted a transmission opportunity without causing a channel to be saturated with high-priority frames in wireless communication and realize priority frame control between terminals. A wireless communication system according to the present disclosure grants, in accordance with the priority of wireless frames, wireless frame transmission/reception opportunities preferentially to a wireless terminal device that should wirelessly communicate with a wireless base station from among a plurality of wireless terminal devices, the wireless communication system comprising the wireless base station that wirelessly communicates with the plurality of wireless terminal devices. The wireless base station is configured to execute a process for determining, for each of the plurality of wireless terminal devices, an upper-limit value representing the number of times that wireless frames having high priority can be transmitted, and issuing notification of the upper-limit value. The plurality of wireless terminal devices are configured to execute a process for transmitting wireless frames having high priority until the upper-limit value is reached, and furthermore counting the number of instances of transmission.

Description

Wireless communication system, wireless terminal device, wireless base station, controller, and wireless communication method

The present disclosure relates to a wireless communication system, a wireless terminal device, a wireless base station, a controller, and a wireless communication method related to frame control of wireless communication.

The number of devices such as smartphones that connect to the Internet wirelessly has been on the rise in recent years. Furthermore, the use of applications and the like is also increasing. As a result, from text messaging to AR/VR, traffic quality requirements, and thus traffic priorities, are becoming more diverse.

In wireless LAN (Local Area Network) communication, the standard IEEE 802.11 is widely used. There, wireless access control is performed using a CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) algorithm. CSMA/CA is a mechanism in which when multiple terminals share the same frequency channel, each terminal independently controls the frame transmission timing to prevent the terminals from transmitting frames at the same time as other terminals.

Non-Patent Document 1 discloses a method of implementing identification information called QoS color (Quality of Service color, hereinafter referred to as high priority frame) in a frame according to traffic priority in CSMA/CA. By providing the frame with information regarding the priority, it is possible to give preferential access to the channel to a terminal that attempts to transmit a high-priority frame. As a result, interference control can be performed to satisfy the required quality of traffic.

However, if each terminal transmits as many high-priority frames as it wants, a problem arises in that the channel becomes saturated with high-priority frames and opportunities to transmit low-priority frames are no longer secured. In addition, if the channel is saturated with high-priority frames, a problem arises in that priority control between terminals cannot be realized because all frames have the same priority.

In order to solve the above-mentioned problems, the present disclosure can provide a transmission opportunity to a terminal that transmits a low-priority frame without saturating the channel with high-priority frames in wireless communication, and realizes priority frame control between terminals. The primary objective is to provide a wireless communication system that can

Further, the present disclosure provides a wireless communication system that can provide a transmission opportunity to a terminal that transmits a low priority frame without saturating the channel with high priority frames in wireless communication, and can realize priority frame control between terminals. The second purpose is to provide a terminal device.

Further, the present disclosure provides a wireless communication system that can provide a transmission opportunity to a terminal that transmits a low priority frame without saturating the channel with high priority frames in wireless communication, and can realize priority frame control between terminals. The third purpose is to provide base stations.

Further, the present disclosure provides a controller that can provide a transmission opportunity to a terminal that transmits a low priority frame without saturating the channel with high priority frames in wireless communication, and can realize priority frame control between terminals. The fourth purpose is to provide

Further, the present disclosure provides a wireless communication system that can provide a transmission opportunity to a terminal that transmits a low priority frame without saturating the channel with high priority frames in wireless communication, and can realize priority frame control between terminals. The fifth purpose is to provide a communication method.

A first aspect of the present disclosure provides an opportunity to transmit and receive a radio frame preferentially to a radio terminal device that should perform radio communication with a radio base station among a plurality of radio terminal devices according to the priority of the radio frame. A wireless communication system that provides
The wireless base station that performs wireless communication with the plurality of wireless terminal devices,
Upper limit determination processing for determining, for each of the plurality of wireless terminal devices, an upper limit value of the number of times the wireless frame with the high priority can be transmitted by the wireless terminal device;
upper limit notification processing for notifying each of the plurality of wireless terminal devices of the upper limit value of the number of transmissions;
is configured to run
The plurality of wireless terminal devices transmit the high-priority wireless frames until the upper limit of the number of transmissions is reached;
a counting process for counting the number of times the high-priority wireless frame is transmitted;
Preferably, the system is configured to perform the following steps.

Further, a second aspect is a wireless terminal device that performs wireless communication using a wireless frame having identification information indicating priority,
a process of receiving information on an upper limit value of the number of times the radio frame with a high priority can be transmitted from another radio station;
a process of transmitting the radio frame with the high priority until the upper limit is reached;
Preferably, the system is configured to perform the following steps.

Further, a third aspect is a wireless base station that performs wireless communication with a plurality of wireless terminal devices using a wireless frame having identification information indicating priority,
Upper limit value determination processing for determining and notifying, to each of the plurality of wireless terminal devices, an upper limit value for the number of times the wireless frame with a high priority can be transmitted by the wireless terminal device;
or,
a second upper limit value determination process for determining, for each of the plurality of wireless terminal devices, an upper limit value of the number of times the wireless frame with high priority can be received by the wireless terminal device;
do at least one,
When the second upper limit value determination process is executed, for each of the plurality of wireless terminal devices, the number of reception times reaches the upper limit value determined in the second upper limit value determination process. Preferably, the wireless communication device is configured to further execute processing for transmitting a radio frame with a high priority.

Further, a fourth aspect is a controller that controls a wireless base station that performs wireless communication with a plurality of wireless terminal devices using a wireless frame having identification information indicating priority,
at least an upper limit value of the number of times of transmission and reception of high-priority radio frames that each of the plurality of wireless terminal devices can transmit or receive, or a sum of the upper limit value of the number of times of transmission and reception in each of the plurality of wireless terminal devices; Preferably, the wireless base station is configured to determine one of the two and to notify the wireless base station.

Furthermore, the fifth aspect is to give a wireless frame transmitting/receiving opportunity preferentially to a wireless terminal device that should wirelessly communicate with a wireless base station among the plurality of wireless terminal devices according to the priority of the wireless frame. A wireless communication method,
The wireless base station that performs wireless communication with the plurality of wireless terminal devices,
a process of determining, for each of the plurality of wireless terminal devices, an upper limit value for the number of times the wireless frame with a high priority can be transmitted by the wireless terminal device;
a process of notifying each of the plurality of wireless terminal devices of the upper limit value of the number of times of transmission;
Run
The plurality of wireless terminal devices transmit the high-priority wireless frames until the upper limit of the number of transmissions is reached;
a process of counting the number of times the high-priority radio frame has been transmitted;
It is preferable to carry out.

