Method and apparatus for transmitting and receiving aggregated physical layer protocol data unit in wireless LAN system

Abstract

Disclosed are a method and an apparatus for operation in a wireless LAN system. A method performed by a first STA in a wireless LAN system according to an embodiment disclosed herein may comprise the steps of: receiving an aggregated physical layer protocol data unit (A-PPDU) header from a second STA; and receiving the A-PPDU from the second STA based on the A-PPDU header, where the A-PPDU header includes first information related to at least one frequency resource unit for latency sensitive (LS) data transmission and second information related to timing for LS data transmission.

Description

Technical Field

[0001] The present disclosure relates to communication operations in a wireless local area network (WLAN) system, and more particularly, to a method and apparatus for transmitting and receiving polymer physical layer protocol data units (PPDUs) in a next generation wireless LAN system. Background Art

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

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

[0004] Technical issues

[0005] A technical problem of the present disclosure is to provide a method and apparatus for performing A(Aggregation)-PPDU transmission and reception in a wireless LAN system.

[0006] A technical problem of the present disclosure is to provide a method and apparatus for indicating a channel for transmitting DLA-PPDU header information and a delay service based on a DL (Downlink) A-PPDU header.

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

[0008] Technical Solution

[0009] According to one embodiment of the present disclosure, a method performed by a first station (STA) in a wireless LAN system may include: receiving an aggregate physical layer protocol data unit (A-PPDU) header from a second STA; and receiving the A-PPDU from the second STA based on the A-PPDU header, and the A-PPDU header may include first information related to at least one frequency resource unit for delay-sensitive (LS) data transmission and second information related to timing for LS data transmission.

[0010] According to one embodiment of the present disclosure, a method performed by a second station (STA) in a wireless LAN system may include: sending an aggregate physical layer protocol data unit (A-PPDU) header from a first STA; and sending the A-PPDU to the first STA based on the A-PPDU header, wherein the A-PPDU header may include first information related to at least one frequency resource unit for delay-sensitive (LS) data transmission and second information related to timing for LS data transmission.

[0011] Technical Effects

[0012] According to various embodiments of the present disclosure, a method and apparatus for efficiently performing A-PPDU transmission and reception in a wireless LAN system may be provided.

[0013] According to various embodiments of the present disclosure, a method and apparatus for indicating DL A-PPDU header information and a channel for delayed service transmission based on the DL A-PPDU header may be provided.

[0014] 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

[0015] The accompanying drawings, which are included as a part of the detailed description for understanding the present disclosure, provide embodiments of the present disclosure and describe technical features of the present disclosure together with the detailed description.

[0016] Figure 1 A configuration block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0017] Figure 2 is a diagram illustrating an exemplary structure of a WLAN system to which the present disclosure can be applied.

[0018] Figure 3 It is a diagram for explaining a link establishment process to which the present disclosure can be applied.

[0019] Figure 4 This is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0020] Figure 5 It is a diagram for explaining a frame transmission operation based on CSMA / CA to which the present disclosure can be applied.

[0021] 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.

[0022] 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.

[0023] Figure 8 This is a diagram for explaining the structure of an A-PPDU to which the present disclosure can be applied.

[0024] Fig. 9 and Fig.10 is a diagram for explaining a method for transmitting an A-PPDU and an intercepted PPDU according to an embodiment of the present disclosure.

[0025] Fig.11 is a diagram illustrating an example of a sub-channel selective transmission (SST) operation element format to which the present disclosure may be applied.

[0026] Fig.12 is a flowchart for explaining a method for a first STA to transmit and receive a PPDU according to an embodiment of the present disclosure.

[0027] Fig.13 is a flowchart for explaining a method for a second STA to transmit and receive a PPDU according to an embodiment of the present disclosure.

[0028] Fig.14 2 is a diagram for explaining an A-PPDU header and an A-PPDU transmission process according to an embodiment of 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, the STAs 110 and 200 may perform an access point (AP) role or a non-AP role. That is, in the present disclosure, the STAs 110 and 200 may perform the functions of an AP and / or a non-AP. When the STAs 110 and 200 perform the AP function, they may be simply referred to as APs, and when the STAs 110 and 200 perform the non-AP function, they may be simply referred to as STAs. 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 medium 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 performing a backoff after DIFS has passed, and if it is a response frame of the previous frame, it is sent without performing a backoff after a short IFS (SIFS) has passed. The type and subtype of the frame can be identified by the type field and subtype field in the frame control (FC) field.

