WO2025147004A1 - Method and device for relay operation in wireless lan system - Google Patents

Abstract

A method and device for a relay operation in a wireless LAN system are disclosed. A method according to one embodiment of the present disclosure may comprise: a step in which a first STA receives a trigger frame from an AP, wherein the trigger frame includes time information for a time interval set for a relay operation within a TXOP acquired by the AP; a step in which the first STA receives data for a second STA from the AP within the time interval; and a step in which the first STA transmits the data to the second STA within the time interval.

Description

Method and device for relay operation in wireless LAN system

The present disclosure relates to a method and device for relay operation in a Wireless Local Area Network (WLAN) system.

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

In order to provide a more enhanced wireless communication environment, improved technologies for Extremely High Throughput (EHT) are being discussed. For example, technologies for MIMO (Multiple Input Multiple Output) and multi-access point (AP) coordination that support increased bandwidth, efficient utilization of multiple bands, and increased spatial streams are being studied, and in particular, various technologies are being studied to support low latency or real-time traffic. Furthermore, new technologies are being discussed to support ultra-high reliability (UHR), including improvements or extensions of EHT technologies.

The technical problem of the present disclosure is to provide a method and device for sharing transmission opportunity (TXOP) and determining bandwidth for relay operation.

The technical problems to be achieved in the present disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

A method according to one aspect of the present disclosure may include: receiving, by a first station (STA), a trigger frame from an access point (AP), the trigger frame including time information for a time interval set for a relay operation within a transmission opportunity (TXOP) acquired by the AP; receiving, by the first STA, data for a second STA from the AP within the time interval; and transmitting, by the first STA, the data to the second STA within the time interval.

A method according to an additional aspect of the present disclosure may include: transmitting, by an access point (AP), a trigger frame to a first station (STA), the trigger frame including time information for a time interval for a relay operation within a transmission opportunity (TXOP) obtained by the AP; and transmitting, by the AP, data for a second STA to the first STA within the time interval for the relay operation.

According to the present disclosure, it is possible to protect signals/data transmitted and received through relay transmission, and reduce interference during relay communication for a hidden STA from an AP.

In addition, according to the present disclosure, wireless communication efficiency can be improved as the coverage of the AP is expanded through relay operation.

The effects obtainable from the present disclosure are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure belongs from the description below.

The accompanying drawings, which are incorporated in and are incorporated in and are intended to aid in understanding the present disclosure, provide embodiments of the present disclosure and together with the detailed description, describe the technical features of the present disclosure.

FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

FIG. 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

FIG. 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

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

FIG. 6 is a drawing for explaining an example of a frame structure used in a wireless LAN system to which the present disclosure can be applied.

FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

FIG. 8 is a diagram showing an exemplary format of a trigger frame to which the present disclosure can be applied.

FIG. 9 is a diagram showing the format of a common information field in a trigger frame to which the present disclosure can be applied.

FIG. 10 illustrates a TXOP sharing procedure in a wireless LAN system to which the present disclosure can be applied.

FIG. 11 illustrates the user information field format of an MU-RTS TXS trigger frame to which the present disclosure can be applied.

FIG. 12 is a diagram exemplifying range expansion using a relay in a wireless LAN system to which the present disclosure can be applied.

FIG. 13 is a diagram illustrating a procedure for TXOP sharing and bandwidth determination for relay communication according to one embodiment of the present disclosure.

FIG. 14 is a diagram illustrating a procedure for TXOP sharing and bandwidth determination for relay communication according to one embodiment of the present disclosure.

FIG. 15 is a diagram illustrating a procedure for TXOP sharing and bandwidth determination for relay communication according to one embodiment of the present disclosure.

FIG. 16 is a diagram illustrating a procedure for TXOP sharing and bandwidth determination for relay communication according to one embodiment of the present disclosure.

FIG. 17 illustrates the operation of a first station for a method for relay operation according to one embodiment of the present disclosure.

FIG. 18 illustrates the operation of an access point for a method for relay operation according to one embodiment of the present disclosure.

Hereinafter, preferred embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description set forth below together with the accompanying drawings is intended to explain exemplary embodiments of the present disclosure and is not intended to represent the only embodiments in which the present disclosure may be practiced. The following detailed description includes specific details in order to provide a thorough understanding of the present disclosure. However, one of ordinary skill in the art will appreciate that the present disclosure may be practiced without these specific details.

In some cases, to avoid obscuring the concepts of the present disclosure, well-known structures and devices may be omitted or illustrated in block diagram format focusing on the core functions of each structure and device.

In the present disclosure, when a component is said to be "connected", "coupled" or "connected" to another component, this may include not only a direct connection relationship, but also an indirect connection relationship in which another component exists between them. Also, the terms "comprises" or "has" in the present disclosure specify the presence of the mentioned features, steps, operations, elements and/or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components and/or groups thereof.

In this disclosure, the terms “first,” “second,” etc. are used only to distinguish one component from other components and are not used to limit the components, and do not limit the order or importance among the components unless specifically stated otherwise. Accordingly, within the scope of this disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and similarly, a second component in one embodiment may be referred to as a first component in another embodiment.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the claims. As used in the description of the embodiments and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly dictates otherwise. The term "and/or" as used herein may refer to one of the associated enumerated items or is meant to refer to and encompass any and all possible combinations of two or more of them. Furthermore, the word "/" used between words in this disclosure has the same meaning as "and/or" unless otherwise stated.

The examples of the present disclosure can be applied to various wireless communication systems. For example, the examples of the present disclosure can be applied to a wireless LAN system. For example, the examples of the present disclosure can be applied to a wireless LAN based on IEEE 802.11a/g/n/ac/ax/be standards. Furthermore, the examples of the present disclosure can be applied to a wireless LAN based on a newly proposed IEEE 802.11bn (or UHR) standard. Additionally, the examples of the present disclosure can be applied to a wireless LAN based on a next-generation standard after IEEE 802.11bn. In addition, the examples of the present disclosure can be applied to a cellular wireless communication system. For example, the examples of the present disclosure can be applied to a cellular wireless communication system based on a Long Term Evolution (LTE) series technology of the 3rd Generation Partnership Project (3GPP) standard and a New Radio (5G NR) series technology.

Below, technical features to which examples of the present disclosure can be applied are described.

FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

The first device (100) and the second device (200) illustrated in FIG. 1 may be replaced with various terms such as a terminal, a wireless device, a Wireless Transmit Receive Unit (WTRU), a User Equipment (UE), a Mobile Station (MS), a user terminal (UT), a Mobile Subscriber Station (MSS), a Mobile Subscriber Unit (MSS), a Subscriber Station (SS), an Advanced Mobile Station (AMS), a Wireless terminal (WT), or simply a user. In addition, the first device (100) and the second device (200) may be replaced with various terms such as an Access Point (AP), a Base Station (BS), a fixed station, a Node B, a base transceiver system (BTS), a network, an Artificial Intelligence (AI) system, a road side unit (RSU), a repeater, a router, a relay, a gateway, etc.

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

Referring to FIG. 1, the first device (100) and the second device (200) can transmit and receive wireless signals through various wireless LAN technologies (e.g., IEEE 802.11 series). The first device (100) and the second device (200) can include interfaces for a medium access control (MAC) layer and a physical layer (PHY) that follow the regulations of the IEEE 802.11 standard.

In addition, the first device (100) and the second device (200) may additionally support various communication standards (for example, standards of 3GPP LTE series, 5G NR series, etc.) other than wireless LAN technology. In addition, the device of the present disclosure may be implemented as various devices such as a mobile phone, a vehicle, a personal computer, an Augmented Reality (AR) device, and a Virtual Reality (VR) device. In addition, the STA of the present specification may support various communication services such as a voice call, a video call, a data communication, autonomous driving, MTC (Machine-Type Communication), M2M (Machine-to-Machine), D2D (Device-to-Device), and IoT (Internet-of-Things).

A first device (100) includes 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) controls the memories (104) and/or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed in this disclosure. For example, the processor (102) may process information in the memory (104) to generate first information/signal, and then transmit a wireless signal including the first information/signal via the transceiver (106). Additionally, the processor (102) may receive a wireless signal including second information/signal via the transceiver (106), and then store information obtained from signal processing of the second information/signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software codes including instructions for performing the descriptions, functions, procedures, proposals, methods, and/or operation flowcharts disclosed in the present disclosure. Here, the processor (102) and the memory (104) may be part of a communication modem/circuit/chip designed to implement a wireless LAN technology (e.g., 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 interchangeably with an RF (Radio Frequency) unit. In the present disclosure, a device may also mean a communication modem/circuit/chip.

The second device (200) includes one or more processors (202), 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 be configured to control the memories (204) and/or the transceivers (206), and implement the descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed in this disclosure. For example, the processor (202) may process information in the memory (204) to generate third information/signal, and then transmit a wireless signal including the third information/signal via the transceiver (206). Additionally, the processor (202) may receive a wireless signal including fourth information/signal via the transceiver (206), and then store information obtained from signal processing of the fourth information/signal 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 perform some or all of the processes controlled by the processor (202), or may store software codes including instructions for performing the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in the present disclosure. Here, the processor (202) and the memory (204) may be part of a communication modem/circuit/chip designed to implement a wireless LAN technology (e.g., IEEE 802.11 series). The transceiver (206) may be connected to the processor (202) and may transmit and/or receive wireless signals via one or more antennas (208). The transceiver (206) may include a transmitter and/or a receiver. The transceiver (206) may be used interchangeably with an RF unit. In the present disclosure, a device may also mean a communication modem/circuit/chip.

Hereinafter, hardware elements of the device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and/or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this disclosure. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and/or operational flowcharts disclosed in this disclosure. One or more processors (102, 202) can generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, suggestions and/or methodologies disclosed in this disclosure, and provide the signals to one or more transceivers (106, 206). One or more processors (102, 202) can receive signals (e.g., baseband signals) from one or more transceivers (106, 206) and obtain PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in this disclosure.

The one or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. The one or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in the one or more processors (102, 202). The descriptions, functions, procedures, suggestions, methods, and/or operational flowcharts disclosed in this disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in this disclosure may be implemented using firmware or software configured to perform one or more of the following: included in one or more processors (102, 202), or stored in one or more memories (104, 204) and driven by one or more of the processors (102, 202). The descriptions, functions, procedures, suggestions, methods and/or operational flowcharts disclosed in this disclosure may be implemented using firmware or software in the form of codes, instructions and/or sets of instructions.

One or more memories (104, 204) may be coupled to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and/or commands. The one or more memories (104, 204) may be comprised of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer readable storage media, and/or combinations thereof. The one or more memories (104, 204) may be located internally and/or externally to the one or more processors (102, 202). Additionally, the one or more memories (104, 204) may be coupled to the one or more processors (102, 202) via various technologies, such as wired or wireless connections.

One or more transceivers (106, 206) can transmit user data, control information, wireless signals/channels, etc., as mentioned in the methods and/or flowcharts of the present disclosure, to one or more other devices. One or more transceivers (106, 206) can receive user data, control information, wireless signals/channels, etc., as mentioned in the descriptions, functions, procedures, suggestions, methods and/or flowcharts of the present disclosure, from one or more other devices. For example, one or more transceivers (106, 206) can be coupled to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. 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 coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals/channels, and the like, as described in the description, function, procedure, proposal, method, and/or operational flowchart, etc. disclosed in this 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 received user data, control information, wireless signals/channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals/channels, etc. using one or more processors (102, 202). One or more transceivers (106, 206) may convert processed user data, control information, wireless signals/channels, etc. from baseband signals to RF band signals using one or more processors (102, 202). For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and/or filter.

