Method and device for initiating beam-related procedure for announcement-based millimeter-wave band in sub-7 ghz band of multi-link device in wireless LAN system

Abstract

Disclosed are a method and a device for initiating a beam-related procedure for an announcement-based millimeter-wave band in a sub-7 GHz band of a multi-link device in a wireless LAN system. A method according to an aspect of the present disclosure may comprise: generating, by a first station (STA) affiliated with a first multi-link device (MLD), an announcement frame including information on a beam-related procedure; and transmitting, by the first STA, on a first link, the announcement frame to a second STA affiliated with a second MLD. On the basis of the information on the beam-related procedure, the beam-related procedure may be performed on a second link by a third STA affiliated with the first MLD and a fourth STA affiliated with the second MLD.

Description

Method and apparatus for initiating a beam-related procedure in a known-based millimeter wave band in the sub-7GHz band of a multi-link device in a wireless LAN system

[0001] The present disclosure relates to a method and apparatus for initiating a beam-related procedure in a known-based millimeter wave band in the sub-7 GHz band of a multi-link device 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 disclosing a known-based millimeter-wave band beam-related procedure in the sub-7 GHz band of a multi-link device (MLD).

[0005] 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.

[0006] A method according to one aspect of the present disclosure may include: generating an announcement frame containing information about a beam-related procedure by a first station (STA) affiliated with a first multi-link device (MLD); and transmitting the announcement frame to a second STA affiliated with a second MLD on a first link by the first STA. Based on the information about the beam-related procedure, a beam-related procedure may be performed on a second link by a third STA affiliated with the first MLD and a fourth STA affiliated with the second MLD.

[0007] A method according to a further aspect of the present disclosure may include: receiving an announcement frame containing information about a beam-related procedure at a first link from a first STA affiliated with a first MLD, by a second station (STA) affiliated with a second multi-link device (MLD); and processing the information about the beam-related procedure included in the announcement frame by the second STA. Based on the information about the beam-related procedure, a beam-related procedure at a second link may be performed by a third STA affiliated with the first MLD and a fourth STA affiliated with the second MLD.

[0008] According to the present disclosure, a method and apparatus may be provided for initiating a known-based millimeter wave band beam-related procedure in the sub-7 GHz band of a multi-link device in a wireless LAN system.

[0009] 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.

[0010] 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.

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

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

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

[0014] FIG. 4 is a drawing illustrating a backoff process to which the present disclosure may be applied.

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

[0016] 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.

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

[0018] FIG. 8 illustrates, exemplarily, the structure of an ML element to which the present disclosure can be applied.

[0019] FIG. 9 is a drawing for illustrating an example of a high-level structure for an AP MLD to which the present disclosure can be applied.

[0020] FIG. 10 illustrates a sector level sweep (SLS) step that can be applied to the present disclosure.

[0021] FIG. 11 illustrates two types of sector sweeps that can be applied to the present disclosure.

[0022] FIG. 12 illustrates a BRP transaction that can be applied to the present disclosure.

[0023] FIG. 13 shows an exemplary format of an NDP notice frame to which the present disclosure may be applied.

[0024] FIG. 14 illustrates an AP MLD and a non-AP MLD that support the mmWave band and can be applied to the present disclosure.

[0025] FIG. 15 illustrates the discovery and multi-link setup process for multi-link operation in a wireless communication system applicable to the present disclosure.

[0026] FIG. 16 is a drawing for explaining an example of the operation of a first STA according to the present disclosure.

[0027] FIG. 17 is a drawing for explaining an example of the operation of a second STA according to the present disclosure.

[0028] FIG. 18 illustrates an example of disclosing a BFT through a known frame containing information about the BFT according to the present disclosure.

[0029] FIG. 19 shows examples of BFT intervals according to the present disclosure.

[0030] FIG. 20 shows an example of a respondent list and respondent schedule information according to the present disclosure.

[0031] FIG. 21 shows an example of a BFT interval indication using a time gap according to the present disclosure.

[0032] FIG. 22 shows an STA information field format including BFT common information according to the present disclosure.

[0033] FIG. 23 shows examples of frame formats containing BFT common information that can be applied to the present disclosure.

[0034] FIG. 24 shows examples of STA information field formats containing user-party information using ambiguity-resolving subfields according to the present disclosure.

[0035] FIG. 25 shows examples of STA information field formats containing user-per-user information using the Nc subfield according to the present disclosure.

[0036] FIG. 26 shows examples of frame formats containing BFT user-per-user information according to the present disclosure.

[0037] FIGS. 27 through 29 show examples of known-based BFT signaling for initiating BFT according to the present disclosure.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] The following describes the technical features to which the examples of the present disclosure may be applied.

[0045] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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).

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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, in the following example, 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 of transmission and reception signals can be stored in the memory (104, 204) of FIG. 1.

[0057] 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.

[0058] FIG. 2 is a drawing showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0059] 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.

[0060] 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.

[0061] 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).

[0062] 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.

[0063] 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.

[0064] 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).

[0065] 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.

[0066] 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.

[0067] In addition to the structure of the aforementioned DS, an Extended Service Set (ESS) may be configured to provide wider coverage.

[0068] 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.

[0069] 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.

[0070] FIG. 3 is a diagram illustrating a link setup process to which the present disclosure can be applied.

[0071] 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.

[0072] 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.

[0073] 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).

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] FIG. 4 is a drawing illustrating a backoff process to which the present disclosure may be applied.

[0084] 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.

[0085] 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).

[0086] 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, ...).

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] FIG. 5 is a diagram illustrating a CSMA / CA-based frame transmission operation to which the present disclosure may be applied.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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).

[0109] FIG. 7 is a drawing illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure may be applied.

[0110] 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)).

[0111] 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).

[0112] 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)).

[0113] 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 the 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.).

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.).

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] Multi-link operation (MLO)

[0140] The following describes the multi-link (ML) operations supported by the STA according to the present disclosure.

[0141] 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.

[0142] When a single STA supports multiple links, the transceiver supporting each link may operate as a single logical STA. Specifically, 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.

[0143] 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.

[0144] 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 on multiple links supported by the MLD are possible, or non-simultaneous transmit and receive (NSTR) operations are not possible; 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.

[0145] 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.

[0146] 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, a TID is mapped to all setup links, so all setup links can be enabled.

[0147] 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.

[0148] If a link is disabled, it may not be used for frame exchange, including management frames for both DL and UL.

[0149] 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.

[0150] 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.

[0151] FIG. 8 illustrates, exemplarily, the structure of an ML element to which the present disclosure can be applied.

[0152] 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).

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] 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).

[0158] FIG. 9 is a drawing for illustrating an example of a high-level structure for an AP MLD to which the present disclosure can be applied.

[0159] An AP MLD may include one or more APs. A single AP MLD may have a high-level architecture such as that shown in FIG. 9. For example, the MLD may use an upper MAC sublayer to control various procedures / parameters that are common to multiple APs. For example, authentication, association, sequence number (SN) / packet number (PN) assignment, and power-saving buffering for individually addressed frames may be commonly controlled among APs belonging to a single AP MLD.

[0160] Each affiliated AP (e.g., AP 1, ..., AP n) can provide upper MAC sublayer functions for non-MLD data frames (e.g., traffic transmitted to and received with non-MLD STAs, group-addressed MLD traffic, etc.). AP MLD can provide upper MAC sublayer functions for MLD data frames (e.g., traffic transmitted to and received with MLD STAs) and can provide MLD data to the lower MAC sublayer of each affiliated AP. Each affiliated AP can provide PHY functions (e.g., PHY 1, ..., PHY n). Both ML operations (MLO) and non-MLO can be performed on links corresponding to each PHY (e.g., Link 1, ..., Link n).

[0161] Beamforming training

[0162] Beamforming training can determine appropriate receiving and transmitting antenna sectors for paired STAs. This can be achieved through the transmission of a bidirectional training frame sequence.

[0163] The beamforming phase is divided into two sub-phases. First, the initial coarse-grain antenna sector configuration can be determined during the sector level sweep (SLS). This information is used in the subsequent optional beam refinement phase (BRP), where fine-tuning of the selected sector can be performed.

[0164] First, the operation in the SLS phase is explained.

[0165] During SLS, the two STAs can each train either the transmitting antenna sector or the receiving antenna sector.

[0166] During SLS, a pair of stations can find the sector providing the highest signal quality by exchanging a series of sector sweep (SSW) frames (or beacons in the case of transmission sector training in PCP / AP) across multiple antenna sectors. For example, during SLS, each station can operate once as a transmitter and once as a receiver of the sweep, as shown in Fig. 10.

[0167] FIG. 10 illustrates a sector level sweep (SLS) step that can be applied to the present disclosure.

[0168] Referring to FIG. 10, the STA that performs the transmission first corresponds to the initiator, and the other STA in the pair may correspond to the responder.

[0169] The initiator's sweep and the responder's sweep can be utilized in two different ways, as shown in Fig. 11.

[0170] FIG. 11 illustrates two types of sector sweeps that can be applied to the present disclosure.

[0171] Referring to FIG. 11, FIG. 11 (a) represents a transmit sector sweep (TXSS), and FIG. 11 (b) represents a receive sector sweep (RXSS).

[0172] During a transmit sector sweep (TXSS), frames are transmitted from different sectors, while the pairing node can receive them in a quasi-omni-directional pattern. To identify the strongest transmission sector, the transmitter can mark identifiers for the antenna and sector used for all frames.

[0173] Additionally, during a receive sector sweep (RXSS), transmissions within the same sector (the best-known sector) can test the optimal receive sector at the pairing node. Overall, the following four types of sweep combinations for SLS are possible.

[0174] - Send sector sweep (TXSS) in both initiator and responder

[0175] Receive Sector Sweep (RXSS) on both STAs

[0176] - Initiator RXSS and Respondent TXSS

[0177] - Initiator TXSS and responder RXSS

[0178] For the achieved optimal SNR and TXSS, sector and antenna identifiers can be reported to the pairing node, and such SLS feedback can follow the structure shown in FIG. 7.

[0179] Feedback to the initiator is conveyed via every frame of the responder sector sweep, which can guarantee reception under an optimal antenna configuration that is not yet known. Feedback to the responder can be transmitted as a single SSW feedback PPDU / frame at the determined optimal antenna configuration. Finally, the SSW feedback PPDU / frame can be acknowledged by the responder with an SSW-ACK. The final PPDU / frame can be additionally used to negotiate the details of the subsequent BRP.

[0180] If the two STAs have sufficient transmit antenna gain, their SLS phase can be realized as pure transmit sector training, and receive sector training can be deferred to a subsequent BRP. Additionally, the initiator can instruct / request the responder to perform a receive sector sweep by specifying the number of receive sectors to be trained during their sweep, i.e., the initiator's sweep. If the initiator sweep corresponds to receive sector training, an additional signal may be required prior to the SLS phase.

[0181] Next, the operation in BRP is explained.

[0182] BRP can refine sectors found in the SLS stage. These sectors are determined using a non-uniform quasi-omni-directional antenna pattern and may have suboptimal signal quality. Additionally, BRP can predict the optimization of antenna weight vectors regardless of pre-defined sector patterns for phased antenna arrays.

[0183] This allows for increasing the beam training search space while simultaneously obtaining additional throughput gains. Although free variation of the antenna weight vector can result in arbitrary antenna patterns, directional characteristics can be preserved for antenna configurations that provide high throughput. Therefore, the training process for optimizing pre-defined directional sectors and antenna weight vectors can remain the same. Finally, if BRP is not part of the previous SLS, BRP can be used to train the receiver antenna configuration.

[0184] A BRP transaction can evaluate a set of directional transmission or reception patterns against the directional configuration known to be the best at the pairing node. Thus, the imperfections of quasi-omnidirectional patterns can be prevented. Since BRP relies on the preceding SLS step, reliable PPDU / frame exchange is guaranteed, and various antenna configurations can be tested across the same PPDU / frame. This can significantly reduce transmission overhead, unlike SLS, which requires the entire PPDU / frame to test a sector. In this regard, to sweep antenna configurations across the entire PPDU / frame, transmit and receive training fields (TRN-T / R) can be added to the PPDU / frame exchanged during the BRP transaction. Each field can be transmitted or received with the antenna configuration to test signal quality. The remainder of the PPDU / frame can be transmitted and received with the antenna configuration known to be the best.