According to the first to fifth aspects of the present disclosure, it is possible to give a transmission opportunity to a terminal that transmits a low-priority frame without saturating a channel with high-priority frames in wireless communication, and to control priority frames between terminals. It becomes possible to provide a wireless communication system, a wireless terminal device, a wireless base station, a controller, and a wireless communication method that can realize the following.

FIG. 2 is a diagram illustrating a configuration example of a conventional wireless communication system according to a comparative example. 2 is an example of a wireless communication sequence in a conventional wireless communication system according to a comparative example. 1 is a diagram showing a configuration of a wireless communication system according to Embodiment 1 of the present disclosure. FIG. 2 is a block diagram showing an example of the functional configuration of a terminal and a base station. FIG. 2 is a block diagram illustrating a detailed functional configuration example of a MAC section of a base station when transmitting a wireless signal. FIG. 2 is a block diagram illustrating a detailed functional configuration example of a MAC section of a base station when receiving a wireless signal. FIG. 2 is a block diagram illustrating a detailed functional configuration example of a MAC section of a terminal when transmitting a wireless signal. FIG. 2 is a block diagram illustrating a detailed functional configuration example of a MAC section of a terminal when receiving a wireless signal. FIG. 2 is a block diagram illustrating a detailed functional configuration example of a PHY transmitter of a base station. FIG. 2 is a block diagram showing a detailed functional configuration example of a PHY receiving section of a base station. 2 is a flowchart of a process in which a base station notifies terminals under its control of an upper limit value of a counter according to Embodiment 1 of the present disclosure. 2 is a flowchart of processing performed by a terminal when transmitting a high-priority frame according to Embodiment 1 of the present disclosure. 1 is an example of a wireless communication sequence in a wireless communication system according to Embodiment 1 of the present disclosure. FIG. 2 is a diagram showing the configuration of a wireless communication system according to Embodiment 2 of the present disclosure. FIG. 2 is a block diagram illustrating an example of a functional configuration of a controller, a base station, and a terminal according to Embodiment 2 of the present disclosure. 12 is a flowchart of a process for notifying a BSS total value from a controller to a base station according to Embodiment 2 of the present disclosure. 11 is a flowchart of a process in which a base station, which has been notified of a BSS total value from a controller, notifies terminals under its control of an upper limit value of a counter based on that information, according to Embodiment 2 of the present disclosure.

Comparative Example First, a conventional technique will be described as a comparative example. FIG. 1 is a diagram showing a configuration example of a conventional wireless communication system according to a comparative example. A conventional wireless communication system 100 includes a plurality of wireless terminal devices (hereinafter referred to as terminals) 110(1), 110(2), and 110(3).

The terminal 110 performs wireless communication with the wireless base station 120 based on the IEEE 802.11 standard. The terminal 110 is a general-purpose terminal such as a smartphone. Alternatively, it may be a terminal installed in a factory or the like and used for a special purpose such as monitoring and controlling machines.

A radio base station (hereinafter referred to as a base station) 120 receives radio waves from the terminal 110 and connects to the core network, or conversely, converts signals from the core network into radio waves and transmits them to the terminal 110. It is a wireless base station. Note that when the applied wireless communication system is Wi-Fi (registered trademark), the base station 120 corresponds to an access point.

FIG. 2 is an example of a wireless communication sequence in a conventional wireless communication system according to a comparative example.

The plurality of terminals 110(1), 110(2), 110(3) and base station 120 each access a channel and transmit data based on the CSMA/CA algorithm.

The radio frames transmitted by the terminal 110 are prioritized. In the example of FIG. 2, first, terminal 110(1) transmits high priority frame 103(1) to base station 120. Upon receiving the high priority frame 103(1), the base station 120 returns an ACK frame 104(1) to the terminal 110(1) as proof that the data has been received normally.

When the other terminals 110(2) and 110(3) detect that a terminal other than themselves is performing data communication, they set themselves to a busy state 105 and wait until the current communication ends. do.

When the data communication of terminal 110(1) ends, terminal 110(2) then transmits high priority frame 103(2). Base station 120 returns an ACK frame 104(2) to terminal 110(2). Meanwhile, other terminals 110(1), 110(3) are in a busy state 105.

As described above, in the conventional technology, the terminal 110 that transmitted the high priority frame 103 accesses the channel preferentially and transmits data to the base station 120. However, since each terminal transmits high-priority frames without limit, terminals like terminal 110 (3) that try to transmit frames that are not high-priority transmit their own data while remaining in the busy state 105. I can't.

As explained above, in the conventional wireless communication system 100, a terminal attempting to transmit a low-priority wireless frame is not given an opportunity to transmit.

Note that in the example of FIG. 2, an uplink case in which data is transmitted from the terminal 110 to the base station 120 has been described. However, data may be transmitted from the base station 120 to the terminal 110, that is, in the case of downlink.

Embodiment 1
FIG. 3 is a diagram showing the configuration of a wireless communication system according to Embodiment 1 of the present disclosure. The wireless communication system 200 includes a plurality of terminals 110 and a base station 120, similarly to the comparative example. Further, in the wireless communication system 200 of the present embodiment, frame counters 130(1), 130(2), and 130(3) are respectively set in the terminal 110, unlike the comparative example.

The frame counter (hereinafter referred to as a counter) 130 is a part that performs processing related to the number of times the terminal 110 transmits a high priority frame. Each terminal 110 transmits the high priority frame 103 until the count value of the counter 130 reaches the upper limit. The upper limit value is set from the base station 120 to each terminal 110 under its control. For example, in the example of FIG. 3, upper limit values a, b, and c are set for the counters 130 of terminals 110(1), 110(2), and 110(3), respectively.

The upper limit values a, b, and c of the counter 130 are set so that the sum (a+b+c) does not exceed a predetermined value A. That is, the settings are made so that the following conditional expression is satisfied.
a+b+c≦A (Formula 1)

In this way, in the wireless communication system 200 of this embodiment, the number of times each terminal 110 can transmit the high priority frame 103 is limited.

