Method and apparatus for transmitting and receiving data in a wireless LAN system

Abstract

A method and apparatus for transmitting and receiving data in a wireless LAN system are disclosed. The method according to an embodiment of the disclosure can include the steps of transmitting, by a first apparatus, a PPDU to a second apparatus to allow data transmission of the second apparatus within a TXOP obtained by the first apparatus, and performing channel access after the TXOP is terminated by the first apparatus.

Description

Technical Field

[0001] This disclosure relates to a method and apparatus for transmitting and receiving data 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 technologies, the IEEE 802.11 series of standards can be referred to as Wi-Fi. For example, recent technologies introduced to 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 are being researched for multi-access point (AP) coordination and multiple-input multiple-output (MIMO) to support increased bandwidth, efficient utilization of multiple bands, and increased spatial flow. In particular, various technologies are being investigated 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 objective of this disclosure is to provide a method and apparatus for one or more other devices to send and receive data (e.g., low-latency services / packets, etc.) within a transmission opportunity (TXOP) obtained by a particular device.

[0006] In addition, an additional technical objective of this disclosure is to provide a method and apparatus for channel access between a device providing a TXOP and a device receiving a TXOP after the TXOP has been terminated.

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

[0008] Technical solution

[0009] A method according to one aspect of this disclosure may include: a first device sending a Physical Protocol Data Unit (PPDU) to a second device to allow data transmission by the second device within a Transmission Opportunity (TXOP) obtained by the first device; and the first device performing channel access after the TXOP has terminated. Channel access via the first device can be performed with a higher priority than channel access performed by other devices, including the second device.

[0010] The method according to an additional aspect of this disclosure may include: receiving a Physical Protocol Data Unit (PPDU) from a first device by a second device to allow data transmission by the second device within a Transmission Opportunity (TXOP) obtained by the first device; and performing channel access by the second device after the TXOP has terminated. Channel access via the second device can be performed with a lower priority than channel access performed by other devices, including the first device.

[0011] Beneficial effects

[0012] According to embodiments of this disclosure, even devices that have not yet obtained TXOP can quickly transmit data (e.g., low-latency services / packets, etc.), thereby reducing latency and improving wireless communication efficiency.

[0013] Furthermore, according to embodiments of this disclosure, even after the TXOP is terminated, it is possible to improve fairness regarding channel access between the device providing the TXOP and the device receiving the TXOP.

[0014] The effects achievable by this disclosure are not limited to those described above, and other effects not described herein can be clearly understood by those skilled in the art from 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 7This 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 The diagram illustrates the EDCA parameter set elements applicable to the wireless LAN system of this disclosure.

[0025] Figure 10 The diagram illustrates the MU EDCA parameter set elements applicable to the wireless LAN system disclosed herein.

[0026] Figure 11 This is a diagram illustrating issues related to LLT transmission in DL (downlink) TXOP.

[0027] Figure 12 This is a diagram illustrating issues related to LLT transmission in UL (uplink) TXOP.

[0028] Figure 13 This is a diagram illustrating a method for an AP to send LLT information to a STA 1 according to an embodiment of the present disclosure.

[0029] Figure 14 This disclosure relates to a method for sending LLT information using an HT control field (e.g., LLT information control with A control) according to an embodiment of the present disclosure.

[0030] Figure 15 This is a diagram illustrating the configuration of a BA frame containing LLT information.

[0031] Figure 16 This is a diagram illustrating a process for sending and receiving BA frames including LLT information according to an embodiment of the present disclosure.

[0032] Figure 17 This is a diagram illustrating the configuration of an LLT BA frame according to an embodiment of the present disclosure and the process for sending and receiving LLT BA frames.

[0033] Figure 18 This is a diagram illustrating the configuration of an LLT BA frame for multiple TIDs and the process for sending and receiving LLT BAs according to an embodiment of the present disclosure.

[0034] Figure 19 This is a diagram illustrating a method for sending LLT information using a MAC header according to an embodiment of the present disclosure.

[0035] Figure 20This disclosure relates to a method for sending and receiving LLT information via existing frames or new frames, according to one embodiment of the present disclosure.

[0036] Figure 21 This is a diagram illustrating a method for triggering LLT transmission using a trigger frame according to an embodiment of the present disclosure.

[0037] Figure 22 This is a diagram illustrating a method for triggering LLT transmission using a trigger frame according to an embodiment of the present disclosure.

[0038] Figure 23 This is a diagram illustrating a method for triggering an LLT to a TXOP responder according to an embodiment of the present disclosure.

[0039] Figure 24 This is a diagram illustrating a method for triggering LLT information transmission using a control field according to an embodiment of the present disclosure.

[0040] Figure 25 This is a diagram illustrating a method for triggering LLT information transmission using a PHY header according to an embodiment of the present disclosure.

[0041] Figure 26 This is a diagram illustrating a method for triggering an LLT to a TXOP responder according to an embodiment of the present disclosure.

[0042] Figure 27 This is a diagram illustrating a method for triggering an LLT to a TXOP responder according to an embodiment of the present disclosure.

[0043] Figure 28 This is a diagram illustrating a channel access method according to an embodiment of the present disclosure.

[0044] Figure 29 This is a diagram illustrating a channel access method according to an embodiment of the present disclosure.

[0045] Figure 30 This is a diagram illustrating a method for sending and receiving data according to an embodiment of the present disclosure.

[0046] Figure 31 This is a diagram illustrating a method for sending and receiving data according to an embodiment of the present disclosure. Detailed Implementation

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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”.

[0052] 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.

[0053] The technical features that can be applied to examples of this disclosure will be described below.

[0054] Figure 1 The figure shows a block diagram of a wireless communication device according to an embodiment of the present disclosure.

[0055] 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.

[0056] Figure 1 The devices 100 and 200 shown in the diagram can be referred to as stations (STAs). For example, Figure 1 The 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.

[0057] refer to Figure 1 The first device 100 and the second device 200 can transmit and receive radio signals via various wireless LAN technologies (e.g., the 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.

[0058] 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.

[0059] 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 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 relating 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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 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). 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. One or more transceivers 106, 206 may convert the user data, control information, wireless signals / channels, etc., processed by one or more processors 102, 202 from baseband signals to RF band signals. Therefore, one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

[0065] For example, one of STA 100 and 200 can perform the expected operation of an AP, and the other of STA 100 and 200 can perform the expected operation of a non-AP STA. For example, 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., preamble 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.

[0066] In the following text, downlink (DL) can refer to a link used for communication from an AP STA to a non-AP STA, and can be used to send and receive DL PPDUs / packets / signals. 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 can be used to send and receive UL PPDUs / packets / signals. In UL communication, the transmitter can be part of a non-AP STA, and the receiver can be part of an AP STA.

[0067] Figure 2 This is a diagram illustrating an exemplary structure of a wireless LAN system to which this disclosure can be applied.

[0068] 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.

[0069] 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 consisting of only two STAs. For instance, assuming other components are omitted, BSS1 consisting only of STA1 and STA2, or BSS2 consisting only of 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 access to the Distributed System (DS) is not allowed, thus forming a self-contained network.

[0070] 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).

[0071] 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.

[0072] DS refers to the structure of BSS interconnection. 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.

[0073] 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.

[0074] An AP enables access to a DS via WM for its associated non-AP STA, and also refers to 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.

[0075] 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.

[0076] In addition to the DS structure described above, an Extended Service Set (ESS) can be configured to provide broad coverage.

[0077] 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 mobile STAs can move from one BSS to another BSS (within the same ESS) that 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.

[0078] 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 self-organizing networks operate in locations where ESS networks exist, 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.

[0079] Figure 3 This is a diagram used to explain the link setup process to which this disclosure can be applied.

[0080] For a STA to establish a link to the network and send / receive data, the process first involves network discovery, authentication, association establishment, and, importantly, security authentication. 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.

[0081] 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. The process by which the STA identifies compatible networks and identifies networks existing in a specific area before participating in the wireless network is called scanning.

[0082] 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).

[0083] 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 periodically sent 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 periodically send them, 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.

[0084] 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.

[0085] 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.

[0086] 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, as well as additional information that can be replaced with other information or further included.

[0087] 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.

[0088] 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 the AP sending an association response frame to the STA in response.

[0089] 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. This corresponds to some examples of information that can be included in association request / response frames, and can be replaced with other information or further supplementary information.

[0090] 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 can be referred to as the first authentication process. The security setup process in step S340 can also be simply referred to as the authentication process.

[0091] 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.

[0092] Figure 4 This is a diagram used to explain the retreat process to which this disclosure can be applied.

[0093] In wireless LAN systems, the basic access mechanism for Media Access Control (MAC) is Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA). CSMA / CA is also known as the Distributed Coordination Function (DCF) of IEEE 802.11 MAC, and 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 it is determined that the medium is idle, frame transmission is initiated through the corresponding medium. On the other hand, if the medium is detected to be occupied or busy, the corresponding AP and / or STA does not initiate its own transmission, and a delay period (e.g., a random backoff period) can be set for medium intervention, and frame transmission can be attempted after waiting. By applying a random backoff period, collisions can be minimized because several STAs are expected to attempt frame transmission after waiting for different time periods.

[0094] 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 use 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 allows QoS data to be transmitted in both contention-based (CP) and contention-free (CFP) periods.

[0095] refer to Figure 4 This section describes the operation based on a random backoff period. When a occupied / busy medium becomes idle, several STAs may 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 ​​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 data transmission is successful, and when data transmission is successful, the CWmin value is reset. The values ​​of CW, CWmin, and CWmax are preferably set to 2.n -1 (n = 0, 1, 2, ...).

[0096] 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; when the medium becomes free, it resumes the remaining countdown.

[0097] 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 then performs a countdown on the backoff slot based on a random backoff count value selected by each STA. It is assumed that STA2 selects the minimum backoff count value, and STA1 selects 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 the backoff count and starts frame transmission is illustrated. STA1 and STA5 temporarily stop the countdown and wait, while STA2 occupies the medium. When STA2 finishes occupying the medium and the medium 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 occupies 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 before starting frame transmission. 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 may 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.

[0098] like Figure 4As shown in the examples, data frames are frames used to transmit data forwarded to higher layers, and can be sent after a backoff performed after the DIFS (Distributed Information Function) begins to elapse when the medium becomes idle. Additionally, management frames are frames used to exchange management information that is not forwarded to higher layers, and can be sent after a backoff performed after an IFS (Information Function Sequence) 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), allow to 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.

[0099] 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, the frames that can use AIFS[i] can be data frames, management frames, or control frames other than response frames.

[0100] Figure 5 This is a diagram used to explain the CSMA / CA-based frame transmission operation to which this disclosure can be applied.

[0101] 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 available 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 a period during which the STA receiving the NAV value is prohibited from accessing the media. For example, the NAV can be configured based on the value of the "Duration" field in the MAC header of the frame.

[0102] exist Figure 5In the example, it is assumed 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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 though 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 use the duration information included in the new frame to update the NAV timer. STA3 does not attempt channel access before the NAV timer expires.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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 may consist only 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) 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.)) may be included between the L-SIG field and the data field.

[0112] 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.

[0113] 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.

[0114] The data field may include a SERVICE field, a Physical Layer Service Data Unit (PSDU), and a PPDU TAIL bit, as well as 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 layers. The PPDU TAIL bit 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.

[0115] MAC PDUs are defined according to various MAC frame formats, and a basic MAC frame consists of a MAC header, frame body, and frame check sequence (FCS). MAC frames can be composed of MAC PDUs and are transmitted / received through the PSDU in the data portion of the PPDU frame format.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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)).

[0120] 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).

[0121] 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)).

[0122] 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), while it is not included in the HE PPDU format for single-user (SU). 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.

[0123] 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.

[0124] 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.

[0125] Compared to EHT MU PPDU, Figure 7In (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.

[0126] 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.

[0127] 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.

[0128] 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 preamble tones.

[0129] 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.

[0130] For example, A uncoded bits can be sent via U-SIG. The first symbol of U-SIG (e.g., U-SIG-1) can send the first X bits of the total A bits, and the second symbol of U-SIG (e.g., U-SIG-2) can send the remaining Y bits of the total A bits. 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.

[0131] 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.

[0132] 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.

[0133] 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 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.

[0134] 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.).

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.).

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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).

[0143] 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.

[0144] 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.

