Station device, method for controlling the station device, and program

Abstract

One of the objectives is to provide a mechanism for communication control suitable for communication systems that use composite channels, which are formed by combining multiple channels. [Solution] The STA transmits a frame to the AP that includes a first NPCA Switching Delay and a first NPCA Switch Back Delay related to NPCA (Non-primary channel access) operation, a second NPCA Switching Delay different from the first NPCA Switching Delay, and a second NPCA Switch Back Delay different from the first NPCA Switch Back Delay.

Description

[Technical Field]

[0001] The present invention relates to a station apparatus that performs wireless communication, a control method for a communication apparatus, and a program. [Background Art]

[0002] As a communication standard for wireless LAN (Wireless Local Area Network), the IEEE (Institute of Electrical and Electronics Engineers) 802.11 standard is known. In the IEEE 802.11be standard and its successor standard, the IEEE 802.11bn standard, technologies for reducing communication latency and improving channel utilization efficiency are under study.

[0003] Patent Document 1 describes a technology in which, when a communication apparatus cannot use a primary channel used for acquiring transmission rights, the communication apparatus performs communication using another channel. [Prior Art Literature] [Patent Literature]

[0004] [Patent Document 1] US Patent Application Publication No. 2020 / 413465 Specification [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] An object of the present invention is to provide a communication control technology suitable for a communication system using a composite channel formed by bundling a plurality of channels. [Means for Solving the Problem]

[0006] To achieve the above objective, a station device as one aspect of the present invention is characterized by having a transmission control means for transmitting a frame to an access point device that includes a first NPCA Switching Delay and a first NPCA Switch Back Delay related to an NPCA (Non-primary channel access) operation that switches to another channel inside the BSS operating channel of an access point providing a BSS (Basic Service Set) to which the station device is connected, which is a channel different from the channel to which the station device is operating, a second NPCA Switching Delay different from the first NPCA Switching Delay and a second NPCA Switch Back Delay different from the first NPCA Switch Back Delay. [Effects of the Invention]

[0007] According to one aspect of the present invention, it becomes possible to perform communication control suitable for a communication system that uses a composite channel formed by bundling multiple channels. [Brief explanation of the drawing]

[0008] [Figure 1] This is a diagram showing an example of the configuration of a wireless communication system. [Figure 2] This is a schematic diagram showing an example of a time chart for when a communication device transmits data. [Figure 3] This figure shows an example of the hardware configuration of a communication device. [Figure 4] This diagram schematically shows the connection process flow between AP and STA. [Figure 5] This figure shows an example of the configuration of elements that communicate between devices. [Figure 6] This figure shows an example of the configuration of elements that communicate between devices. [Figure 7] This is a schematic diagram illustrating the NPCA mode in this embodiment. [Figure 8] This is a schematic diagram illustrating other NPCA modes as variations. [Figure 9] This flowchart illustrates an example of control in AP / STA. [Figure 10] This is a flowchart illustrating an example of control in STA. [Figure 11] This is a flowchart illustrating an example of control in STA. [Figure 12] This flowchart illustrates a modified control method in STA. [Figure 13] This figure shows an example of the channel access function of a communication device using EDCA. [Figure 14] This figure shows an example of a Probe Response frame. [Modes for carrying out the invention]

[0009] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the invention as defined in the claims. While the embodiments describe multiple features, not all of these features are essential to the invention, and the features may be combined in any way. Furthermore, in the attached drawings, identical or similar configurations are given the same reference numerals, and redundant descriptions are omitted.

[0010] <First Embodiment> Figure 1 shows an example configuration of a wireless communication system according to this embodiment. The wireless communication system includes, for example, an access point (AP101) and stations (STA102 and STA103). In the following, the access point may be referred to as AP STA, and the stations as non-AP STA. AP101 and STA102-STA103 are communication devices capable of performing wireless communication compliant with the IEEE 802.11 standard series. In this embodiment, when it is not necessary to distinguish between AP101 and STA102-STA103, they may be collectively referred to as communication devices. IEEE stands for Institute of Electrical and Electronics Engineers. Figure 1 shows a configuration in which STA102-STA103 participate in a network 111 established by AP101. Network 111 may also be called a Basic Service Set (BSS). In Figure 1, a network 131, composed of AP121 and with STA122 participating, exists near network 111, which is composed of AP101 and with STA102-STA103 participating. AP121 and STA122 are communication devices capable of performing wireless communication compliant with the IEEE 802.11 standard series, similar to AP101 and STA102-STA103. For AP101 and STA102-STA103, network 111 is the BSS to which their devices are connected, and hereafter, this BSS will be referred to as the self-BSS or simply BSS. On the other hand, for AP101 and STA102-STA103, network 131 is a network that can interfere with the self-BSS and may be called an Overlapping BSS (OBSS). In Figure 1, networks 111 and 131 are shown with two STAs and one STA participating, respectively, but are not limited to this configuration. In other words, one or more STAs may participate in network 111, and multiple STAs may participate in network 131. Also, one STA may participate in multiple networks.

[0011] In this embodiment, AP101 and STA102~STA103 are configured to execute a communication method compliant with the IEEE 802.11bn standard or its successor standard. The IEEE 802.11bn standard is the successor standard to the IEEE 802.11be standard. The IEEE 802.11bn standard is expected to implement functions that realize highly reliable communication, low latency communication, and improved throughput when communication traffic is congested, among other main features. The wireless frame used in a communication method compliant with this standard may be called a UHR (Ultra High Reliability) PPDU. PPDU is an abbreviation for Physical Layer Protocol Data Unit. Note that the names UHR and IEEE 802.11bn may be changed to different names when the standard is finalized. Also note that this specification and the claims attached herein are applicable to communication devices using all successor standards that are successors to the IEEE 802.11be standard. Furthermore, the communication device may support at least one of the legacy standards that predate the IEEE 802.11bn standard. Legacy standards include, for example, the IEEE 802.11a / b / g / n / ac / ax / be standards. The communication device may also support other communication standards such as Bluetooth®, NFC, UWB, ZigBee, and MBOA. UWB stands for Ultra Wide Band, and MBOA stands for Multi Band OFDM Alliance. NFC stands for Near Field Communication. UWB includes wireless USB, wireless 1394, and WiNET. The communication device may also support communication standards such as wired LAN. AP101 is, for example, a wireless LAN router or a personal computer (PC), but is not limited to these. AP101 may be an information processing device such as a wireless chip capable of performing wireless communication compliant with the IEEE 802.11bn standard. STA102~STA103 includes, but is not limited to, cameras, tablets, smartphones, PCs, mobile phones, video cameras, and headsets.STA102~STA103 may be information processing devices such as wireless chips capable of performing wireless communication compliant with standards such as IEEE802.11bn.

[0012] Communication devices can transmit and receive wireless signals using frequency bands such as the 2.4GHz, 3.6GHz, 5GHz, and 6GHz bands, as well as millimeter-wave bands such as the 45GHz and 60GHz bands. The frequency bands used by communication devices are not limited to these and may include, for example, the Sub1GHz band. Furthermore, communication devices can communicate using bandwidths of 20MHz, 40MHz, 80MHz, 160MHz, 320MHz, 540MHz, 640MHz, 1080MHz, and 2160MHz. The bandwidths used by communication devices are not limited to these and may include, for example, bandwidths of 240MHz or 4MHz. In addition, the IEEE 802.11 standard series specifies frequency channels using a 20MHz bandwidth as basic channels in frequency bands such as the 2.4GHz, 5GHz, and 6GHz bands. Furthermore, this standard defines multiple usable channels in each of the 2.4GHz, 5GHz, and 6GHz frequency bands. In this standard, communication devices can use one channel in combination with other adjacent channels. This use of one channel in combination with other adjacent channels may be called channel bonding. The size of a channel bundle formed by one or two or more adjacent channels may be called the BSS bandwidth or STA operating channel width. BSS bandwidth refers to the maximum bandwidth that an access point allows for PPDU transmission in the BSS provided by the access point. BSS bandwidth may also be called the BSS operating channel. STA operating channel width refers to the maximum bandwidth that an STA participating in the BSS supports for PPDU transmission and reception. When an STA connects to an AP, it determines the STA operating channel width based on the AP's BSS bandwidth and the bandwidth it supports. The STA then forms a link with the AP using the determined STA operating channel width as the maximum bandwidth used for PPDU transmission and reception, and communicates with the AP. If the STA operating channel width is 40Hz, formed by two channels with a bandwidth of 20MHz, then a bandwidth of 40MHz may be used for communication.The IEEE 802.11be standard specifies 320 MHz as the maximum bandwidth available on a single link. In this case, a BSS (Band Single Slash) with a 320 MHz BSS bandwidth can be formed by bundling 16 channels. An STA connected to this 320 MHz BSS operates with one of the following STA operating channel widths, based on its supported bandwidth: 320 MHz, 160 MHz, 80 MHz, 40 MHz, or 20 MHz. Signals transmitted within this bandwidth may be continuous or partially discontinuous on the frequency axis. AP101 and STA102-STA103 may be AP MLDs (Multi-Link Devices) and STA MLDs, respectively, that support Multi-Link, enabling simultaneous establishment and communication of multiple links.

