Method and apparatus for performing improved subchannel selective transmission operation in wireless LAN system

Abstract

Disclosed are a method and an apparatus for performing an improved subchannel selective transmission operation in a wireless LAN system. A method performed by a first station (STA) in a wireless LAN system according to an embodiment of the present disclosure may comprise the steps of: receiving, from a second STA, a frame including at least one field related to a channel for a subchannel selective transmission (SST) operation; and performing the SST operation in the channel based on the at least one field. Here, the at least one field includes a first field including bitmap information related to activation of the channel and a second field indicating a resolution to be applied to the bitmap information, where the second field may be defined to indicate one of a plurality of predefined resolution candidates.

Description

Technical Field

[0001] The present disclosure relates to methods and apparatus for performing enhanced sub-channel selective transmission (SST) operation in a wireless local area network (WLAN) system. Background Art

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

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

[0004] Technical issues

[0005] A technical object of the present disclosure is to provide a method and apparatus for performing an enhanced subchannel selective transmission (SST) operation in a wireless local area network (WLAN) system.

[0006] A technical object of the present disclosure is to provide a method and apparatus for supporting an SST operation in a wide bandwidth that can be supported in a WLAN system.

[0007] The technical object of the present disclosure is to provide a method and apparatus for configuring / indicating a specific channel on which a station (STA) allocated to a secondary channel can transmit and receive control / management frames for SST operation in a WLAN system.

[0008] The technical objectives to be achieved by the present disclosure are not limited to the above-mentioned technical objectives, and those skilled in the art can clearly understand other technical objectives not described herein through the following description.

[0009] Technical Solution

[0010] According to one aspect of the present disclosure, a method performed by a first station (STA) in a wireless LAN system may include: receiving a frame including at least one field related to a channel for a subchannel selective transmission (SST) operation from a second STA; and performing an SST operation on the channel based on the at least one field. Here, the at least one field may include a first field and a second field, the first field including bitmap information related to activation of the channel, the second field indicating a resolution to be applied to the bitmap information, and the second field may be defined to indicate one of a plurality of predefined resolution candidates.

[0011] According to another aspect of the present disclosure, a method performed by a second station (STA) in a wireless LAN system may include: constructing a frame including at least one field related to a channel for subchannel selective transmission (SST) operation; and sending the frame including the at least one field to a first STA. Here, the at least one field may include a first field and a second field, the first field including bitmap information related to activation of the channel, the second field indicating a resolution to be applied to the bitmap information, and the second field may be defined to indicate one of a plurality of predefined resolution candidates.

[0012] Technical Effects

[0013] According to the present disclosure, a method and apparatus for performing an enhanced subchannel selective transmission (SST) operation in a wireless local area network (WLAN) system may be provided.

[0014] According to the present disclosure, a method and apparatus for supporting an SST operation in a wide bandwidth that can be supported in a WLAN system may be provided.

[0015] According to the present disclosure, a method and apparatus for configuring / indicating a specific channel on which a station (STA) allocated to a secondary channel can transmit and receive a control / management frame for an SST operation in a WLAN system may be provided.

[0016] According to the present disclosure, efficient physical layer protocol data unit (PPDU) transmission and reception can be performed in a secondary channel in a WLAN system, and throughput and efficiency can be improved based on this.

[0017] Effects achievable by the present disclosure are not limited to the above-described effects, and other effects not described herein may be clearly understood by those skilled in the relevant art through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are included as a part of the detailed description to help understanding of the present disclosure, provide embodiments of the present disclosure and describe technical features of the present disclosure together with the detailed description.

[0019] Figure 1A configuration block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0020] Figure 2 is a diagram illustrating an exemplary structure of a WLAN system to which the present disclosure can be applied.

[0021] Figure 3 It is a diagram for explaining a link establishment process to which the present disclosure can be applied.

[0022] Figure 4 This is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0023] Figure 5 It is a diagram for explaining a frame transmission operation based on CSMA / CA to which the present disclosure can be applied.

[0024] Figure 6 is a diagram for explaining an example of a frame structure used in a WLAN system to which the present disclosure can be applied.

[0025] Figure 7 is a diagram illustrating an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0026] Figure 8 is a diagram showing an example of a sub-channel selective transmission (SST) operation element format to which the present disclosure may be applied.

[0027] Fig. 9 is a diagram for explaining the operation of the first STA in the SST operation according to the present disclosure.

[0028] Fig.10 is a diagram for explaining the operation of the second STA in the SST operation according to the present disclosure. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed by the accompanying drawings is intended to describe exemplary embodiments of the present disclosure, rather than to represent the only embodiment in which the present disclosure can be implemented. The following detailed description includes specific details to provide a complete understanding of the present disclosure. However, those skilled in the relevant art know that the present disclosure can be implemented without these specific details.

[0030] In some cases, well-known structures and devices may be omitted, or may be shown in the form of a block diagram based on the core functions of each structure and device in order to prevent ambiguity of the concepts of the present disclosure.

[0031] In the present disclosure, when an element is referred to as being "connected", "combined" or "linked" to another element, it may include an indirect connection relationship between another element and a direct connection relationship. In addition, in the present disclosure, the term "comprising" or "having" specifies the presence of the mentioned features, steps, operations, components and / or elements, but does not exclude the presence or addition of one or more other features, stages, operations, components, elements and / or groups thereof.

[0032] In the present disclosure, terms such as "first", "second", etc. are only used to distinguish one element from another element and are not used to limit the elements, and unless otherwise specified, they do not limit the order or importance between elements, etc. Therefore, within the scope of the present disclosure, the first element in an embodiment may be referred to as the second element in another embodiment, and similarly, the second element in an embodiment may be referred to as the first element in another embodiment.

[0033] The terms used in this disclosure are intended to describe specific embodiments, rather than to limit the claims. As used in the description of the embodiments and the appended claims, the singular form is intended to include the plural form, unless the context clearly indicates otherwise. The term "and / or" used in this disclosure may refer to one of the related enumerated items, or mean that it refers to and includes any and all possible combinations of two or more of them. In addition, unless otherwise stated, the " / " between words in this disclosure has the same meaning as "and / or".

[0034] Examples of the present disclosure can be applied to various wireless communication systems. For example, examples of the present disclosure can be applied to wireless LAN systems. For example, examples of the present disclosure can be applied to wireless LANs based on IEEE 802.11a / g / n / ac / ax standards. In addition, examples of the present disclosure can be applied to wireless LANs based on the newly proposed IEEE 802.11be (or EHT) standard. Examples of the present disclosure can be applied to wireless LANs based on the IEEE802.11be version 2 standard corresponding to the additional enhanced technology of the IEEE 802.11be version 1 standard. In addition, examples of the present disclosure can be applied to wireless LANs based on next-generation standards after IEEE 802.11be. In addition, examples of the present disclosure can be applied to cellular wireless communication systems. For example, it can be applied to cellular wireless communication systems based on long-term evolution (LTE) technology and 5G new radio (NR) technology based on the third generation partnership project (3GPP) standard.

[0035] Hereinafter, technical features of examples to which the present disclosure can be applied will be described.

[0036] Figure 1 A block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0037] Figure 1 The first device 100 and the second device 200 illustrated in the figure may be replaced with various terms such as terminal, wireless device, wireless transmit / receive unit (WTRU), user equipment (UE), mobile station (MS), user terminal (UT), mobile subscriber station (MSS), mobile subscriber unit (MSU), subscriber station (SS), advanced mobile station (AMS), wireless terminal (WT) or simple user, etc. In addition, the first device 100 and the second device 200 include an access point (AP), a base station (BS), a fixed station, a node B, a base transceiver system (BTS), a network. It may be replaced with various terms such as an artificial intelligence (AI) system, a roadside unit (RSU), a repeater, a router, a relay and a gateway.

[0038] Figure 1 The devices 100 and 200 illustrated in the example may be referred to as stations (STAs). Figure 1 The devices 100 and 200 illustrated in the figure may be referred to by various terms such as a transmitting device, a receiving device, a transmitting STA, and a receiving STA. For example, STA110 and 200 may perform an access point (AP) role or a non-AP role. That is, in the present disclosure, STA110 and 200 may perform the functions of an AP and / or a non-AP. When STA110 and 200 perform an AP function, they may be simply referred to as an AP, and when STA110 and 200 perform a non-AP function, they may be simply referred to as a STA. In addition, in the present disclosure, an AP may also be indicated as an AP STA.

[0039] Reference Figure 1 , the first device 100 and the second device 200 can send and receive radio signals through various wireless LAN technologies (e.g., IEEE802.11 series). The first device 100 and the second device 200 may include interfaces for a media access control (MAC) layer and a physical layer (PHY) that conform to the IEEE802.11 standard.

[0040] In addition, in addition to the wireless LAN technology, the first device 100 and the second device 200 may further support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, etc.) technologies. In addition, the device of the present disclosure may be implemented in various devices such as mobile phones, vehicles, personal computers, augmented reality (AR) devices, and virtual reality (VR) devices. In addition, the STA of the present specification may support various communication services such as voice calls, video calls, data communications, autonomous driving, machine type communications (MTC), machine to machine (M2M), device to device (D2D), IoT (Internet of Things), etc.

[0041] The first device 100 may include one or more processors 102 and one or more memories 104, and may further include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memory 104 and / or the transceiver 106, and may be configured to implement the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in the present disclosure. For example, the processor 102 may send a wireless signal including the first information / signal through the transceiver 106 after generating the first information / signal by processing the information in the memory 104. In addition, the processor 102 may receive a wireless signal including the second information / signal through the transceiver 106, and then store the information obtained by the signal processing of the second information / signal in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software codes including instructions for executing all or part of the processing controlled by the processor 102 or for executing the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in the present disclosure. Here, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., IEEE 802.11 series). The transceiver 106 may be connected to the processor 102 and may send and / or receive wireless signals through one or more antennas 108. The transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used in conjunction with an RF (radio frequency) unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0042] The second device 200 may include one or more processors 202 and one or more memories 204, and may further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memory 204 and / or the transceiver 206, and may be configured to implement the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts included in the present disclosure. For example, the processor 202 may generate third information / signals by processing the information in the memory 204, and then send a wireless signal including the third information / signal through the transceiver 206. In addition, the processor 202 may receive a wireless signal including fourth information / signals through the transceiver 206, and then store information obtained by signal processing of the fourth information / signal in the memory 204. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may store software codes including instructions for executing all or part of the processing controlled by the processor 202 or for executing the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts included in the present disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., IEEE 802.11 series). The transceiver 206 may be connected to the processor 202 and may send and / or receive wireless signals through one or more antennas 208. The transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used in conjunction with an RF unit. In the present disclosure, a device may refer to a communication modem / circuit / chip.