[0145] 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. MRUs (multiple RUs) are distinguished from multiple individual RUs and correspond to a group of subcarriers composed of multiple RUs. For example, an MRU can be defined as 52+26-tone, 106+26-tone, 484+242-tone, 996+484-tone, 996+484+242-tone, 2×996+484-tone, 3×996-tone, or 3×996+484-tone. Furthermore, the multiple RUs constituting an MRU can be continuous or non-contiguous in the frequency domain.

[0146] The specific size of the 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 or 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, ...).

[0147] 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 of 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.

[0148] Trigger Frame

[0149] Figure 8 This is a diagram illustrating an example format of the trigger frame that can be applied to this disclosure.

[0150] 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 additional information required by the STA, which sends a TB PPDU in response. The trigger frame may include common information and user information list fields in the frame body.

[0151] Common information fields are information that are commonly used in 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 TFs), CS (channel sensing) request, UL BW (bandwidth), HE / EHT P160, specific user information field flags, etc.

[0152] 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.

[0153] In public information, the trigger-related public information subfields may include information that can be optionally included based on the trigger type.

[0154] Specific user information fields can be included in the trigger frame. Specific user information fields do not include user-specific information, but do include extended public information not provided in the public information fields.

[0155] The user information list includes zero or more user information fields. Figure 8 The illustration shows an example of the EHT variant user information field format.

[0156] The AID12 subfield essentially indicates that it is a user information field for a STA with the corresponding AID. Additionally, 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 specific user information field. A specific 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 specific user information field can be identified by an AID12 value of 2007, and the specific user information field flag subfield within the public information field can indicate whether a specific user information field is included.

[0157] 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 160MHz) subfield of the user information field, the UL BW subfield of the public information field, etc.

[0158] EDCA channel access

[0159] The EDCA channel access protocol adds four independent enhanced distributed channel access functions (ADCAF) to the DCF process to provide differentiated priority for services that are to be transmitted using four different access classes (AC).

[0160] During the EDCA backoff process, each EDCAF maintains a MAC variable CW[AC], which is initialized to the value of the parameter CWmin[AC] for the AC of the corresponding EDCAF.

[0161] The TXNAV timer is a single timer shared by the ADCAF within the STA and is initialized to the duration of the / ID field of the frame most recently successfully transmitted by the TXOP holder (excluding PS polling frames). The TXNAV timer counts down from the time when the transmission of the PPDU including the frame ends.

[0162] When the medium on the main channel is busy, such as when indicated by physical carrier sensing (CS), virtual CS, etc., a backoff process via EDCAF can be performed.

[0163] Three modes of EDCA TXOP are defined: EDCA TXOP Start, EDCA TXOP Sharing, and EDCA TXOP Multi-Frame Switching Sequence. TXOP Start occurs when the EDCA rules allow access to the medium. EDCA TXOP Sharing occurs when an EDCAF within an AP supporting DL MU-MIMO acquires access to the medium, making that AC the primary AC, and the MU PPDU sent during TXOP includes traffic from queues associated with another AC. TXOP Multi-Frame Switching Sequence occurs when an EDCAF holds rights to access the medium.

[0164] Each EDCAF maintains a backoff counter with values ​​measured during the backoff time slot. When the backoff process begins, the backoff counter is set to a randomly selected integer value using a uniform distribution of values ​​ranging from 0 to CW[AC].

[0165] For each EDCAF, the EDCAF operation is performed on the main channel at predefined time slot boundaries. Here, at the time slot boundaries, each EDCAF decides to perform only one of the following functions: i) decrement the backoff counter, ii) initialize TXOP, iii) invoke the backoff procedure by deciding not to transmit, iv) invoke the backoff procedure due to internal collision, or v) take no action. However, if the backoff counter used for the corresponding EDCAF has a non-zero value at each time slot boundary, then each EDCAF decrements the backoff counter.

[0166] When one of the STA's EDCAFs is allowed to initiate a TXOP, the STA performs one of the following actions: a) If the secondary channel, secondary 40MHz channel, and secondary 80MHz channel are idle during the PIFS period immediately preceding the start of TXOP, the STA transmits a 160MHz or 80+80MHz masked PPDU.

[0167] b) If both the secondary channel and the secondary 40MHz channel are idle during the PIFS period immediately preceding the start of TXOP, the STA transmits an 80MHz masked PPDU on the primary 80MHz channel.

[0168] c) Immediately before the start of TXOP, if 1) a PPDU is transmitted in the 2.4 GHz band, or 2) otherwise, if the secondary channel is idle during the PIFS period, the STA transmits a 40MHz masked PPDU on the primary 40MHz channel.

[0169] d) The STA transmits a 20MHz masked PPDU on the main 20MHz channel.

[0170] e) STA does not send any content and invokes the backoff procedure for EDCAF.

[0171] f) Immediately before the start of TXOP, if the secondary TVHT_W channel and the secondary TVHT_2W channel are idle during the PIFS period, the STA sends a TVHT_4W or TVHT_2W+2W mask PPDU.

[0172] g) If the secondary TVHT_W channel is idle during the PIFS period immediately preceding the start of TXOP, the STA sends a TVHT_2W or TVHT_W+W mask PPDU.

[0173] h) The STA transmits the TVHT_W mask PPDU on the main TVHT_W channel.

[0174] i) If all un-perforated 20MHz sub-channels (excluding the primary 20MHz channel) are idle during the PIFS period immediately preceding the start of TXOP, then STA transmits an 80MHz HE MU PPDU for the sub-channels that are perforated only in the preamble, which is the secondary 20MHz channel.

[0175] j) If all un-perforated 20MHz subchannels are idle during the PIFS period immediately preceding the start of TXOP, then STA transmits an 80MHz HE MU PPDU of the subchannel that is perforated only in the preamble, which is one of the two 20MHz subchannels located in the secondary 20MHz channel.

[0176] k) If all unperforated 20MHz subchannels are idle during the PIFS period immediately preceding the start of TXOP, the STA transmits a 160 MHz or 80+80MHz HE MU PPDU, where the perforated subchannels in the preamble are 0 to 2 of the 20MHz subchannels of the secondary 20MHz channel and the secondary 80MHz channel.

[0177] If two of the 20MHz sub-channels in the 80MHz secondary channel are punctured, this corresponds to either the next two or the previous two. In the case of a 160MHz preamble, no more than two adjacent 20MHz sub-channels are punctured throughout the entire preamble.

[0178] l) If all unperforated 20MHz subchannels are idle during the PIFS period immediately preceding the start of TXOP, the STA transmits a 160MHz or 80+80MHz HE MU PPDU, wherein the perforated subchannels in the preamble are 0, 1, or 2 20MHz subchannels in the secondary 40MHz channel and 0 to 2 20MHz subchannels in the secondary 80MHz channel.

[0179] At least one 20MHz subchannel is punctured. If two of the 20MHz subchannels of the secondary 80MHz channel are punctured, this corresponds to either the next two or the previous two. For the 160MHz preamble, no more than two adjacent 20MHz subchannels are punctured through the preamble.

[0180] If both the STA and its associated BSS support multi-channel bandwidth, the EDCA TXOP is obtained based solely on the operation of the primary channel. Here, "idle medium" can refer to an idle primary channel. Similarly, "busy medium" can refer to a busy primary channel.

[0181] The CCA is sampled based on the DCF timing relationship, and the slot boundaries can be determined solely through operations on the main channel. Channel idleness during the PIFS period means that whenever the CCA is sampled during the PIFS period that ends at the start of transmission, the CCA for that channel is determined to be idle.

[0182] STAs can update NAVs if they have multiple NAVs. For STAs with two NAV timers, the duration information is indicated via frames as follows: — If the frame has a duration field, the duration information is indicated in the duration field.

[0183] — If the frame is PS polled, the duration information is equal to the time (in microseconds) required to send an ACK frame and an SIFS according to the data rate selection rule.

[0184] A STA that receives at least one frame from a PSDU can update its NAV using information from the valid duration field in the PSDU. The STA does not update its NAV when the RA of a received frame equals the STA's own MAC address. Additionally, if the received frame is a CTS frame and its TA equals the STA's own MAC address, the STA does not update its NAV. For all other received frames, the STA updates its NAV if the received duration is greater than its current NAV value.

[0185] When the STA receives information indicating that the NAV is greater than its current NAV value, it updates the NAV to the new value. This information can be received in the duration field of NDP CTS, NDP ACK, and S1G beacon frames, etc.

[0186] An AP that is not a TXOP holder will use the duration information specified by the RXVECTOR parameter TXOP_DURATION for PPDU to update NAV if all of the following conditions are met, and will not use the duration information specified by the RXVECTOR parameter TXOP_DURATION to update NAV if any of the following conditions are not met.

[0187] — The RXVECTOR parameter TXOP_DURATION is not specified.

[0188] — The AP did not receive frames in which the PPDU included a duration field.

[0189] — The duration indicated by the RXVECTOR parameter TXOP_DURATION is greater than the current NAV value of AP.

[0190] If all of the following conditions are met, the AP holding the TXOP will update the NAV using the duration information indicated by the TXOP_DURATION parameter of the RXVECTOR used for the PPDU; if none of the following conditions are met, the AP will not update the NAV using the duration information indicated by the TXOP_DURATION parameter of the RXVECTOR.

[0191] — The RXVECTOR parameter TXOP_DURATION is not specified.

[0192] — The AP did not receive frames in which the PPDU included a duration field.

[0193] — The duration indicated by the RXVECTOR parameter TXOP_DURATION is greater than the current NAV value of AP.

[0194] — The RXVECTOR parameter BSS_COLOR is different from the BSS color of HE AP.

[0195] Non-AP STAs maintain two NAVs, and APs can maintain two NAVs: an intra-BSS NAV and a basic NAV. The intra-BSS NAV is updated by intra-BSS PPDUs. The basic NAV is updated by inter-BSS PPDUs or by PPDUs that are inter-BSS or cannot be classified as inter-BSS.

[0196] The STA will only update the NAV within the BSS using the duration information indicated by the frame received from the PSDU if all of the following conditions are met: — The frame is identified as a BSS inter-frame.

[0197] — The indicated duration is greater than the current NAV value within the BSS.

[0198] — The RA of the received frame is not the MAC address of the STA. Alternatively, the STA is not the TXOP holder, and the PPDU carrying the frame does not include a frame requesting an immediate response from the STA. Or the STA is not the TXOP holder, and the received frame is a trigger frame.

[0199] The STA will only update the basic NAV using the duration information indicated by the frame received in the PSDU if all of the following conditions are met: — The frame is identified as inter-BSS, or cannot be identified as inter-BSS or inter-BSS.

[0200] — The indicated duration is greater than the current base NAV value.

[0201] — The RA of the received frame is not the MAC address of the STA.

[0202] A STA that is not a TXOP holder will only update its NAV within its BSS using the duration information indicated by the TXOP_DURATION parameter of the RXVECTOR used for the PPDU, provided that all of the following conditions are met: — The RXVECTOR parameter TXOP_DURATION is not specified.

[0203] — The PPDU carrying information about the RXVECTOR parameters is identified within the BSS.

[0204] — The STA did not receive a frame in which the PPDU included a duration field.

[0205] — The duration information indicated by the RXVECTOR parameter TXOP_DURATION is greater than the NAV within the current BSS of the STA.

[0206] The STA updates the base NAV using the duration information indicated by the TXOP_DURATION parameter of the RXVECTOR used for the PPDU only if all of the following conditions are met: — The RXVECTOR parameter TXOP_DURATION is not specified.

[0207] — A PPDU carrying information about the RXVECTOR parameters may be identified as BSS-interval, or may not be identified as either BSS-interval or BSS-interval.

[0208] — The STA did not receive a frame in which the PPDU included a duration field.

[0209] — The duration information indicated by the RXVECTOR parameter TXOP_DURATION is greater than the base NAV of the current STA.

[0210] Figure 9 The diagram illustrates the EDCA parameter set elements applicable to the wireless LAN system of this disclosure.

[0211] In the case of a Business System-on-Site (BSS) infrastructure, EDCA parameter set elements are used to configure policies in the Application Processor (AP) (by changing default MIB attribute values) and to modify policies or adapt to changes in the provided load when a new STA or new service is accepted. The latest EDCA parameter set elements received by the STA are used to update the appropriate Management Information Base (MIB) values.

[0212] refer to Figure 9 (a) The EDCA parameter set element is configured to include an element ID field, a length field, a QoS information field, an update EDCA information field, an AC_BE parameter record field, an AC_BK parameter record field, an AC_VI parameter record field, and an AC_VO parameter record field.

[0213] The element ID field indicates the identifier of the element, and the length field indicates the number of octets within the element excluding the element ID and the length field.

