Method and apparatus for classifying low latency traffic in wireless LAN system

Abstract

Disclosed are a method and an apparatus for classifying low latency traffic in a wireless LAN system. A method performed by a first station (STA) in a wireless LAN system may comprise the steps of: receiving, from a second STA, a restricted target wake-up time (R-TWT) related frame, the R-TWT related frame including information on a low latency (LL) related ID for classifying (LL) traffic; and performing a frame exchange with the second STA on the basis of the LL-related ID traffic in an R-TWT service cycle (SP) on the basis of the R-TWT related frame. Here, information about the LL related ID may be indicated based on a specific field of a TWT element in the R-TWT related frame or a specific element in the R-TWT related frame.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for classifying low-latency traffic 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 services. 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 objective of the present disclosure is to provide a method and apparatus for classifying low-latency services in a wireless local area network (WLAN) system.

[0006] The technical purpose of the present disclosure is to provide a method and apparatus for classifying low-latency services using ID information in a process based on a restricted target wake time (TWT).

[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] According to one aspect of the present disclosure, a method performed by a first station (STA) in a wireless LAN system may include: receiving a restricted target wake time (R-TWT)-related frame from a second STA, the R-TWT-related frame including information regarding a low-latency (LL)-related ID for classifying LL services; and performing frame exchange with the second STA based on services according to the LL-related ID within an R-TWT service period (SP) based on the R-TWT-related frame. Here, the information regarding the LL-related ID may be indicated based on a specific field of a TWT element in the R-TWT-related frame or a specific element in the R-TWT-related frame.

[0010] According to additional aspects of the present disclosure, a method performed by a second station (STA) in a wireless LAN system may include: sending a restricted target wake time (R-TWT)-related frame to a first STA, the R-TWT-related frame including information regarding a low-latency (LL)-related ID for classifying LL services; and performing frame exchange with the first STA based on services according to the LL-related ID within an R-TWT service period (SP) based on the R-TWT-related frame. Here, the information regarding the LL-related ID may be indicated based on a specific field of a TWT element in the R-TWT-related frame or a specific element in the R-TWT-related frame.

[0011] Technical Effects

[0012] According to the present disclosure, a method and apparatus for classifying low-latency services in a wireless local area network (WLAN) system may be provided.

[0013] According to the present disclosure, a method and apparatus for classifying low-latency services using ID information in a restricted target wake time (TWT)-based process 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 is a diagram for explaining a link establishment process to which the present disclosure can be applied.

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

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

[0024] Figure 9 is a diagram for explaining an example of a broadcast TWT operation to which the present disclosure can be applied.

[0025] Figure 10 is a diagram for explaining an example of the TWT information element format.

[0026] Figure 11 Quality of Service (QoS) characteristic elements applicable to embodiments of the present disclosure are illustrated.

[0027] Figure 12 The structure of a low-latency service element and the format of a low-latency (LL) ID information field included therein according to an embodiment of the present disclosure are illustrated.

[0028] Figure 13 An LLID subfield included in a control information field of a QoS characteristic element according to an embodiment of the present disclosure is illustrated.

[0029] Figure 14 An LL ID field included in a QoS characteristic element according to an embodiment of the present disclosure is illustrated.

[0030] Figure 15 Existing SCS descriptor elements applicable to the embodiments of the present disclosure are illustrated.

[0031] Figure 16 An SCS descriptor element for indicating an LL ID according to an embodiment of the present disclosure is illustrated.

[0032] Figure 17An LLID-related subfield included in a control information field of a QoS characteristic element according to an embodiment of the present disclosure is illustrated.

[0033] Figure 18 An LL ID size information field included in a QoS characteristics element according to an embodiment of the present disclosure is illustrated.

[0034] Figure 19 An SCS ID / LL ID information field based on a ratio of an SCS ID to an LLID included in an SCS descriptor element according to an embodiment of the present disclosure is illustrated.

[0035] Figure 20 A format indicating the ratio of the lengths of the SCS ID and the LL ID for each ID ratio according to an embodiment of the present disclosure is illustrated.

[0036] Figure 21 An ID Ratio element and an ID Ratio 1 information field within the element according to an embodiment of the present disclosure are illustrated.

[0037] Figure 22 An ID Ratio element and an ID Ratio 2 information field within the element according to an embodiment of the present disclosure are illustrated.

[0038] Figure 23 An existing broadcast TWT parameter set field format that can be applied to the embodiments of the present disclosure is illustrated.

[0039] Figure 24 A restricted TWT service information field based on the LL ID bitmap according to an embodiment of the present disclosure is illustrated.

[0040] Figure 25 An example of a restricted TWT service information field based on LL ID according to an embodiment of the present disclosure is illustrated.

[0041] Figure 26 Another example of the LL ID-based restricted TWT service information field according to an embodiment of the present disclosure is illustrated.

[0042] Figure 27 Another example of the LL ID-based restricted TWT service information field according to an embodiment of the present disclosure is illustrated.

[0043] Figure 28 A restricted TWT service information field based on an LL ID value according to an embodiment of the present disclosure is illustrated.

[0044] Figure 29 An example of a TID-based restricted TWT service information field according to an embodiment of the present disclosure is illustrated.

[0045] Figure 30 An example of a TID mapping LL ID element indicating an LL ID mapped to a TID according to an embodiment of the present disclosure is illustrated.

[0046] Figure 31 Another example of a TID mapping LL ID element indicating an LL ID mapped to a TID according to an embodiment of the present disclosure is illustrated.

[0047] Figure 32 Another example of a TID mapping LL ID element indicating an LL ID mapped to a TID according to an embodiment of the present disclosure is illustrated.

[0048] Figure 33 Another example of a TID mapping LL ID element indicating an LL ID mapped to a TID according to an embodiment of the present disclosure is illustrated.

[0049] Figure 34 An example of R-TWT operation based on the restricted TWT service information field according to an embodiment of the present disclosure is illustrated.

[0050] Figure 35 Another example of R-TWT operation based on the restricted TWT service information field according to an embodiment of the present disclosure is illustrated.

[0051] Figure 36 Another example of R-TWT operation based on the restricted TWT service information field according to an embodiment of the present disclosure is illustrated.

[0052] Figure 37 An operation flowchart of a first STA according to an embodiment of the present disclosure is illustrated.

[0053] Figure 38 An operation flowchart of a second STA according to an embodiment of the present disclosure is illustrated. DETAILED DESCRIPTION

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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".

[0059] 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.

[0060] Hereinafter, technical features of examples to which the present disclosure can be applied will be described.

[0061] Figure 1A block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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., the 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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) 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.

[0073] 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.

[0074] Figure 2 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0075] 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.

[0076] 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 correspond to representative examples of IBSSs, respectively. This configuration is possible when STAs can communicate directly without an AP. In addition, in this type of wireless LAN, it is not 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.

[0077] 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).

[0078] 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.

[0079] 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.

[0080] 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).

[0081] 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.

[0082] 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.

[0083] In addition to the above-mentioned structure of the DS, an extended service set (ESS) can also be configured to provide wide coverage.

[0084] 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.

[0085] 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.

[0086] Figure 3 is a diagram for explaining a link establishment process to which the present disclosure can be applied.

[0087] 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.

[0088] 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.

[0089] 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).

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] The STA may send an authentication request frame to the AP. The AP may determine whether to allow authentication of the corresponding STA based on the information included in the received authentication request frame. The AP may provide the result of the authentication process to the STA via an authentication response frame.

[0095] 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.

[0096] 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, RSN, 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), 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.

[0097] 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.

[0098] 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.

[0099] Figure 4 It is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0100] 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.

[0101] 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).

[0102] 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, ...).

[0103] 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.

[0104] 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.

[0105] 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 request / responses, reassociation request / responses, probe request / responses, and authentication request / 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.

[0106] 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.

[0107] Figure 5 is a diagram for explaining a frame transmission operation based on CSMA / CA to which the present disclosure can be applied.

[0108] As described above, in addition to the physical carrier sensing in which the STA directly senses 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 the STA that is currently using or has 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 that receives 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] When STA1 receives a CTS frame from STA2, STA1 can send a data frame to STA2 after SIFS, starting from the time when 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 being used 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.

[0115] 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.

[0116] 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 the 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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 HEPPDUs, the value of the length field may be determined as a multiple of 3+1 or 3+2.

[0121] The data field may include a service (SERVICE) field, a physical layer service data unit (PSDU), and a PPDU tail bit, and may also include padding bits if necessary. Some bits of the service field may be used for synchronization of the descrambler at the receiving end. The PSDU corresponds to the MAC PDU defined in the MAC layer and may include data generated / used in the upper layer. The PPDU tail bit may be used to return the encoder to the 0 state. The padding bits may be used to adjust the length of the data field in predetermined units.

[0122] 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.

[0123] 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.

[0124] 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).

[0125] 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.

[0126] 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)).

[0127] 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).

[0128] 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)).

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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 long field) and a tail field (e.g., a 6-bit long field). For example, the tail field may be used to terminate the trellis structure of the convolutional decoder and may be set to 0.

[0138] 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 included in the EHT PPDU format and the U-SIG field included in the UHR PPDU format may be included in a new PPDU format (e.g., UHR PPDU format) not shown in the figure. The version-independent bits may be the same, and some or all of the version-dependent bits may be different.

[0139] For example, the size of the version-independent bit of the U-SIG can be fixed or variable. The version-independent bit 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 bit and the version-dependent bit can be referred to by various names, such as the first control bit and the second control bit.

[0140] 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.

[0141] For example, the version-related bits of the U-SIG may include information directly or indirectly indicating the type of the PPDU (eg, SU PPDU, MU PPDU, TB PPDU, etc.).

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.).

[0146] 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.

[0147] 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.

[0148] 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.

[0149] The common field may include a CRC bit and a tail bit, and the length of the CRC bit may be determined to be 4 bits, while the length of the tail bit 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 positions of the RUs to which multiple users (i.e., multiple receiving STAs) are assigned.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] Target Wake Time (TWT)

[0156] TWT is a power saving (PS) technology that can improve energy efficiency of non-AP STAs by defining a service period (SP) between the AP and non-AP STAs and sharing information about the SP with each other to reduce medium contention.

[0157] The STA that performs a request / suggestion / demand, etc. in the TWT establishment step may be referred to as a TWT requesting STA. In addition, the AP that responds to the corresponding request (eg, accept / reject, etc.) may be referred to as a TWT responding STA.

[0158] The establishment step may include a TWT request to the AP of the STA, the type of TWT operation performed, and a process of determining / defining the type of frame sent or received. TWT operations may be divided into individual TWT and broadcast TWT.

[0159] Figure 8 is a diagram for describing an example of a separate TWT operation to which the present disclosure can be applied.

[0160] Separate TWT is a mechanism in which the AP and the non-AP STA perform data exchange after performing negotiation for the non-AP STA in the awake / sleep state through transmission or reception of a TWT request / response frame.

[0161] exist Figure 8 In the example, AP and STA1 can form a trigger-enabled TWT protocol through TWT request frames and TWT response frames.

[0162] Here, the method used by STA1 is a requested TWT method, which is a method in which when STA1 transmits a TWT request frame to the AP, STA1 receives information for TWT operation from the AP through a TWT response frame.

