Method and apparatus for indicating link for specific type traffic in wireless LAN system

Abstract

Disclosed are a method and an apparatus for indicating a link for a specific type of traffic in a wireless LAN system. According to an embodiment of the present disclosure, a method performed by a first station (STA) in a wireless LAN system may comprise the steps of: transmitting, to a second STA, a flow classification service (SCS) request frame including information related to negotiation of a specific type of traffic; and receiving an SCS response frame in response to the SCS request frame from the second STA. Here, at least one of the SCS request frame or the SCS response frame may include link-related information indicating at least one link over which a particular traffic type is to be transmitted and received.

Description

TECHNICAL FIELD

[0001] The disclosure relates to a method and apparatus for indicating a link for a specific type of traffic in a wireless local area network (WLAN) system. BACKGROUND

[0002] New technologies for increasing transmission rates, increasing bandwidth, improving reliability, reducing errors, and reducing latency have been introduced for wireless LANs (WLANs). Among WLAN technologies, the Institute of Electrical and Electronics Engineers (IEEE) 802.11 series standards can be referred to as Wi-Fi. For example, technologies recently introduced to WLANs include very high throughput (VHT) enhancements of the 802.11ac standard and high efficiency (HE) enhancements of the IEEE 802.11ax standard.

[0003] In order to provide a more advanced wireless communication environment, improved technologies for extremely high throughput (EHT) are being discussed. For example, technologies for MIMO and multi-access point (AP) coordination that support increased bandwidth, efficient use of multiple frequency bands, and increased spatial streams are being researched, and in particular, various technologies are being researched to support low latency or real-time traffic. In addition, new technologies are being discussed to support ultra-high reliability (UHR), including improvements or extensions of EHT technologies. SUMMARY

[0004] TECHNICAL PROBLEM

[0005] The technical object of the disclosure is to provide a method and apparatus for indicating a link for a specific type of traffic.

[0006] The technical object of the disclosure is to provide a method and apparatus for indicating a link for low latency traffic based on a stream classification service (SCS) negotiation procedure.

[0007] The technical objects to be achieved by the disclosure are not limited to the aforementioned technical objects, and other technical objects not described herein will be clearly understood by persons skilled in the art from the following description.

[0008] TECHNICAL SOLUTION

[0009] According to one aspect of the disclosure, a method performed by a first station (STA) in a wireless LAN system can include transmitting, to a second STA, an SCS request frame including information related to negotiation of a specific type of traffic, and receiving, from the second STA, an SCS response frame in response to the SCS request frame. Here, at least one of the SCS request frame or the SCS response frame can include link-related information indicating one or more links through which the specific type of traffic is to be transmitted and received.

[0010] According to an additional aspect of the present disclosure, a method, which can be performed by a second station (STA) in a wireless LAN system, can include receiving, from a first STA, an SCS request frame including information related to negotiation of a specific type of traffic, and transmitting, to the first STA, an SCS response frame in response to the SCS request frame. Here, at least one of the SCS request frame or the SCS response frame can include link-related information indicating one or more links through which the specific type of traffic is to be transmitted and received.

[0011] Technical Effects

[0012] According to the present disclosure, it is possible to provide a method and apparatus indicating a link for a specific type of traffic.

[0013] According to the present disclosure, it is possible to provide a method and apparatus indicating a link for low latency traffic based on a stream classification service (SCS) negotiation procedure.

[0014] Effects that can be achieved by the present disclosure are not limited to what has been described above and other effects not described above will become apparent to those skilled in the art from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0015] The accompanying drawings, which are included as part of the specific embodiments for understanding the present disclosure, provide embodiments of the present disclosure and describe technical features of the present disclosure together with the specific embodiments.

[0016] Figure 1 A configuration block 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 explaining a link setup process to which the present disclosure can be applied.

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

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

[0021] 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.

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

[0023] Figure 8 A Quality of Service (QOS) characteristics element applicable to the embodiments of the disclosure is exemplified.

[0024] Figure 9 An SCS descriptor element applicable to the embodiments of the disclosure is exemplified.

[0025] Figure 10 An MLO link information element according to the embodiments of the disclosure is exemplified.

[0026] Figure 11 An SCS descriptor element including a link information element according to the embodiments of the disclosure is exemplified.

[0027] Figure 12 A QoS characteristics element including a link ID bitmap field according to the embodiments of the disclosure is exemplified.

[0028] Figure 13 An operation flowchart performed by a first STA according to the embodiments of the disclosure is exemplified.

[0029] Figure 14 An operation flowchart performed by a second STA according to the embodiments of the disclosure is exemplified. DETAILED DESCRIPTION

[0030] Hereinafter, embodiments according to the disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed by the accompanying drawings is intended to describe exemplary embodiments of the disclosure, and is not intended to represent the only embodiments in which the disclosure can be implemented. The following detailed description includes specific details to provide a complete understanding of the disclosure. However, those skilled in the relevant art will know that the disclosure can be implemented without the specific details.

[0031] In some cases, known structures and devices can be omitted, or can be shown in the form of a block diagram based on the core function of each structure and device in order to facilitate the prevention of obscuring the concept of the disclosure.

[0032] In the disclosure, when an element is referred to as being "connected", "combined", or "linked" to another element, it can include an indirect connection relationship between the other element and the element through still another element therebetween as well as a direct connection relationship. In addition, in the disclosure, the term "including" or "having" specifies the existence of the mentioned features, steps, operations, components, and / or elements, but does not exclude the existence or addition of one or more other features, stages, operations, components, elements, and / or groups thereof.

[0033] In the present disclosure, terms such as "first", "second", and the like are used to distinguish one element from another element and do not limit the elements unless otherwise specified, and do not limit the order or importance between the elements, etc. Therefore, within the scope of the present disclosure, a first element in an embodiment can be referred to as a second element in another embodiment, and likewise, a second element in an embodiment can be referred to as a first element in another embodiment.

[0034] The terms used in the present disclosure are used to describe specific embodiments and are not intended to limit the claims. As used in the description of the embodiments and the appended claims, the singular forms are intended to include the plural forms unless the context clearly dictates otherwise. The term "and / or" used in the present disclosure can refer to one of the relevant listed items, or mean that it refers to and includes any and all possible combinations of two or more of them. In addition, unless otherwise specified, " / " between words in the present disclosure has the same meaning as "and / or".

[0035] Examples of the present disclosure can be applied to various wireless communication systems. For example, examples of the present disclosure can be applied to a wireless LAN system. For example, examples of the present disclosure can be applied to a wireless LAN based on IEEE 802.11a / g / n / ac / ax standards. In addition, examples of the present disclosure can be applied to a wireless LAN based on a newly proposed IEEE 802.11be (or EHT) standard. Examples of the present disclosure can be applied to a wireless LAN based on an IEEE 802.11be version 2 standard corresponding to additional enhancement technologies of the IEEE 802.11be version 1 standard. In addition, examples of the present disclosure can be applied to a wireless LAN based on a next-generation standard after the IEEE 802.11be. Furthermore, examples of the present disclosure can be applied to a cellular wireless communication system. For example, it can be applied to a long-term evolution (LTE) based technology based on a third generation partnership project (3GPP) standard and a cellular wireless communication system based on a 5G new radio (NR) technology.

[0036] Hereinafter, technical features to which examples of the present disclosure can be applied will be described.

[0037] Figure 1 A block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0038] Figure 1The first and second apparatuses 100 and 200 exemplified in the middle can be replaced with various terms such as a terminal, a wireless device, a wireless transmit / receive unit (WTRU), a user equipment (UE), a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a mobile subscriber unit (MSU), a subscriber station (SS), an advanced mobile station (AMS), a wireless terminal (WT), or simply a user, etc. In addition, the first and second apparatuses 100 and 200 include an access point (AP), a base station (BS), a fixed station, a node-B, a base transceiver system (BTS), a network. It can be replaced with various terms such as an artificial intelligence (AI) system, a road side unit (RSU), a repeater, a router, a relay, and a gateway.

[0039] Figure 1 The apparatuses 100 and 200 exemplified in the middle can be referred to as a station (STA). For example, Figure 1 The apparatuses 100 and 200 exemplified in the middle can be referred to as a station (STA). For example,

[0040] Referring to Figure 1 The first and second apparatuses 100 and 200 can transmit and receive radio signals through various wireless LAN technologies (for example, IEEE 802.11 series). The first and second apparatuses 100 and 200 can include an interface for a medium access control (MAC) layer and a physical layer (PHY) to comply with the IEEE 802.11 standard.

[0041] In addition, the first and second apparatuses 100 and 200 can additionally support various communication standard (for example, 3GPP LTE series, 5G NR series standards, etc.) technologies in addition to the wireless LAN technology. In addition, the apparatuses of the present disclosure can be implemented in various apparatuses such as a mobile phone, a vehicle, a personal computer, an augmented reality (AR) device, and a virtual reality (VR) device, etc. In addition, the STAs of the present specification can support various communication services such as a voice call, a video call, data communication, autonomous driving, machine type communication (MTC), machine-to-machine (M2M), device-to-device (D2D), IoT (Internet of Things), etc.

