Access point device, control method thereof, and computer readable storage medium

Abstract

Access point devices send trigger frames to other access point devices to initiate communication compliant with the IEEE 802.11 standard series between other access point devices and station devices, wherein the trigger frame includes information indicating the frequency channel to be used for communication.

Description

Technical Field

[0001] This invention relates to a resource control technology for wireless communication. Background Technology

[0002] With the increasing volume of data to be communicated in recent years, communication technologies such as Wireless Local Area Networks (LANs) have been developed. The Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard series is known as the primary communication standard for wireless LANs. The IEEE 802.11 standard series includes IEEE 802.11a / b / g / n / ac / ax standards. For example, in the latest IEEE 802.11ax standard, a technique for achieving a peak throughput of up to 9.6 gigabits per second (Gbps) and improving communication speed under congestion by using Orthogonal Frequency-Division Multiple Access (OFDMA) has been standardized (see Patent Document 1). Note that OFDMA is an abbreviation for Orthogonal Frequency Division Multiple Access.

[0003] On the other hand, to further improve throughput, frequency utilization efficiency, and communication latency, a task force was formed following IEEE 802.11ax to develop a standard known as IEEE 802.11be. Within the IEEE 802.11be standard, a technique has been developed to allow multiple access points (hereinafter sometimes referred to as "APs") to cooperate in operating with each other for data communication with stations (hereinafter sometimes referred to as "STAs"). Multiple APs cooperating with each other to communicate with STAs allows for improved communication performance by increasing communication rates and suppressing interference between radio signals transmitted separately from multiple APs and STAs.

[0004] Citation List

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2018-050133 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] This invention provides a technique for further improving communication performance when multiple access points communicate with a station simultaneously.

[0009] Solution for solving the problem

[0010] This invention provides a technique for appropriately performing control communications for comprehensive control of communications in multiple wireless links.

[0011] According to one aspect of the present invention, an access point device is provided, the access point device comprising: a transmitting unit configured to transmit a trigger frame to other access point devices, wherein the trigger frame is used to trigger communication compliant with the IEEE 802.11 series of standards between the other access point devices and station devices, the trigger frame including information indicating a frequency channel to be used for the communication.

[0012] The effects of the invention

[0013] According to the present invention, communication performance can be further improved when multiple access points communicate with the station simultaneously.

[0014] Other features and advantages of the invention will become apparent from the following description taken in conjunction with the accompanying drawings. Note that throughout the drawings, the same reference numerals denote the same or similar components. Attached Figure Description

[0015] Embodiments of the invention are illustrated in conjunction with the accompanying drawings, which are included in and form part of this specification, and together with the description serve to explain the principles of the invention.

[0016] Figure 1 This is a diagram illustrating an example of network configuration;

[0017] Figure 2 This is a block diagram illustrating an example of the hardware layout of a communication device;

[0018] Figure 3 This is a block diagram illustrating an example of the functional layout of a communication device;

[0019] Figure 4A This is a flowchart illustrating a first example of the processing procedure performed by the main AP;

[0020] Figure 4B This is a flowchart illustrating a first example of the processing procedure performed by the main AP;

[0021] Figure 5A This is a flowchart illustrating a first example of a processing procedure performed from the AP;

[0022] Figure 5B This is a flowchart illustrating a first example of a processing procedure performed from the AP;

[0023] Figure 6 This is a sequence diagram illustrating an example of the processing procedure when data is sent to a STA;

[0024] Figure 7A This is a flowchart illustrating a second example of the processing procedure performed by the main AP;

[0025] Figure 7BThis is a flowchart illustrating a second example of the processing procedure performed by the main AP;

[0026] Figure 8A This is a flowchart illustrating a second example of a processing procedure performed from the AP;

[0027] Figure 8B This is a flowchart illustrating a second example of a processing procedure performed from the AP;

[0028] Figure 9 This is a sequence diagram illustrating an example of the processing procedure when data is received from a STA;

[0029] Figure 10 This is a sequence diagram illustrating an example of the processing procedure when data is sent to multiple STAs;

[0030] Figure 11 This is a sequence diagram illustrating an example of the processing procedure when data is received from multiple STAs;

[0031] Figure 12 This is a diagram illustrating a first example of the structure of a trigger frame; and

[0032] Figure 13 This is a diagram showing a second example of the structure of a trigger frame. Detailed Implementation

[0033] 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 scope of the claimed invention. Several features are described in the embodiments, but it is not a limitation requiring all such features, and multiple such features can be appropriately combined. Furthermore, in the drawings, the same reference numerals are given the same or similar configuration, and redundant descriptions are omitted.

[0034] (Network Configuration)

[0035] Figure 1An example configuration of a network according to an embodiment is shown. Networks 101 to 103 are each formed by access points (e.g., at least one AP among APs 100 and 104 to 106) conforming to the IEEE 802.11be (EHT) standard. Note that IEEE is an acronym for the Institute of Electrical and Electronics Engineers. EHT is an acronym for Extremely High Throughput. Stations (STAs 107 to 109) conforming to the IEEE 802.11be standard join at least one of these networks to wirelessly communicate with at least one AP among APs 104 to 106. Note that the following description assumes the networks are wireless LANs conforming to the IEEE 802.11 standard family. However, the following discussion applies to various wireless communication networks with the same communication capabilities. In other words, AP and STA are examples of communication devices in various wireless communication systems, and are not limited to APs or STAs in wireless LANs conforming to the IEEE 802.11 standard family. Unless there is a specific need to distinguish between APs and STAs, these devices will sometimes be referred to collectively as "communication devices" in the following text.

[0036] Note that it is assumed that each communication device conforms to at least the IEEE 802.11be standard. In addition, each communication device may support legacy standards defined prior to the IEEE 802.11be standard. For example, each communication device may support at least one of the IEEE 802.11a / b / g / n / ac / ax standards. Furthermore, in addition to the IEEE 802.11 standard family, each communication device may support standards such as... Other communication standards include Bluetooth, NFC, UWB, ZigBee, and MBOA. Note that UWB stands for Ultra Wide Band, and MBOA stands for Multi Band OFDM Alliance. Additionally, NFC stands for Near Field Communication. UWB includes Wireless USB, Wireless 1394, and WiNET. Furthermore, individual communication devices can support wired communication standards such as wired LAN.

[0037] In this embodiment, each AP can be, for example, a wireless LAN router or a personal computer (PC), but is not limited to these. APs 104 to 106 can each be an information processing device, such as a radio chip, capable of performing wireless communication compliant with the IEEE 802.11be standard. STAs 107 to 109 can each be, for example, a camera, tablet computer, smartphone, PC, mobile phone, or camcorder, but are not limited to these. STAs 107 to 109 can each be an information processing device, such as a radio chip, capable of performing wireless communication compliant with the IEEE 802.11be standard. Furthermore, Figure 1 The example shown includes a network configuration with four APs and three STAs, but the number of APs, the number of STAs, and the placement of the APs and STAs are not limited to this example.

[0038] exist Figure 1 In the example shown, STAs 107 and 108 are each within the communication range of networks 101, 102, and 103, and are connected to at least one of these networks to perform communication. STA 109 is within the communication range of networks 101 and 103, and is connected to at least one of these networks to perform communication. Note that in Figure 1 In this network, network 101 is formed by AP 104, network 102 is formed by AP 105, and network 103 is formed by AP 106. As will be described later, it is assumed that AP 100 is used as a control device (master AP) to communicate with APs 104 to 106 and to enable APs 104 to 106 to communicate with STAs.

[0039] Note that if APs 104 to 106 form separate networks, their BSSIDs will be different from each other. Note that BSSID is an abbreviation for Basic Service Set Identifier and is an identifier used to identify the network. APs 100 and 104 to 106 each set a common SSID as the SSID indicated in their respective networks. Note that SSID is an abbreviation for Service Set Identifier and is an identifier used to identify the access point. In this embodiment, even if APs 100 and 104 to 106 each establish multiple connections, they share a single SSID.

[0040] Each communication device can perform communication by multiplexing signals from multiple users by executing Orthogonal Frequency Division Multiple Access (OFDMA) communication conforming to the IEEE 802.11be standard. Such communication, performed by multiplexing signals from multiple users, is called multi-user (MU) communication. In OFDMA communication, resource units (RUs), which are frequency resources obtained by dividing the system bandwidth into predetermined sizes, are allocated to each STA without overlapping. This prevents interference between the signals of different STAs or suppresses interference, and the AP can communicate simultaneously with multiple STAs within the system frequency band. For example, AP 104 can simultaneously communicate with STAs 107 to 109 by allocating non-overlapping RUs to these STAs.

[0041] Individual communication devices can perform communication using bandwidths of 20MHz, 40MHz, 80MHz, 160MHz, and 320MHz. Individual communication devices can also use bandwidths different from the above, such as 240MHz or 4MHz. Note that in the IEEE 802.11 standard series, the bandwidth of each frequency channel is defined as 20MHz. On the other hand, by combining adjacent frequency channels, a bandwidth of 40MHz or greater can be used in a single frequency channel. Individual communication devices can perform communication in their respective frequency channels within the 2.4GHz, 5GHz, and 6GHz frequency bands, and can also use frequency channels in frequency bands such as the 60GHz band.

[0042] Note that communication devices can simultaneously use channels in multiple frequency bands to perform communication through multi-link communication. For example, AP 105 can establish a first link 110 with STA 107 via a first frequency channel in the 2.4 GHz band, and can establish a second link 111 with STA 107 via a second frequency channel in the 5 GHz band, and can perform communication through these two links. In this case, AP 105 maintains the first link 110 via the first frequency channel while maintaining the second link 111 via the second frequency channel. If multi-link communication is performed, AP 105 and STA 107 each allocate a data segment and send the allocated data to the other device via multiple links. Therefore, AP 105 can establish wireless links with STA 107 via multiple frequency channels, thereby improving the throughput of communication with STA 107. Note that in this embodiment, link 110 is established in the 20 MHz bandwidth of channel 5 in the 2.4 GHz band, and the link number of link 110 is 1. Link 111 is established in the 40MHz bandwidth of channel 36 in the 5GHz band, and the link number of link 111 is 2. In addition, link 112 is established between AP 104 and STA 107 in the 40MHz bandwidth of channel 36 in the 5GHz band.

