Method and apparatus for transmitting and receiving merged physical layer protocol data units in a wireless LAN system

Abstract

A method and an apparatus operating in a wireless LAN system are disclosed. According to an embodiment of the present disclosure, the method performed by a first STA in the wireless LAN system includes: receiving a specific PPDU including a plurality of S-PPDUs from a second STA; and decoding a first S-PPDU received in a primary 160 MHz channel among the plurality of S-PPDUs, the first S-PPDU including information indicating that the specific PPDU is an A-PPDU, the specific PPDU including a second S-PPDU among the plurality of S-PPDUs and a first pre-padding field in a first secondary 160 MHz channel or a secondary 320 MHz channel, the length of the first pre-padding field may be a length from an L-STF included in the first S-PPDU to an HE-SIG-B field or an EHT-SIG field.

Description

[Technical Field]

[0001] The present disclosure relates to communication operations in wireless local area network (WLAN) systems, and more particularly to an aggregated physical layer protocol data unit (PPDU) transmission and reception method and apparatus in next generation WLAN systems. [Background technology]

[0002] New technologies have been introduced to wireless LANs (WLANs) to improve transmission rates, increase bandwidth, improve reliability, reduce errors, and decrease latency. Among WLAN technologies, the IEEE (Institute of Electrical and Electronics Engineers) 802.11 series of standards can be referred to as Wi-Fi. For example, technologies recently introduced to WLANs include enhancements to the 802.11ac standard for Very High-Throughput (VHT) and the IEEE 802.11ax standard for High Efficiency (HE).

[0003] To provide a more improved wireless communication environment, improved technologies for Extremely High Throughput (EHT) are being discussed. For example, technologies for increased bandwidth, efficient use of multiple bands, and multiple input multiple output (MIMO) that support increased spatial streams, and multiple access point (AP) coordination are being researched. In particular, various technologies for supporting traffic with low latency or real-time characteristics are being researched. In addition, new technologies for supporting ultra-high reliability (UHR), including improvements or extensions to EHT technology, are being discussed. Summary of the Invention [Problem to be solved by the invention]

[0004] A technical problem to be solved by the present disclosure is to provide a method and apparatus for transmitting and receiving an A (aggregated)-PPDU in a wireless LAN system.

[0005] A further technical object of the present disclosure is to provide a structure of an A-PPDU configured in the 480 MHz / 640 MHz band in a wireless LAN system.

[0006] A further technical problem of the present disclosure is to provide a method and apparatus for decoding an A-PPDU including a pre-padding field.

[0007] The technical problems to be solved by the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the following description. [Means for solving the problem]

[0008] A method for performing communication by a first station (STA) in a wireless LAN system according to one embodiment of the present disclosure includes: receiving a specific PPDU including a plurality of sub-physical layer protocol data units (S-PPDUs) from a second STA; and decoding a first S-PPDU among the plurality of S-PPDUs received in a primary 160 MHz channel, the first S-PPDU including information indicating that the specific PPDU is an A (aggregated)-PPDU, wherein the specific PPDU includes a second S-PPDU among the plurality of S-PPDUs and a first pre-padding field in a first secondary 160 MHz channel or a secondary 320 MHz channel, and the length of the first pre-padding field may be a length from an L (legacy)-STF (short training field) included in the first S-PPDU to an HE (high throughput)-SIG-B field or an EHT (extremely high throughput)-SIG field.

[0009] A method for performing communication by a second station (STA) in a wireless LAN system according to a further aspect of the present disclosure includes the steps of generating a specific PPDU including a plurality of sub-physical layer protocol data units (S-PPDUs) and transmitting the specific PPDU to at least one STA including a first STA, wherein the specific PPDU includes a first S-PPDU among the plurality of S-PPDUs in a primary 160 MHz channel and a second S-PPDU among the plurality of S-PPDUs and a first pre-padding field in a first secondary 160 MHz channel or a secondary 320 MHz channel, the first S-PPDU including information indicating that the specific PPDU is an A (aggregated)-PPDU, and the length of the first pre-padding field may be from an L (legacy)-STF (short training field) included in the first S-PPDU to an HE (high throughput)-SIG-B field or an EHT (extremely high throughput)-SIG field. [Effects of the Invention]

[0010] Various embodiments of the present disclosure can provide a method and apparatus for transmitting and receiving an A (aggregated)-PPDU in a wireless LAN system.

[0011] Various embodiments of the present disclosure can provide an A-PPDU structure configured in the 480 MHz / 640 MHz band in a wireless LAN system.

[0012] Various embodiments of the present disclosure may provide a method and apparatus for decoding an A-PPDU that includes a pre-padding field.

[0013] The effects obtained from the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present disclosure pertains from the following description. [Brief explanation of the drawings]

[0014] The accompanying drawings, which are included as part of the detailed description to aid in understanding the present disclosure, provide examples for the present disclosure and, together with the detailed description, explain the technical features of the present disclosure.

[0015] [Figure 1] 1 is a block diagram illustrating a wireless communication device according to an embodiment of the present disclosure. [Figure 2] FIG. 1 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure can be applied. [Figure 3] FIG. 1 is a diagram illustrating a link setup process to which the present disclosure can be applied. [Figure 4] FIG. 10 is a diagram illustrating a backoff process to which the present disclosure can be applied. [Figure 5] 10A and 10B are diagrams for explaining a CSMA / CA base frame transmission operation to which the present disclosure can be applied. [Figure 6] 1 is a diagram illustrating an example of a frame structure used in a wireless LAN system to which the present disclosure can be applied. [Figure 7] FIG. 1 illustrates an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure is applicable. [Figure 8] FIG. 1 is a diagram illustrating an example of a resource unit of a wireless LAN system to which the present disclosure can be applied. [Figure 9] FIG. 1 is a diagram illustrating an example of a resource unit of a wireless LAN system to which the present disclosure can be applied. [Figure 10] FIG. 1 is a diagram illustrating an example of a resource unit of a wireless LAN system to which the present disclosure can be applied. [Figure 11] FIG. 1 illustrates an exemplary structure of an HE-SIG-B field. [Figure 12] FIG. 1 is a diagram illustrating a MU-MIMO scheme in which multiple users / STAs are assigned to one RU. [Figure 13] FIG. 10 is a diagram illustrating an example of a PPDU format to which the present disclosure can be applied. [Figure 14] FIG. 10 is a diagram illustrating an example of an A-PPDU format to which the present disclosure can be applied. [Figure 15] 10 is a diagram for explaining an operation performed by a first STA according to an embodiment of the present disclosure. [Figure 16] FIG. 10 is a diagram for explaining an operation performed by a second STA according to an embodiment of the present disclosure. [Figure 17] FIG. 10 is a diagram illustrating an example of an A-PPDU format to which the present disclosure can be applied. [Figure 18] 1 is a diagram illustrating a PPDU transmission / reception procedure between a transmitting STA and a receiving STA according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0016] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. The detailed description disclosed below together with the accompanying drawings is intended to describe exemplary embodiments of the present disclosure and is not intended to represent the only embodiments in which the present disclosure can be implemented. The detailed description below includes specific details to provide a complete understanding of the present disclosure. However, it will be understood by those skilled in the art that the present disclosure can be implemented without such specific details.

[0017] In some cases, in order to avoid obscuring the concepts of the present disclosure, known structures and devices may be omitted or shown in block diagram form, focusing on the core functions of each structure and device.

[0018] In this disclosure, when a component is "coupled," "coupled," or "connected" to another component, this may include a direct connection as well as an indirect connection where there is another component between them. Also, in this disclosure, the terms "comprise" or "have" specify the presence of stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0019] In this disclosure, terms such as "first" and "second" are used only to distinguish one component from another, and are not used to limit the components, and do not limit the order or importance of the components unless otherwise specified. Therefore, within the scope of this disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0020] The terms used in this disclosure are for the purpose of describing particular embodiments and are not intended to limit the scope of the claims. As used in the description of the embodiments and the appended claims, the singular is intended to include the plural unless the context clearly dictates otherwise. The term "and / or" as used in this disclosure means that one of the associated listed items may be included, or that any and all possible combinations of two or more of them are included. Also, in this disclosure, " / " between words has the same meaning as "and / or" unless otherwise specified.

[0021] The examples of the present disclosure may be applied to various wireless communication systems. For example, the examples of the present disclosure may be applied to a wireless LAN system. For example, the examples of the present disclosure may be applied to an IEEE 802.11a / g / n / ac / ax standard-based wireless LAN. Note that the examples of the present disclosure may be applied to a newly proposed IEEE 802.11be (or EHT) standard-based wireless LAN. The examples of the present disclosure may be applied to an IEEE 802.11be Release-2 standard-based wireless LAN, which corresponds to a further improvement technology of the IEEE 802.11be Release-1 standard. Furthermore, the examples of the present disclosure may be applied to a next-generation standard-based wireless LAN after IEEE 802.11be. The examples of the present disclosure may also be applied to a cellular wireless communication system. For example, the examples of the present disclosure may be applied to a cellular wireless communication system based on the Long Term Evolution (LTE) series technology and the 5G New Radio (NR) series technology of the 3GPP (registered trademark) standard.

[0022] Below, technical features to which the examples of the present disclosure can be applied will be described.

[0023] FIG. 1 is a block diagram illustrating a wireless communication device according to an embodiment of the present disclosure.

[0024] 1 may be referred to by various terms such as a terminal, a wireless device, a wireless transmit receive unit (WTRU), a user equipment (UE), a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a mobile subscriber unit (MSS), a subscriber station (SS), an advanced mobile station (AMS), a wireless terminal (WT), or simply a user. In addition, the first device 100 and the second device 200 may be referred to by various terms such as an access point (AP), a base station (BS), a fixed station, a Node B, a base transceiver system (BTS), a network, an artificial intelligence (AI) system, a road side unit (RSU), a repeater, a router, a relay, a gateway, etc.

[0025] The devices 100 and 200 illustrated in FIG. 1 may also be referred to as stations (STAs). For example, the devices 100 and 200 illustrated in FIG. 1 may be referred to by various terms, such as a transmitting device, a receiving device, a transmitting STA, or a receiving STA. For example, the STAs 110 and 200 may serve as an access point (AP) or a non-AP. That is, in the present disclosure, the STAs 110 and 200 may have AP and / or non-AP functionality. When the STAs 110 and 200 have AP functionality, they may simply be referred to as APs, and when the STAs 110 and 200 have non-AP functionality, they may simply be referred to as STAs. Also, in the present disclosure, an AP may be referred to as an AP STA.

[0026] 1, a first device 100 and a second device 200 may transmit and receive wireless signals using various wireless LAN technologies (e.g., the IEEE 802.11 family). The first device 100 and the second device 200 may include interfaces for a medium access control (MAC) layer and a physical layer (PHY) in accordance with the IEEE 802.11 standard.

[0027] In addition, the first device 100 and the second device 200 may further support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, etc.) other than WLAN technology. Furthermore, the devices of the present disclosure may be embodied as various devices such as mobile phones, vehicles, personal computers, augmented reality (AR) equipment, and virtual reality (VR) equipment. Furthermore, the STAs of the present disclosure may support various communication services such as voice calls, video calls, data communications, autonomous driving, machine-type communication (MTC), machine-to-machine (M2M), device-to-device (D2D), and Internet-of-Things (IoT).

[0028] The first device 100 includes one or more processors 102 and one or more memories 104, and may additionally include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may be configured to control the memory 104 and / or the transceiver 106 to implement the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts of the present disclosure. For example, the processor 102 may process information in the memory 104 to generate first information / signals, and then transmit a wireless signal including the first information / signals via the transceiver 106. The processor 102 may also receive a wireless signal including second information / signals via the transceiver 106, and then store information obtained from signal processing of the second information / signals in the memory 104. The memory 104 may be coupled to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software code including instructions for executing some or all of the processes controlled by the processor 102 or for implementing the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts in this disclosure. Here, the processor 102 and the memory 104 may be part of a communications modem / circuit / chip designed to implement wireless LAN technology (e.g., the IEEE 802.11 series). The transceiver 106 may be coupled to the processor 102 and may transmit and / or receive wireless signals via one or more antennas 108. The transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used interchangeably with an RF (Radio Frequency) unit. In this disclosure, a device may also refer to a communications modem / circuit / chip.

[0029] The second device 200 includes one or more processors 202, one or more memories 204, and may additionally include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may be configured to control the memory 204 and / or the transceiver 206 to implement the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in this disclosure. For example, the processor 202 may process information in the memory 204 to generate third information / signal, and then transmit a wireless signal including the third information / signal via the transceiver 206. The processor 202 may also receive a wireless signal including fourth information / signal via the transceiver 206, and then store information obtained from signal processing of the fourth information / signal in the memory 204. The memory 204 may be coupled to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may store software code including instructions for executing some or all of the processes controlled by the processor 202 or for implementing the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in this disclosure. Here, the processor 202 and the memory 204 may be part of a communications modem / circuit / chip designed to implement wireless LAN technology (e.g., the IEEE 802.11 series). The transceiver 206 may be coupled to the processor 202 and may transmit and / or receive wireless signals via one or more antennas 208. The transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used interchangeably with an RF unit. In this disclosure, a device may also refer to a communications modem / circuit / chip.

[0030] The hardware elements of the devices 100 and 200 are described in more detail below. Without limitation, one or more protocol layers may be implemented by one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., the same functional layer, such as PHY or MAC). The one or more processors 102 and 202 may generate one or more protocol data units (PDUs) and / or one or more service data units (SDUs) according to the descriptions, functions, procedures, suggestions, methods, and / or operational flow diagrams in this disclosure. The one or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or operational flow diagrams in this disclosure. The one or more processors 102, 202 can generate and provide signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, procedures, suggestions, and / or methods of this disclosure to the one or more transceivers 106, 206. The one or more processors 102, 202 can receive signals (e.g., baseband signals) from the one or more transceivers 106, 206 and obtain the PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts of this disclosure.

[0031] The one or more processors 102, 202 may be referred to as a controller, microcontroller, microprocessor, or microcomputer. The one or more processors 102, 202 may be implemented using hardware, firmware, software, or a combination thereof. As an example, the one or more processors 102, 202 may include one or more application-specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field programmable gate arrays (FPGAs). The descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in this disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. Firmware or software configured to execute the descriptions, functions, procedures, suggestions, methods, and / or operational flow diagrams disclosed in this disclosure may be included in one or more processors 102, 202 or stored in one or more memories 104, 204 and executed by one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods, and / or operational flow diagrams disclosed in this disclosure may be embodied by firmware or software in the form of code, instructions, and / or collections of instructions.

[0032] One or more memories 104, 204 may be coupled to one or more processors 102, 202 and may store various types of data, signals, messages, information, programs, code, instructions, and / or instructions. The one or more memories 104, 204 may be comprised of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories 104, 204 may be located internal and / or external to the one or more processors 102, 202. Additionally, the one or more memories 104, 204 may be coupled to the one or more processors 102, 202 via various techniques, such as wired or wireless connections.

[0033] One or more transceivers 106, 206 may transmit user data, control information, wireless signals / channels, etc., as referred to in the methods and / or operational flowcharts of the present disclosure, to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc., as referred to in the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts of the present disclosure, from one or more other devices. For example, one or more transceivers 106, 206 may be coupled to one or more processors 102, 202 and may transmit and receive wireless signals. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Also, one or more processors 102, 202 may control one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. Furthermore, one or more transceivers 106, 206 may be coupled to one or more antennas 108, 208, and the one or more transceivers 106, 206 may be configured to transmit and receive user data, control information, wireless signals / channels, etc., referred to in the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in this disclosure, via the one or more antennas 108, 208. In this disclosure, the one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). The one or more transceivers 106, 206 may convert the received user data, control information, wireless signals / channels, etc., from RF band signals to baseband signals for processing using one or more processors 102, 202. The one or more transceivers 106, 206 may convert the user data, control information, wireless signals / channels, etc., processed using one or more processors 102, 202, from baseband signals to RF band signals. To that end, one or more of the transceivers 106, 206 may include (analog) oscillators and / or filters.

