Method and device for transmission or reception based on distributed resource unit tone plan in wireless LAN system

Abstract

A method and a device for transmission or reception based on a distributed resource unit (DRU) tone plan in a wireless LAN system are disclosed. The method according to one embodiment of the present disclosure may comprise steps in which a first station (STA): receives, from a second STA, a trigger frame including at least one field for allocating a DRU; and transmitting, to the second STA, a trigger-based (TB) physical layer protocol data unit (PPDU) in response to the trigger frame. Here, the at least one field can indicate information about a DRU index based on the location of a channel in which the DRU is distributed and a tone plan.

Description

Method and device for transmitting or receiving based on a distributed resource unit tone plan in a wireless LAN system

[0001] The present disclosure relates to a method and device for transmitting or receiving based on a distributed resource unit tone plan in a wireless local area network (WLAN) system.

[0002] New technologies have been introduced for wireless local area networks (WLANs) to improve transmission rates, increase bandwidth, enhance reliability, reduce errors, and reduce latency. Among WLAN technologies, the IEEE (Institute of Electrical and Electronics Engineers) 802.11 series of standards can be referred to as Wi-Fi. For example, recently introduced technologies for WLANs include enhancements for Very High Throughput (VHT) in the 802.11ac standard and enhancements for High Efficiency (HE) in 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), which supports increased bandwidth, efficient utilization of multiple bands, and increased spatial streams, and for coordination of multiple access points (APs), are being studied. In particular, various technologies are being studied to support low latency or real-time traffic. Furthermore, new technologies are being discussed to support ultra-high reliability (UHR), including improvements or extensions of EHT technology.

[0004] The technical problem of the present disclosure is to provide a method and device for transmitting or receiving based on a distributed resource unit tone plan in a wireless LAN system.

[0005] The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

[0006] A method according to one aspect of the present disclosure may include: receiving, by a first station (STA), a trigger frame from a second STA, the trigger frame including at least one field for allocating a distributed resource unit (DRU); and transmitting, by the first STA, a trigger-based (TB) physical layer protocol data unit (PPDU) to the second STA in response to the trigger frame. Here, the at least one field may indicate information about a DRU index based on a location and tone plan of a channel on which the DRU is distributed.

[0007] A method according to an additional aspect of the present disclosure may include: transmitting, by a second station (STA), to a first STA, a trigger frame comprising at least one field for distributed resource unit (DRU) allocation; and receiving, by the second STA, a trigger-based (TB) physical layer protocol data unit (PPDU) from the first STA in response to the trigger frame. Here, the at least one field may indicate information about a DRU index based on a location and tone plan of a channel on which the DRU is distributed.

[0008] According to the present disclosure, a method and device for transmitting or receiving based on a distributed resource unit tone plan in a wireless LAN system can be provided.

[0009] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0010] The accompanying drawings, which are incorporated in and are part of the detailed description to aid in understanding the present disclosure, provide embodiments of the present disclosure and, together with the detailed description, describe the technical features of the present disclosure.

[0011] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0012] FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0013] FIG. 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

[0014] FIG. 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0015] FIG. 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0016] FIG. 6 is a drawing for explaining an example of a frame structure used in a wireless LAN system to which the present disclosure can be applied.

[0017] FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0018] FIG. 8 is a diagram illustrating an example of a resource unit of a wireless LAN system to which the present disclosure can be applied.

[0019] FIG. 9 is a diagram illustrating another example of a resource unit of a wireless LAN system to which the present disclosure can be applied.

[0020] FIG. 10 is a diagram illustrating another example of a resource unit of a wireless LAN system to which the present disclosure can be applied.

[0021] FIG. 11 is a drawing illustrating examples of DRUs to which the present disclosure can be applied.

[0022] FIG. 12 is a drawing showing an exemplary format of a trigger frame to which the present disclosure can be applied.

[0023] FIG. 13 is a diagram for explaining an example of an operation by a first STA in a PPDU transmission and reception method based on a DRU tone plan according to the present disclosure.

[0024] FIG. 14 is a diagram for explaining an example of an operation by a second STA in a PPDU transmission and reception method based on a DRU tone plan according to the present disclosure.

[0025] FIG. 15 is a diagram for explaining a PPDU transmission and reception procedure between a transmitting STA and a receiving STA according to one embodiment of the present disclosure.

[0026] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description set forth below, together with the accompanying drawings, is intended to explain exemplary embodiments of the present disclosure and is not intended to represent the only embodiments in which the present disclosure may be practiced. The following detailed description includes specific details to provide a thorough understanding of the present disclosure. However, one of ordinary skill in the art will appreciate that the present disclosure may be practiced without these specific details.

[0027] In some cases, to avoid obscuring the concepts of the present disclosure, known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device.

[0028] In the present disclosure, when a component is said to be "connected," "coupled," or "connected" to another component, this may include not only a direct connection but also an indirect connection in which another component exists between them. Furthermore, the terms "comprises" or "has" in the present disclosure specify the presence of the mentioned features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0029] In this disclosure, terms such as “first,” “second,” etc. are used only to distinguish one component from another and are not used to limit the components, and do not limit the order or importance between the components unless specifically stated otherwise. Accordingly, within the scope of this disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

[0030] The terminology used herein is for the purpose of describing particular embodiments and is not intended to limit the scope of the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. The term "and / or" as used herein may refer to any one of the associated enumerated items, or is meant to refer to and encompass any and all possible combinations of two or more of them. Furthermore, the use of " / " between words in this disclosure has the same meaning as "and / or" unless otherwise stated.

[0031] The examples of the present disclosure can be applied to various wireless communication systems. For example, the examples of the present disclosure can be applied to a wireless LAN system. For example, the examples of the present disclosure can be applied to a wireless LAN based on the IEEE 802.11a / g / n / ac / ax / be standards. Furthermore, the examples of the present disclosure can be applied to a wireless LAN based on the newly proposed IEEE 802.11bn (or UHR) standard. Additionally, the examples of the present disclosure can be applied to a wireless LAN based on the next-generation standard after IEEE 802.11bn. Furthermore, the examples of the present disclosure can be applied to a cellular wireless communication system. For example, the examples of the present disclosure can be applied to a cellular wireless communication system based on the LTE (Long Term Evolution) series of technologies and the 5G NR (New Radio) series of technologies of the 3rd Generation Partnership Project (3GPP) standard.

[0032] Below, technical features to which examples of the present disclosure can be applied are described.

[0033] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0034] The first device (100) and the second device (200) illustrated in FIG. 1 may be replaced with various terms such as a terminal, a wireless device, a WTRU (Wireless Transmit Receive Unit), a UE (User Equipment), an MS (Mobile Station), a UT (user terminal), an MSS (Mobile Subscriber Station), an MSS (Mobile Subscriber Unit), an SS (Subscriber Station), an AMS (Advanced Mobile Station), a WT (Wireless terminal), or simply a user. In addition, the first device (100) and the second device (200) may be replaced with various terms such as an access point (AP), a BS (Base Station), a fixed station, a Node B, a BTS (Base Transceiver System), a network, an AI (Artificial Intelligence) system, an RSU (road side unit), a repeater, a router, a relay, a gateway, etc.

[0035] The devices (100, 200) illustrated in FIG. 1 may also be referred to as stations (STAs). For example, the devices (100, 200) illustrated in FIG. 1 may be referred to by various terms such as transmitting device, receiving device, transmitting STA, and receiving STA. For example, the STAs (110, 200) may perform an AP (access point) role or a non-AP role. That is, in the present disclosure, the STAs (110, 200) may perform the functions of an AP and / or a non-AP. When the STAs (110, 200) perform an AP function, they may simply be referred to as APs, and when the STAs (110, 200) perform a non-AP function, they may simply be referred to as STAs. In addition, in the present disclosure, the APs may also be referred to as AP STAs.

[0036] Referring to FIG. 1, the first device (100) and the second device (200) can transmit and receive wireless signals through various wireless LAN technologies (e.g., IEEE 802.11 series). The first device (100) and the second device (200) can include interfaces for a medium access control (MAC) layer and a physical layer (PHY) that follow the provisions of the IEEE 802.11 standard.

[0037] In addition, 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.) other than wireless LAN technology. In addition, the device of the present disclosure may be implemented as various devices such as a mobile phone, a vehicle, a personal computer, an AR (Augmented Reality) device, a VR (Virtual Reality) device, etc. In addition, the STA of the present specification may support various communication services such as voice calls, video calls, data communications, autonomous driving, MTC (Machine-Type Communication), M2M (Machine-to-Machine), D2D (Device-to-Device), and IoT (Internet-of-Things).

[0038] A first device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. For example, the processor (102) may process information in the memories (104) to generate first information / signals, and then transmit a wireless signal including the first information / signals via the transceivers (106). Furthermore, the processor (102) may receive a wireless signal including second information / signals via the transceivers (106), and then store information obtained from 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 perform some or all of the processes controlled by the processor (102), or may store software code including instructions for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in the present disclosure. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals via one or more antennas (108). The transceiver (106) may include a transmitter and / or a receiver. The transceiver (106) may be used interchangeably with an RF (Radio Frequency) unit. In the present disclosure, a device may also mean a communication modem / circuit / chip.

[0039] The second device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from 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 perform some or all of the processes controlled by the processor (202), or may store software code including instructions for performing the descriptions, functions, procedures, proposals, methods, and / or operation flowcharts disclosed in the present disclosure. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and / or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present disclosure, a device may also mean a communication modem / circuit / chip.

[0040] Hereinafter, the hardware elements of the device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, proposals and / or methods disclosed in the present disclosure, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, proposals, methods and / or operational flowcharts disclosed in the present disclosure.

[0041] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, proposals, methods and / or operation flowcharts disclosed in this disclosure may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods and / or operation flowcharts disclosed in this disclosure may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0042] One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. The one or more memories (104, 204) may be configured as ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. The one or more memories (104, 204) may be located internally and / or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

[0043] One or more transceivers (106, 206) can transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or flowcharts of the present disclosure, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or flowcharts of the present disclosure, from one or more other devices. For example, one or more transceivers (106, 206) can be coupled to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit 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 coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in this disclosure, via 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) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0044] For example, one of the STAs (100, 200) may perform the intended operation of an AP, and the other of the STAs (100, 200) may perform the intended operation of a non-AP STA. For example, the transceivers (106, 206) of FIG. 1 may perform transmission and reception operations of signals (e.g., packets or PPDUs (Physical layer Protocol Data Units) according to IEEE 802.11a / b / g / n / ac / ax / be / bn, etc.). In addition, in the present disclosure, operations in which various STAs generate transmission and reception signals or perform data processing or calculations in advance for transmission and reception signals may be performed in the processors (102, 202) of FIG. 1. For example, an example of an operation for generating a transmission / reception signal or performing data processing or operation in advance for a transmission / reception signal may include 1) an operation for determining / obtaining / configuring / computing / decoding / encoding bit information of a field (SIG (signal), STF (short training field), LTF (long training field), Data, etc.) included in a PPDU, 2) an operation for determining / configuring / obtaining time resources or frequency resources (e.g., subcarrier resources) used for a field (SIG, STF, LTF, Data, etc.) included in a PPDU, 3) an operation for determining / configuring / obtaining a specific sequence (e.g., a pilot sequence, an STF / LTF sequence, an extra sequence applied to SIG) used for a field (SIG, STF, LTF, Data, etc.) included in a PPDU, 4) a power control operation and / or a power saving operation applied to an STA, 5) an operation related to determining / obtaining / configuring / computing / decoding / encoding an ACK signal, etc. Additionally, in the examples below, various information (e.g., information related to fields / subfields / control fields / parameters / power, etc.) used by various STAs for determining / acquiring / configuring / computing / decoding / encoding transmission / reception signals can be stored in the memory (104, 204) of FIG. 1.

[0045] Hereinafter, downlink (DL) refers to a link for communication from an AP STA to a non-AP STA, and downlink PPDUs / packets / signals, etc. can be transmitted and received through the downlink. In downlink communication, the transmitter may be part of an AP STA, and the receiver may be part of a non-AP STA. Uplink (UL) refers to a link for communication from a non-AP STA to an AP STA, and uplink PPDUs / packets / signals, etc. can be transmitted and received through the uplink. In uplink communication, the transmitter may be part of a non-AP STA, and the receiver may be part of an AP STA.

[0046] FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0047] The structure of a wireless LAN system can be composed of multiple components. Through the interaction of multiple components, a wireless LAN that supports transparent STA mobility to the upper layer can be provided. A Basic Service Set (BSS) corresponds to a basic building block of a wireless LAN. FIG. 2 illustrates, by way of example, the existence of two BSSs (BSS1 and BSS2) and the inclusion of two STAs as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). The oval representing a BSS in FIG. 2 can also be understood as representing a coverage area in which STAs included in the corresponding BSS maintain communication. This area can be referred to as a Basic Service Area (BSA). When an STA moves outside of a BSA, it cannot directly communicate with other STAs within the BSA.

[0048] If we do not consider the DS illustrated in Figure 2, the most basic type of BSS in a wireless LAN is an Independent BSS (IBSS). For example, an IBSS can have a minimal form consisting of only two STAs. For example, assuming other components are omitted, BSS1 consisting of only STA1 and STA2, or BSS2 consisting of only STA3 and STA4, can be representative examples of an IBSS, respectively. Such a configuration is possible when the STAs can communicate directly without an AP. Furthermore, in this type of WLAN, a LAN can be configured when needed rather than being planned in advance, and this can be called an ad-hoc network. Since an IBSS does not include an AP, there is no centralized management entity. That is, in an IBSS, STAs are managed in a distributed manner. In IBSS, all STAs can be mobile STAs, and access to distributed systems (DS) is not permitted, forming a self-contained network.

