Method and apparatus for transmitting or receiving based on flexible user priority-to-access category mapping in wireless LAN system

Abstract

Disclosed are a method and an apparatus for transmitting or receiving on the basis of a flexible User Priority (UP)-to-Access Class (AC) mapping in a wireless LAN system. A method performed by a station (STA) in a wireless LAN system according to an embodiment of the present disclosure may comprise the steps of: transmitting, to an access point (AP), a request including information associated with a first user priority-to-access category (UP-to-AC) mapping; receiving, from the AP, a response including one or more of information associated with the second UP-to-AC mapping and whether the information associated with the first UP-to-AC mapping is accepted; and performing a frame exchange with the AP based on the information associated with the first UP-to-AC mapping or the information associated with the second UP-to-AC mapping.

Description

Technical Field

[0001] The present disclosure relates to a transmission or reception method and apparatus based on flexible User Priority (UP)-to-Access Category (AC) mapping in a Wireless Local Area Network (WLAN) system. Background Art

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

[0003] 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 utilization of multiple frequency bands, and increased spatial streams are being studied. Specifically, various technologies are being studied to support low-latency or real-time traffic. Furthermore, new technologies are being discussed to support Ultra-High Reliability (UHR), including improvements or extensions to EHT technologies. Summary of the Invention

[0004] Technical issues

[0005] The technical problem of the present disclosure is to provide a method and apparatus for supporting flexible user priority-to-access category UP-to-AC mapping in a WLAN system.

[0006] An additional technical problem of the present disclosure is to provide a method and apparatus for performing fast transmission or reception of low-latency (LL) traffic based on flexible UP-to-AC in a WLAN system.

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

[0008] Technical Solution

[0009] A method performed by a station (STA) in a WLAN system according to an aspect of the present disclosure may include: sending a request including information related to a first user priority-to-access category (UP-to-AC) mapping to an access point (AP); receiving a response including at least one of information related to a second UP-to-AC mapping or whether the information related to the first UP-to-AC mapping is accepted from the AP; and performing frame exchange with the AP based on the information related to the first UP-to-AC mapping or the information related to the second UP-to-AC mapping.

[0010] A method performed by an access point (AP) in a WLAN system according to additional aspects of the present disclosure may include: receiving a request including information related to a first user priority-to-access category (UP-to-AC) mapping from a station (STA); sending a response including at least one of information related to a second UP-to-AC mapping or whether the information related to the first UP-to-AC mapping is accepted to the STA; and performing frame exchange with the STA based on the information related to the first UP-to-AC mapping or the information related to the second UP-to-AC mapping.

[0011] Technical Effects

[0012] According to the present disclosure, a method and apparatus for supporting flexible user priority-to-access category UP-to-AC mapping in a WLAN system may be provided.

[0013] According to the present disclosure, a method and apparatus for performing fast transmission or reception of low-latency (LL) traffic based on flexible UP-to-AC in a WLAN system may be provided.

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

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

[0016] Figure 1 A block diagram illustrating a configuration 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 This is a diagram for explaining a link establishment process to which the present disclosure can be applied.

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

[0020] Figure 5 This is a diagram for explaining a frame transmission operation based on CSMA / CA 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 the IEEE 802.11 standard to which the present disclosure can be applied.

[0023] Figure 8 is a diagram for explaining an example of a FUTA-based operation of an STA according to the present disclosure.

[0024] Figure 9 is a diagram for explaining an example of a FUTA-based operation of an AP according to the present disclosure.

[0025] Figure 10 and Figure 11 is a diagram illustrating an example of information indicating UP-to-AC mapping according to the present disclosure.

[0026] Figure 12 An example of the EDCA parameter set information element format according to the present disclosure is shown.

[0027] Figure 13 and Figure 14 is a diagram for explaining an example of operations of an AP and a STA for applying FUTA according to the present disclosure.

[0028] Figure 15 is a diagram illustrating an example of traffic transmission based on FUTA mapping according to the present disclosure. DETAILED DESCRIPTION

[0029] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed with the accompanying drawings is intended to describe exemplary embodiments of the present disclosure and is not intended to represent the only embodiment in which the present disclosure may be implemented. The following detailed description includes specific details to provide a complete understanding of the present disclosure. However, those skilled in the relevant art will appreciate that the present disclosure may be implemented without these specific details.

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

[0031] In the present disclosure, when an element is referred to as being "connected," "combined," or "linked" to another element, it may include an indirect connection relationship in which another element exists therebetween as well as a direct connection relationship. In addition, in the present disclosure, the terms "comprising" or "having" specify the presence of the mentioned features, steps, operations, components, and / or elements, but do not preclude the presence or addition of one or more other features, steps, operations, components, elements, and / or groups thereof.

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

[0033] The terms used in this disclosure are intended to describe specific embodiments and not to limit the claims. As used in the description of the embodiments and the appended claims, the singular is intended to include the plural, unless the context clearly indicates otherwise. The term "and / or" used in this disclosure may refer to one of the relevant enumerated items, or mean that it refers to and includes any and all possible combinations of two or more of them. In addition, unless otherwise indicated, the " / " between words in this disclosure has the same meaning as "and / or".

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

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

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

[0037] Figure 1 The first device 100 and the second device 200 illustrated in the specification may 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 a simple user. In addition, the first device 100 and the second device 200 include an access point (AP), a base station (BS), a fixed station, a node B, a base transceiver system (BTS), and a network. It may be replaced with various terms such as an artificial intelligence (AI) system, a roadside unit (RSU), a repeater, a router, a relay, and a gateway.

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

[0039] Reference Figure 1 , the first device 100 and the second device 200 can transmit and receive radio signals through various wireless LAN technologies (e.g., IEEE 802.11 series). The first device 100 and the second device 200 can include interfaces for a media access control (MAC) layer and a physical layer (PHY) that conform to the IEEE 802.11 standard.

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

[0041] The first device 100 may include one or more processors 102 and one or more memories 104, and may further include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memory 104 and / or the transceiver 106 and may be configured to implement the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in this disclosure. For example, the processor 102 may generate first information / signals by processing information in the memory 104 and then transmit a wireless signal including the first information / signals via the transceiver 106. Alternatively, the processor 102 may receive a wireless signal including second information / signals via the transceiver 106 and then store information obtained through signal processing of the second information / signals in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software code including instructions for executing all or part of the processing controlled by the processor 102 or for executing the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in this disclosure. Here, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., the IEEE 802.11 series). The transceiver 106 may be connected to the processor 102 and may transmit and / or receive wireless signals via one or more antennas 108. The transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used in conjunction with an RF (radio frequency) unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0042] The second device 200 may include one or more processors 202 and one or more memories 204, and may further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memory 204 and / or the transceiver 206 and may be configured to implement the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in this disclosure. For example, the processor 202 may generate third information / signals by processing information in the memory 204, and then transmit a wireless signal including the third information / signals via the transceiver 206. Alternatively, the processor 202 may receive a wireless signal including fourth information / signals via the transceiver 206, and then store information obtained from signal processing of the fourth information / signals in the memory 204. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may store software code including instructions for executing all or part of the processing controlled by the processor 202 or for executing the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in this disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., IEEE 802.11 series). The transceiver 206 may be connected to the processor 202 and may transmit and / or receive wireless signals via one or more antennas 208. The transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used in conjunction with an RF unit. In the present disclosure, a device may refer to a communication modem / circuit / chip.

[0043] In the following, the hardware elements of the apparatus 100, 200 will be described in more detail. Without limitation, one or more protocol layers may be implemented by one or more processors 102, 202. For example, one or more processors 102, 202 may implement one or more layers (e.g., functional layers such as PHY, MAC). One or more processors 102, 202 may generate one or more PDUs (Protocol Data Units) and / or one or more SDUs (Service Data Units) according to the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure. One or more processors 102, 202 may generate messages, control information, data, or information according to the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure. One or more processors 102, 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, processes, suggestions, and / or methods disclosed in the present disclosure to provide them to one or more transceivers 106, 206. One or more processors 102, 202 may receive signals (e.g., baseband signals) from one or more transceivers 106, 206 and obtain PDUs, SDUs, messages, control information, data, or information according to the descriptions, functions, processes, suggestions, methods, and / or operational flow diagrams included in the present disclosure.