[0034] For example, one of the STAs 100 and 200 may perform operations intended for an AP, and the other of the STAs 100 and 200 may perform operations intended for a non-AP STA. For example, the transceivers 106 and 206 in FIG. 1 may perform operations for transmitting and receiving signals (e.g., packets or PPDUs (Physical Layer Protocol Data Units) conforming to IEEE 802.11a / b / g / n / ac / ax / be, etc.). In addition, in the present disclosure, operations for various STAs to generate transmission / reception signals or to perform data processing or calculations in advance for transmission / reception signals may be performed by the processors 102 and 202 in FIG. 1. For example, examples of operations for generating transmission / reception signals or performing data processing or calculations in advance for transmission / reception signals may include: 1) operations for determining / obtaining / configuring / calculating / decoding / encoding bit information of fields included in a PPDU (SIG (signal), STF (short training field), LTF (long training field), Data, etc.); 2) operations for determining / configuring / obtaining time resources and frequency resources (e.g., subcarrier resources) to be used for fields included in a PPDU (SIG, STF, LTF, Data, etc.); 3) operations for determining / configuring / obtaining specific sequences (e.g., pilot sequences, STF / LTF sequences, extra sequences applied to SIG) to be used for fields included in a PPDU (SIG, STF, LTF, Data, etc.); 4) power control operations and / or power saving operations applied to STAs; and 5) operations related to determining / obtaining / configuring / calculating / decoding / encoding ACK signals, etc. In addition, in the example below, various information (e.g., information regarding fields / subfields / control fields / parameters / power, etc.) used by various STAs to determine / acquire / configure / calculate / decode / encode transmitted / receive signals may be stored in memories 104, 204 of FIG. 1.

[0035] Hereinafter, downlink (DL) refers to a link for communication from an AP STA to a non-AP STA, and downlink PPDUs / packets / signals, etc. may be transmitted and received via the downlink. In downlink communication, the transmitter may be part of the AP STA, and the receiver may be part of the non-AP STA. Uplink (UL) refers to a link for communication from a non-AP STA to an AP STA, and uplink PPDUs / packets / signals, etc. may be transmitted and received via the uplink. In uplink communication, the transmitter may be part of the non-AP STA, and the receiver may be part of the AP STA.

[0036] FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0037] The structure of a WLAN system may be composed of multiple components. The interaction of these components may provide a WLAN that supports STA mobility transparent to higher layers. A Basic Service Set (BSS) is a basic building block of a WLAN. FIG. 2 illustrates two BSSs (BSS1 and BSS2), each including two STAs as members (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). The ellipses representing BSSs in FIG. 2 may be understood to represent coverage areas where STAs included in the BSSs maintain communication. This area may be referred to as a Basic Service Area (BSA). If a STA moves outside a BSA, it will no longer be able to directly communicate with other STAs within the BSA.

[0038] Ignoring the DS shown in FIG. 2, the most basic type of BSS in a WLAN is the Independent BSS (IBSS). For example, an IBSS may have a minimal configuration consisting of only two STAs. For example, assuming that other components are omitted, BSS1 consisting of only STA1 and STA2, or BSS2 consisting of only STA3 and STA4, are representative examples of an IBSS. Such a configuration is possible when STAs can communicate directly without an AP. Furthermore, in such a WLAN, a BSS may be configured when needed by the LAN, rather than being configured in advance. This can also be called an ad-hoc network. Since an IBSS does not include an AP, there is no centralized management entity. That is, in an IBSS, STAs are managed in a distributed manner. In an IBSS, all STAs may be mobile, and connection to a distributed system (DS) is not permitted, forming a self-contained network.

[0039] The membership of STAs in a BSS may change dynamically as STAs join and leave the BSS area, etc. To become a member of a BSS, a STA may join the BSS using a synchronization process. To access all the services of the BSS-based architecture, a STA must be associated with the BSS. Such association may be dynamically configured and may include the use of a Distribution System Service (DSS).

[0040] In a wireless LAN, direct STA-to-STA distance may be limited by PHY performance. While such distance limits are sufficient in some cases, other situations may require communication between STAs over longer distances. To support extended coverage, a distributed system (DS) may be configured.

[0041] A DS refers to a structure in which BSSs are interconnected. Specifically, as shown in FIG. 2, a BSS may exist as a component of an expanded network composed of multiple BSSs. A DS is a logical concept and may be specified by the characteristics of a distributed system medium (DSM). In this regard, a wireless medium (WM) and a DSM may be logically distinguished. Each logical medium is used for different purposes and by different components. These media are neither limited to being the same nor limited to being different. The flexibility of a WLAN structure (DS structure or other network structure) can be explained by the fact that multiple media are logically distinct from one another. That is, a WLAN structure may be embodied in various ways, and the WLAN structure may be independently specified according to the physical characteristics of each implementation.

[0042] The DS can support mobile devices by providing seamless integration of multiple BSSs and logical services necessary for addressing destinations. The DS may also include a portal component that acts as a bridge between the wireless LAN and other networks (e.g., IEEE 802.X).

[0043] An AP is an entity that allows associated non-AP STAs to access the DS through the WM and also has the functionality of an STA. Data can be transferred between a BSS and a DS via the AP. For example, STA2 and STA3 shown in FIG. 2 have the functionality of an STA and provide the function of allowing associated non-AP STAs (STA1 and STA4) to access the DS. Furthermore, since all APs essentially correspond to STAs, all APs are addressable entities. The address used by an AP for communication on the WM does not necessarily have to be the same as the address used by the AP for communication on the DSM. A BSS consisting of an AP and one or more STAs can be called an infrastructure BSS.

[0044] Data transmitted from one of the STAs associated with an AP to the STA address of that AP is always received on the uncontrolled port and may be processed by the IEEE 802.1X port access entity, and once the controlled port is authenticated, the transmitted data (or frame) may be delivered to the DS.

[0045] In the above-described DS structure, an Extended Service Set (ESS) may be configured to provide wider coverage.

[0046] An ESS is a network of arbitrary size and complexity composed of a DS and a BSS. An ESS can be a collection of BSSs connected to one DS. However, an ESS does not include a DS. An ESS network is characterized by appearing as an IBSS at the Logical Link Control (LLC) layer. STAs included in an ESS can communicate with each other, and mobile STAs can move from one BSS to another (within the same ESS) transparently to the LLC. APs included in one ESS may have the same service set identification (SSID). An SSID is distinct from a BSSID, which is an identifier for a BSS.

[0047] A WLAN system does not make any assumptions about the relative physical locations of BSSs and can have any of the following configurations: BSSs may partially overlap, which is a configuration commonly used to provide continuous coverage; BSSs may not be physically connected, and there is no logical limit to the distance between BSSs; BSSs may be physically located in the same location, which may be used to provide redundancy; and one (or more) IBSS or ESS networks may physically exist in the same space as one (or more) ESS networks. This may apply to ESS network configurations when an ad-hoc network operates in the location where the ESS network exists, when physically overlapping wireless networks are formed by different organizations, or when two or more different access and security policies are required in the same location.

[0048] FIG. 3 is a diagram illustrating a link setup process to which the present disclosure can be applied.

[0049] In order for an STA to set up a link to a network and transmit and receive data, it must first discover the network, perform authentication, establish an association, and perform authentication procedures for security. The link setup process can also be called a session initiation process or a session setup process. In addition, the discovery, authentication, association, and security configuration processes of the link setup process can also be collectively called the association process.

[0050] In step S310, the STA may perform a network discovery operation. The network discovery operation may include a scanning operation of the STA. That is, in order for the STA to access a network, the STA must search for a joinable network. Before joining a wireless network, the STA must identify a compatible network. The process of identifying networks present in a specific area is called scanning.

[0051] Scanning methods include active scanning and passive scanning. FIG. 3 illustrates an example of a network discovery operation including an active scanning process. In active scanning, a scanning STA changes channels and transmits a probe request frame to search for nearby APs, and waits for a response. A responder transmits a probe response frame to the STA that transmitted the probe request frame in response to the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame in the BSS of the channel being scanned. In a BSS, the AP transmits beacon frames, so the AP is the responder. In an IBSS, the STAs in the IBSS transmit beacon frames alternately, so the responder is not constant. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 can store the BSS-related information contained in the received probe response frame, move to the next channel (e.g., channel 2), and perform scanning in the same manner (i.e., send and receive probe requests / responses on channel 2).

[0052] Although not shown in FIG. 3, the scanning operation may be performed in a passive scanning manner. In passive scanning, the scanning STA waits for a beacon frame while changing channels. A beacon frame is one of the management frames defined in IEEE 802.11. It is transmitted periodically to announce the existence of a wireless network and allow the scanning STA to search for and join the wireless network. In a BSS, the AP is responsible for periodically transmitting beacon frames, while in an IBSS, the STAs within the IBSS transmit beacon frames in turn. When a scanning STA receives a beacon frame, it saves the BSS information contained in the beacon frame and records the beacon frame information on each channel as it moves to other channels. A STA that receives a beacon frame saves the BSS-related information contained in the received beacon frame, moves to the next channel, and scans the next channel in the same manner. Comparing active scanning with passive scanning, active scanning has the advantage of having a smaller delay and power consumption than passive scanning.

[0053] After the STA discovers the network, an authentication process may be performed in step S320. This authentication process may be called a first authentication process to clearly distinguish it from the security setup operation in step S340, which will be described later.

[0054] The authentication process involves a STA sending an authentication request frame to an AP, and the AP responding by sending an authentication response frame to the STA. The authentication frame used for the authentication request / response corresponds to a management frame.

[0055] The authentication frame may include information such as an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a Robust Security Network (RSN), a Finite Cyclic Group, etc. These are only examples of information that may be included in an authentication request / response frame, and other information may be substituted or additional information may be included.

[0056] The STA can send an authentication request frame to the AP. The AP can determine whether to allow authentication for the STA based on the information contained in the received authentication request frame. The AP can provide the STA with the result of the authentication process using an authentication response frame.

[0057] After the STA is successfully authenticated, an association process may be performed in step S330. The association process includes a process in which the STA transmits an association request frame to the AP, and in response, the AP transmits an association response frame to the STA.

[0058] For example, the association request frame may include information on various capabilities, a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, an RSN, a mobility domain, supported operating classes, a Traffic Indication Map Broadcast request, interworking service capabilities, etc. For example, the association response frame may include information on various capabilities, a status code, an association ID (AID), supported rates, an Enhanced Distributed Channel Access (EDCA) parameter set, a Received Channel Power Indicator (RCPI), a Received Signal to Noise Indicator (RSNI), a mobility domain, a timeout interval (e.g., an association comeback time), overlapping BSS scan parameters, a TIM broadcast response, a Quality of Service (QoS) map, etc. This corresponds to only a partial example of information that may be included in the association request / response frame, and other information may be substituted or additional information may be included.

[0059] After the STA is successfully connected to the network, a security setup process may be performed in step S340. The security setup process in step S340 may also be referred to as an authentication process using a Robust Security Network Association (RSNA) request / response, and the authentication process in step S320 may be referred to as a first authentication process, and the security setup process in step S340 may simply be referred to as an authentication process.

[0060] The security setup process of step S340 may include a process of performing private key setup using, for example, four-way handshaking using an Extensible Authentication Protocol over LAN (EAPOL) frame, and may also be performed using a security method not defined in the IEEE 802.11 standard.

[0061] FIG. 4 is a diagram illustrating a backoff process to which the present disclosure can be applied.

[0062] In wireless LAN systems, the basic access mechanism of MAC (Medium Access Control) is the Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) mechanism, also known as the Distributed Coordination Function (DCF) of IEEE 802.11 MAC, which basically employs a "listen before talk" access mechanism. According to this type of access mechanism, the AP and / or STA can perform a Clear Channel Assessment (CCA) to sense the wireless channel or medium for a predetermined time period (e.g., a DCF Inter-Frame Space (DIFS)) before starting transmission. If the sensing result indicates that the medium is in an idle status, the AP and / or STA can start transmitting a frame over the medium. On the other hand, if the medium is detected as occupied or busy, the AP and / or STA can wait for a delay period (e.g., a random backoff period) for medium access without starting its own transmission, and then attempt to transmit a frame. By applying the random backoff period, multiple STAs are expected to wait for different periods of time before attempting to transmit a frame, thereby minimizing collisions.

[0063] The IEEE 802.11 MAC protocol also provides a Hybrid Coordination Function (HCF). HCF is based on the DCF and Point Coordination Function (PCF). PCF is a polling-based synchronous access method that periodically polls all receiving APs and / or STAs to ensure that they can receive data frames. HCF also includes Enhanced Distributed Channel Access (EDCA) and HCF Controlled Channel Access (HCCA). EDCA is a contention-based access method for a provider to provide data frames to multiple users, while HCCA is a non-contention-based channel access method using a polling mechanism. HCF also includes a medium access mechanism for improving the Quality of Service (QoS) of wireless LANs, and can transmit QoS data in both a contention period (CP) and a contention-free period (CFP).

[0064] The operation based on the random backoff period will be described with reference to FIG. 4. When an occupied / busy medium changes to an idle state, multiple STAs can attempt to transmit data (or frames). As a method for minimizing collisions, each STA can select a random backoff count and attempt transmission after waiting for the corresponding slot time. The random backoff count has a pseudo-random integer value and may be determined to be one of the values ​​in the range of 0 to CW. Here, CW is the contention window parameter value. The CW parameter is given a CWmin as its initial value, but can be doubled in the event of a transmission failure (e.g., if an ACK for a transmitted frame is not received). When the CW parameter value reaches CWmax, data transmission can be attempted while maintaining the CWmax value until data transmission is successful, and if data transmission is successful, it is reset to the CWmin value. The CW, CWmin, and CWmax values ​​are set to 2. n Preferably it is set to -1 (n=0,1,2,...).

[0065] When the random backoff process begins, the STA continuously monitors the medium while counting down the backoff slots according to the determined backoff count value. If the medium is monitored as occupied, the STA stops counting down and waits. If the medium becomes idle, the STA resumes the remaining countdown.

[0066] In the example of FIG. 4, when a packet to be transmitted arrives at the MAC of STA3, STA3 confirms that the medium is idle for DIFS and can immediately transmit a frame. The remaining STAs monitor the medium for occupied / busy status and wait. Meanwhile, STA1, STA2, and STA5 may each have data to transmit. If each STA monitors the medium as idle, it waits for DIFS and then counts down its backoff slots according to its random backoff count value. Assume that STA2 selects the smallest backoff count value and STA1 selects the largest backoff count value. That is, this example illustrates a case where, at the time STA2 finishes its backoff count and begins frame transmission, STA5's remaining backoff time is shorter than STA1's remaining backoff time. STA1 and STA5 pause their countdowns and wait while STA2 occupies the medium. When STA2's occupation ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and then resume their backoff counts. That is, STA5 can start frame transmission after counting down the remaining backoff slots equal to the remaining backoff time. Because STA5's remaining backoff time is shorter than STA1's, STA5 begins frame transmission. While STA2 is occupying the medium, STA4 may also have data to transmit. From STA4's perspective, when the medium becomes idle, it waits for DIFS, then counts down the random backoff count value it selected, and can begin frame transmission. The example in FIG. 4 shows a case where STA5's remaining backoff time happens to match STA4's random backoff count value, which may result in a collision between STA4 and STA5. If a collision occurs, neither STA4 nor STA5 will receive an ACK, resulting in a failed data transmission. In this case, STA4 and STA5 can double their CW values, select a random backoff count value, and then count down.STA1 waits while the medium is occupied by transmissions from STA4 and STA5, but when the medium becomes idle, it waits for DIFS and can begin frame transmission once the remaining backoff time has elapsed.