[0049] An STA's membership in a BSS can dynamically change, for example, when an STA is turned on or off, or when an STA enters or leaves a BSS area. To become a member of a BSS, an STA can join the BSS using a synchronization process. To access all services in the BSS infrastructure, an STA must be associated with the BSS. This association can be dynamically established and may involve the use of a Distribution System Service (DSS).

[0050] In a wireless LAN, the direct STA-to-STA distance can be limited by PHY performance. While this distance limit may be sufficient in some cases, communication between STAs over longer distances may be required in other cases. To support extended coverage, a distributed system (DS) can be configured.

[0051] DS refers to a structure in which BSSs are interconnected. Specifically, a BSS may exist as an extended component of a network composed of multiple BSSs, as illustrated in Figure 2. DS is a logical concept and can be specified by the characteristics of a distributed system medium (DSM). In this regard, the Wireless Medium (WM) and DSM can be logically distinguished. Each logical medium is used for a different purpose and by different components. These media are neither limited to being identical nor limited to being different. This logical difference between multiple media explains the flexibility of the WLAN architecture (DS architecture or other network architectures). In other words, the WLAN architecture can be implemented in various ways, and the physical characteristics of each implementation can independently specify the WLAN architecture.

[0052] A DS can support mobile devices by providing seamless integration of multiple BSSs and the logical services necessary to handle addresses to destinations. Additionally, a DS may further include a component called a portal, which acts as a bridge for connecting wireless LANs to other networks (e.g., IEEE 802.X).

[0053] An AP is an entity that enables access to a DS through a WM for associated non-AP STAs and also has the functionality of an STA. Data movement between a BSS and a DS can be performed through an AP. For example, STA2 and STA3 illustrated in FIG. 2 have the functionality of an STA and provide the function of allowing associated non-AP STAs (STA1 and STA4) to access the DS. In addition, since all APs are basically STAs, all APs are addressable entities. The address used by an AP for communication on a WM and the address used by an AP for communication on a DSM do not necessarily have to be the same. A BSS consisting of an AP and one or more STAs can be referred to as an infrastructure BSS.

[0054] Data transmitted from one of the STA(s) associated with an AP to the STA address of that AP may always be received on an uncontrolled port and processed by an IEEE 802.1X port access entity. In addition, if the controlled port is authenticated, the transmitted data (or frame) may be forwarded to the DS.

[0055] In addition to the structure of the DS described above, an extended service set (ESS) may be established to provide wider coverage.

[0056] An ESS is a network of arbitrary size and complexity, consisting of DSs and BSSs. An ESS may correspond to a set of BSSs connected to a DS. However, an ESS does not include a DS. An ESS network is characterized by appearing as an IBSS at the Logical Link Control (LLC) layer. STAs within an ESS can communicate with each other, and mobile STAs can move from one BSS to another (within the same ESS) transparently to the LLC. APs within an ESS may have the same SSID (service set identification). The SSID is distinct from the BSSID, which is the identifier of the BSS.

[0057] In a wireless LAN system, no assumptions are made about the relative physical locations of BSSs, and all of the following configurations are possible: BSSs can be partially overlapping, which is commonly used to provide continuous coverage. BSSs can also be physically disconnected, and there is no logical distance limit between them. BSSs can also be physically co-located, which can be used to provide redundancy. Furthermore, one (or more) IBSS or ESS networks can physically co-exist with one (or more) ESS networks. This can occur in cases where an ad-hoc network operates at the same location as an ESS network, where physically overlapping wireless networks are configured by different organizations, or where two or more different access and security policies are required at the same location.

[0058] FIG. 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

[0059] For an STA to set up a link and transmit and receive data on a network, it must first discover the network, perform authentication, establish an association, and complete security authentication procedures. The link setup process can also be referred to as the session initiation process or session setup process. Furthermore, the discovery, authentication, association, and security setup processes of the link setup process can be collectively referred to as the association process.

[0060] In step S310, the STA may perform a network discovery operation. This network discovery operation may include scanning operations by the STA. That is, for the STA to access a network, it must search for available networks. Before joining a wireless network, the STA must identify compatible networks. The process of identifying networks in a specific area is called scanning.

[0061] Scanning methods include active scanning and passive scanning. Figure 3 illustrates a network discovery operation including an active scanning process as an example. In active scanning, an STA performing scanning transmits a probe request frame to discover any APs in the vicinity while moving between channels and waits for a response. The responder transmits a probe response frame in response to the STA that transmitted the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame in the BSS of the channel being scanned. In the BSS, the AP transmits the beacon frame, so the AP becomes the responder. In the IBSS, the STAs within the IBSS take turns transmitting beacon frames, so the responder is not fixed. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 can store BSS-related information included in the received probe response frame and move to the next channel (e.g., channel 2) to perform scanning (i.e., transmitting and receiving probe requests / responses on channel 2) in the same manner.

[0062] Although not shown in Figure 3, the scanning operation can also be performed in a passive scanning manner. In passive scanning, the STA performing the scanning moves between channels and waits for a beacon frame. A beacon frame is one of the management frames defined in IEEE 802.11. It announces the existence of a wireless network and is periodically transmitted so that the STA performing the scanning can find the wireless network and participate in the wireless network. In the BSS, the AP performs the role of periodically transmitting the beacon frame, and in the IBSS, the STAs within the IBSS take turns transmitting the beacon frame. When the STA performing the scanning receives a beacon frame, it stores the information about the BSS included in the beacon frame and moves to another channel, recording the beacon frame information on each channel. The STA receiving the beacon frame stores the BSS-related information included in the received beacon frame and moves to the next channel to perform scanning on the next channel in the same manner. Comparing active scanning and passive scanning, active scanning has the advantage of lower delay and power consumption than passive scanning.

[0063] After the STA discovers the network, an authentication process may be performed in step S320. This authentication process may be referred to as the first authentication process to clearly distinguish it from the security setup operation of step S340 described below.

[0064] The authentication process involves the STA sending an authentication request frame to the AP, and the AP responding by sending an authentication response frame to the STA. The authentication frame used for the authentication request / response corresponds to a management frame.

[0065] The authentication frame may include information such as 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. These are just some examples of information that may be included in an authentication request / response frame, and may be replaced with other information or include additional information.

[0066] An STA can send an authentication request frame to an AP. The AP can determine whether to grant authentication to the STA based on the information contained in the received authentication request frame. The AP can provide the result of the authentication process to the STA via an authentication response frame.

[0067] After the STA is successfully authenticated, an association process may be performed in step S330. The association process includes a process in which the STA transmits an association request frame to the AP, and in response, the AP transmits an association response frame to the STA.

[0068] For example, the association request frame may include information about various capabilities, a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, RSN, a mobility domain, supported operating classes, a Traffic Indication Map Broadcast request, interworking service capabilities, etc. For example, the association response frame may include information about 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 Indicator (RSNI), a mobility domain, a timeout interval (e.g., an association comeback time), overlapping BSS scan parameters, a TIM broadcast response, a Quality of Service (QoS) map, etc. These are just some examples of information that may be included in a combined request / response frame, and may be replaced by other information or include additional information.

[0069] After the STA successfully joins the network, a security setup process may be performed in step S340. The security setup process in step S340 may be referred to as an authentication process through a Robust Security Network Association (RSNA) request / response, the authentication process in step S320 may be referred to as a first authentication process, and the security setup process in step S340 may also be referred to simply as an authentication process.

[0070] The security setup process of step S340 may include, for example, a process of establishing a private key through a four-way handshaking using an Extensible Authentication Protocol over LAN (EAPOL) frame. Furthermore, the security setup process may be performed according to a security method not defined in the IEEE 802.11 standard.

[0071] FIG. 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0072] In wireless LAN systems, the basic access mechanism of MAC (Medium Access Control) is Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA). The CSMA / CA mechanism, also known as the Distributed Coordination Function (DCF) of the IEEE 802.11 MAC, essentially employs a "listen before talk" access mechanism. According to this type of access mechanism, the AP and / or STA may perform a Clear Channel Assessment (CCA) to sense the wireless channel or medium for a predetermined time period (e.g., a DCF Inter-Frame Space (DIFS)) before starting transmission. If the sensing result determines that the medium is in an idle state, the AP and / or STA may start transmitting frames through the medium. On the other hand, if the medium is detected to be occupied or busy, the AP and / or STA may not start its own transmission, but may wait for a delay period (e.g., a random backoff period) for medium access before attempting to transmit frames. By applying a random backoff period, multiple STAs are expected to attempt to transmit frames after waiting for different periods of time, thereby minimizing collisions.

[0073] In addition, the IEEE 802.11 MAC protocol provides the 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 that periodically polls all receiving APs and / or STAs to ensure that they receive data frames. In addition, the HCF has the Enhanced Distributed Channel Access (EDCA) and the HCF Controlled Channel Access (HCCA). The EDCA is a contention-based access method for a provider to provide data frames to multiple users, while the HCCA uses a non-contention-based channel access method that utilizes a polling mechanism. In addition, the HCF includes a medium access mechanism to improve the Quality of Service (QoS) of the wireless LAN, and can transmit QoS data in both the Contention Period (CP) and the Contention Free Period (CFP).

[0074] Referring to Fig. 4, an operation based on a random backoff period is described. When a medium that was occupied / busy changes to an idle state, multiple STAs can attempt to transmit data (or frames). To minimize collisions, each STA can select a random backoff count, wait for the corresponding slot time, and then attempt transmission. The random backoff count has a pseudo-random integer value and can be determined as one of the values ​​in the range of 0 to CW. Here, CW is a contention window parameter value. The CW parameter is given an initial value of CWmin, but can take a doubled value in case of transmission failure (e.g., when an ACK for a transmitted frame is not received). When the CW parameter value becomes CWmax, data transmission can be attempted while maintaining the CWmax value until data transmission is successful, and if data transmission is successful, it is reset to the CWmin value. The CW, CWmin, and CWmax values ​​are 2. n It is desirable to set it to -1 (n=0, 1, 2, ...).

[0075] Once the random backoff process begins, the STA continues to monitor the medium while counting down the backoff slots according to the determined backoff count value. If the medium is monitored as occupied, the countdown stops and waits. When the medium becomes idle, the remaining countdown resumes.

[0076] In the example of FIG. 4, when a packet to be transmitted reaches the MAC of STA3, STA3 can immediately transmit a frame if it confirms that the medium is idle for DIFS. The remaining STAs monitor the medium for occupied / busy states and wait. In the meantime, data to be transmitted may also occur in each of STA1, STA2, and STA5, and each STA can count down the backoff slot according to a random backoff count value selected by each STA after waiting for DIFS if the medium is monitored as idle. Assume that STA2 selects the smallest backoff count value and STA1 selects the largest backoff count value. In other words, this example shows a case where the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1 when STA2 finishes the backoff count and starts frame transmission. STA1 and STA5 briefly stop counting down and wait while STA2 occupies the medium. When STA2's occupation ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and then resume the backoff count that they had stopped. That is, they can start transmitting frames after counting down the remaining backoff slots equal to the remaining backoff time. Since STA5's remaining backoff time is shorter than STA1's, STA5 starts transmitting frames. While STA2 occupies the medium, STA4 may also have data to transmit. From STA4's perspective, when the medium becomes idle, it waits for DIFS, counts down according to its selected random backoff count value, and then starts transmitting frames. In the example of Figure 4, the remaining backoff time of STA5 coincidentally matches the random backoff count value of STA4, in which case a collision may occur between STA4 and STA5. If a collision occurs, neither STA4 nor STA5 will receive an ACK, resulting in a failure in data transmission.In this case, STA4 and STA5 can select a random backoff count value and perform a countdown after doubling the CW value. STA1 waits while the medium is occupied by transmissions from STA4 and STA5, and when the medium becomes idle, it waits for DIFS and can start transmitting frames after the remaining backoff time elapses.

[0077] As in the example of Fig. 4, a data frame is a frame used for transmitting data forwarded to a higher layer, and can be transmitted after a backoff performed after DIFS elapses from when the medium becomes idle. Additionally, a management frame is a frame used for exchanging management information that is not forwarded to a higher layer, and is transmitted after a backoff performed after an IFS elapses, such as DIFS or PIFS (Point coordination function IFS). Subtype frames of a management frame include a beacon, an association request / response, a re-association request / response, a probe request / response, and an authentication request / response. A control frame is a frame used to control access to the medium. The subtype frames of the control frame include 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), and Trigger. If the control frame is not a response frame to the previous frame, it is transmitted after a backoff performed after the DIFS (Direct Inverse Frame Stop) has elapsed, and if it is a response frame to the previous frame, it is transmitted without a backoff performed after the SIFS (short IFS). The type and subtype of the frame can be identified by the type field and subtype field in the Frame Control (FC) field.

[0078] A QoS (Quality of Service) STA can transmit a frame after a backoff performed after the AIFS (arbitration IFS) for the access category (AC) to which the frame belongs, i.e., AIFS[i] (where i is a value determined by the AC), has elapsed. Here, the frames for which AIFS[i] can be used can be data frames, management frames, and also control frames that are not response frames.

[0079] FIG. 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0080] As mentioned above, the CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing, in which STAs directly sense the medium. Virtual carrier sensing is intended to address potential issues in medium access, such as the hidden node problem. For virtual carrier sensing, the MAC of an STA can utilize a Network Allocation Vector (NAV). The NAV is a value that an STA that is currently using or has the right to use the medium indicates to other STAs the remaining time until the medium becomes available. Therefore, the value set as NAV corresponds to the period during which the STA transmitting the frame is scheduled to use the medium, and an STA receiving the NAV value is prohibited from accessing the medium during that period. For example, the NAV can be set based on the value of the "duration" field in the MAC header of the frame.

