Method and apparatus for performing a sensing procedure in a wireless LAN system - Patents.com

Abstract

A method and an apparatus performed in a wireless LAN system are disclosed. As an embodiment of the present disclosure, a method performed by a first STA in a wireless LAN system includes a step of receiving a sensing trigger frame including a sensing trigger subtype field from a second STA, where the sensing trigger subtype field includes information indicating that the sensing trigger frame is an SR2SR sounding trigger frame, and a step of transmitting an SR2SR NDP to at least one STA based on the sensing trigger frame or receiving the SR2SR NDP from the at least one STA in an SR2SR sounding step, where the sensing trigger frame may include information indicating a role of the first STA in the SR2SR sounding step.

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 sensing measurements in a next generation wireless LAN 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 wireless LAN technologies, the IEEE (Institute of Electrical and Electronics Engineers) 802.11 series of standards can be called Wi-Fi. For example, technologies recently introduced to wireless LANs include enhancements for the 802.11ac standard for Very High-Throughput (VHT) and enhancements for the IEEE 802.11ax standard for High Efficiency (HE).

[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 being less likely to infringe on privacy compared to existing sensing technologies. As the frequency range utilized by WLAN technology increases, it becomes possible to obtain precise sensing information, and 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 problem of the present disclosure is to provide a method and apparatus for performing a sensing responder to sensing responder (SR2SR) measurement procedure.

[0006] A further technical problem of the present disclosure is to provide a method and apparatus for directing the role of sensing responders in the SR2SR sounding phase.

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

[0008] A method performed by a first STA according to one embodiment of the present disclosure includes a step of receiving a sensing trigger frame including a sensing trigger subtype field from a second STA, where the sensing trigger subtype field includes information indicating that the sensing trigger frame is an SR2SR (sensing responder to sensing to responder) sounding trigger frame, and a step of transmitting an SR2SR NDP (null data physical protocol data unit (PPDU)) to at least one STA based on the sensing trigger frame or receiving the SR2SR NDP from the at least one STA in an SR2SR sounding step, where the sensing trigger frame may include information indicating the role of the first STA in the SR2SR sounding step.

[0009] According to one embodiment of the present disclosure, a method performed by a second STA includes a step of transmitting a sensing trigger frame including a sensing trigger subtype field to a plurality of STAs including a first STA, and a step of receiving a measurement result for the SR2SR NDP transmitted based on the sensing trigger frame in an SR2SR sounding step from at least one of the plurality of STAs, wherein the sensing trigger frame may include information indicating the role of the first STA in the SR2SR sounding step. Effect of the Invention

[0010] Various embodiments of the present disclosure may provide a method and apparatus for performing a sensing procedure in a wireless LAN system.

[0011] Various embodiments of the present disclosure may provide a method and apparatus for performing an SR2SR measurement procedure.

[0012] Various embodiments of the present disclosure may provide methods and apparatus for directing the role of sensing responders during the SR2SR sounding phase, thereby improving the accuracy of sensing measurements.

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

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

[0015] [Figure 1] 1 is a block diagram illustrating a wireless communication device according to an embodiment of the present disclosure. [Diagram 2]FIG. 1 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure can be applied. [Diagram 3] FIG. 2 is a diagram illustrating a link setup process to which the present disclosure can be applied. [Figure 4] FIG. 13 is a diagram for explaining a backoff process to which the present disclosure can be applied. [Diagram 5] 1 is a diagram for explaining a CSMA / CA base frame transmission operation to which the present disclosure can be applied. [Figure 6] 1 is a diagram for explaining an example of a frame structure used in a wireless LAN system to which the present disclosure can be applied. [Figure 7] FIG. 2 illustrates an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure can be applied. [Figure 8] FIG. 2 is a diagram for explaining an example of a resource unit of a wireless LAN system to which the present disclosure can be applied. [Figure 9] FIG. 2 is a diagram for explaining an example of a resource unit of a wireless LAN system to which the present disclosure can be applied. [Figure 10] FIG. 2 is a diagram for explaining an example of a resource unit of a wireless LAN system to which the present disclosure can be applied. [Figure 11] FIG. 2 illustrates an exemplary structure of an HE-SIG-B field. [Figure 12] FIG. 1 is a diagram for explaining a MU-MIMO scheme in which multiple users / STAs are assigned to one RU. [Figure 13] A figure showing an example of a PPDU format to which the present disclosure can be applied. [Figure 14] A figure showing an example of a trigger frame format to which the present disclosure can be applied. [Figure 15] FIG. 1 is a diagram for explaining an HE Non-TB / TB sounding procedure to which the present disclosure can be applied. [Figure 16] A diagram for explaining the process by which a first STA performs a sensing procedure in one embodiment of the present disclosure. [Figure 17]A diagram for explaining the process by which a second STA performs a sensing procedure in one embodiment of the present disclosure. [Figure 18] FIG. 13 is a diagram for explaining a process of performing an SBP procedure according to one embodiment of the present disclosure. [Figure 19] FIG. 1 is a diagram illustrating a method for performing an SR2SR measurement procedure according to one embodiment of the present disclosure. [Figure 20] FIG. 1 is a diagram illustrating a method for performing an SR2SR measurement procedure according to one embodiment of the present disclosure. [Figure 21] FIG. 1 is a diagram illustrating a method for performing an SR2SR measurement procedure according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, preferred embodiments of the present disclosure will be described in detail 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 show the only embodiment 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 is understood by those skilled in the art that the present disclosure can be implemented without such specific details.

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

[0018] In the present 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 the present disclosure, the term "comprise" or "have" specifies the presence of a referenced feature, step, operation, element, and / or component, but does not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

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

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

[0021] The examples of the present disclosure may be applied to various wireless communication systems. For example, the examples of the present disclosure may be applied to a wireless LAN system. For example, the examples of the present disclosure may be applied to an IEEE 802.11a / g / n / ac / ax standard-based wireless LAN. Note that the examples of the present disclosure may be applied to a newly proposed IEEE 802.11be (or EHT) standard-based wireless LAN. The examples of the present disclosure may be applied to an IEEE 802.11be release-2 standard-based wireless LAN, which corresponds to a further improvement technology of the IEEE 802.11be release-1 standard. Furthermore, the examples of the present disclosure may be applied to a next-generation standard-based wireless LAN after IEEE 802.11be. Also, the examples of the present disclosure may 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 New Radio (NR) series technology of the 3rd Generation Partnership Project (3GPP) standard.

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

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

[0024] The first device 100 and the second device 200 illustrated in Fig. 1 may be referred to as 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 as various terms such as an access point (AP), a base station (BS), a fixed station, a Node B, a base transceiver system (BTS), a network, an artificial intelligence (AI) system, a road side unit (RSU), a repeater, a router, a relay, a gateway, etc.

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

[0026] 1, the first device 100 and the 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 to a medium access control (MAC) layer and a physical layer (PHY) in accordance with the provisions of the IEEE 802.11 standard.

[0027] In addition, the first device 100 and the second device 200 may further support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, etc.) other than the WLAN technology. In addition, the device of the present disclosure may be embodied by various devices such as a mobile phone, a vehicle, a personal computer, an Augmented Reality (AR) device, and a Virtual Reality (VR) device. In addition, the STA of the present specification may support various communication services such as voice calls, image calls, data communications, autonomous driving, machine-type communication (MTC), machine-to-machine (M2M), device-to-device (D2D), and Internet-of-Things (IoT).

[0028] The first device 100 includes one or more processors 102 and one or more memories 104, and may further 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 embody the descriptions, functions, procedures, suggestions, methods, and / or operational flow diagrams in the present disclosure. For example, the processor 102 may process information in the memory 104 to generate a first information / signal, and then transmit a wireless signal including the first information / signal via the transceiver 106. The processor 102 may also receive a wireless signal including a second information / signal via the transceiver 106, and then store information obtained from signal processing of the second information / signal 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 executing the descriptions, functions, procedures, suggestions, methods and / or operational flow diagrams in the present disclosure. Here, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., 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 a radio frequency (RF) unit. In the present disclosure, a device may also refer to a communication modem / circuit / chip.

[0029] The second device 200 may include one or more processors 202, one or more memories 204, and may further 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 flow diagrams disclosed in the present disclosure. For example, the processor 202 may process information in the memory 204 to generate a 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 a 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 executing the descriptions, functions, procedures, suggestions, methods and / or operational flow diagrams disclosed in the present disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., 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 the present disclosure, a device may also refer to a communication modem / circuit / chip.

[0030] The hardware elements of the devices 100, 200 are described in more detail below. Without being limited thereto, one or more protocol layers may be embodied by one or more processors 102, 202. For example, one or more processors 102, 202 may embody one or more layers (e.g., the same functional layers such as PHY, MAC). One or more processors 102, 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 the present disclosure. One or more processors 102, 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or operational flow diagrams in the present 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 in 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 flow diagrams in this disclosure.

[0031] The one or more processors 102, 202 may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The one or more processors 102, 202 may be embodied in hardware, firmware, software, or a combination thereof. As an example, 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) may be included in the one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods, and / or operational flow diagrams disclosed in the present disclosure may be embodied using firmware or software, and the firmware or software may be embodied to include modules, procedures, functions, etc. Firmware or software configured to execute the descriptions, functions, procedures, suggestions, methods and / or operational flowcharts disclosed in the present 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 flowcharts disclosed in the present disclosure may be embodied in firmware or software in the form of code, instructions and / or collections of instructions.

[0032] One or more memories 104, 204 may be coupled to one or more processors 102, 202 and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. 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. Also, the one or more memories 104, 204 may be coupled to the one or more processors 102, 202 by various techniques, such as wired or wireless coupling.

[0033] The 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 flow diagrams of the present disclosure, to one or more other devices. The 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 flow diagrams of the present disclosure, from one or more other devices. For example, the 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, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Also, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. In addition, 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, radio signals / channels, etc., as described, functions, procedures, suggestions, methods, and / or operation flow diagrams disclosed in the present disclosure, via the one or more antennas 108, 208. In the present 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 radio signals / channels, etc., from RF band signals to baseband signals for processing the received user data, control information, radio signals / channels, etc., using one or more processors 102, 202. The one or more transceivers 106, 206 may convert the user data, control information, radio signals / channels, etc., processed using one or more processors 102, 202, from baseband signals to RF band signals. To that end, one or more of the transceivers 106, 206 may include (analog) oscillators and / or filters.

