Method and apparatus for performing sensing procedures in a wireless LAN system

Abstract

A method and apparatus for operating in a wireless LAN system are disclosed. In one embodiment of the present disclosure, a method performed by a first STA in a wireless LAN system includes the steps of: transmitting a first frame to a second STA to request an SBP (sensing by proxy) procedure; receiving a second frame from the second STA in response to the first frame; and receiving a third frame from the second STA related to a sensing measurement report based on the first frame, wherein the first frame may include first information related to an SR2SR (sensing responder to sensing responder) sounding procedure, and second information indicating whether or not the first STA participates in the SR2SR sounding procedure.

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 a collaborative sensing procedure in a WLAN system.

Background Art

[0002] New technologies for improving transmission rate, increasing bandwidth, improving reliability, reducing errors, reducing latency, etc. have been introduced for wireless local area network (WLAN). Among WLAN technologies, the standards of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series can be referred to as Wi-Fi. For example, technologies recently introduced to WLAN include enhancements for the very high throughput (VHT) of the 802.11ac standard and enhancements for the high efficiency (HE) of the IEEE 802.11ax standard.

[0003] Improved technologies for providing sensing for devices using WLAN signals have been discussed. For example, in the IEEE 802.11 task group (TG) bf, development of standard technologies for performing sensing on objects (such as people, objects, etc.) based on channel estimation using WLAN signals between devices operating in a frequency band below 7 GHz has been carried out. Object sensing based on WLAN signals has the advantages of being able to utilize existing frequency bands and having a lower potential for privacy infringement compared to existing sensing technologies. With the increase in the frequency range utilized by WLAN technology, it has become possible to obtain precise sensing information, and at the same time, technologies for reducing power consumption to efficiently support precise sensing procedures have also been studied.

Summary of the Invention

[0004] The technical problem addressed by this disclosure is to provide a method and apparatus for performing cooperative sensing in a wireless LAN system.

[0005] The technical problem addressed in this disclosure is to provide a method and apparatus for performing a cooperative sensing procedure based on SBP (sensing by proxy) capability in a wireless LAN system.

[0006] The technical challenges addressed in this disclosure are not limited to those mentioned above, and other technical challenges not mentioned will be clearly understood by those with ordinary skill in the art to which this disclosure pertains from the following description. [Means for solving the problem]

[0007] A method performed by a first station (STA) in a wireless LAN system according to one embodiment of the present disclosure includes the steps of: transmitting a first frame to a second STA to request an SBP (sensing by proxy) procedure; receiving a second frame from the second STA in response to the first frame; and receiving a third frame from the second STA related to a sensing measurement report based on the first frame, wherein the first frame may include first information related to an SR2SR (sensing responder to sensing responder) sounding procedure, and second information indicating whether or not the first STA participates in the SR2SR sounding procedure.

[0008] As one embodiment of the present disclosure, a method performed by a second station (STA) in a wireless LAN system includes the steps of: receiving a first frame from a first STA to request an SBP (sensing by proxy) procedure; transmitting a second frame to the first STA in response to the first frame; and transmitting a third frame to the first STA based on the first frame relating to a sensing measurement report, wherein the first frame may include first information relating to an SR2SR (sensing responder to sensing responder) sounding procedure, and second information indicating whether or not the first STA participates in the SR2SR sounding procedure. [Effects of the Invention]

[0009] Various embodiments of this disclosure can provide a method and apparatus for performing cooperative sensing in a wireless LAN system.

[0010] Various embodiments of this disclosure provide methods and apparatus for performing SBP capacity-based collaborative sensing procedures in a wireless LAN system.

[0011] Various embodiments of this disclosure enable collaborative sensing by STAs within specific areas of BSS (basic service set) coverage, thereby reducing the power consumption of these STAs.

[0012] Through various embodiments of this disclosure, more accurate channel information can be obtained by having one or more STAs perform cooperative sensing.

[0013] The effects derived from this disclosure are not limited to those mentioned above, and any other effects not mentioned above will be clearly understood by a person with ordinary skill in the art to which this disclosure pertains from the following description. [Brief explanation of the drawing]

[0014] The accompanying drawings, included as part of the detailed description to aid in understanding this disclosure, provide examples of the disclosure and illustrate the technical features of the disclosure together with the detailed description.

[0015] [Figure 1] This is a block diagram illustrating an example of a wireless communication device according to one embodiment of the present disclosure. [Figure 2] This figure shows an exemplary structure of a wireless LAN system to which this disclosure can be applied. [Figure 3] This diagram illustrates the link setup process to which this disclosure applies. [Figure 4] This diagram illustrates the backoff process to which this disclosure applies. [Figure 5] This diagram illustrates the CSMA / CA baseframe transmission operation to which this disclosure can be applied. [Figure 6] This figure illustrates an example of a frame structure used in a wireless LAN system to which this disclosure can be applied. [Figure 7] This figure shows an example of a PPDU as defined in the IEEE 802.11 standard to which this disclosure applies. [Figure 8] This is a diagram illustrating the operation performed by the first STA according to one embodiment of the present disclosure. [Figure 9] This is a diagram illustrating the operation performed by the second STA according to one embodiment of the present disclosure. [Figure 10] This is a diagram illustrating an SBP-based sensing procedure according to one embodiment of the present disclosure. [Figure 11] This is a diagram illustrating an SBP-based sensing procedure according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0016] Hereinafter, preferred embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed below together with the accompanying drawings is for explaining exemplary embodiments of the present disclosure, and is not for showing the only embodiments in which the present disclosure can be implemented. The following detailed description includes specific details for providing a complete understanding of the present disclosure. However, it is understood by those skilled in the art that the present disclosure can be implemented without such specific details.

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

[0018] In the present disclosure, when a certain component is "connected", "coupled" or "connected" to another component, this may include not only a direct connection relationship, but also an indirect connection relationship in which there are further other components between them. Also, in the present disclosure, the terms "comprising" or "having" are used to specify the existence of the recited features, steps, operations, elements and / or components, but do not exclude the existence or addition of one or more other features, steps, operations, elements, components and / or groups thereof.

[0019] In the present disclosure, terms such as "first", "second", etc. are used only for the purpose of distinguishing one component from another, and are not used to limit the components. Unless otherwise specified, they do not limit the order or importance, etc. between the components. Therefore, within the scope of the present disclosure, the first component in one embodiment can also be referred to as the second component in another embodiment, and similarly, the second component in one embodiment can also be referred to as the first component in another embodiment.

[0020] The terms used in this disclosure are for illustrative purposes relating to specific embodiments and are not intended to limit the scope of the claims. As used in the description of the embodiments and in the attached claims, singular forms are intended to include plural forms unless otherwise specified in the context. The terms "and / or" used in this disclosure may refer to one of the related enumerated items, or to any and all possible combinations of two or more of them. In this disclosure, a " / " between words has the same meaning as "and / or" unless otherwise specified.

[0021] The examples in this disclosure may be applied to various wireless communication systems. For example, the examples in this disclosure may be applied to wireless LAN systems. For example, the examples in this disclosure may be applied to IEEE 802.11a / g / n / ac / ax standard-based wireless LANs. Furthermore, the examples in this disclosure may be applied to newly proposed IEEE 802.11bn (or UHR) standard-based wireless LANs. In addition, the examples in this disclosure may be applied to next-generation standard-based wireless LANs following IEEE 802.11bn. Moreover, the examples in this disclosure may be applied to cellular wireless communication systems. For example, they may be applied to cellular wireless communication systems based on 3GPP (3rd Generation Partnership Project: registered trademark: hereinafter the same) standard LTE (Long Term Evolution) series technologies and 5G NR (New Radio) series technologies.

[0022] The following describes the technical features to which the examples in this disclosure may apply.

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

[0024] The first device 100 and the second device 200 illustrated in Figure 1 may be replaced with various terms such as terminal, wireless device, WTRU (Wireless Transmit Receive Unit), UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), MSS (Mobile Subscriber Unit), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), or simply user. Furthermore, the first device 100 and the second device 200 may be replaced with various terms such as access point (AP), BS (Base Station), fixed station, Node B, BTS (base transceiver system), network, AI (Artificial Intelligence) system, RSU (roadside unit), repeater, router, relay, gateway, etc.

[0025] The devices 100 and 200 illustrated in Figure 1 can also be referred to as stations (STA). For example, the devices 100 and 200 illustrated in Figure 1 can be referred to by various terms such as transmitting device, receiving device, transmitting STA, and receiving STA. For example, STA 110 and 200 can play the role of an AP (access point) or a non-AP. That is, in this disclosure, STA 110 and 200 may have AP and / or non-AP functions. When STA 110 and 200 have AP functions, they can simply be called APs, and when STA 110 and 200 have non-AP functions, they can simply be called STAs. In addition, in this disclosure, AP may be represented as AP STA.

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

[0027] Furthermore, the first device 100 and the second device 200 can also further support various communication standards other than Wi-Fi technology (e.g., 3GPP LTE series, 5G NR series standards, etc.). The devices of this disclosure may also be embodied in various devices such as mobile phones, vehicles, personal computers, Augmented Reality (AR) equipment, and Virtual Reality (VR) equipment. In addition, the STA of this specification can support various communication services such as voice calls, video calls, data communication, autonomous driving, Machine-Type Communication (MTC), Machine-to-Machine (M2M), Device-to-Device (D2D), and Internet of Things (IoT).

[0028] The first device 100 includes one or more processors 102 and one or more memories 104, and may further include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memories 104 and / or the transceivers 106 and be configured to embody the descriptions, functions, procedures, suggestions, methods and / or operation diagrams of this disclosure. For example, the processor 102 may process information in the memory 104 to generate first information / signals and then transmit a radio signal containing the first information / signals via the transceiver 106. Alternatively, the processor 102 may receive a radio signal containing second information / signals via the transceiver 106 and then store information obtained from signal processing of the second information / signals in the memory 104. The memory 104 may be linked to the processor 102 and can store various information relating to the operation of the processor 102. For example, memory 104 may store software code that executes some or all of a process controlled by processor 102, or that contains instructions for executing the descriptions, functions, procedures, suggestions, methods and / or operation sequence diagrams in this disclosure. Here, processor 102 and memory 104 may be part of a communication modem / circuit / chip designed to embody wireless LAN technology (e.g., IEEE 802.11 series). Transceiver 106 may be coupled with processor 102 and can transmit and / or receive radio signals via one or more antennas 108. Transceiver 106 may include a transmitter and / or receiver. Transceiver 106 may be used synonymously with RF (Radio Frequency) unit. In this disclosure, device may also mean communication modem / circuit / chip.

