WO2025234774A1 - Method and apparatus for transmitting or receiving in-device coexistence-related information in wireless lan system - Google Patents

Abstract

Disclosed are a method and an apparatus for transmitting or receiving in-device coexistence-related information in a wireless LAN system. A method, according to one embodiment of the present disclosure, comprises the steps of: receiving, by a first station (STA), a trigger frame for soliciting IDC information from a second STA; and transmitting, by the first STA, a response frame to the second STA on the basis of the trigger frame, wherein the response frame may include at least one aggregated (A)-control field related to the IDC information, and the IDC information may include information on a time at which an operation related to the IDC is started and information on a duration of the operation related to the IDC.

Description

Method and device for transmitting or receiving information related to internal coexistence of a terminal in a wireless LAN system

The present disclosure relates to a method and device for transmitting or receiving information related to in-device coexistence (IDC) in a wireless local area network (WLAN) system.

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.

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.

The technical problem of the present disclosure is to provide a method and device for transmitting or receiving information related to in-device coexistence (IDC) in a wireless LAN system.

The technical problem of the present disclosure is to provide a method and device for signaling an aperiodic event of an IDC based on a trigger frame.

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 can be clearly understood by a person having ordinary skill in the technical field to which the present disclosure belongs from the description below.

A method according to one embodiment of the present disclosure comprises the steps of: receiving, by a first station (STA), a trigger frame for soliciting in-device coexistence (IDC) information from a second STA; and transmitting, by the first STA, a response frame to the second STA based on the trigger frame, wherein the response frame includes at least one aggregated (A)-control field related to the IDC information, and wherein the IDC information may include information about a time at which an operation related to the IDC starts and information about a duration of the operation related to the IDC.

A method according to one embodiment of the present disclosure comprises the steps of: transmitting a trigger frame for soliciting in-device coexistence (IDC) information by a second station (STA) to at least one STA including a first STA; and receiving a response frame by the second STA from the first STA based on the trigger frame, wherein the response frame includes at least one aggregated (A)-control field related to the IDC information, and wherein the IDC information may include information about a time at which an operation related to the IDC starts and information about a duration of the operation related to the IDC.

According to various embodiments of the present disclosure, a method and device for transmitting or receiving IDC-related information in a wireless LAN system can be provided.

According to various embodiments of the present disclosure, a method and apparatus for signaling an aperiodic event of an IDC based on a trigger frame may be provided.

By various embodiments of the present disclosure, performance degradation that may occur due to an IDC event can be prevented.

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.

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.

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

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

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

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

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

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

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

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

Figure 9 is a diagram illustrating a procedure for generating an IDC event between a Wi-Fi device and a non-Wi-Fi device.

FIG. 10 is a diagram illustrating an example of a method performed by a first STA according to the present disclosure.

FIG. 11 is a drawing for explaining an example of a method performed by a second STA according to the present disclosure.

FIG. 12 is a diagram illustrating an IDC event signaling procedure based on a trigger frame according to an embodiment of the present disclosure.

FIG. 13 and FIG. 14 are diagrams for explaining the configuration of IDC information according to one embodiment of the present disclosure.

FIG. 15 is a diagram for explaining an IDC event signaling procedure based on a trigger frame according to one embodiment of the present disclosure.

FIG. 16 and FIG. 17 are drawings for explaining the configuration of an A-control field according to one embodiment of the present disclosure.

FIG. 18 is a diagram for explaining an IDC event signaling procedure based on a trigger frame according to one embodiment of the present disclosure.

FIG. 19 is a diagram for explaining the configuration of an IDC information field according to one embodiment of the present disclosure.

FIG. 20 is a diagram for explaining an IDC event signaling procedure based on a trigger frame according to one embodiment of the present disclosure.

FIG. 21 is a diagram illustrating a method for transmitting IDC information via an unsolicited control frame and/or action frame according to one embodiment of the present disclosure.

FIG. 22 is a diagram for explaining an IDC event signaling procedure based on a trigger frame according to one embodiment of the present disclosure.

FIG. 23 is a diagram for explaining a PPDU transmission and reception procedure between a transmitting STA and a receiving STA according to one embodiment of the present disclosure.

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.

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.

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.

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.

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.

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.

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

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

The first device (100) and the second device (200) illustrated in FIG. 1 may be replaced with various terms such as a terminal, a wireless device, a 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.

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.

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.

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).

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.

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.

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.

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.

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.

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) may convert received user data, control information, wireless signals/channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals/channels, etc. using one or more processors (102, 202). One or more transceivers (106, 206) may convert processed user data, control information, wireless signals/channels, etc. from baseband signals to RF band signals using one or more processors (102, 202). For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and/or a filter.

For example, one of the STAs (100, 200) may perform the intended operation of an AP, and the other of the STAs (100, 200) may perform the intended operation of a non-AP STA. For example, the transceivers (106, 206) of FIG. 1 may perform transmission and reception operations of signals (e.g., packets or PPDUs (Physical layer Protocol Data Units) according to IEEE 802.11a/b/g/n/ac/ax/be/bn, etc.). In addition, in the present disclosure, operations 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.

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.

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

The structure of a wireless LAN system can be composed of multiple components. 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.

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.

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).

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.

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.

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).

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.

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.

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

An ESS is a network of arbitrary size and complexity, consisting of 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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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.

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

For example, the association request frame may include information about various capabilities, a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, 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.

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.

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.

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

In wireless LAN systems, the basic access mechanism of MAC (Medium Access Control) is 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.

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).

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

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.

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.

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.

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.

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

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.

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.

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.

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.

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.

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.

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.

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

The PHY layer can prepare an MPDU (MAC PDU) to be transmitted 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.

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

A basic PPDU may include a Short Training Field (STF), a Long Training Field (LTF), a SIGNAL (SIG) field, and a Data field. The most basic (e.g., non-HT (High Throughput) as illustrated in FIG. 7) PPDU format may consist of only 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.

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.

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.

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.

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.

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.

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).

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

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)).

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).

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)).

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.

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.

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.

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.

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.

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

The U-SIG included in the EHT PPDU format of FIG. 7 can be configured based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG can have a duration of 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.

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.

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.

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.

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

For example, the version-independent bits of 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.

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.).

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.

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.

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.

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.).

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.

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.

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.

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.

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.

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.

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, 4X996-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.

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.

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.

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

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.

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.

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.

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

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

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

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.

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.

Signaling procedures for IDC events and related information

Wi-Fi technology (e.g., wireless LAN system-based technology) can be used together with non-Wi-Fi technologies in similar frequency bands (e.g., 2.4 GHz, 5 to 6 GHz, etc.). Various devices (e.g., smartphones, smart watches, VR/AR devices, etc.) use/apply non-Wi-Fi technologies (e.g., Bluetooth (BT), Zigbee, UWB (Ultra-wideband), etc.) together with Wi-Fi technology, and the IDC that occurs when the above-mentioned technologies operate simultaneously has a significant impact on mutual wireless communication.

For example, when Wi-Fi and BT/UWB interfere with each other's signals, packet loss and rate degradation can occur, which can lead to performance degradation due to transmission throughput and delay. In other words, when data from a non-Wi-Fi technology is transmitted and received on a single device, it can affect Wi-Fi transmission and reception.

For example, referring to FIG. 9, an AP can obtain a TXOP by transmitting an MU-RTS frame to simultaneously transmit data to STA 1, STA 2, and STA 3. Since STA 1, STA 2, and STA 3 are capable of receiving data upon receiving the MU-RTS frame, they can transmit a CTS frame, which is a response frame to the MU-RTS frame, to the AP. The AP can then initiate data transmission to STA 1, STA 2, and STA 3.

At this time, data transmission/reception/exchange operations between STA 2 and a non-Wi-Fi device may be performed/occurring, and STA 2 may fail to receive data transmitted by the AP.

To solve the above-described problem, a procedure for signaling the IDC state of the AP (and/or TXOP holder) is required for smooth Wi-Fi communication between devices, and if the STA and/or AP avoid data transmission operations within the IDC section through signaling of the IDC state, performance degradation due to IDC occurrence can be prevented.

