Method and device for transmitting or receiving aggregated-control field including various feedback information in wireless LAN system

Abstract

Disclosed are a method and device for transmitting or receiving an aggregated-control (A-control) field including various feedback information in a wireless LAN system. A method according to an aspect of the present disclosure may comprise the steps of: generating, by a first station (STA), a frame including an aggregated-control (A-control) field including a specific control subfield; and transmitting, by the first STA, a physical layer protocol data unit (PPDU) including the frame to a second STA. The specific control subfield may include one or more of multiple pieces of feedback information. The specific control subfield may further include information indicating whether each of the multiple pieces of feedback information is included.

Description

Method and device for transmitting or receiving a merge-control field including various feedback information in a wireless LAN system

[0001] The present disclosure relates to a method and apparatus for transmitting or receiving an aggregated-control (A-control) field containing various feedback information 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 transmitting or receiving an aggregated-control (A-control) field containing various feedback information in a wireless LAN system.

[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 a frame by a first station (STA) that includes a merge-control (A-control) field including a specific control subfield; and transmitting a physical layer protocol data unit (PPDU) including the frame by the first STA to a second STA. The specific control subfield may include one or more of multiple feedback information. The specific control subfield may further include information indicating whether each of the multiple feedback information is included.

[0007] A method according to a further aspect of the present disclosure may include: receiving a physical layer protocol data unit (PPDU) containing a frame from a first STA by a second station (STA); and obtaining one or more of multiple feedback information in a specific control subfield of a merge-control (A-control) field included in the frame. The specific control subfield may include information indicating whether each of the multiple feedback information is included.

[0008] According to the present disclosure, a method and apparatus for a feedback information response based on a trigger frame in a wireless LAN system may be provided.

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

[0019] FIG. 9 is a drawing for explaining an example of the operation of a first STA according to the present disclosure.

[0020] FIG. 10 is a drawing for illustrating an example of the operation of the second STA according to the present disclosure.

[0021] FIG. 11 is a drawing showing examples of the configuration of common control / feature information according to the present disclosure.

[0022] FIG. 12 shows additional examples of IDC information fields according to the present disclosure.

[0023] FIG. 13 is a diagram illustrating an example of feedback information transmission using an A-control field according to the present disclosure.

[0024] FIG. 14 is a diagram illustrating another example of feedback information transmission using an A-control field according to the present disclosure.

[0025] FIG. 15 is a diagram showing another example of feedback information transmission using an A-control field according to the present disclosure.

[0026] FIG. 16 is a diagram showing an example of an A-control field including various feedback information for multi-link operation according to the present disclosure.

[0027] FIG. 17 illustrates an example of transmitting feedback information using an A-control field when the AP according to the present disclosure is a TXOP holder.

[0028] FIG. 18 illustrates an example of transmitting feedback information using an A-control field when the STA according to the present disclosure is a TXOP holder.

[0029] FIG. 19 is a drawing showing examples of A-control fields including various feedback information according to the present disclosure.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] The following describes the technical features to which the examples of the present disclosure may be applied.

[0037] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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).

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] FIG. 2 is a drawing showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0051] 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.

[0052] 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.

[0053] 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).

[0054] 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.

[0055] 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.

[0056] 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).

[0057] 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.

[0058] 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.

[0059] In addition to the structure of the aforementioned DS, an Extended Service Set (ESS) may be configured to provide wider coverage.

[0060] 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.

[0061] 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.

[0062] FIG. 3 is a diagram illustrating a link setup process to which the present disclosure can be applied.

[0063] 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.

[0064] 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.

[0065] 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).

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] FIG. 4 is a drawing illustrating a backoff process to which the present disclosure may be applied.

[0076] 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.

[0077] 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).

[0078] 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, ...).

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] FIG. 5 is a diagram illustrating a CSMA / CA-based frame transmission operation to which the present disclosure may be applied.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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).

[0101] FIG. 7 is a drawing illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure may be applied.

[0102] 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)).

[0103] 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).

[0104] 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)).

[0105] An example of the HE PPDU format (IEEE 802.11ax) includes the RL-SIG (Repeated L-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), and PE (Packet Extension) fields in addition to the basic PPDU format (Fig. 7(d)). Depending on specific examples of the HE PPDU format, some fields may be excluded or their lengths may vary. For example, the HE-SIG-B field is included in the HE PPDU format for multiple users (MU), but is not included in the HE PPDU format for single users (SU). Additionally, the HE trigger-based (TB) PPDU format does not include HE-SIG-B, and the length of the HE-STF field may vary to 8 microseconds (us). The HE ER (Extended Range) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may vary to 16us. 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields can be 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.).

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.).

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] FIG. 8 is a drawing showing an exemplary format of a trigger frame to which the present disclosure can be applied.

[0132] A trigger frame may allocate resources for one or more TB PPDU transmissions and request TB PPDU transmissions. The trigger frame may also include other information required by an STA that transmits a TB PPDU in response. The trigger frame may include common info and user info list fields in the frame body.

[0133] The common information field may include information that applies commonly to one or more TB PPDU transmissions requested by a trigger frame, such as trigger type, UL length, whether a subsequent trigger frame exists (e.g., More TF), whether a CS (channel sensing) is required, UL BW (bandwidth), etc. FIG. 8 illustrates an exemplary format for the EHT variant common information field.

[0134] The 4-bit trigger type subfield can have values ​​from 0 to 15. Among these, the values ​​0, 1, 2, 3, 4, 5, 6, and 7 of the trigger type subfield are defined to correspond to basic, BFRP (Beamforming Report Poll), MU-BAR (multi-user-block acknowledgement request), MU-RTS (multi-user-request to send), BSRP (Buffer Status Report Poll), GCR (groupcast with retries) MU-BAR, BQRP (Bandwidth Query Report Poll), and NFRP (NDP Feedback Report Poll), respectively, and the values ​​8 to 15 are defined as reserved.

[0135] Among the common information, the trigger-dependent common info subfield may include information that is optionally included based on the trigger type.

[0136] A special user info field may be included within the trigger frame. The special user info field does not contain user-specific information, but rather contains extended common information not provided in the common information field.

[0137] The user information list contains zero or more user info fields. Figure 8 illustrates an exemplary EHT variant user info field format.

[0138] The AID12 subfield basically indicates that it is a user information field for the STA with the corresponding AID. Additionally, if the AID12 field has a specific predetermined value, it may be utilized for other purposes, such as assigning a Random Access (RA)-RU or being configured as a special user info field. A special user info field is a user information field that does not contain user-specific information but includes extended common information not provided in the common information field. For example, a special user info field can be identified by an AID12 value of 2007, and a special user info field flag subfield within the common information field can indicate whether the special user info field is included.

