Access point device, control method, and program

Abstract

An access point device transmits a trigger frame to one or more other cooperative access points in communications in which the one or more other cooperative access points use an Orthogonal Frequency Division Multiple Access (OFDMA) technology based on at least externally collected information, the trigger frame includes information indicating a frequency resource to be used for communication with a station under its control. The trigger frame includes information in which identification information identifying another access point and information indicating a frequency resource to be allocated to the other access point are associated with each other, and the trigger frame allocates a transmission opportunity using a different frequency resource to each of the one or more other cooperative access points.

Description

Technical Field

[0001] The present invention relates to an access point device for transmitting information. Background Art

[0002] As a communication standard for a wireless local area network (wireless LAN), the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard is known. In the IEEE 802.11be standard and its successor standards, improving communication efficiency and throughput by coordinated operation of multiple access point devices (hereinafter simply referred to as APs) has been considered.

[0003] PTL 1 describes a technique for improving communication efficiency in a congested situation in a wireless communication system conforming to the IEEE 802.11 standard series using OFDMA technology. OFDMA stands for Orthogonal Frequency Division Multiple Access.

[0004] Citation List

[0005] Patent Literature

[0006] PTL 1: Japanese Patent Laid-Open No. 2018-050133 Summary of the Invention

[0007] Technical Problem

[0008] As an example of coordinated operation performed by multiple APs, a more efficient technique called coordinated OFDMA is being considered, in which OFDMA frequency resources are allocated to appropriate APs and multiple APs perform OFDMA communication at the same timing.

[0009] However, the current wireless LAN standard does not define a process or mechanism for appropriately allocating the frequency resources to be used by each AP for OFDMA communication at the same timing, making it difficult to appropriately allocate frequency resources. Additionally, for example, a process for performing OFDMA communication at the same timing has not been defined.

[0010] In view of at least one of the above-mentioned problems, the present invention has been made. One aspect of the present invention is to provide a mechanism for allocating frequency resources for OFDMA communication to multiple APs.

[0011] Solution

[0012] An access point device according to one aspect of the present invention is an access point device that performs wireless communication conforming to the IEEE 802.11 standard. The access point device includes: a transmitting component that transmits a trigger frame to one or more other cooperating access points in communication where one or more other cooperating access points use orthogonal frequency division multiple access (OFDMA) technology based on at least externally collected information. The trigger frame includes information indicating frequency resources to be used for communication with stations under its control. The trigger frame includes information in which identification information identifying another access point and information indicating frequency resources to be allocated to the other access point are associated with each other, and the trigger frame allocates a transmission opportunity using different frequency resources to each of the one or more other cooperating access points.

[0013] Advantages of the invention

[0014] According to one aspect of the present invention, it is possible to allocate frequency resources for OFDMA communication to multiple APs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a diagram showing an example of the configuration of a communication system.

[0016] Figure 2 is a diagram showing the hardware configuration of an access point device.

[0017] Figure 3 is a diagram showing the software configuration of an access point device.

[0018] Figure 4 is a sequence diagram for describing coordinated OFDMA.

[0019] Figure 5 is a diagram showing an example of a frame for collecting information.

[0020] Figure 6 is a diagram showing an example of a frame for response information.

[0021] Figure 7 is a diagram showing an example of a trigger frame for allocating frequency resources.

[0022] Figure 8 is a diagram showing an example of collected information.

[0023] Figure 9 shows an example of control performed by an access point device.

[0024] Figure 10 shows an example of frequency resource allocation control performed by an access point device.

[0025] Figure 11 is a diagram for describing frequency allocation and throughput.

[0026] Figure 12 It is a diagram showing the operating frequency bands of APs 100 to 102. Detailed implementation

[0027] In the following, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments are not intended to limit the invention according to the claims. Although multiple features are described in the embodiments, all of these multiple features may not be essential for the invention, and multiple features can be freely combined. In the drawings, the same or similar configurations are denoted by the same reference numerals, and repeated descriptions are omitted.

[0028] <Configuration of communication system>

[0029] Figure 1 An example of the configuration of a wireless communication system according to this embodiment is shown. This wireless communication system includes three access point devices (hereinafter also simply referred to as APs, AP STAs, access points) and three station devices (hereinafter also simply referred to as STAs, non-AP STAs, stations). Hereinafter, APs 100 to 102 and STAs 120 to 122 will be collectively referred to as communication devices.

[0030] APs 100 to 102 are configured to be able to transmit wireless frames compliant with a successor standard targeting a maximum transmission rate of 90 to 100 Gbps or higher, which is based on the IEEE802.11be standard targeting a maximum transmission rate of 46.08 Gbps. STAs 120 to 122 are similarly configured to be able to transmit wireless frames compliant with the successor standard.

[0031] Note that IEEE represents the Institute of Electrical and Electronics Engineers. This successor standard of 802.11be provides support for reliable and low-latency communication and AP coordination as its main features. Based on the above, in this embodiment, the successor standard of IEEE802.11be targeting a maximum transmission rate of 90 to 100 Gbps or higher will also be referred to as IEEE802.11 Ultra-High Reliability (UHR). The wireless frame for communication under the successor standard is also referred to as UHR PPDU. PPDU represents PLCP Protocol Data Unit, and PLCP represents Physical Layer Convergence Protocol.

[0032] The names IEEE 802.11UHR and UHR standard are established for convenience based on the goals to be achieved in the successor standard and the features that will be the main focus of the standard, and may become different names once the standard has been finalized. In contrast, it should be noted that this specification and the appended claims are essentially applicable to any successor standard of the 802.11be standard that can support features for multiple APs to coordinate to perform OFDMA communication. OFDMA stands for Orthogonal Frequency Division Multiple Access.

[0033] It should be noted that Figure 1 A wireless communication network including three APs and three STAs is shown as an example; however, the number of these units can be more or less than that shown. Assume that APs 100 to 102 and STAs 120 to 122 that support UHR PPDU communication (transmission and reception) can also be configured to support the transfer of PPDUs under legacy standards prior to the UHR standard. Specifically, APs 100 to 102 and STAs 120 to 122 can be configured to support the transmission and reception of PPDUs under, for example, the IEEE 802.11a / b / g / n / ac / ax / be standards.

[0034] APs 100 to 102 are APs that perform coordination operations, and AP 100 is the AP that performs overall control of the coordination. In this embodiment, the AP that performs overall control (such as AP 100) is also referred to as the Coordinator AP. APs 101 to 102 are APs that act as controlled devices controlled by the Coordinator AP. In this embodiment, the APs controlled by the Coordinator AP (such as APs 101 to 102) are also referred to as Coordinated APs. AP 100 provides network 110, AP 101 provides network 111, and AP 102 provides network 112. STAs 120 to 122 are STAs that participate in the networks provided by the access points. Figure 1 A situation is shown where STA 120 participates in network 110 provided by AP 100, STA 121 participates in network 111 provided by AP 101, and STA 122 participates in network 112 provided by AP 102.