Specifically, as illustrated in FIG. 9, IDC events/situations may occur in smart devices (e.g., smartphones, smartwatches, VR/AR devices, etc.) that can use/apply Wi-Fi and non-Wi-Fi technologies together. Additionally, IDC events/situations may occur in devices that apply non-simultaneous transmit and receive (NSTR) in multi-link devices (MLDs). Devices that generate IDC events may signal information related to the IDC event via trigger frames.

FIG. 10 is a diagram illustrating an example of a method performed by a first STA according to the present disclosure. In describing the present disclosure, the first STA is a non-AP STA, and at least one STA, including the second STA, may be an AP, but is not limited thereto. Each of the first STA and the at least one STA may be either a non-AP STA or an AP.

The first STA can receive a trigger frame for soliciting IDC information from the second STA (S1010).

For example, a trigger frame may include information indicating a request for IDC information. In this case, the trigger frame may be, but is not limited to, a BSRP trigger frame.

Here, the IDC information may include at least one of information about the time when an operation related to the IDC starts, information about the duration of the operation related to the IDC, information about the channel or bandwidth on which the operation related to the IDC occurs, information about the number of spatial streams related to the operation related to the IDC, or information about an antenna available during the duration of the operation related to the IDC.

Here, information about the time at which an IDC-related operation starts may include information about a partial timing synchronization function (TSF) time at which the IDC-related operation is expected to start. Furthermore, the IDC-related operation interval may include a time interval length during which the IDC-related operation is expected to continue, and the time interval length may be set based on a specific unit time.

Furthermore, IDC-related operations may include operations in which the entire operating channel of the first STA or at least one subchannel of the entire operating channel becomes unavailable. In describing the present disclosure, IDC-related operations may be replaced with IDC events, unavailable operations, unavailable events, etc.

The first STA can transmit a response frame to the second STA based on the trigger frame (S1020).

As an example of the present disclosure, a response frame may include at least one aggregated (A)-control field related to IDC information. The response frame may include, but is not limited to, a CTS frame, a BA frame, a multi-STA BA frame, a control frame, an action frame, a QoS null frame, a QoS-related frame, etc. related to IDC. The number of A-control fields included in the response frame may be one or more.

For example, assume that a single A-control field is included in the response frame. The single A-control field may include i) a control ID value subfield and ii) at least one subfield containing IDC information. In this case, the control ID value subfield may be set to one of 10 to 14. The single A-control field may include at least one subfield in which each of the multiple types of IDC information described above is set/included.

As another example of the present disclosure, assume that a response frame includes multiple A-control fields. The multiple A-control fields may include a first A-control field containing information about the time at which an IDC-related operation begins, and a second A-control field containing information about the duration of the IDC-related operation.

Additionally or alternatively, the plurality of A-control fields may include at least one of a third A-control field containing information about a channel or bandwidth over which an IDC-related operation occurred, a fourth A-control field containing information about a number of spatial streams associated with the IDC-related operation, or a fifth A-control field containing information about an antenna available during an interval of an IDC-related operation.

The control ID value included in each of the plurality of A-control fields may be set to one of 10 to 14, and the control ID values associated with each A-control field may be different. For example, the control ID value of the first A-control field may be set to a first value from 10 to 14, and the control ID value of the second A-control field may be set to a second value different from the first value from 10 to 14.

Meanwhile, the first STA may transmit a response frame to the second STA within the second STA's transmission opportunity (TXOP). Communication between the first STA and the second STA may be performed within a period excluding the period of operation related to the IDC.

The method described in the example of FIG. 10 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 for soliciting IDC information from a second STA through one or more transceivers (106). The one or more processors (102) may transmit a response frame to the second STA through one or more transceivers (106) based on the trigger frame.

Furthermore, one or more memories (104) of the first device (100) 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 (102).

FIG. 11 is a drawing for explaining an example of a method performed by a second STA according to the present disclosure.

A second STA may transmit a trigger frame to at least one STA, including the first STA, to request IDC information (S1110). Here, it is assumed that the first STA has scheduled/detected the start of an IDC-related operation (e.g., a data exchange operation with a non-Wi-Fi device).

The second STA can receive a response frame from the first STA based on the trigger frame (S1120).

The second STA can identify information (e.g., start time, interval, etc.) about the IDC-related operation of the first STA through the response frame. The second STA can exchange data with the first STA during a time period excluding the interval of the IDC-related operation.

The method described in the example of FIG. 11 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. 11 may transmit a trigger frame for requesting IDC information to at least one STA, including the first STA, through one or more transceivers (206). The one or more processors (202) may receive a response frame from the first STA through one or more transceivers (206) based on the trigger frame.

Furthermore, one or more memories (204) of the second device (200) may store commands for performing the method described in the example of FIG. 11 or the examples described below when executed by one or more processors (202).

Below, the signaling procedures for IDC events and related information are specifically described. In describing this disclosure, IDC events may be replaced with unavailable events or unavailable actions.

Example 1

Example 1 relates to an IDC event signaling procedure and information transmitted and received through the procedure.

FIG. 12 is a diagram illustrating an IDC event signaling procedure based on an MU-RTS trigger frame according to an embodiment of the present disclosure.

As illustrated in FIG. 12, a Wi-Fi device (e.g., a non-AP STA and/or an AP) that may generate an IDC event/situation may transmit information related to the IDC via a basic trigger frame (e.g., a trigger frame described with reference to FIG. 8) or/and a new trigger frame.

For example, when an STA detects that a data exchange with another non-Wi-Fi device is initiated, the STA may transmit information related to the IDC to another STA (e.g., an AP) via a response frame of a trigger frame (e.g., an MU-RTS trigger frame, a BSRP trigger frame, etc.). For example, the information related to the IDC may include an IDC (SP (service period)) start time, an IDC occurrence interval (duration), an IDC interval (duration), an IDC bandwidth (or information about a channel, a resource unit, multiple resource units, distributed resource units, etc.), an IDC indication (or an IDC status), and/or available NSS (number of spatial streams), etc.

Accordingly, the AP may transmit DL MU PPDUs to at least one STA, except for STA 2. That is, the AP may anticipate that data transmission to STA 2 will fail, and thus may not transmit data to STA 2. In addition, the AP may transmit data to STA 2 after the unavailability time of STA 2 (e.g., IDC event period) ends.

Additionally or alternatively, if an available channel exists, the AP and STA 2 can transmit and receive data over that channel during the same time (e.g., during unavailable time).

In the above-described operations, the AP may change into a non-AP STA, and the non-AP STA may change into an AP. That is, in describing the present disclosure, the operations of the AP may be replaced/interpreted/changed with the operations of the non-AP STA, and the operations of the non-AP STA may be replaced/interpreted/changed with the operations of the AP.

Example 1-1

Example 1-1 relates to information related to IDC (e.g., IDC information (info)). As an example of the present disclosure, the information related to IDC may include at least one of an IDC start time (ST), an IDC duration, an IDC interval, an IDC continuity, an IDC channel/BW, and an IDC NSS/antenna.

IDC start time

As an example of the present disclosure, the IDC ST may include information about when the IDC occurs (e.g., when “unavailability” occurs). Additionally, “unavailability” may mean that the entire channel on which the STA operates or some subchannels of the channel (e.g., X subchannels of 20 MHz) are unavailable. That is, “unavailability” may mean that the entire channel on which the STA operates is unavailable or some portion of the channel is unavailable.

Additionally or alternatively, the IDC ST may be used as the entire (e.g., 8 octets) or part of the timestamp (TSF) received from the AP or the AP itself (e.g., partial TSF). For example, when partial TSF is applied, similar to the basic broadcast TWT, starting from a specific bit value of the TSF up to X octets (e.g., 2 octets) may be used.

Additionally or alternatively, the IDC ST may be indicated based on a duration (e.g., us) value from the start or end of transmission of a frame containing/transmitting the current IDC ST information.

