Method and device for performing integrated critical update procedure in wireless LAN system

Abstract

Disclosed are a method and device for performing communication in a wireless LAN system. The method according to an embodiment of the present disclosure may comprise a step in which a first access point (AP) generates a first frame including an ultra-high reliability (UHR) parameter update element; and the first AP transmits the first frame, wherein the first frame includes an enhanced critical updates flag field set to 1 and an enhanced all updates-included field related to the UHR parameter update element, and the UHR parameter update element may include at least one field related to enable, disable, or update for at least one parameter for dynamic power save (DPS).

Description

Method and device for performing an integrated critical update procedure in a wireless LAN system

[0001] The present disclosure relates to a method and apparatus for performing a unified critical update procedure in a Wireless Local Area Network (WLAN) system.

[0002] New technologies have been introduced for wireless LANs (WLANs) to improve transmission rates, increase bandwidth, enhance reliability, reduce errors, and reduce latency. Among wireless LAN technologies, the IEEE (Institute of Electrical and Electronics Engineers) 802.11 series of standards can be referred to as Wi-Fi. For example, technologies recently introduced to wireless LANs 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 an improved wireless communication environment, advanced technologies for Extremely High Throughput (EHT) are being discussed. For example, technologies for Multiple Input Multiple Output (MIMO) supporting increased bandwidth, efficient utilization of multiple bands, and increased spatial streams, as well as technologies for multiple access points (AP) coordination, are being researched. In particular, various technologies are being studied to support traffic with low latency or real-time characteristics. Furthermore, new technologies to support ultra-high reliability (UHR), including improvements or extensions of EHT technology, are being discussed.

[0004] The technical problem of the present disclosure is to provide a method and apparatus for performing an integrated critical update procedure in a wireless LAN system.

[0005] The technical problem of the present disclosure is to provide a method and apparatus for updating dynamic power save (DPS) parameter(s) through a critical update procedure.

[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: generating a first frame by a first access point (AP) that includes an ultra-high reliability (UHR) parameter update element; and transmitting the first frame by the first AP, wherein the first frame includes an enhanced critical updates flag field set to 1 and an enhanced all updates included field associated with the UHR parameter update element, and the UHR parameter update element may include at least one field associated with enabling, disabling, or updating at least one parameter for dynamic power save (DPS).

[0008] A method according to another embodiment of the present disclosure comprises: receiving a first frame containing an ultra-high reliability (UHR) parameter update element from a first access point (AP) by a first station (STA); and decoding the first beacon frame by the first STA, wherein the first frame includes an enhanced critical updates flag field set to 1 and an enhanced all updates included field associated with the UHR parameter update element, and the UHR parameter update element may include at least one field associated with enabling, disabling, or updating at least one parameter for dynamic power save (DPS).

[0009] By various embodiments of the present disclosure, a method for performing an integrated critical update procedure in a wireless LAN system may be provided.

[0010] By various embodiments of the present disclosure, the updated parameter(s) can be identified more efficiently through an integrated critical update procedure.

[0011] By various embodiments of the present disclosure, a method and apparatus for updating DPS parameter(s) through a critical update procedure may be provided.

[0012] By various embodiments of the present disclosure, signaling overhead can be reduced by transmitting only updated information through beacon frames.

[0013] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below.

[0014] The accompanying drawings, which are included as part of the detailed description to aid in understanding the present disclosure, provide embodiments of the present disclosure and explain the technical features of the present disclosure together with the detailed description.

[0015] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0016] FIG. 2 is a drawing showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0017] FIG. 3 is a diagram illustrating a link setup process to which the present disclosure can be applied.

[0018] FIG. 4 is a drawing illustrating a backoff process to which the present disclosure may be applied.

[0019] FIG. 5 is a diagram illustrating a CSMA / CA-based frame transmission operation to which the present disclosure may be applied.

[0020] FIG. 6 is a drawing for illustrating an example of a frame structure used in a wireless LAN system to which the present disclosure may be applied.

[0021] FIG. 7 is a drawing illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure may be applied.

[0022] FIG. 8 illustrates, exemplarily, the structure of an ML element to which the present disclosure can be applied.

[0023] Figure 9 is a diagram illustrating the critical update procedure.

[0024] Figure 10 is a diagram illustrating the format of the MLD parameter subfield.

[0025] FIG. 11 is a flowchart illustrating a method performed by a first AP according to one embodiment of the present disclosure.

[0026] FIG. 12 is a flowchart illustrating a method performed by a first STA according to one embodiment of the present disclosure.

[0027] FIGS. 13 and FIGS. 14 are drawings for illustrating a basic multi-link element according to one embodiment of the present disclosure.

[0028] FIG. 15 is a drawing for explaining the configuration of a TBTT information field according to one embodiment of the present disclosure.

[0029] FIG. 16 is a drawing for illustrating a basic multi-link element according to one embodiment of the present disclosure.

[0030] FIG. 17 is a drawing for explaining a parameter update instruction method according to one embodiment of the present disclosure.

[0031] FIG. 18 is a drawing for illustrating a basic multi-link element according to one embodiment of the present disclosure.

[0032] FIG. 19 illustrates a UHR critical update procedure according to one embodiment of the present disclosure when AP 1 and AP 2 belong to the same AP MLD.

[0033] FIG. 20 is a diagram illustrating a PPDU transmission and reception procedure between a transmitting STA and a receiving STA according to one embodiment of the present disclosure.

[0034] Hereinafter, preferred embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed below, together with the accompanying drawings, is intended to describe exemplary embodiments of the present disclosure and is not intended to represent the only embodiment in which the present disclosure may be practiced. The following detailed description includes specific details to provide a complete understanding of the present disclosure. However, those skilled in the art will know that the present disclosure may be practiced without such specific details.

[0035] In some cases, to avoid obscuring the concept of the present disclosure, known structures and devices may be omitted or illustrated in the form of a block diagram focusing on the core functions of each structure and device.

[0036] 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.

[0037] In the present disclosure, terms such as "first," "second," etc. are used solely for the purpose of distinguishing one component from another and are not used to limit the components, nor do they limit the order or importance of the components unless specifically stated otherwise. Accordingly, within the scope of the present disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and likewise, a second component in one embodiment may be referred to as a first component in another embodiment.

[0038] 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.

[0039] The embodiments of the present disclosure may be applied to various wireless communication systems. For example, the embodiments of the present disclosure may be applied to wireless LAN systems. For example, the embodiments of the present disclosure may be applied to wireless LANs based on IEEE 802.11a / g / n / ac / ax / be standards. Furthermore, the embodiments of the present disclosure may be applied to wireless LANs based on newly proposed IEEE 802.11bn (or UHR) standards. Additionally, the embodiments of the present disclosure may be applied to wireless LANs based on next-generation standards following IEEE 802.11bn. Furthermore, the embodiments of the present disclosure may be applied to cellular wireless communication systems. For example, they may be applied to cellular wireless communication systems based on LTE (Long Term Evolution) series technologies and 5G NR (New Radio) series technologies of 3GPP (3rd Generation Partnership Project) standards.

[0040] The following describes the technical features to which the examples of the present disclosure may be applied.

[0041] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0042] The first device (100) and the second device (200) exemplified in FIG. 1 may be replaced with various terms such as terminal, wireless device, WTRU (Wireless Transmit Receive Unit), UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), MSS (Mobile Subscriber Unit), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), or simply user. Additionally, the first device (100) and the second device (200) may be replaced with various terms such as access point (AP), base station (BS), fixed station, Node B, base transceiver system (BTS), network, artificial intelligence (AI) system, road side unit (RSU), repeater, router, relay, gateway, etc.

[0043] The device (100, 200) exemplified in FIG. 1 may be referred to as a station (STA). For example, the device (100, 200) exemplified in FIG. 1 may be referred to by various terms such as a transmitting device, a receiving device, a transmitting STA, or a receiving STA. For example, the STA (110, 200) may perform the role of an access point (AP) or a non-AP. That is, in the present disclosure, the STA (110, 200) may perform the functions of an AP and / or a non-AP. If the STA (110, 200) performs the AP function, it may simply be referred to as an AP, and if the STA (110, 200) performs the non-AP function, it may simply be referred to as a STA. Additionally, in the present disclosure, the AP may also be indicated as an AP STA.

[0044] 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.

[0045] In addition, the first device (100) and the second device (200) may additionally support various communication standards other than wireless LAN technology (e.g., 3GPP LTE series, 5G NR series standards, etc.). In addition, the device of the present disclosure may be implemented as various devices such as mobile phones, vehicles, personal computers, AR (Augmented Reality) equipment, VR (Virtual Reality) equipment, etc. Furthermore, the STA of the present specification may support various communication services such as voice calls, video calls, data communication, autonomous driving, MTC (Machine-Type Communication), M2M (Machine-to-Machine), D2D (Device-to-Device), and IoT (Internet-of-Things).

[0046] 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). Memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, memory (104) may store software code including instructions for performing some or all of the processes controlled by the processor (102) or for performing the descriptions, functions, procedures, proposals, methods, and / or sequences of operation disclosed in this disclosure. Here, the processor (102) and memory (104) may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., IEEE 802.11 series). A transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals through one or more antennas (108). The transceiver (106) may include a transmitter and / or receiver. The transceiver (106) may be combined with an RF (Radio Frequency) unit. In the present disclosure, the device may refer to a communication modem / circuit / chip.

[0047] The second device (200) includes one or more processors (202) and one or more memories (204), and may additionally include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memory (204) and / or transceivers (206) 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 (202) may process information within the memory (204) to generate a third information / signal and then transmit a wireless signal containing the third information / signal through the transceiver (206). Additionally, the processor (202) may receive a wireless signal containing a fourth information / signal through the transceiver (206) and then store information obtained from the signal processing of the fourth information / signal in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may store software code containing instructions for performing some or all of the processes controlled by the processor (202) or for performing the descriptions, functions, procedures, proposals, methods, and / or sequences of operation disclosed in this disclosure. Here, the processor (202) and the memory (204) may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., IEEE 802.11 series). The transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals through one or more antennas (208). The transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be used in combination with an RF unit. In the present disclosure, the device may refer to a communication modem / circuit / chip.

[0048] Hereinafter, 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 Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this 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 flowcharts of operation disclosed in this disclosure. One or more processors (102, 202) may generate a signal (e.g., a baseband signal) including a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this disclosure and provide it to one or more transceivers (106, 206). One or more processors (102, 202) may receive a signal (e.g., a baseband signal) from one or more transceivers (106, 206) and may obtain a PDU, SDU, message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this disclosure.

[0049] One or more processors (102, 202) may be referred to as a controller, microcontroller, microprocessor, or 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 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. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this disclosure may be included in 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 sequences disclosed in this disclosure may be implemented using firmware or software in the form of code, instructions, and / or sets of instructions.

[0050] One or more memories (104, 204) may be connected to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. One or more memories (104, 204) may be composed of ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer read storage media, and / or combinations thereof. One or more memories (104, 204) may be located inside and / or outside of one or more processors (102, 202). Additionally, one or more memories (104, 204) may be connected to one or more processors (102, 202) through various technologies such as wired or wireless connections.

[0051] One or more transceivers (106, 206) may transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or operation flowcharts, etc., of the present disclosure to one or more other devices. One or more transceivers (106, 206) may receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts, etc., disclosed in the present disclosure from one or more other devices. For example, one or more transceivers (106, 206) may be connected to one or more processors (102, 202) and may transmit and receive wireless signals. For example, one or more processors (102, 202) may 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 connected 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, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this disclosure through one or more antennas (108, 208). In this disclosure, one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert the received wireless signal / channel, etc. from an RF band signal to a baseband signal in order to process the received user data, control information, wireless signal / channel, etc. using one or more processors (102, 202).One or more transceivers (106, 206) can convert user data, control information, wireless signals / channels, etc. processed using one or more processors (102, 202) from baseband signals to RF band signals. To this end, one or more transceivers (106, 206) may include (analog) oscillators and / or filters.

[0052] 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 transceiver (106, 206) of FIG. 1 may perform the operation of transmitting and receiving signals (e.g., packets or PPDU (Physical Layer Protocol Data Unit) according to IEEE 802.11a / b / g / n / ac / ax / be / bn, etc.). Additionally, the operation of generating transmission and reception signals or performing data processing or calculations in advance for transmission and reception signals by various STAs in the present disclosure may be performed by the processor (102, 202) of FIG. 1. For example, an example of an operation to generate a transmission and reception signal or to perform data processing or operations in advance for a transmission and reception signal may include: 1) an operation to determine / acquire / configure / operate / decode / encode bit information of fields (SIG (signal), STF (short training field), LTF (long training field), Data, etc.) included in the PPDU; 2) an operation to determine / configure / acquire time resources or frequency resources (e.g., subcarrier resources) used for fields (SIG, STF, LTF, Data, etc.) included in the PPDU; 3) an operation to determine / configure / acquire specific sequences (e.g., pilot sequence, STF / LTF sequence, extra sequence applied to SIG) used for fields (SIG, STF, LTF, Data, etc.) included in the PPDU; 4) power control operations and / or power saving operations applied to the STA; and 5) operations related to determining / acquiring / configuring / operating / decoding / encoding of an ACK signal. 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.

[0053] In the following, the 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 the AP STA, and the receiver may be part of the non-AP STA. The 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 the non-AP STA, and the receiver may be part of the AP STA.

[0054] FIG. 2 is a drawing showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0055] 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.

[0056] 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 since connections to distributed systems (DS) are not allowed, they form a self-contained network.

[0057] The membership of an STA in a BSS can be dynamically changed by the STA being turned on or off, or by the STA entering or leaving the BSS area. To become a member of a BSS, an STA can join the BSS using a synchronization process. To access all services of the BSS infrastructure, an STA must be associated with the BSS. This association can be configured dynamically and may include the use of a Distribution System Service (DSS).

[0058] In a wireless LAN, the direct STA-to-STA distance may be limited by PHY performance. In some cases, this distance limit may be sufficient, but in others, communication between STAs over longer distances may be required. To support extended coverage, a distributed system (DS) may be configured.

