Method and apparatus for performing multi-layer-based transmission or reception in wireless LAN system

Abstract

Disclosed are a method and an apparatus operating in a wireless LAN system. A method performed by a first STA in a wireless LAN system according to an embodiment of the present disclosure may comprise the steps of: receiving a first physical protocol data unit (PPDU) including a user field of an ultra high reliability (UHR)-signal (SIG) field from a second STA; and decoding, on the basis of the user field, a first physical layer service unit (physical service data unit (PSDU)) allocated to a first resource unit (RU) among the plurality of resource units (MRU) and a second PSDU allocated to a second RU among the MRUs, wherein the user field includes i) first information indicating whether the multi-layer transmission is applied to the first PPDU, and ii) second information related to each of the first PSDU and the second PSDU.

Description

Technical Field

[0001] The present disclosure relates to communication operations in a wireless local area network (WLAN) system, and more particularly, to methods and apparatuses for performing multi-layer transmission and reception. Background Art

[0002] New technologies have been introduced for wireless LAN (WLAN) to improve transmission rate, 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 can be referred to as Wi-Fi. For example, technologies recently introduced to WLAN include enhancements to the very high throughput (VHT) of the 802.11ac standard and enhancements to the high efficiency (HE) of the IEEE 802.11ax standard.

[0003] To provide a more complete wireless communication environment, enhancement technologies for EHT (extremely high throughput) are being discussed. For example, technologies for multi-access point (AP) coordination and multiple-input multiple-output (MIMO) that support increased bandwidth, efficient use of multiple bands, and increased spatial streams are being studied, and in particular, various technologies for supporting low-latency or real-time services are being studied. In addition, new technologies for supporting ultra-high reliability (UHR) by including improvements or extensions to EHT technologies are being discussed. Summary of the Invention

[0004] Technical Problem

[0005] A technical problem of the present invention is to provide a method and an apparatus for performing multi-layer based transmission and reception in a wireless LAN system.

[0006] A technical problem of the present disclosure is to provide a method and an apparatus for operating according to a restriction rule in a state of allocating a RU (resource unit) / MRU (multi-resource unit) for multi-layer transmission.

[0007] A technical problem of the present invention is to provide a method and an apparatus for performing multi-layer based relay transmission.

[0008] Technical objectives achieved by the present disclosure are not limited to the above technical objectives, and those skilled in the relevant art will clearly understand other technical objectives not described herein from the following description.

[0009] Technical Solution

[0010] According to an embodiment of the present disclosure, a method performed by a first station (STA) in a wireless LAN system may include: receiving, from a second STA, a first physical protocol data unit (PPDU) including a user field having an ultra-high reliability (UHR)-signal (SIG) field; and decoding a first physical layer service unit (PSDU) assigned to a first resource unit (RU) among a plurality of resource units (MRUs) and a second PSDU assigned to a second RU among the MRUs based on the user field, and the user field may include: i) first information indicating whether multi-layer transmission is applied to the first PPDU, and ii) second information associated with each of the first PSDU and the second PSDU.

[0011] According to an embodiment of the present disclosure, a method performed by a second station (STA) in a wireless LAN system may include: generating a first physical protocol data unit (PPDU) including a user field having an ultra-high reliability (UHR)-signal (SIG) field; and transmitting the first PPDU to a first STA, and a first resource unit (RU) among a plurality of resource units (MRUs) may be assigned to a first physical layer service unit (PSDU), and a second RU among the MRUs is assigned to a second PSDU, and the user field may include: i) first information indicating whether multi-layer transmission is applied to the first PPDU, and ii) second information associated with each of the first PSDU and the second PSDU.

[0012] Technical effects

[0013] According to various embodiments of the present disclosure, a method and an apparatus for performing multi-layer based transmission and reception in a wireless LAN system may be provided.

[0014] According to various embodiments of the present disclosure, a method and an apparatus for operating according to a restriction rule in a state of allocating RUs / MRUs for multi-layer transmission may be provided.

[0015] According to various embodiments of the present disclosure, a method and an apparatus for performing multi-layer based relay transmission may be provided.

[0016] The effects that can be achieved by the present disclosure are not limited to the above effects, and other effects not described herein can be clearly understood by those skilled in the art from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings included as part of the detailed description for understanding the present disclosure provide embodiments of the present disclosure and describe the technical features of the present disclosure through the detailed description.

[0018] Figure 1 FIG. Schematic block diagram of a wireless communication device according to an embodiment of the present disclosure.

[0019] Figure 2 is a diagram illustrating an exemplary structure of a WLAN system to which the present disclosure can be applied.

[0020] Figure 3 is a diagram for describing a link setup process to which the present disclosure can be applied.

[0021] Figure 4 is a diagram for describing a backoff process to which the present disclosure can be applied.

[0022] Figure 5 is a diagram for describing a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0023] Figure 6 is a diagram for describing an example of a frame structure used in a WLAN system to which the present disclosure can be applied.

[0024] 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.

[0025] Figure 8 shows an exemplary format of a trigger frame to which the present disclosure can be applied.

[0026] Figure 9 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] Figure 10 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. Detailed Description of the Invention

[0028] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed through the drawings is to describe exemplary embodiments of the present disclosure, and does not represent the only embodiments 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.

[0029] In some cases, 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 to prevent ambiguity in the concept of the present disclosure.

[0030] In the present disclosure, when an element is referred to as being "connected", "combined", or "linked" to another element, it may include both an indirect connection relationship and a direct connection relationship in which yet another element exists therebetween. Further, in the present disclosure, the terms "comprising" or "having" specify the presence of the recited features, steps, operations, components, and / or elements, but do not preclude the presence or addition of one or more other features, stages, operations, components, elements, and / or groups thereof.

[0031] In the present invention, terms such as "first", "second", etc. are only used to distinguish one element from another and do not limit the element, unless otherwise specified, and do not limit the order or importance, etc. between the elements. Thus, 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.

[0032] The terms used in the present disclosure are for the purpose of describing specific embodiments and are not intended to limit the claims. As used in the description of the embodiments and the appended claims, the singular forms are intended to include the plural forms unless the context clearly indicates otherwise. The term "and / or" as used in the present disclosure may refer to one of the related listed items or mean that it refers to and includes any and all possible combinations of two or more of them. Further, unless otherwise specified, " / " between words in the present disclosure has the same meaning as "and / or".

[0033] Examples of the present disclosure can be applied to various wireless communication systems. For example, examples of the present disclosure can be applied to a wireless LAN system. For example, examples of the present disclosure can be applied to a wireless LAN based on the IEEE 802.11a / g / n / ac / ax standards. Further, examples of the present disclosure can be applied to a wireless LAN based on the newly proposed IEEE 802.11be (or EHT) standard. Examples of the present disclosure can be applied to a wireless LAN based on the IEEE 802.11be version-2 standard corresponding to additional enhancement technologies of the IEEE 802.11be version-1 standard. Additionally, examples of the present disclosure can be applied to a next-generation standard-based wireless LAN after IEEE802.11be. Further, examples of the present disclosure can be applied to a cellular wireless communication system. For example, it can be applied to a cellular wireless communication system based on technologies such as Long Term Evolution (LTE) and 5G New Radio (NR) based on the Third Generation Partnership Project (3GPP) standards.

[0034] Hereinafter, the technical features to which examples of the present disclosure can be applied will be described.

[0035] Figure 1 A block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0036] Figure 1 The first device 100 and the second device 200 illustrated in the figure can be replaced by various terms, such as a terminal, a wireless device, a wireless transmit / receive unit (WTRU), a user equipment (UE), a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a mobile subscriber unit (MSU), a subscriber station (SS), an advanced mobile station (AMS), a wireless terminal (WT), or simply a user, etc. Additionally, the first device 100 and the second device 200 can include an access point (AP), a base station (BS), a fixed station, a Node B, a base transceiver system (BTS), a network. It can be replaced by various terms such as an artificial intelligence (AI) system, a roadside unit (RSU), a repeater, a router, a repeater, and a gateway, etc.

[0037] Figure 1 The devices 100 and 200 illustrated in the figure can be referred to as a station (STA). For example, Figure 1 The devices 100 and 200 illustrated in the figure can be referred to by various terms such as a transmitting device, a receiving device, a transmitting STA, and a receiving STA. For example, STAs 110 and 200 can perform an access point (AP) role or a non-AP role. That is, in the present disclosure, STAs 110 and 200 can perform AP and / or non-AP functions. When STAs 110 and 200 perform the AP function, they can be simply referred to as APs, and when STAs 110 and 200 perform the non-AP function, they can be simply referred to as STAs. Additionally, in the present disclosure, an AP can also be indicated as an APSTA.

[0038] Refer to Figure 1 , the first device 100 and the second device 200 can send and receive radio signals through various wireless LAN technologies (e.g., the IEEE 802.11 series). The first device 100 and the second device 200 can include interfaces for a media access control (MAC) layer and a physical layer (PHY) compliant with the IEEE 802.11 standard.

[0039] Furthermore, the first device 100 and the second device 200 can additionally support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, etc.) technologies in addition to wireless LAN technologies. Additionally, the devices of the present disclosure can be implemented in various devices, such as a mobile phone, a vehicle, a personal computer, an augmented reality (AR) device, a virtual reality (VR) device, etc. Additionally, the STAs in this specification can support various communication services, such as voice calls, video calls, data communication, autonomous driving, machine type communication (MTC), machine-to-machine (M2M), device-to-device (D2D), IoT (Internet of Things), etc.

[0040] The first device 100 may include one or more processors 102 and one or more memories 104, and may additionally include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memory 104 and / or the transceiver 106 and may be configured to implement the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in the present disclosure. For example, after generating first information / signal by processing the information in the memory 104, the processor 102 may transmit a wireless signal including the first information / signal through the transceiver 106. Additionally, the processor 102 may receive a wireless signal including second information / signal through the transceiver 106, and then store the information obtained by signal processing of the second information / signal in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software code that includes instructions for performing all or part of the processes controlled by the processor 102 or for performing the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed 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 technologies (e.g., LTE 802.11 series). The transceiver 106 may be connected to the processor 102 and may transmit 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 with an RF (radio frequency) unit. In the present disclosure, a device may mean a communication modem / circuit / chip.

