Methods and apparatus for transmitting and receiving services in a wireless LAN system

Abstract

This invention discloses a method and apparatus for operation in a wireless LAN system. According to embodiments of this disclosure, a method performed by a first station (STA) in a wireless LAN system includes the following steps: the first station (TA) receiving a first physical layer protocol data unit (PPDU) including a polling frame from an access point (AP); based on the polling frame, the first STA transmitting a first frame related to a first low-latency service (LLT) to the AP via a first channel including a primary channel; and the first STA transmitting the first LLT to the AP within a transmission opportunity of the AP, wherein the polling frame may include information related to the maximum bandwidth of the channel used for LLT transmission.

Description

Technical Field

[0001] This disclosure relates to a method and apparatus for transmitting and receiving services and service-related information in a wireless local area network (WLAN) system. Background Technology

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

[0003] To provide a more robust wireless communication environment, enhancement technologies for EHT (Extreme High Throughput) are being discussed. For example, technologies for supporting multi-access point (AP) coordination and multiple-input multiple-output (MIMO) to increase bandwidth, effectively utilize multiple bands, and increase spatial flow are being investigated. In particular, various technologies are being explored to support low-latency or real-time services. Furthermore, new technologies to support Ultra-High Reliability (UHR) through improvements or extensions to EHT technologies are being discussed. Summary of the Invention

[0004] [Technical Issues]

[0005] The technical problem addressed in this disclosure relates to a method and apparatus for transmitting and receiving services in a wireless LAN system.

[0006] The technical problem of this disclosure relates to a method and apparatus for transmitting information related to preemption operations in a wireless LAN system for low-latency services.

[0007] The technical objectives achieved through this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the following description other technical objectives not described herein.

[0008] [Technical Solution]

[0009] According to one embodiment of this disclosure, a method performed by a first station (STA) in a wireless LAN system may include the first station (TA) receiving a first physical layer protocol data unit (PPDU) including a polling frame from an access point (AP); based on the polling frame, the first STA sending a first frame related to a first low-latency service (LLT) to the AP via a first channel including a master channel; and the first STA sending the first LLT to the AP within a transmission opportunity of the AP, wherein the polling frame may include information related to the maximum bandwidth of the channel used for LLT transmission.

[0010] According to another embodiment of this disclosure, a method performed by an access point (AP) in a wireless LAN system may include sending a first physical layer protocol data unit (PPDU) including a polling frame to at least one station (STA); receiving a first frame associated with a first low-latency service (LLT) from a first STA among the at least one STA via a first channel including a master channel based on the polling frame; and receiving the first LLT from the first STA within a transmission opportunity of the AP, wherein the polling frame may include information related to the maximum bandwidth of the channel used for LLT transmission.

[0011] [Technical Effects]

[0012] According to various embodiments of this disclosure, a method and apparatus for transmitting and receiving services in a wireless LAN system can be provided.

[0013] The technical problem of the present invention relates to a method and apparatus for transmitting information for preemption operations related to low-latency services in a wireless LAN system.

[0014] The effects achievable by this disclosure are not limited to those described above, and those skilled in the art can clearly understand other effects not described herein through the following description. Attached Figure Description

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

[0016] Figure 1 The figure shows a block configuration diagram of a wireless communication device according to an embodiment of the present disclosure.

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

[0018] Figure 3 It is a diagram used to describe the link setup process to which this disclosure can be applied.

[0019] Figure 4 It is a diagram used to describe the retreat process to which this disclosure can be applied.

[0020] Figure 5 This is a diagram used to describe the CSMA / CA-based frame transmission operation to which this disclosure can be applied.

[0021] Figure 6 This is a diagram illustrating an example of a frame structure that can be used in a WLAN system to which this disclosure may be applied.

[0022] Figure 7 This is a diagram illustrating an example of a PPDU that can be applied in the IEEE 802.11 standard of this disclosure.

[0023] Figure 8 This is a diagram illustrating an exemplary format of the trigger frame to which the present disclosure can be applied.

[0024] Figure 9 This is a diagram illustrating issues related to LLT transmission in DL (downlink) TXOP.

[0025] Figure 10 This is a diagram illustrating issues related to LLT transmission in UL (uplink) TXOP.

[0026] Figure 11 This is a flowchart illustrating the operation of a first STA according to an embodiment of the present disclosure.

[0027] Figure 12 This is a flowchart illustrating the operation of an AP according to an embodiment of the present disclosure.

[0028] Figure 13 This is a diagram illustrating a method for STA and AP to transmit and receive LLT according to an embodiment of the present disclosure.

[0029] Figure 14 This is a diagram illustrating a process for transmitting LLTI using LLT polling frames according to an embodiment of the present disclosure.

[0030] Figure 15 This is a diagram illustrating a method for sending LLTI via LLT polling frames according to an embodiment of the present disclosure.

[0031] Figure 16 This is a diagram illustrating a method for sending LLTI using a PHY header according to an embodiment of the present disclosure.

[0032] Figure 17 This is a diagram illustrating a method for sending LLTI using a PHY header according to an embodiment of the present disclosure.

[0033] Figure 18 This is a diagram illustrating a method for sending LLTI using a PHY header according to an embodiment of the present disclosure.

[0034] Figure 19 This is a diagram illustrating a BSR triggering method for an LL STA according to an embodiment of the present disclosure.

[0035] Figure 20 This is a diagram illustrating a response method of LL STA based on LLTI according to an embodiment of the present disclosure.

[0036] Figure 21 This is a diagram illustrating a response method of LL STA based on LLTI according to an embodiment of the present disclosure. Detailed Implementation

[0037] In the following, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed with reference to the drawings is intended to describe exemplary embodiments of the present disclosure and not to represent the only embodiments in which the present disclosure may be practiced. The following detailed description includes specific details to provide a complete understanding of the present disclosure. However, those skilled in the art will recognize that the present disclosure may be practiced without these specific details.

[0038] In some cases, known structures and devices may be omitted, or they may be shown in block diagram form based on the core functions of each structure and device in order to prevent ambiguity of the concepts in this disclosure.

[0039] In this disclosure, when an element is referred to as “connected,” “combined,” or “linked” to another element, it can include both indirect and direct connections where another element exists therebetween. Furthermore, in this disclosure, the terms “comprising” or “having” specify the presence of the mentioned features, steps, operations, components, and / or elements, but do not exclude the presence or addition of one or more other features, stages, operations, components, elements, and / or groups thereof.

[0040] In this invention, terms such as "first" and "second" are used only to distinguish one element from another and are not used to limit the elements. Unless otherwise stated, they do not limit the order or importance of the elements. Therefore, within the scope of this disclosure, a first element in one embodiment may be referred to as a second element in another embodiment, and similarly, a second element in one embodiment may be referred to as a first element in another embodiment.

[0041] The terminology used in this disclosure is for the purpose of describing particular embodiments and not for limiting the claims. As used in the description of the embodiments and the appended claims, the singular forms are intended to include the plural forms unless the context clearly indicates otherwise. The term “and / or” as used in this disclosure may refer to one of the associated enumerations, or is intended to refer to and include any and all possible combinations of two or more of them. Furthermore, unless otherwise stated, the “ / ” between words in this disclosure has the same meaning as “and / or”.

[0042] The examples disclosed herein can be applied to various wireless communication systems. For example, the examples disclosed herein can be applied to wireless LAN systems. For example, the examples disclosed herein can be applied to wireless LANs based on the IEEE 802.11a / g / n / ac / ax standards. Furthermore, the examples disclosed herein can be applied to wireless LANs based on the newly proposed IEEE 802.11be (or EHT) standard. The examples disclosed herein can be applied to wireless LANs based on the IEEE 802.11be version 2 standard, corresponding to the additional enhancements of the IEEE 802.11be version 1 standard. Additionally, the examples disclosed herein can be applied to next-generation standards-based wireless LANs following IEEE 802.11be. Furthermore, the examples disclosed herein can be applied to cellular wireless communication systems. For example, it can be applied to cellular wireless communication systems based on 3GPP standards using Long Term Evolution (LTE) technology and 5G New Radio (NR) technology.

[0043] The technical features that can be applied to examples of this disclosure will be described below.

[0044] Figure 1 The figure shows a block diagram of a wireless communication device according to an embodiment of the present disclosure.

[0045] Figure 1 The first device 100 and the second device 200 illustrated in the diagram can be replaced by various terms, such as terminal, wireless device, wireless transceiver unit (WTRU), user equipment (UE), mobile station (MS), user terminal (UT), mobile subscriber station (MSS), mobile subscriber unit (MSU), subscriber station (SS), advanced mobile station (AMS), wireless terminal (WT), or simple user, etc. Furthermore, the first device 100 and the second device 200 can include access point (AP), base station (BS), fixed station, node B, base transceiver system (BTS), and network. It can be replaced by various terms such as artificial intelligence (AI) system, roadside unit (RSU), repeater, router, relay, and gateway.

[0046] Figure 1 The devices 100 and 200 shown in the diagram can be referred to as stations (STAs). For example, Figure 1The devices 100 and 200 illustrated in the figure can be referred to by various terms such as transmitting device, receiving device, transmitting STA, and receiving STA. For example, STA 110 and 200 can perform an access point (AP) role or a non-AP role. That is, in this disclosure, STA 110 and 200 can perform AP and / or non-AP functions. When STA 110 and 200 perform AP functions, they can be simply referred to as AP, and when STA 110 and 200 perform non-AP functions, they can be simply referred to as STA. In addition, in this disclosure, AP can also be referred to as APSTA.

[0047] refer to 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 may include interfaces for the Media Access Control (MAC) layer and Physical Layer (PHY) conforming to the IEEE 802.11 standard.

[0048] Furthermore, the first device 100 and the second device 200 can additionally support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, etc.) besides wireless LAN technology. Additionally, the devices disclosed herein can be implemented in various devices, such as mobile phones, vehicles, personal computers, augmented reality (AR) devices, virtual reality (VR) devices, etc. Furthermore, the STA of this specification can support various communication services, such as voice calls, video calls, data communication, autonomous driving, machine-type communication (MTC), machine-to-machine (M2M), device-to-device (D2D), IoT (Internet of Things), etc.

[0049] The first device 100 may include one or more processors 102 and one or more memories 104, and may additionally 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, proposals, methods, and / or operation flowcharts disclosed herein. For example, the processor 102 may transmit a wireless signal including the first information / signal via the transceiver 106 after generating a first information / signal by processing information in the memory 104. Additionally, the processor 102 may receive a wireless signal including a second information / signal via the transceiver 106, and then store information obtained through signal processing of the second information / signal in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software code including instructions for performing all or part of the processes controlled by the processor 102 or for performing the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed herein. Here, processor 102 and memory 104 may be part of a communication modem / circuit / chip designed to implement wireless LAN technologies (e.g., LTE 802.11 series). Transceiver 106 may be connected to processor 102 and may transmit and / or receive wireless signals via one or more antennas 108. Transceiver 106 may include a transmitter and / or a receiver. Transceiver 106 may be used with an RF (radio frequency) unit. In this disclosure, "device" may refer to a communication modem / circuit / chip.

[0050] The second device 200 may include one or more processors 202 and one or more memories 204, and may additionally 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, proposals, methods, and / or operation flowcharts disclosed 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. Additionally, the processor 202 may receive wireless signals including fourth information / signals via the transceiver 206, and then store information obtained through 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 performing all or part of the processes controlled by the processor 202 or for performing the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this disclosure. Here, processor 202 and memory 204 may be part of a communication modem / circuit / chip designed to implement wireless LAN technologies (e.g., IEEE 802.11 series). Transceiver 206 may be connected to processor 202 and may transmit and / or receive wireless signals via one or more antennas 208. Transceiver 206 may include a transmitter and / or a receiver. Transceiver 206 may be used with an RF unit. In this disclosure, "device" may refer to a communication modem / circuit / chip.

[0051] The hardware components of devices 100 and 200 will be described in more detail below. However, they are not limited thereto, but one or more protocol layers may be implemented by one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as PHY and MAC). One or more processors 102 and 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, proposals, methods, and / or operation flowcharts disclosed in this disclosure. One or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this disclosure. One or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, processes, proposals, and / or methods disclosed in this disclosure to provide them to one or more transceivers 106 and 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 in accordance with the descriptions, functions, processes, proposals, methods, and / or operation flowcharts disclosed in this disclosure.

[0052] One or more processors 102, 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102, 202 may be implemented by hardware, firmware, software, or a combination thereof. In examples, one or more ASICs (Application-Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field-Programmable Gate Arrays) may be included in one or more processors 102, 202. The descriptions, functions, processes, proposals, methods, and / or operation flowcharts included in this disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, processes, functions, etc. Firmware or software configured to execute the descriptions, functions, processes, proposals, methods, and / or operation flowcharts included in this disclosure may be included in one or more processors 102, 202 or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions, functions, processes, proposals, methods, and / or operation flowcharts included in this invention may be implemented by firmware or software in the form of code, commands, and / or command sets.

[0053] One or more memories 104, 204 may be connected to one or more processors 102, 202 and are capable of storing data, signals, messages, information, programs, code, instructions, and / or commands in various forms. One or more memories 104, 204 may be configured with ROM, RAM, EPROM, flash memory, hard disk drive, registers, cache memory, computer-readable storage media, and / or combinations thereof. One or more memories 104, 204 may be located internally and / or externally to one or more processors 102, 202. Furthermore, one or more memories 104, 204 may be connected to one or more processors 102, 202 via various technologies such as wired or wireless connections.