[0059] DS refers to a structure in which BSSs are interconnected. Specifically, as shown in FIG. 2, a BSS may exist as a component in an extended form of a network composed of multiple BSSs. DS is a logical concept and can be specified by the characteristics of the Distributed System Medium (DSM). In this regard, the Wireless Medium (WM) and the DSM can be logically distinguished. Each logical medium is used for a different purpose and is utilized by different components. These media are not limited to being identical or different. The flexibility of the wireless LAN structure (DS structure or other network structure) can be explained by the fact that multiple media are logically distinct in this way. That is, the wireless LAN structure can be implemented in various ways, and the corresponding wireless LAN structure can be specified independently by the physical characteristics of each implementation.

[0060] DS can support mobile devices by providing seamless integration of multiple BSSs and providing logical services necessary for handling addresses to destinations. Additionally, DS may include a component called a portal that acts as a bridge for connecting the wireless LAN with another network (e.g., IEEE 802.X).

[0061] An AP refers to an entity that enables access to a DS via a WM for combined non-AP STAs and also possesses the functionality of an STA. Data movement between a BSS and a DS can be performed through the AP. For example, STA2 and STA3 shown in FIG. 2 possess the functionality of an STA and provide the ability for combined non-AP STAs (STA1 and STA4) to access a DS. Furthermore, since all APs fundamentally correspond to STAs, all APs are addressable entities. The address used by the AP for communication on the WM and the address used by the AP for communication on the DSM do not necessarily have to be the same. A BSS composed of an AP and one or more STAs can be referred to as an infrastructure BSS.

[0062] Data transmitted from one of the STA(s) coupled to the AP to the STA address of the AP can always be received at an uncontrolled port and processed by an IEEE 802.1X port access entity. Additionally, if the controlled port is authenticated, the transmitted data (or frame) can be forwarded to the DS.

[0063] In addition to the structure of the aforementioned DS, an Extended Service Set (ESS) may be configured to provide wider coverage.

[0064] 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.

[0065] In wireless LAN systems, no assumptions are made regarding the relative physical locations of BSSs, and all of the following forms are possible. BSSs may partially overlap, which is a form commonly used to provide continuous coverage. Additionally, BSSs may not be physically connected, and logically, there is no limit to the distance between BSSs. Furthermore, BSSs may be located in the same physical location, which can be used to provide redundancy. Also, one (or more) IBSS or ESS networks may physically exist in the same space as one (or more) ESS networks. This may apply to ESS network forms such as when an ad-hoc network operates at a location where an ESS network exists, when wireless networks that physically overlap are configured by different organizations, or when two or more different access and security policies are required at the same location.

[0066] FIG. 3 is a diagram illustrating a link setup process to which the present disclosure can be applied.

[0067] 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.

[0068] 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.

[0069] 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 in the same way (i.e., transmit and receive probe request / response on channel 2).

[0070] Although not illustrated in FIG. 3, the scanning operation may be performed using a passive scanning method. In passive scanning, the STA performing the scanning waits for a beacon frame while switching between channels. A beacon frame is one of the management frames defined in IEEE 802.11, which is periodically transmitted to announce the presence of a wireless network and to allow the scanning STA to find the wireless network and join it. In a BSS, the AP performs the role of periodically transmitting beacon frames, and in an IBSS, the STAs within the IBSS take turns transmitting beacon frames. When the scanning STA receives a beacon frame, it stores the information about the BSS included in the beacon frame and records the beacon frame information in each channel while moving to another channel. The STA that receives the beacon frame stores the BSS-related information included in the received beacon frame and moves to the next channel, and can perform scanning in the next channel in the same way. When comparing active scanning and passive scanning, active scanning has the advantage of lower delay and power consumption than passive scanning.

[0071] 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 in step S340 described later.

[0072] The authentication process involves the STA sending an authentication request frame to the AP, and the AP sending an authentication response frame to the STA in response. The authentication frame used in the authentication request / response corresponds to a management frame.

[0073] The authentication frame may include information regarding the authentication algorithm number, authentication transaction sequence number, status code, challenge text, Robust Security Network (RSN), Finite Cyclic Group, etc. These are some examples of information that may be included in the authentication request / response frame, and they may be replaced with other information or additional information may be included.

[0074] The STA can send an authentication request frame to the AP. Based on the information contained in the received authentication request frame, the AP can determine whether to allow authentication for the STA. The AP can provide the result of the authentication process to the STA through an authentication response frame.

[0075] After the STA is successfully authenticated, the association process can be performed in step S330. The association process includes the STA transmitting an association request frame to the AP, and in response, the AP transmitting an association response frame to the STA.

[0076] 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 some examples of information that may be included in a combined request / response frame, and may be replaced with other information or additional information may be included.

[0077] 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.

[0078] 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.

[0079] FIG. 4 is a drawing illustrating a backoff process to which the present disclosure may be applied.

[0080] 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 Clear Channel Assessment (CCA) to sense the wireless channel or medium for a predetermined time interval (e.g., DIFS (DCF Inter-Frame Space)) before starting transmission. If the sensing result determines that the medium is in an idle status, it starts transmitting a frame through that 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 wait by setting a delay period for medium access (e.g., a random backoff period) before attempting to transmit a frame. 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.

[0081] In addition, the IEEE 802.11 MAC protocol provides a Hybrid Coordination Function (HCF). The HCF is based on the aforementioned Point Coordination Function (PCF). The PCF is a polling-based synchronous access method that periodically polls to ensure all receiving APs and / or STAs can receive data frames. Furthermore, the HCF includes Enhanced Distributed Channel Access (EDCA) and Controlled Channel Access (HCCA). EDCA is a contention-based access method for a provider to offer data frames to multiple users, while HCCA uses a non-contention-based channel access method utilizing a polling mechanism. Additionally, the HCF includes a media access mechanism to improve the Quality of Service (QoS) of the wireless LAN and can transmit QoS data during both the Contention Period (CP) and the Contention-Free Period (CFP).

[0082] 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, ...).

[0083] When the random backoff process begins, the STA continues to monitor the media while counting down the backoff slots according to the determined backoff count value. When the media is monitored as occupied, it stops the countdown and waits, and when the media becomes idle, it resumes the remaining countdown.

[0084] In the example of Fig. 4, when a packet to be transmitted arrives at the MAC of STA3, STA3 confirms that the medium is idle for DIFS and can immediately transmit the frame. The remaining STAs monitor whether the medium is occupied or busy and wait. Meanwhile, data to be transmitted may also arise from each of STA1, STA2, and STA5, and each STA can perform a countdown of the backoff slot according to a random backoff count value selected by each after waiting for DIFS when the medium is monitored to be idle. Assume the case where STA2 selects the smallest backoff count value and STA1 selects the largest backoff count value. That is, this exemplifies a case where, at the point when STA2 finishes the backoff count and starts transmitting the frame, the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1. STA1 and STA5 pause the countdown briefly and wait while STA2 occupies the medium. When STA2's possession ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and then resume the paused backoff count. That is, they can start transmitting a frame after counting down the remaining backoff slots corresponding to the remaining backoff time. Since STA5's remaining backoff time was shorter than STA1's, STA5 starts transmitting the frame. While STA2 is occupying the medium, data to be transmitted may also be generated by STA4. From STA4's perspective, when the medium becomes idle, it waits for DIFS, performs a countdown based on a random backoff count value selected by itself, and can start transmitting a frame. The example in Figure 4 illustrates a case where STA5's remaining backoff time happens to match STA4's random backoff count value; in this case, a collision may occur between STA4 and STA5. If a collision occurs, neither STA4 nor STA5 receives an ACK, resulting in a failure to transmit data.In this case, STA4 and STA5 can double the CW value, select a random backoff count value, and perform a countdown. STA1 waits while the medium is occupied due to transmission by STA4 and STA5, and when the medium becomes idle, it waits for DIFS, and then can start transmitting frames after the remaining backoff time has passed.

[0085] 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.

[0086] A QoS (Quality of Service) STA can transmit a frame after backoff, which is performed after the passage of the arbitration IFS (AIFS) for the access category (AC) to which the frame belongs, i.e., AIFS[i] (where i is a value determined by the AC). Here, the frame for which AIFS[i] can be used can be a data frame or a management frame, and can also be a control frame rather than a response frame.

[0087] FIG. 5 is a diagram illustrating a CSMA / CA-based frame transmission operation to which the present disclosure may be applied.

[0088] As previously mentioned, the CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing, where the STA directly senses the medium. Virtual carrier sensing is intended to mitigate problems that may occur in medium access, such as the hidden node problem. For virtual carrier sensing, the STA's MAC can utilize the Network Allocation Vector (NAV). The NAV is a value that indicates to other STAs the time remaining until the medium becomes available, provided that the STA currently using or authorized to use the medium is using it. Therefore, the value set as the NAV corresponds to the period during which the medium is scheduled to be used by the STA transmitting the frame, and the 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 frame's MAC header.

[0089] In the example of FIG. 5, it is assumed that STA1 intends to transmit data to STA2, and STA3 is located in a position where it can overhear part or all of the frames transmitted and received between STA1 and STA2.

[0090] In order to reduce the possibility of collisions between multiple STAs in a CSMA / CA-based frame transmission operation, a mechanism utilizing RTS / CTS frames may be applied. In the example of FIG. 5, while STA1 is transmitting, the medium may be determined to be idle based on the carrier sensing result of STA3. That is, STA1 may be a hidden node to STA3. Alternatively, in the example of FIG. 5, while STA2 is transmitting, the medium may be determined to be idle based on the carrier sensing result of STA3. That is, STA2 may be a hidden node to STA3. By exchanging RTS / CTS frames before performing data transmission and reception between STA1 and STA2, it is possible to prevent a STA outside the transmission range of either STA1 or STA2, or a STA outside the carrier sensing range for transmission from STA1 or STA3, from attempting to occupy the channel during data transmission and reception between STA1 and STA2.

[0091] Specifically, STA1 can determine whether the channel is in use through carrier sensing. In terms of physical carrier sensing, STA1 can determine the channel occupancy idle state based on the energy magnitude or signal correlation detected in the channel. Additionally, in terms of virtual carrier sensing, STA1 can determine the channel occupancy state using a NAV (network allocation vector) timer.

[0092] If the channel is idle during DIFS, STA1 can send an RTS frame to STA2 after performing backoff. If STA2 receives the RTS frame, it can send a CTS frame to STA1 as a response to the RTS frame after SIFS.

[0093] If STA3 cannot overhear a CTS frame from STA2 but can overhear an RTS frame from STA1, STA3 can set a NAV timer for the duration of subsequently transmitted frames (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame) using the duration information included in the RTS frame. Alternatively, if STA3 cannot overhear an RTS frame from STA1 but can overhear a CTS frame from STA2, STA3 can set a NAV timer for the duration of subsequently transmitted frames (e.g., SIFS + data frame + SIFS + ACK frame) using the duration information included in the CTS 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.

[0094] 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.

[0095] FIG. 6 is a drawing for illustrating an example of a frame structure used in a wireless LAN system to which the present disclosure may be applied.

[0096] Based on instructions or primitives (meaning a set of instructions or parameters) from the MAC layer, the PHY layer can prepare the MPDU (MAC PDU) to be transmitted. For example, upon receiving an instruction from the MAC layer requesting the start of transmission, the PHY layer switches to transmit mode and can construct the information provided by the MAC layer (e.g., data) into a frame for transmission. Additionally, if the PHY layer detects a valid preamble of a received frame, it monitors the preamble header and sends an instruction to the MAC layer indicating the start of reception.

[0097] As such, information transmission and reception in wireless LAN systems are carried out in the form of frames, and for this purpose, the Physical Layer Protocol Data Unit (PPDU) format is defined.

[0098] A basic PPDU may include a Short Training Field (STF), a Long Training Field (LTF), a Signal (SIGNAL) field, and a Data field. The most basic (e.g., the non-HT (High Throughput)) PPDU format illustrated in FIG. 7 may consist only of Legacy-STF (Legacy-STF), Legacy-LTF (Legacy-LTF), Legacy-SIG (Legacy-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.

[0099] 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 and frequency error estimation. STF and LTF can be considered signals for synchronization and channel estimation in the OFDM physical layer.

[0100] The SIG field may contain various information related to the transmission and reception of the PPDU. For example, the L-SIG field consists 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 contain information regarding the modulation and coding rates of the data. For example, the 12-bit Length field may contain information regarding 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 non-HT, HT, VHT, or EHT PPDUs, the value of the Length field may be determined as a multiple of 3. For example, for HE PPDUs, the value of the Length field may be determined as a multiple of 3 + 1 or a multiple of 3 + 2.

[0101] The data field may include a SERVICE field, a PSDU (Physical layer Service Data Unit), and PPDU TAIL bits, and may also include padding bits if necessary. Some bits of the SERVICE field may be used for synchronization of the descrambler at the receiver. The PSDU corresponds to a MAC PDU defined at the MAC layer and may contain data generated or used by the upper layer. The PPDU TAIL bits may be used to return the encoder to a 0 state. Padding bits may be used to adjust the length of the data field to a predetermined unit.

[0102] A MAC PDU is defined according to various MAC frame formats, and a basic MAC frame consists of a MAC header, a frame body, and a Frame Check Sequence (FCS). A MAC frame is composed of a MAC PDU and can be transmitted or received through the PSDU of the data portion in the PPDU format.

[0103] The MAC header includes a Frame Control field, a Duration / ID field, an Address field, etc. The Frame Control field may contain control information necessary for transmitting or receiving frames. The Duration / ID field may be set as the time for transmitting the corresponding frame. Address subfields may indicate the frame's receiver address, transmitter address, destination address, and source address, and some address subfields may be omitted. Specific details regarding each subfield of the MAC header, including Sequence Control, QoS Control, and HT Control subfields, can be found in the IEEE 802.11 standard document.

[0104] The Null-Data PPDU (NDP) format refers to a PPDU format that does not include a data field. In other words, NDP is a frame format that includes the PPDU preamble (i.e., L-STF, L-LTF, L-SIG fields, and additionally, non-legacy SIG, non-legacy STF, and non-legacy LTF if present) from a standard PPDU format, but excludes the remaining parts (i.e., the data field).