[0067] As shown in the example of Figure 4, a data frame is a frame used for transmitting data to be forwarded to a higher layer, and may be transmitted after a backoff that occurs after a DIFS has elapsed since the medium became idle. Furthermore, a management frame is a frame used for exchanging management information that is not forwarded to a higher layer, and is transmitted after a backoff that occurs after an IFS, such as a DIFS or a PIFS (Point Coordination Function IFS). Subtype frames of management frames include a beacon, an association request / response, a re-association request / response, a probe request / response, and an authentication request / response. A control frame is a frame used to control access to a medium. Subtype frames of control frames include Request-To-Send (RTS), Clear-To-Send (CTS), Acknowledgment (ACK), Power Save-Poll (PS-Poll), BlockAck, BlockACKReq, NDP announcement (null data packet announcement), and Trigger. If a control frame is not a response frame of a previous frame, it is transmitted after a backoff that is performed after a DIFS has elapsed. If a control frame is a response frame of a previous frame, it is transmitted without a backoff after a short IFS (SIFS) has elapsed. The type and subtype of a frame may be identified by the type field and subtype field in the Frame Control (FC) field.

[0068] A Quality of Service (QoS) STA can transmit a frame after backing off after the arbitration IFS (AIFS) for the access category (AC) to which the frame belongs, i.e., AIFS[i] (where i is a value determined by the AC), has elapsed. Here, a frame that can use AIFS[i] can be a data frame, a management frame, or a control frame that is not a response frame.

[0069] FIG. 5 is a diagram for explaining a CSMA / CA base frame transmission operation to which the present disclosure can be applied.

[0070] As mentioned above, the CSMA / CA mechanism includes not only physical carrier sensing, in which a STA directly senses the medium, but also virtual carrier sensing. Virtual carrier sensing is intended to compensate for problems that may occur in medium access, such as the hidden node problem. For virtual carrier sensing, the MAC of a STA can use a network allocation vector (NAV). The NAV is a value that indicates to other STAs the time remaining until the medium becomes available for use by a STA currently using or authorized to use the medium. Therefore, the value set as the NAV corresponds to the period during which the STA transmitting the frame plans to use the medium, and STAs receiving the NAV value are prohibited from accessing the medium during that period. For example, the NAV may be set based on the value of the "duration" field in the MAC header of the frame.

[0071] In the example of FIG. 5, it is assumed that STA1 is attempting to transmit data to STA2, and STA3 is in a position where it can overhear some or all of the frames transmitted between STA1 and STA2.

[0072] In order to reduce the possibility of collisions between transmissions from multiple STAs in a CSMA / CA-based frame transmission operation, a mechanism using RTS / CTS frames may be applied. In the example of FIG. 5, while STA1 is transmitting, STA3 may determine that the medium is idle as a result of carrier sensing. That is, STA1 may be a hidden node to STA3. Alternatively, in the example of FIG. 5, while STA2 is transmitting, STA3 may determine that the medium is idle as a result of carrier sensing. That is, STA2 may be a hidden node to STA3. By exchanging RTS / CTS frames before data transmission and reception between STA1 and STA2, STAs outside the transmission range of either STA1 or STA2, or outside the carrier sensing range for transmissions from STA1 or STA3, can be prevented from attempting to occupy the channel during data transmission and reception between STA1 and STA2.

[0073] Specifically, STA1 can determine whether a channel is occupied or not using carrier sensing. In terms of physical carrier sensing, STA1 can determine whether a channel is occupied or idle based on the energy magnitude or signal correlation detected from the channel. In terms of virtual carrier sensing, STA1 can determine whether a channel is occupied or idle using a network allocation vector (NAV) timer.

[0074] When the channel is idle in DIFS, STA1 can send an RTS frame to STA2 after backing off. When STA2 receives the RTS frame, it can send a CTS frame to STA1 as a response to the RTS frame after SIFS.

[0075] If STA3 cannot overhear the CTS frame from STA2 but can overhear the RTS frame from STA1, STA3 can use the duration information included in the RTS frame to set a NAV timer for the frame transmission period (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame) that will be transmitted subsequently. Alternatively, if STA3 cannot overhear the RTS frame from STA1 but can overhear the CTS frame from STA2, STA3 can use the duration information included in the CTS frame to set a NAV timer for the frame transmission period (e.g., SIFS + data frame + SIFS + ACK frame) that will be transmitted subsequently. That is, if STA3 can overhear one or more RTS or CTS frames from at least one of STA1 and STA2, it can set a NAV based thereon. If STA3 receives a new frame before the NAV timer expires, it can update the NAV timer using the duration information included in the new frame. STA3 does not attempt channel access until the NAV timer expires.

[0076] When STA1 receives a CTS frame from STA2, it can transmit a data frame to STA2 SIFS after the completion of reception of the CTS frame. When STA2 successfully receives a data frame, it can transmit an ACK frame, which is a response to the data frame, to STA1 SIFS after the completion of reception of the CTS frame. When STA2 successfully receives a data frame, it can transmit an ACK frame, which is a response to the data frame, to STA1 SIFS after the expiration of the NAV timer. When STA3 determines that the channel is not being used by another terminal during the DIFS period after the expiration of the NAV timer, it can attempt channel access after the contention window (CW) with random backoff has elapsed.

[0077] FIG. 6 is a diagram illustrating an example of a frame structure used in a wireless LAN system to which the present disclosure can be applied.

[0078] The PHY layer can prepare an MPDU (MAC PDU) to be transmitted based on an instruction or primitive (meaning a set of instructions or parameters) from the MAC layer. For example, when the PHY layer receives a command from the MAC layer requesting the start of PHY layer transmission, the PHY layer switches to transmission mode and transmits information (e.g., data) provided by the MAC layer in the form of a frame. In addition, when the PHY layer detects a valid preamble in a received frame, it monitors the preamble header and sends a command to the MAC layer informing the start of PHY layer reception.

[0079] Thus, information transmission / reception in a wireless LAN system is performed in the form of frames, and for this purpose, a PHY layer protocol data unit (PPDU) frame format is defined.

[0080] A basic PPDU frame may include a Short Training Field (STF), a Long Training Field (LTF), a Signal (SIG) field, and a Data field. The most basic (e.g., non-High Throughput (HT)) PPDU frame format may consist of only a Legacy-STF (L-STF), a Legacy-LTF (L-LTF), a SIG field, and a Data field. Depending on the type of PPDU frame format (e.g., HT-mixed format PPDU, HT-greenfield format PPDU, Very High Throughput (VHT) PPDU, etc.), additional (or other types of) STF, LTF, and SIG fields may be included between the SIG field and the Data field (this will be described later with reference to FIG. 7).

[0081] The STF is a signal for signal detection, AGC (Automatic Gain Control), diversity selection, precise time synchronization, etc., and the LTF is a signal for channel estimation, frequency error estimation, etc. The STF and LTF can be said to be signals for synchronization and channel estimation of the OFDM physical layer.

[0082] The SIG field may include a RATE field, a LENGTH field, etc. The RATE field may include information about the modulation and coding rate of the data. The LENGTH field may include information about the length of the data. Furthermore, the SIG field may include a parity bit, a SIG TAIL bit, etc.

[0083] The data field may include a SERVICE field, a PSDU (Physical layer Service Data Unit), a PPDU TAIL bit, and, if necessary, padding bits. Some bits of the SERVICE field may be used for synchronization of a descrambler at the receiving end. The PSDU corresponds to a MAC PDU defined in the MAC layer and may contain data generated / used by a higher layer. The PPDU TAIL bit may be used to return the encoder to a 0 state. The padding bits may be used to adjust the length of the data field to a predetermined unit.

[0084] The MAC PDU is defined by various MAC frame formats, and a basic MAC frame consists of a MAC header, a frame body, and a Frame Check Sequence (FCS). The MAC frame is composed of the MAC PDU and may be transmitted / received by the PSDU in the data portion of the PPDU frame format.

[0085] The MAC header includes a Frame Control field, a Duration / ID field, an Address field, etc. The Frame Control field may include control information required for frame transmission / reception. The Duration / ID field may be set to the time for transmitting the frame, etc. For specific contents of the Sequence Control, QoS Control, and HT Control subfields of the MAC header, please refer to the IEEE 802.11 standard document.

[0086] The null data packet (NDP) frame format refers to a frame format that does not include a data packet. That is, the NDP frame refers to a frame format that includes a PLCP (physical layer convergence procedure) header portion (i.e., STF, LTF, and SIG fields) in a general PPDU frame format, but does not include the remaining portion (i.e., data field). The NDP frame can also be referred to as a short frame format.

[0087] FIG. 7 is a diagram illustrating an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure is applicable.

[0088] Various types of PPDUs are used in standards such as IEEE 802.11a / g / n / ac / ax. The basic PPDU format (IEEE 802.11a / g) includes an L-LTF, an L-STF, an L-SIG, and a Data field. The basic PPDU format can also be called a non-HT PPDU format.

[0089] The HT PPDU format (IEEE 802.11n) further includes HT-SIG, HT-STF, and HT-LFT(s) fields in addition to the basic PPDU format. The HT PPDU format shown in Fig. 7 may be referred to as an HT-mixed format. An HT-greenfield format PPDU may also be defined, which corresponds to a format that does not include L-STF, L-LTF, or L-SIG, but is composed of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs, and a Data field (not shown).

[0090] An example of a VHT PPDU format (IEEE 802.11ac) further includes VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields in addition to the basic PPDU format.

[0091] An example of the HE PPDU format (IEEE 802.11ax) further includes the fields Repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), and Packet Extension (PE) in addition to the basic PPDU format. Depending on the detailed example of the HE PPDU format, some fields may be excluded or their lengths may vary. For example, the HE-SIG-B field is included in the HE PPDU format for multiple users (MU), but not in the HE PPDU format for single users (SU). Also, the HE trigger-based (TB) PPDU format does not include the HE-SIG-B, and the length of the HE-STF field may be 8 us. The HE Extended Range (ER) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may be 16 us.

[0092] 8 to 10 are diagrams illustrating examples of resource units in a wireless LAN system to which the present disclosure can be applied.

[0093] 8 to 10, a resource unit (RU) defined in a wireless LAN system will be described. An RU may include multiple subcarriers (or tones). An RU may be used when transmitting signals to multiple STAs based on the OFDMA technique. An RU may also be defined when transmitting a signal to one STA. An RU may be used for the STF, LTF, data field, etc. of a PPDU.

[0094] 8 to 10, RUs corresponding to different numbers of tones (i.e., subcarriers) may be used to configure some fields of a 20 MHz, 40 MHz, or 80 MHz X-PPDU (X is HE, EHT, etc.). For example, resources may be allocated in units of RUs indicated for the X-STF, X-LTF, and Data fields.

[0095] FIG. 8 is a diagram illustrating an exemplary arrangement of resource units (RUs) used on a 20 MHz band.

[0096] As shown at the top of Figure 8, 26 units (i.e., units corresponding to 26 tones) may be allocated. 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. Seven DC tones may be inserted into the center band, i.e., the DC band, leaving 26 units corresponding to 13 tones on each side of the DC band. Other bands may be allocated 26 units, 52 units, or 106 units. Each unit may be allocated for a STA or a user.

[0097] The RU arrangement in Figure 8 can be utilized not only in a multiple user (MU) situation but also in a single user (SU) situation, in which case one 242 unit can be used as shown at the bottom of Figure 8. In this case, three DC tones may be inserted.

[0098] In the example of Figure 8, RUs of various sizes, i.e., 26-RU, 52-RU, 106-RU, 242-RU, etc., are illustrated, but the specific sizes of such RUs may be reduced or expanded. Therefore, the specific size of each RU (i.e., the corresponding number of tones) is not limited in the present disclosure and is merely exemplary. Also, in the present disclosure, the number of RUs within a given bandwidth (e.g., 20, 40, 80, 160, 320 MHz, ...) may vary depending on the size of the RU. The examples of Figures 9 and / or 10 described below are the same as the example of Figure 8 in that the size and / or number of RUs may be changed.

[0099] FIG. 9 is a diagram illustrating an exemplary arrangement of resource units (RUs) used on a 40 MHz band.

[0100] Just as various sizes of RUs are used in the example of Figure 8, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. may be used in the example of Figure 9. In addition, five DC tones may be inserted at the center frequency, 12 tones may be used as a guard band in the leftmost band of the 40 MHz band, and 11 tones may be used as a guard band in the rightmost band of the 40 MHz band.

[0101] Also, as shown in the figure, when used for a single user, 484-RU may be used.

[0102] FIG. 10 is a diagram illustrating an exemplary arrangement of resource units (RUs) used on an 80 MHz band.

[0103] Just as various sizes of RUs are used in the examples of Figures 8 and 9, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc. may be used in the example of Figure 10. Furthermore, in an 80 MHz PPDU, the RU arrangements of the HE PPDU and the EHT PPDU may differ from each other, and the example of Figure 10 shows an example of the RU arrangement for an 80 MHz EHT PPDU. In the example of Figure 10, the HE PPDU and the EHT PPDU are the same in that 12 tones are used as a guard band in the leftmost band of the 80 MHz band and 11 tones are used as a guard band in the rightmost band of the 80 MHz band. In the HE PPDU, seven DC tones are inserted into the DC band, and there are two 26-RUs on each side of the DC band, corresponding to 13 tones. In the EHT PPDU, 23 DC tones are inserted into the DC band, and there are two 26-RUs on each side of the DC band. In the HE PPDU, there is one null subcarrier between the 242-RUs outside the center band. In the EHT PPDU, there are five null subcarriers. In the HE PPDU, one 484-RU does not contain a null subcarrier, but in the EHT PPDU, one 484-RU contains five null subcarriers.

[0104] Also, as shown in the figure, when used for a single user, 996-RU may be used, and in this case, five DC tones are inserted, which is common to both the HE PPDU and the EHT PPDU.

[0105] An EHT PPDU of 160 MHz or more may be configured with multiple 80 MHz sub-blocks in Figure 10. The RU allocation for each 80 MHz sub-block may be the same as the RU allocation for the 80 MHz EHT PPDU in Figure 10. When the 80 MHz sub-blocks of a 160 MHz or 320 MHz EHT PPDU are not punctured and the entire 80 MHz sub-block is used as part of an RU or MRU (Multiple RU), the 80 MHz sub-block can use 996 RUs in Figure 10.

[0106] Here, an MRU corresponds to a group of subcarriers (or tones) composed of multiple RUs, and the multiple RUs constituting an MRU may be RUs of the same size or different sizes. For example, a single MRU may be defined as 52+26-tones, 106+26-tones, 484+242-tones, 996+484-tones, 996+484+242-tones, 2×996+484-tones, 3×996-tones, or 3×996+484-tones. Here, the multiple RUs constituting one MRU may correspond to RUs of small size (e.g., 26, 52, 106) or RUs of large size (e.g., 242, 484, 996, etc.). That is, one MRU including RUs of small size and RUs of large size does not need to be configured / defined. Furthermore, the multiple RUs constituting one MRU may or may not be contiguous in the frequency domain.

[0107] If an 80 MHz sub-block contains RUs with fewer than 996 tones or if portions of the 80 MHz sub-block are punctured, the 80 MHz sub-block may use an RU placement that excludes 996-tone RUs.

[0108] The RUs of the present disclosure may be used for uplink (UL) and / or downlink (DL) communications. For example, when trigger-based UL-MU communications are performed, a STA (e.g., an AP) transmitting a trigger may use trigger information (e.g., a trigger frame or triggered response scheduling (TRS)) to assign a first RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a first STA and a second RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a second STA. The first STA may then transmit a first trigger-based (TB) PPDU based on the first RU, and the second STA may transmit a second TB PPDU based on the second RU. The first and second TB PPDUs may be transmitted to the AP in the same time interval.

