Method and apparatus for announcing in-device coexistence service period in wireless LAN system

Abstract

A method and an apparatus for announcing an in-device coexistence (IDC) period in a wireless LAN system are disclosed. The method according to one embodiment of the present disclosure may comprise steps in which a first station (STA): generates a target wake time (TWT) element; and transmits a first frame including the TWT element to one or more second STAs. The TWT element includes a request type field, the request type field includes a broadcast TWT recommendation field, and the broadcast TWT recommendation field can indicate that the TWT element includes information related to in-device coexistence (IDC).

Description

Method and device for notifying the device-to-device coexistence service period in a wireless LAN system

[0001] The present disclosure relates to a method and apparatus for announcing an in-device coexistence (IDC) service period in a wireless local area network (WLAN) system.

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

[0003] To provide a more advanced wireless communication environment, improved technologies for Extremely High Throughput (EHT) are being discussed. For example, technologies for Multiple Input Multiple Output (MIMO), which supports increased bandwidth, efficient utilization of multiple bands, and increased spatial streams, and for coordination of multiple access points (APs), are being studied. In particular, various technologies are being studied to support low latency or real-time traffic. Furthermore, new technologies are being discussed to support ultra-high reliability (UHR), including improvements or extensions of EHT technology.

[0004] The technical problem of the present disclosure is to provide a method and device for notifying the IDC service period of a device to other device(s) in a wireless LAN system.

[0005] 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.

[0006] A method according to one aspect of the present disclosure may include generating a target wake time (TWT) element by a first station (STA); and transmitting, by the first STA, a first frame including the TWT element to one or more second STAs. The TWT element may include a request type field, the request type field including a broadcast TWT recommendation field, and the broadcast TWT recommendation field may indicate that the TWT element includes information related to intra-device coexistence (IDC).

[0007] A method according to an additional aspect of the present disclosure may include receiving, by a second station (STA), a first frame including a target wake time (TWT) element from a first STA; and performing, by the second STA, an IDC operation based on information included in the TWT element. The TWT element may include a request type field, the request type field including a broadcast TWT recommendation field, and the broadcast TWT recommendation field may indicate that the TWT element includes information related to intra-device coexistence (IDC).

[0008] According to the present disclosure, a method and device for notifying an IDC service period of a device to other device(s) may be provided.

[0009] 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.

[0010] 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.

[0011] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0012] FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0013] FIG. 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

[0014] FIG. 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0015] FIG. 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0016] 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.

[0017] FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0018] FIG. 8 is a drawing illustrating an example of an individual TWT operation to which the present disclosure can be applied.

[0019] FIG. 9 is a diagram illustrating an example of a broadcast TWT operation to which the present disclosure can be applied.

[0020] Figure 10 is a drawing for explaining an example of a TWT information element format.

[0021] Figure 11 is a diagram illustrating examples of individual TWT parameter set field formats.

[0022] Figure 12 is a diagram illustrating examples of broadcast TWT parameter set field formats.

[0023] FIG. 13 is a diagram illustrating an example of a collision caused by an IDC to which the present disclosure can be applied.

[0024] FIG. 14 is a diagram showing an example of the operation of the first STA according to the present disclosure.

[0025] FIG. 15 is a diagram showing an example of the operation of a second STA according to the present disclosure.

[0026] FIG. 16 is a diagram illustrating examples of an IDC event notification signaling procedure according to the present disclosure.

[0027] Figure 17 illustrates additional examples of IDC information fields according to the present disclosure.

[0028] FIG. 18 illustrates examples of TWT control fields according to the present disclosure.

[0029] Figure 19 illustrates examples of request type fields according to the present disclosure.

[0030] FIG. 20 illustrates examples of broadcast TWT parameter set fields according to the present disclosure.

[0031] FIG. 21 is a diagram showing examples of IDC-related information fields according to the present disclosure.

[0032] FIG. 22 is a diagram illustrating an example of an IDC event update notification operation according to the present disclosure.

[0033] FIG. 23 illustrates an exemplary format of an IDC TWT element according to the present disclosure.

[0034] FIG. 24 is a diagram illustrating an additional example of an IDC event notification signaling procedure according to the present disclosure.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] Below, technical features to which examples of the present disclosure can be applied are described.

[0042] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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).

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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 connected to one or more processors (102, 202) and can transmit and receive wireless signals. For example, one or more processors (102, 202) can control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be coupled to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, or the like, as referred to in the descriptions, functions, procedures, proposals, methods, and / or operational flowcharts disclosed in the present disclosure, via one or more antennas (108, 208). In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert received user data, control information, wireless signals / channels, etc. from RF band signals to baseband signals in order to process the received user data, control information, wireless signals / channels, etc. using one or more processors (102, 202).One or more transceivers (106, 206) may convert user data, control information, wireless signals / channels, etc. processed by one or more processors (102, 202) from baseband signals to RF band signals. For this purpose, one or more transceivers (106, 206) may include an (analog) oscillator and / or filter.

[0053] 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.

[0054] 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.

[0055] FIG. 2 is a diagram showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0056] 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.

[0057] 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.

[0058] 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).

[0059] 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.

[0060] 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.

[0061] 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).

[0062] 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.

[0063] Data transmitted from one of the STA(s) associated with an AP to the STA address of that AP is always received on an uncontrolled port and can be processed by an IEEE 802.1X port access entity. In addition, if the controlled port is authenticated, the transmitted data (or frame) can be forwarded to the DS.

[0064] In addition to the structure of the DS described above, an extended service set (ESS) may be established to provide wider coverage.

[0065] 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.

[0066] 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.

[0067] FIG. 3 is a diagram for explaining a link setup process to which the present disclosure can be applied.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] For example, the association request frame may include information about various capabilities, a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, RSN, 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.

[0078] 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.

[0079] 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.

[0080] FIG. 4 is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0081] 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.

[0082] 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).

[0083] Referring to Fig. 4, an operation based on a random backoff period is described. When a medium that was occupied / busy changes to an idle state, multiple STAs can attempt to transmit data (or frames). To minimize collisions, each STA can select a random backoff count, wait for the corresponding slot time, and then attempt transmission. The random backoff count has a pseudo-random integer value and can be determined as one of the values ​​in the range of 0 to CW. Here, CW is a contention window parameter value. The CW parameter is given an initial value of CWmin, but can take a value doubled in case of transmission failure (e.g., when an ACK for a transmitted frame is not received). When the CW parameter value becomes CWmax, data transmission can be attempted while maintaining the CWmax value until data transmission is successful, and if data transmission is successful, it is reset to the CWmin value. The CW, CWmin, and CWmax values ​​are 2. n It is desirable to set it to -1 (n=0, 1, 2, ...).

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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.

[0088] FIG. 5 is a diagram for explaining a CSMA / CA-based frame transmission operation to which the present disclosure can be applied.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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 are described below with reference to FIG. 7.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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).

[0106] FIG. 7 is a diagram illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0107] 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)).

[0108] 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).

[0109] 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)).

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal SIGNAL), and EHT-SIG fields can be encoded and modulated so that even legacy STAs can attempt demodulation and decoding, and can be 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 so that they can be demodulated and decoded by an STA that has successfully decoded a non-legacy SIG (e.g., U-SIG and / or EHT-SIG) and obtained the information contained in the corresponding field, and can be mapped based on a predetermined subcarrier frequency interval (e.g., 78.125 kHz). These can be referred to as EHT modulated fields.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] 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.

[0122] 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.).

[0123] 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.

[0124] 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.

[0125] 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.

[0126] 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.).

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] target wake time (TWT)

[0137] Below, we explain TWT (target wake time).

[0138] TWT is a power saving technology that can improve the energy efficiency of non-AP STAs by defining a service period (SP) between APs and non-AP STAs and sharing information about the SP to reduce contention of the medium. In the TWT setup phase, an STA that performs requests / suggestions / demands, etc., can be called a TWT requesting STA. In addition, an AP that responds to the request with an acceptance / rejection, etc., can be called a TWT responding STA. The setup phase can include a process of determining / defining a TWT request from an STA to the AP, the type of TWT operation to be performed, and the type of frames to be transmitted and received. TWT operations can be divided into individual TWT and broadcast TWT.

[0139] FIG. 8 is a drawing illustrating an example of an individual TWT operation to which the present disclosure can be applied.

[0140] Individual TWT is a mechanism in which an AP and a non-AP STA negotiate the awake / doze status of a non-AP STA by sending and receiving TWT request / response frames, and then exchange data. In the example of Fig. 8, an AP and STA1 can form a trigger-enabled TWT agreement through a TWT request frame and a TWT response frame. Here, the method used by STA1 is a solicited TWT method, in which STA1 transmits a TWT request frame to the AP, and STA1 receives information for TWT operation from the AP through a TWT response frame. On the other hand, STA2, which performs the unsolicited TWT method, can receive information about the trigger-enabled TWT agreement setup from the AP through the unsolicited TWT response. Specifically, STA2 can calculate the next TWT by adding a specific number to the current TWT value. During the trigger-enabled TWT SP, the AP can transmit a trigger frame to the STAs. The trigger frame can inform the STAs that the AP has buffered data. In response, STA1 can inform the AP of its awake state by transmitting a PS-Poll frame. Additionally, STA2 can inform the AP of its activated state by transmitting a QoS Null frame. Here, the data frames transmitted by STA1 and STA2 can be frames in the TB PPDU format. The AP, which has checked the status of STA1 and STA2, can transmit DL MU PPDU to the activated STAs.When the corresponding TWT SP expires, STA1 and STA2 can enter doze state.

[0141] FIG. 9 is a diagram illustrating an example of a broadcast TWT operation to which the present disclosure can be applied.