[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 frame transmission operation based on CSMA / CA, 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 HEPPDUs, 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 this information may indicate the PHY version (e.g., EHT, UHR, etc.) of the transmitted / received PPDU. The version-independent bits of the U-SIG may include a 1-bit UL / DL flag field. The first value of the 1-bit UL / DL flag field is related to UL communication, and the second value of the UL / DL flag field is related to DL communication. The version-independent bits of the U-SIG may include information about the length of a transmit opportunity (TXOP) and information about a BSS color ID.

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

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

[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] Structure of Aggregate PPDU (A-PPDU)

[0131] To improve efficiency and throughput in wireless LAN systems, A-PPDU transmission may be defined, in which PPDUs of different formats / versions are sent simultaneously.

[0132] A-PPDU may correspond to a new format that combines multiple PPDU formats in the frequency domain. Figure 8 In A-PPDU transmission, a first sub-PPDU (S-PPDU) format may be sent in a first frequency band (e.g., 160 MHz), a second S-PPDU format may be sent in a second frequency band (e.g., 80 MHz), and a third S-PPDU format may be sent in a third frequency band (e.g., 80 MHz).

[0133] However, this is merely one embodiment, and in A-PPDU transmission, a first S-PPDU format may be transmitted in a first frequency band, and a second S-PPDU format may be transmitted in a second frequency band.

[0134] Each S-PPDU constituting the A-PPDU may be a PPDU of a different format. For example, each S-PPDU may be one of a HEPPDU, an EHT PPDU, and a PPDU of a new format after EHT (hereinafter referred to as "UHR") (ie, a PPDU of the next version).

[0135] Here, each of the HE PPDU, the EHT PPDU, and the UHR PPDU may include a HE MU PPUD, an EHT MU PPUD, and a UHR MU PPDU. The UHR MU PPDU may have a structure similar to that of the EHT MU PPDU of OFDMA transmission or MU MIMO transmission. However, a dependent field of the U-SIG field of the UHR MU PPDU may be different from a dependent field of the U-SIG field of the EHT MU PPDU. In addition, the EHT MU PPUD may include a UHR SIG field instead of an EHT SIG field.

[0136] Intercepted A-PPDU

[0137] A STA may have a transmission opportunity (TXOP). Here, a TXOP refers to a time interval during which a particular STA may have the right to initiate a frame exchange sequence on the wireless medium (WM). A TXOP may be defined by a start time (during which a STA may have the right) and a maximum duration value.

[0138] For example, Fig. 9 As shown in (a), it is assumed that during the TXOP, delay-sensitive (LS) traffic arrives when the STA is sending non-LS traffic. If the STA continues to send non-LS traffic within the TXOP, the transmission of the LS traffic must wait until the end of the TXOP, thus requiring channel contention.

[0139] In order to reduce the delay of LS services, a preemptible PPDU can be introduced. Therefore, in the current TXOP (i.e., Fig. 9 The transmitting STA may terminate the ongoing PPDU after the most recent segment with the PPDU end marker. The PPDU end marker may be a rotation of other predefined sequences or L-LTFs.

[0140] For example, Fig. 9 As shown in (b), when the LS service arrives at the same time as PPDU-3 is sent in the 80 MHz bandwidth, PPDU-4 based on the LS service can be sent within the bandwidth.

[0141] As an example of the present disclosure, for a non-LS PPDU having a length of 4 ms, the transmitting STA may choose to interrupt the transmission and reallocate the TXOP to LS traffic.

[0142] For this purpose, Fig. 9 As shown in (c), when the LS service does not arrive, the PHY layer can encode the 4ms PPDU payload into 4 PPDU payloads (ie, each PPDU payload is 1ms).

[0143] like Fig. 9 As shown in (d), when LS traffic arrives during the transmission of non-LS traffic, the PHY layer may terminate the transmission of the non-LS traffic at the nearest boundary with the PPDU end marker. The receiving STA may forward the received segment to the upper layer.

[0144] In another example of the present disclosure, the transmitting STA may choose to terminate the ongoing transmission and then send the LS traffic.

[0145] For example, Fig.10 As shown in (a), if non-LS traffic has not arrived, the PHY layer can encode the PPDU and wait for ACK reception.

[0146] like Fig.10 As shown in (b), when LS traffic arrives during the transmission of non-LS traffic, the PHY layer can insert a PPDU sequence end marker at the end of the PPDU. Accordingly, subsequent frame exchange can be stopped, and the transmitting STA can send LS traffic.

