Method and apparatus for transmitting, through management frame, information necessary for performing channel access on non-primary channel in wireless LAN system

Abstract

Presented are a method and an apparatus for transmitting, through a management frame, information necessary for performing channel access on a non-primary channel in a wireless LAN system. Particularly, a reception STA receives a management frame from a transmission STA. The reception STA determines, on the basis of the management frame, whether to perform channel access by switching from a primary 20 MHz channel to a first non-primary channel. The management frame includes first information and second information. The first information is information about whether to obtain information necessary for channel access on the first non-primary channel on the basis of a PHY header or an MAC header.

Description

Method and device for transmitting information required to perform channel access for a non-primary channel in a wireless LAN system through a management frame

[0001] The present specification relates to a technique for transmitting information required for performing channel access to a non-primary channel in a wireless LAN system through a management frame, and more specifically, to a method and device for obtaining information required for channel access to the non-primary channel based on a PHY header or MAC header through the management frame, or for obtaining information on a section in which channel access to the non-primary channel can be performed.

[0002] Next-generation Wi-Fi (e.g., IEEE 802.11be and / or later) aims to support ultra-high reliability when transmitting signals to STAs. To achieve this, various technologies are being considered to support high throughput, low latency, and extended range. For example, procedures for accessing non-primary channels can be performed.

[0003] The present specification proposes a method and device for transmitting information required to perform channel access for a non-primary channel in a wireless LAN system through a management frame.

[0004] An example of this specification proposes a method for conveying information required to perform channel access for a non-primary channel via a management frame.

[0005] The present embodiment can be performed in a network environment that supports a next-generation wireless LAN system (UHR (Ultra High Reliability) wireless LAN system or next wi-fi). The next-generation wireless LAN system is a wireless LAN system that improves the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0006] The present embodiment is performed in a receiving STA, and the receiving STA may correspond to at least one STA (station). The transmitting STA of the present embodiment may correspond to an AP (access point).

[0007] The present embodiment proposes a method for determining whether to perform channel access to a non-primary channel by transmitting information necessary for performing channel access to the non-primary channel through a management frame. Specifically, the present embodiment proposes a method for obtaining information necessary for channel access to the non-primary channel based on a PHY header or MAC header through the management frame, or for obtaining information regarding a section in which channel access to the non-primary channel can be performed.

[0008] A receiving STA (station) receives a management frame from a transmitting STA.

[0009] The above receiving STA determines whether to perform channel access by switching from the primary 20 MHz channel to the first non-primary channel based on the management frame.

[0010] The above management frame includes first and second information.

[0011] The above first information is information on whether information required for channel access to the first non-primary channel is acquired based on a PHY (Physical) header or a MAC (Medium Access Control) header.

[0012] The above second information is information on whether the interval for performing channel access for the first non-primary channel is set to TXOP (transmission opportunity) or PPDU length.

[0013] That is, the present embodiment proposes a method for transmitting information necessary for performing channel access to a non-primary channel through a management frame.

[0014] According to the method proposed by the present embodiment, the AP or STA can have the effect of preventing waste of medium by preventing unnecessary switching from the primary channel to the non-primary channel, or can have the effect of switching at a faster time point so as to obtain a longer TXOP after switching to the non-primary channel.

[0015] Figure 1 illustrates an example of a transmitting device and / or a receiving device of the present specification.

[0016] Figure 2 is a conceptual diagram showing the structure of a wireless local area network (WLAN).

[0017] Figure 3 is a diagram illustrating a general link setup process.

[0018] Figure 4 illustrates one embodiment of a multi-link (ML).

[0019] FIG. 5 illustrates a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received by an STA of this specification.

[0020] Figure 6 is a diagram showing the layout of resource units (RUs) used for 20MHz PPDU.

[0021] Figure 7 is a diagram showing the layout of resource units (RUs) used for 40MHz PPDU.

[0022] Figure 8 is a diagram showing the layout of resource units (RUs) used for 80MHz PPDU.

[0023] Figure 9 shows the operation according to UL-MU.

[0024] Figure 10 shows an example of channels used / supported / defined within the 2.4 GHz band.

[0025] Figure 11 illustrates an example of channels used / supported / defined within the 5 GHz band.

[0026] Figure 12 illustrates an example of channels used / supported / defined within the 6 GHz band.

[0027] Figure 13 shows an example of a header of a MAC frame.

[0028] FIG. 14 illustrates a modified example of a transmitting device and / or a receiving device of the present specification.

[0029] Figure 15 illustrates an example of channel access in an 802.11 wireless LAN system.

[0030] Figure 16 illustrates an example of the basic procedure of SCA.

[0031] Figure 17 shows the basic Secondary Channel Access operation process of STA.

[0032] Figure 18 illustrates an example of an issue regarding the difference in switch time between AP and STA.

[0033] Figure 19 shows an example of the Wait after back-off method (solution #1).

[0034] Figure 20 illustrates an example of a back-off reset scheme (solution #2).

[0035] Fig. 21 is a flowchart illustrating the operation of a transmitting device according to the present embodiment.

[0036] Fig. 22 is a flowchart illustrating the operation of a receiving device according to the present embodiment.

[0037] FIG. 23 is a flowchart illustrating a procedure in which a transmitting STA accesses a non-primary channel and receives a PPDU according to the present embodiment.

[0038] FIG. 24 is a flowchart illustrating a procedure in which a receiving STA accesses a non-primary channel and transmits a PPDU according to the present embodiment.

[0039] In this specification, “A or B” can mean “only A,” “only B,” or “both A and B.” In other words, “A or B” in this specification can be interpreted as “A and / or B.” For example, “A, B or C” in this specification can mean “only A,” “only B,” “only C,” or “any combination of A, B, and C.”

[0040] As used herein, a slash ( / ) or a comma can mean "and / or." For example, "A / B" can mean "and / or B." Accordingly, "A / B" can mean "only A," "only B," or "both A and B." For example, "A, B, C" can mean "A, B, or C."

[0041] In this specification, “at least one of A and B” can mean “only A,” “only B,” or “both A and B.” Additionally, in this specification, the expressions “at least one of A or B” or “at least one of A and / or B” can be interpreted identically to “at least one of A and B.”

[0042] In addition, parentheses used in this specification may mean “for example.” Specifically, when “control information (UHR-Signal field)” is indicated, the “UHR-Signal field” may be suggested as an example of “control information.” In other words, the “control information” in this specification is not limited to the “UHR-Signal field,” and the “UHR-Signal field” may be suggested as an example of “control information.” In addition, even when indicated as “control information (UHR-Signal field),” the “UHR-Signal field” may be suggested as an example of “control information.”

[0043] Additionally, as used herein, “a / an” can mean “at least one” or “one or more.” Additionally, terms ending in “(s)” can mean “at least one” or “one or more.”

[0044] Additionally, the expressions “based on” or “on the basis of” or “according to” used herein mean “based at least in part on” and not “based solely on.”

[0045] Technical features individually described in a single drawing in this specification may be implemented individually or simultaneously.

[0046] The following examples of this specification can be applied to various wireless communication systems. For example, the following examples of this specification can be applied to wireless local area network (WLAN) systems. For example, the following examples of this specification can be applied to the IEEE 802.11a / g / n / ac / ax / be / bn standards. In addition, the examples of this specification can be applied to the Ultra High Reliability (UHR) standard or the next-generation wireless LAN standard that enhances IEEE 802.11bn. In addition, the examples of this specification can be applied to mobile communication systems. For example, the following examples of this specification can be applied to mobile communication systems based on the Long Term Evolution (LTE) and its evolution based on the 3rd Generation Partnership Project (3GPP) standard.

[0047] In order to explain the technical features of this specification, the technical features to which this specification can be applied are described below.

[0048] Figure 1 illustrates an example of a transmitting device and / or a receiving device of the present specification.

[0049] An example of FIG. 1 can perform various technical features described below. FIG. 1 relates to at least one STA (station). For example, the STA (110, 120) of the present specification may also be referred to by various names such as a mobile terminal, a wireless device, a Wireless Transmit / Receive Unit (WTRU), a User Equipment (UE), a Mobile Station (MS), a Mobile Subscriber Unit, or simply a user. The STA (110, 120) of the present specification may also be referred to by various names such as a network, a base station, a Node-B, an access point (AP), a repeater, a router, a relay, etc. The STA (110, 120) of the present specification may also be referred to by various names such as a receiving apparatus, a transmitting apparatus, a receiving STA, a transmitting STA, a receiving device, a transmitting device, etc.

[0050] For example, STA (110, 120) may perform the role of an AP (access point) or a non-AP role. That is, STA (110, 120) of the present specification may perform the functions of an AP and / or a non-AP. In the present specification, AP may also be indicated as an AP STA.

[0051] The STA (110, 120) of this specification can support various communication standards other than the IEEE 802.11 standard. For example, it can support communication standards according to the 3GPP standard (e.g., LTE, LTE-A, 5G NR standard). In addition, the STA of this specification can be implemented in various devices such as mobile phones, vehicles, and personal computers. In addition, the STA of this specification can support communication for various communication services such as voice calls, video calls, data communications, and autonomous driving (Self-Driving, Autonomous-Driving).

[0052] In this specification, STA (110, 120) may include a medium access control (MAC) and a physical layer interface for a wireless medium that follow the provisions of the IEEE 802.11 standard.

[0053] Based on the sub-drawing (a) of Fig. 1, STA (110, 120) is described as follows.

[0054] The first STA (110) may include a processor (111), a memory (112), and a transceiver (113). The illustrated processor, memory, and transceiver may each be implemented as separate chips, or at least two blocks / functions may be implemented through a single chip.

[0055] The transceiver (113) of the first STA performs signal transmission and reception operations. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a / b / g / n / ac / ax / be, etc.).

[0056] For example, the first STA (110) can perform the intended operation of the AP. For example, the processor (111) of the AP can receive a signal through the transceiver (113), process the received signal, generate a transmission signal, and perform control for signal transmission. The memory (112) of the AP can store a signal received through the transceiver (113) (i.e., a reception signal) and store a signal to be transmitted through the transceiver (i.e., a transmission signal).

[0057] For example, the second STA (120) can perform the intended operation of a non-AP STA. For example, the transceiver (123) of the non-AP performs signal transmission and reception operations. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a / b / g / n / ac / ax / be, etc.).

[0058] For example, the processor (121) of the Non-AP STA can receive a signal through the transceiver (123), process the received signal, generate a transmission signal, and perform control for signal transmission. The memory (122) of the Non-AP STA can store a signal received through the transceiver (123) (i.e., a reception signal) and store a signal to be transmitted through the transceiver (i.e., a transmission signal).

[0059] For example, in the specification below, the operation of a device indicated as AP may be performed in the first STA (110) or the second STA (120). For example, if the first STA (110) is an AP, the operation of the device indicated as AP may be controlled by the processor (111) of the first STA (110), and a related signal may be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (110). In addition, control information related to the operation of the AP or a transmission / reception signal of the AP may be stored in the memory (112) of the first STA (110). In addition, when the second STA (110) is an AP, the operation of the device indicated as an AP is controlled by the processor (121) of the second STA (120), and a related signal can be transmitted or received through a transceiver (123) controlled by the processor (121) of the second STA (120). In addition, control information related to the operation of the AP or the transmission / reception signal of the AP can be stored in the memory (122) of the second STA (110).

[0060] For example, in the specification below, the operation of a device indicated as a non-AP (or User-STA) may be performed in the STA (110) or the second STA (120). For example, if the second STA (120) is a non-AP, the operation of the device indicated as a non-AP may be controlled by the processor (121) of the second STA (120), and a related signal may be transmitted or received through a transceiver (123) controlled by the processor (121) of the second STA (120). In addition, control information related to the operation of the non-AP or the transmission / reception signal of the AP may be stored in the memory (122) of the second STA (120). For example, if the first STA (110) is a non-AP, the operation of a device indicated as a non-AP is controlled by the processor (111) of the first STA (110), and a related signal may be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (120). In addition, control information related to the operation of the non-AP or the transmission / reception signal of the AP may be stored in the memory (112) of the first STA (110).

[0061] In the following specification, devices called (transmitting / receiving) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmitting / receiving) Terminal, (transmitting / receiving) device, (transmitting / receiving) apparatus, network, etc. may refer to the STA (110, 120) of FIG. 1. For example, devices indicated as (transmitting / receiving) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmitting / receiving) Terminal, (transmitting / receiving) device, (transmitting / receiving) apparatus, network, etc. without specific drawing symbols may also refer to the STA (110, 120) of FIG. 1. For example, in the example below, the operation of various STAs transmitting and receiving signals (e.g., PPPDU) may be performed by the transceiver (113, 123) of FIG. 1. In addition, in the example below, the operation of various STAs generating transmission and reception signals or performing data processing or calculations in advance for transmission and reception signals may be performed by the processor (111, 121) of FIG. 1.For example, an example of an operation that generates a transmission / reception signal or performs data processing or operation in advance for a transmission / reception signal may include 1) an operation of determining / obtaining / configuring / computing / decoding / encoding bit information of a subfield (SIG, STF, LTF, Data) field included in a PPDU, 2) an operation of determining / configuring / obtaining time resources or frequency resources (e.g., subcarrier resources) used for a subfield (SIG, STF, LTF, Data) field included in a PPDU, 3) an operation of determining / configuring / obtaining a specific sequence (e.g., a pilot sequence, an STF / LTF sequence, an extra sequence applied to SIG) used for a subfield (SIG, STF, LTF, Data) field included in a PPDU, 4) a power control operation and / or a power saving operation applied to an STA, 5) an operation related to determining / obtaining / configuring / computing / decoding / encoding an ACK signal, etc. Additionally, in the examples below, various information (e.g., information related to fields / subfields / control fields / parameters / power, etc.) used by various STAs for determining / acquiring / configuring / computing / decoding / encoding transmission / reception signals can be stored in the memory (112, 122) of FIG. 1.

[0062] The device / STA of the sub-drawing (a) of the above-described FIG. 1 can be modified as in the sub-drawing (b) of FIG. 1. Hereinafter, the STA (110, 120) of the present specification will be described based on the sub-drawing (b) of FIG. 1.

[0063] For example, the transceiver (113, 123) illustrated in sub-drawing (b) of FIG. 1 may perform the same function as the transceiver illustrated in sub-drawing (a) of FIG. 1 described above. For example, the processing chip (114, 124) illustrated in sub-drawing (b) of FIG. 1 may include a processor (111, 121) and a memory (112, 122). The processor (111, 121) and the memory (112, 122) illustrated in sub-drawing (b) of FIG. 1 may perform the same function as the processor (111, 121) and the memory (112, 122) illustrated in sub-drawing (a) of FIG. 1 described above.

[0064] The mobile terminal, wireless device, Wireless Transmit / Receive Unit (WTRU), User Equipment (UE), Mobile Station (MS), Mobile Subscriber Unit, user, user STA, network, Base Station, Node-B, Access Point (AP), repeater, router, relay, receiving device, transmitting device, receiving STA, transmitting STA, receiving Device, transmitting Device, receiving Apparatus, and / or transmitting Apparatus described below may refer to the STA (110, 120) illustrated in the sub-drawings (a) / (b) of FIG. 1, or may refer to the processing chip (114, 124) illustrated in the sub-drawing (b) of FIG. 1. That is, the technical feature of the present specification may be performed in the STA (110, 120) illustrated in the sub-drawings (a) / (b) of FIG. 1, or may be performed only in the processing chip (114, 124) illustrated in the sub-drawings (b) of FIG. 1. For example, the technical feature that the transmitting STA transmits a control signal may be understood as a technical feature that the control signal generated in the processor (111, 121) illustrated in the sub-drawings (a) / (b) of FIG. 1 is transmitted through the transceiver (113, 123) illustrated in the sub-drawings (a) / (b) of FIG. 1. Alternatively, the technical feature that the transmitting STA transmits a control signal may be understood as a technical feature that the control signal to be transmitted to the transceiver (113, 123) is generated in the processing chip (114, 124) illustrated in the sub-drawings (b) of FIG. 1.

