Method and apparatus for performing integrated sub-channel selective transmission operation in wireless LAN system

Abstract

A method and apparatus for performing an integrated sub-channel selective transmission (SST) operation in a wireless LAN system are disclosed. A method performed by a first station (STA) in a wireless LAN system according to an embodiment of the present disclosure may comprise the steps of: receiving, from a second STA, a frame including at least one field associated with a channel for an SST operation; and performing the SST operation on the channel based on the at least one field. Here, the at least one field includes a first field indicating whether the SST operation is performed in a first frequency band or a second frequency band, and a second field associated with activation of the channel. According to the first field, the channel may be located in a first link specified for a first frequency band or in a second link specified for a second frequency band.

Description

Technical Field

[0001] The present disclosure relates to methods and apparatus for performing a unified sub-channel selective transmission (SST) operation in a wireless local area network (WLAN) system. Background Art

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

[0003] In order to provide a more improved wireless communication environment, improved technologies for extremely high throughput (EHT) are being discussed. For example, multiple-input multiple-output (MIMO) technologies that support increased bandwidth, efficient use of multiple frequency bands and increased spatial streams, and technologies for adjusting multiple access points (APs) are being studied, and specifically, various technologies for supporting traffic with low latency or real-time characteristics are being studied. In addition, new technologies are being discussed to support ultra-high reliability (UHR), including improvements or extensions to EHT technologies. Summary of the invention

[0004] Technical issues

[0005] A technical object of the present disclosure is to provide a method and apparatus for performing a unified subchannel selective transmission (SST) operation in a wireless local area network (WLAN) system.

[0006] A technical objective of the present disclosure is to provide a method and apparatus for performing an SST operation by defining a unified SST operation element that is simultaneously supportable in different frequency bands.

[0007] The technical objectives to be achieved by the present disclosure are not limited to the above-mentioned technical objectives, and those skilled in the art can clearly understand other technical objectives not described herein through the following description.

[0008] Technical Solution

[0009] According to one aspect of the present disclosure, a method performed by a first station (STA) in a wireless LAN system may include: receiving a frame including at least one field related to a channel for a subchannel selective transmission (SST) operation from a second STA; and performing an SST operation on the channel based on the at least one field. In this article, the at least one field may include a first field indicating whether the SST operation is performed in a first frequency band or in a second frequency band and a second field related to the enabling of the channel, and according to the first field, the channel may be located within a first link designated for the first frequency band or a second link designated for the second frequency band.

[0010] According to another aspect of the present disclosure, a method performed by a second station (STA) in a wireless LAN system may include: constructing a frame including at least one field related to a channel for subchannel selective transmission (SST) operation; and sending a frame including the at least one field to a first STA. In this article, the at least one field may include a first field indicating whether the SST operation is performed in a first frequency band or in a second frequency band and a second field related to the enabling of the channel, and according to the first field, the channel may be located within a first link specified for the first frequency band or a second link specified for the second frequency band.

[0011] Beneficial Effects

[0012] According to the present disclosure, a method and apparatus for performing a unified subchannel selective transmission (SST) operation in a wireless local area network (WLAN) system may be provided.

[0013] According to the present disclosure, a method and apparatus for performing an SST operation by defining an integrated SST operation element that is simultaneously supportable in different frequency bands may be provided.

[0014] According to the present disclosure, the auxiliary channel can be effectively utilized in the SST operation in the wireless LAN system, and the throughput and efficiency can be improved based on this.

[0015] Effects achievable by the present disclosure are not limited to the above-described effects, and other effects not described herein may be clearly understood by those skilled in the relevant art through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are included as a part of the detailed description to help understanding of the present disclosure, provide embodiments of the present disclosure and describe technical features of the present disclosure together with the detailed description.

[0017] Figure 1 A configuration block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0018] Figure 2is a diagram illustrating an exemplary structure of a WLAN system to which the present disclosure can be applied.

[0019] Figure 3 It is a diagram for explaining a link establishment process to which the present disclosure can be applied.

[0020] Figure 4 This is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0021] Figure 5 It is a diagram for explaining a frame transmission operation based on CSMA / CA to which the present disclosure can be applied.

[0022] Figure 6 is a diagram for explaining an example of a frame structure used in a WLAN system to which the present disclosure can be applied.

[0023] Figure 7 is a diagram illustrating an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0024] Figure 8 is a diagram showing an example of a sub-channel selective transmission (SST) operation element format to which the present disclosure may be applied.

[0025] Fig. 9 is a diagram for explaining the operation of the first STA in the SST operation according to the present disclosure.

[0026] Fig.10 is a diagram for explaining the operation of the second STA in the SST operation according to the present disclosure.

[0027] Fig.11 A unified SST operation element format according to an embodiment of the present disclosure is illustrated. DETAILED DESCRIPTION

[0028] Hereinafter, embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed by the accompanying drawings is intended to describe exemplary embodiments of the present disclosure, rather than to represent the only embodiment in which the present disclosure can be implemented. The following detailed description includes specific details to provide a complete understanding of the present disclosure. However, those skilled in the relevant art know that the present disclosure can be implemented without these specific details.

[0029] In some cases, well-known structures and devices may be omitted, or may be shown in the form of a block diagram based on the core functions of each structure and device in order to prevent ambiguity of the concepts of the present disclosure.

[0030] In the present disclosure, when an element is referred to as being "connected", "combined" or "linked" to another element, it may include an indirect connection relationship between another element and a direct connection relationship. In addition, in the present disclosure, the term "comprising" or "having" specifies the presence of the mentioned features, steps, operations, components and / or elements, but does not exclude the presence or addition of one or more other features, stages, operations, components, elements and / or groups thereof.

[0031] In the present disclosure, terms such as "first", "second", etc. are only used to distinguish one element from another element and are not used to limit the elements, and unless otherwise specified, they do not limit the order or importance between elements, etc. Therefore, within the scope of the present disclosure, the first element in an embodiment may be referred to as the second element in another embodiment, and similarly, the second element in an embodiment may be referred to as the first element in another embodiment.

[0032] The terms used in this disclosure are intended to describe specific embodiments, rather than to limit the claims. As used in the description of the embodiments and the appended claims, the singular form is intended to include the plural form, unless the context clearly indicates otherwise. The term "and / or" used in this disclosure may refer to one of the related enumerated items, or mean that it refers to and includes any and all possible combinations of two or more of them. In addition, unless otherwise stated, the " / " between words in this disclosure has the same meaning as "and / or".

[0033] Examples of the present disclosure can be applied to various wireless communication systems. For example, examples of the present disclosure can be applied to wireless LAN systems. For example, examples of the present disclosure can be applied to wireless LANs based on IEEE 802.11a / g / n / ac / ax standards. In addition, examples of the present disclosure can be applied to wireless LANs based on the newly proposed IEEE 802.11be (or EHT) standard. Examples of the present disclosure can be applied to wireless LANs based on the IEEE802.11be version 2 standard corresponding to the additional enhanced technology of the IEEE 802.11be version 1 standard. In addition, examples of the present disclosure can be applied to wireless LANs based on next-generation standards after IEEE 802.11be. In addition, examples of the present disclosure can be applied to cellular wireless communication systems. For example, it can be applied to cellular wireless communication systems based on long-term evolution (LTE) technology and 5G new radio (NR) technology based on the third generation partnership project (3GPP) standard.

[0034] Hereinafter, technical features of examples to which the present disclosure can be applied will be described.

[0035] Figure 1 A block diagram of a wireless communication device according to an embodiment of the present disclosure is illustrated.

[0036] Figure 1 The first device 100 and the second device 200 illustrated in the figure may be replaced with various terms such as terminal, wireless device, wireless transmit / receive unit (WTRU), user equipment (UE), mobile station (MS), user terminal (UT), mobile subscriber station (MSS), mobile subscriber unit (MSU), subscriber station (SS), advanced mobile station (AMS), wireless terminal (WT) or simple user, etc. In addition, the first device 100 and the second device 200 include an access point (AP), a base station (BS), a fixed station, a node B, a base transceiver system (BTS), a network. It may be replaced with various terms such as an artificial intelligence (AI) system, a roadside unit (RSU), a repeater, a router, a relay and a gateway.

[0037] Figure 1 The devices 100 and 200 illustrated in the example may be referred to as stations (STAs). Figure 1 The devices 100 and 200 illustrated in the figure may be referred to by various terms such as a transmitting device, a receiving device, a transmitting STA, and a receiving STA. For example, STA110 and 200 may perform an access point (AP) role or a non-AP role. That is, in the present disclosure, STA110 and 200 may perform the functions of an AP and / or a non-AP. When STA110 and 200 perform an AP function, they may be simply referred to as an AP, and when STA110 and 200 perform a non-AP function, they may be simply referred to as a STA. In addition, in the present disclosure, an AP may also be indicated as an AP STA.

[0038] Reference Figure 1 , the first device 100 and the second device 200 can send and receive radio signals through various wireless LAN technologies (e.g., IEEE802.11 series). The first device 100 and the second device 200 may include interfaces for a media access control (MAC) layer and a physical layer (PHY) that conform to the IEEE802.11 standard.

[0039] In addition, in addition to the wireless LAN technology, the first device 100 and the second device 200 may further support various communication standards (e.g., 3GPP LTE series, 5G NR series standards, etc.) technologies. In addition, the device of the present disclosure may be implemented in various devices such as mobile phones, vehicles, personal computers, augmented reality (AR) devices, and virtual reality (VR) devices. In addition, the STA of the present specification may support various communication services such as voice calls, video calls, data communications, autonomous driving, machine type communications (MTC), machine to machine (M2M), device to device (D2D), IoT (Internet of Things), etc.