[0043] In the following, the hardware elements of the apparatus 100, 200 will be described in more detail. Without limitation thereto, one or more protocol layers may be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 may implement one or more layers (e.g., functional layers such as PHY, MAC). One or more processors 102, 202 may generate one or more PDUs (protocol data units) and / or one or more SDUs (service data units) according to the description, function, process, suggestion, method, and / or operation flow chart disclosed in the present disclosure. One or more processors 102, 202 may generate messages, control information, data, or information according to the description, function, process, suggestion, method, and / or operation flow chart disclosed in the present disclosure. One or more processors 102, 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, processes, suggestions, and / or methods disclosed in the present disclosure to provide them to one or more transceivers 106, 206. One or more processors 102, 202 may receive a signal (e.g., a baseband signal) from one or more transceivers 106, 206 according to the descriptions, functions, processes, suggestions, methods, and / or operational flow charts included in the present disclosure and obtain a PDU, SDU, message, control information, data, or information.

[0044] One or more processors 102, 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102, 202 may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) may be included in one or more processors 102, 202. The descriptions, functions, processes, suggestions, methods, and / or operational flow charts included in the present disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, processes, functions, and the like. Firmware or software configured to execute the descriptions, functions, processes, suggestions, methods, and / or operational flow charts included in the present disclosure may be included in one or more processors 102, 202, or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions, functions, processes, suggestions, methods and / or operational flow charts included in the present disclosure may be implemented using firmware or software in the form of codes, instructions and / or instruction sets.

[0045] One or more memories 104, 204 may be connected to one or more processors 102, 202 and may store data, signals, messages, information, programs, codes, instructions, and / or commands in various forms. One or more memories 104, 204 may be configured with ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer-readable storage media, and / or combinations thereof. One or more memories 104, 204 may be located inside and / or outside one or more processors 102, 202. In addition, one or more memories 104, 204 may be connected to one or more processors 102, 202 via various technologies such as wired or wireless connections.

[0046] One or more transceivers 106, 206 may send user data, control information, wireless signals / channels, etc. mentioned in the method and / or operation flow chart of the present disclosure to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc. mentioned in the description, function, process, suggestion, method and / or operation flow chart, etc. included in the present disclosure from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and may send and receive wireless signals. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to send user data, control information or wireless signals to one or more other devices. In addition, one or more processors 102, 202 may control one or more transceivers 106, 206 to receive user data, control information or wireless signals from one or more other devices. In addition, one or more transceivers 106, 206 may be connected to one or more antennas 108, 208, and one or more transceivers 106, 206 may be configured to send and receive user data, control information, wireless signals / channels, etc. mentioned in the description, functions, processes, suggestions, methods and / or operation flow charts, etc. included in the present disclosure through one or more antennas 108, 208. In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106, 206 may convert received wireless signals / channels, etc. from RF band signals into baseband signals to process received user data, control information, wireless signals / channels, etc. by using one or more processors 102, 202. One or more transceivers 106, 206 may convert user data, control information, wireless signals / channels, etc. processed by using one or more processors 102, 202 from baseband signals into RF band signals. Thus, one or more of the transceivers 106 , 206 may include (analog) oscillators and / or filters.

[0047] For example, one of the STAs 100 and 200 may perform the expected operation of an AP, and the other of the STAs 100 and 200 may perform the expected operation of a non-AP STA. Figure 1 The transceivers 106 and 206 of the present invention may perform transmission and reception operations of signals (e.g., packets or physical layer protocol data units (PPDUs) compliant with IEEE 802.11a / b / g / n / ac / ax / be / bn). In addition, in the present disclosure, operations of various STAs generating transmission / reception signals or performing data processing or calculations on transmission / reception signals in advance may be performed by Figure 1The processors 102 and 202 are executed. For example, examples of operations of generating a transmission / reception signal or performing data processing or calculation for the transmission / reception signal in advance may include: 1) determining / obtaining / configuring / calculating / decoding / encoding bit information of fields (signal (SIG), short training field (STF), long training field (LTF), data, etc.) included in the PPDU; 2) determining / configuring / obtaining time resources or frequency resources (e.g., subcarrier resources) for fields (SIG, STF, LTF, data, etc.) included in the PPDU; 3) determining / configuring / obtaining a specific sequence (e.g., pilot sequence, STF / LTF sequence, additional sequence applied to SIG) for fields (SIG, STF, LTF, data, etc.) included in the PPDU action; 4) power control operations and / or power saving operations applied to STAs; 5) operations related to ACK signal determination / obtaining / configuring / calculating / decoding / encoding, etc. In addition, in the following example, various information used by various STAs to determine / acquire / configure / calculate / decode / encode transmission signals and reception signals (e.g., information related to fields / subfields / control fields / parameters / power, etc.) may be stored in Figure 1 in the memories 104 and 204.

[0048] Hereinafter, a downlink (DL) may mean a link for communication from an AP STA to a non-AP STA, and a DL PPDU / packet / signal may be transmitted and received through the DL. In DL communication, a transmitter may be a part of an AP STA, and a receiver may be a part of a non-AP STA. An uplink (UL) may mean a link for communication from a non-AP STA to an AP STA, and a UL PPDU / packet / signal may be transmitted and received through the UL. In UL communication, a transmitter may be a part of a non-AP STA, and a receiver may be a part of an AP STA.

[0049] Figure 2 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0050] The structure of the wireless LAN system may be composed of a plurality of components. A wireless LAN supporting STA mobility transparent to an upper layer may be provided through the interaction of the plurality of components. A basic service set (BSS) corresponds to a basic building block of a wireless LAN. Figure 2 It is exemplarily shown that two BSSs (BSS1 and BSS2) exist, and two STAs (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2) are included as members of each BSS. Figure 2The ellipse representing the BSS in the figure can also be understood as representing the coverage area in which the STAs included in the corresponding BSS maintain communication. This area can be called a basic service area (BSA). When a STA moves outside the BSA, it cannot communicate directly with other STAs in the BSA.

[0051] If you don't consider Figure 2 , the most basic BSS type in the wireless LAN is an independent BSS (IBSS), if the DS is shown in FIG. 1 . For example, an IBSS may have a minimum form containing only two STAs. For example, assuming that other components are omitted, a BSS1 containing only STA1 and STA2 or a BSS2 containing only STA3 and STA4 may correspond to representative examples of IBSSs, respectively. This configuration is possible when STAs can communicate directly without an AP. In addition, in this type of wireless LAN, it is not pre-configured but can be configured when a LAN is needed, and this may be referred to as an ad-hoc network. Since the IBSS does not include an AP, there is no centralized management entity. That is, in the IBSS, STAs are managed in a distributed manner. In the IBSS, all STAs may be composed of mobile STAs, and access to the distributed system (DS) is not allowed, thereby forming a self-contained network.

[0052] The membership of a STA in a BSS can be changed dynamically by turning the STA on or off, entering or exiting a BSS region, etc. In order to become a member of a BSS, a STA can join the BSS using a synchronization process. In order to access all services of the BSS infrastructure, a STA should associate with the BSS. This association can be established dynamically and can include the use of a distributed system service (DSS).

[0053] The direct STA-to-STA distance in a wireless LAN may be limited by PHY performance. In some cases, this distance limitation may be sufficient, but in some cases, communication between STAs at longer distances may be required. A distributed system (DS) can be configured to support extended coverage.

[0054] DS refers to the structure of BSS interconnection. Specifically, Figure 2As shown, the BSS can exist as an extended form of a network composed of multiple BSSs. DS is a logical concept and can be specified by the characteristics of the distributed system medium (DSM). At this point, the wireless medium (WM) and the DSM can be logically separated. Each logical medium is used for different purposes and is used by different components. These media are not limited to being the same, nor are they limited to being different. In this way, the flexibility of the wireless LAN structure (DS structure or other network structure) can be interpreted as multiple media being logically different. That is, the wireless LAN structure can be implemented in various ways, and the corresponding wireless LAN structure can be independently specified by the physical characteristics of each implementation.

[0055] DS can support mobile devices by providing seamless integration of multiple BSSs and providing logical services necessary to address the address leading to the destination. In addition, DS can also include a component called a portal, which is used as a bridge for connection between wireless LAN and other networks (e.g., IEEE 802.X).

[0056] The AP enables access to the DS through the WM for associated non-AP STAs and means an entity that also has STA functionality. Data movement between the BSS and the DS can be performed through the AP. For example, Figure 2 STA2 and STA3 shown in the figure have the function of STA and provide the function of allowing the associated non-AP STA (STA1 and STA4) to access the DS. In addition, since all APs basically correspond to STAs, all APs are addressable entities. The address used by the AP to communicate on the WM is not necessarily the same as the address used by the AP to communicate on the DSM. A BSS composed of an AP and one or more STAs may be referred to as an infrastructure BSS.

[0057] Data sent from one of the STAs associated with the AP to the STA address of the corresponding AP can always be received at the uncontrolled port and can be processed by the IEEE 802.1X port access entity. In addition, when the controlled port is authenticated, the transmitted data (or frame) can be delivered to the DS.

[0058] In addition to the above-mentioned structure of the DS, an extended service set (ESS) may also be configured to provide wide coverage.

[0059] ESS means a network with arbitrary size and complexity consisting of DS and BSS. ESS may correspond to a set of BSSs connected to one DS. However, ESS does not include DS. The ESS network is characterized by being regarded as an IBSS in the logical link control (LLC) layer. The STAs included in the ESS can communicate with each other, and the mobile STA can move from one BSS to another (within the same ESS) transparently for LLC. The APs included in one ESS may have the same service set identifier (SSID). SSID is distinguished from BSSID, which is an identifier of BSS.

[0060] The wireless LAN system does not assume anything about the relative physical location of the BSS, and all of the following forms are possible. The BSS may partially overlap, which is a form commonly used to provide continuous coverage. In addition, the BSS may not be physically connected, and logically, there is no limit on the distance between the BSS. In addition, the BSS may be physically located in the same location, which can be used to provide redundancy. In addition, one (or more than one) IBSS or ESS network may physically exist in the same space as one (or more than one) ESS network. When an ad hoc network operates in a location where an ESS network exists, when physically overlapping wireless networks are configured by different organizations, or when two or more different access and security policies are required in the same location, this may correspond to the form of an ESS network, etc.

[0061] Figure 3 is a diagram for explaining a link establishment process to which the present disclosure can be applied.

[0062] In order for a STA to establish a link with respect to a network and send / receive data, it first discovers the network, performs authentication, establishes association, and needs to perform authentication processing for security. The link establishment processing may also be referred to as a session initiation processing or a session establishment processing. In addition, the discovery, authentication, association, and security establishment processing of the link establishment processing may be collectively referred to as an association processing.

[0063] In step S310, the STA may perform a network discovery operation. The network discovery operation may include a scanning operation of the STA. That is, in order for the STA to access a network, it needs to find a network that it can participate in. The STA should identify compatible networks before participating in a wireless network, and the process of identifying networks present in a specific area is called scanning.

