Method and device for determining whether to perform NPCA on basis of MU EDCA parameter in wireless LAN system

Abstract

Proposed are a method and device for determining whether to perform an NPCA on the basis of an MU EDCA parameter in a wireless LAN system. Specifically, a first non-AP STA receives a management frame from a first AP. The first non-AP STA determines, on the basis of the management frame, whether to perform a channel access by switching from a primary 20 MHz channel to a non-primary channel. The management frame includes the MU EDCA parameter. The MU EDCA parameter includes information about a contention window, information about an AIFSN, and information about an MU EDCA timer. The channel access to the non-primary channel is not allowed by setting the AIFSN to 0 until the MU EDCA timer expires.

Description

Method and device for determining whether to perform NPCA based on MU EDCA parameters in a wireless LAN system

[0001] The present specification relates to a technique for determining whether to perform NPCA based on MU EDCA parameters in a wireless LAN system, and more specifically, to a method and apparatus for suspending or suspending channel access (or EDCA) for a non-primary channel until the MU EDCA timer expires (in the absence of a separate trigger or ICF transmission) by setting the AIFSN value among the MU EDCA parameters to 0 regardless of the value transmitted in the MU EDCA parameters.

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

[0003] This specification proposes a method and apparatus for determining whether to perform NPCA based on MU EDCA parameters in a wireless LAN system.

[0004] One example of this specification proposes a method for determining whether to perform NPCA based on MU EDCA parameters.

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

[0006] This embodiment proposes a method for determining whether to perform channel access to a non-primary channel based on MU EDCA parameters to resolve the problem that the determination of whether the BSS primary channel is BUSY / IDLE between the AP and the non-AP STA may differ due to hidden node issues, etc. Additionally, this embodiment proposes a method for determining whether to perform channel access to the non-primary channel by having the AP directly transmit information regarding the OBSS AP list or trigger-based NPCA mode to the non-AP STA.

[0007] The first non-AP (non-access point) STA (station) receives a management frame from the first AP.

[0008] The first non-AP STA determines whether to perform channel access by switching from the primary 20 MHz channel to the non-primary channel based on the management frame.

[0009] The above management frame includes MU (Multi User) EDCA (Enhanced Distributed Channel Access) parameters.

[0010] The above MU EDCA parameters include information regarding the contention window, information regarding the Arbitration Inter-Frame Space Number (AIFSN), and information regarding the MU EDCA timer.

[0011] The AIFSN is set to 0 until the MU EDCA timer expires, so that channel access to the non-primary channel is not allowed.

[0012] Information regarding the above-mentioned contention window, information regarding the above-mentioned AIFSN, and information regarding the above-mentioned MU EDCA timer may be defined per AC (Access Category). The above-mentioned AIFSN is a value that determines the length of the waiting time for channel access, but if the above-mentioned AIFSN is 0, EDCA becomes disabled for the corresponding AC, and this disabled state may persist until the above-mentioned MU EDCA timer expires. Information regarding the above-mentioned contention window may include information regarding the minimum or maximum value of the contention window (for the corresponding AC).

[0013] The above MU EDCA timer may be defined as the time to use the above MU EDCA parameter for the corresponding AC. That is, the management frame may further include the EDCA parameter. After the above MU EDCA timer expires, channel access to the non-primary channel may be performed based on the above EDCA parameter (returning to the existing EDCA parameter).

[0014] After switching from the primary 20 MHz channel to the non-primary channel (when NPCA operation begins), the first AP may transmit a basic trigger frame to the first non-AP STA. The first AP may receive a Quality of Service (QoS) frame from the first non-AP STA based on the basic trigger frame. The MU EDCA parameters may be used after receiving the QoS frame. (The first non-AP STA may receive a basic trigger frame from the first AP. The first non-AP STA may transmit a Quality of Service (QoS) frame to the first AP based on the basic trigger frame. The MU EDCA parameters may be used after transmitting the QoS frame.)

[0015] That is, the present embodiment proposes a method for determining whether to perform channel access (or EDCA) for a non-primary channel using MU EDCA parameters when a Non-Primary Channel Access (NPCA) operation starts. Specifically, the present embodiment proposes a method for suspending or suspending channel access (or EDCA) for the non-primary channel until the MU EDCA timer expires by setting the AIFSN value among the MU EDCA parameters to 0 regardless of the value passed in the MU EDCA parameters.

[0016] According to the method proposed in this embodiment, the determination of whether the BSS primary channel is BUSY / IDLE differs between the AP and the non-AP STA, thereby preventing meaningless operations such as the AP performing channel access on the BSS primary channel and the non-AP STA performing channel access on the non-primary channel. In addition, by preventing unnecessary media access and frame transmission attempts by non-AP STAs, performance improvement in terms of power consumption can be expected.

[0017] FIG. 1 shows an example of a transmitting device and / or receiving device of the present specification.

[0018] Figure 2 is a conceptual diagram showing the structure of a wireless LAN (WLAN).

[0019] Figure 3 is a diagram illustrating a general link setup process.

[0020] FIG. 4 illustrates an example of a multi-link (ML).

[0021] FIG. 5 illustrates a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received in an STA of the present specification.

[0022] Figure 6 is a diagram showing the arrangement of resource units (RU) used for a 20 MHz PPDU.

[0023] Figure 7 is a diagram showing the arrangement of resource units (RU) used for a 40 MHz PPDU.

[0024] Figure 8 is a diagram showing the arrangement of resource units (RU) used for an 80 MHz PPDU.

[0025] Figure 9 shows the operation according to UL-MU.

[0026] Figure 10 shows an example of a channel used / supported / defined within the 2.4 GHz band.

[0027] FIG. 11 illustrates an example of a channel used / supported / defined within the 5 GHz band.

[0028] FIG. 12 illustrates an example of a channel used / supported / defined within the 6 GHz band.

[0029] Figure 13 shows an example of a MAC frame header.

[0030] FIG. 14 shows a modified example of a transmitting device and / or receiving device of the present specification.

[0031] FIG. 15 illustrates an example of channel access in an 802.11 wireless LAN system.

[0032] Figure 16 illustrates an example of the basic procedure of SCA.

[0033] Figure 17 illustrates a network topology example and an example in which Basic NAV is configured in the PCH of NPCA STAs.

[0034] Figure 18 illustrates an example of an NPCA AP informing the OBSS AP list.

[0035] FIG. 19 illustrates an example of the MU EDCA Parameter Set element format and the MU AC Parameter Record field format.

[0036] FIG. 20 illustrates an example of EDCA operation using MU EDCA parameters when NPCA operation starts.

[0037] FIG. 21 is a flowchart illustrating the operation of a transmitting device according to the present embodiment.

[0038] FIG. 22 is a flowchart illustrating the operation of a receiving device according to the present embodiment.

[0039] FIG. 23 is a flowchart illustrating a procedure for determining whether an AP according to the present embodiment will perform NPCA based on MU EDCA parameters.

[0040] FIG. 24 is a flowchart illustrating a procedure for determining whether a non-AP STA according to the present embodiment will perform NPCA based on MU EDCA parameters.

[0041] In this specification, “A or B” may mean “only A,” “only B,” or “both A and B.” Alternatively, in this specification, “A or B” may be interpreted as “A and / or B.” For example, in this specification, “A, B or C” may mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

[0042] As used herein, a slash ( / ) or a comma may mean “and / or.” For example, “A / B” may mean “and / or B.” Accordingly, “A / B” may mean “only A,” “only B,” or “both A and B.” For example, “A, B, C” may mean “A, B, or C.”

[0043] In this specification, “at least one of A and B” may 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” may be interpreted as synonymous with “at least one of A and B.”

[0044] Additionally, parentheses used in this specification may mean “for example.” Specifically, when indicated as “control information (UHR-Signal field),” the “UHR-Signal field” may be proposed as an example of “control information.” In other words, the “control information” of this specification is not limited to the “UHR-Signal field,” and the “UHR-Signal field” may be proposed as an example of “control information.” Furthermore, even when indicated as “control information (UHR-Signal field),” the “UHR-Signal field” may be proposed as an example of “control information.”

[0045] Additionally, as used herein, “a / an” may mean “at least one” or “one or more.” Also, terms ending in “(s)” may mean “at least one” or “one or more.”

[0046] Additionally, the expressions “based on,” “on the basis of,” or “according to” as used herein mean “based at least in part on,” and do not mean “based only on one.”

[0047] Technical features described individually within a single drawing in this specification may be implemented individually or simultaneously.

[0048] The following examples of this specification may be applied to various wireless communication systems. For example, the following examples of this specification may be applied to wireless local area network (WLAN) systems. For example, this specification may be applied to IEEE 802.11a / g / n / ac / ax / be / bn standards. In addition, the examples of this specification may be applied to Ultra High Reliability (UHR) standards or next-generation wireless LAN standards that enhance IEEE 802.11bn. In addition, the examples of this specification may be applied to mobile communication systems. For example, they may be applied to mobile communication systems based on Long Term Evolution (LTE) and its evolution based on 3GPP (3rd Generation Partnership Project) standards.

[0049] To explain the technical features of this specification, the technical features to which this specification can be applied are described below.

[0050] FIG. 1 shows an example of a transmitting device and / or receiving device of the present specification.

[0051] 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 this specification may also be referred to by various names such as mobile terminal, wireless device, Wireless Transmit / Receive Unit (WTRU), User Equipment (UE), Mobile Station (MS), Mobile Subscriber Unit, or simply user. The STA (110, 120) of this specification may also be referred to by various names such as network, base station, Node-B, Access Point (AP), repeater, router, relay, etc. The STA (110, 120) of this specification may also be referred to by various names such as receiving apparatus, transmitting device, receiving STA, transmitting STA, receiving device, transmitting device, etc.

[0052] For example, the STA (110, 120) can perform the role of an access point (AP) or a non-AP. That is, the STA (110, 120) of this specification can perform the functions of an AP and / or a non-AP. In this specification, an AP may also be indicated as an AP STA.

[0053] The STA (110, 120) of this specification may support various communication standards other than the IEEE 802.11 standard. For example, it may support communication standards according to 3GPP standards (e.g., LTE, LTE-A, 5G NR standards). In addition, the STA of this specification may be implemented in various devices such as mobile phones, vehicles, and personal computers. Furthermore, the STA of this specification may support communication for various communication services such as voice calls, video calls, data communication, and self-driving.

[0054] In this specification, the STA (110, 120) may include a medium access control (MAC) that complies with the provisions of the IEEE 802.11 standard and a physical layer interface for the wireless medium.

[0055] Based on side drawing (a) of Fig. 1, STA (110, 120) is described as follows.

[0056] The first STA (110) may include a processor (111), 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.

[0057] The transceiver (113) of the first STA performs the operation of transmitting and receiving signals. 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 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 transmitted signal, and perform control for transmitting the signal. The memory (112) of the AP can store the signal received through the transceiver (113) (i.e., the received signal) and the signal to be transmitted through the transceiver (i.e., the transmitted signal).

[0059] For example, the second STA (120) can perform the intended operation of a Non-AP STA. For example, the non-AP transceiver (123) performs the operation of transmitting and receiving signals. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a / b / g / n / ac / ax / be, etc.).

[0060] For example, the processor (121) of the Non-AP STA can receive a signal through the transceiver (123), process the received signal, generate a transmitted signal, and perform control for transmitting the signal. The memory (122) of the Non-AP STA can store the signal received through the transceiver (123) (i.e., the received signal) and can store the signal to be transmitted through the transceiver (i.e., the transmitted signal).

[0061] For example, the operation of the device indicated as AP in the following specification may be performed in the first STA (110) or the second STA (120). For example, if the first STA (110) is the AP, the operation of the device indicated as AP is controlled by the processor (111) of the first STA (110), and related signals may be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (110). Additionally, control information related to the operation of the AP or the transmission / reception signals of the AP may be stored in the memory (112) of the first STA (110). Additionally, if the second STA (110) is the AP, the operation of the device indicated as AP is controlled by the processor (121) of the second STA (120), and related signals 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 AP or the transmission / reception signals of the AP can be stored in the memory (122) of the second STA (110).

[0062] For example, the operation of a device indicated as non-AP (or User-STA) in the following specification may be performed in the STA (110) or the second STA (120). For example, if the second STA (120) is non-AP, the operation of the device indicated as non-AP is controlled by the processor (121) of the second STA (120), and related signals may be transmitted or received through a transceiver (123) controlled by the processor (121) of the second STA (120). Additionally, control information related to the operation of the non-AP or the transmission / reception signals 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 the device marked as non-AP is controlled by the processor (111) of the first STA (110), and the related signal can be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (120). Additionally, control information related to the operation of the non-AP or the transmission / reception signal of the AP can be stored in the memory (112) of the first STA (110).

