Method and apparatus for performing PPDU transmission and reception based on parameter set selection in wireless LAN system

Abstract

Disclosed are a method and an apparatus for performing PPDU transmission and reception based on parameter set selection in a wireless LAN system. According to an embodiment disclosed herein, a method performed by a first STA in a wireless LAN system may comprise the steps of: receiving a PPDU including information indicating one of a plurality of bandwidth candidates from a second STA; and processing the PPDU in the bandwidth indicated by the information. Here, the plurality of bandwidth candidates may be defined to be constructed by applying a first upconversion element to a first bandwidth candidate group, and at least one of the plurality of bandwidth candidates may be defined to be constructed by applying a second upconversion element to a second bandwidth candidate group instead of applying the first upconversion element.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for transmitting and receiving a PPDU in a bandwidth based on a parameter set selection in a wireless local area network (WLAN) system. Background Art

[0002] New technologies for improving transmission rate, increasing bandwidth, improving reliability, reducing errors, and reducing latency have been introduced for wireless local area networks (WLANs). 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, recently introduced technologies for WLANs include very high throughput (VHT) enhancements of the 802.11ac standard and high efficiency (HE) enhancements of the IEEE 802.11ax standard.

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

[0004] Technical Problem

[0005] A technical object of the present disclosure is to provide a method and apparatus for performing PPDU transmission and reception in a bandwidth based on a parameter set selection in a wireless local area network (WLAN) system.

[0006] A technical object of the present disclosure is to provide a method and apparatus for performing PPDU transmission and reception in a bandwidth configured by applying upclocking to a selected parameter set in a millimeter wave (mmWave) band in a wireless local area network system.

[0007] The technical objects to be achieved by the present disclosure are not limited to the above technical objects, and other technical objects not described herein will be clearly understood by those skilled in the art from the following description.

[0008] Technical Solution

[0009] According to one aspect 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 physical layer protocol data unit (PPDU) including information indicating one of a plurality of bandwidth candidates; and processing the PPDU in the bandwidth indicated by the information. Here, the plurality of bandwidth candidates may be defined as being configured by applying a first frequency scaling factor to a first bandwidth candidate group, and based on a predefined criterion, at least one of the plurality of bandwidth candidates may be defined as being configured by applying a second frequency scaling factor to a second bandwidth candidate group, rather than applying the first frequency scaling factor.

[0010] According to an additional aspect of the present disclosure, a method performed by a second station (STA) in a wireless LAN system may include: constructing a physical layer protocol data unit (PPDU) including information indicating one of a plurality of bandwidth candidates; and transmitting the PPDU to the first STA in the bandwidth indicated by the information. Wherein, the plurality of bandwidth candidates may be defined as being configured by applying a first frequency scaling factor to a first bandwidth candidate group, and based on a predefined criterion, at least one of the plurality of bandwidth candidates may be defined as being configured by applying a second frequency scaling factor to a second bandwidth candidate group, rather than applying the first frequency scaling factor.

[0011] Technical effects

[0012] According to the present disclosure, a method and apparatus for transmitting and receiving a PPDU in a bandwidth based on parameter set selection in a wireless local area network (WLAN) system may be provided.

[0013] According to the present disclosure, a method and apparatus for transmitting and receiving a PPDU in a bandwidth configured by applying frequency scaling to a selected parameter set in a millimeter wave (mmWave) band of a wireless LAN system may be provided.

[0014] According to the present disclosure, there is an advantage that high data rate and low latency can be achieved by supporting the millimeter wave band in a wireless LAN system.

[0015] The effects that can be achieved by the present disclosure are not limited to the above effects, and those skilled in the relevant art can clearly understand other effects not described herein through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are included as a part of the specific embodiments for understanding the present disclosure, provide embodiments of the present disclosure and describe the technical features of the present disclosure together with the specific embodiments.

[0017] Figure 1 A configuration block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0018] Figure 2It is a diagram illustrating an exemplary structure of a WLAN system to which the present disclosure can be applied.

[0019] Figure 3 It is a diagram for explaining a link establishment process to which the present disclosure can be applied.

[0020] Figure 4 It is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0021] Figure 5 It is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0022] Figure 6 It is a diagram for explaining an example of a frame structure used in a WLAN system to which the present disclosure can be applied.

[0023] Figure 7 It is a diagram illustrating an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0024] Figure 8 It is a diagram for explaining an example of a resource unit of a wireless LAN system to which the present disclosure can be applied.

[0025] Figure 9 It is a diagram for explaining an example of a resource unit of a wireless LAN system to which the present disclosure can be applied.

[0026] Figure 10 It is a diagram for explaining an example of a resource unit of a wireless LAN system to which the present disclosure can be applied.

[0027] Figure 11 It is a diagram showing an example of a region of channelization of a millimeter wave (mmWave) band to which the present disclosure can be applied.

[0028] Figure 12 It illustrates an operation flowchart of a first STA according to an embodiment of the present disclosure.

[0029] Figure 13 It illustrates an operation flowchart of a second STA according to an embodiment of the present disclosure. Detailed Embodiments

[0030] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description to be disclosed through the drawings is to describe exemplary embodiments of the present disclosure, not to 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.

[0031] 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 of the concepts of the present disclosure.

[0032] In the present disclosure, when an element is referred to as being "connected", "combined" or "linked" to another element, it may include an indirect connection relationship as well as 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.

[0033] In the present disclosure, terms such as "first", "second", etc. are used only to distinguish one element from another and do not limit the element, unless otherwise stated, and do not limit the order or importance, etc. between the elements. Thus, within the scope of the present disclosure, the first element in one embodiment may be referred to as the second element in another embodiment, and similarly, the second element in one embodiment may be referred to as the first element in another embodiment.

[0034] The terms used in the present disclosure are for the purpose of describing particular 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 may mean that it refers to and includes any and all possible combinations of two or more of them. Further, unless otherwise stated, " / " between words in the present disclosure has the same meaning as "and / or".

[0035] Examples of the present disclosure may be applied to various wireless communication systems. For example, examples of the present disclosure may be applied to a wireless LAN system. For example, examples of the present disclosure may be applied to a wireless LAN based on the IEEE 802.11a / g / n / ac / ax standards. Further, examples of the present disclosure may be applied to a wireless LAN based on the newly proposed IEEE 802.11be (or EHT) standard. Examples of the present disclosure may 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 may be applied to a wireless LAN based on a next-generation standard after IEEE 802.11be. Further, examples of the present disclosure may be applied to a cellular wireless communication system. For example, it may be applied to a cellular wireless communication system based on long-term evolution (LTE) technology and 5G new radio (NR) technology based on the 3rd Generation Partnership Project (3GPP) standards.

[0036] In the following, the technical features of examples to which the present disclosure can be applied will be described.

[0037] Figure 1 A block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0038] Figure 1 The first device 100 and the second device 200 illustrated in can be replaced with 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. Additionally, the first device 100 and the second device 200 include an access point (AP), a base station (BS), a fixed station, a Node B, a base transceiver system (BTS), a network. It can be replaced with various terms such as an artificial intelligence (AI) system, a roadside unit (RSU), a repeater, a router, a relay, and a gateway.

[0039] Figure 1 The devices 100 and 200 illustrated in can be referred to as a station (STA). For example, Figure 1 The devices 100 and 200 illustrated in can be referred to by various terms such as a transmitting device, a receiving device, a transmitting STA, and a receiving STA. For example, STA110 and 200 can perform an access point (AP) role or a non-AP role. That is, in the present disclosure, STA110 and 200 can perform AP and / or non-AP functions. When STA 110 and 200 perform the AP function, they can be simply referred to as an AP, and when STA 110 and 200 perform the non-AP function, they can be simply referred to as an STA. Additionally, in the present disclosure, an AP can also be indicated as an AP STA.

[0040] Referring to Figure 1 , the first device 100 and the second device 200 can transmit and receive radio signals through various wireless LAN technologies (e.g., the IEEE802.11 series). The first device 100 and the second device 200 can include an interface for a media access control (MAC) layer and a physical layer (PHY) that conforms to the IEEE802.11 standard.

[0041] In addition to the wireless LAN technology, the first device 100 and the second device 200 may additionally support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, etc.). Additionally, the devices of the present disclosure may be implemented in various devices such as mobile phones, vehicles, personal computers, augmented reality (AR) devices, and virtual reality (VR) devices. Additionally, the STA in this specification may support various communication services such as voice calls, video calls, data communication, autonomous driving, machine type communication (MTC), machine-to-machine (M2M), device-to-device (D2D), and Internet of Things (IoT).

[0042] 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, suggestions, methods, and / or operation flowcharts included in the present disclosure. For example, after generating first information / signals by processing the information in the memory 104, the processor 102 may send a wireless signal including the first information / signals through the transceiver 106. Additionally, the processor 102 may receive a wireless signal including second information / signals through the transceiver 106, and then store the information obtained by signal processing of the second information / signals in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software codes including instructions for performing all or part of the processing controlled by the processor 102 or for performing the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts included in the present disclosure. Here, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., IEEE 802.11 series). The transceiver 106 may be connected to the processor 102 and may send and / or receive wireless signals through one or more antennas 108. The transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used with an RF (radio frequency) unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0043] 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, suggestions, methods, and / or operation flowcharts included in the present disclosure. For example, the processor 202 may generate third information / signals by processing the information in the memory 204, and then transmit wireless signals including the third information / signals through the transceiver 206. Additionally, the processor 202 may receive wireless signals 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 codes including instructions for performing all or part of the processing controlled by the processor 202 or for performing the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts included in the present disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement wireless LAN technologies (e.g., the IEEE 802.11 series). The transceiver 206 may be connected to the processor 202 and may transmit 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 the present disclosure, a device may mean a communication modem / circuit / chip.