[0054] One or more transceivers 106, 206 can transmit user data, control information, wireless signals / channels, etc., mentioned in the methods and / or operation flowcharts of this disclosure to one or more other devices. One or more transceivers 106, 206 can receive user data, control information, wireless signals / channels, etc., mentioned in the descriptions, functions, processes, proposals, methods, and / or operation flowcharts included in this disclosure from one or more other devices. For example, one or more transceivers 106, 206 can be connected to one or more processors 102, 202 and can transmit and receive wireless signals. For example, one or more processors 102, 202 can control one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Furthermore, one or more processors 102, 202 can control one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. Furthermore, one or more transceivers 106, 206 may be connected to one or more antennas 108, 208, and the 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, proposals, methods, and / or operation flowcharts included in this disclosure via one or more antennas 108, 208. In this invention, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). The one or more transceivers 106, 206 may process the received wireless signals / channels, etc., by converting them from RF band signals to baseband signals using one or more processors 102, 202. The one or more transceivers 106, 206 may convert the user data, control information, wireless signals / channels, etc., processed by using one or more processors 102, 202 from baseband signals to RF band signals. Therefore, the one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

[0055] For example, one of STAs 100 and 200 can perform the expected operation of an AP, and the other of STAs 100 and 200 can perform the expected operation of a non-AP STA. Figure 1 Transceivers 106 and 206 can perform transmission and reception operations of signals (e.g., packet or physical layer protocol data units (PPDUs) conforming to IEEE 802.11a / b / g / n / ac / ax / be). Furthermore, in this disclosure, the operations of generating transmit / receive signals or performing data processing or calculations on transmit / receive signals in advance by various STAs can be performed by… Figure 1 Processors 102 and 202 perform the following operations: For example, examples of generating transmit / receive signals or performing data processing or calculations on transmit / receive signals in advance may include 1) determining / acquiring / configuring / calculating / decoding / encoding bit information of fields (signals (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 the 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 the fields (SIG, STF, LTF, data, etc.) included in the PPDU action; 4) power control operations and / or power-saving operations applied to the STA; and 5) operations related to determining / acquiring / configuring / calculating / encoding the ACK signal. Additionally, in the following examples, various information used by various STAs to determine / acquire / configure / calculate / decode / encode transmitted and received signals (e.g., information related to fields / subfields / control fields / parameters / power, etc.) can be stored. Figure 1 In memory 104 and 204.

[0056] In the following text, downlink (DL) can refer to a link used for communication from an AP STA to a non-AP STA, and DL PPDUs / packets / signals can be sent and received via DL. In DL communication, the transmitter can be part of an AP STA, and the receiver can be part of a non-AP STA. Uplink (UL) can refer to a link used for communication from a non-AP STA to an AP STA, and UL PPDUs / packets / signals can be sent and received via UL. In UL communication, the transmitter can be part of a non-AP STA, and the receiver can be part of an AP STA.

[0057] Figure 2 This is a diagram illustrating an exemplary structure of a wireless LAN system to which this disclosure can be applied.

[0058] A wireless LAN system can be structured by multiple components. Wireless LANs that support STA mobility transparent to upper layers can be provided through the interaction of these components. The Basic Services Set (BSS) corresponds to the basic building blocks of a wireless LAN. Figure 2 An example is shown where there are two BSSs (BSS1 and BSS2) and two STAs are included as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). Figure 2 The ellipse representing the BSS can also be interpreted as representing the coverage area within the corresponding BSS where STAs maintain communication. This area can be called the Basic Service Area (BSA). When a STA moves out of the BSA, it cannot directly communicate with other STAs within the BSA.

[0059] If we do not consider Figure 2 The DS shown represents the most basic type of BSS in a wireless LAN, which is the Independent BSS (IBSS). For example, an IBSS can have a minimal form containing only two STAs. For instance, assuming other components are omitted, BSS1 containing only STA1 and STA2, or BSS2 containing only STA3 and STA4, can respectively correspond to representative examples of IBSS. This configuration is possible when STAs can communicate directly without an AP. Furthermore, in this type of wireless LAN, it is not pre-configured but can be configured when a LAN is needed, and this can be called a self-organizing network. Because an 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 can consist of mobile STAs and are not allowed to access the Distributed System (DS), thus forming a self-contained network.

[0060] A STA's membership in the BSS can be dynamically changed by opening or closing the STA, entering or leaving a BSS zone, etc. To become a member of the BSS, an STA can join the BSS using a synchronization process. To access all services of the BSS infrastructure, an STA should be associated with the BSS. This association can be established dynamically and can include the use of Distributed System Services (DSS).

[0061] Direct STA-to-STA distance in a wireless LAN can be limited by PHY performance. In some cases, this distance limit may be sufficient, but in others, communication between STAs at greater distances may be required. Distributed systems (DS) can be configured to support extended coverage.

[0062] DS refers to the interconnected structure of BSSs. Specifically, such as... Figure 2As shown, a BSS can exist as an extension of a network composed of multiple BSSs. A DS is a logical concept and can be specified by the characteristics of the Distributed System Medium (DSM). In this respect, the Wireless Medium (WM) and the DSM can be logically separated. Each logical medium is used for a different purpose and by different components. These media are not limited to being the same, nor are they limited to being different. Thus, the flexibility of wireless LAN architectures (DS architectures or other network architectures) can be interpreted as multiple media being logically different. That is, wireless LAN architectures can be implemented in various ways, and the corresponding wireless LAN architectures can be independently specified by the physical characteristics of each embodiment.

[0063] DS can support mobile devices by providing seamless integration of multiple BSSs and the logical services necessary for address addressing to the destination. Additionally, DS can further include a component called a portal, which acts as a bridge for connections between the wireless LAN and other networks, such as IEEE 802.X.

[0064] An AP enables access to a DS via WM for its associated non-AP STA, and this implies an entity that also functions as a STA. Data movement between the BSS and DS can be performed through the AP. For example, Figure 2 STA2 and STA3, as shown, possess the functionality of STAs and provide the ability for 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 address used by an AP for communication on the WM is not necessarily the same as the address used by an AP for communication on the DSM. A BSS consisting of APs and one or more STAs can be referred to as an infrastructure BSS.

[0065] Data sent from one of the STAs associated with the AP to the STA address of the corresponding AP can always be received on an uncontrolled port and can be processed by an IEEE 802.1X port access entity. Alternatively, when the controlled port is authenticated, transmitted data (or frames) can be delivered to the DS.

[0066] In addition to the DS structure described above, an Extended Service Set (ESS) can be configured to provide broad coverage.

[0067] An ESS (Service Set Identity) refers to a network of arbitrary size and complexity consisting of DS (Service Controller) and BSS (Service Set Service). An ESS can correspond to a set of BSSs connected to a DS. However, an ESS does not include the DS. An ESS network is characterized by being treated as an IBSS (Independent Service Set Service) within the Logical Link Control (LLC) layer. STAs included in an ESS can communicate with each other, and a mobile STA can move from one BSS to another BSS (within the same ESS), which is transparent to the LLC. APs included in an ESS can have the same Service Set Identity (SSID). The SSID is distinct from the BSSID, which is the identifier of the BSS.

[0068] Wireless LAN systems do not assume anything about the relative physical location of BSSs, and all of the following forms are possible. BSSs can partially overlap, which is a common form used to provide continuous coverage. Additionally, BSSs may not have physical connections, and logically, there is no limit to the distance between BSSs. Furthermore, BSSs may be physically located in the same location, which can be used to provide redundancy. Additionally, one (or more) IBSS or ESS networks can physically exist in the same space as one (or more) ESS networks. This can be analogous to the form corresponding to 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.

[0069] Figure 3 This is a diagram used to explain the link setup process to which this disclosure can be applied.

[0070] For a STA to establish a link to the network and send / receive data, the network must first be discovered, authentication performed, and association established. A security authentication process is also required. This link establishment process can also be called the session initiation process or session setup process. Furthermore, the discovery, authentication, association, and security settings within the link establishment process can be collectively referred to as the association process.

[0071] In step S310, the STA can perform a network discovery operation. The network discovery operation may include a scanning operation by the STA. That is, in order for the STA to access the network, it needs to find networks it can participate in. Before participating in a wireless network, the STA should identify compatible networks, and the process of identifying networks present in a specific area is called scanning.

[0072] Scanning schemes include active scanning and passive scanning. Figure 3An exemplary illustration depicts a network discovery operation including an active scanning process. In an active scan, the STA performing the scan sends probe request frames while moving channels to discover which APs are present in its vicinity and awaits a response. A responder sends a probe response frame to the STA that sent the probe request frame as a response to the probe request frame. Here, the responder could be the STA that last sent a beacon frame in the BSS of the scanned channel. In the BSS, the AP becomes the responder because it sends a beacon frame, and in the IBSS, STAs in the IBSS take turns sending beacon frames, so the responder is not constant. For example, an 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 a scan in the same manner (i.e., sending / receiving probe requests / responses on channel 2).

[0073] Although Figure 3 Although not shown, scanning operations can be performed passively. In passive scanning, the STA performing the scan waits for beacon frames while moving through channels. Beacon frames are one of the management frames defined in IEEE 802.11 and are sent periodically to notify of the existence of a wireless network and allow the STA performing the scan to find and participate in the network. In a BSS, the AP uses beacon frames to send them periodically, and in an IBSS, STAs within the IBSS take turns sending beacon frames. When a STA performing the scan receives a beacon frame, it stores the BSS information included in the beacon frame and records the beacon frame information for each channel while moving to another channel. The STA receiving the beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform the scan in the next channel in the same manner. Comparing active and passive scanning, active scanning has the advantages of lower latency and lower power consumption.

[0074] After the STA discovers the network, an authentication process can be performed in step S320. To clearly distinguish this authentication process from the security setup operation in step S340, which will be described later, this authentication process can be referred to as the first authentication process.

[0075] The authentication process includes the STA sending an authentication request frame to the AP, and in response, the AP sending an authentication response frame to the STA. The authentication frame used for the authentication request / response corresponds to the management frame.

[0076] The authentication frame includes the authentication algorithm number, authentication transaction sequence number, status code, challenge text, robust security network (RSN), and finite cycle group, etc. This corresponds to some examples of information that can be included in the authentication request / response frame, and may be replaced with other information or may include further additional information.

[0077] A STA can send an authentication request frame to an AP. The AP can determine whether to allow the corresponding STA to authenticate based on the information included in the received authentication request frame. The AP can then provide the result of the authentication process to the STA via an authentication response frame.

[0078] After successful STA authentication, the association process can be performed in step S330. The association process includes the STA sending an association request frame to the AP, and in response, the AP sending an association response frame to the STA.

[0079] For example, an association request frame may include information related to various capabilities, beacon listening intervals, service set identifiers (SSIDs), supported rates, supported channels, RSNs, mobile domains, supported operation classes, service indication map broadcast requests (TIM broadcast requests), and interoperability capabilities. Similarly, an association response frame may include information related to various capabilities, status codes, association IDs (AIDs), supported rates, enhanced distributed channel access (EDCA) parameter sets, received channel power indicators (RCPIs), received signal-to-noise ratio indicators (RSNIs), mobile domains, timeout intervals (e.g., association recovery time), overlapping BSS scan parameters, TIM broadcast responses, and quality of service (QoS) maps. These correspond to examples of information that can be included in association request / response frames and may be replaced with other information or further supplementary information.

[0080] After the STA successfully associates with the network, a security setup process can be performed in step S340. The security setup process in step S340 can be referred to as the authentication process via a Robust Secure Network Association (RSNA) request / response, and the authentication process in step S320 is referred to as the first authentication process. The security setup process in step S340 can also be simply referred to as the authentication process.

[0081] The security setup process in step S340 may include, for example, a process of establishing a private key via a four-way handshake using Extensible Authentication Protocol (EAPOL) frames over a LAN. Alternatively, the security setup process may be performed according to a security scheme not defined in the IEEE 802.11 standard.

[0082] Figure 4 This is a diagram used to explain the retreat process to which this disclosure can be applied.

[0083] In wireless LAN systems, the basic access mechanism for Media Access Control (MAC) is Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA). Also known as the Distributed Coordination Function (DCF) of IEEE 802.11 MAC, CSMA / CA essentially employs a "listen-before-speak" access mechanism. Under this type of access mechanism, the AP and / or STA can perform a sensed free channel assessment (CCA) of the wireless channel or medium within a predetermined time interval (e.g., the DCF inter-frame interval (DIFS)) before initiating transmission. As a result of the sensing, if the medium is determined to be idle, frame transmission begins through the corresponding medium. Conversely, if the medium is detected to be occupied or busy, the corresponding AP and / or STA does not initiate its own transmission and can set a delay period for medium intervention (e.g., a random backoff period) and attempt frame transmission after waiting. By applying a random backoff period, collisions can be minimized because several STAs are expected to attempt frame transmission after waiting for different time periods.