[0063] In the following specification, a device referred to as (transmission / reception) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmission / reception) Terminal, (transmission / reception) device, (transmission / reception) apparatus, network, etc. may refer to the STA (110, 120) of FIG. 1. For example, a device indicated without specific drawing symbols as (transmission / reception) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmission / reception) Terminal, (transmission / reception) device, (transmission / reception) apparatus, network, etc. may also refer to the STA (110, 120) of FIG. 1. For example, in the following example, the operation of various STAs transmitting and receiving signals (e.g., PPPDU) may be performed by the transceiver (113, 123) of FIG. 1. Additionally, in the following example, 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 to generate a transmission / reception signal or to perform data processing or operations in advance for a transmission / reception signal may include: 1) an operation to determine / acquire / configure / operate / decode / encode bit information of sub-fields (SIG, STF, LTF, Data) included in the PPDU; 2) an operation to determine / configure / acquire time resources or frequency resources (e.g., subcarrier resources) used for sub-fields (SIG, STF, LTF, Data) included in the PPDU; 3) an operation to determine / configure / acquire specific sequences (e.g., pilot sequence, STF / LTF sequence, extra sequence applied to SIG) used for sub-fields (SIG, STF, LTF, Data) included in the PPDU; 4) a power control operation and / or power saving operation applied to the STA; and 5) an operation related to determining / acquiring / configuring / operating / decoding / encoding of an ACK signal. In addition, in the following example, various information (e.g., information related to fields, subfields, control fields, parameters, power, etc.) used by various STAs for determining / acquiring / configuring / calculating / decoding / encoding of transmission and reception signals can be stored in the memory (112, 122) of FIG. 1.

[0064] The device / STA of the aforementioned supplementary drawing (a) of FIG. 1 can be modified as shown in supplementary drawing (b) of FIG. 1. Hereinafter, the STA (110, 120) of this specification will be described based on supplementary drawing (b) of FIG. 1.

[0065] For example, the transceiver (113, 123) shown in side drawing (b) of FIG. 1 can perform the same function as the transceiver shown in side drawing (a) of FIG. 1 described above. For example, the processing chip (114, 124) shown in side 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) shown in side drawing (b) of FIG. 1 can perform the same function as the processor (111, 121) and the memory (112, 122) shown in side drawing (a) of FIG. 1 described above.

[0066] 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, AP (Access Point), 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) shown in side drawings (a) / (b) of FIG. 1, or the processing chip (114, 124) shown in side drawing (b) of FIG. 1. That is, the technical features of the present specification may be performed in the STA (110, 120) shown in side drawings (a) / (b) of FIG. 1, or only in the processing chip (114, 124) shown in side drawing (b) of FIG. 1. For example, the technical feature of the transmitting STA transmitting a control signal may be understood as a technical feature in which a control signal generated in the processor (111, 121) shown in side drawings (a) / (b) of FIG. 1 is transmitted through the transceiver (113, 123) shown in side drawings (a) / (b) of FIG. 1. Alternatively, the technical feature of the transmitting STA transmitting a control signal may be understood as a technical feature in which a control signal to be transmitted from the processing chip (114, 124) shown in side drawing (b) of FIG. 1 is generated to the transceiver (113, 123).

[0067] For example, the technical feature of the receiving STA receiving a control signal can be understood as the technical feature of the control signal being received by the transceiver (113, 123) shown in side view (a) of FIG. 1. Alternatively, the technical feature of the receiving STA receiving a control signal can be understood as the technical feature of the control signal received by the transceiver (113, 123) shown in side view (a) of FIG. 1 being acquired by the processor (111, 121) shown in side view (a) of FIG. 1. Alternatively, the technical feature of the receiving STA receiving a control signal can be understood as the technical feature of the control signal received by the transceiver (113, 123) shown in side view (b) of FIG. 1 being acquired by the processing chip (114, 124) shown in side view (b) of FIG. 1.

[0068] Referring to side view (b) of FIG. 1, software code (115, 125) may be included in 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.

[0069] The processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may include an application-specific integrated circuit (ASIC), other chipsets, logic circuits, and / or data processing devices. 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 a processor enhanced therefrom.

[0070] In this specification, an uplink may refer to a link for communication from a non-AP STA to an AP STA, and uplink PPDUs / packets / signals, etc. may be transmitted through the uplink. Additionally, in this specification, a downlink may refer to a link for communication from an AP STA to a non-AP STA, and downlink PPDUs / packets / signals, etc. may be transmitted through the downlink.

[0071] Figure 2 is a conceptual diagram showing the structure of a wireless LAN (WLAN).

[0072] The top of Figure 2 shows the structure of the IEEE (Institute of Electrical and Electronic Engineers) 802.11 infrastructure BSS (basic service set).

[0073] The top of Figure 2 shows the structure of the IEEE (Institute of Electrical and Electronic Engineers) 802.11 infrastructure BSS (basic service set).

[0074] Referring to the top of FIG. 2, the wireless LAN system may include one or more infrastructure BSSs (200, 205) (hereinafter BSS). The BSS (200, 205) is a set of APs and STAs, such as an AP (access point, 225) and STA1 (Station, 200-1), that can communicate with each other by successfully synchronizing, and is not a concept referring to a specific area. The BSS (205) may include one or more STAs (205-1, 205-2) that can be combined with one AP (230).

[0075] The BSS may include at least one STA, an AP (225, 230) that provides a distribution service, and a distribution system (DS, 210) that connects multiple APs.

[0076] A distributed system (210) can implement an extended service set (ESS, 240) by connecting multiple BSSs (200, 205). The term ESS (240) may be used to refer to a network formed by connecting one or more APs through the distributed system (210). APs included in a single ESS (240) may have the same service set identification (SSID).

[0077] The portal (portal, 220) can act as a bridge to connect a wireless LAN network (IEEE 802.11) with another network (e.g., 802.X).

[0078] In a BSS like the one at the top 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 between STAs and perform communication without APs (225, 230). A network that establishes a network between STAs and performs communication without APs (225, 230) is defined as an ad-hoc network or an independent basic service set (IBSS).

[0079] The bottom of Fig. 2 is a conceptual diagram showing IBSS.

[0080] 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 performs management functions centrally. 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 since access to the distributed system is not allowed, they form a self-contained network.

[0081] Figure 3 is a diagram illustrating a general link setup process.

[0082] In the described S310 step, the STA can perform a network discovery operation. The network discovery operation may include the STA's scanning operation. That is, in order for the STA to access a network, it must find a network it can join. Before joining a wireless network, the STA must identify a compatible network, and the process of identifying networks existing in a specific area is called scanning. Scanning methods include active scanning and passive scanning.

[0083] Figure 3 illustrates a network discovery operation that includes an active scanning process as an example. In active scanning, the STA performing the scanning moves between channels and transmits a probe request frame to search for nearby APs, and waits for a response. The responder transmits a probe response frame as a response to the probe request frame to the STA that transmitted the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame from the BSS of the channel being scanned. In a BSS, the AP becomes the responder because it transmits the beacon frame, whereas in an IBSS, the responder is not constant because STAs within the IBSS take turns transmitting the beacon frame. 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 in the same way (i.e., transmit and receive probe request / response on channel 2).

[0084] Although not shown in the example of Fig. 3, scanning operations may also be performed using a passive scanning method. An STA performing scanning based on passive scanning can wait for a beacon frame while switching between channels. A beacon frame is one of the management frames in IEEE 802.11, which announces the presence of a wireless network and is periodically transmitted to allow a scanning STA to find the wireless network and join it. In a BSS, the AP performs the role of periodically transmitting beacon frames, while in an IBSS, STAs within the IBSS take turns transmitting beacon frames. When a scanning STA receives a beacon frame, it stores the information about the BSS included in the beacon frame and records the beacon frame information in each channel while moving to another channel. An STA that has received a beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform scanning in the next channel in the same manner.

[0085] The STA that discovered the 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 later. The authentication process of S320 may include the STA sending an authentication request frame to the AP, and the AP sending an authentication response frame to the STA in response. The authentication frame used in the authentication request / response corresponds to a management frame.

[0086] The authentication frame may include information regarding the authentication algorithm number, authentication transaction sequence number, status code, challenge text, RSN (Robust Security Network), Finite Cyclic Group, etc.

[0087] The STA can send an authentication request frame to the AP. Based on the information contained in the received authentication request frame, the AP can determine whether to allow authentication for the STA. The AP can provide the result of the authentication process to the STA through an authentication response frame.

[0088] A successfully authenticated STA may perform an association process based on step S330. The association process includes the STA sending an association request frame to the AP, and in response, the AP sending an association response frame to the STA. For example, the association request frame may include information regarding various capabilities, beacon listen interval, service set identifier (SSID), supported rates, supported channels, RSN, mobility domain, supported operating classes, Traffic Indication Map Broadcast request, interworking service capabilities, etc. For example, a connection response frame may include information related to various capabilities, status code, AID (Association ID), support rate, EDCA (Enhanced Distributed Channel Access) parameter set, RCPI (Received Channel Power Indicator), RSNI (Received Signal to Noise Indicator), mobility domain, timeout interval (association comeback time), overlapping BSS scan parameters, TIM broadcast response, QoS map, etc.

[0089] Subsequently, 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 4-way handshake via an EAPOL (Extensible Authentication Protocol over LAN) frame.

[0090] FIG. 4 illustrates an example of a multi-link (ML).

[0091] As illustrated in FIG. 4, multiple multi-link devices (MLDs) can communicate through a multi-link. The MLDs can be classified into an AP MLD containing multiple AP STAs and a non-AP MLD containing multiple non-AP STAs. That is, the AP MLD may include affiliated APs (i.e., AP STAs), and the non-AP MLD may include affiliated STAs (i.e., non-AP STAs, or user-STAs).

[0092] A multilink may include a first link and a second link, and different channels / subchannels / frequency resources may be assigned to the first and second links. The first and second multilinks may be identified by 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 link may be configured in different bands.

[0093] The AP MLD of FIG. 4 includes three affiliated APs. In one 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 one 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. Additionally, in one 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. Additionally, in one 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.

[0094] In one example of FIG. 4, AP1 can initiate a multilink setup procedure (ML setup procedure) by transmitting an Association Request frame to non-AP STA1. In one example of FIG. 4, non-AP STA1 can transmit an Association Response frame in response to the Association Request frame. Each AP (e.g., AP1 / 2 / 3) shown in FIG. 4 may be the same as the AP shown in FIG. 1 and / or FIG. 2, and each non-AP (e.g., non-AP1 / 2 / 3) shown in FIG. 4 may be the same as the STA shown in FIG. 1 and / or FIG. 2 (i.e., user-STA or non-AP STA).

[0095] 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.

[0096] FIG. 5 illustrates a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted / received in an STA of the present specification.

[0097] The STAs of this specification (e.g., AP STA, non-AP STA, AP MLD, non-AP MLD) can transmit and / or receive the PPDU of FIG. 5. The PPDU described in this specification may have the structure of FIG. 5, for example. Additionally, the PPDU described in this specification, the Ultra High Reliability (UHR) PPDU, may be referred to by various names such as transmit PPDU, receive PPDU, first type or N type PPDU. The PPDU described in this specification may be used in WLAN systems defined according to IEEE 802.11bn and / or next-generation WLAN systems that improve upon IEEE 802.11bn.

[0098] 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 SU (single-user) mode / type / transmission, MU (multi-user) mode / type / transmission, and NDP (null data packet) mode / type / transmission related to channel sounding. For example, if the example of FIG. 5 is related to NDP, the illustrated Data field may be omitted. If the PPDU of FIG. 5 is used for TB (Trigger-based) mode, the UHR-SIG of FIG. 5 may be omitted. In other words, an STA that receives a Trigger frame for UL-MU (Uplink-MU) communication may transmit a PPDU in which the UHR-SIG is omitted in the example of FIG. 5.

[0099] In FIG. 5, L-STF to UHR-LTF can be called a preamble or physical preamble and can be generated / transmitted / received / acquired / decoded at the physical layer (included in the transmitting / receiving STA).

[0100] Each block illustrated in FIG. 5 may be referred to as a field / subfield / signal, etc. As illustrated in FIG. 5, the names of these fields / subfields / signals may be 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.

[0101] The subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields in Fig. 5 can be set to 312.5 kHz, and the subcarrier spacing of the UHR-STF, UHR-LTF, and Data fields can 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 can be displayed in units of 312.5 kHz, and the tone index (or subcarrier index) of the UHR-STF, UHR-LTF, and Data fields can be displayed in units of 78.125 kHz.

[0102] The PPDU of Fig. 5, L-LTF and L-STF, may be the same as conventional fields (e.g., non-HT LTF and non-HT STF defined in conventional WLAN standards).

[0103] The L-SIG field of FIG. 5 may contain, 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 contain information regarding 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 a UHR PPDU, the value of the Length field may be determined as a multiple of 3. For example, if the PPDU is an 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, or 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 a UHR PPDU is set to a value satisfying the condition that the remainder is zero when LENGTH is divided by 3.

[0104] For example, a (non-AP and AP) STA can apply BCC encoding based on a code rate of 1 / 2 to 24 bits of information in the L-SIG field. Subsequently, the transmitting STA can obtain 48 bits of BCC encoding. BPSK modulation can be applied to the 48 bits of encoding to generate 48 BPSK symbols. The transmitting STA can map the 48 BPSK symbols to positions excluding the pilot subcarrier {subcarrier indices -21, -7, +7, +21} and the DC subcarrier {subcarrier index 0}. Consequently, 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 of {-1, -1, -1, 1} to the subcarrier index {-28, -27, +27, +28}. The above signal can be used for channel estimation for the frequency domain corresponding to {-28, -27, +27, +28}.

