Method and apparatus for performing sensing measurement in wireless LAN system

Abstract

A method and an apparatus operating in a wireless LAN system are disclosed. A method performed by a first STA in a wireless LAN system according to an embodiment disclosed herein may comprise the steps of: receiving, from a second STA, a sensing trigger frame including a trigger-related common information subfield; and receiving the NDP from the at least one STA or transmitting the NDP to the at least one STA based on the sensing trigger frame, in which the trigger-related common information sub-field includes a measurement session ID field and a sensing trigger sub-type field, and the sensing trigger sub-type field may include information indicating that a sub-type of the sensing trigger frame is SR2SR sounding.

Description

Technical Field

[0001] The present disclosure relates to communication operations in a wireless local area network (WLAN) system, and more particularly, to a method and apparatus for performing sensing measurements in a WLAN system. Background Art

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

[0003] In order to provide a more advanced wireless communication environment, improved technologies for extremely high throughput (EHT) are being discussed. For example, technologies for MIMO and multi-access point (AP) coordination that support increased bandwidth, efficient use of multiple frequency bands, and increased spatial streams are being studied, and specifically, various technologies are being studied to support low latency or real-time services. In addition, new technologies are being discussed to support ultra-high reliability (UHR), including improvements or extensions of EHT technologies. Summary of the invention

[0004] Technical issues

[0005] The technical problem of the present disclosure is to provide a method and an apparatus for performing sensing measurements in a wireless LAN system.

[0006] The technical problem of the present disclosure is to provide a method and an apparatus for performing sensing responder-to-sensing responder (SR2SR) sensing measurement in a wireless LAN system.

[0007] The technical objectives to be achieved by the present disclosure are not limited to the above-mentioned technical objectives, and those skilled in the art can clearly understand other technical objectives not described herein through the following description.

[0008] Technical Solution

[0009] According to one embodiment of the present disclosure, a method performed by a first station (STA) in a wireless LAN system may include: receiving a sensing trigger frame including a trigger-related common information subfield from a second STA; and based on the sensing trigger frame, receiving a null data physical protocol data unit (NDP) from at least one STA or sending the NDP to the at least one STA, and the trigger-related common information subfield may include a measurement session ID field and a sensing trigger subtype field, and the sensing trigger subtype field may include information indicating that the subtype of the sensing trigger frame is SR2SR (sensing responder to sensing responder) detection.

[0010] According to another embodiment of the present disclosure, a method performed by a second station (STA) in a wireless LAN system may include: sending a sensing trigger frame including a trigger-related public information subfield to at least one STA; sending a sensing report trigger frame requesting NDP-based measurement information to a first STA among the at least one STA; and receiving a sensing measurement report frame from the first STA, and the trigger-related public information subfield may include a measurement session ID field and a sensing trigger subtype field, and the sensing trigger subtype field may include information indicating that the subtype of the sensing trigger frame is SR2SR (sensing responder to sensing responder) detection.

[0011] Technical Effects

[0012] According to various embodiments of the present disclosure, a method and apparatus for performing sensing measurement in a wireless LAN system may be provided.

[0013] According to various embodiments of the present disclosure, a method and apparatus for performing SR2SR sensing measurement in a wireless LAN system may be provided.

[0014] According to various embodiments of the present disclosure, the accuracy of a sensing operation may be improved by performing a sensing measurement operation between sensing responders.

[0015] Effects achievable by the present disclosure are not limited to the above-described effects, and other effects not described herein may be clearly understood by those skilled in the relevant art through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are included as a part of the detailed description for understanding the present disclosure, provide embodiments of the present disclosure and describe technical features of the present disclosure together with the detailed description.

[0017] Figure 1 A configuration block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0018] Figure 2is a diagram illustrating an exemplary structure of a WLAN system to which the present disclosure can be applied.

[0019] Figure 3 It is a diagram for explaining a link establishment process to which the present disclosure can be applied.

[0020] Figure 4 This is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0021] Figure 5 It is a diagram for explaining a frame transmission operation based on CSMA / CA to which the present disclosure can be applied.

[0022] Figure 6 is a diagram for explaining an example of a frame structure used in a WLAN system to which the present disclosure can be applied.

[0023] Figure 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.

[0024] Figure 8 A diagram showing an exemplary format of a trigger frame to which the present disclosure may be applied.

[0025] Fig. 9 is a diagram for explaining an operation performed by a first STA according to an embodiment of the present disclosure.

[0026] Fig.10 is a diagram for explaining an operation performed by a second STA according to an embodiment of the present disclosure.

[0027] Fig.11 is a diagram for explaining the SR2SR detection phase according to an embodiment of the present disclosure.

[0028] Fig.12 is a diagram for explaining one or more parameters related to the SR2SR detection phase according to an embodiment of the present disclosure.

[0029] Fig.13 is a diagram for explaining the SR2SR detection phase according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed by the accompanying drawings is intended to describe exemplary embodiments of the present disclosure, rather than to represent the only embodiment in which the present disclosure can be implemented. The following detailed description includes specific details to provide a complete understanding of the present disclosure. However, those skilled in the relevant art know that the present disclosure can be implemented without these specific details.

[0031] In some cases, well-known structures and devices may be omitted, or may be shown in the form of a block diagram based on the core functions of each structure and device in order to prevent ambiguity of the concepts of the present disclosure.

[0032] In the present disclosure, when an element is referred to as being "connected", "combined" or "linked" to another element, it may include an indirect connection relationship between another element and a direct connection relationship. In addition, in the present disclosure, the term "comprising" or "having" specifies the presence of the mentioned features, steps, operations, components and / or elements, but does not exclude the presence or addition of one or more other features, stages, operations, components, elements and / or groups thereof.

[0033] In the present disclosure, terms such as "first", "second", etc. are only used to distinguish one element from another element and are not used to limit the elements, and unless otherwise specified, they do not limit the order or importance between elements, etc. Therefore, within the scope of the present disclosure, the first element in an embodiment may be referred to as the second element in another embodiment, and similarly, the second element in an embodiment may be referred to as the first element in another embodiment.

[0034] The terms used in this disclosure are intended to describe specific embodiments, rather than to limit 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 clearly indicates otherwise. The term "and / or" used in this disclosure may refer to one of the related enumerated items, or mean that it refers to and includes any and all possible combinations of two or more of them. In addition, unless otherwise stated, the " / " between words in this disclosure has the same meaning as "and / or".

[0035] Examples of the present disclosure can be applied to various wireless communication systems. For example, examples of the present disclosure can be applied to wireless LAN systems. For example, examples of the present disclosure can be applied to wireless LANs based on IEEE 802.11a / g / n / ac / ax standards. In addition, examples of the present disclosure can be applied to wireless LANs based on the newly proposed IEEE 802.11be (or EHT) standard. Examples of the present disclosure can be applied to wireless LANs based on the IEEE802.11be version 2 standard corresponding to the additional enhanced technology of the IEEE 802.11be version 1 standard. In addition, examples of the present disclosure can be applied to wireless LANs based on next-generation standards after IEEE 802.11be. In addition, examples of the present disclosure can be applied to cellular wireless communication systems. For example, it can be applied to cellular wireless communication systems based on long-term evolution (LTE) technology and 5G new radio (NR) technology based on the third generation partnership project (3GPP) standard.

[0036] Hereinafter, technical features of examples to which the present disclosure can be applied will be described.

[0037] Figure 1 A block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0038] Figure 1 The first device 100 and the second device 200 illustrated in the figure may be replaced with various terms such as terminal, wireless device, wireless transmit / receive unit (WTRU), user equipment (UE), mobile station (MS), user terminal (UT), mobile subscriber station (MSS), mobile subscriber unit (MSU), subscriber station (SS), advanced mobile station (AMS), wireless terminal (WT) or simple user, etc. In addition, the first device 100 and the second device 200 include an access point (AP), a base station (BS), a fixed station, a node B, a base transceiver system (BTS), a network. It may be replaced with various terms such as an artificial intelligence (AI) system, a roadside unit (RSU), a repeater, a router, a relay and a gateway.

[0039] Figure 1 The devices 100 and 200 illustrated in the example may be referred to as stations (STAs). Figure 1 The devices 100 and 200 illustrated in the figure may be referred to by various terms such as a transmitting device, a receiving device, a transmitting STA, and a receiving STA. For example, STAs 110 and 200 may perform an access point (AP) role or a non-AP role. That is, in the present disclosure, STAs 110 and 200 may perform the functions of an AP and / or a non-AP. When STAs 110 and 200 perform AP functions, they may be simply referred to as APs, and when STAs 110 and 200 perform non-AP functions, they may be simply referred to as STAs. In addition, in the present disclosure, an AP may also be indicated as an AP STA.

[0040] Reference Figure 1 , the first device 100 and the second device 200 can send and receive radio signals through various wireless LAN technologies (e.g., IEEE802.11 series). The first device 100 and the second device 200 may include interfaces for a media access control (MAC) layer and a physical layer (PHY) that conform to the IEEE802.11 standard.

[0041] In addition, in addition to the wireless LAN technology, 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.) technologies. In addition, the device of the present disclosure may be implemented in various devices such as mobile phones, vehicles, personal computers, augmented reality (AR) devices, and virtual reality (VR) devices. In addition, the STA of the present specification may support various communication services such as voice calls, video calls, data communications, autonomous driving, machine type communications (MTC), machine to machine (M2M), device to device (D2D), IoT (Internet of Things), etc.

[0042] The first device 100 may include 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 control the memory 104 and / or the transceiver 106, and may be configured to implement the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in the present disclosure. For example, the processor 102 may send a wireless signal including the first information / signal through the transceiver 106 after generating the first information / signal by processing the information in the memory 104. In addition, the processor 102 may receive a wireless signal including the second information / signal through the transceiver 106, and then store the information obtained by the signal processing of the second information / signal in the memory 104. The memory 104 may be connected 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 codes including instructions for executing all or part of the processing controlled by the processor 102 or for executing the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included 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 connected to the processor 102 and may send and / or receive wireless signals through one or more antennas 108. The transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used in conjunction with an RF (radio frequency) unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0043] The second device 200 may include one or more processors 202 and 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 control the memory 204 and / or the transceiver 206, and may be configured to implement the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts included in the present disclosure. For example, the processor 202 may generate third information / signals by processing the information in the memory 204, and then send a wireless signal including the third information / signal through the transceiver 206. In addition, the processor 202 may receive a wireless signal including fourth information / signals through the transceiver 206, and then store information obtained by signal processing of the fourth information / signal in the memory 204. The memory 204 may be connected 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 codes including instructions for executing all or part of the processing controlled by the processor 202 or for executing the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts included 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 connected to the processor 202 and may send and / or receive wireless signals through one or more antennas 208. The transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used in conjunction with an RF unit. In the present disclosure, a device may refer to a communication modem / circuit / chip.