[0084] In addition, the IEEE 802.11 MAC protocol provides Hybrid Coordination Function (HCF). HCF is based on DCF and Point Coordination Function (PCF). PCF is a polling-based synchronous access method, referring to a method in which all receiving APs and / or STAs periodically poll to receive data frames. Furthermore, HCF includes Enhanced Distributed Channel Access (EDCA) and HCF-Controlled Channel Access (HCCA). EDCA is a contention-based access method used by providers to deliver data frames to multiple users, while HCCA uses a polling mechanism to employ a non-contention-based channel access method. Additionally, HCF includes a media access mechanism for improving the QoS (Quality of Service) of wireless LANs and can transmit QoS data in both contention-based (CP) and contention-free (CFP) periods.

[0085] refer to Figure 4 This section describes the operation based on a random backoff period. When a occupied / busy medium becomes idle, several STAs can attempt to transmit data (or frames). As a method to minimize collisions, each STA can individually select a random backoff count and attempt transmission after waiting for the corresponding time slot. 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 assigned an initial value of CWmin, but can take a value twice as large if a transmission failure occurs (e.g., when an ACK for a transmitted frame is not received). When the CW parameter value reaches CWmax, data transmission can be attempted while maintaining the CWmax value until successful data transmission, and the CWmin value is reset when data transmission is successful. The values ​​of CW, CWmin, and CWmax are preferably set to 2.n -1 (n = 0, 1, 2, ...).

[0086] When the random backoff process begins, the STA continuously monitors the medium while counting down the backoff time slot based on the determined backoff count value. When medium occupancy is detected, it stops counting down and waits, and resumes the remaining countdown when the medium becomes free.

[0087] exist Figure 4 In the example, when the packet to be sent arrives at STA3's MAC, STA3 can send the frame immediately after confirming that the medium is free for as long as DIFS. The remaining STAs monitor and wait for the medium to be occupied / busy. Meanwhile, data to be sent may also occur in each of STA1, STA2, and STA5, and when the medium is detected as free, each STA waits for as long as DIFS, and can then count down the backoff slots according to a random backoff count value selected by each STA. Assume that STA2 chooses the minimum backoff count value, and STA1 chooses the maximum backoff count value. That is, the case where STA5's remaining backoff time is less than STA1's remaining backoff time when STA2 completes its backoff count and begins frame transmission is illustrated. STA1 and STA5 temporarily stop the countdown and wait, while STA2 occupies the medium. When STA2 finishes occupying the medium and it becomes free again, STA1 and STA5 wait for DIFS and resume the stopped backoff count. That is, after counting down the remaining backoff slots for the remaining backoff time, frame transmission can begin. Because STA5's remaining backoff time is less than STA1's, STA5 begins frame transmission. While STA2 is occupying the medium, data to be transmitted may also appear in STA4. From STA4's perspective, when the medium becomes idle, STA4 can wait for DIFS, and then execute a countdown based on a random backoff count value selected by STA4 and begin transmitting frames. Figure 4 The example illustrates a scenario where the remaining backoff time of STA5 coincides exactly with the random backoff count value of STA4. In this case, a collision can occur between STA4 and STA5. When a collision occurs, neither STA4 nor STA5 receives an ACK, thus data transmission fails. In this situation, STA4 and STA5 can double their CW value, choose a random backoff count value, and begin a countdown. STA1 waits while the medium is occupied due to the transmissions of STA4 and STA5, waits for DIFS when the medium becomes idle, and then begins frame transmission after the remaining backoff time has elapsed.

[0088] like Figure 4As shown in the example, data frames are frames used to transmit data forwarded to higher layers and can be sent after a backoff performed after the DIFS (Distributed Access Frame) begins to elapse when the medium becomes idle. Management frames, on the other hand, are frames used to exchange management information that is not forwarded to higher layers and are sent after a backoff performed after an IFS (Initial Point Coordination Function) such as a DIFS or a Point Coordination Function IFS (PIFS). Subtypes of management frames include beacons, association requests / responses, reassociation requests / responses, probe requests / responses, authentication requests / responses, etc. Control frames are frames used to control access to the medium. Subtypes of control frames include request to send (RTS), clear send (CTS), acknowledge (ACK), power-saving polling (PS-Poll), block ACK (BlockAck), block ACK request (BlockACKReq), empty data packet announcement (NDP announcement), and triggers, etc. If a control frame is not a response frame to a previous frame, it is sent after a backoff performed after the DIFS elapses; if it is a response frame to a previous frame, it is sent without a backoff performed after the short IFS (SIFS) elapses. The type and subtype of a frame can be identified by the type field and subtype field in the Frame Control (FC) field.

[0089] The Quality of Service (QoS) ST can perform a backoff following the Arbitration IFS (AIFS) of the Access Class (AC) to which the frame belongs, i.e., AIFS[i] (where i is a value determined by the AC), and then the frame can be sent. Here, frames that can use AIFS[i] can be data frames, management frames, or control frames other than response frames.

[0090] Figure 5 This is a diagram used to explain the CSMA / CA-based frame transmission operation to which this disclosure can be applied.

[0091] As mentioned above, the CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing, which is directly sensed by the STA. Virtual carrier sensing is designed to compensate for problems that may arise in media access, such as hidden node issues. For virtual carrier sensing, the STA's MAC can use a Network Allocation Vector (NAV). The NAV is a value that indicates to other STAs the remaining time until the media becomes available for use by the currently used or authorized STA. Therefore, a value set to NAV corresponds to a period of time during which the media is scheduled for use by the STA sending the frame, and the STA receiving the NAV value is prohibited from accessing the media during the corresponding period. For example, the NAV can be configured based on the value of the "Duration" field in the MAC header of the frame.

[0092] exist Figure 5In the example, assume that STA1 intends to send data to STA2, and STA3 is in a position that allows it to eavesdrop on some or all of the frames being sent and received between STA1 and STA2.

[0093] To reduce the likelihood of transmission conflicts between multiple STAs in CSMA / CA-based frame transmission operations, a mechanism using RTS / CTS frames can be applied. Figure 5 In the example, while 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 can correspond to a hidden node of STA3. Alternatively, in Figure 5 In the example, it can be determined that the carrier sensing result medium of STA3 is idle while the transmission of STA2 is being performed. That is, STA2 can correspond to a hidden node of 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 STAs outside the carrier sensing range for transmissions from STA1 or STA3, can not attempt to occupy the channel during data transmission and reception between STA1 and STA2.

[0094] Specifically, STA1 can determine whether a channel is in use through carrier sensing. Regarding physical carrier sensing, STA1 can determine the channel occupancy status based on the energy level or signal correlation detected in the channel. Furthermore, regarding virtual carrier sensing, STA1 can use a network allocation vector (NAV) timer to determine the channel occupancy status.

[0095] When the channel is idle during DIFS, STA1 can send an RTS frame to STA2 after performing backoff. When STA2 receives the RTS frame, STA2 can send a CTS frame to STA1 after SIFS as a response to the RTS frame.

[0096] If STA3 cannot eavesdrop on CTS frames from STA2 but can eavesdrop on RTS frames from STA1, STA3 can use the duration information included in the RTS frame to set the NAV timer for subsequent consecutive frame transmission cycles (e.g., SIFS+CTS frame+SIFS+data frame+SIFS+ACK frame). Alternatively, if STA3 can eavesdrop on CTS frames from STA2, even if STA3 cannot eavesdrop on RTS frames from STA1, STA3 can use the duration information included in the CTS frame to set the NAV timer for subsequent consecutive frame transmission cycles (e.g., SIFS+data frame+SIFS+ACK frame). That is, if STA3 can eavesdrop on one or more RTS or CTS frames from STA1 or STA2, STA3 can set the NAV accordingly. When STA3 receives a new frame before the NAV timer expires, STA3 can update the NAV timer using the duration information included in the new frame. STA3 does not attempt channel access before the NAV timer expires.

[0097] When STA1 receives a CTS frame from STA2, STA1 can send a data frame to STA2 after the SIFS period starting from the time when the CTS frame reception is completed. When STA2 successfully receives the data frame, STA2 can send an ACK frame to STA1 as a response to the data frame after the SIFS period. When the NAV timer expires, STA3 can determine whether the channel is being used through carrier sensing. When 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) for random backoff has elapsed.

[0098] Figure 6 This is a diagram used to explain an example of the frame structure that can be used in a WLAN system to which this disclosure can be applied.

[0099] Using instructions or primitives (meaning a set of instructions or parameters) from the MAC layer, the PHY layer can prepare a MAC PDU (MPDU) to be sent. For example, when it receives a command from the MAC layer requesting the PHY layer to begin transmission, the PHY layer switches to transport mode and configures the information (e.g., data) provided from the MAC layer in the form of a frame and sends it. Additionally, when the PHY layer detects a valid preamble to a received frame, it monitors the preamble header and sends a command to the MAC layer notifying the PHY layer of the start of reception.

[0100] In this way, information transmission / reception in a wireless LAN system is performed in the form of frames, and for this purpose, the PHY layer Protocol Data Unit (PPDU) frame format is defined.

[0101] A basic PPDU frame can include a Short Training Field (STF), a Long Training Field (LTF), a Signal (SIG) field, and a Data field. The most basic PPDU format (e.g., Figure 7 The non-HT (high throughput) fields shown can consist solely of legacy STF (L-STF), legacy LTF (L-LTF), legacy SIG (L-SIG) fields, and a data field. Additionally, depending on the PPDU format type (e.g., HT mixed format PPDU, HT-greenfield format PPDU, VHT (very high throughput) PPDU, etc.), additional (or different types of) RL-SIG, U-SIG, non-legacy SIG fields, non-legacy STF, non-legacy LTF (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)) can be included between the L-SIG field and the data field.

[0102] STF is a signal used for signal detection, automatic gain control (AGC), diversity selection, precise time synchronization, etc., while LTF is a signal used for channel estimation and frequency error estimation. STF and LTF can be referred to as signals used for synchronization and channel estimation in the OFDM physical layer.

[0103] The SIG field can include various information related to PPDU transmission and reception. For example, the L-SIG field consists of 24 bits and can 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 can include information about the modulation and coding rate of the data. For example, the 12-bit length field can include information about the length or duration of the PPDU. For example, the value of the 12-bit length field can be determined based on the type of PPDU. For example, for non-HT, HT, VHT, or EHT PPDUs, the value of the length field can be determined to be a multiple of 3. For example, for HE PPDUs, the value of the length field can be determined to be a multiple of 3 + 1 or 3 + 2.

[0104] The data field may include the SERVICE field, Physical Layer Service Data Unit (PSDU), and PPDU tail bits, and may also include padding bits if necessary. Some bits of the SERVICE field can be used for synchronization of the descrambler at the receiver. 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 bits can be used to return the encoder to a 0 state. Padding bits can be used to adjust the length of the data field in predetermined units.

[0105] MAC PDUs are 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). MAC frames can be composed of MAC PDUs and are transmitted / received via the PSDU in the data portion of the PPDU frame format.

[0106] The MAC header includes a frame control field, a duration / ID field, and an address field. The frame control field can include control information required for frame transmission / reception. The duration / ID field can be set to the time for transmitting the corresponding frame. For detailed information on the sequence control, QoS control, and HT control subfields of the MAC header, please refer to the IEEE 802.11 standard document.

[0107] The NDP (Narrow Data PPDU) format refers to a PPDU format that does not include the data field. In other words, NDP refers to a frame format that includes the PPDU preamble (i.e., L-STF, L-LTF, L-SIG fields and additional non-legacy SIG, non-legacy STF, and non-legacy LTF (if present)) but does not include the remaining portion (i.e., the data field) in the general PPDU frame format.

[0108] Figure 7 This is a diagram illustrating an example of a PPDU as defined in the IEEE 802.11 standard that can be applied to this disclosure.

[0109] Various types of PPDUs are used in standards such as IEEE 802.11a / g / n / ac / ax. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and a data field. The basic PPDU format can also be referred to as a non-HT PPDU format (e.g., ...). Figure 7 (as shown in (a)).

[0110] In addition to the basic PPDU format, the HT PPDU format (IEEE 802.11n) also includes the HT-SIG, HT-STF and HT-LFT fields. Figure 7 The HT PPDU format shown in (b) can be called the HT-mixed format. Alternatively, an HT-greenfield format PPDU can be defined, which corresponds to a format consisting of 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).

[0111] Examples of VHT PPDU format (IEEE 802.11ac) include, in addition to the basic PPDU format, VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields (such as...). Figure 7 (as shown in (c)).

[0112] Examples of HE PPDU format (IEEE 802.11ax) include, in addition to the basic PPDU format, repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), and packet extension (PE) fields (such as...). Figure 7 (as shown in (d)). Based on the detailed example of the HE PPDU format, some fields may be excluded or their lengths may vary. For example, the HE-SIG-B field is included in the HE PPDU format for multi-user (MU) applications, but not in the HE PPDU format for single-user (SU) applications. Additionally, the HE trigger (TB) based PPDU format does not include HE-SIG-B, and the length of the HE-STF field may vary to 8µs. The extended range (HE ER) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may vary to 16µs. For example, RL-SIG can be configured to be the same as L-SIG. The receiving STA can determine whether the received PPDU is an HE PPDU or an EHT PPDU based on the presence of RL-SIG, which will be described later.

[0113] EHT PPDU format can include Figure 7 (e) EHT MU (Multi-user) and Figure 7 (f) EHT TB (trigger-based) PPDU. The EHT PPDU format is similar to the HE PPDU format in that it includes RL-SIG, followed by L-SIG, but may include U (generic)-SIG, EHT-SIG, EHT-STF and EHT-LTF following RL-SIG.

