Method and device for performing uplink transmission / reception operation on basis of trigger frame in wireless LAN system

Abstract

Disclosed are a method and device for operating in a wireless LAN system. The method according to an embodiment of the present disclosure comprises the steps in which: a first station (STA) receives a trigger frame including a field from a second STA; and the first STA decodes the trigger frame, wherein a padding field includes a common control subfield and an intermediate frame check sequence (FCS) subfield, and the common control subfield may include a first subfield related to whether at least one of a per-feature information subfield or a security information subfield is included in the padding field.

Description

Method and device for performing uplink transmission and reception operations based on trigger frames in a wireless LAN system

[0001] The present disclosure relates to a method and apparatus for performing uplink transmission and reception operations based on a trigger frame 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 a method and apparatus for transmitting and receiving traffic in a wireless LAN system.

[0005] The technical problem of the present disclosure is to a method and apparatus for performing uplink transmission and reception operations based on a trigger frame containing an intermediate FCS field in a wireless LAN system.

[0006] The technical problems to be solved in this disclosure are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this disclosure belongs from the description below.

[0007] A method according to one embodiment of the present disclosure comprises the steps of: receiving, by a first station (STA), a trigger frame including a padding field from a second STA; decoding, by the first STA, the trigger frame, wherein the padding field includes a common control subfield and an intermediate frame check sequence (FCS) subfield, and wherein the common control subfield may include a first subfield related to whether at least one of a per feature information subfield or a security subfield is included in the padding field.

[0008] A method according to one embodiment of the present disclosure comprises the steps of: generating, by a second station (STA), a trigger frame including a padding field; transmitting, by the second STA, the trigger frame to the first STA, wherein the padding field includes a common control subfield and an intermediate frame check sequence (FCS) subfield, and wherein the common control subfield may include a first subfield related to whether at least one of a per feature information subfield or a security information subfield is included in the padding field.

[0009] According to various embodiments of the present disclosure, a method and device for transmitting and receiving traffic in a wireless LAN system can be provided.

[0010] According to various embodiments of the present disclosure, a method and device for performing an uplink transmission and reception operation based on a trigger frame including an intermediate FCS field in a wireless LAN system can be provided.

[0011] 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.

[0012] 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.

[0013] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0014] FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0015] FIG. 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

[0016] FIG. 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0017] FIG. 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0018] 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.

[0019] FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0020] FIG. 8 is a drawing showing an exemplary format of a trigger frame to which the present disclosure can be applied.

[0021] FIG. 9 is a flowchart for explaining the operation of the first STA according to one embodiment of the present disclosure.

[0022] FIG. 10 is a flowchart for explaining the operation of a second STA according to one embodiment of the present disclosure.

[0023] FIG. 11 is a diagram for explaining the configuration of a trigger frame including an intermediate FCS and the operation of an STA supporting DPS according to one embodiment of the present disclosure.

[0024] FIG. 12 is a diagram for explaining the operation of an STA supporting DSO according to one embodiment of the present disclosure.

[0025] FIG. 13 is a diagram for explaining the operation of an STA that supports integrity check of a trigger frame according to one embodiment of the present disclosure.

[0026] FIG. 14 is a diagram for explaining the configuration of an intermediate FCS field and a padding field according to one embodiment of the present disclosure.

[0027] 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.

[0028] 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.

[0029] In the present disclosure, when a component is described as being “connected,” “combined,” or “joined” with another component, this may include not only a direct connection but also an indirect connection in which another component exists between them. Furthermore, in the present disclosure, the terms “comprising” or “having” specify the presence of the mentioned features, steps, actions, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, actions, elements, components, and / or groups thereof.

[0030] 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.

[0031] The terms used in this disclosure are for the description of specific embodiments and are not intended to limit the claims. As used in the description of embodiments and in the appended claims, the singular form is intended to include the plural form unless the context clearly indicates otherwise. The term "and / or" as used in this disclosure may refer to any one of the related enumerated items, or refers to and includes any and all possible combinations of two or more of them. Additionally, the " / " between words in this disclosure has the same meaning as "and / or" unless otherwise noted.

[0032] 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.

[0033] Below, technical features to which examples of the present disclosure can be applied are described.

[0034] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0035] 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.

[0036] 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.

[0037] 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) may include interfaces for the medium access control (MAC) layer and the physical layer (PHY) that comply with the specifications of the IEEE 802.11 standard.

[0038] 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).

[0039] The first device (100) includes one or more processors (102) and one or more memories (104), and may additionally include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memory (104) and / or transceivers (106) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or sequences of operation disclosed in this disclosure. For example, the processor (102) may process information within the memory (104) to generate a first information / signal and then transmit a wireless signal containing the first information / signal through the transceiver (106). Additionally, the processor (102) may receive a wireless signal containing a second information / signal through the transceiver (106) and then store information obtained from the signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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 the present 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.

[0045] 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. In addition, various information (e.g., information related to fields, subfields, control fields, parameters, power, etc.) used by various STAs for determining / acquiring / configuring / calculating / decoding / encoding transmission and reception signals in the following example can be stored in the memory (104, 204) of FIG. 1.

[0046] 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.

[0047] FIG. 2 is a drawing showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0048] The structure of a wireless LAN system can be composed of multiple components. Through the interaction of multiple components, a wireless LAN that supports STA mobility transparent to the upper layer can be provided. A Basic Service Set (BSS) corresponds to the basic building block of a wireless LAN. Figure 2 exemplarily illustrates 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). In Figure 2, the ellipse representing the BSS can also be understood as representing the coverage area where the STAs included in the corresponding BSS maintain communication. This area can be referred to as a Basic Service Area (BSA). If a STA moves outside the BSA, it becomes unable to communicate directly with other STAs within that BSA.

[0049] Excluding the DS illustrated in Fig. 2, the most basic type of BSS in a wireless LAN is the Independent BSS (IBSS). For example, an IBSS can have a minimal form consisting of only two STAs. For instance, assuming other components are omitted, a BSS1 composed of only STA1 and STA2, or a BSS2 composed of only STA3 and STA4, can each be considered a representative example of an IBSS. Such a configuration is possible when the STAs can communicate directly without an AP. Furthermore, this type of wireless LAN is not configured through pre-planning but can be configured when a LAN is needed, and this can be referred to as an ad-hoc network. Since an IBSS does not include an AP, there is no centralized management entity. In other words, 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.

[0050] 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).

[0051] 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.

[0052] 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.

[0053] 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).

[0054] 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.

[0055] Data transmitted from one of the STA(s) associated with an AP to the STA address of that AP is always received on an uncontrolled port and can be processed by an IEEE 802.1X port access entity. In addition, if the controlled port is authenticated, the transmitted data (or frame) can be forwarded to the DS.

[0056] In addition to the structure of the DS described above, an extended service set (ESS) may be established to provide wider coverage.

[0057] An ESS refers to a network of arbitrary size and complexity composed of DSs and BSSs. An ESS can correspond to a set of BSSs connected to a single DS. However, an ESS does not contain a DS. An ESS network is characterized by appearing as an IBSS at the Logical Link Control (LLC) layer. STAs included in 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 included in a single ESS can have the same Service Set Identification (SSID). The SSID is distinct from the BSSID, which is the identifier for the BSS.

[0058] 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.

[0059] FIG. 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

[0060] In order 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 go through authentication procedures for security. The link setup process can also be referred to as the session initiation process or the session setup process. Additionally, the processes of discovery, authentication, association, and security setup in the link setup process can be collectively referred to as the association process.

[0061] In step S310, the STA may perform a network discovery operation. The network discovery operation may include the STA's scanning operation. That is, in order for the STA to access a network, it must find a network it can join. Before joining a wireless network, the STA must identify a compatible network, and the process of identifying networks existing in a specific area is called scanning.

[0062] Scanning methods include active scanning and passive scanning. Figure 3 illustrates a network discovery operation that includes an active scanning process as an example. In active scanning, the STA performing the scanning moves between channels to search for nearby APs, transmits a probe request frame, and waits for a response. The responder transmits a probe response frame as a response to the probe request frame to the STA that transmitted the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame from the BSS of the channel being scanned. In a BSS, the AP becomes the responder because it transmits the beacon frame; however, in an IBSS, the responder is not constant because STAs within the IBSS take turns transmitting the beacon frame. 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.

[0063] 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. When comparing active scanning and passive scanning, active scanning has the advantage of lower delay and power consumption than passive scanning.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] For example, the association request frame may include information regarding various capabilities, beacon listen interval, service set identifier (SSID), supported rates, supported channels, RSN, mobility domain, supported operating classes, Traffic Indication Map Broadcast request, interworking service capabilities, etc. For example, the association response frame may include information regarding various capabilities, status code, Association ID (AID), supported rates, Enhanced Distributed Channel Access (EDCA) parameter set, Received Channel Power Indicator (RCPI), Received Signal to Noise Indicator (RSNI), mobility domain, timeout interval (e.g., association comeback time), overlapping BSS scan parameters, TIM broadcast response, 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.

[0070] After the STA is successfully joined to the network, a security setup process can be performed in step S340. The security setup process in step S340 may be described as an authentication process through RSNA (Robust Security Network Association) requests / responses, and the authentication process in step S320 may be referred to as the first authentication process, and the security setup process in step S340 may simply be referred to as the authentication process.

[0071] The security setup process of step S340 may include, for example, a private key setup process through a 4-way handshake via an EAPOL (Extensible Authentication Protocol over LAN) frame. Additionally, the security setup process may be performed according to a security method not defined in the IEEE 802.11 standard.

[0072] FIG. 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0073] In wireless LAN systems, the basic access mechanism for MAC (Medium Access Control) is the CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) mechanism. The CSMA / CA mechanism is also known as the Distributed Coordination Function (DCF) of IEEE 802.11 MAC, and it basically 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.

[0074] 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).

[0075] Referring to FIG. 4, the operation based on the random backoff period is described. When a medium in an occupied / busy state changes to an idle state, multiple STAs may attempt to transmit data (or frames). As a measure to minimize collisions, each STA may select a random backoff count and attempt transmission after waiting for the corresponding slot time. The random backoff count has a pseudo-random integer value and can be determined as one of the values ​​in the range from 0 to CW. Here, CW is the Contention Window parameter value. The CW parameter is given an initial value of CWmin, but in the case of transmission failure (e.g., failure to receive an ACK for a transmitted frame), it may take a value twice that amount. When the CW parameter value becomes CWmax, data transmission may be attempted while maintaining the CWmax value until data transmission is successful; if data transmission is successful, it is reset to the CWmin value. The values ​​of CW, CWmin, and CWmax are 2 n It is desirable to set it to -1 (n=0, 1, 2, ...).