[0029] The second device 200 includes one or more processors 202, one or more memories 204, and may further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memories 204 and / or the transceivers 206 and be configured to embody the descriptions, functions, procedures, suggestions, methods and / or operation sequence diagrams disclosed herein. For example, the processor 202 may process information in the memory 204 to generate third information / signals and then transmit a radio signal containing the third information / signals via the transceiver 206. Alternatively, the processor 202 may receive a radio signal containing fourth information / signals via the transceiver 206 and then store information obtained from signal processing of the fourth information / signals in the memory 204. The memory 204 may be linked to the processor 202 and can store various information related to the operation of the processor 202. For example, memory 204 may store software code that executes some or all of the processes controlled by processor 202, or that contains instructions for executing the descriptions, functions, procedures, suggestions, methods and / or operation sequence diagrams disclosed in this disclosure. Here, processor 202 and memory 204 may be part of a communication modem / circuit / chip designed to embody wireless LAN technology (e.g., IEEE 802.11 series). Transceiver 206 may be coupled with processor 202 and may transmit and / or receive radio signals via one or more antennas 208. Transceiver 206 may include a transmitter and / or receiver. Transceiver 206 may be used synonymously with RF unit. In this disclosure, device may also mean communication modem / circuit / chip.

[0030] The hardware elements of devices 100,200 are described in more detail below. However, one or more protocol layers may be embodied by one or more processors 102,202. For example, one or more processors 102,202 can embodied one or more layers (e.g., functional layers such as PHY and MAC). One or more processors 102,202 can generate one or more PDUs (Protocol Data Units) and / or one or more SDUs (Service Data Units) by means of the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams in this disclosure. One or more processors 102,202 can generate messages, control information, data, or information by means of the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams in this disclosure. One or more processors 102,202 can generate signals (e.g., baseband signals) containing PDUs, SDUs, messages, control information, data, or information by the functions, procedures, proposals and / or methods of this disclosure and provide them to one or more transceivers 106,206. One or more processors 102,202 can receive signals (e.g., baseband signals) from one or more transceivers 106,206 and obtain PDUs, SDUs, messages, control information, data, or information by the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams of this disclosure.

[0031] One or more processors 102,202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102,202 may be embodied 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, procedures, proposals, methods and / or operation sequence diagrams disclosed in this disclosure may be embodied using firmware or software, and the firmware or software may be embodied to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods and / or sequence diagrams disclosed in this disclosure may be contained in one or more processors 102,202 or stored in one or more memories 104,204 and driven by one or more processors 102,202. The descriptions, functions, procedures, suggestions, methods and / or sequence diagrams disclosed in this disclosure may be embodied by firmware or software in the form of code, instructions and / or sets of instructions.

[0032] One or more memories 104,204 may be connected to one or more processors 102,202 and can store various forms of data, signals, messages, information, programs, code, instructions and / or commands. One or more memories 104,204 may consist of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media and / or combinations thereof. One or more memories 104,204 may be located inside and / or outside of one or more processors 102,202. Furthermore, one or more memories 104,204 may be connected to one or more processors 102,202 by various technologies such as wired or wireless connections.

[0033] One or more transceivers 106,206 can transmit user data, control information, radio signals / channels, etc., as referred to in the methods and / or operation sequence diagrams of this disclosure, to one or more other devices. One or more transceivers 106,206 can receive user data, control information, radio signals / channels, etc., as referred to in the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams disclosed in this disclosure, from one or more other devices. For example, one or more transceivers 106,206 may be coupled with one or more processors 102,202 to transmit and receive radio signals. For example, one or more processors 102,202 can control one or more transceivers 106,206 to transmit user data, control information, or radio signals to one or more other devices. Also, one or more processors 102,202 can control one or more transceivers 106,206 to receive user data, control information, or radio signals from one or more other devices. Furthermore, 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 transmit and receive user data, control information, radio signals / channels, etc., as referred to in the descriptions, functions, procedures, proposals, methods and / or operation sequence diagrams disclosed in this disclosure, via one or more antennas 108,208. In this 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 the received user data, control information, radio signals / channels, etc., from RF band signals to baseband signals for processing using one or more processors 102,202. One or more transceivers 106,206 may convert the user data, control information, radio signals / channels, etc., processed by one or more processors 102,202, from baseband signals to RF band signals. To this end, one or more transceivers 106,206 may include (analog) oscillators and / or filters.

[0034] For example, either STA100 or STA200 can perform the intended operation of an AP, and the other STA100 or STA200 can perform the intended operation of a non-AP STA. For example, the transceivers 106 and 206 in Figure 1 can perform the transmission and reception of signals (e.g., packets or PPDUs (Physical Layer Protocol Data Units) conforming to IEEE 802.11a / b / g / n / ac / ax / be / bn, etc.). Furthermore, in this disclosure, the operation of various STAs generating transmission and reception signals or performing data processing and calculations in advance for transmission and reception signals may be performed by the processors 102 and 202 in Figure 1. For example, an example of an operation that generates transmit / receive signals or performs data processing or calculations in advance for transmit / receive signals may include: 1) an operation to determine / acquire / construct / calculate / decode / encode bit information of fields contained within the PPDU (SIG (signal), STF (short training field), LTF (long training field), Data, etc.); 2) an operation to determine / construct / acquire time resources and frequency resources (e.g., subcarrier resources) used for fields contained within the PPDU (SIG, STF, LTF, Data, etc.); 3) an operation to determine / construct / acquire specific sequences (e.g., pilot sequence, STF / LTF sequence, extra sequence applied to SIG) used for fields contained within the PPDU (SIG, STF, LTF, Data, etc.); 4) power control operations and / or power saving operations applied to the STA; and 5) operations related to determining / acquiring / constructing / calculating / decoding / encoding the ACK signal. Furthermore, in the following example, various pieces of information used by various STAs for determining / acquiring / composing / calculating / decoding / encoding the transmit / receive signals (e.g., information about fields / subfields / control fields / parameters / power, etc.) may be stored in memories 104,204 of Figure 1.

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

[0036] Figure 2 shows an exemplary structure of a wireless LAN system to which this disclosure can be applied.

[0037] The structure of a wireless LAN system may consist of multiple components. A wireless LAN may be provided that supports transparent STA mobility to higher layers through the interaction of multiple components. A BSS (Basic Service Set) corresponds to the basic structural block of a wireless LAN. Figure 2 illustrates the existence of two BSSs (BSS1 and BSS2), with each BSS containing two STAs as members (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). In Figure 2, the ellipses representing the BSSs may be understood as representing the coverage area where the STAs included in that BSS maintain communication. This area can be called a BSA (Basic Service Area). When an STA moves outside a BSA, it can no longer communicate directly with other STAs within that BSA.

[0038] Ignoring the DS shown in Figure 2, the most basic type of BSS in a wireless LAN is the Independent BSS (IBSS). For example, an IBSS can have a minimal form consisting of only two STAs. For instance, assuming other components are omitted, BSS1 consisting only of STA1 and STA2, or BSS2 consisting only of STA3 and STA4, can each be considered a typical example of an IBSS. Such a configuration is possible when STAs can communicate directly without APs. Furthermore, this type of wireless LAN is not pre-planned and configured, but can be configured when the LAN requires it, and can be called an ad-hoc network. Since an IBSS does not include APs, there is no centralized management entity. That is, in an IBSS, STAs are managed in a distributed manner. In an IBSS, all STAs may be mobile STAs, and connection to a distributed system (DS) is not permitted, forming a self-contained network.

[0039] STA membership in the BSS can change dynamically due to actions such as STAs being added or removed, or STAs entering or leaving the BSS area. To become a member of the BSS, an STA can join the BSS using a synchronization process. To access all services of the BSS-based structure, an STA must be associated with the BSS. Such associations may be configured dynamically and may include the use of Distribution System Services (DSS).

[0040] In a wireless LAN, the direct distance between STAs may be limited by the PHY performance. While this distance limit may be sufficient in some cases, there may be situations requiring communication between STAs over longer distances. Distributed systems (DS) may be configured to support extended coverage.

[0041] DS refers to a structure in which BSSs are interconnected. Specifically, as shown in Figure 2, BSSs may exist as components of an extended form of a network composed of multiple BSSs. DS is a logical concept and may be identified by the characteristics of the Distributed System Medium (DSM). In this regard, Wireless Medium (WM) and DSM may be logically distinct. Each logical medium is used for a different purpose and by different components. These mediums are neither limited to being the same nor limited to being different. The flexibility of wireless LAN structures (DS structures or other network structures) can be explained by the fact that multiple mediums are logically distinct from one another. That is, wireless LAN structures can be embodied in various ways, and each embodied example may be identified independently by its physical characteristics.

[0042] DS can support mobile devices by providing seamless integration of multiple BSSs and offering the necessary logical services for handling destination addresses. DS may also include a portal component that acts as a bridge for connecting wireless LANs with other networks (e.g., IEEE 802.X).

[0043] An AP (Application Programming Object) is an entity that enables a coupled non-AP STA (Systematization System) to access the DS (Data Storage System) via the WM (Web Module) and also possesses the functionality of an STA. Data can be moved between the BSS (Base System Storage) and the DS via the AP. For example, STA2 and STA3, shown in Figure 2, possess the functionality of an STA while also providing the ability for coupled non-AP STAs (STA1 and STA4) to access the DS. Furthermore, since all APs are essentially STAs, all APs are addressable entities. The address used by the AP for communication on the WM and the address used by the AP for communication on the DSM (Data Storage System) do not necessarily have to be the same. A BSS consisting of an AP and one or more STAs can be called an infrastructure BSS.

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

[0045] An Extended Service Set (ESS) may be added to the aforementioned DS structure to provide even broader coverage.

[0046] An ESS (Service Set Network) refers to a network of arbitrary size and complexity composed of DSs (Distributed Service Sets) and BSSs (Blockchain Service Sets). An ESS can be a collection of BSSs connected to a single DS. However, an ESS cannot contain a DS. A key feature of an ESS network is that it appears as an IBSS (Internet Link Control Service Set) at the LLC (Logical Link Control) layer. STAs (Stage Attacks) within an ESS can communicate with each other, and mobile STAs can move transparently to the LLC from one BSS to another (within the same ESS). APs (Access Points) within an ESS may have the same SSID (Service Set Identification). An SSID is distinct from a BSSID, which is the identifier for a BSS.

