Method and apparatus for transmitting and receiving inheritance-based information in wireless LAN system

Abstract

A method and apparatus for transmitting and receiving inheritance-based information in a wireless LAN system are disclosed. According to one embodiment of the present disclosure, a method performed by means of a station (STA) in a wireless LAN system comprises the steps of: transmitting, to a first access point (AP), a request frame including information related to a second AP and / or a first multilink device (MLD); and receiving a response frame to the request frame from the first AP, where the response frame includes one or more per-STA profiles, and the inheritance or non-inheritance for the one or more per-STA profiles can be based on an untransmitted (non-Tx) basic service set identifier (BSSID) profile.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for transmitting or receiving inheritance-based information in a (Wireless Local Area Network) WLAN system. Background Art

[0002] New technologies have been introduced for wireless LAN (WLAN) to improve transmission rates, increase bandwidth, improve reliability, reduce errors, and reduce latency. Among WLAN technologies, the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series of standards may be referred to as Wi-Fi. For example, technologies recently introduced to WLAN include enhancements to the Very High Throughput (VHT) standard of the 802.11ac standard and enhancements to High Efficiency (HE) of the IEEE 802.11ax standard.

[0003] In order to provide a more complete wireless communication environment, enhanced technologies for EHT (Extremely High Throughput) are being discussed. For example, technologies for supporting increased bandwidth, effective use of multiple bands, and increased spatial streams, multi-access point (AP) coordination and multiple-input multiple-output (MIMO) are being studied, and in particular, various technologies for supporting low-latency or real-time services are being studied. In addition, new technologies that support ultra-high reliability (UHR) by including improvements or extensions of EHT technology are being discussed. Summary of the invention

[0004] Technical issues

[0005] The technical problem of the present disclosure is to provide a method and device for transmitting or receiving inheritance-based information in a WLAN system.

[0006] An additional technical problem of the present disclosure is to provide a method and apparatus for determining an inherited reference based on a multi-link device (MLD) and multiple basic service set identifiers (BSSIDs) in a WLAN system.

[0007] The technical objectives achieved by the present disclosure are not limited to the above-mentioned technical objectives, and other technical objectives not described herein will be clearly understood by those skilled in the relevant art from the following description.

[0008] Technical Solution

[0009] A method performed by a station (STA) in a WLAN system according to one aspect of the present disclosure includes: sending a request frame to a first access point (AP), the request frame including information related to at least one of a second access point (AP) or a first multi-link device (MLD); and receiving a response frame to the request frame from the first AP, wherein the response frame may include at least one per-STA profile, and inheritance or non-inheritance for the at least one per-STA profile may be based on a profile of a non-transmit (non-Tx) basic service set identifier (BSSID).

[0010] According to another aspect of the present disclosure, a method performed by a first access point (AP) in a WLAN system includes: receiving a request frame from a station (STA), the request frame including information related to at least one of a second access point (AP) or a first multi-link device (MLD); and sending a response frame to the request frame to the STA, wherein the response frame may include at least one per-STA profile, and inheritance or non-inheritance for the at least one per-STA profile may be based on a profile of a non-transmit (non-Tx) basic service set identifier (BSSID).

[0011] Beneficial Effects

[0012] According to the present disclosure, a method and apparatus for transmitting or receiving inheritance-based information in a WLAN system may be provided.

[0013] According to the present disclosure, a method and apparatus for determining an inherited reference based on a multi-link device (MLD) and multiple basic service set identifiers (BSSIDs) in a WLAN system may be provided.

[0014] Effects achievable by the present disclosure are not limited to the above-described effects, and other effects not described herein may be clearly understood by those skilled in the art through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are included as a part of the detailed description for understanding the present disclosure, provide embodiments of the present disclosure and describe technical features of the present disclosure through the detailed description.

[0016] Figure 1 A block configuration diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0017] Figure 2 is a diagram illustrating an exemplary structure of a WLAN system to which the present disclosure can be applied.

[0018] Figure 3 is a diagram for describing a link setting process to which the present disclosure can be applied.

[0019] Figure 4is a diagram for describing a backoff process to which the present disclosure can be applied.

[0020] Figure 5 is a diagram for describing a CSMA / CA-based frame transmission operation to which the present disclosure may be applied.

[0021] Figure 6 is a diagram for describing an example of a frame structure used in a WLAN system to which the present disclosure can be applied.

[0022] Figure 7 is a diagram illustrating an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0023] Figure 8 The structure of the ML element to which the present disclosure can be applied is exemplarily shown.

[0024] Fig. 9 is a diagram showing an exemplary relationship between a multi-BSSID set and a multi-link device to which the present disclosure may be applied.

[0025] Fig.10 is a diagram for describing an example of an ML element to which an MBSSID element of the present disclosure can be applied.

[0026] Fig.11 is a diagram for describing an example of a method for a STA to obtain information related to a plurality of APs according to the present disclosure.

[0027] Fig.12 is a diagram for describing an example of a method for an AP to provide information about a plurality of APs to a STA according to the present disclosure.

[0028] Fig.13 An example of inheritance / non-inheritance application based on a non-Tx BSSID profile according to the present disclosure is shown. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description to be disclosed by the accompanying drawings is intended to describe exemplary embodiments of the present disclosure, rather than to represent the only embodiment in which the present disclosure can be implemented. The following detailed description includes specific details to provide a complete understanding of the present disclosure. However, those skilled in the relevant art will appreciate that the present disclosure can be implemented without these specific details.

[0030] In some cases, well-known structures and devices may be omitted, or may be shown in the form of a block diagram based on the core functions of each structure and device in order to prevent ambiguity in the concepts of the present disclosure.

[0031] In the present disclosure, when an element is referred to as being "connected", "combined" or "linked" to another element, it may include an indirect connection relationship between another element and a direct connection relationship. In addition, in the present disclosure, the term "comprising" or "having" specifies the presence of the mentioned features, steps, operations, components and / or elements, but does not exclude the presence or addition of one or more other features, stages, operations, components, elements and / or groups thereof.

[0032] In the present invention, terms such as "first", "second", etc. are only used to distinguish one element from another element and are not used to limit the elements, and unless otherwise specified, they do not limit the order or importance between the elements. Therefore, within the scope of the present disclosure, the first element in an embodiment may be referred to as the second element in another embodiment, and similarly, the second element in an embodiment may be referred to as the first element in another embodiment.

[0033] The terms used in this disclosure are intended to describe specific embodiments rather than to limit the claims. As used in the description of the embodiments and the appended claims, the singular form is intended to include the plural form unless the context clearly indicates otherwise. The term "and / or" used in this disclosure may refer to one of the related enumerated items, or mean that it refers to and includes any and all possible combinations of two or more of them. In addition, unless otherwise stated, the " / " between words in this disclosure has the same meaning as "and / or".

[0034] Examples of the present disclosure may be applied to various wireless communication systems. For example, examples of the present disclosure may be applied to wireless LAN systems. For example, examples of the present disclosure may be applied to wireless LANs based on IEEE 802.11a / g / n / ac / ax standards. In addition, examples of the present disclosure may be applied to wireless LANs based on the newly proposed IEEE 802.11be (or EHT) standard. Examples of the present disclosure may be applied to wireless LANs based on the IEEE 802.11be version-2 standard corresponding to the additional enhanced technology of the IEEE 802.11be version-1 standard. In addition, examples of the present disclosure may be applied to next-generation standard-based wireless LANs after IEEE802.11be. In addition, examples of the present disclosure may be applied to cellular wireless communication systems. For example, it may be applied to cellular wireless communication systems based on technologies based on long term evolution (LTE) and technologies based on 5G new radio (NR) based on the third generation partnership project (3GPP) standard.

[0035] Hereinafter, technical features of examples to which the present disclosure can be applied will be described.

[0036] Figure 1 A block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0037] Figure 1 The first device 100 and the second device 200 illustrated in the figure may be replaced by various terms, such as terminal, wireless device, wireless transmit / receive unit (WTRU), user equipment (UE), mobile station (MS), user terminal (UT), mobile subscriber station (MSS), mobile subscriber unit (MSU), subscriber station (SS), advanced mobile station (AMS), wireless terminal (WT) or simple user, etc. In addition, the first device 100 and the second device 200 may include an access point (AP), a base station (BS), a fixed station, a node B, a base transceiver system (BTS), a network. It may be replaced by various terms such as an artificial intelligence (AI) system, a road side unit (RSU), a repeater, a router, a repeater and a gateway.

[0038] Figure 1 The devices 100 and 200 illustrated in FIG. 1 may be referred to as stations (STAs). For example, Figure 1 The devices 100 and 200 illustrated in the figure may be referred to by various terms such as a transmitting device, a receiving device, a transmitting STA, and a receiving STA. For example, STA110 and 200 may perform an access point (AP) role or a non-AP role. That is, in the present disclosure, STA 110 and 200 may perform the functions of an AP and / or a non-AP. When STA 110 and 200 perform an AP function, they may be referred to as AP for short, and when STA 110 and 200 perform a non-AP function, they may be referred to as STA for short. In addition, in the present disclosure, an AP may also be indicated as an APSTA.

[0039] refer to Figure 1 , the first device 100 and the second device 200 can send and receive radio signals through various wireless LAN technologies (eg, IEEE802.11 series). The first device 100 and the second device 200 may include interfaces for a media access control (MAC) layer and a physical layer (PHY) conforming to the IEEE802.11 standard.

[0040] In addition, the first device 100 and the second device 200 may additionally support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, etc.) technologies other than wireless LAN technology. In addition, the device of the present disclosure may be implemented in various devices, such as mobile phones, vehicles, personal computers, augmented reality (AR) devices, virtual reality (VR) devices, etc. In addition, the STA of the present specification may support various communication services, such as voice calls, video calls, data communications, autonomous driving, machine type communications (MTC), machine to machine (M2M), device to device (D2D), IoT (Internet of Things), etc.