Additionally or alternatively, the IDC ST may be indicated using the interval field of the MAC header. For example, the interval value of the interval field of the frame may mean/indicate the interval up to the IDC ST (based on the time of transmission or reception of the frame).

Additionally or alternatively, if the IDC ST is indicated via the interval field of the above frame, separate indication/information for the IDC ST may be omitted.

Additionally or alternatively, the IDC ST may indicate the start time of an available interval during which no "unavailable" occurs due to the IDC.

IDC section

An IDC interval can refer to the time period during which an IDC (or IDC event) persists. For example, an IDC interval can be designated based on a specific unit of time (e.g., us). Information associated with an IDC interval can include information about a specific unit of time (e.g., a unit of time used to designate the duration of the IDC).

For example, information related to an IDC interval may include a specific unit of time (e.g., 1 us, 8 us, 32 us, 64 us, etc.) and/or a time interval value for which the IDC lasts based on the specific unit of time. For example, if the time interval value is indicated as 1000 and the unit of time value is indicated as 1 us, this may mean that the IDC interval is 1 ms. As another example, if the time interval value is indicated as 1000 and the unit of time value is indicated as 8 us, this may mean that the IDC interval is 8 ms.

For example, the IDC interval field (e.g., a field in which information related to the IDC interval is set) may consist of 2 octets, like the interval field of the MAC header, but is not limited thereto, and may have a smaller size.

For example, if an IDC ST exists, the IDC interval may be omitted. In this case, the IDC interval may (implicitly) indicate a time interval from the IDC ST to the end time of a specific period (e.g., if a start time is indicated within a TXOP, the end time of the TXOP).

IDC interval

The IDC interval can refer to the interval between consecutive IDCs when the IDCs occur periodically. For example, the IDC interval can refer to the interval between the start times of consecutive IDCs.

For example, the IDC interval may be indicated based on a specific unit of time (e.g., microseconds). Information associated with the IDC interval may include information regarding the specific unit of time (e.g., a unit of time indicating the duration of the IDC).

For example, information related to the IDC interval may include a specific unit time (e.g., 1 us, 8 us, 32 us, 64 us, etc.) and/or an IDC interval value based on a specific unit time. For example, if 1000 is indicated as the interval value and 1 us is indicated as the unit time value, this may mean that the IDC interval is 1 ms. As another example, if 1000 is indicated as the interval value and 8 us is indicated as the unit time value, this may mean that the IDC interval is 8 ms.

For example, the IDC interval field (i.e., a field in which information related to the IDC interval is set) may consist of 2 octets, like the interval field of the MAC header, but is not limited thereto, and may have a smaller size.

Additionally or alternatively, if the IDC ST indicates the start time of an available segment, the IDC segment and/or interval may indicate the duration of the available segment.

IDC Continuity

IDC continuity may contain/indicate information about how long an IDC lasts. IDC continuity may indicate the number of each IDC (e.g., an integer).

Additionally or alternatively, the IDC continuity may indicate the total duration of the IDC ST or the point at which the continuous IDC ends. The total duration of the IDC ST and the point at which the continuous IDC ends may be indicated based on information related to the IDC interval and information related to the IDC ST.

Additionally or alternatively, the number of beacon frames, target beacon transmission time (TBTT), and/or beacon interval may be utilized.

For example, based on information about the number of beacon frames, TBTT, and/or beacon interval, it may be indicated how many times a beacon frame is transmitted within a period that lasts from the time the IDC first occurs. As another example, based on information about the number of beacon frames, TBTT, and/or beacon interval, it may be indicated how many beacon intervals an IDC lasts from the time the IDC first occurs.

For example, when information about IDC spacing exists as IDC-related information, information about IDC continuity may be present. If information about IDC spacing does not exist as IDC-related information, information about IDC continuity may be omitted.

IDC Channel/BW

The IDC channel/BW may refer to the channel/BW where IDC occurs. For example, the IDC channel/BW may be indicated via a bitmap. For example, each bit in the bitmap related to the STA's operating channel and BW may indicate whether a 20 MHz subchannel is available (e.g., whether IDC has occurred).

Additionally or alternatively, since the BW per STA (e.g., the BW of the STA's operating channel or/and the BW where IDC may occur) may be different, information about the IDC channel/BW may include the BW information of each STA or may be indicated separately. For example, if the BW is indicated as 20, 40, 80, 160, or 320 MHz, etc., as many bitmaps as the number of 20 MHz subchannels corresponding to each BW may be configured.

Additionally or alternatively, the IDC BW information may indicate a limited BW that the STA can transmit and receive due to the IDC. In this case, information about the IDC channel may not exist as information related to the IDC.

Additionally or alternatively, the IDC BW information may include information about available or unavailable bandwidth due to IDC conditions. In this case, the IDC BW information may include the center frequency and bandwidth of the BW and/or start and end information of the bandwidth.

Additionally or alternatively, IDC BW information may be indicated/set by a table value of the RU allocation subfield of the frame. When IDC BW information is indicated by the RU allocation subfield, the frequency band used by non-Wi-Fi wireless technologies in the IDC situation may be converted based on the RU allocation subfield according to Wi-Fi operation. As an example, the subfield indicating IDC BW information may be configured as shown in Table 1.

Bit: 0-1 Beats: 2-7 Octet: 1 or 2 Octet: 1 or 2 BW type Reserved Start frequency/center frequency/BW Termination frequency/frequency bandwidth/RU allocation

Here, field values related to the BW type can be defined as in Table 2. All or only some of the types disclosed in Table 2 can be defined, and the values corresponding to each type can be configured differently from Table 2.

value meaning 0 Frequency Range 1 center frequency 2 Resource Unit 3 Reserved

For example, if the field value related to the BW type is set to 0, the second subfield within the (IDC) BW subfield may indicate the start frequency, and the third subfield may indicate the end frequency. For example, the second subfield may be set to 2,400(*106) as the start frequency. 2.4GHz) can be indicated, and the third subfield is the end frequency, 2483(*106 2.48GHz). For example, if the field value related to the BW type is set to 1, the second subfield within the (IDC) BW subfield can indicate the center frequency, and the third subfield can indicate the frequency bandwidth. For example, the second subfield can be set to 7,987(*106) as the start frequency. The first subfield can indicate 7.9 GHz), and the third subfield can indicate 500 (*106 == 500 MHz) as the end frequency.

For example, if the field value related to the BW type is set to 2, the second subfield within the (IDC) BW subfield may indicate BW. If the field/bit value indicating the BW indicates 0, 1, 2, 3, or 4 respectively, this may mean 20 MHz, 40 MHz, 80+80 MHz, 160 MHz, 320 MHz-1, or 320 MHz-2, and the remaining values may be reserved. That is, the size of the field/bit indicating the BW may be 1 octet. The third subfield within the (IDC) BW subfield may indicate BW based on the RU allocation subfield value.

Additionally or alternatively, the (IDC) BW subfield described above may be omitted if the available or unavailable channel is indicated by the target wake time (TWT) channel subfield.

IDC NSS/Antenna

IDC NSS/Antenna information may refer to the NSS/antenna that is available or unavailable when an IDC occurs.

The IDC NSS value can indicate the number of available spatial streams. The IDC NSS value can indicate the number of spatial streams that are available or unavailable due to IDC, so that the STA can use the actual available spatial streams.

Additionally or alternatively, the field related to the IDC NSS/antenna may indicate the index of an antenna (or the number of antennas or a numerical value associated with the antenna) that is available or unavailable in the IDC situation. For example, the antenna with the lowest index may be indicated based on the MSB or LSB of the field related to the IDC NSS/antenna.

Example 1-2

In one embodiment of the present disclosure, the presence and/or configuration of information related to the IDC described with reference to Example 1-1 may be determined according to the IDC scenario.

For example, if an IDC affects the primary channel of the BSS to which the STA belongs, the STA may not be able to use all channels due to the IDC, and thus information related to the IDC channel/BW may not exist or may be reserved.