[0147] If a PPDU sequence end marker is detected at the end of a PPDU, the receiving STA may expect to receive a LS PPDU after SIFS without sending a BA.

[0148] In another example of the present disclosure, the transmitting STA may choose to immediately stop the currently ongoing transmission.

[0149] For example, Fig.10 As shown in (c), if the LS service has not arrived, the PHY layer can encode the PPDU and wait for ACK reception.

[0150] like Fig.10 As shown in (d), when LS traffic arrives, the PHY layer can stop the current transmission with the PPDU end marker and send the LS traffic after SIFS. The receiving STA can remove all or part of the received bits according to whether a complete MPDU has been received.

[0151] SST (Subchannel Selective Transmission)

[0152] 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 full bandwidth.

[0153] As an example of the present disclosure, it can be based on Fig.11 SST is applied by using the subchannel selective transmission (SST) operation element illustrated in FIG.

[0154] 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 reserved bits.

[0155] The element ID field is used to identify the element of the format, and the length field may indicate the number of octets of the element excluding the element ID field and the length field.

[0156] The SST Enable Channel Bitmap field may include a bitmap indicating channels enabled for SST operation. Each bit of the bitmap corresponds to a channel having the same width as the value of the SST Channel Units field, and the least significant bit (LSB) may correspond to the lowest numbered subchannel in the SST Enable Channel Bitmap field.

[0157] The channel number of each channel in the SST Enabled Channels 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 specified by the value of the Primary Channel Offset field. POS is the position of the channel in the bitmap.

[0158] Setting a bit position in the bitmap to 1 may indicate that the subchannel is enabled for SST operation, but transmissions from SST STAs on that subchannel are allowed according to the rules defined in the specification. One or more bits in the bitmap may be equal to 1.

[0159] The Primary Channel Offset field may indicate the relative position of the primary channel relative to the lowest numbered channel in the SST Enabled Channels 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 Enabled Channels Bitmap.

[0160] The SST Channel Unit field may indicate the channel width unit of each SST channel. Setting the field to 1 may indicate that the channel width unit is 1 MHz, and setting the field to 2 may indicate that the channel width unit is 2 MHz.

[0161] Hereinafter, the structure of the A-PPDU header and the process related thereto as an embodiment of the present disclosure are described so that the intercepted A-PPDU transmission can be used to solve the transmission delay problem of delay-sensitive services.

[0162] A-PPDU sending and receiving method based on A-PPDU header

[0163] As described above, an intercepted A-PPDU may be introduced to prevent delays in A-PPDU transmission. This is a method of sending LS traffic within an A-PPDU through a specific channel using a preemptible PPDU consolidation method when LS traffic arrives during A-PPDU transmission.

[0164] For example, the above method may include a method in which sub-PPDU transmission of a STA in which LS traffic has occurred among STAs allocated for each sub-PPDU transmission within an A-PPDU is stopped, and the LS traffic is sent to the STA in the form of an intercepted PPDU using a corresponding channel. In the case of the above method, an instruction on a channel to be used for sending an intercepted PPDU during A-PPDU transmission may not be required.

[0165] However, if no sub PPDU is transmitted to the STA where the LS traffic has occurred, a specific channel for transmitting the intercepted PPDU may need to be determined in advance.

[0166] Additionally or alternatively, the STA may indicate in advance that a specific sub-PPDU within the A-PPDU is short and thus the channel may be used for LS traffic transmission from a specific timing.

[0167] Additionally or alternatively, a specific channel may be configured / defined to be used only for LS traffic transmission when sending an A-PPDU. For example, only a dummy signal may be sent on a specific channel and may be used for LS traffic transmission only when LS traffic occurs.

[0168] Fig.12 1 is a flowchart for explaining a method for a first STA to transmit and receive a PPDU according to one embodiment of the present disclosure. Fig.12 and Fig.13 In the embodiment, each of the first STA and the second STA may be one of the APs among the non-AP STAs.

[0169] The first STA may receive an aggregate physical layer protocol data unit (A-PPDU) header from the second STA (S1210).

[0170] Here, the A-PPDU header may include first information related to at least one frequency resource unit for delay sensitive (LS) data transmission and second information related to timing for LS data transmission.

[0171] As an example of the present disclosure, the first information may be received from the second STA via a U (Universal)-SIG field or a UHR (Ultra High Reliability) field of an A-PPDU header.