[0076] 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.

[0077] 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.

[0078] As shown in the example in Fig. 4, a data frame is a frame used for transmitting data that is forwarded to an upper layer, and can be transmitted after a backoff performed after the elapsed time of DIFS from when the medium becomes idle. Additionally, a management frame is a frame used for exchanging management information that is not forwarded to an upper layer, and is transmitted after a backoff performed after the elapsed time of an IFS such as DIFS or PIFS (Point coordination function IFS). Subtypes of management frames include Beacon, Association request / response, re-association request / response, probe request / response, and authentication request / response. A control frame is a frame used to control access to the medium. Subtype frames of control frames include RTS (Request-To-Send), CTS (Clear-To-Send), ACK (Acknowledgment), PS-Poll (Power Save-Poll), Block ACK (BlockAck), Block ACK Request (BlockACKReq), NDP Announcement (null data packet announcement), and Trigger. If a control frame is not an acknowledgment frame of a previous frame, it is transmitted after a backoff performed after the elapsed DIFS; if it is an acknowledgment frame of a previous frame, it is transmitted after the elapsed SIFS (short IFS) without a backoff. The type and subtype of a frame can be identified by the type field and subtype field within the Frame Control (FC) field.

[0079] 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.

[0080] FIG. 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] If STA1 receives a CTS frame from STA2, it may transmit a data frame to STA2 after SIFS from the time the reception of the CTS frame is completed. If STA2 successfully receives the data frame, it may transmit an ACK frame to STA1 as an acknowledgment to the data frame after SIFS. STA3 may determine whether the channel is in use through carrier sensing when the NAV timer expires. If STA3 determines that the channel is not in use by another terminal during DIFS from the time the NAV timer expires, it may attempt channel access after a contention window (CW) based on random backoff has passed.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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. In addition, depending on the type of PPDU format (e.g., HT-mixed format PPDU, HT-greenfield format PPDU, VHT (Very High Throughput) PPDU, etc.), additional (or other types of) RL-SIG, U-SIG, non-legacy SIG fields, non-legacy STF, non-legacy LTF, (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)) may be included between the L-SIG field and the data field. More specific details will be described later with reference to FIG. 7.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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).

[0098] FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0099] Various forms of PPDU have been used in standards such as IEEE 802.11a / g / n / ac / ax. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and Data fields. The basic PPDU format may also be referred to as the non-HT PPDU format (Fig. 7(a)).

[0100] 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).

[0101] 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)).

[0102] 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 PPDU format for single users (SUs) does not include the HE-SIG-B. 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 8us. 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 may vary to 16us. For example, RL-SIG can be configured identically to 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 RL-SIG.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal SIGNAL), and EHT-SIG fields can be encoded and modulated so that demodulation and decoding can be attempted even on legacy STAs, and mapped based on a defined 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 a STA that has successfully decoded a non-legacy SIG (e.g., U-SIG and / or EHT-SIG) to obtain the information contained in the corresponding fields, and mapped based on a defined subcarrier frequency interval (e.g., 78.125 kHz). These can be referred to as EHT modulated fields.

[0107] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields can be referred to as pre-HE modulation fields, and the HE-STF, HE-LTF, Data, and PE fields can be referred to as HE modulation fields. Also, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields can be referred to as pre-VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and Data fields can be referred to as VHT modulation fields.

[0108] The U-SIG included in the EHT PPDU format of FIG. 7 can be constructed based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol for the U-SIG (e.g., OFDM symbol) can have a duration of 4 µs, and the U-SIG can have a total duration of 8 µs. Each symbol of the U-SIG can be used to transmit 26 bits of information. For example, each symbol of the U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.).

[0115] 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.

[0116] Some of the information required for PPDU transmission and reception may be included in U-SIG and / or non-legacy SIGs (e.g., EHT-SIG or UHR-SIG, etc.). For example, information regarding the type of non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information regarding the length of non-legacy LTF and cyclic prefix (CP) length, information regarding guard interval (GI) applied to non-legacy LTF, information regarding preamble puncturing applicable to PPDU, information regarding resource unit (RU) allocation, etc., may be included only in U-SIG, may be included only in non-legacy SIG, or may be indicated by a combination of information included in U-SIG and information included in non-legacy SIG.

[0117] 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.

[0118] 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.).

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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, 3X996-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.

[0126] The specific size of the RU may be reduced or expanded. Accordingly, the specific size of each RU (i.e., the number of corresponding tones) in this disclosure is not limited and is exemplary. Additionally, within a given bandwidth (e.g., 20, 40, 80, 160, 320 MHz, ...) in this disclosure, the number of RUs may vary depending on the RU size.

[0127] 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.

[0128] FIG. 8 is a drawing showing an exemplary format of a trigger frame to which the present disclosure can be applied.

[0129] 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.

[0130] The common information field may include information commonly applicable to one or more TB PPDU transmissions requested by a trigger frame, such as trigger type, UL length, whether a subsequent trigger frame exists (e.g., More TF), whether a CS (channel sensing) is required, UL BW (bandwidth), etc. FIG. 8 illustrates an exemplary format for the common information field of an EHT variant.

[0131] The 4-bit trigger type subfield can have values ​​from 0 to 15. Among these, the values ​​0, 1, 2, 3, 4, 5, 6, and 7 of the trigger type subfield are defined to correspond to basic, BFRP (Beamforming Report Poll), MU-BAR (multi-user-block acknowledgement request), MU-RTS (multi-user-request to send), BSRP (Buffer Status Report Poll), GCR (groupcast with retries) MU-BAR, BQRP (Bandwidth Query Report Poll), and NFRP (NDP Feedback Report Poll), respectively, and the values ​​8 to 15 are defined as reserved.

[0132] Among the common information, the trigger dependent common info subfield may include information that is optionally included based on the trigger type.

[0133] 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.

[0134] A user information list contains zero or more user information fields. Figure 8 illustrates an example of an EHT variant user information field format.

[0135] 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.

[0136] The RU allocation subfield can indicate the size and location of the RU / MRU. To this end, the RU allocation subfield may be interpreted together with the PS160 (primary / secondary 160MHz) subfield of the user information field, the UL BW subfield of the common information field, etc.

[0137] FCS Field

[0138] The FCS field may contain a 32-bit CRC. The FCS field value may be calculated across the entire field of the MAC header and the frame body field. The field(s) described above may also be represented as a calculation field. The FCS field value is the following 32nd-order standard generating polynomial (e.g., x 32 + x 26 + x 23 + x 22 + x 16 + x 12 + x 11 + x 10 + x 9 + x 7 + x 5 + x 4 + x 2 + x 1It can be calculated using + 1).

[0139] The FCS field value can be the one's complement (modulo 2) of the following sum:

[0140] a) x k (x 31 + x 30 + x 29 + ... + x 2 + x 1 + 1) is the remainder (modulo 2) divided by G(x), where k represents the number of bits in the computation field; and

[0141] b) The contents of the calculated field (processed as a polynomial) x 32 It is the remainder after multiplying by and dividing by G(x).

[0142] The FCS field can be transmitted starting with the coefficient of the highest order term. In a typical implementation, the transmitter can pre-set the initial remainders of the division to all 1s and then modify the calculation field by dividing it by the generating polynomial G(x). The one's complement of this remainder can be transmitted as the FCS field with the most significant bit coming first.

[0143] At the receiver, the initial remainders are all preset to 1, and the serial receive bits of the compute field and FCS can generate a unique non-zero remainder value when divided by G(x) (assuming there are no transmission errors). The unique remainder value can be the following polynomial:

[0144] x 31 + x 30 + x 26 + x 25 + x 24 + x 18 + x 15 + x 14 + x 12 + x 11 + x 10 + x 8 + x 6 + x 5 + x 4 + x 3 + x + 1.

[0145] Uplink transmission procedure based on trigger frame

[0146] A padding field may be optionally included within the trigger frame described with reference to FIG. 8, and the length of the trigger frame may be extended accordingly. For example, if a padding field is included within the trigger frame, the padding field (e.g., time secured through the padding field) may provide time for the STA that receives the trigger frame to prepare UL MU data to transmit (e.g., PPDU to transmit after SIFS after receiving the trigger frame).

[0147] For example, the value of the AID12 subfield located at the beginning of the padding field can be set to 4095 so that an STA receiving a trigger frame can recognize the padding field after the user information list field within the padding field of the trigger frame. That is, the initial 2-octet value of the padding field can be set to 1.

[0148] In a basic wireless LAN system, a receiving STA (e.g., EHT STA) can perform an FCS check operation (e.g., a Cyclic Redundancy Check (CRC) based operation) based on the value of the FCS field placed after the padding field of the trigger frame. Afterward, the receiving STA can send a PPDU based on the trigger frame to the transmitting STA that sent the trigger frame.

[0149] An STA that intends to perform other operations, including the generation / preparation of UL MU data, within the time corresponding to the padding field must verify that the trigger frame is a successful frame based on the FCS field of the trigger frame. However, as described above, in a basic wireless LAN system, the FCS field is placed after the padding field within the trigger frame. That is, since the FCS check operation is not performed within the time interval corresponding to the padding field, the STA may not be able to perform other operations within that time interval.

[0150] Accordingly, there was a problem that the location of the FCS field on the basic wireless LAN system was inefficient for STAs supporting DPS (dynamic power save), integrity check for control frames, DSO (dynamic Subband operation), or / and DUO (dynamic unavailability operation) mode.

[0151] Below, we will specifically describe the procedures and parameters related to the new FCS (sub)field placed before the padding field within the trigger frame.

[0152] In describing the present disclosure, a new FCS (sub-field) may be expressed as, but is not limited to, an intermediate FCS (sub-)field, an IFCS (sub-)field, an FCS 2 (sub-)field, a pre-FCS (sub-)field, an extra FCS (sub-)field, a post FCS (sub-)field, etc.

[0153] The values, names, (sub)field locations / names, etc. described / suggested within the present disclosure may be changed and are not limited thereto. In addition, STAs may include non-AP STAs or AP STAs, etc. In addition, in describing the present disclosure, it is assumed, but not limited thereto, that UHR STAs are STAs that support DPS, integrity check for control frames (e.g., trigger frames), DSO and / or DUO mode, etc.