[0214] The QoS Info field includes capability information bits, and the content of this field depends on whether the STA is included in the AP.

[0215] The updated EDCA information fields include an overwrite field indicating whether EDCA parameter set elements overwrite previously stored EDCA parameters, and a PS-polling ACI (Access Class Index) field that informs the STA of the access class used to send PS-polling frames.

[0216] refer to Figure 9(b) The AC_BE parameter record field, AC_BK parameter record field, AC_VI parameter record field and AC_VO parameter record field have the same format, and each field includes the ACI / AIFSN subfield, ECWmin / ECWmax subfield and TXOP limit subfield.

[0217] The ACI / AIFSN fields include: i) the AIFSN (Arbitration Inter-Frame Interval Number) subfield, which indicates the number of time slots after SIFS that the STA postpones before invoking backoff or starting transmission; ii) the ACM (Admission Control Enforcement) subfield, which indicates whether admission control is required for the access class; and iii) the ACI subfield, which indicates the Access Class Index (ACI) value. The ACI subfield refers to the access class referred to by all parameters of this record.

[0218] The ECWmin / ECWmax subfields encode the CWmin and CWmax values ​​in exponential form, respectively. That is, CWmin = 2. ECWmin-1 And CWmax=2 ECWmax-1 .

[0219] The TXOP limit subfield specifies an unsigned integer in fixed units. Through this subfield, the AP declares the TXOP limit, and the TXOP holder must ensure that the TXOP duration does not exceed the TXOP limit while the TXOP period is not zero.

[0220] Figure 10 The diagram illustrates the MUEDCA parameter set elements applicable to the wireless LAN system of this disclosure.

[0221] In the case of a BSS infrastructure, the AP uses MU EDCA parameter set elements to control EDCA usage by non-AP STAs after a specific UL MU TBPPDU transmission. The latest MU EDCA parameter set element received by the non-AP STA is used to update the appropriate MIB value.

[0222] refer to Figure 10 (a) The MUEDCA parameter set element is configured to include an element ID field, a length field, an element ID extension field, a QoS information field, a MUAC_BE parameter record field, a MUAC_BK parameter record field, a MUAC_VI parameter record field, and a MUAC_VO parameter record field.

[0223] The element ID field and the element ID extended field indicate the identifier of the element, and the length field indicates the number of octets in the element excluding the element ID and the length field.

[0224] The QoS information field includes capability information bits, and the content of this field depends on whether the STA is included in the AP.

[0225] refer to Figure 10 (b) The MUAC_BE parameter record field, MUAC_BK parameter record field, MUAC_VI parameter record field and MUAC_VO parameter record field have the same format, and each field includes an ACI / AIFSN subfield, an ECWmin / ECWmax subfield and a MUEDCA timer subfield.

[0226] The descriptions of the ACI / AIFSN and ECWmin / ECWmax subfields are respectively based on... Figure 9 (b) is the same as the description.

[0227] The MU EDCA timer subfield indicates that the STA will use the MU EDCA parameter for the corresponding AC time period.

[0228] Information transmission process used for low-latency service preemption

[0229] 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.

[0230] 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.

[0231] 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).

[0232] Figure 11 This is a diagram illustrating issues related to LLT transmission in DL (downlink) TXOP.

[0233] Specifically, such as Figure 11As illustrated in the diagram, when the AP (i.e., the TXOP holder) acquires the 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 may 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.

[0234] 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.

[0235] Figure 12 This is a diagram illustrating issues related to LLT transmission in UL (uplink) TXOP.

[0236] Specifically, such as Figure 12 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.

[0237] Here, the length of STA 1's TXOP can 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 can 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.

[0238] For reference Figure 11 and Figure 12 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.

[0239] The names of the processes and / or parameters described in this disclosure may be changed, and the STA may include a non-AP STA or an AP STA. Additionally, in the description of this disclosure, RU (Resource Element) may mean RU or M (Multi-)RU. Furthermore, in the description of this disclosure, the statement that a particular STA transmits frames in a particular bandwidth may mean that a particular STA transmits frames through a channel with a particular bandwidth size.

[0240] The methods for sending information to preempt low-latency services are described in detail below.

[0241] Example 1

[0242] Example 1 relates to a process for reporting LLT information.

[0243] exist Figure 11 In this context, the STA can see that the AP must quickly send the LLT to another STA, and the above description can also be applied to the following figures.

[0244] Figure 13 This is a diagram illustrating a method for an AP to send LLT information to a STA 1 according to an embodiment of the present disclosure.

[0245] exist Figure 13 In this context, "LLT TX Requirement" means that an LLT exists / occurs that the AP / STA must quickly send. For example, "LLT TX Requirement" could mean that an LLT has already been entered / occurred in the corresponding STA, or that an LLT exists that must be sent quickly upon request. That is to say, in Figure 13 In this context, "LLT TX requirement for STA 2" can mean that the AP must send an LLT to STA 2.

[0246] 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.

[0247] like Figure 13 As illustrated, STA 1 can send trigger information to the AP, 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) addressed to one or more STAs.

[0248] An AP that receives a PPDU / frame that triggers LLT information can send a frame / PPDU containing LLT information. There may be a predefined time interval (e.g., SIFS, PIFS) between the PPDU / frame that triggers LLT information and the frame containing LLT information.

[0249] STA 1, which receives LLT information from AP, can send an ACK (acknowledgment) allowing AP to send LLTs to other STAs using its TXOP. However, this is only an example, and it is not necessary to send an ACK instructing AP to allow LLTs to be sent to other STAs within a TXOP. Specifically, if the PPDU / frame triggering the transmission of LLT information sent by STA 1 includes the meaning of allowing immediate LLT transmission (after sending the LLT information), then STA 1 may not need to respond with an ACK after receiving the LLT information from AP.

[0250] For example, an ACK can be an ACK frame or a BA (block ACK) frame. Alternatively, an ACK may include at least one of the following information described by a new or existing frame.

[0251] - LLT Tx Enable: Indicates that the STA sending the corresponding information allows LLT transmission to the STA that sent LLT information within its TXOP.

[0252] - LLT TX Duration: Information indicating the length (e.g., X μs) of the LLT transmission duration that the STA sending the corresponding information is allowed to send LLT information within its TXOP.

[0253] The AP sending the LLT information may send the LLT to STA 2 after receiving an ACK from STA 1 or after a predetermined time (e.g., SIFS) following the transmission of the LLT information. Alternatively, the PPDU / frame that includes the LLT sent by the AP may include the PPDU / frame that triggers one or more STAs to send the LLT information.

[0254] Example 1-1

[0255] Example 1-1 relates to one or more types of information included in LLT information sent by an AP / STA. As described above, a STA can be implemented as a non-AP STA or an AP.

[0256] LLT information may include LLT presence information, LLT identification information, delay information, and / or the amount of LLT information.

[0257] For example, the LLT presence information may indicate the presence of an LLT that the STA currently needs to transmit. Additionally or alternatively, the LLT presence information may indicate whether the STA requests / expects to transmit an LLT within the TXOP of a particular STA.

[0258] The LLT presence information may be supported by a field having 1 bit (e.g., the LLT presence information field). For example, when the LLT presence information field value is set to 1 (or 0), this may indicate the presence of an LLT that the STA should currently transmit, or that the STA requests / wants to transmit an LLT within the TXOP of a particular STA. For example, when the LLT presence information field value is set to 0 (or 1) or the field is reserved, this may indicate the absence of an LLT that the STA should currently transmit, or that the STA does not request / want to transmit an LLT within the TXOP of a particular STA.

[0259] 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, then 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, then the field indicating the LLT identification information may be set to 4 bits.

[0260] 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 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, then the LL service corresponding to TID 6 may be classified as <TID 6, LLID 0>.

[0261] Additionally or alternatively, a bitmap may be defined to accommodate 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.

[0262] For example, the delay information may include information about when the LLT should be transmitted.

[0263] 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 can indicate the time in μs.

[0264] Alternatively, the delay information may indicate the point in time when the LLT should be successfully transmitted. For example, the delay information may be based on absolute time, timestamp (TSF) to indicate the point in time when the LLT should be successfully transmitted.

[0265] 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.

[0266] 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.

[0267] 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.

[0268] 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.

[0269] 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.

[0270] 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 used 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 LLT quantity used for AC 1.

[0271] Examples 1-2

[0272] Examples 1-2 relate to a method for indicating / signaling LLT information. Specifically, LLT information can be indicated / signaled via HT control field (Example 1-2-1), BA (block ack) frame (Example 1-2-2), and MAC header (Example 1-2-3).

[0273] Example 1-2-1

[0274] In one embodiment of this disclosure, LLT information can be sent and received via an HT control field (e.g., an A control field). For example, LLT information can be included in a field of a new control type defined as an A control field. This disclosure refers to the control field used for sending and receiving LLT information as an LLT information control field.

[0275] Figure 14 The illustration depicts a method for sending LLT information using an HT control field (e.g., LLT information control with A control) according to an embodiment of the present disclosure. Figure 14 As illustrated, STA 1 can first obtain a TXOP via RTS / CTS switching and then send a PPDU to the AP. In this example, an A (aggregated)-MPDU containing QoS data frames on the PPDU can be sent to the AP.

[0276] The PPDU may include information that triggers the AP to send LLT information. The AP receiving the PPDU may respond to / send an LLT information control field, including LLT information, to the AP using an A-MPDU. The LLT information control field may be included in at least one of the BA frame, the additional QoS data frame, and the QoS empty frame, and may be responded to / sent (to STA 1).

[0277] For example, if the BA frame includes an HT control field, the HT control field (or the BA frame) can be defined as a new control frame type, or the +HTC field value in the MAC header can be set to 1. Therefore, the AP can use the BA frame to simultaneously send LLT information and ACK information for the data frame to STA 1.

[0278] For example, if the ACK policy for the MPDU in the PPDU sent by STA 1 is a policy that requires an immediate response to the BA frame (e.g., implicit BAR), then the BA frame (or BA information) may exist in the A-MPDU sent by the AP. As another example, if the ACK policy for the MPDU in the PPDU sent by STA 1 is a policy that does not require an immediate response to the BA frame (e.g., ACK policy = BA), then the BA frame (or BA information) may not exist in the A-MPDU sent by the AP.

[0279] Alternatively, a STA (e.g., STA 1) that has received LLT information from the AP may send an ACK to the AP in response to the LLT information. Here, the ACK may mean that the STA that has received the LLT information is authorized to perform LLT transmission from the AP or another STA within its TXOP. The ACK sent by the STA may include LLT Tx authorization information and / or LLT Tx duration information, as described above.

[0280] Example 1-2-2

[0281] In one embodiment of this disclosure, it is assumed that LLT information is triggered simultaneously with the transmission of a (QoS) data frame to a specific STA. If the LLT exists on the AP, the AP can send the LLT information (or / and the LLT) along with the BA frame to STA 1 (e.g., the STA that triggered the LLT / LLT information). That is, instead of including the LLT information in another frame, the AP can include the LLT information (or / and the LLT) in the BA frame.

[0282] As an example of this disclosure, Figure 15 This is a diagram used to describe the configuration of BA frames that include LLT information.

[0283] like Figure 15 As illustrated in (a) and (b), LLT information can be set / indicated through reserved fields in the BA control field, regardless of the BA type of the BA frame. As another example, LLT information can be set on bit 10 (B9) (i.e., no reserved memory), bit 11 (B10) (i.e., memory is set on the tag), and bit 12 (B11) (i.e., management ACK) of the BA control field.

[0284] For example, such as Figure 15 As shown in (a), the LLT presence field can be set on the first bit (B0) of the BA control field.

[0285] As another example, such as Figure 15 As illustrated in (b), the LLT Presence field can be set on the first bit (B0) of the BA control field, and LLT identification information can be set on at least one of the sixth bit (B5) to the ninth bit (B10) of the BA control field. In this case, the LLT identification information may include the TID for the LLT currently to be transmitted, and the TID_INFO field may include information about which TID the BA frame is sent to (i.e., information confirming the success or failure of one or more MPDUs for a TID).

[0286] Figure 16 This is a diagram illustrating a process for sending and receiving BA frames including LLT information according to an embodiment of the present disclosure.

[0287] STA 1 can first obtain a TXOP via CTS / RTS switching, and then send a PPDU to the AP. For example, the PPDU may include an A-MPDU containing QoS data frames. In response to the PPDU, the AP can send a BA frame containing LLT information to STA 1.

