Method and apparatus for channel switching in wireless LAN system

Abstract

Various embodiments of the present disclosure relate to a method and an apparatus for channel switching in a wireless LAN system. A method performed by a first station (STA), according to an embodiment of the present disclosure, may comprise the steps of: identifying that an operation related to channel switching is to be performed, on the basis of identifying that a first channel for a direct-link with a second STA is busy; and performing the operation related to the channel switching.

Description

Method and device for channel switching in a wireless LAN system

[0001] The present disclosure relates generally to a wireless LAN system, and more particularly to a method and device for channel switching in a wireless LAN system.

[0002] A wireless local area network (WLAN), also known as Wireless Fidelity (Wi-Fi), is a network that allows users to access the Internet via mobile devices or laptops within a certain distance from an access point (AP). WLAN technology continues to evolve with the rise of the Internet and the expansion of the smartphone market, and WLAN is used to provide high-speed data services to entire cities, including 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 standards. IEEE 802.11a and b, published in 1997 and 1999 respectively, are standards that utilize the unlicensed bands at 2.4 GHz and 5 GHz, with IEEE 802.11b providing a transmission rate of 11 Mbps and IEEE 802.11a providing a transmission rate of 54 Mbps. IEEE 802.11g applies orthogonal frequency-division multiplexing (OFDM) at 2.4 GHz to provide a transmission rate of 54 Mbps. IEEE 802.11n uses multiple input multiple output OFDM (MIMO-OFDM) to provide a transmission rate of 300 Mbps using four spatial streams. IEEE 802.11n supports channel bandwidths up to 40 MHz, in which case it provides a transmission rate of 600 Mbps.

[0004] Afterwards, the IEEE 802.11ac standard was introduced, which supports up to 160 MHz bandwidth, 8 spatial streams, and a speed of up to 1 Gbit / s, and IEEE 802.11ax, which provides multi-user MIMO (MU-MIMO) in both uplink and downlink and supports spatial frequency reuse, dynamic fragmentation, etc. Afterwards, 802.11be is being studied, which supports up to 320 ultra-wide channels, multi-link operation, 4kQAM, etc., and aims to theoretically implement a speed of 46 Gbps.

[0005] Various embodiments of the present disclosure can provide a method and device for transmitting and receiving signals in a wireless LAN system.

[0006] Various embodiments of the present disclosure can provide a method and device for channel switching in a wireless LAN system.

[0007] The technical problems to be achieved in various embodiments of the present disclosure are not limited to those mentioned above, and other technical problems not mentioned can be considered by a person having ordinary skill in the art from various embodiments of the present disclosure described below.

[0008] According to one embodiment of the present disclosure, a method performed by a first STA (station) in a wireless local access network (LAN) system may be provided.

[0009] According to one embodiment of the present disclosure, the method may include a step of identifying to perform an operation related to channel switching based on identifying that a first channel for a direct-link with a second STA is busy.

[0010] According to one embodiment of the present disclosure, the method may include a step of performing an operation related to the channel switching.

[0011] According to one embodiment of the present disclosure, the step of performing an operation related to channel switching may include the step of identifying a second channel corresponding to the first channel.

[0012] According to one embodiment of the present disclosure, the step of performing an operation related to the channel switching may include the step of obtaining a transmission opportunity (TXOP) for a non-primary channel (NPCH) including the second channel based on a channel access procedure in the second channel.

[0013] According to one embodiment of the present disclosure, the step of performing an operation related to the channel switching may include the step of communicating with the second STA through the direct connection on the NPCH based on the TXOP.

[0014] According to one embodiment of the present disclosure, the first channel is identified as busy when a transmission related to an overlapping basic service set (OBSS) is identified on the first channel, and an operation related to channel switching is identified to be performed based on the first STA being identified as having non-primary channel access (NPCA) disabled in an access point (AP) to which the first STA is associated, and an operation related to channel switching is identified to be performed based on the first STA being identified as having non-primary channel access (NPCA) enabled in an access point (AP) to which the first STA is associated, and an identifier of the OBSS is not included in an identifier of one or more basic service sets (BSS) received from the AP.

[0015] According to one embodiment of the present disclosure, upon identification of a transmission related to an intra-BSS on the first channel, the first channel is identified as busy, and a transmitting address (TA) of an initial control frame (ICF) received by the first STA on the first channel indicates a medium access control (MAC) address of an AP associated with the first STA; a receiving address (RA) of the ICF does not indicate a broadcast address, and an RA of the ICF does not indicate a MAC address of the first STA and a MAC address of the second STA; or an RA of the ICF indicates the broadcast address, and an association identifier (AID) subfield of a User Info field does not indicate the first STA and the second STA; and upon identification of the first channel as busy after reception of the ICF, an operation related to channel switching may be performed.

[0016] According to one embodiment of the present disclosure, the first channel is identified as busy when a transmission related to an intra-BSS is identified on the first channel, and the first STA is identified to perform an operation related to channel switching based on receiving an initial control response (ICR) on the first channel after receiving the ICF and the TA of the ICF received on the first channel does not indicate a MAC address of an AP associated with the first STA, a MAC address of the first STA, and a MAC address of the second STA.

[0017] According to one embodiment of the present disclosure, it can be identified that the first STA will perform an operation related to the channel switching based on the fact that the RA of the ICR received on the first channel does not indicate the MAC address of the AP associated with the first STA, the MAC address of the first STA, and the MAC address of the second STA.

[0018] According to one embodiment of the present disclosure, when a transmission related to an intra-BSS is identified on the first channel, the first channel is identified as busy, and the first STA is identified to perform an operation related to channel switching based on the fact that an STA_ID in a user specific field in a SIG (signal) of a high efficiency (HE) physical layer protocol data unit (PPDU), an extremely high throughput (EHT) PPDU or an ultra high reliability (UHR) PPDU received on the first channel does not indicate the first STA and the second STA, and the first STA is identified to perform an operation related to channel switching based on the fact that a group ID and a number of space-time streams (NSTS) of a very high throughput (VHT) multi user (MU) PPDU received on the first channel do not indicate the first STA and the second STA, and the first STA is identified to perform an operation related to channel switching based on the fact that a VHT single user (SU) received on the first channel does not indicate the first STA and the second STA. It can be identified that the operation related to the channel switching is to be performed based on the PAID (partial AID) of the PPDU not indicating the first STA and the second STA, and it can be identified that the operation related to the channel switching is to be performed based on the RA of the HT (high throughput) PPDU, non-HT PPDU or control frame received by the first STA on the first channel not indicating the first STA and the second STA.

[0019] According to one embodiment of the present disclosure, the direct connection corresponds to a tunneled direct-link setup (TDLS) between the first STA and the second STA, the first channel is a base channel associated with the TDLS, the channel access procedure is for NPCA-based channel switching from the base channel, and one or more elements associated with NPCA-based channel switching from the base channel are exchanged between the first STA and the second STA in the setup procedure associated with the TDLS, wherein the one or more elements may include one or more of an element for a capability associated with NPCA-based channel switching, an element for the second channel for the base channel, an element for a channel bandwidth of the NPCH, an element for a center frequency of the NPCH, an element for a channel switch time associated with NPCA-based channel switching from the base channel, or an element associated with a user position array field.

[0020] According to one embodiment of the present disclosure, the element for the capability related to the NPCA-based channel switching corresponds to 1 bit within the UHR capability, the element for the second channel for the base channel corresponds to a target channel field of 1 octet, the element for the channel bandwidth of the NPCH corresponds to a control subfield of 1 octet of bandwidth indication information of a bandwidth indication element, and the element for the center frequency of the NPCH may correspond to at least one of a channel center frequency segment (CCFS)0 subfield or a CCFS1 subfield of the bandwidth indication information.

[0021] According to one embodiment of the present disclosure, the direct connection corresponds to a TDLS between the first STA and the second STA, the first channel is an off channel associated with the TDLS, the channel access procedure is for NPCA-based channel switching from the off channel, and one or more elements associated with NPCA-based channel switching from the base channel are exchanged between the first STA and the second STA in the channel switching procedure associated with the TDLS, wherein the one or more elements may include one or more of the second channel for the off channel, a channel bandwidth of the NPCH, and a center frequency of the NPCH.

[0022] According to one embodiment of the present disclosure, the element for the second channel for the off-channel corresponds to a target channel field of 1 octet, the element for the channel bandwidth of the NPCH corresponds to a control subfield of 1 octet of bandwidth indication information of a bandwidth indication element, and the element for the center frequency of the NPCH may correspond to at least one of a CCFS0 subfield or a CCFS1 subfield of the bandwidth indication information.

[0023] According to one embodiment of the present disclosure, a first STA (station) of a wireless local access network (LAN) system may be provided.

[0024] According to one embodiment of the present disclosure, the first STA may include a transceiver; and a processor connected to the transceiver.

[0025] According to one embodiment of the present disclosure, the processor may be configured to identify to perform an operation related to channel switching based on identifying that a first channel for a direct-link with a second STA is busy.

[0026] According to one embodiment of the present disclosure, the processor may be configured to perform operations related to the channel switching.

[0027] According to one embodiment of the present disclosure, in performing the operation related to the channel switching, the processor may be configured to identify a second channel corresponding to the first channel.

[0028] According to one embodiment of the present disclosure, in performing the operation related to the channel switching, the processor may be configured to obtain a transmission opportunity (TXOP) for a non-primary channel (NPCH) including the second channel based on a channel access procedure in the second channel.

[0029] According to one embodiment of the present disclosure, in performing the operation related to the channel switching, the processor may be configured to communicate with the second STA through the direct connection in the NPCH based on the TXOP.

[0030] According to one embodiment of the present disclosure, the first channel is identified as busy when a transmission related to an overlapping basic service set (OBSS) is identified on the first channel, and an operation related to channel switching is identified to be performed based on the first STA being identified as having non-primary channel access (NPCA) disabled in an access point (AP) to which the first STA is associated, and an operation related to channel switching is identified to be performed based on the first STA being identified as having non-primary channel access (NPCA) enabled in an access point (AP) to which the first STA is associated, and an identifier of the OBSS is not included in an identifier of one or more basic service sets (BSS) received from the AP.

[0031] According to one embodiment of the present disclosure, when a transmission related to an intra-BSS is identified on the first channel, the first channel is identified as busy, and a transmitting address (TA) of an initial control frame (ICF) received by the first STA on the first channel indicates a medium access control (MAC) address of an AP associated with the first STA; a receiving address (RA) of the ICF does not indicate a broadcast address, and an RA of the ICF does not indicate a MAC address of the first STA and a MAC address of the second STA; or an RA of the ICF indicates the broadcast address, and an association identifier (AID) subfield of a User Info field does not indicate the first STA and the second STA; and an operation related to the channel switching can be identified based on receiving an initial control response (ICR) on the first channel after receiving the ICF.

[0032] According to one embodiment of the present disclosure, the first channel is identified as busy when a transmission related to an intra-BSS is identified on the first channel, and the first STA is identified to perform an operation related to channel switching based on receiving an initial control response (ICR) on the first channel after receiving the ICF and the TA of the ICF received on the first channel does not indicate a MAC address of an AP associated with the first STA, a MAC address of the first STA, and a MAC address of the second STA.

[0033] According to one embodiment of the present disclosure, it can be identified that the first STA will perform an operation related to the channel switching based on the fact that the RA of the ICR received on the first channel does not indicate the MAC address of the AP associated with the first STA, the MAC address of the first STA, and the MAC address of the second STA.

[0034] According to one embodiment of the present disclosure, when a transmission related to an intra-BSS is identified on the first channel, the first channel is identified as busy, and the first STA is identified to perform an operation related to channel switching based on the fact that an STA_ID in a user specific field in a SIG (signal) of a high efficiency (HE) physical layer protocol data unit (PPDU), an extremely high throughput (EHT) PPDU or an ultra high reliability (UHR) PPDU received on the first channel does not indicate the first STA and the second STA, and the first STA is identified to perform an operation related to channel switching based on the fact that a group ID and a number of space-time streams (NSTS) of a very high throughput (VHT) multi user (MU) PPDU received on the first channel do not indicate the first STA and the second STA, and the first STA is identified to perform an operation related to channel switching based on the fact that a VHT single user (SU) received on the first channel does not indicate the first STA and the second STA. It can be identified that the operation related to the channel switching is to be performed based on the PAID (partial AID) of the PPDU not indicating the first STA and the second STA, and it can be identified that the operation related to the channel switching is to be performed based on the RA of the HT (high throughput) PPDU, non-HT PPDU or control frame received by the first STA on the first channel not indicating the first STA and the second STA.

[0035] According to one embodiment of the present disclosure, the direct connection corresponds to a tunneled direct-link setup (TDLS) between the first STA and the second STA, the first channel is a base channel associated with the TDLS, the channel access procedure is for NPCA-based channel switching from the base channel, and one or more elements associated with NPCA-based channel switching from the base channel are exchanged between the first STA and the second STA in the setup procedure associated with the TDLS, wherein the one or more elements may include one or more of an element for a capability associated with NPCA-based channel switching, an element for the second channel for the base channel, an element for a channel bandwidth of the NPCH, an element for a center frequency of the NPCH, an element for a channel switch time associated with NPCA-based channel switching from the base channel, or an element associated with a user position array field.

[0036] According to one embodiment of the present disclosure, the element for the capability related to the NPCA-based channel switching corresponds to 1 bit within the UHR capability, the element for the second channel for the base channel corresponds to a target channel field of 1 octet, the element for the channel bandwidth of the NPCH corresponds to a control subfield of 1 octet of bandwidth indication information of a bandwidth indication element, and the element for the center frequency of the NPCH may correspond to at least one of a channel center frequency segment (CCFS)0 subfield or a CCFS1 subfield of the bandwidth indication information.

[0037] According to one embodiment of the present disclosure, the direct connection corresponds to a TDLS between the first STA and the second STA, the first channel is an off channel associated with the TDLS, the channel access procedure is for NPCA-based channel switching from the off channel, and one or more elements associated with NPCA-based channel switching from the base channel are exchanged between the first STA and the second STA in the channel switching procedure associated with the TDLS, wherein the one or more elements may include one or more of the second channel for the off channel, a channel bandwidth of the NPCH, and a center frequency of the NPCH.

[0038] According to one embodiment of the present disclosure, the element for the second channel for the off-channel corresponds to a target channel field of 1 octet, the element for the channel bandwidth of the NPCH corresponds to a control subfield of 1 octet of bandwidth indication information of a bandwidth indication element, and the element for the center frequency of the NPCH may correspond to at least one of a CCFS0 subfield or a CCFS1 subfield of the bandwidth indication information.