[0139] The RU allocation subfield can indicate the size and location of the RU / MRU. To this end, the RU allocation subfield may be interpreted together with the PS160 (primary / secondary 160MHz) subfield of the user information field, the UL BW subfield of the common information field, etc.

[0140] For example, as shown in Table 1 below, the mapping of B7-B1 of the RU allocation subfield can be defined along with the settings of B0 and PS160 of the RU allocation subfield. Table 1 shows an example of the encoding of the PS160 subfield and the RU allocation subfield of the EHT variant user information field.

[0141]

[0142]

[0143]

[0144] If B0 of the RU allocation subfield is set to 0, it indicates that the RU / MRU allocation is applied to the primary 80MHz channel, and if the value is set to 1, it indicates that the RU allocation is applied to the secondary 80MHz channel of the primary 160MHz. If B0 of the RU allocation subfield is set to 0, it indicates that the RU / MRU allocation is applied to the lower 80MHz of the secondary 160MHz, and if the value is set to 1, it indicates that the RU allocation is applied to the upper 80MHz of the secondary 160MHz.

[0145] In the trigger frame RU allocation table of Table 1, the parameter N can be calculated based on the formula N=2*X1+X0. For bandwidths of 80 MHz or less, the values ​​of PS160, B0, X0, and X1 can be set to 0. For 160 MHz and 320 MHz bandwidths, the values ​​of PS160, B0, X0, and X1 can be set as shown in Table 2. These settings represent the absolute frequency order for the primary and secondary 80 MHz and 160 MHz channels. The order from left to right indicates the order from lowest to highest frequency. The primary 80 MHz channel is designated as P80, the secondary 80 MHz channel as S80, and the secondary 160 MHz channel as S160.

[0146]

[0147] Merge-control (A-control) field

[0148] As described with reference to FIG. 6, the HT control field may be included in the MAC header. The HT control field is present in the control wrapper frame and may be present in the QoS Data, QoS Null, and management frames as determined by the +HTC subfield of the frame control field.

[0149] The HT control field can have a format like Table 3.

[0150]

[0151] As shown in Table 3, the HE variant HT control field may include an A(aggregated)-control subfield. The A-control subfield may have a length of 30 bits.

[0152] The A-control subfield may include a control list subfield of variable length and a padding subfield of 0 bits or more. The control list subfield may include one or more control subfields. The padding subfield may be set to a sequence of zero values ​​such that the length of the A-control subfield included in the HT control field is 30, which follows the last control subfield (if present).

[0153] One control subfield may include a 4-bit control ID subfield and a control information subfield of variable length.

[0154] The control ID subfield may indicate the type of information included in the control information subfield. The length of the control information subfield may be defined as a fixed value for each value of the control ID subfield (excluding reserved values). The values ​​of the control ID subfield and the lengths of the control information subfields associated therewith may be defined as shown in Table 4.

[0155] Control ID value meaning0TRS(Triggered response scheduling)1OM(Operating mode)2HLA(HE link adaptation) / ELA(EHT link adaptation)3BSR(Buffer status report)4UPH(UL power headroom)5BQR(Bandwidth query report)6CAS(Command and status)7EHT OM(EHT operating mode)8SRS(Single response scheduling)9AAR(AP assistance) request)10-14Reserved15ONES(Ones need expansion surely)

[0156] A merge-control (A-control) field containing various feedback information

[0157] In-device coexistence (IDC) information can also be referred to as unavailability information and may include information regarding time intervals during which a device cannot perform transmission or reception. By transmitting this IDC information to other STA(s) in advance, unnecessary media access, such as data loss, recovery procedures, and retransmissions caused by the IDC situation, can be prevented.

[0158] Similar to IDC information, when information related to the operation of an STA is provided to other STA(s), various types of information may exist that can efficiently manage the channel access operations of the STAs. For example, various functions such as IDC (in-device coexistence), DPS (dynamic power saving), MAP (multi-AP), NPCA (non-primary channel access), and security enhancement are being considered to expand the functionality of wireless LAN systems. To support this, ICF (initial control frame), ICR (initial control response), and CRF (control response frame) may be defined. To implement this, it may be required to define the expansion / modification of existing trigger frames and response frames, as well as new frame exchange processes.

[0159] In the various examples of the present disclosure described below, the entity transmitting a frame containing various feedback information (e.g., a first STA) may be an AP or a non-AP STA. Additionally, the entity receiving the various feedback frame (e.g., a second STA) may be an AP or a non-AP STA. Furthermore, the exchange of various feedback information between the first STA and the second STA may be performed between an AP and an AP, or between a non-AP STA and an AP, or between an AP and a non-AP STA, or between a non-AP STA and a non-AP STA.

[0160] FIG. 9 is a drawing for explaining an example of the operation of a first STA according to the present disclosure.

[0161] In step S910, the first STA can generate a frame containing a merge-control (A-control) field containing a specific control subfield containing one or more of multiple feedback information.

[0162] In some examples, a specific control subfield may include information indicating whether each of the multiple feedback information is included.

[0163] In some examples, information indicating whether each of the multiple feedback information is included may correspond to multiple existence fields. In this case, the number of multiple existence fields may be equal to the number of multiple feedback information, and these multiple existence fields may also be referred to as existence bitmaps.

[0164] In some examples, information indicating whether each of the multiple feedback information is included may correspond to a type field. In this case, a specific control subfield includes one or more type fields, and one or more of the multiple feedback information included in the specific control subfield may correspond to one or more type fields. For example, a first value of a type field may correspond to first feedback information, and a second value of a type field may correspond to second feedback information.

[0165] In some examples, a specific control subfield may include minimum information among the first feedback information and minimum information among the second feedback information.

[0166] In some examples, the first feedback information may include one or more fields, and the second feedback information may include one or more fields.

[0167] In some examples, the first feedback information corresponds to the first operation mode, and the second feedback information may correspond to the second operation mode.

[0168] In some examples, multiple feedback information may include two or more of unavailability-related feedback information, dynamic power saving (DPS)-related feedback information, non-primary channel access (NPCA)-related feedback information, or low latency traffic (LLT)-related feedback information.

[0169] In some examples, a specific control subfield may include a control ID field set to a single control identifier (ID) value. Here, the single control identifier value may be common to multiple feedback information.

[0170] For example, within a specific control subfield having a single control identifier value, existence fields corresponding to multiple feedback information may be included, and feedback information(s) indicated as existing in each of the existence fields may be included.

[0171] For example, within a specific control subfield having a single control identifier value, one or more feedback information distinguished based on the value of a type field may be included.

[0172] For example, within a specific control subfield having a single control identifier value, one or more feedback information distinguished based on the sub-control identifier value may be included.