[0142] Broadcast TWT is a TWT in which a non-AP STA (or TWT scheduling STA) obtains information such as target beacon transmission time (TBTT) and listen interval by transmitting and receiving TWT request / response frames with the AP (or TWT scheduled STA). Here, a negotiation operation for TBTT may be performed. Based on this, the AP can define a frame to include TWT scheduling information through a beacon frame. In Fig. 9, STA1 performs a requested TWT operation, and STA2 performs an unsolicited TWT operation. The AP can transmit a DL MU PPDU after checking the awake status of the STAs through the trigger transmitted by itself. This may be the same as the process of an individual TWT. In broadcast TWT, a trigger-enabled TWT SP including a beacon frame may be repeated multiple times at a regular cycle.

[0143] Transmission of TWT information can be accomplished through a TWT information frame and a TWT information element.

[0144] The TWT information frame is transmitted by an STA to request or convey information about a TWT agreement, and is transmitted by one of the STAs of an existing TWT agreement. The action frame of the TWT information frame includes a TWT information field. The TWT Information field may include a 3-bit TWT flow identifier subfield, a 1-bit response requested subfield, a 1-bit next TWT request subfield, a 2-bit next TWT subfield size subfield, a 1-bit all TWT subfield, and a 0 / 32 / 48 / 64-bit next TWT subfield.

[0145] Figure 10 is a drawing for explaining an example of a TWT information element format.

[0146] TWT information elements can be transmitted and received in beacons, probe responses, (re)association response frames, etc. The TWT information elements can include an element identifier (ID) field, a length field, a control field, and a TWT parameter information field.

[0147] The control fields of a TWT information element have the same format regardless of whether it is an individual TWT or a broadcast TWT.

[0148] The NDP paging indicator subfield can have a value of 1 if the NDP paging field exists, and a value of 0 if the NDP paging field does not exist.

[0149] The responder PM mode subfield may indicate a power management (PM) mode.

[0150] The negotiation type subfield may indicate whether the information contained in the TWT element is about negotiation of parameters of a broadcast TWT or individual TWT(s), or about a wake TBTT interval.

[0151] For example, if the negotiation type subfield has a value of 0, the TWT subfield is for a future individual TWT SP start time, and the TWT element contains one individual set of TWT parameters. This may correspond to an individual TWT negotiation between a TWT requesting STA and a TWT responding STA, or to an individual TWT announcement by a TWT responder.

[0152] For example, if the value of the Agreement Type subfield is 1, the TWT subfield is for the next TBTT time, and the TWT element contains one individual set of TWT parameters. This may correspond to the wake TBTT and wake interval negotiation between the TWT scheduled STA and the TWT scheduling AP.

[0153] For example, if the value of the Agreement Type subfield is 2, the TWT subfield is for a future broadcast TWT SP start time, and the TWT element contains one or more broadcast TWT parameter sets. This may correspond to providing a broadcast TWT schedule to a TWT-scheduled STA by including the TWT element in a broadcast management frame transmitted by the TWT scheduling AP.

[0154] For example, if the value of the Agreement Type subfield is 3, the TWT subfield is for a future broadcast TWT SP start time, and the TWT element contains one or more sets of broadcast TWT parameters. This may correspond to managing membership in a broadcast TWT schedule by including the TWT element in individually addressed management frames transmitted by either the TWT-scheduling STA or the TWT-scheduling AP.

[0155] If the TWT information frame disabled subfield is set to 1, it indicates that reception of TWT information frames by the STA is disabled, otherwise it may be set to 0.

[0156] The wake duration unit subfield indicates the unit of the nominal minimum TWT wake duration field. The wake duration unit subfield may be set to 0 if the unit is 256 us and set to 1 if the unit is TU. For non-HE / EHT STAs, the wake duration unit subfield may be set to 0.

[0157] The most significant bit (MSB) of the agreement type field may correspond to a broadcast field. If the broadcast field is 1, a TWT element may contain one or more broadcast TWT parameter sets. If the broadcast field is 0, only one individual TWT parameter set may be contained in the TWT element. A TWT element with the broadcast field set to 1 may be referred to as a broadcast TWT element.

[0158] Fig. 11 is a diagram illustrating examples of individual TWT parameter set field formats. Fig. 12 is a diagram illustrating examples of broadcast TWT parameter set field formats.

[0159] The TWT parameter information field included in the TWT element of Fig. 10 may have a different configuration depending on the individual TWT or broadcast TWT.

[0160] For individual TWTs, the TWT parameter information field within the TWT element contains a single individual TWT parameter set field.

[0161] In the case of a broadcast TWT, the TWT parameter information field within the TWT element contains one or more broadcast TWT parameter set fields. Each broadcast TWT parameter set may contain specific information about one broadcast TWT.

[0162] As illustrated in FIGS. 11 and 12, the individual TWT parameter set field and the broadcast TWT parameter set field include common subfields.

[0163] The request type subfield may be the same size as the individual TWT parameter set field and the broadcast TWT parameter set field, but may have different detailed configurations. This will be described later.

[0164] The target wake time subfield indicates the start time of the upcoming individual / broadcast TWT SP.

[0165] The nominal maximum TWT wake duration subfield indicates the minimum interval during which a TWT requesting STA expects to wake up to complete a frame exchange associated with a TWT flow identifier during the TWT wake interval duration. Here, the TWT wake interval may mean the average time between consecutive TWT SPs expected by the TWT requesting STA.

[0166] The TWT Wake Interval Mantissa subfield can be expressed as a binary value of the TWT wake interval value in microseconds.

[0167] Referring to Figure 11, the TWT group assignment subfield, TWT channel, and NDP paging subfield are included only in the individual TWT parameter set fields.

[0168] The TWT Group Assignment subfield provides the TWT requesting STA with information about the TWT group to which the STA is assigned. This information can be used to calculate the TWT value within the TWT group. The TWT value of the STA may be equal to the value of the zero offset multiplied by the value of the TWT offset multiplied by the value of the TWT unit.

[0169] The TWT Channel subfield indicates a bitmap indicating allowed channels. When transmitted by a TWT requesting STA, the TWT Channel subfield may include a bitmap indicating a channel that the STA requests to use as a temporary default channel during the TWT SP. When transmitted by a TWT responding STA, the TWT Channel subfield may include a bitmap indicating a channel on which the TWT request is allowed.

[0170] The NDP paging subfield is optional and may include information such as an identifier of the STA being paged, the maximum number of TWT wake intervals between NDP paging frames, etc.

[0171] Referring to FIG. 12, the broadcast TWT info subfield is included only in the broadcast TWT parameter set field. The broadcast TWT info subfield may include a 3-bit reserved bit, a 5-bit broadcast TWT identifier (ID) subfield, and an 8-bit broadcast TWT persistence subfield. The broadcast TWT identifier subfield indicates the broadcast ID of a specific broadcast TWT for which an STA requests participation or provides TWT parameters, depending on the value of the TWT setup command subfield of the TWT element. The broadcast TWT persistence subfield indicates the number of TBTTs planned in the schedule of the broadcast TWT.

[0172] Next, we will explain the detailed configuration of the request type subfield.

[0173] First, the format of the request type subfield of the individual TWT parameter set field is described with reference to FIG. 11.

[0174] The TWT request subfield can indicate whether the STA is a requesting STA or a responding STA. If the value is 1, it indicates that the STA is a TWT requesting STA or a scheduled STA, and if it is 0, it indicates that the STA is a TWT responding STA or a scheduling AP.

[0175] The TWT setup command subfield can represent commands such as Request, Suggest, Demand, Accept, Alternate, Dictate, and Reject.

[0176] The trigger subfield indicates whether a trigger frame is used in the TWT SP. If the value is 1, the trigger is used, and if it is 0, the trigger is not used.

[0177] The implicit subfield can indicate whether the TWT is implicit or explicit. A value of 1 indicates implicit TWT, while a value of 0 indicates explicit TWT.

[0178] The flow type subfield may indicate the type of interaction between a TWT requesting STA (or a TWT-scheduled STA) and a TWT responding STA (or an AP that schedules the TWT). If the value is 1, it may mean announced TWT, in which the STA sends a wake-up signal to the AP by transmitting a PS-Poll or APSD (automatic power save delivery) trigger frame before a non-trigger frame is transmitted from the AP to the STA. If the value is 0, it may mean unannounced TWT.

[0179] The TWT flow identifier subfield may contain a 3-bit value that uniquely identifies specific information about the TWT request in other requests made between the same TWT requesting STA and TWT responding STA pair.

[0180] The TWT wake interval exponent subfield can set the TWT wake interval value in binary microseconds. For individual TWTs, this can mean the interval between individual TWT SPs. The TWT wake interval of the requesting STA can be defined as [TWT Wake Interval Mantissa * 2 * TWT Wake Interval Exponent].

[0181] The TWT protection subfield can indicate whether a TWT protection mechanism is used. If the value is 1, TXOPs within a TWT SP can be initiated with a NAV protection mechanism, such as (MU)RTS / CTS or CTS-to-self frames. If the value is 0, the NAV protection mechanism may not be applied.

[0182] Referring to FIG. 12, some of the subfields of the request type subfield of the broadcast TWT parameter set field are common to the subfields of the request type subfield of the individual TWT parameter set fields, and therefore, a description thereof is omitted. The subfields included only in the broadcast TWT parameter set are described below.

[0183] The Last Broadcast Parameter Set subfield indicates whether this is the last broadcast TWT parameter set. A value of 1 indicates that this is the last broadcast TWT parameter set, while a value of 0 indicates that there is a next broadcast TWT parameter set.

[0184] The Broadcast TWT Recommendation subfield may indicate recommendations for the frame types transmitted by the AP during a Broadcast TWT SP, with values ​​from 1 to 7.

[0185] The last bit of the Request Type subfield of the Broadcast TWT Parameter Set field may be reserved.

[0186] With the recent explosion in wired and wireless traffic, latency-sensitive traffic has also increased significantly. Latency-sensitive traffic includes real-time audio / video transmission, and the proliferation of multimedia devices has increased the need to support this traffic in wireless environments. However, supporting latency-sensitive traffic in wireless environments requires more considerations than in wired environments. This is because wireless environments have lower transmission speeds and must also consider interference from surrounding environments. In particular, in WLAN systems, multiple STAs must compete equally for medium access in the Industry-Science-Medical (ISM) band, making it relatively more difficult to support latency-sensitive traffic compared to cellular communication networks, which rely on centralized radio resource scheduling. This disclosure describes a novel approach for supporting latency-sensitive traffic in WLAN systems.

