Method and device for performing ofdma-based random access in wireless LAN system

Abstract

Various embodiments of the present disclosure relate to a method and device for performing an orthogonal frequency division multiple access (OFDMA)-based random access in a wireless LAN system. The method performed by a first access point (AP) according to an embodiment of the present disclosure may comprise the steps of: receiving a control frame from a second AP, wherein the control frame includes information related to the fact that a portion of a transmission opportunity (TXOP) of the second AP is to be used in a multi-AP (M-AP) coordinated transmission scheme; and performing an operation related to an AP OFDMA-based random access for transmitting an accept response related to using the M-AP coordinated transmission scheme in the portion of the TXOP of the second AP.

Description

Method and device for performing OFDMA-based random access in a wireless LAN system

[0001] The present disclosure generally relates to wireless LAN systems, and more specifically to a method and apparatus for performing OFDMA-based random access in a wireless LAN system.

[0002] A Wireless Local Area Network (WLAN), also known as Wi-Fi, is a network that enables internet access via mobile devices or laptops within a certain distance from an access point (AP). WLAN technology continues to evolve in line with the rise of the internet and the expansion of the smartphone market, and is being utilized to provide high-speed data services throughout entire cities, including in schools, airports, hotels, and offices.

[0003] The WiFi Alliance defines WiFi as a Wireless Local Area Network (WLAN) product based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard. IEEE 802.11a and b, published in 1997 and 1999 respectively, are standards utilizing unlicensed bands at 2.4 GHz or 5 GHz; IEEE 802.11b provides a transmission speed of 11 Mbps, while IEEE 802.11a provides a transmission speed of 54 Mbps. IEEE 802.11g provides a transmission speed of 54 Mbps by applying Orthogonal Frequency-Division Multiplexing (OFDM) at 2.4 GHz. IEEE 802.11n applies multiple input multiple output OFDM (MIMO-OFDM) to provide a transmission speed of 300 Mbps using four spatial streams. IEEE 802.11n supports a channel bandwidth of up to 40 MHz, in which case it provides a transmission speed of 600 Mbps.

[0004] Subsequently, the IEEE 802.11ac standard was introduced, which uses a maximum bandwidth of 160 MHz and supports eight spatial streams to support speeds up to 1 Gbit / s, and the IEEE 802.11ax standard was introduced, which provides multi-user MIMO (MU-MIMO) in the uplink and downlink and supports spatial frequency reuse and dynamic fragmentation. Since then, research is underway on 802.11be, which aims to achieve theoretical speeds of 46 Gbps by supporting up to 320 ultra-wide channels, multi-link operation, and 4kQAM.

[0005] The above information is provided for background information only to aid in understanding the present disclosure. No determination or claim has been made as to whether any of the above contents can be applied as prior art to the present disclosure.

[0006] Various embodiments of the present disclosure may provide a method and apparatus for performing OFDMA-based random access in a wireless LAN system.

[0007] The technical problems to be solved in the various embodiments of the present disclosure are not limited to those mentioned above, and other unmentioned technical problems may be considered by those skilled in the art from the various embodiments of the present disclosure described below.

[0008] A method performed by a first AP (access point) in a wireless LAN (local access network) according to one embodiment of the present disclosure comprises the steps of receiving a control frame from a second AP, wherein the control frame includes information relating that a portion of the transmission opportunity (TXOP) of the second AP will be used for a multi-AP (multi-AP) coordinated transmission scheme; and performing an operation relating to an AP OFDMA (orthogonal frequency division multiple access)-based random access for transmitting an accept response relating to using the multi-Access Point Coordination (MAPC) transmission scheme in a portion of the TXOP of the second AP.

[0009] According to one embodiment of the present disclosure, the control frame includes one or more AID (association identifier)12 subfields set to values ​​associated with the first AP among values ​​predefined for the AP OFDMA-based random access.

[0010] According to one embodiment of the present disclosure, the operation associated with the AP OFDMA-based random access is based on one or more RUs corresponding to one or more AID12 subfields among a plurality of RUs (resource units) indicated in the control frame.

[0011] According to one embodiment of the present disclosure, each of the above-mentioned predefined values ​​is defined within 2008 to 2044 and 2047 to 4094.

[0012] According to one embodiment of the present disclosure, the predefined values ​​include: the first value indicating that the RU corresponding to the AID12 subfield set to the first value is a random access-RU (RA-RU) for an uncoordinated AP; the second value indicating that the RU corresponding to the AID12 subfield set to the second value is a RA-RU for an uncoordinated AP having low latency (LL) traffic; the third value indicating that the RU corresponding to the AID12 subfield set to the third value is a RA-RU for a coordinated AP; or the fourth value indicating that the RU corresponding to the AID12 subfield set to the fourth value is a RA-RU for a coordinated AP having traffic that exceeds a predefined priority or has a priority greater than or equal to the predefined priority.

[0013] According to one embodiment of the present disclosure, when the first AP decides to use the M-AP cooperative transmission scheme in part of the TXOP of the second AP, the acknowledgment response is transmitted from the control frame after a specific IFS (inter frame space).

[0014] According to one embodiment of the present disclosure, if the first AP decides not to use the M-AP cooperative transmission scheme in part of the TXOP of the second AP, a response for the control frame is not transmitted from the control frame after the specific IFS (inter frame space).

[0015] According to one embodiment of the present disclosure, when the control frame is an initial control frame (ICF) for polling: the number of RA-RUs included in the plurality of RUs is less than the number of the plurality of RUs, and one or more RUs are included in the RA-RUs, and the number of RA-RUs corresponding to one value for a non-cooperative AP among the values ​​of the AID12 subfields included in the control frame is at most one.

[0016] According to one embodiment of the present disclosure, when the first AP is a cooperative AP and a parameter set element for the AP OFDMA-based random access is exchanged, an OBO (OFDMA random access backoff) counter related to the operation related to the AP OFDMA-based random access is determined within a specific OCW range identified among a plurality of OCW (OFDMA contention window) ranges included in the parameter set element.

[0017] According to one embodiment of the present disclosure, if the first AP is a cooperative AP and the parameter set element is not exchanged, a predefined default value is determined as the OBO counter.

[0018] According to one embodiment of the present disclosure, if the first AP is a non-cooperative AP, the predefined default value is determined as the OBO counter.

[0019] According to one embodiment of the present disclosure, the step of performing an operation related to the AP OFDMA-based random access comprises: decreasing the OBO counter based on one or more RUs; randomly selecting a specific RU among the one or more RUs when the OBO counter is decreased to 0; and transmitting the acknowledgment response at the specific RU.

[0020] According to one embodiment of the present disclosure, a first AP (access point) of a wireless LAN (local access network) comprises: a transceiver; and a processor connected to the transceiver, wherein the processor: receives a control frame from a second AP, the control frame comprising information relating that a portion of the TXOP (transmission opportunity) of the second AP will be used for a multi-AP (multi-AP) coordinated transmission scheme; and is configured to perform an operation relating to an AP OFDMA (orthogonal frequency division multiple access)-based random access for transmitting an accept response relating to using the multi-AP coordinated (MAPC) transmission scheme in a portion of the TXOP of the second AP.

[0021] According to one embodiment of the present disclosure, the control frame includes one or more AID (association identifier)12 subfields set to values ​​associated with the first AP among values ​​predefined for the AP OFDMA-based random access.

[0022] According to one embodiment of the present disclosure, the operation associated with the AP OFDMA-based random access is based on one or more RUs corresponding to one or more AID12 subfields among a plurality of RUs (resource units) indicated in the control frame.

[0023] According to one embodiment of the present disclosure, each of the above-mentioned predefined values ​​is defined within 2008 to 2044 and 2047 to 4094.

[0024] According to one embodiment of the present disclosure, the predefined values ​​include: the first value indicating that the RU corresponding to the AID12 subfield set to the first value is a random access-RU (RA-RU) for an uncoordinated AP; the second value indicating that the RU corresponding to the AID12 subfield set to the second value is a RA-RU for an uncoordinated AP having low latency (LL) traffic; the third value indicating that the RU corresponding to the AID12 subfield set to the third value is a RA-RU for a coordinated AP; or the fourth value indicating that the RU corresponding to the AID12 subfield set to the fourth value is a RA-RU for a coordinated AP having traffic that exceeds a predefined priority or has a priority greater than or equal to the predefined priority.

[0025] According to one embodiment of the present disclosure, when the first AP determines to use the M-AP cooperative transmission scheme in part of the TXOP of the second AP, the acknowledgment response is transmitted from the control frame after a specific IFS (inter frame space).

[0026] According to one embodiment of the present disclosure, if the first AP decides not to use the M-AP cooperative transmission scheme in part of the TXOP of the second AP, a response for the control frame is not transmitted from the control frame after the specific IFS (inter frame space).

[0027] According to one embodiment of the present disclosure, when the control frame is an initial control frame (ICF) for polling: the number of RA-RUs included in the plurality of RUs is less than the number of the plurality of RUs, and one or more RUs are included in the RA-RUs, and the number of RA-RUs corresponding to one value for a non-cooperative AP among the values ​​of the AID12 subfields included in the control frame is at most one.

[0028] According to one embodiment of the present disclosure, when the first AP is a cooperative AP and a parameter set element for the AP OFDMA-based random access is exchanged, an OBO (OFDMA random access backoff) counter related to the operation related to the AP OFDMA-based random access is determined within a specific OCW range identified among a plurality of OCW (OFDMA contention window) ranges included in the parameter set element.

[0029] According to one embodiment of the present disclosure, if the first AP is a cooperative AP and the parameter set element is not exchanged, a predefined default value is determined as the OBO counter.

[0030] According to one embodiment of the present disclosure, if the first AP is a non-cooperative AP, the predefined default value is determined as the OBO counter.

[0031] According to one embodiment of the present disclosure, in performing operations related to the AP OFDMA-based random access, the processor is configured to: decrease the OBO counter based on one or more RUs; randomly select a specific RU among the one or more RUs when the OBO counter is decreased to 0; and transmit the acknowledgment response at the specific RU.

[0032] A method performed by a second AP (access point) in a wireless LAN (local access network) according to one embodiment of the present disclosure comprises the steps of: transmitting a control frame, wherein the control frame includes information relating that a portion of the transmission opportunity (TXOP) of the second AP will be used in a multi-AP (multi-AP) coordinated transmission scheme; and receiving an accept response from a first AP relating that the first AP will use the multi-Access Point Coordination (MAPC) transmission scheme in a portion of the TXOP of the second AP.

[0033] According to one embodiment of the present disclosure, the control frame includes one or more AID (association identifier)12 subfields set to values ​​associated with the first AP among values ​​predefined for AP OFDMA (orthogonal frequency division multiple access)-based random access.

[0034] According to one embodiment of the present disclosure, the acknowledgment response is received at a specific RU among one or more RUs corresponding to one or more AID12 subfields among a plurality of RUs (resource units) indicated in the control frame.

[0035] According to one embodiment of the present disclosure, each of the above-mentioned predefined values ​​is defined within 2008 to 2044 and 2047 to 4094.

[0036] According to one embodiment of the present disclosure, the predefined values ​​include: the first value indicating that the RU corresponding to the AID12 subfield set to the first value is a random access-RU (RA-RU) for an uncoordinated AP; the second value indicating that the RU corresponding to the AID12 subfield set to the second value is a RA-RU for an uncoordinated AP having low latency (LL) traffic; the third value indicating that the RU corresponding to the AID12 subfield set to the third value is a RA-RU for a coordinated AP; or the fourth value indicating that the RU corresponding to the AID12 subfield set to the fourth value is a RA-RU for a coordinated AP having traffic that exceeds a predefined priority or has a priority greater than or equal to the predefined priority.

[0037] According to one embodiment of the present disclosure, the message includes one or more of an M-AP (multi-AP) discovery or agreement establishment request.

[0038] A second AP (access point) of a wireless LAN (local access network) according to one embodiment of the present disclosure comprises: a transceiver; and a processor connected to the transceiver, and the processor comprises:

[0039] Transmit a control frame, the control frame containing information that part of the TXOP (transmission opportunity) of the second AP will be used for a multi-AP (multi-AP) coordinated transmission scheme; and are configured to receive an accept response from the first AP that the first AP will use the multi-Access Point Coordination (MAPC) transmission scheme in part of the TXOP of the second AP.

[0040] According to one embodiment of the present disclosure, the control frame includes one or more AID (association identifier)12 subfields set to values ​​associated with the first AP among values ​​predefined for AP OFDMA (orthogonal frequency division multiple access)-based random access.

[0041] According to one embodiment of the present disclosure, the acknowledgment response is received at a specific RU among one or more RUs corresponding to one or more AID12 subfields among a plurality of RUs (resource units) indicated in the control frame.

[0042] According to one embodiment of the present disclosure, each of the above-mentioned predefined values ​​is defined within 2008 to 2044 and 2047 to 4094.

