Method and apparatus for performing sensing procedure in wireless LAN system

Abstract

To provide a method and an apparatus for performing a sensing procedure in a wireless LAN system.SOLUTION: A method includes the steps of: receiving at least one sensing measurement setup request frame requesting at least one sensing measurement setup from a second STA; transmitting at least one sensing measurement setup response frame to the second STA in response to the at least one sensing measurement setup request frame; and transmitting a sensing measurement setup end frame to the second STA or receiving the sensing measurement setup end frame from the second STA. The sensing measurement setup end frame may include specific information indicating whether a first STA or the second STA requests to end all of the at least one sensing measurement setup, and a measurement setup ID field based on the first information.SELECTED DRAWING: Figure 18

Description

[Technical Field]

[0001] The present disclosure relates to a method and apparatus for communicating in a wireless local area network (WLAN) system, and more particularly to a method and apparatus for performing a sensing procedure in a next generation WLAN system. [Background technology]

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

[0003] Improved technologies for providing sensing for devices using WLAN signals (i.e., WLAN sensing) are being discussed. For example, the IEEE 802.11 Task Group (TG) bf is developing standard technologies for sensing objects (e.g., people, objects, etc.) based on channel estimation using WLAN signals between devices operating in frequency bands below 7 GHz. Object sensing based on WLAN signals has the advantages of being able to utilize existing frequency bands and having a lower possibility of privacy intrusion compared to existing sensing technologies. The expanded frequency range available in WLAN technology makes it possible to obtain precise sensing information. At the same time, technologies for reducing power consumption to efficiently support precise sensing procedures are also being researched. Summary of the Invention [Problem to be solved by the invention]

[0004] The technical problem of the present disclosure is to provide a method and apparatus for performing a sensing procedure in a wireless LAN system.

[0005] A further technical object of the present disclosure is to provide a method and apparatus for transmitting and receiving a frame that completes one or more sensing measurement setups in a wireless LAN system.

[0006] 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]

[0007] According to one embodiment of the present disclosure, a method for performing a sensing procedure by a first station (STA) in a wireless LAN system includes the steps of receiving at least one sensing measurement setup request frame from a second STA requesting at least one sensing measurement setup; transmitting at least one sensing measurement setup response frame to the second STA in response to the at least one sensing measurement setup request frame; and transmitting a sensing measurement setup termination frame to the second STA or receiving the sensing measurement setup termination frame from the second STA, wherein the sensing measurement setup termination frame may include i) specific information indicating whether the first STA or the second STA requests to terminate all of the at least one sensing measurement setup, and ii) a measurement setup identifier field based on the first information.

[0008] As another embodiment of the present disclosure, a method for performing a sensing procedure by a second station (STA) includes the steps of transmitting at least one sensing measurement setup request frame to a first STA requesting at least one sensing measurement setup, receiving at least one sensing measurement setup response frame from the first STA in response to the at least one sensing measurement setup request frame, and transmitting a sensing measurement setup end frame to the first STA or receiving the sensing measurement setup end frame from the first STA, wherein the sensing measurement setup end frame may include i) specific information indicating whether the first STA or the second STA requests to end all of the at least one sensing measurement setup, and ii) a measurement setup ID (identifier) ​​field based on the first information. [Effects of the Invention]

[0009] According to the present disclosure, a method and apparatus for performing a sensing procedure in a wireless LAN system can be provided.

[0010] According to the present disclosure, a method and apparatus for transmitting and receiving a frame for terminating one or more sensing measurement setups in a wireless LAN system can be provided.

[0011] According to the present disclosure, in a wireless LAN system, a STA can terminate a set-up role / parameter when it no longer uses it, thereby enabling more efficient memory management.

[0012] 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]

[0013] 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.

[0014] [Figure 1] FIG. 1 is a block diagram illustrating a wireless communication device according to an embodiment of the present disclosure.

[0015] [Figure 2] FIG. 1 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0016] [Figure 3] FIG. 1 is a diagram illustrating a link setup process to which the present disclosure can be applied.

[0017] [Figure 4] FIG. 10 is a diagram illustrating a backoff process to which the present disclosure can be applied.

[0018] [Figure 5] 10A and 10B are diagrams for explaining a CSMA / CA base frame transmission operation to which the present disclosure can be applied.

[0019] [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.

[0020] [Figure 7] FIG. 1 illustrates an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure is applicable.

[0021] [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.

[0022] [Figure 11] FIG. 1 illustrates an exemplary structure of an HE-SIG-B field.

[0023] [Figure 12] FIG. 1 is a diagram illustrating a MU-MIMO scheme in which multiple users / STAs are assigned to one RU.

[0024] [Figure 13] FIG. 10 is a diagram illustrating an example of a PPDU format to which the present disclosure can be applied.

[0025] [Figure 14] FIG. 10 illustrates an exemplary format of a trigger frame to which the present disclosure can be applied.

[0026] [Figure 15] FIG. 10 is a diagram for explaining an HE Non-TB / TB sounding procedure to which the present disclosure can be applied.

[0027] [Figure 16] FIG. 10 is a diagram for explaining a wireless LAN sensing procedure to which the present disclosure can be applied.

[0028] [Figure 17] A diagram illustrating the process by which a STA transmits and receives a sensing measurement setup request / response frame according to one embodiment of the present disclosure.