[0105] For example, the (non-AP and AP) STA can generate an RL-SIG that is identical to the L-SIG. BPSK modulation may be applied to the RL-SIG. The receiving (non-AP and AP) STA can determine that the received PPDU is a HE PPDU, EHT PPDU, or UHR PPDU based on the presence of the RL-SIG. In other words, the receiving (non-AP and AP) STA can determine that the received PPDU is one of the HE PPDU, EHT PPDU, or UHR PPDU if the RL-SIG is present. In other words, the receiving (non-AP and AP) STA can determine that the received PPDU is one of the non-HT PPDU, HT PPDU, or VHT PPDU if the RL-SIG is not present. 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.

[0106] After the RL-SIG in Fig. 5, a U-SIG (Universal SIG) may be inserted. The U-SIG may be referred to by various names such as the first SIG field, first SIG, first type SIG, control signal, control signal field, first (type) control signal, common control field, and common control signal.

[0107] U-SIG may contain N bits of information and may contain information to identify the type of EHT PPDU. For example, U-SIG may be constructed based on two symbols (e.g., two consecutive OFDM symbols). Each symbol for U-SIG (e.g., OFDM symbol) may have a duration of 4 us. Each symbol of U-SIG may be used to transmit 26 bits of information. For example, each symbol of U-SIG may be transmitted and received based on 52 data tones and 4 pilot tones.

[0108] For example, A bit information (e.g., 52 un-coded bits) can be transmitted through U-SIG, and the first symbol of U-SIG can transmit the first X bit information (e.g., 26 un-coded bits) of the total A bit information, and the second symbol of U-SIG can transmit the remaining Y bit information (e.g., 26 un-coded bits) of the total A bit information. For example, the transmitting STA can obtain the 26 un-coded bits included in each U-SIG symbol. The transmitting STA can generate 52-coded bits by performing convolutional encoding (i.e., BCC encoding) based on a rate of R=1 / 2 and can perform interleaving on the 52-coded bits. The transmitting STA can generate 52 BPSK symbols assigned to each U-SIG symbol by performing BPSK modulation on the interleaved 52-coded bits. 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. 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.

[0109] For example, A bit information (e.g., 52 un-coded bits) transmitted by U-SIG may include a CRC field (e.g., a field of 4 bits) and a tail field (e.g., a field of 6 bits). The CRC field and the tail field may be transmitted through a second symbol of U-SIG. The CRC field may be generated based on 26 bits assigned to the first symbol of U-SIG and the remaining 16 bits within the second symbol excluding the CRC / tail field, and may be generated based on a conventional CRC calculation algorithm. Additionally, the tail field may be used to terminate the trellis of a convolutional decoder and may be set, for example, to "000000".

[0110] A bit information (e.g., 52 un-coded bits) transmitted by 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 may be assigned only to the first symbol of U-SIG, or the version-independent bits may be assigned to both the first and second symbols of U-SIG. For example, the version-independent bits and the version-dependent bits may be referred to by various names, such as the first control bit and the second control bit.

[0111] For example, the version-independent bits of 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 of the 3-bit PHY version identifier (e.g., a value of 000) may indicate that the transmitted and received PPDU is an EHT PPDU. Additionally, a second value of the 3-bit PHY version identifier (e.g., a value of 001) may indicate that the transmitted and received PPDU is a UHR PPDU.

[0112] In other words, when an (AP / non-AP) STA transmits an EHT PPDU, it can set a 3-bit PHY version identifier to a first value. In other words, a 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 a UHR PPDU based on the PHY version identifier having the second value.

[0113] 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 is related to UL communication, and the second value of the UL / DL flag field is related to DL communication.

[0114] For example, the version-independent bits of U-SIG may include information regarding the length of the TXOP (transmission opportunity) and information regarding the BSS color ID.

[0115] For example, if the UHR PPDU is classified into various types (e.g., type related to SU transmission (performed based on UL or DL), type related to DL transmission, type related to NDP transmission, type related to DL non-MU-MIMO, type related to DL MU-MIMO, type related to Multi-AP operation, type related to CBF (Coordinated beamforming) and SR (Spatial Reuse), type related to C-OFDMA (Coordinated OFDMA), type related to C-TDMA (Coordinated TDMA)), information regarding the type of the EHT PPDU (e.g., 2-bit or 3-bit information) may be included in the version-dependent bits of the U-SIG.

[0116] For example, U-SIG may include: 1) a bandwidth field containing information regarding bandwidth; 2) a field containing information regarding the MCS technique applied to UHR-SIG; 3) an indication field containing information regarding whether the dual subcarrier modulation (DCM) technique is applied to UHR-SIG; 4) a field containing information regarding the number of symbols used for UHR-SIG; 5) a field containing information regarding whether UHR-SIG is generated across the entire band; 6) a field containing information regarding the type of UHR-LTF / STF; and 7) information regarding a field indicating the length of UHR-LTF and CP length.

[0117] Preamble puncturing may be applied to the PPDU of Fig. 5. Preamble puncturing means applying puncturing to a portion of the total band of the PPDU (e.g., a 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.

[0118] For example, the pattern of preamble puncturing can be pre-set. For example, when a first puncturing pattern is applied, puncturing may be applied only to a secondary 20 MHz band within an 80 MHz band. For example, when a second puncturing pattern is applied, puncturing may be applied only to one of two secondary 20 MHz bands included in a secondary 40 MHz band within an 80 MHz band. For example, when a third puncturing pattern is applied, puncturing may be applied only to a secondary 20 MHz band included in a primary 80 MHz band within a 160 MHz band (or 80+80 MHz band). For example, when the fourth puncturing pattern is applied, within the 160 MHz band (or 80+80 MHz band), the primary 40 MHz band included in the primary 80 MHz band is present, and puncturing may be applied to at least one 20 MHz channel that does not belong to the primary 40 MHz band.

[0119] 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.

[0120] 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 configured individually in 80 MHz units. 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 regarding a 160 MHz bandwidth, and the second field of the second U-SIG may include information regarding preamble puncturing applied to the second 80 MHz band (i.e., information regarding a preamble puncturing pattern). Meanwhile, the UHR-SIG following the first U-SIG may include information regarding preamble puncturing applied to the second 80 MHz band (i.e., information regarding a preamble puncturing pattern), and the UHR-SIG following the second U-SIG may include information regarding preamble puncturing applied to the first 80 MHz band (i.e., information regarding a preamble puncturing pattern).

[0121] Additionally or generally, U-SIG and UHR-SIG may include information regarding preamble puncturing based on the following method. 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).

[0122] 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 may contain different U-SIGs.

[0123] The UHR-SIG of FIG. 5 may include control information for a receiving STA. The UHR-SIG may be transmitted through at least one symbol, and one 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.

[0124] UHR-SIG provides additional signals to the U-SIG field, enabling the STA to interpret / decode the UHR PPDU. The UHR-SIG field may include U-SIG overflow bits that apply commonly to all users. Additionally, the UHR-SIG field contains resource allocation information, making it possible for the STA to look up resources used in fields containing data fields / UHR-STF / UHR-LTF (i.e., UHR modulated fields of an UHR PPDU).

[0125] The frequency resources of the UHR-LTF, UHR-STF, and data fields illustrated in FIG. 5 can be determined based on a RU (resource unit) defined by a plurality of subcarriers / tones. That is, the UHR-LTF, UHR-STF, and data fields of this specification can be transmitted / received through a RU (resource unit) defined by a plurality of subcarriers / tones.

[0126] FIG. 6 is a diagram showing the arrangement of resource units (RUs) used for a 20 MHz PPDU. That is, 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.

[0127] As shown at the top of Fig. 6, 26 units (i.e., units corresponding to 26 tones) may be arranged. Six tones may be used as a guard band in the leftmost band of the 20 MHz band, and five tones may be used as a guard band in the rightmost band of the 20 MHz band. Additionally, seven DC tones are inserted into the center band, i.e., the DC band, and 26 units corresponding to 13 tones may exist on the left and right sides of the DC band. Furthermore, 26 units, 52 units, and 106 units may be allocated to other bands. Each unit may be allocated for a receiving station, i.e., a user.

[0128] Meanwhile, the RU arrangement of Fig. 6 is utilized not only for situations involving multiple users (MU) but also for situations involving a single user (SU), in which case it is possible to use one 242-unit as shown at the bottom of Fig. 4, and in this case, three DC tones can be inserted.

[0129] In the example of FIG. 6, various sizes of RUs, namely 26-RU, 52-RU, 106-RU, 242-RU, etc., are proposed. Since the specific size 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 indicated as N-tone RU, etc. For example, 26-RU may be indicated as 26-tone RU.

[0130] Figure 7 is a diagram showing the arrangement of resource units (RU) used for a 40 MHz PPDU.

[0131] Just as various sizes of RUs were used in the example of FIG. 6, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc., may also be used in the example of FIG. 7. Additionally, 5 DC tones may be inserted at the center frequency, 12 tones may be used as guard bands in the leftmost band of the 40 MHz band, and 11 tones may be used as guard bands in the rightmost band of the 40 MHz band.

[0132] In addition, as described, 484-RU 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.

[0133] FIG. 8 is a diagram showing the arrangement of resource units (RUs) used for an 80 MHz PPDU. The arrangement of resource units (RUs) used in this specification may be varied. For example, the arrangement of resource units (RUs) used in the 80 MHz band may be varied.

[0134] FIG. 9 illustrates the operation according to UL-MU. As illustrated, a transmitting STA (e.g., AP) can establish a channel connection through contending (i.e., Backoff operation) and transmit a Trigger frame (930). That is, the transmitting STA (e.g., AP) can transmit a PPDU containing the Trigger frame (930). When the PPDU containing the Trigger frame is received, a TB (trigger-based) PPDU is transmitted after a delay of SIFS.

[0135] TB PPDUs (941, 942) may be transmitted at the same time and may be transmitted from multiple STAs (e.g., User STAs) with AIDs indicated within the Trigger frame (930). The ACK frame (950) for the TB PPDU may be implemented in various forms.

[0136] Figure 10 shows an example of a channel used / supported / defined within the 2.4 GHz band.

[0137] The 2.4 GHz band may be referred to by other names, such as the first band (band). Additionally, 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 located between 2.4 and 2.5 GHz) are used / supported / defined.

[0138] The 2.4 GHz band may include multiple 20 MHz channels. The 20 MHz channels 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 to channel index 1 may be 2.412 GHz, the center frequency of a 20 MHz channel assigned to channel index 2 may be 2.417 GHz, and the center frequency of a 20 MHz channel assigned to channel index N may be (2.407 + 0.005*N) GHz. Channel indices may be referred to by various names, such as channel numbers. The specific numerical values ​​of channel indices and center frequencies may change.

[0139] FIG. 10 illustrates four channels within a 2.4 GHz band as an example. The illustrated first frequency range (1010) to fourth frequency range (1040) may each include one channel. For example, the first frequency range (1010) may include channel 1 (a 20 MHz channel having index 1). In this case, the center frequency of channel 1 may be set to 2412 MHz. The second frequency range (1020) may include channel 6. In this case, the center frequency of channel 6 may be set to 2437 MHz. The third frequency range (1030) may include channel 11. In this case, the center frequency of channel 11 may be set to 2462 MHz. The fourth frequency range (1040) may include channel 14. In this case, the center frequency of channel 14 may be set to 2484 MHz.

[0140] FIG. 11 illustrates an example of a channel used / supported / defined within the 5 GHz band.

[0141] The 5 GHz band may be referred to by other names such as the second band / band. The 5 GHz band may refer to a frequency range in which channels with a center frequency of 5 GHz or higher 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 may be changed.

[0142] Multiple channels within the 5 GHz band include UNII (Unlicensed National Information Infrastructure)-1, UNII-2, UNII-3, and ISM. UNII-1 may be referred to as UNII Low. UNII-2 may include frequency regions referred to as UNII Mid and UNII-2 Extended. UNII-3 may be referred to as UNII-Upper.

[0143] Multiple channels may be configured within the 5 GHz band, and the bandwidth of each channel may be varied, such as 20 MHz, 40 MHz, 80 MHz, or 160 MHz. For example, the 5170 MHz to 5330 MHz frequency range within UNII-1 and UNII-2 may be divided into eight 20 MHz channels. The 5170 MHz to 5330 MHz frequency range may be divided into four channels through a 40 MHz frequency range. The 5170 MHz to 5330 MHz frequency range may be divided into two channels through an 80 MHz frequency range. Alternatively, the 5170 MHz to 5330 MHz frequency range may be divided into one channel through a 160 MHz frequency range.

[0144] FIG. 12 illustrates an example of a channel used / supported / defined within the 6 GHz band.

[0145] The 6 GHz band may be referred to by other names such as the third band / band. The 6 GHz band may refer to a frequency range in which channels with a center frequency of 5.9 GHz or higher are used / supported / defined. The specific figures shown in FIG. 12 are subject to change.

[0146] For example, the 20 MHz channel of FIG. 12 can be defined starting from 5.940 GHz. Specifically, the leftmost channel among the 20 MHz channels of FIG. 12 may have index 1 (or channel index, channel number, etc.), and the center frequency may be assigned as 5.945 GHz. That is, the center frequency of the index N channel may be determined as (5.940 + 0.005*N) GHz.

[0147] Accordingly, the indices (or channel numbers) of the 20 MHz channel in 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, 197, It may be 201, 205, 209, 213, 217, 221, 225, 229, 233. Also, according to the (5.940 + 0.005*N) GHz rule described above, the index of the 40 MHz channel of FIG. 12 may 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.