[0043] According to one embodiment of the present disclosure, the predefined values ​​include: the first value indicating that the RU corresponding to the AID12 subfield set to the first value is a random access-RU (RA-RU) for an uncoordinated AP; the second value indicating that the RU corresponding to the AID12 subfield set to the second value is a RA-RU for an uncoordinated AP having low latency (LL) traffic; the third value indicating that the RU corresponding to the AID12 subfield set to the third value is a RA-RU for a coordinated AP; or the fourth value indicating that the RU corresponding to the AID12 subfield set to the fourth value is a RA-RU for a coordinated AP having traffic that exceeds a predefined priority or has a priority greater than or equal to the predefined priority.

[0044] A method performed by a third AP (access point) in a wireless LAN (local access network) according to one embodiment of the present disclosure comprises the steps of: transmitting a non-polling control frame, wherein the non-polling control frame indicates a plurality of RUs (resource units); and receiving a message from a fourth AP at a specific RU among the plurality of RUs.

[0045] According to one embodiment of the present disclosure, the plurality of RUs can all be assigned as RA-RUs (random access-RUs), and the specific RU is included in one or more RUs assigned as RA-RUs among the plurality of RUs.

[0046] According to one embodiment of the present disclosure, the non-polling control frame includes one or more association identifiers (AIDs)12 that are set as values ​​associated with the fourth AP among values ​​predefined for AP OFDMA (orthogonal frequency division multiple access)-based random access.

[0047] According to one embodiment of the present disclosure, one or more RUs assigned to the RA-RU among the plurality of RUs correspond to the one or more AID12s.

[0048] According to one embodiment of the present disclosure, the method further comprises the step of performing an intra-BSS (basic service set) frame exchange within a TXOP (transmission opportunity) of the third AP, and the non-polling control frame is transmitted after the intra-BSS frame exchange is performed.

[0049] According to one embodiment of the present disclosure, the message includes one or more requests or responses for M-AP (multi-AP) discovery, agreement establishment, or parameter negotiation.

[0050] A third AP (access point) of a wireless LAN (local access network) according to one embodiment of the present disclosure comprises: a transceiver; and a processor connected to the transceiver, wherein the processor: transmits a non-polling control frame, the non-polling control frame indicates a plurality of resource units (RUs); and is configured to receive a message from a fourth AP at a specific RU among the plurality of RUs.

[0051] According to one embodiment of the present disclosure, the plurality of RUs can all be assigned as RA-RU (random access-RU) and are included in one or more RUs assigned as RA-RU among the plurality of RUs.

[0052] According to one embodiment of the present disclosure, the non-polling control frame includes one or more association identifiers (AIDs)12 that are set as values ​​associated with the fourth AP among values ​​predefined for AP OFDMA (orthogonal frequency division multiple access)-based random access.

[0053] According to one embodiment of the present disclosure, one or more RUs assigned to the RA-RU among the plurality of RUs correspond to the one or more AID12s.

[0054] According to one embodiment of the present disclosure, the processor is configured to perform an intra-BSS (basic service set) frame exchange within a TXOP (transmission opportunity) of the third AP.

[0055] According to one embodiment of the present disclosure, the non-polling control frame is transmitted after the intra-BSS frame exchange is performed.

[0056] According to one embodiment of the present disclosure, the message includes one or more requests or responses for M-AP (multi-AP) discovery, agreement establishment, or parameter negotiation.

[0057] The various embodiments of the present disclosure described above are merely some of the preferred embodiments of the present disclosure, and various embodiments reflecting the technical features of the various embodiments of the present disclosure can be derived and understood by those skilled in the art based on the detailed description to be described below.

[0058] According to various embodiments of the present disclosure, a method and apparatus for performing OFDMA-based random access in a wireless LAN system may be provided.

[0059] According to various embodiments of the present disclosure, a method for an AP to perform an OFDMA-based random access may be provided.

[0060] According to various embodiments of the present disclosure, participation in M-AP (multi-access point) coordination operations can be transmitted based on OFDMA-based random access, thereby increasing resource efficiency of control frames.

[0061] According to various embodiments of the present disclosure, a discovery or agreement establishment request may be transmitted based on an OFDMA-based random access, thereby eliminating the need for a separate backoff operation and reducing overhead.

[0062] The effects obtainable from the various embodiments of the present disclosure are not limited to those mentioned above, and other unmentioned effects can be clearly derived and understood by those skilled in the art based on the following detailed description.

[0063] The drawings attached below are intended to aid in understanding various embodiments of the present disclosure and provide various embodiments of the present disclosure together with the detailed description. However, the technical features of the various embodiments of the present disclosure are not limited to specific drawings, and the features disclosed in each drawing may be combined with one another to form new embodiments. Reference numerals in each drawing denote structural elements.

[0064] FIG. 1 is a drawing illustrating an example of a wireless communication network to which various embodiments of the present disclosure are applicable.

[0065] FIG. 2 is a drawing illustrating an example of the structure of an electronic device for performing a WLAN connection to which various embodiments of the present disclosure are applicable.

[0066] FIG. 3 is a diagram illustrating an example of a link setup process of a general wireless LAN to which various embodiments of the present disclosure are applicable.

[0067] FIG. 4 is a drawing illustrating an example of a hidden node and an exposed node to which various embodiments of the present disclosure are applicable, and an example of an RTS and CTS for solving the problem of a hidden node and an exposed node.

[0068] FIG. 5 is a drawing illustrating an example of a frame structure used in an IEEE 802.11 system to which various embodiments of the present disclosure are applicable.

[0069] FIG. 6 is a drawing illustrating an example of a NAV setting to which various embodiments of the present disclosure are applicable.

[0070] FIG. 7 is a drawing illustrating an example of a TXOP to which various embodiments of the present disclosure are applicable.

[0071] FIG. 8 illustrates an example of communication between APs to which an embodiment of the present disclosure is applicable.

[0072] FIG. 9 illustrates an example of a UORA operation to which an embodiment of the present disclosure is applicable.

[0073] FIG. 10 shows an example of a User Info field format according to one embodiment of the present disclosure.

[0074] FIG. 11 illustrates an example of communication between APs according to one embodiment of the present disclosure.

[0075] FIG. 12 shows an example of a UORA parameter set element format and an OCW range field format according to one embodiment of the present disclosure.

[0076] FIG. 13 illustrates an example of communication between APs to which an embodiment of the present disclosure is applicable.

[0077] FIG. 14 is a diagram illustrating an example of AP UORA operation based on a non-polling control frame according to one embodiment of the present disclosure.

[0078] FIG. 15 is a diagram illustrating an example of AP UORA operation based on a non-polling control frame according to one embodiment of the present disclosure.

[0079] FIG. 16 illustrates an example of the operation of a first AP according to one embodiment of the present disclosure.

[0080] FIG. 17 illustrates an example of the operation of a second AP according to one embodiment of the present disclosure.

[0081] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0082] In describing the embodiments, technical details that are well known in the art to which this disclosure belongs and are not directly related to this disclosure are omitted. This is intended to convey the essence of this disclosure more clearly without obscuring it by omitting unnecessary explanations.

[0083] For the same reason, some components in the attached drawings have been exaggerated, omitted, or schematically depicted. Additionally, the size of each component does not entirely reflect its actual dimensions. Identical or corresponding components in each drawing have been assigned the same reference number.

[0084] The advantages and features of the present disclosure and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below but may be implemented in various different forms. The embodiments of the present disclosure are provided merely to make the present disclosure complete and to fully inform those skilled in the art of the scope of the disclosure, and the present disclosure is defined only by the scope of the claims. Throughout the specification, like reference numerals refer to like components.

[0085] At this point, it will be understood that each block of the process flow diagrams and combinations of the flow diagrams can be executed by computer program instructions. Since these computer program instructions can be loaded into the processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, the instructions executed through the processor of the computer or other programmable data processing equipment create means to perform the functions described in the flow diagram block(s). Since these computer program instructions can also be stored in computer-available or computer-readable memory that can be directed toward the computer or other programmable data processing equipment to implement the function in a specific way, the instructions stored in computer-available or computer-readable memory can also produce a manufactured item containing means of instruction to perform the function described in the flow diagram block(s).

[0086] Since computer program instructions can be loaded onto a computer or other programmable data processing equipment, instructions that execute a computer or other programmable data processing equipment by performing a series of operation steps on the computer or other programmable data processing equipment to create a process executed by the computer may also provide steps for executing the functions described in the flowchart block(s).

[0087] Additionally, each block may represent a module, segment, or part of code containing one or more executable instructions for executing a specific logical function(s). It should also be noted that in some alternative execution examples, the functions mentioned in the blocks may occur out of order. For instance, two blocks described in succession may actually be executed substantially simultaneously, or the blocks may be executed in reverse order depending on the corresponding function.

[0088] In this embodiment, the term "part" as used refers to a software or hardware component such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC), and the "part" performs certain roles. However, the meaning of "part" is not limited to software or hardware. The "part" may be configured to reside in an addressable storage medium or may be configured to run one or more processors. Accordingly, according to some embodiments, the "part" includes components such as software components, object-oriented software components, class components, and task components, as well as processes, functions, attributes, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and "parts" may be combined into a smaller number of components and "parts" or further separated into additional components and "parts." In addition, the components and 'parts' may be implemented to utilize one or more CPUs within the device or secure multimedia card. Also, according to some embodiments, the 'parts' may include one or more processors.

[0089] Exemplary embodiments are described below in relation to wireless LAN systems solely for the sake of simplicity. It should be understood that the exemplary embodiments are equally applicable to systems using signals of one or more wired standards or protocols (e.g., Ethernet and / or HomePlug, PLC standards), as well as other wireless networks (e.g., cellular networks, pico networks, femto networks, satellite networks). As used herein, the terms WLAN and Wi-Fi® may include communications controlled by the IEEE 802.11 family of standards, BLUETOOTH®, HiperLAN (a set of wireless standards comparable to IEEE 802.11 standards, mainly used in Europe), and other technologies having a relatively short wireless propagation range. Accordingly, the terms WLAN and Wi-Fi may be used interchangeably herein. Additionally, although the following describes an infrastructure WLAN system including one or more APs and multiple wireless stations (STAs), exemplary embodiments are equally applicable to other WLAN systems including, for example, multiple WLANs, peer-to-peer (or independent basic service set) systems, Wi-Fi Direct systems and / or hotspots.

[0090] Additionally, while this specification describes the exchange of data frames between wireless devices, exemplary embodiments may be applied to the exchange of any data unit, packet, and / or frame between wireless devices. Accordingly, the term "frame" may include any frame, packet, or data unit such as, for example, protocol data units (PDUs), media access control (MAC) protocol data units (MPDUs), and physical layer convergence procedure (PLCP) protocol data units (PPDUs). The term A-MPDU may mean aggregated MPDUs. In the following, a wireless LAN, or WLAN network, may be a network implementing at least one of the IEEE 802.11 wireless communication protocol standard families, such as defined by the IEEE 802.11-2016 standard or its amendments (including, but not limited to, 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be).

[0091] In the following description, many specific details, such as examples of specific components, circuits, and processes, are presented to provide a thorough understanding of the present disclosure. As used herein, the term “connected” means being directly connected or being connected through one or more intervening components or circuits. The term “connected AP” means an access point to which a given wireless station is currently associated and / or connected (e.g., there exists a communication channel or link established between the access point and the given wireless station). Additionally, in the following description and for illustrative purposes, specific nomenclature is presented to provide a thorough understanding of exemplary embodiments. However, it will be apparent to those skilled in the art that these specific details may not be necessary to carry out the exemplary embodiments. In other cases, to avoid obscuring the present disclosure, well-known circuits and devices are illustrated in block diagram form.

[0092] The operating principles of the present disclosure will be described in detail below with reference to the attached drawings. In describing the present disclosure below, specific descriptions of related known functions or configurations will be omitted if it is determined that such detailed descriptions would unnecessarily obscure the essence of the present disclosure. Furthermore, the terms described below are defined in consideration of their functions in the present disclosure, and these may vary depending on the intentions or practices of the user or operator. Therefore, their definitions should be based on the content throughout this specification.

[0093] FIG. 1 is a drawing illustrating an example of a wireless communication network to which various embodiments of the present disclosure are applicable.

[0094] A wireless communication network (100) may be an example of a wireless LAN, such as a Wi-Fi network. The wireless communication network (100) may include multiple wireless communication devices, such as an AP (102) and multiple STAs (stations, 104). Although only one AP (102) is shown, the wireless communication network (100) may also include multiple APs (102).