[0041] The second device 200 may include one or more processors 202 and one or more memories 204, and may additionally include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memory 204 and / or the transceiver 206 and may be configured to implement the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this 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 / signals through the transceiver 206. Additionally, the processor 202 may receive a wireless signal including fourth information / signals through the transceiver 206, and then store the information obtained by signal processing of the fourth information / signals in the memory 204. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may store software code that includes instructions for executing all or part of the processes controlled by the processor 202 or for executing the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this 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., the 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 with an RF unit. In this disclosure, a device may refer to a communication modem / circuit / chip.

[0042] In the following, the hardware components of devices 100 and 200 will be described in more detail. Without being limited thereto, one or more protocol layers may be implemented by one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as PHY and MAC). One or more processors 102 and 202 may generate one or more PDUs (Protocol Data Units) and / or one or more SDUs (Service Data Units) according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this disclosure. One or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this disclosure. One or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this disclosure to provide them to one or more transceivers 106 and 206. One or more processors 102 and 202 may receive signals (e.g., baseband signals) from one or more transceivers 106 and 206 and obtain PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in this disclosure.

[0043] One or more processors 102 and 202 may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. In an 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 and 202. The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts included in this disclosure may be implemented by using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The firmware or software configured to execute the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts included in this disclosure may be included in one or more processors 102 and 202 or may be stored in one or more memories 104 and 204 and driven by one or more processors 102 and 202. The descriptions, functions, procedures, proposals, methods, and / or operation flowcharts included in this invention may be implemented by firmware or software in the form of code, commands, and / or command sets.

[0044] One or more memories 104, 204 may be connected to one or more processors 102, 202 and are capable of storing data, signals, messages, information, programs, code, instructions, and / or commands in various forms. One or more memories 104, 204 may be configured with ROM, RAM, EPROM, flash memory, hard disk drives, registers, cache memories, 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 through various techniques such as wired or wireless connections.

[0045] One or more transceivers 106, 206 may send user data, control information, wireless signals / channels, etc. mentioned in the methods and / or operation flowcharts, etc. of the present disclosure to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, processes, proposals, methods, and / or operation flowcharts, etc. included in the present disclosure from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and may 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 descriptions, functions, processes, proposals, methods, and / or operation flowcharts, etc. included in the present disclosure through one or more antennas 108, 208. In the present invention, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106, 206 may convert the received wireless signals / channels, etc. from RF-band signals to baseband signals by using one or more processors 102, 202 to process the received user data, control information, wireless signals / channels, etc. One or more transceivers 106, 206 may convert the user data, control information, wireless signals / channels, etc. processed by using one or more processors 102, 202 from baseband signals to RF-band signals. Therefore, one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

[0046] For example, one of STAs 100 and 200 can perform the expected operations of an AP, and the other of STAs 100 and 200 can perform the expected operations of a non-AP STA. For example, Figure 1 the transceivers 106 and 206 can 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). Additionally, in the present disclosure, operations in which various STAs generate transmission / reception signals or perform data processing or calculations on transmission / reception signals in advance can be performed by Figure 1 the processors 102 and 202. For example, examples of operations of generating transmission / reception signals or performing data processing or calculations on transmission / reception signals in advance can 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 a PPDU, 2) determining / configuring / obtaining time resources or frequency resources (e.g., subcarrier resources) for fields (SIG, STF, LTF, data, etc.) included in a 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 PPDU actions, 4) power control operations and / or power saving operations applied to an STA, 5) operations related to determining / obtaining / configuring / calculating / decoding / encoding, etc., of an ACK signal. Additionally, in the following examples, various information (e.g., information related to fields / sub-fields / control fields / parameters / power, etc.) used by various STAs to determine / obtain / configure / calculate / decode / encode transmission and reception signals can be stored in Figure 1 the memories 104 and 204.

[0047] Hereinafter, a downlink (DL) can mean a link for communication from an AP STA to a non-AP STA, and DL PPDUs / packets / signals can be transmitted and received through the DL. In DL communication, the transmitter can be part of the AP STA, and the receiver can be part of the non-AP STA. An uplink (UL) can mean a link for communication from a non-AP STA to an AP STA, and UL PPDUs / packets / signals can be transmitted and received through the UL. In UL communication, the transmitter can be part of the non-AP STA, and the receiver can be part of the AP STA.

[0048] Figure 2 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0049] The structure of a wireless LAN system can consist of multiple components. A wireless LAN that supports STA mobility transparent to the upper layer can be provided through the interaction of multiple components. A basic service set (BSS) corresponds to the basic building block of a wireless LAN. Figure 2 Exemplarily, it is shown that there are two BSSs (BSS1 and BSS2) and two STAs are included as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). Figure 2 The ellipse representing the BSS in can also be understood as representing the coverage area where the STAs included in the corresponding BSS maintain communication. This area can be called the basic service area (BSA). When an STA moves out of the BSA, it cannot directly communicate with other STAs within the BSA.

[0050] If the DS shown in Figure 2 is not considered, the most basic type of BSS in a wireless LAN is an independent BSS (IBSS). For example, an IBSS can have a minimum form that only contains two STAs. For example, assuming other components are omitted, BSS1 that only contains STA1 and STA2 or BSS2 that only contains STA3 and STA4 can respectively correspond to representative examples of an IBSS. This configuration is possible when STAs can directly communicate without an AP. Additionally, in this type of wireless LAN, it is not pre-configured but can be configured when a LAN is needed, and this can be called an ad-hoc network. Since an IBSS does not include an AP, there is no centralized management entity. That is, in an IBSS, STAs are managed in a distributed manner. In an IBSS, all STAs can consist of mobile STAs and access to the distributed system (DS) is not allowed, thus forming a self-contained network.

[0051] An STA's membership in a BSS can be dynamically changed by turning the STA on or off, entering or exiting the BSS area, etc. To become a member of a BSS, an STA can use a synchronization process to join the BSS. To access all services of the BSS infrastructure, the STA should be associated with the BSS. This association can be dynamically established and can include the use of distributed system services (DSS).

[0052] 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 a greater distance may be required. A distributed system (DS) can be configured to support extended coverage.

[0053] DS means the structure in which BSSs are interconnected. Specifically, as shown in Figure 2As shown, the BSS can exist as an extended form of a network consisting of multiple BSSs. The DS is a logical concept and can be specified by the characteristics of the distributed system medium (DSM). In this regard, the wireless medium (WM) and the DSM can be logically separated. Each logical medium is used for a different purpose and is used by different components. These media are not limited to being the same or different. Thus, the flexibility of the wireless LAN structure (DS structure or other network structures) can be explained by the logical difference of multiple media. 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 embodiment.

[0054] The DS can support mobile devices by providing seamless integration of multiple BSSs and providing the logical services necessary to address addresses to destinations. Additionally, the DS can further include a component called a portal, which serves as a bridge for the connection between the wireless LAN and other networks (e.g., IEEE 802.X).

[0055] The AP enables access to the DS via the WM for the associated non-AP STA and refers to an entity that also has the functionality of the STA. Data movement between the BSS and the DS can be performed by the AP. For example, Figure 2 the STAs shown in [figure] have the functionality of the STA and provide the function of allowing the associated non-AP STAs (STA1 and STA4) to access the DS. Additionally, since all APs basically correspond to STAs, all APs are addressable entities. The address used by the AP for communication on the WM and the address used by the AP for communication on the DSM are not necessarily the same. The BSS composed of an AP and one or more STAs can be called an infrastructure BSS.

[0056] Data sent from the STA address of one of the STAs associated with the AP to the corresponding AP can always be received on an uncontrolled port and can be processed by the IEEE 802.1X port access entity. Additionally, when the controlled port is authenticated, the transmitted data (or frame) can be delivered to the DS.

[0057] In addition to the above structure of the DS, an extended service set (ESS) can also be configured to provide a wide coverage area.

[0058] An ESS means a network in which a network of any size and complexity is composed of a DS and BSSs. An ESS can correspond to a set of BSSs connected to a DS. However, an ESS does not include the DS. An ESS network is characterized as an IBSS in the logical link control (LLC) layer. STAs included in an ESS can communicate with each other, and a mobile STA can move from one BSS to another BSS (within the same ESS) that is transparent to the LLC. APs included in an ESS can have the same service set identifier (SSID). The SSID is distinguished from the BSSID, which is the identifier of the BSS.

[0059] The wireless LAN system does not assume anything about the relative physical positions of the BSSs, and all of the following forms are possible. BSSs can partially overlap, which is a form commonly used to provide continuous coverage. Additionally, BSSs may not be physically connected, and logically, there is no limit to the distance between BSSs. Additionally, BSSs may be physically located in the same position, which can be used to provide redundancy. Additionally, one (or more) IBSS or ESS networks can physically exist in the same space as one (or more than one) ESS network. This can be similar to the form corresponding to an ESS network when an ad-hoc network operates in the location where an ESS network exists, when physically overlapping wireless networks are configured by different organizations, or when two or more different access and security policies are required in the same location.

[0060] Figure 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

[0061] In order for an STA to establish a link to a network and send / receive data, it first discovers the network, performs authentication, establishes an association, and an authentication process for security needs to be performed. The link setup process can also be referred to as a session initiation process or a session setup process. Additionally, the processes of discovery, authentication, association, and security setup in the link setup process can be collectively referred to as an association process.

[0062] In step S310, the STA can perform a network discovery operation. The network discovery operation can include a scanning operation of the STA. That is, in order for the STA to access the network, it needs to find a network that it can participate in. Before participating in a wireless network, the STA should identify a compatible network, and the process of identifying the networks existing in a specific area is called scanning.