[0042] The first apparatus 100 can include one or more processors 102 and one or more memories 104, and can additionally include one or more transceivers 106 and / or one or more antennas 108. The processor 102 can control the memory 104 and / or the transceiver 106, and can be configured to implement descriptions, functions, procedures, suggestions, methods and / or operational flowcharts included in the present disclosure. For example, the processor 102 can generate first information / signal by processing information in the memory 104, and then transmit a wireless signal including the first information / signal through the transceiver 106. Also, the processor 102 can receive a wireless signal including second information / signal through the transceiver 106, and then store information obtained by processing a signal of the second information / signal in the memory 104. The memory 104 can be connected to the processor 102 and can store a variety of information related to operations of the processor 102. For example, the memory 104 can store software code including instructions for performing all or a part of processes controlled by the processor 102 or for performing descriptions, functions, procedures, suggestions, methods and / or operational flowcharts included in the present disclosure. Here, the processor 102 and the memory 104 can be a part of a communication modem / circuit / chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). The transceiver 106 can be connected to the processor 102 and can transmit and / or receive a wireless signal through the one or more antennas 108. The transceiver 106 can include a transmitter and / or a receiver. The transceiver 106 can be used together with an RF (Radio Frequency) unit. In the present disclosure, a wireless device can mean a communication modem / circuit / chip.

[0043] The second apparatus 200 can include one or more processors 202 and one or more memories 204, and can additionally include one or more transceivers 206 and / or one or more antennas 208. The processor 202 can control the memory 204 and / or the transceiver 206, and can be configured to implement descriptions, functions, procedures, suggestions, methods and / or operational flowcharts included in the present disclosure. For example, the processor 202 can generate third information / signal by processing information in the memory 204, and then transmit a wireless signal including the third information / signal through the transceiver 206. Also, the processor 202 can receive a wireless signal including fourth information / signal through the transceiver 206, and then store information obtained by signal processing through the fourth information / signal in the memory 204. The memory 204 can be connected to the processor 202 and can store a variety of information related to operations of the processor 202. For example, the memory 204 can store software code including instructions for performing all or part of processes controlled by the processor 202 or for performing descriptions, functions, procedures, suggestions, methods and / or operational flowcharts included in the present disclosure. Here, the processor 202 and the memory 204 can be part of a communication modem / circuit / chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). The transceiver 206 can be connected to the processor 202 and can transmit and / or receive a wireless signal through the one or more antennas 208. The transceiver 206 can include a transmitter and / or a receiver. The transceiver 206 can be used together with an RF unit. In the present disclosure, an apparatus can mean a communication modem / circuit / chip.

[0044] Hereinafter, the hardware elements of the apparatuses 100, 200 will be described in more detail. Without limitation, one or more protocol layers can be implemented by the one or more processors 102, 202. For example, the one or more processors 102, 202 can implement one or more layers (e.g., functional layers such as PHY, MAC). The one or more processors 102, 202 can generate one or more PDUs (Protocol Data Units) and / or one or more SDUs (Service Data Units) according to the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure. The one or more processors 102, 202 can generate messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure. The one or more processors 102, 202 can generate signals (e.g., baseband signals) including the PDUs, SDUs, messages, control information, data, or information according to the functions, procedures, suggestions, and / or methods disclosed in the present disclosure to provide the same to the one or more transceivers 106, 206. The one or more processors 102, 202 can receive signals (e.g., baseband signals) from the one or more transceivers 106, 206 according to the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts included in the present disclosure, and obtain the PDUs, SDUs, messages, control information, data, or information.

[0045] The one or more processors 102, 202 can be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or more processors 102, 202 can be implemented by hardware, firmware, software, or a combination thereof. For example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processors Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) can be included in the one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts included in the present disclosure can be implemented by using firmware or software, and the firmware or software can be implemented as including modules, procedures, functions, etc. The firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts included in the present disclosure can be included in the one or more processors 102, 202, or can be stored in the one or more memories 104, 204 and driven by the one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods, and / or operational flowcharts included in the present disclosure can be implemented by using firmware or software in the form of codes, instructions, and / or instruction sets.

[0046] One or more memories 104, 204 can be connected to one or more processors 102, 202 and can store data, signals, messages, information, programs, codes, instructions, and / or commands in various forms. One or more memories 104, 204 can be configured with ROM, RAM, EPROM, flash memory, hard drives, registers, cache memories, computer-readable storage media, and / or combinations thereof. One or more memories 104, 204 can be located internal and / or external to one or more processors 102, 202. In addition, one or more memories 104, 204 can be connected to one or more processors 102, 202 by various technologies such as wired or wireless connections.

[0047] The one or more transceivers 106, 206 can transmit user data, control information, wireless signals / channels, etc. mentioned in the methods and / or operational flowcharts, etc. of the disclosure to one or more other apparatuses. The one or more transceivers 106, 206 can receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, processes, suggestions, methods and / or operational flowcharts, etc. included in the disclosure from one or more other apparatuses. For example, the one or more transceivers 106, 206 can be connected to the one or more processors 102, 202 and can transmit and receive wireless signals. For example, the one or more processors 102, 202 can control the one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other apparatuses. In addition, the one or more processors 102, 202 can control the one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other apparatuses. In addition, the one or more transceivers 106, 206 can be connected to the one or more antennas 108, 208, and the one or more transceivers 106, 206 can be configured to transmit and receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, processes, suggestions, methods and / or operational flowcharts, etc. included in the disclosure through the one or more antennas 108, 208. In the disclosure, the one or more antennas can be a plurality of physical antennas or a plurality of logical antennas (for example, antenna ports). The one or more transceivers 106, 206 can convert received wireless signals / channels, etc. from RF band signals to baseband signals to process received user data, control information, wireless signals / channels, etc. by using the one or more processors 102, 202. The one or more transceivers 106, 206 can convert user data, control information, wireless signals / channels, etc. processed by using the one or more processors 102, 202 from baseband signals to RF band signals. Accordingly, the one or more transceivers 106, 206 can include (analog) oscillators and / or filters.

[0048] For example, one of the STAs 100 and 200 can perform the intended operation of an AP, and the other of the STAs 100 and 200 can perform the intended operation of a non-AP STA. For example, Figure 1 The transceivers 106 and 206 of the STA 100 and 200 can perform transmission and reception operations of signals (for example, packets or physical layer protocol data units (PPDUs) conforming to IEEE 802.11a / b / g / n / ac / ax / be / bn). In addition, in the disclosure, operations in which various STAs generate transmission / reception signals or perform data processing or calculation in advance for transmission / reception signals can be performed by the one or more processors 102, 202. Figure 1The operations of generating a transmission / reception signal or performing data processing or calculation in advance for the operations of the transmission / reception signal can include, for example, 1) determining / acquiring / configuring / calculating / decoding / encoding bit information of a field (a signal (SIG), a short training field (STF), a long training field (LTF), data, etc.) included in a PPDU; 2) determining / configuring / acquiring a time resource or a frequency resource (e.g., a subcarrier resource) for a field (SIG, STF, LTF, data, etc.) included in a PPDU; 3) determining / configuring / acquiring a specific sequence (e.g., a pilot sequence, an STF / LTF sequence, an additional sequence applied to SIG) for a field (SIG, STF, LTF, data, etc.) included in a PPDU action; 4) a power control operation and / or a power saving operation applied to a STA; 5) an operation related to ACK signal determination / acquisition / configuration / calculation / decoding / encoding, etc. In addition, in the following examples, various information (e.g., information related to a field / subfield / control field / parameter / power, etc.) used by various STAs to determine / acquire / configure / calculate / decode / encode a transmission signal and a reception signal can be stored in the memories 104 and 204 of the processors 102 and 202. Figure 1

[0049] Hereinafter, a downlink (DL) can mean a link for communication from an AP STA to a non-AP STA, and a DL PPDU / packet / signal can be transmitted and received through the DL. In the DL communication, a transmitter can be a part of the AP STA, and a receiver can be a part of the non-AP STA. An uplink (UL) can mean a link for communication from a non-AP STA to an AP STA, and a UL PPDU / packet / signal can be transmitted and received through the UL. In the UL communication, a transmitter can be a part of the non-AP STA, and a receiver can be a part of the AP STA.

[0050] Figure 2 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0051] The structure of the wireless LAN system can be composed of a plurality of components. The wireless LAN supporting mobility of a STA transparent to an upper layer can be provided through the interaction of the plurality of components. A basic service set (BSS) corresponds to a basic building block of the wireless LAN. Figure 2 Exemplarily, it is shown that there are two BSSs (BSS1 and BSS2), and two STAs (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2) are included as members of each BSS. Figure 2 ​The ellipse representing the BSS can also be understood to represent a coverage area in which the STAs included in the corresponding BSS maintain communication. This area can be referred to as a basic service area (BSA). When a STA moves outside the BSA, it cannot directly communicate with other STAs within the BSA.

[0052] If the DS shown in Figure 2 The most basic BSS type in a wireless LAN, if the DS shown in

[0053] The membership of STAs in a BSS can be dynamically changed by turning on or off a STA, entering or exiting a BSS area, etc. In order 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. The association can be dynamically established and can include the use of a distribution system service (DSS).

[0054] The direct STA-to-STA distance in a wireless LAN can be limited by the PHY performance. In some cases, this distance limitation can be sufficient, but in some cases, communication between STAs at a longer distance can be required. A distribution system (DS) can be configured to support extended coverage.

[0055] The DS means a structure of interconnection of BSSs. Specifically, as Figure 2As shown, the BSS can exist as an extended form of a network composed of a plurality of BSSs. The DS is a logical concept, and can be specified by the characteristics of a 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 a different component. These media are not limited to being the same, nor are they limited to being different. In this way, the flexibility of the wireless LAN structure (DS structure or other network structure) can be interpreted as the plurality of media being logically different. 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 implementation.