[0044] The one or more processors 102, 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. The one or more processors 102, 202 may 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 Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) may be included in the one or more processors 102, 202. The descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in the present disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, processes, functions, etc. The firmware or software configured to execute the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in the present disclosure may be included in the one or more processors 102, 202, or may be stored in one or more memories 104, 204 and driven by the one or more processors 102, 202. The descriptions, functions, processes, suggestions, methods and / or operational flow charts included in the present disclosure may be implemented using firmware or software in the form of codes, instructions and / or instruction sets.

[0045] 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 drive, registers, cache memory, computer-readable storage media, and / or combinations thereof. One or more memories 104, 204 can be located internally and / or externally 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 via various technologies such as wired or wireless connections.

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

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

[0048] Hereinafter, the downlink (DL) may refer to a link used for communication from an AP STA to a non-AP STA, and DL PPDUs / packets / signals may be transmitted and received via the DL. In DL communication, the transmitter may be part of an AP STA, and the receiver may be part of a non-AP STA. The uplink (UL) may refer to a link used for communication from a non-AP STA to an AP STA, and UL PPDUs / packets / signals may be transmitted and received via the UL. In UL communication, the transmitter may be part of a non-AP STA, and the receiver may be part of an AP STA.

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

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

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

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

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

[0054] DS refers to the structure of BSS interconnection. Specifically, Figure 2As shown, the BSS can exist as an extended form of a network composed of multiple BSSs. DS is a logical concept and can be specified by the characteristics of the distributed system medium (DSM). At this point, the wireless medium (WM) and the DSM can be logically separated. Each logical medium is used for a different purpose and is used by different components. These media are not limited to being the same, 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 multiple 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 embodiment.

[0055] DS can support mobile devices by providing seamless integration of multiple BSSs and providing the logical services necessary to address the address leading to the destination. In addition, DS can also include a component called a portal, which is used as a bridge for connections between wireless LANs and other networks (e.g., IEEE 802.X).

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

[0057] Data sent from one of the STAs associated with the AP to the STA address of the corresponding AP can always be received at the uncontrolled port and can be processed by the 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.

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

[0059] An ESS refers to a network of arbitrary size and complexity consisting of a DS and a BSS. An ESS may correspond to a set of BSSs connected to one DS. However, an ESS does not include a DS. An ESS network is characterized by being considered an IBSS in the Logical Link Control (LLC) layer. STAs included in an ESS can communicate with each other, and mobile STAs can move from one BSS to another (within the same ESS) transparently to the LLC. APs included in an ESS may have the same service set identifier (SSID). The SSID is distinguished from the BSSID, which is an identifier of a BSS.

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

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

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

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

[0064] Scanning schemes include active scanning and passive scanning. Figure 3The network discovery operation including the active scanning process is exemplarily illustrated. In active scanning, the STA performing the scan sends a probe request frame to discover which APs exist around it while moving through the channel and waits for responses thereto. The responder sends a probe response frame as a response to the probe request frame to the STA that has sent the probe request frame. Here, the responder may be the STA that last sent a beacon frame in the BSS of the channel being scanned. In the BSS, since the AP sends a beacon frame, the AP becomes the responder, and in the IBSS, the STAs in the IBSS rotate to send beacon frames, so the responder is not constant. For example, a STA that sends a probe request frame on channel 1 and receives a probe response frame on channel 1 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 scanning in the same manner (i.e., sending and receiving probe requests / responses on channel 2).

[0065] Although not in Figure 3 Although not shown in FIG, a scanning operation can be performed in a passive scanning manner. In passive scanning, a scanning STA waits for a beacon frame while moving across channels. A beacon frame is one of the management frames defined in IEEE 802.11 and is periodically transmitted to notify the existence of a wireless network and allow a scanning STA to find and participate in the wireless network. In a BSS, an AP is used to periodically transmit beacon frames, and in an IBSS, STAs within the IBSS rotate to transmit beacon frames. When a scanning STA receives a beacon frame, the STA stores the BSS information included in the beacon frame and, while moving to another channel, records the beacon frame information in each channel. The STA that receives the beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform scanning in the next channel in the same manner. Comparing active scanning with passive scanning, the advantage of active scanning is that it has less latency and consumes less power than passive scanning.

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

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

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

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

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

[0071] For example, the association request frame may include information related to various capabilities, a beacon listening interval, a service set identifier (SSID), supported rates, supported channels, an RSN, a mobility domain, supported operation categories, a traffic indication map broadcast request (TIM broadcast request), interworking service capabilities, etc. For example, the association response frame may include information related to various capabilities, 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 ratio indicator (RSNI), a mobility domain, a timeout interval (e.g., association recovery time), overlapping BSS scan parameters, a TIM broadcast response, a quality of service (QoS) map, etc. This corresponds to some examples of information that may be included in the association request / response frame and may be replaced with other information or may further include additional information.

[0072] After the STA successfully associates with the network, a security establishment process may be performed at step S340. The security establishment process at step S340 may be referred to as an authentication process through a Robust Security Network Association (RSNA) request / response, the authentication process at step S320 may be referred to as a first authentication process, and the security establishment process at step S340 may also be referred to simply as an authentication process.

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

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

[0075] In wireless LAN systems, the basic access mechanism for medium access control (MAC) is the Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) mechanism. The CSMA / CA mechanism is also known as the Distributed Coordination Function (DCF) of the IEEE 802.11 MAC and essentially employs a "listen before talk" access mechanism. According to this type of access mechanism, before starting transmission, the AP and / or STA may perform Explicit Channel Assessment (CCA) to sense the radio channel or medium during a predetermined time interval (e.g., the DCF Interframe Space (DIFS)). As a result of this sensing, if the medium is determined to be idle, frame transmission is initiated via the corresponding medium. On the other hand, if the medium is detected to be occupied or busy, the corresponding AP and / or STA does not initiate its own transmission and may set a delay period for medium access (e.g., a random backoff period) and attempt frame transmission after the wait. By applying a random backoff period, collisions can be minimized because multiple STAs are expected to attempt frame transmission after waiting for different time periods.

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

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

[0078] When the random backoff process starts, the STA continuously monitors the medium during the backoff slot countdown according to the determined backoff count value. When the medium is monitored for occupancy, it stops the countdown and waits, and restarts the remaining countdown when the medium becomes idle.

[0079] exist Figure 4 In the example shown, when a packet to be transmitted arrives at STA3's MAC, STA3 can immediately transmit a frame after confirming that the medium has been idle for DIFS. The remaining STAs monitor and wait for the medium to become occupied / busy. Meanwhile, data to be transmitted can also occur at each of STA1, STA2, and STA5. When the medium is detected as idle, each STA waits for DIFS and then begins counting down the backoff slot based on a random backoff count value selected by each STA. Assume that STA2 selects the minimum backoff count value and STA1 selects the maximum backoff count value. This example illustrates a situation where, when STA2 completes the backoff count and begins frame transmission, STA5's remaining backoff time is shorter than STA1's. STA1 and STA5 temporarily stop the countdown and wait while STA2 occupies the medium. When STA2's occupation ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and restart the backoff count where they left off. This means that frame transmission can begin after counting down the remaining backoff slots for the remaining backoff time. Since STA5's remaining backoff time is shorter than STA1's, STA5 begins frame transmission. While STA2 is occupying the medium, data transmission can also occur in STA4. From STA4's perspective, when the medium becomes idle, STA4 can wait for DIFS, then perform a countdown based on a random backoff count value selected by STA4 and begin frame transmission. Figure 4The example shows a situation where STA5's remaining backoff time accidentally conflicts with STA4's random backoff count value. In this case, a collision may occur between STA4 and STA5. When a collision occurs, neither STA4 nor STA5 receives an ACK, and data transmission fails. In this case, STA4 and STA5 can double the CW value, select a random backoff count value, and perform a countdown. While the medium is occupied by STA4 and STA5's transmissions, STA1 waits. When the medium becomes idle, STA1 waits DIFS and then begins frame transmission after the remaining backoff time has elapsed.