[0040] The first device 100 may include 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 may control the memory 104 and / or the transceiver 106, and may be configured to implement the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in the present disclosure. For example, the processor 102 may send a wireless signal including the first information / signal through the transceiver 106 after generating the first information / signal by processing the information in the memory 104. In addition, the processor 102 may receive a wireless signal including the second information / signal through the transceiver 106, and then store the information obtained by the signal processing of the second information / signal in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software codes including instructions for executing all or part of the processing controlled by the processor 102 or for executing the descriptions, functions, processes, suggestions, methods, and / or operational flowcharts included in the present disclosure. Here, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., IEEE 802.11 series). The transceiver 106 may be connected to the processor 102 and may send and / or receive wireless signals through one or more antennas 108. The transceiver 106 may include a transmitter and / or a receiver. The transceiver 106 may be used in conjunction with an RF (radio frequency) unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0041] The second device 200 may include one or more processors 202 and one or more memories 204, and may further include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memory 204 and / or the transceiver 206, and may be configured to implement the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts included in the present disclosure. For example, the processor 202 may generate third information / signals by processing the information in the memory 204, and then send a wireless signal including the third information / signal through the transceiver 206. In addition, the processor 202 may receive a wireless signal including fourth information / signals through the transceiver 206, and then store information obtained by signal processing of the fourth information / signal in the memory 204. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may store software codes including instructions for executing all or part of the processing controlled by the processor 202 or for executing the descriptions, functions, processes, suggestions, methods, and / or operation flowcharts included in the present disclosure. Here, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., IEEE 802.11 series). The transceiver 206 may be connected to the processor 202 and may send and / or receive wireless signals through one or more antennas 208. The transceiver 206 may include a transmitter and / or a receiver. The transceiver 206 may be used in conjunction with an RF unit. In the present disclosure, a device may refer to a communication modem / circuit / chip.

[0042] In the following, the hardware elements of the apparatus 100, 200 will be described in more detail. Without limitation 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 PDUs (protocol data units) and / or one or more SDUs (service data units) according to the description, function, process, suggestion, method, and / or operation flow chart disclosed in the present disclosure. One or more processors 102, 202 may generate messages, control information, data, or information according to the description, function, process, suggestion, method, and / or operation flow chart disclosed in the present disclosure. One or more processors 102, 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, processes, suggestions, and / or methods disclosed in the present disclosure to provide them to one or more transceivers 106, 206. One or more processors 102, 202 may receive a signal (e.g., a baseband signal) from one or more transceivers 106, 206 according to the descriptions, functions, processes, suggestions, methods, and / or operational flow charts included in the present disclosure and obtain a PDU, SDU, message, control information, data, or information.

[0043] One or more processors 102, 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102, 202 may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) may be included in one or more processors 102, 202. The descriptions, functions, processes, suggestions, methods, and / or operational flow charts included in the present disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, processes, functions, and the like. Firmware or software configured to execute the descriptions, functions, processes, suggestions, methods, and / or operational flow charts included in the present disclosure may be included in one or more processors 102, 202, or may be stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The descriptions, functions, processes, suggestions, methods and / or operational flow charts included in the present disclosure may be implemented using firmware or software in the form of codes, instructions and / or instruction sets.

[0044] One or more memories 104, 204 may be connected to one or more processors 102, 202 and may store data, signals, messages, information, programs, codes, instructions, and / or commands in various forms. One or more memories 104, 204 may be configured with ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer-readable storage media, and / or combinations thereof. One or more memories 104, 204 may be located inside and / or outside one or more processors 102, 202. In addition, one or more memories 104, 204 may be connected to one or more processors 102, 202 via various technologies such as wired or wireless connections.

[0045] One or more transceivers 106, 206 may send user data, control information, wireless signals / channels, etc. mentioned in the method and / or operation flow chart of the present disclosure to one or more other devices. One or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc. mentioned in the description, function, process, suggestion, method and / or operation flow chart, etc. included in the present disclosure from one or more other devices. For example, one or more transceivers 106, 206 may be connected to one or more processors 102, 202 and may send and receive wireless signals. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to send user data, control information or wireless signals to one or more other devices. In addition, 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. In addition, one or more transceivers 106, 206 may be connected to one or more antennas 108, 208, and one or more transceivers 106, 206 may be configured to send and receive user data, control information, wireless signals / channels, etc. mentioned in the description, functions, processes, suggestions, methods and / or operation flow charts, etc. included in the present disclosure through one or more antennas 108, 208. In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106, 206 may convert received wireless signals / channels, etc. from RF band signals into baseband signals to process received user data, control information, wireless signals / channels, etc. by using one or more processors 102, 202. One or more transceivers 106, 206 may convert user data, control information, wireless signals / channels, etc. processed by using one or more processors 102, 202 from baseband signals into RF band signals. Thus, one or more of the transceivers 106 , 206 may include (analog) oscillators and / or filters.

[0046] For example, one of the STAs 100 and 200 may perform the expected operation of an AP, and the other of the STAs 100 and 200 may perform the expected operation of a non-AP STA. Figure 1 The transceivers 106 and 206 of the present invention may perform transmission and reception operations of signals (e.g., packets or physical layer protocol data units (PPDUs) compliant with IEEE 802.11a / b / g / n / ac / ax / be / bn). In addition, in the present disclosure, operations of various STAs generating transmission / reception signals or performing data processing or calculations on transmission / reception signals in advance may be performed by Figure 1The processors 102 and 202 are executed. For example, examples of operations of generating a transmission / reception signal or performing data processing or calculation for the transmission / reception signal in advance may include: 1) determining / obtaining / configuring / calculating / decoding / encoding bit information of fields (signal (SIG), short training field (STF), long training field (LTF), data, etc.) included in the PPDU; 2) determining / configuring / obtaining time resources or frequency resources (e.g., subcarrier resources) for fields (SIG, STF, LTF, data, etc.) included in the PPDU; 3) determining / configuring / obtaining a specific sequence (e.g., pilot sequence, STF / LTF sequence, additional sequence applied to SIG) for fields (SIG, STF, LTF, data, etc.) included in the PPDU action; 4) power control operations and / or power saving operations applied to STAs; 5) operations related to ACK signal determination / obtaining / configuring / calculating / decoding / encoding, etc. In addition, in the following example, various information used by various STAs to determine / acquire / configure / calculate / decode / encode transmission signals and reception signals (e.g., information related to fields / subfields / control fields / parameters / power, etc.) may be stored in Figure 1 in the memories 104 and 204.

[0047] Hereinafter, a downlink (DL) may mean a link for communication from an AP STA to a non-AP STA, and a DL PPDU / packet / signal may be transmitted and received through the DL. In DL communication, a transmitter may be a part of an AP STA, and a receiver may be a part of a non-AP STA. An uplink (UL) may mean a link for communication from a non-AP STA to an AP STA, and a UL PPDU / packet / signal may be transmitted and received through the UL. In UL communication, a transmitter may be a part of a non-AP STA, and a receiver may be a part of an AP STA.

[0048] Figure 2 is a diagram illustrating an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0049] The structure of the wireless LAN system may be composed of a plurality of components. A wireless LAN supporting STA mobility transparent to an upper layer may be provided through the interaction of the plurality of components. A basic service set (BSS) corresponds to a basic building block of a wireless LAN. Figure 2 It is exemplarily shown that two BSSs (BSS1 and BSS2) exist, and two STAs (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2) are included as members of each BSS. Figure 2The ellipse representing the BSS in the figure can also be understood as representing the coverage area in which the STAs included in the corresponding BSS maintain communication. This area can be called a basic service area (BSA). When a STA moves outside the BSA, it cannot communicate directly with other STAs in the BSA.

[0050] If you don't consider Figure 2 , the most basic BSS type in the wireless LAN is an independent BSS (IBSS), if the DS is shown in FIG. 1 . For example, an IBSS may have a minimum form containing only two STAs. For example, assuming that other components are omitted, a BSS1 containing only STA1 and STA2 or a BSS2 containing only STA3 and STA4 may correspond to representative examples of IBSSs, respectively. This configuration is possible when STAs can communicate directly without an AP. In addition, in this type of wireless LAN, it is not pre-configured but can be configured when a LAN is needed, and this may be referred to as an ad-hoc network. Since the IBSS does not include an AP, there is no centralized management entity. That is, in the IBSS, STAs are managed in a distributed manner. In the IBSS, all STAs may be composed of mobile STAs, and access to the distributed system (DS) is not allowed, thereby forming a self-contained network.

[0051] The membership of a STA in a BSS can be changed dynamically by turning the STA on or off, entering or exiting a BSS region, etc. In order to become a member of a BSS, a STA can join the BSS using a synchronization process. In order to access all services of the BSS infrastructure, a STA should associate with the BSS. This association can be established dynamically and can include the use of a distributed system service (DSS).

[0052] The direct STA-to-STA distance in a wireless LAN may be limited by PHY performance. In some cases, this distance limitation may be sufficient, but in some cases, communication between STAs at longer distances may be required. A distributed system (DS) can be configured to support extended coverage.

[0053] DS refers to the structure of BSS interconnection. Specifically, Figure 2As shown, the BSS can exist as an extended form of a network composed of multiple BSSs. DS is a logical concept and can be specified by the characteristics of the distributed system medium (DSM). At this point, the wireless medium (WM) and the DSM can be logically separated. Each logical medium is used for different purposes and is used by different components. These media are not limited to being the same, nor are they limited to being different. In this way, the flexibility of the wireless LAN structure (DS structure or other network structure) can be interpreted as multiple media being logically different. That is, the wireless LAN structure can be implemented in various ways, and the corresponding wireless LAN structure can be independently specified by the physical characteristics of each implementation.

[0054] DS can support mobile devices by providing seamless integration of multiple BSSs and providing logical services necessary to address the address leading to the destination. In addition, DS can also include a component called a portal, which is used as a bridge for connection between wireless LAN and other networks (e.g., IEEE 802.X).

[0055] The AP enables access to the DS through the WM for associated non-AP STAs and means an entity that also has STA functionality. Data movement between the BSS and the DS can be performed through the AP. For example, Figure 2 STA2 and STA3 shown in the figure have the function of STA and provide the function of allowing the associated non-AP STA (STA1 and STA4) to access the DS. In addition, since all APs basically correspond to STAs, all APs are addressable entities. The address used by the AP to communicate on the WM is not necessarily the same as the address used by the AP to communicate on the DSM. A BSS composed of an AP and one or more STAs may be referred to as an infrastructure BSS.

