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

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

[Technical Field]

[0001] 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 in wireless communication. [Background technology]

[0002] The number of devices connecting to the Internet wirelessly, such as smartphones, has been increasing in recent years. Furthermore, the use of applications is also increasing. As a result, the traffic quality requirements, and ultimately the traffic priorities, are becoming more diverse, ranging from text messaging to AR / VR.

[0003] The standard IEEE 802.11 is widely used in wireless LAN (Local Area Network) communications. It uses the CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) algorithm for wireless access control. CSMA / CA is a mechanism that prevents multiple terminals from transmitting frames simultaneously with other terminals by independently controlling the timing of their own frame transmissions when multiple terminals share the same frequency channel.

[0004] Non-Patent Document 1 discloses a method for 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 including information about priority in a frame, a terminal attempting to transmit a high priority frame can be given preferential access to the channel. As a result, interference control can be implemented to satisfy the required traffic quality. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] IEEE Std 802.11-2020 (Revision of IEEE Std 802.11-2016). “Part 11: Wireless LAN Medium Access Control (MAC) and Physical Layer (PHY) Specifications.” IEEE Standard for Information technology ― Telecommunications and information exchange between systems. Local and metropolitan area networks ― Specific requirements. Summary of the Invention [Problem to be solved by the invention]

[0006] However, if each terminal transmits as many high-priority frames as it likes, the channel will be saturated with high-priority frames, and there will be no opportunity to transmit low-priority frames. In addition, if the channel is saturated with high-priority frames, all frames will have the same priority, making it impossible to achieve priority control between terminals.

[0007] In order to solve the above-mentioned problems, the first objective of the present disclosure is to provide a wireless communication system that can provide transmission opportunities to terminals that transmit low-priority frames without saturating the channel with high-priority frames in wireless communication, and that can realize priority frame control between terminals.

[0008] Furthermore, a second object of the present disclosure is to provide a wireless terminal device that can provide transmission opportunities to terminals that transmit low-priority frames without saturating the channel with high-priority frames in wireless communication, thereby realizing priority frame control between terminals.

[0009] Furthermore, a third object of the present disclosure is to provide a wireless base station that can provide transmission opportunities to terminals that transmit low-priority frames without saturating the channel with high-priority frames in wireless communication, thereby realizing priority frame control between terminals.

[0010] Furthermore, a fourth object of the present disclosure is to provide a controller that can provide transmission opportunities to terminals that transmit low priority frames without saturating the channel with high priority frames in wireless communication, and that can realize priority frame control between terminals.

[0011] Furthermore, a fifth object of the present disclosure is to provide a wireless communication method 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, thereby realizing priority frame control between terminals. [Means for solving the problem]

[0012] The first aspect of the present disclosure is a method for selecting a wireless terminal device from among a plurality of wireless terminal devices that performs wireless communication with a wireless base station according to the priority of a wireless frame. A wireless communication system that gives a wireless terminal device that should receive a wireless frame a preferential opportunity to transmit and receive the wireless frame, The wireless base station that performs wireless communication with the plurality of wireless terminal devices, an 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 that the wireless terminal device can transmit the high-priority wireless frame; an upper limit notification process for notifying each of the plurality of wireless terminal devices of the upper limit value of the number of transmissions; configured to run a process in which the plurality of wireless terminal devices transmit the high-priority wireless frames until the upper limit value 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:

[0013] A second aspect is a wireless terminal device that performs wireless communication using a wireless frame having identification information indicating a priority, receiving information on an upper limit of the number of times the high-priority wireless frame can be transmitted from another wireless station; transmitting the wireless frames with the higher priority until the upper limit is reached; Preferably, the system is configured to perform the following:

[0014] 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 a priority, an upper limit value determination process for determining and notifying each of the plurality of wireless terminal devices of an upper limit value of the number of times that the wireless terminal device can transmit a high-priority wireless frame; 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 that the wireless terminal device can receive a high-priority wireless frame; Do at least one of the following: When the second upper limit value determination process is executed, it is preferable that the system is configured to further execute a process of transmitting the high priority wireless frame to each of the plurality of wireless terminal devices until the upper limit value of the number of receptions for each of the devices determined in the second upper limit value determination process is reached.

[0015] 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 a priority, determining at least one of an upper limit value of the number of times of transmission and reception of high-priority wireless frames that can be transmitted or received by each of the plurality of wireless terminal devices or a sum of the upper limit values ​​of the number of times of transmission and reception in each of the plurality of wireless terminal devices, and notifying the wireless base station of the upper limit value; Preferably, the device is configured to perform the process.

[0016] A fifth aspect is a wireless communication method for preferentially providing a wireless terminal device that should perform wireless communication with a wireless base station, among a plurality of wireless terminal devices, with an opportunity to transmit and receive a wireless frame in accordance with a priority of the wireless frame, the method comprising: The wireless base station that performs wireless communication with the plurality of wireless terminal devices, determining, for each of the plurality of wireless terminal devices, an upper limit value of the number of times that the wireless terminal device can transmit a high-priority wireless frame; a process of notifying each of the plurality of wireless terminal devices of the upper limit value of the number of transmissions; Run a process in which the plurality of wireless terminal devices transmit the high-priority wireless frames until the upper limit value of the number of transmissions is reached; counting the number of times the high-priority wireless frame has been transmitted; It is preferable to perform the following. [Effects of the Invention]