[0047] In wireless LAN systems, no assumptions are made regarding the relative physical location of BSSs, and any of the following forms are possible: BSSs may partially overlap, which is a commonly used form to provide continuous coverage. BSSs do not have to be physically connected, and logically there is no limit to the distance between BSSs. BSSs may also be located in the same physical location, which may be used to provide redundancy. One (or more) IBSS or ESS networks may physically exist in the same space as one (or more) ESS networks. This may include ESS network configurations when an ad hoc network operates in the 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 at the same location.

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

[0049] For an STA to set up a link to a network and send and receive data, it must first discover the network, perform authentication, establish an association, and carry out security authentication procedures. The link setup process can be called the session initiation process or session setup process. Alternatively, the discovery, authentication, association, and security setting processes of the link setup process can be collectively referred to as the association process.

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

[0051] There are two scanning methods: active scanning and passive scanning. Figure 3 illustrates a network discovery operation that includes the active scanning process. In active scanning, the STA performing the scanning sends a probe request frame to search for nearby APs while moving between channels, and waits for a response. The responder sends a probe response frame to the STA that 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 BSS, APs send beacon frames, so APs become the responders, while in IBSS, STAs within IBSS alternately send beacon frames, so the responders are not constant. For example, an STA that sends a probe request frame on channel 1 and receives a probe response frame on channel 1 can save the BSS-related information contained in the received probe response frame and move to the next channel (e.g., channel 2) to perform scanning in the same way (i.e., send and receive probe requests / responses on channel 2).

[0052] Although not shown in Figure 3, scanning may also be performed using a passive scanning method. In passive scanning, the STA performing the scanning waits for beacon frames while switching channels. A beacon frame is one of the management frames defined in IEEE 802.11, and is transmitted periodically to announce the presence of a wireless network, allowing the scanning STA to find and join the wireless network. In BSS, APs are responsible for periodically transmitting beacon frames, while in IBSS, STAs within IBSS transmit beacon frames alternately. When the scanning STA receives a beacon frame, it stores the BSS information contained in the beacon frame and records the beacon frame information on each channel while moving to other channels. An STA that has received a beacon frame can store the BSS-related information contained in the received beacon frame and move to the next channel to perform scanning on the next channel in the same way. Comparing active scanning and passive scanning, active scanning has the advantage of less delay and power consumption compared to passive scanning.

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

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

[0055] The authentication frame may include information such as the authentication algorithm number, authentication transaction sequence number, status code, challenge text, Robust Security Network (RSN), and Finite Cyclic Group. This is just an example of some of the information that may be included in the authentication request / response frame, and may be replaced by other information or may contain additional information.

[0056] The STA can send an authentication request frame to the AP. Based on the information contained in the received authentication request frame, the AP can decide whether or not to allow authentication to the STA. The AP can provide the STA with the result of the authentication process using an authentication response frame.

[0057] After the STA has been successfully authenticated, the association process may take place in step S330. The association process includes the STA sending an association request frame to the AP, and the AP sending an association response frame to the STA in response.

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

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

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

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

[0062] In wireless LAN systems, the basic access mechanism of MAC (Medium Access Control) is the CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) mechanism. The CSMA / CA mechanism is also called the Distributed Coordination Function (DCF) of IEEE 802.11 MAC, and basically employs a "listen before talk" access mechanism. With this type of access mechanism, an AP and / or STA can perform a Clear Channel Assessment (CCA) to sense the radio channel or medium within a predetermined time interval (e.g., DIFS Inter-Frame Space) before initiating transmission. If the sensing determines that the medium is idle, the AP and / or STA will begin transmitting a frame through that medium. On the other hand, if the medium is perceived as occupied or busy, the AP and / or STA will not begin transmitting itself, but will wait for a delay period (e.g., a random backoff period) for medium access before attempting to transmit a frame. By applying a random backoff period, multiple STAs are expected to attempt to transmit frames after waiting for different periods of time from each other, thus minimizing collisions.

[0063] Furthermore, the IEEE 802.11 MAC protocol provides HCF (Hybrid Coordination Function). HCF is based on the aforementioned DCF and PCF (Point Coordination Function). PCF is a polling-based synchronous access method that periodically polls so that all receiving APs and / or STAs can receive data frames. HCF also has EDCA (Enhanced Distributed Channel Access) and HCCA (HCF Controlled Channel Access). EDCA is a competition-based access method for a provider to provide data frames to multiple users, while HCCA uses a non-competition-based channel access method with a polling mechanism. In addition, HCF includes a media access mechanism to improve the QoS (Quality of Service) of wireless LANs and can transmit QoS data during both the Contention Period (CP) and the Contention Free Period (CFP).

[0064] Refer to Figure 4 to explain the operation based on the random backoff period. When a medium that was occupied / busy changes to idle, multiple STAs can attempt to transmit data (or frames). As a way to minimize collisions, each STA can select a random backoff count and wait for the corresponding slot time before attempting to transmit. The random backoff count has a pseudo-random integer value and may be determined to any one of the values ​​in the range of 0 to CW, where CW is the Contention Window parameter value. The CW parameter is initially given as CWmin, but can take twice that value in case of transmission failure (e.g., if an ACK for a transmitted frame is not received). When the CW parameter value becomes CWmax, the STA can attempt to transmit data while maintaining the CWmax value until successful data transmission occurs, at which point it is reset to the CWmin value. The CW, CWmin, and CWmax values ​​are 2 n It is preferable to set it to -1 (n=0,1,2,...).

[0065] Once the random backoff process begins, the STA continues to monitor the media while counting down the backoff slots according to the determined backoff count value. When the media is monitored as occupied, the countdown stops and it waits; when the media becomes idle, the remaining countdown resumes.

[0066] In the example in Figure 4, when a packet to be transmitted reaches the MAC of STA3, STA3 can immediately transmit the frame after confirming that the medium is idle for DIFS only. The remaining STAs monitor the occupied / busy state of the medium and wait. Meanwhile, data to be transmitted may also be generated in STA1, STA2, and STA5. When each STA monitors the medium as idle, after waiting for DIFS only, it can count down the backoff slot using a random backoff count value of its choice. Assume that STA2 selects the minimum backoff count value and STA1 selects the maximum backoff count value. That is, the example illustrates a case where the remaining backoff time for STA5 is shorter than the remaining backoff time for STA1 when STA2 finishes its backoff count and begins transmitting a frame. STA1 and STA5 pause their countdown and wait for a while while STA2 occupies the medium. When STA2's occupation ends and the medium becomes idle again, STA1 and STA5 wait for DIFS only before resuming the paused backoff count. In other words, frame transmission can begin after counting down the remaining backoff slots equal to the remaining backoff time. Since STA5's remaining backoff time was shorter than STA1's, STA5 begins frame transmission. Data to transmit may also occur in STA4 while STA2 is occupying the medium. From STA4's perspective, when the medium becomes idle, it can wait for DIFS, then count down using a random backoff count value of its choosing, and begin frame transmission. The example in Figure 4 shows a case where STA5's remaining backoff time coincidentally matches STA4's random backoff count value, in which case a collision may occur between STA4 and STA5. If a collision occurs, neither STA4 nor STA5 will receive an ACK, and data transmission will fail. In this case, STA4 and STA5 can double their CW value, select a random backoff count value, and then perform the countdown.STA1 waits while the medium is occupied by transmissions from STA4 and STA5. When the medium becomes idle, STA1 waits only for DIFS time, and can start transmitting frames once the remaining backoff time has elapsed.

[0067] As illustrated in Figure 4, data frames are used to transmit data forwarded to higher layers and may be transmitted after a backoff that occurs after DIFS has elapsed, from the time the medium becomes idle. Furthermore, management frames are used to exchange management information that is not forwarded to higher layers and are transmitted after a backoff that occurs after an IFS such as DIFS or PIFS (Point Coordination Function IFS) has elapsed. Subtypes of management frames include beacons, association request / response, re-association request / response, probe request / response, and authentication request / response. Control frames are used to control access to the medium. Subtypes of control frames include RTS (Request-To-Send), CTS (Clear-To-Send), ACK (Acknowledgment), PS-Poll (Power Save-Poll), Block ACK (BlockAck), Block ACK Request (BlockACKReq), NDP Announcement (null data packet announcement), and Trigger. If a control frame is not a response frame to a previous frame, it is sent after a backoff that occurs after DIFS (Distributed Ingress Fault System), and if it is a response frame to a previous frame, it is sent after a short IFS (Shorter Ingress Fault System) without a backoff. The type and subtype of a frame may be identified by the type field and subtype field in the frame control (FC) field.

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

[0069] Figure 5 is a diagram illustrating the CSMA / CA baseframe transmission operation to which this disclosure can be applied.

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

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

[0072] In CSMA / CA baseframe transmission operation, a mechanism utilizing RTS / CTS frames may be applied to reduce the possibility of collisions between transmissions from multiple STAs. In the example in Figure 5, while STA1 is transmitting, carrier sensing by STA3 may determine that the medium is idle. That is, STA1 may be a hidden node for STA3. Alternatively, in the example in Figure 5, while STA2 is transmitting, carrier sensing by STA3 may determine that the medium is idle. That is, STA2 may be a hidden node for STA3. By exchanging RTS / CTS frames before data transmission and reception between STA1 and STA2, it is possible to prevent STAs outside the transmission range of either STA1 or STA2, or STAs outside the carrier sensing range for transmissions from STA1 or STA3, from attempting to occupy the channel during data transmission and reception between STA1 and STA2.

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

[0074] STA1 can send an RTS frame to STA2 after backoff if the channel is idle during DIFS. STA2, upon receiving an RTS frame, can send a CTS frame, which is a response to the RTS frame, to STA1 after SIFS.

[0075] If STA3 cannot overhear CTS frames from STA2 but can overhear RTS frames from STA1, STA3 can use the duration information contained in the RTS frames to set the NAV timer for subsequent consecutive frame transmission periods (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame). Alternatively, if STA3 cannot overhear RTS frames from STA1 but can overhear CTS frames from STA2, STA3 can use the duration information contained in the CTS frames to set the NAV timer for subsequent consecutive frame transmission periods (e.g., SIFS + data frame + SIFS + ACK frame). In other words, STA3 can set NAV based on overhearing one or more RTS or CTS frames from at least one of STA1 or STA2. If STA3 receives a new frame before the NAV timer expires, it can update the NAV timer using the duration information contained in the new frame. STA3 will not attempt to access the channel until the NAV timer expires.