[0044] Hereinafter, the hardware components of apparatuses 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, suggestions, methods, and / or operation flowcharts disclosed in the present disclosure. One or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or operation flowcharts disclosed in the present 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, suggestions, and / or methods disclosed in the present 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 according to the descriptions, functions, procedures, suggestions, methods, and / or operation flowcharts included in the present disclosure, and obtain PDUs, SDUs, messages, control information, data, or information.

[0045] One or more processors 102 and 202 may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processor 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, suggestions, methods, and / or operation flowcharts included in the present disclosure may be implemented by using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The firmware or software configured to execute the descriptions, functions, procedures, suggestions, methods, and / or operation flowcharts included in the present 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, suggestions, methods, and / or operation flowcharts included in the present disclosure may be implemented by using firmware or software in the form of codes, instructions, and / or instruction sets.

[0046] One or more memories 104, 204 may be connected to one or more processors 102, 202 and may store data, signals, messages, information, programs, code, instructions, and / or commands in various forms. One or more 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. Additionally, 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.

[0047] 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, suggestions, 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. Additionally, 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. Additionally, 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, suggestions, methods, and / or operation flowcharts, etc. included in the present disclosure through one or more antennas 108, 208. In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106, 206 may convert the received wireless signals / channels, etc. from RF band signals into baseband signals to process the received user data, control information, wireless signals / channels, etc. by using one or more processors 102, 202. One or more transceivers 106, 206 may convert the user data, control information, wireless signals / channels, etc. processed by using one or more processors 102, 202 from baseband signals into RF band signals. Thus, one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

[0048] For example, one of the STAs 100 and 200 may perform the expected operations of an AP, and the other of the STAs 100 and 200 may perform the expected operations of a non-AP STA. For example, Figure 1 the transceivers 106 and 206 may perform the operations of sending and receiving signals (e.g., packets or physical layer protocol data units (PPDUs) compliant with IEEE 802.11a / b / g / n / ac / ax / be / bn). Additionally, in the present disclosure, the operations of various STAs generating transmission / reception signals or pre-performing data processing or calculations on the transmission / reception signals may be performed by Figure 1The processors 102 and 202 execute. For example, examples of operations for generating transmission / reception signals or performing data processing or calculations on transmission / reception signals in advance may include: 1) determining / acquiring / configuring / calculating / decoding / encoding bit information of fields (signals (SIG), short training fields (STF), long training fields (LTF), data, etc.) included in a PPDU; 2) determining / configuring / acquiring time resources or frequency resources (e.g., subcarrier resources) for fields (SIG, STF, LTF, data, etc.) included in a PPDU; 3) determining / configuring / acquiring a specific sequence (e.g., pilot sequence, STF / LTF sequence, additional sequence applied to SIG) for fields (SIG, STF, LTF, data, etc.) included in a PPDU operation; 4) power control operations and / or power saving operations applied to a STA; 5) operations related to ACK signal determination / acquisition / configuring / calculating / decoding / encoding, etc. 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 / acquire / configure / calculate / decode / encode transmission signals and reception signals may be stored in Figure 1 the memories 104 and 204.

[0049] Hereinafter, a downlink (DL) may refer to a link for communication from an AP STA to a non-AP STA, and DL PPDUs / packets / signals may be transmitted and received through the DL. In DL communication, the transmitter may be part of the AP STA, and the receiver may be part of the non-AP STA. An uplink (UL) may refer to a link for communication from a non-AP STA to an AP STA, and UL PPDUs / packets / signals may be transmitted and received through the UL. In UL communication, the transmitter may be part of the non-AP STA, and the receiver may be part of the AP STA.

[0050] Figure 2 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure may be applied.

[0051] The structure of a wireless LAN system may be composed of multiple components. A wireless LAN that supports STA mobility transparent to the upper layer may 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 included as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). Figure 2The ellipse representing the BSS can also be understood as representing the coverage area where STAs included in the corresponding BSS maintain communication. This area can be referred to as the Basic Service Area (BSA). When an STA moves outside the BSA, it cannot directly communicate with other STAs within the BSA.

[0052] If the DS shown in Figure 2 is not considered, the most basic BSS type in a wireless LAN is the 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 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 referred to as 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 be composed of mobile STAs and are not allowed to access the Distributed System (DS), thus forming a self-contained network.

[0053] The membership of STAs in a BSS can be dynamically changed by turning STAs on or off, entering or exiting the BSS area, etc. To become a member of a BSS, an STA can use synchronization processing to join the BSS. To access all services of the BSS infrastructure, an STA should be associated with the BSS. This association can be dynamically established and can include using the Distribution System Service (DSS).

[0054] The direct STA-to-STA distance in a wireless LAN may be limited by the PHY performance. In some cases, this distance limitation may be sufficient, but in some cases, communication between STAs at longer distances may be required. The Distributed System (DS) can be configured to support extended coverage.

[0055] DS means the structure for interconnecting BSSs. Specifically, as Figure 2As shown, the BSS can exist as an extended form of a network composed 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, nor are they limited to being different. In this way, the flexibility of the wireless LAN structure (DS structure or other network structures) can be interpreted as multiple media being logically different. That is, the wireless LAN structure can be implemented in various ways, and the corresponding wireless LAN structure can be independently specified by the physical characteristics of each implementation.

[0056] The DS can support mobile devices by providing seamless integration of multiple BSSs and providing the logical services necessary for addressing the addresses to the destination. Additionally, the DS can also include a component called a portal, which is used as a bridge for the connection between the wireless LAN and other networks (e.g., IEEE 802.X).

[0057] 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 STA function. The data movement between the BSS and the DS can be performed by the AP. For example, Figure 2 STA2 and STA3 shown in have the function 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 is not necessarily the same as the address used by the AP for communication on the DSM. The BSS composed of an AP and one or more STAs can be called an infrastructure BSS.

[0058] Data sent from one of the STAs associated with the AP to the STA address of the corresponding AP can always be received at the uncontrolled port and can be processed by the IEEE 802.1X port access entity. Additionally, when the controlled port is authenticated, the sent data (or frame) can be delivered to the DS.

[0059] In addition to the above DS structure, the extended service set (ESS) can also be configured to provide wide coverage.

[0060] An ESS refers to a network consisting of a DS and BSSs with arbitrary size and complexity. An ESS can correspond to a set of BSSs connected to a DS. However, an ESS does not include the DS. The ESS network is characterized by being regarded 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 (within the same ESS) transparently 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 a BSS.

[0061] The wireless LAN system does not assume anything about the relative physical positions of 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 can be physically unconnected, and logically, there is no limit to the distance between BSSs. Additionally, BSSs can be physically located at the same position, which can be used to provide redundancy. Additionally, one (or more than one) IBSS or ESS network can physically exist in the same space as one (or more than one) ESS network. This can correspond to forms of ESS networks when an ad hoc network operates at the location where an ESS network exists, when physically overlapping wireless networks are configured by different organizations, or when two or more different access and security policies are required at the same position.

[0062] Figure 3 is a diagram for explaining the link establishment process to which the present disclosure can be applied.

[0063] In order for an STA to establish a link with respect to a network and send / receive data, it first discovers the network, performs authentication, establishes an association, and an authentication process is required for security. The link establishment process can also be referred to as a session initiation process or a session establishment process. Additionally, the processes of discovery, authentication, association, and security establishment in the link establishment process can be collectively referred to as an association process.

[0064] 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 it can participate in. The STA should identify compatible networks before participating in a wireless network, and the process of identifying the networks existing in a specific area is called scanning.

[0065] Scanning schemes include active scanning and passive scanning. Figure 3A network discovery operation including an active scanning process is exemplarily illustrated. In active scanning, the STA performing the scan sends a probe request frame to discover which APs exist around it while moving across channels and waits for a response thereto. The responder sends a probe response frame as a response to the probe request frame to the STA that has sent the probe request frame. Here, the responder can be the STA that last sent a beacon frame in the BSS of the channel being scanned. In a BSS, since the AP sends a beacon frame, the AP becomes the responder, and in an IBSS, the STAs in the IBSS rotate to send 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, move to the next channel (e.g., channel 2), and perform the scan in the same way (i.e., send and receive probe requests / responses on channel 2).

[0066] Although not shown in Figure 3 it, the scan operation can be performed in a passive scanning manner. In passive scanning, the STA performing the scan waits for beacon frames while moving across channels. A beacon frame is one of the management frames defined in IEEE 802.11 and is periodically sent to notify the existence of a wireless network and allow the STA performing the scan to find the wireless network and participate in the wireless network. In a BSS, the AP is used to periodically send beacon frames, and in an IBSS, the STAs within the IBSS rotate to send beacon frames. When the STA performing the scan receives a beacon frame, the STA stores the information of the BSS included in the beacon frame and, while moving to another channel, records the beacon frame information in each channel. The STA that receives a 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 with passive scanning, the advantage of active scanning is that it has less latency and less power consumption than passive scanning.

[0067] After the STA discovers the network, the authentication process can be performed in step S320. To clearly distinguish it from the security establishment operation in step S340 to be described later, this authentication process can be referred to as the first authentication process.

[0068] The authentication process includes the following process: The STA sends an authentication request frame to the AP, and in response thereto, the AP sends an authentication response frame to the STA. The authentication frame for authentication request / response corresponds to a management frame.

[0069] 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 information that can be included in the authentication request / response frame, and can be replaced with other information, or additional information can also be included.