[0034] For example, one of the STAs 100 and 200 can perform operations intended for an AP, and the other of the STAs 100 and 200 can perform operations intended for a non-AP STA. For example, the transceivers 106 and 206 in FIG. 1 can perform operations of 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 of various STAs generating transmission and reception signals and performing data processing and calculations in advance for transmission and 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 (SIG (signal), STF (short training field), LTF (long training field), Data, etc.) included in the PPDU; 2) operations for determining / configuring / obtaining time resources and frequency resources (e.g., subcarrier resources) used for fields (SIG, STF, LTF, Data, etc.) included in the PPDU; 3) operations for determining / configuring / obtaining specific sequences (e.g., pilot sequences, STF / LTF sequences, extra sequences applied to SIGs) used for fields (SIG, STF, LTF, Data, etc.) included in the PPDU; 4) power control operations and / or power saving operations applied to STAs; and 5) operations related to determining / obtaining / configuring / calculating / decoding / encoding an ACK signal, etc. In addition, various information (e.g., information regarding fields / subfields / control fields / parameters / power, etc.) used by various STAs in the following example for determining / obtaining / configuring / calculating / decoding / encoding transmitted / received signals may be stored in memory 104, 204 of FIG. 1.

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

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

[0037] The structure of a wireless LAN system may be composed of a number of components. A wireless LAN supporting STA mobility that is transparent to higher layers may be provided by the interaction of a number of components. A basic service set (BSS) corresponds to a basic building block of a wireless LAN. FIG. 2 illustrates an example in which there are two BSSs (BSS1 and BSS2) and two STAs are included as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). In FIG. 2, an ellipse representing a BSS may be understood to represent a coverage area in which STAs included in the BSS maintain communication. This area may be referred to as a basic service area (BSA). When a STA moves outside a BSA, it cannot directly communicate with other STAs in the BSA.

[0038] Without considering the DS shown in FIG. 2, the most basic type of BSS in a wireless LAN is an independent BSS (IBSS). For example, an IBSS may have a minimal form consisting of only two STAs. For example, assuming that other components are omitted, a BSS1 consisting of only STA1 and STA2, or a BSS2 consisting of only STA3 and STA4, may correspond to representative examples of an IBSS. Such a configuration is possible when the STAs can communicate directly without an AP. In addition, in such a form of wireless LAN, the IBSS is not configured in advance, but may be configured when the LAN requires it, and this may also be called an ad-hoc network. Since an IBSS does not include an AP, there is no centralized management entity that performs a management function. That is, in an IBSS, the STAs are managed in a distributed manner. In an IBSS, all STAs may be mobile STAs, and connection to a distributed system (DS) is not allowed, forming a self-contained network.

[0039] The membership of STAs in a BSS may change dynamically as STAs come and go, enter and leave the BSS domain, 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 structure, a STA needs to be associated with the BSS. Such associations may be configured dynamically and may include the use of Distribution System Services (DSS).

[0040] In a wireless LAN, the direct STA-to-STA distance may be limited by the PHY performance. In some cases, such distance limits are sufficient, but in other cases, communication between STAs at greater distances may be required. A distributed system (DS) may be configured to support extended coverage.

[0041] DS means a structure in which BSSs are interconnected. Specifically, as shown in FIG. 2, a BSS may exist as a component of an expanded form of a network composed of multiple BSSs. 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 not limited to being the same or different. In this way, the flexibility of a WLAN structure (DS structure or other network structure) can be explained in that multiple media are logically different from each other. That is, the WLAN structure may be embodied in various ways, and the WLAN structure may be independently specified according to the physical characteristics of each embodiment.

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

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

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

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

[0046] An ESS is a network of arbitrary size and complexity composed of a DS and a BSS. An ESS may 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). SSID is distinguished from BSSID, which is an identifier of a BSS.

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

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

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

[0050] In step S310, the STA may perform a network discovery operation. The network discovery operation may include a scanning operation of the STA. That is, in order for the STA to access a network, the STA must search for a network that it can join. Before joining a wireless network, the STA must identify a compatible network, and the process of identifying networks that exist in a particular area is called scanning.

[0051] There are two types of scanning methods: active scanning and passive scanning. FIG. 3 illustrates a network discovery operation including an active scanning process. In active scanning, a scanning STA transmits a probe request frame to search for APs in the vicinity while changing channels, and waits for a response to the probe request frame. A responder transmits a probe response frame to the STA that transmitted the probe request frame as a response to the probe request frame. Here, the responder may be the STA that transmitted a beacon frame last in the BSS of the channel being scanned. In the BSS, the AP transmits a beacon frame, so the AP becomes the responder, and in the IBSS, the STAs in the IBSS transmit beacon frames alternately, so the responder is not constant. For example, a 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 and move to the next channel (e.g., channel 2) and perform scanning in the same manner (i.e., sending and receiving a probe request / response on channel 2).

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

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

[0054] The authentication process includes a process in which the STA transmits an authentication request frame to the AP, and in response, the AP transmits an authentication response frame to the STA. The authentication frame used in the authentication request / response corresponds to a management frame.

[0055] The authentication frame may include information such as an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a robust security network (RSN), a finite cyclic group, etc. These are only examples of information that may be included in the authentication request / response frame, and other information may be substituted or additional information may be included.

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

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

[0058] For example, the association request frame may include information on various capabilities, a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, an RSN, a mobility domain, supported operating classes, a Traffic Indication Map Broadcast request (TIM 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 a partial example of information that may be included in the association request / response frame, and other information may be substituted or additional information may be included.

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

[0060] The security setup process of step S340 may include a process of performing a private key setup using, for example, 4-way handshaking using an Extensible Authentication Protocol over LAN (EAPOL) frame, and may be performed by a security method not defined in the IEEE 802.11 standard.

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

[0062] In wireless LAN systems, the basic access mechanism of MAC (Medium Access Control) is the Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) mechanism. The CSMA / CA mechanism is also called the Distributed Coordination Function (DCF) of the IEEE 802.11 MAC, and basically adopts a "listen before talk" access mechanism. According to this type of access mechanism, the AP and / or STA may perform a Clear Channel Assessment (CCA) to sense the wireless channel or medium at a predetermined time interval (e.g., DIFS (DCF Inter-Frame Space)) prior to starting transmission. If the medium is determined to be in an idle status as a result of the sensing, the AP and / or STA may start transmitting a frame through the medium. On the other hand, if the medium is detected to be occupied or busy, the AP and / or STA may not start its own transmission, but may set a delay period (e.g., a random backoff period) for medium access and wait before attempting to transmit a frame. By applying the random backoff period, multiple STAs are expected to wait for different times before attempting to transmit a frame, thereby minimizing collisions.

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

[0064] An operation based on the random backoff period will be described with reference to FIG. 4. When an occupied / busy medium is changed 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 a slot time corresponding to the random backoff count. The random backoff count has a pseudo-random integer value and may be determined to any one of values ​​in the range of 0 to CW. Here, CW is a contention window parameter value. The CW parameter is given an initial value of CWmin, but can take a value twice as large in the case of a transmission failure (e.g., when an ACK for a transmitted frame cannot be received). When the CW parameter value becomes CWmax, data transmission can be attempted while maintaining the CWmax value until data transmission is successful, and when data transmission is successful, the CW parameter is reset to the CWmin value. The CW, CWmin, and CWmax values ​​are determined to be two times as large as the CWmin value. n It is preferably set to -1 (n=0,1,2,...).

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

[0066] In the example of FIG. 4, when a packet to be transmitted arrives at the MAC of STA3, STA3 confirms that the medium is idle for DIFS and can immediately transmit a frame. The remaining STAs monitor the medium for occupied / busy state and wait. In the meantime, data to be transmitted may also occur in each of STA1, STA2, and STA5. When the medium is monitored as idle, each STA can count down the backoff slots according to the random backoff count value selected by each STA after waiting for DIFS. Assume that STA2 selects the smallest backoff count value and STA1 selects the largest backoff count value. That is, the example shows a case where the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1 at the time when STA2 finishes the backoff count and starts frame transmission. STA1 and STA5 stop counting down for a while and wait while STA2 occupies the medium. When STA2 ends its occupation and the medium becomes idle again, STA1 and STA5 wait for DIFS and then resume the backoff count that they had stopped. That is, after counting down the remaining backoff slots by the remaining backoff time, STA5 can start frame transmission. Since the remaining backoff time of STA5 is shorter than that of STA1, STA5 starts frame transmission. While STA2 occupies the medium, STA4 may also have data to transmit. From STA4's perspective, when the medium becomes idle, it waits for DIFS and then counts down the random backoff count value it has selected, and can start frame transmission. The example of FIG. 4 shows a case where the remaining backoff time of STA5 coincidentally matches the random backoff count value of STA4, in which case a collision may occur between STA4 and STA5. When a collision occurs, neither STA4 nor STA5 can receive an ACK, and data transmission will fail. In this case, STA4 and STA5 can select a random backoff count value and count down after doubling the CW value.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 after the remaining backoff time has elapsed.

[0067] As shown in the example of FIG. 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 performed 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 performed after an IFS such as a DIFS or a PIFS (Point coordination function IFS). Subtype frames of the management frame 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 the control frame include Request-To-Send (RTS), Clear-To-Send (CTS), Acknowledgment (ACK), Power Save-Poll (PS-Poll), BlockAck, BlockACKReq, null data packet announcement, and Trigger. If the control frame is not a response frame of the previous frame, it is transmitted after a backoff that is performed after a DIFS has elapsed, and if it is a response frame of the previous frame, it is transmitted without a backoff after a short IFS (SIFS). The type and subtype of the frame may be identified by a type field and a subtype field in a frame control (FC) field.

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

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

[0070] As described above, the CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing, in which the STA directly senses the medium. 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 the 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 to the STA that is currently using or has the authority to use the medium. Therefore, the value set as the NAV corresponds to the period during which the STA that transmits the frame is scheduled to use the medium, and the STA that receives the NAV value is prohibited from accessing the medium during that period. For example, the NAV may be set based on the value of the "duration" field in the MAC header of the frame.