[0173] In step S920, the first STA may transmit a PPDU containing the generated frame to the second STA.

[0174] The method described in the example of FIG. 9 may be performed by the first device (100) of FIG. 1. For example, one or more processors (102) of the first device (100) of FIG. 1 may be configured to generate a frame including an A-control field including a specific control subfield containing one or more of multiple feedback information, and to transmit a PPDU containing the frame to a second STA 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. 9 or the examples described below when executed by one or more processors (102).

[0175] For example, the memory (104) may store information related to the various feedback information according to the present disclosure. Based on the information stored in the memory (104), the processor (102) may generate a frame containing an A-control field containing various feedback information, generate various RUs, 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 perform the operation of a first STA according to an example of the present disclosure. For example, the processor (102) may be configured to generate an A-control field related to various feedback information, generate a frame / PPDU containing the said field, and transmit it through the transceiver (106).

[0176] FIG. 10 is a drawing for illustrating an example of the operation of the second STA according to the present disclosure.

[0177] In step S1010, the second STA can receive a PPDU containing a frame from the first STA.

[0178] In step S1020, the second STA can obtain one or more of multiple feedback information from a specific control subfield of the A-control field included in the frame.

[0179] In the example of FIG. 10, the detailed examples of the multiple feedback information included in the specific control subfield of the A-control field and the format of the specific control subfield are the same as those in FIG. 9, so redundant descriptions are omitted.

[0180] The method described in the example of FIG. 10 can 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 PPDU containing a frame from the first STA through one or more transceivers (206) and to obtain one or more of multiple feedback information in a specific control subfield of the A-control field included in the 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. 10 or the examples described below when executed by one or more processors (202).

[0181] For example, the memory (204) may store various feedback information 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). Additionally, the processor (202) can be configured to obtain various feedback information from the A-control field within the frame (e.g., QoS data frame, QoS null frame, management frame, etc.) included in the MAC PDU and to perform operations accordingly.For example, the processor (202) of the receiving device may be configured to perform the operation of the second STA according to the example of the present disclosure. For example, the processor (202) may obtain IDC information in the A-control field within the frame included in the MPDU received from the first STA, obtain information regarding transmission status and / or transmission capability in the IDC section of the first STA or the third STA belonging to the same MLD as the first STA, and determine transmission / reception status in the IDC section based thereon.

[0182] In the examples of FIGS. 9 and 10, the first STA may generate a frame containing multiple feedback information (e.g., unavailability-related feedback information (e.g., IDC-related information), LLT-related feedback information, BSR-related feedback information)) and a field containing information indicating whether each of the multiple feedback information is included, and transmit it to the second STA via a PPDU. For example, it may include an ID indicating that it is specific feedback information, or it may include information indicating the number of feedback information while multiple feedback information is included consecutively.

[0183] For example, a frame transmitted by the first STA may be a QoS data frame, a QoS null frame, or a management frame. This frame may be transmitted as a response frame to another frame (e.g., a trigger frame), or it may be a frame transmitted unsolicited.

[0184] For example, a frame transmitted by the first STA may include multi-link information. Multi-link (ML) information may be a link ID and / or a link ID bitmap. For example, if the first STA transmits feedback information regarding the unavailability (or IDC) of the second STA, the feedback information regarding the unavailability (or IDC) included in the frame transmitted by the first STA may correspond to information regarding the second STA rather than information regarding the first STA.

[0185] The examples of FIGS. 9 and 10 may correspond to some of the various examples of the present disclosure. Hereinafter, various examples of the present disclosure including the examples of FIGS. 9 and 10 will be described in more detail.

[0186] In the following examples, various methods are described for including feedback information in a response frame (e.g., a multi-TA block ACK frame) petitioned by a trigger frame (e.g., a BSRP trigger frame) or in a frame transmitted without petitioning. The BSRP trigger frame and the multi-STA block ACK frame are merely exemplary, and the examples of the present disclosure may also apply to trigger frames of other formats (or an ICF used at the start of a TXOP, or a control request frame used after the start of a TXOP) and / or response frames of other formats (or an ICR responding to an ICF, or a control response frame responding to a control request frame), or any frame that can be transmitted without petitioning.

[0187] Example 1

[0188] The present embodiment relates to control information (or feature information or feedback information). The control information may be included in a trigger frame and / or in a response frame. For example, the control information may include in-device coexistence (IDC) information, low latency traffic (LLT) information, buffer status report (BSR) information, etc.

[0189] The solicited information included in the trigger frame may correspond to information specifying the feedback information to be included in the response frame.

[0190] Common control information can also be referred to as common feature information.

[0191] Common control / feature information may correspond to control information for each feature, delivered information (e.g., feedback information included in a trigger frame), and / or feedback information included in a response frame (in response to petition information in a trigger frame).

[0192] Common control / feature information may include information related to IDC, MAP (multi-AP), DPS (dynamic power saving), NPCA (non-primary channel access), security enhancement, etc., and / or information about A-control (e.g., BSR).

[0193] FIG. 11 is a drawing showing examples of the configuration of common control / feature information according to the present disclosure.

[0194] Example 1-1

[0195] As shown in the example of FIG. 11(a), common control / feature information may include a length field and a presence bitmap field.

[0196] The length field may be replaced by the information count field. Alternatively, the length (information count) field may be omitted.

[0197] The existence bitmap field may include a bitmap of a length corresponding to the number of supported features such as MAP, DPS, IDC, NPCA, BSR, etc. Each bit position of the bitmap may indicate whether the corresponding control information is included. Whether one or more control information is included may be indicated by the bitmap.

[0198] Information about features corresponding to bit positions set to a specific value (e.g., 1) in the existing bitmap may be further included. For example, the value of n may correspond to the number of values ​​of 1 in the existing bitmap.

[0199] In the example of FIG. 11(a), if the MAP control / feature information is not present in the existing bitmap, but control / feature information for NDCA, DPS, IDC, and BSR is present, four control / feature information fields follow, and each control / feature information field may include subfield(s). In the example, the specific details of the IDC control information will be described later with reference to FIG. 12.

[0200] Examples 1-2

[0201] As shown in the example of FIG. 11(b), common control / feature information may include a length field and an ID field.

[0202] The length field may be replaced by the information count field. Alternatively, the length may be expressed as the number of octets or the number of specific units (e.g., 2-bit units, 4-bit units, ...). Alternatively, the length field may be omitted depending on feature indications such as petition information (e.g., feature enable or feature disable). Alternatively, the length field may be omitted if the length of each control information is fixed and non-variable.

[0203] The ID field can be set to an identifier value defined for each feature. For example, the ID value of MAP is 1, the ID value of DPS is 2, the ID value of IDC is 3, and the ID value of NPCA is 4, so that each feature can be distinguished by its ID value.