[0017] According to the first to fifth aspects of the present disclosure, it is possible to provide a wireless communication system, a wireless terminal device, a wireless base station, a controller, and a wireless communication method that can provide transmission opportunities to terminals that transmit low priority frames without saturating a channel with high priority frames in wireless communication, thereby realizing priority frame control between terminals. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram illustrating an example of the configuration of a conventional wireless communication system according to a comparative example. [Figure 2] 10 is an example of a wireless communication sequence in a conventional wireless communication system according to a comparative example. [Figure 3] 1 is a diagram illustrating a configuration of a wireless communication system according to a first embodiment of the present disclosure. [Figure 4] FIG. 2 is a block diagram illustrating an example of the functional configuration of a terminal and a base station. [Figure 5]10 is a block diagram showing an example of a detailed functional configuration of a MAC unit of a base station when transmitting a radio signal. FIG. [Figure 6] 10 is a block diagram showing an example of a detailed functional configuration of a MAC unit of a base station when receiving a radio signal. FIG. [Figure 7] 10 is a block diagram showing an example of a detailed functional configuration of a MAC unit of a terminal when transmitting a wireless signal. FIG. [Figure 8] 10 is a block diagram showing an example of a detailed functional configuration of a MAC unit of a terminal when receiving a wireless signal. FIG. [Figure 9] FIG. 2 is a block diagram illustrating a detailed example of the functional configuration of a PHY transmission unit of the base station. [Figure 10] FIG. 2 is a block diagram illustrating a detailed example of the functional configuration of a PHY receiving unit of the base station. [Figure 11] 10 is a flowchart of a process in which a base station notifies a subordinate terminal of an upper limit value of a counter according to the first embodiment of the present disclosure. [Figure 12] 4 is a flowchart of a process performed by a terminal when transmitting a high-priority frame according to the first embodiment of the present disclosure. [Figure 13] 3 is an example of a wireless communication sequence in a wireless communication system according to the first embodiment of the present disclosure. [Figure 14] FIG. 10 is a diagram illustrating a configuration of a wireless communication system according to a second embodiment of the present disclosure. [Figure 15] FIG. 11 is a block diagram illustrating an example of functional configurations of a controller, a base station, and a terminal according to a second embodiment of the present disclosure. [Figure 16] 11 is a flowchart of a process in which a controller notifies a base station of a BSS sum value according to a second embodiment of the present disclosure. [Figure 17] 11 is a flowchart of a process in which a base station notifies a subordinate terminal of an upper limit value of a counter based on the information, the base station having received a BSS total value from a controller, according to a second embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0019] Comparative Example Here, we will first explain the conventional technology as a comparative example. Figure 1 is a diagram showing an example of the configuration of a conventional wireless communication system according to the comparative example. The conventional wireless communication system 100 includes multiple wireless terminal devices (hereinafter referred to as terminals) 110(1), 110(2), and 110(3).

[0020] The terminal 110 performs wireless communication with the wireless base station 120 based on the IEEE 802.11 standard. The terminal 110 may be a general-purpose terminal such as a smartphone, or may be a terminal installed in a factory or the like and used for a dedicated purpose such as monitoring and controlling machinery.

[0021] The wireless base station (hereinafter referred to as the base station) 120 is a wireless base station that 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. When the applied wireless communication system is Wi-Fi (registered trademark), the base station 120 corresponds to an access point.

[0022] FIG. 2 is an example of a wireless communication sequence in a conventional wireless communication system according to a comparative example.

[0023] A plurality of terminals 110(1), 110(2), 110(3) and the base station 120 each access a channel and transmit data based on the CSMA / CA algorithm.

[0024] Priorities are assigned to wireless frames transmitted by terminal 110. In the example of Fig. 2, terminal 110(1) first transmits high-priority frame 103(1) to base station 120. Upon receiving high-priority frame 103(1), base station 120 returns ACK frame 104(1) to terminal 110(1) as proof that the data has been received successfully.

[0025] When the other terminals 110(2) and 110(3) detect that a terminal other than themselves is performing data communication, they set themselves to busy state 105 and wait until the current communication is completed.

[0026] When terminal 110(1) finishes its data communication, terminal 110(2) then transmits high-priority frame 103(2). Base station 120 returns ACK frame 104(2) to terminal 110(2). Meanwhile, the other terminals 110(1) and 110(3) are in busy state 105.

[0027] In this way, in the prior art, terminal 110 that transmitted high priority frame 103 has priority to access the channel and transmits data to base station 120. However, because high priority frames are transmitted from each terminal without any restrictions, terminals that attempt to transmit non-high priority frames, such as terminal 110(3), remain in busy state 105 and are unable to transmit their own data.

[0028] As described 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.

[0029] 2 illustrates an uplink case in which data is transmitted from the terminal 110 to the base station 120. However, data may be transmitted from the base station 120 to the terminal 110, i.e., a downlink case.

[0030] Embodiment 1 3 is a diagram illustrating a configuration of a wireless communication system according to the first embodiment of the present disclosure. Similar to the comparative example, wireless communication system 200 includes multiple terminals 110 and a base station 120. Unlike the comparative example, wireless communication system 200 of this embodiment includes frame counters 130(1), 130(2), and 130(3) set in each terminal 110.

[0031] Frame counter (hereinafter referred to as counter) 130 is a part that performs processing related to the number of times a high priority frame is transmitted by terminal 110. Each terminal 110 transmits high priority frames 103 until the count value of counter 130 reaches the upper limit. The upper limit value is set by base station 120 for 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.

[0032] The upper limit values ​​a, b, and c of the counter 130 are set so that their sum (a+b+c) does not exceed a predetermined value A. That is, they are set so as to satisfy the following conditional expression. a+b+c≦A (Formula 1)

[0033] In this way, in the wireless communication system 200 of this embodiment, the number of times that each terminal 110 can transmit the high priority frame 103 is limited.

[0034] The upper limit value of the counter 130 may be set for only a single channel, or may be set across multiple channels, links, or frequency bands. By setting the upper limit value across multiple channels or links, the count value can be increased fairly even when the number of times the high-priority frame 103 is transmitted is insufficient over a single link and multiple channels or frequency bands are used for transmission.

[0035] 4 is a block diagram showing an example of the functional configuration of a terminal and a base station. For the sake of explanation, it is assumed that there is one terminal 110, but in reality there are multiple terminals.