As another example, if an IDC affects the entire spatial stream or operating channel of an STA, the STA may not be able to use all channels and/or spatial streams due to the IDC, and information related to the IDC channel/BW or/and spatial stream may not exist or may be reserved.

As another example, if IDCs occur episodically rather than periodically, information about IDC intervals and/or IDC continuity may not exist or may be reserved.

Below, we describe the composition and examples of IDC-related information for each IDC scenario.

Example 1-2-1

In one embodiment of the present disclosure, an existence field may be present for at least one piece of information related to the IDC described in Example 1-1. For example, if the existence field value corresponding to a specific piece of information related to the IDC is set to 1, this indicates that a field related to the specific piece of information may be present.

Additionally or alternatively, the presence field, which indicates whether each piece of information related to the IDC exists, may be configured in the form of a bitmap (e.g., an presence bitmap). If the presence bitmap exists/is set, each bit of the presence bitmap may correspond to information related to each type of IDC. The remaining bits of the presence bitmap (e.g., bits other than each bit corresponding to information related to the IDC) may be reserved.

As an example, (a) of FIG. 13 illustrates an IDC information field (e.g., a field containing/configuring information related to IDC) utilizing an existence bitmap. As an example, each bit of the existence bitmap (e.g., B0, B1, and B2) may correspond to IDC ST information, IDC section information, and IDC channel, respectively. For example, if the first and second bits of the existence bitmap are each set to 1, this may mean that IDC ST information and IDC section information are included in the IDC information field.

Example 1-2-2

In one embodiment of the present disclosure, if an STA is unable to perform all transmission and reception operations during a given period due to an IDC, information indicating full unavailability may be transmitted and received via the IDC information field. If an STA is unable to perform transmission and reception operations on an operating channel due to an IDC, information indicating full unavailability may be indicated.

For example, if the information/subfield value indicating overall unavailability is set to 1 (e.g., if it is indicated that full transmit/receive operations cannot be performed during that time), information such as the IDC channel may not be included in the IDC information field.

For example, if the information/subfield value indicating overall unavailability is set to 0 (e.g., an IDC situation occurs but transmission and reception are indicated to be possible through other means), this may indicate partial unavailability. Here, the other means may include performing transmission and reception operations through other available channels, including subchannels. In this case, the IDC information field may include information such as the IDC channel.

Additionally or alternatively, a field may be defined and indicated as "fully unavailable", such as "partially unavailable." For example, if an IDC condition occurs but transmission and reception are indicated to be possible in another way (e.g., via another available channel, including a subchannel), the field value associated with "partially unavailable" may be set to 1. In this case, information related to the IDC channel may be included in the IDC information field. If the field value associated with "partially unavailable" is set to 0, this may indicate fully available, and the IDC information field may not include information related to the IDC channel.

Example 1-2-3

In one embodiment of the present disclosure, if an IDC occurring in an STA occurs continuously and periodically, a periodicity associated with the IDC may be indicated. For example, if the field value containing information related to the periodicity is set to 0, the IDC interval and IDC continuity may not be included in the IDC information field.

Figure 13(b) illustrates IDC information (or a field containing IDC information) that includes overall unavailability and a periodicity associated with the IDC. For example, if overall unavailability is not indicated, IDC channel information may be included in the IDC information field. Additionally, if the generated IDC does not have a periodicity, IDC interval and IDC continuity may not be included in the IDC information field.

Additionally or alternatively, complete unavailability may be indicated by a field associated with partial unavailability. The field associated with partial unavailability may be set to 1. In this case, the IDC information field may contain information related to the IDC channel. If the field associated with partial unavailability is set to 0, this may indicate complete availability, and the IDC information field may not contain information related to the IDC channel.

Additionally or alternatively, as illustrated in (c) of FIG. 13, the IDC information field may include a length field indicating the length of the IDC information field. When information related to a new type of IDC is added to the IDC information field, an STA that cannot decode the information related to the new type of IDC can use the length field to determine which field (e.g., the field containing information related to the new type of IDC) to ignore.

Additionally or alternatively, as illustrated in (c) of FIG. 13, the IDC information field may include an ID for the corresponding IDC information field (e.g., a subfield indicating the ID). The ID for the corresponding IDC information field may be used to convey control information. If the ID of the corresponding IDC information field is indicated through the subfield indicating the ID, the STA may recognize/decode the corresponding IDC information field. If the ID of information other than the IDC information field (e.g., another ID) is indicated, the STA may recognize that the corresponding field is a control field associated with an ID other than the IDC information.

Additionally or alternatively, as illustrated in (d) of FIG. 13, the IDC information field may be included in the generalized control information field. Control fields corresponding to one or more IDs may be included together/contiguously in the generalized control information field. For example, the IDC information field may be included in the generalized control information field together with other control information fields.

Additionally or alternatively, as illustrated in (d) of FIG. 13, a field related to the number of control information fields may be included in the generalized control information field. For example, if the number of control information fields is 2, the ID of the IDC information is 0, and the ID of the BSR information is 1, the generalized control information field may include an IDC information field and a BSR information field. Additionally or alternatively, the above-described field(s) may be configured in the form of an element including a length field.

Example 2

In one embodiment of the present disclosure, one or more IDC information and IDC information field(s) described in the above-described embodiments may be included in a user information field of a trigger frame. The following describes how one or more IDC information is included in the user information field of a trigger frame.

Example 2-1

In one embodiment of the present disclosure, a specific value may be set in the AID12 subfield of the user information field of the trigger frame, and the specific value may indicate that information related to IDC is included in the trigger frame. The AID12 subfield of the user information field of the trigger frame may be defined as shown in Table 3.

AID12 subfield Description 0 The user information field allocates one or more consecutive RA-RUs for the associated STA. 1-2007 The user information field is designated as the associated STA with an AID equal to the value of the AID12 subfield. 2008-2044 Reserved 2045 The user information field allocates one or more consecutive RA-RUs for an unbound STA. 2046 Unallocated RU 2047-4094 Reserved 4095 Indicates the start of a padding field, so it is not allowed in user information fields.

Here, if the trigger frame has a padding field, it may be a field in which all padding bits are set to 1. If there is a padding field, it has a length of at least 2 octets and may be located between the user information list field and the FCS field. The value of the AID12 subfield, 2007, can be used in the HE variant user information field if the trigger frame is generated from a non-EHT HE AP, but the value of the AID12 subfield, 2007, cannot be used in the HE variant user information field if the trigger frame is generated from an EHT AP.

For example, if the AID12 subfield value is 2007, this may indicate that a special user information field is included on the trigger frame in a specific wireless LAN system (e.g., an IEEE 802.11 be-based wireless LAN system).

Similarly, if the AID12 subfield value is indicated as 2006 or another reserved value (e.g., one of 2008 to 2044, or one of 2047 to 4094), this may indicate that the trigger frame contains information related to IDC (e.g., in the user information field of the trigger frame), or that the trigger frame contains an IDC user information field.

The IDC user information field may include all subfields corresponding to each of the multiple types of IDC-related information described in the above-described embodiments (e.g., embodiment 1-1). However, this is only one embodiment, and the IDC user information field may include only some of the subfields corresponding to each of the multiple types of IDC-related information.

For example, the IDC user information field may be positioned after the common information field of the trigger frame, or after the special user information field. In another example, the IDC user information field may be positioned before the start of the user-specific user information field.

As an example of the present disclosure, when the AID12 subfield value is 2006 and information for triggering IDC information is included on a trigger frame including the AID12 subfield, the user information field of the trigger frame including the IDC request field may be illustrated as in (b) of FIG. 14.

For example, if the IDC information request field value is set to 1 (or 0), this may indicate that IDC information is requested by the trigger frame. If the IDC information request field value is set to 0 (or 1), this may indicate that IDC information is not requested by the trigger frame.

Additionally or alternatively, it may be difficult to include all IDC information in a response frame of a trigger frame due to reasons such as the frame size of the response frame. Therefore, the IDC request subfield included in the user information field of the trigger frame may indicate a request for all or a specific type of IDC information.

