Communication device, communication method, and program

Abstract

According to the present invention, a communication device that functions as an access point that conforms to IEEE 802.11 standards performs communication over a single communication link that is constituted by a first channel that is used to acquire transmission rights and one or more second channels using one of a first communication scheme that uses at least the first channel and a second communication scheme that, during periods during which the first channel cannot be used, uses a prescribed channel from among the one or more second channels to acquire transmission rights without using the first channel. To another communication device that operates as a station, the communication device transmits a management frame that includes a UHR Capabilities element and an element that comes after the UHR Capabilities element and stores parameters that are to be used when the station acquires transmission rights on the basis of EDCA under the second communication scheme.

Description

Communication device, communication method, and program

[0001] The present disclosure relates to communication control technology in a wireless LAN.

[0002] As a communication standard related to a 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 have been studied.

[0003] U.S. Patent Application Publication No. 11696353

[0004] Patent Document 1 describes a technique in which a communication device performs communication using another channel when it cannot use the Primary Channel used to acquire a transmission right.

[0005] The present disclosure provides a communication control technology suitable for a communication system using a communication link composed of a plurality of channels.

[0006] A communication device according to one aspect of the present disclosure is a communication device that functions as an access point compliant with the IEEE 802.11 standard, and has communication means for communicating in a communication link comprising a first channel used to acquire transmission rights and one or more second channels different from the first channel, using either a first communication method that uses at least the first channel, or a second communication method that acquires transmission rights using a predetermined channel from the one or more second channels without using the first channel during periods when the first channel cannot be used, wherein the communication means communicates to other communication devices operating as stations, an Ultra High Reliability (UHR) Capabilities element, and a station located after the UHR Capabilities element, where the station is using the Enhanced Distributed Channel in the second communication method. A management frame is sent that includes an element containing parameters used when acquiring transmission rights based on Access (EDCA).

[0007] According to this disclosure, it becomes possible to perform communication control suitable for communication systems that use communication links composed of multiple channels.

[0008] Other features and advantages of the technical ideas derived from this disclosure will become apparent from the following description with reference to the attached drawings. In the attached drawings, the same or similar components are given the same reference numeral.

[0009] The attached drawings are included in the specification and constitute part thereof, illustrating embodiments in this disclosure and used to explain the technical ideas derived from this disclosure together with their descriptions. Figure 1 is a diagram showing an example configuration of a wireless communication system. Figure 2A is a schematic diagram showing an example of a time chart when a communication device transmits data. Figure 2B is a schematic diagram showing an example of a time chart when a communication device transmits data. Figure 3 is a diagram showing an example of the hardware configuration of a communication device. Figure 4 is a diagram showing an example of the functional configuration of a communication device. Figure 5 is a diagram showing an example of the communication processing flow by NPCA. Figure 6 is a diagram showing an example of the channel access function by EDCA of a communication device. Figure 7 is a diagram showing an example of the communication processing flow. Figure 8 is a diagram schematically showing the connection processing flow between AP and STA. Figure 9 is a diagram schematically showing the contents of a Probe Response frame or Beacon frame. Figure 10 is a diagram schematically showing the contents of an Association Response frame. Figure 11 is a diagram showing an example configuration of a UHR Operation element. Figure 12 shows an example configuration of an EDCA Parameter Set element. Figure 13 shows an example configuration of a MU EDCA Parameter Set element. Figure 14 shows an example configuration of an NPCA EDCA Parameter Set element. Figure 15 shows an example GUI for setting EDCA parameters. Figure 16 shows an example of the communication processing flow when UUT mode is disabled. Figure 17 shows an example of the communication processing flow when UUT mode is enabled. Figure 18A shows an example of the processing flow executed by the AP. Figure 18B shows an example of the processing flow executed by the STA. Figure 19A shows an example of the processing flow when the STA sends data. Figure 19B shows an example of the processing flow when the STA sends data. Figure 20 shows an example of the processing flow when the STA sends data. Figure 21A shows another example configuration of the NPCA EDCA Parameter Set element. Figure 21B shows another example configuration of the NPCA EDCA Parameter Set element.

[0010] The embodiments will be described in detail below with reference to the attached drawings. Note that the following embodiments do not limit the scope of the claims. While the embodiments describe multiple features, not all of these features are necessary, 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.

[0011] (System Configuration) Figure 1 shows an example of the 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). Hereinafter, the access point may be referred to as AP STA, and the stations may be referred to as non-AP STA. AP101 and STA102 to STA103 are communication devices capable of performing wireless communication in accordance with the IEEE 802.11 standard series. In this embodiment, when it is not necessary to distinguish between AP101 and STA102 to STA103, they may be collectively referred to as communication devices. IEEE is an abbreviation for Institute of Electrical and Electronics Engineers. Figure 1 shows a configuration in which STA102 to STA103 participate in a network 111 constructed by AP101. Network 111 may also be called a Basic Service Set (BSS). In Figure 1, Network 131, which is composed of AP 121 and includes STA 122, is located near Network 111, which is composed of AP 101 and includes STA 102 to STA 103. AP 121 and STA 122 are communication devices capable of performing wireless communication compliant with the IEEE 802.11 standard series, similar to AP 101 and STA 102 to STA 103. For AP 101 and STA 102 to STA 103, Network 111 is the BSS to which their devices are connected, and hereafter this BSS will be referred to as their own BSS or simply BSS. On the other hand, for AP 101 and STA 102 to STA 103, Network 131 is a network that can interfere with their own BSS and may be called an Overlapping BSS (OBSS). Note that while Figure 1 shows networks 111 and 131 each participating in two STAs and one STA respectively, it is not limited to this configuration. That is, one or more STAs may participate in network 111, and multiple STAs may participate in network 131. Furthermore, one STA may participate in multiple networks.

[0012] In this embodiment, AP101 and STA102 to 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, targeting a maximum transmission speed of 46.08 Gbps (Gigabit per second). The main features of the IEEE 802.11bn standard are expected to include functions that realize highly reliable communication, low latency communication, and improved throughput when communication traffic is congested. The wireless frame used in a communication method compliant with this standard may be called a UHR (Ultra High Reliability) PPDU. PPDU stands for Physical Layer Protocol Data Unit. Note that names such as UHR and IEEE 802.11bn may be changed to different names once the standard is finalized. Also note that this specification and the claims attached herein are applicable to communication devices using all successor standards to IEEE 802.11be. Furthermore, communication devices may support at least one of the legacy standards prior to the IEEE 802.11bn standard. Legacy standards include, for example, the IEEE 802.11a / b / g / n / ac / ax / be standards. Communication devices may also support other communication standards such as Bluetooth®, NFC, UWB, ZigBee, and MBOA. UWB stands for Ultra Wide Band, MBOA stands for Multi Band OFDM Alliance, and NFC stands for Near Field Communication. UWB includes wireless USB, wireless 1394, WiNET, etc. 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 to STA103 are, for example, cameras, tablets, smartphones, PCs, mobile phones, video cameras, headsets, etc., but are not limited to these. STA102 to STA103 may be information processing devices such as wireless chips capable of performing wireless communication compliant with the IEEE 802.11bn standard, etc.

