CN117882478A

CN117882478A - Method and apparatus for sensing correlation establishment in wireless LAN system

Info

Publication number: CN117882478A
Application number: CN202280056091.3A
Authority: CN
Inventors: 张仁善; 崔镇洙; 林东局; 金相局
Original assignee: LG Electronics Inc
Current assignee: LG Electronics Inc
Priority date: 2021-08-13
Filing date: 2022-08-12
Publication date: 2024-04-12

Abstract

Methods and apparatus for sensing correlation establishment in a wireless LAN system are disclosed. A method of a first Station (STA) performing sensing correlation establishment in a wireless LAN system according to an embodiment disclosed herein includes the steps of: transmitting, to the second STA, an establishment request frame including information related to a role of the second STA; and receiving a setup response frame from the second STA, wherein the information related to the role of the second STA may indicate a sensing transmitter role of the second STA, a sensing receiver role of the second STA, or both the sensing transmitter role and the sensing receiver role of the second STA.

Description

Method and apparatus for sensing correlation establishment in wireless LAN system

Technical Field

The present disclosure relates to sensing procedures in Wireless Local Area Network (WLAN) systems, and more particularly, to methods and apparatus for sensing correlation establishment in WLAN systems.

Background

New technologies for improving transmission rate, increasing bandwidth, improving reliability, reducing errors, and reducing delay have been introduced for Wireless LANs (WLANs). In WLAN technology, the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of standards may be referred to as Wi-Fi. For example, technologies recently introduced into WLANs include Very High Throughput (VHT) enhancements of the 802.11ac standard and High Efficiency (HE) enhancements of the IEEE 802.11ax standard.

An improved technique for providing sensing (i.e., WLAN sensing) for a device by using WLAN signals is being discussed. For example, in IEEE 802.11 Task Group (TG) bf, standard techniques for performing sensing of objects (e.g., persons, people, things, etc.) are being developed based on channel estimation using WLAN signals between devices operating in a frequency band below 7 GHz. Object sensing based on WLAN signals has the advantage of utilizing existing frequency bands and the advantage of less likelihood of privacy violation than existing detection techniques. As the frequency range used in the WLAN technology increases, accurate sensing information can be obtained, and together with this, technologies for reducing power consumption to efficiently support an accurate sensing procedure are also being studied.

Disclosure of Invention

Technical problem

A technical problem of the present disclosure is to provide methods and apparatus for sensing correlation establishment in WLAN systems.

An additional technical problem of the present disclosure is to provide methods and apparatus for indicating a role of a Station (STA) in sensing related establishment in a WLAN system.

An additional technical problem of the present disclosure is to provide a transmission or reception method and apparatus for establishing parameters required for a request and response process based on sensing correlation and for exchanging frames of the parameters in a WLAN system.

Technical objects to be achieved by the present disclosure are not limited to the above technical objects, and other technical objects not described herein will be apparent to those skilled in the art from the following description.

Technical proposal

A method of a first Station (STA) transmitting a trigger frame in a WLAN system according to an aspect of the present disclosure includes the steps of: transmitting a first physical layer protocol data unit (PPDU) including the trigger frame to at least one second STA; and receiving a second PPDU from at least one of the at least one second STA based on the trigger frame, and a method of performing sensing correlation establishment by a first Station (STA) in a WLAN system according to an aspect of the present disclosure includes the steps of: transmitting, to a second STA, an establishment request frame including information related to a role of the second STA; and receiving a setup response frame from the second STA, the information related to the role of the second STA may indicate a sensing transmitter role of the second STA, a sensing receiver role of the second STA, or both the sensing transmitter role and the sensing receiver role of the second STA.

A method of performing sensing correlation establishment by a second Station (STA) in a WLAN system according to an additional aspect of the present disclosure includes the steps of: receiving, from a first STA, an establishment request frame including information related to a role of the second STA; and transmitting a setup response frame to the first STA, the information related to the role of the second STA may indicate a sensing transmitter role of the second STA, a sensing receiver role of the second STA, or both the sensing transmitter role and the sensing receiver role of the second STA.

Advantageous effects

In accordance with the present disclosure, methods and apparatus for sensing correlation establishment in WLAN systems may be provided.

In accordance with the present disclosure, methods and apparatus for indicating a role of a Station (STA) in sensing correlation establishment in a WLAN system may be provided.

According to the present disclosure, a transmission or reception method and apparatus for establishing parameters required for a request and response process based on sensing correlation and for exchanging frames of the parameters in a WLAN system may be provided.

The effects achievable by the present disclosure are not limited to the above-described effects, and other effects not described herein can be clearly understood by those skilled in the art from the following description.

Drawings

The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the detailed description describe the features of the disclosure.

Fig. 1 illustrates a block diagram of a configuration of a wireless communication device according to an embodiment of the present disclosure.

Fig. 2 is a diagram illustrating an exemplary structure of a WLAN system to which the present disclosure may be applied.

Fig. 3 is a diagram for explaining a link establishment process to which the present disclosure can be applied.

Fig. 4 is a diagram for explaining a backoff process (backoff process) to which the present disclosure may be applied.

Fig. 5 is a diagram for explaining a CSMA/CA-based frame transmission operation to which the present disclosure can be applied.

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

Fig. 7 is a diagram illustrating an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure may be applied.

Fig. 8 to 10 are diagrams for explaining examples of resource units of a WLAN system to which the present disclosure can be applied.

Fig. 11 illustrates an example structure of the HE-SIG-B field.

Fig. 12 is a diagram for explaining a MU-MIMO method in which a plurality of users/STAs are allocated to one RU.

Fig. 13 illustrates an example of a PPDU format to which the present disclosure may be applied.

Fig. 14 shows an example format of a trigger frame to which the present disclosure may be applied.

Fig. 15 is a diagram for describing an example of a sensing-related setup request method of a first STA according to the present disclosure.

Fig. 16 is a diagram for describing an example of a sensing-related setup response method of a second STA according to the present disclosure.

Fig. 17 is a diagram showing an example of a format of a setup request frame or a setup response frame according to the present disclosure.

Fig. 18 is a diagram illustrating various examples of sensing correlation setup requests and responses according to the present disclosure.

Fig. 19 is a diagram illustrating an example of a sensing correlation setup response method according to the present disclosure.

Fig. 20 is a diagram illustrating an example of a sensing-related setup request/response method according to the present disclosure.

Detailed Description

Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed by the drawings is intended to describe exemplary embodiments of the disclosure and is not intended to represent the only embodiments in which the disclosure may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present disclosure. However, it will be apparent to one skilled in the relevant art that the present disclosure may be practiced without these specific details.

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

In this disclosure, when an element is referred to as being "connected," "combined," or "linked" to another element, it can comprise the indirect connection and the direct connection of yet another element therebetween. Furthermore, in the present disclosure, the terms "comprises" and/or "comprising" specify the presence of stated features, steps, operations, components, and/or elements, but do not preclude the presence or addition of one or more other features, stages, operations, components, elements, and/or groups thereof.

In the present invention, terms such as "first," "second," and the like are used merely to distinguish one element from another element and are not used to limit the elements unless otherwise stated, they do not limit the order or importance between the elements, etc. Thus, within the scope of the present disclosure, a first element in an embodiment may be referred to as a second element in another embodiment, and as such, a second element in an embodiment may be referred to as a first element in another embodiment.

The terminology used in the present disclosure is for the purpose of describing particular embodiments, and is not intended to limit the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "and/or" as used in this disclosure may refer to one of the relevant listed items or to any and all possible combinations of two or more of them. Furthermore, unless otherwise indicated, the words "/" and/or "between words in the present invention have the same meaning.

Examples of the present disclosure may be applied to various wireless communication systems. For example, examples of the present disclosure may be applied to wireless LAN systems. For example, examples of the present disclosure may be applied to wireless LANs based on the IEEE 802.11a/g/n/ac/ax standard. Further, examples of the present disclosure may be applied to wireless LANs based on the newly proposed IEEE 802.11be (or EHT) standard. Examples of the present disclosure may be applied to wireless LANs based on the IEEE 802.11be version 2 standard corresponding to the additional enhancements of the IEEE 802.11be version 1 standard. In addition, examples of the present disclosure may be applied to a wireless LAN based on the next generation standard after IEEE 802.11 be. Additionally, examples of the present disclosure may be applied to cellular wireless communication systems. For example, it may be applied to cellular wireless communication systems based on Long Term Evolution (LTE) technology and 5G New Radio (NR) technology of the third generation partnership project (3 GPP) standard.

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

Fig. 1 illustrates a block diagram of a wireless communication device according to an embodiment of the present disclosure.

The first apparatus 100 and the second apparatus 200 illustrated in fig. 1 may be replaced with various terms such as a terminal, a wireless apparatus, a Wireless Transmit Receive Unit (WTRU), a User Equipment (UE), a Mobile Station (MS), a User Terminal (UT), a mobile subscriber station (MSs), a Mobile Subscriber Unit (MSU), a Subscriber Station (SS), an Advanced Mobile Station (AMS), a Wireless Terminal (WT), or a simple user. In addition, the first apparatus 100 and the second apparatus 200 include an Access Point (AP), a Base Station (BS), a fixed station, a node B, a Base Transceiver System (BTS), a network. It may be replaced with various terms such as an Artificial Intelligence (AI) system, a roadside unit (RSU), a repeater, a router, a relay, and a gateway.

The apparatuses 100 and 200 illustrated in fig. 1 may be referred To As Stations (STAs). For example, the apparatuses 100 and 200 illustrated in fig. 1 may be referred to by various terms such as a transmitting apparatus, a receiving apparatus, a transmitting STA, and a receiving STA. For example, STAs 110 and 200 may perform an Access Point (AP) role or a non-AP role. That is, in the present disclosure, STAs 110 and 200 may perform AP and/or non-AP functions. STAs 110 and 200 may be simply referred to as APs when they perform AP functions, and STAs 110 and 200 may be simply referred to as STAs when they perform non-AP functions. In addition, in the present disclosure, an AP may also be indicated as an AP STA.

Referring to fig. 1, the first device 100 and the second device 200 may transmit and receive radio signals through various wireless LAN technologies (e.g., IEEE 802.11 series). The first apparatus 100 and the second apparatus 200 may include interfaces for a Medium Access Control (MAC) layer and a physical layer (PHY) compliant with the IEEE 802.11 standard.

In addition, the first apparatus 100 and the second apparatus 200 may additionally support various communication standard (e.g., 3GPP LTE series, 5G NR series standards, etc.) technologies in addition to the wireless LAN technology. In addition, the apparatus of the present disclosure may be implemented in various apparatuses such as a mobile phone, a vehicle, a personal computer, an Augmented Reality (AR) device, and a Virtual Reality (VR) device. In addition, STAs of the present description may support various communication services such as voice calls, video calls, data communications, autonomous driving, machine Type Communications (MTC), machine-to-machine (M2M), device-to-device (D2D), ioT (internet of things), and the like.

The first apparatus 100 may include one or more processors 102 and one or more memories 104, and may additionally include one or more transceivers 106 and/or one or more antennas 108. The processor 102 may control the memory 104 and/or the transceiver 106 and may be configured to implement the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts included in the present disclosure. For example, the processor 102 may transmit a wireless signal including the first information/signal through the transceiver 106 after generating the first information/signal by processing the information in the memory 104. In addition, the processor 102 may receive a wireless signal including the second information/signal through the transceiver 106 and then store information obtained through signal processing of the second information/signal in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software code including instructions for performing all or part of the processing controlled by the processor 102 or for performing descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts included in the present disclosure. Here, the processor 102 and the memory 104 may be part of a communication modem/circuit/chip designed to implement wireless LAN technology (e.g., IEEE 802.11 family). The transceiver 106 may be coupled to the processor 102 and may transmit and/or receive wireless signals via one or more antennas 108. Transceiver 106 may include a transmitter and/or a receiver. The transceiver 106 may be used with an RF (radio frequency) unit. In this disclosure, a wireless device may mean a communication modem/circuit/chip.

