Access point device, communication device, communication method, and program

Abstract

An access point apparatus for performing communication conforming to IEEE 802.11 standard series performs communication with another communication apparatus belonging to a first network constructed by the access point apparatus by using one of a first channel access method using at least a predetermined primary channel in one link and a second channel access method not using the primary channel but using a non-primary channel different from the primary channel among a plurality of channels included in the link. In a case where a radio frame relating to occupation of at least one channel including the primary channel is received from another access point apparatus constructing a second network different from the first network and the at least one channel including the primary channel is occupied in the second network, the access point apparatus transmits a notification to the other communication apparatus indicating that the second channel access method should be used or transmission of a radio frame is prohibited.

Description

Technical Field

[0001] This invention relates to a communication technology in a communication device capable of performing communication using a communication link formed by multiple channels. Background Technology

[0002] In recent years, with the increase in the amount of data being communicated, communication technologies such as wireless LANs (Local Area Networks) have been developed. The IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard series is well-known as the main communication standard for wireless LANs. The IEEE 802.11 standard series includes IEEE 802.11a / b / g / n / ac / ax / be standards. To further improve communication reliability, the IEEE 802.11bn standard was developed as the successor to the IEEE 802.11be standard. In the IEEE 802.11WG (working group) that developed the IEEE 802.11bn standard, the goals and scope of the standard are set in the UHR SG, and the detailed technical content to be included in this standard is defined in the TGbn. Note that UHR SG is an abbreviation for Ultra High Reliability Study Group, and TGbn is an abbreviation for TaskGroup bn.

[0003] As one of the candidate technologies included in the IEEE 802.11bn standard, techniques for efficiently utilizing frequency resources in communication methods using communication links formed by multiple channels have been investigated. For example, PTL 1 describes a technique for performing communication using another channel when the primary channel used to obtain transmission rights is unavailable.

[0004] Citation List

[0005] Patent documents

[0006] PTL 1: US Patent No. 11696353 Summary of the Invention

[0007] Technical issues

[0008] This invention provides a technique for enabling more efficient use of frequency resources in communication systems that utilize communication links formed by multiple channels.

[0009] Solution to the problem

[0010] According to one aspect of the invention, a communication apparatus is an access point device for performing communications conforming to the IEEE 802.11 standard series. The access point device includes a communication component for communicating with another communication device belonging to a first network constructed by the access point device using one of a first channel access method and a second channel access method. The first channel access method uses at least a predetermined primary channel in a link, and the second channel access method does not use the primary channel but uses a non-primary channel among a plurality of channels included in the link, different from the primary channel. Upon receiving a radio frame from another access point device constructing a second network different from the first network relating to the occupancy of at least one channel including the primary channel, and the at least one channel including the primary channel is occupied in the second network, the communication component sends a notification to the other communication device instructing that the second channel access method should be used or prohibiting the transmission of radio frames.

[0011] Advantages of the invention

[0012] According to the present invention, it is possible to use frequency resources more efficiently in communication systems that use communication links formed by multiple channels.

[0013] 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

[0014] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0015] Figure 1 This is a view showing an example of the configuration of a wireless communication system;

[0016] Figure 2A This is a schematic diagram illustrating an example of a timing diagram when a communication device transmits data;

[0017] Figure 2A This is a schematic diagram illustrating an example of a timing diagram when a communication device transmits data;

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

[0019] Figure 4 This is a block diagram illustrating an example of the functional configuration of a communication device;

[0020] Figure 5It is a sequence diagram illustrating an example of the communication process in a wireless communication system;

[0021] Figure 6A This is a flowchart illustrating an example of a process performed by the AP;

[0022] Figure 6B This is a flowchart illustrating an example of a process performed by the AP;

[0023] Figure 7A This is a flowchart illustrating an example of a process performed by the AP;

[0024] Figure 7B This is a flowchart illustrating an example of a process performed by the AP;

[0025] Figure 8A This is a flowchart illustrating an example of a process performed by the AP;

[0026] Figure 8B This is a flowchart illustrating an example of a process performed by the AP;

[0027] Figure 9 This is a flowchart illustrating an example of a process performed by the AP;

[0028] Figure 10A This is a flowchart illustrating an example of a process performed by the STA;

[0029] Figure 10B This is a flowchart illustrating an example of a process performed by the STA;

[0030] Figure 10C This is a flowchart illustrating an example of a process performed by the STA;

[0031] Figure 11 This is a flowchart illustrating an example of a process performed by the STA;

[0032] Figure 12 This is a flowchart illustrating an example of a process performed by the STA;

[0033] Figure 13 This is a flowchart illustrating an example of a process performed by the STA;

[0034] Figure 14 This is a sequence diagram illustrating another example of the communication process in a wireless communication system;

[0035] Figure 15A This is a flowchart illustrating a variation of the processing procedure performed by the AP;

[0036] Figure 15BThis is a flowchart illustrating a variation of the processing procedure performed by the AP;

[0037] Figure 16A This is a flowchart illustrating a variation of the processing procedure performed by the AP;

[0038] Figure 16B This is a flowchart illustrating a variation of the processing procedure performed by the AP;

[0039] Figure 17A This is a flowchart illustrating a variation of the processing procedure performed by the AP;

[0040] Figure 17B This is a flowchart illustrating a variation of the processing procedure performed by the AP;

[0041] Figure 18 This is a flowchart illustrating a variation of the processing procedure performed by the AP;

[0042] Figure 19A This is a flowchart illustrating a variation of the process performed by the STA;

[0043] Figure 19B This is a flowchart illustrating a variation of the process performed by the STA;

[0044] Figure 19C This is a flowchart illustrating a variation of the process performed by the STA;

[0045] Figure 20 This is a flowchart illustrating a variation of the process performed by the STA; and

[0046] Figure 21 This is a flowchart illustrating a variation of the process performed by the STA. Detailed Implementation

[0047] 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 the invention is not limited to claiming all such features, and multiple such features may be appropriately combined. Furthermore, in the drawings, the same reference numerals are given for the same or similar configurations, and redundant descriptions thereof are omitted.

[0048] (System Configuration)

[0049] Figure 1An example configuration of a wireless communication system according to this embodiment is shown. The wireless communication system includes, for example, an access point (AP 101) and a station (STA 102). Each of AP 101 and STA 102 is a communication device capable of performing wireless communication conforming to the IEEE 802.11 standard family. In this embodiment, AP 101 and STA 102 will sometimes be collectively referred to as communication devices unless it is necessary to distinguish between them. IEEE is an abbreviation for the Institute of Electrical and Electronics Engineers. Figure 1 This illustrates the configuration of STA 102 joining network 103, which is constructed by AP 101. Network 103 can also be referred to as a Basic Service Set (BSS). Note that... Figure 1 The diagram illustrates a situation where a network 113, formed by AP 111 and STA 112, exists near a network 103 formed by AP 101 and STA 102. Similar to AP 101 and STA 102, each of AP 111 and STA 112 is a communication device capable of performing wireless communications conforming to the IEEE 802.11 standard family. For AP 101 and STA 102, network 103 is the BSS to which the devices are connected and can be referred to as the self-BSS. On the other hand, for AP 101 and STA 102, network 113 is a network that may interfere with the self-BSS and can be referred to as the overlapping BSS (OBSS). Note that... Figure 1 The example shown illustrates one AP and one STA in each of two networks, but multiple APs or multiple STAs can exist in one network. In this case, multiple STAs can connect to one AP, or one STA can connect to multiple APs. Note that the following description focuses on AP 101 and STA 102, but AP 111 and STA 112 can have the same functionality.

[0050] In this embodiment, AP 101 and STA 102 are configured to perform a communication method compliant with the IEEE 802.11bn standard. The IEEE 802.11bn standard is the successor to the IEEE 802.11be standard, aiming to achieve a maximum transmission rate of 46.08 Gbps (gigabits per second). The IEEE 802.11bn standard plans to implement features as key characteristics for achieving highly reliable communication, low-latency communication, and increased throughput in the event of traffic congestion. Radio frames used in communication methods compliant with this standard can be referred to as UHR (Ultra-Reliable PPDU). PPDU is an abbreviation for PLCP Protocol Data Unit, and PLCP is an abbreviation for Physical Layer Convergence Protocol. Note that names such as UHR and IEEE 802.11bn may be changed to other names after the standard is finalized. The scope of this specification and the appended claims can be applied to all communication devices using standards that are successors to the IEEE 802.11be standard. Communication devices can support at least one of the legacy standards that preceded the IEEE 802.11bn standard. Legacy standards include, for example, the IEEE 802.11a / b / g / n / ac / ax / be standards. Communication devices can support other communication standards such as Bluetooth®, NFC, UWB, ZigBee, and MBOA. Note that UWB is an abbreviation for Ultra Wide Band, and MBOA is an abbreviation for MultiBand OFDM Alliance. Furthermore, NFC is an abbreviation for Near Field Communication. UWB includes Wireless USB, Wireless 1394, and WiNET. Communication devices can also support communication standards such as wired LANs. AP 101 is, for example, a wireless LAN router or a personal computer (PC), but is not limited to these. AP 101 can be an information processing device, such as a radio chip capable of performing wireless communication conforming to the IEEE 802.11bn standard. STA 102 is, for example, a camera, tablet computer, smartphone, PC, mobile phone, camcorder, or head-mounted device, but is not limited thereto. STA 102 can be an information processing device, such as a radio chip capable of performing wireless communication conforming to the IEEE 802.11bn standard.