[0039] The various embodiments of the present disclosure described above are only 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 a person having ordinary skill in the art based on the detailed description to be described below.

[0040] Various embodiments of the present disclosure can provide a method and device for transmitting and receiving signals in a wireless LAN system.

[0041] Various embodiments of the present disclosure can provide a method and device for channel switching in a wireless LAN system.

[0042] The effects that can be obtained from various embodiments of the present disclosure are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by a person having ordinary skill in the art based on the detailed description below.

[0043] The accompanying drawings are intended to aid in understanding various embodiments of the present disclosure, and provide various embodiments of the present disclosure together with detailed descriptions. 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 each other to form new embodiments. Reference numerals in each drawing represent structural elements.

[0044] FIG. 1 is a diagram illustrating an example of a wireless communication network to which various embodiments of the present disclosure can be applied.

[0045] FIG. 2 is a diagram illustrating an example of the structure of an electronic device performing WLAN connection to which various embodiments of the present disclosure are applicable.

[0046] 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.

[0047] FIG. 4 is a diagram 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 a CTS for solving the problem of the hidden node and the exposed node.

[0048] FIG. 5 is a diagram illustrating an example of a frame structure used in an IEEE 802.11 system to which various embodiments of the present disclosure are applicable.

[0049] FIG. 6 is a diagram illustrating an example of NAV settings to which various embodiments of the present disclosure can be applied.

[0050] FIG. 7 is a diagram illustrating an example of a TXOP to which various embodiments of the present disclosure can be applied.

[0051] FIG. 8 is a diagram showing an example of a TDLS to which various embodiments of the present disclosure can be applied.

[0052] FIG. 9 is a diagram illustrating an example of TDLS channel switching to which various embodiments of the present disclosure are applicable.

[0053] FIG. 10 is a diagram for explaining a PS (power save) mode to which various embodiments of the present disclosure are applicable.

[0054] FIG. 11 is a diagram for explaining a PS (power save) mode to which various embodiments of the present disclosure are applicable.

[0055] FIG. 12 is a diagram showing an example of channel connection to which various embodiments of the present disclosure can be applied.

[0056] FIG. 13 is a diagram illustrating an example of an NPCA operation to which various embodiments of the present disclosure can be applied.

[0057] FIG. 14 is a diagram illustrating an example of an NPCA operation to which various embodiments of the present disclosure can be applied.

[0058] FIG. 15 is a diagram illustrating an example of an NPCA operation to which various embodiments of the present disclosure are applicable.

[0059] FIG. 16 is a diagram illustrating an example of NPCA-based channel switching according to one embodiment of the present disclosure.

[0060] FIG. 17a is a diagram illustrating an example of a format for transmitting information required to activate NPCA-based channel switching according to one embodiment of the present disclosure.

[0061] FIG. 17b is a diagram illustrating an example of a format for transmitting information required to activate NPCA-based channel switching according to one embodiment of the present disclosure.

[0062] FIG. 17c is a diagram illustrating an example of a format for transmitting information required to activate NPCA-based channel switching according to one embodiment of the present disclosure.

[0063] FIG. 18 is a diagram illustrating an example of an NPCA-based channel switching operation from a base channel according to one embodiment of the present disclosure.

[0064] FIG. 19 is a diagram illustrating an example of an NPCA-based channel switching operation from a base channel according to one embodiment of the present disclosure.

[0065] FIG. 20 is a diagram illustrating an example of NPCA-based channel switching according to one embodiment of the present disclosure.

[0066] FIG. 21 is a diagram illustrating an example of NPCA-based channel switching according to one embodiment of the present disclosure.

[0067] FIG. 22 is a diagram illustrating an example of NPCA-based channel switching according to one embodiment of the present disclosure.

[0068] FIG. 23 illustrates an example of the operation of an STA according to one embodiment of the present disclosure.

[0069] FIG. 24 illustrates an example of the operation of an STA according to one embodiment of the present disclosure.

[0070] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the attached drawings.

[0071] In describing the embodiments, descriptions of technical details that are well known in the technical field to which the present disclosure pertains and are not directly related to the present disclosure will be omitted. This is to ensure that the gist of the present disclosure is conveyed more clearly without obscuring it by omitting unnecessary explanations.

[0072] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0073] The advantages and features of the present disclosure, and methods for achieving them, will become clearer with reference to the embodiments described below in detail together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below and may be implemented in various different forms. The embodiments of the present disclosure are provided only to ensure that the present disclosure is 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. Like reference numerals refer to like elements throughout the specification.

[0074] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s).

[0075] Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, so that the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also be able to provide steps for performing the functions described in the flowchart block(s).

[0076] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementation examples, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0077] Here, the term '~ unit' used in this embodiment means software or hardware components such as FPGA (field programmable gate array) or ASIC (application specific integrated circuit), and the '~ unit' performs certain roles. However, the '~ unit' is not limited to software or hardware. The '~ unit' may be configured to be on an addressable storage medium and may be configured to play one or more processors. Accordingly, according to some embodiments, the '~ unit' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, 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 '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. Additionally, the components and '~parts' may be implemented to activate one or more CPUs within the device or secure multimedia card. Furthermore, according to some embodiments, the '~parts' may include one or more processors.

[0078] The exemplary embodiments are described below solely for simplicity with respect to wireless LAN systems. It should be understood that the exemplary embodiments are equally applicable to other wireless networks (e.g., cellular networks, pico-networks, femto-networks, satellite networks), as well as systems that utilize signals of one or more wired standards or protocols (e.g., Ethernet and / or HomePlug, PLC standards). As used herein, the terms WLAN and Wi-Fi® may include communications governed by the IEEE 802.11 family of standards, BLUETOOTH®, HiperLAN (a set of wireless standards primarily used in Europe and comparable to the IEEE 802.11 standards), and other technologies with relatively short radio ranges. Accordingly, the terms WLAN and WiFi may be used interchangeably herein. Additionally, while described below with respect to an infrastructure WLAN system including one or more APs and a plurality of wireless stations (STAs), the 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.

[0079] Additionally, while the present disclosure describes the exchange of data frames between wireless devices, the exemplary embodiments may be applied to the exchange of any data unit, packet, and / or frame between wireless devices. Thus, 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. A wireless local area network, or WLAN network, below may be a network implementing at least one of the IEEE 802.11 family of wireless communication protocol standards, such as those defined by the IEEE 802.11-2016 standard or amendments thereto (including, but not limited to, 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be).

[0080] In the following description, numerous specific details are set forth, such as examples of specific components, circuits, and processes, to provide a thorough understanding of the present disclosure. The term "connected," as used herein, means directly connected or connected via one or more intervening components or circuits. The term "connected AP" refers to an access point with which a given wireless station is currently associated and / or connected (e.g., there is an established communications channel or link between the access point and the given wireless station). Furthermore, in the following description and for purposes of explanation, specific nomenclature is set forth to provide a thorough understanding of the exemplary embodiments. However, it will be apparent to one skilled in the art that such specific details may not be necessary to practice the exemplary embodiments. In other instances, well-known circuits and devices are shown in block diagram form to avoid obscuring the present disclosure.

[0081] The operating principles of the present disclosure are described in detail below with reference to the attached drawings. In the following description of the present disclosure, detailed descriptions of related known functions or configurations will be omitted if they are deemed to unnecessarily obscure the gist of the present disclosure. Furthermore, the terms described below are defined based on the functions of the present disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0082] FIG. 1 is a diagram illustrating an example of a wireless communication network to which various embodiments of the present disclosure can be applied.

[0083] The wireless communication network (100) may be an example of a wireless local area network (LAN), such as a Wi-Fi network. The wireless communication network (100) may include a plurality of wireless communication devices, such as an AP (102) and a plurality of STAs (stations, 104). Although only one AP (102) is illustrated, the wireless communication network (100) may also include a plurality of APs (102).

[0084] An STA is a logical entity that includes a MAC and a physical layer interface to a wireless medium, and includes an AP and a non-AP STA (Non-AP station). Among the STAs, a portable terminal operated by a user is a Non-AP STA, and when simply referred to as an STA, it also refers to a Non-AP STA. Hereinafter, an STA may refer to a non-AP STA. Each of the STAs (104) may be referred to as a terminal or a device. The term '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 a cellular telephone, a smart phone having wireless communication capabilities, a personal digital assistant (PDA) having wireless communication capabilities, a wireless modem, a portable computer having wireless communication capabilities, a photographic device such as a digital camera having wireless communication capabilities, a gaming device having wireless communication capabilities, a music storage and playback appliance having wireless communication capabilities, an Internet appliance capable of wireless Internet access and browsing, as well as portable units or terminals incorporating combinations of such functions. In addition, the terminal may include, but is not limited to, a machine-to-machine (M2M) terminal, a machine type communication (MTC) terminal / device. In the present specification, the terminal may also be referred to as an electronic device or simply a device.

[0085] An AP (102) is an entity that provides access to a distribution system (DS) via a wireless medium to its associated STAs. An AP may also be called a centralized controller, a base station (BS), a Node-B, a base transceiver system (BTS), or a site controller.

[0086] An exemplary coverage area (106) of an AP (102) that may represent a basic service area (BSA) of a wireless communication network (100) is illustrated. The AP (102) periodically broadcasts beacon frames (beacon frames may be used interchangeably with beacon) containing a basic service set identifier (BSSID) to enable any STAs (104) within the wireless range of the AP (102) to associate or re-associate with the AP (102) and establish or maintain a separate communication link (108) (or may be referred to as a Wi-Fi link) with the AP (102). The AP (102) may provide access to external networks for various STAs (104) within the WLAN via the separate communication links (108).

[0087] 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 the BSSID, which may be the MAC address of the AP (102).

[0088] BSS can be categorized into infrastructure BSS and independent BSS (IBSS). The BSS illustrated in Figure 1 is an IBSS, but an infrastructure BSS (not shown) can also be established. An infrastructure BSS includes one or more STAs and an AP. In principle, communication between non-AP STAs in an infrastructure BSS occurs via the AP. However, if a direct link is established between non-AP STAs, direct communication between non-AP STAs is also possible.

[0089] Multiple infrastructure BSSs can be interconnected via a DS. Multiple BSSs connected via a DS are called an extended service set (ESS). STAs within an ESS can communicate with each other, and within the same ESS, STAs can seamlessly move from one BSS to another while maintaining seamless communication.

[0090] A DS is a mechanism that connects multiple APs. It doesn't necessarily have to be a network, and there are no restrictions on its form as long as it can provide a certain distribution service. For example, a DS could be a wireless network, such as a mesh network, or a physical structure that connects APs.

[0091] Additionally, the AP (102) and the STA (104) may be referred to as AP-MLD (access point multi-link device) and STA-MDL, respectively. This may mean that the AP and the STA can support multi-link operation.

[0092] Below is an example of a hierarchical structure according to the 802.11 standard.

[0093] The 802.11 standard document is developing the 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, and receives packets from the upper layer, 802.1X Port Filtering, through the MAC_SAP interface, and configures 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, and the PLCP sublayer is responsible for configuring the IEEE 802.11 MAC frame configured in the MAC sublayer into a PLCP frame. The PLCP frame is then transmitted to the opposite terminal through the PMD sublayer.

[0094] Various management frames that manage Wi-Fi wireless access are not transmitted at the upper layer of 802.1X. These management frames are transmitted as requests and responses between the SMEs (station management entities) located within each terminal. The SME is a layer-independent entity that may exist in a separate management plane or may appear to be off to the side. For example, if an AP wants to form a BSS, the AP instructs the transmission of a beacon through the MLME_SAP interface, namely, the MLME-START.reques and MLME-START.confirm primitives. If an STA wants to associate with the AP, the STA instructs the transmission of an association Request / Response frame through the MLME-ASSOCIATE.request, MLME-ASSOCIATE.response, MLME-ASSOCIATE.confirm, and MLME-ASSOCIATE.indication primitives. Meanwhile, if SME wants to set operating parameter values ​​related to the physical layer, it can set various physical layer parameter values ​​through the PLCP_SAP interface.

[0095] FIG. 2 is a diagram illustrating an example of the structure of an electronic device performing WLAN connection to which various embodiments of the present disclosure are applicable.

[0096] Referring to FIG. 2, an 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.

[0097] 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 (for example, IEEE Std 802.11TM). For example, the communication module (220) can operate based on IEEE 802.11ac, 802.11ax, 802.11be, or 802.11bn among Wi-Fi communication methods, and in particular, IEEE 802.11be or 802.11bn has improved performance by supporting a wider bandwidth, higher data throughput, and shorter delay time compared to IEEE 802.11ax.

[0098] 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)). According to various embodiments, the communication module (220) may further include a memory.

[0099] According to various embodiments, the transceiver (224) may convert a baseband transmit signal into a wireless signal or may convert a received wireless signal into a baseband receive signal.

[0100] 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), for example, a modulator, a digital-analog converter (D / A converter), a frequency converter, an A / D converter, an amplifier, and / or a demodulator.

[0101] Although not shown, according to various embodiments, the electronic device (200) may include at least one antenna module that is electrically connected to the communication module of the AP (210) and supports a communication protocol and / or frequency band supported by the communication module of the AP (210).

[0102] The communication processor (222) may 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) may control the transceiver (224) to form a wireless connection with the AP (200) using a 2.4 GHz, 5 GHz, or 6 GHz band WLAN standard such as IEEE 802.11ac, 802.11ax, 802.11be, or 802.11bn. Alternatively, the communication processor (222) may control the transceiver (191) to form a wireless connection with the AP (210) using a 60 GHz band WLAN standard such as IEEE 802.11ad or 802.11ay. Additionally, a method of communicating between an electronic device (200) and an AP (210) using the WLAN standard may be referred to as a communication method based on the STA mode.

[0103] 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.

[0104] According to various embodiments, the AP (210) may support an operation of transmitting packets to an external network and / or an operation of the plurality of electronic devices receiving packets from an external network based on a connection between a plurality of electronic devices (e.g., the electronic device (200)) and an external network (e.g., the Internet, an external LAN, or a cellular network).

[0105] For example, the AP (210) may be a wireless router. The AP (210) may be a dedicated wireless router or a general-purpose device supporting mobile hotspot functionality, and there are no limitations on its implementation. For example, the AP (210) may include the same components as the electronic device (200), such as a processor and / or a communication module. Furthermore, the AP (210) may transmit and receive data to and from an external device, such as a server. For example, the AP (210) may transmit at least a portion of the data received from the server to the electronic device (200).

