Method and device for performing uplink transmission / reception operation on basis of trigger frame in wireless LAN system

Abstract

A method and a device for operating in a wireless LAN system are disclosed. The method according to one embodiment of the present disclosure comprises steps in which a first station (STA): receives, from a second STA, a trigger frame including an intermediate frame check sequence (FCS) field; and transmits, to the second STA, a response frame based on the trigger frame, wherein a common information field of the trigger frame includes a first field related to whether the intermediate FCS field is included in the trigger frame, and the intermediate FCS field can be included in at least one user information field of the trigger frame.

Description

Method and device for performing uplink transmission and reception operations based on trigger frames in a wireless LAN system

[0001] The present disclosure relates to a method and device for performing an uplink transmission and reception operation based on a trigger frame in a wireless local area network (WLAN) system.

[0002] New technologies have been introduced for wireless local area networks (WLANs) to improve transmission rates, increase bandwidth, enhance reliability, reduce errors, and reduce latency. Among WLAN technologies, the IEEE (Institute of Electrical and Electronics Engineers) 802.11 series of standards can be referred to as Wi-Fi. For example, recently introduced technologies for WLANs include enhancements for Very High Throughput (VHT) in the 802.11ac standard and enhancements for High Efficiency (HE) in the IEEE 802.11ax standard.

[0003] To provide a more advanced wireless communication environment, improved technologies for Extremely High Throughput (EHT) are being discussed. For example, technologies for Multiple Input Multiple Output (MIMO), which supports increased bandwidth, efficient utilization of multiple bands, and increased spatial streams, and for coordination of multiple access points (APs), are being studied. 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 technology.

[0004] The technical problem of the present disclosure relates to a method and device for transmitting and receiving traffic in a wireless LAN system.

[0005] The technical problem of the present disclosure relates to a method and device for performing an uplink transmission and reception operation based on a trigger frame including an intermediate FCS field in a wireless LAN system.

[0006] 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.

[0007] A method according to one embodiment of the present disclosure comprises the steps of: receiving, by a first station (STA), a trigger frame including an immediate frame check sequence (FCS) field from a second STA; and transmitting, by the first STA, a response frame based on the trigger frame to the second STA, wherein a common information field of the trigger frame includes a first field related to whether the intermediate FCS field is included in the trigger frame, and the intermediate FCS field can be included in at least one user information field of the trigger frame.

[0008] A method according to one embodiment of the present disclosure comprises the steps of: transmitting a trigger frame including an immediate frame check sequence (FCS) field by a second station (STA) to a first STA; and receiving a response frame based on the trigger frame from the first STA by the second STA, wherein a common information field of the trigger frame includes a first field related to whether the intermediate FCS field is included in the trigger frame, and the intermediate FCS field can be included in at least one user information field of the trigger frame.

[0009] According to various embodiments of the present disclosure, a method and device for transmitting and receiving traffic in a wireless LAN system can be provided.

[0010] According to various embodiments of the present disclosure, a method and device for performing an uplink transmission and reception operation based on a trigger frame including an intermediate FCS field in a wireless LAN system can be provided.

[0011] The effects that can be obtained from the present disclosure are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by a person having ordinary skill in the art to which the present disclosure pertains from the description below.

[0012] The accompanying drawings, which are incorporated in and are part of the detailed description 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.

[0013] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0014] FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0015] FIG. 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

[0016] FIG. 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0017] FIG. 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0018] 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.

[0019] FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0020] FIG. 8 is a drawing showing an exemplary format of a trigger frame to which the present disclosure can be applied.

[0021] FIG. 9 is a flowchart for explaining the operation of the first STA according to one embodiment of the present disclosure.

[0022] FIG. 10 is a flowchart for explaining the operation of a second STA according to one embodiment of the present disclosure.

[0023] FIG. 11 is a diagram for explaining the configuration of a trigger frame including an intermediate FCS and the operation of an STA supporting DPS according to one embodiment of the present disclosure.

[0024] FIG. 12 is a diagram for explaining the operation of an STA supporting DSO according to one embodiment of the present disclosure.

[0025] FIG. 13 is a diagram for explaining the operation of an STA that supports integrity check of a trigger frame according to one embodiment of the present disclosure.

[0026] FIG. 14 and FIG. 15 are drawings for explaining the configuration of an intermediate FCS field according to one embodiment of the present disclosure.

[0027] Hereinafter, preferred embodiments of 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 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.

[0028] In some cases, to avoid obscuring the concepts of the present disclosure, known structures and devices may be omitted or illustrated in block diagram form focusing on the core functions of each structure and device.

[0029] 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 but also an indirect connection in which another component exists between them. Furthermore, 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.

[0030] In this disclosure, terms such as “first,” “second,” etc. are used only to distinguish one component from another and are not used to limit the components, and do not limit the order or importance between 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.

[0031] The terminology used herein is for the purpose of describing particular embodiments 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 any 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 use of " / " between words in this disclosure has the same meaning as "and / or" unless otherwise stated.

[0032] 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 the 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 the newly proposed IEEE 802.11bn (or UHR) standard. Additionally, the examples of the present disclosure can be applied to a wireless LAN based on the next-generation standard after IEEE 802.11bn. Furthermore, 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 the LTE (Long Term Evolution) series of technologies and the 5G NR (New Radio) series of technologies of the 3rd Generation Partnership Project (3GPP) standard.

[0033] Below, technical features to which examples of the present disclosure can be applied are described.

[0034] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0035] 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 WTRU (Wireless Transmit Receive Unit), a UE (User Equipment), an MS (Mobile Station), a UT (user terminal), an MSS (Mobile Subscriber Station), an MSS (Mobile Subscriber Unit), an SS (Subscriber Station), an AMS (Advanced Mobile Station), a WT (Wireless terminal), 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 BS (Base Station), a fixed station, a Node B, a BTS (Base Transceiver System), a network, an AI (Artificial Intelligence) system, an RSU (road side unit), a repeater, a router, a relay, a gateway, etc.

[0036] 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 transmitting device, receiving device, transmitting STA, and receiving STA. For example, the STAs (110, 200) may perform an AP (access point) role or a non-AP role. That is, in the present disclosure, the STAs (110, 200) may perform the 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, in the present disclosure, the APs may also be referred to as AP STAs.

[0037] 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 provisions of the IEEE 802.11 standard.

[0038] In addition, the first device (100) and the second device (200) may additionally support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, 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 AR (Augmented Reality) device, a VR (Virtual Reality) device, etc. In addition, the STA of the present specification may support various communication services such as voice calls, video calls, data communications, autonomous driving, MTC (Machine-Type Communication), M2M (Machine-to-Machine), D2D (Device-to-Device), and IoT (Internet-of-Things).

[0039] A first device (100) includes one or more processors (102) and one or more memories (104), and may further include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memories (104) and / or the transceivers (106), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. For example, the processor (102) may process information in the memories (104) to generate first information / signals, and then transmit a wireless signal including the first information / signals via the transceivers (106). Furthermore, the processor (102) may receive a wireless signal including second information / signals via the transceivers (106), and then store information obtained from signal processing of the second information / signals in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may perform some or all of the processes controlled by the processor (102), or may store software code 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.

[0040] The second device (200) includes one or more processors (202), one or more memories (204), and may further include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memories (204) and / or the transceivers (206), and may be configured to implement the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure. For example, the processor (202) may process information in the memory (204) to generate third information / signals, and then transmit a wireless signal including the third information / signals via the transceivers (206). Furthermore, the processor (202) may receive a wireless signal including fourth information / signals via the transceivers (206), and then store information obtained from signal processing of the fourth information / signals in the memory (204). The memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, the memory (204) may perform some or all of the processes controlled by the processor (202), or may store software code including instructions for performing the descriptions, functions, procedures, proposals, methods, and / or operation 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.

[0041] Hereinafter, the 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 the present 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 the present 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, proposals and / or methods disclosed in the present 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, proposals, methods and / or operational flowcharts disclosed in the present disclosure.

[0042] One or more processors (102, 202) may be referred to as a controller, a microcontroller, a microprocessor, or a microcomputer. 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 one or more processors (102, 202). The descriptions, functions, procedures, proposals, 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, proposals, methods and / or operation flowcharts disclosed in this disclosure may be implemented using firmware or software configured to perform one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods and / or operation flowcharts disclosed in this disclosure may be implemented using firmware or software in the form of codes, instructions and / or sets of instructions.

[0043] 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 configured as 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.

[0044] 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, proposals, 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, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure, via one or more antennas (108, 208). In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can 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 user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0045] 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 in which various STAs generate transmission and reception signals or perform 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 transmission / reception signal or performing data processing or operation in advance for a transmission / reception signal may include 1) an operation for determining / obtaining / 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 / obtaining time resources or frequency resources (e.g., subcarrier resources) used for a field (SIG, STF, LTF, Data, etc.) included in a PPDU, 3) an operation for determining / configuring / obtaining a specific sequence (e.g., a pilot sequence, an STF / LTF sequence, an extra sequence applied to SIG) used for a field (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 / obtaining / configuring / computing / decoding / encoding an ACK signal, etc. Additionally, 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.

[0046] Hereinafter, downlink (DL) refers to a link for communication from an AP STA to a non-AP STA, and downlink PPDUs / packets / signals, etc. can be transmitted and received through the downlink. In downlink communication, the transmitter may be part of an AP STA, and the receiver may be part of a non-AP STA. Uplink (UL) refers to a link for communication from a non-AP STA to an AP STA, and uplink PPDUs / packets / signals, etc. can be transmitted and received through the uplink. In uplink communication, the transmitter may be part of a non-AP STA, and the receiver may be part of an AP STA.

[0047] FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0048] The structure of a wireless LAN system can be composed of multiple components. Through the interaction of multiple components, a wireless LAN that supports transparent STA mobility to the upper layer can be provided. A Basic Service Set (BSS) corresponds to a basic building block of a wireless LAN. FIG. 2 illustrates, by way of example, the existence of two BSSs (BSS1 and BSS2) and the inclusion of two STAs as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). The oval 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 Basic Service Area (BSA). When an STA moves outside of a BSA, it cannot directly communicate with other STAs within the BSA.

[0049] If we do not consider the DS illustrated in Figure 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 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. Such a configuration is possible when the STAs can communicate directly without an AP. Furthermore, in this type of WLAN, 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 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.

[0050] An STA's membership in a BSS can dynamically change, for example, when an STA is turned on or off, or when an STA enters or leaves a BSS area. To become a member of a BSS, an STA can join the BSS using a synchronization process. To access all services in the BSS infrastructure, an STA must be associated with the BSS. This association can be dynamically established and may involve the use of a Distribution System Service (DSS).

[0051] In a wireless LAN, the direct STA-to-STA distance can be limited by PHY performance. While this distance limit may be sufficient in some cases, communication between STAs over longer distances may be required in other cases. To support extended coverage, a distributed system (DS) can be configured.

[0052] 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 illustrated in Figure 2. DS is a logical concept and can be specified by the characteristics of a distributed system medium (DSM). In this regard, the Wireless Medium (WM) and DSM can be logically distinguished. Each logical medium is used for a different purpose and by different components. These media are neither limited to being identical nor limited to being different. This logical difference between multiple media explains the flexibility of the WLAN architecture (DS architecture or other network architectures). In other words, the WLAN architecture can be implemented in various ways, and the physical characteristics of each implementation can independently specify the WLAN architecture.

[0053] A DS can support mobile devices by providing seamless integration of multiple BSSs and the logical services necessary to handle addresses to destinations. Additionally, a DS may further include a component called a portal, which acts as a bridge for connecting wireless LANs to other networks (e.g., IEEE 802.X).

[0054] 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 the function of allowing 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 do not necessarily have to be the same. A BSS consisting of an AP and one or more STAs can be referred to as an infrastructure BSS.