[0148] The structure and types / subtypes of MAC frames are described below.

[0149] FIG. 13 shows an example of a MAC frame header. As illustrated, the MAC frame may include a frame control field / information of 2 octets, a duration field / information of 2 octets, a Receiver Address (RA) field / information of 6 octets, and a Transmitter Address (TA) field / information of 6 octets. As illustrated in FIG. 13, the four fields may be consecutive. 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.

[0150] The MAC header shown in FIG. 13 may be located at the very beginning of the MAC frame. That is, the MAC frame may include a MAC header such as that in FIG. 13 and a MAC body field / information following the MAC header. The MAC frame containing the MAC header of FIG. 13 is inserted / included in the data field of the PPDU (e.g., UHR PPDU) shown in FIG. 5.

[0151] MAC frames included in the data fields of the PPDU of this specification may be classified into various types. For example, MAC frames of this specification may be classified into control frames, management frames, and data frames.

[0152] For example, a 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 WLANs. For the management frame, the values ​​of the type fields (B3 and B2) in FIG. 13 are set to 00. Additionally, 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).

[0153] For example, the control frame includes the 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 WLANs. For the control frame, the values ​​of the type fields (B3 and B2) in FIG. 13 are 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).

[0154] For example, the data frame includes (QoS) Data, (QoS) Null, etc., defined in conventional WLANs. For the management frame, the value of the type field (B3 and B2) in FIG. 13 is set to 10.

[0155] MAC frames / signals used in this specification can be identified through the type field / information and subtype field / information described above. For example, the “frame” in this specification may refer to a MAC frame in which the type bits B3 and B2 within the frame control field of the MAC header are set to 01, and the subtype bits B7, B6, B5, and B4 within the frame control field are set to 0010. Various MAC frames described in this specification are inserted into / included in the data fields of various PPDUs (e.g., HE / VHT / HE / EHT / UHR PPDU).

[0156] FIG. 14 shows a modified example of a transmitting device and / or receiving device of the present specification.

[0157] The device illustrated in FIGS. 1 to 4 (e.g., AP STA, non-AP STA) can be modified as in FIG. 14. The transceiver (630) in FIG. 14 may be identical to the transceiver (113, 123) in FIG. 1. The transceiver (630) in FIG. 14 may include a receiver and a transmitter.

[0158] The processor (610) of FIG. 14 may be the same as the processor (111, 121) of FIG. 1. Or, the processor (610) of FIG. 14 may be the same as the processing chip (114, 124) of FIG. 1.

[0159] 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.

[0160] Referring to FIG. 14, a power management module (611) manages power for 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 associated keys used to identify and authenticate a subscriber in a mobile device such as a mobile phone and a computer.

[0161] Referring to FIG. 14, the speaker (640) can output sound-related results processed by the processor (610). The microphone (641) can receive sound-related inputs to be used by the processor (610).

[0162] 1. How to perform Non-Primary Channel Access (NPCA) or Secondary Channel Access (SCA)

[0163] This specification proposes a secondary channel access process, and first defines the primary channel and the secondary channel as follows.

[0164] The primary channel is a common operating channel for all STAs that are members of the BSS, and in a 20MHz, 40MHz, 80MHz, 160MHz, 80+80MHz, or 320MHz BSS, the primary channel is the primary 20MHz channel.

[0165] A secondary channel is a channel associated with a primary channel used to create a channel wider than the primary channel, and in 40 MHz, 80 MHz, 160 MHz, 80+80 MHz, or 320 MHz BSS, the secondary channel is a secondary 20 MHz channel. The above secondary channel may also be referred to as a non-primary channel or a Non-Primary Channel Access (NPCA) primary channel. Furthermore, SCA (Secondary Channel Access) may also be referred to as NPCA (Non-Primary Channel Access). In the specification described below, these terms will be used interchangeably.

[0166] Currently, 802.11 performs channel access based on the primary channel. That is, an STA can transmit frames, including secondary channels that are IDLE, only when the primary channel is IDLE and the back-off counter (BC) becomes zero; to achieve this, all STAs perform Clear Channel Assessment (CCA) with priority given to the primary channel. Therefore, APs announce the primary channel of the BSS and always include the primary channel to transmit management frames, such as Beacon and Probe Response frames. While this mechanism is effective for protection as it allows frame exchange between all STAs and APs to be performed without interference, it is inefficient from the perspective of medium usage because access to secondary channels that are IDLE is not possible when only the primary channel is BUSY.

[0167] FIG. 15 illustrates an example of channel access in an 802.11 wireless LAN system.

[0168] FIG. 15 shows channel access based on the primary channel at an 80 MHz bandwidth. As shown in FIG. 15, the primary channel and secondary channel are referred to as follows in this specification.

[0169] P20: Primary 20MHz Channel

[0170] S20: Secondary 20MHz Channel (If Bandwidth is 40MHz, it refers to the remaining 20MHz secondary channel excluding P20)

[0171] S40: Secondary 40MHz Channel (If Bandwidth is 80MHz, it refers to the remaining 40MHz secondary channel excluding P20 / S20)

[0172] S80: Secondary 80MHz Channel (If Bandwidth is 160MHz, it refers to the remaining 80MHz secondary channels excluding P20 / S20 / S40)

[0173] S160: Secondary 160MHz Channel (When Bandwidth is 320MHz, it refers to the remaining 160MHz secondary channels excluding P20 / S20 / S40 / S80)

[0174] S320: Secondary 320MHz Channel (When Bandwidth is 640MHz, it refers to the remaining 320MHz secondary channels excluding P20 / S20 / S40 / S80 / S160)

[0175] If P20 is in a BUSY state, such as CCA or NAV (Network Allocation Vector), it does not reduce BC and waits until it becomes IDLE. Through this back-off process, when BC becomes 0, it checks the channel status of S20 and S40 (i.e., CCA) and transmits the frame. In this example, since S40 is BUSY, the STA transmits a frame corresponding to a 40MHz PPDU through P20 and S20.

[0176] As mentioned above, as shown in FIG. 15, when P20 is BUSY and S20 and S40 are IDLE, the efficiency of medium usage is reduced because bandwidth corresponding to 60 MHz is wasted. Therefore, this specification proposes a method for accessing a secondary channel when P20 is BUSY. Specifically, this specification proposes information necessary for efficient secondary channel access and a secondary channel access method using this information.

[0177] Designations (names) in this specification may be changed, and STA may include AP STA or non-AP STA.

[0178] 1.1. STA Capabilities for Secondary Channel Access

[0179] Basically, capabilities for Secondary Channel Access (SCA) can be defined. For example, the STA and AP can inform each other whether SCA capabilities are supported or enabled. SCA capabilities can be determined by the first type of CCA (referred to as preamble detection (PD)), which is capable of identifying Wi-Fi frames performed on the Primary Channel (PCH), that is, whether frames can be decoded on the Secondary Channel (SCH). Through this, NAV can be configured on the SCH as well.

[0180] - Level 0: No Back-off on SCH: SCH performs Type 2 CCA as before. That is, it performs CCA that detects Wi-Fi signals (referred to as guard interval detection (GID)), CCA that detects signals of a certain strength or higher (referred to as energy detection (ED)), etc.

[0181] - Level 1: Back-off on a SCH at a time: PD, which is 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: Perform PD, which is a Type 1 CCA, on one or more secondary channels simultaneously. (i.e., CCA performed on multiple SCHs simultaneously is possible.)

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

[0184] 1.2. 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 may 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 may be updated based on a PPDU identified as intra-BSS.

[0186] Basically, if Intra-BSS NAV is configured in the STA PCH, the following situations may occur.

[0187] - When an AP exchanges frames with a STA within a TXOP it has acquired, the other STA is configured with an intra-BSS NAV based on the primary channel as a result. In this case, if the STA with the intra-BSS NAV configured accesses the SCH and transmits a frame to the AP, the AP cannot receive it (i.e., the frame on the SCH transmitted from the STA to the AP) when the AP transmits it (e.g., DL Data, Ack, etc.).

[0188] Therefore, STA can perform SCA if a Basic NAV from a BSS other than its own (i.e., OBSS (Overlapping Basic Service Set)) is set in PCH.

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

[0190] Figure 16 illustrates an example of the basic procedure of SCA.

[0191] Figure 16 illustrates the basic SCA process. If Basic NAV is set while the STA is performing back-off at P20, back-off is performed at S20 at the time the NAV is set. (Switching delay may occur for PD from P20 to S20.) This differs from the CCA method in that CCA can be performed at S20, and it can be performed at all levels. The reason for performing back-off at S20 is that if neighboring STAs with the same or similar Operation channel as this STA do not perform back-off and simultaneously transmit frames while in IDLE, collisions may occur, which could result in channel waste.

[0192] The considerations when performing SCA are as follows.

[0193] i) Frame transmission method

[0194] Previously, when the Back-off counter became 0 through Back-off in P20, a Frame could be transmitted through P20 and one or more SCHs that were IDLE / BUSY based on the IDLE / BUSY status of one or more SCHs. Therefore, for SCA, a change is required because the situation where P20 is BUSY must be taken into account, and the Back-off operation for this is as follows.

[0195] - STA can perform back-off in one or more SCHs when P20 is BUSY.

[0196] The reason for performing back-off in SCH is that if a neighboring STA with the same or similar Operation channel as a specific STA does not perform back-off on a channel that includes or overlaps with the specific STA's SCH, and is determined to be IDLE as a result of CCA for a channel for a certain short period of time (e.g., 1 slot), and the specific STA and the neighboring STA transmit frames simultaneously, a collision may occur, which could result in channel waste.

[0197] => If the remaining NAV timer in the current PCH (P20) is not enough time to catch the TXOP in SCH, the SCH may not perform Back-off.

[0198] - When the Back-off counter becomes 0, the STA can perform a second type of CCA on SCH(s) other than the one or more SCHs that performed the Back-off. For example, it can determine whether the channel is IDLE or BUSY by performing a CCA on SCH(s) other than the SCH that performed the Back-off during a certain period of time (e.g., PIFS) prior to the point when the Back-off counter in the SCH that performed the Back-off became 0.

[0199] - 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.

[0200] For example, in the example of FIG. 16, back-off is performed at S20, and when the back-off counter becomes 0, both 20MHz channels of S40 are in an IDLE state. Therefore, in this case, an 80MHz PPDU (including a MAC Frame) containing a signaling that P20 has been punctured can be transmitted.

[0201] ii) TXOP configuration method

[0202] Since CCA must be performed on P20 by default when the Basic NAV in P20 expires, the TXOP in SCH is set so that the end time of the TXOP ends before the time when the Basic NAV expires.

[0203] If the TXOP is set to terminate after the Basic NAV expires, a problem arises where the Legacy STA, etc., cannot receive the frame because it can transmit it via P20 after the Basic NAV set for the STA. Additionally, if the target beacon transmission time (TBTT) is set in the middle of the Basic NAV, an issue may occur because the AP must prepare to transmit the beacon immediately after the Basic NAV. Furthermore, non-AP STAs also face the problem of waiting longer than scheduled because they cannot receive the beacon that the AP needs to transmit on time. Therefore, normal frame exchange can be performed at P20 by applying the condition that 'the TXOP's end time is set to terminate before the Basic NAV expires.'

[0204] => If there is not enough time to catch a TXOP, the frame is not transmitted. That is, if it is difficult to catch a TXOP for the interval between when the Back-off counter (BC) in the SCH is 0 and when the Basic NAV in the PCH ends, the frame is not transmitted.

[0205] For example, as shown in the example of Fig. 16, back-off is performed at S20 so that the back-off counter becomes 0 and the TXOP is captured, so that it terminates earlier than the time when the Basic NAV terminates.

[0206] 2. How to check if the receiving side performs NPCA

[0207] Furthermore, after switching to NPCH, the peer STA may not switch to NPCH for various reasons, just like the STA. For example, due to a hidden node issue, the peer STA's PCH may not be in a busy state and thus may not switch to NPCH. To address this, instead of the STAs switching to NPCH immediately transmitting long frames, a method is required to verify more quickly whether the receiving side is performing NPCA.

[0208] When performing frame exchange in NPCA, AP may announce the maximum length of a frame that can be used as the first frame (referred to herein as Length Threshold for NPCA).

[0209] By announcing the Length Threshold for NPCA field, the length of the first frame that can be used can be limited when STAs performing NPCA switch to NPCH. This has the advantage of preventing unnecessary waste of the medium, as it allows for faster verification than the method of attempting to transmit a long frame to check if peer STAs are also performing NPCA.

[0210] For example, the unit of the above length can be expressed in us, and assuming the Length Threshold for NPCA field has an 8-bit value, in the case of 0000 1111, the Length Threshold for NPCA can be 15 us. Accordingly, STAs that have switched to NPCH can transmit a frame having a length of 15 us or less as the first frame to transmit.

[0211] Additionally or alternatively, the first frame can be a data frame or a control frame.

[0212] Additionally or alternatively, the Length Threshold for NPCA may be the PPDU length indicated in the LENGTH field of L-SIG, and may be the frame length excluding the PHY header.

[0213] Additionally or alternatively, the Length Threshold for NPCA field may be set based on the size (PPDU length or frame length) of the RTS / MU-RTS / BSRP.