[0029] [Figure 18] A diagram for explaining the process by which a first STA performs a sensing procedure according to one embodiment of the present disclosure.

[0030] [Figure 19] 10 is a diagram illustrating a process in which a second STA performs a sensing procedure according to one embodiment of the present disclosure. FIG.

[0031] [Figure 20] FIG. 10 is a diagram illustrating an example of a sensing measurement setup end frame format according to one embodiment of the present disclosure. [Figure 21] FIG. 10 is a diagram illustrating an example of a sensing measurement setup end frame format according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] Below, technical features to which the examples of the present disclosure can be applied will be described.

[0039] FIG. 1 is a block diagram illustrating a wireless communication device according to an embodiment of the present disclosure.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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).

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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 following example, 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 and received signals may be stored in memories 104, 204 of FIG. 1.

[0051] 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.

[0052] FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0053] 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.

[0054] 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.

[0055] 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).

[0056] 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.

[0057] 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.

[0058] 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).

[0059] 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.

[0060] 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.

[0061] In the above-described DS structure, an Extended Service Set (ESS) may be configured to provide wider coverage.

[0062] 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.

[0063] 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.

[0064] FIG. 3 is a diagram illustrating a link setup process to which the present disclosure can be applied.

[0065] 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.

[0066] 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.

[0067] 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).

[0068] Although not shown in FIG. 3, the scanning operation may be performed in a passive scanning manner. In passive scanning, a scanning STA waits for a beacon frame while changing channels. A beacon frame is a management frame defined in IEEE 802.11 and is periodically transmitted to announce the existence of a wireless network and allow a scanning STA to search for and join the wireless network. In a BSS, an AP is responsible for periodically transmitting beacon frames, while in an IBSS, STAs within the IBSS transmit beacon frames in turn. When a scanning STA receives a beacon frame, it saves information about the BSS included 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 included 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] After the STA is successfully authenticated, an association process may be performed in step S330. The association process includes the STA sending an association request frame to the AP, and the AP responding by sending an association response frame to the STA.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] FIG. 4 is a diagram illustrating a backoff process to which the present disclosure can be applied.

[0078] 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.

[0079] 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).

[0080] 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,...).

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] FIG. 5 is a diagram for explaining a CSMA / CA base frame transmission operation to which the present disclosure can be applied.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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 STA3's NAV timer expires, it can use carrier sensing to determine whether the channel is in use. If STA3 determines that the channel is not in use by another terminal within DIFS after the expiration of the NAV timer, it can attempt channel access after the contention window (CW) with random backoff has elapsed.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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).

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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).

[0106] 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.

[0107] 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.

[0108] 8 to 10 are diagrams illustrating examples of resource units in a wireless LAN system to which the present disclosure can be applied.

[0109] 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.

[0110] 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.

[0111] FIG. 8 is a diagram illustrating an exemplary arrangement of resource units (RUs) used on a 20 MHz band.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] FIG. 9 is a diagram illustrating an exemplary arrangement of resource units (RUs) used on a 40 MHz band.

[0116] 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.

[0117] Also, as shown in the figure, when used for a single user, 484-RU may be used.

[0118] FIG. 10 is a diagram illustrating an exemplary arrangement of resource units (RUs) used on an 80 MHz band.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] Information about the location of the RU may be signaled in the HE-SIG-B in HE PPDU format.

[0127] FIG. 11 shows an example structure of the HE-SIG-B field.

[0128] 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 subfields. When HE-SIG-B compression is not applied, the common fields may be included in the HE-SIG-B.

[0129] 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.).

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] The set of user-specific subfields contains information on how all users (STAs) of the PPDU decode their payloads. The user-specific subfields may contain zero or more user block fields. A non-final user block field contains two user information fields (i.e., information used for decoding at two STAs). A final user block field contains one or two user information fields. The number of user information 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 information field in HE-SIG-A. The user-specific subfields may be encoded separately or independently from the common fields.

[0135] FIG. 12 is a diagram illustrating the MU-MIMO scheme in which multiple users / STAs are assigned to one RU.

[0136] 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 subfield of the HE-SIG-B may include eight user information fields (i.e., four user block fields). The eight user information fields may be assigned to RUs as shown in FIG. 12.

[0137] The user information fields may be configured based on two formats. The user information fields for MU-MIMO allocations may be configured in a first format, and the user information fields for non-MU-MIMO allocations may be configured in a second format. Referring to the example of FIG. 12, user information fields 1 to 3 may be based on the first format, and user information fields 4 to 8 may be based on the second format. The first and second formats may contain bit information of the same length (e.g., 21 bits).

[0138] The user information 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 information field, B0 to B10 include identification information of the corresponding 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 corresponding user, B15 to B18 include modulation and coding scheme (MCS) information applied to the Data field of the corresponding 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 corresponding PPDU.

[0139] The user information 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 information 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 the coding type (e.g., BCC or LDPC) applied to the Data field of the PPDU.

[0140] 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).

[0141] FIG. 13 shows an example of a PPDU format to which the present disclosure can be applied.

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] 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.

[0149] 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}.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] 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.

[0160] 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.