[0172] For example, the first information may be indicated via a Delay Sensitive Traffic Transport Channel field included in a U-SIG field of an A-PPDU header. That is, a channel capable of transmitting LS data may be indicated via the Delay Sensitive Traffic Transport Channel field.

[0173] Here, based on the absence of LS data (ie, when LS data does not arrive), a dummy signal may be transmitted through a specific channel indicated by the first information.

[0174] For example, based on the allocation of a specific channel through information related to subchannel selective transmission, the specific channel may be indicated as a channel for LS data transmission through first information included in a U-SIG field of an A-PPDU header.

[0175] As another example of the present disclosure, the UHR-SIG field of the A-PPDU header may include a user field corresponding to an identifier (ID) of the first STA. And, the first information may be received from the second STA through the user field corresponding to the ID of the first STA.

[0176] That is, by setting the STA's ID to a specific value in the user field mapped to the RU / MRU to which the LS data is to be sent (i.e., a specific value corresponding to the first STA), the frequency resource unit to which the LS data is to be sent can be indicated to the first STA as the corresponding RU / MRU.

[0177] As an example of the present disclosure, the U-SIG field of the A-PPDU header may include at least one of the following: puncturing information of at least one resource unit for LS data transmission, an A-PPDU flag field indicating the transmission of the A-PPDU, an A-PPDU structure field indicating the structure of the A-PPDU, or a field indicating the bandwidth of at least one sub-PPDU included in the A-PPDU.

[0178] And, second information may be received from the second STA via the LS traffic transmission timing subfield indicating a timing at which LS data transmission is possible.

[0179] The first STA may receive an A-PPDU from the second STA based on the A-PPDU header (S1220). That is, the first STA may receive an A-PPDU from the second STA based on information included in the A-PPDU header.

[0180] Here, the A-PPDU may include multiple sub-PPDUs. Based on the arrival of LS data when a specific sub-PPDU corresponding to a specific bandwidth among the multiple sub-PPDUs is received, the reception of the specific sub-PPDU may be stopped. Then, the first STA may receive the LS data through the specific bandwidth based on the first information and the second information.

[0181] exist Fig.12 The method performed by the first STA described in the example of Figure 1 The first device (100) is executed. For example, Figure 1 One or more processors (102) of the first device (100) may receive an A-PPDU header from a second STA through one or more transceivers (106). The one or more processors (102) may be configured to receive an A-PPDU from the second STA through one or more transceivers (106) based on the A-PPDU header.

[0182] In addition, one or more memories (104) of the first device (100) may store instructions for executing when executed by one or more processors (102). Fig.12 Instructions for the methods described in the examples.

[0183] Fig.13 is a flowchart illustrating a method for a second STA to transmit and receive a PPDU according to one embodiment of the present disclosure.

[0184] The second STA may transmit an A-PPDU header including information related to A-PPDU transmission to the first STA ( S1310 ).

[0185] Already referenced Fig.12 The structure of the A-PPDU header and the information included in the A-PPDU header are described, and thus any repeated description will be omitted.

[0186] The second STA may transmit an A-PPDU to the first STA based on the A-PPDU header ( S1320 ).

[0187] For example, if LS traffic is generated / arrives when sending A-PPDU, the second STA can send LS traffic to the first STA based on at least one of first information related to at least one frequency resource unit for LS data transmission and second information related to timing for LS data transmission.

[0188] exist Fig.13 The method performed by the second STA described in the example of Figure 1 The second device (200) is executed. For example, Fig.13 One or more processors (202) of the second device (200) may be configured to send an A-PPDU header to the first STA via one or more transceivers (206). One or more processors (202) of the second device (200) may be configured to send an A-PPDU based on the A-PPDU header to the first STA via one or more transceivers (206).

[0189] In addition, the one or more memories (204) of the second device (200) may store instructions for executing when executed by the one or more processors (202). Fig.13 Instructions for the methods described in the examples.

[0190] In the following, the structure of the A-PPDU header and the related process for implementing intercepted A-PPDU transmission are described in detail.

[0191] Implementation Method 1

[0192] The A-PPDU header can be used to indicate the channel and / or timing for LS service transmission when sending the A-PPDU. That is, the A-PPDU header can be sent before sending the A-PPDU, and the A-PPDU header may include information related to the channel and / or timing for LS service transmission.