[0055] Data transmitted from one of the STA(s) associated with an AP to the STA address of that AP may always be received on an uncontrolled port and processed by an IEEE 802.1X port access entity. In addition, if the controlled port is authenticated, the transmitted data (or frame) may be forwarded to the DS.

[0056] In addition to the structure of the DS described above, an extended service set (ESS) may be established to provide wider coverage.

[0057] An ESS is a network of arbitrary size and complexity, consisting of DSs and BSSs. 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 appearing as an IBSS at the Logical Link Control (LLC) layer. STAs within an ESS can communicate with each other, and mobile STAs can move from one BSS to another (within the same ESS) transparently to the LLC. APs within an ESS may have the same SSID (service set identification). The SSID is distinct from the BSSID, which is the identifier of the BSS.

[0058] In a wireless LAN system, no assumptions are made about the relative physical locations of BSSs, and all of the following configurations are possible: BSSs can be partially overlapping, which is commonly used to provide continuous coverage. BSSs can also be physically disconnected, and there is no logical distance limit between them. BSSs can also be physically co-located, which can be used to provide redundancy. Furthermore, one (or more) IBSS or ESS networks can physically co-exist with one (or more) ESS networks. This can occur in cases where an ad-hoc network operates at the same location as an ESS network, where physically overlapping wireless networks are configured by different organizations, or where two or more different access and security policies are required at the same location.

[0059] FIG. 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

[0060] For an STA to set up a link and transmit and receive data on a network, it must first discover the network, perform authentication, establish an association, and complete security authentication procedures. The link setup process can also be referred to as the session initiation process or session setup process. Furthermore, the discovery, authentication, association, and security setup processes of the link setup process can be collectively referred to as the association process.

[0061] In step S310, the STA may perform a network discovery operation. This network discovery operation may include scanning operations by the STA. That is, for the STA to access a network, it must search for available networks. Before joining a wireless network, the STA must identify compatible networks. The process of identifying networks in a specific area is called scanning.

[0062] Scanning methods include active scanning and passive scanning. Figure 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 discover any APs in the vicinity while moving between channels and waits for a response. The responder transmits a probe response frame in response to the STA that transmitted the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame in the BSS of the channel being scanned. In the BSS, the AP transmits the beacon frame, so the AP becomes the responder. 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 requests / responses on channel 2) in the same manner.

[0063] Although not shown in Figure 3, the scanning operation can also be performed in a passive scanning manner. In passive scanning, the STA performing the scanning moves between channels and waits for a beacon frame. A beacon frame is one of the management frames defined in IEEE 802.11. It announces the existence of a wireless network and is periodically transmitted so that the STA performing the scanning can find the wireless network and participate in the wireless network. In the BSS, the AP performs the role of periodically transmitting the beacon frame, and in the IBSS, the STAs within the IBSS take turns transmitting the beacon frame. When the STA performing the scanning receives a beacon frame, it stores the information about the BSS included in the beacon frame and moves to another channel, recording the beacon frame information on each channel. The STA receiving the beacon frame stores the BSS-related information included in the received beacon frame and moves to the next channel to perform 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.

[0064] After the STA discovers the network, an authentication process may be performed in step S320. This authentication process may be referred to as the first authentication process to clearly distinguish it from the security setup operation of step S340 described below.

[0065] The authentication process involves the STA sending an authentication request frame to the AP, and the AP responding by sending an authentication response frame to the STA. The authentication frame used for the authentication request / response corresponds to a management frame.

[0066] 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), and a Finite Cyclic Group. These are just some examples of information that may be included in an authentication request / response frame, and may be replaced with other information or include additional information.

[0067] An STA can send an authentication request frame to an AP. The AP can determine whether to grant authentication to the STA based on the information contained in the received authentication request frame. The AP can provide the result of the authentication process to the STA via an authentication response frame.

[0068] 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.

[0069] 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, an RSN, a mobility domain, 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., an association comeback time), overlapping BSS scan parameters, a TIM broadcast response, a Quality of Service (QoS) map, etc. These are just some examples of information that may be included in a combined request / response frame, and may be replaced by other information or include additional information.

[0070] After the STA successfully joins the network, a security setup process may be performed in step S340. The security setup process in step S340 may be referred to as an authentication process through a Robust Security Network Association (RSNA) request / response, the authentication process in step S320 may be referred to as a first authentication process, and the security setup process in step S340 may also be referred to simply as an authentication process.

[0071] The security setup process of step S340 may include, for example, a process of establishing a private key through a four-way handshaking using an Extensible Authentication Protocol over LAN (EAPOL) frame. Furthermore, the security setup process may be performed according to a security method not defined in the IEEE 802.11 standard.

[0072] FIG. 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0073] In wireless LAN systems, the basic access mechanism of MAC (Medium Access Control) is Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA). The CSMA / CA mechanism, also known as the Distributed Coordination Function (DCF) of the IEEE 802.11 MAC, essentially employs a "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 before attempting to transmit frames. By applying a random backoff period, multiple STAs are expected to attempt to transmit frames after waiting for different periods of time, thereby minimizing collisions.

[0074] In addition, the IEEE 802.11 MAC protocol provides the 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 that periodically polls all receiving APs and / or STAs to ensure that they receive data frames. In addition, the HCF has the Enhanced Distributed Channel Access (EDCA) and the HCF Controlled Channel Access (HCCA). The EDCA is a contention-based access method for a provider to provide data frames to multiple users, while the HCCA uses a non-contention-based channel access method that utilizes a polling mechanism. In addition, the HCF includes a medium access mechanism to improve the Quality of Service (QoS) of the wireless LAN, and can transmit QoS data in both the Contention Period (CP) and the Contention Free Period (CFP).

[0075] Referring to Fig. 4, an operation based on a random backoff period is described. When a medium that was occupied / busy changes to an idle state, multiple STAs can attempt to transmit data (or frames). To minimize collisions, each STA can select a random backoff count, wait for the corresponding slot time, and then attempt transmission. The random backoff count has a pseudo-random integer value and can 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 given an initial value of CWmin, but can take a doubled value in case of transmission failure (e.g., when an ACK for a transmitted frame is not received). When the CW parameter value becomes CWmax, data transmission can 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. The CW, CWmin, and CWmax values ​​are 2. n It is desirable to set it to -1 (n=0, 1, 2, ...).

[0076] Once the random backoff process begins, 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. When the medium becomes idle, the remaining countdown resumes.

[0077] In the example of FIG. 4, when a packet to be transmitted reaches the MAC of STA3, STA3 can immediately transmit a frame if it confirms that the medium is idle for DIFS. The remaining STAs monitor the medium for occupied / busy states and wait. In the meantime, data to be transmitted may also occur in each of STA1, STA2, and STA5, and each STA can count down the backoff slot according to a random backoff count value selected by each STA after waiting for DIFS if 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 counting down and wait while STA2 occupies the medium. When STA2's occupation ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and then resume the backoff count that they had stopped. That is, they can start transmitting frames after counting down the remaining backoff slots equal to the remaining backoff time. Since STA5's remaining backoff time is shorter than STA1's, STA5 starts transmitting frames. 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, counts down according to its selected random backoff count value, and then starts transmitting frames. In the example of Figure 4, the remaining backoff time of STA5 coincidentally matches the random backoff count value of STA4, in which 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 can start transmitting frames after the remaining backoff time elapses.

[0078] 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 elapses, such as DIFS or PIFS (Point coordination function IFS). Subtype frames of a 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 Request-To-Send (RTS), Clear-To-Send (CTS), Acknowledgment (ACK), Power Save-Poll (PS-Poll), Block ACK (BlockAck), Block ACK Request (BlockACKReq), Null Data Packet Announcement (NDP), and Trigger. If the control frame is not a response frame to the previous frame, it is transmitted after a backoff performed after the DIFS (Direct Inverse Frame Stop) has elapsed, and if it is a response frame to the previous frame, it is transmitted without a 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.

[0079] 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, i.e., 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.

[0080] FIG. 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0081] As mentioned above, the CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing, in which STAs directly sense the medium. Virtual carrier sensing is intended to address potential issues in medium access, such as the hidden node problem. For virtual carrier sensing, the MAC of an STA can utilize a Network Allocation Vector (NAV). The NAV is a value that an STA that is currently using or has the right to use the medium indicates to other STAs the remaining time until the medium becomes available. Therefore, the value set as NAV corresponds to the period during which the STA transmitting the frame is scheduled to use the medium, and an STA receiving the NAV value is prohibited from accessing the medium during that period. For example, the NAV can be set based on the value of the "duration" field in the MAC header of the frame.

[0082] 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 some or all of the frames transmitted and received between STA1 and STA2.

[0083] In order to reduce the possibility of collisions in 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 medium is idle based on carrier sensing results. That is, STA1 may correspond to a hidden node for STA3. Alternatively, in the example of FIG. 5, while STA2 is transmitting, STA3 may determine that the medium is idle based on carrier sensing results. That is, STA2 may correspond to a hidden node for STA3. By exchanging RTS / CTS frames before performing data transmission and reception between STA1 and STA2, STAs outside the transmission range of either STA1 or STA2, or STAs outside the carrier sensing range for transmissions from STA1 or STA3, may not attempt to occupy the channel during data transmission and reception between STA1 and STA2.

[0084] Specifically, STA1 can determine whether a channel is occupied through carrier sensing. In terms of physical carrier sensing, STA1 can determine channel occupancy idleness based on the energy level or signal correlation detected in the channel. Furthermore, in terms of virtual carrier sensing, STA1 can determine the channel occupancy status using a network allocation vector (NAV) timer.

[0085] STA1 can transmit an RTS frame to STA2 after performing a backoff if the channel is idle during the DIFS. STA2 can transmit a CTS frame, which is a response to the RTS frame, to STA1 after an SIFS if it receives the RTS frame.

[0086] If STA3 cannot overhear a CTS frame from STA2 but can overhear an RTS frame from STA1, STA3 can use the duration information contained in the RTS frame to set a NAV timer for the subsequent consecutively transmitted frame transmission period (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame). Alternatively, if STA3 cannot overhear an RTS frame from STA1 but can overhear a CTS frame from STA2, STA3 can use the duration information contained in the CTS frame to set a NAV timer for the subsequent consecutively transmitted frame transmission period (e.g., SIFS + data frame + SIFS + ACK 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. If STA3 receives a new frame before the NAV timer expires, it can update the NAV timer using the duration information contained in the new frame. STA3 does not attempt channel access until the NAV timer expires.

[0087] If STA1 receives a CTS frame from STA2, it can transmit a data frame to STA2 after SIFS from the time when the CTS frame is completely received. 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 another terminal during the DIFS after the NAV timer expires, it can attempt channel access after a contention window (CW) based on a random backoff has elapsed.

[0088] 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.

[0089] The PHY layer can prepare an MPDU (MAC PDU) to be transmitted based on 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 the information (e.g., data) provided by 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.

[0090] 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.

[0091] 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 the Legacy-STF (L-STF), Legacy-LTF (L-LTF), Legacy-SIG (L-SIG) fields, 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 is HT, VHT, HE, EHT, etc.)) may be included between the L-SIG field and the data field. More specific details will be described later with reference to FIG. 7.

[0092] STF is a signal for signal detection, AGC (Automatic Gain Control), diversity selection, and precise time synchronization, while LTF is a signal for channel estimation, frequency error estimation, etc. STF and LTF can be said to be signals for synchronization and channel estimation of the OFDM physical layer.

[0093] 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 the 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.

[0094] 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 to synchronize the descrambler at the receiving end. The PSDU corresponds to a MAC PDU defined at the MAC layer and may contain data generated / used by upper layers. The PPDU TAIL bit may be used to return the encoder to a 0 state. The padding bit may be used to adjust the length of the data field to a predetermined unit.

[0095] MAC PDUs are defined according to various MAC frame formats, and a basic MAC frame consists of a MAC header, a frame body, and a Frame Check Sequence (FCS). A MAC frame is composed of MAC PDUs and can be transmitted / received through the PSDU in the data portion of the PPDU format.