[0109] For example, when a DL MU PPDU is configured, a STA (e.g., an AP) transmitting the DL MU PPDU can assign a first RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a first STA and a second RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a second STA. That is, the transmitting STA (e.g., an AP) can transmit the HE-STF, HE-LTF, and Data fields for the first STA using the first RU within one MU PPDU, and can transmit the HE-STF, HE-LTF, and Data fields for the second STA using the second RU.

[0110] Information about the location of the RU may be signaled in the HE-SIG-B in HE PPDU format.

[0111] FIG. 11 shows an example structure of the HE-SIG-B field.

[0112] As shown in the figure, the HE-SIG-B fields may include common fields and user-specific fields. When HE-SIG-B compression is applied (e.g., in the case of full-bandwidth MU-MIMO transmission), the common fields may not be included in the HE-SIG-B, and the HE-SIG-B content channel may include only user-specific fields. When HE-SIG-B compression is not applied, the common fields may be included in the HE-SIG-B.

[0113] The common field may include information regarding RU allocation (e.g., RU assignment, RUs allocated for MU-MIMO, number of MU-MIMO users (STAs), etc.).

[0114] The common field may include N*8 RU allocation subfields, where N is the number of subfields, and may have a value of 1 for a 20 or 40 MHz MU PPDU, 2 for an 80 MHz MU PPDU, 4 for a 160 MHz or 80+80 MHz MU PPDU, .... One 8-bit RU allocation subfield may indicate the size (26, 52, 106, etc.) and frequency location (or RU index) of the RUs included in the 20 MHz band.

[0115] For example, if the value of the 8-bit RU allocation subfield is 00000000, nine 26-RUs are arranged in order from the leftmost to the rightmost in the example of Figure 8; if the value is 00000001, seven 26-RUs and one 52-RU are arranged in order from the leftmost to the rightmost; and if the value is 00000010, five 26-RUs, one 52-RU, and two 26-RUs are arranged in order from the leftmost to the rightmost.

[0116] As a further example, if the value of the 8-bit RU allocation subfield is 01000y2y1y0, it may indicate that one 106-RU and five 26-RUs are arranged in order from the leftmost to the rightmost in the example of FIG. 8. In this case, multiple users / STAs may be allocated to the 106-RU using the MU-MIMO scheme. Specifically, up to eight users / STAs may be allocated to the 106-RU, and the number of users / STAs allocated to the 106-RU is determined based on the 3-bit information (i.e., y2y1y0). For example, if the 3-bit information (y2y1y0) corresponds to a decimal value N, the number of users / STAs allocated to the 106-RU may be N+1.

[0117] Basically, one user / STA may be assigned to each of multiple RUs, and different users / STAs may be assigned to different RUs. For RUs of a certain size or larger (e.g., 106, 242, 484, 996-tone, etc.), multiple users / STAs may be assigned to one RU, and the MU-MIMO scheme may be applied to the multiple users / STAs.

[0118] The set of user-specific fields contains information on how all users (STAs) of the PPDU decode their payloads. The user-specific fields may contain zero or more user block fields. A non-final user block field contains two user fields (i.e., information used for decoding at two STAs). A final user block field contains one or two user fields. The number of user fields may be indicated by the RU allocation subfield in HE-SIG-B, the number of symbols in HE-SIG-B, or the MU-MIMO user field in HE-SIG-A. The user-specific fields may be encoded separately or independently from the common fields.

[0119] FIG. 12 is a diagram illustrating the MU-MIMO scheme in which multiple users / STAs are assigned to one RU.

[0120] In the example of FIG. 12, it is assumed that the value of the RU allocation subfield is 01000010. This corresponds to the case where y2y1y0=010 in 01000y2y1y0. 010 corresponds to 2 in decimal (i.e., N=2), and can indicate that 3 (=N+1) users are allocated to one RU. In this case, one 106-RU and five 26-RUs may be arranged in order from the leftmost to the rightmost of a specific 20 MHz band / channel. Three users / STAs may be allocated to the 106-RU in a MU-MIMO manner. As a result, a total of eight users / STAs are allocated to the 20 MHz band / channel, and the user-specific field of the HE-SIG-B may include eight user fields (i.e., four user block fields). The eight user fields may be assigned to RUs as shown in FIG. 12.

[0121] The user fields may be configured based on two formats. The user fields for MU-MIMO allocation may be configured in a first format, and the user fields for non-MU-MIMO allocation may be configured in a second format. Referring to the example of FIG. 12, user fields 1 to 3 may be based on the first format, and user fields 4 to 8 may be based on the second format. The first format and the second format may contain bit information of the same length (e.g., 21 bits).

[0122] The user field of the first format (i.e., a format for MU-MIMO allocation) may be configured as follows: For example, among the total 21 bits of one user field, B0 to B10 include identification information of the user (e.g., STA-ID, AID, partial AID, etc.), B11 to B14 include spatial configuration information such as the number of spatial streams for the user, B15 to B18 include modulation and coding scheme (MCS) information applied to the data field of the PPDU, B19 is defined as a reserved field, and B20 may include coding type information (e.g., binary convolutional coding (BCC) or low-density parity check (LDPC)) applied to the data field of the PPDU.

[0123] The user field of the second format (i.e., a format for non-MU-MIMO allocation) may be configured as follows: For example, among the total 21 bits of one user field, B0 to B10 may include identification information of the user (e.g., STA-ID, AID, partial AID, etc.), B11 to B13 may include information on the number of spatial streams (NSTS) applied to the RU, B14 may include information indicating whether beamforming is enabled (or whether a beamforming steering matrix is ​​applied), B15 to B18 may include information on modulation and coding scheme (MCS) applied to the Data field of the PPDU, B19 may include information on whether dual carrier modulation (DCM) is enabled, and B20 may include information on a coding type (e.g., BCC or LDPC) applied to the Data field of the PPDU.

[0124] The MCS, MCS information, MCS index, MCS field, etc. used in the present disclosure may be represented as specific index values. For example, the MCS information may be represented as index 0 to index 11. The MCS information may include information about the constellation modulation type (e.g., BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, etc.) and information about the coding rate (e.g., 1 / 2, 2 / 3, 3 / 4, 5 / 6, etc.). The MCS information may omit information about the channel coding type (e.g., BCC or LDPC).

[0125] FIG. 13 shows an example of a PPDU format to which the present disclosure can be applied.

[0126] 13 may be referred to by various names such as EHT PPDU, transmit PPDU, receive PPDU, first type or Nth type PPDU, etc. For example, the PPDU or EHT PPDU of the present disclosure may be referred to by various names such as transmit PPDU, receive PPDU, first type or Nth type PPDU, etc. Furthermore, the EHT PPDU can be used in an EHT system and / or a new WLAN system that is an improvement over the EHT system.

[0127] The EHT MU PPDU in Figure 13 corresponds to a PPDU that carries one or more data (or PSDUs) for one or more users. That is, the EHT MU PPDU may be used for both SU transmission and MU transmission. For example, the EHT MU PPDU may correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0128] The EHT TB PPDU in Figure 13 omits the EHT-SIG compared to the EHT MU PPDU. A STA that receives a trigger for UL MU transmission (e.g., a trigger frame or TRS) can perform UL transmission based on the EHT TB PPDU format.

[0129] In the example of the EHT PPDU format in FIG. 13, L-STF to EHT-LTF correspond to a preamble or a physical preamble, and may be generated / transmitted / received / acquired / decoded in the physical layer.

[0130] The subcarrier frequency spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal SIGNAL), and EHT-SIG fields (these are referred to as pre-EHT modulated fields) may be defined as 312.5 kHz. The subcarrier frequency spacing of the EHT-STF, EHT-LTF, Data, and PE fields (these are referred to as EHT modulated fields) may be defined as 78.125 kHz. That is, the tone / subcarrier indexes of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG fields may be represented in units of 312.5 kHz, and the tone / subcarrier indexes of the EHT-STF, EHT-LTF, Data, and PE fields may be represented in units of 78.125 kHz.

[0131] The L-LTF and L-STF in FIG. 13 may be configured in the same manner as the corresponding fields of the PPDU described in FIGS.

[0132] The L-SIG field in FIG. 13 may be composed of 24 bits and may be used to communicate rate and length information. For example, the L-SIG field may include a 4-bit Rate field, a 1-bit Reserved bit, a 12-bit Length field, a 1-bit Parity field, and a 6-bit Tail field. For example, the 12-bit Length field may include 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 PPDU. For example, for a non-HT, HT, VHT, or EHT PPDU, the value of the Length field may be determined as a multiple of 3. For example, for an HE PPDU, the value of the Length field may be determined as a multiple of 3 + 1 or a multiple of 3 + 2.

[0133] For example, the transmitting STA may apply BCC encoding based on a coding rate of 1 / 2 to the 24-bit information in the L-SIG field. The transmitting STA may then obtain 48 BCC-coded bits. BPSK modulation may be applied to the 48 coded bits to generate 48 BPSK symbols. The transmitting STA may map the 48 BPSK symbols to positions excluding pilot subcarriers (e.g., subcarrier indexes −21, −7, +7, +21) and DC subcarriers (e.g., subcarrier index 0). Consequently, the 48 BPSK symbols may be mapped to subcarrier indexes −26 to −22, −20 to −8, −6 to −1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA may further map signals of {−1, −1, −1, 1} to subcarrier indexes {−28, −27, +27, +28}. The signal may be used for channel estimation for the frequency range corresponding to {-28, -27, +27, +28}.

[0134] The transmitting STA can generate an RL-SIG, which is generated identically to the L-SIG. BPSK modulation is applied to the RL-SIG. The receiving STA can determine whether the received PPDU is an HE PPDU or an EHT PPDU based on the presence of the RL-SIG.

[0135] A Universal SIG (U-SIG) may be inserted after the RL-SIG in Fig. 13. The U-SIG may be called various names such as a first SIG field, a first SIG, a first type SIG, a control signal, a control signal field, or a first (type) control signal.

[0136] The U-SIG may include N bits of information and may include information for identifying the type of EHT PPDU. For example, the U-SIG may be configured based on two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG may have a duration of 4 us, and the entire U-SIG may have a duration of 8 us. Each symbol of the U-SIG may be used to transmit 26 bits of information. For example, each symbol of the U-SIG may be transmitted and received based on 52 data tones and 4 pilot tones.

[0137] In the U-SIG (or U-SIG field), for example, A-bit information (e.g., 52 uncoded bits) may be transmitted. The first symbol of the U-SIG (e.g., U-SIG-1) transmits the first X-bit information (e.g., 26 uncoded bits) of the total A-bit information, and the second symbol of the U-SIG (e.g., U-SIG-2) transmits the remaining Y-bit information (e.g., 26 uncoded bits) of the total A-bit information. For example, the transmitting STA may obtain the 26 uncoded bits included in each U-SIG symbol. The transmitting STA may perform convolutional encoding (e.g., BCC encoding) based on a rate of R=½ to generate 52-coded bits and perform interleaving on the 52-coded bits. The transmitting STA may perform BPSK modulation on the interleaved 52-coded bits to generate 52 BPSK symbols assigned to each U-SIG symbol. One U-SIG symbol may be transmitted based on 56 tones (subcarriers) from subcarrier index -28 to subcarrier index +28, excluding DC index 0. The 52 BPSK symbols generated by the transmitting STA may be transmitted based on the remaining tones (subcarriers) excluding the pilot tones -21, -7, +7, and +21.

[0138] For example, the A-bit information (e.g., 52 un-coded bits) transmitted by the U-SIG may include a CRC field (e.g., a 4-bit field) and a tail field (e.g., a 6-bit field). The CRC field and tail field may be transmitted in the second symbol of the U-SIG. The CRC field may be generated based on the 26 bits allocated to the first symbol of the U-SIG and the remaining 16 bits in the second symbol excluding the CRC / tail field, and may be generated based on a conventional CRC calculation algorithm. The tail field may also be used to terminate the trellis of a convolutional decoder and may be set to 0, for example.

[0139] The A-bit information (e.g., 52 uncoded bits) transmitted by the U-SIG (or U-SIG field) can be divided into version-independent bits and version-dependent bits. For example, the size of the version-independent bits may be fixed or variable. For example, the version-independent bits may be assigned only to the first symbol of the U-SIG, or the version-independent bits may be assigned to both the first and second symbols of the U-SIG. For example, the version-independent bits and version-dependent bits may be referred to by various names, such as the first control bit and the second control bit.

[0140] For example, the version-independent bits of the U-SIG may include a 3-bit physical layer version identifier (PHY version identifier). For example, the 3-bit physical layer version identifier may include information about the physical layer version (PHY version) of the transmitted / received PPDU. For example, a first value of the 3-bit physical layer version identifier can indicate that the transmitted / received PPDU is an EHT PPDU. In other words, when transmitting an EHT PPDU, the transmitting STA can set the 3-bit physical layer version identifier to the first value. In other words, the receiving STA can determine that the received PPDU is an EHT PPDU based on the physical layer version identifier having the first value.

[0141] For example, the version independent bits of the U-SIG may include a 1-bit UL / DL flag field, where a first value of the 1-bit UL / DL flag field is associated with UL communication and a second value of the UL / DL flag field is associated with DL communication.

[0142] For example, the version-independent bits of the U-SIG may include information regarding the length of a transmission opportunity (TXOP) and information regarding a BSS color ID.

[0143] For example, when EHT PPDUs are divided into various types (e.g., EHT PPDUs associated with SU mode, EHT PPDUs associated with MU mode, EHT PPDUs associated with TB mode, EHT PPDUs associated with Extended Range transmission, etc.), information regarding the type of EHT PPDU may be included in the version-dependent bits of the U-SIG.

[0144] For example, the U-SIG may include information regarding 1) a bandwidth field containing information regarding the bandwidth, 2) a field containing information regarding the MCS technique applied to the EHT-SIG, 3) an indication field containing information regarding whether the DCM technique is applied to the EHT-SIG, 4) a field containing information regarding the number of symbols used for the EHT-SIG, 5) a field containing information regarding whether the EHT-SIG is generated across the entire band, 6) a field containing information regarding the type of EHT-LTF / STF, and 7) a field indicating the length of the EHT-LTF and the CP length.

[0145] Preamble puncturing may be applied to the PPDU in FIG. 13. Preamble puncturing may refer to the transmission of a PPDU in which no signal is present in one or more 20 MHz subchannels in the PPDU's bandwidth. Preamble puncturing may be applied to PPDUs transmitted to one or more users. For example, the resolution of preamble puncturing may be 20 MHz for EHT MU PPDUs in OFDMA transmissions with bandwidths greater than 40 MHz and in non-OFDMA transmissions with 80 MHz and 160 MHz bandwidths. In other words, puncturing of subchannels smaller than 242-tone RUs may not be allowed in the above cases. Also, the resolution of preamble puncturing may be 40 MHz for EHT MU PPDUs in non-OFDMA transmissions with a 320 MHz bandwidth. In other words, puncturing of subchannels smaller than 484-tone RUs may not be allowed in the 320 MHz bandwidth. Also, preamble puncturing may not be applied to the primary 20 MHz channel in the EHT MU PPDU.

[0146] For example, for an EHT MU PPDU, information about preamble puncturing may be included in the U-SIG and / or the EHT-SIG, e.g., a first field of the U-SIG may include information about the contiguous bandwidth of the PPDU, and a second field of the U-SIG may include information about preamble puncturing applied to the PPDU.