For example, one of the STAs (100, 200) may perform the intended operation of an AP, and the other of the STAs (100, 200) may perform the intended operation of a non-AP STA. For example, the transceivers (106, 206) of FIG. 1 may perform transmission and reception operations of signals (e.g., packets or PPDUs (Physical layer Protocol Data Units) according to IEEE 802.11a/b/g/n/ac/ax/be/bn, etc.). In addition, in the present disclosure, operations of various STAs generating transmission and reception signals or performing data processing or calculations in advance for transmission and reception signals may be performed in the processors (102, 202) of FIG. 1. For example, an example of an operation for generating a transmit/receive signal or performing data processing or calculation in advance for a transmit/receive signal may include: 1) an operation for determining/acquiring/configuring/computing/decoding/encoding bit information of a field (SIG (signal), STF (short training field), LTF (long training field), Data, etc.) included in a PPDU, 2) an operation for determining/configuring/acquiring time resources or frequency resources (e.g., subcarrier resources) used for the fields (SIG, STF, LTF, Data, etc.) included in a PPDU, 3) an operation for determining/configuring/acquiring specific sequences (e.g., pilot sequences, STF/LTF sequences, extra sequences applied to SIG) used for the fields (SIG, STF, LTF, Data, etc.) included in a PPDU, 4) a power control operation and/or a power saving operation applied to an STA, 5) an operation related to determining/acquiring/configuring/computing/decoding/encoding an ACK signal, etc. In addition, in the examples below, various information (e.g., information related to fields/subfields/control fields/parameters/power, etc.) used by various STAs for determining/acquiring/configuring/computing/decoding/encoding transmission/reception signals can be stored in the memory (104, 204) of FIG. 1.

Hereinafter, downlink (DL) means a link for communication from an AP STA to a non-AP STA, and downlink PPDU/packet/signal, etc. can be transmitted and received through the downlink. In downlink communication, a transmitter may be part of an AP STA, and a receiver may be part of a non-AP STA. Uplink (UL) means a link for communication from a non-AP STA to an AP STA, and uplink PPDU/packet/signal, etc. can be transmitted and received through the uplink. In uplink communication, a transmitter may be part of a non-AP STA, and a receiver may be part of an AP STA.

FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

The structure of a wireless LAN system can be composed of multiple components. A wireless LAN supporting transparent STA mobility to a higher layer can be provided through the interaction of multiple components. A BSS (Basic Service Set) corresponds to a basic configuration block of a wireless LAN. FIG. 2 illustrates an example in which two BSSs (BSS1 and BSS2) exist and two STAs are included as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). An ellipse representing a BSS in FIG. 2 can also be understood as representing a coverage area in which STAs included in the corresponding BSS maintain communication. This area can be referred to as a BSA (Basic Service Area). If an STA moves out of the BSA, it cannot directly communicate with other STAs within the corresponding BSA.

If we do not consider the DS illustrated in Fig. 2, the most basic type of BSS in a wireless LAN is an independent BSS (IBSS). For example, an IBSS can have a minimal form consisting of only two STAs. For example, assuming that other components are omitted, BSS1 consisting of only STA1 and STA2 or BSS2 consisting of only STA3 and STA4 can be representative examples of an IBSS, respectively. This configuration is possible when STAs can communicate directly without an AP. In addition, in this type of wireless LAN, a LAN can be configured when needed rather than being planned in advance, and this can be called an ad-hoc network. Since an IBSS does not include an AP, there is no centralized management entity that performs management functions. That is, in an IBSS, STAs are managed in a distributed manner. In IBSS, all STAs can be mobile STAs, and access to distributed systems (DS) is not permitted, forming a self-contained network.

The membership of an STA in a BSS can be dynamically changed by the STA turning on or off, the STA entering or leaving the BSS area, etc. To become a member of a BSS, an STA can join the BSS using a synchronization process. In order to access all services of the BSS infrastructure, an STA must be associated with a BSS. This association can be dynamically established and may include the use of a Distribution System Service (DSS).

In wireless LANs, the direct STA-to-STA distance may be limited by the PHY performance. In some cases, this distance limitation may be sufficient, but in some cases, communication between STAs over longer distances may be required. To support extended coverage, a distributed system (DS) may be configured.

DS refers to a structure in which BSSs are interconnected. Specifically, a BSS may exist as an extended component of a network composed of multiple BSSs, as shown in FIG. 2. DS is a logical concept and can be specified by the characteristics of a distributed system medium (DSM). In this regard, a wireless medium (WM) and a DSM can be logically distinguished. Each logical medium is used for a different purpose and is used by different components. These media are neither limited to being the same nor limited to being different. In this way, the flexibility of a wireless LAN structure (DS structure or other network structure) can be explained in that multiple media are logically different. In other words, a wireless LAN structure can be implemented in various ways, and each wireless LAN structure can be independently specified by the physical characteristics of each implementation example.

A DS can support mobile devices by providing seamless integration of multiple BSSs and providing logical services necessary to handle addresses to destinations. In addition, a DS can further include a component called a portal that acts as a bridge for connecting wireless LANs to other networks (e.g., IEEE 802.X).

An AP is an entity that enables access to a DS through a WM for associated non-AP STAs, and also has the functionality of an STA. Data movement between a BSS and a DS can be performed through an AP. For example, STA2 and STA3 illustrated in FIG. 2 have the functionality of an STA, and provide a function that allows associated non-AP STAs (STA1 and STA4) to access the DS. In addition, since all APs are basically STAs, all APs are addressable entities. The address used by an AP for communication on a WM and the address used by an AP for communication on a DSM need not necessarily be the same. A BSS consisting of an AP and one or more STAs can be called an infrastructure BSS.

Data transmitted from one of the STA(s) associated with an AP to the STA address of that AP is always received on an uncontrolled port and can be processed by an IEEE 802.1X port access entity. In addition, if the controlled port is authenticated, the transmitted data (or frame) can be forwarded to the DS.

In addition to the structure of the DS described above, an Extended Service Set (ESS) may be established to provide wider coverage.

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

In a wireless LAN system, no assumption is made about the relative physical locations of the BSSs, and all of the following configurations are possible: The BSSs can be partially overlapped, which is a common configuration used to provide continuous coverage. Also, the BSSs can be physically unconnected, and logically there is no limit to the distance between the BSSs. Also, the BSSs can be physically co-located, which can be used to provide redundancy. Also, one (or more) IBSS or ESS networks can physically co-exist in the same space as one (or more) ESS networks. This can correspond to ESS network configurations such as cases where ad-hoc networks operate at locations where ESS networks exist, cases where physically overlapping wireless networks are configured by different organizations, or cases where two or more different access and security policies are required at the same location.

FIG. 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

In order for an STA to set up a link to a network and send and receive data, it must first discover the network, perform authentication, establish an association, and go through authentication procedures for security. The link setup process may also be referred to as a session initiation process or a session setup process. In addition, the discovery, authentication, association, and security setup processes of the link setup process may be collectively referred to as the association process.

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

There are two types of scanning methods: active scanning and passive scanning. FIG. 3 illustrates a network discovery operation including an active scanning process as an example. In active scanning, an STA performing scanning transmits a probe request frame to search for APs in the vicinity while moving between channels and waits for a response thereto. A responder transmits a probe response frame to the STA that transmitted the probe request frame as a response to the probe request frame. Here, the responder may be an STA that last transmitted a beacon frame in the BSS of the channel being scanned. In the BSS, the AP transmits a beacon frame, so the AP becomes the responder, and in the IBSS, the STAs within the IBSS take turns transmitting beacon frames, so the responder is not fixed. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 can store BSS-related information included in the received probe response frame and move to the next channel (e.g., channel 2) to perform scanning (i.e., transmitting and receiving probe request/response on channel 2) in the same manner.

Although not shown in FIG. 3, the scanning operation can also be performed in a passive scanning manner. In passive scanning, an STA performing scanning moves through channels and waits for a beacon frame. A beacon frame is one of the management frames defined in IEEE 802.11, and is periodically transmitted to notify the existence of a wireless network and to enable an STA performing scanning to find a wireless network and participate in the wireless network. In a BSS, an AP periodically transmits a beacon frame, and in an IBSS, STAs in the IBSS take turns transmitting beacon frames. When an STA performing scanning receives a beacon frame, it stores information about the BSS included in the beacon frame and moves to another channel, recording beacon frame information on each channel. An STA receiving a beacon frame stores information related to the BSS included in the received beacon frame, moves to the next channel, and performs scanning on the next channel in the same manner. Comparing active scanning and passive scanning, active scanning has the advantage of lower delay and power consumption than passive scanning.

After the STA discovers the network, an authentication process may be performed in step S320. This authentication process may be referred to as a first authentication process to clearly distinguish it from the security setup operation of step S340 described below.

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

The authentication frame may include information such as an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a Robust Security Network (RSN), a Finite Cyclic Group, etc. These are just some examples of information that may be included in an authentication request/response frame, and may be replaced by other information or may include additional information.

The STA may transmit an authentication request frame to the AP. The AP may determine whether to allow authentication for the STA based on information included in the received authentication request frame. The AP may provide the result of the authentication processing to the STA through an authentication response frame.

After the STA is successfully authenticated, an association process may be performed in step S330. The association process includes a process in which the STA transmits an association request frame to the AP, and in response, the AP transmits an association response frame to the STA.

For example, the association request frame may include information about various capabilities, a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, RSN, mobility domains, supported operating classes, a Traffic Indication Map Broadcast request, interworking service capabilities, etc. For example, the association response frame may include information about 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 Indicator (RSNI), a mobility domain, a timeout interval (e.g., association comeback time), overlapping BSS scan parameters, a TIM broadcast response, a Quality of Service (QoS) map, etc. These are just a few examples of the information that may be included in a combined request/response frame, and may be replaced by other information or include additional information.

After the STA is successfully connected to the network, a security setup process may be performed in step S340. The security setup process of step S340 may be referred to as an authentication process through a Robust Security Network Association (RSNA) request/response, the authentication process of step S320 may be referred to as a first authentication process, and the security setup process of step S340 may be referred to simply as an authentication process.

The security setup process of step S340 may include a process of performing private key setup, for example, through 4-way handshaking via an Extensible Authentication Protocol over LAN (EAPOL) frame. Additionally, the security setup process may be performed according to a security method not defined in the IEEE 802.11 standard.

FIG. 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

In wireless LAN systems, the basic access mechanism of MAC (Medium Access Control) is the CSMA/CA (Carrier Sense Multiple Access with Collision Avoidance) mechanism. The CSMA/CA mechanism is also called the Distributed Coordination Function (DCF) of IEEE 802.11 MAC, and basically adopts the "listen before talk" access mechanism. According to this type of access mechanism, the AP and/or STA may perform a Clear Channel Assessment (CCA) to sense the wireless channel or medium for a predetermined time period (e.g., a DCF Inter-Frame Space (DIFS)) before starting transmission. If the sensing result determines that the medium is in an idle state, the AP and/or STA may start transmitting frames through the medium. On the other hand, if the medium is detected to be occupied or busy, the AP and/or STA may not start its own transmission, but may wait for a delay period (e.g., a random backoff period) for medium access and then attempt to transmit frames. By applying the random backoff period, it is expected that multiple STAs will attempt to transmit frames after waiting for different periods of time, thereby minimizing collisions.

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 in which all receiving APs and/or STAs periodically poll to receive data frames. In addition, the HCF has EDCA (Enhanced Distributed Channel Access) and HCCA (HCF Controlled Channel Access). EDCA is a contention-based access method in which a provider provides data frames to multiple users, and HCCA uses a non-contention-based channel access method using a polling mechanism. In addition, the HCF includes a medium access mechanism for improving the QoS (Quality of Service) of a wireless LAN, and can transmit QoS data in both a contention period (CP) and a contention-free period (CFP).