[0096] 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 the receiver address, transmitter address, destination address, and 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.

[0097] The Null-Data PPDU (NDP) format refers to a PPDU format that does not include a data field. In other words, NDP refers to a frame format that includes a PPDU preamble (i.e., L-STF, L-LTF, L-SIG fields, and, if additionally present, non-legacy SIG, non-legacy STF, and non-legacy LTF) in the general PPDU format, and does not include the remaining part (i.e., data field).

[0098] FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0099] Standards such as IEEE 802.11a / g / n / ac / ax use various PPDU formats. 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 referred to as the non-HT PPDU format (Fig. 7(a)).

[0100] The HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT(s) fields in addition to 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, but consists of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTF, and Data fields (not illustrated).

[0101] An example of the 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)).

[0102] 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 addition to 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 the HE PPDU format for multi-users (MUs), but the HE PPDU format for single users (SUs) does not include the HE-SIG-B. In addition, the HE trigger-based (TB) PPDU format does not include the HE-SIG-B, and the length of the HE-STF field may vary to 8us. The 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 determine that the received PPDU is a HE PPDU or an EHT PPDU, described later, based on the presence of RL-SIG.

[0103] 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 may include a U (universal)-SIG, an EHT-SIG, an EHT-STF, and an EHT-LTF following the RL-SIG.

[0104] The EHT MU PPDU in FIG. 7(e) corresponds to a PPDU that carries one or more data (or PSDUs) 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.

[0105] The EHT TB PPDU of Fig. 7(f) omits the 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.

[0106] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal SIGNAL), and EHT-SIG fields can be encoded and modulated to allow legacy STAs to attempt demodulation and decoding, and mapped based on a predetermined subcarrier frequency interval (e.g., 312.5 kHz). These can be referred to as pre-EHT modulated fields. Next, the EHT-STF, EHT-LTF, Data, and PE fields can be encoded and modulated to allow STAs that have successfully decoded non-legacy SIGs (e.g., U-SIG and / or EHT-SIG) and obtained the information contained in the fields, and mapped based on a predetermined subcarrier frequency interval (e.g., 78.125 kHz). These can be referred to as EHT modulated fields.

[0107] 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.

[0108] 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 4 us, and the U-SIG can have a total duration of 8 us. 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.

[0109] U-SIGs can be configured in 20MHz units. For example, when an 80MHz PPDU is configured, the same U-SIG can be duplicated 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-SIGs in the first 80MHz unit and the U-SIGs in the second 80MHz unit can be different.

[0110] For example, A uncoded bits may be transmitted via U-SIG, and a first symbol of U-SIG (e.g., a U-SIG-1 symbol) may transmit the first X bits of information out of a total A bits of information, and a second symbol of U-SIG (e.g., a U-SIG-2 symbol) may transmit the remaining Y bits of information out of a total A bits of information. The A bits of information (e.g., 52 uncoded bits) may include a CRC field (e.g., a field of 4 bits in length) and a tail field (e.g., a field of 6 bits in length). The tail field may be used to terminate the trellis of the convolutional decoder and may be set to 0, for example.

[0111] The A bit information transmitted by U-SIG can be divided into version-independent bits and version-dependent bits. For example, U-SIG can 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 can be the same, and some or all of the version-dependent bits can be different.

[0112] 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.

[0113] For example, the version-independent bits of the 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 PPDUs. The version-independent bits of the U-SIG may include a 1-bit UL / DL flag field. The first value of the 1-bit UL / DL flag field relates to UL communication, and the second value of the UL / DL flag field relates to DL communication. The version-independent bits of the U-SIG may include information about the length of a transmission opportunity (TXOP) and information about a BSS color ID.

[0114] For example, the version-dependent bits of the U-SIG may contain information that directly or indirectly indicates the type of PPDU (e.g., SU PPDU, MU PPDU, TB PPDU, etc.).

[0115] 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 the MCS technique applied to the non-legacy SIG (e.g., EHT-SIG or UHR-SIG), information indicating whether a dual carrier modulation (DCM) technique (e.g., a technique to achieve 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 across the entire band, etc.

[0116] Some of the information required for transmitting and receiving a PPDU 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 the 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) applicable to the non-legacy LTF, information about preamble puncturing applicable to the PPDU, information about 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.

[0117] Preamble puncturing may refer to the transmission of a PPDU in which no signal is present in one or more frequency units within the PPDU's bandwidth. 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 certain size.

[0118] In the example of FIG. 7, non-legacy SIGs such as HE-SIG-B and EHT-SIG may include control information for the receiving STA. The non-legacy SIG may be transmitted over at least one symbol, and each symbol may have a length of 4 us. Information regarding the number of symbols used for the EHT-SIG may be included in a previous SIG (e.g., HE-SIG-A, U-SIG, etc.).

[0119] Non-legacy SIGs, such as HE-SIG-B and EHT-SIG, may contain common fields and user-specific fields. Common and user-specific fields may be coded separately.

[0120] In some cases, common fields may be omitted. For example, in a compressed mode where non-OFDMA (orthogonal frequency multiple access) is applied, common fields may be omitted, and multiple STAs may receive PPDUs (e.g., data fields of PPDUs) over the same frequency band. In a non-compressed mode where OFDMA is applied, multiple users may receive PPDUs (e.g., data fields of PPDUs) over different frequency bands.

[0121] The number of user-specific fields can be determined based on the number of users. A single user block field can contain up to two user fields. Each user field can be associated with either MU-MIMO allocation or non-MU-MIMO allocation.

[0122] The common field may include CRC bits and Tail bits, the length of the CRC bits may be determined as 4 bits, and the length of the Tail bits may be determined as 6 bits and 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.

[0123] An RU can contain multiple subcarriers (or tones). RUs can be used when transmitting signals to multiple STAs based on OFDMA techniques. RUs can also be defined when transmitting signals to a single STA. Resources can be allocated on an RU basis for non-legacy STFs, non-legacy LTFs, and data fields.

[0124] Depending on the PPDU bandwidth, an applicable RU size 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 the case of an 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 low bandwidth tone plan.

[0125] RUs of different sizes can be defined, such as 26-ton RU, 52-ton RU, 106-ton RU, 242-ton RU, 484-ton RU, 996-ton RU, 2X996-ton RU, 3X996-ton RU, etc. A multiple RU (MRU) is distinguished 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-tons, 106+26-tons, 484+242-tons, 996+484-tons, 996+484+242-tons, 2X996+484-tons, 3X996-tons, or 3X996+484-tons. Additionally, multiple RUs constituting one MRU may or may not be consecutive in the frequency domain.

[0126] The specific size of an 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. Furthermore, within a given bandwidth (e.g., 20, 40, 80, 160, 320 MHz, etc.) in the present disclosure, the number of RUs may vary depending on the RU size.

[0127] 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 those names. Furthermore, 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.

[0128] FIG. 8 is a drawing showing an exemplary format of a trigger frame to which the present disclosure can be applied.

[0129] A trigger frame may allocate resources for the transmission of one or more TB PPDUs and request the transmission of TB PPDUs. The trigger frame may also include other information required by the STA transmitting the TB PPDU in response. The trigger frame may include common information and a user information list field in the frame body.

[0130] The common information field may include information that is common to one or more TB PPDU transmissions requested by a 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. Fig. 8 illustrates an example of an EHT variant common information field format.

[0131] 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, Beamforming Report Poll (BFRP), multi user-block acknowledgement request (MU-BAR), multi user-request to send (MU-RTS), Buffer Status Report Poll (BSRP), groupcast with retries (GCR), MU-BAR, Bandwidth Query Report Poll (BQRP), and NDP Feedback Report Poll (NFRP), respectively, and the values ​​8 to 15 are defined as reserved.

[0132] Among the common information, the trigger dependent common info subfield may include information that is optionally included based on the trigger type.

[0133] 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 extended common information not provided in the common information field.

[0134] A user information list contains zero or more user information fields. Figure 8 illustrates an example of an EHT variant user information field format.

[0135] The AID12 subfield basically indicates that it is a user information field for an STA with 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 information field. The special user information field is a user information field that does not contain user-specific information, but contains extended common information not provided in the common information field. For example, the special user information field can be identified by the AID12 value of 2007, and the special user information field flag subfield within the common information field can indicate whether the special user information field is included.

[0136] The RU allocation subfield can indicate the size and location of an 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.

[0137] FCS Field

[0138] The FCS field may contain a 32-bit CRC. The FCS field value may be computed over the entire field of the MAC header and the frame body field. The above-described field(s) may also be expressed as a computed field. The FCS field value is expressed as a 32-order standard generating polynomial (e.g., x 32 + x 26 + x 23 + x 22 + x 16 + x 12 + x 11 + x 10 + x 9 + x 7 + x 5 + x 4 + x 2 + x 1+ 1) can be used to produce the result.

[0139] The FCS field value can be the 1's complement (modulo 2) of the following sums:

[0140] a) x k (x 31 + x 30 + x 29 + ... + x 2 + x 1 + 1) is the remainder (modulo 2) of dividing G(x), where k represents the number of bits in the computation field; and

[0141] b) The contents of the calculated field (processed as a polynomial) are x 32 It is the remainder after multiplying by and dividing by G(x).

[0142] The FCS field can be transmitted starting with the coefficient of the highest-order term. In a typical implementation, the transmitter can preset all division remainders to 1, then modify the calculation field by dividing it by the generating polynomial G(x). The 1's complement of this remainder can be transmitted as the FCS field, with the most significant bit first.

[0143] At the receiver, all initial remainders are preset to 1, and the serially received bits of the computed field and the FCS can be divided by G(x) to produce a unique non-zero remainder (in the absence of transmission errors). This unique remainder can be a polynomial such that:

[0144] x 31 + x 30 + x 26 + x 25 + x 24 + x 18 + x 15 + x 14 + x 12 + x 11 + x 10 + x 8 + x 6 + x 5 + x 4 + x 3 + x +1.

[0145] Uplink transmission procedure based on trigger frame

[0146] A padding field may optionally be included in the trigger frame described with reference to FIG. 8, thereby extending the length of the trigger frame. For example, if a padding field is included in the trigger frame, the padding field (e.g., time secured through the padding field) may provide time for the STA that has received the trigger frame to prepare UL MU data to be transmitted (e.g., PPDU to be transmitted SIFS after receiving the trigger frame).

[0147] For example, the value of the AID12 subfield located at the beginning of the padding field may be set to 4095 so that an STA that has received a trigger frame can recognize the padding field after the user information list field within the padding field of the trigger frame. That is, the initial 2 octet value of the padding field may be set to 1.

[0148] In a basic wireless LAN system, a receiving STA (e.g., an EHT STA) can perform an FCS check operation (e.g., a CRC (Cyclic Redundancy Check)-based operation) based on the value of the FCS field located after the padding field of the trigger frame. Thereafter, the receiving STA can transmit a PPDU based on the trigger frame to the transmitting STA that transmitted the trigger frame.

[0149] An STA that wishes to perform other operations as well as generate / prepare UL MU data within the time corresponding to the padding field must confirm that the trigger frame is a successful frame based on the FCS field of the trigger frame. However, as described above, in a basic wireless LAN system, the FCS field is placed after the padding field within the trigger frame. In other words, the time period corresponding to the padding field is before the FCS check operation is performed, and thus the STA may not be able to perform other operations within that time period.

[0150] Accordingly, there was a problem that the location of the FCS field on the basic wireless LAN system was inefficient for STAs supporting DPS (dynamic power save), integrity check for control frames, DSO (dynamic Subband operation), or / and DUO (dynamic unavailability operation) mode.