[0051] Communication devices can transmit / receive radio signals using frequency bands such as the 2.4-GHz band, 3.6-GHz band, 5-GHz band, 6-GHz band, and the 45-GHz and 60-GHz bands known as millimeter wave bands. The frequency bands used by communication devices are not limited to these and may include, for example, the Sub-1 GHz band. Communication devices can perform communication using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidths used by communication devices are not limited to these and may include, for example, 240 MHz and 4 MHz. Note that in the IEEE 802.11 standard family, a frequency channel using a 20-MHz bandwidth is defined as a basic channel within a frequency band such as the 2.4-GHz band, 5-GHz band, or 6-GHz band. Furthermore, this standard defines multiple available channels in each of the 2.4-GHz, 5-GHz, and 6-GHz frequency bands. Note that in this standard, communication devices can combine a given channel with another adjacent channel. Combining a given channel with another adjacent channel can be called channel bonding. A bundle of channels formed by one, two, or more adjacent channels can be called a communication link (link). That is, a link formed by two channels, each with a bandwidth of 20-MHz, can use a bandwidth of 40-MHz. In the IEEE 802.11be standard, 320 MHz is planned to be defined as the maximum bandwidth usable in a link. Signals transmitted within this bandwidth can be continuous or discontinuous on the frequency axis. Note that AP 101 and STA 102 can be AP MLD (Multi-Link Device) and STA MLD, respectively, each supporting multi-link operation for performing communication by simultaneously establishing multiple links.

[0052] When a communication device transmits a signal using a link established with another communication device, it performs carrier sense to determine whether transmission is possible. Carrier sense is the operation by which a communication device determines the presence or absence of a signal on a channel it intends to transmit on. For example, the communication device measures the strength of a signal received on the channel (received signal strength), and if the received signal strength exceeds a predetermined threshold, then it determines that a signal exists (physical carrier sense). Received signal strength can also be referred to as a Received Signal Strength Indicator (RSSI). Furthermore, the communication device can determine the presence or absence of a signal based on information such as a duration field included in the signal received on the channel (virtual carrier sense). For example, the communication device stores the time period indicated by the duration field included in the received signal as a Network Assignment Vector (NAV) in itself. The communication device can treat the stored NAV as a time period during which it prohibits the transmission of radio frames from its own device. In this embodiment, the operation by which the communication device sets a time period during which it does not perform transmission based on information such as the duration field of the received signal will be referred to hereinafter as the NAV setting operation. That is, the communication device determines that a signal exists on the channel until the NAV set for that channel expires. As described above, the communication device determines whether a signal exists on the channel based on the results of performing physical carrier sensing and virtual carrier sensing. If a signal is determined to exist on the channel, the communication device can determine that transmission is impossible. In this case, the channel state can be referred to as a busy state. On the other hand, a state in which no signal is detected on the channel through carrier sensing and no NAV is set can be referred to as an idle state. If the channel is in an idle state, the communication device can determine that transmission is possible.

[0053] For example, when a communication device performs communication using a link with a bandwidth of 160 MHz, it can determine whether transmission is possible by using only the first channel with a bandwidth of 20 MHz included in that link. This first channel can be referred to as the primary channel (PCH). For instance, in the IEEE 802.11 standard series, it is described that if transmission is possible as a result of carrier sensing on the PCH for a predetermined period, the communication device can begin transmission. The predetermined period is determined by the inter-frame space (IFS) for each access category used to classify the type of communication traffic and a random number (backoff counter) randomly determined from a predetermined range. That is, if the PCH is determined to be idle for that predetermined period, the communication device acquires the right to perform transmission using that link. At this time, if a second channel other than the PCH is idle during the PIFS period immediately preceding the start of transmission, the communication device can use that idle channel and the PCH to perform transmission through channel binding. PIFS is an abbreviation for Priority InterFrame Space. If, as a result of carrier sensing on the PCH, it is determined that transmission is impossible, the communication device can postpone transmission even if another channel included in the same link is idle. Note that each second channel forming a link, besides the PCH, can also be referred to as a secondary channel (SCH) or a non-primary channel (NPCH).

[0054] In a communication device, if a signal is received on a given channel while simultaneously transmitting on another channel (e.g., an adjacent channel) at a frequency close to that channel, the received signal may not be properly received. For example, suppose a communication device can simultaneously perform transmission and reception processing using different channels. If the communication device uses an adjacent channel to transmit a signal while receiving a signal on a given channel, the power of the transmitted signal may leak into the channel receiving the signal, thus interfering with the received signal. Generally, since the power caused by the leakage of the transmitted signal is much greater than the power of the received signal, it is assumed that the received signal cannot be properly received. To avoid this situation, the IEEE 802.11 standard series provides a mechanism to prevent another communication device from transmitting a signal to a communication device using a channel adjacent to the PCH while the communication device is transmitting a signal. That is, it defines the PCH as a channel jointly used between communication devices to determine whether transmission is possible, and when one communication device performs transmission using the PCH, the other communication device will not perform transmission even if the other channel is idle. Therefore, when a communication device is transmitting a signal and the PCH is in use, another communication device does not use a channel adjacent to the PCH to transmit a signal, thereby preventing the communication device from receiving signals on an adjacent channel. Thus, the problem of interference caused by power leakage between channels can be solved.

[0055] However, when the PCH is in a busy state and another channel (NPCH) in an idle state is not used, this may hinder the efficient use of frequency resources across the entire link. Figure 2A An example timing diagram is shown when STA 102 sends data to AP 101. Figure 2A In this configuration, STA 102 performs carrier sensing on the PCH to confirm that the PCH is idle, and then transmits data using the PCH with a bandwidth of 20-MHz. In this case, for example, even if the seven NPCHs other than the PCH are idle, another communication device is not permitted to use these NPCHs to perform communication. Figure 2B Another example of a timing diagram is shown when STA 102 sends data to AP101. Figure 2B In this context, when STA 102 performs carrier sensing on the PCH, the PCH is detected by another network geographically nearby (e.g., Figure 1Network 113 in the network is used. In this case, since the PCH is determined to be busy during carrier sensing performed by STA 102, for example, even if the seven NPCHs other than the PCH are idle, STA 102 is not permitted to use these NPCHs to communicate with AP 101. However, since AP 101 is not performing transmission at this time, AP 101 can properly receive the signals transmitted by STA 102 even if STA 102 uses NPCHs to send signals to AP 101. As described above, if the PCH with a bandwidth of 20-MHz is used by another network, and therefore the remaining NPCHs with a bandwidth of 140-MHz that are idle are not used, then frequency resources cannot be used efficiently.

[0056] In this embodiment, considering the aforementioned problems, a function is provided for performing communication between communication devices using an NPCH (Non-Primary Channel) included in the same link as the PCH when the PCH is used by another communication device, without using the PCH itself. As an example, when the PCH is busy, the communication device sets up a Secondary Primary Channel (SPCH) to acquire the right to transmit using the NPCH. The SPCH includes one or more channels of the NPCH included in the same link as the PCH. If it is determined that the PCH is used by another communication device, the communication device determines whether it is possible to transmit on the SPCH. That is, based on confirming that the SPCH is idle by performing the aforementioned carrier sensing on the SPCH, the communication device determines that it is possible to perform communication using the NPCH. Then, if it is determined that it is possible to transmit on the SPCH, the communication device uses one or more NPCHs including the SPCH to transmit. In this embodiment, the communication method of transmitting using one or more channels including the SPCH without using the PCH will be referred to hereinafter as NPCH access (non-primary channel access). Note that this communication method may be referred to by another name below. For example, this communication method may be referred to as SCA (Secondary Channel Access) below. When a PCH is available, the communication device performs communication using a first communication method that involves communication over a communication link via the PCH and one or more NPCHs. Alternatively, the communication device is configured to perform communication via a second communication method (NPCH Access) when a given additional condition is met, such as when a PCH cannot be used (e.g., NPCHs are not used).

[0057] If it is confirmed that PCH is not in an idle state (PCH is being used by OBSS), such as Figure 2AAs shown, AP 101 and STA 102 can perform NPCH access. On the other hand, it is assumed that STA 102 may be located in a position where it cannot receive signals transmitted from AP 111 or STA 112 with sufficient power, for example, as Figure 1 As shown in the diagram. When STA 102 is in such a position, even if the PCH is used by the OBSS, STA 102 cannot detect the use. Therefore, STA 102 determines that the PCH is not used and attempts to send a signal using the PCH, while AP 101 can decide whether to use NPCH access by detecting signals from AP 111 or STA 112. That is, it is assumed that the result of determining whether to perform NPCH access is inconsistent between AP 101 and STA 102.

[0058] In this embodiment, considering the aforementioned problems, for example, AP 111 sends a radio frame to a communication device in an OBSS (network 103) different from the BSS (network 113) constructed by itself, requesting to occupy a channel set as PCH in that OBSS. This radio frame requests that network 113 constructed by AP 111 occupy one or more channels including the channel used as the PCH of network 103. This radio frame will be referred to below as an occupancy request frame. Upon receiving the occupancy request frame, AP 101 determines whether to permit the occupancy of one or more channels including the PCH and sends a radio frame including the determination result. This radio frame is a response to the occupancy request frame and will be referred to below as an occupancy response frame. The occupancy response frame does not always need to be received by AP 111, but is at least sent in response to the reception of the occupancy request frame. This occupancy response frame is received by STA (e.g., STA 102) in the BSS (e.g., network 103) that has received the request to occupy the PCH. Therefore, it is shared that NPCH access should be performed when communication is conducted in a BSS that has received a request to occupy the PCH, during a period when the channel used as the PCH in that BSS is occupied by an OBSS (the BSS that sent the occupancy request). In one example, assume that AP 101 is located in a position where it can receive an occupancy request frame from AP 111 and STA 102 cannot receive the occupancy request frame. If AP 101 receives the occupancy request frame, it sends an occupancy response frame to its surroundings. STA 102 can use this occupancy response frame to identify that the PCH is occupied by an OBSS (network 113 in this example) and to identify that communication should be conducted via NPCH access.