[0036] Here, we will first explain the function of the base station 120 when transmitting a radio signal. 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, the application layer.

[0037] For packets input from the upper layer 140, the base station 120 performs frame processing such as adding or deleting information to frames of the physical layer and data link layer based on the IEEE802.11 frame format. The data link layer further includes an LLC (Logical Link Control) sublayer and a MAC (Media Access Control) sublayer, and the base station 120 performs processing for each of these sublayers.

[0038] LLC unit 150 is an interface with upper layer 140, and performs LLC layer processing on packets input from upper layer 140. Specifically, it adds a header such as a DSAP (Destination Service Access Point) or an SSAP (Source Service Access Point) to the packet and inputs it to MAC unit 160.

[0039] The MAC unit 160 performs MAC layer processing and adds a MAC header to the packet input from the LLC unit 150, the MAC unit 160 including a destination address, a source address, a sequence number, a traffic type (Traffic Identifier, TID) indicating the priority of the data, an error detection code, etc.

[0040] Furthermore, when the upper limit value of the counter 130 is notified to the terminal 110, the upper limit value determination unit 163 included in the MAC unit 160 performs processing to implement information about the upper limit value in the MAC frame of the packet.

[0041] Furthermore, the MAC unit 160 determines whether or not frame transmission is possible by performing carrier sensing based on the CSMA / CA algorithm, based on the received power input from the PHY receiving unit 180. If transmission is possible, the MAC unit 160 outputs the data input to the MAC frame to the PHY transmitting unit 170.

[0042] The PHY transmitter 170 is a section that performs PHY layer processing. When a frame is input from the MAC section 160, it generates a radio signal by adding a PHY header, a preamble, etc. to the frame. The preamble includes a BSS (Basic Service Set) color, which is identification information for the destination base station 120, and a QoS color, which is identification information for the frame priority.

[0043] The radio signal generated in the PHY transmitter 170 is transmitted from the antenna 190 to the terminal 110 .

[0044] In this way, the base station 120 performs frame processing on the data input from the upper layer 140 using the LLC unit 150 , MAC unit 160 , and PHY transmission unit 170 , and generates a radio signal for the terminal 110 .

[0045] Next, when receiving a radio signal, the base station 120 receives the radio signal via its own antenna 190. The PHY receiving unit 180 demodulates the PHY header, preamble, and the like from the received radio signal.

[0046] When a packet is input from the PHY receiving unit 180, the MAC unit 160 demodulates the MAC header, and if the data is addressed to the MAC unit 160, inputs the data to the LLC unit 150, and so on.

[0047] When a packet is input from the MAC unit 160, the LLC unit 150 deletes the header as described above and then inputs the packet to the upper layer 140.

[0048] In this way, when base station 120 receives a radio signal addressed to itself, it performs frame processing using PHY receiving unit 180 , MAC unit 160 , and LLC unit 150 , and inputs the extracted data to upper layer 140 .

[0049] On the other hand, like base station 120, terminal 110 includes LLC unit 250, MAC unit 260, PHY transmitter unit 270, PHY receiver unit 280, and antenna 290. Note that the functions of LLC unit 250, PHY transmitter unit 270, PHY receiver unit 280, and antenna 290 are the same as those in base station 120 described above, and therefore description thereof will be omitted.

[0050] On the other hand, when transmitting a 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.

[0051] 4, the base station 120 implements information on the upper limit of the number of times each terminal can transmit the high priority frame 103 in a MAC frame and notifies each terminal 110. Furthermore, when the terminal 110 transmits the high priority frame 103 to the base station 120, a process of incrementing the count is performed in the counter 130 in the MAC unit 260 of the terminal.

[0052] 4, for the sake of explanation, the processing functions in the PHY layer are divided into those for transmission and those for reception, and are shown as PHY transmitter 170 and PHY receiver 180. However, these functions are actually performed by a single PHY layer processor. Note that base station 120 and terminal 110 do not have multiple PHY layer processors with different functions.

[0053] FIG. 5 is a block diagram showing an example of a detailed functional configuration of the MAC unit of the base station when transmitting a radio signal.

[0054] After receiving a packet from the LLC unit 150, the data processing unit 161 assigns a MAC header to the packet, which contains information such as a destination address or a TID indicating the priority of the data, and then outputs the data with the MAC header to the MAC frame processing unit 162.

[0055] The MAC frame processing unit 162 performs carrier sensing for a random period of time based on the CSMA / CA algorithm, and receives notification of the channel state, such as the received power, received by the PHY receiving unit 180. If the channel is determined to be in an idle state by comparison with the CCA threshold, the MAC frame processing unit 162 outputs the data input from the data processing unit 161 to the PHY transmitting unit 170.

[0056] In addition, in order to address the exposed terminal problem and ensure low latency for high priority frames 103, the CCA threshold may be determined according to the combination of the BSS color and QoS color values ​​contained in the frame of the wireless signal received during carrier sensing.

[0057] The upper limit determination unit 163 determines the upper limit of the counter 130 for each of the subordinate terminals 110, and implements this information in the MAC frame.

[0058] 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. This allows the opportunity to transmit high priority frames 103 to each terminal 110 more fairly.

[0059] 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 counter 130 can be determined depending on fluctuations in the number of subordinate terminals 110, fluctuations in the communication environment, and increases and decreases in communication resources.

[0060] In any of the above-mentioned determination methods, the upper limit value of the counter 130 is determined so as to satisfy the above (Equation 1).

[0061] As described above, the base station 120 determines the upper limit value of the counter 130 for each terminal 110 in the upper limit value determination unit 163 in the MAC unit 160. This makes it possible to control the fairness of the number of times the high priority frame 103 is transmitted.