[0288] The BA frame can include BA information for the ACK of the QoS data frame included in the A-MPDU. Additionally, LLT information can be included in the BA control field of the BA frame. For example, as... Figure 15 As illustrated, LLT information can be included in the BA control field. Therefore, the AP can send ACK information and LLT information for the data frame to STA 1 together with the BA frame.

[0289] Alternatively, STA 1, having already received LLT information from AP, may send an ACK message to AP in response to the LLT information. Here, ACK may mean that the STA that has received the LLT information allows AP or another STA to perform LLT transmission within its TXOP. The ACK sent by the STA may include LLT Tx permission information and / or LLT Tx duration information, as described above. AP, which has sent LLT information to STA 1 or received an ACK for LLT information from STA 1, may send LLT to STA 2.

[0290] In this disclosure, LLT information may be included on the BA frame, regardless of the BA type.

[0291] Alternatively, a new type of BA frame may be defined, or an existing type of BA frame may be used to include LLT information. In this disclosure, a BA frame defined to transmit LLT information is referred to as an LLT BA frame.

[0292] In addition to basic BA frames (e.g., frames that include ACK information for data frames), LLT BA frames may also include LLT information fields. LLT information fields refer to fields containing one or more of the types of LLT information described above.

[0293] An LLT BA frame can satisfy at least one of the conditions described below.

[0294] - The BA type associated with the BA frame (or BA control field) can be defined as a new type.

[0295] The BA type in the BA control field can be a compressed BA frame variant.

[0296] The BA information field of an LLT BA frame can be the same as the BA information field of a compressed BA frame variant.

[0297] - If the BA type of the LLT BA frame is a new type, the LLT information field can exist after the BA information field.

[0298] Alternatively, the LLT information field may utilize the block ACK start sequence control subfield of the BA information field in at least one of the following ways.

[0299] - It can set the segment number subfield of the block ACK start sequence control subfield to a specific value. When the segment number subfield value is set to 4 bits (B3B2B1B0), the segment number subfield value of the block ACK start sequence control subfield can be set to "1111".

[0300] For example, as described above, the LLT information field can be included / placed on the BA frame based on the segment number subfield with a specific value set. For example, the LLT information field can be placed following the segment number subfield with a specific value set. Alternatively, the start sequence control subfield and / or block ACK bitmap subfield may not be present, depending on the segment number subfield with a specific value set.

[0301] Figure 17 This is a diagram illustrating the configuration of an LLT BA frame according to an embodiment of the present disclosure, and the process for sending and receiving LLT BA frames.

[0302] STA 1 can first obtain a TXOP via CTS / RTS switching and then send a PPDU to the AP. For example, the PPDU may include an A-MPDU containing QoS data frames. The PPDU may include information for the AP to trigger LLT information. In response to the PPDU, the AP may send a BA frame containing LLT information (i.e., an LLT BA frame) to STA 1.

[0303] like Figure 17 As illustrated, an LLT BA frame may include ACK information for QoS data frames included in an A-MPDU, and this ACK information may be included in the BA information field. Additionally, a fragment number field may be present, set to a specific value, to indicate the presence of LLT information on the LLT BA frame. In this case, the fragment number field may be positioned after the BA information field including the ACK information, but is not limited to this.

[0304] The fragment number field, set to a specific value, can indicate the presence of LLT information following the fragment number field. Therefore, the AP can use an LLT BA frame to send LLT information along with ACK information for the data frame to STA 1 simultaneously.

[0305] Alternatively, STA 1, having already received LLT information from AP, may send an ACK message to AP in response to the LLT information. Here, ACK may mean that the STA that has received the LLT information allows AP or another STA to perform LLT transmission within its TXOP. The ACK sent by the STA may include LLT Tx permission information and / or LLT Tx duration information, as described above. AP, which has sent LLT information to STA 1 or received an ACK for LLT information from STA 1, may send LLT to STA 2.

[0306] According to this disclosure, it is possible to send a BA frame that includes LLT information, and it is possible to include LLT information in the BA frame that is equal to or greater than the length of the BA information field.

[0307] In one embodiment of this disclosure, the LLT BA frame may satisfy at least one of the conditions described below when it includes information related to multiple TIDs.

[0308] - The BA type in the BA control field can be defined as a new type.

[0309] - The BA type in the BA control field can be a multiSTA BA variant.

[0310] - The BA information field of an LLT BA frame is the same as that of a multi-STA BA frame, but the format of the per-AID TID information subfield of the LLT used for an LLT BA frame can be different.

[0311] Specifically, the AID TID information field of the AID TID information subfield of the LLT BA frame can be applied in at least one of the following ways: - When a non-AP STA and / or AP sends an LLT BA frame, the AID 11 subfield of the AID TID-specific information subfield (for LLT) can be configured as follows. For example, when a non-AP STA sends an LLT BA frame, AID 11 can be set to 0. Furthermore, for example, when the AP sends a PPDU to a single STA, the value of the AID 11 subfield of the AID TID-specific information subfield (for LLT) can be set to 11 LSB of the corresponding STA or AP's AID. When the AP sends a PPDU to two or more non-AP STAs, the value of the AID 11 subfield of the AID TID-specific information subfield (for LLT) can be set to the broadcast address.

[0312] - The ACK type subfield of the AID TID specific information subfield (for LLT) can be set to a specific value (e.g., 0 or 1).

[0313] - (For LLT) The TID subfield of the AID TID specific information subfield can be set to a specific value (e.g., one of 8 to 15), except when the ACK type field value is set to 1 and the TID field value is set to 15.

[0314] - An LLT information field may exist following the AID 11 subfield, ACK type subfield, and TID subfield that meet the above conditions. For example, if an AID TID information field that meets the above conditions exists (e.g., an AID TID information field that includes the AID 11 subfield, ACK type subfield, and TID subfield), then the LLT information field may exist on the AIDTID specific information subfield (used for LLT).

[0315] - Alternatively, if an AID TID information field that satisfies the above conditions exists (e.g., an AID TID information field that includes an AID11 subfield, an ACK type subfield, and a TID subfield), then the block ACK start sequence control field and / or the block ACK bitmap field may not exist on the LLT BA frame.

[0316] Alternatively, if a specific value is set to match the conditions described above for the AID TID information field, the LLT information field may be present or included (on the LLT BA frame) in place of the block ACK start sequence control field and the block ACK bitmap field.

[0317] Figure 18 This is a diagram illustrating the configuration of an LLT BA frame for multiple TIDs and the process for sending and receiving LLT BAs according to an embodiment of the present disclosure.

[0318] The AP can first obtain a TXOP via CTS / RTS switching and then send a PPDU to STA 1. In this example, the PPDU may include a multi-TID A-MPDU, which includes QoS data frames for each of TID 1 and TID 2. The PPDU may include information for triggering the transmission of LLT information through STA 1.

[0319] The AP receiving the corresponding PPDU can respond by sending an LLT BA frame to STA 1 (i.e., a multi-STA BA frame including LLT information or a new type of LLT BA frame). Figure 18 As illustrated in the figure, the corresponding LLT BA frame may include a per AID TID information subfield for ACK information for QoS data frames included in the A-MPDU (i.e., QoS data frames for TID 1 and TID 2).

[0320] Additionally, the AID TID-specific information subfield, which includes LLT information, can use a specific ACK type (e.g., 0) and TID (e.g., 14) value to indicate the presence of LLT information following the AID TID-specific information subfield. Therefore, the AP can use an LLT BA frame to simultaneously send LLT information and ACK information for the data frame to STA 1.

[0321] Alternatively, STA 1, having already received LLT information from AP, may send an ACK message to AP in response to the LLT information. Here, ACK may mean that the STA that has received the LLT information allows AP or another STA to perform LLT transmission within its TXOP. The ACK sent by the STA may include LLT Tx permission information and / or LLT Tx duration information, as described above. AP, which has sent LLT information to STA 1 or received an ACK for LLT information from STA 1, may send LLT to STA 2.

[0322] According to this disclosure, BA frames including LLT information can be transmitted, and the BA frames can include LLT information equal to or longer than the length of the BA information field. Furthermore, BA frames can also be used for multi-TID-based transmissions.

[0323] Example 1-2-3

[0324] In one embodiment of this disclosure, fields in the MAC header can be used to send LLT information.

[0325] As an example of this disclosure, the AP may send a PPDU (e.g., an A-MPDU) to STA 1 that includes additional data fields. These additional data fields may include LLT presence information indicating the presence of LLT information. For example, if a PPDU with an additional data field value set to 1 is sent to the AP, this could mean that LLT information exists to be sent by the AP.

[0326] Alternatively, the STA may send a PPDU (e.g., an A-MPDU) to the AP that includes a QoS control field. When bit 4 of the QoS control field is set to 0 or 1, bit 7 of the QoS control field may indicate the presence or absence of LLT information, and / or the presence of LLT. In this case, bit 7 of the QoS control field may be set to 0 or 1. As described above, when bit 4 of the QoS control field is set to 0 or 1 and bit 7 of the QoS control field is set to indicate the presence or absence of LLT information, the LLT information may be set via at least one of bits 8 to 15 of the QoS control field.

[0327] Figure 19This is a diagram illustrating a method for sending LLT information using a MAC header according to an embodiment of the present disclosure.

[0328] like Figure 19 As illustrated, STA 1 can first obtain a TXOP via RTS / CTS switching and then send a PPDU to the AP. In this example, an A-MPDU containing QoS data frames on the PPDU can be sent to the AP.

[0329] The PPDU may include information that triggers the AP to send LLT information. The AP receiving the PPDU can use the A-MPDU to send additional data fields and / or QoS control fields, including LLT information, to STA 1. In this case, the additional data fields and / or QoS control fields may be included in the BA frame, QoS data frame, or / and QoS empty frame of the A-MPDU.

[0330] As an example of this disclosure, if the BA frame includes a QoS control field, the BA frame can be defined as a new control frame or BA type. Therefore, the AP can use the BA frame to simultaneously send LLT information and ACK information for the data frame to STA 1.

[0331] For example, if the ACK policy is set to require an immediate response to a BA frame (e.g., implicit BAR), the PPDU sent by the AP on the BA frame may include BA information for the MPDU (for QoS data). As another example, if the ACK policy is set to not require an immediate response to a BA frame (e.g., the ACK policy is set to BA), the PPDU sent by the AP on the BA frame may not include BA information for the MPDU (for QoS data).

[0332] Alternatively, STA 1, having already received LLT information from AP, may send an ACK message to AP in response to the LLT information. Here, ACK may mean that the STA that has received the LLT information allows AP or another STA to perform LLT transmission within its TXOP. The ACK sent by the STA may include LLT Tx permission information and / or LLT Tx duration information, as described above. AP, which has sent LLT information to STA 1 or received an ACK for LLT information from STA 1, may send LLT to STA 2.

[0333] In this disclosure, the AP can simultaneously send LLT information to STA 1 along with multiple frames such as BA frames and data frames.

[0334] Example 1-2-4

[0335] In one embodiment of this disclosure, previously defined frames (e.g., CTS frames, CTS-to-self frames, ACK frames) or new types of frames (e.g., LLT Tx request frames, etc.) can be utilized based on predefined frame transmission conditions or conditions indicated in the PPDU / frame that triggers the transmission of LLT information (or / and LLT). The PPDU / frame that triggers the transmission of LLT information (or / and LLT) can satisfy at least one of the following conditions.

[0336] - A PPDU / frame may include LLT information. Alternatively, the PPDU / frame itself may refer to LLT information. For example, when an AP / non-AP STA sends a PPDU / frame, it may mean that there is an LLT that the AP / non-AP STA currently needs to send. Alternatively, when an AP / non-AP STA sends a PPDU / frame, it may mean that the AP / non-AP STA wants to send an LLT to another STA within the TXOP of a particular STA.

[0337] - A PPDU / frame may include information indicating the duration of the PPDU / frame. That is, the information indicating the duration can mean the length of the PPDU / frame that must be satisfied when an LLT Tx request frame is sent. Alternatively, when using an existing frame (e.g., a CTS frame, a CTS-to-self frame, an ACK frame), the information indicating the duration can mean the length of the PPDU / frame included in the existing frame.

[0338] - A PPDU / frame may include information about the bandwidth on which it will be transmitted. For example, if the condition for the PPDU / frame or the condition for triggering the transmission of LLT information (or / and LLT) is dynamic bandwidth, this may mean that the bandwidth is a channel that can be transmitted / used via CCA. As another example, if the condition is 20MHz, then when transmitting the PPDU / frame, either the primary 20MHz channel or the secondary 20MHz channel can be used.