[0059] The following will describe in detail an example of the configuration and processing procedures of the communication device that performs this type of processing.

[0060] (Device configuration)

[0061] Figure 3An example hardware configuration of a communication device (AP 101, AP 111, STA 102, and STA 112) is shown. The communication device includes a storage unit 301, a control unit 302, a functional unit 303, an input unit 304, an output unit 305, a communication unit 306, and an antenna 307. Note that these are merely examples; the communication device may have... Figure 3 Other components not shown in the diagram, and Figure 3 Some or all of the components shown can be replaced by other components with the same functionality.

[0062] Storage unit 301 includes one or more memories, such as ROM and RAM. Storage unit 301 stores computer programs for performing 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. Note that in addition to memories such as ROM and RAM, storage unit 301 may include 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 301 may include multiple storage media such as memories.

[0063] Control unit 302 includes, for example, one or more processors, such as a CPU and an MPU. Note that CPU is an abbreviation for Central Processing Unit, and MPU is an abbreviation for Micro Processing Unit. Control unit 302 controls the entire communication device by executing a computer program stored in storage unit 301. Note that control unit 302 can control the entire device through cooperation between the computer program stored in storage unit 301 and the operating system. Furthermore, control unit 302 generates data and signals (radio frames) to be transmitted in communication with another communication device. Additionally, control unit 302 may include multiple processors, such as a multi-core processor, and control the entire communication device through these multiple processors.

[0064] Furthermore, control unit 302 controls functional unit 303 to perform wireless communication and predetermined processes such as image capture, printing, or projection. Functional unit 303 includes hardware used by the communication device to perform the predetermined processes. If the communication device is a printer, then functional unit 303 functions as a printing device and, for example, prints image data acquired via communication unit 306. If the communication device is a scanner, then functional unit 303 functions as a reading device and outputs image data generated by scanning to, for example, an external device via communication unit 306. If the communication device is a camera, then functional unit 303 includes an image sensor and a lens and outputs image data captured by the camera to, for example, an external device via communication unit 306.

[0065] Input unit 304 includes, for example, a touch panel, hardware keys, and buttons, and accepts various operations from the user. Output unit 305 includes a display and a speaker, and performs various outputs to the user. In this example, the outputs performed by output unit 305 may include screen display output on the display and audio output from the speaker. Furthermore, output unit 305 may include a vibrator, and information may be output through vibration. Note that both input unit 304 and output unit 305 can be implemented as a single module, such as a touch panel display. Additionally, each of input unit 304 and output unit 305 can be integrated into a communication device, or can be implemented by an external input / output device. In this case, the communication device includes an input / output interface for connecting to the input / output device.

[0066] Communication unit 306 performs control for wireless communication conforming to the IEEE 802.11bn standard. In addition to the IEEE 802.11bn standard, communication unit 306 can also control wireless communication conforming to another IEEE 802.11 standard family or control wired communication via a wired LAN, etc. Communication unit 306 controls antenna 307 to transmit / receive signals for wireless communication generated by control unit 302. For example, the communication device transmits data such as image data, document data, or video data to a partner device via communication unit 306. Note that if the communication device supports NFC or Bluetooth standards in addition to the IEEE 802.11bn standard, then communication unit 306 can control wireless communication conforming to these communication standards. If the communication device can perform wireless communication conforming to multiple communication standards, then communication units and antennas supporting the corresponding communication standards can be prepared separately.

[0067] Antenna 307 is, for example, an antenna configured to detect and transmit radio waves in the 2.4-GHz, 5-GHz, and 6-GHz frequency bands. Note that antenna 307 can be configured to perform communication within the same frequency band. In this case, antenna 307 can be, for example, a multi-band antenna capable of performing communication in multiple frequency bands. Figure 3 An example of a communication device including two antennas is shown, but one antenna or three or more antennas can be used. Note that if the communication device includes multiple antennas, it can include communication units 306 corresponding to each antenna. Note that antenna 307 can be prepared separately from communication unit 306, or it can be formed as a module combined with communication unit 306.

[0068] Figure 4 This is a block diagram illustrating an example functional configuration of communication devices (AP 101, AP 111, STA 102, and STA 112). The communication devices include, for example, a PCH communication control unit 401, an NPCH communication control unit 402, and a communication control unit 403. Note that these functions can be implemented when, for example, control unit 302 executes a program stored in the storage unit 301 of the communication devices. This is merely an example, and dedicated hardware may be prepared to implement each function. Note that... Figure 4 The components shown are merely examples, and communication devices may include components other than those shown. Furthermore, Figure 4 The two or more functional blocks shown can be implemented as one functional block, or one functional block can be divided into two or more functional blocks.

[0069] PCH communication control unit 401 performs communication by establishing a link with STA to use one or more channels including PCH. For example, PCH communication control unit 401 receives radio frames from a partner device connected to its own device and has acquired the right to transmit on PCH, or transmits radio frames to a partner device by acquiring the right to transmit on PCH. When PCH is used by another device and it is not possible to use PCH, NPCH communication control unit 402 performs communication using NPCH access. That is, NPCH communication control unit 402 performs communication using NPCH access when, for example, OBSS is detected using PCH or when NPCH access is determined based on an occupancy request frame or occupancy response frame (described later). For example, NPCH communication control unit 402 confirms that SPCH is idle, acquires the right to transmit on NPCH, and transmits radio frames using one or more NPCH channels including SPCH without using PCH. Furthermore, NPCH communication control unit 402 receives radio frames transmitted from partner devices connected to its own device via NPCH access. For example, communication control unit 403 controls which of PCH communication control unit 401 and NPCH communication control unit 402 is used to perform communication. For example, the communication control unit 403 determines whether the PCH is occupied by the OBSS based on an occupancy request frame or an occupancy response frame, and if the PCH is not occupied, then controls are performed to use the PCH communication control unit 401 to perform communication. Furthermore, for example, during the period when the PCH is occupied by the OBSS, the communication control unit 403 performs controls to use the NPCH communication control unit 402 to perform communication.

[0070] (The process of communication processing)

[0071] Then, refer to Figure 5 An example describing the communication processing performed in a wireless communication system. Note that... Figure 5 Assume that AP 101 is located where it can receive and decode radio frames from AP 111, and STA 102 is located where it cannot receive and decode those radio frames. Figure 1 As shown. In Figure 5 It is also assumed that AP 101 and STA 102 can use the first channel (CH1) as the PCH, and AP 111 and STA 112 can use CH1 as the PCH or NPCH.

[0072] exist Figure 5In this scenario, assume that AP 101, STA 102, AP 111, and STA 112 do not use CH1 (F501 to F504). Note that since PCH is not used or occupied by OBSS, AP 101 and STA 102 do not use NPCH access and acquire access rights on PCH to transmit radio frames. Then, if AP 101 and STA 102 acquire access rights on PCH, they can use CH2 as NPCH if the second channel (CH2) is not used. Note that... Figure 5 The diagram shows the states in F501 and F502 where AP 101 and STA 102 can use CH2 in addition to CH1.

[0073] In this state, if, for example, data to be transmitted via a channel is generated in STA 112, then STA 112 sends a channel occupancy request frame (F505). The channel occupancy request frame includes, for example, information specifying one or more channels to be occupied, and information indicating the length of the time the channel will be occupied. Note that the information indicating the length of the time the channel will be occupied can be information used to cause surrounding APs or STAs to set NAV, similar to a regular Request to Send (RTS) frame or Clear to Send (CTS) frame. The channel occupancy request frame can also include a duration field, like an RTS or CTS frame, and this duration field can indicate the length of the time the channel will be occupied. In the following description, unless otherwise stated, the information indicating the length of the time the channel will be occupied in the channel occupancy request frame can also be information used to set NAV, and the length of this period can be indicated by the duration field in the frame. When a channel occupancy request frame is sent on a channel, the information specifying the channel to be occupied can be implicitly provided, and it is not necessary to explicitly indicate the channel to be occupied. For example, a channel occupancy request frame can be sent on all channels for which occupancy is requested, and in this case, the information indicating the channels for which occupancy is requested does not need to be included in the frame. When configured to always send occupancy request frames on some of the channels to be occupied, if multiple channels exist to be occupied, then channels other than the channel on which the frame is sent can be represented as channels to be occupied. For example, if occupancy is requested on the OBSS PCH, the occupancy request frame can be sent on the OBSS PCH and can include information indicating the channels to be occupied other than the PCH. Alternatively, information indicating a list of the channels to be occupied, including the channel on which the occupancy request frame is sent, can be included in the frame. Figure 5In this scenario, STA 112 requests the occupancy of CH1 and sends an occupancy request frame on CH1. This occupancy request frame does not need to include information related to CH1, but rather serves as information about the channel to be occupied. The channel to be occupied can be represented by a list of channel numbers or other information such as bandwidth.