[0013] When transmitting a signal using a link established with another communication device, the communication device determines whether transmission is possible by performing carrier sense. Carrier sense is an operation in which a communication device determines whether there is a signal on a channel that the device intends to use for transmission. For example, the communication device measures the intensity of a signal received on the channel (received signal strength), and determines that a signal exists when the received signal strength exceeds a predetermined threshold (physical carrier sense). Received signal strength may also be referred to as Received Signal Strength Indicator (RSSI). Further, the communication device can determine the presence or absence of a signal based on information such as a Duration field included in a signal received on the channel (virtual carrier sense). For example, the communication device stores, in itself, the period indicated by the Duration field included in the received signal as a Network Allocation Vector (NAV). The communication device treats the stored NAV as a period during which transmission of wireless frames by the device itself is prohibited. In the present embodiment, the operation in which the communication device sets a period during which the device itself does not perform transmission based on information such as the Duration field of a received signal is referred to as setting an NAV. That is, until the NAV set for the channel expires, the communication device determines that a signal is present on the channel. As described above, the communication device determines whether a signal is present on the channel based on the results of executing physical carrier sense and virtual carrier sense. When the communication device determines that a signal is present on the channel, it determines that signal transmission is not possible. The channel state in this case is called a busy state. On the other hand, a state where no signal is detected on the channel in carrier sense and no NAV is set is called an idle state. The communication device determines that a signal can be transmitted when the channel is in an idle state.

[0014] When a communication device communicates using, for example, a 160MHz bandwidth, it uses only a first channel with a 20MHz bandwidth to determine whether transmission is possible. This first channel is the channel on which the Beacon is transmitted in the BSS, and is called the BSS Primary Channel (BSS PCH). For example, the IEEE 802.11 standard series states that a communication device can start transmitting a signal if it determines that transmission is possible as a result of performing carrier sensing on the BSS PCH over a predetermined period. The predetermined period is determined by the Interframe Space (IFS) defined for each access category that classifies the type of communication traffic, and a random number (backoff counter) randomly determined from a predetermined range. In other words, if the communication device determines that the BSS PCH is idle over this predetermined period, it acquires the right to transmit data via the STA operating channel. At this time, if a second channel other than the BSS PCH was idle during the PIFS period immediately before the start of transmission, the communication device may perform transmission by channel bonding using that idle channel and the PCH. PIFS is an abbreviation for Priority IFS. Furthermore, if the communication device determines, as a result of carrier sensing on the PCH, that it cannot transmit a signal, it will postpone transmission, even if the other channels constituting the STA operating channel width are idle, by not transmitting the signal on the other channels alone. Note that each of the second channels other than the BSS PCH included in the STA operating channel width may also be called a Non-Primary Channel (NPCH) or Secondary Channel (SCH).

[0015] In a communication apparatus, when a signal is being received on a certain channel, if a signal is transmitted on another channel arranged at a frequency close to that channel (for example, an adjacent channel), the received signal may not be properly received. For example, assume that a communication apparatus can simultaneously perform transmission processing and reception processing using different channels. When the communication apparatus is performing reception using a certain channel and performs transmission on an adjacent channel, the power of the transmission signal leaks into the channel of the reception signal, thereby causing interference to the reception signal. Generally, the power resulting from such leakage of a transmission signal is far larger than the reception power of the reception signal, so it is expected that proper reception of a signal cannot be performed. To avoid such a situation, the idea of the IEEE 802.11 standard series is to prevent another communication apparatus from transmitting a signal using a channel adjacent to a PCH to a communication apparatus while the communication apparatus is transmitting a signal. In other words, it can be said that a BSS PCH is provided as a channel that is commonly used among communication apparatuses to determine whether transmission is permitted. Here, in conventional standards, it is规定 that while one communication apparatus is performing transmission using a BSS PCH, the other communication apparatus does not perform transmission even if a channel adjacent to the BSS PCH is in an idle state.

[0016] However, the fact that other idle channels (NPCHs) are not used based on the BSS PCH being busy can hinder the efficient use of the overall frequency resources of the BSS. Figure 2(A) shows an example of a time chart when STA102 or STA103 transmits data to AP101. In Figure 2(A), STA102 or STA103 performs carrier sensing on the PCH, confirms that it is idle, and then transmits data using the 20MHz bandwidth PCH. In this case, for example, even if the seven NPCHs other than the PCH are idle, other communication devices are not allowed to communicate using the NPCHs. Figure 2(B) shows another example of a time chart when STA102 or STA103 transmits data to AP101. In Figure 2(B), while STA102 or STA103 is performing carrier sensing on the PCH, the BSS PCH is being used by another network (e.g., network 131) located in the geographical vicinity of the STAs. In this case, the carrier sense by STA102 or STA103 determines that the PCH is busy. Therefore, even if the seven NPCHs other than the PCH are idle, STA102 or STA103 is not allowed to communicate with AP101 using the NPCHs. However, since AP101 is not transmitting at this time, if STA102 or STA103 transmits to AP101 using the NPCHs, AP101 is expected to be able to properly receive the signal transmitted by STA102 or STA103. Thus, if, for example, a PCH with a bandwidth of 20 MHz is used by another network, and the remaining 140 MHz of idle NPCHs are not utilized, then the frequency resources cannot be used efficiently.

[0017] In contrast, the IEEE 802.11bn standard is considering adopting a function that allows communication between communication devices using other NPCHs that make up the BSS band, instead of using the BSS PCH when the BSS PCH is being used by other communication devices in the OBSS band. In this embodiment, this communication method, which transmits using an NPCH without using the BSS PCH, is called Non-Primary Channel Access (NPCA). Attempting to communicate using this communication method is also called an NPCA operation. This communication method may also be called by other names such as NPCH Channel Access or SCA (Secondary Channel Access). As an example, a communication device sets a predetermined channel to acquire the right to transmit using NPCA when the BSS PCH is busy. This predetermined channel may be called the NPCA Primary Channel (NPCA PCH). The NPCA PCH is one of the channels among the NPCHs that make up the BSS band. Note that the name NPCA PCH is just an example, and other names may be used. For example, a channel with a high priority for determining whether transmission is possible among multiple secondary channels may be called a Secondary PCH (SPCH) or a Primary Secondary Channel (PSCH). Also, an NPCA PCH may be called by a different name, as long as it has the same meaning as a channel used to determine whether transmission using an NPCH is possible. If the communication device determines that a PCH is being used by another communication device, it switches the channel on which carrier sensing should be performed to the NPCA PCH and determines whether transmission is possible on that NPCA PCH. That is, the communication device performs the carrier sensing described above on the NPCA PCH and, based on the confirmation that the NPCA PCH is idle, determines that it can perform communication using an NPCH. Then, if the communication device determines that transmission is possible on the NPCA PCH, it performs transmission using one or more NPCHs, including the NPCA PCH.

[0018] In NPCA, the transmitting communication device attempts channel access using the NPCA PCH and transmits a signal to the receiving communication device using one or more NPCHs, including the NPCA PCH. Meanwhile, the receiving communication device waits for the signal transmitted from the receiving communication device using one or more NPCHs, including the NPCA PCH, and performs receiving processing as needed. To perform NPCA, AP101 and STA102~STA103 share information about NPCA (such as information identifying the NPCA PCH) with the receiving communication device in advance. To notify the information identifying the NPCA PCH, for example, AP101 may transmit an element in a frame such as a Beacon frame that includes information indicating the BSS Operating Class and information specifying the NPCA PCH Channel. The Operating Class is an identifier that uniquely identifies the frequency band defined by the country or region in which AP101 is used. The NPCA PCH Channel is included in the UHR Capabilities element described later. This information states that the Channel is an identifier that uniquely identifies each channel included in the frequency band identified by the Operating Class. Note that the method of indicating NPCA channels is just one example and is not limited to this. AP101 may indicate the position of an NPCA PCH by storing in its element the relative position of the NPCA PCH on the frequency axis with respect to the PCH. For example, suppose the communication device 100 uses a 160MHz wide BSS band in the 6GHz band and sets channel 1 in that band as a PCH (20MHz bandwidth). Also, suppose that each NPCH (20MHz bandwidth) is channel 5, 9, 13, 17, 21, 25, and 29. In this case, if channel 21 is set as the NPCA PCH, "20" may be set as the information that identifies the NPCA PCH. That is, 20, which is the relative distance on the frequency axis from channel 1 (PCH) to channel 21 (NPCA PCH), may be set as the information that identifies the NPCA PCH.

[0019] NPCA considers two methods for initiating communication between non-AP STAs and non-AP STAs when a non-AP STA transmits a wireless frame: a first method in which the AP STA initiates communication with the non-AP STA, and a second method in which the non-AP STA spontaneously accesses the channel using EDCA. EDCA stands for Enhanced Distributed Channel Access. The first method uses a trigger frame to initiate communication, whereas the second method does not. For this reason, the second method can also be called Untriggered Uplink (UL) Transmission (UUT). The operating mode in which both AP STAs and non-AP STAs can perform UUT is called UUT mode. For a non-AP STA to operate in UUT mode, the AP STA to which the non-AP STA is connected must have UUT mode enabled (i.e., be permitted to use UUT mode). When UUT mode is enabled, non-AP STAs compete for channel access with other non-AP STAs using a backoff counter calculated based on the contention window (CW). AP STA is expected to set different CW values ​​for, for example, accessing a PCH and accessing an NPCA PCH in an NPCA. AP101 transmits information for determining these CW values, along with information identifying the NPCA PCH, to the STA.

[0020] As mentioned above, AP101 selects an NPCA PCH, notifies the STAs of the selected NPCA PCH information via a frame such as a Beacon, and the STAs switch to the NPCA PCH when performing NPCA operations. Here, depending on the operating channel width of the STA, it may be necessary to transition to an NPCA PCH located outside of its own operating channel width. The time required for this switch may involve switching the frequency band being captured, and the time required for channel switching tends to be longer. On the other hand, it is assumed that switching to an NPCA PCH located inside the operating channel width can switch the frequency range of interest by switching the control of internal processing without controlling antennas or other devices. In other words, it is assumed that switching to an NPCA PCH located inside the STA's operating channel width can be done in a shorter time compared to the aforementioned switch to the outside. Furthermore, for AP101 and STA to transition to NPCA and communicate effectively, it is desirable that they both know the timing when the transition to NPCA is complete and the other party is ready to accept communication.