Referring to Fig. 4, an operation based on a random backoff period is described. When an occupied/busy medium changes to an idle state, multiple STAs may attempt to transmit data (or frames). As a measure to minimize collisions, each STA may select a random backoff count, wait for a corresponding slot time, and then attempt to transmit. The random backoff count has a pseudo-random integer value and may be determined as one of the values in the range of 0 to CW. Here, CW is a contention window parameter value. The CW parameter is initially given CWmin, but may take a double value in case of a transmission failure (e.g., when an ACK for a transmitted frame is not received). When the CW parameter value becomes CWmax, data transmission may be attempted while maintaining the CWmax value until data transmission is successful, and if data transmission is successful, it is reset to the CWmin value. It is desirable that the CW, CWmin and CWmax values be set to 2 ⁿ -1 (n=0, 1, 2, ...).

When the random backoff process starts, the STA continues to monitor the medium while counting down the backoff slots according to the determined backoff count value. If the medium is monitored as occupied, the countdown stops and waits, and when the medium becomes idle, the remaining countdown is resumed.

In the example of Fig. 4, when a packet to be transmitted reaches the MAC of STA3, STA3 can check that the medium is idle for DIFS and transmit the frame right away. The remaining STAs monitor whether the medium is occupied/busy and wait. In the meantime, data to be transmitted may also occur in each of STA1, STA2, and STA5, and each STA can perform a countdown of the backoff slot according to a random backoff count value selected by each STA after waiting for DIFS when the medium is monitored as idle. Assume that STA2 selects the smallest backoff count value and STA1 selects the largest backoff count value. In other words, this example shows a case where the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1 when STA2 finishes the backoff count and starts frame transmission. STA1 and STA5 briefly stop the countdown and wait while STA2 occupies the medium. When STA2's occupation ends and the medium becomes idle again, STA1 and STA5 resume the stopped backoff count after waiting for DIFS. That is, they can start frame transmission after counting down the remaining backoff slots by the remaining backoff time. Since the remaining backoff time of STA5 is shorter than that of STA1, STA5 starts frame transmission. While STA2 occupies the medium, STA4 may also have data to transmit. From STA4's perspective, when the medium becomes idle, it waits for DIFS, performs a countdown according to the random backoff count value it selected, and starts frame transmission. In the example of Fig. 4, the remaining backoff time of STA5 coincidentally matches the random backoff count value of STA4, and in this case, a collision may occur between STA4 and STA5. If a collision occurs, neither STA4 nor STA5 will receive an ACK, resulting in a failure in data transmission. In this case, STA4 and STA5 can select a random backoff count value and perform a countdown after doubling the CW value. STA1 waits while the medium is occupied by transmissions from STA4 and STA5, and when the medium becomes idle, it waits for DIFS, and then starts transmitting frames after the remaining backoff time has elapsed.

As in the example of FIG. 4, a data frame is a frame used for transmitting data forwarded to a higher layer, and can be transmitted after a backoff performed after DIFS elapses from when the medium becomes idle. Additionally, a management frame is a frame used for exchanging management information that is not forwarded to a higher layer, and is transmitted after a backoff performed after an IFS such as DIFS or PIFS (Point coordination function IFS) elapses. Subtype frames of the management frame include a beacon, an association request/response, a re-association request/response, a probe request/response, and an authentication request/response. A control frame is a frame used to control access to the medium. The subtype frames of the control frame include RTS (Request-To-Send), CTS (Clear-To-Send), ACK (Acknowledgment), PS-Poll (Power Save-Poll), Block ACK (BlockAck), Block ACK Request (BlockACKReq), NDP notification (null data packet announcement), and Trigger. If the control frame is not a response frame to the previous frame, it is transmitted after the backoff performed after the DIFS (DIFS), and if it is a response frame to the previous frame, it is transmitted without the backoff performed after the SIFS (short IFS). The type and subtype of the frame can be identified by the type field and subtype field in the frame control (FC) field.

A QoS (Quality of Service) STA can transmit a frame after a backoff performed after the AIFS (arbitration IFS) for the access category (AC) to which the frame belongs, that is, AIFS[i] (where i is a value determined by the AC), has elapsed. Here, the frames for which AIFS[i] can be used can be data frames, management frames, and also control frames that are not response frames.

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

As described above, the CSMA/CA mechanism includes virtual carrier sensing in addition to physical carrier sensing in which an STA directly senses the medium. Virtual carrier sensing is intended to complement problems that may occur in medium access, such as the hidden node problem. For virtual carrier sensing, the MAC of the STA may utilize a Network Allocation Vector (NAV). The NAV is a value that indicates to other STAs the remaining time until the medium becomes available, by an STA that is currently using or has the right to use the medium. Therefore, the value set as NAV corresponds to the period during which the medium is scheduled to be used by the STA transmitting the corresponding frame, and the STA that receives the NAV value is prohibited from accessing the medium during the corresponding period. For example, the NAV may be set based on the value of the "duration" field of the MAC header of the frame.

In the example of FIG. 5, it is assumed that STA1 wants to transmit data to STA2, and STA3 is in a position to overhear part or all of the frames transmitted and received between STA1 and STA2.

In order to reduce the possibility of collision of transmissions of multiple STAs in a CSMA/CA-based frame transmission operation, a mechanism using RTS/CTS frames may be applied. In the example of FIG. 5, while STA1 is transmitting, STA3 may determine that the carrier sensing result of the medium is idle. That is, STA1 may correspond to a hidden node to STA3. Alternatively, while STA2 is transmitting, STA3 may determine that the carrier sensing result of the medium is idle. That is, STA2 may correspond to a hidden node to STA3. Before performing data transmission and reception between STA1 and STA2, by exchanging RTS/CTS frames, STAs outside the transmission range of either STA1 or STA2, or STAs outside the carrier sensing range for transmission from STA1 or STA3 may not attempt to occupy the channel during data transmission and reception between STA1 and STA2.

Specifically, STA1 can determine whether a channel is occupied through carrier sensing. In terms of physical carrier sensing, STA1 can determine a channel occupied idle state based on energy magnitude or signal correlation detected in the channel. In addition, in terms of virtual carrier sensing, STA1 can determine a channel occupied state using a network allocation vector (NAV) timer.

STA1 can transmit an RTS frame to STA2 after performing a backoff if the channel is idle during DIFS. STA2 can transmit a CTS frame, which is a response to the RTS frame, to STA1 after SIFS if it receives the RTS frame.

If STA3 cannot overhear the CTS frame from STA2 but can overhear the RTS frame from STA1, STA3 can set a NAV timer for the subsequently transmitted frame transmission period (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame) using the duration information included in the RTS frame. Alternatively, if STA3 cannot overhear the RTS frame from STA1 but can overhear the CTS frame from STA2, STA3 can set a NAV timer for the subsequently transmitted frame transmission period (e.g., SIFS + data frame + SIFS + ACK frame) using the duration information included in the CTS frame. That is, if STA3 can overhear one or more of the RTS or CTS frames from one or more of STA1 or STA2, it can set a NAV accordingly. STA3 can update the NAV timer using the duration information contained in the new frame if it receives a new frame before the NAV timer expires. STA3 does not attempt to access the channel until the NAV timer expires.

If STA1 receives a CTS frame from STA2, it can transmit a data frame to STA2 after SIFS from the time when reception of the CTS frame is completed. If STA2 successfully receives the data frame, it can transmit an ACK frame in response to the data frame to STA1 after SIFS. STA3 can determine whether the channel is in use through carrier sensing if the NAV timer expires. If STA3 determines that the channel is not in use by other terminals during DIFS after the expiration of the NAV timer, it can attempt channel access after a contention window (CW) following a random backoff has elapsed.

FIG. 6 is a drawing for explaining an example of a frame structure used in a wireless LAN system to which the present disclosure can be applied.

The PHY layer can prepare an MPDU (MAC PDU) to be transmitted by an instruction or primitive (meaning a set of instructions or parameters) from the MAC layer. For example, when a command requesting the start of transmission of the PHY layer is received from the MAC layer, the PHY layer can switch to transmission mode and transmit information (e.g., data) provided from the MAC layer in the form of a frame. In addition, when the PHY layer detects a valid preamble of the received frame, it monitors the header of the preamble and sends a command to the MAC layer notifying the start of reception of the PHY layer.

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

A 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 (e.g., non-HT (High Throughput) as illustrated in FIG. 7) PPDU format may consist of only a Legacy-STF (L-STF), a Legacy-LTF (L-LTF), a Legacy-SIG (Legacy-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 field, non-legacy STF, non-legacy LTF, (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx represents HT, VHT, HE, EHT, etc.)) may be included between the L-SIG field and the data field. More specific details are described below with reference to FIG. 7.

STF is a signal for signal detection, AGC (Automatic Gain Control), diversity selection, precise time synchronization, etc., and LTF is a signal for channel estimation, frequency error estimation, etc. STF and LTF can be said to be signals for OFDM physical layer synchronization and channel estimation.

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

The data field may include a SERVICE field, a Physical layer Service Data Unit (PSDU), a PPDU TAIL bit, and, if necessary, padding bits. Some bits of the SERVICE field may be used for synchronization of a descrambler at the receiving end. The PSDU corresponds to a MAC PDU defined at the MAC layer and may include data generated/used at a higher layer. The PPDU TAIL bit may be used to return the encoder to the 0 state. The padding bit may be used to adjust the length of the data field to a predetermined unit.

MAC PDU is defined according to various MAC frame formats, and the basic MAC frame consists of a MAC header, frame body, and FCS (Frame Check Sequence). MAC frame consists of MAC PDU and can be transmitted/received through PSDU of the data part of PPDU format.

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 a time for transmitting the corresponding frame, etc. The Address subfields may indicate a receiver address, a transmitter address, a destination address, and a source address of the frame, and some Address subfields may be omitted. For specific details of each subfield of the MAC header, including the Sequence Control, QoS Control, and HT Control subfields, refer to the IEEE 802.11 standard document.

Null-Data PPDU (NDP) format refers to a PPDU format that does not include a data field. That is, NDP refers to a frame format that includes a PPDU preamble (i.e., L-STF, L-LTF, L-SIG fields, and additionally, non-legacy SIG, non-legacy STF, non-legacy LTF if present) in a general PPDU format, and does not include the remaining part (i.e., data field).

FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

Various forms of PPDUs are used in standards such as IEEE 802.11a/g/n/ac/ax. The basic PPDU format (IEEE 802.11a/g) includes L-LTF, L-STF, L-SIG, and Data fields. The basic PPDU format can also be called a non-HT PPDU format (Fig. 7(a)).

The HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT(s) fields in the basic PPDU format. The HT PPDU format illustrated in Fig. 7(b) may be referred to as an HT-mixed format. Additionally, an HT-greenfield format PPDU may be defined, which corresponds to a format that does not include L-STF, L-LTF, and L-SIG, and consists of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTF, and Data fields (not illustrated).

An example of a VHT PPDU format (IEEE 802.11ac) includes VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields in addition to the basic PPDU format (Fig. 7(c)).

An example of a HE PPDU format (IEEE 802.11ax) additionally includes RL-SIG (Repeated L-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), and PE (Packet Extension) fields in the basic PPDU format (Fig. 7(d)). Depending on specific examples of the HE PPDU format, some fields may be excluded or their lengths may vary. For example, the HE-SIG-B field is included in a HE PPDU format for multi-users (MUs), and the HE PPDU format for single users (SUs) does not include the HE-SIG-B. In addition, a HE trigger-based (TB) PPDU format does not include the HE-SIG-B, and the length of the HE-STF field may vary to 8us. A HE ER (Extended Range) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may vary to 16us. For example, RL-SIG can be configured identically to L-SIG. The receiving STA can know that the received PPDU is a HE PPDU or an EHT PPDU, described later, based on the presence of RL-SIG.

The EHT PPDU format may include the EHT MU (multi-user) PPDU of Fig. 7(e) and the EHT TB (trigger-based) PPDU of Fig. 7(f). The EHT PPDU format is similar to the HE PPDU format in that it includes an RL-SIG following an L-SIG, but it may include a U (universal)-SIG, an EHT-SIG, an EHT-STF, and an EHT-LTF following the RL-SIG.