Note that the upper limit value of the counter 130 may be set only for a single channel, or may be set across multiple channels, links, or frequency bands. By setting across multiple channels and links, the count value can be increased fairly even when the number of transmissions of the high priority frame 103 is insufficient on a single link and multiple channels and frequency bands are also used for transmission. be able to.

FIG. 4 is a block diagram showing an example of the functional configuration of a terminal and a base station. However, here, for the sake of explanation, it is assumed that there is one terminal 110, but in reality, a plurality of terminals 110 are provided.

First, the functions of the base station 120 during wireless signal transmission will be described. First, a packet is input to the base station 120 from the upper layer 140. Here, the upper layer 140 refers to a layer higher than the physical (PHY) layer and the data link layer among the layers defined in the OSI (Open Systems Interconnection) reference model. The upper layer 140 is, for example, an application layer.

For packets input from the upper layer 140, the base station 120 performs frame processing such as adding or deleting information to the physical layer and data link layer frames based on the IEEE802.11 frame format. Note that the data link layer further includes an LLC (Logical Link Control) sublayer and a MAC (Media Access Control) sublayer, and the base station 120 processes each sublayer.

The LLC unit 150 is an interface with the upper layer 140, and is a part that performs LLC layer processing on packets input from the upper layer 140. Specifically, a process is performed in which a header such as DSAP (Destination Service Access Point) or SSAP (Source Service Access Point) is added to the packet and the packet is input to the MAC unit 160.

The MAC unit 160 is a part that performs MAC layer processing. The MAC unit 160 sends a MAC address to the packet input from the LLC unit 150, including a destination address, a source address, a sequence number, a traffic type (Traffic Identifier, TID) indicating data priority, an error detection code, etc. Add header.

Furthermore, when notifying the terminal 110 of the upper limit value of the counter 130, the upper limit value determination unit 163 included in the MAC unit 160 performs processing to implement upper limit information in the MAC frame of the packet.

Furthermore, the MAC section 160 performs carrier sensing based on the CSMA/CA algorithm based on the received power input from the PHY receiving section 180 to determine whether frame transmission is possible. If transmission is possible, the data input into the MAC frame is output to the PHY transmitter 170.

The PHY transmitter 170 is a part that performs PHY layer processing. When a frame is input from the MAC unit 160, a wireless signal is generated by adding a PHY header, a preamble, etc. to the frame. The preamble includes a BSS (Basic Service Set) color, which is identification information of the base station 120 as the communication destination, a QoS color, which is identification information of frame priority, and the like.

The radio signal generated in the PHY transmitter 170 is transmitted from the antenna 190 and sent to the terminal 110.

In this way, the base station 120 performs frame processing on the data input from the upper layer 140 by the LLC section 150, the MAC section 160, and the PHY transmitting section 170, and generates a wireless signal directed to the terminal 110.

Next, when receiving a wireless signal, the base station 120 receives the wireless signal via its own antenna 190. The PHY receiving unit 180 demodulates the PHY header, preamble, etc. of the received radio signal.

The MAC unit 160 performs processing such as demodulating the MAC header when a packet is input from the PHY receiving unit 180, and inputting it to the LLC unit 150 when the data is addressed to its own station.

When a packet is input from the MAC unit 160, the LLC unit 150 deletes the above-mentioned header and then inputs the packet to the upper layer 140.

In this way, when the base station 120 receives a wireless signal addressed to itself, the PHY receiving section 180, MAC section 160, and LLC section 150 perform frame processing, and input the extracted data to the upper layer 140.

On the other hand, like the base station 120, the terminal 110 includes an LLC section 250, a MAC section 260, a PHY transmitting section 270, a PHY receiving section 280, and an antenna 290. Note that the functions of the LLC section 250, PHY transmitting section 270, PHY receiving section 280, and antenna 290 are the same as those of the base station 120 described above, so the description thereof will be omitted.

On the other hand, when transmitting the high priority frame 103, the MAC unit 260 of the terminal 110 performs processing to increase the count of the counter 130 based on the transmission information of the high priority frame 103 or CCA (Channel Clear Assessment) threshold information.

As described above using FIG. 4, the base station 120 implements information on the upper limit of the number of transmissions of the high priority frame 103 that each terminal can transmit in a MAC frame, and notifies each terminal 110 of the information. do. Furthermore, when the terminal 110 transmits the high-priority frame 103 to the base station 120, the counter 130 in the MAC unit 260 of the terminal performs a process of increasing the count.

Here, in FIG. 4, for the sake of explanation, the processing functions in the PHY layer are divided into transmission and reception, and are shown separately as a PHY transmitter 170 and a PHY receiver 180, respectively. However, these functions are originally performed in the processing section of one PHY layer. It should be noted that base station 120 and terminal 110 do not have multiple PHY layer processing units with different functions.

FIG. 5 is a block diagram illustrating a detailed functional configuration example of the MAC unit of the base station during wireless signal transmission.

After a packet is input from the LLC unit 150, the data processing unit 161 adds a MAC header in which information such as a destination address or TID indicating the priority of data is written to the packet. Furthermore, the data with the MAC header added is output to the MAC frame processing unit 162.

The MAC frame processing unit 162 performs carrier sensing over a random period of time based on the CSMA/CA algorithm, and receives notifications regarding channel conditions such as received power received by the PHY receiving unit 180. If the channel is found to be in an idle state by comparison with the CCA threshold, the data input from the data processing section 161 is output to the PHY transmission section 170.

In addition, in order to deal with the exposed terminal problem and ensure low delay of the high-priority frame 103, the CCA threshold is determined according to the combination of BSS color and QoS color values included in the frame of the radio signal received during carrier sensing. You may.

The upper limit value determination unit 163 determines the upper limit value of the counter 130 for each of the terminals 110 under its control, and implements the information in the MAC frame.

The upper limit value of the counter 130 is determined according to the communication load of each terminal 110, such as the load data rate of each terminal 110. Thereby, the opportunity to transmit the high priority frame 103 can be distributed more fairly to each terminal 110.

Alternatively, the upper limit value can be biased so that more high-priority frames 103 can be transmitted to at least one terminal depending on the priority of the terminal. Furthermore, the upper limit value of the counter 130 can be determined according to changes in the number of subordinate terminals 110, changes in the communication environment, and increases and decreases in communication resources.

Note that the upper limit value of the counter 130 is determined to satisfy the above (Formula 1) in any of the above-described determination methods.