[0339] - A PPDU / frame may include information about the type of PPDU associated with it. For example, if the condition of the PPDU / frame or the condition used to trigger the transmission of LLT information (or / and LLT) is a non-HT PPDU, this may mean that the PPDU / frame should be sent as a non-HT or non-HT repeating PPDU.

[0340] - A PPDU / frame may include information about the data rate / MCS at which the PPDU / frame is sent. For example, if the condition used to trigger the transmission of a PPDU / frame or LLT information (or / and LLT) is 6 Mbps, this may mean that the PPDU / frame should be sent at 6 Mbps.

[0341] Figure 20 This relates to a method for sending and receiving LLT information via existing or new frames, according to an embodiment of the present disclosure.

[0342] like Figure 20 As illustrated, STA 1 can first obtain a TXOP via RTS / CTS switching and then send a PPDU to the AP. In this example, an A-MPDU containing QoS data frames on the PPDU can be sent to the AP.

[0343] The PPDU may include information that triggers the AP to send LLT information. The AP receiving the PPDU can use an LLT Tx request frame to send LLT information to STA 1. For example... Figure 21 As illustrated in the figure, under the conditions of using a non-HT repeating PPDU with a frame / PPDU length of 50µs and a data rate of 6Mbps, a frame / PPDU including an LLT Tx request frame can be sent to STA 1.

[0344] Alternatively, the LLT Tx request frame itself may imply LLT information. For example, when an AP sends a PPDU / frame containing an LLT Tx request frame, it may mean that there is an LLT that the AP currently needs to send, or / and that the AP wants to send an LLT within the TXOP of another STA.

[0345] Alternatively, the LLT TX request frame may be sent to STA 1 while satisfying the above conditions. Alternatively, the LLT TX request frame may be replaced with a previously defined frame (e.g., a CTS frame, a CTS-to-self frame, an ACK frame). If the LLT TX request frame is replaced with a previously defined frame, the frame may still satisfy the above conditions (e.g., the PPDU / frame type is a non-HT repeating PPDU, the transmission rate is 6 Mbps, etc.).

[0346] Alternatively, the transmission conditions of the LLT TX request frame may be included in a PPDU (i.e., a PPDU sent by STA 1 to AP) containing information that triggers STA 1 to send LLT information to AP.

[0347] Alternatively, STA 1, having already received LLT information from AP, may send an ACK message to AP in response to the LLT information. Here, ACK may mean that the STA that has received the LLT information allows AP or another STA to perform LLT transmission within its TXOP. The ACK sent by the STA may include LLT Tx permission information and / or LLT Tx duration information, as described above. AP, which has sent LLT information to STA 1 or received an ACK for LLT information from STA 1, may send LLT to STA 2.

[0348] According to this disclosure, LLT transmission can be requested using a frame based on minimum PPDU / frame conditions.

[0349] Example 2

[0350] 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.

[0351] In this disclosure, a STA (e.g., an AP / non-AP STA, etc.) can acquire / initiate a TXOP by sending a frame / PPDU. Another STA can receive one or more PPDUs from the STA, which include frames that trigger low-latency service (LLT) information within the TXOP. Here, the one or more PPDUs can include frames (e.g., QoS data frames) addressed to one or more STAs.

[0352] 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.

[0353] Alternatively, a STA that has received LLT information from one or more STAs may send an ACK in response to the LLT information. Here, ACK may mean that the STA that has received the LLT information allows the AP or another STA to perform LLT transmission within its TXOP. Alternatively, ACK may include information instructing the STA sending ACK to allow LLT transmission to a STA that has already sent LLT information within its TXOP. Alternatively, ACK may include the LLT transmission allowance time for the STA that has sent LLT information within the TXOP of the STA that sent ACK.

[0354] A STA that has received one or more frames / PPDUs including LLT information can send a frame / PPDU that triggers LLT based on the LLT information to another STA.

[0355] A 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 perform PPDU / frame transmission preparation, which can trigger LLT transmission or prepare for ACK transmission in response to the obtained LLT information.

[0356] The configuration of LLT information and ACK has already been described in Example 1-1, so redundant descriptions will be omitted. The STA that receives the PPDU / frame that triggers LLT can perform frame detection and prepare for LLT transmission through frame detection.

[0357] As an example of this disclosure, within the TXOP set by STA 1, STA 2 can send a frame 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.

[0358] 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.

[0359] Alternatively, the field including LLT information may exist after or on the BA information field of the BA frame. Alternatively, when 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, when 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.

[0360] Alternatively, after the first STA sends an ACK (e.g., an ACK frame) to the second STA (i.e., an ACK frame corresponding to the transmission of LLT information through the second STA), the second STA may send one or more frames containing the LLT to the first STA. For example, the ACK may instruct the first STA, which has already received the LLT information, to allow the AP or another STA to perform LLT transmission within its TXOP.

[0361] Example 3

[0362] Example 3 relates to the LLT information and / or a method for triggering an LLT as described above. As an example of this disclosure, to trigger LLT information and / or an LLT, a trigger frame containing information for sending LLT information can be used.

[0363] Alternatively, it could mean that the LLT information is sent within the trigger frame itself.

[0364] Alternatively, the trigger frame may be a variant of the trigger frame. Variants may be existing variants (e.g., MU-RTS (TXS), BSRP) or newly defined variants. For example, an MU-RTS TXS trigger frame may be used (for LLT information triggering), and a new trigger TXOP sharing mode associated with LLT information transmission may be defined. Therefore, the AP / STA can respond to the trigger frame.

[0365] Alternatively, the trigger frame may use a variant of the basic trigger frame format, but the triggering of the LLT information may be indicated by reserved bits (e.g., reserved bits or EHT reserved bits) in the common information field. For example, when a BSRP trigger frame or a basic trigger frame is sent, the common information field of the trigger frame may contain information indicating that it triggers LLT information. Therefore, the STA may send LLT information in response to the trigger frame instead of a BSR.

[0366] A trigger frame can assign an RU to a specific STA, and can also assign one or more STAs to one or more RAs (Random Access RUs) that can be accessed using UORA (Ultra-ORA based on uplink OFDMA). If the STA receiving the trigger frame wins contention in the assigned RU or in the RA-RU, it can send LLT information.

[0367] Alternatively, the user information field for allocating RU / bandwidth or RA-RU may include information (or bits) indicating its trigger LLT information. This allows the use of an RU to be distinguished by a single trigger frame. For example, the information indicating its trigger LLT information may be indicated by reserved bits in the user information field of the trigger frame. In one example of this disclosure, the trigger frame may be a management frame (e.g., an action frame).

[0368] Alternatively, the trigger frame may additionally include the information / conditions for sending LLT information as described below: - Frame Type: This refers to the type of frame from which LLT information will be sent. In other words, frame type information can include information about in which frame the LLT information should be sent. For example, frame type information can be sent via LLT Tx request frames and other frames described in the LLT information transmission method (e.g., CTS, CTS-to-self, Ack frames).

[0369] - PPDU / Frame Duration (e.g., Xμs): This indicates the length of the PPDU / frame through which LLT information is transmitted. For example, PPDU / Frame Duration information can indicate the length of the frame / PPDU that must be satisfied when an LLT Tx request frame is transmitted.

[0370] Alternatively, when using existing frames (e.g., CTS, CTS-to-self, Ack frames, etc.), PPDU / frame segmentation information can be indicated by PPDU / length information included in the existing frame.

[0371] - Bandwidth: This indicates the bandwidth of the PPDU / frame transmitted using LLT information. For example, if the condition is dynamic bandwidth, the bandwidth information can indicate the transmittable / available channel via CCA when transmitting a frame. As another example, if the bandwidth condition is 20MHz, then a 20MHz channel can be used between the primary 20MHz channel and the secondary channel when transmitting a frame.

[0372] - PPDU Type: This can refer to the type of PPDU / frame to which the LLT information must be sent. For example, if the condition associated with the PPDU type is non-HT PPDU, this may mean that the corresponding PPDU / frame is a non-HT or non-HT repeated PPDU.

[0373] - Data Rate / MCS: This can refer to the data rate / MCS that must be sent for the PPDU / frame containing LLT information. For example, if the condition regarding the data rate is 6 Mbps, this might mean that frames must be sent at 6 Mbps.

[0374] Figure 21 This is a diagram illustrating a method for triggering LLT transmission using a trigger frame according to an embodiment of the present disclosure.

[0375] As an example of this disclosure, STA 1 can first obtain a TXOP via RTS / CTS switching and then send a PPDU to the AP. Here, the PPDU may include an A-MPDU containing a QoS data frame and a trigger frame. Alternatively, the A-MPDU may contain only the trigger frame.

[0376] exist Figure 21In this configuration, the ACK policy for one or more QoS data frames sent with the trigger frame can be set to block ACK or no ACK. In this case, the AP may not send a BA as an immediate response. Alternatively, if the A-MPDU includes one or more QoS data frames and a trigger frame that triggers the transmission of LLT information, the BA for the QoS data frames can be defined as an ACK policy that allows a later response (hereinafter referred to as the LLT ACK policy).

[0377] Alternatively, the A-PPDU containing the MPDU with the LLT ACK policy may be included in a later version of the UHR PPDU or PPDU. Alternatively, the ACK information for a BA to be responded to later may include a BA in response to a BAR (Block ACK Request) frame or a BA for a QoS data frame to be sent later.

[0378] In response to a trigger frame, the AP can send an LLT Tx request frame containing LLT information. Alternatively, the LLT Tx request frame itself can imply LLT information. For example, if the AP sends a corresponding PPDU / frame (e.g., an LLT Tx request frame), this might mean that the AP currently has an LLT to send. Additionally, the LLT Tx request frame can be interpreted as a request from the AP to send an LLT in the STA's TXOP.

[0379] Alternatively, alternative locations may be selected, such as... Figure 20 The conditions in the LLT Tx request frame can be predetermined, and when the conditions are met, the LLT Tx request frame can be sent without triggering LLT information. Alternatively, the LLT Tx request frame can be replaced with an existing frame (e.g., CTS, CTS-to-Self, ACK frame, etc.). For example, if the LLT Tx request frame is replaced with an existing frame, the existing frame can also satisfy conditions such as non-HT repeating PPDU, 6 Mbps, etc.

[0380] An AP that has already sent an LLT Tx request frame can send an LLT to a target STA (e.g., STA 2). Alternatively, a STA that has already received an LLT message from the AP can send an ACK in response to that LLT message. For example, an ACK can instruct the STA that has received the LLT message to allow the AP or another STA to send an LLT in the TXOP. Here, the ACK can be... Figure 13 An AP that has sent an LLT message or received an ACK for an LLT message from STA 1 can send an LLT to STA 2.

[0381] In this disclosure, the trigger frame can be sent using an A-MPDU, depending on the circumstances, to include QoS data frames and ACK policies, etc.

[0382] Figure 22 This is a diagram illustrating a method for triggering LLT transmission using a trigger frame according to an embodiment of the present disclosure.

[0383] As an example of this disclosure, STA 1 can first obtain a TXOP via RTS / CTS switching and then send a PPDU to the AP. Here, the PPDU may include an A-MPDU containing a QoS data frame and a trigger frame. Alternatively, the A-MPDU may contain only the trigger frame.

[0384] exist Figure 22 In this configuration, the ACK policy for the sent trigger frame and one or more QoS data frames can be set to implicit BAR ACK. In this case, the A-MPDU sent by the AP may include BA (i.e., immediate response) and an LLT Tx request frame as a response to the trigger frame.

[0385] In response to a trigger frame, the AP may send an LLT Tx request frame that includes LLT information. Alternatively, the LLT Tx request frame itself may imply LLT information. For example, if the AP sends a corresponding PPDU / frame (e.g., an LLT Tx request frame), this may imply that the AP currently has an LLT to send. Additionally, the LLT Tx request frame can be interpreted as a request from the AP to send an LLT in the STA's TXOP.

[0386] Alternatively, alternative locations may be selected, such as... Figure 20 The conditions in the LLT Tx request frame can be predetermined, and when the conditions are met, the LLT Tx request frame can be sent without triggering LLT information. Alternatively, the LLT Tx request frame can be replaced with an existing frame (e.g., CTS, CTS-to-Self, ACK frame, etc.). For example, if the LLT Tx request frame is replaced with an existing frame, the existing frame can also satisfy conditions such as non-HT repeating PPDU, 6 Mbps, etc.