[0154] Additionally, in describing the present disclosure, a trigger frame supporting DPS, integrity checks for control frames, DSO and / or DUO modes, etc. may include the (sub)fields and / or new FCS (sub)fields shown in FIG. 8.

[0155] FIG. 9 is a flowchart illustrating the operation of a first STA according to one embodiment of the present disclosure. In FIG. 9 and FIG. 10, the first STA and the second STA may each be either a non-AP STA or an AP. That is, in the present disclosure, the STA may include a non-AP STA (MLD) and an AP STA (MLD).

[0156] In addition, in FIGS. 9 and 10, it is assumed, but not limited to, that the first STA or / and the second STA are STAs (e.g., UHR STAs) that support DPS, integrity check for control frames (e.g., trigger frames), DSO, and / or DUO mode. In addition, in describing the present disclosure, it is assumed, but not limited to, that the UHR STA(s) that include new information in the padding field of the trigger frame are STA(s) that support DPS, integrity check for trigger frames, DSO, DUO mode (or IDC), NPCA (non-primary channel access), and / or multi-AP coordination. In addition, the positions of values / names / (sub)field(s) described in the present disclosure may be changed, and are not limited thereto.

[0157] The first STA can receive a trigger frame including a padding field from the second STA (S910).

[0158] In describing the present disclosure, a trigger frame may include a common information field, a user information field, a padding field, and / or an FCS field. In addition, the padding field may include at least one of an association identifier (AID) 12 subfield, a common control subfield, a feature-specific information subfield, a security information subfield, and an intermediate FCS subfield.

[0159] An intermediate FCS value may be set on the intermediate FCS subfield, and the length of the intermediate FCS subfield may be 32 bits, but is not limited thereto. Also, the intermediate FCS subfield may be placed before a fourth subfield (e.g., padding subfield) in which a padding value is set within the padding field.

[0160] As an example of the present disclosure, the length of the padding field may be based on a dynamic power save (DPS) padding delay field. Specifically, the length of the padding field may be determined based on a largest value among a value of the DPS padding delay field, a time for processing a trigger frame (or a time value required to generate a PPDU / data corresponding to the trigger frame (“MinTrigProcTime”)), and a padding delay value associated with an enhanced multi-link single radio (EMLSR) or an enhanced multi-link multi-radio (EMLMR).

[0161] For example, the padding field may include additional 4 bits adjacent to the AID12 subfield. The AID12 subfield and the additional 4 bits may both be set to 1. That is, the first STA may identify that it has reached the padding field within the trigger frame by decoding the AID12 subfield set to 4096 and the additional 4 bits set to 1. However, this is only one embodiment, and the additional 4 bits may not be present.

[0162] For example, the common control subfield and the feature-specific information subfield may be located within the trigger frame following the AID12 subfield and an additional 4 bits.

[0163] And, as an example of the present disclosure, the length of the padding field may be determined to be equal to or greater than the largest value among the value of the DPS padding delay field, the time for processing the trigger frame, and the padding delay value associated with EMLSR or EMLMR.

[0164] For example, the common information field or the common control subfield may include a second subfield that is related to whether the middle FCS subfield is present on the trigger frame (e.g., a padding field). For example, if the second subfield value is set to a first number (e.g., 1 or 0), this may indicate that the middle FCS subfield is present on the trigger frame (e.g., a padding field). As another example, if the second subfield value is set to a second number (e.g., 0 or 1), this may indicate that the middle FCS subfield is not present on the trigger frame (e.g., a padding field).

[0165] As an example of the present disclosure, the common control subfield may include a first subfield related to whether at least one of a per feature information subfield or a security subfield is included within the padding field. That is, whether the per feature information subfield and / or the security subfield is included within the padding field may be indicated by the first subfield. However, this is only one embodiment, and the common control subfield may include separate subfields related to whether each of the per feature information subfield and the security subfield is present on the padding field.

[0166] For example, a message integrity code (MIC) value for integrity check or / and security may be included in a security information subfield. Also, a packet number (PN) and a key identifier (ID), each may be included in a security information subfield or a feature-specific information subfield.

[0167] For example, the key ID is used for integrity check of the trigger frame, and the key ID may be set on at least one bit of the common control subfield or the special user information field of the trigger frame. For example, the key ID may be set on at least one of the reserved bits of the common control subfield. As another example, the key ID may be set on at least one of the reserved bits of the special user information field (e.g., the 38th bit to the 40th bit, etc.).

[0168] For example, the feature-specific information subfield may include information related to at least one of a dynamic power save (DPS) (e.g., an operation to switch from a first capability bandwidth to a second capability bandwidth), an integrity check for a control frame, a dynamic subband operation (DSO), an operation for a dynamic unavailability operation (DUO) mode (e.g., an operation to switch from a primary channel to a secondary channel), non-primary channel access, or multi-access point (AP) coordination.

[0169] In addition, the common control subfield may include a third subfield related to whether each of the following is included in the feature-specific information subfield: DPS, integrity check for control frames, DSO, operation for DUO mode, non-primary channel access, or multi-AP coordination. That is, through the third subfield, the type of one or more unit operations included in the feature-specific information subfield can be identified. For example, the third subfield may include a bitmap, etc., indicating whether information for each of the aforementioned operations is included in the feature-specific information subfield.

[0170] The first STA can decode the trigger frame (S920).

[0171] In one example of the present disclosure, a first STA can identify that it is decoding a padding field within a trigger frame through an AID12 subfield where all values ​​are set to 1. For example, if an additional 4 bits are connected to the AID12 subfield, the first STA can identify that an intermediate FCS field exists after the additional 4 bits. If no additional 4 bits exist, the first STA can identify that an intermediate FCS field exists after the AID12 subfield.

[0172] The first STA can perform an FCS check operation based on an intermediate FCS field. If the FCS check operation is successful, the first STA can perform at least one operation based on a feature-specific information subfield during a time interval corresponding to the fourth subfield (e.g., a time interval corresponding to the padding subfield). Here, the at least one operation may correspond to the type of information included in the feature-specific information subfield.

[0173] For example, the first STA can perform at least one of DPS, integrity check for control frames, DSO, DUO mode, non-primary channel access, or multi-AP coordination based on a feature-specific information subfield within a time interval corresponding to a padding value included / set in the fourth subfield.

[0174] For example, if DPS-related information is included in the feature-specific information subfield, the first STA can perform an operation of switching from the first capability bandwidth (or primary channel) to the second capability bandwidth (or secondary channel).

[0175] Specifically, the first STA may receive a trigger frame in the first capability bandwidth (or primary channel). The first STA may switch from the first capability bandwidth to the second capability bandwidth (or secondary channel) during a padding time and perform UL data transmission operations, etc., in the second capability bandwidth (or secondary channel). The first capability bandwidth may be lower than the second capability bandwidth.

[0176] Additionally or alternatively, if the FCS check operation based on the intermediate FCS field is successful, the first STA may generate the PPDU requested by the trigger frame and transmit the PPDU to the second STA.

[0177] For example, if the FCS check operation based on the intermediate FCS field is successful, the first STA may not perform the FCS check operation on the FCS field placed after the padding field within the trigger frame. If the FCS check operation based on the intermediate FCS field is unsuccessful, the first STA may perform the FCS check operation through the FCS field placed after the padding field within the trigger frame.

[0178] The method described in the example of FIG. 9 can 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 can receive a trigger frame including a padding field from the second STA through one or more transceivers (106). One or more processors (102) can decode the trigger frame.

[0179] Furthermore, one or more memories (104) of the first device (100) may store instructions for performing the method described in the example of FIG. 9 or the examples described below when executed by one or more processors (102).

[0180] FIG. 10 is a flowchart for explaining the operation of a second STA according to one embodiment of the present disclosure.

[0181] The second STA can generate a trigger frame including a padding field (S1010).

[0182] As described above, the trigger frame generated by the second STA may include a common information field, a user information field, a padding field, and an FCS field. In addition, the padding field of the trigger frame may include at least one of a common control subfield, an intermediate FCS (sub)field, a feature-specific information subfield, or a security information subfield.

[0183] Prior to step S1010, the second STA may determine whether the first STA supports a DPS operation, a DUO mode (or IDC) related operation, an integrity check operation for the trigger frame, a DSO operation, an NPCA related operation, and / or a multi-AP coordination related operation (during the padding time) of the trigger frame. For example, the second STA may receive capability information from the first STA related to whether the second STA supports a DPS operation, a DUO mode (or IDC) related operation, an integrity check operation for the trigger frame, a DSO operation, an NPCA related operation, and / or a multi-AP coordination related operation (during the padding time).

[0184] In the following, it is assumed that the first STA supports DPS operations (during padding time) of the trigger frame, DUO mode (or IDC) related operations, integrity check operations for the trigger frame, DSO operations, NPCA related operations and / or multi-AP coordination related operations, but is not limited thereto.

[0185] The second STA can transmit a trigger frame to the first STA (S1020).

[0186] That is, the second STA can generate a trigger frame containing a padding field containing an intermediate FCS field and then transmit it to the first STA. Since the configuration of the trigger frame has been explained with reference to FIG. 9, a redundant explanation will be omitted.

[0187] As described above, the first STA may perform an FCS check operation through the intermediate FCS field. If the FCS check operation is successful, the first STA may perform a DPS operation, a DUO mode (or IDC) related operation, an integrity check operation for a trigger frame, a DSO operation, an NPCA related operation, and / or a multi-AP coordination related operation during a time corresponding to the padding field (e.g., a time corresponding to the fourth subfield in which the padding value included in the padding field is set).

[0188] And, the second STA can receive a response frame (e.g., the second frame) requested / triggered by the trigger frame from the first STA.

[0189] The method described in the example of FIG. 10 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 generate a trigger frame including a padding field. The one or more processors (202) may transmit the trigger frame to the first STA via one or more transceivers (206).

[0190] Furthermore, one or more memories (204) of the second device (200) may store instructions for performing the method described in the example of FIG. 10 or the examples described below when executed by one or more processors (202).

[0191] Below, we will describe in detail the operation based on the intermediate FCS field, the configuration of the intermediate FCS field, the configuration of the trigger frame including the intermediate FCS field, and the method for determining the length of the padding field within the trigger frame. In addition, we will describe the method for positioning information(s) for the operation(s) requiring the performance of the intermediate FCS field-based FCS check within the padding field of the trigger frame together with a new FCS (sub)field.