[0185] BRP receive antenna training can be requested by specifying the number of configurations to test in the L-RX header field of the PPDU / frame. The pairing node may add that number of TRN-R fields to the next PPDU / frame. Transmit training can be requested by setting the TX-TRN-REQ header field and adding the TRN-T field to the same BRP PPDU / frame. Optionally, an acknowledgment PPDU / frame with the TX-TRN-OK field set and no training fields added may be transmitted by the receiver before the requester adds the TRN-T field to the next PPDU / frame. As with SLS, BRP feedback may be provided in the form of the SNR for the best found configuration and, in the case of transmit training, the best configuration ID.

[0186] FIG. 12 illustrates a BRP transaction that can be applied to the present disclosure.

[0187] Referring to Fig. 12, the BRP transaction can be configured to first train the receiving configuration between two STAs and then perform additional sending training refinement.

[0188] For example, STA B can combine transmit and receive training requests into a single PPDU / frame using the aforementioned request variation. On the other hand, STA A can request two transmit directions using two PPDU / frames.

[0189] The BRP phase may follow immediately after SLS using an SSW ACK frame for parameter exchange. Alternatively, the BRP phase may be initiated based on a special BRP setup sub-phase consisting of a BRP frame without a training field. In either case, the L-RX and TX-TRN-REQ fields may be used to exchange BRP parameters.

[0190] NDP Announcement Frame

[0191] In wireless LAN systems, sounding procedures / protocols are used to determine channel state information. A beamformer STA requesting channel state information can transmit a training signal to beamformee STA(s). The beamformee STA can measure the channel using the training signal (e.g., sounding NDP) and feed back an estimate of the channel state to the beamformer STA. The beamformer STA can derive a steering matrix or a beamforming matrix using the feedback estimate.

[0192] The beamforming STA can feed back estimates of the channel state to the beamformer STA through a compressed beamforming / CQI (channel quality indication) report frame. The information fed back may include single-user (SU) feedback, multi-user (MU) feedback, CQI feedback, etc.

[0193] The beamformer STA can transmit an NDP announcement and NDP to the beamformer(s) and receive feedback information from the beamformer STA(s). Additionally or alternatively, the beamformer STA can transmit an NDP announcement and NDP to the beamformer(s) and transmit a beamforming report poll (BFRP) or BFRP trigger to the beamformer(s) to receive feedback information from the beamformer(s).

[0194] NDP Notice (NDPA) frames can have multiple types or variants. For example, NDP Notice frames can be composed of various formats, such as VHT NDP Notice frames, HE NDP Notice frames, and EHT NDP Notice frames. These formats can be distinguished by the NDP Notice variant subfield within the sounding dialog token field.

[0195] FIG. 13 shows an exemplary format of an NDP notice frame to which the present disclosure may be applied.

[0196] An NDP notice frame may include one or more STA information (Info) fields. If an NDP notice frame includes only one STA Info field, the RA (receiver address) field may be set to the address of an STA capable of providing feedback. If an NDP notice frame includes multiple STA Info fields, the RA field may be set to a broadcast address.

[0197] The TA (transmitter address) field may be set to the address of the STA transmitting the NDP notice frame or to the bandwidth signaling TA of the STA transmitting the NDP notice frame. For example, in a non-HT or non-HT duplicate format, if the scrambling sequence (or scrambling sequence and service field) includes parameters for channel bandwidth, the TA field may be set to the bandwidth signaling TA.

[0198] The first two bits (B0 and B1) of the eight bits (B0-B7) of the sounding dialogue token field can be used to indicate the type / variant of the NDP notice frame. For example, for VHT or HE, B0 has a value of 0, and if the value of B1 is 0, it may indicate a VHT NDP notice frame, and if the value of B1 is 1, it may indicate an HE NDP notice frame. For example, an EHT NDP notice frame may correspond when both the values ​​of B0 and B1 are set to 1. If the value of B0 is 1 and the value of B1 is 0, it may correspond to a ranging NDP notice frame.

[0199] In the case of VHT STA, the first two bits (B0 and B1) of the sounding dialogue token field are defined as reserved, so VHT STA can recognize the sounding dialogue token number field of bits B2-B7 regardless of the values ​​of B0 and B1.

[0200] For VHT STA, the first two bits (B0 and B1) of the sounding dialogue token field are defined as reserved. Therefore, VHT STA can recognize the sounding dialogue token number field of bits B2-B7 regardless of the values ​​of B0 and B1.

[0201] For HE STA, the first bit (B0) of the sounding dialogue token field is defined as reserved, and the value of the second bit (B1) is defined as indicating a VHT NDP notice frame if the value of B1 is 0 and indicating an HE NDP notice frame if the value of B1 is 1. Therefore, HE STA can recognize the sounding dialogue token number field of bits B2-B7 when the value of B1 is 1, regardless of the value of B0.

[0202] The sounding dialogue token number subfield (bit positions B2-B7) may include a value for identifying an NDP notification frame selected by the beamformer.

[0203] An NDP notification frame may contain n (where n is an integer greater than or equal to 1) STA Info fields. Each STA Info field has a size of K octets, and K=2 in a VHT NDP notification frame, and K=4 in a HE NDP notification frame or an EHT NDP notification frame.

[0204] As shown in the example of FIG. 13(a), the STA Info field of the VHT NDP notification frame may include AID12, feedback type, and Nc index subfields.

[0205] The AID12 subfield contains 12 LSB (least significant bits) of the AID of the STA expected to process the subsequent NDP and prepare sounding feedback.

[0206] The feedback type subfield indicates the type of feedback required, and corresponds to SU if the value is 0 and MU if the value is 1.

[0207] The Nc index subfield indicates the value obtained by subtracting 1 from the number of columns (i.e., Nc) in the compressed beamforming feedback matrix (i.e., Nc-1) when the feedback type is MU. When it is SU, the Nc index field is reserved.

[0208] The example in FIG. 13(b) shows the format of the STA Info field of the HE NDP notification frame when the value of the AID11 field is not a specific value (e.g., 2047).

[0209] Values ​​of the AID11 subfield other than a specific value (e.g., 2047) include 11 LSB among the AIDs of the STA expected to process the subsequent NDP and prepare sounding feedback.

[0210] The partial BW Info subfield may include a 7-bit (B0-B6) RU start index and a 7-bit (B7-B13) RU end index. The RU index may be determined based on the bandwidth of the NDP notice frame, and the unit may be 26-tone RU. For example, to indicate a 26-tone RU index X, the value of the start / end RU index subfield may be set to X-1.

[0211] The feedback type and Ng subfield, in combination with the codebook size subfield, can indicate whether SU / MU / CQI feedback is requested for trigger-based (TB) sounding, Ng=4 or 16, and the quantization resolution. For non-TB sounding, the feedback type and Ng subfield and the codebook size subfield can indicate SU or CQI.

[0212] The disambiguation subfield is set to 1 to help prevent non-HE STAs (e.g., VHT STAs) from misinterpreting the field as an AID field.

[0213] The Nc subfield is set to a value of Nc-1. If the feedback type is SU or MU, Nc corresponds to the number of columns in the compressed beamforming feedback matrix, and if the feedback type is CQI, Nc may correspond to the number of space-time streams (STS). For NDP notice frames that have an AID11 subfield value other than 2047 and are individually addressed for a single STA, the Nc subfield may be reserved.

[0214] The example in FIG. 13(c) shows the format of the STA Info field of the HE NDP notification frame when the value of the AID11 field is a specific value (e.g., 2047).

[0215] The disallowed subchannel bitmap subfield indicates the 20 MHz subchannel(s) and 242-tone RU(s) present in the sounding NDPs announced by the NDP announcement frame, and the 242-tone RU(s) to be included in the requested sounding feedback. The lowest numbered bit of the disallowed subchannel bitmap corresponds to the 20 MHz subchannel located at the lowest frequency among all 20 MHz subchannels within the BSS bandwidth. Each subsequent bit in the bitmap corresponds to the next highest 20 MHz subchannel. A bit set to 1 in the bitmap may indicate that no energy is present in the sounding NDP associated with the NDP announcement frame. For each disallowed 20 MHz subchannel, the 242-tone RU that is closest in frequency to the corresponding 20 Hz subchannel may be disallowed for a PPDU using a specific tone plan. The STA(s) addressed by the NDP notice frame do not include tones from the 242-tone RU that are not allowed when determining the average SNR of STS 1 through Nc in generating the requested sounding feedback. If a 20 MHz subchannel and its corresponding 242-tone RU are allowed, the corresponding bit in the bitmap is set to 0.

[0216] An example of FIG. 13(d) shows the format of the STA Info field of the EHT NDP notification frame.

[0217] AID11 subfields can be defined as shown in Table 1. By default, AID11 subfields contain the identifier of the STA expected to process the subsequent NDP and prepare sounding feedback.

[0218] Description of AID Subfield Value NDP Notice Frame Type / Variant Applicability 0- Addressed for a combined AP, mesh AP, or IBSS STA where the STA Info field is located. Applicable to all variants 1- 2007- If the NDP notice frame is not a ranging variant, the STA Info field is addressed for a combined STA having the same AID as the value of the AID11 subfield. - If the NDP notice frame is a ranging variant, the STA Info field is addressed for an uncombined STA or combined STA having the same RSID / AID as the value of the RSID11 / AID11 subfield. - For EHT variants, the 2007 value is reserved. Applicable to all variants 2008- 2042 Reserved. Not applicable to all variants 2043- If the NDP notice frame is a ranging variant, the STA Info field is sequence Includes authentication code. - Otherwise, the AID11 value is reserved. Applicable only to the ranging variant. 2044 - If the NDP announcement frame is a ranging variant, the STA Info field includes a partial TSF (timing synchronization function). - Otherwise, the AID11 value is reserved. Applicable only to the ranging variant. 2045 - If the NDP announcement frame is a ranging variant, the STA Info field includes ranging measurement parameters. - Otherwise, the AID11 value is reserved. Applicable only to the ranging variant. 2046 Reserved. Not applicable to all variants. 2047 - If the NDP announcement frame is an HE variant, the STA Info field includes an unauthorized subchannel bitmap. - Otherwise, the AID11 value is reserved. Applicable only to the HE variant.

[0219] The partial BW subfield may include a 1-bit (B0) resolution subfield and an 8-bit (B1-B8) feedback bitmap. The resolution subfield indicates a resolution bandwidth (e.g., 20 MHz or 40 MHz) for each bit of the feedback bitmap subfield. The feedback bitmap subfield may indicate requests for each resolution bandwidth from low frequency to high frequency, and the first bit (B1) of the bitmap corresponds to the lowest resolution bandwidth. Each bit of the feedback bitmap is set to 1 when feedback for the corresponding resolution bandwidth is requested.

[0220] If the bandwidth of the EHT NDP notification frame is less than 320 MHz, the value of the resolution bit (B0) can be set to 0 to indicate a resolution of 20 MHz.

[0221] If the bandwidth of the EHT NDP notification frame is 20 MHz, B1 is set to 1 to indicate that feedback for 242-tone RU is requested, and B2-B8 can be reserved and set to 0.

[0222] When the bandwidth of the EHT NDP notice frame is 40 MHz, B1 and B2 indicate that feedback is requested at each of the two 242-tone RUs from low frequency to high frequency, and B3-B8 may be reserved and set to 0.

[0223] If the bandwidth of the PPDU carrying the EHT NDP notice frame is 80 MHz, B0 can be set to 0 to indicate a resolution of 20 MHz. If B1-B4 are all set to 1, it can indicate that feedback is requested for the 996-tone RU. Otherwise, B1-B4 indicate that feedback is requested for each of the four 242-tone RUs from the low frequency to the high frequency, and B5-B8 can be reserved and set to 0.