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

The EHT TB PPDU of Fig. 7(f) omits EHT-SIG compared to the EHT MU PPDU. An STA that has received a trigger for UL MU transmission (e.g., a trigger frame or TRS (triggered response scheduling)) can perform UL transmission based on the EHT TB PPDU format.

The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal SIGNAL), and EHT-SIG fields can be encoded and modulated and mapped based on a predetermined subcarrier frequency interval (e.g., 312.5 kHz) so that even legacy STAs can attempt to demodulate and decode them. These can be referred to as pre-EHT modulated fields. Next, the EHT-STF, EHT-LTF, Data, and PE fields can be encoded and modulated and mapped based on a predetermined subcarrier frequency interval (e.g., 78.125 kHz) so that they can be demodulated and decoded by an STA that successfully decodes a non-legacy SIG (e.g., U-SIG and/or EHT-SIG) and obtains the information included in the corresponding fields. These can be referred to as EHT modulated fields.

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

The U-SIG included in the EHT PPDU format of Fig. 7 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 4us, and the U-SIG can have a total duration of 8us. 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.

U-SIG can be configured in 20MHz units. For example, when an 80MHz PPDU is configured, the same U-SIG can be replicated in 20MHz units. That is, four identical U-SIGs can be included in an 80MHz PPDU. When the bandwidth exceeds 80MHz, for example, for a 160MHz PPDU, the U-SIG of the first 80MHz unit and the U-SIG of the second 80MHz unit can be different.

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

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

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

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

For example, the version-dependent bits of the U-SIG may contain information that directly or indirectly indicates the type of the PPDU (e.g., SU PPDU, MU PPDU, TB PPDU, etc.).

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

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

Preamble puncturing may mean transmission of a PPDU in which no signal is present in one or more frequency units within the bandwidth of the PPDU. For example, the size of the frequency unit (or the resolution of the preamble puncturing) may be defined as 20 MHz, 40 MHz, etc. For example, preamble puncturing may be applied to a PPDU bandwidth greater than a predetermined size.

In the example of Fig. 7, non-legacy SIGs such as HE-SIG-B, EHT-SIG, etc. may include control information for the receiving STA. The non-legacy SIG may be transmitted through at least one symbol, and one symbol may have a length of 4 us. Information about the number of symbols used for EHT-SIG may be included in a previous SIG (e.g., HE-SIG-A, U-SIG, etc.).

Non-legacy SIGs, such as HE-SIG-B, EHT-SIG, etc., may contain common fields and user-specific fields. Common fields and user-specific fields may be coded separately.

In some cases, the common field may be omitted. For example, in a compressed mode where non-OFDMA (orthogonal frequency multiple access) is applied, the common field may be omitted, and multiple STAs may receive a PPDU (e.g., a data field of a PPDU) over the same frequency band. In a non-compressed mode where OFDMA is applied, multiple users may receive a PPDU (e.g., a data field of a PPDU) over different frequency bands.

The number of user-specific fields can be determined based on the number of users. One user block field can include at most two user fields. Each user field can be associated with an MU-MIMO allocation or associated with a non-MU-MIMO allocation.

The common field may include CRC bits and Tail bits, the length of the CRC bits may be determined as 4 bits, the length of the Tail bits may be determined as 6 bits and may be set to 000000. The common field may include RU allocation information. The RU allocation information may include information about the location of RUs to which multiple users (i.e., multiple receiving STAs) are allocated.

An RU may include multiple subcarriers (or tones). An RU may be used when transmitting signals to multiple STAs based on the OFDMA technique. An RU may also be defined when transmitting signals to one STA. Resources may be allocated in RU units for non-legacy STFs, non-legacy LTFs, and Data fields.

According to the PPDU bandwidth, an applicable size of RU can be defined. The RU may be defined identically or differently for the applicable PPDU format (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.). For example, in case of 80MHz PPDU, the RU arrangements of HE PPDU and EHT PPDU may be different. The applicable RU size, RU number, RU position, DC (direct current) subcarrier position and number, null subcarrier position and number, guard subcarrier position and number, etc. for each PPDU bandwidth can be referred to as a tone plan. For example, a tone plan for a wide bandwidth can be defined in the form of multiple repetitions of a tone plan for a low bandwidth.

RUs of different sizes can be defined, such as 26-tone RU, 52-tone RU, 106-tone RU, 242-tone RU, 484-tone RU, 996-tone RU, 2Х996-tone RU, 3Х996-tone RU, etc. A multiple RU (MRU) is distinct from multiple individual RUs and corresponds to a group of subcarriers consisting of multiple RUs. For example, one MRU can be defined as 52+26-tones, 106+26-tones, 484+242-tones, 996+484-tones, 996+484+242-tones, 2Х996+484-tones, 3Х996-tones, or 3Х996+484-tones. Additionally, multiple RUs constituting one MRU may or may not be consecutive in the frequency domain.

The specific size of the RU may be reduced or expanded. Therefore, the specific size of each RU (i.e., the number of corresponding tones) in the present disclosure is not limited and is exemplary. In addition, within a given bandwidth (e.g., 20, 40, 80, 160, 320 MHz, ...) in the present disclosure, the number of RUs may vary depending on the RU size.

The names of each field in the PPDU formats of FIG. 7 are exemplary, and the scope of the present disclosure is not limited by the names. In addition, the examples of the present disclosure can be applied not only to the PPDU format exemplified in FIG. 7, but also to a new PPDU format in which some fields are excluded and/or some fields are added based on the PPDU formats of FIG. 7.

Preamble puncturing may be applied to the PPDU of FIG. 7. Preamble puncturing means applying puncturing to some bands (e.g., secondary 20 MHz band) among the entire band of the PPDU. For example, when an 80 MHz PPDU is transmitted, the STA may apply puncturing to the secondary 20 MHz band among the 80 MHz band, and transmit the PPDU only through the primary 20 MHz band and the secondary 40 MHz band.

For example, the pattern of preamble puncturing can be preset. For example, when the first puncturing pattern is applied, puncturing can be applied only to a secondary 20 MHz band within an 80 MHz band. For example, when the second puncturing pattern is applied, puncturing can be applied only to one of two secondary 20 MHz bands included in a secondary 40 MHz band within an 80 MHz band. For example, when the third puncturing pattern is applied, puncturing can be applied only to a secondary 20 MHz band included in a primary 80 MHz band within a 160 MHz band (or an 80+80 MHz band). For example, when the 4th puncturing pattern is applied, a primary 40 MHz band included in the primary 80 MHz band within the 160 MHz band (or 80+80 MHz band) is present, and puncturing can be applied to at least one 20 MHz channel that does not belong to the primary 40 MHz band.

Information about preamble puncturing applied to the PPDU may be included in the U-SIG and/or EHT-SIG. For example, a first field of the U-SIG may include information about a contiguous bandwidth of the PPDU, and a second field of the U-SIG may include information about preamble puncturing applied to the PPDU.

For example, U-SIG and EHT-SIG may include information regarding preamble puncturing based on the following method. If the bandwidth of the PPDU exceeds 80 MHz, U-SIGs may be individually configured in units of 80 MHz. For example, if the bandwidth of the PPDU is 160 MHz, the PPDU may include a first U-SIG for a first 80 MHz band and a second U-SIG for a second 80 MHz band. In this case, the first field of the first U-SIG may include information regarding the 160 MHz bandwidth, and the second field of the first U-SIG may include information regarding preamble puncturing applied to the first 80 MHz band (i.e., information regarding a preamble puncturing pattern). Additionally, the first field of the second U-SIG may include information about a 160 MHz bandwidth, and the second field of the second U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about a preamble puncturing pattern). The EHT-SIG consecutive to the first U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about a preamble puncturing pattern), and the EHT-SIG consecutive to the second U-SIG may include information about preamble puncturing applied to the first 80 MHz band (i.e., information about a preamble puncturing pattern).

Additionally or alternatively, U-SIG and EHT-SIG may include information about preamble puncturing based on the following methods. U-SIG may include information about preamble puncturing for all bands (i.e., information about preamble puncturing pattern). That is, EHT-SIG does not include information about preamble puncturing, and only U-SIG may include information about preamble puncturing (i.e., information about preamble puncturing pattern).

U-SIG can be configured in 20 MHz units. For example, if an 80 MHz PPDU is configured, U-SIG can be duplicated. That is, four identical U-SIGs can be included in an 80 MHz PPDU. PPDUs exceeding 80 MHz bandwidth can contain different U-SIGs.

The EHT-SIG of Fig. 7 may include control information for a receiving STA. The EHT-SIG may be transmitted through at least one symbol, and one symbol may have a length of 4 us. Information about the number of symbols used for the EHT-SIG may be included in the U-SIG.

EHT-SIG may include the technical features of HE-SIG-B described above. For example, EHT-SIG may include common fields and user-specific fields. The common fields of EHT-SIG may be omitted, and the number of user-specific fields may be determined based on the number of users.

The common fields of EHT-SIG and the user-specific fields of EHT-SIG can be coded separately. One user block field included in the user-specific fields includes information for two user fields, but the last user block field included in the user-specific fields can include one or two user fields. That is, one user block field of EHT-SIG can include at most two user fields. Each user field can be related to MU-MIMO allocation or related to non-MU-MIMO allocation.

The common fields of EHT-SIG can include CRC bits and Tail bits, the length of the CRC bits can be determined as 4 bits, and the length of the Tail bits can be determined as 6 bits and set to 000000.

The common field of EHT-SIG may include RU allocation information. The RU allocation information may mean information about the location of RUs to which multiple users (i.e., multiple receiving STAs) are allocated. The RU allocation information may be composed of 8-bit (or N-bit) units.

A mode in which common fields of EHT-SIG are omitted may be supported. The mode in which common fields of EHT-SIG are omitted may be called compressed mode. When the compressed mode is used, multiple users of EHT PPDU (i.e., multiple receiving STAs) can decode PPDU (e.g., data field of PPDU) based on non-OFDMA. That is, multiple users of EHT PPDU can decode PPDU (e.g., data field of PPDU) received over the same frequency band. When the non-compressed mode is used, multiple users of EHT PPDU can decode PPDU (e.g., data field of PPDU) based on OFDMA. That is, multiple users of EHT PPDU can receive PPDU (e.g., data field of PPDU) over different frequency bands.

EHT-SIG can be configured based on various MCS techniques. As described above, information related to the MCS technique applied to EHT-SIG can be included in U-SIG. EHT-SIG can be configured based on DCM technique. For example, among N data tones (e.g., 52 data tones) allocated for EHT-SIG, a first modulation technique can be applied to consecutive half tones, and a second modulation technique can be applied to the remaining consecutive half tones. That is, a transmitting STA can modulate specific control information into a first symbol based on the first modulation technique and allocate it to consecutive half tones, and modulate the same control information into a second symbol based on the second modulation technique and allocate it to the remaining consecutive half tones. As described above, information (e.g., a 1-bit field) related to whether the DCM technique is applied to EHT-SIG can be included in U-SIG. The EHT-STF of Fig. 7 can be used to improve automatic gain control (AGC) estimation in a MIMO environment or an OFDMA environment. The EHT-LTF of Fig. 7 can be used to estimate a channel in a MIMO environment or an OFDMA environment.

Information about the type of STF and/or LTF (including information about the guard interval (GI) applied to the LTF) may be included in the U-SIG field and/or the EHT-SIG field of FIG. 7.

trigger frame

FIG. 8 is a diagram showing an exemplary format of a trigger frame to which the present disclosure can be applied.

A trigger frame may allocate resources for one or more TB PPDU transmissions and may request TB PPDU transmissions. The trigger frame may also include other information required by an STA transmitting a TB PPDU in response thereto. The trigger frame may include common info and user info list fields in the frame body.

The common information field may include information common to one or more TB PPDU transmissions requested by the trigger frame, such as trigger type, UL length, presence of a subsequent trigger frame (e.g., More TF), whether CS (channel sensing) is required, UL BW (bandwidth), etc.