[0147] For example, the U-SIG and EHT-SIG may include information about preamble puncturing based on the following method: When the bandwidth of a PPDU exceeds 80 MHz, the U-SIGs may be individually configured in 80 MHz increments. For example, when the bandwidth of a PPDU is 160 MHz, the PPDU may include a first U-SIG for a first 80 MHz band and a second U-SIG for a second 80 MHz band. In this case, the first field of the first U-SIG may include information about the 160 MHz bandwidth, and the second field of the first U-SIG may include information about the preamble puncturing applied to the first 80 MHz band (i.e., information about the preamble puncturing pattern). Furthermore, the first field of the second U-SIG may include information about the 160 MHz bandwidth, and the second field of the second U-SIG may include information about the preamble puncturing applied to the second 80 MHz band (i.e., information about the preamble puncturing pattern). The EHT-SIG subsequent to the first U-SIG may include information regarding the preamble puncturing applied to the second 80 MHz band (i.e., information regarding the preamble puncturing pattern), and the EHT-SIG subsequent to the second U-SIG may include information regarding the preamble puncturing applied to the first 80 MHz band (i.e., information regarding the preamble puncturing pattern).

[0148] Additionally or alternatively, the U-SIG and the EHT-SIG may include information about preamble puncturing based on the following method: The U-SIG may include information about preamble puncturing for the entire band (i.e., information about the preamble puncturing pattern). That is, the EHT-SIG may not include information about preamble puncturing, and only the U-SIG may include information about preamble puncturing (i.e., information about the preamble puncturing pattern).

[0149] A U-SIG may be configured in 20 MHz units. For example, when an 80 MHz PPDU is configured, a U-SIG may be duplicated. That is, four identical U-SIGs may be included in the 80 MHz PPDU. PPDUs exceeding the 80 MHz bandwidth may contain different U-SIGs.

[0150] 13 may include control information for the receiving STA. The EHT-SIG may be transmitted in at least one symbol, and one symbol may have a length of 4 us. Information regarding the number of symbols used for the EHT-SIG may be included in the U-SIG.

[0151] The EHT-SIG may include the technical features of the HE-SIG-B described in Figures 11 and 12. For example, the EHT-SIG may include a common field and a user-specific field, similar to the example of Figure 8. The common field of the EHT-SIG may be omitted, and the number of user-specific fields may be determined based on the number of users.

[0152] 11, the common fields of the EHT-SIG and the user-specific fields of the EHT-SIG may be coded separately. One user block field included in the user-specific fields contains information for two user fields, but the last user block field included in the user-specific fields may contain one or two user fields. That is, one user block field of the EHT-SIG may contain up to two user fields. As in the example of FIG. 12, each user field may be associated with either a MU-MIMO allocation or a non-MU-MIMO allocation.

[0153] Similar to the example of FIG. 11, the common field of the EHT-SIG may include CRC bits and Tail bits, where the length of the CRC bits may be determined to be 4 bits, and the length of the Tail bits may be determined to be 6 bits and set to 000000.

[0154] 11, the common field of the EHT-SIG may include RU allocation information. The RU allocation information may refer to information about the locations of RUs to which multiple users (i.e., multiple receiving STAs) are assigned. The RU allocation information may be configured in units of 9 bits (or N bits).

[0155] A mode in which the common field of the EHT-SIG is omitted may be supported. The mode in which the common field of the EHT-SIG is omitted may be called a compressed mode. When the compressed mode is used, multiple users of the EHT PPDU (i.e., multiple receiving STAs) can decode the PPDU (e.g., the data field of the PPDU) based on non-OFDMA. That is, multiple users of the EHT PPDU can decode the PPDU (e.g., the data field of the PPDU) received in the same frequency band. When the non-compressed mode is used, multiple users of the EHT PPDU can decode the PPDU (e.g., the data field of the PPDU) based on OFDMA. That is, multiple users of the EHT PPDU can receive the PPDU (e.g., the data field of the PPDU) in different frequency bands from each other.

[0156] The EHT-SIG may be configured based on various MCS schemes. As described above, information about the MCS scheme applied to the EHT-SIG may be included in the U-SIG. The EHT-SIG may be configured based on the DCM scheme. The DCM scheme reuses the same signal on two subcarriers to provide an effect similar to frequency diversity, reducing interference and improving coverage. For example, modulation symbols using the same modulation scheme may be repeatedly mapped on available tones / subcarriers. For example, of the N data tones (e.g., 52 data tones) allocated for the EHT-SIG, modulation symbols using a specific modulation scheme (e.g., BPSK modulation symbols) may be mapped to the first consecutive half of the tones (e.g., the 1st to 26th tones), and modulation symbols using the same specific modulation scheme (e.g., BPSK modulation symbols) may be mapped to the remaining consecutive half of the tones (e.g., the 27th to 52nd tones). That is, the modulation symbol mapped to the 1st tone and the modulation symbol mapped to the 27th tone are the same.

[0157] As described above, information (e.g., a one-bit field) regarding whether the DCM technique is applied to the EHT-SIG may be included in the U-SIG. The EHT-STF of FIG. 13 may be used to improve automatic gain control (AGC) estimation in a MIMO or OFDMA environment. The EHT-LTF of FIG. 13 may be used to estimate the channel in a MIMO or OFDMA environment.

[0158] Information regarding the type of STF and / or LTF (including information regarding the GI (guard interval) applied to the LTF) may be included in the U-SIG field and / or EHT-SIG field of FIG. 13, for example.

[0159] The PPDU in FIG. 13 (ie, the EHT PPDU) may be configured based on the example of the RU arrangement in FIGS.

[0160] For example, an EHT PPDU transmitted on a 20 MHz band, i.e., a 20 MHz EHT PPDU, may be configured based on the RUs in Figure 8. That is, the RU locations of the EHT-STF, EHT-LTF, and data fields included in the EHT PPDU may be determined as shown in Figure 8. An EHT PPDU transmitted on a 40 MHz band, i.e., a 40 MHz EHT PPDU, may be configured based on the RUs in Figure 9. That is, the RU locations of the EHT-STF, EHT-LTF, and data fields included in the EHT PPDU may be determined as shown in Figure 9.

[0161] An EHT PPDU transmitted on the 80 MHz band, i.e., an 80 MHz EHT PPDU, may be configured based on the RU in Figure 10. That is, the RU locations of the EHT-STF, EHT-LTF, and data fields included in the EHT PPDU may be determined as shown in Figure 10. The tone-plan for 80 MHz in Figure 10 may correspond to two repetitions of the tone-plan for 40 MHz in Figure 9.

[0162] The tone plan for 160 / 240 / 320 MHz may be configured to repeat the pattern of FIG. 9 or FIG. 10 multiple times.

[0163] The PPDU in FIG. 13 may be identified as an EHT PPDU based on the following method.

[0164] A receiving STA can determine the type of a received PPDU as an EHT PPDU based on the following: 1) the first symbol after the L-LTF signal of the received PPDU is BPSK; 2) an RL-SIG in which the L-SIG of the received PPDU is repeated is detected; and 3) the result of applying modulo 3 arithmetic to the value of the Length field of the L-SIG of the received PPDU (i.e., the remainder when divided by 3) is detected as 0, the received PPDU may be determined to be an EHT PPDU. If the received PPDU is determined to be an EHT PPDU, the receiving STA can determine the type of EHT PPDU based on bit information included in the symbol after the RL-SIG in FIG. 13. In other words, the receiving STA can determine the type of a received PPDU as an EHT PPDU based on 1) the first symbol after the L-LTF signal, which is BSPK; 2) an RL-SIG that follows the L-SIG field and is identical to the L-SIG; and 3) an L-SIG including a Length field in which the result of applying modulo 3 arithmetic is set to 0.

[0165] For example, the receiving STA may determine that the type of the received PPDU is an HE PPDU based on the following: 1) the first symbol after the L-LTF signal is BPSK, 2) an RL-SIG in which the L-SIG is repeated is detected, and 3) the result of applying modulo 3 to the Length value of the L-SIG is detected as 1 or 2, the received PPDU may be determined to be an HE PPDU.

[0166] For example, the receiving STA can determine the type of the received PPDU as non-HT, HT, or VHT PPDU based on the following: For example, if 1) the first symbol after the L-LTF signal is BPSK, and 2) an RL-SIG in which the L-SIG is repeated is not detected, the received PPDU may be determined to be a non-HT, HT, or VHT PPDU.

[0167] Furthermore, if the receiving STA detects an RL-SIG in which the L-SIG is repeated from the received PPDU, it can determine that the PPDU is an HE PPDU or EHT PPDU. In this case, if the rate (6Mbps) check fails, the received PPDU may be determined to be a non-HT, HT, or VHT PPDU. If the rate (6Mbps) check and parity check pass, if the result of applying modulo 3 to the L-SIG Length value is detected as 0, the received PPDU may be determined to be an EHT PPDU, and if the result of Length modulo 3 is not 0, the received PPDU may be determined to be an HE PPDU.

[0168] The PPDU in Figure 13 may be used to transmit and receive various types of frames, for example, the PPDU in Figure 13 may be used to (simultaneously) transmit and receive one or more of a control frame, a management frame, or a data frame.

[0169] The U-SIG included in the EHT PPDU will be described in more detail below.

[0170] For a 40 MHz EHT PPDU or ER (Extended Range) preamble, the U-SIG content is identical in the two 20 MHz subchannels. For an 80 MHz EHT PPDU or ER preamble, the U-SIG content is identical in all non-punctured 20 MHz subchannels. For a 160 / 320 MHz EHT PPDU or ER preamble, the U-SIG content is identical in all non-punctured 20 MHz subchannels within each 80 MHz subblock and may differ from the U-SIG content in other 80 MHz subblocks.

[0171] The U-SIG-1 part of the U-SIG of the EHT MU PPDU may include PHY version identifier (B0-B2), BW (B3-B5), UL / DL (B6), BSS color (B7-B12), and TXOP (B13-B19), Disregard (B20-B24), and Validate (B25).

[0172] The U-SIG-2 part of the EHT MU PPDU may include PPDU type and compression mode (B0-B1), validate (B2), punctured channel information (B3-B7), validate (B8), EHT-SIG MCS (B9-B10), number of EHT-SIG symbols (B11-B15), CRC (B16-B19), and tail (B20-B25).

[0173] As an example, assume that the UL / DL field value is set to 0. When the PPDU type and compression mode (B0-B1) field value of the U-SIG-2 part is 0, this indicates DL OFDMA transmission. When the PPDU type and compression mode (B0-B1) field value of the U-SIG-2 part is 1, this indicates EHT SU transmission or EHT sounding NDP. When the PPDU type and compression mode (B0-B1) field value of the U-SIG-2 part is 2, this indicates non-OFDMA DL MU-MIMO transmission.

[0174] As another example, assume that the UL / DL field value is set to 1. When the PPDU Type and Compression Mode (B0-B1) field value of the U-SIG-2 part is 0, this may indicate a TB PPDU (e.g., UL OFDMA or UL-non-OFDMA). And when the PPDU Type and Compression Mode (B0-B1) field value of the U-SIG-2 part is 1, this may indicate an EHT SU transmission or an EHT sounding NDP.

[0175] Here, an example of a 5-bit punctured channel indication for the non-OFDMA case in the EHT MU PPDU is shown in Table 1 below.

[0176] [Table 1-1]

[0177] [Table 1-2]

[0178] In the puncturing patterns in Table 1, 1 indicates an unpunctured subchannel and x indicates a punctured subchannel. The puncturing unit size for 80 MHz and 160 MHz PPDU bandwidths may be 20 MHz, and the puncturing unit size for 320 MHz PPDU bandwidth may be 40 MHz.

[0179] Next, the U-SIG-1 part of the U-SIG of the EHT TB PPDU may include a version identifier (B0-B2), BW (B3-B5), UL / DL (B6), BSS color (B7-B12), TXOP (B13-B19), and disregard (B20-B25), and the U-SIG-2 part may include a PPDU type and compression mode (B0-B1), validate (B2), spatial reuse 1 (B3-B6), spatial reuse 2 (B7-B10), disregard (B11-B15), CRC (B16-B19), and tail (B20-B25).

[0180] As mentioned above, the U-SIG field of the EHT MU PPDU contains 5-bit punctured channel information, but the EHT TB PPDU does not contain punctured channel information because it is assumed that the EHT TB PPDU is configured according to the resource allocation indicated by the trigger frame or TRS control information, and therefore the STA does not need to inform the AP of the resource information of the EHT TB PPDU.

[0181] Aggregated-PPDU (A-PPDU) Structure

[0182] In order to improve efficiency and throughput in a wireless LAN system, A-PPDU transmission may be defined in which PPDUs of different formats / versions are simultaneously transmitted.

[0183] The A-PPDU may correspond to a new format that combines multiple PPDU formats in the frequency domain. For example, referring to FIG. 14, in A-PPDU transmission, a first sub-PPDU (S-PPDU) format may be transmitted in a first frequency band (e.g., 160 MHz), a second S-PPDU format may be transmitted in a second frequency band (e.g., 80 MHz), and a third S-PPDU format may be transmitted in a third frequency band (e.g., 80 MHz).

[0184] However, this is merely one example, and in A-PPDU transmission, a first S-PPDU format may be transmitted in a first frequency band, and a second S-PPDU format may be transmitted in a second frequency band.

[0185] Each S-PPDU constituting an A-PPDU may be a PPDU of a different format. For example, each S-PPDU may be one of an HE PPDU, an EHT PPDU, and a PPDU of a new format after EHT (hereinafter referred to as "UHR") (i.e., a next version PPDU).

[0186] Here, the HE PPDU, EHT PPDU, and UHR PPDU may include an HE MU PPDU, an EHT MU PPDU, and a UHR MU PPDU, respectively. The UHR MU PPDU may have a structure similar to that of the EHT MU PPDU in OFDMA transmission or MU MIMO transmission. However, the dependent fields of the U-SIG field of the UHR MU PPDU may be different from the dependent fields of the U-SIG field of the EHT MU PPDU. Furthermore, the EHT MU PPDU may include a UHR SIG field instead of an EHT SIG field.

[0187] Considering the maximum bandwidth in IEEE 802.11ax (i.e., HE) and the maximum operating bandwidth of an HE STA, the minimum unit of an S-PPDU may be defined as 160 MHz to prevent decoding errors in the HE STA.

[0188] Also, if A-PPDU is not defined in IEEE 802.11be (i.e., EHT), the minimum unit of S-PPDU may be defined as 320 MHz to prevent decoding errors in EHT STAs, taking into account the maximum bandwidth in EHT and the maximum operating bandwidth of EHT STAs. Here, if A-PPDU is defined in EHT, EHT STAs can always perform decoding operations in 160 MHz units, taking into account the operating bandwidth of HE STAs.

[0189] When an HE PPDU having a maximum bandwidth of 160 MHz (i.e., configured with S-PPDUs in 160 MHz units) is included in an A-PPDU, an error may occur when an EHT STA (i.e., an EHT STA operating at 320 MHz) performs a decoding operation. In particular, when subchannel selective transmission (SST) operation / settings are not applied, a decoding error may occur across one or more EHT STAs in a BSS. Therefore, when SST operation / settings are not applied, it may not be desirable to use an HE PPDU as one S-PPDU.

[0190] Here, the SST may include an operation of dynamically changing the primary channel within the entire bandwidth. For example, the SST operation may include operating on only a portion of the entire bandwidth assuming that the entire bandwidth is the entire bandwidth.

[0191] STAs and APs that have the capability to support SST operation can set up SST operation by negotiating a trigger-enabled target wake time (TWT).

[0192] Furthermore, a 320 MHz channel may be composed of a 320-1 MHz channel and a 320-2 MHz channel, and the 320-1 MHz channel and the 320-2 MHz channel may overlap each other. This may cause decoding errors in OBSS EHT STAs (i.e., EHT STAs operating in 320 MHz channels) even if S-PPDUs are composed of 320 MHz channels.

[0193] For example, in a transmission using a 640 MHz channel formed by two 320-1 MHz channels, an EHT PPDU may be configured in the primary (P) 320 MHz channel and a UHR PPDU may be configured in the secondary (S) 320 MHz channel. In this case, an OBSS EHT STA may decode the EHT PPDU in some 160 MHz channels and decode the 320-2 MHz channel configured with the UHR PPDU in other 160 MHz channels, which may result in decoding errors.