[0074] Upon receiving an occupancy request frame, AP 111 sends an occupancy request frame (F506) to the communication device (AP 101 in this example) in the OBSS (network 103 in this example) seen from AP 111. The occupancy request frame may include information indicating that the channel and time period to be occupied are the same as those indicated by the occupancy request frame sent by STA 112. Note that this is merely an example, and if there is data to be transmitted in AP 111, the channel or time period to be occupied may be increased, and the occupancy request frames in F505 and F506 may include different information regarding the channel and time period to be occupied. Furthermore, if there is data to be transmitted via the occupied channel, AP 111 may spontaneously send an occupancy request frame without receiving an occupancy request frame from STA 112. In this case, the occupancy request frame includes information specifying one or more channels to be occupied and information indicating the length of the time period during which the channel is occupied, which has been determined based on factors such as the size of the target data to be transmitted. Note that, for example, AP 111 may send an occupancy request frame only when requesting occupancy (use) of the PCH in OBSS (network 103), or it may send an occupancy request frame regardless of the channel being requested.

[0075] Note that when AP 111 sends an occupancy request frame, CH1 is busy, and therefore AP 101 cannot use CH1 and CH2. On the other hand, if AP 101 cannot detect the signal from STA 112 with sufficient power, then AP 101 can use CH1 (and CH2) when STA 112 sends an occupancy request frame. Furthermore, STA 102 does not detect radio frames from AP 111 and STA 112 with sufficient power, and can use CH1 (and CH2) when AP 111 and STA 112 send occupancy request frames.

[0076] Upon receiving an occupancy request frame from AP 111 in the OBSS, AP 101 determines whether to grant occupancy of the received CH1 or the channel specified in the frame. AP 101 then sends an occupancy response frame (F507) including the determination result. This occupancy response frame can be, for example, a frame indicating that AP 111 is permitted to occupy the channel specified in the occupancy request frame. The occupancy response frame can also be a frame instructing a STA (STA 102 in this example) belonging to network 103 constructed by AP 101 to perform NPCH access. That is, AP 111 determines the permission to occupy the channel by receiving the occupancy response frame, and STA 102 can interpret the same occupancy response frame as an instruction to use NPCH access. The occupancy response frame can include, for example, information indicating the channel to be permitted and information indicating the time period during which the channel occupancy is permitted. The information indicating the time period during which the channel occupancy is permitted can also be information indicating a time period set as NAV by surrounding APs or STAs, such as a regular RTS frame or CTS frame. Furthermore, the occupancy response frame can include a duration field, similar to an RTS or CTS frame, and this duration field can indicate the length of the period during which the channel occupancy is permitted. In the following description, unless otherwise stated, the information in the occupancy response frame indicating the length of the period during which the channel is occupied can also be information used to set the NAV, and the length of this period can be indicated by the duration field in the frame. This allows AP 111 to identify the possibility of performing communication by occupying a specified channel during a specified period. Additionally, STA 102 can identify that it should perform NPCH access on an unoccupied channel during a specified period. Note that AP 101 can send a frame indicating that NPCH access should be used to STA 102 separately from the occupancy response frame for AP 111. The occupancy response frame can be a multicast frame, including portions storing data for AP 111 and portions storing data for the STA (STA 102 in this example) for connection. In the case of control being performed via different radio frames, detailed information can be provided separately to STA 102 and AP 111 in the OBSS. On the other hand, when control is performed through a single radio frame, the number of radio frames to be sent / received for control can be reduced, thereby improving communication efficiency.

[0077] Note that the information notified from AP 101 to the STA in the BSS (STA 102 in this example) may include, for example, information indicating the SPCH. However, if the SPCH is determined in advance between AP 101 and STA 102 and the channel is not occupied, then it is not necessary to include information indicating the SPCH. This information may instruct the STA to prohibit the transmission of radio frames on any channel. For example, if the channels to be occupied in the OBSS include all channels available in BSS 103, it may instruct the prohibition of radio frame transmission. The information notified from AP 101 to the STA in the BSS (STA 102 in this example) may include information indicating the length of the period during which NPCH access should be performed or the length of the period during which radio frame transmission is prohibited. By specifying the length of this period, it becomes unnecessary to send notifications to terminate NPCH access or cancel the prohibition of radio frame transmission, and thus, a decrease in communication efficiency due to increased control communication can be prevented. The specified period length may be equal to, for example, the period length during which the AP in the OBSS requests to occupy the channel in F506, but the invention is not limited thereto. For example, as described later, the STA can be notified of a time period length obtained by adding a predetermined time period length, such as the duration of the SIFS (Short IFS) and occupancy response frames sent from AP 111 to STA 112, to a specified time period length. The occupancy permitted time period notified to the AP in the OBSS can be equal to or different from the time period for which NPCH access should be performed or the time period for which the transmission of radio frames is prohibited, notified to the STA in the BSS. For example, different time period lengths can be set, taking into account propagation delay, processing time, etc.

[0078] Upon receiving a frame from AP 101, STA 102 initiates control to transition to a state where it performs NPCH access for transmitting radio frames using NPCHs without transmitting radio frames on the PCH (F508 and F509). After transitioning to this state, for example, if the SPCH is designated as CH2, STA 102 can confirm that CH2 is idle and transmit data using one or more NPCHs including CH2. Subsequently, after the period specified in the occupancy response frame in F507 has elapsed, STA 102 initiates control to return to the state of performing communication using the PCH (F510). Similarly, after sending an occupancy response frame (F507), AP 101 initiates control to transition to a state where it performs NPCH access for transmitting radio frames using NPCHs without transmitting radio frames on the PCH (F511 and F512). After the period specified in the occupancy response frame in F507 has elapsed, AP 101 initiates control to return to the state of performing communication using the PCH (F513).

[0079] On the other hand, if the occupancy of CH1 is permitted in the occupancy response frame sent from AP 101 in F507, then AP 111 sends an occupancy response frame (F514) to STA 112 indicating that the occupancy of CH1 is permitted. This sets the state of CH1 being occupied in network 113, and AP 111 and STA 112 use CH1 to perform data communication during the period when CH1 is occupied (F515 and F516). Afterwards, when the period of CH1 occupancy has elapsed, AP 111 and STA 112 transition to a state where CH1 is not occupied. This state is one where CH1 is not occupied and it is possible to transmit radio frames while CH1 is idle (F517 and F518). Note that, as an example, an RTS frame can be used as an occupancy request frame sent from STA 112 to AP 111 in F505. For example, STA 112 sends RTS frames on all channels requesting occupancy. Then, AP 111 can specify the channel from which it has received an RTS frame from STA 112 and send an occupancy request frame to AP 101, including information representing the specified channel as information indicating the requested channel occupancy. Then, when channel occupancy is granted, AP 111 sends a CTS frame on each granted channel. This allows STA 112 to adjust channel usage between BSSs while maintaining its normal configuration. Note that the list of requested channels is included in the RTS frame, and the list of granted channels is included in the CTS frame; these frames can then be sent / received on a single channel.

[0080] (The process performed by the AP)

[0081] Then, refer to Figure 6A , Figure 6B , Figure 7A , Figure 7B , Figure 8A , Figure 8B and Figure 9 The operation of the APs (AP 101 and AP 111) is described. For example, this process can be implemented by the control unit 302 executing a program stored in the storage unit 301, or as a processing function in the communication unit 306. The AP can begin this process when the wireless LAN function is enabled by powering on. First, the AP sets up the operating channels (PCH and one or more NPCHs) (step S601). This setting can be performed, for example, by user input, or automatically based on information such as the congestion status of the multiple channels available to the AP. Afterward, communication is performed on the set PCH and one or more NPCHs within the network constructed by the AP.

[0082] The AP waits to receive a radio frame on one or more channels including the PCH (step S602). At this time, without using NPCH access, when receiving a signal from a STA in the BSS, the AP always uses a channel including the PCH to receive the radio frame. On the other hand, in the OBSS, a channel different from the PCH set in step S601 can also be used as the PCH. Therefore, a radio frame received by the AP on a channel excluding the PCH is a radio frame from the OBSS. At this time, if an occupancy request frame is transmitted in parallel on all channels to be occupied and is received on a channel excluding the PCH, the channel other than the PCH is occupied. That is, if an occupancy request frame is transmitted on all channels to be occupied, the AP can determine that the radio frame received on a channel excluding the PCH is not a frame destined for the device and the PCH is not occupied. Therefore, if the AP receives a radio frame on a channel excluding the PCH ("No" in step S602), the AP moves the processing to step S608 without performing any reception-related processing. Note that if an occupancy request frame requesting the use of multiple channels is sent on one channel, the AP can decode the frame considering the possibility of a PCH occupancy request on a channel other than the PCH. Then, if the AP determines that there is no PCH occupancy request in the frame, the AP can proceed to step S608. Note that, for example, even if the PCH in the BSS (network 113) is CH2, if the PCH in the OBSS (network 103) is CH1 and AP 111 requests the use of CH1, AP 111 can also send an occupancy request frame on CH1. That is, an occupancy request frame can be sent on the PCH in the network that received the occupancy request. In this case, if the PCH occupancy is requested, then AP 101 will always receive an occupancy request frame on the PCH. Therefore, during periods when NPCH access is not performed, radio frames received on channels that do not include the PCH do not request PCH occupancy, and therefore the AP can ignore such radio frames.

[0083] If the AP receives a radio frame on one or more channels including the PCH ("Yes" in step S602), then it determines whether the frame is an occupancy request frame from a STA in the BSS (step S603). If the AP receives an occupancy request frame from a STA in the BSS ("Yes" in step S603), then it moves the processing to step S604. The processing in step S604 is, for example, in... Figure 5The processing of AP 111 receiving an occupancy request frame in F505. Details of this processing will be described later. If the received frame is not an occupancy request frame from a STA in the BSS ("No" in step S603), then the AP determines whether the frame is an occupancy request frame from an AP in the OBSS (step S604). If the AP receives an occupancy request frame from an AP in the OBSS ("Yes" in step S604), then it moves the processing to step S606. The processing in step S606 is, for example, in... Figure 5 The processing of AP 101 receiving an occupancy request frame from AP 111 in F506. Details of this processing will be described later. If the received frame is not an occupancy request frame from an AP in the OBSS (No in step S604), then the AP performs the processing corresponding to that frame (step S607). This processing is for frames related to regular communication (such as ordinary data and control frames) and is irrelevant to this embodiment, and its detailed description will be omitted.