For example, based on the IDC information request subfield value being set to 1, this may indicate/mean a request for time information related to IDC (e.g., IDC start time, IDC period, and/or IDC interval, etc.). Based on the IDC information request subfield value being set to 2, this may indicate/mean a request for channel information related to IDC. Based on the IDC information request subfield value being set to 3, this may indicate/mean a request for spatial stream information related to IDC. As an example, the IDC request user information field of the trigger frame may be illustrated as in (c) of FIG. 14.

The size of the IDC information request subfield may be determined based on the type of information being requested. For example, the IDC information request (type) subfield may be structured as shown in Table 4.

IDC Information Request explanation 0 All IDC information 1 Time information related to IDC 2 Channel information related to IDC 3 IDC spatial stream information 4-14 Reserved 15 No IDC information requested

Additionally or alternatively, the IDC information request (type) subfield may be configured as a bitmap. Accordingly, multiple types of IDC information may be requested by the IDC information request (type) subfield. For example, the first bit (B0) of the IDC information request (type) subfield, based on the LSB, may be associated with a request for all IDC information. Additionally, the second bit (B1) of the IDC information request (type) subfield may be associated with time information related to IDC, the third bit (B2) of the IDC information request (type) subfield may be associated with channel information related to IDC, and the third bit (B2) of the IDC information request (type) subfield may be associated with a spatial stream related to IDC. For example, when the IDC information request (type) subfield value is set to "0b1100", this may mean that channel information related to IDC and IDC spatial stream are requested.

However, this is only one example, and the type of information requested may vary depending on the specific value of the IDC information request (type) subfield.

In one embodiment of the present disclosure, the common information field of the trigger frame may include information indicating whether an IDC request user information field is included among the user information fields of the trigger frame. That is, the common information field may include information indicating whether an IDC request user information field exists in the trigger frame.

For example, the presence or absence of an IDC request user information field on a trigger frame may be indicated by at least one bit of the reserved bits in the common information field. For example, the reserved bit may include at least one of a reserved area that may be defined by the GI and HE/EHT-LTF type subfield encoding values described below, an EHT reserved bit of an EHT variant common information field (e.g., the 57th bit (B56) to the 63rd bit (B62)), or a reserved bit of a common information field of an MU-RTS trigger frame (e.g., a UL length field (e.g., the 5th bit (B4) to the 16th bit (B15)), or a UL spatial reuse (e.g., the 38th bit (B37) to the 53rd bit (B52)).

Additionally or alternatively, information related to an IDC information request may be indicated through at least one bit among the reserved bits in the common information field. That is, the IDC information request (type) subfield described above (e.g., the (4-bit) subfield described with reference to FIG. 14 and Table 4, etc.) may be set on the common information field. Here, since the reserved bits of the common information field have been described above, a redundant description thereof will be omitted.

Additionally or alternatively, a generic response other than a trigger-dependent response (e.g., a BSRP/BSR (buffer status report) on a QoS null) may be indicated via at least one of the reserved bits in the common information field. The form of the generic response may include a new control frame response, a new action frame, and/or a BA frame, as described in Embodiment 3 and its detailed embodiments.

Example 3

Embodiment 3 relates to a method for transmitting IDC information requested through the above-described trigger frame through a response frame. That is, Embodiment 3 relates to the structure and type of a response frame including IDC information.

Example 3-1

Example 3-1 relates to a new in-device coexistence report (IDCR) A (aggregated) control field that responds to a trigger frame. That is, Example 3-1 relates to the configuration of an A-control field that includes information related to IDC.

For the definition of new control fields (e.g., IDC and A-control fields), control IDs can be defined as in Table 5.

Control ID value meaning 0 Triggered response scheduling (TRS) 1 Operating mode (OM) 2 HE Link Adaptation (HLA)/EHT Link Adaptation (ELA) 3 Buffer status report (BSR) 4 UL Power Headroom (UPH) 5 Bandwidth query report (BQR) 6 Command and status (CAS) 7 EHT Operation Mode (EHT OM) 8 Single response scheduling (SRS) 9 AP Assistance Request (AAR) 10 In-device coexistence report (IDCR) 11-14 Reserved 15 ONES (Ones need expansion surely)

FIG. 14(d) illustrates a control information subfield of an IDCR control subfield (e.g., an A-control subfield in which a control ID value corresponds to an IDCR). For example, the control information subfield may include a subfield related to an IDC ST, a subfield related to an IDC interval, a subfield related to an IDC channel, and/or a subfield related to a maximum Rx NSS related to an IDC. However, this is only an embodiment, and the control information subfield may omit some of the above-described subfields or may have new subfields added. The IDCR may be signaled by being included in QoS data, a QoS null frame, etc. FIG. 15 is a diagram for explaining a method of transmitting IDC information via an A-control field according to an embodiment of the present disclosure. That is, FIG. 15 relates to a method of transmitting and receiving a response frame (e.g., a response frame using an A-control field) for a trigger frame including a field requesting IDC information.

Specifically, the AP can request IDC information from at least one STA via a trigger frame (e.g., a BSRP trigger frame, etc.). At least one STA can transmit a response frame (e.g., a QoS null frame) containing IDC information to the AP. For example, after receiving the trigger frame, STA 2, which knows that an IDC event/action will occur, can transmit a QoS null frame to the AP. At this time, the A-Control field of the QoS null frame can include IDC information or a control information field that can include IDC information.

Accordingly, the AP can confirm that STA 2 will have an IDC event/action and may not transmit frames to STA 2 during the period in which the IDC event/action occurs. In Fig. 15, it is assumed that the AP transmits a trigger frame, but as described above, the AP may be replaced by a non-AP STA.

Example 3-2

Example 3-2 relates to a new multiple IDCR A-control subfields that respond to a trigger frame. If IDC information is included in a single A-control field, the header size may be exceeded. Therefore, a control ID may be defined for each type of IDC information, and IDC-related information may be configured based on the A-control field(s) to which each control ID is set/mapped. For example, a control ID associated with an A-control field may be configured as shown in Table 6.

Control ID value meaning 0 Triggered response scheduling (TRS) 1 Operating mode (OM) 2 HE Link Adaptation (HLA)/EHT Link Adaptation (ELA) 3 Buffer status report (BSR) 4 UL Power Headroom (UPH) 5 Bandwidth query report (BQR) 6 Command and status (CAS) 7 EHT Operation Mode (EHT OM) 8 Single response scheduling (SRS) 9 AP Assistance Request (AAR) 10 In-device-coexistence start time (IDCS) 11 In-device coexistence duration (IDCD) 12 In-device coexistence channel and NSS (IDCCN) 11-14 Reserved 15 ONES (Ones need expansion surely)

FIG. 16 is a diagram illustrating control information subfields on IDCS, IDCD, and IDCCN subfields according to one embodiment of the present disclosure. An A-control field corresponding to an IDCS includes information about an IDC start time, an A-control field corresponding to an IDCD includes information about an IDC interval, and an A-control field corresponding to an IDCCN may include a channel and/or a maximum Rx NSS associated with the IDC. The A-control fields corresponding to each of the IDCS, IDCD, and IDCCN may be signaled via QoS data or/and a QoS null frame. In addition, reserved bits on each of the A-control fields illustrated in FIG. 16 may be omitted. In this case, the sizes of the A-control fields corresponding to each of the IDCS, IDCD, and IDCCN may be configured as 16 bits, 16 bits, and 20 bits, respectively.

Additionally or alternatively, the subfields related to the IDC channel and the subfields related to the maximum Rx NSS included in the A-control field corresponding to the IDCCN may be separated into separate A-control fields. The A-control fields related to the IDC channel and the maximum Rx NSS may be assigned/applied different control IDs. In addition, the A-control field may be configured based on a combination of one or more pieces of IDC control information, within a range not exceeding the maximum size of the A-control field.