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

[0072] In order to reduce the possibility of collision of transmissions of 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, the carrier sensing of STA3 may determine that the medium is idle. That is, STA1 may correspond to a hidden node to STA3. Or, in the example of FIG. 5, while STA2 is transmitting, the carrier sensing of STA3 may determine that the medium is idle. That is, STA2 may correspond to a hidden node to STA3. By exchanging RTS / CTS frames before data transmission / reception between STA1 and STA2, a STA outside the transmission range of either STA1 or STA2, or a STA outside the carrier sensing range for transmissions from STA1 or STA3, may not attempt to occupy the channel during data transmission / reception between STA1 and STA2.

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

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

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

[0076] When STA1 receives a CTS frame from STA2, it can transmit a data frame to STA2 after SIFS from the point when reception of the CTS frame is completed. When STA2 successfully receives a data frame, it can transmit an ACK frame, which is a response to the data frame, to STA1 after SIFS. When the NAV timer expires, STA3 can determine whether the channel is in use using carrier sensing. When STA3 determines that the channel is not in use by another terminal during the DIFS period after the expiration of the NAV timer, it can attempt channel access after the contention window (CW) with random backoff has passed.

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

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

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

[0080] A basic PPDU frame may include a Short Training Field (STF), a Long Training Field (LTF), a Signal (SIG) field, and a Data field. The most basic (e.g., non-High Throughput (HT)) PPDU frame format may be composed of only Legacy-STF (L-STF), 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) STF, LTF, and SIG fields may be included between the SIG field and the Data field (this will be described later with reference to FIG. 7).

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

[0082] The SIG field may include a RATE field and 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 parity bits, SIG TAIL bits, etc.

[0083] The data field may include a SERVICE field, a PSDU (Physical layer Service Data Unit), PPDU TAIL bits, 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 include data generated / used by a higher layer. The PPDU TAIL bits may be used to return the encoder to a 0 state. The padding bits may be used to adjust the length of the data field to a predetermined unit.

[0084] A 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). A MAC frame is composed of a MAC PDU and may be transmitted / received by a PSDU in the data portion of the PPDU frame format.

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

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

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

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

[0089] The HT PPDU format (IEEE 802.11n) further includes HT-SIG, HT-STF, and HT-LFT(s) fields in 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 be further defined, which corresponds to a format that does not include L-STF, L-LTF, and L-SIG, but is composed of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs, and a Data field (not shown).

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

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

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

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

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

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

[0096] As shown at the top of FIG. 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, and there may be 26 units corresponding to 13 tones on each side of the DC band. 26 units, 52 units, or 106 units may be allocated to other bands. Each unit may be allocated for a STA or a user.

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

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

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

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

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

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

[0103] 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. In addition, in the 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 the 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, 7 DC tones are inserted into the DC band, and there is one 26-RU corresponding to 13 tones on each side of the DC band. In the EHT PPDU, 23 DC tones are inserted into the DC band, and there is one 26-RU on the left and right side of the DC band. In the HE PPDU, there is one null subcarrier between the 242-RUs that are not in the center band, but there are five null subcarriers in the EHT PPDU. In the HE PPDU, one 484-RU does not contain a null subcarrier, but in the EHT PPDU, one 484-RU contains five null subcarriers.

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

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

[0106] Here, the MRU corresponds to a group of subcarriers (or tones) composed of multiple RUs, and the multiple RUs constituting the MRU may be RUs of the same size or may be RUs of 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 may not be set / defined. In addition, the multiple RUs constituting one MRU may be contiguous or not contiguous in the frequency domain.

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

[0108] The RU of the present disclosure may be used for uplink (UL) and / or downlink (DL) communication. For example, when trigger-based UL-MU communication is performed, a STA (e.g., an AP) that transmits a trigger may use trigger information (e.g., a trigger frame or TRS (triggered response scheduling)) 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. Then, the first STA may transmit a first trigger-based (TB) PPDU based on the first RU, and the second STA may transmit a second TB PPDU based on the second RU. The first and second TB PPDUs may be transmitted to the AP in the same time interval.

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

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

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

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

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

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

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

[0116] As a further example, consider the 8-bit RU allocation subfield with a value of 01000y. 2 y 1 y 0 8, 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 assigned to the 106-RU in the MU-MIMO scheme. Specifically, a maximum of eight users / STAs may be assigned to the 106-RU, and the number of users / STAs assigned to the 106-RU is represented by 3-bit information (i.e., y 2 y 1 y 0 For example, the 3-bit information (y 2 y 1 y 0 ) corresponds to a decimal value N, the number of users / STAs assigned to 106-RU may be N+1.

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

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

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

[0120] In the example of FIG. 12, it is assumed that the value of the RU allocation subfield is 01000010. 2 y 1 y 0 In y 2 y 1 y 0 = 010. 010 corresponds to 2 in decimal (i.e., N = 2), and it can be indicated that 3 (= N + 1) users are assigned 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 assigned to the 106-RU in the MU-MIMO manner. As a result, a total of eight users / STAs are assigned to the 20 MHz band / channel, and the user-specific field of HE-SIG-B may include eight user fields (i.e., four user block fields). The eight user fields may be assigned to RUs as shown in FIG. 12.

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

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

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

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

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

[0126] The PPDU in Fig. 13 may be variously named, 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 variously named, such as transmit PPDU, receive PPDU, first type or Nth type PPDU, etc. Also, the EHT PPU can be used in an EHT system and / or a new wireless LAN system that improves the EHT system.

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

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

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

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

[0131] The L-LTF and L-STF in FIG. 13 may be configured in the same manner as the corresponding fields of the PPDU described in FIG. 6 and FIG.

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

[0133] For example, the transmitting STA may apply BCC encoding based on a coding rate of 1 / 2 to the 24-bit information of the L-SIG field. Then, the transmitting STA may 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 index -21, -7, +7, +21}) and DC subcarriers (e.g., {subcarrier index 0}). As a result, 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 the signal of {-1, -1, -1, 1} to subcarrier indexes {-28, -27, +27, +28}. This signal may be used for channel estimation for the frequency range corresponding to {-28, -27, +27, +28}.

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

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

[0136] The U-SIG may include N-bit 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 4us, and the U-SIG may have a total duration of 8us. Each symbol of the U-SIG may be used to transmit 26-bit information. For example, each symbol of the U-SIG may be transmitted and received based on 52 data tones and 4 pilot tones.

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

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

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

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

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

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

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

[0144] For example, the U-SIG may include information regarding 1) a bandwidth field including information regarding the bandwidth, 2) a field including information regarding the MCS technique applied to the EHT-SIG, 3) an indication field including information regarding whether or not a DCM technique is applied to the EHT-SIG, 4) a field including information regarding the number of symbols used for the EHT-SIG, 5) a field including information regarding whether or not the EHT-SIG is generated across the entire band, 6) a field including information regarding the type of EHT-LTF / STF, and 7) a field indicating the length of the EHT-LTF and the CP length.

[0145] Preamble puncturing may be applied to the PPDU in FIG. 13. Preamble puncturing means applying puncturing to a portion of the band (e.g., a secondary 20 MHz band) from the entire band of the PPDU. 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.

[0146] For example, the preamble puncturing pattern may be set in advance. For example, when the first puncturing pattern is applied, puncturing may be applied only to the secondary 20 MHz band in the 80 MHz band. For example, when the second puncturing pattern is applied, puncturing may be applied only to one of the two secondary 20 MHz bands included in the secondary 40 MHz band in the 80 MHz band. For example, when the third puncturing pattern is applied, puncturing may be applied only to the secondary 20 MHz band included in the primary 80 MHz band in the 160 MHz band (or the 80+80 MHz band). For example, when the fourth puncturing pattern is applied, the primary 40 MHz band included in the primary 80 MHz band in the 160 MHz band (or the 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.

[0147] The information regarding the 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 regarding the contiguous bandwidth of the PPDU, and a second field of the U-SIG may include information regarding the preamble puncturing applied to the PPDU.

[0148] For example, the U-SIG and the EHT-SIG may include information about preamble puncturing based on the following method. When the bandwidth of the PPDU exceeds 80 MHz, the U-SIG may be configured in units of 80 MHz individually. For example, when the bandwidth of the 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). Also, 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).

[0149] Additionally or alternatively, the U-SIG and the EHT-SIG may include information regarding preamble puncturing based on the following method: The U-SIG may include information regarding preamble puncturing for the entire band (i.e., information regarding the preamble puncturing pattern). That is, the EHT-SIG may not include information regarding preamble puncturing, and only the U-SIG may include information regarding preamble puncturing (i.e., information regarding the preamble puncturing pattern).

[0150] The U-SIG may be configured in units of 20 MHz. For example, when an 80 MHz PPDU is configured, the 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.

[0151] The EHT-SIG in FIG. 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 4us. Information regarding the number of symbols used for the EHT-SIG may be included in the U-SIG.

[0152] 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, the same as the example of Figure 8. The common field of the EHT-SIG may be omitted, and the number of user-specific fields may be determined based on the number of users.

[0153] 11, the common fields of the EHT-SIG and the user-specific fields of the EHT-SIG may be coded separately. A user block field included in the user-specific fields includes information for two user information fields, but the last user block field included in the user-specific fields may include one or two user fields. That is, a user block field of the EHT-SIG may include up to two user fields. Similarly to the example of FIG. 12, each user field may be associated with a MU-MIMO allocation or a non-MU-MIMO allocation.

[0154] Consistent with 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.

[0155] As in the example of FIG. 11, the common field of the EHT-SIG may include RU allocation information. The RU allocation information may refer to information about the location 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).

[0156] 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.

[0157] The EHT-SIG may be configured based on various MCS schemes. As described above, information related to the MCS scheme applied to the EHT-SIG may be included in the U-SIG. The EHT-SIG may be configured based on the DCM scheme. 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 tones, and a second modulation scheme may be applied to the remaining consecutive half 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 the consecutive half 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 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 environment or an OFDMA environment. The EHT-LTF of FIG. 13 may be used to estimate a channel in a MIMO or OFDMA environment.

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

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

[0160] For example, an EHT PPDU transmitted on a 20 MHz band, i.e., a 20 MHz EHT PPDU, may be configured based on the RU in Fig. 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 Fig. 8. An EHT PPDU transmitted on a 40 MHz band, i.e., a 40 MHz EHT PPDU, may be configured based on the RU in Fig. 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 Fig. 9.