[0194] When the above-mentioned decoding error occurs, the BSS EHT STA can decode at least the L-SIG length information (or field) and can use this to defer channel access for that time. Since the EHT STA in the BSS knows the 640 MHz channel configuration, further problems caused by the decoding error do not occur.

[0195] As a result, if A-PPDU is not defined in EHT, decoding errors may occur regardless of whether the S-PPDU unit is 160 MHz or 320 MHz from the perspective of the OBSS EHT STA. Therefore, the OBSS EHT STA can postpone channel access based on the L-SIG length information.

[0196] When SST operation / configuration is applied, decoding errors do not occur regardless of whether the S-PPDU unit is 160 MHz or 320 MHz from the perspective of the EHT STA in the BSS. However, when SST operation / configuration is not applied, decoding errors may occur when a 160 MHz S-PPDU is configured. Therefore, a 320 MHz S-PPDU structure may be used when configuring an A-PPDU.

[0197] 15 is a diagram illustrating an operation performed by a first STA according to an embodiment of the present disclosure. Here, the first STA may not be subject to SST operation / configuration, but this is not a limitation. Furthermore, "UHR" may refer to a format / type after EHT (i.e., a next-generation format / type).

[0198] The first STA may receive a specific PPDU including a plurality of sub-physical layer protocol data units (S-PPDUs) from the second STA (S1510).

[0199] The first STA may decode a first S-PPDU received on the primary 160 MHz channel among the plurality of S-PPDUs (S1520). For example, the first STA may decode a portion of the first S-PPDU corresponding to the primary 20 MHz channel.

[0200] Here, the first S-PPDU may include A-PPDU indication information (i.e., information indicating that a specific PPDU is an A-PPDU). If the first S-PPDU is an HE PPDU, the A-PPDU indication information (i.e., information indicating that a specific PPDU including an HE PPDU is an A-PPDU) may be set in at least one of bit 4 of the L-SIG field or RL-SIG field of the HE PPDU, the 8th bit (B7) of the HE-SIG-A2 field of the HE PPDU, or the 20th bit (B19) of the user field of the HE-SIG-B field of the HE PPDU.

[0201] Additionally or alternatively, based on the fact that the first S-PPDU is an EHT PPDU, the A-PPDU indication information (i.e., information indicating that a specific PPDU including an EHT PPDU is an A-PPDU) may be set to at least one of bit 4 of the L-SIG field or RL-SIG field of the EHT PPDU, the 21st bit (B20) to the 25th bit (B24) of the U-SIG-1 field of the EHT PPDU, the 14th bit (B13) to the 17th bit (B16) of the common field of the EHT-SIG field of the EHT PPDU, or the 16th bit (B15) of the user field of the EHT-SIG field of the EHT PPDU.

[0202] The specific PPDU may include a second PPDU and a first pre-padding field among the multiple S-PPDUs in the first secondary 160 MHz channel or the secondary 320 MHz channel. Here, if the first S-PPDU is an HE PPDU, the second S-PPDU may be an EHT PPDU or a UHR PPDU. If the first S-PPDU is an EHT PPDU, the second S-PPDU may be a UHR PPDU.

[0203] In this case, the first pre-padding field may include at least one of alpha pre-padding for switching time from the primary 160 MHz channel to the first secondary 160 MHz channel or the secondary 320 MHz channel and a null signal section in which no signal exists.

[0204] The length of the first pre-padding field may be the length from the L-STF included in the first S-PPDU to the HE-SIG-B field or the EHT-SIG field.

[0205] As an example, assume that the first S-PPDU is an HE PPDU including an HE-SIG-B field. If it is determined that the HE-SIG-B field of the first S-PPDU does not include a STA ID corresponding to the first STA, the first STA can decode the second S-PPDU by switching from the primary 160 MHz channel to the first secondary 160 MHz channel or the secondary 320 MHz channel.

[0206] If the first STA is an EHT STA, the first STA can switch from the primary 160 MHz channel to a first secondary 160 MHz channel. If the first STA is a UHR STA, the first STA can switch from the primary 160 MHz channel to a first secondary 160 MHz channel or a secondary 320 MHz channel.

[0207] Additionally or alternatively, based on the second S-PPDU being received on the first secondary 160 MHz channel (i.e., based on the second S-PPDU being the S-PPDU corresponding to the first secondary 160 MHz channel among the multiple S-PPDUs included in the specific PPDU), the specific PPDU may include a third PPDU corresponding to the second secondary 160 MHz channel, where the second S-PPDU may be an EHT PPDU and the third S-PPDU may be a UHR PPDU.

[0208] If it is determined that the EHT-SIG field of the EHT PPDU does not include a user field including a STA ID corresponding to the first STA, the first STA can decode the third S-PPDU by switching from the first secondary 160 MHz channel to the second secondary 160 MHz channel. In this case, the first STA may be, but is not limited to, a UHR STA.

[0209] In the second secondary 160 MHz channel, the first pre-padding field, the second pre-padding field, and the UHR PPDU may be transmitted from the base station to the terminal. The length of the second pre-padding field may be the length from the L-STF to the EHT-SIG field included in the EHT PPDU.

[0210] That is, an HE PPDU (i.e., a first S-PPDU) may be transmitted on a first primary 160 MHz channel, an EHT PPDU (i.e., a second S-PPDU) may be transmitted on a second secondary 160 MHz channel, and a UHR PPDU (i.e., a third S-PPDU) may be transmitted on a third secondary 160 MHz channel.

[0211] Here, the length of the HE PPDU may be equal to the sum of the length of the first pre-padding field and the length of the EHT PPDU, and the length of the EHT PPDU may be equal to the sum of the length of the second pre-padding field and the length of the UHR PPDU. The EHT PPDU may include information indicating that a specific PPDU is an A-PPDU.

[0212] 16 is a diagram illustrating an operation performed by a second STA according to an embodiment of the present disclosure. The second STA may be an AP STA, but is not limited thereto, and may be embodied as a non-AP STA.

[0213] The second STA may generate a specific PPDU including a plurality of sub-physical layer protocol data units (S-PPDUs) (S1610).

[0214] Each of the plurality of S-PPDUs may include a user field including a STA ID corresponding to at least one STA, including the first STA. For example, the first S-PPDU, the second S-PPDU, and the third S-PPDU included in the plurality of S-PPDUs may or may not include a user field including a STA ID corresponding to the first STA.

[0215] The second STA can transmit a specific PPDU to at least one STA including the first STA (S1620).

[0216] The configuration and related operations of the specific PPDU and the plurality of S-PPDUs correspond to the configuration and related operations of the specific PPDU and the plurality of S-PPDUs described in S1510 and S1520, and therefore, redundant description will be omitted.

[0217] In the basic wireless communication system, the operation of constructing an A-PPDU from multiple S-PPDUs configured in 160 MHz units is not defined. As described above, as an example of the present disclosure, when SST operation / configuration is not applied, an A-PPDU may include multiple S-PPDUs configured in 160 MHz units. Furthermore, the length of the pre-padding included in the A-PPDU may be configured as the length from the L-STF to the HE-SIG-B field (or EHT-SIG field). This allows a specific STA to decode a subsequent S-PPDU by switching to a subsequent channel if the corresponding S-PPDU is not assigned to the specific STA by the HE-SIG-B field (or EHT-SIG field).

[0218] The structure of the A-PPDU and a method for constructing the A-PPDU with pre-padding will be described in detail below.

[0219] Example 1

[0220] The first embodiment relates to the structure of an A-PPDU. It is assumed that the very beginning of all S-PPDUs within the A-PPDU (e.g., the start position and / or start information (e.g., L-STF) of each S-PPDU) is the same. That is, a specific STA may encounter a decoding problem for the A-PPDU depending on the unit of the S-PPDU.

[0221] In addition, the very ends of the S-PPDUs within the A-PPDU (e.g., the positions where the S-PPDUs end) may also be the same. That is, the L-length of the L-SIG field of each S-PPDU constituting the A-PPDU may all be configured with the same value.

[0222] Example 1-1

[0223] Example 1-1 relates to a method of constructing an A-PPDU by combining S-PPDUs in 160 MHz units in a 320 MHz bandwidth.

[0224] As one example, an HE PPDU may be located / assigned in the primary (P) 160 MHz, and an EHT PPDU or a UHR PPDU may be located / assigned in the secondary (S) 160 MHz. As another example, an EHT PPDU may be located / assigned in the P 160 MHz, and a UHR PPDU may be located / assigned in the S 160 MHz. As yet another example, a UHR PPDU may be located / assigned in the P 160 MHz, and an EHT PPDU may be located / assigned in the S 160 MHz.

[0225] As yet another example of the present disclosure, S-PPDUs of the same version / format may be configured. For example, an EHT PPDU or a UHR PPDU may be independently located / allocated to each of the P160 MHz and S160 MHz bands.

[0226] When an A-PPDU is constructed as described above, one or more 20 MHz channels within each 160 MHz channel may be punctured, and since the maximum bandwidth in HE is 160 MHz, an HE PPDU cannot be located / allocated in S160 MHz.

[0227] If A-PPDU is not defined in EHT and SST operation / settings are not applied, A-PPDUs configured with 160 MHz S-PPDUs may cause decoding problems from the perspective of EHT STAs (320 MHz operating EHT STAs) within the BSS. In addition, decoding problems may always occur for OBSS EHT STAs, regardless of whether SST operation / settings are enabled or disabled.

[0228] Example 1-2

[0229] Example 1-2 relates to a method of constructing an A-PPDU by combining S-PPDUs in 160 MHz units or 320 MHz units in a 640 MHz bandwidth.

[0230] Here, since the maximum bandwidth of the HE is 160 MHz, the HE PPDU cannot be located / allocated in S160 MHz / S320 MHz, and since the maximum bandwidth of the EHT is 320 MHz, the EHT PPDU cannot be located / allocated in S320 MHz.

[0231] For example, in the P160 MHz band in 640 MHz, one of an HE PPDU, an EHT PPDU, or a UHR PPDU may be located / allocated. In the S160 MHz band in 640 MHz, one of an EHT PPDU or a UHR PPDU may be located / allocated. In the remaining S320 MHz band in 640 MHz, a UHR PPDU may be located / allocated.

[0232] As described above, S-PPDUs of the same version / format may be configured. For example, an EHT PPDU or a UHR PPDU may be independently located / allocated to S160 MHz and S320 MHz, respectively.

[0233] As another example, assume that a UHR PPDU is located / allocated at S320 MHz. In this case, one UHR PPDU may be located / allocated at S320 MHz, but independent UHR PPDUs may be located / allocated at each 160 MHz.

[0234] As another example of the present disclosure, assume that one of an HE PPDU, an EHT PPDU, or a UHR PPDU is located / allocated to P160 MHz in 640 MHz. In this case, S160 MHz may be punctured, and a UHR PPDU may be located / allocated to the remaining S320 MHz. In other words, the S160 MHz channel may be punctured and not used for A-PPDU transmission.

[0235] As another example of the present disclosure, an EHT PPDU or a UHR PPDU may be located / allocated at P320 MHz in 640 MHz, and a UHR PPDU may be located / allocated at S320 MHz.

[0236] When an A-PPDU is constructed as described above, one or more 20 MHz channels may be punctured within each 160 / 320 MHz channel. For example, if S160 MHz is not punctured, one 160 MHz channel may be punctured at S320 MHz. Additionally or alternatively, one or more 20 MHz channels may be punctured in a 160 MHz channel other than the 160 MHz channel punctured at S320 MHz. In this case, the S320 MHz UHR PPDU can construct an S-PPDU by using a bandwidth of 160 MHz or less.

[0237] For example, one of an HE PPDU, an EHT PPDU, or a UHR PPDU may be located / assigned to P160MHz, one of an EHT PPDU or a UHR PPDU may be located / assigned to S160MHz, and a UHR PPDU may be located / assigned to SS160MHz. Here, when a specific 160MHz in S320MHz (e.g., the upper 160MHz or the lower 160MHz in S320MHz) is punctured, SS160MHz can refer to the remaining 160MHz (e.g., the lower 160MHz or the upper 160MHz in S320MHz).

[0238] When the A-PPDU is constructed as described above, one or more 20 MHz channels may be punctured within each 160 MHz channel.

[0239] If A-PPDU is not defined in EHT and SST operation / settings are not applied, A-PPDUs configured with S-PPDUs in 160 MHz units may cause decoding problems from the perspective of EHT STAs (320 MHz operating EHT STAs) within the BSS. In addition, regardless of whether SST operation / settings are applied, decoding problems may always occur for OBSS EHT STAs.

[0240] If A-PPDU is not defined in the EHT, A-PPDUs with S-PPDUs in 320 MHz units may cause decoding problems from the perspective of the OBSS EHT STA, regardless of whether SST operation / configuration is applied or not.

[0241] Examples 1-3

[0242] Example 1-3 relates to a method of constructing an A-PPDU by combining S-PPDUs in 160 MHz units or 320 MHz units in a 480 MHz bandwidth.

[0243] An A-PPDU in a 480 MHz bandwidth may be configured by puncturing one 160 MHz at S160 MHz or S320 MHz from an A-PPDU configuration configured in a 640 MHz bandwidth. In this case, the A-PPDU structure configured by puncturing one 160 MHz may be excluded from the A-PPDU configuration in a 640 MHz bandwidth.

[0244] As an example, one of an HE PPDU, an EHT PPDU, or a UHR PPDU may be located / allocated to P160 MHz in 480 MHz, and one of an EHT PPDU or a UHR PPDU may be located / allocated to the remaining S320 MHz.

[0245] The various types of A-PPDU structures described above can solve the decoding problem of EHT STAs and HE STAs, and eliminate the constraints on the S-PPDU unit.

[0246] Example 2

[0247] Example 2 relates to a structure of an A (aggregated)-PPDU to which pre-padding is applied, that is, Example 2 and a detailed example of Example 2 relate to an A-PPDU structure to which pre-padding is applied in order to solve a decoding problem depending on the operating bandwidth of an HE STA and an EHT STA.

[0248] The pre-padded A-PPDU structure may also be used for uplink transmission. In this case, each S-PPDU constituting the A-PPDU used for uplink transmission may include a TB PPDU instead of an MU PPDU. However, in uplink situations, since the receiver is an AP that knows the A-PPDU structure, pre-padding may not be applied to the A-PPDU.

[0249] Example 2-1

[0250] Example 2-1 relates to an A-PPDU structure in which pre-padding is applied when SST operation / settings are not applied.

[0251] Depending on the bandwidth unit of the S-PPDU, decoding errors may occur between HE / EHT STAs. For example, if the S-PPDU bandwidth unit is less than 160 MHz, an error may occur when the HE / EHT STA decodes the A-PPDU. As another example, if the S-PPDU bandwidth unit is greater than or equal to 160 MHz and less than 320 MHz, an error may occur when the EHT STA decodes the A-PPDU.

[0252] When a STA detects a PPDU using the L-STF within its operating bandwidth, it can merge specific fields of the channel detected by the L-STF during decoding. In this case, a situation may occur in which different fields in S-PPDUs of different versions / formats are merged, which can cause problems related to decoding errors.

[0253] To solve the above problem, pre-padding can be added to a specific S-PPDU. Pre-padding may be inserted into a specific S-PPDU only when the S-PPDU unit is less than 320 MHz, but is not limited to this. Pre-padding may always be inserted into a specific S-PPDU regardless of the S-PPDU unit.

[0254] As an example of the present disclosure, a Sub-HE PPDU may be transmitted using a specific channel 1 within P160 MHz.

[0255] Channel 1 may be configured in 20, 40, 80, or 160 MHz units. As an example, Channel 1 may be configured in 80 or 160 MHz units considering complexity, and may always include P20 MHz. However, if SST is enabled / configured, Channel 1 may not necessarily include P20 MHz.

[0256] The Sub HE PPDU may include A-PPDU indication information and channel switching indication information, which will be described in Example 2-3.