[0163] On the other hand, STA2 that performs the unsolicited TWT method can receive information about the trigger-enabled TWT protocol configuration from the AP through the unsolicited TWT response.

[0164] Specifically, STA2 can calculate the next TWT by adding a specific number from the current TWT value. During the trigger-enabled TWT SP, the AP can send a trigger frame to the STA. The trigger frame can notify the STA that the AP has buffered the data. In response to this, STA1 can notify the AP of its awake state by sending a PS-poll frame. In addition, STA2 can notify the AP of its awake state by sending a QoS empty frame. Here, the data frame sent by STA1 and STA2 can be a frame in the form of a TB PPDU. The AP that confirms the status of STA1 and STA2 can send a DL MU PPDU to wake up the STA. When the corresponding TWT SP expires, STA1 and STA2 can switch to a sleep state.

[0165] Figure 9 is a diagram for describing an example of a broadcast TWT operation to which the present disclosure can be applied.

[0166] Broadcast TWT is a TWT in which a non-AP STA (or TWT-scheduled STA) obtains information about the target beacon transmission time (TBTT) and the listening interval by sending or receiving TWT request / response frames with the AP (or a TWT-scheduled STA). Here, a negotiation operation for TBTT can be performed. Based on this, the AP can define a frame that will include TWT scheduling information through a beacon frame.

[0167] exist Figure 9 In broadcast TWT, STA1 performs requested TWT operation and STA2 performs unsolicited TWT operation. The AP can send a DL MU PPDU after confirming the wake-up state of the STA through a trigger sent by the AP. It can be the same as the process of a separate TWT. In broadcast TWT, the trigger-enabled TWT SP including the beacon frame can be repeated multiple times at a specific interval.

[0168] The transmission of TWT information can be completed through the TWT information frame and the TWT information element. The TWT information frame is sent by the STA to request or send information about the TWT protocol and is sent by an STA of the existing TWT protocol. The action field of the TWT information frame includes the TWT information field.

[0169] The TWT information field may include a 3-bit TWT stream identifier subfield, a 1-bit response request subfield, a 1-bit next TWT request subfield, a 2-bit next TWT subfield size subfield, a 1-bit full TWT subfield, and a 0 / 32 / 48 / 64-bit next TWT subfield.

[0170] Here, the TWT flow identifier subfield can be used to identify the flow requesting / providing TWT information.

[0171] The Response Request subfield may indicate whether the transmitter of the frame including the TWT Information field requests to transmit a TWT information frame (sent in response to receiving the frame). To request the receiver not to transmit a TWT information frame in response to receiving the frame, the Response Request subfield value may be set to 0. To request the receiver to transmit a TWT information frame in response to receiving the frame, the Response Request subfield value may be set to 1.

[0172] To indicate a request to send a TWT information frame containing subsequent TWT fields (when the TWT information frame length is not 0), the Next TWT subfield value may be set to 1. Otherwise, the Next TWT subfield value may be set to 0.

[0173] The Next TWT Subfield Size subfield may indicate the size of the next TWT subfield. When the size of the Next TWT subfield is 0 / 32 / 48 / 64 bits, the value of the Next TWT Subfield Size subfield may be set to 0 / 1 / 2 / 3.

[0174] The HE STA may set all TWT subfield values to 1, which may indicate that the TWT information frame has realigned all TWTs. Otherwise, all TWT subfield values may be set to 0.

[0175] Figure 10 is a diagram for explaining an example of the TWT information element format.

[0176] The TWT element may be transmitted and received in a beacon, a probe response, a (re)association response frame, etc. The TWT element may include an element identifier (element ID) field, a length field, a control field, and a TWT parameter information field.

[0177] The control field of a TWT element has the same format regardless of whether it is a single TWT or a broadcast TWT.

[0178] The NDP Paging Indication subfield may have a value of 1 when the NDP Paging field is present, and may have a value of 0 when the NDP Paging field is not present.

[0179] The responder PM mode subfield may indicate a power management (PM) mode.

[0180] The negotiation type subfield may indicate whether the information included in the TWT element is about negotiation of a broadcast TWT or a separate TWT or about a wake-up TBTT interval.

[0181] For example, when the value of the negotiation type subfield is 0, the TWT subfield is about a future separate TWT SP start time, and the TWT element includes a separate TWT parameter set. This can correspond to a separate TWT negotiation between the TWT requesting STA and the TWT responding STA, or it can correspond to a separate TWT announcement by the TWT responder.

[0182] For example, when the value of the Negotiation Type subfield is 1, the TWT subfield is about the next TBTT time, and the TWT element includes a single TWT parameter set. This can correspond to waking up the TBTT and the wake-up interval negotiation between the TWT-scheduled STA and the TWT-scheduled AP.

[0183] For example, when the value of the negotiation type subfield is 2, the TWT subfield is about the future broadcast TWT SP start time, and the TWT element includes at least one broadcast TWT parameter set. This can correspond to providing a broadcast TWT schedule to a TWT-scheduled STA by including the TWT element in a broadcast management frame sent by the TWT scheduling AP.

[0184] For example, when the value of the Negotiation Type subfield is 3, the TWT subfield is about the future broadcast TWT SP start time, and the TWT element includes at least one broadcast TWT parameter set. This may correspond to managing membership of a broadcast TWT schedule by including the TWT element in a separately addressed management frame sent by either a TWT-scheduled STA or a TWT-scheduled AP.

[0185] When the TWT information frame disable subfield is configured to 1, this means that the STA's reception of the TWT information frame is disabled, otherwise, it can be configured to 0.

[0186] The Wake-up Duration Unit subfield indicates the unit of the Nominal Minimum TWT Wake-up Duration field. When the unit is 256 us, the Wake-up Duration Unit subfield may be configured to 0, and when the unit is TU, the Wake-up Duration Unit subfield may be configured to 1. When it is not a HE / EHT STA, the Wake-up Duration Unit subfield may be configured to 0.

[0187] The most significant bit (MSB) of the negotiation type field may correspond to the broadcast field. When the broadcast field is 1, at least one broadcast TWT parameter set may be included in the TWT element. When the broadcast field is 0, only one single TWT parameter set may be included in the TWT element. A TWT element with the broadcast field configured as 1 may be referred to as a broadcast TWT element.

[0188] In addition, although Figure 10 The case where the reserved field consists of 2 bits is illustrated, but this is only one embodiment. For example, the TWT element may include a link ID bitmap presence field (eg, 1 bit) and a reserved field (eg, 1 bit).

[0189] For example, when the link ID bitmap exists field is set to 1, the link ID bitmap subfield can be set to exist in the separate TWT parameter set field format described later; and when the link ID bitmap exists field is set to 0, the link ID bitmap subfield can be set to not exist in the separate TWT parameter set field format.

[0190] Quality of Service Characteristic Elements

[0191] The QoS Characteristics element defined in the wireless LAN system includes a set of parameters that define the characteristics and QoS expectations of a service flow. In this regard, for a specific non-AP EHT STA, the QoS Characteristics element is used by the EHT AP and non-AP EHT STA to support QoS service transmission using the Flow Classification Service (SCS) procedure and the restricted TWT procedure.

[0192] Figure 11QoS characteristic elements applicable to the embodiments of the present disclosure are illustrated.

[0193] Specifically, the control information field includes a direction subfield, a traffic ID (TID) subfield, a user priority (UP) subfield, an additional parameter presence bitmap subfield, a link ID subfield, and reserved bits (eg, 3 bits).

[0194] The Direction subfield specifies the direction of the data described by the corresponding element and indicates uplink, downlink, direct link, or reserved. Here, uplink refers to the transmission of MSDUs or A-MSDUs from a non-AP STA to an AP, downlink refers to the transmission of MSDUs or A-MSDUs from an AP to a non-AP STA, and direct link refers to the transmission of MSDUs or A-MSDUs via a P2P (peer-to-peer) link.

[0195] The TID subfield contains the TID value of the data frame described by this element. The TID subfield is set to the same value as the UP subfield. Here, TID subfield values 8 to 15 are reserved. In this regard, the presence of the TID subfield may be for future expansion to allow the transmission of TID values independent of user priority (UP).

[0196] The UP subfield contains the UP value (one of 0 to 7) of the data frame described by this element. If a Traffic Classification (TCLAS) element is present in the SCS request frame that includes this element, the UP subfield is set to the UP value specified in the TCLAS element.

[0197] The Additional Parameters Presence Bitmap subfield contains a bitmap whose i-th entry is set to 1 if the i-th field starting from the Maximum MSDU Size field is present in the element. For each field starting from the Maximum MSDU Size field, the value 0 is reserved.

[0198] The Link ID subfield contains the link identifier corresponding to the link over which the direct link transmission is to occur.If the Direction subfield is equal to any value other than indicating a direct link, this subfield is reserved.

[0199] The Minimum Serving Interval field contains an unsigned integer that specifies the minimum interval (e.g., in milliseconds (ms)) between two consecutive Service Periods (SPs) (serving periods, scheduling periods) allocated for frame exchange (e.g., UL / DL / direct link-based frame exchange). The Maximum Serving Interval field contains an unsigned integer that specifies the maximum interval (e.g., in ms) between two consecutive Service Periods (SPs) (serving periods, scheduling periods) allocated for frame exchange (e.g., UL / DL / direct link-based frame exchange). In this regard, the value of the Maximum Serving Interval field is greater than or equal to the value of the Minimum Serving Interval field.

[0200] The Minimum Data Rate field contains an unsigned integer that specifies the minimum data rate (eg, in kilobits per second) specified in MACSAP for sending MSDUs or A-MSDUs belonging to the service flow described by this element.

[0201] The Delay Limit field contains an unsigned integer that specifies the maximum time (in microseconds) allowed for sending an MSDU or A-MSDU belonging to the service flow described by this element.

[0202] The Maximum MSDU Size field contains an unsigned integer that specifies the maximum size (in octets) of an MSDU or A-MSDU belonging to the service flow described by this element.

[0203] The Service Start Time field contains an unsigned integer that specifies the expected time (e.g., in microseconds) when traffic for the associated TID will start. Here, the Service Start Time indicates to the AP the time at which the STA is expected to exchange frames corresponding to the TID specified in this element. This field indicates the lower four octets of the TSF timer associated with the link specified in the Link ID field at the expected start of the SP.

[0204] The four least significant bits (LSBs) of the Service Start Time Link ID field indicate the link identifier corresponding to the link of the TSF timer used to indicate the service start time. The four most significant bits (MSBs) are reserved. This field is present only if the Service Start Time field is present.

[0205] The Average Data Rate field indicates the average data rate (eg, in kilobits per second) specified in the MAC SAP for sending MSDUs or A-MSDUs belonging to the service flow within the bounds of this element.

[0206] The Burst Size field is 4 octets in length and contains an unsigned integer that specifies the maximum burst (i.e., in octets) of MSDUs or A-MSDUs belonging to the service flow that can arrive at the MAC SAP within the time specified in the Delay Limit field.