[0080] As in Figure 4 In the example, a data frame is a frame used to transmit data forwarded to a higher layer and can be transmitted after a backoff is performed after a DIFS period has elapsed since the medium became idle. Furthermore, a management frame is a frame used to exchange management information that is not forwarded to a higher layer and is transmitted after a backoff is performed after an IFS period, such as a DIFS period or a Point Coordination Function (PIFS) period. Subtypes of management frames include beacons, association requests / responses, reassociation requests / responses, probe requests / responses, and authentication requests / responses. Control frames are frames used to control access to the medium. Subtypes of control frames include request to send (RTS), clear to send (CTS), acknowledgement (ACK), power save poll (PS-Poll), block ACK (BlockAck), block ACK request (BlockACKReq), null data packet announcement (NDP announcement), and triggers. If a control frame is not a response frame to the previous frame, it is transmitted after a backoff is performed after a DIFS period has elapsed. If it is a response frame to the previous frame, it is transmitted without a backoff after a short IFS period (SIFS) has elapsed. The type and subtype of a frame may be identified by the type field and subtype field in the frame control (FC) field.

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

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

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

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

[0085] In order to reduce the possibility of transmission collisions between multiple STAs in the CSMA / CA-based frame transmission operation, a mechanism using RTS / CTS frames can be applied. Figure 5 In the example of , when STA1 is transmitting, as a result of STA3's carrier sensing, it can be determined that the medium is in an idle state. That is, STA1 may correspond to a hidden node with respect to STA3. Alternatively, in Figure 5 In the example shown in FIG1 , it can be determined that the medium is idle based on STA3's carrier sensing result while STA2 is transmitting. In other words, STA2 may correspond to a hidden node with respect to STA3. By exchanging RTS / CTS frames before data transmission and reception between STA1 and STA2, STAs outside the transmission range of either STA1 or STA2, or outside the carrier sensing range of STA1 or STA3's transmission, can avoid attempting to occupy the channel during data transmission and reception between STA1 and STA2.

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

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

[0088] If STA3 cannot overhear a CTS frame from STA2 but can overhear an RTS frame from STA1, STA3 can use the duration information included in the RTS frame to set the NAV timer for the subsequent frame transmission period (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame). Alternatively, if STA3 can overhear a CTS frame from STA2, even if STA3 cannot overhear an RTS frame from STA1, STA3 can use the duration information included in the CTS frame to set the NAV timer for the subsequent frame transmission period (e.g., SIFS + data frame + SIFS + ACK frame). In other words, if STA3 can overhear one or more of the RTS or CTS frames from one or more of STA1 or STA2, STA3 can set the NAV accordingly. When STA3 receives a new frame before the NAV timer expires, STA3 can update the NAV timer using the duration information included in the new frame. STA3 does not attempt channel access until the NAV timer expires.

[0089] When STA1 receives a CTS frame from STA2, STA1 can send a data frame to STA2 after SIFS, starting from the time the CTS frame is received. When STA2 successfully receives the data frame, STA2 can send an ACK frame to STA1 after SIFS as a response to the data frame. When the NAV timer expires, STA3 can determine whether the channel is in use through carrier sensing. If STA3 determines that the channel is not in use by other terminals during the DIFS period after the NAV timer expires, STA3 can attempt channel access after the contention window (CW) based on random backoff has expired.

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

[0091] The PHY layer can prepare the MAC PDU (MPDU) to be transmitted with the help of instructions or primitives (meaning a set of instructions or parameters) from the MAC layer. For example, when a command requesting the PHY layer to start transmission is received from the MAC layer, the PHY layer switches to transmit mode, configures the information provided by the MAC layer (e.g., data) 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 the header of the preamble and sends a command to the MAC layer to notify the PHY layer of the start of reception.

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

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

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

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

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

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

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

[0099] 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 the PPDU preamble of the general PPDU format (i.e., the L-STF, L-LTF, L-SIG fields, and additional non-legacy SIG, non-legacy STF, and non-legacy LTF (if present)) and does not include the remaining portion (i.e., the data field).

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

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

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

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

[0104] Compared to the basic PPDU format, an example of the 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 (such as Figure 7 (d) of FIG). Some fields may be excluded or their lengths may vary according to the detailed example of the HE PPDU format. For example, the HE-SIG-B field is included in the HE PPDU format for multi-user (MU), and the 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 the HE-SIG-B, and the length of the HE-STF field may vary up 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 may vary up to 16 μs. For example, the RL-SIG may be configured to be the same as the L-SIG. Based on the presence of the RL-SIG, the receiving STA may know whether the received PPDU is an HE PPDU or an EHT PPDU, which will be described later.

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

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

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

[0108] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal Signal), and EHT-SIG fields may be coded and modulated so that even legacy STAs can attempt demodulation and decoding, and may be mapped based on a determined subcarrier frequency spacing (e.g., 312.5 kHz). These may be referred to as pre-EHT modulation fields. Subsequently, the EHT-STF, EHT-LTF, data, and PE fields may be coded and modulated so that STAs that successfully decode non-legacy SIGs (e.g., U-SIG and / or EHT-SIG) and obtain the information included in these fields may be demodulated and decoded, and may be mapped based on a determined subcarrier frequency spacing (e.g., 78.125 kHz). These may be referred to as EHT modulation fields.

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

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

[0111] The U-SIG can be constructed in 20MHz units. For example, if an 80MHz PPDU is constructed, the U-SIG can be duplicated. That is, the same four U-SIGs can be included in the 80MHz PPDU. PPDUs with bandwidth exceeding 80MHz can include different U-SIGs.

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

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

[0114] 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 only to 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 the first control bit and the second control bit.

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

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

[0117] Information required for PPDU transmission and reception may be included in the U-SIG. For example, the U-SIG may also include information about bandwidth, information about the MCS technology applied to the non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.), information indicating whether the DCM (Dual Carrier Modulation) technology (e.g., a technology for achieving an effect similar to frequency diversity by reusing the same signal on two subcarriers) is applied to the non-legacy SIG, information about the number of symbols used for the non-legacy SIG, and information about whether the non-legacy SIG is generated across the entire frequency band.

[0118] Some of the information required for PPDU transmission and reception may be included in the U-SIG and / or the non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.). For example, information on the type of 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 preamble puncturing applicable to the PPDU, information on resource unit (RU) allocation, etc. may be included only in the U-SIG, only in the non-legacy SIG, or may be indicated by a combination of information included in the U-SIG and information included in the non-legacy SIG.

[0119] Preamble puncturing may indicate transmission of a PPDU in which no signal exists in one or more frequency bins within the PPDU's bandwidth. For example, the size of a frequency bin (or the resolution of preamble puncturing) may be defined as 20 MHz, 40 MHz, etc. For example, preamble puncturing may be applied to a PPDU bandwidth of a predetermined size or greater.

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

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

[0122] In some cases, the common field can be omitted. For example, in compressed mode without OFDMA (Orthogonal Frequency Division Multiple Access), the common field can be omitted, and multiple STAs can receive the PPDU (e.g., the data field of the PPDU) on the same frequency band. In non-compressed mode with OFDMA, multiple users can receive the PPDU (e.g., the data field of the PPDU) on different frequency bands.

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

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

[0125] A RU can include multiple subcarriers (or tones). RUs can be used when transmitting signals to multiple STAs based on OFDMA technology. In addition, RUs can be defined even when transmitting signals to a single STA. Resources can be allocated for non-legacy STFs, non-legacy LTFs, and data fields in units of RUs.

[0126] The applicable RU size can be defined based on the PPDU bandwidth. The RU can be defined identically or differently for the applied PPDU format (e.g., HEPPDU, EHT PPDU, UHR PPDU, etc.). For example, in the case of an 80MHz PPDU, the RU layout of the HEPPDU and EHT PPDU can be different. The applicable RU size, the number of RUs and RU positions, the DC (direct current) subcarrier position and number, the null subcarrier position and number, the guard subcarrier position and number, etc. for each PPDU bandwidth can be referred to as a tone plan. For example, a tone plan for high bandwidth can be defined in the form of multiple iterations of a low bandwidth tone plan.