[0063] Scanning schemes include active scanning and passive scanning. Figure 3Exemplary diagrams illustrate network discovery operations including an active scanning process. In active scanning, the STA performing the scan sends a probe request frame while moving through channels to discover which APs exist in its vicinity and waits for a response thereto. The responder sends a probe response frame to the STA that has sent the probe request frame as a response to the probe request frame. Here, the responder can be the STA that last sent a beacon frame in the BSS of the scanned channel. In a BSS, since the AP sends beacon frames, the AP becomes the responder, and in an IBSS, the STAs in the IBSS take turns sending beacon frames, so the responder is not constant. For example, the STA that sends a probe request frame on channel 1 and receives a probe response frame on channel 1 can store the BSS-related information included in the received probe response frame and can move to the next channel (e.g., channel 2) and perform the scan in the same way (i.e., send / receive probe request / response on channel 2).

[0064] Although Figure 3 not shown, the scanning operation can be performed in a passive scanning manner. In passive scanning, the STA performing the scan waits for beacon frames while moving through channels. A beacon frame is one of the management frames defined in IEEE 802.11 and is sent periodically 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 a BSS, the AP is used to send beacon frames periodically, and in an IBSS, the STAs within the IBSS take turns sending beacon frames. When the STA performing the scan receives a beacon frame, the STA stores the information for the BSS included in the beacon frame and records the beacon frame information in each channel while moving to another channel. The STA that receives the beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform the scan in the next channel in the same way. Comparing active scanning and passive scanning, active scanning has the advantages of lower latency and lower power consumption than passive scanning.

[0065] After the STA discovers the network, an authentication process can be performed in step S320. To clearly distinguish this authentication process from the security establishment operation in step S340 to be described later, this authentication process can be referred to as the first authentication process.

[0066] The authentication process includes a process in which 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 frames for authentication request / response correspond to management frames.

[0067] The authentication frame includes an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a Robust Security Network (RSN), and a finite cyclic group, etc. This corresponds to some examples of the information that can be included in the authentication request / response frame, and can be replaced with other information or can further include additional information.

[0068] The STA can send an authentication request frame to the AP. The AP can determine whether to permit the authentication of the corresponding STA based on the information included in the received authentication request frame. The AP can provide the result of the authentication process to the STA via an authentication response frame.

[0069] After the STA is successfully authenticated, the association process can be performed in step S330. The association process includes a process in which the STA sends an association request frame to the AP and, in response, the AP sends an association response frame to the STA.

[0070] For example, the association request frame can include information related to various capabilities, beacon listening intervals, service set identifiers (SSIDs), supported rates, supported channels, RSNs, mobility domains, supported operation classes, traffic indication map broadcast requests (TIM broadcast requests), interworking service capabilities, etc. For example, the association response frame can include information related to various capabilities, status codes, association IDs (AIDs), supported rates, enhanced distributed channel access (EDCA) parameter sets, received channel power indicators (RCPIs), received signal-to-noise ratio indicators (RSNIs), mobility domains, timeout intervals (e.g., association recovery times), overlapping BSS scan parameters, TIM broadcast responses, quality of service (QoS) maps, etc. This corresponds to some example information that can be included in the association request / response frames, and can be replaced with other information or can further include additional information.

[0071] After the STA is successfully associated with the network, a security setup process can be performed in step S340. The security setup process in step S340 can be referred to as an authentication process via a robust security network association (RSNA) request / response, and the authentication process in step S320 is referred to as the first authentication process, and the security setup process in step S340 can also be abbreviated as an authentication process.

[0072] The security setup process in step S340 can include, for example, a process of setting up a private key via a 4-way handshake of Extensible Authentication Protocol over LAN (EAPOL) frames. Additionally, the security setup process can be performed according to a security scheme not defined in the IEEE 802.11 standard.

[0073] Figure 4 is a diagram for explaining the backoff process to which the present disclosure can be applied.

[0074] In a wireless LAN system, the basic access mechanism of the Media Access Control (MAC) is the 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, the AP and / or STA can perform a Clear Channel Assessment (CCA) to sense the wireless channel or medium within a predetermined time interval (e.g., DCF Interframe Space (DIFS)) before starting transmission. As a result of the sensing, if it is determined that the medium is idle, frame transmission is started through the corresponding medium. On the other hand, if the medium is detected to be occupied or busy, the corresponding AP and / or STA does not start its own transmission and can set a delay period (e.g., a random backoff period) for medium access and attempt frame transmission after waiting. By applying a random backoff period, since it is expected that several STAs will attempt frame transmission after waiting for different time periods, collisions can be minimized.

[0075] In addition, the IEEE 802.11 MAC protocol provides a Hybrid Coordination Function (HCF). The HCF is based on the DCF and the Point Coordination Function (PCF). The PCF is a polling-based synchronous access method and refers to a method in which all receiving APs and / or STAs are polled periodically to receive data frames. Additionally, the HCF has Enhanced Distributed Channel Access (EDCA) and HCF Controlled Channel Access (HCCA). The EDCA is a contention-based access method for a provider to provide data frames to multiple users, and the HCCA uses a polling mechanism to use a contention-free channel access method. Additionally, the HCF includes a media access mechanism for improving the Quality of Service (QoS) of the wireless LAN and can send QoS data in both the Contention Period (CP) and the Contention-Free Period (CFP).

[0076] Reference Figure 4 , the operation based on the random backoff period will be described. When the occupied / busy medium becomes idle, several STAs may attempt to send data (or frames). As a method for minimizing collisions, each STA can separately select a random backoff count and attempt transmission after waiting for the corresponding slot time. The random backoff count has a pseudo-random integer value and can be determined as one of the values ranging from 0 to the value of CW. Here, CW is the contention window parameter value. The CW parameter is given an initial value of CWmin, but if a transmission failure occurs (e.g., when an ACK for a sent frame is not received), it can take a value twice as large. When the CW parameter value reaches CWmax, data transmission can be attempted while maintaining the CWmax value until the data transmission is successful, and when the 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, ...).

[0077] When the random backoff process starts, the STA continuously monitors the medium while counting down the backoff time slots according to the determined backoff count value. When the medium occupancy is detected, it stops the countdown and waits, and when the medium becomes idle, it resumes the remaining countdown.

[0078] In Figure 4 's example, when the packet to be transmitted arrives at the MAC of STA3, STA3 can send the frame immediately after confirming that the medium is idle for as long as the DIFS. The remaining STAs monitor and wait for the medium to be occupied / busy. Meanwhile, data to be transmitted may also occur in each of STA1, STA2, and STA5, and when the medium is detected as idle, each STA waits for as long as the DIFS, and then can perform the countdown of the backoff time slots according to the random backoff count value selected by each STA. Assume that STA2 selects the smallest backoff count value and STA1 selects the largest backoff count value. That is, the situation where the remaining backoff time of STA5 is less than the remaining backoff time of STA1 when STA2 finishes the backoff count and starts the frame transmission is illustrated. STA1 and STA5 temporarily stop the countdown and wait while STA2 occupies the medium. When STA2's occupancy ends and the medium becomes idle again, STA1 and STA5 wait for the DIFS and resume the stopped backoff count. That is, after counting down the remaining backoff time slots within the remaining backoff time, the frame transmission can start. Since the remaining backoff time of STA5 is less than that of STA1, STA5 starts the frame transmission. While STA2 occupies the medium, data to be transmitted may also occur in STA4. From the perspective of STA4, when the medium becomes idle, STA4 can wait for the DIFS, and then perform the countdown according to the random backoff count value selected by STA4 and start sending the frame. Figure 4 's example shows the situation where the remaining backoff time of STA5 exactly coincides 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 the data transmission fails. In this case, both STA4 and STA5 can double the CW value, select a random backoff count value, and perform the countdown. STA1 waits when the medium is occupied due to the transmissions of STA4 and STA5, waits for the DIFS when the medium becomes idle, and then starts the frame transmission after the remaining backoff time has elapsed.

[0079] As Figure 4As shown in the example, a data frame is a frame for transmitting data forwarded to a higher layer, and can be sent after performing backoff after DIFS elapses when the medium becomes 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 performing backoff after an IFS such as DIFS or Point Coordination Function IFS (PIFS). As subtype frames of the management frame, there are beacons, association requests / responses, re-association requests / responses, probe requests / responses, authentication requests / responses, etc. A control frame is a frame for controlling access to the medium. As subtype frames of the control frame, there are Request to Send (RTS), Clear to Send (CTS), Acknowledgment (ACK), Power Save Poll (PS-Poll), Block Ack (BlockAck), Block ACK Request (BlockACKReq), Null Data Packet Announcement (NDP Announcement), and Trigger, etc. If the control frame is not a response frame to a previous frame, it is sent after performing backoff after DIFS elapses, and if it is a response frame to a previous frame, it is sent without performing backoff after Short IFS (SIFS) elapses. The type and subtype of a frame can be identified by the type field and subtype field in the Frame Control (FC) field.

[0080] A Quality of Service (QoS) STA can perform backoff that is performed after Arbitration IFS (AIFS) of the access category (AC) to which the frame belongs, i.e., AIFS[i] (where i is a value determined by the AC), and then can send the frame. Here, the frame that can use AIFS[i] can be a data frame, a management frame, or a control frame other than a response frame.

[0081] Figure 5 is a diagram for explaining the CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0082] As described above, the CSMA / CA mechanism includes virtual carrier sensing in addition to the physical carrier sensing in which the STA directly senses the medium. Virtual carrier sensing aims to compensate for problems that may occur in media access, such as the hidden node problem. For virtual carrier sensing, the MAC of the STA can use the Network Allocation Vector (NAV). The NAV is a value that indicates to other STAs the remaining time until the medium becomes available for the current STA using it or the STA having the right to use the medium. Therefore, the value set to the NAV corresponds to the period during which the medium is scheduled to be used by the STA that sends the frame, and the STA that receives the NAV value is prohibited from accessing the medium during the corresponding period. For example, the NAV can be configured based on the value of the "Duration" field in the MAC header of the frame.

[0083] In Figure 5In the example, it is assumed that STA1 intends to send data to STA2, and STA3 is in a position where it can eavesdrop on some or all of the frames transmitted and received between STA1 and STA2.