[0076] When STA1 receives a CTS frame from STA2, it can send a data frame to STA2 after SIFS from the time the CTS frame reception is complete. If STA2 successfully receives the data frame, it can send an ACK frame, which is a response to the data frame, to STA1 after SIFS. When the NAV timer expires, STA3 can use carrier sensing to determine whether the channel is in use or not. If STA3 determines that the channel is not being used by another terminal between the expiration of the NAV timer and DIFS, it can attempt to access the channel after the random backoff conflict window (CW) has passed.

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

[0078] The PHY layer can prepare the MPDU (MAC PDU) to be transmitted based on instructions or primitives (meaning a set of instructions or parameters) from the MAC layer. For example, when the PHY layer receives an instruction from the MAC layer requesting it to start transmitting, it switches to transmit mode and can assemble the information provided by the MAC layer (e.g., data) into a frame and transmit it. Also, when the PHY layer detects a valid preamble in the frame it is receiving, it monitors the preamble header and sends an instruction to the MAC layer to signal that the PHY layer has started receiving.

[0079] Thus, information transmission and reception in wireless LAN systems are performed in the form of frames, and for this purpose, the Physical Layer Protocol Data Unit (PPDU) frame format is defined.

[0080] A basic PPDU may include an STF (Short Training Field), an LTF (Long Training Field), a SIG (SIGNAL) field, and a Data field. The most basic (e.g., non-HT (High Throughput) PPDU format shown in Figure 7) may consist only of an L-STF (Legacy-STF), an L-LTF (Legacy-LTF), an L-SIG (Legacy-SIG) field, and a Data field. 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 other types of) RL-SIG, U-SIG, non-legacy SIG fields, non-legacy STF, non-legacy LTF (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)) may be included between the L-SIG field and the Data field. More specific details will be discussed later, referring to Figure 7.

[0081] STF is a signal used for signal detection, AGC (Automatic Gain Control), diversity selection, and precise time synchronization, while LTF is a signal used for channel estimation and frequency error estimation. In essence, STF and LTF are signals for synchronizing the OFDM physical layer and for channel estimation.

[0082] The SIG field may contain various information related to PPDU transmission and reception. For example, the L-SIG field consists of 24 bits and 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 contain information about the data modulation and coding rate. For example, the 12-bit Length field may contain information about the length or time duration of the PPDU. For example, the value of the 12-bit Length field may be determined based on the type of PPDU. For example, for non-HT, HT, VHT, or EHT PPDUs, the value of the Length field may be determined to be a multiple of 3. For example, for HE PPDUs, the value of the Length field may be determined to be a multiple of 3 + 1 or a multiple of 3 + 2.

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

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

[0085] The MAC header includes fields such as Frame Control, Duration / ID, and Address. The Frame Control field may contain control information necessary for transmitting / receiving frames. The Duration / ID field may be set to the time required to transmit the frame. The Address subfield can indicate the frame's receiver address, transmitter address, destination address, and source address, and some Address subfields may be omitted. Sequence Control, QoS Control, and HT Control subfields are also included, and the specific contents of each subfield of the MAC header can be found in the IEEE 802.11 standard document.

[0086] The null data PPDU (NDP) format refers to a form of PPDU format that does not include data fields. In other words, NDP is a frame format that includes the PPDU preamble (i.e., L-STF, L-LTF, L-SIG fields, and if present, also non-legacy SIG, non-legacy STF, and non-legacy LTF fields) in a general PPDU format, but does not include the rest (i.e., data fields).

[0087] Figure 7 shows an example of a PPDU as defined in the IEEE 802.11 standard to which this disclosure applies.

[0088] Standards such as IEEE 802.11a / g / n / ac / ax use various forms of PPDU. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and Data fields. The basic PPDU format can also be referred to as the non-HT PPDU format (Figure 7(a)).

[0089] The HT PPDU format (IEEE 802.11n) further includes the HT-SIG, HT-STF, and HT-LFT(s) fields in addition to the basic PPDU format. The HT PPDU format shown in Figure 7(b) can be referred to as the HT-mixed format. The HT-greenfield format PPDU may be further defined, which does not include L-STF, L-LTF, and L-SIG, and consists of the HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTF, and Data fields (not shown).

[0090] An example of the VHT PPDU format (IEEE 802.11ac) further includes the VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields in addition to the basic PPDU format (Figure 7(c)).

[0091] An example of the HE PPDU format (IEEE 802.11ax) further includes the RL-SIG (Repeated L-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), and PE (Packet Extension) fields in addition to the basic PPDU format (Figure 7(d)). Depending on the specific example of the HE PPDU format, some fields may be omitted or their lengths may change. For example, the HE-SIG-B field is included in the HE PPDU format for multiple users (MU), but not in the HE PPDU format for single users (SU). Also, the HE trigger-based (TB) PPDU format does not include HE-SIG-B, and the length of the HE-STF field may be changed to 8us. The HE ER (Extended Range) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may be changed to 16us. For example, RL-SIG may be configured identically to L-SIG. Based on the presence of RL-SIG, the receiving STA can determine that the received PPDU is either an HE PPDU or an EHT PPDU, as described later.

[0092] The EHT PPDU format may include the EHT MU (multi-user) format shown in Figure 7(e) and the EHT TB (trigger-based) PPDU format shown in Figure 7(f). The EHT PPDU format is similar to the HE PPDU format in that it includes an RL-SIG following the L-SIG, but it may also include a U (universal)-SIG, EHT-SIG, EHT-STF, and EHT-LTF following the RL-SIG.

[0093] The EHT MU PPDU in Figure 7(e) corresponds to a carry PPDU that carries one or more data (or PSDUs) for one or more users. In other words, the EHT MU PPDU may be used for either SU transmission or MU transmission. For example, the EHT MU PPDU may correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0094] The EHT TB PPDU in Figure 7(f) omits the EHT-SIG compared to the EHT MU PPDU. An STA that receives a trigger for UL MU transmission (e.g., a trigger frame or TRS (triggered response scheduling)) can perform UL transmission based on the EHT TB PPDU format.

[0095] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal SIGNAL), and EHT-SIG fields may be encoded and modulated so that they can be attempted to be demodulated and decoded even by legacy STAs, and may be mapped based on a defined subcarrier frequency interval (e.g., 312.5 kHz). These may be referred to as pre-EHT modulated fields. Next, the EHT-STF, EHT-LTF, Data, and PE fields may be encoded and modulated so that they can be demodulated and decoded by STAs that have successfully decoded non-legacy SIGs (e.g., U-SIG and / or EHT-SIG) and obtained the information contained in those fields, and may be mapped based on a defined subcarrier frequency interval (e.g., 78.125 kHz). These may be referred to as EHT modulated fields.

[0096] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields can be referred to as pre-HE modulated fields, while the HE-STF, HE-LTF, Data, and PE fields can be referred to as HE modulated fields. Furthermore, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields can be referred to as pre-VHT modulated fields, while the VHT STF, VHT-LTF, VHT-SIG-B, and Data fields can be referred to as VHT modulated fields.

[0097] The U-SIG included in the EHT PPDU format in Figure 7 may be composed of, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol for the U-SIG (e.g., an OFDM symbol) may have a duration of 4us, and the U-SIG may have a total duration of 8us. Each symbol of the U-SIG may be used to transmit 26 bits of information. For example, each symbol of the U-SIG may be transmitted and received based on 52 data tones and 4 pilot tones.

[0098] U-SIGs may be configured in 20MHz units. For example, when an 80MHz PPDU is configured, identical U-SIGs may be duplicated in 20MHz units. That is, an 80MHz PPDU may contain four identical U-SIGs. When the bandwidth exceeds 80MHz, for example, for a 160MHz PPDU, the first 80MHz U-SIG and the second 80MHz U-SIG may be different from each other.

[0099] In a U-SIG, for example, A uncoded bits may be transmitted, and the first U-SIG symbol (e.g., U-SIG-1 symbol) may transmit the first X bits of the total A bits, while the second U-SIG symbol (e.g., U-SIG-2 symbol) may transmit the remaining Y bits of the total A bits. The A bits (e.g., 52 uncoded bits) may include a CRC field (e.g., a 4-bit field) and a tail field (e.g., a 6-bit field). The tail field may be used to terminate the trellis of the convolution decoder and may be set to 0, for example.

[0100] The A bit information transmitted by U-SIG can be distinguished into version-independent bits and version-dependent bits. For example, a new PPDU format not shown in Figure 7 (e.g., UHR PPDU format) may include U-SIG, and the format of the U-SIG field in the EHT PPDU format and the format of the U-SIG field in the UHR PPDU format may be the same, while the version-independent bits may differ in some or all respects.

[0101] For example, the size of the version-independent bits of a U-SIG may be fixed or variable. The version-independent bits may be assigned only to U-SIG-1 symbols, or to both U-SIG-1 and U-SIG-2 symbols. Version-independent and version-dependent bits may be referred to by various names, such as the first control bit and the second control bit.

[0102] For example, the version-independent bits of the U-SIG may include a 3-bit physical layer version identifier (PHY version identifier), which can indicate the PHY version of the transmitted and received PPDUs (e.g., EHT, UHR, etc.). 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 relates to UL communication, and the second value relates to DL communication. The version-independent bits of the U-SIG may also include information about the length of the TXOP (transmission opportunity) and information about the BSS color ID.

[0103] For example, the version-dependent bits of the U-SIG may include information that directly or indirectly indicates the type of PPDU (e.g., SU PPDU, MU PPDU, TB PPDU, etc.).

[0104] The U-SIG may include information necessary for transmitting and receiving PPDUs. For example, the U-SIG may further include information about bandwidth, information about the MCS technique applied to non-legacy SIGs (e.g., EHT-SIG or UHR-SIG), information indicating whether a dual carrier modulation (DCM) technique (e.g., a technique for reusing the same signal on two subcarriers to achieve an effect similar to frequency diversity) 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 bandwidth.

[0105] Some of the information necessary for sending and receiving PPDUs may be included in the U-SIG and / or non-legacy SIGs (e.g., EHT-SIG or UHR-SIG). For example, information regarding the type of non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF), information regarding the length and cyclic prefix (CP) length of non-legacy LTFs, information regarding the guard interval (GI) applicable to non-legacy LTFs, information regarding preamble puncturing applicable to PPDUs, and information regarding resource unit (RU) allocation may be included only in the U-SIG, only in the non-legacy SIG, or indicated by a combination of information included in the U-SIG and information included in the non-legacy SIG.