[0043] Note that in addition to the first link 110 and the second link 111, AP 105 and STA 107 can establish links, thus establishing three or more links to perform communication. For example, in addition to the first link 110 and the second link 111 mentioned above, AP 105 and STA 107 can use a frequency channel in the 6 GHz band to establish a third link. Multiple links using multiple different channels included in the same frequency band can be established. For example, AP 105 and STA 107 can use channel 1 in the 2.4 GHz band to establish the first link 110, and use channel 5 in the 2.4 GHz band to establish the second link 111. Note that links in the same frequency band and links in different frequency bands can be mixed. For example, AP 105 and STA 107 can use channels 1 and 5 in the 2.4 GHz band to establish the first link 110 and the second link 111, respectively, and also use channel 36 in the 5 GHz band to establish the third link. If AP 105 and STA 107 establish multiple connections across multiple frequency bands, communication can be performed in other frequency bands even if a given frequency band is congested, thus preventing a decrease in communication throughput. The multiple links established in multi-link communication use at least different frequency channels. The spacing between the frequency channels of the multiple links established in multi-link communication is set to be at least greater than 20 MHz.

[0044] Each communication device can be configured to perform Multiple-Input Multiple-Output (MIMO) communication. For example, both the transmitting and receiving communication devices include multiple antennas, and the transmitting device uses the same frequency channel to transmit different signals from the multiple antennas. The receiving device then simultaneously receives all signals arriving at the multiple receiving antennas, separates the streams, and decodes the signals. Therefore, multiple data streams are transmitted / received simultaneously using the same frequency channel within the same time interval. In this way, more data can be transmitted / received during a period of equal length using MIMO communication. Furthermore, when performing multi-link communication, MIMO communication can be performed only on some of the established links. For example, distributed MIMO technology based on MIMO can be used. In distributed MIMO, in an environment with multiple APs and multiple STAs, multiple APs share information related to communication status or device status and communicate at the same timing. When multiple APs cooperate to perform communication, the number of spatial streams can be increased compared to the case where a single AP performs communication, thereby improving throughput. Note that cooperative beamforming based on beamforming technology can be used, where beamforming is used for beam control, for example, using multiple antennas to increase antenna gain in a given direction and decrease antenna gain in other directions. In cooperative beamforming, if an AP sends data to a STA belonging to a Basic Service Set (BSS), the antenna gain in the direction of the STA increases, and the antenna gain in the direction of a STA belonging to another AP's BSS decreases. For example, the AP can use one of a pre-prepared antenna pattern, or it can calculate the antenna pattern each time based on the STA's direction. In this way, antenna patterns are set and scheduled in multiple APs based on environmental information such as the location of the STA, thereby reducing the impact of interference occurring in the BSS. This communication technique in which multiple APs cooperate to operate is called multi-AP communication. In multi-AP communication, APs can be classified as a master AP (hereinafter sometimes referred to as "MAP") for managing all APs and slave APs (hereinafter sometimes referred to as "SAP") for operating under the management of the MAP.

[0045] In this embodiment, AP 100 is an AP used as a MAP and communicates with APs 104 to 106. Alternatively, APs 104 to 106 can operate as SAPs communicating with STAs under the control of the MAP. In one example, AP 100 is configured to send communication instructions to each of the APs 104 to 106, and APs 104 to 106 are configured to communicate with STAs 107 to 109 based on these instructions.

[0046] In multi-AP communication, communication performance can be further improved by adjusting radio resources when SAPs communicate with STAs. That is, if the frequency channels to be used for communication between each SAP and STA are determined without any adjustments, multiple SAPs could use the same frequency channel, potentially causing interference between the signals transmitted by the SAPs. Similarly, signals transmitted from one or more STAs to multiple SAPs can interfere with each other. Therefore, in this embodiment, by using different frequency channels for each SAP, interference between signals is more reliably avoided, thereby improving communication performance. Accordingly, for example, when multiple SAPs communicate with different STAs using cooperative beamforming, even if there are STAs whose interference cannot be avoided by beamforming, interference can be avoided by using different frequency channels. Furthermore, if a STA communicates with multiple SAPs, interference between the signals transmitted / received by the SAPs can be prevented by using different frequency channels. If a STA establishes multiple links using different frequency channels with a SAP to perform communication, communication can be conducted in a way that reduces interference by having the SAP determine the link to use based on the external environment. On the other hand, SAPs cannot know in advance the external environment, such as frequency channels used by other SAPs. Therefore, in this embodiment, the MAP (AP 100) notifies the SAPs joining the multi-AP communication of the frequency channels and links to be used for communication indication. For example, the MAP may include information indicating the frequency channels and links to be used by each SAP in a trigger frame used to trigger data communication, wherein the trigger frame is sent to each of the multiple SAPs that want to send or receive data simultaneously (at the same time) when data communication is performed with the STA. Therefore, when performing data communication in multi-AP communication, using appropriate frequency channels / links can prevent interference in the communication performed by the individual SAPs in the multiple SAPs and further improve the performance of multi-AP communication.

[0047] The following will describe an example of the arrangement of the various communication devices used to perform this processing and the processing procedure.

[0048] (Layout of communication equipment)

[0049] Figure 2 An example of the hardware arrangement of communication devices (AP and STA) according to this embodiment is shown. Each communication device includes, for example, a storage unit 201, a control unit 202, a function unit 203, an input unit 204, an output unit 205, a communication unit 206, and antennas 207 to 209.

[0050] Storage unit 201 is formed by either ROM or RAM, and stores programs configured to perform various operations described later, as well as various information such as communication parameters for wireless communication. Note that ROM is an abbreviation for Read Only Memory, and RAM is an abbreviation for Random Access Memory. Storage unit 201 can be used not only with memory such as ROM or RAM, but also with storage media such as floppy disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, or DVDs. Storage unit 201 may include storage devices such as multiple memories.

[0051] The control unit 202 is formed, for example, by at least one processor such as a CPU or MPU, an application-specific integrated circuit (ASIC), a digital signal processor (DSP), or a field-programmable gate array (FPGA). Here, CPU is an abbreviation for Central Processing Unit, and MPU is an abbreviation for Micro Processing Unit. The control unit 202 executes the program stored in the storage unit 201, thereby controlling the entire device. Note that the control unit 202 can control the entire device through the cooperation of the program stored in the storage unit 201 and the operating system (OS). The control unit 202 may include multiple processors such as a multi-core processor, and the entire AP 100 is controlled by multiple processors. The control unit 202 generates the data and signals (radio frames) to be transmitted in communication with other communication devices.

[0052] Furthermore, the control unit 202 controls the functional unit 203 and performs predetermined processes such as imaging, printing, or projection. The functional unit 203 is hardware used by the device to perform the predetermined processes. For example, if the device is a camera, the functional unit 203 is an imaging unit and performs imaging processing. For example, if the device is a printer, the functional unit 203 is a printing unit and performs printing processing. Furthermore, for example, if the device is a projector, the functional unit 203 is a projection unit and performs projection processing. The data to be processed by the functional unit 203 may be data stored in the storage unit 201, or data communicated with other APs or STAs via the communication unit 206, which will be described later.

[0053] Input unit 204 receives various operations from the user. Output unit 205 provides various outputs to the user. Here, the outputs of output unit 205 include at least one of, for example, display on a screen, audio output from a speaker, and vibration output. Note that input unit 204 and output unit 205 can both be implemented as a single module, such as a touch panel. Note that input unit 204 and output unit 205 can each be included in the communication device, or can be configured to be connected externally to the communication device.

[0054] Communication unit 206 controls wireless communication or controls IP communication conforming to the IEEE 802.11 standard family. Communication unit 206 is a so-called radio chip, which may itself include one or more processors or memories. In this embodiment, communication unit 206 can perform processing conforming to at least the IEEE 802.11be standard. Additionally, communication unit 206 controls antennas 207 to 209 and transmits / receives radio signals for wireless communication. Communication devices communicate with other communication devices via communication unit 206, providing content such as image data, document data, or video data. Antennas 207 to 209 are each configured to transmit / receive signals in at least one frequency band, such as a sub-GHz band, a 2.4GHz band, a 5GHz band, and a 6GHz band. Note that there is no particular limitation on the frequency bands (and combinations thereof) to be processed by antennas 207 to 209. Antennas 207 to 209 may each be a single antenna, or may comprise a set of two or more antennas for multiple-input multiple-output (MIMO) transmission / reception. Antennas 207 to 209 may include two or more antennas (two or more sets of antennas) applicable to different frequency bands. The arrangement of multiple antennas 207 to 209 in a communication device is merely an example, and a communication device may include only one antenna. Note that communication unit 206 and antennas 207 to 209 may be integrated, or they may be prepared separately and connected. Furthermore, communication unit 206 may be prepared for, for example, individual antennas and individual frequencies. For example, a first communication unit combined with antenna 207, a second communication unit combined with antenna 208, and a third communication unit combined with antenna 209 may be prepared.

[0055] Note that if the communication device supports NFC or Bluetooth standards in addition to the IEEE 802.11 standard family, the communication unit 206 can control wireless communication conforming to these communication standards. If the communication device can perform wireless communication conforming to each of the multiple communication standards, the communication device may include a communication unit and an antenna supporting each communication standard.