[0387] An AP sending an LLT Tx request frame can send an LLT to a target STA (e.g., STA 2). Alternatively, a STA receiving the LLT information from the AP can send an ACK in response to the LLT information. For example, an ACK can instruct the STA that received the LLT information to allow the AP or another STA to send the LLT in the TXOP. Here, the ACK can be... Figure 13 An AP that sends an LLT message from STA 1 or receives an ACK for an LLT message can send an LLT to STA 2.

[0388] That is, in this disclosure, the response to the trigger frame can be sent simultaneously using A-MPDU and BA.

[0389] Additionally, the aforementioned trigger frame can trigger a Tx request frame to send LLT information. Here, in Figure 13 There may be situations where the AP (i.e., the TXOP responder) needs to quickly send an LLT to STA 1 for STA 1 (i.e., the TXOP holder). Trigger frames can also be used in these situations. For example, a trigger frame may include information about the LLT triggering mode (i.e., information indicating the mode associated with the frame / message to be triggered).

[0390] For example, information about the LLT trigger mode can indicate one of the following: triggering as Figure 20 and Figure 12 The modes shown include frames containing LLT information (e.g., LLT Tx request frames); transmissions with LLT enabled (e.g., QoS data frames) (e.g., to TXOP holders); or modes that allow both of the above.

[0391] Alternatively, a STA that receives a trigger frame that does not have an LLT trigger mode can decide whether to send LLT information, send LLT, or send both LLT information and LLT.

[0392] Figure 23 This is a diagram illustrating a method for triggering an LLT to a TXOP responder according to an embodiment of the present disclosure.

[0393] Figure 23 The illustration shows an example of using a trigger frame to trigger an LLT transmission. In one example of this disclosure, STA 1 can first obtain a TXOP via RTS / CTS switching and then send a PPDU to the AP. Here, the PPDU may include an A-MPDU containing a QoS data frame and a trigger frame. Alternatively, the A-MPDU may consist of only the trigger frame.

[0394] exist Figure 23 In this context, the ACK policy for the sent trigger frame and one or more QoS data frames can be set to implicit BAR ACK. In this case, the A-MPDU sent by the AP may include BA (i.e., immediate response) and LLT as a response to the trigger frame.

[0395] Alternatively, the trigger frame may include the aforementioned mode information for implementing LLT transmission. Alternatively, an LLT may not exist for STA 1. Alternatively, the STA receiving a trigger frame without LLT trigger mode information may decide whether to send LLT information or LLT, or both. For example, in Figure 23 Instead of LLT, a frame containing LLT information for another STA (e.g., an LLTTx request) can be sent.

[0396] Example 4

[0397] Example 4 relates to the process and related parameters for triggering LLT information. That is, as described in the examples, LLT information may be indicated by one or more frames, and therefore may require a process for triggering LLT information. LLT information triggering may be performed via the HT control field (Example 4-1) and / or the PHY preamble / header (Example 4-2).

[0398] Example 4-1

[0399] In one embodiment of this disclosure, the triggering of LLT information (or / and LLT) can be performed via an HT control field. That is, the information for sending LLT information (or / and LLT) can be included in an HT control field (e.g., an A control field), and a new control field can be configured for the LLT information (or / and LLT) that is a control type of the A control field.

[0400] The control field may include information about one or more conditions used to send LLT information (or / and LLT). The one or more conditions used to send LLT information (or / and LLT) may include conditions related to LLT Tx polling, frame type, PPDU / frame duration (e.g., X μs), bandwidth, PPDU type, and data rate / MCS, respectively.

[0401] LLT Tx polling information / conditions can indicate whether to trigger / request LLT information (or / and LLT) transmission. For example, LLT Tx polling information / conditions can consist of a 1-bit field. If the value of the field is set to 0 (or 1), this may mean triggering / requesting LLT information (or / and LLT) transmission. Alternatively, if the information indicating whether to trigger / request LLT information (or / and LLT) transmission is included in a control field, the control field can be interpreted as indicating LLT Tx polling.

[0402] Information / conditions related to the frame type may include information / conditions regarding which frame the LLT information (or / and LLT) should be sent in. For example, as mentioned above, LLT information (or / and LLT) can be sent and received via LLT Tx request frames, CTS frames, CTS-to-Self frames, or ACK frames.

[0403] Information / conditions related to the duration of a PPDU / frame may include information / conditions indicating the length of the PPDU / frame that includes LLT information (or / and LLT). That is, information indicating the duration may refer to the length of the PPDU / frame that must be satisfied when an LLTTx request frame is sent. Alternatively, when using legacy frames (e.g., CTS frames, CTS-to-self frames, ACK frames), information indicating the duration may refer to the length of the PPDU / frame included in the legacy frame.

[0404] Bandwidth-related information / conditions may include information about the bandwidth through which PPDU / frames containing LLT information (or / and LLT) will be transmitted. For example, if the condition for the PPDU / frame, or the condition used to trigger the transmission of LLT information (or / and LLT), is dynamic bandwidth, this may mean that the bandwidth is a channel that can be transmitted / available via CCA. As another example, if the condition is 20MHz, then when transmitting the PPDU / frame, either the primary 20MHz channel or the secondary channel within the 20MHz channel can be utilized.

[0405] Information / conditions related to the PPDU type may include information / conditions regarding the type of PPDU / frame that must be sent containing LLT information (or / and LLT). For example, if the condition for the PPDU / frame or the condition used to trigger the transmission of LLT information (or / and LLT) is a non-HT PPDU, this may mean that the PPDU / frame must be sent as a non-HT or non-HT repeating PPDU.

[0406] When sending a PPDU / frame containing LLT information (or / and LLT), the information / conditions related to the data rate / MCS may include information / conditions about the data rate / MCS. For example, if the condition of the PPDU / frame or the condition used to trigger the transmission of LLT information (or / and LLT) is 6 Mbps, this may mean that the PPDU / frame should be sent at 6 Mbps.

[0407] Figure 24 This is a diagram illustrating a method for triggering LLT information transmission using a control field according to an embodiment of the present disclosure.

[0408] STA 1 can first obtain a TXOP via RTS / CTS frame switching, and then send a PPDU to the AP. Here, the PPDU may include an A-MPDU, which contains QoS data frames. Additionally, the information that triggers the AP to send LLT information can be included in the HT control field (e.g., the A control field) of the PPDU.

[0409] exist Figure 24 In this context, the PPDU can include various types of information / conditions (e.g., PPDU / frame duration, bandwidth, PPDU type, data rate, MCS, etc.) for the transmission of LLT information (or / and LLT). For example, the PPDU / frame duration could be 50µs, the bandwidth could be dynamically set (i.e., set to available bandwidth via CCA), the PPDU type could be a non-HT copied PPDU, and the data rate could be 6Mbps. Therefore, LLT Tx request frames can be sent and received based on various types of information / conditions.

[0410] Alternatively, the LLT Tx request frame itself may imply LLT information. For example, when an AP sends an LLT Tx request frame, it may mean that there is an LLT that the AP currently needs to send, or / and that the AP wants to send an LLT within the TXOP of a specific STA (e.g., STA 1).

[0411] Alternatively, the LLT Tx request frame may not include information that triggers the LLT information. In this case, the AP can send a frame that meets the following conditions: Figure 24 The conditions in the LLT information (or / and LLT) (i.e., the various types of conditions used to send LLT information (or and LLT)).

[0412] Alternatively, the LLT Tx request frame may be replaced with an existing frame (e.g., a CTS frame, a CTS-to-Self frame, an ACK frame, etc.). For example, if the LLT Tx request frame is replaced with an existing frame, the existing frame may still satisfy various types of conditions for the transmission of the aforementioned LLT information (or / and LLT).

[0413] Alternatively, STA 1, having already received LLT information from AP, may send an ACK message to AP in response to the LLT information. Here, ACK may mean that the STA that has received the LLT information allows AP or another STA to perform LLT transmission within its TXOP. The ACK sent by the STA may include LLT Tx permission information and / or LLT Tx duration information, as described above. AP, which has sent LLT information to STA 1 or received an ACK for LLT information from STA 1, may send LLT to STA 2.

[0414] This disclosure enables the request for the transmission of LLT information after appropriately setting the conditions associated with the HT control field.

[0415] Example 4-2

[0416] In one embodiment of this disclosure, the triggering of LLT information (or / and LLT) can be performed via a PHY preamble / header. In this case, the PHY preamble / header may refer to the PHY preamble / header of the PPDU used to trigger the transmission of LLT information (or / and LLT). For example, the PHY preamble / header may include one or more messages for sending LLT information (or / and LLT).

[0417] As an example of this disclosure, fields that trigger LLT message (or / and LLT) transmissions (e.g., fields indicating whether LLT message / LLT transmissions are required) may be included in the PHY header. That is, whether LLT telegram transmissions are permitted can be indicated by this field.

[0418] Alternatively, one or more conditions / information described in Example 4-1 for sending LLT information (or / and LLT) may be included in a PPDU (e.g., the PHY header / preamble of the PPDU), which includes / does not include information that triggers the LLT information (or / and LLT).

[0419] Alternatively, a PHY header / preamble containing fields that trigger LLT information (or / and LLT) transmission may be included in the PPDU / frame sent to the AP, and the response to the PPDU / frame may be an existing frame (e.g., a CTS frame, a CTS-to-Self frame, an ACK frame, etc.) or a new type of frame (e.g., an LLT Tx request frame).

[0420] Figure 25 This is a diagram illustrating a method for triggering LLT information transmission using a PHY header according to an embodiment of the present disclosure.

[0421] STA 1 can first obtain the TXOP via RTS / CTS frame switching and then send a PPDU to the AP. Here, the PPDU may include an A-MPDU, which contains a QoS data frame. Additionally, information triggering the AP's LLT information (or / and LLT) transmission can be included in the PPDU's PHY preamble / header. Specifically, the PHY header may include fields indicating whether LLT information (or / and LLT) transmission is required (e.g., LLT information Tx field, etc.).

[0422] exist Figure 25In this context, the PPDU can include various types of information / conditions (e.g., PPDU / frame duration, bandwidth, PPDU type, data rate, MCS, etc.) for transmitting LLT information (or / and LLT). For example, the PPDU / frame duration could be 50µs, the bandwidth could be dynamically set (i.e., set to available bandwidth via CCA), the PPDU type could be a non-HT copied PPDU, and the data rate could be 6Mbps. Therefore, LLT Tx request frames can be sent and received based on various types of information / conditions.

[0423] Alternatively, the LLT Tx request frame itself may imply LLT information. For example, when an AP sends an LLT Tx request frame, it may mean that there is an LLT that the AP currently needs to send, or / and that the AP wants to send an LLT within the TXOP of a specific STA (e.g., STA 1).

[0424] Alternatively, the LLT Tx request frame may not include information that triggered the LLT. In this case, the AP can send a frame that meets the requirements as shown in the image. Figure 25 The conditions in the LLT information (or / and LLT) (i.e., the various types of conditions used to send LLT information (or and LLT)).

[0425] Alternatively, the LLT Tx request frame may be replaced with an existing frame (e.g., a CTS frame, a CTS-to-Self frame, an ACK frame, etc.). For example, if the LLT Tx request frame is replaced with an existing frame, the existing frame may still satisfy various types of conditions for transmitting the aforementioned LLT information (or / and LLT).

[0426] Alternatively, the transmission conditions for the LLT Tx request frame may be included in the PPDU that triggers the AP to send LLT information (or / and LLT).

[0427] Alternatively, STA 1, having already received LLT information from AP, may send an ACK message to AP in response to the LLT information. Here, ACK may mean that the STA that has received the LLT information allows AP or another STA to perform LLT transmission within its TXOP. The ACK sent by the STA may include LLT Tx permission information and / or LLT Tx duration information, as described above. AP, which has sent LLT information to STA 1 or received an ACK for LLT information from STA 1, may send LLT to STA 2.

[0428] The examples described above in this disclosure enable the sending and receiving of LLT information (or / and LLT) with minimal overhead.

[0429] Example 4-3

[0430] In one embodiment of this disclosure, in addition to the method for triggering the transmission of LLT information described in Embodiments 4-1 and 4-2, a method for triggering LLT transmission may be applied.

[0431] For example, there might be a situation where the AP (i.e., the TXOP responder) needs to quickly send an LLT to STA 1 (i.e., the TXOP holder). In other words, a method that directly triggers the LLT transmission to the TXOP responder can be applied.

[0432] As an example of this disclosure, STA 1 (e.g., TXOP holder) is able to send information to another STA (e.g., TXOP responder) related to whether a transmission of a certain frame / information (i.e., LLT trigger mode information) is triggered.