[0065] For example, the technical feature of a receiving STA receiving a control signal can be understood as a technical feature of a control signal being received by a transceiver (113, 123) illustrated in sub-drawing (a) of FIG. 1. Alternatively, the technical feature of a receiving STA receiving a control signal can be understood as a technical feature of a control signal received by a transceiver (113, 123) illustrated in sub-drawing (a) of FIG. 1 being acquired by a processor (111, 121) illustrated in sub-drawing (a) of FIG. 1. Alternatively, the technical feature of a receiving STA receiving a control signal can be understood as a technical feature of a control signal received by a transceiver (113, 123) illustrated in sub-drawing (b) of FIG. 1 being acquired by a processing chip (114, 124) illustrated in sub-drawing (b) of FIG.

[0066] Referring to the sub-drawing (b) of FIG. 1, software code (115, 125) may be included in the memory (112, 122). The software code (115, 125) may include instructions that control the operation of the processor (111, 121). The software code (115, 125) may be included in various programming languages.

[0067] The processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit, and / or a data processing device. The processor may be an application processor (AP). For example, the processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator). For example, the processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may be a SNAPDRAGON™ series processor manufactured by Qualcomm®, an EXYNOSTM series processor manufactured by Samsung®, an A series processor manufactured by Apple®, a HELIO™ series processor manufactured by MediaTek®, an ATOM™ series processor manufactured by INTEL®, or an enhanced processor thereof.

[0068] In this specification, uplink may mean a link for communication from a non-AP STA to an AP STA, and uplink PPDU / packet / signal, etc. may be transmitted through the uplink. In addition, in this specification, downlink may mean a link for communication from an AP STA to a non-AP STA, and downlink PPDU / packet / signal, etc. may be transmitted through the downlink.

[0069] Figure 2 is a conceptual diagram showing the structure of a wireless local area network (WLAN).

[0070] The upper part of Figure 2 shows the structure of the infrastructure BSS (basic service set) of IEEE (institute of electrical and electronic engineers) 802.11.

[0071] The upper part of Figure 2 shows the structure of the infrastructure BSS (basic service set) of IEEE (institute of electrical and electronic engineers) 802.11.

[0072] Referring to the top of FIG. 2, the wireless LAN system may include one or more infrastructure BSSs (200, 205) (hereinafter, BSS). The BSSs (200, 205) are a collection of APs and STAs, such as an access point (AP) 225 and a station (STA1, 200-1), that have successfully synchronized and can communicate with each other, and are not a concept that designates a specific area. The BSS (205) may also include one or more STAs (205-1, 205-2) that can be associated with one AP (230).

[0073] A BSS may include at least one STA, an AP (225, 230) providing a distribution service, and a distribution system (DS, 210) connecting multiple APs.

[0074] A distributed system (210) can connect multiple BSSs (200, 205) to implement an extended service set (ESS, 240). An ESS (240) can be used as a term to indicate a network formed by connecting one or more APs through the distributed system (210). APs included in a single ESS (240) can have the same SSID (service set identification).

[0075] The portal (portal, 220) can act as a bridge to connect a wireless LAN network (IEEE 802.11) to another network (e.g., 802.X).

[0076] In a BSS such as the upper part of Fig. 2, a network between APs (225, 230) and a network between APs (225, 230) and STAs (200-1, 205-1, 205-2) can be implemented. However, it may also be possible to establish a network and perform communication between STAs without an AP (225, 230). A network that establishes a network and performs communication between STAs without an AP (225, 230) is defined as an ad-hoc network or an independent basic service set (IBSS).

[0077] The bottom of Figure 2 is a conceptual diagram showing IBSS.

[0078] Referring to the bottom of Fig. 2, the IBSS is a BSS that operates in ad-hoc mode. Since the IBSS does not include an AP, there is no centralized management entity. That is, in the IBSS, the STAs (250-1, 250-2, 250-3, 255-4, 255-5) are managed in a distributed manner. In the IBSS, all STAs (250-1, 250-2, 250-3, 255-4, 255-5) can be mobile STAs, and access to the distributed system is not permitted, forming a self-contained network.

[0079] Figure 3 is a diagram illustrating a general link setup process.

[0080] In step S310, the STA may perform a network discovery operation. This network discovery operation may include scanning by the STA. That is, for the STA to access the network, it must find a network it can join. Before joining a wireless network, the STA must identify compatible networks. The process of identifying networks in a specific area is called scanning. Scanning methods include active scanning and passive scanning.

[0081] Figure 3 illustrates a network discovery operation that includes an active scanning process as an example. In active scanning, an STA performing scanning transmits a probe request frame to discover which APs exist in the vicinity while moving between channels and waits for a response. A responder transmits a probe response frame to the STA that transmitted the probe request frame in response to the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame in the BSS of the channel being scanned. In a BSS, the AP transmits the beacon frame, so the AP becomes the responder. In an IBSS, the STAs within the IBSS take turns transmitting beacon frames, so the responder is not constant. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 can store BSS-related information included in the received probe response frame and move to the next channel (e.g., channel 2) to perform scanning (i.e., transmitting and receiving probe requests / responses on channel 2) in the same manner.

[0082] Although not shown in the example of FIG. 3, the scanning operation can also be performed in a passive scanning manner. An STA performing scanning based on passive scanning can wait for a beacon frame while moving between channels. A beacon frame is one of the management frames in IEEE 802.11. It announces the presence of a wireless network and is periodically transmitted so that the scanning STA can find the wireless network and participate in the wireless network. In the BSS, the AP periodically transmits the beacon frame, and in the IBSS, the STAs within the IBSS take turns transmitting the beacon frame. When the scanning STA receives a beacon frame, it stores the information about the BSS included in the beacon frame and moves to another channel, recording the beacon frame information on each channel. An STA that receives a beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform scanning on the next channel in the same manner.

[0083] An STA that discovers a network can perform an authentication process through step S320. This authentication process may be referred to as the first authentication process to clearly distinguish it from the security setup operation of step S340 described below. The authentication process of S320 may include a process in which the STA transmits an authentication request frame to the AP, and the AP responds by transmitting an authentication response frame to the STA. The authentication frame used for the authentication request / response corresponds to a management frame.

[0084] The authentication frame may include information such as an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a Robust Security Network (RSN), and a Finite Cyclic Group.

[0085] An STA can transmit an authentication request frame to an AP. The AP can determine whether to grant authentication to the STA based on the information contained in the received authentication request frame. The AP can provide the result of the authentication process to the STA via an authentication response frame.

[0086] A successfully authenticated STA may perform an association process based on step S330. The association process includes a process in which the STA transmits an association request frame to the AP, and the AP transmits an association response frame to the STA in response. For example, the association request frame may include information related to various capabilities, such as a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, RSN, mobility domain, supported operating classes, a Traffic Indication Map Broadcast request, and interworking service capabilities. For example, the association response frame may contain information related to various capabilities, status codes, Association ID (AID), supported rates, Enhanced Distributed Channel Access (EDCA) parameter sets, Received Channel Power Indicator (RCPI), Received Signal to Noise Indicator (RSNI), mobility domains, timeout interval (association comeback time), overlapping BSS scan parameters, TIM broadcast response, QoS maps, etc.

[0087] In step S340, the STA may perform a security setup process. The security setup process of step S340 may include, for example, a process of setting up a private key through a four-way handshaking using an Extensible Authentication Protocol over LAN (EAPOL) frame.

[0088] Figure 4 illustrates one embodiment of a multi-link (ML).

[0089] As illustrated in FIG. 4, multiple multi-link devices (MLDs) can communicate over a remote link. The MLDs can be categorized into AP MLDs including multiple AP STAs and non-AP MLDs including multiple non-AP STAs. That is, the AP MLD can include affiliated APs (i.e., AP STAs), and the non-AP MLD can include affiliated STAs (i.e., non-AP STAs, or user-STAs).

[0090] A multilink may include a first link and a second link, and different channels / subchannels / frequency resources may be allocated to the first and second links. The first and second multilinks may be identified through a link ID of 4 bits (or other n bits). The first and second links may be configured in the same 2.4 GHz, 5 GHz, or 6 GHz band. Alternatively, the first link and the second link may be configured in different bands.

[0091] The AP MLD of FIG. 4 includes three affiliated APs. In the example of FIG. 4, AP1 may operate in the 2.4 GHz band, AP2 may operate in the 5 GHz band, and AP3 may operate in the 6 GHz band. In the example of FIG. 4, the first link in which AP1 and non-AP1 operate may be defined as a channel / subchannel / frequency resource within the 2.4 GHz band. Furthermore, in the example of FIG. 4, the second link in which AP2 and non-AP2 operate may be defined as a channel / subchannel / frequency resource within the 5 GHz band. Furthermore, in the example of FIG. 4, the third link in which AP3 and non-AP3 operate may be defined as a channel / subchannel / frequency resource within the 6 GHz band.

[0092] In the example of FIG. 4, AP1 may initiate a multi-link setup procedure (ML setup procedure) by transmitting an Association Request frame to non-AP STA1. In the example of FIG. 4, non-AP STA1 may transmit an Association Response frame in response to the Association Request frame. Each AP (e.g., AP1 / 2 / 3) illustrated in FIG. 4 may be identical to the AP illustrated in FIG. 1 and / or FIG. 2, and each non-AP (e.g., non-AP1 / 2 / 3) illustrated in FIG. 4 may be identical to the STA (i.e., user-STA or non-AP STA) illustrated in FIG. 1 and / or FIG. 2.

[0093] The specific features of this specification are not limited to the specific features of FIG. 4. That is, the number of links can be defined in various ways, and multiple links can be defined in various ways within at least one band.

[0094] FIG. 5 illustrates a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received by an STA of this specification.

[0095] The STA (e.g., AP STA, non-AP STA, AP MLD, non-AP MLD) of the present specification can transmit and / or receive the PPDU of FIG. 5. The PPDU described in the present specification may have, for example, the structure of FIG. 5. In addition, the PPDU described in the present specification may be called by various names such as a transmission PPDU, a reception PPDU, a first type PPDU, or an Nth type PPDU, etc. The PPDU described in the present specification can be used in a WLAN system defined according to IEEE 802.11bn and / or a next-generation WLAN system that improves IEEE 802.11bn.

[0096] The PPDU of FIG. 5 may be related to various PPDU types used in a UHR system. For example, the example of FIG. 5 may be used for at least one of a single-user (SU) mode / type / transmission, a multi-user (MU) mode / type / transmission, and a null data packet (NDP) mode / type / transmission related to channel sounding. For example, if the example of FIG. 5 is related to NDP, the Data field illustrated may be omitted. If the PPDU of FIG. 5 is used for a trigger-based (TB) mode, the UHR-SIG of FIG. 5 may be omitted. In other words, an STA that has received a trigger frame for UL-MU (Uplink-MU) communication may transmit a PPDU with the UHR-SIG omitted in the example of FIG. 5.

[0097] In FIG. 5, L-STF or UHR-LTF may be called a preamble or physical preamble, and may be generated / transmitted / received / acquired / decoded in the physical layer (included in the transmitting / receiving STA).

[0098] Each block illustrated in Fig. 5 may be called a field / subfield / signal, etc. The names of these fields / subfields / signals may be, as illustrated in Fig. 5, L-STF (legacy short training field), L-LTF (legacy long training field), L-SIG (legacy signal), RL-SIG (repeated L-SIG), U-SIG (Universal Signal), UHR-SIG (UHR-signal), etc.

[0099] The subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields in FIG. 5 may be set to 312.5 kHz, and the subcarrier spacing of the UHR-STF, UHR-LTF, and Data fields may be set to 78.125 kHz. That is, the tone index (or subcarrier index) of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields may be expressed in units of 312.5 kHz, and the tone index (or subcarrier index) of the UHR-STF, UHR-LTF, and Data fields may be expressed in units of 78.125 kHz.

[0100] In the PPDU of Fig. 5, L-LTF and L-STF may be identical to conventional fields (e.g., non-HT LTF and non-HT STF defined in conventional WLAN standards).

[0101] The L-SIG field of FIG. 5 may include, for example, 24 bits of bit information. For example, the 24 bits of information may include a 4 bit Rate field, a 1 bit Reserved bit, a 12 bit Length field, a 1 bit Parity bit, and a 6 bit Tail bit. For example, the 12 bit Length field may include information about the length or time duration of the PPDU. For example, the value of the 12 bit Length field may be determined based on the type of the PPDU. For example, if the PPDU is a non-HT (non-High Throughput), HT (High Throughput), VHT (Very High Throughput) PPDU, or an EHT (extremely high throughput) PPDU or UHR PPDU, the value of the Length field may be determined as a multiple of 3. For example, if the PPDU is a HE PPDU, the value of the Length field may be determined as "a multiple of 3 + 1" or "a multiple of 3 + 2". In other words, for non-HT, HT, VHT PPDU, EHT PPDU, UHR PPDU, the value of the Length field can be determined as a multiple of 3, and for HE (High-Efficiency) PPDU, the value of the Length field can be determined as "a multiple of 3 + 1" or "a multiple of 3 + 2". In other words, the Length field in an UHR PPDU is set to a value satisfying the condition that the remainder is zero when LENGTH is divided by 3.

[0102] For example, (non-AP and AP) STAs can apply BCC encoding based on a code rate of 1 / 2 to the 24 bits of information in the L-SIG field. Then, the transmitting STA can obtain 48 BCC coded bits. BPSK modulation can be applied to the 48 coded bits to generate 48 BPSK symbols. The transmitting STA can map the 48 BPSK symbols to positions excluding the pilot subcarriers {subcarrier index -21, -7, +7, +21} and the DC subcarrier {subcarrier index 0}. As a result, the 48 BPSK symbols can be mapped to subcarrier indices -26 to -22, -20 to -8, -6 to -1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA can additionally map the signal {-1, -1, -1, 1} to the subcarrier indices {-28, -27, +27, +28}. The above signal can be used for channel estimation for the frequency domain corresponding to {-28, -27, +27, +28}.

[0103] For example, (non-AP and AP) STA can generate RL-SIG, which is generated in the same manner as L-SIG. BPSK modulation can be applied to RL-SIG. Receiving (non-AP and AP) STA can determine whether the received PPDU is a HE PPDU, EHT PPDU, or UHR PPDU based on the presence of RL-SIG. In other words, if RL-SIG is present, receiving (non-AP and AP) STA can determine whether the received PPDU is one of HE PPDU, EHT PPDU, or UHR PPDU. In other words, if RL-SIG is not present, receiving (non-AP and AP) STA can determine whether the received PPDU is one of non-HT PPDU, HT PPDU, or VHT PPDU. In other words, the RL-SIG field is a repeat of the L-SIG field and is used to differentiate an UHR PPDU from a non-HT PPDU, HT PPDU, and VHT PPDU.

[0104] After the RL-SIG in Fig. 5, a U-SIG (Universal SIG) may be inserted. The U-SIG may be called by various names such as the first SIG field, the first SIG, the first type SIG, the control signal, the control signal field, the first (type) control signal, the common control field, and the common control signal.