[0106] 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 the processor (230) or by a separate processor. The separate communication module may include a transceiver and a processor, and may also include memory. In addition, the electronic device (200) may include a separate antenna module or wired connection device for connection with an external network.

[0107] 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.

[0108] 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 complete security authentication procedures. The link setup process can also be referred to as the session initiation process or session setup process. Furthermore, the discovery, authentication, association, and security setup processes of the link setup process can be collectively referred to as the association process.

[0109] Referring to FIG. 3, an 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 search for a network it can participate in. Before joining a wireless network, the STA (300) must identify a compatible network. The process of identifying networks existing in a specific area is called scanning.

[0110] There are two types of scanning methods: active scanning and passive scanning. In active scanning, an STA (300) performing scanning transmits a probe request frame (322) to search for APs in the vicinity while moving between channels and waits for a response. A responder transmits a probe response frame (324) to the STA that transmitted the probe request frame in response to the probe request frame. Here, the responder may be an AP or STA that last transmitted a beacon frame in the BSS of the channel being scanned. In FIG. 3, an example of a BSS that becomes a responder is shown because an AP (310) transmits a beacon frame (320), and in an IBSS, STAs within the IBSS take turns transmitting beacon frames, so the responder is not constant. 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 BSS-related information included in the received probe response frame and move to the next channel to perform scanning in the same manner.

[0111] The scanning operation can also be performed in a passive scanning manner. In passive scanning, the STA performing the scanning moves through channels and detects beacon frames. A beacon frame is one of the management frames in IEEE 802.11, and is periodically transmitted to announce the presence of a wireless network and to enable the STA performing the scanning to find the wireless network and participate in the wireless network. FIG. 3 illustrates an example of a BSS in which an AP (310) periodically transmits a beacon frame (320) to an STA (300), and in an IBSS, STAs within the IBSS take turns transmitting beacon frames. When the STA performing the scanning receives a beacon frame, it stores information about the BSS included in the beacon frame and moves to another channel, recording the beacon frame information on each channel. Comparing active and passive scanning, active scanning has the advantage of lower delay and power consumption than passive scanning.

[0112] 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 below. The authentication process includes a process in which the STA (300) transmits an authentication request frame (330) to the AP (310), and in response, the AP (310) transmits an authentication response frame (332) to the STA (300). The authentication frame used for the authentication request / response corresponds to a management frame.

[0113] The authentication frame may include information such as an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a Robust Security Network (RSN), and a Finite Cyclic Group. These are just some examples of information that may be included in an authentication request / response frame, and may be replaced with other information or include additional information.

[0114] The AP (310) may determine whether to allow authentication for the STA based on information included in the received authentication request frame. The AP (310) may provide the result of the authentication process to the STA (300) via an authentication response frame.

[0115] After the STA is successfully authenticated, an association process can be performed. The association process includes a process in which the STA (300) transmits an association request frame (340) to the AP (310), and in response, the AP (310) transmits an association response frame (342) to the STA (300).

[0116] For example, the association request frame may include information related to various capabilities, such as beacon listen interval, SSID, supported rates, supported channels, robust security network (RSN), mobility domain, supported operating classes, traffic indication map broadcast request, and interworking service capabilities.

[0117] For example, the association response frame may include information related to various capabilities, status codes, association ID (AID), supported rates, enhanced distributed channel access (EDCA) parameter sets, received channel power indicator (RCPI), received signal to noise indicator (RSNI), mobility domains, timeout interval (association comeback time), overlapping BSS scan parameters, TIM broadcast response, QoS maps, etc.

[0118] These are just some examples of information that may be included in a request / response frame, and may be replaced by other information or include additional information.

[0119] Although not shown, after the STA successfully associates with the network, a security setup process may be performed. The security setup process may be referred to as an authentication process via a robust security network association (RSNA) request / response, the authentication process (330) may be referred to as a first authentication process, and the security setup process may also be referred to as an authentication process.

[0120] The security setup process may include, for example, a private key setup process through a four-way handshaking using an extensible authentication protocol over LAN (EAPOL) frame, or may be performed according to a security method not defined in the IEEE 802.11 standard.

[0121] Below we describe the media access control protocol provided by 802.11.

[0122] In wireless LAN systems based on IEEE 802.11, the basic access mechanism of MAC is based on the distributed coordination function (DCF) that utilizes 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. Physical carrier sense is a method in which the physical layer detects the channel status and notifies the MAC layer, and virtual carrier sense is a method in which the channel occupancy time is broadcast to neighboring stations to reserve the channel in advance. An STA or AP that has secured a transmission channel records and transmits this channel occupancy time within the RTS or / and CTS or data frame. Other STAs that receive this determine that the channel is busy during this time and do not compete for the channel, thereby avoiding collisions.

[0123] The physical carrier sensing method basically adopts 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 or carrier or medium for a predetermined time period before starting transmission. The predetermined time period is called an inter frame space (IFS) and can vary depending on the priority of the traffic to be transmitted. That is, the priority can be determined by the length of the time period, and the higher the priority packet, the shorter the time period can be.

[0124] The above IFS may include a short IFS (SIFS), a priority IFS (PIFS), a distributed (coordination function) IFS (DIFS), an arbitration IFS (AIFS), etc. The SIFS is the shortest time interval and may be mainly used as a waiting time for control information. The PIFS is a medium-length time interval and may be for a packet with a medium priority (PIFS = SIFS + 1 slot time). The DIFS is the longest time interval compared to the SIFS and PIFS, has a low priority, and may be mainly used as a waiting time for checking whether a channel is in use (DIFS = SIFS + 2 slot time). That is, for example, an STA that wishes to perform transmission may listen to whether a channel is in use (or detect the channel) during the DIFS period.

[0125] Based on the sensing result, if the medium is determined to be in an idle state, the AP and / or STA initiate frame transmission through the medium. On the other hand, if the medium is detected to be in an occupied state, the AP and / or STA may not initiate its own transmission, but may wait for a delay period (e.g., a random backoff period) for medium access before attempting frame transmission. By applying a random backoff period, multiple STAs are expected to attempt frame transmission after waiting for different periods of time, thereby minimizing collisions.

[0126] However, since this DCF method does not consider the priority between STAs, it has a problem in that it is difficult to support various types of data transmission and QoS (Quality of Service), so the hybrid coordination function (HCF) was introduced. HCF is based on the DCF and the point coordination function (PCF). PCF is 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), which is a contention-based channel access method, and HCCA (HCF controlled channel access), which is a contention-free method using a polling mechanism. In addition, HCF includes a medium access mechanism to improve the QoS of WLAN, and can transmit QoS data in both a contention period (CP) and a contention-free period (CFP).

[0127] FIG. 4 is a diagram 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 a CTS for solving the problem of the hidden node and the exposed node.

[0128] 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 may determine that the medium is idle when performing carrier sensing before STA C sends data to STA B, even though STA A is transmitting the information to STA B. This is because STA A's transmission (i.e., medium occupancy) may not be sensed at STA C's location. In this case, STA B receives information from STA A and STA C simultaneously, resulting in a collision. In this case, STA A can be said to be a hidden node of STA C.

[0129] (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 may determine that the medium is occupied due to the transmission of 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, STA A is outside the transmission range of STA C, so the transmission from STA C and the transmission from STA B may not collide from the perspective of STA A, and thus STA C unnecessarily waits until STA B stops transmitting. In this case, STA C can be called an exposed node of STA B.

[0130] In order to effectively utilize the collision avoidance mechanism in the above situation, short signaling packets such as RTS (request to send) and CTS (clear to send) can be utilized. An STA that wishes to transmit data transmits an RTS to an STA that will receive the data, and the receiving STA that receives the RTS responds to the transmitting STA with a CTS frame. The RTS and / or CTS between two STAs can be overheard by surrounding STA(s), allowing the surrounding STA(s) to consider whether information should be transmitted between the two STAs.

[0131] (c)(420) is an example of a method for solving the hidden node problem. Assume that both STA A and STA C want to transmit data to STA B. When STA A transmits an RTS to STA B, STA B transmits a CTS to STA A. STA C, which overhears the RTS and CTS, delays its medium access until STA A and STA B finish transmitting data, thereby avoiding collisions.

[0132] (d)(430) is an example of a method for solving the exposed node problem. STA B, which wants to transmit data to STA A, transmits an RTS, and STA A, which is to receive the data, can respond to the RTS by transmitting a CTS. In this case, if STA C receives only the RTS transmitted by STA B and does not receive the CTS transmitted by STA A, STA C can know that STA A is outside the carrier sensing area of ​​STA C. In this case, STA C can determine that no collision will occur even if it transmits data to another STA (e.g., STA D), and can transmit the data.

[0133] FIG. 5 is a diagram illustrating an example of a frame structure used in an IEEE 802.11 system to which various embodiments of the present disclosure are applicable.

[0134] The PPDU (physical layer protocol data unit) format can be composed of a short training field (STF), a long training field (LTF), a SIGNAL (SIG) field, and a data field. The most basic (e.g., non-HT (high throughput)) PPDU frame format can be composed of only the legacy-STF (L-STF), legacy-LTF (L-LTF), a SIG field, and a data field.

[0135] 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. The STF and LTF can be collectively called the PLCP preamble, which is a signal for OFDM physical layer synchronization and channel estimation.

[0136] The SIG field can be used to transmit control information for demodulation and decoding of the data field. The SIG field can include information about the data rate and data length. Additionally, the SIG field can include a parity bit, a SIG TAIL bit, etc.

[0137] The data field may include a SERVICE field, a physical layer service data unit (PSDU), a PPDU TAIL bit, and, if necessary, padding bits. Some bits of the SERVICE field may be used for a descrambler at the receiver. The PSDU corresponds to an MPDU (mac protocol data unit) defined at the MAC layer and may contain data generated / used by upper layers. The PPDU TAIL bit may be used to return the encoder to a 0 state. The padding bit may be used to adjust the length of the data field to a predetermined unit.

[0138] MPDU is defined according to various MAC frame formats, and a basic MAC frame consists of a MAC header, frame body, and FCS (frame check sequence). MAC frame is composed of MPDU and can be transmitted / received through PSDU of the data part of PPDU format.

[0139] The MAC header is defined as an area that includes 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.

[0140] The Frame Control field contains information about the characteristics of the corresponding MAC frame. The Segment / Identifier field may be implemented to have different values ​​depending on the type and subtype of the corresponding MAC frame.

[0141] The Address 1 field to the Address 4 field are used to indicate the BSSID, source address (SA), destination address (DA), transmitting address (TA) indicating the transmitting STA address, and receiving address (RA) indicating the receiving STA address.

[0142] The sequence control field is set to include a sequence number and a fragment number. The sequence number can indicate the sequence number assigned to the corresponding MAC frame. The fragment number can indicate the number of each fragment of the corresponding MAC frame.

[0143] The QoS Control field contains information related to QoS. The QoS Control field may be included when 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.

[0144] 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 is 11,454 octets, and the maximum PPDU size can be 5.484 ms.

[0145] FCS is defined as a MAC footer and is used to detect errors in MAC frames.

[0146] The first three fields (Frame Control, Segment / Identifier, and Address 1) and the last field (FCS) constitute the minimum frame format and are present in all frames. The remaining fields may only be present in certain frame types.

[0147] Below is a description of the network allocation vector (NAV) used in wireless LAN networks.

[0148] As mentioned above, the CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing, in which the AP and / or STA directly sense the medium. Virtual carrier sensing is intended to address potential issues in medium access, such as the hidden node problem. For virtual carrier sensing, the MAC of the wireless LAN system can utilize NAV. NAV is a value that indicates to other APs and / or STAs the remaining time until the medium becomes available, by the AP and / or STA currently using or authorized to use 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 the period. NAV can be set, for example, according to the value of the duration field of the MAC header of the frame.

[0149] FIG. 6 is a diagram illustrating an example of NAV settings to which various embodiments of the present disclosure can be applied.

[0150] Referring to FIG. 6, a source STA (source STA, 600) transmits an RTS frame after DIFS, and a destination (destination) (610) transmits a CTS frame after SIFS. The destination STA designated as the receiver through the RTS frame does not set an NAV. Some of the remaining STAs (620) may receive the RTS frame and set an NAV (630), and some may receive the CTS frame and set an NAV (640).

[0151] If a CTS frame (e.g., PHY-RXSTART.indication primitive) is not received within a certain period from the time when the RTS frame is received (e.g., the time when the MAC receives the PHY-RXEND.indication primitive corresponding to the RTS frame), STAs that have set or updated the NAV through the RTS frame may reset the NAV (e.g., to 0). The certain period may be (2*aSIFSTime + CTS_Time + aRxPHYStartDelay + 2*aSlotTime). The CTS_Time may be calculated based on the length of the CTS frame and the data rate indicated by the RTS frame. The certain period may be a NAVTimeout period.

[0152] In Fig. 6, for convenience, setting or updating NAV through an RTS frame or a CTS frame is illustrated, but NAV setting / resetting / updating may also be performed based on various other frames, such as a non-HT PPDU, HT PPDU, VHT PPDU, or an interval field of a HE PPDU (for example, an interval field in a MAC header of a MAC frame).

[0153] 802.11ax also introduces basic NAV and intra-BSS NAV. Basic NAV is always set by frames transmitted by APs or STAs other than itself (mandatory), and intra-BSS NAV can be optionally set by frames transmitted from the BSS to which the AP or STA belongs. An AP or STA can access the medium when both NAV timers have expired (or after all NAV time intervals have elapsed).

[0154] Below, we describe TXOP (transmission opportunity). TXOP is a new feature introduced in the 802.11e MAC to ensure QoS and improve channel utilization. To ensure QoS, TXOP can be used to assign priority transmission opportunities when two or more packets fall into the same access category (AC).

[0155] FIG. 7 is a diagram illustrating an example of a TXOP to which various embodiments of the present disclosure can be applied.

[0156] STAs participating in QoS transmission can obtain TXOPs, which allow them to transmit traffic for a certain period of time, using two channel access methods: EDCA and HCCA. TXOPs can be acquired either by successfully competing in EDCA or by receiving a QoS CF-Poll (Contention-Free Poll) frame from the AP. The former is called an EDCA TXOP, and the latter a Polled TXOP. In this way, the concept of TXOP can be used to grant a certain amount of time for a STA to transmit a frame, or to forcibly limit the transmission time.