[0114] Figure 7 In (e), the EHT MU PPDU 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 and MU transmissions. For example, the EHT MU PPDU can correspond to a PPDU used for one or more receiving STAs.

[0115] Compared to EHT MU PPDU, Figure 7 In (f), the EHT-SIG is omitted from the EHT TB PPDU. A STA that receives a trigger (e.g., a trigger frame or trigger response schedule (TRS)) for UL MU transmission can perform UL transmission based on the EHT TB PPDU format.

[0116] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (General Signal), and EHT-SIG fields can be encoded and modulated so that even legacy STAs can attempt demodulation and decoding, and can be mapped based on a determined subcarrier frequency interval (e.g., 312.5 kHz). These can be referred to as pre-EHT modulated fields. Next, the EHT-STF, EHT-LTF, Data, and PE fields can be encoded and modulated for demodulation and decoding by an STA that has successfully decoded a non-legacy SIG (e.g., U-SIG and / or EHT-SIG) and obtained the information contained in the fields, and can be mapped based on a determined subcarrier frequency interval (e.g., 78.125 kHz). These can be referred to as EHT modulated fields.

[0117] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields can be referred to as pre-HE modulation fields, and the HE-STF, HE-LTF, Data, and PE fields can be referred to as HE modulation fields. Additionally, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields can be referred to as free VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and Data fields can be referred to as VHT modulation fields.

[0118] Figure 7 The U-SIG included in the EHT PPDU format can be configured based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol used for the U-SIG (e.g., an OFDM symbol) can have a duration of 4 µs, and the U-SIG can have a total duration of 8 µs. Each symbol of the U-SIG can be used to transmit 26 bits of information. For example, each symbol of the U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0119] U-SIGs can be constructed in 20MHz units. For example, if an 80MHz PPDU is constructed, the U-SIGs may be repeated. That is, an 80MHz PPDU can include the same four U-SIGs. PPDUs with bandwidths exceeding 80MHz can include different U-SIGs.

[0120] For example, A uncoded bits can be sent via U-SIG. The first symbol of U-SIG (e.g., U-SIG-1 symbol) can send the first X bits of the total A bits of information, and the second symbol of U-SIG (e.g., U-SIG-2 symbol) can send the remaining Y bits of the total A bits of information. The A bits of information (e.g., 52 uncoded bits) can include a CRC field (e.g., a 4-bit field) and a tail field (e.g., a 6-bit field). For example, the tail field can be used to terminate the grid of the convolutional decoder and can be set to 0.

[0121] The bit information sent by U-SIG can be divided into version-independent bits and version-dependent bits. For example, U-SIG can be included in... Figure 7 In the new PPDU format (e.g., UHR PPDU format) not shown in the figure, and in the format of the U-SIG field included in the EHT PPDU format and the format of the U-SIG field included in the UHR PPDU format, the version-independent bits may be the same, and some or all of the version-related bits may be different.

[0122] For example, the size of the version-independent bits in U-SIG can be fixed or variable. Version-independent bits can be assigned only to the U-SIG-1 symbol, or to both the U-SIG-1 and U-SIG-2 symbols. Version-independent bits and version-dependent bits can be referred to by various names, such as first control bits and second control bits.

[0123] For example, the version-independent bits of U-SIG may include a 3-bit Physical Layer Version Identifier (PHY Version Identifier), and this information can indicate the PHY version (e.g., EHT, UHR, etc.) of the transmitted / received PPDU. The version-independent bits of 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 U-SIG may include information about the length of the Transmission Opportunity (TXOP) and information about the BSS color ID.

[0124] For example, the version-related bits of U-SIG may include information that directly or indirectly indicates the type of PPDU (e.g., SUPPDU, MU PPDU, TB PPDU, etc.).

[0125] The information necessary for PPDU transmission and reception can be included in the U-SIG. For example, the U-SIG may further include information about the bandwidth, information about the MCS technique applied to the non-legacy SIG (e.g., EHT-SIG or UHR-SIG), information indicating whether a DCM (dual-carrier modulation) technique (e.g., a technique that achieves a frequency diversity-like effect by repeating 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 may also include information about whether the non-legacy SIG is generated across the entire band, etc.

[0126] Some information necessary for PPDU transmission and reception can be included in the U-SIG and / or non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.). For example, information about the type of non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information about the length of the non-legacy LTF and the CP (cyclic prefix) length, information about the GI (guard interval) applicable to the non-legacy LTF, information about the preamble perforation applicable to the PPDU, information about RU (resource unit) allocation, etc., can be included only in the U-SIG, only in the non-legacy SIG, or indicated by a combination of information included in the U-SIG and information included in the non-legacy SIG.

[0127] A preamble can refer to the transmission of a PPDU in which no signal is present in one or more frequency units within the bandwidth of the PPDU. For example, the size of the frequency unit (or the resolution of the preamble) can be defined as 20MHz, 40MHz, etc. For example, a preamble can be applied to a PPDU of a predetermined size or larger bandwidth.

[0128] exist Figure 7 In the examples, non-legacy SIGs such as HE-SIG-B and EHT-SIG can include control information for receiving STAs. Non-legacy SIGs can be transmitted on at least one symbol, and a symbol can have a length of 4 µs. Information regarding the number of symbols used for EHT-SIGs can be included in previous SIGs (e.g., HE-SIG-A, U-SIG, etc.).

[0129] Non-legacy SIGs such as HE-SIG-B and EHT-SIG can include public fields and user-specific fields. Public fields and user-specific fields can be encoded separately.

[0130] In some cases, the common field can be omitted. For example, in compressed mode using non-OFDMA (Orthogonal Frequency Multiple Access), the common field can be omitted, and multiple STAs can receive PPDUs (e.g., the data field of the PPDU) through the same frequency band. In uncompressed mode using OFDMA, multiple users can receive PPDUs (e.g., the data field of the PPDU) through different frequency bands.

[0131] The number of user-specific fields can be determined based on the number of users. A user block field can include up to two user fields. Each user field can be associated with a MU-MIMO allocation or with a non-MU-MIMO allocation.

[0132] The common fields may include CRC bits and tail bits, where the length of the CRC bits can be determined to be 4 bits, and the length of the tail bits can be determined to be 6 bits and set to 000000. The common fields may include RU allocation information. RU allocation information may include information about the locations of RUs assigned to multiple users (i.e., multiple receiving STAs).

[0133] An RU can include multiple subcarriers (or tones). RUs can be used when transmitting signals to multiple STAs based on OFDMA technology. Additionally, RUs can be defined even when transmitting signals to a single STA. Resources can be allocated in units of RUs for non-legacy STFs, non-legacy LTFs, and data fields.

[0134] The appropriate RU size can be defined based on the PPDU bandwidth. For the applied PPDU format (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.), the RUs can be defined the same or different. For example, in the case of an 80MHz PPDU, the RU placement for HEPPDU and EHT PPDU may differ. The applicable RU size, number and location, DC (direct current) subcarrier location and number, empty subcarrier location and number, guard subcarrier location and number, etc., for each PPDU bandwidth can be referred to as the tone scheme. For example, a tone scheme for high bandwidth can be defined as multiple iterations of a low bandwidth tone scheme.

[0135] 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, etc. An MRU (multiple RUs) is distinguished from multiple individual RUs and corresponds to a group of subcarriers composed 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. Furthermore, the multiple RUs constituting an MRU can be continuous or non-contiguous in the frequency domain.

[0136] The specific size of an RU can be reduced or increased. Therefore, the specific size of each RU (i.e., the number of corresponding tones) in this disclosure is not limiting and is illustrative. In addition, in this disclosure, the number of RUs can vary depending on the RU size within a predetermined bandwidth (e.g., 20, 40, 80, 160, 320 MHz, ...).

[0137] Figure 7 The names of each field in the PPDU format are exemplary, and the scope of this disclosure is not limited to the names. Furthermore, the examples in this disclosure can be applied to... Figure 7 The PPDU format illustrated in the figure, and its application in... Figure 7 The PPDU format excludes some fields and / or adds some fields to the new PPDU format.

[0138] Figure 8 This is a diagram illustrating an example format of a trigger frame to which the contents of this disclosure can be applied.

[0139] A trigger frame can allocate resources for the transmission of one or more TB PPDUs and request the transmission of TB PPDUs. The trigger frame may also include other information required by the STA, which sends a TB PPDU in response. The trigger frame may include public information and user information list fields in the frame body.

[0140] The public information field is information typically used for the transmission of one or more TB PPDUs requested by a trigger frame, such as trigger type, UL length, presence or absence of subsequent trigger frames (e.g., more TF), CS (channel sensing) request, ULBW (bandwidth), HE / EHT P160, special user information field flags, etc.

[0141] The 4-bit trigger type subfield can have values ​​from 0 to 15. Among them, the values ​​0, 1, 2, 3, 4, 5, 6, and 7 of the trigger type subfield are defined to correspond to Basic, BFRP (Beamforming Report Polling), MU-BAR (Multi-User Block Acknowledgment Request), MU-RTS (Multi-User Request Transmission), BSRP (Buffer Status Report Polling), GCR (Multicast with Retry), MU-BAR, BQRP (Bandwidth Query Report Polling), and NFRP (NDP Feedback Report Polling), respectively, and values ​​8 to 15 are defined as reserved.

[0142] In public information, the trigger-related public information subfields may include information that can be optionally included based on the trigger type.

[0143] Special user information fields can be included in the trigger frame. These fields do not include user-specific information, but do include extended public information not provided in the public information fields.

[0144] The user information list includes zero or more user information fields. Figure 8 An example of the EHT variant user information field format is shown.

[0145] The AID12 subfield essentially indicates that it is a user information field for a STA with a corresponding AID. Furthermore, if the AID12 field has a specific predetermined value, it can be used for other purposes, such as assigning a Random Access (RA)-RU or being configured as a special user information field. A special user information field is a user information field that does not include user-specific information but includes extended public information not provided in the public information field. For example, a special user information field can be identified by the AID12 value of 2007, and the special user information field flag subfield within the public information field can indicate whether a special user information field is included.

[0146] The RU allocation subfield can indicate the size and location of the RU / MRU. Therefore, the RU allocation subfield can be interpreted together with the PS160 (primary / secondary 160 MHz) subfield of the user information field, the UL BW subfield of the public information field, etc.

[0147] HT control fields

[0148] The following will describe the reference in more detail. Figure 6 The HT control field is included in the MAC header described.

[0149] The HT control field can exist in the control wrapper frame, and can also exist in QoS data, QoS null values, and management frames determined by the +HTC subfield of the frame control field.

[0150] STAs that support receiving HT control fields of control wrapper frames can process them as if they were frames of a subtype that have already received wrapper frames. HE STAs may not send control wrapper frames to other HE STAs.

[0151] The format of the HT control field is shown in Table 1 below.

[0152] Table 1

[0153] As shown in Table 1, the HT control field can include three variants (e.g., HT variant, VHT variant, and HE variant). The variant formats can be distinguished by the values ​​of the first bit (B0) and the second bit (B1) of the HT control field.

[0154] The HT variant HT control field may include HT control intermediate subfields, while the VHT variant HT control field may include VHT control intermediate subframes. The VHT control intermediate subfields may include MRQ subfields, MSI / STBC subfields, MFSI / GID-L subfields, MFP subfields, GID-H subfields, encoding type subfields, FB Tx type subfields, and unrequested MFB subfields.

[0155] The HE variant HT control field may include an aggregated control subfield. The A-control subfield may include a variable-length control list subfield and zero or more padding subfields. The control list may include one or more control subfields. The control subfield may include a 4-bit control ID subfield and a variable-length control information subfield.

[0156] The Control ID subfield indicates the type of information transmitted in the Control Message subfield. For each value in the Control ID subfield that is not reserved, the length of the Control Message subfield can be fixed. The values ​​of the Control ID subfield and the associated lengths of the Control Message subfields can be defined as shown in Table 2 below.

[0157] Table 2

[0158] Information corresponding to control ID values ​​0 through 6 can be defined in the A-control subfield of the HE variant HT control field. Information corresponding to control ID values ​​7 through 9 can be newly defined information for EHT STA. Furthermore, information corresponding to control ID value 10 (i.e., AAR) can correspond to control ID value 9. Additionally, if a padding subfield exists in the A-control subfield of the HE variant HT control field, the padding subfield follows the last control subfield and can be set to a sequence of zeros, making the length of the A-control subfield carried in the HT control field 30 bits.

[0159] Information transmission process used for low-latency service preemption

[0160] In a basic wireless LAN system, a STA (e.g., a non-AP STA and / or an AP) can perform channel access operations to transmit frames containing traffic. For example, an AP and / or a non-AP STA can obtain a transmission opportunity (TXOP) via Enhanced Distributed Channel Access (EDCA) and transmit frames within the obtained TXOP. As another example, a non-AP STA can transmit frames in response to a trigger frame received from an AP.

[0161] In other words, when a specific service is entered / generated in the transmission queue of an STA, the STA must perform channel access to send the specific service, thereby occupying the channel and / or obtaining a TXOP. Here, it is assumed that a service requiring significantly low latency (i.e., a low-latency service) is entered / generated in the STA's transmission queue. In order for the STA to send low-latency services, competition for channel access with other STAs is unavoidable, and if other STAs have already obtained a TXOP, there is a problem that the fast transmission of low-latency services is not guaranteed.