As explained above, the base station 120 determines the upper limit value of the counter 130 for each terminal 110 in the upper limit value determining section 163 in the MAC section 160. This makes it possible to control the fairness of the number of times the high priority frame 103 is transmitted.

FIG. 6 is a block diagram showing a detailed functional configuration example of the MAC section of the base station when receiving a wireless signal.

First, a frame addressed to the own BSS is detected in the PHY receiving unit 180, and a MAC frame is input from the PHY receiving unit 180. Then, the MAC frame processing unit 162 demodulates the MAC header. Further, the demodulated data is output to the data processing section 161.

The data processing unit 161 refers to the MAC header of the input data, extracts the data, and inputs it to the LLC unit 150.

In this way, the MAC unit 160 of the base station 120 performs MAC layer processing when receiving a wireless signal, and passes the packet to the LLC unit 150 if the destination address included in the MAC header indicates the own station.

FIG. 7 is a block diagram illustrating a detailed functional configuration example of the MAC unit of the terminal during wireless signal transmission. As in the case of the base station 120, the MAC section 260 includes a data processing section 261 and a MAC frame processing section 262. These functions at the time of wireless signal transmission are the same as those of the base station 120, so a description thereof will be omitted.

On the other hand, unlike the base station 120, the MAC unit 260 of the terminal 110 includes a counter 130.

The counter 130 counts the high-priority frames 103 based on the transmission information of the high-priority frames 103 used by the MAC frame processing unit 262 during carrier sensing, or the selection information of the CCA threshold used for determining the channel state.

Regarding the counting method in the counter 130, for example, the count value is increased by 1 each time the high priority frame 103 is transmitted. Alternatively, the count number is weighted according to the communication control method implemented by the terminal 110 to transmit the high priority frame 103. Note that the communication control method is a method of controlling the transmission of the high priority frame 103 using transmission power, a CCA threshold, an MCS (Modulation and Coding Scheme) value, the number of frame retransmissions, and the like.

For example, if the terminal 110 increases the transmission power value and transmits the high-priority frame 103, it will be more easily received by the base station 120 than other terminals. Increase the value counted.

Also, when transmitting with a raised CCA threshold, it is easier to determine that the channel is in an idle state, and since the opportunity to transmit has been obtained, the count is counted at once compared to when transmitting without raising the CCA threshold. Increase the value.

Similarly, when transmitting a frame with a lowered MSC value, the transmission time is lengthened and the time to occupy the channel is lengthened to reduce transmission opportunities for other terminals 110, so the frame can be transmitted without lowering the MCS value. Increase the value to be counted at one time compared to the case. Alternatively, processing such as multiplying the count number by the reciprocal of the MCS value or the reciprocal of the MCS value multiplied by a constant is performed.

In this way, by weighting the count number according to the communication control method implemented by the terminal 110 to transmit the high-priority frame 103, more fair transmission opportunity control is performed between the terminals 110. be able to.

FIG. 8 is a block diagram showing a detailed functional configuration example of the MAC section of the terminal when receiving a wireless signal. As in the case of the base station 120, the MAC section 260 includes a data processing section 261 and a MAC frame processing section 262. These functions when receiving a radio signal are the same as those of the base station 120, so a description thereof will be omitted.

FIG. 9 is a block diagram showing a detailed functional configuration example of the PHY transmitter of the base station.

First, carrier sensing is performed in the MAC unit 160, and when a frame transmission right is acquired by determining that the channel is in an idle state, a MAC frame is input from the MAC unit 160 to the PHY transmitting unit 170.

The PHY header processing unit 171 receives the MAC frame from the MAC unit 160. The PHY header processing unit 171 generates a frame in which a PHY header including information such as BSS color and QoS color, a preamble, etc. are added to the MAC frame. Here, in assigning the QoS color, the TID information of the MAC header or the like may be referred to.

The wireless signal processing unit 172 converts the frame input from the PHY header processing unit 171 into a wireless signal. There, encoding 173, deinterleaver 174, modulation 175, Inverse Fast Fourier Transform (IFFT) 176, OFDM (Orthogonal Frequency Division Multiply) signal processing such as exing) modulation 177 and frequency conversion 178 in sequence. It will be done. Thereafter, radio frame transmission is performed from the antenna 190 regarding the converted radio signal.

In this way, the PHY transmitter 170 of the base station 120 can add information to the frame input from the upper layer, convert it into a wireless signal, and transmit it to the terminal 110.

Note that the functional configuration example of the PHY transmitter 270 of the terminal 110 is also the same as that of the base station 120 in FIG. 9, so the description thereof will be omitted.

FIG. 10 is a block diagram showing a detailed functional configuration example of the PHY receiving section of the base station. Note that the functions described here are performed not only during frame reception but also during carrier sense before frame transmission.

First, the radio signal processing unit 182 decodes the radio signal received by the antenna 190. There, signal processing is performed in the reverse order to that at the time of transmission. That is, signal processing including frequency conversion 188, OFDM modulation 187, fast Fourier transform (FFT) 186, demodulation 185, deinterleaver 184, decoding 183, etc. is performed in order. Thereafter, the obtained frame is output to the PHY header processing section 181.

The PHY header processing unit 181 receives the radio frame from the radio signal processing unit 182, and identifies information such as BSS color and QoS color included in the preamble of the radio frame. Note that the information on the BSS color and QoS color identified by the PHY header processing unit 181 may be input to the MAC unit 160 together with the payload without being deleted.

In this way, the PHY receiving unit 180 of the base station 120 can decode the wireless signal transmitted from another wireless base station and extract the information included in the frame.

Note that the functional configuration example of the PHY receiving unit 280 of the terminal 110 is also the same as that of the base station 120, so a description thereof will be omitted.

FIG. 11 is a flowchart of a process in which a base station notifies terminals under its control of the upper limit value of a counter, according to Embodiment 1 of the present disclosure.

First, the base station 120 starts processing (step 210). Next, a process is performed to determine whether a certain period of time has elapsed (step 211). If it is determined that a certain period of time has elapsed, the base station 120 determines the upper limit value of the counter 130 for each of the terminals 110 under its control (step 212). Information on the determined upper limit value of the counter 130 is notified to each terminal (step 213). Thereafter, the process ends (step 214).

As explained above using the flowchart, the base station 120 notifies the subordinate terminal 110 of the upper limit value of the counter 130 every predetermined period of time.

