Method and apparatus for transmitting and receiving data by p2p method in wireless LAN system

Abstract

Disclosed are a method and an apparatus for operating in a wireless LAN system. According to one embodiment of the present disclosure, a method performed by a first STA in a wireless LAN system comprises the operations of: transmitting, to an access point (AP), a first frame including a first field for requesting peer-to-peer (P2P) data communication within a restricted target wake-up time (r-TWT); receiving, from the AP, a second frame including first information related to a time for the P2P data communication; and performing P2P data communication with the second STA within a time allocated by means of the first information, where the time allocated by means of the first information may be within an r-TWT service period (SP).

Description

Technical Field

[0001] The present disclosure relates to communication operations in a wireless local area network (WLAN) system, and more particularly, to a method and apparatus for transmitting and receiving data based on a peer-to-peer (P2P) method during a low-latency service transmission time in a next-generation wireless LAN system. Background Art

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

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

[0004] Technical Problem

[0005] A technical problem of the present disclosure is to provide a method and apparatus for transmitting and receiving data based on a P2P method during a low-latency service transmission time in a wireless LAN system.

[0006] A technical problem of the present disclosure is to provide a method and apparatus for requesting and responding to a time for transmitting delay-sensitive services in a P2P method in a wireless LAN system.

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

[0008] Technical Solution

[0009] According to an embodiment of the present disclosure, a method performed by a first station (STA) in a wireless LAN system may include the steps of: sending a first frame including a first field for requesting peer-to-peer (P2P) data communication within a restricted target wake time (r-TWT) to an access point (AP); receiving a second frame including first information related to time for P2P data communication from the AP; and performing the P2P data communication with a second STA within the time allocated by the first information, and the time allocated by the first information may be within an r-TWT service period (SP).

[0010] According to another embodiment of the present disclosure, a method performed by an access point (AP) in a wireless LAN system may include the steps of: receiving a first frame including a first field for requesting peer-to-peer (P2P) data communication within a restricted target wake time (r-TWT) from a first station (STA); sending a second frame including first information related to time for P2P data communication to the first STA; and performing communication with the first STA within the r-TWT service period (SP) after the time for P2P data communication has elapsed, and the time allocated by the first information may be within the r-TWT service period (SP).

[0011] Technical effects

[0012] According to various embodiments of the present disclosure, methods and apparatuses for transmitting and receiving data based on a P2P scheme within a low-latency service transmission time in a wireless LAN system may be provided.

[0013] According to various embodiments of the present disclosure, methods and apparatuses for requesting and responding to time for transmitting delay-sensitive services in a P2P scheme in a wireless LAN system may be provided.

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

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

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

[0017] Figure 2 Is a diagram illustrating an exemplary structure of a WLAN system to which the present disclosure may be applied.

[0018] Figure 3 This is a diagram for explaining the link establishment process to which the present disclosure can be applied.

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

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

[0021] Figure 6 This is a diagram for explaining an example of the frame structure used in a WLAN system to which the present disclosure can be applied.

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

[0023] Figure 8 This is a diagram for describing an example of an individual TWT operation to which the present disclosure can be applied.

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

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

[0026] Figure 11 This is a diagram for describing an example of the individual TWT parameter set field format.

[0027] Figure 12 This is a diagram for describing an example of the broadcast TWT parameter set field format.

[0028] Figure 13 This is a diagram for describing an example of the field format related to the restricted TWT operation.

[0029] Figure 14 This is a diagram for describing the operation of a first STA according to an embodiment of the present disclosure.

[0030] Figure 15 This is a diagram for describing the operation of an AP according to an embodiment of the present disclosure.

[0031] Figure 16 This is a diagram for describing a method for allocating time for P2P data transmission within an r-TWT SP according to an embodiment of the present disclosure.

[0032] Figure 17It is a diagram for describing a field for allocating time for P2P data transmission within an r-TWT SP according to an embodiment of the present disclosure. Detailed Embodiment

[0033] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed through the drawings is to describe exemplary embodiments of the present disclosure, and does not represent the only embodiments in which the present disclosure can be implemented. The following detailed description includes specific details to provide a complete understanding of the present disclosure. However, those skilled in the relevant art know that the present disclosure can be implemented without these specific details.

[0034] In some cases, known structures and devices may be omitted, or may be shown in the form of block diagrams based on the core functions of each structure and device to prevent the concepts of the present disclosure from being ambiguous.

[0035] In the present disclosure, when an element is referred to as being "connected", "combined", or "linked" to another element, it may include an indirect connection relationship and a direct connection relationship in which another element exists therebetween. In addition, in the present disclosure, the terms "include" or "have" specify the existence of the recited features, steps, operations, components, and / or elements, but do not exclude the existence or addition of one or more other features, stages, operations, components, elements, and / or groups thereof.

[0036] In the present disclosure, terms such as "first", "second", etc. are only used to distinguish one element from another element and do not limit the element. Unless otherwise specified, they do not limit the order or importance, etc. between the elements. Therefore, within the scope of the present disclosure, the first element in an embodiment may be referred to as the second element in another embodiment, and similarly, the second element in an embodiment may be referred to as the first element in another embodiment.

[0037] The terms used in the present disclosure are for describing specific embodiments and do not limit the claims. As used in the description of the embodiments and the appended claims, the singular form is intended to include the plural form unless the context clearly indicates otherwise. The term "and / or" used in the present disclosure may refer to one of the related recited items, or means that it refers to and includes any and all possible combinations of two or more of them. In addition, unless otherwise specified, the " / " between words in the present disclosure has the same meaning as "and / or".

[0038] Examples of the present disclosure can be applied to various wireless communication systems. For example, examples of the present disclosure can be applied to wireless LAN systems. For example, examples of the present disclosure can be applied to wireless LANs based on the IEEE 802.11a / g / n / ac / ax standards. In addition, examples of the present disclosure can be applied to wireless LANs based on the newly proposed IEEE 802.11be (or EHT) standard. Examples of the present disclosure can be applied to wireless LANs based on the IEEE 802.11be version 2 standard corresponding to additional enhancement technologies of the IEEE 802.11be version 1 standard. Additionally, examples of the present disclosure can be applied to wireless LANs based on next-generation standards after IEEE 802.11be. Furthermore, examples of the present disclosure can be applied to cellular wireless communication systems. For example, it can be applied to cellular wireless communication systems based on the Long-Term Evolution (LTE) technology and the 5G New Radio (NR) technology based on the Third Generation Partnership Project (3GPP) standards.

[0039] Hereinafter, technical features to which examples of the present disclosure can be applied will be described.

[0040] Figure 1 A block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0041] Figure 1 The first device 100 and the second device 200 illustrated in can be replaced with various terms such as a terminal, a wireless device, a wireless transmit / receive unit (WTRU), a user equipment (UE), a mobile station (MS), a user terminal (UT), a mobile subscriber station (MSS), a mobile subscriber unit (MSU), a subscriber station (SS), an advanced mobile station (AMS), a wireless terminal (WT), or simply a user. Additionally, the first device 100 and the second device 200 include an access point (AP), a base station (BS), a fixed station, a Node B, a base transceiver system (BTS), a network. It can be replaced with various terms such as an artificial intelligence (AI) system, a roadside unit (RSU), a repeater, a router, a relay, and a gateway.

[0042] Figure 1 The devices 100 and 200 illustrated in can be referred to as a station (STA). For example, Figure 1The apparatuses 100 and 200 illustrated in the example can be referred to by various terms such as a transmitting apparatus, a receiving apparatus, a transmitting STA, and a receiving STA. For example, STAs 110 and 200 can perform an access point (AP) role or a non-AP role. That is, in the present disclosure, STAs 110 and 200 can perform AP and / or non-AP functions. When STAs 110 and 200 perform the AP function, they can be simply referred to as APs, and when STAs 110 and 200 perform the non-AP function, they can be simply referred to as STAs. In addition, in the present disclosure, an AP can also be indicated as an AP STA.

[0043] Referring to Figure 1 , the first apparatus 100 and the second apparatus 200 can transmit and receive radio signals through various wireless LAN technologies (e.g., the IEEE 802.11 series). The first apparatus 100 and the second apparatus 200 can include interfaces for a media access control (MAC) layer and a physical layer (PHY) compliant with the IEEE 802.11 standard.

[0044] In addition, in addition to wireless LAN technologies, the first apparatus 100 and the second apparatus 200 can additionally support various communication standard (e.g., 3GPP LTE series, 5G NR series standards, etc.) technologies. In addition, the apparatuses of the present disclosure can be implemented in various apparatuses such as a mobile phone, a vehicle, a personal computer, an augmented reality (AR) device, and a virtual reality (VR) device. In addition, the STAs in 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.

[0045] 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, suggestions, methods, and / or operation flowcharts included in the present disclosure. For example, after generating first information / signals by processing information in the memory 104, the processor 102 may transmit a wireless signal including the first information / signals via the transceiver 106. Additionally, the processor 102 may receive a wireless signal including second information / signals via the transceiver 106, and then store the information obtained by signal processing of the second information / signals in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software code including instructions for performing all or part of the processing controlled by the processor 102 or for performing the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts included in the present disclosure. Here, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., the IEEE 802.11 series). The transceiver 106 may be connected to the processor 102 and may transmit and / or receive wireless signals via one or more antennas 108. The transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used with an RF (radio frequency) unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0046] 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, suggestions, methods, and / or operation flowcharts included in the present disclosure. For example, the processor 202 may generate third information / signals by processing the information in the memory 204, and then transmit a wireless signal including the third information / signals through the transceiver 206. Additionally, the processor 202 may receive a wireless signal including fourth information / signals through the transceiver 206, and then store the information obtained by 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 processing controlled by the processor 202 or for performing the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts included in the present disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., the IEEE 802.11 series). The transceiver 206 may be connected to the processor 202 and may transmit and / or receive wireless signals through one or more antennas 208. The transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used with an RF unit. In the present disclosure, a device may mean a communication modem / circuit / chip.

[0047] Hereinafter, the hardware components of apparatuses 100 and 200 will be described in more detail. Without being limited thereto, 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, procedures, suggestions, methods, and / or operation flowcharts disclosed in the present disclosure. One or more processors 102 and 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or operation flowcharts disclosed in the present 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, procedures, suggestions, and / or methods disclosed in the present disclosure to provide them to one or more transceivers 106 and 206. One or more processors 102 and 202 may receive signals (e.g., baseband signals) from one or more transceivers 106 and 206 according to the descriptions, functions, procedures, suggestions, methods, and / or operation flowcharts included in the present disclosure, and obtain PDUs, SDUs, messages, control information, data, or information.