[0013] Communication devices can transmit and receive radio signals using frequency bands such as the 2.4 GHz band, 3.6 GHz band, 5 GHz band, and 6 GHz band, as well as millimeter wave bands such as the 45 GHz band and 60 GHz band. The frequency bands used by communication devices are not limited to these and may include, for example, the Sub1 GHz band. Furthermore, communication devices can communicate using bandwidths of 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz, 540 MHz, 640 MHz, 1080 MHz, and 2160 MHz. The bandwidths used by communication devices are not limited to these and may include, for example, bandwidths of 240 MHz or 4 MHz. Note that the IEEE 802.11 standard series specifies frequency channels using a bandwidth of 20 MHz as basic channels in frequency bands such as the 2.4 GHz, 5 GHz, and 6 GHz bands. Furthermore, this standard defines multiple available channels in the 2.4 GHz, 5 GHz, and 6 GHz 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. A bundle of channels formed by one or two or more adjacent channels may be called a communication link (link). That is, one link formed by two channels with a bandwidth of 20 MHz may use a bandwidth of 40 MHz. The IEEE 802.11be standard is expected to specify 320 MHz as the maximum bandwidth available in a single link. Signals transmitted within this bandwidth may be continuous or discontinuous on the frequency axis. AP101 and STA102 to STA103 may be AP MLDs (Multi-Link Devices) and STA MLDs, respectively, that support Multi-Link, which establishes multiple links simultaneously for communication.

[0014] When a communication device transmits a signal using a link established with another communication device, it performs carrier sensing to determine whether or not to transmit. Carrier sensing is the operation by which a communication device determines the presence or absence of a signal on the channel it intends to use for transmission. For example, a communication device measures the strength of a signal received on the channel (received signal strength) and determines that a signal is present if the received signal strength exceeds a predetermined threshold (physical carrier sensing). Received signal strength can also be called a Received Signal Strength Indicator (RSSI). Alternatively, a communication device may determine the presence or absence of a signal based on information such as the Duration field contained in the signal received on the channel (virtual carrier sensing). For example, a communication device stores the period indicated by the Duration field contained in the received signal as a Network Allocation Vector (NAV) within its own device. The communication device may treat the stored NAV as a period during which it prohibits the transmission of its own wireless frames. In this embodiment, the operation by which a communication device sets a period during which it does not transmit based on information such as the Duration field of a received signal is called setting a NAV (Network Address V). That is, the communication device determines that a signal is present on the channel until the NAV set on the channel expires. In this way, the communication device determines whether or not a signal is present on the channel based on the results of performing physical carrier sensing and virtual carrier sensing. If the communication device determines that a signal is present on the channel, it may determine that it is in a state where it cannot transmit a signal. In this case, the state of the channel may be called a busy state. On the other hand, a state in which no signal is detected on the channel in carrier sensing and a NAV is not set may be called an idle state. When the channel is in an idle state, the communication device may determine that it can transmit a signal.

[0015] A communication device, for example, when communicating using a link with a bandwidth of 160 MHz, may determine whether transmission is possible using only a first channel with a bandwidth of 20 MHz included in that link. This first channel may be called the Primary Channel (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 PCH over a predetermined period. The predetermined period is determined by the Interface 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. That is, if the communication device determines that the PCH is idle over this predetermined period, it acquires the right to transmit using that link. At this time, if a second channel other than the 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 stands for Priority IFS. Furthermore, if a communication device determines, as a result of carrier sensing on the PCH, that it cannot transmit a signal, it will postpone transmission, even if other channels on the same link are idle, by not transmitting the signal on those other channels alone. Note that each of the second channels other than the PCH that make up a link may also be called a Non-Primary Channel (NPCH) or Secondary Channel (SCH).

[0016] In communication equipment, if a signal is being received on a certain channel, and another signal is being transmitted on a channel with a frequency close to that channel (for example, an adjacent channel), the received signal may not be properly received. For example, suppose communication equipment can simultaneously perform transmission and reception using different channels. If the communication equipment is receiving on a certain channel and transmitting on an adjacent channel, the power of the transmitted signal leaks into the receiving signal channel, causing interference to the received signal. Generally, the power due to such leakage of the transmitted signal is much greater than the received power of the received signal, so it is expected that the signal will not be properly received. To avoid this situation, the IEEE 802.11 standard series provides a mechanism to prevent other communication equipment from transmitting signals to a communication equipment using a channel adjacent to the PCH while that communication equipment is transmitting a signal. In other words, a PCH is provided as a channel that communication equipment commonly uses to determine whether or not to transmit, and while one communication equipment is transmitting using the PCH, the other communication equipment is required not to transmit, even if other channels are idle. As a result, while a communication device is transmitting a signal and a PCH is in use, other communication devices will not transmit signals using channels adjacent to that PCH, thus preventing a situation where a communication device receives signals on those adjacent channels. Therefore, the interference problem caused by power leakage between channels mentioned above can be eliminated.

[0017] However, the fact that the PCH is busy, and other idle channels (NPCHs) are not used, can hinder the efficient use of the entire link's frequency resources. Figure 2A shows an example of a time chart when STA102 or STA103 transmits data to AP101. In Figure 2A, STA102 or STA103 performs carrier sensing on the PCH, confirms that it is idle, and then transmits data using the 20 MHz 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 2B shows another example of a time chart when STA102 or STA103 transmits data to AP101. In Figure 2B, while STA102 or STA103 is performing carrier sensing on the PCH, the PCH is being used by another network located geographically near STA102 or STA103 (e.g., network 131 in Figure 1). 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, for example, STA102 or STA103 is not permitted 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, it is assumed that AP101 will be able to properly receive the signal transmitted by STA102 or STA103. Thus, for example, if 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.

[0018] In contrast, the IEEE 802.11bn standard is considering the adoption of a function that allows communication between communication devices using an NPCH included in the same link as the PCH, without using the PCH itself, when the PCH is being used by another communication device. In this embodiment, such a communication method that transmits using an NPCH without using the PCH is called Non-Primary Channel Access (NPCA). 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 PCH is busy. This predetermined channel may be called an NPCA Primary Channel (NPCA PCH). An NPCA PCH is one or more channels among the NPCHs included in the same link as the PCH. 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 Secondary PCH (SPCH) or Primary Secondary Channel (PSCH). Also, NPCA PCH may be called by other names as long as they all share the common meaning of being a channel used to determine whether transmission using NPCH is possible. If the communication device determines that a PCH is being used by another communication device, it then determines whether transmission is possible on the NPCA PCH. That is, the communication device performs the carrier sense described above on the NPCA PCH and, based on confirming that the NPCA PCH is idle, determines that it can perform communication using 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.

[0019] 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 signals 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 to STA103 share information about NPCA (such as information identifying the NPCA PCH) with the receiving communication device in advance. To notify information identifying the NPCA PCH, for example, AP101 may transmit an element in the Beacon frame that includes information indicating the Operating Class of the NPCA PCH and information specifying the Channel. The Operating Class is an identifier that uniquely identifies the frequency band defined by the country or region in which AP101 is used. Furthermore, Channel is an identifier that uniquely identifies each channel included in the frequency band specified by the Operating Class. AP101 may also indicate the position of the 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 link with a bandwidth of 160 MHz in the 6 GHz band and sets 1ch in that bandwidth as the PCH (bandwidth of 20 MHz). Also, suppose that each NPCH (bandwidth of 20 MHz) is 5ch, 9ch, 13ch, 17ch, 21ch, 25ch, and 29ch, respectively. In this case, if 21ch is set as the NPCA PCH, "20" may be set as the information that identifies the NPCA PCH. In other words, the relative distance 20 on the frequency axis from channel 1, which is a PCH, to channel 21, which is an NPCA PCH, can be set as information to identify the NPCA PCH.

[0020] In NPCA, two methods are being considered for 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) Transaction (UUT). The operating mode in which both the AP STA and non-AP STA 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). Furthermore, when UUT mode is enabled, the non-AP STA will compete with other non-AP STAs for channel access using a backoff counter calculated based on the contention window (CW). It is expected that the AP STA will set different values ​​for this CW when accessing the PCH, for example, and when accessing the NPCA PCH in NPCA. However, at present, a non-AP STA has no way of knowing whether the AP STA has UUT mode enabled, or the value of the CW for NPCA determined by the AP STA, and therefore cannot perform proper channel access in UUT mode. In this embodiment, in view of these circumstances, a method is provided for providing information from AP STA to non-AP STA in order to enable non-AP STA to operate appropriately in UUT mode.