[0070] The STA can send an authentication request frame to the AP. The AP can determine whether to allow 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 through an authentication response frame.

[0071] After the STA is successfully authenticated, the association process can be performed in step S330. The association process includes the following processes: the STA sends an association request frame to the AP, and in response, the AP sends an association response frame to the STA.

[0072] For example, the association request frame can include information related to various capabilities, a beacon listening interval, a Service Set Identifier (SSID), supported rates, supported channels, RSN, a mobility domain, supported operation classes, a Traffic Indication Map Broadcast Request (TIM broadcast request), an interworking service capability, etc. For example, the association response frame can include information related to various capabilities, a status code, an Association ID (AID), supported rates, an Enhanced Distributed Channel Access (EDCA) parameter set, a Received Channel Power Indicator (RCPI), a Received Signal-to-Noise Ratio Indicator (RSNI), a mobility domain, a timeout interval (e.g., an association recovery time), overlapping BSS scan parameters, a TIM broadcast response, a Quality of Service (QoS) map, etc. This corresponds to some examples of information that can be included in the association request / response frame, and can be replaced with other information, or additional information can also be included.

[0073] After the STA is successfully associated with the network, the security establishment process can be performed in step S340. The security establishment process in step S340 can be referred to as an authentication process through Robust Security Network Association (RSNA) request / response. The authentication process in step S320 is referred to as the first authentication process, and the security establishment process in step S340 can also simply be referred to as an authentication process.

[0074] The security establishment process in step S340 can, for example, include a process of establishing a private key using the Extensible Authentication Protocol over LAN (EAPOL) frame through a four-way handshake. Additionally, the security establishment process can be performed according to a security scheme not defined in the IEEE 802.11 standard.

[0075] Figure 4 It is a diagram for explaining the backoff process to which the present disclosure can be applied.

[0076] 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, before starting to transmit, the AP and / or STA can perform a Clear Channel Assessment (CCA) of sensing the radio channel or medium during a predetermined time interval (e.g., the DCF Interframe Space (DIFS)). 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 for medium access (e.g., a random backoff period) and attempt frame transmission after waiting. By applying the random backoff period, since it is expected that multiple STAs will attempt frame transmission after waiting for different time periods, collisions can be minimized.

[0077] 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. In addition, the HCF has an Enhanced Distributed Channel Access (EDCA) and an HCF Control Channel Access (HCCA). The EDCA is a contention-based access method that provides data frames to multiple users in a directed manner, and the HCCA uses a non-contention-based channel access method that utilizes a polling mechanism. In addition, the HCF includes a medium access mechanism for improving the Quality of Service (QoS) of the wireless LAN and can transmit QoS data during a Contention Period (CP) and a Contention-Free Period (CFP).

[0078] Refer to Figure 4, operations based on a random backoff period will be described. When the occupied / busy medium becomes idle, multiple STAs can attempt to transmit data (or frames). As a method to minimize collisions, each of the STAs can separately select a random backoff count and attempt to transmit 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 that vary from 0 to the value of CW. Here, CW is the contention window parameter value. The CW parameter is given the initial value of CWmin, but can take a value twice as large in the case of a transmission failure (e.g., when an ACK for the transmitted frame is not received). 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,...).

[0079] When the random backoff process starts, the STA continuously monitors the medium during the countdown of the backoff slot according to the determined backoff count value. When monitoring the medium for occupancy, it stops the countdown and waits, and when the medium becomes idle, it resumes the remaining part of the countdown.

[0080] In Figure 4 the example, when the packet to be transmitted arrives at the MAC of STA3, STA3 can transmit the frame immediately after confirming that the medium has been idle for up to DIFS. The remaining STAs monitor and wait for the medium to be occupied / busy. Meanwhile, the data to be transmitted can also occur in each of STA1, STA2, and STA5, and when the medium is monitored as idle, each STA waits for up to DIFS and then can perform the countdown of the backoff slot according to the random backoff count value selected by each STA. Assume that STA2 selects the minimum backoff count value and STA1 selects the maximum backoff count value. That is, it is exemplified that the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1 when STA2 completes the backoff count and starts frame transmission. STA1 and STA5 temporarily stop the countdown and wait while STA2 occupies the medium. When the occupancy of STA2 ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and resume the stopped backoff count. That is, frame transmission can start after counting down the remaining backoff slots for the remaining backoff time. Since the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1, STA5 starts frame transmission. While STA2 occupies the medium, the data to be transmitted can also occur in STA4. From the perspective of STA4, when the medium becomes idle, STA4 can wait for DIFS and then can perform the countdown according to the random backoff count value selected by STA4 and start transmitting the frame. Figure 4The example shows a situation where the remaining backoff time of STA5 accidentally conflicts with the random backoff counter value of STA4. In this case, a conflict may occur between STA4 and STA5. When a conflict occurs, neither STA4 nor STA5 receives an ACK, so the data transmission fails. In this case, STA4 and STA5 can double the CW value, select a random backoff counter value, and perform countdown. When the medium is occupied due to the transmissions of STA4 and STA5, STA1 waits. When the medium becomes idle, STA1 waits for the DIFS, and then starts frame transmission after the remaining backoff time has passed.

[0081] As in Figure 4 the example, a data frame is a frame for transmitting data forwarded to a higher layer, and can be transmitted after a backoff performed after the medium becomes idle and after DIFS has elapsed. Additionally, a management frame is a frame for exchanging management information that is not forwarded to a higher layer, and is transmitted after a backoff performed after an IFS such as DIFS or Point Coordination Function IFS (PIFS). As subtype frames of the management frame, there are beacons, association request / response, re-association request / response, probe request / response, authentication request / response, 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 a control frame is not a response frame to a previous frame, it is transmitted after a backoff performed after DIFS has elapsed, and if it is a response frame to a previous frame, it is transmitted without performing a backoff after Short IFS (SIFS) has elapsed. The type and subtype of a frame can be identified by the type field and subtype field in the Frame Control (FC) field.

[0082] A Quality of Service (QoS) STA can perform a backoff performed after Arbitration IFS (AIFS) for the access category (AC) to which the frame belongs (i.e., AIFS (where i is a value determined by the AC)), and then can transmit the frame. Here, frames for which AIFS can be used can be data frames, management frames, or control frames other than response frames.

[0083] Figure 5 is a diagram for explaining the CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0084] As described above, in addition to the physical carrier sensing of the medium directly by the STA, the CSMA / CA mechanism also includes virtual carrier sensing. The virtual carrier sensing aims to compensate for problems such as the hidden node problem that may occur in medium access. For the 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 is available for the current STA using it or the STA having the right to use the medium. Therefore, the value set as the NAV corresponds to the period during which the STA transmitting the frame plans to use the medium, and during the corresponding period, the STA receiving the NAV value is prohibited from accessing the medium. For example, the NAV can be configured based on the value of the "Duration" field in the MAC header of the frame.

[0085] In Figure 5 the example, it is assumed that STA1 aims to send data to STA2, and STA3 is in a position where it can overhear some or all of the frames transmitted and received between STA1 and STA2.

[0086] To reduce the possibility of transmission conflicts of multiple STAs in the CSMA / CA-based frame transmission operation, a mechanism using RTS / CTS frames can be applied. In Figure 5 the example, when the transmission of STA1 is being executed, as a result of the carrier sensing of STA3, it can be determined that the medium is in an idle state. That is, STA1 can be a hidden node with respect to STA3. Alternatively, in Figure 5 the example, it can be determined that when the transmission of STA2 is being executed, the carrier sensing result of STA3 indicates that the medium is in an idle state. That is, STA2 can be a hidden node with respect to STA3. By exchanging RTS / CTS frames before performing data transmission and reception between STA1 and STA2, STAs outside the transmission range of either STA1 or STA2 or STAs outside the carrier sensing range of the transmission from STA1 or STA3 can refrain from attempting to occupy the channel during the data transmission and reception between STA1 and STA2.

[0087] Specifically, STA1 can determine whether the channel is being used 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 detected in the channel or signal correlation. Additionally, in terms of virtual carrier sensing, STA1 can use the Network Allocation Vector (NAV) timer to determine the channel occupancy state.

[0088] When the channel is in an idle state 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.

[0089] 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 transmission period of the frames continuously transmitted thereafter (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame). Alternatively, if STA3 can overhear the CTS frame from STA2, even though 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 transmission period of the frames continuously transmitted thereafter (e.g., SIFS + data frame + SIFS + ACK frame). That is, if STA3 can overhear one or more of the RTS frame or CTS frame 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 until the NAV timer expires.

[0090] When STA1 receives the CTS frame from STA2, STA1 can send a data frame to STA2 after SIFS 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 to STA1 after SIFS as a response to the data frame. When the NAV timer expires, STA3 can determine whether the channel is being used through carrier sensing. When STA3 determines during the DIFS period 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.

[0091] Figure 6 It is a diagram for explaining an example of the frame structure used in a WLAN system to which the present disclosure can be applied.

[0092] 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 to request the start of transmission, the PHY layer switches to the transmission mode, configures the information (e.g., data) provided by the MAC layer in the form of a frame, and transmits it. In addition, when the PHY layer detects the valid preamble of the received frame, the PHY layer monitors the header of the preamble and sends a command to the MAC layer notifying the start of reception by the PHY layer.

[0093] In this way, information transmission / reception in a wireless LAN system is performed in the form of frames, and for this purpose, a PHY layer protocol data unit (PPDU) format is defined.

[0094] A basic PPDU 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., the non-HT (High Throughput) shown in Figure 7 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.