[0105] FIG. 7 is a drawing illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure may be applied.

[0106] 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)).

[0107] 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 the HT-mixed format. Additionally, an HT-greenfield format PPDU may be defined, which corresponds to a format consisting of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs, and a Data field, without including L-STF, L-LTF, and L-SIG (not shown).

[0108] An example of the VHT PPDU format (IEEE 802.11ac) includes the VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields in addition to the basic PPDU format (Fig. 7(c)).

[0109] An example of the HE PPDU format (IEEE 802.11ax) includes the 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 multiple users (MU), but is not included in the HE PPDU format for single users (SU). Additionally, the HE trigger-based (TB) PPDU format does not include HE-SIG-B, and the length of the HE-STF field may vary to 8 µs. 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 16 µs. For example, RL-SIG can be configured identically to L-SIG. Based on the presence of RL-SIG, the receiving STA can determine that the received PPDU is a HE PPDU or the EHT PPDU described later.

[0110] The EHT PPDU format may include the EHT MU (multi-user) 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 RL-SIG following L-SIG, but it may include U (universal)-SIG, EHT-SIG, EHT-STF, and EHT-LTF following RL-SIG.

[0111] The EHT MU PPDU of FIG. 7(e) corresponds to a PPDU that carries one or more data (or PSDU) for one or more users. That is, the EHT MU PPDU can be used for both SU transmission and MU transmission. For example, the EHT MU PPDU can correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0112] The EHT-SIG is omitted in the EHT TB PPDU of FIG. 7(f) compared to the EHT MU PPDU. A STA that receives 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] U-SIGs can be configured in 20 MHz units. For example, if an 80 MHz PPDU is configured, the same U-SIG can be duplicated in 20 MHz units. That is, four identical U-SIGs can be included within an 80 MHz PPDU. If the bandwidth exceeds 80 MHz, for example, for a 160 MHz PPDU, the U-SIG of the first 80 MHz unit and the U-SIG of the second 80 MHz unit may be different.

[0117] For example, A number of uncoded bits may be transmitted through U-SIG, and the first symbol of U-SIG (e.g., U-SIG-1 symbol) transmits the first X bits of the total A bit information, and the second symbol of U-SIG (e.g., U-SIG-2 symbol) transmits the remaining Y bits of the total A bit information. The A bit information (e.g., 52 uncoded bits) may include a CRC field (e.g., a field of 4 bits) and a tail field (e.g., a field of 6 bits). The tail field may be used to terminate the trellis of the convolution decoder and may be set to, for example, 0.

[0118] A bit information transmitted by U-SIG can be divided into version-independent bits and version-dependent bits. For example, U-SIG may be included in a new PPDU format not shown in FIG. 7 (e.g., UHR PPDU format), 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 may be the same, and some or all of the version-dependent bits may be different.

[0119] For example, the size of the version-independent bits of U-SIG may be fixed or variable. The version-independent bits may be assigned only to U-SIG-1 symbols or to both U-SIG-1 and U-SIG-2 symbols. The version-independent bits and version-dependent bits may be referred to by various names, such as the first control bit and the second control bit.

[0120] For example, the version-independent bits of U-SIG may include a 3-bit physical layer version identifier (PHY version identifier), and this information may indicate the PHY version of the transmitted / received PPDU (e.g., EHT, UHR, etc.). The version-independent bits of 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 U-SIG may include information regarding the length of the TXOP (transmission opportunity) and information regarding the BSS color ID.

[0121] For example, the version-dependent bits of U-SIG may contain information that directly or indirectly indicates the type of PPDU (e.g., SU PPDU, MU PPDU, TB PPDU, etc.).

[0122] Information necessary for PPDU transmission and reception may be included in the U-SIG. For example, the U-SIG may further include information regarding bandwidth, information regarding MCS techniques applied to non-legacy SIGs (e.g., EHT-SIG or UHR-SIG, etc.), information indicating whether DCM (dual carrier modulation) techniques (e.g., techniques to achieve an effect similar to frequency diversity by reusing the same signal on two subcarriers) are applied to non-legacy SIGs, information regarding the number of symbols used for non-legacy SIGs, and information regarding whether non-legacy SIGs are generated across the entire band.

[0123] 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.

[0124] Preamble puncturing may refer to the transmission of a PPDU in which a signal is not present in one or more frequency units within the PPDU bandwidth. For example, the size of the frequency unit (or the resolution of preamble puncturing) may be defined as 20 MHz, 40 MHz, etc. For example, preamble puncturing may be applied to a PPDU bandwidth of a predetermined size or larger.

[0125] 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. A non-legacy SIG may be transmitted through at least one symbol, and one symbol may have a length of 4 µs. Information regarding the number of symbols used for EHT-SIG may be included in the previous SIG (e.g., HE-SIG-A, U-SIG, etc.).

[0126] Non-legacy SIGs, such as HE-SIG-B and EHT-SIG, may include common fields and user-specific fields. Common fields and user-specific fields may be coded individually.

[0127] In some cases, the common field may be omitted. For example, in a compression mode where non-OFDMA (orthogonal frequency multiple access) is applied, the common field may be omitted, and multiple STAs may receive PPDUs (e.g., the data field of the PPDU) over the same frequency band. In a non-compression mode where OFDMA is applied, multiple users may receive PPDUs (e.g., the data field of the PPDU) over different frequency bands.

[0128] 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 may be related to MU-MIMO allocation or non-MU-MIMO allocation.

[0129] The common field may include CRC bits and Tail bits, the length of the CRC bits may be determined to be 4 bits, and the length of the Tail bits may be determined to be 6 bits and set to 000000. The common field may include RU allocation information. The RU allocation information may include information regarding the location of the RU to which a plurality of users (i.e., a plurality of receiving STAs) are allocated.

[0130] An RU may include multiple subcarriers (or tones). An RU may be used when transmitting signals to multiple STAs based on the OFDMA technique. Additionally, an RU may be defined when transmitting signals to a single STA. Resources may be allocated on an RU basis for non-legacy STF, non-legacy LTF, and Data fields.

[0131] Applicable RU sizes can be defined according to the PPDU bandwidth. RUs 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 80 MHz PPDU, the RU placement for HE PPDU and EHT PPDU may differ. The applicable RU sizes, number of RUs, RU locations, DC (direct current) subcarrier locations and numbers, null subcarrier locations and numbers, and guard subcarrier locations and numbers for each PPDU bandwidth can be referred to as a tone-plan. For example, a tone-plan for a wide bandwidth may be defined as a multiple repetition of a tone-plan for a low bandwidth.

[0132] RUs of various sizes can be defined as 26-ton RUs, 52-ton RUs, 106-ton RUs, 242-ton RUs, 484-ton RUs, 996-ton RUs, 2x996-ton RUs, 4x996-ton RUs, etc. An MRU (multiple RU) is distinguished from multiple individual RUs and corresponds to a group of subcarriers composed 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. In addition, multiple RUs constituting a single MRU may be continuous or non-continuous in the frequency domain.

[0133] 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.

[0134] The names of the respective fields in the PPDU formats of FIG. 7 are exemplary and the scope of the present disclosure is not limited by such names. Furthermore, the examples of the present disclosure may be applied not only to the PPDU formats exemplified in FIG. 7, but also to new PPDU formats based on the PPDU formats of FIG. 7 in which some fields are excluded and / or some fields are added.

[0135] Multi-link operation

[0136] The following describes the multi-link (ML) operations supported by the STA according to the present disclosure.

[0137] The STA (AP STA and / or non-AP STA) described in this disclosure may support multi-link (ML) communication. ML communication may refer to communication that supports multiple links. The links involved in ML communication may include channels (e.g., 20 / 40 / 80 / 160 / 240 / 320 MHz channels) in the frequency band (e.g., 2.4 GHz band, 5 GHz band, 6 GHz band, etc.) in which the STA operates. The multiple links used for ML communication may be configured in various ways. For example, the multiple links supported by a single STA for ML communication may belong to the same frequency band or to different frequency bands. Additionally, each link may correspond to a frequency unit of a predetermined size (e.g., channel, subchannel, RU, etc.). Furthermore, some or all of the multiple links may be frequency units of the same size or frequency units of different sizes.

[0138] When a single STA supports multiple links, the transmitting and receiving devices supporting each link can operate as a single logical STA. That is, an MLD refers to a device that, as a logical entity, has one or more affiliated STAs and a single MAC Service Access Point (SAP) for a single MAC data service and logical link control (LLC). A non-AP MLD refers to an MLD where each STA affiliated with the MLD is a non-AP STA. A multi-radio non-AP MLD refers to a non-AP MLD that supports the reception or exchange of frames on one or more links at a time. An AP MLD refers to an MLD where each STA affiliated with the MLD is an AP STA.

[0139] Multi-Link Operation (MLO) can enable a non-AP MLD to discover, authenticate, associate, and set up multiple links for an AP MLD. Based on the supported capabilities exchanged during the association process, each link can enable channel access and frame exchange between the non-AP MLD and the AP MLD. An STA affiliated with an MLD can select and manage its capabilities and operation parameters independently of other STA(s) affiliated with the same MLD.

[0140] Through a multi-link setup process, the AP MLD and / or non-AP MLD can transmit and receive link-related information that the MLD can support. The link-related information may include one or more of the following: whether simultaneous transmit and receive (STR) operations that allow simultaneous transmission and receive on multiple links supported by the MLD, or non-simultaneous transmit and receive (NSTR) operations that do not allow simultaneous transmission and receive; information regarding the number / upper limit of UL / DL links; information regarding the location / band / resource of UL / DL links; information regarding frame types available or preferred on at least one UL / DL link (e.g., management, control, data, etc.); information regarding ACK policies available or preferred on at least one UL / DL link; or information regarding traffic identifiers (TID) available on at least one UL / DL link.

[0141] An AP MLD (e.g., an NSTR mobile AP MLD) may set one of the multiple links as the primary link. The AP MLD may perform beacon frames, probe response frames, and group-addressed data frames only on the primary link. The remaining other links of the multiple links may be non-primary links. An AP MLD operating on a non-primary link may operate so as not to transmit beacon frames or probe response frames. Additionally, a non-AP MLD may perform frame exchange during authentication, (re)association, and 4-way handshake only on the primary link.

[0142] A setup link is defined as enabled if at least one traffic identifier (TID) is mapped to the link through the multi-link setup process, and may be defined as disabled if no TID is mapped to the link. A TID must always be mapped to at least one setup link unless admission control is used. By default, TIDs are mapped to all setup links, so all setup links can be enabled.

[0143] When a link is activated, it may be used for frame switching depending on the power state of the non-AP STA operating on that link. Only MSDUs or A-MSDUs with TIDs mapped to the activated link may be transmitted on that link. Management frames and control frames may only be transmitted on the activated link.

[0144] If a link is disabled, it may not be used for frame exchange, including management frames for both DL and UL.

[0145] During the multi-link setup process, the activation / deactivation of each link can be directed through TID-to-Link mapping. TID-to-Link mapping can be performed in default mapping mode or / and negotiation mapping mode.

[0146] One of the STAs belonging to the MLD may provide information about one or more links other than the link where it is located for multi-link discovery (e.g., obtaining information about multiple links including the link on a single link) or multi-link setup (e.g., associating simultaneously on multiple links through the exchange of association request / response frames on a single link). To provide this information, a multi-link (ML) element may be defined.

[0147] FIG. 8 illustrates, exemplarily, the structure of an ML element to which the present disclosure can be applied.

[0148] In an ML element, the element ID field and the element ID extension field may have specific values ​​(e.g., 255 and 107) indicating that it is an ML element, and the length field may have a value indicating the length of the remaining fields excluding the element ID field and the length field (e.g., in octets).

[0149] The multi-link control field is defined as having a size of 2 octets and may include a 3-bit type subfield, a 1-bit reserved bit, and a 12-bit presence bitmap subfield. The type subfield may have a value indicating one of the types, such as basic, probe request, reconfiguration, tunneled direct-link setup (TDLS), or priority access. The presence bitmap subfield indicates the presence of various subfield(s) within the common info field and may be defined in different formats depending on the various variants (or types mentioned above) of the ML element.

[0150] The common info field is defined as having a variable size and may include a 6-octet MLD MAC address subfield, which may have a value specifying the MAC address of the MLD to which the STA transmitting the basic ML element belongs. Additionally, the link ID info subfield, BSS parameter change count subfield, medium synchronization delay information subfield, enhanced multi-link (EML) capability subfield, MLD capability subfield, etc., may or may not be included in the common info field.

[0151] The link info field is defined as having a variable size and may contain link-specific information and may be optional. If the link info field is present, it may contain one or more subelements. The format and order of the subelements may be defined in various ways. As an example of optional subelement IDs for a basic variant ML element, a subelement ID value of 0 corresponds to the name of the per-STA profile and is extensible, a value of 221 corresponds to the name of the vendor-specific and its extensibility may be determined by the vendor, and the remaining values ​​1-220 and 222-255 may be reserved.

[0152] The STA-per-profile sub-element may include a 1-octet sub-element ID sub-field, a 1-octet length sub-field, a 2-octet STA control sub-field, a variable-size STA info sub-field, and a variable-size STA profile sub-field. The STA control sub-field may include information such as a link ID, whether a complete profile is included, and whether a STA MAC address exists. The STA info sub-field may include information such as a STA MAC address. The STA profile sub-field may include information included in the probe response or probe request frame body, information included in the (re)join response or (re)join request frame body, depending on whether the reported STA is an AP STA or a non-AP STA.

[0153] The format of the ML element in Fig. 8 is exemplary, and the order, names, sizes, etc. of the fields / subfields may be changed, additional fields / subfields may be defined, or some fields / subfields may be excluded. In short, the common information field contains information common among the STAs within the MLD, and the link information field may contain specific information for each STA / link (e.g., in the per-STA profile subelement containing the link ID corresponding to the STA).

[0154] Dynamic Power Save (DPS) operation

[0155] In next-generation wireless LAN systems, DPS operation can be performed to save power for AP / STA. Through DPS operation, a DPS STA (e.g., a STA with DPS mode enabled) can operate with lower capability in LC (low capability) mode to reduce power consumption, and after switching to HC (high capability) mode, can perform frame exchange using the operation parameters of HC mode.