[0192] Example 1

[0193] Example 1 relates to an operation based on an intermediate FCS (sub)field.

[0194] As an example of the present disclosure, if an intermediate FCS (sub)field is included before a padding field of a trigger frame, an STA supporting DPS (e.g., a UHR STA) may perform an FCS check operation based on the intermediate FCS field. In addition, the STA may perform an operation of switching from a low capability bandwidth (e.g., 20 MHz) to a high capability bandwidth (e.g., 80 MHz) during a padding time of the padding field of the trigger frame (e.g., a time period corresponding to the padding field).

[0195] For example, as illustrated in (a) of FIG. 11, the STA may operate in a low capability bandwidth and mode (e.g., listening mode) while decoding the frame control field of the trigger frame to the middle FCS field. After performing an FCS check based on the middle FCS field, the STA may switch the listening mode to a mode associated with a high capability bandwidth (e.g., power mode) during the padding time of the padding field. Accordingly, the STA may perform an operation of checking CCA based on SIFS on the TXOP bandwidth, as illustrated in (b) of FIG. 11.

[0196] Specifically, as illustrated in (b) of FIG. 11, a receiving STA (e.g., a DPS-enabled STA) may receive an MU-RTS frame (e.g., an initial control frame (ICF)) from a transmitting STA (e.g., a DPS-supporting STA). At this time, the mode of the receiving STA may be a listening mode, and the listening mode may collectively refer to a mode capable of performing (receiving) capability-based operations related to a low bandwidth (e.g., 20 MHz).

[0197] A receiving STA may switch from a listening mode to a power mode during the padding time of the padding field of an MU-RTS frame, and may transmit a CTS frame (e.g., an initial control response (ICR)) to the transmitting STA as a response to the MU-RTS frame within the power mode. Here, the power mode may collectively refer to a mode capable of performing (receiving) capability-based operations related to a high bandwidth (e.g., 80 MHz).

[0198] Additionally or alternatively, as illustrated in FIG. 12, assume that a middle FCS (sub)field is included before the padding field of the trigger frame. A DSO-enabled STA (e.g., a UHR STA) may perform an FCS check operation based on the middle FCS field of a trigger frame (e.g., a BSRP frame or ICF) transmitted by a DSO-enabled STA. In this case, the trigger frame may be transmitted and received on the primary 80 MHz and the secondary 80 MHz.

[0199] In addition, a DSO-enabled STA can perform an operation of switching from the primary 80 MHz to the secondary 80 MHz during the padding time of the padding field. Accordingly, the DSO-enabled STA can transmit a response frame (e.g., BSR or ICR) to a DSO-supporting STA on the secondary 80 MHz, and the primary 80 MHz can be used for data transmission of other STAs (which do not support DSO).

[0200] Additionally or alternatively, as illustrated in FIG. 13, if information(s) for checking the integrity of the trigger frame (e.g., key ID, MIC, PN, etc.) and an intermediate FCS (sub)field exist prior to the padding field of the trigger frame, the STA (e.g., receiving STA) can perform an FCS check through the intermediate FCS (sub)field. Then, the STA can verify the validity of the information for checking the integrity of the trigger frame and / or perform an operation to generate / prepare UL MU data based on the trigger frame during the padding time of the padding field.

[0201] Additionally or alternatively, if an intermediate FCS (sub)field of a trigger frame exists prior to the padding field of a trigger frame (e.g., a BSRP trigger frame, etc.), an STA (e.g., an STA supporting DUO) can perform an FCS check through the intermediate FCS (sub)field. Then, the STA can perform DUO-related operations during the padding time of the padding field.

[0202] Here, DUO mode may refer to a mode in which wireless LAN signals / data cannot be transmitted due to transmission / reception operations based on non-Wi-Fi technology (e.g., Bluetooth (BT), Zigbee, UWB (Ultra-wideband), etc.). DUO-related operations may include encoding / decoding of information related to DUO mode / events, signaling of information related to DUO mode / events, etc.

[0203] Example 2

[0204] Embodiment 2 relates to a method for indicating the presence or absence of a new FCS (sub)field (or, intermediate FCS field) in a trigger frame. As described above, a trigger frame supporting DPS, integrity check for trigger frames, DSO, operations related to DUO mode (e.g., IDC), NPCA and / or multi-AP coordination, etc., may include field(s) and / or a new FCS (sub)field for supporting the operations described above.

[0205] An STA (e.g., UHR STA) can check for the presence of an intermediate FCS (sub)field within a trigger frame through the value of the intermediate FCS present subfield. That is, the intermediate FCS present subfield can indicate whether an intermediate FCS (sub)field exists / is placed before the padding field within the trigger frame.

[0206] For example, the intermediate FCS presence subfield may be set / defined via a reserved subfield within the trigger frame. For example, the intermediate FCS presence subfield may be set / defined on at least one bit among the 23rd bit (B22), the 27th bit (B26), the 54th bit (B54), and the 64th bit (B63) of the common information field of the trigger frame. As another example, the intermediate FCS presence subfield may be set / defined on at least one bit among the reserved bits (e.g., the 38th bit (B37) to the 40th bit (B39)) within the special user information field of the trigger frame.

[0207] Example 3

[0208] Example 3 relates to a method for setting the value of a new FCS (sub)field. The method and length of configuring the new FCS (sub)field described in this disclosure may be the same as the method and length of configuring the value of the FCS field included at the end of the MPDU configuration of a basic wireless LAN.

[0209] That is, the value of the intermediate FCS (sub)field can be set as a value for the CRC for the parts corresponding to the MPDU's MAC header and frame body. For example, the intermediate FCS (sub)field is CRC-32 (e.g., x 32 + x 26 + x 23 + x 22 + x 16 + x 12 + x 11 + x 10 + x 9 + x 7 + x 5 + x 4 + x 2 + x 1 It can be calculated based on + 1) and may have a length of 4 octets (e.g., 32 bits). The present disclosure is described below assuming that the configuration of the intermediate FCS (sub)field and the length of the value are 4 octets, but is not limited thereto.

[0210] Additionally or alternatively, the method and length of configuring the new FCS (sub)field may not be the same as the method and length of configuring the FCS field included at the end of the MPDU configuration of the basic wireless LAN system. That is, the value of the intermediate FCS (sub)field may be set as a value for the CRC for the portion corresponding to the MAC header and frame body of the MPDU. In this case, the intermediate FCS (sub)field may be configured based on an N-bit CRC shorter than 32 bits, rather than CRC-32. Here, N may be 24, 16, 8, or 4, but is not limited thereto. The intermediate FCS (sub)field value for the CRC for the MAC header and frame body within the trigger frame may be calculated according to Example 3-1.

[0211] Additionally or alternatively, depending on the N-bit value including 32 bits, reserved bits or / and bits indicating additional information may be used to match the length of the intermediate FCS (sub)field to the length of the octet or the length of the FCS field of the underlying wireless LAN system.

[0212] Example 3-1

[0213] Example 3-1 relates to a CRC-N polynomial associated with an intermediate FCS (sub)field. Here, N can be 24 bits, 21 bits, 17 bits, 16 bits, 15 bits, 14 bits, 13 bits, 12 bits, 11 bits, 10 bits, 8 bits, 7 bits, 6 bits, 5 bits, 4 bits, 3 bits, or 1 bit.

[0214] For example, if N is 24 bits, the value of the intermediate FCS (sub)field can be calculated based on CRC-24, or CRC-24-Radix-64, CRC-24-WCDMA, etc.:

[0215] - CRC-24 : x 24 + x 22 + x 20 + x 19 + x 18 + x 16 + x 14 + x 13 + x 11 + x 10 + x 8 + x 7 + x 6 + x 3 + x 1 + 1

[0216] - CRC-24-Radix-64: x 24 + x 23 + x 18 + x 17 + x 14 + x 11 + x 10 + x 7 + x 6 + x 5 + x4 + x 3 + x 1 + 1

[0217] - CRC-24-WCDMA : x 24 + x 23 + x 6 + x 5 + 1

[0218] As another example, when N is 21 bits, the value of the intermediate FCS (sub)field can be calculated based on CRC-21-CAN, etc.

[0219] As another example, when N is 17 bits, the value of the intermediate FCS (sub)field can be calculated based on CRC-17-CAN, etc.

[0220] As another example, if N is 16 bits, the intermediate FCS (sub)field value can be derived based on CRC-16-Chakravarty, CRC-16-CCITT, CRC-16-CDMA2000, CRC-16-DECT, CRC-16-T10-DIF, CRC-16-DNP, CRC-16-IBM, CRC-16-OpenSafety-A, CRC-16-OpenSafety-B, CRC-16-Profibus, or Fletcher-16 (e.g., Fletcher's checksum):

[0221] CRC-16-DECT : x 16 + x 10 + x 8 + x 7 + x 3 + 1;

[0222] CRC-16-T10-DIF : x 16 + x 15 + x 11 + x 9 + x 8 + x 7 + x 5 + x 4 + x 2 + x 1 + 1;

[0223] CRC-16-DNP : x16 + x 13 + x 12 + x 11 + x 10 + x 8 + x 6 + x 5 + x 2 + 1

[0224] CRC-16-IBM: x 16 + x 15 + x 2 + x 1

[0225] As another example, when N is 15 bits, the intermediate FCS (sub)field value can be calculated based on CRC-15-CAN, etc.:

[0226] As another example, if N is 14 bits, the intermediate FCS (sub)field value can be calculated based on CRC-14-GSM or CRC-14-DARC.

[0227] As another example, when N is 13 bits, the intermediate FCS (sub)field value can be calculated based on CRC-13-BBC, etc.:

[0228] CRC-13-BBC : x 13 + x 12 + x 11 + x 10 + x 7 + x 6 + x 5 + x 4 + x 2 + 1.

[0229] As another example, when N is 12 bits, an intermediate FCS (sub)field value can be calculated based on CRC-12, CRC-12-CDMA2000, or CRC-12-GSM, etc.:

[0230] CRC-12 : + x 12 + x 11 + x3+ x 2 + x 1 + 1.

[0231] As another example, if N is 11 bits, the intermediate FCS (sub)field value can be calculated based on CRC-11:

[0232] CRC-11 : x 11 + x 9 + x 8 + x 2 + 1.