Additionally or alternatively, a control ID for the IDC (e.g., a control ID corresponding to the IDCR in Table 5) may be defined, and one or more subtypes may be defined within the A-Control field. Each of the one or more subtypes may correspond to IDC-related information. The control ID value (or the value corresponding to the subtype) may be configured as shown in Table 7.

Control ID value meaning 0 Start time 1 panel 2 channel 3 Max Rx NSS 4 Channel + Max Rx NSS 5 - 7 Reserved

For example, as disclosed in Table 7, eight subtypes can be defined with three bits, but is not limited thereto. Depending on the number of subtypes, it can be composed of two or four bits, etc. Each control information subfield can include the IDC information described above, but is not limited thereto, and some IDC information may be omitted or new IDC information may be added.

Example 3-3

Example 3-3 relates to the configuration of an A-MPDU response including one or more types of IDC information. That is, a response frame based on an A-MPDU can be transmitted and received in order to simultaneously transmit one or more types of IDC information described above.

FIG. 18 is a diagram illustrating a control information subfield on an IDCR subfield according to one embodiment of the present disclosure. As illustrated in FIG. 18, an AP may request information related to IDC from at least one STA via a trigger frame (e.g., a BSRP trigger frame). At least one STA may transmit information related to IDC to the AP via a response frame (e.g., a QoS null frame). In this case, the response frame may include an A-control frame corresponding to the IDCR.

For example, after receiving a trigger frame, STA 2, which knows that an IDC event/action will occur, can transmit IDC-related information or a control frame that may include IDC-related information to the AP through the A-Control frame of the QoS null frame. When transmitting IDC-related information, each subtype of IDCR can be included in an A-MPDU subframe. That is, IDC-related information can be included in the A-Control field of the same frame as the QoS null frame.

For example, as illustrated in FIG. 18, MPDU#1 including an A-control frame with an IDCR subtype value set to 0 (e.g., an A-control frame of a QoS null frame) may include IDC start time information. MPDU#2 including an A-control frame with an IDCR subtype value set to 1 may include IDC interval information. In addition, MPDU#N (N is a natural number greater than or equal to 1) transmitted by STA 2 may be configured as an A-MPDU.

Accordingly, the AP can confirm that STA 2 will have an IDC event/action and may not transmit frames to STA 2 during the period in which the IDC event/action occurs. In Fig. 18, it is assumed that the AP transmits a trigger frame, but as described above, the AP may be replaced by a non-AP STA.

Example 3-4

Example 3-4 relates to a new frame (or control frame) for a trigger frame.

A new control frame may be defined for a new response frame to a trigger frame that indicates an IDC information request and/or a general response. Additionally or alternatively, a new response frame may be defined even if it does not include an IDC information request and/or a general response. For example, if the subtype value in the Frame Control field of the MAC header is set to one of 0000, 0001, and 1111, this may indicate that the corresponding response frame is a new control frame (e.g., an IDC frame) that includes IDC information.

For example, an IDC frame may be configured as shown in (a) of Fig. 19. The IDC frame may include an IDC control field and/or an IDC information field, and the IDC information field may include at least one of the IDC-related information described above.

For example, the IDC control field may include an existence bitmap indicating whether a subfield corresponding to each of the plurality of types of IDC information exists. As described above, the IDC information may include an IDC start time, an IDC interval, an IDC channel, an IDC interval, IDC-related continuity, and/or a maximum Rx NSS. The IDC control field may include information (e.g., a bitmap) indicating whether a subfield representing each of the above-described IDC information exists.

Additionally or alternatively, the new control frame may be based on the IDC information request, general response, and/or requested information contained in the trigger frame. Accordingly, the new control frame may include a response based on the trigger type of the trigger frame.

As an example, (b) of FIG. 19 is a diagram illustrating the configuration of a new control frame. The new control frame (e.g., an IDC frame) may include an IDC control field, an IDC information field, and/or an A-control field. Here, the A-control field may have the configuration of the A-control field of a basic wireless LAN system.

For example, the A-Control field (e.g., the A-Control Information subfield) may be configured as shown in Table 8. The first two bits of the A-Control field may be reserved, as they were previously used for variant indication purposes.

bit:
B0 - B1 B2 - B5 Variable Reserved Control ID Control information

For example, an A-control field (e.g., an A-control information field) related to BSR may be configured as shown in Table 9.

B0 - B1 B2 - B5 B6 - B9 B10 - B11 B12 - B13 B14 - B15 B16 - B23 B24 - B31 Reserved Control ID=0b11 ACI bitmap Delta TID ACI High Scaling factor Queue Size High Queue Size All

As described above, when the A-control field is configured, the IDC control field may include information indicating whether the A-control field is present on a new control frame. As an example of the present disclosure, the A-control field may be determined according to the type of the trigger frame. For example, when an IDC information request, a general response, and/or requested information is included on a BSRP trigger frame, the A-control field of the IDC frame may be configured based on a BSR. As another example, when an IDC information request, a general response, and/or requested information is included on an MU-RTS trigger frame, the STA may transmit a response frame based on the new control frame rather than a CTS. In this case, the IDC information may be included on the response frame, but the A-control field may be omitted.

Additionally or alternatively, the new control frame may include an IDC information request, a general response, and/or a field based on the requested information included in the trigger frame, and one or more A-control fields. For this purpose, the new control frame may include an A-control presence subfield. Figure 19(c) illustrates the configuration of a new control frame including an A-control presence subfield. Figure 19(c) is merely an example, and some of the configurations of the new control frame may be added or omitted.

Each bit of the A-control presence subfield can be matched to each control ID based on the MSB or LSB. For example, if a specific bit of the A-control presence subfield is set to 1, this may mean that an A-control field corresponding to the specific bit is present. If the A-control presence subfield includes multiple bits set to 1, this may mean that multiple A-control fields are included in the A-control list.

For example, if the bit values corresponding to each of BSR and OM in the A-control presence subfield are set to 1, the A-control list may include A-control fields corresponding to each of BSR and OM. Each bit of the A-control presence subfield may be mapped to a control ID of the A-control field. The order of the control ID values corresponding to each bit of the A-control presence subfield may be defined in various ways (e.g., sequentially, randomly, or in reverse order, etc.).

Example 3-5

Example 3-5 relates to a new response frame based on an action frame for a trigger frame.

A response frame based on an action frame may be defined for a trigger frame containing an IDC information request, a general response instruction, and/or requested information. Additionally or alternatively, a new response frame may be defined even if the trigger frame does not contain an IDC information request, a general response instruction, and/or requested information.

An action frame may contain a category field and an action detail field. If the category field value is set to one of the values 33, 38, or 125, this may indicate that the action frame is related to an IDC.

In the following, it is assumed that the category field value is set to 38 as in Table 10, but it is not limited thereto.

cord meaning ... ... 38 IDC ... ...

Depending on the category field value, the IDC action field value included in the action frame can be configured as shown in Table 11.

value meaning 0 IDC response 1 IDC + A-Control Information Response 2 A-Control Information Response 3-255 Reserved

As an example of the present disclosure, if the IDC action field value is set to 0, this may mean that an IDC response is included in the body of the action frame. Accordingly, the IDC action field may be configured as shown in Table 12.

Order Meaning 1 Category 2 One or more IDC information

As an example of the present disclosure, if the IDC action field value is set to 1, this may mean that the body of the action frame includes an IDC response and an A-control field. Accordingly, the IDC action field may be configured as shown in Table 13.

Order Meaning 1 Category 2 One or more IDC information 3 One or more A-control information

As an example of the present disclosure, if the IDC action field value is set to 2, this may mean that an A-control field is included in the body of the action frame. Accordingly, the IDC action field may be configured as shown in Table 14.

Order Meaning 1 Category 3 One or more A-control information

As an example of the present disclosure, the element ID for defining IDC information and A-control information elements can be configured as shown in Table 15.

element Element ID Element ID extension extensible fragmentable ... IDC Info 255 117 Yes No A-Control Info 255 118 Yes No ...

As an example of the present disclosure, the IDC information element may be configured as shown in Table 16.