[0162] In describing this disclosure, services requiring low latency (e.g., services that must be successfully transmitted within X ms) are referred to as LLT (Low Latency Services).

[0163] Figure 9 This is a diagram used to explain issues related to LLT transmission in DL (downlink) TXOP.

[0164] Specifically, such as Figure 9 As illustrated in the diagram, when the AP (i.e., the TXOP holder) acquires a TXOP via channel access (DL) and then performs a frame exchange with STA 1 (i.e., the TXOP responder), the LLT to be sent from the AP to STA 2 can arrive at time T_1. STA 2 can set NAV due to the AP's TXOP, or determine the channel state as busy due to the frame exchange between the AP and STA 1.

[0165] Therefore, STA 2 can send LLT after performing a backoff procedure again after the AP's TXOP. In this case, the length of the AP's TXOP may be long, and depending on the contention outcome when STA 2 performs backoff after the AP's TXOP, there is a possibility that other STAs may obtain the TXOP. Therefore, STA 2's LLT transmission may be significantly delayed, and there is a possibility that the LLT requirement may not be met.

[0166] Figure 10 This is a diagram used to explain issues related to LLT transmission in UL (uplink) TXOP.

[0167] Specifically, such as Figure 10 As illustrated, when STA 1 (i.e., the TXOP holder) acquires its TXOP via channel access (UL) and then performs a frame exchange with the AP (i.e., the TXOP responder), the LLT to be sent to STA 2 can arrive at the AP at time T_1. Because the AP is performing a frame exchange within STA 1's TXOP, it cannot send the LLT to STA 2. Therefore, the AP can perform a backoff procedure again after STA 1's TXOP and then send the LLT to STA 2.

[0168] Here, the length of STA 1's TXOP may be relatively long, and depending on the contention outcome when the AP performs backoff after STA 1's TXOP, there is a possibility that another STA may acquire the TXOP. Therefore, the AP's LLT transmission may be significantly delayed, and there is a possibility that LLT requirements may not be met.

[0169] For reference Figure 9 and Figure 10 In the described example, when a LLT (i.e., an LLT with transmission-related requirements) that a STA needs to transmit quickly arrives, there is a possibility that the STA may be unable to meet the requirement and transmit the LLT due to channel access delays caused by the TXOP length already acquired by another STA or competition with other STAs. This disclosure describes a method for solving the above problem.

[0170] The names of the processes and / or parameters described in this disclosure may be changed, and STAs may include non-AP STAs or AP STAs. Additionally, in the description of this disclosure, RU (Resource Unit) may refer to either an RU or an M (Multiple) RU.

[0171] Figure 11 This is a flowchart illustrating the operation of a first STA according to an embodiment of the present disclosure. Figure 11 and Figure 12In this configuration, the first STA and the second STA can each be implemented as a non-AP STA or an AP, and the AP can be replaced by another non-AP STA. Furthermore, the AP can be a TXOP holder, and the first STA can be a TXOP responder.

[0172] The first STA can receive the first PPDU (S1110) including the polling frame from the AP.

[0173] In one example of this disclosure, a polling frame (or LLT polling frame) can trigger the transmission of information about a first LLT of a first STA. In one example, the polling frame may include information about the maximum bandwidth of the channel used for LLT transmission and / or information indicating whether the primary channel is included on the first channel (i.e., the channel on which the first frame associated with the first LLT will be transmitted). Furthermore, the polling frame may include information about whether the primary channel is included on the channel on which another STA's LLT (e.g., a second LLT of a second STA) is to be transmitted.

[0174] Alternatively, the first PPDU may include data frames (e.g., QoS data frames). Polling frames on the first PPDU can be sent to at least one STA, including the first STA, via a broadcast RU. Furthermore, data frames on the first PPDU can be sent via an RU assigned to the first STA.

[0175] The first STA can send a first frame associated with the first LLT to the AP via a first channel including the main channel based on the polling frame (S1120). That is, the first frame associated with the first LLT can be a response frame to the polling frame.

[0176] Here, the first frame associated with the first LLT can be referred to as the first LLT indication, but is not limited to this. Furthermore, the second PPDU including the first frame can include a non-HT (high throughput) PPDU or a non-HT duplicate PPDU.

[0177] For example, the first STA can identify the first channel by performing an idle channel assessment (CCA) on the transmission of the first frame. Furthermore, the bandwidth of the first channel can be less than or equal to the maximum bandwidth indicated by the polling frame.

[0178] The first frame associated with the first LLT may include information about the first LLT. For example, the information about the first LLT may include at least one of the following: information about the presence or absence of the first LLT, identification information of the first LLT, information about the time point at which the first LLT transmission will be completed, and information about the quantity of the first LLT.

[0179] For example, based on a first PPDU that includes a data frame (e.g., a QoS data frame sent to a first STA), the first STA may send at least one of a first frame and an ACK (acknowledgment) frame for the data frame to the AP.

[0180] As an example of this disclosure, the first STA can receive a second trigger frame (e.g., an NFRP trigger frame) from the AP to determine whether the first frame has been sent. Therefore, the first STA can send information to the AP indicating that the first frame has been sent based on the second trigger frame (e.g., an NDP Feedback Report (NFR)).

[0181] Simultaneously, the second STA can send a second frame related to the second LLT to the AP via the second channel, and the second frame can contain information about the second LLT. Furthermore, the polling frame can contain information indicating whether the primary channel is included on the second channel.

[0182] The first STA can send the first LLT to the AP within the AP's transmission opportunity (TXOP) (S1130). For example, the first STA can send the first LLT to the AP based on the first trigger frame received from the AP.

[0183] Figure 11 The methods described in the examples can be derived from... Figure 1 The first device (100) executes. For example, Figure 1 One or more processors (102) of the first device (100) can receive a first PPDU including a polling frame from the AP via one or more transceivers (106). Based on the polling frame, one or more processors (102) can send a first frame associated with the first LLT to the AP via one or more transceivers (106) through a first channel including the main channel. One or more processors (102) can send the first LLT to the AP via one or more transceivers (106) within the AP's TXOP.

[0184] Furthermore, one or more memories (104) of the first device (100) may store data for execution when performed by one or more processors (102). Figure 11 The instructions for the methods described in the examples or examples described below.

[0185] Figure 12 This is a flowchart describing the operation of an AP according to an embodiment of the present disclosure.

[0186] The AP can send a first PPDU (S1210) including a polling frame to at least one STA.

[0187] Already referenced Figure 11 The configuration of the first PPDU and polling frame is described, so redundant descriptions will be omitted.

[0188] Based on the polling frame, the AP can receive the first frame associated with the first LLT from the first STA among at least one STA through the first channel including the master channel (S1220).

[0189] Alternatively, the AP may receive an ACK frame for the data frame of the first STA included in the first PPDU from the first STA. Furthermore, the AP may receive a second frame associated with the second LLT from at least one second STA.

[0190] The AP can receive the first LLT from the first STA within its TXOP (i.e., the AP's TXOP) (S1230). Furthermore, the AP can receive the second LLT from the second STA within its TXOP.

[0191] Figure 12 The methods described in the examples can be derived from... Figure 1 The second device (200) performs the operation. For example, Figure 1 One or more processors (202) of the second device (200) can send a first PPDU including a polling frame to at least one STA via one or more transceivers (206). Based on the polling frame, one or more processors (202) can receive a first frame associated with the first LLT from the first STA of the at least one STA via one or more transceivers (206) through a first channel including the master channel. One or more processors (202) can receive the first LLT from the first STA within their TXOP via one or more transceivers (206).

[0192] Furthermore, one or more memories (204) of the second device (200) may store instructions for execution when executed by one or more processors (202). Figure 12 The example or the method described in the example below.

[0193] The following describes in detail the methods used to send information to preempt low-latency services.

[0194] Example 1

[0195] Example 1 relates to a process for reporting LLT information.

[0196] Figure 13 This is a diagram illustrating a method for a STA to report LLT information to an AP according to an embodiment of the present disclosure. Figure 13In this context, "LLT TX need" means that an LLT exists / occurs that the STA must send quickly. For example, "LLTTX need" could mean that an LLT has already been entered / occurred in the STA, or that an LLT exists that must be sent quickly upon request.

[0197] here, Figure 13 The AP and STA operations in the code can be replaced with STA and AP operations, respectively. In other words, Figure 12 The operation of the AP in the middle can be replaced by the operation of another STA, and Figure 13 The STA operation can be replaced with the AP operation.

[0198] like Figure 13 As illustrated, the AP can send trigger information to one or more STAs, enabling the transmission of LLT information via the PPDU. That is, the PPDU can include a trigger frame for requesting / triggering the transmission of LLT information. Additionally, the PPDU can include frames (e.g., QoS data frames, etc.) addressed to one or more STAs.

[0199] A STA that receives a PPDU / frame that triggers LLT information can send a frame / PPDU that includes LLT information. There may be a predefined time interval (e.g., SIFS, PIFS) between the PPDU / frame that triggers LLT information and the frame that contains LLT information.

[0200] An AP that receives LLT information from one or more STAs can send a frame (e.g., a trigger frame) that enables the LLT to be transmitted to one or more STAs. One or more STAs that receive the frame can send a frame / PDU containing the LLT to the AP.

[0201] Alternatively, even if one or more STAs do not receive a PPDU / frame that triggers LLT information, they can still send LLT information to the AP. For example, in Figure 13 In this context, LLT information can be included in a frame / PDU that includes LLT information sent by a STA.

[0202] Example 1-1

[0203] Example 1-1 relates to one or more types of information included in the LLT information sent by the STA.

[0204] LLT information may include LLT presence information, LLT identification information, delay information, and / or the amount of LLT information.

[0205] For example, the LLT existence information may indicate the existence of an LLT that the STA currently needs to transmit. Additionally or alternatively, the LLT existence information may indicate whether the STA requests / expects to transmit an LLT within the TXOP of a particular STA.

[0206] The LLT existence information may be supported by a field having 1 bit (e.g., the LLT existence information field). For example, when the value of the LLT existence information field is set to 1 (or 0), this may indicate the existence of an LLT that the STA should currently transmit, or the STA requests / wants to transmit an LLT within the TXOP of a particular STA. For example, when the value of the LLT existence information field is set to 0 (or 1) or the field is reserved, this may indicate the non-existence of an LLT that the STA should currently transmit, or the STA does not request / want to transmit an LLT within the TXOP of a particular STA.

[0207] As another example, the LLT identification information may include one or more ID information about the LLT to be transmitted. That is, the LLT identification information may include information about the LLT that needs to be transmitted. As an example, the LLT identification information may utilize a traffic identifier (TID). If the LLT corresponds to at least one of TIDs 0 to 7, the field indicating the LLT identification information may be set to 3 bits, and if the LLT corresponds to at least one of TIDs 8 to 15, the field indicating the LLT identification information may be set to 4 bits.

[0208] As another example of the present disclosure, a new LLT ID may be defined to indicate the identification information of the LLT. For example, the LLTID may be defined as an ID for differentiating the LLTs for each TID. For example, the LLT may be classified as a 2-tuple <TID, LL ID). For example, if LL IDs 0 to 3 are assigned to TID 6, the LL service corresponding to TID 6 may be classified as <TID 6, LLID 0>.

[0209] Additionally or alternatively, a bitmap may be defined to accommodate the LLTs for one or more IDs. That is, the LLT identification information may consist of a bitmap representing the LLT IDs. For example, if a total of X LLT IDs are defined, the bitmap may be configured to indicate up to X LLT IDs.

[0210] For example, the delay information may include information about when the LLT should be transmitted.

[0211] For example, the delay information may include the time from the time of transmitting the LLT information or the time of completing the transmission to the time when the LLT must be successfully transmitted. In this case, the delay information may indicate the time in μs.

[0212] Alternatively, the delay information can indicate the point in time when the LLT should be successfully transmitted. For example, the delay information can be based on absolute time, timestamp (TSF) to indicate the point in time when the LLT should be successfully transmitted.

[0213] Alternatively, it may be assumed that there exists an LLT for more than one ID. That is, if there is an LLT for each of the multiple IDs, then the ID whose transmission should be completed earlier is identified, and the delay information may include the time when the transmission should be completed for that ID.

[0214] Alternatively, if an LLT exists for each of the multiple IDs, the delay information may include the time when each of the multiple IDs should complete the transmission.

[0215] For example, the amount of LLT information can include information about the amount of LLT to be sent. For example, the amount of LLT information can be configured in bytes.

[0216] Alternatively, if there are LLTs for more than one ID, the amount of LLT information can indicate the amount of LLTs for all IDs. For example, the amount of LLT information could be the sum of the amounts of LLTs for each of all IDs.

[0217] Alternatively, if there are LLTs for more than one ID, the quantity information of the LLTs can indicate the quantity of the LLTs for each ID.

[0218] Alternatively, it may be assumed that the TID is used for the LLT. In this case, the LLT quantity information can indicate the quantity of the LLT for each AC (Access Class) to which the TID belongs. For example, if TID X and TID Y belong to AC 1, the LLT quantity information can indicate the sum of the LLT quantities of each of TID X and TID Y as the quantity of the LLT used for AC 1.

[0219] Example 2

[0220] Example 2 relates to procedures for triggering LLT information and for sending and receiving LLT information. That is, Example 2 specifies the LLT information triggering procedure and the LLT information sending and receiving procedure as in Example 1 and its sub-examples. As mentioned above, the STA can be a non-AP STA or an AP.