[0105] A U-SIG can contain N bits of information and can include information for identifying the type of EHT PPDU. For example, a U-SIG can be formed based on two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., an OFDM symbol) for a U-SIG can have a duration of 4 microseconds. Each symbol of a U-SIG can be used to transmit 26 bits of information. For example, each symbol of a U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0106] For example, A bit information (e.g., 52 uncoded bits) can be transmitted through U-SIG, and the first symbol of U-SIG can transmit the first X bits of information (e.g., 26 uncoded bits) out of the total A bit information, and the second symbol of U-SIG can transmit the remaining Y bits of information (e.g., 26 uncoded bits) out of the total A bit information. For example, the transmitting STA can obtain 26 uncoded bits included in each U-SIG symbol. The transmitting STA can perform convolutional encoding (i.e., BCC encoding) based on a rate of R=1 / 2 to generate 52 coded bits, and perform interleaving on the 52 coded bits. The transmitting STA can perform BPSK modulation on the interleaved 52 coded bits to generate 52 BPSK symbols allocated to each U-SIG symbol. A single U-SIG symbol can be transmitted based on 56 tones (subcarriers) from subcarrier index -28 to subcarrier index +28, excluding DC index 0. The 52 BPSK symbols generated by the transmitting STA can be transmitted based on the remaining tones (subcarriers) excluding the pilot tones -21, -7, +7, and +21.

[0107] For example, A bit information (e.g., 52 uncoded bits) transmitted by U-SIG may include a CRC field (e.g., a 4-bit long field) and a tail field (e.g., a 6-bit long field). The CRC field and the tail field may be transmitted through the second symbol of the U-SIG. The CRC field may be generated based on 26 bits allocated to the first symbol of the U-SIG and the remaining 16 bits excluding the CRC / tail field within the second symbol, and may be generated based on a conventional CRC calculation algorithm. In addition, the tail field may be used to terminate the trellis of the convolutional decoder and may be set to, for example, "000000".

[0108] The A bit information (e.g., 52 uncoded bits) transmitted by the U-SIG (or U-SIG field) can be divided into version-independent bits and version-dependent bits. For example, the size of the version-independent bits can be fixed or variable. For example, the version-independent bits can be assigned only to the first symbol of the U-SIG, or the version-independent bits can be assigned to both the first symbol and the second symbol of the U-SIG. For example, the version-independent bits and the version-dependent bits can be called by various names, such as the first control bit and the second control bit.

[0109] For example, the version-independent bits of the U-SIG may include a 3-bit PHY version identifier. For example, the 3-bit PHY version identifier may include information related to the PHY version of the transmitted and received PPDU. For example, a first value (e.g., a value of 000) of the 3-bit PHY version identifier may indicate that the transmitted and received PPDU is an EHT PPDU. In addition, a second value (e.g., a value of 001) of the 3-bit PHY version identifier may indicate that the transmitted and received PPDU is an UHR PPDU.

[0110] In other words, when the (AP / non-AP) STA transmits an EHT PPDU, it can set the 3-bit PHY version identifier to the first value. In other words, the receiving (AP / non-AP) STA can determine that the received PPDU is an EHT PPDU based on the PHY version identifier having the first value, and can determine that the received PPDU is an UHR PPDU based on the PHY version identifier having the second value.

[0111] For example, the version-independent bits of U-SIG may include a 1-bit UL / DL flag field. The first value of the 1-bit UL / DL flag field relates to UL communication, and the second value of the UL / DL flag field relates to DL communication.

[0112] For example, the version-independent bits of U-SIG may include information about the length of a transmission opportunity (TXOP) and information about the BSS color ID.

[0113] For example, if a UHR PPDU is classified into various types (e.g., a type related to SU transmission (performed based on UL or DL), a type related to DL transmission, a type related to NDP transmission, a type related to DL non-MU-MIMO, a type related to DL MU-MIMO, a type related to Multi-AP operation, a type related to CBF (Coordinated beamforming), SR (Spatial Reuse), a type related to C-OFDMA (Coordinated OFDMA), a type related to C-TDMA (Coordinated TDMA)), information about the type of the EHT PPDU (e.g., 2-bit or 3-bit information) can be included in the version-dependent bits of the U-SIG.

[0114] For example, a U-SIG may include information about 1) a bandwidth field including information about a bandwidth, 2) a field including information about an MCS technique applied to the UHR-SIG, 3) an indication field including information about whether a dual subcarrier modulation (DCM) technique is applied to the UHR-SIG, 4) a field including information about the number of symbols used for the UHR-SIG, 5) a field including information about whether the UHR-SIG is generated over the entire band, 6) a field including information about the type of UHR-LTF / STF, and 7) a field indicating the length of the UHR-LTF and the CP length.

[0115] Preamble puncturing may be applied to the PPDU of FIG. 5. Preamble puncturing refers to applying puncturing to a portion of the entire bandwidth of the PPDU (e.g., the secondary 20 MHz band). For example, when an 80 MHz PPDU is transmitted, the STA applies puncturing to the secondary 20 MHz band within the 80 MHz band, and can transmit the PPDU only through the primary 20 MHz band and the secondary 40 MHz band.

[0116] For example, the pattern of preamble puncturing can be preset. For example, when the first puncturing pattern is applied, puncturing can be applied only to the secondary 20 MHz band within the 80 MHz band. For example, when the second puncturing pattern is applied, puncturing can be applied only to one of the two secondary 20 MHz bands included in the secondary 40 MHz band within the 80 MHz band. For example, when the third puncturing pattern is applied, puncturing can be applied only to the secondary 20 MHz band included in the primary 80 MHz band within the 160 MHz band (or 80+80 MHz band). For example, when the fourth puncturing pattern is applied, a primary 40 MHz band included in the primary 80 MHz band within the 160 MHz band (or 80+80 MHz band) may be present, and puncturing may be applied to at least one 20 MHz channel that does not belong to the primary 40 MHz band.

[0117] Information regarding preamble puncturing applied to the PPDU may be included in the U-SIG and / or UHR-SIG. For example, the first field of the U-SIG may include information regarding the contiguous bandwidth of the PPDU, and the second field of the U-SIG may include information regarding preamble puncturing applied to the PPDU.

[0118] For example, U-SIG and UHR-SIG may include information regarding preamble puncturing based on the following method. If the bandwidth of the PPDU exceeds 80 MHz, the U-SIG may be individually configured in units of 80 MHz. For example, if the bandwidth of the PPDU is 160 MHz, the PPDU may include a first U-SIG for the first 80 MHz band and a second U-SIG for the second 80 MHz band. In this case, the first field of the first U-SIG may include information regarding the 160 MHz bandwidth, and the second field of the first U-SIG may include information regarding preamble puncturing applied to the first 80 MHz band (i.e., information regarding the preamble puncturing pattern). Additionally, the first field of the second U-SIG may include information about a 160 MHz bandwidth, and the second field of the second U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about a preamble puncturing pattern). Meanwhile, the UHR-SIG consecutive to the first U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about a preamble puncturing pattern), and the UHR-SIG consecutive to the second U-SIG may include information about preamble puncturing applied to the first 80 MHz band (i.e., information about a preamble puncturing pattern).

[0119] Additionally or alternatively, U-SIG and UHR-SIG may include information regarding preamble puncturing based on the following methods. U-SIG may include information regarding preamble puncturing for all bands (i.e., information regarding preamble puncturing patterns). That is, UHR-SIG may not include information regarding preamble puncturing, and only U-SIG may include information regarding preamble puncturing (i.e., information regarding preamble puncturing patterns).

[0120] U-SIGs can be configured in 20 MHz units. For example, if an 80 MHz PPDU is configured, U-SIGs can be duplicated. That is, four identical U-SIGs can be included within an 80 MHz PPDU. PPDUs exceeding the 80 MHz bandwidth can contain different U-SIGs.

[0121] The UHR-SIG of FIG. 5 may include control information for a receiving STA. The UHR-SIG may be transmitted via at least one symbol, and each symbol may have a length of 4 us. Information regarding the number of symbols used for the UHR-SIG may be included in the U-SIG.

[0122] UHR-SIG provides additional signals to the U-SIG field to enable STAs to interpret / decode UHR PPDUs. The UHR-SIG field may contain U-SIG overflow bits that are common to all users. The UHR-SIG field also contains resource allocation information, allowing STAs to look up resources used in fields containing data fields / UHR-STF / UHR-LTF (i.e., UHR modulated fields of an UHR PPDU).

[0123] The frequency resources of the UHR-LTF, UHR-STF, and data fields illustrated in FIG. 5 can be determined based on RUs (resource units) defined by multiple subcarriers / tones. That is, the UHR-LTF, UHR-STF, and data fields of this specification can be transmitted / received through RUs (resource units) defined by multiple subcarriers / tones.

[0124] FIG. 6 is a diagram illustrating the layout of resource units (RUs) used for a 20 MHz PPDU. That is, the UHR-LTF, UHR-STF, and / or data fields included in the 20 MHz PPDU can be transmitted / received through at least one of the various RUs defined in FIG. 6.

[0125] As shown at the top of Fig. 6, 26 units (i.e., units corresponding to 26 tones) can be arranged. Six tones can be used as a guard band in the leftmost band of the 20 MHz band, and five tones can be used as a guard band in the rightmost band of the 20 MHz band. In addition, seven DC tones can be inserted in the center band, i.e., the DC band, and 26 units corresponding to 13 tones can exist on each side of the DC band. In addition, 26 units, 52 units, and 106 units can be allocated to other bands. Each unit can be allocated for a receiving station, i.e., a user.

[0126] Meanwhile, the RU arrangement of FIG. 6 is utilized not only in a situation for multiple users (MUs) but also in a situation for a single user (SU), in which case it is possible to use one 242-unit as shown at the bottom of FIG. 4, in which case three DC tones can be inserted.

[0127] In the example of Fig. 6, RUs of various sizes, such as 26-RU, 52-RU, 106-RU, and 242-RU, are proposed. Since the specific sizes of these RUs can be expanded or increased, the present embodiment is not limited to the specific size of each RU (i.e., the number of corresponding tones). In this specification, N-RU may be represented as N-tone RU, etc. For example, 26-RU may be represented as 26-tone RU.

[0128] Figure 7 is a diagram showing the layout of resource units (RUs) used for 40MHz PPDU.

[0129] As in the example of Fig. 6 where RUs of various sizes were used, the example of Fig. 7 can also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. In addition, 5 DC tones can be inserted at the center frequency, 12 tones can be used as a guard band in the leftmost band of the 40 MHz band, and 11 tones can be used as a guard band in the rightmost band of the 40 MHz band.

[0130] Additionally, as illustrated, 484 RUs may be used when used for a single user. Meanwhile, the specific number of RUs may be changed, as in the example of FIG. 6.

[0131] Figure 8 is a diagram illustrating the layout of resource units (RUs) used for an 80MHz PPDU. The layout of resource units (RUs) used in this specification may vary. For example, the layout of resource units (RUs) used in the 80MHz band may vary.

[0132] Figure 9 illustrates an operation according to UL-MU. As illustrated, a transmitting STA (e.g., AP) can perform channel access through contending (i.e., backoff operation) and transmit a trigger frame (930). That is, the transmitting STA (e.g., AP) can transmit a PPDU including a trigger frame (930). When a PPDU including a trigger frame is received, a TB (trigger-based) PPDU is transmitted after a delay of SIFS.

[0133] TB PPDUs (941, 942) are transmitted at the same time and can be transmitted from multiple STAs (e.g., User STAs) whose AIDs are indicated in the Trigger frame (930). The ACK frame (950) for the TB PPDU can be implemented in various forms.

[0134] Figure 10 shows an example of channels used / supported / defined within the 2.4 GHz band.

[0135] The 2.4 GHz band may be referred to by other names, such as the first band (band). Furthermore, the 2.4 GHz band may refer to a frequency range in which channels with a center frequency adjacent to 2.4 GHz (e.g., channels with a center frequency between 2.4 and 2.5 GHz) are used / supported / defined.

[0136] The 2.4 GHz band may include multiple 20 MHz channels. The 20 MHz within the 2.4 GHz band may have multiple channel indices (e.g., indices 1 through 14). For example, the center frequency of a 20 MHz channel assigned channel index 1 may be 2.412 GHz, the center frequency of a 20 MHz channel assigned channel index 2 may be 2.417 GHz, and the center frequency of a 20 MHz channel assigned channel index N may be (2.407 + 0.005*N) GHz. The channel indices may be referred to by various names, such as channel numbers. The specific numerical values ​​of the channel indices and center frequencies may change.

[0137] Figure 10 exemplarily illustrates four channels within the 2.4 GHz band. The illustrated first frequency region (1010) to fourth frequency region (1040) may each include one channel. For example, the first frequency region (1010) may include channel 1 (a 20 MHz channel having an index of 1). In this case, the center frequency of channel 1 may be set to 2412 MHz. The second frequency region (1020) may include channel 6. In this case, the center frequency of channel 6 may be set to 2437 MHz. The third frequency region (1030) may include channel 11. In this case, the center frequency of channel 11 may be set to 2462 MHz. The fourth frequency region (1040) may include channel 14. In this case, the center frequency of channel 14 may be set to 2484 MHz.

[0138] Figure 11 illustrates an example of channels used / supported / defined within the 5 GHz band.

[0139] The 5 GHz band may be referred to by other names, such as a second band / band, etc. The 5 GHz band may refer to a frequency range in which channels with center frequencies greater than or equal to 5 GHz and less than 6 GHz (or less than 5.9 GHz) are used / supported / defined. Alternatively, the 5 GHz band may include multiple channels between 4.5 GHz and 5.5 GHz. The specific figures shown in FIG. 11 are subject to change.

[0140] Multiple channels within the 5 GHz band include Unlicensed National Information Infrastructure (UNII)-1, UNII-2, UNII-3, and ISM. UNII-1 may be referred to as UNII Low. UNII-2 may include frequency ranges called UNII Mid and UNII-2Extended. UNII-3 may be referred to as UNII-Upper.

[0141] Within the 5 GHz band, multiple channels can be configured, and the bandwidth of each channel can be variously configured, such as 20 MHz, 40 MHz, 80 MHz, or 160 MHz. For example, the 5170 MHz to 5330 MHz frequency domain / range within UNII-1 and UNII-2 can be divided into eight 20 MHz channels. The 5170 MHz to 5330 MHz frequency domain / range can be divided into four channels through a 40 MHz frequency domain. The 5170 MHz to 5330 MHz frequency domain / range can be divided into two channels through an 80 MHz frequency domain. Alternatively, the 5170 MHz to 5330 MHz frequency domain / range can be divided into one channel through a 160 MHz frequency domain.

[0142] Figure 12 illustrates an example of channels used / supported / defined within the 6 GHz band.

[0143] The 6 GHz band may also be referred to by other names, such as the third band / band. The 6 GHz band may refer to the frequency range in which channels with center frequencies above 5.9 GHz are used, supported, or defined. The specific figures shown in Figure 12 are subject to change.

[0144] For example, the 20 MHz channel of FIG. 12 can be defined from 5.940 GHz. Specifically, the leftmost channel among the 20 MHz channels of FIG. 12 can have an index of 1 (or channel index, channel number, etc.), and a center frequency of 5.945 GHz can be assigned. That is, the center frequency of the indexed channel N can be determined as (5.940 + 0.005*N) GHz.

[0145] Accordingly, the indexes (or channel numbers) of the 20 MHz channels of FIG. 12 are 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 169, 173, 177, 181, 185, 189, 193, It can be 197, 201, 205, 209, 213, 217, 221, 225, 229, 233. Also, according to the (5.940 + 0.005*N) GHz rule mentioned above, the indices of the 40 MHz channels in Fig. 12 can be 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227.

[0146] Below, the structure and types / subtypes of MAC frames are described.