[0021] In this embodiment, in light of these circumstances, a method is provided for notifying multiple switching delays in order to appropriately notify the AP of the time required to switch from the STA to the NPCA PCH.

[0022] <Hardware configuration of communication equipment> Figure 3 shows an example of the hardware configuration of the communication devices (AP101 and STA102~STA103) of this embodiment. As an example of its hardware configuration, the communication device includes, for example, a storage unit 301, a control unit 302, a function unit 303, an input unit 304, an output unit 305, a communication unit 306, and an antenna 307. Note that these are just examples, and the communication device may have further configurations not shown in Figure 3, or some or all of the configurations shown in Figure 3 may be replaced by other configurations having similar functions.

[0023] The storage unit 301 is configured to include one or more memories such as ROM and RAM. The storage unit 301 stores various information such as computer programs for performing the various operations described later, and communication parameters for wireless communication. ROM stands for Read Only Memory, and RAM stands for Random Access Memory. In addition to memories such as ROM and RAM, the storage unit 301 may also be configured to include storage media such as flexible disks, hard disks, optical disks, magneto-optical disks, CD-ROMs, CD-Rs, magnetic tapes, non-volatile memory cards, and DVDs. Furthermore, the storage unit 301 may be configured to include multiple storage media such as memories.

[0024] The control unit 302 is configured to include one or more processors, such as a CPU and an MPU. (CPU stands for Central Processing Unit, and MPU stands for Micro Processing Unit.) The control unit 302 controls the entire communication device by executing computer programs stored in the memory unit 301. Alternatively, the control unit 302 may control the entire device through cooperation between the computer programs stored in the memory unit 301 and the operating system. Furthermore, the control unit 302 generates data and signals (wireless frames) to be transmitted in communication with other communication devices. The control unit 302 may also comprise multiple processors, such as a multi-core processor, and control the entire communication device using these multiple processors.

[0025] Furthermore, the control unit 302 controls the functional unit 303 to perform predetermined processes such as wireless communication, imaging, printing, and projection. The functional unit 303 is configured to include hardware for the communication device to perform predetermined processes. If the communication device is a printer, the functional unit 303 is a printing device and performs printing on a sheet such as paper based on print data or image data acquired via the communication unit 306, for example. The printing method may be an inkjet method, an electrophotographic method, or any other method. If the communication device is a scanner, the functional unit 303 is a reading device and outputs the image data generated by scanning to the outside, for example via the communication unit 306. If the communication device is a camera, the functional unit 303 is configured to include an image sensor and a lens and outputs the image data captured by the camera to the outside, for example via the communication unit 306. Also, if the communication device is a projector or smart glasses, for example, the functional unit 303 is a projection unit and performs projection processing of image data or video data obtained from the outside via wireless communication. In the case of smart glasses, the projection surface is the end user's retina, etc. The data processed by the functional unit 303 may be data stored in the storage unit 301, or data communicated with other APs or STAs via the communication unit 306, which will be described later. Furthermore, communication devices such as AP101 can also provide network storage functions such as NAS (Network Attached Storage). These functions are provided to other communication devices as web services such as network storage services. For example, communication devices such as STAs connect to the network storage service provided by AP101 using protocols such as SMB, FTP, or WebDAV. Then, communication devices such as STAs upload files to the storage service or download files from the storage. This upload and download data communication is also achieved by communicating UHR PPDU between devices.

[0026] The input unit 304 includes, for example, a touch panel, hard keys, buttons, etc., and accepts various operations from the user. The output unit 305 includes, for example, a display, a speaker, etc., and provides various outputs to the user. Here, the output from the output unit 305 can be a screen display output on the display or an audio output from the speaker. The output unit 305 may also include a vibrator and output information by vibration output. Note that both the input unit 304 and the output unit 305 may be implemented in a single module, such as a touch panel display. The input unit 304 and the output unit 305 may be built into the communication device or implemented by an external input / output device. In this case, the communication device has an input / output interface for connecting to the input / output device.

[0027] The communication unit 306 performs control for wireless communication compliant with the IEEE 802.11bn standard. In addition to the IEEE 802.11bn standard, the communication unit 306 can also control wireless communication compliant with other IEEE 802.11 standard series, such as legacy standards and successor standards, as well as wired communication such as wired LAN. The communication unit 306 controls the antenna 307 to send and receive signals for wireless communication generated by the control unit 302. For example, a communication device communicates data such as image data, document data, and video data with a partner device via the communication unit 306. If the communication device supports standards such as NFC and Bluetooth in addition to the IEEE 802.11bn standard, the communication unit 306 may also perform control of wireless communication compliant with these communication standards. Furthermore, if the communication device is capable of performing wireless communication compliant with multiple communication standards, separate communication units and antennas corresponding to those communication standards may be provided.

[0028] Antenna 307 is, for example, an antenna capable of detecting and radiating radio waves in the 2.4GHz band, 5GHz band, and 6GHz band, respectively. Antenna 307 may also be configured to enable communication in the same frequency band. In this case, antenna 307 may be, for example, a multiband antenna capable of communication in multiple frequency bands. Figure 3 shows an example where the communication device has two antennas, but one antenna may be used, or three or more antennas may be used. If the communication device has multiple antennas, it may have a communication unit 306 corresponding to each antenna. Antenna 307 may be provided separately from the communication unit 306, or it may be configured as a single module together with the communication unit 306. Furthermore, the communication device may be configured to perform carrier sensing of multiple NPCA PCHs in parallel to achieve multilink. In that case, the communication device may have the number of communication units 306 and antennas 307 necessary to perform the carrier sensing of those multiple NPCA PCHs in parallel.

[0029] Next, the functions provided by the communication device will be described. The communication device provides functions such as wireless LAN control, frame generation, frame analysis, UI control, memory control, and NPCA control. Note that these functional configurations are examples, and other functions may be added, or the shown functions may be modified. One functional block may be divided into multiple blocks, or multiple functional blocks may be combined into one. In addition, some functions may be omitted, or functions not shown may be added. In this embodiment, it is assumed that at least some of each of the listed functions are realized by the control unit 302 executing a program stored in the memory unit 301. However, at least some or all of the functions shown in Figure 4 may be realized using dedicated hardware.

[0030] As a function of wireless LAN control, the communication device provides control processing for wireless LAN communication. The communication device controls the communication unit 306 and antenna 307 in order to send and receive wireless signals with other communication devices capable of wireless LAN communication. The wireless LAN control function works in cooperation with the frame generation function and frame analysis function to provide a function that performs wireless frame communication control in accordance with the IEEE 802.11 series standard.

[0031] The frame generation function generates wireless frames such as control frames, management frames, and data frames. Each wireless frame includes a MAC frame. MAC stands for Medium Access Control. A MAC frame is also called a MAC Protocol Data Unit (MPDU) or Aggregate MAC Protocol Data Unit (A-MPDU). A wireless frame consists of a preamble field and a data field. The data field stores MAC frames such as management frames, control frames, and data frames. Wireless control can be performed using each MAC frame generated by the frame generation function. Here, the content of the wireless control may be constrained by the operation settings stored in the storage unit 301 managed by the memory control function. The frame generation function can also accept settings from the user via the UI control function. The wireless frames generated by the frame generation function are supplied to the wireless LAN control function and can be transmitted externally using the communication unit 306 and antenna 307 under the control of the wireless LAN control function. The frame analysis function analyzes the wireless frames received via the communication unit 306 and antenna 307 under the control of the wireless LAN control function. The frame analysis function can determine the analysis method when analyzing wireless frames based on settings stored in the memory unit 301 by the memory control function.

[0032] The UI control function provides the ability to control the input unit 304 to accept input to a user interface (UI), such as a touch panel or buttons, for receiving user operations on the communication device (not shown). The UI control function can also control the output unit 305 to perform operations to present information to the user, such as displaying images or outputting audio. The UI control function can also control the input unit 304 and the output unit 305 to display a graphical user interface (GUI) on the display and accept operations on that GUI. The memory control function controls the memory unit 301 to perform various information storage operations, such as saving, searching, and extracting programs and data on which the communication device operates. The NPCA control function performs control processing for the communication device to perform channel access using NPCA.

[0033] Using Figure 13, an example of the channel access function in AP101 and STA102-STA103 will be explained. The channel access function includes a data categorization unit 1301, a queue 1302, and a channel access control unit 1305. The channel access control unit 1305 also includes a CSMA / CA execution unit 1303 and a backoff / collision control unit 1304.

[0034] The data categorization unit 1301 classifies data received from the upper layer into traffic categories compliant with the EDCA mechanism defined in the IEEE 802.11e standard. The EDCA mechanism prioritizes data transmission by class, so that certain types of traffic are given priority. The data categorization unit 1301 classifies the data into one of the four access categories (ACs) defined in the EDCA mechanism. Typically, the four ACs are "AC_VO" for voice, "AC_VI" for video, "AC_BE" for best-effort, and "AC_BK" for background data. The data categorization unit 1301 stores the data (MAC frame) classified into one of the ACs in the queue 1302 corresponding to that AC. The queue 1302, also called a traffic buffer, is provided for each AC.