[0056] The DS can support mobile devices by providing seamless integration of a plurality of BSSs and providing logical services necessary for addressing addresses leading to destinations. In addition, the DS can also include a component called a portal, which is used as a bridge for a connection between the wireless LAN and other networks (for example, IEEE 802.X).

[0057] The AP enables access to the DS through the WM for an associated non-AP STA, and means an entity that also has the function of a STA. Data movement between the BSS and the DS can be performed through the AP. For example, Figure 2 The STAs 2 and 3 shown in FIG. 1 have the function of a STA, and provide a function that allows an associated non-AP STA (STAs 1 and 4) to access the DS. In addition, since all APs basically correspond to STAs, all APs are addressable entities. The address used by the AP to communicate on the WM is not necessarily the same as the address used by the AP to communicate on the DSM. A BSS composed of an AP and one or more STAs can be referred to as an infrastructure BSS.

[0058] Data transmitted from one of the STAs associated with the AP to the STA address of the corresponding AP can always be received at an uncontrolled port, and can be processed by an IEEE 802.1X port access entity. In addition, when the controlled port is authenticated, the transmitted data (or frame) can be delivered to the DS.

[0059] In addition to the structure of the DS described above, an extended service set (ESS) can be configured to provide a wide coverage range.

[0060] The ESS means a network composed of DSs and BSSs with arbitrary size and complexity. The ESS can correspond to a set of BSSs connected to one DS. However, the ESS does not include the DS. The ESS network is characterized as 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) transparently to the LLC. The APs included in one ESS can have the same service set identification (SSID). The SSID is distinguished from the BSSID which is an identifier of the BSS.

[0061] The wireless LAN system does not assume anything about the relative physical locations of BSSs, and all of the following forms are possible. BSSs can partially overlap, which is a form commonly used to provide continuous coverage. In addition, BSSs can not be physically connected, and logically, there is no limit to the distance between BSSs. In addition, BSSs can be physically located at the same location, which can be used to provide redundancy. In addition, one (or more than one) IBSS or ESS network can physically exist in the same space as one (or more than one) ESS network. This can correspond to a form of ESS network 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, and the like.

[0062] Figure 3 is a diagram for explaining a link establishment process to which the present disclosure can be applied.

[0063] In order for a STA to establish a link with respect to a network and transmit / receive data, it first discovers the network, performs authentication, establishes association, and needs to perform an authentication process for security. The link establishment process can also be referred to as a session initiation process or a session establishment process. In addition, the discovery, authentication, association, and security establishment processes of the link establishment process can be collectively referred to as an association process.

[0064] In step S310, the STA can perform a network discovery operation. The network discovery operation can include a scanning operation of the STA. That is, in order for the STA to access a network, it needs to find a network that it can participate in. The STA should identify a compatible network before participating in a wireless network, and the process of identifying a network present in a specific area is referred to as scanning.

[0065] The scanning scheme includes active scanning and passive scanning. Figure 3A network discovery operation including an active scan process is exemplarily illustrated. In the active scan, the STA performing the scan transmits a probe request frame to discover what APs exist around it while the channel moves and waits for a response thereto. The responder transmits a probe response frame as a response to the probe request frame to the STA having transmitted the probe request frame. Here, the responder can be the STA which last transmitted a beacon frame in the BSS of the channel being scanned. In the BSS, since the AP transmits the beacon frame, the AP becomes the responder, and in the IBSS, the STAs in the IBSS rotate to transmit the beacon frame, so the responder is not constant. For example, the STA which transmits the probe request frame on channel 1 and receives the probe response frame on channel 1 can store the BSS-related information included in the received probe response frame, and can move to the next channel (e.g., channel 2) and perform the scan in the same manner (i.e., transmission and reception of the probe request / response on channel 2).

[0066] Although not shown in Figure 3 , a scan operation can be performed in a passive scan manner. In the passive scan, the STA performing the scan waits for a beacon frame while the channel moves. The beacon frame is one of the management frames defined in IEEE 802.11, and is periodically transmitted to notify of the existence of a wireless network, and to 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 periodically transmit the beacon frame, and in the IBSS, the STAs within the IBSS rotate to transmit the beacon frame. When the STA performing the scan receives the beacon frame, the STA stores the information of 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 the scan in the next channel in the same manner. Comparing the active scan with the passive scan, the active scan has an advantage in that it has less delay and less power consumption than the passive scan.

[0067] After the STA discovers the network, an authentication process can be performed at step S320. In order to clearly distinguish from a security establishment operation of step S340 which will be described later, the authentication process can be referred to as a first authentication process.

[0068] The authentication process includes a process in which the STA transmits an authentication request frame to the AP, and in response thereto, the AP transmits an authentication response frame to the STA. The authentication frame for the authentication request / response corresponds to a management frame.

[0069] 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 finite cyclic group, and the like. This corresponds to some examples of information that can be included in an authentication request / response frame, and can be replaced with other information, or additional information can also be included.

[0070] The STA can transmit an authentication request frame to the AP. The AP can determine whether to allow authentication of the corresponding STA based on information included in the received authentication request frame. The AP can provide the result of the authentication process to the STA through an authentication response frame.

[0071] After the STA is successfully authenticated, an association process can be performed at step S330. The association process includes the following processing: the STA transmits an association request frame to the AP, and in response, the AP transmits an association response frame to the STA.

[0072] For example, the association request frame can include information related to various capabilities, a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, an RSN, a mobility domain, supported operating classes, a traffic indication map broadcast request (TIM broadcast request), interworking service capabilities, and the like. For example, the association response frame can include information related to various capabilities, a status code, an association ID (AID), supported rates, an enhanced distributed channel access (EDCA) parameter set, a received channel power indicator (RCPI), a received signal to noise indicator (RSNI), a mobility domain, a super interval (e.g., an association recovery time), an overlapping BSS scan parameter, a TIM broadcast response, a quality of service (QoS) map, and the like. This corresponds to some examples of information that can be included in an association request / response frame, and can be replaced with other information, or additional information can also be included.

[0073] After the STA is successfully associated with the network, a security establishment process can be performed at step S340. The security establishment process of step S340 can be referred to as an authentication process through a robust security network association (RSNA) request / response, the authentication process of step S320 is referred to as a first authentication process, and the security establishment process of step S340 can also be simply referred to as an authentication process.

[0074] The security establishment process of step S340 can include, for example, a process of establishing a private key through an extensible authentication protocol (EAPOL) frame over a LAN using a four-way handshake. In addition, the security establishment process can be performed according to a security scheme that is not defined in the IEEE 802.11 standard.

[0075] Figure 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0076] In a wireless LAN system, a basic access mechanism of a medium access control (MAC) is a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism. The CSMA / CA mechanism is also referred to as a distributed coordination function (DCF) of IEEE 802.11 MAC, and basically adopts a "listen before talk" access mechanism. According to this type of access mechanism, an AP and / or a STA can perform an explicit channel assessment (CCA) of sensing a wireless channel or medium during a predetermined time interval (e.g., a DCF interframe space (DIFS)) before starting transmission. As a result of sensing, if it is determined that the medium is in an idle state, a frame transmission is started by 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 can set a delay period (e.g., a random backoff period) for medium access and attempt frame transmission after waiting. By applying the random backoff period, since a plurality of STAs are expected to attempt frame transmission after waiting for different time periods, a collision can be minimized.

[0077] In addition, the IEEE 802.11 MAC protocol provides a hybrid coordination function (HCF). The HCF is based on the DCF and a point coordination function (PCF). The PCF is a polling-based synchronous access method, and refers to a method in which all receiving APs and / or STAs are periodically polled to receive data frames. In addition, the HCF has an enhanced distributed channel access (EDCA) and an HCF controlled channel access (HCCA). The EDCA is a contention-based access method that provides data frames to a plurality of users, and the HCCA uses a non-contention-based channel access method using a polling mechanism. In addition, the HCF includes a medium access mechanism for improving the QoS (quality of service) of a wireless LAN, and can transmit QoS data in a contention period (CP) and a contention free period (CFP).

[0078] Reference Figure 4An operation based on a random backoff period will be described. When the occupied / busy medium becomes an idle state, a plurality of STAs can attempt to transmit data (or frames). As a method of minimizing collisions, each of the STAs can respectively select a random backoff count, and attempt transmission after waiting for a corresponding slot time. The random backoff count has a pseudo-random integer value, and can be determined as one of values ranging from 0 to CW. Here, CW is a contention window parameter value. The CW parameter is given a CWmin as an initial value, but can take a value twice as large in the case of transmission failure (for example, when an ACK is not received for a transmitted frame). When the CW parameter value reaches CWmax, data transmission can 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,...).

[0079] When the random backoff process begins, the STA continuously monitors the medium according to the determined backoff count value for the backoff slot countdown. When the medium is monitored for occupation, it stops the countdown and waits, and when the medium becomes idle, it resumes the remaining portion of the countdown.