[0041] The first device 100 may include one or more processors 102 and one or more memories 104, and may further include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memory 104 and / or the transceiver 106 and may be configured to implement the description, function, process, proposal, method and / or operation flow chart disclosed in the present disclosure. For example, the processor 102 may send a wireless signal including the first information / signal through the transceiver 106 after generating the first information / signal by processing the information in the memory 104. In addition, the processor 102 may receive a wireless signal including the second information / signal through the transceiver 106, and then store the information obtained by the signal processing of the second information / signal in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software code including instructions for executing all or part of the process controlled by the processor 102 or for executing the description, function, process, proposal, method and / or operation flow chart disclosed in the present disclosure. Here, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., LTE 802.11 series). The transceiver 106 may be connected to the processor 102 and may send and / or receive wireless signals through one or more antennas 108. The transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used in conjunction with an RF (radio frequency) unit. In the present disclosure, a device may refer to a communication modem / circuit / chip.

[0042] The second device 200 may include one or more processors 202 and one or more memories 204, and may further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memory 204 and / or the transceiver 206 and may be configured to implement the description, function, process, proposal, method and / or operation flow chart disclosed in the present disclosure. For example, the processor 202 may generate third information / signal by processing the information in the memory 204, and then send a wireless signal including the third information / signal through the transceiver 206. In addition, the processor 202 may receive a wireless signal including fourth information / signal through the transceiver 206, and then store the information obtained by signal processing of the fourth information / signal in the memory 204. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may store software code including instructions for executing all or part of the process controlled by the processor 202 or for executing the description, function, process, proposal, method and / or operation flow chart disclosed in the present disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., IEEE 802.11 series). The transceiver 206 may be connected to the processor 202 and may send and / or receive wireless signals through one or more antennas 208. The transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used in conjunction with an RF unit. In the present disclosure, a device may refer to a communication modem / circuit / chip.

[0043] In the following, the hardware elements of the device 100, 200 will be described in more detail. It is not limited thereto, but one or more protocol layers may be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 may implement one or more layers (e.g., functional layers such as PHY, MAC). One or more processors 102, 202 may generate one or more PDUs (protocol data units) and / or one or more SDUs (service data units) according to the description, function, process, proposal, method, and / or operation flow chart disclosed in the present disclosure. One or more processors 102, 202 may generate messages, control information, data, or information according to the description, function, process, proposal, method, and / or operation flow chart disclosed in the present disclosure. One or more processors 102, 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, processes, proposals, and / or methods disclosed in the present disclosure to provide them to one or more transceivers 106, 206. The one or more processors 102, 202 may receive signals (e.g., baseband signals) from the one or more transceivers 106, 206 and obtain PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, processes, proposals, methods, and / or operational flow charts disclosed in the present disclosure.

[0044] One or more processors 102, 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102, 202 may be implemented by hardware, firmware, software, or a combination thereof. In an example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) may be included in one or more processors 102, 202. The descriptions, functions, processes, proposals, methods, and / or operational flowcharts included in the present disclosure may be implemented using firmware or software and the firmware or software may be implemented to include modules, processes, functions, etc. Firmware or software configured to execute the descriptions, functions, processes, proposals, methods, and / or operational flowcharts included in the present disclosure may be included in one or more processors 102, 202 or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions, functions, processes, proposals, methods, and / or operational flowcharts included in the present disclosure may be implemented by firmware or software in the form of codes, commands, and / or command sets.

[0045] One or more memories 104, 204 may be connected to one or more processors 102, 202 and may store data, signals, messages, information, programs, codes, instructions, and / or commands in various forms. One or more memories 104, 204 may be configured with ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer-readable storage media, and / or combinations thereof. One or more memories 104, 204 may be located inside and / or outside one or more processors 102, 202. In addition, one or more memories 104, 204 may be connected to one or more processors 102, 202 via a variety of technologies such as wired or wireless connections.

[0046] One or more transceivers 106, 206 may send user data, control information, wireless signals / channels, etc. mentioned in the methods and / or operation flow charts, etc. of the present disclosure to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, processes, proposals, methods, and / or operation flow charts, etc. included in the present disclosure from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and may send and receive wireless signals. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to send user data, control information, or wireless signals to one or more other devices. In addition, one or more processors 102, 202 may control one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. In addition, one or more transceivers 106, 206 may be connected to one or more antennas 108, 208, and one or more transceivers 106, 206 may be configured to send and receive user data, control information, wireless signals / channels, etc. mentioned in the description, functions, processes, proposals, methods and / or operation flow charts, etc. included in the present disclosure through one or more antennas 108, 208. In the present invention, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106, 206 may convert received wireless signals / channels, etc. from RF band signals to baseband signals by using one or more processors 102, 202 to process received user data, control information, wireless signals / channels, etc. One or more transceivers 106, 206 may convert user data, control information, wireless signals / channels, etc. processed by using one or more processors 102, 202 from baseband signals to RF band signals. Therefore, one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

[0047] For example, one of the STAs 100 and 200 may perform the intended operation of an AP, and the other of the STAs 100 and 200 may perform the intended operation of a non-AP STA. Figure 1 The transceivers 106 and 206 of the present invention may perform transmission and reception operations of signals (e.g., packets or physical layer protocol data units (PPDUs) compliant with IEEE 802.11a / b / g / n / ac / ax / be). In addition, in the present disclosure, operations in which various STAs generate transmission / reception signals or perform data processing or calculation on transmission / reception signals in advance may be performed by Figure 1 The processors 102 and 202 are executed. For example, examples of operations of generating a transmit / receive signal or performing data processing or calculation on the transmit / receive signal in advance may include 1) determining / obtaining / configuring / calculating / decoding / encoding bit information of fields (signal (SIG), short training field (STF), long training field (LTF), data, etc.) included in the PPDU, 2) determining / configuring / obtaining time resources or frequency resources (e.g., subcarrier resources) used for fields (SIG, STF, LTF, data, etc.) included in the PPDU; 3) determining / configuring / obtaining a specific sequence (e.g., pilot sequence, STF / LTF sequence, additional sequence applied to SIG) for fields (SIG, STF, LTF, data, etc.) included in the PPDU action, 4) power control operations and / or power saving operations applied to STAs, 5) operations related to ACK signal determination / obtaining / configuring / calculating / decoding / encoding, etc. In addition, in the following examples, various information used by various STAs to determine / acquire / configure / calculate / decode / encode transmission and reception signals (e.g., information related to fields / subfields / control fields / parameters / power, etc.) may be stored in Figure 1 in the memories 104 and 204.

[0048] Hereinafter, downlink (DL) may mean a link for communication from an AP STA to a non-AP STA, and a DL PPDU / packet / signal may be transmitted and received through the DL. In DL communication, a transmitter may be a part of an AP STA, and a receiver may be a part of a non-AP STA. An uplink (UL) may mean a link for communication from a non-AP STA to an AP STA, and a UL PPDU / packet / signal may be transmitted and received through the UL. In UL communication, a transmitter may be a part of a non-AP STA, and a receiver may be a part of an AP STA.

[0049] Figure 2 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0050] The structure of a wireless LAN system may consist of multiple components. A wireless LAN that supports STA mobility transparent to upper layers may be provided through the interaction of multiple components. A basic service set (BSS) corresponds to a basic building block of a wireless LAN. Figure 2 It is exemplarily shown that two BSSs (BSS1 and BSS2) exist and two STAs are included as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). Figure 2 The ellipse representing the BSS in FIG. 1 may also be understood to represent a coverage area in which the STAs included in the corresponding BSS maintain communication. This area may be referred to as a basic service area (BSA). When a STA moves out of a BSA, it cannot directly communicate with other STAs in the BSA.

[0051] If you don't consider Figure 2 , the most basic type of BSS in a wireless LAN is an independent BSS (IBSS), if the DS shown in is included. For example, an IBSS may have a minimal form containing only two STAs. For example, assuming that other components are omitted, BSS1 containing only STA1 and STA2 or BSS2 containing only STA3 and STA4 may correspond to representative examples of IBSSs, respectively. This configuration is possible when STAs can communicate directly without an AP. In addition, in this type of wireless LAN, it is not configured in advance but can be configured when a LAN is needed, and this may be referred to as a self-organizing network. Because the IBSS does not include an AP, there is no centralized management entity. That is, in the IBSS, STAs are managed in a distributed manner. In an IBSS, all STAs may be composed of mobile STAs, and access to a distributed system (DS) is not allowed, thereby forming a self-contained network.

[0052] The membership of a STA in a BSS can be changed dynamically by turning the STA on or off, entering or exiting a BSS region, etc. To become a member of a BSS, a STA can join the BSS using a synchronization process. In order to access all services of the BSS infrastructure, a STA should be associated with the BSS. This association can be established dynamically and can include the use of distributed system services (DSS).

[0053] The direct STA-to-STA distance in a wireless LAN may be limited by PHY performance. In some cases, this distance limitation may be sufficient, but in some cases, communication between STAs at greater distances may be required. A distributed system (DS) can be configured to support extended coverage.

[0054] DS means a structure in which BSSs are interconnected. Specifically, Figure 2As shown in , the BSS can exist as an extended form of a network composed of multiple BSSs. DS is a logical concept and can be specified by the characteristics of the distributed system medium (DSM). In this regard, the wireless medium (WM) and the DSM can be logically separated. Each logical medium is used for a different purpose and is used by different components. These media are not limited to being the same or different. In this way, the flexibility of the wireless LAN structure (DS structure or other network structure) can be explained by the logical difference of multiple media. That is, the wireless LAN structure can be implemented in various ways, and the corresponding wireless LAN structure can be independently specified by the physical characteristics of each embodiment.

[0055] DS can support mobile devices by providing seamless integration of multiple BSSs and providing logical services necessary to address addresses to destinations. In addition, DS can further include a component called a portal, which serves as a bridge for connection between wireless LAN and other networks (e.g., IEEE 802.X).

[0056] The AP enables access to the DS through the WM for the associated non-AP STAs and means an entity that also has the functionality of a STA. Data movement between the BSS and the DS can be performed by the AP. For example, Figure 2 STA2 and STA3 shown in the figure have the functionality of STA and provide the function of allowing the associated non-AP STA (STA1 and STA4) to access the DS. In addition, because all APs basically correspond to STAs, all APs are addressable entities. The address used by the AP for communication on the WM and the address used by the AP for communication on the DSM are not necessarily the same. A BSS composed of an AP and one or more STAs can be called an infrastructure BSS.

[0057] Data sent from one of the STAs associated with an AP to the STA address of the corresponding AP can always be received on an uncontrolled port and can be processed by the IEEE 802.1X port access entity. In addition, when the controlled port is authenticated, the transmission data (or frame) can be delivered to the DS.