[0204] The combination of the ID field and the corresponding control information (and / or feature information) may include one or more.

[0205] Examples 1-3

[0206] As shown in the example of FIG. 11(c), common control / feature information may include a total length field, an ID field, a length field by ID, and a feature information field. For example, in the example of FIG. 11(b), a length field by ID may be added. The first length field corresponds to the total length field, and the length field following the ID field may correspond to the length field for the feature information of that ID.

[0207] Example 2

[0208] This embodiment describes examples of feature information of common control information.

[0209] Example 2-1

[0210] IDC-related information may be included as one exemplary feature information of common control information. The IDC-related information may include one or more of the information described below.

[0211] IDC start time

[0212] IDC start time (ST) information may correspond to a value indicating the time interval from the current time to the time when the IDC SP starts, based on a predetermined unit (e.g., microseconds (ms), TSF (timing synchronization function), partial TSF, etc.).

[0213] IDC ST information can indicate the point in time when IDC occurs, that is, the point in time when unavailability occurs.

[0214] Unavailability may mean that the STA is unavailable for the channel on which the STA is operating or for some subchannels of the channel on which the STA is operating (e.g., X 20 MHz subchannels). That is, it may not always mean that the STA is unavailable for the channel on which the STA is operating.

[0215] IDC ST information may be indicated using the full (e.g., the full 8-octet length information) or partial (e.g., partial TSF) value of the timestamp (or TSF) received from the AP or the AP itself. For example, in the case of partial TSF, similar to existing broadcast TWTs, bit values ​​(or bit positions) of X octets (e.g., 2 octets) may be used starting from a specific bit value (or bit position) of the TSF.

[0216] For example, the interval or duration value (e.g., in microseconds) from the start or completion of transmission of the frame currently transmitting IDC ST information to the point where IDC or unavailability occurs may be indicated as IDC ST information.

[0217] Alternatively, the IDC ST may be indicated using the duration field of the MAC header. For example, the value of the duration field in the MAC header may be set to a value corresponding to the time interval or duration up to the IDC ST. In this case, when the IDC ST is indicated via the duration field of the MAC header, the start time information may be omitted from the IDC-related information (e.g., the individual IDC TWT parameter set).

[0218] Alternatively, the IDC ST may indicate the start time of an availability period where no unavailability caused by the IDC occurs.

[0219] IDC duration

[0220] IDC duration information may correspond to the time during which the IDC lasts. For example, the unit of duration may be microseconds or other units may be applied. Depending on the application to which the IDC SP is applied, the size of the duration information may be defined as smaller than 8 octets (e.g., 2 octets).

[0221] For example, information regarding a specific unit size may be included along with the duration information. For example, information indicating 1us, 8us, 32us, or 64us as the unit size may be included, and this may be applied as the unit of the value indicated in the duration information. For example, if the value of the duration information is 1000 and the unit size information indicates 1us, 1ms may be indicated as the duration of the IDC SP. For example, if the value of the duration information is 1000 and the unit size information indicates 8us, 8ms may be indicated as the duration of the IDC SP.

[0222] For example, IDC duration information may be defined as a size of 2 octets, such as the duration field of the MAC header, and the size is merely illustrative and may have a smaller or larger size.

[0223] For example, if an IDC ST exists, the indication of the IDC duration may be omitted. In this case, the IDC duration may be implicitly interpreted as from the IDC ST to the end of a specific period. For example, if an IDC ST is indicated within a TXOP, the end of the specific period may correspond to the end of the TXOP.

[0224] Alternatively, if the IDC ST indicates the start time of the availability period, the IDC duration may indicate the duration of that availability period.

[0225] IDC interval

[0226] IDC interval information may correspond to the time interval between repetitions of an IDC SP when the IDC SP is repeated periodically. For example, the unit of the interval may be microseconds or other units may be applied. Depending on the application to which the IDC SP is applied, the size of the interval information may be defined as smaller than 3 octets (e.g., 2 octets).

[0227] For example, information regarding a specific unit size may be included along with the interval information. For example, information indicating 1us, 8us, 32us, or 64us as the unit size may be included, and this may be applied as the unit of the value indicated in the interval information. For example, if the value of the interval information is 1000 and the unit size information indicates 1us, 1ms may be indicated as the interval between repeating IDC SPs. For example, if the value of the interval information is 1000 and the unit size information indicates 8us, 8ms may be indicated as the interval between repeating IDC SPs.

[0228] For example, IDC interval information may be defined as a size of 2 octets, such as the duration field of the MAC header, and the size is merely illustrative and may have a smaller or larger size.

[0229] IDC continuity

[0230] IDC continuity information can indicate how long an IDC SP lasts. For example, the number of IDC SP iterations (e.g., an integer value) can be indicated as IDC continuity information.

[0231] Additionally or alternatively, as IDC continuity information, the total duration including all IDC SP iterations from the start time of the IDC SP (i.e., the duration until the IDC SP iterations end, not the duration of a single IDC SP) or the end time of the IDC SP iterations (i.e., the time when the IDC SP iterations end, not the end time of a single IDC SP) may be indicated.

[0232] Alternatively, as IDC continuity information, the number of beacon frames, TBTT, beacon interval, etc., may be indicated. For example, the number of times a beacon is transmitted within the period during which the repetition continues from the time the IDC SP first occurs / starts may be indicated. Alternatively, the number of beacon intervals for which the repetition of the IDC SP continues in units of beacon intervals from the time the IDC SP first occurs / starts may be indicated.

[0233] This IDC continuity information can be included in the IDC information when an IDC interval exists (i.e., when a predetermined interval exists between iterations of the IDC SP).

[0234] IDC Channel / BW (bandwidth)

[0235] IDC channel / BW (bandwidth) information can indicate the channel / BW where IDC occurs. In other words, channel / BW information can indicate the frequency resources where IDC SP occurs or does not occur.

[0236] For example, IDC channel / BW information can be defined in a bitmap format. For example, for the operating channel and / or bandwidth of an STA, a bitmap is defined in units of 20 MHz (sub)channels, and whether each 20 MHz (sub)channel is available or not due to an IDC event can be indicated through the value of each bit position of the bitmap.

[0237] Additionally or alternatively, since the BW of each STA may be different, additional BW information may be indicated. For example, the BW may be indicated as one of 20 MHz / 40 MHz / 80 MHz / 160 MHz / 320 MHz, and a bitmap having a number of bits corresponding to the number of 20 MHz (sub)channels corresponding to the indicated BW may be adaptively configured.

[0238] IDC channel / BW information may indicate a limited BW that the STA can transmit and receive (i.e., available) due to IDC conditions, and in this case, information about the IDC channel may not be included in the IDC-related information.