[0044] In the following, the hardware elements of the apparatus 100, 200 will be described in more detail. Without limitation thereto, one or more protocol layers may be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 may implement one or more layers (e.g., functional layers such as PHY, MAC). One or more processors 102, 202 may generate one or more PDUs (protocol data units) and / or one or more SDUs (service data units) according to the description, function, process, suggestion, method, and / or operation flow chart disclosed in the present disclosure. One or more processors 102, 202 may generate messages, control information, data, or information according to the description, function, process, suggestion, method, and / or operation flow chart disclosed in the present disclosure. One or more processors 102, 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, processes, suggestions, and / or methods disclosed in the present disclosure to provide them to one or more transceivers 106, 206. One or more processors 102, 202 may receive a signal (e.g., a baseband signal) from one or more transceivers 106, 206 according to the descriptions, functions, processes, suggestions, methods, and / or operational flow charts included in the present disclosure and obtain a PDU, SDU, message, control information, data, or information.

[0045] One or more processors 102, 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102, 202 may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) may be included in one or more processors 102, 202. The descriptions, functions, processes, suggestions, methods, and / or operational flow charts included in the present disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, processes, functions, and the like. Firmware or software configured to execute the descriptions, functions, processes, suggestions, methods, and / or operational flow charts included in the present disclosure may be included in one or more processors 102, 202, or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions, functions, processes, suggestions, methods and / or operational flow charts included in the present disclosure may be implemented using firmware or software in the form of codes, instructions and / or instruction sets.

[0046] One or more memories 104, 204 may be connected to one or more processors 102, 202 and may store data, signals, messages, information, programs, codes, instructions, and / or commands in various forms. One or more memories 104, 204 may be configured with ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer-readable storage media, and / or combinations thereof. One or more memories 104, 204 may be located inside and / or outside one or more processors 102, 202. In addition, one or more memories 104, 204 may be connected to one or more processors 102, 202 via various technologies such as wired or wireless connections.

[0047] One or more transceivers 106, 206 may send user data, control information, wireless signals / channels, etc. mentioned in the method and / or operation flow chart of the present disclosure to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc. mentioned in the description, function, process, suggestion, method and / or operation flow chart, etc. included in the present disclosure from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and may send and receive wireless signals. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to send user data, control information or wireless signals to one or more other devices. In addition, one or more processors 102, 202 may control one or more transceivers 106, 206 to receive user data, control information or wireless signals from one or more other devices. In addition, one or more transceivers 106, 206 may be connected to one or more antennas 108, 208, and one or more transceivers 106, 206 may be configured to send and receive user data, control information, wireless signals / channels, etc. mentioned in the description, functions, processes, suggestions, methods and / or operation flow charts, etc. included in the present disclosure through one or more antennas 108, 208. In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106, 206 may convert received wireless signals / channels, etc. from RF band signals into baseband signals to process received user data, control information, wireless signals / channels, etc. by using one or more processors 102, 202. One or more transceivers 106, 206 may convert user data, control information, wireless signals / channels, etc. processed by using one or more processors 102, 202 from baseband signals into RF band signals. Thus, one or more of the transceivers 106 , 206 may include (analog) oscillators and / or filters.

[0048] For example, one of the STAs 100 and 200 may perform the expected operation of an AP, and the other of the STAs 100 and 200 may perform the expected operation of a non-AP STA. Figure 1 The transceivers 106 and 206 of the present invention may perform transmission and reception operations of signals (e.g., packets or physical layer protocol data units (PPDUs) compliant with IEEE 802.11a / b / g / n / ac / ax / be / bn). In addition, in the present disclosure, operations of various STAs generating transmission / reception signals or performing data processing or calculations on transmission / reception signals in advance may be performed by Figure 1The processors 102 and 202 are executed. For example, examples of operations of generating a transmission / reception signal or performing data processing or calculation for the transmission / reception signal in advance may include: 1) determining / obtaining / configuring / calculating / decoding / encoding bit information of fields (signal (SIG), short training field (STF), long training field (LTF), data, etc.) included in the PPDU; 2) determining / configuring / obtaining time resources or frequency resources (e.g., subcarrier resources) for fields (SIG, STF, LTF, data, etc.) included in the PPDU; 3) determining / configuring / obtaining a specific sequence (e.g., pilot sequence, STF / LTF sequence, additional sequence applied to SIG) for fields (SIG, STF, LTF, data, etc.) included in the PPDU action; 4) power control operations and / or power saving operations applied to STAs; 5) operations related to ACK signal determination / obtaining / configuring / calculating / decoding / encoding, etc. In addition, in the following example, various information used by various STAs to determine / acquire / configure / calculate / decode / encode transmission signals and reception signals (e.g., information related to fields / subfields / control fields / parameters / power, etc.) may be stored in Figure 1 in the memories 104 and 204.

[0049] Hereinafter, a downlink (DL) may mean a link for communication from an AP STA to a non-AP STA, and a DL PPDU / packet / signal may be transmitted and received through the DL. In DL communication, a transmitter may be a part of an AP STA, and a receiver may be a part of a non-AP STA. An uplink (UL) may mean a link for communication from a non-AP STA to an AP STA, and a UL PPDU / packet / signal may be transmitted and received through the UL. In UL communication, a transmitter may be a part of a non-AP STA, and a receiver may be a part of an AP STA.

[0050] Figure 2 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0051] The structure of the wireless LAN system may be composed of a plurality of components. A wireless LAN supporting STA mobility transparent to an upper layer may be provided through the interaction of the plurality of components. A basic service set (BSS) corresponds to a basic building block of a wireless LAN. Figure 2 It is exemplarily shown that two BSSs (BSS1 and BSS2) exist, and two STAs (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2) are included as members of each BSS. Figure 2The ellipse representing the BSS in the figure can also be understood as representing the coverage area in which the STAs included in the corresponding BSS maintain communication. This area can be called a basic service area (BSA). When a STA moves outside the BSA, it cannot communicate directly with other STAs in the BSA.

[0052] If you don't consider Figure 2 , the most basic BSS type in the wireless LAN is an independent BSS (IBSS), if the DS is shown in FIG. 1 . For example, an IBSS may have a minimum form containing only two STAs. For example, assuming that other components are omitted, a BSS1 containing only STA1 and STA2 or a BSS2 containing only STA3 and STA4 may correspond to representative examples of IBSSs, respectively. This configuration is possible when STAs can communicate directly without an AP. In addition, in this type of wireless LAN, it is not pre-configured but can be configured when a LAN is needed, and this may be referred to as an ad-hoc network. Since the IBSS does not include an AP, there is no centralized management entity. That is, in the IBSS, STAs are managed in a distributed manner. In the IBSS, all STAs may be composed of mobile STAs, and access to the distributed system (DS) is not allowed, thereby forming a self-contained network.

[0053] The membership of a STA in a BSS can be changed dynamically by turning the STA on or off, entering or exiting a BSS region, etc. In order to become a member of a BSS, a STA can join the BSS using a synchronization process. In order to access all services of the BSS infrastructure, a STA should associate with the BSS. This association can be established dynamically and can include the use of a distributed system service (DSS).

[0054] The direct STA-to-STA distance in a wireless LAN may be limited by PHY performance. In some cases, this distance limitation may be sufficient, but in some cases, communication between STAs at longer distances may be required. A distributed system (DS) can be configured to support extended coverage.

[0055] DS refers to the structure of BSS interconnection. Specifically, Figure 2As shown, the BSS can exist as an extended form of a network composed of multiple BSSs. DS is a logical concept and can be specified by the characteristics of the distributed system medium (DSM). At this point, the wireless medium (WM) and the DSM can be logically separated. Each logical medium is used for different purposes and is used by different components. These media are not limited to being the same, nor are they limited to being different. In this way, the flexibility of the wireless LAN structure (DS structure or other network structure) can be interpreted as multiple media being logically different. That is, the wireless LAN structure can be implemented in various ways, and the corresponding wireless LAN structure can be independently specified by the physical characteristics of each implementation.

[0056] DS can support mobile devices by providing seamless integration of multiple BSSs and providing logical services necessary to address the address leading to the destination. In addition, DS can also include a component called a portal, which is used as a bridge for connection between wireless LAN and other networks (e.g., IEEE 802.X).

[0057] The AP enables access to the DS through the WM for associated non-AP STAs and means an entity that also has STA functionality. Data movement between the BSS and the DS can be performed through the AP. For example, Figure 2 STA2 and STA3 shown in the figure have the function of STA and provide the function of allowing the associated non-AP STA (STA1 and STA4) to access the DS. In addition, since all APs basically correspond to STAs, all APs are addressable entities. The address used by the AP to communicate on the WM is not necessarily the same as the address used by the AP to communicate on the DSM. A BSS composed of an AP and one or more STAs may be referred to as an infrastructure BSS.

[0058] Data sent from one of the STAs associated with the AP to the STA address of the corresponding AP can always be received at the uncontrolled port and can be processed by the IEEE 802.1X port access entity. In addition, when the controlled port is authenticated, the transmitted data (or frame) can be delivered to the DS.

[0059] In addition to the above-mentioned structure of the DS, an extended service set (ESS) may also be configured to provide wide coverage.

[0060] ESS means a network with arbitrary size and complexity consisting of DS and BSS. ESS may correspond to a set of BSSs connected to one DS. However, ESS does not include DS. The ESS network is characterized by being regarded as an IBSS in the logical link control (LLC) layer. The STAs included in the ESS can communicate with each other, and the mobile STA can move from one BSS to another (within the same ESS) transparently for LLC. The APs included in one ESS may have the same service set identifier (SSID). SSID is distinguished from BSSID, which is an identifier of BSS.

[0061] The wireless LAN system does not assume anything about the relative physical location of the BSS, and all of the following forms are possible. The BSS may partially overlap, which is a form commonly used to provide continuous coverage. In addition, the BSS may not be physically connected, and logically, there is no limit on the distance between the BSS. In addition, the BSS may be physically located in the same location, which can be used to provide redundancy. In addition, one (or more than one) IBSS or ESS network may physically exist in the same space as one (or more than one) ESS network. When an ad hoc network operates in a location where an 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, this may correspond to the form of an ESS network, etc.

[0062] Figure 3 is a diagram for explaining a link establishment process to which the present disclosure can be applied.

[0063] In order for a STA to establish a link with respect to a network and send / receive data, it first discovers the network, performs authentication, establishes association, and needs to perform authentication processing for security. The link establishment processing may also be referred to as a session initiation processing or a session establishment processing. In addition, the discovery, authentication, association, and security establishment processing of the link establishment processing may be collectively referred to as an association processing.

[0064] 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, it needs to find a network that it can participate in. The STA should identify compatible networks before participating in a wireless network, and the process of identifying networks present in a specific area is called scanning.