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

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

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

[0164] The receiving STA may determine the type of the received PPDU as 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 as EHT PPDU. If the received PPDU is determined as EHT PPDU, the receiving STA may 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 may determine the received PPDU as EHT PPDU based on 1) the first symbol after the L-LTF signal which is BSPK, 2) an RL-SIG which is consecutive to the L-SIG field and is the same as the L-SIG, and 3) an L-SIG including a Length field in which the result of applying modulo 3 is set to 0.

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

[0166] For example, the receiving STA can determine the type of the received PPDU as non-HT, HT, or VHT PPDU based on the following: For example, if 1) the first symbol after the L-LTF signal is BPSK, and 2) an RL-SIG in which the L-SIG is repeated is not detected, the received PPDU may be determined as 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 as 0, the received PPDU may be determined as a non-HT, HT, or VHT PPDU.

[0167] The PPDU of Figure 13 may be used to transmit and receive various types of frames, for example, the PPDU of Figure 13 may be used to transmit and receive one or more (simultaneous) control frames, management frames, or data frames.

[0168] Trigger frame

[0169] FIG. 14 is a diagram showing an exemplary format of a trigger frame to which the present disclosure can be applied.

[0170] The trigger frame may allocate resources for one or more TB PPDU transmissions, request a TB PPDU transmission, and may also include other information required by the STAs that are to transmit TB PPDUs in response.

[0171] 14A illustrates an example of an HE variant trigger frame. The trigger frame may include a common info field and a user info list field in the frame body.

[0172] 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 there is a subsequent trigger frame (e.g., More TF), whether or not there is a CS (channel sensing) request, UL BW (bandwidth), etc.

[0173] 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.

[0174] [Table 1]

[0175] The user information list includes zero or more user info fields. FIG. 14(c) illustrates 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.

[0176] FIG. 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 may aggregate in the A-MPDU. The Preferred AC subfield may indicate the lowest AC recommended for MPDU aggregation of the A-MPDUs included in the HE TB PPDU transmitted in response to the trigger frame.

[0177] Sounding Protocol Sequence

[0178] 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 SIFS, as shown in (a) of Figure 15. The HE beamformee can receive the HE sounding NDP from the HE beamformer and respond by sending an HE compressed beamforming / CQI frame to the HE beamformer after SIFS.

[0179] 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 to 0.

[0180] 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 may initiate an HE non-TB sounding sequence with the HE beamformee to request SU feedback over the entire bandwidth. The HE beamformer may not initiate an HE non-TB with an HE NDP announcement frame with a partial BW information subfield indicating less than the entire bandwidth.

[0181] The HE TB sounding sequence may begin with a broadcast HE NDP announcement frame with two or more STA information fields by the HE beamformer, an HE sounding NDP after SIFS, and a BFRQ trigger frame after SIFS, as shown in Figure 15(b). One or more HE beamformees may receive the BFPR trigger frame and respond with an HE compressed beamforming / CQI frame after SIFS. Here, the BFRQ trigger frame may include one or more user info fields identifying the HE beamformees.

[0182] The HE beamformer initiating the HE TB sounding sequence may 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 may initiate the HE TB sounding sequence to request MU feedback over the entire bandwidth.

[0183] The HE beamformer may 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 may not request a feedback variant calculated based on parameters not supported by the HE beamformee.

[0184] An HE beamformer transmitting an HE NDP announcement frame to an HE beamformee which is an AP, a TDLS peer STA, a mesh STA or an IBSS STA may include one STA info field on the HE NDP announcement frame and set the AID11 field of the STA info field of the frame to 0.

[0185] 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 a non-AP STA to 11 LSB of the AID of the non-AP STA. The HE NDP announcement frame does not have to include STA information fields with the same value in the AID11 subfield.

[0186] An HE beamformer transmitting an HE NDP announcement frame beginning 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 of 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.

[0187] As shown in FIG. 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 the HE compressed beamforming / CQI report. The HE beamformer may not 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.

[0188] 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 Nc used by the HE beamformee identified by the STA information field for generating CQI feedback.

[0189] 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.

[0190] A feedback segment in which the Remaining Feedback Segment subfield of the HE MIMO control field is n may be requested if the bit in position n (n=0 for LSB, n=7 for MSB) in the subfield 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 in position n in the subfield is 0.

[0191] WLAN Sensing Procedure

[0192] The sensing procedure refers to a procedure of 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 forms in real life based on the information about the surrounding environment acquired through the sensing procedure.

[0193] 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.

[0194] The sensing procedure may comprise at least one of a sensing session setup phase, a sensing measurement setup phase, a sensing measurement instance phase, a sensing measurement setup termination phase, and a sensing session termination phase.

[0195] Here, a sensing session is defined as one period of receiving / measuring a sensing signal after the sensing signal is transmitted, and may be composed of one or more sensing measurement instances.

[0196] A sensing session may consist of multiple sub-sessions, each of which may include a measurement phase and a reporting phase, where a sub-session may be expressed as a sensing burst, a (sensing) measurement instance, or a measurement burst.

[0197] An STA that initiates a sensing procedure by sending a sensing measurement setup request frame or the like can be called a sensing initiator, and an STA that responds to the sensing initiator and participates in the sensing procedure (or sensing session) can be called a sensing responder.

[0198] The role of a STA that initiates or participates in a sensing procedure may be a sensing transmitter and / or a sensing receiver. The sensing transmitter refers to a STA that transmits a PPDU used for measurement in the sensing procedure, and the sensing receiver refers to a STA that receives the PPDU transmitted from the sensing transmitter in the sensing procedure and obtains a measurement result based on the PPDU.

[0199] SBP (sensing by proxy) procedure

[0200] SBP is a procedure that enables a non-AP STA to request WLAN sensing from an AP. An SBP initiator refers to a non-AP STA that transmits an SBP request frame, and an SBP responder refers to an AP that receives an SBP request frame.

[0201] To establish an SBP procedure, an SBP initiator can send an SBP request frame to an AP (i.e., an SBP responder). Upon receiving the SBP request frame, the SBP responder can accept or reject the SBP procedure.

[0202] As an example, to accept an SBP procedure, the SBP Responder can send an SBP Response frame with status code "SUCCESS" to the SBP Initiator. As yet another example, to reject an SBP procedure, the SBP Responder can send an SBP Response frame with status code "REQUEST_DECLINED" (or "REQUEST_REJECTED" or "REQUEST_WITH_SUGGESTED_CHANGES") to the SBP Initiator.

[0203] The SBP responder can send an SBP response frame to the SBP initiator within a predefined period in response to the SBP request frame. If the SBP response frame is not sent within the predefined period or if the status code "REQUEST_DECLINED" (or "REQUEST_REJECTED" or "REQUEST_WITH_SUGGESTED_CHANGES") is sent, the SBP procedure setup can be terminated.

[0204] An SBP Responder that sends an SBP Response frame with the status code "SUCCESS" can initiate a WLAN sensing procedure with one or more non-AP STAs using one or more operating parameters indicated in the SBP Request frame that requests the SBP procedure. An SBP Initiator can participate in the WLAN procedure as a Sensing Responder.

[0205] An SBP initiator can request an SBP responder to initiate a WLAN sensing procedure that enables the sensing responder to perform sensing measurements using the NDP sent by another sensing responder.

[0206] An SBP procedure may be terminated after the last SBP report frame is sent by the SBP responder. Additionally or alternatively, an SBP procedure may be terminated by an SBP termination frame sent by the SBP initiator or the SBP responder.

[0207] R2R (responder to responder) sensing measurement procedure

[0208] As described above, to perform sensing measurement, a non-AP STA (i.e., an SBP requesting STA or an SBP initiator) can transmit an SBP request frame to an AP (i.e., an SBP responder) to request that the AP perform sensing measurement on its behalf. The AP that receives the SBP request frame can transmit an SBP response frame to the non-AP STA to indicate whether or not it will perform measurement in response to the SBP request.

[0209] The above-mentioned procedure allows the SBP initiator and the SBP responder to perform sensing measurements through the SBP procedure setup. In this case, an R2R (or SR2SR (sensing responder to sensing responder) sensing procedure may be used to improve performance and efficiency for the sensing measurements.

[0210] In the basic wireless communication system, an operation of indicating the type of a sensing trigger frame in a sensing trigger subtype field of the sensing trigger frame and an operation of determining the role of a sensing STA are defined. However, in the basic wireless communication system, an operation of performing an R2R sounding step in an R2R trigger frame and an operation of indicating the role of each STA in the R2R sounding step are not defined.

[0211] In the following, we describe a procedure for performing R2R sensing measurements and a method for defining new trigger frame variants for use in the R2R sensing procedure.

[0212] 16 is a diagram for explaining a process in which a first STA performs a sensing procedure according to an embodiment of the present disclosure. In FIG. 16 and FIG. 17, the first STA is a non-AP STA and the second STA is an AP, but is not limited thereto.

[0213] The first STA can receive a sensing trigger frame including a sensing trigger subtype field from the second STA (S1610).

[0214] As an example, the sensing trigger frame may include a trigger dependent common information subfield, which may include a sensing trigger subtype field indicating a variant (or subtype) of the sensing trigger frame.

[0215] In this case, the value of the sensing trigger subtype field may be set to 4. The value of the sensing trigger subtype field set to 4 may correspond to (i.e., be encoded with) information indicating that the sensing trigger frame is an SR2SR (sensing responder to sensing to responder) sounding trigger frame.

[0216] That is, the first STA can receive a sensing trigger frame from the second STA, and can determine that the sensing trigger frame is an SR2SR sounding trigger frame based on a sensing trigger subtype field included in the sensing trigger frame.

[0217] The sensing trigger frame may include information indicating the role of the first STA in the SR2SR sounding stage. Specifically, the sensing trigger frame (i.e., the SR2SR sounding trigger frame) may include a single transmitter user information field and one or more receiver user information fields.

[0218] In the following description, the SR2SR sounding trigger frame is described as including one sender user information field, but is not limited to this. The SR2SR sounding trigger frame may include one or more sender user information fields and one or more recipient user information fields.

[0219] As an example, the sender user information field may include an AID12 / USD12 subfield, a Tx (transmission) / Rx (reception) subfield, an SR2SR Rep subfield, an SS allocation / RA (random access)-RU information subfield, a UL target receive power subfield, etc.

[0220] The one or more recipient user information fields may include an AID12 / USID12 sub-field, a Tx / Rx sub-field, and a TX AID12 / USID12 sub-field, etc.