[0035] APs 100 to 102 can perform multi-user (MU) communication that communicates with multiple STAs simultaneously using OFDMA technology. In MU communication using OFDMA technology, one channel is divided into multiple sub-channels called resource units (RUs). By using each RU obtained as a result of the division as a resource for communicating with a corresponding different STA (or a STA group composed of multiple STAs), the AP and the multiple STAs can communicate simultaneously on a single channel. In this case, an MU PPDU having data modulated using OFDMA is transmitted from the AP to one or more STAs. In the case where all devices support the UHR standard, it is assumed that a UHR MU PPDU, which is an MU PPDU conforming to the UHR standard, is transmitted to one or more STAs.

[0036] APs 100 to 102 and STAs 120 to 122 can also be configured to support wireless communication based on other communication standards such as NFC and low power (LE). NFC represents near field communication. APs 100 to 102 can also be configured to support wired communication using a cable or an optical fiber to establish a backhaul line. Specific examples of APs 100 to 102 and STAs 120 to 122 include, but are not limited to, wireless LAN routers and personal computers (PCs). APs 100 to 102 and STAs 120 to 122 can be information processing devices such as wireless chips that support the transmission and reception of UHR PPDUs. Specific examples of STAs 120 to 122 include, but are not limited to, cameras, tablet computers, smart phones, PCs, cellular phones, video cameras, and wearable devices such as smart glasses.

[0037] In this embodiment, in the case where APs 100 to 102 provide a network, it is assumed that the BSSID of each network is different. Note that BSSID represents a basic service set identifier and is an identifier for identifying an access point. In contrast, it is assumed that the SSID indicated by APs 100 to 102 in each network is the same. SSID represents a service set identifier and is an identifier for identifying a network.

[0038] Each of the communication devices such as APs 100 to 102 and STAs 120 to 122 can communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 480 MHz, and 640 MHz.

[0039] Subsequently, cooperative operations in which multiple APs (APs 100 to 102) operate in a coordinated manner will be described. The APs 100 to 102 can perform coordinated operations. Specifically, the AP 100 can allocate OFDMA frequency resources to appropriate APs and implement a coordinated OFDMA communication function in which multiple APs including the AP 101 perform OFDMA communication at the same timing.

[0040] Hereinafter, a mechanism for implementing the coordinated OFDMA communication function will be specifically described. To effectively describe the coordinated OFDMA function, it is assumed that in the wireless communication system according to the present embodiment, the APs 100 to 102 provide a network in which STAs can participate using the same operating frequency band and the same bandwidth.

[0041] First, the backhaul line for transmitting and receiving data and control signals between APs will be described. The AP 100 and the APs 101 and 102 can communicate with each other via the backhaul line. The backhaul line can be a communication channel using a wired medium such as a cable (which is, for example, an optical fiber or an Ethernet cable), or can be a communication channel using a wireless medium. Note that when a wireless medium is used as the backhaul line in this wireless communication system, it is necessary to suppress interference to the networks 110 to 112 for the STAs. Therefore, each AP establishes a backhaul line on a frequency channel different from the operating frequency used in the networks 110 to 112, and this backhaul line is a communication link for backhaul communication.

[0042] (Device Configuration)

[0043] Figure 2 An example of the hardware configuration of communication devices (APs and STAs) is shown. As an example of the hardware configuration, each communication device includes a memory unit 201, a control unit 202, a functional unit 203, an input unit 204, an output unit 205, a communication unit 206, and antennas 207 to 209. If the backhaul line is implemented using a wired medium, there can be only one antenna.

[0044] The memory unit 201 includes any one or both of a ROM and a RAM, and stores programs for performing various operations described below, as well as various types of information such as communication parameters for wireless communication. RAM represents random access memory, and ROM represents read-only memory. In addition to memory components such as ROM and RAM, non-volatile storage devices such as hard disks and solid state drives (SSDs) can also be used as the memory unit 201.

[0045] The control unit 202 includes, for example, a processor such as a CPU or an MPU, an application specific integrated circuit (ASIC), a digital signal processor (DSP), a field programmable gate array (FPGA), etc. In this case, CPU is an acronym for Central Processing Unit, and MPU is an acronym for Micro Processing Unit. The control unit 202 controls the entire device by executing a program stored in the memory unit 201 and operating a hardware circuit such as an ASIC. The control unit 202 can control the entire device in cooperation with the program and the operating system (OS) stored in the memory unit 201.

[0046] The control unit 202 also controls the functional unit 203 to perform predetermined processing, such as image capture, printing, and projection. The functional unit 203 is hardware that allows the device to perform predetermined processing. For example, in the case where the communication device is a camera such as a digital still camera or a smart phone having a camera, the functional unit 203 is an image capture unit that performs processing for capturing an image of the surroundings via a camera unit (not shown) of the communication device. For example, in the case where the communication device is a printer, the functional unit 203 is a printing unit that performs a printing process on paper or other media based on print data obtained from the outside via wireless communication. For example, in the case where the communication device is a projector or smart glasses, the functional unit 203 is a projection unit that performs a projection process on image or video data obtained from the outside via wireless communication. In the case of smart glasses, the projection surface is, for example, the retina of the end user. The data to be processed by the functional unit 203 can be data stored in the memory unit 201, or data transferred with other APs or STAs via the communication unit 206 described below. In addition, a communication device such as AP 101 can also provide a network storage function such as network attached storage (NAS). Such a function is provided as a web service such as a network storage service to other communication devices. For example, a communication device such as an STA connects to a network storage service provided by, for example, APs 101 to 103 using protocols such as SMB, FTP, and WebDAV. The communication device such as an STA then uploads a file to such a storage service or downloads a file within such a storage. Such upload and download data communication is also achieved by transferring UHR PPDUs between devices.

[0047] The input unit 204 receives various operations from the user. The output unit 205 provides various outputs to the user. In this case, the output from the output unit 205 includes at least one of, for example, a display on a screen, a sound output from a speaker, a vibration output, and the like. It is possible to implement both the input unit 204 and the output unit 205 in a single module such as a touch panel.

[0048] The communication unit 206 controls wireless communication conforming to the IEEE 802.11 standard series and controls IP communication. In the present embodiment, the communication unit 206 can cooperate with antennas 207 to 209 to transmit and receive a UHR PPDU, which is a wireless frame based on the UHR standard, and a PPDU corresponding to its earlier standard. The antennas 207 to 209 are antennas capable of transmitting and receiving signals in at least one of, for example, the Sub-GHz, 2.4 GHz, 5 GHz, 6 GHz, 7 GHz, and 60 GHz frequency bands.