[0056] Data sent from one of the STAs associated with the AP to the STA address of the corresponding AP can always be received at the uncontrolled port and can be processed by the IEEE 802.1X port access entity. In addition, when the controlled port is authenticated, the transmitted data (or frame) can be delivered to the DS.

[0057] In addition to the above-mentioned structure of the DS, an extended service set (ESS) may also be configured to provide wide coverage.

[0058] ESS means a network with arbitrary size and complexity consisting of DS and BSS. ESS may correspond to a set of BSSs connected to one DS. However, ESS does not include DS. The ESS network is characterized by being regarded as an IBSS in the logical link control (LLC) layer. The STAs included in the ESS can communicate with each other, and the mobile STA can move from one BSS to another (within the same ESS) transparently for LLC. The APs included in one ESS may have the same service set identifier (SSID). SSID is distinguished from BSSID, which is an identifier of BSS.

[0059] The wireless LAN system does not assume anything about the relative physical location of the BSS, and all of the following forms are possible. The BSS may partially overlap, which is a form commonly used to provide continuous coverage. In addition, the BSS may not be physically connected, and logically, there is no limit on the distance between the BSS. In addition, the BSS may be physically located in the same location, which can be used to provide redundancy. In addition, one (or more than one) IBSS or ESS network may physically exist in the same space as one (or more than one) ESS network. When an ad hoc network operates in a location where an ESS network exists, when physically overlapping wireless networks are configured by different organizations, or when two or more different access and security policies are required in the same location, this may correspond to the form of an ESS network, etc.

[0060] Figure 3 is a diagram for explaining a link establishment process to which the present disclosure can be applied.

[0061] In order for a STA to establish a link with respect to a network and send / receive data, it first discovers the network, performs authentication, establishes association, and needs to perform authentication processing for security. The link establishment processing may also be referred to as a session initiation processing or a session establishment processing. In addition, the discovery, authentication, association, and security establishment processing of the link establishment processing may be collectively referred to as an association processing.

[0062] In step S310, the STA may perform a network discovery operation. The network discovery operation may include a scanning operation of the STA. That is, in order for the STA to access a network, it needs to find a network that it can participate in. The STA should identify compatible networks before participating in a wireless network, and the process of identifying networks present in a specific area is called scanning.

[0063] Scanning schemes include active scanning and passive scanning. Figure 3The network discovery operation including active scanning processing is exemplarily illustrated. In active scanning, the STA performing the scan sends a probe request frame to discover which APs exist around it while the channel moves and waits for a response thereto. The responder sends a probe response frame as a response to the probe request frame to the STA that has sent the probe request frame. Here, the responder may be the STA that last sent a beacon frame in the BSS of the channel being scanned. In the BSS, since the AP sends a beacon frame, the AP becomes the responder, and in the IBSS, the STAs in the IBSS rotate to send beacon frames, so the responder is not constant. For example, a STA that sends a probe request frame on channel 1 and receives a probe response frame on channel 1 may store the BSS-related information included in the received probe response frame, and may move to the next channel (e.g., channel 2), and perform scanning in the same manner (i.e., sending and receiving probe requests / responses on channel 2).

[0064] Although not in Figure 3 , but the scanning operation can be performed in a passive scanning manner. In passive scanning, the STA performing the scan waits for a beacon frame while the channel moves. The beacon frame is one of the management frames defined in IEEE 802.11, and is periodically sent to notify the existence of a wireless network and allow the STA performing the scan to find the wireless network and participate in the wireless network. In the BSS, the AP is used to periodically send beacon frames, and in the IBSS, the STAs within the IBSS rotate to send beacon frames. When the STA performing the scan receives the beacon frame, the STA stores the information of the BSS included in the beacon frame, and records the beacon frame information in each channel while moving to another channel. The STA receiving the beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform scanning in the next channel in the same manner. Comparing active scanning with passive scanning, the advantage of active scanning is that it has less delay and less power consumption than passive scanning.

[0065] After the STA discovers the network, an authentication process may be performed at step S320. In order to clearly distinguish from the security establishment operation of step S340 to be described later, this authentication process may be referred to as a first authentication process.

[0066] The authentication process includes the following process: the STA sends an authentication request frame to the AP, and in response thereto, the AP sends an authentication response frame to the STA. The authentication frame for authentication request / response corresponds to a management frame.

[0067] The authentication frame includes an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a robust security network (RSN), a limited cycle group, etc. This corresponds to some examples of information that can be included in the authentication request / response frame, and can be replaced with other information, or additional information can also be included.

[0068] The STA may send an authentication request frame to the AP. The AP may determine whether to allow authentication of the corresponding STA based on the information included in the received authentication request frame. The AP may provide the result of the authentication process to the STA via an authentication response frame.

[0069] After the STA is successfully authenticated, an association process may be performed at step S330. The association process includes the following processes: the STA sends an association request frame to the AP, and in response, the AP sends an association response frame to the STA.

[0070] For example, the association request frame may include information related to various capabilities, a beacon listening interval, a service set identifier (SSID), supported rates, supported channels, RSN, a mobile domain, supported operation categories, a traffic indication map broadcast request (TIM broadcast request), interworking service capabilities, etc. For example, the association response frame may include information related to various capabilities, a status code, an association ID (AID), supported rates, an enhanced distributed channel access (EDCA) parameter set, a received channel power indicator (RCPI), a received signal-to-noise ratio indicator (RSNI), a mobile domain, a timeout interval (e.g., an association recovery time), an overlapping BSS scan parameter, a TIM broadcast response, a quality of service (QoS) map, etc. This corresponds to some examples of information that may be included in an association request / response frame, and may be replaced with other information, or may also include additional information.

[0071] After the STA successfully associates with the network, a security establishment process may be performed at step S340. The security establishment process at step S340 may be referred to as an authentication process through a robust security network association (RSNA) request / response, the authentication process at step S320 may be referred to as a first authentication process, and the security establishment process at step S340 may also be referred to simply as an authentication process.

[0072] The security establishment process of step S340 may include, for example, a process of establishing a private key through an Extensible Authentication Protocol over LAN (EAPOL) frame using a four-way handshake. In addition, the security establishment process may be performed according to a security scheme not defined in the IEEE 802.11 standard.

[0073] Figure 4 It is a diagram for explaining a backoff process to which the present disclosure can be applied.

[0074] In a wireless LAN system, the basic access mechanism of the medium access control (MAC) is a carrier sense multiple access with collision avoidance (CSMA / CA) mechanism. The CSMA / CA mechanism is also known as the distributed coordination function (DCF) of the IEEE 802.11 MAC, and basically adopts a "listen before talk" access mechanism. According to this type of access mechanism, before starting to send, the AP and / or STA may perform a clear channel assessment (CCA) of sensing the radio channel or medium during a predetermined time interval (e.g., DCF interframe space (DIFS)). As a result of the sensing, if it is determined that the medium is in an idle state, frame transmission is started through the corresponding medium. On the other hand, if it is detected that the medium is occupied or busy, the corresponding AP and / or STA does not start its own transmission, and a delay period (e.g., a random backoff period) for medium access may be set and frame transmission may be attempted after waiting. By applying a random backoff period, since multiple STAs are expected to attempt frame transmission after waiting for different time periods, conflicts can be minimized.

[0075] In addition, the IEEE 802.11 MAC protocol provides a hybrid coordination function (HCF). HCF is based on DCF and point coordination function (PCF). PCF is a synchronous access method based on polling, and refers to a method in which all receiving APs and / or STAs periodically poll to receive data frames. In addition, HCF has enhanced distributed channel access (EDCA) and HCF controlled channel access (HCCA). EDCA is a contention-based access method that provides data frames to multiple users in a direction, and HCCA uses a non-contention-based channel access method that utilizes a polling mechanism. In addition, HCF includes a medium access mechanism for improving the QoS (quality of service) of a wireless LAN, and QoS data can be sent during a contention period (CP) and a contention-free period (CFP).

[0076] Reference Figure 4, the operation based on the random backoff period will be described. When the occupied / busy medium becomes idle, multiple STAs may attempt to send data (or frames). As a method of minimizing conflicts, each of the STAs may select a random backoff count respectively and attempt to send after waiting for the corresponding time slot time. The random backoff count has a pseudo-random integer value and may be determined as one of the values ​​ranging from 0 to CW. Here, CW is a contention window parameter value. The CW parameter is assigned CWmin as an initial value, but may take a value twice as large in the event of a transmission failure (e.g., when an ACK for a transmitted frame is not received). When the CW parameter value reaches CWmax, data transmission may be attempted while maintaining the CWmax value until data transmission is successful, and when data transmission is successful, the CWmin value is reset. The values ​​of CW, CWmin, and CWmax are preferably set to 2n-1 (n=0, 1, 2, ...).

[0077] When the random backoff process starts, the STA continuously monitors the medium in the backoff slot countdown according to the determined backoff count value. When the medium is monitored for occupancy, it stops the countdown and waits, and restarts the remaining part of the countdown when the medium becomes idle.

[0078] exist Figure 4 In the example of , when the packet to be sent arrives at the MAC of STA 3, STA3 can send the frame immediately after confirming that the medium has been idle for up to DIFS. The remaining STAs monitor and wait for the medium to be occupied / busy. At the same time, the data to be sent can also occur in each of STA1, STA2 and STA5, and when the medium is monitored as idle, each STA waits for up to DIFS, and then the countdown of the backoff slot can be performed according to the random backoff count value selected by each STA. Assume that STA2 selects the minimum backoff count value and STA1 selects the maximum backoff count value. That is, the example illustrates the case where the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1 when STA2 completes the backoff count and starts frame transmission. STA1 and STA5 temporarily stop the countdown and wait when STA2 occupies the medium. When STA2's occupation ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and restart the stopped backoff count. That is, frame transmission can start after counting down the remaining backoff slot for the remaining backoff time. Since the remaining backoff time of STA5 is shorter than that of STA1, STA5 starts frame transmission. The data to be transmitted may also occur in STA4 while STA2 occupies the medium. From the perspective of STA4, when the medium becomes idle, STA4 may wait for DIFS, and then may perform a countdown according to a random backoff count value selected by STA4, and start transmitting frames. Figure 4The example shows a case where the remaining backoff time of STA5 accidentally collides with the random backoff count value of STA4. In this case, a collision may occur between STA4 and STA5. When a collision occurs, neither STA4 nor STA5 receives an ACK, so data transmission fails. In this case, STA4 and STA5 can double the CW value, select a random backoff count value, and perform a countdown. While the medium is occupied due to the transmission of STA4 and STA5, STA1 waits, and when the medium becomes idle, STA1 waits DIFS, and then starts frame transmission after the remaining backoff time has passed.