[0214] 3. The problem that successful frame exchange does not occur in NPCA because the AP and STA have different views on the PCH.

[0215] Figure 17 illustrates a network topology example and an example in which Basic NAV is configured in the PCH of NPCA STAs.

[0216] In addition, as shown in Fig. 17, when NPCA STA1 receives OBSS1 traffic, NPCA AP switches to NPCH only for NPCA STA1 because the OBSS1 traffic is not hearable. If NPCA AP continues to attempt frame exchange with NPCA AP without knowing that NPCA AP has not switched, the unnecessary contention window increases, and continuous waste of medium occurs (Case 2 described below). In other words, a problem arises where successful frame exchange does not occur in NPCA because the AP and STA have different views of the PCH.

[0217] Case 1) refers to the case where AP's PCH is BUSY and STA's PCH is IDLE, and Case 2) refers to the case where AP's PCH is IDLE and STA's PCH is BUSY.

[0218] Case 1) is a problem that can occur even in existing Wi-Fi systems. For example, if an AP is busy at its PCH, that AP cannot respond to a STA even if there is a STA performing frame exchange at its PCH. Additionally, since the AP may have STAs that have switched to the NPCH due to their PCH being busy, in addition to STAs with idle PCHs, it can perform NPCA with those STAs. On the other hand, as in Case 2), if the AP's PCH is idle but the STA's PCH is busy, and the STA alone switches to the NPCH to perform NPCA, it results in channel waste, making Case 2) a more significant problem. In addition, NPCA AP and NPCA STA2 receive OBSS2 traffic and switch to NPCH to perform NPCA, and NPCA STA1 subsequently receives OBSS1 traffic. Since NPCA STA1 has a longer Basic NAV than NPCA AP, it may unnecessarily waste medium by continuing to attempt frame exchange at NPCH even after NPCA AP has switched back to PCH.

[0219] 4. Method to solve the above problem

[0220] 1) NPCA APs announce the hearable OBSS AP list to the BSS.

[0221] The OBSS AP list announced by NPCA AP may include at least the following information.

[0222] - BSS Color (6 bits): Represents BSS Color information for the received OBSS traffic.

[0223] - BSSID (48 bits): Refers to the BSSID (Basic Service Set Identifier) ​​information for the incoming OBSS traffic.

[0224] Additionally or alternatively, the MAC address of a non-AP STA may also be included in the OBSS AP list information.

[0225] - UL / DL (2 bits): Indicates whether the received OBSS traffic is UL (uplink) traffic or DL ​​(downlink) traffic.

[0226] e.g., when the above UL / DL field has a value of 2 bits, 0 indicates DL traffic, 1 indicates UL traffic, and 2 indicates both DL / UL traffic.

[0227] Additionally, or alternatively, a non-AP STA can also provide a hearable OBSS AP list to the AP.

[0228] Figure 18 illustrates an example of an NPCA AP informing the OBSS AP list.

[0229] As shown in Fig. 18, when an NPCA AP announces a list of hearable APs to STAs within a BSS based on BSS color and UL / DL fields, the NPCA AP can announce that the BSS color is 11 and that DL traffic is hearable. Subsequently, when OBSS AP2 transmits data to OBSS STA2, STAs performing NPCA can check the BSS color information and DL / UL information of the traffic when OBSS traffic is received. If the traffic is included in the list of OBSS APs announced by the AP, they can switch to NPCH to perform NPCA. Otherwise, the STAs may not switch.

[0230] Additionally or alternatively, if UL / DL information is not included in the OBSS AP list, but hearable BSS Color is limited to OBSS Traffic (DL) transmitted by the AP and announced in the OBSS AP list, then when OBSS traffic is received, the BSS color is checked through PHY header decoding, and the UL / DL field of the PHY header is checked; if it is DL, a switch is performed. When using such information, it may be suitable for subsequent PPDU formats that include a HE PPDU from which information necessary for NPCA can be obtained through PHY header decoding.

[0231] In addition, as another example, when an NPCA AP announces OBSS AP list information based on a BSSID, when OBSS traffic is received, the address in the TA (Transmitter Address) field of the OBSS traffic is compared with the BSSID included in the OBSS AP list. If they match, the NPCA STA2 can determine that the NPCA AP has also received the same OBSS traffic, switch to the NPCH, and perform NPCA with the same Basic NAV. This method, in which NPCA STAs can decide whether to switch by comparing the BSSID included in the OBSS AP list with the address in the TA field of the received OBSS traffic, may be suitable for OBSS Control frame exchange ((MU-)RTS / CTS) or pre-802.11ax PPDU that require MAC header decoding.

[0232] 2) Triggered-based NPCA operation

[0233] When an AP switches to an NPCH, it transmits an Initial Control Frame (ICF) to identify which STA has switched. At this time, for STAs that transmit an Initial Response Frame (ICR), the AP can identify that the STA has switched and perform NPCA with those STAs. Furthermore, when operating Triggered-based NPCA, there is an advantage in that channel wastage does not occur because non-AP STAs cannot transmit UL data first without AP scheduling. In other words, non-AP STAs may not perform Enhanced Distributed Channel Access (EDCA) for the NPCH until there is a direct trigger from the AP.

[0234] Method 1) Explicit signaling of TB based NPCA

[0235] When performing NPCA within BSS, AP can announce an indicator (i.e., TB based NPCA mode) on whether to operate Triggered-based NPCA.

[0236] When the above TB based NPCA mode field has a value of 2 bits, if it is 0, it means that Triggered-based NPCA is performed (the TXOP holder is restricted to the AP), and if it is 1, it means that Triggered-based NPCA is not performed (the TXOP holder can be an AP or a non-AP STA). If the above TB based NPCA mode field is 2, it means that Triggered-based operation is performed only for the first TXOP obtained after the AP switches to the NPCH, and Triggered-based operation may not be performed for subsequent TXOPs while NPCA is performed on the NPCH.

[0237] Additionally or alternatively, the information can be defined for each STA. That is, for a specific STA associated within the BSS, the TB-based NPCA mode can be set to 0 and for another specific STA, the TB-based NPCA mode can be set to 1 for transmission.

[0238] For example, STAs with the TB-based NPCA mode set to 0 cannot become TXOP holders, while STAs with the mode set to 1 can become TXOP holders.

[0239] Additionally or alternatively, if the AP announces or enables the TB-based NPCA mode at the BSS level, non-AP STAs may indicate whether to accept or reject it based on the value of the TB-based NPCA mode field.

[0240] For example, if the AP sets the TB-based NPCA mode to 0, STAs that want TB-based NPCA may respond with an accept indicator, and STAs that want to become TXOP holders may respond with a reject indicator. Based on this, the AP can perform TB-based NPCA only for the accepted STAs, and the rejected STAs can become TXOP holders.

[0241] As another example, when the AP announces by setting the TB-based NPCA mode to 1, the AP and STA engage in contention according to the existing EDCA channel access rule to obtain the TXOP.

[0242] Additionally or alternatively, if all non-AP STAs accept, the TXOP holder can be restricted to APs only and perform TB-based NPCA within the BSS.

[0243] Additionally or alternatively, if at least one non-AP STA rejects and responds, the AP and STA will perform contention according to the existing EDCA channel access rule to obtain the TXOP.

[0244] Additionally or alternatively, a non-AP STA can make a request to the AP that reflects its intention to become a TXOP holder by sending a frame that sets its TB-based NPCA mode to 1.

[0245] Additionally or alternatively, when an AP receives a request from a non-AP STA, it may respond by considering channel conditions or congestion within the BSS. When responding, it may include a status code indicating whether to accept or reject the non-AP STA's request.

[0246] Additionally or alternatively, the above TB-based NPCA mode field may be transmitted by being included in the AP's Beacon, Probe response frame, association response frame, or Action frame newly defined in 802.11bn (which may be referred to as the NPCA Parameter Update frame in this specification).

[0247] Additionally or alternatively, the above TB-based NPCA mode field may be transmitted by being included in a Probe request frame, an association request frame, or an Action frame newly defined in 802.11bn (which may be referred to as an NPCA Parameter Update frame in this specification).

[0248] Method 2) Utilization of MU EDCA Parameters

[0249] FIG. 19 illustrates an example of the MU EDCA Parameter Set element format and the MU AC Parameter Record field format.

[0250] The HE (802.11ax) AP can announce MU EDCA Parameters in addition to EDCA parameters. The MU EDCA Parameters Set element is configured in a format as shown at the top of FIG. 19, and each MU AC_XX (e.g., BE (Best Effort), BK (Background), VI (Video), VO (Voice)) Parameter Record field format within the element can be configured as shown at the bottom of FIG. 19.

[0251] The way the MU EDCA Protocol operates is as follows.

[0252] When a Non-AP HE STA receives a Basic Trigger frame containing a User Info field addressed to it and at least one Quality of Service (QoS) frame for the Trigger frame is successfully transmitted as an HE TB PPDU, the parameters announced in the existing EDCA Parameter Set are not used, and the MU EDCA parameters are used.

[0253] That is, the STA sets its CWmin[AC], CWmax[AC], AIFSN[AC], and MUEDCATimer[AC] values ​​based on the dot11MUEDCATable value, and MUEDCATimer[AC] is initialized by the MU EDCA Timer subfield value, and until the timer (MUEDCATimer[AC]) expires, it uses the MU EDCA Parameter set by the dot11MUEDCATable value. Additionally, if the AIFSN (Arbitration Inter-Frame Space Number) value is 0, it means that the EDCAF (EDCA Function) corresponding to the AC (Access Category) is suspended until the timer (MUEDCATimer[AC]) expires. When the timer (MUEDCATimer[AC]) expires, the parameter is restored to the value defined in the existing EDCA Parameter Set.

[0254] Based on this method, the following rule can be defined without the explicit TB-based NPCA mode of method 1).

[0255] i) When switching to the NPCA primary channel, MUEDCATimer[AC] can be initialized by the MU EDCA Timer subfield value, and countdown occurs until MUEDCATimer[AC] becomes 0 or is reset by a specific condition.

[0256] -> If MUEDCATimer[AC] is set to zero and / or non-zero value in the BSS primary channel, it can be initialized to the MU EDCA Timer subfield.

[0257] Additionally or alternatively, MUEDCATimer[AC] can be initialized based on the MU EDCA Timer[AC] value upon receiving a Trigger frame addressed to it on the NPCA primary channel.

[0258] Additionally or alternatively, the Trigger frame may include a Basic Trigger frame, a BSRP (Buffer Status Report Poll) Trigger frame, a BSRP NTB (Non-Trigger-Based) Trigger frame, etc.

[0259] ii) For all ACs, the AIFSN[AC] value is always set to 0 regardless of the dot11MUEDCATable value.

[0260] Alternatively, the dot11MUEDCATable values ​​can be reused excluding the AIFSN[AC] value, and the CWmin[AC], CWmax[AC], and MUEDCATimer[AC] values ​​can be updated based on this.

[0261] That is, even if the triggering condition for the existing baseline MU EDCA Protocol is not satisfied in the NPCA primary channel, the STAs that have switched to the NPCA primary channel initialize the MU EDCA Timer with the MU EDCA Timer subfield value and perform EDCAF with the AIFSN[AC] value set to 0 until the timer expires.

[0262] Until the corresponding timer expires, the value of AIFSN[AC] is set to 0 for all ACs, so untriggered UL is not allowed.

[0263] -> Additionally or alternatively, when the timer expires, STA can perform EDCA using the existing EDCA parameter.

[0264] iii) From the time STA starts switching to the NPCA primary channel, MUEDCATimer[AC] can be counted down until it is initialized by the MU EDCA Timer subfield value and becomes 0.

[0265] For example, if the OBSS traffic is HE / EHT / UHR PPDU, the MUEDCATimer[AC] value is initialized and the countdown starts from the HE switch time, which is the earliest point in time when all information necessary for the NPCA operation can be obtained.

[0266] The HE switch time can be defined as immediately after HE-SIG-A field decoding for HE PPDUs, and immediately after U-SIG field decoding for EHT / UHR PPDUs.

[0267] FIG. 20 illustrates an example of EDCA operation using MU EDCA parameters when NPCA operation starts.

[0268] Figure 20 shows an example of the MU EDCA protocol being enabled when the NPCA operation starts. In the existing BSS primary channel, the MU EDCA protocol is not enabled, so non-AP STAs operating in the BSS primary channel perform EDCA based on the EDCA Parameter Set element. On the other hand, from the moment of switching to the NPCA primary channel, the MU EDCA protocol is triggered and EDCA is performed based on the MU EDCA Parameter Set. However, the MU EDCA Timer value is set to 10, and the CWmax and CWmin values ​​use the values ​​announced in the MU EDCA Parameter Set element, but the AISFN value is always set to 0 regardless of the value announced in the MU EDCA Parameter Set, so that when the MU EDCA protocol is operating, the non-AP STA can stop or suspend EDCAF until the corresponding MU EDCA Timer expires. This has the advantage that non-AP STAs can perform NPCA operations under the control of the AP by preventing untriggered UL transmission, as the AP must transmit the ICF for non-AP STAs to respond to the ICF.

[0269] - Additionally or alternatively, the MU EDCA Protocol can be enabled and the MU EDCA Timer can be set based on the MU EDCA Timer subfield value of the MU EDCA Parameter Set after the MU EDCA Protocol switches to the NPCA primary channel, the AP captures the TXOP on the NPCA primary channel and transmits a trigger frame, and the non-AP STA successfully transmits a UL TB PPDU in response to this.