[0049] In the case where the communication device supports, for example, the NFC and Bluetooth standards mentioned above, it is sufficient for the communication unit 206 to be configured to control wireless communication conforming to these communication standards.

[0050] Subsequently, the functional configurations of the APs 100 to 102 will be described using Figure 3 FIG. Figure 3 is a block diagram for describing the functional configurations of the APs 100 to 102. Figure 3 FIG. shows a selection part of the functional configurations necessary for describing the coordinated OFDMA function. The communication device has a management unit 301, a frame processing unit 302, a frame generation unit 303, a frequency resource allocation determination unit 304, and a frame transmission unit 305. The allocation determination unit 304 indicated by the dashed line is a function of the APs 100 to 102. Note that the STAs 120 to 122 have a similar functional configuration; however, the STAs 120 to 122 do not necessarily have the allocation determination unit 304 indicated by the dashed line.

[0051] Each function will be described. The management unit 301 measures the quality of communication with the STAs participating in its own network and manages the measured information. Specifically, the management unit 301 stores the communication quality in association with the Association Identifier (AID) (identification information of the STA). The identification information of the STA may be identification information other than the AID. In addition, the management unit 301 manages communication parameters necessary for communication with the STA, such as the MCS for communication with other communication devices, information about its own operating frequency band, and information about the bandwidth for transmitting the PPDU. The MCS represents the Modulation and Coding Scheme and is information indicating the modulation and coding scheme to be applied in communication. The coordinating AP also manages, for example, information about the operating frequency band in which the coordinated AP operates and bandwidth information.

[0052] The frame processing unit 302 cooperates with antennas 207 to 209 to interpret various wireless frames received from the outside and send notifications to upper-layer functions (not shown), and performs control processing on wireless communication based on the information obtained by the interpretation. The processing unit 302 also processes the communication quality request frame described below and performs control to determine the information to be included in the response, which is included in the communication quality information managed by the management unit 301. After determining the information to be included in the response, the processing unit 302 makes a request to the generation unit 303 to generate a response frame and include the information to be included in the response. The processing unit 302 of the coordinating AP processes the response frame to the communication quality request frame received from the coordinated AP and acquires the communication quality information about the coordinated AP. The acquired information is transmitted to the management unit 301. The management unit 301 that has received the transmitted information manages this information as the communication quality information about the coordinated AP.

[0053] The frame generation unit 303 generates wireless frames such as the UHR PPDU mentioned above based on data received from upper-layer functions (not shown). The frame generation unit 303 also generates wireless frames for controlling wireless communication and coordinating operations based on requests from the processing unit 302 and the determination unit 304. The wireless frames for controlling the coordination operation generated by the generation unit 303 will be described. The generation unit 303 may generate a frame for requesting information about the quality of communication with the STAs participating in the network from other APs. When the generation unit 303 receives a request including the frequency resource allocation information determined by the determination unit 304 described below, the generation unit 303 generates a frame that causes the coordinated AP to transmit a data frame. The frame transmission unit 305 cooperates with antennas 207 to 209 to transmit wireless frames such as the UHR PPDU generated by the generation unit 303 to external APs and STAs. The specific format of the frames for coordinating communication will be described below.

[0054] The determination unit 304 determines the allocation of frequency resources for each coordinated AP and itself based on information such as communication quality information collected from the coordinated APs and communication quality information measured and managed by the management unit 301 itself. The determination unit 304 then requests from the generation unit 303 the generation of a frame including the determined frequency resources and causes the coordinated APs to transmit data frames.

[0055] <Coordinated OFDMA>

[0056] Subsequently, Figure 4 The sequence diagram in Figure 4 is a sequence diagram showing an example of wireless frame exchange in the case of performing the coordinated OFDMA function.

[0057] The AP 100, as the coordinator AP, measures and manages in advance the quality of communication with the STAs participating in its own network (400). The communication quality can be measured in advance by the AP transmitting a communication quality measurement frame to the STA and obtaining the communication quality when the STA receives the frame from the STA. In the present embodiment, the communication quality is measured for each frequency resource obtained as a result of division and referred to as a resource unit (RU). For example, when the AP 100 transmits a wireless frame using a predetermined bandwidth such as 40 MHz, the communication quality is measured for each subcarrier of the 26-tone RU that constitutes the smallest unit of the RU. The unit of measurement and the method of measuring the communication quality are not limited to this. For example, the AP can measure the communication quality for each RU by measuring the reception level of the probe request frame transmitted by the STA. Other wireless frames can also be used to measure the communication quality for each RU. When there are multiple STAs under the control of the AP, it is assumed that the communication quality of each STA is to be measured. The APs 101 and 102, as the coordinated APs, also perform substantially the same pre-measurement process (401, 402) and manage the quality of communication with the STAs connected to their networks. In the case where a single STA has the ability to establish multiple communication links, a single STA can participate in the networks of multiple APs simultaneously.

[0058] Once the pre-measurement is completed, the collection process is performed by the coordinator AP 101. Specifically, the AP 100 transmits an AP channel quality trigger frame as a communication quality request frame to obtain communication quality information from the APs 101 and 102 as the coordinated APs (410).

[0059] This frame is broadcast to the surrounding area including the APs 101 and 102. The APs 101 and 102 transmit an AP channel quality frame as a response frame including the communication quality in response to this frame (411, 412).

[0060] will be usedFigure 5 and Figure 6 Describe the AP Channel Quality Trigger Frame and the AP Channel Quality Frame. Hereinafter, the AP Channel Quality Trigger Frame will be abbreviated and also referred to as APCQTF.

[0061] Figure 5 An example of the format of the AP Channel Quality Trigger Frame transmitted by the coordinator AP 100 to APs 102 and 103 is shown.

[0062] The Frame Control Field 501 includes a Type sub-field and a Subtype sub-field that indicate the frame type. In this embodiment, a frame in which the Type sub-field is set to "01" indicating a control field and the Subtype sub-field is set to "0001" indicating an AP trigger is defined as an AP trigger type frame. Table 1 is a table describing the frame types.

[0063] [Table 1]

[0064] Table 1

[0065]

[0066] The Duration Field 502, the RA Field 503, and the TA Field 504 correspond to the content of the MAC header of the trigger frame which is a control frame defined in the IEEE 802.11ax standard.