[0084] To reduce the likelihood of collisions occurring in the frame transmission operations of multiple STAs in CSMA / CA-based systems, a mechanism using RTS / CTS frames can be applied. In Figure 5 the example, while the transmission of STA1 is being executed, as a result of the carrier sensing of STA3, it can be determined that the medium is idle. That is, STA1 can correspond to a hidden node of STA3. Alternatively, in Figure 5 the example, it can be determined that the medium is idle as a result of the carrier sensing of STA3 while the transmission of STA2 is being executed. That is, STA2 can correspond to a hidden node of STA3. By exchanging RTS / CTS frames before the 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 for the transmission from STA1 or STA3, may not attempt to occupy the channel during the data transmission and reception between STA1 and STA2.

[0085] Specifically, STA1 can determine whether the channel is in use through carrier sensing. In terms of physical carrier sensing, STA1 can determine the occupied or idle state of the channel 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 occupied state of the channel.

[0086] When the channel is idle during DIFS, STA1 can send an RTS frame to STA2 after performing backoff. When STA2 receives the RTS frame, STA2 can send a CTS frame to STA1 as a response to the RTS frame after SIFS.

[0087] If STA3 cannot overhear the CTS frame from STA2 but can overhear the RTS frame from STA1, STA3 can use the duration information included in the RTS frame to set the NAV timer for the subsequent consecutive frame transmission period (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame). Alternatively, if STA3 can overhear the CTS frame from STA2, although STA3 cannot overhear the RTS frame from STA1, STA3 can use the duration information included in the CTS frame to set the NAV timer for the subsequent consecutive frame transmission period (e.g., SIFS + data frame + SIFS + ACK frame). That is, if STA3 can overhear one or more of the RTS or CTS frames from one or more of STA1 or STA2, STA3 can set the NAV accordingly. When STA3 receives a new frame before the expiration of the NAV timer, STA3 can use the duration information included in the new frame to update the NAV timer. STA3 does not attempt channel access before the expiration of the NAV timer.

[0088] When STA1 receives a CTS frame from STA2, STA1 can send a data frame to STA2 after SIFS starting from the time point when the reception of the CTS frame is completed. When STA2 successfully receives the data frame, STA2 can send an ACK frame as a response to the data frame to STA1 after SIFS. When the NAV timer expires, STA3 can determine whether the channel is being used through carrier sensing. When STA3 determines during DIFS after the expiration of the NAV timer that the channel is not being used by other terminals, STA3 can attempt channel access after the contention window (CW) according to random backoff has elapsed.

[0089] Figure 6 is a diagram for explaining an example of the frame structure used in a WLAN system to which the present disclosure can be applied.

[0090] With instructions or primitives (meaning a set of instructions or parameters) from the MAC layer, the PHY layer can prepare the MAC PDU (MPDU) to be transmitted. For example, when receiving a command from the MAC layer requesting the start of PHY layer transmission, the PHY layer switches to the transmission mode and configures the information (e.g., data) provided from the MAC layer in the form of a frame and transmits it. Additionally, when the PHY layer detects a valid preamble of the received frame, the PHY layer monitors the header of the preamble and sends a command notifying the MAC layer of the start of reception.

[0091] In this way, information transmission / reception in a wireless LAN system is performed in the form of frames, and for this purpose, the PHY layer protocol data unit (PPDU) frame format is defined.

[0092] The basic PPDU frame may include a Short Training Field (STF), a Long Training Field (LTF), a Signal (SIG) field, and a Data field. The most basic PPDU format (e.g., Figure 7 the non-HT (High Throughput) shown in

[0093] may consist only of a Legacy STF (L-STF), a Legacy LTF (L-LTF), a Legacy SIG (L-SIG) field, and a Data field. Additionally, 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 fields, non-legacy STF, non-legacy LTF (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)) etc. may be included between the L-SIG field and the Data field.

[0094] The SIG field may include various information related to PPDU transmission and reception. 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 PPDU. For example, for non-HT, HT, VHT, or EHT PPDU, the value of the Length field may be determined to be a multiple of 3. For example, for HE PPDU, the value of the Length field may be determined to be a multiple of 3 + 1 or 3 + 2.

[0095] The Data field may include a SERVICE field, a Physical Layer Service Data Unit (PSDU), and PPDU Tail bits, 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 bits may be used to return the encoder to the 0 state. The Padding bits may be used to adjust the length of the Data field in a predetermined unit.

[0096] The MAC PDU is defined according to various MAC frame formats, and the basic MAC frame consists of a MAC header, a frame body, and a Frame Check Sequence (FCS). The MAC frame can be composed of MAC PDUs and is transmitted / received through the PSDU in the data part of the PPDU frame format.

[0097] The MAC header includes a Frame Control field, a Duration / ID field, an Address field, etc. The Frame Control field can include the control information required for frame transmission / reception. The Duration / ID field can be set to the time for transmitting the corresponding frame, etc. For details of the Sequence Control, QoS Control, and HT Control sub-fields of the MAC header, please refer to the IEEE 802.11 standard document.

[0098] The Null Data PPDU (NDP) format refers to the PPDU format that does not include a data field. That is, the NDP refers to a frame format that includes the PPDU preamble (i.e., the L-STF, L-LTF, L-SIG fields, and additional nonlegacy SIG, nonlegacy STF, nonlegacy LTF (if present)) in the general PPDU frame format and does not include the remainder (i.e., the data field).

[0099] Figure 7 It is a diagram showing an example of the PPDU defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0100] 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 a data field. The basic PPDU format can also be referred to as the non-HT PPDU format (as shown in Figure 7 (a)).

[0101] The HT PPDU format (IEEE 802.11n) includes HT-SIG, HT-STF, and HT-LFT fields in addition to the basic PPDU format. Figure 7 The HT PPDU format shown in (b) can be referred to as the HT-mixed format. Additionally, an HT-greenfield format PPDU can be defined, and this corresponds to a format composed 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).

[0102] An example of the VHT PPDU format (IEEE 802.11ac) includes VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields in addition to the basic PPDU format (as shown inFigure 7 as shown in (c).

[0103] An example of the HE PPDU format (IEEE 802.11ax) includes, in addition to the basic PPDU format, a Repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), and Packet Extension (PE) fields (such as Figure 7 as shown in (d). According to a detailed example of the HE PPDU format, some fields may be excluded or their lengths may vary. For example, the HE-SIG-B field is included in the HE PPDU format for Multi-User (MU), and the HE-SIG-B field is not included in the HE PPDU format for Single-User (SU). Additionally, the Trigger-Based (TB) PPDU format does not include HE-SIG-B, and the length of the HE-STF field may vary to 8 us. The High-Throughput 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 16 us. For example, RL-SIG can be configured to be the same as L-SIG. The receiving STA can learn that the received PPDU is a HE PPDU or an EHT PPDU based on the presence of RL-SIG, which will be described later.

[0104] The EHT PPDU format may include Figure 7 the EHT MU (Multi-User) in (e) and Figure 7 the EHT TB (Trigger-Based) PPDU in (f). The EHT PPDU format is similar to the HE PPDU format in that it includes RL-SIG, followed by L-SIG, but may include a U (Universal)-SIG, EHT-SIG, EHT-STF, and EHT-LTF following RL-SIG.

[0105] Figure 7 The EHT MU PPDU in (e) corresponds to a PPDU that carries 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.

[0106] Compared with the EHT MU PPDU, Figure 7 the EHT TB PPDU in (f) omits the EHT-SIG. The STA that receives a trigger for UL MU transmission (e.g., a trigger frame or a Trigger Response Scheduling (TRS)) can perform UL transmission based on the EHT TB PPDU format.

[0107] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (general signal), and EHT-SIG fields can be encoded and modulated such that even legacy STAs can attempt to demodulate and decode, and can be mapped based on the determined subcarrier frequency spacing (e.g., 312.5 kHz). These can be referred to as pre-EHT modulation fields. Next, the EHT-STF, EHT-LTF, Data, and PE fields can be encoded and modulated for demodulation and decoding by STAs that successfully decode non-legacy SIGs (e.g., U-SIG and / or EHT-SIG) and obtain the information included in the fields, and can be mapped based on the determined subcarrier frequency spacing (e.g., 78.125 kHz). These can be referred to as EHT modulation fields.

[0108] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields can be referred to as pre-HE modulation fields, and the HE-STF, HE-LTF, Data, and PE fields can be referred to as HE modulation fields. Additionally, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields can be referred to as free VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and data fields can be referred to as VHT modulation fields.

[0109] Figure 7 The U-SIG included in the EHT PPDU format can be configured based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG can have a duration of 4 us, and the U-SIG can have a total duration of 8 us. Each symbol of the U-SIG can be used to transmit 26 bits of information. For example, each symbol of the U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0110] The U-SIG can be constructed in units of 20 MHz. For example, if an 80 MHz PPDU is constructed, the U-SIG may be repeated. That is, the same 4 U-SIGs can be included in an 80 MHz PPDU. A PPDU with a bandwidth exceeding 80 MHz can include different U-SIGs.

[0111] For example, A unencoded bits can be sent via U-SIG. The first symbol of U-SIG (e.g., U-SIG-1 symbol) can send the information of the first X bits among the total A bits of information, and the second symbol of U-SIG (e.g., U-SIG-2 symbol) can send the remaining Y bits of information among the total A bits of information. The A-bit information (e.g., 52 unencoded bits) can 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 can be used to terminate the trellis of the convolutional decoder and can be set to 0.

[0112] The bit information sent by U-SIG can be divided into version-independent bits and version-dependent bits. For example, U-SIG can be included in Figure 7 a new PPDU format (e.g., UHR PPDU format) not shown, and 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 can be the same, and some or all of the version-dependent bits can be different.

[0113] For example, the size of the version-independent bits of U-SIG can be fixed or variable. The version-independent bits can 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 bits and the version-dependent bits can be called various names, such as the first control bit and the second control bit.