[0106] Preamble puncturing can mean the transmission of a PPDU in which one or more frequency units within the PPDU's bandwidth are not present. For example, the size of the frequency units (or the resolution of preamble puncturing) may be defined as 20 MHz, 40 MHz, etc. For example, preamble puncturing may be applied to PPDU bandwidths of a certain size or larger.

[0107] In the example shown in Figure 7, non-legacy SIGs such as HE-SIG-B and EHT-SIG may contain control information for the receiving STA. Non-legacy SIGs may be transmitted with at least one symbol, which may have a length of 4us. Information regarding the number of symbols used for the EHT-SIG may be included in a previous SIG (e.g., HE-SIG-A, U-SIG, etc.).

[0108] Non-legacy SIGs such as HE-SIG-B and EHT-SIG may include common fields and user-specific fields. Common fields and user-specific fields may be coded separately.

[0109] In some cases, the common field may be omitted. For example, in a compressed mode where non-OFDMA (orthogonal frequency multiple access) is applied, the common field may be omitted, and multiple STAs can receive the PPDU (e.g., the data field of the PPDU) in the same frequency band. In an uncompressed mode where OFDMA is applied, multiple users can receive the PPDU (e.g., the data field of the PPDU) in separate frequency bands.

[0110] The number of user-specific fields may be determined based on the number of users. A single user block field may contain a maximum of two user fields. Each user field may be associated with either MU-MIMO or non-MU-MIMO assignments.

[0111] The common field may include a CRC bit and a Tail bit, 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 location of RUs to which multiple users (i.e., multiple receiving STAs) are assigned.

[0112] A RU may contain multiple subcarriers (or tones). RUs may be used when transmitting signals to multiple STAs based on the OFDMA method. Alternatively, a RU may be defined when transmitting a signal to a single STA. Resources may be allocated on a RU basis for non-legacy STFs, non-legacy LTFs, and Data fields.

[0113] The applicable size of RUs may be defined by the PPDU bandwidth. RUs may be defined to be identical or different for the applicable PPDU format (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.). For example, for an 80MHz PPDU, the RU arrangement for HE PPDU and EHT PPDU may differ from each other. The applicable RU size, number of RUs, RU locations, DC (direct current) subcarrier locations and number, null subcarrier locations and number, guard subcarrier locations and number, etc., for each PPDU bandwidth can be called a tone plan. For example, a tone plan for a wide bandwidth may be defined as multiple iterations of a low-bandwidth tone plan.

[0114] 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, 4×996-tone RUs, etc. An MRU (multiple RU) is distinct from multiple individual RUs and corresponds to a group of subcarriers composed 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. Furthermore, the multiple RUs that make up a single MRU may or may not be consecutive in the frequency domain.

[0115] The specific size of a RU may be reduced or expanded. Therefore, the specific size of each RU (i.e., the number of corresponding tones) in this disclosure is illustrative and not restrictive. Also, in this disclosure, the number of RUs within a given bandwidth (e.g., 20, 40, 80, 160, 320 MHz, ...) may vary depending on the size of the RU.

[0116] In the PPDU format shown in Figure 7, the names of the fields are illustrative and do not limit the scope of this disclosure. Furthermore, the examples in this disclosure may apply not only to the PPDU format illustrated in Figure 7, but also to new PPDU formats that are based on the PPDU format in Figure 7 but with some fields excluded and / or some fields added.

[0117] Wireless LAN sensing procedure

[0118] The WLAN sensing procedure (hereinafter referred to as the sensing procedure) refers to the procedure for acquiring perceptual information about the surrounding environment based on information about the channel environment (or state) contained in the signal transmitted from the transmitting end to the receiving end. Each STA can provide value-added services that can be applied in various forms to real life based on the information about the surrounding environment acquired by the sensing procedure.

[0119] Here, information about the surrounding environment may include, for example, gesture recognition information, fall detection information, intrusion detection information, user motion detection, health monitoring information, or pet movement detection.

[0120] The sensing procedure may be initiated by a sensing initiator. A sensing initiator means an STA that uses a (WLAN) signal to instruct one or more STAs with sensing capabilities to initiate a sensing session.

[0121] For example, a sensing initiator can send a sensing signal (e.g., a PPDU for sensing measurement) to one or more STAs that have sensing capabilities, or send a frame requesting them to send a sensing signal.

[0122] A sensing session refers to a time period (or instance) in which a series of sensing procedures are performed. That is, a sensing session refers to a time period (or instance) in which various protocols related to the transmission and reception of sensing signals are exchanged, or an instance of a sensing procedure having associated operational parameters. Sensing sessions may be assigned to an STA periodically or, if necessary, aperiodically.

[0123] A sensing session may consist of a (sensing) setup phase, a (sensing) measurement setup phase, a (sensing measurement instance) phase, a reporting phase, a termination phase, etc. The negotiation phase (or process) for determining the operating parameters may be configured as a sub-phase of the setup phase (i.e., a part of the setup phase) or independently of the setup phase.

[0124] Furthermore, a sensing session may consist of multiple sub-sessions, each of which may include a measurement phase and a reporting phase. Here, a sub-session may be referred to as a sensing burst, measurement instance, or measurement burst.

[0125] A sensing responder is an STA that has joined a sensing session initiated by a sensing initiator. The sensing responder can send results obtained by performing sensing operations (e.g., channel status information) to the sensing initiator, or send sensing signals to the sensing initiator as instructed by the sensing initiator.

[0126] A sensing transmitter refers to an STA that transmits signals for sensing (e.g., a PPDU for sensing measurement) during a sensing session (or burst). A sensing receiver refers to an STA that receives signals for sensing during a sensing session (or burst).

[0127] When a sensing session consists of multiple sensing bursts, the sensing sender / receiver within the overall sensing burst may be the same, but is not limited to this. The sensing senders / receivers within some of the sensing bursts may be different from each other, and the sensing sender / receiver may change with each sensing burst.

[0128] Within a sensing session, the sensing initiator can act as either a sensing sender or a sensing receiver, and the sensing responder can act as either a sensing receiver or a sensing sender.

[0129] Furthermore, during each sensing burst that constitutes a sensing session, the sensing transmitter may transmit a signal for sensing and the sensing receiver may transmit feedback. As yet another example, during each sensing burst, only the sensing transmitter may transmit a signal for sensing.

[0130] Each sensing burst may be defined as continuous in time, but not limited to this, and may also be defined as discontinuous in time. When each sensing burst is defined as discontinuous in time, it may be defined identically or similarly to a TXOP (transmission opportunity), where TXOP means a time interval in which a particular STA may have the right to initiate a frame exchange sequence on a wireless medium (WM).

[0131] Explicit sensing may include the process of a sensing transmitter transmitting a sensing signal and a sensing responder providing feedback. Implicit sensing includes the operation of extracting information using a sensing transmission by a sensing transmitter, and the feedback process may be omitted.

[0132] A wireless LAN SBP (sensing by proxy) initiator can mean a non-AP STA that requests sensing from an AP STA as needed or periodically. An SBP initiator can participate as a responder in (cooperative) sensing procedures managed by the AP. In terms of transmitting and receiving signals for sensing, an SBP initiator can participate in the (cooperative) sensing procedure as a sensing transmitter, sensing receiver, sensing transmitter, and sensing receiver, etc.

[0133] This disclosure assumes that the SBP initiator participates in the (cooperative) sensing procedure as a sensing sender or sensing receiver.

[0134] For example, if an SBP initiator (i.e., a specific non-AP STA) requests a (cooperative) sensing procedure from an AP (i.e., requests an SBP) but does not participate in said (cooperative) sensing procedure, the AP may perform the (cooperative) sensing procedure with other non-AP STA(s) around the specific non-AP STA. In this case, if the other non-AP STA(s) transmit a sensing signal (e.g., a SU (single user) NDP), the SBP initiator may also receive said sensing signal.

[0135] As another example, when Physical Layer Security is applied (for example, when Secure LTF is applied in an IEEE 802.11az-based wireless LAN system), the AP can share prior information with the SBP initiator for decoding the sensing signal.

[0136] As another example, an AP can perform (cooperative) sensing with STAs around the SBP initiator and transmit the (cooperative) sensing results to the SBP initiator using SBP-related frames (e.g., SBP response frames).

[0137] Collaborative sensing procedure based on the SBP procedure

[0138] There may be situations where a specific Non-AP STA finds it difficult or unacceptable to perform a direct sensing procedure with surrounding non-AP STAs. For this reason, a specific non-AP STA may request a sensing procedure from an AP (i.e., request an SBP), and the AP may perform a (cooperative) sensing procedure with one or more non-AP STAs.

[0139] The following describes how one or more non-AP STAs and APs can perform a collaborative sensing procedure based on the SBP procedure.

[0140] Figure 8 is a diagram illustrating the operation performed by a first STA according to one embodiment of the present disclosure. In Figures 8 and 9, the first STA can mean a non-AP STA that is an SBP initiator (or sensing responder), and the second STA can mean an AP that is an SBP responder (or sensing initiator).

[0141] Furthermore, a (collaborative) sensing procedure between at least one sensing responder will be referred to as an SR2SR sounding procedure. That is, a (collaborative) sensing procedure initiated by an SBP procedure in which at least one sensing responder (or non-AP STA) participates may be referred to as an SR2SR sounding procedure. However, in one embodiment of this disclosure, an AP may also participate in the sensing measurement process based on the SBP procedure.

[0142] The first STA can send a first frame to the second STA to request the SBP (sensing by proxy) procedure (S810).

[0143] In other words, the first STA can send a first frame (e.g., an SBP request frame) to the second STA to request the sensing measurement procedure as the SBP initiator.

[0144] As an example, the first frame may include first information related to the SR2SR (sensing responder to sensing responder) sounding procedure, and second information indicating whether or not the first STA participates in the SR2SR sounding procedure.

[0145] Specifically, the first information may be indicated by a field requesting an SR2SR sounding procedure with at least one sensing responder (e.g., an SR2SR sounding request field).

[0146] The second piece of information may be indicated by a sensing responder field included in the first frame. For example, based on a sensing responder field value being set to 1, the second piece of information may indicate that the first STA will participate in the SR2SR sounding procedure. As yet another example, based on a sensing responder field value being set to 0, the second piece of information may indicate that the first STA will not participate in the SR2SR sounding procedure.

[0147] Furthermore, the first frame may include at least one of the following: the number of at least one sensing responder participating in the SR2SR sounding procedure; the ID (identity) information of at least one sensing responder (e.g., MAC address / ID, AID / USID (unassociated STA identifier)); or information related to the role of at least one sensing responder.