[0021] (Device Configuration) Figure 3 shows an example of the hardware configuration of the communication device (AP101 and STA102 to 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.

[0022] 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 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.

[0023] 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 storage unit 301. Alternatively, the control unit 302 may control the entire device through cooperation between the computer programs stored in the storage 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.

[0024] 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 prints, for example, image data acquired via the communication unit 306. If the communication device is a scanner, the functional unit 303 is a reading device and outputs the scanned image data 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.

[0025] The input unit 304 is configured to include, for example, a touch panel, hard keys, buttons, etc., and accepts various operations from the user. The output unit 305 is configured to include a display, 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.

[0026] 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 NFC or Bluetooth standards 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.

[0027] Antenna 307 is, for example, an antenna capable of detecting and radiating radio waves in the 2.4 GHz band, the 5 GHz band, and the 6 GHz 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 they 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, in which 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.

[0028] Figure 4 shows an example of the functional (software) configuration of the communication device (AP101 and STA102-STA103) of this embodiment. The communication device is configured to include, for example, a wireless LAN control unit 401, a frame generation unit 402, a frame analysis unit 403, a UI control unit 404, a storage control unit 405, and an NPCA control unit 406. Note that this functional configuration is just an example, and other functions may be added or the shown functions may be modified. For example, one functional block shown in Figure 4 may be divided into multiple units, or multiple functional blocks may be combined into one. Also, some functions may be omitted, or functions not shown may be added. In one example, at least some of the functions shown in Figure 4 may be realized by the control unit 302 executing a program stored in the storage unit 301. Also, at least some of the functions shown in Figure 4 may be realized using dedicated hardware.

[0029] The wireless LAN control unit 401 controls wireless LAN communication. The wireless LAN control unit 401 controls the communication unit 306 and the antenna 307 in order to send and receive wireless signals with other communication devices that are capable of wireless LAN communication. For example, the wireless LAN control unit 401 works in cooperation with the frame generation unit 402 and the frame analysis unit 403 to perform wireless frame communication control in accordance with the IEEE 802.11 series standard.

[0030] The frame generation unit 402 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 unit 402. The content of the wireless control may be constrained by the settings stored in the storage unit 301 by the storage control unit 405. The frame generation unit 402 can also accept settings from the user via the UI control unit 404. The wireless frames generated by the frame generation unit 402 are supplied to the wireless LAN control unit 401 and can be transmitted externally using the communication unit 306 and antenna 307 under the control of the wireless LAN control unit 401. The frame analysis unit 403 analyzes the wireless frames received via the communication unit 306 and antenna 307 under the control of the wireless LAN control unit 401. When analyzing wireless frames, the frame analysis unit 403 can determine the analysis method based on settings stored in the storage unit 301 by the storage control unit 405.

[0031] The UI control unit 404 controls the input unit 304 to accept input to a user interface (UI), such as a touch panel or buttons, for receiving operations on the communication device by a user (not shown). The UI control unit 404 can also control the output unit 305, for example, to perform controls to present information to the user, such as displaying images or outputting sound. The UI control unit 404 can also control the input unit 304 and the output unit 305 to display a graphical UI (GUI) on the display and accept operations on that GUI. The storage control unit 405 controls the storage unit 301 to perform various information storage controls, such as saving, searching, and extracting programs and data on which the communication device operates. The NPCA control unit 406 performs control processing for the communication device to perform channel access by NPCA.

[0032] (Channel Access via UUT Mode) Next, an example of the channel access procedure when UUT mode is used will be explained using Figure 5. In this example, AP101 and STA102 to STA103 are assumed to be configured to operate in NPCA's UUT mode.

[0033] In this example, at timing 501, the OBSS communication device (AP121 or STA122) acquires the right to transmit on the PCH. Meanwhile, STA102 sets a transmission waiting time 502 while the PCH is idle in order to transmit data at a timing prior to timing 501, and attempts to access the channel on the PCH. Based on the backoff algorithm, STA102 determines the waiting time 502, which includes Arbitration Inter-Frame Spacing (AIFS) and a backoff counter. Then, STA102 decreases the waiting time 502 while the PCH is idle, and can start transmitting a frame when the waiting time becomes zero. Similarly, STA103 sets a waiting time 503 and attempts to access the channel on the PCH. However, as described above, in this example, at timing 501, the PCH becomes busy because the OBSS communication device acquired the right to transmit on the PCH first.

[0034] In this case, AP101 and STA102-STA103 set NAV during the Transmission Opportunity (TXOP) in OBSS, and refrain from transmitting wireless frames on the PCH during the NAV period. AP101 and STA102-STA103 also switch the channel to be monitored for channel access to the NPCA PCH and attempt to acquire a transmission opportunity on the NPCH. At this time, AP101 and STA102-STA103 in this embodiment may attempt channel access on the NPCA PCH using backoff parameters different from those used on the PCH. STA102 and STA103 also use the backoff algorithm to set waiting times 504 and 505, respectively, when accessing the NPCA PCH. Then, in Figure 5, STA102 acquires the right to transmit after the waiting time 504 for STA102 has elapsed while the NPCA PCH remains idle, and sends frame 506 to AP101. During this time, STA103 sets NAV 507 to prevent the NPCA PCH from transmitting wireless frames. Subsequently, AP101 and STA102-STA103 return the channel to be monitored for channel access back to the PCH at timing 508, in response to the expiration of the NAV period. Then, for example, STA103 sets a waiting time 509 in the PCH using a backoff algorithm, and sends a wireless frame to AP101 as the waiting time elapses.

[0035] Using Figure 6, an example of the channel access function in AP101 and STA102-STA103 will be explained. The channel access function includes a data categorization unit 601, a queue 602, and a channel access control unit 605. The channel access control unit 605 also includes a CSMA / CA execution unit 603 and a backoff / collision control unit 604.

[0036] The data categorization unit 601 classifies the 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 601 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 601 stores the data (MAC frame) classified into one of the ACs in the queue 602 corresponding to that AC. The queue 602, also called a traffic buffer, is provided for each AC.

[0037] The channel access control unit 605 performs channel access control based on CSMA / CA for data held in the queue corresponding to each AC in the CSMA / CA execution unit 603. CSMA / CA is an abbreviation for Carrier Sense Multiple Access with Collision Avoidance. When the CSMA / CA execution unit 603 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 604. Then, the CSMA / CA execution unit 603 determines the transmission waiting time, consisting of the AIFS and the backoff counter, based on the read EDCA parameters. Hereafter, the transmission waiting time, including the AIFS and the backoff counter, will also be simply referred to as the backoff parameters. EDCA parameters can be set so that radio signal transmission is relatively prioritized in the order of VO, VI, VE, BK. Each EDCA parameter includes CWmin, CWmax, AIFS, and TXOPLimit. CWmin is the minimum CW time, which is the waiting time for transmission, and CWmax is the maximum CW time. The shorter CWmin and CWmax, the easier it is to get a transmission opportunity. AIFS is the transmission interval for radio signals. The smaller AIFS, the easier it is to get a transmission opportunity. TXOPLimit is the upper limit of TXOP, which is the channel occupancy time. The larger TXOPLimit, the more data can be transmitted in a single transmission opportunity.

[0038] The backoff / collision control unit 604 monitors the channel status and notifies the CSMA / CA execution unit 603 of the channel status information obtained through monitoring. The CSMA / CA execution unit 603 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 603 stops the decrementing of the backoff parameter while the notified channel status is busy. The CSMA / CA execution unit 603 then determines that it has acquired an opportunity to transmit when the waiting time becomes zero. The CSMA / CA execution unit 603 retrieves data (MAC frame) from the queue and, in cooperation with the backoff / collision control unit 604, the communication unit 306, and the antenna 307, transmits the UHR PPDU containing the MAC frame to other communication devices. When the communication device obtains a transmission opportunity in the PCH, it transmits a UHR PPDU on one or more channels including the PCH, and when it obtains a transmission opportunity in the NPCA PCH, it transmits a UHR PPDU on one or more channels including the NPCA PCH.