[0058] In addition to the above structure of DS, an extended service set (ESS) can also be configured to provide wide coverage.

[0059] ESS means a network in which a network of arbitrary size and complexity is composed of DS and BSS. ESS may correspond to a set of BSSs connected to one DS. However, ESS does not include DS. The ESS network is characterized by being regarded as an IBSS in the logical link control (LLC) layer. STAs included in the ESS can communicate with each other, and a mobile STA can move from one BSS to another BSS (within the same ESS) which is transparent to LLC. APs included in one ESS may have the same service set identifier (SSID). SSID is distinguished from BSSID, which is an identifier of BSS.

[0060] The wireless LAN system does not assume anything about the relative physical location of the BSS, and all of the following forms are possible. BSSs may partially overlap, which is a form commonly used to provide continuous coverage. In addition, the BSSs may not be physically connected, and logically, there is no limit to the distance between the BSSs. In addition, the BSSs may be physically located in the same location, which can be used to provide redundancy. In addition, one (or more) IBSSs or ESS networks may physically exist in the same space as one (or more) ESS networks. When an ad hoc network operates in a location where an ESS network exists, when physically overlapping wireless networks are configured by different organizations, or when two or more different access and security policies are required in the same location, this can be similar to the form corresponding to an ESS network.

[0061] Figure 3 is a diagram for explaining a link setting process to which the present disclosure can be applied.

[0062] In order for a STA to establish a link with respect to a network and send / receive data, it first discovers the network, performs authentication, establishes association, and needs to perform an authentication process for security. The link establishment process may also be referred to as a session initiation process or a session establishment process. In addition, the processes of discovery, authentication, association, and security settings of the link establishment process may be collectively referred to as an association process.

[0063] In step S310, the STA may perform a network discovery operation. The network discovery operation may include a scanning operation of the STA. That is, in order for the STA to access the network, it needs to find a network that it can participate in. The STA should identify compatible networks before participating in a wireless network, and the process of identifying networks existing in a specific area is called scanning.

[0064] Scanning schemes include active scanning and passive scanning. Figure 3The network discovery operation including the active scanning process is exemplarily illustrated. In active scanning, the STA performing the scan sends a probe request frame while moving the channel to find out which APs exist around it and wait for a response thereto. The responder sends a probe response frame to the STA that has sent the probe request frame as a response to the probe request frame. Here, the responder may be the STA that last sent a beacon frame in the BSS of the scanned channel. In the BSS, because the AP sends a beacon frame, the AP becomes the responder, and in the IBSS, the STAs in the IBSS take turns sending beacon frames, so the responder is not constant. For example, a STA that sends a probe request frame on channel 1 and receives a probe response frame on channel 1 may store the BSS-related information included in the received probe response frame, and may move to the next channel (e.g., channel 2) and perform scanning in the same manner (i.e., transmission / reception of probe requests / responses on channel 2).

[0065] Although Figure 3 Although not shown in the figure, the scanning operation can be performed in a passive scanning manner. In passive scanning, the STA performing the scan waits for a beacon frame while moving the channel. The beacon frame is one of the management frames defined in IEEE 802.11, and is sent periodically to notify the existence of a wireless network and allow the STA performing the scan to find the wireless network and participate in the wireless network. In the BSS, the AP is used to send beacon frames periodically, and in the IBSS, the STAs within the IBSS take turns to send beacon frames. When the STA performing the scan receives the beacon frame, the STA stores the information for the BSS included in the beacon frame and records the beacon frame information in each channel while moving to another channel. The STA receiving the beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform scanning in the next channel in the same manner. Comparing active scanning and passive scanning, active scanning has the advantages of less delay and lower power consumption than passive scanning.

[0066] After the STA discovers the network, an authentication process may be performed in step S320. In order to clearly distinguish it from the security setup operation of step S340 to be described later, this authentication process may be referred to as a first authentication process.

[0067] The authentication process includes a process in which the STA sends an authentication request frame to the AP, and in response thereto, the AP sends an authentication response frame to the STA. The authentication frame for authentication request / response corresponds to a management frame.

[0068] The authentication frame includes an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a robust security network (RSN), and a limited cycle group, etc. This corresponds to some examples of information that can be included in the authentication request / response frame, and can be replaced with other information or can further include additional information.

[0069] The STA may send an authentication request frame to the AP. The AP may determine whether to allow authentication of the corresponding STA based on the information included in the received authentication request frame. The AP may provide the result of the authentication process to the STA through an authentication response frame.

[0070] After the STA is successfully authenticated, an association process may be performed in step S330. The association process includes a process in which the STA sends an association request frame to the AP, and in response, the AP sends an association response frame to the STA.

[0071] For example, the association request frame may include information related to various capabilities, beacon listening interval, service set identifier (SSID), supported rates, supported channels, RSN, mobile domain, supported operation category, traffic indication map broadcast request (TIM broadcast request), interworking service capabilities, etc. For example, the association response frame may include information related to various capabilities, status code, association ID (AID), supported rates, enhanced distributed channel access (EDCA) parameter set, received channel power indicator (RCPI), received signal-to-noise ratio indicator (RSNI), mobile domain, timeout interval (e.g., association recovery time), overlapping BSS scanning parameters, TIM broadcast response, quality of service (QoS) map, etc. This corresponds to some examples of information that may be included in the association request / response frame, and may be replaced with other information, or may further include additional information.

[0072] After the STA successfully associates with the network, a security setup process may be performed in step S340. The security setup process of step S340 may be referred to as an authentication process through a robust security network association (RSNA) request / response, and the authentication process of step S320 may be referred to as a first authentication process, and the security setup process of step S340 may also be referred to simply as an authentication process.

[0073] The security setup process of step S340 may include, for example, a process of establishing a private key through a 4-way handshake of an Extensible Authentication Protocol over LAN (EAPOL) frame. In addition, the security setup process may be performed according to a security scheme not defined in the IEEE 802.11 standard.

[0074] Figure 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0075] In a wireless LAN system, the basic access mechanism of the medium access control (MAC) is the carrier sense multiple access with collision avoidance (CSMA / CA) mechanism. The CSMA / CA mechanism is also called the distributed coordination function (DCF) of the IEEE 802.11 MAC, and basically adopts a "listen before talk" access mechanism. According to this type of access mechanism, the AP and / or STA may perform a clear channel assessment (CCA) for sensing a wireless channel or medium within a predetermined time interval (e.g., a DCF interframe space (DIFS)) before starting transmission. As a result of the sensing, if it is determined that the medium is in an idle state, frame transmission is started through the corresponding medium. On the other hand, if it is detected that the medium is occupied or busy, the corresponding AP and / or STA does not start its own transmission, and a delay period (e.g., a random backoff period) for medium intervention may be set and frame transmission may be attempted after waiting. By applying a random backoff period, collisions can be minimized because several STAs are expected to attempt frame transmission after waiting for different time periods.

[0076] In addition, the IEEE 802.11 MAC protocol provides a hybrid coordination function (HCF). HCF is based on DCF and point coordination function (PCF). PCF is a polling-based synchronous access method, and refers to a method in which all receiving APs and / or STAs periodically poll to receive data frames. In addition, HCF has enhanced distributed channel access (EDCA) and HCF-controlled channel access (HCCA). EDCA is a contention-based access method for a provider to provide data frames to multiple users, and HCCA uses a non-contention-based channel access method using a polling mechanism. In addition, HCF includes a media access mechanism for improving the QoS (Quality of Service) of a wireless LAN, and QoS data can be sent in both a contention period (CP) and a contention-free period (CFP).

[0077] refer to Figure 4 , the operation based on the random backoff period will be described. When an occupied / busy medium becomes idle, several STAs may attempt to send data (or frames). As a method for minimizing collisions, each STA may select a random backoff count respectively and attempt to transmit after waiting for the corresponding time slot time. The random backoff count has a pseudo-random integer value and may be determined as one of the values ​​ranging from 0 to CW. Here, CW is the contention window parameter value. The CW parameter is assigned CWmin as an initial value, but may take a value twice as large if a transmission failure occurs (for example, when an ACK for a transmitted frame is not received). When the CW parameter value reaches CWmax, data transmission may be attempted while maintaining the CWmax value until data transmission is successful, and when data transmission is successful, the CWmin value is reset. The values ​​of CW, CWmin, and CWmax are preferably set to 2n -1 (n = 0, 1, 2, ...).

[0078] When the random backoff process starts, the STA continuously monitors the medium while counting down the backoff slot according to the determined backoff count value. When it detects that the medium is occupied, it stops the countdown and waits, and when the medium becomes idle, it resumes the remaining countdown.

[0079] exist Figure 4 In the example of , when the packet to be sent arrives at the MAC of STA3, STA3 can send the frame immediately after confirming that the medium is idle for as much as DIFS. The remaining STAs monitor and wait for the medium to be occupied / busy. At the same time, data to be sent may also occur in each of STA1, STA2 and STA5, and when the medium is monitored as idle, each STA waits as long as DIFS, and then the backoff slot can be counted down according to the random backoff count value selected by each STA. Assume that STA2 selects the minimum backoff count value and STA1 selects the maximum backoff count value. That is, the case where the remaining backoff time of STA5 is less than the remaining backoff time of STA1 when STA2 completes the backoff count and starts frame transmission is illustrated. STA1 and STA5 temporarily stop the countdown and wait while STA2 occupies the medium. When STA2 occupancy ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and resume the stopped backoff count. That is, after counting down the remaining backoff slot within the remaining backoff time, frame transmission can be started. Because the remaining backoff time of STA5 is less than that of STA1, STA5 starts frame transmission. While STA2 occupies the medium, data to be sent may also appear in STA4. From the perspective of STA4, when the medium becomes idle, STA4 can wait for DIFS, and then perform a countdown according to the random backoff count value selected by STA4 and start sending frames. Figure 4 The example shows a case where the remaining backoff time of STA5 coincides with the random backoff count value of STA4. In this case, a collision may occur between STA4 and STA5. When a collision occurs, neither STA4 nor STA5 receives an ACK, so data transmission fails. In this case, STA4 and STA5 can double the CW value, select a random backoff count value, and perform a countdown. STA1 waits while the medium is occupied due to the transmission of STA4 and STA5, waits for DIFS when the medium becomes idle, and then starts frame transmission after the remaining backoff time has elapsed.