[0127] RUs of various sizes can be defined as 26-tone RUs, 52-tone RUs, 106-tone RUs, 242-tone RUs, 484-tone RUs, 996-tone RUs, 2×996-tone RUs, 3×996-tone RUs, and the like. An MRU (Multi-RU) is distinct from multiple individual RUs and corresponds to a group of subcarriers consisting of multiple RUs. For example, an MRU can be defined as 52+26 tones, 106+26 tones, 484+242 tones, 996+484 tones, 996+484+242 tones, 2×996+484 tones, 3×996 tones, or 3×996+484 tones. In addition, the multiple RUs that make up an MRU may or may not be contiguous in the frequency domain.

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

[0129] Figure 7 The names of each field in the PPDU format are exemplary, and the scope of the present disclosure is not limited by these names. In addition, the examples of the present disclosure can be applied to Figure 7 The PPDU format shown in Figure 7 A new PPDU format that excludes some fields and / or adds some fields to the existing PPDU format.

[0130] UP-to-AC mapping

[0131] UP (User Priority) is a value associated with a MAC SDU (MSDU) and may indicate how to handle the corresponding MSDU. UP may be assigned to an MSDU by a higher layer of the MAC.

[0132] AC (Access Category) is a label for a common EDCA parameter set used by QoS STAs that contend for a channel in order to transmit MSDUs with a predetermined priority.

[0133] A Traffic Identifier (TID) corresponds to an arbitrary identifier that can be used by higher-level entities to distinguish an MSDU to a MAC entity supporting QoS within a MAC data service. For example, there may be 16 possible TIDs. Eight of them may identify a Traffic Class (TC), and the remaining eight may identify a Parameterized Traffic Stream (TS). TIDs may be assigned to MSDUs in higher layers of the MAC.

[0134] From the perspective of higher layer entities, a traffic class (TC) corresponds to a label for an MSDU that has a relatively different UP compared to other MSDUs provided for delivery over the same link. The TC may be meaningful to MAC entities that support QoS within the MAC data service. These MAC entities can determine the UP for an MSDU belonging to a specific TC by using the priority value provided to the corresponding MSDU at the MAC Service Access Point (SAP).

[0135] A traffic stream (TS) corresponds to a collection of MSDUs delivered after applying the QoS parameter values provided to the MAC in a specific traffic specification (TSPEC). A TSPEC corresponds to the QoS characteristics of the data flow to / from a QoS STA.

[0136] Table 1 shows the existing defined UP-to-AC mapping.

[0137] [Table 1]

[0138]

[0139] In the example of Table 1, the name column is exemplary, and the actual use of each UP may be defined differently. Background (BK) corresponds to the lowest priority, and voice (VO) corresponds to the highest priority. The order of BK, BE (Best Effort), VI (Video), and VO may correspond to the ascending order of priority.

[0140] As described above, the TID can be provided to the MAC along with the MSDU based on a priority parameter from a higher layer of the MAC. Here, TIDs 0 to 7 can be considered UPs. Each UP can be mapped to a specific AC. In existing WLAN systems, UP-to-AC mapping is defined as a fixed mapping relationship as shown in Table 1. Furthermore, the number of UPs mapped per AC is also fixed and defined as 2. In other words, as shown in Table 1, UPs 1 and 2 are mapped to AC_BK, UPs 0 and 3 are mapped to AC_BE, UPs 4 and 5 are mapped to AC_VI, and UPs 6 and 7 are mapped to AC_VO.

[0141] Flexible UP-to-AC Mapping (FUTA)

[0142] As mentioned above, existing UP-to-AC mapping is fixed and deterministic, and therefore may not support dynamic prioritization of traffic (or MSDUs) for low-latency (LL) applications. In other words, existing fixed UP-to-AC mapping may not effectively support LL traffic. Therefore, a flexible UP-to-AC (FUTA) mapping is needed that dynamically and appropriately modifies UP-to-AC traffic.

[0143] For example, assume that LL traffic and general (or non-LL) traffic coexist in a single AC. If non-LL traffic is mapped to a queue before LL traffic, the transmission of LL traffic may be delayed because the transmission of other packets is delayed due to head-of-line (HOL) blocking (i.e., the first packet in the same queue). In addition, depending on the status of the queues mapped to each AC, it may be necessary to apply AC mapping to LL traffic differently from the existing fixed UP-to-AC mapping so that LL traffic can be sent preferentially.

[0144] This disclosure describes various examples of methods for supporting flexible UP-to-AC mapping for specific traffic (e.g., LL traffic). Although the examples of this disclosure are primarily described assuming LL traffic, the scope of this disclosure is not limited thereto, and flexible UP-to-AC mapping can also be applied to other types of traffic or general traffic. Furthermore, unless specifically limited in the following explanation, a STA may include an AP STA or a non-AP STA.

[0145] Figure 8 is a diagram for explaining an example of FUTA-based operation of an STA according to the present disclosure.

[0146] In S810 , the STA may send a request including information related to a first UP-to-AC mapping to the AP.

[0147] In S820 , the STA may receive a response including at least one of the information related to the second UP-to-AC mapping or whether the information related to the first UP-to-AC mapping is accepted from the AP.

[0148] For example, the first UP-to-AC mapping may include information related to the UP-to-AC mapping that the STA intends to apply (or requests confirmation whether it will be allowed to apply), and the second UP-to-AC mapping may include information related to the UP-to-AC mapping allowed by the AP.

[0149] The information related to the first UP-to-AC mapping and / or the information related to the second UP-to-AC mapping may include an AC index for the UP. Alternatively, the information related to the first UP-to-AC mapping and / or the information related to the second UP-to-AC mapping may include a UP index for the AC. Alternatively, the information related to the first UP-to-AC mapping and / or the information related to the second UP-to-AC mapping may include a UP bitmap for the AC.

[0150] The AC set may include at least one of VO, VI, BE, BK, or an additional (or new) AC. In other words, at least one element may be applied as an AC from a set that includes VO, VI, BE, and BK corresponding to existing ACs, as well as new AC1, new AC2, new AC3, etc. For example, an AC may correspond to an element from a set that is reduced in size compared to the existing four ACs, or may correspond to an element from a set that is expanded to a size exceeding four. The AC set may not include new AC1, new AC2, new AC3, etc.

[0151] The UP set may include at least one of the existing eight UPs (e.g., 0-7, but not limited to 0-7) or at least one additional UP. In other words, at least one element may be applied as a UP from a set that includes 0-7 corresponding to the existing UPs and new UP1, new UP2, new UP3, ... For example, the UP may correspond to an element from a set that is reduced in size compared to the existing eight ACs, or may correspond to an element from a set that is expanded to a size exceeding eight. The UP set may not include new UP1, new UP2, new UP3, ...

[0152] The information related to the first UP-to-AC mapping and / or the information related to the second UP-to-AC mapping may include a presence field. The presence field may indicate which UP-to-AC mapping-related subfield is present among multiple UP-to-AC mapping-related subfields. In other words, the information related to the first UP-to-AC mapping and / or the information related to the second UP-to-AC mapping may include at least one UP-to-AC mapping-related subfield indicated by the presence field.

[0153] The information related to the first UP-to-AC mapping and / or the information related to the second UP-to-AC mapping may include EDCA parameters. For example, the EDCA parameters may include EDCA parameters for each of VO, VI, BE, BK, or at least one of an additional (or new) AC. In other words, at least one element may be applied as an EDCA parameter from a set including EDCA parameters for VO, EDCA parameters for VI, EDCA parameters for BE, EDCA parameters for BK, EDCA parameters for new AC1, EDCA parameters for new AC2, EDCA parameters for new AC3, etc. For example, the EDCA parameter may correspond to an element from a set having a reduced size compared to the EDCA parameters for the existing four ACs, or may correspond to an element from a set having an expanded size exceeding four. The EDCA parameter set may not include new AC1, new AC2, new AC3, etc.