[0056] Figure 3This is a block diagram illustrating the functional arrangement of the communication devices (AP and STA) according to this embodiment. Each communication device includes, for example, a first wireless LAN control unit 301, a frame generation unit 302, a frame analysis unit 303, a channel allocation unit 304, a UI control unit 305, a storage control unit 306, a second wireless LAN control unit 307, and a third wireless LAN control unit 308. Note that an example of a communication device including three wireless LAN control units will be described, but the number of wireless LAN control units is not limited to three, and can be one, two, four, or more than four.

[0057] Three wireless LAN control units each control wireless LAN communication implemented by antennas and circuitry configured to transmit / receive radio signals from other wireless LAN communication devices. Each wireless LAN control unit can be implemented, for example, by a computer program for controlling wireless LAN communication. Each wireless LAN control unit performs wireless LAN communication control based on frames generated by frame generation unit 302, according to the IEEE 802.11 standard series. Frame generation unit 302 generates a wireless control frame to be transmitted by one of the wireless LAN control units. The wireless control frame generated by frame generation unit 302 can be subject to settings stored in storage control unit 306. These restrictions and the content of the wireless control frame can be changed through user settings from UI control unit 305.

[0058] Frame analysis unit 303 interprets the radio frames received by each wireless LAN control unit and reflects the content on each wireless LAN control unit. Other wireless LAN control units that have not yet received frames can be controlled via frame analysis unit 303 using the wireless control frames received by some wireless LAN control units. When communicating with a communication partner (e.g., AP 104 to 106 if the communication device is AP 100), channel allocation unit 304 allocates a channel for communication. Furthermore, when instructing the communication partner (AP 104 to 106) to communicate with other devices (e.g., STA 107 to 109), channel allocation unit 304 allocates a channel for communication. For example, AP 105 and STA 107 communicate with each other using the allocated channel determined by channel allocation unit 304 of AP 100 or a sub-channel defined within the channel.

[0059] The UI control unit 305 controls the hardware associated with a user interface (not shown) for accepting user operations on the communication device, such as touch panels and buttons. The UI control unit 305 is implemented, for example, by a program for controlling the hardware. Note that the UI control unit 305 also has the function of presenting information to the user, such as displays of images or audio output. The storage control unit 306 performs control to store data and programs used to operate the communication device in ROM and RAM.

[0060] (Processing procedure)

[0061] The communication flow according to this embodiment will then be described using some examples. Note that in the following processing examples, as described above, AP 100 can operate as a MAP and APs 104 to 106 can operate as SAPs. AP 100 performs control to enable APs 104 to 106 and STAs 107 to 109 to communicate with each other.

[0062] <Data Transmission>

[0063] Reference Figure 4A and Figure 4B This describes the scenario where AP 100 transmits data to STA 107 via APs 104 and 105. For example, if there is data to be transmitted from AP 100 to STA 107, then the process begins... Figure 4A and Figure 4B The process is shown below. Note that when establishing connections between AP 100 and APs 104 and 105, and between APs 104 and 105 and STA 107, you can begin... Figure 4A and Figure 4B The process is shown in the diagram. Then, when data is sent from AP 100 to STA 107, the process can begin from the process in step S406, which will be described later.

[0064] exist Figure 4A and Figure 4BIn the illustrated process, AP 100 first sends (broadcasts) an information acquisition request to obtain information about neighboring APs (step S401). The information acquisition request may include information (e.g., an identifier) ​​indicating that a neighboring AP with the same SSID will return a response if it receives the request. AP 100 obtains information about the neighboring AP by receiving a response to the information acquisition request from the neighboring AP (step S402). The information obtained in step S402 may include, for example, information about the BSSID of the network formed by the AP, information about the frequency channels available to the AP, and information indicating whether the AP supports multi-link communication. The information obtained in step S402 may include the Received Signal Strength Indication (RSSI) and Signal-to-Noise Ratio (SNR) of the radio waves transmitted from AP 100, the AP's IP address and MAC address, and values ​​for HT / VHT / HE / EHT capabilities. The information obtained in step S402 may include information related to the transmission rate of transmitted / received data, the maximum allowable packet size, the maximum number of connectable STAs, the number of currently connected STAs, and the types of security standards supported by the AP itself or the currently connected STAs. In addition, the information obtained in step S402 may include information related to the channel used by the currently connected STA and the data transmission / reception speed from minimum to maximum speed.

[0065] AP 100 forms groups for association with neighboring APs based on the information obtained in step S402 (step S403). At this time, the MAP (AP 100) issues an ID to identify the SAP (at least one of APs 104, 105, and 106). This ID is processed to be equivalent to the AID (Association ID) assigned to the currently connected STA. For example, if STA 109 is connected to AP 100, AP 100 assigns AID=1 to STA 109. In this state, if APs 104 to 106 are SAPs, AID=2, AID=3, and AID=4 are assigned to APs 104, 105, and 106, respectively. Note that the method of assigning IDs to identify individual APs is not limited to this. For example, in addition to AIDs, AP IDs for association can also be assigned. In this case, for example, AP IDs=1 to 3 are assigned to APs 104 to 106, respectively. Note that if an AP ID is assigned, the range of the AP ID value is set to 1 to 2007. For example, when AP 100 decides to form a group with SAP in step S403, the value of the ID (AID or APID) assigned to each AP is sent from AP 100 to the slave AP (at least one of AP 104 to 106). Note that this notification can occur between steps S405 and S406, which will be described later. This allows the slave AP to determine the channel and resource unit assigned to its own device in the trigger frame to be sent later. MAP (AP 100) can notify each SAP of the ID assigned using, for example, a dedicated frame or an existing frame. Note that AP IDs can be assigned at different times, etc. For example, in step S407, which will be described later, when an AP asserts joining multi-AP communication, an ID can be assigned to the AP, and the ID can be notified to the AP in step S408.

[0066] Next, AP 100 sends an information acquisition request to the APs included in the formed group, requesting information about the currently connected STAs (step S404). This request may include an identifier indicating the information of the STAs connected to each AP. The frame does not need to be a radio frame to be transmitted via a wireless line, and may be a wired frame to be transmitted via a wired line. Then, AP 100 receives information about the STAs connected to the AP from the AP at the requested transmission destination, as a response to the information acquisition request (step S405). This information may include information related to the STA's MAC address, the channel and bandwidth used by the STA, whether the STA supports multi-link communication, and the Received Signal Strength Indication (RSSI) and Signal-to-Noise Ratio (SNR) when communicating with the STA. This information may also include information related to the STA's IP address, whether it can operate in power-saving mode, the TIM value indicating the beacon signal reception frequency, the HT / VHT / HE / EHT capability value, and the transmission rate of transmitted / received data from minimum to maximum rate. This information may include information such as the AID assigned to the STA by the AP, the maximum allowed packet size, and the types of security standards supported by the currently connected STA. Note that AP 100 can simultaneously send the information acquisition request in steps S401 and S404, and simultaneously acquire multiple pieces of information to be received in steps S402 and S405.

[0067] Subsequently, AP 100 sends a frame to confirm whether each SAP can proceed with the next data transmission (i.e., whether each SAP can join the data transmission via multi-AP communication) (step S406). This frame may include information indicating the amount of data to be transmitted and the time for transmission. AP 100 receives responses from each SAP to the query in step S406 (step S407). This response signal may include information indicating whether the SAP can join the data transmission. Note that if the SAP can conditionally join the data transmission, the response signal may include information indicating the conditions for joining. The conditions for joining may include information specifying the channels and bandwidth that can be used for data transmission. Based on the results received in step S407, AP 100 determines which SAP will be used for data transmission via multi-AP communication (step S408). At this point, AP 100 may send a frame to notify the SAP that it has been selected as the AP for data transmission. This embodiment assumes that APs 104 and 105 join the multi-AP communication. Subsequently, AP 100 determines the frequency channel to be used by each SAP (step S409). If SAP uses OFDMA for communication, AP 100 can decide which RU to use. Note that the decision on frequency channels, etc., in step S409 can be performed simultaneously (at the same time) with the decision on which SAP to join multi-AP communication in step S408.

[0068] After determining which SAPs will join the multi-AP communication and the frequency channels to be used by each SAP, AP 100 determines whether data can be sent in this state (step S410). For example, if no SAP can join the multi-AP communication, AP 100 determines that it is impossible to send data from the SAP to the STA. Then, if AP 100 determines that it is impossible to send data ("No" in step S410), it changes the data volume and conditions to restart the process from the processing in step S406. Note that in this case, AP 100 can directly send data to the STA. If a response is received from the SAP in step S407, AP 100 can perform this determination (the determination corresponding to step S410). The determination of the frequency channels, etc. in step S409 can be performed before the query in step S406 regarding whether each AP can join the multi-AP communication. In this case, the information sent from the SAP in step S407 can only indicate whether each AP can join. This allows AP 100 to determine the allocation of a new channel when data transmission is impossible, and to send a frame to SAP again to confirm whether SAP can join. If it is determined that data transmission is possible ("Yes" in step S410), AP 100 sends data to SAP destined for the STA (step S411). Then, AP 100 sends a trigger frame to SAP to cause SAP to send data to the STA (step S412). In this embodiment, AP 100 sends the trigger frame to APs 104 and 105.

[0069] Figure 12 This shows an example of a trigger frame sent here. Figure 12 The fields / subfields shown conform to the format defined in the IEEE 802.11ax standard. That is, the trigger frame includes a frame control field 1201, a duration field 1202, an RA field 1203, a TA field 1204, a common information field 1205, a user information field 1206, a padding field 1207, and an FCS field 1208. The common information field 1205 includes a trigger type subfield 1209 and a length subfield 1210. The length subfield 1210 indicates a communication period shared by all SAPs. This communication period corresponds to the amount of data that can be sent / received by each SAP. On the other hand, the trigger type subfield 1209 consists of 4 bits and specifies the trigger type using this trigger frame. Table 1 below illustrates the correspondence between the values ​​of the trigger type subfield 1209 and the trigger types.