[0048] One or more processors 102 and 202 may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. One or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processor 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 and 202. The descriptions, functions, procedures, suggestions, methods, and / or operation flowcharts included in the present disclosure may be implemented by using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The firmware or software configured to execute the descriptions, functions, procedures, suggestions, methods, and / or operation flowcharts included in the present disclosure may be included in one or more processors 102 and 202, or may be stored in one or more memories 104 and 204 and driven by one or more processors 102 and 202. The descriptions, functions, procedures, suggestions, methods, and / or operation flowcharts included in the present disclosure may be implemented by using firmware or software in the form of code, instructions, and / or instruction sets.

[0049] One or more memories 104, 204 may be connected to one or more processors 102, 202 and may store 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 drives, registers, cache memories, computer-readable storage media, and / or combinations thereof. One or more memories 104, 204 may be located inside and / or outside one or more processors 102, 202. Additionally, one or more memories 104, 204 may be connected to one or more processors 102, 202 through various techniques such as wired or wireless connections.

[0050] One or more transceivers 106, 206 may send user data, control information, wireless signals / channels, etc. mentioned in the methods and / or operation flowcharts, etc. of the present disclosure to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts, etc. included in the present disclosure from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and may send and receive wireless signals. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to send user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors 102, 202 may control one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. Additionally, 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 send and receive user data, control information, wireless signals / channels, etc. mentioned in the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts, etc. included in the present disclosure via one or more antennas 108, 208. In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106, 206 may convert the received wireless signals / channels, etc. from RF band signals into baseband signals to process the received user data, control information, wireless signals / channels, etc. by using one or more processors 102, 202. One or more transceivers 106, 206 may convert the user data, control information, wireless signals / channels, etc. processed by using one or more processors 102, 202 from baseband signals into RF band signals. Thus, one or more transceivers 106, 206 may include (analog) oscillators and / or filters.

[0051] For example, one of the STAs 100 and 200 may perform the expected operations of an AP, and the other of the STAs 100 and 200 may perform the expected operations of a non-AP STA. For example, Figure 1 the transceivers 106 and 206 may perform the operations of sending and receiving signals (e.g., packets or physical layer protocol data units (PPDUs) compliant with IEEE 802.11a / b / g / n / ac / ax / be / bn). Additionally, in the present disclosure, the operations of various STAs generating transmit / receive signals or pre-processing or calculating data for transmit / receive signals may be performed by Figure 1are executed by processors 102 and 202. For example, examples of operations for generating transmission / reception signals or performing data processing or calculations on transmission / reception signals in advance may include: 1) determining / acquiring / configuring / calculating / decoding / encoding bit information of fields (signals (SIG), short training fields (STF), long training fields (LTF), data, etc.) included in a PPDU; 2) determining / configuring / acquiring time resources or frequency resources (e.g., subcarrier resources) for fields (SIG, STF, LTF, data, etc.) included in a PPDU; 3) determining / configuring / acquiring specific sequences (e.g., pilot sequences, STF / LTF sequences, additional sequences applied to SIG) for fields (SIG, STF, LTF, data, etc.) included in PPDU operations; 4) power control operations and / or power saving operations applied to a STA; 5) operations related to ACK signal determination / acquisition / configuring / calculating / decoding / encoding, etc. Additionally, in the following examples, various information (e.g., information related to fields / sub-fields / control fields / parameters / power, etc.) used by various STAs to determine / acquire / configure / calculate / decode / encode transmission signals and reception signals may be stored in Figure 1 memories 104 and 204.

[0052] Hereinafter, a downlink (DL) may refer to a link for communication from an AP STA to a non-AP STA, and DL PPDUs / packets / signals may be transmitted and received through the DL. In DL communication, a transmitter may be part of an AP STA, and a receiver may be part of a non-AP STA. An uplink (UL) may refer to a link for communication from a non-AP STA to an AP STA, and UL PPDUs / packets / signals may be transmitted and received through the UL. In UL communication, a transmitter may be part of a non-AP STA, and a receiver may be part of an AP STA.

[0053] Figure 2 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure may be applied.

[0054] The structure of a wireless LAN system may be composed of multiple components. A wireless LAN that supports STA mobility transparent to an upper layer may be provided through the interaction of multiple components. A basic service set (BSS) corresponds to a basic building block of a wireless LAN. Figure 2 Exemplarily, it is shown that there are two BSSs (BSS1 and BSS2), and two STAs included as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). Figure 2The ellipse representing the BSS can also be understood as representing the coverage area where STAs included in the corresponding BSS maintain communication. This area can be referred to as the Basic Service Area (BSA). When an STA moves outside the BSA, it cannot communicate directly with other STAs within the BSA.

[0055] If the DS shown in Figure 2 is not considered, the most basic type of BSS in a wireless LAN is the Independent BSS (IBSS). For example, an IBSS can have a minimum form that only contains two STAs. For example, assuming other components are omitted, BSS1 that only contains STA1 and STA2 or BSS2 that only contains STA3 and STA4 can respectively correspond to representative examples of an IBSS. This configuration is possible when STAs can communicate directly without an AP. Additionally, in this type of wireless LAN, it is not pre-configured but can be configured when a LAN is needed, and this can be referred to as an ad-hoc network. Since 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 be composed of mobile STAs and are not allowed to access the Distributed System (DS), thus forming a self-contained network.

[0056] The membership of STAs in a BSS can be dynamically changed by turning on or off STAs, entering or exiting the BSS area, etc. To become a member of a BSS, an STA can use synchronization processing to join the BSS. To access all services of the BSS infrastructure, an STA should be associated with the BSS. This association can be dynamically established and can include using the Distribution System Service (DSS).

[0057] The direct STA-to-STA distance in a wireless LAN may be limited by the PHY performance. In some cases, this distance limitation may be sufficient, but in some cases, communication between STAs at longer distances may be required. The Distributed System (DS) can be configured to support extended coverage.

[0058] DS means the structure for interconnecting BSSs. Specifically, as Figure 2As shown, the BSS can exist as an extended form of a network composed of multiple BSSs. The DS is a logical concept and can be specified by the characteristics of the distributed system medium (DSM). In this regard, the wireless medium (WM) and the DSM can be logically separated. Each logical medium is used for different purposes and is used by different components. These media are not limited to being the same, nor are they limited to being different. In this way, the flexibility of the wireless LAN structure (DS structure or other network structures) can be interpreted as multiple media being logically different. That is, the wireless LAN structure can be implemented in various ways, and the corresponding wireless LAN structure can be independently specified by the physical characteristics of each implementation.

[0059] The DS can support mobile devices by providing seamless integration of multiple BSSs and providing the logical services necessary for addressing the addresses to the destination. Additionally, the DS can also include a component called a portal, which is used as a bridge for the connection between the wireless LAN and other networks (e.g., IEEE 802.X).

[0060] The AP enables access to the DS via the WM for the associated non-AP STA and refers to an entity that also has the STA function. The data movement between the BSS and the DS can be performed by the AP. For example, Figure 2 STA2 and STA3 shown in have the function of the STA and provide the function of allowing the associated non-AP STAs (STA1 and STA4) to access the DS. Additionally, since all APs basically correspond to STAs, all APs are addressable entities. The address used by the AP for communication on the WM is not necessarily the same as the address used by the AP for communication on the DSM. The BSS composed of an AP and one or more STAs can be called an infrastructure BSS.

[0061] Data sent from one of the STAs associated with the AP to the STA address of the corresponding AP can always be received at the uncontrolled port and can be processed by the IEEE 802.1X port access entity. Additionally, when the controlled port is authenticated, the transmitted data (or frame) can be delivered to the DS.

[0062] In addition to the above DS structure, the extended service set (ESS) can also be configured to provide wide coverage.

[0063] An ESS refers to a network consisting of a DS and BSSs with arbitrary size and complexity. An ESS can correspond to a set of BSSs connected to a DS. However, an ESS does not include the DS. The ESS network is characterized by being regarded as an IBSS in the logical link control (LLC) layer. STAs included in an ESS can communicate with each other, and a mobile STA can move from one BSS to another (within the same ESS) transparently to the LLC. APs included in an ESS can have the same service set identifier (SSID). The SSID is distinguished from the BSSID which is the identifier of a BSS.

[0064] The wireless LAN system does not assume anything about the relative physical positions of BSSs, and all of the following forms are possible. BSSs can partially overlap, which is a form commonly used to provide continuous coverage. Additionally, BSSs can be physically unconnected, and logically, there is no limit to the distance between BSSs. Additionally, BSSs can be physically located at the same position, which can be used to provide redundancy. Additionally, one (or more than one) IBSS or ESS network can physically exist in the same space as one (or more than one) ESS network. This can correspond to forms of an ESS network when an ad hoc network operates in a location where an ESS network exists, when physically overlapping wireless networks are configured by different organizations, or when two or more different access and security policies are required at the same location.

[0065] Figure 3 is a diagram for explaining the link establishment process to which the present disclosure can be applied.

[0066] In order for an STA to establish a link with respect to a network and send / receive data, it first discovers the network, performs authentication, establishes an association, and an authentication process is required for security. The link establishment process can also be referred to as a session initiation process or a session establishment process. Additionally, the processes of discovery, authentication, association, and security establishment in the link establishment process can be collectively referred to as an association process.

[0067] In step S310, the STA can perform a network discovery operation. The network discovery operation can include a scanning operation of the STA. That is, in order for the STA to access the network, it needs to find a network it can participate in. The STA should identify compatible networks before participating in a wireless network, and the process of identifying the networks existing in a specific area is called scanning.

[0068] Scanning schemes include active scanning and passive scanning. Figure 3A network discovery operation including an active scanning process is exemplarily illustrated. In active scanning, the STA performing the scan sends a probe request frame to discover which APs exist around it while moving across channels and waits for a response thereto. The responder sends a probe response frame as a response to the probe request frame to the STA that has sent the probe request frame. Here, the responder can be the STA that last sent a beacon frame in the BSS of the channel being scanned. In a BSS, since the AP sends a beacon frame, the AP becomes the responder, and in an IBSS, the STAs in the IBSS rotate to send beacon frames, so the responder is not constant. For example, the 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 the scan in the same way (i.e., send and receive probe requests / responses on channel 2).

[0069] Although not shown in Figure 3 it, the scan operation can be performed in a passive scanning manner. In passive scanning, the STA performing the scan waits for beacon frames while moving across channels. A beacon frame is one of the management frames defined in IEEE 802.11 and is sent periodically to notify the existence of a wireless network and to allow the STA performing the scan to find the wireless network and participate in the wireless network. In a BSS, the AP is used to send beacon frames periodically, and in an IBSS, the STAs within the IBSS rotate to send beacon frames. When the STA performing the scan receives a beacon frame, the STA stores the information of the BSS included in the beacon frame, and while moving to another channel, records the beacon frame information in each channel. The STA that receives a 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 way. Comparing active scanning with passive scanning, the advantage of active scanning is that it has less latency and less power consumption than passive scanning.