[0154] The information related to the first UP-to-AC mapping and / or the information related to the second UP-to-AC mapping may include information about a UP-to-AC mapping timer. The UP-to-AC mapping timer may indicate the length of time for which the UP-to-AC mapping associated with the corresponding timer is applied. In other words, the corresponding UP-to-AC mapping may be applied while the timer is running, and may not be applied when the timer expires. For example, after the timer expires, a default UP-to-AC mapping may be applied, or a previously indicated UP-to-AC mapping may be applied.

[0155] When the UP-to-AC mapping included in the information related to the first UP-to-AC mapping and / or the information related to the second UP-to-AC mapping is not applied, the fixed UP-to-AC mapping may be applied by default.

[0156] Although not in Figure 8, but before S810, the AP may announce at least one of capability information related to UP-to-AC mapping (i.e., whether flexible UP-to-AC is applicable) or information related to UP-to-AC mapping. The information related to UP-to-AC mapping announced by the AP may include information on candidates for UP-to-AC mappings that the AP can support, and in S810, the STA may request all / part of the candidate UP-to-AC mappings from the AP as information related to the first UP-to-AC mapping. Alternatively, the information related to UP-to-AC mapping announced by the AP may include information on UP-to-AC mappings supported by the AP, and the information related to the announced UP-to-AC mapping may be applied without a request from the STA.

[0157] In S830 , the STA may perform frame exchange with the AP based on the information related to the first or second UP-to-AC mapping.

[0158] In frame exchange, LL traffic can be mapped to a first queue corresponding to a first AC, mapped to a second queue corresponding to a second AC, or mapped to both the first queue and the second queue. The first queue and the second queue may exist on the transmitting side of the LL traffic (which can be a STA or AP).

[0159] For example, when LL traffic is mapped to a first queue and a second queue, if the transmission of the LL traffic included in the first queue is completed, the LL traffic can be deleted from the second queue. For example, when LL traffic is mapped to a first queue and a second queue, if an ACK is received for the transmission of the LL traffic included in the first queue, the LL traffic can be deleted from the second queue. For example, when LL traffic mapped to the second queue is mapped to the first queue (i.e., the queue is changed or the traffic is moved to another queue), the LL traffic can be deleted from the second queue.

[0160] The first queue may be associated with an earlier transmission opportunity (TXOP) than the second queue. For example, a first TXOP corresponding to a first AC or a first queue may precede a second TXOP corresponding to a second AC or a second queue in the time domain. TXOPs on a channel do not overlap, and the next TXOP may be available after any TXOP has terminated.

[0161] Additionally or alternatively, the first queue may correspond to a queue to which the next traffic (e.g., LL traffic) may be sent first, compared to the second queue. When there is a preceding traffic already mapped to any queue, the LL traffic may be mapped after the preceding traffic in the corresponding queue. In other words, the first queue may correspond to a queue with fewer or no preceding traffic, compared to the second queue.

[0162] Additionally or alternatively, when obtaining the first TXOP and the second TXOP compete, the first TXOP may correspond to a TXOP obtained first (or more likely to be obtained first based on a backoff parameter, etc.) than the second TXOP.

[0163] Figure 8 The method described in the example can be used by Figure 1 The first device 100 executes. For example, Figure 1 The at least one processor 102 of the first device 100 in the embodiment may be configured to: send a request including information related to the first user UP-to-AC mapping to the AP; receive a response including information related to the second UP-to-AC mapping from the AP; and perform frame exchange with the AP based on the information related to the second UP-to-AC mapping. In addition, the at least one memory 104 of the first device 100 may store instructions for executing the instructions when executed by the at least one processor 102. Figure 8 Examples or instructions of the methods described in the examples described below.

[0164] Figure 9 is a diagram for explaining an example of FUTA-based operation of an AP according to the present disclosure.

[0165] In S910 , the AP may receive a request including information related to a first UP-to-AC mapping from a STA.

[0166] In S920 , the AP may transmit a response including at least one of the information related to the second UP-to-AC mapping or whether the information related to the first UP-to-AC mapping is accepted to the STA.

[0167] Since the specific details of the information related to the first UP-to-AC mapping and / or the information related to the second UP-to-AC mapping are different from Figure 8 The examples are the same as those described in , so overlapping descriptions are omitted.

[0168] In S930 , the AP may perform frame exchange with the STA based on the information related to the first or second UP-to-AC mapping.

[0169] Since the specific details of frame exchange are Figure 8 The examples are the same as those described in , so overlapping descriptions are omitted.

[0170] Figure 9 The method described in the example can be used by Figure 1 The second device 200 executes. For example, Figure 1The at least one processor 202 of the second device 200 in the embodiment may be configured to: send a request including information related to the first user UP-to-AC mapping from the STA; send a response including information related to the second UP-to-AC mapping to the STA; and perform frame exchange with the STA based on the information related to the second UP-to-AC mapping. In addition, the at least one memory 204 of the second device 200 may store instructions for executing the instructions when executed by the at least one processor 202. Figure 9 Examples or instructions of the methods described in the examples described below.

[0171] Figure 8 and Figure 9 Examples of may correspond to some examples of the various examples of the present disclosure. Figure 8 and Figure 9 Examples of various examples of the present disclosure.

[0172] The embodiments described below describe various examples related to a new flexible UP-to-AC (FUTA) mapping that is different from the existing fixed UP-to-AC mapping. The flexible UP-to-AC (FUTA) mapping of the present disclosure can be applied by replacing the existing fixed UP-to-AC mapping, or the flexible UP-to-AC (FUTA) mapping of the present disclosure can be applied in addition to the existing fixed UP-to-AC mapping (for example, when specific conditions are not met) while the existing fixed UP-to-AC mapping is applied as a default setting (for example, when specific conditions are not met).

[0173] In the following description, UP-to-AC-related information may include information indicating FUTA mapping (i.e., AC mapped to UP or UP mapped to AC), EDCA parameter information for AC based on FUTA mapping, and information about a timer for applying FUTA mapping (i.e., a time for performing channel access and / or frame exchange by applying FUTA mapping).

[0174] Implementation Method 1

[0175] The present embodiments relate to various methods for indicating UP-to-AC mapping according to FUTA.

[0176] Figure 10 and Figure 11 is a diagram illustrating an example of information indicating UP-to-AC mapping according to the present disclosure.

[0177] exist Figure 10 and Figure 11In the example of , the value of M may correspond to the number of UP indexes included in the UP index set. The UP index set may include all or some of the existing UP indexes (e.g., 0-7) and at least one new UP index. In other words, the value of M may be less than 8, 8, or greater than 8. Furthermore, the UP index set may include at least zero existing UP indexes, or may include at least zero new UP indexes. Furthermore, the UP indexes included in the UP index set may be consecutive or non-consecutive.

[0178] For example, when a new UP for a specific type of traffic (e.g., LL traffic) is defined in addition to the existing UPs 0-7, the UP index set may have a size expanded from the existing 7. Alternatively, when the UP for a specific type of traffic is limited to a portion of the existing UPs 0-7, the UP index set may have a size reduced from the existing 7. Alternatively, the UP index set may be configured by including some existing UPs and at least one UP. Alternatively, the UP index set may consist of 0-7 as before, and a method of applying AC mapping differently from the existing default UP-to-AC mapping for each UP may also be included in the FUTA mapping of the present disclosure.

[0179] exist Figure 10 and Figure 11 In the example of [ 0 ], the value of N may correspond to the number of AC indexes included in the AC index set. The AC index set may include all or part of the AC indexes (e.g., 0-3) corresponding to existing ACs (e.g., AC_BK, AC_BE, AC_VO, AC_VI) and at least one new AC index. In other words, the value of N may be less than 4, 4, or greater than 4. Furthermore, the AC index set may include at least zero existing AC indexes or at least zero new AC indexes. Furthermore, the AC indexes included in the AC index set may be consecutive or non-consecutive.