[0081] In the example of FIG. 5, it is assumed that STA1 wants to transmit data to STA2, and STA3 is in a position to overhear some or all of the frames transmitted and received between STA1 and STA2.

[0082] In order to reduce the possibility of collisions in transmissions of multiple STAs in a CSMA / CA-based frame transmission operation, a mechanism using RTS / CTS frames may be applied. In the example of FIG. 5, while STA1 is transmitting, STA3 may determine that the medium is idle based on carrier sensing results. That is, STA1 may correspond to a hidden node for STA3. Alternatively, in the example of FIG. 5, while STA2 is transmitting, STA3 may determine that the medium is idle based on carrier sensing results. That is, STA2 may correspond to a hidden node for 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 for transmissions from STA1 or STA3, may not attempt to occupy the channel during data transmission and reception between STA1 and STA2.

[0083] Specifically, STA1 can determine whether a channel is occupied through carrier sensing. In terms of physical carrier sensing, STA1 can determine channel occupancy idleness based on the energy level or signal correlation detected in the channel. Furthermore, in terms of virtual carrier sensing, STA1 can determine the channel occupancy status using a network allocation vector (NAV) timer.

[0084] STA1 can transmit an RTS frame to STA2 after performing a backoff if the channel is idle during the DIFS. STA2 can transmit a CTS frame, which is a response to the RTS frame, to STA1 after an SIFS if it receives the RTS frame.

[0085] If STA3 cannot overhear a CTS frame from STA2 but can overhear an RTS frame from STA1, STA3 can use the duration information contained in the RTS frame to set a NAV timer for the subsequent consecutively transmitted frame transmission period (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame). Alternatively, if STA3 cannot overhear an RTS frame from STA1 but can overhear a CTS frame from STA2, STA3 can use the duration information contained in the CTS frame to set a NAV timer for the subsequent consecutively transmitted frame transmission period (e.g., SIFS + data frame + SIFS + ACK frame). That is, if STA3 can overhear one or more of the RTS or CTS frames from one or more of STA1 or STA2, it can set a NAV accordingly. If STA3 receives a new frame before the NAV timer expires, it can update the NAV timer using the duration information contained in the new frame. STA3 does not attempt channel access until the NAV timer expires.

[0086] If STA1 receives a CTS frame from STA2, it can transmit a data frame to STA2 after SIFS from the time when the CTS frame is completely received. If STA2 successfully receives the data frame, it can transmit an ACK frame in response to the data frame to STA1 after SIFS. STA3 can determine whether the channel is in use through carrier sensing if the NAV timer expires. If STA3 determines that the channel is not in use by another terminal during the DIFS after the NAV timer expires, it can attempt channel access after a contention window (CW) based on a random backoff has elapsed.

[0087] FIG. 6 is a drawing for explaining an example of a frame structure used in a wireless LAN system to which the present disclosure can be applied.

[0088] The PHY layer can prepare an MPDU (MAC PDU) to be transmitted based on an instruction or primitive (meaning a set of instructions or parameters) from the MAC layer. For example, when a command requesting the start of transmission of the PHY layer is received from the MAC layer, the PHY layer can switch to transmission mode and transmit the information (e.g., data) provided by the MAC layer in the form of a frame. In addition, when the PHY layer detects a valid preamble of the received frame, it monitors the header of the preamble and sends a command to the MAC layer notifying the start of reception of the PHY layer.

[0089] In this way, information transmission / reception in a wireless LAN system is done in the form of frames, and for this purpose, the PHY layer Protocol Data Unit (PPDU) format is defined.

[0090] 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 (e.g., non-HT (High Throughput) as illustrated in FIG. 7) PPDU format may consist of only the Legacy-STF (L-STF), Legacy-LTF (L-LTF), Legacy-SIG (L-SIG) fields, 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 field, non-legacy STF, non-legacy LTF, (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)) may be included between the L-SIG field and the data field. More specific details will be described later with reference to FIG. 7.

[0091] STF is a signal for signal detection, AGC (Automatic Gain Control), diversity selection, and precise time synchronization, while LTF is a signal for channel estimation, frequency error estimation, etc. STF and LTF can be said to be signals for synchronization and channel estimation of the OFDM physical layer.

[0092] The SIG field may include various information related to PPDU transmission and reception. For example, the L-SIG field may consist of 24 bits and 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 data. For example, the 12-bit Length field may include information about the length or time duration of the PPDU. For example, the value of the 12-bit Length field may be determined based on the type of the PPDU. For example, for a non-HT, HT, VHT, or EHT PPDU, the value of the Length field may be determined as a multiple of 3. For example, for HE PPDU, the value of the Length field can be determined as a multiple of 3 + 1 or a multiple of 3 + 2.

[0093] The data field may include a SERVICE field, a Physical layer Service Data Unit (PSDU), a PPDU TAIL bit, and, if necessary, padding bits. Some bits of the SERVICE field may be used to synchronize the descrambler at the receiving end. The PSDU corresponds to a MAC PDU defined at the MAC layer and may contain data generated / used by upper layers. The PPDU TAIL bit may be used to return the encoder to a 0 state. The padding bit may be used to adjust the length of the data field to a predetermined unit.

[0094] MAC PDUs are defined according to various MAC frame formats, and a basic MAC frame consists of a MAC header, a frame body, and a Frame Check Sequence (FCS). A MAC frame is composed of MAC PDUs and can be transmitted / received through the PSDU in the data portion of the PPDU format.

[0095] The MAC header includes a Frame Control field, a Duration / ID field, an Address field, etc. The Frame Control field may include control information required for frame transmission / reception. The Duration / ID field may be set to a time for transmitting the corresponding frame, etc. The Address subfields may indicate the receiver address, transmitter address, destination address, and source address of the frame, and some Address subfields may be omitted. For specific details of each subfield of the MAC header, including the Sequence Control, QoS Control, and HT Control subfields, refer to the IEEE 802.11 standard document.

[0096] The Null-Data PPDU (NDP) format refers to a PPDU format that does not include a data field. In other words, NDP refers to a frame format that includes a PPDU preamble (i.e., L-STF, L-LTF, L-SIG fields, and, if additionally present, non-legacy SIG, non-legacy STF, and non-legacy LTF) in the general PPDU format, and does not include the remaining part (i.e., data field).

[0097] FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0098] Standards such as IEEE 802.11a / g / n / ac / ax use various PPDU formats. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and Data fields. The basic PPDU format can also be referred to as the non-HT PPDU format (Fig. 7(a)).

[0099] The HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT(s) fields in addition to the basic PPDU format. The HT PPDU format illustrated in Fig. 7(b) may be referred to as an HT-mixed format. Additionally, an HT-greenfield format PPDU may be defined, which corresponds to a format that does not include L-STF, L-LTF, and L-SIG, but consists of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTF, and Data fields (not illustrated).

[0100] An example of the VHT PPDU format (IEEE 802.11ac) includes VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields in addition to the basic PPDU format (Fig. 7(c)).

[0101] An example of a HE PPDU format (IEEE 802.11ax) additionally includes RL-SIG (Repeated L-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), and PE (Packet Extension) fields in addition to the basic PPDU format (Fig. 7(d)). Depending on specific examples of the HE PPDU format, some fields may be excluded or their lengths may vary. For example, the HE-SIG-B field is included in the HE PPDU format for multi-users (MUs), but the HE-SIG-B is not included in the HE PPDU format for single users (SUs). In addition, the HE trigger-based (TB) PPDU format does not include the HE-SIG-B, and the length of the HE-STF field may vary to 8 microseconds (us). The HE ER (Extended Range) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field can vary to 16us. For example, the RL-SIG can be configured identically to the L-SIG. The receiving STA can determine that the received PPDU is a HE PPDU or an EHT PPDU, described later, based on the presence of the RL-SIG.

[0102] The EHT PPDU format may include the EHT MU (multi-user) PPDU of FIG. 7(e) and the EHT TB (trigger-based) PPDU of FIG. 7(f). The EHT PPDU format is similar to the HE PPDU format in that it includes an RL-SIG following an L-SIG, but may include a U (universal)-SIG, an EHT-SIG, an EHT-STF, and an EHT-LTF following the RL-SIG.

[0103] The EHT MU PPDU in FIG. 7(e) corresponds to a PPDU that carries one or more data (or PSDUs) 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.

[0104] The EHT TB PPDU of Fig. 7(f) omits the EHT-SIG compared to the EHT MU PPDU. An STA that has received a trigger for UL MU transmission (e.g., a trigger frame or TRS (triggered response scheduling)) can perform UL transmission based on the EHT TB PPDU format.

[0105] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal SIGNAL), and EHT-SIG fields can be encoded and modulated so that even legacy STAs can attempt demodulation and decoding, and can be mapped based on a predetermined subcarrier frequency interval (e.g., 312.5 kHz). These can be referred to as pre-EHT modulated fields. Next, the EHT-STF, EHT-LTF, Data, and PE fields can be encoded and modulated so that they can be demodulated and decoded by an STA that has successfully decoded a non-legacy SIG (e.g., U-SIG and / or EHT-SIG) and obtained the information contained in the corresponding field, and can be mapped based on a predetermined subcarrier frequency interval (e.g., 78.125 kHz). These can be referred to as EHT modulated fields.

[0106] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields may be referred to as pre-HE modulation fields, and the HE-STF, HE-LTF, Data, and PE fields may be referred to as HE modulation fields. Additionally, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields may be referred to as pre-VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and Data fields may be referred to as VHT modulation fields.

[0107] The U-SIG included in the EHT PPDU format of FIG. 7 can be configured based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG can have a duration of 4 us, and the U-SIG can have a total duration of 8 us. Each symbol of the U-SIG can be used to transmit 26 bits of information. For example, each symbol of the U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0108] U-SIGs can be configured in 20MHz units. For example, when an 80MHz PPDU is configured, the same U-SIG can be duplicated in 20MHz units. That is, four identical U-SIGs can be included in an 80MHz PPDU. When the bandwidth exceeds 80MHz, for example, for a 160MHz PPDU, the U-SIGs in the first 80MHz unit and the U-SIGs in the second 80MHz unit can be different.

[0109] For example, A uncoded bits may be transmitted via U-SIG, and a first symbol of U-SIG (e.g., a U-SIG-1 symbol) may transmit the first X bits of information out of a total A bits of information, and a second symbol of U-SIG (e.g., a U-SIG-2 symbol) may transmit the remaining Y bits of information out of a total A bits of information. The A bits of information (e.g., 52 uncoded bits) may include a CRC field (e.g., a field of 4 bits in length) and a tail field (e.g., a field of 6 bits in length). The tail field may be used to terminate the trellis of the convolutional decoder and may be set to 0, for example.

[0110] The A bit information transmitted by U-SIG can be divided into version-independent bits and version-dependent bits. For example, U-SIG can be included in a new PPDU format (e.g., UHR PPDU format) not shown in FIG. 7, and in the format of the U-SIG field included in the EHT PPDU format and the format of the U-SIG field included in the UHR PPDU format, the version-independent bits can be the same, and some or all of the version-dependent bits can be different.

[0111] For example, the size of the version-independent bits of U-SIG can be fixed or variable. The version-independent bits can be assigned only to U-SIG-1 symbols, or to both U-SIG-1 symbols and U-SIG-2 symbols. The version-independent bits and the version-dependent bits can be called by various names, such as the first control bit and the second control bit.

[0112] For example, the version-independent bits of the U-SIG may include a 3-bit PHY version identifier, which may indicate the PHY version (e.g., EHT, UHR, etc.) of the transmitted and received PPDUs. 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 relates to UL communication, and the second value of the UL / DL flag field relates to DL communication. The version-independent bits of the U-SIG may include information about the length of a transmission opportunity (TXOP) and information about a BSS color ID.

[0113] For example, the version-dependent bits of the U-SIG may contain information that directly or indirectly indicates the type of PPDU (e.g., SU PPDU, MU PPDU, TB PPDU, etc.).

[0114] Information required for PPDU transmission and reception may be included in the U-SIG. For example, the U-SIG may further include information about bandwidth, information about the MCS technique applied to the non-legacy SIG (e.g., EHT-SIG or UHR-SIG), information indicating whether a dual carrier modulation (DCM) technique (e.g., a technique to achieve an effect similar to frequency diversity by reusing the same signal on two subcarriers) is applied to the non-legacy SIG, information about the number of symbols used for the non-legacy SIG, information about whether the non-legacy SIG is generated across the entire band, etc.

[0115] Some of the information required for transmitting and receiving a PPDU may be included in the U-SIG and / or the non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.). For example, information about the type of the non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information about the length of the non-legacy LTF and the cyclic prefix (CP) length, information about the guard interval (GI) applicable to the non-legacy LTF, information about preamble puncturing applicable to the PPDU, information about resource unit (RU) allocation, etc. may be included only in the U-SIG, may be included only in the non-legacy SIG, or may be indicated by a combination of the information included in the U-SIG and the information included in the non-legacy SIG.

[0116] Preamble puncturing may refer to the transmission of a PPDU in which no signal is present in one or more frequency units within the PPDU's bandwidth. For example, the size of the frequency unit (or the resolution of the preamble puncturing) may be defined as 20 MHz, 40 MHz, etc. For example, preamble puncturing may be applied to a PPDU bandwidth greater than a certain size.

[0117] In the example of FIG. 7, non-legacy SIGs such as HE-SIG-B and EHT-SIG may include control information for the receiving STA. The non-legacy SIG may be transmitted over at least one symbol, and each symbol may have a length of 4 us. Information regarding the number of symbols used for the EHT-SIG may be included in a previous SIG (e.g., HE-SIG-A, U-SIG, etc.).

[0118] Non-legacy SIGs, such as HE-SIG-B and EHT-SIG, may contain common fields and user-specific fields. Common and user-specific fields may be coded separately.