[0064] Scanning schemes include active scanning and passive scanning. Figure 3The network discovery operation including active scanning processing is exemplarily illustrated. In active scanning, the STA performing the scan sends a probe request frame to discover which APs exist around it while the channel moves and waits for a response thereto. The responder sends a probe response frame as a response to the probe request frame to the STA that has sent the probe request frame. Here, the responder may be the STA that last sent a beacon frame in the BSS of the channel being scanned. In the BSS, since the AP sends a beacon frame, the AP becomes the responder, and in the IBSS, the STAs in the IBSS rotate to send beacon frames, so the responder is not constant. For example, a STA that sends a probe request frame on channel 1 and receives a probe response frame on channel 1 may store the BSS-related information included in the received probe response frame, and may move to the next channel (e.g., channel 2), and perform scanning in the same manner (i.e., sending and receiving probe requests / responses on channel 2).

[0065] Although not in Figure 3 , but the scanning operation can be performed in a passive scanning manner. In passive scanning, the STA performing the scan waits for a beacon frame while the channel moves. The beacon frame is one of the management frames defined in IEEE 802.11, and is periodically sent to notify the existence of a wireless network and allow the STA performing the scan to find the wireless network and participate in the wireless network. In the BSS, the AP is used to periodically send beacon frames, and in the IBSS, the STAs within the IBSS rotate to send beacon frames. When the STA performing the scan receives the beacon frame, the STA stores the information of the BSS included in the beacon frame, and records the beacon frame information in each channel while moving to another channel. The STA receiving the beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform scanning in the next channel in the same manner. Comparing active scanning with passive scanning, the advantage of active scanning is that it has less delay and less power consumption than passive scanning.

[0066] After the STA discovers the network, an authentication process may be performed at step S320. In order to clearly distinguish from the security establishment operation of step S340 to be described later, this authentication process may be referred to as a first authentication process.

[0067] The authentication process includes the following process: the STA sends an authentication request frame to the AP, and in response thereto, the AP sends an authentication response frame to the STA. The authentication frame for authentication request / response corresponds to a management frame.

[0068] The authentication frame includes an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a robust security network (RSN), a limited cycle group, etc. This corresponds to some examples of information that can be included in the authentication request / response frame, and can be replaced with other information, or additional information can also be included.

[0069] The STA may send an authentication request frame to the AP. The AP may determine whether to allow authentication of the corresponding STA based on the information included in the received authentication request frame. The AP may provide the result of the authentication process to the STA via an authentication response frame.

[0070] After the STA is successfully authenticated, an association process may be performed at step S330. The association process includes the following processes: the STA sends an association request frame to the AP, and in response, the AP sends an association response frame to the STA.

[0071] For example, the association request frame may include information related to various capabilities, a beacon listening interval, a service set identifier (SSID), supported rates, supported channels, RSN, a mobile domain, supported operation categories, a traffic indication map broadcast request (TIM broadcast request), interworking service capabilities, etc. For example, the association response frame may include information related to various capabilities, a status code, an association ID (AID), supported rates, an enhanced distributed channel access (EDCA) parameter set, a received channel power indicator (RCPI), a received signal-to-noise ratio indicator (RSNI), a mobile domain, a timeout interval (e.g., an association recovery time), an overlapping BSS scan parameter, a TIM broadcast response, a quality of service (QoS) map, etc. This corresponds to some examples of information that may be included in an association request / response frame, and may be replaced with other information, or may also include additional information.

[0072] After the STA successfully associates with the network, a security establishment process may be performed at step S340. The security establishment process at step S340 may be referred to as an authentication process through a robust security network association (RSNA) request / response, the authentication process at step S320 may be referred to as a first authentication process, and the security establishment process at step S340 may also be referred to simply as an authentication process.

[0073] The security establishment process of step S340 may include, for example, a process of establishing a private key through an Extensible Authentication Protocol over LAN (EAPOL) frame using a four-way handshake. In addition, the security establishment process may be performed according to a security scheme not defined in the IEEE 802.11 standard.

[0074] Figure 4 It is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0075] In a wireless LAN system, the basic access mechanism of the medium access control (MAC) is a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism. The CSMA / CA mechanism is also known as the distributed coordination function (DCF) of the IEEE 802.11 MAC, and basically adopts a "listen before talk" access mechanism. According to this type of access mechanism, before starting to send, the AP and / or STA may perform a clear channel assessment (CCA) of sensing the radio channel or medium during a predetermined time interval (e.g., DCF interframe space (DIFS)). As a result of the sensing, if it is determined that the medium is in an idle state, frame transmission is started through the corresponding medium. On the other hand, if it is detected that the medium is occupied or busy, the corresponding AP and / or STA does not start its own transmission, and a delay period (e.g., a random backoff period) for medium access may be set and frame transmission may be attempted after waiting. By applying a random backoff period, since multiple STAs are expected to attempt frame transmission after waiting for different time periods, conflicts can be minimized.

[0076] In addition, the IEEE 802.11 MAC protocol provides a hybrid coordination function (HCF). HCF is based on DCF and point coordination function (PCF). PCF is a synchronous access method based on polling, and refers to a method in which all receiving APs and / or STAs periodically poll to receive data frames. In addition, HCF has enhanced distributed channel access (EDCA) and HCF controlled channel access (HCCA). EDCA is a contention-based access method that provides data frames to multiple users in a direction, and HCCA uses a non-contention-based channel access method that utilizes a polling mechanism. In addition, HCF includes a medium access mechanism for improving the QoS (quality of service) of a wireless LAN, and QoS data can be sent during a contention period (CP) and a contention-free period (CFP).

[0077] Reference Figure 4, the operation based on the random backoff period will be described. When the occupied / busy medium becomes idle, multiple STAs may attempt to send data (or frames). As a method of minimizing conflicts, each of the STAs may select a random backoff count respectively and attempt to send after waiting for the corresponding time slot time. The random backoff count has a pseudo-random integer value and may be determined as one of the values ​​ranging from 0 to CW. Here, CW is a contention window parameter value. The CW parameter is assigned CWmin as an initial value, but may take a value twice as large in the event of a transmission failure (e.g., when an ACK for a transmitted frame is not received). When the CW parameter value reaches CWmax, data transmission may be attempted while maintaining the CWmax value until data transmission is successful, and when data transmission is successful, the CWmin value is reset. The values ​​of CW, CWmin, and CWmax are preferably set to 2n-1 (n=0, 1, 2, ...).

[0078] When the random backoff process starts, the STA continuously monitors the medium in the backoff slot countdown according to the determined backoff count value. When the medium is monitored for occupancy, it stops the countdown and waits, and restarts the remaining part of the countdown when the medium becomes idle.

[0079] exist Figure 4 In the example of , when the packet to be sent arrives at the MAC of STA 3, STA3 can send the frame immediately after confirming that the medium has been idle for up to DIFS. The remaining STAs monitor and wait for the medium to be occupied / busy. At the same time, the data to be sent can also occur in each of STA1, STA2 and STA5, and when the medium is monitored as idle, each STA waits for up to DIFS, and then the countdown of the backoff slot can be performed according to the random backoff count value selected by each STA. Assume that STA2 selects the minimum backoff count value and STA1 selects the maximum backoff count value. That is, the example illustrates the case where the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1 when STA2 completes the backoff count and starts frame transmission. STA1 and STA5 temporarily stop the countdown and wait when STA2 occupies the medium. When STA2's occupation ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and restart the stopped backoff count. That is, frame transmission can start after counting down the remaining backoff slot for the remaining backoff time. Since the remaining backoff time of STA5 is shorter than that of STA1, STA5 starts frame transmission. The data to be transmitted may also occur in STA4 while STA2 occupies the medium. From the perspective of STA4, when the medium becomes idle, STA4 may wait for DIFS, and then may perform a countdown according to a random backoff count value selected by STA4, and start transmitting frames. Figure 4The example shows a case where the remaining backoff time of STA5 accidentally collides with the random backoff count value of STA4. In this case, a collision may occur between STA4 and STA5. When a collision occurs, neither STA4 nor STA5 receives an ACK, so data transmission fails. In this case, STA4 and STA5 can double the CW value, select a random backoff count value, and perform a countdown. While the medium is occupied due to the transmission of STA4 and STA5, STA1 waits, and when the medium becomes idle, STA1 waits DIFS, and then starts frame transmission after the remaining backoff time has passed.

[0080] As in Figure 4 In the example of , a data frame is a frame for sending data forwarded to a higher layer, and may be sent after a backoff performed after DIFS has passed since the medium became idle. In addition, a management frame is a frame for exchanging management information that is not forwarded to a higher layer, and is sent after a backoff is performed after an IFS such as DIFS or a point coordination function IFS (PIFS). As subtype frames of the management frame, there are beacons, association requests / responses, reassociation requests / responses, probe requests / responses, authentication requests / responses, and the like. A control frame is a frame for controlling access to a medium. As subtype frames of the control frame, there are request to send (RTS), clear to send (CTS), acknowledgement (ACK), power save poll (PS-Poll), block ACK (BlockAck), block ACK request (BlockACKReq), empty data packet announcement (NDP announcement), and trigger, and the like. If the control frame is not a response frame of the previous frame, it is sent after a backoff is performed after DIFS has passed, and if it is a response frame of the previous frame, it is sent without performing a backoff after a short IFS (SIFS). The type and subtype of a frame may be identified by the type field and subtype field in the frame control (FC) field.

[0081] Quality of Service (QoS) STA can perform a backoff performed after arbitration IFS (AIFS) (i.e., AIFS (where i is a value determined by AC)) for the access category (AC) to which the frame belongs, and then can send the frame. Here, the frame that can use AIFS may be a data frame, a management frame, or a control frame instead of a response frame.

[0082] Figure 5 is a diagram for explaining a frame transmission operation based on CSMA / CA to which the present disclosure can be applied.

[0083] As described above, in addition to the physical carrier sensing in which the STA directly senses the medium, the CSMA / CA mechanism also includes virtual carrier sensing. Virtual carrier sensing is intended to compensate for problems such as hidden node problems that may occur in medium access. For virtual carrier sensing, the MAC of the STA can use a network allocation vector (NAV). NAV is a value that indicates to other STAs the remaining time until the medium is available for use by the STA that is currently using or has the right to use the medium. Therefore, the value set to NAV corresponds to the period during which the STA sending the frame plans to use the medium, and during the corresponding period, the STA receiving the NAV value is prohibited from accessing the medium. For example, the NAV can be configured based on the value of the "Duration" field of the MAC header of the frame.

[0084] exist Figure 5 In the example of FIG. 1 , it is assumed that STA1 intends to send data to STA2, and STA3 is in a position to be able to eavesdrop on some or all frames sent and received between STA1 and STA2.

[0085] In order to reduce the possibility of transmission conflicts among multiple STAs in the CSMA / CA-based frame transmission operation, a mechanism using RTS / CTS frames can be applied. Figure 5 In the example of , when STA1's transmission is being performed, as a result of STA3's carrier sensing, it can be determined that the medium is in an idle state. That is, STA1 may correspond to a hidden node with respect to STA3. Alternatively, in Figure 5 In the example of , it can be determined that the carrier sensing result medium of STA3 is in an idle state while the transmission of STA2 is being performed. That is, STA2 may correspond to a hidden node with respect to STA3. By exchanging RTS / CTS frames before performing data transmission and reception between STA1 and STA2, STAs outside the transmission range of one of STA1 or STA2 or STAs outside the carrier sensing range of the transmission from STA1 or STA3 may not attempt to occupy the channel during data transmission and reception between STA1 and STA2.