[0080] In the example of FIG. 3, Figure 4 When a packet to be transmitted arrives at the MAC of STA 3, STA 3 can transmit a frame immediately after confirming that the medium is idle for DIFS. The remaining STAs monitor and wait for the medium to be occupied / busy. Meanwhile, data to be transmitted can also occur in each of STA 1, STA 2, and STA 5, and when the medium is monitored to be idle, each STA waits for DIFS, and then can perform countdown of a backoff slot according to a random backoff count value selected by each STA. It is assumed that STA 2 selects the smallest backoff count value, and STA 1 selects the largest backoff count value. That is, a case is exemplified in which the remaining backoff time of STA 5 is shorter than that of STA 1 when STA 2 completes the backoff count and starts frame transmission. STA 1 and STA 5 temporarily stop the countdown, and wait while STA 2 occupies the medium. When the occupation of STA 2 ends and the medium becomes idle again, STA 1 and STA 5 wait for DIFS and resume the stopped backoff count. That is, frame transmission can start after countdown of the remaining backoff slot for the remaining backoff time. Since the remaining backoff time of STA 5 is shorter than that of STA 1, STA 5 starts frame transmission. Data to be transmitted can also occur in STA 4 while STA 2 occupies the medium. From the perspective of STA 4, when the medium becomes idle, STA 4 can wait for DIFS, and then can perform countdown according to a random backoff count value selected by STA 4, and start to transmit a frame. Figure 4The example illustrates a scenario where the remaining backoff time of STA5 accidentally conflicts 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 situation, STA4 and STA5 can double the CW value, select a random backoff count value, and begin a countdown. While the medium is occupied due to the transmissions of STA4 and STA5, STA1 waits; when the medium becomes idle, STA1 waits for DIFS, and then begins frame transmission after the remaining backoff time has elapsed.

[0081] As in Figure 4 In the example, data frames are frames used to send data forwarded to higher layers and can be sent after a backoff performed after DIFS (Distributed Access Frame) from the time the medium becomes idle. Additionally, management frames are frames used to exchange management information that has not been forwarded to higher layers and are sent after a backoff performed after an IFS (Information Support Function) such as DIFS or Point Coordination Function IFS (PIFS). Subtypes of management frames include beacons, association requests / responses, reassociation requests / responses, probe requests / responses, authentication requests / responses, etc. Control frames are frames used to control access to the medium. Subtypes of control frames include request-to-transmit (RTS), clear-to-transmit (CTS), acknowledgment (ACK), power-saving polling (PS-Poll), block ACK (BlockAck), block ACK request (BlockACKReq), null data packet advertisement (NDP advertisement), and triggers, etc. If the control frame is not a response frame to the previous frame, it is sent after backoff following the DIFS; if it is a response frame to the previous frame, it is sent without backoff following the Short IFS (SIFS). The type and subtype of a frame can be identified by the type field and subtype field in the Frame Control (FC) field.

[0082] The Quality of Service (QoS) ST can perform a backoff following the Arbitration IFS (AIFS) for the Access Class (AC) to which the frame belongs (i.e., AIFS where i is a value determined by the AC) before the frame can be transmitted. Here, the frame that can use AIFS can be a data frame, management frame, or control frame, rather than a response frame.

[0083] Figure 5 This is a diagram illustrating the CSMA / CA-based frame transmission operation that can be applied to this disclosure.

[0084] As described above, in addition to the physical carrier sensing in which the STA directly senses the medium, the CSMA / CA mechanism includes virtual carrier sensing. The virtual carrier sensing aims to compensate for problems that can occur in medium access such as the hidden node problem. For the virtual carrier sensing, the MAC of the STA can use a network allocation vector (NAV). The NAV is a value that indicates to other STAs the remaining time until the medium is available for use by the currently using or entitled STA. Thus, the value set to the NAV corresponds to the period in which the STA that transmits the frame plans to use the medium, and during the corresponding period, the STA that receives the NAV value is prohibited from accessing the medium. For example, the NAV can be configured based on the value of the "Duration" field of the MAC header of the frame.

[0085] In Figure 5 the example, it is assumed that STA1 intends to transmit data to STA2, and STA3 is in a position capable of overhearing some or all of the frames transmitted and received between STA1 and STA2.

[0086] To reduce the possibility of transmission collision of multiple STAs in the CSMA / CA-based frame transmission operation, a mechanism using RTS / CTS frames can be applied. In Figure 5 the example, when the transmission of STA1 is being performed, it can be determined that the medium is in an idle state as a result of the carrier sensing of STA3. That is, STA1 can correspond to a hidden node with respect to STA3. Alternatively, in Figure 5 the example, it can be determined that the medium is in an idle state as a result of the carrier sensing of STA3 when the transmission of STA2 is being performed. That is, STA2 can correspond to a hidden node with respect to STA3. By exchanging the RTS / CTS frames before the data transmission and reception between STA1 and STA2 are performed, the STA outside the transmission range of one of STA1 or STA2 or the STA outside the carrier sensing range of the transmission of STA1 or STA3 can not attempt to occupy the channel during the data transmission and reception between STA1 and STA2.

[0087] Specifically, STA1 can determine whether the channel is being used through carrier sensing. In terms of the 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 the virtual carrier sensing, STA1 can determine the channel occupancy state using a network allocation vector (NAV) timer.

[0088] When the channel is in an idle state during DIFS, STA1 can transmit an RTS frame to STA2 after performing backoff. When STA2 receives the RTS frame, STA2 can transmit a CTS frame to STA1 as a response to the RTS frame after SIFS.

[0089] If the STA 3 cannot overhear the CTS frame from the STA 2 but can overhear the RTS frame from the STA 1, the STA 3 can set the NAV timer for the frame transmission period (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame) thereafter using the duration information included in the RTS frame. Alternatively, if the STA 3 can overhear the CTS frame from the STA 2, the STA 3 can set the NAV timer for the frame transmission period (e.g., SIFS + data frame + SIFS + ACK frame) thereafter using the duration information included in the CTS frame, although the STA 3 cannot overhear the RTS frame from the STA 1. That is, if the STA 3 can overhear one or more of the RTS frame or the CTS frame from one or more of the STA 1 or the STA 2, the STA 3 can set the NAV accordingly. When the STA 3 receives a new frame before the NAV timer expires, the STA 3 can update the NAV timer using the duration information included in the new frame. The STA 3 does not attempt channel access until the NAV timer expires.

[0090] When the STA 1 receives the CTS frame from the STA 2, the STA 1 can transmit a data frame to the STA 2 after SIFS from the time point at which reception of the CTS frame is completed. When the STA 2 successfully receives the data frame, the STA 2 can transmit an ACK frame to the STA 1 after SIFS as a response to the data frame. When the NAV timer expires, the STA 3 can determine whether the channel is being used through carrier sensing. When the STA 3 determines that the channel is not being used by other terminals during DIFS after the NAV timer expires, the STA 3 can attempt channel access after a contention window (CW) according to random backoff has passed.

[0091] Figure 6 is a diagram for explaining an example of a frame structure used in a WLAN system to which the disclosure can be applied.

[0092] The PHY layer can prepare a MAC PDU (MPDU) to be transmitted by means of an instruction or primitive (meaning a set of instructions or parameters) from the MAC layer. For example, when a command requesting start of transmission of the PHY layer is received from the MAC layer, the PHY layer switches to a transmission mode, and configures information (e.g., data) provided from the MAC layer in the form of a frame and transmits it. In addition, when the PHY layer detects a valid preamble of a received frame, the PHY layer monitors a header of the preamble, and transmits a command informing start of reception of the PHY layer to the MAC layer.

[0093] In this manner, information transmission / reception in a wireless LAN system is performed in the form of a frame, and for this purpose, a PHY layer protocol data unit (PPDU) format is defined.

[0094] A basic PPDU can include a short training field (STF), a long training field (LTF), a signal (SIG) field, and a data (Data) field. The most basic PPDU format (e.g., non-HT (high throughput) as shown in FIG. 1A) can consist of only a legacy-STF (L-STF), a legacy-LTF (L-LTF), a legacy-SIG (L-SIG) field, and a data field. In addition, depending on the type of PPDU format (e.g., HT mixed format PPDU, HT greenfield format PPDU, VHT (very high throughput) PPDU, etc.), additional (or different types of) RL-SIG, U-SIG, non-legacy SIG fields, non-legacy STF, non-legacy LTF (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)) can be included between the L-SIG field and the data field. Figure 7

[0095] The STF is a signal for signal detection, automatic gain control (AGC), diversity selection, accurate time synchronization, etc., and the LTF is a signal for channel estimation and frequency error estimation. The STF and the LTF can be referred to as signals for synchronization and channel estimation of an OFDM physical layer.

[0096] The SIG field can include various information related to PPDU transmission and reception. For example, the L-SIG field consists of 24 bits, and the L-SIG field can include a 4-bit rate field, a 1-bit reserved bit, a 12-bit length field, a 1-bit parity check field, and a 6-bit tail field. The RATE field can include information about the modulation and coding rate of data. For example, the 12-bit length field can include information about the length or duration of the PPDU. For example, the value of the 12-bit length field can be determined based on the type of PPDU. For example, for non-HT, HT, VHT, or EHT PPDUs, the value of the length field can be determined as a multiple of 3. For example, for HE PPDUs, the value of the length field can be determined as a multiple of 3+1 or a multiple of 3+2.

[0097] ​The data field can include a service (SERVICE) field, a physical layer service data unit (PSDU), and a PPDU tail bit, and padding bits if necessary. Some bits of the service field can be used for synchronization of a descrambler at a receiving end. The PSDU corresponds to a MAC PDU defined in a MAC layer, and can include data generated / used in an upper layer. The PPDU tail bit can be used to return an encoder to a 0 state. The padding bits can be used to adjust the length of the data field by a predetermined unit.

[0098] The 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). The MAC frame can consist of a MAC PDU and be transmitted / received through a PSDU of a data part of a PPDU format.