[0207] The MSDU Time to Live field contains an unsigned integer that specifies the maximum time (in milliseconds) after which an MSDU may become unavailable at the MAC data service interface, even if it has been received by the receiver. Therefore, the MSDU transmitter may consider discarding such an MSDU at the transmitter before sending it over the air. The time specified in this field is greater than or equal to the time specified in the Delay Limit field (if present).

[0208] The MSDU Delivery Information field contains MSDU delivery information. The MSDU Delivery Information field includes an MSDU Delivery Ratio subfield and an MSDU Count Index subfield. Here, the MSDU Delivery Ratio subfield specifies the MSDU loss requirement (e.g., 95% to 99.9999%). The MSDU Count Index subfield contains an unsigned integer that specifies the exponent used to calculate the number of received MSDUs used to calculate the MSDU delivery ratio. In this case, the number of received MSDUs is equal to 10 raised to the MSDU Count Index. If no delay limit is specified, the MSDU Delivery Information subfield is not present.

[0209] Classification of low-latency services and use of identifiers for low-latency service classification in restricted TWT processes use

[0210] In the case of the Stream Classification Service (SCS) procedure defined in existing wireless LAN systems, a STA (e.g., a non-AP STA) includes information for traffic classification in an SCS request frame and requests it from the AP. This traffic classification information can be identified based on an SCS ID. In response, the AP transmits a status for the SCS ID in an SCS response frame. This status allows negotiation, i.e., SCS negotiation for traffic classification, to be completed.

[0211] In this case, the SCSID corresponds to an identifier (e.g., ID) that can be used only between the STA and the AP that transmit and receive SCS request frames and SCS response frames, and corresponds to an identifier (e.g., ID) that can be used only at the MLD level in the case of MLD (Multi-Link Device). That is, STA 1 and STA 2 that have performed SCS negotiation with the AP may not know each other's SCSIDs, nor the traffic classification information included in or associated with the SCS ID.

[0212] For example, the service classification information corresponding to SCS ID 1 of STA 1 and the service classification information corresponding to SCS ID 1 of STA 2 may be the same or different. Additionally or alternatively, the service classification information corresponding to SCS ID 1 of STA 1 and the service classification information corresponding to SCS ID 2 of STA 2 may be the same or different.

[0213] In view of this, the present disclosure proposes a method for defining, sharing, and utilizing a common identifier (e.g., ID) based on classification information of low-latency (or delay-sensitive) services, so that the SCSI ID can be commonly used among STAs that have performed SCS negotiation. The method proposed in the present disclosure is a method for defining, sharing, and utilizing an identifier that allows a STA to indicate the transmission requirements of each low-latency service to the AP and associated STAs.

[0214] Additionally, the present disclosure proposes a method for classifying low-latency services using identifiers in a restricted TWT-based procedure (eg, a restricted TWT establishment procedure).

[0215] The values / names proposed in the present disclosure below are merely examples and are not limited thereto and may be changed / replaced and applied. In addition, the STA in the present disclosure may include non-AP STA and AP STA.

[0216] Implementation Method 1

[0217] This embodiment relates to a method for defining and sharing Low Latency (LL) IDs based on LL-related QoS feature mapping.

[0218] In the present disclosure, the LL ID may correspond to a separate identifier / identification information for classifying low-latency related services / data. That is, the LL ID may be identification information that is different from the existing SCS ID in terms of definition and utilization.

[0219] Specifically, a method is proposed for delivering one or more LL IDs and information for the LL IDs to associated STAs based on LL-related QoS characteristics defined by an AP.

[0220] The AP may share an LL ID commonly used by STAs associated with the AP, and in this case, may also share a value (or values) of a QoS characteristic for LL data (which may be replaced with an LL service name) mapped to each LL ID.

[0221] In this regard, each LL ID in the present disclosure may mean a transmission requirement standard for LL data that can be commonly used by associated STAs.

[0222] The information related to the LL ID may be sent via a frame related to the association process (e.g., a beacon frame or a probe response frame), and may include one or more of the following information:

[0223] -The number of LL IDs defined by the AP in the Reduced Neighbor Report (RNR) element.

[0224] - Contains specific elements mapped to QoS characteristics for each LL ID.

[0225] For example, the AP may inform the STA via a beacon frame / probe response frame using a specific element including information on a criterion for identifying low-latency services based on QoS characteristics of LL data mapped to an LL ID.

[0226] In the following disclosure, for clarity of explanation, this specific element is referred to as a low latency service element (LLT element).

[0227] The low-latency service element can be based on the QoS characteristic element of the SCS request / response frame (for example, Figure 11 The QoS characteristic element of the LL data is configured by the values of all or some fields within the QoS characteristic element, the field value of another element other than the QoS characteristic element, and / or the new field value of a new element indicating the characteristics of the LL data.

[0228] In the present disclosure, a representative example is described in which the value of LL ID is defined as 0 to 7; however, the scope of the present disclosure is not limited thereto. That is, the LL ID proposed in the present disclosure may be defined as having a value less than 7 or a value greater than 7.

[0229] Figure 12 The structure of a low-latency service element and the format of the LL ID information field included therein according to an embodiment of the present disclosure are illustrated.

[0230] For example, the low-latency service element may consist of an element ID field, a length field, an element ID extension field, a low-latency service control field, and (if present) N LL ID information fields.

[0231] Here, the low-latency service control field may include a direction subfield, an LL ID presence indicator subfield, and the like.

[0232] In addition, each LL ID information field may include a minimum service interval subfield, a maximum MSDU size subfield, a minimum data rate subfield, a delay limit subfield, an MSDU delivery ratio subfield, a TID subfield, etc.

[0233] Reference Figure 12 The LL ID N information field may be configured after the low-latency service control field in the low-latency service element. Here, N may correspond to a positive integer including 0.

[0234] At this time, the presence or absence of the LL ID N information field can be indicated in the bitmap format of the LL ID presence indicator subfield in the low-latency service control field. The length of the LL ID presence indicator subfield can be determined based on the number of LL IDs defined by the AP as described above in this disclosure.

[0235] For example, if Figure 12 The length of the LL ID presence indicator subfield in the low-latency service control field in the low-latency service element is 8 bits, and the low-latency service element can be configured as (or can exist) with LL ID 0 information field to LL ID 7 information field. If the value of LL ID is defined to 15, then Figure 12The length of the LL ID presence indicator subfield in the low latency service control field illustrated in FIG may be set to 16 bits. In this case, LL ID 8 to LL ID 15 information fields may be additionally configured (or may exist) after the LL ID 7 information field.

[0236] For another example, if the value of LL ID is defined to 2 (ie, LL ID 0, LL ID 1, LL ID 2), then Figure 12 The length of the LL ID presence indicator subfield in the low-latency service control field illustrated in may be set to 3 bits, and the low-latency service element may be configured (or may exist) with LL ID 0 information field to LL ID 2 information field.

[0237] If the length of the LL ID presence indicator subfield and the direction subfield is not 8 bits, the length of the low-latency service control field may be set to 8 bits using zeros (eg, zero padding).

[0238] Additionally or alternatively, the subfield configurations included in the LL ID N information field (defined by the AP) may not be limited to being the same for each field. For example, the subfield configuration of the LL ID 1 information field may be defined / set to be different from the subfield configuration of the LL ID 2 information field.

[0239] Additionally or alternatively, Figure 12 The configuration of the low-latency service element illustrated in the example is illustrated as being based on (i.e., taking into account) the QoS characteristic value according to which the AP performs scheduling for the UL transmitted service and the DL transmitted service. However, the configuration of the low-latency service element may also be considered without being based on the QoS characteristic value, and therefore may not be limited to Figure 12 Configuration in .

[0240] Implementation Method 2

[0241] This embodiment relates to a method of utilizing an LL ID defined by an AP (ie, the LL ID described in Embodiment 1 of the present disclosure) during an SCS negotiation process between the AP and a STA.

[0242] Here, the SCS negotiation process may be based on an SCS request frame sent by a STA (eg, a non-AP STA) to the AP and an SCS response frame sent by the AP to the STA in response thereto.

[0243] Figure 13 An LLID subfield included in a control information field of a QoS characteristic element according to an embodiment of the present disclosure is illustrated.

[0244] Reference Figure 13 , the LL ID subfield can be configured additionally in Figure 11 The QoS feature element in the control information field may be configured with 3 bits or less after the link ID subfield.

[0245] That is to say, Figure 13 The structure in may correspond to a limited example that may be applied when the length of the LL ID subfield is 3 bits or less.

[0246] Figure 14 An LL ID field included in a QoS characteristic element according to an embodiment of the present disclosure is illustrated.

[0247] Reference Figure 14 , illustrates a case where the length of the LL ID field has a maximum length of 1 octet, but is not limited thereto, and does not exclude a case where the length is greater than or equal to 2 octets.

[0248] For example, if LL ID is defined to 3 (e.g., LL ID 0, LL ID 1, LL ID 2, LL ID 3), then Figure 13 The new LL ID subfield may be present / located by utilizing the reserved bits in the control information field of the QoS feature element as in Figure 14 A new LL ID field is present / located in the QoS characteristic element as in

[15] .

[0249] Regarding the SCS negotiation process, the STA may send an SCS request frame for SCS negotiation with the AP. At this time, the STA may send the SCS request frame by including / setting the LL ID, or may send the SCS request frame without including / setting the LL ID.

[0250] First, a case in which the STA includes the LL ID in the SCS request frame will be described.

[0251] The STA may send an SCS request frame to the AP based on the LL ID and related information announced from the AP. The SCS request frame includes the value of the LL ID that the STA prefers to be mapped to the QoS characteristic element corresponding to the transmission requirements of the low-latency service requested by the STA.

[0252] That is to say, based on Figure 13 or Figure 14 The structure includes the value of the preferred LL ID of the corresponding low-latency service in the QoS characteristic element, and the corresponding QoS characteristic element can be included in the SCS request frame and delivered to the AP.

[0253] In this case, if the LL ID requested by the STA is determined to be a suitable value, the AP may include the same value as the LL ID value requested by the STA in the SCS response frame and transmit it to the STA.

[0254] On the other hand, if the LL ID requested by the STA is determined to be an inappropriate value, the AP can directly determine the LL ID and send it by including a new LL ID value in the SCS request frame. In this case, the new LL ID value can be determined by the AP based on information included in the SCS request frame received from the STA (e.g., QoS characteristics element, etc.) and / or a value corresponding to an element / field including low-latency service information in the LL ID N information field of the low-latency service element provided by the STA. Additionally or alternatively, the AP can request low-latency service-related information from the STA in order to determine the LL ID.

[0255] Next, a case where the STA does not include the LL ID in the SCS request frame will be described.

[0256] During the SCS negotiation process, the STA may send an SCS request frame to the AP without including / setting the LL ID value in the SCS request frame.

[0257] In this case, the AP may send an SCS response frame including a new LL ID value determined by the AP to the STA. The new LLID value may be determined by the AP based on information included in the SCS request frame received from the STA (e.g., QoS characteristics element, etc.) and / or based on one or more elements / fields included in the LL ID N information field of the low-latency service element, which include low-latency service related information provided by the corresponding STA. Additionally or alternatively, the AP may request additional low-latency service related information from the STA in order to determine the LL ID.