[0114] For example, the version-independent bits of U-SIG can include a 3-bit physical layer version identifier (PHY version identifier), and this information can indicate the PHY version of the transmitted / received PPDU (e.g., EHT, UHR, etc.). The version-independent bits of U-SIG can 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 U-SIG can include information about the length of the transmission opportunity (TXOP) and information about the BSS color ID.

[0115] For example, the version-dependent bits of U-SIG can include information that directly or indirectly indicates the PPDU type (e.g., SUPPDU, MU PPDU, TB PPDU, etc.).

[0116] Information necessary for PPDU transmission and reception may be included in the U-SIG. For example, the U-SIG may further include information about the bandwidth, information about the MCS technique applied to nonlegacy SIGs (such as EHT-SIG or UHR-SIG, etc.), information indicating whether the DCM (dual carrier modulation) technique (a technique that achieves an effect similar to frequency diversity by reusing the same signal on two subcarriers) is applied to nonlegacy SIGs, information about the number of symbols for nonlegacy SIGs, and may also include information about whether nonlegacy SIGs are generated across the entire band, etc.

[0117] Some information necessary for PPDU transmission and reception may be included in the U-SIG and / or nonlegacy SIGs (such as EHT-SIG or UHR-SIG, etc.). For example, information about the type of nonlegacy LTF / STF (such as EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information about the length of nonlegacy LTF and the CP (cyclic prefix) length, information about the GI (guard interval) applicable to nonlegacy LTF, information about the preamble puncturing applicable to the PPDU, information about the RU (resource unit) allocation, etc. may be included only in the U-SIG, only in the nonlegacy SIG, or may be indicated by a combination of the information included in the U-SIG and the information included in the nonlegacy SIG.

[0118] Preamble puncturing may refer to the transmission of a PPDU in which there is no signal in one or more frequency units within 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 larger.

[0119] In Figure 7 the example of, nonlegacy SIGs such as HE-SIG-B and EHT-SIG may include control information for the receiving STA. The nonlegacy SIG may be transmitted on at least one symbol, and one symbol may have a length of 4 us. Information about the number of symbols for EHT-SIG may be included in the previous SIG (such as HE-SIG-A, U-SIG, etc.).

[0120] Nonlegacy 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 compiled separately.

[0121] In some cases, common fields can be omitted. For example, in the compressed mode applying non - OFDMA (Orthogonal Frequency Division Multiple Access), common fields can be omitted, and multiple STAs can receive a PPDU (e.g., the data field of the PPDU) through the same frequency band. In the non - compressed mode applying OFDMA, multiple users can receive a PPDU (e.g., the data field of the PPDU) through different frequency bands.

[0122] The number of user - specific fields can be determined based on the number of users. One user - block field can include up to two user fields. Each user field can be associated with MU - MIMO allocation or can be associated with non - MU - MIMO allocation.

[0123] The common field can include CRC bits and tail bits. The length of the CRC bits can be determined to be 4 bits, and the length of the tail bits can be determined to be 6 bits and set to 000000. The common field can include RU allocation information. The RU allocation information can include information about the location of the RUs assigned to multiple users (i.e., multiple receiving STAs).

[0124] An RU can include multiple sub - carriers (or tones). When transmitting signals to multiple STAs based on OFDMA technology, RUs can be used. Additionally, even when transmitting signals to one STA, RUs can be defined. Resources can be allocated for non - legacy STF, non - legacy LTF, and data fields in units of RUs.

[0125] The applicable size of the RU can be defined according to the PPDU bandwidth. For the applied PPDU formats (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.), the RUs can be defined the same or differently. For example, in the case of an 80 - MHz PPDU, the RU placement in HE PPDU and EHT PPDU may be different. The applicable RU size, the number of RUs, and the RU location, the DC (direct current) sub - carrier location and number, the null sub - carrier location and number, the guard sub - carrier location and number, etc. for each PPDU bandwidth can be referred to as the tone plan. For example, the tone plan for high bandwidth can be defined in the form of multiple iterations of the low - bandwidth tone plan.

[0126] RUs of various sizes can 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. An MRU (Multiple RUs) is distinguished from multiple individual RUs and corresponds to a set of subcarriers composed of multiple RUs. For example, an MRU can 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. Additionally, the multiple RUs that make up an MRU can be contiguous or non-contiguous in the frequency domain.

[0127] The specific size of the RU can be reduced or enlarged. Therefore, the specific size of each RU in this disclosure (i.e., the number of corresponding tones) is not restrictive and is illustrative. Additionally, in this disclosure, within a predetermined bandwidth (e.g., 20, 40, 80, 160, 320 MHz,...), the number of RUs can vary depending on the RU size.

[0128] Figure 7 The name of each field in the PPDU format is exemplary, and the scope of this disclosure is not limited by the name. Additionally, the examples of this disclosure can be applied to Figure 7 the PPDU format illustrated in Figure 7 and to new PPDU formats that exclude some fields and / or add some fields based on the

[0129] Figure 8 is a diagram showing an example format of a trigger frame to which the content of this disclosure can be applied.

[0130] The trigger frame can allocate resources for the transmission of one or more TB PPDUs and for the transmission of a requested TB PPDU. The trigger frame can also include other information required by the STA, which sends the TB PPDU as a response. The trigger frame can include a common information field and a user information list field in the frame body.

[0131] The common information field is information that is typically applied to the transmission of one or more TB PPDUs requested by the trigger frame, such as trigger type, UL length, the presence or absence of a subsequent trigger frame (e.g., more TF), CS (Channel Sensing) request, ULBW (bandwidth), HE / EHT P160, special user information field flag, etc.

[0132] The 4-bit trigger type subfield can have values from 0 to 15. Among them, the values 0, 1, 2, 3, 4, 5, 6, and 7 of the trigger type subfield are defined to correspond to basic, BFRP (Beamforming Report Polling), MU-BAR (Multi-User Block Acknowledgment Request), MU-RTS (Multi-User Request to Send), BSRP (Buffer Status Report Polling), GCR (Groupcast with Retry), MU-BAR, BQRP (Bandwidth Query Report Polling), and NFRP (NDP Feedback Report Polling) respectively, and the values 8 to 15 are defined as reserved.

[0133] Among the common information, the trigger-related common information subfield can include information optionally included based on the trigger type.

[0134] The special user information field can be included in the trigger frame. The special user information field does not include user-specific information, but includes extended common information not provided in the common information field.

[0135] The user information list includes zero or more user information fields. Figure 8 An example of the EHT variant user information field format is shown.

[0136] The AID12 subfield basically indicates that it is the user information field of the STA with the corresponding AID. In addition, if the AID12 field has a specific predetermined value, it can be used for other purposes, such as allocating a random access (RA)-RU or being configured as a special user information field. The special user information field is a user information field that does not include user-specific information but includes extended common information not provided in the common information field. For example, the special user information field can be identified by the AID12 value of 2007, and the special user information field flag subfield within the common information field can indicate whether the special user information field is included.

[0137] The RU allocation subfield can indicate the size and location of the RU / MRU. For this purpose, the RU allocation subfield can be interpreted together with the PS160 (Primary / Secondary 160 MHz) subfield of the user information field, the UL BW subfield of the common information field, etc.

[0138] Multi-layer transmission process

[0139] Multi-layer transmission can be performed in the frequency domain (e.g., different RU / MRUs), spatial domain, or constellation domain. Multi-layer transmission can be used for the PHY layer, which can provide different robustness for different services and can perform a good trade-off between data rate and robustness.

[0140] The above multi-layer transmission process can be considered for sending multiple PSDUs to a STA in a wireless LAN system. In particular, for multi-layer transmission, in the case of allocating a RU / MRU, restriction rules, etc. can be applied to reduce signaling overhead.

[0141] Specifically, various types of data can be sent to a STA, and appropriate MCS, number of streams, and coding methods can be applied according to the characteristics of each data. That is, multiple PSDUs can be sent to a STA, and this can be performed not only based on the TDD (Time Division Duplex) method but also based on the multi-layer method (e.g., a method in which a MRU is allocated and multi-layer transmission is supported).

[0142] Hereinafter, the restriction rules applied in the case of allocating a RU / MRU and the relay transmission process based on multi-layer transmission are described.

[0143] Figure 9 is a flowchart showing a method for a first STA to transmit and receive a PPDU according to an embodiment of the present disclosure.

[0144] In the description Figure 9 and Figure 10 the first STA may be a non-AP STA, and the second STA may be an AP, but is not limited thereto. Each of the first STA and the second STA may be implemented as a non-AP STA or an AP.

[0145] The first STA may receive a first physical protocol data unit (S910) including a user field with an ultra-high reliability (UHR)-signal (SIG) field from the second STA.

[0146] Here, the user field may include i) first information indicating whether multi-layer transmission is applied to the first PPDU, and ii) second information related to each of the first PSDU and the second PSDU (included in the first PPDU).

[0147] The first STA may decode a first physical layer service unit (PSDU) allocated to a first resource unit (RU) among multiple resource units (MRU) and a second PSDU allocated to a second RU among the MRU based on the user field (S920).

[0148] As an example of the present disclosure, the first PSDU and the second PSDU may be included in the first PPDU, but are not limited thereto. The first STA may receive a first PPDU including the first PSDU and a second PPDU including the second PSDU from the second STA.

[0149] In the following, it is assumed that the first PSDU and the second PSDU are included in the first PPDU, but the method described below can also be applied to the case where the first PSDU and the second PSDU are included in the first PPDU and the second PPDU, respectively.

[0150] Here, the MRU can be allocated by at least one of an RU allocation subfield or a subfield including puncturing indication information. For example, in the case of a non - OFDMA transmission scheme, the MRU can be allocated by a subfield including puncturing indication information. As another example, in the case of an OFDMA transmission scheme, the MRU can be allocated by an RU allocation subfield.