[0224] If the bandwidth of the PPDU carrying the EHT NDP notice frame is 160 MHz, B0 can be set to 0 to indicate a resolution of 20 MHz. If B1-B4 are all set to 1, it can indicate that feedback is requested for the lower 996-tone RU; otherwise, B1-B4 can indicate that feedback is requested for each of the four 242-tone RUs from the low frequency to the high frequency in the lower 80 MHz. If B5-B8 are all set to 1, it can indicate that feedback is requested for the upper 996-tone RU; otherwise, B5-B8 can indicate that feedback is requested for each of the four 242-tone RUs from the low frequency to the high frequency in the upper 80 MHz.

[0225] If the bandwidth of the PPDU carrying the EHT NDP notice frame is 320 MHz, B0 can be set to 1 to indicate a resolution of 40 MHz. If both B1 and B2 are set to 1, it can indicate that feedback is requested for the first 996-tone RU; otherwise, B1 and B2 can indicate that feedback is requested for each of the two 484-tone RUs from low to high frequency in the first 80 MHz. If both B3 and B4 are set to 1, it can indicate that feedback is requested for the second 996-tone RU; otherwise, B3 and B4 can indicate that feedback is requested for each of the two 484-tone RUs from low to high frequency in the second 80 MHz. If both B5 and B6 are set to 1, it may indicate that feedback is requested for the third 996-tone RU; otherwise, B5 and B6 may indicate that feedback is requested for each of the two 484-tone RUs from low to high frequency at the third 80 MHz. If both B7 and B8 are set to 1, it may indicate that feedback is requested for the fourth 996-tone RU; otherwise, B7 and B8 may indicate that feedback is requested for each of the two 484-tone RUs from low to high frequency at the fourth 80 MHz. The feedback tone set for each 484-tone RU may consist of the feedback tone set of two 242-tone RUs that overlap with the 484-tone RU.

[0226] The partial bandwidth subfield can have values ​​such as the example in Table 2 depending on the relevant settings.

[0227]

[0228] For TB sounding, the feedback type, Ng subfield, and codebook size subfield can be set according to the example in Table 3.

[0229]

[0230] For non-TB sounding, the feedback type and Ng subfield and codebook size subfield can be set according to the example in Table 4.

[0231]

[0232] The disambiguation subfield is set to 1 to help prevent non-EHT STAs (e.g., VHT STAs) from misinterpreting the field as an AID field.

[0233] In an EHT NDP announcement frame, RA is set to the broadcast address, and the following may apply. If the feedback type and Ng subfields and the codebook size subfield indicate SU or MU, the Nc index subfield is set to a value of Nc-1, where Nc corresponds to the number of columns in the compressed beamforming feedback matrix, and values ​​greater than 7 in the Nc index subfield are reserved. If the feedback type and Ng subfields and the codebook size subfield indicate CQI, the Nc index subfield is set to a value of Nc-1, where Nc corresponds to the number of STS (space-time streams), and values ​​greater than 7 in the Nc index subfield are reserved. One or more STA Info fields may exist.

[0234] In an EHT NDP notice frame having a single STA Info field, the RA field is set to an individual address, and the Nc index subfield may be reserved.

[0235] Multi-link device (MLD) supporting sub-7 GHz and millimeter wave (mmWave) bands

[0236] Multi-link devices (MLDs) defined in 802.11be consist of affiliated APs (or non-AP STAs) operating on one or more different channels, and have achieved significant improvements in terms of aggregated throughput and average latency. Specifically, they have improved overall network performance by increasing total throughput and reducing average latency.

[0237] In particular, while existing MLDs have fundamentally set the sub-7 GHz band (e.g., the band between 2.4 GHz and 7.25 GHz) as the target band, research is being conducted to include APs (or non-AP STAs) belonging to MLDs operating on the mmWave band (e.g., the unlicensed band between 42 GHz and 71 GHz) as the need for the millimeter wave (mmWave) band, which offers powerful throughput and improved latency, has recently increased. Therefore, it is essential to resolve the problems arising from the inclusion of APs (or non-AP STAs) belonging to MLDs operating on the mmWave band.

[0238] FIG. 14 illustrates an AP MLD and a non-AP MLD that support the mmWave band and can be applied to the present disclosure.

[0239] It can be assumed that AP 1, belonging to the AP MLD, is operating on a sub-7 GHz band channel, AP 3, belonging to the AP MLD, is operating on a mmWave band channel, STA 1, belonging to the non-AP MLD, supports the sub-7 GHz band, and STA 2 supports the mmWave band. Therefore, the non-AP MLD may request a multi-link setup from the AP MLD so that STA 1 can be coupled with AP 1 (e.g., on Link 1) and STA 2 can be coupled with AP 3 (e.g., on Link 2).

[0240] To this end, in a multi-link operation (MLO), at least one process can be performed in the process exemplified in FIG. 15.

[0241] FIG. 15 illustrates the discovery and multi-link setup process for multi-link operation in a wireless communication system applicable to the present disclosure.

[0242] 1) Legacy Discovery: Non-AP MLDs can detect the existence of an AP MLD through a scanning process by receiving beacon frames or sending probe request frames. In particular, one or more APs (e.g., AP 1) belonging to an AP MLD can include a basic multi-link (ML) element in a beacon frame or probe response frame to indicate that AP 1 belongs to the AP MLD and provide some information about the AP MLD to which AP 1 belongs.

[0243] 2) Multi-link probing: One or more STAs (e.g., STA 1) belonging to a non-AP MLD, specifically a non-AP MLD, may discover one or more APs (e.g., AP 1) belonging to an AP MLD and request information from AP 1 about one or more other APs (e.g., AP 2 and / or AP 3) belonging to the AP MLD to which AP 1 belongs. Specifically, STA 1, which belongs to a non-AP MLD and has discovered AP 1, may request information about one or more other APs belonging to the AP MLD by using a multi-link probe request frame, which is a probe request frame containing a probe request multi-link (ML) element.

[0244] AP 1 (or AP MLD) that receives a multi-link probe request frame may, in response to this, transmit a multi-link probe response frame, which is a probe response frame containing basic multi-link elements, to STA 1 (or non-AP MLD) that belongs to a non-AP MLD and transmitted the multi-link probe request frame. Here, based on the request information of the multi-link probe request frame, AP 1 may transmit the multi-link probe response frame including a partial profile or a complete profile of one or more other APs belonging to the AP MLD.

[0245] 3) Multi-link setup: A non-AP MLD, specifically one or more STAs belonging to the non-AP MLD (e.g., STA 1), may select an appropriate AP based on information from one or more APs belonging to the AP MLD (e.g., AP 1) and request a multi-link setup from AP 1. To this end, STA 1 (or the non-AP MLD) may transmit a combination request frame containing basic multi-link elements to AP 1 (or the AP MLD). The basic multi-link elements include which AP each STA belonging to the non-AP MLD wishes to request combination with, and the complete profile of each STA belonging to the non-AP MLD requesting combination.

[0246] An AP MLD (e.g., AP 1) that has received a request for a multi-link setup determines whether to accept or reject a specific STA and a specific AP to form a combination based on information regarding the non-AP MLD and the STAs belonging to the non-AP MLD, and transmits a combination response frame to the non-AP MLD (e.g., STA 1). Here, the combination response frame includes basic multi-link elements and contains information such as a status code indicating whether the combination request is accepted or rejected, and a complete profile of each AP belonging to the AP-MLD that received the combination request.

[0247] Initiation of a beam-related procedure in the millimeter wave band in the sub-7 GHz band

[0248] The millimeter wave (mmWave) band is characterized by the need for directional transmission due to its relatively small range and / or coverage. This can increase the complexity of protocols and implementations for beamforming, control, and / or management.

[0249] Therefore, as shown in the process of Fig. 15, if a STA operating in the sub-7 GHz band can control and / or manage instead of a STA operating in the mmWave band, the mmWave band can be used more efficiently. In particular, beamforming training (BFT) between the STA and the AP is required, which is one of the essential elements for directional transmission in the mmWave band. While frame exchange for performing BFT can be performed in the mmWave band, announcement or negotiation regarding the period and / or related parameters for BFT can be performed in the sub-7 GHz band, thereby reducing the control / management overhead for BFT in the mmWave band.

[0250] BFT may include sector level sweep (SLS), beam refinement protocol (BRP), etc., defined in existing wireless LAN systems operating in bands above 45 GHz (e.g., based on the IEEE 802.11ay standard) or in bands above 60 GHz (e.g., based on the IEEE 802.11ad standard). The examples described in this disclosure are not limited to the terms SLS and / or BRP and may also apply to BFT expressed by other terms.

[0251] For example, in relation to BFT in the mmWave band in this disclosure, the term sector may be replaced with the term beam. For example, in the examples of this disclosure, SLS may be replaced with the term beam establishment. For example, BRP may be replaced with the term beam tracking. BFT relates to beam-related procedures and / or operations that perform beam establishment and / or beam tracking, and is not limited to specific procedures and / or operations.

[0252] FIG. 16 is a drawing for explaining an example of the operation of a first STA according to the present disclosure.

[0253] In step S1610, the first STA belonging to the first MLD may generate an announcement frame containing information about beam-related procedures.

[0254] For example, the announcement frame may be an unsolicited frame sent to the STA(s). For example, the announcement frame may be an NDP (null data physical layer protocol data unit) announcement frame.

[0255] For example, information regarding beam-related procedures may include one or more of common information common to beam-related procedures or per-user information for each beam-related procedure.

[0256] In some examples, broadcast beam-related procedures are performed based on at least one of the common information, and individual beam-related procedures may be performed based on at least one of the per-user information.

[0257] In some examples, common information is included in a specific STA information field within a notice frame, and a specific AID (association identifier) ​​value of the specific STA information field may indicate that common information is included in the specific STA information field.

[0258] In some examples, based on the disambiguation subfield of the first STA information field in the notice frame being set to 0, the second STA information field in the notice frame indicates that user-per-user information is included, and a specific AID value of the second STA information field may be the same as a specific AID value of the first STA information field.

[0259] In some examples, based on the disambiguation subfield of the first STA information field within the notice frame being set to 0, it may indicate that user-per-user information is included in the first STA information field.

[0260] In some examples, the value of a specific Nc field of a first STA information field within a notice frame indicates that user-per-information is included in a second STA information field within a notice frame, and a specific AID value of the second STA information field may be the same as a specific AID value of the first STA information field.

[0261] In some examples, the value of a specific Nc field of the first STA information field within the notice frame may indicate that user-per-information is included in the first STA information field.

[0262] For example, the first STA information field within the notice frame may be the existing STA information field described in Examples 2-1 and 2-2 below, and the second STA information field within the notice frame may be the additional STA information field described in Examples 2-1 and 2-2 below.

[0263] In some examples, user-per-user information is included in the third STA information field within the notice frame, and a specific AID value of the third STA information field is the same as a specific AID value of the first STA information field and the second STA information field within the notice frame, and the third STA information field may be placed after the first STA information field and the second STA information field.

[0264] For example, the first STA information field, the second STA information field, and the third STA information field within the notice frame may be the first information field, the second information field, and the third information field in Examples 2-3 described below, respectively.

[0265] In some examples, one or more of the type subfields or subtype subfields may indicate that one or more of common information or user-per-user information are included in the notice frame.

[0266] In step S1620, the first STA can transmit a notification frame to the second STA belonging to the second MLD on the first link.

[0267] In some examples, based on information regarding beam-related procedures, beam-related procedures may be performed in the second link by the third STA belonging to the first MLD and the fourth STA belonging to the second MLD.

[0268] For example, in a beam-related procedure, the third STA may be the initiator and the fourth STA may be the responder, or the third STA may be the responder and the fourth STA may be the initiator.

[0269] In some examples, the beam-related procedure in the second link may include: a beam-related procedure for one or more of the transmitting beam of the third STA or the receiving beam of the fourth STA; or a beam-related procedure for one or more of the transmitting beam of the fourth STA or the receiving beam of the fourth STA.

[0270] For example, the first link may be included in the sub-7 GHz band, and the second link may be included in the millimeter wave (mmWave) band.

[0271] For example, beam-related procedures may include one or more beam establishment procedures or beam tracking procedures.

[0272] For example, the first MLD may be an AP (access point) MLD and the second MLD may be a non-AP MLD.