[0065] Scanning schemes include active scanning and passive scanning. Figure 3The network discovery operation including active scanning processing is exemplarily illustrated. In active scanning, the STA performing the scan sends a probe request frame to discover which APs exist around it while the channel moves and waits for a response thereto. The responder sends a probe response frame as a response to the probe request frame to the STA that has sent the probe request frame. Here, the responder may be the STA that last sent a beacon frame in the BSS of the channel being scanned. In the BSS, since the AP sends a beacon frame, the AP becomes the responder, and in the IBSS, the STAs in the IBSS rotate to send beacon frames, so the responder is not constant. For example, a STA that sends a probe request frame on channel 1 and receives a probe response frame on channel 1 may store the BSS-related information included in the received probe response frame, and may move to the next channel (e.g., channel 2), and perform scanning in the same manner (i.e., sending and receiving probe requests / responses on channel 2).

[0066] Although not in Figure 3 , but the scanning operation can be performed in a passive scanning manner. In passive scanning, the STA performing the scan waits for a beacon frame while the channel moves. The beacon frame is one of the management frames defined in IEEE 802.11, and is periodically sent to notify the existence of a wireless network and allow the STA performing the scan to find the wireless network and participate in the wireless network. In the BSS, the AP is used to periodically send beacon frames, and in the IBSS, the STAs within the IBSS rotate to send beacon frames. When the STA performing the scan receives the beacon frame, the STA stores the information of the BSS included in the beacon frame, and records the beacon frame information in each channel while moving to another channel. The STA receiving the beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform scanning in the next channel in the same manner. Comparing active scanning with passive scanning, the advantage of active scanning is that it has less delay and less power consumption than passive scanning.

[0067] After the STA discovers the network, an authentication process may be performed at step S320. In order to clearly distinguish from the security establishment operation of step S340 to be described later, this authentication process may be referred to as a first authentication process.

[0068] The authentication process includes the following process: the STA sends an authentication request frame to the AP, and in response thereto, the AP sends an authentication response frame to the STA. The authentication frame for authentication request / response corresponds to a management frame.

[0069] The authentication frame includes an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a robust security network (RSN), a limited cycle group, etc. This corresponds to some examples of information that can be included in the authentication request / response frame, and can be replaced with other information, or additional information can also be included.

[0070] The STA may send an authentication request frame to the AP. The AP may determine whether to allow authentication of the corresponding STA based on the information included in the received authentication request frame. The AP may provide the result of the authentication process to the STA via an authentication response frame.

[0071] After the STA is successfully authenticated, an association process may be performed at step S330. The association process includes the following processes: the STA sends an association request frame to the AP, and in response, the AP sends an association response frame to the STA.

[0072] For example, the association request frame may include information related to various capabilities, a beacon listening interval, a service set identifier (SSID), supported rates, supported channels, RSN, a mobile domain, supported operation categories, a traffic indication map broadcast request (TIM broadcast request), interworking service capabilities, etc. For example, the association response frame may include information related to 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 ratio indicator (RSNI), a mobile domain, a timeout interval (e.g., an association recovery time), an overlapping BSS scan parameter, a TIM broadcast response, a quality of service (QoS) map, etc. This corresponds to some examples of information that may be included in an association request / response frame, and may be replaced with other information, or may also include additional information.

[0073] After the STA successfully associates with the network, a security establishment process may be performed at step S340. The security establishment process at step S340 may be referred to as an authentication process through a robust security network association (RSNA) request / response, the authentication process at step S320 may be referred to as a first authentication process, and the security establishment process at step S340 may also be referred to simply as an authentication process.

[0074] The security establishment process of step S340 may include, for example, a process of establishing a private key through an Extensible Authentication Protocol over LAN (EAPOL) frame using a four-way handshake. In addition, the security establishment process may be performed according to a security scheme not defined in the IEEE 802.11 standard.

[0075] Figure 4 It is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0076] In a wireless LAN system, the basic access mechanism of the medium access control (MAC) is a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism. The CSMA / CA mechanism is also known as 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, before starting to send, the AP and / or STA may perform a clear channel assessment (CCA) of sensing the radio channel or medium during a predetermined time interval (e.g., DCF interframe space (DIFS)). As a result of the sensing, if it is determined that the medium is in an idle state, frame transmission is started through the corresponding medium. On the other hand, if it is detected that the medium is occupied or busy, the corresponding AP and / or STA does not start its own transmission, and a delay period (e.g., a random backoff period) for medium access may be set and frame transmission may be attempted after waiting. By applying a random backoff period, since multiple STAs are expected to attempt frame transmission after waiting for different time periods, conflicts can be minimized.

[0077] In addition, the IEEE 802.11 MAC protocol provides a hybrid coordination function (HCF). HCF is based on DCF and point coordination function (PCF). PCF is a synchronous access method based on polling, and refers to a method in which all receiving APs and / or STAs periodically poll to receive data frames. In addition, HCF has enhanced distributed channel access (EDCA) and HCF controlled channel access (HCCA). EDCA is a contention-based access method that provides data frames to multiple users in a direction, and HCCA uses a non-contention-based channel access method that utilizes a polling mechanism. In addition, HCF includes a medium access mechanism for improving the QoS (quality of service) of a wireless LAN, and QoS data can be sent during a contention period (CP) and a contention-free period (CFP).

[0078] Reference Figure 4, the operation based on the random backoff period will be described. When the occupied / busy medium becomes idle, multiple STAs may attempt to send data (or frames). As a method of minimizing conflicts, each of the STAs may select a random backoff count respectively and attempt to send after waiting for the corresponding time slot time. The random backoff count has a pseudo-random integer value and may be determined as one of the values ​​ranging from 0 to CW. Here, CW is a contention window parameter value. The CW parameter is assigned CWmin as an initial value, but may take a value twice as large in the event of a transmission failure (e.g., when an ACK for a transmitted frame is not received). When the CW parameter value reaches CWmax, data transmission may be attempted while maintaining the CWmax value until data transmission is successful, and when data transmission is successful, the CWmin value is reset. The values ​​of CW, CWmin, and CWmax are preferably set to 2n-1 (n=0, 1, 2, ...).

[0079] When the random backoff process starts, the STA continuously monitors the medium in the backoff slot countdown according to the determined backoff count value. When the medium is monitored for occupancy, it stops the countdown and waits, and restarts the remaining part of the countdown when the medium becomes idle.

[0080] exist Figure 4 In the example of , when the packet to be sent arrives at the MAC of STA 3, STA3 can send the frame immediately after confirming that the medium has been idle for up to DIFS. The remaining STAs monitor and wait for the medium to be occupied / busy. At the same time, the data to be sent can also occur in each of STA1, STA2 and STA5, and when the medium is monitored as idle, each STA waits for up to DIFS, and then the countdown of the backoff slot can be performed according to the random backoff count value selected by each STA. Assume that STA2 selects the minimum backoff count value and STA1 selects the maximum backoff count value. That is, the example illustrates the case where the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1 when STA2 completes the backoff count and starts frame transmission. STA1 and STA5 temporarily stop the countdown and wait when STA2 occupies the medium. When STA2's occupation ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and restart the stopped backoff count. That is, frame transmission can start after counting down the remaining backoff slot for the remaining backoff time. Since the remaining backoff time of STA5 is shorter than that of STA1, STA5 starts frame transmission. The data to be transmitted may also occur in STA4 while STA2 occupies the medium. From the perspective of STA4, when the medium becomes idle, STA4 may wait for DIFS, and then may perform a countdown according to a random backoff count value selected by STA4, and start transmitting frames. Figure 4The example shows a case where the remaining backoff time of STA5 accidentally collides with the random backoff count value of STA4. In this case, a collision may occur between STA4 and STA5. When a collision occurs, neither STA4 nor STA5 receives an ACK, so data transmission fails. In this case, STA4 and STA5 can double the CW value, select a random backoff count value, and perform a countdown. While the medium is occupied due to the transmission of STA4 and STA5, STA1 waits, and when the medium becomes idle, STA1 waits DIFS, and then starts frame transmission after the remaining backoff time has passed.

[0081] As in Figure 4 In the example of , a data frame is a frame for sending data forwarded to a higher layer, and may be sent after a backoff performed after DIFS has passed since the medium became idle. In addition, a management frame is a frame for exchanging management information that is not forwarded to a higher layer, and is sent after a backoff is performed after an IFS such as DIFS or a point coordination function IFS (PIFS). As subtype frames of the management frame, there are beacons, association requests / responses, reassociation requests / responses, probe requests / responses, authentication requests / responses, and the like. A control frame is a frame for controlling access to a medium. As subtype frames of the control frame, there are request to send (RTS), clear to send (CTS), acknowledgement (ACK), power save poll (PS-Poll), block ACK (BlockAck), block ACK request (BlockACKReq), empty data packet announcement (NDP announcement), and trigger, and the like. If the control frame is not a response frame of the previous frame, it is sent after performing a backoff after DIFS has passed, and if it is a response frame of the previous frame, it is sent without performing a backoff after a short IFS (SIFS) has passed. The type and subtype of the frame can be identified by the type field and subtype field in the frame control (FC) field.

[0082] Quality of Service (QoS) STA can perform a backoff performed after arbitration IFS (AIFS) (i.e., AIFS (where i is a value determined by AC)) for the access category (AC) to which the frame belongs, and then can send the frame. Here, the frame that can use AIFS may be a data frame, a management frame, or a control frame instead of a response frame.

[0083] Figure 5 is a diagram for explaining a frame transmission operation based on CSMA / CA to which the present disclosure can be applied.

[0084] As described above, in addition to the physical carrier sensing in which the STA directly senses the medium, the CSMA / CA mechanism also includes virtual carrier sensing. Virtual carrier sensing is intended to compensate for problems such as hidden node problems that may occur in medium access. For virtual carrier sensing, the MAC of the STA can use a network allocation vector (NAV). NAV is a value that indicates to other STAs the remaining time until the medium is available for use by the STA that is currently using or has the right to use the medium. Therefore, the value set to NAV corresponds to the period during which the STA sending the frame plans to use the medium, and during the corresponding period, the STA receiving the NAV value is prohibited from accessing the medium. For example, the NAV can be configured based on the value of the "Duration" field of the MAC header of the frame.

[0085] exist Figure 5 In the example of FIG. 1 , it is assumed that STA1 intends to send data to STA2, and STA3 is in a position to be able to eavesdrop on some or all frames sent and received between STA1 and STA2.

[0086] In order to reduce the possibility of transmission conflicts among multiple STAs in the CSMA / CA-based frame transmission operation, a mechanism using RTS / CTS frames can be applied. Figure 5 In the example of , when STA1's transmission is being performed, as a result of STA3's carrier sensing, it can be determined that the medium is in an idle state. That is, STA1 may correspond to a hidden node with respect to STA3. Alternatively, in Figure 5 In the example of , it can be determined that the carrier sensing result medium of STA3 is in an idle state while the transmission of STA2 is being performed. That is, STA2 may correspond to a hidden node with respect to STA3. By exchanging RTS / CTS frames before performing data transmission and reception between STA1 and STA2, STAs outside the transmission range of one of STA1 or STA2 or STAs outside the carrier sensing range of the transmission from STA1 or STA3 may not attempt to occupy the channel during data transmission and reception between STA1 and STA2.