[0095] The STF is a signal for signal detection, automatic gain control (AGC), diversity selection, precise time synchronization, etc., and the LTF is a signal for channel estimation and frequency error estimation. The STF and LTF can be referred to as signals for synchronization and channel estimation of the OFDM physical layer.

[0096] 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 can be determined based on the type of PPDU. For example, for non-HT, HT, VHT, or EHT PPDU, the value of the Length field can be determined to be a multiple of 3. For example, for HE PPDU, the value of the Length field can be determined to be a multiple of 3 + 1 or 3 + 2.

[0097] 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 predetermined units.

[0098] 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 may be composed of MAC PDUs and sent / received through the PSDU of the data part in the PPDU format.

[0099] The MAC header includes a Frame Control field, a Duration / ID field, an Address field, etc. The Frame Control field may include control information required for frame transmission / reception. The Duration / ID field may be set to the time for transmitting the corresponding frame, etc. For details of the Sequence Control, QoS Control, and HT Control sub-fields of the MAC header, refer to the IEEE 802.11 standard literature.

[0100] The Null Data PPDU (NDP) format refers to a PPDU format that does not include a data field. In other words, the NDP refers to a frame format that includes the PPDU preamble of the general PPDU format (i.e., the L-STF, L-LTF, L-SIG fields, and additional non-traditional SIG, non-traditional STF, non-traditional LTF (if any)) and does not include the remainder (i.e., the data field).

[0101] 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.

[0102] 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 may also be referred to as the non-HT PPDU format (as shown in (a) of Figure 7 ).

[0103] Compared with the basic PPDU format, the HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT fields. Figure 7The HT PPDU format shown in (b) of can be referred to as the HT mixed format. In addition, an HT greenfield format PPDU can be defined, and this corresponds to a format (not shown) consisting of an HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs, and a data field, excluding the L-STF, L-LTF, and L-SIG.

[0104] Compared with the basic PPDU format, an example of the VHT PPDU format (IEEE 802.11ac) additionally includes VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields (as Figure 7 shown in (c) of .

[0105] Compared with the basic PPDU format, an example of the HE PPDU format (IEEE 802.11ax) additionally includes a repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF, and packet extension (PE) fields (as Figure 7 shown in (d) of . Some fields can be excluded, or their lengths can vary according to the detailed example of the HE PPDU format. For example, the HE-SIG-B field is included in the HE PPDU format for multi-user (MU), and the HE-SIG-B is not included in the HE PPDU format for single-user (SU). In addition, the HE trigger-based (TB) PPDU format does not include the HE-SIG-B, and the length of the HE-STF field can vary up to 8 μs. The extended range (HE ER) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field can vary up to 16 μs. For example, the RL-SIG can be configured to be the same as the L-SIG. Based on the presence of the RL-SIG, the receiving STA can know that the received PPDU is an HE PPDU or an EHT PPDU, which will be described later.

[0106] The EHT PPDU format can include Figure 7 the EHT MU (multi-user) in (e) of and Figure 7 the EHT TB (trigger-based) PPDU in (f) of . The EHT PPDU format is similar to the HE PPDU format in including an RL-SIG following the L-SIG, but can include a U (universal)-SIG, EHT-SIG, EHT-STF, and EHT-LTF following the RL-SIG.

[0107] Figure 7The EHT MU PPDU in (e) corresponds to a PPDU carrying one or more data (or PSDU) for one or more users. That is, the EHT MU PPDU can be used for both SU transmission and MU transmission. For example, the EHT MU PPDU can correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0108] Compared with the EHT MU PPDU, Figure 7 the EHT TB PPDU in (f) omits the EHT-SIG. A STA that receives a trigger for UL MU transmission (e.g., a trigger frame or a triggered response schedule (TRS)) can perform UL transmission based on the EHT TB PPDU format.

[0109] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal Signal), EHT-SIG fields can be encoded and modulated so that even traditional 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 called pre-EHT modulation fields. Next, the EHT-STF, EHT-LTF, data, PE fields can be encoded and modulated to be demodulated and decoded by a STA that successfully decodes a non-traditional SIG (e.g., U-SIG and / or EHT-SIG) and obtains the information included in this field, and can be mapped based on the determined subcarrier frequency spacing (e.g., 78.125 kHz). These can be called EHT modulation fields.

[0110] 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 called pre-HE modulation fields, and the HE-STF, HE-LTF, data, and PE fields can be called HE modulation fields. Additionally, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields can be called non-VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and data fields can be called VHT modulation fields.

[0111] Included in Figure 7The U-SIG 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 μs, and the U-SIG can have a total duration of 8 μs. 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.

[0112] The U-SIG can be constructed in units of 20 MHz. For example, if an 80 MHz PPDU is constructed, the U-SIG can be replicated. That is, the same 4 U-SIGs can be included in the 80 MHz PPDU. A PPDU with a bandwidth exceeding 80 MHz can include different U-SIGs.

[0113] For example, A uncoded bits can be transmitted through the U-SIG. The first symbol of the U-SIG (e.g., the U-SIG-1 symbol) can transmit the first X bits of information out of a total of A bits of information, and the second symbol of the U-SIG (e.g., the U-SIG-2 symbol) can transmit the remaining Y bits of information out of a total of A bits of information. The A bits of information (e.g., 52 uncoded bits) 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 structure of the convolutional decoder and can be set to 0.

[0114] The bit information transmitted through the U-SIG can be divided into version-independent bits and version-dependent bits. For example, the U-SIG can be included in Figure 7 a new PPDU format not shown (e.g., the UHR PPDU format), and can be included in the format of the U-SIG field included in the EHT PPDU format and the format of the U-SIG field included in the UHR PPDU format. The version-independent bits can be the same, and some or all of the version-dependent bits can be different.

[0115] For example, the size of the version-independent bits of the U-SIG can be fixed or variable. The version-independent bits can be assigned only to the U-SIG-1 symbol, or assigned 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.

[0116] For example, the version-independent bits of the U-SIG may include 3 bits of physical layer version identifier (PHY version identifier), and this information may indicate the PHY version of the transmitted / received PPDU (e.g., EHT, UHR, etc.). The version-independent bits of the U-SIG may include a 1-bit UL / DL flag field. The first value of the 1-bit UL / DL flag field is related to UL communication, and the second value of the UL / DL flag field is related to DL communication. The version-independent bits of the U-SIG may include information about the length of the transmission opportunity (TXOP) and information about the BSS color ID.

[0117] For example, the version-related bits of the U-SIG may include information that directly or indirectly indicates the type of the PPDU (e.g., SU PPDU, MU PPDU, TB PPDU, etc.).

[0118] The information required for PPDU transmission and reception may be included in the U-SIG. For example, the U-SIG may also include information about the bandwidth, information about the MCS technology applied to non-traditional SIGs (e.g., EHT-SIG or UHR-SIG, etc.), information indicating whether the DCM (dual carrier modulation) technology (e.g., a technology for achieving an effect similar to frequency diversity by reusing the same signal on two subcarriers) is applied to non-traditional SIGs, information about the number of symbols for non-traditional SIGs, information about whether non-traditional SIGs are generated across the entire frequency band.

[0119] Some of the information required for PPDU transmission and reception may be included in the U-SIG and / or non-traditional SIGs (e.g., EHT-SIG or UHR-SIG, etc.). For example, information about the type of non-traditional LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information about the length of the non-traditional LTF and the CP (cyclic prefix) length, information about the GI (guard interval) applicable to the non-traditional LTF, information about the preamble punching applicable to the PPDU, information about the resource unit (RU) allocation, etc. may be included only in the U-SIG, included only in the non-traditional SIG, or may be indicated by a combination of the information included in the U-SIG and the information included in the non-traditional SIG.

[0120] Preamble punching may represent the transmission of the following PPDU, where there is no signal in one or more frequency units among the bandwidth of the PPDU. For example, the size of the frequency unit (or the resolution of the preamble punching) may be defined as 20 MHz, 40 MHz, etc. For example, preamble punching may be applied to a PPDU bandwidth of a predetermined size or larger.

[0121] In Figure 7In the example of, non - traditional SIGs such as HE - SIG - B and EHT - SIG can include control information for receiving STAs. The non - traditional SIG can be sent on at least one symbol, and one symbol can have a length of 4 μs. Information about the number of symbols for EHT - SIG can be included in a previous SIG (e.g., HE - SIG - A, U - SIG, etc.).

[0122] Non - traditional SIGs such as HE - SIG - B and EHT - SIG can include a common field and user - specific fields. The common field and user - specific fields can be encoded separately.

[0123] In some cases, the common field can be omitted. For example, in a compressed mode that does not apply OFDMA (Orthogonal Frequency Division Multiple Access), the common field can be omitted, and multiple STAs can receive a PPDU (e.g., the data field of the PPDU) through the same frequency band. In a non - compressed mode that applies OFDMA, multiple users can receive a PPDU (e.g., the data field of the PPDU) through different frequency bands.

[0124] 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.

[0125] The common field can include CRC bits and tail bits, and the length of the CRC bits can be determined to be 4 bits, while 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 positions of the RUs assigned to multiple users (i.e., multiple receiving STAs).

[0126] An RU can include multiple sub - carriers (or tones). When sending signals to multiple STAs based on OFDMA technology, RUs can be used. Additionally, even when sending signals to one STA, RUs can be defined. Resources can be allocated for non - traditional STF, non - traditional LTF, and data fields in units of RUs.