[0099] The MAC header includes a frame control field, a duration / ID field, an address field, etc. The frame control field can include control information required for frame transmission / reception. The duration / ID field can be set to a time for transmitting a corresponding frame, etc. For details of sequence control, QoS control, and HT control subfields of the MAC header, refer to IEEE 802.11 standard documents.

[0100] The null data PPDU (NDP) format refers to a PPDU format that does not include a data field. In other words, the NDP refers to a frame format that includes a preamble (i.e., L-STF, L-LTF, L-SIG field, and additional non-legacy SIG, non-legacy STF, non-legacy LTF (if present)) of a general PPDU format and does not include a remaining part (i.e., a data field).

[0101] Figure 7 is a diagram illustrating an example of a PPDU defined in an IEEE 802.11 standard to which the disclosure can be applied.

[0102] In standards such as IEEE 802.11a / g / n / ac / ax, various types of PPDUs have been used. A basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and a data field. The basic PPDU format can also be referred to as a non-HT PPDU format (as Figure 7 indicated in (a) of FIG. 1).

[0103] The HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT fields, compared to the basic PPDU format. Figure 7The HT PPDU format shown in (b) of FIG. 1 can be referred to as the HT mixed format. In addition, an HT greenfield format PPDU can be defined, and this corresponds to a format (not shown) consisting of an HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs, and a data field, excluding the L-STF, L-LTF, and L-SIG.

[0104] An example of a VHT PPDU format (IEEE 802.11ac) additionally includes VHT-SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields (as shown in (c) of FIG. 1) compared to the basic PPDU format. Figure 7

[0105] An example of a HE PPDU format (IEEE 802.11ax) additionally includes a repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF, a packet extension (PE) field (as shown in (d) of FIG. 1) compared to the basic PPDU format. Some fields can be excluded, or their lengths can vary depending on detailed examples of the HE PPDU format. For example, the HE-SIG-B field is included in the HE PPDU format for multi-user (MU), and HE-SIG-B is not included in the HE PPDU format for single-user (SU). In addition, the HE trigger-based (TB) PPDU format does not include HE-SIG-B, and the length of the HE-STF field can vary to 8 µs. 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 can vary to 16 µs. For example, the RL-SIG can be configured to be the same as the L-SIG. Based on the presence of the RL-SIG, a receiving STA can know that the received PPDU is a HE PPDU or an EHT PPDU, which will be described later. Figure 7

[0106] An EHT PPDU format can include Figure 7 EHT MU (multi-user) in (e) of FIG. 1, and Figure 7 EHT TB (trigger-based) PPDU in (f) of FIG. 1. The EHT PPDU format is similar to the HE PPDU format in that it includes the RL-SIG following the L-SIG, but can include a U (universal)-SIG, EHT-SIG, EHT-STF, and EHT-LTF following the RL-SIG.

[0107] Figure 7 ​​The EHT MU PPDU in (e) corresponds to a PPDU carrying one or more data (or PSDU) for one or more users. That is, the EHT MU PPDU can be used for both SU transmission and MU transmission. For example, the EHT MU PPDU can correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0108] In comparison to the EHT MU PPDU, Figure 7 The EHT TB PPDU in (f) omits the EHT-SIG. A STA receiving a trigger (e.g., a trigger frame or a triggered response schedule (TRS)) for UL MU transmission can perform the UL transmission based on the EHT TB PPDU format.

[0109] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal Signal), EHT-SIG fields can be encoded and modulated such that even legacy STAs can attempt to demodulate and decode, and can be mapped based on the determined subcarrier frequency spacing (e.g., 312.5 kHz). These can be referred to as pre-EHT modulation fields. Next, the EHT-STF, EHT-LTF, data, PE fields can be encoded and modulated to be demodulated and decoded by STAs that successfully decoded the non-legacy SIG (e.g., U-SIG and / or EHT-SIG) and obtained the information included in the field, and can be mapped based on the determined subcarrier frequency spacing (e.g., 78.125 kHz). These can be referred to as EHT modulation fields.

[0110] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields can be referred to as pre-HE modulation fields, and the HE-STF, HE-LTF, data, and PE fields can be referred to as HE modulation fields. Additionally, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields can be referred to as non-VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and data fields can be referred to as VHT modulation fields.

[0111] The EHT-SIG field included in Figure 7The U-SIG in the EHT PPDU format can be configured based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG can have a duration of 4 μβ, and the U-SIG can have a total duration of 8 μβ. Each symbol of the U-SIG can be used to transmit 26 bits of information. For example, each symbol of the U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0112] The U-SIG can be constructed in units of 20 MHz. For example, if an 80 MHz PPDU is constructed, the U-SIG can be duplicated. That is, the same 4 U-SIGs can be included in the 80 MHz PPDU. A PPDU that exceeds the 80 MHz bandwidth can include different U-SIGs.

[0113] For example, A unencoded bits can be transmitted through the U-SIG, a first symbol (e.g., U-SIG-1 symbol) of the U-SIG can transmit a first X bits of information out of a total of A bits of information, and a second symbol (e.g., U-SIG-2 symbol) of the U-SIG can transmit a remaining Y bits of information out of the total of A bits of information. The A bits of information (e.g., 52 unencoded bits) can include a CRC field (e.g., 4-bit long field) and a tail field (e.g., 6-bit long field). For example, the tail field can be used to terminate a trellis structure of a convolutional decoder and can be set to 0.

[0114] The bits of information transmitted through the U-SIG can be divided into version-independent bits and version-dependent bits. For example, the U-SIG can be included in a new PPDU format (e.g., UHR PPDU format) not shown in Figure 7 The version-independent bits can be the same, and some or all of the version-dependent bits can be different, 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.

[0115] For example, the size of the version-independent bits of the U-SIG can be fixed or variable. The version-independent bits can be assigned to only the U-SIG-1 symbol, or to both the U-SIG-1 symbol and the U-SIG-2 symbol. The version-independent bits and the version-dependent bits can be referred to by various names, such as first control bits and second control bits.

[0116] For example, the version-independent bits of the U-SIG can include a 3-bit physical layer version identifier (PHY version identifier), and this information can indicate the PHY version (e.g., EHT, UHR, etc.) of the transmitted / received PPDU. The version-independent bits of the U-SIG can include a 1-bit UL / DL flag field. A first value of the 1-bit UL / DL flag field is related to UL communication, and a second value of the UL / DL flag field is related to DL communication. The version-independent bits of the U-SIG can include information on the length of a transmit opportunity (TXOP) and information on a BSS color ID.

[0117] For example, the version-dependent bits of the U-SIG can include information directly or indirectly indicating the type of the PPDU (e.g., SU PPDU, MU PPDU, TB PPDU, etc.).

[0118] Information required for PPDU transmission and reception can be included in the U-SIG. For example, the U-SIG can further include information on a bandwidth, information on an MCS technique applied to a non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.), information indicating whether a DCM (Dual Carrier Modulation) technique (e.g., a technique for achieving an effect similar to frequency diversity by reusing the same signal on two subcarriers) is applied to the non-legacy SIG, information on the number of symbols for the non-legacy SIG, information on whether the non-legacy SIG is generated across the entire frequency band.

[0119] Some of the information required for PPDU transmission and reception can be included in the U-SIG and / or the non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.). For example, information on the type of the non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information on the length of the non-legacy LTF and the CP (Cyclic Prefix) length, information on the GI (Guard Interval) applicable to the non-legacy LTF, information on the preamble puncturing applicable to the PPDU, information on the resource unit (RU) allocation, etc. can be included only in the U-SIG, only in the non-legacy SIG, or can be indicated by a combination of the information included in the U-SIG and the information included in the non-legacy SIG.

[0120] The preamble puncturing can denote transmission of a PPDU in which there is no signal in one or more frequency units among the bandwidth of the PPDU. For example, the size of the frequency unit (or the resolution of the preamble puncturing) can be defined as 20 MHz, 40 MHz, etc. For example, the preamble puncturing can be applied to a PPDU bandwidth of a predetermined size or more.

[0121] In Figure 7In an example of the HE-SIG-B and the EHT-SIG, a non-legacy SIG such as the HE-SIG-B and the EHT-SIG can include control information for a receiving STA. The non-legacy SIG can be transmitted over at least one symbol, and one symbol can have a length of 4 µs. Information about a number of symbols for the EHT-SIG can be included in a previous SIG (e.g., the HE-SIG-A, the U-SIG, etc.).

[0122] The non-legacy SIG such as the HE-SIG-B and the EHT-SIG can include a common field and a user-specific field. The common field and the user-specific field can be encoded separately.

[0123] In some cases, the common field can be omitted. For example, in a compressed mode applying non-OFDMA (orthogonal frequency division multiple access), the common field can be omitted, and multiple STAs can receive a PPDU (e.g., a data field of the PPDU) through the same frequency band. In a non-compressed mode applying OFDMA, multiple users can receive a PPDU (e.g., a data field of the PPDU) through different frequency bands.

[0124] A number of user-specific fields can be determined based on a number of users. One user block field can include up to two user fields. Each user field can be associated with a MU-MIMO allocation, or can be associated with a non-MU-MIMO allocation.

[0125] The common field can include a CRC bit and a tail bit, and a length of the CRC bit can be determined as 4 bits, and a length of the tail bit can be determined as 6 bits and set as 000000. The common field can include RU allocation information. The RU allocation information can include information about locations of RUs to which a plurality of users (i.e., a plurality of receiving STAs) are assigned.