[0087] Specifically, STA1 can determine whether the channel is being used by carrier sensing. In terms of physical carrier sensing, STA1 can determine the channel occupancy idle state based on the energy level or signal correlation detected in the channel. In addition, in terms of virtual carrier sensing, STA1 can use the network allocation vector (NAV) timer to determine the channel occupancy state.

[0088] When the channel is in an idle state during DIFS, STA1 may send an RTS frame to STA2 after performing backoff. When STA2 receives the RTS frame, STA2 may send a CTS frame to STA1 as a response to the RTS frame after SIFS.

[0089] If STA3 cannot eavesdrop on the CTS frame from STA2 but can eavesdrop on the RTS frame from STA1, STA3 can set the NAV timer for the frame transmission period (e.g., SIFS+CTS frame+SIFS+data frame+SIFS+ACK frame) that is continuously transmitted thereafter using the duration information included in the RTS frame. Alternatively, if STA3 can eavesdrop on the CTS frame from STA2, STA3 can set the NAV timer for the frame transmission period (e.g., SIFS+data frame+SIFS+ACK frame) that is continuously transmitted thereafter using the duration information included in the CTS frame even though STA3 cannot eavesdrop on the RTS frame from STA1. That is, if STA3 can eavesdrop on one or more of the RTS frame or the CTS frame from one or more of STA1 or STA2, STA3 can set the NAV accordingly. When STA3 receives a new frame before the NAV timer expires, STA3 can update the NAV timer using the duration information included in the new frame. STA3 does not attempt channel access until the NAV timer expires.

[0090] When STA1 receives a CTS frame from STA2, STA1 may send a data frame to STA2 after SIFS, starting from the time point when reception of the CTS frame is completed. When STA2 successfully receives the data frame, STA2 may send an ACK frame to STA1 after SIFS as a response to the data frame. When the NAV timer expires, STA3 may determine whether the channel is being used by carrier sensing. When STA3 determines that the channel is not being used by other terminals during the DIFS period after the NAV timer expires, STA3 may attempt channel access after the contention window (CW) according to the random backoff has passed.

[0091] Figure 6 is a diagram for explaining an example of a frame structure used in a WLAN system to which the present disclosure can be applied.

[0092] With the help of instructions or primitives (meaning a set of instructions or parameters) from the MAC layer, the PHY layer can prepare a MAC PDU (MPDU) to be transmitted. For example, when a command requesting the PHY layer to start transmitting is received from the MAC layer, the PHY layer switches to a transmission mode, and configures information (e.g., data) provided from the MAC layer in the form of a frame and transmits it. In addition, when the PHY layer detects a valid preamble of a received frame, the PHY layer monitors the header of the preamble and transmits a command notifying the start of reception of the PHY layer to the MAC layer.

[0093] In this manner, information transmission / reception in the wireless LAN system is performed in the form of a frame, and for this purpose, a PHY layer protocol data unit (PPDU) format is defined.

[0094] The basic PPDU may include a short training field (STF), a long training field (LTF), a signal (SIG) field, and a data (Data) field. The most basic PPDU format (e.g., Figure 7 The non-HT (high throughput) shown in the figure may consist of only the legacy-STF (L-STF), the legacy-LTF (L-LTF), the legacy-SIG (L-SIG) field and the data field. In addition, depending on the type of PPDU format (e.g., HT mixed format PPDU, HT greenfield format PPDU, VHT (very high throughput) PPDU, etc.), additional (or different types of) RL-SIG, U-SIG, non-legacy SIG field, non-legacy STF, non-legacy LTF (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)) and the like may be included between the L-SIG field and the data field.

[0095] STF is a signal used for signal detection, automatic gain control (AGC), diversity selection, precise time synchronization, etc., and LTF is a signal used for channel estimation and frequency error estimation. STF and LTF can be called signals for synchronization and channel estimation of the OFDM physical layer.

[0096] The SIG field may include various information related to the transmission and reception of the PPDU. For example, the L-SIG field consists of 24 bits, and 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. The RATE field may include information about the modulation and coding rate of the data. For example, the 12-bit length field may include information about the length or duration of the PPDU. For example, the value of the 12-bit length field may be determined based on the type of the PPDU. For example, for non-HT, HT, VHT, or EHT PPDUs, the value of the length field may be determined as a multiple of 3. For example, for HEPPDUs, the value of the length field may be determined as a multiple of 3+1 or a multiple of 3+2.

[0097] The data field may include a service (SERVICE) field, a physical layer service data unit (PSDU) and a PPDU tail bit, and may also include padding bits if necessary. Some bits of the service field may be used for synchronization of the descrambler at the receiving end. The PSDU corresponds to the MAC PDU defined in the MAC layer and may include data generated / used in the upper layer. The PPDU tail bit may be used to return the encoder to the 0 state. The padding bit may be used to adjust the length of the data field in predetermined units.

[0098] MAC PDU is defined according to 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 may consist of a MAC PDU and be transmitted / received through a PSDU of a data portion of a PPDU format.

[0099] 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 corresponding frame, etc. For details of the sequence control, QoS control, and HT control subfields of the MAC header, refer to the IEEE 802.11 standard document.

[0100] The null data PPDU (NDP) format refers to a PPDU format that does not include a data field. In other words, NDP refers to a frame format that includes a PPDU preamble (i.e., L-STF, L-LTF, L-SIG fields and additional non-legacy SIG, non-legacy STF, non-legacy LTF (if present)) of a general PPDU format and does not include the remaining part (i.e., the data field).

[0101] Figure 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.

[0102] In standards such as IEEE 802.11a / g / n / ac / ax, various types of PPDUs have been used. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and data fields. The basic PPDU format may also be referred to as a non-HT PPDU format (such as Figure 7 (as shown in (a)).

[0103] Compared to the basic PPDU format, the HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT fields. Figure 7The HT PPDU format shown in (b) may be referred to as an HT mixed format. In addition, an HT greenfield format PPDU may be defined, and this corresponds to a format consisting of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs, and a data field, excluding L-STF, L-LTF, and L-SIG (not shown).

[0104] Compared to the basic PPDU format, an example of the VHT PPDU format (IEEE 802.11ac) additionally includes VHTSIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields (eg, Figure 7 (as shown in (c)).

[0105] Compared to the basic PPDU format, an example of the HE PPDU format (IEEE 802.11ax) additionally includes a repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF, a packet extension (PE) field (such as Figure 7 (d) of the HE PPDU format). Some fields may be excluded or their lengths may vary according to the detailed example of the HE PPDU format. For example, the HE-SIG-B field is included in the HE PPDU format for multi-user (MU), and the HE-SIG-B is not included in the HE PPDU format for single user (SU). In addition, the HE trigger-based (TB) PPDU format does not include the HE-SIG-B, and the length of the HE-STF field may vary to 8μs. The extended range (HE ER) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may vary to 16μs. For example, the RL-SIG may be configured to be the same as the L-SIG. Based on the presence of the RL-SIG, the receiving STA may know that the received PPDU is a HE PPDU or an EHT PPDU, which will be described later.

[0106] The EHT PPDU format may include Figure 7 (e) EHT MU (multi-user) and Figure 7 The EHT TB (trigger-based) PPDU in (f) of FIG. The EHT PPDU format is similar to the HE PPDU format in that it includes the RL-SIG following the L-SIG, but may include the U (Universal)-SIG, the EHT-SIG, the EHT-STF, and the EHT-LTF following the RL-SIG.

[0107] Figure 7The EHT MU PPDU in (e) corresponds to a PPDU carrying one or more data (or PSDU) for one or more users. That is, the EHT MU PPDU can be used for both SU transmission and MU transmission. For example, the EHT MU PPDU can correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0108] Compared with EHT MU PPDU, Figure 7 The EHT TB PPDU in (f) omits the EHT-SIG. A STA that receives a trigger for UL MU transmission (eg, a trigger frame or a triggered response schedule (TRS)) may perform UL transmission based on the EHT TB PPDU format.

[0109] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal Signal), EHT-SIG fields may be coded and modulated so that even legacy STAs may attempt to demodulate and decode, and may be mapped based on a determined subcarrier frequency interval (e.g., 312.5kHz). These may be referred to as pre-EHT modulation fields. Next, the EHT-STF, EHT-LTF, data, PE fields may be coded and modulated so that they may be demodulated and decoded by a STA that successfully decodes a non-legacy SIG (e.g., U-SIG and / or EHT-SIG) and obtains the information included in the field, and may be mapped based on a determined subcarrier frequency interval (e.g., 78.125kHz). These may be referred to as EHT modulation fields.

[0110] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields may be referred to as pre-HE modulation fields, and the HE-STF, HE-LTF, data, and PE fields may be referred to as HE modulation fields. In addition, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields may be referred to as non-VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and data fields may be referred to as VHT modulation fields.

[0111] Included in Figure 7The U-SIG in the EHT PPDU format may be configured based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) used for the U-SIG may have a duration of 4 μs, and the U-SIG may have a total duration of 8 μs. Each symbol of the U-SIG may be used to send 26 bits of information. For example, each symbol of the U-SIG may be sent and received based on 52 data tones and 4 pilot tones.

[0112] The U-SIG may be constructed in units of 20 MHz. For example, if an 80 MHz PPDU is constructed, the U-SIG may be duplicated. That is, the same 4 U-SIGs may be included in the 80 MHz PPDU. A PPDU with a bandwidth exceeding 80 MHz may include a different U-SIG.

[0113] For example, A uncoded bits may be sent via U-SIG, the first symbol of U-SIG (e.g., U-SIG-1 symbol) may send the first X bits of information out of a total of A bits of information, and the second symbol of U-SIG (e.g., U-SIG-2 symbol) may send the remaining Y bits of information out of a total of A bits of information. The A bits of information (e.g., 52 uncoded bits) may include a CRC field (e.g., a 4-bit long field) and a tail field (e.g., a 6-bit long field). For example, the tail field may be used to terminate the trellis structure of the convolutional decoder and may be set to 0.

[0114] The bit information sent through U-SIG can be divided into version-independent bits and version-dependent bits. For example, U-SIG can be included in Figure 7 In a new PPDU format not shown in the EHT PPDU format (e.g., UHR PPDU format), and may be included in the format of the U-SIG field included in the EHT PPDU format and the format of the U-SIG field included in the UHR PPDU format, the version-independent bits may be the same, and some or all of the version-related bits may be different.

[0115] For example, the size of the version-independent bit of the U-SIG may be fixed or variable. The version-independent bit may be assigned only to the U-SIG-1 symbol, or to both the U-SIG-1 symbol and the U-SIG-2 symbol. The version-independent bit and the version-dependent bit may be referred to by various names, such as a first control bit and a second control bit.

[0116] For example, the version-independent bits of the U-SIG may include a 3-bit physical layer version identifier (PHY version identifier), and this information may indicate the PHY version (e.g., EHT, UHR, etc.) of the transmitted / received PPDU. The version-independent bits of the U-SIG may include a 1-bit UL / DL flag field. The first value of the 1-bit UL / DL flag field is related to UL communication, and the second value of the UL / DL flag field is related to DL communication. The version-independent bits of the U-SIG may include information about the length of a transmit opportunity (TXOP) and information about a BSS color ID.