[0273] Specifically, based on information regarding beam-related procedures included in a notice frame transmitted by the first STA to the second STA in the sub-7 GHz band, STAs operating in the mmWave band can perform beam-related procedures.

[0274] In some examples, the information regarding the beam-related procedure may include one or more of the following: information regarding the start time, information regarding the number of transmitted beams, information regarding the maximum value of the number of transmitted beams, information regarding the number of transmitting antennas, information regarding the maximum value of the number of transmitting antennas, information regarding the number of receiving antennas, information regarding the maximum value of the number of receiving antennas, information regarding the length of the receiving beam establishment, information regarding the maximum value of the receiving beam establishment length, or information regarding the type of the beam-related procedure. For example, the number of transmitted beams may be less than or equal to the maximum value of the number of transmitted beams, the number of transmitting antennas may be less than or equal to the maximum value of the number of transmitting antennas, the number of receiving antennas may be less than or equal to the maximum value of the number of receiving antennas, and the length of the receiving beam establishment may be less than or equal to the maximum value of the receiving beam establishment length.

[0275] Information regarding beam-related procedures may include various information in addition to the information described above, and specific examples thereof are explained below.

[0276] In the following examples, for clarity of explanation, the terms sector, sector level sweep (SLS), beam refinement protocol (BRP), and beamforming training (BFT) are used, but each may include other terms as described above or be replaced with other terms.

[0277] The method described in the example of FIG. 16 can be performed by the first device (100) of FIG. 1. For example, one or more processors (102) of the first device (100) of FIG. 1 may be configured to generate a notification frame containing information about a beam-related procedure and to transmit the notification frame to a second STA belonging to the second MLD through one or more transceivers (106). Furthermore, one or more memories (104) of the first device (100) may store instructions for performing the method described in the example of FIG. 16 or the examples described below when executed by one or more processors (102).

[0278] For example, the memory (104) may store one or more pieces of information regarding a STA operating in a mmWave band belonging to a multi-link device according to the present disclosure. Based on the information stored in the memory (104), the processor (102) may generate a known frame, generate an RU, generate a PPDU, and transmit the generated PPDU through the transceiver (106). Additionally, the processor (102) may generate a transmitted PPDU and store information regarding the transmitted PPDU in the memory (104). For example, the processor (102) may be configured to generate a PPDU / frame containing one or more pieces of information regarding a STA operating in a mmWave band belonging to a multi-link device and transmit it through the transceiver (106).

[0279] FIG. 17 is a drawing for explaining an example of the operation of a second STA according to the present disclosure.

[0280] In step S1710, the second STA can receive a notification frame from the first STA at the first link.

[0281] In step S1720, the second STA can process information regarding beam-related procedures included in the notice frame.

[0282] In the example of FIG. 17, details regarding information on beam-related procedures, beam-related procedures, notice frames, etc. are the same as those in the example of FIG. 16, so redundant descriptions are omitted.

[0283] The method described in the example of FIG. 17 may be performed by the second device (200) of FIG. 1. For example, one or more processors (202) of the second device (200) of FIG. 1 may be configured to receive a notice frame containing information about a beam-related procedure in the first link from a first STA belonging to the first MLD via one or more transceivers (206), and to process the information about the beam-related procedure included in the notice frame. Furthermore, one or more memories (204) of the second device (200) may store instructions for performing the method described in the example of FIG. 17 or the examples described below when executed by one or more processors (202).

[0284] For example, the memory (204) may store one or more pieces of information regarding a STA operating in a mmWave band belonging to a multi-link device according to the present disclosure. The transceiver (206) may receive a PPDU based on the control of the processor (202). The PPDU received through the transceiver (206) may be stored in the memory (204). For example, the processor (202) may acquire control information regarding the bandwidth / tone-plan / RU included in the PPDU (e.g., information included in the SIG field of the PPDU) and store the acquired control information in the memory (204). The processor (202) may perform decoding on the received PPDU. For example, it may perform operations to restore the results of cyclic shift delay (CSD), spatial mapping, inverse discrete Fourier transform (IDFT) / inverse fast Fourier transform (IFFT) operations, and guard interval (GI) insertion applied to the PPDU. Additionally, the processor (202) can decode the data field of the PPDU received through the transceiver (206) and process the decoded data. For example, the processor (202) can transmit information regarding the decoded data field to an upper layer (e.g., MAC layer). Additionally, 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, subsequent operations can be performed. For example, the processor can parse the MAC PDU obtained through PHY decoding of the DATA field of the PPDU received through the transceiver (206).

[0285] Additionally, the processor (202) may be configured to acquire one or more pieces of information regarding a STA operating in a mmWave band belonging to a multi-link device included in a notice frame included in a MAC PDU, and to perform an operation accordingly. For example, the processor (202) of the receiving device may be configured to perform an operation of a second STA according to an example of the present disclosure. For example, the processor (202) may store one or more pieces of information regarding a STA operating in a mmWave band belonging to a multi-link device received through a notice frame in a memory (204).

[0286] In the examples of FIGS. 16 and 17, the first STA may transmit one or more PPDU / frames containing information about beam-related procedures. For example, the information about beam-related procedures may include common information about beam-related procedures and / or user-specific information about beam-related procedures.

[0287] The examples of FIGS. 16 and 17 may correspond to some of the various examples of the present disclosure. Hereinafter, various examples of the present disclosure including the examples of FIGS. 16 and 17 will be described in more detail.

[0288] In describing the present disclosure, for convenience of explanation, the primary focus is on cases including APs and / or non-AP STAs operating in the sub-7 GHz band within an MLD and APs and / or non-STAs operating in the mmWave band. In the present disclosure, for convenience of explanation, a STA or AP operating in the mmWave band belonging to the same MLD may be referred to as an mSTA or mAP, respectively, and a STA or AP operating in the sub-7 GHz band belonging to the same MLD may be referred to as an sSTA or sAP, respectively.

[0289] Additionally, names and the like referred to in this disclosure are for convenience of explanation and may be changed to other equivalent names. Unless otherwise noted in this disclosure, STAs may perform the functions of AP STAs and / or non-AP STAs. Additionally, MLDs may perform the functions of AP MLDs and / or non-AP MLDs.

[0290] In the present disclosure, an mSTA initiating BFT is referred to as the BFT initiator, and at least one mSTA performing BFT with the BFT initiator may be referred to as the BFT responder. The BFT is not limited to cases where an AP is the initiator and a non-AP STA is the responder. For example, the initiator may be a non-AP STA and the responder may be an AP STA. For example, the initiator may be an AP and the responder may be an AP. For example, the initiator may be a non-AP STA and the responder may be a non-AP STA.

[0291] The present disclosure describes a method for managing periods and / or BFT-related parameters for BFT in the mmWave band based on a known basis in the sub-7 GHz range.

[0292] sAP can provide common information about BFT that is common to all mAPs and per-user information for each mAP (e.g., intervals and / or related parameters of BFT) through BFT announcement frames (e.g., NDP (null data physical layer protocol data unit) announcement frames).

[0293] FIG. 18 illustrates an example of disclosing a BFT through a known frame containing information about the BFT according to the present disclosure.

[0294] As shown in FIG. 18, an sAP belonging to an AP MLD may transmit a notice frame containing one or more of BFT common information or BFT user-per-user information to an sSTA 1 belonging to a non-AP MLD 1 on Link 1. Accordingly, the sAP may inform sSTA 1 of information regarding the BFT step.

[0295] For example, BFT common information may be information common to BFT 1 and BFT 2. For example, BFT 1 user-per-user information related to BFT 1 performed on Link 2 by mAP belonging to AP MLD and mSTA 1 belonging to non-AP MLD 1 may be included in the public frame. Additionally, BFT 2 user-per-user information related to BFT 2 performed by mAP belonging to AP MLD and mSTA 2 belonging to non-AP MLD 2 may be included in the public frame.

[0296] For example, mSTA 1 can perform BFT 1 at Link 2 based on BFT common information and / or BFT 1 user-per-user information. Additionally, mSTA 2 can perform BFT 2 at Link 2 based on BFT common information and / or BFT 2 user-per-user information.

[0297] Additionally, the announcement frame (AF) may be a beacon frame, probe response frame, or combined response frame transmitted periodically as shown in FIG. 15. Alternatively, the announcement frame may be defined as a separate frame (e.g., an action frame) to convey information about the BFT.

[0298] Additionally, a response frame (e.g., CTS (clear-to-send), multi-STA blockack, etc.) can be defined in response to the notification frame.

[0299] Basically, to request BFT intervals and / or BFT-related parameters in the sub-7 GHz band, the notice frame may consist of one or more pieces of information, such as common information about the BFT or per-user information about the BFT. Parameters corresponding to each piece of information may be included in the notice frame in the form of fields and / or subfields.

[0300] Common information for BFT refers to information common to BFTs performed in the mmWave band and may include one or more of the information regarding broadcast BFTs described below. Through this common information for BFT, identical time scheduling information for the BFT can be communicated to two or more respondents. This common information can be used when a BFT is performed simultaneously for two or more respondents, thereby enabling the BFT to be performed for all respondents in the sub-7 GHz band with a single notification.

[0301] 1) Broadcast BFT indication: Broadcast BFT indication information is information regarding whether to perform a broadcast BFT, and may consist of a 1-bit simple indication and / or an index of 2-bit or more.

[0302] When composed of an index of 2 bits or more, broadcast BFT instruction information may include broadcast BFT type information, in which case parameters for broadcast BFT type information may be omitted in the request frame. For example, 0 may be no broadcast BFT, 1 may be broadcast BFT-ISS (initiator sector sweep), 2 may be broadcast BFT-RSS (responder sector sweep), 3 may be broadcast BFT-unsolicited RSS, 4 may be broadcast BFT-SLS, 5 may be broadcast BFT-BRP, and 6 may be broadcast BFT-full (including SLS and BRP).

[0303] Alternatively, broadcast BFT instruction information may also be configured as a bitmap. For example, B1(0), B2(0), B3(0), and B4(0) may be broadcast BFT-No, B1(1), B2(0), B3(0), and B4(0) may be broadcast BFT-ISS, B1(0), B2(1), B3(0), and B4(0) may be broadcast BFT-RSS, B1(0), B2(1), B3(0), and B4(1) may be broadcast BFT-Unsubstantiated RSS, B1(1), B2(1), B3(0), and B4(0) may be broadcast BFT-SLS, B1(0), B2(0), B3(1), and B4(0) may be broadcast BFT-BRP, and B1(1), B2(1), B3(1), and B4(0) may be broadcast BFT-Full (including SLS and BRP). In this case, B1 can be represented as a bit for IsInitiatorTXSS, B2 as IsResponderTXSS, B3 as BRP, and B4 as an RSS for non-petitioning.

[0304] 2) Broadcast BFT Schedule ID: The broadcast BFT schedule ID information may be an ID that distinguishes schedules for at least one broadcast BFT phase. For example, the ID may be indicated based on X-bits to indicate the maximum number of possible schedules. Additionally, broadcast BFT schedule IDs may overlap between different broadcast BFT types. In this case, the broadcast BFT schedule ID and the broadcast BFT type can be configured as a 2-tuple to distinguish the BFT schedules.

[0305] 3) Broadcast BFT start time: Broadcast BFT start time information may indicate time information such as the time when a BFT phase (e.g., BFT interval) begins and / or the duration. Additionally, broadcast BFT start time information may be defined using the full timestamp (e.g., 8-octet) of the AP transmitting the information, specifically using the full TSF (timing synchronization function), or using a partial TSF. Additionally, a partial TSF may be indicated using some bits of the 64-bit TSF (e.g., [10:25], [20:35], or the first 4-octet).

[0306] If the BFT start time is indicated using a TSF, the TSF setting for the mAP may not be clear unless the mAP transmits periodic beacons containing the TSF. Specifically, if the sAP provides the SLS service period (SP) for the mAP, but the start time of the SP operates based on the TSF, a method may be required for a non-AP MLD to interpret the mAP's BFT period SP based on the information provided by the sAP. Basically, if the mAP's TSF is not announced by the mAP, the sAP may indicate the TSF for the mAP. Additionally, the TSF for the mAP may be considered as a virtual TSF, which is referred to as mTSF for convenience of explanation in this disclosure.