[0221] The AID12 / USD12 subfield of the sender user information field may contain the AID of the STA that is taking on the role of the SR2SR sensing sender (i.e., the non-AP STA that sends the NDP during the SR2SR sounding phase). The TX AID12 / USD12 subfield of the receiver user information field may have the same value as the AID12 / USD12 subfield of the sender user information field.

[0222] The Tx / Rx subfield may indicate the role of the SR2SR sensing responder addressed in the SR2SR sounding stage. That is, information indicating the role of the first STA may be indicated by the Tx / Rx subfield included in the sender user information field or the receiver user information field. The Tx / Rx subfield may be configured with 1 bit, but is not limited thereto.

[0223] As an example, the Tx / Rx subfield value of the sender user information field may be set to 0. The Tx / Rx subfield value of the recipient user information field may be set to 1.

[0224] The SR2SR Rep subfield may indicate the number of HE-LTF repetitions in the HE Ranging NDP of the non-AP STA indicated in the AID12 / USID12 subfield. The SR2SR Rep subfield may be set to a value obtained by subtracting 1 from the number of HE-LTF repetitions.

[0225] The sender user information field may include at least one of the following: information related to the spatial streams allocated to the first STA (e.g., the number of spatial streams) or the size of the LTF. As an example, at least one of the information related to the spatial streams allocated to the first STA or the size of the LTF may be indicated by the SS allocation / RA-RU information.

[0226] Based on the role of the first STA as the SR2SR sensing sender, the sender user information field may include the AID of the first STA, and the first STA can decode the information (e.g., Tx / Rx subfield, etc.) included in the sender user information field.

[0227] As another example, the AID of the first STA may be included in the specific recipient user information field based on the role of the first STA as an SR2SR sensing recipient (i.e., a non-AP STA receiving an NDP in the SR2SR sounding phase). In this case, the first STA can decode information (e.g., Tx / Rx subfield, etc.) included in the recipient user information field.

[0228] As before or / and at step S1610, the first STA may transmit to the second STA an SR2SR field (e.g., an SR2SR support (sub) field) indicating information indicating that the first STA supports SR2SR sounding. That is, the SR2SR support (sub) field may indicate whether a TB (trigger based) sensing measurement instance includes an SR2SR sounding step.

[0229] In this case, the SR2SR support (sub)field may be transmitted to the second STA in a frame related to sensing measurement setup (eg, sensing measurement setup request / response frame, sensing measurement setup query frame, etc.).

[0230] Additionally or alternatively, the SR2SR support (sub)field may be transmitted or received in association request / response frames, reassociation request / response frames, probe response frames, etc.

[0231] In the SR2SR sounding step, the first STA may transmit an SR2SR NDP to at least one STA or receive an SR2SR NDP from at least one STA based on the sensing trigger frame (S1620).

[0232] When the role of the first STA is an SR2SR sensing sender, the first STA can send an SR2SR NDP to at least one STA (i.e., another non-AP STA acting as an SR2SR sensing receiver). At this time, the at least one non-AP STA can perform sensing measurement based on the SR2SR NDP.

[0233] Here, at least one STA acting as an SR2SR sensing receiver may also receive an SR2SR sensing trigger frame from the second STA, and at least one receiver information field included in the SR2SR sensing trigger frame may correspond to at least one STA acting as an SR2SR sensing receiver.

[0234] As another example, when the role of the first STA is an SR2SR sensing receiver, the first STA may receive an SR2SR NDP from a STA acting as an SR2SR sensing sender. In this case, the first STA may perform sensing measurement based on the received SR2SR NDP.

[0235] The SR2SR NDP may be transmitted in a bandwidth of 160 MHz or less, but is not limited thereto, and may be transmitted in a bandwidth of 320 MHz or more. The SR2SR NDP may be embodied in a form in which the data field is omitted from the exemplary PPDU formats of Figures 6, 7, and 13. However, this is only one embodiment, and the SR2SR NDP may be configured based on another PPDU format.

[0236] For example, when the role of the first STA is an SR2SR sensing receiver, the first STA may receive a frame requesting a sensing measurement result performed by the SR2SR NDP from the second STA. In this case, the first STA may transmit a frame including the sensing measurement result to the second STA.

[0237] The method performed by the first STA described in the example of Fig. 16 may be performed by the first device 100 of Fig. 1. For example, one or more processors 102 of the first device 100 of Fig. 1 may be configured to receive a sensing trigger frame including a sensing trigger subtype field from a second STA via one or more transceivers 106. The one or more processors 102 may be configured to transmit an SR2SR NDP to at least one STA via one or more transceivers 106 based on the sensing trigger frame in the SR2SR sounding stage, or to receive an SR2SR NDP from at least one STA via one or more transceivers 106.

[0238] Additionally, the one or more memories 104 of the first device 100 may store instructions for performing the method described in the example of FIG. 16 when executed by the one or more processors 102 .

[0239] FIG. 17 is a diagram for explaining a process in which a second STA performs a sensing procedure according to one embodiment of the present disclosure.

[0240] The second STA can transmit a sensing trigger frame including a sensing trigger subtype field to a plurality of STAs including the first STA (S1710).

[0241] As an example, the second STA may configure an SR2SR sounding trigger frame, which is a variant of the sensing trigger frame, and may transmit the SR2SR sounding trigger frame, which includes a single sender user field and one or more receiver user fields, to multiple STAs, including the first STA.

[0242] The second STA may receive a measurement result for the SR2SR NDP transmitted based on the sensing trigger frame in the SR2SR sounding stage from at least one of the multiple STAs (S1720).

[0243] Here, at least one STA among the multiple STAs may refer to one or more SR2SR sensing receivers that perform sensing measurements based on the NDP transmitted by the SR2SR sensing sender.

[0244] Specifically, the second STA may transmit a frame requesting a sensing measurement result performed by the SR2SR NDP to at least one STA that is an SR2SR sensing receiver. The second STA may receive a frame including the sensing measurement result from at least one STA.

[0245] As an example of the present disclosure, the second STA may be an SBP responder that receives an SBP request frame from an SBP (sensing by proxy) initiator (e.g., a specific non-AP STA).

[0246] The SBP request frame may include parameters related to the SBP procedure and the sensing measurement. The second STA may send an SBP response frame to the SBP initiator. In this case, the SBP response frame sent by the SBP responder to the SBP initiator may include a status code for at least one of the parameters related to the SBP procedure or the sensing measurement.

[0247] The method performed by the second STA described in the example of Fig. 17 may be performed by the second device 200 of Fig. 1. For example, one or more processors 202 of the second device 200 of Fig. 1 may be configured to transmit a sensing trigger frame including a sensing trigger subtype field to a plurality of STAs including the first STA via one or more transceivers 206. The one or more processors 202 may be configured to receive a measurement result for the SR2SR NDP transmitted based on the sensing trigger frame in the SR2SR sounding stage from at least one STA of the plurality of STAs via the one or more transceivers 206.

[0248] Additionally, the one or more memories 204 of the second device 200 may store instructions for performing the method described in the example of FIG. 17 when executed by the one or more processors 202 .

[0249] Hereinafter, the SBP procedure, the procedure for performing R2R sensing measurement, and the configuration of the associated trigger frame will be described in detail.

[0250] Example 1

[0251] Example 1 relates to operation through the SBP procedure and sensing measurement setup phase.

[0252] An SBP initiator and an SBP responder performing an SBP procedure can transmit and receive SBP request / response frames to each other to transmit and receive information regarding SBP execution during the SBP procedure setup phase. In this case, the SBP procedure setup phase for performing an SBP procedure may be configured as shown in FIG.

[0253] As shown in FIG. 18, an SBP initiator (i.e., a non-AP STA) can send an SBP setup request frame to a sensing SBP responder (i.e., an AP) to request sensing measurements from the sensing SBP responder during the SBP procedure setup phase.

[0254] The SBP setup request frame may include information related to sensing parameters for performing sensing measurements. The sensing parameters may include information on the presence or absence of R2R measurement support, information related to Tx or Rx operation during R2R measurement, and / or information indicating the role during R2R measurement.

[0255] An SBP responder (i.e., AP) that receives an SBP request frame can send an SBP response frame to the SBP initiator that includes information about parameters related to the execution of the SBP procedure, information about whether R2R measurement is supported, information related to Tx or Rx operation during R2R measurement, and instruction information for the role during R2R measurement.

[0256] Information regarding the presence or absence of R2R measurement support may be indicated in an R2R support field. As an example, the R2R support field may be configured with 1 bit. When the R2R support field value is set to 1 (or 0), this may indicate that R2R measurement is supported. When the R2R support field value is set to 0 (or 1), this may indicate that R2R measurement is not supported.

[0257] Additionally or alternatively, the R2R assistance field may consist of a Tx assistance field and an Rx assistance field that contain information regarding the Tx and Rx operations, respectively, of the non-AP STA during the R2R measurement.

[0258] Here, the information on Tx operation indicated by the Tx Support field may include information on whether the non-AP STA is operating as an (R2R) sensing transmitter during R2R measurement, and the information on Rx operation indicated by the Rx Support field may include information on whether the non-AP STA is operating as an (R2R) sensing receiver during R2R measurement.

[0259] As an example, the Tx support field indicates whether or not to act as an R2R sensing sender in R2R measurement (i.e., whether or not to support R2R NDP transmission, etc.), and may be configured with 1 bit.

[0260] As an example, when the Tx Support field value is set to 1, this may indicate supporting R2R NDP transmission (or acting as a sender in R2R measurements), and when the Tx Support field value is set to 0, this may indicate not supporting R2R NDP transmission (or acting as a sender in R2R measurements).

[0261] The Rx assistance field indicates whether or not to operate as an R2R sensing receiver in R2R measurement (i.e., whether or not to receive and report an NDP transmitted by a non-AP), and may be composed of 1 bit.

[0262] As an example, when the Rx Assistance field value is set to 1, this may indicate that the device supports performing NDP measurements and sending feedback (i.e., operating as an R2R sensing receiver in R2R measurements). When the Rx Assistance field value is set to 0, this may indicate that the device does not support performing NDP measurements and sending feedback (i.e., operating as an R2R sensing receiver in R2R measurements).

[0263] As described above, the R2R support field (i.e., 2 bits) may be composed of a Tx support field and an Rx support field. In this case, if a non-AP or / and AP does not support R2R, the 2-bit values ​​constituting the R2R support field may be set to 0. That is, when the 2-bit values ​​constituting the R2R support field are all set to 0, it can be indicated that the corresponding non-AP or / and AP does not support R2R.