[0039] The backoff / collision control unit 604 also mediates when there is an internal conflict in the acquisition of transmission opportunities by the CSMA / CA execution units 603 corresponding to each AC. That is, when CSMA / CA execution units 603 corresponding to different ACs acquire transmission opportunities simultaneously and request data transmission, the backoff / collision control unit 604 controls the system so that data stored in the higher priority queue is transmitted preferentially. For example, when a CSMA / CA execution unit 603 corresponding to the VO queue and a CSMA / CA execution unit 603 corresponding to the BK queue acquire transmission opportunities simultaneously, the backoff / collision control unit 604 controls the system so that data stored in the VO queue is transmitted preferentially. At this time, the backoff / collision control unit 604 notifies the CSMA / CA execution unit 604 corresponding to the BK queue that a collision has occurred and increases the CW managed by the CSMA / CA execution unit 604 corresponding to the BK queue.

[0040] The backoff / collision control unit 604 performs control such as notifying the CSMA / CA execution unit 603 of changes in channel status, sending transition notifications indicating that the channel attempting channel access has transitioned to the NPCA PCH, and sending re-transition notifications indicating that it has transitioned back to the PCH. When the CSMA / CA execution unit 603 receives a transition notification or re-transition notification, it updates the backoff parameters as necessary.

[0041] (Processing Flow) Figure 7 schematically shows the communication processing flow according to this embodiment. First, when AP101 connects to STA102 and STA103, it notifies STA102 and STA103 of various setting information (S701). The notified setting information includes, for example, EDCA parameters for communication on the PCH, whether or not UUT mode is enabled, and NPCA_CW used in UUT mode. The setting information may also include UHR parameter set, UHR Capabilities, and UHR Operation.

[0042] Here, Figure 8 shows an example of the general flow of the connection process between AP101 and STA102 or STA103. AP periodically sends Beacon frames (S801). STA also sends Probe Request frames (S802), and AP sends a Probe Response frame in response to receiving the Probe Request frame (S803). Subsequently, STA sends an Association Request frame to AP (S804), and AP sends an Association Response frame to STA (S805). This establishes a connection between AP and STA, and data communication takes place between AP and STA (S806). Here, the AP can notify the STA of the above-mentioned configuration information in Beacon frames, Probe Response frames, and Association Response frames. In other words, the above-mentioned configuration information is transmitted in management frames.

[0043] Figure 9 shows an example of the format for a portion of a Probe Response frame. As shown in Figure 9, a 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 settings. Also, a Beacon frame may contain information as shown in Figure 9. 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 in which the Beacon frame is sent. The Capability Information element stores information about the network's or the AP's ability to send this frame. The SSID element stores the Service Set Identifier. The Supported Rates and BSSMembership Selectors element stores information such as supported communication rates. The DSSS Parameter Set element stores parameters related to Direct Sequence Spread Spectrum (DSSS). The IBSS Parameter Set element stores parameters related to Independent BSS (IBSS). The Country element stores regional information, and the Power Constraint element stores information about limitations on maximum transmit power. The Channel Switch Announcement element is used to announce changes when the BSS changes to a new channel or to a new channel in a new operating class. The Quiet element stores information about periods when no frames are transmitted in the BSS. The IBSS DFS element stores information for Dynamic Frequency Selection (DFS) in the IBSS. The TPC Report element stores information such as the transmit power when transmitting 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 display communication rates that are not indicated 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 on the BSS (such as the current number of STAs and traffic levels). The EDCA Parameter Set element stores the information necessary for STA to perform EDCA access.

[0044] The HE Capabilities element stores information regarding the capabilities of the network or the AP transmitting this frame with respect to IEEE 802.11ax (High Efficiency (HE)). The HE Operation element stores information used to control the operations related to IEEE 802.11ax (HE). The MU EDCA Parameter Set element stores information about the parameters for Multi-User (MU) EDCA. MU EDCA is a mechanism for making it difficult for a STA that has been granted a Resource Unit (RU) for UL communication in MU UL communication to access the channel by EDCA for a certain period of time. The Multi-Link element stores information regarding multi-link communication. The EHT Capabilities element stores information regarding the capabilities of the network or the AP transmitting this frame with respect to IEEE 802.11be (Extremely High Throughput (EHT)). The EHT Operation element stores information used to control the operations related to IEEE 802.11be (EHT). The TID-To-Link element stores information indicating the association between the Traffic ID (TID) and the link. The UHR Capabilities element stores information regarding the capabilities of the network or the AP transmitting this frame with respect to IEEE 802.11bn (UHR). The UHR Operation element stores information used to control the operations related to IEEE 802.11bn (UHR). The NPCA EDCA Parameter Set element stores information about the parameters for EDCA in NPCA.

[0045] Furthermore, an Association Response frame has a configuration similar to that shown in Figure 10. An Association Response frame may also contain information elements similar to those of a Probe Response frame. For example, the Status Code field stores information such as whether the Association was successful or rejected. The AID field stores information about the Association Identifier (AID) to be assigned to the recipient of this frame. The other fields are similar to those related to a Probe Response frame.

[0046] 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, it includes EDCA parameters used in the UUT mode of NPCA (NPCA EDCA Parameter Set) separately from the conventional EDCA parameters. The NPCA EDCA Parameter Set element is placed, for example, after the UHR Capabilities element and the UHR Operation element.

[0047] Figure 11 shows an example of the configuration of a UHR Operation element. The UHR Operation element is identified as such by, for example, Element ID and Element ID Extension. Length indicates the size of the element. UHR Operation Parameters include NPCA Operation Information Present. NPCA Operation Information Present may be a single bit indicating whether or not operational parameters for NPCA are provided. If NPCA Operation Information Present indicates that operational parameters for NPCA are provided, it implicitly indicates that operation with NPCA is enabled. NPCA Operation Information Present is set to "1" if, for example, operational parameters for NPCA are provided, and to "0" if they are not provided. When NPCA Operation Information Present is set to "1", operational parameters for NPCA are provided in the UHR Operation Information described below. On the other hand, when NPCA Operation Information Present is set to "0", operational parameters for NPCA are not provided in the UHR Operation Information described below. Operational parameters for NPCA may be the "NPCA Operation Information" described below. The Basic UHR MCS And Nss Set stores information such as the maximum number of spatial streams for transmission and reception for the UHR's MCS value. The UHR Operation Information includes NPCA Operation Information and other information (Other Operation Information). Note that if NPCA Operation Information Present is set to "0", NPCA Operation Information will not be included.

[0048] In NPCA Operation Information, NPCA Primary Channel 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 Threhold 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 it is assumed that the OBSS is communicating on the PCH (for example, when NAV is set by OBSS communication) is sufficiently long. STA will not perform NPCA if the remaining time for the BSS's PCH to be occupied by the OBSS does not exceed the minimum duration, and will wait until the PCH becomes idle. NPCA Switching Delay indicates the time considered as the delay required for configuration changes when switching to the state in which NPCA is performed. NPCA Switch Back Delay indicates the time considered as the delay required for configuration changes when switching back from the state in which NPCA is performed to the state in which communication using the BSS's PCH is performed without NPCA. UUT Mode stores information indicating whether the UUT mode is enabled or disabled. Note that the UUT mode may be enabled or disabled for each AC, and in one example, UUT Mode may store information indicating whether the UUT mode is enabled or disabled for each AC. In this case, UUT Mode is composed of, for example, 4 bits. On the other hand, the UUT mode may be set uniformly for all ACs, in which case the UUT Mode may consist of 1 bit.In this case, for example, if any information is reduced by 1 bit, such as the NPCA Minimum Duration Threshold being reduced to 3 bits, the NPCA Operation Information can be configured with 3 octets.