[0127] The RU of an applicable size can be defined according to the PPDU bandwidth. The RU can be defined identically or differently for the applied PPDU format (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.). For example, in the case of an 80 MHz PPDU, the RU layouts of the HE PPDU and the EHT PPDU can be different. The applicable RU size, the number of RUs, and the RU positions, the DC (direct current) subcarrier positions and number, the null subcarrier positions and number, the guard subcarrier positions and number, etc. for each PPDU bandwidth can be referred to as a tone plan. For example, the tone plan for high bandwidth can be defined in the form of multiple iterations of a low bandwidth tone plan.

[0128] 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 (multi-RU) is different from multiple individual RUs and corresponds to a group 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 constituting an MRU can be continuous or non-continuous in the frequency domain.

[0129] The specific size of an RU can be reduced or extended. Therefore, the specific size (i.e., the number of corresponding tones) of each RU in the present disclosure is illustrative rather than restrictive. Additionally, in the present disclosure, within a predetermined bandwidth (e.g., 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz...), the number of RUs can vary according to the RU size.

[0130] Figure 7 The name of each field in the PPDU format is exemplary, and the scope of the present disclosure is not limited by these names. Additionally, the examples of the present disclosure can be applied to Figure 7 the PPDU format shown in Figure 7 and new PPDU formats that exclude some fields and / or add some fields based on the

[0131] Resource Unit

[0132] Figures 8 to 10 is a diagram for illustrating an example of a resource unit of a WLAN system to which the present disclosure can be applied.

[0133] Refer to Figures 8 to 10, the resource unit (RU) defined in a wireless LAN system will be described. An RU may include multiple subcarriers (or tones). When transmitting signals to multiple STAs based on the OFDMA scheme, RUs can be used. Additionally, even when a signal is transmitted to a single STA, RUs can be defined. RUs can be used for the data field, STF, LTF, etc. of a PPDU.

[0134] As Figures 8 to 10 shown in, RUs corresponding to different numbers of tones (i.e., subcarriers) are used to construct some fields of 20 MHz, 40 MHz, or 80 MHz X-PPDU (X is HE, EHT, etc.). For example, resources can be allocated in RU units shown for the X-STF, X-LTF, and data field.

[0135] Figure 8 is a diagram illustrating an exemplary allocation of resource units (RUs) used in a 20 MHz frequency band.

[0136] As Figure 8 shown at the top of, a 26-unit (i.e., a unit corresponding to 26 tones) can be allocated. Six tones can be used as a guard band in the leftmost band of the 20 MHz frequency band, and five tones can be used as a guard band in the rightmost band of the 20 MHz frequency band. Additionally, seven DC tones are inserted into the center band (i.e., the DC band), and 26-units corresponding to each of the 13 tones can exist on the left and right sides of the DC band. Additionally, 26-units, 52-units, and 106-units can be allocated to other bands. Each unit can be allocated for an STA or a user.

[0137] Figure 8 The RU allocation of is used not only for the multi-user (MU) case but also for the single-user (SU) case, and in this case, one 242-unit can be used, as Figure 8 shown at the bottom of. In this case, three DC tones can be inserted.

[0138] In Figure 8 's example, various sizes of RUs are exemplified, that is, 26-RU, 52-RU, 106-RU, 242-RU, etc., but the specific sizes of these RUs can be reduced or enlarged. Therefore, in this disclosure, the specific size of each RU (i.e., the number of corresponding tones) is exemplary rather than restrictive. Additionally, within a predetermined bandwidth (e.g., 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz,...) in this disclosure, the number of RUs can vary according to the size of the RU. In what will be described below Figure 9 and / or Figure 10In the example of Figure 8 it is the same as the example of

[0139] Figure 9 is a diagram illustrating an exemplary allocation of resource units (RUs) used in a 40 MHz frequency band.

[0140] Just as various sizes of RUs are used in the example of Figure 8 it is also possible to use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. in the example of Figure 9 In addition, 5 DC tones can be inserted at the center frequency, 12 tones can be used as guard bands in the leftmost band of the 40 MHz frequency band, and 11 tones can be used as guard bands in the rightmost band of the 40 MHz frequency band.

[0141] In addition, as shown, when used for a single user, 484-RU can be used.

[0142] Figure 10 is a diagram illustrating an exemplary allocation of resource units (RUs) used in an 80 MHz frequency band.

[0143] Just as various sizes of RUs are used in the examples of Figure 8 and Figure 9 it is also possible to use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc. in the example of Figure 10 In addition, in the case of an 80 MHz PPDU, the RU allocation for HE PPDU and EHT PPDU can be different, and Figure 10 the example of Figure 10 shows an example of the RU allocation for an 80 MHz EHT PPDU. The scheme in the example of where 12 tones are used as guard bands in the leftmost band of the 80 MHz frequency band and 11 tones are used as guard bands in the rightmost band of the 80 MHz frequency band is the same as in HE PPDU and EHT PPDU. Different from the HE PPDU where 7 DC tones are inserted in the DC band and there is one 26-RU corresponding to each of the 13 tones on the left and right of the DC band, in the EHT PPDU, 23 DC tones are inserted in the DC band and there is one 26-RU on the left and right of the DC band. Different from the HE PPDU where one empty subcarrier exists between 242-RUs instead of in the center band, in the EHT PPDU there are five empty subcarriers. In the HE PPDU, one 484-RU does not include empty subcarriers, but in the EHT PPDU, one 484-RU includes 5 empty subcarriers.

[0144] In addition, as shown, when used for a single user, 996-RU can be used, and in this case, 5 DC tones are inserted, just like in HEPPDU and EHT PPDU.

[0145] In Figure 10 , the EHT PPDU on 160 MHz can be configured with multiple 80 MHz sub-blocks. The RU allocation for each 80 MHz sub-block can be the same as the RU allocation of the Figure 10 80 MHz EHT PPDU. If the 80 MHz sub-block of a 160 MHz or 320 MHz EHT PPDU is not punctured and the entire 80 MHz sub-block is used as part of an RU or multiple RUs (MRU), the 80 MHz sub-block can use the Figure 10 996-RU.

[0146] Here, an MRU corresponds to a set of subcarriers (or tones) composed of multiple RUs, and the multiple RUs that make up an MRU can be RUs of the same size or RUs of different sizes. For example, a single 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. Here, the multiple RUs that make up an MRU can correspond to small-size (e.g., 26, 52, or 106) RUs or large-size (e.g., 242, 484, or 996) RUs. That is, an MRU including both small-size RUs and large-size RUs may not be configured / defined. In addition, the multiple RUs that make up an MRU can be continuous or non-continuous in the frequency domain.

[0147] When the 80 MHz sub-block includes an RU with less than 996 tones or a part of the 80 MHz sub-block is punctured, the 80 MHz sub-block can use an RU allocation other than the 996-tone RU.

[0148] The RU of the present disclosure can be used for uplink (UL) and / or downlink (DL) communications. For example, when performing trigger-based UL-MU communication, the triggering STA (e.g., AP) can allocate a first RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a first STA and a second RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a second STA via trigger information (e.g., a trigger frame or a trigger response schedule (TRS)). Thereafter, the first STA can send a first trigger-based (TB) PPDU based on the first RU, and the second STA can send a second TB PPDU based on the second RU. The first / second TB PPDUs can be sent to the AP within the same time period.

[0149] For example, when configuring a DL MU PPDU, the STA (e.g., AP) sending the DL MU PPDU can allocate a first RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a first STA and a second RU (e.g., 26 / 52 / 106 / 242-RU, etc.) to a second STA. That is, the sending STA (e.g., AP) can send an X-STF (e.g., X represents HE, EHT, etc.), an X-LTF, and a data field for the first STA within one MU PPDU via the first RU, and can send an X-STF, an X-LTF, and a data field for the second STA via the second RU. Information regarding RU assignment can be signaled via the X-SIG (e.g., X represents HE, EHT, U) field in the X-PPDU format.

[0150] PPDU Transmission and Reception Method Based on Parameter Set Selection in a New Working Frequency Band

[0151] The above description of the wireless LAN system can be mainly applied to wireless LAN systems operating in an existing operating frequency band (e.g., a frequency band below 7 GHz, such as the 2.4 GHz, 5 GHz, or 6 GHz frequency band). For example, the above PPDU format can be mainly applied to wireless LAN systems operating in a frequency band below 7 GHz. Additionally, wireless LAN systems operating in a high operating frequency band (e.g., a millimeter wave (mmWave) frequency band, such as the 60 GHz frequency band) have been defined.

[0152] The present disclosure describes examples of a parameter set selection scheme that takes into account improving throughput and efficiency in the mmWave frequency band including the 60 GHz frequency band (i.e., not limited to the 60 GHz frequency band). Here, since the scope of the present disclosure relates to a parameter set selection scheme, the examples described below are not necessarily limited to being applied only to systems operating in mmWave, and the examples of the present disclosure can be equivalently applied to other operating frequency bands (e.g., a frequency band below 7 GHz).

[0153] Figure 11It is a diagram showing an example of a region where channelization of a millimeter wave (mmWave) band to which the present disclosure can be applied is shown.

[0154] Figure 11 The example in [ ] shows the mmWave bands used in the United States, the European Union, South Korea, Japan, Australia, and China, and shows the channel sizes and positions defined in these bands. For example, the bandwidth of each of the six channels can correspond to 2.16 GHz. In addition, when bandwidth bundling is applied, up to four unit bandwidths can be bundled to support a bandwidth of up to 8.64 GHz.