[0264] As yet another example, the R2R support field may be configured as one field without separate subfields for Tx and Rx, and the R2R support field may indicate whether the corresponding non-AP or / and AP operates as an R2R sensing sender or an R2R sensing receiver.

[0265] For example, assume that one bit (e.g., an R2R assistance field or / and another Tx / Rx indication field) indicates the operation of a non-AP STA in an R2R measurement procedure. When the one-bit value is set to 0, this can indicate that the non-AP STA operates as an R2R sensing receiver. When the one-bit value is set to 1, this can indicate that the non-AP STA operates as an R2R sensing sender.

[0266] As an example, when the operation of a non-AP STA is indicated by the one bit (e.g., the Tx / Rx indication field), the one bit may be used together with the R2R support field to indicate whether R2R measurement is supported and what operation the non-AP will perform during R2R measurement.

[0267] As yet another example, the Tx / Rx indication field may indicate a role of a non-AP STA in R2R measurement. Thus, the Tx / Rx indication field may be used for indicating the role of R2R, and the name of the Tx / Rx indication field may be defined as an R2R role indication (sub)field.

[0268] During R2R measurement procedure setup, the R2R support indication and the Tx / Rx indication (or the R2R role indication) may be transmitted and received by the request frame and the response frame. If the R2R measurement is not supported because the R2R support indication field value is set to 0, the decoding of the Tx / Rx indication (or the R2R role indication) field may be ignored or reserved.

[0269] Example 2

[0270] Example 2 relates to a method for exchanging information related to R2R measurement in a sensing measurement setup procedure.

[0271] Specifically, in order for an SBP responder (i.e., AP) to perform sensing measurements after the SBP setup phase, the presence or absence of R2R measurements may be set in a sensing measurement setup phase performed together with a non-AP STA. That is, information related to R2R measurements may be exchanged between the AP and the non-AP STA in the sensing measurement setup procedure.

[0272] In this case, whether to perform / support R2R measurement and the Tx / Rx operation / role of the non-AP STA in the R2R measurement may be indicated in the R2R support field and the Tx / Rx indication (or R2R role indication) field.

[0273] At least one of the R2R support field and the TX / Rx indication (or the R2R role indication) field may be included in the sensing measurement parameter field, i.e., at least one of the R2R support field and the TX / Rx indication (or the R2R role indication) field may be transmitted or received in the sensing measurement parameter field included in the sensing measurement setup request frame / response frame.

[0274] The R2R indication field and / or TX / Rx indication (or R2R role indication) field included in the sensing measurement setup request / response frame may be configured as described above in the first embodiment.

[0275] Through the measurement setup between the SBP responder (ie, AP) and the non-AP STAs participating in the SBP to perform sensing measurements, the AP can learn information about the non-AP STAs assisting in the R2R measurements.

[0276] Example 3

[0277] The third embodiment relates to a procedure for performing sensing measurements between non-AP STAs in which an AP supports R2R measurements.

[0278] As described above, information regarding the presence or absence of R2R measurement support and the role of a non-AP STA during R2R measurement may be exchanged during the SBP procedure setup phase or / and the sensing measurement setup phase.

[0279] As an example of the present disclosure, an AP (i.e., an SBP responder) can trigger an NDP transmission by transmitting a trigger frame to a specific non-AP STA (e.g., a non-AP STA acting as a sensing responder / initiator in an SBP procedure). The operation related to this will be specifically described in Example 3-1.

[0280] As yet another example of the present disclosure, the AP may perform the R2R measurement procedure by transmitting an SBP trigger frame including a user field for one or more non-AP STAs that perform the R2R measurement. The operation related to this will be specifically described in Example 3-2.

[0281] As yet another example of the present disclosure, the AP may transmit an R2R request frame to a non-AP STA that is to perform R2R measurement to request the non-AP STA to perform R2R measurement. The operation related to this will be described in detail in Example 3-3.

[0282] Example 3-1

[0283] As shown in Figure 19, an AP (i.e., an SBP responder) can trigger an NDP transmission by sending a trigger frame to non-AP STA 1, which acts as a responder / initiator in the SBP procedure. Non-AP STA 1 can perform R2R measurements by sending an NDP to non-AP STA 2.

[0284] Specifically, an AP that has identified a non-AP STA that supports R2R measurement through the SBP procedure setup can transmit a trigger frame to non-AP STA 1 to request NDP transmission from non-AP STA 1 in order to perform R2R measurement in SBP.

[0285] As shown in FIG. 19, the trigger frame that the AP transmits to non-AP STA 1 performing SBP to request NDP transmission may be defined as an SBP sensing trigger variant of the sensing trigger frame.

[0286] As yet another example, a variant of the sensing trigger frame that the AP transmits to non-AP STA 1 to request NDP transmission may be a sensing trigger variant for R2R measurement / transmission.

[0287] Here, the sensing trigger variant for R2R measurement / transmission may be defined as an R2R sensing trigger variant or an R2R sounding trigger variant.

[0288] The trigger frames defined above (i.e., the trigger frames defined as the R2R sensing / sounding trigger variants) are not limited to the SBP procedure and may be used in other R2R sensing procedures.

[0289] For convenience of explanation in the present disclosure, the trigger frame transmitted by the AP is named, but not limited to, an SBP sensing trigger variant. The trigger frame transmitted by the AP may be defined as a sensing trigger frame for R2R measurement transmission (i.e., a trigger frame defined as an R2R sensing / sounding trigger variant) as described above.

[0290] Furthermore, the trigger frame transmitted by the AP is not limited to the SBP procedure and the subsequent R2R measurement procedure, but may also be applied to other R2R procedures.

[0291] The SBP procedure trigger variant may be indicated in a trigger dependent common information subfield of the sensing trigger frame. For example, the SBP procedure trigger variant may be indicated in a sensing trigger subtype field included in the trigger dependent common information subfield as shown in Table 2 below.

[0292] [Table 2]

[0293] However, Table 2 is merely an example, and the SBP sensing trigger variant (or the R2R sensing trigger variant) may be indicated by another sensing trigger subtype subfield value (e.g., any one of 4 to 15). As an example of the present disclosure, when a trigger frame set as an SBP / R2R sensing trigger (sub)variant is transmitted by an AP, the TA (transmitter address) of the trigger frame may be set to the address of the AP, and the RA (receiver address) may be set to a broadcast ID.

[0294] The trigger frame configured as the SBP / R2R sensing trigger (sub) variant may include one user field. As shown in Fig. 19, non-AP STA 1 and non-AP STA 2 performing / supporting R2R sensing measurement can know that R2R sensing measurement is being performed by receiving the trigger frame transmitted by the AP (for R2R sensing measurement).

[0295] A trigger frame configured as an SBP / R2R sensing trigger (sub)variant may include an R2R sensing indication bit to indicate an R2R sensing measurement. In this case, the R2R sensing indication bit may be transmitted in a trigger dependent common information subfield of the trigger frame.

[0296] As yet another example of the present disclosure, when a trigger frame configured with an SBP / R2R sensing trigger (sub)variant is transmitted by an AP, the TA of the trigger frame may be set to the address of the AP, and the RA may be set to the address of a non-AP STA (e.g., non-AP STA 1) transmitting an NDP (i.e., the address of the non-AP STA).

[0297] Referring to FIG. 19, since the RA of the trigger frame is set to non-AP STA 1 which transmits NDP, another signal may be transmitted before transmitting the trigger frame to inform non-AP STA 2 which performs R2R sensing that R2R sensing is being performed.

[0298] For example, before transmitting the trigger frame, the AP may transmit a signal informing non-AP STA 1 and non-AP STA 2 configured for R2R sensing of the execution of R2R sensing, or only to non-AP STA 2. Non-AP STA 2 performing / supporting R2R sensing that receives the signal may confirm that R2R sensing is being performed and may prepare to receive NDP for R2R sensing.

[0299] As described above, the trigger frame configured as the SBP / R2R sensing trigger (sub)variant is used to trigger an NDP transmission and may include one user field.

[0300] As an example, the user field (for SBP / R2R) of the trigger frame may include AID information, BW / allocation information, "GI+LTF size (or / and type)" information, and NSS (number of spatial stream) information, etc.

[0301] Here, the AID information may include ID information for a non-AP STA that transmits an NDP for R2R measurement.

[0302] And, the BW / allocation information may include BW information for NDP transmission. The BW / allocation information may be configured with the same two bits as the UL BW of the common information field of the trigger frame (i.e., a bit indicating the BW in which the NDP is transmitted). The BW in which the NDP is transmitted may indicate one of 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 80+80 MHz.

[0303] As yet another example, the BW / allocation information may be configured with 3 bits. In this case, the BW / allocation information may also indicate a BW of 320 MHz or more as the BW in which the NDP is transmitted.

[0304] As an example, the BW in which the NDP is transmitted as indicated by the BW / allocation information may be configured to be smaller than or equal to the UL BW in the common information field of the trigger frame.

[0305] As an example, the BW / allocation information on the user information field included in the trigger frame may include puncturing information. That is, the BW / allocation information may be configured with 5 bits to indicate the puncturing information. A non-AP STA can check the BW in which the NDP is transmitted by the UL BW subfield of the common information field of the trigger frame, and can check the information to be punctured in the BW by the BW / allocation information field.

[0306] The "GI+LTF size (or / and type)" information may be used to indicate information about the GI and LTF size used when transmitting an NDP. Specifically, since a non-AP STA transmits an NDP using the SU format, the GI and LTF size can be confirmed from the "GI+LTF size (or / and type)" information.

[0307] Here, the "GI+LTF size (or / and type)" information included in the user information field may be configured to be different from the "GI+LTF type" information transmitted in the common information field of the trigger frame.

[0308] As an example, the "GI+LTF size (or / and type)" information may be composed of two bits as shown in Table 3 below.

[0309] [Table 3]

[0310] As yet another example of the present disclosure, when a trigger frame configured as an SBP / R2R sensing trigger (sub)variant is transmitted, the "GI+LTF size subfield" of the common information field of the trigger frame may be configured according to the above-mentioned configuration (e.g., a configuration according to Table 3). Then, the "GI+LTF size subfield" of the common information field of the trigger frame may indicate information on the GI and LTF type (or / and size) for NDP transmission using the SU format.