[0187] In the present disclosure, latency may refer to latency defined in the IEEE 802.11 series standards. For example, it may refer to the time from when a frame to be transmitted enters the queue of the MAC layer of the transmitting STA, until the transmitting STA successfully completes transmission in the PHY layer, and the transmitting STA receives an ACK / block ACK, etc. from the receiving STA, and the corresponding frame is deleted from the MAC layer queue of the transmitting STA. In addition, in the present disclosure, a non-AP STA that supports transmission of latency-sensitive data may be referred to as a low latency STA. In addition, data other than latency-sensitive data may be referred to as regular data.

[0188] Restricted TWT (r-TWT) can support securing data transmission possibility for low-latency STAs transmitting latency-sensitive data preferentially over other STAs by having the AP set a special broadcast TWT for the low-latency STAs. The STAs can establish membership in one or more r-TWT schedules with respect to the AP. Here, the r-TWT agreement can be established by the same process as the broadcast TWT agreement, and the broadcast TWT element for this can be defined to include an r-TWT parameter set field. For example, the r-TWT parameter set can refer to a specific broadcast TWT parameter set field that is distinct from other broadcast TWT parameter set fields. That is, the r-TWT parameter set field can correspond to a special case of the broadcast TWT parameter set field. In addition, the AP can announce an r-TWT SP.

[0189] Basically, if another STA supporting r-TWT operation is a TXOP holder, the TXOP must end before the start time of the r-TWT SP advertised by the associated AP. Accordingly, the STA related to the r-TWT (i.e., the low-latency STA) can transmit and receive traffic with priority over the other STAs within the r-TWT SP.

[0190] In the present disclosure, a low-latency STA associated with a specific r-TWT, as described above, is referred to as a member r-TWT scheduled STA, and other STAs are referred to as non-member STAs. A non-member STA may be an STA that has the capability to support r-TWT operation but is not a member of any r-TWT, or that supports r-TWT operation but is a member of another r-TWT, or that does not have the capability to support r-TWT operation.

[0191] An STA (e.g., a low-latency STA) that supports limited SP (or r-TWT SP) operation of broadcast TWT can inform the AP that it needs to transmit latency-sensitive data based on r-TWT operation. If the AP supports r-TWT operation / mode, the AP can transmit a frame containing scheduling information of TWTs requested by each STA to the low-latency STA and other STA(s). For example, in order to perform operation for r-TWT, non-AP STAs can obtain r-TWT related information from the AP through a beacon frame, a probe response frame, a (re)association response frame, or other frames in an undefined format (e.g., frames for broadcast, advertisement, or announcement purposes).

[0192] According to the restricted TWT operation, a separate TXOP (i.e., to which access of other STAs is restricted) can be secured within the r-TWT SP by using a NAV such as (MU) RTS / CTS or CTS-to-self, or a quiet interval. Before a specific r-TWT SP starts, if there is a TXOP of another STA (i.e., a non-member STA) other than the STA having the membership for the specific r-TWT schedule, it must be stopped. And the TXOP of the other STA (i.e., the non-member STA) can be additionally performed after the specific r-TWT SP ends.

[0193] In-Device Coexistence (IDC) Operation

[0194] Wi-Fi wireless communication technology can be used together with non-Wi-Fi wireless communication technologies in similar frequency bands (e.g., 2.4 GHz, 5 GHz, 6 GHz, etc.). For example, non-Wi-Fi wireless communication technologies may include various wireless communication technologies such as Bluetooth, Zigbee, and UWB (ultra wide band). A single device (e.g., a smartphone, smartwatch, AR / VR device, etc.) may support both Wi-Fi and non-Wi-Fi wireless communication technologies, and when transmission and reception according to different wireless communication technologies coexist simultaneously on the same or adjacent frequency bands, problems such as reduced transmission throughput and increased latency may occur due to mutual interference, packet loss, and rate degradation.

[0195] Furthermore, even when smart devices such as smartphones support mobile AP or soft AP functionality, the IDC problem, where Wi-Fi and non-Wi-Fi transmission and reception coexist simultaneously, can occur. In this case, unnecessary operations (e.g., failed attempts to exchange data on the Wi-Fi channel) may occur frequently and repeatedly on other smart devices connected to the AP, which may lead to power consumption issues.

[0196] FIG. 13 is a diagram illustrating an example of a collision caused by an IDC to which the present disclosure can be applied.

[0197] The example of Fig. 13 illustrates an example of how an IDC event periodically occurs in an AP, affecting medium access of STAs. For example, an AP may periodically exchange data with a non-Wi-Fi device. While the AP is performing a non-Wi-Fi transmission (or reception), the initial control frame (ICF), such as the RTS, transmitted by STA1 and / or STA2 within the BSS to transmit data may collide with the non-Wi-Fi transmission transmitted by the AP or the non-Wi-Fi device. As a result, a situation may occur in which the AP cannot hear the RTS frame from STA1 / STA2. In this case, a situation may occur in which STAs within the BSS continuously attempt to transmit RTS due to data transmission failures. As a result, STA1 / STA2 may continuously consume power in an active state while failing to successfully exchange Wi-Fi data.

[0198] To address this issue, one could consider transmitting information about non-Wi-Fi transmissions and receptions exchanged between the AP and non-Wi-Fi devices to STAs within the BSS. This would allow STAs within the BSS to remain in a sleep state during non-Wi-Fi transmissions and receptions, minimizing power consumption.

[0199] This disclosure describes various examples of announcing information about an IDC of a device to other device(s).

[0200] Although various examples of the present disclosure are described based on a TWT setup frame or beacon frame containing a TWT element, examples in which IDC-related information according to the examples of the present disclosure is included in elements of other names (e.g., IDC elements) and / or frames of other names (e.g., IDC frames) may also be included within the scope of the present disclosure.

[0201] Furthermore, the scope of the present disclosure is not limited by the names of the fields in the examples of the present disclosure, and the examples of the present disclosure may also be applied to fields with other names. Furthermore, in the examples below, the term "field" may be replaced with "subfield," and the term "subfield" may be replaced with the term "field."

[0202] FIG. 14 is a diagram showing an example of the operation of the first STA according to the present disclosure.

[0203] In step S1410, the first STA can generate a TWT element.

[0204] As in the format of the TWT element described above, the TWT element may include a control field and a TWT parameter information field. The TWT parameter information field may include one or more broadcast (or individual) TWT parameter set fields. For example, the broadcast TWT parameter set field may include a request type field. For example, the request type field may include a broadcast TWT recommendation field.

[0205] In some examples, the Broadcast TWT Recommendation field within the Request Type field within a TWT element may indicate that the TWT element contains information related to the IDC. For example, the Broadcast TWT Recommendation field may be set to a value of one of 5 to 7.

[0206] In some examples, the Agreement Type field within the Control field within the TWT element may be set to a value corresponding to broadcast. For example, the Agreement Type field may be set to a value of 2.

[0207] In some examples, information related to IDC may include information about resources related to IDC. Resources related to IDC may be specified by time resources, frequency resources, and / or spatial resources. For example, information about time resources may include a start time, a duration, an interval, a continuity, an end time, and / or a number of time units. For example, information about frequency resources may include a bandwidth, a frequency range, a center frequency, a channel, and / or a resource unit. For example, information about spatial resources may include an antenna index, a number of antennas, a spatial stream index, and / or a number of spatial streams.

[0208] In some examples, information about resources related to IDC may include information about available resources and / or unavailable resources. For example, if information about available resources for time / frequency / space is indicated, unavailable resources may correspond to the remaining resources for all time / frequency / space, excluding available resources. For example, if information about unavailable resources for time / frequency / space is indicated, available resources may correspond to the remaining resources for all time / frequency / space, excluding unavailable resources. For example, information about available resources may be provided for one or more of time / frequency / space, and information about unavailable resources may be provided for another one or more of time / frequency / space.

[0209] In some examples, the information related to the IDC may include one or more of the maximum PPDU length, the maximum MCS (modulation coding scheme), whether low density parity check code (LDPC) is applied, whether high throughput (HT) immediate block ack is applied, a bitmap for disabled subchannels, the maximum MPDU (MAC protocol data unit) length, and / or the maximum A-MSDU (aggregate-MAC service data unit) length.

[0210] In some examples, a presence field may be included for each of one or more fields corresponding to information related to the IDC. For example, the presence field may include a bitmap, and bit positions in the bitmap may each correspond to fields corresponding to information related to the IDC.

[0211] In some examples, information related to an IDC may further include a field indicating full availability or partial availability (i.e., a field indicating whether full availability is present). Alternatively, information related to an IDC may further include a field indicating full unavailability or partial unavailability (i.e., a field indicating whether full unavailability is present). For example, if full availability or full unavailability is indicated, information related to an IDC may not include information about resources related to the IDC. Alternatively, if partial availability or partial unavailability is indicated, information related to an IDC may include information about resources related to the IDC.

[0212] In some examples, information related to IDC may further include a field indicating whether the time resource is periodic. For example, if periodicity of the time resource is indicated, information related to the IDC resource may include information on the number of time units and / or intervals. Alternatively, if aperiodicity of the time resource is indicated, information related to the IDC resource may not include information on the number of time units and / or intervals.

[0213] In step S1420, the first STA may transmit a first frame including the generated TWT element to one or more second STAs.

[0214] For example, the first frame may correspond to a broadcast / advertising / announced frame, such as a beacon frame, a probe response frame, or an association response frame.

[0215] For example, transmitting the first frame may include broadcasting or announcing the first frame.

[0216] Although not shown in FIG. 14, the first STA may perform IDC operations in an IDC service period (SP) based on information included in the TWT element.

[0217] In some examples, the IDC operation may include performing frame transmission and reception between a first STA and one or more second STAs during the IDC SP. Alternatively, the IDC operation may include deferring frame transmission and reception between the first STA and one or more second STAs during the IDC SP.