[0147] Fig. 13 illustrates an example of a header of a MAC frame. As illustrated, the MAC frame may include a frame control field / information of 2 octets in length, a duration field / information of 2 octets in length, a RA (Receiver Address) field / information of 6 octets in length, and a TA (Transmitter Address) field / information of 6 octets in length. As illustrated in Fig. 13, the four fields may be consecutive to each other. The MAC header of Fig. 13 may be modified in various ways, and a new field may be inserted between the four illustrated fields, or at least one of the illustrated fields may be omitted.

[0148] The MAC header illustrated in Fig. 13 may be positioned at the very front of a MAC frame. That is, the MAC frame may include a MAC header as illustrated in Fig. 13 and MAC body fields / information subsequent to the MAC header. The MAC frame including the MAC header of Fig. 13 is inserted / included in the data field of the PPDU (e.g., UHR PPDU) illustrated in Fig. 5.

[0149] The MAC frames included in the data field of the PPDU of this specification can be classified into various types. For example, the MAC frames of this specification can be classified into control frames, management frames, and data frames.

[0150] For example, the management frame includes Association Request, Association Response, Reassociation Request, Reassociation Response, Probe Request, Probe Response, Beacon, Disassociation, Authentication, and Deauthentication frames / signals defined in conventional WLAN. For the management frame, the values ​​of the type fields (B3 and B2) in FIG. 13 are set to 00. In addition, the values ​​of the subtype fields (B7, B6, B5, B4) in FIG. 13 are as follows: Association Request (0000), Association Response (0001), Reassociation Request (0010), Reassociation Response (0011), Probe Request (0100), Probe Response (0101), Beacon (1000), Disassociation (1010), Authentication (1011), Deauthentication (1100).

[0151] For example, the control frame includes Trigger Beamforming Report Poll, NDP Announcement (NDPA), Control Frame Extension, Control Wrapper, Block Ack Request (BlockAckReq), Block Ack (BlockAck), PS-Poll, RTS, CTS, Ack, and CF-End frames / signals defined in conventional WLAN. For the control frame, the value of the type field (B3 and B2) in FIG. 13 is set to 01. Also, the values ​​of the subtype fields (B7, B6, B5, B4) of FIG. 13 are as follows: Trigger (0010), Beamforming Report Poll (0100), NDP Announcement (0101), Control Frame Extension (0110), Control Wrapper (0111), BlockAckReq (1000), BlockAck (1001), PS-Poll (1010), RTS (1011), CTS (1100), Ack (1101), CF-End (1110).

[0152] For example, the data frame includes (QoS) Data, (QoS) Null, etc. defined in conventional WLAN. For the management frame, the value of the type field (B3 and B2) of Fig. 13 is set to 10.

[0153] The MAC frame / signal used in this specification can be identified through the type field / information and subtype field / information described above. For example, “frame” in this specification can mean a MAC frame in which the type bits B3 and B2 bits in the frame control field of the MAC header are set to 01, and the subtype bits B7, B6, B5, and B4 bits in the frame control field are set to 0010. Various MAC frames described in this specification are inserted / included in the data fields of various PPDUs (e.g., HE / VHT / HE / EHT / UHR PPDUs).

[0154] FIG. 14 illustrates a modified example of a transmitting device and / or a receiving device of the present specification.

[0155] The devices (e.g., AP STA, non-AP STA) illustrated in FIGS. 1 to 4 may be modified as illustrated in FIG. 14. The transceiver (630) of FIG. 14 may be identical to the transceivers (113, 123) of FIG. 1. The transceiver (630) of FIG. 14 may include a receiver and a transmitter.

[0156] The processor (610) of FIG. 14 may be identical to the processor (111, 121) of FIG. 1. Alternatively, the processor (610) of FIG. 14 may be identical to the processing chip (114, 124) of FIG. 1.

[0157] The memory (150) of FIG. 14 may be the same as the memory (112, 122) of FIG. 1. Alternatively, the memory (150) of FIG. 14 may be a separate external memory different from the memory (112, 122) of FIG. 1.

[0158] Referring to FIG. 14, a power management module (611) manages power to a processor (610) and / or a transceiver (630). A battery (612) supplies power to the power management module (611). A display (613) outputs results processed by the processor (610). A keypad (614) receives input to be used by the processor (610). The keypad (614) may be displayed on the display (613). A SIM card (615) may be an integrated circuit used to securely store an international mobile subscriber identity (IMSI) and an associated key used to identify and authenticate a subscriber in a mobile phone device, such as a mobile phone or computer.

[0159] Referring to FIG. 14, the speaker (640) can output sound-related results processed by the processor (610). The microphone (641) can receive sound-related input to be used by the processor (610).

[0160] 1. Secondary channel

[0161] This specification proposes a secondary channel access process, and first defines the primary channel and secondary channel as follows.

[0162] The primary channel is a common operating channel for all STAs that are members of a BSS, and in a 20MHz, 40MHz, 80MHz, 160MHz, 80+80MHz or 320MHz BSS, the primary channel is the primary 20MHz channel.

[0163] A secondary channel is a channel associated with a primary channel that is used to create a wider channel than the primary channel. In a 40MHz, 80MHz, 160MHz, 80+80MHz, or 320MHz BSS, the secondary channel is a secondary 20MHz channel. The secondary channel may also be referred to as a non-primary channel or a Non-Primary Channel Access (NPCA) primary channel. Additionally, a Secondary Channel Access (SCA) may also be referred to as a Non-Primary Channel Access (NPCA). These terms will be used interchangeably in the following specification.

[0164] 2. How to perform Non-Primary Channel Access (NPCA) or Secondary Channel Access (SCA)

[0165] Currently, 802.11 performs channel access based on the primary channel. That is, an STA can transmit frames, including on an idle secondary channel, only when the primary channel is idle and the back-off counter (BC) reaches 0. To this end, all STAs perform CCA (Clear Channel Assessment) with the primary channel as a priority. Accordingly, the AP announces the primary channel of the BSS and always includes the primary channel to transmit management frames such as beacons and probe response frames. This mechanism is effective for protection because frame exchange between all STAs and the AP is performed without interference. However, on the other hand, it is inefficient from a medium usage perspective because the idle secondary channel cannot be accessed when only the primary channel is BUSY.

[0166] Figure 15 illustrates an example of channel access in an 802.11 wireless LAN system.

[0167] Figure 15 shows channel access based on the primary channel in the 80MHz bandwidth. As shown in Figure 15, the following are referred to in this specification.

[0168] P20: Primary 20MHz Channel

[0169] S20: Secondary 20MHz Channel (when the bandwidth is 40MHz, it refers to the secondary channel of 20MHz excluding P20)

[0170] S40: Secondary 40MHz Channel (when the bandwidth is 80MHz, it refers to the secondary channel of 40MHz excluding P20 / S20)

[0171] S80: Secondary 80MHz Channel (when the bandwidth is 160MHz, it refers to the secondary channel of 80MHz excluding P20 / S20 / S40)

[0172] S160: Secondary 160MHz Channel (when the bandwidth is 320MHz, it refers to the secondary channel of 160MHz excluding P20 / S20 / S40 / S80)

[0173] S320: Secondary 320MHz Channel (when the bandwidth is 640MHz, it refers to the secondary channel of 320MHz excluding P20 / S20 / S40 / S80 / S160)

[0174] If P20 is BUSY due to CCA or NAV (Network Allocation Vector), the BC is not reduced and waits until it becomes IDLE. When BC becomes 0 through this back-off process, the channel status of S20 and S40 is checked (i.e., CCA) and a frame is transmitted. In this example, since S40 is BUSY, the STA transmits a frame corresponding to a 40MHz PPDU through P20 and S20.

[0175] As mentioned above, when P20 is BUSY and S20 and S40 are IDLE, as shown in Fig. 15, the bandwidth corresponding to 60 MHz is wasted, which reduces the efficiency of medium use. Therefore, this specification proposes a method for accessing a secondary channel when P20 is BUSY. In addition, this specification proposes a method for resolving a misalignment issue in which a transmitting STA transmits a frame in a situation in which a receiving STA cannot perform a channel switch due to different channel switch times when switching from P20 to S20 or from S20 to P20 between an STA and an AP.

[0176] The references (names) in this specification may change, and STA may include AP STA or non-AP STA.

[0177] 2.2 Secondary channel access method

[0178] 2.2.1 STA Capabilities for Secondary Channel Access

[0179] Capabilities for Secondary Channel Access (SCA) can be defined. For example, STAs and APs can communicate to each other whether they support / enable SCA capabilities. SCA capabilities can be determined primarily by Type 1 CCA (referred to as preamble detection (PD)), which identifies Wi-Fi frames performed on the Primary Channel (PCH), i.e., whether frames can be decoded on the Secondary Channel (SCH). This allows NAVs to be set on the SCH as well.

[0180] - Level 0: No Back-off on SCH: SCH performs the second type of CCA as before. That is, it performs CCA that can detect Wi-Fi signals (referred to as guard interval detection (GID)), CCA that detects signals above a certain strength (referred to as energy detection (ED)), etc.

[0181] - Level 1: Back-off on a SCH at a time: PD, a Type 1 CCA, is performed on only one secondary channel at a time (i.e., CCA performed on multiple SCHs simultaneously is not possible).

[0182] - Level 2: Back-off on SCHs at the same time: PD, a Type 1 CCA, is performed on more than one secondary channel simultaneously (i.e., CCA can be performed on multiple SCHs simultaneously).

[0183] These Capabilities can be included in UHR capabilities IEs, etc. For example, from the AP perspective, information about these capabilities can be transmitted in Beacon, Probe Response frame, (Re)Association Request frame, etc., and from the non-AP STA perspective, information about these capabilities can be included in Probe Request frame, (Re)Association Request frame, etc.

[0184] 2.2.2 Basic Procedure of Secondary Channel Access

[0185] For the aforementioned STA, two NAVs can be set: a Basic NAV and an intra-BSS NAV. The Basic NAV can be updated based on a PPDU identified as inter-BSS, or based on a PPDU that cannot be identified as inter-BSS or intra-BSS. The Intra-BSS NAV can be updated based on a PPDU identified as intra-BSS.

[0186] Basically, if STA has Intra-BSS NAV set in PCH, the following situation may occur:

[0187] - When an AP exchanges frames with an STA within the TXOP it has acquired, the intra-BSS NAV is set for other STAs based on the primary channel. At this time, if an STA with an intra-BSS NAV set accesses the SCH and transmits a frame to the AP, the AP will not receive it (i.e., a frame on the SCH transmitted from the STA to the AP) when the AP transmits (e.g., DL Data, Ack, etc.).

[0188] Therefore, STA can perform SCA when the PCH has a Basic NAV set from a BSS other than its own BSS (i.e., OBSS).

[0189] That is, STA can perform SCA when Basic NAV is set in PCH.

[0190] To enable APs and STAs to utilize the SCH based on their surroundings, the AP must announce whether it will allow SCA and the channels that allow SCA. The AP may include at least one of the following pieces of information regarding Secondary Channel Access Operation. This information may be included in the UHR Operation IE or in a new IE format in the Management frame, including the AP's Beacon and Probe Response.

[0191] - Secondary Channel Access Allowed: Indicates whether to allow SCA.

[0192] => Eg, if the above field has 1 bit, a value of '1' indicates that SCA is allowed, and a value of '0' indicates that SCA is not allowed.

[0193] - Secondary Channel Access Bandwidths: The maximum PPDU bandwidth that can be transmitted when performing SCA.

[0194] => Eg, 20 / 40 / 80 / 160 / 320MHz Bandwidth (additionally, 640MHz Bandwidth may be available)

[0195] => This bandwidth must not be greater than the BSS's Operating Bandwidth. Here, the BSS Operating Bandwidth (or the BSS Operating channel's Bandwidth) refers to the bandwidth that the BSS operates. This is announced by the AP via a Beacon or Probe Response frame. For example, if the BSS Operating Bandwidth in Fig. 16 is 160MHz and one or more SCHs in S80 are IDLE, but the Max PPDU Bandwidth announced by the AP is 80MHz, S80 is not included in the frame in Fig. 16 and is transmitted in the form of an 80MHz PPDU.

[0196] - Secondary Channel Access Channel: Secondary Channel that serves as a reference when performing SCA (i.e., the channel where back-off is performed)

[0197] => Eg, Bitmaps can be used. For example, in the case of Fig. 16, since back-off is performed based on the first secondary channel, assuming a bandwidth of 80MHz, and each bit based on a 20MHz channel, three bitmaps can be set to 100. (If there are four bitmaps including the PCH, they can be set to 0100.)

[0198] => Each bit of a bitmap can have the following correlation with a channel:

[0199] From the first bit to the last bit, it can be indicated from the lowest frequency 20MHz channel to the highest frequency 20MHz channel, or vice versa.

[0200] Additionally or alternatively, after STAs associate with the AP, the AP may update the Secondary Channel Access Channel. This may be transmitted in a Beacon, or a new Action frame (referred to herein as the SCH Switch Announcement frame, which is subject to change) may be defined for this purpose in 802.11bn. This frame may be transmitted with at least one of the following fields:

[0201] - SCH Switch Count: Indicates how many TBTTs after which a switch will be made to a newly announced SCH.

[0202] For example, if the SCH Switch Count value has an 8-bit value, a value of 0 can indicate that a switch will occur at some point after the field is transmitted. A value of 1 can indicate that a switch will occur at the next TBTT.

[0203] - SCH Switch Mode: Indicates restriction information that prevents frame exchange through a specific SCA until the SCH is actually switched.

[0204] For example, if the SCH Switch Mode value has an 8-bit value and is set to 1, frame exchange through SCA can be prohibited until a switch to a new SCH actually occurs.

[0205] - Secondary Channel CCA Threshold: This is the threshold used to determine whether a channel is IDLE or BUSY through CCA on one or more SCHs where SCA is performed. In other words, if power measured exceeds this threshold, the channel is considered BUSY. The lower this value, the higher the likelihood that a channel will be considered BUSY even at low power levels.

[0206] => For example, the threshold may be determined as a fixed / reference value (e.g., -82dbm, -72dbm). Additionally or alternatively, the threshold may be determined as a value that adds a variable value (e.g., 4dbm, 8dbm) to this fixed value. In this case, only the variable value may be transmitted.

[0207] => This Threshold can be applied to Type 1 CCA or Type 2 CCA.

[0208] Figure 16 illustrates an example of the basic procedure of SCA.

[0209] Figure 16 illustrates the basic SCA process. If the Basic NAV is set while the STA is performing a backoff at P20, the backoff is performed at S20 at the time the NAV is set. (Switching delay for the PD from P20 to S20 may occur for the PD to S20.) This is a difference in the CCA method in that the CCA can be performed at S20, and can be performed at all levels. The reason for performing a backoff at S20 is that if a neighboring STA with the same or similar operation channel as this STA does not perform a backoff and is in an idle state and transmits a frame at the same time, a collision may occur, which may waste the channel.

[0210] When performing SCA, considerations include:

[0211] i) Frame transmission method

[0212] Previously, when the backoff counter reached 0 through backoff on P20, frames could be transmitted through P20 and one or more idle SCHs based on whether one or more SCHs were idle or busy. Therefore, SCA requires a change to account for the BUSY state of P20, and the backoff operation for this is as follows.

[0213] - STA can perform back-off on one or more SCHs when P20 is BUSY.

[0214] => The reason why back-off is performed on the SCH is that if a neighboring STA that has the same or similar operation channel as a specific STA does not perform back-off on a channel that includes / overlaps with the SCH of the specific STA and is determined to be IDLE as a result of CCA for a short period of time (e.g., 1 slot), and the specific STA and the neighboring STA transmit frames at the same time, a collision may occur, which may result in channel waste.

[0215] => If the remaining NAV timer in the current PCH (P20) is not enough time to catch the TXOP in the SCH, Back-off may not be performed in the SCH.