[0161] Preamble puncturing may be applied to the PPDU in Figure 13. Preamble puncturing refers to applying puncturing to a portion of the entire bandwidth of the PPDU (e.g., a secondary 20 MHz band). For example, when an 80 MHz PPDU is transmitted, the STA applies puncturing to the secondary 20 MHz band of the 80 MHz band, and can transmit the PPDU only in the primary 20 MHz band and the secondary 40 MHz band.

[0162] For example, the preamble puncturing pattern may be preset. For example, when a first puncturing pattern is applied, puncturing may be applied only to a secondary 20 MHz band in an 80 MHz band. For example, when a second puncturing pattern is applied, puncturing may be applied only to one of two secondary 20 MHz bands included in a secondary 40 MHz band in an 80 MHz band. For example, when a third puncturing pattern is applied, puncturing may be applied only to a secondary 20 MHz band included in a primary 80 MHz band in a 160 MHz band (or an 80+80 MHz band). For example, when a fourth puncturing pattern is applied, a primary 40 MHz band included in a primary 80 MHz band in a 160 MHz band (or an 80+80 MHz band) is present, and puncturing may be applied to at least one 20 MHz channel that does not belong to the primary 40 MHz band.

[0163] Information about preamble puncturing applied to the PPDU may be included in the U-SIG and / or the EHT-SIG, for example, 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.

[0164] 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).

[0165] 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).

[0166] 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.

[0167] 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.

[0168] 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 subfield, similar to the example of Figure 8. The common field of the EHT-SIG may be omitted, and the number of user-specific subfields may be determined based on the number of users.

[0169] 11, the common field of the EHT-SIG and the user-specific subfield of the EHT-SIG may be coded separately. One user block field included in the user-specific subfield contains information for two user information fields, but the last user block field included in the user-specific subfield may contain one or two user information fields. That is, one user block field of the EHT-SIG may contain up to two user information fields. As in the example of FIG. 12, each user information field may be associated with either MU-MIMO allocation or non-MU-MIMO allocation.

[0170] 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.

[0171] 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).

[0172] 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.

[0173] The EHT-SIG may be configured based on various MCS schemes. As described above, information related to the MCS scheme to be applied to the EHT-SIG may be included in the U-SIG. The EHT-SIG may be configured based on the DCM scheme. For example, of N data tones (e.g., 52 data tones) allocated for the EHT-SIG, a first modulation scheme may be applied to consecutive half of the tones, and a second modulation scheme may be applied to the remaining consecutive half of the tones. That is, the transmitting STA may modulate specific control information onto a first symbol based on a first modulation scheme and allocate it to consecutive half of the tones, and modulate the same control information onto a second symbol based on a second modulation scheme and allocate it to the remaining consecutive half of the tones. As described above, information (e.g., a 1-bit field) regarding whether the DCM scheme 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 a channel in a MIMO environment or an OFDMA environment.

[0174] 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.

[0175] The PPDU in FIG. 13 (ie, the EHT PPDU) may be configured based on the example of the RU arrangement in FIGS.

[0176] 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.

[0177] 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.

[0178] The tone plan for 160 / 240 / 320 MHz may be configured to repeat the pattern of FIG. 9 or FIG. 10 multiple times.

[0179] The PPDU in FIG. 13 may be identified as an EHT PPDU based on the following method.

[0180] 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.

[0181] 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.

[0182] 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. Also, even if the receiving STA detects a repetition of the RL-SIG, if the result of applying modulo 3 to the length value of the L-SIG is detected to be 0, the received PPDU may be determined to be a non-HT, HT, or VHT PPDU.

[0183] 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.

[0184] trigger frame

[0185] FIG. 14 is a diagram illustrating an exemplary format of a trigger frame to which the present disclosure can be applied.

[0186] The trigger frame may allocate resources for one or more TB PPDU transmissions and may request TB PPDU transmissions. The trigger frame may also include other information required by the STAs transmitting TB PPDUs in response.

[0187] 14(a) illustrates an example of an HE variant trigger frame. The trigger frame may include a common info field, a user info list field, and the like in the frame body.

[0188] The common information field illustrated in (b) of Figure 14 may include information that applies commonly to one or more TB PPDU transmissions requested by the trigger frame, such as trigger type, UL length, whether or not a subsequent trigger frame exists (e.g., More TF), whether or not a CS (channel sensing) request is required, UL BW (bandwidth), etc.

[0189] For example, the encoding of the trigger type subfield indicating the trigger type may be implemented as shown in Table 1 below, but is not limited thereto.

[0190] [Table 1]

[0191] The user information list includes zero or more user information fields. Figure 14(c) illustrates an example of an HE variant user information field format. For example, the user information field may include an AID12 subfield, an RU allocation subfield, a UL FEC coding type subfield, a trigger dependent user information field, etc. The RU allocation subfield may indicate the size and location of the RU / MRU. To this end, the RU allocation subfield may be parsed together with the PS160 (primary / secondary 160 MHz) subfield of the user information field, the UL BW subfield of the common information field, etc.

[0192] Figure 14(d) illustrates an example of a trigger dependent user information field on a basic trigger frame. The MPDU MU spacing factor subfield may be used to calculate a value multiplied by the minimum MPDU start interval. The TID aggregation limit subfield may indicate the MPDUs allowed in the A-MPDU carried in the HE TB PPDU and the maximum number of TIDs that a STA can aggregate in the A-MPDU. The Preferred AC subfield may indicate the lowest AC recommended for MPDU aggregation of A-MPDUs included in the HE TB PPDU transmitted in response to the trigger frame.