[0070] After the STA discovers the network, the authentication process can be performed in step S320. To clearly distinguish it from the security establishment operation in step S340 to be described later, this authentication process can be referred to as the first authentication process.

[0071] The authentication process includes the following processes: The STA sends an authentication request frame to the AP, and in response thereto, the AP sends an authentication response frame to the STA. The authentication frames for authentication request / response correspond to management frames.

[0072] The authentication frame includes an authentication algorithm number, an authentication transaction serial number, a status code, a challenge text, a Robust Security Network (RSN), a finite cyclic group, etc. This corresponds to some examples of information that can be included in the authentication request / response frame, and can be replaced with other information, or additional information can also be included.

[0073] The STA can send an authentication request frame to the AP. The AP can determine whether to allow the authentication of the corresponding STA based on the information included in the received authentication request frame. The AP can provide the result of the authentication process to the STA through an authentication response frame.

[0074] After the STA is successfully authenticated, the association process can be performed in step S330. The association process includes the following processes: the STA sends an association request frame to the AP, and in response, the AP sends an association response frame to the STA.

[0075] For example, the association request frame can include information related to various capabilities, a beacon listening interval, a Service Set Identifier (SSID), supported rates, supported channels, RSN, a mobility domain, supported operation classes, a Traffic Indication Map Broadcast Request (TIM broadcast request), interoperable service capabilities, etc. For example, the association response frame can include information related to various capabilities, a status code, an Association ID (AID), supported rates, an Enhanced Distributed Channel Access (EDCA) parameter set, a Received Channel Power Indicator (RCPI), a Received Signal-to-Noise Ratio Indicator (RSNI), a mobility domain, a timeout interval (e.g., an association recovery time), overlapping BSS scan parameters, a TIM broadcast response, Quality of Service (QoS) mapping, etc. This corresponds to some examples of information that can be included in the association request / response frame, and can be replaced with other information, or additional information can also be included.

[0076] After the STA is successfully associated with the network, the security establishment process can be performed in step S340. The security establishment process in step S340 can be referred to as an authentication process through a Robust Security Network Association (RSNA) request / response. The authentication process in step S320 is referred to as the first authentication process, and the security establishment process in step S340 can also simply be referred to as an authentication process.

[0077] The security establishment process in step S340 can include, for example, a process of establishing a private key using the Extensible Authentication Protocol over LAN (EAPOL) frame through a four-way handshake. Additionally, the security establishment process can be performed according to a security scheme not defined in the IEEE 802.11 standard.

[0078] Figure 4 It is a diagram for explaining the backoff process to which the present disclosure can be applied.

[0079] In a wireless LAN system, the basic access mechanism of the Medium Access Control (MAC) is the Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) mechanism. The CSMA / CA mechanism is also referred to as the Distributed Coordination Function (DCF) of the IEEE 802.11 MAC and basically adopts a "listen before talk" access mechanism. According to this type of access mechanism, before starting to transmit, the AP and / or STA can perform a Clear Channel Assessment (CCA) of sensing the radio channel or medium during a predetermined time interval (e.g., the DCF Interframe Space (DIFS)). As a result of the sensing, if it is determined that the medium is idle, frame transmission is started 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 start its own transmission and can set a delay period for medium access (e.g., a random backoff period) and attempt frame transmission after waiting. By applying the random backoff period, since it is expected that multiple STAs will attempt frame transmission after waiting for different time periods, collisions can be minimized.

[0080] In addition, the IEEE 802.11 MAC protocol provides a Hybrid Coordination Function (HCF). The HCF is based on the DCF and the Point Coordination Function (PCF). The PCF is a polling-based synchronous access method and refers to a method in which all receiving APs and / or STAs are polled periodically to receive data frames. In addition, the HCF has an Enhanced Distributed Channel Access (EDCA) and an HCF Controlled Channel Access (HCCA). The EDCA is a contention-based access method that provides data frames to multiple users in a direction, and the HCCA uses a non-contention-based channel access method that utilizes a polling mechanism. In addition, the HCF includes a medium access mechanism for improving the Quality of Service (QoS) of the wireless LAN and can transmit QoS data during a Contention Period (CP) and a Contention Free Period (CFP).

[0081] Refer to Figure 4, operations based on a random backoff period will be described. When the occupied / busy medium becomes idle, multiple STAs can attempt to send data (or frames). As a method of minimizing collisions, each of the STAs can separately select a random backoff count and attempt to send after waiting for the corresponding slot time. The random backoff count has a pseudo-random integer value and can be determined as one of the values that vary from 0 to the value of CW. Here, CW is the contention window parameter value. The CW parameter is given the initial value of CWmin, but can take a value twice as large in the case of a transmission failure (e.g., when an ACK for the transmitted frame is not received). When the CW parameter value reaches CWmax, data transmission can be attempted while maintaining the CWmax value until the data transmission is successful, and when the data transmission is successful, the CWmin value is reset. The values of CW, CWmin, and CWmax are preferably set to 2n - 1 (n = 0, 1, 2,...).

[0082] When the random backoff process starts, the STA continuously monitors the medium during the countdown of the backoff slot according to the determined backoff count value. When monitoring the medium for occupancy, it stops the countdown and waits, and when the medium becomes idle, it resumes the remaining part of the countdown.

[0083] In Figure 4 the example, when the packet to be sent arrives at the MAC of STA 3, STA3 can send the frame immediately after confirming that the medium has been idle for up to DIFS. The remaining STAs monitor and wait for the medium to be occupied / busy. Meanwhile, the data to be sent can also occur in each of STA1, STA2, and STA5, and when the medium is monitored as idle, each STA waits for up to DIFS and then can perform the countdown of the backoff slot according to the random backoff count value selected by each STA. Assume that STA2 selects the minimum backoff count value and STA1 selects the maximum backoff count value. That is, the situation where the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1 when STA2 completes the backoff count and starts frame transmission is exemplified. STA1 and STA5 temporarily stop the countdown and wait while STA2 occupies the medium. When the occupancy of STA2 ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and resume the stopped backoff count. That is, frame transmission can start after counting down the remaining backoff slots for the remaining backoff time. Since the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1, STA5 starts frame transmission. While STA2 occupies the medium, the data to be sent can also occur in STA4. From the perspective of STA4, when the medium becomes idle, STA4 can wait for DIFS and then can perform the countdown according to the random backoff count value selected by STA4 and start sending the frame. Figure 4The example shows a situation where the remaining backoff time of STA5 accidentally conflicts with the random backoff counter value of STA4. In this case, a conflict may occur between STA4 and STA5. When a conflict occurs, neither STA4 nor STA5 receives an ACK, so the data transmission fails. In this case, STA4 and STA5 can double the CW value, select a random backoff counter value, and perform countdown. When the medium is occupied due to the transmissions of STA4 and STA5, STA1 waits. When the medium becomes idle, STA1 waits for DIFS, and then starts frame transmission after the remaining backoff time has passed.

[0084] As in Figure 4 the example, the data frame is a frame for transmitting data forwarded to a higher layer, and can be transmitted after performing backoff after DIFS has elapsed since the medium became idle. Additionally, the management frame is a frame for exchanging management information that is not forwarded to a higher layer, and is transmitted after performing backoff after an IFS such as DIFS or Point Coordination Function IFS (PIFS). As subtype frames of the management frame, there are beacon, association request / response, re-association request / response, probe request / response, authentication request / response, etc. The control frame is a frame for controlling access to the medium. As subtype frames of the control frame, there are Request To Send (RTS), Clear To Send (CTS), Acknowledgment (ACK), Power Save Poll (PS-Poll), Block Ack (BlockAck), Block ACK Request (BlockACKReq), Null Data Packet Announcement (NDP Announcement), and Trigger, etc. If the control frame is not a response frame to the previous frame, it is transmitted after performing backoff after DIFS, and if it is a response frame to the previous frame, it is transmitted without performing backoff after Short IFS (SIFS). The type and subtype of the frame can be identified by the type field and subtype field in the Frame Control (FC) field.

[0085] The Quality of Service (QoS) STA can perform backoff after Arbitration IFS (AIFS) for the access category (AC) to which the frame belongs (i.e., AIFS (where i is a value determined by the AC)), and then can transmit the frame. Here, the frame for which AIFS can be used can be a data frame, a management frame, or a control frame other than a response frame.

[0086] Figure 5 is a diagram for explaining the CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0087] As described above, in addition to the physical carrier sensing of the medium directly by the STA, the CSMA / CA mechanism also includes virtual carrier sensing. Virtual carrier sensing aims to compensate for problems such as the hidden node problem that may occur in medium access. For virtual carrier sensing, the MAC of the STA can use the Network Allocation Vector (NAV). The NAV is a value that indicates to other STAs the remaining time until the medium is available for use by the STA that currently has access to or is entitled to use the medium. Therefore, the value set as the NAV corresponds to the period during which the STA that transmits the frame plans to use the medium, and during the corresponding period, the STA that receives the NAV value is prohibited from accessing the medium. For example, the NAV can be configured based on the value of the "Duration" field in the MAC header of the frame.

[0088] In Figure 5 the example, it is assumed that STA1 aims to send data to STA2, and STA3 is in a position where it can overhear some or all of the frames transmitted and received between STA1 and STA2.

[0089] To reduce the possibility of transmission collisions of multiple STAs in the CSMA / CA-based frame transmission operation, a mechanism using RTS / CTS frames can be applied. In Figure 5 the example, when the transmission of STA1 is being executed, as a result of the carrier sensing of STA3, it can be determined that the medium is in an idle state. That is, STA1 can correspond to a hidden node with respect to STA3. Alternatively, in Figure 5 the example, it can be determined that when the transmission of STA2 is being executed, the carrier sensing result of STA3 indicates that the medium is in an idle state. That is, STA2 can correspond to a hidden node with respect to STA3. By exchanging RTS / CTS frames before data transmission and reception between STA1 and STA2, STAs outside the transmission range of either STA1 or STA2 or STAs outside the carrier sensing range of the transmission from STA1 or STA3 can refrain from attempting to occupy the channel during the data transmission and reception between STA1 and STA2.

[0090] Specifically, STA1 can determine whether the channel is being used through carrier sensing. In terms of physical carrier sensing, STA1 can determine the occupied or idle state of the channel based on the energy level or signal correlation detected in the channel. Additionally, in terms of virtual carrier sensing, STA1 can use the Network Allocation Vector (NAV) timer to determine the channel occupancy state.