[0258] Implementation 3

[0259] This embodiment relates to a method for defining a value of an LL ID for classifying low-latency services based on fields / subfields defined in an existing wireless LAN system.

[0260] That is, in the above-mentioned embodiments (e.g., embodiment 1), the value of the LL ID is defined as a value greater than or equal to 0 based on the low-latency QoS characteristic, but additionally, in this embodiment, the value of the LL ID can be defined based on the field / subfield defined in the conventional wireless LAN system.

[0261] In this regard, an SCS ID value in an SCS descriptor element included in an SCS request / response frame may be used to indicate an LL ID.

[0262] Figure 15 Conventional SCS descriptor elements applicable to embodiments of the present disclosure are illustrated.

[0263] Reference Figure 15 The SCS descriptor element may include an SCS identifier (ie, an SCS ID field) used in the SCS negotiation process, and a QoS characteristic element related to the corresponding flow / service.

[0264] Here, the SCS ID corresponds to an identifier (ie, ID) used only between the AP and STAs that have entered into SCS negotiation. The value of the LL ID may be set accordingly so that the value of the SCS ID can be commonly used among STAs associated with the AP.

[0265] However, the conventionally defined SCS ID is one octet long, which is relatively long. Therefore, when multiple LLIDs are used, there is a disadvantage that overhead may increase. Therefore, sharing the SCS ID value as is for associated STAs can be cumbersome, and a method to compensate for this is needed.

[0266] To solve such problems, one or more of the following methods may be applied.

[0267] (Method 1)

[0268] Method 1 is a method of indicating LLID by using the SCS ID value of the SCS descriptor element in the SCS request / response frame. Specifically, Method 1 is a method of defining LL ID by using some bit values of the SCS ID field in the LL ID field / subfield, as shown in Figure 13 and Figure 14 As shown in the example.

[0269] That is, the LL ID can be defined in one of the following ways:

[0270] - A method of defining the last 4 bits of the 8-bit SCS ID field as the LL ID;

[0271] - A method of defining the last 3 bits of the 8-bit SCS ID field as the LL ID;

[0272] - A method of defining the last 2 bits of the 8-bit SCS ID field as the LL ID;

[0273] - A method of defining the last bit of the 8-bit SCS ID field as the LL ID;

[0274] - A method of defining the first 4 bits of the 8-bit SCS ID field as the LL ID;

[0275] - A method of defining the first 3 bits of the 8-bit SCS ID field as the LL ID;

[0276] - A method of defining the first 2 bits of the 8-bit SCS ID field as the LL ID;

[0277] - A method of defining the first bit of the 8-bit SCS ID field as the LL ID.

[0278] In this regard, the STA performing SCS negotiation with the AP may transmit an SCS request frame including a value of the LL ID field / subfield in the corresponding QoS characteristics element, or may transmit it without including the value.

[0279] If the AP receives an SCS request frame including the LL ID field / subfield in the QoS characteristics element, the AP may transmit an SCS response frame including the LLID field / subfield in the QoS characteristics element, or may transmit an SCS response frame not including the LL ID field / subfield in the QoS characteristics element.

[0280] Alternatively, if the AP receives an SCS request frame that does not include the LL ID field / subfield in the characteristics element, the AP may send an SCS response frame that includes the LL ID field / subfield in the QoS characteristics element, or may send an SCS response frame that does not include the LL ID field / subfield in the QoS characteristics element.

[0281] In case of method 1, when the indication of the LL ID is performed, the value of the existing SCS ID is not changed.

[0282] (Method 2)

[0283] Method 2 is a method of indicating LLID by using the SCS ID value of the SCS descriptor element in the SCS request / response frame. Specifically, Method 2 is a method such as Figure 16 This figure shows a method of dividing an SCS ID having a length of 1 octet and using it to indicate an LL ID.

[0284] Figure 16 An SCS descriptor element for indicating an LL ID according to an embodiment of the present disclosure is illustrated.

[0285] Reference Figure 16 The value of LL ID can be indicated by utilizing the existing SCS ID field. This field can be named SCS ID / LL ID field.

[0286] For example, a STA and / or AP supporting a next-generation wireless LAN system may be configured / defined to verify the SCS ID and LL ID by decoding the corresponding fields of the SCS descriptor element. Conversely, a STA and / or AP that does not support the corresponding fields may be configured / defined to verify the SCS ID only by decoding them.

[0287] The SCS ID and LL ID in the above fields can be defined in one of the following ways:

[0288] Method A: The number of digits in the LL ID is less than or equal to the number of digits in the SCS ID being divided:

[0289] - A method of defining the first 4 bits of an 8-bit SCS ID field as the SCS ID and the remaining 4 bits as the LL ID;

[0290] - A method of defining the first 5 bits of an 8-bit SCS ID field as the SCS ID and the remaining 3 bits as the LL ID;

[0291] - A method of defining the first 6 bits of an 8-bit SCS ID field as the SCS ID and the remaining 2 bits as the LL ID;

[0292] - A method of defining the first 7 bits of an 8-bit SCS ID field as the SCS ID and the remaining 1 bit as the LL ID;

[0293] - A method of defining the first 4 bits of an 8-bit SCS ID field as LL ID and the remaining 4 bits as SCS ID;

[0294] - A method of defining the first 3 bits of an 8-bit SCS ID field as LL ID and the remaining 5 bits as SCS ID;

[0295] - A method of defining the first 2 bits of an 8-bit SCS ID field as LL ID and the remaining 6 bits as SCS ID;

[0296] - A method of defining the first 1 bit of an 8-bit SCS ID field as LL ID and the remaining 7 bits as SCS ID.

[0297] For example, if the 8-bit value of the SCS ID field is 10000111, and the first 4 bits are defined as the SCS ID and the last 4 bits are defined as the LL ID, the SCS ID may be set to 1000 and the LL ID may be set to 0111.

[0298] Method B. A method where the SCS ID has an 8-bit length regardless of the number of LL ID digits:

[0299] - A method of defining the last 4 bits of the 8-bit SCS ID field as the LL ID;

[0300] - A method of defining the last 3 bits of the 8-bit SCS ID field as the LL ID;

[0301] - A method of defining the last 2 bits of the 8-bit SCS ID field as the LL ID;

[0302] - A method of defining the last bit of the 8-bit SCS ID field as the LL ID;

[0303] - A method of defining the first 4 bits of the 8-bit SCS ID field as the LL ID;

[0304] - A method of defining the first 3 bits of the 8-bit SCS ID field as the LL ID;

[0305] - A method of defining the first 2 bits of the 8-bit SCS ID field as the LL ID;

[0306] - A method of defining the first bit of the 8-bit SCS ID field as the LL ID.

[0307] For example, when the value of the 8-bit SCS ID field is 10000111, if the last 4 bits of the 8 bits are defined as LL ID, the SCS ID may be set to 10000111 and the LL ID may be set to 0111.

[0308] Figure 16 The SCS ID / LL ID field in the SCS request frame may be included in both the SCS request frame and the SCS response frame, or may be included only in the SCS request frame, or only in the SCS response frame.

[0309] In case of method 2, it is different from method 1 in that, when indication of the LL ID is performed, a new field / subfield for indicating the LL ID is not added within the QoS characteristics element.

[0310] (Method 3)

[0311] Method 3 is a method of indicating the LL ID by using a part of the SCS ID value of the SCS descriptor element in the SCS request / response frame.

[0312] Figure 17 and Figure 18 The method exemplified in the above may correspond to Figure 13 and Figure 14The method illustrated in is to utilize the reserved bits in the control information field of the QoS characteristic element or to define a new field in the QoS characteristic element.

[0313] Figure 17 An LLID-related subfield included in a control information field of a QoS characteristic element according to an embodiment of the present disclosure is illustrated.

[0314] Reference Figure 17 A 2-bit LL ID Size subfield may be included in the Control Information field of the QoS Feature Element to indicate how many bits of the SCS ID field are set as the LL ID. Additionally, a 1-bit LL ID LSB / MSB subfield may be included in the Control Information field of the QoS Feature Element to indicate whether the bit corresponds to the least significant bit (LSB) (i.e., the leftmost bit) or the most significant bit (MSB) (i.e., the rightmost bit) of the SCSI ID.

[0315] Figure 18 An LL ID size information field included in a QoS characteristics element according to an embodiment of the present disclosure is illustrated.

[0316] Reference Figure 18 , LL ID size information field of 1 octet length (including Figure 17 The two subfields illustrated in (ie, LL ID size subfield and LL ID LSB / MSB subfield)) may be defined as new fields within the QoS Characteristics element.

[0317] If the LL ID LSB / MSB subfield does not exist, it may be assumed that the STA has defined, pre-agreed, or pre-known whether the bits indicated by the LL ID Size subfield are based on the LSB or MSB of the SCS ID.

[0318] Therefore, unlike the above method, this method has the technical effect of being able to dynamically use SCS IDs and LL IDs of different lengths. To this end, the QoS characteristic element in this method can include information for dynamically changing lengths in a specific field / subfield.

[0319] (Method 4)

[0320] Method 4 involves restructuring the SCS ID field of the SCS descriptor element in the SCS request / response frame to divide the lengths of the SCS ID and LL ID by a certain ratio. This method also has a similar technical effect as Method 3, allowing the lengths of the SCS ID and LL ID to be dynamically changed.

[0321] Figure 19An SCS ID / LL ID information field based on a ratio of an SCS ID to an LL ID, included in an SCS descriptor element according to an embodiment of the present disclosure, is illustrated.

[0322] Reference Figure 19 The SCS ID / LL ID Information field may be configured to include an ID Ratio subfield indicating a length ratio between the SCS ID and the LL ID, and an SCS ID / LL ID subfield indicating each of the SCS ID and the LL ID based on a value of the ID Ratio subfield.

[0323] For example, when the length of the SCS ID / LL ID information field is defined as 1 octet, the ID Ratio subfield may consist of N bits, and the SCS ID / LL ID subfield may consist of 8-N bits.

[0324] In this regard, a length ratio between the SCS ID and the LL ID in the SCS ID / LL ID field may be differently configured / set according to the length of the ID ratio subfield within the SCS ID / LL ID information field.

[0325] The length of the ID Ratio subfield and the length ratio between the SCS ID and the LL ID according to its value may be configured / set as in the following example.

[0326] For example, when the length of the ID Ratio subfield is 1 bit, the length of the SCS ID / LL ID subfield may correspond to 7 bits. Specifically, when the value of the ID Ratio subfield is 0 or 1, the configurable ratio between the SCS ID and the LL ID (i.e., SCS ID:LL ID) may be as follows.

[0327] i)7:0

[0328] ii) 6:1

[0329] iii)5:2

[0330] iv) 4:3

[0331] v) 3:4

[0332] vi) 2:5

[0333] vii) 1:6

[0334] viii)0:7

[0335] In another example, when the length of the ID Ratio subfield is 2 bits, the length of the SCS ID / LL ID subfield may correspond to 6 bits. Specifically, when the value of the ID Ratio subfield is 0 to 3, the configurable ratio between the SCSI ID and the LL ID (i.e., SCSI ID:LL ID) may be as follows.