[0233] As another example, when N is 10 bits, an intermediate FCS (sub)field value can be calculated based on CRC-10, CRC-CDMA2000, or CRC-10-GSM:

[0234] CRC-10 : x 10 + x 9 + x 5 + x 4 + X 1 + 1.

[0235] As another example, when N is 8 bits, an intermediate FCS (sub)field value can be calculated based on CRC-8, CRC-8-AUTOSAR, CRC-8-CCITT, CRC-8-Dallas / Maxim, CRC-8-DARC, CRC-8-GSM-B, CRC-8-SAEJ1850, or CRC-8-WCDMA:

[0236] CRC-8 : x 8 + x 7 + x 6 + x 4 + x 2 + 1;

[0237] CRC-8-AUTOSAR : x 8 + x 5 + x 3 + x 2 + x 1 + 1;

[0238] CRC-8-Bluetooth: x 8 + x 7 + x 5 + x 2 + x 1 + 1;

[0239] CRC-8-CCITT: x8 + x 2 + x 1 + 1;

[0240] CRC-8-Dallas / Maxim: x 8 + x 5 + x 4 + 1;

[0241] CRC-8-DARC: x 8 + x 5 + x 4 + x 3 + 1;

[0242] CRC-8-GSM-B: x 8 + x 6 + x 3 + 1;

[0243] CRC-8-SAEJ1850: x 8 + x 4 + x 3 + x 2 + 1;

[0244] CRC-8-WCDMA: x 8 + x 7 + x 4 + x 3 + x 1 + 1.

[0245] As another example, if N is 7 bits, the intermediate FCS (sub)field value can be calculated based on CRC-7 or CRC-7-MVB:

[0246] CRC-7 : x 7 + x 3 + 1.

[0247] As another example, when N is 6 bits, an intermediate FCS (sub)field value can be calculated based on CRC-6-CDMA2000-A, CRC-6-CDMA2000-B, CRC-6-GSM, or CRC-6-ITU:

[0248] CRC-6-GSM : x 6 + x 5 + x 3 + x 2 + x 1 + 1;

[0249] CRC-6-ITU: x 6 + x 1 + 1.

[0250] As another example, when N is 5 bits, the intermediate FCS (sub)field value can be calculated based on CRC-5-EPC, CRC-5-ITU, or CRC-5-USB:

[0251] CRC-5-EPC : x 5 + x 3 + 1;

[0252] CRC-5-ITU : x 5 + x 4 + x 2 + 1;

[0253] CRC-5-USB : x 5 + x 2 + 1.

[0254] As another example, when N is 4 bits, the intermediate FCS (sub)field value can be calculated based on CRC-4-ITU:

[0255] CRC-4-ITU : x 4 + x 1 + 1;

[0256] As another example, when N is 3 bits, the intermediate FCS (sub)field value can be calculated based on CRC-3-GSM:

[0257] CRC-3-GSM : x 3 + x 1 + 1;

[0258] As another example, when N is 1 bit, the intermediate FCS (sub)field value can be calculated based on CRC-1:

[0259] CRC-3-GSM : x 1 + 1.

[0260] Example 4

[0261] Example 4 relates to information related to security for integrity checks on trigger frames.

[0262] Each of the transmitting STA(s) and the receiving STA(s) may share with each other whether they support an integrity check for a trigger frame during the discovery process (e.g., the transmission and reception process of a beacon frame or / and probe response frame) and the (re)combination process (e.g., the transmission and reception process of a (re)combination request frame and / or (re)combination response frame).

[0263] For example, information indicating whether an integrity check for a trigger frame is supported can be set through a reserved bit (e.g., the 17th bit (B16) to the 21st bit (B20) or the 23rd bit (B22) or other bits within the extended RSN capability field) in various elements (e.g., RSNXE (robust security network extension element)) included in a beacon frame, a probe response frame, or a (re)join request / response frame.

[0264] Additionally or alternatively, a new protected trigger support (sub)field within a new element may be included on a beacon frame, probe response frame, or (re)combination request / response frame, and the new protected trigger support (sub)field may indicate whether an integrity check for the trigger frame is supported.

[0265] For example, the size of the protected trigger support (sub)field may be 1 bit. If the bit value is set to 1 (or 0), it may indicate that the application of an integrity check to the trigger frame is supported. If the bit value is set to 0 (or 1), it may indicate that the application of an integrity check to the trigger frame is not supported.

[0266] For example, if both the transmitting STA and the receiving STA support the application of integrity checks for trigger frames, both the transmitting STA and the receiving STA may perform integrity check operations for the trigger frames. In addition, if integrity checks for the trigger frames are performed, the transmitting STA and the receiving STA may use a cipher suite (e.g., BIP-GMAC-128, BIP-GMAC-256, or BIP-CMAC-256) of the management frame negotiated during the negotiation process. Additionally or alternatively, the transmitting STA and the receiving STA may negotiate additional cipher suites for the trigger frames.

[0267] Example 4-1

[0268] Example 4-1 relates to a security key for performing an integrity check on a trigger frame.

[0269] In describing the present disclosure, performing an integrity check on a trigger frame can be interpreted / corresponded to extending and applying a BIP (broadcast / multicast integrity protocol) to the trigger frame.

[0270] Here, BIP can provide data integrity and replay protection for group-addressed robust management frames after establishing an integrity group temporal key security association (IGTKSA) and data integrity and replay protection for beacon frames after establishing a beacon integrity group temporal key security association (BIGTKSA). BIP can also provide integrity and replay protection for individually addressed and group-addressed WUR frames.

[0271] For the BIP defined in a basic wireless LAN system, additional details for control frames may be defined, or a separate protocol based on the BIP may be newly defined for checking the integrity of control frames.

[0272] For example, the type of trigger frame being transmitted or received can be indicated by the value of the trigger type subfield included in the common information field of the trigger frame. Depending on the value of the trigger type subfield, it can be indicated whether the trigger frame is an individually addressed frame or a group-addressed frame. Accordingly, when a BIP is applied to a trigger frame, the key used to set the message integrity code (MIC) value can be set / used differently depending on whether it is an individually addressed frame or a group-addressed frame.

[0273] For example, in the case of individually addressed data frames, the MIC value can be calculated using a temporal key (TK) based on a pairwise transient key (PTK) that is identically generated between the transmitting STA and the receiving STA. As another example, in the case of group addressed data frames, the MIC value can be calculated using a temporal key (TK) based on a group temporal key (GTK) shared by the transmitting STA with the receiving STA.

[0274] In basic wireless LAN systems, BIPs based on IGTK (integrity group temporal key) and / or BIGTK (beacon integrity group temporal key) can be utilized. As an example of the present disclosure, a method for utilizing BIPs based on PTK and / or GTK may be applied / possible.

[0275] Below, we will describe options related to the keys used to generate and verify the MIC values ​​of individually addressed trigger frames and group-addressed trigger frames.

[0276] Option 1: Individually addressed trigger frames

[0277] The MIC value can be calculated using a TK based on a PTK that is identically generated during the 4-way handshake process between the transmitting STA and the receiving STA. The corresponding PTK may refer to one of the following:

[0278] - PTK used to encrypt or / and decrypt basic individually addressed data frames;

[0279] - A new PTK for applying security to a control frame (e.g., integrity check / encryption and / or decryption). Here, the new PTK can be represented as a trigger PTK (e.g., TPTK or trigger PTK).

[0280] The receiving STA can perform a MIC check on the received trigger frame using the PTK described above.

[0281] Option 2: Group Addressed Trigger Frame

[0282] The transmitting STA can generate an IGTK or BIGTK during the 4-way handshake process and share it with the receiving STA. Using the TK based on the IGTK or BIGTK, the MIC value can be calculated (by the transmitting STA and / or the receiving STA).

[0283] As another example, the transmitting STA can generate a GTK during the 4-way handshake process and share it with the receiving STA. Using the TK based on the GTK, the MIC value can be calculated (by the transmitting STA or / and the receiving STA).

[0284] As another example, the transmitting STA can generate a group-addressed trigger frame during the 4-way handshake process and then share it with the receiving STA. The MIC value can be calculated (by the transmitting STA or / and the receiving STA) using a TK based on the new GTK.

[0285] Here, the new GTK can be represented as a trigger broadcast GTK (TBGTK), and the sending STA can share the same TBGTK value with the receiving STA(s). That is, the sending STA (e.g., AP) can generate the same TBGTK and share it with the STA(s) associated with it.

[0286] The sending STA may share information related to the TBGTK KDE, a new KDE (Key Data Element) for the TBGTK, the TBGTK, and / or cipher suites that can use the TBGTK, etc., with the receiving STA.

[0287] If the receiving STA receives a key for protection of the trigger frame from the transmitting STA, the receiving STA can perform a MIC check on the received trigger frame using the TBGTK. Otherwise, the receiving STA can perform a MIC check on the received trigger frame based on a key previously shared with the transmitting STA (e.g., IGTK or BIGTK).

[0288] Example 5

[0289] Example 5 relates to a method for performing an integrity check on a trigger frame. That is, a security operation on a trigger frame can be performed in the manner according to Example 5. All situations described below assume a situation in which the transmitting STA(s) and the receiving STA(s) support the use of a trigger frame on a BIP depending on whether they support a protected trigger, and / or a situation in which the configuration method of security information within the trigger frame is shared through the protected trigger mode (sub)field.

[0290] A receiving STA can construct additional authentication data (AAD) for a trigger frame based on information in the MAC header (e.g., frame control field, duration field, RA field, TA field, etc.) of an MPDU received from a transmitting STA. Subsequently, the receiving STA can calculate a MIC based on the MPDU using the AAD. At this time, the receiving STA can obtain the MIC by performing the same process that the transmitting STA used to calculate the MIC based on the MPDU.

[0291] A receiving STA can compare the MIC value derived / obtained with the MIC value transmitted by the transmitting STA. For example, if the MIC value derived / obtained by the receiving STA and the MIC value transmitted by the transmitting STA are the same, the receiving STA can perform an operation based on the acquired MPDU. If the MIC value derived / obtained by the receiving STA and the MIC value transmitted by the transmitting STA are different, the receiving STA can determine that some of the information in the MPDU received from the transmitting STA has been altered by another STA or damaged (during transmission). Therefore, the receiving STA can discard the MPDU.

[0292] Example 6

[0293] Example 6 relates to the format of a trigger frame containing a new information field and an intermediate FCS (sub)field.