[0151] Hereinafter, the procedures and parameters related to a new FCS (sub)field placed before a padding field within a trigger frame will be specifically described. In describing the present disclosure, the new FCS (sub)field may be expressed as, but is not limited to, an intermediate FCS (sub)field, an IFCS (sub)field, an FCS 2 (sub)field, a pre-FCS (sub)field, an extra FCS (sub)field, a post FCS (sub)field, etc.

[0152] The values, names, (sub)field locations / names, etc. described / suggested within the present disclosure may be changed and are not limited thereto. In addition, STAs may include non-AP STAs or AP STAs, etc. In addition, in describing the present disclosure, it is assumed, but not limited thereto, that UHR STAs are STAs that support DPS, integrity check for control frames (e.g., trigger frames), DSO and / or DUO mode, etc.

[0153] Additionally, in describing the present disclosure, a trigger frame supporting DPS, integrity check for control frames, DSO and / or DUO mode, etc. may include the (sub)fields shown in FIG. 8 and / or a new FCS (sub)field.

[0154] FIG. 9 is a flowchart illustrating the operation of a first STA according to an embodiment of the present disclosure. In FIGS. 9 and 10 , each of the first STA and the second STA may be either a non-AP STA or an AP. In addition, in FIGS. 9 and 10 , it is assumed, but not limited to, that the first STA or / and the second STA are STAs (e.g., UHR STAs) that support DPS, integrity check for control frames (e.g., trigger frames), DSO and / or DUO mode.

[0155] The first STA can receive a trigger frame including an intermediate FCS field from the second STA (S910).

[0156] Here, the intermediate FCS may include a computed CRC, and the computed field may include all fields of the MAC header and frame body field up to and including the field containing the intermediate FCS field. The length of the intermediate FCS field may be, but is not limited to, 32 bits.

[0157] For example, the common information field of a trigger frame (e.g., a trigger frame used as an ICF, etc.) may include a first field (e.g., an IFCS presence flag subfield) related to whether an intermediate FCS field is included (or present) in the trigger frame. For example, the first field may be set on the 61st bit (B60) of the common information field of the trigger frame (e.g., a UHR variant common information field).

[0158] For example, based on the first field value being set to 0 (or 1), this may mean / indicate that an intermediate FCS field exists on the trigger frame. Based on the first field value being set to 1 (or 0), this may mean / indicate that an intermediate FCS field does not exist on the trigger frame. In the following, it is assumed, but is not limited to, that the first field indicates that an intermediate FCS field is included on the trigger frame.

[0159] For example, a trigger frame may include a padding field and a separate FCS field. In this case, the padding field may be placed immediately after the middle FCS field within the trigger frame. Furthermore, the FCS field may be placed immediately after the padding field within the trigger frame. In other words, the padding field may be placed after the middle FCS field, and the FCS field may be placed after the padding field.

[0160] In addition, the intermediate FCS field may be included in at least one user information field of the trigger frame. For example, the intermediate FCS field may be included in a single user information field of the trigger frame, or may be divided and included in multiple trigger frames. In this case, the trigger frame may include information related to whether the intermediate FCS field is included in a single user information field or multiple user information fields. In other words, the trigger frame may include information indicating whether it is set in a single user information field or divided and set in multiple user information fields.

[0161] For example, assume that an intermediate FCS field is included in a single user information field (e.g., a first user information field). For example, the first user information field may include a first association identifier (AID)12 subfield and an intermediate FCS field. In this case, the intermediate FCS field may be positioned immediately after the AID12 subfield within the first user information field. In addition, the first AID12 subfield may be set to a value related to the intermediate FCS field (e.g., a value indicating that an intermediate FCS field exists on the first user information field). The first STA may perform an FCS check operation based on the value of the intermediate FCS included in the intermediate FCS field (e.g., a CRC value).

[0162] Additionally or alternatively, it is assumed that the intermediate FCS field is included in multiple user information fields. Below, the intermediate FCS field is described as being divided and set / arranged into two user information fields (e.g., a second user information field and a third user information field), but is not limited thereto. The method described below can also be applied when the intermediate FCS field is divided and set / arranged into three or more user information fields.

[0163] As described above, it is assumed that at least one user information field includes a second user information field and a third user information field. In this case, the first bit (e.g., a CRC value corresponding to the first bit) of the intermediate FCS field may be included in the second user information field, and the second bit (e.g., a CRC value corresponding to the second bit) of the intermediate FCS field may be included in the third user information field.

[0164] For example, the first bit may be 24 bits long and the second bit may be 8 bits long, but is not limited thereto. The first bit may be y bits long and the second bit may be 32-y bits long.

[0165] At this time, each of the second user information field and the third user information field may include an AID12 subfield, and each of the AID12 subfields may be placed / set before the first / second bit of the intermediate FCS field. Each of the AID12 subfields may be set to a value indicating that the first / second bit of the intermediate FCS field is included in the corresponding user information field (e.g., the second / third user information field).

[0166] For example, the first STA may concatenate a first cyclic redundancy check (CRC) value set for the first bit and a second CRC value set for the second bit, and perform an FCS check operation based on the first CRC value and the second CRC value.

[0167] As an example of the present disclosure, the intermediate FCS field may include i) a second AID12 subfield including an intermediate FCS-1 subfield (e.g., a first partial intermediate FCS field) and ii) an intermediate FCS-2 subfield (e.g., a second partial intermediate FCS field). The intermediate FCS-1 subfield may have a length of 12-n bits (where n is a natural number less than or equal to 8), and one of the n bits in the second AID12 subfield may be set to 0. The FCS-2 subfield may be positioned immediately after the n bits in the second AID12 subfield, and a value set in the n bits in the second AID12 subfield may be a value associated with the intermediate FCS field. Additionally or alternatively, the FCS-2 subfield may be positioned immediately after the n bits in the second AID12 subfield, and the second AID12 subfield (e.g., a value of the second AID12 subfield) may be based on a range including one or more values. For example, the value of the second AID12 subfield may be defined as a range including one or more values ​​rather than a specific value.

[0168] The examples described above can be applied both when the intermediate FCS field is divided into a single user information field and / or when multiple user information fields are placed.

[0169] As an example of the present disclosure, before or after step S910, the first STA may transmit a frame including a dynamic power save (DPS) padding delay field to the second STA. Based on a value in the DPS padding delay field (e.g., a value indicated based on the DPS padding delay field) being greater than a time value for the first STA to process a trigger frame (e.g., "MinTrigProcTime" and / or "EMLSR / EMLMR padding (or transition delay value"), the time value for processing the trigger frame may be replaced with the value in the DPS padding delay field. Here, the EMLSR / EMLMR padding delay value may correspond to a delay time that occurs when a link is switched.

[0170] The first STA can transmit a response frame based on the trigger frame to the second STA (S920).

[0171] Specifically, if the result of the FCS check based on the intermediate FCS field is successful, the first STA may perform operations such as DPS, integrity check for the trigger frame, UL MU data preparation, and / or DSO during the padding time. For example, the first STA may not perform additional FCS check operations in the FCS field after the padding field. Here, the response frame may include a response frame (or response PPDU) (e.g., a frame including ICR, UL MU data) related to DPS, integrity check for the trigger frame, UL MU data preparation, and / or DSO.

[0172] Additionally or alternatively, if the result of the FCS check based on the intermediate FCS field is a failure, the first STA may perform an additional FCS check operation via the FCS field after the padding time of the padding field.

[0173] The method described in the example of FIG. 9 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 receive a trigger frame including an intermediate FCS field from a second STA through one or more transceivers (106). The one or more processors (102) may transmit a response frame based on the trigger frame to the second STA through one or more transceivers (106).

[0174] Furthermore, one or more memories (104) of the first device (100) may store commands for performing the method described in the example of FIG. 9 or the examples described below when executed by one or more processors (102).

[0175] FIG. 10 is a flowchart for explaining the operation of a second STA according to one embodiment of the present disclosure.

[0176] The second STA can transmit a trigger frame including an intermediate FCS field to the first STA (S1010).

[0177] Prior to step S1010, the second STA may determine whether the first STA supports the DPS operation, the integrity check operation for the trigger frame, and / or the DSO operation during the padding time of the trigger frame. For example, the second STA may receive capability information from the first STA regarding whether the second STA supports the DPS operation, the integrity check operation for the trigger frame, and / or the DSO operation during the padding time.

[0178] In the following, it is assumed, but not limited to, that the first STA supports DPS operation, integrity check operation for the trigger frame, and / or DSO operation during the padding time of the trigger frame.

[0179] The second STA can generate a trigger frame including an intermediate FCS field and then transmit it to the first STA. The configuration of the trigger frame has been described with reference to FIG. 9, so a redundant description will be omitted.

[0180] The second STA can receive a response frame based on the trigger frame from the first STA (S1020).

[0181] The method described in the example of FIG. 10 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 transmit a trigger frame including an intermediate FCS field to a first STA via one or more transceivers (206). One or more processors (102) may receive a response frame based on the trigger frame from the first STA via one or more transceivers (160).

[0182] Furthermore, one or more memories (204) of the second device (200) may store instructions for performing the method described in the example of FIG. 10 or the examples described below when executed by one or more processors (202).

[0183] Below, we will specifically describe the operation based on the intermediate FCS field, the configuration of the intermediate FCS field, the configuration of a trigger frame including the intermediate FCS field, and the method for determining the length of the padding field within the trigger frame.

[0184] Example 1

[0185] Example 1 relates to an operation based on an intermediate FCS (sub)field.

[0186] As an example of the present disclosure, if an intermediate FCS (sub)field is included before a padding field of a trigger frame, an STA supporting DPS (e.g., a UHR STA) may perform an FCS check operation based on the intermediate FCS field. In addition, the STA may perform an operation of switching from a low capability bandwidth (e.g., 20 MHz) to a high capability bandwidth (e.g., 80 MHz) during a padding time of the padding field of the trigger frame (e.g., a time period corresponding to the padding field).

[0187] For example, as illustrated in (a) of FIG. 11, the STA may operate in a low capability bandwidth and mode (e.g., listening mode) while decoding the frame control field of the trigger frame to the middle FCS field. After performing an FCS check based on the middle FCS field, the STA may switch the listening mode to a mode associated with a high capability bandwidth (e.g., power mode) during the padding time of the padding field. Accordingly, the STA may perform an operation of checking CCA based on SIFS on the TXOP bandwidth, as illustrated in (b) of FIG. 11.

[0188] Specifically, as illustrated in (b) of FIG. 11, a receiving STA (e.g., a DPS-enabled STA) may receive an MU-RTS frame (e.g., an initial control frame (ICF)) from a transmitting STA (e.g., a DPS-supporting STA). At this time, the mode of the receiving STA may be a listening mode, and the listening mode may collectively refer to a mode capable of performing (receiving) capability-based operations related to a low bandwidth (e.g., 20 MHz).

[0189] A receiving STA may switch from a listening mode to a power mode during the padding time of the padding field of an MU-RTS frame, and may transmit a CTS frame (e.g., an initial control response (ICR)) to the transmitting STA as a response to the MU-RTS frame within the power mode. Here, the power mode may collectively refer to a mode capable of performing (receiving) capability-based operations related to a high bandwidth (e.g., 80 MHz).

[0190] Additionally or alternatively, as illustrated in FIG. 12, assume that a middle FCS (sub)field is included before the padding field of the trigger frame. A DSO-enabled STA (e.g., a UHR STA) may perform an FCS check operation based on the middle FCS field of a trigger frame (e.g., a BSRP frame or ICF) transmitted by a DSO-enabled STA. In this case, the trigger frame may be transmitted and received on the primary 80 MHz and the secondary 80 MHz.

[0191] In addition, a DSO-enabled STA can perform an operation of switching from the primary 80 MHz to the secondary 80 MHz during the padding time of the padding field. Accordingly, the DSO-enabled STA can transmit a response frame (e.g., BSR or ICR) to a DSO-supporting STA on the secondary 80 MHz, and the primary 80 MHz can be used for data transmission of other STAs (which do not support DSO).