[0049] Fig. 12 shows the configuration of the EDCA Parameter Set element. The EDCA Parameter Set element includes an Element ID and an Element ID Extension indicating that this element is an EDCA Parameter Set element. The EDCA Parameter Set element also includes a Length indicating the length of the element, a QoS Info storing a counter value indicating whether the parameter has been updated. The EDCA Parameter Set element further includes parameters (Parameter Record) for each AC (AC_BE, AC_BK, AC_VI, and AC_VO). The Parameter Record for each AC includes ACI / AIFSN, ECWmin / ECWmax, and TXOP Limit. ACI / AIFSN includes AIFSN, ACM, and ACI. The ACI stores the value of the AC Index (ACI). That is, "0" indicating AC_BE is stored in the ACI of the AC_BE Parameter Record. Similarly, "1", "2", and "3" are stored as the ACI values for AC_BK, AC_VI, and AC_VO, respectively. ACM (Admission Control Mandatory) stores "1" when admission control is required for that AC and "0" when it is not. The AIFSN stores a numerical value used to determine the AIFS, which is the transmission interval of the wireless signal. ECWmin and ECWmax are information obtained by encoding CWmin and CWmax that specify the maximum and minimum values of CW. CWmin = 2ECWmin - 1 and CWmax = 2ECWmax - 1.

[0050] Figure 13 shows the configuration of the MU EDCA Parameter Set element. In the MU EDCA Parameter Set element, the Element ID and Element ID Extension indicate that this element is a MU EDCA Parameter Set element. In addition, the MU EDCA Parameter Set element includes Length and QoS Info, similar to the EDCA Parameter Set element. The MU EDCA Parameter Set element includes a Parameter Record for the MU for each AC. This Parameter Record does not include a TXOP Limit, but instead includes a MU EDCA Timer. The MU EDCA Timer indicates the period in 8 Time Units (TUs) during which an STA uses the MU EDCA parameters for its corresponding AC. An STA to which a RU has been allocated for MU UL transmission will have its probability of acquiring transmission rights through EDCA channel access suppressed for the indicated length period after that MU UL transmission.

[0051] Figure 14 shows the configuration of an NPCA EDCA Parameter Set element. In an NPCA EDCA Parameter Set element, the Element ID and Element ID Extension indicate that this element is an NPCA EDCA Parameter Set element. In addition, like an EDCA Parameter Set element, an NPCA EDCA Parameter Set element includes Length and QoS Info. An NPCA EDCA Parameter Set element includes an NPCA Parameter Record for each AC. This Parameter Record includes, for example, only ECWmin / ECWmax, and does not include ACI / AIFSN, TXOP Limit, or MU EDCA Timer. This allows the Parameter Record to be represented in one octet.

[0052] Each of the above parameters can be set, for example, by accepting user input on a Graphical User Interface (GUI) screen, as shown in Figure 15. For example, the GUI screen has areas for accepting input of EDCA parameters and MU EDCA parameters. The EDCA parameter input area 1501 is configured to allow input of CWmin, CWmax, AIFSN, and TXOP values ​​for each AC. For example, the CWmin, CWmax, AIFSN, and TXOP values ​​for AC_BK are stored in the AIFSN, ECWmin, ECWmax, and TXOP Limit fields of the AC_BK Parameter Record shown in Figure 12. Similarly, the CWmin, CWmax, AIFSN, and TXOP values ​​of AC_BE are stored in the AIFSN, ECWmin, ECWmax, and TXOP Limit fields of the AC_BE Parameter Record shown in Figure 12. The same applies to AC_VI and AC_VO. Furthermore, the input area 1502 for the MU EDCA parameters is configured to accept input values ​​for CWmin, CWmax, AIFSN, and MU EDCA Timer for each AC. For example, the CWmin, CWmax, AIFSN, and MU EDCA Timer values ​​of AC_BK are stored as the respective values ​​of the MU AC_BK Parameter Record shown in Figure 13. The same applies to AC_BE, AC_VI, and AC_VO.

[0053] The GUI screen further includes a setting area 1503 for accepting whether or not to enable UUT mode. The setting value in setting area 1503 is stored in UUT Mode in Figure 11. Note that setting area 1503 may be configured to accept the setting of whether or not to enable UUT mode for each AC. For example, when UUT mode is enabled, area 1504 for setting CWmin and CWmax for NPCA may be displayed. Note that when UUT mode is not enabled, area 1504 does not have to be displayed, or the input field for the value may be grayed out and disabled. In one example, if enabling or disabling UUT mode is accepted for each AC, the input field for the setting value for the AC in which UUT mode is enabled may be enabled, and the input fields for other ACs may be grayed out. The values ​​entered for CWmin and CWmax of AC_BK are stored as the respective values ​​in NPCA AC_BK Parameter Record shown in Figure 14. The same applies to AC_BE, AC_VI, and AC_VO.

[0054] The settings entered by the user are activated when the settings button 1505 is pressed.

[0055] Returning to Figure 7, we will now explain the processing according to the UUT mode. First, we will explain the case when the UUT mode is disabled. First, assume that data to be transmitted is generated in AP121 or STA122 and the transmission right (TXOP) is acquired (S711). Then, AP101 and STA102-STA103 start communication processing using NPCA (S712). In this case, since the UUT mode is disabled, STA102-STA103 are not allowed to access the NPCH using EDCA. Therefore, for example, when STA102-STA103 transmit data to AP101, the data is transmitted based on a trigger frame from AP101. In this way, AP101 and STA102-STA103 perform data communication (S713). Subsequently, AP101 and STA102-STA103 terminate NPCA upon the expiration of the NAV period in the PCH (termination of TXOP in the OBSS (S714)) and transition to a state in which they perform communication processing in the BSS's PCH (S715).

[0056] Here, the details of the communication processing flow when UUT mode is disabled will be explained using the example in Figure 16. First, assume that data to be transmitted is generated in AP121 or STA122, and the transmission right (TXOP) is acquired by the backoff algorithm (S1601). In this case, AP101 and STA102-STA103 determine whether or not to perform NPCA communication in response to the OBSS's determination that it has acquired TXOP (S1602). AP101 and STA102-STA103 determine to perform NPCA communication, for example, if the NAV period set in the PCH exceeds the value stored in NPCA Minimum Duration Threhold in Figure 11. AP101 and STA102-STA103 can each perform this determination. AP101 and STA102-STA103 change their settings to enable NPCA communication when they determine that they should communicate via NPCA (S1603). AP101 and STA102-STA103 switch the monitored channel to the NPCA PCH as a result of this setting change. AP101 then sends, for example, an Initial Control Frame (ICF) (S1604) to query the NPCA PCH to see if there are any STAs that have transitioned to the state of communicating via NPCA. If STA102-STA103 have transitioned to the state of communicating via NPCA, they send an Initial Control Response frame as a response frame to this ICF (S1605). Furthermore, an ICF may be a frame in which the value of the GI And HE / EHT / UHR-LTF Type subfield in the Common Info field of a Buffer Status Report Poll trigger frame is set to 3. Also, an ICR may be a Multi-STA Block Ack (M-BA) frame in which the values ​​of the Ack Type subfield and TID subfield in the Per AID TID Info field are set to predetermined values. In one example, an ICR may also transmit the Buffer Status Report of the STA that is the source of the ICR.Alternatively, AP101 may send a separate Buffer Status Report Poll trigger frame to cause each STA to send a Buffer Status Report.