The second apparatus 200 may include one or more processors 202 and one or more memories 204, and may additionally include one or more transceivers 206 and/or one or more antennas 208. The processor 202 may control the memory 204 and/or the transceiver 206 and may be configured to implement the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts included in the present disclosure. For example, the processor 202 may generate the third information/signal by processing the information in the memory 204 and then transmit a wireless signal including the third information/signal through the transceiver 206. In addition, the processor 202 may receive a wireless signal including fourth information/signals through the transceiver 206 and then store information obtained through signal processing of the fourth information/signals in the memory 204. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may store software code including instructions for performing all or part of the processing controlled by the processor 202 or for performing descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts included in the present disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem/circuit/chip designed to implement wireless LAN technology (e.g., IEEE 802.11 family). The transceiver 206 may be coupled to the processor 202 and may transmit and/or receive wireless signals via one or more antennas 208. Transceiver 206 may include a transmitter and/or a receiver. The transceiver 206 may be used with an RF unit. In this disclosure, an apparatus may refer to a communication modem/circuit/chip.

Hereinafter, the hardware elements of the apparatus 100, 200 will be described in more detail. Without limitation, one or more protocol layers may be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 may implement one or more layers (e.g., functional layers such as PHY, MAC). The one or more processors 102, 202 may generate one or more PDUs (protocol data units) and/or one or more SDUs (service data units) according to the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed in the present disclosure. One or more processors 102, 202 may generate messages, control information, data, or information in accordance with the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed in this disclosure. The one or more processors 102, 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information to provide to the one or more transceivers 106, 206 according to the functions, procedures, suggestions, and/or methods disclosed in the present disclosure. The one or more processors 102, 202 may receive signals (e.g., baseband signals) from the one or more transceivers 106, 206 and obtain PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts included in the present disclosure.

One or more of the processors 102, 202 may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more of the processors 102, 202 may be implemented in 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 the one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts included in the present disclosure may be implemented by using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, and so on. Firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods, and/or operational flow diagrams included in the present disclosure may be included in one or more processors 102, 202 or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts included in the present disclosure may be implemented using firmware or software in the form of codes, instructions and/or instruction sets.

The one or more memories 104, 204 may be connected to the one or more processors 102, 202 and may store data, signals, messages, information, programs, code, instructions, and/or commands in various forms. One or more of the memories 104, 204 may be configured with ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer readable storage medium, and/or combinations thereof. The one or more memories 104, 204 may be located internal and/or external to the one or more processors 102, 202. In addition, one or more memories 104, 204 may be connected to one or more processors 102, 202 through various techniques, such as a wired or wireless connection.

One or more transceivers 106, 206 may transmit user data, control information, wireless signals/channels, etc. referred to in the methods and/or operational flowcharts, etc. of the present disclosure to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals/channels, etc. referred to in descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts, etc. included in the present disclosure, from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and may transmit and receive wireless signals. For example, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. In addition, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. In addition, one or more transceivers 106, 206 may be 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, wireless signals/channels, etc. mentioned in descriptions, functions, procedures, suggestions, methods, operational flowcharts, etc. included in the present disclosure through one or more antennas 108, 208. In the present disclosure, the one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). The one or more transceivers 106, 206 may convert received wireless signals/channels, etc. from RF band signals to baseband signals to process received user data, control information, wireless signals/channels, etc. using the one or more processors 102, 202. The one or more transceivers 106, 206 may convert user data, control information, wireless signals/channels, etc., processed by using the one or more processors 102, 202 from baseband signals to RF band signals. Thus, one or more transceivers 106, 206 may include (analog) oscillators and/or filters.

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

Hereinafter, downlink (DL) may mean a link for communication from an AP STA to a non-AP STA, and may transmit and receive DL PPDUs/packets/signals through DL. In DL communication, the transmitter may be part of an AP STA and the receiver may be part of a non-AP STA. The Uplink (UL) may mean a link for communication from a non-AP STA to an AP STA, and may transmit and receive UL PPDUs/packets/signals through the UL. In UL communication, the transmitter may be part of a non-AP STA and the receiver may be part of an AP STA.

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

The structure of the wireless LAN system may be constituted by a plurality of components. A wireless LAN supporting STA mobility transparent to upper layers may be provided through interaction of multiple components. A Basic Service Set (BSS) corresponds to a basic building block of a wireless LAN. Fig. 2 exemplarily shows that there are two BSSs (BSS 1 and BSS 2), and two STAs included as members of each BSS (STA 1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS 2). The ellipse representing the BSS in fig. 2 may also be understood as representing the coverage area in which STAs included in the corresponding BSS remain in communication. This region may be referred to as a Basic Service Area (BSA). When an STA moves outside the BSA, it cannot communicate directly with other STAs within the BSA.

If the DS shown in fig. 2 is not considered, the most basic BSS type in the wireless LAN is an Independent BSS (IBSS). For example, an IBSS may have a minimal form that includes only two STAs. For example, assuming that other components are omitted, BSS1 including only STA1 and STA2 or BSS2 including only STA3 and STA4 may correspond to representative examples of IBSS, respectively. This configuration is possible when STAs can communicate directly without an AP. In addition, in this type of wireless LAN, it is not preconfigured, but may be configured when a LAN is required, and this may be referred to as an ad-hoc (ad-hoc) network. Since IBSS does not include an AP, there is no centralized management entity. That is, in IBSS, STAs are managed in a distributed manner. In an IBSS, all STAs may consist of mobile STAs and are not allowed to access the Distributed System (DS), thus forming a self-contained network.

Membership of STAs in a BSS may be dynamically changed by switching the STAs on or off, entering or exiting a BSS area, etc. To become a member of the BSS, the STA may join the BSS using a synchronization process. To access all services of the BSS infrastructure, the STA should be associated with the BSS. The association may be dynamically established and may include use of a Distributed System Service (DSS).

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

DS means a structure in which BSSs are interconnected. Specifically, as shown in fig. 2, the BSS may exist as an extension of a network composed of a plurality of BSSs. DS is a logical concept and may be specified by the characteristics of a Distributed System Medium (DSM). In this regard, the Wireless Medium (WM) and DSM may be logically separated. Each logic medium serves a different purpose and is used by different components. These media are not limited to being identical nor are they limited to being different. In this way, the flexibility of the wireless LAN structure (DS structure or other network structure) can be interpreted as a plurality of media being logically different. That is, the wireless LAN structure may be implemented in various ways, and the corresponding wireless LAN structure may be independently specified by the physical characteristics of each embodiment.

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

The AP enables access to the DS by the WM for associated non-AP STAs and means entities that also have STA functionality. Data movement between the BSS and the DS may be performed by the AP. For example, STA2 and STA3 shown in fig. 2 have functions of STAs and provide functions of allowing associated non-AP STAs (STA 1 and STA 4) to access the DS. In addition, since all APs correspond to STAs substantially, all APs are addressable entities. The address used by the AP to communicate on the WM is not necessarily the same as the address used by the AP to communicate on the DSM. A BSS made up of an AP and one or more STAs may be referred to as an infrastructure BSS.

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

In addition to the structure of the DS described above, an Extended Service Set (ESS) may also be configured to provide wide coverage.

ESS means a network consisting of DS and BSS with arbitrary size and complexity. The ESS may correspond to a set of BSSs connected to one DS. However, the ESS does not include a DS. The ESS network is characterized as an IBSS in the Logical Link Control (LLC) layer. STAs included in the ESS may communicate with each other and the mobile STA may move transparently to the LLC from one BSS to another BSS (within the same ESS). The APs included in one ESS may have the same Service Set Identification (SSID). The SSID is distinguished from the BSSID, which is an identifier of the BSS.

The wireless LAN system does not assume anything about the relative physical location of the BSS, and all the following forms are possible. BSSs may overlap in part, which is a form commonly used to provide continuous coverage. In addition, BSSs may not be physically connected, and logically, there is no limitation on the distance between BSSs. In addition, BSSs may be physically co-located, which may be used to provide redundancy. In addition, one (or more than one) IBSS or ESS network may physically exist in the same space as one (or more than one) ESS network. This may correspond to the form of the ESS network, etc. when the ad hoc network operates in a location where the ESS network exists, when physically overlapping wireless networks are configured by different organizations, or when two or more different access and security policies are required in the same location.

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

In step S310, the STA may perform a network discovery operation. The network discovery operation may include a scanning operation of the STA. That is, in order for a STA to access a network, it needs to find a network in which it can participate. The STA should identify a compatible network before participating in a wireless network, and the process of identifying a network existing in a specific area is called scanning.

The scanning scheme includes active scanning and passive scanning. Fig. 3 exemplarily illustrates a network discovery operation including an active scanning process. In the active scanning, the STA performing the scanning transmits a probe request frame to discover which APs exist around it while the channel moves and waits for a response thereto. The responder transmits a probe response frame as a response to the probe request frame to the STA that has transmitted the probe request frame. Here, the responder may be a STA that finally transmits a beacon frame in the BSS of the channel being scanned. In the BSS, the AP becomes a responder since the AP transmits a beacon frame, and in the IBSS, the STA in the IBSS rotates to transmit the beacon frame, so the responder is not constant. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 may store BSS-related information included in the received probe response frame and may move to the next channel (e.g., channel 2) and perform scanning in the same manner (i.e., transmission and reception of probe request/response on channel 2).

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

After the STA discovers the network, an authentication process may be performed at step S320. This authentication process may be referred to as a first authentication process in order to clearly distinguish from the security setup operation of step S340, which will be described later.

The authentication process includes the following processes: the STA transmits an authentication request frame to the AP, and in response thereto, the AP transmits an authentication response frame to the STA. The authentication frame for authentication request/response corresponds to the management frame.

The authentication frame includes an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text (challenge text), a Robust Secure Network (RSN), a limited loop group, and the like. This corresponds to some examples of information that may be included in the authentication request/response frame, and may be replaced with other information, or additional information may also be included.

The STA may transmit an authentication request frame to the AP. The AP may determine whether to allow authentication of the corresponding STA based on information included in the received authentication request frame. The AP may provide the result of the authentication process to the STA through the authentication response frame.

After the STA is successfully authenticated, association processing may be performed at step S330. The association processing includes the following processing: the STA transmits an association request frame to the AP, and in response, the AP transmits an association response frame to the STA.

For example, the association request frame may include information related to various capabilities, beacon listening intervals, service Set Identifiers (SSID), supported rates, supported channels, RSNs, mobile domains, supported operation categories, traffic indication map broadcast requests (TIM broadcast requests), interworking service capabilities, and so forth. For example, the association response frame may include information related to various capabilities, status codes, association IDs (AID), supported rates, enhanced Distributed Channel Access (EDCA) parameter sets, received Channel Power Indicator (RCPI), received signal-to-noise indicator (RSNI), mobile domain, time-out interval (e.g., association recovery time), overlapping BSS scan parameters, TIM broadcast response, quality of service (QoS) mapping, and so forth. This corresponds to some examples of information that may be included in the association request/response frame, and may be replaced with other information, or additional information may also be included.

After the STA is successfully associated with the network, a security setup process may be performed at step S340. The security setup process of step S340 may be referred to as an authentication process for request/response through a Robust Security Network Association (RSNA), the authentication process of step S320 is referred to as a first authentication process, and the security setup process of step S340 may also be simply referred to as an authentication process.

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

Fig. 4 is a diagram for explaining back-off processing to which the present disclosure can be applied.

In a wireless LAN system, a basic access mechanism of Medium Access Control (MAC) is a carrier sense multiple access with collision avoidance (CSMA/CA) mechanism. The CSMA/CA mechanism is also known as the Distributed Coordination Function (DCF) of IEEE 802.11MAC, and basically employs a "listen before talk" access mechanism. According to this type of access mechanism, the AP and/or STA may perform Clear Channel Assessment (CCA) of the sensed radio channel or medium during a predetermined time interval (e.g., DCF inter-frame space (DIFS)) before beginning to transmit. As a result of the sensing, if it is determined that the medium is in an idle state, frame transmission is started through the corresponding medium. On the other hand, if it is detected that the medium is occupied or busy, the corresponding AP and/or STA does not start its own transmission, and a delay period (e.g., a random backoff period) for medium access may be set and frame transmission is attempted after waiting. By applying the random backoff period, collisions may be minimized since multiple STAs are expected to attempt frame transmission after waiting different time periods.