[0091] When the channel is in an idle state 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 as a response to the RTS frame after SIFS.

[0092] If STA3 cannot overhear the CTS frame from STA2 but can overhear the RTS frame from STA1, STA3 can use the duration information included in the RTS frame to set the NAV timer for the transmission period of the frames continuously sent thereafter (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame). Alternatively, if STA3 can overhear the CTS frame from STA2, even though STA3 cannot overhear the RTS frame from STA1, STA3 can also use the duration information included in the CTS frame to set the NAV timer for the transmission period of the frames continuously sent thereafter (e.g., SIFS + data frame + SIFS + ACK frame). That is, if STA3 can overhear one or more of the RTS frames or CTS frames from one or more of STA1 or STA2, STA3 can set the NAV accordingly. When STA3 receives a new frame before the NAV timer expires, STA3 can use the duration information included in the new frame to update the NAV timer. STA3 does not attempt channel access until the NAV timer expires.

[0093] When STA1 receives the CTS frame from STA2, STA1 can send a data frame to STA2 after SIFS from the time point when the reception of the CTS frame is completed. When STA2 successfully receives the data frame, STA2 can send an ACK frame to STA1 after SIFS as a response to the data frame. When the NAV timer expires, STA3 can determine whether the channel is being used through carrier sensing. When STA3 determines during the DIFS period after the NAV timer expires that the channel is not being used by other terminals, STA3 can attempt channel access after the contention window (CW) according to random backoff has elapsed.

[0094] Figure 6 is a diagram for illustrating an example of the frame structure used in a WLAN system to which the present disclosure can be applied.

[0095] With instructions or primitives (meaning a set of instructions or parameters) from the MAC layer, the PHY layer can prepare the MAC PDU (MPDU) to be transmitted. For example, when receiving a command from the MAC layer to request the start of transmission by the PHY layer, the PHY layer switches to the transmission mode, configures the information (e.g., data) provided by the MAC layer in the form of a frame, and transmits it. In addition, when the PHY layer detects the valid preamble of the received frame, the PHY layer monitors the header of the preamble and sends a command to the MAC layer notifying the start of reception by the PHY layer.

[0096] 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) format is defined.

[0097] The basic PPDU may 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) shown in

[0098] can consist only of a legacy-STF (L-STF), a legacy-LTF (L-LTF), a legacy-SIG (L-SIG) field, and a Data field. Additionally, depending on the type of PPDU format (e.g., HT mixed format PPDU, HT greenfield format PPDU, VHT (Very High Throughput) PPDU, etc.), additional (or different types of) RL-SIG, U-SIG, non-legacy SIG fields, non-legacy STF, non-legacy LTF (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)) etc. may be included between the L-SIG field and the Data field.

[0099] The SIG field may include various information related to PPDU transmission and reception. For example, the L-SIG field consists of 24 bits, and the L-SIG field may include a 4-bit Rate field, a 1-bit Reserved bit, a 12-bit Length field, a 1-bit Parity field, and a 6-bit Tail field. The RATE field may include information about the modulation and coding rate of the data. For example, the 12-bit Length field may include information about the length or duration of the PPDU. For example, the value of the 12-bit Length field may be determined based on the type of PPDU. For example, for non-HT, HT, VHT, or EHT PPDU, the value of the Length field may be determined to be a multiple of 3. For example, for HE PPDU, the value of the Length field may be determined to be a multiple of 3 + 1 or 3 + 2.

[0100] The data field may include a SERVICE field, a Physical Layer Service Data Unit (PSDU), and PPDU tail bits, and may also include padding bits if necessary. Some bits of the SERVICE field may be used for synchronization of the descrambler at the receiving end. The PSDU corresponds to the MAC PDU defined in the MAC layer and may include data generated / used in the upper layer. The PPDU tail bits may be used to return the encoder to the 0 state. The padding bits may be used to adjust the length of the data field in predetermined units.

[0101] The MAC PDU is defined according to various MAC frame formats, and the basic MAC frame consists of a MAC header, a frame body, and a Frame Check Sequence (FCS). The MAC frame may be composed of MAC PDUs and sent / received through the PSDU of the data part in the PPDU format.

[0102] The MAC header includes a Frame Control field, a Duration / ID field, an Address field, etc. The Frame Control field may include control information required for frame transmission / reception. The Duration / ID field may be set to the time for transmitting the corresponding frame, etc. For details of the Sequence Control, QoS Control, and HT Control sub-fields of the MAC header, refer to the IEEE 802.11 standard literature.

[0103] The Null Data PPDU (NDP) format refers to the PPDU format that does not include a data field. In other words, the NDP refers to a frame format that includes the PPDU preamble of the general PPDU format (i.e., the L-STF, L-LTF, L-SIG fields, and additional non-traditional SIG, non-traditional STF, non-traditional LTF (if any)) and does not include the remaining part (i.e., the data field).

[0104] Figure 7 FIG. is an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0105] In standards such as IEEE 802.11a / g / n / ac / ax, various types of PPDUs have been used. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and a data field. The basic PPDU format may also be referred to as the non-HT PPDU format (as shown in (a) of Figure 7 ).

[0106] Compared with the basic PPDU format, the HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT fields. Figure 7The HT PPDU format shown in (b) can be referred to as the HT mixed format. Additionally, an HT greenfield format PPDU can be defined, and this corresponds to a format (not shown) 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.

[0107] Compared with the basic PPDU format, an example of the VHT PPDU format (IEEE 802.11ac) additionally includes VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields (as Figure 7 shown in (c)).

[0108] Compared with the basic PPDU format, an example of the HE PPDU format (IEEE 802.11ax) additionally includes a repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF, and packet extension (PE) fields (as Figure 7 shown in (d)). Some fields can be excluded, or their lengths can vary according to the detailed example of the HE PPDU format. For example, the HE-SIG-B field is included in the HE PPDU format for multi-user (MU), and the HE-SIG-B is not included in the HE PPDU format for single-user (SU). Additionally, the HE trigger-based (TB) PPDU format does not include HE-SIG-B, and the length of the HE-STF field can vary to 8 μs. The extended range (HE ER) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field can vary to 16 μs. For example, RL-SIG can be configured to be the same as L-SIG. Based on the presence of RL-SIG, the receiving STA can know that the received PPDU is an HE PPDU or an EHT PPDU, which will be described later.

[0109] The EHT PPDU format can include Figure 7 the EHT MU (multi-user) in (e) and Figure 7 the EHT TB (trigger-based) PPDU in (f). The EHT PPDU format is similar to the HE PPDU format in including RL-SIG following L-SIG, but can include U (universal)-SIG, EHT-SIG, EHT-STF, and EHT-LTF following RL-SIG.

[0110] Figure 7The EHT MU PPDU in (e) corresponds to a PPDU carrying one or more data (or PSDU) for one or more users. That is, the EHT MU PPDU can be used for both SU transmission and MU transmission. For example, the EHT MU PPDU can correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0111] Compared with the EHT MU PPDU, Figure 7 The EHT TB PPDU in (f) omits the EHT-SIG. A STA that receives a trigger for UL MU transmission (e.g., a trigger frame or a triggered response schedule (TRS)) can perform UL transmission based on the EHT TB PPDU format.

[0112] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (universal signal), and EHT-SIG fields can be encoded and modulated so that even traditional STAs can attempt to demodulate and decode, and can be mapped based on the determined subcarrier frequency spacing (e.g., 312.5 kHz). These can be referred to as pre-EHT modulation fields. Next, the EHT-STF, EHT-LTF, data, and PE fields can be encoded and modulated to be demodulated and decoded by a STA that successfully decodes a non-traditional SIG (e.g., U-SIG and / or EHT-SIG) and obtains the information included in this field, and can be mapped based on the determined subcarrier frequency spacing (e.g., 78.125 kHz). These can be referred to as EHT modulation fields.

[0113] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields can be referred to as pre-HE modulation fields, and the HE-STF, HE-LTF, data, and PE fields can be referred to as HE modulation fields. Additionally, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields can be referred to as non-VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and data fields can be referred to as VHT modulation fields.

[0114] Included in Figure 7The U-SIG in the EHT PPDU format can be configured based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG can have a duration of 4 μs, and the U-SIG can have a total duration of 8 μs. Each symbol of the U-SIG can be used to transmit 26 bits of information. For example, each symbol of the U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0115] The U-SIG can be constructed in units of 20 MHz. For example, if an 80 MHz PPDU is constructed, the U-SIG can be replicated. That is, the same 4 U-SIGs can be included in the 80 MHz PPDU. A PPDU with a bandwidth exceeding 80 MHz can include different U-SIGs.

[0116] For example, A uncoded bits can be transmitted through the U-SIG. The first symbol of the U-SIG (e.g., the U-SIG-1 symbol) can transmit the first X bits of information out of a total of A bits of information, and the second symbol of the U-SIG (e.g., the U-SIG-2 symbol) can transmit the remaining Y bits of information out of a total of A bits of information. The A bits of information (e.g., 52 uncoded bits) can include a CRC field (e.g., a 4-bit long field) and a tail field (e.g., a 6-bit long field). For example, the tail field can be used to terminate the trellis structure of the convolutional decoder and can be set to 0.

[0117] The bit information transmitted through the U-SIG can be divided into version-independent bits and version-dependent bits. For example, the U-SIG can be included in Figure 7 a new PPDU format not shown (e.g., the UHR PPDU format), and can be included in the format of the U-SIG field included in the EHT PPDU format and the format of the U-SIG field included in the UHR PPDU format. The version-independent bits can be the same, and some or all of the version-dependent bits can be different.

[0118] For example, the size of the version-independent bits of the U-SIG can be fixed or variable. The version-independent bits can be assigned only to the U-SIG-1 symbol, or assigned to both the U-SIG-1 symbol and the U-SIG-2 symbol. The version-independent bits and the version-dependent bits can be called various names, such as the first control bit and the second control bit.

[0119] For example, the version - independent bits of U - SIG can include 3 - bit Physical Layer Version Identifier (PHY version identifier), and this information can indicate the PHY version of the transmitted / received PPDU (e.g., EHT, UHR, etc.). The version - independent bits of U - SIG can include a 1 - bit UL / DL flag field. The first value of the 1 - bit UL / DL flag field is related to UL communication, and the second value of the UL / DL flag field is related to DL communication. The version - independent bits of U - SIG can include information about the length of the Transmission Opportunity (TXOP) and information about the BSS color ID.