[0270] <SCA에 대한 STA의 동작과정 #1>

[0271] - STA can be a non-AP STA or AP

[0272] In the present disclosure, an STA performing SCA may transmit frames / PPDUs on a SCH even during the time when NAV is set in the PCH. For example, an STA may transmit frames / PPDUs excluding / puncturing the PCH on one or more SCHs in an IDLE state determined by backoff performed on one or more SCHs and CCA results of one or more SCHs where backoff is not performed.

[0273] Additionally or alternatively, a TXOP initiated by a frame / PPDU transmission on the SCH may be configured to terminate before the NAV on the PCH is terminated. The length of the TXOP may be configured or indicated through the duration / ID field of the corresponding frame. For example, the value of the duration / ID field may be configured to the time required for the frame / PPDU exchange following the corresponding frame / PPDU (including the inter-frame interval (IFS)).

[0274] Additionally or alternatively, the EDCA Parameter Set for each SCH where Back-off is performed can 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 can be applied identically or differently to all SCHs.

[0275] In the present disclosure, an STA receiving a frame transmitted via an SCA may perform frame detection on the SCH even during the time when a NAV is set in the PCH. For example, the STA may perform backoff on the SCH if there is a frame to transmit, or it may attempt to receive whether there is a frame addressed to itself on the SCA even if there is no frame to transmit. Additionally, the STA may perform NAV setting / resetting based on the value of the duration / ID field of the frame detected on the SCH.

[0276] Additionally or alternatively, the EDCA Parameter Set for each SCH where Back-off is performed can 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 can be applied identically or differently to all SCHs.

[0277] The PPDU to which the signal of the present specification is transmitted / received may include a data field.

[0278] The above data field includes user data and may include packets for the upper layer. That is, it may include MPDU (MAC Frame).

[0279] For example, the duration / ID field in the MAC header included in the MPDU may be set to a value containing the time length of a frame exchange following the frame or PPDU transmitted excluding (or puncturing) the PCH, if channel access operations on the secondary channel are supported. 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.

[0280] In addition, as shown in Figure 1 above, the transmitting device and the receiving device may each include a memory, a processor, and a transceiver.

[0281] The above memory can store information regarding a plurality of Secondary Channel Accesses as described in this specification.

[0282] The above processor can perform back-off in the Secondary Channel based on the information stored in the memory, generate various RUs, and configure PPDUs. The above processor is described in this specification<SCA에 대한 STA의 동작과정 #1> It can be configured to perform all or part of it.

[0283] 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).

[0284] Alternatively, the processor (111) may generate a transmission PPDU and store information regarding the transmission PPDU in memory (112).

[0285] For example, the processor (111) of the transmitting device may be configured to perform the operation of the transmitting STA according to the example of the present disclosure. For example, the processor (111) may be configured to transmit a frame on the SCH through the transceiver (113) during the time that NAV is set on the PCH. For example, the processor (111) may be configured to perform 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 that excludes / punctures the PCH on one or more SCHs through the transceiver (113). 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 initiating the transmission of a frame / PPDU on the SCH is terminated before the time when NAV on the PCH is terminated.

[0286] Additionally, the transceiver (123) of the receiving device can receive PPDU based on the control of the processor (121). For example, the transceiver (123) may include a plurality of sub-units (not shown). For example, the transceiver (123) may include at least one receiving antenna and a filter for said receiving antenna.

[0287] The PPDU received through the transceiver (123) can be stored in memory (122). The processor (121) can process decoding for the received PPDU through memory (122). The processor (121) can obtain control information (e.g., SIG) regarding the BW / Tone-Plan / RU included in the PPDU and store the obtained control information in memory (122).

[0288] The processor (121) can perform decoding on the received PPDU. Additionally, the processor (121) can process the decoded data. For example, the processor (121) can perform a processing operation to transmit information regarding the decoded data field to an upper layer (e.g., MAC layer). Additionally, if the generation of a signal is directed from the upper layer to the PHY layer in response to the data transmitted to the upper layer, a subsequent operation can be performed.

[0289] For example, the processor parses the MAC PDU obtained through PHY decoding of the DATA field of the PPDU received through the transceiver.

[0290] For example, the processor (121) of the receiving device may be configured to perform the operation of the receiving STA according to the example of the present disclosure. For example, the processor (121) may attempt to detect a frame on the SCH through the transceiver (123) for a time during which the NAV is set on the PCH. The processor (121) may be configured to decode / parse the frame addressed to it based on the frame received on the SCH. Additionally, the processor (121) may be configured to set / reset the NAV according to the value of the duration / ID field of the frame not addressed to it.

[0291] FIG. 21 is a flowchart illustrating the operation of a transmitting device according to the present embodiment.

[0292] An example of FIG. 21 can be performed on a transmitting STA or a transmitting device (AP and / or non-AP STA).

[0293] Some of the steps (or detailed sub-steps described later) of the example in Fig. 21 may be omitted or changed.

[0294] Through step S2110, the transmitting device (transmitting STA) can obtain information regarding the above-described 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.

[0295] Through step S2120, the transmitting device can construct / generate a PPDU based on acquired control information. The step of constructing / generating the PPDU may include the step of constructing / generating each field of the PPDU. That is, step S2120 includes the step of constructing a UHR-SIG field containing control information regarding a Tone Plan. That is, step S2120 may include the step of constructing a field containing control information (e.g., N bitmap) indicating the size / location of the RU and / or the step of constructing a field containing an identifier (e.g., AID) of the STA receiving the RU.

[0296] Additionally, step S2120 may include the step of generating an STF / LTF sequence transmitted through a specific RU. The STF / LTF sequence may be generated based on a pre-configured STF generation sequence / LTF generation sequence.

[0297] Additionally, step S2120 may include a step of generating a data field (i.e., MPDU) transmitted through a specific RU.

[0298] The transmitting device can transmit the PPDU configured through step S2120 to the receiving device based on step S2130.

[0299] While performing step S2130, the transmitting device may perform at least one of the following operations: CSD, Spatial Mapping, IDFT / IFFT operation, GI insertion, etc.

[0300] A signal / field / sequence configured according to the present specification can be transmitted in the form of FIG. 5.

[0301] FIG. 22 is a flowchart illustrating the operation of a receiving device according to the present embodiment.

[0302] The above-described PPDU can be received according to an example of FIG. 22.

[0303] An example of FIG. 22 can be performed on a receiving STA or a receiving device (AP and / or non-AP STA).

[0304] Some of the steps (or detailed sub-steps described later) of each example in Fig. 22 may be omitted.

[0305] A receiving device (receiving STA) can receive all or part of the PPDU through step S2210. The received signal may be in the form of FIG. 5.

[0306] 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 operation, and GI insert operation applied in step S2130.

[0307] In step S2220, the receiving device can perform decoding of 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.

[0308] More specifically, the receiving device can decode the L-SIG and UHR-SIG of the PPDU based on the Legacy STF / LTF and obtain information contained in the L-SIG and UHR-SIG fields. Information regarding various Tone Plans (i.e., RU) described in this specification may be included in the UHR-SIG, and the receiving STA can obtain information regarding the Tone Plan (i.e., RU) through the UHR-SIG.

[0309] In step S2230, the receiving device can decode the remainder of the PPDU based on information regarding the Tone Plan (i.e., RU) obtained through step S2220. For example, the receiving STA can decode the STF / LTF fields of the PPDU based on information regarding the one Plan (i.e., RU). Additionally, the receiving STA can decode the data fields of the PPDU based on information regarding the Tone Plan (i.e., RU) and obtain the MPDU contained in the data fields.

[0310] Additionally, the receiving device can perform a processing operation to transmit the decoded data through step S2230 to an upper layer (e.g., MAC layer). Furthermore, if the generation of a signal is instructed from the upper layer to the PHY layer in response to the data transmitted to the upper layer, a subsequent operation can be performed.

[0311] Hereinafter, the above-described embodiment will be explained with reference to FIGS. 1 to 22.

[0312] FIG. 23 is a flowchart illustrating a procedure for determining whether an AP according to the present embodiment will perform NPCA based on MU EDCA parameters.

[0313] 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, 802.11bn or next wi-fi). The next-generation wireless LAN system is a wireless LAN system that improves upon the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0314] This embodiment proposes a method for determining whether to perform channel access to a non-primary channel based on MU EDCA parameters to resolve the problem that the determination of whether the BSS primary channel is BUSY / IDLE between the AP and the non-AP STA may differ due to hidden node issues, etc. Additionally, this embodiment proposes a method for determining whether to perform channel access to the non-primary channel by having the AP directly transmit information regarding the OBSS AP list or trigger-based NPCA mode to the non-AP STA.

[0315] In step S2310, the first AP (access point) transmits a management frame to the first non-AP (non-access point) STA (station).

[0316] In step S2320, the first AP determines whether to perform channel access by switching from the primary 20 MHz channel to the non-primary channel based on the management frame.

[0317] The above management frame includes MU (Multi User) EDCA (Enhanced Distributed Channel Access) parameters.

[0318] The above MU EDCA parameters include information regarding the contention window, information regarding the Arbitration Inter-Frame Space Number (AIFSN), and information regarding the MU EDCA timer.

[0319] The AIFSN is set to 0 until the MU EDCA timer expires, so that channel access to the non-primary channel is not allowed.

[0320] Information regarding the above-mentioned contention window, information regarding the above-mentioned AIFSN, and information regarding the above-mentioned MU EDCA timer may be defined per AC (Access Category). The above-mentioned AIFSN is a value that determines the length of the waiting time for channel access, but if the above-mentioned AIFSN is 0, EDCA becomes disabled for the corresponding AC, and this disabled state may persist until the above-mentioned MU EDCA timer expires. Information regarding the above-mentioned contention window may include information regarding the minimum or maximum value of the contention window (for the corresponding AC).

[0321] The above MU EDCA timer may be defined as the time to use the above MU EDCA parameter for the corresponding AC. That is, the management frame may further include the EDCA parameter. After the above MU EDCA timer expires, channel access to the non-primary channel may be performed based on the above EDCA parameter (returning to the existing EDCA parameter).

[0322] After switching from the primary 20 MHz channel to the non-primary channel (when NPCA operation begins), the first AP may transmit a basic trigger frame to the first non-AP STA. The first AP may receive a Quality of Service (QoS) frame from the first non-AP STA based on the basic trigger frame. The MU EDCA parameters may be used after receiving the QoS frame. (The first non-AP STA may receive a basic trigger frame from the first AP. The first non-AP STA may transmit a Quality of Service (QoS) frame to the first AP based on the basic trigger frame. The MU EDCA parameters may be used after transmitting the QoS frame.)

[0323] Additionally, before switching from the primary 20 MHz channel to the non-primary channel, the first AP may transmit a basic trigger frame to the first non-AP STA. The first AP may receive a Quality of Service (QoS) frame from the first non-AP STA based on the basic trigger frame. The MU EDCA parameters may be used after receiving the QoS frame. Even after switching from the primary 20 MHz channel to the non-primary channel, the MU EDCA parameters may be used in the same way. (The first non-AP STA may receive a basic trigger frame from the first AP. The first non-AP STA may transmit a QoS frame to the first AP based on the basic trigger frame. The MU EDCA parameters may be used after transmitting the QoS frame. The MU EDCA parameters may be used in the same way even after switching from the primary 20 MHz channel to the non-primary channel.)

[0324] That is, the present embodiment proposes a method for determining whether to perform channel access (or EDCA) on a non-primary channel using MU EDCA parameters when a Non-Primary Channel Access (NPCA) operation begins. Specifically, the present embodiment proposes a method for suspending or suspending channel access (or EDCA) on the non-primary channel until the MU EDCA timer expires by setting the AIFSN value among the MU EDCA parameters to 0, regardless of the value transmitted from the MU EDCA parameters. This has the effect of preventing meaningless operations where the AP performs channel access on the BSS primary channel and the non-AP STA performs channel access on the non-primary channel, as the judgment regarding whether the BSS primary channel is BUSY / IDLE differs between the AP and the non-AP STA. Furthermore, it has the effect of preventing unnecessary media access and frame transmission attempts by non-AP STAs, thereby allowing for expected performance improvement in terms of power consumption.

[0325] After switching from the primary 20 MHz channel to the non-primary channel, the first AP can transmit an ICF (Initial Control Frame) to the first non-AP STA. The first AP can receive an ICR (Initial Control Response) from the first non-AP STA. (The first non-AP STA can receive an ICF (Initial Control Frame) from the first AP. The first non-AP STA can transmit an ICR (Initial Control Response) to the first AP.) Even if the AIFSN is set to 0 before the MU EDCA timer expires, channel access to the non-primary channel can be initiated based on the ICF. That is, when the first AP transmits the ICF, the first non-AP STA can perform channel access (or NPCA) to the non-primary channel under the control of the first AP.

[0326] The above non-primary channel may be a secondary channel capable of performing backoff while a Basic Network Allocation Vector (NAV) set by Overlapping Basic Service Set (OBSS) traffic is set on the above primary 20 MHz channel.

[0327] For example, the above OBSS traffic may be traffic transmitted and received between the second AP and the second non-AP STA. The second AP may be an OBSS AP with respect to the first AP. The second non-AP STA may be an OBSS non-AP STA within the Basic Service Set (BSS) of the second AP.