[0193] Additionally or alternatively, the A-PPDU header may include at least one of the following: information indicating the transmission of the A-PPDU, the structure of the A-PPDU, an indication of the bandwidth associated with the A-PPDU transmission, information for allocating a specific channel to each STA, or information indicating a specific channel / timing to be used for LS service transmission.

[0194] For example, if SST is applied in advance, the A-PPDU header may not include information for allocating a specific channel to each STA.

[0195] Therefore, when receiving the A-PPDU header, the STA can check the information related to the transmission of the A-PPDU and the channel / timing to be used for LS traffic transmission.

[0196] As an example of the present disclosure, Fig.14 As shown, after sending the A-PPDU header, the A-PPDU can be sent based on the A-PPDU header. The A-PPDU can send a sub-PPDU corresponding to each bandwidth. For example, when LS traffic arrives, the transmission of sub-PPDU-3 can be stopped, and the LS traffic can be sent based on the information included in the A-PPDU header.

[0197] Implementation Method 2

[0198] (DL) The A-PPDU header may include an L-STF field, an L-LTF field, an L-SIG field, an RL-SIG field, a U-SIG field, and a UHR-SIG field. That is, the A-PPDU header may be configured similarly to the preamble structure used in the UHR PPDU. However, the A-PPDU header may include content different from that included in the preamble of the UHR PPDU.

[0199] For example, the A-PPDU header may be constructed using the entire bandwidth over which the A-PPDU is to be sent.

[0200] In addition, a phase rotation may be applied to the A-PPDU header to reduce the peak-to-average power ratio (PAPR). For example, the same phase rotation as before (e.g., 80 MHz phase rotation) may be applied to bandwidths up to 320 MHz. For bandwidths of 480 MHz or 640 MHz, an 80 MHz phase rotation may be repeatedly applied, and an additional phase rotation may be applied every 80 MHz.

[0201] The L-STF field and / or the L-LTF field included in the A-PPDU header may be repeated every 20 MHz.

[0202] The L-SIG field and / or the RL-SIG field included in the A-PPDU header may be configured identically to the L-SIG field and / or the RL-SIG field included in the EHT PPDU.

[0203] For example, the LENGTH field included in the L-SIG field and / or the RL-SIG field may be set by considering the length of the entire A-PPDU. That is, the LENGTH field included in the L-SIG field and / or the RL-SIG field may be set / generated by considering the length of the longest sub-PPDU from the A-PPDU header.

[0204] For another example, considering the decoding problem after the A-PPDU header, the LENGTH field included in the L-SIG field and / or the RL-SIG field can be set only considering the A-PPDU header length. In this case, since only the length of the UHR-SIG in the A-PPDU header is indicated by the LEGNTH field, the A-PPDU transmission can be implicitly indicated by the A-PPDU header.

[0205] In addition, the value of reserved bit 4 may be set to 1, which may indicate A-PPDU transmission. That is, A-PPDU transmission may be indicated by the L-SIG field and / or the RL-SIG field.

[0206] As an example of the present disclosure, an independent field of the U-SIG field (ie, a version independent field) may include at least one of a PHY version identifier, a bandwidth field, a UL / DL field, a BSS color field, a TXOP field, an ignore field, or a valid field.

[0207] For example, the PHY version identifier field may indicate UHR. The bandwidth field may indicate the total bandwidth used for A-PPDU transmission. The UL / DL field may indicate DL. The BSS color may indicate the BSS identifier. The TXOP field may indicate the TXOP length.

[0208] For example, the A-PPDU flag field may be defined to indicate A-PPDU transmission using 1 bit of the ignore field or the valid field. That is, the STA may determine whether to send an A-PPDU through the A-PPDU flag field. For example, the A-PPDU flag field may indicate whether the PPDU sent after the A-PPDU header is an A-PPDU.

[0209] For another example, the A-PPDU structure field may be defined using 1 bit of the ignore field or the valid field. The A-PPDU structure field may indicate the A-PPDU structure (eg, the composition of the sub-PPDU).

[0210] For another example, a sub-PPDU bandwidth field may be defined, which indicates the bandwidth of each sub-PPDU by using 1 bit of an ignored field or a valid field. The sub-PPDU bandwidth field may consist of multiple fields based on the number and type of sub-PPDUs indicated in the A-PPDU structure field.

[0211] For another example, the bandwidth of the sub-PPDU may be predetermined according to the A-PPDU structure and bandwidth. In this case, the sub-PPDU bandwidth field may not be included in the U-SIG field.