[0070] [Table 1]

[0071]

[0072]

[0073] If the value of the trigger type subfield 1209 is set to "9", it indicates that the trigger frame indicates data transmission via multi-AP communication.

[0074] User information field 1206 is a field prepared for each SAP. In the trigger frame, the number of user information fields 1206 equal to the number of SAPs is concatenated and stored. User information field 1206 includes, for example, an AP ID subfield 1211, a channel subfield 1212, and a RU allocation subfield 1213. Table 2 below shows the correspondence between the values ​​of the AP ID subfield 1211 included in user information field 1206 and the meanings indicated by those values.

[0075] [Table 2]

[0076]

[0077]

[0078] In this embodiment, the AP ID assigned to SAP by MAP is stored as the value of the AP ID subfield 1211. Note that APID can be considered equivalent to AID. If the value of AP ID subfield 1211 falls within the range of "1" to "2007", then the value is the value of the assigned AP ID. As shown in Table 2, the remaining values ​​are interpreted as information different from the AP ID.

[0079] The channel subfield 1212 included in the user information field 1206 contains information about the frequency channel that the SAP will use to transmit data. This information stores a value corresponding, for example, to the channel number defined in the IEEE 802.11 standard series. For example, if channel 6 in the 2.4 GHz band is used to transmit data, the value of channel subfield 1212 is set to "6". Note that the link number of the link to be used in multiple links established between the SAP and STA can be stored as this value. Both link number information and frequency channel information can be included in channel subfield 1212. For example, if data is to be transmitted from AP 104 to STA 107 in link 1, this value can be set to "1". Note that when the SAP and STA are connected, the link number is assigned by the SAP and given to the STA. Alternatively, the MAP can assign the link number and notify the SAP of the link number. Channel subfield 1212 is prepared as an 8-bit subfield. The number of bits to be prepared is not limited to this. For example, if a link number is used to allocate a channel, the channel subfield 1212 can be prepared as a 3-bit or 4-bit subfield. Note that if a link number is used here, in step S402 or S405, the SAP can send information to the AP 100 to associate the link number of a specific link with the specific frequency channel traversed by the link connecting that specific link. This allows the AP 100 to appropriately assign the channel that the SAP will use to transmit data. The value stored in the channel subfield 1212 can be a value associated with a frequency band. For example, the 2.4 GHz band, the 5 GHz band, and the 6 GHz band are pre-associated with "1", "2", and "3", respectively, and then if a frequency channel is used in the 2.4 GHz band, the value of the channel subfield 1212 can be set to "1". In this case, the channel subfield 1212 can be prepared as, for example, a 2-bit subfield.

[0080] Information specifying the tone size and RU for the corresponding SAP is stored in the RU allocation subfield 1213 included in the user information field 1206. The RU allocation subfield 1213 can be prepared as an 8-bit subfield. Table 3 shows an example of the correspondence between the values ​​stored in the RU allocation subfield 1213 and the allocated RUs.

[0081] [Table 3]

[0082]

[0083]

[0084] For example, if the bandwidth of a frequency channel is 20MHz and the value of RU allocation subfield 1213 is "38", then 52 is allocated as the frequency modulation size of the subchannel, and a second RU (RU 2) is allocated to SAP. According to this representation, RUs can be flexibly allocated even if the bandwidth is different for each frequency channel.

[0085] Note that multiple RUs can be assigned to the same SAP. In this case, user information fields 1206 are set, where the number of user information fields 1206 equals the number of assigned RUs, and in each user information field 1206, the same value is stored in the AP ID subfield 1211, and different values ​​are set in at least one of the channel subfield 1212 and the RU allocation subfield 1213. To assign multiple RUs to one SAP, other representations can be used. For example, a cascading subfield is prepared after the AP ID subfield 1211. Then, if this bit is set to "1", the cascading subfield, channel subfield, and RU allocation subfield are arranged again after the RU allocation subfield. On the other hand, if the bit of the cascading subfield is set to "0", other subfields different from the cascading subfield, channel subfield, and RU allocation subfield are arranged after the RU allocation subfield. That is, if the cascading subfield is set to "1", other channel subfields and other RU allocation subfields are set immediately after the channel subfield and RU allocation subfield set after the cascading subfield. On the other hand, if the cascading subfield is set to "0", then no other channel subfields or RU allocation subfields are set immediately after the channel subfield and RU allocation subfield set after the cascading subfield. Note that the cascading subfield can be placed after the channel subfield or RU allocation subfield. According to this representation, if multiple RUs are assigned to a single SAP, the RU allocation can be specified using a smaller number of bit strings.

[0086] Note that the representation methods described above are merely examples, and other representation methods can be used. In this embodiment, since the frequency channels are represented simultaneously, the bandwidth used can be limited to 20MHz units. In this case, since the RU allocation subfield only needs to specify that the "Used Bandwidth" in Table 3 includes 16 RU allocations of 20MHz, a size of 4 bits is sufficient. By limiting the bandwidth of the frequency channels to 20MHz, the above-described cascaded subfields can be used. Using the above subfields (at least one of the channel subfield 1212 and the RU allocation subfield 1213), the SAP can determine the frequency channel to be used to send data to the STA.

[0087] Furthermore, for example, RUs can be predefined to be allocated in ascending order of frequency channels, and the RUs to be allocated can be specified based on this definition. For example, if the size of the RUs to be allocated in channel 1 of the 2.4 GHz band and channel 36 of the 5 GHz band, each with a bandwidth of 40 MHz, is limited to 26, then values ​​0 to 17 are allocated to the first RU to the 18th RU available in channel 1 of the 2.4 GHz band. Then, values ​​18 to 36 are allocated to the 19th RU to the 37th RU available in channel 36 of the 5 GHz band. For example, if the value "20" is stored in the RU allocation subfield, then the 21st RU is specified in channel 36 of the 5 GHz band. Note that the frame does not need to include the RU allocation subfield 1213. For example, MAP can perform management up to link allocation, and SAP can manage the RU allocation in the allocated links. In this case, in the trigger frame sent in step S412, only the frequency channel or link number needs to be specified, and the RU allocation does not need to be specified. When the SAP receives a trigger frame, it can choose whether to send data to the STA using the entire band of a specified frequency channel, or to send data by allocating a portion of that band to other STAs. By pre-determining whether to use the entire band of a specified frequency channel for data communication, the SAP does not need to include circuitry for performing processes such as allocating a portion of the frequency band, thus simplifying the SAP's layout.

[0088] Note that the trigger frame can have Figure 13 The form shown is used. That is, in addition to the AP ID subfield 1211, a subfield (AID subfield 1301) can be prepared to specify the AID, which indicates the STA with which the SAP wants to communicate. In this case, upon receiving a trigger frame, the SAP can identify the STA to which the data is to be sent. This allows for flexible configuration of the data communication counterpart, and it is not necessary to re-process from step S406 every time data communication is performed. In other words, if communication is performed with a different STA as the communication counterpart, only the processes in steps S411 to S415 need to be repeated, without having to return to step S406 each time.

[0089] Return to reference Figure 4BAP 100 waits to receive a notification from SAP indicating whether SAP can send data to STA (step S413). If there is an SAP that cannot send data correctly (No in step S413), AP 100 returns to step S406 to restart processing from the AP selection. If AP 100 receives a data transmission success notification from each SAP (Yes in step S413), AP 100 sends a frame to confirm whether the data was correctly sent to STA (step S414). Then, based on the frame received as a response to the frame sent in step S414, AP 100 confirms whether all acknowledgments (ACKs) for the data sent from SAP to STA have been returned (step S415). The ACK to be confirmed is an ACK for data that can be sent from SAP to the target STA. Therefore, AP 100 can determine that the data has arrived at STA correctly. Note that throughout this embodiment, the ACK can be a block ACK. If AP 100 does not receive an ACK (No in step S415), AP 100 can re-process from step S406, taking into account the transmission of data from other APs. Note that in this case, AP 100 can repeat processing from the transmission of the trigger frame for retransmission of data (step S412). AP 100 can standby until AP 100 confirms that all data has been transmitted correctly. If SAP can correctly transmit data to STA without AP 100 sending a frame in step S414, it can send an ACK to AP 100. That is, step S414 can be omitted. In this case, AP 100 waits for an ACK for a predetermined period after the transmission of the trigger frame. If no ACKs for the transmitted data are received within the predetermined period, AP 100 can re-process from step S406. In this case, AP 100 can adjust the SAP selection in step S408, taking into account the use of the channel and the SAP that can correctly transmit data to the STA. For example, if only some SAPs have successfully transmitted data, AP 100 can select the SAPs that have successfully transmitted data. Furthermore, if data transmission is successful only on a given frequency channel, AP 100 can allocate only that frequency channel in step S409.

[0090] If AP 100 confirms that the data transmission was successful ("Yes" in step S415), then AP 100 checks whether there is any data remaining to be transmitted (step S416). If there is data remaining to be transmitted ("Yes" in step S416), then AP 100 selects the frequency channel and AP to be used to transmit the remaining data, taking into account information related to the transmission result (such as the SAP and frequency channel that have successfully transmitted data) (step S417). For example, if the process is executed again from step S406, AP 100 can send a frame to the AP that has successfully transmitted data last time to confirm whether the AP can join. In this case, in the above AP selection method, a method that considers the communication result can be used, or the AP can be selected solely based on the communication result, regardless of the above AP selection method. If it is determined that there is no data remaining to be transmitted ("No" in step S416), then AP 100 ends the process.