[0433] For example, the LLT triggering mode can be divided into a first mode that triggers frames that include LLT information (e.g., LLT Tx request frames), a second mode that enables LLT transmission (e.g., QoS data frames), and a third mode that allows both the first and second modes.

[0434] Alternatively, the trigger frame can be defined as the frame itself that allows the transmission of LLTs (e.g., QoS data frames) without an LLT trigger mode.

[0435] Alternatively, the STA receiving the trigger frame without setting the LLT trigger mode can determine the LLT information or at least one of the LLTs to be sent by the STA.

[0436] Figure 26 This is a diagram illustrating a method for triggering an LLT to a TXOP responder according to an embodiment of the present disclosure.

[0437] STA 1 can first obtain a TXOP via RTS / CTS frame switching, and then send a PPDU to the AP. Here, the PPDU can include a QoS data frame, a QoS empty frame, and an A-MPDU, which includes a control field for LLT transmission in each frame. At this time, the AP can perform an immediate response operation to the QoS data frame by including a BA frame in the A-MPDU, and simultaneously perform a response operation to the control field (i.e., LLT transmission operation).

[0438] Alternatively, the control field may include information about the LLT triggering mode that enables LLT transmission. Alternatively, one or more conditions / information for LLT transmission described in Embodiment 4-1 may be included in the PPDU. Alternatively, the LLT for STA 1 may not exist. Alternatively, the STA (e.g., AP) receiving the control field in the absence of an LLT triggering mode can determine which data the STA will transmit within the LLT and / or LLT information. For example, in Figure 26 In this context, the AP may send frames that include LLT information for another STA (e.g., STA2) instead of LLT (e.g., LLT Tx request frames).

[0439] Figure 27 This is a diagram illustrating a method for triggering LLT to a TXOP responder according to an embodiment of the present disclosure. That is, Figure 27 This relates to a method for triggering LLT transmission using a PHY header / preamble.

[0440] STA 1 can first obtain the TXOP via RTS / CTS frame switching, and then send the PPDU to the AP. Here, the PPDU can include a QoS data frame, a QoS empty frame, and a PHY header / preamble for LLT transmission in each frame. At this time, the AP can perform an immediate response operation on the QoS data frame including the BA frame, and simultaneously perform a response operation on the PHY header / preamble (i.e., LLT transmission operation).

[0441] Alternatively, the PHY header / preamble may include information about the LLT triggering mode that enables LLT transmission. Alternatively, one or more conditions / information for LLT transmission described in Examples 4-2 may be included in the PPDU. Alternatively, the LLT for STA 1 may not exist. Alternatively, a STA (e.g., AP) receiving the PHY header / preamble without an LLT triggering mode can determine which data the STA will transmit in the LLT and / or LLT information. For example, in Figure 26 In this context, the AP may send frames that include LLT information for another STA (e.g., STA2) instead of LLT (e.g., LLT Tx request frames).

[0442] According to the above embodiments, the AP can receive one or more PPDUs / frames from the STA that trigger the transmission of LLT information (or / and LLT), and can send and receive information for sending LLT information (or / and LLT) via the HT control field (e.g., the A control field) or the PHY preamble / header.

[0443] As described above, the HT control field may include information for LLT information / LLT transmission (e.g., LLT Tx polling information, frame type, PPDU / frame duration (e.g., X μs), bandwidth, PPDU type, data rate / MCS, and / or at least one of LLT trigger mode). Each type of information for LLT information / LLT transmission has already been described above, so redundant descriptions will be omitted.

[0444] Here, the LLT trigger mode can be defined as a first mode that triggers a frame containing LLT information / LLT (e.g., an LLT Tx request frame), a second mode that enables LLT transmission (e.g., a QoS data frame), and a third mode that allows both the first and second modes. Alternatively, in the absence of an LLT trigger mode, the STA receiving the control field can determine which data the STA will transmit in the LLT and / or LLT information.

[0445] In another example of this disclosure, when one or more PPDUs / frames that trigger LLT information (or / and LLT) transmission are included in the PHY header / preamble, the field that triggers LLT information (or / and LLT) transmission may be included in the PHY header / preamble. Alternatively or additionally, the PHY header / preamble may include information about the LLT triggering mode used to transmit the LLT. For example, the LLT information Tx field and the field indicating the LLT triggering mode may be separated / combined. When the LLT information Tx field and the field indicating the LLT triggering mode are separated, each of the LLT information Tx field and the field indicating the LLT triggering mode may indicate whether LLT information transmission is required and whether LLT transmission is required.

[0446] Through the above embodiments, the TXOP holder can confirm LLT-related information by receiving LLT information from one or more STAs. Furthermore, through information exchange between the TXOP holder and the STA requiring LLT transmission, LLTs can be sent efficiently as needed.

[0447] Meanwhile, in the various embodiments described above, a first device (e.g., a non-AP STA or AP STA) provides one or more second devices (e.g., AP STA or non-AP STA) with the opportunity to transmit (e.g., transmit low-latency service (LLT)) within a TXOP it has already acquired. Here, the first device providing the TXOP may be referred to as the TXOP holder, and the one or more second devices receiving the TXOP may be referred to as the TXOP responder or a device that is not a TXOP holder.

[0448] Therefore, the first device, as the TXOP holder, has a reduced chance of transmitting its own data within the TXOP it has already acquired, and one or more devices that have received the TXOP from the TXOP holder can gain further advantages by transmitting LLTs, thus acquiring the TXOPs themselves without having to go through potentially time-consuming channel access. Therefore, post-management of the TXOP holder and TXOP responders may be required after the process including triggering the LLT message (LLTI), transmitting the LLTI, and transmitting the LLT (e.g., a preemption process). For this purpose, at least one rule can be applied as follows: 1) TXOP holder perspective: TXOP holder refers to the device that triggers the sending of LLT information and / or LLTs by allowing one or more STAs (including TXOP responders).

[0449] 1-1) A device acting as a TXOP holder provides one or more TXOP responders with the TXOP it has acquired, and after the TXOP, it is able to access the channel with a priority exceeding that of the TXOP responders. For this purpose, for example, an EDCA parameter set with high priority (HP) can be defined. In this disclosure, this is referred to as the HP EDCA parameter set.

[0450] Here, the HP EDCA parameter set refers to parameters configured to allow channel access to be faster (with priority) than the general (i.e., non-priority set) EDCA parameters. For example, it can be set to a lower AIFSN than the existing AIFSN (i.e., the number of slots after the SIFS delay before the STA invokes backoff or begins transmission), and a lower CWmax than the existing CWmax (i.e., the CW parameter is given an initial value of CWmin, can take twice the value in the event of transmission failure, and when the CW parameter value becomes CWmax, it attempts to transmit data while maintaining the CWmax value until the data transmission is successful).

[0451] Alternatively, the HP EDCA parameter can be used after the process of triggering the LLT message in the TXOP and sending the LLTI (LLT message) and LLT (i.e., the time of TXOP termination provided from the TXOP holder to the TXOP responder).

[0452] Alternatively, the HP EDCA parameter set can be declared by the AP. For example, it can be declared by being included in beacon, probe response frames, etc.

[0453] Alternatively, the HP EDCA parameter set may include a timer (e.g., X μs). This timer indicates the period during which the HP EDCA parameter set is used. That is, when the timer expires, the HP EDCA parameter set can no longer be used, and the existing (i.e., unprioritized) EDCA parameter set is used. Here, the timer may start from the time when the TXOP provided by the TXOP holder to the TXOP responder terminates.

[0454] Alternatively, the existing EDCA parameter set IE (see [link to EDCA parameter set]) may be used. Figure 9 ) or MU EDCA parameter set IE (see Figure 10 The format of ) can be used as the format of the HP EDCA parameter set, and these values ​​can be set differently.

[0455] 2) From the perspective of STAs other than TXOP holders (i.e., TXOP responders): TXOP responders refer to STAs that have received a trigger for LLT information and / or LLT transmission, or STAs that have sent LLT information and / or LLT.

[0456] 2-1) A device acting as a TXOP responder receives a TXOP from a TXOP holder and is subsequently able to access the channel with a lower priority than the TXOP holder. For this purpose, for example, an EDCA parameter set with low TXOP priority (LP: low priority) can be defined. In this disclosure, this is referred to as the LP EDCA parameter set.

[0457] Here, the LP EDCA parameter set refers to parameters configured to allow channel access later (lower priority) than standard (i.e., unpriorized) EDCA parameters. For example, they can be configured to have a higher AIFSN, a higher CWmax, etc. than the standard.

[0458] Alternatively, the LP EDCA parameter can be used after the process of triggering the LLT message in the TXOP and sending the LLTI (LLT message) and LLT (i.e., starting from the time of TXOP termination provided by the TXOP holder to the TXOP responder).

[0459] Alternatively, the LP EDCA parameter set can be declared by the AP. For example, it can be declared by being included in beacon, probe response frames, etc.

[0460] Alternatively, the LP EDCA parameter set may include a timer (e.g., X μs). This timer indicates the period during which the LP EDCA parameter set is used. That is, when the timer expires, the LP EDCA parameter set can no longer be used, and the existing (i.e., no-priority) EDCA parameter set is used. Here, the timer may start from the time when the TXOP terminates, provided by the TXOP holder to the TXOP responder.

[0461] Alternatively, the existing EDCA parameter set IE (see [link to EDCA parameter set]) may be used. Figure 9 ) or MUEDCA parameter set IE (see Figure 10 The format of ) can be used as the format of the LP EDCA parameter set, and these values ​​can be set differently.

[0462] Alternatively, the LP EDCA parameter set may correspond to the MU EDCA parameter set.

[0463] Figure 28 This is a diagram illustrating a channel access method according to an embodiment of the present disclosure.

[0464] Figure 28 The diagram illustrates the post-management method for situations where a non-AP STA provides a UL TXOP to an AP.

[0465] refer to Figure 28 STA 1 triggers the sending of LLT information to AP, AP provides LLT information to STA 1 (if an LLT to be sent exists), and AP is able to send LLT to STA 2.

[0466] Alternatively, the operations described in the various embodiments above can be performed within the TXOP provided by STA 1 to AP.

[0467] Furthermore, the operations described in the various embodiments above are not limited to being performed within the TXOP provided by STA 1 to AP. That is, the channel access operations described above can be applied even when methods / operations for triggering LLT information and sending LLT information and / or LLT using other methods are performed within the TXOP.

[0468] exist Figure 28 In the case where the TXOP terminates, the AP can perform channel access by applying the LP EDCA parameter after the TXOP, because it has already used STA 1's TXOP to send the LLT. On the other hand, because STA 1 has provided the AP with a TXOP for the AP to use to send the LLT, the AP can perform channel access by applying the HP EDCA parameter after the TXOP.

[0469] Figure 29 This is a diagram illustrating a channel access method according to an embodiment of the present disclosure.

[0470] Figure 29 The diagram illustrates the post-management method for scenarios where the AP provides DL TXOP to the STA.

[0471] refer to Figure 29 The AP triggers one or more STAs to send LLT information, and the one or more STAs that receive this (only those STAs that have the LLT to send) provide the LLT information to the AP, and the AP receives the LLT from the STA by triggering the LLT transmission.

[0472] Alternatively, the operations described in the various embodiments above may be performed within a TXOP provided by the AP to one or more STAs.

[0473] Furthermore, or alternatively, the operations performed within a TXOP provided by the AP to one or more STAs are not limited to those described in the various embodiments above. That is, the channel access operations described above can be applied even when methods / operations for triggering LLT information and sending LLT information and / or LLT are performed within the TXOP.

[0474] exist Figure 29 In the case where TXOP terminates, STA 1 and STA 2 can perform channel access by applying the LPEDCA parameter after TXOP because they have already transmitted LLT using the AP's TXOP. On the other hand, because the AP has already provided the STAs with a TXOP for use in transmitting LLT, they can perform channel access by applying the HP EDCA parameter after TXOP.

[0475] Figure 30 This is a diagram illustrating a method for sending and receiving data according to an embodiment of the present disclosure.

[0476] exist Figure 30 In this context, the first device refers to the device that is the TXOP holder (e.g., an AP device or a non-AP STA device), and the second device refers to the device that is the TXOP responder (e.g., a non-AP STA device or an AP device).

[0477] Figure 30 The diagram illustrates the operation of the first device as the TXOP holder, based on the previously proposed method. Figure 30 The examples in this document are for illustrative purposes only and are not intended to limit the scope of this disclosure. Depending on the situation and / or configuration, they may be omitted. Figure 30 Some steps are shown in the diagram.