[0328] In addition, the present embodiment proposes a method for determining whether to perform channel access to the non-primary channel by having the AP directly transmit information regarding the OBSS AP list or trigger-based NPCA mode to the non-AP STA.

[0329] For example, the first AP may transmit information regarding an OBSS (Overlapping Basic Service Set) AP list to the first non-AP STA. Based on the fact that the information regarding the OBSS AP list includes information regarding OBSS traffic, the first AP may perform channel access by switching from the primary 20 MHz channel to the non-primary channel. (The first non-AP STA may receive information regarding the OBSS (Overlapping Basic Service Set) AP list from the first AP. Based on the fact that the information regarding the OBSS AP list includes information regarding OBSS traffic, the first non-AP STA may perform channel access by switching from the primary 20 MHz channel to the non-primary channel.)

[0330] The above OBSS AP list may include information regarding BSS color, information regarding BSSID (Basic Service Set Identifier), and information regarding UL (uplink) or DL ​​(downlink) traffic. The information regarding BSS color may include the BSS color for the OBSS traffic. The information regarding BSSID may include the BSSID for the OBSS traffic. The information regarding UL or DL ​​traffic may include information regarding whether the OBSS traffic is UL traffic or DL ​​traffic.

[0331] As another example, the first AP may transmit information regarding a trigger-based Non-Primary Channel Access (NPCA) mode to the first non-AP STA. The first AP may determine whether to perform trigger-based channel access on the non-primary channel based on the information regarding the trigger-based NPCA mode. (The first non-AP STA may receive information regarding the trigger-based Non-Primary Channel Access (NPCA) mode from the first AP. The first non-AP STA may determine whether to perform trigger-based channel access on the non-primary channel based on the information regarding the trigger-based NPCA mode.)

[0332] Based on the above trigger-based NPCA mode being set to a first value (e.g., 0), channel access based on the trigger is performed on the non-primary channel, and the first AP can become a TXOP (Transmission Opportunity) holder. That is, the NPCA can be performed based on the trigger of the first AP.

[0333] Based on the fact that the trigger-based NPCA mode is set to a second value (e.g., 1), channel access based on the trigger is not performed in the non-primary channel, and the first AP or the first non-AP STA can become the TXOP holder. That is, the first AP or the first non-AP STA can perform the NPCA by acquiring the TXOP based on competition according to the existing EDCA rule.

[0334] The above management frame may be a Beacon, a Probe response frame, or a (Re)Association response frame. Information regarding the OBSS AP list or the trigger-based NPCA mode may be included in the above management frame.

[0335] The first non-AP STA can perform backoff for the first non-primary channel. If the value of the backoff for the first non-primary channel is 0, the first non-AP STA can perform channel access for the second non-primary channel. The first non-AP STA can transmit or receive a PPDU (Physical Protocol Data Unit) through the IDLE channel among the first and second non-primary channels.

[0336] The first and second non-primary channels may be included in the non-primary channels. The first non-primary channel may be a secondary 20 MHz channel where the backoff is performed in the non-primary channel. The second non-primary channel may be a secondary channel remaining after excluding the first non-primary channel from the Basic Service Set (BSS) operation channel of the first AP.

[0337] FIG. 24 is a flowchart illustrating a procedure for determining whether a non-AP STA according to the present embodiment will perform NPCA based on MU EDCA parameters.

[0338] 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, 802.11bn or next wi-fi). The next-generation wireless LAN system is a wireless LAN system that improves upon the 802.11be system and can satisfy backward compatibility with the 802.11be system.

[0339] This embodiment proposes a method for determining whether to perform channel access to a non-primary channel based on MU EDCA parameters to resolve the problem that the determination of whether the BSS primary channel is BUSY / IDLE between the AP and the non-AP STA may differ due to hidden node issues, etc. Additionally, this embodiment proposes a method for determining whether to perform channel access to the non-primary channel by having the AP directly transmit information regarding the OBSS AP list or trigger-based NPCA mode to the non-AP STA.

[0340] In step S2410, the first non-AP (non-access point) STA (station) receives a management frame from the first AP.

[0341] In step S2420, the first non-AP STA determines whether to perform channel access by switching from the primary 20 MHz channel to the non-primary channel based on the management frame.

[0342] The above management frame includes MU (Multi User) EDCA (Enhanced Distributed Channel Access) parameters.

[0343] The above MU EDCA parameters include information regarding the contention window, information regarding the Arbitration Inter-Frame Space Number (AIFSN), and information regarding the MU EDCA timer.

[0344] The AIFSN is set to 0 until the MU EDCA timer expires, so that channel access to the non-primary channel is not allowed.

[0345] Information regarding the above-mentioned contention window, information regarding the above-mentioned AIFSN, and information regarding the above-mentioned MU EDCA timer may be defined per AC (Access Category). The above-mentioned AIFSN is a value that determines the length of the waiting time for channel access, but if the above-mentioned AIFSN is 0, EDCA becomes disabled for the corresponding AC, and this disabled state may persist until the above-mentioned MU EDCA timer expires. Information regarding the above-mentioned contention window may include information regarding the minimum or maximum value of the contention window (for the corresponding AC).

[0346] The above MU EDCA timer may be defined as the time to use the above MU EDCA parameter for the corresponding AC. That is, the management frame may further include the EDCA parameter. After the above MU EDCA timer expires, channel access to the non-primary channel may be performed based on the above EDCA parameter (returning to the existing EDCA parameter).

[0347] After switching from the primary 20 MHz channel to the non-primary channel (when NPCA operation begins), the first AP may transmit a basic trigger frame to the first non-AP STA. The first AP may receive a Quality of Service (QoS) frame from the first non-AP STA based on the basic trigger frame. The MU EDCA parameters may be used after receiving the QoS frame. (The first non-AP STA may receive a basic trigger frame from the first AP. The first non-AP STA may transmit a Quality of Service (QoS) frame to the first AP based on the basic trigger frame. The MU EDCA parameters may be used after transmitting the QoS frame.)

[0348] Additionally, before switching from the primary 20 MHz channel to the non-primary channel, the first AP may transmit a basic trigger frame to the first non-AP STA. The first AP may receive a Quality of Service (QoS) frame from the first non-AP STA based on the basic trigger frame. The MU EDCA parameters may be used after receiving the QoS frame. Even after switching from the primary 20 MHz channel to the non-primary channel, the MU EDCA parameters may be used in the same way. (The first non-AP STA may receive a basic trigger frame from the first AP. The first non-AP STA may transmit a QoS frame to the first AP based on the basic trigger frame. The MU EDCA parameters may be used after transmitting the QoS frame. The MU EDCA parameters may be used in the same way even after switching from the primary 20 MHz channel to the non-primary channel.)

[0349] That is, the present embodiment proposes a method for determining whether to perform channel access (or EDCA) on a non-primary channel using MU EDCA parameters when a Non-Primary Channel Access (NPCA) operation begins. Specifically, the present embodiment proposes a method for suspending or suspending channel access (or EDCA) on the non-primary channel until the MU EDCA timer expires by setting the AIFSN value among the MU EDCA parameters to 0, regardless of the value transmitted from the MU EDCA parameters. This has the effect of preventing meaningless operations where the AP performs channel access on the BSS primary channel and the non-AP STA performs channel access on the non-primary channel, as the judgment regarding whether the BSS primary channel is BUSY / IDLE differs between the AP and the non-AP STA. Furthermore, it has the effect of preventing unnecessary media access and frame transmission attempts by non-AP STAs, thereby allowing for expected performance improvement in terms of power consumption.

[0350] After switching from the primary 20 MHz channel to the non-primary channel, the first AP can transmit an ICF (Initial Control Frame) to the first non-AP STA. The first AP can receive an ICR (Initial Control Response) from the first non-AP STA. (The first non-AP STA can receive an ICF (Initial Control Frame) from the first AP. The first non-AP STA can transmit an ICR (Initial Control Response) to the first AP.) Even if the AIFSN is set to 0 before the MU EDCA timer expires, channel access to the non-primary channel can be initiated based on the ICF. That is, when the first AP transmits the ICF, the first non-AP STA can perform channel access (or NPCA) to the non-primary channel under the control of the first AP.

[0351] The above non-primary channel may be a secondary channel capable of performing backoff while a Basic Network Allocation Vector (NAV) set by Overlapping Basic Service Set (OBSS) traffic is set on the above primary 20 MHz channel.

[0352] For example, the above OBSS traffic may be traffic transmitted and received between the second AP and the second non-AP STA. The second AP may be an OBSS AP with respect to the first AP. The second non-AP STA may be an OBSS non-AP STA within the Basic Service Set (BSS) of the second AP.

[0353] In addition, the present embodiment proposes a method for determining whether to perform channel access to the non-primary channel by having the AP directly transmit information regarding the OBSS AP list or trigger-based NPCA mode to the non-AP STA.

[0354] For example, the first AP may transmit information regarding an OBSS (Overlapping Basic Service Set) AP list to the first non-AP STA. Based on the fact that the information regarding the OBSS AP list includes information regarding OBSS traffic, the first AP may perform channel access by switching from the primary 20 MHz channel to the non-primary channel. (The first non-AP STA may receive information regarding the OBSS (Overlapping Basic Service Set) AP list from the first AP. Based on the fact that the information regarding the OBSS AP list includes information regarding OBSS traffic, the first non-AP STA may perform channel access by switching from the primary 20 MHz channel to the non-primary channel.)

[0355] The above OBSS AP list may include information regarding BSS color, information regarding BSSID (Basic Service Set Identifier), and information regarding UL (uplink) or DL ​​(downlink) traffic. The information regarding BSS color may include the BSS color for the OBSS traffic. The information regarding BSSID may include the BSSID for the OBSS traffic. The information regarding UL or DL ​​traffic may include information regarding whether the OBSS traffic is UL traffic or DL ​​traffic.

[0356] As another example, the first AP may transmit information regarding a trigger-based Non-Primary Channel Access (NPCA) mode to the first non-AP STA. The first AP may determine whether to perform trigger-based channel access on the non-primary channel based on the information regarding the trigger-based NPCA mode. (The first non-AP STA may receive information regarding the trigger-based Non-Primary Channel Access (NPCA) mode from the first AP. The first non-AP STA may determine whether to perform trigger-based channel access on the non-primary channel based on the information regarding the trigger-based NPCA mode.)

[0357] Based on the above trigger-based NPCA mode being set to a first value (e.g., 0), channel access based on the trigger is performed on the non-primary channel, and the first AP can become a TXOP (Transmission Opportunity) holder. That is, the NPCA can be performed based on the trigger of the first AP.

[0358] Based on the fact that the trigger-based NPCA mode is set to a second value (e.g., 1), channel access based on the trigger is not performed in the non-primary channel, and the first AP or the first non-AP STA can become the TXOP holder. That is, the first AP or the first non-AP STA can perform the NPCA by acquiring the TXOP based on competition according to the existing EDCA rule.

[0359] The above management frame may be a Beacon, a Probe response frame, or a (Re)Association response frame. Information regarding the OBSS AP list or the trigger-based NPCA mode may be included in the above management frame.

[0360] The first non-AP STA can perform backoff for the first non-primary channel. If the value of the backoff for the first non-primary channel is 0, the first non-AP STA can perform channel access for the second non-primary channel. The first non-AP STA can transmit or receive a PPDU (Physical Protocol Data Unit) through the IDLE channel among the first and second non-primary channels.

[0361] The first and second non-primary channels may be included in the non-primary channels. The first non-primary channel may be a secondary 20 MHz channel where the backoff is performed in the non-primary channel. The second non-primary channel may be a secondary channel remaining after excluding the first non-primary channel from the Basic Service Set (BSS) operation channel of the first AP.

[0362] <Device Configuration>

[0363] The technical features of the specification described above may be applied to various devices and methods. For example, the technical features of the specification described above may be performed / supported through the device of FIG. 1 and / or FIG. 14. For example, the technical features of the specification described above may be applied only to parts of FIG. 1 and / or FIG. 14. For example, the technical features of the specification described above may 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 specification receives a management frame from a first AP (access point); and determines whether to perform channel access by switching from a primary 20 MHz channel to a non-primary channel based on the management frame.

[0364] The technical features of this specification may be implemented based on a computer-readable medium (CRM). For example, the CRM proposed by this specification is at least one computer-readable medium comprising instructions based on execution by at least one processor.

[0365] The above CRM may store instructions for performing operations including the step of receiving a management frame from a first AP (access point); and the step of determining whether to perform channel access by switching from a primary 20 MHz channel to a non-primary channel based on the management frame. Instructions stored in the CRM of this specification may be executed by at least one processor. At least one processor associated with the CRM of this specification may be the processor (111, 121) or processing chip (114, 124) of FIG. 1, or the processor (610) of FIG. 14. Meanwhile, the CRM of this 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.

[0366] The technical features of the present specification described above are applicable to various applications or business models. For example, the technical features described above may be applied for wireless communication in devices supporting Artificial Intelligence (AI).

[0367] Artificial intelligence refers to the field of researching artificial intelligence or the methodologies to create it, while machine learning refers to the field of researching methodologies to define and solve various problems addressed within the field of artificial intelligence. Machine learning is also defined as an algorithm that improves performance on a task through continuous experience.