In addition, the IEEE 802.11MAC protocol provides a Hybrid Coordination Function (HCF). HCF is based on DCF and Point Coordination Function (PCF). PCF is a synchronous access method based on polling and refers to a method in which all receiving APs and/or STAs periodically poll to receive a data frame. In addition, HCFs have Enhanced Distributed Channel Access (EDCA) and HCF Control Channel Access (HCCA). EDCA is a contention-based access method that provides data frames to a plurality of users, and HCCA uses a non-contention-based channel access method using a polling mechanism. In addition, the HCF includes a medium access mechanism for improving QoS (quality of service) of the wireless LAN, and can transmit QoS data in a Contention Period (CP) and a contention-free period (CFP).

Referring to fig. 4, an operation based on the random backoff period will be described. When the busy/busy medium becomes an idle state, multiple STAs may attempt to transmit data (or frames). As a method of minimizing collision, each of STAs may select a random backoff count separately and attempt transmission after waiting for a corresponding slot time. The random back-off count has a pseudo-random integer value and may be determined as one of values ranging from 0 to CW. Here, CW is a contention window parameter value. The CW parameter is given as CWmin of an initial value, but may take a value twice as large in the case of transmission failure (for example, when ACK for a transmitted frame is not received). When the CW parameter value reaches CWmax, data transmission may be attempted while maintaining the CWmax value until data transmission is successful, and when data transmission is successful, the CWmin value is reset. The values of CW, CWmin and CWmax are preferably set to 2n-1 (n=0, 1, 2).

When the random backoff process starts, the STA continuously monitors the medium in a backoff slot countdown according to the determined backoff count value. When the medium is monitored for occupancy, it stops counting down and waits, and when the medium becomes idle, the remainder of the counting down is restarted.

In the example of fig. 4, when a packet to be transmitted arrives at the MAC of STA3, STA3 may transmit a frame immediately after the acknowledgement medium is idle for as long as DIFS. The remaining STAs monitor and wait for the medium to be occupied/busy. Meanwhile, data to be transmitted may also occur in each of STA1, STA2, and STA5, and when the medium is monitored to be idle, each STA waits for DIFS, and then may perform countdown of backoff slots according to a random backoff count value selected by each STA. Suppose that STA2 selects the minimum backoff count value and STA1 selects the maximum backoff count value. That is, a case is exemplified in which the remaining back-off time of STA5 is shorter than the remaining back-off time of STA1 when STA2 completes the back-off count and starts frame transmission. STA1 and STA5 temporarily stop counting down and wait while STA2 occupies the medium. When the occupancy of STA2 ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and restart the stopped backoff count. That is, frame transmission may begin after the remaining back-off time slot is counted down for the remaining back-off time. Since the remaining back-off time of STA5 is shorter than that of STA1, STA5 starts frame transmission. Data to be transmitted may also occur in STA4 while STA2 occupies the medium. From the perspective of STA4, when the medium becomes idle, STA4 may wait for DIFS, then may perform countdown according to the random backoff count value selected by STA4, and begin transmitting frames. The example of fig. 4 shows a case where the remaining back-off time of STA5 accidentally collides with the random back-off count value of STA 4. In this case, a collision may occur between STA4 and STA 5. When collision occurs, neither STA4 nor STA5 receives ACK, and thus data transmission fails. In this case, STA4 and STA5 may double the CW value, select a random backoff count value, and perform countdown. While the medium is occupied due to transmissions of STA4 and STA5, STA1 waits, and when the medium becomes idle, STA1 waits for DIFS and then starts frame transmission after the remaining backoff time has elapsed.

As in the example of fig. 4, the data frame is a frame for transmitting data forwarded to a higher layer, and may be transmitted after a backoff performed after a DIFS has elapsed since the medium became idle. In addition, the management frame is a frame for exchanging management information that is not forwarded to a higher layer, and is transmitted after performing backoff after IFS such as DIFS or point coordination function IFS (PIFS). As subtype frames of the management frame, there are beacons, association requests/responses, reassociation requests/responses, probe requests/responses, authentication requests/responses, and the like. The control frame is a frame for controlling access to a medium. As subtype frames of the control frame, there are Request To Send (RTS), clear To Send (CTS), acknowledgement (ACK), power save Poll (PS-Poll), block ACK (BlockAck), block ACK request (BlockACKReq), null data packet announcement (NDP announcement), trigger, and the like. If the control frame is not a response frame of a previous frame, it is transmitted after performing backoff after passing through DIFS, and if it is a response frame of a previous frame, it is transmitted without performing backoff after passing through Short IFS (SIFS). The type and subtype of a frame may be identified by a type field and a subtype field in a Frame Control (FC) field.

A quality of service (QoS) STA may perform backoff performed after Arbitration IFS (AIFS) (i.e., AIFS [ i ] (where i is a value determined by AC)) for an Access Class (AC) to which a frame belongs, and then may transmit the frame. Here, the frame in which AIFS [ i ] may be used may be a data frame, a management frame, or a control frame instead of a response frame.

As described above, the CSMA/CA mechanism includes virtual carrier sensing in addition to physical carrier sensing where STAs directly sense the medium. Virtual carrier sensing aims to compensate for problems such as hidden node problems that may occur in medium access. For virtual carrier sensing, the MAC of the STA may use a Network Allocation Vector (NAV). The NAV is a value indicating a remaining time until a medium is available to other STAs that are currently using or have access to the medium. Accordingly, the value set to the NAV corresponds to a period in which the STA transmitting the frame plans to use the medium, and during the corresponding period, the STA receiving the NAV value is prohibited from accessing the medium. For example, the NAV may be configured based on the value of the "duration" field of the MAC header of the frame.

In the example of fig. 5, it is assumed that STA1 intends to transmit data to STA2, and STA3 is in a position capable of eavesdropping on some or all of the frames transmitted and received between STA1 and STA 2.

To reduce the possibility of transmission collisions of multiple STAs in a CSMA/CA based frame transmission operation, a mechanism using RTS/CTS frames may be applied. In the example of fig. 5, when transmission of STA1 is being performed, it may be determined that the medium is in an idle state as a result of carrier sensing of STA 3. That is, STA1 may correspond to a hidden node with respect to STA 3. Alternatively, in the example of fig. 5, it may be determined that the carrier sense result medium of STA3 is in an idle state while transmission of STA2 is being performed. That is, STA2 may correspond to a hidden node with respect to STA 3. By exchanging RTS/CTS frames before performing data transmission and reception between STA1 and STA2, STAs outside the transmission range of one of STA1 or STA2 or STAs outside the carrier sense range from the transmission of STA1 or STA3 may not attempt to occupy channels during data transmission and reception between STA1 and STA 2.

Specifically, STA1 may determine whether a channel is being used through carrier sensing. For physical carrier sensing, STA1 may determine that the channel occupies an idle state based on the energy level or signal correlation detected in the channel. In addition, for virtual carrier sensing, STA1 may use a Network Allocation Vector (NAV) timer to determine the channel occupancy state.

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

If STA3 cannot overhear the CTS frame from STA2 but can overhear the RTS frame from STA1, STA3 may set a NAV timer for a frame transmission period (e.g., sifs+cts frame+sifs+data frame+sifs+ack frame) continuously transmitted thereafter using duration information included in the RTS frame. Alternatively, if STA3 can overhear the CTS frame from STA2, although STA3 cannot overhear the RTS frame from STA1, STA3 may set the NAV timer for a frame transmission period (e.g., sifs+data frame+sifs+ack frame) continuously transmitted thereafter using the duration information included in the CTS frame. That is, if STA3 can overhear one or more of the RTS frames or CTS frames from one or more of STA1 or STA2, STA3 may set the NAV accordingly. When the STA3 receives a new frame before the NAV timer expires, the STA3 may update the NAV timer using duration information included in the new frame. STA3 does not attempt channel access until the NAV timer expires.

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

By means of instructions or primitives (meaning an aggregation of instructions or parameters) from the MAC layer, the PHY layer may prepare MAC PDUs (MPDUs) to be transmitted. For example, when a command requesting to start transmission of the PHY layer is received from the MAC layer, the PHY layer switches to a transmission mode, and information (e.g., data) provided from the MAC layer is configured in the form of a frame and transmitted. In addition, when the PHY layer detects a valid preamble of a received frame, the PHY layer monitors a header of the preamble and transmits a command informing the MAC layer of the start of reception of the PHY layer.

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

The basic PPDU frame may include a Short Training Field (STF), a Long Training Field (LTF), a Signal (SIG) field, and a data field. The most basic (e.g., non-High Throughput (HT)) PPDU frame format may be composed of only L-STF (legacy STF), L-LTF (legacy-LTF), SIG field, and data field. In addition, additional (or different types of) STF, LTF, and SIG fields (which will be described later with reference to fig. 7) may be included between the SIG field and the data field according to the type of PPDU frame format (e.g., HT mixed format PPDU, HT greenfield PPDU, VHT (very high throughput) PPDU, etc.).

The STF is a signal for signal detection, automatic Gain Control (AGC), diversity selection, accurate time synchronization, etc., and the LTF is a signal for channel estimation and frequency error estimation. The STF and LTF may be referred to as signals for synchronization and channel estimation of the OFDM physical layer.

The SIG field may include a RATE field and a LENGTH field, etc. The rate field may include information about the modulation and coding rate of the data. The length field may include information about the length of the data. In addition, the SIG field may include parity bits, SIG tail bits, and the like.

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

The MAC PDU is defined according to various MAC frame formats, and a basic MAC frame is composed of a MAC header, a frame body, and a Frame Check Sequence (FCS). The MAC frame may be composed of MAC PDUs and is transmitted/received through a PSDU of a data portion of a PPDU frame format.

The MAC header includes a frame control field, a duration/ID field, an address field, etc. The frame control field may include control information required for frame transmission/reception. The duration/ID field may be set to a time for transmitting a corresponding frame or the like. For details of the sequence control, qoS control and HT control subfields of the MAC header, refer to the IEEE 802.11 standard document.

The Null Data Packet (NDP) frame format means a frame format that does not include a data packet. That is, the NDP frame refers to a frame format including a Physical Layer Convergence Procedure (PLCP) header portion (i.e., STF, LTF, and SIG fields) and not including the remaining portion (i.e., data field) in a common PPDU frame format. NDP frames may also be referred to as short frame formats.

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

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

Examples of the VHT PPDU format (IEEE 802.11 ac) additionally include a VHT SIG-A, VHT-STF, a VHT-LTF, and a VHT-SIG-B field for the basic PPDU format.

Examples of the HE PPDU format (IEEE 802.11 ax) additionally include repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF, packet Extension (PE) fields with respect to the basic PPDU format. According to a detailed example of the HE PPDU format, some fields may be excluded or their lengths may vary. For example, the HE-SIG-B field is included in a HE PPDU format of a multi-user (MU), and the HE-SIG-B field is not included in a HE PPDU format of a Single User (SU). In addition, the HE Trigger (TB) -based PPDU format does not include HE-SIG-B, and the length of the HE-STF field may vary to 8us. Ext> theext> extendedext> rangeext> (ext> HEERext>)ext> SUext> PPDUext> formatext> doesext> notext> includeext> theext> HEext> -ext> SIGext> -ext> Bext> fieldext>,ext> andext> theext> lengthext> ofext> theext> HEext> -ext> SIGext> -ext> Aext> fieldext> mayext> varyext> toext> 16ext> usext>.ext>

Referring to fig. 8 to 10, a Resource Unit (RU) defined in the wireless LAN system will be described. An RU may include a plurality of subcarriers (or tones). RU may be used when transmitting signals to a plurality of STAs based on the OFDMA scheme. In addition, RU may be defined even when a signal is transmitted to one STA. RU may be used for data field, STF, LTF, etc. of PPDU.

As shown in fig. 8 to 10, RU corresponding to different numbers of tones (i.e., subcarriers) are used to construct some fields of 20MHz, 40MHz, or 80MHz X-PPDU (X is HE, EHT, etc.). For example, resources may be allocated in RU units shown for X-STF, X-LTF, and data fields.