[0086] Specifically, STA1 can determine whether the channel is being used by carrier sensing. In terms of physical carrier sensing, STA1 can determine the channel occupancy idle state based on the energy level or signal correlation detected in the channel. In addition, in terms of virtual carrier sensing, STA1 can use the network allocation vector (NAV) timer to determine the channel occupancy state.

[0087] When the channel is in an idle state during DIFS, STA1 may send an RTS frame to STA2 after performing backoff. When STA2 receives the RTS frame, STA2 may send a CTS frame to STA1 as a response to the RTS frame after SIFS.

[0088] If STA3 cannot eavesdrop on the CTS frame from STA2 but can eavesdrop on the RTS frame from STA1, STA3 can set the NAV timer for the frame transmission period (e.g., SIFS+CTS frame+SIFS+data frame+SIFS+ACK frame) that is continuously transmitted thereafter using the duration information included in the RTS frame. Alternatively, if STA3 can eavesdrop on the CTS frame from STA2, STA3 can set the NAV timer for the frame transmission period (e.g., SIFS+data frame+SIFS+ACK frame) that is continuously transmitted thereafter using the duration information included in the CTS frame even though STA3 cannot eavesdrop on the RTS frame from STA1. That is, if STA3 can eavesdrop on one or more of the RTS frame or the CTS frame from one or more of STA1 or STA2, STA3 can set the NAV accordingly. When STA3 receives a new frame before the NAV timer expires, STA3 can update the NAV timer using the duration information included in the new frame. STA3 does not attempt channel access until the NAV timer expires.

[0089] When STA1 receives a CTS frame from STA2, STA1 may send a data frame to STA2 after SIFS, starting from the time point when reception of the CTS frame is completed. When STA2 successfully receives the data frame, STA2 may send an ACK frame to STA1 after SIFS as a response to the data frame. When the NAV timer expires, STA3 may determine whether the channel is being used by carrier sensing. When STA3 determines that the channel is not being used by other terminals during the DIFS period after the NAV timer expires, STA3 may attempt channel access after the contention window (CW) according to the random backoff has passed.

[0090] Figure 6 is a diagram for explaining an example of a frame structure used in a WLAN system to which the present disclosure can be applied.

[0091] With the help of instructions or primitives (meaning a set of instructions or parameters) from the MAC layer, the PHY layer can prepare a MAC PDU (MPDU) to be transmitted. For example, when a command requesting the PHY layer to start transmitting is received from the MAC layer, the PHY layer switches to a transmission mode, and configures information (e.g., data) provided from the MAC layer in the form of a frame and transmits it. In addition, when the PHY layer detects a valid preamble of a received frame, the PHY layer monitors the header of the preamble and transmits a command notifying the start of reception of the PHY layer to the MAC layer.

[0092] In this manner, information transmission / reception in the wireless LAN system is performed in the form of a frame, and for this purpose, a PHY layer protocol data unit (PPDU) format is defined.

[0093] The basic PPDU may include a short training field (STF), a long training field (LTF), a signal (SIG) field, and a data (Data) field. The most basic PPDU format (e.g., Figure 7 The non-HT (high throughput) shown in the figure may consist of only the legacy-STF (L-STF), the legacy-LTF (L-LTF), the legacy-SIG (L-SIG) field and the data field. In addition, depending on the type of PPDU format (e.g., HT mixed format PPDU, HT greenfield format PPDU, VHT (very high throughput) PPDU, etc.), additional (or different types of) RL-SIG, U-SIG, non-legacy SIG field, non-legacy STF, non-legacy LTF (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)) and the like may be included between the L-SIG field and the data field.

[0094] STF is a signal used for signal detection, automatic gain control (AGC), diversity selection, precise time synchronization, etc., and LTF is a signal used for channel estimation and frequency error estimation. STF and LTF can be called signals for synchronization and channel estimation of the OFDM physical layer.

[0095] The SIG field may include various information related to the transmission and reception of the PPDU. For example, the L-SIG field consists of 24 bits, and the L-SIG field may include a 4-bit rate field, a 1-bit reserved bit, a 12-bit length field, a 1-bit parity field, and a 6-bit tail field. The RATE field may include information about the modulation and coding rate of the data. For example, the 12-bit length field may include information about the length or duration of the PPDU. For example, the value of the 12-bit length field may be determined based on the type of the PPDU. For example, for non-HT, HT, VHT, or EHT PPDUs, the value of the length field may be determined as a multiple of 3. For example, for HE PPDUs, the value of the length field may be determined as a multiple of 3+1 or a multiple of 3+2.

[0096] The data field may include a service (SERVICE) field, a physical layer service data unit (PSDU) and a PPDU tail bit, and may also include padding bits if necessary. Some bits of the service field may be used for synchronization of the descrambler at the receiving end. The PSDU corresponds to the MAC PDU defined in the MAC layer and may include data generated / used in the upper layer. The PPDU tail bit may be used to return the encoder to the 0 state. The padding bit may be used to adjust the length of the data field in predetermined units.

[0097] MAC PDU is defined according to various MAC frame formats, and a basic MAC frame consists of a MAC header, a frame body, and a frame check sequence (FCS). A MAC frame may consist of a MAC PDU and be transmitted / received through a PSDU of a data portion of a PPDU format.

[0098] The MAC header includes a frame control field, a duration / ID field, an address field, etc. The frame control field may include control information required for frame transmission / reception. The duration / ID field may be set to the time for transmitting the corresponding frame, etc. For details of the sequence control, QoS control, and HT control subfields of the MAC header, refer to the IEEE 802.11 standard document.

[0099] The null data PPDU (NDP) format refers to a PPDU format that does not include a data field. In other words, NDP refers to a frame format that includes a PPDU preamble (i.e., L-STF, L-LTF, L-SIG fields and additional non-legacy SIG, non-legacy STF, non-legacy LTF (if present)) of a general PPDU format and does not include the remaining part (i.e., the data field).

[0100] Figure 7 is a diagram illustrating an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0101] In standards such as IEEE 802.11a / g / n / ac / ax, various types of PPDUs have been used. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and data fields. The basic PPDU format may also be referred to as a non-HT PPDU format (such as Figure 7 (as shown in (a)).

[0102] Compared to the basic PPDU format, the HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT fields. Figure 7The HT PPDU format shown in (b) may be referred to as an HT mixed format. In addition, an HT greenfield format PPDU may be defined, and this corresponds to a format consisting of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs, and a data field, excluding L-STF, L-LTF, and L-SIG (not shown).

[0103] Compared to the basic PPDU format, an example of the VHT PPDU format (IEEE 802.11ac) additionally includes VHTSIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields (eg, Figure 7 (as shown in (c)).

[0104] Compared to the basic PPDU format, an example of the HE PPDU format (IEEE 802.11ax) additionally includes a repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF, a packet extension (PE) field (such as Figure 7 (d) of the HE PPDU format). Some fields may be excluded or their lengths may vary according to the detailed example of the HE PPDU format. For example, the HE-SIG-B field is included in the HE PPDU format for multi-user (MU), and the HE-SIG-B is not included in the HE PPDU format for single user (SU). In addition, the HE trigger-based (TB) PPDU format does not include the HE-SIG-B, and the length of the HE-STF field may vary to 8μs. The extended range (HE ER) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may vary to 16μs. For example, the RL-SIG may be configured to be the same as the L-SIG. Based on the presence of the RL-SIG, the receiving STA may know that the received PPDU is a HE PPDU or an EHT PPDU, which will be described later.

[0105] The EHT PPDU format may include Figure 7 (e) EHT MU (multi-user) and Figure 7 The EHT TB (trigger-based) PPDU in (f) of FIG. The EHT PPDU format is similar to the HE PPDU format in that it includes the RL-SIG following the L-SIG, but may include the U (Universal)-SIG, the EHT-SIG, the EHT-STF, and the EHT-LTF following the RL-SIG.

[0106] Figure 7The EHT MU PPDU in (e) corresponds to a PPDU carrying one or more data (or PSDU) for one or more users. That is, the EHT MU PPDU can be used for both SU transmission and MU transmission. For example, the EHT MU PPDU can correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0107] Compared with EHT MU PPDU, Figure 7 The EHT TB PPDU in (f) omits the EHT-SIG. A STA that receives a trigger for UL MU transmission (eg, a trigger frame or a triggered response schedule (TRS)) may perform UL transmission based on the EHT TB PPDU format.

[0108] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal Signal), EHT-SIG fields may be coded and modulated so that even legacy STAs may attempt to demodulate and decode, and may be mapped based on a determined subcarrier frequency interval (e.g., 312.5kHz). These may be referred to as pre-EHT modulation fields. Next, the EHT-STF, EHT-LTF, data, PE fields may be coded and modulated so that they may be demodulated and decoded by a STA that successfully decodes a non-legacy SIG (e.g., U-SIG and / or EHT-SIG) and obtains the information included in the field, and may be mapped based on a determined subcarrier frequency interval (e.g., 78.125kHz). These may be referred to as EHT modulation fields.

[0109] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields may be referred to as pre-HE modulation fields, and the HE-STF, HE-LTF, data, and PE fields may be referred to as HE modulation fields. In addition, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields may be referred to as non-VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and data fields may be referred to as VHT modulation fields.

[0110] Included in Figure 7The U-SIG in the EHT PPDU format may be configured based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) used for the U-SIG may have a duration of 4 μs, and the U-SIG may have a total duration of 8 μs. Each symbol of the U-SIG may be used to send 26 bits of information. For example, each symbol of the U-SIG may be sent and received based on 52 data tones and 4 pilot tones.

[0111] The U-SIG may be constructed in units of 20 MHz. For example, if an 80 MHz PPDU is constructed, the U-SIG may be duplicated. That is, the same 4 U-SIGs may be included in the 80 MHz PPDU. A PPDU with a bandwidth exceeding 80 MHz may include a different U-SIG.

[0112] For example, A uncoded bits may be sent via U-SIG, the first symbol of U-SIG (e.g., U-SIG-1 symbol) may send the first X bits of information out of a total of A bits of information, and the second symbol of U-SIG (e.g., U-SIG-2 symbol) may send the remaining Y bits of information out of a total of A bits of information. The A bits of information (e.g., 52 uncoded bits) may include a CRC field (e.g., a 4-bit long field) and a tail field (e.g., a 6-bit long field). For example, the tail field may be used to terminate the trellis structure of the convolutional decoder and may be set to 0.

[0113] The bit information sent through U-SIG can be divided into version-independent bits and version-dependent bits. For example, U-SIG can be included in Figure 7 In a new PPDU format not shown in the EHT PPDU format (e.g., UHR PPDU format), and may be included in the format of the U-SIG field included in the EHT PPDU format and the format of the U-SIG field included in the UHR PPDU format, the version-independent bits may be the same, and some or all of the version-related bits may be different.