[0148] Here, information relating to the number of at least one sensing responder participating in the SR2SR sounding procedure may include the number of sensing responders requested to participate in the SR2SR sounding procedure, the number of sensing responders required to participate in the SR2SR sounding procedure, and so on.

[0149] Information relating to the role of at least one sensing responder may be indicated by a sensing responder role bitmap field. The role of at least one sensing responder may be one of i) sensing sender, ii) sensing receiver, or iii) sensing sender and sensing receiver.

[0150] In other words, the roles of at least the first STA and at least one sensing responder participating in the SR2SR sounding procedure may be set by the bitmap field to one of i) sensing sender, ii) sensing receiver, or iii) sensing sender and sensing receiver.

[0151] The first STA can receive the second frame in response to the first frame from the second STA (S820).

[0152] Here, the second frame (e.g., the SBP response frame) may include a response to the SBP procedure request (e.g., a response accepting or rejecting the SBP procedure request or requesting modifications to the detailed settings). Based on accepting or modifying the SBP procedure request, the second frame may include information related to the SBP procedure.

[0153] As an example of this disclosure, based on the second information indicating that the first STA is to participate in the SR2SR sounding procedure, the first STA may receive a first trigger frame or a sensing NDP (null data physical layer protocol data unit) announcement frame related to the SR2SR sounding procedure from the second STA.

[0154] We then assume that the role of the first STA (in a particular sensing session / instance / burst within the SR2SR sensing procedure) is that of a sensing transmitter. The first STA can transmit a sensing signal based on a first trigger frame (e.g., a sensing trigger frame set in the SR2SR sounding variant) or a sensing NDP known frame to at least one sensing responder participating in the SR2SR sounding procedure (i.e., a sensing responder acting as a sensing receiver).

[0155] Here, the sensing signals transmitted in the SR2SR sounding procedure may include SU (single user) NDP.

[0156] A fourth frame (for example, a second (sensing) trigger frame set to the sensing reporting variant) requesting the reporting of channel information acquired based on the sensing signal may be sent from the second STA to at least one sensing responder. Based on the fourth frame, channel information may be sent from at least one sensing responder to the second STA.

[0157] Based on the first frame, the first STA can receive a third frame from the second STA related to the sensing measurement report (related to the SR2SR sounding procedure) (S830).

[0158] Here, the third frame (for example, the SBP report frame) may include at least one of the following: channel information acquired by the sensing responder using the sensing signal, a measurement session ID associated with the channel information, or the ID of the sensing responder who acquired the channel information. At least one of the following—channel information acquired using the sensing signal, a measurement session ID associated with the channel information, or the ID of the sensing responder who acquired the channel information—may be included in the fields related to the sensing measurement report.

[0159] The procedure for transmitting the third frame may be initiated after SIFS, when the (final) TB (trigger-based) sensing procedure corresponding to the sensing measurement session initiated by the second STA has been performed.

[0160] The method performed by the first STA, as illustrated in Figure 8, may also be performed by the first device 100 in Figure 1. For example, one or more processors 102 of the first device 100 in Figure 1 may be configured to send a first frame requesting the SBP procedure to the second STA via one or more transceivers 106. One or more processors 102 may be configured to receive a second frame in response to the first frame from the second STA via one or more transceivers 106. One or more processors 102 may be configured to receive a third frame related to the sensing measurement report from the second STA via one or more transceivers 106 based on the first frame.

[0161] Furthermore, one or more memories 104 of the first device 100 can store instructions for performing the method described in the example in Figure 8 when executed by one or more processors 102.

[0162] Figure 9 is a diagram illustrating the operation performed by the second STA according to one embodiment of the present disclosure.

[0163] The second STA can receive the first frame from the first STA to request the SBP procedure (S910).

[0164] Based on receiving the first frame, the second STA can decide whether to accept or reject the SBP procedure, or whether to modify the detailed settings related to the SBP procedure. The structure of the first frame is explained with reference to Figure 8, and a redundant explanation is omitted here.

[0165] The second STA can send a second frame in response to the first frame to the first STA (S920).

[0166] In other words, the second STA can transmit information to the first STA via the second frame regarding whether to accept or reject the SBP procedure, or whether to modify the detailed settings related to the SBP procedure.

[0167] If it is decided to accept the SBP procedure or modify the detailed settings, the second STA may send a first trigger frame (i.e., a trigger frame to trigger the SR2SR sounding procedure) to at least one STA participating in the SR2SR sounding procedure (e.g., the first STA and / or at least one non-AP STA participating in the SR2SR sounding procedure).

[0168] The second STA may send a fourth frame (e.g., a second trigger frame) requesting channel information to a specific sensing responder (i.e., a sensing responder acting as a sensing receiver) among at least one sensing responder. The second STA may receive channel information based on the fourth frame from the specific sensing responder.

[0169] The second STA may transmit a third frame related to the sensing measurement report to the first STA based on the first frame (S930). The third frame may include at least one of the following: channel information acquired by the sensing responder based on the sensing signal, a measurement session ID related to the channel information, or the ID of the sensing responder who acquired the channel information.

[0170] The method performed by the second STA, as illustrated in Figure 9, may also be performed by the second device 200 in Figure 1. For example, one or more processors 202 of the second device 200 in Figure 1 may be configured to receive a first frame requesting the SBP procedure from the first STA via one or more transceivers 106. One or more processors 202 may be configured to send a second frame in response to the first frame to the first STA via one or more transceivers 206. One or more processors 202 may be configured to send a third frame related to the sensing measurement report to the first STA via one or more transceivers 206 based on the first frame.

[0171] Furthermore, one or more memories 204 of the second device 200 can store instructions for performing the method described in the example in Figure 9 when executed by one or more processors 202.

[0172] The following section provides a detailed explanation of the collaborative sensing procedure based on the SBP procedure.

[0173] Example 1

[0174] Example 1 relates to the detailed process of a collaborative sensing procedure based on the SBP procedure. The collaborative sensing procedure may consist of phases 1, 2, and 3. Phase 1 may include an SBP request phase and a group formation phase, phase 2 may include a sounding phase, and phase 3 may include an SBP response phase.

[0175] An SBP initiator can participate in a (cooperative) sensing procedure as a sensing responder. In a (cooperative) sensing procedure, an SBP initiator can play the role of a sensing sender, a sensing receiver, or both. An SBP initiator can perform non-AP sensing via an AP through the SBP procedure.

[0176] Example 1-1

[0177] Example 1-1 relates to the operation of AP and / or non-AP STA during the SBP request stage.

[0178] Among non-AP STAs with wireless LAN sensing capacity, certain non-AP STAs with SBP-related capacity can request SBP from APs that support SBP. In other words, certain non-AP STAs can send an SBP request frame to the AP to request the sensing procedure.

[0179] Here, the AP can transmit information to non-AP STAs regarding whether or not it supports SBP using beacon frames, probe response frames, (re)association response frames, etc. Then, one or more non-AP STAs with sensing capability that support SBP can transmit information to the AP regarding whether or not it supports SBP using probe request frames, (re)association request frames.

[0180] As an example of this disclosure, an SBP request frame may include at least one of the following: i) the reason for requesting SBP (i.e., the reason for requesting the sensing procedure), ii) whether the non-AP STA requesting SBP will participate in the (cooperative) sensing procedure as a sensing responder, iii) the number of non-AP STAs participating in the (cooperative) sensing procedure using SBP, iv) information on the role of the non-AP STA requesting SBP in the sensing procedure when participating in the (cooperative) sensing procedure, v) the roles of one or more STAs participating in the (cooperative) sensing procedure, vi) location information of the non-AP STA requesting SBP, or vii) information on the peripheral devices of the non-AP STA requesting SBP.

[0181] For example, i) the reason for requesting SBP may include the intention to acquire channel information between surrounding STAs using (cooperative) sensing.

[0182] iii) The number of non-AP STAs participating in a (collaborative) sensing procedure using SBP may include the SBP initiator (i.e., the non-AP STA requesting SBP).

[0183] iv) When a non-AP STA requests an SBP to participate in a (cooperative) sensing procedure, the role information in the sensing procedure may include the sensing sender, the sensing receiver, or both the sensing sender and the sensing receiver.

[0184] v) (Cooperation) The roles of one or more STAs participating in the sensing procedure may be transmitted in bitmap format, and one or more STAs may include an SBP initiator.

[0185] vii) Information about one or more STAs located around a non-AP STA requesting an SBP may include ID information of those one or more STAs (e.g., MAC ID, AID, etc.).

[0186] Examples 1-2

[0187] Examples 1-2 relate to the operation of AP and / or non-AP STA during the group formation stage.

[0188] If one or more STAs with wireless LAN sensing capacity exist around the SBP initiator, the central entity (e.g., AP) can group one or more STAs together. In this case, the SBP initiator can also be included as a sensing responder in the group containing one or more STAs.

[0189] An AP is one or more STAs and / or SBP initiators and can transmit information for group formation related to (cooperative) sensing procedures (i.e., group information) in a beacon frame, trigger frame, or other frame.

[0190] For example, group information may include information about the AP that acts as the group initiator, information about at least one STA included in the group, and information about sensing sessions conducted by the group.

[0191] As an example, the information relating to the sensing session may include at least one of the following: information relating to the period of the sensing session (i.e., if the sensing session is performed periodically), information relating to the start and end times of the sensing session, information relating to sensing bursts (or measurement instances) within the sensing session, or information transmitting per sensing burst.

[0192] Information regarding sensing bursts within a sensing session may include at least one of the following: the number of sensing bursts defined within a single sensing session, the number of signals that can be transmitted within a sensing burst, and the duration and / or period of the signals transmitted within a sensing burst.

[0193] The sensing burst-specific transmission information may include information about the role a particular STA plays in a particular burst (e.g., sensing sender, sensing receiver, or sensing sender and sensing receiver).

[0194] Here, the number of sensing bursts may be equal to or less than the number of STAs in the group, but is not limited to this. Information related to the sensing session may be sent by the sensing initiator (e.g., AP) to at least one STA included in the group for each sensing burst.

[0195] For each sensing burst defined during a sensing session, the sensing sender may engage in a channel acquisition competition for sensing. Channel acquisition competition may be performed by exchanging control frames (such as RTS / CTS frames).

[0196] In this case, in order to mitigate channel allocation conflicts (or the resulting OTA overhead) among multiple STAs, channel allocation and sensing session initiation procedures (e.g., initiation / trigger frame transmission or TXOP allocation) may be defined / determined / operated so that they can only be performed by the sensing sender of each sensing burst.