[0218] In the examples described above, the first STA may be an access point (AP) STA, and one or more second STAs may be one or more non-AP STAs. For example, one or more second STAs may be STA(s) belonging to the BSS of the first STA (or associated with the first STA).

[0219] The method described in the example of FIG. 14 may be performed by the first device (100) of FIG. 1. For example, one or more processors (102) of the first device (100) (or the first AP) of FIG. 1 may be configured to generate a TWT element and transmit a first frame including the generated TWT element to one or more second STAs via one or more transceivers (106). Furthermore, one or more memories (104) of the first device (100) may store commands for performing the method described in the example of FIG. 14 or the examples described below when executed by one or more processors (102).

[0220] For example, the memory (104) may store information related to various IDCs according to the present disclosure. The processor (102) may generate elements / frames for signaling information related to the IDC, generate various RUs, generate PPDUs, and transmit the generated PPDUs through the transceiver (106) based on the information stored in the memory (104). In addition, the processor (102) may generate transmission PPDUs and store information about the transmission PPDUs in the memory (104). For example, the processor (102) may be configured to perform operations of the first STA according to the examples of the present disclosure. For example, the processor (102) may be configured to determine an IDC situation, generate elements / frames / PPDUs including information related to the IDC, and transmit the elements / frames / PPDUs through the transceiver (106).

[0221] FIG. 15 is a diagram showing an example of the operation of a second STA according to the present disclosure.

[0222] In step S1510, the second STA can receive a first frame including a TWT element from the first STA.

[0223] In step S1520, the second STA can perform an IDC operation based on information included in the TWT element.

[0224] In the example of Fig. 15, the specific description of the field(s) included in the TWT element, the IDC-related information included in the TWT element, the first frame, and the IDC operation is the same as in the example of Fig. 14, so redundant description is omitted.

[0225] The method described in the example of FIG. 15 may be performed by the second device (200) of FIG. 1. For example, one or more processors (202) of the second device (200) of FIG. 1 (e.g., the second AP) may be configured to receive a first frame including a TWT element from a first STA via one or more transceivers (206) and perform an IDC operation based on information included in the TWT element. Furthermore, one or more memories (204) of the second device (200) may store commands for performing the method described in the example of FIG. 15 or the examples described below when executed by one or more processors (202).

[0226] For example, the memory (204) can store information related to various IDCs according to the present disclosure. The transceiver (206) can receive a PPDU based on the control of the processor (202). The PPDU received through the transceiver (206) can be stored in the memory (204). For example, the processor (202) can obtain control information for bandwidth / tone-plan / RU included in the PPDU (e.g., information included in the SIG field of the PPDU) and store the obtained control information in the memory (204). The processor (202) can perform decoding on the received PPDU. For example, the processor can perform an operation of restoring the results of cyclic shift delay (CSD), spatial mapping, inverse discrete Fourier transform (IDFT) / inverse fast Fourier transform (IFFT) operation, and guard interval (GI) insertion applied to the PPDU. In addition, the processor (202) can decode the data field of the PPDU received through the transceiver (206) and process the decoded data. For example, the processor (202) can transmit information about the decoded data field to a higher layer (e.g., a MAC layer). In addition, if the generation of a signal is instructed from the higher layer to the PHY layer in response to the data transmitted to the higher layer, a subsequent operation can be performed. For example, the processor can parse the MAC PDU obtained through PHY decoding of the DATA field of the PPDU received through the transceiver (206). In addition, the processor (202) can be configured to obtain information related to the IDC and perform an operation accordingly. For example, the processor (202) of the receiving device can be configured to perform the operation of the second STA according to an example of the present disclosure.For example, the processor (202) may be configured to receive a frame containing information related to the IDC and decode / parse a frame addressed to it based thereon.

[0227] In the examples of FIGS. 14 and 15, a first STA may transmit one or more PPDUs / frames including IDC-related information. The IDC-related information may include information indicating the start time of the IDC of the first STA, the duration of the IDC of the first STA, the channel and / or limited bandwidth of the first STA affected by the IDC of the first STA, the interval between each IDC period if the IDC of the first STA is periodic, information regarding how long the IDC of the first STA lasts if the IDC is periodic, and / or the presence of details of each IDC-related information. The corresponding PPDU / frame may include an ID indicating the IDC-related information. Information regarding the number of control information fields for including multiple control information may also be included. These PPDUs / frames may contain advertising and / or broadcasting frames of any format, such as beacon frames, probe response frames, (re)association response frames, etc., or may contain unicast frames of any format (e.g., action frames). Such IDC-related information may be included in a TWT element (e.g., broadcast TWT element) of an advertising / broadcasting frame, such as a beacon frame, and a broadcast TWT recommendation field may be used to indicate this. Such TWT elements may follow existing formats or may have new formats.

[0228] In the examples of FIGS. 14 and 15, the second STA may receive one or more PPDUs / frames containing IDC-related information from the first STA. For example, the second STA may perform detection on frames containing IDC-related information, and, through frame detection, determine whether the second STA will transmit and / or its transmission capabilities in the IDC section of the first STA.

[0229] The examples of FIGS. 14 and 15 may correspond to some of the various examples of the present disclosure. Below, various examples of the present disclosure, including the examples of FIGS. 14 and 15, are described in more detail.

[0230] In the embodiments described below, examples of the present disclosure are described assuming operations between two STAs, one IDC-supporting STA (e.g., a first STA) and a counterpart STA of Wi-Fi communication (e.g., a second STA), but the scope of the present disclosure is not limited thereto, and examples of the present disclosure can be equally applied to IDC operations and operations supporting the same between three or more STAs.

[0231] Example 1

[0232] This embodiment provides examples of basic procedures for IDC operation.

[0233] In general, IDC events can occur in smart devices such as smartphones, smartwatches, and AR / VR devices that can utilize both Wi-Fi and non-Wi-Fi technologies. Furthermore, IDC events can also occur in multi-link devices (MLDs) that support non-simultaneous transmit and receive (NSTR) operations. IDC events in these devices can also occur periodically, as in the example of FIG. 13. A device experiencing an IDC event (e.g., an STA) can notify other Wi-Fi devices (e.g., an AP) of the periodic IDC event. For this purpose, the aforementioned TWT procedure or another request / response procedure can be utilized.

[0234] FIG. 16 is a diagram illustrating examples of an IDC event notification signaling procedure according to the present disclosure.

[0235] For example, an AP can announce its IDC event to STA1 and STA2. In the example of Figure 16, IDC-related information can be included in an IDC broadcast TWT element or another element, and broadcast via a beacon frame or another frame. Accordingly, an AP can create an IDC TWT service period (SP) that can periodically notify its unavailability time.

[0236] When the AP detects that a periodic data exchange with another non-Wi-Fi device begins, it may announce the creation of an IDC TWT SP through a beacon and / or other form of frame containing broadcast TWT elements and / or other form of elements containing IDC information, including information such as IDC SP start time, duration, interval, persistent time (e.g., duration of a periodic IDC event), bandwidth (or information such as channel, resource unit (RU), multiple resource unit (MRU), distributed resource unit (DRU)), IDC indication (or IDC state), maximum number of spatial streams (max Rx Nss (number of spatial streams)), etc.

[0237] An AP can generate an IDC SP based on its own IDC information and transmit the information to STAs within the BSS via a broadcast frame such as a beacon. Alternatively, the AP can transmit IDC-related information only to specific STAs using an action frame such as a TWT setup frame and / or another form of unicast frame rather than a broadcast frame such as a beacon. For example, the AP can transmit / provide IDC-related information to STA(s) in a solicited manner in response to a request from an STA and / or in an unsolicited manner in which the AP provides the information without a request from the STA. This process is not limited to operations between APs and non-AP STAs, and can also be applied to operations between APs and APs, and between non-AP STAs and non-AP STAs.

[0238] Example 2

[0239] This embodiment describes a signaling scheme for IDC-related information. Below, examples of information / fields / subfields included in IDC-related information are described, as well as examples of elements / frames containing such IDC-related information.

[0240] Example 2-1

[0241] IDC related information may include one or more of the information described below.

[0242] IDC start time

[0243] IDC start time (ST) information may correspond to a value indicating the time interval from the current time to the time when the IDC SP starts, based on a predetermined unit (e.g., microseconds (ms), timing synchronization function (TSF), partial TSF, etc.).

[0244] IDC ST information can indicate when an IDC occurs, i.e. when unavailability occurs.

[0245] Unavailability may mean unavailability for the channel on which the STA operates or for some subchannels of the channel on which the STA operates (e.g., X 20MHz subchannels). That is, unavailability may not always mean unavailability for the channel on which the STA operates.

[0246] Alternatively, IDC ST information may indicate when availability occurs.

[0247] The IDC ST information can be indicated using the entire (e.g., the entire 8-octet-long information) or a portion (e.g., partial TSF) of the timestamp (or TSF) received from the AP or the AP itself. For example, in case of partial TSF, similar to the existing broadcast TWT, bit values ​​(or bit positions) starting from a specific bit value (or bit position) of the TSF up to X octets (e.g., 2 octets) can be used.

[0248] For example, an interval or duration (e.g., in microseconds) from the start or completion of transmission of a frame transmitting the current IDC ST information to the point at which IDC or unavailability occurs may be indicated as the IDC ST information.

[0249] Alternatively, the IDC ST may be indicated using the Duration field of the MAC header. For example, the value of the Duration field of the MAC header may be set to a value corresponding to the time interval or duration until the IDC ST. In this case, when the IDC ST is indicated through the Duration field of the MAC header, the start time information may be omitted from the IDC-related information (e.g., the IDC individual TWT parameter set).

[0250] IDC duration

[0251] IDC duration information can correspond to the duration of the IDC. For example, the duration unit can be microseconds, or another unit may be used. The size of the duration information can be defined as less than 8 octets (e.g., 2 octets), depending on the application to which the IDC SP is applied.