[0080] like Figure 4As shown in the example of , a data frame is a frame for transmitting data forwarded to a higher layer, and may be sent after performing a backoff after DIFS has elapsed from when the medium becomes idle. In addition, a management frame is a frame for exchanging management information that is not forwarded to a higher layer, and is sent after performing a backoff after an IFS such as DIFS or a point coordination function IFS (PIFS). As subtype frames of the management frame, there are beacons, association request / responses, reassociation request / responses, probe request / responses, authentication request / responses, and the like. A control frame is a frame for controlling access to a medium. As subtype frames of the control frame, there are request to send (RTS), clear to send (CTS), acknowledgement (ACK), power save poll (PS-Poll), block ACK (BlockAck), block ACK request (BlockACKReq), empty data packet announcement (NDP announcement), and triggers, and the like. If the control frame is not a response frame of a previous frame, it is sent after performing a backoff after DIFS has elapsed, and if it is a response frame of a previous frame, it is sent without performing a backoff after a short IFS (SIFS) has elapsed. The type and subtype of a frame can be identified by the type field and subtype field in the frame control (FC) field.

[0081] Quality of Service (QoS) STA can perform a backoff performed after the arbitration IFS (AIFS) of the access category (AC) to which the frame belongs, that is, AIFS [i] (where i is a value determined by AC), and then can transmit the frame. Here, the frame that can use AIFS [i] may be a data frame, a management frame, or a control frame other than a response frame.

[0082] Figure 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0083] As described above, the CSMA / CA mechanism includes virtual carrier sensing in addition to the physical carrier sensing in which the STA directly senses the medium. Virtual carrier sensing is intended to compensate for problems that may occur in media access, such as hidden node problems. For virtual carrier sensing, the STA's MAC can use a network allocation vector (NAV). NAV is a value that indicates to other STAs the remaining time until the medium is available for use by the STA that is currently using or has the right to use the medium. Therefore, the value set to NAV corresponds to the period in which the medium is scheduled for use by the STA that sends the frame, and the STA that receives the NAV value is prohibited from accessing the medium during the corresponding period. For example, the NAV can be configured based on the value of the "Duration" field of the MAC header of the frame.

[0084] exist Figure 5In the example of FIG. 1 , it is assumed that STA1 intends to send data to STA2, and STA3 is in a position to eavesdrop on some or all frames sent and received between STA1 and STA2.

[0085] In order to reduce the possibility of transmission conflicts between multiple STAs in CSMA / CA-based frame transmission operations, a mechanism using RTS / CTS frames can be applied. Figure 5 In the example of , while STA1's transmission is being performed, as a result of STA3's carrier sensing, it can be determined that the medium is in an idle state. That is, STA1 may correspond to a hidden node of STA3. Alternatively, Figure 5 In the example of , it can be determined that the carrier sensing result medium of STA3 is in an idle state while the transmission of STA2 is performed. That is, STA2 may correspond to a hidden node of STA3. By performing the exchange of RTS / CTS frames before data transmission and reception between STA1 and STA2, STAs outside the transmission range of one of STA1 or STA2, or STAs outside the carrier sensing range for transmission from STA1 or STA3 may not attempt to occupy the channel during data transmission and reception between STA1 and STA2.

[0086] Specifically, STA1 can determine whether the channel is in use through carrier sensing. In terms of physical carrier sensing, STA1 can determine the channel occupancy idle state based on the energy level or signal correlation detected in the channel. In addition, in terms of virtual carrier sensing, STA1 can use the network allocation vector (NAV) timer to determine the channel occupancy state.

[0087] When the channel is idle during DIFS, STA1 may send an RTS frame to STA2 after performing backoff. When STA2 receives the RTS frame, STA2 may send a CTS frame to STA1 after SIFS as a response to the RTS frame.

[0088] If STA3 cannot eavesdrop on the CTS frame from STA2 but can eavesdrop on the RTS frame from STA1, STA3 can set the NAV timer for the subsequent consecutively transmitted frame transmission period (e.g., SIFS+CTS frame+SIFS+data frame+SIFS+ACK frame) using the duration information included in the RTS frame. Alternatively, if STA3 can eavesdrop on the CTS frame from STA2, although STA3 cannot eavesdrop on the RTS frame from STA1, STA3 can set the NAV timer for the subsequent consecutively transmitted frame transmission period (e.g., SIFS+data frame+SIFS+ACK frame) using the duration information included in the CTS frame. That is, if STA3 can eavesdrop on one or more of the RTS or CTS frames from one or more of STA1 or STA2, STA3 can set the NAV accordingly. When STA3 receives a new frame before the NAV timer expires, STA3 can update the NAV timer using the duration information included in the new frame. STA3 does not attempt channel access before the NAV timer expires.

[0089] When STA1 receives a CTS frame from STA2, STA1 may send a data frame to STA2 after SIFS from the time point when reception of the CTS frame is completed. When STA2 successfully receives the data frame, STA2 may send an ACK frame to STA1 as a response to the data frame after SIFS. STA3 may determine whether the channel is being used by carrier sensing when the NAV timer expires. When STA3 determines that the channel is not being used by other terminals during DIFS after the NAV timer expires, STA3 may attempt channel access after a contention window (CW) according to random backoff has elapsed.

[0090] Figure 6 is a diagram for explaining an example of a frame structure used in a WLAN system to which the present disclosure can be applied.

[0091] With the help of instructions or primitives (meaning a set of instructions or parameters) from the MAC layer, the PHY layer can prepare the MAC PDU (MPDU) to be sent. For example, when receiving a command requesting the PHY layer to start transmission from the MAC layer, the PHY layer switches to the transmission mode and configures the information (e.g., data) provided from the MAC layer in the form of a frame and sends it. In addition, when the PHY layer detects a valid preamble of the received frame, the PHY layer monitors the header of the preamble and sends a command to the MAC layer notifying the PHY layer of the start of reception.

[0092] In this manner, information transmission / reception in the wireless LAN system is performed in the form of a frame, and for this purpose, a PHY layer protocol data unit (PPDU) frame format is defined.

[0093] The basic PPDU frame may include a short training field (STF), a long training field (LTF), a signal (SIG) field, and a data field. The most basic PPDU format (e.g., Figure 7 The non-HT (high throughput) shown in the PPDU format may consist of only the legacy STF (L-STF), the legacy LTF (L-LTF), the legacy SIG (L-SIG) field and the data field. In addition, depending on the type of PPDU format (e.g., HT mixed format PPDU, HT-greenfield format PPDU, VHT (very high throughput) PPDU, etc.), additional (or different types of) RL-SIG, U-SIG, non-legacy SIG field, non-legacy STF, non-legacy LTF (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)), etc. may be included between the L-SIG field and the data field.

[0094] STF is a signal used for signal detection, automatic gain control (AGC), diversity selection, precise time synchronization, etc., and LTF is a signal used for channel estimation and frequency error estimation. STF and LTF may be referred to as signals for synchronization and channel estimation of the OFDM physical layer.

[0095] The SIG field may include various information related to PPDU transmission and reception. For example, the L-SIG field consists of 24 bits, and the L-SIG field may include a 4-bit rate field, a 1-bit reserved bit, a 12-bit length field, a 1-bit parity field, and a 6-bit tail field. The RATE field may include information about the modulation and coding rate of the data. For example, the 12-bit length field may include information about the length or duration of the PPDU. For example, the value of the 12-bit length field may be determined based on the type of PPDU. For example, for non-HT, HT, VHT, or EHT PPDUs, the value of the length field may be determined as a multiple of 3. For example, for HE PPDUs, the value of the length field may be determined as a multiple of 3 + 1 or a multiple of 3 + 2.

[0096] The data field may include a SERVICE field, a physical layer service data unit (PSDU), and a PPDU TAIL bit, and may also include padding bits if necessary. Some bits of the SERVICE field may be used for synchronization of the descrambler at the receiving end. The PSDU corresponds to the MAC PDU defined in the MAC layer and may include data generated / used in the upper layer. The PPDU TAIL bit may be used to return the encoder to the 0 state. The padding bit may be used to adjust the length of the data field in predetermined units.

[0097] MAC PDU is defined according to various MAC frame formats, and a basic MAC frame consists of a MAC header, a frame body, and a frame check sequence (FCS). A MAC frame can be composed of a MAC PDU and transmitted / received through a PSDU of the data portion of a PPDU frame format.

[0098] The MAC header includes a frame control field, a duration / ID field, an address field, etc. The frame control field may include control information required for frame transmission / reception. The duration / ID field may be set to the time for transmitting the corresponding frame, etc. For detailed information on the sequence control, QoS control, and HT control subfields of the MAC header, please refer to the IEEE 802.11 standard document.

[0099] The Null Data PPDU (NDP) format refers to a PPDU format that does not include a data field. That is, NDP refers to a frame format that includes a PPDU preamble (i.e., L-STF, L-LTF, L-SIG fields and additional non-legacy SIG, non-legacy STF, non-legacy LTF (if present)) in a general PPDU frame format and does not include the remaining part (i.e., data field).

[0100] Figure 7 is a diagram illustrating an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0101] In standards such as IEEE 802.11a / g / n / ac / ax, various types of PPDUs have been used. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and data fields. The basic PPDU format may also be referred to as non-HT PPDU format (such as Figure 7 (shown in (a)).

[0102] The HT PPDU format (IEEE 802.11n) includes HT-SIG, HT-STF, and HT-LFT fields in addition to the basic PPDU format. Figure 7 The HT PPDU format shown in (b) may be referred to as an HT-mixed format. In addition, an HT-greenfield format PPDU may be defined, and this corresponds to a format consisting of an HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs, and a data field, excluding L-STF, L-LTF, and L-SIG (not shown).

[0103] An example of a VHT PPDU format (IEEE 802.11ac) includes VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields in addition to the basic PPDU format (e.g. Figure 7 (shown in (c)).

[0104] An example of the HE PPDU format (IEEE 802.11ax) includes, in addition to the basic PPDU format, repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), a packet extension (PE) field (such as Figure 7 (d)). According to the detailed example of the HE PPDU format, some fields may be excluded or their lengths may vary. For example, the HE-SIG-B field is included in the HE PPDU format for multi-user (MU), and the HE-SIG-B field is not included in the HE PPDU format for single user (SU). In addition, the PPDU format based on the HE trigger (TB) does not include the HE-SIG-B, and the length of the HE-STF field may vary to 8us. The extended range (HE ER) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may vary to 16us. For example, the RL-SIG can be configured to be the same as the L-SIG. The receiving STA is able to know whether the received PPDU is a HE PPDU or an EHT PPDU based on the presence of the RL-SIG, which will be described later.