[0091] Then, refer to Figure 5A and Figure 5B This describes an example of the processing procedure when SAPs (AP 104 and 105) cooperate with each other to send data to STA (STA 107). Note that SAPs (AP 104 and 105) initiate the following process in response to receiving an information acquisition request from a neighboring AP from AP 100.

[0092] If AP 104 and 105 each receive an information acquisition request from AP 100 requesting information about neighboring APs (step S501), then AP 104 and 105 each send a response to the request to AP 100 (step S502). If AP 104 and 105 each receive an information acquisition request from AP 100 requesting information about currently connected STAs (step S503), then AP 104 and 105 each send a response including information about currently connected STAs (step S504). Note that the information sent / received in steps S501 to S504 is as described in the reference. Figure 4A The description will be omitted. Next, AP104 and 105 each receive a frame from AP 100 to confirm whether to join the data transmission in preparation for data transmission to STA 107 (step S505). Upon receiving the frame, AP104 and 105 each decide whether to join the data transmission based on their own current communication state (step S506).

[0093] If APs 104 and 105 do not participate in data transmission ("No" in step S506), then APs 104 and 105 each send a frame to AP 100 indicating that they have not participated in data communication (step S507). Note that in this case, APs 104 and 105 each send a frame including information (REASON) indicating the reason for not participating in data communication. For example, APs 104 and 105 may be currently performing data communication with different STAs, have insufficient resources (such as radio resources or communication processing load), and it may be determined that it is impossible to perform data communication with target STA 107. In this case, APs 104 and 105 each generate a frame including REASON = BUSY and send the frame to AP 100. Note that if APs 104 and 105 each determine not to join data transmission due to a disconnection to STA 107, the APs can generate a frame including REASON = DISCONNECTED and send that frame to AP 100. Even if, for example, resources are sufficient, and APs 104 and 105 are currently performing the communication to be protected, they can also generate and send a frame by setting their state to REASON. If APs 104 and 105 each determine that they can join data transmission ("Yes" in step S506), they each generate a frame including the frequency channel or link number available when joining data transmission and send that frame to AP 100 (step S508). Note that if APs 104 and 105 can join without imposing any conditions on available frequency resources or link numbers, the APs can send a frame to AP 100 indicating that the APs can join unconditionally, without including information such as frequency channels. If AP 100 selects AP 104 and 105 as the SAPs to send data to STA 107, then AP 104 and 105 each receive the data to be sent to STA 107 from AP 100 (step S509). At this time, AP 104 and 105 can each send an ACK to AP 100 based on the received data. Afterwards, AP 104 and 105 each receive a timing trigger frame indicating the data transmission to STA 107 (step S510). The trigger frame includes an AID assigned to each of AP 104 and 105, and corresponding to each AID includes information indicating the frequency channel or link to be used (in some cases, information indicating RU allocation). This allows AP 104 and 105 to identify which frequency channel or RU they should use to transmit data. Immediately after receiving the trigger frame, AP 104 and 105 each confirm whether their own device can transmit the frame (step S511).For example, if other communication devices use the frequency channel and RU specified by the trigger frame to transmit radio waves, or in an unfavorable communication environment such as a low SNR environment, APs 104 and 105 may each determine that they cannot transmit data (No in step S511). In this case, APs 104 and 105 each send a frame indicating the failure of data transmission to AP 100 (step S512). In this case, the frame to be sent includes information indicating the reason for the failure of data transmission (REASON), and an identifier indicating AIR BUSY can be stored in REASON. If data transmission fails, APs 104 and 105 each return to step S505. On the other hand, if it is determined that the device can transmit a frame immediately after receiving the trigger frame (Yes in step S511), APs 104 and 105 each send the data received in step S509 to STA 107 (step S513). Then, APs 104 and 105 each wait to receive an ACK from STA 107 (step S514). If an ACK is received (yes in step S514), APs 104 and 105 each generate an additional ACK to send to AP 100 (step S515) and send the ACK to AP 100 (step S516). Note that if APs 104 and 105 each receive a frame from AP 100 to acknowledge data transmission, APs 104 and 105 may each send an ACK to AP 100 for the data for which an ACK has already been received (step S516). APs 104 and 105 terminate the process based on successful acknowledgment of all data transmissions made by receiving ACKs from STA 107. Note that if an ACK is not received from STA 107 within a predetermined time (no in step S514), APs 104 and 105 may each notify AP 100 of this, thereby terminating the process.

[0094] Figure 6 This illustrates an example of the processing procedure when the MAP (AP 100) sends data to the STA 107 via the SAP (AP 104 and 105). Note that... Figure 6 The processing shown is Figure 4A and Figure 4B Step S406 and subsequent processing and Figure 5A and Figure 5B Step S505 corresponds to the processing in subsequent steps.

[0095] First, AP 100 sends frames (S601) to each AP (AP 104 and 105) located outside its own periphery and currently connected to STA 107, confirming whether to join data transmission to STA 107. AP 104 and 105 each send a response frame to AP 100 (S602). This response frame includes information indicating whether to join data transmission. Note that if each AP can join data transmission, the response frame may include information related to available frequency channels or links. On the other hand, if AP 104 and 105 cannot join data transmission, the response frame includes, for example, a reason for not joining. Examples of reasons for not joining are BUSY and DISCONNECTED. Based on the response frames, AP 100 selects the AP to join data transmission as the SAP and sends the data to be sent to STA 107 to each of the selected APs (AP 104 and 105) (S603). At this point, the SAPs (AP 104 and 105) directly send data to STA 107. Therefore, for example, after a predetermined period for preparing data transmission, AP 100 sends trigger frames to APs 104 and 105 respectively, indicating the timing of data transmission (S604). Upon receiving the trigger frames, APs 104 and 105 each transmit data to STA 107 using the frequency channel or link and RU specified by the trigger frames (S605). Then, upon receiving the data, STA 107 sends ACKs to APs 104 and 105, which are the transmission sources, respectively (S606). If APs 104 and 105 determine that data transmission was successful upon receiving ACKs, then APs 104 and 105 each send frames to AP 100 indicating the success of data transmission (S607). Note that if APs 104 and 105 do not receive all ACKs or the predetermined time has elapsed, then AP 100 sends messages to APs 104 and 105 respectively, confirming whether the transmission of all data was successful (S608). Note that if the data for which an ACK has not yet been received exists only in one of APs 104 and 105, the message can be sent only to that AP. If both APs 104 and 105 receive the message, they each return an ACK indicating the current reception status to AP100 (S609). In S607, both APs 104 and 105 can send a transmission failure notification to AP100.

[0096] In this way, APs 104 and 105 can communicate with the STA using the frequency channel or link indicated by AP 100. Therefore, for example, if multiple links (links 110 and 111) are connected between AP 105 and STA 107, an appropriate channel can be selected to transmit data from AP 100 to STA 107 via AP 105. Additionally, APs 104 and 105 can each use frequency channels designed to reduce interference, thereby improving communication performance.

[0097] Note that the data to be sent is not limited to data sent from AP 100, and can also be data pre-stored in APs 104 and 105 respectively. The data stored in APs 104 and 105 can be data obtained from a server on the network connected to STA 107 via APs 104 and 105 respectively. In this case, in Figure 6 The information sent from APs 104 and 105 in S602 may include, for example, the buffer size of data destined for STA 107. In this case, omitted. Figure 6 S603. For example, AP 104 can send data from AP 100 to STA 107, and AP 105 can send the held data to STA 107. In this case, in S603, AP 100 can send the data to be transmitted only to AP 104. For example, at least one of AP 104 and 105 can obtain data without AP 100 intervention, and use different frequency channels, links, and RUs to send the data held in the transmit buffer and the data received from AP 100. In this case, AP 100 can send the data to be transmitted to each of AP 104 and 105, and specify the frequency channels, etc., to be used to transmit the data and the data held in each AP in the trigger frame. Note that the frequency channels, etc., to be used can be associated with each data. That is, the frequency channels, etc., to be used can be specified for each data. For example, the first link is used for the data from AP 100, and the second link is used for the data held in AP 104 or 105. Instead of this designation, AP104 and 105 can each be notified of the amount of data that can be sent from AP 100 and the amount of data that can be held in AP104 and 105, including frequency channels, links, and RUs.

[0098] <Data Reception>

[0099] This section describes the processing procedure when AP 100 operates as a MAP to receive data from STA 107 via APs 104 and 105, which operate as SAPs. First, reference will be made to... Figure 7A and Figure 7BThis describes the processing performed by AP 100. This processing begins if data to be sent from STA 107 to AP 100 exists. Note that this processing begins when connections are established between AP 100 and APs 104 and 105, and between APs 104 and 105 and STA 107, and AP 100 may perform step S706 and subsequent steps, which will be described later, upon receiving data. In the following description, descriptions of the same parts as in the data transmission processing example will be simplified or omitted.

[0100] Steps S701 to S705 are the same as steps S401 to S405 in Processing Example 1. Then, AP 100 sends a frame to confirm whether each AP can proceed with the next data reception (step S706). This frame may include information such as the amount of data and the time used for transmission. Furthermore, if AP 100 assigns an AID to a STA, it may send information to each AP to associate the STA's MAC address with the AID assigned by AP 100. Next, AP 100 receives responses from each AP to the frames in step S706 (step S707). This frame may include information indicating whether each AP can join the data reception, and if each AP can join, the frame includes conditions for joining. The conditions for joining may include, for example, information specifying the frequency channel and bandwidth available for data reception. If each AP, different from AP 100, assigns an AID to a STA, it may send information to AP 100 to associate the STA's MAC address with the AID assigned by the AP to the STA.

[0101] Based on the information received in step S707, AP 100 determines the SAP from which it will receive data (step S708). At this time, AP 100 can send a frame to the selected SAP to notify the SAP that it has been selected as the AP to receive data. In this embodiment, APs 104 and 105 are selected as SAPs.