Octet: 1 Octet: 1 Octet: 1 Octet: Variable Element ID length Element ID extension IDC Information

As an example of the present disclosure, the IDC information of the IDC information element may be configured as shown in Table 17.

Octet: 1 Octet: 1 Octet: Variable length control IDC Information

As an example of the present disclosure, the IDC information subfield may include at least one of the multiple types of IDC information described above. The presence or absence of each of the multiple types of IDC information may be indicated through a control subfield. The length of the IDC information subfield may vary depending on the type of IDC information included. As an example of the present disclosure, the A-control element may be configured as shown in Table 18.

Octet: 1 Octet: 1 Octet: 1 Octet: Variable Element ID length Element ID extension A-Control Information

As an example of the present disclosure, the A-control information subfield may include the A-control field of a basic wireless LAN system. The A-control information subfield may be configured as shown in Table 19.

bit:
B0-B1 B2 - B5 subject to change Reserved Control ID Control information

For example, an A-control field (e.g., an A-control information field) related to BSR may be configured as shown in Table 20.

B0 - B1 B2 - B5 B6 - B9 B10 - B11 B12 - B13 B14 - B15 B16 - B23 B24 - B31 Reserved Control ID=0b11 ACI bitmap Delta TID ACI High Scaling factor Queue Size High Queue Size All

As described above, when the A-control field is configured, the IDC control field may include information indicating whether the A-control field is present on a new control frame. As an example of the present disclosure, the A-control field may be determined according to the type of the trigger frame. For example, when an IDC information request, a general response, and/or requested information is included on a BSRP trigger frame, the A-control field of the IDC frame may be configured based on a BSR. As another example, when an IDC information request, a general response, and/or requested information is included on an MU-RTS trigger frame, the STA may transmit a response frame based on the new control frame rather than a CTS. In this case, the IDC information may be included on the response frame, but the A-control field may be omitted.

As an example of the present disclosure, the IDC information field may be one of the control information fields as shown in Table 7, and the A-control element ID may be assigned as shown in Table 21.

element Element ID Element ID extension extensible fragmentable ... A-Control Info 255 117 Yes No ...

At this time, A-control information/field can be defined as in Table 18, and IDC information can be additionally defined on the control ID of A-control information as in Table 5 or Table 17.

FIG. 20 is a diagram illustrating a BSRP trigger frame with a general response, according to one embodiment of the present disclosure. When a general response is indicated via a reserved bit in the common information field of the trigger frame, IDC information and/or BSRP can be simultaneously transmitted and received via a new control response based on BSRP.

An AP may transmit a BSRP trigger frame to at least one STA. At this time, a generic response indication field may be set/defined through at least one of the reserved bits described above in the common information field of the BSRP trigger frame (e.g., the EHT reserved bit of the EHT variant). At this time, the value of the generic response indication field may be set to 1. STA 1 and STA 3 (e.g., STAs that do not support IDC-related procedures) may ignore the value of the generic response indication field. STA 2 (e.g., STAs that support IDC-related procedures) may transmit an IDC frame as a response frame after interpreting the generic response indication field.

That is, STA 2 may transmit an IDC frame instead of a BSR response frame via the A-Control field of the QoS null frame. Additionally or alternatively, the IDC frame transmitted by STA 2 may include IDC information and/or BSR. An AP receiving the IDC frame may confirm that an IDC event related to STA 2 has occurred. In addition, the IDC frame may not transmit data to STA 2 during the IDC period.

BSRP related frames/fields can be defined as in Table 19 or Table 20, and the response frame can be any type of response frame (e.g., a response frame including a new action frame, a BA frame, etc.) as well as an IDC frame.

Additionally or alternatively, an STA in which an IDC event occurs may transmit a control frame/action frame according to Embodiment 3-4 and/or Embodiment 3-5 to the opposing STA unsolicited.

FIG. 21 is a diagram illustrating a method for transmitting IDC information via an unsolicited control frame and/or action frame according to one embodiment of the present disclosure.

The occurrence of an IDC event can be detected when an STA acquires transmission authority. At this time, the STA can transmit IDC information to the AP via a control frame or action frame. Accordingly, the AP can identify the IDC event period associated with the STA and, after that period, perform data transmission through an RTS/CTS exchange with the STA.

Example 3-6

Example 3-6 relates to a new response frame to a trigger frame (e.g., an action frame including an A-control field on an HT control field).

A-control information may be included in the HT control field of an action frame, and IDC information may be included in the body of the action frame. The action frame may include a category field and an action detail field. If the category field value is set to one of the values 33, 38, or 125, this may indicate that the action frame is related to an IDC.

In the following, it is assumed that the category field value is set to 38 as in Table 22, but it is not limited thereto.

cord meaning ... ... 38 IDC ... ...

Depending on the category field value, the IDC action field value included in the action frame can be configured as shown in Table 23.

value meaning 0 IDC response 1-255 Reserved

As an example of the present disclosure, if the IDC action field value is set to 0, this may mean that an IDC response is included in the body of the action frame. Accordingly, the IDC action field may be configured as shown in Table 24.

Order Meaning 1 Category 2 One or more IDC information

As an example of the present disclosure, the element ID for defining IDC information and A-control information elements can be configured as shown in Table 25.

element Element ID Element ID extension extensible fragmentable ... IDC Info 255 117 Yes No ...

As an example of the present disclosure, the IDC information element may be configured as shown in Table 26.

Octet: 1 Octet: 1 Octet: 1 Octet: Variable Element ID length Element ID extension IDC Information

As an example of the present disclosure, the IDC information of the IDC information element may be configured as shown in Table 27.

Octet: 1 Octet: 1 Octet: Variable length control IDC Information

As an example of the present disclosure, the IDC information subfield may include at least one of the multiple types of IDC information described above. The presence or absence of each of the multiple types of IDC information may be indicated via a control subfield. The length of the IDC information subfield may vary depending on the type of IDC information included.

FIG. 22 is a diagram for explaining an action frame response of a BSRP trigger frame according to one embodiment of the present disclosure.

As illustrated in FIG. 22, the AP may transmit a BSRP trigger frame to at least one STA. STA 2, where IDC is to occur, may transmit a response frame (e.g., an IDC action frame) to the AP. Here, the A-control field may be included in the HT control field of the action frame based on the trigger frame. For example, the IDC action frame may include information related to the IDC.

Specifically, the BSRP trigger frame may include an IDC information request, a general response indication, and/or requested information. A response frame to the BSRP trigger frame (e.g., a response frame composed of a new action frame) may include a BSR A-control field in the HT control area, and information related to the IDC may be included in the action frame body. For example, as illustrated in FIG. 22, an IDC action frame may include an A-control field related to the BSR and an action frame body including information related to the IDC.

According to various embodiments of the present disclosure, an STA may transmit one or more PPDUs/frames containing information related to an IDC to another STA. For example, the information related to an IDC may include the start time of the STA's IDC, the duration of the IDC, the channel or/and bandwidth of the STA affected by the IDC, the interval between the durations of the IDC, information regarding the duration of the IDC, and information indicating the presence or absence of information related to each IDC.

Additionally or alternatively, an ID indicating information related to the IDC may be included in the frame. Additionally or alternatively, one or more control information fields may be sequentially configured in the frame. Additionally or alternatively, if there are multiple control information fields, the frame may include information regarding the number of control information fields.

Additionally or alternatively, the PPDU/frame transmitted by the STA may be a response to a trigger frame. The response to the trigger frame may include an A-Control field, a new IDCR A-Control field, and/or multiple IDCR A-Control fields. The new multiple IDCR A-Control fields may be configured as an A-MPDU response frame.

Additionally or alternatively, a response to a trigger frame may include a new control frame, a new action frame, or an action frame including an A-control field in the HT control area.

Additionally or alternatively, when a STA transmits IDC information of another STA, the above-described IDC information may include IDC information for an STA other than the STA in question.

In one embodiment of the present disclosure, another STA that receives one or more PPDUs/frames containing IDC information from an STA may perform frame detection. Through frame detection, the other STA may determine whether to transmit and the transmission capabilities of the STA in the IDC section.