[0035] The channel access control unit 1305 performs channel access control based on CSMA / CA for data held in the queue corresponding to each AC in the CSMA / CA execution unit 1303. CSMA / CA stands for Carrier Sense Multiple Access with Collision Avoidance. When the CSMA / CA execution unit 1303 detects that data has been stored in the queue corresponding to each AC, it reads the EDCA parameters associated with that queue (AC) stored in the backoff / collision control unit 1304. Then, the CSMA / CA execution unit 1303 determines the transmit waiting time, consisting of AIFS and a backoff counter, based on the read EDCA parameters. Hereafter, the transmit waiting time, including AIFS and the backoff counter, will also be simply referred to as the backoff parameters. The EDCA parameters can be set so that the transmission of radio signals is relatively prioritized in the order of VO, VI, BE, BK. Each EDCA parameter includes CWmin, CWmax, AIFS, and TXOPLimit. CWmin is the minimum CW time (waiting time for transmission), and CWmax is the maximum CW time. Shorter CWmin and CWmax values ​​make it easier to obtain transmission opportunities. AIFS is the transmission interval for radio signals. Smaller AIFS values ​​make it easier to obtain transmission opportunities. TXOPLimit is the upper limit of TXOP (channel occupancy time). A larger TXOPLimit allows for more data to be transmitted during a single transmission opportunity.

[0036] The backoff / collision control unit 1304 monitors the channel status and notifies the CSMA / CA execution unit 1303 of the channel status information obtained through monitoring. The CSMA / CA execution unit 1303 then decrements the set backoff parameter while the notified channel status is idle and waits without transmitting data until the waiting time becomes zero. The CSMA / CA execution unit 1303 stops the decrementing of the backoff parameter while the notified channel status is busy. The CSMA / CA execution unit 1303 then determines that it has acquired an opportunity to transmit when the waiting time becomes zero. The CSMA / CA execution unit 1303 retrieves data (MAC frame) from the queue and, in cooperation with the backoff / collision control unit 1304, the communication unit 306, and the antenna 307, transmits the UHR PPDU containing the MAC frame to other communication devices. If the communication device obtains a transmission opportunity on the PCH, it transmits a UHR PPDU on one or more channels including the PCH, and if it obtains a transmission opportunity on the NPCA PCH, it transmits a UHR PPDU on one or more channels including the NPCA PCH.

[0037] The backoff / collision control unit 1304 also performs mediation in the event of an internal conflict when CSMA / CA execution units 1303 corresponding to each AC acquire a transmission opportunity. That is, if CSMA / CA execution units 1303 corresponding to different ACs acquire a transmission opportunity simultaneously and request to transmit data, the backoff / collision control unit 1304 controls the system so that data stored in the higher priority queue is transmitted preferentially. For example, if a CSMA / CA execution unit 1303 corresponding to a VO queue and a CSMA / CA execution unit 1303 corresponding to a BK queue acquire a transmission opportunity simultaneously, the backoff / collision control unit 1304 controls the system so that data stored in the VO queue is transmitted preferentially. At this time, the backoff / collision control unit 1304 notifies the CSMA / CA execution unit 1304 corresponding to the BK queue that a collision has occurred and increases the amount of CW managed by the CSMA / CA execution unit 1304 corresponding to the BK queue.

[0038] The backoff / collision control unit 1304 performs control such as notifying the CSMA / CA execution unit 1303 of changes in channel status, sending transition notifications indicating that a channel attempting channel access has transitioned to an NPCA PCH, and sending re-transition notifications indicating that it has transitioned back to a PCH. When the CSMA / CA execution unit 1303 receives a transition notification or re-transition notification, it updates the backoff parameters as necessary.

[0039] <Connection process and transmission of operational information parameters for NPCA> Next, we will explain the transmission of operational information parameters for NPCA. When AP101 connects to STA102 and STA103, it notifies STA102 and STA103 of various configuration and capability information. Configuration information includes, for example, BSS bandwidth information, EDCA parameters for communication on the BSS PCH, whether UUT mode is enabled or not, and NPCA_CW used in UUT mode. Capability and configuration information may include UHR parameter sets, UHR Capabilities, and UHR Operation. Similarly, when STA102 and STA103 connect to AP101, they also notify AP101 of their own various capability and configuration information. This capability and configuration information may also include UHR parameter sets and UHR Capabilities.

[0040] Figure 4 shows a general example of the connection process between AP101 and STA102 or STA103. The AP periodically sends Beacon frames (S401). The STA also sends a Probe Request frame (S402), and the AP sends a Probe Response frame in response to receiving the Probe Request frame (S403). Subsequently, the STA sends an Association Request frame to the AP (S404), and the AP sends an Association Response frame to the STA (S405). This establishes a link between the AP and the STA, and data communication takes place between the AP and the STA (S406). Here, the AP may notify the STA of the capability information and configuration information described above in the Beacon frame, Probe Response frame, and Association Response frame. The STA may also notify the STA of the capability information and configuration information described above in the Probe Request frame and Association Request frame. In other words, the capability information and configuration information described above are transmitted in the management frame.

[0041] The capability and configuration information transmitted by the AP will be explained using the Probe Response frame as an example. Figure 14 shows an example of a Probe Response frame. The Probe Response frame contains various elements in the order indicated by "Order," such as Timestamp, Beacon Interval, Capability Information, etc. Note that some information may be omitted depending on the configuration. The Beacon frame may also contain the various elements described above. The Timestamp element stores information about the time used for the connected STA to synchronize with the AP. The Beacon Interval element stores information indicating the time interval at which the Beacon frame is transmitted. The Capability Information element stores information about the capabilities of the network or the AP that transmits this frame. The SSID element stores the Service Set Identifier. The Supported Rates and BSS Membership Selectors element stores information indicating supported communication rates, etc. The DSSS Parameter Set element stores parameters related to Direct Sequence Spread Spectrum (DSSS). This element may also store the channel number indicating the BSS PCH. The IBSS Parameter Set element stores parameters related to the Independent BSS (IBSS). The Country element stores regional information, and the Power Constraint element stores information regarding limitations on maximum transmit power. The Channel Switch Announcement element is used to announce changes when the BSS switches to a new channel or to a new channel in a new operating class. The Quiet element stores information about periods when the BSS does not transmit frames.The IBSS DFS element stores information for Dynamic Frequency Selection (DFS) in IBSS. The TPC Report element stores information such as the transmit power when sending this frame. The ERP element stores information related to Extended Rate PHY (ERP). The Extended Supported Rates and BSS Membership Selectors element stores information indicating communication rates, etc. This element can also indicate communication rates not shown by the Supported Rates and BSS Membership Selectors element. The RSN element (RSNE) stores information necessary to establish a Robust Security Network Association (RSNA). The BSS Load element stores information indicating the load in BSS (such as the current number of STAs and traffic levels). The EDCA Parameter Set element stores information necessary for STAs to access EDCA. The HE Capabilities element stores information related to IEEE 802.11ax (High Efficiency (HE)) regarding the network's or the AP's ability to send this frame. The HE Operation element stores information used to control IEEE 802.11ax (HE) operations. The MU EDCA Parameter Set element stores parameter information for Multi-User (MU) EDCA. MU EDCA is a mechanism that makes it difficult for an STA that has been assigned a Resource Unit (RU) and performed UL communication in MU UL communication to access the channel via EDCA for a certain period of time. The Multi-Link element stores information related to multilink communication. The EHT Capabilities element stores information related to IEEE 802.11be (Extremely High Throughput (EHT)) regarding the capabilities of the network or the AP that transmits this frame.The EHT Operation element stores information used to control operations related to IEEE 802.11be (EHT). The TID-To-Link element stores information indicating the association between Traffic ID (TID) and a link. The UHR Capabilities element stores information related to IEEE 802.11bn (UHR) regarding the network's or the AP's ability to transmit this frame. The UHR Operation element stores information used to control operations related to IEEE 802.11bn (UHR). The NPCA EDCA Parameter Set element stores information about the parameters for EDCA in NPCA.

[0042] Furthermore, Probe Request frames, Association Request frames, and Association Response frames may contain information elements similar to those of the Probe Response frame. Association Request frames and Association Response frames may also contain unique elements related to the association. The Status Code field of the Association Response frame stores information such as whether the association was successful or rejected. The AID field stores the Association Identifier (AID) information assigned to the recipient of this frame. Management frames sent by STA differ from management frames sent by AP in that they do not include HE Operation, EHT Operation, or UHR Operation elements. Other fields contain elements similar to those in the Probe Response frame. When connecting to an AP, STA102-103 determine the AP's BSS bandwidth based on various capability and configuration information contained in the Beacon frame, Probe Response frame, and Association Response frame. Then, STA102~103 selects the STA operating channel width as the largest common bandwidth supported by both the AP and STA, based on the identified BSS bandwidth information and the bandwidth information they themselves support. The AP recognizes the STA operating channel width of the connected STA based on the various capability and configuration information included in the Association Request.

[0043] As described above, the management frame transmitted from the AP in this embodiment includes UHR Capabilities and UHR Operation elements in addition to the conventional Capabilities and Operation elements. Furthermore, the management frame transmitted from the STA includes UHR Capabilities in addition to the conventional Capabilities.

[0044] <Elements related to UHR> A configuration example of a UHR Capabilities element and a configuration example of a UHR Operation element are described with reference to FIGS. 5(A) and 5(B). The UHR MAC Capabilities element illustrated in FIG. 5(A) is an element indicating capability information at the MAC layer of a device included in the UHR Capabilities element. The UHR Capabilities element further includes a UHR PHY Capabilities element and the like.

[0045] The UHR MAC Capabilities element is identified as such by, for example, its Element ID and Element ID Extension. Length indicates the size of the element. The UHR MAC Capabilities Information includes subfields 410 to 416. DPS Support 410 indicates whether the communication device supports the Dynamic Power Saving function. In this embodiment, storing 1 for any bit indicates that the function is supported, and storing 0 indicates that the function is not supported. DPS Assisting Support 411 indicates whether the communication device supports transmitting an ICF to bring an STA that is power-saving with the Dynamic Power Saving function back to normal mode. Multi-Link Power Management 412 indicates whether it supports receiving and transmitting Multi-Link Power Management Signals. NPCA Support 413 indicates whether it supports the NPCA function. NPCA Mode2 Support 414 indicates whether it supports NPCA Mode2, an enhanced version of the NPCA function. NPCA Mode2 will be described later. NPCA Mode3 Support 415 indicates whether it supports NPCA Mode3, an enhanced feature described in the modified example. NPCA Mode2 and NPCA Mode3 are capability information indicating whether it supports special NPCA operations when the NPCA PCH is located outside its operating channel width. Therefore, the subfields 414-415 may be configured to store capabilities that are meaningful only to the STA side. In this case, the AP should be configured to store 0 in the field to indicate Reserved. Note that the subfield 415 can be omitted if the modified example described later is not applied.BSR Enhancement Support 416 indicates whether the system supports receiving and transmitting frames that include the BSR Enhancement field.