[0192] Additionally or alternatively, as illustrated in FIG. 13, if there is information(s) (e.g., key ID, MIC, PN, etc.) for integrity check of the trigger frame and an intermediate FCS (sub)field before the padding field of the trigger frame, the STA (e.g., receiving STA) may perform an FCS check through the intermediate FCS (sub)field. Then, the STA may verify the validity of the information for integrity check of the trigger frame and / or perform a UL MU data generation / preparation operation based on the trigger frame during the padding time of the padding field.

[0193] Additionally or alternatively, if a middle FCS (sub)field of a trigger frame exists before the padding field of the trigger frame (e.g., a BSRP trigger frame, etc.), an STA (e.g., an STA supporting DUO) may perform an FCS check through the middle FCS (sub)field. Then, the STA may perform DUO-related operations during the padding time of the padding field.

[0194] Here, DUO mode may refer to a mode in which wireless LAN signals / data cannot be transmitted based on transmission / reception operations based on non-Wi-Fi technologies (e.g., Bluetooth (BT), Zigbee, UWB (Ultra-wideband), etc.). DUO-related operations may include encoding / decoding of information related to DUO mode / events, signaling operations of information related to DUO mode / events, etc.

[0195] Example 2

[0196] Example 2 relates to a method for indicating the presence or absence of a new FCS (sub)field (or intermediate FCS field) in a trigger frame.

[0197] An STA (e.g., a UHR STA) can determine whether an intermediate FCS (sub)field exists within a trigger frame through the value of the intermediate FCS present subfield. That is, the intermediate FCS present subfield can indicate whether an intermediate FCS (sub)field exists / is placed before a padding field within a trigger frame.

[0198] For example, the intermediate FCS presence subfield may be set / defined via a reserved subfield within the trigger frame. For example, the intermediate FCS presence subfield may be set / defined on at least one bit among the 23rd bit (B22), the 27th bit (B26), the 54th bit (B54), and the 64th bit (B63) of the common information field of the trigger frame. As another example, the intermediate FCS presence subfield may be set / defined on at least one bit among the reserved bits (e.g., the 38th bit (B37) to the 40th bit (B39)) within the special user information field of the trigger frame.

[0199] Example 3

[0200] Example 3 relates to a method for setting the value of a new FCS (sub)field. The method and length of configuring the new FCS (sub)field described in the present disclosure may be identical to the method and length of configuring the value of the FCS field included at the end of the MPDU configuration of a basic wireless LAN.

[0201] That is, the value of the intermediate FCS (sub)field can be set to a value for the CRC for the portion corresponding to the MAC header and frame body of the MPDU. For example, the intermediate FCS (sub)field can be set to a value for the CRC-32 (e.g., x 32 + x 26 + x 23 + x 22 + x 16 + x 12 + x 11 + x 10 + x 9 + x 7+ x 5 + x 4 + x 2 + x 1 + 1) and may have a length of 4 octets (e.g., 32 bits). Hereinafter, the present disclosure is described assuming that the configuration and value of the intermediate FCS (sub)field are 4 octets in length, but is not limited thereto.

[0202] Additionally or alternatively, the method and length of configuring the new FCS (sub)field may not be the same as the method and length of configuring the FCS field included at the end of the MPDU configuration of the basic wireless LAN system. That is, the value of the intermediate FCS (sub)field may be set to a value for a CRC for a portion corresponding to the MAC header and frame body of the MPDU. In this case, the intermediate FCS (sub)field may be configured based on a CRC of N bits shorter than 32 bits rather than CRC-32. Here, N may be, but is not limited to, 24, 16, 8, or 4. The primary FCS (sub)field value for the CRC for the MAC header and frame body within the trigger frame may be calculated according to Example 3-1.

[0203] Additionally or alternatively, depending on the value of N bits including 32 bits, reserved bits or / and bit(s) indicating additional information(s) may be used to align the length of the intermediate FCS (sub)field with the length in octets or the length of the FCS field of the underlying wireless LAN system.

[0204] Example 3-1

[0205] Example 3-2 relates to a CRC-N polynomial associated with an intermediate FCS (sub)field. Here, N can be 24 bits, 21 bits, 17 bits, 16 bits, 15 bits, 14 bits, 13 bits, 12 bits, 11 bits, 10 bits, 8 bits, 7 bits, 6 bits, 5 bits, 4 bits, 3 bits, or 1 bit.

[0206] For example, if N is 24 bits, the value of the intermediate FCS (sub)field can be calculated based on CRC-24, or CRC-24-Radix-64, CRC-24-WCDMA, etc.:

[0207] - CRC-24 : x 24 + x 22 + x 20 + x 19 + x 18 + x 16 + x 14 + x 13 + x 11 + x 10 + x 8 + x 7 + x 6 + x 3 + x 1 + 1

[0208] - CRC-24-Radix-64: x 24 + x 23 + x 18 + x 17 + x 14 + x 11 + x 10 + x 7 + x 6 + x 5 + x 4 + x 3 + x 1 + 1

[0209] - CRC-24-WCDMA : x 24 + x 23 + x 6 + x 5 + 1

[0210] As another example, if N is 21 bits, the value of the intermediate FCS (sub)field can be calculated based on CRC-21-CAN, etc.

[0211] As another example, if N is 17 bits, the value of the intermediate FCS (sub)field can be calculated based on CRC-17-CAN, etc.

[0212] As another example, if N is 16 bits, the intermediate FCS (sub)field value can be derived based on CRC-16-Chakravarty, CRC-16-CCITT, CRC-16-CDMA2000, CRC-16-DECT, CRC-16-T10-DIF, CRC-16-DNP, CRC-16-IBM, CRC-16-OpenSafety-A, CRC-16-OpenSafety-B, CRC-16-Profibus, or Fletcher-16 (e.g., Fletcher's checksum):

[0213] CRC-16-DECT : x 16 + x 10 + x 8 + x 7 + x 3 + 1;

[0214] CRC-16-T10-DIF : x 16 + x 15 + x 11 + x 9 + x 8 + x 7 + x 5 + x 4 + x 2 + x 1 + 1;

[0215] CRC-16-DNP : x 16 + x 13 + x 12 + x 11 + x 10 + x 8 + x 6 + x 5 + x 2 + 1

[0216] CRC-16-IBM: x 16 + x 15 + x 2 + x 1

[0217] As another example, if N is 15 bits, the intermediate FCS (sub)field value can be calculated based on CRC-15-CAN, etc.:

[0218] As another example, if N is 14 bits, the intermediate FCS (sub)field value can be derived based on CRC-14-GSM or CRC-14-DARC.

[0219] As another example, if N is 13 bits, the intermediate FCS (sub)field value can be calculated based on CRC-13-BBC, etc.:

[0220] CRC-13-BBC : x 13 + x 12 + x 11 + x 10 + x 7 + x 6 + x 5 + x 4 + x 2 + 1.

[0221] As another example, if N is 12 bits, the intermediate FCS (sub)field value can be derived based on CRC-12, CRC-12-CDMA2000, or CRC-12-GSM, etc.:

[0222] CRC-12: + x 12 + x 11 + x3+ x 2 + x 1 + 1.

[0223] As another example, if N is 11 bits, the intermediate FCS (sub)field value can be calculated based on CRC-11:

[0224] CRC-11 : x 11 + x 9 + x 8 + x 2 + 1.

[0225] As another example, if N is 10 bits, the intermediate FCS (sub)field value can be derived based on CRC-10, CRC-CDMA2000, or CRC-10-GSM:

[0226] CRC-10 : x 10 + x 9 + x 5 + x 4 + X 1 + 1.

[0227] As another example, if N is 8 bits, the intermediate FCS (sub)field value can be calculated based on CRC-8, CRC-8-AUTOSAR, CRC-8-CCITT, CRC-8-Dallas / Maxim, CRC-8-DARC, CRC-8-GSM-B, CRC-8-SAEJ1850, or CRC-8-WCDMA:

[0228] CRC-8 : x 8 + x 7 + x 6 + x 4 + x 2 + 1;

[0229] CRC-8-AUTOSAR : x 8 + x 5 + x 3 + x 2 + x 1 + 1;

[0230] CRC-8-Bluetooth: x 8 + x 7 + x 5 + x 2 + x 1 + 1;

[0231] CRC-8-CCITT: x 8 + x 2 + x 1 + 1;

[0232] CRC-8-Dallas / Maxim: x 8 + x 5 + x 4 + 1;

[0233] CRC-8-DARC: x8 + x 5 + x 4 + x 3 + 1;

[0234] CRC-8-GSM-B: x 8 + x 6 + x 3 + 1;

[0235] CRC-8-SAEJ1850: x 8 + x 4 + x 3 + x 2 + 1;

[0236] CRC-8-WCDMA: x 8 + x 7 + x 4 + x 3 + x 1 + 1.

[0237] As another example, if N is 7 bits, the intermediate FCS (sub)field value can be calculated based on CRC-7 or CRC-7-MVB:

[0238] CRC-7 : x 7 + x 3 + 1.

[0239] As another example, if N is 6 bits, the intermediate FCS (sub)field value can be derived based on CRC-6-CDMA2000-A, CRC-6-CDMA2000-B, CRC-6-GSM, or CRC-6-ITU:

[0240] CRC-6-GSM : x 6 + x 5 + x 3 + x 2 + x 1 + 1;

[0241] CRC-6-ITU: x 6 + x 1 + 1.

[0242] As another example, if N is 5 bits, the intermediate FCS (sub)field value can be derived based on CRC-5-EPC, CRC-5-ITU, or CRC-5-USB:

[0243] CRC-5-EPC : x 5 + x 3 + 1;

[0244] CRC-5-ITU : x 5 + x 4 + x 2 + 1;

[0245] CRC-5-USB : x 5 + x 2 + 1.

[0246] As another example, if N is 4 bits, the intermediate FCS (sub)field value can be calculated based on CRC-4-ITU:

[0247] CRC-4-ITU : x 4 + x 1 + 1;

[0248] As another example, if N is 3 bits, the intermediate FCS (sub)field value can be derived based on CRC-3-GSM:

[0249] CRC-3-GSM : x 3 + x 1 + 1;

[0250] As another example, if N is 1 bit, the intermediate FCS (sub)field value can be calculated based on CRC-1:

[0251] CRC-3-GSM : x 1 + 1.

[0252] Example 4

[0253] Example 4 relates to the configuration of a trigger frame including an intermediate FCS (sub)field.

[0254] As an example of the present disclosure, an intermediate FCS (sub)field may be included / added to the trigger frame illustrated in FIG. 8, and the location of the intermediate FCS (sub)field may be determined according to at least one of the detailed embodiments described below. In the following, it is assumed that a variant of a trigger frame that may include an intermediate FCS (sub)field is a basic trigger frame, an MU-RTS trigger frame, or a BSRP trigger frame, but is not limited thereto.

[0255] For example, if a special user information field and / or an FCS (sub)field are included on the basic trigger frame, the trigger dependent user information field within the special user information field may be set to a reserved value.

[0256] Example 4-1

[0257] Example 4-1 relates to the configuration of a trigger frame format with an intermediate FCS (sub)field added.

[0258] As an example of the present disclosure, as illustrated in (a), (b), and (c) of FIG. 14, an intermediate FCS (sub)field for an intermediate FCS may be located between a user information list field and a padding field of a trigger frame. The trigger frame may include an individually addressed trigger frame for an STA (e.g., a UHR STA) or a broadcast addressed trigger frame (only for UHR STA(s)).

[0259] As illustrated in (a) of FIG. 14, an intermediate FCS (sub)field may be included after the user information list field of the trigger frame, and an STA (e.g., a UHR STA) that can recognize the total length of the user information list field may receive a trigger frame including the intermediate FCS (sub)field. The STA may perform an FCS verification operation based on the value of the intermediate FCS (sub)field (e.g., 4 octets) of a predefined length after the last user information subfield.