[0193] Sounding Protocol Sequence

[0194] An HE non-trigger-based (non-TB) sounding sequence may begin with the HE beamformer with an individually addressed HE NDP public frame containing one STA information field, followed by an HE sounding NDP sent to the (single) HE beamformee after 15 s, as shown in (a) of Figure 15. The HE beamformee can receive the HE sounding NDP from the HE beamformer and respond after 15 s by sending an HE compressed beamforming / CQI frame to the HE beamformer.

[0195] If the STA identified by the RA field is a mesh STA, an AP, or an IBSS STA, the AID11 subfield of the STA information field may be set to the AID of the STA identified by the RA field of the HE NDP announcement frame or 0.

[0196] Specifically, an HE beamformer initiating an HE non-TB sounding sequence must transmit an HE NDP announcement frame with a single STA information (Info) field, and if the STA identified by the RA field is a mesh STA, AP, or IBSS member STA, the AID11 field value of the STA information field may be set to the AID of the STA identified by the RA field or 0, rather than 2047. The HE beamformer can initiate an HE non-TB sounding sequence with the HE beamformee to request SU feedback over the entire bandwidth. The HE beamformer does not need to initiate an HE non-TB with an HE NDP announcement frame that has a partial BW information subfield indicating less than the entire bandwidth.

[0197] The HE TB sounding sequence may begin with a broadcast HE NDP announcement frame with two or more STA information fields, followed by an HE beamformer, an HE sounding NDP after 1FS, and a BFRP trigger frame after 1FS, as shown in Figure 15(b). One or more HE beamformees can receive the BFPR trigger frame and respond with an HE compressed beamforming / CQI frame after 1FS. Here, the BFRP trigger frame may include one or more user info fields identifying the HE beamformees.

[0198] The HE beamformer initiating the HE TB sounding sequence can transmit an HE NDP announcement frame including two or more STA information fields and an RA field set to a broadcast address. The HE beamformer can initiate the HE TB sounding sequence to request MU feedback across the entire bandwidth.

[0199] The HE beamformer can initiate an HE TB sounding sequence to request a feedback variant only if the feedback variant is calculated based on parameters supported by the HE beamformee; otherwise, the HE beamformer does not need to request a feedback variant calculated based on parameters not supported by the HE beamformee.

[0200] An HE beamformer transmitting an HE NDP announcement frame to an HE beamformee, which is an AP, TDLS peer STA, mesh STA, or IBSS STA, can include one STA information (info) field on the HE NDP announcement frame and set the AID11 field of the STA information field of the frame to 0.

[0201] An HE beamformer that is an AP and transmits an HE NDP announcement frame to one or more HE beamformees can set the AID11 field of the STA information field that identifies non-AP STAs to the 11 LSB of the AID of the non-AP STA. The HE NDP announcement frame does not need to include STA information fields with the same value in the AID11 subfield.

[0202] An HE beamformer transmitting an HE NDP announcement frame that begins an HE TB sounding sequence may include a STA information field with an AID11 subfield value of 2047 to indicate disallowed subchannels during punctured channel operation. If present, the STA information field with an AID11 value of 2047 may be the first STA information field in the frame. An HE beamformer transmitting an HE NDP announcement frame may not include one or more STA information fields with an AID11 subfield value of 2047.

[0203] As shown in Figure 15(b), the HE beamformer that initiated the HE TB sounding sequence may transmit another BFRP trigger frame in the same TXOP. The HE beamformer may use additional BFRP trigger frames to request HE compressed beamforming / CQI reports from the HE beamformee that have not been processed in a previous BFRP trigger frame, or to request retransmission of an HE compressed beamforming / CQI report. The HE beamformer does not need to transmit a BFRP trigger frame identifying a STA identified in the HE NDP announcement frame of the HE TB sounding sequence unless it is in the same TXOP as the HE TB sounding sequence.

[0204] In the HE TB sounding sequence, the STA information field of the HE NDP public frame requesting SU or MU feedback may indicate the subcarrier grouping (Ng), codebook size, and number of columns (Nc) used by the HE beamformee identified by the STA information field for generating SU or MU feedback. And, in the HE TB sounding sequence, the STA information field of the HE NDP public frame requesting CQI feedback may indicate the Nc used by the HE beamformee identified by the STA information field for generating CQI feedback.

[0205] In addition, the BFRQ trigger frame may not have a trigger dependent common information subfield. The trigger dependent user information subfield of the BFRQ trigger frame may indicate the requested feedback segment of the HE compressed beamforming report in the feedback segment retransmission bitmap subfield.

[0206] If the bit at position n in the subfield (n=0 for LSB, n=7 for MSB) is 1, a feedback segment in which the Remaining Feedback Segment subfield of the HE MIMO control field is n may be requested. If the bit at position n in the subfield is 0, a feedback segment in which the Remaining Feedback Segment subfield of the HE MIMO control field is n may be requested.

[0207] Wireless LAN sensing procedure

[0208] The WLAN sensing procedure (hereinafter referred to as the sensing procedure) refers to a procedure for acquiring cognitive information about the surrounding environment based on information about the channel environment (or state) included in a signal transmitted from a transmitting end to a receiving end. Each STA can provide additional services that can be applied in various ways to real life based on the information about the surrounding environment acquired through the sensing procedure.