Here, upon notification of the upper limit value of the counter 130, the MAC unit 160 of the base station 120 may periodically evaluate the fairness of the upper limit value between the terminals 110 under its control using the Fairness index.

The Fairness index is calculated based on the communication quality of wireless communication in each terminal 110. Communication quality includes, for example, the count number of the counter 130 allocated to each terminal 110, transmission air time, throughput, delay time, PER (Packet Error Rate), MCS value, number of retransmitted packets, and RSSI (Received Signal Strength Indicator). ), SINR (Signal-to-Interference plus Noise power Ratio), etc.

For example, if transmission air time and throughput values are used as standards, it is evaluated whether communication opportunities are provided to each terminal 110 so that these values are equal.

Alternatively, when using RSSI as a reference, it is evaluated whether there is any bias in the degree of control of transmission power.

In this way, the MAC unit 160 of the base station 120 periodically calculates the Fairness index. If the calculation result exceeds the allowable value, fairness is controlled by changing the upper limit value of the counter 130, the transmission power value, or the CCA threshold value allocated to each terminal 110.

Note that returning to the flowchart of FIG. 11 again, the case where the trigger for re-notifying the upper limit value is the passage of a certain period of time has been described. However, for example, using the Fairness index, the time point when it is found that the desired fairness cannot be achieved may be used as a trigger.

Furthermore, regarding the trigger in FIG. 11, another example is a request for a count value that the terminal 110 makes to the base station when the upper limit of allocation is smaller than the number of high-priority frames that the terminal 110 should transmit. may be used as a trigger.

FIG. 12 is a flowchart of processing performed by a terminal when transmitting a high priority frame according to Embodiment 1 of the present disclosure. First, the terminal 110 starts processing (step 220). Next, the terminal 110 receives traffic from the upper layer 140 (step 221). Next, it is determined whether the traffic has a high priority (step 222). If the priority is not determined to be high, an attempt is made to transmit the frame as a low priority frame 106 (step 223).

On the other hand, if it is determined in step 222 that the priority is high, the counter 130 is referred to and a process is performed to determine whether the current count value is less than the upper limit value (step 224). If it is not less than the upper limit, it means that the count value has already reached the upper limit. Therefore, frame transmission is attempted as the low priority frame 106 (step 223). On the other hand, if the count value is less than the upper limit, 1 is added to the count of the counter 130, and frame transmission is attempted as the high priority frame 103 (step 225). Finally, the process ends (step 226).

In this way, the terminal 110 can transmit the high priority frame 103 within a certain period of time until the counter 130 reaches the upper limit. After the counter 130 reaches the upper limit value, the frame is transmitted not as a high priority frame 103 but as a normal low priority frame 106.

Note that in step 225, a method was described in which the count is increased by 1 each time the high priority frame 103 is transmitted. However, the counting method may be weighted according to the communication control method implemented by the terminal 110 to transmit the high priority frame 103, as described in FIG.

Note that even if the high priority frame 103 is transmitted in step 225, it may fail later. In step 225, the method of adding the count value of the counter 130 even in the case of failure is shown, but if the transmission of the high priority frame 103 fails, it is not necessary to add the count value.

FIG. 13 is an example of a wireless communication sequence in the wireless communication system according to Embodiment 1 of the present disclosure.

The counters 130 of the terminals 110(1), 110(2), and 110(3) are set with upper limit values a, b, and c for a certain period of time, respectively.

First, it is assumed that the terminal 110(1) transmits the high priority frame 103(1), and as a result, the counter 130(1) reaches the upper limit value a.

Next, after terminal 110(1) communicates, terminal 110(2) also transmits high priority frame 103(2). Similarly, it is assumed that the counter 130(2) of the terminal 110(2) has also reached the upper limit value b.

In such a case, terminal 110(1) and terminal 110(2) cannot transmit any more high-priority frames 103 until a certain period of time has elapsed. Then, the terminal 110(3), which had been in the busy state 105 until then, is given an opportunity to transmit the low priority frame 106.

In this way, in the wireless communication sequence implemented in the wireless communication system 200 according to the present embodiment, the terminal 110 that transmits the low priority frame 106 is also given a transmission opportunity.

As described above, in the wireless communication system 200 according to the first embodiment of the present disclosure, the base station 120 autonomously performs band limitation by limiting the transmission opportunity of the high priority frame 103. Furthermore, transmission opportunities are distributed according to the load data rate of each terminal 110. As a result, it is possible to avoid saturation of the channel with only the high priority frame 103. In this way, in Embodiment 1 of the present disclosure, it is possible to distribute frame transmission opportunities more fairly than in the prior art.

[Modified example]
In addition, in this embodiment, the case of the uplink in which the high priority frame 103 is mainly transmitted from the terminal 110 to the base station 120 has been described. However, the wireless communication system 200 of this embodiment is also applicable to the downlink case where the high priority frame 103 is transmitted from the base station 120 to the terminal 110.

In the case of downlink, the base station 120 determines the upper limit of the number of times the high priority frame 103 can be received by each terminal 110 under its control. The base station 120 can transmit the high priority frame 103 to the terminal 110 until the upper limit of the number of receptions is reached. Note that this point is also common to Embodiment 2 below.

Furthermore, in the case of downlink, the base station 120 itself counts the number of times the high priority frame 103 has been transmitted, so there is no need to provide the counter 130 in the terminal 110. Instead, the MAC unit 160 of the base station 120 includes a counter 130 for each of the terminals 110 under its control, in addition to the functional configuration example described in FIG.

Furthermore, in this embodiment, it will be explained with reference to FIGS. 4 and 5 that the base station 120 implements information on the upper limit of the number of transmissions of the high priority frame 103 that each terminal can transmit in the MAC frame. did. However, the upper limit information does not necessarily need to be implemented in the MAC frame, and may be implemented in other frames. Therefore, the processing of the upper limit determining section 163 is not limited to the MAC section 160. Note that this point is also common to Embodiment 2 below.

Similarly, in FIG. 7, a method has been described in which the MAC unit 260 of the terminal 110 increases the count of the counter 130 based on the transmission information of the high priority frame 103 or the CCA threshold information. However, in cases where such information is not used, the function of the counter 130 is not limited to the processing within the MAC unit 260.