[0157] The transmission start time and maximum transmission time of TXOP are determined by the AP, which is notified to the STA by a beacon frame for EDCA TXOP and by a QoS CF-Poll frame for Polled TXOP.

[0158] NAV can be understood as a kind of timer to protect the TXOP of a transmitting STA (e.g., a TXOP holder). An STA can protect the TXOP of another STA by not performing channel access while the NAV set for itself is valid. In the current wireless LAN system, the TXOP duration is set through the duration field of the MAC header. That is, the TXOP holder and the TXOP responder (e.g., the Rx STA) transmit the entire TXOP information required for transmitting and receiving frames by including it in the duration field of the frames they transmit and receive. Third-party STAs that are not the TXOP holder or the TXOP responder (e.g., third-party STAs) check the Duration field of the frames exchanged between the TXOP holder and the TXOP responder, and postpone channel use until the NAV duration by setting / updating the NAV.

[0159] Below we describe the 802.11be standard. 802.11be, also known as EHT (extremely high throughput), operates in the 2.4, 5, and 6 GHz bands and is being developed to provide speeds up to 46 Gbps, which is 4.8 times faster than WiFi 6, by introducing 320 MHz of bandwidth, 4096QAM, multiple resource units (RUs), and multi-link operation (MLO), while providing low latency and high network throughput. Specifically, 802.11be provides a wide bandwidth of 320 MHz in the 6 GHz band, and can transmit data via MU-MIMO with 16 spatial streams in both the uplink and downlink, and adopts 4096QAM to achieve high transmission efficiency. In addition, it has the characteristics of increasing spectrum efficiency by flexibly performing spectrum resource scheduling through multiple RUs, and simultaneously transmitting and receiving data in various frequency bands and channels through multi-link operation.

[0160] FIG. 8 is a diagram showing an example of a TDLS to which various embodiments of the present disclosure can be applied.

[0161] TDLS (tunneled direct-link setup) is a protocol that uses a specific Ethertype encapsulation to establish a TDLS direct link through an AP by sending a TDLS frame. An STA that transmits a TDLS Setup Request frame or a TDLS Discovery Request frame is called a TDLS initiator STA, and an STA that receives or is intended to receive a TDLS Setup Request frame or a TDLS Discovery Request frame is called a TDLS responder STA.

[0162] To establish and maintain a direct link, TDLS peer STAs can be associated with the same infrastructure BSS.

[0163] The TDLS Setup Request frame, TDLS Setup Response frame, and confirm frame (TDLS Setup Confirm frame) can be transmitted and received through the AP. The TDLS Discovery Request frame can be transmitted and received through the AP, and the TDLS Discovery Response frame can be transmitted directly (i.e., without going through the AP) to the TDLS peer STA that transmitted the corresponding TDLS Discovery Request frame.

[0164] A TDLS initiator STA can transmit a TDLS Setup Request frame to a TDLS responder STA through an AP. The TDLS responder STA can transmit a TDLS Setup Response frame to the TDLS initiator STA through the AP in response to the TDLS Setup Request frame. If the TDLS responder STA acknowledges the TDLS Setup Request frame, the TDLS Setup Response frame includes a status code of SUCCESS. The TDLS initiator STA can transmit a TDLS Setup Confirm frame to the TDLS initiator STA through the AP. The TDLS initiator STA can transmit a TDLS Setup Confirm frame to the TDLS initiator STA through the AP to confirm receipt of the TDLS Setup Request frame.

[0165] After the TDLS setup handshake is completed, the TDLS initiator STA and the TDLS responder STA become TDLS peer STAs. A TDLS peer STA can acknowledge data frames received directly from each TDLS peer STA, and data frames destined for each TDLS peer STA can be transmitted over the direct connection (TDLS link).

[0166] The base channel is the primary channel of the AP with which the TDLS peer STA is associated. An off-channel is a channel used by a TDLS STA that is not the primary channel of the AP with which the TDLS STA is associated. The primary channel on which the AP operates is called the base channel, and a TDLS STA operating on this channel may be operating on the base channel. If the direct connection switches to a channel other than the base channel, this channel may be called an off-channel, and a TDLS STA operating on this channel may be operating on the off-channel.

[0167] FIG. 9 is a diagram illustrating an example of TDLS channel switching to which various embodiments of the present disclosure are applicable. By exchanging a TDLS channel switch request and a TDLS channel switch response, a peer STA can move to an off-channel. The TDLS channel switch request frame and the TDLS channel switch response frame can be transmitted through a direct connection. The destination channel of the intended channel switch is called a target channel. The target channel can be designated by the STA initiating the channel switch. The target channel can be designated in the TDLS channel switch request.

[0168] TDLS peer STAs STA1 and STA2 can operate on an initial channel (910). After contention for the medium (920), STA1 can transmit a TDLS channel switch request frame to STA2 via a direct connection (930). The TDLS channel switch request frame can indicate that a switch to a target channel is requested. STA2 can transmit an ACK frame (ACK1) after an SIFS (940). STA2 can process the TDLS channel switch request frame (950). After contention for the medium (960), STA2 can transmit a TDLS channel switch response frame to STA1 (970). STA1 can transmit an ACK frame (ACK2) after an SIFS (980). If the TDLS channel switch response frame indicates status code REQUEST_DECLINED, STA1 and STA2 continue operation on the current channel. If the TDLS channel switch response frame indicates status code SUCCESS, STA1 and STA2 can switch to the target channel (990).

[0169] A peer STA may be required to be in power save (PS) mode with the AP before transmitting a request (TDLS channel switch request frame) or a response (TDLS channel switch response frame). That is, the peer STA may enter PS mode before transmitting the request and response, and may not receive transmissions from the AP. In addition, each peer STA may be required to perform contention (contention for the medium) before transmitting a request (TDLS channel switch request frame) or a response (TDLS channel switch response frame).

[0170] FIG. 10 and FIG. 11 are drawings for explaining a PS (power save) mode to which various embodiments of the present disclosure are applicable.

[0171] Figure 10 illustrates the structure of a VHT-SIG-A1 (very high throughput signal A1) field. The VHT-SIG-A1 field may include a BW (bandwidth) field (2 bits, B0 to B1), a Reserved field (1 bit, B2), a STBC (space-time block coding) field (1 bit, B3), a Group ID field (6 bits, B4 to B9), a NSTS (Number of Space-Time Streams) / Partial AID field (12 bits, B10 to B21), a TXOP_PS_NOT_ALLOWED field (1 bit, B22), and a Reserved field (1 bit, B23).

[0172] If the VHT AP allows a non-AP VHT STA in TXOP power save mode to doze during a TXOP, TXOP_PS_NOT_ALLOWED is set to 0. Otherwise, it is set to 1. If the VHT PPDU is transmitted by a non-AP VHT STA, TXOP_PS_NOT_ALLOWED is reserved and set to 1.

[0173] The NSTS / Partial AID field is structured as follows:

[0174] For VHT MU (multi-user) PPDU, NSTS is divided into four User positions of 3 bits each. User position p (0 ≤ p ≤ 3) uses bits B(10+3p) to B(12+3p). Each User position is set to 0 for 0 space-time streams; 1 for 1 space-time stream; 2 for 2 space-time streams; 3 for 3 space-time streams; 4 for 4 space-time streams; and values ​​5 through 7 are reserved.

[0175] For VHT SU (single-user) PPDUs, B10 to B12 are set to 0 for 1 space-time stream; 1 for 2 space-time streams; 2 for 3 space-time streams; 3 for 4 space-time streams; 4 for 5 space-time streams; 5 for 6 space-time streams; 6 for 7 space-time streams; 7 for 8 space-time streams. B13 to B21 represent Partial AIDs. The Partial AID provides an abbreviated indication to the recipient of the PSDU.

[0176] The Group ID field indicates a VHT SU PPDU if it is 0 or 63, otherwise it indicates a VHT MU PPDU. A Group corresponding to a Group ID field can contain up to four STAs.

[0177] An STA can be in one of two power states:

[0178] - Awake: STA is fully powered

[0179] - Doze: STA is in a state where it cannot transmit or receive and consumes very low power.

[0180] A non-AP STA may enter a doze state for the remaining TXOPs if it determines that the non-AP STA is not the intended recipient of the PPDU. TXOP_PS_NOT_ALLOWED may be set to 0.

[0181] For VHT SU PPDU, PAID (partial AID) can be used to determine whether STA1 is intended to be the recipient of the VHT SU PPDU. For example, if the PAID of the VHT SU PPDU transmitted from the AP indicates STA1, STA1 may be the recipient of the VHT SU PPDU. STA1 may transmit an IR (immediate response) to the VHT SU PPDU. If the PAID corresponding to the VHT SU PPDU transmitted from the AP does not indicate STA1, STA1 may not be the recipient of the VHT SU PPDU. STA1 may enter the doze state after it is confirmed that STA1 is not the intended recipient of the VHT SU PPDU (e.g., after confirming VHT-SIG-A).

[0182] For VHT MU PPDU, Group ID and User position can be used to determine whether STA1 is intended to be the receiver of the VHT MU PPDU. For example, if STA1 is included in the Group corresponding to the Group ID of the VHT MU PPDU transmitted from the AP, and the value of the User position corresponding to STA1 among the User positions is 1 or greater, STA1 may be the receiver of the VHT MU PPDU. STA1 may transmit an IR for the VHT MU PPDU. For example, if STA1 is included in the Group corresponding to the Group ID of the VHT MU PPDU transmitted from the AP, and the value of the User position corresponding to STA1 among the User positions is 0, or if STA1 is not included in the Group corresponding to the Group ID of the VHT MU PPDU transmitted from the AP, STA1 may not be the receiver of the VHT MU PPDU. STA1 can enter doze state after it confirms that STA1 is not the recipient of VHT MU PPDU (e.g., after confirming VHT-SIG-A).

[0183] FIG. 12 is a diagram illustrating an example of channel access to which various embodiments of the present disclosure may be applied. FIG. 12 is for explaining non-primary channel access (NPCA). In FIG. 12, a wideband channel is illustrated as consisting of a 20 MHz primary channel (primary 20 MHz channel) and multiple 20 MHz secondary channels (secondary 20 MHz channels). This is for convenience of explanation and the present disclosure is not limited thereto.

[0184] A primary channel is a common channel operated by all STAs that are members of a BSS. For example, in a 20 MHz, 40 MHz, 80 MHz, 160 MHz, or 80 + 80 MHz BSS, the primary channel may be the primary 20 MHz channel.

[0185] A secondary channel is a channel associated with a primary channel and is used to create a wider channel than the primary channel. For example, in a 40 MHz, 80 MHz, 160 MHz, or 80 + 80 MHz BSS, the secondary channel may be a secondary 20 MHz channel.

[0186] Existing wireless LAN networks experience significant performance degradation, including transmission rates, as users increase. This is because wireless LAN systems fundamentally utilize CSMA / CA, which corresponds to time-division access control. Therefore, when a neighboring network is detected, frequency resources in the same band are divided and used based on the activity time of the neighboring network. Currently, multiple APs often operate in a given area, and in this case, coverage overlap between APs can degrade the performance of the wireless LAN network. This is because the APs of each BSS and the STAs connected to the APs are affected by the signals of the neighboring BSS, resulting in interference from neighboring BSSs, which in turn leads to a reduction in transmission rates due to collisions between signals transmitted at the same time. BSSs that can affect signal transmission in this way (or whose coverage overlaps) can be referred to as overlapping BSSs (OBSSs).

[0187] According to the current 801.11 standard, for any transmission (e.g., transmission on 20 / 40 / 80 / 160 / 320MHz channels), the primary channel (primary 20MHz channel) must be idle to allow access to wideband channels larger than 20MHz. Therefore, if the primary channel is busy, the AP / STA cannot transmit on any idle secondary channel. In other words, if the primary channel is busy, no transmission can be performed on the secondary channel even if the secondary channel is idle.

[0188] For example, referring to FIG. 12(a), even if the secondary channel is available, transmission cannot be performed if the primary channel is busy.

[0189] For example, the primary channel may be busy due to interference from a 20MHz PPDU corresponding to an overlapping BSS (OBSS), in which case transmission cannot be performed even if secondary channels of 60MHz are available.

[0190] For example, the primary channel may be busy due to interference from a 40MHz PPDU corresponding to an OBSS, in which case transmission cannot be performed even if the 40MHz secondary channels are available.

[0191] That is, according to the current 801.11 standard, when the primary channel is idle, the STA can transmit packets. That is, when the primary channel is idle, the STA can perform transmission (e.g., transmission of 80MHz PPDU) using the primary channel and the secondary channel. This applies equally to the UL (uplink) transmission of the STA as well as the DL (downlink) transmission of the AP.

[0192] Therefore, the current secondary channel access mechanism (or scheme) is inefficient for wideband channels (e.g., 160MHz channel, 320MHz channel) or large bandwidth, and a better secondary channel access mechanism (or scheme) is required to fully utilize wideband channels.

[0193] Non-primary channel access (NPCA) is being discussed as a solution to the above-mentioned problems. NPCA can be triggered based on OBSS PPDUs and / or OBSS TXOPs. According to NPCA, if the primary channel is busy and the secondary channel is available, the AP / STA can transmit on the available secondary channel.

[0194] An NPCA primary channel may be defined among the secondary channels (or within the secondary channels). The NPCA primary channel may be a channel on which channel access (e.g., EDCA) is performed while the primary channel is busy. That is, the NPCA primary channel may be a 20 MHz channel on which channel access is performed while the primary channel is busy within the secondary channels. The NPCA primary channel may be referred to as an anchor channel, but the present disclosure is not limited to this specific name.

[0195] For example, referring to FIG. 12(b), when the primary channel is busy, transmission can be performed on available secondary channels.

[0196] For example, if the primary channel is busy due to interference by a 20MHz PPDU corresponding to an OBSS, the STA can transmit packets (e.g., 60MHz PPDU) on available secondary channels while the primary channel is busy. Channel access can be performed on an anchor channel within the secondary channels, thereby allowing packets to be transmitted on the secondary channels when the anchor channel is idle. This applies equally to UL transmissions of the STA as well as DL transmissions of the AP.

[0197] For example, if the primary channel is busy due to interference by a 40MHz PPDU corresponding to an OBSS, the STA can transmit packets (e.g., 40MHz PPDU) on available secondary channels while the primary channel is busy. Channel access can be performed on an anchor channel within the secondary channels, thereby allowing packets to be transmitted on the secondary channels when the anchor channel is idle. This applies equally to UL transmissions of the STA as well as DL transmissions of the AP.