[0084] Reference Figure 7A and Figure 7BThe process in step S604 is described. If the AP receives an occupancy request frame from a STA in the BSS ("Yes" in step S603), it determines whether to grant channel occupancy (step S701). For example, the AP determines whether to grant channel occupancy based on the congestion status of the BSS and characteristics of the traffic to be transmitted, such as throughput and tolerable delay. If the AP determines that channel occupancy is not permitted ("No" in step S701), it sends an occupancy response frame indicating a refusal to grant channel occupancy to the STA, which is the source of the occupancy request frame (step S709), and ends the process. Note that if the AP determines that channel occupancy is not permitted, it may not respond. In this case, if the STA does not receive a response within a predetermined time period, it may determine that occupancy is not permitted. On the other hand, if the AP determines that channel occupancy is permitted ("Yes" in step S701), it determines whether the requested channel includes the PCH of the OBSS (step S702). If the channel to be occupied includes the OBSS's PCH ("Yes" in step S702), then the AP sends an occupancy request frame to the APs in the OBSS (step S703). For example, the AP can send the occupancy request frame on all channels to be occupied, or only on the OBSS's PCH. In one example, the AP can specify the OBSS's PCH by decoding a radio frame (e.g., a beacon frame) from an AP in the OBSS. The AP can obtain information about the OBSS's PCH by performing prior (wired or wireless) communication with the APs in the OBSS. Note that if the APs in the OBSS are configured to decode radio frames on channels other than the OBSS's PCH, then the AP can send the occupancy request frame on at least one of the channels available in the OBSS.

[0085] After sending a channel occupancy request, the AP waits to receive an occupancy response frame from the AP in the OBSS (step S704). Then, if the AP receives an occupancy response frame indicating a rejection of the channel occupancy, or if the AP does not receive a channel occupancy response frame within a predetermined time period ("No" in step S704), the AP specifies that the occupancy of the channel is not permitted. Then, the AP sends an occupancy response frame indicating a rejection of the channel occupancy to the STA, which is the source of the occupancy request frame received in step S603 (step S709), and ends the process. On the other hand, if the AP receives an occupancy response frame indicating permission to occupy the channel ("Yes" in step S704), the AP sends an occupancy response frame indicating permission to occupy the channel to the STA, which is the source of the occupancy request frame received in step S603 (step S705). Then, the AP waits to receive a frame from the STA using the permitted channel (step S706). If the AP receives the frame ("Yes" in step S706), it performs the processing corresponding to the frame (step S707). The AP continues frame reception processing (steps S706 and S707) until the channel occupancy period expires ("No" in step S708), and terminates processing when the occupancy period expires ("Yes" in step S708). Figure 7A and Figure 7B After the process shown in the diagram ends, the process moves to... Figure 6B Step S608 in the process.

[0086] Then, refer to Figure 8A and Figure 8BThe process in step S606 is described. If the AP receives an occupancy request frame from an AP in the OBSS ("Yes" in step S605), it determines whether to grant channel occupancy (step S801). For example, the AP may determine whether to grant channel occupancy based on the congestion status from the BSS and characteristics of the traffic to be transmitted, such as throughput and tolerable latency. If the AP determines that channel occupancy is not permitted ("No" in step S801), it sends an occupancy response frame indicating a refusal to grant channel occupancy to the AP in the OBSS, which is the source of the occupancy request frame (step S810), and ends the process. In this case, the AP may send a notification to the STA in the BSS separately from the occupancy response frame, indicating that NPCH access should not be used or that the transmission of radio frames should not be prohibited, but it is not necessary to send such a notification. That is, if the STA interprets the occupancy response frame as an indication to use NPCH access or prohibit the transmission of radio frames, regardless of the content of the frame, then the AP may send such a separate notification to the STA. On the other hand, if the STA decides to control by confirming the content of the occupancy response frame, then such a notification is not necessarily required. Furthermore, when it is determined whether to use NPCH access or prohibit the transmission of radio frames, if the determination result is notified to the STA separately from the occupancy response frame, then the STA can be notified to use NPCH access, etc., based on the absence of such notification.

[0087] If the AP determines that a permitted channel is occupied ("Yes" in step S801), then it determines whether the requested channel includes all channels available from the BSS (step S802). That is, the AP determines whether there are unoccupied channels that can be used continuously. If there are unoccupied channels, then the AP sends a radio frame to the STAs in the BSS instructing them to transition to a state where NPCH access should be performed (step S803). Furthermore, the AP sends an occupancy response frame indicating permission to occupy the channel to the AP in the OBSS, which is the source of the occupancy request frame (step S803). Note that the information indicating the transition from the STA in the BSS to a state where NPCH access should be performed can be included in the occupancy response frame, but this information can be sent in a different radio frame. Note that the information indicating the transition to a state where NPCH access should be performed includes information indicating the SPCH selected from unoccupied channels. Furthermore, this information includes information indicating the duration of the state where NPCH access should be performed. This duration corresponds to the occupancy time of the PCH from the BSS by the OBSS, but can be set to a longer or shorter time than that occupancy time.

[0088] Afterwards, communication using NPCH access is performed until the channel occupancy period of OBSS expires (No in step S809). That is, the AP waits for a frame on the NPCH including the SPCH (step S804). Then, if the AP receives a frame on the NPCH including the SPCH (Yes in step S804), it performs the processing corresponding to the received frame (step S805) and proceeds to step S806. If the AP does not receive a frame on the NPCH including the SPCH (No in step S804), it proceeds to step S806 without performing the processing in step S805. In step S806, the AP determines whether a target frame has been generated. Then, if a target frame has been generated (Yes in step S806), the AP detects that the SPCH is idle (Yes in step S807) and then transmits the target frame on the NPCH including the SPCH (step S808). On the other hand, if there is no target frame to send ("No" in step S806) or the SPCH is not idle ("No" in step S807), then the processing in step S808 is not performed. Before the OBSS channel occupancy period expires ("No" in step S809), the processing returns to step S804. Note that... Figure 8A and Figure 8B An example is shown where transmit processing is performed after receive processing, but the order can be reversed. Subsequently, if the OBSS channel occupancy period expires ("Yes" in step S809), then... Figure 8A and Figure 8B The processing shown is now complete.

[0089] Returning to step S802, if there is no unclaimed channel ("No" in step S802), the AP sends an occupancy response frame indicating permission to occupy the channel to the AP in the OBSS (step S811). Additionally, the AP sends information instructing the STA in the BSS to prohibit the transmission of radio frames (step S811). Note that the information instructing the STA in the BSS to prohibit the transmission of radio frames can be included in the occupancy response frame, but this information can be sent in a different radio frame. Afterward, the AP remains in standby mode without performing communication until the channel occupancy period in the OBSS expires (step S812), and the process ends when the occupancy period expires ("Yes" in step S812). Figure 8A and Figure 8B After the process shown in the diagram ends, the process moves to... Figure 6B Step S608.

[0090] Return to reference Figure 6A and Figure 6BThe AP (separate from the transmission target frame generated in the process caused by radio frames sent from STAs in the BSS or APs in the OBSS) determines whether a transmission target frame has been generated (step S608). If no such transmission target frame exists ("No" in step S608), then as long as the wireless LAN function is not disabled ("No" in step S613), the AP returns the process to step S602 and repeats the process. Figure 6A and Figure 6B The process is as shown in the diagram. On the other hand, if a target frame exists ("Yes" in step S608), the AP determines whether it should occupy the channel to transmit the frame (step S609). The AP performs this determination based on the tolerable delay of the target frame and the requested throughput. In one example, if the tolerable delay is equal to or shorter than a predetermined time or the requested throughput exceeds a predetermined value, the AP determines that it is necessary to occupy the channel. If the AP determines that it is not necessary to occupy the channel ("No" in step S609), the AP confirms that the PCH is idle ("Yes" in step S611) and uses the idle channel including the PCH to transmit the target frame (step S612). On the other hand, if the AP cannot confirm that the PCH is idle ("No" in step S611), the AP does not transmit the target frame. Then, as long as the wireless LAN function is not disabled ("No" in step S613), the AP returns to step S602 and repeats the process. Figure 6A and Figure 6B The process is shown in the diagram. If the AP determines that it is necessary to occupy the channel ("Yes" in step S609), then the AP performs the process in step S610.

[0091] Reference Figure 9 Describe the process in step S610. This process is similar to, for example... Figure 5The processing corresponds to when AP 111 determines that it has generated a transmission target frame in its own device and sends the occupancy request frame F506 if it has not received the occupancy request frame F505 from STA 112. The AP sends the occupancy request frame to the AP in the OBSS to occupy the channel (step S901). Note that if occupancy of the PCH in the OBSS is not requested, the AP can use the RTS / CTS mechanism instead of sending the occupancy request frame to occupy the channel. After sending the occupancy request frame, the AP determines whether it has received an occupancy response frame from the AP in the OBSS indicating permission to occupy the channel (step S902). If the AP receives an occupancy response frame indicating rejection of the channel occupancy, or if the AP does not receive an occupancy response frame within a predetermined time period ("No" in step S902), then the AP specifies that the channel cannot be occupied and ends the processing without sending a radio frame. On the other hand, if the AP receives an occupancy response frame from the AP in the BSS indicating permission to occupy the channel ("Yes" in step S902), then the AP sends an occupancy response frame indicating permission to occupy the channel to the STA in the BSS (step S903). Note that the occupancy response frame in step S903 only needs to be information indicating that the channel is occupied for the AP to transmit a radio frame and that the STA is prohibited from transmitting radio frames during the occupancy period, and can be a frame other than an occupancy response frame. After the occupancy response frame is sent, the AP transmits the target radio frame on the permitted occupied channel (step S904) until the channel occupancy period expires (when it is determined to be "No" in step S905). After the channel occupancy period expires ("Yes" in step S905), the AP returns to processing. Figure 6B Step S613.