[0105] The EHT PPDU format may include Figure 7 (e) EHT MU (multi-user) and Figure 7 (f) EHT TB (trigger-based) PPDU. The EHT PPDU format is similar to the HE PPDU format in that it includes the RL-SIG followed by the L-SIG, but may include the U (Universal)-SIG, EHT-SIG, EHT-STF, and EHT-LTF following the RL-SIG.

[0106] Figure 7 The EHT MU PPDU in (e) corresponds to a PPDU that carries one or more data (or PSDU) for one or more users. That is, the EHT MU PPDU can be used for both SU transmission and MU transmission. For example, the EHT MU PPDU can correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0107] Compared with EHT MU PPDU, Figure 7The EHT TB PPDU in (f) omits the EHT-SIG. A STA that receives a trigger (eg, a trigger frame or a trigger response schedule (TRS)) for UL MU transmission may perform UL transmission based on the EHT TB PPDU format.

[0108] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal Signal), EHT-SIG fields may be coded and modulated so that even legacy STAs may attempt to demodulate and decode, and may be mapped based on a determined subcarrier frequency interval (e.g., 312.5 kHz). These may be referred to as pre-EHT modulation fields. Next, the EHT-STF, EHT-LTF, Data, PE fields may be coded and modulated so that they may be demodulated and decoded by a STA that successfully decodes a non-legacy SIG (e.g., U-SIG and / or EHT-SIG) and obtains the information included in the field, and may be mapped based on a determined subcarrier frequency interval (e.g., 78.125 kHz). These may be referred to as EHT modulation fields.

[0109] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields may be referred to as pre-HE modulation fields, and the HE-STF, HE-LTF, Data, and PE fields may be referred to as HE modulation fields. In addition, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields may be referred to as free VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and data fields may be referred to as VHT modulation fields.

[0110] Figure 7 The U-SIG included in the EHT PPDU format may be configured based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) used for the U-SIG may have a duration of 4us, and the U-SIG may have a total duration of 8us. Each symbol of the U-SIG may be used to transmit 26 bits of information. For example, each symbol of the U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0111] U-SIG can be constructed in units of 20MHz. For example, if an 80MHz PPDU is constructed, the U-SIG may be repeated. That is, the 80MHz PPDU may include the same 4 U-SIGs. PPDUs with bandwidths exceeding 80MHz may include different U-SIGs.

[0112] For example, A uncoded bits may be sent via U-SIG, the first symbol of U-SIG (e.g., U-SIG-1 symbol) may send the first X bits of information out of the total A bits of information, and the second symbol of U-SIG (e.g., U-SIG-2 symbol) may send the remaining Y bits of information out of the total A bits of information. The A bits of information (e.g., 52 uncoded bits) may include a CRC field (e.g., a 4-bit long field) and a tail field (e.g., a 6-bit long field). For example, the tail field may be used to terminate a grid of a convolutional decoder and may be set to 0.

[0113] The bit information sent by U-SIG can be divided into version-independent bits and version-dependent bits. For example, U-SIG can be included in Figure 7 In a new PPDU format not shown in the EHT PPDU format (e.g., UHR PPDU format), and in the format of the U-SIG field included in the EHT PPDU format and the format of the U-SIG field included in the UHR PPDU format, the version-independent bits may be the same, and some or all of the version-related bits may be different.

[0114] For example, the size of the version-independent bit of the U-SIG may be fixed or variable. The version-independent bit may be assigned only to the U-SIG-1 symbol, or to both the U-SIG-1 symbol and the U-SIG-2 symbol. The version-independent bit and the version-dependent bit may be referred to by various names, such as a first control bit and a second control bit.

[0115] For example, the version-independent bits of the U-SIG may include a 3-bit physical layer version identifier (PHY version identifier), and this information may indicate the PHY version of the transmitted / received PPDU (e.g., EHT, UHR, etc.). The version-independent bits of the U-SIG may include a 1-bit UL / DL flag field. The first value of the 1-bit UL / DL flag field is related to UL communication, and the second value of the UL / DL flag field is related to DL communication. The version-independent bits of the U-SIG may include information about the length of a transmission opportunity (TXOP) and information about a BSS color ID.

[0116] For example, the version-related bits of the U-SIG may include information directly or indirectly indicating the PPDU type (eg, SUPPDU, MU PPDU, TB PPDU, etc.).

[0117] Information necessary for PPDU transmission and reception may be included in the U-SIG. For example, the U-SIG may further include information about bandwidth, information about an MCS technology applied to a non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.), information indicating whether a DCM (dual carrier modulation) technology (e.g., a technology that achieves an effect similar to frequency diversity by repeatedly using the same signal on two subcarriers) is applied to the non-legacy SIG, information about the number of symbols used for the non-legacy SIG, information about whether the non-legacy SIG is generated across the entire band, and the like.

[0118] Some information necessary for PPDU transmission and reception may be included in the U-SIG and / or the non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.). For example, information about the type of non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information about the length of the non-legacy LTF and the CP (cyclic prefix) length, information about the GI (guard interval) applicable to the non-legacy LTF, information about preamble puncturing applicable to the PPDU, information about RU (resource unit) allocation, etc. may be included only in the U-SIG, only in the non-legacy SIG, or may be indicated by a combination of information included in the U-SIG and information included in the non-legacy SIG.

[0119] Preamble puncturing may mean transmission of a PPDU in which there is no signal in one or more frequency units within the bandwidth of the PPDU. For example, the size of the frequency unit (or the resolution of the preamble puncturing) may be defined as 20 MHz, 40 MHz, etc. For example, preamble puncturing may be applied to a PPDU bandwidth of a predetermined size or greater.

[0120] exist Figure 7 In the example of , non-legacy SIGs such as HE-SIG-B and EHT-SIG may include control information for receiving STAs. Non-legacy SIGs may be transmitted on at least one symbol, and one symbol may have a length of 4us. Information on the number of symbols used for EHT-SIG may be included in a previous SIG (eg, HE-SIG-A, U-SIG, etc.).

[0121] Non-legacy SIGs such as HE-SIG-B and EHT-SIG may include common fields and user-specific fields. Common fields and user-specific fields may be compiled separately.

[0122] In some cases, the common field can be omitted. For example, in a compressed mode that does not apply OFDMA (Orthogonal Frequency Multiple Access), the common field can be omitted, and multiple STAs can receive PPDUs (e.g., data fields of PPDUs) through the same frequency band. In a non-compressed mode that applies OFDMA, multiple users can receive PPDUs (e.g., data fields of PPDUs) through different frequency bands.

[0123] The number of user-specific fields may be determined based on the number of users. A user block field may include up to two user fields. Each user field may be associated with a MU-MIMO allocation or may be associated with a non-MU-MIMO allocation.

[0124] The common field may include CRC bits and tail bits, and the length of the CRC bits may be determined to be 4 bits, and the length of the tail bits may be determined to be 6 bits and set to 000000. The common field may include RU allocation information. The RU allocation information may include information about the locations of RUs assigned to multiple users (ie, multiple receiving STAs).

[0125] RU can include multiple subcarriers (or tones). RU can be used when sending signals to multiple STAs based on OFDMA technology. In addition, RU can be defined even when sending signals to one STA. Resources can be allocated in units of RU for non-legacy STF, non-legacy LTF and data fields.

[0126] The applicable size of RU can be defined according to the PPDU bandwidth. For the applied PPDU format (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.), the RU can be defined the same or differently. For example, in the case of 80MHz PPDU, the RU placement of HEPPDU and EHT PPDU may be different. The applicable RU size, RU number and RU position, DC (direct current) subcarrier position and number, empty subcarrier position and number, protection subcarrier position and number, etc. for each PPDU bandwidth can be referred to as a tone plan. For example, a tone plan for high bandwidth can be defined in the form of multiple iterations of a low bandwidth tone plan.

[0127] RUs of various sizes may be defined as 26-tone RUs, 52-tone RUs, 106-tone RUs, 242-tone RUs, 484-tone RUs, 996-tone RUs, 2Х996-tone RUs, 3Х996-tone RUs, etc. MRUs (multiple RUs) are distinguished from multiple individual RUs and correspond to a group of subcarriers consisting of multiple RUs. For example, one MRU may be defined as 52+26 tones, 106+26 tones, 484+242 tones, 996+484 tones, 996+484+242 tones, 2Х996+484 tones, 3Х996 tones, or 3Х996+484 tones. In addition, the multiple RUs constituting one MRU may or may not be continuous in the frequency domain.

[0128] The specific size of the RU may be reduced or enlarged. Therefore, the specific size of each RU (i.e., the number of corresponding tones) in the present disclosure is not restrictive and is illustrative. In addition, in the present disclosure, within a predetermined bandwidth (e.g., 20, 40, 80, 160, 320 MHz, ...), the number of RUs may vary depending on the RU size.

[0129] Figure 7 The name of each field in the PPDU format is exemplary, and the scope of the present disclosure is not limited by the name. In addition, the examples of the present disclosure may be applied to Figure 7 The PPDU format shown in FIG. Figure 7 The PPDU format of the present invention excludes some fields and / or adds some fields to the new PPDU format.

[0130] Multi-link operation

[0131] Hereinafter, a multi-link operation supported by a STA according to the present disclosure will be described.

[0132] The STA (AP STA and / or non-AP STA) described in the present disclosure may support multi-link (ML) communication. ML communication may refer to communication that supports multiple links. Links related to ML communication may include channels (e.g., 20 / 40 / 80 / 160 / 240 / 320 MHz channels) in a frequency band (e.g., 2.4 GHz band, 5 GHz band, 6 GHz band, etc.) in which the STA operates. Multiple links for ML communication can be configured in various ways. For example, multiple links for ML communication supported by one STA may belong to the same frequency band or to different frequency bands. In addition, each link may correspond to a frequency unit of a predetermined size (e.g., a channel, a sub-channel, an RU, etc.). In addition, all or part of the multiple links may be frequency units of the same size, or may be frequency units of different sizes.