[0209] Here, the information about the surrounding environment may include, for example, gesture recognition information, fall detection information, intrusion detection information, user motion detection, health monitoring information, or pet movement detection.

[0210] 16 is an example of a WLAN sensing procedure applicable to the present disclosure. The WLAN sensing procedure may consist of an association phase (or capability advertisement and negotiation phase), a setup phase, a sensing (measurement) phase, and a termination phase (or tear down phase).

[0211] In the association phase (or / and discovery phase), each STA can exchange and associate sensing-related capabilities.

[0212] For example, a sensing initiator (e.g., an AP) that starts a WLAN sensing procedure can receive sensing-related capabilities from one or more sensing responders. Based on the capabilities received from the one or more sensing responders, the sensing initiator can determine whether the one or more sensing responders are capable of sensing and whether they have appropriate sensing capabilities. Based on determining that the one or more sensing responders are capable of sensing and have appropriate sensing capabilities, one or more sensing responders may be coupled to the sensing responders.

[0213] Here, the sensing responder refers to a STA that participates in a WLAN sensing session initiated by a sensing initiator.

[0214] In the setup phase (or the negotiation phase, which is part of the setup phase), a sensing session between STAs may be set up. Furthermore, in the setup phase, the role of the STA associated with sensing and parameters to be used during sensing (or / and IDs associated with the parameters) may be negotiated. The negotiated role and parameters of each STA may be used in the sensing session until it is torn down.

[0215] For example, a sensing group may be formed during the negotiation phase. A sensing group refers to a group of one or more sensing STAs that perform sensing measurements and feedback to each other. Here, a sensing STA refers to a STA that is capable of sensing.

[0216] The setup phase may be divided into a sensing session setup phase and a sensing measurement setup phase, and the sensing session setup phase may precede the sensing measurement setup phase. The sensing session setup phase refers to a phase of forming a sensing session between STAs. The sensing measurement setup phase can negotiate specific operation parameters associated with sensing measurements (e.g., sensing measurement setup ID, role, sensing measurement report type, etc.). Each sensing measurement setup may be mapped to a separate ID.

[0217] The roles of STAs may be defined as sensing initiator, sensing responder, sensing sender, and sensing receiver. Here, a sensing sender refers to a STA that transmits a PDDU used for sensing measurement in a sensing session. A sensing receiver refers to a STA that receives a PPDU from a sensing sender and performs sensing measurement.

[0218] In the sensing phase (or sensing measurement instance phase), the sensing STA transmits a sensing signal (e.g., NDP) to identify a target, receives and measures the sensing signal from the target, and then reports the measurement results.

[0219] A period in which a sensing STA transmits a sensing signal and receives / measures the sensing signal from a target may be defined as a sensing session. A sensing session may consist of one or more sensing measurement instances. That is, a sensing phase may consist of sensing measurements and sensing feedback within a sensing session (or sensing measurement instances that constitute a sensing session).

[0220] That is, the sensing STA can perform sensing measurements and feedback (ie, report) transmission operations in a sensing session.

[0221] There may be one or more sensing measurement setup instances for each sensing measurement setup ID described above, and the sensing measurement instances may also be distinguished by their IDs.

[0222] The teardown phase (or / and sensing measurement setup termination) phase refers to the phase of tearing down the sensing measurement setup defined in the sensing measurement setup phase. That is, the negotiated roles / parameters are not used after termination, and the sensing measurement setup ID / sensing measurement instance ID, etc. may also be returned.

[0223] If there is more than one sensing measurement setup at the time of terminating the sensing measurement setup, the STA may wish to terminate some or all of the setups, however, performing an operation to terminate each of the sensing measurement setups may result in unnecessary overhead.

[0224] The following describes how to tear down / terminate some or all of the sensing measurement setups that are mapped to one or more sensing measurement setup IDs.

[0225] How to complete the sensing measurement setup

[0226] Like the ADDBA request / response frames for BA (block acknowledgment) agreement, new negotiation frames may be defined in the sensing measurement setup phase, and exchange operations of the negotiation frames may be performed.

[0227] A frame transmitted by a STA initiating a sensing measurement setup may be referred to as a sensing measurement setup request frame, and a frame transmitted by a STA in response to the sensing measurement request frame may be referred to as a sensing measurement setup response frame.

[0228] The sensing measurement setup request frame can be transmitted by a sensing initiator, and the sensing measurement setup response frame can be transmitted by a sensing responder. That is, the sensing responder can transmit the sensing measurement setup response frame in response to the sensing measurement setup request frame received from the sensing initiator.

[0229] The sensing measurement setup request frame may be defined as a control frame such as an RTS / CTS or an action frame such as an ADDBA request / response frame. As disclosed in Table 2 (i.e., Public Action Field) and Table 3 (Sensing Measurement Setup Frame Action Field Format), the sensing measurement setup request / response frame may be defined as an action frame.