[0046] Next, the UHR Operation Element will be explained using Figure 5(B). The Element ID and Element ID Extension indicate that this element is a UHR Operation element. Length indicates the size of this element. UHR Operation Parameters 501 includes NPCA Operation Information Present 510. NPCA Operation Information Present 510 may be a 1-bit piece of information indicating whether or not NPCA operation parameters are provided. If NPCA Operation Information Present 510 indicates that NPCA operation parameters are provided, it implicitly indicates that operation with NPCA is enabled. For example, NPCA Operation Information Present 510 is set to "1" if NPCA operation parameters are provided, and to "0" if they are not. When NPCA Operation Information Present 510 is set to "1", NPCA operation parameters are provided in UHR Operation Information 502, which will be described later. On the other hand, if NPCA Operation Information Present510 is set to "0", the NPCA operation parameters will not be provided in UHR Operation Information502, which will be described later. The NPCA operation parameters may be the "NPCA Operation Information" described later. The Basic UHR MCS And Nss Set stores information such as the maximum number of spatial streams for transmission and reception for the UHR MCS value. UHR Operation Information502 includes NPCA Operation Information520 and other information (Other operation information).Note that if NPCA Operation Information Present510 is set to "0", NPCA Operation Information520 will not be included.

[0047] In NPCA Operation Information 520, NPCA Primary Channel 530 specifies one channel within the BSS bandwidth on which the AP operates that should be used as the NPCA PCH. The AP may, for example, search for an uncongested channel in the background and determine a relatively uncongested channel as the NPCA PCH. Alternatively, the NPCA PCH may be specified by user operation. NPCA Minimum Duration Threshold 531 indicates the minimum duration of BSS activity (PPDU or TXOP between BSSs) as a condition for allowing the STA to switch to the NPCA PCH. In other words, the minimum duration is set as a threshold to ensure that NPCA is performed only when the period during which OBSS is expected to be communicating on the BSS PCH (for example, when NAV is set by OBSS communication) is sufficiently long. If the remaining time during which the BSS PCH is occupied by OBSS does not exceed the minimum duration, the STA will not perform NPCA and will wait until the PCH becomes idle. The NPCA Switching Delay 532 indicates the time to be considered as the delay required for configuration changes when the AP switches to a state where NPCA is being executed. The NPCA Switch Back Delay 533 indicates the time to be considered as the delay required for configuration changes when switching back from a state where NPCA is being executed to a state where communication using the BSS's PCH is performed without executing NPCA. In subfields 532 and 533, the delay time is indicated in units of, for example, 4 μs. That is, since each subfield has 6 bits, the range of values ​​that can be represented for the delay time is 0 to 252 μs. For example, to indicate a delay time of 32 μs, you should configure it to store 0b001000.

[0048] UUT Mode534 stores information indicating whether the UUT mode is enabled or not. In the present embodiment, since it is assumed that the UUT mode is uniformly set for all ACs, a case where the UUT Mode is configured by 1 bit is illustrated as an example. However, the present invention is not limited thereto: enabling / disabling of the UUT mode may be determined for each AC, and in one example, the UUT Mode can store information indicating whether the UUT mode is enabled or not for each AC. In this case, the UUT Mode is configured by, for example, 4 bits.

[0049] <Enabling and Disabling NPCA Mode> The frames used to enable and disable NPCA will be explained using Figure 6. Figure 6 shows an example of the Action field of an Action frame that notifies the enablement / disablement of NPCA mode. In this embodiment, this field is referred to as the NPCA Notification frame Action. However, it is not limited to this, and this field may be called by other names. This field includes fields 601 to 604. Specifically, it includes Category 601, Protected UHR Action 602, Dialog Token 603, and NPCA Operation Mode 604. In addition, the Action field in Figure 6 may also include NPCA Parameter Update 605 as a field. Category 601 indicates the category of this Action field. For example, Category 601 stores an identification number corresponding to Protected UHR Action. Protected UHR Action 602 indicates the identifier of this Action field in the Protected UHR Action category. For example, Protected UHR Action 602 stores an identification number indicating the NPCA Notification frame Action field. Dialog Token 603 indicates an identifier used to perform a series of information exchanges between AP101 and STA102 or STA103. For example, an identifier assigned by the requesting communication device is stored in Dialog Token 603. The responding communication device stores the value contained in the received Dialog Token 603 in the Dialog Token of the response frame and transmits it.

[0050] NCPA Operation Mode 611 includes NCPA Mode 611 and NPCA Update Control 612 as subfields. NPCA Mode 611 indicates the intention to use the NPCA function. For example, if STA102 requests to start using the NPCA function, it stores 1 in this subfield. Conversely, if STA102 requests to stop using the NPCA function, it stores 0 in this subfield.

[0051] The NPCA Parameter Update Control 612 indicates whether or not NPCA Parameter Update 605 is active. If NPCA Parameter Update 605 is included in the Action field in Figure 6, 1 is stored in this subfield 612. On the other hand, if NPCA Parameter Update 605 is not included in the Action field in Figure 6, 0 is stored in this subfield 612. When the use of the NPCA function is stopped, it is not necessary to transmit parameters for NPCA. Therefore, if NPCA Mode 611 is set to 0, NPCA Parameter Update Control field 612 is also set to 0.

[0052] NPCA Parameter Update 605 includes subfields 621-624 that store the operational parameters for the NPCA function used when the STA utilizes the NPCA function. Additionally, subfields 625-626 are included when performing the modifications described later.

[0053] The NPCA Switching Delay 621 indicates the time considered as the delay required for configuration changes when the STA switches to an NPCA PCH inside the STA operating channel width. The NPCA Switch Back Delay 621 indicates the time considered as the delay required for configuration changes when the STA switches back from an NPCA PCH inside the STA operating channel width to a BSS PCH. In subfields 621 and 622, the delay time is indicated in units of, for example, 4 μs. That is, since the subfield is 6 bits, the range of representable delay time is 0 to 252 μs.

[0054] Next, NPCA Mode2 Switching Delay 623 indicates the time considered as the delay required for configuration changes when the STA switches back from an NPCA PCH outside the STA operating channel width to a BSS PCH. NPCA Mode2 Switch Back Delay 624 indicates the time considered as the delay required for configuration changes when the STA switches back from an NPCA PCH outside the STA operating channel width to a BSS PCH. Subfields 625-626 are: The delay times required for switching and switchback used in NPCA Mode 3, an enhanced function explained in the modified example, are shown. Subfields 625-626 can be omitted if the modified example is not implemented.

[0055] In subfields 623-626, the delay time is indicated in units of, for example, 8 μs. Since each subfield is 6 bits, the range of delay time that can be represented is 0 to 504 μs. By adopting the field configuration shown in Figure 6, it becomes possible to notify the AP that different delay times are used depending on whether the NPCA PCH is located inside or outside the STA operating channel width. Furthermore, considering that switching to the outside takes a relatively long time, the delay time signaling method is designed so that the range of delay time that can be represented in 623-626 is larger than the range of delay time that can be represented in 621-622. As an example, the unit time for the switching delay and switchback delay of NPCA Mode 2 and Mode 3 is set to 8 μs, but it is not limited to this. For example, a unit time of 16 μs or 32 μsec may be used. 621-622 can also be called the switching delay and switchback delay corresponding to the first NPCA mode. 623-624 can be described as switching delays or switchback delays corresponding to the second NPCA mode. 625-627 can be described as switching delays or switchback delays corresponding to the third NPCA mode.

[0056] Next, the NPCA Operation of this embodiment will be explained using Figure 7. Figure 7 is a schematic diagram showing the relationship between the BSS bandwidth (BSS operating channel width), the STA operating channel width, and the conditions for whether or not a transition to the NPCA PCH is possible. Figure 7 illustrates a case where AP101 is operating with a BSS bandwidth of 160 MHz and the NPCA PCH is located on a channel 60 MHz away from the PCH of the BSS band. It also illustrates a case where the first STA connected to AP101 is operating with an STA operating channel width of 160 MHz. Furthermore, it illustrates a case where the second STA connected to AP101 is operating with an STA operating channel width of 80 MHz and the third STA connected to AP101 is operating with an STA operating channel width of 40 MHz. Finally, it shows a case where the fourth STA connected to AP101 is operating with an STA operating channel width of 20 MHz.

[0057] In cases where an NPCA PCH is located within the STA operating channel width being used by an STA, any STA that supports NPCA can participate in NPCA operations. In the illustrated scenario, an STA operating with a 160MHz STA operating channel width and an STA operating with an 80MHz STA operating channel width can participate in NPCA operations as long as they support the basic NPCA functions.

[0058] On the other hand, in cases where the NPCA PCH is located outside the STA operating channel width being used by the STA, STAs that do not support the enhanced function NPCA Mode 2 are configured not to participate in NPCA operations. Therefore, under the illustrated conditions, STAs operating with a 40MHz STA operating channel width and STAs operating with a 20MHz STA operating channel width will not participate in NPCA operations unless they support NPCA Mode 2. Conversely, STAs that support NPCA Mode 2 can attempt to participate in NPCA operations even if the NPCA PCH is located outside the STA operating channel width being used by the STA.