[0478] refer to Figure 30 The first device sends a PPDU to the second device to allow data transmission of the second device within the TXOP obtained by the first device (S3001).

[0479] Here, data transmission from the second device can refer to Low Latency Service (LLT) transmission.

[0480] Here, a PPDU used to allow data transmission of the second device may mean a PPDU / frame that transmits LLT information indicating that the second device needs data transmission and / or triggers LLT transmission.

[0481] Here, as described above, the operations described in the various embodiments can be performed within the TXOP provided by the first device to the second device.

[0482] The first device performs channel access (S3002) after TXOP has been terminated.

[0483] Here, channel access via the first device can be performed with a higher priority than channel access via other devices, including the second device, based on the PPDU, to ensure that data transmission via the second device has been successfully sent to the second device. In other words, when the first device recognizes that a PPDU allowing data transmission via the second device has been successfully sent to the second device, channel access via the first device can be performed with a higher priority than channel access via other devices, including the second device. For example, the first device can recognize that the PPDU has been successfully sent to the second device by receiving an acknowledgment from the second device that the PPDU has been successfully sent. If the second device fails to receive the PPDU or the first device does not recognize that the PPDU has been successfully received by the second device, then TXOP cannot be shared / provided, and the first device needs to share / provide TXOP to perform channel access with a higher priority.

[0484] For example, channel access via the first device can be performed based on the HP EDCA parameter set. Compared to an EDCA parameter set without priority, the HP EDCA parameter set can be set to a lower AIFSN value and / or a lower CW maximum value (CWmax).

[0485] Additionally, for example, the HP EDCA parameter set can include a timer, and the HP EDCA parameter set can be available after the TXOP has terminated until the timer expires.

[0486] Additionally, the HP EDCA parameter set can be declared by the AP in a beacon frame or probe response frame.

[0487] In step S3001, the PPDU can be configured to include a legacy portion, a SIG portion (e.g., U-SIG, UHR-SIG, etc.), an STF portion (e.g., UHR-STF), an LTF portion (e.g., UHR-LTF), and a data portion.

[0488] Any part (i.e., field) can be divided into multiple subparts / subfields, in whole or in part. Each field (and its subfields) can be divided into 4µs. The signal is transmitted in units of N (where N is an integer). Additionally, a guard interval (GI) may be included. The common subcarrier frequency spacing value (delta_f = 312.5kHz / N or 312.5kHz) can be used. N (where N is an integer) can be applied to the entire field, or the first delta_f can be applied to the first part (e.g., the entire legacy part, all / part of the SIG part), and the second delta_f (e.g., a value less than the first delta_f) can be applied to all / part of the remaining part.

[0489] Some of the fields mentioned above can be omitted, and the order of the fields can be changed in various ways. For example, subfields of the signal section can be placed before the STF section, and the remaining subfields of the SIG section can be placed after the STF section.

[0490] The aforementioned legacy portion may include at least one of the following: traditional L-STF (non-HT short training field), L-LTF (non-HT long training field), and L-SIG (non-HT signal field).

[0491] The aforementioned SIG section (e.g., including the U-SIG field, UHR-SIG field, etc.) may include various control information for the transmitted PPDU. For example, it may include the STF section, the LTF section, and control information for decoding the data.

[0492] The STF portion mentioned above may include an STF sequence.

[0493] The LTF portion mentioned above may include training fields (i.e., LTF sequences) for channel estimation.

[0494] The aforementioned data portion may include user data and may also include packets for upper layers. That is, it may include MPDUs (MAC frames).

[0495] For example, the frames included in the MPDU may be LLT information and / or frames that trigger the LLT.

[0496] Figure 30The 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 be configured to perform PPDU exchange with other devices via a transceiver (106). Furthermore, one or more memories (104) of the first device (100) can store data for execution when performed by one or more processors (102). Figure 30 The example or instructions of the method described in the example above.

[0497] The processor (102) of the first device can be configured to perform operations of the device, which is a TXOP holder according to the example of this disclosure. For example, the processor (102) can be configured to send LLT information and / or trigger LLT PPDU / frames via transceiver (106).

[0498] Here, the memory (104) may store information about one or more LLT information described in this disclosure.

[0499] Figure 31 This is a diagram illustrating a method for sending and receiving data according to an embodiment of the present disclosure.

[0500] exist Figure 31 In this context, the first device refers to the device that is the TXOP holder (e.g., an AP device or a non-AP STA device), and the second device refers to the device that is the TXOP responder (e.g., a non-AP STA device or an AP device).

[0501] Figure 31 The diagram illustrates the operation of a second device acting as a TXOP responder based on the previously proposed method. Figure 31 The examples in this document are for illustrative purposes only and are not intended to limit the scope of this disclosure. Depending on the situation and / or configuration, details may be omitted. Figure 31 Some steps are shown in the diagram.

[0502] refer to Figure 31 The second device receives a PPDU from the first device to allow data transmission of the second device within the TXOP obtained by the first device (S3101).

[0503] Here, data transmission from the second device can refer to Low Latency Service (LLT) transmission.

[0504] Here, a PPDU used to allow data transmission of the second device may mean a PPDU / frame that transmits LLT information indicating that the second device needs data transmission and / or triggers LLT transmission.

[0505] Here, as described above, the operations described in the various embodiments can be performed within the TXOP provided by the first device to the second device.

[0506] The second device performs channel access (S3102) after TXOP has been terminated.

[0507] Here, channel access via the second device can be performed with a lower priority than channel access via other devices, including the first device. If the second device successfully receives a PPDU that allows data transmission through it, for example, the second device can notify the first device that it has successfully received the PPDU by sending an acknowledgment.

[0508] For example, channel access via a second device can be performed based on the LP EDCA parameter set. Compared to an EDCA parameter set without priority, the LP EDCA parameter set can be set to a higher AIFSN value and / or a higher CW maximum value (CWmax).

[0509] Additionally, for example, the LP EDCA parameter set may include a timer, and the LP EDCA parameter set may be available until the timer expires after TXOP has terminated.

[0510] In addition, the above LP EDCA parameter set can be announced by the AP in a beacon frame or probe response frame.

[0511] In step S3101, the PPDU may consist of a legacy portion, a SIG portion (e.g., U-SIG, UHR-SIG, etc.), an STF portion (e.g., UHR-STF), an LTF portion (e.g., UHR-LTF), and a data portion.

[0512] Any part (i.e., field) can be divided into multiple subparts / subfields, in whole or in part. Each field (and its subfields) can be divided into 4µs. The transmission unit is N (where N is an integer). Additionally, it can include a guard interval (GI). The common subcarrier frequency spacing value (delta_f = 312.5kHz / N or 312.5kHz) can be used. N, where N is an integer, can be applied to all fields, or the first delta_f can be applied to the first part (e.g., all of the legacy part, all / part of the SIG part), and the second delta_f (e.g., a value less than the first delta_f) can be applied to all / part of the remaining part.

[0513] Some of the fields mentioned above can be omitted, and the order of the fields can be changed in various ways. For example, subfields of the signal section can be placed before the STF section, and the remaining subfields of the SIG section can be placed after the STF section.

[0514] The aforementioned legacy portion may include at least one of the following: traditional L-STF (non-HT short training field), L-LTF (non-HT long training field), and L-SIG (non-HT signal field).

[0515] The aforementioned SIG section (e.g., including the U-SIG field, UHR-SIG field, etc.) may include various control information for the transmitted PPDU. For example, it may include the STF section, the LTF section, and control information for decoding the data.

[0516] The STF portion mentioned above may include an STF sequence.

[0517] The LTF portion mentioned above may include training fields (i.e., LTF sequences) for channel estimation.

[0518] The aforementioned data portion may include user data and packets for upper layers. In other words, it may include MPDUs (MAC frames).

[0519] For example, frames included in an MPDU may correspond to LLT information and / or frames that trigger an LLT.

[0520] Figure 31 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 be configured to perform PPDU exchange with another device via a transceiver (106). Furthermore, one or more memories (204) of the second device (200) can store data for execution by the one or more processors (202). Figure 31 The example or instructions of the method described in the example above.

[0521] The processor (202) of the second device may be configured to perform operations of the device as a TXOP responder according to the examples of this disclosure. For example, the processor (202) may be configured to receive LLT information and / or PPDU / frames that trigger LLTs via transceiver (206), and / or transmit frames containing LLT information and / or LLTs via transceiver (206).

[0522] Here, the memory (204) may store information about the LLT information described in this disclosure.

[0523] In existing wireless LAN systems, no preemption method is defined for a second device (non-AP STA or AP) to transmit data within a TXOP obtained by a first device (AP or non-AP STA). Instead, according to the DL / UL preemption method of this disclosure, one or more second devices can transmit DL / UL data within a TXOP obtained by a first device, thereby enabling the transmission and reception of low-latency services, reducing latency and increasing wireless communication efficiency. Furthermore, even after the TXOP terminates, it improves the fairness of channel access between the device providing the TXOP and the device receiving the TXOP.

[0524] 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.

[0525] 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.

[0526] 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 are executable 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 remotely 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.

[0527] [Industrial Applicability]

[0528] The method proposed in this disclosure is mainly described based on examples applied to IEEE 802.11-based systems and 5G systems, but it can also be applied to various WLAN or wireless communication systems other than those based on IEEE 802.11.

Claims

1. A method comprising: The first device sends a Physical Protocol Data Unit (PPDU) to the second device to allow data transmission by the second device within a Transmission Opportunity (TXOP) obtained by the first device; as well as After the TXOP has been terminated, the first device performs channel access. Wherein, based on the successful transmission of the PPDU to the second device, the channel access through the first device is performed with a higher priority than channel access through other devices including the second device.

2. The method according to claim 1, wherein, The channel access through the first device is performed based on the high-priority (HP) enhanced distributed channel access (EDCA) parameter set.

3. The method according to claim 2, wherein, Compared to EDCA parameter sets without priority, the HP EDCA parameter set is configured with a lower AIFSN (arbitrated interframe interval) value and / or a lower maximum contention window (CW).

4. The method according to claim 2, wherein, The HP EDCA parameter set includes a timer, and The HP EDCA parameter set is available after the TXOP has terminated and until the timer expires.

5. The method according to claim 2, wherein, The HP EDCA parameter set is announced by the access point (AP) in a beacon frame or probe response frame.

6. A method comprising: The second device receives a Physical Protocol Data Unit (PPDU) from the first device to allow data transmission by the second device within a Transmission Opportunity (TXOP) obtained by the first device; as well as After the TXOP has been terminated, the second device performs channel access. The channel access via the second device is performed with a lower priority than channel access via other devices including the first device.

7. The method according to claim 6, wherein, The channel access through the second device is performed based on the low-priority (LP) enhanced distributed channel access (EDCA) parameter set.

8. The method according to claim 7, wherein, Compared to EDCA parameter sets without priority, the LP EDCA parameter set is configured with a higher Arbitration Inter-Frame Spacing Number (AIFSN) value and / or a higher Contention Window (CW) maximum value.

9. The method according to claim 7, wherein, The LP EDCA parameter set includes a timer, and The LP EDCA parameter set is available after the TXOP has terminated and until the timer expires.

10. The method according to claim 7, wherein, The LP EDCA parameter set is announced by the access point (AP) in a beacon frame or probe response frame.

11. A first station (STA) device, 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: Sending a Physical Protocol Data Unit (PPDU) to the second device to allow data transmission by the second device within the Transmission Opportunity (TXOP) obtained by the first device; and After the TXOP has been terminated, channel access is performed. The channel access via the first device is performed with a higher priority than channel access via other devices including the second device.

12. A second station (STA) device, 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 Physical Protocol Data Units (PPDUs) from the first device to allow data transmission by the second device within a Transmission Opportunity (TXOP) obtained by the first device; and After the TXOP has been terminated, channel access is performed. The channel access via the second device is performed with a lower priority than channel access via other devices including the first device.

13. A processing device configured to control devices in a wireless local area network (WLAN) system, the processing device comprising: At least one processor; as well as At least one computer memory, operatively connected to at least one processor, and based on execution by at least one processor, storing instructions for performing the method according to any one of claims 1 to 10.

14. At least one non-transitory computer-readable medium, said non-transitory computer-readable medium storing at least one instruction, wherein: The at least one instruction is executed by at least one processor to control the device to perform the method according to any one of claims 1 to 10 in a wireless local area network (WLAN) system.

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