[0092] (The process performed by STA)

[0093] Then, refer to Figure 10A , Figure 10B , Figure 10C , Figure 11 , Figure 12 and Figure 13The operation of the STAs (STA 102 and STA 112) is described. For example, this process can be implemented by the control unit 302 executing a program stored in the storage unit 301, or as a processing function in the communication unit 306. The STA can begin this process when the wireless LAN function is enabled by powering on. First, the STA sets the operating channel (PCH and one or more NPCHs) (step S1001). For example, this setting can be determined based on AP search results. Alternatively, this setting can be performed by user input. In one example, the STA searches for APs, and the choice of which AP to connect to from the search results is selected by user operation, thus determining the operating channel set by the AP. The AP can be notified that the user in the STA has selected the specified operating channel, and the setting can be performed to use the operating channel in the AP. Afterward, in the network joined by the STA, the STA performs communication on the set PCH and one or more NPCHs.

[0094] The STA waits to receive a radio frame on one or more channels including the PCH (step S1002). If the STA does not receive a radio frame on a channel including the PCH ("No" in step S1002), it proceeds to step S1010. Note that if the STA receives a radio frame from the AP in the OBSS or from the STA on a channel including the PCH, it can proceed to step S1010. On the other hand, if the STA receives a radio frame on a channel including the PCH (from the AP in the BSS) ("Yes" in step S1002), it switches the process to be performed based on the type of the frame. That is, if the STA determines that the received frame is an occupancy response frame from the AP in the BSS indicating permission to occupy the channel ("Yes" in step S1003), the STA performs the process in step S1004. The process in step S1004 will be described later. On the other hand, if the STA determines that the received frame is an occupancy response frame from the AP in the BSS indicating a transition to a state where NPCH access should be performed ("No" in step S1003 and "Yes" in step S1005), then the STA performs the process in step S1006. The process in step S1006 will be described later. If the STA determines that the received frame is an occupancy response frame from the AP in the BSS indicating a prohibition on transmission ("No" in step S1003, "No" in step S1005, and "Yes" in step S1007), then the STA stands still until the channel occupancy period of the OBSS expires (step S1008). Then, if the channel occupancy period of the OBSS expires ("Yes" in step S1008), then the STA moves the process to step S1010. Alternatively, if the STA determines that the received frame is another frame ("No" in step S1003, "No" in step S1005, and "No" in step S1007), then the STA performs the processing corresponding to that frame (step S1009) and moves the processing to step S1010. This processing is for frames related to regular communication (such as ordinary data and control frames) and is irrelevant to this embodiment, and its detailed description will be omitted.

[0095] Reference Figure 11 Describe the process in step S1004. This process is related to... Figure 5 The corresponding processing occurs when STA 112 receives the occupancy response frame in F514 without sending the occupancy request frame in F505. That is, Figure 11The process shown is the process when a target frame exists in an AP within the BSS and the channel is reserved for transmission by that AP. After receiving a reservation response frame from the AP within the BSS indicating permission to reserve the channel ("Yes" in step S1003), the STA waits on the reserved channel for the frame from the AP within the BSS (step S1101). After receiving the frame ("Yes" in step S1101), the STA performs the processing corresponding to the received frame (step S1102). The STA repeats the processes in steps S1101 and S1102 until the channel reservation period expires (step S1103). Note that during the channel reservation period, the STA can send acknowledgments (ACKs), data, etc., instead of the AP. If the channel reservation period expires ("Yes" in step S1103), the STA terminates. Figure 11 The process shown is to move the process to Figures 10A to 10C Step S1010.

[0096] Next, we will refer to Figure 12 Describe the process in step S1006. This process is related to... Figure 5 The process corresponds to when STA 102 receives the occupancy response frame in F507. The STA waits for the frame on one or more NPCHs including the SPCH (step S1201). Then, upon receiving the frame ("Yes" in step S1201), the STA performs the processing corresponding to that frame (step S1202). Furthermore, the STA determines whether a target frame exists (step S1203). If a target frame exists ("Yes" in step S1203), the STA confirms that the SPCH is idle ("Yes" in step S1204) and transmits the frame on one or more NPCHs including the SPCH (step S1205). Note that... Figure 12 An example is shown where the transmission process is performed after the reception process, but the order can be reversed. That is, the STA can perform the reception process in steps S1201 and S1202 when a frame is received, and the transmission process in steps S1203 to S1205 when a target frame is present, in any order. The STA repeats the above reception and transmission processes until the channel occupancy period of the OBSS indicated in the occupancy response frame expires (when it is determined to be "No" in step S1206). Then, if the channel occupancy period of the OBSS expires ("Yes" in step S1206), the STA ends. Figure 12 The process shown is to move the process to Figure 10C Step S1010.

[0097] Return to reference Figures 10A to 10CIn step S1010, the STA determines whether a target frame exists. If no such target frame exists ("No" in step S1010), then as long as the wireless LAN function is not disabled ("No" in step S1015), the STA returns to step S1002 and repeats the process. Figures 10A to 10C The process is as shown in the diagram. On the other hand, if a target frame exists ("Yes" in step S1010), the STA determines whether it should occupy the channel to transmit the frame (step S1011). The STA performs this determination based on the tolerable delay of the target frame and the requested throughput. For example, if the tolerable delay is equal to or shorter than a predetermined time, or the requested throughput exceeds a predetermined value, the STA determines that it is necessary to occupy the channel. If the STA determines that it is not necessary to occupy the channel ("No" in step S1011), the STA confirms that the PCH is in an idle state ("Yes" in step S1013) and uses the idle channel including the PCH to transmit the target frame (step S1014). On the other hand, if the STA cannot confirm that the PCH is in an idle state ("No" in step S1013), the STA does not transmit the target frame. Then, as long as the wireless LAN function is not disabled ("No" in step S1015), the STA returns the process to step S1002 and repeats the process. Figures 10A to 10C The process is shown in the diagram. If the STA determines that it is necessary to occupy the channel ("Yes" in step S1011), then the STA performs the process in step S1012.

[0098] Reference Figure 13 Describe the process in step S1012. This process is similar to, for example, in... Figure 5 The process corresponds to when STA 112 determines that a transmission target frame has been generated in its own device and sends the occupancy request frame in F505. If a transmission target frame requesting channel occupancy has been generated, then the STA sends the occupancy request frame to the AP in its own BSS (step S1301). Then, if the STA receives an occupancy response frame from the AP in its own BSS indicating permission to occupy the channel ("Yes" in step S1302), then the STA uses the occupied channel to transmit radio frames (step S1303). Radio frame transmission is performed during the occupancy period indicated in the occupancy response frame (when it is determined to be "No" in step S1304). Note that during this occupancy period, the AP can transmit data and ACK. After the occupancy period expires ("Yes" in step S1304), the STA returns the process to Figure 10C Step S1015.

[0099] As described above, according to this embodiment, frames relating to channel occupancy requests and the granting or denial of such requests are sent / received between APs that respectively construct BSSs, and each AP transmits the content of the frame to its own STA. This allows APs and STAs belonging to each of the multiple BSSs to identify whether the PCH is occupied due to communication in another BSS. As a result, identification regarding whether the PCH can be used in each BSS and whether NPCH access should be used can be shared, thereby enabling efficient communication. Furthermore, channel occupancy is negotiated between BSSs, thereby making it possible to appropriately adjust channel occupancy based on the situation in each BSS.

[0100] Note that the above embodiments have explained examples of granting or denying channel occupancy. However, if occupancy of multiple channels is requested, occupancy of some of these channels can be granted and occupancy of the remaining channels can be denied. For example, if an occupancy request frame is sent on each of the multiple channels for which occupancy is requested, occupancy of only some of these channels can be granted by sending an occupancy response frame on each channel indicating granting or denying occupancy. If an occupancy request frame is sent only on some of the channels for which occupancy is requested (e.g., the PCH of the OBSS), an occupancy response frame can be sent including information indicating at least one of the channels for which occupancy is granted and the channels for which occupancy is denied. Note that the occupancy request frame can indicate information indicating the minimum number of channels (or bandwidth) required. In this case, if occupancy of the minimum required number of channels (or bandwidth) is not granted, occupancy of all channels can be denied. Note that if channel occupancy is denied, the AP and STA can operate to not perform communication on these channels, or can perform contention-based channel access on these channels. That is, if channel occupancy is denied, then the AP and STA do not occupy these channels, but can access these channels through regular Carrier Sense Multiple Access (CSMA) to perform communication.