[0198] Secondary channels on which NPCA will operate between APs and / or STAs within a BSS and an anchor channel (e.g., a 20 MHz anchor channel) on which channel access (e.g., EDCA) procedures will be performed within the secondary channels may be pre-configured / pre-agreed upon. The secondary channels on which NPCA operates may be referred to as NPCHs (non-primary channels), but the present disclosure is not limited to such specific designations.

[0199] FIG. 13 is a diagram illustrating an example of an NPCA operation to which various embodiments of the present disclosure can be applied.

[0200] As described above, according to the existing 802.11, if the primary channel (primary 20MHz channel) is busy, access to the secondary channel is not possible. On the other hand, according to NPCA, if the primary channel is busy, the STA can compete on the NPCA primary channel (anchor channel).

[0201] Referring to FIG. 13, an AP and / or a non-AP STA can perform NPCA when the primary 20 MHz is busy by an OBSS, which can be detected or heard by the AP and / or a non-AP STA. After a certain time for channel switching, medium synchronization, etc., contention on the anchor channel can be achieved to secure the channel, and transmission on the anchor channel can then be performed. One or more frames can be exchanged between the AP and the non-AP STA for or during the NPCA operation.

[0202] FIG. 14 is a diagram illustrating an example of an NPCA operation to which various embodiments of the present disclosure are applicable. FIG. 14 illustrates a first type of NPCA operation to which various embodiments of the present disclosure are applicable, TXOP-based NPCA.

[0203] Referring to FIG. 14, OBSS ICF, OBSS ICR, OBSS PPDU, OBSS BA may be transmitted on the primary 20 MHz channel (OBSS TXOP 1). Alternatively, OBSS ICF, OBSS ICR, OBSS PPDU, OBSS BA, CF-End may be transmitted on the primary 20 MHz channel (OBSS TXOP 2). An electronic device (NPCA STA: AP and / or non-AP STA) may initially attempt to connect to the primary 20 MHz channel, but may detect an OBSS ICF-ICR exchange. An OBSS TXOP (OBSS TXOP 1, 2) may be obtained from the exchange of OBSS ICF / ICR. Alternatively, an OBSS TXOP may be obtained from an OBSS PPDU.

[0204] The electronic device can move to the anchor channel when the OBSS TXOP is confirmed and can return to the primary 20 MHz channel at or before the end of the OBSS TXOP. The electronic device can acquire the NPCA TXOP through contention on the anchor channel after t1 from the start of the OBSS ICR. The NPCA TXOP can end before t2 from the end of the OBSS TXOP (OBSS TXOP 1). t1 and t2 can be defined as follows.

[0205] t1: aRxPHYStartDelay + channel switching time + medium sync delay

[0206] t2: channel switching time

[0207] aRxPHYStartDelay is a delay, in microseconds (ms), from the start of the PPDU at the receiver's antenna to the issuance of the PHY-RXSTART.indication primitive. PHY-RXSTART.indication is an indication by the PHY to the local MAC entity that the PHY has received a valid start of a PPDU, including a valid PHY header. Channel switching time is the switching time from the primary channel to the anchor channel (or NPCH), or from the anchor channel (or NPCH) to the primary channel. Medium sync delay is the delay time for medium synchronization of electronic devices. In the case of RTS, transmission and reception can be performed without medium sync delay, and therefore, medium sync delay can be ignored in the case of RTS.

[0208] For TXOP-based NPCA, there may be a potential issue that the electronic device may remain on the anchor channel even if the OBSS TXOP is truncated. For example, even if OBSS TXOP 2 is terminated early by CF-End, the electronic device may remain on the anchor channel within the truncated TXOP duration of OBSS TXOP 2 initially obtained from the OBSS ICF / ICR exchange. In other words, the NPCA TXOP may not be terminated. As a result, the opportunity to participate in the primary 20 MHz channel may be lost. In addition, medium synchronization may be lost, and interference may occur with the OBSS TXOP.

[0209] FIG. 15 is a diagram illustrating an example of an NPCA operation to which various embodiments of the present disclosure are applicable. FIG. 15 illustrates a second type of NPCA operation to which various embodiments of the present disclosure are applicable, namely PPDU-based NPCA (or PHY Header-based NPCA).

[0210] Referring to Fig. 15, OBSS ICF, OBSS ICR, OBSS PPDU, and OBSS BA can be transmitted on the primary 20 MHz channel (OBSS TXOP). An electronic device (NPCA STA: AP and / or non-AP STA) initially attempts to connect to the primary 20 MHz channel, but can detect an OBSS ICF-ICR exchange. Afterwards, the electronic device can detect an OBSS PPDU. The OBSS PPDU section can be obtained from the preamble of the OBSS PPDU.

[0211] After verifying the OBSS PPDU period, the electronic device can move to the anchor channel and return to the primary 20 MHz channel at or before the end of the OBSS PPDU. The electronic device can acquire the NPCA TXOP through contention on the anchor channel after t3 or t4 from the start of the OBSS PPDU. The NPCA TXOP can end before t2 from the end of the OBSS PPDU. t2, t3, and t4 can be defined as follows.

[0212] t2: channel switching time

[0213] t3: time required to obtain PPDU duration + channel switching time + medium sync delay

[0214] t4: t3 - medium sync delay

[0215] Channel switching time is the switching time from the primary channel to the anchor channel (or NPCH) or from the anchor channel (or NPCH) to the primary channel. Medium sync delay is the delay time for medium synchronization of electronic devices.

[0216] For PPDU-based NPCA, the potential problem of TXOP-based NPCA described above can be resolved. That is, the potential problem of electronic devices remaining on the anchor channel even when the OBSS TXOP is reduced can be resolved. However, more frequent backoff and channel switching procedures may occur, and NPCA may not be applicable to short frames (e.g., PPDUs with PPDU duration < threshold), which may reduce the gains of NPCA.

[0217] A comparison of TDLS channel switching and NPCA is as follows. TDLS channel switching may require frame exchange in advance. As described in Fig. 9, when moving to a target channel in TDLS channel switching, TDLS channel switch request frames, TDLS channel switch response frames, etc. may need to be exchanged between peer STAs. Therefore, the primary channel may need to be available during the frame exchange. On the other hand, NPCA does not require frame exchange in advance. That is, when the primary channel is unavailable, the STA can move to a predetermined channel (e.g., an anchor channel) and communicate.

[0218] According to various embodiments of the present disclosure, peer STAs can perform communication on an anchor channel through NPCA-based channel switching. When the primary channel is unavailable, the peer STAs can perform peer-to-peer (P2P) communication on the anchor channel through NPCA-based channel switching. The anchor channel and switching conditions can be determined in advance according to one embodiment of the present disclosure. The primary channel for P2P can be a base channel and / or an off channel.

[0219] According to various embodiments of the present disclosure, a method for setting an anchor channel for a base channel and / or an off-channel between peer STAs may be provided. According to various embodiments of the present disclosure, a method for exchanging information required for NPCA-based channel switching may be provided. According to various embodiments of the present disclosure, channel switching conditions for NPCA-based channel switching triggers may be provided.

[0220] FIG. 16 is a diagram illustrating an example of NPCA-based channel switching according to one embodiment of the present disclosure.

[0221] An NPCA-based channel switch according to one embodiment of the present disclosure may be applied to both OBSS and Intra-BSS cases. This is for illustrative purposes only and the present disclosure is not limited thereto.

[0222] An OBSS case is described. The OBSS case may be a case in which the base channel and / or off-channel are busy by an OBSS different from the BSS including the peer STA. STA1 and STA2 included in the BSS of the AP may have established a TDLS-based P2P link. Here, when an OBSS transmission by the OBSS AP and / or OBSS STA is detected, the base channel or off-channel corresponding to the P2P link may be busy. In this case, STA1 and STA2 may perform NPCA-based channel switching according to an embodiment of the present disclosure.

[0223] An intra-BSS case is described. An intra-BSS case may be a case where the base channel and / or off-channel is busy due to another STA within a BSS including a peer STA. STA2 and STA3 within the BSS of an AP may have established a TDLS-based P2P link. Here, if a transmission (intra-BSS transmission) between STA1 within the BSS of the AP and the AP is detected, the base channel or off-channel corresponding to the P2P link may be busy. In this case, STA2 and STA3 may perform NPCA-based channel switching according to an embodiment of the present disclosure.

[0224] According to one embodiment of the present disclosure, when the base channel (and / or off channel) is busy due to OBSS transmission and / or Intra-BSS transmission, a peer STA may perform an NPCA-based channel switch.

[0225] According to one embodiment of the present disclosure, the anchor channel for TDLS and the infrastructure anchor channel may be different. Here, the infrastructure anchor channel may refer to an anchor channel in NPCA in an infrastructure network that considers communication between an AP and a STA (non-AP STA). And / or, the anchor channel for the base channel and the anchor channel for the off-channel may be different.

[0226] NPCA-based channel switching according to one embodiment of the present disclosure may follow any possible NPCA operation. For example, whether to move to the anchor channel in some cases and / or to return to the primary channel in some cases and / or to perform PPDU-based NPCA and / or TXOP-based NPCA may follow any possible NPCA operation.

[0227] An NPCA-based channel switching from a base channel according to one embodiment of the present disclosure is described. The information required to activate NPCA-based channel switching from a base channel may be as follows. At least some of the information below may be required.

[0228] - Capability: Capability information for NPCA-based channel switching and / or capability information for NPCA-based channel switching from the base channel. This may be information about the NPCA-based channel switching capability of a peer STA and / or capability for NPCA-based channel switching from the base channel.

[0229] - Anchor channel for TDLS (an anchor channel for base channel TDLS. TDLS anchor channel). It may be a TDLS anchor channel corresponding to the base channel. Unless specifically stated otherwise, the anchor channel and TDLS anchor channel may be used interchangeably in the description of an embodiment of the present disclosure.

[0230] - Channel width and / or channel frequency (center frequency) of TDLS NPCH: Information about TDLS NPCH (base channel TDLS NPCH) including TDLS anchor channel (anchor channel for base channel TDLS). Unless specifically stated otherwise, in the description of one embodiment of the present disclosure, operating on the TDLS anchor channel may mean operating on the TDLS NPCH, and performing transmission on the TDLS anchor channel may mean performing transmission on the TDLS NPCH.

[0231] - Channel switch time: Information about the time corresponding to the switch from the base channel to the TDLS anchor channel (and / or TDLS NPCH).

[0232] - Channel switch back time: Information about the time corresponding to the switch back from the TDLS anchor channel (and / or TDLS NPCH) to the base channel - VHT Group ID and User position within the Group

[0233] According to one embodiment of the present disclosure, information necessary to activate NPCA-based switching from the base channel described above may be exchanged during the TDLS setup process and / or the TDLS setup handshake process.

[0234] According to one embodiment of the present disclosure, the TDLS Setup Request frame, the TDLS Setup Response frame and / or the confirm frame (TDLS Setup Confirm frame) may include at least some of the following information. That is, according to one embodiment of the present disclosure, at least some of the following elements may be added to the TDLS Setup Request frame, the TDLS Setup Response frame and / or the confirm frame (TDLS Setup Confirm frame). The following information / elements may correspond to information required to activate NPCA-based channel switching from the base channel described above. The names of the frames are examples, and the present disclosure is not limited thereto. For example, a TDLS Setup Request frame may be a Setup Request frame related to a direct connection and / or a P2P connection between STAs, a TDLS Setup Response frame may be a Setup Response frame related to a direct connection and / or a P2P connection between STAs, and a TDLS Setup Confirm frame may be a Confirm frame related to a direct connection and / or a P2P connection between STAs.

[0235] - NPCA-based channel switching capability: 1 bit of UHR (Ultra High Reliability) Capability. For example, if the value of bit 1 is 1 (or 0), it indicates that there is capability for NPCA-based channel switching and / or capability information for NPCA-based channel switching from the base channel, and if the value of bit 1 is 0 (or 1) (or the information is not included), it may indicate that there is no capability for NPCA-based channel switching and / or capability information for NPCA-based channel switching from the base channel. The information may indicate the capability of a peer STA that transmitted a frame including the information.

[0236] - TDLS anchor channel: 1 octet. The Target Channel field can be reused. It can indicate the TDLS anchor channel for the base channel.

[0237] - Channel switch timing elements

[0238] - Channel switchback timing element

[0239] - Channel band and / or channel frequency of TDLS NPCH

[0240] - - Bandwidth Indication element can be reused.

[0241] - - - Control: Can indicate channel bandwidth.

[0242] - - - CCFS(Channel Center Frequency Segment)0: It can represent the center frequency of a 20, 40 and / or 80 MHz channel and / or a P80 (primary 80 MHz) channel of a 160 MHz channel and / or a P160 (primary 160 MHz) channel of a 320 MHz channel.

[0243] - - - CCFS1: Can indicate the center frequency of a 160 MHz channel and / or the center frequency of a 320 MHz channel.

[0244] - VHT group ID: User Position Array field can be used.

[0245] - - User Position Array can be 16 octets containing membership information and user position of each group. Membership information can correspond to Group ID, and user position can be position in Group corresponding to Group ID. User Position Array can be used to identify whether the VHT MU PPDU is intended for a peer STA, especially in intra-BSS case when a VHT MU PPDU is transmitted.

[0246] For example, NPCA-based channel switching capability may be included in the TDLS Setup Request frame and the TDLS Setup Response frame. Channel switch timing elements, channel switch back timing elements, and User Position Array may be included in the TDLS Setup Request frame and the TDLS Setup Response frame / the TDLS Setup Response frame and the confirmation frame. Information about the TDLS anchor channel may be included in the confirmation frame, or may be included in the TDLS Setup Request frame and the confirmation frame, or may be included in the TDLS Setup Request frame, the TDLS Setup Response frame, and the confirmation frame. When the TDLS anchor channel is included in a frame other than the confirmation frame (TDLS Setup Request frame, TDLS Setup Response frame), it may be for negotiating an anchor channel between a TDLS initiator STA and a TDLS responder STA. The above-described examples are merely examples and the present disclosure is not limited thereto.

[0247] FIG. 17a is a diagram illustrating an example of a format for transmitting information required to activate NPCA-based channel switching according to one embodiment of the present disclosure.

[0248] FIG. 17b is a diagram illustrating an example of a format for transmitting information required to activate NPCA-based channel switching according to one embodiment of the present disclosure.

[0249] FIG. 17c is a diagram illustrating an example of a format for transmitting information required to activate NPCA-based channel switching according to one embodiment of the present disclosure.