[0120] For example, the version - related bits of U - SIG can include information that directly or indirectly indicates the type of the PPDU (e.g., SU PPDU, MU PPDU, TB PPDU, etc.).

[0121] The information required for PPDU transmission and reception can be included in U - SIG. For example, U - SIG can also include information about the bandwidth, information about the MCS technique applied to non - traditional SIGs (e.g., EHT - SIG or UHR - SIG, etc.), information indicating whether the DCM (Dual - Carrier Modulation) technique (e.g., a technique for achieving an effect similar to frequency diversity by reusing the same signal on two sub - carriers) is applied to non - traditional SIGs, information about the number of symbols for non - traditional SIGs, information about whether non - traditional SIGs are generated across the entire frequency band.

[0122] Some of the information required for PPDU transmission and reception can be included in U - SIG and / or non - traditional SIGs (e.g., EHT - SIG or UHR - SIG, etc.). For example, information about the type of non - traditional LTF / STF (e.g., EHT - LTF / EHT - STF or UHR - LTF / UHR - STF, etc.), information about the length of non - traditional LTF and the CP (Cyclic Prefix) length, information about the GI (Guard Interval) applicable to non - traditional LTF, information about the preamble puncturing applicable to the PPDU, information about the Resource Unit (RU) allocation, etc. can be included only in U - SIG, only in non - traditional SIG, or can be indicated by a combination of the information included in U - SIG and the information included in non - traditional SIG.

[0123] Preamble puncturing can represent the transmission of the following PPDU, where there is no signal in one or more frequency units among the bandwidth of the PPDU. For example, the size of the frequency unit (or the resolution of the preamble puncturing) can be defined as 20 MHz, 40 MHz, etc. For example, preamble puncturing can be applied to a PPDU bandwidth of a predetermined size or larger.

[0124] In Figure 7In an example, non - traditional SIGs such as HE - SIG - B and EHT - SIG can include control information for receiving STAs. The non - traditional SIG can be sent on at least one symbol, and one symbol can have a length of 4 μs. Information about the number of symbols for EHT - SIG can be included in a previous SIG (e.g., HE - SIG - A, U - SIG, etc.).

[0125] Non - traditional SIGs such as HE - SIG - B and EHT - SIG can include a common field and user - specific fields. The common field and user - specific fields can be encoded separately.

[0126] In some cases, the common field can be omitted. For example, in a compressed mode that does not apply OFDMA (Orthogonal Frequency Division Multiple Access), the common field can be omitted, and multiple STAs can receive a PPDU (e.g., the data field of the PPDU) through the same frequency band. In a non - compressed mode that applies OFDMA, multiple users can receive a PPDU (e.g., the data field of the PPDU) through different frequency bands.

[0127] The number of user - specific fields can be determined based on the number of users. One user block field can include up to two user fields. Each user field can be associated with MU - MIMO allocation or can be associated with non - MU - MIMO allocation.

[0128] The common field can include CRC bits and tail bits, and the length of the CRC bits can be determined to be 4 bits, while the length of the tail bits can be determined to be 6 bits and set to 000000. The common field can include RU allocation information. The RU allocation information can include information about the positions of the RUs assigned to multiple users (i.e., multiple receiving STAs).

[0129] An RU can include multiple sub - carriers (or tones). When sending signals to multiple STAs based on OFDMA technology, RUs can be used. Additionally, even when sending signals to one STA, RUs can be defined. Resources can be allocated for non - traditional STF, non - traditional LTF, and data fields in units of RUs.

[0130] The RU of an applicable size can be defined according to the PPDU bandwidth. The RU can be defined identically or differently for the applied PPDU format (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.). For example, in the case of an 80 MHz PPDU, the RU layouts of the HE PPDU and the EHT PPDU can be different. The applicable RU size, the number of RUs, and the RU positions, the DC (direct current) subcarrier positions and number, the null subcarrier positions and number, the guard subcarrier positions and number, etc. for each PPDU bandwidth can be referred to as a tone plan. For example, the tone plan for high bandwidth can be defined in the form of multiple iterations of a low bandwidth tone plan.

[0131] RUs of various sizes can be defined as 26-tone RUs, 52-tone RUs, 106-tone RUs, 242-tone RUs, 484-tone RUs, 996-tone RUs, 2×996-tone RUs, 3×996-tone RUs, etc. An MRU (multi-RU) is different from multiple individual RUs and corresponds to a set of subcarriers composed of multiple RUs. For example, an MRU can be defined as 52 + 26 tones, 106 + 26 tones, 484 + 242 tones, 996 + 484 tones, 996 + 484 + 242 tones, 2×996 + 484 tones, 3×996 tones, or 3×996 + 484 tones. Additionally, the multiple RUs constituting an MRU can be continuous or non-continuous in the frequency domain.

[0132] The specific size of an RU can be reduced or extended. Therefore, the specific size (i.e., the number of corresponding tones) of each RU in this disclosure is illustrative rather than restrictive. Additionally, in this disclosure, within a predetermined bandwidth (e.g., 20 MHz, 40 MHz, 80 MHz, 160 MHz, 320 MHz...), the number of RUs can vary according to the RU size.

[0133] Figure 7 The name of each field in the PPDU format is exemplary, and the scope of this disclosure is not limited by these names. Additionally, the examples of this disclosure can be applied to Figure 7 the PPDU format shown in Figure 7 and new PPDU formats that exclude some fields and / or add some fields based on the

[0134] Target Wake-up Time (TWT)

[0135] TWT is a PS (power saving) technology that can improve the energy efficiency of non-AP STAs by defining a service period (SP) between the AP and the non-AP STA and sharing information about the SP to reduce medium contention.

[0136] A STA that executes requests / suggestions / requirements, etc. during the TWT establishment phase can be referred to as a TWT requesting STA. Additionally, an AP that responds to requests (such as acceptance / rejection) can be referred to as a TWT responding STA.

[0137] The establishment step can include a process of determining / defining the TWT request of the STA for the AP, the type of TWT operation to be performed, and the type of frames to be sent and received. TWT operations can be divided into individual TWT and broadcast TWT.

[0138] Figure 8 is a diagram for describing an example of an individual TWT operation to which the present disclosure can be applied.

[0139] Individual TWT is a mechanism in which an AP and a non-AP STA negotiate the wake-up / sleep state of the non-AP STA through the sending or receiving of TWT request / response frames and then exchange data.

[0140] In Figure 8 example, the AP and STA 1 can form a trigger-enabled TWT agreement through TWT request frames and TWT response frames.

[0141] Here, the method used by STA1 is a requested TWT method. When STA 1 sends a TWT request frame to the AP, STA 1 receives information for TWT operation from the AP through a TWT response frame.

[0142] On the other hand, STA2 that executes an unsolicited TWT method can receive information about the trigger-enabled TWT agreement configuration from the AP through an unsolicited TWT response.

[0143] Specifically, STA 2 can calculate the next TWT by adding a specific number to the current TWT value. During the trigger-enabled TWT SP, the AP can send a trigger frame to the STA. The trigger frame can notify the STA that the AP has buffered data. In response, STA 1 can notify the AP of its wake-up state by sending a PS poll frame. Additionally, STA 2 can notify the AP of its wake-up state by sending a QoS null frame. Here, the data frames sent by STA 1 and STA 2 can be frames in the TB PPDU format. The AP that has confirmed the states of STA 1 and STA 2 can send a DL MU PPDU to wake up the STA. When the corresponding TWT SP expires, STA 1 and STA 2 can switch to the sleep state.

[0144] Figure 9 is a diagram for describing an example of a broadcast TWT operation to which the present disclosure can be applied.

[0145] Broadcast TWT is a type of TWT in which a non-AP STA (or TWT-scheduled STA) obtains information about the target beacon transmission time (TBTT) and listen interval by sending and receiving TWT request / response frames using an AP (or a TWT-scheduled STA). Here, a negotiation operation for the TBTT can be performed. Based on this, the AP can define a frame that will contain the scheduling information of the TWT through the beacon frame.

[0146] In Figure 9 STA 1 performs a requested TWT operation, and STA 2 performs an unsolicited TWT operation. The AP can send a DL MU PPDU after checking the wake-up state of the STA through a trigger sent by the AP. This can be the same as the process for individual TWTs. In broadcast TWT, the trigger-enabled TWT SP including the beacon frame can be repeated multiple times at a specific interval.

[0147] The transmission of TWT information can be done through TWT information frames and TWT information elements. The TWT information frame is sent by the STA to request or convey information about the TWT agreement and is sent by one of the STAs in the existing TWT agreement. The action frame of the TWT information frame includes a TWT information field.

[0148] The TWT information field can include a 3-bit TWT stream identifier subfield, a 1-bit response request subfield, a 1-bit next TWT request subfield, a 2-bit next TWT subfield size subfield, a 1-bit full TWT subfield, and a 0 / 32 / 48 / 64-bit next TWT subfield.

[0149] Here, the TWT stream identifier subfield can be used to identify the stream that requested / provided the TWT information.

[0150] The response request subfield can indicate whether the sender of the frame including the TWT information field requests the transmission of a TWT information frame (which will be sent in response to the reception of the frame). To request that the receiver not send a TWT information frame in response to the reception of the frame, the response request subfield value can be set to 0. To request that the receiver send a TWT information frame in response to the reception of the frame, the response request subfield value can be set to 1.

[0151] To indicate a request for the transmission of a TWT information frame for the following TWT fields (where the length of the TWT information frame is not 0), the value of the next TWT subfield can be set to 1. Otherwise, the value of the next TWT subfield can be set to 0.

[0152] The next TWT sub - field size sub - field can indicate the size of the next TWT sub - field. When the size of the next TWT sub - field is 0 / 32 / 48 / 64 bits, the value of the next TWT sub - field size sub - field can be set to 0 / 1 / 2 / 3.

[0153] All TWT sub - field values can be set to 1 by HE STA, which can mean that the TWT information frame has realigned all TWTs. Otherwise, all TWT sub - field values can be set to 0.

[0154] Figure 10 is a diagram showing an example of the format of the TWT information element.

[0155] TWT elements can be sent and received by being included in beacons, probe responses, (re) association response frames, etc. TWT elements can include an element ID field, a length field, a control field, and a TWT parameter information field.

[0156] The control field of the TWT element has the same format regardless of individual TWTs and broadcast TWTs.

[0157] The NDP paging indication sub - field can have a value of 1 when the NDP paging field exists and a value of 0 when the NDP paging field does not exist.

[0158] The responder PM mode sub - field can indicate the power management (PM) mode.

[0159] The negotiation type sub - field can indicate whether the information included in the TWT element is about the negotiation of parameters for a broadcast TWT or an individual TWT or about the wake - up TBTT interval.