[0102] Next, AP 100 determines the frequency channel or link to be used by each SAP (step S709). If each SAP uses OFDMA for communication, AP 100 determines the RU to be used to receive data from STA 107. Note that the processes in steps S708 and S709 can be performed simultaneously.

[0103] If the SAPs to be included in data reception and the frequency channels and RUs to be used by each SAP are determined, AP 100 determines whether data reception can be performed in this state (step S710). For example, if no SAP can be included in data reception, the SAP cannot receive data from the STA, and AP 100 therefore determines that data reception is impossible ("No" in step S710). In this case, AP 100 can reprocess from step S706 by changing the data volume and conditions. In this case, AP 100 can decide to receive data directly from the STA. Note that when a response is received from each peripheral AP in step S707, AP 100 can perform the determination process in step S710. The process in step S709 can be performed before the process in step S706. In this case, the information sent by each peripheral AP of AP 100 in step S707 can only indicate whether to include data reception. This allows AP 100 to immediately determine the new channel allocation and send frames to each AP to confirm whether to include it.

[0104] If data can be received ("Yes" in step S710), AP 100 sends a frame to each SAP (AP 104 and 105) as a trigger to cause STA 107 or each SAP to send data (step S711). The trigger frame has, for example, Figure 13 The structure shown. Fields 1201 to 1213 and... Figure 12 The same applies. However, if the value of trigger type subfield 1209 is set to "10", the trigger frame indicates data reception via multi-AP communication. Figure 13 In the structure shown, the AID subfield 1301 is set in the user information field 1206. The AID subfield 1301 contains the AID (Associated ID) assigned by the AP when connecting to the STA. Table 4 below shows the correspondence between the values ​​of the AID subfield 1301 in the user information field 1206 and their meanings.

[0105] [Table 4]

[0106]

[0107] In this embodiment, the AID assigned to the currently connected STA is set as the value of the AID subfield 1301. Note that the AID can be assigned to each STA by the MAP. If the value of the AID subfield 1301 is set to "1" through "2007", then this value is the value of the AID assigned to the STA. If other values ​​are set, refer to Table 4.

[0108] If each SAP (AP 104 and 105) can receive data from STA 107 according to the trigger frame, the SAP sends a notification to AP 100 indicating successful data reception. This frame includes information indicating whether the SAP has successfully received the data. Note that this frame can only be sent if the SAP has failed to receive the data. Using this notification, AP 100 can determine whether the SAP has successfully received the data (step S712). Then, if AP 100 determines that the SAP has successfully received the data ("Yes" in step S712), AP 100 receives the data sent by STA 107 from the SAP (step S713). Note that if no data is received in step S713 after sending the trigger frame in step S711 without receiving a notification, AP 100 can determine that the SAP has failed to receive the data. That is, the processing in step S712 can be performed regardless of the notification from the SAP. If no success / failure notification for data reception and the data from step S713 are received even after the scheduled time, AP 100 can determine that SAP failed to receive the data. If AP 100 determines that SAP failed to receive the data, the process can return to step S706.

[0109] If AP 100 receives data from STA 107 via SAP in step S713 and the data reception is successful, AP 100 generates an ACK associated with the data (step S714). Then, AP 100 sends the generated ACK to SAP (step S715). Next, AP 100 determines whether there is data to be received (step S716). For example, if the data received via SAP indicates a buffer size (indicating that the data to be sent by STA 107 is still available), AP 100 determines that there is data to be received ("Yes" in step S716). In this case, for example, based on information related to the reception result (such as the SAP used when the data reception was successful), AP 100 can select the AP to be used as SAP in subsequent data reception processing (step S717). For example, if the processing is re-executed from step S706, AP 100 can only send frames to APs that have successfully received data previously to confirm whether the AP can join. If there is no data to be received ("No" in step S716), AP 100 ends the process.

[0110] Note that OFDMA can be used when AP 100 receives data from each SAP in step S713. That is, AP 100 can send trigger frames to each SAP, and data can be sent from the SAP to AP 100 based on the trigger frames. If it is determined in step S716 that there is data to be received, processing can restart from step S711. Therefore, the processing overhead in steps S706 to S710 can be eliminated, thereby achieving communication with higher throughput.

[0111] Figure 8A and 8B This illustrates an example of the processing procedure when APs 104 and 105 cooperate with each other to receive data from STA 107. Note that the information included in each frame is different from... Figure 5A and Figure 5B The same as in [previous steps], and its description will be omitted. This process begins when APs 104 and 105 each receive an information acquisition request from a neighboring AP from AP 100. The processes in steps S801 to S804 are the same as [previous steps]. Figure 5A The processes in steps S501 to S504 are the same, and their descriptions will be omitted.

[0112] APs 104 and 105 each receive a frame from AP 100 confirming whether to join data transmission in preparation for data reception from STA 107 (step S805). If APs 104 and 105 do not join data reception ("No" in step S806), the APs send a frame to AP 100 indicating that they will not join data communication (step S807). Note that, similar to step S507, APs 104 and 105 can each send a frame including information (REASON) indicating the reason for not joining data communication. If APs 104 and 105 determine that they can join data transmission ("Yes" in step S806), the APs generate a frame including the frequency channel or link number available when joining data reception and send the frame to AP 100 (step S808). Note that if APs 104 and 105 can each join without imposing any conditions on available frequency resources or link numbers, then the AP can send a frame to AP 100 indicating that the AP can join unconditionally, without including frequency channels, etc.

[0113] If AP 100 selects either AP 104 or 105 as the SAP to receive data from STA 107, then the AP receives a trigger frame from AP 100 indicating the timing for receiving data from STA 107 (step S809). The structure of the received trigger frame at this time is as follows: Figure 13As shown. The trigger frame includes the AID (AP ID) assigned to each of AP104 and 105, as well as information on the frequency channel and RU allocation corresponding to the AID. AP104 and 105 can each identify that they should use the frequency channel and RU specified by the trigger frame to transmit data. By analyzing the trigger frame, AP104 and 105 can each specify the frequency channel (or link number) and RU that should be used to receive data (step S810). For example, if the channel subfield is "5" and the RU subfield is "2", then AP104 or 105 identifies that the second RU (RU 2) in channel 5 should be assigned to STA 107. Note that the trigger frame can be configured to specify only the frequency channel or link number. In this case, for example, if "channel 5" is assigned, AP104 or 105 can freely assign RUs in channel 5. For example, suppose AP104 communicates with STA 109, which is other than STA 107, and wants to receive data from STA 109. In this case, AP 104 can allocate RUs to STAs 107 and 109 within the range of the allocated frequency channels, thereby enabling the STAs to perform data transmission using the RUs.

[0114] APs 104 and 105 each send a trigger frame to STA 107 using the frequency channel or link number specified in the trigger frame received from AP 100 (step S811). APs 104 and 105 each receive data from STA 107 based on the trigger frame. APs 104 and 105 each determine whether the data reception was successful (step S812). If the data reception was unsuccessful ("No" in step S812), the APs notify AP 100 of the data reception failure (step S813). Note that APs 104 and 105 may each send data to AP 100 including information (REASON) indicating the reason for the data reception failure. APs 104 and 105 each return the process to step S805. On the other hand, if the data reception was successful ("Yes" in step S812), APs 104 and 105 each return an ACK associated with the data to STA 107 (step S814). Then, APs 104 and 105 each send a frame to AP 100 indicating that the data has been correctly received (step S815). Note that the transmission of this frame can be omitted. Then, APs 104 and 105 each send the received data to AP 100 (step S816). APs 104 and 105 each confirm whether they have received a response from AP 100 (step S817). If a response is received (yes in step S817), the AP analyzes the content of the response (step S818). Then, APs 104 and 105 each determine whether retransmission is necessary based on the response (step S819). For example, if the response is a negative acknowledgment, APs 104 and 105 each determine that retransmission is necessary (yes in step S819). If the response is a positive acknowledgment, APs 104 and 105 each determine that retransmission is unnecessary (no in step S819). Furthermore, if AP 104 and 105 do not receive a response from AP 100 within a predetermined time period after data transmission ("No" in step S817), the APs may determine that retransmission is necessary. If AP 104 and 105 each determine that retransmission is unnecessary ("No" in step S819), the process ends.

[0115] Figure 9 This illustrates an example of the processing procedure when the MAP (AP 100) transmits data from STA 107 via SAP (AP 104 and 105). Note that... Figure 9 The processing shown is Figure 7A and Figure 7B Step S706 and subsequent processing and Figure 8A and Figure 8B Step S805 corresponds to the processing in subsequent steps.

[0116] First, AP 100 sends frames (S901) to each AP (AP 104 and 105) located on its periphery and currently connected to STA 107 to confirm whether to join data reception from STA 107. AP 104 and 105 each send a response frame to AP 100 (S902). This response frame includes information indicating whether to join data reception. Note that if each AP can join data reception, the response frame may include information related to available frequency channels or links. On the other hand, if AP 104 and 105 cannot join data reception, the response frame includes, as described above, reasons for not joining (such as BUSY or DISCONNECTED). Based on the response frames, AP 100 selects the APs to join data reception as SAPs and sends trigger frames (S903) to each selected AP (AP 104 and 105) to trigger data reception from STA 107. Upon receiving a trigger frame, APs 104 and 105 each interpret the content of the trigger frame to specify the frequency channel or link number assigned to their own devices and the RU. Then, APs 104 and 105 each send a trigger frame to STA 107 for receiving data from STA 107 (S904). Upon receiving the trigger frame, STA 107 sends data to the AP (AP 104 or 105) that is the source of the trigger frame (S905). Upon receiving data from STA 107, APs 104 and 105 each return an ACK associated with the received data to STA 107 (S906). If APs 104 and 105 can each receive all the data from STA 107, then APs 104 and 105 each send a frame to AP 100 indicating that data reception is complete (S907). Then, APs 104 and 105 each transmit the data received from STA 107 to AP 100 (S908). Note that AP 100 can send TFs (transmission tactical units) to APs 104 and 105 respectively for data to be transmitted by the AP. Upon receiving data, AP 100 sends an ACK (S909) to the AP (AP 104 or 105) that is the source of the data transmission.