The 4-bit trigger type subfield can have values from 0 to 15. Among them, the values 0, 1, 2, 3, 4, 5, 6, and 7 of the trigger type subfield are defined to correspond to basic, BFRP (Beamforming Report Poll), MU-BAR (multi user-block acknowledgement request), MU-RTS (multi user-request to send), BSRP (Buffer Status Report Poll), GCR (groupcast with retries) MU-BAR, BQRP (Bandwidth Query Report Poll), and NFRP (NDP Feedback Report Poll), respectively, and the values 8 to 15 are defined as reserved.

Among the common information, the trigger dependent common info subfield may include information that is optionally included based on the trigger type.

A special user info field may be included within the trigger frame. The special user info field does not contain user-specific information, but rather contains extended common information not provided in the common information field.

A user info list contains zero or more user info fields. Figure 8 illustrates an example of an EHT variant user info field format.

The AID12 subfield basically indicates that it is a user information field for an STA having the corresponding AID. In addition, if the AID12 field has a predetermined specific value, it may be utilized for other purposes, such as allocating a random access (RA)-RU, or being configured in the form of a special user info field. The special user info field is a user info field that does not include user specific information but includes extended common information that is not provided in the common information field. For example, the special user info field can be identified by the AID12 value of 2007, and the special user info field flag subfield in the common information field can indicate whether the special user info field is included.

The RU allocation subfield can indicate the size and location of RU/MRU. For this purpose, the RU allocation subfield can be interpreted together with the PS160 (primary/secondary 160MHz) subfield of the user information field, the UL BW subfield of the common information field, etc.

How to share transmission opportunities (TXOPs) for multi-AP operation

A non-EHT non-AP HE STA interprets the common info field as an HE variant common info field. In addition, if B54 and B54 in the common info field are equal to 1, the non-AP EHT STA interprets the common info field as an HE variant common info field. Otherwise, the non-AP EHT STA interprets the common info field as an EHT variant common info field.

FIG. 9 is a diagram showing the format of a common information field in a trigger frame to which the present disclosure can be applied.

Referring to FIG. 9, the EHT variant common information field may include information that is common to one or more TB PPDU transmissions requested by the trigger frame.

The EHT variant common information field contains a trigger type subfield that identifies the trigger frame variant.

Table 1 illustrates the trigger type subfield encoding.

In addition, the EHT variant common information field includes a UL length subfield indicating an L-SIG length (LENGTH) field of a solicited TB PPDU, a More TF subfield indicating whether a subsequent trigger frame (TF) is scheduled, a number Of HE/EHT-LTF symbols subfield indicating EHT-LTF symbols, an LDPC extra symbol segment subfield indicating the status of an LDPC (low-density parity check) symbol segment, an AP transmit power (AP Tx power) subfield indicating the combined transmit power of the AP at the transmit antenna connectors of all antennas used for triggering PPDU transmission, a pre-FEC (forward error correction) padding factor subfield, a PE (packet extension) disambiguity subfield, and an UL spatial reuse subfield. It may include a subfield, a HE/EHT P160 subfield, a special user info field flag subfield, and a trigger dependent common info subfield.

In 802.11be (EHT), a technique was proposed to allocate some time within the TXOP acquired by the AP to the associated non-AP STAs to support peer-to-peer (P2P) transmissions. For this purpose, the TXOP sharing mode subfield (or triggered TXOP sharing mode subfield) in the common info field of the existing MU-RTS frame was defined.

That is, if the trigger type subfield indicates an MU-RTS trigger frame (see Table 1), B20-B21 of the EHT variant common information field are triggered TXOP sharing mode subfields, otherwise they are GI (guard interval) and HE/EHT-LTF type subfields.

Table 2 illustrates the encoding of the triggered TXOP sharing mode subfield.

Referring to Table 2, if the triggered TXOP sharing mode subfield in the common info field of an MU-RTS frame transmitted by an AP is set to a non-zero value, the MU-RTS frame instructs associated non-AP STAs that sequentially transmit one or more non-TB PPDUs to allocate time within the acquired TXOP. Otherwise, the triggered TXOP sharing mode subfield is set to 0.

An MU-RTS triggered frame with the triggered TXOP sharing mode subfield set to a non-zero value is referred to as an MU-RTS TXS (TXOP sharing) triggered frame.

If the triggered TXOP sharing mode subfield is 1, it indicates that the MU-RTS initiates a TXOP sharing (TXS) procedure in which the scheduled STA can transmit only MPDU(s) addressed to the associated AP, i.e., support transmission of one or more (non-TB) PPDUs to the AP.

If the triggered TXOP sharing mode subfield is 2, it indicates that the MU-RTS initiates a TXS procedure that allows the scheduled STA to transmit MPDU(s) addressed to the associated AP or addressed to another STA. That is, P2P transmission is also supported.

The triggered TXOP sharing mode subfield 3 is reserved.

The operation using the triggered TXOP sharing mode subfield is as follows:

FIG. 10 illustrates a TXOP sharing procedure in a wireless LAN system to which the present disclosure can be applied.

FIG. 10 illustrates an exchange of MU-RTS TXS trigger frames preceded by PPDU transmissions to AP and other STAs by scheduled STAs within the time allocated by the MU-RTS TXS trigger frame and optional CTS-to-Self transmission when the triggered TXOP sharing mode subfield value is 2.

The AP transmits an MU-RTS TXS trigger frame including time allocation information to STA 1. If STA 1 responds to this with CTS (Clear-To-Send) to the AP, STA 1 can transmit data to the AP within a non-TB PPDU and also perform P2P transmission to STA 2 (i.e., transmit data to STA 1). The allocated time is indicated by the user info field in the MU-RTS TXS trigger frame.

FIG. 11 illustrates the user information field format of an MU-RTS TXS trigger frame to which the present disclosure can be applied.

Referring to FIG. 11, the EHT variant user info field in the MU-RTS TXS trigger frame is composed of an AID12 subfield, a RU allocation subfield, an allocation duration subfield, and a PS160 subfield.

The AID12 subfield basically indicates that it is a user information field for the STA with the corresponding AID.

The RU allocation subfield can indicate the size and location of RU/MRU. For this purpose, the RU allocation subfield can be interpreted together with the PS160 (primary/secondary 160MHz) subfield of the user information field, the UL BW subfield of the common information field, etc.

The allocation duration subfield indicates the time allocated to a non-AP STA within a TXOP acquired by the AP in 16 us units.

Here, from the non-AP STA perspective, the time is applied from the time when the PHY-RXEND.indication primitive for the PPDU containing the MU-RTS TXS trigger frame is issued.

How to share TXOPs and allocate bandwidth for relay operation

The next-generation wireless LAN (beyond 802.11be) aims to support ultra-high reliability in signal transmission to STAs, and various technologies are being considered for high throughput, low latency, and extended range support. To this end, signal transmission using a relay can be considered to extend the coverage of signal transmission of the AP as well as the reliability within the AP coverage. In order to extend the range through relay operation, an AP signal (e.g., a management frame such as a beacon frame) can be transmitted to a non-AP STA outside the AP coverage through a relay STA. In this way, in order to efficiently transmit and receive signals to and from destination STAs through relay communication, the AP can share its transmission opportunity (TXOP: transmission opportunity) for relay transmission so that relay transmission can be performed.

In this disclosure, we propose a TXOP sharing procedure for sharing a TXOP for relay transmission set by an AP with a relay STA and/or a destination STA. In addition, we define a method for setting a bandwidth (BW) for performing relay communication.

FIG. 12 is a diagram exemplifying range expansion using a relay in a wireless LAN system to which the present disclosure can be applied.

In the next generation wireless LAN (beyond 802.11be), relay STAs can be used to ensure smooth signal transmission and reception for STAs located at the coverage boundary of the AP and to extend the coverage of the AP to transmit and receive signals.

Here, the relay STA may be an AP STA or a non-AP STA. For example, if the relay STA is an AP STA, the relay STA can support/perform only AP functions. In addition, for example, if the relay STA is a non-AP STA, the relay STA can support/perform only non-AP STA functions. In addition, for example, the relay STA may be an STA that can support/perform both AP functions and non-AP STA functions.

Hereinafter, in the description of the present disclosure, for convenience of explanation, the relay STA is mainly described as a non-AP STA, but the present disclosure is not limited thereto.

Through signal transmission and reception using a relay STA, an AP can transmit and receive signals with an STA that exists outside the coverage of the AP, as shown in Fig. 12.

As shown in FIG. 12, when using a relay operation to transmit and receive signals to an STA that exists outside the coverage/range of the AP, frames/PPDUs (e.g., management frames) transmitted by the AP can be transmitted to an STA (e.g., a destination STA, an end-STA, or a non-AP STA) through the relay STA.

In addition, for example, STAs that exist outside the coverage/range of the AP cannot receive the beacon frame transmitted by the AP. Therefore, after the relay STA receives the beacon frame transmitted by the AP, the relay STA can broadcast the beacon frame. In this way, non-AP STAs that exist outside the coverage of the AP that have received the beacon frame transmitted by the relay STA can transmit signals to the relay STA not only for association with the AP but also for signal transmission and reception, and the relay STA that has received the signals of these non-AP STAs can transmit the signals of the non-AP STAs that have been received to the AP.

In this way, a relay STA that receives a signal from an AP or a non-AP STA requires a channel access process involving contention in order to transmit the received signal to a non-AP STA or an AP. However, since the relay STA requires the above-described channel acquisition/access process repeatedly in order to transmit signals to multiple non-AP STAs, there is a disadvantage in that transmission efficiency is reduced. In addition, since channel contention is involved when the relay STA performs channel access, a channel access delay may occur, which may cause a latency problem.

To reduce channel contention of Relay STA and prevent channel access delay, relay transmission using TXOP sharing can be considered and can be performed using the following procedure.

Example 1: Method of allocating shared time to relay STA

In order to perform relay communication, the AP can set all or part of the time within the TXOP it has acquired as a separate TXOP or a specific time interval for relay communication, and allocate/share the set time interval to the relay STA.

Information about shared time or TXOP for relay communication can be transmitted from the AP to the Relay STA using frames (e.g., trigger frame, TXS (TXOP sharing) trigger frame, etc.).

In the following description of the present disclosure, for convenience of explanation, a case is mainly described where a TXS trigger frame is used as a frame carrying information about a shared time or TXOP for relay communication; however, the present disclosure is not limited thereto, and other types of trigger frames, etc. may be used.

Here, the TXS trigger frame can be transmitted to the relay STA using the operating bandwidth (operating BW) of the AP or the operating BW set at the time of association of the relay STA. Here, the operating BW can mean the BW for the PPDU transmitted including the TXS trigger frame transmitted by the AP, and for example, the operating BW can be indicated through the uplink bandwidth (UL bandwidth) field of the TXS trigger frame.

Here, the BW used in transmitting the TXS trigger frame may be configured to include punctured 20MHz channel(s) according to disallowed channel information/inactive sub-channels information of the AP. For example, in the transmission of the PPDU including the TXS trigger frame, one or more 20MHz bands within the operating BW may be punctured so that no signal exists.

The above TXS trigger frame may be configured to include one user info field for the relay STA. For example, the user info field may be configured identically to the user info field illustrated in FIG. 11, or may be configured with some fields added and/or excluded.

The above TXS trigger frame may be configured to include a special user info field containing common information.

Here, the special user information field may be configured to include an instruction for relay communication. And/or, the special user information field may also be configured to include a DL/UL instruction (i.e., a transmission direction instruction) for relay communication.

A relay STA can be identified by information contained in the user information field (e.g., an indication of the AID12 subfield).

A relay STA addressed/identified by the user information field of a TXS trigger frame may ignore (e.g., not perform a NAV setting update) the NAV setting set by the AP during a 'shared time interval' determined by using the time information of the received TXS trigger frame (e.g., information about the shared time or TXOP for relay communication) for transmitting a PPDU for relay communication. In addition, other STAs other than the relay STA may update the NAV setting.