[0095] A STA is a logical entity that includes a physical layer interface for a MAC and a wireless medium, and includes APs and non-AP STAs (Non-AP stations). Among the STAs, a portable terminal operated by a user is a Non-AP STA, and when simply referred to as STA, it may also refer to a Non-AP STA. Hereinafter, STA may refer to a non-AP STA. Each of the STAs (104) may be referred to as a terminal or a device. The terms 'terminal' or 'device' used in this specification may be referred to as a mobile station (MS), user equipment (UE), user terminal (UT), wireless terminal, access terminal (AT), terminal, subscriber unit, subscriber station (SS), wireless device, wireless communication device, wireless transmit / receive unit (WTRU), mobile node, mobile, or other terms. Various embodiments of the terminal may include cellular telephones, smartphones with wireless communication capabilities, personal handheld terminals (PDAs) with wireless communication capabilities, wireless modems, portable computers with wireless communication capabilities, imaging devices such as digital cameras with wireless communication capabilities, gaming devices with wireless communication capabilities, music storage and playback appliances with wireless communication capabilities, internet appliances capable of wireless internet access and browsing, as well as portable units or terminals integrating combinations of such functions. Additionally, the terminal may include machine-to-machine (M2M) terminals and machine-type communication (MTC) terminals / devices, but is not limited thereto. In this specification, the terminal may be referred to as an electronic device or simply a device.

[0096] An AP (102) is an entity that provides access to a distribution system (DS) via a wireless medium to an Associated Station (STA) connected to it. An AP may also be called a central controller, base station (BS), Node-B, base transceiver system (BTS), or site controller.

[0097] An exemplary coverage area (106) of an AP (102) capable of representing the basic service area (BSA) of a wireless communication network (100) is illustrated. The AP (102) periodically broadcasts beacon frames (beacon frames may be interchangeable with beacons) containing a basic service set identifier (BSSID) to enable any STA (104) within the wireless range of the AP (102) to be associated with or re-associated with the AP (102) to establish or maintain individual communication links (108) (or may be referred to as Wi-Fi links) with the AP (102). The AP (102) can provide access to external networks for various STAs (104) within the WLAN through individual communication links (108).

[0098] A single AP (102) and an associated set of STAs (104) may be referred to as a basic service set (BSS) managed by the individual AP (102). The BSS may be identified to users by a service set identifier (SSID), as well as to other devices by a BSSID, which may be the MAC address of the AP (102).

[0099] BSS can be classified into infrastructure BSS and independent BSS (IBSS). The BSS shown in Fig. 1 is an IBSS, and it is also possible to establish an infrastructure BSS (not shown). An infrastructure BSS includes one or more STAs and APs, and in principle, communication between non-AP STAs in an infrastructure BSS is carried out via an AP, but if a direct link is established between non-AP STAs, direct communication between non-AP STAs is also possible.

[0100] Multiple infrastructure BSSs can be interconnected via DS. Multiple BSSs connected via DS are called an extended service set (ESS). STAs included in an ESS can communicate with each other, and within the same ESS, STAs can move from one BSS to another while communicating seamlessly.

[0101] A DS is a mechanism that connects multiple APs; it does not necessarily have to be a network, and there are no restrictions on its form as long as it can provide a specified distribution service. For example, a DS can be a wireless network such as a mesh network, or it can be a physical structure that connects APs to each other.

[0102] Additionally, AP (102) and STA (104) may be referred to as AP-MLD (access point multi-link device) and STA-MDL, respectively. This may mean that AP and STA can support multi-link operation.

[0103] Below, an example of a hierarchical structure according to the 802.11 standard is described.

[0104] The 802.11 standard document develops MAC and PHY protocols corresponding to Wi-Fi wireless access technology. The Data Link Layer (DLL) includes the MAC sublayer, which is responsible for media access control. It receives packets from the upper layer, 802.1X Port Filtering, via the MAC_SAP interface, constructs them into IEEE 802.11 MAC frames, and transmits them to the physical layer. The physical layer includes the PLCP (Physical Layer Convergence Procedure) sublayer and the PDM (Physical Medium Dependent) sublayer. The PLCP sublayer is responsible for converting the IEEE 802.11 MAC frames constructed by the MAC sublayer into PLCP frames. The PLCP frames are then transmitted to the target terminal through the PMD sublayer.

[0105] Various management frames that manage Wi-Fi wireless access are not transmitted at the upper layers of 802.1X. Instead, these management frames are transmitted as requests and responses between Station Management Entities (SMEs) located within each terminal. An SME is a layer-independent entity that may exist within a separate management plane or appear to be off-the-side. For example, if an AP wants to configure a BSS, it instructs the transmission of beacons via the MLME_SAP interface, specifically the MLME-START.request and MLME-START.confirm primitives. If an STA wants to establish an association with the corresponding AP, it instructs the transmission of association Request / Response frames via the MLME-ASSOCIATE.request, MLME-ASSOCIATE.response, MLME-ASSOCIATE.confirm, and MLME-ASSOCIATE.indication primitives. Meanwhile, if you wish to set operational parameter values ​​related to the physical layer, the SME can set various physical layer parameter values ​​through the PLCP_SAP interface.

[0106] FIG. 2 is a drawing illustrating an example of the structure of an electronic device for performing a WLAN connection to which various embodiments of the present disclosure are applicable.

[0107] Referring to FIG. 2, the electronic device (200) may be connected to an AP (210), and the electronic device (200) may include a processor (230) and a communication module (220). The electronic device (200) may be the STA (104) of FIG. 1, in which case the electronic device (200) may be connected to the AP (210) as illustrated. Alternatively, the electronic device (200) may be the AP (102) of FIG. 1, in which case the electronic device may be connected to the STA (104) and / or another AP as illustrated in FIG. 1.

[0108] The communication module (220) can receive a communication signal from the outside or transmit a communication signal to the outside based on a Wi-Fi communication method (e.g., IEEE Std 802.11™). For example, the communication module (220) can operate based on Wi-Fi communication methods such as IEEE 802.11ac, 802.11ax, 802.11be, or 802.11bn, and in particular, IEEE 802.11be or 802.11bn supports a wider bandwidth, higher data throughput, and shorter latency compared to IEEE 802.11ax, thereby improving performance.

[0109] The communication module (220) may include a transceiver (224) for transmitting and receiving data with an external device and a communication processor (222) (e.g., a communication processor (not shown), or a short-range wireless communication module (e.g., a Wi-Fi chipset)). Depending on various embodiments, the communication module (220) may further include memory.

[0110] According to various embodiments, the transceiver (224) can convert a baseband transmission signal into a wireless signal or convert a received wireless signal into a baseband reception signal.

[0111] According to various embodiments, the communication module (220) may further include, in addition to the transceiver (224) and the communication processor (222), components for OFDM or OFDMA (orthogonal frequency division multiple access), such as a modulator, a digital-analog converter, a frequency converter, an A / D converter, an amplifier, and / or a demodulator.

[0112] According to various embodiments not shown, the electronic device (200) may be electrically connected to a communication module of the AP (210) and may include at least one antenna module that supports a communication protocol and / or frequency band supported by the communication module of the AP (210).

[0113] The communication processor (222) can control the transceiver (224) to form a communication connection with the AP (210). For example, the communication connection may include a Wi-Fi network. For example, the communication processor (222) can control the transceiver (224) to form a wireless connection with the AP (200) using a WLAN standard in the 2.4 GHz, 5 GHz, or 6 GHz band such as IEEE 802.11ac, 802.11ax, 802.11be, or 802.11bn. Alternatively, the communication processor (222) can control the transceiver (191) to form a wireless connection with the AP (210) using a WLAN standard in the 60 GHz band such as IEEE 802.11ad or 802.11ay. In addition, the method of communicating between the electronic device (200) and the AP (210) using a WLAN standard can be referred to as a communication method based on STA mode.

[0114] According to various embodiments, the processor (230) may include an application processor. The processor (230) may perform a specified operation of the electronic device (200) or control other hardware (e.g., a communication module (220)) to perform a specified operation.

[0115] According to various embodiments, the AP (210) may support the operation of transmitting packets to an external network and / or the operation of receiving packets from an external network based on a connection between a plurality of electronic devices (e.g., electronic device (200)) and an external network (e.g., the Internet, an external LAN, or a cellular network).

[0116] For example, the AP (210) may be a wireless router. The AP (210) may be a dedicated wireless router or a general-purpose device that supports mobile hotspot functions, and there are no limitations on its implementation. For example, the AP (210) may include the same components (e.g., a processor and / or a communication module) as the electronic device (200). Additionally, the AP (210) may transmit and receive data with an external device, such as a server. For example, the AP (210) may transmit at least some of the data received from the server to the electronic device (200).

[0117] If the electronic device (200) of FIG. 2 corresponds to the AP (102), the electronic device (200) may include a separate communication module for connection with an external network, although not shown. This communication module may be controlled by a processor (230) or by a separate processor. The separate communication module may include a transceiver and a processor, and may also include memory. Additionally, the electronic device (200) may include a separate antenna module or a wired connection device for connection with an external network.

[0118] FIG. 3 is a diagram illustrating an example of a link setup process of a general wireless LAN to which various embodiments of the present disclosure are applicable.

[0119] 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 discovery, authentication, association, and security setup processes of the link setup process can be collectively referred to as the association process.

[0120] Referring to FIG. 3, the STA (300) can perform a network discovery operation. The network discovery operation may include a scanning operation of the STA (300). That is, in order for the STA (300) to access a network, it must find a network that it can join. Before joining a wireless network, the STA (300) must identify a compatible network, and the process of identifying networks existing in a specific area is called scanning.

[0121] Scanning methods include active scanning and passive scanning. In active scanning, the STA (300) performing the scanning moves between channels and sends a probe request frame (322) to search for nearby APs and waits for a response. The responder sends a probe response frame (324) as a response to the probe request frame to the STA that sent the probe request frame. Here, the responder may be the AP or STA that last sent a beacon frame from the BSS of the channel being scanned. In FIG. 3, an example of a BSS that becomes the responder is shown where the AP (310) sends a beacon frame (320). In an IBSS, the responder is not constant because the STAs within the IBSS take turns sending beacon frames. For example, if an STA transmits a probe request frame on channel 1 and receives a probe response frame on channel 1, the STA can store the BSS-related information included in the received probe response frame and move to the next channel to perform scanning in the same way.

[0122] Scanning operations may be performed using a passive scanning method. In passive scanning, the STA performing the scanning detects beacon frames while switching between channels. A beacon frame is one of the management frames in IEEE 802.11, which announces the presence of a wireless network and is periodically transmitted to allow the scanning STA to find the wireless network and join it. Figure 3 illustrates an example of a BSS in which an AP (310) periodically transmits beacon frames (320) to an STA (300), and in an IBSS, STAs within the IBSS take turns transmitting beacon frames. When the scanning STA receives a beacon frame, it stores information about the BSS included in the beacon frame and records the beacon frame information in each channel while moving to another channel. When comparing active scanning and passive scanning, active scanning has the advantage of having less delay and power consumption than passive scanning.

[0123] After the STA (300) discovers the network, an authentication process may be performed. This authentication process may be referred to as the first authentication process to clearly distinguish it from the security setup operation (350) described later. The authentication process includes the STA (300) sending an authentication request frame (330) to the AP (310), and in response, the AP (310) sending an authentication response frame (332) to the STA (300). The authentication frame used in the authentication request / response corresponds to a management frame.

[0124] 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.

[0125] AP (310) can determine whether to allow authentication for the STA based on the information included in the received authentication request frame. AP (310) can provide the result of the authentication processing to the STA (300) through an authentication response frame.

[0126] After the STA is successfully authenticated, an association process can be performed. The association process includes the STA (300) sending an association request frame (340) to the AP (310), and in response, the AP (310) sending an association response frame (342) to the STA (300).

[0127] For example, the associated request frame may include information regarding various capabilities, beacon listen interval, SSID, supported rates, supported channels, RSN (robust security network), mobility domain, supported operating classes, traffic indication map broadcast request, interworking service capabilities, etc.

[0128] For example, an association response frame may include information related to various capabilities, status code, association ID (AID), support rate, enhanced distributed channel access (EDCA) parameter set, received channel power indicator (RCPI), received signal to noise indicator (RSNI), mobility domain, timeout interval (association comeback time), overlapping BSS scan parameters, TIM broadcast response, QoS map, etc.

[0129] This is a partial example of the information that may be included in the associated request / response frame, and it may be replaced with other information or additional information may be included.

[0130] Although not yet described, a security setup process can be performed after the STA is successfully associated with the network. The security setup process may be described as an authentication process through RSNA (robust security network association) requests / responses, and the authentication process (330) may be called the first authentication process, and the security setup process may also be called the authentication process.

[0131] The security setup process may include, for example, a private key setup process through a 4-way handshake via an EAPOL (extensible authentication protocol over LAN) frame, or may be performed according to a security method not defined in the IEEE 802.11 standard.

[0132] The following describes the Media Access Control Protocol provided by 802.11.