[0133] When one STA supports multiple links, the transmitting or receiving device supporting each link can operate like one logical STA. In other words, MLD refers to a device that has at least one affiliated STA as a logical entity and has a single MAC Service Access Point (SAP) for one MAC data service and logical link control (LLC). Non-AP MLD refers to an MLD in which each STA belonging to the corresponding MLD is a non-AP STA. Multi-radio non-AP MLD refers to a non-AP MLD that supports receiving or exchanging frames in at least one link at a time. AP MLD refers to an MLD in which each STA belonging to the corresponding MLD is an AP STA.

[0134] Multi-link operation (MLO) enables non-AP MLDs to discover, authenticate, and associate with AP MLDs and set up multiple links. Each link enables channel access and frame exchange between non-AP MLDs and AP MLDs based on the supported capabilities exchanged during the association process. STAs affiliated with an MLD can select and manage their capabilities and operating parameters independently of other STAs affiliated with the same MLD.

[0135] Through the multi-link setup process, the AP MLD and / or the non-AP MLD may transmit or receive link-related information that may be supported by the corresponding MLD. The link-related information may include at least one of the following: whether it is a simultaneous transmission and reception (STR) operation that can transmit or receive simultaneously on multiple links or a non-simultaneous transmission and reception (NSTR) operation that cannot transmit or receive simultaneously, information about the number / upper limit of UL / DL links, information about the location / band / resource of the UL / DL links, information about available or preferred frame types (e.g., management, control, data) in at least one UL / DL link, information about available or preferred ACK policies in at least one UL / DL link, or information about available traffic identifiers (TIDs) in at least one UL / DL link supported by the corresponding MLD.

[0136] An AP MLD (e.g., NSTR mobile AP MLD) may configure one of the multiple links as a primary link. The AP MLD may perform beacon frames, probe response frames, and group-addressed data frames only on the primary link. The remaining other links of the multiple links may be referred to as non-primary links. An AP MLD operating on a non-primary link may operate not to send beacon frames or probe response frames. In addition, a non-AP MLD may perform frame exchanges during authentication, (re)association, and a four-way handshake only on the primary link.

[0137] When at least one traffic identifier (TID) is mapped to the corresponding link through the multi-link setup process, the setup link can be defined as enabled, and when there is no TID mapped to the corresponding link, the setup link can be defined as disabled. Unless admission control is used, a TID should always be mapped to at least one setup link. Basically, a TID is mapped to all setup links, so all setup links can be activated.

[0138] When a link is activated, the corresponding link can be used for frame exchange according to the power state of the non-AP STA operating in the corresponding link. Only MSDUs or A-MSDUs with TIDs mapped to active links can be sent in the corresponding link. Management frames and control frames can only be sent in active links.

[0139] When a link is deactivated, the corresponding link may be unused for frame exchange by including management frames for DL ​​and UL.

[0140] In the multi-link setup process, activation / deactivation of each link may be indicated by TID-to-link mapping. TID-to-link mapping may be performed in a default mapping mode or / and a negotiated mapping mode.

[0141] Random access in multi-link operation

[0142] One STA among the STAs belonging to the MLD may provide information about at least one link other than its link for multi-link discovery (e.g., obtaining information about multiple links including a corresponding link on one link) or multi-link setup (e.g., simultaneous association on multiple links through exchange between association request / response frames on one link). In order to provide this information, a multi-link (ML) element may be defined.

[0143] Figure 8 The structure of the ML element to which the present disclosure can be applied is exemplarily shown.

[0144] exist Figure 8 In the ML element (or ML Information Element (IE)) of (a), the Element ID field and the Element ID Extension field may have specific values ​​(e.g., 255 and 107) showing that they are ML elements, and the Length field may have a value showing the length of the remaining fields (e.g., octet units) except the Element ID field and the Length field.

[0145] Figure 8 (b) shows Figure 8(a) An exemplary format of the multi-link control field. For example, the multi-link control field is defined to have a size of 2 octets and may include a 3-bit type subfield, a 1-bit reserved bit, and a 12-bit presence bitmap subfield. The type subfield may have a value indicating one of the types such as basic, probe request, reconfiguration, tunnel direct link setup (TDLS), priority access, etc. The presence bitmap subfield shows whether various subfields exist within the common information field and may be defined in different formats according to various variants of the ML element (or the above types).

[0146] Figure 8 (c) shows Figure 8 (a) An exemplary format of the common information field in (a). The common information field may be defined to have a variable size. The common information length subfield may indicate the number of octets included in the common information field (including 1 octet of the common information length subfield). The 6-octet MLD MAC address subfield may have a value specifying the MAC address of the MLD to which the STA that sends the basic ML element belongs. In addition, the link ID information subfield, the BSS parameter change count subfield, the medium synchronization delay information subfield, the enhanced multi-link (EML) capability subfield, the MLD capability and operation subfield, the AP MLD ID subfield, the extended MLD capability and operation subfield, etc. may or may not be included in the common information field.

[0147] Figure 8 The link information field in (a) is defined to have a variable size and may include link-specific information and may optionally exist. When the link information field exists, it may include at least one sub-element. The format and order of the sub-elements can be defined in various ways. As an example of an optional sub-element ID for a basic variant ML element, a sub-element ID value of 0 corresponds to the name of each STA profile and is extensible, and a sub-element ID value of 221 corresponds to a vendor-specific name and whether it can be extended can be determined by the vendor, and a sub-element ID value of 254 corresponds to the name of the fragment and is not extensible, and the remaining values ​​1-220, 222-253, and 255 may be reserved.

[0148] Figure 8(d) shows an example format of each STA profile sub-element. Each STA profile sub-element may include a 1-octet sub-element ID sub-field, a 1-octet length sub-field, a 2-octet STA control sub-field, a variable-sized STA information sub-field, and a variable-sized STA profile sub-field. The STA control sub-field may include information such as a link ID, whether a complete profile is included, whether a STA MAC address exists, etc. The STA information sub-field may include information such as a STA MAC address, etc. The STA profile sub-field may include information included in a probe response or probe request frame body, information included in a (re)association response or (re)association request frame body, etc., depending on whether the reported STA is an AP STA or a non-AP STA.

[0149] Figure 8 The format of the ML element in is exemplary, and the order, name, size, etc. of the fields / subfields may be changed, additional fields / subfields may be further defined, and some fields / subfields may be excluded. In other words, the common information field may include common information between STAs in the MLD, and the link information field may include specific information about each STA / link (e.g., in a per-STA profile sub-element including a link ID corresponding to the corresponding STA).

[0150] Fig. 9 is a diagram showing an exemplary relationship between a multi-BSSID set and a multi-link device to which the present disclosure may be applied.

[0151] The multi-BSSID operation may include one access point (AP) physically operating by generating multiple virtual APs in one channel. In the following description, the multi-BSSID may be indicated as MBSSID.

[0152] The MBSSID set includes at least one non-transmitting BSSID and may define one transmitting BSSID.

[0153] exist Fig. 9 In the example of , x, y, p, q, r, a, and b correspond to exemplary values ​​of the BSSID, [T] represents a transmitting BSSID (or Tx BSSID), and a BSSID not indicating [T] represents a non-transmitting BSSID (or non-Tx BSSID).

[0154] exist Fig. 9In the example of , when considering both MBSSID operation and ML operation, some BSSIDs within one MBSSID set may belong to an MLD, and each of the multiple links belonging to one MLD may correspond to a channel (or a BSSID operating in a corresponding channel). Different MLDs may operate on multiple links on the same or different channels. For example, Link 0 (L0), Link 1 (L1), and Link 2 (L2) of MLD1 may be configured on CH1, CH2, and CH3, respectively. For example, L0 and L1 of MLD2 may be configured on CH2 and CH3, respectively. For example, L0 and L1 of MLD3 may be configured on CH1 and CH2, respectively. BSSID-c may not belong to an MLD.

[0155] Fig.10 is a diagram for describing an example of an ML element to which an MBSSID element of the present disclosure can be applied.

[0156] This information may be provided by including information about multiple (virtual) APs in one management frame (eg, beacon, probe response, (re)association response), and for this purpose, an MBSSID element (or MBSSID Information Element (IE)) may be defined.

[0157] For example, in Fig. 9 In the example of , BSSID-a of MLD 1 may belong to the MBSSID set on CH3 and correspond to the Tx BSSID in the MBSSID set. The Tx BSSID (e.g., BSSID-a) may also provide the STA with information about non-Tx BSSIDs such as BSSID-b and BSSID-c through the MBSSID element included in the management frame (e.g., beacon, probe response, (re)association response frame) including its information. Here, BSSID-c does not belong to MLD, but BSSID-b belongs to MLD 2. The MBSSID element included in the management frame sent by BSSID-a may include the ML element in the profile of the AP corresponding to BSSID-b, which is a non-Tx BSSID.

[0158] For example, in a probe response frame or a beacon frame, but not in a multi-link (ML) probe response frame sent by a Tx BSSID, an ML element (e.g., a basic ML element carrying information about an AP MLD to which an AP corresponding to a non-Tx BSSID belongs) may be included in a non-Tx BSSID profile within an MBSSID element. Alternatively, in an ML probe response sent by a Tx BSSID, the ML element may be included in the body portion of the ML probe response (rather than the MBSSID element). Alternatively, in a probe response frame or a beacon frame, but not in an ML probe response frame, when the AP corresponding to the non-Tx BSSID profile within the MBSSID element belongs to an MLD, the ML element in the corresponding non-Tx BSSID profile may include a common information field and a per-STA profile, and information about an AP on another link of the MLD may not include a field. Alternatively, in an ML probe response, an ML element (not an MBSSID element) included in the body portion of the ML probe response may include a per-STA profile field, which is information about an AP on another link of the corresponding MLD. Fig.10 In the example of FIG. 1 , it is described by assuming that the ML element is included in the MBSSID element, but the examples of the present disclosure may also be applied when the ML element is included in the body part of the ML probe response frame.