In addition, among the STAs that have received the TXS trigger frame, a non-AP STA that supports relay communication or has relay communication capability can ignore the NAV setting set by the AP for (during) the 'shared time interval' identified using the time information of the trigger frame identified using the time information of the TXS trigger frame received during UL relay communication (e.g., information about the shared time or TXOP for relay communication) (e.g., not performing a NAV setting update).

A relay STA that receives a TXS trigger frame for relay communication from an AP can transmit a response frame (e.g., a CTS (Clear-To-Send) frame) in response.

In the following description of the present disclosure, for convenience of explanation, the case in which a CTS frame is responded to in response to a frame carrying information about a shared time or TXOP for relay communication is mainly described, but the present disclosure is not limited thereto, and other frames, etc. may be used.

Here, the relay STA can perform CCA in 20MHz units for the BW that received the PPDU including the TXS trigger frame and transmit the CTS frame using one or more idle 20MHz channel(s).

For example, the BW for the 20MHz channel(s) over which the CTS is transmitted may be less than or equal to the BW over which the relay STA received the PPDU containing the TXS trigger frame.

Additionally, for example, a PPDU including a CTS frame transmitted by a relay STA may be configured to include the same punctured 20MHz channel(s) reflecting disallowed channel information/inactive sub-channels information of the AP.

An AP that receives a PPDU including a CTS frame transmitted by a relay STA can transmit a signal or data for relay communication (e.g., a signal or data transmitted to a destination STA) to the relay STA using the BW in which the received PPDU was transmitted.

A relay STA that receives a signal or data from an AP can transmit an acknowledgment (ACK) frame to the AP, and then, after a certain period of time (e.g., SIFS), transmit the signal/data to destination STAs using the same BW as the BW through which the signal/PPDU was received from the AP.

FIG. 13 is a diagram illustrating a procedure for TXOP sharing and bandwidth determination for relay communication according to one embodiment of the present disclosure.

Referring to FIG. 13, an AP can transmit a TXS trigger frame to a relay STA using an 80MHz channel BW for relay communication. Here, as in the example of FIG. 13, a fourth order 20MHz subchannel included in the 80MHz BW can be transmitted by being punctured (i.e., puncturing pattern [0 0 0 1]).

A relay STA that receives a TXS trigger frame transmitted by an AP can perform CCA on the remaining 20MHz channels except for the punctured channel (i.e., the 20MHz subchannel of the 4th order) for the PPDU BW (80MHz) in which the TXS trigger frame was received to check for idle channels. As shown in FIG. 13, if the CCA result of the 20MHz channel of the 3rd order is found to be busy, the relay STA can transmit a PPDU including a CTS frame as a response by using the 40MHz channels (i.e., the 20MHz subchannels of the first and second orders) that are found to be idle channels excluding the punctured channel (e.g., after SIFS). The AP can transmit a signal/data to the relay STA by using the 40MHz in which the CTS was received (e.g., after SIFS).

A relay STA that receives a signal/data from an AP can transmit an ACK frame to the AP (e.g., after SIFS). After that (e.g., after SIFS), the relay STA can transmit a signal/data to the destination STA using the same BW (i.e., 40MHz consisting of the first and second 20MHz subchannels).

In Fig. 13, the 80MHz bandwidth and the preamble puncturing pattern are just an example for the convenience of explanation, and the present disclosure is not limited thereto. That is, the proposed method of the present invention can perform relay communication by considering 20/40/80/160/320MHz and various preamble puncturing patterns defined in 802.11be, and the operating BW for relay communication can be determined using the proposed method described above.

Example 2: Method for allocating shared time to both relay STA and destination STA(s)

In order to perform relay communication, the AP can set a TXOP or a specific time interval for relay communication within the TXOP it has acquired and allocate it to a relay STA.

Information about the shared time or TXOP for relay communication can be transmitted by the AP to the relay STA and destination STA(s) using frames (e.g., trigger frame, TXS (TXOP sharing) trigger frame, etc.).

In the following description of the present disclosure, for convenience of explanation, a case is mainly described where a TXS trigger frame is used as a frame carrying information about a shared time or TXOP for relay communication; however, the present disclosure is not limited thereto, and other types of trigger frames, etc. may be used.

Here, the TXS trigger frame can be transmitted to the relay STA and destination STA(s) by using the operating BW of the AP (e.g., set through negotiation with the AP) that is set at the time of association of the relay STA and destination STA(s). Here, the operating BW can mean the BW for a PPDU transmitted including the TXS trigger frame transmitted by the AP, and for example, the operating BW can be indicated through the uplink bandwidth (UL bandwidth) field of the TXS trigger frame.

Here, the BW used in transmitting the TXS trigger frame may be configured to include punctured 20MHz channel(s) according to disallowed channel information/inactive sub-channels information of the AP. For example, in the transmission of the PPDU including the TXS trigger frame, one or more 20MHz bands within the operating BW may be punctured so that no signal exists.

The above TXS trigger frame may be configured to include user information fields for the relay STA and destination STA(s). That is, the TXS trigger frame transmitted by the AP may be configured to include two or more user information fields. For example, the user information field may be configured identically to the user information field of the trigger frame illustrated in FIG. 11, or may be configured by adding and/or excluding some fields.

The above TXS trigger frame may be configured to include a special user info field containing common information.

Here, the special user information field may be configured to include an instruction for relay communication. And/or, the special user information field may also be configured to include a DL/UL instruction (i.e., a transmission direction instruction) for relay communication.

The relay STA and destination STA(s) can be identified by information included in the user information field (e.g., an indication of the AID12 subfield). That is, the relay STA and destination STA(s) can identify their own user information fields through this.

Here, all allocated time information included in the user information field (i.e., information about shared time or TXOP for relay communication) can be set identically.

For example, the allocated time information (i.e., shared time for relay communication or information about TXOP) may be configured as time information for the entire relay communication. For example, the time for the entire relay communication may correspond to the time from the start of transmission of the TXS trigger frame to the time when the relay STA completes transmitting the signal/data to the destination STA(s).

Or, as another example, the allocated time information included in each user information field may be configured with information about a period for performing signal/data transmission and reception for each STA. In this way, when configured with information about a time period for signal transmission and reception for each STA, the user information field may be configured by being arranged (ordered) in the time order in which signal/data transmission and reception is performed for each STA (i.e., each relay STA, destination STA(s)).

A relay STA addressed/identified by the user information field of a TXS trigger frame may use the timing information of the received TXS trigger frame (e.g., information about the shared time or TXOP for relay communication) to ignore the NAV setting set by the AP for the shared time period (e.g., not performing a NAV setting update).

Additionally, during UL relay operation, the destination STA(s) addressed/identified through the user information field included in the TXS trigger frame may ignore the NAV setting set by the AP for the shared time period (for example, by not performing a NAV setting update) by using the allocated time information of the received TXS trigger frame.

Example 2-1) A relay STA that receives a TXS trigger frame for relay communication from an AP can transmit a response frame (e.g., a CTS (Clear-To-Send) frame) in response thereto.

In the following description of the present disclosure, for convenience of explanation, the case in which a CTS frame is responded in response to a frame carrying information about a shared time or TXOP for relay communication (e.g., a TXS trigger frame) is mainly described, but the present disclosure is not limited thereto, and other frames, etc. may be used.

Here, the relay STA can perform CCA in 20MHz units for the BW that received the PPDU including the TXS trigger frame and transmit the CTS frame using one or more idle 20MHz channel(s).

For example, the BW for the 20MHz channel(s) over which the CTS is transmitted may be less than or equal to the BW over which the relay STA received the PPDU containing the TXS trigger frame.

Additionally, for example, a PPDU including a CTS frame transmitted by a relay STA may be configured to include the same punctured 20MHz channel(s) reflecting disallowed channel information/inactive sub-channels information of the AP.

On the other hand, the addressed/identified destination STA(s) that have received the TXS trigger frame for relay communication from the AP may not transmit a response thereto to the AP. That is, among the STAs that have received the TXS trigger frame for relay communication, only the relay STA identified/designated through the user information field of the TXS trigger frame may transmit a CTS frame as a response, and the destination STA(s) addressed/identified by the remaining user information fields may check the information about the time shared by the AP for relay communication, but may not transmit a response frame thereto.

Unlike the proposed method described above, whether or not to transmit a response frame (e.g., a CTS frame) to a TXS trigger frame (i.e., by the relay STA and/or destination STA(s)) can be explicitly transmitted/indicated by the AP. The information about the above can be included and transmitted in a user information field. For example, a response required field can be defined in the user information field, thereby indicating whether a response is required. For example, when the response required field is set to 0, it can indicate that a CTS frame is not transmitted (not required) as a response after receiving a TXS trigger frame, and conversely, when the response required field is set to 1, it indicates that a CTS frame is transmitted (required) as a response after receiving a TXS trigger frame. In addition, it can be set to an opposite value.

Here, if the Response Request field is set to 0, the RU Allocation subfield included in the User Information field may be ignored or reserved.

Therefore, for example, when an AP transmits a TXS trigger frame, the user information field can be configured by setting the value of the Response Request field in the user information field for the relay STA to 1, and the user information field can be configured by setting the value of the Response Request field in the user information field for the destination STA(s) to 0.

A relay STA that has verified the shared time information through the above-mentioned (addressed) user information field can ignore the NAV set by the AP during the corresponding time period (e.g., not perform a NAV setting update).

Additionally, during UL relay communication, the destination STA(s) that have confirmed the shared time information through the above-mentioned (addressed) user information field can ignore the NAV set by the AP during the corresponding time period (e.g., not perform a NAV setting update).

An AP that receives a PPDU including a CTS frame from a relay STA can transmit a signal or data (e.g., a signal or data to be transmitted to a destination STA) for relay communication to the relay STA using the BW in which the received PPDU was transmitted.

A relay STA that receives a signal or data from an AP can transmit an ACK frame to the AP, and then, after a certain period of time (e.g., SIFS), transmit the signal/data to destination STAs using the same BW as the BW through which the signal/PPDU was received from the AP.

FIG. 14 is a diagram illustrating a procedure for TXOP sharing and bandwidth determination for relay communication according to one embodiment of the present disclosure.

Referring to FIG. 14, the AP can transmit a TXS trigger frame using an 80MHz channel BW for relay communication. Here, as in the example of FIG. 14, the fourth order 20MHz subchannel included in the 80MHz BW can be transmitted by being punctured (i.e., puncturing pattern [0 0 0 1]).

A relay STA that receives a TXS trigger frame transmitted by an AP can perform CCA on the remaining 20MHz channels except for the punctured channel (i.e., the 20MHz subchannel of the 4th order) for the PPDU BW (80MHz) that received the TXS trigger frame to check for idle channels. As shown in FIG. 14, the relay STA performs CCA on the remaining 20MHz channels except for the 20MHz channel of the 4th order, and uses the 60MHz channels (i.e., the 20MHz subchannels of the first, second, and third orders) that are determined to be idle channels except for the 20MHz channel determined to be busy as a result of the CCA to transmit a PPDU including a CTS frame as a response (e.g., after SIFS). An AP that receives a CTS frame from the relay STA can transmit a signal/data to the relay STA using the received punctured 80MHz (e.g., after SIFS).

A relay STA that receives a signal/data from an AP can transmit an ACK frame to the AP (e.g., after SIFS). After that (e.g., after SIFS), the relay STA can transmit a signal/data to the destination STA using the same BW (i.e., the punctured 80MHz).

In Fig. 14, the 80MHz bandwidth and the preamble puncturing pattern are just an example for the convenience of explanation, and the present disclosure is not limited thereto. That is, the proposed method of the present invention can perform relay communication by considering 20/40/80/160/320MHz and various preamble puncturing patterns defined in 802.11be, and the operating BW for relay communication can be determined using the proposed method described above.