[0101] (Modified example)

[0102] The above embodiments have illustrated examples of how an AP can occupy channels if it requests channel occupancy and such occupancy is permitted by the AP in the OBSS, but the invention is not limited thereto. For example, an AP can "declare" channel occupancy via an occupancy request frame and perform communication by occupying the channels, regardless of the response from the AP in the OBSS. Figure 14An example of the communication process in this scenario is shown. Note that the term "occupancy request frame" will be used in the following description, but can be replaced by "occupancy declaration frame". For example, if AP 111 receives an occupancy request frame (F505) from STA 112, then it sends an occupancy response frame (F1401). Furthermore, AP 111 sends the occupancy request frame (F1401) based on the generation of a target frame in its own device. In the following text, the occupancy request frame and the occupancy response frame will sometimes be collectively referred to as "occupancy request / response frame". The occupancy request / response frame is received not only by AP 101 in the OBSS but also by STA 112 in the BSS. Thus, the occupancy request / response frame is a frame declaring that the designated channel has been occupied after a predetermined time has elapsed since its transmission. This predetermined time can correspond, for example, to the time used to wait for the transmission / reception in the OBSS of a frame used to occupy the channel in the BSS. That is, the predetermined time can be the time used to wait for AP 101 to instruct STA 102 to transmit an NPCH access or prohibit frame. The predetermined time can be, for example, obtained by adding the predetermined IFS to the length of the radio frame used by AP 101 to send an indication to STA 102. After this predetermined time has elapsed since the transmission or reception of the occupancy request / response frame, AP 111 and STA 112 use the declared occupied channel to perform data communication (F1403 and F1404). Note that if AP 101 receives an occupancy request / response frame, AP 101 does not need to send a response, but can instead send an occupancy response frame, similar to... Figure 5 As shown in the scenario (F1402), an occupancy response frame can be sent to instruct STA 102 to use NPCH access or to disable transmission. Since AP 101 only needs to send this instruction, it can send it in a format other than "response". On the other hand, if an occupancy response frame is received, AP 111 and STA 112 can immediately follow the reception to perform communication via the occupancy channel.

[0103] Reference Figure 15A , Figure 15B , Figure 16A , Figure 16B , Figure 17A , Figure 17B and Figure 18 An example describing the AP's processing procedure in this situation. Note that in Figure 15A , Figure 15B , Figure 16A , Figure 16B , Figure 17A , Figure 17B and Figure 18 In, with Figure 6A , Figure 6B , Figure 7A , Figure 7B , Figure 8A , Figure 8B and Figure 9 References marked with the same reference mark indicate the same processing and their detailed descriptions will be omitted. Figure 15A and Figure 15B The processing shown is Figure 6A and Figure 6B The differences in the processing shown are: the processing when an occupancy request frame is received from a STA in the BSS (step S1501), the processing when an occupancy request / response frame is received from an AP in the OBSS (step S1503), and the processing for channel occupancy (step S1504). Note that there is a formal difference (step S1502) because the AP in the OBSS receives not only occupancy request frames but also occupancy response frames.

[0104] Figure 16A and Figure 16B The process in step S1501 is illustrated. If the AP receives an occupancy request frame from a STA in the BSS requesting to occupy the PCH of the OBSS ("Yes" in step S702), then the AP sends an occupancy response frame to both the STA in the BSS and the AP in the OBSS (step S1601). This occupancy response frame includes the same information as the occupancy request frame described as being sent by AP111 in the example above, except that this frame is not a request for channel occupancy but a declaration of channel occupancy. That is, information indicating the channel to be occupied and information indicating the occupancy period are included in the occupancy response frame. Note that instead of the occupancy response frame, a frame in the format of an occupancy request frame can be sent. Subsequently, if the AP receives a response frame from the AP in the OBSS or a predetermined time has elapsed ("Yes" in step S1602), then the AP recognizes that the channel is occupied and uses these channels to perform reception processing of radio frames from the STA in the BSS. The remaining processing is the same as... Figure 7A and Figure 7B The same as in.

[0105] Figure 17A and Figure 17B The process in step S1503 is illustrated. In this variation, if the AP receives an occupancy request frame from the AP in the OBSS, then the AP never rejects it. Therefore, the procedure is omitted. Figure 8A and Figure 8B The processes shown are steps S801 and S810. The remaining processes are... Figure 8A and Figure 8B The same as in.

[0106] Figure 18The process in step S1504 is illustrated. When transmitting data generated in the device while the PCH is available, the AP sends an occupancy request frame not only to APs in the OBSS but also to STAs in the BSS (step S1801). Note that in step S1801, when transmitting data generated in the device, for example, if the AP receives an occupancy request frame due to the generation of target data from STAs in the BSS, the AP can send an occupancy response frame. Then, when a predetermined time has elapsed since the transmission of the occupancy request frame ("Yes" in step S1802), the AP performs the process of transmitting a radio frame on the declared occupied channel. If the AP receives an occupancy response frame from APs in the OBSS, it can perform the radio frame transmission process even before the predetermined time has elapsed. Note that in this variant, the AP can transmit a radio frame by assuming the channel is occupied regardless of the content of the occupancy response frame. Remaining processing and Figure 9 The same as in.

[0107] Then, refer to Figure 19A , Figure 19B , Figure 19C , Figure 20 and Figure 21 An example describing the processing procedure of the STA. Besides the processing when the AP sends a radio frame requesting channel occupancy (step S1902) and the processing when target data requesting channel occupancy is generated in the STA (step S1903), Figures 19A to 19C The processing shown is Figures 10A to 10C The processing shown is the same. Note that when there is target data to be sent in the AP in the BSS, there is a formal difference because the received frame is a request frame for occupancy instead of an occupancy response frame (step S1901). Figure 20 An example of the process in step S1902 is shown. If the STA receives an occupancy request frame ("Yes" in step S1901) for transmitting a radio frame requesting channel occupancy in the AP, then the STA waits for a predetermined time from the receipt of the occupancy request frame (step S2001). After the predetermined time has elapsed ("Yes" in step S2001), the STA performs radio frame reception processing, similar to... Figure 11 Note that if the STA receives an occupancy response frame from the AP in the OBSS, it can perform radio frame reception processing even before the scheduled time has elapsed, similar to... Figure 11 . Figure 21An example of the process in step S1903 is shown. If target data for transmission requiring channel occupancy is generated, the STA sends an occupancy request frame to the AP in the BSS (step S1301) and waits for an occupancy response frame (step S2101). If the STA does not receive an occupancy response frame ("No" in step S2101), it determines that the channel cannot be occupied and ends the process without sending the target data frame (process returns to...). Figures 19A to 19C The process shown is repeated in a series of steps. On the other hand, if the STA receives an occupancy response frame from the AP in the BSS ("Yes" in step S2101), then it waits to receive an occupancy response frame from the AP in the OBSS or for a predetermined time to elapse (step S2102). Then, when it receives an occupancy response frame from the AP in the OBSS or when the predetermined time has elapsed ("Yes" in step S2102), the STA performs the process of sending the target frame using the channel declared occupied by the AP.

[0108] As described above, for example, when using frames that declare occupancy, after sending an occupancy request frame from the AP, it is not necessary to receive permission from the AP in the OBSS and notify the STA of the permission. Therefore, the time when the AP and STA cannot send / receive data can be reduced, and frequency resources can be used more efficiently for communication.

[0109] Note that the terms "occupancy request frame" and "occupancy response frame" are used to describe the nature of the frames, and the frame names can be changed. The above embodiments have illustrated examples of explicitly distinguishing the roles of the AP and STA, but it is not always necessary to distinguish these devices. That is, a process described as being performed by the AP can be performed by the STA, and vice versa. The above embodiments can be used in any combination, and some processes do not need to be performed without departing from the scope of the invention.

[0110] 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 circuitry (e.g., an ASIC) for implementing one or more functions.

[0111] 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 following claims are made to inform the public of the scope of this invention.

[0112] This application claims priority to Japanese Patent Application No. 2023-185794, filed on October 30, 2023, which is incorporated herein by reference.

Claims

1. An access point device for performing communications conforming to the IEEE 802.11 series of standards, comprising: A communication component is configured to communicate with another communication device belonging to a first network constructed by the access point device using one of a first channel access method and a second channel access method, wherein the first channel access method uses at least a predetermined primary channel in a link, and the second channel access method does not use the primary channel but uses a non-primary channel different from the primary channel among a plurality of channels included in the link. If a radio frame relating to the occupancy of at least one channel including the main channel is received from another access point device that constructs a second network different from the first network, and the at least one channel including the main channel is occupied in the second network, the communication component sends a notification to the other communication device indicating that the second channel access method should be used or that the transmission of radio frames should be prohibited.

2. The access point device according to claim 1, wherein... The first channel access method is a main channel access method for accessing the access point device based on the results of carrier sensing of the main channel, and The second channel access method is a non-primary channel access method for accessing the access point device based on the results of carrier sensing of the non-primary channel.

3. The access point device according to claim 1, wherein... The main channel is a standard-defined main channel based on the IEEE 802.11 standard series, and The non-master channel is defined as a non-master channel based on at least one standard in the IEEE 802.11 standard series.

4. The access point device according to any one of claims 1 to 3, wherein A radio frame relating to the occupancy of at least one channel including the main channel is a radio frame requesting occupancy of at least one channel including the main channel. The access point device further includes a determining component configured to determine, upon receiving a radio frame from the other access point device requesting the occupancy of the at least one channel including the primary channel, whether to permit the occupancy of the at least one channel including the primary channel. In the event that the occupancy of at least one channel, including the main channel, is permitted, the communication component sends a response indicating a permission request to the other access point device and sends a notification to the other communication device indicating that the second channel access method should be used or that the transmission of radio frames should be prohibited.

5. The access point device of claim 4, wherein the notification is included in the response.

6. The access point apparatus of claim 4 or 5, wherein the response includes information indicating a permitted period of occupancy for the at least one channel including the primary channel.