[0252] For example, information about a specific unit size may be included together with the duration information. For example, information indicating 1us, 8us, 32us, or 64us as the unit size may be included, and this may be applied as the unit of the value indicated by the duration information. For example, if the value of the duration information is 1000 and the unit size information indicates 1us, 1ms may be indicated as the duration of the IDC SP. For example, if the value of the duration information is 1000 and the unit size information indicates 8us, 8ms may be indicated as the duration of the IDC SP.

[0253] For example, IDC duration information may be defined as a 2-octet size, such as the duration field of the MAC header, but the size is exemplary and may be smaller or larger.

[0254] IDC interval

[0255] The IDC interval information may correspond to the time interval between repetitions of the IDC SP, when the IDC SP repeats periodically. For example, the interval unit may be microseconds, or another unit may be used. The size of the interval information may be defined as less than 3 octets (e.g., 2 octets), depending on the application to which the IDC SP is applied.

[0256] For example, information about a specific unit size may be included together with interval information. For example, information indicating 1 us, 8 us, 32 us, or 64 us as the unit size may be included, and this may be applied as a unit of the value indicated by the interval information. For example, if the value of the interval information is 1000 and the unit size information indicates 1 us, 1 ms may be indicated as the interval between repeated IDC SPs. For example, if the value of the interval information is 1000 and the unit size information indicates 8 us, 8 ms may be indicated as the interval between repeated IDC SPs.

[0257] For example, IDC interval information may be defined as a 2-octet size, such as the duration field of the MAC header, but the size is exemplary and may be smaller or larger.

[0258] IDC continuity

[0259] IDC continuity information can indicate how long an IDC SP continues. For example, the number of IDC SP repetitions (e.g., an integer value) can be indicated as IDC continuity information.

[0260] Additionally or alternatively, as IDC continuity information, the entire duration including all IDC SP repetitions from the start time of the IDC SP (i.e., the duration until the end of the IDC SP repetitions, not the duration of one IDC SP) or the end time of the IDC SP repetitions (i.e., the point in time when the IDC SP repetitions end, not the end time of one IDC SP) may be indicated.

[0261] Alternatively, the number of beacon frames, TBTT, beacon interval, etc. may be indicated as IDC continuity information. For example, the number of times a beacon is transmitted within a period in which repetition continues from the time when the IDC SP is first generated / started may be indicated. Alternatively, the number of beacon intervals for which repetition of the IDC SP continues in units of beacon intervals from the time when the IDC SP is first generated / started may be indicated.

[0262] This IDC continuity information may be included in the IDC information when an IDC interval exists (i.e., when a predetermined interval exists between repetitions of the IDC SP).

[0263] IDC channel / BW(bandwidth)

[0264] IDC channel / BW (bandwidth) information can indicate a channel / BW in which IDC occurs or does not occur. In other words, the channel / BW information can indicate a frequency resource in which an IDC SP occurs or does not occur.

[0265] For example, IDC channel / BW information can be defined in bitmap format. For example, for the operating channel and / or bandwidth of an STA, a bitmap in units of 20MHz (sub)channels can be defined, and whether each 20MHz (sub)channel is available or unavailable due to an IDC event can be indicated through the value of each bit position in the bitmap.

[0266] Additionally or alternatively, since the BW of each STA may be different, BW information may be additionally indicated. For example, the BW may be indicated as one of 20MHz / 40MHz / 80MHz / 160MHz / 320MHz, and a bitmap having a number of bits corresponding to the number of 20MHz (sub)channels corresponding to the indicated BW may be adaptively configured.

[0267] IDC channel / BW information may indicate a limited BW within which an STA can transmit and receive (i.e., available) due to an IDC situation, in which case information about the IDC channel may not be included in the IDC-related information.

[0268] The BW information may be set to a value indicating available or unavailable bandwidth due to an IDC event or an IDC condition. For example, the available / unavailable bandwidth may be indicated by the start frequency and end frequency of the BW, or by the center frequency and frequency bandwidth (i.e., size) of the BW. Alternatively, the available / unavailable bandwidth may be indicated via the RU allocation subfield. For example, in an IDC situation, a frequency band used for non-Wi-Fi communication may be converted into a resource unit (RU) allocation based on the Wi-Fi operating bandwidth. The RU allocation subfield may indicate a specific combination among predetermined combinations regarding which size RU (e.g., 26-tone RU, 52-tone RU, 106-tone RU, 242-tone RU, 996-tone RU)(s) is allocated to which frequency position (or RU index)(s). Accordingly, frequency unit(s) of a certain size at a certain frequency location(s) can be indicated as available / unavailable bandwidth due to IDC operation.

[0269] BW type information (e.g., 2-bit size) within BW information can be defined as shown in the table below. Some or all of the types in the example can be defined, and other type(s) can be added.

[0270] Value Meaning 0 Frequency range 1 Center frequency 2 Resource unit 3 Reserved

[0271] If the value of the BW type is 0, it can indicate that the second subfield within the BW subfield corresponds to the start frequency and the third subfield corresponds to the end frequency. For example, if the value of the start frequency is 2400, it can be indicated as approximately 2.4 GHz (= 2400 * 106 Hz), and if the value of the end frequency is 2483, it can be indicated as approximately 2.48 GHz (= 2483 * 106 Hz).

[0272] If the value of the BW type is 1, it can indicate that the second subfield within the BW subfield corresponds to the center frequency and the third subfield corresponds to the frequency bandwidth. For example, if the value of the center frequency is 7987, it can be indicated as approximately 7.9 GHz (= 7987 * 10 6 Hz), and if the value of the frequency bandwidth is 500, it can be indicated as approximately 0.5 GHz (= 500 * 10 6 Hz).

[0273] If the value of the BW type is 2, it can indicate that the second subfield within the BW subfield corresponds to BW and the third subfield corresponds to the RU allocation subfield. For example, if the value of the second subfield BW is 0, it can indicate 20MHz, if the value is 1, it can indicate 40MHz, if the value is 2, it can indicate 80+80MHz or 160MHz, if the value is 3, it can indicate the first 320MHz (i.e., the 320MHz bandwidth of the lower frequency), if the value is 4, it can indicate the second 320MHz (i.e., the 320MHz bandwidth of the higher frequency), and the remaining values ​​can be defined as reserved. Accordingly, the value of the third subfield, the RU allocation subfield, can indicate one of the combinations of RU sizes and positions (or indices) that are predetermined for each BW.

[0274] If the TWT channel field among the TWT parameters indicates an available channel or an unavailable channel for the IDC, the BW subfield within the IDC information field may be omitted.

[0275] IDC NSS (number of spatial streams) / antenna

[0276] IDC NSS (number of spatial stream) / antenna information may include information indicating available (or unavailable) NSS and / or available (or unavailable) antenna index.

[0277] For example, available NSS information may indicate the number of available spatial streams. Depending on the value of available NSS information, the number of available spatial streams may be indicated even in an IDC situation, excluding spatial streams that are unavailable due to an IDC event or IDC situation.

[0278] For example, the available NSS information may indicate the NSS and / or antenna indexes that are available or unavailable in an IDC situation. For example, the availability / unavailability of each antenna may be indicated bit by bit, starting from the lowest (or highest) antenna index, based on the most significant bit (MSB) or least significant bit (LSB) of the information.

[0279] max PPDU duration

[0280] The maximum PPDU duration information can indicate the total length of the PPDU, such as the L_LEGNTH parameter of L-SIG, the aPPDUMaxTime parameter, etc. In order to adjust the value of the maximum PPDU duration between STAs (AP to AP, AP to non-AP STA, non-AP STA to non-AP STA) considering the frequency of occurrence of unavailability periods caused by IDC, the maximum PPDU duration information can be included in the IDC operation parameter to match the value between STAs. Additionally or alternatively, the value of the maximum PPDU duration can be adjusted and indicated considering the length and interval of data transmission of actual non-Wi-Fi wireless technology within the unavailability period caused by IDC. The maximum PPDU duration information can be defined as a size of 2 octets, or as a size in an appropriate range according to the duration value range.

[0281] Maximum modulation coding scheme (MCS)

[0282] The maximum MCS information refers to the maximum modulation and coding technique, which can affect the maximum data rate. When transmission and reception are possible with an appropriate or lower MCS during unavailability periods due to IDC conditions, the maximum MCS information is included in the IDC operation parameters to adjust the maximum MCS value between STAs (AP to AP, AP to non-AP STA, non-AP STA to non-AP STA). This allows the values ​​to be consistent between STAs. The maximum MCS information can be defined as a 4-bit size, or as an appropriate range of sizes based on the MCS value range.

[0283] Use of LDPC

[0284] LDPC is a coding scheme designed to improve the reliability and efficiency of data transmission. While LDPC can offer improvements such as error correction, it can also require greater complexity, longer latency, and more resources. LDPC usage information can be included in the IDC operation parameters to enable LDPC when LDPC is disabled during unavailability periods due to IDC conditions. LDPC usage information can be defined as a 1-bit size, simply indicating whether LDPC is being used, or it can be defined as a larger size, indicating various LDPC modes.

[0285] Use of HT-immediate Block ACK (user of HT-immediate BlockAck)

[0286] When Immediate Block ACK is used, the STA must send an ACK response after SIFS immediately after receiving data. Considering the case where the ACK cannot be sent immediately due to an IDC situation, in order to coordinate the application of Immediate Block ACK between STAs (AP to AP, AP to non-AP STA, non-AP STA to non-AP STA) regarding the use of Immediate Block ACK, the IDC operation parameter may include information on the use of HT-Immediate Block ACK so that the value can be matched between STAs. The HT-Immediate Block ACK use information may be defined as 1 bit in size to simply indicate whether to use it, or may be defined as larger in size to indicate various types of Immediate ACK.

[0287] disabled subchannel bitmap

[0288] Information on subchannels disabled due to IDC situations may be included in the IDC operation parameters. By utilizing the disabled subchannel bitmap information, data transmission may be performed using available subchannels between STAs (AP to AP, AP to non-AP STA, non-AP STA to non-AP STA) during unavailability periods due to IDC situations. The disabled subchannel bitmap information may be defined as 8 bits in size, or may be defined as an appropriate range of sizes depending on the range of the number of subchannels.