[0133] In wireless LAN systems based on IEEE 802.11, the basic access mechanism of a MAC is based on a distributed coordination function (DCF) utilizing the carrier sense multiple access with collision avoidance (CSMA / CA) method. There are two methods for detecting carriers in DCF: physical carrier sense and virtual carrier sense. The physical carrier sense method detects channel conditions at the physical layer and informs the MAC layer, while the virtual carrier sense method reserves a channel in advance by broadcasting the channel occupancy time to surrounding stations. An STA or AP that has secured a transmission channel records and transmits this channel occupancy time within an RTS and / or CTS or data frame; other STAs receiving this information determine that the channel is in use during this time and avoid channel occupancy contention, thereby avoiding collisions.

[0134] The physical carrier sensing method basically employs a listen before talk access mechanism, and according to this type of access mechanism, the AP and / or STA can perform a clear channel assessment (CCA) to sense the wireless channel, carrier, or medium for a predetermined time interval before starting transmission. The predetermined time interval is referred to as the inter-frame space (IFS) and may vary depending on the priority of the traffic to be transmitted. That is, priority can be determined by the length of the time interval, and packets with higher priority may have shorter time intervals.

[0135] The above IFS may include SIFS (short IFS), PIFS (priority IFS, PCF (point coordination function) IFS), DIFS (distributed (coordination function) IFS), AIFS (arbitration IFS), etc. SIFS is the shortest time interval and can be used primarily as a waiting time for control information. PIFS is a medium-length time interval and can be for packets of medium priority (PIFS = SIFS + 1 slot time). DIFS is the longest time interval compared to SIFS and PIFS, has a low priority, and can be used primarily as a waiting time to check channel usage (DIFS = SIFS + 2 slot time). That is, for example, an STA intending to perform transmission can listen to (or detect channel) the channel usage during the DIFS period.

[0136] If sensing results determine that the medium is in an idle status, the AP and / or STA begin transmitting a frame through the medium. Conversely, if the medium is detected to be in an occupied status, the AP and / or STA may not begin their own transmission but wait for a delay period (e.g., a random backoff period) for accessing the medium 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.

[0137] However, since this DCF method does not consider the priority between STAs, it has the problem of being difficult to support various forms of data transmission and QoS (Quality of Service); therefore, HCF (hybrid coordination function) was introduced. HCF is based on the aforementioned DCF and PCF (point coordination function). PCF refers to a polling-based synchronous access method that periodically polls all receiving APs and / or STAs so that they can receive data frames. HCF includes EDCA (enhanced distributed channel access), a contention-based channel access method, and HCCA (HCF controlled channel access), a contention-based method utilizing a polling mechanism. Furthermore, HCF includes a media access mechanism to enhance the QoS of the WLAN and can transmit QoS data during both the contention period (CP) and the contention-free period (CFP).

[0138] FIG. 4 is a drawing illustrating an example of a hidden node and an exposed node to which various embodiments of the present disclosure are applicable, and an example of an RTS and CTS for solving the problem of a hidden node and an exposed node.

[0139] Figure 4 (a) (400) is an example of a hidden node. When STA A and STA B are communicating and STA C has information to transmit, STA A is transmitting information to STA B, but when STA C performs carrier sensing before sending data to STA B, it can be determined that the medium is idle. This is because STA C may not be able to sense STA A's transmission (i.e., medium occupancy) at its location. In this case, a collision occurs because STA B receives information from STA A and STA C simultaneously. At this time, STA A can be considered a hidden node of STA C.

[0140] (b)(410) is an example of an exposed node. In a situation where STA B is transmitting data to STA A, STA C may have information to transmit to STA D. In this case, if STA C performs carrier sensing, it can determine that the medium is occupied due to the transmission by STA B. Accordingly, STA C must wait until the medium becomes idle, even if it has information to transmit to STA D. However, in reality, since STA A is outside the transmission range of STA C, the transmission from STA C and the transmission from STA B may not conflict from STA A's perspective, so STA C ends up waiting unnecessarily until STA B stops transmitting. In this case, STA C can be referred to as the exposed node of STA B.

[0141] In order to efficiently utilize the collision avoidance mechanism in the above situation, short signaling packets such as RTS (request to send) and CTS (clear to send) may be used. An STA intending to transmit data transmits an RTS to a STA intending to receive data, and the receiving STA that receives the RTS responds to the transmitting STA with a CTS frame. The RTS and / or CTS between the two STAs may cause surrounding STA(s) to overhear, thereby causing the surrounding STA(s) to consider whether to transmit information between the two STAs.

[0142] (c)(420) is an example of how to solve the hidden node problem. Assume that both STA A and STA C are trying to send data to STA B. When STA A sends an RTS to STA B, STA B sends a CTS to STA A. STA C, which overhears the RTS and CTS, delays its media access until the data transmission of STA A and STA B is finished, thereby avoiding collisions.

[0143] (d)(430) is an example of a method for solving the exposed node problem. STA B, which intends to send data to STA A, sends an RTS, and STA A, which is to receive the data, sends a CTS to respond to the RTS. In this case, if STA C receives only the RTS sent by STA B and does not receive the CTS sent by STA A, STA C can determine that STA A is outside the carrier sensing area of ​​STC C. In this case, STA C can determine that no collision will occur even if it sends data to another STA (e.g., STA D) and can send the data.

[0144] FIG. 5 is a drawing illustrating an example of a frame structure used in an IEEE 802.11 system to which various embodiments of the present disclosure are applicable.

[0145] The PPDU (physical layer protocol data unit) format can be configured to include the STF (short training field), LTF (long training field), SIG (signal) field, and data field. The most basic (e.g., non-HT (high throughput)) PPDU frame format can be configured to include only the L-STF (legacy-STF), L-LTF (legacy-LTF), SIG field, and data field.

[0146] STF can be used for frame timing acquisition, automatic gain control (AGC), diversity detection, and coarse frequency / time synchronization. LTF can be used for fine frequency / time synchronization and channel estimation. STF and LTF together can be referred to as the PLCP preamble, and the PLCP preamble can be described as a signal for synchronization and channel estimation in the OFDM physical layer.

[0147] The SIG field can be used to transmit control information for demodulation and decoding of the data field. The SIG field may include information regarding the data rate and data length. Additionally, the SIG field may include a parity bit, a SIG TAIL bit, etc.

[0148] 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 the descrambler at the receiver. The PSDU corresponds to the MPDU (mac protocol data unit) 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 state of 0. Padding bits may be used to adjust the length of the data field to a predetermined unit.

[0149] MPDUs are defined according to various MAC frame formats, and a basic MAC frame consists of a MAC header, a frame body, and a frame check sequence (FCS). A MAC frame is composed of an MPDU and can be transmitted or received through the PSDU of the data portion in the PPDU format.

[0150] The MAC header is defined as an area including a frame control field, a duration / ID field, an address 1 field, an address 2 field, an address 3 field, a sequence control field, an address 4 field, a QoS control field, and an HT control field.

[0151] The frame control field contains information about the corresponding MAC frame characteristics. The interval / identifier field can be implemented to have different values ​​depending on the type and subtype of the corresponding MAC frame.

[0152] Fields 1 through 4 of the address are used to indicate the BSSID, source address (SA), destination address (DA), transmitting address (TA) representing the transmitting STA address, and receiving address (RA) representing the receiving STA address.

[0153] The sequence control field is configured to include a sequence number and a fragment number. The sequence number may indicate the sequence number assigned to the corresponding MAC frame. The fragment number may indicate the number of each fragment of the corresponding MAC frame.

[0154] The QoS control field contains information related to QoS. The QoS control field may be included if the Subtype subfield indicates a QoS data frame. The HT control field contains control information related to HT and / or VHT transmission and reception techniques.

[0155] The frame body is defined as the MAC payload, contains the data to be transmitted from the upper layer, and has a variable size. For example, the maximum MPDU size can be 11,454 octets, and the maximum PPDU size can be 5.484 ms.

[0156] FCS is defined as the MAC footer and is used for error detection in MAC frames.

[0157] The first three fields (frame control field, interval / identifier field, and address 1 field) and the very last field (FCS field) constitute the minimum frame format and are present in all frames. Other fields may exist only in specific frame types.

[0158] The following describes the network allocation vector (NAV) used in wireless LAN networks.

[0159] As previously mentioned, the CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing, where the AP and / or STA directly senses the medium. Virtual carrier sensing is intended to compensate for problems that may occur in medium access, such as hidden node issues. For virtual carrier sensing, the MAC of a wireless LAN system may utilize NAV. NAV is a value that indicates to other APs and / or STAs the time remaining until the medium becomes available, provided that the AP and / or STA currently using or authorized to use the medium is using the medium. Therefore, the value set as NAV corresponds to the period during which the medium is scheduled to be used by the AP and / or STA transmitting the frame, and the STA receiving the NAV value is prohibited from accessing the medium during that period. NAV can be set, for example, based on the value of the duration field in the MAC header of the frame.

[0160] FIG. 6 is a drawing illustrating an example of a NAV setting to which various embodiments of the present disclosure are applicable.

[0161] Referring to FIG. 6, the source STA (source STA, 600) transmits an RTS frame after DIFS, and the destination (610) transmits a CTS frame after SIFS. The destination STA designated as the recipient via the RTS frame does not set the NAV. Some of the remaining STAs (620) receive the RTS frame and set the NAV (630), while others receive the CTS frame and set the NAV (640).

[0162] If a CTS frame (e.g., PHY-RXSTART.indication primitive) is not received within a certain period from the time when an RTS frame is received (e.g., when a MAC receives the PHY-RXEND.indication primitive corresponding to the RTS frame), STAs that set or updated the NAV through the RTS frame may reset the NAV (e.g., 0). The certain period may be (2*aSIFSTime + CTS_Time + aRxPHYStartDelay + 2*aSlotTime). CTS_Time may be calculated based on the length and data rate of the CTS frame indicated by the RTS frame. The above certain period may be the NAVTimeout period.

[0163] In FIG. 6, for convenience, NAV setting or updating is exemplified through an RTS frame or a CTS frame, but NAV setting / resetting / updating may also be performed based on the interval field of various other frames, such as non-HT PPDU, HT PPDU, VHT PPDU, or HE PPDU (for example, the interval field within the MAC header of a MAC frame).

[0164] In addition, 802.11ax introduced basic NAV and intra-BSS NAV. Basic NAV is always set (mandatory) to NAV based on frames transmitted by APs or STAs other than itself, while intra-BSS NAV is optionally set to NAV based on frames transmitted by the BSS to which it belongs. An AP or STA can access the medium when both NAV timers have expired (or after the NAV time interval has elapsed).

[0165] The following describes TXOP. TXOP (transmission opportunity) was newly introduced in 802.11e MACs to guarantee QoS and increase channel utilization. To guarantee QoS, TXOP can be used to allocate an opportunity for priority transmission when two or more packets belong to the same AC (access category).

[0166] FIG. 7 is a drawing illustrating an example of a TXOP to which various embodiments of the present disclosure are applicable.

[0167] STAs participating in QoS transmission can obtain a TXOP that allows them to transmit traffic for a certain period using two channel access methods, such as EDCA and HCCA. TXOP acquisition is possible by succeeding in EDCA contention or receiving a QoS CF-Poll (Contention-Free Poll) frame from an AP; the former is called an EDCA TXOP, and the latter is called a Polled TXOP. In this way, the concept of a TXOP can be used to grant a certain amount of time for any STA to transmit a frame, or to forcibly limit the transmission time.

[0168] The transmission start time and maximum transmission time of a TXOP are determined by the AP, and this is notified to the STA by a beacon frame in the case of an EDCA TXOP, and by a QoS CF-Poll frame in the case of a Polled TXOP.

[0169] NAV can be understood as a type of timer designed to protect the TXOP of a transmitting STA (e.g., a TXOP holder). An STA can protect the TXOPs of other STAs by not performing channel access during the period when the NAV set for it is valid. In current wireless LAN systems, the TXOP duration is set via the duration field of the MAC header. That is, the TXOP holder and the TXOP responder (e.g., an Rx STA) include all the TXOP information necessary for the transmission and reception of frames in the duration field of the frames being exchanged between them. Third-party STAs that are not the TXOP holder or TXOP responder (e.g., third-party STAs) check the duration field of the frames exchanged between the TXOP holder and the TXOP responder, and delay channel usage until the NAV period expires by setting or updating the NAV.

[0170] The 802.11be standard is described below. Also known as EHT (extremely high throughput), 802.11be operates across the 2.4, 5, and 6 GHz bands. It is being developed to provide low latency and high network throughput by introducing a 320 MHz wide bandwidth, 4096QAM, multiple resource units (RUs), and multi-link operation (MLO), offering speeds up to 46 Gbps—4.8 times faster than WiFi 6. Specifically, 802.11be provides a 320 MHz wide bandwidth in the 6 GHz band and can transmit data via MU-MIMO, which offers 16 spatial streams in both uplink and downlink. It also achieves high transmission efficiency by adopting 4096QAM. Furthermore, it features enhanced spectrum efficiency by flexibly performing spectrum resource scheduling through multiple RUs, and the ability to simultaneously transmit and receive data across various frequency bands and channels through multi-link operation.