[0151] For example, the MRU can be allocated as one of a 52 + 26 - tone MRU, a 106 + 26 - tone MRU, a 484 + 242 - tone MRU, a 996 + 484 - tone MRU, a 996 + 484 + 242 - tone MRU, a 2x996 - tone MRU, a 2x996 + 484 - tone MRU, a 3x996 - tone MRU, a 3x996 + 484 - tone MRU, or a 4x996 - tone MRU.

[0152] For example, based on the MRU being a 52 + 26 - tone MRU, the first RU allocated to the first PSDU can be a 52 - tone RU, and the second RU allocated to the second PSDU can be a 26 - tone RU. As another example, based on the MRU being a 106 + 26 - tone MRU, the first RU allocated to the first PSDU can be a 106 - tone RU, and the second RU allocated to the second PSDU can be a 26 - tone RU. As another example, based on the MRU being a 484 + 242 - tone MRU, the first RU allocated to the first PSDU can be a 484 - tone RU, and the second RU allocated to the second PSDU can be a 242 - tone RU. As another example, based on the MRU being a 996 + 484 - tone MRU, the first RU allocated to the first PSDU can be a 996 - tone RU, and the second RU allocated to the second PSDU can be a 484 - tone RU. As another example, based on the MRU being a 2x996 - tone MRU, the first RU allocated to the first PSDU can be a 996 - tone RU, and the second RU allocated to the second PSDU can be a 996 - tone RU. As another example, based on the MRU being a 3x996 - tone MRU, the first RU allocated to the first PSDU can be a 2x996 - tone RU, and the second RU allocated to the second PSDU can be a 996 - tone RU.

[0153] As another example of the present disclosure, based on the MRU being a 996 + 484 + 242 - tone MRU, the first RU allocated for the first PSDU can be a 996 - tone RU, and the second RU allocated for the second PSDU can be a 484 + 242 - tone RU. As another example, based on the MRU being a 2x996 + 484 - tone MRU, the first RU allocated for the first PSDU can be a 996 + 484 - tone RU, and the second RU allocated for the second PSDU can be a 996 - tone RU. Based on the MRU being a 3x996 + 484 - tone MRU, the first RU allocated for the first PSDU can be a 2*996 - tone RU, and the second RU allocated for the second PSDU can be a 996 + 484 - tone RU.

[0154] Moreover, the second information included in the user field can include information about the first PSDU and information about the second PSDU. For example, the information about the first PSDU can include the MCS (Modulation and Coding Scheme) associated with the first PSDU, the number of streams, and the coding method, and the information about the second PSDU can include the MCS, the number of streams, and the coding method associated with the second PSDU.

[0155] As an example of the present disclosure, if the size of the first RU is a value greater than the size of the second RU, the information about the second PSDU can be placed after the information about the first PSDU within the user field. However, this is only an embodiment, and if the size of the second RU is a value greater than the size of the first RU, the information about the second PSDU can be placed after the information about the first PSDU within the user field.

[0156] In another example of the present disclosure, 1) the MCS information including the MCS associated with the first PSDU and the MCS associated with the second PSDU, 2) the number of stream information including the number of streams associated with the first PSDU and the number of streams associated with the second PSDU, and 3) the coding scheme information including the coding scheme associated with the first PSDU and the coding scheme associated with the second PSDU can be arranged in order within the user field. That is to say, they can be arranged in order by the type of information associated with the PSDU.

[0157] However, this is only one embodiment, and the order in which the MCS information, the stream number information, and the coding method information are arranged within the user field can be changed in various ways.

[0158] As an example of the present disclosure, multi - layer - based relay transmission can be applied. Here, the first STA can be a relay STA, the second STA can be a source STA (e.g., an AP), and the third STA can be a destination STA.

[0159] Here, the user field may include third information indicating whether at least one of the first PSDU and the second PSDU is a PSDU to be sent to a third STA. The first STA may determine, based on the third information, whether one of the first PSDU or the second PSDU is a PSDU to be sent to the third STA.

[0160] For example, assume that the third information indicates that the second PSDU is a PSDU for the third STA. The second STA may send the second PSDU to the first STA via the second RU and, at the same time, send the first PSDU to the first STA via the first RU. The first STA may send the second PSDU to the third STA.

[0161] In Figure 9 the example described, the method performed by the first STA may be performed by Figure 1 a first device (100) of Figure 1 One or more processors (102) of the first device (100) of

[0162] may receive, via one or more transceivers (106), from the second STA, a first PPDU including a user field with a UHR-SIG field. The one or more processors (102) may decode, based on the user field, a first PSDU assigned to a first RU among the MRUs and a second PSDU assigned to a second RU among the MRUs. Figure 9 In addition, one or more memories (104) of the first device (100) may store instructions for performing the method described in

[0163] Figure 10 is a flowchart showing a method for a second STA to transmit and receive a PPDU according to an embodiment of the present disclosure.

[0164] The second STA may generate a first PPDU including a user field with a UHR-SIG field (S1010).

[0165] As described above, the user field may include: i) first information indicating whether multi-layer transmission is applied to the first PPDU, and ii) second information related to each of the first PSDU and the second PSDU (included in the first PPDU).

[0166] In addition, the second STA is capable of allocating RUs / MRUs to the first STA in an OFDMA or non-OFDMA manner. Examples of the first RU and the second RU allocated to each of the first PSDU and the second PSDU have been described above, and thus repeated descriptions will be omitted.

[0167] The second STA may send a first PPDU including a user field with a UHR-SIG field to the first STA (S1020).

[0168] For example, the second STA may send a first PSDU assigned to a first RU among the MRUs and a second PSDU assigned to a second RU among the MRUs to the first STA.

[0169] As another example, the second STA may send a first PSDU for the first STA and a second PSDU for a third STA (e.g., the destination STA) to the first STA. The second PSDU may be sent to the third STA via the first STA.

[0170] by Figure 10 The method performed by the AP described in the example of Figure 1 may be performed by a second device (200) of Figure 10 For example, one or more processors (202) of the second device (200) of

[0171] may generate a first PPDU including a user field with a UHR-SIG field. The one or more processors (202) may send the first PPDU including the user field with the UHR-SIG field to the first STA via one or more transceivers (206). Figure 10 In addition, one or more memories (204) of the second device (200) may store instructions for performing the method described in the example of

[0172] Hereinafter, the restriction rules applied in the case of allocating one RU / MRU and the relay transmission process based on multi-layer transmission are described in more detail.

[0173] Example 1

[0174] Embodiment 1 relates to a method for supporting multi-layer transmission when allocating one or more MRUs. The method for allocating MRUs may be the same as the MRU allocation method in a wireless LAN based on the IEEE 802.11be standard.

[0175] When applying a non-OFDMA transmission method, the MRU used in the transmission process may be specified by a puncturing indication. When applying an OFDMA transmission method, the MRU may be allocated by an RU allocation subfield.

[0176] As an example of the present disclosure, instruction information indicating the application / execution of multi-layer transmission may be sent and received. When applying / executing a multi-layer transmission process, the MCS, the number of streams, the coding method, etc. of each PSDU may be indicated.

[0177] When applying a non-OFDMA transmission method, the indication of applying / executing multi-layer transmission can be performed through the U-SIG field and / or the UHR-SIG field.

[0178] In particular, when considering the MU-MIMO case, the indication of applying / executing multi-layer transmission can be performed via the user field of the UHR-SIG field. Additionally, information indicating the number of PSDUs and information indicating MCS, the number of streams, the coding method, etc. according to each PSDU can be included in the user field (e.g., the user field of the UHR-SIG field, etc.).

[0179] Even when applying the OFDMA transmission method, the indication information indicating the application / execution of multi-layer transmission can be included in the user field of the UHR-SIG. In addition, the user field of the UHR-SIG can include information indicating the number of PSDUs and information indicating MCS, the number of streams, and the coding method for each PSDU.

[0180] In addition, information indicating to which RU / MRU each PSDU is to be sent within the allocated MRU may be required, but this may require a large number of bits, which may increase the overhead.

[0181] Hereinafter, restricted rules in multi-layer transmission are described to reduce the overhead.

[0182] Example 1-1

[0183] As an example of the present invention, the RU / MRU that can be allocated for multi-layer transmission can be a 52 + 26-tone RU / MRU, a 106 + 26-tone RU / MRU, a 484 + 242-tone RU / MRU, a 996 + 484-tone RU / MRU, a 996 + 484 + 242-tone RU / MRU, a 2x996-tone RU / MRU, a 2x996 + 484-tone RU / MRU, a 3x996-tone RU / MRU, a 3x996 + 484-tone RU / MRU, and / or a 4x996-tone RU / MRU.

[0184] In addition, small MRUs may be less useful and may not be used for multi-layer transmission.

[0185] As an example of the present disclosure, the number of PSDUs that can be sent in the RU / MRU allocated for multi-layer transmission can always be fixed. For example, in multi-layer transmission, only two PSDUs can always be sent in the allocated RU / MRU, but it is not limited thereto.

[0186] Hereinafter, assuming the above situation, a method for performing PSDU transmission within the RU / MRU that can be allocated for multi-layer transmission is described.

[0187] That is, for each RU / MRU type, it is possible to determine / set the RU / MRU to which each PSDU is to be sent, and thus, no additional signaling (i.e., signaling for indicating the RU / MRU information for each PSDU transmission) is required, thereby effectively reducing the overhead.

[0188] For example, if a 52 + 26 - tone MRU is allocated, each PSDU can be sent in each of the 52 - tone RU and the 26 - tone RU.

[0189] For example, if a 106 + 26 - tone MRU is allocated, each PSDU can be sent in each of the 106 - tone RU and the 26 - tone RU.

[0190] For example, if a 484 + 242 - tone MRU is allocated, each PSDU can be sent in the 484 - tone RU and the 242 - tone RU respectively.

[0191] For example, if a 996 + 484 - tone MRU is allocated, each PSDU can be sent in each of the 996 - tone RU and the 484 - tone RU.

[0192] For example, if a 996 + 484 + 242 - tone MRU is allocated, each PSDU can be sent in the 996 - tone RU and the 484 + 242 - tone MRU. As another example, if a 996 + 484 + 242 - tone MRU is allocated, each PSDU can be sent in the 996 + 484 - tone MRU and the 242 - tone MRU.