[0062] FIG. 6 is a block diagram showing an example of a detailed functional configuration of the MAC unit of the base station when receiving a radio signal.

[0063] First, a frame addressed to the own BSS is detected in PHY receiving section 180, and a MAC frame is input from PHY receiving section 180. Then, MAC frame processing section 162 demodulates the MAC header. Furthermore, the demodulated data is output to data processing section 161.

[0064] The data processing unit 161 references the MAC header of the input data, extracts the data, and inputs it to the LLC unit 150 .

[0065] 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 base station itself.

[0066] 7 is a block diagram showing a detailed example of the functional configuration of the MAC unit of the terminal when transmitting a wireless signal. As in the case of base station 120, MAC unit 260 includes data processing unit 261 and MAC frame processing unit 262. These functions when transmitting a wireless signal are the same as in the case of base station 120, so a description thereof will be omitted.

[0067] On the other hand, unlike the base station 120, the MAC unit 260 of the terminal 110 includes a counter 130.

[0068] 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 to determine the channel state.

[0069] Regarding the counting method in the counter 130, for example, the count value is incremented by 1 each time a 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. The communication control method is a transmission control method for the high priority frame 103 that uses transmission power, a CCA threshold, an MCS (Modulation and Coding Scheme) value, the number of frame retransmissions, etc.

[0070] For example, if terminal 110 transmits high priority frame 103 by increasing the transmission power value, it will be more likely to be received by base station 120 than other terminals, so the value counted at one time will be larger than when transmitting without increasing the transmission power.

[0071] In addition, when transmitting with the CCA threshold raised, it becomes easier to determine that the channel is idle, and since a transmission opportunity is obtained, the value counted at one time is larger than when transmitting without raising the CCA threshold.

[0072] Similarly, when a frame is sent with a lowered MSC value, the transmission time is lengthened, the time the channel is occupied is lengthened, and transmission opportunities for other terminals 110 are reduced, so the value counted at one time is made larger than when the frame is sent without lowering the MCS value. 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.

[0073] In this way, by weighting the count depending on the communication control method implemented by the terminal 110 to transmit the high priority frame 103, it is possible to perform more fair transmission opportunity control among the terminals 110.

[0074] 8 is a block diagram showing a detailed example of the functional configuration of the MAC unit of the terminal when receiving a wireless signal. As in the case of base station 120, MAC unit 260 includes data processing unit 261 and MAC frame processing unit 262. These functions when receiving a wireless signal are the same as in the case of base station 120, so a description thereof will be omitted.

[0075] FIG. 9 is a block diagram showing a detailed example of the functional configuration of the PHY transmission unit of the base station.

[0076] First, carrier sensing is performed in the MAC unit 160 , and when the right to transmit a frame is acquired as a result of determining that the channel is in an idle state, a MAC frame is input from the MAC unit 160 to the PHY transmission unit 170 .

[0077] The PHY header processing unit 171 receives a MAC frame from the MAC unit 160. The PHY header processing unit 171 generates a frame by adding a PHY header, a preamble, etc., including information such as a BSS color and a QoS color, to the MAC frame. Here, the QoS color may be added based on the TID information in the MAC header, etc.

[0078] The radio signal processing unit 172 converts the frame input from the PHY header processing unit 171 into a radio signal. There, signal processing such as encoding 173, deinterleaver 174, modulation 175, inverse fast Fourier transform (IFFT) 176, orthogonal frequency division multiplexing (OFDM) modulation 177, and frequency conversion 178 is performed in this order. Thereafter, the converted radio signal is transmitted as a radio frame from an antenna 190.

[0079] In this way, the PHY transmission unit 170 of the base station 120 can add further information to the frame input from the upper layer, convert it into a radio signal, and transmit it to the terminal 110.

[0080] The functional configuration example of the PHY transmission unit 270 of the terminal 110 is also common to that of the base station 120 in FIG. 9, and therefore description thereof will be omitted.

[0081] 10 is a block diagram showing a detailed example of the functional configuration of the PHY receiver of the base station. Note that the functions described here are performed not only when receiving a frame, but also when performing carrier sensing before transmitting a frame.

[0082] First, the radio signal processing unit 182 decodes the radio signal received by the antenna 190. Here, signal processing is performed in the reverse order to that performed during 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 this order. Thereafter, the obtained frame is output to the PHY header processing unit 181.

[0083] The PHY header processing unit 181 receives a wireless frame from the wireless signal processing unit 182 and identifies information such as the BSS color and QoS color contained in the preamble of the wireless frame. The BSS color and QoS color information identified by the PHY header processing unit 181 may be input to the MAC unit 160 together with the payload without being deleted.

[0084] In this way, the PHY receiver 180 of the base station 120 can decode the radio signal transmitted from another radio base station and extract the information contained in the frame.

[0085] The functional configuration example of the PHY receiver 280 of the terminal 110 is also common to that of the base station 120, and therefore description thereof will be omitted.

[0086] FIG. 11 is a flowchart of a process in which a base station notifies a subordinate terminal of an upper limit value of a counter according to the first embodiment of the present disclosure.

[0087] First, base station 120 starts processing (step 210). Next, it performs processing to determine whether a certain time has elapsed (step 211). If it is determined that the certain time has elapsed, base station 120 determines the upper limit value of counter 130 for each of subordinate terminals 110 (step 212). Information on the determined upper limit value of counter 130 is notified to each terminal (step 213). Thereafter, processing ends (step 214).

[0088] As explained above with reference to the flowchart, the base station 120 notifies the terminal 110 under its control of the upper limit value of the counter 130 at regular intervals.

[0089] Here, along with notification of the upper limit value of counter 130, MAC section 160 of base station 120 may periodically evaluate the fairness of the upper limit values ​​among terminals 110 under its control using a fairness index.