[0160] For example, if the value of the negotiation type sub - field is 0, the TWT sub - field is for the future start time of an individual TWT SP, and the TWT element contains a set of individual TWT parameters. This can correspond to an individual TWT negotiation between a TWT - requesting STA and a TWT - responding STA, or to an individual TWT advertisement by the TWT responder.

[0161] For example, if the value of the negotiation type sub - field is 1, the TWT sub - field is for the next TBTT time, and the TWT element contains a set of individual TWT parameters. This can correspond to the wake - up TBTT and the negotiation of the wake - up interval between a TWT - scheduled STA and a TWT - scheduled AP.

[0162] For example, if the value of the negotiation type subfield is 2, the TWT subfield is for the future broadcast TWT SP start time, and the TWT element includes one or more broadcast TWT parameter sets. This can correspond to providing broadcast TWT scheduling to the TWT-scheduled STAs by including the TWT element in a broadcast management frame sent by the TWT-scheduling AP.

[0163] For example, if the value of the negotiation type subfield is 3, the TWT subfield is for the future broadcast TWT SP start time, and the TWT element includes one or more broadcast TWT parameter sets. This can correspond to managing the membership of broadcast TWT scheduling by including the TWT element in a separately addressed management frame sent by either the TWT-scheduled STA or the TWT-scheduling AP.

[0164] If the TWT information frame disable subfield is set to 1, this indicates that the STA's reception of the TWT information frame is disabled; otherwise, it can be set to 0.

[0165] The wake duration unit subfield indicates the unit of the nominal minimum TWT wake duration field. When the unit is 256 us, the wake duration unit subfield can be set to 0, and when the unit is TU, the wake duration unit subfield can be set to 1. When it is not a HE / EHT STA, the wake duration unit subfield can be set to 0.

[0166] The most significant bit (MSB) of the negotiation type field can correspond to the broadcast field. If the broadcast field is 1, one or more broadcast TWT parameter sets can be included in the TWT element. If the broadcast field is 0, only one individual TWT parameter set can be included in the TWT element. A TWT element with the broadcast field set to 1 can be referred to as a broadcast TWT element.

[0167] In addition, Figure 10 A case where the reserved field consists of 2 bits is shown, but this is merely an example. For example, the TWT element can include a link ID bitmap presence field (e.g., 1 bit) and a reserved field (e.g., 1 bit).

[0168] For example, if the link ID bitmap presence field is set to 1, the link ID bitmap field is set to be present in the separate TWT parameter set field format to be described later, and if the link ID bitmap presence field is set to 0, the link ID bitmap field can be set to not be present in the separate TWT parameter set field format.

[0169] Figure 11 is a diagram for describing an example of the separate TWT parameter set field format. Figure 12It is a diagram for describing an example of the field format of a broadcast TWT parameter set.

[0170] The TWT parameter information field included in Figure 10 the TWT element can have different configurations according to a separate TWT or a broadcast TWT.

[0171] In the case of a separate TWT, the TWT parameter information field within the TWT element includes a single separate TWT parameter set field.

[0172] In the case of a broadcast TWT, the TWT parameter information field in the TWT element includes one or more broadcast TWT parameter set fields. Each broadcast TWT parameter set can include specific information about one broadcast TWT.

[0173] As Figure 11 and Figure 12 shown, the separate TWT parameter set field and the broadcast TWT parameter set field include common sub-fields.

[0174] The request type sub-field has the same size in the separate TWT parameter set field and the broadcast TWT parameter set field, but the detailed configuration can be different. It will be described later.

[0175] The target wake-up time sub-field indicates the start time of a future scheduled separate / broadcast TWT SP.

[0176] The nominal minimum TWT wake-up duration sub-field indicates the minimum unit for expecting the wake-up TWT to request the STA to complete the frame exchange associated with the TWT flow identifier during the TWT wake-up interval duration. Here, the TWT wake-up interval can mean the average time between consecutive TWT SPs expected by the TWT request STA.

[0177] The TWT wake-up interval mantissa sub-field is the binary value of the TWT wake-up interval value, which can be expressed in microseconds.

[0178] Referring to Figure 11 the TWT group assignment sub-field, the TWT channel, and the NDP paging sub-field are only included in the separate TWT parameter set field.

[0179] The TWT group assignment sub-field includes information about the TWT group to which the STA is assigned and provides it to the TWT request STA. The corresponding information can be used to calculate the TWT value within the TWT group. The TWT value of the STA can be equal to the zero-offset value and the TWT unit value multiplied by the TWT offset value.

[0180] Here, the TWT group information may include a TWT group ID subfield, a zero offset presence subfield, a group zero offset subfield, a TWT unit subfield, and a TWT offset subfield.

[0181] The TWT group ID subfield may indicate the identifier of the TWT group to which the requesting STA is assigned, and the TWT group may mean a group of STAs having TWT values within a specific interval of the TSF value. If the TWT group ID field value is set to 0, it may indicate the unique TWT group including all STAs of the BSS.

[0182] The zero offset presence subfield may indicate whether the group zero offset subfield exists. For example, if the zero offset presence subfield value is set to 1, it may indicate the existence of the group zero offset subfield. If the zero offset presence subfield value is set to 0, it may indicate the non - existence of the group zero offset subfield.

[0183] The group zero offset subfield is optional and may indicate the initial TWT value of the TWT group identified by the TWT group ID.

[0184] The TWT unit subfield may indicate the increment unit of the TWT value within the TWT group identified by the TWT group ID. For example, if the TWT unit time values are 32 μs, 256 μs, 1024 μs, 8.192 ms, 32.768 ms, and 262.144 ms respectively, the TWT unit subfield values may be expressed as 0, 1, 3, and 4 respectively.

[0185] The TWT offset subfield may indicate the position within the specified group of the STA corresponding to the RA of the frame including the TWT element.

[0186] The TWT channel subfield represents a bitmap indicating the allowed channels. When sent by the TWT - requesting STA, the TWT channel subfield may include a bitmap indicating the channels that the STA requests to be used as the temporary basic channel during the TWT SP. When sent by the TWT - responding STA, the TWT channel subfield may include a bitmap indicating the channels that allow the TWT request.

[0187] The NDP paging subfield is optional and may include the identifier of the STA being paged, information related to the maximum number of TWT wake - up intervals between NDP paging frames, etc.

[0188] Refer to Figure 12, the broadcast TWT info subfield is only included in the broadcast TWT parameter set field. The broadcast TWT info subfield may include 3 reserved bits, a 5-bit broadcast TWT identifier (ID) subfield, and an 8-bit broadcast TWT persistent subfield. The broadcast TWT identifier subfield indicates the broadcast ID of a specific broadcast TWT for which the STA requests to participate or provide TWT parameters according to the value of the TWT establishment command subfield of the TWT element. The broadcast TWT persistent subfield indicates the number of TBTTs scheduled on the schedule of the broadcast TWT.

[0189] Next, the specific configuration of the request type subfield will be described.

[0190] First, with reference to Figure 11 , the format of the request type subfield of the individual TWT parameter set field will be described.

[0191] The TWT request subfield can indicate whether it is a requesting STA or a responding STA. If the value is 1, this can indicate that it is a TWT requesting STA or a scheduling STA, and if the value is 0, this can indicate that it is a TWT responding STA or a scheduling AP.

[0192] The TWT establishment command subfield can indicate commands such as request, suggestion, requirement, acceptance, replacement, indication, rejection.

[0193] The trigger subfield indicates whether a trigger frame is used in the TWT SP. If the value is 1, trigger can be used, and if the value is 0, trigger may not be used.

[0194] The implicit subfield can indicate whether it is an implicit TWT or an explicit TWT. If the value is 1, this can indicate an implicit TWT, and if the value is 0, this can indicate an explicit TWT.

[0195] The flow type subfield can indicate the interaction type between the TWT requesting STA (or TWT scheduling STA) and the TWT responding STA (or TWT scheduling AP). If the value is 1, this can mean that in the advertised TWT: the STA sends a wake-up signal to the AP by sending a PS-poll or APSD (Automatic Power Save Delivery) trigger frame before the AP sends a frame other than the trigger frame to the STA. If the value is 0, this can mean an unadvertised TWT.

[0196] The TWT flow identifier subfield can include a 3-bit value that uniquely identifies specific information for the TWT request among other requests made between the same TWT requesting STA and TWT responding STA pair.

[0197] The TWT wake-up interval exponent subfield can set the TWT wake-up interval value in binary microseconds. In the case of a separate TWT, this can mean the interval between separate TWT SPs. The TWT wake-up interval of the requesting STA can be defined as [TWT wake-up interval mantissa * 2 * TWT wake-up interval exponent].

[0198] The TWT protection subfield can indicate whether to use the TWT protection mechanism. If the value is 1, the TXOP in the TWT SP can be initiated with the NAV protection mechanism (e.g., (MU)RTS / CTS or CTS-to-self frame), and if the value is 0, the NAV protection mechanism may not be applied.

[0199] Refer to Figure 12 , some subfields of the request type subfield of the broadcast TWT parameter set field are common with the subfields of the request type subfield of the separate TWT parameter set field, so their descriptions are omitted. The following describes only the subfields included in the broadcast TWT parameter set.

[0200] The last broadcast parameter set subfield indicates whether it is the last broadcast TWT parameter set. If the value is 1, this can indicate that it is the last broadcast TWT parameter set, and if the value is 0, it can indicate that there is a next broadcast TWT parameter set.

[0201] The broadcast TWT recommendation subfield can indicate a recommendation for the frame type sent by the AP during the broadcast TWT SP as values 1 - 7.

[0202] For example, when the broadcast TWT recommendation field value is set to 4, the corresponding broadcast TWT SP can be called an r-TWT SP. That is, the broadcast TWT parameter set with the broadcast TWT recommendation field value set to 4 can be called a restricted TWT parameter set. Here, during the r-TWT SP, the AP and the member r-TWT scheduled STAs can specify the transmission priority of QoS data frames (which are delay-sensitive services). And the broadcast TWT element that only includes the r-TWT parameter set field can be called a restricted TWT element.

[0203] The last bit of the request type subfield of the broadcast TWT parameter set field can be reserved.

[0204] As an example of the present disclosure, the broadcast TWT parameter set field can include a restricted TWT service information (info) subfield. As an example, as Figure 12 illustrated in, the TWT service information subfield can be after the broadcast TWT information field of the broadcast TWT parameter set field.

[0205] As an example of the present disclosure, as Figure 13As exemplified in (a) of, the broadcast TWT information subfield may include a restricted TWT service information presence subfield and a restricted TWT scheduling complete subfield.