[0193] For example, if a 2x996 - tone MRU is allocated, each PSDU can be sent in each of the 996 - tone RU and the 996 - tone RU.

[0194] For example, if a 2x996 + 484 - tone MRU is allocated, each PSDU can be sent in the 996 + 484 - tone MRU and the 996 - tone RU. As another example, if a 2x996 + 484 - tone MRU is allocated, each PSDU can be sent in the 2x996 - tone MRU and the 484 - tone RU.

[0195] For example, if a 3x996 + 484 - tone MRU is allocated, each PSDU can be sent in the 2x996 - tone RU and the 996 + 484 - tone MRU. Also, if a 3x996 + 484 - tone MRU is allocated, each PSDU can be sent in the 2x996 + 484 - tone MRU and the 996 - tone RU. Also, if a 3x996 + 484 - tone MRU is allocated, each PSDU can be sent in the 3x996 - tone MRU and the 484 - tone RU.

[0196] For example, if a 4x996 + 484 - tone MRU is allocated, each PSDU can be transmitted in two 2x996 - tone RUs. As another example, if a 4x996 + 484 - tone MRU is allocated, each PSDU can be transmitted in a 3x996 - tone MRU and a 996 - tone MRU.

[0197] The combination of MRUs among the RUs / MRUs to which each PSDU within the above - mentioned RU / MRU is transmitted can always consist of the combination of the nearest adjacent RUs.

[0198] For example, if a 2x996 + 484 - tone MRU is allocated, it is assumed that puncturing is performed as "XXXX OOXX OOOO OOOO" in a 320 - MHz bandwidth. Here, X can mean that the corresponding 20 - MHz channel is punctured, and O can mean that the corresponding 20 - MHz channel is not punctured. In addition, "XXX OOXX OOOO OOOO" indicates that the 20 - MHz bandwidths constituting the 320 - MHz channel are listed in order starting from the lowest frequency.

[0199] That is to say, "XXXX OOXX OOOO OOOO" can indicate that the first 80 - MHz channel is punctured, and the higher - frequency 40 - MHz channel in the second 80 - MHz channel is punctured. Therefore, a 484 - tone RU can be used in the second 80 - MHz channel, and a 2x996 - tone RU can be used in the higher 160 - MHz channel.

[0200] That is to say, a total of 2x996 + 484 MRUs can be used, and the 996 + 484 - tone MRUs and 996 - tone RUs transmitted by each PSDU can be set in the following combination.

[0201] 1) 996 + 484 - tone MRU: A 484 - tone RU and a 996 - tone RU on the third 80 - MHz channel.

[0202] 2) 996 - tone RU: The 996 - tone RU of the fourth 80 - MHz channel

[0203] Example 1-2 .

[0204] Embodiment 1 - 2 relates to a method for indicating information about a PSDU and configuring related fields.

[0205] As an example of the present disclosure, when information corresponding to each PSDU is indicated through a user field (for example, the user field of the UHR - SIG field), the related information can be indicated in the order of large (or small) RU / MRU sizes.

[0206] For example, when a 3x996-tone MRU is allocated for multi-layer transmission, the information of the PSDU sent in a 2x996 RU can be indicated first, and then the information of the PSDU sent in a 996-tone RU can be indicated. That is, the first field related to the information of the PSDU sent in a 2x996 RU can be placed in the user field, and the second field related to the information of the PSDU sent in a 996-tone RU can be placed after the first field.

[0207] However, this is only one example, and when a 3x996-tone MRU is allocated for multi-layer transmission, the information of the PSDU sent in a 996 RU can be indicated first, and then the information of the PSDU sent in a 2x996-tone RU can be indicated.

[0208] In another example of the present disclosure, the information of multiple PSDUs can be indicated in the order of the PSDUs. For example, the first information indicating the MCS, the number of spatial streams (NSS), and the coding, etc. for PSDU1 can be placed on the user field, and the second information indicating the MCS, NSS, and coding, etc. for PSDU2 can be placed after the first information.

[0209] As another example, the information type of each of the multiple PSDUs can be indicated. For example, the first information indicating the MCS for PSDU1 and PSDU2 can be placed on the user field, the second information indicating the NSS for PSDU1 and PSDU2 can be placed after the first information, and the coding for PSDU1 and PSDU2 can be placed after the second information.

[0210] Example 2

[0211] Relay transmission can be used to improve the range extension and signal-to-noise ratio (SNR) performance in a wireless LAN system (e.g., a UHR-based wireless LAN system). In this case, the relay STA that sends the signal from the source STA to the destination STA can not only perform the relay transmission role but also be a normal non-AP STA that implements the relay function.

[0212] Here, if it is assumed that the source STA is an AP, the AP can generate and / or save the data to be sent to the relay STA and the data to be sent to the destination STA. Hereinafter, the method for the source STA (e.g., an AP) to send the above data will be described.

[0213] Example 2-1

[0214] Embodiment 2-1 relates to a method in which a source STA transmits data for a destination STA and data for a relay STA in a TDD manner.

[0215] For example, the source STA may first send data for the relay STA and then send data for the destination STA through the relay STA. As another example, the source STA may first send data for the destination STA through the relay STA and then send data for the relay STA.

[0216] Here, additional information may be included in the PPDU that the relay STA must send to the destination STA. For example, the additional information may include information indicating that the corresponding PPDU is a PPDU that must be relayed within the PHY SIG (or MAC header) and / or the ID information of the destination STA. The ID information of the destination STA may be included in the MAC header (or PHY SIG).

[0217] That is, the relay STA may decode / identify the ID information of the destination STA to which the PPDU will be delivered through the additional information included in the PPDU of the destination STA.

[0218] Through the above method, the relay STA may amplify and forward data for the destination STA without re-encoding it after decoding it, and thus may reduce the complexity of the relay STA.

[0219] Example 2-2

[0220] Embodiment 2-2 relates to a method in which a source STA transmits data for a destination STA and data for a relay STA in an OFDMA manner.

[0221] As an example of the present disclosure, a specific RU / MRU may be assigned to the data transmission of the relay STA, and another RU / MRU may be assigned to the data transmission of the destination STA. Additionally, another RU / MRU may be assigned to the data transmission of another STA.

[0222] In this case, the relay STA may decode the data of the destination STA, re-encode it, and send it to the destination STA. Thus, the source STA may generate and send signaling related to relay transmission in the OFDMA scheme.

[0223] For example, a method of assigning multiple RU / MRUs to one STA may be added. A STA ID sub-field etc. in the user field (PHY SIG field) corresponding to a specific RU / MRU may be included, and the STA ID sub-fields of different user fields may be set the same (e.g., set to the ID of the relay STA).

[0224] Additionally, information indicating that data of a specific RU / MRU should be re-encoded and relayed after decoding (i.e., information that the data of the specific RU / MRU should be delivered to the destination STA) can be indicated via a user field (e.g., 1 bit of the user field).

[0225] Example 2-3

[0226] Embodiment 2-3 relates to a method in which a source STA transmits data for a destination STA and data for a relay STA in a multi-layer manner.

[0227] The source STA can send multiple PSDUs to the relay STA using an MRU, multiple streams, or constellation points.

[0228] As an example of the present disclosure, the multiple PSDUs can include a PSDU (i.e., data) for the relay STA and a PSDU for the destination STA.

[0229] Example 2-3-1

[0230] As an example of the present disclosure, when an MRU is allocated, data for the relay STA can be sent from a specific RU / MRU within the MRU, and data for the destination STA can be sent from the remaining RU / MRUs. The data sent from each RU / MRU can be independently encoded by the AP.

[0231] In this case, there may be only one user field mapped to the allocated MRU. It can be indicated via specific signaling within the user field that two PSDUs are being sent via the corresponding MRU. Additionally, it can be indicated that multi-layer transmission can be performed via the corresponding user field.

[0232] Additionally, the RU / MRU information of each PSDU (i.e., information indicating the RU / MRU to which each PSDU is sent), MCS, NSS, and coding, etc. can be indicated within the MRU allocated via the corresponding user field. Additionally, the corresponding user field can include information indicating whether each PSDU should be relayed (i.e., information indicating whether the corresponding PSDU is a PSDU that should be delivered to the destination STA).

[0233] As an example of the present disclosure, to reduce signaling overhead, when a multi-layer scheme is applied to a specific MRU, it can be defined / set to send only a fixed number (e.g., two) of PSDUs. And, to eliminate the signaling indicating the RU / MRU information for sending each PSDU, a scheme of always allocating a specific RU / MRU can be applied.

[0234] For example, if 484 + 996 MRUs are allocated for multi-layer transmission, they can be divided into 484-tone RUs and 996-tone RUs. Also, each PSDU can be independently encoded by being allocated to each of the 484-tone RUs and 996-tone RUs.

[0235] Example 2-3-2

[0236] As an example of the present disclosure, when using multiple streams, data for a relay STA can be sent through a specific stream among the allocated multiple streams, and data for a destination STA can be sent through the remaining streams. Data sent through each multiple stream can be independently encoded by the AP.

[0237] Here, the user field corresponding to all the allocated streams can be one (e.g., the user field related to the relay STA). However, multi-layer transmission can be indicated through specific signaling, and the number of streams for sending each PSDU (i.e., data) and information such as MCS / encoding can be indicated through the corresponding user field. Additionally, it can be indicated through the corresponding user field whether each PSDU is a PSDU to be relayed (i.e., whether each PSDU is a PSDU to be delivered to the destination STA).

[0238] To reduce signaling overhead, when performing multi-layer-based transmission, only a specific number of PSDUs (e.g., two PSDUs) can be sent.

[0239] Also, when indicating information about the total number of streams and multi-layer transmission, if the number of streams for each PSDU (i.e., data) is even, half of the total streams can be allocated to the streams of each PSDU. And if the number of streams for each PSDU is odd, the floor function value and ceiling function value of half of the total streams can be allocated to each PSDU.