[0090] The fairness index is calculated based on the communication quality of wireless communication in each terminal 110. The communication quality may be, for example, the count number of the counter 130 assigned to each terminal 110, transmission airtime, throughput, delay time, PER (Packet Error Rate), MCS value, number of retransmitted packets, RSSI (Received Signal Strength Indicator), SINR (Signal-to-Interference plus Noise power Ratio), etc.

[0091] For example, when the transmission airtime or throughput value is used as the criterion, it is evaluated whether communication opportunities are provided to each terminal 110 so that these are equal.

[0092] Alternatively, when RSSI is used as a criterion, it is evaluated whether there is any bias in the degree of control of transmission power.

[0093] In this way, the fairness index is calculated periodically in the MAC unit 160 of the base station 120. 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.

[0094] 11, the trigger for re-notifying the upper limit is explained as the passage of a certain period of time. However, for example, the trigger may be the time when it is determined that the desired fairness is not being achieved, using a fairness index.

[0095] Furthermore, as another example of the trigger in FIG. 11, when the upper limit value of allocation is small compared to the number of high priority frames that the terminal 110 should transmit, a request for a count value made by the terminal 110 to the base station may be used as the trigger.

[0096] 12 is a flowchart of a process performed by a terminal when transmitting a high-priority frame according to the first embodiment of the present disclosure. First, the terminal 110 starts the process (step 220). Next, the terminal 110 receives traffic from the upper layer 140 (step 221). Next, it determines whether the traffic has a high priority (step 222). If it is not determined that the priority is high, it attempts to transmit the frame as a low-priority frame 106 (step 223).

[0097] On the other hand, if it is determined in step 222 that the priority is high, the counter 130 is referenced to determine whether the current count value is less than the upper limit (step 224). If it is not less than the upper limit, this means that the count value has already reached the upper limit. Therefore, an attempt is made to transmit the frame as a low-priority frame 106 (step 223). On the other hand, if the count value is less than the upper limit, the counter 130 is incremented by one, and an attempt is made to transmit the frame as a high-priority frame 103 (step 225). Finally, the process ends (step 226).

[0098] In this way, the terminal 110 can transmit high-priority frames 103 within a certain period of time until the counter 130 reaches its upper limit. After the counter 130 reaches its upper limit, the terminal 110 transmits frames as normal low-priority frames 106, not as high-priority frames 103.

[0099] In step 225, the count is incremented 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.

[0100] It should be noted that even if the high priority frame 103 is transmitted in step 225, it may fail later. In step 225, a method of incrementing the count value of the counter 130 is shown, including in the case of failure, but if the transmission of the high priority frame 103 fails, the count value does not need to be incremented.

[0101] FIG. 13 illustrates an example of a wireless communication sequence in a wireless communication system according to the first embodiment of the present disclosure.

[0102] The counters 130 of the terminals 110(1), 110(2), and 110(3) are set with upper limit values ​​a, b, and c per certain time period, respectively.

[0103] First, 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.

[0104] Next, after the communication of terminal 110(1), terminal 110(2) also transmits high priority frame 103(2). Similarly, it is assumed that counter 130(2) of terminal 110(2) also reaches upper limit value b.

[0105] In this case, terminal 110(1) and terminal 110(2) cannot transmit any more high-priority frames 103 until a certain time has passed. Then, terminal 110(3), which had been in a busy state 105 until then, is given an opportunity to transmit low-priority frame 106.

[0106] In this way, in the wireless communication sequence carried out in the wireless communication system 200 according to this embodiment, a transmission opportunity is also given to the terminal 110 that transmits the low priority frame 106.

[0107] As described above, in wireless communication system 200 according to the first embodiment of the present disclosure, base station 120 autonomously limits bandwidth by limiting transmission opportunities for high-priority frames 103. Also, transmission opportunities are distributed according to the load data rate of each terminal 110. As a result, it is possible to prevent the channel from being saturated with only high-priority frames 103. In this way, according to the first embodiment of the present disclosure, frame transmission opportunities can be distributed more fairly than in conventional techniques.

[0108] [Variations] In this embodiment, the case of uplink in which high priority frame 103 is transmitted from terminal 110 to base station 120 has been mainly described. However, wireless communication system 200 of this embodiment can also be applied to the case of downlink in which high priority frame 103 is transmitted from base station 120 to terminal 110.

[0109] In the case of downlink, the base station 120 determines an upper limit on the number of times that each of the subordinate terminals 110 can receive the high priority frame 103. The base station 120 can transmit the high priority frame 103 to the terminal 110 until the upper limit on the number of times that the high priority frame 103 can be received is reached. This point is also common to the following embodiment 2.

[0110] In the case of downlink, the base station 120 itself counts the number of times it has transmitted the high priority frame 103, so there is no need to provide the terminal 110 with the counter 130. 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 example functional configuration described in FIG.

[0111] 4 and 5, in this embodiment, the base station 120 implements information on the upper limit of the number of times each terminal can transmit a high priority frame 103 in a MAC frame. However, the information on the upper limit does not necessarily have to be implemented in the MAC frame, and may be implemented in another frame. Therefore, the processing of the upper limit determination unit 163 is not limited to within the MAC unit 160. This point is also common to the following second embodiment.

[0112] 7, a method has been described in which the MAC unit 260 of the terminal 110 increments 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 this information is not used, the function of the counter 130 is not limited to the processing within the MAC unit 260.

[0113] 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 having a CPU and memory and storing a program 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 may be provided via a network. This also applies to the processing performed by the controller 310 described in the second embodiment.

[0114] [Correspondence to terms used in claims] The process of determining the upper limit of the number of times that each of the terminals 110 under the base station 120 can transmit the high-priority frame 103, as described in this embodiment, is called upper limit determination process. The upper limit determination process is, for example, the process of step 212.

[0115] Similarly, in the case of downlink, the process by the base station 120 to determine the upper limit of the number of times that each of the terminals 110 under its control can receive the high priority frame 103 is called second upper limit determination process.