[0156] Here, HC mode is a mode used by the STA to perform frame exchange with the peer STA after receiving an initial control frame from the peer STA within a TXOP. In this case, the STA may use a bandwidth not greater than its operating bandwidth and a spatial stream number not greater than its receiving (Rx) spatial stream number (NSS). Additionally, LC mode may be a mode in which the STA uses the bandwidth, spatial stream number, PPDU format, and (if possible) modulation and coding scheme (MCS) supported by its LC mode. That is, the STA can reduce power consumption by dynamically switching between LC mode and HC mode through DPS operation based on data processing requirements or / and operation / procedure types.

[0157] The capabilities reduced in LC mode may be related to bandwidth, NSS, MCS (modulation coding scheme), and / or PPDU format. A DPS STA may switch to HC mode upon receiving an ICF from a DPS assisting STA under specific conditions. Here, the DPS STA may be either a DPS non-AP STA or a DPS mobile AP.

[0158] For example, a non-AP UHR STA with a "dot11UHRDPSAssistingImplemented" value of 1 is called a DPS assisting non-AP STA, and such STA can set the 'DPS Assisting Support' field value within the UHR capability element of the management frame it transmits to 1. Also, a UHR AP with a dot11UHRDPSAssistingImplemented value of 1 is called a DPS assisting AP, and such AP can set the 'DPS Assisting Support' field within the UHR capability element of the management frame it transmits to 1. Otherwise, the UHR AP or non-AP STA can set the 'DPS Assisting Support' field value to 0.

[0159] Through DPS operation, the DPS STA can operate in LC mode and can switch to HC mode as soon as it receives the ICF transmitted by the combined AP.

[0160] A DPS non-AP STA in HC mode can receive and transmit the same PPDU as when the non-AP STA has not enabled DPS mode.

[0161] When a DPS non-AP STA enables DPS by setting the 'ICF Required' field to 0, if a DPS assisting AP intends to transmit to a DPS STA in HC mode, the AP can initiate frame exchange with the DPS non-AP STA by transmitting the ICF.

[0162] That is, as long as the frames use parameters that match the LC mode of the DPS non-AP STA, the DPS-enabled AP can exchange frames with the DPS non-AP STA without needing to transmit an ICF. If the DPS STA is operating on an EMLSR (enhanced multi-link single radio) link, the DPS non-AP STA may not enable DPS by setting the 'ICF Required' field to 0. If the DPS non-AP STA enables DPS by setting the 'ICF Required' field to 1, the DPS-enabled AP may initiate all frame exchanges with the DPS STA by transmitting an ICF. That is, the DPS-enabled STA may not be able to perform frame exchanges with the DPS STA unless an ICF precedes them.

[0163] Critical Update Procedure

[0164] In a basic wireless LAN system, if at least one element is added, modified, or changed on a beacon frame or / and a probe response frame, it can be identified by a STA (e.g., a non-AP STA and / or AP) that a critical update has occurred.

[0165] For example, the following events regarding the BSS parameter(s) of an AP can be classified as critical updates:

[0166] - Inclusion of Channel Switch Announcement elements,

[0167] - Includes Extended Channel Switch Announcement element;

[0168] - Modification of EDCA parameter elements;

[0169] - Includes Quiet element;

[0170] - Modify DSSS parameters;

[0171] - Modify HT operation elements;

[0172] - Includes Wide Bandwidth Channel Switch element;

[0173] - Includes Channel Switch Wrapper element;

[0174] - Includes Operating Mode Notification element;

[0175] - Includes quiet channel element;

[0176] - Modification of VHT operation elements;

[0177] - Modification of HE action elements;

[0178] - Broadcast TWT(Target Wake Time) element insertion;

[0179] - Insert or remove broadcast TWT parameter set fields within broadcast TWT elements;

[0180] - Includes BSS Color Change Announcement element;

[0181] - Modify MU EDCA parameter set elements;

[0182] - Modify Spatial Reuse parameter set elements;

[0183] - Modify UORA parameter set elements;

[0184] - Insert Index Adjustment Factor field within Multiple BSSID Configuration element;

[0185] - Modification of EHT (Extremely High Throughput) operation elements; and

[0186] - If the AP is an EHT AP, include, modify, or remove the Transmit Power Envelope element.

[0187] The STA recognizes that a critical update has occurred and can identify the modified, changed, or / and added parts of the IE(s) through the frame containing the IE(s). In particular, when multi-link is applied, instructions and / or information regarding the occurrence of a critical update in another link may be transmitted from one link to the STA(s).

[0188] FIG. 9 is a diagram illustrating a critical update procedure. Specifically, FIG. 9 illustrates a critical update procedure for affiliated AP 1 and affiliated AP 2 of a single AP MLD. Here, AP 2 may be a reporting AP and AP 1 may be a reported AP, but is not limited thereto. AP 1 may be a reporting AP and AP 2 may be a reported AP.

[0189] Also, FIG. 10 is a diagram illustrating the format of an MLD parameter subfield. For example, as shown in FIG. 10, an MLD parameter subfield transmitted by AP 2 (e.g., an MLD parameter subfield included in the RNR element of a beacon frame / probe response frame of AP 2) may include an AP MLD ID subfield, a link ID subfield, a BSS parameter change count (BPCC) subfield, an All Updates included subfield, a disabled link indication subfield, etc.

[0190] Here, the AP MLD ID subfield may indicate the identifier of the AP MLD to which AP 1 / 2 belongs. The Link ID subfield may indicate the link identifier of AP 1 / 2 within the AP MLD to which AP 1 / 2 belongs. The BPCC subfield is an unsigned integer, initialized to 0, and may be incremented whenever a critical update occurs to the BSS parameter of AP 1 / 2. The All Updates Included subfield may indicate whether the updated element corresponding to the latest critical update that changed the value of the BPCC subfield for AP 1 / 2 is included in the frame containing the RNR element.

[0191] The beacon frames and / or probe response frames transmitted by AP 2 may include information on critical update occurrences for AP 1 belonging to the same MLD (e.g., BPCC information, critical update flag information, information including all updates). For example, the critical update occurrence information may be included in the reduced neighbor report (RNR) IE, capability information fields and / or basic multi-link IE within the beacon frames and / or probe response frames.

[0192] For example, whenever a critical update occurs for AP 1, the count value can be increased by 1 through the BPCC for AP 1. Referring to Fig. 9, when an update of the EHT operation IE occurs at or before the time AP 1 transmits beacon frame 12, the BPCC value in AP 2's beacon frame 22 can be increased from 5 to 6. Additionally, when a Quiet IE is newly included in AP 1's beacon frame 13, the BPCC value in AP 2's beacon frame 23 can be increased from 6 to 7. Therefore, STA 1 connected / coupled with AP 2 can determine how many critical updates (e.g., critical updates for AP 1 or / and AP 2) have occurred based on the increased BPCC value.

[0193] Additionally, the critical update flag field included in the capability information field of the AP 2 beacon frame / probe response frame can be set / indicated to 1 when a change in the BPCC of the RNR IE occurs. The critical update flag field can be set to prevent passing of the RNR IE.

[0194] For example, the capability update flag field value set to 1 can be maintained until the next DTIM (Delivery Traffic Indication Message) so that all STAs receiving the beacon frame / probe response frame can identify the RNR IE (or / and information related to critical updates). Thus, in the example illustrated in FIG. 9, the capability update flag value can be maintained at 1 from the time the critical update of AP 1 occurs until beacon frame 25, which is the next DTIM beacon of AP 2.

[0195] Additionally, if a critical update occurs as IEs related to channel switching and / or Quiet are included in the beacon frame / probe response frame of AP 1, AP 2 may include the IEs related to channel switching and / or Quiet in the STA-per-profile corresponding to AP 1 among the underlying multi-link (ML) elements.

[0196] For example, referring to FIG. 9, when an IE related to Quiet is included in the beacon frame of AP 1, an IE related to Quiet for AP 1 may be included starting from the beacon frame 23 of AP 2. Additionally, to indicate that an IE corresponding to a critical update for AP 1 is included in the underlying ML IE, the field value of all updates included in the RNR IE corresponding to AP 2 may be set to 1.

[0197] In a next-generation wireless LAN system (e.g., a wireless LAN system after IEEE 802.11 be), the update / addition / deletion of at least one technology / feature can also be classified / identified as a critical update. However, if the BPCC subfield and the critical update flag subfield described with reference to FIGS. 9 and FIGS. 10 are reused for the critical update, STAs prior to the next-generation wireless LAN system may not understand / recognize the situation related to the critical update.

[0198] For example, a change in the parameter(s) of the dynamic power save (DPS), a UHR feature, can be classified / identified as a critical update. In this case, even if the AP reporting the critical update increments the count of the BPCC on its frame (e.g., beacon frame / probe response frame) and sets the critical update flag value to 1, the STA(s) in the pre-UHR format may not understand the critical update details.

[0199] Therefore, the BPCC for critical updates related to UHR features needs to be defined differently from the BPCC defined in the basic wireless LAN system.

[0200] Additionally, parameter(s) for a specific technology / feature can be considered as parameters that do not change frequently. In particular, including parameters related to a specific technology / feature in the beacon frame or / and probe response frame in every cycle whenever a specific technology / feature is added can lead to bloating issues.

[0201] Non-AP STA / AP can basically acquire and / or decode currently operating parameters through probe request / response frames and / or combination request / response frames. In particular, when the defined ML probe request / response frames and multi-link setup process are performed in an EHT-based wireless LAN system, the STA can identify and decode parameters of not only the connected / combined AP but also other APs within the AP MLD.

[0202] Broadcasting parameter(s) that the STA already recognizes in the beacon frame every time can cause unnecessary overhead. Therefore, if the parameter(s) are classified as critical update targets and selectively signaled only when an addition, modification, or change of the parameter(s) occurs, beacon overhead can be reduced.

[0203] Below, we will describe a new (or improved) critical update method to solve the aforementioned beacon blotting problem.

[0204] In describing the present disclosure, the names of each field and / or information may be changed, and STA may include / refer to non-AP STA or STA. Also, RU may refer to MRU as well as RU.

[0205] As an example of the present disclosure, when a non-AP STA that supports DPS mode (re)couples with an AP, the DPS mode of said non-AP STA may be disabled by default. A non-AP UHR STA that supports DPS mode and enables, disables, or updates parameters of the DPS mode may perform the procedure described below.

[0206] In a UHR OMP (operating mode and parameters) request transmitted to enable the DPS mode of a non-AP STA or to update parameters, the non-AP STA may include a 'DPS operation parameter' field. The coupled AP may accept the request and perform an operation according to the procedure described below. Here, in order for the non-AP STA to enable the DPS mode, the AP coupled to the non-AP STA may be a DPS assisting AP.

[0207] Events related to the BSS parameters of an AP (e.g., insertion of UHR parameter update elements) may be classified as improved critical updates. That is, in describing the present disclosure, improved critical updates may be expressed as updates related to the insertion of UHR parameter update elements or UHR (critical) updates, etc.

[0208] And, "critical update" may be expressed as "basic update" or "EHT, HE, VHT and / or HT (critical) update", etc. Critical update may collectively refer to events for the aforementioned event(s).

[0209] FIG. 11 is a flowchart illustrating a method performed by a first AP according to one embodiment of the present disclosure.

[0210] In FIGS. 11 and FIGS. 12, the first AP and the second AP may each be affiliated with the same AP MLD, but are not limited thereto. Additionally, the first AP may be a transmitting AP or a reporting AP, but is not limited thereto.

[0211] The first AP can generate a first frame containing UHR parameter update elements (S1110).

[0212] And, the first AP can transmit the first frame (S1120). At this time, the first AP can transmit the first frame to at least one STA coupled to the first AP.

[0213] In describing the present disclosure, each of the first frame and / or the second frame may include, but is not limited to, a beacon frame, a probe response frame, or / and an association response frame. That is, the first frame described below may be represented as a first beacon frame, a first probe response frame, or a first association response frame.

[0214] Here, the first frame may include an enhanced critical updates flag field set to 1 and an enhanced all updates included field related to the UHR parameter update element.

[0215] Additionally, the first frame includes an improved BSS parameter change count field and a critical update type field, and the field containing all improved updates may be included in the improved critical update information field of the first frame. And, the improved critical update flag field may be included on the capability information field of the first frame.

[0216] Here, the Critical Update Type field may indicate the type of (improved) critical update. For example, the Critical Update Type field set to 0 may indicate that there is no UHR update. The Critical Update Type field set to 1 may indicate an update of at least one UHR mode operation. The Critical Update Type field may be set / indicated based on the EHT CUF, UHR CUF, and / or UCUF described below.

[0217] For example, when the first AP initiates a procedure for DPS operation (e.g., an advance notification procedure) at a (specific) target beacon transmission time (TBTT), the first AP can transmit a first frame.

[0218] Here, the procedure for DPS operation may include a prior notification procedure for enabling, disabling, or updating at least one parameter for DPS.

[0219] In one example of the present disclosure, at least one parameter may include at least one of a minimum padding duration required to switch from a low capability (LC) mode to a high capability (HC) mode, an amount of time required to switch from the HC mode to the LC mode, first information regarding whether transmission of an initial control frame (ICF) is required before performing a DPS operation, second information regarding a mode related to the DPS operation (e.g., a parameterized mode), a maximum bandwidth supported for the DPS operation, a maximum number of spatial streams supported for the DPS operation, or a maximum modulation and coding scheme (MCS) supported for the DPS operation.

[0220] And, at least one field may include at least one of a DPS padding delay field in which the minimum padding interval is set, a DPS switching delay field in which the amount of time required to switch from HC mode to LC mode is set, a first field in which the first information is set, a second field in which the second information is set, a third field in which the maximum bandwidth is set, a fourth field in which the number of the maximum spatial streams is set, or a fifth field in which the maximum MCS value is set.