[0307] Basically, non-AP MLD can determine the TSF offset corresponding to the difference between the mTSF and the TSF of one or more sAPs through multi-link probe requests / responses with the transmitting sAP that transmits the information, or through beacons that the transmitting sAP periodically transmits.

[0308] For example, the SLS start time can be indicated based on the mTSF. A non-AP MLD can determine the SLS start time based on the TSF offset between the transmitting sAP and the mAP. Additionally, the mAP's TSF can be configured to have the same TSF as one or more sAPs other than the transmitting sAP. To this end, the transmitting sAP may include link IDs for one or more sAPs other than the transmitting sAP that have the same TSF as the mAP in common information or per-user information for the BFT. In this case, the non-AP MLD can determine the SLS start time based on the TSF offset between the transmitting sAP and the sAP (which may also include the transmitting sAP) that has the same TSF as the mAP.

[0309] For example, the SLS start time can be indicated based on the TSF of the transmitting sAP that transmits the SLS start time information. The non-AP MLD can determine the SLS start time by calculating it based on the TSF offset between the acquired transmitting sAP and the corresponding mAP. Additionally, the TSF offset may be indicated together for accurate calculation.

[0310] Additionally or alternatively, broadcast BFT start time information may be defined in the form of a target beacon transmission time (TBTT) offset. For example, the difference from the time of transmission of a request frame containing such information to the time of starting the BFT (e.g., the time when a frame initiating the BFT is transmitted) may be indicated in time units (TU). For example, if the difference from the time of transmission of a request frame containing such information to the time of starting the BFT is 1.3 TU, it may be indicated as 1 TU through rounding down. This allows the responder to receive the initiation frame during the BFT phase, taking into account a certain degree of error.

[0311] Additionally, the BFT start time can be included in the frame as TBTT information. For example, the time can be indicated as a value in μs.

[0312] For example, the time may be indicated by a specific unit (e.g., μs). Additionally, information regarding the specific unit may be included in the frame. For example, unit information such as 1 μs, 8 μs, 32 μs, 64 μs, etc., may be included in the frame to indicate the unit for the value of the BFT start time included thereafter. For example, if the valid time corresponding to the BFT start time is 1000 and the unit is 1 μs, it may mean 1 ms. For example, if the valid time corresponding to the BFT start time is 1000 and the unit is 8 μs, it may mean 8 ms.

[0313] 4) Broadcast BFT duration: Broadcast BFT duration information is the duration during which a single BFT phase lasts, and may refer to the time during which a broadcast BFT (e.g., ISS) lasts. In certain cases (e.g., when a list of respondents is included in the frame), it may refer to the total time of the BFT indicated by both common information and per-user information.

[0314] Additionally, the information may be indicated in specific unit units (e.g., 1 μs, 64 μs, 256 μs, 1 TU, etc.). Additionally, specific units may be indicated in a separate field (e.g., 1-bit, 2-bit, etc.).

[0315] Additionally or alternatively, broadcast BFT duration information may represent a maximum or minimum value. Also, the duration may consist of X-bits (e.g., 5-bits, etc.) or X-octets (e.g., 1-octet, 2-octet, etc.).

[0316] 5) Broadcast BFT interval: Broadcast BFT interval information may be information about the interval between consecutive BFT steps (e.g., SLS steps). For example, it may be the interval between the start of one SLS step and the start of the next SLS step, or the interval between the end of one SLS step and the end of the next SLS step.

[0317] FIG. 19 shows examples of BFT intervals according to the present disclosure.

[0318] For example, as shown in Fig. 19(a), when a single BFT step (e.g., SLS step) occurs periodically, the interval between the start times of each BFT step can be an interval.

[0319] In addition, if the broadcast BFT interval is 0, it may mean that only one BFT step is performed. For example, only the left BFT step of FIG. 19(a) may be performed. Alternatively, as in FIG. 19(b), a BFT step may start immediately after one BFT step is completed.

[0320] In addition, as shown in Fig. 19(c), other segment steps may follow in addition to the BFT step.

[0321] Additionally, the periodic repetition of the SLS step can be limited by defining an SLS number (e.g., the number of repeated SLS steps). For example, the number of SLS steps can be represented in X-bits (e.g., 4 bits, 8 bits, etc.), and if the number is 2, no further SLS steps may be performed after 2 SLS steps. Additionally, when one SLS step is performed, the SLS number may decrease by one. Additionally, if the SLS number is 1, the BFT interval (e.g., SLS interval) may be reserved or non-existent.

[0322] 6) Broadcast BFT type: Broadcast BFT type information can indicate the type of BFT performed in the BFT phase. BFT type information can be indicated in an indexed manner. For example, 0 is no broadcast BFT, 1 is broadcast BFT-ISS, 2 is broadcast BFT-RSS, 3 is broadcast BFT-no petition RSS, 4 is broadcast BFT-SLS, 5 is broadcast BFT-BRP, and 6 is broadcast BFT-all (including SLS and BRP).

[0323] Alternatively, BFT type information may also be configured as a bitmap. For example, B1(0), B2(0), B3(0), and B4(0) may be Broadcast BFT-No, B1(1), B2(0), B3(0), and B4(0) may be Broadcast BFT-ISS, B1(0), B2(1), B3(0), and B4(0) may be Broadcast BFT-RSS, B1(0), B2(1), B3(0), and B4(1) may be Broadcast BFT-Unsubstantiated RSS, B1(1), B2(1), B3(0), and B4(0) may be Broadcast BFT-SLS, B1(0), B2(0), B3(1), and B4(0) may be Broadcast BFT-BRP, and B1(1), B2(1), B3(1), and B4(0) may be Broadcast BFT-Full (including SLS and BRP). In this case, B1 can be represented as a bit for IsInitiatorTXSS, B2 as IsResponderTXSS, B3 as BRP, and B4 as an RSS for non-petitioning.

[0324] Alternatively, BFT type information may be indicated by a bitmap. For example, the first bit (which may be, e.g., the LSB or MSB) may indicate whether the SLS is partial or full. The second bit may indicate the direction of the SLS. For example, if 0, the initiator transmits, and if 1, the responder transmits. Or, if 0, the responder transmits, and if 1, the initiator transmits. The third bit may indicate whether the SLS performed by the initiator or responder is a TXSS or an RXSS. For example, if 0, a TXSS is performed, and if 1, an RXSS is performed. Or, if 0, an RXSS is performed, and if 1, a TXSS is performed. The fourth bit may indicate whether BFT refinement is performed.

[0325] For example, broadcast BFT type information may be indicated by a bit sequence such as b0000. In this case, information may be indicated that partial SLS is performed, the initiator performs TXSS, and does not perform BFT refinement.

[0326] In addition, BFT types may also be defined as beam establishment or beam tracking.

[0327] 7) Initiator ID: The initiator ID information may refer to the association identifier (AID) of an STA that can be an initiator of the BFT. Additionally, the AID may be indicated by X bits (e.g., AID X). This may refer to the X-LSBs (least significant bits) of the STA's AID (e.g., X=11, 12, etc.).

[0328] Additionally, the AP's AID may use one of the AID field values ​​that is not assigned to the STA (e.g., 0 of AID12 or 2010 of AID12).

[0329] Additionally or alternatively, to reduce the overhead of the AID field, the initiator ID information parameter may be omitted through a field indicating that the AP is the initiator. For example, through a field indicating that the AP is the initiator, if the value of the field is 1, it may be indicated that the AP is the initiator.

[0330] 8) Responder list: The responder list may include order and time information assigned to one or more respondents within a BFT step (e.g., BFT interval), allowing each responder to perform the BFT sequentially.

[0331] FIG. 20 shows an example of a respondent list and respondent schedule information according to the present disclosure.

[0332] Respondent list information can be included in user-per-user information, in which case it can be omitted from common information regarding BFT.

[0333] As shown in FIG. 20, the responder list may contain multiple responder schedule information. The responder ID may be an AID (e.g., AID11 and / or AID12, etc.). Alternatively, the responder ID may be a MAC address. Additionally, responders may be distinguished by assigning a random ID. Alternatively, the AID may be indicated by X-bits (e.g., AID X). This may refer to the X-LSBs of the STA's AID (e.g., X=11, 12, etc.).

[0334] Depending on the type of broadcast BFT, the responder list may include one or more of the SLS start time, SLS duration, BRP start time, or BRP duration, and if there is no such time schedule, all may be set to 0 (and / or all set to 1) or reserved.

[0335] In addition, to perform the SLS segment as a broadcast ISS and to divide the RSS segments of the responders, the SLS start time of each responder can be designated as the RSS start time of each responder. Also, if one or more of the responder list information (e.g., AID12 of the notice frame or AID11 of the NDP notice frame) are included in the existing frame, such information may be omitted.

[0336] Alternatively, the scheduling order can be determined based on the order of the list by transmitting only the respondent list without including time information for the BFT. In this case, the registrar can determine each respondent's BFT duration and BFT start time using information such as the respondent's number of receiving antennas and sectors. In this case, the respondent can implicitly receive a BFT frame in the mmWave band during their turn.

[0337] Depending on the type of BFT, the responder list may also include necessary information. The RXSS length may indicate the length required to perform RXSS when performing RXSS among SLS types, for example, the total number of receiving sectors. For example, the number of receiving sectors required to perform RXSS may be arbitrarily specified. The RXSS length can be used to determine whether the initiator performs RXSS (I-RXSS). In the case of SLS, information regarding the number of sectors may be included in the responder list depending on the antenna. The total number of sectors corresponding to the number of antennas may be included in the BFT information list-SLS. The BFT list-BRP may include BRP element information, such as BRP request fields and DMG beam refinement elements, defined in existing wireless LAN systems operating in bands above 45 GHz (e.g., based on the IEEE 802.11ay standard) or operating in the 60 GHz band (e.g., based on the IEEE 802.11ad standard). All of the information may be included, or only the necessary parts may be included.

[0338] Additionally, the respondent list may include channel information where SLS and / or BRP are performed. The channel information may be configured identically to the channel information included in the user-per-user information for the BFT described below.

[0339] 9) Time gap: Information regarding the BFT interval may indicate the time gap between the BFT start time and the transmission time of the notice frame. Specifically, the time gap may be the time gap between the BFT start time and the transmission start or completion time of the notice frame. For example, the time gap information may have X-bits (e.g., 5 bits, 8 bits, etc.) to indicate the time gap, and may additionally be indicated by a specific unit (e.g., 1 μs, 64 μs, etc.). In this case, additionally, when recognizing the time gap in the mmWave band, the case where the aforementioned BFT start time is indicated by TSF may be considered.

[0340] FIG. 21 shows an example of a BFT interval indication using a time gap according to the present disclosure.

[0341] FIG. 21 shows an example using the time gap from the time the transmission of the notice frame is completed to the time the SLS starts. For example, the notice frame may be transmitted as a broadcast (e.g., group-addressed), or the notice frame may be transmitted as a unicast (e.g., individual-addressed).

[0342] For example, a time gap can be specified in advance in a probe request / response frame or a (re)combination request / response frame to inform other STAs. In this case, the time gap information can be applied equally to all BFT intervals by default, and additionally, if the time gap information changes, the notification frame can be used to indicate that the time gap information has changed.

[0343] 10) Included TRN (TRN included): The included TRN (training) information may indicate whether the TRN is included. For example, the first bit may indicate whether the transmit training (TRN-T) is included, and the second bit may indicate whether the receive training (TRN-R) is included. The corresponding fields may also be configured separately, and there may be no restrictions on the field configuration or size.

[0344] 11) TRN-T / R Length: TRN-T / R length information indicates the number of TRN units included in the TRN field and may include length information for TRN-T and / or TRN-R. For example, the upper 6 bits may be the length of TRN-T and the lower 6 bits may be the length of TRN-R. The fields may also be configured separately, and there may be no restrictions on the field configuration or size.

[0345] 12) TRN sequence type: TRN sequence type information can indicate a Golay-based sequence type (e.g., GA128, GA256, etc.).