[0116] Furthermore, the process described in this embodiment in which the base station 120 notifies each of the subordinate terminals 110 of the upper limit of the number of times the high priority frame 103 can be transmitted is called upper limit notification process. The upper limit notification process is, for example, the process of step 213.

[0117] Furthermore, the process of counting the number of times the terminal 110 has transmitted the high priority frame 103 is called counting process.

[0118] Embodiment 2 FIG. 14 is a diagram illustrating a configuration of a wireless communication system according to a second embodiment of the present disclosure. The wireless communication system 300 includes a controller 310, multiple terminals 110, and a base station 120. Furthermore, a BSS 360 is configured from one base station 120 and multiple terminals 110 subordinate to it. For example, in FIG. 14, three base stations 120(1), 120(2), and 120(3) each include a terminal 110 subordinate to them, forming three BSSs: BSS(1), BSS(2), and BSS(3). Note that although a case where there are three base stations will be described here, the number of base stations may be one or more.

[0119] 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 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 sum values ​​A, B, and C, respectively.

[0120] The base station 120 includes a storage unit 330. The base station 120 stores information about the BSS sum value provided by the controller 310 in the storage unit 330. Furthermore, based on the stored BSS sum value, the base station 120 notifies each of the subordinate terminals 110 of the number of times the high priority frame 103 has been transmitted. For example, in the example of FIG. 14, the base station 120(1) notifies the counters 130 of the subordinate terminals 110(1), 110(2), and 110(3) of upper limit values ​​a, b, and c, respectively.

[0121] 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 (Equation 1), as in the first embodiment. However, in this case, the predetermined value A is the sum of the upper limit values ​​of the counters 130.

[0122] In this way, in the wireless communication system 300 of this embodiment, the controller 310 that aggregates the base stations 120 controls the number of times that the terminals 110 under the control of the base station transmit the high priority frame 103. This makes it possible to control each BSS 360 individually.

[0123] As in the first embodiment, the BSS sum value determined by the controller 310 may be set for only a single channel, or may be determined across multiple channels, links, or frequency bands.

[0124] 15 is a block diagram showing an example of a functional configuration of a controller, a base station, and a terminal according to the second embodiment of the present disclosure. Note that for the sake of explanation, a case where there is only one of each as the minimum unit of the functional configuration example is described here, but in reality, there are multiple terminals 110 in one BSS 360. Also, there may be multiple base stations 120 aggregated by the controller 310.

[0125] The controller 310 determines the BSS sum value, and then packages the determined information into a packet and inputs it to the base station 120 through the upper layer 140.

[0126] The BSS sum value is determined according to the communication load of the terminals 110, such as the data rate of the terminals 110 in each BSS 360. This allows the opportunities to transmit high-priority frames 103 to be distributed more fairly to each BSS 360.

[0127] Alternatively, the BSS sum value may be biased so that more high-priority frames 103 can be transmitted to at least one BSS 360 depending on the priority of the terminal 110 within each BSS 360 .

[0128] Meanwhile, in FIG. 15, information relating to the BSS sum value is input from controller 310 to LLC unit 150 of base station 120 via upper layer 140.

[0129] The MAC unit 160 also stores the information on the BSS total value notified by the controller 310 in the storage unit 330. Furthermore, based on the stored BSS total value, it determines the upper limit value of the counter 130 for each of the subordinate terminals 110. It also performs processing to implement the determined information on the upper limit value of the counter 130 in the MAC frame.

[0130] The functions of the PHY transmitter 170 and the PHY receiver 180 of the base station 120 are the same as those in FIG. 4 of the first embodiment, and therefore a description thereof will be omitted.

[0131] Meanwhile, the functions of the terminal 110 are the same as those of embodiment 1. However, the terminal 110 may directly notify the controller 310 of the count value of the counter 130 of the MAC unit 260 when the high priority frame 103 is transmitted.

[0132] As for the counting method in counter 130, as in the first embodiment, for example, the count value is incremented by 1 each time high priority frame 103 is transmitted. Alternatively, the count value may be weighted according to the communication control method implemented by terminal 110 to transmit high priority frame 103, that is, a control method using transmission power, a CCA threshold, an MCS value, the number of frame retransmissions, etc.

[0133] 15, the BSS sum value is notified from controller 310 to base station 120. Base station 120 performs frame processing on the packet containing the BSS sum value information input from upper layer 140 using LLC unit 150, MAC unit 160, and PHY transmitter unit 170 to generate a radio signal. Terminal 110 that receives this radio signal can transmit high priority frame 103 based on the upper limit value of counter 130 assigned to itself, provided that this limit is not exceeded.

[0134] FIG. 16 is a flowchart of a process in which a controller notifies a base station of a BSS sum value according to the second embodiment of the present disclosure.

[0135] First, the controller 310 starts processing (step 340). Next, a process is performed to determine whether a certain time has elapsed (step 341). If it is determined that the certain time has elapsed, the controller 310 determines a BSS sum value for each base station 120 (step 342). Furthermore, the controller 310 notifies each base station 120 of the BSS sum value (step 343). Thereafter, the process ends (step 344).

[0136] In this way, the notification of the BSS sum value by the controller 310 is performed at regular time intervals, as in the first embodiment. Accordingly, the controller 310 may calculate a fairness index and evaluate fairness based on communication quality such as an average value calculated based on the transmission airtime, RSSI, delay time, throughput, and number of frame transmissions of each transmitting terminal and each BSS 360. This is also the same as in the first embodiment, but the fairness index may be something other than the fairness index.

[0137] If the calculation result of the fairness index or other fairness index exceeds the allowable value, fairness may be controlled by changing the count value, transmission power value, or CCA threshold value used to determine the channel state allocated to each terminal 110. This point is also the same as in the first embodiment.