[0221] In this disclosure, a STA (e.g., an AP, etc.) can acquire / initiate a TXOP by sending a frame / PPDU. Another STA (e.g., a non-AP STA) can receive one or more PPDUs from the STA (e.g., an AP), which include frames that trigger low-latency service (LLT) information within the TXOP. Here, one or more PPDUs may include frames (e.g., QoS data frames) addressed to one or more STAs.

[0222] Alternatively, a predefined time (e.g., SIFS, PIFS) may exist between the PPDU / frame that triggers the LLT information and the frame that includes the LLT information in response to the PPDU / frame.

[0223] A STA (e.g., an AP) that receives one or more frames / PPDUs containing LLT information can send a frame / PPDU that triggers an LLT based on the LLT information to another STA (e.g., a non-AP STA).

[0224] An STA that receives one or more frames including LLT information can perform a frame detection operation and obtain LLT information for each STA through the frame detection operation. One or more STAs can prepare for PPDU / frame transmission, which can trigger LLT using the obtained LLT information. Because the configuration of LLT information is described in Example 1-1, redundant descriptions will be omitted. An STA that receives a PPDU / frame that triggers LLT can perform frame detection and prepare for LLT transmission through frame detection.

[0225] As an example of this disclosure, within the TXOP set by STA 1, STA 2 can send frames including LLT information to STA 1 and / or one or more other STAs. The LLT information can be sent to STA 1 via a response frame to the frame that triggered the LLT information, or via another frame.

[0226] LLT information can be sent and received via at least one of the following: HT control field (e.g., A-control field), BA (block ACK) frame (e.g., BA control field of BA frame), or MAC header. For example, if LLT information is included in a BA frame, the BA frame can be defined as a new BA type.

[0227] Alternatively, the field including LLT information may be located after or on the BA information field of the BA frame. Alternatively, if the BA frame is a compressed BA, the segment number subfield of the block ACK start sequence control field may be set to a specific value to indicate that LLT information is included in the BA frame. Alternatively, if the BA frame is a multi-STA BA frame, the AID TID information field of the per AID TID information subfield may be set to a specific value to indicate that LLT information is included in the BA frame.

[0228] Example 3

[0229] Example 3 relates to a process for triggering LLT information using a specific frame. Here, the frame that triggers the LLT information is called an LLT polling frame, but is not limited thereto, and the name of the frame can be changed.

[0230] As an example of this disclosure, an LLT polling frame can be defined as a new control or management frame (e.g., an action frame). Alternatively or concurrently, an LLT polling frame can be defined as a trigger frame (e.g., an LLT polling trigger frame), and trigger variants of the LLT query frame can be defined as new trigger frame variants for LLT information triggers.

[0231] Alternatively, if the LLT polling frame is defined as a trigger frame, the LLT polling trigger frame can use the format of an existing trigger frame variant. Furthermore, the common information field of the LLT polling trigger frame may include information indicating that the LLT information has been triggered, and this information may be mapped to reserved bits in the common information field (e.g., reserved bit field, EHT reserved bit field, etc.).

[0232] For example, when sending a BSRP (Buffer Status Report Polling) trigger frame or a basic trigger frame, if the common information field includes information indicating that LLT information is being triggered, the STA can respond to the trigger frame by sending LLT information to the other STA that sent the trigger frame instead of a BSR.

[0233] For example, an LLT polling trigger frame can assign a RU to a specific STA, and one or more STAs can assign one or more RA (Random Access)-RUs that can be accessed using UORA (Uplink OFDMA-based Random Access).

[0234] Alternatively, the user information field used to allocate RU / bandwidth or RA-RU may include information indicating that it triggers LLT information. In this case, the information indicating that it triggers LLT information can be mapped to reserved bits in the user information field. This allows the use of the RU to be distinguished by a single trigger frame.

[0235] Example 3-1

[0236] Example 3 relates to rules associated with the response to an LLT polling frame when an LLT polling frame is sent to trigger LLT information. At least one rule associated with the response to the LLT polling frame, as described below, can be used / applied, and in this disclosure, the response frame / PDU sent by the STA responding to the LLT polling frame is referred to as an LLT indication.

[0237] As an example of this disclosure, an LLT indication may include at least one type of LLT information described above.

[0238] Alternatively, the LLT indication (i.e., the frame including the LLT indication) itself may include the presence of an LLT (i.e., an LLT that the STA is currently transmitting). Furthermore, the LLT indication itself can be interpreted as a request from one STA in a TXOP where another STA wants to transmit an LLT.

[0239] Here, if the STA does not have an LLT to send or does not want to send an LLT, the STA may not send an LLT indication. For example, an LLT indication can be a control frame, such as an existing ACK, CTS / CTS-to-Self, NDP, or a PPDU that does not include an MPDU.

[0240] Alternatively, the PPDU indicated by LLT may be a non-HT PPDU or a non-HT repeating PPDU.

[0241] Alternatively, to include more LLT information, one or more types of LLT information can be indicated via the A-control frame of the QoS empty frame.

[0242] As an example of this disclosure, a STA that sends an LLT indication may use a channel (including the primary channel) with a bandwidth size less than or equal to its supported bandwidth to send the LLT indication.

[0243] Alternatively, the bandwidth for transmitting the LLT indication may be less than the bandwidth of the PPDU that includes the LLT polling frame. Alternatively, the bandwidth for transmitting the LLT indication may be fixed to a specific value (e.g., 20 MHz, 40 MHz, etc.).

[0244] As an example of this disclosure, CCA can be performed when an LLT indication is sent. For example, an energy detection operation can be performed during the interval (e.g., SIFS) after receiving an LLT polling frame and before sending an LLT indication.

[0245] Alternatively, one or more 20 MHz channels that are busy due to CCA (e.g., punching) can be excluded, and LLT indications can be sent.

[0246] Alternatively, due to CCA, the following rules for LLT indication transmission can be applied.

[0247] - When the secondary 20 MHz channel is busy, the LLT indication may not be transmitted on the secondary 20 MHz channel. For example, the LLT indication may be transmitted only on the primary 20 MHz channel.

[0248] - If one or more of the 20MHz channels in the secondary 40MHz channel are busy, the LLT indication may not be transmitted on the secondary 40MHz channel.

[0249] - If one or more of the 20MHz channels in the secondary 80MHz channel are busy, the LLT indication may not be transmitted on the secondary 80MHz channel.

[0250] - If one or more of the 20MHz channels in the secondary 160MHz channel are busy, the LLT indication may not be transmitted on the secondary 160MHz channel.

[0251] In one example of this disclosure, an LLT indication may be sent based on information indicated in an LLT polling frame. In one example, the LLT polling frame may include information about the maximum bandwidth (e.g., the maximum bandwidth through which an LLT indication can be sent (e.g., 20, 40, 80, 160, 320 MHz)) and / or whether the channel through which the LLT indication is sent must include the primary channel.

[0252] Here, based on the indication that the channel transmitting the LLT indication does not include the LLT polling frame of the primary channel, the LLT indication can be transmitted through at least one secondary 20MHz channel. Alternatively, if the transmittable bandwidth is X MHz, the LLT indication can be transmitted only through Y MHz excluding the primary channel of X MHz. For example, if the transmittable bandwidth is 40 MHz, the LLT indication can be transmitted only through the secondary 20 MHz excluding the primary channel of 40 MHz.

[0253] In one example of this disclosure, when one or more other frames (e.g., QoS data frames) are transmitted simultaneously with LLT polling frames, one or more STAs (i.e., TXOP responders) that are receivers of the other or more frames may send ACK frames or LLTIs.

[0254] For example, suppose one or more STAs, as receivers of one or more other frames, send ACK frames. When a QoS data frame is sent along with an LLT polling frame, a new ACK policy can be defined in the QoS data frame. Here, the ACK policy can refer to an ACK policy that requests an ACK frame for the QoS data frame and allows a BA to respond later (referred to in this disclosure as the LLT ACK policy). For example, the LLT ACK policy can be indicated as the ACK policy when the ACK policy indication subfield value is set to a specific value (e.g., "01").

[0255] Furthermore, the A-MPDU including the MDPU with LLT ACK policy can be included in the UHR PPDU or the PPDU of a later version of the UHR. Additionally, one or more frames including LLT ACK policy and LLT polling frames can be sent and received together.

[0256] Alternatively, when LLTI transmission is not required, an ACK frame can be forced to be sent upon successful receipt of an LLT polling frame or one or more frames sent to itself. This approach can resolve issues related to LLTI not being sent or malfunctioning.

[0257] Figure 14 This is a diagram illustrating a process for transmitting LLTI using LLT polling frames according to an embodiment of the present disclosure. Figure 14 As shown, the AP can first obtain the TXOP via RTS / CTS switching, and then send one or more frames to one or more STAs via PPDU.

[0258] Here, the PPDU can be a MU PPDU, which sends LLT polling frames from RU 3, and an A-MPDU including one or more QoS data frames is sent from RU 4 to STA 1.

[0259] Furthermore, RU 3 can be configured as a broadcast RU, and one or more STAs can receive and acknowledge LLT polling frames from RU 3. Each STA receiving an LLT polling frame can use its supported bandwidth to send LLTI.

[0260] As an example of this disclosure, assume that all STAs want to send LLT. In this case, STA 1 and STA 3 support a bandwidth of 80 MHz, which is the bandwidth of the PPDU containing the LLT polling frame, and can use this to send LLTI. STA 2 supports a bandwidth of 40 MHz of the 80 MHz, which is the bandwidth of the PPDU containing the LLT polling frame, and can use this to transmit LLTI. Alternatively, STA 1 can send ACK frames even if LLTI transmission is not required.

[0261] In addition, the AP can perform an acknowledgment process for the STAs that send LLTI. For example, the AP can send an NFRP (NDP Feedback Report Polling) trigger frame to at least one STA, and the STA that sends LLTI can respond to the trigger frame by sending an NFR.

[0262] Furthermore, the AP that has received LLTI from STA 1, 2 and 3 can send trigger frames to STA 1, 2 and 3, and STA 1, 2 and 3 can send LLT to the AP based on the trigger frames.

[0263] Figure 15 This is a diagram used to explain a method of sending LLTI via LLT polling frames according to an embodiment of the present disclosure.

[0264] Figure 15 This is a diagram illustrating a process for transmitting LLTI using LLT polling frames according to an embodiment of the present disclosure. Figure 15 As shown, the AP can first obtain the TXOP via RTS / CTS switching, and then send one or more frames to one or more STAs via PPDU.

[0265] Here, the PPDU can be a MU PPDU, which sends LLT polling frames from RU 3, and an A-MPDU including one or more QoS data frames which is sent from RU 4 to STA 1.

[0266] Furthermore, RU 3 can be configured as a broadcast RU, and one or more STAs can receive and acknowledge LLT polling frames from RU 3. Each STA receiving an LLT polling frame can use its supported bandwidth to send LLTI.

[0267] like Figure 15 As shown, when LLTI transmission is not required, STA 1 can transmit ACK frames (e.g., BA, ACK) via the main channel. This allows the AP to transmit the next frame after the SIFS hold interval, even if STA 2 and STA 3 do not transmit LLTI.

[0268] For example, STA 2 supports a 40 MHz bandwidth and can use it to send LLTI to the AP. STA 3 supports an 80 MHz bandwidth and can also use it to send LLTI to the AP. In this case, if the primary channel is not used for LLTI transmission, STA 2 can send LLTI via a secondary 20 MHz channel excluding the PCH or a 40 MHz channel including the secondary 20 MHz channel. Furthermore, if the primary channel is not used for LLTI transmission, STA 3 can also send LLTI via a 60 MHz or 80 MHz channel excluding the primary channel and including at least one 20 MHz channel.

[0269] In addition, the AP can perform an acknowledgment process on the STA that sends the LLTI. For example, the AP can send an NFRP (NDP Feedback Report Polling) trigger frame to at least one STA, and the STA that sends the LLTI can respond to the trigger frame by sending an NFR.

[0270] Furthermore, the AP that has received LLTI from STA 1, 2 and 3 can send trigger frames to STA 1, 2 and 3, and STA 1, 2 and 3 can send LLT to the AP based on the trigger frames.

[0271] Example 4

[0272] Example 4 relates to a method for using a PHY header to trigger LLT information. At least one of the methods described below can be used.

[0273] As an example of this disclosure, the PHY header used to trigger LLT information may include a field for triggering the transmission of LLT information (i.e., an LLT information trigger field). The LLT information trigger field may indicate whether LLT information needs to be sent. As an example, the LLT information trigger field may be included in the SIG field of the PHY header (e.g., U-SIG field, UHR-SIG field, etc.).

[0274] When the PHY header includes information that triggers LLT information, a response from the STA to the PHY header is required, and therefore a rule associated with such a response is needed. At least one rule associated with such a response, as described below, can be used / applied, and in this disclosure, the response frame / PDU sent by the STA in response to the PHY header is referred to as an LLT indication.

[0275] As an example of this disclosure, an LLT indication may include at least one type of LLT information described above.

[0276] Alternatively, the LLT indication (i.e., the frame including the LLT indication) itself may include the presence of an LLT (i.e., meaning that an LLT is currently being transmitted by a STA). Furthermore, the LLT indication itself can be interpreted as a request from one STA in a TXOP where another STA wants to transmit an LLT.