[0171] The following describes TXOP sharing. TXOP sharing is a technology defined in 802.11be, based on the concept of an AP transferring remaining TXOP resources to a STA within a BSS after using the TXOPs it has acquired. An AP can transfer TXOPs to a STA using a multi-user RTS (MU-RTS) TXOP sharing (TXS) trigger frame (TF), specifically the MU-RTS TXS TF, and the STA receiving the TXOP is indicated within the MU-RTS TXS TF. Recently, TXOP sharing between APs has been under research. Through TXOP sharing between APs, an AP holding TXOPs can share the remaining TXOPs with an adjacent AP after using them for traffic processing within its BSS, thereby efficiently utilizing frequency and space resources to increase network throughput and reduce latency. TXOP sharing between APs can be referred to as AP TXOP sharing or Coordinated TDMA (Co-TDMA). An AP occupying a TXOP may share its TXOP with an AP expected to process traffic; in this case, the AP sharing the TXOP may be referred to as a sharing AP or coordinating AP, and the AP receiving the shared TXOP may be referred to as a shared AP or coordinated AP. Hereinafter, a TXOP shared / assigned / transferred from a sharing AP to a shared AP may be referred to as a shared TXOP. This is for convenience of explanation and the present disclosure is not limited to these specific names.

[0172] In addition to Co-TDMA, transmission methods that improve efficiency and / or reliability through the coordination of multiple APs (multi-AP, M-AP) are being studied. Examples of such multi-AP (M-AP) coordination schemes include Co-JT (coordinated joint transmission), Co-BF (coordinated beamforming), Co-SR (coordinated spatial reuse), Co-OFDMA (coordinated orthogonal frequency division multiple access), and Co-R-TWT (coordinated restricted target wake time). Furthermore, a set of APs capable of performing such M-AP coordinate (Multi-Access Point Coordination; MAPC) operations can be referred to as an M-AP set.

[0173] Next, we will describe the overlapping basic service set (OBSS). As the number of users increases, the performance of existing wireless LAN networks, such as transmission rates, decreases significantly. This is because wireless LAN systems fundamentally utilize the CSMA / CA method, which corresponds to time division access control; therefore, when an adjacent network is detected, the frequency resources of the same band are shared for the duration of the adjacent network's activity.

[0174] Currently, it is common for multiple APs to operate in specific areas, and in such cases, wireless LAN network performance degradation occurs due to coverage overlap between APs. This is because the APs of each BSS and the STAs connected to them are affected by signals from adjacent BSSs, leading to interference and a reduction in transmission rates caused by collisions between signals transmitted simultaneously. BSSs that can affect signal transmission in this way (or have overlapping coverage) can be referred to as overlapping BSSs (OBSS). To address this problem, interference avoidance techniques are being researched, such as dividing the bandwidth available to each user so that it does not overlap or performing channel switching to unused channels, as well as interference alignment techniques that minimize the impact of interference even when using the same bandwidth.

[0175] According to one embodiment of the present disclosure, in M-AP operation, an OFDMA (orthogonal frequency division multiple access) based random access method for a plurality of APs may be provided. Hereinafter, in the description of one embodiment of the present disclosure, the OFDMA-based random access for a plurality of APs is referred to as UORA (uplink OFDMA-based random access) or AP UORA, but this is for convenience of explanation and the present disclosure is not limited to these specific names.

[0176] According to one embodiment of the present disclosure, a method may be provided for sharing information necessary for M-AP operation through UORA between APs. For example, a method may be provided for one AP to receive information / response from an AP that has not generated an M-AP agreement and / or an AP that has generated an M-AP agreement.

[0177] According to one embodiment of the present disclosure, a method may be provided for exchanging OFDMA contention windows for AP UORA operations when consensus is generated between APs. For example, information regarding OFDMA contention windows may be exchanged during consensus between APs.

[0178] In one embodiment of the present disclosure, for a specific AP, a coordinated AP (cooperative AP) may mean an AP that has formed a MAPC agreement with said AP. An uncoordinated AP (non-cooperative AP) may mean an AP that has not formed a MAPC agreement with said AP.

[0179] In an M-AP operation to which an embodiment of the present disclosure is applicable, the TXOP owner AP (TXOP owner AP, sharing AP, coordinating AP) may announce in an initial control frame (ICF) transmitted at the start of the TXOP an intention to share at least a portion of the TXOP's time resources for Co-TDMA operation. The ICF is a frame transmitted to poll one or more STAs to determine whether one or more STAs are eligible or willing to participate during the TXOP. For example, the ICF may be a Buffer Status Report Poll (BSRP) trigger frame, but the present disclosure is not limited thereto. If the ICF is a BSRP trigger frame, the corresponding initial control response (ICR) may be a Buffer Status Report (BSR) or / and a Multi-Station Block Ack. The AP that owns the TXOP polls the ICF to APs that may share the TXOP to determine the AP's interest. An AP that is polled from a sharing AP in the ICF transmitted as part of the M-AP operation can be called a polled AP.

[0180] In one embodiment of the present disclosure, a sharing AP that transmits a trigger frame as part of an M-AP coordinate transmission scheme can identify a shared AP through the AP ID in the AID12 field of the User Info field of the frame.

[0181] Unless specifically stated otherwise, in the description of an embodiment of the present disclosure, "greater than" may be replaced with "greater than" and "greater than" may be replaced with "greater than". Unless specifically stated otherwise, in the description of an embodiment of the present disclosure, "less than" may be replaced with "less than" and "less than" may be replaced with "less than".

[0182] FIG. 8 illustrates an example of communication between APs to which an embodiment of the present disclosure is applicable. FIG. 8 illustrates an example of M-AP related operation between a sharing AP, candidate AP1, and candidate AP2. A sharing AP can form an intra-BSS with one or more STAs.

[0183] In the polling phase, the sharing AP may transmit an ICF for polling after a backoff period. Through the ICF for polling, the sharing AP may announce its intention to share a portion of the time resources of the TXOP it has acquired with other APs. The ICF for polling may be intended to poll one or more APs (e.g., Candidate AP1, Candidate AP2) to confirm their willingness to participate (or their willingness to be allocated time resources). The sharing AP may identify each polled AP by setting the AID12 subfield of the User Info field of the polled AP within the trigger frame to the AP ID of the polled AP.

[0184] In the polling phase, the polled AP may respond to the corresponding ICF. For example, the response may be transmitted via an ICR (initial control response). If Candidate AP1 is willing to participate, it may respond with Accept from the ICF after a certain frame interval (e.g., SIFS). If Candidate AP2 is not willing to participate, it may respond with Reject from the ICF after a certain frame interval (e.g., SIFS). Additionally, one or more STAs associated with the sharing AP may also respond to the corresponding ICF.

[0185] After a certain frame interval (e.g., SIFS) from the response, the sharing AP can perform intra-BSS frame exchange and can perform frame exchange with one or more STAs within the intra-BSS.

[0186] After a certain frame interval (e.g., SIFS) from the frame exchange, M-AP operations (e.g., Co-TDMA, Co-BF (coordinated beamforming), Co-SR) can be performed between the candidate AP1 that responded to the acknowledgment and the sharing AP. For example, in the case of Co-TDMA, the sharing AP may allocate at least a portion of the time of the acquired TXOP to candidate AP1.

[0187] In the polling of the sharing AP as described above, in certain cases, polling all candidate APs at once may be inefficient or impossible. For example, when polling multiple candidate APs and / or associated non-AP STAs simultaneously, if a small-sized RU (resource unit) is used in terms of frequency resources, a longer time is required to transmit the response (ICR), which can increase the overhead for the response. Conversely, if a large-sized RU is used, the number of RUs may become insufficient.

[0188] The present disclosure proposes a UORA operation for an AP in an M-AP operation to solve these problems. For example, assuming that a small number of APs among all candidate APs intend to participate in the M-AP in a TXOP, a UORA can be an effective solution. In areas where APs are densely installed, a single AP may have 10 or more candidate APs, but since it is expected that the number of APs to perform operations related to the M-AP cooperative transmission scheme within a single TXOP will be small, such as 1 to 3, the above assumption may be valid.

[0189] FIG. 9 illustrates an example of a UORA operation to which an embodiment of the present disclosure is applicable.

[0190] In IEEE 802.11ax, UORA is defined as a random access mechanism for a non-AP HE (high-efficiency) STA to participate in uplink OFDMA transmission on one or more designated resource units (RUs). In UORA, an AP may transmit a basic trigger frame containing one or more RUs for random access, a BQRP (bandwidth query report poll) trigger frame, and / or a BSRP (beamforming report poll) trigger frame. An AP may assign an RA-RU to an associated STA by setting the AID12 of the User Info Field to 0, and may assign an RA-RU to an unassociated STA by setting the AID12 to 2045.

[0191] Each non-AP STA can maintain an OFDMA contention window (OCW) and an OFDMA random access backoff (OBO). If the number of available RA-RUs is greater than or equal to the OBO, the non-AP STA can randomly select one of the RA-RUs and perform a transmission on the selected RA-RU. If the number of available RA-RUs is not greater than or equal to the OBO, the STA decreases the OBO by the number of available RA-RUs. The STA decreases the OBO according to the number of available RA-RUs, and accordingly, when the value of the OBO becomes 0, it can randomly select one of the RA-RUs and perform a transmission on the selected RA-RU; otherwise, it can maintain the decreased OBO until the next trigger frame is received.

[0192] In FIG. 9, STA1 (associated with AP, AID=5), STA2 (associated with AP, AID=7), STA3 (unassociated), and STA4 (associated with AP, AID=3) are exemplified. Before the trigger frame is transmitted by the AP, STA1, STA2, STA3, and STA4 have initial OBO (OFDMA back-off) values ​​of 3, 5, 4, and 2, respectively. These may be (randomly) selected within the OFDMA contention window (values ​​from 0 to OCW). In the trigger frame, one or more RUs may be indicated for random access (RA-RU), the RA-RU corresponding to AID0 may be for the STA associated with the AP, and the RA-RU corresponding to AID 2045 may be for the STA not associated with the AP.

[0193] When trigger frame 1 is received, STA4, which is associated with the AP and has a pending frame for the AP, is allocated a dedicated RU. That is, RU6, which corresponds to STA4's AID=3 in trigger frame 1, is interpreted as being for STA4. STA4 does not compete for the RA-RU, but instead can transmit the pending frame from RU6 after SIFS from trigger frame 1. Multi-STA BlockAck can be transmitted and received from the pending frame after SIFS.

[0194] When trigger frame 1 is received, STA1 and STA2, which are associated with AP and have pending frames for AP, decrement their respective OBO counters by the number of available RA-RUs specified in the trigger frame (i.e., 3 RA-RUs for the associated STA, 3 RA-RUs corresponding to AID 0). As STA1 decrements its OBO counter, the OBO counter of STA1, which had an initial OBO counter of 3, is reduced to 0; therefore, STA1 can transmit a pending frame after SIFS from trigger frame 1 on a randomly selected RU (e.g., RU2) from the set of available RUs (i.e., RU1, RU2, RU3). Multi-STA BlockAck after SIFS can be transmitted and received from the pending frame. As STA2 decreases the OBO counter, the OBO counter of STA2, which has an initial OBO counter of 5, is reduced to a non-zero value (2), so STA2 can maintain a new OBO counter (2) until it receives a subsequent trigger frame for the RA-RU for the associated STA.

[0195] When trigger frame 1 is received, STA3, which is not associated with AP but has a pending frame for AP, decreases its OBO counter by the number of available RA-RUs indicated in the trigger frame (i.e., 2 RA-RUs for the unassociated STA, 2 RA-RUs corresponding to AID 2045). As STA3 decreases its OBO counter, the OBO counter of STA3, which had an initial OBO counter of 4, is reduced to a non-zero value (2), so STA2 can maintain the new OBO counter (2) until it receives a subsequent trigger frame for RA-RUs for the unassociated STA.

[0196] After transmitting the HE TB (trigger-based) PPDU in response to trigger frame 1, if STA4 has a pending additional frame for AP, STA4 may retain the initial OBO value (2) until it receives a subsequent trigger frame for RA-RU for the associated STA. Additionally, if STA1 has a pending additional frame for AP, STA1 may arbitrarily select a new OBO value (e.g., 4).