[0260] For example, if the trigger frame is an individually addressed (single user (SU)) trigger frame for a UHR STA, there may be one user information field for the receiving UHR STA in the user information list field. The receiving STA can recognize the length of the user information list field and perform an FCS check operation using the value of the intermediate FCS (sub)field after the user information list field.

[0261] Additionally or alternatively, a last user information subfield may be defined via a reserved bit (e.g., the 26th bit (B25) etc.) in the EHT variant user information field of the corresponding trigger frame. That is, the last user information field in the corresponding trigger frame may be indicated via the value of the last user information subfield. A receiving STA may recognize that it is the last user information field via the above-described field, and may perform an FCS check operation via the value of the intermediate FCS (sub)field after the user information list field.

[0262] Additionally or alternatively, if the variant of the trigger frame is an MU-RTS trigger frame, a last user information subfield may be defined by one of the reserved bits (e.g., the 26th bit (B25) etc.) in the EHT variant user information field. That is, the value of the last user information subfield may indicate that it is the last user information field in the user information list field of the MU-RTS trigger frame. A receiving STA may recognize that it is the last user information field and perform an FCS verification operation by using the value of the intermediate FCS field located after the user information list field.

[0263] As an example of the present disclosure, it may be indicated that an intermediate FCS is included in a trigger frame, as illustrated in (b) of FIG. 14. Specifically, the value of the first 12 bits of the intermediate FCS (sub)field may be regarded as the AID12 subfield value. A portion of the first 12 bits of the intermediate FCS (sub)field may be set as a portion of the intermediate FCS value, and the remainder of the intermediate FCS value may be set on bits after the first 12 bits.

[0264] As an example, (b) of FIG. 14 illustrates a case where the intermediate FCS (sub)field (e.g., 40 bits) is considered as a type of special user information field, but is not limited thereto. For example, as illustrated in (b) of FIG. 14, if the total length of the intermediate FCS (sub)field is 40 bits and the length of the intermediate FCS value is 32 bits, there may be 8 reserved bits. Accordingly, in (b) of FIG. 14, n may have a value greater than or equal to 0 and less than or equal to 8.

[0265] For example, if n is 8 bits, all 8-bit values ​​can be set to 1. Through this, the value of the AID12 subfield having the value of the intermediate FCS can be defined as a range encompassing multiple values ​​rather than a specific value. For example, as illustrated in (b) of FIG. 14, the value of the AID12 subfield indicating that the intermediate FCS is included (on the trigger frame) can be defined based on the n bit (set to 1) rather than a specific value, and n can be 8, but is not limited thereto. Accordingly, as the value of n increases, the range of values ​​of the AID12 subfield indicating that the value of the intermediate FCS is included (on the trigger frame) can become smaller.

[0266] Additionally, as illustrated in (b) of FIG. 14, when the size of the intermediate FCS (sub)field is 40 bits and the length of the intermediate FCS value is 32 bits, there may be 8 reserved bits, in which case n may be 4. For example, the size of the intermediate FCS-1 (e.g., the field / bits in which part of the intermediate FCS value is set) may be 8 bits, and the size of the intermediate FCS-2 (e.g., the field / bits in which the remainder of the intermediate FCS value is set) may be 24 bits. In addition, the 4 bits after the intermediate FCS-2 may be reserved bits. Although the reserved bits are illustrated as being located after the intermediate FCS-2 in FIG. 14 (b), this is not limiting. The reserved bits may be located before the intermediate FCS-2.

[0267] As another example, as illustrated in (b) of FIG. 14, when the size of the intermediate FCS (sub)field is 40 bits and the length of the intermediate FCS value is 32 bits, there may be 8 reserved bits, where n may be 2. For example, the size of the intermediate FCS-1 may be 10 bits and the size of the intermediate FCS-2 may be 22 bits. In addition, the 6 bits after the intermediate FCS-2 may be reserved bits. Although (b) of FIG. 14 illustrates that the reserved bits are located after the intermediate FCS-2, this is not limiting. The reserved bits may be located before the intermediate FCS-2.

[0268] Additionally or alternatively, if all n bit values ​​in the AID12 subfield (e.g., a combination of intermediate FCS-1 and n bits) illustrated in (b) of FIG. 14 are set to 1, the value of the corresponding AID12 subfield may be set to 4095. Since the value (4095) indicates the start of a padding field, it may not be used as an AID12 value for the intermediate FCS. To prevent the AID12 subfield value from being set to 4095, at least one bit value among the n bits may be set to 0. As an example, assume that n is 8, 4, or 2 bits. In this case, the first bit value adjacent to the intermediate FCS-1 among the n bits may be set to 0.

[0269] As an example of the present disclosure, according to the configuration of the trigger frame illustrated in (c) of FIG. 14, a specific AID12 value related to the intermediate FCS (sub)field may be set on the AID12 subfield included in the intermediate FCS (sub)field. For example, the AID12 subfield may be set on the first x bits of the intermediate FCS (sub)field, and the AID12 subfield may be set to a value indicating that the field including the AID12 subfield includes the value of the intermediate FCS. That is, the value set in the AID12 subfield may mean that the value following the AID12 subfield is the value of the intermediate FCS. An STA (e.g., a UHR STA) that can recognize the intermediate FCS field / value may perform an FCS check operation based on the value of the intermediate FCS included in the intermediate FCS subfield.

[0270] Additionally or alternatively, the length of the intermediate FCS field may be aligned / fitted to octet units by adding M bits after the 12 bits of the AID12 subfield, and the M bit value may be set to 1 or 0, but is not limited thereto. For example, the 4 bits after the AID12 subfield in the intermediate FCS field may be considered reserved bits or may contain additional information.

[0271] Additionally or alternatively, similar to embodiment 2, a field indicating the presence or absence of an intermediate FCS (sub)field on the trigger frame illustrated in (a), (b) and (c) of FIG. 14 (e.g., an intermediate FCS (sub)field presence (sub)field) may be included.

[0272] Example 4-2

[0273] Example 4-2 relates to the configuration of a trigger frame including an intermediate FCS field / value within a user information list field.

[0274] As an example of the present disclosure, as illustrated in FIG. 15, an intermediate FCS (sub)field may be included in a user information field of a user information list field. The length of the HE / EHT variant user information field may be 40 bits, excluding the trigger-dependent user information subfield. However, if the AID12 subfield, which is the first field in the HE / EHT variant user information field, is excluded, the size of the space in which actual information can be set may be 28 bits. Since the value of the intermediate FCS is 4 octets (32 bits), the value of the intermediate FCS may not be set entirely within one user information field. Therefore, a trigger frame including the value of the intermediate FCS may be used by utilizing one or more user information fields within the trigger frame.

[0275] As an example of the present disclosure, as illustrated in FIG. 15, a portion (e.g., 28 bits) of the values ​​of the intermediate FCS may be set on a first user information field among at least one user information field. And, the remainder of the values ​​of the intermediate FCS may be set on a second user information field among at least one user information field (e.g., a second user information field following the first user information field).

[0276] However, this is only one embodiment, and the intermediate FCS value may be set separately for each of the two user information fields. For example, a 16-bit intermediate FCS value may be set separately for each of the two user information fields. As another example, a 20-bit (or 24-bit) intermediate FCS value may be set separately for the first user field, and a 12-bit (or 8-bit) intermediate FCS value may be set separately for the second user field. As another example, a 23-bit intermediate FCS value may be set separately for three user information fields. For example, intermediate FCS values ​​of 10, 10, and 12 bits may be set separately for each of the three user information fields.

[0277] As described above, when the value of the intermediate FCS is divided and set within multiple user information fields, the values ​​of the partial intermediate FCS from after the AID12 subfield indicating that the value of the intermediate FCS is included to before the AID12 subfield indicating that it is a padding field can be concatenated to obtain the value of the final intermediate FCS, and the STA can perform an FCS check operation based on the value of the final intermediate FCS.

[0278] Additionally or alternatively, if the value of the intermediate FCS is set on some of the 28 bits of the user information field, the remaining bits within that user information field that do not contain the value of the intermediate FCS may be set as reserved bits or may indicate additional information.

[0279] For example, when obtaining the value of the final intermediate FCS for FCS check, the STA may perform the FCS check operation by concatenating only the values ​​of the partial intermediate FCS, excluding the values ​​of the subfields indicating the reserved bits and / or additional information.

[0280] Additionally or alternatively, similar to embodiment 2, a field indicating the presence or absence of an intermediate FCS (sub)field on the trigger frame illustrated in FIG. 15 (e.g., an intermediate FCS (sub)field presence (sub)field) may be included.

[0281] Example 4-3

[0282] Example 4-3 relates to a method of setting an AID12 subfield indicating that a value of an intermediate FCS is included.

[0283] A specific value may be set on the AID12 subfield of the user information field including the intermediate FCS in the trigger frame configured based on Embodiment 4-1 and / or Embodiment 4-2. The specific value set in the AID12 subfield may be set based on the option(s) described below. For example, the specific value may not be assigned as the AID value of the associated STA, but is not limited thereto.

[0284] Option 1: A method in which a specific value(s) or a specific range of values ​​from 1 to 2007, which are set as the AID of the associated STA(s), are set in the AID12 subfield; and

[0285] Option 2: A specific value(s) or a specific range of values ​​from the reserved values ​​(2008 to 2044 or 2047 to 4094) is set in the AID12 subfield.

[0286] Example 4-4

[0287] Embodiment 4-4 relates to a method for indicating this when supporting both Embodiments 4-1 and 4-2. When the configuration of the intermediate FCS within the trigger frame is based on Embodiments 4-1 and / or 4-2, at least one of the methods described below may be applied.

[0288] Method 1

[0289] As an example of the present disclosure, either the configuration of a trigger frame based on Embodiment 4-1 or the configuration of a trigger frame based on Embodiment 4-2 may be indicated through a method of indicating whether an intermediate FCS (sub)field is included in a trigger frame of Embodiment 2. As an example, either the configuration of a trigger frame based on Embodiment 4-1 or the configuration of a trigger frame based on Embodiment 4-2 may be indicated through an intermediate FCS presence subfield included in the trigger frame (or a specific subfield in the trigger frame). Accordingly, it may be indicated through the value of the AID12 subfield that a user information field including the corresponding AID12 subfield is a user information field including a value of an intermediate FCS.

[0290] Additionally or alternatively, a method of indicating whether an intermediate FCS (sub)field is included in the trigger frame of Embodiment 2 may indicate that an intermediate FCS field / value of a specific length within the trigger frame is positioned before a padding field. For example, an intermediate FCS presence subfield included in the trigger frame (or a specific subfield within the trigger frame) may indicate that an intermediate FCS field / value is positioned before a padding field. Furthermore, a value of an AID12 subfield within a subsequent user information field may indicate that an intermediate FCS of a configuration according to Embodiment 4-1 or Embodiment 4-2 is included in the trigger frame.

[0291] For example, a value (e.g., an AID12 subfield value) for indicating that a user information field including an intermediate FCS value / field having a configuration according to Embodiment 4-1 exists may be determined based on Option 1 or 2 of Embodiment 4-3. A value of an AID12 subfield indicating that a user information field including an intermediate FCS value / field having a configuration according to Embodiment 4-2 exists may be determined based on Option 1 or 2 of Embodiment 4-3. As another example, a value of an AID12 subfield indicating that a user information field including an intermediate FCS value / field having a configuration according to Embodiment 4-2 exists may be a specific value of AID12 not used in Embodiment 4-2. As another example, the AID12 subfield values ​​corresponding to each of Embodiment 4-1 and Embodiment 4-2 may be changed.

[0292] Method 2

[0293] As an example of the present disclosure, a new subfield may be defined via a reserved subfield within a trigger frame, and the new subfield may include a value (e.g., 0, 1, 2, 3, etc.) indicating whether the configuration of the subsequent intermediate FCS value / field is based on Embodiment 4-1 or Embodiment 4-2.