Fig. 8 is a diagram illustrating exemplary allocation of Resource Units (RUs) used on a 20MHz band.

As shown at the top of fig. 8, 26-units (i.e., units corresponding to 26 tones) may be allocated. The 6 tones may be used as guard bands in the leftmost band of the 20MHz band, and the 5 tones may be used as guard bands in the rightmost band of the 20MHz band. In addition, 7 DC tones are inserted into the center frequency band (that is, the DC band), and 26-units corresponding to each of 13 tones may exist on the left and right sides of the DC band. In addition, other frequency bands may be allocated 26-element, 52-element, and 106-element. Each unit may be allocated for a STA or a user.

The RU allocation of fig. 8 is used not only in the case of multi-user (MU) but also in the case of Single User (SU), and in this case, one 242-unit may be used, as shown in the bottom of fig. 8. In this case, three DC tones may be inserted.

In the example of fig. 8, RU of various sizes, that is, 26-RU, 52-RU, 106-RU, 242-RU, etc., are illustrated, but the specific sizes of these RU may be reduced or enlarged. Thus, in the present disclosure, the specific size of each RU (i.e., the number of corresponding tones) is exemplary, and not limiting. In addition, the number of RUs may vary according to the size of RUs within a predetermined bandwidth (e.g., 20MHz, 40MHz, 80MHz, 160MHz, 320MHz, etc.) in the present disclosure. In the examples of fig. 9 and/or 10, which will be described below, the fact that the size and/or number of RUs may vary is the same as the example of fig. 8.

Fig. 9 is a diagram illustrating exemplary allocation of Resource Units (RUs) used on a 40MHz band.

Just as various sizes of RU are used in the example of fig. 8, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. may also be used in the example of fig. 9. In addition, 5 DC tones may be inserted at the center frequency, 12 tones may be used as guard bands in the leftmost band of the 40MHz band, and 11 tones may be used as guard bands in the rightmost band of the 40MHz band.

In addition, as shown, 484-RU may be used when used for a single user.

Fig. 10 is a diagram illustrating exemplary allocation of Resource Units (RUs) used on an 80MHz band.

As with the various sizes of RU used in the examples of fig. 8 and 9, 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc. may also be used in the example of fig. 10. In addition, in the case of an 80MHz PPDU, RU allocations of the HE PPDU and the EHT PPDU may be different, and the example of fig. 10 shows an example of RU allocation for the 80MHz EHT PPDU. The scheme in which 12 tones are used as guard bands in the leftmost band of the 80MHz band and 11 tones are used as guard bands in the rightmost band of the 80MHz band is the same as in the HE PPDU and the EHT PPDU in the example of fig. 10. Unlike the HE PPDU in which 7 DC tones are inserted into the DC band and one 26-RU corresponding to each of 13 tones exists on the left and right sides of the DC band, in the EHT PPDU, 23 DC tones are inserted into the DC band and one 26-RU exists on the left and right sides of the DC band. Unlike the HE PPDU in which one null subcarrier exists between 242-RUs instead of the center band, five null subcarriers exist in the EHT PPDU. In the HE PPDU, one 484-RU does not include null subcarriers, but in the EHT PPDU, one 484-RU includes 5 null subcarriers.

In addition, as shown, 996-RU may be used when used for a single user, and in this case, 5 DC tones are inserted as in the HE PPDU and EHT PPDU.

In fig. 10, an EHT PPDU at 160MHz may be configured with a plurality of 80MHz sub-blocks. The RU allocation for each 80MHz sub-block may be the same as the RU allocation of the 80MHz EHT PPDU of fig. 10. If the 80MHz sub-block of the 160MHz or 320MHz EHT PPDU is not punctured (and the entire 80MHz sub-block is used as part of an RU or RUs (MRUs), the 996-RU of FIG. 10 may be used by the 80MHz sub-block.

Here, the MRU corresponds to a set of subcarriers (or tones) made up of multiple RUs, and the multiple RUs making up the MRU may be RUs having the same size or RUs having different sizes. For example, a single MRU may be defined as 52+26-tones, 106+26-tones, 484+242-tones, 996+484-tones, 996+484+242-tones, 2×996+484-tones, 3×996-tones, or 3×996+484-tones. Here, the plurality of RUs constituting one MRU may correspond to a small-size (e.g., 26, 52, or 106) RU or a large-size (e.g., 242, 484, or 996) RU. That is, one MRU including a small size RU and a large size RU may not be configured/defined. In addition, a plurality of RUs constituting one MRU may or may not be contiguous in the frequency domain.

When an 80MHz sub-block includes an RU of less than 996 tones or a portion of an 80MHz sub-block is punctured, the 80MHz sub-block may use RU allocations other than 996-tone RU.

RU of the present disclosure can be used for Uplink (UL) and/or Downlink (DL) communications. For example, when performing trigger-based UL-MU communication, an STA (e.g., an AP) transmitting a trigger may allocate a first RU (e.g., 26/52/106/242-RU, etc.) to the first STA and a second RU (e.g., 26/52/106/242-RU, etc.) to the second STA through trigger information (e.g., a trigger frame or Trigger Response Schedule (TRS)). Thereafter, the first STA may transmit a first trigger-based (TB) PPDU based on the first RU, and the second STA may transmit a second TB PPDU based on the second RU. The first/second TB PPDU may be transmitted to the AP in the same period of time.

For example, when the DL MU PPDU is configured, an STA (e.g., AP) transmitting the DL MU PPDU may allocate a first RU (e.g., 26/52/106/242-RU, etc.) to the first STA and a second RU (e.g., 26/52/106/242-RU, etc.) to the second STA. That is, a transmitting STA (e.g., AP) may transmit HE-STF, HE-LTF, and data fields for a first STA through a first RU and transmit HE-STF, HE-LTF, and data fields for a second STA through a second RU in one MU PPDU.

Information about allocation of RU may be signaled in HE PPDU format by HE-SIG-B.

Fig. 11 illustrates an example structure of the HE-SIG-B field.

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

The common field may include information about RU assignments (e.g., RU assignments, RU for MU-MIMO assignments, number of MU-MIMO users (STAs), etc.).

The common field may include N x 8 RU allocation subfields. Here, N is the number of subfields, n=1 in case of 20 or 40MHz MU PPDU, n=2 in case of 80MHz MU PPDU, n=4 in case of 160MHz or 80+80MHz MU PPDU, and so on. One 8-bit RU allocation subfield may indicate the size (26, 52, 106, etc.) and frequency location (or RU index) of RU included in the 20MHz band.

For example, if the value of the 8-bit RU allocation subfield is 00000000, this may indicate that nine 26-RUs are allocated in order from leftmost to rightmost in the example of fig. 8, if the value is 00000001, this may indicate that seven 26-RUs and one 52-RU are allocated in order from leftmost to rightmost, and if the value is 00000010, this may indicate that five 26-RUs, one 52-RU and two 26-RUs are allocated in order from leftmost to rightmost.

As an additional example, if the value of the 8-bit RU allocation subfield is 01000y2y1y0, this may indicate that one 106-RU and five 26-RUs are allocated in order from the leftmost side to the rightmost side in the example of fig. 8. In this case, in the MU-MIMO scheme, multiple users/STAs may be allocated to the 106-RU. Specifically, a maximum of 8 users/STAs may be allocated to the 106-RU, and the number of users/STAs allocated to the 106-RU is determined based on 3-bit information (i.e., y2y1y 0). For example, when the 3-bit information (y 2y1y 0) corresponds to a decimal value of N, the number of users/STAs allocated to the 106-RU may be n+1.

Basically, one user/STA may be allocated to each of a plurality of RUs, and different users/STAs may be allocated to different RUs. For RUs greater than a predetermined size (e.g., 106, 242, 484, 996-tone,) multiple users/STAs may be assigned to one RU, and MU-MIMO schemes may be applied for the multiple users/STAs.

The set of user-specific fields includes information on how all users (STAs) corresponding to the PPDU decode their payloads. The user-specific field may contain zero or more user block fields. The non-end user block field includes two user fields (i.e., information to be used for decoding in two STAs). The end user block field contains one or two user fields. Ext> theext> numberext> ofext> userext> fieldsext> mayext> beext> indicatedext> byext> anext> RUext> allocationext> subfieldext> ofext> HEext> -ext> SIGext> -ext> Bext>,ext> theext> numberext> ofext> symbolsext> ofext> HEext> -ext> SIGext> -ext> Bext>,ext> orext> aext> MUext> -ext> MIMOext> userext> fieldext> ofext> HEext> -ext> SIGext> -ext> Aext>.ext> The user-specific fields may be encoded separately from or independent of the public fields.

In the example of fig. 12, assume that the RU allocated subfield has a value of 01000010. This corresponds to the case where y2y1y0=010 in 01000y2y1y 0. 010 corresponds to 2 in decimal (i.e., n=2), and 3 (=n+1) users may be indicated to be allocated to one RU. In this case, one 106-RU and five 26-RUs may be allocated sequentially from the leftmost side to the rightmost side of a specific 20MHz band/channel. Three users/STAs may be allocated to the 106-RU in MU-MIMO. As a result, a total of 8 users/STAs are allocated to the 20MHz band/channel, and the user-specific field of the HE-SIG-B may include 8 user fields (i.e., 4 user block fields). Eight user fields may be assigned to an RU, as shown in fig. 12.

The user field may be constructed based on two formats. The user fields for MU-MIMO assignments may be constructed in a first format and the user fields for non-MU-MIMO assignments may be constructed in a second format. Referring to the example of fig. 12, user fields 1 through 3 may be based on a first format, and user fields 4 through 8 may be based on a second format. The first format and the second format may contain bit information of the same length (e.g., 21 bits).

The user field of the first format (i.e., the format allocated for MU-MIMO) may be constructed as follows. For example, among all 21 bits of one user field, B0-B10 includes identification information of a user (e.g., STA-ID, AID, partial AID, etc.), B11-B14 includes spatial configuration information such as the number of spatial streams corresponding to the user, B15-B18 includes Modulation and Coding Scheme (MCS) information applied to a data field of the corresponding PPDU, B19 is defined as a reserved field, and B20 may include information about the type of coding (e.g., binary Convolutional Coding (BCC) or Low Density Parity Check (LDPC)) applied to the data field of the corresponding PPDU.

The user field of the second format (i.e., the format for non-MU-MIMO allocation) may be constructed as follows. For example, among all 21 bits of one user field, B0-B10 includes identification information (e.g., STA-ID, AID, partial AID, etc.) of a user, B11-B13 includes information on the number of spatial streams (NSTS) applied to a corresponding RU, B14 includes information indicating whether beamforming is performed (or whether a beamforming control matrix is applied), B15-B18 includes Modulation and Coding Scheme (MCS) information applied to a data field of a corresponding PPDU, B19 includes information indicating whether DCM (dual carrier modulation) is applied, and B20 may include information on the coding type (e.g., BCC or LDPC) applied to a data field of a corresponding PPDU.

MCS, MCS information, MCS index, MCS field, etc. used in the present disclosure may be indicated by a specific index value. For example, MCS information may be indicated as index 0 to index 11. The MCS information includes information about constellation modulation types (e.g., BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, etc.) and coding rates (e.g., 1/2, 2/3, 3/4, 5/6, etc.). Information about the channel coding type (e.g., BCC or LDPC) may be excluded from the MCS information.

The PPDU of fig. 13 may be referred to as various names such as an EHT PPDU, a transmitted PPDU, a received PPDU, a first type or an nth type PPDU. For example, the PPDU or EHT PPDU of the present disclosure may be referred to as various names such as a transmission PPDU, a reception PPDU, a first type or an nth type PPDU. In addition, the EHT PPU may be used in an EHT system and/or a new wireless LAN system that improves the EHT system.

The EHT MU PPDU of fig. 13 corresponds to a PPDU carrying one or more data (or PSDUs) for one or more users. That is, the EHT MU PPDU may be used for SU transmissions and MU transmissions. For example, the EHT MU PPDU may correspond to a PPDU for one receiving STA or a plurality of receiving STAs.