Note that the processing performed by the base station 120 and the terminal 110 of the present disclosure may be executed by a program using a computer equipped with a CPU and a memory and storing a program in the memory. Alternatively, the program may be executed using an integrated circuit such as an FPGA (Field Programmable Gate Array). Note that the program may be provided recorded on a storage medium or may be provided through a network. Note that this point also applies to the processing performed by the controller 310 described in the second embodiment.

[Correspondence with terms used in claims]
The process described in this embodiment, in which the base station 120 determines the upper limit of the number of transmissions of the high-priority frame 103 that can be transmitted by each of the terminals 110 under its control, is referred to as an upper limit determination process. The upper limit value determination process is, for example, the process of step 212.

Similarly, in the case of downlink, the process by which the base station 120 determines the upper limit of the number of times the high-priority frame 103 can be received by each of the terminals 110 under its control is called the second upper limit determination process.

Further, the process described in this embodiment in which the base station 120 notifies each of the terminals 110 under its control of the upper limit value of the number of times the high priority frame 103 is transmitted is referred to as an upper limit notification process. The upper limit value notification process is, for example, the process of step 213.

Further, the process of counting the number of times the terminal 110 transmits the high priority frame 103 is called a count process.

Embodiment 2
FIG. 14 is a diagram showing the configuration of a wireless communication system according to Embodiment 2 of the present disclosure. Wireless communication system 300 includes a controller 310, a plurality of terminals 110, and a base station 120. Furthermore, a BSS 360 is configured from one base station 120 and a plurality of terminals 110 under its control. For example, in FIG. 14, three base stations 120(1), 120(2), and 120(3) each have a subordinate terminal 110, and three base stations 120(1), BSS(2), and BSS(3) Configure. However, although the case where there are three base stations will be described here, it is assumed that the number of base stations may be one or more.

The controller 310 notifies each base station 120 of the sum of the upper limit values of the counters 130 in each terminal 110 under the control of the base station (hereinafter referred to as the BSS sum value). For example, in the example of FIG. 14, the controller 310 notifies the base stations 120(1), 120(2), and 130(3) of the BSS total values A, B, and C, respectively.

The base station 120 includes a storage unit 330. The base station 120 stores information on the BSS total value given from the controller 310 in the storage unit 330. Further, based on the stored BSS total value, each subordinate terminal 110 is notified of the number of times the high priority frame 103 has been transmitted. For example, in the example of FIG. 14, base station 120(1) sets upper limit values a, b, and c for counters 130 of terminals 110(1), 110(2), and 110(3) under its control, respectively. Notice.

Note that the upper limit values a, b, and c of the counters 130 of the terminals 110(1), 110(2), and 110(3) are determined to satisfy (Formula 1) as in the first embodiment. However, here, the predetermined value A is the sum of the upper limit values of the counter 130.

In this manner, in the wireless communication system 300 of the present embodiment, the controller 310 that aggregates the base stations 120 controls the number of times the high priority frame 103 is transmitted by the terminals 110 under the control of the base stations. This makes it possible to control each BSS 360.

Note that, similarly to Embodiment 1, the BSS total value determined by the controller 310 may be set only for a single channel, or may be determined across multiple channels, links, or frequency bands.

FIG. 15 is a block diagram showing an example of the functional configuration of a controller, a base station, and a terminal according to Embodiment 2 of the present disclosure. Note that, for the sake of explanation, here, a case is described in which there is only one each as the minimum unit of the functional configuration example, but in reality, it is assumed that there are a plurality of terminals 110 within one BSS 360. It is also assumed that there may be a plurality of base stations 120 that are aggregated by the controller 310.

The controller 310 determines the BSS summation value. Furthermore, the determined information is implemented in a packet and input to the base station 120 through the upper layer 140.

Note that the BSS total value is determined according to the data rate of the terminal 110 within each BSS 360 and the communication load of the terminal 110. Thereby, the opportunity to transmit the high priority frame 103 can be more fairly distributed to each BSS 360.

Alternatively, the BSS total value can be biased so that more high-priority frames 103 can be transmitted to at least one BSS 360 according to the priority of the terminal 110 within each BSS 360.

On the other hand, in FIG. 15, information regarding the BSS total value is input from the controller 310 to the LLC unit 150 of the base station 120 via the upper layer 140.

Additionally, the MAC unit 160 stores information on the BSS total value notified from the controller 310 in the storage unit 330. Further, based on the stored BSS total value, the upper limit value of the counter 130 is determined for each of the subordinate terminals 110. Further, processing is performed to implement information on the determined upper limit value of the counter 130 into the MAC frame.

Note that the functions of the PHY transmitting section 170 and the PHY receiving section 180 of the base station 120 are the same as those in FIG. 4 of Embodiment 1, so a description thereof will be omitted.

On the other hand, the functions of the terminal 110 are also similar to those in the first embodiment. However, the value counted by the counter 130 of the MAC unit 260 at the time of transmitting the high priority frame 103 may be directly notified from the terminal 110 to the controller 310.

Note that the counting method in the counter 130 is the same as in the first embodiment, for example, the count value is incremented by 1 each time the high priority frame 103 is transmitted. Alternatively, the count number is weighted according to the communication control method performed by the terminal 110 to transmit the high-priority frame 103, that is, the control method using transmission power, CCA threshold, MCS value, number of frame retransmissions, etc. It's okay.

As described above using FIG. 15, the BSS total value is notified from the controller 310 to the base station 120. The base station 120 performs frame processing by the LLC section 150, the MAC section 160, and the PHY transmitting section 170 on the packet in which the information of the BSS total value inputted from the upper layer 140 is implemented, and generates a wireless signal. The terminal 110 that has received this wireless signal can transmit the high priority frame 103 within a range that does not exceed the upper limit value of the counter 130 assigned to itself.

FIG. 16 is a flowchart of a process for notifying a BSS total value from a controller to a base station according to Embodiment 2 of the present disclosure.

First, the controller 310 starts processing (step 340). Next, a process is performed to determine whether a certain period of time has elapsed (step 341). If it is determined that a certain period of time has elapsed, controller 310 determines a BSS summation value for each base station 120 (step 342). Furthermore, the BSS total value is notified to each base station 120 (step 343). Thereafter, the process ends (step 344).

In this way, the notification of the BSS total value by the controller 310 is performed every predetermined period of time, as in the first embodiment. Accordingly, the controller 310 calculates the fairness index based on the communication quality such as the average value calculated based on the transmission air time, RSSI, delay time, throughput, and number of frame transmissions of each transmitting terminal and each BSS 360, and calculates the fairness index. You may also perform an evaluation. This point is also similar to Embodiment 1, but the fairness index may be other than the fairness index.