[0117] As described above, APs 104 and 105 can each communicate with STA 107 using the frequency channel or link indicated by AP 100. Note that the case of data transmission from STA 107 to AP 100 has been described above, but the invention is not limited thereto. For example, when transmitting data from STA 107 to AP 104 or 105, AP 100 can specify a frequency channel or link number. In this case, Figure 9In S902, the information sent from AP 104 (AP 105) may include, for example, the buffered amount of data sent by STA 107. For instance, AP 104 can transmit data from STA 107 to AP 100, and AP 105 can receive data sent from STA 107 as data destined for itself. In this case, in S908, the data transmitted from each SAP to the MAP is only from AP 104 to AP 100, and no data transmission from AP 105 to AP 100 occurs. Meanwhile, in S909, the ACK sent from AP 100 is only sent to AP 104, and not to AP 105. Furthermore, if AP 104 and 105 each establish multiple links with STA 107, and AP 100 specifies multiple links, some of these links can be used to perform communication with STA 107 for AP 100.

[0118] Note that if the AP communicates with multiple STAs, for example, the AID of one STA is stored in... Figure 13 The AID subfield 1301 of the user information field in the frame structure shown allows for different user information fields to be set for each STA. Frequency channel or link number and RU allocation are specified for each STA. Note that the same frequency channel or link number can be specified for multiple AIDs. In this case, upon receiving the trigger frame, the AP can perform RU allocation, etc., within the resource range specified for each STA on its own device. User information fields can be set for each STA individually, or a single user information field can be set for multiple STAs. For example, information indicating information related to multiple STAs can be prepared, and information related to multiple AIDs can be specified. For example, information specifying the number of STAs can be included between the AP ID subfield 1211 and the AID subfield 1301. In this case, after the AID subfield 1301, channel subfield 1212, and RU allocation subfield 1213 for the first STA, the AID subfield 1301, channel subfield 1212, and RU allocation subfield 1213 can be set for the second STA. After setting the AID subfield 1301 for multiple STAs consecutively, the channel subfield 1212 and RU allocation subfield 1213 for each STA can be set. Subfields such as the cascading subfield mentioned above can be set without using information for specifying the number of STAs.

[0119] Note that the scenario where AP 100 sends trigger frames of radio signals to APs 104 and 105 respectively during the aforementioned data transmission / reception has been described. However, AP 100 can also send frames corresponding to the trigger frames via wired signals. Similarly, communication between AP 100 and each of APs 104 and 105 can be performed via wired lines. That is, in one example, AP 100 is an access point compliant with the IEEE 802.11 standard family, but it can be a control device connected via wire to an AP capable of performing communication compliant with the IEEE 802.11 standard family. In this case, AP 100 does not need to comply with the IEEE 802.11 standard family, or even have wireless communication capabilities. For example, in Figure 1 In the example shown, APs 100 and 106 are connected via a wire, and APs 100 and 104 are wirelessly connected. If AP 100 uses APs 106 and 104 as SAPs to send data to STA 109, at least a portion of the communication between APs 100 and 106 can be sent / received via a wired line.

[0120] Furthermore, the SSID and BSSID of APs 100, 104, 105, and 106 that cooperate with each other can be the same or different. Note that if the APs have the same BSSID, an additional identifier is needed to identify APs 100 and 104 through 106. If the SSIDs of APs 104 through 106 are different, then STAs 107 through 109 that communicate directly with these APs need to belong to different networks simultaneously. Therefore, APs 100 and 104 through 106 can have different BSSIDs and common SSIDs. Thus, STAs can identify each AP by its BSSID and its network affiliation, enabling the APs to cooperate in performing data communication.

[0121] <Variation Example>

[0122] Similar to the method described above, AP 100 and multiple STAs can send / receive data via SAPs (AP 104 and 105). For example, AP 100 can communicate with STA 109 via AP 104 and with STA 107 via AP 105. Note that, as mentioned above, even without communicating with STAs, for communication between AP 104 and STA 109, and between AP 105 and STA 107, AP 100 can indicate information such as the frequency channel to be used via trigger frames. Note that in this process, AP 104 and 105 can each... Figure 5A Step S508 or Figure 8AIn step S808, AP 100 is notified of the information (e.g., AID) of the communicable STAs. By obtaining the information of the communicable STAs of AP 104 and 105, AP 100 can flexibly set the STA as a communication partner and appropriately set the frequency channel to be used for communication with the STA.

[0123] Reference Figure 10 This example describes the processing procedure when sending data to multiple STAs. Note that, compared to... Figure 6 In the illustrated process, the same reference numerals denote the same parts, and their descriptions will be omitted. Each SAP (AP 104 and 105) uses the frequency channel and RU specified in the trigger frame received from the MAP (AP 100) to transmit data to the designated STA (S1001). That is, for example, as... Figure 13 As shown, the trigger frame includes information such as the AID of the STA (Station) designated as the communication counterpart via the user information fields of each SAP, the frequency channel to be used for communication with that STA, and RU allocation information. Figure 10 In the example shown, the AID of STA 109 and the frequency channel (and RU) to be used are included in the user information field of AP 104, and the AID of STA 107 and the frequency channel (and RU) to be used are included in the user information field of AP 105. Upon receiving data from the SAP, each STA sends a response (ACK) associated with that data (S1002). APs 104 and 105 then each receive this response.

[0124] As described above, the MAP can control data transmission from multiple SAPs to different STAs by specifying frequency channels and RUs. AP 100 specifies, for example, the use of channel 5 for communication between AP 105 and STA 107, and specifies the use of channel 36 for communication between AP 104 and STA 109, thereby preventing communication from interfering with each other.

[0125] If AP 100 does not send data to STA, and each SAP sends the data it holds to each STA, then in Figure 10In S602, AP 100 can obtain information about the buffer size of the data to be sent from each SAP to each STA. Note that in this case, the processing in S603 is omitted. Note that although AP 104 sends data from AP 100 to STA 109, AP 105 can send data held in its own device to STA 107. In this case, in S603, AP 100 only sends data to AP 104. Furthermore, although AP 105 sends data from AP 100 to STA 107, AP 104 can send data held in its own device to STA 109.

[0126] Next, we will refer to Figure 11 This example describes the processing procedure when data is sent from multiple STAs. Note that, with... Figure 9 In the illustrated process, the same reference numerals denote the same components, and their descriptions will be omitted. Each SAP (each of APs 104 and 105) uses the frequency channel and RU specified in the trigger frame received from the MAP (AP 100) to send a trigger frame (S1101) to the designated STA for triggering data transmission. The trigger frame sent from the MAP to each SAP also includes information for specifying the AID of the STA as the communication counterpart, the frequency channel to be used for communication with that STA, and the RU allocation through the user information field of each SAP. Then, each SAP sends a trigger frame to the STA as the communication counterpart, wherein the trigger frame is used to specify that the specified frequency channel (and RU) should be used to transmit data. Based on the received trigger frame, each STA uses the specified frequency channel (and RU) to send data to the SAP, which is the source of the trigger frame (S1102). Figure 11 In the example shown, STA 107 sends data to AP 105, and STA 109 sends data to AP 104. Then, each SAP sends an ACK associated with the received data to the STA that was the data source, and each STA receives the ACK (S1103).

[0127] As described above, the MAP can control data transmission from multiple STAs by specifying frequency channels and RUs. AP100 specifies, for example, the use of channel 5 for communication between AP 105 and STA 107, and specifies the use of channel 36 for communication between AP104 and STA 109, thereby preventing communication from interfering with each other.

[0128] If AP 100 does not receive data from each STA, and each STA sends data to each SAP, then... Figure 11In S902, AP 100 can obtain information about the buffer size of data to be sent by each STA from each SAP. Note that although AP 104 sends data from STA 109 to AP 100, AP 105 does not need to send data from STA 109 to AP 100 as data destined for itself. Furthermore, although AP 105 sends data from STA 107 to AP 100, AP 104 does not need to send data from STA 109 to AP 100.

[0129] By making execution Figure 10 or Figure 11 The illustrated processing is made possible by requiring APs 104 and 105 to each possess only certain AP functions. That is, APs 104 and 105 each operate primarily as SAPs for multi-AP communication, managing PHY-level operations, and can delegate general AP functions (such as RU allocation) to MAPs. Therefore, in system configurations using multiple APs, the cost increase caused by increasing the number of APs can be suppressed, and the maximum throughput with STAs can be adjusted flexibly by changing the number of SAPs. For example, in use cases such as MR (Mixed Reality) or VR (Virtual Reality) that require low latency and high communication capacity, the number of SAPs used can be increased. On the other hand, in information communication for software updates operating in the background, low latency and high communication capacity may not be required. In this case, the number of SAPs used can be reduced. In this way, by allowing users (STAs) to adjust the number of SAPs, the necessary throughput can be ensured and throughput can be easily increased.