[0117] For example, the version-related bits of the U-SIG may include information directly or indirectly indicating the type of the PPDU (eg, SU PPDU, MU PPDU, TB PPDU, etc.).

[0118] Information required for PPDU transmission and reception may be included in the U-SIG. For example, the U-SIG may also include information about bandwidth, information about an MCS technology applied to a non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.), information indicating whether a DCM (dual carrier modulation) technology (e.g., a technology for achieving an effect similar to frequency diversity by reusing the same signal on two subcarriers) is applied to the non-legacy SIG, information about the number of symbols used for the non-legacy SIG, and information about whether the non-legacy SIG is generated across the entire frequency band.

[0119] Some of the information required for PPDU transmission and reception may be included in the U-SIG and / or the non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.). For example, information about the type of non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information about the length of the non-legacy LTF and the CP (cyclic prefix) length, information about the GI (guard interval) applicable to the non-legacy LTF, information about preamble puncturing applicable to the PPDU, information about resource unit (RU) allocation, etc. may be included only in the U-SIG, only in the non-legacy SIG, or may be indicated by a combination of information included in the U-SIG and information included in the non-legacy SIG.

[0120] Preamble puncturing may indicate the transmission of a PPDU in which there is no signal in one or more frequency units in the bandwidth of the PPDU. For example, the size of the frequency unit (or the resolution of the preamble puncturing) may be defined as 20 MHz, 40 MHz, etc. For example, preamble puncturing may be applied to a PPDU bandwidth of a predetermined size or greater.

[0121] exist Figure 7In the example of , non-legacy SIGs such as HE-SIG-B and EHT-SIG may include control information for receiving STAs. The non-legacy SIG may be transmitted on at least one symbol, and one symbol may have a length of 4 μs. Information about the number of symbols used for the EHT-SIG may be included in a previous SIG (eg, HE-SIG-A, U-SIG, etc.).

[0122] Non-legacy SIGs such as HE-SIG-B and EHT-SIG may include a common field and a user-specific field. The common field and the user-specific field may be encoded separately.

[0123] In some cases, the common field may be omitted. For example, in a compressed mode that does not apply OFDMA (Orthogonal Frequency Division Multiple Access), the common field may be omitted, and multiple STAs may receive the PPDU (e.g., the data field of the PPDU) through the same frequency band. In a non-compressed mode that applies OFDMA, multiple users may receive the PPDU (e.g., the data field of the PPDU) through different frequency bands.

[0124] The number of user-specific fields may be determined based on the number of users. A user block field may include up to two user fields. Each user field may be associated with a MU-MIMO allocation or may be associated with a non-MU-MIMO allocation.

[0125] The common field may include a CRC bit and a tail bit, and the length of the CRC bit may be determined to be 4 bits, and the length of the tail bit may be determined to be 6 bits and set to 000000. The common field may include RU allocation information. The RU allocation information may include information about the positions of RUs to which multiple users (ie, multiple receiving STAs) are assigned.

[0126] RU can include multiple subcarriers (or tones). RU can be used when sending signals to multiple STAs based on OFDMA technology. In addition, RU can be defined even when sending signals to one STA. Resources can be allocated to non-traditional STF, non-traditional LTF and data fields in units of RU.

[0127] The RU of applicable size may be defined according to the PPDU bandwidth. The RU may be defined identically or differently for the applied PPDU format (e.g., HEPPDU, EHT PPDU, UHR PPDU, etc.). For example, in the case of an 80MHz PPDU, the RU layout of the HEPPDU and EHT PPDU may be different. The applicable RU size, the number of RUs and RU positions, the DC (direct current) subcarrier positions and numbers, the empty subcarrier positions and numbers, the guard subcarrier positions and numbers, etc. for each PPDU bandwidth may be referred to as a tone plan. For example, a tone plan for high bandwidth may be defined in the form of multiple iterations of a low bandwidth tone plan.

[0128] RUs of various sizes may be defined as 26-tone RUs, 52-tone RUs, 106-tone RUs, 242-tone RUs, 484-tone RUs, 996-tone RUs, 2×996-tone RUs, 3×996-tone RUs, etc. MRUs (multi-RUs) are different from multiple individual RUs and correspond to a group of subcarriers consisting of multiple RUs. For example, one 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. In addition, the multiple RUs constituting one MRU may or may not be continuous in the frequency domain.

[0129] The specific size of the RU may be reduced or expanded. Therefore, the specific size of each RU in the present disclosure (i.e., the number of corresponding tones) is not restrictive but illustrative. In addition, in the present disclosure, within a predetermined bandwidth (e.g., 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz ...), the number of RUs may vary according to the RU size.

[0130] Figure 7 The names of each field in the PPDU format are exemplary, and the scope of the present disclosure is not limited by these names. In addition, the examples of the present disclosure can be applied to Figure 7 The PPDU format shown in Figure 7 A new PPDU format that excludes some fields and / or adds some fields.

[0131] Figure 8 is a diagram illustrating an example format of a trigger frame to which the present disclosure may be applied.

[0132] The trigger frame may allocate resources for the transmission of one or more TB PPDUs and request the transmission of a TB PPDU. The trigger frame may also include other information required for the STA to send a TB PPDU in response. The trigger frame may include common information and user information list fields in the frame body.

[0133] The common info field is information that is generally applied to the transmission of one or more TB PPDUs requested by a trigger frame, such as trigger type, UL length, presence or absence of subsequent trigger frames (e.g., more TFs), CS (channel sensing) request, UL BW (bandwidth), HE / EHT P160, special user information field flag, etc.

[0134] The 4-bit Trigger Type subfield may have a value from 0 to 15. Among them, the value 0, value 1, value 2, value 3, value 4, value 5, value 6, and value 7 of the Trigger Type subfield are defined to correspond to Basic, Beamforming Report Poll (BFRP), Multi-User Block Acknowledgement Request (MU-BAR), Multi-User Request to Send (MU-RTS), Buffer Status Report Poll (BSRP), Multicast with Retry (GCR), MU-BAR, Bandwidth Query Report Poll (BQRP), and NDP Feedback Report Poll (NFRP), respectively, and values ​​8 to 15 are defined as reserved.

[0135] Among the common information, the trigger-related common information subfield may include information that is optionally included based on the trigger type.

[0136] A special user information field may be included in the trigger frame. The special user information field does not include user-specific information but includes extended common information that is not provided in the common information field.

[0137] A user information list includes zero or more user information fields. Figure 8 An example of the EHT variant user information field format is shown.

[0138] The AID12 subfield basically indicates that it is a user information field of the STA with the corresponding AID. In addition, if the AID12 field has a specific predetermined value, it can be used for other purposes, such as allocating a random access (RA)-RU or being configured as a special user information field. The special user information field is a user information field that does not include user-specific information but includes extended public information that is not provided in the common information field. For example, the special user information field can be identified by the AID12 value 2007, and the special user information field flag subfield within the common information field can indicate whether the special user information field is included.

[0139] The RU Allocation subfield may indicate the size and location of the RU / MRU. For this purpose, the RU Allocation subfield may be interpreted together with the PS160 (Primary / Secondary 160 MHz) subfield of the User Information field and the UL BW subfield of the Common Information field.

[0140] Wireless LAN (WLAN) Sensing Process

[0141] The WLAN sensing process (hereinafter referred to as the sensing process) refers to a process of obtaining identification information about the surrounding environment based on the channel environment (or state) information included in the signal sent from the transmitting end to the 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 obtained through the sensing process.

[0142] 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 motion detection.

[0143] The sensing process may consist of at least one of a sensing session establishment step, a sensing measurement establishment phase, a sensing measurement instance phase, a sensing measurement establishment termination phase, and a sensing session termination phase.

[0144] Here, a sensing session may be defined as a period of receiving / measuring a sensing signal after transmitting the sensing signal, and may consist of one or more sensing measurement instances.

[0145] A sensing session may consist of multiple subsessions, each of which may include a measurement phase and a reporting phase. Here, a subsession may be denoted as a sensing burst, a (sensing) measurement instance, or a measurement burst.

[0146] A STA that initiates a sensing process by transmitting a sensing measurement setup request frame or the like may be referred to as a sensing initiator, and a STA that participates in a sensing process (or a sensing session) in response to the sensing initiator may be referred to as a sensing responder.

[0147] The role of the STA that initiates the sensing process or participates in the sensing process can be a sensing transmitter and / or a sensing receiver. The sensing transmitter refers to the STA that sends the PPDU for measurement in the sensing process, and the sensing receiver refers to the STA that receives the PPDU received from the sensing transmitter in the sensing process and obtains the measurement result based on the PPDU.

[0148] SR2SR (sensing responder to sensing responder) sensing measurement process

[0149] In order to perform sensing measurement, the sensing initiator (e.g., AP) may send a sensing measurement request frame to the non-AP STA. The non-AP STA receiving the sensing measurement request frame may send a sensing measurement response frame to the sensing initiator to determine whether to perform sensing measurement. Through the above process, the sensing initiator and the sensing responder may perform sensing measurement establishment.

[0150] In addition, in addition to the above-mentioned sensing measurement process between the AP and the non-AP STA, the sensing measurement process between the non-AP STAs can also be used. That is, in order to improve the performance, efficiency and accuracy of the sensing measurement, SR2SR (or R2R (responder to responder)) can be performed in the next generation wireless LAN system.

[0151] SR2SR can be used for both the trigger-based (TB) detection process and / or the sensing by proxy (SBP) process. In the case of the SBP process, the non-AP STA can request the SBP process by becoming a sensing initiator and sending an SBP request frame to the AP. The SBP process can be initiated by the AP sending a response frame to the SBP process request frame to the non-AP STA.

[0152] In the following, a trigger-based process for performing SR2SR sensing measurements and a method for instructing SR2SR sensing measurements will be described. Fig. 9 and Fig.10 In the embodiment, the first STA (or sensing responder) may be a non-AP STA as a SR2SR sensing sender or a SR2SR sensing receiver, and the second STA may refer to an AP as a sensing initiator. However, this is only an implementation, and the first STA and the second STA may be one of a non-AP STA and an AP.

[0153] Fig. 9 is a diagram for explaining an operation performed by a first STA according to one embodiment of the present disclosure.

[0154] The first STA may receive a sensing trigger frame including a trigger-related common information subfield from the second STA ( S910 ).

[0155] Here, the trigger-related common information subfield may include a measurement session (or setup) ID field and a sensing trigger subtype field. The measurement session (or setup) ID field may include a measurement session ID corresponding to sensing measurement parameters associated with SR2SR probing based on the sensing trigger frame.

[0156] Here, a sensing measurement session may refer to a negotiation between a sensing initiator and a sensing responder regarding operating parameters related to a sensing measurement exchange for a given measurement session ID.

[0157] In addition, the sensing trigger subtype field may include information indicating that the subtype of the sensing trigger frame is a SR2SR (sensing responder to sensing responder) probe.