Note that if the calculation result of the Fairness index or other fairness index exceeds the allowable value, the count value allocated to each terminal 110, the transmission power value, or the CCA threshold value when determining the channel state may be changed. Fairness may be controlled by This point is also similar to the first embodiment.

As explained above using the flowchart, the controller 310 notifies the base station 120 of the BSS total value every predetermined period of time. Thereby, the base station 120 can determine the upper limit value of the counter 130 in the terminal 110 under its control based on the BSS total value assigned to itself.

Note that in the above flowchart, the case where the trigger for re-notifying the BSS total value is the passage of a certain period of time has been described. However, the trigger may be the time when it is determined that the desired fairness is not achieved by calculating the Fairness index. Alternatively, the trigger may be the time when a count value is requested from the terminal 110. This point is similar to the first embodiment.

FIG. 17 is a flowchart of a process in which a base station, which has been notified of the BSS total value from the controller, notifies subordinate terminals of the upper limit value of the counter based on that information, according to Embodiment 2 of the present disclosure. be.

First, the base station 120 starts processing (step 350). Next, a process is performed to determine whether the BSS total value set by the controller has been updated (step 351). If it is determined that the update has been made, the upper limit value of the counter 130 of each terminal is determined based on the BSS total value (step 352). Furthermore, information on the determined upper limit value of the counter 130 is notified to each terminal (step 353). Thereafter, the process ends (step 354).

As explained above in the flowchart, the base station 120 determines the upper limit value of the counter 130 for each of the terminals 110 under its control based on the BSS total value notified from the controller 310, and notifies each terminal of this information. do. This allows the terminal 110 to transmit high priority frames 103 until the counter 130 reaches the upper limit.

Note that the flowchart of the process that the terminal 110 performs when transmitting the high priority frame 103 in this embodiment is the same as that in FIG. 12 of the first embodiment, so a description thereof will be omitted.

Similarly, in the wireless communication system 300 according to the present embodiment, the wireless communication sequence performed for each BSS 360 is the same as that shown in FIG. 13 of the first embodiment, so a description thereof will be omitted.

As described above, the wireless communication system 300 according to the present embodiment performs transmission opportunity control of the high priority frame 103 using the controller 310 for each BSS 360. As a result, in addition to the effects described in Embodiment 1, even if interference in wireless communication between base stations 120 becomes a problem, it is possible to avoid a decrease in transmission opportunities due to the influence of other BSSs. Can be done. That is, it can be said that it is particularly suitable for outdoor use where the usable frequency band is limited or in an OBSS (Overlapping-Basic Service Set) environment where wireless cells overlap due to the dense arrangement of base stations 120.

[Modification of Embodiment 2]

In this embodiment, the controller 310 determines the BSS summation value for each of the base stations 120 (step 342). However, instead of the BSS total value, the upper limit value of the counter 130 for each terminal 110 under the control of the base station may be directly determined.

In this way, when the controller 310 directly determines the upper limit value of the counter 130, it may directly notify each terminal 110 without going through the base station 120, as in step 343.

Note that even when the controller 310 directly determines the upper limit value of the counter 130, it is determined according to the communication load of each terminal 110, such as the load data rate of each terminal 110, as in the first embodiment. Alternatively, the upper limit value is determined to be biased so that more high priority frames 103 can be transmitted to at least one terminal.

Note that in any of the above-described determination methods, the upper limit value of the counter 130 is determined so as to satisfy (Equation 1) as in the first embodiment.

Additionally, in this embodiment, the case of uplink in which the high priority frame 103 is mainly transmitted from the terminal 110 to the base station 120 has been described. However, it is also applicable in the downlink case. In the case of downlink, the controller 310 determines the upper limit of the number of times each terminal 110 under each base station can receive the high priority frame 103, or the sum of the upper limits for each terminal for each base station. Decide and notify each base station. This allows the base station 120 to transmit high priority frames 103 to the terminals 110 under its control until this upper limit is reached.

As described above, according to the present disclosure, it is possible to provide a transmission opportunity to a terminal that transmits a low-priority frame without saturating the channel with high-priority frames in wireless communication, thereby realizing priority frame control between terminals. It becomes possible to provide a wireless communication system, a wireless terminal device, a wireless base station, a controller, and a wireless communication method that can perform the following steps.

[Correspondence with terms used in claims]
The process described in Embodiment 2 in which the controller 310 determines and notifies the BSS total value or the upper limit value of the counter 130 of each terminal 110 under the control of the base station is referred to as an upper limit value determination notification process. The upper limit value determination notification process is, for example, a series of

steps

342 and 343.

100, 200, 300 wireless communication system 103 high priority frame 104 ACK frame 105 busy state 106 low priority frame 110 wireless terminal device 120 wireless base station 130 frame counter 140

upper layer

150, 250

LLC section

160, 260

MAC section

170, 270

PHY Transmitting section

180, 280

PHY receiving section

190, 290

Antenna

161, 261

Data processing section

162, 262 MAC frame processing section 163 Upper limit determining section 171 PHY header processing section 172 Radio signal processing section 173

Encoding

174, 184 Deinterleaver 175 Modulation 176 IFFT
177, 187

OFDM modulation

178, 188 Frequency conversion 181 PHY header processing section 182 Radio signal processing section 183 Decoding 185 Demodulation 186 FFT
330 Storage section 360 BSS