[0221] Specifically, the minimum padding interval may be the minimum MAC padding interval (duration) required to cause the first STA (e.g., DPS STA) / first AP in the ICF to switch from LC mode to HC mode, and may be set in units of 4 us. The minimum padding interval may be set / indicated by the DPS padding delay field.

[0222] The amount of time required to switch from the HC mode to the LC mode may be the amount of time required for the first STA / first AP to switch from the HC mode to the LC mode, and may be set in units of 4 us. The amount of time required to switch from the HC mode to the LC mode may be set / indicated by the DPS switching delay field.

[0223] The first information above may indicate whether the STA (e.g., the first STA and / or AP) must transmit an ICF to the peer STA before performing frame exchange with the peer STA in the TXOP. As described above, the first information may be set / indicated by the first field (e.g., the "ICF Required" field).

[0224] The above maximum bandwidth refers to the maximum bandwidth supported by the first STA / first AP in LC mode, and this can be set / indicated by the third field (e.g., "bandwidth field"). The above maximum number of spatial streams indicates the maximum number of spatial streams supported by the first STA / first AP in LC mode, and this can be set / indicated by the fourth field (e.g., "number of spatial streams field"). The above maximum MCS indicates the highest MCS supported by the first STA / first AP in LC mode, and this can be set / indicated by the fifth field (e.g., "MCS field").

[0225] In describing the present disclosure, the AP that the parameter(s) associated with the DPS described above enable, disable, or / and update may be collectively referred to as the affected AP. That is, the affected AP may be a first AP or a second AP.

[0226] As an example of the present disclosure, when a first AP in TBTT initiates a procedure related to DUO mode (e.g., a prior notification procedure), a first beacon frame generated / transmitted by the first AP may be configured as described below.

[0227] For example, the capability information field of the first frame may include an improved critical update flag field (e.g., the third bit (B2) of the capability information field) and a critical update flag field (e.g., the seventh bit (B6) of the capability information field). In this case, the improved critical update flag field may be collectively referred to as the UHR CUF (or UCUF) or the first (critical) update flag field, and the critical update flag field may be collectively referred to as the EHT CUF or the second (critical) update flag field, but is not limited thereto.

[0228] For example, if the first AP in TBTT initiates a procedure related to a DPS operation, the enhanced critical update flag field value may be set to 1. Otherwise, the enhanced critical update flag field value may be set to 0.

[0229] And, the first AP can increase the Enhanced BSS Parameter Change Count field value corresponding to each affected AP by 1. And, the first AP can set the Critical Update Type field value corresponding to each affected AP to 1 and set the Enhanced All Updates field value to 1.

[0230] For example, if the affected AP is a colocated UHR AP (or / and a second AP), the 'improved BSS parameter change count field', 'critical update type field', and 'improved all updates included field' may be carried in the improved critical update information field included in the TBTT information field of the RNR (Reduced Neighbor Report) element of the first beacon frame.

[0231] That is, based on the fact that the improved BSS parameter change count field and the critical update type field are related to the second AP (e.g., based on the fact that the operation / procedure related to the DPS operation is related to the second AP), the improved critical update information field (e.g., the improved BSS parameter change count field, the critical update type field and / or the improved all update inclusion field, etc.) may be included in the TBTT information field of the RNR element of the first frame.

[0232] In another example of the present disclosure, if the affected AP is a transmitting AP (e.g., the first AP) or an AP corresponding to a nontransmitted BSSID within the same multi-BSID set as the transmitting AP, the 'enhanced BSS parameter change count field', the 'critical update type field', and the 'enhanced all updates included field' may be carried in the enhanced critical update information field included in the common information field of the Basic Multi-Link element of the first beacon frame.

[0233] That is, based on the fact that the improved BSS parameter change count field and the critical update type field are associated with the first AP or the AP (e.g., the third AP) corresponding to the untransmitted BSSID within the same multi-BSID set as the first AP (e.g., based on the fact that the operation / procedure associated with the DUO mode is associated with the first AP), the improved critical update information field (e.g., the improved BSS parameter change count field, the critical update type field, and / or the improved all update inclusion field, etc.) may be included in the common information field of the basic multi-link element of the first beacon frame.

[0234] In addition, the improved critical update information field of the first frame may include an improved BSS parameter change count field, a critical update type field, and a field containing all improved updates.

[0235] Additionally, the UHR parameter update element of the first frame may include an element ID field, a length field, a length ID extension field, a timer field (e.g., a countdown timer field), and a field related to the DUO mode (e.g., a mode-specific parameter field for the DUO format).

[0236] Here, the timer field may relate to / indicate the number of TBTTs up to a specific TBTT in which the update indicated in the UHR parameter update element takes effect on the first AP or the second AP. Here, the specific TBTT may be the TBTT in which the procedure for the at least one operation is initiated, but is not limited thereto.

[0237] The first AP may begin including UHR parameter update elements in specific frames (e.g., beacon frames, etc.) starting from a specific period prior to the time when operations / procedures related to DPS are scheduled to be performed. At this time, the specific period may be fixed for the AP MLD to which the first AP and the second AP belong. Additionally, UHR parameter update elements may be continuously included (followed) up to that time, including the DTIM (Delivery Traffic Indication Map) beacon immediately after the TBTT where operations / procedures related to DUO mode occur.

[0238] For example, the values ​​set in the improved BSS parameter change count field, the critical update type field, and the improved all update included field, respectively, can be maintained until the next DTIM beacon (from a specific TBTT).

[0239] For example, UHR parameter update elements may be included on a Per-STA profile corresponding to the first AP or second AP of the first frame.

[0240] As an example of the present disclosure, an improved critical update information present (sub)field may be included on the presence bitmap subfield or STA control field of the underlying multi-link element of the first frame.

[0241] For example, the Improved Critical Update Information Existence subfield can be set to 1 if the Improved Critical Update Information subfield exists in the Common Information field of the base multilink element. Otherwise, the Improved Critical Update Information Existence subfield can be set to 0.

[0242] At this time, a non-AP STA that is not an AP can set the value of the enhanced critical update information existence subfield in the basic multilink element it transmits to 0.

[0243] After the DTIM beacon immediately following the TBTT in which at least one of the above operations occurs, the first AP may include UHR parameter update elements on the beacon frame during an additional beacon interval. From then until the procedure for the operation related to the next DUO mode (e.g., advance notification procedure) begins, the UHR parameter update elements may not be included on the subsequent frame (e.g., the second frame).

[0244] The method described in the example of FIG. 11 can be performed by the first device (100) of FIG. 1. That is, the first AP of FIG. 11 can be implemented by the first device (100) of FIG. 1. For example, one or more processors (102) of the first device (100) of FIG. 1 can generate a first frame including UHR parameter update elements. One or more processors (102) can transmit the first frame through one or more transceivers (106).

[0245] Furthermore, one or more memories (104) of the first device (100) may store instructions for performing the method described in the example of FIG. 11 or the examples described below when executed by one or more processors (102).

[0246] FIG. 12 is a flowchart illustrating a method performed by a first STA according to one embodiment of the present disclosure. As described above, the first STA may be coupled to a first AP, but is not limited thereto.

[0247] The first STA can receive a first frame containing UHR parameter update elements from the first AP (S1210).

[0248] And, the first STA can decode the first frame (S1220).

[0249] The first STA can identify that a procedure for a DPS operation related to the first AP or the second AP is initiated as it decodes the first frame.

[0250] The first STA can identify / recognize information related to the enable, disable, or update of at least one parameter for the DPS included in the UHR parameter update element. That is, the first STA can verify the enable, disable, or update of the parameter(s) related to the DPS by decoding at least one field on the UHR parameter update element.

[0251] The method described in the example of FIG. 12 can be performed by the second device (200) of FIG. 1. That is, the first STA of FIG. 12 can be implemented by the second device (200) of FIG. 1. For example, one or more processors (202) of the second device (200) of FIG. 1 can receive a first frame containing UHR parameter update elements from the first AP through one or more transceivers (206). One or more processors (202) can decode the first frame.

[0252] Furthermore, one or more memories (204) of the second device (200) may store instructions for performing the method described in the example of FIG. 12 or the examples described below when executed by one or more processors (202).

[0253] The following describes in detail the enhanced critical update procedure and information related to said procedure.

[0254] Example 1

[0255] Example 1 relates to a critical update flag associated with an improved critical update procedure.

[0256] For a critical update flag for a wireless LAN system after an EHT-based wireless LAN system (e.g., a UHR-based wireless LAN system, etc.), at least one of the embodiments described below (e.g., Embodiment 1-1 and Embodiment 1-2) may be used.

[0257] Additionally, a change in the critical update flag value may indicate that the BPCC related to a specific feature / technology applied to the wireless LAN system classified as a critical update has changed. Furthermore, information / values ​​related to the critical update flag may be applied at the MLD level. That is, if the BPCC for at least one STA belonging to the MLD has changed, the information related to the critical update flag may change.

[0258] Example 1-1

[0259] In one embodiment of the present disclosure, a unified critical update flag (UCUF) field may be set in the reserved bit(s) of the capability information field (e.g., the 3rd bit (B2), the 4th bit (B3), the 15th bit (B14) and the 16th bit (B15)) or the reserved bit of the extended capability field of the extended capability element (e.g., the 5th bit (B4) through the 7th bit (B6), the 42nd bit (B41) through the 44th bit (B43) and the 112th bit (B11) or higher).

[0260] Here, the UCUF field is represented as an enhanced critical update flag field, and the EHT CUF field can be represented as a critical update flag field. Also, the EHT CUF field can be set to the 7th bit (B6) of the capability information field, but is not limited thereto.

[0261] In addition, capability information fields including UCUF fields and / or EHT CUF fields may be included in the various types of management frames described above (e.g., beacon frames, probe request / response frames, (re)join request / response frames, etc.).

[0262] The UCUF field may have X bits (where X is 2, 3, 4, or more), and depending on the UCUF field value, it may indicate that a critical update is being considered / applied in the description / feature of a specific type of standard / format. For example, when X is 2 bits, each field (e.g., UCUF field and EHT CUF field) and the information encoded / mapped accordingly may be configured as shown in Table 1.

[0263] UCUFEHT CUF Critical Update Occurrence Standard / Format Description 00 Nothing Critical update does not occur 01 EHT STA can understand / identify 10 (only) UHRUHR STA can understand / identify 11 Critical updates have occurred for UHR and EHTUHR features and EHT features. That is, UHR STA can understand / identify UHR features, and EHT STA can understand / identify EHT features. 20 (only) Next UHR Next UHR STA can understand / identify 21 Critical updates have occurred for EHT and Next UHR Next UHR features and EHT features. That is, Next UHR STA can understand / identify Next UHR features, and EHT STA can understand / identify EHT features.

[0264] In Table 1, EHT features include features / parameters / information defined / applied in EHT-based wireless LAN systems, UHR features include features / parameters / information defined / applied in UHR-based wireless LAN systems, and the following UHR features may include features / parameters / information defined / applied in the following UHR-based wireless LAN systems. As an example of the present disclosure, Table 1 discloses up to the case where the UCUF value is 2, but subsequent values ​​may also be applied to subsequent standards / formats.

[0265] Additionally or alternatively, if the UCUF value is 1 or greater (e.g., if a critical update has occurred to the features of 2 or more standards / formats among UHR or higher standards / formats), at least one of the methods described below may be applied:

[0266] i) The UCUF value may be set based on the standard / format of the lowest version / generation. For example, if a critical update occurs simultaneously for the next UHR feature and each of the UHR features, the UCUF value may be set to a value associated with the UHR feature (e.g., 1). In this case, the next UHR STA can recognize that a critical update corresponding to the next UHR feature has occurred through the UCUF value.

[0267] ii) When the UCUF value is 2 or greater, a STA of a version / generation earlier than the version / generation corresponding to the UCUF value can understand the meaning corresponding to the UCUF value. For example, the STA can recognize and confirm that a critical update has occurred regarding a feature / technology related to the standard / format of the version / generation corresponding to the STA. For example, when the UCUF value is 2, a UHR STA can recognize and confirm that a critical update has occurred regarding a UHR technology / feature.

[0268] Examples 1-2

[0269] In one embodiment of the present disclosure, a standard / format-specific critical update field (CUF) may be set on reserved bit(s) of the capability information field (e.g., the 3rd bit (B2), the 4th bit (B3), the 15th bit (B14) and the 16th bit (B15)) or on reserved bits of the extended capability field of the extended capability element (e.g., the 5th bit (B4) through the 7th bit (B6), the 42nd bit (B41) through the 44th bit (B43) and the 112th bit (B11) or higher). Additionally, the EHT CUF field may be set on the 7th bit (B6) of the capability information field, but is not limited thereto.

[0270] For example, a standard / format-specific CUF may include an EHT CUF, a UHR CUF related to a UHR feature / technology, and a next UHR CUF related to a next UHR feature / technology. The description of the values ​​set in each CUF may be configured as shown in Table 2.

[0271] EHTCUFUHRCUFNext UHR CUF Critical Update Occurred Standard / Format Description 000None (nothing) No critical update occurred 100EHTEHT STA can understand / identify 010 (only) UHRUHR STA can understand / identify 001 (Only) Next UHR Next UHR STA can understand / identify 110 Critical updates have occurred for UHR, EHTUHR features, and EHT features. That is, UHR STA can understand / identify UHR features, and EHT STA can understand / identify EHT features. 101 Next UHR and EHT Critical updates have occurred for next UHR features and EHT features. That is, next UHR STA can understand / identify next UHR features, and EHT STA can understand / identify EHT features. 111 Next UHR, UHR, and EHT Next UHR features, UHR features, and EHT features of A critical update occurred. That is, the next UHR STA can understand / identify the next UHR feature, the UHR STA can understand / identify the UHR feature, and the EHT STA can understand / identify the EHT feature................

[0272] Additionally, Table 2 describes only the following UHR CUFs, but is not limited thereto. That is, the capability information field may include UHR CUFs corresponding to subsequent versions / formats. Additionally, or alternatively, the following UHR CUFs may not exist in a UHR-based wireless LAN system.

[0273] Example 2

[0274] Example 2 relates to a BPCC related to a critical update procedure.