[0155] Additionally, in a wireless LAN system corresponding to a 1x parameter set (for example, a system based on IEEE 802.11ac (VHT)), the supported bandwidths are 20 MHz, 40 MHz, 80 MHz, and 160 MHz. For bandwidths of 20 MHz, 40 MHz, 80 MHz, and 160 MHz, the number of subcarriers is 64, 128, 256, and 512, respectively. In addition, a tone plan for the number and position of DC subcarriers, guard subcarriers, null subcarriers, and pilot subcarriers is also defined. Additionally, the subcarrier spacing is defined as 312.5 kHz, the OFDM symbol length excluding the CP (cyclic prefix) length is 3.2 μs, and the applicable guard intervals are 0.8 μs and 0.4 μs, respectively.

[0156] Referring to Figures 8 to 10 As described above, in a wireless LAN system corresponding to a 4x parameter set (for example, a system based on IEEE 802.11ax (HE) or IEEE 802.11be (EHT)), the supported bandwidths are 20 MHz, 40 MHz, 80 MHz, 160, and 320 MHz. For bandwidths of 20 MHz, 40 MHz, 80 MHz, 160, and 320 MHz, the number of subcarriers is 256, 512, 1024, 2048, and 4096, respectively. In addition, a RU / MRU tone plan for the number and position of DC subcarriers, guard subcarriers, null subcarriers, and pilot subcarriers is also defined. Additionally, the subcarrier spacing is defined as 78.125 kHz, the OFDM symbol length excluding the CP length is 12.8 μs, and the applicable guard intervals are 3.2 μs, 1.6 μs, and 0.8 μs.

[0157] Unlike these existing wireless LAN systems, technologies such as UHR being discussed are considering using frequency bands below 7 GHz (e.g., 2.4 GHz, 5 GHz, or 6 GHz bands) and / or mmWave bands (e.g., 60 GHz band) to achieve high data rates and low latency. For example, for specific use cases that require high throughput, it may be difficult to meet the requirements using only the currently defined channel bandwidth, so it may be considered to send / receive a specific PPDU via the mmWave band. In this case, a method for selecting a parameter set to be applied when sending / receiving a PPDU in the mmWave band needs to be newly defined / configured.

[0158] Basically, a PPDU sent in the mmWave band can be defined using a preamble and a data field. Here, regarding the preamble, an existing traditional preamble may or may not exist, and if it does not exist, it can have a simple structure of STF, LTF, SIG, and data.

[0159] In the mmWave band, bandwidth and tone plan, etc. can be configured by applying frequency up-conversion to the above 1x parameter set and / or 4x parameter set. That is, a new parameter set in the mmWave band can be defined based on an N-fold frequency up-conversion relationship with the existing 1x parameter set or 4x parameter set. Here, N can correspond to values such as 4, 8, or 10.

[0160] Specifically, when applying N-fold frequency up-conversion in the mmWave band, the bandwidth can be the existing bandwidth * N, the number of subcarriers is the same as the number of subcarriers in the existing bandwidth, the subcarrier spacing can be the existing subcarrier spacing * N, and the symbol length (symbol duration) can be the existing symbol length / N.

[0161] For example, a new parameter set based on the existing 1x parameter set (e.g., the 1x parameter set in IEEE 802.11ac) can include: a bandwidth of one of 20 * N, 40 * N, 80 * N, or 160 * N MHz; a subcarrier spacing of 312.5 * N kHz; a number of subcarriers of one of 64, 128, 256, or 512; the OFDM symbol length excluding the guard interval (or CP length) can be defined as 3.2 / N μs. Here, candidate values for the guard interval can be defined as 0.8 / N μs and 0.4 / N μs. Additionally, the 160 * N MHz tone plan can be defined using a 2-fold repetition of a 160 * 2N MHz bandwidth (i.e., 1024 subcarriers) or a 4-fold repetition of a 160 * 4N MHz bandwidth (i.e., 2048 subcarriers).

[0162] For example, a new parameter set based on an existing 4x parameter set (e.g., the 4x parameter set in IEEE 802.11ax / 11be) can have: a bandwidth of one of 20*N, 40*N, 80*N, 160*N, 320*N MHz; a subcarrier spacing of 78.125*N kHz; a number of subcarriers of one of 256, 512, 1024, 2048, or 4096; the OFDM symbol length excluding the guard interval (or CP length) can be defined as 12.8 / N μs. Here, candidate values for the guard interval can be defined as 0.8 / N μs, 1.6 / N, and 3.2 / N μs. Additionally, the bandwidth of 320*2N MHz (i.e., 8192 subcarriers) can be defined using two repetitions of the 320*N MHz tone plan.

[0163] When upscaling the above 1x parameter set or 4x parameter set, in terms of complexity, applying N-fold upscaling to 80 MHz or 160 MHz of the 1x parameter set may be the same as applying 4N-fold upscaling to 20 MHz or 40 MHz of the 4x parameter set (e.g., if the complexity of the upscaling itself is removed).

[0164] For example, for a new parameter set based on the 1x parameter set, an 80*N MHz or 160*N MHz bandwidth, 256 or 512 fast Fourier transforms (FFTs), a 312.5*N kHz subcarrier spacing, and a 0.8 / N μs or 0.4 / N μs guard interval can be configured. Additionally, for a new parameter set based on the 4x parameter set, a 20*4N MHz or 40*4N MHz bandwidth, 256 or 512 FFTs, a 78.125*4N kHz subcarrier spacing, a 3.2 / (4*N) μs, 1.6 / (4*N) μs, or 0.8 / (4*N) μs guard interval can be configured. That is, except for the upscaling factor and one guard interval (i.e., 0.8 / (4*N) μs), they are the same in most aspects.

[0165] However, if one or two bandwidths are defined in the actual mmWave band, considering complexity, upscaling can be applied to the 20 MHz or 40 MHz bandwidth based on the 1x parameter set instead of the 80 MHz or 160 MHz bandwidth. In this case, considering complexity, due to applying a 4-fold larger upscaling, the complexity difference may not be significant compared to applying upscaling in the 80 MHz or 160 MHz bandwidth.

[0166] That is, in terms of complexity and / or inter-carrier interference (ICI), the scheme based on the 1x parameter set may always have an advantage. For example, in the case where the same 4N-fold upscaling is applied to both the 1x parameter set and the 4x parameter set, the FFT size of the scheme based on the 1x parameter set is smaller than the FFT size of the scheme based on the 4x parameter set.

[0167] On the other hand, a solution based on a 4x parameter set may have advantages in terms of throughput and / or inter-symbol interference (ISI). For example, compared with a solution based on a 1x parameter set, the number of available subcarriers in a solution based on a 4x parameter set is slightly increased, and the symbol length is longer.

[0168] Additionally or alternatively, in the same case where one or two bandwidths are defined in the mmWave band, when upsampling is applied based on a 1x parameter set, it can be considered that there is no significant difference in complexity between applying 4N times upsampling to a 20 MHz or 40 MHz bandwidth and applying N times upsampling to an 80 MHz or 160 MHz bandwidth. For example, it can be considered that although the complexity increases due to the increase in the FFT size, the increase in complexity is offset by the upsampling factor itself which is reduced.

[0169] Considering these points, a method of applying upsampling to an 80 MHz or 160 MHz bandwidth based on a 1x parameter set can be considered to improve throughput. In this case, the method based on a 4x parameter set has advantages in terms of guard interval and OFDMA transmission, while the method based on a 1x parameter set has advantages when considering the complexity of the upsampling itself. However, in this case, it is necessary to implement a 160 MHz bandwidth based on a 1x parameter set.

[0170] That is, when only one or two bandwidths are defined in the mmWave band, when performing PPDU transmission in the mmWave band, a method of selecting one of the 1x parameter set or the 4x parameter set and performing the corresponding PPDU transmission can be applied by considering the advantages of the 1x parameter set or the 4x parameter set.

[0171] For example, when considering OFMDA transmission (where a small guard interval value needs to be considered) and / or cases where a 160 MHz bandwidth is not implemented for the 1x parameter set, etc., the PPDU in the mmWave band can be configured by applying 4N times upsampling to a 20 MHz or 40 MHz bandwidth based on a 4x parameter set.

[0172] For another example, considering non-OFDMA transmission and / or considering low upsampling complexity, the PPDU (hereinafter referred to as mmWave PPDU) in the mmWave band can be configured by applying N times upsampling to an 80 MHz or 160 MHz bandwidth based on a 1x parameter set.

[0173] An indication related to the above method in the present disclosure can be directly indicated in the SIG field within the mmWave PPDU. Alternatively, it can be indicated within a control frame or the like, thereby defining a control frame for supporting the mmWave band below 7 GHz.

[0174] In this regard, the indication of bandwidth and guard interval may be mandatory. In addition, for mmWave PPDUs based on 4x parameter sets with OFDMA applied, the indication of OFDMA-related indications and RU / MRU allocation information may be mandatory.

[0175] That is, the indication for distinguishing between the method based on the 1x parameter set and the method based on the 4x parameter set can be directly executed, and alternatively, the instruction for distinguishing between the method based on the 1x parameter set and the method based on the 4x parameter set can also be indirectly executed through indications such as bandwidth, guard interval, OFDMA, etc.

[0176] If the indication for distinguishing between the 1x parameter set-based scheme and the 4x parameter set-based scheme corresponds to an explicit indication, the content composition may vary depending on the 1x parameter set or the 4x parameter set. For example, in the case of the 1x parameter set-based scheme, since there are two guard interval candidate values, only 1 bit is used for this, and the OFDMA indication may not be required. On the other hand, in the case of the 4x parameter set-based scheme, since there are three guard interval candidate values, 2 bits are used for this, the OFDMA indication must be included, and when OFDMA is used, the RU / MRU allocation indication must be included. Such a method may be reasonable when considering overhead, etc.