[0277] Here, if the STA does not have an LLT to send or does not want to send an LLT, the STA may not send an LLT indication. For example, an LLT indication can be a control frame, such as an existing ACK, CTS / CTS to itself, NDP, or PPDU that does not include an MPDU.

[0278] Alternatively, to include more LLT information, one or more types of LLT information can be indicated via A-control frames in QoS empty frames.

[0279] As an example of this disclosure, a STA that sends an LLT indication may use a channel (including the primary channel) with a bandwidth size less than or equal to its supported bandwidth to send the LLT indication.

[0280] Alternatively, the bandwidth for transmitting the LLT indication may be less than the bandwidth of the PPDU that triggers the LLT information. Alternatively, the bandwidth for transmitting the LLT indication may be fixed to a specific value (e.g., 20 MHz, 40 MHz, etc.).

[0281] As an example of this disclosure, CCA can be performed when an LLT indication is sent. For example, an energy detection operation can be performed during the interval (e.g., SIFS) after receiving an LLT polling frame and before sending an LLT indication.

[0282] Alternatively, one or more 20 MHz channels that are busy due to CCA (e.g., punching) can be excluded, and LLT indications can be sent.

[0283] Alternatively, due to CCA, the following LLT indication transmission rules can be applied.

[0284] - If the secondary 20 MHz channel is busy, the LLT indication may not be transmitted on the secondary 20 MHz channel. For example, the LLT indication may be transmitted only on the primary 20 MHz channel.

[0285] - If one or more of the 20 MHz channels in the secondary 40 MHz channel are busy, the LLT indication may not be transmitted on the secondary 40 MHz channel.

[0286] - If one or more of the 20 MHz channels in the secondary 80 MHz channel are busy, the LLT indication may not be transmitted on the secondary 80 MHz channel.

[0287] - If one or more of the 20 MHz channels in the secondary 160 MHz channel are busy, the LLT indication may not be transmitted on the secondary 160 MHz channel.

[0288] In one example of this disclosure, the LLT indication may be sent based on information indicated in the LLT (or information included in the PHY header). In one example, the PHY header may include information about the maximum bandwidth (e.g., the maximum bandwidth through which the LLT indication can be sent (e.g., 20, 40, 80, 160, 320 MHz)) and / or whether the channel through which the LLT indication is sent must include the primary channel.

[0289] Here, based on the indication that the channel transmitting the LLT indication does not include the LLT polling frame of the primary channel, the LLT indication can be transmitted through at least one secondary 20MHz channel. Alternatively, if the transmittable bandwidth is X MHz, the LLT indication can be transmitted only through Y MHz excluding the primary channel of X MHz. For example, if the transmittable bandwidth is 40 MHz, the LLT indication can be transmitted only through the secondary 20 MHz excluding the primary channel of 40 MHz.

[0290] In one example of this disclosure, when one or more other frames (e.g., QoS data frames) are transmitted simultaneously with LLT polling frames, one or more STAs (i.e., TXOP responders) that are receivers of the other or more frames may send ACK frames or LLTIs.

[0291] For example, suppose one or more STAs, as receivers of one or more other frames, send ACK frames. When a QoS data frame is sent along with an LLT polling frame, a new ACK policy can be defined in the QoS data frame. Here, the ACK policy can refer to an ACK policy that requests an ACK frame for the QoS data frame and allows a BA to respond later (referred to in this disclosure as the LLT ACK policy). For example, the LLT ACK policy can be indicated when the ACK policy indication subfield value is set to a specific value (e.g., "01").

[0292] Furthermore, the A-MPDU including the MDPU with the LLT ACK policy can be included in the UHR PPDU or the PPDU of a later version of the UHR. Additionally, one or more frames including an indication of the LLT ACK policy and the LLT information in the triggering PHY header can be sent together.

[0293] Alternatively, when LLTI is not required, an Ack frame can be forcibly sent upon successful receipt of one or more frames sent to itself or upon receiving an instruction message that triggers LLT information. This approach can resolve issues related to LLTI not being sent or malfunctioning.

[0294] Figure 16 This is a diagram illustrating a method for sending LLTI using a PHY header according to an embodiment of the present disclosure.

[0295] like Figure 16 As shown, the AP can first obtain the TXOP via RTS / CTS switching, and then send one or more frames to one or more STAs via PPDU. In this example, the PHY header of the PPDU may include an LLT information trigger field. Then, an A-MPDU including one or more QoS data frames can be sent to one or more STAs.

[0296] Each STA that receives the LLT information trigger field can send the LLTI to the AP using its supported bandwidth.

[0297] As an example of this disclosure, assume that all STAs want to transmit LLT. STA 1 and STA 3 support an 80 MHz channel, which is the bandwidth of the PPDU, and can use it to transmit LLTI. STA 2 supports a 40 MHz bandwidth based on the 80 MHz bandwidth of the PPDU and is able to use it to transmit LLTI. Alternatively, STA 1 may also transmit ACK frames even if LLTI transmission is not required.

[0298] In addition, the AP can perform an acknowledgment process on the STA that sends the LLTI. For example, the AP can send an NFRP (NDP Feedback Report Polling) trigger frame to at least one STA, and the STA that sends the LLTI can respond to the trigger frame by sending an NFR.

[0299] Furthermore, the AP that has received LLTI from STA 1, 2 and 3 can send trigger frames to STA 1, 2 and 3, and STA 1, 2 and 3 can send LLT to the AP based on the trigger frames.

[0300] Figure 17 This is a diagram illustrating a method for sending LLTI using a PHY header according to an embodiment of the present disclosure.

[0301] like Figure 17 As shown, the AP can first obtain a TXOP via RTS / CTS switching, and then send one or more frames to one or more STAs via a PPDU. In this example, the PPDU is a MU PPDU, and the PHY header of the PPDU may include an LLT information trigger field. Then, an A-MPDU including one or more QoS data frames can be sent to one or more STAs.

[0302] Each STA that receives the LLT information trigger field can use its supported bandwidth to send an LTI. STA 1 can send an ACK frame to the main channel even if LLTI transmission is not required. This also allows the AP to send the next frame after the SIFS hold interval, even if STA 2 and STA 3 do not send LLTI.

[0303] STA 2 supports a 40 MHz bandwidth and can be used to send LLTI to the AP. STA 3 supports an 80 MHz bandwidth and can also be used to send LLTI to the AP. In this case, if the primary channel is not used for LLTI transmission, STA 2 can send LLTI by excluding the secondary 20 MHz channel of the PCH or by using a 40 MHz channel that includes the secondary 20 MHz channel. Furthermore, if the primary channel is not used for LLTI transmission, STA 3 can also send LLTI by excluding the primary channel by using a 60 MHz or 80 MHz channel that includes at least one 20 MHz channel.

[0304] In addition, the AP can perform an acknowledgment process on the STA that sends the LLTI. For example, the AP can send an NFRP (NDP Feedback Report Polling) trigger frame to at least one STA, and the STA that sends the LLTI can respond to the trigger frame by sending an NFR.

[0305] Furthermore, the AP that has received LLTI from STA 1, 2 and 3 can send trigger frames to STA 1, 2 and 3, and STA 1, 2 and 3 can send LLT to the AP based on the trigger frames.

[0306] Figure 18 This is a diagram illustrating a method for sending LLTI using a PHY header according to an embodiment of the present disclosure.

[0307] like Figure 18 As shown, the AP can first obtain the TXOP via RTS / CTS switching, and then send a trigger frame to STA 1 and STA 2. The AP can receive data based on the trigger frame from STA 1 and STA 2, and send a PPDU containing multi-STA block ACK frames to STA 1 and STA 2. In this disclosure, the PPDU may include a PHY header and an LLT information trigger field.

[0308] Each STA that receives the LLT information trigger field can send an LLTI to the AP using its supported bandwidth. If STA3 and STA4 want to send an LLT, the 80 MHz bandwidth of the PPDU can be used as a reference. STA4 supports 80 MHz bandwidth and can use this to send an LLTI to the AP. STA3 supports 40 MHz of the 80 MHz bandwidth of the PPDU and can use this to send an LLTI to the AP.

[0309] Alternatively, STA 1 and STA 2 may send ACK frames even if LLTI transmission is not required.

[0310] In addition, the AP can perform an acknowledgment process on the STA that sends the LLTI. For example, the AP can send an NFRP (NDP Feedback Report Polling) trigger frame to at least one STA, and the STA that sends the LLTI can respond to the trigger frame by sending an NFR.

[0311] Furthermore, the AP that has received LLTI from STA 3 and STA 4 can send trigger frames to STA 3 and STA 4, and STA 3 and 4 can send LLT to the AP based on the trigger frames.

[0312] Example 5

[0313] Example 5 relates to a method for modifying an existing trigger frame variant for LLT transmission.

[0314] In addition to or as a substitute for the frame-triggered LLT information / LLT method described in Embodiment 3, existing trigger frame variants (e.g., BSRP) can be used as is. In this case, information enabling the STA transmitting the LLT (hereinafter referred to as LL STA) to respond to the corresponding trigger frame variant can be indicated by at least one of the methods described below. For example, if the following methods are applied to the trigger frame, HE STA and EHTSTA may not be able to respond to the corresponding trigger frame, but are not limited thereto.

[0315] As an example of this disclosure, information enabling an LL STA to respond to a corresponding trigger frame variant can be indicated via a common information field. For example, information indicating that a corresponding trigger frame only triggers transmit / receive operations of an STA with an LLT can be mapped / set on reserved bits in the common information field (e.g., EHT reserved bits, special user information fields, etc.). Since the above information is commonly indicated via the common information field, overhead can be reduced.

[0316] As an example of this disclosure, information enabling the LL STA to respond to a corresponding trigger frame variant can be indicated via a user information field. This allows for the simultaneous triggering of transmissions and receptions by other STAs with the LL STA, and the trigger frame is not limited to a specific variant.

[0317] For example, setting a specific value on the AID12 field of the user information field can indicate that the corresponding RU (i.e., the RU assigned through the user information field, etc.) is an RU that the LL STA can access. For example, a specific value from 1 to 2007 can be used / selected or a reserved value for the relevant STA with a specific AID in the AID12 field can be reserved.

[0318] The RU assigned by the RU indicated by the special ADI12 field (e.g., the RU indicated by the RU assignment field) can be one or more LL STAs that can access via UORA.

[0319] When the AID12 field indicates the AID of a specific STA, one or more fields of the User Information field (including one or more reserved fields) can be used to indicate that the assigned RU is an RU that the LL STA can access.

[0320] If the AID12 field indicates that one or more RA-RUs (e.g., 0, 2045) are allocated, one or more reserved bits in the user information field can be used to indicate that the LL STA is able to access the allocated RU.

[0321] Figure 19 This is a diagram illustrating a BSR triggering method for LL STA according to an embodiment of the present disclosure.

[0322] like Figure 19 As shown, the AP can first obtain the TXOP via RTS / CTS switching, and then send one or more frames to one or more STAs via PPDU. In this disclosure, the PPDU can be a MU PPDU, and the BSRP trigger frame can be sent to RU 3, while an A-MPDU containing one or more QoS data frames can be sent to STA 1 through RU 4. Furthermore, the BSRP trigger frame can be sent to one or more LL STAs using the method described above.

[0323] For example, RU 3 can be set as a broadcast RU, and one or more STAs can receive and acknowledge BSRP trigger frames through RU 3. Here, RU 2 and RU 3, assigned by the BSRP trigger frame, can be assigned as RA-RUs, and RA-RUs can be assigned to LL STAs according to the method described above.

[0324] Therefore, STA 2 and STA 3 can access one or more RA-RUs. STA 2 can successfully access RU 2 and send a BSR, and STA 3 can successfully access RU 3 and send a BSR.

[0325] STA 1 can send BA frames in response to QoS data. Additionally, if the QoS data includes an Ack policy that does not require immediate BA (e.g., block Ack), STA 1 can also send a BSR if it successfully completes access procedures at RU 2 and RU 3.

[0326] Subsequently, it was confirmed that the APs receiving BSR from STA 2 and STA 3 can send trigger frames to STA 2 and STA 3, and STA 2 and STA 3 can receive LLT based on the trigger frames.

[0327] Alternatively, if the STA transmits an LLT within the current TXOP, the STA can receive a trigger frame variant to which the above method has been applied and send a response frame. Meanwhile, there may be STAs that do not need to transmit an LLT. Therefore, a method can be applied to identify and select STAs that do not need to transmit an LLT.

[0328] As an example of this disclosure, using one or more of the above-described LLTI transmission methods, only the STA that sends the LLTI can send a response to a subsequent trigger frame variant.

[0329] Figure 20 This is a diagram used to explain a response method of LL STA based on LLTI according to an embodiment of the present disclosure.

[0330] like Figure 20 As shown, the AP can first obtain a TXOP via RTS / CTS switching, and then send one or more frames to one or more STAs via a PPDU. In this disclosure, the PPDU can be a SU PPDU or a MU PPDU, and the PHY header can include an LLT information trigger field instruction or an LLT polling frame. Furthermore, the AP can send an A-MPDU that includes one or more QoS data frames.

[0331] Each STA that receives the LLT information trigger field can send an LLTI to the AP using its supported bandwidth. Alternatively, STA 1 can send an ACK frame even if it does not need to send an LLTI.