[0114] For example, the size of the version-independent bit of the U-SIG may be fixed or variable. The version-independent bit may be assigned only to the U-SIG-1 symbol, or to both the U-SIG-1 symbol and the U-SIG-2 symbol. The version-independent bit and the version-dependent bit may be referred to by various names, such as a first control bit and a second control bit.

[0115] For example, the version-independent bits of the U-SIG may include a 3-bit physical layer version identifier (PHY version identifier), and the information may indicate the PHY version (e.g., EHT, UHR, etc.) of the transmitted / received PPDU. The version-independent bits of the U-SIG may include a 1-bit UL / DL flag field. The first value of the 1-bit UL / DL flag field is related to UL communication, and the second value of the UL / DL flag field is related to DL communication. The version-independent bits of the U-SIG may include information about the length of a transmit opportunity (TXOP) and information about a BSS color ID.

[0116] For example, the version-related bits of the U-SIG may include information directly or indirectly indicating the type of the PPDU (eg, SUPPDU, MU PPDU, TB PPDU, etc.).

[0117] Information required for PPDU transmission and reception may be included in the U-SIG. For example, the U-SIG may also include information about bandwidth, information about an MCS technology applied to a non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.), information indicating whether a DCM (dual carrier modulation) technology (e.g., a technology for achieving an effect similar to frequency diversity by reusing the same signal on two subcarriers) is applied to the non-legacy SIG, information about the number of symbols used for the non-legacy SIG, and information about whether the non-legacy SIG is generated across the entire frequency band.

[0118] Some of the information required for PPDU transmission and reception may be included in the U-SIG and / or the non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.). For example, information about the type of non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information about the length of the non-legacy LTF and the CP (cyclic prefix) length, information about the GI (guard interval) applicable to the non-legacy LTF, information about preamble puncturing applicable to the PPDU, information about resource unit (RU) allocation, etc. may be included only in the U-SIG, only in the non-legacy SIG, or may be indicated by a combination of information included in the U-SIG and information included in the non-legacy SIG.

[0119] Preamble puncturing may indicate the transmission of a PPDU in which there is no signal in one or more frequency units in the bandwidth of the PPDU. For example, the size of the frequency unit (or the resolution of the preamble puncturing) may be defined as 20 MHz, 40 MHz, etc. For example, preamble puncturing may be applied to a PPDU bandwidth of a predetermined size or greater.

[0120] exist Figure 7In the example of , non-legacy SIGs such as HE-SIG-B and EHT-SIG may include control information for receiving STAs. The non-legacy SIG may be transmitted on at least one symbol, and one symbol may have a length of 4 μs. Information about the number of symbols used for the EHT-SIG may be included in a previous SIG (eg, HE-SIG-A, U-SIG, etc.).

[0121] Non-legacy SIGs such as HE-SIG-B and EHT-SIG may include a common field and a user-specific field. The common field and the user-specific field may be encoded separately.

[0122] In some cases, the common field may be omitted. For example, in a compressed mode that does not apply OFDMA (Orthogonal Frequency Division Multiple Access), the common field may be omitted, and multiple STAs may receive the PPDU (e.g., the data field of the PPDU) through the same frequency band. In a non-compressed mode that applies OFDMA, multiple users may receive the PPDU (e.g., the data field of the PPDU) through different frequency bands.

[0123] The number of user-specific fields may be determined based on the number of users. A user block field may include up to two user fields. Each user field may be associated with a MU-MIMO allocation or may be associated with a non-MU-MIMO allocation.

[0124] The common field may include CRC bits and tail bits, and the length of the CRC bits may be determined to be 4 bits, while the length of the tail bits may be determined to be 6 bits and set to 000000. The common field may include RU allocation information. The RU allocation information may include information about the locations of RUs to which multiple users (ie, multiple receiving STAs) are assigned.

[0125] RU can include multiple subcarriers (or tones). RU can be used when sending signals to multiple STAs based on OFDMA technology. In addition, RU can be defined even when sending signals to one STA. Resources can be allocated to non-traditional STF, non-traditional LTF and data fields in units of RU.

[0126] The RU of applicable size may be defined according to the PPDU bandwidth. The RU may be defined identically or differently for the applied PPDU format (e.g., HEPPDU, EHT PPDU, UHR PPDU, etc.). For example, in the case of an 80MHz PPDU, the RU layout of the HEPPDU and EHT PPDU may be different. The applicable RU size, the number of RUs and RU positions, the DC (direct current) subcarrier positions and numbers, the empty subcarrier positions and numbers, the guard subcarrier positions and numbers, etc. for each PPDU bandwidth may be referred to as a tone plan. For example, a tone plan for high bandwidth may be defined in the form of multiple iterations of a low bandwidth tone plan.

[0127] RUs of various sizes may be defined as 26-tone RUs, 52-tone RUs, 106-tone RUs, 242-tone RUs, 484-tone RUs, 996-tone RUs, 2×996-tone RUs, 3×996-tone RUs, etc. MRUs (multi-RUs) are different from multiple individual RUs and correspond to a group of subcarriers consisting of multiple RUs. For example, one MRU may be defined as 52+26 tones, 106+26 tones, 484+242 tones, 996+484 tones, 996+484+242 tones, 2×996+484 tones, 3×996 tones, or 3×996+484 tones. In addition, the multiple RUs constituting one MRU may or may not be continuous in the frequency domain.

[0128] The specific size of the RU may be reduced or expanded. Therefore, the specific size of each RU in the present disclosure (i.e., the number of corresponding tones) is not restrictive but illustrative. In addition, in the present disclosure, within a predetermined bandwidth (e.g., 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz ...), the number of RUs may vary according to the RU size.

[0129] Figure 7 The names of each field in the PPDU format are exemplary, and the scope of the present disclosure is not limited by these names. In addition, the examples of the present disclosure can be applied to Figure 7 The PPDU format shown in Figure 7 A new PPDU format that excludes some fields and / or adds some fields.

[0130] Subchannel Selective Transmission Operation

[0131] SST may include dynamically changing the primary channel within the total bandwidth. For example, SST operation may include operating under the assumption that only a portion of the total bandwidth is the entire bandwidth.

[0132] A STA and an AP having the capability to support SST operation may set up SST operation by negotiating a target wake-up time (TWT) that triggers the activation.

[0133] Here, the TWT request may include a TWT channel field with at most one bit set to 1, which may indicate a secondary channel, and the request includes an RU allocation addressed to a 20 MHz operating STA for the secondary channel.

[0134] The TWT request may include a TWT channel field with all four LSBs or all four MSBs set to 1, which may indicate whether a primary 80 MHz channel or a secondary 80 MHz channel is requested including an RU allocation addressed to an 80 MHz operating STA.

[0135] The TWT response may include a TWT channel field with at most one bit set to 1, which may indicate a secondary channel that will contain RU allocations addressed to 20 MHz operating STAs. The TWT response may include a TWT channel field with all four LSBs or all four MSBs set to 1, which may indicate whether the primary 80 MHz channel or the secondary 80 MHz channel may contain RU allocations addressed to 80 MHz operating STAs.

[0136] STAs and APs that have successfully established SST operations can operate according to the following rules.

[0137] If the AP changes its operating channel or channel width and the secondary channel that triggered the enabled TWT does not exist within the new operating channel or channel width, the AP and STA implicitly terminate the triggered enabled TWT.

[0138] The AP may follow a separate TWT protocol to exchange frames with STAs during a triggered-enabled TWT service period (SP). Here, the AP may ensure that the individually addressed RUs allocated in the DL MU PPUD and trigger frames reside within the subchannel indicated in the TWT channel field of the TWT response and follow the RU constraint rules. The same subchannel may be used for the same STA and all triggered-enabled TWT SPs that overlap in time.

[0139] The STA operating on the secondary channel may not perform an operation mode indication (OMI) operation or an operation mode notification (OMN) operation for changing the operation bandwidth.

[0140] The STA may follow a separate TWT protocol to exchange frames with the AP during a triggered enabled TWT SP. Here, the STA may be available on the subchannel indicated in the TWT channel field of the TWT response at the TWT start time. The STA may not access the medium on the subchannel using the DCF or EDCA function (EDCAF). The STA may not respond to a trigger frame addressed to it unless it detects a frame for which the NAV can be set by performing a CCA. If the STA receives a PPDU on the subchannel, the STA may update the NAV.

[0141] The STA may include a channel switch timing element in the (re)association request frame sent to the AP to indicate the time required for the STA to switch between different subchannels. The received channel switch time may inform the AP of the time period during which the STA may not be able to receive frames before the TWT start time and after the enabled TWT SP is triggered.

[0142] Figure 8 is a diagram showing an example of a sub-channel selective transmission (SST) operation element format to which the present disclosure may be applied.

[0143] The SST operation element format in the existing wireless LAN system may include an 8-bit element ID field, an 8-bit length field, an 8-bit SST enabled channel bitmap field, a 3-bit primary channel offset field, a 1-bit SST channel unit field, and 4-bit reserved bits.

[0144] The element ID field is used to identify the element of the corresponding format, and the length field can indicate the number of eight-bit bytes of the element except the element ID field and the length field.

[0145] The SST Activated Channel Bitmap field may include a bitmap indicating channels activated for SST operation. Each bit of the bitmap corresponds to a channel with the same width as the value of the SST Channel Unit field, and the least significant bit (LSB) may correspond to the lowest numbered subchannel in the SST Activated Channel Bitmap field.

[0146] The channel number of each channel in the SST Activated Channel Bitmap field may be equal to PCN minus (-)OPC plus (+)POS, where PCN is the value of the Primary Channel Number subfield of the most recently transmitted S1G Operation element. OPC is the offset of the primary channel relative to the lowest numbered subchannel in the bitmap, as specified by the value of the Primary Channel Offset field. POS is the position of the channel in the bitmap.

[0147] Setting a bit position in the bitmap to 1 may indicate that the subchannel is enabled for SST operation, but transmission from the SST STA is permitted on the subchannel according to the rules defined in the specification.One or more bits in the bitmap may be equal to 1.

[0148] The Primary Channel Offset field may indicate the relative position of the primary channel relative to the lowest numbered channel in the SST Active Channel Bitmap field. For example, setting the Primary Channel Offset field to 2 may indicate that the primary channel is the third subchannel in the SST Active Channel Bitmap.

[0149] The SST Channel Unit field may indicate the channel width unit of each SST channel. Setting this field to 1 may indicate that the channel width unit is 1 MHz, and setting this field to 2 may indicate that the channel width unit is 2 MHz.

[0150] Enhanced SST Operation

[0151] Hereinafter, the present disclosure proposes a method for defining an enhanced SST operation and related SST operation elements to improve throughput and efficiency in a next generation wireless LAN system.

[0152] In the case of the SST operation and the SST operation element in the above-mentioned existing wireless LAN system, there is no specific channel for use by the primary channel, through which the STA assigned to the secondary channel can send and receive control frames and / or management frames. Therefore, there is no configuration / indication method for the specific channel.

[0153] Here, the specific channel may mean a channel that functions similarly to the main 20 MHz channel (ie, P20) within the secondary channel.