[0197] When trigger frame 2 is received, STA1, STA2, and STA4 each decrease their respective OBO counters by the number of available RA-RUs specified in the trigger frame (i.e., 2 RA-RUs for the associated STA, 2 RA-RUs corresponding to AID 0). Consequently, since the OBO counters of STA2 and STA4 have been reduced to 0, both STA2 and STA4 can transmit pending frames from any selected RU. For example, STA2 can randomly select RU2 to transmit its pending frame after SIFS from trigger frame 2, and STA4 can randomly select RU1 to transmit its pending frame after SIFS from trigger frame 2. Multi-STA BlockAck can be transmitted or received from pending frames after SIFS. The STA among STA2 and STA4 that has additional pending frames for the AP can randomly select a new OBO value. Since the OBO counter of STA1 has been reduced to a non-zero value (2), STA1 can maintain the new OBO value (2) until it receives a subsequent trigger frame for the RA-RU for the associated STA.

[0198] When trigger frame 2 is received, STA3 decreases its respective OBO counter by the number of available RA-RUs specified in the trigger frame (i.e., 2 RA-RUs for unassociated STAs; 2 RA-RUs corresponding to AID 2045). Accordingly, since STA3's OBO counter has been reduced to 0, STA3 can transmit a pending frame after SIFS from trigger frame 2 at any selected RU (e.g., RU3). A Multi-STA BlockAck after SIFS can be transmitted or received from the pending frame.

[0199] Unless specifically otherwise noted in the description of one embodiment of the present disclosure, the UORA operation of the non-AP STA described above may also be applied to the UORA operation of the AP in the M-AP operation according to one embodiment of the present disclosure. Except as specifically otherwise noted in the description of one embodiment of the present disclosure, the UORA operation of the non-AP STA described above may be used as the operation of the AP in the AP UORA.

[0200] FIG. 10 shows an example of a User Info field format according to one embodiment of the present disclosure.

[0201] Referring to FIG. 10, the User Info field may include an AID12 subfield (12 bits, B0 to B11), an RU Allocation subfield (8 bits, B12 to B19), a UL FEC Coding Type subfield (1 bit, B20), a UL HE-MCS (High Efficiency Modulation and Coding Scheme) subfield (4 bits, B21 to B24), a UL DCM (Dual Carrier Modulation) subfield (1 bit, B25), an SS (Spatial Stream) Allocation / RA-RU (Random Access Resource Unit) Information subfield (6 bits, B26 to B31), a UL Target Receive Power subfield (7 bits, B32 to B38), a Reserved subfield (1 bit, B39), and a Trigger Dependent User Info subfield (variable).

[0202] According to one embodiment of the present disclosure, one or more AID12 values ​​for the UORA of the AP may be assigned / defined in the M-AP operation. As described above, the AP may assign an RA-RU to an associated STA by setting the AID12 of the User Info Field to 0, and may assign an RA-RU to an unassociated STA by setting the AID12 to 2045. Here, the AID12 may be set to a specific value for the UORA of the AP in the M-AP operation. Unless specifically otherwise stated in the description of one embodiment of the present disclosure, AID may be understood as AID12.

[0203] Table 1 shows an example of an AID12 subfield.

[0204] [Table 1]

[0205]

[0206] Referring to Table 1, a value of 0 in the AID12 subfield may indicate that the User Info field allocates one or more RA-RUs for the associated STA. A value of 1 to 2007 in the AID12 subfield may indicate that the User Info field is addressed to the associated STA having the same AID as the value in the AID12 subfield. A value of 2045 in the AID12 subfield may indicate that the User Info field allocates one or more RA-RUs for an unassociated STA. A value of 2046 in the AID12 subfield may indicate an unallocated RU. Since the AID12 subfield indicates the start of the padding field, a value of 4095 in the AID12 subfield of the User Info field may not be allowed. 2008 to 2044 and 2047 to 4094 may be reserved.

[0207] According to one embodiment of the present disclosure, one or more of the reserved values ​​of the AID12 subfield may be used as values ​​for the UORA of the AP in M-AP operation. One or more values ​​of 2008 to 2044 and / or one or more values ​​of 2047 to 4094 may be defined / used as values ​​for the UORA of the AP in M-AP operation. Being one or more of the values ​​of 2008 to 2044 and / or one or more of 2047 to 4094 of the AID12 subfield may indicate that the User Info field is for the UORA operation of the AP in M-AP operation.

[0208] According to one embodiment of the present disclosure, different values ​​of the AID12 subfield may be used depending on different options or conditions related to the UORA operation of the AP in M-AP operation. Values ​​of the AID12 subfield may be defined for each option, and options may be distinguished according to the assigned values ​​of the AID12 subfield. A specific value among 2008 to 2044 and 2047 to 4094 of the AID12 subfield may indicate that the User Info field is for an option related to the UORA operation of the AP in M-AP operation (an option corresponding to a specific value) (or an RA-RU for a device (AP) corresponding to said option). Options may include at least some of the following, which are exemplary and are not limited thereto.

[0209] - Option 1: An AP that has not established M-AP coordinates (uncoordinated AP). The specific value of the AID12 corresponding to this option indicates that the corresponding RU is the RA-RU for the uncoordinated AP. An AP that has not established M-AP coordinates can perform UORA using the RU corresponding to the AID12 as the RA-RU.

[0210] - Option 2: Uncoordinated AP with LL (low latency) traffic. The specific value of AID12 corresponding to this option indicates that the corresponding RU is an RA-RU for an uncoordinated AP with LL traffic. An uncoordinated AP with LL traffic can perform UORA by using the RU corresponding to the AID12 as an RA-RU.

[0211] - Option 3: AP that has established M-AP coordinates (coordinated AP / all coordinated APs). The specific value of the AID12 corresponding to this option indicates that the corresponding RU is the RA-RU for the coordinated AP. An AP that has established M-AP coordinates can perform UORA using the RU corresponding to the AID12 as the RA-RU.

[0212] - Option 4: A coordinated AP that has traffic corresponding to a specific AC (access category) and / or a specific TID (traffic identifier) ​​and / or traffic of higher priority than a specific UP (user priority) (e.g., when UP is greater than 5). The specific value of AID12 corresponding to this option indicates that the corresponding RU is an RA-RU for a coordinated AP that has traffic corresponding to a specific AC and / or a specific TID and / or traffic of higher priority than a specific UP.

[0213] - - AC (access category) is a label for the common set of enhanced distributed channel access (EDCA) parameters that are used by a quality-of-service (QoS) station (STA) to contend for the channel in order to transmit medium access control (MAC) service data units (MSDUs) with certain priorities. For example, traffic corresponding to AC_VO may have a higher priority than traffic corresponding to other ACs (e.g., a combination of one or more of AC_VI, AC_BE, and AC_BK). Or, traffic corresponding to a combination of AC_VO and AC_VI may have a higher priority than traffic corresponding to other ACs (e.g., a combination of one or more of AC_VI, AC_BE, and AC_BK). As described above, a value of AID12 can be defined / assigned for traffic corresponding to a specific AC and / or for a coordinated AP having a higher priority than traffic corresponding to a specific AC, and the coordinated AP having a higher priority than traffic corresponding to a specific AC and / or traffic corresponding to a specific AC can perform UORA by using the RU corresponding to the AID12 as the RA-RU.

[0214] - - UP (user priority) is a value associated with an MSDU that indicates how the MSDU should be handled. UP can have values ​​from 0 to 7 and corresponds to priorities from lowest to highest in the order of 1, 2, 0, 3, 4, 5, 6, 7. UP=1, 2 can be mapped to AC_BK, UP=0, 3 can be mapped to AC_BE, UP=4, 5 can be mapped to AC_VI, and UP=6, 7 can be mapped to AC_VO. As described above, an AID12 value can be defined / assigned for a coordinated AP having a value greater than or equal to a specific UP and / or traffic greater than or equal to the priority of a specific UP, and a coordinated AP having a value greater than or equal to a specific UP and / or traffic greater than or equal to the priority of a specific UP can perform UORA by using the RU corresponding to the AID12 as an RA-RU.

[0215] - - TID (traffic identifier) ​​is one of the identifiers that a higher-level entity can use to distinguish MSDUs for MAC entities that support QoS within MAC data services. There may be 16 possible TID values ​​(0 to 15), and when EDCA is used, values ​​0 to 7 are used as TC (traffic category), and when HCCA (HCF Controlled Channel Access) is used, values ​​8 to 15 are used as TS (traffic stream). As described above, AID12 values ​​can be defined / assigned for a coordinated AP having a value greater than or exceeding a specific TID and / or traffic greater than or exceeding the priority of a specific TID, and a coordinated AP having a value greater than or exceeding a specific TID and / or traffic greater than or exceeding the priority of a specific TID can perform UORA by using the RU corresponding to the AID12 as the RA-RU.

[0216] - Option 5: A coordinated AP having a queue length (corresponding to the amount of buffered traffic for the AC) for the AC indicated in the User Info field, which is greater than a specific value (e.g., 2048 octets). The specific value of the AID12 corresponding to this option indicates that the corresponding RU is the RA-RU for the coordinated AP having a queue length greater than the specific value. The coordinated AP having a queue length greater than the specific value can perform UORA using the RU corresponding to the AID12 as the RA-RU.

[0217] - Option 6: A coordinated AP with traffic having a delay bound (and / or an allowable maximum delay) of less than a specific value (e.g., 20 ms). The specific value of the AID12 corresponding to this option indicates that the corresponding RU is the RA-RU for the coordinated AP with traffic having that delay bound. The coordinated AP with traffic having that delay bound may perform a UORA using the RU corresponding to the AID12 as the RA-RU.

[0218] According to one embodiment of the present disclosure, specific conditions / constraints for AP UORA operation may be proposed. These may be for the efficient operation of AP UORA. One or more combinations of the following specific conditions / constraints may be applied.

[0219] According to one embodiment of the present disclosure, a STA participating in a UORA may transmit an acknowledgment response if it wins the competition. For a STA participating in the competition for a UORA, transmitting an acknowledgment response may be permitted, but transmitting a rejection response may not be permitted. That is, a rejection response may not be transmitted through any connection. This may be intended to prevent a collision, as the possibility of collision may increase if a rejection response is transmitted. For example, both a STA that did not win the competition and an AP that has no intention of participating in the M-AP operation may not transmit a rejection response.

[0220] Here, winning the competition means a competition within the UORA where the value of a specific AP's OBO counter is decremented to 0 before the value of another AP's OBO counter and / or consequently, the corresponding RU (RA-RU) can transmit an acknowledgment response. An AP that does not win the competition may retain an OBO counter decremented to a non-zero value and, for example, may use that decremented OBO counter when joining the next AP UORA. An OBO counter decremented to a non-zero value is retained until joining the next AP UORA.

[0221] According to one embodiment of the present disclosure, a sharing AP may not be allowed to assign all RUs as RA-RUs in a polling ICF. For a polling ICF, it may be allowed for some of the RUs to be assigned as RA-RUs. At least one of the RUs may not be assigned as RA-RU. This may be to prevent the sharing AP from losing a TXOP if none of the candidate APs respond, such as when the candidate APs fail to win the competition and / or have no intention of participating in the M-AP operation.

[0222] According to one embodiment of the present disclosure, in a polling ICF, at most one RA-RU may be allocated per AID for an uncoordinated AP. In a polling ICF, one or more AIDs for an uncoordinated AP may be included, but the RU corresponding to each AID may not exceed one. This may be taken into account that when an ICR from an uncoordinated AP is successfully received by a RU, the sharing AP may instruct the uncoordinated AP to use the AID value used for M-AP operation. This will be explained in more detail with reference to FIG. 11.

[0223] FIG. 11 illustrates an example of communication between APs according to one embodiment of the present disclosure. FIG. 11 illustrates an example of M-AP related operation between a sharing AP, a coordinated AP, and an uncoordinated AP. In FIG. 11, it is exemplified that AID12 = 2048 indicates that the corresponding RU is an RA-RU for the uncoordinated AP (Option 1), and AID12 = 2049 indicates that the corresponding RU is an RU for the coordinated AP.

[0224] The sharing AP can transmit an ICF for polling after a backoff period. The ICF includes multiple User Info fields, and the AID12 of a specific User Info field can be set to 2048, and the AID12 of another specific User Info field can be set to 2049.

[0225] If the uncoordinated AP is willing to participate, the uncoordinated AP may send an acknowledgment response from the ICF via UORA (when the OBO counter is decremented to 0) after a specific IFS (e.g., SIFS) from the RU corresponding to AID12=2048. If the coordinated AP is not willing to participate, the coordinated AP may send a rejection response. Since a RU has been designated and assigned to the coordinated AP, the coordinated AP can send a response without contention and can send an acknowledgment response or a rejection response.

[0226] After a certain frame interval (e.g., SIFS) from the response, the sharing AP can perform intra-BSS frame exchange.

[0227] After a certain frame interval (e.g., SIFS) from the frame exchange, the sharing AP can share / transfer the TXOP by sending a MU-RTS TXS TF (multi-user request to send TXOP sharing trigger frame).