[0067] The AP Common Information Field 505 includes information common to all APs. The Trigger Type Field 509 includes information identifying the trigger frame to be transmitted to the AP as shown in Table 2. For example, in the case of the AP Channel Quality Trigger Frame, the trigger type is set to 0. In the case of the AP DL Data Trigger Frame which is a frame for causing the coordinated AP to transmit a data frame, the trigger type is set to 1.

[0068] [Table 2]

[0069] Table 2

[0070] Sub - field value Trigger frame type 0 AP channel quality 1 AP DL data 2-15 Reserved

[0071] Subsequently, the Channel Quality Type Field 510 indicates the type of communication quality requested. Table 3 is used to describe the types. Table 3 shows the values that can be stored in the Channel Quality Type Field 510 and their descriptions.

[0072] [Table 3]

[0073] Table 3

[0074] Sub - field value Type of requested communication quality 0 RSSI (Received Signal Strength Indicator) 1 SNR (Signal - to - Noise Ratio) 2 CNR (Carrier - to - Noise Ratio) 3 Data rate 4 MCS (Modulation and Coding Scheme) information 5 Error rate 6 Communication availability 7-15 Reserved

[0075] The coordinator AP 100 sets the corresponding subfield to a value corresponding to the type of the requested communication quality. This field can also be configured to set the requested value in the form of a bitmap field, where a value of 1 is set for the requested type and a value of 0 is set for the unrequested type. Table 4 is an example of a bitmap field defined to specify the requested communication quality in an 8-bit bitmap field.

[0076] [Table 4]

[0077] Table 4

[0078] Bit value Type of requested communication quality B0 RSSI (Received Signal Strength Indicator) B1 SNR (Signal - to - Noise Ratio) B2 CNR (Carrier - to - Noise Ratio) B3 Data rate B4 MCS (Modulation and Coding Scheme) information B5 Error rate B6 Communication availability B7-8 Reserved

[0079] In this embodiment, the error rate requested by the APCQTF can specifically be any one of a packet error rate, a bit error rate, or a frame error rate.

[0080] The communication availability-unavailability information indicates whether communication between the STA and the coordinated AP is possible. As a communication availability-unavailability response, the coordinated AP responds, for example, using a bitmap field in which a value of 0 or 1 is specified for each 26-tone RU. A 0 indicates that communication is not possible, while a 1 indicates that communication is possible. The RU size is an example, and a configuration in which communication availability / unavailability is responded to for RUs equivalent to a larger number of tones is also possible.

[0081] The AP information field 506 as a subsequent field stores information addressed to the coordinated AP. For example, in the presence of N coordinated APs, the APCQTF includes N AP information fields, which are the AP information fields 506-1 to 506-N.

[0082] Each AP information field stores information about the corresponding one of the APs from which the communication quality is requested. The AP ID field 511 stores information for identifying the AP. As identification information, information that uniquely identifies the AP performing the coordination operation can be used. Examples of this information include Media Access Control (MAC) address, BSSID, and BSS Color identification. The channel field 512 includes the channel through which communication quality is provided as feedback and includes information for identifying the frequency band, the channel number, and the resource unit (RU). The RU allocation field 513 is information indicating the RU allocation to be used when the coordinated AP transmits a response frame including communication quality while using OFDMA simultaneously.

[0083] The padding field 507 is a field used to ensure the processing time of the coordinated AP's transmission of the response frame. The 802.11ax and later standards specify that a trigger-based PPDU (TBPPDU) as a response to the trigger frame should be transmitted after the SIFS time has elapsed since the completion of the reception of the trigger frame. SIFS represents the Short Inter-Frame Space. Therefore, by storing padding information (also referred to as padding data) in the padding field and deliberately delaying the completion of reception, the processing time for the coordinated AP to generate the TB PPDU can be ensured. In the case of causing a delay through padding, the size of the padding information is set based on a predetermined size value set at the time of factory shipment based on general computing power, etc.

[0084] The method for ensuring the processing time is not limited to this. A field can be provided to specify the transmission start time of the response frame in response to the trigger frame using an offset value, etc., and the response time can be designed to be adjusted based on the value of this field. This SIFS time and the offset-based waiting time are examples of predetermined times. For other trigger frames described below, the response start time can also be designed to be adjusted in the same way using the offset value.

[0085] Finally, the FCS field 508 stores frame check sequence information for frame error detection.

[0086] In this embodiment, it will be described assuming that the APCQTF is to be transmitted, where APs 101 and 102 are specified as the destinations for issuing the communication quality feedback request.

[0087] Returning to Figure 4 the description, the coordinated APs 101 to 102 that have received the APCQTF generate an AP channel quality frame indicating communication quality information before the SIFS time has elapsed after the completion of the reception of the APCQTF. Hereinafter, this frame is abbreviated and also referred to as APCQ. The format of this frame is a TB PPDU. Then, each of APs 101 to 102 transmits the APCQ frame (411, 412) in which the communication quality information is modulated through the subcarriers corresponding to the RUs assigned to it in the AP information field at the timing when the SIFS time has elapsed after the completion of the reception of the APCQTF.

[0088] The APCQ frame will be specifically described using Figure 6 Specifically. Figure 6 An example of the format of the APCQ frame transmitted by the coordinated APs 101 and 102 is shown.

[0089] The frame control field 601 includes a type subfield and a subtype subfield indicating the frame type. In this embodiment, as shown in Table 1, the APCQ frame is defined as a frame in which the type subfield is set to 01 and the subtype subfield is set to 0000.

[0090] Note that as long as the AP channel quality frame can be recognized, the type and subtype sub-fields can have different values. For example, as shown in Table 5, a frame in which the type sub-field is set to indicate Extended 11 and the subtype sub-field is set to, for example, 0011 can be defined as an APCQ frame. The above-mentioned AP trigger type frame can also be defined as a frame belonging to the extended type. For example, a frame in which the type sub-field is set to indicate Extended 11 and the subtype sub-field is set to, for example, 0100 can be defined as an AP trigger type frame.

[0091] [Table 5]

[0092] Table 5

[0093]

[0094] The Duration field 602, RA field 603, and TA field 604 match the content of the MAC header based on the IEEE 802.11 standard and are set to indicate that the AP 100 (coordinator AP) is the destination.

[0095] The AP ID field 605 stores identification information for identifying the coordinated AP. The identification information is sufficient to be a MAC address, BSSID, BSSColor, or other information that uniquely identifies the AP.

[0096] As a subsequent field, the STA information field 606 stores information about each STA under the control of this coordinated AP. In the case where there are N STAs under the control of the coordinated AP, the APCQ frame includes N fields, which are the STA information fields 606-1 to 606-N.

[0097] The content of each STA information field will be further described.

[0098] The STA ID field 606 stores identification information for identifying the STA. In this embodiment, it is assumed that the AID is used as the identification information for the STA, but it is not limited thereto. For example, other identification information such as a MAC address can be used.