[0311] As an example, when the common information field of the trigger frame includes a “GI+LTF size subfield” configured as described above, the user information field of the trigger frame does not need to include a “GI+LTF size subfield”.

[0312] The NSS information may indicate the number of spatial streams allocated when transmitting the NDP. As an example, the NSS information may be composed of 3 bits and may indicate any one of 1 to 8 as the number of spatial streams.

[0313] 19, a non-AP STA 1 that receives an SBP / R2R (or SR2SR) sensing trigger frame from an AP can transmit an NDP for R2R measurement to other non-AP STAs. In this case, the NDP may be configured using a SU PPDU format.

[0314] As an example, the NDP transmitted by non-AP STA 1 is defined as an R2R NDP, and the R2R NDP transmitted after receiving a trigger frame may be configured using the HE NDP format or the EHT NDP format.

[0315] Non-AP STA 2, which receives the R2R NDP transmitted by non-AP STA 1, can use the NDP to measure the channel between non-AP STA 1 and non-AP STA 2. In order to have non-AP STA 2 feed back the measured channel information, the AP can transmit a feedback request frame to non-AP STA 2 to request feedback.

[0316] The non-AP STA 2 that receives the feedback request frame can transmit channel state information (CSI) to the AP using a report parameter included in the feedback request frame.

[0317] As shown in FIG. 19, each frame (e.g., trigger frame, NDP, feedback (request) frame, etc.) may be transmitted at SIFS intervals, but is not limited thereto. That is, various types of IFS may be applied for the transmission interval of each frame. As an example, an IFS interval greater than SIFS may be used for the interval between feedback request frames and feedback report frames.

[0318] Example 3-2

[0319] When an AP transmits an SBP / R2R (or SR2SR) sensing trigger frame to perform R2R measurement, the trigger frame may include user (information) fields for two non-AP STAs that will perform R2R measurement.

[0320] The SBP / R2R trigger frame may be a (sub)variant of the sensing trigger frame, which may include information of a Tx non-AP STA (i.e., a non-AP STA acting as a sender) and a Rx non-AP STA (i.e., a non-AP STA acting as a receiver) performing the R2R procedure.

[0321] An indication for the (sub)variant of the trigger frame (i.e., SBP (sub)variant or / and (sub)variant for R2R measurement / transmission) may be given in the trigger subordinate common information field of the sensing trigger frame (i.e., the sensing trigger subtype subfield of the trigger subordinate common information field), as described in Example 3-1.

[0322] The trigger frames defined above (i.e., the trigger frames defined as the R2R sensing / sounding trigger variants) are not limited to the SBP procedure and may be used in other R2R sensing procedures.

[0323] For convenience of explanation in the present disclosure, the trigger frame transmitted by the AP is named an SBP sensing trigger (sub) variant, but is not limited thereto. The trigger frame transmitted by the AP may be defined as a sensing trigger frame for R2R measurement transmission (i.e., a trigger frame defined as an R2R sensing / sounding trigger variant) as described above.

[0324] Furthermore, the trigger frame transmitted by the AP is not limited to the SBP procedure and the subsequent R2R measurement procedure, but may also be applied to other R2R procedures.

[0325] As an example of the present disclosure, when a trigger frame configured as an SBP / R2R sensing trigger (sub)variant is transmitted by an AP, the TA of the trigger frame may be set to the address of the AP, and the RA may be set to a broadcast ID or a multicast ID.

[0326] A trigger frame configured as an SBP / R2R sensing trigger (sub)variant may include multiple user (information) fields (e.g., two user (information) fields). For example, the user (information) fields included in the trigger frame may be configured with user (information) fields for the Tx STA and the Rx STA.

[0327] User (information) fields for Tx STA and / or Rx STA may include AID information, Tx / Rx operation or R2R role indication information, BW / allocation information, "GI+LTF size (or / and type)" information, NSS information, and measurement ID information, etc.

[0328] Here, the AID information may include ID information for a non-AP STA performing R2R measurement. The AID information may include an ID for a Tx non-AP STA or an ID for a Rx non-AP STA.

[0329] The Tx / Rx operation or R2R role instruction information may include information for instructing the role or Tx / Rx operation of a non-AP STA during R2R measurement.

[0330] As an example, the Tx / Rx operation or R2R role indication information may be composed of one bit. When the bit value corresponding to the Tx / Rx operation or R2R role indication information is set to 0 (or 1), it can indicate the Rx operation or the role of the receiver. And when the bit value corresponding to the Tx / Rx operation or R2R role indication information is set to 1 (or 0), it can indicate the Tx operation or the role of the sender.

[0331] The value of a bit (or a field including the bit) corresponding to the Tx / Rx operation or R2R role indication information included in the user (information) field for a Tx non-AP STA may always be set to 1 (or 0). And the value of a bit (or a field including a release bit) corresponding to the Tx / Rx operation or R2R role indication information included in the user (information) field for a Rx non-AP STA may always be set to 0 (or 1).

[0332] The BW / allocation information may include BW information for NDP transmission / reception (e.g., feedback). The BW / allocation information may be configured with the same two bits as the UL BW of the common information field of the trigger frame (i.e., a bit indicating the BW in which the NDP is transmitted) as described in the first embodiment. The BW in which the NDP is transmitted may indicate one of 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 80+80 MHz.

[0333] As yet another example, the BW / allocation information may be configured with 3 bits. In this case, the BW / allocation information may also indicate a BW of 320 MHz or more as the BW in which the NDP is transmitted.

[0334] As an example, the BW in which the NDP is transmitted as indicated by the BW / allocation information may be configured to be smaller than or equal to the UL BW in the common information field of the trigger frame.

[0335] As an example, the BW / allocation information on the user information field included in the trigger frame may include puncturing information. That is, the BW / allocation information may be configured with 5 bits to indicate the puncturing information. A non-AP STA can check the BW in which the NDP is transmitted by the UL BW subfield of the common information field of the trigger frame, and can check the information to be punctured in the BW by the BW / allocation information field.

[0336] The "GI+LTF size (or / and type)" information may be used to indicate information about the GI and LTF size used when transmitting the NDP. Specifically, since the non-AP STA transmits the NDP using the SU format, the GI and LTF size can be confirmed from the "GI+LTF size (or / and type)" information.

[0337] Here, the "GI+LTF size (or / and type)" information included in the user information field may be configured to be different from the "GI+LTF type" information transmitted in the common information field of the trigger frame.

[0338] As an example, the “GI+LTF size (or / and type)” information may be composed of two bits as shown in Table 3.

[0339] As yet another example of the present disclosure, when a trigger frame configured as an SBP / R2R sensing trigger (sub)variant is transmitted, the “GI+LTF size subfield” of the common information field of the trigger frame may be configured according to the above-mentioned configuration (e.g., a configuration according to Table 3).

[0340] Furthermore, the "GI+LTF size subfield" of the common information field of the trigger frame can indicate information on the GI and LTF type (or / and size) for NDP transmission using the SU format.

[0341] As an example, when the common information field of the trigger frame includes a “GI+LTF size subfield” configured as described above, the user information field of the trigger frame does not need to include a “GI+LTF size subfield”.

[0342] The NSS information may indicate the number of spatial streams allocated when transmitting the NDP. For example, the NSS information may be composed of 3 bits and may indicate any one of 1 to 8 as the number of spatial streams.

[0343] The measurement ID is information for indicating an R2R measurement and may be configured with ID information. The ID indicated by the measurement ID may be set as a setup ID determined during the R2R procedure setup or may be set as a sensing measurement setup ID.

[0344] 20, an AP can transmit a trigger frame including two user (information) fields to non-AP STAs (e.g., non-AP STA 1 and non-AP STA 2) performing / supporting R2R measurement. A non-AP STA (e.g., non-AP STA 1 and non-AP STA 2) performing / supporting R2R measurement can check the AID and Tx / Rx operation or R2R role indication information included in the corresponding user information field to check which operation it will perform (or what role it will play) during R2R measurement.

[0345] As described in the first embodiment, a non-AP STA that has learned of the execution of R2R measurement from a trigger frame transmitted by an AP can transmit and receive an NDP based on the information received from the trigger frame.

[0346] Subsequent procedures (e.g., a procedure for measuring a channel by NDP and reporting the measurement result) may be configured the same as the procedure described in the embodiment 1. When the measurement ID information is included in the trigger frame, an ID according to the measurement ID information may be included in the feedback request frame and the feedback report frame and transmitted / received.

[0347] Example 3-3

[0348] For R2R measurement, the AP may send an R2R request frame to a non-AP STA that performs / supports R2R measurement identified by the SBP procedure setup. That is, the R2R request frame may be sent to request the non-AP STA to perform an R2R request.

[0349] In the R2R measurement stage, TF (trigger frame) sounding may be performed, but is not limited thereto, and NDPA (NDP announcement) sounding may also be performed.

[0350] As shown in Figure 21, the AP can transmit an R2R request frame to non-AP STA 1 (i.e., a non-AP STA that supports R2R measurement) identified during the SBP procedure setup to perform R2R measurement. Non-AP STA 1 that receives the R2R request frame from the AP can transmit an R2R response frame to the AP that includes information on whether to perform R2R operation.

[0351] The RA field of the R2R request frame may be set to the ID of the non-AP STA that transmits the trigger frame to perform TF sounding in R2R measurement.

[0352] As an example, the R2R request frame may include BW information, puncturing information, R2R non-AP STA information, R2R measurement setup ID, and R2R measurement parameter information.

[0353] Here, the BW information means information on the BW for performing R2R measurement, that is, the BW information may indicate the BW for NDP transmission and reception.

[0354] The puncturing information may indicate information regarding a puncturing pattern within the BW, for example, the puncturing information may indicate the presence or absence of puncturing in units of 20 MHz or 40 MHz within the BW.

[0355] The R2R non-AP STA information may include information about a non-AP STA that performs R2R measurement (e.g., information about non-AP STA 2 in FIG. 21). Here, the information about a non-AP STA that performs R2R measurement may include AID information of the non-AP STA that performs R2R measurement (e.g., ID information of a non-AP STA that transmits an NDP for R2R measurement), etc.

[0356] The non-AP STA 1 that starts the R2R measurement can check information about other non-APs that perform the R2R measurement using the R2R non-AP STA information.