[0079] As in Figure 4 In the example of , a data frame is a frame for sending data forwarded to a higher layer, and may be sent after a backoff performed after DIFS has passed since the medium became idle. In addition, a management frame is a frame for exchanging management information that is not forwarded to a higher layer, and is sent after a backoff is performed after an IFS such as DIFS or a point coordination function IFS (PIFS). As subtype frames of the management frame, there are beacons, association requests / responses, reassociation requests / responses, probe requests / responses, authentication requests / responses, and the like. A control frame is a frame for controlling access to a medium. As subtype frames of the control frame, there are request to send (RTS), clear to send (CTS), acknowledgement (ACK), power save poll (PS-Poll), block ACK (BlockAck), block ACK request (BlockACKReq), empty data packet announcement (NDP announcement), and trigger, and the like. If the control frame is not a response frame of the previous frame, it is sent after a backoff is performed after DIFS has passed, and if it is a response frame of the previous frame, it is sent without performing a backoff after a short IFS (SIFS). The type and subtype of a frame may be identified by the type field and subtype field in the frame control (FC) field.

[0080] Quality of Service (QoS) STA can perform a backoff performed after arbitration IFS (AIFS) (i.e., AIFS (where i is a value determined by AC)) for the access category (AC) to which the frame belongs, and then can send the frame. Here, the frame that can use AIFS may be a data frame, a management frame, or a control frame instead of a response frame.

[0081] Figure 5 is a diagram for explaining a frame transmission operation based on CSMA / CA to which the present disclosure can be applied.

[0082] As described above, in addition to the physical carrier sensing in which the STA directly senses the medium, the CSMA / CA mechanism also includes virtual carrier sensing. Virtual carrier sensing is intended to compensate for problems such as hidden node problems that may occur in medium access. For virtual carrier sensing, the MAC of the STA can use a network allocation vector (NAV). NAV is a value that indicates to other STAs the remaining time until the medium is available for use by the STA that is currently using or has the right to use the medium. Therefore, the value set to NAV corresponds to the period during which the STA sending the frame plans to use the medium, and during the corresponding period, the STA receiving the NAV value is prohibited from accessing the medium. For example, the NAV can be configured based on the value of the "Duration" field of the MAC header of the frame.

[0083] exist Figure 5 In the example of FIG. 1 , it is assumed that STA1 intends to send data to STA2, and STA3 is in a position to be able to eavesdrop on some or all frames sent and received between STA1 and STA2.

[0084] In order to reduce the possibility of transmission conflicts among multiple STAs in the CSMA / CA-based frame transmission operation, a mechanism using RTS / CTS frames can be applied. Figure 5 In the example of , when STA1's transmission is being performed, as a result of STA3's carrier sensing, it can be determined that the medium is in an idle state. That is, STA1 may correspond to a hidden node with respect to STA3. Alternatively, in Figure 5 In the example of , it can be determined that the carrier sensing result medium of STA3 is in an idle state while the transmission of STA2 is being performed. That is, STA2 may correspond to a hidden node with respect to STA3. By exchanging RTS / CTS frames before performing data transmission and reception between STA1 and STA2, STAs outside the transmission range of one of STA1 or STA2 or STAs outside the carrier sensing range of the transmission from STA1 or STA3 may not attempt to occupy the channel during data transmission and reception between STA1 and STA2.

[0085] Specifically, STA1 can determine whether the channel is being used by carrier sensing. In terms of physical carrier sensing, STA1 can determine the channel occupancy idle state based on the energy level or signal correlation detected in the channel. In addition, in terms of virtual carrier sensing, STA1 can use the network allocation vector (NAV) timer to determine the channel occupancy state.

[0086] When the channel is in an idle state during DIFS, STA1 may send an RTS frame to STA2 after performing backoff. When STA2 receives the RTS frame, STA2 may send a CTS frame to STA1 as a response to the RTS frame after SIFS.

[0087] If STA3 cannot eavesdrop on the CTS frame from STA2 but can eavesdrop on the RTS frame from STA1, STA3 can set the NAV timer for the frame transmission period (e.g., SIFS+CTS frame+SIFS+data frame+SIFS+ACK frame) that is continuously transmitted thereafter using the duration information included in the RTS frame. Alternatively, if STA3 can eavesdrop on the CTS frame from STA2, STA3 can set the NAV timer for the frame transmission period (e.g., SIFS+data frame+SIFS+ACK frame) that is continuously transmitted thereafter using the duration information included in the CTS frame even though STA3 cannot eavesdrop on the RTS frame from STA1. That is, if STA3 can eavesdrop on one or more of the RTS frame or the CTS frame from one or more of STA1 or STA2, STA3 can set the NAV accordingly. When STA3 receives a new frame before the NAV timer expires, STA3 can update the NAV timer using the duration information included in the new frame. STA3 does not attempt channel access until the NAV timer expires.

[0088] When STA1 receives a CTS frame from STA2, STA1 may send a data frame to STA2 after SIFS, starting from the time point when reception of the CTS frame is completed. When STA2 successfully receives the data frame, STA2 may send an ACK frame to STA1 after SIFS as a response to the data frame. When the NAV timer expires, STA3 may determine whether the channel is being used by carrier sensing. When STA3 determines that the channel is not being used by other terminals during the DIFS period after the NAV timer expires, STA3 may attempt channel access after the contention window (CW) according to the random backoff has passed.

[0089] Figure 6 is a diagram for explaining an example of a frame structure used in a WLAN system to which the present disclosure can be applied.

[0090] With the help of instructions or primitives (meaning a set of instructions or parameters) from the MAC layer, the PHY layer can prepare a MAC PDU (MPDU) to be transmitted. For example, when a command requesting the PHY layer to start transmitting is received from the MAC layer, the PHY layer switches to a transmission mode, and configures information (e.g., data) provided from the MAC layer in the form of a frame and transmits it. In addition, when the PHY layer detects a valid preamble of a received frame, the PHY layer monitors the header of the preamble and transmits a command notifying the start of reception of the PHY layer to the MAC layer.

[0091] In this manner, information transmission / reception in the wireless LAN system is performed in the form of a frame, and for this purpose, a PHY layer protocol data unit (PPDU) format is defined.

[0092] The basic PPDU may include a short training field (STF), a long training field (LTF), a signal (SIG) field, and a data (Data) field. The most basic PPDU format (e.g., Figure 7 The non-HT (high throughput) shown in the figure may consist of only the legacy-STF (L-STF), the legacy-LTF (L-LTF), the legacy-SIG (L-SIG) field and the data field. In addition, 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.)) and the like may be included between the L-SIG field and the data field.

[0093] STF is a signal used for signal detection, automatic gain control (AGC), diversity selection, precise time synchronization, etc., and LTF is a signal used for channel estimation and frequency error estimation. STF and LTF can be called signals for synchronization and channel estimation of the OFDM physical layer.

[0094] The SIG field may include various information related to the transmission and reception of the PPDU. For example, the L-SIG field consists of 24 bits, and the L-SIG field may include a 4-bit rate field, a 1-bit reserved bit, a 12-bit length field, a 1-bit parity field, and a 6-bit tail field. The RATE field may include information about the modulation and coding rate of the data. For example, the 12-bit length field may include information about the length or duration of the PPDU. For example, the value of the 12-bit length field may be determined based on the type of the PPDU. For example, for non-HT, HT, VHT, or EHT PPDUs, the value of the length field may be determined as a multiple of 3. For example, for HE PPDUs, the value of the length field may be determined as a multiple of 3+1 or a multiple of 3+2.

[0095] The data field may include a service (SERVICE) field, a physical layer service data unit (PSDU) and a PPDU tail bit, and may also include padding bits if necessary. Some bits of the service field may be used for synchronization of the descrambler at the receiving end. The PSDU corresponds to the MAC PDU defined in the MAC layer and may include data generated / used in the upper layer. The PPDU tail bit may be used to return the encoder to the 0 state. The padding bit may be used to adjust the length of the data field in predetermined units.

[0096] MAC PDU is 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 may consist of a MAC PDU and be transmitted / received through a PSDU of a data portion of a PPDU format.

[0097] The MAC header includes a frame control field, a duration / ID field, an address field, etc. The frame control field may include control information required for frame transmission / reception. The duration / ID field may be set to the time for transmitting the corresponding frame, etc. For details of the sequence control, QoS control, and HT control subfields of the MAC header, refer to the IEEE 802.11 standard document.

[0098] 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 additional non-legacy SIG, non-legacy STF, non-legacy LTF (if present)) of a general PPDU format and does not include the remaining part (i.e., the data field).

[0099] Figure 7 is a diagram illustrating an example of a PPDU defined in the IEEE 802.11 standard to which the present disclosure can be applied.

[0100] In standards such as IEEE 802.11a / g / n / ac / ax, various types of PPDUs have been used. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and data fields. The basic PPDU format may also be referred to as a non-HT PPDU format (such as Figure 7 (as shown in (a)).

[0101] Compared to the basic PPDU format, the HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT fields. Figure 7The HT PPDU format shown in (b) may be referred to as an HT mixed format. In addition, an HT greenfield format PPDU may be defined, and this corresponds to a format consisting of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs, and a data field, excluding L-STF, L-LTF, and L-SIG (not shown).

[0102] Compared to the basic PPDU format, an example of the VHT PPDU format (IEEE 802.11ac) additionally includes VHTSIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields (eg, Figure 7 (as shown in (c)).