[0099] The Channel field 612 includes information indicating the channel for which communication quality is provided as feedback and identifying the frequency band, channel number, and resource unit (RU).

[0100] The Channel Quality field 613 includes the communication quality information specified in the Channel Quality Type field 510 of the APCQTF. Figure 6 An example of a response transmitted when the Channel Quality Type field 510 of the APCQTF is set to 1 is shown, and the SNR of each RU is stored in 621 to 624.

[0101] The processing units 302, management unit 301, and generation unit 303 of the coordinated APs 101 and 102 cooperate to extract the communication quality information to be provided as feedback from various types of communication quality information managed by the management unit 301, and set the extracted communication quality information in the APCQ frame.

[0102] Return to Figure 4 the description of, as the coordinator AP of the APCQ frame received in 411 and 412, AP100 stores in the management unit 301 the quality information about the coordinated AP included in the received APCQ frame.

[0103] Figure 8 is a diagram showing an example of the communication quality information collected and managed by the coordinator AP 100. This example shows the communication quality information obtained when the SNR is specified in the channel quality type field 510, and the communication quality information about and managed by the AP 100. 801 represents the communication quality obtained when the AP 100 and the STA 120 use RU#0 to RU#3, and 802 represents the communication quality obtained when the AP 100 and the STA 121 use RU#0 to RU#3. 803 represents the communication quality obtained when the AP 102 and the STA 122 use RU#0 to RU#3. For example, when the AP 101 communicates with the STA 121 using RU#1, the SNR is found to be 15 dB. The data rate of the wireless communication is determined by the MCS selected based on the SNR. For simplicity of description, as an example, the case where the number of STAs participating in each AP is 1, the size of one RU is 20 MHz, and the measurement target RU size of the communication quality is also 20 MHz is shown. However, the values are not limited to these.

[0104] Return to Figure 4 the description of. In this embodiment, frequency resources are allocated to each AP such that the total communication throughput during the period indicated by the coordinated OFDMA data transmission period in the figure is increased. The communication throughput will be described using Figure 11 to describe the communication throughput. Figure 11It is a diagram that describes the relationship among SNR, MCS, and communication throughput. In the case of a high noise ratio, the MCS needs to be reduced to withstand the noise. In the case of a low noise ratio, communication can be performed with a high MCS. For example, when the noise ratio is less than or equal to 5 dB, communication is not possible and the throughput is 0 Mbps. For example, when the noise ratio is 6 to 10 dB, binary phase shift keying (BPSK) is used as the modulation method and a coding rate of 1 / 2 is used. Therefore, if it is assumed that frequency resources with a bandwidth of 20 MHz are used, a throughput of 8.6 Mbps is expected. When the noise ratio is 11 to 15 dB, quadrature phase shift keying (QPSK) is used as the modulation method and a coding rate of 3 / 4 is used. Therefore, if it is assumed that frequency resources with a bandwidth of 20 MHz are used, a throughput of 25.8 Mbps is expected. When the noise ratio is 16 to 20 dB, quadrature amplitude modulation (16QAM) is used as the modulation method and a coding rate of 3 / 4 is used. Therefore, if it is assumed that frequency resources with a bandwidth of 20 MHz are used, a throughput of 51.6 Mbps is expected. Using this communication quality information, AP 101 can determine the allocation of frequency resources to APs 102 and 103 to improve communication efficiency. In this example, when AP 101 is allocated RU#0, AP 101 is allocated RU#1, and AP102 is allocated 40 MHz frequency resources formed by RU#2 and RU#3, it can be seen that the physical throughput is improved, enabling more efficient communication. The frequency resource allocation process will be specifically described below using Figure 10 Specifically describe the frequency resource allocation process. In this example, for each AP, the quality of communication with one STA is indicated, but each AP can obtain the quality of communication with two or more STAs.

[0105] Return to Figure 4 the description of, and the process of allocation where coordinated OFDMA processing can be performed will be described.

[0106] AP 100 performs the process (413) of determining the allocation of RUs to be used in coordinated OFDMA based on the quality information, operating frequency, and other information managed by the management unit 301. Subsequently, AP 100 transmits an AP DL data trigger frame (420), which is a data transmission request frame including frequency resource information, to the coordinated APs 101 to 102. Hereinafter, the AP DL data trigger frame is also referred to as APDLTF.

[0107] will use Figure 7 Specifically describe APDLTF. Figure 7 Shows an example of the format of the APDLTF transmitted by the coordinated AP 100.

[0108] The frame control field 701 includes a type sub-field and a subtype sub-field that indicate the frame type. To indicate that this is a trigger frame for AP coordination as shown in Table 1 mentioned above, the type sub-field is set to 01, and 0001 is specified in the subtype sub-field. The duration field 702, the RA field 703, and the TA field 704 correspond to the contents of the MAC header of the trigger frame which is a control frame defined in the IEEE 802.11ax standard.

[0109] The AP common information field 705 as a subsequent field includes information common to all APs. The trigger type field 709 stores the information for identifying the trigger frame as shown in Table 2. In the case of APDLTF, “1” shown in Table 2 is stored. Although not shown in Figure 7 the AP 100 can cause the AP common information field 705 to include various other types of information to be reported to the coordinated APs.

[0110] The AP information field 706 as a subsequent field stores pieces of information addressed to these respective APs. In the case where there are N coordinated APs, the AP information field 706 includes N fields, which are the AP information fields 706-1 to 706-N. Information addressed to the AP 100 itself can also be stored in this field. In this case, the APDLTF includes N+1 fields.

[0111] The content of the AP information field will be further described. The AP information field of the APDLTF stores the information to be reported to each AP. Specifically, the information identifying the frequency resources to be used for the downlink MU OFDMA transmission is stored.

[0112] The AP ID field 710 stores the information for identifying the AP. The identification information is the identification information that uniquely identifies the AP, such as the MAC address, BSSID, BSS Color, or other information.

[0113] The channel field 711 stores the information including the frequency band and the channel number, which is the channel information that the coordinated AP is allowed to use to transmit downlink data. In this embodiment, the minimum frequency resource allocated to each AP is 20 MHz bandwidth to avoid interference between the preambles of the UHR MUPPDUs transmitted by each AP when performing simultaneous transmission using coordinated OFDMA.

[0114] The AP RU allocation field 712 stores information indicating RU allocation when the coordinated AP transmits a DL frame using OFDMA. The STA information field 713 stores information about the STA to which the coordinated AP is to transmit a DL frame using OFDMA. The STA ID field 714 stores identification information for identifying the STA. This identification information is assumed to be, but is not limited to, the AID of the STA. For example, other identification information such as a MAC address or BSSID can be used.