[0212] As an example of the present disclosure, a dependent field of the U-SIG field (ie, a version dependent field) may include a sub-PPDU bandwidth field and an A-PPDU structure field defined in independent fields of the U-SIG field.

[0213] For another example, the subordinate fields of the U-SIG field may include a delay-sensitive service TX channel field for intercepted PPDU transmission. The delay-sensitive service TX channel field may indicate a channel to be used for LS service and / or intercepted PPDU transmission.

[0214] The Delay Sensitive Service Transport Channel field may be configured in a bitmap format.

[0215] For example, considering the entire bandwidth of the A-PPDU, the delay-sensitive service transmission channel field may include a bitmap corresponding to each 20 MHz channel. That is, the bit corresponding to the channel on which the LS service is sent in the bitmap may be set to 1 (or 0).

[0216] For another example, the Delay Sensitive Service Transmission Channel field may include a bitmap corresponding to each 20 MHz channel within the channel on which the UHR PPDU is sent. That is, the bit in the bitmap corresponding to the channel on which the LS service is sent may be set to 1 (or 0).

[0217] For example, it is assumed that the transmission of a specific sub-PPDU can be ended early because the specific sub-PPDU is a short packet. Here, the amount of data corresponding to the specific STA may be small compared to the length of the A-PPDU, so the data sent to the specific STA can be defined as a short packet.

[0218] For another example, if the length of a specific sub-PPDU is less than a threshold, the specific sub-PPDU may be defined as a short packet. In this case, the channel to be used to send the LS service may be indicated by the Delay Sensitive Service Transmission Channel field.

[0219] Additionally or alternatively, the subordinate fields of the U-SIG field may include a Delay Sensitive Service Tx Timing subfield. The Delay Sensitive Service Tx Timing subfield may indicate the timing at which delay sensitive service may be transmitted, and the Delay Sensitive Service Tx Channel field may indicate / allocate a channel used only for LS service transmission.

[0220] Here, when transmitting the DL A-PPDU, if there is no delay-sensitive traffic, a dummy signal may be transmitted on the channel only for LS traffic transmission indicated by the Delay-Sensitive Traffic Tx Channel field.

[0221] As an example of the present disclosure, in a case where a specific STA transmits periodic LS traffic and the STA is assigned to a specific channel by the SST, the specific channel may be indicated as being used only for LS traffic transmission via the Delay Sensitive Traffic Tx Channel field.

[0222] As another example of the present disclosure, puncturing information of the A-PPDU may be indicated by a puncturing channel information field, etc. The puncturing information may also be applied to the A-PPDU header.

[0223] Similar to the EHT-SIG field, the UHR-SIG field may include a common field and a user field.

[0224] For example, the common field may indicate the RU allocation for each 20MHz channel through the RU allocation field. However, since the information included in the EHT-SIG field may be sent through the UHR-SIG in the A-PPDU, etc., such information may not be included in the UHR-SIG field of the A-PPDU header.

[0225] And, the corresponding RU / MRU may be allocated to a specific STA by using the STA ID mapped in the user field of each RU / MRU. The STA may perform channel switching in advance and wait by using the RU / MRU mapping information included in the user field.

[0226] For example, in the case where a specific channel has been allocated to each STA through SST, etc., when transmitting A-PPDU, RU allocation information may be indicated to the STA through the SIG field. Therefore, the A-PPDU header may not have a user field and a RU allocation field.

[0227] In addition, by setting the STA ID to a specific value in the user field mapped to the RU / MRU to which the LS traffic is to be transmitted, the STA can be indicated to the RU / MRU to which the LS traffic is to be transmitted.

[0228] Here, RU / MRU may be applied only to LS services. The situation where a specific STA is assigned to RU / MRU and performs a transmission operation and sends an intercepted PPDU, or the situation where a short packet sub-PPDU is sent after a specific timing and LS services are sent may not be considered. Other information for A-PPDU transmission may be sent through the SIG field in the A-PPDU.

[0229] As another example of the present disclosure, since the SST allocates a specific channel to the STA and a specific RU / MRU can be allocated in the SIG of the A-PPDU, the A-PPDU header may include an L-STF field, an L-LTF field, an L-SIG field, an RL-SIG field, and a U-SIG field (i.e., only exists until the U-SIG field). By indicating the channel and timing information for LS service transmission in the U-SIG of the A-PPDU header, the overhead can be effectively managed.