[0294] For example, the new subfield may be set / defined on an EHT subfield of the common information field of the trigger frame (e.g., the 57th bit (B56) to the 63rd bit (B62)) or a reserved field of the special user information field of the trigger frame (e.g., the 38th bit (B37) to the 40th bit (B39)). Here, the new subfield may be defined as an intermediate FCS mode subfield, but is not limited thereto.

[0295] For example, assume that the middle FCS mode subfield has a length of 1 bit. If the middle FCS mode subfield value is set to 0 (or 1), this may indicate that the middle FCS field / value is configured based on Embodiment 4-1. If the middle FCS mode subfield value is set to 1 (or 0), this may indicate that the middle FCS field / value is configured based on Embodiment 4-2. For example, if the middle FCS presence subfield indicates that the middle FCS field does not exist or does not follow, the middle FCS mode subfield may be reserved.

[0296] As another example, assume that the intermediate FCS mode subfield has a length of 2 bits. In this case, if the intermediate FCS mode subfield value is set to 0, this may mean that the intermediate FCS value / field does not exist. If the intermediate FCS mode subfield value is set to 1 (or 2), this may indicate that the intermediate FCS field / value is configured based on embodiment 4-1 (or embodiment 4-2). The remaining values ​​of the intermediate FCS mode subfield (e.g., 3) may be reserved.

[0297] Example 5

[0298] Example 5 relates to a method for determining the length of padding within a trigger frame.

[0299] As described above, the length of the padding field in the trigger frame may be determined by the transmitting STA based on the larger of the time to prepare the UL MU data configuration in response to the trigger frame (hereinafter referred to as “MinTrigProcTime” of the trigger frame) or the padding delay time for Enhanced Multi-link Single Radio (EMLSR) / Enhanced Multi-link Multi-Radio (EMLMR) (if present).

[0300] The "MinTrigProcTime" for a trigger frame can be identified based on the value of the Trigger Frame MAC Padding Duration subfield in the HE MAC Capability Information field. The padding delay time for EMLSR / EMLMR can be identified based on the value of the EMLSR / EMLMR Padding Delay subfield in the EML Capability subfield of the Common Information field of the underlying multi-link element.

[0301] In the present disclosure, when the length of the padding field of a trigger frame including an intermediate FCS (sub)field is determined, the padding delay time for DPS can also be determined (by comparing it with the length of the corresponding padding field).

[0302] For example, an STA (e.g., a UHR STA) that supports DPS, integrity check for trigger frames, and / or DSO (etc.) may transmit and receive a join request frame and / or a separate new action frame to enable DPS. In this case, the join request frame and / or the new action frame may include a DPS padding delay value for a padding time of a padding field in a trigger frame desired by the STA. The DPS padding delay value may be set based on, but not limited to, the values ​​disclosed in Table 1 or Table 2.

[0303] DPS Padding Delay Subfield Values ​​DPS Padding Delay 00 μs 132 μs 264 μs 3128 μs 4256 μs 5-7 Reserved

[0304] DPS Padding Delay Subfield Values ​​DPS Padding Delay 00 μs 164 μs 2128 μs 3256 μs 41024 μs 5-7 Reserved

[0305] Additionally or alternatively, the DPS padding delay value announced from the STA to the AP may be based on N bits of a new (sub)field having the DPS padding delay value. For example, the DPS padding delay value may be a value calculated (e.g., "bit value x specific value") based on a specific value (e.g., unit, resolution) through the N bit value of the new (sub)field. Here, the specific value for obtaining (e.g., calculating) the DPS padding delay value may be one of 8, 16, 32, or 64. For example, if the new (sub)field has a length of 3 bits, the new sub(field) may have a value of one of 0 (e.g., "000") to 7 (e.g., "111"). The DPS padding delay value may be derived through the calculation of the value of the new sub(field) and the specific value.

[0306] As an example of the present disclosure, assume that a specific value is 64. In this case, if the new sub-field value is 0 (e.g., "000"), the DPS padding delay value may be 0 us. If the new sub-field value is 1 (e.g., "001"), the DPS padding delay value may be 64 us. If the new sub-field value is 2 (e.g., "010"), the DPS padding delay value may be 128 us. If the new sub-field value is 3 (e.g., "011"), the DPS padding delay value may be 192 us. If the new sub-field value is 4 (e.g., "100"), the DPS padding delay value may be 256 us. If the new sub-field value is 5 (e.g., "101"), the DPS padding delay value may be 320 us. If the new sub-field value is 6 (e.g., "110"), the DPS padding delay value may be 384 us. If the new sub-field value is 7 (e.g., "111"), the DPS padding delay value may be 448 us.

[0307] Additionally or alternatively, the DPS padding delay value announced from the STA to the AP may be based on N bits of a new (sub)field having the DPS padding delay value. For example, the DPS padding delay value may be obtained / calculated through an operation based on the N bit value of the new (sub)field and a specific value. In this case, the STA may also announce a specific value for calculating the DPS padding delay value to the AP. That is, a new (sub)field for the DPS padding delay and a new (sub)field including a specific value for calculating the DPS padding delay value may be defined. For example, 8, 16, 32, or 64 may be indicated through a new (sub)field value for a specific value (e.g., 0, 1, 2).

[0308] Additionally or alternatively, the DPS padding delay value announced from the STA to the AP may be based on a new (sub)field having the DPS padding delay value. For example, the DPS padding delay value may be obtained / calculated through an operation based on the N-bit value of the new (sub)field and a specific value. For example, when the new (sub)field has a length of 3 bits as shown in Table 1, the DPS padding delay value may be derived if the bit value in the specific calculation formula has a value greater than or equal to 1 (e.g., "001").

[0309] Here, if the value of the above bit is 0, the DPS padding delay value can be considered as 0 us. As an example, a specific calculation formula is 2 (n+4) Assume that if the N bit value of the new (sub)field is 1 (e.g., "001"), the DPS padding delay value is 32 (2 5 ) can be us. If the N bit value of the new (sub)field is 2 (e.g., "010"), the DPS padding delay value is 64 (2 6 ) can be us. If the N bit value of the new (sub)field is 2 (e.g., "010"), the DPS padding delay value is 64 (2 6) can be us. If the N bit value of the new (sub)field is 3 (e.g., "011"), the DPS padding delay value is 128 (2 7 ) can be us. If the N bit value of the new (sub)field is 4 (e.g., "100"), the DPS padding delay value is 256 (2 8 ) can be us. If the N bit value of the new (sub)field is 5 (e.g., "101"), the DPS padding delay value is 512 (2 9 ) can be us. If the N bit value of the new (sub)field is 6 (e.g., "110"), the DPS padding delay value is 1024 (2 10 ) can be us. If the N bit value of the new (sub)field is 7 (e.g., "111"), the DPS padding delay value is 2048 (2 11 ) may be us.

[0310] Additionally or alternatively, the DPS padding delay value announced from the STA to the AP may be based on a new (sub)field having the DPS padding delay value. Based on the value of each bit of the new (sub)field (e.g., m = 1 or 0), (m X 2 0 ) + (m X 2 1 ) + (m X 2 2 ) + (m X 2 3 ) + ... (m X 2 (N-1) ) operation can be performed to derive the value of the DPS padding delay subfield. The derived value can be the DPS padding delay subfield value transmitted from the non-AP STA to the AP, and each value can have a unit of us. The AP can set the DPS_PADDING_DELAY value to calculate the padding length in the trigger frame after identifying whether the corresponding DPS padding delay subfield value is within a specific range.

[0311] Here, the method for determining whether the value of the DPS padding delay subfield falls within a specific range may be performed according to the method described below, but is not limited thereto.

[0312] As an example, the AP can map the value of the derived DPS padding delay subfield to Table 3 and set the applicable value to "DPS_PADDING_DELAY".

[0313] DPS padding delay subfield value (us) DPS_PADDING_DELAY 00 1 ~ 32133 ~ 64265 ~ 1283 129 ~ 2564 Reserved 5-7

[0314] For example, when the value of the DPS padding delay subfield has a value from 1 to 32, the value of DPS_PADDING_DELAY may be set to 1. When the value of the DPS padding delay subfield has a value from 33 to 64, the value of DPS_PADDING_DELAY may be set to 2. When the value of the DPS padding delay subfield has a value from 65 to 128, the value of DPS_PADDING_DELAY may be set to 3. When the value of the DPS padding delay subfield has a value from 129 to 256, the value of DPS_PADDING_DELAY may be set to 4. Additionally or alternatively, the AP may compute a specific value (e.g., a product operation of 2) on the derived DPS padding delay subfield value to produce a final DPS padding delay subfield value. The AP can set the DPS_PADDING_DELAY value to an applicable value by mapping the produced value to Table 4. For example, if the size of the new (sub)field is 8 bits, the DPS padding delay subfield value can be defined as in Table 4, but is not limited thereto.

[0315] DPS padding delay subfield value (us) DPS_PADDING_DELAY 00 1 ~ 64165 ~ 1282129 ~ 2563257 ~ 5124 Reserved 5-7

[0316] For example, when the DPS padding delay subfield value has a value of 1 to 64, the value of DPS_PADDING_DELAY may be set to 1. When the DPS padding delay subfield value has a value of 65 to 128, the value of DPS_PADDING_DELAY may be set to 2. When the DPS padding delay subfield value has a value of 129 to 256, the value of DPS_PADDING_DELAY may be set to 3. When the DPS padding delay subfield value has a value of 257 to 512, the value of DPS_PADDING_DELAY may be set to 4. Embodiment 5-1

[0317] In one embodiment of the present disclosure, when a receiving STA (e.g., a UHR STA) supports EMLSR / EMLMR and / or DPS, a transmitting STA may calculate a padding time required for the STA (e.g., the receiving STA) based on a larger value among "MinTrigProcTime" of a trigger frame, padding (or transition) delay of EMLSR / EMLMR and / or DPS padding delay. Then, the transmitting STA may determine a length of a padding field that is greater than or equal to the calculated result value (e.g., padding time). The receiving STA may calculate the length of the padding field and padding times from the total MPDU length of the trigger frame based on the value of an MPDU delimiter.

[0318] As an example of the present disclosure, it is assumed that the padding delay value of EMLSR / EMLMR is the largest among the "MinTrigProcTime" of the trigger frame, the padding delay of EMLSR / EMLMR, and / or the DPS padding delay value. For example, an STA (e.g., a receiving STA or a transmitting STA) can derive a padding field value based on the padding delay value of EMLSR / EMLMR. Additionally or alternatively, if the receiving STA supports EMLSR / EMLMR, the STA can perform an operation for EMLSR / EMLMR during the padding time of the padding field. For example, the operation for EMLSR / EMLMR can be operated on two links, and then a link switching operation for gathering resources to one link can be performed. Additionally or alternatively, when transmitting UL MU data, the receiving STA can prepare to transmit UL MU data to the transmitting STA during the padding time of the padding field.

[0319] As an example of the present disclosure, it is assumed that the DPS padding delay value is the largest among the "MinTrigProcTime" of the trigger frame, the padding delay of EMLSR / EMLMR, and / or the DPS padding delay value. An STA (e.g., a receiving STA or a transmitting STA) can derive a padding field value within the trigger frame based on the values ​​of modulation-dependent parameter(s) and the padding delay value of the DPS. As an example, when the padding delay value of the DPS is defined by the values ​​exemplified in Table 1 or Table 2 or by the method according to the present disclosure, and the padding field value within the trigger frame is derived, "L PAD,MAC = N DBPS m PAD " The diet can be used.

[0320] For example, in the above equation, N DBPScan be set to a value calculated based on the value defined as a modulation-dependent parameter. If the padding delay value of DPS based on Table 1, Table 2, Table 3 or Table 4 is 0, m PAD can be set to 0.