In the EHT TB PPDU of FIG. 13, the EHT-SIG is omitted as compared to the EHT MU PPDU. Upon receiving a trigger (e.g., a trigger frame or TRS) for UL MU transmission, the STA may perform UL transmission based on the EHT TB PPDU format.

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

The subcarrier frequency spacing of the L-STF, L-LTF, L-SIG, RL-SIG, universal signal (U-SIG), EHT-SIG fields (these are referred to as pre-EHT modulation fields) may be set to 312.5kHz. The subcarrier frequency spacing of the EHT-STF, EHT-LTF, data and PE fields (these are referred to as EHT modulation fields) may be set to 78.125kHz. That is, the tone/subcarrier indexes of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG fields may be indicated in units of 312.5kHz, and the tone/subcarrier indexes of the EHT-STF, EHT-LTF, data, and PE fields may be indicated in units of 78.125kHz.

The L-LTF and L-STF of fig. 13 may be constructed identically to the corresponding fields of the PPDUs described in fig. 6 to 7.

The L-SIG field of fig. 13 may be composed of 24 bits and may be used to transmit rate and length information. For example, the L-SIG field includes a 4 bit rate field, a 1 bit reserved bit, a 12 bit length field, a 1 bit parity field, and a 6 bit tail field. For example, the 12-bit length field may include information about the duration or length of the PPDU. For example, the value of the 12-bit length field may be determined based on the type of PPDU. For example, for a non-HT, HT, VHT or EHT PPDU, the value of the length field may be determined to be a multiple of 3. For example, for the HE PPDU, the value of the length field may be determined as a multiple of 3+1 or a multiple of 3+2.

For example, the transmitting STA may apply BCC encoding based on the encoding rate of 1/2 to 24 bits of information of the L-SIG field. Thereafter, the transmitting STA may obtain 48-bit BCC encoded bits. BPSK modulation may be applied to the 48-bit coded bits to generate 48 BPSK symbols. The transmitting STA may map 48 BPSK symbols to any position except for pilot subcarriers (e.g., { subcarrier index-21, -7, +7, +21 }) and DC subcarriers (e.g., { subcarrier index 0 }). As a result, 48 BPSK symbols may be mapped to subcarrier indexes-26 to-22, -20 to-8, -6 to-1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA may additionally map signals of { -1, -1,1} to subcarrier indexes { -28, -27, +27, +28}. The above signals may be used for channel estimation in the frequency domain corresponding to { -28, -27, +27, +28}.

The transmitting STA may construct an RL-SIG that is the same as the L-SIG. For the RL-SIG, BPSK modulation is applied. Based on the existence of the RL-SIG, the receiving STA can recognize whether the received PPDU is a HE PPDU or an EHT PPDU.

After the RL-SIG of FIG. 13, a universal SIG (U-SIG) may be inserted. The U-SIG may be referred to by various names such as a first SIG field, a first SIG, a first type SIG, a control signal field, and a first (type) control signal.

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

For example, with a U-SIG (or U-SIG field), A-bit information (e.g., 52 unencoded bits), a first symbol of the U-SIG (e.g., U-SIG-1) may transmit the first X-bit information (e.g., 26 unencoded bits) in the total A-bit information, and a second symbol of the U-SIG (e.g., U-SIG-2) may transmit the remaining Y-bit information (e.g., 26 unencoded bits) in the total A-bit information. For example, the transmitting STA may obtain 26 uncoded bits included in each U-SIG symbol. The transmitting STA may generate 52 encoded bits by performing convolutional encoding (e.g., BCC encoding) based on a rate of r=1/2, and perform interleaving on the 52 encoded bits. The transmitting STA may generate 52 BPSK symbols allocated to each U-SIG symbol by performing BPSK modulation on the interleaved 52 coded bits. In addition to DC index 0, one U-SIG symbol may be transmitted based on 56 tones (subcarriers) from subcarrier index-28 to subcarrier index +28. The 52 BPSK symbols generated by the transmitting STA may be transmitted based on remaining tones (subcarriers) other than pilot tones-21, -7, +7, and +21.

For example, the a-bit information (e.g., 52 uncoded bits) transmitted by the U-SIG includes a CRC field (e.g., a 4-bit field) and a tail field (e.g., a 6-bit length field). The CRC field and the tail field may be transmitted over a second symbol of the U-SIG. The CRC field may be constructed based on the 26 bits of the first symbol allocated to the U-SIG and the remaining 16 bits of the second symbol other than the CRC/tail field, and may be constructed based on conventional CRC calculation algorithms. In addition, the tail field may be used to terminate trellis diagrams (trellis) of the convolutional decoder, and for example, the tail field may be set to 0.

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

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

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

For example, the version-independent bit of the U-SIG may include information about a transmission opportunity length (TXOP) and information about a BSS color ID.

For example, if the EHT PPDUs are classified into various types (e.g., an EHT PPDU related to SU mode, an EHT PPDU related to MU mode, an EHT PPDU related to TB mode, an EHT PPDU related to extended range transmission, etc.), information about the EHT PPDU type may be included in version-related bits of the U-SIG.

For example, the U-SIG may include information about: 1) a bandwidth field containing information about a bandwidth, 2) a field containing information about an MCS scheme applied to an EHT-SIG, 3) an indication field containing information about whether DCM technology is applied to the EHT-SIG, 4) a field containing information about the number of symbols for the EHT-SIG, 5) a field containing information about whether the EHT-SIG is constructed on all frequency bands, 6) a field containing information about the type of EHT-LTF/STF, and 7) a field indicating the EHT-LTF length and CP length.

Preamble puncturing may be applied to the PPDU of fig. 13. Preamble puncturing may mean transmission of a PPDU in which there is no signal in one or more 20MHz subchannels among bandwidths of the PPDU. Preamble puncturing may be applied to PPDUs that are transmitted to one or more users. For example, the resolution of preamble puncturing may be 20MHz for EHT MU PPDUs in OFDMA transmissions with bandwidths greater than 40MHz and non-OFDMA transmissions with bandwidths of 80MHz and 160 MHz. That is, in the above case, puncturing on subchannels smaller than the 242-tone RU cannot be allowed. In addition, for an EHT MU PPDU in a non-OFDMA transmission with a bandwidth of 320MHz, the resolution of preamble puncturing may be 40MHz. That is, puncturing cannot be allowed for sub-channels less than 484-tone RU in the 320MHz bandwidth. In addition, preamble puncturing cannot be applied to the primary 20MHz channel in the EHT MU PPDU.

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

For example, the U-SIG and the EHT-SIG may include information regarding preamble puncturing based on the following methods. If the bandwidth of the PPDU exceeds 80MHz, the U-SIG may be independently constructed in units of 80 MHz. For example, if the bandwidth of the PPDU is 160MHz, the PPDU may include a first U-SIG for a first 80MHz band and a second U-SIG for a second 80MHz band. In this case, the first field of the first U-SIG includes information about a 160MHz bandwidth, and the second field of the first U-SIG includes information about preamble puncturing applied to the first 80MHz band (i.e., information about a preamble puncturing pattern). In addition, the first field of the second U-SIG includes information about a 160MHz bandwidth, and the second field of the second U-SIG includes information about preamble puncturing applied to the second 80MHz band (i.e., information about a preamble puncturing pattern). The EHT-SIG after the first U-SIG may include information about preamble puncturing applied to the second 80MHz band (i.e., information about a preamble puncturing pattern), and the EHT-SIG after the second U-SIG may include information about preamble puncturing applied to the first 80MHz band (i.e., information about a preamble puncturing pattern).

Additionally or alternatively, the U-SIG and EHT-SIG may include information regarding preamble puncturing based on the following methods. The U-SIG may include information about preamble puncturing for all frequency bands (i.e., information about preamble puncturing patterns). That is, the EHT-SIG does not include information about preamble puncturing, and only the U-SIG may include information about preamble puncturing (i.e., information about preamble puncturing pattern).

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

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

The EHT-SIG may include the technical features of the HE-SIG-B described by FIGS. 11 and 12. For example, as in the example of fig. 8, the EHT-SIG may include a common field and a user-specific field. The common field of the EHT-SIG may be omitted and the number of user-specific fields may be determined based on the number of users.

As in the example of fig. 11, the common field of the EHT-SIG and the user-specific field of the EHT-SIG may be separately encoded. One user block field included in the user-specific field may contain information for two user fields, but the last user block field included in the user-specific field may contain one or two user fields. That is, one user block field of the EHT-SIG may contain a maximum of two user fields. As in the example of fig. 12, each user field may be associated with a MU-MIMO allocation or a non-MU-MIMO allocation.

In the same manner as in the example of fig. 11, the common field of the EHT-SIG may include CRC bits and tail bits. The length of the CRC bits may be determined to be 4 bits, and the length of the tail bits is determined by 6 bits and may be set to 000000.

As in the example of fig. 11, the common field of the EHT-SIG may include RU allocation information. The RU allocation information may be information about locations of RU to which a plurality of users (i.e., a plurality of receiving STAs) are allocated. RU allocation information may be configured in 9-bit (or N-bit) units.

A mode may be supported in which the common field of the EHT-SIG is omitted. The mode in which the common field of the EHT-SIG is omitted may be referred to as a compressed mode. When the compressed mode is used, multiple users (i.e., multiple receiving STAs) of the EHT PPDU may decode the PPDU (e.g., a data field of the PPDU) based on non-OFDMA. That is, multiple users of the EHT PPDU may decode PPDUs (e.g., data fields of PPDUs) received through the same frequency band. When the non-compressed mode is used, multiple users of the EHT PPDU may decode the PPDU (e.g., a data field of the PPDU) based on the OFDMA. That is, multiple users of the EHT PPDU may receive the PPDU (e.g., a data field of the PPDU) through different frequency bands.

The EHT-SIG may be constructed based on various MCS schemes. As described above, information related to an MCS scheme applied to the EHT-SIG may be included in the U-SIG. The EHT-SIG may be constructed based on a DCM scheme. The DCM scheme may reuse the same signal on both subcarriers to provide an effect similar to frequency diversity, reduce interference, and improve coverage. For example, modulation symbols applying the same modulation scheme may be repeatedly mapped on the available tones/subcarriers. For example, modulation symbols (e.g., BPSK modulation symbols) applying a particular modulation scheme may be mapped to a first consecutive half tone (e.g., 1 st to 26 th tones) among N data tones (e.g., 52 th data tones) allocated for the EHT-SIG, and modulation symbols (e.g., BPSK modulation symbols) applying the same particular modulation scheme may be mapped to remaining consecutive half tones (e.g., 27 th to 52 th tones). That is, the modulation symbol mapped to the 1 st tone and the modulation symbol mapped to the 27 th tone are identical. As described above, information regarding whether the DCM scheme is applied to the EHT-SIG (e.g., 1-bit field) may be included in the U-SIG. The EHT-STF of fig. 13 may be used to enhance Automatic Gain Control (AGC) estimation in a MIMO environment or an OFDMA environment. The EHT-LTF of fig. 13 may be used to estimate channels in a MIMO environment or an OFDMA environment.

Information about the type of the STF and/or LTF, including information about a Guard Interval (GI) applied to the LTF, may be included in the U-SIG field and/or the EHT-SIG field of fig. 13.

The PPDU of fig. 13 (i.e., EHT PPDU) may be constructed based on the example of RU allocation of fig. 8 to 10.

For example, an EHT PPDU transmitted on a 20MHz band, that is, a 20MHz EHT PPDU may be constructed based on the RU of fig. 8. That is, as shown in fig. 8, RU positions of an EHT-STF, an EHT-LTF, and a data field included in the EHT PPDU may be determined. The EHT PPDU transmitted on the 40MHz band, that is, the 40MHz EHT PPDU may be constructed based on the RU of fig. 9. That is, as shown in fig. 9, RU positions of an EHT-STF, an EHT-LTF, and a data field included in the EHT PPDU may be determined.

The EHT PPDU transmitted on the 80MHz band, that is, the 80MHz EHT PPDU may be constructed based on the RU of fig. 10. That is, as shown in fig. 10, RU positions of an EHT-STF, an EHT-LTF, and a data field included in the EHT PPDU may be determined. The tone plan for 80MHz in fig. 10 may correspond to two repetitions of the tone plan for 40MHz in fig. 9.