[0216] - When the back-off counter becomes 0, the STA can perform a second type of CCA for other SCH(s) other than the one or more SCHs that performed the back-off. For example, the STA can perform CCA for other SCH(s) other than the SCH that performed the back-off during a certain period of time (e.g., PIFS) before the back-off counter becomes 0 for the SCH that performed the back-off, to determine whether the channel is IDLE or BUSY.

[0217] - Based on the CCA result, the STA transmits a frame on a channel that includes one or more SCHs that are IDLE and one or more SCHs that have performed back-off.

[0218] For example, in the example of FIG. 16, a back-off is being performed at S20, and when the back-off counter reaches 0, both 20MHz channels of S40 are in an IDLE state. Therefore, in this case, an 80MHz PPDU (including a MAC Frame) including a signaling that P20 has been punctured can be transmitted.

[0219] ii) How to set TXOP

[0220] Since CCA must be performed for P20 by default when Basic NAV expires in P20, the end time of TXOP in SCH is set to end before the time when Basic NAV expires.

[0221] => If TXOP is set to end after the time when Basic NAV expires, there is a problem that STAs cannot receive frames because Legacy STAs, etc. can transmit frames through P20 after the Basic NAV set for the STA. In addition, if the target beacon transmission time (TBTT) is set in the middle of the Basic NAV, problems may occur because the AP must prepare to transmit the Beacon immediately after the Basic NAV, and non-AP STAs also have a problem that they cannot receive the Beacon that the AP should transmit in time and wait for more time than the scheduled time. Therefore, normal frame exchange can be performed in P20 through the condition of 'Set TXOP so that the end time of TXOP ends before the time when Basic NAV expires.'

[0222] => If there is not enough time to catch the TXOP, the frame is not transmitted. In other words, if it is difficult to catch the TXOP for the interval between the point when the Back-off counter (BC) in the SCH becomes 0 and the point when the Basic NAV in the PCH ends, the frame is not transmitted.

[0223] For example, as in the example of Fig. 16, when performing a back-off at S20, the back-off counter becomes 0 and the TXOP is caught, the end is made earlier than the point at which the Basic NAV ends.

[0224] Furthermore, to achieve higher SCA performance, STAs performing SCA should switch to S20 as soon as possible after acquiring information to perform SCA, and should switch to S20 as simultaneously as possible. This allows STAs performing SCA to secure longer TXOPs in S20, and by initiating the switch at the same time as much as possible, it can prevent unnecessary FE initiation during FE (Frame Exchange) in S20.

[0225] The point in time at which the switch is initiated can be defined differently depending on the type of PPDU. Basically, to perform SCA, STAs must obtain information such as 1) whether the received traffic is an OBSS PPDU and 2) how long the SCA will be performed (TXOP information or PPDU Length information). The point in time at which this information can be obtained varies depending on the PPDU type (Non-HT, HT, VHT, HE, EHT, or UHR PPDU), and starting the switch as soon as possible after obtaining the information has a great impact on the performance of SCA.

[0226] Therefore, the AP can announce information on whether to obtain the information required for SCA based on the PHY Header or the MAC Header, or whether to use TXOP or PPDU Length as the duration for performing SCA. In addition, since performing SCA does not provide sufficient FE if the TXOP or PPDU length is too short, the AP needs to announce information such as the threshold value (TXOP Duration Threshold or PPDU Length Threshold) for performing SCA to obtain TXOP at least. The AP can include at least one of the following information for Secondary Channel Access Operation. This information can be included in the UHR Operation IE or in a new IE form in the Management frame including the AP's Beacon and Probe Response.

[0227] - PHY / MAC based NPCA: An indicator indicating whether to switch by obtaining information required for SCA based on PHY Header or by obtaining information required for SCA based on MAC Header.

[0228] For example, when the above field has a 2-bit value, if the value is set to 0, STAs switch by obtaining the information required for SCA based on the PHY Header, and if the value is set to 1, STAs switch by obtaining the information required for SCA based on the MAC Header.

[0229] Obtaining the information required for SCA based on the PHY Header has the advantage of allowing SCA to be performed at a faster time, thus securing a longer TXOP in the SCH.

[0230] On the other hand, when obtaining the information required for SCA based on the MAC Header, there is an advantage in that SCA can be performed for more OBSS PPDU types, since the PHY Header may not contain sufficient information required to perform SCA depending on the PPDU type.

[0231] For example, when PHY / MAC based NPCA is set to 2, the time at which information required for SCA can be obtained varies depending on the PPDU format of the OBSS traffic, and the time at which information required for SCA can be obtained can be determined together with the TXOP / PPDU based NPCA field. For example, when the TXOP based NPCA field is 0 (based on the TXOP value), for non-HT, HT, and VHT OBSS PPDUs, TXOP information is obtained from the MAC header and then SCA is performed, and for HE, EHT, and UHR OBSS PPDUs, TXOP information is obtained from the PHY header and then SCA is performed. When the TXOP based NPCA field is 1 (based on the PPDU Length value), for non-HT, HT OBSS PPDU, the RA (Receiver Address) / TA (Transmitter Address) address that can be used to determine whether it is an OBSS PPDU from the MAC header is checked and SCA is performed for the length of L-SIG. For VHT OBSS PPDU, it is determined whether it is an OBSS PPDU based on the Group ID and Partial AID of the PHY header and SCA is performed for the length of L-SIG. For HE, EHT, UHR OBSS PPDU, it is determined whether it is an OBSS PPDU based on the BSS color of the PHY header and SCA is performed for the length of L-SIG.

[0232] - TXOP / PPDU based NPCA: An indicator indicating whether to set the duration for which SCA can be performed to the TXOP value or the PPDU Length value.

[0233] For example, when the above field has a 2-bit value, if the value is 0, the SCA duration is set based on the TXOP value, and if the value is 1, the SCA duration is set based on the PPDU Length value.

[0234] When performing TXOP-based NPCA, there is an advantage in that the duration for performing SCA is longer because the TXOP value is generally longer than the PPDU Length when performing SCA.

[0235] On the other hand, when performing PPDU Length NPCA, there is an advantage in that the issue of medium synchronization loss in the PCH does not occur when returning from the SCH to the PCH after performing SCA.

[0236] - TXOP Duration Threshold: When the value of the TXOP / PPDU based NPCA defined above is 0, that is, when performing SCA based on the TXOP value, it means the minimum TXOP duration that must be guaranteed. In other words, if the TXOP value (Basic NAV) of the OBSS PPDU is smaller than the value, SCA is not performed even if the PCH is BUSY.

[0237] For example, the unit of the above TXOP duration can be expressed in ms, and when the above field has an 8-bit value, if it is 0000 0011, the TXOP Duration Threshold becomes 3 ms, and SCA is performed only when the Basic NAV is longer than 3 ms.

[0238] Additionally or alternatively, the unit of the field can be us and the number of bits can also be changed.

[0239] - PPDU Length Threshold: When the value of the TXOP / PPDU based NPCA defined above is 1, that is, when performing SCA based on the PPDU Length value, it means the minimum TXOP duration that must be guaranteed. In other words, if the Length value of the OBSS PPDU is smaller than the value, SCA is not performed even if the PCH is BUSY. The Length value of the PPDU can be determined through the LENGTH field of the L-SIG field.

[0240] For example, the unit of the above TXOP duration can be expressed in ms, and when the above field has an 8-bit value, if it is 0000 0011, the PPDU Length Threshold becomes 3 ms, and SCA is performed only when the Length of the OBSS PPDU is longer than 3 ms.

[0241] Additionally or alternatively, the unit of the field can be us and the number of bits can also be changed.

[0242] Additionally or alternatively, the TXOP Duration / PPDU Length Threshold may be announced as a single, unified Threshold instead of being announced individually.

[0243] For example, STAs can perform SCA for the following cases:

[0244] 1) If OBSS PPDU Length < Unified Threshold && OBSS TXOP Duration < Unified Threshold, SCA is not performed.

[0245] 2) If OBSS PPDU Length > Unified Threshold && OBSS TXOP Duration < Unified Threshold, PPDU based NPCA is performed.

[0246] 3) OBSS PPDU Length < Unified Threshold && OBSS TXOP Duration > If it is the unified threshold, TXOP Duration based NPCA is performed.

[0247] 4) If OBSS PPDU Length > Unified Threshold && OBSS TXOP Duration > Unified Threshold, perform TXOP Duration based NPCA.

[0248] <SCA에 대한 STA의 동작과정 #1>

[0249] - Here, STA can be a non-AP STA or an AP.

[0250] In the present disclosure, an STA performing SCA may transmit frames / PPDUs on an SCH even during the time when a NAV is set on the PCH. For example, the STA may transmit frames (or PPDUs) excluding (or punctured) the PCH on one or more SCHs in an IDLE state, as determined by the backoff performed on one or more SCHs and the CCA results of one or more SCHs for which backoff has not been performed.

[0251] Additionally or alternatively, a TXOP initiated by transmission of a frame or PPDU on the SCH may be configured to end before the NAV on the PCH ends. The TXOP length may be configured / indicated via the duration / ID field of the corresponding frame. For example, the value of the duration / ID field may be set to a value representing the time required for the exchange of a frame or PPDU following the corresponding frame or PPDU (including the interframe gap (IFS)).

[0252] Additionally or alternatively, the EDCA Parameter Set for each SCH on which back-off is performed may be set to the EDCA Parameter Set in the PCH, the MU EDCA Parameter Set, or a new EDCA Parameter Set. This EDCA Parameter Set may be applied equally or differently to all SCHs.

[0253] In the present disclosure, an STA receiving a frame transmitted via SCA can perform frame detection on the SCH even during the time when the NAV is set in the PCH. For example, the STA may perform backoff on the SCH because there is a frame to be transmitted, or may attempt to receive a frame addressed to itself on the SCA even when there is no frame to be transmitted. In addition, the STA may perform NAV setting / resetting based on the value of the duration / ID field of the frame detected on the SCH.

[0254] Additionally or alternatively, the EDCA Parameter Set for each SCH on which back-off is performed may be set to the EDCA Parameter Set in the PCH, the MU EDCA Parameter Set, or a new EDCA Parameter Set. This EDCA Parameter Set may be applied equally or differently to all SCHs.

[0255] Figure 17 shows the basic Secondary Channel Access operation process of STA.

[0256] Referring to Figure 17, the transmission process of STA is as follows.

[0257] When an STA receives a PPDU containing a frame from another BSS, the (Basic) NAV is set on the Primary channel. The STA performs a backoff on one or more 20MHz Secondary channels. If the backoff counter reaches 0 on the Secondary channel on which the STA performed the backoff, it performs CCA on the other Secondary channels. The STA transmits the PPDU containing the frame using a bandwidth that includes the Secondary channel on which it performed the backoff and other Secondary channels that are IDLE as a result of performing the CCA.

[0258] Referring to Figure 17, the STA's receiving process is as follows.

[0259] When an STA receives a PPDU containing a frame from another BSS, a (Basic) NAV is set on the Primary channel. The STA performs a Back-off on one or more 20MHz Secondary channels. While performing a Back-off, the STA receives a PPDU containing one or more frames and determines whether the frame is addressed to the STA (i.e., determines whether the Receiver address of the frame is the MAC address of the STA). If the frame is addressed to the STA, the STA decodes the Frame body of the frame. If the frame is not addressed to the STA, the STA sets the NAV to the value of the Duration field of the MAC header of the frame.

[0260] Meanwhile, the following issues occur when transmitting / receiving frames for SCA.

[0261] # Issue: A situation may arise where successful frame exchange is not possible due to differences in channel switch times between AP and STA.

[0262] The AP announces a 20MHz channel on which it will perform backoff within the BSS Operating Bandwidth it operates.

[0263] - SCH Out of Operating Channel Width: An indicator of whether a non-AP STA can perform back-off by switching to an SCH located outside its Operating Channel Width.

[0264] The above field can only be indicated when the SCH performing the backoff announced by the AP is outside its Operating Channel Width.

[0265] For example, let's assume that the BSS Operating Bandwidth is 160MHz and there is a non-AP STA operating with an Operating Channel Width of 80MHz. In this case, when the AP announces the SCH to perform backoff as a 20MHz channel included in S80 (outside the Operating Channel Width of the non-AP STA), if the non-AP STA can switch to the SCH and perform backoff, the above field can be set to 1, and if not, the above field can be set to 0.

[0266] The above field can be included in the Management frame including the Probe Request and Association Request from the non-AP STA perspective as a UHR Capabilities IE or a new IE and directed to the AP.

[0267] Through the above field, when the AP switches to the SCH, it can determine whether a non-AP STA has switched to the SCH.

[0268] Figure 18 illustrates an example of an issue regarding the difference in switch time between AP and STA.

[0269] - switchTimeAP and switchTimeSTA in Fig. 18 are the times that occur when AP and STA switch channels from P20 to S20, respectively.

[0270] => Each time can be indicated by a value with a certain unit (e.g., 32us, 64us).

[0271] => Additionally or alternatively, the Time may vary for each SCH on which Back-off is performed.

[0272] => Additionally or alternatively, the value set in switchTimeSTA may vary depending on the SCH Out of Operating Channel Width defined above.

[0273] => Additionally or alternatively, if the Basic NAV does not have enough time to perform SCA, considering the TXOP Duration Threshold or PPDU Length Threshold value and the channel switch delay (switchTimeAP or switchTimeSTA), the switch to SCH may not be performed. For example, a switching rule can be defined so that the switch to SCH is performed only when the Basic NAV - channel switch delay value is equal to or greater than the TXOP Duration Threshold or PPDU Length Threshold value.

[0274] For example, if the SCH announced by the AP is within the Operating Channel Width of the STA, SCH Out of Operating Channel Width may not exist, and in this case, the STA may have a switchTimeSTA value of 0 or a relatively small value. On the other hand, if the SCH announced by the AP is outside the Operating Channel Width of the STA, the STA may set the SCH Out of Operating Channel Width value to 1 (if it can go) or 0 (if it cannot go) depending on whether it can go outside its Operating Channel Width. If the SCH Out of Operating Channel Width value is 1, the STA's switchTimeSTA will have a relatively large value (because the delay in preparing to perform hardware switching and backoff on a new SCH outside its Operating Channel Width is large). If the SCH Out of Operating Channel Width value is set to 0 to instruct the AP, the STA cannot perform secondary channel access, and the AP that receives the information will not perform SCA with the STA. That is, a non-AP STA may have a different switchTimeSTA value depending on the location of the SCH where the AP will perform backoff and the SCH Out of Operating Channel Width.

[0275] => Additionally or alternatively, regardless of the SCH Out of Operating Channel value, it can report the delay that occurs when switching within its Operating Channel Width and the delay that occurs when switching outside its Operating Channel Width.

[0276] => Additionally or alternatively, as the STA's Operating Mode changes, the SCH may change whether it exists within or outside its operating channel width. In this case, when the STA changes its Operating Mode (e.g., Channel Width), the corresponding channel switch delay can be updated and reported. This information can be included in the Control Information subfield of the OM Control subfield.

[0277] => Additionally or alternatively, switch time may also occur when switching channels from S20 to P20.

[0278] - TXOP through SCA in S20 must be terminated before the Basic NAV set in P20 is terminated and the channel switch to P20 must be completed.

[0279] => Additionally or alternatively, if the channel switch time from P20 to S20 and the channel switch time from S20 to P20 are different, the STA and AP may announce their respective channel switch times.

[0280] - Additionally or alternatively, to reduce signaling overhead, the STA and AP may announce the longer value of the two (max(channel switch time from P20=>S20, channel switch time from S20=>P20)).