[0275] As described in Example 1, the UCUF or each generation / version / format-specific CUF may be set to a value of 1 in accordance with the change in BPCC. However, as described above, if the BPCC of the underlying multi-link IE or RNR IE used in an EHT-based wireless LAN system is changed based on a critical update to the UHR feature / technology, the EHT STA may not understand the change value of the BPCC.

[0276] Accordingly, Example 2 describes a separate BPCC for a critical update to a feature / technology. In describing the present disclosure, an AP transmitting a modified BPCC may be referred to as a reporting AP, and an AP corresponding to the modified BPCC (e.g., an AP to which a critical update related to the BPCC has been applied) may be referred to as a reported AP. Furthermore, while the following description describes a BPCC related to a critical update to a UHR feature / technology, the following description may also apply to BPCCs related to features / technologies of subsequent versions / generations.

[0277] Example 2-1

[0278] Example 2-1 relates to UHR BPCC in the reported AP.

[0279] FIG. 13 is a diagram illustrating a basic multi-link element according to one embodiment of the present disclosure. As an example of the present disclosure, when a critical update occurs to a reporting AP transmitting a basic multi-link element as illustrated in FIG. 13 (a), a UHR BPCC (sub) field may be included on the common information field of the said basic multi-link element.

[0280] Additionally, a UHR BSS BPCC presence (sub) field may be set / added on the reserved bits (e.g., the 8th bit (B7), the 9th bit (B8), etc.) of the presence bitmap field of the basic multi-link element. The UHR BSS BPCC presence field may indicate whether the UHR BPCC (sub) field exists on the common information field.

[0281] At this time, the size of the UHR BPCC field may be one of 4 bits, 6 bits, or 1 octet (based on the maximum value of the UHR BPCC). However, this is merely one embodiment, and the size of the UHR BPCC field may be determined to various values.

[0282] Additionally or alternatively, the UHR BPCC presence field may have a length of 4 bits or 6 bits, taking into account the maximum value of the UHR BPCC.

[0283] Additionally or alternatively, a UHR BPCC field may be set on a reserved area / bit of the presence bitmap field of the underlying multi-link IE. For example, a UHR BPCC field may be set on 4 / 5 bits of the reserved bits of the presence bitmap field (e.g., the 8th bit (B7) to the 12th bit (B11)). However, this is merely one embodiment, and the size of the UHR BPCC field may be composed of 2 to 3 bits, etc., as described above. The position / order in which the UHR BPCC field is allocated within the reserved bits may be implemented in various ways. As an example of the present disclosure, FIG. 13(b) illustrates a case where a 4-bit UHR BPCC field is allocated on the presence bitmap field of the underlying multi-link element.

[0284] Additionally or alternatively, the reporting AP may include a UHR BPCC field on a Per-STA profile (e.g., a Per-STA profile associated with the reporting AP) of a link information field containing a link ID corresponding to the reporting AP, and the size of the UHR BPCC field may be 4 bits, 6 bits, or 1 octet. And, the link information field may be included in the underlying multi-link IE transmitted by the reporting AP.

[0285] For example, as illustrated in FIG. 14(a), the UHR BPCC field may be included in the STA information field or STA profile associated with the reporting AP. If the UHR BPCC field is included in the STA information field, a field indicating the presence of the UHR BPCC field may be included in the STA control field.

[0286] Additionally or alternatively, the reporting AP may include a UHR BPCC field on a reserved area / bit of the STA control field of the Per-STA profile of the link information field containing the link ID corresponding to the reporting AP. For example, the UHR BPCC field may be set on four bits of the reserved bits of the STA control field (e.g., the 13th bit (B12) to the 16th bit (B15)). However, this is merely one embodiment, and the size of the UHR BPCC field may be composed of 2 to 3 bits, etc., as described above. The position / order in which the UHR BPCC field is allocated within the reserved bits may be implemented in various ways. As an example of the present disclosure, as illustrated in FIG. 14(b), the UHR BPCC field for the reporting AP may be included in the STA control field associated with the reporting AP.

[0287] Additionally or alternatively, depending on the size of the UHR BPCC field, the UHR BPCC field may have a length of 1 octet.

[0288] Example 2-2

[0289] Example 2-2 relates to a UHR BPCC corresponding to the reported AP.

[0290] The reporting AP may include a UHR BPCC field in the TBTT information field corresponding to the reported AP, and the size of the said UHR BPCC field may be 4 bits, 6 bits, or 1 octet (based on the maximum value of the UHR BPCC). However, this is merely one embodiment, and the size of the UHR BPCC field may be determined to various values.

[0291] Additionally or alternatively, the UHR BPCC presence field may have a length of 4 bits and / or 6 bits, taking into account the maximum value of the UHR BPCC field.

[0292] For example, a TBTT information field corresponding to the reported AP may be included in the RNR IE of a management frame (e.g., a beacon frame, etc.) transmitted by the reporting AP.

[0293] FIG. 15 is a diagram illustrating the BPCC field of an RNR IE according to one embodiment of the present disclosure. For example, as shown in FIG. 15 (a) and (b), the RNR IE includes a TBTT information field, and the UHR BPCC field may be included in the TBTT information field or on the UHR parameter field of the TBTT information field. When all fields are included on the TBTT information field of FIG. 15, the length of the TBTT information field may be 18 octets or more.

[0294] Additionally or alternatively, the reporting AP may include a UHR BPCC field on the Per-STA profile of the link information field containing a link ID corresponding to the reported AP, and the size of said UHR BPCC field may be 4 bits, 6 bits, or 1 octet.

[0295] For example, a UHR BPCC field may be set on four bits among the reserved bits of the STA control field (e.g., the 13th bit (B12) to the 16th bit (B15)). However, this is merely one embodiment, and the size of the UHR BPCC field may be composed of 2 to 3 bits, etc., as described above. The position / order in which the UHR BPCC field is allocated within the reserved bits may be implemented in various ways. As an example of the present disclosure, a 4-bit UHR BPCC field may be allocated on the STA control field, as shown in FIG. 14 (a).

[0296] For example, as illustrated in FIG. 14(a), the UHR BPCC field may be included in the STA information field or STA profile associated with the reported AP. If the UHR BPCC field is included in the STA information field, a field indicating the presence of the UHR BPCC field may be included in the STA control field.

[0297] For example, the UHR BPCC field may be included in (re)join response frames, link reset response frames, etc. For example, as shown in FIG. 14(b), the UHR BPCC field may be included in the STA control field of the underlying multi-link IE.

[0298] Additionally or alternatively, depending on the size of the UHR BPCC field, the length of the UHR BPCC field may be 1 octet.

[0299] Additionally or alternatively, the UHRR BPCC field may be configured as a separate IE included within a beacon frame, a probe response frame, or a separately defined action frame. In this case, the IE may be configured within the frame along with an presence bit indicating the presence of the UHR BPCC field. Furthermore, the frame may include a link ID corresponding to the reporting AP and / or the reported AP.

[0300] For example, the initial value of the above-described BPCC field may be 0, and the value of the BPCC field may increase by 1 when a critical update occurs. Additionally, the value of the BPCC field may increase by 1 whenever an IE related to the critical update is added, changed, or updated. For example, if a critical update related to 2 IEs occurs, the value of the BPCC field may increase by 2.

[0301] Example 3

[0302] Example 3 relates to a procedure for updating parameters of a reporting AP and / or a reported AP.

[0303] Specifically, Example 3 relates to a critical update (e.g., an updated parameter) related to the UHR BPCC and UCUF / UHR CUF described in Examples 1 / 2 and a procedure for directing said critical update. In this case, the updated parameter (e.g., a parameter consisting of field(s) corresponding to values ​​directing the operation of the STA(s) supporting the DPS) may be configured in the form of an IE or a field.

[0304] When a critical update occurs, the updated UHR parameter(s) associated with the BPCC change or / and the critical update flag setting may be indicated according to at least one of the embodiments described below (e.g., Examples 3-1 and 3-2). For example, the UHR parameter(s) to be enabled, disabled, or updated (e.g., DPS parameter(s)) may be included in the UHR parameter update element according to the embodiments described below (e.g., Examples 3-1 and 3-2).

[0305] As an example of the present disclosure, the types of DPS (UHR) parameter(s) (e.g., parameter(s) to be enabled, disabled, or updated) are as follows.

[0306] 1) DPS Enabled: The DPS Enabled field may indicate whether the DPS operation of the STA transmitting the DPS parameter containing the field is enabled or disabled.

[0307] In one example of the present disclosure, the DPS Enabled field may have a length of 1 bit. For example, when the transmitting STA enables the DPS operation, the value of the DPS Enabled field may be set to a first value (e.g., '1'). And, when the transmitting STA disables the DPS operation, the value of the field may be set to a second value (e.g., '0').

[0308] 2) Effective time field: The effective time field may indicate the point in time when the above DPS parameter(s) are substantially applied (e.g., the start time of parameter application).

[0309] According to one embodiment, the time at which the DPS parameter(s) are substantially applied may be set based on a timestamp value based on a Timing Synchronization Function (TSF) or the number of Target Beacon Transmission Times (TBTT).

[0310] For example, when a valid time field is set based on the above TSF, a TSF value received from the AP, the entire TSF value of the AP itself (e.g., 8 octets), or / and at least a portion of the above TSF value may be used. Here, a portion of the above TSF value may mean a value corresponding to a range from a specific bit of the above TSF to another specific bit (e.g., a length of 1, 2, 3, 4, 5, 6, 7, or 8 octets).

[0311] Additionally or alternatively, the value of the valid time field may be set based on a specific time unit (e.g., "us"). To this end, information indicating the specific time unit (e.g., 1us, 8us, 32us, 64us, etc.) may be predefined or additionally included within the parameter.

[0312] For example, if the indicated value of the valid time field is '500' and the time unit is indicated as '1us', the application time of the DPS parameter(s) can be interpreted / identified as being after 0.5ms (e.g., 500us) has elapsed from the time when the critical update was received (or, the time when the critical update occurred).

[0313] As another example, if the indicated value of the valid time field is '500' and the time unit is indicated as '8us', the application time can be interpreted / identified as 4ms (500 * 8us) after the time when the critical update was received (or, the time when the critical update occurred).

[0314] 3) DPS padding delay field: The DPS padding delay field (e.g., a field of 1 octet size) may indicate the minimum MAC padding duration required of the DPS STA within the initial control frame (ICF) to switch from a lower capability mode to a higher capability mode.

[0315] 4) DPS transition delay field: The DPS transition delay field (e.g., a field of 1 octet size) may indicate the minimum total time required for the DPS STA to transition from a higher capability mode to a lower capability mode.

[0316] 5) Transition timeout (or DPS transition timeout) field: The transition timeout (or DPS transition timeout) field may indicate a timeout value for returning to or transitioning to a listening state (e.g., low capability state) when an STA that has transitioned to a frame switching state (e.g., high capability state) fails to receive additional PPDU or frames.

[0317] In one example of the present disclosure, if an STA operating in a frame switching state fails to receive an additional PPDU or frame during a timeout period indicated by a switching timeout field, the STA may enter the listening state.

[0318] For example, if an STA that has switched from the listening state to the frame switching state by receiving an ICF fails to receive an additional PPDU or frame during the timeout period, the STA may operate to re-enter the listening state to save power.

[0319] For example, the encoding method of the actual timeout value based on the indicator value of the transition timeout field can be defined as follows. In this case, the applied time unit may follow a predefined rule:

[0320] - If the transition timeout field value is '0': Transition timeout = 0 Tus;

[0321] - If the transition timeout field value is '1': transition timeout = 128 us;

[0322] - If the transition timeout field value is '2': transition timeout = 256 us;

[0323] - If the transition timeout field value is '3': transition timeout = 512 us;

[0324] - If the transition timeout field value is '4': transition timeout = 1 us;

[0325] - If the transition timeout field value is '5': transition timeout = 2 us;

[0326] - If the transition timeout field value is '6': transition timeout = 4 us;

[0327] - If the transition timeout field value is '7': transition timeout = 8 us;

[0328] - If the transition timeout field value is '8': transition timeout = 16 us;

[0329] - If the transition timeout field value is '9': transition timeout = 32 us; and

[0330] - If the transition timeout field value is '10': transition timeout = 64 us.

[0331] 6) ICF Required field: The ICF Required field may indicate whether the transmission of the ICF is required when the DPS operation is initiated. In one example of the present disclosure, if the ICF Required field has a length of 1 bit, the ICF Required field may indicate that the transmission of the ICF is required when the DPS operation is initiated (e.g., set to '1') or that the transmission of the ICF is not required (e.g., set to '0').

[0332] 7) Mode field: The mode field can indicate whether the DPS operation is in default mode or parameterized mode.

[0333] For example, the default mode may be a mode in which the LC mode of DPS operation is operated based on a predefined or fixed value (e.g., bandwidth (e.g., 20 MHz), number of spatial streams (e.g., 1) and / or data transfer rate (e.g., 6, 12, 24 Mbps, etc.)).

[0334] The parameterized mode may be a mode in which the LC mode of DPS operation is operated based on separately specified bandwidth, number of spatial streams (NSS), and modulation and coding scheme (MCS) values.

[0335] For example, if the mode field has a length of 1 bit, the value of the mode field can be set to '1' or '0' to indicate the default mode or the parameterized mode, respectively.

[0336] Additionally or alternatively, fields that individually specify each mode (e.g., default mode or parameterized mode, etc.) may exist independently.

[0337] For example, a default mode field and a parameterized mode field having a length of 1 bit may be configured / set separately. Each field may utilize a value of '1' or '0' to indicate whether the critically updated DPS parameter(s) are for the DPS operation of the default mode or the DPS operation of the parameterized mode.

[0338] In this case, the default mode field and the parameterized mode field may be configured to be mutually exclusive so that they cannot simultaneously have a value (e.g., '1') indicating that each mode is activated. That is, if the value of the default mode field is '1', the value of the parameterized mode field cannot be '1' and can be set to '0'. Additionally, if the value of the parameterized mode field is '1', the value of the default mode field cannot be '1' and can be set to '0'.

[0339] 8) Maximum bandwidth field: The maximum bandwidth field can indicate the maximum bandwidth at which the parameterized mode-based DPS operates.