Claims

A wireless communication system that gives a wireless frame transmitting/receiving opportunity preferentially to a wireless terminal device that should wirelessly communicate with a wireless base station among a plurality of wireless terminal devices according to the priority of the wireless frame,
The wireless base station that performs wireless communication with the plurality of wireless terminal devices,
Upper limit determination processing for determining, for each of the plurality of wireless terminal devices, an upper limit value of the number of times the wireless frame with the high priority can be transmitted by the wireless terminal device;
upper limit notification processing for notifying each of the plurality of wireless terminal devices of the upper limit value of the number of transmissions;
is configured to run
The plurality of wireless terminal devices transmit the high-priority wireless frames until the upper limit of the number of transmissions is reached;
a counting process for counting the number of times the high-priority wireless frame is transmitted;
A wireless communications system configured to perform.
The wireless communication system according to claim 1 further includes a controller,
The controller determines at least one of the upper limit value of the number of transmissions for each of the plurality of wireless terminal devices, or the sum of the upper limit value of the number of transmissions for each of the plurality of wireless terminal devices, and determines at least one of the upper limit value of the number of transmissions for each of the plurality of wireless terminal devices, and is configured to execute upper limit determination notification processing to notify the
In the upper limit value determination process, the wireless base station determines the upper limit value of the number of times of transmission for each of the plurality of wireless terminal devices, or the upper limit value of the number of times of transmission for each of the plurality of wireless terminal devices, which is notified from the controller. The wireless communication system according to claim 1, wherein the upper limit value of the number of transmissions is determined based on at least one of: a sum of upper limit values of the number of times.
The wireless base station is
a second upper limit value determination process of determining, for each of the plurality of wireless terminal devices, an upper limit value of the number of times the wireless frame with the high priority can be received by the wireless terminal device;
A process of transmitting the high-priority radio frame to each of the plurality of wireless terminal devices until each of the reception frequency reaches an upper limit determined in the second upper limit determination process;
The wireless communication system of claim 1, further configured to perform.
The controller includes:
For each of the plurality of wireless terminal devices, an upper limit value of the number of receptions of the high-priority radio frame that the wireless terminal device can receive, or an upper limit of the number of times the wireless frame is received by each of the plurality of wireless terminal devices. further configured to determine at least one of the total sum of upper limit values and to notify the radio base station,
The wireless base station is
Based on at least one of the upper limit value of the number of receptions for each of the plurality of wireless terminal devices, or the sum of the upper limit value of the number of receptions for each of the plurality of wireless terminal devices, notified from the controller, a process of determining an upper limit value of the number of receptions for each of the wireless terminal devices;
a process of transmitting the high-priority radio frame to each of the plurality of wireless terminal devices until an upper limit value of the number of receptions is reached for each;
3. The wireless communication system of claim 2, further configured to perform.
The wireless communication system according to claim 1, wherein the wireless base station executes the upper limit value determination process and the upper limit value notification process every predetermined period of time.
The wireless communication system according to claim 2, wherein the controller executes the upper limit value determination notification process every predetermined period of time.
The wireless communication according to claim 1, wherein the wireless base station determines the upper limit value of the number of transmissions such that the total of the upper limit value of the number of transmissions in each of the plurality of wireless terminal devices does not exceed a predetermined value. system.
When determining the upper limit value of the number of transmissions for each of the plurality of wireless terminal devices, the controller sets the upper limit value of the number of transmissions so that the total of the upper limit value of the number of transmissions does not exceed a predetermined value. The wireless communication system according to claim 2, wherein the wireless communication system determines.
At least one of the wireless base station or the controller is configured to provide a fair opportunity to transmit the high-priority wireless frame among the plurality of wireless terminal devices based on the communication load of each of the plurality of wireless terminal devices. The wireless communication system according to claim 7 or 8, wherein an upper limit value of the number of transmissions is determined.
At least one of the wireless base station or the controller further includes processing for periodically evaluating the fairness of the upper limit value of the number of transmissions in the plurality of wireless terminal devices based on the communication quality of the wireless terminal devices. 9. The wireless communication system according to 9.
At least one of the wireless base station or the controller has a higher chance of transmitting the high-priority wireless frame to at least one wireless terminal device among the plurality of wireless terminal devices according to the priority of the wireless terminal device. The wireless communication system according to claim 7 or 8, wherein the upper limit value of the number of transmissions is determined so that a large number of transmissions is given.
At least one of the wireless base station or the controller determines an upper limit value of the number of transmissions across multiple channels or multiple frequency bands,
The wireless terminal device is configured to execute a process of transmitting the high-priority wireless frame using the plurality of channels or the plurality of frequency bands until the upper limit value of the number of transmissions is reached. 3. The wireless communication system according to item 1 or 2.
2. The wireless terminal device, in the counting process, weights the number of times the high-priority wireless frame is transmitted according to a communication control method for transmitting the high-priority wireless frame. 1. The wireless communication system according to 1.
A wireless terminal device that performs wireless communication using a wireless frame having identification information indicating priority, the wireless terminal device comprising:
a process of receiving information on an upper limit value of the number of times the radio frame with a high priority can be transmitted from another radio station;
a process of transmitting the radio frame with the high priority until the upper limit is reached;
A wireless terminal device configured to perform.
A wireless base station that performs wireless communication with a plurality of wireless terminal devices using a wireless frame having identification information indicating priority, the wireless base station comprising:
Upper limit value determination processing for determining and notifying, to each of the plurality of wireless terminal devices, an upper limit value for the number of times the wireless frame with a high priority can be transmitted by the wireless terminal device;
or,
a second upper limit value determination process for determining, for each of the plurality of wireless terminal devices, an upper limit value of the number of times the wireless frame with high priority can be received by the wireless terminal device;
do at least one,
When the second upper limit value determination process is executed, for each of the plurality of wireless terminal devices, the number of reception times reaches the upper limit value determined in the second upper limit value determination process. A wireless base station further configured to perform processing for transmitting high priority wireless frames.
A controller that controls a wireless base station that performs wireless communication with a plurality of wireless terminal devices using a wireless frame having identification information indicating priority, the controller comprising:
at least an upper limit value of the number of times of transmission and reception of high-priority radio frames that each of the plurality of wireless terminal devices can transmit or receive, or a sum of the upper limit value of the number of times of transmission and reception in each of the plurality of wireless terminal devices; A controller configured to perform a process of determining one and notifying the wireless base station.
A wireless communication method that gives a wireless frame transmitting/receiving opportunity preferentially to a wireless terminal device that should wirelessly communicate with a wireless base station among a plurality of wireless terminal devices according to the priority of the wireless frame, the method comprising:
The wireless base station that performs wireless communication with the plurality of wireless terminal devices,
a process of determining, for each of the plurality of wireless terminal devices, an upper limit value for the number of times the wireless frame with a high priority can be transmitted by the wireless terminal device;
a process of notifying each of the plurality of wireless terminal devices of the upper limit value of the number of times of transmission;
Run
The plurality of wireless terminal devices transmit the high-priority wireless frames until the upper limit of the number of transmissions is reached;
a process of counting the number of times the high-priority radio frame has been transmitted;
A wireless communication method that performs.