[0159] Specifically, Fig.10 An example of inheritance corresponding to a complete per-STA profile for MBSSID scenario. For example, Fig.10The inheritance is exemplarily shown when each STA profile carries a complete profile of a basic ML element included in a non-Tx BSSID profile from an MBSSID element. The corresponding example shows a management frame sent by an AP corresponding to a Tx BSSID. The management frame carries at least one element with each element ID, and the element ID is indicated in brackets as A, B, C, ... The corresponding frame also carries an MBSSID element including a profile for a non-Tx BSSID N. The non-Tx BSSID profile includes a basic ML element that carries a complete profile for AP x. BSSID N inherits elements with IDs B, C, and E. Elements with IDs D and F are specific to BSSID N and appear in its non-Tx BSSID profile. In addition, BSSID N does not inherit elements with ID A and elements included in non-inherited elements. Because the value of element F for BSSID N is different from the value announced by the Tx BSSID, the corresponding element is included in the profile for BSSID N. The element with ID Y is specific to BSSID N and is included in its profile. AP x inherits elements with IDs D and F from BSSID N, and indirectly inherits element with ID C from Tx BSSID (e.g., by inheriting BSSID N). AP x does not inherit element A (equal to non-Tx BSSID). Elements with IDs B and Y are specific to AP x and are included in its profile. In addition, AP x does not inherit element E from Tx BSSID, and does not inherit IDs included in non-inherited elements present in its profile.

[0160] In other words, as described above, an AP within an MLD can send information of other APs within the same MLD to a STA by including it in an ML element. Fig. 9 As shown in the example of , when the MBSSID set and the MLD are mixed, the ML element may be included in the MBSSID element and provided from the AP to the STA.

[0161] Here, since the ML element basically includes information about a plurality of APs, if the number of AP STAs is large and / or the number of elements to be inherited is small, the ML element may exceed 255 octets. Generally, fragmentation may be applied to elements exceeding 255 octets, but fragmentation may not be applied to MBSSID elements, and when fragmentation is applied to a non-TxBSSID profile, a plurality of MBSSID elements may be used.

[0162] In other words, when the non-Tx BSSID includes an ML element, if fragmentation of the MBSSID element is allowed, step-by-step fragmentation for multiple (sub-)elements is required, which may require complex rules and make it difficult for non-AP STAs to decode the MBSSID elements sent from the AP STA (based on fragments).

[0163] In this case, fragmentation can also be prevented by defining and applying the MLD ID. For example, the MLD ID of the MLD to which the non-Tx BSSID belongs can be included in the (basic) ML element included in the request frame (e.g., probe request frame, multi-link (ML) probe request frame, (re) association request frame) from the STA, and complete profile information for the corresponding MLD can be requested. In this case, information corresponding to the non-Tx BSSID can be included in the non-Tx BSSID profile of the MBSSID element within the response frame (e.g., probe response frame, ML probe response frame, (re) association response frame), and information about other APs of the MLD to which the corresponding non-Tx BSSID belongs can be included in each per-STA profile together with signaling information for the MLD ID within the (basic) ML element (instead of the MBSSID element of the response frame).

[0164] Here, the AP that sends the response frame may be referred to as a reporting AP, and another AP that belongs to the same MLD as the reporting AP may be referred to as a reported AP. Information about the reporting AP may be included in the body of the response frame (i.e., an element of the response frame that is not included in the MBSSID element (i.e., outside the MBSSID element)), and information about the reported AP may be included in a per-STA profile within a (basic) ML element of the response frame.

[0165] When the complete profile information is requested via a request frame, inheritance rules may be applied between the information included in the frame body of the response frame (i.e., elements not included in the MBSSID element and / or the ML element) (i.e., the complete profile for the reporting AP) and the per-STA profile information within the (Basic) ML element (i.e., the complete profile for each reported AP).

[0166] When there is information / elements of the reported AP that match the information / elements of the reporting AP, it can be omitted from the per-STA profile of the reported AP within the (basic) ML element, thereby reducing overhead. Information / elements of the reported AP that do not match the information of the reporting AP and / or information / elements not included in the body of the response frame corresponding to the information of the reporting AP (i.e., elements not included in the MBSSID element and / or the ML element) (i.e., additional information / elements) can be included in the corresponding per-STA profile of the reported AP within the (basic) ML element. In addition, when there is information / elements that do not correspond to the reported AP among the information / elements of the reporting AP, which information / element is not inherited can be indicated by a non-inherited element.

[0167] The above-mentioned inheritance rules can be summarized as follows. According to the inheritance rules for the MBSSID element, for multiple BSSIDs within the same MBSSID set, among the information of the non-Tx BSSID, the same information as the information of the Tx BSSID can be omitted, and information different from the Tx BSSID or information additional to the Tx BSSID can be included in the MBSSID profile. Next, according to the inheritance rules of the (basic) ML element, for multiple APs within the same MLD, among the information of the reported AP, the same information as the information of the reporting AP can be omitted, and information different from the reporting AP or information additional to the reporting AP can be included in the per-STA profile.

[0168] This inheritance rule can be applied when the reporting AP and the reported AP belong to the same MLD. In other words, the inheritance rule that can be applied when the reporting AP and the reported AP belong to different MLDs is not defined. Therefore, a new inheritance-related method is needed, in which the AP effectively provides (basic) ML elements without applying fragments to the MBSSID element.

[0169] The present disclosure describes various examples of new inheritance rules that can be applied when the reporting AP and the reported AP belong to different MLDs and different MBSSID sets in a situation where MBSSID and MLD are mixed. For example, the present disclosure describes various examples of determining a reference for inheritance based on MLD and MBSSID sets by including a non-Tx BSSID and applying inheritance rules based thereon to efficiently provide information.

[0170] Fig.11 is a diagram for describing an example of a method for a STA to obtain information related to a plurality of APs according to the present disclosure.

[0171] In S1110, the STA may send a request frame including information related to another AP / MLD to the first AP. For example, the request frame may include information indicating at least one of the second AP or the first MLD. For example, the first AP may belong to the second MLD. For example, the first AP may be an AP corresponding to the transmitted (Tx) BSSID.

[0172] For example, the request frame may correspond to a probe request frame, an ML probe request frame, an association request frame, a reassociation request frame, and the like.

[0173] In S1120, as a response to the request frame, the STA may receive a response frame from the first AP, the response frame including information on applying inheritance or non-inheritance based on a non-transmitting (non-Tx) BSSID profile. For example, the response frame may include at least one per-STA profile. Inheritance or non-inheritance for at least one per-STA profile may be based on a non-Tx BSSID profile. In other words, the non-Tx BSSID profile may become a reference for inheritance or non-inheritance. In addition, the first AP may correspond to a reporting AP.

[0174] The profile of the non-Tx BSSID may be included in the multi-BSSID (MBSSID) element as an inherited or non-inherited reference. In other words, information included in the MBSSID element included in the response frame, rather than the body portion of the response frame (i.e., elements not included in the MBSSID element) (among the non-Tx BSSID profile) may be defined or applied as an inherited or non-inherited reference. For example, the profile of the non-Tx BSSID may correspond to a profile of an AP belonging to the same MLD as the second AP (indicated by the request frame) or a profile of an AP belonging to the first MLD (indicated by the request frame).

[0175] For example, inheritance may separately include information or elements identical to those of a profile of a non-Tx BSSID (ie, an inherited reference) that are omitted in at least one per-STA profile.

[0176] For example, non-inheritance may include, in at least one per-STA profile, at least one information or element that is different from or not included in the profile of the AP corresponding to the non-Tx BSSID (i.e., non-inherited reference). Information indicating this non-inheritance information or element may be included in a non-inheritance field within the response frame.

[0177] At least one per-STA profile may be included in a (Basic) ML element. The (Basic) ML element may be included within an MBSSID element or an ML probe response. The (Basic) ML element may include a complete per-STA profile for at least one reported AP.

[0178] For example, the response frame may correspond to a probe response frame, an ML probe response frame, an association response frame, a reassociation response frame, or the like.

[0179] Fig.11 The method described in the example can be Figure 1 The first device (100) performs. For example, Figure 1 At least one processor (102) of the first device (100) may be configured to send a request frame and receive a response frame thereto through at least one transceiver (106). In addition, at least one memory (104) of the first device (100) may store instructions for executing, when executed by the at least one processor (102), Fig.11 The methods described in the examples or instructions of the methods described in the examples described below.

[0180] Fig.12 is a diagram for describing an example of a method for an AP to provide information about a plurality of APs to a STA according to the present disclosure.

[0181] In S1210, the first AP may receive a request frame including information related to another AP / MLD from the STA. The other AP / MLD may correspond to at least one of the second AP or the first MLD, and information indicating the other AP / MLD may be included in the request frame. For example, the first AP may belong to the second MLD. For example, the first AP may be an AP corresponding to the Tx BSSID.

[0182] In S1220, the first AP may send a response frame including information on applying inheritance or non-inheritance based on the non-Tx BSSID profile to the STA as a response to the request frame. For example, the response frame may include at least one per-STA profile, and its inheritance or non-inheritance may be based on the non-Tx BSSID profile. In other words, the non-Tx BSSID profile may become a reference for inheritance or non-inheritance. In addition, the first AP may correspond to a reporting AP.

[0183] Specific details on inheritance or non-inheritance of non-Tx BSSID-based at least one per-STA profile included in a response frame and examples and examples for request frames and response frames Fig.11 The examples are the same as those described in , so repeated descriptions are omitted.

[0184] Fig.12 The method described in the example can be Figure 1 The second device (200) executes. For example, Figure 1At least one processor (202) of the second device (200) may be configured to receive the request frame through at least one transceiver (206) and send a response frame thereto. In addition, at least one memory (204) of the second device (200) may store instructions for executing when executed by the at least one processor (202) Fig.12 Examples or instructions of the methods described in the examples described below.

[0185] Fig.11 and Fig.12 Examples may correspond to some of the various examples of the present disclosure. Fig.11 and Fig.12 Examples of various examples of the present disclosure.

[0186] In the following embodiments, a probe request frame and a probe response frame are described as representative examples to which the present disclosure is applied, but the following embodiments may be equally applied even when the probe request / response frame is replaced with an ML probe request / response frame, an association request / response frame, a reassociation request / response frame, or another management frame.

[0187] Example 1

[0188] As described above, when the STA requests information about the MLD to which the AP corresponding to the non-Tx BSSID belongs and some or all of the APs belonging thereto, the body part of the ML probe response sent by the AP corresponding to the Tx BSSID (i.e., the MBSSID element and / or an element not included in the ML element) may include information about the Tx BSSID, the non-Tx BSSID profile of the MBSSID element in the ML probe response may include information about the non-Tx BSSID, and the (basic) ML element in the MBSSID element or in the ML probe response may include information about another AP (e.g., requested by the STA) belonging to the MLD to which the AP corresponding to the non-Tx BSSID belongs.