[0103] Compared to the basic PPDU format, an example of the HE PPDU format (IEEE 802.11ax) additionally includes a repeated L-SIG (RL-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF, a packet extension (PE) field (such as Figure 7 (d) of the HE PPDU format). Some fields may be excluded or their lengths may vary according to the detailed example of the HE PPDU format. For example, the HE-SIG-B field is included in the HE PPDU format for multi-user (MU), and the HE-SIG-B is not included in the HE PPDU format for single user (SU). 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 8μs. The extended range (HE ER) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may vary to 16μs. For example, the RL-SIG may be configured to be the same as the L-SIG. Based on the presence of the RL-SIG, the receiving STA may know that the received PPDU is a HE PPDU or an EHT PPDU, which will be described later.

[0104] The EHT PPDU format may include Figure 7 (e) EHT MU (multi-user) and Figure 7 The EHT TB (trigger-based) PPDU in (f) of FIG. The EHT PPDU format is similar to the HE PPDU format in that it includes the RL-SIG following the L-SIG, but may include the U (Universal)-SIG, the EHT-SIG, the EHT-STF, and the EHT-LTF following the RL-SIG.

[0105] Figure 7The EHT MU PPDU in (e) corresponds to a PPDU carrying one or more data (or PSDU) for one or more users. That is, the EHT MU PPDU can be used for both SU transmission and MU transmission. For example, the EHT MU PPDU can correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0106] Compared with EHT MU PPDU, Figure 7 The EHT TB PPDU in (f) omits the EHT-SIG. A STA that receives a trigger for UL MU transmission (eg, a trigger frame or a triggered response schedule (TRS)) may perform UL transmission based on the EHT TB PPDU format.

[0107] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal Signal), EHT-SIG fields may be coded and modulated so that even legacy STAs may attempt to demodulate and decode, and may be mapped based on a determined subcarrier frequency interval (e.g., 312.5kHz). These may be referred to as pre-EHT modulation fields. Next, the EHT-STF, EHT-LTF, data, PE fields may be coded and modulated so that they may be demodulated and decoded by a STA that successfully decodes a non-legacy SIG (e.g., U-SIG and / or EHT-SIG) and obtains the information included in the field, and may be mapped based on a determined subcarrier frequency interval (e.g., 78.125kHz). These may be referred to as EHT modulation fields.

[0108] 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. In addition, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields may be referred to as non-VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and data fields may be referred to as VHT modulation fields.

[0109] Included in Figure 7The U-SIG in the EHT PPDU format may be configured based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) used for the U-SIG may have a duration of 4 μs, and the U-SIG may have a total duration of 8 μs. Each symbol of the U-SIG may be used to send 26 bits of information. For example, each symbol of the U-SIG may be sent and received based on 52 data tones and 4 pilot tones.

[0110] The U-SIG may be constructed in units of 20 MHz. For example, if an 80 MHz PPDU is constructed, the U-SIG may be duplicated. That is, the same 4 U-SIGs may be included in the 80 MHz PPDU. A PPDU with a bandwidth exceeding 80 MHz may include a different U-SIG.

[0111] For example, A uncoded bits may be sent via U-SIG, the first symbol of U-SIG (e.g., U-SIG-1 symbol) may send the first X bits of information out of a total of A bits of information, and the second symbol of U-SIG (e.g., U-SIG-2 symbol) may send the remaining Y bits of information out of a total of A bits of information. The A bits of information (e.g., 52 uncoded bits) may include a CRC field (e.g., a 4-bit long field) and a tail field (e.g., a 6-bit long field). For example, the tail field may be used to terminate the trellis structure of the convolutional decoder and may be set to 0.

[0112] The bit information sent through U-SIG can be divided into version-independent bits and version-dependent bits. For example, U-SIG can be included in Figure 7 In a new PPDU format not shown in the EHT PPDU format (e.g., UHR PPDU format), and may be included in the format of the U-SIG field included in the EHT PPDU format and the format of the U-SIG field included in the UHR PPDU format, the version-independent bits may be the same, and some or all of the version-related bits may be different.

[0113] For example, the size of the version-independent bit of the U-SIG may be fixed or variable. The version-independent bit may be assigned only to the U-SIG-1 symbol, or to both the U-SIG-1 symbol and the U-SIG-2 symbol. The version-independent bit and the version-dependent bit may be referred to by various names, such as a first control bit and a second control bit.

[0114] For example, the version-independent bits of the U-SIG may include a 3-bit physical layer version identifier (PHY version identifier), and the information may indicate the PHY version (e.g., EHT, UHR, etc.) of the transmitted / received PPDU. 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 is related to UL communication, and the second value of the UL / DL flag field is related to DL communication. The version-independent bits of the U-SIG may include information about the length of a transmit opportunity (TXOP) and information about a BSS color ID.

[0115] For example, the version-related bits of the U-SIG may include information directly or indirectly indicating the type of the PPDU (eg, SUPPDU, MU PPDU, TB PPDU, etc.).

[0116] Information required for PPDU transmission and reception may be included in the U-SIG. For example, the U-SIG may also include information about bandwidth, information about an MCS technology applied to a non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.), information indicating whether a DCM (dual carrier modulation) technology (e.g., a technology for achieving an effect similar to frequency diversity by reusing the same signal on two subcarriers) is applied to the non-legacy SIG, information about the number of symbols used for the non-legacy SIG, and information about whether the non-legacy SIG is generated across the entire frequency band.

[0117] Some of the information required for PPDU transmission and reception may be included in the U-SIG and / or the non-legacy SIG (e.g., EHT-SIG or UHR-SIG, etc.). For example, information about the type of non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information about the length of the non-legacy LTF and the CP (cyclic prefix) length, information about the GI (guard interval) 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, only in the non-legacy SIG, or may be indicated by a combination of information included in the U-SIG and information included in the non-legacy SIG.

[0118] Preamble puncturing may indicate the transmission of a PPDU in which there is no signal in one or more frequency units in the bandwidth of the PPDU. For example, the size of the frequency unit (or the resolution of the preamble puncturing) may be defined as 20 MHz, 40 MHz, etc. For example, preamble puncturing may be applied to a PPDU bandwidth of a predetermined size or greater.

[0119] exist Figure 7In the example of , non-legacy SIGs such as HE-SIG-B and EHT-SIG may include control information for receiving STAs. The non-legacy SIG may be transmitted on at least one symbol, and one symbol may have a length of 4 μs. Information about the number of symbols used for the EHT-SIG may be included in a previous SIG (eg, HE-SIG-A, U-SIG, etc.).

[0120] Non-legacy SIGs such as HE-SIG-B and EHT-SIG may include a common field and a user-specific field. The common field and the user-specific field may be encoded separately.

[0121] In some cases, the common field may be omitted. For example, in a compressed mode that does not apply OFDMA (Orthogonal Frequency Division Multiple Access), the common field may be omitted, and multiple STAs may receive the PPDU (e.g., the data field of the PPDU) through the same frequency band. In a non-compressed mode that applies OFDMA, multiple users may receive the PPDU (e.g., the data field of the PPDU) through different frequency bands.

[0122] The number of user-specific fields may be determined based on the number of users. A user block field may include up to two user fields. Each user field may be associated with a MU-MIMO allocation or may be associated with a non-MU-MIMO allocation.

[0123] The common field may include CRC bits and tail bits, and the length of the CRC bits may be determined to be 4 bits, while the length of the tail bits may be determined to be 6 bits and set to 000000. The common field may include RU allocation information. The RU allocation information may include information about the locations of RUs to which multiple users (ie, multiple receiving STAs) are assigned.

[0124] RU can include multiple subcarriers (or tones). RU can be used when sending signals to multiple STAs based on OFDMA technology. In addition, RU can be defined even when sending signals to one STA. Resources can be allocated to non-traditional STF, non-traditional LTF and data fields in units of RU.

[0125] The RU of applicable size may be defined according to the PPDU bandwidth. The RU may be defined identically or differently for the applied PPDU format (e.g., HEPPDU, EHT PPDU, UHR PPDU, etc.). For example, in the case of an 80MHz PPDU, the RU layout of the HEPPDU and EHT PPDU may be different. The applicable RU size, the number of RUs and RU positions, the DC (direct current) subcarrier positions and numbers, the empty subcarrier positions and numbers, the guard subcarrier positions and numbers, etc. for each PPDU bandwidth may be referred to as a tone plan. For example, a tone plan for high bandwidth may be defined in the form of multiple iterations of a low bandwidth tone plan.

[0126] RUs of various sizes may be defined as 26-tone RUs, 52-tone RUs, 106-tone RUs, 242-tone RUs, 484-tone RUs, 996-tone RUs, 2×996-tone RUs, 3×996-tone RUs, etc. MRUs (multi-RUs) are different from multiple individual RUs and correspond to a group of subcarriers consisting of multiple RUs. For example, one MRU may be defined as 52+26 tones, 106+26 tones, 484+242 tones, 996+484 tones, 996+484+242 tones, 2×996+484 tones, 3×996 tones, or 3×996+484 tones. In addition, the multiple RUs constituting one MRU may or may not be continuous in the frequency domain.

[0127] The specific size of the RU can be reduced or expanded. Therefore, the specific size of each RU in the present disclosure (i.e., the number of corresponding tones) is not restrictive but illustrative. In addition, in the present disclosure, within a predetermined bandwidth (e.g., 20MHz, 40MHz, 80MHz, 160MHz, 320MHz...), the number of RUs can vary according to the RU size.

[0128] Figure 7 The names of each field in the PPDU format are exemplary, and the scope of the present disclosure is not limited by these names. In addition, the examples of the present disclosure can be applied to Figure 7 The PPDU format shown in Figure 7 A new PPDU format that excludes some fields and / or adds some fields.

[0129] Multi-link operation

[0130] A multi-link (ML) operation supported by a STA according to the present disclosure is described below.