The tone plan for 160/240/320MHz may be configured in the form of a pattern that repeats fig. 9 or fig. 10 a plurality of times.

The PPDU of fig. 13 may be identified as an EHT PPDU based on the following method.

The receiving STA may determine the type of the received PPDU as an EHT PPDU based on the following. For example, when 1) a first symbol after the L-LTF signal of the received PPDU is BPSK, 2) RL-SIG of L-SIG of the repeatedly received PPDU is detected, and 3) a result of applying modulo 3 calculation to a value of a length field of the L-SIG of the received PPDU (i.e., a remainder after division by 3) is detected as 0, the received PPDU may be determined as an EHT PPDU. When the received PPDU is determined as an EHT PPDU, the receiving STA may determine the type of the EHT PPDU based on bit information included in a symbol after the RL-SIG of fig. 13. In other words, the receiving STA may determine that the received PPDU is an EHT PPDU based on 1) a first symbol (BSPK) after the L-LTF signal, 2) an RL-SIG adjacent to and identical to the L-SIG field, and 3) an L-SIG including a length field in which a result of applying modulo 3 is set to 0.

For example, the receiving STA may determine the type of the received PPDU as the HE PPDU based on the following. For example, when 1) the first symbol after the L-LTF signal is BPSK, 2) RL-SIG that repeats the L-SIG is detected, and 3) the result of applying modulo 3 to the length value of the L-SIG is detected as 1 or 2, the received PPDU may be determined as the HE PPDU.

For example, the receiving STA may determine the type of the received PPDU as non-HT, and VHT PPDUs based on the following. For example, when 1) the first symbol following the L-LTF signal is BPSK and 2) no RL-SIG of the repeated L-SIG is detected, the received PPDU may be determined as a non-HT, and VHT PPDU.

In addition, when the receiving STA detects the RL-SIG that repeats the L-SIG in the received PPDU, it may determine whether the received PPDU is a HE PPDU or an EHT PPDU. In this case, if a rate (6 Mbps) check fails, the received PPDU may be determined as a non-HT, or VHT PPDU. If the rate (6 Mbps) checksum parity passes, when the result of applying modulo 3 to the length value of the L-SIG is detected as 0, the received PPDU may be determined as an EHT PPDU, and when the result of the length mod3 is not 0, it may be determined as an HE PPDU.

The PPDU of fig. 13 may be used to transmit and receive various types of frames. For example, the PPDU of fig. 13 may be used to (simultaneously) transmit and receive one or more of a control frame, a management frame, or a data frame.

The trigger frame may allocate resources for at least one TB PPDU transmission and request the TB PPDU transmission. The trigger frame may also include other information required by the STA in response to which the STA transmits the TB PPDU. The trigger frame may include common information and user information list fields in the frame body.

The common information field may include information commonly applied to at least one TB PPDU transmission of a trigger frame request, e.g., a trigger type, UL length, whether there are subsequent trigger frames (e.g., more TFs), whether Channel Sensing (CS), UL Bandwidth (BW), etc. Fig. 14 exemplarily shows EHT variant common information field formats.

The trigger type subfield of 4-bit size may have a value from 0 to 15. Wherein the values of the trigger type subfields 0, 1, 2, 3, 4, 5, 6, and 7 are defined to correspond to basic beamforming report poll (BFRP), multi-user block acknowledgement request (MU-BAR), multi-user request to send (MU-RTS), buffer Status Report Poll (BSRP), multicast with retry (GCR) MU-BAR, bandwidth Query Report Poll (BQRP), and NDP Feedback Report Poll (NFRP), and the values of 8-15 are defined to be reserved.

Among the common information, the trigger-related common information subfield may include information selectively included based on the trigger type.

A special user information field may be included in the trigger frame. The special user information field does not include user specific information but includes extended common information not provided in the common information field.

The user information list includes at least 0 user information fields. Fig. 14 exemplarily shows an EHT variant user information field format.

It indicates that the AID12 subfield is basically a user information field of the STA having a corresponding AID. In addition, when the AID12 field has a predetermined specific value, it may be used for other purposes, including allocation of a Random Access (RA) -RU or configuration in the form of a special user information field. The special user information field is a user information field that does not include user specific information but includes extended common information not provided in the common information field. For example, a special user information field may be identified by AID12 value 2007, and a special user information field flag subfield in the public information field may indicate whether the special user information field is included.

The RU allocation subfield may represent the size and location of the RU/MRU. For this purpose, the RU allocation subfield may be interpreted with PS160 (primary/secondary 160 MHz) subfield of the user information field, UL BW subfield of the common information field, etc.

Sensing correlation establishment

WLAN sensing may include an STA acquiring sensing measurements of a channel between a corresponding STA and at least one other STA. For example, a first STA may transmit a signal for sensing purposes and a second STA may receive a signal affected by the target and measure a channel based thereon. The second STA may transmit the sensing measurement result to the first STA, and the first STA may identify the target based on the measurement result.

The WLAN sensing process may include stages of capability advertisement and negotiation, setup, sensing, and tear down.

The capability advertisement and negotiation process may include exchanging capability information of the sensing-related stations and establishing an association. By doing so, the STA can determine whether sensing is possible, whether there is appropriate sensing capability, and the like, and perform association based thereon. This process may also be referred to as a discovery and association process.

The setup process may include negotiations about the role of each STA related to sensing and parameters to be used in the sensing process. The negotiated roles and parameters may be used in the sensing session prior to tear down. This negotiation step may or may not be included. In addition, the setup process may also include grouping STAs if desired.

Basically, the setup process can be divided into a sensing session setup and a sensing measurement setup. In other words, after performing a sensing session establishment that forms a session between STAs, a sensing measurement establishment that negotiates a sensing measurement and a specific operating parameter (e.g., measurement establishment ID, role, etc.) may be performed.

The sensing process may include feedback of the sensing signal transmitted by the STA, the receiving and measuring of the sensing signal or measurement result passed through (or affected by) the target. The steps of sensing signal transmission or reception, measurement and feedback may be defined as one sensing session. In other words, the sensing process may include measurements and feedback (or reports) during the sensing session. Alternatively, the feedback/reporting process may be included only when necessary.

Basically, the sensing process can be configured based on the measurement instance. For example, multiple measurement instances may be configured by using roles and parameters that establish ID negotiations through measurements. The sensing session may include at least one TXOP. The TXOP may correspond to a measurement instance, or one TXOP may include multiple measurement instances.

The tear-down process may include a negotiation step for resetting the negotiated roles and parameters and starting the sensing session again. This process may or may not be included depending on whether or not a negotiation step is present.

To express the same meaning differently, the sensing process may include at least one of a sensing session establishment, a sensing measurement establishment, at least one sensing measurement instance, a sensing measurement establishment end (or tear down), or a sensing session end (or tear down).

The roles of STAs performing WLAN sensing operations may be defined as follows.

The sensing initiator is the STA that initiates the WLAN sensing session.

The sensing responders are STAs that participate in a WLAN sensing session initiated by the sensing initiator.

The sensing transmitter is a STA that transmits a signal (or PPDU) for sensing measurement in a sensing session.

The sensing receiver is an STA that receives a signal (PPDU) transmitted by a sensing transmitter and performs sensing measurement.

For example, the sensing sender is not necessarily the sensing initiator. In other words, the role of the sensing sender may be performed separately from (or regardless of) initiating or participating in the sensing session. In addition, the plurality of STAs may sequentially perform the role of a sensing transmitter, or may perform the role of a receiver receiving a sensing signal transmitted by another STA.

In addition, the STA may perform the role of a sensing initiator/responder/sender/receiver without distinguishing between P STA and non-AP STA.

Hereinafter, specific examples of sensing correlation establishment according to the present disclosure are described. The sensing related establishment may include at least one of a sensing session establishment or a sensing measurement establishment. In other words, unless explicitly distinguished in the following examples, specific examples of the sensing-related establishment procedure may be applied to the sensing session establishment procedure, to the sensing measurement establishment procedure, or to both the sensing session establishment procedure and the sensing measurement establishment procedure.

For example, in the sensing correlation establishment process, the request and the response may be performed in a trigger-based manner. The present disclosure is not limited by the trigger-based request response method, and includes examples in which various parameters described later are included in a request frame and/or a response frame in another set-up-related request and response process.

In addition, the STA is not limited to a non-AP STA or an AP STA unless specifically specified. In addition, in the present disclosure, STAs capable of sensing (or having sensing correlation capability) may be expressed as SENS STAs, a sensing correlation setup request may be expressed as a SENS request, an STA transmitting the SENS request may be expressed as SENS RQSTA, a sensing correlation setup response may be expressed as a SENS response, and an STA transmitting the SENS response may be expressed as SENS RPSTA. In some implementations, SENS RQSTA can be referred to as a first STA and SENS RPSTA can be referred to as a second STA. Here, the scope of the present disclosure is not limited by these names.

At S1510, the first STA may transmit a setup request frame to the second STA.

The setup request frame may include information related to the role of the second STA. The information related to the role of the second STA may indicate a sensing transmitter role of the second STA, a sensing receiver role of the second STA, or both the sensing transmitter role and the sensing receiver role of the second STA.

The setup request frame may further include measurement setup identification Information (ID). Based on this, the second STA may correspond to a sensing responder corresponding to the measurement setup ID. The first STA may correspond to a sensing initiator.

At S1520, the first STA may receive a setup response frame from the second STA.

The setup response frame may include at least one setup response frame transmitted by at least one STA including the second STA.

For example, the setup request frame may include trigger related information, or the trigger frame may be transmitted from the first STA after the setup request frame. In this case, at least one setup response frame may be simultaneously transmitted from at least one STA (including the second STA).

For example, each of at least one STA (including the second STA) receiving the establishment request frame may separately transmit the establishment response frame through a separate backoff after the CTS transmission. Alternatively, each of the at least one STA (including the second STA) that receives the establishment request frame may receive the poll frame from the first STA and separately transmit the poll-based response frame.

In addition, the setup response frame may include information related to the role of the second STA. The information related to the role of the second STA may indicate a sensing transmitter role of the second STA, a sensing receiver role of the second STA, or both the sensing transmitter role and the sensing receiver role of the second STA.

In S1510 and S1520, when the information related to the role of the second STA indicates at least a sensing receiver role of the second STA (i.e., indicates a sensing receiver role or indicates both a sensing transmitter role and a sensing receiver role), sensing measurement report related information may be included in the establishment request frame. Alternatively, when the information related to the role of the second STA indicates at least a sensing receiver role of the second STA, sensing measurement report related information may be included in the setup response frame. Alternatively, when the information related to the role of the second STA indicates at least a sensing receiver role of the second STA, the sensing measurement report related information may be included in the establishment request frame and the establishment response frame.

Here, the sensing measurement report related information may include information indicating a sensing measurement report type (e.g., whether the sensing measurement report type includes a type related to Channel State Information (CSI) or another report type, or a CSI type including a specific unit, etc.).

At S1610, the second STA may receive a setup request frame from the first STA.

At S1620, the second STA may transmit a setup response frame to the first STA.

Since specific details of S1610 and S1620 are the same as those described with reference to the example of fig. 15, duplicate descriptions are omitted.

Hereinafter, specific examples of the sensing correlation establishment operation of the present disclosure are described.

In the present disclosure, sensing related establishment (e.g., sensing session establishment and/or sensing measurement establishment) may be performed by defining and exchanging new negotiation frames. For example, the new negotiation frame may correspond to a negotiation frame newly defined for a specific purpose or use, such as an add block acknowledgement (ADDBA) request frame and an ADDBA response frame agreed for an existing Block ACK (BA).

In the present disclosure, a frame transmitted by an STA that initiates a sensing related setup (e.g., a sensing session setup and/or a sensing measurement setup) may be referred to as a setup request frame (e.g., a Sensing Session (SS) request frame and/or a Sensing Measurement (SM) request frame), and a frame transmitted by an STA in response may be referred to as a setup response frame (e.g., an SS response frame and/or an SM response frame).