[0197] As yet another example, a central entity (e.g., an AP) can instruct a group owner (e.g., an SBP initiator) that the channel acquisition and sensing session initiation procedures can only be performed by the sensing sender. As yet another example, a central entity (e.g., an AP) can send information to at least one STA included in the group instructing which STA can perform the channel acquisition and sensing session initiation procedures.

[0198] As an example, indicators may be defined to enable / disable a mode of operation that ensures channel acquisition and sensing session initiation procedures are performed only by the sensing sender. The central entity can send the enable / disable indicator to at least one STA (or group owner and / or sensing sender).

[0199] A sensing initiator (e.g., an AP) can create a competition for obtaining a transmit channel for sensing during a sensing session. A SBP initiator (i.e., a non-AP STA that requested the sensing procedure) can act as a sensing sender, sensing receiver, and / or sensing sender and sensing receiver during a sensing session.

[0200] Examples 1-3

[0201] Examples 1-3 relate to the operation of AP and / or non-AP STA during the sounding phase (i.e., the phase in which the SBP initiator acts as a sensing transmitter and / or sensing receiver).

[0202] Each session may be initiated by a sensing initiator (e.g., an AP) after channel usage is acquired due to channel connection conflict. The sensing initiator may send information to the sensing responder indicating the start of sensing signal transmission.

[0203] The sensing initiator may send information related to the transmission of the sensing signal to the sensing responder using a (sensing) trigger frame. This information may include information about the bandwidth, channel, resource units, etc., used by the SBP initiator to transmit the sensing signal.

[0204] When a trigger frame indicates the start of sensing signal transmission (i.e., when a sensing initiator sends a trigger frame to at least one sensing responder), the sensing transmitter can perform the sensing signal transmission operation in SU (single user) mode. For example, a sensing transmitter can send an SU PPDU as a sensing signal to one or more sensing receivers.

[0205] The trigger frame may also include an indicator that the trigger frame is for initiating a (cooperative) sensing procedure.

[0206] For example, the trigger type subfield of a trigger frame can indicate that the trigger frame is for (cooperative) sensing. In this case, the trigger type subfield value may be 8, but is not limited to this; it may be set to any one of 9 to 15.

[0207] In a basic wireless LAN system, NDP transmission for trigger frames may be based on TB PPDU. In the case of cooperative sensing, NDP transmission for trigger frames may be based on SU PPDU, but is not limited to this.

[0208] As an addition or alternative, information relating to the transmission of sensing signals may be transmitted by an NDP announcement frame and / or another new frame. In this case, the NDP announcement frame and / or another new frame may include an indicator indicating that the purpose of the frame is to initiate / instruct a (cooperative) sensing procedure.

[0209] The sensing initiator may request that the sensing responder and sensing receiver, a non-AP STA, provide feedback regarding the channel environment. An immediate feedback procedure may be performed for each sensing burst, after a certain period (e.g., SIFS) following the transmission of the sounding signal (i.e., sensing signal). A delayed feedback procedure may be performed for each sensing burst, in other sensing bursts after the transmission of the sounding signal.

[0210] For example, information regarding the channel environment may include CSI (channel state information), TCIR (truncated channel impulse response), or results obtained after information processing regarding the channel environment.

[0211] Furthermore, after receiving a frame indicating the start of sensing signal transmission from the sensing initiator (e.g., a sensing trigger frame), and after a certain period of time, the SBP initiator can receive an SU NDP from another non-AP STA acting as a sensing transmitter (i.e., a non-AP STA participating in the cooperative sensing procedure). In other words, the SBP initiator can assume the role of a sensing receiver in the (cooperative) sensing procedure.

[0212] The SBP initiator can obtain information about the channel environment between itself and other non-AP STAs by receiving a sensing signal (e.g., SU NDP). The sensing initiator's AP can further transmit channel environment information related to other STAs to the SBP initiator by sending an SBP response frame.

[0213] In this case, the channel environment information between other STAs may include not only the channel environment information between the SBP initiator and other STAs, but also the channel environment information between other STAs.

[0214] Examples 1-4

[0215] Examples 1-4 relate to the operation of AP and / or non-AP STA during the SBP response phase (i.e., the phase in which the SBP initiator acts as the sensing transmitter).

[0216] The sensing initiator can identify the channel information received through feedback, specifically the information between the SBP initiator and the surrounding STAs. The sensing initiator can then transmit the identified channel information to the SBP initiator via an SBP response frame.

[0217] Here, the SBP response frame may include at least one of the following: information about the non-AP STA that provided the channel information feedback (e.g., the MAC ID and location information of the non-AP STA); information about the sensing burst (i.e., measurement instance) from which the channel information was obtained (e.g., burst ID or measurement ID); or the granularity of the channel information.

[0218] Here, the granularity of the channel information may include information regarding whether the channel information is subcarrier-specific information on a frequency basis, and / or information obtained by setting how many subcarriers constitute a single unit of the channel information.

[0219] Example 2-1

[0220] Example 2-1 relates to a collaborative sensing procedure process based on an SBP procedure according to one embodiment of the present disclosure (for example, the process when an SBP initiator acts as a sensing transmitter in a specific measurement instance).

[0221] Referring to Figure 10, STA2 (i.e., the SBP initiator) can send an SBP request frame to the AP requesting a sensing procedure (i.e., requesting an SBP). The AP can send a response frame to STA2 for the SBP request frame (i.e., an SBP response frame).

[0222] The SBP request frame may allow the AP to group STA2 and STA1 (e.g., non-AP STAs located around STA2) into a group for (cooperative) sensing. Assume that within the sensing procedure, STA2 acts as the (cooperative) sensing sender and STA1 acts as the (cooperative) sensing receiver.

[0223] The AP (i.e., the sensing initiator) can send a trigger frame 1010 to the sensing responders (e.g., STA1 and STA2). Here, the trigger frame 1010 may be an SR2SR sounding sensing trigger frame (i.e., a sensing trigger frame that is an SR2SR sounding variant). The sensing trigger frame that is an SR2SR sounding variant may contain information related to the sensing measurement procedure between the sensing responders (i.e., a collaborative sensing measurement procedure).

[0224] STA2 can transmit sensing signals (e.g., SU PPDU and / or SR2SR NDP) 1020 to AP and / or STA1. AP and / or STA1 can obtain channel information (e.g., channel information between AP and STA2 and / or channel information between STA1 and STA2) from sensing signals 1020.

[0225] Here, STA2 can transmit a sensing signal (e.g., SU PPDU and / or SR2SR NDP) 1020 to AP and / or STA1 based on the information contained in the (sensing) trigger frame 1010 received from AP.

[0226] AP can send a (sensing) trigger frame 1030 to STA1 requesting channel information (i.e., a (sensing) trigger frame for triggering channel information reporting). This allows STA1 to send / report to AP 1040 the channel information between STA1 and STA2 obtained by the sensing signal received from STA2.

[0227] The AP can transmit the channel information between STA1 and STA2, received from STA1, to STA2 using an SBP report frame 1050. The SBP report frame 1050 may also include channel information between other STAs.

[0228] Example 2-2

[0229] Example 2-2 relates to a collaborative sensing procedure process based on an SBP procedure according to one embodiment of the present disclosure (for example, the process when an SBP initiator acts as a sensing receiver in a specific measurement instance).

[0230] Referring to Figure 11, the AP can send a (sensing) trigger frame to STA1, STA2 (i.e., the SBP initiator), and STA3 to trigger the (cooperative) sensing procedure.

[0231] In this (cooperative) sensing procedure, STA1, acting as a sensing transmitter, can transmit a sensing signal (e.g., SU PPDU) to AP, STA2, and STA3 based on the trigger frame. AP, STA2, and STA3 can then acquire channel information based on the sensing signal.

[0232] The AP can send a trigger frame requesting channel information from at least one of STA1, STA2, and STA3. For example, STA3 can report channel information between STA1 and STA3 to the AP based on the trigger frame.

[0233] The AP can send an SBP response frame to STA2 that contains channel information between STA1 and STA3. The SBP response frame may also contain other channel information (for example, channel information between the AP and STA3).

[0234] The embodiments described above are combinations of the components and features of the present disclosure in a predetermined form. Each component or feature should be considered optional unless otherwise explicitly mentioned. Each component or feature may be implemented in a form that does not combine with other components or features. It is also possible to combine some components and / or features to constitute embodiments of the present disclosure. The order of operations described in embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in other embodiments, or replaced by corresponding components or features of other embodiments. It is clear that claims that do not have an explicit reference relationship in the claims may be combined to constitute embodiments, or may be included as new claims by amendment after filing.

[0235] It will be obvious to those skilled in the art that this disclosure can be embodied in other specific forms, provided that the essential features of this disclosure are not deviated from. Therefore, the above-mentioned detailed description should not be constrained in any way and should be considered illustrative. The scope of this disclosure should be determined by a reasonable interpretation of the attached claims, and any modifications within the equivalent scope of this disclosure are included within the scope of this disclosure.

[0236] The scope of this disclosure includes software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that cause an apparatus or computer to perform operations according to the methods of various embodiments, and non-transitory computer-readable medium on which such software or instructions are stored and executable on the apparatus or computer. Instructions available for programming a processing system that performs the features described in this disclosure may be stored on / in a storage medium or computer-readable storage medium, and the features described in this disclosure may be embodied using a computer program product including such storage medium. The storage medium may include, but is not limited to, high-speed random-access memory such as DRAM, SRAM, DDR RAM, or other random-access solid-state memory devices, and may include non-volatile memory such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. Memory optionally includes one or more storage devices located remotely from the processor. Memory, or alternatively, non-volatile memory devices within memory, includes non-transitory computer-readable storage medium. The features described in this disclosure may be stored on any one of the machine-readable media and integrated into software and / or firmware that can control the hardware of the processing system and cause the processing system to interact with other mechanisms that utilize the results relating to 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.

[0237] [Industrial applicability] Although the method proposed in this disclosure has been described primarily in the context of its application to IEEE 802.11-based systems, it can be applied to a variety of other wireless LAN or wireless communication systems.