[0228] The MU-RTS TXS TF may include the AID of the AP that will share / transfer the TXOP. Here, in the case of a coordinated AP, even if multiple coordinated APs transmit ICRs from multiple RUs corresponding to the same AID, the sharing AP can distinguish multiple coordinated APs based on other information within the ICR (e.g., AP ID, MAC address, etc.). On the other hand, in the case of an uncoordinated AP, if multiple coordinated APs transmit ICRs from multiple RUs corresponding to the same AID, it may be difficult for the sharing AP to distinguish them. Accordingly, as described above, the present disclosure proposes that for an uncoordinated AP in a polling ICF, at most one RA-RU is allocated per AID. In the example of FIG. 11, as described above, the number of RUs corresponding to AID12=2048 in the ICF may be at most one. The Sharing AP can transmit a MU-RTS TXS TF containing an AID set to the value of the AID corresponding to the RU that received the response (2048 in the example of FIG. 11).

[0229] After a certain frame interval (e.g., SIFS) from the MU-RTS TXS TF, the uncoordinated AP that sent the acknowledgment can send a CTS (clear to send). After a certain frame interval (e.g., SIFS) from the CTS, the uncoordinated AP that sent the acknowledgment can perform intra-BSS frame exchange within the transferred TXOP.

[0230] According to one embodiment of the present disclosure, a method for determining information / parameters to support AP UORA may be provided.

[0231] Current standard documents do not define UORA behavior for APs. Accordingly, APs do not maintain OCW and / or OBOs. Therefore, a method is required to support UORA behavior for APs. According to one embodiment of the present disclosure, a method may be provided for determining information / parameters to support AP UORA. For example, a method for a coordinated AP and a method for an uncoordinated AP may be provided separately.

[0232] FIG. 12 illustrates an example of a UORA parameter set element format and an OCW range field format according to one embodiment of the present disclosure. A method for a coordinated AP is described with reference to FIG. 12.

[0233] Referring to FIG. 12, the UORA parameter set element format may include an Element ID (1 octet) subfield, a Length (1 octet) subfield, an Element ID Extension (1 octet) subfield, and a plurality of OCW Range subfields (1 octet each).

[0234] The Element ID subfield is intended to identify the type of IE (information element), and the Element ID Extension subfield is an extension field of the Element ID subfield that can be used in conjunction with the Element ID subfield to indicate additional types of IE. An Element is identified by the Element ID subfield, or by the Element ID subfield and the Element ID Extension subfield, and the mapping relationship between the Element ID subfield and the Element, as well as the mapping relationship between the Element ID subfield and the Element ID Extension subfield and the Element, can be predefined.

[0235] The Length subfield can indicate the number of octets within an Element, excluding the Element ID subfield and the Length subfield.

[0236] The OCW Range subfield may indicate the minimum and maximum values ​​of the OCW. The OCW Range subfield may include EOCWmin (B0 to B2, 3 bits), EOCWmax (B3 to B5, 3 bits), and reserved bits (B6 to B7, 2 bits). EOCWmin is intended to indicate the minimum value of the OCW for the transmission of an initial PPDU (e.g., HE TB PPDU) using a UORA, where OCWmin = 2 EOCWmin The minimum value of OCW, OCWmin, is identified based on -1. EOCWmax is intended to indicate the maximum value of OCW for UORA, so OCWmax = 2 EOCWmax The maximum value of OCW, OCWmax, is identified based on -1. An OBO counter can be identified between OCWmin and OCWmax (i.e., OCW).

[0237] According to one embodiment of the present disclosure, a UORA parameter set element may include a plurality of OCW Range subfields so that different OCW ranges may be used for different AID settings. Here, one OCW range may correspond to one or more AID settings.

[0238] According to one embodiment of the present disclosure, the correspondence between an AID setting and an OCW range can be distinguished by a reserved field of the OCW Range field format. The relationship between the setting of the reserved bit and the AID setting can be predefined. For example, if AID12 is between 2008 and 2020, it may correspond to an OCW Range field where the reserved field is 0, and if AID12 is between 2021 and 2040, it may correspond to an OCW Range field where the Reserved field is 1.

[0239] According to one embodiment of the present disclosure, UORA parameter set elements may be exchanged between APs to enable a UORA for a Coordinated AP. For example, UORA parameter set elements may be exchanged during the MAPC agreement establishment and / or parameter negotiation process. For example, UORA parameter set elements may be included in a request frame or in both a request frame and a response frame.

[0240] According to one embodiment of the present disclosure, when UORA parameter set elements are not exchanged, a default OCW value may be used. A default UORA parameter set element may be defined, and a default OCW value may be identified based thereon. In other words, a defined default OCW value may be used, and it may be understood that the default OCW value is changed / updated according to the exchange of UORA parameter set elements between APs.

[0241] According to one embodiment of the present disclosure, in order to enable a UORA for an uncoordinated AP, a basic UORA parameter set element may be defined. A basic UORA parameter set element may be defined, and based thereon, a basic OCW value may be identified, and the uncoordinated AP may use / maintain the basic OCW value.

[0242] Hereinafter, examples of operation according to various embodiments of the present disclosure are described with reference to the drawings. The contents described in the various embodiments of the present disclosure described above may apply to the following description. The following examples are for understanding the various embodiments of the present disclosure, and the present disclosure is not limited to the following examples.

[0243] FIG. 13 illustrates an example of communication between APs to which an embodiment of the present disclosure is applicable. FIG. 13 illustrates an example of M-AP related operation between a sharing AP, candidate AP1, candidate AP2, and candidate AP3. Candidate AP1, candidate AP2, and candidate AP3 are coordinated APs.

[0244] Referring to FIG. 13, the sharing AP can transmit an ICF for polling after a backoff period. For example, if information regarding long-term traffic is shared among APs, the sharing AP can identify the AP expected to have the most traffic at the time of transmitting the ICF based on this, and can identify that the AP expected to have the most traffic at the time of transmitting the ICF is most likely to accept the polling. Assuming the sharing AP identifies that candidate AP1 is most likely to accept the polling, the sharing AP can allocate a RU (e.g., RU1) for candidate AP1 via the ICF, and allocate other coordinated APs (candidate AP2, candidate AP3) with different RUs (e.g., RU2). The sharing AP can allocate RU1 for candidate AP1 via the ICF, and allow candidate AP2 and candidate AP3 to perform random access through competition at RU2.

[0245] If candidate AP1 has no intention of sharing a TXOP from a sharing AP (or participating in an M-AP operation), candidate AP1 may send a rejection response from RU1 allocated after a specific IFS (e.g., SIFS) from the ICF. Here, since RU2 is not allocated to candidate AP1, RU2 may be sent empty. Since candidate AP1 has RU1 allocated exclusively and does not participate in contention for a UORA, it may send a rejection response if it has no intention of sharing a TXOP.

[0246] If candidate AP2 and candidate AP3 intend to share a TXOP from the sharing AP (or intend to participate in the M-AP operation) and candidate AP2 wins the competition, candidate AP2 can send an acknowledgment response to RU2 after a specific IFS (e.g., SIFS) from the ICF and participate in the M-AP operation. Here, since RU1 is allocated to candidate AP1, RU1 can be transmitted empty. Candidate AP3 does not send a rejection response because it was not allocated a dedicated resource and did not win the competition for the UORA.

[0247] After a specific IFS (e.g., SIFS) following an acknowledgment response, the sharing AP and candidate AP2 can perform M-AP operations (e.g., Co-TDMA, Co-BF, Co-SR).

[0248] Although the description of one embodiment of the present disclosure above has focused on the use of an ICF for polling, the present disclosure is not limited thereto, and a non-polling control frame may also be used.

[0249] FIGS. 14 and 15 are drawings illustrating an example of AP UORA operation based on a non-polling control frame according to an embodiment of the present disclosure. In FIGS. 14 and 15, an AP transmitting a request / response for discovery, agreement establishment, or parameter negotiation is exemplified as an uncoordinated AP, but an embodiment of the present disclosure described below may also be applied to a coordinated AP.

[0250] Referring to FIG. 14, when multiple APs intend to establish M-AP discovery (MAPC discovery) or a MAPC agreement with an AP, each AP may compete for wireless medium (WM) possession and, after winning the competition, transmit a request for discovery or agreement establishment. For example, uncoordinated AP1 may transmit a request for M-AP discovery (MAPC discovery) or agreement establishment after a backoff period. After a certain number of IFS (e.g., SIFS) from the request, the target AP may transmit an acknowledgment (Ack). uncoordinated AP2 may transmit a request for M-AP discovery (MAPC discovery) or agreement establishment after a backoff period. After a certain number of IFS (e.g., SIFS) from the request, the target AP may transmit an acknowledgment.

[0251] UORA may also be applied to the transmission of the aforementioned M-AP discovery (MAPC discovery), agreement establishment, or parameter negotiation request / response. An AP (target AP) can find the AP that intends to perform M-AP discovery (MAPC discovery), agreement establishment, or parameter negotiation request / response through UORA. In this case, even for uncoordinated APs, multiple RA-RUs corresponding to a single AID may be assigned. Furthermore, it is not necessary to specify one of the APs using an AID for at least one RU, and all RUs may be used as RA-RUs. This may be because, since the target AP has completed the transmission of all traffic within the TXOP through intra-BSS frame exchange, etc., even if all RAs specified in the control frame are used as RA-RUs, for example, if there is no response to the control frame, the TXOP can simply be terminated after the transmission of all traffic is completed.

[0252] Specifically, referring to FIG. 15, the target AP is capable of intra-BSS frame exchange after a backoff period. In the middle or later part of the TXOP, the target AP may transmit a control frame. In the control frame, RU1 may be assigned as an RA-RU for all uncoordinated APs, and RU2 may also be assigned as an RA-RU for uncoordinated APs. An AID may be set to a specific value (e.g., 2048) so that the corresponding RU is indicated as an RA-RU for uncoordinated APs.

[0253] An uncoordinated AP1 that intends to transmit an M-AP discovery (MAPC discovery) or agreement establishment request may transmit the M-AP discovery (MAPC discovery) or agreement establishment request to RU1 after a certain number of IFS (e.g., SIFS) from the control frame, based on UORA operations. An uncoordinated AP2 that intends to transmit an M-AP discovery (MAPC discovery) or agreement establishment request may transmit the M-AP discovery (MAPC discovery) or agreement establishment request to RU2 after a certain number of IFS (e.g., SIFS) from the control frame, based on UORA operations. An uncoordinated AP3 that does not intend to transmit an M-AP discovery (MAPC discovery) or agreement establishment request, or that did not win the contention, may not perform the transmission. Subsequently, the target AP may transmit a block ACK. Compared to the case of Fig. 14, in the operation exemplified in Fig. 14, each AP transmitting an M-AP discovery (MAPC discovery) or agreement establishment request must go through backoff, but in the operation based on UORA as in Fig. 15, backoff for transmitting an M-AP discovery or agreement establishment request is unnecessary, so overhead can be reduced.

[0254] FIG. 16 illustrates an example of the operation of a first AP according to an embodiment of the present disclosure. The flowchart of FIG. 16 illustrates an exemplary method that can be implemented according to the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart. For example, although illustrated as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.

[0255] Referring to FIG. 16, in operation 1610 according to one embodiment of the present disclosure, the first AP may receive a control frame from the second AP. The control frame may include information regarding that a portion of the TXOP of the second AP will be shared.

[0256] In operation 1620 according to one embodiment of the present disclosure, the first AP may perform an operation related to AP OFDMA (orthogonal frequency division multiple access)-based random access (an operation related to AP UORA) for transmitting an accept response related to sharing a portion of the TXOP of the second AP.

[0257] According to one embodiment of the present disclosure, a control frame may include one or more AID12 subfields set to a value associated with a first AP among predefined values ​​for AP UORA-related operations.

[0258] According to one embodiment of the present disclosure, AP UORA-related operations may be based on one or more RUs corresponding to one or more AID12 subfields set to values ​​associated with a first AP among a plurality of RUs indicated in a control frame.

[0259] More specific details regarding the operation of the first AP according to one embodiment of the present disclosure described above may be referenced to the description of various embodiments of the present disclosure described above.

[0260] FIG. 17 illustrates an example of the operation of a second AP according to an embodiment of the present disclosure. The flowchart of FIG. 17 illustrates an exemplary method that can be implemented according to the principles of the present disclosure, and various modifications may be made to the method illustrated in the flowchart. For example, although illustrated as a series of steps, the various steps in each figure may overlap, occur in parallel, occur in a different order, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.

[0261] Referring to FIG. 17, in operation 1710 according to one embodiment of the present disclosure, the second AP may transmit a control frame. The control frame may include information regarding that a portion of the second AP's TXOP (transmission opportunity) will be used for an M-AP coordinated transmission scheme. It may also include RA-RU information for receiving M-AP discovery (MAPC discovery) or MAPC agreement establishment or parameter negotiation request / response.