[0239] IDC NSS (number of spatial streams) / antenna

[0240] IDC NSS (number of spatial streams) / antenna information may include information indicating available (or unavailable) NSS and / or available (or unavailable) antenna indices.

[0241] For example, the available NSS information can indicate the number of available space streams. Depending on the value of the available NSS information, the number of space streams available even in IDC situations can be indicated, excluding space streams that are unavailable due to IDC events or IDC situations.

[0242] For example, available NSS information may indicate available or unavailable NSS and / or antenna indices in an IDC context. For instance, using a bitmap, the availability or unavailability of each antenna may be indicated bit by bit, starting from the lowest (or highest) antenna index in order, based on the MSB (most significant bit) or LSB (least significant bit) of the information.

[0243] Example 2-2

[0244] Whether the information / fields / subfields of the various examples mentioned above are included in IDC-related information may vary depending on the situation. For example, if the primary channel of the BSS to which the STA belongs is affected by an IDC event, the STA may be unable to use all channels within the BSS due to the IDC operation; therefore, IDC channel / BW information indicating specific frequency resources may not be included in the IDC-related information. Alternatively, if the IDC SP occurs only once temporarily rather than periodically, IDC interval information and IDC continuity information may not be included in the IDC-related information. Accordingly, various methods described below may be applied to indicate whether specific information / fields / subfields are included in (or exist in) the IDC-related information.

[0245] FIG. 12 shows additional examples of IDC information fields according to the present disclosure.

[0246] For example, a presence field can be defined and used for each piece of information / field / subfield. If the value of the presence field for specific information is 1, that specific information exists, and if the value is 0, that specific information does not exist.

[0247] The existence field may be defined in the form of a bitmap. As in the example of FIG. 12(a), it can be assumed that the first bit of the existence bitmap corresponds to IDC start time information, the second bit corresponds to IDC duration information, and the third information corresponds to IDC channel information. When the existence bitmap is set to 110xxxxx, the IDC information may include the IDC start time field and the IDC duration field, but may not include the IDC channel field. The remaining bits in the existence bitmap, excluding the number of bits corresponding to each piece of information, may be reserved.

[0248] Next, the 1-bit fully unavalability field in the examples of FIG. 12 may indicate whether the STA can transmit or receive on the operating channel due to the IDC. For example, if the value is 1, information about the IDC channel may not be included.

[0249] Next, a 1-bit indicator field may be defined and used to indicate periodicity. If the IDC SP is repeated continuously with periodicity, the value of the periodicity field may be set to 1. If the IDC SP is generated only once, the value of the periodicity field may be set to 0. In this case, the IDC interval information and IDC continuity information may not be included in the IDC-related information.

[0250] In the example of FIG. 12(b), when the value of the total unavailable field is 0, it is partially unavailable (or partially available), so information such as the IDC channel may be included. Also, when the value of the periodicity field is 0, it corresponds to a non-repeating IDC SP, so the IDC start time and IDC duration fields are included, but the IDC interval and IDC continuity fields may not be included.

[0251] In the example of FIG. 12(c), a length field may be added to the IDC information field. When a new subfield is added to the IDC information, the STA that cannot recognize the new subfield can determine which field at which location can be ignored based on the value of the length field.

[0252] Additionally or alternatively, an ID may be assigned to the IDC information field. This is intended to explicitly indicate that the field is an IDC information field, and the STA may recognize other ID values ​​as control information for that ID rather than the IDC information field. Such an ID field may correspond to a control information field (which may contain an IDC information field).

[0253] As shown in the example of FIG. 12(d), a generalized control information field may contain one or more types of control information. For example, the generalized control information field may contain the same types of control information or different types of control information. For example, an IDC information field and other information fields may be included within the generalized control information field. The first field of the generalized control information field may indicate the number of control information items, and for example, it may be assumed that two types of control information are included. It is assumed that an ID value of 0 is assigned to the IDC information field and an ID value of 1 is assigned to the BSR (buffer status report) information field. Thus, an IDC information field containing an ID field set to a value of 0, and a BSR information field containing an ID field set to a value of 1 may be included within the generalized control information field.

[0254] Alternatively, in the example of FIG. 12(d), the number field of control information may be omitted. Or, the number field of control information may be configured in the form of an element that includes a length field.

[0255] Examples 2-3

[0256] Other information that may be included in control information or feature information, other than the aforementioned IDC-related information, is explained below.

[0257] LLT (low latency traffic) information

[0258] LLT information may be defined for the purpose of notifying the TXOP holder when low latency traffic (LLT) occurs from the TXOP responder. The TXOP holder, upon receiving LLT information as feedback information, may provide various methods (e.g., TXOP sharing, trigger-based MU data transmission, etc.) to enable the TXOP responder to transmit the LLT. LLT information is not limited to information transmitted by the TXOP responder to the TXOP holder, but may also be applied to notify other STAs of the occurrence of an LLT by any STA.

[0259] LLT information may be defined as a 1-bit indicator that can indicate whether an LLT has occurred. Alternatively, LLT information may be defined as an appropriate size of more than 1 bit to indicate various additional information such as LLT range (e.g., transmission lifetime) requirements, LLT frame size, and type of LLT information.

[0260] BSR Information

[0261] BSR (buffer status report) information can be defined to provide existing BSR information as control / feedback information. This can be distinguished from the existing method where a BSRP trigger frame petitions a QoS null frame containing BSR information in the A-Control field. For example, when a BSRP trigger frame is used as a trigger frame during an ICF or TXOP, BSR information can be defined as a type of control / feedback information to provide BSR information for a response to the BSRP along with other control / feedback information.

[0262] BSR information may include information included in the existing BSR (e.g., access category index (ACI) bitmap, delta TID (traffic identifier), ACI high, scaling factor, queue size high, and / or queue size all), and may additionally include BSR extension information. BSR extension information may include, for example, an unscaled value of the TID for reporting a larger queue size, multiple TIDs, and additional control subfields for reporting a queue size larger than the maximum queue size that the QoS control frame can report when the same TID does not exist in the MPDU.

[0263] Cross-link power saving information

[0264] Cross-link power save information may correspond to information indicating the entry / exit of power saving mode for the entire link.

[0265] In the power management of a conventional multi-link device (MLD), the entry / exit of power saving mode can be indicated by setting the value of the power management (PM) subfield of the MAC header of a frame that can be transmitted on each link (i.e., per link) to 1 or 0. Even when all STAs affiliated with the MLD enter / exit power saving mode, control / feedback information indicating the entry / exit of power saving mode across the entire link can be defined to eliminate the overhead of indicating the entry / exit of power saving mode through the value of the PM subfield of the frame transmitted on each link.