[0238] [Claims when filing an international application] [Claim 1] A method performed by a first station (STA) in a wireless LAN system, The second STA involves sending a first frame to request the SBP (sensing by proxy) procedure; The steps include receiving a second frame in response to the first frame from the second STA; The process includes: receiving a third frame related to a sensing measurement report based on the first frame from the second STA; The first frame mentioned above is, First information related to the SR2SR (sensing responder to sensing responder) sounding procedure, and A method comprising second information indicating whether the first STA participates in the SR2SR sounding procedure. [Claim 2] The method according to claim 1, wherein the first frame includes at least one of the following: the number of at least one sensing responders participating in the SR2SR sounding procedure, or the ID (identity) information of the at least one sensing responder, or information relating to the role of the at least one sensing responder. [Claim 3] The method according to claim 2, wherein the first information is indicated by a field requesting the SR2SR sounding procedure with the at least one sensing responder. [Claim 4] The information relating to the role of the at least one sensing responder is indicated by the sensing responder role bitmap field. The role of the aforementioned at least one sensing responder is, i) Sensing transmitter, ii) Sensing receiver, or iii) The method according to claim 2, wherein the sensing transmitter and the sensing receiver are one of the two. [Claim 5] The method according to claim 1, wherein, based on the second information indicating that the first STA is to participate in the SR2SR sounding procedure, a first trigger frame or sensing NDP (null data physical layer protocol data unit) announcement frame related to the SR2SR sounding procedure is received from the second STA. [Claim 6] The method according to claim 5, wherein, based on the fact that the first STA is a sensing transmitter, a sensing signal based on the first trigger frame or the sensing NDP known frame is transmitted to at least one sensing responder participating in the SR2SR sounding procedure. [Claim 7] The method according to claim 6, wherein the sensing signal transmitted in the SR2SR sounding procedure includes a SU (single user) NDP. [Claim 8] A fourth frame is transmitted from the second STA to the at least one sensing responder requesting that the channel information acquired based on the sensing signal be reported. The method according to claim 6, wherein the channel information is transmitted from the at least one sensing responder to the second STA based on the fourth frame. [Claim 9] The method according to claim 8, wherein the third frame includes at least one of the following: the channel information, the measurement session ID associated with the channel information, or the ID of the sensing responder who acquired the channel information. [Claim 10] The method according to claim 1, wherein the procedure for transmitting the third frame is initiated after SIFS by a trigger-based sensing procedure corresponding to the sensing measurement session initiated by the second STA. [Claim 11] The first STA and the at least one sensing responder are non-AP STAs, The method according to claim 1, wherein the second STA is an access point (AP). [Claim 12] A first station (STA:station) operating in a wireless LAN system, One or more transceivers, The system comprises one or more processors connected to one or more of the aforementioned transceivers, The one or more processors described above are: The second STA receives a first frame via one or more transceivers to request the SBP (sensing by proxy) procedure; The second STA receives a second frame in response to the first frame via one or more transceivers; The second STA is configured to receive a third frame related to the sensing measurement report based on the first frame, via one or more transceivers; The first frame mentioned above is, First information related to the SR2SR (sensing responder to sensing responder) sounding procedure, and A first STA, which includes second information indicating whether or not the first STA participates in the SR2SR sounding procedure. [Claim 13] A method performed by a second station (STA) in a wireless LAN system, From the first STA, the first frame is received to request the SBP (sensing by proxy) procedure; The steps include transmitting a second frame in response to the first frame to the first STA; The first STA includes the step of transmitting a third frame related to a sensing measurement report based on the first frame; The first frame mentioned above is, First information related to the SR2SR (sensing responder to sensing responder) sounding procedure, and A method comprising second information indicating whether the first STA participates in the SR2SR sounding procedure. [Claim 14] A second station (STA:station) operating in a wireless LAN system, One or more transceivers, The system comprises one or more processors connected to one or more of the aforementioned transceivers, The one or more processors described above are: The first STA receives a first frame requesting an SBP (sensing by proxy) procedure via one or more transceivers; A second frame in response to the first frame is transmitted to the first STA via one or more transceivers; The first STA is configured to transmit a third frame related to the sensing measurement report based on the first frame via one or more transceivers; The first frame mentioned above is, First information related to the SR2SR (sensing responder to sensing responder) sounding procedure, and A second STA, which includes second information indicating whether or not the first STA participates in the SR2SR sounding procedure. [Claim 15] A processing device configured to control a first station (STA:station) operating in a wireless LAN system, One or more processors, The system comprises one or more computer memories that are operably connected to one or more processors and store instructions for performing operations based on execution by the one or more processors, The aforementioned operation is, The second STA performs the action of sending a first frame to request the SBP (sensing by proxy) procedure; The operation of receiving a second frame in response to the first frame from the second STA; The operation includes receiving a third frame related to a sensing measurement report from the second STA based on the first frame, The first frame mentioned above is, First information related to the SR2SR (sensing responder to sensing responder) sounding procedure, and A processing device including second information indicating whether the first STA participates in the SR2SR sounding procedure. [Claim 16] One or more non-transitory computer-readable media for storing one or more instructions, The aforementioned one or more instructions are executed by one or more processors, and the device operating in the wireless LAN system is, Send the first frame to the second STA to request the SBP (sensing by proxy) procedure; The second STA receives a second frame in response to the first frame; The second STA is controlled to receive a third frame related to the sensing measurement report based on the first frame; The first frame mentioned above is, First information related to the SR2SR (sensing responder to sensing responder) sounding procedure, and A computer-readable medium including second information indicating whether the first STA participates in the SR2SR sounding procedure.

Claims

1. A method performed by a first station (STA) in a wireless LAN system, The second STA is sent a first frame to request the SBP (sensing by proxy) procedure; The steps include receiving a second frame in response to the first frame from the second STA; The process includes: receiving a third frame related to a sensing measurement report based on the first frame from the second STA; The first frame mentioned above is, First information relating to the SR2SR (sensing responder to sensing responder) sounding procedure, and A method comprising second information indicating whether the first STA participates in the SR2SR sounding procedure.

2. The method according to claim 1, wherein the first frame includes at least one of the following: the number of at least one sensing responders participating in the SR2SR sounding procedure, or the ID (identity) information of the at least one sensing responder, or information relating to the role of the at least one sensing responder.

3. The method according to claim 2, wherein the first information is indicated by a field requesting the SR2SR sounding procedure with the at least one sensing responder.

4. The information relating to the role of the at least one sensing responder is indicated by the sensing responder role bitmap field. The role of the at least one sensing responder is, i) Sensing transmitter, ii) Sensing receiver, or iii) The method according to claim 2, wherein the sensing transmitter and the sensing receiver are one of the above.

5. The method according to claim 1, wherein, based on the second information instructing the first STA to participate in the SR2SR sounding procedure, a first trigger frame or sensing NDP (null data physical layer protocol data unit) known frame related to the SR2SR sounding procedure is received from the second STA.

6. The method according to claim 5, wherein, based on the fact that the first STA is a sensing transmitter, a sensing signal based on the first trigger frame or the sensing NDP known frame is transmitted to at least one sensing responder participating in the SR2SR sounding procedure.

7. The method according to claim 6, wherein the sensing signal transmitted in the SR2SR sounding procedure includes a SU (single user) NDP.

8. A fourth frame is transmitted from the second STA to the at least one sensing responder requesting that the channel information acquired based on the sensing signal be reported. The method according to claim 6, wherein the channel information is transmitted from the at least one sensing responder to the second STA based on the fourth frame.

9. The method according to claim 8, wherein the third frame includes at least one of the following: the channel information, the measurement session ID associated with the channel information, or the ID of the sensing responder who acquired the channel information.

10. The method according to claim 1, wherein the procedure for transmitting the third frame is initiated after SIFS by performing a TB (trigger-based) sensing procedure corresponding to the sensing measurement session initiated by the second STA.

11. The first STA and the at least one sensing responder are non-AP STAs, The method according to claim 1, wherein the second STA is an access point (AP).

12. A first station (STA) operating in a wireless LAN system, One or more transceivers, The system comprises one or more processors connected to one or more of the aforementioned transceivers, The one or more processors described above are: A first frame is transmitted to the second STA via one or more transceivers to request an SBP (sensing by proxy) procedure; The second STA receives a second frame in response to the first frame via one or more transceivers; The second STA is configured to receive a third frame related to the sensing measurement report based on the first frame, via one or more transceivers; The first frame mentioned above is, First information relating to the SR2SR (sensing responder to sensing responder) sounding procedure, and A first STA, which includes second information indicating whether or not the first STA participates in the SR2SR sounding procedure.

13. A method performed by a second station (STA) in a wireless LAN system, The first stage involves receiving the first frame from the first STA to request the SBP (sensing by proxy) procedure; The steps include: transmitting a second frame in response to the first frame to the first STA; The process includes the step of transmitting a third frame related to a sensing measurement report to the first STA based on the first frame; The first frame mentioned above is, First information relating to the SR2SR (sensing responder to sensing responder) sounding procedure, and A method comprising second information indicating whether the first STA participates in the SR2SR sounding procedure.

14. A second station (STA) operating in a wireless LAN system, One or more transceivers, The system comprises one or more processors connected to one or more of the aforementioned transceivers, The one or more processors described above are: The first STA receives a first frame via one or more transceivers to request an SBP (sensing by proxy) procedure; A second frame in response to the first frame is transmitted to the first STA via one or more transceivers; The first STA is configured to transmit a third frame related to the sensing measurement report based on the first frame via one or more transceivers; The first frame mentioned above is, First information relating to the SR2SR (sensing responder to sensing responder) sounding procedure, and A second STA, which includes second information indicating whether or not the first STA participates in the SR2SR sounding procedure.

15. A processing device configured to control a first station (STA) operating in a wireless LAN system, One or more processors, The system comprises one or more computer memories that are operably connected to one or more processors and store instructions for performing operations based on execution by the one or more processors, The aforementioned operation is, The operation involves sending a first frame to the second STA to request the SBP (sensing by proxy) procedure; The operation of receiving a second frame in response to the first frame from the second STA; The operation includes receiving a third frame related to a sensing measurement report from the second STA based on the first frame, The first frame mentioned above is, First information relating to the SR2SR (sensing responder to sensing responder) sounding procedure, and A processing device including second information indicating whether the first STA participates in the SR2SR sounding procedure.

16. One or more non-transitory computer-readable media for storing one or more instructions, The aforementioned one or more instructions are executed by one or more processors, and the device operating in the wireless LAN system is, Send a first frame to the second STA to request the SBP (sensing by proxy) procedure; The second STA receives a second frame in response to the first frame; The second STA is controlled to receive a third frame related to the sensing measurement report based on the first frame; The first frame mentioned above is, First information relating to the SR2SR (sensing responder to sensing responder) sounding procedure, and A computer-readable medium including second information indicating whether the first STA participates in the SR2SR sounding procedure.

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