[0294] In describing the present disclosure, the novel information may include information for DPS, integrity checks for control frames, DSO, DUO mode (e.g., IDC), NPCA and / or multi-AP coordination, etc. For example, if an intermediate FCS (sub)field exists on a trigger frame, (sub)field(s) containing the novel information to support the above-described operation (e.g., common control field, per-feature information field, and / or security information field) may be positioned before the intermediate FCS (sub)field within the trigger frame.

[0295] The present disclosure illustrates, as shown in FIG. 14(a), cases where new information is included in common control fields and / or feature-specific information fields, but is not limited thereto. As an example, security information and intermediate FCS values ​​among the new information may be included within padding fields of trigger frames. That is, the names and / or configurations of the fields containing the new information may be varied.

[0296] In addition, for describing the present disclosure, variants of trigger frames containing novel information are assumed to correspond to basic, MU-RTS, and BSRP, but are not limited thereto. For example, if a special user information field is included within a basic trigger frame, the trigger-dependent user information field within said special user information field may be set to a reserved value.

[0297] Example 6-1

[0298] Example 6-1 relates to a configuration in which a new information field and an intermediate FCS (sub)field are included within a padding field of a trigger frame.

[0299] In a basic wireless LAN system, if a padding field exists within a trigger frame, the padding field may be located between the last user information field and the FCS field. Additionally, the AID12 subfield value present at the start of the padding field may be set to 4095, and an additional 4 bits set to 1 may be configured. This AID12 subfield and the additional 4 bits may indicate that the padding field begins within the trigger frame. That is, since the AID subfield (e.g., 12 bits) and the additional bits (e.g., 4 bits) are set to 1, the first two octets of the padding field may all be set to 1.

[0300] As an example of the present disclosure, as illustrated in FIG. 14(a), a field(s) for new information and / or an intermediate FCS value may be included between the padding value and two octets (e.g., an AID subfield set to 1 and an additional bit) indicating that the padding field is within the trigger frame.

[0301] Additionally or alternatively, a basic wireless LAN-based STA can identify that a padding field begins within a trigger frame through two octets (e.g., two octets set to 1) indicating / meaning that it is a padding field. Meanwhile, if an intermediate FCS value / field is included within the padding field, four bits set to 1 may not be added to the AID12 subfield set to 4095. That is, four bits may not exist after the AID12 subfield set to 4095, and a field for new information and / or an intermediate FCS (sub)field may be located after the AID12 subfield set to 4095. This may also apply to the method of setting the length of the padding field of a trigger frame containing field(s) and / or an intermediate FCS (sub)field containing new information described in Example 7.

[0302] Additionally or alternatively, the presence or absence of field(s) for new information or / and intermediate FCS value / field in the padding field of the trigger frame (received by UHR STA(s)) may be set / indicated in the manner described in Embodiment 2. As an example, a separate subfield indicating the presence or absence of field(s) for new information or / and intermediate FCS value / field may be included on the trigger frame illustrated in (a) of FIG. 14.

[0303] For example, if the trigger frame includes subfield(s) indicating the presence of field(s) for new information and / or intermediate FCS in the padding field of the trigger frame, the UHR STA can check the presence of field(s) for new information and / or intermediate FCS through the subfield(s).

[0304] For example, as illustrated in (a) of FIG. 14, a common control field, a feature-specific information field, a security information field, and an intermediate FCS field may precede a padding field and an FCS field within a trigger frame, but is not limited thereto.

[0305] Here, the common control field may include information related to whether information related to DPS, IDC, DSO, NPCA and / or multi-AP coordination is included in the feature-specific information field. For example, the common control field may indicate whether information related to DPS, IDC, DSO, NPCA and / or multi-AP coordination is included in the feature-specific information field through a 1-bit subfield related to each of DPS, IDC, DSO, NPCA and / or multi-AP coordination. For example, when the value of the 1-bit subfield is set to 1 (e.g., a value indicating that information related to the operations / features described above is included in the feature-specific information field), information related to the operations / features described above may be included in the feature-specific information field. That is, when the value of the 1-bit subfield related to DPS in the common control field is 1, information related to DPS may be included in the feature-specific information field.

[0306] Additionally or alternatively, the common control field may include a new subfield indicating whether a feature-specific information field and / or a security information field containing information related to performing an integrity check on the trigger frame are present on the trigger frame. That is, the common control field may include a new subfield indicating that information related to an integrity check of the trigger frame follows within the trigger frame.

[0307] As an example of the present disclosure, it is assumed that i) the security information field refers to a field containing the value of MIC for checking the integrity of a trigger frame, and the values ​​of the associated key ID and packet number (PN) are included in the feature-specific information field, and / or ii) the security information field refers to a field containing the values ​​of MIC and PN for checking the integrity of a trigger frame, and the value of the associated key ID is included in the feature-specific information field. In this case, the presence or absence of the feature-specific information field and the security information field containing information for performing an integrity check within the corresponding trigger frame may be indicated through a new subfield (e.g., 1 bit) within the common control field. Additionally or alternatively, the common control field may include a new field of 1 bit indicating the presence or absence of the feature-specific information field containing information for performing an integrity check within the corresponding trigger frame, and a new field of 1 bit indicating the presence or absence of the security information field.

[0308] As an example of the present disclosure, it is assumed that the values ​​of Key ID, PN, and MIC for checking the integrity of a trigger frame are all included within the security information field. In this case, a new subfield of 1 bit within the common control field may indicate the presence or absence of a security information field containing information for performing an integrity check within the corresponding trigger frame. The security information field may be defined as a separate field as shown in FIG. 14 (a), but may also be located as the last field of the feature-specific information field.

[0309] Additionally or alternatively, a key ID value for checking the integrity of a trigger frame may be set on a reserved bit within a common control field or a special user information field within the trigger frame. Through this, the receiving STA can confirm that values ​​for checking the integrity of the trigger frame are additionally included within the padding field of the trigger frame. In this case, the relevant PN and MIC values ​​may be included in a feature-specific information field or a security information field as illustrated in FIG. 14 (a). As another example, the value of the relevant PN may be included in a feature-specific information field as illustrated in FIG. 14 (a), and the MIC value may be included in a security information field.

[0310] Additionally or alternatively, the common control field may include information indicating the presence or absence of an intermediate FCS field before the padding field. A new 1-bit subfield within the common control field may indicate whether a field containing an intermediate FCS value is present before the padding value within the trigger frame.

[0311] For example, if the action supported by new information (e.g., information on one or more actions included in the new information) requires an intermediate FCS, an intermediate FCS value / field may be included within the trigger frame. In this case, the value of the new subfield may be set to a value (e.g., 0 or 1) indicating that the intermediate FCS field exists before the padding field within the trigger frame.

[0312] As another example, if the actions supported by new information (e.g., information on one or more actions included in the new information) do not require an intermediate FCS, the intermediate FCS value / field may not be included within the corresponding trigger frame. In this case, the value of the new subfield may be set to a value (e.g., 1 or 0) indicating that there is no intermediate FCS field before the padding field within the trigger frame.

[0313] For example, the STA(s) can confirm that they have reached the padding field within the trigger frame (e.g., started decoding the padding field) through the AID12 subfield set to 4095. If the new subfield of the common control field (e.g., a subfield indicating the presence of an intermediate FCS field before the padding value) indicates that an intermediate FCS field exists before the padding value (e.g., the new subfield value is 1 or 0), the STA(s) can perform an FCS check operation through the intermediate FCS.

[0314] For example, if an FCS check operation is successfully performed, the STA(s) may perform operations supporting DPS, integrity checks on trigger frames, DSO, operations related to DUO mode (e.g., IDC), NPCA and / or multi-AP coordination, etc., for a time corresponding to the padding value. At this time, the STA(s) may not perform FCS field-based FCS check operations after the time corresponding to the padding value.

[0315] Meanwhile, when a legacy STA (e.g., HE STA, EHT STA, etc.) and / or a UHR STA(s) that does not support DPS, integrity checks on trigger frames, DSO, operations related to DUO mode (e.g., IDC), NPCA and / or multi-AP coordination reaches the padding field of a trigger frame, it may perform the operations it is required to perform for a time corresponding to the padding value. Additionally, the legacy STA and the corresponding UHR STA(s) may perform an FCS check operation through the FCS field.

[0316] Example 7

[0317] Example 7 relates to a method for determining the length of padding within a trigger frame.

[0318] As described above, the length of the padding field in the trigger frame may be determined by the transmitting STA based on the larger of the time to prepare the UL MU data configuration in response to the trigger frame (hereinafter referred to as “MinTrigProcTime” of the trigger frame) or the padding delay time for Enhanced Multi-link Single Radio (EMLSR) / Enhanced Multi-link Multi-Radio (EMLMR) (if present).

[0319] The "MinTrigProcTime" for a trigger frame can be identified based on the value of the Trigger Frame MAC Padding Duration subfield in the HE MAC Capability Information field. The padding delay time for EMLSR / EMLMR can be identified based on the value of the EMLSR / EMLMR Padding Delay subfield in the EML Capability subfield of the Common Information field of the underlying multi-link element.

[0320] In the present disclosure, when the length of the padding field of a trigger frame containing an intermediate FCS (sub)field is determined, the padding delay time for the DPS can also be determined together (by comparing with the length of the padding field).

[0321] For example, an STA (e.g., a UHR STA) that supports DPS, integrity check for trigger frames, and / or DSO (etc.) may transmit and receive a join request frame and / or a separate new action frame to enable DPS. In this case, the join request frame and / or the new action frame may include a DPS padding delay value for a padding time of a padding field in a trigger frame desired by the STA. The DPS padding delay value may be set based on, but not limited to, the values ​​disclosed in Table 1 or Table 2.

[0322] DPS Padding Delay Subfield Value DPS Padding Delay 00 μs 132 μs 264 μs 3128 μs 4256 μs 5-7 Reserved

[0323] DPS Padding Delay Subfield Value DPS Padding Delay 00 μs 164 μs 2128 μs 3256 μs 41024 μs 5-7 Reserved

[0324] Additionally or alternatively, the DPS padding delay value announced from the STA to the AP may be based on N bits of a new (sub)field having the DPS padding delay value. For example, the DPS padding delay value may be a value calculated (e.g., "bit value x specific value") based on a specific value (e.g., unit, resolution) through the N bit value of the new (sub)field. Here, the specific value for obtaining (e.g., calculating) the DPS padding delay value may be one of 8, 16, 32, or 64. For example, if the new (sub)field has a length of 3 bits, the new sub(field) may have a value of one of 0 (e.g., "000") to 7 (e.g., "111"). The DPS padding delay value may be derived through the calculation of the value of the new sub(field) and the specific value.