[0177] Alternatively, if an explicit indication is provided to distinguish whether the scheme is based on the 1x parameter set or the 4x parameter set, the content configuration may be the same regardless of the 1x parameter set and the 4x parameter set. For example, considering a 4x parameter set-based scheme with 3 guard interval candidate values, 2 bits are configured for the guard interval indication, and a field for the OFDMA indication must be included. In this case, if the 1x parameter set-based scheme is applied, the OFDMA-related information is not indicated, and the field for the RU / MRU allocation indication is only defined when OFDMA is used. Such a scheme may be efficient in terms of implementation.

[0178] On the other hand, if the indication for distinguishing between the 1x parameter set-based scheme and the 4x parameter set-based scheme corresponds to an implicit indication, considering that the 4x parameter set-based scheme has 3 guard interval candidate values, the guard interval indication information may always consist of 2 bits. In addition, the field for the OFDMA indication can be mandatory, and when OFDMA is used, the field for the RU / MRU allocation indication can also always be defined.

[0179] Additionally or alternatively, regarding the up-conversion for PPDU transmission / reception based on the 1x parameter set and / or 4x parameter set in the above mmWave band, at least one of the following Schemes 1 to 3 can be considered.

[0180] (Method 1)

[0181] In the mmWave band, a method of applying 4N times upsampling to 20 MHz and / or 40 MHz based on a 4x parameter set can be applied.

[0182] For example, in a basic mmWave transmission, the bandwidth can be defined as configured by applying N times upsampling to 20 MHz, 40 MHz, 80 MHz, or 160 MHz based on a 1x parameter set. In this case, if certain conditions are met (e.g., if 160 MHz based on a 1x parameter set is not implemented, if gains such as guard intervals are considered), then applying N times upsampling to 80 MHz or 160 MHz based on a 1x parameter set can be replaced by applying N times upsampling to 20 MHz and / or 40 MHz based on a 4x parameter set.

[0183] The indication information related thereto (e.g., the differentiation indication based on a 1x parameter set or a 4x parameter set, the bandwidth indication, the guard interval indication, the OFDMA indication, the RU / MRU allocation indication, etc.) can be executed based on the above methods in the present disclosure.

[0184] In addition to the above bandwidth, a wider bandwidth can be configured by applying 4N times upsampling to 80 MHz, 160 MHz, or 320 MHz (or a part of 80 MHz, 160 MHz, or 320 MHz) based on a 4x parameter set.

[0185] (Method 2)

[0186] In the mmWave band, a method of configuring the bandwidth by simultaneously considering the upsampling application based on a 1x parameter set and the upsampling application based on a 4x parameter set can be applied.

[0187] For example, in mmWave transmission, a specific bandwidth can be configured by applying N times upsampling to 20 MHz or 40 MHz based on a 1x parameter set, and a wider bandwidth can be configured by applying 4N times upsampling to 20 MHz or 40 MHz based on a 4x parameter set.

[0188] In addition to the above bandwidth, a wider bandwidth can be configured by applying 4N times upsampling to 80 MHz, 160 MHz, or 320 MHz (or a part of 80 MHz, 160 MHz, or 320 MHz) based on a 4x parameter set.

[0189] In this regard, in addition to the two smaller bandwidths, more diverse guard intervals and OFDMA applications can be implemented.

[0190] (Method 3)

[0191] In the mmWave band, a method of configuring bandwidth can be applied that simultaneously considers the up - frequency application based on the 1x parameter set and the up - frequency application based on the 4x parameter set.

[0192] For example, in mmWave transmission, a specific bandwidth can be configured by applying N - fold up - frequency to 20 MHz, 40 MHz, or 80 MHz based on the 1x parameter set, and a wider bandwidth can be configured by applying 4N - fold up - frequency to 40 MHz based on the 4x parameter set.

[0193] In addition to the above - mentioned bandwidths, a wider bandwidth can be configured by applying 4N - fold up - frequency to 80 MHz, 160 MHz, or 320 MHz (or a part of 80 MHz, 160 MHz, or 320 MHz) based on the 4x parameter set.

[0194] Considering the mandatory bandwidth (up to 80 MHz) based on the 1x parameter set, it may have an advantage in terms of complexity compared to the examples in Method 2 above.

[0195] In the above - mentioned configuration method of the present disclosure, the method of performing the relevant information indication may be similar to the above - mentioned method of the present disclosure, but it may not require an indication for distinguishing between the 1x parameter set and the 4x parameter set. This is because according to the bandwidth indication, it can be distinguished whether it is a method based on the 1x parameter set or a method based on the 4x parameter set.

[0196] In this regard, as described above in the present disclosure, depending on whether it is based on the 1x parameter set or the 4x parameter set, the content included in the PPDU can be configured differently, or regardless of whether it is based on the 1x parameter set or the 4x parameter set, the content included in the PPDU can be configured identically.

[0197] The following will refer to Figure 12 and Figure 13 to describe the operation of the STA according to the above - mentioned embodiments of the present disclosure. That is, Figure 12 and Figure 13 The examples of

[0198] Figure 12 Illustrate the operation flowchart of the first STA according to the embodiments of the present disclosure.

[0199] The first STA can receive a PPDU (S1210) from the second STA that includes information indicating one of a plurality of bandwidth candidates.

[0200] Here, the operating frequency band for transmitting or receiving the corresponding PPDU may be the mmWave band or the 60 GHz band.

[0201] In this regard, multiple bandwidth candidates can be defined as being configured substantially by applying a first upscaling factor to a first group of bandwidth candidates. Additionally, based on predefined criteria, at least one of the multiple bandwidth candidates (i.e., some of the bandwidth candidates) can be defined as being configured by applying a second upscaling factor to a second group of bandwidth candidates instead of applying the first upscaling factor. That is, if certain criteria / conditions are met (e.g., whether a 160 MHz bandwidth based on a 1x parameter set is achieved, the gain of the guard interval, etc.), a method of applying different multiples of upscaling to the bandwidth based on different parameter sets can be applied.

[0202] For example, the first group of bandwidth candidates can correspond to bandwidth candidates based on a 1x parameter set, and the second group of bandwidth candidates can correspond to bandwidth candidates based on a 4x parameter set.

[0203] Here, the first upscaling factor can be set to the value N, and the second upscaling factor can be set to the value 4*N. That is, the first upscaling factor can be a value for applying N-fold upscaling, and the second upscaling factor can be a value for applying 4*N-fold upscaling.

[0204] As a specific example, the first group of bandwidth candidates can include at least one of 20 MHz, 40 MHz, 80 MHz, or 160 MHz. At this time, the bandwidth candidates configured by applying the first upscaling factor to the first group of bandwidth candidates can be at least one of 20*N MHz, 40*N MHz, 80*N MHz, or 160*N MHz. In this regard, for the bandwidth candidates configured by applying the first upscaling factor to the first group of bandwidth candidates, the subcarrier spacing can be 312.5*N kHz, the number of subcarriers can be one of 64, 128, 256, or 512, and the orthogonal frequency division multiplexing (OFDM) symbol length excluding the cyclic prefix (CP) length can be 3.2 / N μs.

[0205] As a specific example, the second group of bandwidth candidates can include at least one of 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 320 MHz. At this time, the bandwidth candidates configured by applying the second upscaling factor to the second group of bandwidth candidates can be at least one of 20*4*N MHz, 40*4*N MHz, 80*4*N MHz, 160*4*N MHz, or 320*4*N MHz. In this regard, for the bandwidth candidates configured by applying the second upscaling factor to the second group of bandwidth candidates, the subcarrier spacing can be 78.125*N kHz, the number of subcarriers can be one of 256, 512, 1024, 2048, or 4096, and the OFDM symbol length excluding the CP length can be 12.8 / N μs.

[0206] As a specific example, the first bandwidth candidate group may include at least one of 20 MHz, 40 MHz, 80 MHz, or 160 MHz, and the second bandwidth candidate group may include at least one of 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 320 MHz. In this case, when the above predefined criteria are met, the multiple bandwidth candidates in step S1210 may be configured as 20*N MHz, 40*N MHz, 20*4*N MHz, and 40*4*N MHz. That is, some of the multiple bandwidth candidates may be configured by applying N-fold upsampling to 20 MHz and 40 MHz based on the 1x parameter set, and the remainder may be configured by applying 4*N-fold upsampling to 20 MHz and 40 MHz based on the 4x parameter set.

[0207] The first STA may process the PPDU in the bandwidth indicated by the information in step S1210 (S1220).

[0208] For example, processing the PPDU may include obtaining the information contained in each field of the received PPDU based on one of various predefined PPDU formats (e.g., mmWave PPDU, etc.).

[0209] Regarding the above PPDU transmission / reception based on parameter set selection in the present disclosure, the signal (SIG) field in the corresponding PPDU may include information indicating whether the bandwidth in step S1210 is based on the first bandwidth candidate or the second bandwidth candidate. If the information indicates that it is based on the first bandwidth candidate (e.g., indicated by the 1x parameter set scheme), the corresponding PPDU may include 1-bit guard interval indication information. On the other hand, if the information indicates that it is based on the second bandwidth candidate (e.g., indicated by the 4x parameter set scheme), the corresponding PPDU may include 2-bit guard interval indication information and OFDMA indication information. Additionally or alternatively, regardless of the information, the corresponding PPDU may include 2-bit guard interval indication information and OFDMA indication information. Here, if the OFDMA indication information indicates the use of OFDMA, the corresponding PPDU may further include RU / MRU allocation indication information.