[0230] [Table 2]

[0231] [Table 3]

[0232] The sensing measurement setup request / response frame may be defined in the form of an encrypted public (protected dual of public) or a new category of sensing encrypted frame. Additionally or alternatively, the sensing measurement setup request / response frame may be defined in the form of a public action field without a subtype. As shown in FIG. 17, when sensing STA1 (i.e., sensing initiator) sends a sensing measurement setup request frame to sensing STA2 (i.e., sensing responder), sensing STA2 can negotiate for sensing by sending a sensing measurement setup response frame to sensing STA1. Furthermore, each of sensing STA1 and sensing STA2 can respond to the received frame by sending an ACK.

[0233] The sensing measurement setup request frame may include an assigned ID (eg, a sensing measurement setup ID), a role, and parameters related to the sensing measurement.

[0234] For example, if the sensing responder accepts the role and / or parameters associated with the sensing measurement in the sensing measurement setup request frame, the sensing measurement setup response frame may not include other roles / corresponding parameters. For another example, if the sensing responder rejects the role and / or parameters associated with the sensing measurement in the sensing measurement setup request frame while proposing other roles / parameters (i.e., acceptable roles / parameters), the sensing measurement setup response frame may include the acceptable role and / or sensing measurement parameter IE.

[0235] That is, the sensing initiator and the sensing responder can perform one or more sensing measurement setups by transmitting and receiving one or more sensing measurement setup response / request frames. When one or more sensing measurement setups exist, the sensing initiator and / or the sensing responder can terminate one or more sensing measurement setups simultaneously.

[0236] The sensing measurement setup termination frame may be defined in the form of a public action frame, an encrypted public (protected dual of public), or a new category of sensing encrypted frame (sensing protected frame), as shown in Tables 2 and 3. The configuration of the sensing measurement setup ID may determine how to terminate the sensing measurement setup.

[0237] Here, the sensing measurement setup ID may be configured in the form of indicating a number such as 0, 1, or 2. The maximum size of the information indicating the sensing measurement setup ID may be, but is not limited to, 1 octet or 4 / 6 bits.

[0238] The following describes in detail how to complete one or more sensing measurement setups.

[0239] FIG. 18 is a flowchart illustrating a process in which a first STA performs a sensing procedure according to an embodiment of the present disclosure.

[0240] 18 and 19, when performing the sensing procedure, the first STA may be a sensing responder and the second STA may be a sensing initiator. The first STA may be a non-AP STA and the second STA may be an AP, but is not limited thereto.

[0241] The first STA may receive at least one sensing measurement setup request frame requesting at least one sensing measurement setup from the second STA (S1810).

[0242] Each of the at least one sensing measurement setup request frames may include a measurement setup ID field, which may indicate a measurement setup ID that identifies an operating parameter assigned to a sensing measurement parameter element used in the corresponding sensing measurement instance.

[0243] In response to the at least one sensing measurement setup request frame, the first STA may transmit at least one sensing measurement setup response frame to the second STA (S1820).

[0244] That is, the first STA may transmit sensing measurement setup response frames corresponding to each of the received sensing measurement setup request frames to the second STA, where at least one sensing measurement setup response frame may include a status code field indicating a response result to at least one sensing measurement setup request frame.

[0245] The first STA may transmit a sensing measurement setup termination frame to the second STA or may receive a sensing measurement setup termination frame from the second STA (S1830).

[0246] Here, the sensing measurement setup end frame may include specific information indicating whether the first STA or the second STA requests to end at least one entire sensing measurement setup, and ii) a measurement setup ID (identifier) ​​field based on the first information.

[0247] For example, the specific information may be indicated by a specific subfield included in the sensing measurement setup end frame, and the specific subfield may consist of one subfield or multiple subfields.

[0248] As an example, the specific subfield may consist of a Terminate All TB (triggered-based) measurement setups subfield and a Terminate All non-TB measurement setups subfield.

[0249] Setting a specific subfield value to 0 means that the values ​​of all TB measurement setup end subfields and all non-TB measurement setup end subfields are set to 0. Setting a specific subfield value to 1 means that the values ​​of all TB measurement setup end subfields and all non-TB measurement setup end subfields are set to 1.

[0250] The All TB Measurement Setup End subfield may indicate whether the first STA and / or the second STA has requested to end all sensing measurement setups configured in the TB case. The All Non-TB Measurement Setup End subfield may indicate whether the first STA and / or the second STA has requested to end all sensing measurement setups configured in the non-TB case.

[0251] Based on the specific subfield value being set to 0, the specific information may indicate that the first STA or the second STA does not request the termination of all of at least one sensing measurement setup (e.g., all sensing measurement setups set in the TB case and all sensing measurement setups set in the non-TB case).

[0252] As yet another example, based on the specific subfield value being set to 1, the specific information may indicate that the first STA or the second STA requests that at least one entire sensing measurement setup be completed.

[0253] A measurement setup ID indicating the ID of one or more specific sensing measurement setups to be terminated among at least one sensing measurement setup may be included in the sensing measurement setup termination frame based on the specific information.

[0254] As an example, the measurement setup ID field may be reserved based on the specific subfield value indicating the specific information being set to 1.

[0255] As yet another example, the measurement setup ID field may indicate the ID of one or more specific sensing measurement setups to be terminated among at least one sensing measurement setup based on the specific subfield value being set to 0. In this case, the size of the measurement setup ID field may be 1 octet.