[0057] Subsequently, AP101 may transmit a Downlink Multi-User PPDU (DL MU PPDU) to the STA that transmits the ICR by allocating a Resource Unit (RU) or a spatial stream (S1606). AP101 may transmit a DL MU PPDU, for example, using a backoff algorithm, in response to the NPCA PCH remaining idle for a predetermined period of time. STA102 to STA103 may transmit a Block Ack (BA) to AP101 indicating the reception result of the PPDU (S1607). Furthermore, if AP101 recognizes from the Buffer Status Report that each STA is holding the data to be transmitted in its buffer, it transmits a trigger frame for Uplink (UL) data transmission (S1608). This trigger frame is a Basic Trigger Frame and includes the allocation of RUs, etc., to cause STA to send a data frame. STA102 to STA103 send UL data in response to this trigger frame (S1609). When AP101 receives the UL data, it sends a Multi-STA Block Ack (BA) to STA102 to STA103, which sent the UL data (not shown). Then, after the completion of the OBSS TXOP (after the expiration of the period in which NAV is set in AP101 and STA102 to STA103) (S1610), AP101 and STA102 to STA103 terminate the NPCA processing. That is, AP101 and STA102 to STA103 perform state transition processing to return the monitored channel to the BSS PCH (S1611). In this way, when UUT mode is disabled, AP101 and STA102 to STA103 can perform data communication using NPCA. Note that Figure 16 shows an example in which both DL and UL communication are performed during the OBSS TXOP period, but it is not limited to this. That is, depending on the length of the TXOP, only either DL data transmission or UL data transmission may be performed using NPCA.

[0058] Returning to Figure 7, we will now explain the case where UUT mode is enabled. First, assume that data to be transmitted is generated in AP121 or STA122, and a TXOP is obtained by the backoff algorithm (S721). AP101 and STA102-STA103 begin communication processing using NPCA (S722). In this case, since UUT mode is enabled, STA102-STA103 are allowed to access the NPCH using EDCA. Therefore, for example, when STA102-STA103 transmit data to AP101, they can voluntarily transmit the data using the backoff algorithm. In this way, AP101 and STA102-STA103 perform data communication (S723). Subsequently, AP101 and STA102-STA103 terminate NPCA upon the expiration of the NAV period in the PCH (termination of TXOP in the OBSS (S724)) and transition to a state in which they perform communication processing in the BSS's PCH (S725).

[0059] Here, we will explain the details of the communication processing flow when UUT mode is enabled, using the example in Figure 17. First, let's assume that data to be transmitted is generated in AP121 or STA122, and the transmission right (TXOP) is acquired by the backoff algorithm (S1701). In this case, AP101 and STA102-STA103 determine whether or not to perform NPCA communication in response to the OBSS's determination that it has acquired TXOP (S1702). This determination is the same as S1602 in Figure 16. AP101 and STA102-STA103 change their settings to perform NPCA communication in response to the determination that they will perform NPCA communication (S1703). AP101 and STA102-STA103 switch the monitored channel to the NPCA PCH as a result of this setting change. Then, for example, STA102 attempts to transmit the data based on the fact that it has data to be transmitted. For example, STA102 uses a backoff algorithm to confirm that the NPCA PCH is idle, then transmits an ICF (S1704) and receives an ICR from AP101 (S1705). Alternatively, a Request-To-Send (RTS) frame may be transmitted instead of an ICF, and a Clear-To-Send (CTS) frame may be received instead of an ICR. Then, STA102 transmits a PPDU to AP101 (S1706) and receives an ACK from AP101 (S1707). AP101 may also transmit a DL data signal to AP102 or AP103 as needed. Subsequently, for example, AP101 and STA102-STA103 may return the monitored channel to the BSS PCH if the conditions for communication via NPCA are no longer met (S1708). Note that this state change may be performed without waiting for the OBSS TXOP to finish (S1709).

[0060] Next, using Figures 18A and 18B, examples of the processing flow performed by AP101 and STA102 to STA103 will be explained. Each process in Figure 18A is executed by the processor of the control unit 302 of AP101 executing a computer program stored in the storage unit 301. Similarly, each process in Figure 18B is executed by the processor of the control unit 302 of STA102 to STA103 executing a computer program stored in the storage unit 301. In any case of communication device, 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 the ASIC or processor inside the communication unit 306 with the antenna.

[0061] As shown in Figure 18A, AP101 periodically transmits a Beacon frame containing an NPDA EDCA Parameter Set element that includes parameters used for channel access in NPCA (S1801). The Beacon frame further includes an EDCA Parameter Set element and a MU EDCA Parameter Set element, which are parameters used for channel access in PCH. That is, in addition to the first EDCA parameters used for channel access in normal PCH, the Beacon frame transmits a second EDCA parameter used for channel access in NPCA PCH. The Beacon frame further includes a UHR Capabilities element and a UHR Operation element. The NPCA EDCA Parameter Set element 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 retrieve the parameters included in the NPCA EDCA Parameter Set element. AP101 may also transmit a Probe Response frame containing the above elements when it receives a Probe Request frame from the STA. AP101 may also transmit an Association Response frame containing the above elements when it receives an Association Request frame from the STA. AP101 may transmit the above elements in one of the Beacon frame, Probe Response frame, or Association Response frame, or it may transmit the above elements in two or more of them. In other words, each element may be transmitted to STA in only one type of frame, or each element may be repeatedly transmitted to STA in multiple types of frames.Furthermore, when AP101 receives a Response frame, it may send a Response frame containing the elements described above.

[0062] STA102 to STA103 receive Beacon frames, Probe Response frames, and Association Response frames transmitted from AP101. Then, as shown in Figure 18B, STA102 to STA103 identify and store the NPCA PCH from at least one of these frames (S1811). For example, STA102 to STA103 check the NPCA Operation Information contained in the UHR Operation element in Figure 11 and identify the NPCA PCH. STA102 to STA103 also extract parameters related to EDCA from at least one of these frames, store those parameters, or update the stored parameters (S1811). STA102 to STA103 check the NPCA EDCA Parameter Set element and store or update the NPCA EDCA parameters for accessing the NPCA PCH. STA102 to STA103 also check the EDCA Parameter Set element and store or update the EDCA parameters for accessing the BSS PCH. Furthermore, STA102 to STA103 check the MU EDCA Parameter Set element and store or update the EDCA parameters to be used for MU UL communication to which the RU is assigned.

[0063] Figures 19A and 19B show an example of the processing flow when STA102 to STA103 transmit data (PPDU). Each process in Figures 19A and 19B is executed by the processor of the control unit 302 of STA102 to STA103 executing a computer program stored in the storage 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".

[0064] 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 (S1901). For example, when a video distribution application starts video distribution, the data corresponding to the video data obtained from the camera equipped in the STA is classified as VI by the data categorization unit 601 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 601 and stored in the VO queue. Note that the determination process in S1901 may be executed in parallel by multiple CSMA / CA execution units 603 corresponding to each queue.

[0065] If STA confirms that the transmitted data has been stored (YES in S1901), STA obtains the EDCA parameters corresponding to the AC of the associated queue. Based on the obtained EDCA parameters, STA determines a backoff parameter consisting of the AIFS and the backoff value indicated by the backoff counter, and sets the determined backoff parameter (S1902). 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. In other words, in environments where collisions occur frequently, the range of candidates for random backoff increases, suppressing the occurrence of collisions. STA calculates the backoff counter to be used by generating aCWmin, which corresponds to the access category, a set of EDCA parameters, and a random number that follows a uniform distribution within the current contention window size (CWsize).