[0257] As another example of the present disclosure, at least one of pre-padding 1, alpha pre-padding, and a null signal and a sub EHT PPDU may be transmitted using a specific channel 2 in P320. As yet another example, a sub EHT PPDU may be transmitted using a specific channel 2 in P320.

[0258] As an example, when a sub HE PPDU is included in the A-PPDU (e.g., when a sub HE PPDU is transmitted on specific channel 1 in P160 MHz), at least one of pre-padding 1, alpha pre-padding, and a null signal, and the sub EHT PPDU may be transmitted using specific channel 2 in P320. When a sub HE PPDU is not included in the A-PPDU, the sub EHT PPDU may be transmitted using specific channel 2 in P320.

[0259] Channel 2 may be configured in units of 20, 40, 80, 160, or 320 MHz. In this case, when the total bandwidth is defined as 480 or 640 MHz, Channel 2 may be configured in units of 320 MHz. As an example, Channel 2 may be configured in units of 80, 160, or 320 MHz, taking complexity into consideration.

[0260] If a Sub HE PPDU is not included in the A-PPDU, channel 2 may be the channel that always contains P20, except that channel 1 may not contain P20 if SST is enabled / configured.

[0261] The pre-padding may be configured to have a length from the very beginning of the sub HE PPDU (i.e., L-STF) to the HE-SIG-B field. An EHT / UHR STA can determine whether a sub HE PPDU containing a P20 is assigned to the EHT / UHR STA by decoding the sub HE PPDU.

[0262] If the sub HE PPDU is not assigned to the EHT / UHR STA, the EHT / UHR STA can decode the sub EHT PPDU by switching to the channel on which the sub EHT PPDU is transmitted. In this case, the sub HE PPDU may include information instructing the STA to switch to the channel on which the sub EHT PPDU is transmitted.

[0263] If A-PPDU is not defined in EHT, EHT STAs will not be able to switch to a channel on which a sub-EHT PPDU is transmitted, i.e., it will be undesirable for a sub-HE PPDU and a sub-EHT PPDU to coexist in an A-PPDU.

[0264] Alpha pre-padding may be configured to ensure switching time. As an example, pre-padding 1 including alpha pre-padding may be configured on the A-PPDU. As another example, if pre-padding 1 is configured or if there is no need to ensure separate switching time, alpha pre-padding may not be configured separately. The length of the alpha pre-padding may be set taking into account the switching time of the EHT / UHR STA (which takes the longest time).

[0265] To facilitate detection of the L-STF in the Sub EHT PPDU, a section where no signal exists may be set at a specific time (e.g., SIFS or DIFS), which may be called a null signal / section. Therefore, the signal power of the null signal may be 0.

[0266] Pre-padding 1 / alpha pre-padding including a null signal / section may be configured on the A-PPDU, i.e., the signal power may be 0 for a certain period of time after or within the pre-padding 1 / alpha pre-padding.

[0267] As another example, if there is no need to set a null section or if a section in which no signal exists is configured in pre-padding 1 / alpha pre-padding, a separate null signal may not need to be configured.

[0268] The Sub EHT PPDU may include A-PPDU indication information and channel switching indication information. The A-PPDU indication information and channel switching indication information will be described in Example 2-3.

[0269] As yet another example of the present disclosure, assume that the sub HE PPDU and the sub EHT PPDU are all included in the A-PPDU, as shown in (a) of Figure 17. In this case, pre-padding 1, pre-padding 2, and the sub UHR PPDU may be transmitted using a specific channel 3 within 320, 480, and / or 640 MHz.

[0270] Here, at least one of pre-padding having the same length as the alpha pre-padding time and pre-padding having the same length as the null signal time may be added to pre-padding 1. At least one of alpha pre-padding and a null signal may be added to pre-padding 2.

[0271] 17(b) and 17(c), when only one of a sub HE PPDU and a sub EHT PPDU is included in an A-PPDU, pre-padding 1 / pre-padding 2 and a sub UHR PPDU may be transmitted using the specific channel 3. Here, at least one of an alpha pre-padding signal and a null signal may be added to pre-padding 1 / pre-padding 2.

[0272] The specific channel 3 may be configured in units of 20, 40, 80, 160, or 320 MHz, but may be configured in units of 80, 160, or 320 MHz in consideration of complexity. Only when the 480 / 640 MHz bandwidth is introduced, the specific channel 3 may be configured in units of 320 MHz.

[0273] As an example of the present disclosure, it is assumed that the A-PPDU is configured as shown in (a) of Fig. 17. The length of pre-padding 1 may be the length from the very beginning of the sub HE PPDU (i.e., the L-STF) to the HE-SIG-B field.

[0274] Each EHT / UHR STA can decode the sub HE PPDU containing P20 and determine whether the sub HE PPDU is assigned to it. If the sub HE PPDU is not assigned to it, the EHT / UHR STA can decode the sub EHT PPDU by switching to the channel on which the sub EHT PPDU is transmitted. In this case, the sub HE PPDU may include information instructing the STA to switch to the channel on which the sub EHT PPDU is transmitted.

[0275] If A-PPDU is not defined in EHT, EHT STAs will not be able to switch to a channel on which a sub-EHT PPDU is transmitted, i.e., it will be undesirable for a sub-HE PPDU and a sub-EHT PPDU to coexist in an A-PPDU.

[0276] If alpha pre-padding is required (or configured) for the channel on which the Sub EHT PPDU is transmitted, additional pre-padding may be present in the channel on which the Sub EHT PPDU is transmitted, with a length corresponding to the alpha pre-padding. Also, if a null signal / section is required (or configured) for the channel on which the Sub EHT PPDU is transmitted, additional pre-padding may be present in the channel on which the Sub EHT PPDU is transmitted, with a length corresponding to the null signal / section.

[0277] The length of pre-padding 2 may be the length from the L-STF to the EHT SIG field of the sub-EHT PPDU. A UHR STA to which a sub-EHT PPDU is not assigned can determine whether the sub-EHT PPDU is assigned to the UHR STA by decoding the sub-EHT PPDU through channel switching. If the sub-EHT PPDU is not assigned to the UHR STA, the UHR STA can decode the UHR PPDU by switching to the channel on which the UHR PPDU is transmitted. In this case, the sub-EHT PPDU may include information instructing switching to the channel on which the sub-UHR PPDU is transmitted.

[0278] Alpha pre-padding may be configured to ensure channel switching time, and pre-padding 2 may be configured to include alpha pre-padding. In this case, if pre-padding 2 includes time to ensure channel switching time, or if separate time for channel switching is not required, alpha pre-padding may not be present.

[0279] Here, the length of the alpha pre-padding may be set based on the channel switching time of the UHR STA that requires the longest channel switching time.

[0280] To facilitate detection of the L-STF in the Sub UHR PPDU, a section where no signal is present may be set at a specific time (e.g., SIFS or DIFS), which may be called a null signal / section. Therefore, the signal power of the null signal may be 0.

[0281] Pre-padding 2 / alpha pre-padding including a null signal / section may be configured on the A-PPDU, i.e., the signal power may be 0 for a certain period of time after or within the Pre-padding 2 / alpha pre-padding.

[0282] As another example, if there is no need to set a null section or if a section where no signal exists is set in pre-padding 2 / alpha pre-padding, a separate null signal may not need to be configured.

[0283] As an example of the present disclosure, it is assumed that the A-PPDU is configured as shown in FIG. 17(b) or (c).

[0284] 17(b), when a sub HE PPDU and a UHR PPDU are transmitted together, pre-padding 1 may be used. The length of pre-padding 1 may be the length from the very beginning of the sub HE PPDU (i.e., the L-STF) to the HE-SIG-B field.

[0285] A UHR STA can determine whether the sub HE PPDU containing P20 is assigned to the UHR STA by decoding the sub HE PPDU. If the sub HE PPDU is not assigned to the UHR STA, the UHR STA can decode the UHR PPDU by switching to the channel on which the UHR PPDU is transmitted. In this case, the sub HE PPDU may include information instructing the STA to switch to the channel on which the UHR PPDU is transmitted.

[0286] 17(c), when both the sub EHT PPDU and the UHR PPDU are transmitted, pre-padding 2 may be used. The length of pre-padding 2 may be the length from the very beginning of the sub EHT PPDU (i.e., the L-STF) to the EHT-SIG field.

[0287] A UHR STA can determine whether the sub EHT PPDU containing P20 is assigned to the UHR STA by decoding the sub EHT PPDU. If the sub EHT PPDU is not assigned to the UHR STA, the UHR STA can decode the UHR PPDU by switching to the channel on which the UHR PPDU is transmitted. In this case, the sub UHR PPDU may include information instructing switching to the channel on which the UHR PPDU is transmitted.

[0288] Alpha pre-padding may be configured to ensure channel switching time, or pre-padding 1 / 2 may be configured to include alpha pre-padding. In this case, if pre-padding 1 / 2 includes time to ensure channel switching time, or if separate time for channel switching is not required, alpha pre-padding may not be present.

[0289] Here, the length of the alpha pre-padding may be set based on the channel switching time of the UHR STA that requires the longest channel switching time.

[0290] To facilitate detection of the L-STF in the Sub UHR PPDU, a section where no signal is present may be set at a specific time (e.g., SIFS or DIFS), which may be called a null signal / section. Therefore, the signal power of the null signal may be 0.

[0291] Pre-padding 1 / 2 / alpha pre-padding including a null signal / section may be configured on the A-PPDU, i.e., the signal power may be 0 for a certain period of time after or within the pre-padding 1 / 2 / alpha pre-padding.

[0292] As another example, if there is no need to set a null section or if a section where no signal exists is set in pre-padding 1 / 2 / alpha pre-padding, a separate null signal may not need to be configured.

[0293] All pre-padding (i.e., pre-padding 1 / 2, alpha pre-padding, alpha pre-padding / pre-padding of the same length as the null signal time) (except the null signal portion) may be signals that have low correlation with L-STF and L-LTF, in order to reduce the PPDU detection probability.

[0294] Additionally or alternatively, pre-padding may be configured based on a specific field. That is, at least one of the L-SIG field, RL-SIG field, U-SIG field, EHT-SIG field, EHT-STF field, EHT-LTF field, data field, HE-SIG-A field, HE-SIG-B field, HE-STF, HE-LTF, UHR SIG field, UHR STF, and UHR LTF may be repeated, and at least one repeated symbol may be configured as pre-padding. Additionally or alternatively, at least one symbol of a specific field may be repeated, and at least one repeated symbol may be configured as pre-padding.

[0295] Example 2-2

[0296] Example 2-2 relates to an A-PPDU structure when SST operation / settings are applied.

[0297] For the sake of uniformity of the A-PPDU structure, even if the SST operation / setting is applied, the A-PPDU may be configured as described in Example 2-1, thereby resolving the decoding problem of the OBSS STA.

[0298] As another example, when SST operation / settings are applied, decoding can be performed only for a specific channel, so pre-padding and null signals do not need to be included in the A-PPDU.

[0299] As another example, when the SST operation / setting is applied, the alpha pre-padding and null signal may be excluded from the A-PPDU structure described in Example 2-1. That is, the A-PPDU may include pre-padding 1 / 2, but may not include the alpha pre-padding and null signal.

[0300] In this case, channel switching is not required because the SST operation / setting is applied, and therefore the length of pre-padding 1 / 2 may be shorter than the length of pre-padding 1 in Example 2-1. As an example, when the SST operation / setting is applied, the length of pre-padding 1 / 2 included in the A-PPDU may be the combined length of L-STF and L-LTF or the combined length of L-STF, L-LTF, L-SIG field, and RL-SIG field.

[0301] Example 2-3

[0302] Example 2-3 relates to A-PPDU indication information and channel switch indication information.

[0303] A-PPDU indication information and channel switching indication information may be transmitted and received via the sub HE PPDU and / or sub EHT PPDU, and the STA may perform A-PPDU indication and channel switching indication using the A-PPDU indication information and channel switching indication information.

[0304] For example, the A-PPDU indication information and the channel switching indication information may be set by a reserved bit / field of the sub-HE PPDU. For another example, the A-PPDU indication information and the channel switching indication information may be set by a reserved bit / field and a disregard bit of the sub-EHT PPDU.

[0305] The A-PPDU indication information and the channel switching indication information may be indicated by setting other values ​​than the default values ​​to the reserved bits / fields and / or ignore fields described above.

[0306] Example 2-3-1

[0307] Example 2-3-1 relates to a method for setting A-PPDU indication information and channel switching indication information using a specific field / bit of a Sub HE PPDU.

[0308] In the examples described below, the A-PPDU indication information and the channel switching indication information may be indicated by default values ​​of specific fields / bits of the sub HE PPDU and / or values ​​other than the default values. If the A-PPDU is not defined in the EHT, channel switching of the EHT STA may be disabled.

[0309] For example, the A-PPDU indication information and the channel switching indication information may be set in the reserved bit (bit 4) of the L-SIG field / RL-SIG field of the Sub HE PPDU. The default value of the reserved bit (bit 4) of the L-SIG field / RL-SIG field may be 0.

[0310] As another example, A-PPDU indication information and channel switching indication information may be set in the 15th bit (B14) of HE-SIG-A1 of the Sub HE SU PPDU (where the default value of B14 is 1) and / or the 15th bit (B14) of HE-SIG-A2 (where the default value of B14 is 1).

[0311] As yet another example, the A-PPDU indication information and the channel switching indication information may be set in the eighth bit (B7) (where the default value of B7 is 1) of the HE-SIG-A2 of the Sub HE MU PPDU.

[0312] As yet another example, during MU MIMO transmission, A-PPDU indication information and channel switching indication information may be set in the 20th bit (B19) (where the default value of B19 is 0) in the user field of the HE-SIG-B field of the sub HE PPDU.

[0313] The information to switch to a specific channel may be indicated by a specific field / bit or a combination thereof in the sub HE PPDU described above.

[0314] For example, if a sub EHT PPDU exists in the A-PPDU, the above-mentioned specific field / bit or a combination thereof of the sub HE PPDU may indicate information to switch to a channel on which the sub EHT PPDU is transmitted.If a sub EHT PPDU does not exist in the A-PPDU, the above-mentioned specific field / bit or a combination thereof of the sub HE PPDU may indicate information to switch to a channel on which the sub UHR PPDU is transmitted.

[0315] The A-PPDU indication information and the channel switching indication information may both exist. That is, the A-PPDU indication information and the channel switching indication information may both be indicated by a specific field / bit or a combination thereof. However, this is merely an example, and the A-PPDU indication information and the channel switching indication information may each be indicated independently.

[0316] When channel switching indication information is indicated separately, information indicating switching to a specific channel may not be set as the default value of a specific field / bit (i.e., a field / bit associated with the channel switching indication information).

[0317] For example, if bit 4 of the L-SIG / RL-SIG field of the sub HE PPDU is set to 1, this may indicate an A-PPDU (i.e., indicate that the sub HE PPDU is included in an A-PPDU), and the eighth bit (B7) of the HE-SIG-A2 field of the sub HE PPDU may indicate channel switching information.

[0318] As an example, assume that the total bandwidth is 640 MHz. If the value of B7 in the HE-SIG-A2 field is set to 0, this can indicate switching to S160 MHz. If the value of B7 in the HE-SIG-A2 field is set to 1, this can indicate switching to S320 MHz.

[0319] As another example, assume that the total bandwidth is 320 MHz. If the value of B7 in the HE-SIG-A2 field is set to 0, this can indicate switching to S80 MHz. If the value of B7 in the HE-SIG-A2 field is set to 1, this can indicate switching to S160 MHz.