[0266] Power management information, such as cross-link power saving information, may include a link ID, a PM bit per link, and power saving scheduling information (e.g., time and / or duration) as information for each link. Alternatively, the link IDs may be configured as a bitmap, and a PM bit may be indicated for each link(s) corresponding to PM enable (e.g., indicated by 1) in the bitmap. In this case, scheduling information may be additionally listed in order only for the link(s) corresponding to PM enable in the bitmap.

[0267] Alternatively, a bitmap of link IDs may be additionally specified along with the existing PM subfield. In this case, the value specified by the PM subfield may be applied commonly to the link(s) corresponding to PM enable in the bitmap (e.g., indicated by 1). For example, if the link IDs at the 3rd and 6th bit positions of the bitmap are set to 1, the value of the PM subfield may be applied commonly to link IDs 3 and 6.

[0268] In the examples described above, common control / feature information may include control information that is commonly applied for each function. Multiple common control / feature information may be included in a single container (e.g., a frame / element).

[0269] Example 3

[0270] This embodiment relates to a method for including various feedback information within a combined-control (A-control) field.

[0271] Information regarding existence bitmaps, sequential listing, ID, length, count, etc., which are various examples indicating whether the IDC-related information fields of FIG. 12 described above are included, can be extended and applied to various feedback information other than IDC-related information. In the examples described below, the A-control field may include various feedback information (or feature-related information, or operation mode-related information) in addition to IDC-related information.

[0272] FIG. 13 is a diagram illustrating an example of feedback information transmission using an A-control field according to the present disclosure.

[0273] AP can acquire a TXOP through the exchange of the AP's MU-RTS trigger frame (TF) and CTS from the STAs. In response to the basic TF transmitted by the AP, which is the TXOP holder, the TXOP responders STA1, STA2, and STA3 can transmit QoS data frames on their respective assigned RUs. The QoS data frames may include an A-control field, and the A-control field may include various feedback information. When an immediate ACK policy is applied to the ACK information for the QoS data frames, a block ACK (BA) frame may be transmitted after SIFS from the end of the QoS data frames.

[0274] For example, STA1 and STA3, who know that an IDC event will occur, may transmit by including IDC information in the A-control field of a QoS data frame or by including control information (or feedback information) that may include IDC information. Based on the feedback information included in the A-control field of the QoS data frame from STA1, the AP can know the start time, duration, etc. of STA1's IDC event, and based on the feedback information included in the A-control field of the QoS data frame from STA3, the AP can know the start time, duration, etc. of STA3's IDC event. If STA1's IDC event overlaps with the transmission of a BA frame, the AP may transmit a BA frame that does not include ACK information to be responded to by STA1 (or includes ACK information for STA2 and STA3), or may not transmit a BA frame that includes an ACK to be responded to by STA1. Alternatively, STA1 may set an ACK policy other than an ACK policy that requires an immediate ACK when transmitting a QoS data frame (e.g., BA), such as a delayed ACK policy.

[0275] FIG. 14 is a diagram illustrating another example of feedback information transmission using an A-control field according to the present disclosure.

[0276] In response to a BSRP TF transmitted from the AP that is the TXOP holder, the TXOP responders STA1, STA2, and STA3 may transmit QoS null frames on their respective assigned RUs. The QoS null frames may include an A-control field, and the A-control field may include various feedback information. For example, when an STA transmits a QoS null frame in response to a BSRP TF, it may transmit BSR-related information in addition to IDC-related information within the QoS null frame. For QoS null frames, the transmission of ACK information may be required immediately, or it may not be required immediately.

[0277] For example, STA2 and STA3, who know that an IDC event will occur, may transmit a QoS null frame containing IDC information in the A-control field or control information (or feedback information) that may contain IDC information. Based on the feedback information included in the A-control field of the QoS null frame from STA2, the AP can determine the start time, duration, etc. of STA2's IDC event, and based on the feedback information included in the A-control field of the QoS null frame from STA3, the AP can determine the start time, duration, etc. of STA3's IDC event. The AP may not transmit frames to STA2 and STA3 where the IDC event will occur, but may transmit downlink data to STA1 or transmit a basic trigger frame requesting uplink data transmission.

[0278] FIG. 15 is a diagram showing another example of feedback information transmission using an A-control field according to the present disclosure.

[0279] By transmitting an RTS frame and receiving a CTS from the AP, the STA can acquire a TXOP. The STA, as the TXOP holder, can transmit a QoS data frame (or QoS null frame), and the A-control field of the QoS data frame (or QoS null frame) may contain various feedback information. If an immediate ACK policy is set for the QoS data (or null) frame, a BA frame may be transmitted from the AP after a SIFS time from the QoS data (or null) frame.

[0280] For example, if the STA knows that an IDC event will occur, the STA may transmit by including IDC information in the A-control field of a QoS data (or null) frame or by including control information (or feedback information) that may contain IDC information, and accordingly, the AP can know the start time, duration, etc. of the STA's IDC event. In this case, the AP may not transmit a frame to the STA or trigger the transmission of a frame from the STA during the STA's IDC event period.

[0281] Example 4

[0282] This embodiment relates to the transmission / reception of feedback information in multi-link operation.

[0283] Regarding IDC-related information among the feedback information, if a TXOP is not acquired when an IDC event occurs at the first link, IDC-related information for the first link may not be transmitted. In this case, information related to the IDC event of the first link may be transmitted / received through the second link instead of the first link.

[0284] FIG. 16 is a diagram showing an example of an A-control field including various feedback information for multi-link operation according to the present disclosure.

[0285] STA1 and STA2 are non-AP STAs affiliated with a non-AP MLD, and AP1 and AP2 may correspond to AP STAs affiliated with an AP MLD. STA1 and AP1 may operate on Link 1, and STA2 and AP2 may operate on Link 2.

[0286] STA1, a TXOP holder who has acquired a TXOP on Link 1, can transmit information about an IDC event of STA2 on Link 2 through the A-control field included in a QoS data (or null) frame transmitted on Link 1. AP 1 can transmit a BA frame if an immediate ACK policy is set for the QoS data (or null) frame.

[0287] The control ID of a specific control subfield of the A-control field may be set to a value indicating that it contains IDC-related information. The IDC information may include information regarding the IDC start time, duration, etc., in the examples described above. If additional control subfield(s) are included within the A-control field, each control subfield may be set to a value indicating that it contains respective feedback information (e.g., LLT-related information, BSR-related information, MAPC-related information, NPCA-related information, etc.). Alternatively, if various feedback information is included in a single control subfield as in the examples described below, that control subfield may be set to a single specific value indicating that it contains various feedback information. The remaining bits of the A-control field may correspond to padding bits.