[0115] The STA RU allocation field 715 stores information indicating the RU to be used when the coordinated AP transmits data to the STA corresponding to the STA ID field 714. The MCS index field 716 stores information indicating the MCS to be applied when transmitting a DL data frame to the STA corresponding to the STA ID field 714.

[0116] The padding field 707 is a field used to ensure the processing time for the coordinated AP to transmit an OFDMA MU PPDU to multiple STAs under its control. The FCS field 708 stores frame check sequence information for frame error detection.

[0117] Return Figure 4 Description. APs 101 to 102 that have received the APDLTF transmitted from AP 100 and AP 100 generate AP DL data frames for transmitting data to STAs under their control before the SIFS time has elapsed. In this case, APs 101 to 102 determine the STAs to be targeted for simultaneous transmission using DL MU OFDMA based on the information included in the APDLTF and the corresponding AP information. Each AP DL data frame generated in this case is a UHRMU PPDU format frame that stores information indicating OFDMA transmission, its destination STA, and the RU allocation status in the frame preamble. Then, each of APs 100 to 102 transmits the AP DL data frames (421, 422, 423) as DL MU PPDUs at a timing when the SIFS time has elapsed after the reception of the APCQTF is completed. Figure 4An example of allocation is shown for the case where the frequency bandwidth for coordinated OFDMA transmission is 80 MHz. More specifically, the case is shown where AP 100 is allocated RU#0 corresponding to a 20 MHz sub-band and AP 101 is allocated RU#1 corresponding to a 20 MHz sub-band. The case is shown where AP 102 is allocated RU#2 as a 40 MHz frequency resource corresponding to two 20 MHz sub-bands. Each AP uses the allocated frequency resource to transmit data to one or more STAs under its control. The actual data transmitted to the STAs in this frame is user data that has been previously transmitted from AP100 to APs 101 to 102, which are coordinated APs, via a backhaul line. Typical examples of user data are video, audio, and images.

[0118] When the SIFS time has elapsed after reception completion, each STA that has received the data transmits an ACK to the AP that is the data transmission source, and a series of processes for transmission while completing the coordinated OFDMA function are completed.

[0119] Subsequently, Figure 9 and Figure 10 The flowchart in Figure 9 and Figure 10 describes the control executed by the coordinator AP 100. The flowcharts in Figure 3 show a selection part of the process for implementing coordinated OFDMA. Each process indicated in each flowchart is executed by a processor of the control unit 202 of AP 100 by executing a computer program stored in the memory unit 201. Some processes such as transmission and modulation are realized by the cooperation of the processor of the control unit 202, the communication unit 206, and ASIC, DSP, FPGA, etc. of the control unit 202. In the case where it is desired to clearly indicate the subject of the process, the functional unit described in

[0120] is used as the subject of the description.

[0121] In S903, the processing unit 302 obtains communication quality information from a response frame received via at least one or more of antennas 207 to 209 and demodulated by the communication unit 206, and reports the obtained information to the management unit 301. The response frame received and demodulated in S903 is the APCQ frame mentioned above. The management unit 301 updates the current management information regarding the coordinated AP based on the reported communication quality information. This process updates the communication quality information regarding the coordinated AP managed by the management unit 301.

[0122] In S904, the determination unit 304 performs a process of determining the allocation of frequency resources to the AP 100 and the coordinated APs such as AP 101 to 102. This process will be described using Figure 10 When the AP 100 finishes the process of determining the allocation of frequency resources to each AP, the process proceeds to S905.

[0123] In S905, the generation unit 303 generates an APDLTF (data transmission request frame) based on the frequency allocation information determined in S904. Subsequently, the generation unit 303 collaborates with the transmission unit 305, the communication unit 206, and one or more antennas to transmit the generated APDLTF to the outside. When the AP 101 finishes the transmission, the process proceeds to S906.

[0124] Finally, in S906, the generation unit 303 generates a UHR MU PPDU at a timing when the SIFS time has elapsed since the completion of the reception of the APDLTF transmitted in S905. This UHR MU PPDU is a MU PPDU in which the RU to be used for data transmission to one or more STAs under its control is determined based on the frequency allocation information indicated in the APDLTF and the data of each STA is stored in the RU. Subsequently, the generation unit 303 collaborates with the transmission unit 305, the communication unit 206, and one or more antennas to transmit the generated UHR MU PPDU to the outside.

[0125] In this case, as described using Figure 4 The APs 101 and 102, which are the coordinated APs, also simultaneously transmit UHR MU PPDUs for transmitting data to the STAs under their control using OFDMA. That is, the APDLTF assigns a transmission opportunity in the coordinated OFDMA data transmission period to each coordinated AP. In this case, as shown in Figure 4 The RUs obtained by dividing a certain frequency width can be shared by the coordinated APs and the coordinating AP, enabling coordinated OFDMA communication in which multiple APs are coordinated.

[0126] In the case where the offset value indicating the time to start transmitting the response frame is specified in the field of the APDLTF transmitted by the AP 100, it is sufficient for each AP to transmit the MU PPDU at the timing when the time specified by the offset value has elapsed.

[0127] Each AP can transmit data using the HE MU PPDU based on the previous standard in the case where there is a STA under its control that only supports the previous standard (such as IEEE 802.11ax).

[0128] Finally, Figure 10 Describe the frequency resource allocation process. Figure 10 is a flowchart describing the details of the allocation process performed in S904.

[0129] In S1001, the determination unit 304 initializes the variable m to 0, where the variable m stores the maximum total throughput used when determining the optimal frequency resource allocation. Next, in S1002, the AP 100 selects a frequency resource allocation pattern for which it has not yet calculated the total throughput. For example, RU#0 is allocated to the AP 100, RU#1 is allocated to the AP 101, RU#2 is allocated to the AP 102, and RU#3 is allocated to the AP 102. Next, in S1003, the determination unit 304 calculates the total communication throughput value N estimated based on the selected frequency resource allocation pattern and the communication quality information regarding each AP managed by the management unit 301. This N means the expected communication throughput of the transmission performed in a certain resource allocation pattern during the coordinated OFDMA data transmission period.

[0130] Subsequently, in S1004, the determination unit 304 determines whether the value N calculated in S1003 is greater than the value of the variable m. In the case where it is determined that the value N is greater than the value of the variable m, the process proceeds to S1005. In the case where it is determined that the value N is not greater than the value of the variable m, the process in S1005 is skipped and the process proceeds to S1006.

[0131] In S1005, the determination unit 304 updates the variable m with N and stores the pattern selected in S1002 as the allocation candidate pattern.