[0230] 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 considered 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 combined partial 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.

[0231] 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.

[0232] 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 including such a storage medium. The storage medium may include a high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid-state storage devices, but is not limited thereto, and it may include a non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory optionally includes one or more storage devices located 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.

[0233] Industrial Applicability

[0234] 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 an aggregate physical layer protocol data unit A-PPDU header from a second STA; as well as receiving an A-PPDU from the second STA based on the A-PPDU header, The A-PPDU header includes first information related to at least one frequency resource unit used for delay-sensitive LS data transmission and second information related to timing used for the LS data transmission.

2. The method according to claim 1, wherein: The first information is received from the second STA through a universal U-SIG field or an ultra high reliability UHR field of the A-PPDU header.

3. The method according to claim 2, wherein: Based on allocating a specific channel through information related to subchannel selective transmission, the specific channel is indicated as a channel for transmitting the LS data through the first information included in the U-SIG field of the A-PPDU header.

4. The method according to claim 2, wherein: The U-SIG field of the A-PPDU header includes at least one of the following: an A-PPDU flag field indicating transmission of the A-PPDU, an A-PPDU structure field indicating a structure of the A-PPDU, or a field indicating a bandwidth of at least one sub-PPDU included in the A-PPDU.

5. The method according to claim 1, wherein: Based on the absence of the LS data, a dummy signal is transmitted through a specific channel indicated by the first information.

6. The method according to claim 1, wherein: The second information is received from the second STA through an LS traffic transmission timing subfield indicating a timing at which the LS data transmission is possible.

7. The method according to claim 2, wherein: The U-SIG field of the A-PPDU header includes puncturing information of at least one frequency resource unit used for the LS data transmission.

8. The method according to claim 2, wherein: The UHR-SIG field includes a user field corresponding to an identifier ID of the first STA, and The first information is received from the second STA through the user field.

9. The method according to claim 1, wherein: The A-PPDU includes a plurality of sub-PPDUs, and Based on the LS data arriving when a specific sub-PPDU corresponding to a specific bandwidth among the plurality of sub-PPDUs is received, reception of the specific sub-PPDU is stopped, and the LS data is received through the specific bandwidth based on the first information and the second information.

10. A first station STA operating in a wireless local area network (WLAN) system, the first STA comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: receiving, by the at least one transceiver, an aggregate physical layer protocol data unit (A-PPDU) header from a second STA; and receiving, by the at least one transceiver, an A-PPDU from the second STA based on the A-PPDU header, The A-PPDU header includes first information related to at least one frequency resource unit used for delay-sensitive LS data transmission and second information related to timing used for the LS data transmission.

11. A method performed by a second station (STA) in a wireless LAN system, the method comprising the following steps: Sending an aggregate physical layer protocol data unit A-PPDU header from the first STA; as well as Sending an A-PPDU to the first STA based on the A-PPDU header, The A-PPDU header includes first information related to at least one frequency resource unit used for delay-sensitive LS data transmission and second information related to timing used for the LS data transmission.

12. A second station STA operating in a wireless LAN system, the second STA comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: sending, by the at least one transceiver, an aggregate physical layer protocol data unit A-PPDU header from the first STA; and sending, by the at least one transceiver, an A-PPDU to the first STA based on the A-PPDU header, The A-PPDU header includes first information related to at least one frequency resource unit used for delay-sensitive LS data transmission and second information related to timing used for the LS data transmission.

13. A processing device, the processing device being configured to control a first station STA in a wireless LAN system, the processing device comprising: at least one processor; as well as at least one computer memory operatively connected to the at least one processor and storing instructions that upon execution by the at least one processor perform operations comprising: receiving an aggregate physical layer protocol data unit A-PPDU header from a second STA; and receiving an A-PPDU from the second STA based on the A-PPDU header, The A-PPDU header includes first information related to at least one frequency resource unit used for delay-sensitive LS data transmission and second information related to timing used for the LS data transmission.

14. At least one non-transitory computer-readable medium storing at least one instruction, in, The at least one instruction executable by at least one processor controls a device in a wireless LAN system to: receiving an aggregate physical layer protocol data unit A-PPDU header from a second STA; as well as receiving an A-PPDU from the second STA based on the A-PPDU header, The A-PPDU header includes first information related to at least one frequency resource unit used for delay-sensitive LS data transmission and second information related to timing used for the LS data transmission.

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