[0256] Specifically, based on the specific subfield value being set to 0, the sensing measurement setup end frame may include a field indicating the TB / non-TB measurement setup type (TB / non-TB Measurement setup type field).

[0257] As an example, based on the field indicating the TB / non-TB measurement setup type indicating the TB measurement setup type, the measurement setup ID field may indicate the ID of one or more specific sensing measurement setups that are of the TB measurement setup type. As yet another example, based on the field indicating the TB / non-TB measurement setup type indicating the non-TB measurement setup type, the measurement setup ID field may indicate the ID of one or more specific sensing measurement setups that are of the non-TB measurement setup type.

[0258] The first STA may not participate in the sensing measurement instance associated with the terminated sensing measurement setup ID among the at least one sensing measurement setup.

[0259] FIG. 19 is a flowchart illustrating a process in which a second STA performs a sensing procedure according to an embodiment of the present disclosure.

[0260] The second STA may transmit at least one sensing measurement setup request frame requesting at least one sensing measurement setup to the first STA (S1910).

[0261] The second STA may receive at least one sensing measurement setup response frame from the first STA in response to the at least one sensing measurement setup request frame (S1920).

[0262] The at least one sensing measurement setup response frame may include information accepting / rejecting parameters, etc. included in the at least one sensing measurement setup request frame. Additionally or alternatively, the at least one sensing measurement setup response frame may include parameters, etc. associated with the sensing measurement setup proposed by the first STA.

[0263] The second STA may receive a sensing measurement setup end frame from the first STA or may transmit a sensing measurement setup end frame to the first STA (S1930).

[0264] The configuration and related operations of the sensing measurement setup end frame have been described with reference to FIG. 18, so a duplicate description will be omitted.

[0265] The following describes in detail a method for ending one or more sensing measurement setups and the configuration of a sensing measurement setup end frame.

[0266] Example 1

[0267] The corresponding (sensing) measurement setup may be terminated by a field including all (sensing) measurement setup IDs to be terminated. To this end, the number of (sensing) measurement setup IDs to be listed may be indicated. That is, the sensing initiator / sensing responder can send or receive a (sensing measurement setup termination) frame including the (sensing) measurement setup ID to be terminated and / or the number of corresponding (sensing) measurement setup IDs.

[0268] However, this is not limited to this, and if the number of the (sensing) measurement setup IDs can be determined from the length of the frame, the number of other (sensing) measurement setup IDs does not need to be indicated.

[0269] If the frame includes information indicating the number of (sensing) measurement setup IDs, the frame may include a (sensing) measurement setup ID information field that ends with the indicated number.

[0270] For example, as shown in (a) of Figure 20, when a sensing initiator / sensing responder attempts to terminate sensing measurements corresponding to three (sensing) measurement setup IDs (e.g., IDs 0, 2, and 3), the sensing initiator / sensing responder can transmit and receive fields including all of the (sensing) measurement setup IDs 0, 2, and 3. In this case, the fields including all of the IDs 0, 2, and 3 may be included in a sensing measurement setup termination frame.

[0271] Example 2

[0272] The sensing measurement setup IDs to be terminated may be indicated in the form of a bitmap (i.e., a bitmap corresponding to the maximum number of (sensing) measurement setup IDs). That is, the (sensing) measurement setup IDs to be terminated may be indicated by a bitmap.

[0273] As an example, as shown in (b) of Figure 20, when up to 16 (sensing) measurement setup IDs can be indicated (in a 4-bit field), the bitmap may be configured with 16 bits. If the (sensing) measurement setup IDs to be terminated are 1 and 3, the positions / values ​​in the bitmap corresponding to the (sensing) measurement setup IDs 1 and 3 may be set / indicated to 1.

[0274] There may be a trade-off between the first and second embodiments. In the second embodiment, the overhead may be determined by the maximum number of sensing measurement setup IDs, whereas in the first embodiment, the overhead may be determined by the size of the sensing measurement setup ID field and the number of sensing measurement setup IDs to be terminated.

[0275] That is, the smaller the maximum number of sensing measurement setup IDs, the more advantageous the method according to the second embodiment is in terms of overhead. However, when the maximum number of sensing measurement setup IDs is large and the number of measurement setup IDs to be terminated is small, the method according to the first embodiment is more advantageous.

[0276] Example 3

[0277] In addition to or instead of the first and / or second embodiment, all current sensing measurement setup IDs may be terminated.

[0278] As an example, as shown in (a) of Figure 21, if the value of a field indicating whether to terminate all sensing measurement setups (e.g., an "All terminated" field) is 1, this may mean that all current sensing measurement setup IDs are terminated. As an example, the sensing measurement setup termination frame may include an "All terminated" field and may not include any other additional information.

[0279] As yet another example, assume that the value of a field indicating whether all sensing measurement setups are terminated (e.g., an "All terminated" field) is 0. That is, if all sensing measurement setups are not terminated, parameters based on Example 1 and / or Example 2 may be added, as shown in (b) and (c) of FIG. 21. Then, the sensing measurement setup procedure may be performed using parameters based on Example 1 and / or Example 2.

[0280] Specifically, as shown in (b) of Figure 21, the sensing measurement setup termination frame may include an All terminated field set to a value of 0, a field for the number of (sensing) measurement setup IDs to be terminated, and the (sensing) measurement setup IDs to be terminated.