[0332] The AP can then send a BSRP trigger frame to at least one STA to trigger a BSR in order to check the STA's LLT information. One or more LL STAs can receive the BSRP trigger frame using at least one of the methods described above.

[0333] As an example of this disclosure, STAs (i.e., STA 1, STA 2, and STA 3) that transmit LLTI in a previous sequence using the method described above can send a response to a BSRP trigger frame.

[0334] In this example, RU 1 and RU 2, which are assigned by the BSRP trigger frame, are assigned as RA-RUs, and the above method can be used to assign RA-RUs to LL STAs.

[0335] Therefore, STA 1, STA 2, and STA 3 can attempt to access one or more RA-RUs. STA 2 can successfully access RU 2 and send a BSR, and STA 3 can successfully access RU 3 and send a BSR. Subsequently, the AP that has confirmed receiving a BSR from STA 2 and STA 3 can receive an LLT from STA 2 or STA 3 via a trigger frame.

[0336] As an example of this disclosure, Figure 19 and Figure 20 The BSRP trigger frame in the code can be replaced by the NFRP trigger frame.

[0337] Here, the TB feedback NDP (e.g., HE TB feedback NDP) can be used in response to an NFRP trigger frame. When transmitting the current TB feedback NDP, the STA can request resources based on a resource request buffer threshold transmitted by the AP via a feedback state (e.g., 0 or 1). That is, the STA can perform mapping to another HE-LTF subcarrier depending on whether the value associated with its buffer exceeds the threshold.

[0338] Therefore, one or more elements described below can be considered to enable LL STA to send NFR's FEEDBACK_STATUS.

[0339] The size of FEEDBACK_STATUS can be determined based on specific criteria (e.g., conditions related to the number of information types, the number of combinations between information, etc.). For example, if the criteria are information about the amount of LLT (i.e., the quantity of LLT) and delay information, FEEDBACK_STATUS can be set based on whether a combination of the quantity of LLT and the delay information is satisfied (i.e., a total of 4 combinations) (e.g., 0 to 3). As another example, it can be set based on two combinations (e.g., 0 to 1) based on whether two conditions related to the quantity of LLT (e.g., the quantity in bytes) and the delay information are satisfied.

[0340] Here, the delay information may include information about when the LLT must be sent.

[0341] For example, delay information (e.g., delay information in Xus) can indicate the time from when the LLT information is sent or when the transmission is completed until the LLT must be successfully sent.

[0342] As another example, delay information can indicate when a LLT must be successfully transmitted. For instance, delay information can be indicated as an absolute time using a timestamp (TSF).

[0343] Alternatively, if there are LLTs for one or more IDs, the delay information can indicate the earliest time point among the LLTs for one or more IDs.

[0344] Alternatively, if an LLT exists for one or more IDs, the delay information can indicate the timing information used for each ID.

[0345] Alternatively, one or more delay information may be indicated. For example, if the current remaining time relative to the target time when the LLT transmission is to be completed is longer than the remaining time calculated from the delay information, then LLT information or / and LLT may not be sent.

[0346] Alternatively, if there are LLTs for one or more IDs, the information about the quantity of the LLTs can indicate the quantity of the LLTs for all the corresponding IDs. For example, the information about the quantity of the LLTs can indicate the sum of the quantities of the LLTs for each ID.

[0347] Alternatively, if there are LLTs for one or more IDs, information about the amount of LLTs can indicate the amount of LLTs used for each ID.

[0348] Alternatively, when a TID is used for an LLT, information about the quantity of the LLT can indicate the quantity of the LLT used for each Access Class (AC) to which the corresponding TID belongs. For example, if TID X and TID Y belong to AC 1, the information about the quantity of the LLT can indicate the sum of the quantities of the LLTs used for TID X and TID Y as the quantity of the LLT used for AC 1.

[0349] Alternatively, information about the quantity of LLT can be indicated through the BSR control field, and information about the quantity of one or more LLTs can also be indicated.

[0350] Alternatively, FEEDBACK_STATUS itself may indicate the existence of an LLT. In other words, FEEDBACK_STATUS may indicate the existence of an LLT that the STA currently needs to send.

[0351] Furthermore, FEEDBACK_STATUS can be interpreted as a request from one STA to send an LLT from another STA in a TXOP. For example, if the FEEDBACK_STATUS value is set to 1, it can indicate that an LLT exists. Conversely, if FEEDBACK_STATUS is set to 0, it can indicate that an LLT does not exist. In this case, a new feedback type can be defined in the NFRP trigger frame (e.g., the value of the feedback type-related subfield is set to 1).

[0352] Alternatively, various criteria can be applied to specific types of information. For example, various criteria related to different values ​​(e.g., 2ms, 3ms, etc.) can be applied to delay information.

[0353] Alternatively, the various combinations of FEEDBACK_STATUS can be distinguished based on the feedback type indicated in the NFRP trigger frame. For example, if "feedback type=1", this could represent delay information, and if "feedback type=2", this could represent a combination of delay information and LLT values, etc.

[0354] Alternatively, the RU_TONE_SET_INDEX applied to the LTF subcarrier mapping can vary with the number of FEEDBACK_STATUS values. For example, when "FEEDBACK_STATUS=2", the previously used LTF subcarrier mapping corresponding to "RU_TONE_SET_INDEX=3" and "FEEDACK_STATUS=1" can be applied. That is, the number of LTF subcarrier mapping combinations that can be used for a single STA can be increased.

[0355] Figure 21 This is a diagram illustrating a response method of LL STA based on LLTI according to an embodiment of the present disclosure.

[0356] like Figure 21 As shown, the AP can first obtain a TXOP via RTS / CTS switching, and then send one or more frames to one or more STAs via a PPDU. In this disclosure, the PPDU can be a SU PPDU or a MU PPDU, and the PHY header can include an LLT information trigger field indicating an LLT polling frame. Furthermore, the AP can send an A-MPDU that includes one or more QoS data frames.

[0357] Each STA that receives the LLT information trigger field can send an LLTI to the AP using its supported bandwidth. Alternatively, STA 1 can send an ACK frame even if it does not need to send an LLTI.

[0358] The AP can send an NFRP trigger frame to at least one LL STA to trigger an NFR check of the STA's LLT information. Furthermore, at least one LL STA can receive the NFRP trigger frame using at least one of the methods described above. Specifically, in this example, only STAs that sent LLTIs in the previous sequence using the methods described above (i.e., STA 1, STA 2, STA 3) can respond to the NFRP trigger frame.

[0359] In this example, the above method can be used for subcarriers allocated by NFRP-triggered frames. Therefore, as Figure 21 As shown, STA 2 and STA 3 can transmit NFRs via their allocated subcarriers. Subsequently, the AP that has confirmed receiving NFRs from STA 2 and STA 3 can receive LLTs from STA 2 or STA 3 via a trigger frame.

[0360] Through various embodiments of this disclosure, a TXOP holder can send an LLT on request by receiving LLT information from one or more STAs, thereby reducing latency and overhead associated with LLT transmission.

[0361] The above embodiments combine the elements and features of this disclosure in a predetermined form. Unless otherwise expressly stated, each element or feature should be considered optional. Each element or feature can be implemented without combination with other elements or features. Furthermore, embodiments of this disclosure may include combinations of certain elements and / or features. The order of operations described in the embodiments of this disclosure may be changed. Some elements or features of one embodiment may be included in other embodiments, or may be replaced by corresponding elements or features of other embodiments. It is clear that embodiments may include combinations of claims where there is no explicit dependency in the claims, or may be included as new claims by amendment after the application.

[0362] It will be apparent to those skilled in the art that this disclosure may be practiced in other specific forms without departing from the essential characteristics of this disclosure. Therefore, the foregoing detailed description should not be construed as restrictive in every respect, but rather as illustrative. The scope of the invention should be determined by a reasonable interpretation of the appended claims, and all variations within the equivalent scope of this disclosure are included within the scope of the invention.

[0363] The scope of this disclosure includes software or machine-executable commands (e.g., operating systems, applications, firmware, programs, etc.) that operate in a device or computer according to methods of various embodiments, and non-transitory computer-readable media that store such software or commands and can be executed in a device or computer. Commands that can be used to program a processing system to perform 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 using a computer program product including such a storage medium. The storage medium may include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid-state storage devices, and may include non-volatile memory, such as one or more disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory may optionally include one or more storage devices located remote from the processor. Alternatively, the non-volatile memory devices in the memory may include non-transitory computer-readable storage media. The features described in this disclosure can be stored in any machine-readable medium to control the hardware of a processing system and can be integrated into software and / or firmware that allows the processing system to interact with other mechanisms using results from embodiments of this disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0364] [Industrial Applicability]

[0365] The methods presented in this disclosure have been specifically described in the example of application to IEEE 802.11-based systems, but can also be applied to various wireless LAN or wireless communication systems other than those based on IEEE 802.11.

Claims

1. A method comprising: The first station (STA) receives the first physical layer protocol data unit (PPDU) including a polling frame from the access point (AP). Based on the polling frame, the first STA sends a first frame related to the first low-latency service (LLT) to the AP through a first channel including the main channel; as well as The first STA sends the first LLT to the AP during the AP's transmission opportunity. The polling frame includes information related to the maximum bandwidth of the channel used for LLT transmission.

2. The method according to claim 1, wherein: The first channel is identified when the first STA performs an idle channel assessment (CCA) for the transmission of the first frame.

3. The method according to claim 1, wherein: The bandwidth of the first channel is less than or equal to the maximum bandwidth.

4. The method according to claim 1, wherein: Based on receiving the first trigger frame from the AP, the first STA sends the first LLT to the AP.

5. The method according to claim 1, wherein: Based on the first PPDU comprising a data frame, at least one of the first frame and an acknowledgment (ACK) frame for the data frame is sent to the AP.

6. The method according to claim 1, wherein: The polling frame includes information indicating whether the primary channel is included on the first channel.

7. The method according to claim 1, wherein: The first frame includes information about the first LLT, and Information about the first LLT includes at least one of the following: information about the existence or non-existence of the first LLT, identification information of the first LLT, information about the time point at which the first LLT transmission is to be completed, and information about the quantity of the first LLT.

8. The method according to claim 1, wherein: The second frame associated with the second LLT is transmitted from the second STA to the AP via the second channel, and The polling frame includes information indicating whether the primary channel is included on the second channel.

9. The method according to claim 1, wherein: The AP sends a second trigger frame to the first STA to check whether the first frame has been sent. as well as Based on the second trigger frame, information indicating that the first frame has been sent is transmitted from the first STA to the AP.

10. The method according to claim 1, wherein: The second PPDU including the first frame includes a non-HT (high throughput) PPDU or a non-HT replicated PPDU.

11. The method according to claim 1, wherein: The AP is the TXOP holder, and The first STA is a TXOP responder.

12. A first station (STA), comprising: At least one transceiver; as well as At least one processor is connected to the at least one transceiver. Wherein, the at least one processor is configured to: Receive the first physical layer protocol data unit (PPDU) including polling frames from the access point (AP); Based on the polling frame, a first frame related to the first low-latency service (LLT) is sent to the AP via a first channel including the primary channel; and During the transmission opportunity of the AP, the first LLT is sent to the AP. The polling frame includes information related to the maximum bandwidth of the channel used for LLT transmission.

13. A method comprising: The access point (AP) sends a first physical layer protocol data unit (PPDU) including a polling frame to at least one station (STA). Based on the polling frame, the AP receives a first frame related to the first low-latency service (LLT) from the first STA among the at least one STA via a first channel including the main channel; as well as The AP receives the first LLT from the first STA during its transmission opportunity. The polling frame includes information related to the maximum bandwidth of the channel used for LLT transmission.

14. An access point (AP), comprising: At least one transceiver; as well as At least one processor is connected to the at least one transceiver. Wherein, the at least one processor is configured to: Send a first physical layer protocol data unit (PPDU) including a polling frame to at least one station (STA). Based on the polling frame, a first frame related to a first low-latency service (LLT) is received from a first STA among the at least one STA via a first channel including a primary channel; and During the transmission opportunity of the AP, the first LLT is received from the first STA. The polling frame includes information related to the maximum bandwidth of the channel used for LLT transmission.

15. A processing device configured to control a first station (STA) in a wireless LAN system, the processing device comprising: At least one processor; as well as At least one computer memory, operatively connected to the at least one processor and storing instructions that perform operations based on execution by the at least one processor, the operations including: The first station (STA) receives the first physical layer protocol data unit (PPDU) including a polling frame from the access point (AP). Based on the polling frame, the first STA sends a first frame related to the first low-latency service (LLT) to the AP through a first channel including the primary channel; and The first STA sends the first LLT to the AP during the AP's transmission opportunity. The polling frame includes information related to the maximum bandwidth of the channel used for LLT transmission.

16. At least one non-transitory computer-readable medium, said non-transitory computer-readable medium storing at least one instruction, in, The at least one instruction executable by at least one processor controls the devices in the wireless LAN system to: The first station (STA) receives the first physical layer protocol data unit (PPDU) including a polling frame from the access point (AP). Based on the polling frame, the first STA sends a first frame related to the first low-latency service (LLT) to the AP through a first channel including the main channel; as well as The first STA sends the first LLT to the AP during the AP's transmission opportunity. The polling frame includes information related to the maximum bandwidth of the channel used for LLT transmission.

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