[0336] i)6:0

[0337] ii)5:1

[0338] iii) 4:2

[0339] iv) 3:3

[0340] v) 2:4

[0341] vi) 1:5

[0342] vii)0:6

[0343] As mentioned above, the length of SCS ID and LL ID can be determined based on Figure 19 The length ratio of the SCS ID and LL ID based on the value of the ID Ratio subfield in the LL ID subfield may vary. Therefore, information about the length ratio of the SCS ID and LL ID based on the value of the ID Ratio subfield needs to be shared in advance between the AP and (one or more) STAs. In this case, this information can be sent through a beacon frame and / or a probe response frame sent by the AP.

[0344] Based on the contents described in this disclosure, information on the length ratio of the SCS ID and the LL ID according to the value of each ID ratio can be as follows: Figure 20 Configured as shown.

[0345] Figure 20 A format indicating a ratio of the lengths of an SCS ID and an LL ID for each ID ratio according to an embodiment of the present disclosure is illustrated.

[0346] Reference Figure 20 , this format may include a 1-bit or 2-bit ID Ratio field, a 3-bit SCS ID Size field, and a 3-bit LL ID Size field. Here, the number of bits of the SCS ID Size field and the LL ID Size field may be defined / set based on the maximum value in the above ratio example (e.g., 7 when the ID Ratio field value is 0 or 1, and 6 when the ID Ratio field value is 0 to 3).

[0347] In this regard, when the length of the ID Ratio field is 1 bit, the ID Ratio field may have a value of 0 or 1, and as Figure 20The two formats shown can be positioned / existed consecutively. By this, based on the value of each ID Ratio field, the SCS ID Length Ratio can be set in the SCS ID Size field, and the LL ID Length Ratio can be set in the LL ID Size field.

[0348] Additionally, when the length of the ID Ratio field is 2 bits, the ID Ratio field can have a value of 0 to 3, and as Figure 20 The four formats shown can be positioned / existed consecutively. By this, based on the value of each ID ratio field, the SCS ID length ratio can be set in the SCS ID size field, and the LL ID length ratio can be set in the LL ID size field.

[0349] based on Figure 20 In the format illustrated in FIG, a new element for indicating information about the ID ratio can be defined, and can be used as will be described later. Figure 21 and Figure 22 As described above, this new element may be delivered via a beacon frame and / or a probe response frame sent by the AP.

[0350] In this disclosure, for clarity of explanation, this new element is referred to as an ID ratio element (SCS / LL ID).

[0351] Figure 21 An ID Ratio element and an ID Ratio 1 information field within the element according to an embodiment of the present disclosure are illustrated.

[0352] Reference Figure 21 , the ID Ratio element may be configured to include an ID Ratio Control field, an ID Ratio 1 Information field (optional) and / or an ID Ratio 2 Information field (optional).

[0353] The ID Ratio Control field may include a subfield indicating whether an ID Ratio 1 Information field exists in the ID Ratio element (ID Ratio 1 Information exists) and a subfield indicating whether an ID Ratio 2 Information field exists (ID Ratio 2 Information exists).

[0354] In this regard, the ID Ratio 1 information field may indicate the Figure 20 The ID ratio field in the has 1-bit length and is related to the case information.

[0355] If the SCS ID / LL ID information field in the SCS descriptor element (e.g. Figure 19 The length of the ID ratio field of the SCS ID / LL ID information field in the ID ratio element is 1 bit, and the STA receiving the ID ratio element can be based on Figure 21 The SCS ID and LL ID are defined using the information included in the

[0356] At this time, within the ID Ratio 1 information field, each ID Ratio field is configured by being concatenated with one SCS ID Size field and one LL ID Size field. In other words, one SCS ID Size field and one LL ID Size field can be configured / concatenated as a set to one ID Ratio field within the ID Ratio 1 information field.

[0357] The ID Ratio 1 Information field may have a length of 0 octets, 1 octet, or 2 octets depending on the value of the ID Ratio defined between the AP and (one or more) STAs. For example, when both a value of 0 and a value of 1 are defined for the ID Ratio defined between the AP and the STA, the length of the ID Ratio 1 Information field may be set to 2 octets. Conversely, when either a value of 0 or a value of 1 is defined for the ID Ratio between the AP and the STA, the length of the ID Ratio 1 Information field may be set to 1 octet.

[0358] Figure 22 An ID Ratio element and an ID Ratio 2 information field within the element according to an embodiment of the present disclosure are illustrated.

[0359] Reference Figure 22 , the ID Ratio element may be configured to include an ID Ratio Control field, an ID Ratio 1 Information field (optional) and / or an ID Ratio 2 Information field (optional).

[0360] The ID Ratio Control field may include a subfield indicating whether an ID Ratio 1 Information field exists in the ID Ratio element (ID Ratio 1 Information exists) and a subfield indicating whether an ID Ratio 2 Information field exists (ID Ratio 2 Information exists).

[0361] In this regard, the ID Ratio 2 information field may indicate the Figure 19 The ID ratio field in the is 2-bit length and is related to the case.

[0362] If the SCS ID / LL ID information field in the SCS descriptor element (e.g. Figure 19 The length of the ID ratio field of the SCS ID / LL ID information field in the ID ratio element is 2 bits, and the STA receiving the ID ratio element can be based on Figure 22 The SCS ID and LL ID are defined using the information included in the

[0363] In this case, in the ID Ratio 2 information field, each ID Ratio field is configured in conjunction with one SCS ID Size field and one LL ID Size field. In other words, in the ID Ratio 2 information field, one ID Ratio field can be necessarily configured / connected with one SCS ID Size field and one LL ID Size field as a set.

[0364] Depending on the value of the ID ratio defined between the AP and (one or more) STAs, the ID Ratio 2 Information field may have a length of 0 octets, 1 octet, 2 octets, 3 octets, or 4 octets. For example, when all ID ratio values from 0 to 3 are defined between the AP and the STA, the length of the ID Ratio 2 Information field may be set to 4 octets. Conversely, when no ID ratio values up to 3 are defined between the AP and the STA, the length of the ID Ratio 2 Information field may be set to 1 octet, 2 octets, or 3 octets.

[0365] Based on the above method 1, method 2, method 3 and / or method 4, an identifier (ie, the above LL ID) for indicating / sharing the transmission requirement of the low-latency service may be defined, shared and utilized.

[0366] Implementation 4

[0367] The present embodiment relates to a method of using an LL ID in a restricted TWT (R-TWT) related procedure for an STA supporting the R-TWT among STAs associated with an AP.

[0368] Specifically, this embodiment proposes a method of including / utilizing LL ID related information in the R-TWT establishment process, the R-TWT negotiation process, and the R-TWT Service Period (SP) notification process.

[0369] Through the information related to the LL ID, all STAs supporting R-TWT can realize that R-TWT scheduling is specifically used for the transmission and reception of the specific LL ID announced by the AP (that is, the transmission and reception of services / data corresponding to the specific LL ID). Accordingly, the utilization of R-TWT in the transmission and reception of low-latency services can be maximized.

[0370] Figure 23 An existing broadcast TWT parameter set field format that can be applied to the embodiments of the present disclosure is illustrated.

[0371] Reference Figure 23, in the case of the Broadcast TWT Parameter Set field of the previously defined Broadcast TWT element, a service ID (TID) may be used to indicate a specific service within the R-TWT SP (e.g., an R-TWT-related low-latency service).

[0372] In this regard, during R-TWT establishment (or negotiation) and R-TWT SP announcement, the restricted TWT service information field in the broadcast TWT element can be used to share relevant information between the AP and STA.

[0373] For example, the restricted TWT service information field may consist of a 1-octet service information control subfield, a 1-octet restricted TWT DL TID bitmap subfield, and a 1-octet restricted TWT UL TID bitmap subfield. Here, the service information control field may include a 1-bit DL TID bitmap valid subfield and a 1-bit UL TID bitmap valid subfield.

[0374] like Figure 23 As illustrated, since low-latency services related to R-TWT are indicated using TID values 0 to 7, there is a problem that the same information may not be used to identify low-latency services outside the R-TWT SP. Additionally or alternatively, there is a problem that information in the QoS characteristic element (such as the transmission requirements of low-latency services corresponding to each TID) may not be correlated.

[0375] Taking these points into consideration, a specific method for constructing a new restricted TWT service information field is proposed below, which uses the LL ID described in this disclosure to indicate low-latency services.

[0376] The methods described below are differentiated for clarity of description, and do not exclude the situation where some components of a specific method are replaced by or combined with some components of other methods.

[0377] (Method 1)

[0378] The restricted TWT service information field proposed in this disclosure can be defined in the following way: Figure 23 The method of using TID to indicate UL low latency service and DL low latency service described in is replaced by a method of using LL ID to indicate UL low latency service and DL low latency service.

[0379] Figure 24 A restricted TWT service information field based on the LL ID bitmap according to an embodiment of the present disclosure is illustrated.

[0380] Reference Figure 24, the restricted TWT service information field included in the broadcast TWT parameter set field format may include a service information control subfield, a restricted TWT DL LL ID bitmap subfield, and a restricted TWT UL LL ID bitmap subfield. Additionally, the service information control field may include a 1-bit DL LL ID bitmap valid subfield and a 1-bit ULLL ID bitmap valid subfield.

[0381] In this regard, information of the low-latency service indicated by the restricted TWT parameter set field including each subfield transmitted during the R-TWT SP may be commonly shared between the AP and associated STAs based on the LL ID.

[0382] for Figure 24 In the broadcast TWT parameter set field format illustrated in , the length of the restricted TWT service information field can be determined in octets based on the number of LL IDs defined by the AP.

[0383] For example, Figure 24 The lengths of the restricted TWT DL LL ID bitmap subfield and the restricted TWT UL LL ID bitmap subfield illustrated in the can be set to be variable based on the number of LL IDs defined (by the AP). As a specific example, when the number of defined LL IDs is M, the length of the restricted TWT DL LL ID bitmap subfield can be set to M bits, and the length of the restricted TWT UL LL ID bitmap subfield can be set to M bits.

[0384] Figure 25 An example of a restricted TWT service information field based on LL ID according to an embodiment of the present disclosure is illustrated.

[0385] Reference Figure 25 , when the number of LL IDs determined / defined by the AP is greater than or equal to 1 and less than or equal to 4, the Restricted TWT DL LL ID Bitmap subfield and the Restricted TWT UL LL ID Bitmap subfield in the Restricted TWT Service Information field each have a length of at most 4 bits. In this case, the Restricted TWT Service Information field has a length of at most 2 octets.

[0386] In this case, since the restricted TWT service information subfield in the existing broadcast parameter set field that uses TID to indicate low-latency services has a length of 3 octets, overhead can be reduced. In addition, according to this example, there is an advantage that by using the LL ID, the transmission requirements of the low-latency services transmitted and received during the R-TWTSP can be shared in detail with the associated STAs supporting R-TWT.

[0387] Figure 26 Another example of the LL ID-based restricted TWT service information field according to an embodiment of the present disclosure is illustrated.