[0325] As an example of the present disclosure, assume that a specific value is 64. In this case, if the new sub-field value is 0 (e.g., "000"), the DPS padding delay value may be 0 us. If the new sub-field value is 1 (e.g., "001"), the DPS padding delay value may be 64 us. If the new sub-field value is 2 (e.g., "010"), the DPS padding delay value may be 128 us. If the new sub-field value is 3 (e.g., "011"), the DPS padding delay value may be 192 us. If the new sub-field value is 4 (e.g., "100"), the DPS padding delay value may be 256 us. If the new sub-field value is 5 (e.g., "101"), the DPS padding delay value may be 320 us. If the new sub-field value is 6 (e.g., "110"), the DPS padding delay value may be 384 us. If the new sub-field value is 7 (e.g., "111"), the DPS padding delay value may be 448 us.

[0326] Additionally or alternatively, the DPS padding delay value announced from the STA to the AP may be based on N bits of a new (sub)field having the DPS padding delay value. For example, the DPS padding delay value may be obtained / calculated through an operation based on the N bit value of the new (sub)field and a specific value. In this case, the STA may also announce a specific value for calculating the DPS padding delay value to the AP. That is, a new (sub)field for the DPS padding delay and a new (sub)field including a specific value for calculating the DPS padding delay value may be defined. For example, 8, 16, 32, or 64 may be indicated through a new (sub)field value for a specific value (e.g., 0, 1, 2).

[0327] Additionally or alternatively, the DPS padding delay value announced from the STA to the AP may be based on a new (sub)field having the DPS padding delay value. For example, the DPS padding delay value may be obtained / calculated through an operation based on the N-bit value of the new (sub)field and a specific value. For example, as shown in Table 1, when the new (sub)field has a length of 3 bits, the DPS padding delay value may be derived if the bit value in a specific calculation formula has a value of 1 (e.g., "001") or greater.

[0328] Here, if the value of the above bit is 0, the DPS padding delay value can be considered as 0 us. For example, a specific calculation formula 2 (n+4) Assume the case where the N-bit value of the new (sub)field is 1 (e.g., "001"), the DPS padding delay value is 32 (2 5 ) can be us. If the N-bit value of the new (sub)field is 2 (e.g., "010"), the DPS padding delay value is 64 (2 6 ) can be us. If the N-bit value of the new (sub)field is 2 (e.g., "010"), the DPS padding delay value is 64 (2 6 ) can be us. If the N-bit value of the new (sub)field is 3 (e.g., "011"), the DPS padding delay value is 128 (2 7 ) can be us. If the N-bit value of the new (sub)field is 4 (e.g., "100"), the DPS padding delay value is 256 (2 8 ) can be us. If the N-bit value of the new (sub)field is 5 (e.g., "101"), the DPS padding delay value is 512 (2 9 ) can be us. If the N-bit value of the new (sub)field is 6 (e.g., "110"), the DPS padding delay value is 1024 (2 10 ) can be us. If the N-bit value of the new (sub)field is 7 (e.g., "111"), the DPS padding delay value is 2048 (211 ) could be us.

[0329] Additionally or alternatively, the DPS padding delay value announced from the STA to the AP may be based on a new (sub)field having a DPS padding delay value. Based on the value of each bit of the new (sub)field (e.g., m = 1 or 0) (m X 2 0 ) + (m X 2 1 ) + (m X 2 2 ) + (m X 2 3 ) + ... (m X 2 (N-1) The value of the DPS padding delay subfield can be derived by performing the operation. The derived value may be the DPS padding delay subfield value transmitted from a non-AP STA to the AP, and each value may have a microsecond unit. The AP may identify whether the corresponding DPS padding delay subfield value is within a specific range and then set a DPS_PADDING_DELAY value to calculate the padding length within the trigger frame.

[0330] Here, the method for determining whether the value of the DPS padding delay subfield falls within a specific range may be carried out according to the method described below, but is not limited thereto.

[0331] For example, AP can set the applicable value to "DPS_PADDING_DELAY" by mapping the value of the derived DPS padding delay subfield to Table 3.

[0332] DPS Padding Delay Subfield Value (us)DPS_PADDING_DELAY001 ~ 32133 ~ 64265 ~ 1283129 ~ 2564Reserved5-7

[0333] For example, if the value of the DPS padding delay subfield is between 1 and 32, the value of DPS_PADDING_DELAY may be set to 1. If the value of the DPS padding delay subfield is between 33 and 64, the value of DPS_PADDING_DELAY may be set to 2. If the value of the DPS padding delay subfield is between 65 and 128, the value of DPS_PADDING_DELAY may be set to 3. If the value of the DPS padding delay subfield is between 129 and 256, the value of DPS_PADDING_DELAY may be set to 4. Additionally or alternatively, AP may calculate the final DPS padding delay subfield value by performing a specific operation (e.g., multiplying by 2) on the derived DPS padding delay subfield value. The AP can set the DPS_PADDING_DELAY value to an applicable value by mapping the produced value to Table 4. For example, if the size of the new (sub)field is 8 bits, the DPS padding delay subfield value can be defined as in Table 4, but is not limited thereto.

[0334] DPS padding delay subfield value (us) DPS_PADDING_DELAY 00 1 ~ 64165 ~ 1282129 ~ 2563257 ~ 5124 Reserved 5-7

[0335] For example, if the DPS padding delay subfield value has a value from 1 to 64, the value of DPS_PADDING_DELAY may be set to 1. If the DPS padding delay subfield value has a value from 65 to 128, the value of DPS_PADDING_DELAY may be set to 2. If the DPS padding delay subfield value has a value from 129 to 256, the value of DPS_PADDING_DELAY may be set to 3. If the DPS padding delay subfield value has a value from 257 to 512, the value of DPS_PADDING_DELAY may be set to 4. Example 7-1

[0336] Example 7-1 relates to a method for determining the length of a padding field when an intermediate FCS value / field is included within the padding field of a trigger frame.

[0337] In one embodiment of the present disclosure, a transmitting STA may calculate the padding time required for an STA (e.g., a receiving STA) based on the larger of the “MinTrigProcTime” of a trigger frame, the padding (or transition) delay of EMLSR / EMLMR, and / or the DPS padding delay value. The transmitting STA may then determine the length of a padding field that is greater than or equal to the calculated result value (e.g., padding time).

[0338] For example, if the padding delay value of the DPS is defined by the values ​​exemplified in Table 1 or Table 2 or by the method according to the present disclosure, and the padding field value within the trigger frame is derived, "L PAD,MAC = N DBPS m PAD The formula can be used.

[0339] For example, N in the above equation DBPS can be set to a value calculated based on the value defined as a modulation-dependent parameter. If the padding delay value of DPS based on Table 1, Table 2, Table 3 or Table 4 is 0, m PAD can be set to 0.

[0340] For example, if the padding delay value of the DPS based on Table 1 or Table 3 is greater than 0, m PAD It can be set based on 2"DPS padding delay + 2". For example, if Table 1 is applied, the padding delay value of DPS can be one of the DPS padding delay subfield values ​​listed in the left column of Table 1. If Table 3 is applied, the padding delay value of DPS can be one of the DPS_PADDING_DELAY values ​​listed in the right column of Table 3.

[0341] As another example, if the padding delay value of DPS based on Table 2 or Table 4 is greater than 0, m PAD It can be set based on 2"DPS padding delay + 3". For example, if Table 2 is applied, the padding delay value of DPS can be one of the DPS padding delay subfield values ​​listed in the left column of Table 2. If Table 4 is applied, the padding delay value of DPS can be one of the DPS_PADDING_DELAY values ​​listed in the right column of Table 4.

[0342] Additionally or alternatively, the DPS padding delay value may be calculated based on a new (sub)field of N bits having a DPS padding delay value. When the DPS padding delay value is calculated by an operation (e.g., "bit value * specific value") on the value of the N bits of the new (sub)field and a specific value (e.g., unit, resolution, etc.), m PAD can be predefined as to what value it will be set to. The transmitting STA can set the length of the padding field based on the values ​​described above. For example, if a specific value is 64 and the new (sub)field value for DPS padding delay is 4 (e.g., "100"), the resulting value can be 256us. In this case, m PAD can be defined to be set to 64.

[0343] As described above, the length of the padding field determined may mean the length corresponding to padding B in FIG. 14 (b). Based on the embodiments described above (e.g., Example 6), the length of the padding field within the trigger frame determined may be extended by the length of the field(s) containing new information and / or the intermediate FCS. That is, the total length of the padding field within the trigger frame may mean the length corresponding to padding A in FIG. 14 (b).

[0344] Additionally or alternatively, as illustrated in FIG. 14(b), the padding field may be indicated to be reached within the trigger frame by setting 1 for the first two octets of the padding field. As another example, the field(s) containing new information and the value of the intermediate FCS may be located after the AID12 subfield (e.g., 12 bits) of the padding field set to 4095.

[0345] The receiving STA can calculate the length of the padding field and padding times from the total MPDU length of the trigger frame based on the value of the MPDU delimiter. Depending on the supported technology / operation of the receiving STA, operations according to the cases described below may be performed on the padding field within the trigger frame.

[0346] Case 1: Legacy STAs and / or STAs that do not support (e.g., DPS, integrity checks for trigger frames, and / or DSO, DUO mode (e.g., IDC), NPCA, and / or multi-AP coordination) (UHR STAs) can decode an AID12 subfield set to 4095 (e.g., an AID12 subfield indicating a padding field). Then, the STA(s) can perform a specific operation during the padding time of padding A in FIG. 14(b). Here, the specific operation may include, but is not limited to, an operation for EMLSR / EMLMR (e.g., a link switching operation) and / or an operation to generate UL MU data corresponding to a trigger frame. The link switching operation may include an operation to consolidate resources into a single link while various operations are being performed on two links.

[0347] Case 2: An STA (e.g., UHR STA) that supports DPS, integrity check for trigger frames, and / or DSO, DUO mode (e.g., IDC), NPCA, and / or multi-AP coordination may recognize the presence of field(s) containing new information and an intermediate FCS in the trigger frame. Accordingly, the STA(s) may decode field(s) containing new information and an intermediate FCS value located after the AID12 subfield indicating a padding field (e.g., the AID subfield set to 4095).