For example, a request for IDC information may be included in the user information list of the trigger frame. Additionally or alternatively, whether a request for IDC information is included in the user information list may be indicated by at least one of the reserved bits in the common information field of the trigger frame.

Additionally or alternatively, a request for IDC information may be indicated by at least one of the reserved bits of the common information field of the trigger frame. Additionally or alternatively, a request for IDC information may be indicated by at least one of the reserved bits of the common information field specifying a general response to the trigger frame. Additionally or alternatively, a request for IDC information may be indicated by at least one of the reserved bits of the common information field specifying a general response to the trigger frame, and a request for IDC information may be indicated depending on the type of the general response.

Additionally or alternatively, a request for IDC information may be indicated by at least one reserved bit of the common information field of the trigger frame. For example, the requested information may be indicated or indexed by a bitmap.

Additionally or alternatively, a requested information flag for the trigger frame may be set by at least one of the reserved bits of the common information field, and the requested information flag may indicate that the requested information is to be included in the response frame. The requested information (e.g., the user information field and/or padding) may be included on the response frame of the trigger frame.

Additionally or alternatively, a request for IDC information may be made by a new IDC trigger frame. Additionally or alternatively, if an STA transmits IDC information of another STA, the IDC information described above may be IDC information for an STA other than the STA in question.

FIG. 23 is a diagram illustrating a PPDU transmission and reception procedure between a transmitting STA and a receiving STA according to one embodiment of the present disclosure. Some of the steps shown in FIG. 23 may be omitted depending on circumstances and/or settings. The transmitting device and the receiving STA may be APs and/or non-AP STAs.

The transmitting STA may obtain control information related to the aforementioned tone plan (or RU/DRU) (S105). The control information related to the tone plan may include the size and location of the RU, control information related to the RU, information about the frequency band in which the RU is included, information about the STA receiving the RU, etc.

The transmitting STA may configure/generate a PPDU based on the acquired control information (S110). Configuring/generating a PPDU may mean configuring/generating each field of the PPDU. That is, the step of configuring/generating a PPDU may include a step of configuring U-SIG and UHR-SIG-A/B/C fields that contain control information regarding a tone plan.

That is, the step of configuring/generating a PPDU may include a step of configuring a field including control information (e.g., N bitmap) indicating the size/position of the RU and/or a step of configuring a field including an identifier (e.g., AID) of an STA receiving the RU.

Additionally, the step of configuring/generating a PPDU may include a step of generating an STF/LTF sequence to be transmitted via a specific RU. The STF/LTF sequence may be generated based on a preset STF generation sequence/LTF generation sequence.

Additionally, the step of constructing/generating a PPDU may include a step of generating a data field (i.e., an MPDU) to be transmitted via a specific RU.

The transmitting STA can transmit the configured/generated PPDU to the receiving STA (S115).

Specifically, the transmitting STA can perform at least one of cyclic shift diversity (CSD), spatial mapping, inverse discrete Fourier transform (IDFT)/inverse fast Fourier transform (IFFT) operation, and guard interval (GI) insertion operation.

The receiving STA can decode the PPDU and obtain control information related to the tone-plan (or RU) (S120).

Specifically, the receiving STA can decode the L-SIG and U-SIG/UHR-SIG of the PPDU based on the L-STF/LTF, and obtain information included in the L-SIG and U-SIG, UHR-SIG fields. Information about various tone plans (i.e., RUs) of the present disclosure can be included in the U-SIG/UHR-SIG (UHR-SIG-A/B/C, etc.), and the receiving STA can obtain information about the tone plan (i.e., RU) through the EHT-SIG.

The receiving STA can decode the remaining portion of the PPDU based on the information about the acquired tone plan (i.e., RU) (S125). For example, the receiving STA can decode the STF/LTF field of the PPDU based on the information about the tone plan (i.e., RU). In addition, the receiving STA can decode the data field of the PPDU based on the information about the tone plan (i.e., RU) and obtain the MPDU included in the data field.

Additionally, the receiving STA may perform a processing operation to forward the decoded data to a higher layer (e.g., the MAC layer). Furthermore, if the higher layer instructs the PHY layer to generate a signal in response to the data forwarded to the higher layer, the receiving STA may perform a subsequent operation.

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.

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.

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.

The method proposed in this disclosure is 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 (16)

A step of receiving a trigger frame for requesting in-device coexistence (IDC) information from a second STA by a first station (STA); and A step of transmitting a response frame to the second STA by the first STA based on the trigger frame, The response frame includes at least one aggregated (A)-control field related to the IDC information, A method wherein the IDC information includes information about the time at which an operation related to the IDC starts and information about the duration of the operation related to the IDC. In the first paragraph, A method wherein the operation related to the IDC includes an operation in which a situation occurs in which the entire operating channel of the first STA or at least one subchannel of the entire operating channel is unavailable. In the first paragraph, Based on the inclusion of a single A-control field on the above response frame: The single A-control field comprises i) a control ID value subfield and ii) at least one subfield containing the IDC information, A method wherein the above control ID value subfield is set to one of 10 to 14. In the first paragraph, A method based on the inclusion of a plurality of A-control fields on the response frame: wherein the plurality of A-control fields include a first A-control field including information about a time at which an operation related to the IDC starts and a second A-control field including information about a period of an operation related to the IDC. In paragraph 4, The control ID value of the first A-control field is set to the first value among 10 to 14, A method wherein the control ID value of the second A-control field is set to a second value different from the first value among 10 to 14. In the first paragraph, A method wherein the IDC information includes at least one of information about a channel or bandwidth in which an operation related to the IDC occurred, information about the number of spatial streams related to the operation related to the IDC, or information about an antenna available during an interval of an operation related to the IDC. In the first paragraph, A method in which a variant of the above trigger frame is a Buffer Status Report Poll (BSRP). In the first paragraph, A method wherein information about the time at which an operation related to the IDC starts includes information about a partial timing synchronization function (TSF) time at which an operation related to the IDC is expected to start. In the first paragraph, The interval of the action related to the above IDC includes the length of the time interval during which the action related to the above IDC is expected to continue, A method wherein the above time interval length is set based on a specific unit time. In the first paragraph, The above response frame is transmitted to the second STA within a transmission opportunity (TXOP) of the second STA, A method in which communication between the first STA and the second STA is performed within a section excluding a section of an operation related to the IDC. In the first paragraph, The above first STA is a non-access point (AP) STA, A method wherein at least one STA is an AP. In the first STA, the first STA: one or more transmitters and receivers; and comprising one or more processors connected to said one or more transceivers, Receiving a trigger frame for soliciting in-device coexistence (IDC) information from a second STA through one or more transceivers; and It is set to transmit a response frame to the second STA through the one or more transceivers based on the trigger frame, The response frame includes at least one aggregated (A)-control field related to the IDC information, The IDC information includes information about the time at which an operation related to the IDC starts and information about the duration of the operation related to the IDC. A step of transmitting a trigger frame for soliciting in-device coexistence (IDC) information by a second station (STA) to at least one STA including a first STA; and A step of receiving a response frame from the first STA by the second STA based on the trigger frame, The response frame includes at least one aggregated (A)-control field related to the IDC information, A method wherein the IDC information includes information about the time at which an operation related to the IDC starts and information about the duration of the operation related to the IDC. 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 for soliciting in-device coexistence (IDC) information to at least one STA including a first STA through the one or more transceivers; and Based on the trigger frame, a response frame is set to be received from the first STA through the one or more transceivers, The response frame includes at least one aggregated (A)-control field related to the IDC information, The second STA, wherein the IDC information includes information about the time at which an operation related to the IDC starts and information about the duration of the operation related to the IDC. A processing device configured to control a first station (STA) in a wireless local area network (WLAN) system, the processing device comprising: 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 for performing a method according to any one of claims 1 to 11 based on execution by said one or more processors. 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 in a wireless LAN system to perform a method according to any one of claims 1 to 11.