[0126] An RU can include a plurality of subcarriers (or tones). The RU can be used when a signal is transmitted to a plurality of STAs based on an OFDMA technology. In addition, the RU can be defined even when a signal is transmitted to one STA. A non-legacy STF, a non-legacy LTF, and a data field can be allocated resources in units of the RU.

[0127] An RU of an applicable size can be defined according to a PPDU bandwidth. An RU can be defined identically or differently for an applied PPDU format (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.). For example, in the case of an 80 MHz PPDU, the RU layout of an HE PPDU and an EHT PPDU can be different. The applicable RU size per PPDU bandwidth, the number and location of RUs, the location and number of DC (direct current) subcarriers, the location and number of null subcarriers, the location and number of guard subcarriers, etc. can be referred to as a tone plan. For example, a tone plan for a high bandwidth can be defined in the form of multiple iterations of a low bandwidth tone plan.

[0128] RUs of various sizes can be defined as 26-tone RUs, 52-tone RUs, 106-tone RUs, 242-tone RUs, 484-tone RUs, 996-tone RUs, 2x996-tone RUs, 3x996-tone RUs, etc. An MRU (multi-RU) is different from a plurality of individual RUs and corresponds to a group of subcarriers consisting of a plurality of RUs. For example, one MRU can be defined as 52+26 tones, 106+26 tones, 484+242 tones, 996+484 tones, 996+484+242 tones, 2x996+484 tones, 3x996 tones, or 3x996+484 tones. In addition, the plurality of RUs constituting one MRU can be continuous or can not be continuous in the frequency domain.

[0129] A specific size of an RU can be reduced or expanded. Accordingly, the specific size of each RU in the disclosure (i.e., the number of corresponding tones) is not restrictive but illustrative. In addition, in the disclosure, the number of RUs can vary according to the RU size within a predetermined bandwidth (e.g., 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz,...).

[0130] Figure 7 The names of each field in the PPDU format of are exemplary, and the scope of the disclosure is not limited by the names. In addition, examples of the disclosure can be applied to the PPDU format shown in and a new PPDU format that excludes some fields and / or adds some fields based on the PPDU format of Figure 7 . Quality of Service characteristics element

[0131] Figure 8

[0132] ​The QoS characteristics element defined in the wireless LAN system includes a set of parameters that define characteristics of a traffic stream and QoS expectations. In this regard, the QoS characteristics element is used by the EHT AP and non-AP EHT STAs for supporting QoS traffic transmission using the Stream Classification Service (SCS) procedure and the Restricted TWT procedure, in the case of a specific non-AP EHT STA.

[0133] Flow Classification Service procedure A QoS characteristics element applicable to the embodiments of the present disclosure is exemplified.

[0134] Specifically, the control information field includes a Direction subfield, a Traffic ID (TID) subfield, a User Priority (UP) subfield, a presence bitmap subfield of additional parameters, a Link ID subfield, and a reserved bit (e.g., 3 bits).

[0135] The Direction subfield specifies the direction of data described by the corresponding element and indicates uplink, downlink, direct link, or reserved. Here, the uplink refers to transmitting MSDU or A-MSDU from a non-AP STA to an AP, the downlink refers to transmitting MSDU or A-MSDU from an AP to a non-AP STA, and the direct link refers to transmitting MSDU or A-MSDU through a P2P (peer-to-peer) link.

[0136] The TID subfield contains the TID value of the data frame described by the element. The TID subfield is set to the same value as the UP subfield. Here, the values 8 to 15 of the TID subfield are reserved. In this regard, the presence of the TID subfield can be for future extension to allow transmission of TID values independent of the User Priority (UP).

[0137] The UP subfield contains the UP value (one of 0 to 7) of the data frame described by the element. If the Traffic Classification (TCLAS) element is present in the SCS request frame including the element, the UP subfield is set to the UP value specified in the TCLAS element.

[0138] The presence bitmap subfield of additional parameters contains a bitmap, and the i-th item of the bitmap is set to 1 if the i-th field from the Maximum MSDU Size field is present in the element. For each field from the Maximum MSDU Size field, the value 0 is reserved.

[0139] The Link ID subfield contains a link identifier corresponding to the link on which direct link transmission will be made. If the Direction subfield is equal to any value other than indicating direct link, the subfield is reserved.

[0140] The minimum service interval field contains an unsigned integer that specifies the minimum interval (e.g., in milliseconds (ms)) between two consecutive SPs (service periods, scheduling periods) allocated with frame exchanges (e.g., UL / DL / direct link based frame exchanges). The maximum service interval field contains an unsigned integer that specifies the maximum interval (e.g., in ms) between two consecutive SPs (service periods, scheduling periods) allocated with frame exchanges (e.g., UL / DL / direct link based frame exchanges). In this regard, the value of the maximum service interval field is greater than or equal to the value of the minimum service interval field.

[0141] The minimum data rate field contains an unsigned integer that specifies the minimum data rate (e.g., kilobits per second) specified in the MAC SAP for transmitting MSDUs or A-MSDUs belonging to the traffic stream described by this element.

[0142] The delay limit field contains an unsigned integer that specifies the maximum time (in microseconds) allowed for transmitting MSDUs or A-MSDUs belonging to the traffic stream described by this element.

[0143] The maximum MSDU size field contains an unsigned integer that specifies the maximum size (in octets) of MSDUs or A-MSDUs belonging to the traffic stream described by this element.

[0144] The service start time field contains an unsigned integer that specifies the expected time (e.g., in microseconds) for the start of traffic for the associated TID. Here, the service start time indicates to the AP the time at which the STA expects to exchange frames corresponding to the TID specified in this element. This field indicates the low four octets of the TSF timer associated with the link specified in the link ID field at the expected start of the SP.

[0145] The four least significant bits (LSBs) of the service start time link ID field indicate the link identifier corresponding to the link for which the TSF timer used to indicate the service start time. The four most significant bits (MSBs) are reserved. This field is present only if the service start time field is present.

[0146] The average data rate field indicates the average data rate (e.g., in kilobits per second) specified in the MAC SAP for transmitting MSDUs or A-MSDUs belonging to the traffic stream within the bounds of this element.

[0147] The burst size field is 4 octets in length and contains an unsigned integer that specifies the maximum burst (i.e., in octets) of MSDUs or A-MSDUs belonging to the traffic stream that arrives at the MAC SAP within the time specified in the delay limit field.

[0148] The MSDU lifetime field contains an unsigned integer that specifies the maximum time (in milliseconds) after which the MSDU can become unusable at the MAC data service interface even though the MSDU has been received by the receiver. Thus, the MSDU transmitter can consider discarding such MSDU at the transmitter before transmitting over the air. The time specified in this field is greater than or equal to the time specified in the delay limit field (if present).

[0149] The MSDU delivery information field contains MSDU delivery information. The MSDU delivery information field contains an MSDU delivery ratio subfield and an MSDU count exponent subfield. Here, the MSDU delivery ratio subfield specifies the MSDU loss requirement (e.g., 95% to 99.9999%). The MSDU count exponent subfield contains an unsigned integer that specifies the exponent used to calculate the number of MSDUs received for calculating the MSDU delivery ratio. In this case, the number of MSDUs received is equal to 10 raised to the power of the MSDU count exponent. If the delay limit is not specified, the MSDU delivery information subfield is not present.

[0150] Figure 9

[0151] The present disclosure relates to a method of indicating a link of low latency traffic based on an SCS procedure.

[0152] The SCS procedure (i.e., SCS negotiation procedure) can be performed based on the exchange of an SCS request frame and an SCS response frame.

[0153] For example, the STA can transmit an SCS descriptor element including flow classification related information and / or transmission requirements of low latency traffic to the AP in the SCS request frame. At this time, there can be one or more SCS descriptor elements in the frame, and each SCS descriptor element can be distinguished by an SCS ID. The AP can transmit an SCS response frame including a status code and / or an SCS descriptor element for the received SCS ID to the STA, through which the SCS negotiation can be completed.

[0154] In particular, when SCS is utilized, a classification can be established that uses Layer 2 and / or Layer 3 signaling to match individually addressed MSDUs. Once classified, individually addressed MSDUs that match the classification are assigned an Access Category (AC) and are tagged with a Drop Eligibility Tag. When Intra-Access Category Priority is enabled, SCS enables finer priority differentiation by assigning MSDUs that match the classification to either a primary Enhanced Distributed Channel Access (EDCA) transmission queue or an alternate Enhanced Distributed Channel Access (EDCA) transmission queue.

[0155] In particular, the SCS Request frame is used to request the creation, modification, and / or deletion of a flow classification using procedures defined in the SCS procedure. Here, the Action field format of the SCS Request frame can include a 1-octet Category field, a 1-octet Robust Action field, a 1-octet Conversation Token field, and / or a variable SCS Descriptor List field that includes one or more SCS Descriptor elements.

[0156] The SCS Response frame is sent in response to a SCS Request frame using procedures defined in the SCS procedure. Here, the Action field format of the SCS Response frame can include a 1-octet Category field, a 1-octet Robust Action field, a 1-octet Conversation Token field, a variable SCS Status List field that includes one or more SCS Status tuples, and / or a variable SCS Descriptor List field that includes one or more SCS Descriptor elements.

[0157] Here, the SCS Status tuple format can include a SCS ID field that indicates a SCS flow and a Status field that indicates the status (i.e., status code) of the corresponding SCS flow.