[0288] Link information may include link identifier (ID) information. A link ID for each link may be obtained through a discovery process (e.g., receiving a beacon frame, exchanging probe requests / responses), an association process, etc. If feedback information for one or more links is included, information regarding the number of link IDs may be further included to indicate how many links for which feedback information is included. If feedback information for multiple links is included, one or more feedback information from the first link may be included following the link information set to a first link ID value, and one or more feedback information from the second link may be included following the link information set to a second link ID value.

[0289] Alternatively, the link information may include a link ID bitmap. The link ID bitmap may indicate link(s) associated with specific feedback information. For example, the i-th bit position within the bitmap may correspond to the value i of the link ID. For example, if a link ID bitmap for IDC-related information is included, the link(s) corresponding to the bit position set to a specific value (e.g., 1) within the bitmap may correspond to the link(s) where the IDC-related information is provided. For additional feedback information other than IDC-related information, the link associated with that feedback information may also be indicated through the link ID bitmap. The size of such a link ID bitmap may be predefined to be at least two octets. If the bitmap size is variable, additional information indicating the size of the bitmap (e.g., one octet, two octets, etc.) may be included.

[0290] In the example of FIG. 16, the QoS data (or null) frame transmitted by STA 1 operating on Link 1 includes an A-control field, and the A-control field may include IDC-related information.

[0291] For example, the control ID value of the control subfield of the A-control field can be set to a value indicating that IDC information is included (or a value indicating that various feedback information is included). The link information can be set to a value indicating that the IDC-related information is for Link 2 (e.g., 1). In this case, the IDC information may include information such as the start time and duration of the IDC event of STA 2 operating on Link 2.

[0292] In this way, STA 1 can transmit feedback information for STA 2, which belongs to the same non-AP MLD. AP 1, operating on Link 1, can obtain IDC-related information for STA 2, which operates on Link 2, and provide it to AP 2, which belongs to the same AP MLD. If AP 2 subsequently obtains a TXOP, it may not transmit a frame to STA 2 or trigger STA 2 to transmit a frame during the period corresponding to STA 2's IDC event.

[0293] Example 5

[0294] This embodiment relates to a new A-control field containing various feedback information.

[0295] In order to support backward compatibility so as not to interfere with the operation of legacy devices, size limitations for the A-control field may be considered (e.g., a maximum size of 32 bits for the HT control field containing the A-control field, a maximum size of 30 bits for the A-control field, and a maximum size of 26 bits for the control subfield excluding the control ID (4 bits) when one A-control field contains one control subfield). Considering these size limitations for the A-control field, in order to include various feedback information in one A-control field (or one control subfield), it is required to select the information to be included.

[0296] Additionally, a new control ID value may be defined for a single A-control field (or a single control subfield) containing various feedback information. The new control ID may be assigned as one of the values ​​from 10 to 14 that are not used as existing control IDs. For example, in the example of Table 4, a specific control ID value (e.g., 11) may be defined as CCI (common control info).

[0297] These new A-control fields may be included in QoS data frames, QoS null frames, and / or management frames. An STA that wishes to convey feedback information (or control information) may convey said feedback information by transmitting a frame containing the A-control field during frame exchange.

[0298] FIG. 17 illustrates an example of transmitting feedback information using an A-control field when the AP according to the present disclosure is a TXOP holder.

[0299] It is assumed that AP corresponds to UHR AP, STA 1 corresponds to legacy STA, and STA 2 corresponds to UHR STA. It is assumed that UHR AP and UHR STA have the capability to transmit / receive feedback information through the A-control field of various examples according to the present disclosure, and that legacy STA does not have such capability.

[0300] AP can send a BSRP TF to STA 1 and STA 2, and in response, STA 1 can send a QoS null frame and STA 2 can send an M-BA (multi-STA block ACK) frame. Accordingly, AP can acquire a TXOP.

[0301] AP, the TXOP holder, can send a basic TF to STA1 and STA2 to petition for the transmission of UL data from STAs while an IDC event in STA2 has not yet been anticipated or detected. During the preparation for transmitting the UL data frame, the occurrence of an IDC event in STA2 may be anticipated or detected. Accordingly, STA2 can transmit a QoS data frame containing IDC-related information in the A-control field, and the AP receiving this can determine the start time, duration, etc. of STA2's unavailable period from the IDC-related information included in the A-control field.

[0302] Since the data frame containing the A-control field transmitted by STA 2 must be transmitted in the UL MU manner together with the data frame transmitted by STA 1, the A-control field may need to satisfy the aforementioned size limit.

[0303] FIG. 18 illustrates an example of transmitting feedback information using an A-control field when the STA according to the present disclosure is a TXOP holder.

[0304] It is assumed that AP corresponds to UHR AP and STA corresponds to UHR STA. It can be assumed that UHR AP and UHR STA have the capability to transmit / receive feedback information through the A-control field of various examples according to the present disclosure.

[0305] The STA can send a BSRP TF to the AP, and in response, the AP can send an M-BA (multi-STA block ACK) frame. Accordingly, the STA can acquire a TXOP.

[0306] A STA, which is a TXOP holder, can transmit data to an AP while an IDC event in the STA has not yet been anticipated or detected. During the transmission of data, the occurrence of an IDC event in the STA may be anticipated or detected. Accordingly, the STA can transmit data by including IDC-related information in the A-control field of a QoS data frame, and the AP receiving this can determine the start time, duration, etc. of the STA's unavailable period from the IDC-related information included in the A-control field.

[0307] FIG. 19 is a drawing showing examples of A-control fields including various feedback information according to the present disclosure.

[0308] For example, various feedback information (e.g., two or more of IDC (or unavailability) related feedback information, DPS related feedback information, NPCA related feedback information, LLT related feedback information) may be included in a single A-control field.

[0309] In the examples of FIG. 19, multiple feedback information may be included in the 30-bit A-control field of the 32-bit HT control field.

[0310] The first two bits (B0 and B1) of the HT control field can be set to a value representing the HE variant (or UHR variant) (see Table 3). Assuming the A-control field contains one control subfield, the first four bits of the A-control field (or the first four bits of the control subfield) correspond to the control ID. The control ID can be set to one of the values ​​7 through 14 (or one of the previously reserved values ​​11 through 14 as previously mentioned). This new control ID value may indicate that various feedback information (e.g., IDC-related information and LLT-related information) is included.

[0311] The control information field following the control ID field can be configured to satisfy a 26-bit size limit as in the following examples.

[0312] The example in FIG. 19(a) shows an example in which multiple feedback information is included in a single A-control field based on the existence bit for individual feedback information.