[0180] For example, when a new AC for a specific type of traffic (e.g., LL traffic) is defined in addition to the existing AC_BK, AC_BE, AC_VO, and AC_VI, the AC index set may have a size expanded from the existing 4. Alternatively, when the ACs for the specific type of traffic are limited to a portion of the existing AC_BK, AC_BE, AC_VO, and AC_VI, the AC index set may have a size reduced from the existing 4. Alternatively, the AC index set may be configured by including some existing ACs and at least one AC. Alternatively, the AC index set may consist of AC_BK, AC_BE, AC_VO, and AC_VI as before, and a method of applying UP mapping different from the existing default UP-to-AC mapping for each AC may also be included in the FUTA mapping of the present disclosure.

[0181] Figure 10 (a) shows a field indicating an AC index for each of UP 0, UP 1, ..., UP M. The AC index may be indicated for all M UP indexes included in the UP index set, and may be indicated for only a part of the UP indexes.

[0182] exist Figure 10 In (b), Figure 10 Compared to the example of (a) of , a presence subfield may be added. For example, the presence subfield may include bitmap information. The bitmap may have a length M, and the bit position may correspond to the UP index. For the UP index corresponding to the bit position indicated as the first value (e.g., 1) in the bitmap, a subfield indicating the AC index may exist, and for the UP index corresponding to the bit position indicated as the second value (e.g., 0) in the bitmap, a subfield indicating the AC index may not exist. In other words, since there are as many "AC index subfields for UP indexes" as the number of bits indicated as present in the presence bitmap, the overhead of information indicating FUTA mapping can be reduced.

[0183] Figure 10 (c) shows a field indicating an AC bitmap for each of UP 0, UP 1, ..., UP M. Alternatively, the AC bitmap may not be indicated for all M UP indexes included in the UP index set, and may be indicated for only a part of the UP indexes.

[0184] Although Figure 10 (a) and Figure 10 In the example of (b) only one AC index can be mapped to one UP index, but in Figure 10In the example of (c), at least one AC index may be mapped to one UP index. In order to more flexibly map an AC index to traffic corresponding to one UP index (eg, LL traffic), mapping of multiple AC indexes may be supported.

[0185] exist Figure 10 In (d), Figure 10 Compared to the example of (c), a presence subfield can be added. Figure 10 The description of (b) may include as many “AC bitmap subfields for UP index” as the number of bits indicated as present in the bitmap of the present subfield.

[0186] Figure 11 (a) shows a field indicating a UP index for each of AC 0, AC 1, ..., AC N. The UP index may be indicated for all N AC indexes included in the AC index set, and may be indicated for only a part of the AC indexes.

[0187] exist Figure 11 In (b), Figure 11 Compared to the example of (a) of , a presence subfield may be added. For example, the presence subfield may include bitmap information. The bitmap may have a length N, and the bit position may correspond to the AC index. For the AC index corresponding to the bit position indicated as the first value (e.g., 1) in the bitmap, a subfield indicating the UP index may be present, and for the AC index corresponding to the bit position indicated as the second value (e.g., 0) in the bitmap, a subfield indicating the UP index may not be present. In other words, since there are as many "UP index subfields for AC indexes" as the number of bits indicated as present in the presence bitmap, the overhead of information indicating FUTA mapping can be reduced.

[0188] Figure 11 (c) shows a field indicating an AC bitmap for each of AC 0, AC 1, ..., AC M. Alternatively, the UP bitmap may not be indicated for all N AC indexes included in the AC index set, and may be indicated for only a part of the AC indexes.

[0189] Although Figure 11 (a) and Figure 11 In the example of (b) only one UP index can be mapped to one AC index, but in Figure 11 In the example of (c), at least one UP index may be mapped to one AC index. In order to more flexibly map a UP index to traffic corresponding to one AC index (eg, LL traffic), mapping of multiple UP indexes may be supported.

[0190] exist Figure 11 In (d), Figure 11 Compared to the example of (c), a presence subfield can be added. Figure 11 The description of (b) may include as many “UP bitmap subfields for AC index” as the number of bits indicated as present in the bitmap of the present subfield.

[0191] Implementation Method 2

[0192] This embodiment involves defining and applying a new EDCA parameter set based on the application of FUTA mapping.

[0193] New EDCA parameters can be applied to a set of AC indices associated with the FUTA mapping (i.e., existing AC indices and / or new AC indices). For example, existing EDCA parameters can be applied to existing ACs, and new EDCA parameters can be applied to new ACs. New EDCA parameters can be applied to each of at least one existing AC. In other words, new EDCA parameters can be applied to all or a portion of the ACs included in the AC index set.

[0194] In this way, in addition to modifying / coordinating ACs mapped to specific types of traffic (e.g., LL traffic) through FUTA mapping, priority settings in various aspects can also be supported by modifying / coordinating EDCA parameters for corresponding ACs.

[0195] Figure 12 An example of the EDCA parameter set information element format according to the present disclosure is shown.

[0196] An EDCA parameter set information element (IE) may include an EDCA parameter set (ie, parameter record) for each AC of at least one AC.

[0197] The element ID may be set to a value that identifies the corresponding element associated with the EDCA parameter set. The length field may be set to a value indicating the total length of the fields following the length field. The QoS information (info) field may include information about the EDCA parameter set update count, whether the device has Q-ACK capability, whether the device has queue request capability, whether the device has TXOP request capability, whether the device has more data ACK capability, etc.

[0198] The presence field may include bitmap information. The bitmap may have a length of N, and the bit positions may correspond to AC indices. For AC indices corresponding to bit positions indicated as a first value (e.g., 1) in the bitmap, the EDCA parameter record subfield may be present, and for AC indices corresponding to bit positions indicated as a second value (e.g., 0) in the bitmap, the EDCA parameter record subfield may not be present. In other words, there may be as many "AC Index EDCA Parameter Record" subfields as the number of bits indicated as present in the presence bitmap.

[0199] The EDCA parameter record for each AC index may include an ACI (AC Index) / AIFSN (Arbitration Interframe Space Number) subfield, an ECWmin / ECWmax subfield, and a TXOP Limit subfield. The ACI / AISFN subfield may include information such as AIFSN, Admission Control Mandatory (ACM), and ACI. The ECWmin / ECWmax subfield may include values (e.g., exponential values) used to calculate the minimum and maximum values of the contention window. The TXOP Limit subfield may indicate a value that the TXOP duration must not exceed.

[0200] Implementation 3

[0201] This embodiment relates to conditions for applying FUTA mapping and operations of AP and STA for FUTA application.

[0202] When FUTA mapping is continuously applied until the STA disassociates after associating with the AP, the application condition of FUTA mapping may not be necessary. When FUTA mapping is related to a specific type of traffic (e.g., LL traffic), since such traffic does not always exist, a time condition (e.g., a timer) for applying FUTA mapping may be defined.

[0203] The FUTA mapping timer information may be included in information related to UP-to-AC mapping according to the present disclosure (e.g., referred to as a FUTA mapping information element (IE)). For example, the FUTA mapping IE may include a timer information element (IE) that is referenced by the UP-to-AC mapping element. Figures 10 and 11 Information indicating UP-to-AC mapping is described by reference to Figure 12 At least one of the AC-indexed EDCA parameter set information or the FUTA mapping timer information described. In other words, the FUTA mapping timer information can be defined as a field included in the FUTA mapping IE.

[0204] Figure 13 and Figure 14 is a diagram for explaining an example of operations of an AP and a STA for applying FUTA according to the present disclosure.

[0205] Figure 13 An example is shown for a case where an AP advertises FUTA capability.

[0206] In S1310 , the AP may announce FUTA capability information notifying that FUTA mapping is possible or supports FUTA mapping through a beacon, a probe response, an action frame, or the like.

[0207] In S1320, the STA with FUTA capability may send an association request message including a first FUTA mapping IE to the AP.

[0208] In S1330, the AP may send an association response message including a status code to the STA, where the status code indicates whether the UP-to-AC mapping, EDCA parameter set indexed by AC, FUTA mapping timer, etc. included in the first FUTA Mapping IE requested by the STA (i.e., requested by the STA) are accepted. When the association request is successful, the information requested in the first FUTA Mapping IE may also be accepted. Alternatively, when the AP rejects the information included in the first FUTA Mapping IE, the AP may send the STA its supported or preferred FUTA mapping information (i.e., the second FUTA Mapping IE).