[0250] Figure 17a illustrates an example of the Target Channel field format. The Target Channel field may specify the channel number of the target channel and may consist of 1 octet. According to one embodiment of the present disclosure, a TDLS anchor channel (a TDLS anchor channel for the base channel) may be indicated by the Target Channel field.

[0251] The Bandwidth Indication element format is exemplified in (a) of Fig. 17b. The Bandwidth Indication element may include an Element ID field (1 octet), a Length field (1 octet), a Bandwidth Indication Parameters field (1 octet), and a Bandwidth Indication Information field (3 or 5 octets).

[0252] According to one embodiment of the present disclosure, Bandwidth Indication Information may be used to indicate a channel band and / or channel frequency of a TDLS NPCH (TDLS NPCH for a base channel). The definition of Bandwidth Indication Information may be identical to the definition of the EHT Operation Information field of the EHT Operation element.

[0253] The EHT Operation Information field format is exemplified in (b) of Fig. 17b. The EHT Operation Information field may include a Control subfield (1 octet), a CCFS0 subfield (1 octet), a CCFS1 subfield (1 octet), and a Disabled Subchannel Bitmap subfield (0 or 2 octets). The Control subfield may include a Channel Width subfield (3 bits, B0 to B2), and a Reserved subfield (5 bits, B3 to B7). Definitions of the Channel Width subfield, CCFS0 subfield, and CCFS1 subfield of the EHT Operation Information field can be referred to Table 1.

[0254] [Table 1]

[0255]

[0256] According to one embodiment of the present disclosure, the Control subfield (within the Channel Width subfield), CCFS0, CCFS1 can be used to indicate the channel band and / or channel frequency of the TDLS NPCH (TDLS NPCH for the base channel).

[0257] According to one embodiment of the present disclosure, the Channel Width subfield within the Control subfield may define a channel band of a TDLS NPCH. It may be set to 0 for a 20 MHz channel band; 1 for a 40 MHz channel band; 2 for an 80 MHz channel band; 3 for a 160 MHz channel band; and 4 for a 320 MHz channel band. The values ​​5 to 7 may be reserved. The channel bands corresponding to the values ​​of the Channel Width subfield are merely examples, and the present disclosure is not limited thereto. For example, the corresponding values ​​and the channel bands may be changed, and at least some of the reserved values ​​5 to 7 may be used to indicate the channel band. In addition, the use of the Channel Width subfield is merely an example, and the present disclosure is not limited thereto. For example, reserved subfields within the Control subfield may also be used.

[0258] According to one embodiment of the present disclosure, CCFS0 and CCFS1 may represent the center frequency and / or primary channel of the TDLS NPCH. The values ​​of each subfield below and the corresponding channel bands are examples, and the present disclosure is not limited thereto.

[0259] For example, when the TDLS NPCH channel band is 20, 40, or 80 MHz, CCFS0 may represent a channel center frequency index of the 20, 40, or 80 MHz TDLS NPCH channel band. For example, when the TDLS NPCH channel band is 160 MHz, CCFS0 may represent a primary 80 MHz channel center frequency index of the 160 MHz TDLS NPCH channel band. For example, when the TDLS NPCH channel band is 320 MHz, CCFS0 may represent a primary 160 MHz channel center frequency index of the 320 MHz TDLS NPCH channel band.

[0260] For example, if the TDLS NPCH channel band is 20, 40, or 80 MHz, CCFS1 may be set to 0. For example, if the TDLS NPCH channel band is 160 MHz, CCFS1 may indicate the channel center frequency index of the 160 MHz TDLS NPCH channel band. For example, if the TDLS NPCH channel band is 320 MHz, CCFS1 may indicate the channel center frequency index of the 320 MHz TDLS NPCH channel band.

[0261] Figure 17c illustrates an example of the User Position Array field format. The User Position Array field may be 16 octets long. The User Position Array field may include a 2-bit User Position subfield for each of the 64 Group IDs. The User Position subfield may be indexed by the Group ID. The User Position within Group ID 0 may be indicated by 2 bits B0 to B1. The User Position within Group ID 1 may be indicated by 2 bits B2 to B3. In this way, the User Position within a specific Group ID may be indicated by 2 bits, and finally, the User Position within Group ID 63 may be indicated by 2 bits B126 to B127.

[0262] FIG. 18 is a diagram illustrating an example of an NPCA-based channel switching operation from a base channel according to one embodiment of the present disclosure. FIG. 18 illustrates an example of an NPCA-based channel switching operation by OBSS transmission.

[0263] According to one embodiment of the present disclosure, NPCA-based channel switching operation may vary depending on whether an AP has NPCA enabled. Unless otherwise specifically stated, in the description of one embodiment of the present disclosure, whether an AP has NPCA enabled may include whether the AP has the capability for NPCA. That is, unless otherwise specifically stated, in the description of one embodiment of the present disclosure, when an AP has NPCA enabled, it may include when the AP has the capability for NPCA, and when an AP has NPCA disabled, it may include when the AP does not have the capability for NPCA. Furthermore, NPCA in an AP may be enabled / disabled (e.g., dynamically enabled / disabled), and whether an AP has NPCA enabled may be identified based on this.

[0264] According to one embodiment of the present disclosure, when the AP is an NPCA-enabled AP, NPCA-based channel switching may be enabled when an OBSS transmission is not detected (inaudible) by the AP. NPCA-based channel switching may be applied when an OBSS transmission is not detected by the AP, but is detected (audible) by peer STAs. That is, NPCA-based channel switching may not be enabled when an OBSS transmission is detected (audible) by the AP. NPCA-based channel switching may not be applied when an OBSS transmission is detected by the AP, but is detected (audible) by peer STAs.

[0265] In the example of FIG. 18, OBSS transmissions can be classified into those that can be detected in area (a) and not in area (b) (hereinafter, referred to as first OBSS transmissions for convenience of explanation) and those that can be detected in areas (a) and (b) (hereinafter, referred to as second OBSS transmissions for convenience of explanation). The first OBSS transmission and the second OBSS transmission can correspond to different OBSSs. Area (a) can include STA1 and STA2, and area (b) can include an AP. Therefore, STA1 and STA2 can detect both the first OBSS transmission and the second OBSS transmission, and the AP can detect the second OBSS transmission but cannot detect the first OBSS transmission.

[0266] For the first OBSS transmission, STA1 and STA2 may detect it, but the AP may not detect it. Therefore, in this case, STA1 and STA2 may perform NPCA-based channel switching, occupy the TDLS NPCH and perform transmission based on competition on the TDLS anchor channel.

[0267] For the second OBSS transmission, STA1 and STA2 can detect it, and the AP can also detect it. Therefore, in this case, STA1 and STA2 may not be able to perform NPCA-based channel switching for TDLS. In this case, the AP can perform NPCA (infrastructure NPCA).

[0268] According to one embodiment of the present disclosure, each peer STA can maintain a list of OBSSs that can be detected (heard) by the AP. That is, the peer STA can determine whether an OBSS transmission can be detected (heard) by the AP based on the list of OBSSs that can be detected (heard) by the AP. If an OBSS corresponding to an OBSS transmission is not included in the list of OBSSs, it can be determined that the OBSS transmission cannot be detected by the AP. That is, if an OBSS corresponding to an OBSS transmission is not included in the list of OBSSs, the OBSS transmission can be determined as a first OBSS transmission. If an OBSS corresponding to an OBSS transmission is included in the list of OBSSs, it can be determined that the OBSS transmission can be detected by the AP. That is, if an OBSS corresponding to an OBSS transmission is included in the list of OBSS, the OBSS transmission can be determined as a second OBSS transmission.

[0269] According to one embodiment of the present disclosure, when the AP is an NPCA-disabled AP, NPCA-based channel switching may be enabled for any OBSS transmission, i.e., applicable to both the first OBSS transmission and the second OBSS transmission described above.

[0270] In the example of FIG. 18, the primary 20 MHz may be the base channel of STA1 and / or STA2. If the OBSS transmission detected on the primary 20 MHz is the first OBSS transmission, the AP may perform any operation including attempting to transmit to STA1 and / or STA2 on the primary 20 MHz. Upon detection of the OBSS transmission on the primary 20 MHz, STA1 and STA2 may move to the TDLS anchor channel through NPCA-based channel switching and perform P2P transmission through contention after a delay time due to NAV setting, channel switching, medium synchronization, etc.

[0271] When a peer STA is associated with an NPCA-enabled AP, information may be required to distinguish between a first OBSS transmission and a second OBSS transmission. That is, when a peer STA is associated with an NPCA-enabled AP, information may be required to distinguish between OBSSs.

[0272] According to one embodiment of the present disclosure, information about an OBSS detected (heard) by an AP can be provided. The information about the OBSS can correspond to a BSSID and / or a short BSSID. That is, an ID of an OBSS detected (heard) by the AP can be provided. The information about the OBSS can be conveyed via a Reduced Neighbor Report element. The information about the OBSS can be conveyed via a Reduced Neighbor Report element of a beacon frame and / or a probe response frame. The beacon frame and / or the probe response frame are exemplary and the present disclosure is not limited thereto.

[0273] According to one embodiment of the present disclosure, information about an OBSS detected (audible) by a peer STA may be provided. The peer STA may receive information about an OBSS detectable (audible) by another peer STA from another peer STA. This may be optional information, and thus, the peer STA may or may not receive information about an OBSS detectable (audible) by another peer STA from another peer STA.

[0274] For example, a peer STA may request information about an OBSS detected (or heard) from another peer STA, and the other peer STA may provide information about an OBSS detected (or heard) to the peer STA in response to the request. The information about the OBSS may be one or more of the following:

[0275] - Number of heard BSSID: The number of BSSIDs of detected (heard) OBSS

[0276] - List of heard BSSID: List of BSSIDs of detected (heard) OBSS

[0277] According to one embodiment of the present disclosure, a TDLS neighbor report request and a TDLS neighbor report response may be defined for such requests and responses. Through the TDLS neighbor report request, a peer STA may request information about an OBSS detected (heard) from another peer STA. Through the TDLS neighbor report response, another peer STA may provide information about an OBSS detected (heard) to the peer STA in response to the request.

[0278] For example, a TDLS neighbor report request and a TDLS neighbor report response can be distinguished by the value of the TDLS Action field. The TDLS Action field, which is the octet immediately following the Category field, distinguishes the Action field format, and the values ​​of the TDLS Action field associated with each Action field format within a TDLS category are exemplified in Table 2.

[0279] [Table 2]

[0280]

[0281] Referring to Table 2, values ​​11 to 255 of the TDLS Action field are reserved. According to one embodiment of the present disclosure, a TDLS neighbor report request and a TDLS neighbor report response can be distinguished based on the reserved values ​​of the TDLS Action field. For example, a specific value (e.g., 11) among the values ​​11 to 255 can indicate a TDLS neighbor report request, and another specific value (e.g., 12) among the values ​​11 to 255 can indicate a TDLS neighbor report response.

[0282] FIG. 19 is a diagram illustrating an example of an NPCA-based channel switching operation from a base channel according to one embodiment of the present disclosure. FIG. 19 illustrates an example of an NPCA-based channel switching operation by intra-BSS transmission.

[0283] According to one embodiment of the present disclosure, the NPCA-based channel switching operation may vary depending on the TXOP holder. The NPCA-based channel switching operation may vary depending on whether the TXOP holder is a non-AP STA (a STA that is not a peer STA, a non-P2P STA) or an AP.

[0284] According to one embodiment of the present disclosure, when a TXOP holder is an STA, a peer STA can perform an NPCA-based channel switching operation.

[0285] According to one embodiment of the present disclosure, when a TXOP holder is an AP, the AP may not perform DL transmission and / or may not trigger for UL PPDU while a peer STA (NPCA peer STA) is on an anchor channel. The AP may not perform DL transmission to the peer STA while the peer STA is on the anchor channel. The AP may not trigger for UL PPDU to the peer STA while the peer STA is on the anchor channel. That is, the AP may not perform DL transmission to the peer STA and / or UL PPDU trigger to the peer STA during the middle of TXOP. The peer STA may not expect DL transmission and / or UL PPDU trigger from the AP, which is the TXOP holder, while on the anchor channel.

[0286] According to one embodiment of the present disclosure, an AP may know information about peer STAs. The AP may have information about which STAs form a P2P pair. If the TXOP holder is an AP, the AP may not perform DL transmission for the peer STA while the peer STA is on the anchor channel, and / or may not perform UL PPDU triggering for the peer STA, based on the information.

[0287] Referring to the example of FIG. 19, STA2 and STA3 included in the BSS of the AP may have established a TDLS-based P2P link. The primary 20 MHz may be the base channel of STA2 and / or STA3. Here, the AP may perform frame exchange with STA1 included in the BSS on the primary 20 MHz. When transmission between STA1 and the AP (intra-BSS transmission) is detected on the primary 20 MHz, STA2 and STA3 may move to the TDLS anchor channel through NPCA-based channel switching, and perform P2P transmission through contention after a delay time according to NAV setting, channel switching, medium synchronization, etc. The AP may not perform DL transmission to STA2 and STA3 while STA2 and STA3 are on the anchor channel, and may not trigger UL PPDU. The AP can exchange frames with STA1 on the primary 20 MHz while STA2 and STA3 are on the anchor channel.

[0288] FIG. 20 is a diagram illustrating an example of NPCA-based channel switching according to one embodiment of the present disclosure.

[0289] FIG. 21 is a diagram illustrating an example of NPCA-based channel switching according to one embodiment of the present disclosure.

[0290] Figures 20 and 21 illustrate examples of conditions under which a peer STA can move to an anchor channel for NPCA-based channel switching. Figure 20 may be an example of a case where an ICF and / or an ICR are received / detected, and Figure 21 may be an example of a case where an ICF and an ICR are not received / detected.

[0291] Referring to FIG. 20, an ICF and / or ICR, a data frame, and an IR can be transmitted in a primary 20 MHz channel. If the condition described below for a peer STA receiving an ICF and / or an ICR is satisfied, the peer STA can perform transmission by moving to a TDLS anchor channel through NPCA-based channel switching. The peer STA can perform transmission within an NPCA-based channel switching enabled duration. The ICF can be a frame for acquiring a TXOP, and the ICR can be understood as a response to the ICF. For example, examples of the ICF can include an RTS, a trigger frame, etc., and examples of the ICR can include a CTS, etc.