[0119] In some cases, common fields may be omitted. For example, in a compressed mode where non-OFDMA (orthogonal frequency multiple access) is applied, common fields may be omitted, and multiple STAs may receive PPDUs (e.g., data fields of PPDUs) over the same frequency band. In a non-compressed mode where OFDMA is applied, multiple users may receive PPDUs (e.g., data fields of PPDUs) over different frequency bands.

[0120] The number of user-specific fields can be determined based on the number of users. A single user block field can contain up to two user fields. Each user field can be associated with either MU-MIMO allocation or non-MU-MIMO allocation.

[0121] The common field may include CRC bits and Tail bits, the length of the CRC bits may be determined as 4 bits, and the length of the Tail bits may be determined as 6 bits and set to 000000. The common field may include RU allocation information. The RU allocation information may include information about the location of RUs to which multiple users (i.e., multiple receiving STAs) are allocated.

[0122] An RU can contain multiple subcarriers (or tones). RUs can be used when transmitting signals to multiple STAs based on OFDMA techniques. RUs can also be defined when transmitting signals to a single STA. Resources can be allocated on an RU basis for non-legacy STFs, non-legacy LTFs, and data fields.

[0123] Depending on the PPDU bandwidth, an applicable RU size can be defined. The RU may be defined identically or differently for the applicable PPDU format (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.). For example, in the case of an 80MHz PPDU, the RU arrangements of HE PPDU and EHT PPDU may be different. The applicable RU size, RU number, RU position, DC (direct current) subcarrier position and number, null subcarrier position and number, guard subcarrier position and number, etc. for each PPDU bandwidth can be referred to as a tone plan. For example, a tone plan for a wide bandwidth can be defined in the form of multiple repetitions of a low bandwidth tone plan.

[0124] RUs of different sizes can be defined, such as 26-ton RU, 52-ton RU, 106-ton RU, 242-ton RU, 484-ton RU, 996-ton RU, 2X996-ton RU, 4X996-ton RU, etc. A multiple RU (MRU) is distinguished from multiple individual RUs and corresponds to a group of subcarriers consisting of multiple RUs. For example, one MRU can be defined as 52+26-tons, 106+26-tons, 484+242-tons, 996+484-tons, 996+484+242-tons, 2X996+484-tons, 3X996-tons, or 3X996+484-tons. Additionally, multiple RUs constituting one MRU may or may not be consecutive in the frequency domain.

[0125] The specific size of an RU may be reduced or expanded. Therefore, the specific size of each RU (i.e., the number of corresponding tones) in the present disclosure is not limited and is exemplary. Furthermore, within a given bandwidth (e.g., 20, 40, 80, 160, 320 MHz, etc.) in the present disclosure, the number of RUs may vary depending on the RU size.

[0126] The names of each field in the PPDU formats of FIG. 7 are exemplary and the scope of the present disclosure is not limited by those names. Furthermore, the examples of the present disclosure can be applied not only to the PPDU format exemplified in FIG. 7, but also to a new PPDU format in which some fields are excluded and / or some fields are added based on the PPDU formats of FIG. 7.

[0127] Resource Unit

[0128] FIGS. 8 to 10 are diagrams for explaining examples of resource units of a wireless LAN system to which the present disclosure can be applied.

[0129] Referring to FIGS. 8 to 10, a resource unit (RU) defined in a wireless LAN system is described. An RU may include multiple subcarriers (or tones). An RU may be used when transmitting signals to multiple STAs based on OFDMA techniques. An RU may also be defined when transmitting signals to a single STA. An RU may be used for the STF, LTF, and data fields of a PPDU.

[0130] As illustrated in FIGS. 8 to 10, RUs corresponding to different numbers of tones (i.e., subcarriers) may be used to configure some fields of a 20 MHz, 40 MHz, or 80 MHz X-PPDU (X represents HE, EHT, etc.). For example, resources may be allocated in units of RUs illustrated for the X-STF, X-LTF, and Data fields.

[0131] Figure 8 is a diagram showing an exemplary arrangement of resource units (RUs) used on a 20 MHz band.

[0132] As shown at the top of Fig. 8, 26 units (i.e., units corresponding to 26 tones) may be allocated. Six tones may be used as a guard band in the leftmost band of the 20 MHz band, and five tones may be used as a guard band in the rightmost band of the 20 MHz band. In addition, seven DC tones may be inserted in the center band, i.e., the DC band, and 26 units corresponding to 13 tones may exist on each side of the DC band. In addition, 26 units, 52 units, and 106 units may be allocated to other bands. Each unit may be allocated for an STA or a user.

[0133] The RU arrangement of Fig. 8 can be utilized not only in situations for multiple users (MUs) but also in situations for a single user (SU), in which case it is possible to use one 242-unit as shown at the bottom of Fig. 8. In this case, three DC tones can be inserted.

[0134] In the example of FIG. 8, RUs of various sizes, such as 26-RU, 52-RU, 106-RU, and 242-RU, are exemplified, but the specific sizes of these RUs may be reduced or expanded. Therefore, the specific size of each RU (i.e., the number of corresponding tones) in the present disclosure is not limited and is exemplary. In addition, in the present disclosure, within a given bandwidth (e.g., 20, 40, 80, 160, 320 MHz, ...), the number of RUs may vary depending on the RU size. In the examples of FIG. 9 and / or FIG. 10 described below, the fact that the size and / or number of RUs may be changed is the same as the example of FIG. 8.

[0135] Figure 9 is a diagram showing an exemplary arrangement of resource units (RUs) used on a 40 MHz band.

[0136] As in the example of FIG. 8 where RUs of various sizes were used, the example of FIG. 9 may also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. In addition, five DC tones may be inserted at the center frequency, 12 tones may be used as a guard band in the leftmost band of the 40 MHz band, and 11 tones may be used as a guard band in the rightmost band of the 40 MHz band.

[0137] Additionally, as shown, when used for a single user, 484-RU may be used.

[0138] Figure 10 is a diagram showing an exemplary arrangement of resource units (RUs) used on the 80 MHz band.

[0139] As in the examples of FIGS. 8 and 9 where RUs of various sizes were used, the example of FIG. 10 may also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, 996-RU, etc. In addition, in the case of 80MHz PPDU, the RU arrangement of HE PPDU and EHT PPDU may be different, and the example of FIG. 10 shows an example of the RU arrangement for 80MHz EHT PPDU. In the example of FIG. 10, 12 tones are used as guard bands in the leftmost band of the 80MHz band, and 11 tones are used as guard bands in the rightmost band of the 80MHz band, which is the same for HE PPDU and EHT PPDU. Unlike the HE PPDU, which has seven DC tones inserted into the DC band and one 26-RU corresponding to 13 tones on each side of the DC band, the EHT PPDU has 23 DC tones inserted into the DC band and one 26-RU corresponding to 13 tones on each side of the DC band. Unlike the HE PPDU, which has one null subcarrier between the 242-RUs other than the center band, the EHT PPDU has five null subcarriers. In the HE PPDU, one 484-RU does not contain a null subcarrier, but in the EHT PPDU, one 484-RU contains five null subcarriers.

[0140] Also, as shown, when used for a single user, 996-RU can be used, in which case the insertion of 5 DC tones is common in both HE PPDU and EHT PPDU.

[0141] An EHT PPDU of 160MHz or higher may be configured with multiple 80MHz subblocks as shown in FIG. 10. The RU layout for each 80MHz subblock may be the same as the RU layout of the 80MHz EHT PPDU as shown in FIG. 10. If an 80MHz subblock of a 160MHz or 320MHz EHT PPDU is not punctured and the entire 80MHz subblock is used as part of an RU or MRU (Multiple RU), the 80MHz subblock may use 996-RU as shown in FIG. 10.

[0142] Here, an MRU corresponds to a group of subcarriers (or tones) composed of multiple RUs, and the multiple RUs constituting an MRU may be RUs of the same size or different sizes. For example, a single MRU may be defined as 52+26-tones, 106+26-tones, 484+242-tones, 996+484-tones, 996+484+242-tones, 2X996+484-tones, 3X996-tones, or 3X996+484-tones. Here, the multiple RUs constituting one MRU may correspond to RUs of small size (e.g., 26, 52, 106) or RUs of large size (e.g., 242, 484, 996, etc.). That is, a single MRU containing both small-sized RUs and large-sized RUs may not be configured / defined. Furthermore, multiple RUs constituting a single MRU may or may not be consecutive in the frequency domain.

[0143] If an 80MHz subblock contains RUs smaller than 996 tones, or portions of the 80MHz subblock are punctured, the 80MHz subblock may use RU layouts other than the 996-tone RUs.

[0144] The RU of the present disclosure can be used for uplink (UL) and / or downlink (DL) communication. For example, when trigger-based UL-MU communication is performed, an STA (e.g., an AP) transmitting a trigger 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 through trigger information (e.g., a trigger frame or triggered response scheduling (TRS)). Thereafter, the first STA can transmit a first trigger-based (TB) PPDU based on the first RU, and the second STA can transmit a second TB PPDU based on the second RU. The first / second TB PPDU can be transmitted to the AP in the same time interval.

[0145] For example, when a DL MU PPDU is configured, an STA (e.g., an AP) transmitting a DL MU PPDU may 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 transmitting STA (e.g., the AP) may transmit X-STF (e.g., X is HE, EHT, etc.), X-LTF, and Data fields for the first STA through the first RU within one MU PPDU, and may transmit X-STF, X-LTF, and Data fields for the second STA through the second RU. Information about the arrangement of RUs may be signaled through an X-SIG (e.g., X is HE, EHT, U) field of the X-PPDU format.

[0146] Distributed resource units

[0147] Regulations in various regions may impose power spectral density (PSD) limitations in the sub-7GHz (e.g., 6GHz) band. For non-AP STAs in the low power indoor (LPI) band, the PSD limitation may be -1dBm / MHz. For example, for a conventional 52-tone RU, the maximum transmit (Tx) power may be approximately 6dBm.

[0148] Additionally, different restrictions may apply in the 2.4 GHz and 5 GHz bands. For example, a PSD restriction of 10 dBm / MHz may apply in the EU / China / Japan / Korea in the 2.4 GHz band. This would result in a maximum Tx power of approximately 17 dBm for a conventional 52-tone RU. Bypassing the PSD restriction in the 5 GHz band would allow for higher transmit power. For example, the maximum transmit power for a conventional 52-tone RU is 24 dBm, which is still 6 dBm below the maximum allowable effective isotropic radiated power (EIRP) of 30 dBm.

[0149] Overcoming PSD limitations can increase transmit power, thereby improving spectral efficiency or extending range.

[0150] Considering that the PSD limit is defined per MHz for each STA, when distributing tones of small RUs over a wide bandwidth, the tones for each STA are non-contiguous, so each tone can be transmitted at high power. An RU containing such distributed tones is called a distributed RU (DRU), and to distinguish it from an RU containing continuous tones defined in a conventional wireless LAN system (e.g., a system according to IEEE 802.11ax, 11be, etc.) can be called a regular RU (RRU).

[0151] Compared to STAs transmitting on conventional RRUs, STAs transmitting on DRUs can use higher power. For example, a 52-tone DRU across 80 MHz has only one tone per MHz, whereas a 52-tone RRU has approximately 13 tones per MHz. Assuming a PSD limit of -1 dBm / MHz in the 6 GHz LPI band, using a DRU increases the transmit power by approximately 11 dB for a 52-tone RU. This increased transmit power allows for a higher MCS and longer range.

[0152] FIG. 11 is a drawing illustrating examples of DRUs to which the present disclosure can be applied.

[0153] In the example of Fig. 11, STA1 transmits on DRU1, STA2 transmits on DRU2, and STA3 transmits on DRU3. Each STA can apply a transmission power boost by using a DRU. Compared to cases where RRUs of the same size are used, the DRU applies higher transmission power to all tones, and thus, spectral efficiency can be significantly improved. In this way, the DRU can be applied particularly usefully in UL-OFDMA.

[0154] APs can also utilize DRUs. In some cases, the AP may use only some of DRUs (DRU1, DRU2, and DRU3) to transmit DL-OFDMA to STA(s), in which case the transmit power boost due to the use of DRUs may be applied.

[0155] To maximize power boost, tones within a single DRU can be distributed as far apart as possible. For example, a DRU containing one tone per MHz may be considered optimal. The size of a DRU (or the number of available tones contained in a DRU, i.e., the number of tones excluding unusable tones such as null tones, guard tones, and DC tones) can be defined to be the same as the size of an RRU (or the number of available tones contained in an RRU). This can minimize the impact on various technologies that are already defined based on RRUs. The table below shows examples of achievable power boost (in dB) for various DRUs distributed over different bandwidths. The examples in the table below assume the 6 GHz LPI band, and power boost can also be achieved in the 2.4 GHz and 5 GHz bands in other regions. For example, in an 80 MHz UL-OFDMA transmission by 8 users, if each user uses a 106-tone DRU, the overall performance can be improved by approximately 8.13 dB compared to when each user uses a 106-tone RRU. Thus, by using DRUs, the PSD limitation can be overcome and significant gains can be obtained.

[0156] 20MHz bandwidth 40MHz bandwidth 80MHz bandwidth 26-tone RU8.1311.1411.1452-tone RU6.378.1311.14106-tone RU3.366.378.13242-tone RU Not applicable 2.695.12484-tone RU Not applicable Not applicable 2.69

[0157] trigger frame

[0158] FIG. 12 is a drawing showing an exemplary format of a trigger frame to which the present disclosure can be applied.

[0159] A trigger frame may allocate resources for the transmission of one or more TB PPDUs and request the transmission of TB PPDUs. The trigger frame may also include other information required by the STA transmitting the TB PPDU in response. The trigger frame may include common information and a user information list field in the frame body.