[0321] For example, if the padding delay value of DPS based on Table 1 or Table 3 is greater than 0, m PAD can be set based on "2" DPS padding delay + 2". For example, when Table 1 is applied, the padding delay value of DPS can be utilized as one of the values ​​of the DPS padding delay subfield listed in the left column of Table 1. When Table 2 is applied, the padding delay value of DPS can be utilized as one of the values ​​of the DPS_PADDING_DELAY listed in the right column of Table 3.

[0322] As another example, if the padding delay value of DPS based on Table 2 or Table 4 is greater than 0, m PAD can be set based on "2" DPS padding delay + 3". For example, when Table 2 is applied, the padding delay value of DPS can be utilized as one of the values ​​of the DPS padding delay subfield listed in the left column of Table 2. When Table 4 is applied, the padding delay value of DPS can be utilized as one of the values ​​of the DPS_PADDING_DELAY listed in the right column of Table 4.

[0323] Additionally or alternatively, the DPS padding delay value may be calculated based on a new (sub)field of N bits having a DPS padding delay value. When the DPS padding delay value is calculated by an operation (e.g., "bit value * specific value") on the value of the N bits of the new (sub)field and a specific value (e.g., unit, resolution, etc.), m PADcan be predefined as to what value it will be set to. The transmitting STA can set the length of the padding field based on the values ​​described above. For example, if a specific value is 64 and the new (sub)field value for DPS padding delay is 4 (e.g., "100"), the resulting value can be 256us. In this case, m PAD can be defined to be set to 64.

[0324] As an example of the present disclosure, if a receiving STA supports EMLSR / EMLMR and DPS, the STA may perform operations for EMLSR / EMLMR and operations for DPS during the padding time of the padding field.

[0325] As another example, if a receiving STA only supports DPS, the STA may perform an operation for DPS during the padding time of the padding field. For example, the operation for DPS may include an operation for switching from a low capability bandwidth (e.g., 20 MHz) to a high capability bandwidth (e.g., 80 MHz) and an operation for checking CCA based on SIFS on the corresponding TXOP bandwidth based on the switching operation. Additionally, if UL MU data needs to be transmitted, the receiving STA may prepare UL MU data for the transmitting STA that transmitted the trigger frame.

[0326] Example 6

[0327] Example 6 relates to operations performed by each of a transmitting STA and a receiving STA. Example 6-1 relates to operations of a transmitting STA (e.g., an AP, etc.) that transmits a trigger frame, and Example 6-2 relates to operations of a receiving STA (e.g., a non-AP STA) that receives a trigger frame.

[0328] Example 6-1

[0329] The transmitting STA may determine whether the receiving STA supports / performs operations related to DPS, integrity check for trigger frames, and / or DSO during the padding time. If the receiving STA supports DPS, integrity check for trigger frames, and / or DSO, the transmitting STA may include the value of the intermediate FCS in the trigger frame.

[0330] For example, if the trigger frame includes an intermediate FCS field in which the value of the intermediate FCS is set, the transmitting STA may configure a trigger frame based on Embodiment 4-1 and transmit the configured trigger frame to the receiving STA. As another example, if the trigger frame includes an intermediate FCS field in which the value of the intermediate FCS is set, the transmitting STA may configure a trigger frame based on Embodiment 4-2 (e.g., a configuration in which an intermediate FCS subfield is included in one or more user information fields) and transmit the configured trigger frame to the receiving STA.

[0331] Example 6-2

[0332] As an example of the present disclosure, a legacy STA (e.g., an STA that does not support operations related to DPS, integrity check for trigger frames, and / or DSO, etc.) can decode a trigger frame transmitted by a transmitting STA. At this time, the legacy STA can recognize that the user information field of the trigger frame (e.g., a trigger frame based on embodiments 4-1 / 4-2) does not contain information applicable to it and can ignore it.

[0333] As another example, an STA (e.g., a UHR STA) that supports operations related to DPS, integrity check for trigger frames, and / or DSO, etc., may decode a specific AID12 subfield value indicating that a user information field of a trigger frame (e.g., a trigger frame based on embodiments 4-1 / 4-2) contains a value of an intermediate FCS. Additionally or alternatively, the STA may identify the presence or absence of a value of an intermediate FCS within the trigger frame through an intermediate FCS presence subfield of the trigger frame.

[0334] For example, when a trigger frame based on Example 4-2 is transmitted from a transmitting STA to a receiving STA, the receiving STA (e.g., a UHR STA) may concatenate intermediate FCS values ​​from the first user information field including the value of the intermediate FCS until the start of the padding field (e.g., the intermediate FCS value positioned after the AID12 subfield in the second user information field).

[0335] Thereafter, when the value of the AID12 subfield indicating the start of the padding field is set, the receiving STA (e.g., UHR STA) may perform an FCS check operation on the received trigger frame based on the intermediate FCS value obtained so far. This operation may be commonly performed when the trigger frame is configured based on Embodiments 4-1 and 4-2.

[0336] For example, if the result of the FCS check based on the intermediate FCS value of the UHR STA is successful, the UHR STA may perform actions supported by the UHR STA during the padding time, such as DPS, integrity check for trigger frames, and / or DSO.

[0337] Additionally or alternatively, if UL MU data needs to be transmitted, the receiving STA may prepare the UL MU data to be transmitted to the transmitting STA during the padding time. After the padding time of the padding field, the receiving STA may not perform additional FCS check operations during the time corresponding to the FCS field (e.g., the FCS field positioned following the padding field). After the FCS field, the receiving STA may transmit a response message (e.g., ICR, UL MU data, etc.) for the trigger frame to the transmitting STA.

[0338] For example, if the result of the FCS check based on the intermediate FCS value of the receiving STA (e.g., UHR STA) is a failure (e.g., FCS check failure and / or FCS value is incorrect), the receiving STA may perform an Extended Interframe Space (EIFS) related operation in the FCS field after the padding time of the padding field.

[0339] As an example of the present disclosure, when a value of an AID12 subfield indicating that a padding field begins is acquired, a receiving STA (e.g., a legacy STA) may use the padding time of the padding field as a preparation time for transmitting an operation supporting ELMSR / EMLMR and / or UL MU data. When the padding time expires / elapses, the receiving STA may perform an FCS check operation for the trigger frame based on a value in the FCS field (e.g., an FCS field following the padding field). The above operation may be commonly performed when the trigger frame is configured based on Embodiments 4-1 and 4-2.

[0340] For example, if the FCS check based on the corresponding FCS field is successful, the legacy STA may transmit UL MU data for the corresponding trigger frame to the transmitting STA. As another example, if the FCS check is unsuccessful, the receiving STA may perform EIFS-related actions.

[0341] At least one of the above-described embodiments of the present disclosure (e.g., Embodiment 1, Embodiment 2, Embodiment 3, Embodiment 4, Embodiment 4-1, Embodiment 4-2, Embodiment 4-3, Embodiment 4-4, Embodiment 5, Embodiment 5-1, Embodiment 6, Embodiment 6-1, Embodiment 6-2) may be applied, and combinations between the respective embodiments may also be applied.

[0342] The embodiments described above are combinations of components and features of the present disclosure in a predetermined form. Each component or feature should be considered optional unless explicitly stated otherwise. Each component or feature may be implemented without being combined with other components or features. Furthermore, it is also possible to form embodiments of the present disclosure by combining some components and / or features. 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 self-evident that claims that do not have an explicit citation relationship in the patent claims may be combined to form embodiments or incorporated as new claims through post-application amendments.

[0343] 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 thereof. Therefore, the above detailed description should not be construed as limiting in any respect, but rather as illustrative. The scope of the present disclosure should be determined by a reasonable interpretation of the appended claims, and all modifications within the scope of equivalents of the present disclosure are intended to be included within the scope of the present disclosure.

[0344] 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 methods of 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 comprise a non-transitory computer-readable storage medium. The features described in this disclosure may be incorporated into software and / or firmware stored on any of the machine-readable media, which may control the hardware of the processing system and 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.

[0345] 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

1. A step of receiving a trigger frame including an immediate frame check sequence (FCS) field from a second STA by a first station (STA); and A step of transmitting a response frame based on the trigger frame to the second STA by the first STA, The common information field of the trigger frame includes a first field related to whether the intermediate FCS field is included in the trigger frame, A method wherein the intermediate FCS field is included on at least one user information field of the trigger frame.

2. In paragraph 1, The above trigger frame includes a padding field and an FCS field, The above padding field is placed immediately after the middle FCS field within the trigger frame, A method wherein the FCS field is placed immediately after the padding field within the trigger frame.

3. In paragraph 1, Based on the above at least one user information field being a first user information field: The first user information field includes a first association identifier (AID)12 subfield and the intermediate FCS field, A method in which the first AID12 subfield is set to a value related to the intermediate FCS field.

4. In paragraph 3, A method wherein the intermediate FCS field is positioned immediately after the AID12 subfield within the first user information field.

5. In paragraph 1, The at least one user information field includes a second user information field and a third user information field, The first bit of the above intermediate FCS field is included in the first user information field, A method wherein the second bit of the above intermediate FCS field is included in the second user information field.

6. In paragraph 5, A first cyclic redundancy check (CRC) value set for the first bit and a second CRC value set for the second bit are concatenated by the first STA, A method in which an FCS check operation is performed by the first STA based on the first CRC value and the second CRC value.

7. In paragraph 5, A method wherein the length of the first bit is 24 bits and the length of the second bit is 8 bits.

8. In paragraph 1, The above intermediate FCS field comprises: i) a second AID12 subfield containing an intermediate FCS-1 subfield and ii) an intermediate FCS-2 subfield; The length of the above intermediate FCS-1 subfield is 12-n (n is a natural number less than or equal to 8) bits, A method wherein one of the n bits in the second AID12 subfield is set to 0.

9. In paragraph 8, The above FCS-2 subfield is placed immediately after the n bits within the second AID12 subfield, A method wherein the value of the second AID12 subfield is based on a specific range containing one or more values.

10. In paragraph 1, The length of the above intermediate FCS field is 32 bits.

11. In paragraph 1, A frame including a dynamic power save (DPS) padding delay field is transmitted from the first STA to the second STA, A method wherein, based on a value in the DPS padding delay field being greater than a time value for processing the trigger frame in the first STA, the time value for processing the trigger frame is replaced with a value in the DPS padding delay field.

12. In paragraph 1, A method wherein the trigger frame includes information regarding whether the intermediate FCS field is included in a single user information field or multiple user information fields.

13. In the first station (STA), the first STA: one or more transmitters and receivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Receiving a trigger frame including an immediate frame check sequence (FCS) field from a second STA through the one or more transceivers; and A response frame based on the trigger frame is set to be transmitted to the second STA through the one or more transceivers, The common information field of the trigger frame includes a first field related to whether the intermediate FCS field is included in the trigger frame, The above intermediate FCS field is included in at least one user information field of the trigger frame, the first STA.

14. A step of transmitting a trigger frame including an immediate frame check sequence (FCS) field by a second station (STA) to a first STA; and A step of receiving a response frame based on the trigger frame from the first STA by the second STA, The common information field of the trigger frame includes a first field related to whether the intermediate FCS field is included in the trigger frame, A method wherein the intermediate FCS field is included on at least one user information field of the trigger frame.

15. In the second station (STA), the second STA: one or more transmitters and receivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Transmitting a trigger frame including an immediate frame check sequence (FCS) field to the first STA through the one or more transceivers; and A response frame based on the trigger frame is set to be received from the first STA through the one or more transceivers, The common information field of the trigger frame includes a first field related to whether the intermediate FCS field is included in the trigger frame, The above intermediate FCS field is included in at least one user information field of the trigger frame, the second STA.

16. In a processing device, 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.

17. One or more non-transitory computer-readable media storing one or more instructions, A computer-readable medium, wherein the one or more commands are executed by one or more processors to control a device to perform a method according to any one of claims 1 to 12.

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