[0348] For example, in the case of a trigger frame to which an integrity check (for a trigger frame) is applied, the STA may perform an integrity check based on information for integrity check (e.g., key ID, PN, MIC) included in the trigger frame. If the integrity check operation is successfully performed, the receiving STA may accept the information obtained from the trigger frame. If the integrity check operation fails, the receiving STA may discard the information obtained from the trigger frame.

[0349] Additionally or alternatively, if an intermediate FCS value / field exists on the trigger frame, the STA(s) may perform an FCS check operation based on the intermediate FCS value / field. If the FCS check operation is successful, the STA(s) may perform the above-described operation(s) (e.g., DPS, integrity check for the trigger frame, and / or DSO, DUO mode (e.g., IDC), NPCA, and / or multi-AP coordination) during the padding time of padding B illustrated in (b) of FIG. 14.

[0350] For example, operations related to DPS may include an operation to switch from a low capability bandwidth (e.g., 20 MHz) to a high capability bandwidth (e.g., 80 MHz) and / or an operation to check CCA based on SIFS on the corresponding TXOP bandwidth according to said switching operation. Additionally, when transmitting UL MU data corresponding to a trigger frame, the STA(s) may prepare the UL MU data during that time.

[0351] If there is no intermediate FCS value / field on the trigger frame, the receiving STA may prepare UL MU data to be transmitted to the transmitting STA during the padding time of padding B as shown in (b) of Fig. 14. Then, the receiving STA may perform an FCS check operation based on the FCS field located after the padding field of the trigger frame.

[0352] Case 3: If the (UHR) STA in Case 2 supports EMLSR / EMLMR, the STA(s) can perform an operation that supports EMLSR / EMLMR (e.g., link switching) during the padding time of padding B in FIG. 14 (b). Additionally, when transmitting UL MU data corresponding to a trigger frame, the STA(s) can prepare UL MU data during that time.

[0353] Additionally or alternatively, STA(s) that performed FCS check based on intermediate FCS, such as Case 2 and Case 3, may not perform FCS check operation based on FCS field after padding time.

[0354] Example 8

[0355] Example 8 relates to operations performed by each of a transmitting STA and a receiving STA. Example 8-1 relates to operations of a transmitting STA (e.g., an AP, etc.) that transmits a trigger frame, and Example 8-2 relates to operations of a receiving STA (e.g., a non-AP STA) that receives a trigger frame.

[0356] Example 8-1

[0357] The transmitting STA can determine whether the receiving STA supports / performs operations related to DPS, integrity checks for trigger frames, DSO, operations related to DUO mode (e.g., IDC), NPCA and / or multi-AP coordination during the padding time. If the receiving STA supports DPS, integrity checks for trigger frames, operations related to DSO, DUO mode (e.g., IDC), NPCA and / or multi-AP coordination, the transmitting STA may include field(s) containing new information and the value of an intermediate FCS within the trigger frame.

[0358] For example, if the padding field of a trigger frame contains field(s) containing new information and / or an intermediate FCS field in which the value of the intermediate FCS is set, the transmitting STA may construct a trigger frame based on the embodiments described above (e.g., Embodiment 6) and transmit the constructed trigger frame to the receiving STA. In this case, the field(s) containing new information and / or an intermediate FCS field may be included after the AID12 subfield indicating the padding field within the trigger frame.

[0359] Example 6-2

[0360] As an example of the present disclosure, a legacy STA (e.g., a STA that does not support DPS, integrity checks for trigger frames, DSO, operations related to DUO mode (e.g., IDC), NPCA and / or multi-AP coordination) can decode a trigger frame transmitted by a transmitting STA. In this case, the legacy STA may recognize that the information in the user information field of the corresponding trigger frame (e.g., a trigger frame based on Example 6, etc.) does not correspond to it and may ignore it.

[0361] As another example, DPS, integrity checks for trigger frames, operations related to DSO and DUO modes (e.g., IDC), and STAs that support NPCA and / or multi-AP coordination (e.g., UHR STA) can determine whether additional information is included in the padding field of a trigger frame through a subfield indicating whether specific information exists within the padding subfield.

[0362] For example, assume that a STA that supports DPS, integrity checks for trigger frames, DSO, operations related to DUO mode (e.g., IDC), NPCA, and / or multi-AP coordination (e.g., UHR STA) reaches an AID12 subfield value indicating that it is a padding field within a trigger frame. The STA may recognize that there is a field(s) containing new information located after the AID12 subfield or 4 bits (e.g., additional 4 bits adjacent to the AID12 subfield) and / or an intermediate FCS value, and may perform an FCS check operation based on the intermediate FCS.

[0363] For example, if the result of an FCS check based on the intermediate FCS value of the UHR STA is successful, the UHR STA may perform operations supported by the UHR STA during the padding time, such as DPS, integrity checks for trigger frames, DSO, operations related to DUO mode (e.g., IDC), NPCA, and / or multi-AP coordination. After the padding time of the padding field, the receiving STA may not perform additional FCS check operations during the time corresponding to the FCS field (e.g., an FCS field placed following the padding field). Additionally, if UL MU data needs to be transmitted in response to a trigger frame, the STA may perform UL MU data generation operations during the padding time.

[0364] For example, if the result of an FCS check based on an intermediate FCS value of a receiving STA (e.g., UHR STA) is a failure (e.g., FCS check failure and / or FCS value is incorrect), the receiving STA may perform EIFS (Extended Interframe Space) related operations on the FCS field after the padding time of the padding field.

[0365] In one example of the present disclosure, when the value of an AID12 subfield indicating the start of a padding field is obtained, a receiving STA (e.g., a legacy STA or DPS, an integrity check for a trigger frame, an operation related to DSO, DUO mode (e.g., IDC), NPCA and / or a UHR STA that does not support multi-AP coordination) may recognize that the padding field has started and perform a specific operation (e.g., generating UL MU data, etc.) during the padding time. Additionally, the receiving STA may perform an FCS check operation using the FCS field following the padding field. For example, if the result of the FCS check based on the FCS field is successful, the legacy STA may transmit UL MU data for the trigger frame to the transmitting STA. In another example, if the result of the FCS check fails, the receiving STA may perform an EIFS-related operation.

[0366] At least one of the above-described embodiments of the present disclosure (e.g., Example 1, Example 2, Example 3, Example 3-1, Example 4, Example 4-1, Example 5, Example 6, Example 6-1, Example 6-2, Example 7, Example 7-1, Example 8, Example 8-1 and / or Example 8-2) may be applied, and combinations of each embodiment may be applied.

[0367] 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.

[0368] 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.

[0369] 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.

[0370] The method proposed in this disclosure has been 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

A step of receiving a trigger frame including a padding field from a second STA by a first station (STA); The step of decoding the above trigger frame by the first STA, and The above padding field includes a common control subfield and an intermediate frame check sequence (FCS) subfield, and A method in which the common control subfield comprises a first subfield related to whether at least one of a per-feature information subfield or a security information subfield is included within the padding field. In paragraph 1, The above trigger frame includes a common information field, and A method in which the common information field or the common control subfield comprises a second subfield related to whether the intermediate FCS subfield exists on the padding field. In paragraph 1, The message integrity code (MIC) value is included in the security information subfield above, and A method in which each of the packet number (PN) and key identifier (ID) is included in the security information subfield or the feature-specific information subfield. In paragraph 3, The above key ID is used to check the integrity of the above trigger frame, and A method in which the key ID is set on at least one bit of the common control subfield or the special user information field of the trigger frame. In paragraph 1, The above padding field includes an association identifier (AID)12 subfield and an additional 4 bits adjacent to the AID12 subfield, and A method in which the above AID12 subfield and the above additional 4 bits are set to 1. In paragraph 1, A method in which the above common control subfield and the above feature-specific information subfield are located following the AID12 subfield and the additional 4 bits within the trigger frame. In paragraph 1, A method wherein the above feature-specific information subfield includes information related to at least one of dynamic power save (DPS), integrity check for control frames, dynamic subband operation (DSO), operation for dynamic unavailability operation (DUO) mode, non-primary channel access, or multi-access point (AP) coordination. In paragraph 7, A method in which the common control subfield comprises a third subfield related to whether each of the following is included on the feature-specific information subfield: the DPS, the integrity check for the control frame, the DSO, the operation for the DUO mode, the non-primary channel access, or the multi-AP coordination. In paragraph 7, The above intermediate FCS subfield is placed before the fourth subfield in which the padding value is set within the padding field, A method wherein an FCS check operation is performed by the first STA based on the intermediate FCS subfield. In paragraph 9, A method wherein, based on the success of the FCS check operation, at least one of the DPS, the integrity check for the control frame, the DSO, the DUO mode, the non-primary channel access, or the multi-AP coordination is performed by the first STA through the feature-specific information subfield within a time period corresponding to the padding value. In paragraph 1, A method in which the length of the padding field is determined based on the value of the DPS padding delay field, the time value for processing the trigger frame, and the largest value among the padding delay values ​​associated with improved multi-link single radio (EMLSR) or improved multi-link multi-radio (EMLMR). In paragraph 1, The length of the above intermediate FCS field is 32 bits. In the first station (STA), the first STA: One or more transceivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Receiving a trigger frame including a padding field from a second STA through the one or more transceivers; is set to decode the above trigger frame, The above padding field includes a common control subfield and an intermediate frame check sequence (FCS) subfield, and A first STA, wherein the common control subfield includes a first subfield related to whether at least one of a per feature information subfield or a security information subfield is included within the padding field. A step of generating a trigger frame including a padding field by a second station (STA); comprising a step of transmitting the trigger frame to the first STA by the second STA, The above padding field includes a common control subfield and an intermediate frame check sequence (FCS) subfield, and A method in which the common control subfield comprises a first subfield related to whether at least one of a per-feature information subfield or a security information subfield is included within the padding field. In the second station (STA), the second STA: 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: Create a trigger frame containing padding fields; The trigger frame is set to be transmitted to the first STA via the one or more transceivers, The above padding field includes a common control subfield and an intermediate frame check sequence (FCS) subfield, and A second STA, wherein the common control subfield includes a first subfield related to whether at least one of a per feature information subfield or a security information subfield is included within the padding field. In a processing device, 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 12. 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 to perform a method according to any one of claims 1 to 12.

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