[0206] The restricted TWT service information presence subfield and the restricted TWT scheduling complete subfield may be respectively set in the first bit (B0) and the second bit (B1) of the broadcast TWT information field as shown in Figure 12 shown.

[0207] For example, if the restricted TWT service information field exists in the broadcast TWT parameter set field, the value of the restricted TWT service information presence subfield of the restricted TWT parameter set field may be set to 1. Otherwise, the value of the restricted TWT service information presence subfield may be set to 0. For non-EHT STAs, the restricted TWT service information presence subfield may be reserved.

[0208] If the value of the restricted TWT scheduling complete subfield is set to 1, it may indicate that the r-TWT scheduling AP is less likely to accept requests from STAs in the BSS to establish new memberships in the scheduling. Otherwise, the value of the restricted TWT scheduling complete subfield may be set to 0.

[0209] If the restricted TWT parameter set field is carried in a TWT element in which the negotiation type subfield is set to 2 and the TWT element is sent by an EHT AP, the restricted TWT scheduling complete subfield may be valid.

[0210] If the value of the restricted TWT service information presence subfield of the broadcast TWT information subfield is set to 1, the restricted TWT service information field may exist in the restricted TWT parameter set field.

[0211] As Figure 13 exemplified in (b) of, the restricted TWT service information field may include a service information control subfield, a restricted TWT DL TID bitmap subfield, and a restricted TWT UL TID bitmap subfield.

[0212] As Figure 13 exemplified in (c) of, the service information control field may include a DL TID bitmap valid subfield and a UL TID bitmap valid subfield.

[0213] The DL TID bitmap valid subfield may be set to 1 to indicate that the restricted TWT DL TID bitmap field is valid. The DL TID bitmap valid subfield may be set to 0 to indicate that the DL services for all TIDs mapped to the DL of the link for which the r-TWT membership is established are identified as delay-sensitive services, and the restricted TWT DL TID bitmap field is reserved.

[0214] The UL TID bitmap valid subfield can be set to 1 to indicate that the restricted TWT UL TID bitmap field is valid. The UL TID bitmap valid subfield can be set to 0 to indicate that UL traffic for all TIDs mapped to the UL of a link for which r-TWT membership has been established is identified as delay-sensitive traffic and the restricted TWT UL TID bitmap field is reserved.

[0215] The restricted TWT DL TID bitmap subfield and the restricted TWT UL TID bitmap subfield can specify the TIDs of traffic flows identified as delay-sensitive in the DL direction and UL direction respectively by the r-TWT scheduling AP or the R-TWT scheduling STA.

[0216] A value of 1 at bit position k in the bitmap can indicate that TID k is classified as a delay-sensitive traffic flow. A value of 0 at bit position k in the bitmap can indicate that TID k is not classified as a delay-sensitive traffic flow.

[0217] Method for Supporting P2P Transmission of Delay-Sensitive Services

[0218] With the recent explosive growth of wired / wireless services, services sensitive to latency have also increased significantly. Services sensitive to latency include real-time audio / video transmission, and with the proliferation of multimedia devices, the need to support this in a wireless environment has increased. However, compared to a wired environment, many things need to be considered in a wireless environment to support latency-sensitive services. This is because the transmission speed in a wireless environment is lower than that in a wired environment, and interference problems from the surrounding environment must also be considered. Specifically, in a wireless LAN system, multiple STAs must equally compete for medium occupancy in the ISM (Industrial, Scientific, Medical) band, so it is relatively more difficult to support latency-sensitive services compared to a cellular communication network based on radio resources scheduled by a central base station. This disclosure describes a new method for supporting latency-sensitive services in a wireless LAN system.

[0219] In addition, in this disclosure, a non-AP STA that supports the transmission of latency-sensitive data can be referred to as a low-latency STA. And data other than latency-sensitive data can be referred to as regular data.

[0220] Here, a general STA can support the transmission of delay-sensitive services / data, and a low-latency STA can support the transmission of general services / data.

[0221] To allocate time for P2P data transmission and reception between STAs in a wireless LAN system, the AP can send a MU (Multi-User)-RTS (Request To Send) TXS trigger frame to the corresponding STA. In addition, each STA can be allocated an r-TWT SP (which is the time for ensuring the transmission and reception of delay-sensitive services) from the AP.

[0222] In a basic wireless communication system, a process and related protocol for transmitting and receiving delay-sensitive services in a peer-to-peer (P2P) manner within an r-TWT SP have not been defined. Therefore, there is a need for a method to efficiently transmit delay-sensitive services.

[0223] In the following, a method for requesting and allocating an r-TWT SP capable of P2P transmission to facilitate the allocation of time for transmitting and receiving delay-sensitive services between STAs is described.

[0224] Figure 14 is a flowchart for describing the operation of a first STA according to an embodiment of the present disclosure.

[0225] The first STA may send a first frame including a first field for requesting P2P data communication within an r-TWT to an AP.

[0226] Specifically, the first STA may send a first frame (e.g., a TWT setup frame including a broadcast TWT parameter set field) to the AP to request the establishment of a TWT service period (SP).

[0227] Here, the first field (e.g., P2P in the restricted TWT SP subfield) may be included in a restricted TWT service information control subfield included in a restricted TWT service information subfield of the broadcast TWT parameter set field.

[0228] For example, the first field may be set on one of the bits from the third bit (B2) to the eighth bit (B7) of the TWT service information control subfield.

[0229] The first STA may receive a third frame from the AP in response to the first frame. That is, the first STA may receive a third frame from the AP, which is a response frame to the establishment request of the TWT SP.

[0230] The third frame may include a TWT setup command field for accepting the TWT request according to the first frame and the first field. That is, the third frame may include the same first field as the first field included in the first frame.

[0231] Here, the first field included in the third frame may also be set on the restricted TWT service information control subfield included in the restricted service information subfield of the broadcast TWT parameter set field. In addition, the value of the TWT setup command field may be set to 4, and the values of the first field included in the first frame and the first field included in the third frame may both be set to 1.

[0232] The first STA may receive, from the AP, a second frame including first information related to the time for P2P data communication (S1420).

[0233] For example, the second frame may be a multi-user (MU) request to send (RTS) TXS trigger frame. The MU RTS TXS frame may be sent from the AP to the first STA within the r-TWT SP, and the r-TWT SP may be set based on the first frame and the third frame.

[0234] Also, the first information may include information related to the time allocated for P2P data communication within the r-TWT SP. The time allocated by the first information may be within the r-TWT SP.

[0235] The first STA may perform P2P data communication with the second STA during the time allocated by the first information (S1430).

[0236] For example, delay-sensitive traffic may be sent and received between the first STA and the second STA via P2P data communication. However, this is merely one implementation, and general data may also be sent and received between the first STA and the second STA via P2P data communication.

[0237] Here, after the time for P2P data communication has elapsed, the first STA may perform communication with the AP within the r-TWT SP (e.g., delay-sensitive traffic sending / receiving operations, etc.). That is, the first STA may perform communication with the AP until the time for P2P data communication has elapsed and the r-TWT SP has expired.

[0238] In Figure 14 the example described, the method performed by the first STA may be performed by Figure 1 the first device (100). For example, Figure 14 one or more processors (102) of the first device (100) may send, via one or more transceivers (106), a first frame including a first field for requesting P2P data communication within the r-TWT to the AP. One or more processors (102) may receive, via one or more transceivers (106), a second frame including first information related to the time for P2P data communication from the AP. One or more processors (102) may perform communication with the first STA within the r-TWT SP after the time for P2P data communication has elapsed.

[0239] In addition, one or more memories (104) of the first device (100) may store instructions for performing the method described in Figure 14 the example when executed by one or more processors (102).

[0240] Figure 15 This is a diagram for describing the operation of an AP according to an embodiment of the present disclosure.

[0241] The AP may receive a first frame including a first field for requesting P2P data communication within an r-TWT from a first STA (S1510).

[0242] The AP may request the TWT SP to send a third frame to the first STA in response to the first frame.

[0243] As described above, the third frame may include a TWT establishment command field for approving the TWT request according to the first frame and the first field. That is, the third frame may include the same first field as the first field included in the first frame.

[0244] The AP may send a second frame including first information related to the time for P2P data communication to the first STA (S1520).

[0245] That is, the AP may allocate the time for performing P2P data communication within the r-TWT SP to the first STA through the second frame.

[0246] The AP may perform communication with the first STA within the r-TWT SP after the time for P2P data communication has elapsed (S1530).

[0247] That is, the AP may communicate with the first STA until the time for P2P data communication has elapsed and the r-TWT SP expires.

[0248] Figure 15 The method performed by the AP described in the example of Figure 1 may be performed by a second device (200) of Figure 1 For example, one or more processors (202) of the second device (200) of

[0249] may receive a first frame including a first field for requesting P2P data communication within an r-TWT from a first STA through one or more transceivers (206). One or more processors (202) may send a second frame including first information related to the time for P2P data communication to the first STA through one or more transceivers (206). One or more processors (202) may perform communication with the first STA within the r-TWT SP after the time for P2P data communication has elapsed. Figure 15 In addition, one or more memories (204) of the second device (200) may store instructions for performing the method described in the example of

[0250] In the following, a P2P transmission procedure and TWT elements for performing P2P transmission within an r-TWT SP are specifically described.

[0251] Embodiment 1

[0252] The STA can request and / or respond to P2P data transmission and reception during the r-TWT SP through a new field in the TWT element. The new field may be referred to as the P2P (P2P in a restricted TWT SP) (sub) field in the r-TWT SP, but is not limited thereto, and the name of the new field can be changed in various ways. In addition, the STA in the present disclosure can include a non-AP STA and an AP STA.

[0253] In the TWT negotiation phase, the TWT request STA can request the TWT response STA to perform (some or all) data transmission and reception in a P2P manner (i.e., P2P communication) during the r-TWT SP allocated by the TWT response STA.

[0254] When the TWT request STA requests to perform data transmission and reception in a P2P manner during the r-TWT SP, the value of the P2P sub-field in the r-TWT SP can be set to 1. When the value of the P2P sub-field in the r-TWT SP is set to 1, this can mean that the STA (e.g., AP) is requested to allocate time for P2P data transmission and reception within the r-TWT SP allocated through TWT negotiation. When the value of the P2P sub-field in the r-TWT SP is set to 0, this can mean that the STA (e.g., AP) is not requested to allocate time for P2P data transmission and reception within the r-TWT SP allocated through TWT negotiation.

[0255] However, even if the TWT request STA does not request / request time allocation for P2P through the value of the P2P sub-field in the r-TWT SP, the AP can allocate / request time for P2P data transmission and reception in the r-TWT SP based on the P2P-related information among the information related to delay-sensitive services pre-exchanged with the STA.