[0138] As explained above with reference to the flowchart, the controller 310 notifies the base station 120 of the BSS sum value at regular intervals. This allows the base station 120 to determine the upper limit of the counter 130 in the terminal 110 under its control based on the BSS sum value assigned to itself.

[0139] In the above flowchart, the case where the trigger for re-notifying the BSS sum value is the passage of a certain period of time has been described. However, the trigger may also be the point in time when it is determined that the desired fairness has not been achieved by calculating the fairness index. Alternatively, the trigger may also be the point in time when a count value request is received from terminal 110. This point is the same as in the first embodiment.

[0140] FIG. 17 is a flowchart of a process in which a base station notifies a subordinate terminal of an upper limit value of a counter based on the information, the base station having received a BSS total value from a controller, according to the second embodiment of the present disclosure.

[0141] First, base station 120 starts processing (step 350). Next, it performs processing to determine whether the BSS sum value set by the controller has been updated (step 351). If it is determined that the BSS sum value has been updated, it determines the upper limit value of counter 130 for each terminal based on the BSS sum value (step 352). Furthermore, it notifies each terminal of the determined upper limit value of counter 130 (step 353). Then, it terminates processing (step 354).

[0142] As explained above with reference to the flowchart, the base station 120 determines the upper limit value of the counter 130 for each of the subordinate terminals 110 based on the BSS sum value notified by the controller 310, and notifies each terminal of this information. This allows the terminals 110 to transmit high-priority frames 103 until the counter 130 reaches the upper limit.

[0143] In this embodiment, the flowchart of the process performed by the terminal 110 when transmitting the high priority frame 103 is the same as that shown in FIG. 12 in the first embodiment, and therefore a description thereof will be omitted.

[0144] Similarly, in the wireless communication system 300 according to this embodiment, the wireless communication sequence performed for each BSS 360 is the same as that shown in FIG. 13 of the first embodiment, and therefore a description thereof will be omitted.

[0145] As described above, the wireless communication system 300 according to this embodiment uses the controller 310 to control transmission opportunities for the high priority frame 103 for each BSS 360. This not only achieves the effects described in the first embodiment, but also makes it possible to avoid a decrease in transmission opportunities due to the influence of other BSSs even in cases where interference in wireless communications between the base stations 120 becomes a problem. In other words, this is particularly suitable for outdoor use where there are restrictions on the frequency bands available, or in an OBSS (Overlapping-Basic Service Set) environment where wireless cells overlap due to a dense arrangement of the base stations 120.

[0146] [Modification of the second embodiment]

[0147] In this embodiment, the controller 310 determines the BSS sum value for each of the base stations 120 (step 342). However, instead of the BSS sum value, the upper limit value of the counter 130 for each of the terminals 110 under the control of the base station may be determined directly.

[0148] In this way, when the controller 310 directly determines the upper limit value of the counter 130, as in step 343, the controller 310 may notify each terminal 110 directly without going through the base station 120.

[0149] Note that, even when the controller 310 directly determines the upper limit value of the counter 130, the determination is made in accordance with 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.

[0150] In any of the above-mentioned determination methods, the upper limit value of the counter 130 is determined so as to satisfy (Equation 1), as in the first embodiment.

[0151] Furthermore, in this embodiment, the case of uplink, in which high priority frames 103 are transmitted from terminal 110 to base station 120, has been mainly described. However, the present invention can also be applied to downlink. In the case of downlink, controller 310 determines the upper limit of the number of times high priority frames 103 can be received by each terminal 110 under the control of each base station, or the sum of the upper limit values ​​for each terminal for each base station, and notifies each base station. This allows base station 120 to transmit high priority frames 103 to terminals 110 under its control until this upper limit is reached.

[0152] As described above, according to the present disclosure, it is possible to provide a wireless communication system, a wireless terminal device, a wireless base station, a controller, and a wireless communication method that can provide transmission opportunities to terminals that transmit low priority frames without saturating the channel with high priority frames in wireless communication, and can realize priority frame control between terminals.

[0153] [Correspondence to terms used in claims] The process in which controller 310 determines and notifies the BSS total value or the upper limit value of counter 130 of each terminal 110 under the control of the base station, as explained in the second embodiment, is called upper limit determination and notification process. The upper limit determination and notification process is a series of processes, for example, steps 342 and 343. [Explanation of symbols]

[0154] 100, 200, 300 wireless communication systems 103 High Priority Frames 104 ACK Frame 105 Busy 106 Low Priority Frames 110 Wireless terminal equipment 120 wireless base stations 130 Frame Counter 140 Upper Tier 150, 250 LLC Department 160, 260 MAC section 170, 270 PHY transmitter 180, 280 PHY receiver 190, 290 antenna 161, 261 Data processing section 162, 262 MAC frame processing section 163 Upper limit value determination unit 171 PHY header processing unit 172 Radio signal processing unit 173 Encoding 174, 184 Deinterleaver 175 Modulation 176 IFFT 177, 187 OFDM modulation 178, 188 Frequency conversion 181 PHY header processing unit 182 Radio signal processing unit 183 Decryption 185 Recovery 186 FFT 330 Storage Unit 360 BSS

Claims

1. According to the priority of the wireless frame, one of the multiple wireless terminal devices is selected to perform wireless communication with the wireless base station. A wireless communication system that gives a wireless terminal device that should receive a wireless frame a preferential opportunity to transmit and receive the wireless frame, The wireless base station that performs wireless communication with the plurality of wireless terminal devices, an 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 that the wireless terminal device can transmit the high-priority wireless frame; an upper limit notification process for notifying each of the plurality of wireless terminal devices of the upper limit value of the number of transmissions; configured to run a process in which the plurality of wireless terminal devices transmit the high-priority wireless frames until the upper limit value of the number of transmissions is reached; a counting process for counting the number of times the high-priority wireless frame is transmitted; 1. A wireless communication system configured to perform the steps of:

2. The wireless communication system of claim 1 further comprises a controller: the controller is configured to execute an upper limit value determination and notification process to determine at least one of an upper limit value of the number of transmissions for each of the plurality of wireless terminal devices and a sum of the upper limit values ​​of the number of transmissions for each of the plurality of wireless terminal devices, and notify the wireless base station of the upper limit value determination and notification; 2. The wireless communication system according to claim 1, wherein, in the upper limit value determination process, the wireless base station determines the upper limit value of the number of transmissions based on at least one of the upper limit value of the number of transmissions for each of the plurality of wireless terminal devices notified by the controller or the sum of the upper limit values ​​of the number of transmissions for each of the plurality of wireless terminal devices.