[0289] maximum MPDU length

[0290] In order to adjust the value of the maximum MPDU length between STAs (AP to AP, AP to non-AP STA, non-AP STA to non-AP STA) considering the frequency of occurrence of unavailability periods caused by IDC, the maximum MPDU length information may be included in the IDC operation parameters to make the value consistent between STAs. Alternatively, the value of the maximum MPDU length may be adjusted and indicated considering the length and interval of data transmission of actual non-Wi-Fi wireless technologies within the unavailability periods caused by IDC. The maximum MPDU length information may be defined as a size of 2 octets, or as a size within an appropriate range according to the range of MPDU lengths.

[0291] maximum A-MSDU length

[0292] In order to adjust the value of the maximum A-MSDU length between STAs (AP to AP, AP to non-AP STA, non-AP STA to non-AP STA) considering the frequency of occurrence of unavailability periods caused by IDC, the maximum A-MSDU length information may be included in the IDC operation parameters to match the value between STAs. Alternatively, the value of the maximum A-MSDU length may be adjusted and indicated considering the length and interval of data transmission of actual non-Wi-Fi wireless technologies within the unavailability periods caused by IDC. The maximum A-MSDU length information may be defined as a size of 1 octet, or as a size in an appropriate range according to the range of the A-MSDU length.

[0293] Example 2-2

[0294] The information / fields / subfields of the various examples described above may vary depending on the situation in which they are included in the IDC-related information. For example, if the primary channel of the BSS to which the STA belongs is affected by an IDC event, the STA may not be able to use all channels within the BSS due to the IDC operation, and therefore the IDC channel / BW information indicating specific frequency resources may not be included in the IDC-related information. Alternatively, if the entire spatial stream or the entire operating channel of the STA is affected and cannot be used due to the IDC operation, the IDC channel / BW information and available NSS information may not be included in the IDC-related information. Alternatively, if the IDC SP does not repeat periodically but occurs only temporarily once, the IDC interval information and IDC continuity information may not be included in the IDC-related information. Therefore, various methods described below may be applied to indicate whether specific information / fields / subfields are included (or exist) in the IDC-related information.

[0295] Figure 17 illustrates additional examples of IDC information fields according to the present disclosure.

[0296] For example, a presence field can be defined and used for each piece of information / field / subfield. If the value of the presence field for a specific piece of information is 1, the specific piece of information exists, and if the value is 0, the specific piece of information may not exist.

[0297] The presence field may also be defined in bitmap form. As in the example of Fig. 17(a), it can be assumed that the first bit of the presence bitmap corresponds to IDC start time information, the second bit corresponds to IDC duration information, and the third bit corresponds to IDC channel information. If the presence bitmap is set to 110xxxxx, the IDC information may include the IDC start time field and the IDC duration field, but may not include the IDC channel field. The remaining bits except for the number of bits corresponding to each piece of information in the presence bitmap may be reserved.

[0298] Next, the 1-bit fully unavailability field in the examples of FIG. 17 may also indicate whether other information is included. As described above, if full unavailability is indicated (e.g., if the value of the fully unavailability field is set to 1), other fields such as the IDC channel may not be included in the IDC-related information. Alternatively, if partial unavailability (or partial availability) is indicated (e.g., if the value of the fully unavailability field is set to 0), other fields such as the IDC channel may be included in the IDC-related information.

[0299] Depending on the information contained in the IDC-related information, the IDC SP may be available during the IDC SP duration, and the outside of the IDC SP may correspond to unavailable times.

[0300] Next, a 1-bit indication field may be defined and utilized to indicate periodicity. If the IDC SP is periodic and continuously repeats, the value of the periodicity field may be set to 1. If the IDC SP is generated only once, the value of the periodicity field may be set to 0. In this case, IDC interval information and IDC continuity information may not be included in the IDC-related information.

[0301] In the example of Fig. 17(b), if the value of the entire unavailable field is 0, it means that some of the data is unavailable (or partially available), and thus information such as IDC channels may be included. In addition, if the value of the periodicity field is 0, it means that the data corresponds to a non-repeating IDC SP, and thus the IDC start time and IDC duration fields are included, but the IDC interval and IDC continuity fields may not be included.

[0302] In the example of Fig. 17(c), a length field may be added to the IDC information field. When a new subfield is added to the IDC information, an STA that cannot recognize the new subfield may determine which field to ignore based on the value of the length field.

[0303] Additionally or alternatively, an IDC information field may be assigned an ID. This is to explicitly indicate that the field is an IDC information field, and any other ID value may be recognized by the STA as not being an IDC information field.

[0304] As shown in the example of Fig. 17(d), a generalized control information field may include one or more control information. For example, a generalized control information field may include the same control information or different control information. For example, an IDC information field and another information field may be included within a general control information field. The first field of the general control information field may indicate the number of control information, and for example, it may be assumed that two pieces of control information are included. It is assumed that an ID value of 0 is assigned to an IDC information field, and an ID value of 1 is assigned to a BSR (buffer status report) information field. Therefore, an IDC information field including an ID field set to a value of 0 and a BSR information field including an ID field set to a value of 1 may be included within a general control information field.

[0305] Alternatively, the number field of control information may be omitted in the example of Fig. 17(d). Alternatively, the number field of control information may be configured in the form of an element that includes a length field.

[0306] In Fig. 17(e), examples of the aforementioned IDC information fields are shown in which the aforementioned IDC information fields are included in an aggregated-control (A-control) field within the HT (high throughput) control field of the MAC header. The A-control field may be included in a QoS data frame, a QoS null frame, a management frame, etc. The A-control field may include various control information and may be distinguished through a control ID assigned to each of the various control information. Assuming that a control ID is assigned to the IDC information, various IDC-related information described above may be included following this control ID field. Subsequently, other control information (if any) may be included within the A-control field. After the various control information within the A-control field is included, padding bits may be added if necessary to match a specific length.

[0307] Example 2-3

[0308] IDC-related information, including one or more of the information described in the examples above, can be announced to multiple STA(s) via existing TWT elements, new TWT elements, or other elements. For example, an element containing IDC-related information can be included in a beacon frame and broadcast / advertised to multiple STA(s). Various examples defining specific elements containing IDC-related information are described below.

[0309] For example, an IDC TWT element can be defined by reusing / modifying / modifying / extending an existing broadcast TWT element (e.g., a TWT element including a broadcast TWT parameter set of FIG. 12). In this case, a broadcast TWT recommendation field within the request type field of the broadcast TWT parameter set field can be newly defined.

[0310] FIG. 18 illustrates examples of TWT control fields according to the present disclosure.

[0311] In the control field format of the IDC TWT element that reuses the existing TWT element in the example of Fig. 18(a), the value of the agreement type field may be set to a value indicating broadcast (e.g., 2) in order to reuse the broadcast TWT element. In the control field format of the TWT element (see Fig. 10), the remaining fields may be reserved, and the agreement type field (e.g., set to a value of 2) and the wake duration unit field may be included.

[0312] In the example of Fig. 18(b), the control field format of the IDC TWT element may include an NDP paging indicator / unavailability mode field, a responder PM mode field, a negotiation type field, a TWT information frame disable field, a wake duration unit field, a link ID bitmap present field, and an aligned TWT field. Here, the value of the negotiation type field may be set to a value indicating broadcast (e.g., 2). In the example of Fig. 18(b), some field(s) may be reserved.

[0313] Additionally, to reuse the Broadcast TWT Parameter Set field, the value of the Broadcast TWT Recommendation field within the Request Type field may be set to 5. Setting the value of the Broadcast TWT Recommendation field to 5 may be restricted to only when the value of the Agreement Type field within the TWT Control field is set to 2.

[0314] Referring back to the example of FIG. 12, the broadcast TWT parameter set field format may or may not include an (optionally) 3-octet restricted TWT traffic info field following the 2-octet broadcast TWT info field. In the request type field format of the broadcast TWT parameter set field, B15 may also be defined as an aligned field. In the range of values ​​of the broadcast TWT recommendation field within the request type field of this broadcast TWT parameter set field (e.g., 0 to 7), one of the existing reserved / undefined values ​​(e.g., 5 to 7) may be newly defined to have a specific meaning (e.g., 5). For example, a value of 5 in the Broadcast TWT Recommendation field can be defined to mean that when transmitted in a broadcast TWT element, the corresponding broadcast TWT SP is referred to as an IDC SP, and during an IDC SP, IDC-scheduled STA(s) do not perform any data exchanges with the IDC-announced AP to avoid IDC data transmission collision.

[0315] Alternatively, IDC SP may refer to a period of unavailability during which IDC-scheduled STA(s) exchange data only within the IDC SP and not outside the IDC SP. For example, a value of 5 in the Broadcast TWT Recommendation field may be defined to mean that when transmitted in a broadcast TWT element, the corresponding broadcast TWT SP is referred to as an IDC SP, only during an IDC SP, IDC-scheduled STAs perform data exchanges with the IDC-announced AP to avoid in-device coexistence data transmission collision, and outside from the IDC SP shall be unavailable for data exchanges.

[0316] As another example, apart from conveying IDC-related information through the broadcast TWT recommendation field value, the SP internal interval can be defined as an active interval (i.e., an available period) and the SP external interval can be defined as an unavailable interval by setting the value of a specific field / bit within the broadcast TWT element to a specific value. In order to define and indicate such IDC-related information, the broadcast TWT recommendation field can be set to a specific value as described above, or other fields / bits (e.g., a specific bit of the control field (e.g., a bit at position B7)) can be set to a specific value.

[0317] In this case, the broadcast TWT ID of the broadcast TWT information field may be set to a value of 0, the responder PM mode field of the control field may be set to a value of 0, and / or the NDP paging indicator / unavailability mode field may be set to a value of 0 or 1. Accordingly, the SP interval specified (or scheduled) by the broadcast TWT element may be defined as an available interval, and an interval other than the specified (or scheduled) SP interval may be defined as an unavailable interval due to IDC.