[0292] Referring to FIG. 21, a data frame and an IR can be transmitted on a primary 20 MHz channel. If an ICF and an ICR are not received and the RA is a data frame indicating peer STA1, peer STA 1 can receive the data frame. Peer STA 1 can transmit an IR for the data frame. If the condition for when the peer STA does not receive an ICF and an ICR, which will be described later, is satisfied (for example, if the data frame is determined not to be for the peer STA based on the STA_ID, Group ID, and Partial AID identified from the PHY header of the data frame), the peer STA can perform transmission by moving to a TDLS anchor channel through NPCA-based channel switching. The peer STA can perform transmission within an NPCA-based channel switching enabled duration.

[0293] According to one embodiment of the present disclosure, when a peer STA receives an ICF and / or an ICR, the peer STA may move to an anchor channel if one (or more) of the conditions is satisfied. The peer STA may operate on the anchor channel until the end of the TXOP. The conditions may be predefined and may include at least one of the following. Among the following conditions, (1) and (2) may be for intra-BSS cases, and (3) may be for intra-BSS cases and / or OBSS cases.

[0294] (1) If the TA (transmitting address) included in the received ICF is the same as the MAC address of the associated AP (the entity that transmitted the ICF received by the STA is the AP associated with the STA):

[0295] - 1) If the RA (receiving address) included in the received ICF is different from the broadcast address, and the RA included in the received ICF is different from the MAC address of any peer STA; or

[0296] - 2) If the RA included in the received ICF is the same as the broadcast address and the AID subfields in the User Info field included in the received ICF do not indicate any peer STAs (no AID subfields in User Info fields indicate peer STAs):

[0297] - - If a PHY-RXSTART.indication primitive is received after an ICF (for example, if a PHY-RXSTART.indication primitive is received in a CTS (ICR))

[0298] (2) If the TA included in the received ICF is different from the MAC address of the associated AP and / or peer STA:

[0299] - If a PHY-RXSTART.indication primitive is received after an ICF (for example, if a PHY-RXSTART.indication primitive is received in a CTS (ICR))

[0300] (3) When the RA included in the received ICR is different from the MAC address of the associated AP and / or peer STA. In the case where the ICF is not received and the ICR is received, when the RA included in the ICR received by the STA is different from the MAC address of the AP associated with the STA and / or the MAC address of the peer STA. In this case, the ICR may be, but is not limited to, an OBSS ICR.

[0301] According to one embodiment of the present disclosure, if a peer STA fails to receive / detect an ICF and an ICR, the peer STA may move to an anchor channel if one (or more) of the conditions is satisfied.

[0302] Conditions may be predefined and may include at least one of the following. The following conditions may be for intra-BSS cases.

[0303] (1) For HE (high efficiency), EHT, and / or UHR PPDUs, if the STA_ID in the User Specific field in the SIG does not indicate any peer STA (either one of the two STAs forming the P2P pair), the peer STA may move to the anchor channel. The peer STA may operate on the anchor channel until the end of the TXOP, which may be indicated in the SIG.

[0304] (2) In case of VHT MU PPDU, Group ID and NSTS are checked, and if any peer STA (either one of the two STAs forming the P2P pair) is not indicated by Group ID and NSTS, the peer STA may receive the entire PPDU to obtain TXOP and / or move to the anchor channel until the end of the PPDU (operate on the anchor channel until the end of the PPDU).

[0305] (3) In case of VHT SU PPDU, Partial AID is checked, and if any peer STA (either one of the two STAs forming the P2P pair) is not indicated by Partial AID, the peer STA may receive the entire PPDU to obtain TXOP and / or move to the anchor channel until the end of the PPDU (operate on the anchor channel until the end of the PPDU).

[0306] (4) For HT and / or non-HT PPDU (or for control frame), the entire PPDU is received and the RA is checked. If the RA does not match any peer STA (either one of the two STAs forming the P2P pair) (if the RA does not indicate any peer STA), the peer STA can move to the anchor channel. The peer STA can operate on the anchor channel until the end of the TXOP.

[0307] An NPCA-based channel switching from an off-channel according to one embodiment of the present disclosure is described. The information required to activate NPCA-based channel switching from an off-channel may be as follows. At least some of the information below may be required.

[0308] - Anchor channel for TDLS (anchor channel for off-channel TDLS. TDLS anchor channel). It may be a TDLS anchor channel corresponding to an off-channel. Unless specifically stated otherwise, the anchor channel and TDLS anchor channel may be used interchangeably in the description of an embodiment of the present disclosure.

[0309] - Channel width and / or center frequency of TDLS NPCH: Information about TDLS NPCH (off-channel TDLS NPCH) including TDLS anchor channel (anchor channel for off-channel TDLS).

[0310] According to one embodiment of the present disclosure, the information necessary to activate NPCA-based switching from the above-described off-channel may be exchanged during the TDLS channel switching process. In this case, referring back to FIG. 9, it can be understood that at 990, STA1 and STA2 switch to the target channel (off-channel) and then, if the switched off-channel is busy, switch to the TDLS anchor channel, and the necessary information may be used in the corresponding operation.

[0311] According to one embodiment of the present disclosure, the TDLS channel switch request frame and / or the TDLS channel switch response frame may include at least some of the following information. That is, according to one embodiment of the present disclosure, at least some of the following elements may be added to the TDLS channel switch request frame and / or the TDLS channel switch response frame. The following information / elements may correspond to information required to activate NPCA-based channel switching from the above-described off-channel. The names of the frames are examples, and the present disclosure is not limited thereto.

[0312] - TDLS anchor channel: 1 octet. The Target Channel field can be reused. It can indicate a TDLS anchor channel for off-channels.

[0313] - Channel band and / or channel frequency of TDLS NPCH

[0314] - - Bandwidth Indication element can be reused.

[0315] - - - Control: Can indicate channel bandwidth.

[0316] - - - CCFS0: May represent the center frequency of a 20, 40 and / or 80 MHz channel and / or a P80 (primary 80 MHz) channel of a 160 MHz channel and / or a P160 (primary 160 MHz) channel of a 320 MHz channel.

[0317] - - - CCFS1: Can indicate the center frequency of a 160 MHz channel and / or the center frequency of a 320 MHz channel.

[0318] For example, information about a TDLS anchor channel may be included in a TDLS channel switch request frame, or may be included in a TDLS channel switch request frame and a TDLS channel switch response frame. If a TDLS anchor channel is included in a TDLS channel switch request frame and a TDLS channel switch response frame, it may be for negotiating an anchor channel between two STAs. The above-described example is one example and the present disclosure is not limited thereto.

[0319] Referring back to FIG. 17A, the Target Channel field format is illustrated. The Target Channel field may specify the channel number of the target channel and may consist of 1 octet. According to one embodiment of the present disclosure, a TDLS anchor channel (a TDLS anchor channel for an off-channel) may be indicated by the Target Channel field.

[0320] Referring back to FIG. 17b, the Bandwidth Indication element format is exemplified in (a) of FIG. 17b. The Bandwidth Indication element may include an Element ID field (1 octet), a Length field (1 octet), a Bandwidth Indication Parameters field (1 octet), and a Bandwidth Indication Information field (3 or 5 octets).

[0321] According to one embodiment of the present disclosure, Bandwidth Indication Information may be used to indicate a channel band and / or channel frequency of a TDLS NPCH (TDLS anchor channel for off-channel). The definition of Bandwidth Indication Information may be the same as the definition of the EHT Operation Information field of the EHT Operation element. The format of the EHT Operation Information field is illustrated in (b) of FIG. 17B. The EHT Operation Information field may include a Control subfield (1 octet), a CCFS0 subfield (1 octet), a CCFS1 subfield (1 octet), and a Disabled Subchannel Bitmap subfield (0 or 2 octets). The Control subfield may include a Channel Width subfield (3 bits, B0 to B2), and a Reserved subfield (5 bits, B3 to B7).

[0322] The definitions of the Channel Width subfield, CCFS0 subfield, and CCFS1 subfield of the EHT Operation Information field can be referred back to Table 1, and according to one embodiment of the present disclosure, the Control subfield (within the Channel Width subfield), CCFS0, and CCFS1 can be used to indicate the channel band and / or channel frequency of the TDLS NPCH (TDLS NPCH for off-channel).

[0323] According to one embodiment of the present disclosure, the Channel Width subfield within the Control subfield may define a channel band of a TDLS NPCH. It may be set to 0 for a 20 MHz channel band; 1 for a 40 MHz channel band; 2 for an 80 MHz channel band; 3 for a 160 MHz channel band; and 4 for a 320 MHz channel band. The values ​​5 to 7 may be reserved. The channel bands corresponding to the values ​​of the Channel Width subfield are merely examples, and the present disclosure is not limited thereto. For example, the corresponding values ​​and the channel bands may be changed, and at least some of the reserved values ​​5 to 7 may be used to indicate the channel band. In addition, the use of the Channel Width subfield is merely an example, and the present disclosure is not limited thereto. For example, reserved subfields within the Control subfield may also be used.

[0324] According to one embodiment of the present disclosure, CCFS0 and CCFS1 may represent the center frequency and / or primary channel of the TDLS NPCH. The values ​​of each subfield below and the corresponding channel bands are examples, and the present disclosure is not limited thereto.

[0325] For example, when the TDLS NPCH channel band is 20, 40, or 80 MHz, CCFS0 may represent a channel center frequency index of the 20, 40, or 80 MHz TDLS NPCH channel band. For example, when the TDLS NPCH channel band is 160 MHz, CCFS0 may represent a primary 80 MHz channel center frequency index of the 160 MHz TDLS NPCH channel band. For example, when the TDLS NPCH channel band is 320 MHz, CCFS0 may represent a primary 160 MHz channel center frequency index of the 320 MHz TDLS NPCH channel band.

[0326] For example, if the TDLS NPCH channel band is 20, 40, or 80 MHz, CCFS1 may be set to 0. For example, if the TDLS NPCH channel band is 160 MHz, CCFS1 may indicate the channel center frequency index of the 160 MHz TDLS NPCH channel band. For example, if the TDLS NPCH channel band is 320 MHz, CCFS1 may indicate the channel center frequency index of the 320 MHz TDLS NPCH channel band.

[0327] FIG. 22 is a diagram illustrating an example of NPCA-based channel switching according to one embodiment of the present disclosure. FIG. 22 illustrates an example of NPCA-based channel switching from an off-channel.

[0328] According to one embodiment of the present disclosure, a peer STA may be in PS mode (or doze state) from the AP perspective. The AP may not transmit on the primary 20 MHz channel to the peer STA. The peer STA may perform NPCA-based channel switching when it detects an OBSS transmission and / or an intra-BSS transmission on a TDLS off-channel. The peer STA may perform NPCA-based channel switching when it receives / detects any PPDU from an OBSS on a TDLS off-channel. The peer STA may perform NPCA-based channel switching regardless of whether the AP has NPCA enabled or disabled. For example, the peer STA may assume that the AP has NPCA disabled.

[0329] According to one embodiment of the present disclosure, the TDLS neighbor report request and TDLS neighbor report response described in NPCA-based channel switching from a base channel can also be used in NPCA-based channel switching from an off-channel. This may be optional information. The TDLS neighbor report request and TDLS neighbor report response transmitted and received in the off-channel may include neighbor information in the off-channel. For example, the number of BSSIDs of OBSSs detected (heard) in the off-channel (Number of heard BSSIDs) and / or the list of BSSIDs of OBSSs detected (heard) in the off-channel (List of heard BSSIDs) may be included. For more details, refer to the description of the TDLS neighbor report request and TDLS neighbor report response described in NPCA-based channel switching from a base channel.

[0330] Fig. 23 illustrates an example of an operation of an STA according to an embodiment of the present disclosure. Fig. 23 may be understood as an example of an operation of peer STAs constituting a P2P pair. In Fig. 23, the operation of an STA (peer STA) may be understood as an operation of at least one of the peer STAs constituting the P2P pair. In Fig. 23, checking a specific state of an STA (peer STA) may be understood as determining a specific state of at least one of the peer STAs constituting the P2P pair.

[0331] The flowchart of FIG. 23 illustrates an exemplary method that may be implemented according to the principles of the present disclosure, and various modifications may be made to the method depicted in the flowchart. For example, although depicted as a series of steps, the various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.

[0332] Referring to FIG. 23, a peer STA is capable of NPCA-based channel switching, and the channel may be in a busy state (2301).

[0333] According to one embodiment of the present disclosure, it can be determined whether a peer STA is operating on a base channel (2303). That is, it can be determined whether a non-active channel is a base channel.

[0334] According to one embodiment of the present disclosure, if it is determined at 2303 that the peer STA is operating on the base channel, it may be determined whether the channel is busy due to OBSS transmission (2305).

[0335] According to one embodiment of the present disclosure, if the channel is determined to be busy due to OBSS transmission in 2305, it may be determined whether the AP has NPCA enabled (2307). Whether the AP has NPCA enabled may include whether the AP has capability for NPCA. For example, capability information related to NPCA of the AP may be conveyed through UHR capability, and may be conveyed according to an association procedure with the AP and / or a probe request / response frame transmission / reception procedure and / or transmission / reception of other UHR capabilities. For example, if the AP has the capability for NPCA, activation / deactivation of NPCA may be conveyed based on a beacon frame and / or a separately defined frame.

[0336] According to one embodiment of the present disclosure, if the AP determines that NPCA is enabled at 2307, it may be determined whether the AP can detect (hear) an OBSS transmission (2313). For example, the determination may be based on a list of OBSSs that can be detected (heard) by the AP.

[0337] According to one embodiment of the present disclosure, if it is determined that the AP can detect an OBSS transmission at 2309, NPCA-based channel switching may be deferred (2313). Deferring NPCA-based channel switching may include not performing NPCA-based channel switching.

[0338] According to one embodiment of the present disclosure, if the AP determines that NPCA is disabled at 2307, NPCA-based channel switching may be activated. Depending on the NPCA-based channel switching, transmission and reception may be performed on the anchor channel and / or NPCH until the end of the TXOP (or PPDU. This may vary depending on, for example, whether NPCA is TXOP-based or PPDU-based, but the present disclosure is not limited thereto) (2315).

[0339] According to one embodiment of the present disclosure, if it is determined that the AP cannot detect an OBSS transmission at 2309, NPCA-based channel switching may be activated. According to the NPCA-based channel switching, transmission and reception may be performed on the anchor channel and / or NPCH until the end of the TXOP (or PPDU. This may vary depending on, for example, whether the NPCA is TXOP-based or PPDU-based, but the present disclosure is not limited thereto) (2315).