[0320] As yet another example, assume that the total bandwidth is 320 MHz. If bit 4 of the L-SIG / RL-SIG field of the sub HE PPDU is set to 1 and bit B7 of the HE-SIG-A2 field is set to 0, this indicates a switch to S80 MHz. If bit 4 of the L-SIG / RL-SIG field of the sub HE PPDU is set to 1 and bit B7 of the HE-SIG-A2 field is set to 1, this indicates a switch to a lower 80 MHz within S160 MHz. If bit 4 of the L-SIG / RL-SIG field of the sub HE PPDU is set to 0 and bit B7 of the HE-SIG-A2 field is set to 0, this indicates a switch to a higher 80 MHz within S160 MHz.

[0321] Additionally or alternatively, the A-PPDU indication information and channel switching indication information may be indicated by a combination of specific fields / bits in the L-SIG field, RL-SIG field, HE-SIG-A field, and HE-SIG-B field of the above-mentioned sub HE PPDU.

[0322] If an EHT / UHR STA does not have a user field configured with its own STA ID in the HE-SIG-B field of the sub HE PPDU, it can switch to a specific channel using the information in the above-mentioned specific fields / bits of the sub HE PPDU.

[0323] Example 2-3-2

[0324] Example 2-3-2 relates to a method for setting A-PPDU indication information and channel switching indication information using a specific field / bit of a Sub EHT PPDU.

[0325] In the examples described below, the A-PPDU indication information and the channel switching indication information may be indicated by default values ​​and / or values ​​other than the default values ​​of specific fields / bits of the sub EHT PPDU.

[0326] For example, the A-PPDU indication information and the channel switching indication information may be set in the reserved bit (bit 4) of the L-SIG field / RL-SIG field of the Sub EHT PPDU. The default value of the reserved bit (bit 4) of the L-SIG field / RL-SIG field may be 0.

[0327] As another example, the A-PPDU indication information and the channel switching indication information may be set in at least one of the 21st bit (B20) to the 25th bit (B24) of the U-SIG1 field of the Sub EHT PPDU. The default value of B21 to B24 of the U-SIG1 field may all be 1.

[0328] As another example, the A-PPDU indication information and the channel switching indication information may be set in at least one of the 14th bit (B13) to the 17th bit (B16) in the common field of the EHT-SIG field of the Sub EHT PPDU. In this case, the default values ​​of B13 to B16 in the common field may all be 1.

[0329] During non-MU MIMO transmission, A-PPDU indication information and channel switching indication information may be set in the 16th bit (B15) (where the default value of B15 is 1) in the user field of the EHT-SIG field of the sub EHT PPDU.

[0330] The above-mentioned specific fields / bits of the sub EHT PPDU or a combination thereof may indicate information to switch to a channel on which the UHR EHT PPDU is transmitted.

[0331] The A-PPDU indication information and the channel switching indication information may both exist. That is, the A-PPDU indication information and the channel switching indication information may both be indicated by a specific field / bit or a combination thereof. However, this is merely an example, and the A-PPDU indication information and the channel switching indication information may each be indicated independently.

[0332] As an example, if the 21st bit (B20) of the U-SIG1 field of a sub EHT PPDU is set to 0, this can indicate an A-PPDU (i.e., indicate that a sub EHT PPDU is included in the A-PPDU).

[0333] A bitmap for instructing channel switching within a 320 MHz bandwidth may be set in the 22nd bit (B21) to the 25th bit (B24) of the U-SIG1 field. In this case, the bitmap for instructing channel switching within a 320 MHz bandwidth can instruct channel switching in 80 MHz channel units.

[0334] As another example, a bitmap for instructing channel switching within a 640 MHz bandwidth may be set in the 22nd bit (B21) to the 25th bit (B24) of the U-SIG1 field. In this case, the bitmap for instructing channel switching within a 640 MHz bandwidth may instruct channel switching in 160 MHz channel units.

[0335] As another example, a bitmap indicating channel switching within a 640 MHz bandwidth may be set for bits B21 to B24 of the U-SIG1 field and bits B13 to B16 of the common field in the EHT-SIG field. In this case, the bitmap indicating channel switching within a 640 MHz bandwidth may indicate channel switching in 80 MHz channel units.

[0336] As yet another example of the present disclosure, the channel switching indication information may be indicated by a specific value instead of a bitmap. For example, if the value of the 21st bit (B20) of the U-SIG1 field is set to 0, this may indicate an A-PPDU (i.e., indicate that a sub EHT PPDU is included in the A-PPDU). Then, information indicating switching to a specific channel may be set to specific values ​​of B21 to B24 of the U-SIG1 field.

[0337] As an example, specific channels mapped to specific values ​​of B21 to B24 of the U-SIG field may be implemented as shown in Table 2. A channel to be switched to a physical location other than the primary channel or secondary channel may be indicated.

[0338] [Table 2]

[0339] As yet another example of the present disclosure, specific fields / bits of the sub-EHT PPDU described above may not be used to indicate an A-PPDU. The channel to be switched may be indicated by only a specific number of bits among the specific fields / bits of the sub-EHT PPDU described above. In this case, all bits indicating the channel to be switched do not have to be set to default values ​​at the same time. As an example, channel switching may be indicated using bits B20 to B23 of the U-SIG1 field. In this case, when indicating channel switching, all bits B20 to B23 of the U-SIG1 field do not have to be set to 1.

[0340] The A-PPDU indication information / channel switching information may be indicated by various combinations of the specific fields / bits of the sub EHT PPDU described above. That is, the combinations of the specific fields / bits of the sub EHT PPDU for indicating the A-PPDU indication information / channel switching information and the mapping of the specific fields / bit values ​​may vary.

[0341] If a UHR STA does not have a user field configured with its own STA ID in the EHT-SIG field of the sub EHT PPDU, it can switch to a specific channel (e.g., the channel on which the UHR PPDU is transmitted) using the information in the above-mentioned specific fields / bits of the sub EHT PPDU.

[0342] 18 is a diagram illustrating a PPDU transmission / reception procedure between a transmitting STA and a receiving STA according to an embodiment of the present disclosure. Some steps illustrated in FIG. 17 may be omitted depending on the situation and / or settings. The transmitting device and the receiving STA may be an AP and / or a non-AP STA.

[0343] The transmitting STA may acquire control information related to the above-mentioned tone plan (or RU) (S105). The control information related to the tone plan may include the size and location of the RU, control information related to the RU, information about the frequency band in which the RU is included, information about the STA receiving the RU, etc.

[0344] The transmitting STA may configure / generate a PPDU based on the acquired control information (S110). Configuring / generating a PPDU may mean configuring / generating each field of the PPDU. That is, the step of configuring / generating a PPDU may include a step of configuring EHT-SIG-A / B / C fields that contain control information related to the tone plan.

[0345] That is, the step of configuring / generating the PPDU may include a step of configuring a field containing control information (e.g., N bitmap) indicating the size / location of the RU, and / or a step of configuring a field containing an identifier (e.g., AID) of the STA receiving the RU.

[0346] Furthermore, the step of configuring / generating the PPDU may include the step of generating an STF / LTF sequence to be transmitted in a specific RU. The STF / LTF sequence may be generated based on a preset STF generation sequence / LTF generation sequence.

[0347] Additionally, configuring / generating a PPDU may include generating a data field (ie, an MPDU) to be transmitted on a specific RU.

[0348] The transmitting STA may transmit the configured / generated PPDU to the receiving STA (S115).

[0349] Specifically, the transmitting STA can perform at least one of CSD (cyclic shift diversity), spatial mapping, IDFT (inverse discrete Fourier transform) / IFFT (inverse fast Fourier transform) operations, GI (guard interval) insertion operations, etc.

[0350] The receiving STA can decode the PPDU to obtain control information related to the tone-plan (or RU) (S120).

[0351] Specifically, the receiving STA can decode the L-SIG, U-SIG, and EHT-SIG of the PPDU based on the L-STF / LTF to obtain information included in the L-SIG, U-SIG, and EHT-SIG fields. Information about various tone plans (i.e., RUs) of the present disclosure may be included in the EHT-SIG, and the receiving STA can obtain information about the tone plans (i.e., RUs) through the EHT-SIG.

[0352] The receiving STA can decode the remaining part of the PPDU based on the acquired information about the tone plan (i.e., RU) (S125). For example, the receiving STA can decode the STF / LTF field of the PPDU based on the information about the tone plan (i.e., RU). The receiving STA can also decode the data field of the PPDU based on the information about the tone plan (i.e., RU) to acquire the MPDU included in the data field.

[0353] The receiving STA may also perform a processing operation of transmitting the decoded data to a higher layer (e.g., MAC layer), and may perform a subsequent operation when the higher layer instructs the PHY layer to generate a signal corresponding to the data transmitted to the higher layer.

[0354] The embodiments described above are combinations of the components and features of the present disclosure in a predetermined form. Each component or feature should be considered optional unless otherwise explicitly stated. Each component or feature may be implemented without being combined with other components or features. It is also possible to combine some components and / or features to form embodiments of the present disclosure. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in another embodiment, or may be replaced with corresponding components or features of another embodiment. It is clear that claims that do not have an explicit reference relationship in the claims may be combined to form embodiments, or may be included as new claims by amendment after filing.

[0355] It is obvious to those skilled in the art that the present disclosure can be embodied in other specific forms without departing from the essential features of the present disclosure. Therefore, the above detailed description should not be interpreted as limiting in any respect, but should be considered as illustrative. The scope of the present disclosure should be determined by reasonable interpretation of the appended claims, and any modifications within the equivalent scope of the present disclosure are included in the scope of the present disclosure.

[0356] The scope of the present disclosure includes software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that cause a device or computer to perform operations according to the methods of various embodiments, as well as non-transitory computer-readable media on which such software or instructions are stored and executable on a device or computer. Instructions usable for programming a processing system to perform features described in this disclosure may be stored on or in a storage medium or computer-readable storage medium, and computer program products including such storage media may be used to embody features described in this disclosure. The storage medium may include, but is not limited to, high-speed random access memory such as DRAM, SRAM, DDR RAM, or other random access solid-state memory devices, and may include non-volatile memory such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. Memory optionally includes one or more storage devices located remotely from the processor. The memory, or alternatively, a non-volatile memory device within the memory, comprises a non-transitory computer-readable storage medium. The features described in this disclosure may be embodied in software and / or firmware stored on any one of a number of machine-readable media and capable of controlling the hardware of a processing system and allowing the processing system to interact with other mechanisms that utilize the results of embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers. [Industrial Applicability]

[0357] The method proposed in this disclosure has been described mainly as being applied to an IEEE 802.11-based system, but it can also be applied to various wireless LANs or wireless communication systems other than the IEEE 802.11-based system.

Claims

1. A method performed by a first station (STA) in a wireless LAN system, the method comprising: receiving a specific PPDU including a plurality of S(sub)-PPDUs (physical layer protocol data units) from a second STA; decoding a first S-PPDU received on a primary 160 MHz channel among the plurality of S-PPDUs, the first S-PPDU including information indicating that the specific PPDU is an A (aggregated)-PPDU; the specific PPDU includes a second S-PPDU and a first pre-padding field among the plurality of S-PPDUs in a first secondary 160 MHz channel or a secondary 320 MHz channel; A method in which the length of the first pre-padding field is the length from the L (legacy)-STF (short training field) included in the first S-PPDU to the HE (high throughput)-SIG-B field or the EHT (extremely high throughput)-SIG field.

2. Based on the fact that the first S-PPDU is an HE PPDU including the HE-SIG-B field, 2. The method of claim 1, wherein the second S-PPDU is decoded by switching from the primary 160 MHz channel to the first secondary 160 MHz channel or the secondary 320 MHz channel by the first STA based on the fact that a user field including a STA ID corresponding to the first STA is not included in the HE-SIG-B field.

3. Based on the first S-PPDU being an HE PPDU, the second S-PPDU is an EHT PPDU or an ultra-high reliability (UHR) PPDU; 2. The method of claim 1, wherein the second S-PPDU is a UHR PPDU based on the first S-PPDU being an EHT PPDU.

4. 2. The method of claim 1, wherein the first pre-padding field includes alpha pre-padding for switching time from the primary 160 MHz channel to the first secondary 160 MHz channel or the secondary 320 MHz channel and a null signal section in which no signal is present.

5. based on the second S-PPDU being received on the first secondary 160 MHz channel, the specific PPDU includes a third PPDU corresponding to a second secondary 160 MHz channel; the second S-PPDU is an EHT PPDU; The method of claim 1 , wherein the third S-PPDU is a UHR PPDU.

6. 6. The method of claim 5, wherein the third S-PPDU is decoded by switching from the first secondary 160 MHz channel to the second secondary 160 MHz channel by the first STA based on the fact that a user field including a STA ID corresponding to the first STA is not included in an EHT-SIG field of the EHT PPDU.

7. 6. The method of claim 5, wherein the first pre-padding field, the second pre-padding field, and the UHR PPDU are received from a base station in the second secondary 160 MHz channel.

8. The method of claim 7, wherein the length of the second pre-padding field is a length from an L-STF to an EHT-SIG field included in the EHT PPDU.

9. The method of claim 7, wherein the EHT PPDU includes information indicating that the specific PPDU is an A-PPDU.

10. The information indicating that the specific PPDU is an A-PPDU includes: bit 4 of the L-SIG field or the RL-SIG field of the HE PPDU; The eighth bit (B7) of the HE-SIG-A2 field of the HE PPDU, or 3. The method of claim 2, wherein the 20th bit (B19) of the user field of the HE-SIG-B field of the HE PPDU is set to at least one of the bits.

11. The information indicating that the specific PPDU is an A-PPDU includes: Bit 4 of the L-SIG field or RL-SIG field of the EHT PPDU; The 21st bit (B20) to the 25th bit (B24) of the U (universal)-SIG-1 field of the EHT PPDU, The 14th bit (B13) to the 17th bit (B16) of the common field of the EHT-SIG field of the EHT PPDU, or 10. The method of claim 9, wherein the user information is set to at least one of the sixteenth bits (16) of the user field of the EHT-SIG field of the EHT PPDU.

12. The method of claim 1 , wherein a subchannel selective transmission (SST) setting is not applied to the first STA.

13. The method of claim 12, wherein the length of the HE PPDU is equal to the sum of the length of the first pre-padding field and the length of the EHT PPDU; The method of claim 7 , wherein the length of the EHT PPDU is equal to the sum of the length of the second pre-padding field and the length of the UHR PPDU.

14. A first STA (station) in a wireless LAN system, the first STA comprising: at least one transceiver; at least one processor coupled to the at least one transceiver; The at least one processor receiving a specific PPDU including a plurality of S(sub)-PPDUs (physical layer protocol data units) from a second STA via the at least one transceiver; a first S-PPDU received on a primary 160 MHz channel among the plurality of S-PPDUs is decoded, and the first S-PPDU is configured to include information indicating that the specific PPDU is an A (aggregated)-PPDU; the specific PPDU includes a second S-PPDU and a first pre-padding field among the plurality of S-PPDUs in a first secondary 160 MHz channel or a secondary 320 MHz channel; The length of the first pre-padding field is the length from the L (legacy)-STF (short training field) included in the first S-PPDU to the HE (high throughput)-SIG-B field or the EHT (extremely high throughput)-SIG field, first STA.

15. A second STA (station) in a wireless LAN system, the second STA comprising: at least one transceiver; at least one processor coupled to the at least one transceiver; The at least one processor generating a specific PPDU including a plurality of S (Sub)-PPDUs (physical layer protocol data units); configured to transmit the specific PPDU to at least one STA, including a first STA, via the at least one transceiver; The specific PPDU is a first S-PPDU of the plurality of S-PPDUs in a primary 160 MHz channel; a second S-PPDU among the plurality of S-PPDUs in the first secondary 160 MHz channel or the secondary 320 MHz channel; and a first pre-padding field; The first S-PPDU includes information indicating that the specific PPDU is an A (aggregated)-PPDU; The length of the first pre-padding field is the length from the L (legacy)-STF (short training field) included in the first S-PPDU to the HE (high throughput)-SIG-B field or the EHT (extremely high throughput)-SIG field, second STA.

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