[0154] In the following disclosure, for the sake of clarity of explanation, a specific channel is referred to as a primary-like channel. In this regard, the method proposed in the present disclosure is not limited by the name, and it is not excluded that a specific channel can be applied by replacing it with another name. In addition, the primary-like channel in the present disclosure is described under the assumption that it is set in units of 20 MHz, but it is not excluded that it can be set in units of other channel widths.

[0155] In addition, for the SST operation and SST operation elements in the above-mentioned existing wireless LAN system, within the 320MHz bandwidth, channels for SST operation can be allocated only within the primary 160MHz channel (i.e., P160), and allocation within the secondary 160MHz channel (i.e., S160) is not possible. In addition, channel allocation for SST operation in wide bandwidths (e.g., 480MHz bandwidth, 640MHz bandwidth, etc.) that can be supported in the next-generation wireless LAN system is not considered.

[0156] In view of these points, the present disclosure proposes, through various examples, a method for allocating channels for SST operations in consideration of a wide bandwidth, and a method for configuring a quasi-master channel to effectively manage SST operations.

[0157] Fig. 9 is a diagram for explaining the operation of the first STA in the SST operation according to the present disclosure.

[0158] In step S910 , the first STA may receive a frame including at least one field related to a channel for an SST operation from a second STA.

[0159] Here, at least one field may include a first field (e.g., an SST activation channel bitmap field) and a second field (e.g., a resolution field), the first field including bitmap information related to the activation of the corresponding channel, and the second field indicating the resolution to be applied to the corresponding bitmap information.

[0160] At this time, the second field may be defined to indicate one of a plurality of predefined resolution candidates. For example, the plurality of resolution candidates may be defined to include at least two of 20 MHz resolution, 40 MHz resolution, or 80 MHz resolution.

[0161] For example, if the maximum bandwidth associated with SST operation corresponds to a 320 MHz bandwidth, the second field may consist of 1 bit. In this case, a first value (e.g., a value of 0) based on the 1 bit may be defined to indicate a 20 MHz resolution, and a second value (e.g., a value of 1) may be defined to indicate a 40 MHz resolution.

[0162] For example, if the maximum bandwidth associated with the SST operation is a 480 MHz bandwidth or a 640 MHz bandwidth, the second field may consist of 2 bits. In this case, a first value (e.g., a value 0 corresponding to "00") of the 2 bits may indicate a 20 MHz resolution, a second value (e.g., a value 1 corresponding to "01") may indicate a 40 MHz resolution, a third value (e.g., a value 2 corresponding to "10") may indicate an 80 MHz resolution, and a fourth value (e.g., a value 3 corresponding to "11") may be defined as a reserved value.

[0163] In this regard, the number of bits in the first field may be variably set based on the size of the maximum bandwidth associated with the above-described SST operation.

[0164] In step S920, the first STA may perform an SST operation on the corresponding channel based on at least one field included in the frame.

[0165] For example, the step of performing the SST operation may include the step of performing transmission and reception of a control frame or a management frame on a specific 20 MHz channel within the secondary channel to which the first STA is allocated.

[0166] That is, the specific 20 MHz channel may correspond to a primary 20 MHz channel, ie, a quasi-primary channel that performs a function similar to P20. The specific 20 MHz channel may be configured within a secondary channel having a channel unit greater than or equal to 80 MHz.

[0167] In this regard, the specific 20MHz channel may correspond to a 20MHz channel within the secondary channel located at a point corresponding to the position of P20 of the BSS to which the first STA belongs. That is, the specific 20MHz channel may be implicitly indicated. Here, the position of P20, the position of the primary channel including P20, and / or the position of the secondary channel may be identified by a beacon received by the first STA.

[0168] If the 20 MHz channel is punctured, the above-mentioned specific 20 MHz channel may correspond to a secondary 20 MHz channel of the BSS to which the first STA belongs, that is, a 20 MHz channel within the secondary channel located at a point corresponding to the position of S20 .

[0169] Furthermore, when the 20 MHz channel within the secondary channel is punctured, the specific 20 MHz channel may be configured as one of two 20 MHz channels corresponding to the position of the secondary 40 MHz channel (ie, S40 ) according to a predefined rule.

[0170] For example, the two 20 MHz channels may include a) a first 20 MHz channel corresponding to the position of the primary 20 MHz channel within the primary 40 MHz channel, and b) a second 20 MHz channel corresponding to the position of the secondary 20 MHz channel within the primary 40 MHz channel.

[0171] Furthermore, when two 20 MHz channels are punctured, the above-mentioned specific 20 MHz channel may be configured as one of four 20 MHz channels corresponding to the position of the secondary 80 MHz channel (ie, S80) according to a predefined rule.

[0172] For example, the four 20MHz channels may include: a) a first 20MHz channel corresponding to the position of the main 20MHz channel within the main 80MHz channel; b) a second 20MHz channel corresponding to the position of the auxiliary 20MHz channel within the main 80MHz channel; c) a third 20MHz channel corresponding to the position of the main 20MHz channel within the main 40MHz channel among the two 20MHz channels corresponding to the position of the auxiliary 40MHz channel within the main 80MHz channel; and d) a fourth 20MHz channel corresponding to the position of the auxiliary 20MHz channel within the main 40MHz channel among the two 20MHz channels corresponding to the position of the auxiliary 40MHz channel within the main 80MHz channel.

[0173] Furthermore, based on the puncturing of the four 20 MHz channels, the specific 20 MHz channel may be configured as one of the eight 20 MHz channels corresponding to the position of the secondary 160 MHz (ie, S160) channel according to a predefined rule.

[0174] For example, the eight 20MHz channels may include: a) a first 20MHz channel corresponding to the position of the main 20MHz channel within the main 160MHz channel; b) a second 20MHz channel corresponding to the position of the auxiliary 20MHz channel within the main 160MHz channel; c) a third 20MHz channel corresponding to the position of the main 20MHz channel within the main 40MHz channel among the two 20MHz channels corresponding to the position of the auxiliary 40MHz channel within the main 160MHz channel; d) a fourth 20MHz channel corresponding to the position of the auxiliary 20MHz channel within the main 40MHz channel among the two 20MHz channels corresponding to the position of the auxiliary 40MHz channel within the main 160MHz channel; e) a fourth 20MHz channel corresponding to the position of the main 20MHz channel within the main 80MHz channel among the four 20MHz channels corresponding to the position of the auxiliary 80MHz channel within the main 160MHz channel f) a sixth 20 MHz channel corresponding to the position of the auxiliary 20 MHz channel in the main 80 MHz channel among the four 20 MHz channels corresponding to the position of the auxiliary 80 MHz channel in the main 160 MHz channel; g) a seventh 20 MHz channel corresponding to the position of the main 20 MHz channel in the main 40 MHz channel among the two 20 MHz channels corresponding to the position of the auxiliary 40 MHz channel in the main 80 MHz channel among the four 20 MHz channels corresponding to the position of the auxiliary 80 MHz channel in the main 160 MHz channel; and h) an eighth 20 MHz channel corresponding to the position of the auxiliary 20 MHz channel in the main 40 MHz channel among the two 20 MHz channels corresponding to the position of the auxiliary 40 MHz channel in the main 80 MHz channel among the four 20 MHz channels corresponding to the position of the auxiliary 80 MHz channel in the main 160 MHz channel.

[0175] Additionally or alternatively, the at least one field in the above step S910 may include a third field indicating a specific 20 MHz channel in the secondary channel to which the first STA is allocated. That is, the specific 20 MHz channel may be explicitly indicated.

[0176] Fig. 9 The method performed by the first STA described in the example of Figure 1 The first device (100) performs. For example, Figure 1One or more processors (102) of the first device (100) can receive a frame including at least one field related to a channel for SST operation from a second STA (200) through one or more transceivers (106), and can be configured to perform SST operation on the corresponding channel based on the at least one field.

[0177] For example, one or more processors (102) of the first device (100) may decode at least one field included in the received frame. That is, the one or more processors (102) may be configured to decode one or more fields included in the SST operation element format to determine the channel on which the SST operation is to be performed.

[0178] As a specific example, one or more processors (102) can identify the location of a channel for SST operation by decoding a first field (e.g., an SST activation channel bitmap field) and a second field, the first field including bandwidth-related information included in a corresponding frame, bitmap information related to channel activation, and the second field being related to the resolution used for the corresponding bitmap information. In addition, one or more processors (102) can be configured to identify the location of a class main channel for sending and receiving control / management frames on a secondary channel to which the first device is assigned. To this end, one or more processors (102) can be configured to decode explicit indication information included in the corresponding frame, or identify the location of a class main channel implicitly indicated based on predefined rules. One or more processors (102) can be configured to control SST operations on a channel identified based on the above method.

[0179] In addition, one or more memories (104) of the first device (100) may store instructions for executing the operation when executed by one or more processors (102). Fig. 9 Examples or commands of the methods described in the examples described below.

[0180] Fig.10 is a diagram for explaining the operation of the second STA in the SST operation according to the present disclosure.

[0181] In step S1010 , the second STA may construct a frame including at least one field related to a channel for SST operation.

[0182] Here, at least one field may include a first field (e.g., an SST activation channel bitmap field) and a second field (e.g., a resolution field), the first field including bitmap information related to the activation of the corresponding channel, and the second field indicating the resolution to be applied to the corresponding bitmap information.

[0183] At this time, the second field may be defined to indicate one of a plurality of predefined resolution candidates.

[0184] In step S1020, the second STA may send a frame including at least one field to the first STA.

[0185] exist Fig.10 In the example of , at least one field related to SST operation (e.g., a first field, a second field, a third field, etc.), specific details about a specific 20 MHz channel (e.g., a primary channel-like channel), etc. Fig. 9 The examples are the same as those described in , so redundant descriptions are omitted.

[0186] Fig.10 The method performed by the second STA described in the example of Figure 1 The second device (200) is executed. For example, Figure 1 One or more processors (202) of the second device (200) may be configured to configure a frame including at least one field related to a channel for SST operation, and send the frame including the at least one field to the first STA (100) through one or more transceivers (206).

[0187] For example, one or more processors (202) of the second device (200) may decode the frame by encoding at least one field related to the channel for SST operation. That is, one or more processors (202) may be configured to encode one or more fields of the SST operation element format to construct a frame for indicating / configuring SST operation.

[0188] As a specific example, one or more processors (202) may encode a first field including bandwidth-related information, bitmap information related to channel activation (e.g., an SST activation channel bitmap field), and a second field related to the resolution used for the bitmap information to configure / indicate the location of the channel for SST operation. In addition, one or more processors (202) may configure the location of a class main channel for sending and receiving control / management frames on the secondary channel to which the first device is assigned. Alternatively, the location of the class main channel may be predefined / configured by adjustment. One or more processors (202) may be configured to configure / indicate SST operation in the first STA (100) based on the above method.

[0189] In addition, the one or more memories (204) of the second device (200) may store instructions for executing the operation when executed by the one or more processors (202). Fig.10 Examples or instructions of the methods described in the examples described below.