[0059] The control, including the distinction in usage explained in the schematic diagram of Figure 7, will be explained in more detail using the flowcharts in Figures 9 to 11. First, using Figures 9(A) and 9(B), examples of the processing flow performed by AP101 and STA102 to STA103 will be explained. Each process in Figure 9(A) is executed by the processor of the control unit 302 of AP101 executing a computer program stored in the memory unit 301. Similarly, each process in Figure 9(B) is executed by the processor of the control unit 302 of STA102 to STA103 executing a computer program stored in the memory unit 301. In any case of communication equipment, some processes such as transmission and modulation can be realized through the cooperation of the processor of the control unit 302 and the various processors, ASICs, DSPs, FPGAs, and antennas that constitute the communication unit 306. Some processes may also be realized through cooperation with the ASICs, DSPs, FPGAs, etc. that constitute the control unit 302. However, this is not limited to the above, and each communication device may execute each process by coordinating the control unit, such as an ASIC or processor, inside the communication unit 306 with the antenna.

[0060] As shown in Figure 9(A), AP101 periodically transmits a Beacon frame containing a UHR Capabilities element and a UHR Operation element (S901). In this embodiment, AP101 transmits a Beacon frame with NPCA Support 413 set to 1 and NPCA Operation Information Present 510 set to 1. In addition, as described above, operational information is stored in subfields such as 520. Specifically, information identifying the NPCA PCH selected based on the surrounding conditions and user settings, and NPCA threshold information are stored. Information such as whether the switching delay, switchback delay, and UUT Mode are enabled is also stored as operational information. The Beacon frame may also include an NPCA EDCA Parameter Set element for determining CW in NPCA. This element for determining CW may be placed after the UHR Capabilities element and the UHR Operation element. This allows the STA to check the UHR Operation element and, if UUT mode is enabled, to obtain the parameters included in the NPCA EDCA Parameter Set element. Furthermore, when AP101 receives a Probe Request frame from STA, it may send a Probe Response frame containing the above-mentioned elements. Also, when AP101 receives an Association Request frame from STA, it may send an Association Response frame containing the above-mentioned elements. AP101 may send the above-mentioned elements in one of the Beacon frame, Probe Response frame, or Association Response frame, or it may send the above-mentioned elements in two or more frames. In other words, each element may be sent to STA in only one type of frame, or each element may be repeatedly sent to STA in multiple types of frames.Furthermore, when AP101 receives a Reassociation Request frame, it may send a Reassociation Response frame containing the elements described above. AP101 then stores the NPCA capability of the STA in the storage unit 303, associating it with the STA that sent the request. When AP101 receives an action frame indicating the activation or deactivation of NPCA, it stores information indicating whether the NPCA mode is enabled, as well as each switching delay and each switchback delay, as associated with the STA that sent the request. This stored information is used by AP101 to determine whether to treat the STA as a candidate STA to be transmitted in the NPCA PCH when AP101 transitions to the NPCA PCH. An action frame indicating the activation or deactivation of NPCA is, for example, the action frame shown in Figure 6. This stored information is also used by the candidate STA to be transmitted to determine when it will be ready to communicate by transitioning to the NPCA PCH. In other words, AP101 uses the stored information to send data to STA or request trigger-based uplink communication when STA has transitioned to NPCA PCH and is ready for communication.

[0061] STA102~STA103 receive Beacon frames, Probe Response frames, and Association Response frames transmitted from AP101. As shown in Figure 9(B), STA102~STA103 identify and store the NPCA PCH, AP switching delay, switchback delay, and the enabled / disabled status of the UUT mode in BSS from at least one of these frames (S911). For example, STA102~STA103 check the NPCA Operation Information contained in the UHR Operation element in Figure 5(B) to identify the enabled or disabled status of the NPCA PCH, various delays, and UUT mode. STA102~STA103 also check the NPCA EDCA Parameter Set element from at least one of these frames and store or update the NPCA EDCA parameters for accessing the NPCA PCH. The information stored or updated in Figure 9(B) is referenced as appropriate in the processes shown in Figures 10 and 11, which will be described later.

[0062] Figures 10 and 11 show an example of the processing flow when STA102 to STA103 transmit data (PPDU). Each process in Figures 10 and 11 is executed by the processor of the control unit 302 of STA102 to STA103 executing a computer program stored in the memory unit 301. Some processes, such as transmission and modulation, can be realized through the cooperation of the processor of the control unit 302, various processors, ASICs, DSPs, FPGAs, and antennas that constitute the communication unit 306, and the ASICs, DSPs, FPGAs, etc. that constitute the control unit 302. However, it is not limited to this, and STA102 to STA103 may execute each process by coordinating the control unit such as the ASIC or processor inside the communication unit 306 with the antenna. Hereafter, STA102 to STA103 will simply be referred to as "STA". For the sake of simplicity, STA102 to STA103 will be collectively referred to as "STA" below.

[0063] The STA monitors the transmission queue and checks whether the transmission data (MAC frame) has been stored in the transmission queue by the higher layer (S1001). For example, when a video streaming application starts streaming video, the data corresponding to the video data obtained from the camera equipped with the STA is classified as VI by the data categorization unit 1301 and stored in the VI queue. Also, when transmitting audio data using a VoIP (Voice over Internet Protocol) application, the data corresponding to that audio data is classified as VO by the data categorization unit 1301 and stored in the VO queue. Note that the determination process in S1001 may be executed in parallel by multiple CSMA / CA execution units 1303 corresponding to each queue.

[0064] If the STA confirms that the transmitted data has been stored (YES in S1001), the STA determines backoff parameters consisting of the AIFS and the backoff value indicated by the backoff counter, based on the EDCA parameters corresponding to the AC of the relevant queue. Then, it performs the backoff process based on the determined backoff parameters (S1002). The backoff counter is determined to have randomness within the range of the current contention window size (CWsize) and aCWmin corresponding to the access category. aCWmin is an abbreviation for adaptive Contention Window minimum. The initial value of CWsize (i.e., the CWsize used when no collisions occur) is aCWmin. CWsize is doubled each time a collision occurs. That is, in environments where collisions occur frequently, the range of candidates for random backoff increases, and the occurrence of collisions is suppressed. The STA calculates the backoff counter to be used by calculating a random number that follows a uniform distribution within the range of the current contention window size (CWsize) and aCWmin corresponding to the access category, which is a set of EDCA parameters. The backoff process is briefly explained below. After setting the backoff parameters, the STA performs either a wait process for the transmission wait time equivalent to AIFS or a decrement process for the backoff counter, provided that the channel state of the BSS PCH is idle. The STA first performs a wait process for the transmission wait time equivalent to AIFS, and when the transmission wait time equivalent to AIFS becomes zero, it performs a decrement process for the backoff counter. Before the backoff counter becomes zero (NO in S1004), the STA monitors whether another STA (AP STA or non-AP STA) has acquired a transmission opportunity (S1005). That is, the STA performs carrier sensing on the BSS PCH. Then, if the PCH has not changed from idle to busy, the STA determines that no other STA has acquired a transmission opportunity (NO in S1005) and returns to processing S1002.Furthermore, if the STA determines from the results of this analysis that the radio frame is destined for its own device, it performs processing such as demodulation of the radio frame (not shown in the diagram). If the STA determines that the backoff counter has reached zero without any other STAs having obtained a transmission opportunity (NO in S1005, YES in S1004), it transmits the data stored in the queue of the corresponding AC on the BSS PCH (S1008). The STA transmits data in UHR PPDU format on one or more channels, including at least the BSS PCH. Furthermore, when transmitting data, the STA determines whether the transmitted data has collided with data transmitted by other STAs (S1009). If the STA determines that a data collision has occurred (YES in S1009), it increases the CWsize (S1010). Specifically, the STA changes the CWsize to twice its current size. On the other hand, if the STA determines that no data collision occurred (NO in S1009), it determines that data transmission was successful and initializes CWsize to aCWmin (S1011). Then, after updating or initializing CWsize, the STA determines whether or not to turn off the power (to terminate communication) (S1012). For example, if the STA receives a user command to turn off the power, it may determine to turn off the power. If the STA determines to turn off the power (YES in S1012), it performs a shutdown process (not shown) and terminates the series of transmission controls. On the other hand, if the STA determines not to turn off the power (not to terminate communication) (NO in S1012), it returns to processing S1001.

[0065] On the other hand, if the STA determines that another STA has acquired an opportunity to transmit a wireless frame not addressed to its own device before the backoff counter reaches zero (NO in S1004) (YES in S1005), it sets the NAV in the BSS PCH (S1006). In other words, it sets the BSS PCH_NAV. The STA sets the length of the NAV based on information such as the Duration field of the PPDU from the other STA. The STA also discards the current BSS PCH backoff parameter. Then, the STA performs a determination process to determine whether to transition to the NPCA PCH and, if it determines to transition, performs a transmission control process (S1007). Once the process described later using Figure 11 is completed, the STA returns to S1001.

[0066] Next, the determination and transmission control in S1007 will be explained using Figure 11. First, the STA determines whether its own NPCA mode is enabled (S1101). If it determines that the NPCA mode is enabled (YES in S1101), it determines whether the destination NPCA PCH is within the STA operating channel operated by the STA (S1102). On the other hand, if the STA determines that the NPCA mode is not enabled (NO in S1101), it returns to S1001 without transitioning to the NPCA PCH.

[0067] If the STA determines that the destination NPCA PCH is within the STA operating channel operated by the STA itself (YES in S1102), it performs the transition determination in S1103. On the other hand, if the STA determines that the destination NPCA PCH is outside the STA operating channel operated by the STA itself (NO in S1102), it determines whether it supports NPCA Mode 2 (S1104).