[0340] The maximum bandwidth field can be defined based on the bandwidths available for operation in a wireless LAN system, and can be defined in a bitmap format representing each bandwidth or defined in a specific index format and mapped to the corresponding maximum bandwidth.

[0341] For example, if the maximum bandwidth field has a length of 2 bits, each indicator value of the field (e.g., 0, 1, 2, 3) can be mapped to correspond to a specific bandwidth (e.g., 20 MHz, 40 MHz, 80 MHz, etc.).

[0342] 9) Max NSS field: The Max NSS field may indicate the maximum number of spatial streams (NSS) in which the parameterized mode-based DPS operates.

[0343] As an example of the present disclosure, the actual applied value of the maximum NSS may be determined by adding '1' to the value indicated in the maximum NSS field.

[0344] For example, if the maximum NSS field has a length of 1 bit, the value of the maximum NSS that can be indicated by the maximum NSS field may be 1 or 2. For another example, if the maximum NSS field has a length of 2 bits, the value of the maximum NSS that can be indicated by the maximum NSS field may be 1, 2, 3, 4 (or up to 5, etc., depending on the embodiment).

[0345] 10) Max MCS field: The Max MCS field can indicate the Max MCS (Modulation and Coding Scheme) in which the parameterized mode-based DPS is operated.

[0346] For example, if the maximum MCS field has a length of 1 bit, the maximum MCS value that can be indicated by the maximum MCS field can be 0 or 1. For another example, if the maximum MCS field has a length of 2 bits, the maximum MCS value that can be indicated by the maximum MCS field can be 0, 1, 2, or 3.

[0347] The following embodiments relate to DPS parameter(s) corresponding to a critical update to a field related to DPS operation (e.g., an event in which the BPCC value changes and / or the critical update flag value is set to a specific value).

[0348] Example 3-1

[0349] Example 3-1 relates to an update of DPS parameter(s) corresponding to a reporting AP and a method for indicating the same. FIG. 16 is a diagram illustrating a method for indicating a parameter update according to one embodiment of the present disclosure. FIG. 16 illustrates the configuration of a parameter update field.

[0350] As an example of the present disclosure, as illustrated in FIG. 16, a UHR action element or a separate IE may include an updated parameter(s) presence bitmap field and / or an updated parameter(s) field. A UHR action element or a separate IE containing the updated parameter(s) presence bitmap field and the updated parameter(s) field may be transmitted or received via a beacon frame, a probe request / response frame, a (re)combination request / response frame, or a separate action frame.

[0351] Additionally or alternatively, an existence bitmap or existence field indicating the presence or absence of field(s) included within the DPS parameter(s) may exist within the parameter update field exemplified in FIG. 16. Additionally or alternatively, unupdated values ​​among the DPS parameter(s) may be set to current / existing values.

[0352] As an example of the present disclosure, as illustrated in FIG. 16, when a mode field within a DPS parameter has a value indicating a default mode, a low capability field following the mode field may be omitted. That is, when the mode field indicates a parameterized mode, the low capability field may necessarily exist.

[0353] As an example of the present disclosure, the inclusion of the low capability field according to the value indicated by the mode field and the operation of the STA accordingly may be configured / defined / instructed as described below.

[0354] - Case where default mode is indicated: When the mode field indicates the default mode, the lower capability field may not be followed. In this case, the STA can perform DPS operations based on the predefined bandwidth, NSS, and data transfer rate for the default mode of the DPS.

[0355] - Case where a critical update occurs from default mode to parameterized mode: When a mode field indicates the default mode and then a critical update occurs to indicate the parameterized mode, a low capability field may be subsequently included. In this case, the STA that previously performed DPS operations based on the default mode can perform DPS operations based on the bandwidth, maximum NSS, and maximum MCS indicated in the low capability field that follows the critical update.

[0356] - Case where an update occurs from parameterized mode to default mode: When the mode field indicates the parameterized mode and a critical update occurs so that it indicates the default mode, the low capability field may not follow. In this case, the STA that previously performed DPS operations based on the values ​​within the low capability field provided according to the parameterized mode may perform DPS operations based on the predefined bandwidth, spatial stream count (SS), and data transfer rate of the default mode of the DPS after the critical update.

[0357] - Case where a critical update of values ​​occurs while maintaining the parameterized mode: The mode field indicates the parameterized mode and continues to indicate the parameterized mode even after the critical update, but the values ​​within the subsequent low capability field may be updated and included with values ​​different from the values ​​within the low capability field indicated in the previous parameterized mode. In this case, the STA that was performing DPS operations based on the bandwidth, max NSS, and max MCS within the previous low capability field may perform DPS operations based on the bandwidth, max NSS, and max MCS within the updated low capability field indicating new values ​​after the critical update.

[0358] Additionally or alternatively, a separate parameter update field presence field may be used to avoid the overhead of necessarily including a presence bitmap every time. Through this, the DPS parameter can be configured to be included within the parameter update field only when a critical update occurs for fields related to DPS operations.

[0359] Additionally or alternatively, the presence bitmap or presence field indicating the presence or absence of specific fields included within the DPS parameter may be included within the parameter update field exemplified in FIG. 17.

[0360] Additionally or alternatively, parameter values ​​that are not newly updated because no critical update occurred can be maintained and applied as the current values ​​previously set in STA.

[0361] As an example of the present disclosure, as illustrated in FIG. 17, when a mode field within a DPS parameter has a value indicating a default mode, a low capability field following the mode field may be omitted. That is, when the mode field indicates a parameterized mode, the low capability field may necessarily exist.

[0362] As an example of the present disclosure, the inclusion of the low capability field according to the value indicated by the mode field and the operation of the STA accordingly may be configured as follows:

[0363] - Case where default mode is indicated: When the mode field indicates the default mode, the lower capability field may not be followed. In this case, the STA can perform DPS operations based on the predefined bandwidth, NSS, and data transfer rate for the default mode of the DPS.

[0364] - Case where a critical update occurs from default mode to parameterized mode: When a mode field indicates the default mode and then a critical update occurs to indicate the parameterized mode, a low capability field may be subsequently included. In this case, the STA that previously performed DPS operations based on the default mode can perform DPS operations based on the bandwidth, maximum NSS, and maximum MCS indicated in the low capability field that follows the critical update.

[0365] - Case where an update occurs from parameterized mode to default mode: When the mode field indicates the parameterized mode and a critical update occurs so that it indicates the default mode, the low capability field may not follow. In this case, the STA that previously performed DPS operations based on the values ​​within the low capability field provided according to the parameterized mode may perform DPS operations based on the predefined bandwidth, spatial stream count (SS), and data transfer rate of the default mode of the DPS after the critical update.

[0366] - Case where a critical update of values ​​occurs while maintaining the parameterized mode: The mode field indicates the parameterized mode and continues to indicate the parameterized mode even after the critical update, but the values ​​within the subsequent low capability field may be updated and included with values ​​different from the values ​​within the low capability field indicated in the previous parameterized mode. In this case, the STA that was performing DPS operations based on the bandwidth, max NSS, and max MCS within the previous low capability field may perform DPS operations based on the bandwidth, max NSS, and max MCS within the updated low capability field indicating new values ​​after the critical update.

[0367] As a trace or alternatively, the parameter update field may be included on the underlying multi-link element. As an example of the parameter update field being included on the underlying multi-link element, at least one of the following options may be applied.

[0368] Option 1: A DPS parameter update present field or an updated DPS parameter presence bitmap may be included in the presence bitmap of the underlying multi-link IE. For example, if the DPS parameter update present field is included in the presence bitmap of the underlying multi-link IE, the DPS parameter update field may be included in the common information field (e.g., the common information field of the underlying multi-link IE). For another example, if the updated DPS parameter presence bitmap is included in the presence bitmap of the underlying multi-link IE, the updated DPS parameter field may be included in the common information field based on the updated DPS parameter presence bitmap.

[0369] Option 2: The DPS parameter update field may be included in the Per-STA profile of the link information field, which includes the link ID corresponding to the reporting AP. For example, as illustrated in FIG. 18(a), the DPS parameter update field may be included in the STA information field or the STA profile field of the underlying multi-link element. For example, if the DPS parameter update field is included in the STA information field of the underlying multi-link element, a field indicating whether the DPS parameter update field exists (e.g., a DPS parameter update presence field) may be included in the STA control field. For another example, if the DPS parameter update field is included in the STA profile field, the STA may check for the existence of the parameter update field by checking for changes in the BPCC and CUF corresponding to the reporting AP.

[0370] Additionally, the updated DPS parameter(s) may exist / be included in the field described above up to time T according to at least one of the conditions described below:

[0371] Condition 1: "T = next DTIM beacon" (The corresponding updated DPS parameter(s) up to the next DTIM beacon of the reporting AP may exist / be included in the fields described above.

[0372] Condition 2: "depending on parameter(s) T" (time may vary depending on the feature-specific parameters for the reported AP. That is, if the time at which the corresponding updated DPS parameter is applied to the updated parameter field of each feature (e.g., based on TBTT, TSF) is set / defined, the corresponding updated DPS parameter(s) may exist / be included in the field described above until that time, even if the next DTIM is passed.

[0373] Additionally or alternatively, if update parameter(s) corresponding to the reporting AP exist (on the underlying multi-link element), an updated parameters included field (e.g., 1 bit) may be included on the common information field of the underlying multi-link element. An STA receiving the underlying multi-link element can identify that updated parameter(s) exist on the underlying multi-link element through the updated parameters included field.

[0374] Example 3-2

[0375] Example 3-2 relates to a DPS update of parameter(s) corresponding to the reported AP and a method for indicating the same.

[0376] As an example of the present disclosure, a parameter update field may be included on a Per-STA profile containing a link ID corresponding to a reported AP included in the underlying multi-link IE.

[0377] For example, as illustrated in FIG. 18(b), the parameter update field may be included in the STA information field or the STA profile field. For example, if the parameter update field is included in the STA information field, a field indicating whether the parameter update field exists (e.g., a parameter update existence field) may be included in the STA control field. For another example, if the parameter update field is included in the STA profile field, the STA may determine the existence of the parameter update field by checking for changes in the BPCC and CUF corresponding to the AP being reported.

[0378] Additionally, if updated parameters corresponding to the reported AP are included / present (in the STA information field or / and STA control field, etc.), the field value of all updated RNR IE corresponding to the reported AP may be set to 1. Additionally or alternatively, separate all updated fields for UHR features may be additionally included / present to distinguish them from EHT features. For example, separate all updated fields for UHR features may be set on the reserved bits (e.g., the 23rd bit (B22), the 24th bit (B23), etc.) of the MLD parameter field of the TBTT information field. Additionally or alternatively, separate all updated fields for UHR features may be indicated / set together with the above-described UHR BPCC fields (e.g., the UHR parameter fields shown in FIG. 15, etc.).

[0379] Additionally, the said updated parameter(s) may exist / be included in the field described above up to time T according to at least one of the conditions described below:

[0380] Condition 1: "T = next DTIM beacon" (The corresponding updated parameter(s) up to the next DTIM beacon of the reporting AP may exist / be included in the fields described above.

[0381] Condition 2: "depending on T" (time may vary depending on the feature-specific parameters for the reported AP. That is, if the time at which the corresponding updated parameter is applied to the updated parameter field of each feature (e.g., based on TBTT, TSF) is set / defined, the corresponding updated parameter(s) may exist / be included in the field described above until that time, even if the next DTIM is passed.

[0382] Additionally or alternatively, it can be used to update broadcast TWT elements included in beacon and / or probe response frames.

[0383] For example, for scheduling AP PUO and / or AP PSM, assume that a set of broadcast TWT parameters is included in the TWT element, with the broadcast TWT ID field value set to 0 and the responder PM mode field value set to 1. In this case, critical updates to the mode / operation for the schedule requiring updates may be available / applied.

[0384] Example 4

[0385] Example 4 relates to condition(s) for performing the UHR critical update procedure described in the examples above.

[0386] In one example of the present disclosure, when an updated parameter(s) are updated based on the conditions described above (e.g., Condition 1 of Example 3-2), said updated parameter(s) may be included in a beacon frame. That is, said parameter(s) may not be included in a beacon frame while the value of said parameter(s) is maintained after the update is completed.

[0387] As another example of the present disclosure, in one example of the present disclosure, when the updated parameter(s) are updated based on the conditions described above (e.g., Condition 2 of Example 3-2), the CUF, BPCC, instructions and / or requirements for the updated parameter(s) may be applied in the same way to the probe response frame and (re)combined response frame.

[0388] Example 5

[0389] Example 5 relates to an example of a UHR critical update procedure.

[0390] FIG. 19 illustrates a critical update-based DPS parameter update procedure according to one embodiment of the present disclosure when AP 1 and AP 2 belong to the same AP MLD.

[0391] Among the subfields of AP 2 shown in FIG. 19, the BPCC subfield may be a field corresponding to AP 1. Additionally, the method of indicating / setting the field(s) may be based on the embodiment(s) described above.

[0392] For example, AP 1 can notify (via B11) that a critical update #1 for EHT (e.g., an update to the EDCA parameter set) has occurred at the time of AP 1's beacon frame 11 (B11). Accordingly, AP 2 can increase the BPCC subfield value of beacon frame 21 (B21) from 3 to 4 and set the CUF subfield value to 1. Additionally, since the EDCA parameter set is an EHT feature rather than a UHR feature, the UCUF value can remain at 0. Furthermore, since information regarding the critical update #1 for EHT is not included in the Per-STA profile, all update-included field values ​​can be set to 0.

[0393] And, AP 2 can be notified (via B12) that an update has occurred for the updated parameter(s) (e.g., DPS parameter(s)) corresponding to the UHR feature at time B12 of AP 1. Accordingly, AP 2 can increase the BPCC subfield value of B22 from 4 to 5 and set the UCUF subfield value to 1. Additionally, since the updated parameter #1 is included in the Per-STA profile corresponding to AP 1, all update-included field values ​​can be set to 1. The value of CUF can remain at 1 until the next DTIM, B24.

[0394] In the example described above, the updated DPS parameter(s) can be signaled by including them in the STA information field of the underlying multi-link element along with the link identifier (Link ID) of AP 1.