[0240] Example 2-3-3

[0241] As an example of the present disclosure, when using constellation points, data for a relay STA can be sent through specific bits within the constellation points, and data for a destination STA can be sent through the remaining bits. Data transmitted through the above bits of the constellation points can be independently encoded by the AP.

[0242] Here, the user field corresponding to the allocated constellation point may be one (e.g., the user field related to the relay STA), but multi-layer transmission can be indicated by specific signaling. In addition, information such as bits, MCS, NSS, and the coding within the constellation point for transmitting each PSDU (e.g., data) can be indicated by the corresponding user field.

[0243] Also, through the user field, it can be indicated whether each PSDU is a PSDU that should be relayed (i.e., whether each PSDU is a PSDU that should be delivered to the destination STA).

[0244] To reduce signaling overhead, when performing multi-layer based transmission, only a specific number of PSDUs (e.g., two PSDUs) can be sent. When multi-layer transmission is indicated, the information regarding the entire constellation point (i.e., modulation level) and each specific bit used for transmitting each PSDU can always be fixed.

[0245] For example, when using 16QAM, data for the destination STA can be sent via the first and third bits among 4 bits, and data for the relay STA can be sent via the second and fourth bits. However, the present invention is not limited thereto, data for the destination STA can be sent via the second and fourth bits among 4 bits, and data for the relay STA can be sent via the first and third bits.

[0246] The above embodiments combine the elements and features of the present disclosure in a predetermined form. Unless otherwise explicitly mentioned, each element or feature should be considered optional. Each element or feature can be implemented in a form that does not combine with other elements or features. In addition, the embodiments of the present disclosure can include combining some elements and / or features. The order of operations described in the embodiments of the present disclosure can be changed. Some elements or features of one embodiment can be included in other embodiments, or can be replaced by the corresponding elements or features of other embodiments. Clearly, the embodiments can include combining claims without explicit dependency relationships in the claims, or can be included as new claims through amendment after the application.

[0247] Those skilled in the art will appreciate that the present disclosure can be implemented in other specific forms without departing from the essential features of the present disclosure. Therefore, the above detailed description should not be construed restrictively in every aspect, but should be considered illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present disclosure are included within the scope of the present invention.

[0248] The scope of the present disclosure includes software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that perform operations according to various embodiments in a device or computer, and non-transitory computer-readable media that store such software or instructions, etc. and can be executed in the device or computer. Instructions that can be used to program a processing system for performing the features described in the present disclosure can be stored in a storage medium or 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 can include 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 can include non-volatile memory, such as one or more disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory optionally includes one or more storage devices located remotely from the processor. The memory or alternatively, the non-volatile memory device in the memory includes a non-transitory computer-readable storage medium. The features described in the present disclosure can be stored in any kind of machine-readable medium to control the hardware of the processing system, and can be integrated into software and / or firmware that allows the processing system to interact with other mechanisms using the results from the embodiments of the present disclosure. Such software or firmware can include application code, device drivers, operating systems, and execution environments / containers, but is not limited thereto.

[0249]

Industrial Applicability

[0250] The method proposed by the present disclosure is mainly described based on an example applied to an IEEE 802.11-based system, but can also be applied to various WLANs or wireless communication systems other than IEEE 802.11-based systems.

Claims

1. A method performed by a first station (STA) in a wireless LAN system, the method comprising: Receiving a first physical protocol data unit (PPDU) from a second STA, the first PPDU including a user field of an ultra-high reliability (UHR)-signal (SIG) field; and Based on the user field, decoding a first physical layer service data unit (PSDU) assigned to a first resource unit (RU) among a plurality of resource units (MRUs) and a second PSDU assigned to a second RU among the MRUs, Wherein the user field includes: i) first information indicating whether multi-layer transmission is applied to the first PPDU, and ii) second information related to each of the first PSDU and the second PSDU.

2. The method according to claim 1, wherein: The MRU is one of a 52+26-tone MRU, a 106+26-tone MRU, a 484+242-tone MRU, a 996+484-tone MRU, a 996+484+242-tone MRU, a 2x996-tone MRU, a 2x996+484-tone MRU, a 3x996-tone MRU, a 3x996+484-tone MRU, or a 4x996-tone MRU.

3. The method according to claim 2, wherein: Based on the MRU being a 52+26-tone MRU: the first RU is a 52-tone RU and the second RU is a 26-tone RU, Based on the MRU being a 106+26-tone MRU: the first RU is a 106-tone RU and the second RU is a 26-tone RU, Based on the MRU being a 484+242-tone MRU: the first RU is a 484-tone RU and the second RU is a 242-tone RU, Based on the MRU being a 996+484-tone MRU: the first RU is a 996-tone RU and the second RU is a 484-tone RU, Based on the MRU being a 2x996-tone MRU: the first RU is a 996-tone RU and the second RU is a 996-tone RU, and Based on the MRU being a 3x996-tone MRU: the first RU is a 2x996-tone RU and the second RU is a 996-tone RU.

4. The method according to claim 2, wherein: Based on the MRU being a 996+484+242-tone MRU: the first RU is a 996-tone RU and the second RU is a 484+242-tone RU, Based on the MRU being a 2x996+484-tone MRU: the first RU is a 996+484-tone MRU and the second RU is a 996-tone RU, and Based on the MRU being a 3x996+484-tone MRU: the first RU is a 2*996-tone RU and the second RU is a 996+484-tone MRU.

5. The method according to claim 1, wherein: The second information includes information about the first PSDU and information about the second PSDU. The information about the first PSDU includes the MCS (Modulation and Coding Scheme) associated with the first PSDU, the number of streams, and the coding method, and the information about the second PSDU includes the MCS, the number of streams, and the coding method associated with the second PSDU.

6. The method according to claim 5, wherein: Based on the size of the first RU being a value greater than the size of the second RU, the information about the second PSDU in the user field follows the information about the first PSDU.

7. The method according to claim 5, wherein: 1) MCS information including the MCS associated with the first PSDU and the MCS associated with the second PSDU, 2) stream number information including the number of streams associated with the first PSDU and the number of streams associated with the second PSDU, and 3) coding method information including the coding method associated with the first PSDU and the coding method associated with the second PSDU are arranged sequentially in the user field.

8. The method according to claim 5, wherein: The user field includes third information indicating whether at least one of the first PSDU and the second PSDU is a PSDU to be sent to a third STA.

9. The method according to claim 8, wherein: The first STA is a relay STA, The second STA is a source STA, and The third STA is a destination STA.

10. The method according to claim 1, wherein: The MRU is allocated by at least one of a RU allocation subfield or a subfield including puncturing indication information.

11. A first station (STA) operating in a wireless LAN system, the first STA comprising: At least one transceiver; And At least one processor connected to the at least one transceiver, wherein the at least one processor is configured to: Receive, via the at least one transceiver, a first physical protocol data unit (PPDU) from a second STA, the first PPDU including a user field of a very high reliability (UHR)-signal (SIG) field; and Based on the user field, decode a first physical layer service data unit (PSDU) allocated to a first resource unit (RU) among a plurality of resource units (MRUs) and a second PSDU allocated to a second RU among the MRUs, wherein the user field includes: i) first information indicating whether multi-layer transmission is applied to the first PPDU, and ii) second information related to each of the first PSDU and the second PSDU.

12. A method performed by a second station (STA) in a wireless LAN system, the method comprising: Generate a first physical protocol data unit (PPDU), the first PPDU including a user field of a very high reliability (UHR)-signal (SIG) field; And Send the first PPDU to a first STA, Among them, a first resource unit (RU) among multiple resource units (MRUs) is allocated to a first physical layer service data unit (PSDU), and a second RU among the MRUs is allocated to a second PSDU, and wherein, the user field includes: i) first information indicating whether multi-layer transmission is applied to the first PPDU, and ii) second information related to each of the first PSDU and the second PSDU.

13. A second station (STA) operating in a wireless LAN system, the second STA comprising: At least one transceiver; And At least one processor, the at least one processor being connected to the at least one transceiver, wherein, the at least one processor is configured to: Generate a first physical protocol data unit (PPDU), the first PPDU including a user field of an ultra-high reliability (UHR)-signal (SIG) field; and Transmit the first PPDU to a first STA via the at least one transceiver, Among them, a first resource unit (RU) among multiple resource units (MRUs) is allocated to the first physical layer service data unit (PSDU), and a second RU among the MRUs is allocated to a second PSDU, and wherein, the user field includes: i) first information indicating whether multi-layer transmission is applied to the first PPDU, and ii) second information related to each of the first PSDU and the second PSDU.

14. A processing device configured to control a first station (STA) in a wireless LAN system, the processing device comprising: At least one processor; And At least one computer memory, the at least one computer memory being operably coupled to the at least one processor and storing instructions for performing operations when executed by the at least one processor; The operations include: Receive a first physical protocol data unit (PPDU) from a second STA, the first PPDU including a user field of an ultra-high reliability (UHR)-signal (SIG) field; and Based on the user field, decode a first physical layer service data unit (PSDU) allocated to a first resource unit (RU) among multiple resource units (MRUs) and a second PSDU allocated to a second RU among the MRUs, wherein, the user field includes: i) first information indicating whether multi-layer transmission is applied to the first PPDU, and ii) second information related to each of the first PSDU and the second PSDU.

15. At least one non-transitory computer-readable medium, the non-transitory computer-readable medium storing at least one instruction, Based on the execution of the at least one instruction by at least one processor, for controlling a device for communication in a wireless LAN system: Receive a first physical protocol data unit (PPDU) from a second STA, the first PPDU including a user field of an ultra-high reliability (UHR)-signal (SIG) field; and Based on the user field, decode a first physical layer service data unit (PSDU) assigned to a first resource unit (RU) among multiple resource units (MRUs) and a second PSDU assigned to a second RU among the MRUs. Among them, The user field includes: i) first information indicating whether multi-layer transmission is applied to the first PPDU, and ii) second information associated with each of the first PSDU and the second PSDU.

Images