[0190] Fig. 9 and Fig.10 The SST operation element format described in the example can correspond to Figure 8 The SST operation element format is compared to an extended / modified SST operation element format including one or more additional, modified, or excluded fields.

[0191] Fig. 9 and Fig.10 Examples of may correspond to some examples of various examples of the present disclosure. In the following, various examples of the present disclosure will be described, including Fig. 9 and Fig.10 .

[0192] First, a specific method for allocating channels for SST operation in consideration of a wide bandwidth is described.

[0193] For example, a method of defining a new SST operation element (e.g., an enhanced SST operation element) using a new element ID may be considered. The new SST operation element may be similar to an existing SST operation element (e.g., Figure 8 The SST operation element format is composed of fields.

[0194] In this regard, the number of bits of the SST activation channel bitmap field can be determined according to the maximum bandwidth to be defined in the next generation wireless LAN system (e.g., UHR, etc.). For example, when the maximum bandwidth is 320MHz / 480MHz / 640MHz, the number of bits of the SST activation channel bitmap field can be 16 / 24 / 32.

[0195] Alternatively, the number of bits of the SST activation channel bitmap field can be fixed, and the resolution field can be newly defined. The resolution field can be defined to indicate the resolution of the SST activation channel bitmap field. For example, the number of bits of the SST activation channel bitmap field can be fixed to 16 bits, and the resolution field can be configured / defined as 1 bit. In this case, a value of 0 in the resolution field can be defined to indicate a resolution of 20 MHz, and a value of 1 can be defined to indicate a resolution of 40 MHz.

[0196] As another example, consider reusing existing SST operation elements (e.g., Figure 8 Methods for operating on SST elements in .

[0197] The resolution in the existing SST activation channel bitmap field is limited to a maximum of 20 MHz. In contrast, the SST operation element proposed in the present disclosure can consider methods for defining and utilizing additional resolutions. For example, it can be defined to utilize resolutions such as 40 MHz / 80 MHz.

[0198] Alternatively, the existing reserved fields can be used to newly define the resolution field. The resolution field can indicate the resolution of the SST activation channel bitmap field. Here, the resolution field can be configured / defined as 1 bit or 2 bits. For example, 1 bit can be set / defined when the maximum bandwidth is defined as up to 320MHz bandwidth, and 2 bits can be set / defined when the maximum bandwidth is defined as up to 480MHz / 640MHz bandwidth.

[0199] For example, if the resolution field is configured with 1 bit, a value of 0 may indicate a 20 MHz resolution, a value of 1 may indicate a 40 MHz resolution, etc. If the resolution field is configured with 2 bits, a value of 0 may indicate a 20 MHz resolution, a value of 1 may indicate a 40 MHz resolution, a value of 2 may indicate an 80 MHz resolution, and a value of 3 may be reserved.

[0200] Next, a method for configuring a master-like channel to manage efficient SST operation is described.

[0201] For example, the indication about the position of the channel may be performed by defining a specific field to indicate the position of a primary-like channel (eg, a 20 MHz channel).

[0202] At this point, when reusing existing SST operation elements (e.g. Figure 8 When defining an SST operation element format (e.g., an enhanced SST operation element), a reserved field may be used to define a field for indicating the location of a class main channel. Alternatively, when defining a new SST operation element (e.g., an enhanced SST operation element), the SST operation element may be defined to include a field for indicating the location of a class main channel.

[0203] As another example, to reduce the overhead of adding fields and simplify implementation, a class primary channel may be configured / defined to be implicitly indicated.

[0204] One or more of the following various examples may be considered to implicitly indicate a primary-like channel.

[0205] For example, the first or last 20 MHz channel of the secondary channel to which the STA is assigned may be used as a quasi-primary channel.

[0206] If the channel is punctured, the first or last 20MHz channel that is not punctured can be used as a quasi-primary channel. At this time, the puncturing-related information can be indicated by a beacon or the like.

[0207] As another example, a 20 MHz channel located at a point corresponding to the position of P20 (ie, a primary 20 MHz channel within the secondary channel) may be used as a quasi-primary channel.

[0208] That is, considering the main channel of the same size as the allocated channel (ie, the allocated secondary channel), the 20MHz channel located at the point corresponding to the position of P20 can be defined as being used as a quasi-main channel. At this time, the STA can confirm / be indicated the position of P20 of the BSS and the positions of all main / secondary channels through a beacon, etc.

[0209] As a specific example, if the STA is assigned to the secondary 160MHz channel (ie, S160), the 20MHz channel located at a point corresponding to the P20 position in the primary 160MHz channel (ie, P160) within S160 can be used as a quasi-primary channel. As another specific example, if the STA is assigned to the primary 80MHz channel, i.e., a specific 80MHz channel other than P80, the 20MHz channel within the assigned 80MHz located at a point corresponding to the P20 position in P80 can be used as a quasi-primary channel.

[0210] Regarding the above example, if the 20 MHz channel at that location is punctured, the following alternative approach may be applied.

[0211] For example, the 20MHz channel closest to the location can be used as the quasi-primary channel. In this case, if there are two 20MHz channels at the nearest location, the 20MHz channel with a higher frequency or the 20MHz channel with a lower frequency can be used as the quasi-primary channel.

[0212] As another example, the nearest 20MHz channel in the high or low direction can be used as a quasi-primary channel. In this case, if all 20MHz channels in the corresponding direction are punctured, a cyclic shift can be applied so that the next unpunctured 20MHz channel can be used as a quasi-primary channel.

[0213] As another example, a secondary 20 MHz channel, ie, a 20 MHz channel located at a point corresponding to the position of S20, may be used as a quasi-primary channel.

[0214] If the 20MHz channel is punctured, then among the two 20MHz channels located at the point corresponding to the position of the auxiliary 40MHz channel (i.e., S40), the 20MHz channel located at the point corresponding to the position of P20 within the main 40MHz (i.e., P40) can be used as a quasi-primary channel. Additionally or alternatively, if the 20MHz channel is punctured, then among the two 20MHz channels located at the point corresponding to the position of S40, the 20MHz channel located at the point corresponding to the position of S20 within P40 can be used as a quasi-primary channel.

[0215] When allocated to a specific channel having a size of 40 MHz or less other than P40, the above-described S40-based method, the below-described S80-based method, and the S160-based method may not be applicable.

[0216] If the 20MHz channel is punctured, then among the four 20MHz channels located at the points corresponding to the positions of the auxiliary 80MHz channels (i.e., S80), the 20MHz channel located at the point corresponding to the position of P20 within the primary 80MHz (i.e., P80) can be used as a quasi-primary channel. Additionally or alternatively, if the 20MHz channel is punctured, then among the four 20MHz channels located at the points corresponding to the positions of S80, the 20MHz channel located at the point corresponding to the position of S20 within P80 can be used as a quasi-primary channel.

[0217] Additionally or alternatively, when the 20 MHz channel is punctured, among the two 20 MHz channels located at the point corresponding to the position of S40 within P80 among the four 20 MHz channels located at the point corresponding to the position of S80, the 20 MHz channel located at the point corresponding to the position of P20 within P40 may be used as a quasi-main channel. Additionally or alternatively, when the 20 MHz channel is punctured, among the two 20 MHz channels located at the point corresponding to the position of S40 within P80 among the four 20 MHz channels located at the point corresponding to the position of S80, the 20 MHz channel located at the point corresponding to the position of S20 within P40 may be used as a quasi-main channel.

[0218] When allocated to a specific 80 MHz or smaller channel other than P80, the above-mentioned S80-based method and the below-mentioned S160-based method may not be applicable.

[0219] If the 20MHz channel is punctured, then among the eight 20MHz channels located at the points corresponding to the positions of the auxiliary 160MHz channels (i.e., S160), the 20MHz channel located at the point corresponding to the position of P20 within the primary 160MHz (i.e., P160) may be used as a quasi-primary channel. Additionally or alternatively, if the 20MHz channel is punctured, then among the eight 20MHz channels located at the points corresponding to the positions of S160, the 20MHz channel located at the point corresponding to the position of S20 within P160 may be used as a quasi-primary channel.

[0220] Additionally or alternatively, when the 20 MHz channel is punctured, among the two 20 MHz channels located at the point corresponding to the position of S40 within P160 among the eight 20 MHz channels located at the point corresponding to the position of S160, the 20 MHz channel located at the point corresponding to the position of P20 within P40 may be used as a quasi-main channel. Additionally or alternatively, when the 20 MHz channel is punctured, among the two 20 MHz channels located at the point corresponding to the position of S40 within P160 among the eight 20 MHz channels located at the point corresponding to the position of S160, the 20 MHz channel located at the point corresponding to the position of S20 within P40 may be used as a quasi-main channel.

[0221] Additionally or alternatively, if the 20 MHz channel is punctured, then among the four 20 MHz channels located at the point corresponding to the position of S80 within P160 among the eight 20 MHz channels located at the point corresponding to the position of S160, the 20 MHz channel located at the point corresponding to the position of P20 within P80 may be used as a quasi-main channel. Additionally or alternatively, if the 20 MHz channel is punctured, then among the four 20 MHz channels located at the point corresponding to the position of S80 within P160 among the eight 20 MHz channels located at the point corresponding to the position of S160, the 20 MHz channel located at the point corresponding to the position of S20 within P80 may be used as a quasi-main channel. Additionally or alternatively, if the 20MHz channel is punctured, then among the eight 20MHz channels located at the point corresponding to the position of S160, among the four 20MHz channels located at the point corresponding to the position of S80 within P160, among the two 20MHz channels located at the point corresponding to the position of P40 within P80, the 20MHz channel located at the point corresponding to the position of P20 within P40 may be used as a quasi-main channel. Additionally or alternatively, if the 20MHz channel is punctured, among the eight 20MHz channels located at the point corresponding to the position of S160, among the four 20MHz channels located at the point corresponding to the position of S80 within P160, among the two 20MHz channels located at the point corresponding to the position of S20 within P40, the 20MHz channel located at the point corresponding to the position of P40 within P80 may be used as a quasi-main channel.

[0222] When allocating to a specific 160 MHz or smaller channel other than P160, the above-mentioned S160-based method may not be applicable.

[0223] For the primary-like channel according to the method proposed in the present disclosure, a 20 MHz channel within a specific channel can be configured as a primary-like channel. For example, a 20 MHz channel within a 40 MHz channel, an 80 MHz channel, a 160 MHz channel and / or a 320 MHz channel can be configured / indicated as a primary-like channel.

[0224] Alternatively, considering the complexity, the primary channel may be configured / indicated only in the large channel unit. For example, a 20MHz channel may be configured / indicated as a primary channel in each 80MHz channel, 160MHz channel, or 320MHz channel. In this case, the channel unit to which the STA is allocated by the SST may be only an 80MHz channel, a 160MHz channel, or a 320MHz channel.