[0281] In an environment where the aforementioned delay occurs, when the TX STA and the RX STA perform SCA through back-off at S20 due to the NAV set at P20, a misalignment issue may occur due to a difference in the channel switch times between the TX STA and the RX STA, which may result in a failure in frame exchange. Fig. 18 shows an example. The AP, which is a TX STA, can perform back-off by switching to S20 to perform SCA because the NAV is set at P20, and transmit an RTS to the RX STA. On the other hand, the STA, which is a RX STA, may not successfully perform frame exchange through S20 even if the TX STA transmits an RTS because the channel switch time from P20 to S20 has not yet been completed when the back-off counter value of the AP, which is a TX STA, is 0. Therefore, in this situation, each frame may not be received because the channel switch time between the TX STA and the RX STA may be different. To address the above issue, the AP or STA can set a timer based on the switchTimeAP or switchTimeSTA value.

[0282] The steps to resolve the above issue are as follows:

[0283] - Each Timer can be defined. In this specification, the timer that operates on the TX STA side that transmits the frame is referred to as SwitchTimer.

[0284] => Additionally or alternatively, the SwitchTimer can be set based on switchTimeAP or switchTimeSTA on the RX STA side. For example, in FIG. 18, since the TX STA is an AP and the channel switch time of the STA, which is an RX STA, is longer than the channel switch time of the AP, the AP, which is a TX STA, can set the timer based on swtichTimeSTA.

[0285] => Additionally or alternatively, an AP to which multiple STAs are connected can set SwitchTimer to the value of switchTimeSTA with the maximum value among the switchTimeSTAs of multiple STAs.

[0286] - AP can announce information about switchTimeAP by including it in management frames such as Beacon or Probe response frame or (Re)Association response frame.

[0287] - STA can announce information about switchTimeSTA by including it in a management frame such as a Probe request frame or (Re)Association request frame.

[0288] Solution #1) Wait after back-off method: If the SwitchTimer has not expired when the back-off counter value on the TX STA side becomes 0, the TX STA can wait until the SwitchTimer expires before transmitting the frame instead of transmitting it immediately. (Figure 19)

[0289] Solution #1-2) Wait before back-off method: Before the TX STA starts back-off, the RX STA starts back-off after completing the switch.

[0290] Solution #2) Back-off Reset Method: If the back-off counter value on the TX STA reaches 0 and the SwitchTimer has not yet expired, the TX STA can set a new back-off counter value. At this time, the CW value can be reduced to provide the STA with more opportunities for channel access. (Figure 20)

[0291] Solution #3) BC value setting range adjustment method: If the switch time of the RX STA is longer, the AP or STA can set the BC value of the TX STA to a higher value other than 0, rather than setting it from [0, CW]. For example, if the difference between the switch time of the TX STA and the switch time of the RX STA is 80us (the switch time of the RX STA is longer) and the TX STA draws the BC from [0, CW], a BC value shorter than the switch time may be set, which may cause transmission failure because the switch of the RX STA is not completed even when the BC becomes 0. Therefore, the BC value can be set in a range that is at least larger than the difference in switch times. For example, assuming the difference in switch time is 80us and the slot time is 9us, the BC value can be determined not from [0, CW] but from [9, CW] (9 is round(80 / 9)). At this time, if the CW value is greater than or equal to 9, it can be set as is, and if it is less than 9, the CW value can be updated to the closest CW value that is greater than or equal to 9 according to the existing rule.

[0292] Figure 19 shows an example of the Wait after back-off method (solution #1).

[0293] Figure 19 is an example of a Wait after back-off method to resolve issues that may arise due to differences in channel switch times between an AP and a STA. When Basic NAV is set on P20 of an AP and a STA and a channel switch is performed to S20 to perform SCA, the channel switch time of the AP, which is a TX STA, is shorter, which may cause frame exchange to fail. The AP announces switchTimeAP, which is the time it takes for the AP to switch from P20 to S20, through a beacon, and the STA announces switchTimeSTA, which is the channel switch time of the STA from P20 to S20, through an Association Request Frame. At this time, the AP, which is a TX STA, has a shorter switch time than the RX STA, which may cause frame exchange to fail. Therefore, the AP sets SwitchTimer based on the switchTimeSTA value. Based on this, when the back-off counter value of the AP becomes 0, if the SwitchTimer has not expired, it can operate by waiting until the SwitchTimer expires and then transmitting an RTS (Request to Send). This can resolve the misalignment issue that occurs due to the difference in switch time between AP and STA when SCA is performed.

[0294] Figure 20 illustrates an example of a back-off reset scheme (solution #2).

[0295] Figure 20 is an example of a back-off reset method to resolve issues that may arise due to differences in channel switch times between an AP and a STA. When Basic NAV is set on P20 of an AP and a STA and a channel switch is made to S20 to perform SCA, the AP's channel switch time may be shorter, resulting in frame exchange failure. The AP announces switchTimeAP, which is the time it takes for the AP to switch from P20 to S20, through a beacon, and the STA announces switchTimeSTA, which is the STA's channel switch time from P20 to S20, through an Association Request Frame. At this time, the AP, which is a TX STA, has a shorter switch time than the RX STA, resulting in frame exchange failure. Therefore, the AP sets SwitchTimer based on the switchTimeSTA value. Based on this, when the AP's back-off counter value becomes 0, if the SwitchTimer has not expired, the AP can set a new back-off counter value, and if the reset back-off counter value becomes 0, it can operate by transmitting an RTS. This can resolve the misalignment issue that occurs due to the difference in switch time between AP and STA when SCA is performed.

[0296] <SCA에 대한 STA의 동작과정 #2>

[0297] - STA can be a non-AP STA or an AP.

[0298] In the present disclosure, an STA performing SCA may transmit a frame / PPDU on an SCH even during the time when a NAV is set on the PCH. For example, the STA may transmit a frame or PPDU excluding (or puncturing) the PCH on one or more SCHs in an IDLE state, as determined by the backoff performed on one or more SCHs and the CCA results of one or more SCHs on which the backoff is not performed.

[0299] Additionally or alternatively, a TXOP initiated by transmitting a frame or PPDU on the SCH may be configured to end before the NAV on the PCH ends. The TXOP length may be configured / indicated via the duration / ID field of the corresponding frame. For example, the value of the duration / ID field may be set to a value representing the time required for the exchange of a frame or PPDU following the corresponding frame or PPDU (including the interframe gap (IFS)).

[0300] Additionally or alternatively, the EDCA Parameter Set for each SCH on which back-off is performed may be set to the EDCA Parameter Set in the PCH, the MU EDCA Parameter Set, or a new EDCA Parameter Set. This EDCA Parameter Set may be applied equally or differently to all SCHs.

[0301] Additionally or alternatively, the maximum number of times a frame / PPDU can be transmitted on the SCH can be obtained from the Management frame (e.g., Beacon) transmitted by the AP. If the STA performing SCA is an AP, it can utilize the information transmitted by itself (information on the maximum number of times a frame / PPDU can be transmitted).

[0302] => Additionally or alternatively, the maximum number of times a frame / PPDU can be transmitted may be determined through negotiation between the AP and the STA.

[0303] => Additionally or alternatively, if the number of times an STA has transmitted a frame / PPDU reaches the maximum number of times it can transmit a frame / PPDU, it may then wait for a frame addressed to the STA or a frame not addressed to the STA, i.e. a frame for which NAV can be set.

[0304] => Additionally or alternatively, if the number of times the STA has transmitted a frame / PPDU reaches the maximum number of times it can transmit a frame / PPDU, the STA may perform a back-off by stopping the SCA and switching back to the PCH.

[0305] => Additionally or alternatively, if the number of times the STA has transmitted a frame / PPDU reaches the maximum number of times it can transmit a frame / PPDU, back-off may be performed continuously thereafter.

[0306] Additionally or alternatively, assuming that the AP and the STA know each other's channel switch time by announcing it through Management frames (e.g., Beacon, Probe Request / Response frames), if the channel switch time of the RX STA is longer than the channel switch time of the TX STA, the TX STA can set a timer based on the channel switch time of the RX STA.

[0307] Additionally or alternatively, if the TX STA is an AP, the timer value can be set based on the STA with the longest channel switch time among multiple RX STAs.

[0308] The timer starts operating when the TX STA switches from PCH to SCH, and if the back-off counter value becomes 0 before the timer expires, the frame is transmitted after waiting until the timer expires.

[0309] => Additionally or alternatively, if the Back-off counter value becomes 0 before the timer expires, you can use a method to reset the Back-off counter value until the timer expires.

[0310] => Additionally or alternatively, the TX STA may set a range such that, instead of setting the BC value in [0, CW], it can set the BC value in a range at least greater than the difference in switch times.

[0311] In the present disclosure, an STA receiving a frame transmitted via SCA can perform frame detection on the SCH even during the time when the NAV is set in the PCH. For example, the STA may perform backoff on the SCH because there is a frame to be transmitted, or even when there is no frame to be transmitted, the STA may attempt to receive a frame addressed to itself on the SCA. In addition, the STA may perform NAV setting / resetting based on the value of the duration / ID field of the frame detected on the SCH.

[0312] Additionally or alternatively, the EDCA Parameter Set for each SCH on which back-off is performed may be set to the EDCA Parameter Set in the PCH, the MU EDCA Parameter Set, or a new EDCA Parameter Set. This EDCA Parameter Set may be applied equally or differently to all SCHs.

[0313] The PPDU in which the signal of this specification is transmitted / received may include a data field.

[0314] The above data field contains user data and may contain packets for upper layers, i.e., may contain MPDU (MAC Frame).

[0315] For example, the duration / ID field in the MAC header included in the MPDU may be set to a value including the time length of the frame exchange following the frame or PPDU transmitted excluding (or puncturing) the PCH when supporting channel access operation on the secondary channel. For example, the TXOP end time determined based on the value of the duration / ID field may be set before the end time of the NAV set on the primary channel.

[0316] Additionally, as shown in the above drawing 1, the transmitting device and the receiving device may each include a memory, a processor, and a transceiver.

[0317] The above memory can store information regarding a plurality of Secondary Channel Accesses described herein.

[0318] The processor can perform back-off in the secondary channel based on the information stored in the memory, generate various RUs, and configure PPDUs. The processor can be configured as described in this specification.<SCA에 대한 STA의 동작과정 #1> ,<SCA에 대한 STA의 동작과정 #2> It can be set to do all / some.

[0319] In particular, the transceiver (113) of the transmitting device includes an antenna and can perform analog signal processing. Specifically, the processor (111) can control the transceiver (113) to transmit a PPDU generated by the processor (111).

[0320] Alternatively, the processor (111) may generate a transmission PPDU and store information about the transmission PPDU in the memory (112).

[0321] For example, the processor (111) of the transmitting device may be configured to perform the operations of the transmitting STA according to the examples of the present disclosure. For example, the processor (111) may be configured to transmit a frame on the SCH through the transceiver (113) during a time period in which a NAV is set on the PCH. For example, the processor (111) may be configured to perform a backoff on the SCH through the transceiver (113) and determine one or more SCHs in an IDLE state. For example, the processor (111) may be configured to transmit a frame / PPDU with the PCH excluded / punctured through the transceiver (113) on one or more SCHs. Additionally or alternatively, the processor (111) may be configured to generate a frame including a duration / ID field set to a value such that a TXOP starting with a frame / PPDU transmission on the SCH ends before the time point at which the NAV on the PCH ends.

[0322] Additionally, the transceiver (123) of the receiving device can receive a PPDU based on the control of the processor (121). For example, the transceiver (123) can include a plurality of detailed units (not shown). For example, the transceiver (123) can include at least one receiving antenna and a filter for the corresponding receiving antenna.

[0323] A PPDU received through a transceiver (123) may be stored in a memory (122). A processor (121) may process decoding of the received PPDU through the memory (122). The processor (121) may obtain control information (e.g., SIG) regarding BW / Tone-Plan / RU included in the PPDU and store the obtained control information in the memory (122).

[0324] The processor (121) can perform decoding on the received PPDU. In addition, the processor (121) can process the decoded data. For example, the processor (121) can perform a processing operation to transmit information about the decoded data field to a higher layer (e.g., MAC layer). In addition, if the generation of a signal is instructed from the higher layer to the PHY layer in response to the data transmitted to the higher layer, a subsequent operation can be performed.

[0325] For example, the processor parses a MAC PDU obtained through PHY decoding of the DATA field of a PPDU received through a transceiver.

[0326] For example, the processor (121) of the receiving device may be configured to perform the operations of the receiving STA according to the examples of the present disclosure. For example, the processor (121) may attempt to detect a frame on the SCH via the transceiver (123) during the time for which the NAV is set on the PCH. The processor (121) may be configured to decode / parse a frame addressed to it based on a frame received on the SCH. Additionally, the processor (121) may be configured to set / reset the NAV based on the value of the duration / ID field of a frame not addressed to it.

[0327] Fig. 21 is a flowchart illustrating the operation of a transmitting device according to the present embodiment.

[0328] An example of FIG. 21 may be performed at a transmitting STA or transmitting device (AP and / or non-AP STA).

[0329] Some of the steps (or detailed sub-steps described below) in the example of Fig. 21 may be omitted or changed.

[0330] Through step S2110, the transmitting device (transmitting STA) can obtain information regarding the aforementioned Tone Plan. As described above, the information regarding the Tone Plan includes the size and location of the RU, control information related to the RU, information regarding the frequency band in which the RU is included, information regarding the STA receiving the RU, etc.

[0331] Through step S2120, the transmitting device can configure / generate a PPDU based on the acquired control information. The step of configuring / generating the PPDU may include a step of configuring / generating each field of the PPDU. That is, step S2120 may include a step of configuring an EHT-SIG field including control information regarding a Tone Plan. That is, step S2120 may include a step of configuring a field including control information indicating the size / position of the RU (e.g., an N bitmap) and / or a step of configuring a field including an identifier (e.g., an AID) of an STA receiving the RU.

[0332] Additionally, step S2120 may include a step of generating an STF / LTF sequence to be transmitted through a specific RU. The STF / LTF sequence may be generated based on a preset STF generation sequence / LTF generation sequence.

[0333] Additionally, step S2120 may include a step of generating a data field (i.e., MPDU) to be transmitted via a specific RU.

[0334] The transmitting device can transmit the PPDU configured through step S2120 to the receiving device based on step S2130.

[0335] While performing step S2130, the transmitting device may perform at least one of operations such as CSD, Spatial Mapping, IDFT / IFFT operation, and GI insertion.

[0336] A signal / field / sequence configured according to this specification can be transmitted in the form of FIG. 5.

[0337] Fig. 22 is a flowchart illustrating the operation of a receiving device according to the present embodiment.

[0338] The above-described PPDU can be received according to an example of FIG. 22.

[0339] An example of FIG. 22 may be performed at a receiving STA or receiving device (AP and / or non-AP STA).

[0340] Some of the steps (or detailed sub-steps described below) in the example of Fig. 22 may be omitted.

[0341] A receiving device (receiving STA) may receive all or part of a PPDU through step S2210. The received signal may have the form of FIG. 5.

[0342] The sub-step of step S2210 can be determined based on step S2130 of Fig. 21. That is, step S2210 can perform an operation to restore the results of the CSD, Spatial Mapping, IDFT / IFFT operations, and GI insert operations applied in step S2130.

[0343] At step S2220, the receiving device can decode all or part of the PPDU. Additionally, the receiving device can obtain control information related to the Tone Plan (i.e., RU) from the decoded PPDU.

[0344] More specifically, the receiving device can decode the L-SIG and EHT-SIG of the PPDU based on the Legacy STF / LTF and obtain information included in the L-SIG and EHT SIG fields. Information regarding various Tone Plans (i.e., RUs) described herein can be included in the EHT-SIG, and the receiving STA can obtain information regarding the Tone Plan (i.e., RU) through the EHT-SIG.