[0158] Additionally, with respect to the SCS Response frame, the SCS Descriptor List can optionally be present when the SCS Response frame is sent from a STA affiliated with a Multi-Link Device (MLD) to a STA affiliated with another MLD. If present, it can include zero or more SCS Descriptor elements. Here, each SCS Descriptor element can include a QoS Profile element that describes the traffic profile and QoS expectations of the traffic stream belonging to the corresponding SCS flow identified by the SCS ID field value of the same SCS Descriptor element. In particular, if the status code field value of the corresponding SCS ID is “success” or “rejected with suggested changes”, zero or one SCS Descriptor element can be included in the SCS Status List field, otherwise no SCS Descriptor element can be present.

[0159] The SCS Descriptor element that can be included in the above SCS Request / Response frames defines information about a flow classified using the SCS procedure, and can be configured as follows:Figure 9 are shown.

[0160] Figure 9 SCS descriptor elements that can be applied to embodiments of the present disclosure are illustrated.

[0161] Referring to Figure 8 , the SCS descriptor element can include an element ID field, a length field, an SCS ID field, a request type field, an access category intra-priority element field (optional), a traffic classification (TCLAS) element field (optional), a TCLAS handling element field (optional), a QoS characteristics element field (optional) (e.g., see QoS Characteristics Element of Method to indicate links for low latency traffic based on SCS procedure ), an optional sub-element field, etc.

[0162] Here, the SCS ID field is set to a non-zero value selected by a non-AP STA to identify an SCS stream specified in the corresponding SCS descriptor element.

[0163] The request type field is set to a value to identify the type of SCS request. As a specific example, a value of 0 indicates "add", a value of 1 indicates "remove", a value of 2 indicates "change", and values of 3 to 255 are reserved. When the request type field is "add" or "change", the access category intra-priority element field exists.

[0164] The TCLAS element field includes zero or more TCLAS elements that specify a method of classifying a received MSDU as part of a corresponding SCS stream. When the request type field is "add" or "change", one or more TCLAS elements exist, and when the request type field is "remove", no TCLAS element exists. When two or more TCLAS elements exist in the TCLAS element field, the TCLAS handling element field exists, and the TCLAS handling element field contains a TCLAS handling element that defines how the plurality of TCLAS elements will be handled.

[0165] Embodiment 1

[0166] The present disclosure relates to a method for indicating / configuring information of one or more links for transmitting / receiving low latency traffic / data within an SCS procedure.

[0167] Referring to the existing SCS procedure and QoS Characteristics element (e.g., IEEE 802.11 / 802.11be, etc.), for information about a link through which low latency traffic / data is transmitted / received within an SCS request / response frame, only a link ID subfield exists in the control field of the QoS Characteristics element.

[0168] However, as described above, the link ID subfield is defined to indicate a link ID of a link through which low latency traffic is transmitted and received when the value of the direction subfield in the control field of the same QoS profile element is direct link (i.e., peer-to-peer (P2P)). Here, the length of the link ID subfield is 4 bits, and one link can be indicated.

[0169] In consideration of this, the existing link ID subfield can be extended and defined to indicate information (e.g., a link ID, etc.) of a link through which low latency traffic is transmitted and received based on an uplink (UL) direction and / or a downlink (DL) direction. However, even in this case, there is a limitation that only one link can be indicated.

[0170] Accordingly, the disclosure proposes an SCS negotiation procedure, i.e., a method for indicating one or more links through which low latency traffic / data is transmitted and received within an SCS request / response frame, by specific examples.

[0171] Specifically, information related to a link can be defined / utilized within an SCS request / response frame based on one or more embodiments described below.

[0172] The values / names described in the embodiments of the disclosure do not limit the scope of the disclosure, and can be changed / replaced with other values / names, etc. Additionally, in the embodiments of the disclosure, the STA can include a non-AP STA and an AP STA.

[0173] Figure 10

[0174] The present embodiment relates to a method of indicating information of a link for transmitting and receiving low latency traffic / data by including a link information element indicating one or more links in an SCS request / response frame.

[0175] The link information element can be defined to include bitmap information (i.e., link ID bitmap information) for indicating one or more link IDs.

[0176] For example, the link information element can be configured based on a multi-link operation (MLO) link information element format as in Figure 10 In the present embodiment, the structure of the link information element is described using the MLO link information element format as an example, but the scope of the disclosure is not limited thereto, and can be replaced / extended based on another information element format including bitmap information for indicating a link ID.

[0177] Figure 10 An MLO link information element according to an embodiment of the disclosure is exemplified.

[0178] Referring to Figure 9 , the MLO link information element format can include an element ID field, a length field, an element ID extension field, and a link ID bitmap field.

[0179] The MLO link information element is defined as information indicating a link on which a STA within an MLD is to operate to transmit and receive messages to and from a peer / counterpart MLD. In this regard, the STA can share information of a link to operate with the peer / counterpart MLD by setting a value 1 in a bit corresponding to a link ID in the link ID bitmap field.

[0180] Specifically, to indicate information of a link for transmitting and receiving low latency traffic / data, the link information element proposed in the disclosure can be included in an SCS descriptor element within an SCS request / response frame (see, for example, the SCS descriptor element of Figure 11 ).

[0181] Figure 11 An SCS descriptor element including a link information element according to an embodiment of the disclosure is exemplified.

[0182] Referring to Figure 11 , the link information element can be included in an SCS descriptor element within an SCS request / response frame, and can be defined to indicate one or more links associated with traffic / data based on the SCS descriptor element.

[0183] Although the link information element is exemplified as being located after the QoS characteristics element in Figure 11 , the position at which the link information element is added within the SCS descriptor element is not limited to the example of Embodiment 2 . Additionally, the link information element can be defined to be optionally included only when one or more links need to be indicated, and can be defined to have a length of 0 to 5 octets.

[0184] For example, the link information element included in the SCS descriptor element within the SCS request / response frame can indicate one or more links that support transmission and reception of traffic / data having characteristics indicated by the access category within priority element, the TCLAS element, and / or the QoS characteristics element.

[0185] As a specific example, when the corresponding QoS characteristics element and the link information element are included together in the SCS descriptor element, this can mean indicating / containing information about a link that supports transmission and reception of low latency traffic / data.

[0186] The existing MLO link information element (e.g., MLO link information element defined in IEEE 802.11be standard) is defined to have a value 1 for only one link. For example, when there are three links (e.g., link 1, link 2, and link 3), when link 1 cannot transmit a message on behalf of link 3, the link information element can be used to indicate which link to transmit the message on behalf of. As a specific example, when link 3 is "busy" or in a sleep state of a power saving (PS) mode, link 1 can transmit a target wake time (TWT) frame on behalf. In this case, the link ID bitmap in the MLO link information element is set to indicate link 3 and is transmitted, and the STA receiving the MLO link information element can recognize that the corresponding TWT frame is a TWT frame of link 3.

[0187] In contrast, the link information element (e.g., MLO link information element) in the SCS request / response frame in the present disclosure is different in that it is defined to have a value 1 for one or more links (i.e., one or more of the plurality of bits constituting bitmap information can be set to a value 1). That is, the existing SCS procedure does not separately set / indicate a link in terms of being applied to an MLD level, that is, it is commonly applied to all links belonging to the corresponding MLD. On the other hand, in the case of the method proposed in the present disclosure, since the link level can be indicated even in the SCS procedure, there is a technical effect that efficient low-latency traffic / data transmission and reception can be performed through flexible / adaptive link utilization.

[0188] Figure 12

[0189] The present embodiment relates to a method of indicating information of a link for transmitting and receiving low-latency traffic / data by including a field indicating one or more links in a QoS characteristics element in an SCS request / response frame.

[0190] Figure 12 A QoS characteristics element including a link ID bitmap field according to an embodiment of the present disclosure is exemplified.

[0191] Reference Figure 12 A field can be newly added / defined in the QoS characteristics element includable in the SCS descriptor element within the SCS request / response frame to indicate one or more links.

[0192] Here, the new field can be referred to as a link ID bitmap field, and one or more bits constituting bitmap information can be used to indicate whether the operation of the corresponding link is supported. That is, setting the value of the corresponding bit to "1" can mean that the link of the link ID corresponding to the corresponding bit supports the operation.

[0193] InFigure 12 In this case, it is assumed that the position of the Link ID bitmap field is after the delay limit field in the QoS capability element, but the position is not limited to this example.

[0194] Additionally, although the length of the Link ID bitmap field is exemplified as 2 octets (i.e., 16 bits) in Figure 13 In this case, it is assumed that the position of the Link ID bitmap field is after the delay limit field in the QoS capability element, but the position is not limited to this example.

[0195] The method of newly adding the Link ID bitmap field to the QoS capability element of the present embodiment can affect the size of the QoS capability element. However, the method of the present embodiment can have a smaller overhead than the method of adding the link information element (e.g., the MLO link information element / field of 5 octets long) described in the previous embodiment (i.e., Embodiment 1).

[0196] Regarding the embodiments of the present disclosure, the methods have been described with representative examples applied to low latency traffic, but it is not excluded that the methods can be extended and applied to other types of traffic.

[0197] Hereinafter, the operation of the STA according to the above-described embodiments of the present disclosure will be described with reference to Figure 14 and Figure 13

[0198] That is, the examples of Figure 14 and Figure 13 may correspond to some of various examples of the present disclosure. For example, in Figure 14 and Figure 13 , the first STA can correspond to a non-AP STA, and the second STA can correspond to an AP.

[0199] Figure 13 An operation flow diagram of the first STA according to the embodiments of the present disclosure is exemplified.

[0200] Referring to Figure 11 , the first STA can transmit an SCS request frame including information related to negotiation of a specific type of traffic to the second STA (S1310).