[0158] For example, the sensing trigger subtype field value may be set to 4, which may indicate that the trigger frame sent by the second STA is an SR2SR detection trigger frame. However, this is merely an implementation, and the sensing trigger subtype field value corresponding to the SR2SR detection trigger frame may be defined as a different value.

[0159] Here, the first STA may send information indicating whether SR2SR detection is supported to the second STA. The information indicating whether SR2SR detection is supported may be included in a sensing field and sent to the second STA. Here, the sensing field may be sent to the second STA through a sensing capability element (i.e., a field related to the capability of the first STA regarding sensing measurement).

[0160] The (SR2SR sounding) sensing trigger frame may include one sender user information (info) field and one or more receiver user information fields.

[0161] One sender user information field and each of the one or more receiver user information fields may include a Tx / Rx field (i.e., a field indicating the role of the first STA in the SR2SR sounding phase / process). And, one sender user information field may include a field indicating the number of HE (High Throughput)-LTF (Long Training Field) repetitions associated with the (SR2SR) NDP.

[0162] As another example, the sender user information field may include the ID of the STA performing the SR2SR sensing sender role.One or more receiver user information fields may include the ID of the STA performing the SR2SR sensing sender role and / or the ID of the STA performing the SR2SR sensing receiver role.

[0163] The first STA may receive (SR2SR) NDP from at least one STA or transmit (SR2SR) NDP to at least one STA based on the sensing trigger frame ( S920 ).

[0164] For example, based on the role of the first STA indicated by the Tx / Rx subfield included in the sender user information field of the sensing trigger frame as an SR2SR sensing sender, the first STA may send an (SR2SR) NDP to at least one STA. Here, at least one STA may be indicated as an SR2SR sensing receiver through the receiver user information field in the SR2SR detection phase.

[0165] As another example, based on the role of the first STA being indicated as an SR2SR sensing receiver by the Tx / Rx subfield included in a specific receiving user information field corresponding to the first STA among at least one receiving user information field, the first STA can receive an (SR2SR) NDP from an SR2SR sensing sender among at least one STA.

[0166] For example, based on receiving a sensing report trigger frame requesting measurement information based on (SR2SR) NDP from the second STA, the first STA may send a sensing measurement report frame to the second STA. For example, the sensing measurement report frame may include a measurement session ID field, an ID of an SR2SR receiver / transmitter (e.g., the first STA, etc.), and CSI acquired based on NDP.

[0167] Fig.10 is a diagram for explaining an operation performed by a second STA according to one embodiment of the present disclosure.

[0168] The second STA may send a sensing trigger frame including a trigger-related common information subfield to at least one STA (ie, at least one sensing responder) (S1010). Fig. 9 The configuration of the sensing trigger frame is described, and thus a repeated description will be omitted.

[0169] The second STA may send a sensing report trigger frame requesting NDP-based measurement information to the first STA among the at least one STA (S1020). Here, the role of the first STA in the SR2SR probing phase may be a SR2SR sensing receiver.

[0170] The second STA may receive a sensing measurement report frame from the first STA ( S1030 ).

[0171] Hereinafter, the SR2SR sensing process and the composition of a frame related to the SR2SR sensing process are described in detail.

[0172] The sensing initiator and the sensing responder performing the sensing measurement may send and receive sensing measurement request / response frames to each other to exchange information about the sensing measurement performed through the sensing measurement setup phase. Here, as an example, Fig.11 The sensing measurement setup phase for performing a sensing measurement process is shown executed.

[0173] For example, Fig.11 As illustrated in , a sensing initiator (eg, an AP) may send a sensing measurement setup request frame to a sensing responder during a sensing measurement setup phase to request sensing measurement.

[0174] The sensing measurement setup request frame may include information about sensing measurement parameters for performing sensing measurement. The sensing measurement parameters may include indication information about SR2SR measurement support. A sensing responder (e.g., a non-AP STA) receiving the sensing measurement setup request frame may send a sensing measurement setup response frame including information about whether SR2SR measurement is supported to the sensing initiator.

[0175] As an example of the present disclosure, Fig.12 (a) illustrates the format of the Sensing Measurement Parameters field including the SR2SR subfield.

[0176] Here, the indication information for SR2SR measurement support may be indicated through the SR2SR subfield. The SR2SR subfield may be transmitted by being included in the sensing measurement parameter field of the sensing measurement parameter element.

[0177] For example, the SR2SR subfield may consist of 1 bit. If the SR2SR subfield value is set to 1 (or 0), it may indicate that SR2SR measurement is supported. If the SR2SR subfield value is set to 0 (or 1), it may indicate that SR2SR measurement is not supported. However, this is merely one embodiment, and the bits of the SR2SR subfield and the corresponding indication information may be implemented differently.

[0178] The sensing measurement setup request / response frame transmitted and received by the sensing initiator and the sensing responder to perform sensing measurement may include a sensing measurement parameter element.

[0179] When the SR2SR subfield is included in the sensing measurement setup request frame, it may indicate that the sensing initiator allows the SR2SR measurement and may request the sensing responder for channel information between the sensing responders measured by the sensing responder.

[0180] When the SR2SR subfield is included in the sensing measurement setup response frame, it may indicate that the sensing responder may receive an NDP transmitted by another sensing responder to estimate channel information between (non-AP) STAs (ie, perform SR2SR measurement).

[0181] If a value of the SR2SR subfield transmitted via the sensing measurement setup response frame is set to 0 or an unsupported value, the sensing responder may not perform SR2SR measurement.

[0182] Through the sensing measurement setup between the sensing initiator (eg, AP) and the sensing responder (eg, non-AP STA), the AP may obtain information about the non-AP STA supporting SR2SR measurement.

[0183] Implementation Method 1

[0184] The triggered-based sensing measurement procedure may be performed by the AP to perform sensing measurement by a non-AP STA supporting SR2SR sensing measurement identified by the sensing measurement setup.

[0185] As an example of the present disclosure, Fig.13 As shown in (a), the sensing initiator (eg, AP) may trigger NDP transmission by sending a trigger frame to the non-AP STA1 acting as a sensing responder in the sensing measurement.

[0186] Non-AP STA 1 may send NDP to non-AP STA 2 supporting SR2SR sensing measurement based on the trigger frame. Non-AP STA 2 may perform SR2SR sensing measurement based on the NDP.

[0187] Specifically, the AP that has identified the non-AP STA supporting SR2SR measurement through the sensing measurement setup may request NDP transmission by sending a trigger frame to the non-AP STA 1 to perform the SR2SR measurement in the sensing measurement process.

[0188] For example, the trigger frame sent by the AP to request NDP transmission is a sensing trigger frame, and the sensing trigger subtype of the sensing trigger frame may be set / defined as a probing sensing trigger variant.

[0189] Additionally or alternatively, the sensing trigger subtype of the sensing trigger frame may be defined as a sensing trigger frame variant for SR2SR transmission. For example, the sensing trigger subtype of the sensing trigger frame may be defined as a SR2SR sensing variant or a SR2SR detection trigger variant.

[0190] For the convenience of explaining the present disclosure, the trigger frame is named as a detection sensing trigger variant, but is not limited thereto. The trigger frame may also be defined / named / set as a trigger frame for SR2SR measurement.

[0191] A probing sensing trigger variant for performing SR2SR measurement may be defined / set as a SR2SR measurement / probing variant.A sub-variant (or / and sub-type) of a sensing trigger frame may be indicated via a sensing trigger sub-type included in a trigger-related common information sub-field of the sensing trigger frame.

[0192] As an example, the sensing trigger subtype subfield may be configured as shown in Table 1. However, this is merely an example, and a sensing trigger frame sub-variant related to SR2SR detection may also be mapped to a reserved value (eg, one of 4 to 15).

[0193] [Table 1]

[0194] Sensor Trigger Subtype Subfield Value Sensor trigger frame variant 0 polling 1 Detection 2 SR2SR detection 3 Report 4-15 reserve

[0195] In another example of the present disclosure, a sub-variant for SR2SR measurement may not be separately defined / set, and a detection sub-variant may be applied / used. When a trigger frame set to the SR2SR sensing trigger sub-variant is transmitted, the TA included in the trigger frame may be set to the address of the AP, and the RA may be set to a non-AP STA (e.g., non-AP STA 1) that transmits a broadcast ID / NDP. Here, the trigger frame may include a user field for the non-AP STA that transmits the NDP.

[0196] In addition, the trigger frame may include an SR2SR sensing indication bit (eg, an SR2SR subfield) to indicate the SR2SR sensing measurement. In this case, the SR2SR sensing indication bit may be included in the trigger-related common information subfield of the trigger frame.

[0197] For example, the SR2SR subfield value may consist of 1 bit. If the SR2SR subfield value is set to 1 (or 0), this may indicate that SR2SR measurement is supported. If the SR2SR subfield value is set to 0 (or 1), this may indicate that SR2SR measurement is not supported.

[0198] like Fig.13 As shown in (a), the non-AP STA 2 performing the SR2SR sensing measurement may receive a trigger frame for the SR2SR sensing measurement sent by the AP (e.g., a value set in the SR2SR subfield included in the common information field of the trigger frame), and recognize that the SR2SR sensing measurement is performed.

[0199] Here, the trigger frame may include ID (identity) information (ie, measurement establishment ID) for identifying the sensing measurement associated with the trigger frame for SR2SR measurement feedback. For this purpose, the measurement establishment ID may be sent by being included in the trigger-related common information field of the trigger frame.

[0200] As described above, a trigger frame configured as a SR2SR sensing trigger / detection (sub) variant is used to trigger NDP transmission and may include a user field.

[0201] For example, the user field of the trigger frame (for SR2SR) may include AID information, BW / allocation information, "GI+LTF size (or / and type)" information, and NSS (number of spatial streams) information.

[0202] Here, the AID information may include ID information for the non-AP STA that transmits the NDP for SR2SR measurement.

[0203] And, the BW / allocation information may include BW information for NDP transmission. The BW / allocation information may consist of the same 2 bits as the UL BW of the common information field of the trigger frame (i.e., bits indicating the BW for transmitting the NDP). The BW for transmitting the NDP may indicate one of 20MHz, 40MHz, 80MHz, 160MHz, or 80MHz+80MHz.

[0204] As another example, the BW / allocation information may consist of 3 bits. In this case, the BW / allocation information may also indicate a BW of 320 MHz or more as the BW for transmitting the NDP.

[0205] Additionally or alternatively, the BW extension field may be used to indicate a BW of 320 MHz or greater, and the BW extension field may consist of 1 bit. For example, if the BW extension field value is set to 1, this may indicate a BW of 320 MHz, and if the BW extension field value is set to 0, this may indicate a BW of less than 320 MHz.

[0206] For example, the BW for transmitting the NDP indicated by the BW / allocation information may be configured to be less than or equal to the BW of the UL BW of the common information field of the trigger frame.

[0207] For example, the BW / allocation information included in the user information field in the corresponding trigger frame may include puncturing information. That is, the BW / allocation information may be configured with 5 bits to indicate the puncturing information. The non-AP STA may confirm the BW for transmitting the NDP through the UL BW subfield of the common information field of the corresponding trigger frame, and may confirm the information punctured within the BW through the BW / allocation information field.