[0388] Reference Figure 26 When the number of LL IDs determined / defined by the AP is greater than 4 and less than or equal to 8, the Restricted TWT DL LL ID Bitmap subfield and the Restricted TWT UL LL ID Bitmap subfield in the Restricted TWT Service Information field each have a length of at most 8 bits (i.e., at most 1 octet). In this case, the Restricted TWT Service Information field has a length of at most 3 octets.

[0389] In this case, since the restricted TWT service information subfield in the existing broadcast parameter set field that indicates the low-latency service using TID has a length of 3 octets, no additional octets are required. Therefore, there is an advantage in that the transmission requirements of the low-latency service transmitted and received during the R-TWT SP can be shared in detail between the associated STAs supporting R-TWT by using the LL ID without an additional octet.

[0390] Figure 27 Another example of the LL ID-based restricted TWT service information field according to an embodiment of the present disclosure is illustrated.

[0391] Reference Figure 27 , when the number of LL IDs determined / defined by the AP is greater than 8 and less than or equal to 16, the Restricted TWT DL LL ID Bitmap subfield and the Restricted TWT UL LL ID Bitmap subfield in the Restricted TWT Service Information field each have a length of at most 16 bits (i.e., at most 2 octets). In this case, the Restricted TWT Service Information field has a length of at most 5 octets.

[0392] In this case, since the restricted TWT service information subfield in the existing broadcast parameter set field that uses TID to indicate low-latency services has a length of 3 octets, there may be greater overhead. That is, as the number of LL IDs defined by the AP increases, the length of the restricted TWT service information field becomes longer, which may result in greater overhead.

[0393] (Method 2)

[0394] The above-mentioned method 1 is a method of indicating the LL ID in a bitmap format, and method 2 is a method of using the value of the LL ID to indicate the low-latency service to be transmitted and received within the R-TWT SP.

[0395] Figure 28 A restricted TWT service information field based on an LL ID value according to an embodiment of the present disclosure is illustrated.

[0396] Reference Figure 28 , the restricted TWT service information field included in the broadcast TWT parameter set field format may include a service information control subfield, a restricted TWT DL LL ID list subfield, and a restricted TWT UL LL ID list subfield.

[0397] In this regard, the restricted TWT DL LL ID list subfield and the restricted TWT UL LL ID list subfield may include LL IDs in an array format and may indicate low-latency services with corresponding LLIDs that can be transmitted and received within the R-TWT SP.

[0398] Figure 28 The length of the restricted TWT DL LL ID list subfield and the restricted TWT UL LL ID list subfield in the field may vary depending on the length of the LL ID and the number of LL IDs included in each subfield. When the restricted TWT service information field is configured by the STA, the length of the field can be configured in units of eight bits by using 0 (e.g., zero padding).

[0399] Additionally, the service information control field may include a DL LL ID bitmap valid subfield, a UL LL ID bitmap valid subfield, and an LL ID size subfield that may indicate the length of the LL ID. Based on the length of the LL ID indicated by the LL ID size subfield, the STA may identify the LL ID included in the restricted TWT DL LL ID list subfield and the restricted TWT DLL LL ID list subfield.

[0400] Additionally or alternatively, if the STA knows the length of the LL ID, the LL ID size subfield may be omitted. Additionally or alternatively, although Figure 28 The LL ID size subfield is illustrated as 6 bits in FIG, but this is to reflect the aspect of utilizing existing reserved bits, and LL ID size subfields of other lengths may be defined.

[0401] (Method 3)

[0402] Method 3 is based on Figure 23The method of using TID to indicate UL low latency service and DL low latency service described in , and involves adding a new subfield indicating the LL ID mapped to the corresponding TID.

[0403] In this regard, it is assumed / presumed that the STA learns whether there is a mapping between the TID and the LL ID through the SCS negotiation process based on the QoS characteristic element. Instead of mapping one TID to one LL ID, one or more LL IDs can be mapped to one TID according to one or more transmission / reception requirements.

[0404] Figure 29 An example of a TID-based restricted TWT service information field according to an embodiment of the present disclosure is illustrated.

[0405] Reference Figure 29 The restricted TWT service information field included in the broadcast TWT parameter set field format includes the existing service information control subfield, the restricted TWT DL TID bitmap subfield, and the restricted TWT UL TID bitmap subfield, and can be defined to additionally include a TID mapping LL ID information (TID mapping LL ID information) subfield.

[0406] Specifically, the TID-mapping LL ID information subfield may consist of a TID subfield, a direction subfield, and a mapping LL ID subfield.

[0407] Here, the TID subfield may include only TIDs whose values in the restricted TWT DL TID bitmap subfield and the restricted TWT UL TID bitmap subfield are 1. Here, the TID having a value of 1 corresponds to an identifier of traffic indicated to be transmitted and received within the R-TWT SP.

[0408] Whether the data corresponding to the TID is DL or UL can be distinguished by the value of the direction subfield.

[0409] The Map LL ID subfield may indicate the LL ID mapped to the TID indicated by the TID subfield. The Map LL ID subfield may configure the value of the LL ID in an array format, or may indicate the LL ID in a bitmap format. That is, the format of the Map LL ID subfield is not limited to Figure 29 When the Map LL ID subfield indicates the LL ID in a bitmap format, the length of the subfield may be determined in units of octets based on the number of LL IDs defined by the AP (eg, M).

[0410] exist Figure 29In the TID-Mapping LL ID Information subfield, the length of the TID-Mapping LL ID Information subfield may vary depending on the length of the LL ID and the number of TIDs mapped to the LL ID. When the TID-Mapping LL ID Information subfield is configured by a STA, the length of this subfield may be configured in units of octets by using 0 (e.g., zero padding).

[0411] (Method 4)

[0412] Method 4 is a method for defining a new element indicating one or more LL IDs mapped to each TID.

[0413] For clarity in the following explanation, this new element is referred to as the TID Map LL ID element.

[0414] The TID mapping LL ID element may be additionally included in a frame containing a restricted TWT service information field indicating a low latency service within the R-TWTSP using an existing TID.

[0415] In this regard, it is assumed / presumed that the STA learns whether there is a mapping between the TID and the LL ID through the SCS negotiation process based on the QoS characteristic element. Instead of mapping one TID to one LL ID, one or more LL IDs based on one or more transmission / reception requirements can be mapped to one TID.

[0416] Figure 30 An example of a TID mapping LL ID element indicating an LL ID mapped to a TID according to an embodiment of the present disclosure is illustrated.

[0417] Reference Figure 30 The TID-mapped LL ID element may include a TID-mapped LL ID control field and a TID-mapped LL ID information field.

[0418] Specifically, the TID-mapping LL ID information field may consist of a TID subfield, a direction subfield, and a mapping LL ID subfield.

[0419] The TID subfield may indicate TIDs mapped to LL IDs from TID 0 to TID 7. TIDs included in the TID Map LL ID Information field may be indicated by a TID Existence Indicator subfield in a bitmap format within the TID Map LL ID Control field.

[0420] Whether the data of each TID is DL or UL can be distinguished by the value of the Direction subfield.

[0421] The Map LL ID subfield may indicate the LL ID mapped to the TID indicated by the TID subfield. The Map LL ID subfield may be configured with LL ID values in an array format, or may indicate the LL ID in a bitmap format. That is, the format of the Map LL ID subfield is not limited to Figure 30 When the Map LL ID subfield indicates the LL ID in a bitmap format, the length of the subfield may be determined based on the number (eg, M) of LL IDs defined by the AP.

[0422] exist Figure 30 In the TID-mapping LL ID information field, the length may vary depending on the length of the LL ID and the number of TIDs mapped to the LL ID. When the TID-mapping LL ID information field / subfield is configured by a STA, the length of the field / subfield may be configured in octets using 0s (e.g., zero padding).

[0423] The following description Figures 31 to 33 Various configuration examples corresponding to a new element indicating one or more LL IDs mapped to a TID (ie, a TID-mapping LL ID element), such as Figure 30 shown.

[0424] Figure 31 Another example of a TID mapping LL ID element indicating an LL ID mapped to a TID according to an embodiment of the present disclosure is illustrated.

[0425] Reference Figure 31 , which includes elements such as Figure 30 However, in addition to the TID existence indicator subfield, the LL ID mapping size subfield may be additionally configured in the TID mapping LL ID control field.

[0426] The LL ID Map Size subfield is defined to indicate the number of LL IDs defined by the AP, and based on this value, the length of the Map LL ID subfield in the TID Map LL ID Information field can be determined.

[0427] Figure 31 The illustrated TID-map LL ID element may be used when the STA does not have information on the total number of LL IDs defined by the AP.

[0428] Figure 32 Another example of a TID mapping LL ID element indicating an LL ID mapped to a TID according to an embodiment of the present disclosure is illustrated.

[0429] Reference Figure 32, the position of the direction subfield for indicating the direction of each TID (ie, DL or UL identification) may be arranged to correspond to Figure 30 and Figure 31 different.

[0430] Specifically, the purpose of indicating one or more LL IDs mapped to one TID is the same, but the direction subfield may be defined as being located within the TID mapping LL ID control field instead of Figure 30 and Figure 31 That is located after the TID subfield within the TID Mapping LL Information field. This may mean that only information for LL IDs mapped to the ULTID or DL TID indicated by the corresponding Direction subfield is included in the TID Mapping LL ID Information field.

[0431] exist Figure 32 In the TID-mapping LL ID information field / subfield, the length of the field / subfield may vary depending on the length of the LL ID and the number of TIDs mapped to the LL ID. When the TID-mapping LL ID information field / subfield is configured by the STA, the length of the field / subfield may be configured in octets using 0s (e.g., zero padding).

[0432] Figure 32 The illustrated structure may not be able to express both UL and DL for each TID, but Figure 30 and Figure 31 Compared with the structure of , the .DELTA.TID has the following advantages: when the directions of the TIDs are the same, the length of a TID is reduced by 1 bit.

[0433] Figure 33 Another example of a TID mapping LL ID element indicating an LL ID mapped to a TID according to an embodiment of the present disclosure is illustrated.

[0434] Reference Figure 33 ,like Figure 32 In the TID mapping LL ID control field, the direction subfield can be included in the TID mapping LL ID control field.

[0435] In this regard, Figure 32 In the case of the illustrated structure, each TID can only express one direction, namely UL or DL. Figure 33 In the case of the illustrated structure, the Direction subfield is defined to be located after the TID subfield in the TID Map LL ID Information field, so even a direction different from that indicated by the Direction subfield in the TID Map LL ID Control field can be expressed / indicated together.

[0436] That is, if the Direction subfield is not located after the TID subfield in the TID Mapping LL ID Information field, the TID indicated by the corresponding TID subfield follows the direction indicated by the Direction subfield in the TID Mapping LL ID Control field. On the other hand, if the Direction subfield is located after the TID subfield in the TID Mapping LL ID Information field, the TID of the corresponding TID subfield follows a direction different from the direction indicated by the Direction subfield in the TID Mapping LL ID Control field.

[0437] exist Figure 33 In the TID-mapping LL ID information field / subfield, the length of the field / subfield may vary depending on the length of the LL ID and the number of TIDs mapped to the LL ID. When the TID-mapping LL ID information field / subfield is configured by the STA, the length of the field / subfield may be configured in octets using 0s (e.g., zero padding).