[0368] An Artificial Neural Network (ANN) is a model used in machine learning that can refer to any model capable of problem-solving, composed of artificial neurons (nodes) that form a network through the connection of synapses. An artificial neural network can be defined by connection patterns between neurons in different layers, a learning process that updates model parameters, and an activation function that generates output values.

[0369] An artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer may include one or more neurons, and the artificial neural network may include synapses connecting the neurons. In an artificial neural network, each neuron may output a function value of an activation function for input signals, weights, and biases input through the synapses.

[0370] Model parameters refer to parameters determined through learning, including synaptic connection weights and neuron biases. Hyperparameters, on the other hand, refer to parameters that must be set prior to training in a machine learning algorithm, including the learning rate, number of iterations, mini-batch size, and initialization function.

[0371] The objective of training an artificial neural network can be viewed as determining model parameters that minimize the loss function. The loss function can be used as an indicator to determine optimal model parameters during the training process of an artificial neural network.

[0372] Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning depending on the learning method.

[0373] Supervised learning refers to a method of training an artificial neural network with labels provided for the training data; a label can refer to the correct answer (or result) that the neural network must infer when the training data is input. Unsupervised learning refers to a method of training an artificial neural network without labels provided for the training data. Reinforcement learning refers to a learning method in which an agent defined within an environment is trained to select an action or sequence of actions that maximizes the cumulative reward in each state.

[0374] Machine learning implemented using a Deep Neural Network (DNN) that includes multiple hidden layers among artificial neural networks is also called Deep Learning, and Deep Learning is a part of Machine Learning. Hereinafter, Machine Learning is used in a sense that includes Deep Learning.

[0375] In addition, the aforementioned technical features can be applied to the wireless communication of robots.

[0376] A robot can refer to a machine that automatically processes or operates a given task based on its own capabilities. In particular, a robot that has the ability to perceive its environment, make decisions on its own, and perform actions can be called an intelligent robot.

[0377] Robots can be classified into industrial, medical, domestic, and military types depending on their purpose or field of use. Robots are equipped with drive units, including actuators or motors, to perform various physical movements, such as moving robot joints. Additionally, mobile robots include wheels, brakes, and propellers in their drive units, enabling them to drive on the ground or fly in the air.

[0378] In addition, the aforementioned technical features can be applied to devices that support augmented reality.

[0379] Extended Reality is a collective term for Virtual Reality (VR), Augmented Reality (AR), and Mixed Reality (MR). VR technology provides real-world objects or backgrounds solely as CG images, AR technology provides virtual CG images superimposed on real-world images, and MR technology is a computer graphics technology that mixes and combines virtual objects with the real world.

[0380] MR technology is similar to AR technology in that it displays real-world objects and virtual objects together. However, there is a difference in that while virtual objects in AR technology are used to complement real-world objects, virtual objects and real-world objects are used as equals in MR technology.

[0381] XR technology can be applied to HMDs (Head-Mount Displays), HUDs (Head-Up Displays), mobile phones, tablet PCs, laptops, desktops, TVs, digital signage, etc., and devices to which XR technology is applied can be called XR devices.

[0382] The claims described in this specification may be combined in various ways. For example, the technical features of the method claims in this specification may be combined to be implemented as a device, and the technical features of the device claims in this specification may be combined to be implemented as a method. Furthermore, the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a device, and the technical features of the method claims and the technical features of the device claims in this specification may be combined to be implemented as a method.

Claims

1. In a wireless LAN system, A first non-AP (non-access point) STA (station) receiving a management frame from the first AP; and The above-mentioned first non-AP STA includes a step of determining whether to perform channel access by switching from a primary 20 MHz channel to a non-primary channel based on the management frame, wherein The above management frame includes MU (Multi User) EDCA (Enhanced Distributed Channel Access) parameters, and The above MU EDCA parameters include information regarding the contention window, information regarding the AIFSN (Arbitration Inter-Frame Space Number), and information regarding the MU EDCA timer, and By setting the AIFSN to 0 until the MU EDCA timer expires, channel access to the non-primary channel is not allowed method.

2. In Paragraph 1, After switching from the primary 20 MHz channel to the non-primary channel, The first non-AP STA receives a basic trigger frame from the first AP; and The above first non-AP STA further includes the step of transmitting a Quality of Service (QoS) frame to the first AP based on the basic trigger frame, wherein The above MU EDCA parameters are used after transmitting the above QoS frame. method.

3. In Paragraph 1, Before switching from the primary 20 MHz channel to the non-primary channel, The first non-AP STA receives a basic trigger frame from the first AP; and The above first non-AP STA further includes the step of transmitting a QoS frame to the first AP based on the basic trigger frame, wherein The above MU EDCA parameters are used after transmitting the above QoS frame, and Even after switching from the primary 20 MHz channel to the non-primary channel, the MU EDCA parameters are used identically method.

4. In Paragraph 1, The above management frame further includes EDCA parameters, and After the above MU EDCA timer expires, channel access to the non-primary channel is performed based on the above EDCA parameters. method.

5. In Paragraph 1, After switching from the primary 20 MHz channel to the non-primary channel, The first non-AP STA receives an ICF (Initial Control Frame) from the first AP; and The above first non-AP STA further includes the step of transmitting an ICR (Initial Control Response) to the first AP, wherein Even if the AIFSN is set to 0 before the MU EDCA timer expires, channel access to the non-primary channel is initiated based on the ICF method.

6. In Paragraph 1, The above non-primary channel is a secondary channel capable of performing backoff while a basic NAV (Network Allocation Vector) configured by OBSS (Overlapping Basic Service Set) traffic is configured on the above primary 20 MHz channel, and The above OBSS traffic is traffic transmitted and received between the second AP and the second non-AP STA, and The above second AP is an OBSS AP with respect to the above first AP, and The above second non-AP STA is an OBSS non-AP STA within the BSS (Basic Service Set) of the above second AP. method.

7. In Paragraph 6, The first non-AP STA receives information regarding an OBSS (Overlapping Basic Service Set) AP list from the first AP; and Based on the fact that information regarding the OBSS AP list includes information regarding the OBSS traffic, the first non-AP STA further includes the step of performing channel access by switching from the primary 20 MHz channel to the non-primary channel, wherein The above OBSS AP list includes information regarding BSS Color, information regarding BSSID (Basic Service Set Identifier), and information regarding UL (uplink) or DL ​​(downlink) traffic, and The information regarding the above BSS color includes the BSS color for the above OBSS traffic, and The information regarding the above BSSID includes the BSSID for the above OBSS traffic, and The information regarding the above UL or DL ​​traffic includes information regarding whether the above OBSS traffic is UL traffic or DL ​​traffic. method.

8. In Paragraph 1, The first non-AP STA receives information regarding a trigger-based NPCA (Non-Primary Channel Access) mode from the first AP; and The above first non-AP STA further includes a step of determining whether to perform trigger-based channel access on the non-primary channel based on information regarding the trigger-based NPCA mode, wherein Based on the above trigger-based NPCA mode being set to a first value, channel access is performed based on the trigger in the above non-primary channel, and the first AP becomes a TXOP (Transmission Opportunity) holder, and Based on the above trigger-based NPCA mode being set to a second value, channel access based on the trigger is not performed on the above non-primary channel, and the first AP or the first non-AP STA becomes the TXOP holder. method.

9. In Paragraph 1, Information regarding the above competition window, information regarding the above AIFSN, and information regarding the above MU EDCA timer are defined by AC (Access Category), and The information regarding the above competition window includes information regarding the minimum or maximum value of the competition window. method.

10. In Paragraph 1, The above first non-AP STA performs a backoff for the first non-primary channel; The first non-AP STA performs channel access for the second non-primary channel when the value of the backoff for the first non-primary channel is 0; and The above-mentioned first non-AP STA includes the step of transmitting or receiving a PPDU (Physical Protocol Data Unit) through an IDLE channel among the first and second non-primary channels, wherein The first and second non-primary channels are included in the non-primary channels, and The first non-primary channel is a secondary 20 MHz channel in which the backoff is performed in the non-primary channel, and The second non-primary channel is the remaining secondary channel excluding the first non-primary channel from the BSS (Basic Service Set) operation channel of the first AP. method.

11. In a wireless LAN system, the first non-AP (non-access point) STA (station) is, Memory; transceiver; and The processor comprises the memory and the transceiver, operably coupled thereto, wherein the processor comprises: A first non-AP (non-access point) STA (station) receives a management frame from the first AP; and The above first non-AP STA determines whether to perform channel access by switching from the primary 20 MHz channel to the non-primary channel based on the management frame, The above management frame includes MU (Multi User) EDCA (Enhanced Distributed Channel Access) parameters, and The above MU EDCA parameters include information regarding the contention window, information regarding the AIFSN (Arbitration Inter-Frame Space Number), and information regarding the MU EDCA timer, and By setting the AIFSN to 0 until the MU EDCA timer expires, channel access to the non-primary channel is not allowed 1st non-AP STA.

12. In wireless LAN systems, The first AP (access point) transmits a management frame to the first non-AP (non-access point) STA (station); and The above first AP includes a step of determining whether to perform channel access by switching from a primary 20 MHz channel to a non-primary channel based on the management frame, wherein The above management frame includes MU (Multi User) EDCA (Enhanced Distributed Channel Access) parameters, and The above MU EDCA parameters include information regarding the contention window, information regarding the AIFSN (Arbitration Inter-Frame Space Number), and information regarding the MU EDCA timer, and By setting the AIFSN to 0 until the MU EDCA timer expires, channel access to the non-primary channel is not allowed method.

13. In Paragraph 12, After switching from the primary 20 MHz channel to the non-primary channel, The first AP transmits a basic trigger frame to the first non-AP STA; and The above first AP further includes the step of receiving a Quality of Service (QoS) frame from the first non-AP STA based on the basic trigger frame, wherein The above MU EDCA parameter is used after receiving the above QoS frame. method.

14. In Paragraph 12, Before switching from the primary 20 MHz channel to the non-primary channel, The first AP transmits a basic trigger frame to the first non-AP STA; and The above first AP further includes the step of receiving a QoS frame based on the basic trigger frame from the above first non-AP STA, wherein The above MU EDCA parameters are used after receiving the above QoS frame, and Even after switching from the primary 20 MHz channel to the non-primary channel, the MU EDCA parameters are used identically method.

15. In Paragraph 12, The above management frame further includes EDCA parameters, and After the above MU EDCA timer expires, channel access to the non-primary channel is performed based on the above EDCA parameters. method.

16. In Paragraph 12, After switching from the primary 20 MHz channel to the non-primary channel, The first AP transmits an Initial Control Frame (ICF) to the first non-AP STA; and The above first AP further includes the step of receiving an ICR (Initial Control Response) from the above first non-AP STA, wherein Even if the AIFSN is set to 0 before the MU EDCA timer expires, channel access to the non-primary channel is initiated based on the ICF method.

17. In Paragraph 12, The above non-primary channel is a secondary channel capable of performing backoff while a basic NAV (Network Allocation Vector) configured by OBSS (Overlapping Basic Service Set) traffic is configured on the above primary 20 MHz channel, and The above OBSS traffic is traffic transmitted and received between the second AP and the second non-AP STA, and The above second AP is an OBSS AP with respect to the above first AP, and The above second non-AP STA is an OBSS non-AP STA within the BSS (Basic Service Set) of the above second AP. method.

18. In a wireless LAN system, the first AP (access point) is, Memory; transceiver; and The processor comprises the memory and the transceiver, operably coupled thereto, wherein the processor comprises: Transmitting a management frame to the first non-AP (non-access point) STA (station); and The first AP determines whether to perform channel access by switching from a primary 20 MHz channel to a non-primary channel based on the management frame, The above management frame includes MU (Multi User) EDCA (Enhanced Distributed Channel Access) parameters, and The above MU EDCA parameters include information regarding the contention window, information regarding the AIFSN (Arbitration Inter-Frame Space Number), and information regarding the MU EDCA timer, and By setting the AIFSN to 0 until the MU EDCA timer expires, channel access to the non-primary channel is not allowed 1st AP.

19. At least one computer-readable medium comprising an instruction based on execution by at least one processor, A step of receiving a management frame from a first AP (access point); and The method includes a step of determining whether to perform channel access by switching from a primary 20 MHz channel to a non-primary channel based on the above management frame, wherein The above management frame includes MU (Multi User) EDCA (Enhanced Distributed Channel Access) parameters, and The above MU EDCA parameters include information regarding the contention window, information regarding the AIFSN (Arbitration Inter-Frame Space Number), and information regarding the MU EDCA timer, and By setting the AIFSN to 0 until the MU EDCA timer expires, channel access to the non-primary channel is not allowed Recording media.

20. In a device in a wireless LAN system, Memory; and The processor comprises the above memory and operablely coupled thereto, wherein the processor is: Receive a management frame from the first AP (access point); and Determine whether to perform channel access by switching from the primary 20 MHz channel to the non-primary channel based on the above management frame, The above management frame includes MU (Multi User) EDCA (Enhanced Distributed Channel Access) parameters, and The above MU EDCA parameters include information regarding the contention window, information regarding the AIFSN (Arbitration Inter-Frame Space Number), and information regarding the MU EDCA timer, and By setting the AIFSN to 0 until the MU EDCA timer expires, channel access to the non-primary channel is not allowed device.

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