Example 2-2) As another example, the relay STA and destination STA(s) that have received a PPDU including a TXS trigger frame for relay communication from the AP can transmit a response frame (e.g., a CTS (Clear-To-Send) frame) in response thereto.

In the following description of the present disclosure, for convenience of explanation, the case in which a CTS frame is responded in response to a frame (e.g., a TXS trigger frame) carrying information about a shared time or TXOP for relay communication is mainly described, but the present disclosure is not limited thereto, and other frames, etc. may also be used.

Here, the CTS frame can be transmitted through a 20MHz channel allocated through an allocation subfield included in a user information field of a received TXS trigger frame. That is, the relay STA and destination STA(s) can transmit the CTS frame as a response frame by using the 20MHz channel allocated to them within the BW covered by the PPCU including the TXS trigger frame.

In addition, as described above, the relay STA and destination STA(s) can know information about the time interval shared by the AP through the user information field included in the TXS trigger frame, and can use the information about the time interval to ignore the NAV setting set by the AP for (during) the shared time interval (e.g., not performing a NAV setting update).

The AP can obtain information about STAs that have received (i.e., successfully received) a TXS trigger frame through the 20MHz channel(s) through which the CTS frame was transmitted within the BW, and can obtain information about STAs participating in relay communication.

An AP that receives a response frame from a relay STA and destination STA(s) may transmit a signal/data to the relay STA in order to perform relay communication for the destination STA(s) that transmitted the response frame. Here, a PPDU including a signal/data that the AP transmits to the relay STA may be transmitted using the same bandwidth covered by a PPDU including a TXS trigger frame transmitted by the AP. If the bandwidth covered by the PPDU including the TXS trigger frame transmitted by the AP includes preamble puncturing, the same preamble puncturing pattern may be identically applied to the bandwidth used for signal transmission of the relay STA.

FIG. 15 is a diagram illustrating a procedure for TXOP sharing and bandwidth determination for relay communication according to one embodiment of the present disclosure.

Referring to FIG. 15, the AP can transmit a PPDU including a TXS trigger frame using an 80MHz channel BW for TXOP sharing for relay communication. Here, as in the example of FIG. 15, the PPDU including the TXS trigger frame can be transmitted to the relay STA and destination STA(s) using a punctured 80MHz channel (in the case of FIG. 15, the 20MHz channel of the third order is punctured).

The addressed/identified relay STA and the addressed/identified destination STA(s) that have received the TXS trigger frame transmitted by the AP can obtain information about the allocated time interval (i.e., the time interval allocated for relay communication) through the received TXS trigger frame and information about the 20MHz channel allocated for transmission of the response frame.

The addressed/identified relay STA can ignore the NAV set by the AP during the allocated time interval by using the information about the allocated time interval that it has figured out (for example, by not performing a NAV configuration update). In addition, during UL relay communication, the addressed/identified destination STA(s) can ignore the NAV set by the AP during the allocated time interval by using the information about the allocated time interval that it has figured out through the received TXS trigger frame (for example, by not performing a NAV configuration update).

After receiving the TXS trigger frame, the addressed STA(s) (i.e., relay STA and destination STA(s)) can transmit a CTS frame to the AP using the information about the 20MHz channel allocated to them. The AP can check the information about the STAs participating in the relay communication through the 20MHz subchannel where the CTS frame is received within the bandwidth for the PPDU including the TXS trigger frame.

An AP receiving a CTS frame can transmit a signal/data for relay communication to the relay STA using the operating BW used for transmitting a PPDU including a TXS trigger frame. That is, the signal/data can be transmitted to the relay STA using a punctured 80 MHz channel (i.e., in the example of FIG. 15, the 20 MHz subchannel of the third order is punctured). Here, the signal and data can be configured for the destination STA(s) that transmitted the CTS frame to the AP as a response to the TXS trigger frame. That is, even if it is a destination STA addressed in the TXS trigger frame, data/signal for a destination STA that does not transmit a CTS frame to the AP as a response to the TXS trigger frame can be excluded (i.e., excluding relay communication).

A relay STA that receives a signal/data from an AP can transmit an ACK frame to the AP (e.g., after SIFS). After that (e.g., after SIFS), the relay STA can transmit a signal/data to the destination STA using the same BW (i.e., the punctured 80MHz).

Example 2-3) As another example, the addressed/identified destination STA(s) that have received the TXS trigger frame transmitted by the AP may transmit a response frame (e.g., a CTStoself frame) to itself rather than to the AP as a response to the received TXS trigger frame.

In the following description of the present disclosure, for convenience of explanation, the case in which a CTStoself frame is responded to in response to a frame (e.g., a TXS trigger frame) carrying information about a shared time or TXOP for relay communication is mainly described, but the present disclosure is not limited thereto, and other frames, etc. may also be used.

An STA located near the destination STA or receiving the self-CTS frame transmitted by the destination STA sets a NAV (i.e., updates the NAV setting) using the self-CTS frame to perform protection for signal transmission and reception during the corresponding period, and can also reduce interference during relay communication from the AP to a hidden STA.

FIG. 16 is a diagram illustrating a procedure for TXOP sharing and bandwidth determination for relay communication according to one embodiment of the present disclosure.

Referring to FIG. 16, the AP can transmit a PPDU including a TXS trigger frame using an 80MHz channel BW for TXOP sharing for relay communication. Here, as in the example of FIG. 16, the PPDU including the TXS trigger frame can be transmitted to the relay STA and destination STA(s) using a punctured 80MHz channel (in the case of FIG. 16, the 20MHz channel of the third order is punctured).

The addressed/identified relay STA and the addressed/identified destination STA(s) that have received the TXS trigger frame transmitted by the AP can obtain information about the allocated time interval (i.e., the time interval allocated for relay communication) through the received TXS trigger frame.

The addressed/identified relay STA can ignore the NAV set by the AP during the allocated time interval by using the information about the allocated time interval that it has figured out (for example, by not performing a NAV configuration update). In addition, during UL relay communication, the addressed/identified destination STA(s) can ignore the NAV set by the AP during the allocated time interval by using the information about the allocated time interval that it has figured out through the received TXS trigger frame (for example, by not performing a NAV configuration update).

The self-CTS frame transmitted by the destination STA(s) may be transmitted in the same BW as the transmitted PPDU in which the TXS trigger frame is transmitted, or may be transmitted using an idle 20MHz channel(s) within the BW of the transmitted PPDU including the TXS trigger frame.

On the other hand, a relay STA that receives a TXS trigger frame from an AP can transmit a CTS frame to the AP in response to the received TXS trigger frame.

The CTS frame transmitted by the relay STA may be transmitted in the same BW as the PPDU in which the TXS trigger frame is transmitted, or may be transmitted using an idle 20MHz channel(s) within the BW of the PPDU transmitted including the TXS trigger frame.

As another example, the CTS frame may also be transmitted using the RU/channel allocated via the TXS trigger frame.

An AP that receives a CTS frame can transmit a signal/data for relay communication to the relay STA using the operating BW used for transmitting a PPDU including a TXS trigger frame. That is, the signal/data can be transmitted to the relay STA using a punctured 80 MHz channel (i.e., in the case of the example of FIG. 16, the 20 MHz subchannel of the third order is punctured). Here, the signal and data can be configured for the destination STA(s) addressed by the TXS trigger frame.

A relay STA that receives a signal/data from an AP can transmit an ACK frame to the AP (e.g., after SIFS). After that (e.g., after SIFS), the relay STA can transmit a signal/data to the destination STA using the same BW (i.e., the punctured 80MHz).

Meanwhile, in the above-described embodiments 1 and 2 (embodiments 2-1, 2-2, and 2-3), the BW capabilities of the destination STAs participating in the relay communication may be different from each other. Accordingly, if the destination STA participating in the relay communication does not support a large bandwidth (large BW) (i.e., the bandwidth of the PPDU carrying the TXS trigger frame or the bandwidth of the PPDU carrying the data/signal transmitted from the relay STA), the relay STA can perform signal/data transmission using a BW suitable for the BW capability of the destination STA. For example, if 80MHz BW is used for signal transmission and reception between the AP and the destination STA after exchanging/transmitting/receiving TXS trigger frames, but the BW capability of the destination STA(s) participating in the relay communication is 40MHz, the relay STA can transmit and receive signals/data with the destination STA using 40MHz BW.

That is, in the embodiments 1 and 2 (embodiments 2-1, 2-2, and 2-3) described above, the BW used by the relay STA to transmit a frame/signal/data to the destination STA(s) may be equal to or smaller than the BW used by the AP to transmit a frame/signal/data to the relay STA.

FIG. 17 illustrates the operation of a first station for a method for relay operation according to one embodiment of the present disclosure.

FIG. 17 illustrates the operation of a first STA device (e.g., a relay STA device) based on the proposed methods. The example of FIG. 17 is provided for convenience of explanation and does not limit the scope of the present disclosure. Some of the step(s) illustrated in FIG. 17 may be omitted depending on the situation and/or setting.

Referring to FIG. 17, the first STA device receives a trigger frame from the AP device (S1701). That is, the first STA device receives a PPDU including/carrying a trigger frame from the AP device.

The above trigger frame may include time information for a time interval set for relay operation within the TXOP acquired by the AP.

The bandwidth of the above trigger frame (i.e., the PPDU containing/carrying the trigger frame) may be punctured in one or more 20 MHz subchannels.

Although not shown in FIG. 17, the first STA device may transmit a response frame to the trigger frame to the AP device. That is, the first STA device may transmit a PPDU including/carrying a response frame to the trigger frame to the AP device.

Here, based on the 20MHz unit clear channel assessment (CCA) by the first STA, the response frame (i.e., the PPDU containing/carrying the response frame) may be transmitted over one or more idle 20MHz subchannels.

Additionally, the response frame (i.e., the PPDU containing/carrying the response frame) may be transmitted at a bandwidth that is equal to or less than the bandwidth for the trigger frame (i.e., the PPDU containing/carrying the trigger frame).

For example, the trigger frame may include a special user information field, and the special user information field may include at least one of an instruction for relay communication, an instruction for uplink or downlink for relay communication.

For example, the trigger frame may include one user information field for the first STA, and the user information field may include the time information.

As another example, the trigger frame may include user information fields for the first STA and the second STA, and the time information may be composed of information about a time interval per STA allocated to each STA specified by each of the user information fields.

Here, each of the user information fields may include information indicating whether transmission of a response frame to the trigger frame is required.

Additionally, a response frame to the trigger frame (i.e., a PPDU containing/carrying the response frame) may be transmitted over a 20 MHz subchannel allocated by each of the user information fields.

Additionally, the first STA may ignore the NAV setting set by the AP for the time period (in other words, may not update the NAV setting even if the trigger frame is received).

The first STA device receives data for the second STA device from the AP device within the time interval (S1702). That is, the first STA device receives a PPDU including/carrying data for the second STA from the AP device.

Here, the data (i.e., the PPDU containing/carrying the data) may be transmitted at a bandwidth equal to or less than the bandwidth for the trigger frame (i.e., the PPDU containing/carrying the trigger frame).

The first STA device transmits the data to the second STA within the time interval (S1703). That is, the first STA device transmits a PPDU including/carrying the data to the second STA within the time interval.

Here, the data (i.e., the PPDU containing/carrying the data) may be transmitted at a bandwidth equal to or less than the bandwidth for the trigger frame (i.e., the PPDU containing/carrying the trigger frame).

In steps S1701 to S1703, a PPDU including/carrying a trigger frame, a response frame, or data may be configured to include a legacy part, a SIG part (e.g., U-SIG, UHR-SIG, etc.), an STF part (e.g., UHR-STF), an LTF part (e.g., UHR-LTF), and a data part.

All or part of any part (i.e., field) may be divided into multiple sub-parts/sub-fields. Each field (and its sub-fields) may be transmitted in units of 4us * N (N is an integer). In addition, a guard interval (GI) may be included. A common subcarrier frequency spacing value (delta_f=312.5 kHz / N or 312.5 kHz * N, where N=integer) may be applied to all of the fields, or a first delta_f may be applied to the first part (e.g., all of legacy part, all/part of SIG part), and a second delta_f (e.g., a value smaller than the first delta_f) may be applied to all/part of the remaining parts.