[0256] When approving the request of the TWT request STA (i.e., the request related to P2P transmission within the r-TWT SP), the TWT response STA can set a value corresponding to the request approval in the TWT establishment command field. Then, the TWT response STA can set the value of the P2P sub-field within the r-TWT SP to be the same as the value of the P2P sub-field within the r-TWT SP in the TWT element sent by the TWT request STA, and send it to the TWT request STA.

[0257] When rejecting a request from a TWT-requesting STA (i.e., a request related to P2P transmission within the r-TWT SP), the TWT-response STA can set a value corresponding to the request rejection in the TWT establishment command field. Then, the TWT-response STA can set the value of the P2P subfield within the r-TWT SP to 0 and send it to the TWT-requesting STA.

[0258] Embodiment 2

[0259] Embodiment 2 relates to a method for allocating time for P2P data transmission within the r-TWT SP.

[0260] As an embodiment of the present disclosure, Figure 16 the following process is illustrated: The TWT-requesting STA uses the P2P subfield in the r-TWT SP to request P2P data transmission and reception in the r-TWT SP, and then receives the time allocated for P2P data transmission and reception from the TWT-response STA.

[0261] As Figure 16 illustrated, the RSP (Restricted Support) STA1 can set the value of the P2P subfield in the r-TWT SP included in the TWT element to 1 and then send it to the AP. Here, the RSP STA 1 means the TWT-requesting STA and can be a non-AP STA or an AP. Additionally, the P2P subfield in the r-TWT SP can be included in the frame for requesting TWT.

[0262] By setting the value of the P2P subfield in the r-TWT SP to 1, the RSP STA 1 can request the AP to perform P2P data transmission and reception with another RSP STA (e.g., RSP STA 2) in the r-TWT SP.

[0263] The AP can set the value of the TWT establishment command field to 4 and set the value of the P2P subfield in the r-TWT SP to 1 (i.e., the same value as the value of the P2P subfield in the r-TWT SP set by the RSP STA 1). The AP can respond to the request of the RSP STA 1 by sending the TWT establishment command field set to 4 and the value of the P2P subfield in the r-TWT SP set to 1 to the RSPSTA 1.

[0264] Therefore, an r-TWT SP from the AP can be allocated to the RSP STA 1. After the start of the r-TWT SP, the AP can allocate time for P2P communication via a MU-RTS TXS trigger frame. The AP can send a MU-RTS TXS trigger frame to the RSP STA 1 immediately after the start of the r-TWT SP, but is not limited thereto. The AP can send a MU-RTS TXS trigger frame to the RSP STA 1 after a predetermined time after the start of the r-TWT SP.

[0265] As Figure 16 illustrated, the RSP STA1 can perform P2P data transmission and reception operations with the RSP STA 2 during the time allocated by the MU-RTS TXS trigger frame. Here, the P2P data can be delay-sensitive data, but is not limited thereto.

[0266] After the time allocated by the MU-RTS TXS trigger frame has elapsed, the RSP STA 1 can send and receive data with the AP.

[0267] Embodiment 3

[0268] Embodiment 3 relates to the configuration of a field that sets a P2P subfield within the r-TWT SP. That is, Embodiment 3 relates to a field including a P2P subfield indicating P2P data transmission and reception within the r-TWT SP.

[0269] As an example of the present disclosure, as Figure 17 illustrated in (a) of, the P2P subfield within the r-TWT SP can be included in the broadcast TWT information subfield.

[0270] For example, one bit of the reserved bits included in the broadcast TWT information subfield of the broadcast TWT parameter set field can be used to set the P2P subfield in the r-TWT SP.

[0271] As another example of the present disclosure, as Figure 17 illustrated in (b) of, the P2P subfield in the r-TWT SP can be set on the traffic information control field included in the restricted TWT traffic information subfield of the broadcast TWT parameter set field.

[0272] For example, a 1-octet traffic information control field can exist in the restricted TWT traffic information field. One bit of the 6 reserved bits of the traffic information control field of the restricted TWT traffic information field can be used to set the P2P subfield in the r-TWT SP.

[0273] The above-described embodiments combine the elements and features of the present disclosure in a predetermined form. Unless explicitly stated otherwise, each element or feature should be considered optional. Each element or feature can be implemented in a form that does not combine with other elements or features. Additionally, embodiments of the present disclosure can include combinations of some elements and / or features. The order of operations described in the embodiments of the present disclosure can be changed. Some elements or features of one embodiment can be included in other embodiments, or can be replaced with corresponding elements or features of other embodiments. Apparently, embodiments can include combinations of claims that do not have an explicit citation relationship in the claims, or can be included as new claims through amendment after filing the application.

[0274] It is clear to those skilled in the relevant art that the present disclosure can be implemented in other specific forms without exceeding the essential features of the present disclosure. Therefore, the above detailed description should not be construed restrictively in every aspect, but should be considered illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present disclosure are included within the scope of the present disclosure.

[0275] The scope of the present disclosure includes software or machine-executable commands (e.g., operating systems, application programs, firmware, programs, etc.) that perform operations according to the methods of various embodiments in a device or computer, and non-transitory computer-readable media that enable such software or commands to be stored and executable in the device or computer. Commands that can be used to program a processing system for performing the features described in the present disclosure can be stored in a storage medium or a computer-readable storage medium, and the features described in the present disclosure can be implemented by using a computer program product including such a storage medium. The storage medium can include high-speed random access memories, such as DRAM, SRAM, DDR RAM, or other random access solid-state storage devices, but is not limited thereto, and it can include non-volatile memories, such as one or more disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory optionally includes one or more storage devices located remotely from the processor. The memory, or alternatively, the non-volatile memory device in the memory, includes a non-transitory computer-readable storage medium. The features described in the present disclosure can be stored in any kind of machine-readable medium to control the hardware of the processing system, and can be integrated into software and / or firmware that allows the processing system to interact with other mechanisms using the results from the embodiments of the present disclosure. Such software or firmware can include application code, device drivers, operating systems, and execution environments / containers, but is not limited thereto.

[0276] Industrial Applicability

[0277] The method proposed by the present disclosure has been described by way of example with respect to applications in IEEE 802.11-based systems, but the method proposed by the present disclosure can be applied to various wireless LANs or wireless communication systems other than IEEE 802.11-based systems.

Claims

1. A method performed by a first station STA in a wireless LAN system, the method comprising the steps of: Sending a first frame including a first field for requesting peer-to-peer P2P data communication within a restricted target wake-up time r-TWT to an access point AP; Receiving, from the AP, a second frame including first information related to the time for P2P data communication; And Performing the P2P data communication with a second STA during the time allocated by the first information, wherein the time allocated by the first information is within an r-TWT service period SP.

2. The method according to claim 1, wherein The first field is included in a restricted TWT service information control sub-field included in a restricted TWT service information info sub-field of a broadcast TWT parameter set field.

3. The method according to claim 2, wherein The first field is set on one of the bits from the third bit B2 to the eighth bit B7 of the TWT service information control sub-field.

4. The method according to claim 2, wherein The first frame is a TWT setup frame including the broadcast TWT parameter set, and The second frame is a multi-user MU request-to-send RTS TXS trigger frame.

5. The method according to claim 1, wherein Receiving, from the AP, a third frame in response to the first frame, and The third frame includes a TWT setup command field for accepting a TWT request according to the first frame and the first field.

6. The method according to claim 5, wherein The value of the TWT setup command field is set to 4, and The value of each of the first field included in the first frame and the first field included in the third frame is set to 1.

7. The method according to claim 5, wherein The r-TWT SP is set based on the first frame and the third frame, and The MU RTS trigger frame is received from the AP within the r-TWT SP.

8. The method according to claim 1, wherein Through the P2P data communication, delay-sensitive services are received and sent between the first STA and the second STA.

9. The method according to claim 1, wherein After the time for the P2P data communication has elapsed, communication with the AP is performed within the r-TWT SP.

10. A first station STA performing operations in a wireless LAN system, the first STA comprising: At least one transceiver; And At least one processor, the at least one processor being connected to the at least one transceiver, wherein the at least one processor is configured to: Send, through the at least one transceiver, a first frame including a first field for requesting peer-to-peer P2P data communication within a restricted target wake-up time r-TWT to an access point AP; Receive, through the at least one transceiver, from the AP, a second frame including first information related to the time for P2P data communication; and Perform the P2P data communication with a second STA via the at least one transceiver during the time allocated by the first information, wherein the time allocated by the first information is within an r-TWT service period SP.

11. A method performed by an access point AP in a wireless LAN system, the method comprising the steps of: Receiving, from a first station STA, a first frame including a first field for requesting peer-to-peer P2P data communication within a restricted target wake time r-TWT; Sending, to the first STA, a second frame including first information related to the time for P2P data communication; And Performing communication with the first STA within an r-TWT service period SP after the time for P2P data communication has elapsed, wherein the time allocated by the first information is within an r-TWT service period SP.

12. An access point AP operating in a wireless LAN system, the AP comprising: At least one transceiver; And At least one processor, the at least one processor being connected to the at least one transceiver, wherein the at least one processor is configured to: Receive, via the at least one transceiver, from a first station STA, a first frame including a first field for requesting peer-to-peer P2P data communication within a restricted target wake time r-TWT; Send, via the at least one transceiver, to the first STA, a second frame including first information related to the time for P2P data communication; and Perform communication with the first STA within an r-TWT service period SP after the time for P2P data communication has elapsed, wherein the time allocated by the first information is within an r-TWT service period SP.

13. A processing device configured to control a first station STA in a wireless LAN system, the processing device comprising: At least one processor; And At least one computer memory, the at least one computer memory being operatively coupled to the at least one processor and storing instructions for performing operations when executed by the at least one processor; The operations include: Sending to an access point AP a first frame including a first field for requesting peer-to-peer P2P data communication within a restricted target wake time r-TWT; Receiving from the AP a second frame including first information related to the time for P2P data communication; and Performing the P2P data communication with a second STA during the time allocated by the first information, wherein the time allocated by the first information is within an r-TWT service period SP.

14. At least one non-transitory computer-readable medium storing at least one instruction, Based on which, when executed by at least one processor, is for controlling a device for performing communication in a wireless LAN system: Sending to an access point AP a first frame including a first field for requesting peer-to-peer P2P data communication within a restricted target wake time r-TWT; Receive a second frame including first information related to a time for P2P data communication from the AP; and Perform the P2P data communication with a second STA during the time allocated by the first information, Among them, The time allocated by the first information is within an r-TWT service period SP.

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