[0318] As mentioned above, the creation / configuration of SPs may also be applied when APs periodically perform power saving, such as power saving of the scheduling AP.

[0319] Figure 19 illustrates examples of request type fields according to the present disclosure.

[0320] For example, the request type field in the broadcast TWT parameter set may be modified / redefined and used as in the example of Fig. 19(a) to indicate whether the IDC broadcast TWT is full or partial, and to define setup commands such as announce, update, suspend, and teardown for the IDC broadcast TWT. Alternatively, some fields of Fig. 19(a) (trigger field, flow type field, and aligned field) may be reserved as in the example of Fig. 19(b).

[0321] A value of 1 in the Total Unavailability field may indicate a time period of unavailability provided by the IDC-related information, or that the entire IDC SP is completely unavailable. In the case of total unavailability, information other than time domain information (e.g., start time, duration, interval, etc.) may not be included (or may be omitted) in the IDC-related information.

[0322] If the value of the overall unavailability field is 0, it may mean that the unavailable time interval or the entire IDC SP is partially unavailable (i.e., partially available). For example, the unavailable time interval and / or the partial unavailability of some of the IDC SPs may mean that transmission / reception is possible by adjusting alternative available channels, alternative spatial streams, Tx / Rx parameters, etc. For each interval, an initial control frame (e.g., an RTS frame) may be transmitted to check whether the interval is available, and if available, data transmission / reception may be performed in the interval.

[0323] Alternatively, the Full Unavailability field can be defined by another name, such as the Partial Unavailability field. A value of 0 for the Partial Unavailability field may indicate that the unavailability time interval specified by the IDC-related information and / or the entire IDC SP is completely unavailable. A value of 1 for the Partial Unavailability field may indicate that the unavailability time interval specified by the IDC-related information and / or some of the entire IDC SP are partially unavailable.

[0324] In the examples described above, an IDC SP specified through IDC-related information may be defined as available within the time interval and unavailable outside of the time interval, or may be defined as unavailable within the time interval and available outside of the time interval.

[0325] IDC setup command fields may be defined as shown in the table below.

[0326] Value Meaning 0 Request 1 Update 2 Suspend 3 Teardown 4-7 Reserved

[0327] For example, if the value of the IDC setup command field is set to 0, indicating a request, it may correspond to a command to announce an IDC broadcast TWT. If the value is 1, it may correspond to a command to update an existing IDC SP. If the value is 2, it may correspond to a command to suspend an existing IDC SP. If the value is 3, it may correspond to a command to teardown an existing SP.

[0328] FIG. 20 illustrates examples of broadcast TWT parameter set fields according to the present disclosure.

[0329] As in the example of Fig. 20(a), new IDC-related information can be added to the broadcast TWT parameter set field.

[0330] As in the example of Fig. 20(b), the broadcast TWT parameter set field for IDC may not require limited TWT traffic information, so the field may be omitted and new IDC-related information may be added.

[0331] As in the example of Fig. 20(c), the broadcast TWT parameter set field for IDC may not require broadcast TWT information and limited TWT traffic information, so those fields may be omitted and new IDC-related information may be added.

[0332] In the examples described above, if the time domain information included in the broadcast TWT parameter set field for the IDC (e.g., target wake time field, nominal minimum TWT wake duration field, etc.) is used as time domain information for the IDC SP, the time domain information may be omitted in the IDC-related information field.

[0333] FIG. 21 is a diagram showing examples of IDC-related information fields according to the present disclosure.

[0334] The IDC-related information fields included in the broadcast TWT parameter set may include an ID field, a persistence field, an IDC channel field, a maximum Nss field, a Tx / Rx only field, and a Tx / Rx parameter field, as shown in the example of Fig. 21(a). The persistence field may be defined as being 1-octet (or 8-bit) in size, for example.

[0335] As in the example of Fig. 21(b), the IDC related information field may be defined as a 2-octet size, the same size as the broadcast TWT information field in the existing broadcast TWT parameter set field, in order to support legacy STA.

[0336] IDC type fields can be defined as shown in the table below.

[0337] Value Meaning 0 ID and Duration 1 IDC Channel 1 (up to 160MHz) 2 IDC Channel 2 (up to 320MHz) 3 Max Nss and Tx / Rx Only 4 Tx / Rx Parameters 5-7 Reserved

[0338] IDC types can be defined separately, or can be composed of a combination of parameters allowed for size, as shown in the table above. The ID field is defined as a value that identifies the IDC SP, and the persistence field can define time information regarding how long the IDC SP will operate. If the value of the IDC type field is 0, the IDC information field of Figure 21(b) can be composed of the ID field and the persistence field.

[0339] When the IDC-related information field is defined as above, the TWT parameter information field of the TWT element (see Fig. 10) may include multiple broadcast parameter set fields, and each broadcast parameter set field may include IDC-related information for a different ID.

[0340] For example, if the value of the IDC type field is 1, available or unavailable channels can be indicated in bitmap form in units of 20 MHz. In this case, since the IDC type value 1 can cover a bandwidth of up to 160 MHz, the last bit of the IDC-related information field can be set to continue in order to cover a bandwidth of up to 320 MHz. If the continue bit, which is the last bit of the IDC-related information in a broadcast parameter set field, is indicated as 1, the value of the last broadcast parameter set field of the request type field in the corresponding broadcast parameter set field is set to 0, and the IDC type can be indicated as 2 in the IDC-related information of the subsequent broadcast parameter set field. Accordingly, the remaining channel bitmaps can be indicated continuously in the previous IDC-related information field. For example, 12 bits may be utilized for an IDC-related information field corresponding to an IDC type value 1 in a first broadcast parameter set field, and 4 bits may be utilized for an IDC-related information field corresponding to an IDC type value 2 in a second broadcast parameter set field following the broadcast parameter set field.

[0341] Example 2-4

[0342] The IDC broadcast TWT element including the aforementioned IDC-related information is included in a beacon frame and transmitted to STAs, as shown in the example of FIG. 16, so that the AP's IDC event can be notified to the STAs. STA1 and STA2 receiving this can check the AP's periodic IDC SP based on the IDC-related information. If the IDC SP is completely unavailable, STA1 and STA2 may not attempt to exchange data during that period. If the IDC SP is partially unavailable, STA1 and / or STA2 may perform data exchange through other resources (e.g., other channels, other spatial streams, etc.). Additionally or alternatively, when the IDC SP occurs frequently and for a long time, it may be possible to utilize the information to perform actions such as permanently switching to another channel.

[0343] FIG. 22 is a diagram illustrating an example of an IDC event update notification operation according to the present disclosure.

[0344] In the example of FIG. 22, the IDC setup command field included in the IDC broadcast TWT element initially transmitted by the AP scheduled for IDC operation (e.g., in the request type field of FIG. 19) may be set to a value corresponding to the request (e.g., 0), thereby allowing the AP to announce IDC-related information for the periodic IDC SP. Thereafter, when the IDC situation changes, the AP may set the IDC setup command field to a value corresponding to update (e.g., 1) and include the new / changed IDC-related information in the IDC broadcast TWT element to notify the STA(s).

[0345] Although not shown in Figure 22, if the IDC setup command field included in the IDC broadcast TWT element (subsequently) transmitted by the AP is set to a value corresponding to suspend or teardown, the IDC SP may be temporarily suspended, or the IDC SP may be torn down and terminated.

[0346] Defining IDC broadcast TWT elements in this way allows them to be extended to support IDC SPs while reusing existing broadcast TWT-related behavior. Therefore, new IDC events can be supported without affecting legacy STAs.

[0347] Example 2-5

[0348] The examples described above describe IDC broadcast TWT elements that reuse existing TWT elements. This embodiment describes an example of defining a new element that supports IDC operations. The new element can be transmitted to STA(s) by being included in a notification frame, such as a beacon frame, and / or an advertisement frame.

[0349] A new TWT element for IDC purposes can be defined that is distinct from the existing TWT elements. In contrast to the existing TWT element, where the element ID is defined as 216 (in which case the element ID extension is not applicable), a new TWT element (e.g., the element name is IDC TWT) can be defined with the element ID as 255 and the element ID extension as, for example, 117. In other words, the new TWT element can be defined as extensible and non-fragmentable. The value of the element ID extension of the IDC TWT element is not limited to 117, and any value from the existing reserved values ​​can be applied.

[0350] FIG. 23 illustrates an exemplary format of an IDC TWT element according to the present disclosure.

[0351] An IDC TWT element may include an element ID field, a length field, an element ID extension field, a control field, and a TWT parameter information field.

[0352] The control fields of an IDC TWT element may include a start time presence field, a duration presence field, an interval presence field, an IDC continuity presence field, a BW presence field, and / or an available NSS presence field. Some or all of the exemplary fields within the control field may be included.

[0353] The TWT parameter information field of an IDC TWT element may include one or more IDC TWT parameter set fields. An IDC TWT parameter set field may include IDC-related information. For example, fields indicated to exist based on a bitmap of presence fields of a control field may be included in the IDC TWT parameter set field as IDC-related information.

[0354] Specifically, the start time presence field within the control field may indicate whether a start time field exists in the IDC TWT parameter set. The duration presence field may indicate whether a duration field exists in the IDC TWT parameter set. The interval presence field may indicate whether an interval field exists in the IDC TWT parameter set. The IDC continuity presence field may indicate whether an IDC continuity field exists in the IDC TWT parameter set. The BW presence field may indicate whether a BW field exists in the IDC TWT parameter set. The available NSS presence field may indicate whether a maximum number of NSS fields exists in the IDC TWT parameter set. The field(s) indicated as present by each presence field may be included in the IDC-related information field within the IDC TWT parameter set field.

[0355] The request type field of the IDC TWT parameter set field may include an IDC type field, a full unavailability field, an IDC setup command field, and / or an IDC flow identifier field.

[0356] IDC type fields can be defined as shown in the table below.