[0131] The STA (AP STA and / or non-AP STA) described in the present disclosure may support multi-link (ML) communication. ML communication may mean communication that supports multiple links. Links related to ML communication may include channels (e.g., 20 / 40 / 80 / 160 / 240 / 320 MHz channels) of a frequency band (e.g., 2.4 GHz band, 5 GHz band, 6 GHz band, etc.) in which the STA operates. Multiple links for ML communication may be configured in various ways. For example, multiple links for ML communication supported by one STA may belong to the same frequency band or may belong to different frequency bands. In addition, each link may correspond to a frequency unit (e.g., channel, subchannel, RU, etc.) of a predetermined size. In addition, some or all of the multiple links may be frequency units of the same size, or may be frequency units of different sizes.

[0132] When a STA supports multiple links, the sending and receiving devices supporting each link can operate as one logical STA. That is, MLD means a device with one or more subordinate STAs as logical entities and a single MAC data service and a single MAC service access point (SAP) for logical link control (LLC). Non-AP MLD means an MLD in which each STA attached to the MLD is a non-AP STA. Multi-radio non-AP MLD means a non-AP MLD that supports receiving or exchanging frames on more than one link at a time. AP MLD means an MLD in which each STA attached to the MLD is an AP STA.

[0133] Multi-link operation (MLO) can enable non-AP MLDs to discover, authenticate, associate, and establish multiple links with AP MLDs. Based on the supported capabilities exchanged during the association process, each link can support channel access and frame exchange between non-AP MLDs and AP MLDs. STAs attached to an MLD can select and manage their capabilities and operating parameters independently of other STAs attached to the same MLD.

[0134] Through the multi-link establishment process, the AP MLD and / or the non-AP MLD may send and receive link-related information that the MLD may support. The link-related information may include one or more of the following: information about whether the MLD supports simultaneous transmission and reception (STR) operation or non-simultaneous transmission and reception (NSTR) operation on multiple links, information about the number / upper limit of UL / DL links, information about the location / bandwidth / resources of the UL / DL links, information about available or preferred frame types (e.g., management, control, data, etc.) on at least one UL / DL link, information about available or preferred ACK policies on at least one UL / DL link, or information about available traffic identifiers (TIDs) on at least one UL / DL link.

[0135] An AP MLD (e.g., an NSTR mobile AP MLD) may configure one of the multiple links as a primary link. The AP MLD may perform beacon frames, probe response frames, and group-addressed data frames only on the primary link. The remaining other links in the multiple links may be referred to as non-primary links. An AP MLD operating on a non-primary link may not send beacon frames or probe response frames. In addition, a non-AP MLD may perform frame exchanges only on the primary link during authentication, (re)association, and a 4-way handshake.

[0136] If at least one traffic identifier (TID) is mapped to an established link by the multi-link establishment process, the link may be defined as enabled, and if no TID is mapped to an established link, the link may be defined as disabled. A TID should always be mapped to at least one established link unless admission control is used. By default, a TID is mapped to all established links, so all established links may be enabled.

[0137] When a link is enabled, the link may be used for frame exchange, depending on the power state of the non-AP STA operating on the link. Only MSDUs or A-MSDUs with TIDs mapped to enabled links may be sent on the link. Management frames and control frames may be sent only on enabled links.

[0138] When a link is disabled, the link may not be used for frame exchanges, including management frames for both DL and UL.

[0139] During the multi-link establishment process, the enabling / disabling of each link may be indicated by TID to link mapping. The TID to link mapping may be performed in a default mapping mode or / and a negotiated mapping mode.

[0140] Subchannel Selective Transmission Operation

[0141] SST may include dynamically changing the primary channel within the total bandwidth. For example, SST operation may include operating under the assumption that only a portion of the total bandwidth is the entire bandwidth.

[0142] A STA and an AP having the capability to support SST operation may set up SST operation by negotiating a target wake-up time (TWT) that triggers the activation.

[0143] Here, the TWT request may include a TWT channel field with at most one bit set to 1, which may indicate a secondary channel, and the request includes an RU allocation addressed to a 20 MHz operating STA for the secondary channel.

[0144] The TWT request may include a TWT channel field with all four LSBs or all four MSBs set to 1, which may indicate whether a primary 80 MHz channel or a secondary 80 MHz channel is requested including an RU allocation addressed to an 80 MHz operating STA.

[0145] The TWT response may include a TWT channel field with at most one bit set to 1, which may indicate a secondary channel that will contain RU allocations addressed to 20 MHz operating STAs. The TWT response may include a TWT channel field with all four LSBs or all four MSBs set to 1, which may indicate whether the primary 80 MHz channel or the secondary 80 MHz channel may contain RU allocations addressed to 80 MHz operating STAs.

[0146] STAs and APs that have successfully established SST operations can operate according to the following rules.

[0147] If the AP changes its operating channel or channel width and the secondary channel that triggered the enabled TWT does not exist within the new operating channel or channel width, the AP and STA implicitly terminate the triggered enabled TWT.

[0148] The AP may follow a separate TWT protocol to exchange frames with STAs during a triggered-enabled TWT service period (SP). Here, the AP may ensure that the individually addressed RUs allocated in the DL MU PPUD and trigger frames reside within the subchannel indicated in the TWT channel field of the TWT response and follow the RU constraint rules. The same subchannel may be used for the same STA and all triggered-enabled TWT SPs that overlap in time.

[0149] The STA operating on the secondary channel may not perform an operation mode indication (OMI) operation or an operation mode notification (OMN) operation for changing the operation bandwidth.

[0150] The STA may follow a separate TWT protocol to exchange frames with the AP during a triggered enabled TWT SP. Here, the STA may be available on the subchannel indicated in the TWT channel field of the TWT response at the TWT start time. The STA may not access the medium on the subchannel using the DCF or EDCA function (EDCAF). The STA may not respond to a trigger frame addressed to it unless it detects a frame for which the NAV can be set by performing a CCA. If the STA receives a PPDU on the subchannel, the STA may update the NAV.

[0151] The STA may include a channel switch timing element in the (re)association request frame sent to the AP to indicate the time required for the STA to switch between different subchannels. The received channel switch time may inform the AP of the time period during which the STA may not be able to receive frames before the TWT start time and after the enabled TWT SP is triggered.

[0152] Figure 8 is a diagram showing an example of a sub-channel selective transmission (SST) operation element format to which the present disclosure may be applied.

[0153] The SST operation element format in the existing wireless LAN system may include an 8-bit element ID field, an 8-bit length field, an 8-bit SST enabled channel bitmap field, a 3-bit primary channel offset field, a 1-bit SST channel unit field, and 4-bit reserved bits.

[0154] The element ID field is used to identify the element of the corresponding format, and the length field can indicate the number of eight-bit bytes of the element except the element ID field and the length field.

[0155] The SST Enable Channel Bitmap field may include a bitmap indicating channels activated for SST operation. Each bit of the bitmap corresponds to a channel with the same width as the value of the SST Channel Units field, and the least significant bit (LSB) may correspond to the lowest numbered subchannel in the SST Enable Channel Bitmap field.

[0156] The channel number of each channel in the SST Enabled Channels Bitmap field may be equal to PCN minus (-)OPC plus (+)POS, where PCN is the value of the Primary Channel Number subfield of the most recently transmitted S1G Operation element. OPC is the offset of the primary channel relative to the lowest numbered subchannel in the bitmap, as specified by the value of the Primary Channel Offset field. POS is the position of the channel in the bitmap.

[0157] Setting a bit position in the bitmap to 1 may indicate that the subchannel is enabled for SST operation, but transmission from the SST STA is permitted on the subchannel according to the rules defined in the specification.One or more bits in the bitmap may be equal to 1.

[0158] The Primary Channel Offset field may indicate the relative position of the primary channel relative to the lowest numbered channel in the SST Enabled Channels Bitmap field. For example, setting the Primary Channel Offset field to 2 may indicate that the primary channel is the third subchannel in the SST Activated Channels Bitmap.

[0159] The SST Channel Unit field may indicate the channel width unit of each SST channel. Setting this field to 1 may indicate that the channel width unit is 1 MHz, and setting this field to 2 may indicate that the channel width unit is 2 MHz.

[0160] Methodology for designing uniform SST operating elements

[0161] Hereinafter, the present disclosure proposes a method for defining an enhanced SST operation and related SST operation elements to improve throughput and efficiency in a next generation wireless LAN system.

[0162] Specifically, the present disclosure proposes a unified SST operation element for SST operations in different frequency bands. Hereinafter, the present disclosure describes a sub-7 GHz frequency band and a millimeter wave (mmWave) frequency band as representative examples as different frequency bands.

[0163] In the next generation wireless LAN system (eg, UHR, next wi-fi, etc.), broadband transmission of 480 MHz / 640 MHz may be considered, and in addition, support for specific millimeter wave bands may also be considered.

[0164] In order to effectively support this, a method of defining an enhanced SST operation element, etc. to assign a specific STA to a specific channel may be considered. In this regard, the present disclosure proposes a method of defining a unified SST operation element that can be supported simultaneously in the sub-7 GHz band and the millimeter wave band.

[0165] In the case of the SST operation and the SST operation element in the above-mentioned existing wireless LAN system, a specific channel can be allocated to the STA only within the primary 160MHz channel (i.e., P160). Therefore, allocation to the STA within the secondary 160MHz (i.e., S160) of the 320MHz bandwidth and the 480MHz / 640MHz bandwidth is impossible.

[0166] Taking these points into consideration, the present disclosure proposes, through various examples, a method of defining a unified SST operation element using a new element ID instead of defining an existing SST operation element by extending the existing SST operation element.

[0167] Fig. 9 is a diagram for explaining the operation of the first STA in the SST operation according to the present disclosure.

[0168] In step S910 , the first STA may receive a frame including at least one field related to a channel for an SST operation from a second STA.

[0169] Here, at least one field may include a first field (e.g., a millimeter wave flag field) indicating whether the corresponding SST operation is performed in the first frequency band or in the second frequency band, and a second field (e.g., an SST enabled channel bitmap field) related to enabling of the corresponding channel. For example, the first frequency band may correspond to a frequency band below 7 GHz, and the second frequency band may correspond to a millimeter wave (mmWave) frequency band.