[0132] In S1006, the determination unit 304 determines whether all frequency allocation patterns have been tried. In the case where all frequency allocation patterns have been tried, the process proceeds to S1007. In the case where there are frequency allocation patterns that have not been tried, the process proceeds to S1002 to try another pattern to see if there is a pattern with higher throughput.

[0133] In S1007, the determination unit 304 determines that the frequency resources to be allocated to each AP will be the allocation candidate patterns stored in S1005, and the process proceeds to Figure 9 S905 in

[0134] In this way, the AP 100 searches for a frequency allocation pattern with high throughput by selecting multiple frequency resource allocation patterns and repeating the same determination process. For example, consider the first case where RU#0 is allocated to the AP 100, RU#1 is allocated to the AP101, and RU#2 and RU#3 are allocated to the AP 102. In this first case, the physical throughput of the AP 100 is 8.6 Mbps, the physical throughput of the AP 101 is 25.8 Mbps, and the physical throughput of the AP 102 is 51.6 + 25.8 Mbps. Therefore, the total throughput in the first case is 111.8 Mbps. Additionally, for example, consider the second case where RU#0 is allocated to the AP102, RU#1 is allocated to the AP 101, and RU#2 and RU#3 are allocated to the AP 100. In this second case, from Figure 8 and Figure 11 the table in, the physical throughput of the AP 100 is 8.6 Mbps, the physical throughput of the AP 101 is 25.8 Mbps, and the physical throughput of the AP 102 is 8.6 Mbps. Therefore, the total throughput in the second case is 43 Mbps. Comparing the total throughputs obtained from these two frequency resource allocation patterns and the communication quality, it can be seen that the allocation pattern shown in the first case is efficient. It becomes possible to select the frequency resource allocation pattern with the highest throughput by separately calculating the total throughputs of all frequency resource allocation patterns.

[0135] The method for determining frequency resource allocation described in this embodiment is an example and is not limited to this method. For example, determination processing can also be performed to satisfy other conditions. For example, the AP 100 can estimate the amount of data that each AP plans to transmit, and in view of the estimated data amount and communication quality information, determination processing can be performed to select a pattern that enables each AP to transmit the estimated data amount.

[0136] (Modification)

[0137] The types of communication quality that can be queried via the APCQTF are not limited to those described in the above embodiments. For example, SINR, CINR, etc. can be included in the types of communication quality that can be queried. SINR represents the signal-to-interference-plus-noise ratio. CINR represents the carrier-to-interference-and-noise ratio.

[0138] Figure 9The communication quality information collection processing and allocation determination processing described in S902 and S903 can also be simplified so that the collection and allocation processing is performed at a predetermined interval (such as once every several tens of minutes) to suppress the overload of communication and computing resources for the communication quality information collection processing and allocation determination processing. In this case, it is sufficient for the AP 100 to issue the APDLTF of S905 when it is determined based on, for example, the estimated data volume to be transmitted by each AP that the coordinated AP needs to be notified. In this case, the AP 100 issues an APDLTF in which the AP RU allocation field 712 and the STA information field 713 in Figure 7 are omitted. This means that only a rough frequency resource allocation is reported to the coordinated AP. The coordinated AP that has received the APDLTF autonomously determines, based on the data volume in the data buffer and other factors, which STA under its control will be allocated what size of RU within a given frequency resource. Then, it is sufficient to transmit the MU PPDU in which the data is stored based on the determined RU allocation.

[0139] In the above-described embodiment, the case where the coordinator AP 100 and the coordinated APs 101 and 102 operate in the same frequency band is illustrated, but it is not limited thereto. Each AP can participate in the simultaneous transmission through the coordinated OFDMA function if a part of the operating frequency band of the network it provides overlaps. In this case, Figure 9 it is sufficient for the allocation processing in Figure 12 to consider the operating frequency band in which each AP is operating and impose constraints on the allocation pattern. This will be briefly described using Figure 12 FIG. shows the case where the operating frequencies of each AP are different but partially overlap. In this case, for example, the AP100 attempts not to allocate RU#0 and RU#1 to the coordinated AP 102. Similarly, the AP 100 attempts not to allocate RUs that do not match the operating frequency to other coordinated APs.

[0140] Although the above-described embodiment has described the coordinated OFDMA function for the downlink, the present invention can also be applied to the coordinated OFDMA function for the uplink. In this case, the received use of Figure 4Each coordinated AP of the APDLTF described in 420 and the coordinator AP 100 generate a basic trigger frame that causes uplink MU OFDMA. Subsequently, each AP transmits the generated basic trigger frame to the STAs under its control. Hereinafter, the basic trigger frame will also be referred to as the BTF. In this case, after the BTF reception is completed and after the SIFS time has elapsed, it is sufficient for each STA that has received the BTF to transmit a TB PPDU in which the data is stored in the RU specified by the BTF to the AP from which the BTF was transmitted.

[0141] The present invention can also be applied to multiple cooperative APs based on Wi-Fi In this case, the coordinated APs act as Wi-Fi controllers and one or more other cooperative access points act as Wi-Fi agents.

[0142] The disclosure of this embodiment includes the following configurations.

[0143] (Configuration 1)

[0144] An access point device that performs wireless communication conforming to the IEEE 802.11 standard, the access point device comprising: a transmission component that transmits a trigger frame to one or more other cooperative access points in communication where the one or more other cooperative access points use orthogonal frequency division multiple access (OFDMA) technology based on at least externally collected information, the trigger frame including information indicating frequency resources to be used for communication with a station,

[0145] and

[0146] the trigger frame includes information in which identification information identifying another access point and information indicating frequency resources to be allocated to the other access point are associated with each other, and the trigger frame allocates a transmission opportunity using different frequency resources to each of the one or more other cooperative access points.

[0147] (Configuration 2)

[0148] The access point device according to Configuration 1, further comprising: a collection component that collects information about communication quality from another cooperative access point, and

[0149] the externally collected information includes the information collected by the collection component.

[0150] (Configuration 3)

[0151] The communication device according to Configuration 2, wherein the collection component transmits a query frame for information regarding communication quality to the other collaborative access point, and collects information regarding communication quality by receiving a response to the frame.

[0152] (Configuration 4)

[0153] The access point device according to Configuration 3, wherein in the query frame, one or more pieces of information among received signal strength indicator (RSSI), signal-to-noise ratio (SNR), signal-to-interference-plus-noise ratio (SINR), carrier-to-noise ratio (CNR), carrier-to-interference-and-noise ratio (CINR), data rate, MCS, error rate, and communication availability-unavailability information are specified as information to be queried.