For example, a setup request/response frame (e.g., SS request/response frame, SM request/response frame) may be defined as a control frame such as an RTS/CTS frame or an action frame such as an ADDBA request/response frame.

The setup request/response frame may include category, action, and dialog token fields, and may also include elements related to sensed colors and parameters. The size and number of additional elements may be defined in various ways.

The category field may be configured to indicate a particular value of WLAN sensing. For example, a particular value may be defined as 32, which does not conflict with the candidate value of the existing category field, although the scope of the present disclosure is not limited in this respect.

The action field may be configured to correspond to a value of the sensed action. If it can be configured to correspond to the value of the detailed action within the sense action, the values 0, 1, 2, and 3 of the action field can be defined to correspond to SS request, SS response, SM request, and SM response, respectively. The value of the additional action field and the entry indicated by the corresponding value may be defined in various ways. In this way, the purpose of the action frame (e.g., SS or SM) and request/response frame may be classified or specified according to the value of the action field.

This example proposes four action frames, but when two request/response frames have a common format and whether there are some fields that are different, only one action frame may be defined without dividing the request/response (e.g., SM setup frame or SS setup frame). In this case, a type field may also be included in the frame to distinguish between requests/responses. For example, a request field is defined in a corresponding frame, and if the value of the corresponding field is 1, an SM request frame (or SS request frame) may be represented, and if the value is 0, an SM response frame (or SS response frame) may be represented.

As an additional example, in order to reduce the overhead of the action field, the above request field and a field indicating the SS or SM may be additionally defined. Since this approach requires that the frame formats for SS setup and SM setup will be the same, the overhead may be greater for SS setup request/response frames that require relatively less information.

In the example of fig. 18, SM requests/responses are shown as an example of sensing correlation establishment, but SS requests/responses may also be performed in a similar manner.

As an example of (a) of fig. 18, when the SENS STA1 (SENS RQSTA) transmits an SM request through a backoff, the SENS STA2 (SENS RPSTA) can perform negotiation for sensing by transmitting an SM response with the backoff. In addition, as in the example of (b) of fig. 18, the receiving STA may respond with an ACK for each frame. In addition, as in the example of (c) of fig. 18, if the SENS STA2 performs processing in SIFS and can respond to negotiation after receiving the SM request from the SENS STA1, a SENS response may be transmitted instead of ACK.

In the sensing correlation establishment procedure as described above, it may be assumed that a plurality of STAs perform sensing establishment with STA 1. In this case, when a plurality of STAs can simultaneously transmit a response (i.e., SENS response) with respect to one request (i.e., SENS request) from STA1, the time required for the setup process can be reduced, and thus an efficient setup process can be performed. To this end, in the present disclosure, examples of trigger-based sensing correlation establishment (e.g., SS establishment and/or SM establishment) may be applied to the response of at least one STA.

The description is made by using SM establishment as an example of a sensing-related establishment procedure to which a response method described later is applied, but the same content can also be applied to SS establishment.

Method 1

A sensing correlation setup response may be sent on a triggered basis. For example, a sensing correlation setup request may be transmitted by using a trigger frame, and in response thereto, a sensing correlation setup response frame may be transmitted.

For example, a sensing request variant may be defined as one type of trigger frame. The sensing request trigger frame may basically include information for transmission of a response frame (e.g., RU allocation, bandwidth, power, etc.) like the basic trigger frame. The sensing request trigger frame may additionally include specific information for sensing the establishment of the correlation.

For example, the information for the sensing correlation setup may be transmitted by using existing reserved bits of the common information field to include common information for all STAs for the sensing correlation setup. In addition, information for sensing correlation establishment may be transmitted by using a trigger correlation common information field.

For example, to transmit independent setup related request information for each STA, an existing reserved bit of the user information field may be used. In addition, information for sensing the establishment of the correlation may be transmitted by using a trigger correlation user information field.

Referring to fig. 19 (a), an SM request frame using a trigger frame transmitted by STA 1 may include IDs of STA2 and STA3, RU allocation information, and the like. STA2 and STA3 receiving the SM request frame may transmit the SM response frame through the allocated RU1 and RU2, respectively.

The method may be applied to STAs with the capability to trigger frames (e.g., STAs supporting 802.11ax or higher technologies).

Method 2

The sensing correlation establishment response may be sent based on the CTS. For example, a STA that receives a sensing-related setup request may indicate acceptance or rejection of the setup request by whether to send its CTS frame.

Similar to method 1, the STA receiving the sensing-related setup request takes time to process the SM request and generate the SM response frame, and thus immediate response (e.g., response frame transmission after SIFS time after receiving the request frame) may be difficult. Thus, instead of transmitting a response frame including specific parameters of the receiving STA for a sensing-related setup request frame (e.g., a sensing-related setup request frame of a trigger frame format in method 1), a CTS-to-self (CTS-to-self) frame may be transmitted in response to only whether the request is accepted or rejected.

Since the CTS or CTS-to-self frame may not include information indicating acceptance or rejection of the sensing-related setup request, the requesting STA may distinguish whether it is accepted based on whether the CTS or CTS-to-self frame is received.

For example, as in (c) of fig. 19, an STA that correctly receives the sensing-related request frame may transmit a CTS or CTS-to-self frame when accepting the corresponding request, and may not transmit a CTS or CTS-to-self frame when rejecting the corresponding request. Thus, the STA transmitting the sensing-related request frame may determine that the STA expecting the response refuses the request when the CTS or CTS-to-self frame is not received.

When the channel is occupied (or busy), the sensing response STA may not transmit a CTS or CTS-to-self frame. In this case, the requesting STA may not distinguish whether the sensing response STA refuses the sensing-related establishment request or whether the channel is occupied, but there is an advantage in that the processing load of the sensing response STA is reduced, and if necessary, may be supplemented by a method in which the requesting STA transmits the request frame again.

Method 3

The sensing correlation setup response may be sent in a delayed manner. For example, an STA that receives a transmission correlation establishment request may immediately transmit a CTS or CTS-to-self frame as a response, and transmit a (delayed) sensing correlation establishment response frame through a backoff process.

Method 3 may correspond to a tradeoff of method 1 and method 2. For example, when it is difficult to immediately respond with a setup response frame, as in (c) of fig. 19, STAs that receive a request may transmit a CTS or CTS to their own frame, which means that they will transmit an SM response as an immediate response to the setup request frame (e.g., after SIFS time after receiving the request frame). After that, by the backoff process, the SM response frame can be transmitted.

If the STA has processing capability to generate and transmit a setup response frame immediately after receiving the setup request frame (e.g., after SIFS time), the setup response frame may be immediately transmitted without transmitting a CTS frame.

Since the response frame should send CTS/CTS to itself frame and the sensing-related setup response frame, method 3 increases overhead, but it can guarantee enough processing time. If the SM request uses MU-RTS/CTS mechanism, it may be difficult to distinguish which STA responds to CTS for STAs that simultaneously transmit CTS over one 20MHz channel in the CTS response.

Method 4

A sensing correlation setup response may be sent based on the poll. For example, in method 3, the sensing response STA transmits a response frame in a backoff manner through channel sensing after transmitting a CTS/CTS to self frame, whereas in method 4, it may transmit the response frame as an immediate response to a poll frame from the requesting STA.

For example, in the example of (d) of fig. 19, after STA1 transmits an SM request, STA 2 and STA 3 may transmit a CTS, and in response to a poll from STA1, STA 2 may transmit an SM response, and in response to a poll from STA1, STA 3 may transmit an SM response.

The overhead may be increased compared to the trigger-based setup response method because the requesting STA should attempt channel access for polling of each sensing responding STA, but the sensing-related setup procedure may also be applied to STAs that do not support trigger frames.

Method 5

Unlike the method in which the sensing-related setup request frame is included in the trigger frame (or defined as the type of trigger frame) in the method 1, according to this method, the sensing-related setup request frame and the trigger frame can be defined, respectively.

In other words, the trigger frame is basically used to trigger the sensing-related setup response frames from a plurality of STAs at the same time, and the sensing-related setup request frames may be separately transmitted before the trigger frame.

The sensing correlation setup request frame may include information/parameters, etc. for sensing correlation setup, and the trigger frame may include information/parameters, etc. for transmission of the response frame. In other words, the trigger frame does not include information related to the sensing request, and may be used to trigger a sensing response frame. It is necessary to guarantee the processing time for the STA to transmit the sensing response frame.

If the sensing correlation setup responders cannot ensure sufficient processing time (e.g., frame decoding and frame generation) after receiving the sensing correlation setup request frame, they may not send the sensing correlation setup response frame as an immediate response to the sensing correlation setup request frame.

Therefore, the later-described sensing-related setup request/response-related information/parameter/field is not included in the sensing-related setup request frame, the trigger frame type, but is included in the sensing-related setup request frame, a new action frame (e.g., SENS request frame).

In a new type of sensing-related setup request frame, there may be no common information field and no user information field. For example, the SENS request frame may include information common to all STAs, and further include a discrimination field that delivers independent/separate information to each STA using a STA ID (e.g., partial AID).

In the example of fig. 20 (a), a trigger frame is transmitted after a SENS request frame is transmitted from STA1, and STA 2 and STA 3 receiving it may simultaneously transmit a SENS response frame.

In the example of fig. 20 (b), unlike the example of fig. 20 (a) in which the SENS request frame and the trigger frame are transmitted within one TXOP, the SENS request frame and the trigger frame may be transmitted in different TXOPs. To indicate that the trigger frame triggers a PPDU comprising a SENS response frame, information indicating that the trigger frame is a trigger for a SENS response may be included. For example, a bit that may indicate that it is a trigger for a SENS response may be included in a common information field of a trigger frame or the like.

Information included in a sense-related setup request/response frame

Hereinafter, examples of information/parameters/fields included in the sensing-related setup request and/or response frames are described. Examples of this information/parameter/field may be applied to the above-described sensing-related establishment request/response frame, including the sensing-related establishment response based on trigger, the sensing-related establishment response based on CTS, the delayed sensing-related establishment response method, the sensing-related establishment response method based on polling, the separation method of the sensing-related establishment request frame and the trigger frame, and the like, and may also be applied to other various sensing-related establishment request/response frames.

At least one of the information/parameters/fields described below may be included in the sensing correlation setup request and/or the sensing correlation setup response frame. In addition, the information/parameters/fields included in the sensing-related setup request and/or the sensing-related setup response frame are not limited to the following examples.

1) Measurement setup identification information (measurement setup ID)

2) Roles and roles

3) Sequential order

4) Sensing parameters

Hereinafter, specific examples of each information are described.

1) The measurement setup identification information (or measurement setup ID or group ID) is identification information shared between STAs constituting a sensing session, and WLAN sensing may be performed during the session by using parameters negotiated through the above-described sensing correlation setup process based on the corresponding identification information. In particular, the measurement setup identification information may be included in a common information field, or when the sensing initiator performs sensing-related setup for a plurality of sessions during one frame exchange process, it may be included as a different ID value per measurement setup in the user information field of each STA.

2) The role information may indicate whether the sense initiator (or SENS RQSTA) and the sense responder (or SENS RPSTA) perform a sense sender role or a sense receiver role, or both. For example, the following exemplary modes may be defined, but are not limited thereto.

Mode 1: SENS RQSTA performs the sense sender role and SENS RPSTA performs the sense receiver role.

Mode 2: SENS RQSTA performs the sense receiver role and SENS RPSTA performs the sense sender role.

Mode 3: SENS RQSTA performs the sense sender role and SENS RPSTA performs the sense sender role.

Mode 4: SENS RQSTA performs the sense receiver role and SENS RPSTA performs the sense receiver role.

The mode may be indicated by a sense correlation setup request frame and/or a sense correlation setup response frame. For example, the role requested by the sensing initiator and the role accepted by the sensing responder may be indicated, respectively.

When 4 modes are assumed, character information may be indicated by 2 bits. For example, when the 2-bit values are 00, 01, 10, and 11, mode 1, mode 2, mode 3, and mode 4 may be indicated, respectively. The number of bits of character information may be increased when more modes exist. Alternatively, when only mode 1 and mode 2 exist, the character information may be indicated with 1 bit.