[0208] The "GI+LTF size (or / and type)" information may be used to indicate information about the GI and LTF sizes used when sending NDP. Specifically, the non-AP STA sends NDP using the SU format, and the GI and LTF sizes may be confirmed through the "GI+LTF size (or / and type)" information.

[0209] Here, the 'GI+LTF size (or / and type)' information included in the user information field may be configured differently from the 'GI+LTF type' information transmitted through the common information field of the corresponding trigger frame.

[0210] For example, the "GI+LTF size (or / and type)" information may consist of 2 bits as shown in Table 2 below.

[0211] [Table 2]

[0212] GI+LTF size subfield value Sensor Trigger Frame Variant 0 2×HE LTF+0.8us GI 1 2×HE LTF+1.6us GI 2 4×HE LTF+3.2us GI 3 reserve

[0213] As another example of the present disclosure, when a trigger frame set to the SR2SR 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 configuration (e.g., according to the configuration of Table 2, etc.). Then, the “GI+LTF size subfield” of the common information field of the trigger frame may indicate information about the GI and LTF type (or / and size) for NDP transmission using the SU format.

[0214] For example, if the common information field of the trigger frame includes the "GI+LTF size subfield" configured as described above, the user information field of the trigger frame may not include the "GI+LTF size subfield".

[0215] The NSS information may indicate the number of spatial streams allocated when the NDP is transmitted. For example, the NSS information may consist of 3 bits and may indicate one of 1 to 8 as the number of spatial streams.

[0216] Reference Fig.13 (a), non-AP STA 1 that has received the SR2SR sensing trigger frame from the AP can send an NDP for SR2SR measurement to another non-AP STA. Here, the NDP can be configured using the SU PPDU format. For example, the NDP can be configured using the HE NDP format or the EHT NDP format.

[0217] Non-AP STA 2, which has received the NDP transmitted by non-AP STA 1, may perform channel measurement between non-AP STA 1 and non-AP STA 2 using the received NDP.

[0218] Here, non-AP STA 2 may be a STA that supports SR2SR measurement through sensing measurement establishment. Non-AP STA 2 may determine that the SR2SR measurement process is performed by receiving a trigger frame sent by the AP for requesting NDP transmission. Here, non-AP STA 1 and / or non-AP STA 2 may determine that non-AP STA 1 transmits NDP through a user field included in the trigger frame.

[0219] In order to receive channel information measured by non-AP STA 2, the AP may send a feedback request trigger frame to non-AP STA 2.

[0220] The feedback request process may be performed in the sensing report phase, and the feedback request process may support an immediate feedback process and a delayed feedback process.

[0221] The non-AP STA 2 that has received the feedback request trigger frame may transmit measurement information (eg, CSI information) to the AP using report-related parameters included in the feedback request trigger frame.

[0222] The CSI information transmitted by the non-AP STA 2 may be transmitted to the AP through a sensing report frame. Here, the sensing report frame may include the ID information of the receiving STA, AID or UID (USID).

[0223] like Fig.13 As shown in (a), each frame transmission may be performed at a SIFS interval, but is not limited thereto. Various types of IFS may be considered for each frame transmission. As another example, an IFS having an interval greater than SIFS may be applied to the transmission of a feedback request frame and a feedback report frame.

[0224] Implementation Method 2

[0225] like Fig.13 As shown in (b), when the AP sends a trigger frame to perform SR2SR sensing measurement, the trigger frame may include a user field for a non-AP STA to perform the SR2SR sensing measurement.

[0226] Specifically, the trigger frame may be a sub-variant of the sensing trigger frame, and may include information of the Tx non-AP STA and the Rx non-AP STA.

[0227] The indication for the sub-variant may be performed via the sensing trigger sub-type of the trigger-related common information sub-field of the sensing trigger frame. As an example, the detection sub-variant may be indicated by the sensing trigger sub-type for SR2SR measurement. As another example, when a new sub-variant (or sub-type) for SR2SR measurement is defined, the new sub-variant may be indicated as one of the reserved values ​​that does not include a value corresponding to an existing sub-variant in the sensing trigger sub-type.

[0228] For example, a sensing trigger frame having an SR2SR sub-variant or a detection sub-variant set may include an SR2SR sensing indication bit (eg, an SR2SR subfield) to indicate SR2SR sensing measurement. Here, the SR2SR sensing indication bit may be sent by being included in the trigger-related common information subfield of the trigger frame.

[0229] For example, the SR2SR subfield may consist of 1 bit. When the SR2SR subfield value is set to 1 (or 0), it may indicate that SR2SR measurement is supported. When the SR2SR subfield value is set to 0 (or 1), it may indicate that SR2SR measurement is not supported.

[0230] Additionally or alternatively, the SR2SR subfield value may be set to 1 only when SR2SR is measured, and may be set to 0 or reserved in other cases.

[0231] That is, in sub-variants of the sensing trigger frame for SR2SR measurement (ie, polling, probing, reporting, etc.), the SR2SR subfield value may always be set to 1.

[0232] like Fig.13 As shown in (b), the non-AP STA performing the SR2SR sensing measurement can confirm whether to perform the SR2SR sensing measurement through the trigger frame for the SR2SR sensing measurement sent by the AP (for example, for the value set of the SR2SR subfield included in the relevant common information subfield).

[0233] Here, the trigger frame may include ID (identity) information (ie, measurement establishment ID) for identifying the sensing measurement associated with the trigger frame for SR2SR measurement feedback. To this end, the measurement establishment ID may be sent by being included in the trigger-related common information field of the trigger frame.

[0234] For example, Fig.12 As shown in (b), the trigger-related common information field of the trigger frame may be configured. Additionally or alternatively, the trigger-related common information field may be configured with 2 bytes including a measurement establishment ID.

[0235] Additionally or alternatively, when performing SR2SR sensing measurement, the sounding sensing trigger frame may be used as a sensing trigger frame. In this case, a specific subfield of the user information field of the sensing trigger frame may be used to indicate SR2SR sensing to the non-AP STA.

[0236] The user information field of the detection sensing trigger frame may include an SR2SR subfield. For example, if the SR2SR subfield value is set to 1, this may indicate that SR2SR measurement is performed. If the SR2SR subfield value is set to 0 when performing general sensing measurement, this may indicate that SR2SR measurement is not performed.

[0237] In addition, when SR2SR sensing measurement is performed, the SR2SRTx / Rx subfield may be defined in the user field of the sounding sensing trigger frame to indicate the NDP transmitting STA and the NDP receiving STA.

[0238] When the SR2SR field value included in the user information field is set to 1, the SR2SR Tx / Rx subfield may be valid. For example, for a Tx STA (ie, a STA that transmits NDP), the SR2SR Tx / Rx field value (sent and received by the Tx STA) may be set to 1 (or 0). For an Rx STA (ie, a STA that receives NDP), the SR2SR Tx / Rx field value (sent and received by the Rx STA) may be set to 0 (or 1). This is an embodiment, and the SR2SR Tx / Rx subfield value may be set differently.

[0239] If the SR2SR subfield value is 0, the SR2SR Tx / Rx subfield may be considered as an ignored bit or reserved.

[0240] When sending the SR2SR / Probe Sensing Trigger sub-variant, TA is set to the address of the AP that sent the trigger frame, and RA may be set to a broadcast ID or a multicast ID.

[0241] The SR2SR / probing sensing trigger sub-variant may include a user information field for STAs participating in SR2SR sensing measurements. In this case, the user information field may consist of a user information field for each of the Tx STA and Rx STA performing SR2SR measurements.

[0242] Each user information field for each of the Tx STA and the Rx STA may include AID information, SR2SRTx / Rx operation (or SR2SR role indication), BW / allocation information, "GI+LTF size (or / and type)" information and NSS (number of spatial streams) information, measurement ID, and SR2SR subfield.

[0243] Here, the AID information may include ID information for a non-AP STA performing R2R measurement. The AID information may include ID for a Tx non-AP STA or an Rx non-AP STA. The ID may include ID information for an associated STA or a non-associated STA.

[0244] The Tx / Rx operation or R2R role indication information may include information for indicating a role or Tx / Rx operation of a non-AP STA during R2R measurement.

[0245] For example, the Tx / Rx operation or R2R role indication information may consist of 1 bit. When the bit value corresponding to the Tx / Rx operation or R2R role indication information is set to 0 (or 1), this may indicate an Rx operation or a receiver role. Also, when the bit value corresponding to the Tx / Rx operation or R2R role indication information is set to 1 (or 0), this may indicate a Tx operation or a transmitter role.

[0246] The bit value (or field including the bit) corresponding to the Tx / Rx operation or R2R role indication information included in the user (information) field for the Tx non-AP STA may always be set to 1 (or 0). Also, the bit value (or field including the release bit) corresponding to the Tx / Rx operation or R2R role indication information included in the user (information) field for the Rx non-AP STA may always be set to 0 (or 1).

[0247] The BW / allocation information may include BW information for NDP transmission / reception (e.g., feedback). The BW / allocation information may consist of the same 2 bits (i.e., bits indicating the BW for transmitting the NDP) as the UL BW of the common information field of the trigger frame described in Embodiment 1. The BW for transmitting the NDP may indicate one of 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 80 MHz+80 MHz.

[0248] As another example, the BW / allocation information may consist of 3 bits. In this case, the BW / allocation information may also indicate a BW of 320 MHz or more as the BW for transmitting the NDP.

[0249] For example, the BW for transmitting the NDP indicated by the BW / allocation information may be configured to be less than or equal to the BW of the UL BW of the common information field of the trigger frame.

[0250] For example, the BW / allocation information included in the user information field in the corresponding trigger frame may include puncturing information. That is, the BW / allocation information may be configured with 5 bits to indicate the puncturing information. The non-AP STA may identify the BW in which the NDP is transmitted through the UL BW subfield of the common information field of the corresponding trigger frame, and may identify the information punctured within the BW through the BW / allocation information field.

[0251] For example, the BW information may be used identically to the UL BW information in the common information field, and the user information field may not include the BW information.

[0252] The "GI+LTF size (or / and type)" information may be used to indicate information about the GI and LTF sizes used when sending NDP. Specifically, the non-AP STA sends NDP using the SU format, and the GI and LTF sizes may be confirmed through the "GI+LTF size (or / and type)" information.

[0253] Here, the 'GI+LTF size (or / and type)' information included in the user information field may be configured differently from the 'GI+LTF type' information transmitted through the common information field of the corresponding trigger frame.

[0254] For example, the “GI+LTF size (or / and type)” information may consist of 2 bits as shown in Table 3.

[0255] As another example of the present disclosure, when a trigger frame set to an SBP / R2R sensing trigger (sub) variant is sent, the "GI+LTF size subfield" of the common information field of the trigger frame can be configured according to the above configuration (for example, according to the configuration of Table 3, etc.).