[0357] Value Meaning 0 Individual IDC 1 Broadcast IDC 2 Reserved 3 Reserved

[0358] The IDC type field may be set to a value corresponding to a broadcast IDC (e.g., 1). For example, in the examples of the present disclosure, when an IDC TWT element is transmitted through a management frame such as a beacon frame, a probe response frame, a (re)association response frame, or an action frame such as a TWT setup frame, the IDC type field of the request type field of the IDC TWT parameter set field of the corresponding IDC TWT element may be set to a value indicating a broadcast IDC.

[0359] A value of 1 in the Total Unavailability field may indicate that the IDC SP is completely unavailable, or it may indicate a time interval of unavailability or the entire IDC service period provided by the IDC-related information. In the case of total unavailability, information other than time domain information (e.g., start time, duration, interval, etc.) may be omitted.

[0360] A value of 0 in the Total Unavailability field may indicate partial unavailability of an unavailable time period or the entire IDC SP. In this case, since some of the IDC SPs are unavailable, an initial control frame or similar is sent for each corresponding interval to determine if the corresponding interval is available. If available, data frame transmission / reception can be performed in the corresponding interval.

[0361] Alternatively, the Full Unavailability field can be defined by another name, such as the Partial Unavailability field. A value of 0 for the Partial Unavailability field may indicate that the unavailability time interval provided by the IDC-related information and / or the entire IDC SP is completely unavailable. A value of 1 for the Partial Unavailability field may indicate that the unavailability time interval and / or some of the IDC SPs are partially unavailable.

[0362] In the examples described above, an IDC SP specified through IDC-related information may be defined as available within the time interval and unavailable outside of the time interval, or may be defined as unavailable within the time interval and available outside of the time interval.

[0363] The IDC setup command field can be defined as described with reference to Table 2 above.

[0364] The IDC flow identifier can indicate the ID of an IDC service provider (SP). Each command specified in the IDC setup command can be applied and managed for the IDC service provider (SP) corresponding to the IDC flow identifier.

[0365] As described above, redefining the IDC (broadcast) TWT element allows for flexible and efficient inclusion of IDC-related information within the element or within the frame containing the element. Specifically, by reusing existing TWT elements, fields / parameters / information unrelated to IDC operation can be excluded, and the element can be composed only of fields / parameters / information related to IDC operation, thereby supporting more efficient signaling.

[0366] An IDC (broadcast) TWT element containing such IDC-related information may be notified to STAs via a beacon frame, as illustrated in FIG. 16. Additionally, an IDC (broadcast) TWT element containing updated IDC-related information may be notified to STAs via a beacon frame, as illustrated in the example of FIG. 22.

[0367] Additionally or alternatively, the IDC (broadcast) TWT element may be included in management frames, such as (re)association response frames, probe response frames. Management frames may be selected as transmittable / receivable based on when the periodic IDC event occurs, and the selected management frames may include the IDC (broadcast) TWT element, or all frames may include the IDC (broadcast) TWT element.

[0368] For example, suppose that STA1, which is not yet associated with an AP, receives a beacon transmitted from the AP and sends a probe request to the AP, and a periodic IDC event occurs at the AP. In this case, the AP can include an IDC TWT element in the probe response and transmit it to STA1.

[0369] As another example, suppose that STA1, which is not yet associated with an AP, receives a beacon transmitted from the AP, sends a probe request to the AP, and then receives a probe response from the AP. At the time that STA1 sends the association request to the AP, a periodic IDC event occurs at the AP. In this case, the AP may include an IDC TWT element in the (re)association response and transmit it.

[0370] In this way, an STA that receives an IDC TWT element through a probe response or (re)association response can identify the AP's periodic IDC SP through the IDC-related information contained in the IDC TWT element. Accordingly, if the IDC SP is completely unavailable, data exchange may not be attempted during the corresponding period, or if the IDC SP is partially unavailable, data exchange may be performed on other resources (e.g., other channels, other spatial streams, etc.).

[0371] If IDC SPs occur frequently and for a long time, it may be possible to use IDC-related information to perform actions such as permanently switching to another channel.

[0372] In the examples of FIG. 16 and / or FIG. 22, IDC-related information may be provided to specific STAs via the TWT setup frame, rather than via the beacon frame / probe response frame / (re)association response frame. For example, in cases where there are only a few or only one non-AP STA associated with a mobile AP, the AP may use an action frame, such as the TWT setup frame, or other unicast frames, to convey IDC-related information to specific STAs.

[0373] FIG. 24 is a diagram illustrating an additional example of an IDC event notification signaling procedure according to the present disclosure.

[0374] Unlike the example of Fig. 16, the example of Fig. 24 shows an example in which the IDC SP generated / set based on the IDC-related information included in the IDC (broadcast) TWT element corresponds to an available interval, and intervals other than the IDC SP are applied as unavailable intervals. In this way, the example in which the IDC SP is an available time and the interval is an unavailable time can be applied as an example that replaces the available time and unavailable time in the examples in which the IDC SP is an unavailable time and the interval is an available time described above.

[0375] In the existing wireless LAN system, there is no method to support IDC operation, and by setting the IDC SP to an unavailable time (or available time) based on the IDC-related information according to the present disclosure, a new effect can be achieved in which non-Wi-Fi transmission and reception and Wi-Fi transmission and reception are efficiently performed without interference.

[0376] 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.

[0377] 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.

[0378] 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.

[0379] The method proposed in this disclosure has been described with a focus on examples applied to IEEE 802.11-based systems, but can be applied to various wireless LANs or wireless communication systems in addition to IEEE 802.11-based systems.

Claims

A step of generating a target wake time (TWT) element by a first station (STA); and A step of transmitting a first frame including the TWT element to one or more second STAs by the first STA, The above TWT element includes a request type field, The above request type field includes a broadcast TWT recommendation field, A method wherein the above broadcast TWT recommendation field indicates that the TWT element contains information related to in-device coexistence (IDC). In the first paragraph, A method in which information related to the above IDC includes information on one or more of time resources, frequency resources, or spatial resources. In the second paragraph, A method wherein the information about the time resource includes one or more of a start time, a duration, an interval, a continuity, an end time, or a number of time units. In the second paragraph, A method wherein the information about the frequency resource includes one or more of a bandwidth, a frequency range, a center frequency, a channel, or a resource unit. In the second paragraph, A method wherein the information about the above spatial resource includes at least one of an antenna index, a number of antennas, a spatial stream index, or a number of spatial streams. In the first paragraph, A method in which information related to the above IDC includes at least one of a maximum physical layer protocol data unit (PPDU) length, a maximum modulation coding scheme (MCS), whether a low density parity check code (LDPC) is applied, whether a high throughput (HT) immediate block ACK (ACK) is applied, a bitmap for a disabled subchannel, a maximum medium access control (MAC) protocol data unit (MPDU) length, or a maximum aggregate-MAC service data unit (A-MSDU) length. In the first paragraph, The above TWT element includes a control field, The above control field includes a negotiation type field, A method in which the above agreement type field is set to a value corresponding to broadcast. In paragraph 7, The value corresponding to the above broadcast is 2, method. In the first paragraph, A method wherein the above broadcast TWT recommendation field is set to one of a value of 5 to 7. In the first paragraph, The above request type field is included in the broadcast TWT parameter set field of the TWT element. In the first paragraph, Information related to the above IDC: a presence field for each of one or more fields corresponding to information related to the IDC; or A field indicating full or partial availability, or a field indicating full or partial unavailability. A method comprising one or more of the following: In paragraph 11, The above existence field contains a bitmap, A method in which the bit positions of the above bitmap each correspond to fields corresponding to information related to the IDC. In paragraph 11, Based on the indication of the above total availability or the above total unavailability, the information related to the IDC does not include information about resources related to the IDC, A method wherein, based on the indication of some availability or some unavailability, the information related to the IDC includes information about resources related to the IDC. In the second paragraph, A method wherein the information related to the IDC further includes a field regarding the periodicity of the time resource. In paragraph 14, Based on the periodicity of the above time resource being indicated, information about the resource related to the IDC includes information about one or more of the number of time units or the interval, A method in which information about resources related to the IDC does not include information about the number of time units or the interval, based on the indication of aperiodicity of the time resource. In the first paragraph, Based on the information related to the above IDC, during the IDC Service Period (SP): During the IDC SP, frame transmission and reception are performed between the first STA and the one or more second STAs; or A method in which frame transmission and reception between the first STA and the one or more second STAs is deferred during the IDC SP. In the first paragraph, A method wherein the first frame is a beacon frame, a probe response frame, or an association response frame. In the first paragraph, A method wherein the first STA is an access point (AP) STA and the second STA is a non-AP 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: Create a Target Wake Time (TWT) element; and A first frame including the TWT element is set to be transmitted to one or more second stations (STAs) through the one or more transceivers, The above TWT element includes a request type field, The above request type field includes a broadcast TWT recommendation field, The first STA, wherein the broadcast TWT recommendation field indicates that the TWT element contains information related to in-device coexistence (IDC). A step of receiving a first frame including a target wake time (TWT) element from a first STA by a second station (STA); and A step of performing an IDC operation by the second STA based on information included in the TWT element, The above TWT element includes a request type field, The above request type field includes a broadcast TWT recommendation field, A method wherein the above broadcast TWT recommendation field indicates that the TWT element contains information related to in-device coexistence (IDC). one or more transmitters and receivers; and comprising one or more processors connected to said one or more transceivers, One or more of the above processors: Receiving a first frame including a target wake time (TWT) element from a first station (STA) through one or more transceivers; and Based on the information contained in the above TWT element, it is set to perform IDC operation, The above TWT element includes a request type field, The above request type field includes a broadcast TWT recommendation field, The second STA, wherein the broadcast TWT recommendation field indicates that the TWT element contains information related to in-device coexistence (IDC). 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 18 based on execution by said one or more processors. One or more non-transitory computer-readable media storing one or more instructions that control execution by one or more processors to perform a method according to any one of claims 1 to 18.

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