Some of the fields described above may be omitted, and the order of the fields may be changed in various ways. For example, the subfields of the signal part may be placed before the STF part, and the remaining subfields of the SIG part may be placed after the STF part.

The above-described legacy part may include at least one of a conventional L-STF (Non-HT Short Training Field), L-LTF (Non-HT Long Training Field), and L-SIG (Non-HT Signal Field).

The above-mentioned SIG-part (e.g., including the U-SIG field, UHR-SIG field, etc.) may include various control information for the transmitted PPDU. For example, it may include the STF-part, the LTF-part, and control information for decoding data.

The STF-part described above (e.g., the U-STF field) may contain an STF sequence.

The above-described LTF-part (e.g., U-LTF field) may include a training field (i.e., LTF sequence) for channel estimation.

The data-part described above may include user data and may include packets for upper layers (e.g., MPDUs).

The method described in the example of FIG. 17 may be performed by the first device (100) of FIG. 1. For example, one or more processors (102) of the first device (100) of FIG. 1 may be configured to perform PPDU exchange with other devices via the transceiver(s) (106). Furthermore, one or more memories (104) of the first device (100) may store commands for performing the method described in the example of FIG. 17 or the examples described above when executed by one or more processors (102).

FIG. 18 illustrates the operation of an access point for a method for relay operation according to one embodiment of the present disclosure.

Fig. 18 illustrates the operation of an AP device based on the previously proposed methods. The example of Fig. 18 is provided for convenience of explanation and does not limit the scope of the present disclosure. Some of the step(s) illustrated in Fig. 18 may be omitted depending on the situation and/or setting.

Referring to FIG. 18, the AP device transmits a trigger frame to the first STA device (S1801). That is, the AP device transmits a PPDU including/carrying the trigger frame to the first STA.

The above trigger frame may include time information for a time interval set for relay operation within the TXOP acquired by the AP.

The bandwidth of the above trigger frame (i.e., the PPDU containing/carrying the trigger frame) may be punctured in one or more 20 MHz subchannels.

Although not shown in FIG. 18, the AP device may receive a response frame to the trigger frame from the first STA device. That is, the AP device may receive a PPDU including/carrying a response frame to the trigger frame from the first STA device.

Here, based on the 20MHz unit clear channel assessment (CCA) by the first STA, the response frame (i.e., the PPDU containing/carrying the response frame) may be transmitted over one or more idle 20MHz subchannels.

Additionally, the response frame (i.e., the PPDU containing/carrying the response frame) may be transmitted at a bandwidth that is equal to or less than the bandwidth for the trigger frame (i.e., the PPDU containing/carrying the trigger frame).

For example, the trigger frame may include a special user information field, and the special user information field may include at least one of an instruction for relay communication, an instruction for uplink or downlink for relay communication.

For example, the trigger frame may include one user information field for the first STA, and the user information field may include the time information.

As another example, the trigger frame may include user information fields for the first STA and the second STA, and the time information may be composed of information about a time interval per STA allocated to each STA specified by each of the user information fields.

Here, each of the user information fields may include information indicating whether transmission of a response frame to the trigger frame is required.

Additionally, a response frame to the trigger frame (i.e., a PPDU containing/carrying the response frame) may be transmitted over a 20 MHz subchannel allocated by each of the user information fields.

Additionally, the first STA may ignore the NAV setting set by the AP for the time period (in other words, may not update the NAV setting even if the trigger frame is received).

The AP device transmits data for the second STA device to the first STA device within the time interval (S1802). That is, the AP device transmits a PPDU including/carrying data for the second STA to the first STA device.

Here, the data (i.e., the PPDU containing/carrying the data) may be transmitted at a bandwidth equal to or less than the bandwidth for the trigger frame (i.e., the PPDU containing/carrying the trigger frame).

Thereafter, the first STA device transmits the data to the second STA within the time interval. That is, the first STA device transmits a PPDU including/carrying the data to the second STA within the time interval.

Here, the data (i.e., the PPDU containing/carrying the data) may be transmitted at a bandwidth equal to or less than the bandwidth for the trigger frame (i.e., the PPDU containing/carrying the trigger frame).

In steps S1801 to S1702, a PPDU including/carrying a trigger frame, a response frame, or data may be configured to include a legacy part, a SIG part (e.g., U-SIG, UHR-SIG, etc.), an STF part (e.g., UHR-STF), an LTF part (e.g., UHR-LTF), and a data part.

All or part of any part (i.e., field) may be divided into multiple sub-parts/sub-fields. Each field (and its sub-fields) may be transmitted in units of 4us * N (N is an integer). In addition, a guard interval (GI) may be included. A common subcarrier frequency spacing value (delta_f=312.5 kHz / N or 312.5 kHz * N, where N=integer) may be applied to all of the fields, or a first delta_f may be applied to the first part (e.g., all of legacy part, all/part of SIG part), and a second delta_f (e.g., a value smaller than the first delta_f) may be applied to all/part of the remaining parts.

Some of the fields described above may be omitted, and the order of the fields may be changed in various ways. For example, the subfields of the signal part may be placed before the STF part, and the remaining subfields of the SIG part may be placed after the STF part.

The above-described legacy part may include at least one of a conventional L-STF (Non-HT Short Training Field), L-LTF (Non-HT Long Training Field), and L-SIG (Non-HT Signal Field).

The above-mentioned SIG-part (e.g., including the U-SIG field, UHR-SIG field, etc.) may include various control information for the transmitted PPDU. For example, it may include the STF-part, the LTF-part, and control information for decoding data.

The STF-part described above (e.g., the U-STF field) may contain an STF sequence.

The above-described LTF-part (e.g., U-LTF field) may include a training field (i.e., LTF sequence) for channel estimation.

The data-part described above may include user data and may include packets for upper layers (e.g., MPDUs).

The method described in the example of FIG. 18 may be performed by the second device (200) of FIG. 1. For example, one or more processors (202) of the second device (200) of FIG. 1 may be configured to perform PPDU exchange with other devices via the transceiver(s) (206). Furthermore, one or more memories (204) of the second device (200) may store commands for performing the method described in the example of FIG. 18 or the examples described above when executed by one or more processors (202).

A method for setting a time interval to support a relay operation for an STA outside the coverage of an AP in a conventional wireless LAN system has not been defined. In contrast, according to the method for relay operation according to examples of the present disclosure, by setting a time interval for the relay operation within a TXOP acquired by an AP, transmission and reception of signals/data can be protected through relay transmission and interference to hidden STAs can be reduced, thereby achieving the effect of efficiently performing relay transmission and increasing wireless communication efficiency.

The embodiments described above are combinations of components and features of the present disclosure in a given form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented in a form that is not combined with other components or features. In addition, it is also possible to combine some components and/or features to form an embodiment of the present disclosure. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in another embodiment, or may be replaced with corresponding components or features of another embodiment. It is obvious that claims that do not have an explicit citation relationship in the scope of the patent may be combined to form an embodiment or may be included as a new claim by post-application amendment.

It will be apparent to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential characteristics of the present disclosure. Accordingly, the above detailed description should not be construed as limiting in all respects but should be considered as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all changes within the equivalent scope of the present disclosure are intended to be included in the scope of the present disclosure.

The scope of the present disclosure includes software or machine-executable instructions (e.g., an operating system, an application, firmware, a program, etc.) that cause operations according to the various embodiments to be executed on a device or a computer, and a non-transitory computer-readable medium having such software or instructions stored thereon and executable on the device or computer. Instructions that can be used to program a processing system to perform the features described in the present disclosure can be stored on/in a storage medium or a computer-readable storage medium, and a computer program product including such a storage medium can be used to implement the features described in the present disclosure. The storage medium can include, but is not limited to, high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid state memory devices, and can include non-volatile memory, such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid state storage devices. The memory optionally includes one or more storage devices remotely located from the processor(s). The memory or alternatively the non-volatile memory device(s) within the memory comprises a non-transitory computer-readable storage medium. The features described in this disclosure may be incorporated into software and/or firmware stored on any one of the machine-readable media to control the hardware of the processing system and to allow the processing system to interact with other mechanisms that utilize results according to embodiments of the present disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments/containers.

The method proposed in this disclosure has been described with a focus on examples applied to IEEE 802.11-based systems, but can be applied to various wireless LANs or wireless communication systems in addition to IEEE 802.11-based systems.

Claims (17)

A step of receiving a trigger frame from an access point (AP), by a first station (STA: station), wherein the trigger frame includes time information for a time interval set for relay operation within a transmission opportunity (TXOP: transmission opportunity) acquired by the AP; A step of receiving data for a second STA from the AP within the time interval by the first STA; and A method comprising the step of transmitting the data to the second STA within the time interval by the first STA. In the first paragraph, A method wherein the bandwidth over which the above trigger frame is transmitted is punctured in one or more 20 MHz subchannels. In the second paragraph, A method further comprising the step of transmitting, by the first STA, a response frame to the trigger frame to the AP. In the third paragraph, A method wherein, based on a 20MHz unit clear channel assessment (CCA) by the first STA, the response frame is transmitted through one or more idle 20MHz subchannels. In paragraph 4, A method wherein the above response frame is transmitted at a bandwidth equal to or less than a bandwidth for the above trigger frame. In the second paragraph, A method wherein the above data is transmitted at a bandwidth equal to or less than a bandwidth for the trigger frame. In the first paragraph, The above trigger frame contains a special user information field, A method wherein the special user information field includes at least one of an instruction for relay communication, an instruction for uplink or downlink for relay communication. In the first paragraph, The above trigger frame includes one user information field for the first STA, A method wherein the user information field includes the time information. In the first paragraph, The above trigger frame includes user information fields for the first STA and the second STA, A method wherein the above time information is composed of information about a time interval for each STA allocated to each STA specified by each of the above user information fields. In Article 9, A method wherein each of the above user information fields includes information indicating whether transmission of a response frame to the trigger frame is required. In Article 9, A method wherein a response frame to the above trigger frame is transmitted through a 20MHz subchannel allocated by each of the above user information fields. In the first paragraph, A method in which the first STA ignores a network allocation vector (NAV) setting set by the AP for the time period. The first station (STA: station) device is: one or more transmitters and receivers; and comprising one or more processors coupled to said one or more transceivers; One or more of the above processors: Receive a trigger frame from an access point (AP), wherein the trigger frame includes time information on a time interval for relay operation within a transmission opportunity (TXOP) acquired by the AP; Receive data for the second STA within the time period for the relay operation from the AP, and A first STA device configured to transmit the data to the second STA within a time period for the relay operation. A step of transmitting a trigger frame to a first station (STA: station) by an access point (AP: access point), wherein the trigger frame includes time information on a time interval for relay operation within a transmission opportunity (TXOP: transmission opportunity) acquired by the AP; and A method comprising the step of transmitting data for a second STA to the first STA within a time period for the relay operation by the first AP. The access point (AP) device: one or more transmitters and receivers; and comprising one or more processors coupled to said one or more transceivers; One or more of the above processors: Transmitting a trigger frame to a first station (STA: station), wherein the trigger frame includes time information on a time interval for relay operation within a transmission opportunity (TXOP: transmission opportunity) acquired by the AP, and An AP device configured to transmit data for a second STA to the first STA within a time period for the relay operation. In a processing device configured to control a station (STA: station) in a wireless LAN system, the processing device: one or more processors; and A processing device comprising one or more computer memories operatively connected to said one or more processors and storing instructions that, when executed by said one or more processors, perform a method according to any one of claims 1 to 12. One or more non-transitory computer-readable media storing one or more instructions, A computer-readable medium, wherein said one or more commands are executed by one or more processors to control a device in a wireless LAN system to perform a method according to any one of claims 1 to 12.

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