[0395] Specifically, during the period when the UCUF field value is set and maintained at 1, the updated DPS parameter information can be included in the beacon frame and broadcast. On the other hand, from the subsequent beacon frame transmitted after the time of transmitting the DTIM beacon frame, the UCUF is reset to 0, and accordingly, the updated parameter information can be excluded from the beacon frame.

[0396] Through the dynamic parameter inclusion operation based on the UCUF described above, the communication node can maintain the size of the beacon frame in a lightweight state. As a result, it is possible to effectively prevent the bloating issue of the beacon frame and the increase in wireless resource overhead that may occur due to the repeated transmission of unnecessary control information.

[0397] After that, if no critical update occurs, the values ​​set up to B22 (e.g., BPCC subfield, CUF subfield, UCUF subfield, subfield containing all updates, etc.) may be retained until the next DTIM beacon, B24.

[0398] In the example described above, the BPCC, CUF, and UCUF field values ​​of AP 2 can be configured as shown in Table 3.

[0399] AP 2 Subfield B20 B21 B22 B23 B24 B25 BPCC3 4 5 5 5 CUF 011110 UCUF 001110 All Updates Included 001110

[0400] Example 6

[0401] Example 6 relates to a signaling method for a UHR critical update procedure. As described above, the STA may be a non-AP STA or an AP.

[0402] As an example of the present disclosure, when a critical update occurs for STA 1 or when a critical update occurs for STA 2, which belongs to the same MLD as STA 1, STA 1 may transmit at least one frame containing at least one of the information described below to another STA via PPDU.

[0403] Here, the frame may be a beacon frame, a probe response frame, a (re)combination response frame, or an action frame. And, the information included in at least one of the frames may include CUF, BPCC, and updated parameter(s).

[0404] Here, the CUF may include a UCUF considering the next generation / standard, and the UCUF may be set to 1 for the critical update (CU) of the UHR feature. For example, the UCUF may be set on the capability information field or on the reserved field / bit of the Extended Capabilities element. Additionally, or alternatively, a CUF for each generation / version / format may be added / defined / set.

[0405] And, the BPCC for STA 1 may be included in the Per-STA profile corresponding to STA 1 of the common information or link information of the underlying ML IE, either for each generation / version / format or integrally. And, the BPCC for STA 2 may be included in the TBTT information field corresponding to the 2nd STA of the RNR IE, either for each generation / version / format or integrally.

[0406] Additionally, updated parameters for STA 1 may be included in the Per-STA profile corresponding to STA 1 in the common information field or link information field. Updated parameters for STA 2 may be included in the Per-STA profile corresponding to STA 2 in the link information field.

[0407] Additionally or alternatively, when the updated parameter(s) are included in the frame, all update-included fields of the RNR IE corresponding to STA 2 may be reused and set to 1, or all update-included field values ​​of UHR may be set to 1.

[0408] Additionally or alternatively, the updated parameters may be included / retained until the next DTIM beacon of STA 1 or at a point in time based on the updated parameters.

[0409] Additionally, the updated parameter(s) may be included in the frame when updated based on at least one of the conditions described above. That is, the updated parameter(s) may not be included in the frame while the update is complete and the value of the parameter(s) is maintained.

[0410] For example, STA 2, which receives a frame containing critical update information from STA 1, can perform frame detection. Through frame detection for the frame, STA 2 can obtain parameter(s) related to the critical update.

[0411] By various embodiments of the present disclosure, the overall management efficiency of a wireless communication system can be improved by transmitting and receiving DPS parameters that are essential for the DPS operation of a STA through an enhanced critical update mechanism.

[0412] In particular, by signaling the enable, disable, or updated DPS parameter(s) based on an enhanced critical update mechanism, the STA performing the DPS operation can preemptively obtain the updated DPS parameter(s) before the application and update of the said DPS parameter(s) occur.

[0413] This prevents performance degradation and malfunctions that may occur when the STA omits update information such as control frames, and as a result, ensures perfect consistency and synchronization of DPS operations between the AP and the STA, thereby providing reliable power-saving communication.

[0414] FIG. 20 is a diagram illustrating a PPDU transmission and reception procedure between a transmitting STA and a receiving STA according to one embodiment of the present disclosure. Some of the step(s) shown in FIG. 20 may be omitted depending on the situation and / or settings, etc. The transmitting device and the receiving STA may be an AP and / or a non-AP STA.

[0415] The transmitting STA can obtain control information related to the tone-plan (or RU / DRU) described above (S105). The control information related to the tone-plan may include the size and location of the RU, control information related to the RU, information regarding the frequency band in which the RU is included, information regarding the STA receiving the RU, etc.

[0416] The transmitting STA can configure / generate a PPDU based on acquired control information (S110). Configuring / generating a PPDU may mean configuring / generating each field of the PPDU. That is, the step of configuring / generating a PPDU may include the step of configuring the U-SIG and UHR-SIG-A / B / C fields containing control information regarding the tone-plan.

[0417] That is, the step of configuring / generating the PPDU may include the step of configuring a field containing control information (e.g., N bitmap) indicating the size / location of the RU and / or the step of configuring a field containing an identifier (e.g., AID) of the STA receiving the RU.

[0418] Additionally, the step of configuring / generating the PPDU may include the step of generating an STF / LTF sequence transmitted through a specific RU. The STF / LTF sequence may be generated based on a preset STF generation sequence / LTF generation sequence.

[0419] Additionally, the step of configuring / generating the PPDU may include the step of generating a data field (i.e., MPDU) that is transmitted through a specific RU.

[0420] The transmitting STA can transmit the configured / generated PPDU to the receiving STA (S115).

[0421] Specifically, the transmitting STA can perform at least one of cyclic shift diversity (CSD), spatial mapping, inverse discrete Fourier transform (IDFT) / inverse fast Fourier transform (IFFT) operations, and guard interval (GI) insertion operations.

[0422] The receiving STA can decode the PPDU and obtain control information related to the tone-plan (or RU) (S120).

[0423] Specifically, the receiving STA can decode the L-SIG and U-SIG / UHR-SIG of the PPDU based on L-STF / LTF and obtain information contained in the L-SIG, U-SIG, and UHR-SIG fields. Information regarding various tone-plans (i.e., RU) of the present disclosure may be contained in U-SIG / UHR-SIG (UHR-SIG-A / B / C, etc.), and the receiving STA can obtain information regarding tone-plans (i.e., RU) through EHT-SIG.

[0424] The receiving STA can decode the remainder of the PPDU based on information regarding the acquired tone-plan (i.e., RU) (S125). For example, the receiving STA can decode the STF / LTF field of the PPDU based on information regarding the tone-plan (i.e., RU). Additionally, the receiving STA can decode the data field of the PPDU based on information regarding the tone-plan (i.e., RU) and acquire the MPDU contained in the data field.

[0425] In addition, the receiving STA can perform a processing operation to transmit the decoded data to an upper layer (e.g., MAC layer). In addition, if the generation of a signal is instructed from the upper layer to the PHY layer in response to the data transmitted to the upper layer, the receiving STA can perform a subsequent operation.

[0426] The signaling method described above may be valid only in situations where the DRU is applied and in specific bandwidth and distributed bandwidth situations described in each embodiment. In other situations, the field / information corresponding to the signaling described above may be reserved or used for other purposes or for its original purpose. Accordingly, efficient DRU-based PPDU transmission and reception can be performed, and coverage and output volume can be improved.

[0427] The embodiments described above are combinations of the components and features of the present disclosure in a specific form. Each component or feature should be considered optional unless otherwise explicitly stated. Each component or feature may be implemented in a form not combined with other components or features. Additionally, it is possible to construct 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 obvious that embodiments may be constructed by combining claims that are not explicitly related in the claims, or that they may be included as new claims by amendment after filing.

[0428] It is obvious to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential features of the present disclosure. Accordingly, the detailed description set forth above should not be interpreted restrictively in all respects and should be considered exemplary. The scope of the present disclosure shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present disclosure are included within the scope of the present disclosure.

[0429] The scope of the present disclosure includes software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that enable operations according to the methods of various embodiments to be executed on a device or computer, and a non-transitory computer-readable medium on which such software or instructions, etc. are stored and executable on a device or computer. Instructions that may be used to program a processing system to perform the features described in the present disclosure may be stored on or within a storage medium or a computer-readable storage medium, and the features described in the present disclosure may be implemented using a computer program product comprising such a storage medium. The storage medium may 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 may 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 may optionally include one or more storage devices located remotely from the processor(s). Memory or alternatively, non-volatile memory device(s) within memory comprises a non-transient computer-readable storage medium. The features described in this disclosure may be stored in any one of the machine-readable media and integrated into software and / or firmware that can control the hardware of a processing system and allow the processing system to interact with other mechanisms utilizing results according to the embodiments of this disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0430] Although the method proposed in this disclosure has been described with an example applied to an IEEE 802.11-based system, it can be applied to various wireless LANs or wireless communication systems in addition to IEEE 802.11-based systems.

Claims

1. A step of generating a first frame by a first access point (AP) that includes an ultra-high reliability (UHR) parameter update element; and The method includes the step of transmitting the first frame by the first AP, The first frame above includes an enhanced critical updates flag field set to 1 and an enhanced all updates included field related to the UHR parameter update element, and A method wherein the above UHR parameter update element comprises at least one field related to enabling, disabling, or updating at least one parameter for dynamic power save (DPS).

2. In Paragraph 1, A method wherein at least one parameter comprises at least one of: a minimum padding interval required to switch from a low capability (LC) mode to a high capability (HC) mode; an amount of time required to switch from the HC mode to the LC mode; first information regarding whether transmission of an initial control frame (ICF) is required before performing a DPS operation; second information regarding a mode related to a DPS operation; a maximum bandwidth supported for a DPS operation; a maximum number of spatial streams supported for a DPS operation; or a maximum modulation and coding scheme (MCS) supported for a DPS operation.

3. In Paragraph 2, A method wherein at least one field comprises at least one of the following: a DPS padding delay field in which the minimum padding interval is set, a DPS switching delay field in which the amount of time is set, a first field in which the first information is set, a second field in which the second information is set, a third field in which the maximum bandwidth is set, a fourth field in which the number of the maximum spatial streams is set, or a fifth field in which the maximum MCS value is set.

4. In Paragraph 1, The above improved critical update flag field is included in the capability information field of the first frame, a method.

5. In Paragraph 1, The above first AP is a method of being affiliated with an AP multi-link device (MLD).

6. In Paragraph 4, The above first frame includes an improved basic service set (BSS) parameter change count field and a critical update type field, and A method in which the field containing all of the above-mentioned improved updates is included in the improved critical update information field of the first frame.

7. In Paragraph 6, A method in which, based on the fact that the improved BSS parameter change count field and the critical update type field are related to the first AP, the improved critical update information field is included in the common information field of the basic multi-link element of the first frame.

8. In Paragraph 7, A method in which the above-mentioned improved critical update information present field is included in the above-mentioned presence bitmap subfield of the above-mentioned basic multi-link element.

9. In Paragraph 6, A method in which, based on the fact that the improved BSS parameter change count field and the critical update type field are related to the second AP, the improved critical update information field is included in the TBTT information field of the reduced neighbor report (RNR) element of the first frame.

10. In Paragraph 6, A method in which the above UHR parameter update element includes a timer field related to the number of TBTTs up to a specific TBTT in which the update indicated in the above UHR parameter update element takes effect on the first AP or the second AP.

11. In Paragraph 1, A method in which the above UHR parameter update element is included on a Per-STA profile corresponding to the first AP or the second AP.

12. In Paragraph 6, A method in which the values ​​set in each of the above-mentioned improved BSS parameter change count field, the above-mentioned critical update type field, and the above-mentioned field including all improved updates are maintained until the next Delivery Traffic Indication Map (DTIM) beacon.

13. In Paragraph 9, The above-mentioned second AP belongs to the AP MLD to which the above-mentioned first AP belongs, and A method in which the first STA is a non-AP STA associated with the first AP.

14. In Paragraph 1, A method in which the first frame comprises at least one of a beacon frame, a probe response frame, or an association response frame.

15. In the first access point, the first AP is: One or more transceivers; and It includes one or more processors connected to the above one or more transmitters and receivers, and The above one or more processors are: Generate a first frame including an UHR (ultra-high reliability) parameter update element; and The above first frame is transmitted through the above one or more transceivers, and The first frame above includes an enhanced critical updates flag field set to 1 and an enhanced all updates included field related to the UHR parameter update element, and The above UHR parameter update element is a first STA comprising at least one field related to enabling, disabling, or updating at least one parameter for dynamic power save (DPS).

16. A step of receiving a first frame containing an ultra-high reliability (UHR) parameter update element from a first access point (AP) by a first station (STA); and The step of decoding the first beacon frame by the first STA is included, The first frame above includes an enhanced critical updates flag field set to 1 and an enhanced all updates included field related to the UHR parameter update element, and A method wherein the above UHR parameter update element comprises at least one field related to enabling, disabling, or updating at least one parameter for dynamic power save (DPS).

17. In the first station (STA), the first STA is: One or more transceivers; and It includes one or more processors connected to the above one or more transmitters and receivers, and The above one or more processors are: Receiving a first frame containing an UHR (ultra-high reliability) parameter update element from a first access point (AP) through one or more transceivers; and It is set to decode the above first frame, and The first frame above includes an enhanced critical updates flag field set to 1 and an enhanced all updates included field related to the UHR parameter update element, and The above UHR parameter update element is a first STA comprising at least one field related to enabling, disabling, or updating at least one parameter for dynamic power save (DPS).

18. A processing device configured to control a first station (STA) in a wireless local area network (WLAN) system, wherein the processing device: One or more processors; and A processing device comprising one or more computer memories that are operably connected to one or more processors and store instructions for performing a method according to any one of claims 1 to 14 based on execution by one or more processors.

19. One or more non-transitory computer-readable media storing one or more instructions, A computer-readable medium in which one or more of the above commands are executed by one or more processors to control a device in a wireless LAN system to perform a method according to any one of claims 1 to 14.

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