[0154] (Configuration 5)

[0155] The access point device according to Configuration 4, wherein the query frame transmitted by the access point device is a second trigger frame, information to be queried is specified in the second trigger frame, and at a timing after a predetermined time has elapsed since the reception of the trigger frame, the other collaborative access point that has received the second trigger frame transmits a response including data as a response to the second trigger frame, and the data indicates communication quality of a type specified as the query object.

[0156] (Configuration 6)

[0157] The access point device according to any one of Configurations 1 to 5, wherein the trigger frame includes padding information of a predetermined size to allow the one or more other collaborative access points to use the OFDMA technique at the same timing, and

[0158] at a timing after a predetermined time has elapsed since the completion of the reception of the trigger frame including the padding information, the one or more other collaborative access points communicate with stations under their control using the frequency resources allocated by the trigger frame using the OFDMA technique.

[0159] (Configuration 7)

[0160] The access point device according to any one of Configurations 1 to 6, wherein the trigger frame further includes information in which identification information identifying the access point device and information indicating frequency resources to be allocated to the access point are associated with each other, and each of the one or more other collaborative access points and the access point are allocated different frequency resources.

[0161] (Configuration 8)

[0162] The access point device according to any one of Configurations 1 to 7, wherein the access point is a device acting as a Wi-Fi EasyMesh (registered trademark) controller, and the one or more other cooperative access points are devices acting as Wi-Fi EasyMesh agents.

[0163] (Configuration 9)

[0164] The access point device according to any one of Configurations 1 to 8, wherein at a timing when a predetermined time has elapsed after the reception of the trigger frame is completed, the one or more other cooperative access points perform communication for transmitting an ultra-high reliability (UHR) multi-user (MU) PLCP protocol data unit (PPDU) using the frequency resources allocated by the trigger frame for transmitting downlink data to one or more stations under its control.

[0165] (Configuration 10)

[0166] A control method for an access point device, the access point device performing wireless communication conforming to the IEEE 802.11 standard, the control method comprising:

[0167] In communication where one or more other cooperative access points use orthogonal frequency division multiple access (OFDMA) technology based on at least externally collected information, a transmission step of transmitting a trigger frame to the one or more other cooperative access points, the trigger frame including information indicating frequency resources to be used for communication with stations,

[0168] And

[0169] The trigger frame includes information in which identification information identifying another access point and information indicating frequency resources to be allocated to the other access point are associated with each other, and the trigger frame allocates a transmission opportunity using different frequency resources to each of the one or more other cooperative access points.

[0170] (Configuration 11)

[0171] A program for causing a computer to execute the control method for an access point device according to Configuration 10.

[0172] (Other Embodiments)

[0173] The present invention can also be implemented by a program that implements one or more of the functions of the above-described embodiments being supplied to a system or device via a network or a storage medium and a process in which one or more processors in a computer of the system or device read and execute the program. The present invention can also be implemented by a circuit (e.g., ASIC) that implements one or more functions.

[0174] The invention is not limited to the embodiments mentioned above, and various changes and modifications are possible without departing from the spirit and scope of the invention. Therefore, the claims are attached to disclose the scope of the invention to the public.

[0175] This application claims the benefit of Japanese Patent Application No. 2022-178313, filed on November 7, 2022, which is hereby incorporated herein by reference in its entirety.

Claims

1. An access point device that performs wireless communication compliant with the IEEE 802.11 standard, the access point device comprising: a transmission component that transmits a trigger frame to one or more other cooperating access points in communication where one or more other cooperating access points use orthogonal frequency division multiple access (OFDMA) technology based on at least externally collected information, the trigger frame including information indicating frequency resources to be used for communication with a station, wherein, the trigger frame includes information in which identification information identifying another access point and information indicating frequency resources to be allocated to the other access point are associated with each other, and the trigger frame allocates a transmission opportunity using different frequency resources to each of the one or more other cooperating access points.

2. The access point device according to claim 1 further comprises: a collection component that collects information on communication quality from another cooperating access point, wherein the externally collected information includes the information collected by the collection component.

3. The access point device according to claim 2, wherein, The collection component transmits a query frame for information on communication quality to the other cooperating access point and collects information on communication quality by receiving a response to the frame.

4. The access point device according to claim 3, wherein, In the query frame, information designating one or more pieces of information among received signal strength indicator (RSSI), signal-to-noise ratio (SNR), signal-to-interference-plus-noise ratio (SINR), carrier-to-noise ratio (CNR), carrier-to-interference-and-noise ratio (CINR), data rate, MCS, error rate, and communication availability-unavailability information as query objects is specified.

5. The access point device according to claim 4, wherein, The query frame transmitted by the access point device is a second trigger frame in which information to be used as a query object is specified, and at a timing after a predetermined time has elapsed since the reception of the trigger frame, the other cooperating access point that has received the second trigger frame transmits a response including data as a response to the second trigger frame, the data indicating the communication quality of the type designated as the query object.

6. The access point device according to claim 1, wherein, The trigger frame includes padding information of a predetermined size to allow the one or more other cooperating access points to use OFDMA technology at the same timing, and at a timing after a predetermined time has elapsed since the reception of the trigger frame including the padding information, the one or more other cooperating access points communicate with stations under their control using the frequency resources allocated by the trigger frame using OFDMA technology.

7. The access point device according to claim 1, wherein The trigger frame further includes information in which identification information identifying the access point device and information indicating frequency resources to be allocated to the access point are associated with each other, and each of the one or more other cooperating access points and the access point are allocated different frequency resources.

8. The access point device according to claim 1, wherein, The access point is a device acting as a Wi-Fi EasyMesh (registered trademark) controller, and the one or more other cooperating access points are devices acting as Wi-Fi EasyMesh agents.

9. The access point device according to any one of claims 1 to 8, wherein, At a timing when a predetermined time has elapsed after reception of the trigger frame is completed, the one or more other cooperative access points perform communication for transmitting an ultra-high reliability (UHR) multi-user (MU) physical layer convergence protocol data unit (PPDU) using frequency resources allocated by the trigger frame for transmitting downlink data to one or more stations under its control.

10. A control method for an access point device that performs wireless communication conforming to the IEEE 802.11 standard, the control method comprising: In communication in which one or more other cooperative access points use orthogonal frequency division multiple access (OFDMA) technology based on at least externally collected information, a transmission step of transmitting a trigger frame to the one or more other cooperative access points, the trigger frame including information indicating frequency resources to be used for communication with stations, wherein, the trigger frame includes information in which identification information identifying another access point and information indicating frequency resources to be allocated to the other access point are associated with each other, and the trigger frame allocates a transmission opportunity using different frequency resources to each of the one or more other cooperative access points.

11. A program for causing a computer to execute the control method for an access point device according to claim 10.

Images