[0066] After setting the backoff parameter, 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 PCH channel state is idle (S1903). The STA first performs a wait process for the transmission waiting time equivalent to AIFS, and when the transmission waiting time equivalent to AIFS becomes zero, it performs a decrement process for the backoff counter. Before the backoff counter becomes zero (NO in S1904), the STA monitors whether another STA (AP STA or non-AP STA) has acquired a transmission opportunity (S1905). That is, the STA performs carrier sensing on the PCH. If the PCH has not changed from idle to busy, the STA determines that no other STA has acquired a transmission opportunity (NO in S1905) and returns to processing S1903. If, based on the results of this analysis, the STA determines that the radio frame is destined for its own device, it performs processing such as demodulation of the radio frame (not shown). If an STA determines that the backoff counter has reached zero without any other STAs having had a transmission opportunity (NO in S1905, YES in S1904), it transmits the data stored in the corresponding AC queue on the PCH (S1908). The STA transmits UHR PPDU format data on at least one channel, including the PCH. When transmitting data, the STA determines whether the transmitted data has collided with data transmitted by another STA (S1909). If the STA determines that a data collision has occurred (YES in S1909), it expands the CWsize (S1910). 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 S1909), it determines that the data transmission was successful and initializes the CWsize to aCWmin (S1911). Then, after updating or initializing CWsize, STA determines whether or not to turn off the power (to terminate communication) (S1912). For example, if STA receives a user command to turn off the power, it may determine to turn off the power.If STA determines that the power should be turned off (YES in S1912), it performs a shutdown process (not shown) and terminates the series of transmission controls. On the other hand, if STA determines that the power should not be turned off (communication should not be terminated) (NO in S1912), it returns to process S1901.

[0067] On the other hand, if STA determines that another STA has acquired an opportunity to transmit a radio frame not addressed to its own device before the backoff counter reaches zero (NO in S1904) (YES in S1905), it sets the NAV (PCH_NAV) in the PCH (S1906). STA sets the length of the NAV based on information such as the Duration field of the PPDU from the other STA. STA also discards the current PCH backoff parameter. Finally, STA executes transmission control in the NPCA PCH (S1907).

[0068] Next, the transmission control in S1907 will be explained using Figure 20. First, STA sets the backoff parameter for channel access in the NPCA PCH (S2001). STA identifies the value of AIFSN in either the Basic EDCA parameter set or the MU EDCA parameter set stored in S1811. For example, if the MU EDCA timer has started but has not yet expired, STA uses the value of AIFSN in the MU EDCA parameter set as the AIFSN in the NPCA EDCA parameter set. Also, for example, if the MU EDCA timer has not started or has already expired, STA uses the value of AIFSN in the Basic EDCA parameter set as the AIFSN in the NPCA EDCA parameter set. Then, STA sets the backoff parameters corresponding to each AC using its AIFSN and the CW parameters (ECWmin and ECWmax) of the NPCA EDCA parameter set. That is, multiple CSMA / CA execution units 603 corresponding to each AC of STA can each identify the backoff parameters using the AIFSN and CW parameters for the corresponding AC. Note that only the CSMA / CA execution unit 603 for ACs with data pending in the queue will identify these backoff parameters, while the CSMA / CA execution units 603 for other ACs do not need to identify the backoff parameters.

[0069] 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 (S2002). Before the backoff counter becomes zero (NO in S2003), the STA monitors whether another STA (AP STA or non-AP STA) has acquired a transmission opportunity (S2004). That is, the STA performs carrier sensing on the NPCA PCH. If the PCH has not changed from idle to busy, the STA determines that no other STA has acquired a transmission opportunity (NO in S2004) and returns to processing S2002. If the STA determines that the backoff counter has become zero without any other STA acquiring a transmission opportunity (NO in S2004, YES in S2003), the STA transmits the data stored in the queue of the corresponding AC on the NPCA PCH (S2006). STA transmits data in UHR PPDU format on one or more NPCHs that include at least an NPCA PCH (but do not include a PCH). When transmitting data, STA determines whether the transmitted data has collided with data transmitted by another STA (S2007). If STA determines that a data collision has occurred (YES in S2007), it expands CWsize (S2008). Specifically, STA changes CWsize to twice its current size. On the other hand, if STA determines that no data collision has occurred (NO in S2007), it determines that the data transmission was successful and initializes CWsize to aCWmin (S2009). Then, after updating or initializing CWsize, STA determines whether to continue transmission control on the NPCA PCH (S2010). For example, if STA determines that the period set in S1906 for PCH_NAV has ended, it decides not to continue transmission control on the NPCA PCH. Then, STA changes the settings to enable communication control on the PCH. Based on the Basic EDCA parameter set, STA controls the setting of backoff parameters, including AIFS and the backoff counter (S2011), and returns the process to S1903.Furthermore, if STA does not have any transmission data, it may proceed to S1912 without performing backoff parameter setting control. The processing in S2010 and S2011 can also be described as control to terminate the control that attempts to acquire a transmission opportunity in NPCH before the NAV period set in PCH has elapsed.

[0070] On the other hand, if STA determines that another STA has acquired an opportunity to transmit a wireless frame not addressed to its own device before the backoff counter becomes zero (NO in S2003) (YES in S2004), STA sets the NAV in the NPCA PCH (S2005). Based on information such as the Duration field of the PPDU from the other STA, STA sets the length of the NAV in this NPCA PCH. Then, STA moves the process to S2010.

[0071] (Modification) In the above example, an example was described in which the UHR Operation element indicates whether the UUT mode is enabled or disabled, but it is not limited to this. For example, as shown in Figure 21A, the NPCA EDCA Parameter Set element may store information indicating whether the UUT mode is enabled or disabled. Alternatively, for example, the Parameter Record for each AC in the NPCA EDCA Parameter Set element may be composed of two octets, and information specifying whether the UUT mode is enabled or disabled may be stored therein. For example, as shown in Figure 21B, one octet may be added to the Parameter Record, and if the value of that one octet is a predetermined value such as "0", the UUT mode for the corresponding AC may be disabled, and if it is any other value, the UUT mode may be enabled. In one example, the enable / disable status of UUT mode may be indicated using one bit designated as Reserved for ACI / AIFSN in the Parameter Record of the NPCA EDCA Parameter Set element. In this case, if UUT mode is disabled, ECWmin / ECWmax in the Parameter Record may be omitted. Alternatively, the enable / disable status of UUT mode may be indicated using one bit designated as Reserved for ACI / AIFSN in the EDCA Parameter Set element or the MU EDCA Parameter Set element. Furthermore, the presence of the NPCA EDCA Parameter Set element may implicitly indicate that UUT mode is enabled. In this case, the absence of the NPCA EDCA Parameter Set element implicitly indicates that the UUT mode is disabled. Alternatively, the enablement or disablement of the UUT mode may be indicated by other values. For example, if the value of AIFSN in the MU EDCA Parameter Set element is set to a special value, the UUT mode may be enabled or disabled for the AC corresponding to that AIFSN.For example, the UUT mode may be disabled for ACs where the AIFSN in the MU EDCA Parameter Set element is set to "0", and enabled for ACs where it is set to other values. For example, in the example in Figure 15, the AIFSN for AC_BK is set to "0", and the AIFSN for the other ACs is set to something other than "0". Therefore, the UUT mode may be disabled for AC_BK, and enabled for AC_BE, AC_VI, and AC_VO. Thus, information indicating whether the UUT mode is enabled or disabled can be expressed in various formats. Even if the UUT mode is disabled, parameters (ECWmin and ECWmax) for EDCA access to the NPCA PCH may be stored in the management frame and transmitted.

[0072] Furthermore, while the above example described an example where the EDCA Parameter Set element stores the information necessary for STA to perform EDCA access via BSS PCH, this is not the only example. The information may also be stored in another element that is an extension based on the EDCA Parameter Set element. For example, a modification may be made to include a set of EDCA parameters for performing EDCA access via BSS PCH in the WMM Parameter element. WMM stands for Wi-Fi® MultiMedia. This element has "221" set as Element ID, "00:50:f2" set as OUI, "2" set as OUI Type, and "1" set as OUI Subtype. The QoS Info field includes the U-APSD field, which transmits information about power saving, and the Parameter Set Count field, which indicates the parameter update status. U-APSD stands for Unscheduled Automatic Power Save Delivery. Furthermore, the element includes fields corresponding to the EDCA parameter sets exemplified in Figure 12. For example, the AC Parameters Best_Effort field included in this element corresponds to the AC_BE Parameter Record field in Figure 12. The AC Parameters Background field included in this element corresponds to the AC_BK Parameter Record field in Figure 12. The AC Parameters Video field contained in this element corresponds to the AC_VI Parameter Record field in Figure 12. The AC Parameters Voice field contained in this element corresponds to the AC_VO Parameter Record field in Figure 12.