[0209] Additionally or alternatively, the response message may not include a status code indicating whether the first FUTA mapping IE is accepted, but may include the second FUTA mapping IE. In other words, the response message may include information about whether the first FUTA mapping IE is accepted or at least one of the second FUTA mapping IE.

[0210] Therefore, when the FUTA mapping timer is running, channel access / frame exchange between the AP and the STA can be performed based on the first FUTA mapping IE (when the STA's request is accepted) or based on the second FUTA mapping IE (when the STA's request is rejected).

[0211] In addition, after the exchange of FUTA mapping related information is performed during the association process, or when the exchange of FUTA mapping related information is not performed during the association process, the STA may send a FUTA mapping request message including a first FUTA mapping IE to the AP in S1340. The first FUTA mapping IE in S1340 may be the same as or different from the first FUTA mapping IE in S1320. In S1350, the AP may send a FUTA mapping response message including a status code and / or a second FUTA mapping IE indicating whether the first FUTA mapping IE requested by the STA is accepted to the STA. The second FUTA mapping IE in S1350 may be the same as or different from the second FUTA mapping IE in S1330. Therefore, when the FUTA mapping timer is running, channel access / frame exchange between the AP and the STA may be performed based on the first FUTA mapping IE or the second FUTA mapping IE.

[0212] Figure 14 An example of a case where an AP advertises FUTA capability and FUTA mapping IE is shown.

[0213] In S1410, the AP may notify FUTA mapping is possible or supports FUTA mapping FUTA capability information and AP supported FUTA mapping information (i.e., the second FUTA mapping IE) through a beacon, a probe response, an action frame, etc. Here, the AP supported FUTA mapping information may include information about candidates for FUTA mapping related information.

[0214] In S1420, the STA with FUTA capability may send an association request message including a first FUTA mapping IE to the AP. The first FUTA mapping IE may include FUTA mapping related information supported / preferred by the STA among the second FUTA mapping IE (ie, candidates for FUTA mapping related information) announced by the AP.

[0215] Additionally or alternatively, the STA may also send a status code (e.g., 1-bit information) indicating whether to request all second FUTA mapping IEs (i.e., candidates for FUTA mapping related information) announced by the AP to the AP by including it in the association request message. For example, when the STA applies all information included in the second FUTA mapping IE announced by the AP, a status code (e.g., 1-bit information) indicating "all requested" instead of the first FUTA mapping IE may be sent to the AP. Otherwise, the STA may notify the AP of the requested FUTA mapping related information through the first FUTA mapping IE, while sending a status code indicating that it is partially requested to the AP.

[0216] In S1430, the AP may send an association response message to the STA including a status code indicating whether the UP-to-AC mapping, EDCA parameter set indexed by AC, FUTA mapping timer, etc. included in the first FUTA mapping IE requested by the STA (i.e., requested by the STA) are received. When the association request is successful, the information requested by the first FUTA mapping IE may also be accepted. Alternatively, when the AP rejects the information included in the first FUTA mapping IE, the AP may send the STA its supported or preferred FUTA mapping information (i.e., a second FUTA mapping IE that is the same as or different from the FUTA mapping related information notified by the AP in S1410).

[0217] Additionally or alternatively, the response message may not include a status code indicating whether the first FUTA mapping IE was accepted, but may include the second FUTA mapping IE. In other words, the response message may include at least one of information regarding whether the first FUTA mapping IE was accepted or the second FUTA mapping IE. Although the request message sent by the STA includes information indicating that all FUTA mapping-related information is requested, the AP may send a status code indicating success to the STA through the response message to indicate that the corresponding FUTA mapping-related information was finally applied.

[0218] Therefore, when the FUTA mapping timer is running, channel access / frame exchange between the AP and the STA can be performed based on the first FUTA mapping IE or the second FUTA mapping IE.

[0219] In addition, after the exchange of FUTA mapping related information is performed during the association process, or when the exchange of FUTA mapping related information is not performed during the association process, the STA may send a FUTA mapping request message to the AP in S1440, which includes a first FUTA mapping IE and / or a status code indicating whether all candidates of FUTA mapping related information announced by the AP are requested. The first FUTA mapping IE in S1440 may be the same as or different from the first FUTA mapping IE in S1420. In S1450, the AP may send a FUTA mapping response message to the STA including a status code indicating whether the first FUTA mapping IE requested by the STA and / or a second FUTA mapping IE. The second FUTA mapping IE in S1450 may be the same as or different from the second FUTA mapping IE in S1430. Therefore, when the FUTA mapping timer is running, channel access / frame exchange between the AP and the STA may be performed based on the first FUTA mapping IE or the second FUTA mapping IE.

[0220] As an additional example, after the AP announces the FUTA capability and / or the second FUTA mapping IE through a beacon, a probe response, an action frame, etc., the FUTA mapping-related information corresponding to the announced second FUTA mapping IE may be continuously applied without a request from the STA. Accordingly, when a STA with FUTA mapping capability establishes an association with the corresponding AP, the STA may perform channel access / frame exchange, etc. by using the FUTA mapping IE announced by the AP (i.e., applying the FUTA mapping-related information announced by the AP).

[0221] When a first AP is attached to a first AP multi-link device (MLD), if a second AP (e.g., a second AP in the first AP MLD or a second AP in the second AP MLD) enables / advertises FUTA mapping-related information, the first AP may announce the same FUTA mapping-related information as that of the second AP, or may announce information indicating that the FUTA mapping-related information of the second AP also applies to the first AP.

[0222] Implementation 4

[0223] This embodiment relates to a method for transmitting traffic (eg, LL traffic) from a STA after applying FUTA mapping.

[0224] Figure 15 is a diagram illustrating an example of traffic transmission based on FUTA mapping according to the present disclosure.

[0225] exist Figure 15 In this example, assume that the backoff count (BC) of the EDCA function (EDCAF) of AC1 is 5, and the BC of the EDCAF of AC2 is 10. Generally speaking, MSDUs belonging to AC1 are more likely to be transmitted first than MSDUs belonging to AC2. Furthermore, assume that LL traffic for a specific STA is mapped to AC2. Based on this assumption, after terminating a TXOP obtained based on AC1 (i.e., a TXOP whose primary AC is set to AC1), LL traffic mapped to AC2 can be transmitted in a TXOP obtained based on AC2 (i.e., a TXOP whose primary AC is set to AC2). In this case, LL traffic transmission is delayed, and therefore, LL traffic requirements may not be met.

[0226] When FUTA mapping according to the present disclosure is applied, the above-mentioned problem can be solved. For LL traffic whose initial AC is AC2, FUTA mapping can be applied to the LL traffic to modify the UP-to-AC mapping to map it to AC1 (or to AC1 in addition to AC2). This allows LL traffic already mapped to queue 2 corresponding to AC2 to be moved to queue 1 corresponding to AC1, or allows LL traffic newly received from a higher layer to the MAC entity to be mapped to queue 1 corresponding to AC1 instead of queue 2 corresponding to AC2. Therefore, LL traffic can be mapped to queue 1 of AC1 by mapping it to AC1, which can be transmitted faster than AC2.

[0227] Accordingly, LL traffic may be transmitted by being included in the first transmission A-MPDU of TXOP1 (where AC1 is the primary AC), or may be transmitted by being included in an A-MPDU following the A-MPDU being transmitted within TXOP1.

[0228] After TXOP1 terminates, TXOP2 can begin with AC2 as the primary AC. When LL traffic is mapped to both AC1 and AC2 (i.e., LL traffic is mapped to both Queue 1 and Queue 2), after the LL traffic is transmitted in TXOP1 by being mapped to Queue 1 corresponding to AC1, there is no need to transmit the LL traffic from TXOP2, and thus the LL traffic can be deleted from Queue 2 corresponding to AC2. Additionally or alternatively, when LL traffic is mapped to both AC1 and AC2 (i.e., LL traffic is mapped to both Queue 1 and Queue 2), if transmission of the LL traffic mapped to Queue 1 of AC1 is successful (e.g., if an ACK is received for the LL traffic), there is no need to transmit the LL traffic from TXOP2, and thus the LL traffic can be deleted from Queue 2 corresponding to AC2. If no ACK is received for the LL traffic mapped to Queue 1 of AC1 and transmitted from TXOP1 (or if transmission is unsuccessful), the same LL traffic mapped to Queue 2 of AC2 can be transmitted from TXOP2.