Role information may be included in the user information field to request a different role from each STA in dynamic sensing.

When the sensing initiator is an AP and does not support transmission between non-AP STAs, the AP may perform a sensing transmitter role and all non-AP STAs may perform a sensing receiver role. Alternatively, the AP may perform a sense receiver role and all non-AP STAs may perform a sense sender role. In this case, the signaling overhead may be reduced by including role information in the common information field instead of the user information field.

Through the sense correlation establishment procedure, the RQSTA (or sense initiator) or the RPSTA (or sense responder) may perform both a sense sender role and a sense receiver role. In this case, each STA may be instructed to perform sensing of the sender role, sensing of the receiver role, or both.

For example, when assuming that the AP is an RQSTA and the non-AP STA is an RPSTA, the Downlink (DL) sounding may perform only the sense sender role and the RPSTA performs only the sense receiver role in response to the RQSTA. Uplink (UL) sounding may be responsive to the RQSTA performing only the sense receiver role and the RPSTA performing only the sense sender role. Indicating that both DL and UL sounding may perform both a sense sender role and a sense receiver role in response to the RQSTA, and the RPSTA also performs both a sense sender role and a sense receiver role. As such, the role information may be defined and indicated according to DL/UL sounding, whether to perform DL sounding (i.e., sense whether the responding STA performs the receiver role) and UL sounding (i.e., sense whether the responding STA performs the sender role) may be indicated by 2 bits as follows, and may also indicate to perform both DL sounding and UL sounding (i.e., sense whether the responding STA performs both the sender role and the receiver role).

TABLE 1

Value of	Encoding of character information	SensingResponding to the role of an STA
			0	DL-only detection	Non-sender, receiver
1	UL-only probing	Sender, non-receiver
			2	Both DL and UL sounding	Sender, receiver
3	Reservation of	-

3) The sequence information may indicate a performance sequence of DL/UL sounding. The order information may be included in a common information field. For example, the order information may be generally applied to all STAs participating in sensing. In particular, it may be indicated which probe (i.e., whether the role of the responding STA is sender, receiver, or both) is performed and the order of each probe. For example, the order information may be defined as follows.

TABLE 2

Value of	Coding of sequence information
		0	DL-only detection
1	UL-only probing
		2	First DL sounding and second UL sounding
3	First UL sounding and second DL sounding

When the values of the sequence information are 0 and 1, it may correspond to a case where only one probe is performed, and the values 2 and 3 may correspond to a case where two probes are performed. A method of reducing signaling overhead by considering the correlation of the above 2) role information and 3) sequence information is described below.

When it is indicated in order information that only DL sounding is performed or only UL sounding is performed, there is no need to signal the role information because the role information (i.e., only receiver or only sender) is clearly determined. In other words, the character information is only required when a plurality of detections are performed in the sequence information. Therefore, when the order information and the character information are combined, it can be defined as follows.

When character information is always present, if the value of sequence information is 0, it may be assumed that the value of character information is 0. In other words, when the STA confirms the value of one information without dynamic decoding for each information, it can perform decoding by assuming that the value of the other information is fixed.

When the size of the character information is changed according to the sequence information, the character information may not exist if the value of the sequence information is 0 or 1, and the character information may exist if the value of the sequence information is 2 or 3. Thus, signaling overhead may be reduced.

4) The sensing parameters may include at least one of a parameter set related to transmission of the sensing signal and a parameter set related to measurement/feedback (reporting). The sensed parameters in the examples below are not limited and may indicate some or all of them. When the same parameter set is requested for all STAs, it may be included in a common information field, and when different parameters (e.g., bandwidth, RU, etc.) are applied to each STA, it may be included in a user information field.

Examples of transmission parameters are as follows.

Number of antennas (or spatial streams) used: the number of antennas or the number of spatial streams for transmitting the sensing signal

Signal type: types of sensing signals (e.g., NDP announcement and NDP transmission, NDP-only transmission, transmission of a new type of signal after an announcement frame for a new signal type, transmission of a new type of signal only, etc.)

Signal length: transmission time or length of sensing signal

Measurable bandwidth: in other words, when a TXOP is obtained, it may be reduced to be less than the transmission bandwidth of the first frame to transmit the sense signal;)

Number of sense signals: since the sensing signal may be transmitted a plurality of times in succession, instead of being transmitted a single time, the number of times the sensing signal is transmitted is indicated (for example, it may be indicated how many times NDP is to be transmitted at SIFS intervals).

Sensing Period (SP) related parameters: when only the implicit method is used, the sensing transmitter may transmit the sensing signal without a special request from the sensing initiator. Thus, its sensing period related parameters can be defined. For example, a start time point of the sensing period (e.g., a time difference/offset value based on a next beacon transmission time), a length of the sensing period, a time interval between the sensing periods, and the like may be defined as the sensing period-related parameter. The sensing period related parameters may not be included in the transmission parameter set.

Frequency (or RU) location to be transmitted: frequency/RU location of transmitting the sense signal (e.g., when transmitting the 80MHz sense signal, the sense signal may be transmitted in a primary 40MHz channel or a secondary 40MHz channel among 80MHz bandwidths)

Examples of measurement/feedback (reporting) related parameters are as follows.

Frequency (or RU) location to be sensed: the frequency/RU position of the sense signal should be measured (e.g., when the 80MHz sense signal is received, the sense signal may be measured in either the primary 40MHz channel or the secondary 40MHz channel among the 80MHz bandwidth)

Feedback (or report) type: types of information (e.g., channel State Information (CSI), more particularly, CSI per subcarrier, CSI per bandwidth, CSI per spatial stream, etc.) measured and fed back by receiving a sensing signal

Dynamic indication method

The request/response parameters may be dynamically changed depending on the role information in the above examples. Thus, instead of including all request parameters in one request frame, a dynamic indication method for reducing overhead may be considered.

As an implicit method, it may be determined whether parameters according to roles are included. In other words, depending on the role of the sensing respondent, it may be determined whether the relevant parameter set is included.

For example, when the role of the sensing responder is a receiver (e.g., only the receiver role is performed or both the sender and receiver roles are performed), the measurement/feedback (report) related parameter set may be included in the sensing related setup request/response frame, excluding the parameter set related to the sensing signal transmission.

For example, when the role of the sensing respondent is sender (e.g., only sender role is performed or both sender and receiver roles are performed), the parameter set related to the sensing signal transmission may be included in the sensing-related setup request/response frame, while the measurement/feedback (reporting) related parameter set is excluded.

Whether parameters are included may be determined by an explicit indication. For example, a presence field for each parameter (or parameter set) may be defined.

For example, the transmission parameter set presence subfield may be included in the sensing-related setup request/response frame, and whether or not the transmission parameter set is included may be indicated by a value of the corresponding subfield.

For example, a measurement/feedback (report) related parameter set presence subfield may be included in the sensing correlation setup request/response frame, and whether or not the measurement/feedback (report) related parameter set is included may be indicated by a value of the corresponding subfield.

The above-described embodiments are intended to combine elements and features of the present disclosure in a predetermined form. Individual elements or features should be considered optional unless explicitly mentioned otherwise. Each element or feature may be implemented in a form not combined with other elements or features. Additionally, embodiments of the present disclosure may include combined partial elements and/or features. The order of operations described in embodiments of the present disclosure may be changed. Some elements or features of one embodiment may be included in or substituted for corresponding elements or features of other embodiments. It will be apparent that embodiments may include claims that do not explicitly refer to a relationship in a combination claim or may be included as new claims by modification after application.

It will be apparent to those skilled in the relevant art that the present disclosure may be embodied in other specific forms without departing from the essential characteristics of the disclosure. The foregoing detailed description is, therefore, not to be taken in a limiting sense, and is intended to be illustrative in every respect. The scope of the present disclosure should be determined by a fair interpretation of the accompanying claims, and all changes that come within the meaning and range of equivalency of the disclosure are intended to be embraced therein.

The scope of the present disclosure includes software or machine-executable instructions (e.g., operating systems, application programs, firmware, programs, etc.) that perform operations in accordance with the methods of the various embodiments in an apparatus or computer, as well as non-transitory computer-readable media that cause the software or instructions to be stored and executed in an apparatus or computer. Commands that may be used to program a processing system that performs the features described in this disclosure may be stored in a storage medium or a computer readable storage medium, and the features described in this disclosure may be implemented by using a computer program product that includes such a 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 storage devices, and it may include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. The memory optionally includes one or more storage devices located remotely from the processor. The memory, or alternatively, the non-volatile memory device in the memory, comprises a non-transitory computer-readable storage medium. The features described in this disclosure may be stored in any one of a variety of machine-readable media to control the hardware of the processing system, and may be integrated into software and/or firmware that allows the processing system to interact with other mechanisms using results from embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments/containers.

INDUSTRIAL APPLICABILITY

The method proposed by the present disclosure is mainly described based on an example applied to an IEEE 802.11 based system (5G system), but may be applied to various WLANs or wireless communication systems other than the IEEE 802.11 based system.

Claims

1. A method of performing a sensing correlation setup by a first Station (STA) in a Wireless Local Area Network (WLAN) system, the method comprising the steps of:

transmitting, to a second STA, an establishment request frame including information related to a role of the second STA; and

receiving a setup response frame from the second STA,

wherein the information related to the role of the second STA indicates a sensing transmitter role of the second STA, indicates a sensing receiver role of the second STA, or indicates both a sensing transmitter role and a sensing receiver role of the second STA.

2. The method of claim 1, wherein,

the setup request frame further includes measurement setup identification information,

the second STA is a sensing responder corresponding to the measurement setup identification information.

3. The method of claim 1, wherein,

the setup response frame includes information related to the role of the second STA.

4. The method of claim 1, wherein,

Information related to the role of the second STA is indicated by 2 bits.

5. The method of claim 1, wherein the sensing receiver role of the second STA is indicated based on information related to the role of the second STA, or both the sensing transmitter role and the sensing receiver role of the second STA:

sensing measurement report related information is included in at least one of the setup request frame or the setup response frame.

6. The method of claim 5, wherein,

the sensing measurement report related information includes information indicating a sensing measurement report type.

7. The method of claim 1, wherein,

the setup request frame is a sensing measurement setup request frame,

the setup response frame is a sensing measurement setup response frame.

8. The method of claim 1, wherein,

at least one of the setup request frame or the setup response frame has an action frame format.

9. The method of claim 1, wherein,

the setup response frame includes at least one setup response frame transmitted by at least one STA including the second STA,

the at least one setup response frame is transmitted simultaneously by the at least one STA, or,

The at least one setup response frame is transmitted separately by the at least one STA.

10. A first Station (STA) apparatus for performing a sensing correlation setup in a Wireless Local Area Network (WLAN) system, the apparatus comprising:

at least one transceiver; and

at least one processor coupled to the at least one transceiver,

wherein the at least one processor is configured to:

transmitting, by the at least one transceiver, a setup request frame including information related to a role of the second STA to the second STA; and

receiving a setup response frame from the second STA by the at least one transceiver,

11. A method of performing sensing correlation establishment by a second Station (STA) in a Wireless Local Area Network (WLAN) system, the method comprising the steps of:

receiving, from a first STA, an establishment request frame including information related to a role of the second STA; and

transmitting a setup response frame to the first STA,

12. A second Station (STA) apparatus for performing a sensing related setup in a Wireless Local Area Network (WLAN) system, the apparatus comprising:

at least one transceiver; and

at least one processor coupled to the at least one transceiver,

wherein the at least one processor is configured to:

receiving, by the at least one transceiver, a setup request frame from a first STA including information related to a role of the second STA; and

transmitting a setup response frame to the first STA through the at least one transceiver,

13. A processing device configured to control a Station (STA) in a Wireless Local Area Network (WLAN) system, the processing device comprising:

At least one processor; and

at least one computer memory operatively connected to the at least one processor and storing instructions for performing the method of claim 1 based on execution by the at least one processor.

14. At least one non-transitory computer-readable medium storing at least one instruction, wherein,

the at least one instruction, by execution by at least one processor, controls a Station (STA) apparatus to perform the method of claim 1 in a Wireless Local Area Network (WLAN) system.