[0357] The R2R measurement setup ID may include identification information for the R2R measurement. The R2R measurement setup ID may be used when requesting R2R measurement feedback. The R2R measurement setup ID may be set as a sensing measurement setup ID or an SBP setup ID.

[0358] The R2R measurement parameter information may include information about sensing parameters for performing the R2R measurement. The sensing parameters for performing the R2R measurement may include NSS, LTF type and CP, feedback type and delayed feedback, etc.

[0359] Here, Nss may mean information on the number of spatial streams used when transmitting NDP. The LTF type and CP may mean configuration information of LTF symbols and CP size information used when transmitting NDP. The feedback type may include feedback type information for R2R measurement. The delayed feedback may include information on whether to support delayed feedback.

[0360] The R2R response frame may include response information to the R2R request frame. The response information may be transmitted by a status code.

[0361] As an example, if Non-AP STA 1 accepts the R2R response, the status code may be set to "SUCCESS." As an example, if Non-AP STA 1 rejects the R2R response, the status code may be set to "denied for R2R measurement."

[0362] As yet another example, if non-AP STA 1 accepts the R2R response but desires to change sensing parameters, the status code may be set to “preferred R2R measurement suggested.” When the status code is set to “preferred R2R measurement suggested,” the R2R response frame may include information regarding sensing parameters preferred by the non-AP STA.

[0363] A non-AP STA that has confirmed information regarding R2R measurement through an R2R request / response frame can transmit a trigger frame to other non-AP STAs that are performing R2R measurement (confirmed through the frame) to perform R2R measurement.

[0364] Here, the trigger frame is a frame for starting the R2R measurement, and may be defined as an R2R trigger frame (sub)variant.

[0365] The TA of the trigger frame may be set to the non-AP STA that transmits the trigger frame. Referring to Figure 21, the TA of the trigger frame may be set to the address of non-AP STA 1, and the RA may be set to the address of the non-AP STA (i.e., non-AP STA 2) that receives the trigger frame and transmits the NDP.

[0366] As an example, the user (information) field of the trigger frame may include AID information, BW / allocation information, "GI+LTF size (or / and type)" information, and NSS (number of spatial stream) information.

[0367] Here, the AID information may include ID information for a non-AP STA to which the NDP transmits for R2R measurement.

[0368] And, the BW / allocation information may include BW information for NDP transmission. The BW / allocation information may be configured with the same two bits as the UL BW of the common information field of the trigger frame (i.e., a bit indicating the BW in which the NDP is transmitted). The BW in which the NDP is transmitted may indicate one of 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 80+80 MHz.

[0369] As yet another example, the BW / allocation information may be configured with 3 bits. In this case, the BW / allocation information may also indicate a BW of 320 MHz or more as the BW in which the NDP is transmitted.

[0370] As an example, the BW in which the NDP is transmitted as indicated by the BW / allocation information may be configured to be smaller than or equal to the UL BW in the common information field of the trigger frame.

[0371] As an example, the BW / allocation information on the user information field included in the trigger frame may include puncturing information. That is, the BW / allocation information may be configured with 5 bits to indicate the puncturing information. A non-AP STA can check the BW in which the NDP is transmitted by the UL BW subfield of the common information field of the trigger frame, and can check the information to be punctured in the BW by the BW / allocation information field.

[0372] The "GI+LTF size (or / and type)" information may be used to indicate information about the GI and LTF size used when transmitting an NDP. Specifically, since a non-AP STA transmits an NDP using the SU format, the GI and LTF size can be confirmed from the "GI+LTF size (or / and type)" information.

[0373] Here, the "GI+LTF size (or / and type)" information included in the user information field may be configured to be different from the "GI+LTF type" information transmitted in the common information field of the trigger frame.

[0374] As an example, the "GI+LTF size (or / and type)" information may be composed of two bits as shown in Table 4 below.

[0375] [Table 4]

[0376] As yet another example of the present disclosure, when a trigger frame configured as an SBP / R2R sensing trigger (sub)variant is transmitted, the "GI+LTF size subfield" of the common information field of the trigger frame may be configured according to the above-mentioned configuration (e.g., a configuration according to Table 4). Then, the "GI+LTF size subfield" of the common information field of the trigger frame may indicate information on the GI and LTF type (or / and size) for NDP transmission using the SU format.

[0377] As an example, when the common information field of the trigger frame includes a “GI+LTF size subfield” configured as described above, the user information field of the trigger frame does not need to include a “GI+LTF size subfield.”

[0378] The NSS information may indicate the number of spatial streams allocated when transmitting the NDP. As an example, the NSS information may be composed of 3 bits and may indicate any one of 1 to 8 as the number of spatial streams.

[0379] 21, non-AP STA 2, which receives a trigger frame from non-AP STA 1, can use the trigger frame information to transmit an NDP to non-AP STA 1. Non-AP STA 1 can measure channel information between the two STAs using the NDP received from non-AP STA 2.

[0380] Non-AP STA 1 may receive a feedback request frame from the AP, and may transmit the measured R2R measurement result to the AP.

[0381] As shown in Fig. 21, each frame may be transmitted at an SIFS interval, but various IFS may be applied. As an example, an IFS (e.g., AIFS, DIFS, PIFS, etc.) with an interval larger than SIFS may be applied between the feedback request frame and the feedback report frame.

[0382] The above-described embodiments are combinations of the components and features of the present disclosure in a predetermined form. Each component or feature should be considered as optional unless otherwise expressly stated. Each component or feature may be implemented in a form not combined with other components or features. It is also possible to combine some components and / or features to configure the embodiments of the present disclosure. The order of operations described in the embodiments of the present disclosure may be changed. Some configurations or features of one embodiment may be included in another embodiment, or may be replaced with corresponding configurations 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 configure an embodiment, or may be included as a new claim by amendment after filing.

[0383] 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 a reasonable interpretation of the attached claims, and any modifications within the equivalent scope of the present disclosure are included in the scope of the present disclosure.

[0384] 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 the various embodiments, and non-transitory computer-readable media on which such software or instructions or the like can be stored and executed on a device or computer. Instructions available for programming a processing system to perform features described in the present disclosure may be stored on / 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 the present disclosure. The storage medium may include high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid-state memory devices, but is not limited thereto, and may include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory optionally includes one or more storage devices that are located remotely from the processor. The memory or alternatively the non-volatile memory devices in the memory include 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]

[0385] 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 STA (station) in a wireless LAN system, The first STA receives a sensing trigger frame from the second STA, the sensing trigger subtype field including information relating to whether the sensing trigger frame is an SR2SR (sensing responder to sensing to responder) sounding trigger frame, The SR2SR sounding stage includes the step of transmitting an SR2SR NDP (null data physical protocol data unit) to at least one STA based on the sensing trigger frame, or receiving the SR2SR NDP from at least one STA, The sensing trigger frame includes information relating to the role of the first STA in the SR2SR sounding stage.

2. The sensing trigger frame includes a single sender user information field and at least one of at least one receiver user information fields. The method according to claim 1, wherein the information relating to the role of the first STA is indicated via a Tx (transmission) / Rx (reception) subfield contained in the single sender user information field or the at least one receiver user information field.

3. The Tx / Rx subfield consists of 1 bit, The value of the Tx / Rx subfield included in the single sender user information field is set to 0. The method according to claim 2, wherein the value of the Tx / Rx subfield contained in at least one recipient user information field is set to 1.

4. The method according to claim 2, wherein the AID (association identity) of the first STA is included in the single sender user information field, based on the role of the first STA being an SR2SR sensing sender.

5. The sensing trigger frame, which includes at least one recipient user information field, is transmitted to the at least one STA. The method according to claim 4, wherein the at least one recipient user information field includes the AID of the at least one STA.

6. The method according to claim 2, wherein the single sender user information field includes at least one of the following: the number of spatial streams assigned to the first STA or information relating to the size of the LTF (long-training field).

7. The method according to claim 1, wherein an SR2SR field indicating information indicating support for SR2SR sounding is transmitted from the first STA to the second STA.

8. The method according to claim 4, wherein the sensing measurement by the SR2SR NDP is performed by the at least one STA, based on the fact that the SR2SR NDP is transmitted by the at least one STA with a bandwidth of 160 MHz or less.

9. The method according to claim 8, wherein a frame containing the sensing measurement result is transmitted from the at least one STA to the second STA based on the transmission of a frame from the second STA requesting the sensing measurement result performed by the SR2SR NDP to the at least one STA.

10. The method according to claim 1, wherein the value of the sensing trigger subtype field included in the trigger dependent common information subfield of the sensing trigger frame is set to 4.

11. The second STA is an SBP responder that receives an SBP request frame from an SBP (sensing by proxy) initiator, The method according to claim 1, wherein the SBP initiator is a non-AP (access point) STA, and the SBP responder is an AP.

12. The SBP request frame includes parameters related to the SBP procedure and sensing measurement, The method according to claim 11, wherein the SBP response frame transmitted by the SBP responder to the SBP initiator includes a status code for at least one of the parameters related to the SBP procedure or the sensing measurement.

13. The first STA (station), At least one transceiver and, The system comprises at least one processor connected to the at least one transceiver, The at least one processor is configured to receive a sensing trigger frame including a sensing trigger subtype field from the second STA via the at least one transceiver. The sensing trigger subtype field includes information related to whether the sensing trigger frame is an SR2SR (sensing responder to sensing to responder) sounding trigger frame. The at least one processor is further configured to, in the SR2SR sounding phase, transmit an SR2SR NDP (null data physical protocol data unit) to at least one STA via the at least one transceiver based on the sensing trigger frame, or receive the SR2SR NDP from the at least one STA via the at least one transceiver. The sensing trigger frame includes a first STA containing information related to the role of the first STA in the SR2SR sounding stage.

14. A second STA (station) in a wireless LAN system, At least one transceiver and, The system comprises at least one processor connected to the at least one transceiver, The aforementioned at least one processor is A sensing trigger frame including a sensing trigger subtype field is transmitted to a plurality of STAs, including a first STA, via at least one transceiver. In the SR2SR (sensing responder to sensing to responder) sounding phase, the measurement results for the SR2SR NDP (null data physical protocol data unit) transmitted based on the sensing trigger frame are received from at least one of the plurality of STAs via at least one transceiver. The sensing trigger frame includes a second STA containing information related to the role of the first STA in the SR2SR sounding stage.

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