[0160] The common information field may include information that is common to one or more TB PPDU transmissions requested by a trigger frame, such as trigger type, UL length, presence of a subsequent trigger frame (e.g., More TF), whether CS (channel sensing) is required, UL BW (bandwidth), DRU / RRU indication, etc. Fig. 12 illustrates an example of a UHR variant common information field format.

[0161] The 4-bit trigger type subfield can have values ​​from 0 to 15. Among them, the values ​​0, 1, 2, 3, 4, 5, 6, and 7 of the trigger type subfield are defined to correspond to basic, Beamforming Report Poll (BFRP), multi user-block acknowledgement request (MU-BAR), multi user-request to send (MU-RTS), Buffer Status Report Poll (BSRP), groupcast with retries (GCR), MU-BAR, Bandwidth Query Report Poll (BQRP), and NDP Feedback Report Poll (NFRP), respectively, and the values ​​8 to 15 are defined as reserved.

[0162] The DRU / RRU indication subfield indicates whether distributed RU (DRU) or regular RU (RRU) transmission is requested in each 80MHz frequency subblock. The indication by the DRU / RRU indication subfield can be configured in units of 80MHz frequency subblocks. For example, if the DRU / RRU indication subblock format consists of 4 bits (B0, B1, B2, B3), B0 can be used for DRU / RRU indication for the lowest 80MHz frequency subblock, B1 can be used for DRU / RRU indication for the second-lower 80MHz frequency subblock, B2 can be used for DRU / RRU indication for the second-highest 80MHz frequency subblock, and B3 can be used for DRU / RRU indication for the highest 80MHz frequency subblock. When the UL BW is 20 MHz, 40 MHz, or 80 MHz, bits B1-B3 of the DRU / RRU Indication subfield may be reserved. When the UL BW is 160 MHz, bits B2-B3 of the DRU / RRU Indication subfield may be reserved. To request a UHR TB PPDU using DRU transmission in the 80 MHz frequency subblock, the corresponding bit in the DRU / RRU Indication subfield shall be set to 0, otherwise it shall be set to 1.

[0163] Among the common information, the trigger dependent common info subfield may include information that is optionally included based on the trigger type.

[0164] A special user info field may be included within the trigger frame. The special user info field does not contain user-specific information, but rather extended common information not provided in the common information field.

[0165] The user information list contains zero or more user information fields. Figure 12 illustrates an example of the UHR variant user information field format.

[0166] The AID12 subfield basically indicates that it is a user information field for an STA with the corresponding AID. In addition, if the AID12 field has a predetermined specific value, it may be utilized for other purposes, such as allocating a random access (RA)-RU, or being configured in the form of a special user information field. The special user information field is a user information field that does not contain user-specific information, but contains extended common information not provided in the common information field. For example, the special user information field can be identified by the AID12 value of 2007, and the special user information field flag subfield within the common information field can indicate whether the special user information field is included.

[0167] The RU allocation subfield may indicate the size and location of an RU / MRU. For this purpose, the RU allocation subfield may be interpreted together with the PS160 (primary / secondary 160MHz) subfield of the user information field, the UL BW extension subfield of the special user information field, the UL BW subfield of the common information field, etc. In addition, if an RU allocated in the RU allocation of the user information field is located in an 80MHz frequency subblock in which the corresponding bit in the DRU / RRU indication subfield of the UHR variant common information field is set to 1, or in two or more 80MHz frequency subblocks in which the corresponding bits in the DRU / RRU indication subfields of the UHR variant common information field are all set to 1, the allocated RU may be an RRU or an MRU.

[0168] For example, the mapping of B7-B1 of the RU Allocation subfield can be defined together with the settings of B0 and PS160 subfields of the RU Allocation subfield as shown in Table 2 below. Table 2 shows an example of encoding of the PS160 subfield and the RU Allocation subfield of a user information field (e.g., a user information field based on an EHT variant or UHR variant).

[0169]

[0170]

[0171] When B0 of the RU Allocation subfield is set to 0, it may indicate that the RU / MRU allocation is applied to the primary 80 MHz channel, and when its value is set to 1, it may indicate that the RU allocation is applied to the secondary 80 MHz channel of the primary 160 MHz. When B0 of the RU Allocation subfield is set to 0, it may indicate that the RU / MRU allocation is applied to the lower 80 MHz of the secondary 160 MHz, and when its value is set to 1, it may indicate that the RU allocation is applied to the upper 80 MHz of the secondary 160 MHz.

[0172] In the trigger frame RU allocation table of Table 2, the parameter N can be calculated based on the formula N=2*X1+X0. For a bandwidth of 80 MHz or less, the values ​​of PS160, B0, X0, and X1 can be set to 0. For a bandwidth of 160 MHz and a bandwidth of 320 MHz, the values ​​of PS160, B0, X0, and X1 can be set as shown in Table 3. These settings represent the absolute frequency order for the primary and secondary 80 MHz and 160 MHz channels. The order from left to right represents the order from low frequency to high frequency. The primary 80 MHz channel is represented as P80, the secondary 80 MHz channel is represented as S80, and the secondary 160 MHz channel is represented as S160.

[0173]

[0174] The SS allocation subfield may be configured differently depending on whether the subfield is associated with an RRU or a DRU.

[0175] For example, the SS allocation subfield of the UHR variant user information field associated with an RRU may include a starting spatial stream subfield and a number of spatial streams subfield. As another example, the SS allocation subfield of the UHR variant user information field associated with a DRU may include a DRU distributed bandwidth (DBW) subfield and a number of spatial streams subfield. In other words, the SS allocation subfield may indicate the DRU DBW and spatial streams of the requested UHR TB PPDU. The DRU DBW subfield indicates the DBW of the allocated DRU, and when the DRU DBW subfield consists of 2 bits, values ​​0 to 3 may be defined for 20MHz DBW, 40MHz DBW, 80MHz DBW, and 60MHz DBW.

[0176] DRU tone plan-based transmission and reception

[0177] As mentioned above, to overcome PSD limitations and improve power gain, a DRU using distributed tones / subcarriers rather than an RRU using continuous tones / subcarriers can be applied.

[0178] In the present disclosure, a method is proposed for allocating DRUs by considering the distribution bandwidth (DBW) of the DRUs when a TB PPDU to which a DRU is applied is requested in a trigger frame.

[0179] The distributed bandwidth can refer to the size of the channels over which the DRUs are distributed. For example, distributed bandwidths such as 20MHz DBW, 40MHz DBW, 60MHz DBW, 80MHz DBW, and 160MHz DBW can be defined, and DRU tone plans can be defined for bandwidths of the same size. For example, a 60MHz DBW and tone plan can be defined for all channels except the highest 20MHz channel in a specific 80MHz frequency subblock.

[0180] That is, each DRU tone plan can be defined / applied in each DBW situation, and the same DRU size as the RU size of the tone plan defined in the existing same-sized bandwidth can be defined, and the same number of DRUs as the RUs defined in each size can be defined. In addition, similar to the way in which a large-sized RU is defined by combining RUs of different small sizes, a large-sized DRU can be defined by combining DRUs of different small sizes. In addition, when allocating a DRU, an existing RU can be mapped to a DRU one-to-one, and the DRU can be allocated based on the RU allocation method.

[0181] However, RU allocation in existing trigger frames (e.g., the trigger frame in FIG. 12) is a method of indicating which RU is used in consideration of the 80MHz subblock unit instruction and 80MHz RRU tone plan (e.g., a method of indicating the RU index, as in Table 2). Considering this, if DRUs are distributed to different small channels in 80MHz subblock units, ambiguity may occur due to differences in the index of the RU allocation and the index of the DRU.

[0182] Below, we describe solutions to the aforementioned problems.

[0183] First, the trigger frame may contain information indicating the specific channel to which the DRU applies and how the DBW is configured within the channel to which the DRU applies.

[0184] The trigger frame may have the following structure as an enhanced form of an existing trigger frame (e.g., a trigger frame based on an EHT variant), and some fields may not be used or other fields may be added.

[0185] - UHR Variant Common Information Field | EHT Variant Special User Information Field | UHR Variant Special User Information Field | HE Variant User Information Field | EHT Variant User Information Field | UHR Variant User Information Field

[0186] Here, UHR variant common information field, UHR variant special information field, and UHR variant user information field can be defined by improving existing fields of the same name (e.g., fields based on EHT variant).

[0187] For example, an indication of whether DRU transmission is applicable can be performed by defining a 1-bit subfield. Specifically, a value of 1 can be defined to indicate RRU transmission, a value of 0 can be defined to indicate DRU transmission, and vice versa. The subfield can be defined in the UHR variant common information field, the UHR variant special user information field, or the UHR variant user information field.

[0188] For another example, the indication of whether DRU transmission is applied can be performed using a 4-bit bitmap (e.g., using B56 to B59 of the UHR variant common information field). Specifically, the 80MHz frequency subblocks can be mapped one-to-one from the lowest 80MHz frequency subblock in the order of the bits of the lowest index to the bits of the highest index, and can indicate information about whether the 80MHz frequency subblock is an RRU transmission or a DRU transmission. For example, a value of 1 can be defined to indicate an RRU transmission, a value of 0 can be defined to indicate a DRU transmission, and vice versa.

[0189] Additionally, a 2-bit subfield may be defined to indicate the distributed bandwidth of a DRU to which a specific STA is assigned. The 2-bit subfield may be defined in the UHR Variant Common Information field, the UHR Variant Special User Information field, or the UHR Variant User Information field. The indication by the 2-bit subfield may be based on one or more of the following examples.

[0190] - Example 1. Value 0: 20MHz, Value 1: 40MHz, Value 2: 80MHz, Value 3: 160MHz

[0191] - Example 2. Value 0: 20MHz, Value 1: 40MHz, Value 2: 80MHz, Value 3: 60MHz

[0192] - Example 3. Value 0: 20MHz, Value 1: 40MHz, Value 2: 60MHz, Value 3: 80MHz

[0193] Additionally, in specific fields of the trigger frame (e.g., UHR Variant Common Information Field, UHR Variant Special User Information Field), both instructions for DRU application and DRU DBW mode can be performed. In this regard, the instructions can be set to different values ​​for each channel of a specific size above a specific bandwidth, depending on the DBW mode of the RRU or DRU applied to the channel.

[0194] Additionally, in the case of the method of allocating DRUs, the channel to which the DRU is applied is indicated in units of 80MHz subblocks, as in the existing RU allocation method (e.g., the method based on Table 2), but considering the DBW to which the DRU is applied, the DRU index indicated by the RU allocation method may be changed differently from the RU index (e.g., the RRU index) indicated by the existing RU allocation method.

[0195] Below, the method for directing DRU allocation is specifically described through various cases based on the channel and DBW mode to which the DRU is applied. In this regard, the method for directing DRU allocation can be redefined by changing the RU index indicated in the previously described existing method for directing RU (e.g., RRU) allocation (e.g., the method based on Table 2).

[0196] Case 1. DRU is applied to a specific 20MHz channel and DBW is 20MHz

[0197] The 80MHz subblock (e.g., 80MHz frequency subblock) to which the corresponding 20MHz channel belongs is indicated using B0 of the PS160 subfield and the RU allocation subfield, and the RU index of the corresponding 20MHz can be changed to the RU index of the 20MHz tone plan. For example, the RU index of the corresponding 20MHz channel can be changed to the DRU index of the 20MHz DRU tone plan.

[0198] As a specific example, when a DRU of 20MHz DBW is applied to the first 20MHz channel in an 80MHz subblock, one of 26-tone RU 1 to RU 9, 52-tone RU 1 to RU 4, 106-tone RU 1 and RU 2 may be indicated, and the RU index may not be changed. That is, referring to Table 2, one of values ​​0 to 8, 37 to 40, and 53 to 54 by B7 to B1 of the RU allocation subfield may be indicated, and at this time, the RU index i may be changed to the DRU index i.

[0199] When a DRU of 20MHz DBW is applied to the second 20MHz channel within an 80MHz subblock, one of 26-tone RU 10 to RU 18, 52-tone RU 5 to RU 8, 106-tone RU 3 and RU 4 may be indicated, and the indices of 26-tone RU 10 to RU 18 may be changed to 1 to 9, the indices of 52-tone RU 5 to RU 8 may be changed to 1 to 4, and the indices of 106-tone RU 3 and RU 4 may be changed to 1 and 2. That is, referring to Table 2, one of the values ​​9 to 17, 41 to 44, and 55 to 56 may be indicated by B7 to B1 of the RU allocation subfield, and 26-tone RU 10 to RU 18 may be changed to 26-tone DRU 1 to DRU 9, 52-tone RU 5 to RU 8 may be changed to 52-tone DRU 1 to DRU 4, and 106-tone RU 3 and RU 4 may be changed to 106-tone DRU 1 and DRU 2.

[0200] When a DRU of 20MHz DBW is applied to the third 20MHz channel within an 80MHz subblock, one of 26-tone RU 20 to RU 28, 52-tone RU 9 to RU 12, 106-tone RU 5 and RU 6 may be indicated, and the indexes of 26-tone RU 20 to RU 28 may be changed to 1 to 9, the indexes of 52-tone RU 9 to RU 12 may be changed to 1 to 4, and the indexes of 106-tone RU 5 and RU 6 may be changed to 1 and 2. That is, referring to Table 2, one of the values ​​19 to 27, 45 to 48, and 57 to 58 may be indicated by B7 to B1 of the RU allocation subfield, and 26-tone RU 20 to RU 28 may be changed to 26-tone DRU 1 to DRU 9, 52-tone RU 9 to RU 12 may be changed to 52-tone DRU 1 to DRU 4, and 106-tone RU 5 and RU 6 may be changed to 106-tone DRU 1 and DRU 2.