[0262] In operation 1720 according to one embodiment of the present disclosure, the second AP may receive an accept response from the first AP. The accept response may relate to the first AP using an M-AP coordinated transmission scheme in part of the second AP's TXOP. It may also relate to transmitting an M-AP discovery (MAPC discovery) or a MAPC agreement establishment or parameter negotiation request / response.

[0263] According to one embodiment of the present disclosure, a control frame may include one or more AID12 subfields set to a value associated with a first AP among values ​​predefined for AP OFDMA (orthogonal frequency division multiple access)-based random access (AP UORA).

[0264] According to one embodiment of the present disclosure, an acknowledgment response may be received at a specific RU among one or more RUs corresponding to one or more AID12 subfields set to a value associated with a first AP among a plurality of RUs (resource units) indicated in the control frame.

[0265] More specific details regarding the operation of the second AP according to one embodiment of the present disclosure described above may be referenced to the descriptions of various embodiments of the present disclosure described above.

[0266] Methods according to the claims or embodiments described in the specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0267] When implemented in software, a computer-readable storage medium may be provided for storing one or more programs (software modules). One or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. One or more programs include instructions that cause the electronic device to execute methods according to the claims or embodiments described in the specification of this disclosure.

[0268] Such programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, ROM (Read Only Memory), Electrically Erasable Programmable Read Only Memory (EEPROM), magnetic disc storage devices, Compact Disc-ROM (CD-ROM), Digital Versatile Discs (DVDs), or other forms of optical storage devices, magnetic cassettes. Alternatively, they may be stored in memory composed of some or all of these. Additionally, each constituent memory may include multiple units.

[0269] Additionally, the program may be stored on an attachable storage device accessible via a communication network such as the Internet, Intranet, Local Area Network (LAN), Wide LAN (WLAN), or Storage Area Network (SAN), or a combination thereof. Such a storage device may be connected to a device performing an embodiment of the present disclosure through an external port. Additionally, a separate storage device on a communication network may be connected to a device performing an embodiment of the present disclosure.

[0270] In the specific embodiments of the present disclosure described above, the components included in one embodiment are expressed in a singular or plural form according to the specific embodiment presented. However, the singular or plural expression is selected to suit the situation presented for convenience of explanation, and the present disclosure is not limited to singular or plural components; even if a component is expressed in the plural form, it may be composed in the singular form, or even if a component is expressed in the singular form, it may be composed in the plural form.

[0271] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples provided to facilitate the explanation of the technical content of the present disclosure and to aid in understanding the present disclosure, and are not intended to limit the scope of the present disclosure. That is, it is obvious to those skilled in the art that other variations based on the technical concept of the present disclosure are possible. Furthermore, each of the above embodiments may be combined and operated together as needed.

[0272] Meanwhile, the order of description in the drawings illustrating the method of the present disclosure does not necessarily correspond to the order of execution, and the order of execution may be changed or executed in parallel.

[0273] Alternatively, drawings describing the method of the present disclosure may omit some components and include only some components to the extent that the essence of the present disclosure is not impaired.

[0274] Additionally, the method of the present disclosure may be implemented by combining some or all of the contents included in each embodiment to the extent that it does not impair the essence of the present disclosure.

[0275] Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes only and is not limited to the embodiments disclosed. Those skilled in the art will understand that other specific forms can be easily modified without altering the technical spirit or essential features of the present disclosure. The scope of the present disclosure is defined by the claims set forth below rather than by the foregoing detailed description, and all modifications or variations derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included within the scope of the present disclosure.

Claims

1. A method performed by a first AP (access point) in a wireless LAN (local access network), A step of receiving a control frame from a second AP, wherein the control frame includes information relating that a portion of the TXOP (transmission opportunity) of the second AP will be used in an M-AP (multi-AP) coordinated transmission scheme; and The method includes the step of performing an operation related to AP OFDMA (orthogonal frequency division multiple access)-based random access for transmitting an accept response related to using the M-AP cooperative transmission scheme in part of the TXOP of the second AP, and The above control frame includes one or more AID (association identifier)12 subfields set to values ​​associated with the first AP among the values ​​predefined for the AP OFDMA-based random access, and A method in which the operation related to the above AP OFDMA-based random access is based on one or more RUs corresponding to one or more AID12 subfields among a plurality of RUs (resource units) indicated in the control frame.

2. In Paragraph 1, Each of the above-mentioned predefined values ​​is defined within 2008 to 2044 and 2047 to 4094, and The above predefined values ​​are: The first value indicating that the RU corresponding to the AID12 subfield set as the first value is an RA-RU (random access-RU) for an uncoordinated AP; The second value indicating that the RU corresponding to the AID12 subfield set as the second value is an RA-RU for a non-cooperative AP having LL (low latency) traffic; The third value indicating that the RU corresponding to the AID12 subfield set as the third value is an RA-RU for a coordinated AP; or A method comprising one or more of the fourth values ​​indicating that the RU corresponding to the AID12 subfield set to the fourth value is an RA-RU for a cooperative AP having traffic that exceeds a predefined priority or has a priority greater than or equal to the predefined priority.

3. In Paragraph 1, If the first AP decides to use the M-AP cooperative transmission scheme in part of the second AP's TXOP, the acknowledgment response is transmitted from the control frame after a specific IFS (inter frame space), and A method in which, when the first AP decides not to use the M-AP cooperative transmission scheme in part of the second AP's TXOP, a response for the control frame is not transmitted from the control frame after the specific IFS (inter frame space).

4. In Paragraph 1, If the above control frame is an ICF (initial control frame) for polling: The number of RA-RUs included in the plurality of RUs is less than the number of the plurality of RUs, and one or more RUs are included in the RA-RU, A method in which the number of RA-RUs corresponding to one value for a non-cooperative AP among the values ​​of the AID12 subfields included in the control frame is at most one.

5. In Paragraph 1, When the first AP is a cooperative AP and a parameter set element for the AP OFDMA-based random access is exchanged, an OBO (OFDMA random access backoff) counter related to the operation related to the AP OFDMA-based random access is determined within a specific OCW range identified among a plurality of OCW (OFDMA contention window) ranges included in the parameter set element, and If the above first AP is a cooperative AP and the above parameter set elements are not exchanged, a predefined default value is determined as the above OBO counter, and If the above first AP is a non-cooperative AP, the above predefined default value is determined as the above OBO counter, and The step of performing the operation related to the above AP OFDMA-based random access is: A step of decreasing the OBO counter based on one or more of the above RUs; When the above OBO counter is decreased to 0, a step of randomly selecting a specific RU among the one or more RUs; and A method comprising the step of transmitting the acknowledgment response at the specific RU.

6. In the first AP (access point) of a wireless LAN (local access network), Transmitter / receiver; and It includes a processor connected to the above-mentioned transceiver, and the processor is: Receive a control frame from the second AP, said control frame containing information that a portion of the second AP's TXOP (transmission opportunity) will be used in an M-AP (multi-AP) coordinated transmission scheme; and The AP is configured to perform operations related to an orthogonal frequency division multiple access (OFDMA)-based random access for transmitting an accept response related to using the M-AP cooperative transmission scheme in part of the TXOP of the second AP, and The above control frame includes one or more AID (association identifier)12 subfields set to values ​​associated with the first AP among the values ​​predefined for the AP OFDMA-based random access, and The operation related to the above AP OFDMA-based random access is based on one or more RUs corresponding to one or more AID12 subfields among a plurality of RUs (resource units) indicated in the control frame, a first AP.

7. In Paragraph 6, Each of the above-mentioned predefined values ​​is defined within 2008 to 2044 and 2047 to 4094, and The above predefined values ​​are: The first value indicating that the RU corresponding to the AID12 subfield set as the first value is an RA-RU (random access-RU) for an uncoordinated AP; The second value indicating that the RU corresponding to the AID12 subfield set as the second value is an RA-RU for a non-cooperative AP having LL (low latency) traffic; The third value indicating that the RU corresponding to the AID12 subfield set as the third value is an RA-RU for a coordinated AP; or A first AP comprising one or more of the fourth values ​​indicating that the RU corresponding to the AID12 subfield set to the fourth value is an RA-RU for a cooperative AP having traffic that exceeds a predefined priority or has a priority greater than or equal to the predefined priority.

8. In Paragraph 6, If the first AP decides to use the M-AP cooperative transmission scheme in part of the second AP's TXOP, the acknowledgment response is transmitted from the control frame after a specific IFS (inter frame space), and A first AP in which, if the first AP decides not to use the M-AP cooperative transmission scheme in part of the TXOP of the second AP, a response for the control frame is not transmitted from the control frame after the specific IFS (inter frame space).

9. In Paragraph 6, If the above control frame is an ICF (initial control frame) for polling: The number of RA-RUs included in the plurality of RUs is less than the number of the plurality of RUs, and one or more RUs are included in the RA-RU, A first AP in which the number of RA-RUs corresponding to one value for a non-cooperative AP among the values ​​of the AID12 subfields included in the control frame is at most one.

10. In Paragraph 6, When the first AP is a cooperative AP and a parameter set element for the AP OFDMA-based random access is exchanged, an OBO (OFDMA random access backoff) counter related to the operation related to the AP OFDMA-based random access is determined within a specific OCW range identified among a plurality of OCW (OFDMA contention window) ranges included in the parameter set element, and If the above first AP is a cooperative AP and the above parameter set elements are not exchanged, a predefined default value is determined as the above OBO counter, and If the above first AP is a non-cooperative AP, the above predefined default value is determined as the above OBO counter, and In performing operations related to the above AP OFDMA-based random access, the processor: Decrease the OBO counter based on one or more of the above RUs; When the above OBO counter is decreased to 0, a specific RU is randomly selected from the one or more RUs; and A first AP configured to transmit the acknowledgment response at the specific RU mentioned above.

11. A method performed by a second AP (access point) in a wireless LAN (local access network), A step of transmitting a control frame, wherein the control frame includes information relating that a portion of the TXOP (transmission opportunity) of the second AP will be used in an M-AP (multi-AP) coordinated transmission scheme; and The method comprises the step of receiving an accept response from a first AP regarding the first AP using the M-AP cooperative transmission scheme in part of the TXOP of the second AP, wherein the control frame includes one or more AID (association identifier)12 subfields set to values ​​associated with the first AP among predefined values ​​for AP OFDMA (orthogonal frequency division multiple access)-based random access, and A method in which the above acknowledgment response is received at a specific RU among one or more RUs corresponding to one or more AID12 subfields among a plurality of RUs (resource units) indicated in the control frame.

12. In Paragraph 11, Each of the above-mentioned predefined values ​​is defined within 2008 to 2044 and 2047 to 4094, and The above predefined values ​​are: The first value indicating that the RU corresponding to the AID12 subfield set as the first value is an RA-RU (random access-RU) for an uncoordinated AP; The second value indicating that the RU corresponding to the AID12 subfield set as the second value is an RA-RU for a non-cooperative AP having LL (low latency) traffic; The third value indicating that the RU corresponding to the AID12 subfield set as the third value is an RA-RU for a coordinated AP; or A method comprising one or more of the fourth values ​​indicating that the RU corresponding to the AID12 subfield set to the fourth value is an RA-RU for a cooperative AP having traffic that exceeds a predefined priority or has a priority greater than or equal to the predefined priority.

13. In a second AP (access point) of a wireless LAN (local access network), Transmitter / receiver; and It includes a processor connected to the above-mentioned transceiver, and the processor is: Transmitting a control frame, said control frame containing information that a portion of the TXOP (transmission opportunity) of said second AP will be used in an M-AP (multi-AP) coordinated transmission scheme; and From the first AP, the first AP is configured to receive an accept response related to using the M-AP cooperative transmission scheme in part of the second AP's TXOP, and The above control frame includes one or more AID (association identifier)12 subfields set to values ​​associated with the first AP among predefined values ​​for AP OFDMA (orthogonal frequency division multiple access)-based random access, and The above acknowledgment response is a second AP received at a specific RU among one or more RUs corresponding to one or more AID12 subfields among the plurality of RUs (resource units) indicated in the control frame.

14. In Paragraph 13, Each of the above-mentioned predefined values ​​is defined within 2008 to 2044 and 2047 to 4094, and The above predefined values ​​are: The first value indicating that the RU corresponding to the AID12 subfield set as the first value is an RA-RU (random access-RU) for an uncoordinated AP; The second value indicating that the RU corresponding to the AID12 subfield set as the second value is an RA-RU for a non-cooperative AP having LL (low latency) traffic; The third value indicating that the RU corresponding to the AID12 subfield set as the third value is an RA-RU for a coordinated AP; or A second AP comprising one or more of the fourth values ​​indicating that the RU corresponding to the AID12 subfield set to the fourth value is an RA-RU for a cooperative AP having traffic that exceeds a predefined priority or has a priority greater than or equal to the predefined priority.

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