[0346] 13) TRN unit configuration: TRN unit configuration information may represent a combination of TRN-T, TRN-R, or TRN-C (common) subfields within the TRN unit.

[0347] 14) Best sector: Best sector information may include information about the best sector when the mmWave link was activated by a previous BFT or other methods. Based on this information, BFT may be performed only on that best beam rather than the entire sector.

[0348] 15) Best sector group: The best sector group information may include information on the best sector group (e.g., the first best sector, the second best sector, etc.) when the mmWave link was activated by a previous BFT or other methods. Based on this information, BFT may be performed only on the sector group rather than the entire sector.

[0349] 16) Link ID: A link ID indicating which link the BFT included in the common information is performed on may be included in the frame and transmitted. Through this, the information regarding which link the common information for the BFT is from can be identified.

[0350] 17) Total number of sectors: The total number of sectors information may represent the total number of transmit sectors used in the transmit sector sweep for all DMG antennas. For example, the total number of sectors information may include a specific LBIFS (long beamforming interframe space) required for DMG antenna switching. In this case, the number of LBIFS may be one less than the total number of transmit sectors.

[0351] Additionally or alternatively, the total number of sectors information may be composed of a tuple with the number of transmitting DMG antennas. In this case, the total number of sectors may represent the total number of transmitting sectors used in the transmitting sector sweep according to the DMG antennas.

[0352] Additionally or alternatively, if the initiator can specify the number of sectors of the responder (e.g., based on BFT information), the total number of sectors information may be the total number of transmission sectors specified to the responder.

[0353] 18) Start sector: Unlike the total number of sectors, only some sectors (and / or SLS units such as regions) may be performed when performing SLS (or beam establishment). For example, if the total number of sectors is 32 and the start sector is 10 (assuming sectors start from 0), SLS may be performed starting from the 11th sector. Start sector information may be used together with end sector information, and if end sector information is not available, SLS may be performed up to the total number of sectors (e.g., up to the 32nd).

[0354] 19) End sector: Unlike the total number of sectors, only some sectors (and / or SLS units such as regions) may be executed when performing SLS (or beam establishment). For example, if the total number of beams is 32 and the end sector is 15 (assuming sectors start from 0), SLS may be performed up to the 16th sector. End sector information may be used together with start sector information, and if there is no start sector information, SLS may be performed from the first beam to the end beam.

[0355] Information regarding the broadcast BFT is used when assigning the same schedule to multiple respondents and signaling each scheduling, and this information may be omitted when assigning a separate schedule to each respondent.

[0356] Additionally, each parameter may be indicated based on X-bits to indicate the maximum possible number. Additionally, information regarding one or more broadcast BFTs may be known in advance through a multi-link probe request, a multi-link probe response, or a multi-link setup, in which case the corresponding parameter may not be included in the notification frame.

[0357] User-per-user information regarding BFT is information specific to each STA operating in the mmWave band and may include one or more of the BFT information described below. The BFT performed for each STA may be an individual BFT, and the BFT information described below may be information regarding the individual BFT. Through user-per-user information, time scheduling information for the BFT transmitted per link can be notified to each STA. User-per-user information can be used when requesting the simultaneous execution of a BFT from two or more responders, thereby enabling the execution of a BFT for all responders with a single notification in the sub-7 GHz range.

[0358] 1) BFT Schedule ID: The BFT Schedule ID information may be an ID that distinguishes schedules for at least one BFT phase. For example, the ID may be indicated based on X-bits (e.g., 1-bit, 2-bit, etc.) to indicate the maximum number of possible schedules. Additionally, BFT Schedule IDs may overlap between different BFT types. In this case, BFT schedules can be distinguished by configuring the BFT Schedule ID and BFT type in the form of a 2-tuple.

[0359] 2) BFT start time: BFT start time information may indicate time information such as the time when a BFT phase begins and / or its duration (e.g., BFT interval). Additionally, BFT start time information may be defined using the full timestamp (e.g., 8-octet) of the AP transmitting the information, specifically the full TSF (timing synchronization function), or using a partial TSF. Additionally, a partial TSF may be indicated using some bits of the 64-bit TSF (e.g., [10:25], [20:35], or the first 4-octet).

[0360] Additionally or alternatively, BFT start time information may be defined in the form of a target beacon transmission time (TBTT) offset. For example, the difference from the time of transmission of a notice frame containing such information to the time of starting the BFT (e.g., the time when the frame initiating the BFT is transmitted) may be indicated in time units (TU). For example, if the difference from the time of transmission of a notice frame containing such information to the time of starting the BFT is 1.3 TU, it may be indicated as 1 TU through rounding down. This allows the responder to receive the initiation frame during the BFT phase, taking into account a certain degree of error.

[0361] Additionally, the BFT start time can be included in the frame as TBTT information. For example, the time point can be indicated as a value in μs.

[0362] For example, the time may be indicated by a specific unit (e.g., μs). Additionally or alternatively, information regarding a specific unit may be included in the frame. For example, unit information such as 1 μs, 8 μs, 32 μs, 64 μs, etc., may be included in the frame to indicate the unit for the value of the BFT start time included thereafter. For example, if the valid time is 1000 and the unit is 1 μs, it may mean 1 ms, and if the unit is 8 μs, it may mean 8 ms.

[0363] 3) BFT duration: BFT duration information may refer to the duration during which a single BFT phase is sustained.

[0364] Additionally, the information may be indicated in specific unit units (e.g., 1 μs, 64 μs, 256 μs, 1 TU, etc.). Additionally, specific units may be indicated in a separate field (e.g., 1-bit, 2-bit, etc.).

[0365] Additionally or alternatively, BFT duration information may represent a maximum or minimum value. Also, the duration may consist of X-bits (e.g., 5-bits, etc.) or X-octets (e.g., 1-octet, 2-octet, etc.).

[0366] 4) BFT interval: BFT interval information may be information about the interval between consecutive BFT steps (e.g., SLS steps). For example, it may be the interval between the start of one SLS step and the start of the next SLS step, or the interval between the end of one SLS step and the end of the next SLS step.

[0367] For example, as shown in Fig. 19(a), when a BFT step (e.g., SLS step) occurs periodically, the interval between the starting points of each BFT step can be an interval.

[0368] In addition, if the BFT interval is 0, it may mean that only one BFT step is performed. For example, only the left BFT in Fig. 19(a) may be performed. Alternatively, as in Fig. 19(b), a BFT step may start immediately after one BFT step is completed.

[0369] In addition, as shown in Fig. 19(c), other segment steps may follow in addition to the BFT step.

[0370] Additionally, the periodic repetition of the SLS step can be limited by the SLS number (e.g., the number of repeated SLS steps). For example, the number of SLS steps can be represented in X-bits (e.g., 4 bits, 8 bits, etc.), and if the number is 2, no further SLS steps may be performed after 2 SLS steps. Additionally, when one SLS step is performed, the SLS number may decrease by one. Additionally, if the SLS number is 1, the BFT interval (e.g., SLS interval) may be reserved or non-existent.

[0371] 5) BFT type: BFT type information can indicate the type of BFT performed in the BFT phase. BFT type information can be indicated in an indexed manner. For example, 1 can be BFT-ISS, 2 can be BFT-RSS, 3 can be BFT-Unpetitioned RSS, 4 can be BFT-SLS, 5 can be BFT-BRP, and 6 can be BFT-All (including SLS and BRP).

[0372] Alternatively, BFT type information may also be configured as a bitmap. For example, B1(1), B2(0), B3(0), and B4(0) may be BFT-ISS, B1(0), B2(1), B3(0), and B4(0) may be BFT-RSS, B1(0), B2(1), B3(0), and B4(1) may be BFT-Unpetitioned RSS, B1(1), B2(1), B3(0), and B4(0) may be BFT-SLS, B1(0), B2(0), B3(1), and B4(0) may be BFT-BRP, and B1(1), B2(1), B3(1), and B4(0) may be BFT-Whole (SLS and BRP). In this case, B1 may be represented as a bit for whether the initiator TXSS is, B2 as whether the respondent TXSS is, B3 as whether the BRP is, and B4 as whether the unpetitioned RSS is.

[0373] Alternatively, BFT type information may be indicated by a bitmap. For example, the first bit (e.g., LSB or MSB) may indicate whether the SLS is partial or full. The second bit may indicate the direction of the SLS. For example, if 0, the initiator transmits, and if 1, the responder transmits. Or, if 0, the responder transmits, and if 1, the initiator transmits. The third bit may indicate whether the SLS performed by the initiator or responder is a TXSS or an RXSS. For example, if 0, a TXSS is performed, and if 1, an RXSS is performed. Or, if 0, an RXSS is performed, and if 1, a TXSS is performed. The fourth bit may indicate whether BFT refinement is performed.

[0374] For example, BFT type information may be indicated by a bit sequence such as b0100. In this case, information may be indicated that partial SLS is performed, the responder performs TXSS, and does not perform BFT refinement.

[0375] 6) Initiator ID: The initiator ID information may refer to the association identifier (AID) of an STA that can serve as an initiator for the BFT. Additionally, the AID may be indicated by X bits (e.g., AID X). This may refer to the X-LSBs (least significant bits) of the STA's AID (e.g., X=11, 12, etc.).

[0376] Additionally, the AP's AID may use one of the AID field values ​​that is not assigned to the STA (e.g., 0 of AID12 or 2010 of AID12).

[0377] Additionally or alternatively, to reduce the overhead of the AID field, the initiator ID information parameter may be omitted through a field indicating that the AP is the initiator. For example, through a field indicating that the AP is the initiator, if the value of the field is 1, it may be indicated that the AP is the initiator.

[0378] 7) Responder ID: The responder ID may be an AID (e.g., AID11 and / or AID12). Alternatively, the responder ID may be a MAC address. Additionally, a random ID may be assigned to distinguish the responder. Alternatively, the AID may be indicated by an X-bit (e.g., AID X). This may mean the X-LSBs of the STA's AID (e.g., X=11, 12, etc.). Additionally, if information regarding the responder ID is included in an existing frame (e.g., AID12 of a notice frame or AID11 of an NDP notice frame), that information may be omitted.

[0379] 8) Number of TX DMG antennas: This may be information regarding the number of transmitting antennas performing BFT. For example, it may be the total number of transmitting DMG antennas performing BFT. The total number of transmitting DMG antennas may be the maximum value of the number of transmitting DMG antennas.

[0380] For example, the number of transmitting DMG antennas to perform BFT may be specified. In this case, the specified number of transmitting DMG antennas may be less than or equal to the maximum number of transmitting DMG antennas.

[0381] 9) Number of RX DMG antennas: This may be information regarding the number of receiving antennas performing BFT. For example, it may be the total number of receiving DMG antennas performing BFT. The total number of receiving DMG antennas may be the maximum value of the number of receiving DMG antennas.

[0382] For example, the number of receiving DMG antennas to perform BFT may be specified. In this case, the specified number of receiving DMG antennas may be less than or equal to the maximum number of receiving DMG antennas.

[0383] 10) BRP request: A BRP request field defined in existing wireless LAN systems operating in bands above 45 GHz (e.g., based on the IEEE 802.11ay standard) or in bands above 60 GHz (e.g., based on the IEEE 802.11ad standard) may be included in the frame. The entire BRP request information may be included, or only some of the necessary information may be included.

[0384] 11) DMG beam refinement element: The DMG beam refinement element information described above in the present disclosure may be included in the information regarding the BFT. The entirety of such information may be included, or only some of the necessary information may be included.

[0385] 12) RXSS length: When performing RXSS among SLS types, this may be length information for performing RXSS. For example, it may indicate the total number of receiving sectors. The total number of receiving sectors may be the maximum value of receiving sectors (specifically, the maximum value of RXSS length). Specifically, the total number of receiving sectors may correspond to the number of receiving sectors when performing full SLS.

[0386] For example, the number of receiving sectors for performing RXSS may be arbitrarily specified. In this case, the specified number of receiving sectors may be less than or equal to the maximum number of receiving sectors. Specifically, the specified number of receiving sectors may correspond to the number of receiving sectors when performing partial SLS.

[0387] Whether to perform initiator-RXSS (I-RXSS) can be determined using RXSS length information.