[0438] Additionally, regarding the above method described in this embodiment, the present invention can be extended to a method in which the LL ID is not defined by the AP but is defined through a process of performing SCS negotiation between the AP and the STA (for example, a method of defining the LL ID based on the method in Embodiment 3).

[0439] For example, if the LL ID information is not defined by the AP and announced to the STA, but is shared through a separately addressed frame, the method of using the LL ID bitmap as in Method 1 may be difficult to apply, but the method of directly indicating the LL ID value itself in an array format as in Method 2 can be extended and applied to this case. In this case, the LL ID indicating information for low-latency services to be sent and received during the R-TWT SP can be shared between the AP and the STA through a separately addressed frame.

[0440] Additionally, the length of the restricted TWT DL LL ID list subfield and the restricted TWT UL LL ID list subfield can be determined based on the length of the LL ID and the number of LL IDs shared by the AP, and the length of the restricted TWT service information field included in the broadcast TWT parameter set field format can be determined based on this.

[0441] For another example, if the LL ID information is not defined by the AP and announced to the STA, but is shared via a separate addressing frame, the method of indicating the LL ID mapped to the TID as in Method 3 can be extended and applied. However, in this case, the TID-mapping LL ID information may consist of a TID subfield, a Direction subfield, and an LL ID List subfield. Here, the LL ID List subfield indicates the LL ID mapped to the TID indicated by the TID field.

[0442] Additionally, since it is difficult for a STA to know the LL ID length in advance, the traffic information control subfield may be configured to include an LL ID size subfield that may indicate the length of the LL ID in addition to the DL LL ID list valid subfield and the UL LL ID list valid subfield.

[0443] For another example, if LL ID information is not defined and announced by the AP to STAs, but is instead shared via individually addressed frames, the method described in Method 4, which utilizes a new element indicating the LL ID mapped to the TID (i.e., a TID-mapped LL ID element), can be extended and applied. However, in this case, the Mapped LL ID subfield included in the TID-mapped LL ID Information field in Method 4 can be replaced with an LL ID List subfield having the same / similar functionality, and the LL ID Mapping Size subfield included in the TID-mapped LL ID Control field can be replaced with an LL ID Size subfield having the same / similar functionality. In this regard, the length of the Mapped LL ID subfield can be based on the length of the LL ID defined by the method described in Embodiment 3.

[0444] Below, R-TWT operations utilizing broadcast TWT elements and / or new elements (e.g., TID mapping LL ID elements) including restricted TWT service information proposed in the present disclosure (e.g., the restricted TWT service information field / subfield in the method of embodiment 4) are illustrated.

[0445] Figure 34 An example of R-TWT operation based on the restricted TWT service information field according to an embodiment of the present disclosure is illustrated.

[0446] Reference Figure 34 STA 1 to STA 3 correspond to R-TWT SP (RSP) STAs that support R-TWT performed by the AP, and a TWT establishment process can be performed based on a TWT request frame sent by STA 3 and a TWT response frame as a response of the AP to the TWT request frame. Through such a TWT establishment process, RSP can be allocated to STA 3.

[0447] At this time, the AP can notify STA 3 of the following information through the beacon frame: the R-TWT SP assigned to it can send and receive low-latency services corresponding to LL IDs [0, 4, 5]. STA 2 can identify this information through the broadcast TWT element and / or TID-mapped LL ID element included in the beacon.

[0448] In this regard, Figure 34As shown, if the LL ID of the low-latency service to be sent and received by STA 2 is the same as the LL ID of the low-latency service to be sent and received by STA 3 (i.e., LL ID[0,4,5]), STA 2 can send a TWT request frame to the AP to request membership of the R-TWT (i.e., RSP) assigned to STA 3.

[0449] Figure 35 Another example of R-TWT operation based on the restricted TWT service information field according to an embodiment of the present disclosure is illustrated.

[0450] Reference Figure 35 ,based on Figure 34 STA 2, which has become the same R-TWT member as STA 3, can transmit and receive frames corresponding to LL ID [0, 4, 5] with the AP before this RSP.

[0451] In this case, the transmission and reception of frames corresponding to LL IDs [0, 4, 5] can continue until the RSP without stopping STA 2's TXOP. For example, the RSP (originally) allocated to STA 3 may be extended to some extent due to this TXOP. That is, the start time and / or end time of this RSP may be changed in consideration of STA 2's TXOP.

[0452] Figure 36 Another example of R-TWT operation based on the restricted TWT service information field according to an embodiment of the present disclosure is illustrated.

[0453] Reference Figure 36 STA 1 to STA 3 correspond to R-TWT SP (RSP) STAs that support R-TWT performed by the AP, and a TWT establishment process can be performed based on a TWT request frame sent by STA 3 and a TWT response frame as a response of the AP to the TWT request frame. Through such a TWT establishment process, RSP can be allocated to STA 3.

[0454] At this time, the AP can notify STA 3 of the following information through the beacon frame: the R-TWT SP assigned to it can send and receive low-latency services corresponding to LL ID [0, 4, 5]. Other STAs (i.e., STA 1 and STA 2) can identify this information through the broadcast TWT element and / or TID mapping LL ID element included in the beacon.

[0455] In this regard, the STA may be configured to determine the priority between the LL IDs based on whether there is a priority between the LL IDs or based on the transmission requirement conditions mapped to the LL IDs (e.g., classification conditions based on QoS characteristic elements, etc.). In this case, the STA may determine / identify whether a frame having a higher priority or a lower priority than the low-latency service (e.g., the low-latency service corresponding to LL ID [0, 4, 5]) to be transmitted / received during the allocated RSP is being transmitted / received before the RSP.

[0456] If the LL ID corresponding to the low-latency service to be sent and received during the RSP (e.g., LL ID [0, 4, 5]) has a lower priority than the LL ID corresponding to the low-latency service to be sent and received before the RSP (e.g., LLID [0, 1, 2]), the start time of STA 3's RSP is postponed in the time domain until after the TXOP of STA 1 ends, and the end time of the RSP may also be postponed.

[0457] Figure 36 The illustrated method has the advantage of being able to protect data transmitted and received before the RSP start timing while protecting the RSP duration.

[0458] Implementation 5

[0459] This embodiment relates to a case where the number of identifiers (ie, TIDs) used to identify / classify services or the range of TIDs is expanded (eg, TIDs are expanded to 16, ie, TID 0 to TID 15).

[0460] That is, although the previous embodiments described in this disclosure have been described assuming that a maximum of eight TIDs (e.g., TID 0 to TID 7) are set / defined, they can also be applied with extension and some changes when the number of TIDs is extended to more than eight (e.g., TID 0 to TID 15 are set / supported).

[0461] For example, assuming that values from TID 0 to TID 15 are used to indicate low-latency services, the above-mentioned definition and / or method of utilizing LL ID may be applied.

[0462] in this case, Figure 23 、 Figure 29The length of the subfield indicating the TID (e.g., the restricted TWT DL TID bitmap field and the restricted TWT UL TID bitmap field) in the restricted TWT service information field in the broadcast TWT element of the broadcast TWT, etc., can be extended from the existing 8 bits (i.e., 1 octet) to 16 bits (i.e., 2 octets). Therefore, the length of the restricted TWT service information field can be extended to a maximum of 5 octets.

[0463] In this regard, when the number of LL IDs is greater than 8 and less than or equal to 16 (e.g., Figure 27 ), the length of the restricted service information field is also at most 5 octets, so it has the following advantages: the sending and receiving requirements of low-latency services sent and received during the RSP can be shared in detail to the associated STAs supporting R-TWT without additional octets.

[0464] Additionally or alternatively, regarding method 4 of embodiment 4, this method can be extended and applied even when using TIDs 0 to 15. For example, the TID subfield including the TID mapped to the LLID can be set / defined considering TIDs from TID 0 to TID 15. In this regard, Figures 30 to 33 The length of the TID presence indicator field in the

[0054] field can be expanded from the existing 8 bits to 16 bits, and each TID subfield can be expanded from the existing 3 bits to 4 bits. Additionally, in this case, Figure 31 The length of the LL ID Mapping Size subfield in the LLID to Link Mapping Control field can be changed to 5 bits.

[0465] Additionally or alternatively, for the individual LL ID definition scheme described above in the present disclosure (i.e., where the LL ID information is not defined by the AP and announced to the STA, but is shared via a separately addressed frame), a TID extension scheme similar to the above may be applied (e.g., utilizing TID 0 to TID 15).

[0466] Below, we will refer to Figure 37 and Figure 38 The operation of the STA according to the above-described embodiment of the present disclosure is described.

[0467] Right now, Figure 37 and Figure 38 The examples of may correspond to some of the various examples of the present disclosure. For example, in Figure 37 and Figure 38 In the example, the first STA may correspond to a non-AP STA, and the second STA may correspond to an AP.

[0468] Figure 37 An operation flowchart of a first STA according to an embodiment of the present disclosure is illustrated.

[0469] Reference Figure 37 , the first STA can receive an R-TWT related frame from the second STA, which R-TWT related frame includes information on an LL related ID (e.g., LL ID in the present disclosure) for classifying low-latency services (S3710).

[0470] For example, the R-TWT related frame may correspond to a frame related to R-TWT establishment / negotiation, a frame related to announcing R-TWT SP, and the like.

[0471] In this regard, the information for the LL-related ID may be indicated based on a specific field of a TWT element within an R-TWT-related frame or a specific element within an R-TWT-related frame.

[0472] For example, as described above in the present disclosure, the specific field may correspond to the restricted TWT service information field included in the broadcast TWT parameter set field within the TWT element.

[0473] Additionally or alternatively, as described above in the present disclosure (for example, method 1 of embodiment 4, etc.), the information for the LL-related ID may include one or more of the following items: a first bitmap subfield, which is defined as indicating the LL-related ID corresponding to the DL low-latency service; or a second bitmap subfield, which is defined as indicating the LL-related ID corresponding to the UL low-latency service.

[0474] In this regard, the length of the first bitmap subfield and the length of the second bitmap subfield can be variably set based on the number of LL-related IDs defined by the second STA (e.g., AP). As a specific example, when the number of LL-related IDs is greater than or equal to 1 and less than or equal to 4, the length of the first bitmap subfield and the length of the second bitmap subfield can each be set to 4 bits, and the specific field can have a length of up to 2 octets. When the number of LL-related IDs is greater than 4 and less than or equal to 8, the length of the first bitmap subfield and the length of the second bitmap subfield can each be set to 1 octet, and the specific field can have a length of up to 3 octets. When the number of LL-related IDs is greater than 8 and less than or equal to 16, the length of the first bitmap subfield and the length of the second bitmap subfield can each be set to 2 octets, and the specific field can have a length of up to 5 octets.

[0475] Additionally or alternatively, as described above in the present disclosure (e.g., method 2 of embodiment 4, etc.), the information of the LL-related ID may include one or more of the following items: a first ID list subfield (e.g., array format), which is defined to indicate the LL-related ID corresponding to the DL low-latency service; or a second ID list subfield (e.g., array format), which is defined to indicate the LL-related ID corresponding to the UL low-latency service.