[0130] In the above embodiments, data transmission to the STA and data reception from the STA have been explained separately. However, this is not intended for each device to perform only transmission or reception. For example, each device can perform data transmission and data reception simultaneously, and for example, data transmission and data reception can be performed alternately in a time-division manner. For example, it is possible to... Figure 6 Execution after processing in S603 to S609 Figure 9 The processing in S903 to S909 can then be executed again as needed. Figure 6 The processing in S603 to S609. For example, in Figure 6 After the processing in S603 to S609 is repeated a first predetermined number of times (e.g., three times), Figure 9 The processing in S903 to S909 can be repeated a second predetermined number of times (e.g., five times). Figure 6 Execution prior to the processing in S603 to S609 Figure 9 The processing in S903 to S909. In any case, Figure 6The processing in S601 and S602 and Figure 9 The processing in S901 and S902 can be executed only once, until, for example, a given amount of data has been sent / received. This allows for efficient data communication with reduced communication control processing overhead. The same applies to... Figure 10 and Figure 11 The process is shown. Each device can repeat the process. Figure 6 and Figures 9 to 11 The processes shown may be repeated, or one of these processes may be repeated a predetermined number of times, and then another of these processes may be executed. At this point, as described above, Figure 6 and Figure 10 S601 and S602 and Figure 9 and Figure 11 S901 and S902 can be executed only once, or they can be executed each time a process begins.

[0131] <<Other Embodiments>>

[0132] This invention can be implemented by supplying a program for implementing one or more functions of the above embodiments to a system or device via a network or storage medium, and causing one or more processors in the computer of the system or device to read and execute the program. This invention can also be implemented by a circuit (e.g., an ASIC) for implementing one or more functions.

[0133] This invention is not limited to the embodiments described above, and various changes and modifications can be made within the spirit and scope of this invention. Therefore, the appended claims are made to inform the public of the scope of this invention.

Claims

1. An access point device, comprising: A sending unit is configured to send a trigger frame to other access point devices that coordinate with the access point device in a multi-access point manner. The trigger frame is used to trigger communication compliant with the IEEE 802.11 standard series between the other access point devices and the station device. The trigger frame includes an associated ID (AID) field in the user information field, indicating identification information of the other access point devices, a concatenation field following the AID field, a first channel field, and a first resource unit (RU) allocation field. The first channel field includes a value indicating a frequency channel with a bandwidth of 20 MHz or a multiple of 20 MHz to be used for the communication and a value indicating a frequency band including the frequency channel. The first RU allocation field includes a value indicating the allocation of RUs to be used for the communication. Wherein, the value of the first RU allocation field indicates the RU to be used for the communication among a plurality of RUs included in the frequency channel indicated by the first channel field, and The cascading field indicates whether the second channel field and the second RU allocation field used for the communication are arranged after the first RU allocation field.

2. The access point device of claim 1, wherein, In the case where multiple links using different frequency channels, including 2.4GHz links, 5GHz links, and 6GHz links, are established between the other access point devices and the station device, the transmitting unit transmits the trigger frame by including an indication of which of the multiple links will use a value for the communication as an indication of the frequency channel.

3. The access point device of claim 2, wherein, The value indicating which of the plurality of links will be used for the communication is the link number assigned to the link to be used, from the link numbers assigned to the plurality of links respectively. The other access point devices manage the link number and the value of the frequency channel used for the link in association with each other, and identify the frequency channel to be used based on the link number.

4. The access point device of claim 3, wherein, Use the link number assigned by the other access point devices as the link number for each of the multiple links.

5. The access point device of claim 3, wherein, The link number assigned by the access point device is used as the link number for each of the plurality of links.

6. The access point device of claim 1, wherein, The transmitting unit transmits the trigger frame by including information about the other access point devices in the AID field in association with a value indicating the frequency channel.

7. The access point device of claim 1, wherein, The transmitting unit transmits the trigger frame by including information about the station equipment in association with a value indicating the frequency channel.

8. The access point device of claim 1, wherein, The value indicating the frequency channel corresponds to the channel number defined in the IEEE 802.11 standard series.

9. The access point device according to claim 1, wherein, The communication includes communication performed when the other access point device transmits communication between the access point device and the station device.

10. The access point device according to claim 1, wherein, The trigger frame is a trigger frame defined in the IEEE 802.11 standard series, and the transmitting unit transmits the frame to the other access point device using wireless communication.

11. A computer-readable storage medium storing a program that, when executed by a computer, causes the computer to perform operations performed by an access point device as defined in any one of claims 1 to 10.

12. An access point device, comprising: A transmitting unit is configured to, when multiple links are established between other access point devices and station devices, send a trigger frame to the other access point devices that are coordinating with the other access point devices in multi-access point communication. The trigger frame is used to trigger communication compliant with the IEEE 802.11 standard series between the other access point devices and the station devices. The trigger frame includes an Associated ID (AID) field in the user information field, indicating identification information of the other access point devices, a concatenation field following the AID field, a first channel field, and a first resource unit (RU) allocation field. The first channel field includes a value indicating which of the multiple links will be used for the communication and a value indicating the frequency band including the frequency channel corresponding to the link to be used. The first RU allocation field includes a value indicating the allocation of the RU to be used for the communication. Wherein, the value of the first RU allocation field indicates the RU to be used for the communication among a plurality of RUs included in the frequency channel indicated by the first channel field, and The cascading field indicates whether the second channel field and the second RU allocation field used for the communication are arranged after the first RU allocation field.

13. A computer-readable storage medium storing a program that, when executed by a computer, causes the computer to perform operations performed by the access point device as defined in claim 12.

14. An access point device, comprising: A communication unit is configured to receive, from other access point devices coordinating with the access point device in a multi-access point manner, a trigger frame compliant with the IEEE 802.11 standard series for triggering communication with the station device. This trigger frame includes an Associated ID (AID) field in the user information field, indicating identification information of the access point device; a concatenation field following the AID field; a first channel field; and a first resource unit (RU) allocation field. The unit communicates with the station device using the frequency channel indicated in the first channel field and the RU indicated in the first RU allocation field. The first channel field includes a value indicating a frequency channel with a bandwidth of 20 MHz or a multiple of 20 MHz to be used for the communication and a value indicating a frequency band including the frequency channel. The first RU allocation field includes a value indicating the allocation of RUs to be used for the communication. Wherein, the value of the first RU allocation field indicates the RU to be used for the communication among a plurality of RUs included in the frequency channel indicated by the first channel field, and The cascading field indicates whether the second channel field and the second RU allocation field used for the communication are arranged after the first RU allocation field.

15. The access point device according to claim 14, wherein, When multiple links using different frequency channels are established between the access point device and the station device, the trigger frame includes a value indicating which of the multiple links will be used for communication between the access point device and the station device as a value indicating the frequency channel.

16. The access point device of claim 15, wherein, The value indicating which of the plurality of links will be used for the communication is the link number assigned to the link to be used, from the link numbers assigned to the plurality of links respectively. The access point device manages the link number and the value of the frequency channel used for the link in association with each other, and identifies the frequency channel to be used based on the link number.

17. The access point device of claim 16, wherein, The link number assigned by the access point device is used as the link number for each of the plurality of links.

18. The access point device of claim 16, wherein, Use the link number assigned by the other access point devices as the link number for each of the multiple links.

19. The access point device of claim 14, wherein, The trigger frame includes information about the access point device in association with the value indicating the frequency channel.

20. The access point device of claim 14, wherein, The trigger frame, associated with a value indicating the frequency channel, includes information about the station equipment.

21. The access point device according to claim 14, wherein, The value indicating the frequency channel corresponds to the channel number defined in the IEEE 802.11 standard series.

22. The access point device of claim 14, wherein, The communication includes communication performed when the access point device transmits communication between the other access point devices and the station device.

23. The access point device of claim 14, wherein, The trigger frame is a trigger frame defined in the IEEE 802.11 standard series, and the communication unit receives the trigger frame from the other access point device by using wireless communication.

24. A computer-readable storage medium storing a program that, when executed by a computer, causes the computer to perform operations performed by an access point device as defined in any one of claims 14 to 23.

25. An access point device, comprising: A communication unit, configured to, in the case of establishing multiple links between the access point device and the station device, receive from other access point devices coordinating with the access point device in multi-access point communication, a trigger frame for initiating communication with the station device in accordance with the IEEE 802.11 standard series. This trigger frame includes an Associated ID (AID) field in the user information field indicating identification information of the access point device, a concatenation field following the AID field, a first channel field, and a first resource unit (RU) allocation field. The unit communicates with the station device using the link indicated in the first channel field and the RU indicated in the first RU allocation field. The first channel field includes a value indicating which of the multiple links will be used for communication between the access point device and the station device, and a value indicating the frequency band of the frequency channel corresponding to the link to be used. The first RU allocation field includes a value indicating the allocation of the RU to be used for the communication. Wherein, the value of the first RU allocation field indicates the RU to be used for the communication among a plurality of RUs included in the frequency channel indicated by the first channel field, and The cascading field indicates whether the second channel field and the second RU allocation field used for the communication are arranged after the first RU allocation field.

26. A computer-readable storage medium storing a program that, when executed by a computer, causes the computer to perform operations performed by the access point device as defined in claim 25.

27. A control method executed by an access point device, the control method comprising: A trigger frame is sent to other access point devices that coordinate with the access point device in a multi-access point manner. The trigger frame is used to trigger communication compliant with the IEEE 802.11 standard series between the other access point devices and the station device. The trigger frame includes an Associated ID (AID) field in the user information field, indicating identification information of the other access point devices, a concatenation field following the AID field, a first channel field, and a first resource unit (RU) allocation field. The first channel field includes a value indicating the frequency channel to be used for the communication and a value indicating the frequency band including the frequency channel. The first RU allocation field includes a value indicating the allocation of RUs to be used for the communication. Wherein, the value of the first RU allocation field indicates the RU to be used for the communication among a plurality of RUs included in the frequency channel indicated by the first channel field, and The cascading field indicates whether the second channel field and the second RU allocation field used for the communication are arranged after the first RU allocation field.

28. A computer-readable storage medium storing a program that, when executed by a computer, causes the computer to perform the control method according to claim 27.

29. A computer program product comprising a program that, when executed by a computer, causes the computer to perform the control method according to claim 27.

Images