[0229] When the mapping of LL traffic originally mapped to AC2 is modified to AC1 through FUTA mapping, the LL traffic mapped to queue 2 of AC2 can be moved to queue 1 of AC1. As a result, the LL traffic can be deleted from queue 2.

[0230] Although fixed UP-to-AC mapping is applied in existing WLAN systems, examples of the present disclosure support flexible UP-to-AC mapping that appropriately modifies the UP-to-AC mapping to effectively coordinate transmission priorities according to traffic characteristics.

[0231] The above-mentioned embodiments are to combine the elements and features of the present disclosure in a predetermined form. Unless otherwise explicitly mentioned, each element or feature should be considered as optional. Each element or feature can be implemented in a form not combined with other elements or features. In addition, the embodiments of the present disclosure may include some elements and / or features of the combination. The order of the operations described in the embodiments of the present disclosure may be changed. Some elements or features of an embodiment may be included in other embodiments, or may be replaced by corresponding elements or features of other embodiments. Obviously, the embodiments may include claims that do not have a clear reference relationship in the combined claims, or may be included as new claims through modification after application.

[0232] It is clear to those skilled in the relevant art that the present disclosure may be implemented in other specific forms within the scope of the essential features of the present disclosure. Therefore, the above detailed description should not be interpreted restrictively in every aspect, but should be considered as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all variations within the scope of equivalents of the present disclosure are included within the scope of the present disclosure.

[0233] The scope of the present disclosure includes software or machine executable commands (e.g., operating systems, applications, firmware, programs, etc.) that perform operations in accordance with the methods of various embodiments in a device or computer, and non-transitory computer-readable media that enable software or commands, etc. to be stored and executable in a device or computer. Commands that can be used to program a processing system that performs the features described in this disclosure can be stored in a storage medium or a computer-readable storage medium, and the features described in this disclosure can be implemented by using a computer program product that includes such a storage medium. The storage medium may include high-speed random access memory, such as, but not limited to, DRAM, SRAM, DDR RAM, or other random access solid-state storage devices, and it may include non-volatile memory, such as, for example, one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory optionally includes one or more storage devices located away from the processor. The memory, or alternatively, the non-volatile memory device in the memory includes a non-transitory computer-readable storage medium. The features described in this disclosure may be stored in any machine-readable medium to control the hardware of a processing system and may be integrated into software and / or firmware that allows the processing system to utilize the results from the embodiments of this disclosure and interact with other mechanisms. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0234] Industrial Applicability

[0235] The method proposed in the present disclosure is mainly described based on an example of application to a system based on IEEE 802.11 (5G 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 station (STA) in a wireless local area network (WLAN) system, the method comprising the following steps: sending a request including information related to a first user priority-to-access category UP-to-AC mapping to an access point AP; receiving a response from the AP including at least one of whether the information related to the first UP-to-AC mapping is accepted or information related to a second UP-to-AC mapping; as well as Frame exchange is performed with the AP based on the information related to the first UP-to-AC mapping or the information related to the second UP-to-AC mapping.

2. The method according to claim 1, wherein At least one of the information related to the first UP-to-AC mapping or the information related to the second UP-to-AC mapping includes one of an AC index for a UP, a UP index for an AC, or a UP bitmap for the AC.

3. The method according to claim 1, wherein The AC belongs to an AC set, which includes at least one of voice VO, video VI, best effort BE, background BK, or at least one additional AC.

4. The method according to claim 1, wherein The UP belongs to a UP set including at least one of 0 to 7 or at least one additional UP.

5. The method according to claim 1, wherein At least one of the information related to the first UP-to-AC mapping or the information related to the second UP-to-AC mapping includes a presence field, and The at least one of the information related to the first UP-to-AC mapping or the information related to the second UP-to-AC mapping includes at least one UP-to-AC mapping related subfield indicated by the presence field.

6. The method according to claim 1, wherein At least one of the information related to the first UP-to-AC mapping or the information related to the second UP-to-AC mapping includes Enhanced Distributed Channel Access (EDCA) parameters.

7. The method according to claim 6, wherein: The EDCA parameters include at least one of the following: EDCA parameters for VO, EDCA parameters for VI, EDCA parameters for BE, EDCA parameters for BK, or EDCA parameters for each additional AC of the at least one additional AC.

8. The method according to claim 1, wherein At least one of the information related to the first UP-to-AC mapping or the information related to the second UP-to-AC mapping includes information about a UP-to-AC mapping timer.

9. The method according to claim 1, wherein Before the STA sends the request, the AP announces at least one of capability information related to UP-to-AC mapping or information related to the UP-to-AC mapping.

10. The method according to claim 1, wherein Based on that a UP-to-AC mapping included in at least one of the information related to the first UP-to-AC mapping or the information related to the second UP-to-AC mapping is not applied, a fixed UP-to-AC mapping is applied by default.

11. The method according to claim 1, wherein In the frame exchange, low-latency LL traffic is mapped to at least one of a first queue corresponding to the first AC or a second queue corresponding to the second AC.

12. The method according to claim 11, wherein Based on the LL traffic being mapped to the first queue and the second queue and the completion of transmission of the LL traffic included in the first queue, the LL traffic is deleted from the second queue.

13. The method according to claim 11, wherein Based on the LL traffic being mapped to the first queue and the second queue and an acknowledgment ACK for the transmission of the LL traffic included in the first queue, the LL traffic is deleted from the second queue.

14. The method according to claim 11, wherein Based on the LL traffic mapped to the second queue being mapped to the first queue, the LL traffic is deleted from the second queue.

15. The method according to claim 11, wherein A first transmission opportunity TXOP corresponding to the first AC or the first queue precedes a second TXOP corresponding to the second AC or the second queue in the time domain.

16. The method according to claim 1, wherein The information related to the second UP-to-AC mapping includes information related to UP-to-AC mapping allowed by the AP.

17. A station (STA) device in a wireless local area network (WLAN) system, the device comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: sending, by the at least one transceiver, to an access point AP, a request including information related to a first user priority-to-access category UP-to-AC mapping; receiving, by the at least one transceiver, a response from the AP including at least one of whether the information related to the first UP-to-AC mapping is accepted or information related to a second UP-to-AC mapping; and Frame exchange is performed with the AP based on the information related to the first UP-to-AC mapping or the information related to the second UP-to-AC mapping through the at least one transceiver.

18. A method performed by an access point (AP) in a wireless local area network (WLAN) system, the method comprising the following steps: receiving from a station STA a request including information related to a first user priority-to-access category UP-to-AC mapping; sending a response to the STA including at least one of whether the information related to the first UP-to-AC mapping is accepted or information related to the second UP-to-AC mapping; as well as Frame exchange is performed with the STA based on the information related to the first UP-to-AC mapping or the information related to the second UP-to-AC mapping.

19. A first access point (AP) device in a wireless local area network (WLAN) system, the device comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: receiving, by the at least one transceiver, a request from a station (STA) including information related to a first user priority-to-access category (UP)-to-AC mapping; transmitting, through the at least one transceiver, to the STA a response including at least one of whether the information related to the first UP-to-AC mapping is accepted or information related to the second UP-to-AC mapping; and Frame exchange is performed with the STA based on the information related to the first UP-to-AC mapping or the information related to the second UP-to-AC mapping through the at least one transceiver.

20. A processing device configured to control a station (STA) in a wireless local area network (WLAN) system, the processing device comprising: at least one processor; as well as At least one computer memory is operatively connected to the at least one processor, and the at least one computer memory stores instructions for performing the method according to claim 1 upon execution by the at least one processor.

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

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