[0201] When a DRU of 20MHz DBW is applied to the fourth 20MHz channel within an 80MHz subblock, one of 26-tone RU 29 to RU 37, 52-tone RU 13 to RU 16, 106-tone RU 7 and RU 8 may be indicated, and the indexes of 26-tone RU 29 to RU 37 may be changed to 1 to 9, the indexes of 52-tone RU 13 to RU 16 may be changed to 1 to 4, and the indexes of 106-tone RU 7 and RU 8 may be changed to 1 and 2. That is, referring to Table 2, one of the values ​​28 to 36, 49 to 52, and 59 to 60 may be indicated by B7 to B1 of the RU allocation subfield, and 26-tone RU 29 to RU 37 may be changed to 26-tone DRU 1 to DRU 9, 52-tone RU 13 to RU 16 may be changed to 52-tone DRU 1 to DRU 4, and 106-tone RU 7 and RU 8 may be changed to 106-tone DRU 1 and DRU 2.

[0202] Case 2. DRU is applied to a specific 40MHz channel and DBW is 40MHz

[0203] The 80MHz subblock (e.g., 80MHz frequency subblock) to which the 40MHz channel belongs is indicated using B0 of the PS160 subfield and the RU allocation subfield, and the RU index of the 40MHz can be changed to the RU index of the 40MHz tone plan. For example, the RU index of the 40MHz channel can be changed to the DRU index of the 40MHz DRU tone plan.

[0204] As a specific example, when a DRU of 40MHz DBW is applied to the first 40MHz channel in an 80MHz subblock, one of 26-tone RU 1 to RU 18, 52-tone RU 1 to RU 8, 106-tone RU 1 to RU 4, 242-tone RU 1 and RU 2 may be indicated, and the RU index may not be changed. That is, referring to Table 2, one of the values ​​0 to 17, 37 to 44, 53 to 56, 61, and 62 by B7 to B1 of the RU allocation subfield may be indicated, and at this time, the RU index i may be changed to the DRU index i.

[0205] When a DRU of 40MHz DBW is applied to the second 40MHz channel within an 80MHz subblock, one of 26-tone RU 20 to RU 37, 52-tone RU 9 to RU 16, 106-tone RU 5 to RU 8, 242-tone RU 3 and RU 4 may be indicated, and the indexes of 26-tone RU 20 to RU 37 may be changed to 1 to 18, the indexes of 52-tone RU 9 to RU 16 may be changed to 1 to 8, the indexes of 106-tone RU 5 to RU 8 may be changed to 1 to 4, and the indexes of 242-tone RU 3 and RU 4 may be changed to 1 and 2. That is, referring to Table 2, one of the values ​​19 to 36, 45 to 52, 57 to 60, 63 and 64 may be indicated by B7 to B1 of the RU allocation subfield, and 26-tone RU 20 to RU 37 may be changed to 26-tone DRU 1 to DRU 18, 52-tone RU 9 to RU 16 may be changed to 52-tone DRU 1 to DRU 8, 106-tone RU 5 to RU 8 may be changed to 106-tone DRU 1 to DRU 4, and 242-tone RU 3 and RU 4 may be changed to 242-tone DRU 1 and DRU 2.

[0206] Case 3. DRU is applied to a specific 40MHz channel and DBW is 20 / 20MHz.

[0207] The 80MHz subblock (e.g., 80MHz frequency subblock) to which the 40MHz channel belongs is indicated using B0 of the PS160 subfield and the RU allocation subfield, and the RU index of each 20MHz channel within the 40MHz channel can be changed to the RU index of the 20MHz tone plan.

[0208] For example, the RU index indicated by the position within the 80MHz frequency (sub)block of a channel to which 20MHz DBW is applied may be the same as when DRU is applied to a specific 20MHz channel and DBW is 20MHz (e.g., Case 1 described above). In this case, the RU indexes may be changed to the RU indexes of the 20MHz tone plan (e.g., the DRU indexes of the 20MHz DRU tone plan).

[0209] Case 4. DRU is applied to a specific 60MHz channel and DBW is 60MHz

[0210] In this regard, a 60MHz DBW may be defined for all channels except the highest 20MHz channel in a specific 80MHz frequency subblock.

[0211] The 80MHz subblock to which the corresponding 60MHz channel belongs (e.g., 80MHz frequency subblock) can be indicated using B0 of the PS160 subfield and the RU allocation subfield.

[0212] In this case, one of 26-tone RU 1 to RU 18 and RU 20 to RU 28, 52-tone RU 1 to RU 12, 106-tone RU 1 to RU 6, and 242-tone RU 1 to RU 3 may be indicated, and the RU index may not be changed. In addition, according to the definition of 484-tone DRU, 484-tone RU 1 and RU 2 may also be indicated. That is, referring to Table 2, one of the values ​​0 to 17, 19 to 27, 37 to 48, 53 to 58, and 61 to 63 by B7 to B1 of the RU allocation subfield may be indicated, and in this case, the RU index i may be changed to the DRU index i.

[0213] Case 5. DRU is applied to a specific 80MHz channel and DBW is 80MHz.

[0214] In this case, the instruction method based on Table 2 can be used as is, and the RU index i in Table 2 can be changed to the DRU index i.

[0215] Case 6. DRU is applied to a specific 80MHz channel and DBW is applied to 20 / 20 / 40MHz or 40 / 20 / 20MHz.

[0216] Using B0 of the PS160 subfield and the RU allocation subfield, an 80MHz subblock (e.g., an 80MHz frequency subblock) to which DBW is applied is indicated, and the RU indexes of two 20MHz channels where 20MHz DBW is used can be changed to the RU index of the 20MHz tone plan, and the RU index of a 40MHz channel where 40MHz DBW is used can be changed to the RU index of the 40MHz tone plan.

[0217] For example, the RU index indicated according to the position within the 80MHz frequency (sub)block of a channel to which 20MHz DBW is applied may be the same as the case where DRU is applied to a specific 20MHz channel and DBW is 20MHz (e.g., Case 1 described above). In this case, the corresponding RU indexes may be changed to the RU index of the 20MHz tone plan (e.g., the DRU index of the 20MHz DRU tone plan). In addition, the RU index indicated according to the position within the 80MHz frequency (sub)block of a channel to which 40MHz DBW is applied may be the same as the case where DRU is applied to a specific 40MHz channel and DBW is 40MHz (e.g., Case 2 described above). In this case, the corresponding RU indexes may be changed to the RU index of the 40MHz tone plan (e.g., the DRU index of the 40MHz DRU tone plan).

[0218] Case 7. When a DRU is applied to a specific 80MHz channel and a 20MHz channel is punctured (represented as P20), i.e., P20 / 20 / 40MHz, 20 / P20 / 40MHz, 40 / P20 / 20MHz, or 40 / 20 / P20MHz.

[0219] Using B0 of the PS160 subfield and the RU allocation subfield, an 80MHz subblock (e.g., an 80MHz frequency subblock) to which DBW is applied is indicated, and the RU indexes of two 20MHz channels where 20MHz DBW is used can be changed to the RU index of the 20MHz tone plan, and the RU index of a 40MHz channel where 40MHz DBW is used can be changed to the RU index of the 40MHz tone plan.

[0220] For example, the RU index indicated according to the position within the 80MHz frequency (sub)block of a channel to which 20MHz DBW is applied may be the same as the case where DRU is applied to a specific 20MHz channel and DBW is 20MHz (e.g., Case 1 described above). In this case, the corresponding RU indexes may be changed to the RU index of the 20MHz tone plan (e.g., the DRU index of the 20MHz DRU tone plan). In addition, the RU index indicated according to the position within the 80MHz frequency (sub)block of a channel to which 40MHz DBW is applied may be the same as the case where DRU is applied to a specific 40MHz channel and DBW is 40MHz (e.g., Case 2 described above). In this case, the corresponding RU indexes may be changed to the RU index of the 40MHz tone plan (e.g., the DRU index of the 40MHz DRU tone plan).

[0221] At this time, the punctured 20MHz channel may not require special definition since no DRU is allocated, or the values ​​may be reserved or used for other purposes.

[0222] Case 8. When a DRU is applied to a specific 80MHz channel and a 40MHz channel is punctured (represented as P40), i.e., P40 / 40MHz, 40 / P40MHz, P40 / 20 / 20MHz, or 20 / 20 / P40MHz.

[0223] Using B0 of the PS160 subfield and the RU allocation subfield, an 80MHz subblock (e.g., an 80MHz frequency subblock) to which DBW is applied is indicated, and the RU indexes of two 20MHz channels where 20MHz DBW is used can be changed to the RU index of the 20MHz tone plan, and the RU index of a 40MHz channel where 40MHz DBW is used can be changed to the RU index of the 40MHz tone plan.

[0224] For example, the RU index indicated according to the position within the 80MHz frequency (sub)block of a channel to which 20MHz DBW is applied may be the same as the case where DRU is applied to a specific 20MHz channel and DBW is 20MHz (e.g., Case 1 described above). In this case, the corresponding RU indexes may be changed to the RU index of the 20MHz tone plan (e.g., the DRU index of the 20MHz DRU tone plan). In addition, the RU index indicated according to the position within the 80MHz frequency (sub)block of a channel to which 40MHz DBW is applied may be the same as the case where DRU is applied to a specific 40MHz channel and DBW is 40MHz (e.g., Case 2 described above). In this case, the corresponding RU indexes may be changed to the RU index of the 40MHz tone plan (e.g., the DRU index of the 40MHz DRU tone plan).

[0225] At this time, the punctured 40MHz channel may not require special definition since no DRU is allocated, or the values ​​may be reserved or used for other purposes.

[0226] Case 9. When a DRU is applied to a specific 80MHz channel and two 20MHz channels located in the center are punctured, i.e., 20 / P20 / P20 / 20MHz.

[0227] In this case, two DBW modes may be considered. For example, a mode in which 20MHz DBW is applied to each of the non-punctured 20MHz channels (hereinafter referred to as the first mode) and a mode in which 40MHz DBW is applied to two 20MHz channels (hereinafter referred to as the second mode) may be considered. Information regarding this may be indicated through the DRU application and DBW mode indication.

[0228] The 80MHz subblock to which DBW is applied (e.g., 80MHz frequency subblock) can be indicated using B0 of the PS160 subfield and RU allocation subfield, and the setting / definition of specific values ​​can be different for the first mode and the second mode.

[0229] In the first mode, the RU indices of two 20MHz channels where 20MHz DBW is used can be changed to the RU indices of the 20MHz tone plan, respectively. For example, the RU indices indicated by the position within the 80MHz frequency (sub)block of the channel to which 20MHz DBW is applied can be the same as when DRU is applied to a specific 20MHz channel and the DBW is 20MHz (e.g., Case 1 described above). In this case, the RU indices can be changed to the RU indices of the 20MHz tone plan (e.g., the DRU indices of the 20MHz DRU tone plan).

[0230] For the second mode, the indicated RU indices are the same as in the former case (except that 242-tone RU 1 and 242-tone RU 4 can also be indicated), and for the first 20MHz channel within an 80MHz subblock, 26 / 52 / 106 / 242-tone RU indices can be used as is. In this case, RU index i can be changed to DRU index i. In contrast, for the last 20 MHz channel, the indices of 26-tone RUs 29 to RU 37 may be changed to 10 to 18 (e.g., 26-tone DRUs 10 to DRU 18), the indices of 52-tone RUs 13 to RU 16 may be changed to 5 to 8 (e.g., 52-tone DRUs 5 to 8), the indices of 106-tone RUs 7 and 8 may be changed to 3 and 4 (e.g., 106-tone DRUs 3 and 4), and the index of 242-tone RU 4 may be changed to 2 (e.g., 242-tone DRU 2).

[0231] Case 10. When DRU is applied to a specific 40MHz channel within a specific 80MHz channel, and RRU is applied to the remaining 40MHz channels.

[0232] The 80MHz subblock to which DBW is applied (e.g., 80MHz frequency subblock) can be indicated using B0 of the PS160 subfield and the RU allocation subfield.

[0233] At this time, the change of RU index in various DBW situations of a 40MHz channel to which DRU is applied may be the same as when DRU is applied to a specific 40MHz channel. For example, the RU index indicated according to the position within the 80MHz frequency (sub)block of a channel to which 40MHz DBW is applied may be the same as when DRU is applied to a specific 40MHz channel and the DBW is 40MHz (e.g., Case 2 described above). In this case, the corresponding RU indices may be changed to the RU index of the 40MHz tone plan (e.g., the DRU index of the 40MHz DRU tone plan).

[0234] If the 40MHz channel to which the RRU is applied is the first 40MHz channel within an 80MHz channel, one of 26-tone RUs 1 to 18, 52-tone RUs 1 to RU 8, 106-tone RUs 1 to RU 4, 242-tone RUs 1 and RU 2, and 484-tone RU 1 may be indicated, and the RU index may not be changed. In contrast, if the 40MHz channel to which the RRU is applied is the second 40MHz channel within an 80MHz channel, one of 26-tone RUs 20 to 37, 52-tone RUs 9 to RU 16, 106-tone RUs 5 to RU 8, 242-tone RUs 3 and RU 4, and 484-tone RU 2 may be indicated. At this time, the indexes of 26-ton RU 20 to RU 37 may be changed from 1 to 18, the indexes of 52-ton RU 9 to RU 16 may be changed from 1 to 8, the indexes of 106-ton RU 5 to RU 8 may be changed from 1 to 4, the indexes of 242-ton RU 3 and RU 4 may be changed to 1 and 2, and the index of 484-ton RU 2 may be changed to 1.

[0235] Case 11. DRU is applied to a specific 160MHz channel, and DBW is 160MHz.