[0201] For example, the specific type of traffic can correspond to low latency traffic transmitted and received between the first STA and the second STA.

[0202] In this regard, the specific type of traffic can be based on uplink traffic or downlink traffic between the first STA and the second STA. Additionally or alternatively, the specific type of traffic can correspond to traffic for direct link transmission (e.g., P2P transmission) between the first STA and the second STA. ​

[0203] Thereafter, the first STA can receive, from the second STA, an SCS response frame in response to the SCS request frame (S1320).

[0204] In this regard, at least one of the SCS request frame or the SCS response frame can include link-related information indicating one or more links through which the specific type of traffic is to be transmitted and received.

[0205] For example, the link-related information can be defined based on a bitmap format composed of one or more bits for indicating whether the one or more links are supported. In this regard, the one or more bits can be mapped to different link identifiers (link IDs).

[0206] In this regard, the link-related information can be defined to be included in the SCS descriptor element in the form of an information element format (e.g., see Figure 12 ). For example, the specific type of traffic corresponds to traffic based on one or more information elements in the SCS descriptor element, and the one or more information elements can include at least one of an Access Category Intra- Priority element, a Traffic Class (TCLAS) element, or a QoS Characteristics element. In this case, the link-related information can be defined to be located after the QoS Characteristics element in the SCS descriptor element.

[0207] Additionally or alternatively, the link-related information can be defined to be included in the QoS Characteristics element in the form of a field format (e.g., see Figure 13 ). For example, the link-related information can be defined to be located after a delay limit field in the QoS Characteristics element.

[0208] The method performed by the first STA described in the examples of Figure 1 may be performed by the first apparatus (100) of Figure 1 . For example, the one or more processors (102) of the first apparatus (100) of Figure 13 may be configured to transmit, via the one or more transceivers (106), an SCS request frame to a second STA (200) and receive, from the second STA (200), an SCS response frame for an indication of link-related information indicating one or more links through which a specific type of traffic is to be transmitted and received. Further, the one or more memories (104) of the first apparatus (100) can store instructions that, when executed by the one or more processors (102), cause the method described in the examples of Figure 14 or the above examples to be performed.

[0209] Figure 14An operation flowchart of a second STA according to an embodiment of the disclosure is illustrated.

[0210] Referring to Figure 14 , the second STA can receive, from the first STA, an SCS request frame including information related to negotiation of a specific type of traffic (S1410).

[0211] Since the content of the specific type of traffic in Figure 13 overlaps with the content described in Figure 14 , a detailed description thereof is omitted.

[0212] Thereafter, the second STA can transmit, to the first STA, an SCS response frame in response to the SCS request frame (S1420).

[0213] In this regard, at least one of the SCS request frame or the SCS response frame can include link-related information indicating one or more links through which the specific type of traffic is to be transmitted and received.

[0214] Figure 13 The content of the SCS request frame, the SCS response frame, and the link-related information in Figure 14 overlaps with the content described in , a detailed description thereof is omitted.

[0215] In the example of Figure 1 , the method performed by the second STA can be performed by the second apparatus (200) of Figure 1 . For example, one or more processors (202) of the second apparatus (200) of Figure 14 may be configured to receive, from the first STA (100), an SCS request frame and transmit, to the first STA (100), an SCS response frame via one or more transceivers (206) for an indication of link-related information indicating one or more links through which a specific type of traffic is to be transmitted and received. Further, one or more memories (204) of the second apparatus (200) can store instructions that, when executed by the one or more processors (202), cause the method described in the example of ​ or the above-described example to be performed.

[0216] In the existing wireless LAN system, the link information in the SCS procedure is related only to a direct link between STAs (e.g., P2P operation), and can indicate only one link. In contrast, the method proposed in the disclosure can indicate one or more links for each traffic negotiated in the SCS procedure, and can be implemented as a new effect indicating link information for uplink (UL) and / or downlink (DL) based traffic.

[0217] The above-described embodiments are combinations of elements and features of the present disclosure in a predetermined form. Each of the individual elements or features should be considered optional unless explicitly mentioned otherwise. Each of the individual elements or features can be implemented in a form not combined with other elements or features. Also, embodiments of the present disclosure can include combinations of some elements and / or features. The order of the operations described in embodiments of the present disclosure can be changed. Some elements or features of one embodiment can be included in other embodiments, or can be substituted with corresponding elements or features of other embodiments. It is obvious that embodiments can include claims not explicitly cited, or can be included as new claims by amendment after the application.

[0218] It will be obvious to those skilled in the relevant arts that the present disclosure can be implemented in other specific forms without departing from the essential characteristics of the present disclosure. Therefore, the above detailed description should not be construed as being limited in all respects, but should be considered as being illustrative. The scope of the present disclosure should be determined by reasonable interpretation of the appended claims, and variations within the scope of the present disclosure are included in the scope of the present disclosure.

[0219] The scope of the present disclosure includes software or machine-executable commands (e.g., operating systems, applications, firmware, programs, etc.) that perform operations according to the methods of various embodiments in an apparatus or computer, and non-transitory computer-readable media that cause the software or commands, etc. to be stored and executable in the apparatus or computer. Commands that can be used to program processing systems to perform features described in the present disclosure can be stored in storage media or computer-readable storage media, and features described in the present disclosure can be implemented using computer program products including such storage media. The storage media can include 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 can include non-volatile memory such as one or more 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 remotely from the processor. The memory, or alternatively the non-volatile memory devices in the memory, includes non-transitory computer-readable storage media. Features described in the present disclosure can be stored in any one of machine-readable media to control the hardware of the processing system, and can be integrated into software and / or firmware that allows the processing system to interact with other mechanisms using results from embodiments of the present disclosure. Such software or firmware can include application code, device drivers, operating systems, and execution environments / containers, but is not limited thereto.

[0220] Industrial applicability

[0221] The method proposed by the present disclosure is mainly described based on an example applied to an IEEE 802.11 based system, but can be applied to various WLAN or wireless communication systems other than the IEEE 802.11 based system.

Claims

1. A method performed by a first station (STA) in a wireless LAN system, the method comprising: transmitting, to a second STA, a stream classification service (SCS) request frame including information related to negotiation of a specific type of traffic; and receiving, from the second STA, a SCS response frame in response to the SCS request frame, wherein at least one of the SCS request frame or the SCS response frame includes link-related information indicating one or more links through which the specific type of traffic is to be transmitted and received. 2.The method of claim 1, wherein, wherein the link-related information is defined based on a bitmap format including one or more bits for indicating whether the one or more links are supported. 3.The method of claim 2, wherein wherein the one or more bits are mapped to different link identifiers (link IDs). 4.The method of claim 1, wherein, wherein the specific type of traffic is based on uplink traffic or downlink traffic between the first STA and the second STA. 5.The method of claim 1, wherein wherein the specific type of traffic corresponds to low latency traffic transmitted and received between the first STA and the second STA. 6.The method of claim 1, wherein wherein the link-related information is defined to be included in the SCS descriptor element in an information element format. 7.The method of claim 6, wherein wherein the specific type of traffic corresponds to traffic based on one or more information elements in the SCS descriptor element, and wherein the one or more information elements include at least one of an access category in-priority element, a traffic classification (TCLAS) element, or a QoS characteristics element. 8.The method of claim 6, wherein wherein the link-related information is defined to be located after the QoS characteristics element in the SCS descriptor element. 9.The method of claim 1, wherein, wherein the link-related information is defined to be included in the QoS characteristics element in a field format. 10.The method of claim 9, wherein wherein the link-related information is defined to be located after a delay limit field in the QoS characteristics element. 11.The method of claim 1, wherein, wherein the first STA corresponds to a non-access point (non-AP) STA, and the second STA corresponds to an AP. 12.An apparatus for a first station (STA) in a wireless local area network (WLAN) system, the apparatus comprising: at least one transceiver; and at least one processor connected to the at least one transceiver, wherein the at least one processor is configured to: transmit, to a second STA, a stream classification service (SCS) request frame including information related to negotiation of a specific type of traffic; and receive, from the second STA, a SCS response frame in response to the SCS request frame, ​ wherein at least one of the SCS request frame or the SCS response frame includes link-related information indicating one or more links through which the specific type of traffic is to be transmitted and received.

13. A method performed by a second station (STA) in a wireless LAN system, the method comprising: receiving, from a first STA, a stream classification service (SCS) request frame including information related to negotiation of a specific type of traffic; and transmitting, to the first STA, a SCS response frame in response to the SCS request frame, wherein at least one of the SCS request frame or the SCS response frame includes link-related information indicating one or more links through which the specific type of traffic is to be transmitted and received.

14. An apparatus for a first station (STA) in a wireless local area network (WLAN) system, the apparatus comprising: at least one transceiver; and at least one processor connected to the at least one transceiver, wherein the at least one processor is configured to: receive, from a first STA, a stream classification service (SCS) request frame including information related to negotiation of a specific type of traffic; and transmit, to the first STA, a SCS response frame in response to the SCS request frame, wherein at least one of the SCS request frame or the SCS response frame includes link-related information indicating one or more links through which the specific type of traffic is to be transmitted and received.

15. 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; and at least one computer memory operably connectable to the at least one processor and storing instructions based on being executed by the at least one processor to perform a method according to any one of claims 1 to 11.

16. At least one non-transitory computer-readable medium storing at least one instruction, wherein: the at least one instruction, when executed by at least one processor, controls an apparatus to perform a method according to any one of claims 1 to 11 in a wireless local area network (WLAN) system.

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