[0345] In step S2230, the receiving device can decode the remaining portion of the PPDU based on the information about the Tone Plan (i.e., RU) acquired through step S2220. For example, the receiving STA can decode the STF / LTF field of the PPDU based on the information about one Plan (i.e., RU). In addition, the receiving STA can decode the data field of the PPDU based on the information about the Tone Plan (i.e., RU) and acquire the MPDU included in the data field.

[0346] Additionally, the receiving device may perform a processing operation to transmit the decoded data to a higher layer (e.g., MAC layer) through step S2230. Furthermore, if the generation of a signal is instructed from the higher layer to the PHY layer in response to the data transmitted to the higher layer, a subsequent operation may be performed.

[0347] Hereinafter, the above-described embodiment will be described with reference to FIGS. 1 to 22.

[0348] FIG. 23 is a flowchart illustrating a procedure in which a transmitting STA accesses a non-primary channel and receives a PPDU according to the present embodiment.

[0349] An example of FIG. 23 can be performed in a network environment that supports a next-generation wireless LAN system (UHR (Ultra High Reliability) wireless LAN system or next wi-fi). The next-generation wireless LAN system is a wireless LAN system that improves on the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0350] An example of FIG. 23 is performed at a transmitting STA, which may correspond to an access point (AP). The receiving STA of FIG. 23 may correspond to at least one STA (station).

[0351] The present embodiment proposes a method for determining whether to perform channel access to a non-primary channel by transmitting information necessary for performing channel access to the non-primary channel through a management frame. Specifically, the present embodiment proposes a method for obtaining information necessary for channel access to the non-primary channel based on a PHY header or MAC header through the management frame, or for obtaining information regarding a section in which channel access to the non-primary channel can be performed.

[0352] In step S2310, the transmitting STA (station) transmits a management frame to the receiving STA.

[0353] In step S2320, the transmitting STA determines whether to perform channel access by switching from the primary 20 MHz channel to the first non-primary channel based on the management frame.

[0354] The above management frame includes first and second information.

[0355] The above first information is information on whether information required for channel access to the first non-primary channel is acquired based on a PHY (Physical) header or a MAC (Medium Access Control) header.

[0356] The above second information is information on whether the interval for performing channel access for the first non-primary channel is set to TXOP (transmission opportunity) or PPDU length.

[0357] For example, based on the first information being set to 0, information required for channel access to the first non-primary channel can be obtained based on the PHY header. Based on the first information being set to 1, information required for channel access to the first non-primary channel can be obtained based on the MAC header.

[0358] For example, when information required for channel access to the first non-primary channel is obtained based on the PHY header, channel access to the first non-primary channel can be performed at a faster time, which has the advantage of securing a longer TXOP for performing channel access to the first non-primary channel. On the other hand, when information required for channel access to the first non-primary channel is obtained based on the MAC header, the PHY header may not contain sufficient information required for performing channel access according to the type of OBSS PPDU described below, which has the advantage of allowing channel access to the first non-primary channel for more types of OBSS PPDU.

[0359] For example, based on the second information being set to 0, the interval during which channel access to the first non-primary channel can be performed can be set to the TXOP. Based on the second information being set to 1, the interval during which channel access to the first non-primary channel can be performed can be set to the PPDU length.

[0360] At this time, the TXOP may be a TXOP of an OBSS (Overlapping Basic Service Set) PPDU (Physical Protocol Data Unit). The PPDU length may be the length of the OBSS PPDU.

[0361] Based on the first information being set to 2, information required for channel access to the first non-primary channel can be obtained based on the PHY header or the MAC header depending on the type of the OBSS PPDU.

[0362] For example, when the type of the OBSS PPDU is a non-HT (non-High Throughput) OBSS PPDU, an HT OBSS PPDU, or a VHT (Very High Throughput) OBSS PPDU based on the first information being set to 2 and the second information being set to 0, the TXOP may be obtained based on the MAC header. When the type of the OBSS PPDU is a HE (High Efficiency) OBSS PPDU, an EHT (Extremely High Throughput) OBSS PPDU, or an UHR (Ultra High Reliability) OBSS PPDU, the TXOP may be obtained based on the PHY header.

[0363] As another example, based on the first information being set to 2 and the second information being set to 1, whether the type of the OBSS PPDU is the non-HT OBSS PPDU or the HT OBSS PPDU is determined based on the MAC header, and channel access to the first non-primary channel can be performed for a length of the L-SIG (Legacy-SIG) of the OBSS PPDU. Whether the type of the OBSS PPDU is the VHT OBSS PPDU is determined based on the group ID (Identifier) ​​or partial ID of the PHY header, and channel access to the first non-primary channel can be performed for a length of the L-SIG of the OBSS PPDU. Whether the type of the OBSS PPDU is the HE OBSS PPDU, the EHT OBSS PPDU, or the UHR OBSS PPDU is determined based on the BSS (Basic Service Set) color of the PHY header, and channel access to the first non-primary channel can be performed for the length of the L-SIG of the OBSS PPDU.

[0364] That is, the present embodiment proposes a method for transmitting information necessary for performing channel access to a non-primary channel via a management frame. This can have the effect of preventing unnecessary switching of an AP or STA from a primary channel to the non-primary channel, thereby preventing waste of medium, or can have the effect of enabling the AP or STA to switch to the non-primary channel at an earlier point in time to obtain a longer TXOP after switching.

[0365] The above management frame may further include third information.

[0366] The third information may be information on a threshold value of a TXOP or PPDU length that must be guaranteed at least to perform channel access for the first non-primary channel.

[0367] Based on the interval in which channel access to the first non-primary channel can be performed being set to the TXOP, if the TXOP is less than the threshold, the transmitting STA (or the receiving STA) may determine not to perform channel access to the first non-primary channel. Conversely, if the TXOP is greater than or equal to the threshold, the transmitting STA (or the receiving STA) may determine to perform channel access to the first non-primary channel.

[0368] If the interval for performing channel access to the first non-primary channel is set to the PPDU length, and the PPDU length is less than the threshold, the transmitting STA (or the receiving STA) may determine not to perform channel access to the first non-primary channel. Conversely, if the PPDU length is greater than or equal to the threshold, the transmitting STA (or the receiving STA) may determine to perform channel access to the first non-primary channel.

[0369] The threshold value of the TXOP or PPDU length may be a single integrated value. For example, if the single integrated value is greater than the TXOP and greater than the PPDU length, the transmitting STA (or the receiving STA) may determine not to perform channel access to the first non-primary channel. If the single integrated value is greater than the TXOP and less than the PPDU length, the transmitting STA (or the receiving STA) may determine to perform channel access to the first non-primary channel during the PPDU length. If the single integrated value is less than the TXOP and greater than the PPDU length, the transmitting STA (or the receiving STA) may determine to perform channel access to the first non-primary channel during the TXOP. If the single integrated value is less than the TXOP and less than the PPDU length, the transmitting STA (or the receiving STA) may determine to perform channel access to the first non-primary channel during the TXOP.

[0370] The above management frame may further include fourth information.

[0371] The fourth information may be information on whether channel access can be performed on a first non-primary channel located outside the operating channel width of the receiving STA.

[0372] The management frame may further include information about a first switch time that occurs when the transmitting STA switches from the primary 20 MHz channel to the first non-primary channel for channel access and information about a second switch time that occurs when the receiving STA switches from the primary 20 MHz channel to the first non-primary channel for channel access.

[0373] The information about the first and second switch times may have different values ​​set based on the fourth information.

[0374] The value for the channel switch delay can be determined based on the first and second switch times.

[0375] If the length of the TXOP or the PPDU is greater than or equal to a value obtained by subtracting a value for the channel switch delay from the Basic NAV (Network Allocation Vector) due to the OBSS PPDU, the transmitting STA (or the receiving STA) may determine to perform channel access for the first non-primary channel.

[0376] The above management frame may be a beacon, a probe response frame, or a (re)association response frame.

[0377] The transmitting STA (or the receiving STA) may perform backoff for the first non-primary channel. The transmitting STA (or the receiving STA) may perform channel access for the second non-primary channel when the backoff value for the first non-primary channel is 0. The transmitting STA (or the receiving STA) may transmit or receive a PPDU (Physical Protocol Data Unit) through an idle channel among the first and second non-primary channels.

[0378] The first non-primary channel may be a secondary 20MHz channel capable of performing the backoff while the Basic NAV is set on the primary 20MHz channel. The second non-primary channel may be a secondary channel other than the first non-primary channel in the BSS (Basic Service Set) operating channel.

[0379] FIG. 24 is a flowchart illustrating a procedure in which a receiving STA accesses a non-primary channel and transmits a PPDU according to the present embodiment.

[0380] An example of FIG. 24 can be performed in a network environment that supports a next-generation wireless LAN system (UHR (Ultra High Reliability) wireless LAN system or next wi-fi). The next-generation wireless LAN system is a wireless LAN system that improves on the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0381] An example of FIG. 24 is performed at a receiving STA, which may correspond to at least one STA (station). The transmitting STA of FIG. 24 may correspond to an AP (access point).

[0382] The present embodiment proposes a method for determining whether to perform channel access to a non-primary channel by transmitting information necessary for performing channel access to the non-primary channel through a management frame. Specifically, the present embodiment proposes a method for obtaining information necessary for channel access to the non-primary channel based on a PHY header or MAC header through the management frame, or for obtaining information regarding a section in which channel access to the non-primary channel can be performed.

[0383] In step S2410, the receiving STA (station) receives a management frame from the transmitting STA.

[0384] In step S2420, the receiving STA determines whether to perform channel access by switching from the primary 20 MHz channel to the first non-primary channel based on the management frame.

[0385] The above management frame includes first and second information.

[0386] The above first information is information on whether information required for channel access to the first non-primary channel is acquired based on a PHY (Physical) header or a MAC (Medium Access Control) header.

[0387] The above second information is information on whether the interval for performing channel access for the first non-primary channel is set to TXOP (transmission opportunity) or PPDU length.

[0388] For example, based on the first information being set to 0, information required for channel access to the first non-primary channel can be obtained based on the PHY header. Based on the first information being set to 1, information required for channel access to the first non-primary channel can be obtained based on the MAC header.

[0389] For example, when information required for channel access to the first non-primary channel is obtained based on the PHY header, channel access to the first non-primary channel can be performed at a faster time, which has the advantage of securing a longer TXOP for performing channel access to the first non-primary channel. On the other hand, when information required for channel access to the first non-primary channel is obtained based on the MAC header, the PHY header may not contain sufficient information required for performing channel access according to the type of OBSS PPDU described below, which has the advantage of allowing channel access to the first non-primary channel for more types of OBSS PPDU.

[0390] For example, based on the second information being set to 0, the interval during which channel access to the first non-primary channel can be performed can be set to the TXOP. Based on the second information being set to 1, the interval during which channel access to the first non-primary channel can be performed can be set to the PPDU length.

[0391] At this time, the TXOP may be a TXOP of an OBSS (Overlapping Basic Service Set) PPDU (Physical Protocol Data Unit). The PPDU length may be the length of the OBSS PPDU.

[0392] Based on the first information being set to 2, information required for channel access to the first non-primary channel can be obtained based on the PHY header or the MAC header depending on the type of the OBSS PPDU.

[0393] For example, when the type of the OBSS PPDU is a non-HT (non-High Throughput) OBSS PPDU, an HT OBSS PPDU, or a VHT (Very High Throughput) OBSS PPDU based on the first information being set to 2 and the second information being set to 0, the TXOP may be obtained based on the MAC header. When the type of the OBSS PPDU is a HE (High Efficiency) OBSS PPDU, an EHT (Extremely High Throughput) OBSS PPDU, or an UHR (Ultra High Reliability) OBSS PPDU, the TXOP may be obtained based on the PHY header.

[0394] As another example, based on the first information being set to 2 and the second information being set to 1, whether the type of the OBSS PPDU is the non-HT OBSS PPDU or the HT OBSS PPDU is determined based on the MAC header, and channel access to the first non-primary channel can be performed for a length of the L-SIG (Legacy-SIG) of the OBSS PPDU. Whether the type of the OBSS PPDU is the VHT OBSS PPDU is determined based on the group ID (Identifier) ​​or partial ID of the PHY header, and channel access to the first non-primary channel can be performed for a length of the L-SIG of the OBSS PPDU. Whether the type of the OBSS PPDU is the HE OBSS PPDU, the EHT OBSS PPDU, or the UHR OBSS PPDU is determined based on the BSS (Basic Service Set) color of the PHY header, and channel access to the first non-primary channel can be performed for the length of the L-SIG of the OBSS PPDU.

[0395] That is, the present embodiment proposes a method for transmitting information necessary for performing channel access to a non-primary channel via a management frame. This can have the effect of preventing unnecessary switching of an AP or STA from a primary channel to the non-primary channel, thereby preventing waste of medium, or can have the effect of enabling the AP or STA to switch to the non-primary channel at an earlier point in time to obtain a longer TXOP after switching.

[0396] The above management frame may further include third information.

[0397] The third information may be information on a threshold value of a TXOP or PPDU length that must be guaranteed at least to perform channel access for the first non-primary channel.

[0398] Based on the interval in which channel access to the first non-primary channel can be performed being set to the TXOP, if the TXOP is less than the threshold, the transmitting STA (or the receiving STA) may determine not to perform channel access to the first non-primary channel. Conversely, if the TXOP is greater than or equal to the threshold, the transmitting STA (or the receiving STA) may determine to perform channel access to the first non-primary channel.

[0399] If the interval for performing channel access to the first non-primary channel is set to the PPDU length, and the PPDU length is less than the threshold, the transmitting STA (or the receiving STA) may determine not to perform channel access to the first non-primary channel. Conversely, if the PPDU length is greater than or equal to the threshold, the transmitting STA (or the receiving STA) may determine to perform channel access to the first non-primary channel.

[0400] The threshold value of the TXOP or PPDU length may be a single integrated value. For example, if the single integrated value is greater than the TXOP and greater than the PPDU length, the transmitting STA (or the receiving STA) may determine not to perform channel access to the first non-primary channel. If the single integrated value is greater than the TXOP and less than the PPDU length, the transmitting STA (or the receiving STA) may determine to perform channel access to the first non-primary channel during the PPDU length. If the single integrated value is less than the TXOP and greater than the PPDU length, the transmitting STA (or the receiving STA) may determine to perform channel access to the first non-primary channel during the TXOP. If the single integrated value is less than the TXOP and less than the PPDU length, the transmitting STA (or the receiving STA) may determine to perform channel access to the first non-primary channel during the TXOP.

[0401] The above management frame may further include fourth information.

[0402] The fourth information may be information on whether channel access can be performed on a first non-primary channel located outside the operating channel width of the receiving STA.

[0403] The management frame may further include information about a first switch time that occurs when the transmitting STA switches from the primary 20 MHz channel to the first non-primary channel for channel access and information about a second switch time that occurs when the receiving STA switches from the primary 20 MHz channel to the first non-primary channel for channel access.

[0404] The information about the first and second switch times may have different values ​​set based on the fourth information.

[0405] The value for the channel switch delay can be determined based on the first and second switch times.

[0406] If the length of the TXOP or the PPDU is greater than or equal to a value obtained by subtracting a value for the channel switch delay from the Basic NAV (Network Allocation Vector) due to the OBSS PPDU, the transmitting STA (or the receiving STA) may determine to perform channel access for the first non-primary channel.

[0407] The above management frame may be a beacon, a probe response frame, or a (re)association response frame.