[0225] In the existing wireless LAN system, the SST operation is defined only within the 160MHz bandwidth. In addition, in the case of the existing SST operation, there is no channel through which the STA assigned to the auxiliary channel can send and receive control / management frames. In contrast, the method proposed in the present disclosure can set / indicate the SST operation by considering the 320MHz bandwidth and the wide bandwidth (for example, 480MHz / 640MHz bandwidth), and has a new feature of configuring / indicating a main-like channel, and the STA assigned to the auxiliary channel can send and receive control / management frames through the main-like channel. According to the method proposed in the present disclosure, the resolution of the channel for SST operation can be configured, so that the efficiency of channel operation can be improved. In addition, according to the method proposed in the present disclosure, there is a new effect that the STA assigned to the auxiliary channel can also send and receive control / management frames by considering the SST operation. In addition, by supporting the SST operation considering the wide bandwidth according to the method proposed in the present disclosure, a new effect of improving throughput and efficiency can be achieved.

[0226] The above-mentioned embodiments are to combine the elements and features of the present disclosure in a predetermined form. Unless otherwise explicitly mentioned, each element or feature should be regarded as optional. Each element or feature can be implemented in a form that is not combined with other elements or features. In addition, the embodiments of the present disclosure may include a combination of some elements and / or features. The order of the operations described in the embodiments of the present disclosure may be changed. Some elements or features of an embodiment may be included in other embodiments, or may be replaced by corresponding elements or features of other embodiments. Obviously, the embodiments may include claims that do not have a clear reference relationship in the combined claims, or may be included as new claims by modification after application.

[0227] It is clear to those skilled in the relevant art that the present disclosure can be implemented in other specific forms within the scope of the essential features of the present disclosure. Therefore, the above detailed description should not be interpreted restrictively in every aspect, but should be considered as illustrative. The scope of the present disclosure should be determined by the reasonable interpretation of the attached claims, and all changes within the equivalent scope of the present disclosure are included in the scope of the present disclosure.

[0228] The scope of the present disclosure includes software or machine executable commands (e.g., operating systems, applications, firmware, programs, etc.) that perform operations in a device or computer according to the methods of various embodiments, and non-transitory computer-readable media that enable software or commands, etc. to be stored and executable in a device or computer. Commands that can be used to program a processing system that performs the features described in the present disclosure can be stored in a storage medium or a computer-readable storage medium, and the features described in the present disclosure can be implemented by using a computer program product that includes such a storage medium. The storage medium may include a high-speed random access memory, such as, for example, DRAM, SRAM, DDR RAM, or other random access solid-state storage devices, but is not limited thereto, and it may include non-volatile memory, such as, for example, one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory optionally includes one or more storage devices located away from the processor. The memory, or alternatively, the non-volatile memory device in the memory includes a non-transitory computer-readable storage medium. The features described in this disclosure may be stored in any machine-readable medium to control the hardware of a processing system, and may be integrated into software and / or firmware that allows the processing system to interact with other mechanisms using the results from the embodiments of this disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0229] Industrial Applicability

[0230] The method proposed in the present disclosure is mainly described based on an example applied to a system based on IEEE 802.11 (5G system), but can be applied to various WLAN or wireless communication systems other than the system based on IEEE 802.11.

Claims

1. A method performed by a first station STA in a wireless LAN system, the method comprising the following steps: receiving, from a second STA, a frame including at least one field related to a channel for a subchannel selective transmission (SST) operation; as well as performing an SST operation on the channel based on the at least one field, wherein the at least one field includes a first field and a second field, the first field including bitmap information related to activation of the channel, the second field indicating a resolution to be applied to the bitmap information, and The second field is defined to indicate one of a plurality of predefined resolution candidates.

2. The method according to claim 1, in, The plurality of resolution candidates are defined to include at least two of a 20 MHz resolution, a 40 MHz resolution, or an 80 MHz resolution.

3. The method according to claim 2, in, Based on the maximum bandwidth associated with SST operation being 320 MHz, the second field is configured with 1 bit, and The first value according to the 1 bit is defined to indicate a 20 MHz resolution, and the second value according to the 1 bit is defined to indicate a 40 MHz resolution.

4. The method according to claim 2, in, Based on the maximum bandwidth associated with the SST operation being 480 MHz bandwidth or 640 MHz bandwidth, the second field is configured with 2 bits, and Among them, the first value according to the 2 bits is defined as indicating a 20MHz resolution, the second value according to the 2 bits is defined as indicating a 40MHz resolution, the third value according to the 2 bits is defined as indicating an 80MHz resolution, and the fourth value according to the 2 bits is defined as a reserved value.

5. The method according to claim 1, in, The number of bits of the first field is variably set based on the size of a maximum bandwidth associated with the SST operation.

6. The method according to claim 1, in, The step of performing the SST operation includes performing transmission and reception of a control frame or a management frame on a specific 20 MHz channel within a secondary channel to which the first STA is allocated.

7. The method according to claim 6, in, The specific 20 MHz channel corresponds to a 20 MHz channel located at a point within the secondary channel corresponding to a position of a primary 20 MHz channel of a basic service set BSS to which the first STA belongs.

8. The method according to claim 7, in, The location of the primary 20 MHz channel, the location of a primary channel including the primary 20 MHz channel, and the location of the secondary channel are identified through the beacon received by the first STA.

9. The method according to claim 7, in, Based on the 20 MHz channel being punctured, the specific 20 MHz channel corresponds to a 20 MHz channel located at a point within the secondary channel corresponding to a position of a secondary 20 MHz channel of the BSS to which the first STA belongs.

10. The method according to claim 9, in, Based on the puncturing of the 20 MHz channel within the secondary channel, the specific 20 MHz channel is configured as one of the two 20 MHz channels corresponding to the position of the secondary 40 MHz channel according to a predefined rule.

11. The method according to claim 10, in, The two 20MHz channels include: a first 20 MHz channel corresponding to a location of a primary 20 MHz channel within the primary 40 MHz channel; and A second 20 MHz channel, the second 20 MHz channel corresponding to the position of the secondary 20 MHz channel within the primary 40 MHz channel.

12. The method according to claim 10, in, Based on the two 20 MHz channels being punctured, the specific 20 MHz channel is configured as one of four 20 MHz channels corresponding to the position of the secondary 80 MHz channel according to a predefined rule.

13. The method according to claim 12, in, The four 20MHz channels include: a first 20 MHz channel, the first 20 MHz channel corresponding to a position of a primary 20 MHz channel within the primary 80 MHz channel; a second 20 MHz channel corresponding to a position of the secondary 20 MHz channel within the primary 80 MHz channel; a third 20 MHz channel, among the two 20 MHz channels corresponding to the position of the secondary 40 MHz channel within the primary 80 MHz channel, the third 20 MHz channel corresponding to the position of the primary 20 MHz channel within the primary 40 MHz channel; and A fourth 20 MHz channel, among the two 20 MHz channels corresponding to the position of the secondary 40 MHz channel within the primary 80 MHz channel, the fourth 20 MHz channel corresponds to the position of the secondary 20 MHz channel within the primary 40 MHz channel.

14. The method according to claim 12, in, Based on the four 20 MHz channels being punctured, the specific 20 MHz channel is configured as one of the eight 20 MHz channels corresponding to the position of the secondary 160 MHz channel according to a predefined rule.

15. The method according to claim 14, in, The eight 20MHz channels include: a first 20 MHz channel, the first 20 MHz channel corresponding to a position of a primary 20 MHz channel within the primary 160 MHz channel; a second 20 MHz channel corresponding to a position of the secondary 20 MHz channel within the primary 160 MHz channel; a third 20 MHz channel, among the two 20 MHz channels corresponding to the position of the secondary 40 MHz channel within the primary 160 MHz channel, the third 20 MHz channel corresponding to the position of the primary 20 MHz channel within the primary 40 MHz channel; a fourth 20 MHz channel, among the two 20 MHz channels corresponding to the position of the secondary 40 MHz channel within the primary 160 MHz channel, the fourth 20 MHz channel being at a position corresponding to the secondary 20 MHz channel within the primary 40 MHz channel; a fifth 20 MHz channel, among the four 20 MHz channels corresponding to the positions of the secondary 80 MHz channels within the primary 160 MHz channel, the fifth 20 MHz channel corresponding to the position of the primary 20 MHz channel within the primary 80 MHz channel; a sixth 20 MHz channel, among the four 20 MHz channels corresponding to the position of the secondary 80 MHz channel within the primary 160 MHz channel, the sixth 20 MHz channel corresponding to the position of the secondary 20 MHz channel within the primary 80 MHz channel; a seventh 20 MHz channel, corresponding to a position of a primary 20 MHz channel within the primary 40 MHz channel among two 20 MHz channels corresponding to a position of a secondary 40 MHz channel within the primary 80 MHz channel among the four 20 MHz channels corresponding to a position of a secondary 80 MHz channel within the primary 160 MHz channel; and The eighth 20 MHz channel corresponds to the position of the auxiliary 40 MHz channel in the main 80 MHz channel among the two 20 MHz channels corresponding to the position of the auxiliary 80 MHz channel in the main 160 MHz channel. The eighth 20 MHz channel corresponds to the position of the auxiliary 20 MHz channel in the main 40 MHz channel.

16. The method according to claim 6, in, The specific 20 MHz channel is configured in a secondary channel whose channel unit is greater than or equal to 80 MHz.

17. The method according to claim 6, in, The at least one field includes a third field indicating a specific 20 MHz channel within a secondary channel to which the first STA is assigned.

18. A device for a first station STA in a wireless local area network (WLAN) system, the device comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: receiving, from a second STA, a frame including at least one field related to a channel for a subchannel selective transmission (SST) operation; and performing an SST operation on the channel based on the at least one field, wherein the at least one field includes a first field and a second field, the first field including bitmap information related to activation of the channel, the second field indicating a resolution to be applied to the bitmap information, and The second field is defined to indicate one of a plurality of predefined resolution candidates.

19. A method performed by a second station (STA) in a wireless LAN system, the method comprising the following steps: constructing a frame including at least one field associated with a channel for subchannel selective transmission (SST) operation; as well as sending the frame including the at least one field to a first STA, wherein the at least one field includes a first field and a second field, the first field including bitmap information related to activation of the channel, the second field indicating a resolution to be applied to the bitmap information, and The second field is defined to indicate one of a plurality of predefined resolution candidates.

20. A device for a second station STA in a wireless local area network (WLAN) system, the device comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: constructing a frame including at least one field associated with a channel for subchannel selective transmission (SST) operation; and sending the frame including the at least one field to a first STA, wherein the at least one field includes a first field and a second field, the first field including bitmap information related to activation of the channel, the second field indicating a resolution to be applied to the bitmap information, and The second field is defined to indicate one of a plurality of predefined resolution candidates.

21. A processing unit configured to control a station STA in a wireless local area network (WLAN) system, the processing unit comprising: at least one processor; as well as At least one computer memory operatively connected to the at least one processor, the at least one computer memory storing instructions for performing the method according to any one of claims 1 to 17 upon execution by the at least one processor.

22. At least one non-transitory computer-readable medium storing at least one instruction, wherein: The at least one instruction is executed by at least one processor to control a device to perform the method according to any one of claims 1 to 17 in a wireless local area network (WLAN) system.

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