3. The radio base station 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 high-priority wireless frame can be received by the wireless terminal device; a process of transmitting the high-priority wireless frame to each of the plurality of wireless terminal devices until the upper limit value of the number of receptions for each of the wireless terminal devices is reached, the upper limit value being determined in the second upper limit value determination process; The wireless communication system of claim 1 further configured to perform:

4. The controller the wireless terminal device is further configured to determine, for each of the plurality of wireless terminal devices, at least one of an upper limit value of the number of times the high-priority wireless frame can be received by the wireless terminal device or a sum of the upper limit values ​​of the number of times the high-priority wireless frame can be received in each of the plurality of wireless terminal devices, and notify the wireless base station of the upper limit value; The radio base station determining an upper limit value of the number of times of reception for each of the plurality of wireless terminal devices based on at least one of the upper limit value of the number of times of reception for each of the plurality of wireless terminal devices notified by the controller or the sum of the upper limit values ​​of the number of times of reception for each of the plurality of wireless terminal devices; transmitting the high-priority wireless frame to each of the plurality of wireless terminal devices until the upper limit value of the number of receptions of each of the wireless terminal devices is reached; The wireless communication system of claim 2 further configured to perform the following:

5. 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 time a certain period of time elapses.

6. The wireless communication system according to claim 2 , wherein the controller executes the upper limit determination and notification process every time a certain period of time elapses.

7. 2. The wireless communication system according to claim 1, wherein the wireless base station determines the upper limit of the number of transmissions so that a sum of the upper limit of the number of transmissions in each of the plurality of wireless terminal devices does not exceed a predetermined value.

8. 3. The wireless communication system according to claim 2, wherein when the controller determines the upper limit value of the number of transmissions for each of the plurality of wireless terminal devices, the controller determines the upper limit value of the number of transmissions so that the sum of the upper limit values ​​of the number of transmissions does not exceed a predetermined value.

9. 8. The wireless communication system according to claim 7, wherein the wireless base station determines the upper limit of the number of transmissions based on the communication load of each of the plurality of wireless terminal devices so as to provide fair opportunities to transmit the high-priority wireless frame among the plurality of wireless terminal devices.

10. The wireless communication system according to claim 9 , further comprising a process in which the wireless base station periodically evaluates fairness of the upper limit values ​​of the number of transmissions among the plurality of wireless terminal devices based on communication quality of the wireless terminal devices.

11. 8. The wireless communication system according to claim 7, wherein the wireless base station determines the upper limit of the number of transmissions so as to give more opportunities to transmit the high-priority wireless frame to at least one wireless terminal device among the plurality of wireless terminal devices according to a priority of the wireless terminal device.

12. at least one of the wireless base station and the controller determines an upper limit value of the number of transmissions across a plurality of channels or a plurality of frequency bands; 3. The wireless communication system according to claim 2, wherein 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.

13. 2. The wireless communication system according to claim 1, wherein, in the counting process, the wireless terminal device weights the number of times the high-priority wireless frame has been transmitted depending on a communication control method for transmitting the high-priority wireless frame.

14. A wireless terminal device that performs wireless communication using a wireless frame having identification information indicating a priority, receiving information on an upper limit of the number of times the high-priority wireless frame can be transmitted from another wireless station; transmitting the wireless frames with the higher priority until the upper limit is reached; 20. A wireless terminal device configured to execute the steps of:

15. A wireless base station that performs wireless communication with a plurality of wireless terminal devices using a wireless frame having identification information indicating a priority, an upper limit value determination process for determining and notifying each of the plurality of wireless terminal devices of an upper limit value of the number of times that the wireless terminal device can transmit a high-priority wireless frame; 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 that the wireless terminal device can receive a high-priority wireless frame; Do at least one of the following: a wireless base station configured, when the second upper limit value determination process is executed, to further execute a process of transmitting the high-priority wireless frame to each of the plurality of wireless terminal devices until the upper limit value of the number of receptions for each of the wireless terminal devices determined in the second upper limit value determination process is reached.

16. 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 a priority, determining at least one of an upper limit value of the number of times of transmission and reception of high-priority wireless frames that can be transmitted or received by each of the plurality of wireless terminal devices or a sum of the upper limit values ​​of the number of times of transmission and reception in each of the plurality of wireless terminal devices, and notifying the wireless base station of the upper limit value; A controller configured to perform the processing.

17. According to the priority of the wireless frame, one of the multiple wireless terminal devices is selected to perform wireless communication with the wireless base station. A wireless communication method for preferentially giving an opportunity to transmit and receive a wireless frame to a wireless terminal device that should receive the wireless frame, The wireless base station that performs wireless communication with the plurality of wireless terminal devices, determining, for each of the plurality of wireless terminal devices, an upper limit value of the number of times that the wireless terminal device can transmit a high-priority wireless frame; a process of notifying each of the plurality of wireless terminal devices of the upper limit value of the number of transmissions; Run a process in which the plurality of wireless terminal devices transmit the high-priority wireless frames until the upper limit value of the number of transmissions is reached; counting the number of times the high-priority wireless frame has been transmitted; A wireless communication method for performing

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