[0340] According to one embodiment of the present disclosure, when it is determined at 2303 that the peer STA is not operating on the base channel, i.e., when it is determined that the peer STA is operating on an off channel, NPCA-based channel switching may be activated. According to the NPCA-based channel switching, transmission and reception may be performed on the anchor channel and / or NPCH until the end of the TXOP (or PPDU. This may vary depending on, for example, whether the NPCA is TXOP-based or PPDU-based, but the present disclosure is not limited thereto) (2315).

[0341] According to one embodiment of the present disclosure, if it is determined at 2305 that the channel is not busy due to OBSS transmission, i.e., if it is determined that the channel is busy due to intra BSS transmission, it may be determined whether the AP can trigger DL transmission and / or UL transmission to the peer STA (2311). For example, if the TXOP holder is an STA, the peer STA may perform NPCA-based channel switching operation. For example, if the TXOP holder is an AP, the AP may not perform DL transmission and / or may not trigger for UL PPDU while the peer STA (NPCA peer STA) is on the anchor channel.

[0342] According to one embodiment of the present disclosure, if it is determined that the AP can trigger DL transmission and / or UL transmission to the peer STA at 2305, NPCA-based channel switching may be deferred (2313). Deferring NPCA-based channel switching may include not performing NPCA-based channel switching.

[0343] According to one embodiment of the present disclosure, if it is determined that the AP cannot trigger DL transmission and / or UL transmission to the peer STA at 2305, NPCA-based channel switching may be activated. According to the NPCA-based channel switching, transmission and reception may be performed on the anchor channel and / or NPCH until the end of the TXOP (or PPDU. This may vary depending on, for example, whether the NPCA is TXOP-based or PPDU-based, but the present disclosure is not limited thereto) (2315).

[0344] For more specific details on the operation of the STA according to one embodiment of the present disclosure described above, reference may be made to the description of various embodiments of the present disclosure described above.

[0345] Fig. 24 illustrates an example of the operation of an STA according to one embodiment of the present disclosure. Fig. 24 may be understood as the operation of a first STA among the first STA and the second STA, which are peer STAs forming a P2P pair.

[0346] The flowchart of FIG. 24 illustrates an exemplary method that may be implemented according to the principles of the present disclosure, and various modifications may be made to the method depicted in the flowchart. For example, although depicted as a series of steps, the various steps in each drawing may overlap, occur in parallel, occur in different orders, or occur multiple times. In other examples, steps may be omitted or replaced with other steps.

[0347] Referring to FIG. 24, according to one embodiment of the present disclosure, a first STA may identify that a first channel for a direct-link with a second STA is busy (2410). The direct-link may correspond to TDLS, and the first channel may be a base channel or an off-channel.

[0348] According to one embodiment of the present disclosure, a first STA can identify a second channel corresponding to a first channel (2420). The second channel can be an anchor channel for performing channel access according to NPCA in NPCA-based channel switching. Since the anchor channel for the base channel and the anchor channel for the off channel can be set differently, the second channel can be identified to correspond to the first channel (or based on the first channel).

[0349] According to one embodiment of the present disclosure, a first STA may obtain a transmission opportunity (TXOP) for a non-primary channel (NPCH) including a second channel based on a channel access procedure in the second channel (2430).

[0350] According to one embodiment of the present disclosure, a first STA may communicate with a second STA through the direct connection on an NPCH based on a TXOP (2440). This may be communication performed between the first STA and the second STA on the switched channel after channel switching.

[0351] For more specific details on the operation of the STA according to one embodiment of the present disclosure described above, reference may be made to the description of various embodiments of the present disclosure described above.

[0352] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0353] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to embodiments described in the claims or specification of the present disclosure.

[0354] These programs (software modules, software) may be stored in random access memory, non-volatile memory including flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage device, compact disc ROM (CD-ROM), digital versatile discs (DVDs) or other forms of optical storage device, magnetic cassette. Or, they may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0355] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network, such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device implementing an embodiment of the present disclosure.

[0356] In the specific embodiments of the present disclosure described above, components included in one embodiment are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0357] Meanwhile, the embodiments of the present disclosure disclosed in this specification and drawings are merely specific examples to easily explain the technical content of the present disclosure and facilitate understanding of the present disclosure, and are not intended to limit the scope of the present disclosure. In other words, it will be apparent to those skilled in the art to which the present disclosure pertains that other modifications based on the technical concept of the present disclosure are possible. Furthermore, each of the above embodiments can be combined and operated as needed.

[0358] Meanwhile, the order of description in the drawings explaining the method of the present disclosure does not necessarily correspond to the order of execution, and the order of precedence may be changed or executed in parallel.

[0359] Alternatively, the drawings illustrating the method of the present disclosure may omit some components and include only some components without detracting from the essence of the present disclosure.

[0360] In addition, the method of the present disclosure may be implemented by combining some or all of the contents included in each embodiment within a scope that does not harm the essence of the present disclosure.

[0361] Various embodiments of the present disclosure have been described above. The foregoing description of the present disclosure is for illustrative purposes only, and the embodiments of the present disclosure are not limited to the disclosed embodiments. Those skilled in the art will appreciate that the present disclosure can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present disclosure. The scope of the present disclosure is indicated by the claims described below rather than the detailed description above, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included within the scope of the present disclosure.

Claims

1. In a method performed by a first STA (station) in a wireless LAN (local access network) system, A step of identifying to perform an operation related to channel switching based on identifying that a first channel for a direct-link with a second STA is busy; and comprising a step of performing an operation related to the above channel switching, The steps for performing the above channel switching related operations are: A step of identifying a second channel corresponding to the first channel; A step of acquiring a transmission opportunity (TXOP) for a non-primary channel (NPCH) including the second channel based on a channel access procedure in the second channel; and A method comprising a step of communicating with the second STA through the direct connection on the NPCH based on the TXOP.

2. In paragraph 1, The first channel is identified as busy as a transmission related to an overlapping basic service set (OBSS) is identified on the first channel, It is identified that the first STA will perform an operation related to the channel switching based on the identification that the non-primary channel access (NPCA) is disabled in the associated AP (access point), A method in which the first STA is identified as having NPCA (non-primary channel access) enabled in an associated AP (access point), and is identified to perform an operation related to the channel switching based on the identifier of one or more basic service sets (BSSs) received from the AP not including an identifier of the OBSS.

3. In paragraph 1, The first channel is identified as busy as a transmission related to intra-BSS is identified in the first channel, The TA (transmitting address) of the ICF (initial control frame) received by the first STA on the first channel indicates the MAC (medium access control) address of the AP associated with the first STA: The RA (receiving address) of the ICF does not indicate a broadcast address, and the RA of the ICF does not indicate the MAC address of the first STA and the MAC address of the second STA; or The RA of the ICF indicates the broadcast address, and the AID (association identifier) ​​subfield of the User Info field does not indicate the first STA and the second STA: A method in which an operation related to channel switching is identified to be performed based on identification that the first channel is busy after receiving the ICF.

4. In paragraph 1, The first channel is identified as busy as a transmission related to the intra-BSS is identified on the first channel, The TA of the ICF received by the first STA on the first channel does not indicate the MAC address of the AP associated with the first STA, the MAC address of the first STA, and the MAC address of the second STA: A method in which an operation related to channel switching is identified to be performed based on receiving an ICR (initial control response) from the first channel after receiving the ICF.

5. In paragraph 1, A method in which the first STA is identified to perform an operation related to the channel switching based on the fact that the RA of the ICR received on the first channel does not indicate the MAC address of the AP associated with the first STA, the MAC address of the first STA, and the MAC address of the second STA.

6. In paragraph 1, The first channel is identified as busy as a transmission related to the intra-BSS is identified on the first channel, It is identified that the first STA will perform an operation related to the channel switching based on the STA_ID in the user specific field in the SIG (signal) of the HE (high efficiency) PPDU (physical layer protocol data unit), EHT (extremely high throughput) PPDU or UHR (ultra high reliability) PPDU received on the first channel not indicating the first STA and the second STA, It is identified that the first STA will perform an operation related to the channel switching based on the group ID and number of space-time streams (NSTS) of the very high throughput (VHT) MU (multi user) PPDU received on the first channel not indicating the first STA and the second STA, It is identified that the first STA will perform an operation related to the channel switching based on the fact that the first STA does not indicate the first STA and the second STA according to the PAID (partial AID) of the VHT SU (single user) PPDU received on the first channel, A method in which the first STA is identified to perform an operation related to the channel switching based on the fact that the RA of the HT (high throughput) PPDU, non-HT PPDU or control frame received on the first channel does not indicate the first STA and the second STA.

7. In paragraph 1, The above direct connection corresponds to a tunneled direct-link setup (TDLS) between the first STA and the second STA, The above first channel is a base channel associated with the TDLS, The above channel access procedure is for NPCA-based channel switching from the base channel, One or more elements related to NPCA-based channel switching from the base channel are exchanged between the first STA and the second STA in a setup procedure related to the TDLS, The one or more elements include at least one of an element for capability related to NPCA-based channel switching, an element for the second channel for the base channel, an element for a channel bandwidth of the NPCH, an element for a center frequency of the NPCH, an element for a channel switch time related to NPCA-based channel switching from the base channel, or an element related to a user position array field. The element for the capability related to the above NPCA-based channel switching corresponds to 1 bit within the UHR capability, The element for the second channel for the base channel corresponds to a target channel field of 1 octet, The element for the channel bandwidth of the above NPCH corresponds to a control subfield of 1 octet of the bandwidth indication information of the bandwidth indication element, A method in which an element for the center frequency of the above NPCH corresponds to at least one of the CCFS (channel center frequency segment) 0 subfield or CCFS1 subfield of the above bandwidth indication information.

8. In paragraph 1, The above direct connection corresponds to the TDLS between the first STA and the second STA, The above first channel is an off channel related to the TDLS, The above channel access procedure is for NPCA-based channel switching from the off-channel, One or more elements related to NPCA-based channel switching from the base channel are exchanged between the first STA and the second STA in a channel switching procedure related to the TDLS, The one or more elements include at least one of the second channel for the off-channel, the channel bandwidth of the NPCH, and the center frequency of the NPCH, The element for the second channel for the above off-channel corresponds to a target channel field of 1 octet, The element for the channel bandwidth of the above NPCH corresponds to a control subfield of 1 octet of the bandwidth indication information of the bandwidth indication element, A method in which an element for the center frequency of the above NPCH corresponds to at least one of the CCFS0 subfield or the CCFS1 subfield of the above bandwidth indication information.

9. In the first STA (station) of a wireless LAN (local access network) system, Transmitter and receiver; and A processor connected to the transceiver, the processor comprising: Identifying that an action related to channel switching is to be performed based on identifying that a first channel for a direct-link with a second STA is busy; and is set to perform an operation related to the above channel switching, In performing the above channel switching related operations, the processor: Identify a second channel corresponding to the first channel; Acquiring a transmission opportunity (TXOP) for a non-primary channel (NPCH) including the second channel based on a channel access procedure in the second channel; and A first STA configured to communicate with the second STA through the direct connection on the NPCH based on the TXOP.

10. In paragraph 9, The first channel is identified as busy as a transmission related to an overlapping basic service set (OBSS) is identified on the first channel, The second channel is identified based on the first STA being identified as having non-primary channel access (NPCA) disabled in the associated AP (access point), A first STA, which is identified as having NPCA (non-primary channel access) enabled in an associated AP (access point) and is identified to perform an operation related to the channel switching based on the identifier of one or more basic service sets (BSSs) received from the AP not including an identifier of the OBSS.

11. In paragraph 9, The first channel is identified as busy as a transmission related to intra-BSS is identified in the first channel, The TA (transmitting address) of the ICF (initial control frame) received by the first STA on the first channel indicates the MAC (medium access control) address of the AP associated with the first STA: The RA (receiving address) of the ICF does not indicate a broadcast address, and the RA of the ICF does not indicate the MAC address of the first STA and the MAC address of the second STA; or The RA of the ICF indicates the broadcast address, and the AID (association identifier) ​​subfield of the User Info field does not indicate the first STA and the second STA: A first STA that is identified to perform an operation related to the channel switching based on receiving an ICR (initial control response) on the first channel after receiving the ICF.

12. In paragraph 9, The first channel is identified as busy as a transmission related to the intra-BSS is identified on the first channel, The TA of the ICF received by the first STA on the first channel does not indicate the MAC address of the AP associated with the first STA, the MAC address of the first STA, and the MAC address of the second STA: A first STA that is identified to perform an operation related to the channel switching based on receiving an ICR (initial control response) on the first channel after receiving the ICF.

13. In paragraph 9, A first STA, which is identified to perform an operation related to the channel switching, based on the fact that the RA of the ICR received by the first STA on the first channel does not indicate the MAC address of the AP associated with the first STA, the MAC address of the first STA, and the MAC address of the second STA.

14. In paragraph 9, The first channel is identified as busy as a transmission related to the intra-BSS is identified on the first channel, It is identified that the first STA will perform an operation related to the channel switching based on the STA_ID in the user specific field in the SIG (signal) of the HE (high efficiency) PPDU (physical layer protocol data unit), EHT (extremely high throughput) PPDU or UHR (ultra high reliability) PPDU received on the first channel not indicating the first STA and the second STA, It is identified that the first STA will perform an operation related to the channel switching based on the group ID and number of space-time streams (NSTS) of the very high throughput (VHT) MU (multi user) PPDU received on the first channel not indicating the first STA and the second STA, It is identified that the first STA will perform an operation related to the channel switching based on the fact that the first STA does not indicate the first STA and the second STA according to the PAID (partial AID) of the VHT SU (single user) PPDU received on the first channel, A first STA, which is identified to perform an operation related to the channel switching based on the fact that the RA of the HT (high throughput) PPDU, non-HT PPDU or control frame received by the first STA on the first channel does not indicate the first STA and the second STA.

15. In paragraph 9, The above direct connection corresponds to a tunneled direct-link setup (TDLS) between the first STA and the second STA, The above first channel is a base channel associated with the TDLS, The above channel access procedure is for NPCA-based channel switching from the base channel, One or more elements related to NPCA-based channel switching from the base channel are exchanged between the first STA and the second STA in a setup procedure related to the TDLS, A first STA, wherein the one or more elements include at least one of an element for capability related to NPCA-based channel switching, an element for the second channel for the base channel, an element for a channel bandwidth of the NPCH, an element for a center frequency of the NPCH, an element for a channel switch time related to NPCA-based channel switching from the base channel, or an element related to a user position array field.

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