[0068] First, let's explain the transition determination process in S1103. The STA determines whether the currently set BSS PCH_NAV period is greater than the period obtained by adding the Minimum Duration Threshold notified by the AP to the STA's own switching delay. If it is determined to be greater (YES in S1103), it performs the transition process to the NPCA Primary Channel (S1106a). On the other hand, if it is not determined to be greater (NO in S1103), the process returns to S1001 without performing the transition to the NPCA PCH.

[0069] Next, we will explain the processing from S1104 onwards. If STA determines that it supports NPCA Mode 2 (YES in S1104), it performs the transition determination shown in S1105. If STA determines that it does not support NPCA Mode 2 (NO in S1104), it returns to S1001 without transitioning to NPCA PCH.

[0070] Next, we will explain the transition determination process in S1105. The STA determines whether the currently set BSS PCH_NAV period is greater than the period obtained by adding the Minimum Duration Threshold notified by the AP to the STA's own switching delay for NPCA Mode2. If it is determined to be greater (YES in S1105), it performs the transition process to the NPCA Primary Channel (S1106a). On the other hand, if it is not determined to be greater (NO in S1105), the process returns to S1001 without performing the transition to NPCA PCH.

[0071] Once the transition process to the NPCA Primary Channel shown in S1106a is complete, the STA determines whether UUT mode is enabled based on the stored information (S1106b). If the STA determines that UUT mode is enabled (YES in S1106b), it performs the process of determining the backoff parameters in the NPCA PCH (S1107). On the other hand, if the STA determines that UUT mode is not enabled (UUT mode is disabled) (NO in S1106b), it performs the process of waiting for instructions or frames from the AP (S1106c). Specifically, upon receiving a Basic type trigger frame addressed to itself from AP101, the STA sends uplink data to AP101. This data is sent in UHR TB (Trigger-based) PPDU format. Furthermore, if the STA receives downlink data addressed to itself from the AP, it performs the process of passing this data to the protocol stack of a higher layer, such as the IP layer, as appropriate (not shown in the diagram). STA proceeds to S1116 when the series of data exchanges with AP is completed, or when the BSS PCH_NAV period becomes shorter.

[0072] Next, the NPCA EDCA access process when UUT mode is enabled will be explained in detail. The STA determines the backoff parameters for channel access in the NPCA PCH (S1107). The STA identifies the value of AIFSN in the BSS PCH. For example, the STA uses the value of AIFSN in the Basic EDCA parameter set in the BSS PCH as the AIFSN when accessing the channel with NPCA. Then, the STA sets the backoff parameters corresponding to each AC using that AIFSN and the CW parameters (ECWmin and ECWmax) of the aforementioned NPCA EDCA parameter set. That is, multiple CSMA / CA execution units 1303 corresponding to each AC in the STA can each identify the backoff parameters using the AIFSN and CW parameters for their respective ACs. Note that only the CSMA / CA execution unit 1303 for ACs with queued transmission data identifies these backoff parameters; the CSMA / CA execution units 1303 for other ACs do not need to identify the backoff parameters.

[0073] After setting the backoff parameters, the STA performs either a wait process for the transmission waiting time equivalent to AIFS or a decrement process for the backoff counter, provided that the channel state of the NPCA PCH is idle (S1108). Before the backoff counter reaches zero (NO in S1109), the STA monitors whether another STA (AP STA or non-AP STA) has acquired a transmission opportunity (S1110). That is, the STA performs carrier sensing on the NPCA PCH. If the NPCA PCH has not changed from idle to busy, the STA determines that no other STA has acquired a transmission opportunity (NO in S1110) and returns to processing S1108. If the STA determines that the backoff counter has reached zero without any other STA acquiring a transmission opportunity (NO in S1110, YES in S1109), it transmits the data stored in the queue of the corresponding AC on the NPCA PCH (S1112). The STA transmits data in UHR PPDU format on one or more NPCHs that include at least an NPCA PCH but do not include a BSS PCH. These one or more NPCHs are channels bonded to a channel in a frequency domain continuous with the NPCA PCH. When transmitting data, the STA determines whether the transmitted data has collided with data transmitted by another STA (S1113). If the STA determines that a data collision has occurred (YES in S1113), it increases the CWsize (S1115). Specifically, the STA changes the CWsize to twice its current size. On the other hand, if the STA determines that no data collision has occurred (NO in S1113), it determines that the data transmission was successful and initializes the CWsize to aCWmin (S1114). Then, after updating or initializing the CWsize, the STA determines whether to continue transmission control on the NPCA PCH (S1116). For example, if STA determines that the period set in S1006 for BSS PCH_NAV has ended, it decides not to continue transmission control on NPCA PCH. Then, STA switches back to BSS PCH and changes the settings to perform communication control on BSS PCH.The STA controls the setting of backoff parameters, including AIFS and the backoff counter, based on the Basic EDCA parameter set (S1117), and returns processing to S1102. If the STA does not have any data to transmit, it may skip the backoff parameter setting control and move processing to S1001. The processing in S1116 and S1117 can also be described as control to terminate the control that attempts to acquire a transmission opportunity on the NPCH before the NAV period set on the BSS PCH expires. The STA may also take into account the waiting time required for its own channel switchback and perform the switchback at a timing that allows for a normal return to the BSS PCH just before the NAV period set on the BSS PCH expires.

[0074] On the other hand, if the STA determines that another STA has obtained an opportunity to transmit a wireless frame not addressed to its own device before the backoff counter reaches zero (NO in S1109) (YES in S1110), it sets the NAV in the NPCA PCH (S1111). The STA sets the length of this NAV in the NPCA PCH based on information such as the Duration field of the PPDU from the other STA. Then, the STA moves the process to S1116.

[0075] As described above, the STA according to this embodiment can transmit the switching delay and switchback delay to the AP when switching to an NPCA PCH inside the operating STA operating channel width. Furthermore, the STA according to this embodiment can pre-transmit the switching delay and switchback delay to the AP when switching to an NPCA PCH outside the operating STA operating channel width. In addition, when actually attempting NPCA operation, the STA can appropriately determine whether or not to transition to the NPCA PCH by taking into account the location of the NPCA PCH, the capabilities of the STA itself, and the Minimum Duration Threshold transmitted by the AP. Therefore, NPCA operation can be operated more appropriately.

[0076] <Example 1> In the above-described embodiment, we explained the technique of using the basic NPCA function and the enhanced function, NPCA MMode2. In the modified example, we further define NPCA Mode3 and configure the system to use three modes. Since the hardware and functional configuration of the modified example is the same as in the above-described embodiment, we will explain the differences from the above-described embodiment using Figures 8 and 12.

[0077] Figure 8 is a schematic diagram showing the relationship between the BSS bandwidth (BSS operating channel width), the STA operating channel width, and the conditions for transitioning to the NPCA PCH in a modified example. In this modified example, we focus on the fact that in 160MHz and 320MHz BSS bands, the target center frequencies of the BSS PCH and NPCA PCH are significantly different depending on the STA operating channel width and the position of the NPCA PCH. More specifically, we focus on the fact that in order to significantly change the center frequency that the antenna or analog circuit must focus on, the waiting time such as switching delay or switchback delay may become large. Based on this, we define NPCA Mode 3, which can be used when the BSS band is operated using a 160MHz bandwidth or when the BSS band is operated using a 320MHz bandwidth.

[0078] NPCA Mode 3 is a more enhanced feature compared to NPCA Mode 2, and STAs may optionally support this feature. In this modification, further restrictions are placed on participation in NPCA operations in a specific case where the NPCA PCH is located in the Secondary 80MHz or Secondary 160MHz region and this location is outside the operating channel width of the STA. Specifically, in this specific case, only STAs that support NPCA Mode 3 are allowed to participate in NPCA operations.

[0079] If the NPCA PCH is located within the operating channel width used by the STA, then, as in the embodiments described above, any STA that supports the basic NPCA mode can participate in NPCA operations. Furthermore, even if the NPCA PCH is located outside the operating channel width used by the STA, a second specific case is imposed where it is located within Primary 80MHz or Primary 160MHz, with more lenient constraints. Specifically, participation in NPCA operations is permitted only if the STA supports NPCA Mode 2 as described in the embodiments described above. In the aforementioned specific case, participation in NPCA operations is permitted only if the STA supports NPCA Mode 3.

[0080] Under the conditions shown in Figure 8, an STA operating at 160MHz bandwidth can participate in NPCA operations if it supports only the basic NPCA mode. On the other hand, STAs operating at 80MHz, 40MHz, and 20MHz bandwidths cannot participate in NPCA operations unless they support NPCA Mode 3.

[0081] Whether or not NPCA Mode 3 is supported can be indicated in the NPCA Mode 3 Support subfield in Figure 5(A). Setting this subfield to "1" indicates that NPCA Mode 3 is supported, and setting it to "0" indicates that NPCA Mode 3 is not supported. In addition, the switching delay and switchback delay used in NPCA Mode 3 can be indicated in subfields 625-626 in Figure 6.

[0082] The differences between the first embodiment and this modified example will be explained. The STA differs from the first embodiment in that it includes capability information and setting information for the NPCA Mode3 function, indicated by dashed lines, for the elements described in Figures 5(A) and 6. Furthermore, in this modified example, additional judgment processing is performed in the transition determination to NPCA PCH shown in Figure 11 of the first embodiment. Figure 12 shows an example of the processing flow that is performed in place of the processing shown in Figure 11 of the first embodiment in this modified example. Specifically, the STA additionally performs the judgment processing S1151 to S1153, indicated by dashed lines in Figure 12. Note that the other processing S1101 to S1117 is the same as in the first embodiment, so its explanation is omitted.