[0408] The transmitting STA (or the receiving STA) may perform backoff for the first non-primary channel. The transmitting STA (or the receiving STA) may perform channel access for the second non-primary channel when the backoff value for the first non-primary channel is 0. The transmitting STA (or the receiving STA) may transmit or receive a PPDU (Physical Protocol Data Unit) through an idle channel among the first and second non-primary channels.

[0409] The first non-primary channel may be a secondary 20MHz channel capable of performing the backoff while the Basic NAV is set on the primary 20MHz channel. The second non-primary channel may be a secondary channel other than the first non-primary channel in the BSS (Basic Service Set) operating channel.

[0410] <Device Configuration>

[0411] The technical features of the present specification described above can be applied to various devices and methods. For example, the technical features of the present specification described above can be performed / supported by the devices of FIG. 1 and / or FIG. 14. For example, the technical features of the present specification described above can be applied only to a part of FIG. 1 and / or FIG. 14. For example, the technical features of the present specification described above can be implemented based on the processing chip (114, 124) of FIG. 1, or based on the processor (111, 121) and memory (112, 122) of FIG. 1, or based on the processor (610) and memory (620) of FIG. 14. For example, the device of the present specification receives a management frame from a transmitting STA (station); and determines whether to perform channel access by switching from a primary 20 MHz channel to a first non-primary channel based on the management frame.

[0412] The technical features of this specification can be implemented based on a computer-readable medium (CRM). For example, the CRM proposed by this specification is at least one computer-readable recording medium containing instructions that are executed by at least one processor.

[0413] The CRM may store instructions for performing operations including: receiving a management frame from a transmitting STA (station); and determining whether to perform channel access by switching from a primary 20 MHz channel to a first non-primary channel based on the management frame. The instructions stored in the CRM of the present specification may be executed by at least one processor. At least one processor related to the CRM of the present specification may be the processor (111, 121) or the processing chip (114, 124) of FIG. 1, or the processor (610) of FIG. 14. Meanwhile, the CRM of the present specification may be the memory (112, 122) of FIG. 1, the memory (620) of FIG. 14, or a separate external memory / storage medium / disk, etc.

[0414] The technical features of this specification described above are applicable to various applications and business models. For example, the technical features described above can be applied to wireless communication in devices that support artificial intelligence (AI).

[0415] Artificial intelligence (AI) is the study of artificial intelligence or the methodologies for creating it, while machine learning (ML) defines various problems in the field of AI and studies the methodologies for solving them. Machine learning is also defined as an algorithm that improves performance on a task through consistent experience.

[0416] An artificial neural network (ANN) is a model used in machine learning. It can refer to a model with problem-solving capabilities, consisting of artificial neurons (nodes) formed by the connection of synapses to form a network. An ANN can be defined by the connection patterns between neurons in different layers, the learning process that updates model parameters, and the activation function that generates output values.

[0417] An artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer contains one or more neurons, and the artificial neural network may include synapses connecting neurons. In an artificial neural network, each neuron can output a function value of an activation function based on input signals, weights, and biases received through the synapses.

[0418] Model parameters are parameters determined through learning, including synaptic connection weights and neuron biases. Hyperparameters are parameters that must be set before learning in machine learning algorithms, including the learning rate, number of iterations, mini-batch size, and initialization function.

[0419] The goal of artificial neural network training can be seen as determining model parameters that minimize a loss function. The loss function can be used as an indicator for determining optimal model parameters during the artificial neural network training process.

[0420] Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning depending on the learning method.

[0421] Supervised learning refers to a method for training an artificial neural network when given labels for the training data. The labels can refer to the correct answer (or output value) that the artificial neural network must infer when the training data is input to the artificial neural network. Unsupervised learning can refer to a method for training an artificial neural network when the training data is not given labels. Reinforcement learning can refer to a learning method in which an agent defined within a given environment is trained to select actions or action sequences that maximize the cumulative reward in each state.

[0422] Machine learning implemented with a deep neural network (DNN) containing multiple hidden layers among artificial neural networks is also called deep learning, and deep learning is a subset of machine learning. Hereinafter, the term "machine learning" is used to encompass deep learning.

[0423] Additionally, the above-described technical features can be applied to wireless communication of robots.

[0424] A robot can be defined as a machine that automatically performs or operates a given task based on its own capabilities. Specifically, a robot capable of perceiving its environment, making independent judgments, and performing actions can be called an intelligent robot.

[0425] Robots can be categorized into industrial, medical, household, and military applications based on their intended use or field. Robots are equipped with actuators or motors, enabling them to perform various physical actions, such as moving robot joints. Furthermore, mobile robots incorporate wheels, brakes, and propellers into their actuators, enabling them to move on the ground or fly in the air.

[0426] Additionally, the above-described technical features can be applied to devices that support extended reality.

[0427] Extended reality is a general term for virtual reality (VR), augmented reality (AR), and mixed reality (MR). VR technology presents real-world objects and backgrounds as CG images only, AR technology presents virtual CG images over images of real objects, and MR technology is a computer graphics technology that blends and combines virtual objects with the real world.

[0428] MR technology is similar to AR in that it presents both real and virtual objects simultaneously. However, while AR uses virtual objects to complement real objects, MR uses virtual and real objects on an equal footing.

[0429] XR technology can be applied to HMD (Head-Mount Display), HUD (Head-Up Display), mobile phones, tablet PCs, laptops, desktops, TVs, digital signage, etc., and devices to which XR technology is applied can be called XR devices.

[0430] The claims set forth in this specification may be combined in various ways. For example, the technical features of the method claims of this specification may be combined and implemented as a device, and the technical features of the device claims of this specification may be combined and implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a device, and the technical features of the method claims and the technical features of the device claims of this specification may be combined and implemented as a method.

Claims

In wireless LAN systems, A step in which a receiving STA (station) receives a management frame from a transmitting STA; and The receiving STA comprises a step of determining whether to perform channel access by switching from a primary 20MHz channel to a first non-primary channel based on the management frame, The above management frame includes first and second information, The above first information is information on whether information required for channel access to the first non-primary channel is acquired based on a PHY (Physical) header or a MAC (Medium Access Control) header, and The second information is information on whether the interval for performing channel access for the first non-primary channel is set to TXOP (transmission opportunity) or PPDU length. method. In the first paragraph, Based on the above second information being set to 0, the section in which channel access for the first non-primary channel can be performed is set to the TXOP, Based on the second information being set to 1, the interval for performing channel access to the first non-primary channel is set to the PPDU length, The above TXOP is the TXOP of the OBSS (Overlapping Basic Service Set) PPDU (Physical Protocol Data Unit), The above PPDU length is the length of the above OBSS PPDU. method. In the second paragraph, Based on the above first information being set to 0, information required for channel access to the first non-primary channel is obtained based on the PHY header, Based on the first information being set to 1, information required for channel access to the first non-primary channel is obtained based on the MAC header, Based on the above first information being set to 2, information required for channel access to the first non-primary channel is obtained based on the PHY header or the MAC header depending on the type of the OBSS PPDU. method. In the third paragraph, Based on the above first information being set to 2 and the above second information being set to 0, If the type of the above OBSS PPDU is a non-HT (non-High Throughput) OBSS PPDU, an HT OBSS PPDU, or a VHT (Very High Throughput) OBSS PPDU, the TXOP is obtained based on the MAC header, If the type of the above OBSS PPDU is HE (High Efficiency) OBSS PPDU, EHT (Extremely High Throughput) OBSS PPDU or UHR (Ultra High Reliability) OBSS PPDU, the TXOP is obtained based on the PHY header. method. In the third paragraph, Based on the above first information being set to 2 and the above second information being set to 1, Whether the type of the above OBSS PPDU is the non-HT OBSS PPDU or the HT OBSS PPDU is determined based on the MAC header, and channel access to the first non-primary channel is performed for the length of the L-SIG (Legacy-SIG) of the above OBSS PPDU, Whether the type of the above OBSS PPDU is the VHT OBSS PPDU is determined based on the group ID (Identifier) ​​or partial ID of the PHY header, and channel access to the first non-primary channel is performed for the length of the L-SIG of the above OBSS PPDU. Whether the type of the above OBSS PPDU is the HE OBSS PPDU, the EHT OBSS PPDU or the UHR OBSS PPDU is determined based on the BSS (Basic Service Set) color of the PHY header, and channel access to the first non-primary channel is performed for the length of the L-SIG of the OBSS PPDU. method. In the first paragraph, The above management frame further includes third information, The third information is information about a threshold value of a TXOP or PPDU length that must be guaranteed at least to perform channel access to the first non-primary channel. A step of determining, based on the interval in which channel access for the first non-primary channel can be performed, that the receiving STA does not perform channel access for the first non-primary channel when the TXOP is smaller than the threshold; and The method further includes a step of determining, by the receiving STA, not to perform channel access to the first non-primary channel when the interval for performing channel access to the first non-primary channel is set to the PPDU length and the PPDU length is less than the threshold value. method. In the first paragraph, The above management frame further includes fourth information, The fourth information is information on whether channel access can be performed on a first non-primary channel located outside the operating channel width of the receiving STA. method. In the first paragraph, The management frame further includes information about a first switch time that occurs when the transmitting STA switches from the primary 20MHz channel to the first non-primary channel for channel access and information about a second switch time that occurs when the receiving STA switches from the primary 20MHz channel to the first non-primary channel for channel access. The value for the channel switch delay is determined based on the first and second switch times, If the length of the TXOP or the PPDU is greater than or equal to a value obtained by subtracting a value for the channel switch delay from the Basic NAV (Network Allocation Vector) due to the OBSS PPDU, the receiving STA further includes a step of determining to perform channel access for the first non-primary channel. method. In paragraph 8, The receiving STA performs a backoff for the first non-primary channel; The receiving STA performs channel access for a second non-primary channel when the backoff value for the first non-primary channel is 0; and The receiving STA further includes a step of transmitting or receiving a PPDU through an IDLE channel among the first and second non-primary channels, The above first non-primary channel is a secondary 20MHz channel that can perform the backoff while the Basic NAV is set on the primary 20MHz channel, The above second non-primary channel is a secondary channel excluding the first non-primary channel in the BSS operating channel. method. In a wireless LAN system, a receiving STA (station) memory; transceiver; and A processor operatively coupled to the memory and the transceiver, the processor comprising: Receive a management frame from a transmitting STA; and Based on the above management frame, it is determined whether to perform channel access by switching from the primary 20MHz channel to the first non-primary channel. The above management frame includes first and second information, The above first information is information on whether information required for channel access to the first non-primary channel is acquired based on a PHY (Physical) header or a MAC (Medium Access Control) header, and The second information is information on whether the interval for performing channel access for the first non-primary channel is set to TXOP (transmission opportunity) or PPDU length. Receiving STA. In wireless LAN systems, A step in which a transmitting STA (station) transmits a management frame to a receiving STA; and The above transmitting STA comprises a step of determining whether to perform channel access by switching from the primary 20MHz channel to the first non-primary channel based on the management frame, The above management frame includes first and second information, The above first information is information on whether information required for channel access to the first non-primary channel is acquired based on a PHY (Physical) header or a MAC (Medium Access Control) header, and The second information is information on whether the interval for performing channel access for the first non-primary channel is set to TXOP (transmission opportunity) or PPDU length. method. In Article 11, Based on the above second information being set to 0, the section in which channel access for the first non-primary channel can be performed is set to the TXOP, Based on the second information being set to 1, the interval for performing channel access to the first non-primary channel is set to the PPDU length, The above TXOP is the TXOP of the OBSS (Overlapping Basic Service Set) PPDU (Physical Protocol Data Unit), The above PPDU length is the length of the above OBSS PPDU. method. In paragraph 12, Based on the above first information being set to 0, information required for channel access to the first non-primary channel is obtained based on the PHY header, Based on the first information being set to 1, information required for channel access to the first non-primary channel is obtained based on the MAC header, Based on the above first information being set to 2, information required for channel access to the first non-primary channel is obtained based on the PHY header or the MAC header depending on the type of the OBSS PPDU. method. In Article 13, Based on the above first information being set to 2 and the above second information being set to 0, If the type of the above OBSS PPDU is a non-HT (non-High Throughput) OBSS PPDU, an HT OBSS PPDU, or a VHT (Very High Throughput) OBSS PPDU, the TXOP is obtained based on the MAC header, If the type of the above OBSS PPDU is HE (High Efficiency) OBSS PPDU, EHT (Extremely High Throughput) OBSS PPDU or UHR (Ultra High Reliability) OBSS PPDU, the TXOP is obtained based on the PHY header. method. In Article 13, Based on the above first information being set to 2 and the above second information being set to 1, Whether the type of the above OBSS PPDU is the non-HT OBSS PPDU or the HT OBSS PPDU is determined based on the MAC header, and channel access to the first non-primary channel is performed for the length of the L-SIG (Legacy-SIG) of the above OBSS PPDU, Whether the type of the above OBSS PPDU is the VHT OBSS PPDU is determined based on the group ID (Identifier) ​​or partial ID of the PHY header, and channel access to the first non-primary channel is performed for the length of the L-SIG of the above OBSS PPDU. Whether the type of the above OBSS PPDU is the HE OBSS PPDU, the EHT OBSS PPDU or the UHR OBSS PPDU is determined based on the BSS (Basic Service Set) color of the PHY header, and channel access to the first non-primary channel is performed for the length of the L-SIG of the OBSS PPDU. method. In Article 11, The above management frame further includes third information, The third information is information about a threshold value of a TXOP or PPDU length that must be guaranteed at least to perform channel access to the first non-primary channel. A step of determining, based on the interval in which channel access for the first non-primary channel can be performed, that the transmitting STA does not perform channel access for the first non-primary channel when the TXOP is smaller than the threshold; and The method further includes a step of determining, by the transmitting STA, not to perform channel access to the first non-primary channel when the interval in which channel access to the first non-primary channel can be performed is set to the PPDU length and the PPDU length is smaller than the threshold value. method. In Article 11, The above management frame further includes fourth information, The fourth information is information on whether channel access can be performed on a first non-primary channel located outside the operating channel width of the receiving STA. method. In a wireless LAN system, a transmitting STA (station) memory; transceiver; and A processor operatively coupled to the memory and the transceiver, the processor comprising: Transmit a management frame to the receiving STA; and Based on the above management frame, it is determined whether to perform channel access by switching from the primary 20MHz channel to the first non-primary channel. The above management frame includes first and second information, The above first information is information on whether information required for channel access to the first non-primary channel is acquired based on a PHY (Physical) header or a MAC (Medium Access Control) header, and The second information is information on whether the interval for performing channel access for the first non-primary channel is set to TXOP (transmission opportunity) or PPDU length. Transmitting STA. At least one computer-readable medium containing instructions based on being executed by at least one processor, A step of receiving a management frame from a transmitting STA (station); and Including a step of determining whether to perform channel access by switching from a primary 20MHz channel to a first non-primary channel based on the above management frame, The above management frame includes first and second information, The above first information is information on whether information required for channel access to the first non-primary channel is acquired based on a PHY (Physical) header or a MAC (Medium Access Control) header, and The second information is information on whether the interval for performing channel access for the first non-primary channel is set to TXOP (transmission opportunity) or PPDU length. Recording medium. In a wireless LAN system, for a device, memory; and A processor operatively coupled to the memory, the processor comprising: Receive a management frame from a transmitting STA (station); and Based on the above management frame, it is determined whether to perform channel access by switching from the primary 20MHz channel to the first non-primary channel. The above management frame includes first and second information, The above first information is information on whether information required for channel access to the first non-primary channel is acquired based on a PHY (Physical) header or a MAC (Medium Access Control) header, and The second information is information on whether the interval for performing channel access for the first non-primary channel is set to TXOP (transmission opportunity) or PPDU length. device.

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