[0210] In Figure 12 the example described, the method performed by the first STA may be performed by Figure 1 the first device (100). For example, Figure 1One or more processors (102) of the first device (100) may be configured to receive, via one or more transceivers (106), a PPDU from a second STA (200) that includes information indicating one of a plurality of bandwidths, and perform PPDU processing in the bandwidth indicated by the information. Additionally, one or more memories (104) of the first device (100) may store instructions that, when executed by one or more processors (102), are used to perform Figure 12 the methods described in the examples or the following examples.

[0211] Figure 13 Illustrates an operation flowchart of a second STA according to an embodiment of the present disclosure.

[0212] The second STA may construct a PPDU that includes information indicating one of a plurality of bandwidth candidates (S1310).

[0213] Here, the operating band for transmitting or receiving the corresponding PPDU may be a mmWave band or a 60 GHz band.

[0214] In this regard, the plurality of bandwidth candidates may be defined as being configured substantially by applying a first frequency scaling factor to a first bandwidth candidate group. Additionally, based on predefined criteria, at least one of the plurality of bandwidth candidates (i.e., some of the bandwidth candidates) may be defined as being configured by applying a second frequency scaling factor to a second bandwidth candidate group, rather than applying the first frequency scaling factor. That is, if certain criteria / conditions are met (e.g., whether a 160 MHz bandwidth based on a 1x parameter set is achieved, the gain of the guard interval, etc.), a method of applying different multiples of frequency scaling to the bandwidth based on different parameter sets may be applied.

[0215] The second STA may send the PPDU to the first STA in the bandwidth indicated by the information in step S1310 (S1320).

[0216] In Figure 13 the example, the indication / interpretation of the bandwidth candidates, bandwidth candidate groups, frequency scaling elements, etc. is the same as that described in Figure 12 the example, so redundant descriptions are omitted.

[0217] Figure 13 The method performed by the second STA described in the example may be performed by Figure 1 the second device (200). For example, Figure 1One or more processors (202) of the second device (200) may be configured to construct a PPDU including a field indicating the bandwidth for the first STA, and transmit the configured PPDU to the first STA (100) via one or more transceivers (206). In addition, one or more memories (204) of the second device (200) may store commands for performing the methods described in the examples or the following examples when executed by one or more processors (202). Figure 13 The commands of the methods described in the examples or the following examples.

[0218] In existing wireless LAN systems, the specific details of configuring bandwidth in the mmWave band are not defined. In this regard, the method proposed by the present disclosure relates to a method of configuring bandwidth by applying a frequency multiplication factor to existing parameter sets (e.g., 1x parameter set, 4x parameter set). In particular, the method proposed by the present disclosure has the new feature of configuring bandwidth candidates based on different parameter sets and different frequency multiplication applications according to certain criteria / conditions. According to the method proposed by the present disclosure, new effects of improving throughput and / or efficiency can be achieved in a newly defined operating band (e.g., mmWave band, etc.).

[0219] 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 may 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 may be included in other embodiments, or may be replaced by corresponding elements or features of other embodiments. Obviously, the embodiments may include combining claims that do not have an explicit citation relationship in the claims, or may be included as new claims through amendment after the application is filed.

[0220] It is clear to those skilled in the relevant art 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 disclosure 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 disclosure.

[0221] 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 enable the software or instructions, etc. to be stored and executable in the device or computer. The 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 a computer-readable storage medium, and the features described in the present disclosure can be implemented by using a computer program product including such a storage medium. The storage medium can include high-speed random access memory, for example, DRAM, SRAM, DDR RAM, or other random access solid-state storage devices, but is not limited thereto, and it can include non-volatile memory, for example, 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.

[0222] Industrial Applicability

[0223] The method proposed by the present disclosure is mainly described based on examples applied to IEEE 802.11-based systems, but can be applied to various WLAN 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 the steps of: Receiving, from a second STA, a physical layer protocol data unit PPDU including information indicating one of a plurality of bandwidth candidates; And Processing the PPDU in the bandwidth indicated by the information, Wherein the plurality of bandwidth candidates are defined by applying a first frequency scaling factor to a first group of bandwidth candidates, and Wherein, based on a predefined criterion, at least one of the plurality of bandwidth candidates is defined by applying a second frequency scaling factor to a second group of bandwidth candidates instead of applying the first frequency scaling factor.

2. The method according to claim 1, Among them, The first frequency scaling element is set to the value N, and the second frequency scaling element is set to the value 4*N.

3. The method according to claim 2, Among them, The first group of bandwidth candidates includes at least one of 20 MHz, 40 MHz, 80 MHz or 160 MHz, and Wherein the bandwidth candidates configured by applying the first frequency scaling factor to the first group of bandwidth candidates are at least one of 20*N MHz, 40*N MHz, 80*N MHz or 160*N MHz.

4. The method according to claim 3, Among them, For the bandwidth candidates configured by applying the first frequency scaling factor to the first group of bandwidth candidates, The subcarrier spacing is 312.5*N kHz, The number of subcarriers is one of 64, 128, 256 or 512, and The length of the orthogonal frequency division multiplexing OFDM symbol without including the cyclic prefix CP length is 3.2 / N us.

5. The method according to claim 2, Among them, The second group of bandwidth candidates includes at least one of 20 MHz, 40 MHz, 80 MHz, 160 MHz or 320 MHz, and Wherein the bandwidth candidates configured by applying the second frequency scaling factor to the second group of bandwidth candidates are at least one of 20*4*N MHz, 40*4*N MHz, 80*4*N MHz, 160*4*N MHz or 320*4*N MHz.

6. The method according to claim 5, Among them, For the bandwidth candidates configured by applying the second frequency scaling factor to the second group of bandwidth candidates, The subcarrier spacing is 78.125*N kHz, The number of subcarriers is one of 256, 512, 1024, 2048 or 4096, and The length of the OFDM symbol without including the CP length is 12.8 / N us.

7. The method according to claim 2, Among them, The first group of bandwidth candidates includes at least one of 20 MHz, 40 MHz, 80 MHz or 160 MHz, Wherein the second group of bandwidth candidates includes at least one of 20 MHz, 40 MHz, 80 MHz, 160 MHz or 320 MHz, and, Wherein, based on the predefined criterion, the plurality of bandwidth candidates are configured as 20*N MHz, 40*N MHz, 20*4*N MHz and 40*4*N MHz.

8. The method according to claim 7, Among them, The predefined criterion is related to at least one of the implementation for 160 MHz in the first bandwidth candidate group or the gain of the guard interval.

9. The method according to claim 1, Among them, The SIG field in the PPDU includes information indicating whether the bandwidth is based on the first bandwidth candidate or the second bandwidth candidate, wherein, based on the information indicating that the bandwidth is based on the first bandwidth candidate, the PPDU includes 1-bit guard interval indication information, and wherein, based on the information indicating that the bandwidth is based on the second bandwidth candidate, the PPDU includes 2-bit guard interval indication information and orthogonal frequency division multiple access (OFDMA) indication information.

10. The method according to claim 1, Among them, The SIG field in the PPDU includes information indicating whether the bandwidth is based on the first bandwidth candidate or the second bandwidth candidate, and wherein, regardless of the information, the PPDU includes 2-bit guard interval indication information and OFDMA indication information.

11. The method according to claim 1, Among them, The operating frequency band for transmitting or receiving the PPDU is a millimeter wave (mmWave) band or a 60 GHz band.

12. A device for a first station (STA) in a wireless local area network (WLAN) system, the device 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: Receive, from a second STA, a physical layer protocol data unit (PPDU) including information indicating one of a plurality of bandwidth candidates; and Process the PPDU in the bandwidth indicated by the information, wherein the plurality of bandwidth candidates are defined by applying a first frequency up-conversion factor to a first bandwidth candidate group, and wherein, based on a predefined criterion, at least one of the plurality of bandwidth candidates is defined by applying a second frequency up-conversion factor to a second bandwidth candidate group instead of applying the first frequency up-conversion factor.

13. A method performed by a second station (STA) in a wireless LAN system, the method comprising the steps of: Construct a physical layer protocol data unit (PPDU) including information indicating one of a plurality of bandwidth candidates; And Transmit the PPDU to a first STA in the bandwidth indicated by the information, wherein the plurality of bandwidth candidates are defined by applying a first frequency up-conversion factor to a first bandwidth candidate group, and wherein, based on a predefined criterion, at least one of the plurality of bandwidth candidates is defined by applying a second frequency up-conversion factor to a second bandwidth candidate group instead of applying the first frequency up-conversion factor.

14. A device for a second station (STA) in a wireless local area network (WLAN) system, the device 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: Construct a physical layer protocol data unit (PPDU) including information indicating one of a plurality of bandwidth candidates; and Transmit the PPDU to a first STA in a bandwidth indicated by the information, wherein the plurality of bandwidth candidates are defined as being configured by applying a first frequency scaling factor to a first group of bandwidth candidates, and wherein, based on a predefined criterion, at least one of the plurality of bandwidth candidates is defined as being configured by applying a second frequency scaling factor to a second group of bandwidth candidates instead of applying the first frequency scaling factor.

15. A processing unit configured to control a station STA in a wireless local area network WLAN system, the processing unit comprising: at least one processor; and at least one computer memory, the at least one computer memory being operatively connected to the at least one processor and storing, when executed by the at least one processor, instructions for performing the method according to any one of claims 1 to 11.

16. At least one non-transitory computer-readable medium storing at least one instruction, wherein the at least one instruction, when executed by at least one processor, controls a device in a wireless local area network WLAN system to perform the method according to any one of claims 1 to 11.

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