[0073] As described above, the STA in this embodiment can determine whether UUT mode is enabled in BSS and the parameters for operation in UUT mode via the Management frame transmitted from the AP. This allows the AP to flexibly configure whether or not to allow the STA to perform channel access using EDCA in NPCA. Furthermore, the AP can cause the STA to perform channel access using EDCA with different parameters than those used for PCH.

[0074] Furthermore, the terminology used in the above description may include temporary terms used to describe technical features currently under consideration. Therefore, it is naturally intended that these terms may be replaced with other terms of similar meaning, and such technical features, when replaced with other terms, will naturally constitute part of this embodiment. Additionally, the above features can be used in any combination, provided they do not contradict each other.

[0075] 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., ASIC) that implements one or more functions.

[0076] The technical ideas derived from this disclosure are not limited to the exemplary embodiments disclosed, but are intended to encompass various modifications of the exemplary embodiments, or substitutions with equivalent structures or functions. The scope of the following claims should be interpreted in the broadest way to encompass all such modifications and equivalent structures and functions.

[0077] This application claims priority based on Japanese Patent Application No. 2025-025229, filed on 19 February 2025, and all of its contents are incorporated herein by reference.

Claims

1. A communication device that functions as an access point compliant with the IEEE 802.11 standard, comprising a communication link comprising a first channel used to acquire transmission rights and one or more second channels different from the first channel, wherein the communication means communicates using either a first communication method that uses at least the first channel, or a second communication method that acquires transmission rights using a predetermined channel from the one or more second channels without using the first channel during periods when the first channel cannot be used, wherein the communication means communicates to other communication devices operating as stations, comprising an Ultra High Reliability (UHR) Capabilities element and an Enhanced Distributed Channel in the second communication method, which is located after the UHR Capabilities element. A communication device that transmits a management frame containing an element that stores parameters used when acquiring transmission rights based on Access (EDCA).

2. The communication device according to claim 1, further comprising information indicating whether a mode is enabled that allows the station to acquire transmission rights based on EDCA in the second communication scheme.

3. The communication device according to claim 2, wherein the information is included in a UHR Operation element located before the element in which parameters used to acquire transmission rights based on the EDCA in the second communication method are stored.

4. The communication device according to claim 2, wherein the information is included in the element that stores parameters used when acquiring transmission rights based on the EDCA in the second communication method.

5. The communication device according to claim 2, wherein the information is indicated by whether or not the AIFSN of the Multi-User (MU) EDCA Parameter Set element is set to a predetermined value.

6. The communication device according to any one of claims 2 to 5, wherein the parameters used in acquiring the right to transmit based on the EDCA in the second communication method are included in the management frame when the information indicates that the mode is enabled, and the communication means transmits the management frame which does not include the parameters used in acquiring the right to transmit based on the EDCA in the second communication method when the information indicates that the mode is not enabled.

7. The communication device according to any one of claims 1 to 6, wherein the management frame is at least one of a Beacon frame, a Probe Response frame, or an Association Response frame.

8. The communication device according to any one of claims 1 to 7, wherein the parameter is a parameter used by the station to determine the backoff parameter for performing the EDCA in the second communication method.

9. The communication device according to claim 8, wherein the parameters are parameters indicating ECWmin and ECWmax to be used in the second communication method.

10. A communication device that functions as a station compliant with the IEEE 802.11 standard, comprising a communication link comprising a first channel used to acquire transmission rights and one or more second channels different from the first channel, wherein the communication means communicates using either a first communication method that uses at least the first channel, or a second communication method that acquires transmission rights using a predetermined channel from the one or more second channels without using the first channel during periods when the first channel cannot be used, wherein the communication means receives a management frame from another communication device operating as an access point, the management frame comprising an Ultra High Reliability (UHR) Capabilities element and an element located after the UHR Capabilities element, which stores parameters used when the station acquires transmission rights based on Enhanced Distributed Channel Access (EDCA) in the second communication method, A communication device that, when using the second communication method described above, acquires transmission rights on the predetermined channel based on EDCA using the parameters described above, and transmits a wireless frame to the access point.

11. The communication device according to claim 10, wherein the management frame further includes an EDCA Parameter Set element or a WMM Parameter element which stores a second parameter used for acquiring the right to transmit on the first channel based on EDCA when the first communication method is used, and the communication means, when the second communication method is used, determines a backoff parameter using a part of the second parameter and the parameter, and acquires the right to transmit on the predetermined channel using the determined backoff parameter.

12. The communication device according to claim 11, wherein the parameters are parameters indicating ECWmin and ECWmax to be used in the second communication method.

13. The communication device according to any one of claims 10 to 12, further comprising information indicating whether a mode is enabled that allows the station to acquire transmission rights on EDCA in the second communication scheme.

14. The communication device according to claim 13, wherein the information is included in a UHR Operation element located before the element that stores parameters used when acquiring transmission rights based on the EDCA in the second communication method.

15. The communication device according to claim 13, wherein the information is included in the element that stores parameters used when acquiring transmission rights based on the EDCA in the second communication method.

16. The communication device according to claim 13, wherein the information is indicated by whether or not the AIFSN of the Multi-User (MU) EDCA Parameter Set element is set to a predetermined value.

17. The communication device according to any one of claims 13 to 16, wherein the parameters used in acquiring the right to transmit based on the EDCA in the second communication method are included in the management frame when the information indicates that the mode is enabled, and the management frame does not include the parameters used in acquiring the right to transmit based on the EDCA in the second communication method when the information indicates that the mode is not enabled.

18. The communication device according to any one of claims 10 to 17, wherein the management frame is at least one of a Beacon frame, a Probe Response frame, or an Association Response frame.

19. A communication method performed by a communication device that functions as an access point compliant with the IEEE 802.11 standard, comprising a communication step in which communication is performed using either a first communication method that uses at least the first channel, or a second communication method that, during periods when the first channel cannot be used, uses a predetermined channel from the one or more second channels to acquire transmission rights, in a single communication link comprising a first channel used to acquire transmission rights and one or more second channels different from the first channel, wherein in the communication step, the communication is performed using an Ultra High Reliability (UHR) Capabilities element and an Enhanced Distributed Channel in the second communication method, which is located after the UHR Capabilities element, to another communication device operating as a station, wherein the station is located behind the UHR Capabilities element. A communication method for transmitting a management frame that includes an element containing parameters used when acquiring transmission rights based on Access (EDCA).

20. A communication method performed by a communication device functioning as a station compliant with the IEEE 802.11 standard, comprising a communication step in which communication is performed using either a first communication method that uses at least the first channel, or a second communication method that, during periods when the first channel cannot be used, uses a predetermined channel from the one or more second channels to acquire transmission rights, in a single communication link comprising a first channel used to acquire transmission rights and one or more second channels different from the first channel, wherein the communication step includes an Ultra High Reliability (UHR) Capabilities element and the station located after the UHR Capabilities element, which in the second communication method is Enhanced Distributed Channel A communication method comprising receiving a management frame including an element that stores parameters used when acquiring transmission rights based on Access (EDCA), and, when using the second communication method, acquiring transmission rights on the predetermined channel based on EDCA using the parameters and transmitting a wireless frame to the access point.

21. A program for causing a computer provided in a communication device that functions as an access point compliant with the IEEE 802.11 standard to execute the communication method described in claim 19.

22. A program for causing a computer provided in a communication device that functions as a station compliant with the IEEE 802.11 standard to execute the communication method described in claim 20.

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