[0388] 13) BFT channel: A channel in which BFT is performed may be specified. The channel may vary depending on channeling in the mmWave band. Basically, the channel can be determined by a combination using one or more of the following information.

[0389] A. Bandwidth (BW): The bandwidth of the corresponding channel may be specified. Additionally, it may be specified in X-bits, taking into account the maximum possible bandwidth. For example, one or more of 320 MHz, 640 MHz, 1280 MHz, or 2560 MHz may be specified by configuring in 2-bits.

[0390] B. Channel Index: The index of the channel corresponding to the bandwidth may be indicated. Additionally, it may be indicated by X bits considering the maximum possible index. For example, if there are 8 channels capable of 320 MHz in a 2.16 GHz channel, which 320 MHz channel is indicated by 3 bits. Additionally, if there is at least one 2.16 GHz channel, which 2.16 GHz channel is indicated as well. For example, if there are 4 2.16 GHz channels, which 2.16 GHz channel is indicated by 2 bits.

[0391] Additionally or alternatively, instead of separately indicating which channel it is, which 2.16 GHz channel and which 320 MHz channel it is can be indicated by a single channel index. For example, as in the example above, if there are 4 2.16 GHz channels and 8 320 MHz channels within one 2.16 GHz channel, the total number of channels is 32, and the channel indices can be indicated sequentially using 5 bits. For example, if the channel where the BFT is performed is the second 2.16 GHz channel and the first 320 MHz channel within it, assuming the channel index starts from 0, the channel index can be 8.

[0392] Additionally, the location of the primary channel in the corresponding channel can be indicated. For example, using an ordered channel index (e.g., frequency-based ascending order) and if the primary channel is based on 320 MHz, the location of the primary channel can be indicated.

[0393] 14) Time gap: Information regarding the BFT interval may indicate the time gap between the BFT start time and the transmission time of the notified frame. Specifically, the time gap may be the time gap between the BFT start time and the transmission start or completion time of the notified frame. For example, the time gap information may have X-bits (e.g., 5 bits, 8 bits, etc.) to indicate the time gap, and may additionally be indicated by a specific unit (e.g., 1 μs, 64 μs, etc.). In this case, additionally, when recognizing the time gap in the mmWave band, the case where the aforementioned BFT start time is indicated by TSF may be considered.

[0394] FIG. 21 shows an example using the time gap from the time the transmission of the notice frame is completed to the time the SLS starts. For example, in FIG. 21, the notice frame may be transmitted as a broadcast (e.g., group-addressed), or the notice frame may be transmitted as a unicast (e.g., individual-addressed).

[0395] For example, a time gap can be specified in advance in a probe request / response frame or a (re)join request / response frame to inform other STAs. In this case, the time gap information can be applied equally to all BFT intervals by default, and additionally, if the time gap information changes, the notification frame can be used to indicate that the time gap information has changed.

[0396] 15) Link ID: A link ID indicating which link the BFT included in the user-per-user information is performed on may be included in the frame and transmitted. Through this, the user-per-user information regarding the BFT can be identified as belonging to which link.

[0397] 16) Total number of sectors: The total number of sectors information may represent the total number of transmit sectors used in the transmit sector sweep for all DMG antennas. For example, the total number of sectors information may include a specific LBIFS (long beamforming interframe space) required for DMG antenna switching. In this case, the number of LBIFS may be one less than the total number of transmit sectors.

[0398] Additionally or alternatively, information on the total number of sectors may be composed of a tuple with the number of transmitting DMG antennas. In this case, the total number of sectors may represent the total number of transmitting sectors used in the transmitting sector sweep according to the DMG antennas.

[0399] Additionally, if the initiator can specify the number of sectors of the responder (e.g., based on BFT information), the total number of sectors information may be the total number of transmission sectors specified to the responder.

[0400] 17) Included TRN (TRN included): The included TRN (training) information may indicate whether the TRN is included. For example, the first bit may indicate whether the transmit training (TRN-T) is included, and the second bit may indicate whether the receive training (TRN-R) is included. The corresponding fields may also be configured separately, and there may be no restrictions on the field configuration or size.

[0401] 18) TRN-T / R Length: TRN-T / R length information indicates the number of TRN units included in the TRN field and may include length information for TRN-T and / or TRN-R. For example, the upper 6 bits may be the length of TRN-T and the lower 6 bits may be the length of TRN-R. The fields may also be configured separately, and there may be no restrictions on the field configuration or size.

[0402] 19) TRN sequence type: TRN sequence type information can indicate Golay-based sequence types (e.g., GA128, GA256, etc.).

[0403] 20) TRN unit configuration: TRN unit configuration information may represent a combination of TRN-T, TRN-R, or TRN-C (common) subfields within the TRN unit.

[0404] 21) Best sector: Best sector information may include information about the best sector when the mmWave link was activated by a previous BFT or other methods. Based on this information, BFT may be performed only on that best beam rather than the entire sector.

[0405] 22) Best sector group: The best sector group information may include information on the best sector group (e.g., the first best sector, the second best sector, etc.) when the mmWave link was activated by a previous BFT or other methods. Based on this information, BFT may be performed only on the sector group rather than on the entire sector.

[0406] Additionally, each parameter may be indicated based on X-bits to indicate the maximum possible number. Additionally, information regarding one or more BFTs may be known in advance through a multi-link probe request, a multi-link probe response, or a multi-link setup, etc., in which case the corresponding parameter may not be included in the notification frame.

[0407] Example 1

[0408] Common information regarding the aforementioned BFT may be included in a notification frame (e.g., an NDP notification frame) in one or more ways of the following embodiments. An NDP notification frame containing common information regarding the BFT may be applied as an initial control frame (ICF) and / or control frame (CF) request role.

[0409] Example 1-1

[0410] Common information about BFT can be included in the STA information field of the NDP notification frame.

[0411] FIG. 22 shows an STA information field format including BFT common information according to the present disclosure.

[0412] To include common information about BFT in the NDP notification frame, the STA information field can be configured using a specific value of the special AID. For example, as shown in the example of FIG. 22(a), the STA information field containing common BFT information can be configured using a specific value of the AID11 field (e.g., 2008). The special AID can be any one of the reserved values ​​(e.g., 2008 to 2047).

[0413] In this disclosure, examples of AID values ​​are described as values ​​such as 2008 or 2018, but the scope of this disclosure is not limited thereto.

[0414] Additionally, by using a specific value of a special AID, BFT common information can be included in the STA information field, and if the size of the BFT common information increases considering the size of the STA information field, it is possible to sequentially indicate that BFT common information is included in the STA information field with the same AID. For example, as shown in the example of FIG. 22(b), by using a specific value of AID11 (e.g., 2008), it is possible to sequentially indicate that there are STA information fields containing BFT common information with the same AID.

[0415] For example, when instructing sequentially, it is possible to instruct that multiple STA information fields are continuously connected to the same AID by using a continue bit (e.g., utilizing reserved bits B20 or B29 to B31 of the STA information field within the EHT NDP notification frame) or by including length information such as a length subfield.

[0416] Examples 1-2

[0417] A BFT information flag may exist in a field containing BFT common information to indicate whether common information regarding the BFT exists in the padding field. Depending on the indication of the flag, BFT common information may be included in the padding area. Alternatively, the BFT information flag may not exist in the field containing BFT common information, and information regarding the BFT may always be included in the padding field.

[0418] Additionally, the configuration of BFT common information can be applied in various ways, such as the aforementioned bit index and ID-based methods. Furthermore, depending on the NDP announcement frame variant, AID12 or AID13 may be used instead of AID11.

[0419] Examples 1-3

[0420] FIG. 23 shows examples of frame formats containing BFT common information that can be applied to the present disclosure.

[0421] As shown in the example of FIG. 23(a), to distinguish common information for BFT from common information for other features, the NDP notice frame may include a type subfield (e.g., a 4-bit feedback type subfield).

[0422] For example, BFT common information may include a type subfield, a length subfield (and / or a subfield indicating the number of pieces of information), and / or an existence bitmap subfield. The length subfield may be used for future extension purposes, and the length subfield may be omitted.

[0423] The existence bitmap subfield can be used to indicate whether information regarding the BFT corresponding to each type is included, such as common information, per-user information, or report information (e.g., feedback on the BFT). The existence bitmap subfield is provided in the form of a bitmap and can indicate whether information regarding the BFT of various functions is included. If the inclusion of information regarding the BFT is determined and cannot be omitted, the existence bitmap subfield may not be included in the NDP notification frame. For example, if the field(s) regarding the BFT are always present, it is unnecessary to indicate the existence (or inclusion) of each of those field(s), so the existence bitmap may not be defined or included.

[0424] Alternatively, as shown in FIG. 23(b), BFT common information may be composed of a type subfield and a subtype subfield. For example, the type may be indicated as information about the BFT, and the subtype may be indicated by defining the type of information about the BFT (e.g., common information about the BFT, user-per-user information about the BFT, or BFT report information, etc.).

[0425] The subtype subfield may also be configured with a length subfield (and / or a subfield indicating the number of pieces of information) and / or an existence bitmap subfield. The length subfield or the existence bitmap subfield may be omitted.

[0426] For example, as shown in the example of FIG. 23(c), the AID11 value of the STA information field may be set to 2008 to include common information for BFT in the STA information field. One or more parameters corresponding to broadcast BFT information may be included in the STA information field as BFT common information.

[0427] To include broadcast BFT information that can serve as common information for BFT in the STA information field, the broadcast BFT instruction can be set to 1. The start time (ST), duration, and interval, etc., can be included in the STA information field as information that announces the BFT schedule commonly in AP MLD. Additionally, the BFT type, initiator ID, time gap, etc., can be included in the STA information field. The aforementioned responder list can be omitted from the common BFT information, assuming that it is included in the BFT user-per-user information.

[0428] Example 2

[0429] User-per-user information regarding the aforementioned BFT may be included in an NDP notification frame in one or more ways of the following embodiments. An NDP notification frame containing user-per-user information regarding the BFT may be applied as an initial control frame (ICF) and / or control frame (CF) request role.

[0430] Example 2-1

[0431] User-party information regarding BFT can be included in the STA information field of the NDP notification frame.

[0432] FIG. 24 shows examples of STA information field formats containing user-party information using ambiguity-resolving subfields according to the present disclosure.

[0433] As shown in the example of FIG. 24(a), the disambiguation subfield of the existing STA information field within the NDP notification frame can be set to 0 to indicate that there is an additional STA information field of a new format containing user-per-user information for the BFT following the existing STA information field (e.g., a user-per-user STA information field). For example, if the disambiguation subfield is set to 0, the additional STA information field having the same specific AID value (e.g., AID11) as the existing STA information field can be newly configured as user-per-user information for the BFT.

[0434] Alternatively, if an additional STA information field having the same AID as the existing STA information field (e.g., AID11) is placed after the existing STA information field, it may implicitly indicate that BFT user-per-information is included in that STA information field.

[0435] Alternatively, as in the example of FIG. 24(b), the ambiguity-resolving subfield of the STA information field may be set to 0 to indicate that there is an additional STA information field (e.g., a user-per-STA information field) of a new format containing BFT user-per-information in the STA information field. When the ambiguity-resolving subfield is set to 0, the current STA information field may be newly configured with user-per-information for the BFT.

[0436] Alternatively, the value of a reserved bit (e.g., B31) of an NDP notice frame other than the ambiguity resolution subfield may be used to indicate whether BFT user-per-information is included in additional STA information fields.

[0437] Example 2-2

[0438] FIG. 25 shows examples of STA information field formats containing user-per-user information using the Nc subfield according to the present disclosure.

[0439] When an NDP notification frame is individually addressed, a specific value (e.g., 1 to 7) is set in the reserved Nc subfield of the existing STA information field to indicate that there is an additional STA information field of a new format containing BFT user-per-STA information following the existing STA information field (e.g., user-per-STA information field), as in the example of FIG. 25(a).

[0440] For example, if a specific value (e.g., 1) is set in the reserved Nc subfield, an additional STA information field having the same specific AID (e.g., AID11) value as the existing STA information field can be newly configured as user-per-information for the BFT.