[0083] If STA does not determine in S1102 that the NPCA PCH is within the STA's operating channel (NO in S1102), it determines whether the NPCA PCH is located at Secondary 80MHz or Secondary 160MHz (S1151). This determination is made based on stored information. If STA determines that the NPCA PCH is located at Secondary 80MHz or Secondary 160MHz (YES in S1151), it determines whether it supports NPCA Mode 3 (S1152). On the other hand, if STA determines that the NPCA PCH is not located at Secondary 80MHz or Secondary 160MHz (NO in S1151), it proceeds to S1004. In other words, if the NPCA PCH is located at Primary 80MHz or Primary 160MHz, it proceeds to the determination process for whether it supports NPCA Mode 2 as described in the first embodiment.

[0084] Next, if STA determines that it supports NPCA Mode 3 (YES in S1152), it performs a transition check for NPCA Mode 3 (S1153). On the other hand, if STA determines that it does not support NPCA Mode 3 (No in S1152), it returns to S1001 without performing a transition to NPCA PCH.

[0085] Finally, let's explain the transition determination process in S1153. The STA determines whether the currently set BSS PCH_NAV period is greater than the period obtained by adding the Minimum Duration Threshold notified by the AP to the STA's own switching delay for NPCA Mode 3. If it is determined to be greater (YES in S1153), it performs the transition process to the NPCA Primary Channel (S1106a). On the other hand, if it is not determined to be greater (NO in S1153), it returns to S1001 without performing the transition to NPCA PCH.

[0086] The process described above enables NPCA operations that take into account cases where the target center frequencies of the BSS PCH and NPCA PCH are significantly different. Furthermore, STAs that can perform frequency shifts with low latency, or STAs that are expected to benefit from NPCA even with slightly increased latency, can benefit from NPCA by declaring their support for NPCA Mode 3 functionality. In this case, the latency times for switching to the NPCA PCH and switching back from the NPCA PCH can be notified to the AP in advance in NPCA Mode 3, allowing for proper communication after the transition.

[0087] <Modification 2> In the first embodiment and modification 1, an example was given where the STA negotiates the enable / disable status of NPCA with the AP using the action frame shown in Figure 6, but the procedure for enabling / disabling NPCA is not limited to this. For example, the connection procedure may be configured to declare in advance whether to enable or disable the mode, similar to how the AP uses the UHR Operation Element to notify the AP of the enabled / disabled status of the NPCA mode being operated in the AP's BSS. In this case, the STA provides a UHR STA Operation Request element, etc., after the UHR Capabilities element. Then, the STA should send a frame containing the information of fields 604 and 605 shown in Figure 7 in the UHR STA Operation Request element when connecting. In other words, the Probe Request frame or Association Request frame can include in advance whether to enable or disable the mode. Based on this information, the AP determines whether the STA has enabled or disabled the NPCA mode, and if it has enabled, manages the switching delay and switchback delay in association with the STA that made the request. When this process is performed, the overhead of frame exchange required to activate the mode can be reduced in STAs that want to enable NPCA mode from the initial connection. Alternatively, the activation / deactivation of NPCA mode can be communicated using the A-Control field of the MAC frame. The type field of the Frame Control field of the MAC frame stores "10" to indicate that it is a data frame. The data frame contains an HT Control field. The first two bits of the HT Control field indicate the type of the HT Control field. Specifically, the first two bits are used to identify whether it is an HT / VHT / HE type. If "11" is stored in this value, it contains an A-Control field. The A-Control field contains a Control ID field and a Control Information field.For example, by storing "11" in the Control ID field, it can be indicated that this field allows switching between enabling and disabling NPCA. In this case, the subsequent Control Information field stores operational information for NPCA. Specifically, an NPCA Mode field can be provided and configured to include the information from fields 604 and 605 shown in Figure 7. This modified version allows the enabling or disabling of NPCA mode to be communicated using the A-Control field of the data frame. By adopting this procedure, it becomes possible to send a request to change the operating mode of the NPCA function when transmitting a data frame. This process has the effect of reducing communication overhead compared to simply exchanging only a request to change the operating mode of the NPCA function.

[0088] <Other Embodiments 1> The present invention can also be realized by supplying a program that implements one or more of the functions of the above-described embodiments to a system or device via a network or storage medium, and by having one or more processors in the computer of that system or device read and execute the program. It can also be realized by a circuit (e.g., an ASIC) that implements one or more functions.

[0089] <Other Embodiments 2> Furthermore, the disclosure of this embodiment includes the following configuration.

[0090] (Composition 1) Station device, A station device characterized by having a transmission control means for transmitting a frame to an access point device that includes a first NPCA Switching Delay and a first NPCA Switch Back Delay related to an NPCA (Non-primary channel access) operation that switches to another channel inside the BSS operating channel of an access point providing a BSS (Basic Service Set) to which the station device is connected, which is a channel different from the channel to which the station device is operating, a second NPCA Switching Delay different from the first NPCA Switching Delay, and a second NPCA Switch Back Delay different from the first NPCA Switch Back Delay.

[0091] (Configuration 2) The first NPCA Switching Delay indicates the delay time required when the station device transitions to an NPCA Primary Channel located within the operating channel width used for communication with the access point device, and the first NPCA Switch Back Delay indicates the delay time required when switching back from the inner NPCA Primary Channel to the BSS Primary Channel located within the BSS operating channel. The station device according to Configuration 1, characterized in that the second NPCA Switching Delay indicates the delay time required when the station device transitions to an NPCA Primary Channel located outside the operating channel width used for communication with the access point device, and the second NPCA Switch Back Delay indicates the delay time required when switching back from the outside NPCA Primary Channel to the BSS Primary Channel.

[0092] (Composition 3) The frame includes a first field indicating the first NPCA Switching Delay, a second field indicating the first NPCA Switch Back Delay, a third field indicating the second NPCA Switching Delay, and a fourth field indicating the second NPCA Switch Back Delay. The station device according to configuration 1 or 2, characterized in that the frame is configured such that the maximum delay time that can be shown in the third and fourth fields is greater than the maximum delay time that can be shown in the first and second fields.

[0093] (Composition 4) The station device according to any one of configurations 1 to 3, characterized in that the frame further includes a third NPCA Switching Delay and a third NPCA Switch Back Delay.

[0094] (Composition 5) The station device according to any one of configurations 1 to 4, further characterized in that the transmission control means transmits to the access point a management frame including a UHR MAC Capabilities element containing at least information indicating whether the station device supports the function of transitioning to an NPCA Primary Channel located outside the operating channel width used for communication with the access point device.

[0095] (Composition 6) A control method for a station device, A control method characterized by having a transmission control step of transmitting a frame to an access point device, which includes a first NPCA Switching Delay and a first NPCA Switch Back Delay related to an NPCA (Non-primary channel access) operation that switches to another channel inside the BSS operating channel of an access point providing a BSS (Basic Service Set) to which the station device is connected, which is a channel different from the channel to which the station device is operating, a second NPCA Switching Delay different from the first NPCA Switching Delay, and a second NPCA Switch Back Delay different from the first NPCA Switch Back Delay.

[0096] (Composition 7) A program to cause a computer to execute the control method of the station device described in Configuration 6. [Explanation of Symbols]

[0097] 101 AP 102 STA 103 STA 302 Control Unit

Claims

1. Station device, A station device characterized by having a transmission control means for transmitting a frame to an access point device that includes a first NPCA Switching Delay and a first NPCA Switch Back Delay related to an NPCA (Non-primary channel access) operation that switches to another channel inside the BSS operating channel of an access point providing a BSS (Basic Service Set) to which the station device is connected, which is a channel different from the channel on which the station device is operating, and which includes a second NPCA Switching Delay different from the first NPCA Switching Delay and a second NPCA Switch Back Delay different from the first NPCA Switch Back Delay.

2. The first NPCA Switching Delay indicates the delay time required when the station device transitions to an NPCA Primary Channel located within the operating channel width used for communication with the access point device, and the first NPCA Switch Back Delay indicates the delay time required when switching back from the NPCA Primary Channel located within the BSS operating channel to the BSS Primary Channel located within the BSS operating channel. The station device according to claim 1, characterized in that the second NPCA Switching Delay indicates the delay time required when the station device transitions to an NPCA Primary Channel located outside the operating channel width used for communication with the access point device, and the second NPCA Switch Back Delay indicates the delay time required when switching back from the outside NPCA Primary Channel to the BSS Primary Channel.

3. The frame includes a first field indicating the first NPCA Switching Delay, a second field indicating the first NPCA Switch Back Delay, a third field indicating the second NPCA Switching Delay, and a fourth field indicating the second NPCA Switch Back Delay. The station device according to claim 1, characterized in that the frame is configured such that the maximum delay time that can be shown in the third and fourth fields is greater than the maximum delay time that can be shown in the first and second fields.

4. The station device according to claim 1, characterized in that the frame further includes a third NPCA Switching Delay and a third NPCA Switch Back Delay.

5. The station device according to any one of claims 1 to 4, further characterized in that the transmission control means transmits to the access point a management frame including a UHR MAC Capabilities element which contains at least information indicating whether the station device supports the function of transitioning to an NPCA Primary Channel located outside the operating channel width used for communication with the access point device.

6. A control method for a station device, A control method characterized by having a transmission control step of transmitting a frame to an access point device, which includes a first NPCA Switching Delay and a first NPCA Switch Back Delay related to an NPCA (Non-primary channel access) operation that switches to another channel inside the BSS operating channel of an access point providing a BSS (Basic Service Set) to which the station device is connected, on a channel different from the channel on which the station device is operating, and which includes a second NPCA Switching Delay different from the first NPCA Switching Delay and a second NPCA Switch Back Delay different from the first NPCA Switch Back Delay.

7. A program for causing a computer to execute the control method of the station device described in claim 6.

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