[0236] The B0 of the PS160 subfield and the RU allocation subfield are used to indicate the lower 80MHz subblock and the upper 80MHz subblock of a 160MHz channel, but the RU index for the upper 80MHz subblock can be changed as in the following example.

[0237] For example, for a 26-tone DRU, the RU index can be set / defined by changing the RU index (for the low 80MHz subblock) by adding 37. For a 52-tone DRU, the RU index can be set / defined by changing the RU index (for the low 80MHz subblock) by adding 16. For a 106-tone DRU, the RU index can be set / defined by changing the RU index (for the low 80MHz subblock) by adding 8. For a 242-tone DRU, the RU index can be set / defined by changing the RU index (for the low 80MHz subblock) by adding 4. For a 484-tone DRU, the RU index can be set / defined by changing the RU index (for the low 80MHz subblock) by adding 2.

[0238] Additionally, the PHY RU index shown in the last column of Table 2 can be calculated using the RU index before the change even in a situation where DRU is applied.

[0239] The DRU indication method in the 20MHz / 40MHz / 80MHz DBW described above in the present disclosure can be defined as shown in Tables 4 to 6, respectively. That is, as shown in Tables 4 to 6, for 20MHz / 40MHz / 80MHz DBW, the mapping of B7-B1 of the RU allocation subfield can be defined together with the settings of B0 and PS160 subfields of the RU allocation subfield.

[0240] In Tables 4 to 6, the PHY DRU index may mean an index assigned when sequentially assigning indices to DRUs starting from low-frequency channels when DRUs are applied to all channels.

[0241] Table 4 illustrates the encoding of the PS160 subfield and RU allocation subfield of the UHR variant user information field for 20 MHz DBW.

[0242]

[0243] Table 5 shows an example of encoding of the PS160 subfield and RU allocation subfield of the UHR variant user information field for 40 MHz DBW.

[0244]

[0245] Table 6 shows an example of encoding of the PS160 subfield and RU allocation subfield of the UHR variant user information field for 80MHz DBW.

[0246]

[0247] Additionally, the DRU indication method in 60MHz DBW can be defined as in Table 7 or Table 8. Table 8 may correspond to an example in which the PHY DRU index is changed based on the number of 60MHz DBWs compared to Table 7.

[0248] Table 7 shows an example of the encoding of the PS160 subfield and the RU allocation subfield of the UHR variant user information field for 60 MHz DBW.

[0249]

[0250] Table 8 shows another example of encoding of the PS160 subfield and RU allocation subfield of the UHR variant user information field for 60 MHz DBW.

[0251]

[0252] In relation to the proposed method of the present disclosure, in the case of MU PPDU, the indication of whether to apply DRU transmission can be performed in L-SIG, U-SIG, or EHT-SIG, and the distributed bandwidth of the DRU can be indicated in U-SIG or EHT-SIG. Alternatively, both the indication of DRU application and the DBW mode of the DRU can be performed in U-SIG or EHT-SIG, and this can be set to different values ​​by the DBW mode of the RRU or DRU applied to each channel of a specific size for a specific bandwidth or more. This is an example and does not limit the scope of the present disclosure, and other methods may be applied.

[0253] In addition, with respect to the proposed method of the present disclosure, RU allocation information is transmitted in units of 20MHz in EHT-SIG, and the RU index can be set according to DBW rather than the entire bandwidth. For example, in case of 20MHz / 40MHz / 80MHz / 160MHz DBW, the RU index of the 20MHz / 40MHz / 80MHz / 160MHz channel can be set to the RU index of the 20MHz / 40MHz / 80MHz / 160MHz tone plan (e.g., the DRU index of the 20MHz / 40MHz / 80MHz / 160MHz DRU tone plan). In a case where two 20MHz channels located in the center of an 80MHz channel are punctured and 40MHz DBW is applied to two 20MHz channels that are not punctured, the RU index within the first 20MHz channel of the 40MHz tone plan can be set / defined for the first 20MHz channel, and the RU index within the second 20MHz channel of the 40MHz tone plan can be set / defined for the last 20MHz channel.

[0254] In addition, with respect to the proposed method of the present disclosure, the DRU for a PPDU can be transmitted and received on a channel exceeding 20 MHz. In the format of the PPDU, the legacy preamble (L-preamble) can be duplicated across all 20 MHz channels corresponding to (or overlapping with) the DRU (e.g., two or more 20 MHz channels). For example, if the DRU for a PPDU is transmitted / received on N*20 MHz channels, the legacy preambles on the N 20 MHz channels can be set identically.

[0255] For example, the legacy preamble may include L-STF, L-LTF, L-SIG. For example, the legacy preamble may additionally include RL-SIG and / or U-SIG in addition to L-STF, L-LTF, and L-SIG. When the legacy preamble includes U-SIG, the U-SIG may be repeated across 20 MHz channels within an 80 MHz channel, and the U-SIGs corresponding to different 80 MHz channels may be the same or different.

[0256] The remaining fields that do not correspond to the legacy preamble of the PPDU may be mapped onto the same tones / subcarriers as the DRU tones / subcarriers used by the data field. For example, among the fields other than the data field, the remaining fields that do not correspond to the legacy preamble may include the UHR-SIG, UHR-STF, UHR-LTF, and / or PE fields. The order of these fields is not restricted. For example, the UHR-SIG field may be located after the UHR-LTF, or may be located before the data field.

[0257] Below, in relation to the proposed method of the present disclosure, a method for applying DRU-based transmission to control frame-based transmission is described.

[0258] The aforementioned DRU-based transmission can also be applied to trigger frame (or control frame such as RTS, CTS, etc.)-based transmission. A trigger frame (TF) (or control frame such as RTS, CTS, etc.) transmitted from an AP to STA(s) can include information indicating a DRU allocated to a specific STA. A specific STA can transmit a trigger-based PPDU (TB PPDU) on the DRU allocated to it. The TB PPDU can include one or more of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, UHR-SIG, UHR-STF, UHR-LTF, and Data fields. Here, the UHR-LTF field and the Data field can be transmitted on a tone / subcarrier included in the DRU allocated to the STA in the TB PPDU.

[0259] The mapping / correspondence relationship between the DRU and the RRU may be predefined, or configuration information on the mapping / correspondence relationship between the DRU and the RRU may be provided from the AP to the STA. Based on this, the UHR-LTF sequence for a specific RRU may be applied identically as the UHR-LTF for the DRU corresponding to the specific RRU in the TB PPDU. More specifically, the UHR-LTF for the RRU may be defined with different lengths according to the channel size in which the RRU is included. In applying the UHR-LTF to the DRU, the UHR-LTF sequence may be applied, the length of which is defined according to the channel size in which the DRU is included (or the channel size in which the RRU corresponding to the DRU is included), rather than the bandwidth (BW) size of the TB PPDU.

[0260] As another example, whether or not to apply DRU can be set on a PPDU basis. In addition, the STA can transmit one or more PPDUs, and can transmit multiple PPDUs by integrating them in the frequency domain or configuring them as an aggregated PPDU (A-PPDU) in the time domain. The STA can be notified of whether or not to apply DRU, the bandwidth, etc. of one or more PPDUs transmitted on a specific channel through a control frame (e.g., a Trigger frame, an RTS frame, a CTS frame, etc.), or the STA can be notified of whether or not to apply DRU, the bandwidth, etc. of one or more PPDUs to be transmitted (or received) on the channel through which the control frame is transmitted.

[0261] The UHR-LTF sequence applied to the DRU can be defined as a 4x UHR-LTF sequence (i.e., a sequence in which only some number of elements in the sequence are 0 and the rest have non-zero values).

[0262] The relative position of the tone / subcarrier to which the UHR-LTF sequence applied in a specific RRU is mapped (i.e., which tone / subcarrier among all tones / subcarriers within the RRU) may be the same as the relative position of the tone / subcarrier to which the UHR-LTF sequence in the DRU corresponding to the specific RRU is mapped in the TB PPDU.

[0263] Additionally, the relative position of the pilot tone / subcarrier in the Data field applied in a specific RRU (i.e., which tone / subcarrier among all tones / subcarriers in the RRU) may be the same as the relative position of the pilot tone / subcarrier in the DRU corresponding to the specific RRU in the TB PPDU.

[0264] Below, a method for setting / instructing information related to DRU transmission is described in relation to the proposed method of the present disclosure.

[0265] For DRU-based transmission in the aforementioned TB PPDU, the trigger frame (or control frame such as RTS, CTS, etc.) may include information related to DRU transmission.

[0266] For example, information related to DRU transmission may include information indicating whether DRU or RRU is applied. The information may be defined as a 1-bit size, or may be defined as a bitmap having a length corresponding to a predetermined channel size. One bit of the bitmap may correspond to a 20MHz channel, and the bit value at each bit position may indicate whether DRU or RRU is applied to the corresponding 20MHz channel.

[0267] A given channel size corresponding to a bitmap length may correspond to a maximum channel size applicable to the DRU. If the bandwidth of a TB PPDU is larger than a given channel size, multiple bitmaps may be included in a trigger frame (or a control frame such as an RTS or CTS). Accordingly, the maximum channel size applicable to the DRU may be identified (or implicitly indicated) based on the bitmap length and / or number. Alternatively, information about a given channel size (or a maximum channel size applicable to the DRU) may be explicitly included in the trigger frame (or a control frame such as an RTS or CTS).

[0268] Additionally, the trigger frame may include information indicating the channel size to which the DRU is applied, and the allocation information of the DRU or whether the DRU is applied, channel size information, and the allocation information of the DRU may be notified through specific values ​​of fields of the trigger frame or through combinations of each value.

[0269] Below, STA operations based on various examples of the present disclosure described above are described with reference to FIGS. 13 and 14 . The examples in FIGS. 13 and 14 may correspond to some of the various examples of the present disclosure.

[0270] For example, in FIGS. 13 and 14, the first STA may correspond to a non-AP STA that receives a trigger frame requesting a TB PPDU, and the second STA may correspond to an AP that transmits the trigger frame. Here, the non-AP STA corresponding to the first STA may be an STA associated with the AP corresponding to the second STA.

[0271] FIG. 13 is a diagram for explaining an example of an operation by a first STA in a PPDU transmission and reception method based on a DRU tone plan according to the present disclosure.

[0272] Referring to FIG. 13, a first STA may receive a trigger frame including at least one field for allocating a distributed resource unit (DRU) from a second STA (S1310).

[0273] In this regard, at least one of the fields may indicate information about the DRU index based on the location and tone plan of the distributed channel (e.g., the channel having the DBW size).

[0274] According to the present disclosure, the at least one field may be defined to indicate 1) first information about an 80 MHz frequency subblock in which a DRU is located, and 2) second information about one of a plurality of values ​​grouped into a plurality of groups based on at least one of a location of a channel to which a distributed bandwidth is applied or a DRU size within the 80 MHz frequency subblock (e.g., see Tables 4 to 8).

[0275] As a specific example, the at least one field may include a first subfield (e.g., a PS160 subfield) and a second subfield (e.g., an RU allocation subfield) included in a user information field for the first STA within the trigger frame. Based on this, the first information may be indicated using some bits of the first subfield and the second subfield, and the second information may be indicated using the remaining bits of the second subfield.

[0276] In this regard, for groups with the same DRU size, the values ​​included in each group can be mapped to DRU indices based on the size of the distributed bandwidth and the tone plan for the DRU size.

[0277] For example, referring to Table 4 described above, when the size of the distributed bandwidth is 20 MHz and the DRU size is 26 tones, for four groups based on the locations of channels having the distributed bandwidth, nine values ​​included in each group can be mapped to DRU indices 1 to 9 in ascending order. In addition, when the size of the distributed bandwidth is 20 MHz and the DRU size is 52 tones, for four groups based on the locations of channels having the distributed bandwidth, four values ​​included in each group can be mapped to DRU indices 1 to 4 in ascending order. In addition, when the size of the distributed bandwidth is 20 MHz and the DRU size is 106 tones, for four groups based on the locations of channels having the distributed bandwidth, two values ​​included in each group can be mapped to DRU indices 1 and 2 in ascending order.

[0278] For example, referring to Table 5 described above, when the size of the distributed bandwidth is 40 MHz and the DRU size is 26 tones, for two groups based on the location of the channel having the distributed bandwidth, 18 values ​​included in each group can be mapped to DRU indices 1 to 18 in ascending order. In addition, when the size of the distributed bandwidth is 40 MHz and the DRU size is 52 tones, for two groups based on the location of the channel having the distributed bandwidth, 8 values ​​included in each group can be mapped to DRU indices 1 to 8 in ascending order. In addition, when the size of the distributed bandwidth is 40 MHz and the DRU size is 106 tones, for two groups based on the location of the channel having the distributed bandwidth, 4 values ​​included in each group can be mapped to DRU indices 1 to 4 in ascending order. Additionally, when the size of the distributed bandwidth is 40 MHz and the DRU size is 242 tones, for two groups based on the location of the channel with the distributed bandwidth, the two values ​​included in each group can be mapped to DRU indices 1 and 2 in ascending order.

[0279] For example, referring to Table 7 or Table 8 described above, when the size of the distributed bandwidth is 60 MHz, 12 values ​​included in a group having a DRU size of 52 tones may be mapped to DRU indices 1 to 12 in ascending order, 6 values ​​included in a group having a DRU size of 106 tones may be mapped to DRU indices 1 to 6 in ascending order, and 3 values ​​included in a group having a DRU size of 242 tones may be mapped to DRU indices 1 to 3 in ascending order.