[0170] Here, depending on the value of the first field, the channel (i.e., the channel allocated to the first STA for SST operation) may be located within the first link specified for the first frequency band or the second link specified for the second frequency band. That is, it is assumed that the links related to the SST operation for each frequency band have been specified / indicated. For example, the above-mentioned first link or second link may be indicated by a management frame for multi-link operation between one or more links within the frequency band.

[0171] In step S920 , the first STA may perform an SST operation on the corresponding channel based on at least one field included in the frame in step S910 .

[0172] In this regard, the bandwidth in the second frequency band may be defined to be the same as the bandwidth in the first frequency band, or may be defined by multiplying the bandwidth in the first frequency band by a specific multiple (eg, an upconversion multiple).

[0173] For example, the second field may include bitmap information related to the activation of the channel. At this time, if the bandwidth in the second frequency band is defined by multiplying the bandwidth in the first frequency band by a specific multiple, the resolution of the bitmap information may be set differently depending on the frequency band. For example, if the first field indicates the first frequency band, the resolution may be set to 20 MHz, and if the first field indicates the second frequency band, the resolution may be set to the product of 20 MHz and the specific multiple.

[0174] Additionally or alternatively, the at least one field in step S910 may include a third field indicating the aforementioned resolution.

[0175] Additionally or alternatively, when the maximum bandwidth defined in the first frequency band is 320 MHz, the number of bits of the bitmap information may be set to 16 bits.

[0176] For example, at least one field in step S910 may include a fourth field indicating a channel (e.g., a primary-like channel) used to send and receive control frames or management frames within the channel, which corresponds to 20 MHz or the product of 20 MHz and a specific multiple.

[0177] In this regard, the indication of the fourth field can be based on an offset value. If the first field indicates a first frequency band, the corresponding offset value can be set in units of 20 MHz, and if the first field indicates a second frequency band, the corresponding offset value can be set in units of the product of 20 MHz and a specific multiple. Here, the offset value can be set / applied based on the position of 20 MHz or the product of 20 MHz and a specific multiple in the lowest frequency range (or highest frequency range) within the channel.

[0178] Additionally or alternatively, if the maximum bandwidth defined in the first frequency band is 320 MHz, the number of bits in the fourth field may be set to 4 bits.

[0179] Fig. 9 The method performed by the first STA described in the example of Figure 1 The first device (100) is executed. For example, Figure 1 One or more processors (102) of the first device (100) can receive a frame including at least one field related to a channel for SST operation from a second STA (200) through one or more transceivers (106), and can be configured to perform SST operation on the corresponding channel based on the at least one field.

[0180] For example, one or more processors (102) of the first device (100) may decode at least one field included in the received frame. That is, the one or more processors (102) may be configured to decode one or more fields included in the SST operation element format to determine the channel on which the SST operation is to be performed.

[0181] As a specific example, one or more processors (102) may decode information related to the bandwidth included in the corresponding frame, a first field of information indicating the frequency band (e.g., a millimeter wave flag field), a second field including bitmap information related to the enablement of the channel (e.g., an SST enable channel bitmap field), etc. to identify the frequency band used for SST operation and the location of the channel for the corresponding SST operation. In this regard, it may be necessary to additionally decode information indicating the resolution of the bitmap information (e.g., an SST channel unit field). In addition, one or more processors (102) may be configured to identify the location of a class main channel for sending and receiving control / management frames on the secondary channel to which the first device is assigned. To this end, one or more processors (102) may be configured to decode the class main channel indication information included in the corresponding frame. One or more processors (102) may be configured to control the SST operation of the channel identified based on the above method.

[0182] In addition, one or more memories (104) of the first device (100) may store instructions for executing the operation when executed by one or more processors (102). Fig. 9 Examples or commands of the methods described in the examples described below.

[0183] Fig.10 is a diagram for explaining the operation of the second STA in the SST operation according to the present disclosure.

[0184] In step S1010 , the second STA may construct a frame including at least one field related to a channel for SST operation.

[0185] Here, at least one field may include a first field (e.g., a millimeter wave flag field) indicating whether the corresponding SST operation is performed in the first frequency band or in the second frequency band, and a second field related to enabling of the corresponding channel (e.g., a channel bitmap field for enabling SST). For example, the first frequency band may correspond to a frequency band below 7 GHz, and the second frequency band may correspond to a millimeter wave (mmWave) frequency band.

[0186] Here, depending on the value of the first field, the channel (i.e., the channel allocated to the first STA for SST operation) can be located within the first link specified for the first frequency band or within the second link specified for the second frequency band. That is, it is assumed that the links related to SST operation for each frequency band have been specified / indicated.

[0187] In step S1020, the second STA may send a frame including at least one field to the first STA.

[0188] exist Fig.10In the example of , specific details about at least one field related to SST operation (e.g., a first field, a second field, a third field, a fourth field, etc.), a frequency band, a channel corresponding to a specific 20 MHz / 20 MHz product of a specific multiple (e.g., a primary channel), etc. are provided. Fig. 9 The examples are the same as those described in , so redundant descriptions are omitted.

[0189] Fig.10 The method performed by the second STA described in the example of Figure 1 The second device (200) is executed. For example, Figure 1 One or more processors (202) of the second device (200) may be configured to configure a frame including at least one field related to a channel for SST operation, and send the frame including the at least one field to the first STA (100) through one or more transceivers (206).

[0190] For example, one or more processors (202) of the second device (200) may decode the frame by encoding at least one field related to the channel for SST operation. That is, one or more processors (202) may be configured to encode one or more fields of the SST operation element format to construct a frame for indicating / configuring SST operation.

[0191] As a specific example, one or more processors (202) may encode information related to bandwidth, a first field of information indicating a frequency band (e.g., a millimeter wave flag field), a second field including bitmap information related to channel enablement (e.g., an SST enable channel bitmap field), etc., in order to configure / indicate SST operation. In this regard, encoding of information indicating the resolution of the bitmap information (e.g., an SST channel unit field) may be additionally performed. In addition, one or more processors (202) may set the position of a class main channel for sending and receiving control / management frames on the secondary channel to which the first device is assigned. To this end, one or more processors (202) may be configured to encode the class main channel indication information when configuring the corresponding frame. One or more processors (202) may be configured to configure / indicate SST operation in the first STA (100) based on the aforementioned method.

[0192] In addition, the one or more memories (204) of the second device (200) may store instructions for executing the operation when executed by the one or more processors (202). Fig.10 Examples or instructions of the methods described in the examples described below.

[0193] Fig. 9 and Fig.10The SST operation element format described in the example can correspond to Figure 8 The SST operation element format is compared to the unified SST operation element format including one or more additional, modified, or excluded fields.

[0194] Fig. 9 and Fig.10 Examples of may correspond to some examples of various examples of the present disclosure. In the following, various examples of the present disclosure will be described, including Fig. 9 and Fig.10 .

[0195] Fig.11 A unified SST operation element format according to an embodiment of the present disclosure is illustrated.

[0196] refer to Fig.11 , the unified SST operation element format may consist of an element ID field, a length field, an element ID extension field, and one or more information fields. In this regard, the element ID extension field may not be included in the format.

[0197] For example, with respect to the element ID field, a new element ID value may be used to define a unified SST operation element. In this case, the new element ID value may correspond to an element ID value that has not been previously defined for any purpose. In addition, if an element ID extension field is present, a unified SST operation element may also be defined using specific values ​​of the element ID field and the element ID extension field.

[0198] The length field may indicate the number of bits in the SST operation element excluding the element ID field and the length field in octets.

[0199] A message consisting of one or more information fields may have a variable octet size.

[0200] In this regard, the “information” within the unified SST operation element proposed in the present disclosure may be configured to include one or more of the following fields:

[0201] -Millimeter wave logo field

[0202] -SST Enable Channel Bitmap Field

[0203] -SST channel unit field

[0204] -Class Primary Channel Indicator Field

[0205] - Primary Channel Offset field

[0206] -Replacement of the Class Primary Channel Indicator field

[0207] The names of the above fields are merely examples, and it is not excluded that these names may be replaced with other names and applied within the unified SST operation element of the present disclosure.

[0208] Each of the above fields is described in detail below.

[0209] First, the millimeter wave flag field may be configured as 1 bit, and a value of 0 may be defined to indicate a sub-7 GHz band, and a value of 1 may be defined to indicate a millimeter wave band. Alternatively, the bit value configuration may be set in the opposite manner.

[0210] At this time, in the method proposed in the present disclosure, it is assumed that information about a specific link to be used in each frequency band has been indicated. That is, with respect to the SST operation based on the unified SST operation element in the present disclosure, it is assumed that information about a specific link to be used in a frequency band below 7 GHz and information about a specific link to be used in a millimeter wave frequency band have been indicated / determined.

[0211] For example, the link-related information may be indicated via a management frame for multi-link operation (MLO), as described above in this disclosure.

[0212] Next, an SST enabled channel bitmap field may be defined based on a bandwidth in a sub-7 GHz frequency band and / or a bandwidth in a millimeter wave frequency band.

[0213] The SST Enabled Channels Bitmap field may be used to allocate channels enabled by SST within an already indicated / allocated link.

[0214] For example, the number of bits in the SST enabled channel bitmap field can be determined according to the size of the maximum bandwidth defined in the frequency band below 7 GHz. Specifically, for a 320 MHz bandwidth, the number of bits can be defined as 16 bits, for a 480 MHz bandwidth, the number of bits can be defined as 24 bits, and for a 640 MHz bandwidth, the number of bits can be defined as 32 bits.

[0215] For the frequency band below 7 GHz, each bit of the bitmap information may be mapped from a 20 MHz channel in the low frequency range within the bandwidth to a 20 MHz channel in the high frequency range. That is, for the frequency band below 7 GHz, the resolution of the bitmap information may be 20 MHz. At this time, a value of 1 for each bit may indicate allocation, and a value of 0 may indicate unallocation. Alternatively, the bit value configuration may also be set in the opposite manner.