[0313] For example, the control information field may include a 1-bit start time present field, a 1-bit duration present field, and a 1-bit LLT present field. The field may be included if the value of each present field is a specific value (e.g., 1), and may not be included if it is another value (e.g., 0). If the 9-bit start time field, the 9-bit duration field, and the 1-bit LLT field are all included, the reserved field is defined as having a size of 4 bits, which may satisfy the 30-bit size limit of the A-control field. If some field(s) are not included, bits corresponding to the size of those field(s) may be included as a reserved field or padding field.

[0314] FIGS. 19(b) to 19(d) illustrate an example in which multiple feedback information is included in a single A-control field based on a bitmap of common control information (or feedback information) existence.

[0315] For example, the control information field may include a 1-bit unavailability presence field, a 1-bit LLT presence field, and a 1-bit CL (cross-link power save) presence field. If the value of the unavailability presence field is a specific value (e.g., 1), the start time field and the duration field may be included, and if it is another value (e.g., 0), the start time field and the duration field may not be included. If the value of the 1-bit LLT presence field is a specific value (e.g., 1), the LLT (indicator) field may be included, and if it is another value (e.g., 0), the LLT (indicator) field may not be included. If the value of the 1-bit CL presence field is a specific value (e.g., 1), the CL-related field may be included, and if it is another value (e.g., 0), the CL-related field may not be included.

[0316] FIG. 19(c) shows an example in which multiple feedback information based on type information is included in a single A-control field.

[0317] For example, the control information field may include one or more 2-bit type fields. Each type field may be set to a value indicating the type to which the subsequent feedback information belongs. For example, a start time field and a duration field may be included following a type field indicating unavailability. For example, an LLT (indicator) field may be included following a type field indicating LLT. The remaining bits may be included as reserved fields.

[0318] In this way, one or multiple feedback information may be included in a single A-control field (or a single control subfield) based on existence bits or type fields, and some feedback information may be omitted to satisfy the 26-bit size limit of the control information field of the control subfield of the A-control field. For example, among various IDC (or availability) related parameters, other parameters (e.g., interval, continuity, channel / BW, NSS, etc.) may be omitted, excluding the start time and duration, which are minimal information.

[0319] Figure 19(f) shows an example of an extended ID-based A-control field.

[0320] For example, you can define an extension of the control ID for the A-control field to expand its size to include more feedback information. For example, for the value of the control ID field of the control subfield of A-control, you can define a specific value (e.g., one of the reserved values ​​11 to 14) as the extension ID.

[0321] When the value of a control ID field is set to an extended ID value, the control subfield may include a sub-control ID field. Various feedback information may be distinguished by different sub-control ID values. For example, following the value of the same control ID field, one or more fields corresponding to a sub-control ID field set to a first value and first feedback information may be included, and then one or more fields corresponding to a sub-control ID field set to a second value and second feedback information may be included.

[0322] In this case, the 32-bit (=4 octets) size limit for the HT control field is not applied, and a new size of 8 octets, 16 octets, or more may be defined. Consequently, the size of the MAC header may change, so backward compatibility may not be supported.

[0323] According to the examples of the present disclosure, various feedback information can be transmitted to the other party during frame exchange through an A-control field included in a QoS data frame, QoS null frame, or management frame. Furthermore, the feedback information included in the A-control field is not limited to a single type or a single parameter, but can include multiple types of feedback information (e.g., feedback information related to availability, DPS-related feedback information, NPCA-related feedback information, LLT-related feedback information, etc.), thereby achieving a new effect of dynamically and immediately transmitting various feedback information to the other party.

[0324] 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.

[0325] 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.

[0326] 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.

[0327] Although the method proposed in this disclosure has been described with an example applied to an IEEE 802.11-based system, it can be applied to various wireless LANs or wireless communication systems in addition to IEEE 802.11-based systems.

Claims

1. A step of generating a frame by a first station (STA) that includes a merged-control (A-control) field including a specific control subfield; and The method includes the step of transmitting a PPDU (physical layer protocol data unit) containing the above frame to a second STA by the first STA, The above specific control subfield includes one or more of multiple feedback information, and A method in which the above specific control subfield further includes information indicating whether each of the above multiple feedback information is included.

2. In Paragraph 1, Information indicating whether each of the above multiple feedback information is included corresponds to a multiple existence field, and A method in which the number of the above multiple existence fields is the same as the number of the above multiple feedback information.

3. In Paragraph 1, Information indicating whether each of the above multiple feedback information is included corresponds to the type field, and The above specific control subfield includes one or more type fields, and A method in which one or more of the multiple feedback information included in the specific control subfield correspond to each of the one or more type fields.

4. In Paragraph 3, The first value of the above type field corresponds to the first feedback information, and A method in which the second value of the above type field corresponds to the second feedback information.

5. In Paragraph 1, A method in which the above-mentioned specific control subfield includes minimum information among first feedback information and minimum information among second feedback information.

6. In Paragraph 1, The first feedback information includes one or more fields, and A method in which the second feedback information includes one or more fields.

7. In Paragraph 1, The first feedback information corresponds to the first operation mode, and A method in which the second feedback information corresponds to the second operation mode.

8. In Paragraph 1, A method comprising two or more of the above multiple feedback information, including unavailability-related feedback information, dynamic power saving (DPS)-related feedback information, non-primary channel access (NPCA)-related feedback information, or low latency traffic (LLT)-related feedback information.

9. In Paragraph 1, The above specific control subfield includes a control ID field set to a single control identifier (ID) value, and A method in which the above-mentioned single control identifier value is common to the above-mentioned multiple feedback information.

10. In Paragraph 9, A method in which, within a specific control subfield having a single control identifier value, the multiple feedback information is distinguished based on the sub-control identifier value.

11. 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: Create a frame containing a merge-control (A-control) field including a specific control subfield; and It is configured to transmit a PPDU (physical layer protocol data unit) containing the above frame to a second station (STA) through the one or more transceivers, and The above specific control subfield includes one or more of multiple feedback information, and The above specific control subfield further includes information indicating whether each of the multiple feedback information is included, a first STA.

12. A step of receiving a PPDU (physical layer protocol data unit) containing a frame from the first STA by the second station (STA); and The method includes the step of obtaining one or more of multiple feedback information from a specific control subfield of a merge-control (A-control) field included in the frame, and A method in which the specific control subfield above includes information indicating whether each of the multiple feedback information is included.

13. One or more transceivers; and It includes one or more processors connected to the above one or more transmitters and receivers, and The above one or more processors are: Receiving a PPDU (physical layer protocol data unit) containing a frame from a first station (STA) through one or more transceivers; and It is configured to acquire one or more of multiple feedback information from a specific control subfield of a merge-control (A-control) field included in the above frame, and The specific control subfield above includes information indicating whether each of the multiple feedback information is included, a second STA.

14. 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 10 based on execution by one or more processors.

15. 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 10.

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