[0476] In this regard, the information regarding the LL-related ID may further include information indicating the length of the LL-related ID. Based on this, the length of the First ID List subfield may be variably set based on the length of the LL-related ID and the number of LL-related IDs included in the First ID List subfield. Additionally, the length of the Second ID List subfield may be variably set based on the length of the LL-related ID and the number of LL-related IDs included in the Second ID List subfield.

[0477] Additionally or alternatively, when information for an LL-related ID is indicated by a specific field, as described above in the present disclosure (e.g., method 3 of embodiment 4, etc.), the information for the LL-related ID may include an information subfield defined as indicating the LL-related ID mapped to the service ID (TID) indicated in the specific field.

[0478] In this regard, the corresponding TID may be indicated by at least one of the DL TID bitmap subfield or the UL TID bitmap subfield included in the specific field. Additionally, for each indicated TID, the corresponding information subfield may include first information indicating the TID, second information indicating the direction of data based on the corresponding TID, and third information indicating the LL-related ID mapped to the corresponding TID. Here, the third information may be based on one of the following: a list format (e.g., an array format) including one or more LL-related ID values; or a bitmap format indicating one or more LL-related IDs.

[0479] Additionally or alternatively, when information of the LL-related ID is indicated by a specific element, as described above in the present disclosure (e.g., method 4 of embodiment 4, etc.), the specific element may include: a first field including information indicating one or more TIDs mapped to the LL-related ID; and a second field indicating information regarding a mapping between the one or more TIDs and the LL-related ID.

[0480] In this regard, for each indicated TID, the second field may include first information indicating the TID, second information indicating the direction of data based on the corresponding TID, and third information indicating the LL-related ID mapped to the corresponding TID. Additionally, the first field may further include information indicating the number of LL-related IDs defined by the second STA (e.g., AP).

[0481] Additionally or alternatively, the first field may further include information indicating the direction of data based on one or more TIDs, and for each indicated TID, the second field may include first information indicating the TID and second information indicating the LL-related ID mapped to the corresponding TID. Here, the second information may be based on one of the following: a list format (e.g., an array format) including one or more LL-related ID values; or a bitmap format indicating one or more LL-related IDs. In this regard, if the second field further includes third information indicating the direction of data based on the corresponding TID, the direction indicated by the third information may be set to be different from the direction indicated by the first field, and the direction indicated by the third information may be applied preferentially.

[0482] In the R-TWT SP related to / based on the above-mentioned R-TWT related frame, the first STA can perform frame exchange with the second STA based on the service according to the corresponding LL-related ID (S3720).

[0483] exist Figure 37 The method performed by the first STA described in the example can be performed by Figure 1 The first device (100) performs. For example, Figure 1 One or more processors (102) of the first device (100) may be configured to receive an R-TWT related frame from a second STA (200) through one or more transceivers (106), the R-TWT related frame including information for an LL related ID, and perform frame exchange with the second STA (200) based on a service according to the LL related ID. In addition, one or more memories (104) of the first device (100) may store commands that, when executed by the one or more processors (102), are used to perform Figure 37 or the methods described in the examples above.

[0484] Figure 38 An operation flowchart of a second STA according to an embodiment of the present disclosure is illustrated.

[0485] Reference Figure 38, the second STA can send an R-TWT related frame to the first STA, which R-TWT related frame includes information about an LL related ID (e.g., the LL ID in the present disclosure) used to classify low-latency services (S3810).

[0486] For example, the R-TWT related frame may correspond to a frame related to R-TWT establishment / negotiation, a frame related to announcing R-TWT SP, and the like.

[0487] In this regard, the information for the LL-related ID may be indicated based on a specific field of a TWT element within an R-TWT-related frame or a specific element within an R-TWT-related frame.

[0488] Thereafter, within the R-TWT SP associated with / based on the R-TWT related frame, the second STA may perform frame exchange with the first STA based on the service according to the corresponding LL-related ID (S3820).

[0489] Figure 38 Detailed description of the information on LL related IDs, specific fields included in the TWT elements in the R-TWT related frames, specific elements in the R-TWT related frames, etc. Figure 37 Those described in the example are the same, so redundant description is omitted.

[0490] exist Figure 38 The method performed by the second STA described in the example can be performed by Figure 1 The second device (200) is executed. For example, Figure 1 The one or more processors (202) of the second device (200) may be configured to transmit an R-TWT related frame to the first STA (100) through the one or more transceivers (206), the R-TWT related frame including information for the LL related ID, and perform frame exchange with the first STA (100) based on the service according to the LL related ID. In addition, the one or more memories (204) of the second device (200) may store commands that, when executed by the one or more processors (202), are used to perform Figure 38 or the methods described in the examples above.

[0491] In existing wireless LAN systems, SCS procedures using SCS IDs and R-TWT procedures related to general low-latency services have already been defined. In contrast, the R-TWT element proposed in this disclosure has a new feature that indicates a specific LL ID within the element. This feature enables the sending and receiving of priority low-latency / delay-sensitive services within the RSP (R-TWT SP).

[0492] The above-mentioned embodiments 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, an embodiment 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.

[0493] 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 changes within the scope of equivalents of the present disclosure are included within the scope of the present disclosure.

[0494] 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 the 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 to 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.

[0495] Industrial Applicability

[0496] The method proposed in the present disclosure is mainly described based on an example of application to a system based on IEEE 802.11, but can be applied to various WLANs or wireless communication systems other than the system based on IEEE 802.11.

Claims

1. A method performed by a first station (STA) in a wireless LAN system, the method comprising: receiving a restricted target wake-up time R-TWT related frame from a second STA, the R-TWT related frame including information on an LL correlation ID for classifying a low-latency LL service; as well as performing frame exchange with the second STA based on the service according to the LL-related ID within the R-TWT service period SP based on the R-TWT related frame, The information for the LL-related ID is indicated based on a specific field of a TWT element in the R-TWT-related frame or a specific element in the R-TWT-related frame.

2. The method according to claim 1, in, The specific field corresponds to the restricted TWT service information field included in the broadcast TWT parameter set field within the TWT element.

3. The method according to claim 1, in, The information for the LL-related ID includes at least one of the following items: a first bitmap subfield, the first bitmap subfield being defined to indicate an LL-related ID corresponding to a DL low-latency service; or a second bitmap subfield, the second bitmap subfield being defined to indicate an LL-related ID corresponding to a UL low-latency service.

4. The method according to claim 3, in, The length of the first bitmap subfield and the length of the second bitmap subfield are variably set based on the number of defined LL-related IDs.

5. The method according to claim 4, in, based on the number of the LL-related IDs being greater than or equal to 1 and less than or equal to 4, the length of the first bitmap subfield and the length of the second bitmap subfield are respectively set to 4 bits, and the length of the specific field is set to a maximum of 2 octets, wherein, based on the number of the LL-related IDs being greater than 4 and less than or equal to 8, the length of the first bitmap subfield and the length of the second bitmap subfield are each set to 1 octet, and the length of the specific field is set to a maximum of 3 octets, and Wherein, based on the number of the LL-related IDs being greater than 8 and less than or equal to 16, the length of the first bitmap subfield and the length of the second bitmap subfield are respectively set to 2 octets, and the length of the specific field is set to a maximum of 5 octets.

6. The method according to claim 1, in, The information for the LL-related ID includes at least one of the following items: a first ID list subfield, which is defined as indicating an LL-related ID corresponding to a DL low-latency service; or a second ID list subfield, which is defined as indicating an LL-related ID corresponding to a UL low-latency service.

7. The method according to claim 6, in, The information for the LL-related ID further includes information indicating the length of the LL-related ID, wherein the length of the first ID list subfield is variably set based on the length of the LL-related ID and the number of the LL-related IDs included in the first ID list subfield, and The length of the second ID list subfield is variably set based on the length of the LL-related ID and the number of the LL-related IDs included in the second ID list subfield.

8. The method according to claim 1, in, Based on the information for the LL-related ID being indicated by the specific field, The information for the LL-related ID includes an information subfield defined to indicate the LL-related ID mapped to the service ID TID indicated by the specific field.

9. The method according to claim 8, in, The TID is indicated by at least one of a DL TID bitmap subfield or a UL TID bitmap subfield included in the specific field, and For each indicated TID, the information subfield includes first information indicating the TID, second information indicating a direction of data based on the corresponding TID, and third information indicating an LL-related ID mapped to the corresponding TID.

10. The method according to claim 9, in, The third information is based on one of: a list format including one or more LL-related ID values; or a bitmap format indicating one or more LL-related IDs.

11. The method according to claim 1, in, Based on the information for the LL-related ID being indicated by the specific element, The specific element includes: a first field including information indicating one or more TIDs mapped to the LL-related ID; and a second field indicating information for mapping between the one or more TIDs and the LL-related ID.

12. The method according to claim 11, in, For each indicated TID, the second field includes first information indicating the TID, second information indicating a direction of data based on the corresponding TID, and third information indicating an LL-related ID mapped to the corresponding TID.

13. The method according to claim 11, in, The first field also includes information indicating the number of defined LL-related IDs.

14. The method according to claim 11, in, The first field also includes information indicating a direction of data based on the one or more TIDs, and For each indicated TID, the second field includes first information indicating the TID and second information indicating the LL-related ID mapped to the corresponding TID.

15. The method according to claim 14, in, Based on the fact that the second field also includes third information indicating the direction of the data based on the corresponding TID, The direction indicated by the third information is set to be different from the direction indicated by the first field, and the direction indicated by the third information is preferentially applied.

16. A device for a first station (STA) 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 a restricted target wake time R-TWT related frame from a second STA, the R-TWT related frame including information on an LL correlation ID for classifying a low-latency LL service; and performing frame exchange with the second STA based on the service according to the LL-related ID within the R-TWT service period SP based on the R-TWT related frame, The information for the LL-related ID is indicated based on a specific field of a TWT element in the R-TWT-related frame or a specific element in the R-TWT-related frame.

17. A method performed by a second station (STA) in a wireless LAN system, the method comprising: Sending a restricted target wake-up time R-TWT related frame to a first STA, where the R-TWT related frame includes information about an LL related ID for classifying a low-latency LL service; as well as performing frame exchange with the first STA based on the service according to the LL-related ID within the R-TWT service period SP based on the R-TWT related frame, The information for the LL-related ID is indicated based on a specific field of the TWT element in the R-TWT-related frame or a specific element in the R-TWT-related frame.

18. A device for a second station (STA) 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 a restricted target wake-up time R-TWT related frame to the first STA, wherein the R-TWT related frame includes information on an LL related ID for classifying a low-latency LL service; and performing frame exchange with the first STA based on the service according to the LL-related ID within the R-TWT service period SP based on the R-TWT related frame, The information for the LL-related ID is indicated based on a specific field of the TWT element in the R-TWT-related frame or a specific element in the R-TWT-related frame.

19. A processing unit configured to control a station (STA) in a wireless local area network (WLAN) system, the processing unit comprising: at least one processor; as well as At least one computer memory operatively connected to the at least one processor and storing instructions for executing the method according to any one of claims 1 to 15 upon being executed by the at least one processor.

20. 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 in a wireless local area network (WLAN) system to perform the method according to any one of claims 1 to 15.

Images