[0281] As shown in (c) of FIG. 21, the sensing measurement setup terminated frame may include an All terminated field set to a value of 0 and a (sensing) measurement setup ID bitmap.

[0282] Example 4

[0283] As described above, if the maximum number of sensing measurement setup IDs is large, the length of the bitmap corresponding to the maximum number of sensing measurement setup IDs may become large. Therefore, a bitmap may be configured based only on the currently set sensing measurement setup IDs. In this case, a separate field may be configured to determine the size of the bitmap.

[0284] The field that determines the size of the bitmap can indicate the size of the bitmap as an exact value / size (e.g., 4 bits, 1 octet) or it can indicate a multiple such as 4 bits / 1 octet (e.g., N value to indicate 1 octet * N value).

[0285] As an example, assume that the maximum number of sensing measurement setup IDs is 16, but the number of currently terminating sensing measurement setup IDs is 3, and the (currently terminating) sensing measurement setup IDs are 0, 2, and 3. In this case, the field that determines the size of the bitmap can indicate 4 bits as the size of the bitmap.

[0286] As yet another example, if the (currently terminating) sensing measurement setup ID is 0, 2, or 5, the field that determines the size of the bitmap may indicate 8 bits as the size of the bitmap. In other words, the size of the bitmap may be flexibly determined depending on the number of sensing measurement setup IDs and / or the measurement setup ID value to be terminated.

[0287] 21(d), the sensing measurement setup end frame may include a field indicating whether all sensing measurement setups are to be ended, a field indicating a (sensing) measurement setup ID bitmap size, and a (sensing) measurement setup ID bitmap field. In this case, the (sensing) measurement setup ID bitmap field may indicate the sensing measurement setup ID to be ended, as described above.

[0288] As shown in (d) of Figure 21, assume that you do not want to terminate all sensing measurement setup IDs (i.e., the field value indicating whether all sensing measurement setups are to be terminated is set to 0), but want to terminate sensing measurement setup IDs 0 and 2. In this case, the (sensing) measurement setup ID bitmap value may be set to 1010 (i.e., indicating sensing measurement setup IDs 0 and 2).

[0289] 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.

[0290] 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.

[0291] 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. Storage media may include high-speed random access memory such as DRAM, SRAM, DDR RAM, or other random access solid-state memory devices, but are not limited to, 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. Memory, or alternatively, non-volatile memory devices within memory, comprise non-transitory computer-readable storage media. 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]

[0292] 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 at least one sensing measurement request frame from a second STA requesting at least one sensing measurement session; transmitting at least one sensing measurement response frame to the second STA in response to the at least one sensing measurement request frame; transmitting a sensing measurement end frame to the second STA or receiving the sensing measurement end frame from the second STA; The method, wherein the sensing measurement end frame includes: i) specific information indicating whether the first STA or the second STA requests to terminate all of the at least one sensing measurement session; and ii) a measurement session ID (identifier) ​​indication field based on the specific information.

2. The specific information is indicated by a specific subfield included in the sensing measurement end frame, When the value of the specific subfield is set to 0, the specific information indicates that the first STA or the second STA does not request to terminate the at least one sensing measurement session; The method of claim 1, wherein the specific information indicates that the first STA or the second STA requests to terminate the at least one sensing measurement session based on the value of the specific subfield being set to 1.

3. The method of claim 2 , wherein the measurement session ID indication field is reserved based on the value of the particular subfield being set to 1.

4. 3. The method of claim 2, wherein the ID of at least one specific sensing measurement session to be terminated among the at least one sensing measurement session is indicated by the measurement session ID indication field based on the value of the specific subfield being set to 0.

5. The method of claim 1 , wherein the size of the measurement session ID indication field is one octet.

6. The method of claim 1 , wherein the first STA does not participate in a sensing measurement instance associated with a terminated sensing measurement session ID among the at least one sensing measurement session.

7. The method of claim 1 , wherein the at least one sensing measurement response frame includes a status code field indicating a response result to the at least one sensing measurement request frame.

8. The first STA is a sensing responder; The method of claim 1 , wherein the second STA is a sensing initiator.

9. 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 at least one sensing measurement request frame from a second STA via the at least one transceiver, the sensing measurement request frame requesting at least one sensing measurement session; transmitting at least one sensing measurement response frame to the second STA via the at least one transceiver in response to the at least one sensing measurement request frame; configured to transmit a sensing measurement end frame to the second STA via the at least one transceiver or receive the sensing measurement end frame from the second STA via the at least one transceiver; The sensing measurement end frame includes: i) specific information indicating whether the first STA or the second STA requests to terminate all of the at least one sensing measurement session; and ii) a measurement session ID (identifier) ​​indication field based on the specific information.

10. 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: transmitting at least one sensing measurement request frame requesting at least one sensing measurement session to a first STA via the at least one transceiver; receiving at least one sensing measurement response frame from the first STA via the at least one transceiver in response to the at least one sensing measurement request frame; configured to receive a sensing measurement end frame from the first STA via the at least one transceiver or transmit the sensing measurement end frame to the first STA via the at least one transceiver; The sensing measurement end frame includes i) specific information indicating whether the first STA or the second STA requests to terminate all of the at least one sensing measurement session, and ii) a measurement session ID (identifier) ​​indication field based on the specific information.

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