[0256] In addition, the 'GI+LTF size' subfield of the common information field of the trigger frame may indicate information about the GI and LTF type (or / and size) for NDP transmission using the SU format.

[0257] For example, if the common information field of the trigger frame includes the 'GI+LTF size subfield' configured as described above, the user information field of the trigger frame may not include the 'GI+LTF size subfield'.

[0258] The NSS information may indicate the number of spatial streams allocated when the NDP is transmitted. For example, the NSS information may consist of 3 bits and may indicate one of 1 to 8 as the number of spatial streams.

[0259] The measurement ID may be composed of ID information which is information for indicating R2R measurement. The ID indicated by the measurement ID may be set to an establishment ID determined during the R2R process establishment, or may be set to a sensing measurement establishment ID.

[0260] The SR2SR subfield may include information for indicating SR2SR measurement. For example, if the SR2SR field value is set to 1, this may indicate that SR2SR measurement is performed, and if the SR2SR field value is set to 0, this may indicate that SR2SR measurement is not performed.

[0261] The AP may transmit a trigger frame including a user field for STAs participating in SR2SR sensing measurement. At this time, the non-AP STAs performing SR2SR measurement (e.g., non-AP STA 1, non-AP STA 2, ..., non-AP STA n) may confirm the performance of SR2SR measurement by confirming the AID included in the user information field. In addition, the non-AP STAs may confirm the actions and / or roles they perform during the SR2SR sensing measurement through the user information field.

[0262] For example, the user information field included in the trigger frame for SR2SR sensing measurement sent by the AP may be as follows: Fig.12 Configure as in (c).

[0263] For example, the first user (information) field may include information about a non-AP STA (ie, Tx STA) that transmits an NDP during SR2SR measurement. One or more user fields following the first user field may be user fields for a STA (ie, Rx STA) that receives an NDP transmitted by other STAs and measures a channel.

[0264] like Fig.12 As shown in (c), the non-AP STA that has detected the execution of the SR2SR measurement through the trigger frame transmitted by the AP may transmit and receive the NDP based on the information received through the trigger frame.

[0265] The NDP transmission and reception process and subsequent processes may be the same as in Embodiment 1. When the measurement ID is included in the trigger frame, the measurement ID information may be transmitted and received in the feedback request frame and the feedback report frame. The feedback report frame may include the ID information of the receiving STA that transmits the CSI information.

[0266] In order to receive CSI information measured by a STA using NDP received from another STA through SR2SR measurement, the AP (ie, the sensing initiator) may use Fig.13 The reporting process shown in (a) and (b).

[0267] Specifically, the AP (ie, a sensing initiator) may transmit a report sensing trigger frame to a non-AP STA (ie, a sensing responder or a SR2SR receiving STA) to request CSI information measured through SR2SR sensing measurement.

[0268] The Report Sensing Trigger frame sent by the AP may be configured identically to the Report Sensing Trigger frame sent to request CSI feedback from sensing measurements.

[0269] The non-AP STA (i.e., the sensing responder) performing the SR2SR sensing measurement can include the measured CSI information in the report frame using the report sensing trigger frame received from the AP. Then, the non-AP STA (i.e., the sensing responder) can use the TBPPDU to send the CSI information included in the report frame through the allocated RU or BW.

[0270] In order to indicate CSI information for SR2SR sensing measurement to the AP, feedback CSI information transmitted by a non-AP STA (ie, a sensing responder) may be transmitted via a sensing report frame. Here, the sensing report frame may include ID information of the corresponding STA, AID or UID (USID).

[0271] The sensing report frame may include ID information of the STA that transmits the NDP (ie, the ID of the Tx STA).

[0272] The AP (ie, the sensing initiator) may determine which STA channel information the received CSI is through the report frame fed back by the non-AP STA (ie, the sensing responder).

[0273] The above-mentioned embodiments are to combine the elements and features of the present disclosure in a predetermined form. Unless otherwise explicitly mentioned, each element or feature should be regarded as optional. Each element or feature can be implemented in a form that is not combined with other elements or features. In addition, the embodiments of the present disclosure may include a combination of some elements and / or features. The order of the operations described in the embodiments of the present disclosure may be changed. Some elements or features of an embodiment may be included in other embodiments, or may be replaced by corresponding elements or features of other embodiments. Obviously, the embodiments may include claims that do not have a clear reference relationship in the combined claims, or may be included as new claims by modification after application.

[0274] It is clear to those skilled in the relevant art that the present disclosure can be implemented in other specific forms within the scope of the essential features of the present disclosure. Therefore, the above detailed description should not be interpreted restrictively in every aspect, but should be considered as illustrative. The scope of the present disclosure should be determined by the reasonable interpretation of the attached claims, and all changes within the equivalent scope of the present disclosure are included in the scope of the present disclosure.

[0275] The scope of the present disclosure includes software or machine executable commands (e.g., operating systems, applications, firmware, programs, etc.) that perform operations in a device or computer according to the methods of various embodiments, and non-transitory computer-readable media that enable software or commands, etc. to be stored and executable in a device or computer. Commands that can be used to program a processing system that performs the features described in the present disclosure can be stored in a storage medium or a computer-readable storage medium, and the features described in the present disclosure can be implemented by using a computer program product that includes such a storage medium. The storage medium may include a high-speed random access memory, such as, for example, DRAM, SRAM, DDR RAM, or other random access solid-state storage devices, but is not limited thereto, and it may include non-volatile memory, such as, for example, 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 located away from the processor. The memory, or alternatively, the non-volatile memory device in the memory includes a non-transitory computer-readable storage medium. The features described in this disclosure may be stored in any machine-readable medium to control the hardware of a processing system, and may be integrated into software and / or firmware that allows the processing system to interact with other mechanisms using the results from the embodiments of this disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0276] Industrial Applicability

[0277] The method proposed in the present disclosure is mainly described based on an example applied to a system based on IEEE 802.11 (5G system), but can be applied to various WLAN or wireless communication systems other than the system based on IEEE 802.11.

Claims

1. A method performed by a first station STA in a wireless LAN system, the method comprising the following steps: receiving, from a second STA, a sensing trigger frame including a trigger-related common information subfield; as well as Based on the sensing trigger frame, receiving a null data physical protocol data unit NDP from at least one STA or sending the NDP to the at least one STA, The trigger-related public information subfield includes a measurement session ID field and a sensing trigger subtype field, and The sensing trigger subtype field includes information indicating that the subtype of the sensing trigger frame is sensing responder to sensing responder SR2SR detection.

2. The method according to claim 1, wherein: The measurement session ID field includes a measurement session ID corresponding to a sensing measurement parameter associated with the SR2SR probe based on the sensing trigger frame.

3. The method according to claim 1, wherein: Send information indicating whether the SR2SR detection is supported to the second STA.

4. The method according to claim 1, wherein: The first STA sends the NDP to the at least one STA based on indicating the role of the first STA as the SR2SR sensing sender through the Tx / Rx subfield included in the sender user information field of the sensing trigger frame.

5. The method according to claim 1, wherein: Each of the at least one receiver user information field of the sensing trigger frame includes a Tx / Rx subfield, and The NDP is sent from an SR2SR sensing transmitter among the at least one STA to the first STA based on indicating the role of the first STA as an SR2SR sensing receiver through a Tx / Rx subfield included in a specific receiver user information field corresponding to the first STA among the at least one receiver user information field.

6. The method according to claim 5, wherein: Based on receiving a sensing report trigger frame requesting measurement information based on the NDP from the second STA, a sensing measurement report frame is sent from the first STA to the second STA.

7. The method according to claim 5, wherein: The specific receiver user information field includes the ID of the first STA and the ID of the SR2SR sensing sender.

8. The method according to claim 6, wherein: The sensing measurement report frame includes the measurement session ID field, the ID of the first STA, and channel state information CSI obtained based on the NDP.

9. The method according to claim 1, wherein: The sensing trigger frame includes a field indicating a number of repetitions of a high throughput HE-long training field (LTF) associated with the NDP.

10. The method according to claim 1, wherein: The first STA is a non-AP STA that serves as a SR2SR sensing transmitter or a SR2SR sensing receiver, and The second STA is an AP serving as a sensing initiator.

11. A first station STA operating in a wireless LAN system, the first STA comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: receiving, by the at least one transceiver, a sensing trigger frame including a trigger-related common information subfield from a second STA; and Based on the sensing trigger frame, receiving a null data physical protocol data unit NDP from at least one STA through the at least one transceiver or sending the NDP to the at least one STA through the at least one transceiver, The trigger-related public information subfield includes a measurement session ID field and a sensing trigger subtype field, and The sensing trigger subtype field includes information indicating that the subtype of the sensing trigger frame is sensing responder to sensing responder SR2SR detection.

12. A method performed by a second station (STA) in a wireless LAN system, the method comprising the following steps: Sending a sensing trigger frame including a trigger-related common information subfield to at least one STA; Sending a sensing report trigger frame requesting NDP-based measurement information to a first STA among the at least one STA; as well as receiving a sensing measurement report frame from the first STA, The trigger-related public information subfield includes a measurement session ID field and a sensing trigger subtype field, and The sensing trigger subtype field includes information indicating that the subtype of the sensing trigger frame is sensing responder to sensing responder SR2SR detection.

13. A second station STA operating in a wireless LAN system, the second STA comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: Sending, by the at least one transceiver, trigger information for sending a null data physical protocol data unit PPDUNDP announcement frame to at least one STA; Sending, by the at least one transceiver, a sensing report trigger frame requesting measurement information based on the NDP to a first STA among the at least one STA; and receiving, by the at least one transceiver, a sensing measurement report frame from the first STA, The trigger-related public information subfield includes a measurement session ID field and a sensing trigger subtype field, and The sensing trigger subtype field includes information indicating that the subtype of the sensing trigger frame is sensing responder to sensing responder SR2SR detection.

14. A processing device, the processing device being configured to control a first station STA in a wireless LAN system, the processing device comprising: at least one processor; as well as at least one computer memory operatively connected to the at least one processor and storing instructions that upon execution by the at least one processor perform operations comprising: receiving a sensing trigger frame including a trigger-related common information subfield from a second STA; and Based on the sensing trigger frame, receiving a null data physical protocol data unit NDP from at least one STA or sending the NDP to the at least one STA, The trigger-related public information subfield includes a measurement session ID field and a sensing trigger subtype field, and The sensing trigger subtype field includes information indicating that the subtype of the sensing trigger frame is sensing responder to sensing responder SR2SR detection.

15. At least one non-transitory computer-readable medium storing at least one instruction, in, The at least one instruction executable by at least one processor controls a device in a wireless LAN system to: receiving a sensing trigger frame including a trigger-related common information subfield from a second STA; and Based on the sensing trigger frame, receiving a null data physical protocol data unit NDP from at least one STA or sending the NDP to the at least one STA, The trigger-related public information subfield includes a measurement session ID field and a sensing trigger subtype field, and The sensing trigger subtype field includes information indicating that the subtype of the sensing trigger frame is sensing responder to sensing responder SR2SR detection.

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