[0280] For example, referring to Table 6 described above, when the size of the distributed bandwidth is 80 MHz, 16 values ​​included in a group having a DRU size of 52 tones may be mapped to DRU indices 1 to 16 in ascending order, 8 values ​​included in a group having a DRU size of 106 tones may be mapped to DRU indices 1 to 8 in ascending order, 4 values ​​included in a group having a DRU size of 242 tones may be mapped to DRU indices 1 to 4 in ascending order, and 2 values ​​included in a group having a DRU size of 484 tones may be mapped to DRU indices 1 and 2 in ascending order.

[0281] The first STA may transmit a TB PPDU to the second STA in response to the trigger frame of step S1310 (S1320).

[0282] In relation to the above-described operation, the trigger frame of step S1310 may include third information regarding whether a DRU or a regular RU (RRU) is applied and fourth information regarding the size of the channel on which the DRU is distributed. For example, the third information may be included in a common information field within the trigger frame, and the fourth information may be included in a user information field for the first SAT within the trigger frame. Here, the third information may include a subfield for indicating whether a DRU or RRU is applied in units of a frequency subblock of a certain size (e.g., an 80 MHz frequency subblock).

[0283] The method described in the example of FIG. 13 may be performed by the first device (100) of FIG. 1. For example, one or more processors (102) of the first device (100) of FIG. 1 may be configured to receive, via one or more transceivers (106), a trigger frame including at least one field for allocating a DRU, and to transmit a TB PPDU in response to the trigger frame. Furthermore, one or more memories (104) of the first device (100) may store commands for performing the method described in the example of FIG. 13 or the examples described above when executed by one or more processors (102).

[0284] FIG. 14 is a diagram for explaining an example of an operation by a second STA in a PPDU transmission and reception method based on a DRU tone plan according to the present disclosure.

[0285] Referring to FIG. 14, the second STA may transmit a trigger frame including at least one field for allocating a distributed resource unit (DRU) to the first STA (S1410).

[0286] In this regard, at least one of the fields may indicate information about the DRU index based on the location and tone plan of the distributed channel (e.g., the channel having the DBW size).

[0287] The second STA can receive a TB PPDU from the first STA in response to the trigger frame (S1420).

[0288] Specific details regarding the configuration / definition of at least one field for allocation of DRUs, the method of indicating information about the location of the channel on which the DRUs are distributed and the DRU index based on the tone plan, the setting / instruction for the distributed bandwidth of the DRUs, and the DRU-related instructions / signaling, etc. are the same as those described in the example of Fig. 13, so redundant descriptions are omitted.

[0289] The method described in the example of FIG. 14 may be performed by the second device (200) of FIG. 1. For example, one or more processors (202) of the second device (200) of FIG. 1 may be configured to transmit, via one or more transceivers (106), a trigger frame including at least one field for allocating a DRU, and receive, in response to the trigger frame, a TB PPDU. Furthermore, one or more memories (204) of the second device (200) may store commands for performing the method described in the example of FIG. 14 or the examples described above when executed by one or more processors (202).

[0290] FIG. 15 is a diagram illustrating a PPDU transmission and reception procedure between a transmitting STA and a receiving STA according to one embodiment of the present disclosure. Some of the steps shown in FIG. 15 may be omitted depending on circumstances and / or settings. The transmitting device and the receiving STA may be APs and / or non-AP STAs.

[0291] The transmitting STA may obtain control information related to the aforementioned tone plan (or RU / DRU) (S105). The control information related to the tone plan may include the size and location of the RU, control information related to the RU, information about the frequency band in which the RU is included, information about the STA receiving the RU, etc.

[0292] The transmitting STA may configure / generate a PPDU based on the acquired control information (S110). Configuring / generating a PPDU may mean configuring / generating each field of the PPDU. That is, the step of configuring / generating a PPDU may include a step of configuring a SIG field (e.g., U-SIG / UHR-SIG) that includes control information regarding a tone plan.

[0293] That is, the step of configuring / generating a PPDU may include a step of configuring a field including control information (e.g., N bitmap) indicating the size / position of the RU and / or a step of configuring a field including an identifier (e.g., AID) of an STA receiving the RU.

[0294] Additionally, the step of configuring / generating a PPDU may include a step of generating an STF / LTF sequence to be transmitted via a specific RU. The STF / LTF sequence may be generated based on a preset STF generation sequence / LTF generation sequence. For example, the LTF portion (e.g., LTF field) included in the PPDU may be configured based on the UHR-LTF sequence proposed in the present disclosure.

[0295] Additionally, the step of constructing / generating a PPDU may include a step of generating a data field (i.e., an MPDU) to be transmitted via a specific RU.

[0296] The transmitting STA can transmit the configured / generated PPDU to the receiving STA (S115).

[0297] Specifically, the transmitting STA can perform at least one of cyclic shift diversity (CSD), spatial mapping, inverse discrete Fourier transform (IDFT) / inverse fast Fourier transform (IFFT) operation, and guard interval (GI) insertion operation.

[0298] The receiving STA can decode the PPDU and obtain control information related to the tone-plan (or RU) (S120).

[0299] Specifically, the receiving STA can decode the L-SIG and SIG fields (e.g., U-SIG / UHR-SIG) of the PPDU based on the L-STF / LTF, and obtain information included in the L-SIG and SIG fields. Information about various tone plans (i.e., RUs) of the present disclosure can be included in the SIG field (e.g., U-SIG / UHR-SIG), and the receiving STA can obtain information about the tone plan (i.e., RU) through the corresponding SIG field.

[0300] The receiving STA can decode the remaining portion of the PPDU based on the acquired tone plan (i.e., RU) information (S125). For example, the receiving STA can decode the STF / LTF portion (e.g., the STF / LTF field) of the PPDU based on the tone plan (i.e., RU) information. In particular, the LTF portion can be configured by the UHR-LTF sequence proposed in the present disclosure and can be used for channel estimation purposes for decoding the data portion (e.g., the data field).

[0301] Additionally, the receiving STA can decode the data field of the PPDU based on information about the tone plan (i.e., RU) and obtain the MPDU included in the data field.

[0302] Additionally, the receiving STA may perform a processing operation to forward the decoded data to a higher layer (e.g., the MAC layer). Furthermore, if the higher layer instructs the PHY layer to generate a signal in response to the data forwarded to the higher layer, the receiving STA may perform a subsequent operation.

[0303] Unlike the existing wireless LAN system where only RRU is applied, in the case where application of DRU is supported, the efficiency of resource utilization can be improved by transmitting / receiving one or more fields of PPDU based on DRU tone plans of various sizes applicable to PPDUs of a bandwidth of 40 MHz or more according to the present disclosure.

[0304] The embodiments described above are combinations of components and features of the present disclosure in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form embodiments of the present disclosure by combining some components and / or features. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in another embodiment or may be replaced with corresponding components or features of another embodiment. It is self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form embodiments or incorporated as new claims through post-application amendments.

[0305] It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential characteristics thereof. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present disclosure are intended to be included within the scope of the present disclosure.

[0306] The scope of the present disclosure includes software or machine-executable instructions (e.g., an operating system, an application, firmware, a program, etc.) that cause operations according to the methods of various embodiments to be executed on a device or a computer, and a non-transitory computer-readable medium having such software or instructions stored thereon and executable on the device or computer. Instructions that can be used to program a processing system to perform the features described in the present disclosure can be stored on / in a storage medium or a computer-readable storage medium, and a computer program product including such a storage medium can be used to implement the features described in the present disclosure. The storage medium can include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices, and can include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. The memory optionally includes one or more storage devices remotely located from the processor(s). The memory or, alternatively, the non-volatile memory device(s) within the memory comprise a non-transitory computer-readable storage medium. The features described in this disclosure may be incorporated into software and / or firmware stored on any of the machine-readable media, which may control the hardware of the processing system and allow the processing system to interact with other mechanisms that utilize results according to embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0307] The method proposed in this disclosure is described with a focus on examples applied to IEEE 802.11-based systems, but can be applied to various wireless LANs or wireless communication systems in addition to IEEE 802.11-based systems.

Claims

1. A step of receiving, by a first station (STA), a trigger frame including at least one field for allocating a distributed resource unit (DRU) from a second STA; and A step of transmitting, by the first STA, a trigger-based (TB) PPDU (physical layer protocol data unit) to the second STA in response to the trigger frame, A method wherein said at least one field indicates information about a DRU index based on the location and tone plan of the distributed channel of said DRU.

2. In paragraph 1, At least one of the above fields, First information about the 80MHz frequency subblock where the DRU is located, and A method defined to indicate second information for one of a plurality of values ​​grouped into a plurality of groups based on at least one of the location of a channel to which the distributed bandwidth is applied or the DRU size within the above 80 MHz frequency subblock.

3. In paragraph 2, A method in which, for groups having the same DRU size, the values ​​included in the group are mapped to DRU indices based on the size of the distributed bandwidth and the tone plan for the DRU size.

4. In paragraph 3, Based on the above distributed bandwidth size being 20MHz and the DRU size being 26-tone, A method in which, for four groups based on the location of a channel having the above-mentioned distributed bandwidth, nine values ​​included in each group are mapped in ascending order to DRU indices 1 to 9.

5. In paragraph 3, Based on the above distributed bandwidth size being 20MHz and the DRU size being 52-tone, A method in which, for four groups based on the location of a channel having the above-mentioned distributed bandwidth, four values ​​included in each group are mapped in ascending order to DRU indices 1 to 4.

6. In paragraph 3, Based on the above distributed bandwidth size being 20MHz and the DRU size being 106-tone, A method in which, for four groups based on the location of a channel having the above distributed bandwidth, two values ​​included in each group are mapped to DRU indices 1 and 2 in ascending order.

7. In paragraph 3, Based on the above distributed bandwidth size being 40MHz and the DRU size being 26-tone, A method in which, for two groups based on the location of a channel having the above-mentioned distributed bandwidth, 18 values ​​included in each group are mapped in ascending order to DRU indices 1 to 18.

8. In paragraph 3, Based on the above distributed bandwidth size being 40MHz and the DRU size being 52-tone, A method in which, for two groups based on the location of a channel having the above-mentioned distributed bandwidth, eight values ​​included in each group are mapped in ascending order to DRU indices 1 to 8.

9. In paragraph 3, Based on the above distributed bandwidth size being 40MHz and the DRU size being 106-tone, A method in which, for two groups based on the location of a channel having the above-mentioned distributed bandwidth, four values ​​included in each group are mapped in ascending order to DRU indices 1 to 4.

10. In paragraph 3, Based on the above distributed bandwidth size being 40MHz and the DRU size being 242-tone, A method in which, for two groups based on the location of a channel having the above distributed bandwidth, two values ​​included in each group are mapped in ascending order to DRU indices 1 and 2.

11. In paragraph 3, Based on the above distributed bandwidth size being 60MHz, The 12 values ​​included in the group with the above DRU size of 52-ton are mapped in ascending order to DRU indices 1 to 12, The six values ​​included in the group whose DRU size is 106-ton are mapped in ascending order to DRU indices 1 to 6, A method in which three values ​​included in the group having the above DRU size of 242 tones are mapped in ascending order to DRU indices 1 to 3.

12. In paragraph 3, Based on the above distributed bandwidth size being 80MHz, The 16 values ​​included in the group with the above DRU size of 52-ton are mapped in ascending order to DRU indices 1 to 16, The eight values ​​included in the group with the above DRU size of 106-ton are mapped in ascending order to DRU indices 1 to 8, The four values ​​included in the group whose DRU size is 242-ton are mapped in ascending order to DRU indices 1 to 4, A method in which two values ​​included in the group having the above DRU size of 484 tones are mapped in ascending order to DRU indices 1 and 2.

13. In paragraph 2, The at least one field includes a first subfield and a second subfield included in a user information field for the first STA in the trigger frame, The above first information is indicated using some bits of the first subfield and the second subfield, A method in which the second information is indicated using the remaining bits of the second subfield.

14. In paragraph 1, A method wherein the trigger frame includes third information about whether a DRU or a regular RU (RRU) is applied and fourth information about the size of the channel over which the DRU is distributed.

15. In paragraph 14, The third information is included in the common information field within the trigger frame, A method wherein the fourth information is included in a user information field for the first STA in the trigger frame.

16. In paragraph 15, A method wherein the third information includes a subfield for indicating whether to apply a DRU or an RRU in units of frequency subblocks of a certain size.

17. One or more transmitters and receivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Receive a trigger frame including at least one field for distributed resource unit (DRU) allocation; In response to the above trigger frame, a trigger-based (TB) PPDU (physical layer protocol data unit) is set to be transmitted, A device wherein at least one field indicates information about a DRU index based on the location and tone plan of the distributed channel of the DRU.

18. A step of transmitting, by a second station (STA), a trigger frame including at least one field for distributed resource unit (DRU) allocation to a first STA; and A step of receiving, by the second STA, a trigger-based (TB) PPDU (physical layer protocol data unit) from the first STA in response to the trigger frame, A method wherein said at least one field indicates information about a DRU index based on the location and tone plan of the distributed channel of said DRU.

19. One or more transmitters and receivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Transmitting a trigger frame including at least one field for distributed resource unit (DRU) allocation to a first STA; By the second STA, in response to the trigger frame, a trigger-based (TB) PPDU (physical layer protocol data unit) is set to be received from the first STA, A device wherein at least one field indicates information about a DRU index based on the location and tone plan of the distributed channel of the DRU.

20. In a processing device configured to control a station (STA) in a wireless local area network (WLAN) system, the processing device: one or more processors; and A processing device comprising one or more computer memories operatively connected to said one or more processors and storing instructions that, when executed by said one or more processors, perform a method according to any one of claims 1 to 16.

21. One or more non-transitory computer-readable media storing one or more instructions, A computer-readable medium, wherein the one or more commands are executed by one or more processors to control a device in a wireless LAN system to perform a method according to any one of claims 1 to 16.

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