[0189] In other words, by using the AP corresponding to the non-Tx BSSID as a reference, the inheritance rule may be applied to the reported APs of the per-STA profile belonging to the (base) ML element (eg, other APs belonging to the same MLD as the corresponding non-Tx BSSID).

[0190] For example, a profile of a non-TxBSSID belonging to the same MBSSID set as the reporting AP (or Tx BSSID) and belonging to the MLD requested by the STA may be a reference for inheritance / non-inheritance applied to the response frame.

[0191] For example, information about another AP / BSSID may be provided to the STA through a response frame by applying information of an AP corresponding to a non-Tx BSSID belonging to an MLD different from the MLD to which the reporting AP belongs and to the MBSSID set to which the reporting AP belongs as a reference for inheritance / non-inheritance.

[0192] Fig.13 An example of inheritance / non-inheritance application based on a non-Tx BSSID profile according to the present disclosure is shown.

[0193] refer to Fig. 9 Explained with examples Fig.13 In the example of , it is assumed that BSSID-q corresponding to the Tx BSSID among the MBSSID set on CH2 corresponds to an AP that exchanges request / response frames with the STA, that is, a reporting AP. The request frame from the STA may include information indicating a target (that is, the reported AP) for which the STA requests information, for example, information indicating MLD 1. In other words, the STA may request information about the AP belonging to MLD 1 from BSSID-q belonging to MLD 2. In this case, the reference for inheritance / non-inheritance of the information included in the response frame may not be the profile of BSSID-q as the Tx BSSID, but the profile of BSSID-p belonging to MLD 1 requested by the STA among the non-Tx BSSIDs of the MBSSID set (that is, the MBSSID set on CH2) to which the AP corresponding to the Tx BSSID belongs. The profile of BSSID-p may not be included in the body part of the response frame (that is, an element not included in the MBSSID element), but may be included in the MBSSID element of the response frame.

[0194] In this way, the application of the inheritance rule can be based on the relationship between APs belonging to different MLDs. When the information of the AP belonging to MLD 1 is provided to the STA, when the inheritance rule is applied by using the information of the AP belonging to MLD 2 as a reference, the probability that the AP information is repeated may be low. Therefore, it may be difficult to achieve the effect of reducing the overhead of the response frame, which is the purpose of applying the inheritance rule.

[0195] Therefore, when MLD information for a non-Tx BSSID is requested, in order to effectively apply the inheritance rule in a response thereto, the existing inheritance rule needs to be changed.

[0196] Basically, the inheritance rule can be applied by using the information present in the non-Tx BSSID profile as a reference. In other words, the AP corresponding to the non-Tx BSSID can be used as a reference to apply the inheritance rule to the reported APs of the per-STA profile included in the (base) ML element (i.e., APs belonging to the same MLD as the AP corresponding to the non-Tx BSSID as the reference).

[0197] Specifically, when there is information / element matching the information / element of the non-Tx BSSID profile as a reference, among the information / element of the per-STA profile of the reported AP of the (basic) ML element, the corresponding information / element may be omitted to reduce the overhead of the response frame.

[0198] When there is information / element that does not match the information / element belonging to the non-Tx BSSID profile as a reference among the information / element of the per-STA profile of the reported AP of the (basic) ML element, or when there is additional information / element that does not exist in the non-Tx BSSID profile as a reference or in the body part of the response frame, the corresponding information / element may be included in the response frame.

[0199] When there is information / elements that do not correspond to information of the reported AP among the information / elements of the non-Tx BSSID profile as a reference, which information / element is not inherited may be indicated (eg, in a list form) by a non-inherited element included in the response frame.

[0200] The reference in the inheritance / non-inheritance rule applied to the response frame in the existing WLAN system is the information / profile of the reporting AP (or Tx BSSID) included in the response frame body (i.e., an element not included in the MBSSID element), however, the reference in the inheritance / non-inheritance rule according to various examples of the present disclosure may be the information / profile of the AP corresponding to the non-Tx BSSID. Therefore, when providing information about the MLD requested by the STA, it is possible to effectively achieve overhead reduction of the response frame by using the profile of the non-Tx BSSID that is likely to include information common to the information of the AP belonging to the corresponding MLD as a reference for inheritance / non-inheritance.

[0201] The above-mentioned embodiments are elements and features of the present disclosure combined in a predetermined form. Unless otherwise explicitly mentioned, each element or feature should be considered optional. Each element or feature can be implemented in a form that is not combined with other elements or features. In addition, the embodiments of the present disclosure may include combined partial elements and / or features. The order of the operations described in the embodiments of the present disclosure may be changed. Some elements or features of an embodiment may be included in other embodiments, or may be replaced by corresponding elements or features of other embodiments. It is clear that an embodiment may include a combined claim without an explicit dependency in the claim, or may be included as a new claim by modification after application.

[0202] It is clear to those skilled in the art that the present disclosure can be implemented in other specific forms within the scope of the essential features of the present disclosure. Therefore, the above detailed description should not be interpreted restrictively in every aspect, but should be considered as illustrative. The scope of the present invention should be determined by the reasonable interpretation of the attached claims, and all changes within the equivalent scope of the present disclosure are included in the scope of the present invention.

[0203] The scope of the present disclosure includes software or machine executable commands (e.g., operating systems, applications, firmware, programs, etc.) that perform operations in a device or computer according to the methods of various embodiments, and non-transitory computer-readable media that store such software or commands, etc. and can be executed in a device or computer. Commands that can be used to program a processing system that performs the features described in the present disclosure can be stored in a storage medium or a computer-readable storage medium, and the features described in the present disclosure can be implemented by using a computer program product that includes such a storage medium. The storage medium may include a high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid-state storage devices, but is not limited thereto, and it may include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory optionally includes one or more storage devices located away from the processor. The memory or alternatively, the non-volatile memory device in the memory includes a non-transitory computer-readable storage medium. The features described in this disclosure may be stored in any machine-readable medium to control the hardware of a processing system, and may be integrated into software and / or firmware that allows the processing system to interact with other mechanisms using the results from embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0204] [Industrial Applicability]

[0205] The method proposed by the present disclosure is mainly described based on an example of being applied to an IEEE 802.11-based system and a 5G system, but can also be applied to various WLAN or wireless communication systems other than the IEEE 802.11-based system.

Claims

1. A method performed by a station (STA) in a wireless local area network (WLAN) system, the method comprising: sending a request frame to a first access point (AP), the request frame comprising information related to at least one of a second access point (AP) or a first multi-link device (MLD); as well as receiving a response frame to the request frame from the first AP, wherein the response frame includes at least one per-STA profile, The inheritance or non-inheritance of the at least one per-STA profile is based on a non-transmit (non-Tx) basic service set identifier (BSSID) profile.

2. The method according to claim 1, wherein: The profile of the non-Tx BSSID is included in a multi-BSSID (MBSSID) element.

3. The method according to claim 2, wherein: The at least one per-STA profile is included in a multi-link (ML) element.

4. The method according to claim 3, wherein: The ML element includes a complete per-STA profile for at least one reported AP.

5. The method according to claim 3, wherein: The ML element is included in the body of the response frame outside the MBSSID element.

6. The method according to claim 1, wherein: The profile of the non-Tx BSSID corresponds to a profile of an AP belonging to the same MLD as the second AP or a profile of an AP belonging to the first MLD.

7. The method according to claim 1, wherein: The first AP belongs to a second MLD.

8. The method of claim 1, wherein: The first AP is an AP corresponding to a BSSID of transmission (Tx).

9. The method according to claim 1, wherein: The inheritance individually includes, in the at least one per-STA profile, the same information or elements as those of the omitted profile of the non-Tx BSSID.

10. The method of claim 1, wherein: The non-inherited individually includes, in the at least one per-STA profile, at least one information or element different from a profile for an AP corresponding to the non-Tx BSSID, or at least one information or element not included in the profile for the AP corresponding to the included non-Tx BSSID.

11. The method according to claim 1, wherein: The non-inherited field within the response frame includes information indicating at least one information or element different from a profile for the AP corresponding to the non-Tx BSSID or at least one information or element not included in the profile for the AP corresponding to the non-Tx BSSID.

12. The method of claim 1, wherein: The request frame is one of a probe request frame, an ML probe request frame, an association request frame or a reassociation request frame, The response frame is one of a probe response frame, an ML probe response frame, an association response frame or a re-association response frame.

13. A station (STA) device in a wireless local area network (WLAN) system, the device comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: sending, by the at least one transceiver, a request frame to a first access point (AP), the request frame including information related to at least one of a second access point (AP) or a first multi-link device (MLD); and receiving, by the at least one transceiver, a response frame to the request frame from the first AP, wherein the response frame includes at least one per-STA profile, The inheritance or non-inheritance of the at least one per-STA profile is based on a non-transmit (non-Tx) basic service set identifier (BSSID) profile.

14. A method performed by a first access point (AP) in a wireless local area network (WLAN) system, the method comprising: receiving, from a station (STA), a request frame including information related to at least one of a second access point (AP) or a first multi-link device (MLD); as well as sending a response frame to the request frame to the STA, wherein the response frame includes at least one per-STA profile, The inheritance or non-inheritance of the at least one per-STA profile is based on a non-transmit (non-Tx) basic service set identifier (BSSID) profile.

15. A first access point (AP) device in a wireless local area network (WLAN) system, the device comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: receiving, by the at least one transceiver, a request frame from a station (STA), the request frame including information related to at least one of a second access point (AP) or a first multi-link device (MLD); and sending a response frame to the request frame to the STA through the at least one transceiver, wherein the response frame includes at least one per-STA profile, The inheritance or non-inheritance of the at least one per-STA profile is based on a non-transmit (non-Tx) basic service set identifier (BSSID) profile.

16. A processing unit configured to control a station (STA) in a wireless local area network (WLAN) system, the processing unit comprising: at least one processor; as well as At least one computer memory, the at least one computer memory being operatively connected to the at least one processor and storing instructions for executing the method according to any one of claims 1 to 12 upon execution by the at least one processor.

17. At least one non-transitory computer-readable medium storing at least one instruction, wherein: The at least one instruction is executed by at least one processor to control a device to perform the method according to any one of claims 1 to 12 in a wireless local area network (WLAN) system.

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