[0441] Additionally, if an additional STA information field having the same AID as the existing STA information field (e.g., AID11) is placed after the existing STA information field, it may implicitly indicate that user-per-information for the BFT is included in that STA information field.

[0442] Alternatively, by setting a specific value (e.g., 1 to 7) in the reserved Nc subfield of the STA information field of the NDP notice frame, it may be indicated that there is an additional STA information field of a new format containing BFT user-per-user information in the STA information field (e.g., a user-per-user STA information field), as in the example of FIG. 25(b).

[0443] For example, if a specific value (e.g., 1) is set in the reserved Nc subfield, the current STA information field can be reconfigured with user-per-information for BFT.

[0444] Examples 2-3

[0445] FIG. 26 shows examples of frame formats containing BFT user-per-user information according to the present disclosure.

[0446] BFT user-per-information is included in the STA information field within the NDP notification frame according to the examples above, and if the same AID (e.g., AID11) appears, it can be interpreted that user-per-information for the BFT is implicitly included in the STA information field.

[0447] For example, the first and second information fields containing an AID11 field become existing STA information fields, and the third information field containing the same AID11 field can be interpreted as indicating user-per-user information for BFT. Accordingly, the third information field may contain IMMW information depending on the IMMW type (and / or subtype).

[0448] Additionally, the IMMW information may contain one or more information bits, and it may be indicated whether additional IMMW information fields with the same AID11 are subsequently included.

[0449] In the example of FIG. 26(a), the NDP notification frame contains only one STA information field, but as described above, if more information about BFT is included, the IMMW information may be composed of multiple STA information fields (e.g., starting from the third STA information field in the case of the UHR NDP notification frame format).

[0450] In addition, IMMW information may be configured as shown in the example of FIG. 26(b), and BFT type information may be included in the NDP notification frame.

[0451] For example, as shown in the example of FIG. 26(c), user-per-user information for BFT can be included in the STA information field of the NDP notification frame. An ambiguity resolution field (e.g., B27) can be used to indicate that BFT user-per-user information is included in the STA information field, and parameters corresponding to BFT user-per-user information may be included.

[0452] FIGS. 27 through 29 show examples of known-based BFT signaling for initiating BFT according to the present disclosure.

[0453] Specifically, FIGS. 27 through 29 illustrate a method for performing BFT in the mmWave band based on common information about BFT and / or user-per-user information about BFT included in a notice frame transmitted in the sub-7 GHz band.

[0454] The BF PPDU / frame of the present disclosure is a PPDU / frame transmitted to perform BFT, and the BF feedback PPDU / frame may be a PPDU / frame that transmits BFT result information obtained through the BF PPDU / frame. For example, the BF PPDU / frame may be one or more of an SSW frame, a DMG beacon frame, an SSW-feedback frame, an SSW-Ack frame, or a BRP frame.

[0455] The BF PPDU / frame and BF feedback PPDU / frame may be BF PPDU / frames used in existing DMGs or new PPDU / frames, and the scope of the present disclosure is not limited thereto. Additionally, no specific format for the BF PPDU / frame is provided, and the BF PPDU / frame and BF feedback PPDU / frame may contain sufficient information to perform BFT.

[0456] In FIGS. 27 to 29, the BF frame is used, but it can be replaced with a BF PPDU. Additionally, in FIGS. 27 to 29, information regarding the schedule ID, BFT channel, etc. is omitted, but the corresponding information can be assigned to each schedule by the method described above in the present disclosure.

[0457] The examples described below do not include performing BFT (e.g., sector sweep) for each number of transmitting and receiving antennas, but the multi-antenna method is not excluded in principle. In the case of a multi-antenna, when the number of transmitting antennas is m and the number of receiving antennas is n, it may include performing m x n unit BFTs (e.g., SLS). In FIGS. 29 to 31, the corresponding operations may be omitted for representation purposes.

[0458] In the examples of FIGS. 27 to 29, descriptions that overlap with the example of FIG. 18 regarding the method of initiating BFT through a notice frame may be omitted.

[0459] For example, sAP can provide BFT schedule information along with information about a specific section in mAP's BSS through a notification frame.

[0460] mAPs belonging to the AP MLD are BFT initiators, and mSTA 1 belonging to non-AP MLD 1 and mSTA 2 belonging to non-AP MLD 2 may be responders. mAP and mSTA 1 may perform BFT 1 via BF frames on Link 2. mAP and mSTA 2 may perform BFT 2 via BF frames on Link 2. Link 1 may be in the sub-7 GHz band, and Link 2 may be in the millimeter wave (mmWave) band.

[0461] For example, through the AID11 field, an mAP (e.g., AID11=0) can be designated as the initiator to operate for I-TXSS and R-TXSS in the corresponding interval, and all STAs (e.g., AID11=2008 with broadcast AID) can be designated as the responders. Additionally, BFT 1 user-per-information can be scheduled to sSTA1 (or non-AP MLD 1) using AID11=11. Additionally, BFT 2 user-per-information can be scheduled to sSTA2 (or non-AP MLD 2) using AID11=12. The AID11 field may be replaced with AID12, AID7, or AID13, etc., according to the method described above in the present disclosure.

[0462] Common information may specify a schedule of BFT phase intervals that can be used commonly by mSTA1 and mSTA2, and per-user information may specify a BFT start time (e.g., SLS start time), BFT duration (e.g., SLS duration), etc., for each respondent. Assuming there are no BFT iterations, the BFT interval may be omitted or set to 0. If the BFT interval is omitted, the existence of the BFT interval may be indicated using an existence bitmap.

[0463] In addition, as shown in the example of Fig. 28, the BFT start time of the common information can be set as the ISS start for all STAs. In this case, one more BFT type can be defined. For example, by specifying the BFT type as Broadcast BFT-SLS-Initiator Broadcast (IBroadcast), the RSS for each responder may be performed after the ISS is preceded for all STAs.

[0464] Additionally, as shown in the example of FIG. 29, a BFT for a single link (e.g., individual BFT) can be performed by signaling only BFT user-per-user information. For example, an sSTA belonging to a non-AP MLD can transmit a BFT notification frame on Link 1 (e.g., sub-7 GHz) to an sAP belonging to an AP MLD. For example, in the BFT user-per-user information, the BFT type can be specified as BFT-SLS, and the initiator ID can be specified as 0 according to the mAP's AID11 value. Additionally, the BFT start time and BFT duration, etc., can be specified. The BFT interval can be set to 0 or omitted, assuming there is no periodic next BFT. If the BFT interval is omitted, the existence of the BFT interval can be indicated using an existence bitmap.

[0465] In FIGS. 27 through 29, the initiator is identified as AP MLD, but the initiator and responder may be designated, and the entity that transmitted the notice frame may be the initiator. Additionally, the entity that received the notice frame may be the initiator. The scope of the present disclosure is not limited thereto.

[0466] A method may be provided to provide information regarding BFT provided in the mmWave band in existing wireless LAN systems to the counterpart STA(s) via a notice frame in the sub-7GHz band. Accordingly, unsolicited BFT common information and / or BFT user-per-user information regarding the counterpart STA(s) may be provided in the sub-7GHz band, and control / management overhead for BFT in the mmWave band may be reduced.

[0467] 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.

[0468] 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.

[0469] 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.

[0470] 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 an announcement frame containing information about a beam-related procedure by a first station (STA) affiliated with a first multi-link device (MLD); and The step of transmitting the aforementioned notification frame to a second STA belonging to the second MLD at the first link by the aforementioned first STA, and A method in which a beam-related procedure is performed in a second link by a third STA belonging to the first MLD and a fourth STA belonging to the second MLD, based on information regarding the beam-related procedure above.

2. In Paragraph 1, A method comprising one or more of information regarding the above beam-related procedures, including common information common to the beam-related procedures or per-user information for each beam-related procedure.

3. In Paragraph 2, A broadcast beam-related procedure is performed based on at least one of the above common information, and A method in which an individual beam-related procedure is performed based on at least one of the above user-per-information.

4. In Paragraph 2, The above common information is included in a specific STA information field within the above notice frame, and A method in which a specific AID (association identifier) ​​value of the specific STA information field indicates that the common information is included in the specific STA information field.

5. In Paragraph 2, Based on the fact that the disambiguation subfield of the first STA information field within the above notice frame is set to 0, it indicates that the user-per-information is included in the second STA information field within the above notice frame, and A method in which a specific AID value of the second STA information field is the same as a specific AID value of the first STA information field.

6. In Paragraph 2, A method indicating that the user-per-information is included in the first STA information field based on the disambiguation subfield of the first STA information field within the above notice frame being set to 0.

7. In Paragraph 2, The value of a specific Nc (number of column) field of the first STA information field within the above notice frame indicates that the user-per-information is included in the second STA information field within the above notice frame, and A method in which a specific AID value of the second STA information field is the same as a specific AID value of the first STA information field.

8. In Paragraph 2, A method in which the value of a specific Nc field of a first STA information field within the above notice frame indicates that the user-per-information is included in the first STA information field.

9. In Paragraph 2, The user-per-information is included in the third STA information field within the above notice frame, and The specific AID value of the third STA information field is identical to the specific AID value of the first STA information field and the second STA information field within the aforementioned notice frame, and A method in which the third STA information field is placed after the first STA information field and the second STA information field.

10. In Paragraph 2, A method in which one or more of a type subfield or a subtype subfield indicates that one or more of the common information or the user-per-information is included in the notice frame.

11. In Paragraph 1, In the above beam-related procedure The above third STA is an initiator and the above fourth STA is a responder, or A method in which the third STA is the respondent and the fourth STA is the initiator.

12. In Paragraph 1, The beam-related procedure in the second link above: Beam-related procedures for one or more of the transmitting beam of the third STA or the receiving beam of the fourth STA; or A method comprising a beam-related procedure for one or more of the transmitting beam of the fourth STA or the receiving beam of the fourth STA.

13. In Paragraph 1, A method in which the first link is included in the sub-7 GHz band and the second link is included in the millimeter wave (mmWave) band.

14. In Paragraph 1, A method in which the above beam-related procedure includes one or more of a beam establishment procedure or a beam tracking procedure.

15. In Paragraph 1, A method in which the first MLD is an access point (AP) MLD and the second STA is a non-AP MLD.

16. In Paragraph 1, Information regarding the above beam-related procedures is: A method comprising one or more of the following: information about a start time, information about the number of transmission beams, information about the maximum value of the number of transmission beams, information about the number of transmission antennas, information about the maximum value of the number of transmission antennas, information about the number of reception antennas, information about the maximum value of the number of reception antennas, information about the reception beam establishment length, information about the maximum value of the reception beam establishment length, or information about the type of beam-related procedure.

17. 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 an announcement frame containing information about beam-related procedures; and In the first link, the above notice frame is configured to be transmitted through the one or more transceivers to a second STA affiliated with a second multi-link device (MLD), and Based on information regarding the beam-related procedure above, a 1st STA belonging to the 1st MLD, wherein a beam-related procedure is performed in the 2nd link by a 3rd STA belonging to the 1st MLD and a 4th STA belonging to the 2nd MLD.

18. A step of receiving an announcement frame containing information about a beam-related procedure in a first link from a first STA affiliated with a first MLD, by a second station (STA) affiliated with a second multi-link device (MLD); and By means of the second STA, the step of processing information regarding the beam-related procedure included in the aforementioned notice frame is included, and A method in which a beam-related procedure is performed in a second link by a third STA belonging to the first MLD and a fourth STA belonging to the second MLD, based on information regarding the beam-related procedure above.

19. 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: In the first link, receiving an announcement frame containing information about beam-related procedures from a first STA affiliated with a first multi-link device (MLD) via the one or more transceivers; and It is configured to process information regarding the beam-related procedures included in the above notice frame, and Based on information regarding the beam-related procedure above, a 2nd STA belonging to the 2nd MLD, wherein a beam-related procedure is performed in the 2nd link by a 3rd STA belonging to the 1st MLD and a 4th STA belonging to the 2nd MLD.

20. 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 16 based on execution by one or more processors.

21. One or more non-transitory computer-readable media storing one or more instructions that are executed by one or more processors to control the execution of a method according to any one of claims 1 through 16.

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