7. The access point device according to any one of claims 4 to 6, wherein, in the absence of permission for occupancy of the at least one channel including the main channel, the communication component sends a response indicating a rejection request to the other access point device and does not send the notification to the other communication device.

8. The access point apparatus of claim 1, wherein the radio frame relating to the occupancy of the at least one channel including the main channel is a radio frame declaring the occupancy of the at least one channel including the main channel, and wherein, if the radio frame is transmitted from the other access point apparatus, the at least one channel including the main channel is occupied in the second network.

9. The access point device according to any one of claims 1 to 8, wherein if all channels available for communication between the access point device and the other communication device are occupied by the other access point device, the communication component sends the notification to the other communication device indicating that the transmission of radio frames is prohibited.

10. The access point apparatus according to any one of claims 1 to 9, wherein the notification includes information indicating one of a period during which the second channel access method should be used and a period during which the transmission of the radio frame is prohibited.

11. The access point apparatus according to any one of claims 1 to 10, wherein when instructing the other communication apparatus to use the second channel access method, the notification includes information for specifying the channel among the non-primary channels to be used for obtaining the right to transmit in the second channel access method.

12. A communication apparatus for performing communications conforming to the IEEE 802.11 series of standards, comprising: A communication component is provided for communicating with a first access point device in a first network using one of a first channel access method and a second channel access method, wherein the first channel access method uses at least one predetermined primary channel in a link, and the second channel access method does not use the primary channel but uses a non-primary channel different from the primary channel among a plurality of channels included in the link. Wherein, if the communication component receives information indicating that the second channel access method should be used in a response sent by the first access point device in response to a radio frame related to the occupancy of at least one channel including the main channel sent by the second access point device in response to a second access point device constructing a second network different from the first network, the communication component uses the second channel access method; or if the communication component receives information indicating that the transmission of radio frames is prohibited in the response, the communication component does not transmit radio frames.

13. The communication apparatus of claim 12, wherein the response includes information indicating one of a period during which the second channel access method should be used and a period during which the transmission of the radio frame is prohibited.

14. An access point device for performing communications conforming to the IEEE 802.11 series of standards, comprising: A communication component, wherein the communication component is used to construct a first network and to communicate with a first other communication device that joins the first network. The communication component transmits radio frames to another access point device constructing a second network, in which communication is performed using either a first channel access method or a second channel access method. The first channel access method uses a predetermined primary channel in a link, while the second channel access method does not use the primary channel but uses a non-primary channel among a plurality of channels included in the link, different from the primary channel. The radio frames are related to the occupancy of at least one channel including the primary channel. The communication component, based on the transmission of the radio frame, performs communication with the first other communication device using at least one channel including the main channel, and The radio frame is a radio frame used to cause the other access point device to send one of an instruction to use the second channel access method and an instruction to prohibit the transmission of radio frames to a second other communication device that has joined the second network, in the event that the other access point device receives the radio frame and the at least one channel including the main channel is occupied in the first network.

15. The access point device according to claim 14, wherein... A radio frame relating to the occupancy of at least one channel including the primary channel is a radio frame requesting occupancy of at least one channel including the primary channel, and Upon receiving a response from the other access point device indicating permission to occupy at least one channel including the main channel, the communication component uses the at least one channel including the main channel to perform communication with the first other communication device.

16. The access point apparatus of claim 15, wherein the response includes information indicating a permitted period of occupancy for the at least one channel including the primary channel.

17. The access point device according to claim 15 or 16, wherein, Upon receiving a response from the other access point device indicating that occupancy of at least one channel, including the main channel, is permitted, the communication component sends information to the first other communication device indicating that occupancy of at least one channel, including the main channel, is permitted.

18. The access point device according to any one of claims 15 to 17, wherein upon receiving a response from the other access point device indicating that occupancy of the at least one channel including the main channel is not permitted, the communication component does not perform communication with the first other communication device regarding the use of the at least one channel including the main channel.

19. The access point device according to any one of claims 15 to 17, wherein, upon receiving a response from the other access point device indicating that occupancy of the at least one channel including the main channel is not permitted, the communication component performs contention-based channel access with the first other communication device on the at least one channel including the main channel.

20. The access point device according to claim 14, wherein... A radio frame relating to the occupancy of at least one channel including the primary channel is a radio frame declaring the occupancy of at least one channel including the primary channel, and Even if no response is received from the other access point device, the communication component communicates with the first other communication device using at least one channel, including the main channel, after a predetermined time.

21. The access point apparatus of claim 20, wherein a radio frame declaring occupancy of the at least one channel including the primary channel is also transmitted to the first other communication apparatus.

22. The access point apparatus according to claim 20 or 21, wherein the predetermined time is determined based on a predetermined inter-frame interval (IFS) during which the other access point apparatus sends one of an instruction to the second other communication apparatus to use the second channel access method and an instruction to prohibit the transmission of radio frames.

23. The access point device according to any one of claims 14 to 22, wherein, upon receiving a request from the other access point device, the communication component sends a radio frame to the first other communication device relating to the occupancy of the at least one channel including the main channel.

24. A communication apparatus for performing communications conforming to the IEEE 802.11 series of standards, comprising: A communication component, wherein the communication component is configured to join a first network constructed by a first access point device and to communicate with the first access point device. The communication component Send a request to the first access point device to occupy at least one channel in a link, including a predetermined main channel, and In the case where the at least one channel including the main channel is occupied by sending a radio frame relating to the occupancy of the at least one channel including the main channel from the first access point device to the second access point device constructing the second network, communication is performed in the second network using one of a first channel access method and a second channel access method, where the first channel access method uses at least the main channel, and the second channel access method does not use the main channel but uses a non-main channel among the multiple channels included in the link that is different from the main channel, communication is performed with the first access point device using the at least one channel including the main channel.

25. The communication apparatus of claim 24, wherein upon receiving a notification from the first access point device indicating that the first access point device is permitted to occupy the at least one channel including the main channel, the communication component performs communication with the first access point device using the at least one channel including the main channel.

26. The communication device according to claim 24, wherein... Radio frames sent from the first access point device to the second access point device relating to the occupancy of at least one channel including the main channel are radio frames declaring the occupancy of at least one channel including the main channel, and The communication component communicates with the first access point device using at least one channel, including the main channel, after a predetermined time has elapsed since the transmission of the radio frame.

27. The communication apparatus of claim 26, wherein the predetermined time is determined based on a predetermined inter-frame interval (IFS) during which the second access point device sends one of an instruction to another communication device joining the second network to use the second channel access method and an instruction to prohibit the transmission of radio frames.

28. A communication method performed by an access point device, the access point device being configured to perform communication conforming to the IEEE 802.11 standard series with another communication device belonging to a first network constructed by the access point device by using one of a first channel access method and a second channel access method, wherein the first channel access method uses at least one predetermined primary channel in a link, and the second channel access method does not use the primary channel but uses a non-primary channel different from the primary channel among a plurality of channels included in the link, the method comprising: If a radio frame relating to the occupancy of at least one channel including the main channel is received from another access point device that constructs a second network different from the first network, and the at least one channel including the main channel is occupied in the second network, a notification is sent to the other communication device indicating that the second channel access method should be used or that the transmission of radio frames should be prohibited.

29. A communication method performed by a communication device, the communication device being configured to perform communication conforming to the IEEE 802.11 standard series with a first access point device in a first network using one of a first channel access method and a second channel access method, wherein the first channel access method uses at least one predetermined primary channel in a link, and the second channel access method does not use the primary channel but uses a non-primary channel different from the primary channel among a plurality of channels included in the link, the method comprising: If the first access point device receives information indicating that the second channel access method should be used in a response to a radio frame sent by a second access point device that is constructing a second network different from the first network, relating to the occupancy of at least one channel including the main channel, the second channel access method is used; or if the first access point device receives information indicating that the transmission of radio frames is prohibited in the response, no radio frame is transmitted.

30. A communication method performed by an access point device for constructing a first network and performing communication conforming to the IEEE 802.11 series of standards with a first other communication device joined to the first network, the method comprising: A radio frame is sent to another access point device constructing a second network, in which communication is performed using one of a first channel access method and a second channel access method. The first channel access method uses a predetermined primary channel in a link, and the second channel access method does not use the primary channel but uses a non-primary channel among a plurality of channels included in the link that is different from the primary channel. The radio frame relates to the occupancy of at least one channel including the primary channel. Based on the transmission of the radio frame, communication is performed with the first other communication device using at least one channel including the main channel. The radio frame is a radio frame used to cause the other access point device to send one of an instruction to use the second channel access method and an instruction to prohibit the transmission of radio frames to a second other communication device that has joined the second network, in the event that the other access point device receives the radio frame and the at least one channel including the main channel is occupied in the first network.

31. A communication method performed by a communication device, the communication device being configured to join a first network constructed by a first access point device and perform communication with the first access point device conforming to the IEEE 802.11 standard series, the method comprising: Send a request to the first access point device to occupy at least one channel in a link, including a predetermined main channel; as well as In the case where the at least one channel including the main channel is occupied by sending a radio frame relating to the occupancy of the at least one channel including the main channel from the first access point device to the second access point device constructing the second network, communication is performed in the second network using one of a first channel access method and a second channel access method, where the first channel access method uses at least the main channel, and the second channel access method does not use the main channel but uses a non-main channel among the multiple channels included in the link that is different from the main channel, communication is performed with the first access point device using the at least one channel including the main channel.

32. A program for causing a computer to act as a component of an access point device as described in any one of claims 1 to 11 or 14 to 23.

33. A program for causing a computer to act as a component of a communication device as described in any one of claims 12, 13, or 24 to 27.

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