[0216] For the millimeter wave band, the bandwidth of the lower than 7 GHz band can be used as it is. Alternatively, an up-clocked bandwidth can be used in the millimeter wave band.

[0217] Considering the millimeter wave band, the up-conversion multiple may correspond to the multiple applied to the bandwidth in the sub-7 GHz band. For the sake of clarity of explanation, in the description of the present disclosure, the up-conversion multiple is represented as N_up.

[0218] For example, if N-up is 4, 80 MHz in the sub-7 GHz band may correspond to 80*N_up or 320 MHz in the mmWave band.

[0219] For the millimeter wave band, each bit of the bitmap information can be mapped from a 20*N_up MHz channel in the low frequency range within the bandwidth to a 20*N_up MHz channel in the high frequency range. That is, for the millimeter wave band, the resolution of the bitmap information can be 20*N_up MHz. At this time, the value 1 of each bit can indicate allocation, and the value 0 can indicate unallocated. The bit value configuration can also be set in the opposite way.

[0220] Next, an SST channel unit field may be defined to indicate the size of a channel corresponding to each bit of the SST enabled channel bitmap field.

[0221] For example, if the bandwidth is defined based on up-conversion in a millimeter wave band, a corresponding SST channel unit field may be defined.

[0222] For another example, if the bandwidth is defined based on upscaling in the millimeter wave band, the channel size may be implicitly indicated by the indication of the millimeter wave flag field. Considering this, only the millimeter wave flag field may be defined, and the SST channel unit field may not be defined.

[0223] For another example, if the bandwidth is defined based on upscaling in the millimeter wave band, the SST in the millimeter wave band can be implicitly indicated by the SST channel unit field. Considering this, only the SST channel unit field can be defined, and the millimeter wave flag field may not be defined.

[0224] When the SST channel unit field is configured / defined, this field can be configured as 1 bit. The 0 value of this 1 bit can be defined to indicate 20 MHz, and the 1 value can be defined to indicate 20*N_up MHz. For example, for frequency bands below 7 GHz, this field can always be set to 0, and for millimeter wave bands, this field can always be set to 1. Alternatively, the bit value configuration can also be set in the opposite way.

[0225] Additionally or alternatively, if the bandwidth is defined as the same size as before in the millimeter wave band, ie, if the above-mentioned upscaling is not applied, the SST channel unit field may not be defined.

[0226] Next, the primary-like channel indication field may be defined to indicate a primary-like channel that may be used to send and receive control / management frames on the channel allocated by the SST enabled channel bitmap field.

[0227] Here, the primary-like channel may mean a channel that functions similarly to a primary 20 MHz channel (ie, P20) within a channel to which a STA is assigned.

[0228] Based on this field, even if a STA is assigned to a secondary channel, a specific 20 MHz channel (e.g., for sub-7 GHz bands) or 20*N_up MHz channel (e.g., for mmWave bands) within the secondary channel may be utilized / defined as a primary-like channel.

[0229] To indicate a quasi-primary channel as described above, an offset-based approach may be applied.

[0230] That is, a method may be applied to indicate how far a 20 MHz channel or 20*N_up MHz channel is from the leftmost (or rightmost) 20 MHz channel or 20*N_up MHz channel within the channel to which the STA is assigned. The method of indicating the offset based on the leftmost side may be the same as the method of mapping from the minimum value to the lowest 20 MHz channel or 20*N_up MHz channel. Here, a 20 MHz channel may be considered in the case of a band lower than 7 GHz or a millimeter wave band to which upconversion is not applied, and a 20*N_up MHz channel may be considered in the case of a millimeter wave band.

[0231] For example, if the STA is assigned to a secondary 160 MHz channel in the sub-7 GHz band, the quasi-primary channel indication field set to a value of 3 may indicate that the fourth 20 MHz channel among the four 20 MHz channels constituting the channel is a quasi-primary channel.

[0232] In this regard, the number of bits of the quasi-primary channel indication field may be determined based on the size of the maximum bandwidth.

[0233] For example, if the maximum bandwidth is 640 MHz in the sub-7 GHz band, or if the maximum bandwidth is 640 MHz or 640*N_up MHz in the millimeter wave band, the field may consist of 5 bits or 4 bits. Here, when the SST Enable Channel Bitmap field allocates the entire 640 MHz or 640*N_up MHz, a field consisting of 5 bits may be considered. When the SST Enable Channel Bitmap field allocates the entire 320 MHz or 320*N_up MHz, a field consisting of 4 bits may be considered.

[0234] For another example, if the maximum bandwidth is 480 MHz in the sub-7 GHz band, or if the maximum bandwidth is 480 MHz or 480*N_up MHz in the millimeter wave band, the field may consist of 5 bits or 4 bits. Here, when the SST Enable Channel Bitmap field allocates the entire 480 MHz or 480*N_up MHz, a field consisting of 5 bits may be considered. When the SST Enable Channel Bitmap field allocates the entire 320 MHz or 320*N_up MHz, a field consisting of 4 bits may be considered.

[0235] For another example, if the maximum bandwidth is 320 MHz in the frequency band below 7 GHz, or if the maximum bandwidth is 320 MHz or 320*N_up MHz in the millimeter wave frequency band, the field may consist of 4 bits or 3 bits. Here, when the SST Enable Channel Bitmap field allocates the entire 320 MHz or 320*N_up MHz, a field consisting of 4 bits may be considered. When the SST Enable Channel Bitmap field allocates the entire 160 MHz or 160*N_up MHz, a field consisting of 3 bits may be considered.

[0236] In addition, the value of the primary-like channel indication field can be set to a meaningful value only when the STA is assigned to a channel larger than a certain size. This is because when considering the case of assigning STAs to channels of smaller size, the complexity of assigning primary-like channels may be very large.

[0237] For example, in the sub-7 GHz band, if the maximum bandwidth is 640 MHz or 480 MHz, this field may only make sense if the STA is assigned to 320 MHz or 160 MHz. Similarly, in the mmWave band, if the maximum bandwidth is 640 MHz / 480 MHz or 640*N_up MHz / 480*N_up MHz, this field may only make sense if the STA is assigned to 320 MHz / 160 MHz or 320*N_up MHz / 160*N_up MHz.

[0238] For another example, if the maximum bandwidth in the sub-7 GHz band is 320 MHz, this field may only be meaningful if the STA is assigned to 160 MHz or 80 MHz. Similarly, if the maximum bandwidth in the mmWave band is 320 MHz or 320*N_up MHz, this field may only be meaningful if the STA is assigned to 160 MHz / 80 MHz or 160*N_up MHz / 80*N_up MHz.

[0239] In the case where the STA is assigned to a small channel other than the above example, the value of the primary channel indication field in the unified SST operation element format may be reserved or set to a specific value. For example, all bit values ​​may be set to 0 or 1.

[0240] Next, the primary channel offset field may be defined as indicating the position of P20 or P20*N_up as an offset value based on a 20MHz channel or a 20*N_up MHz channel located at the leftmost position within the channel to which the corresponding STA is assigned. Here, in the case of a band lower than 7GHz or a millimeter wave band to which upconversion is not applied, a 20MHz channel / P20 may be considered, and in the case of a millimeter wave band, a 20*N_up MHz channel / P20*N_up may be considered.

[0241] The position indication for the primary channel may be performed in the form of a cyclic shift of an offset value.

[0242] Additionally, the number of bits in the primary channel offset field may be determined based on the size of the maximum bandwidth.

[0243] For example, if the maximum bandwidth in the sub-7 GHz band is 640 MHz or 480 MHz, the primary channel offset field may consist of 5 bits. Similarly, if the maximum bandwidth in the millimeter wave band is 640 MHz / 480 MHz or 640*N_up MHz / 480*N_up MHz, the primary channel offset field may consist of 5 bits.

[0244] For another example, if the maximum bandwidth in the sub-7 GHz band is 320 MHz, the primary channel offset field may consist of 4 bits. Similarly, if the maximum bandwidth in the millimeter wave band is 320 MHz or 320*N_up MHz, the primary channel offset field may consist of 4 bits.

[0245] Next, an alternative method of the primary-like channel indication field is described.

[0246] In the description of the method, a 20 MHz channel / P20 may be considered for a sub-7 GHz band or a millimeter wave band to which upconversion is not applied, and a 20*N_up MHz channel / P20*N_up may be considered for a millimeter wave band.

[0247] For example, instead of indicating a class primary channel for each allocated channel (ie, based on the indication of the class primary channel indication field described above), a field in the BSS indicating a new class primary channel other than P20 or P20*N_up may be considered.

[0248] This field may be defined to indicate only one additional primary-like channel within the BSS. In this regard, by defining multiple fields, multiple primary-like channels may be defined within the BSS.

[0249] That is, instead of defining / indicating a class primary channel for each channel allocated by SST within a particular link within a frequency band, multiple class primary channels may be defined within a link. In this regard, if multiple class primary channels exist within a link, multiple fields according to the method may exist.

[0250] In addition, with respect to the method, an offset value based on / according to a cyclic shift may be used to configure / indicate the position of a quasi-primary channel in P20 or P20*N_up. Alternatively, a method for configuring the position of a quasi-primary channel in a 20 MHz channel or a 20*N_up MHz channel located at the leftmost (or rightmost) position within the allocated channel may be used based on / according to an offset value of a cyclic shift.

[0251] Additionally, the number of bits in the field according to this method may be determined based on the size of the maximum bandwidth.

[0252] For example, if the maximum bandwidth in the sub-7 GHz band is 480 MHz / 640 MHz, this field may consist of 5 bits. In addition, if the maximum bandwidth in the millimeter wave band is 480 MHz / 640 MHz or 480*N_up MHz / 640*N_up MHz, this field may also consist of 5 bits.

[0253] For another example, if the maximum bandwidth in the frequency band below 7 GHz is 320 MHz, this field may consist of 4 bits. In addition, if the maximum bandwidth in the millimeter wave frequency band is 320 MHz or 320*N_up MHz, this field may consist of 4 bits.

[0254] In existing wireless LAN systems, SST operations in the frequency band below 7 GHz are defined only within a 160 MHz bandwidth. In contrast, the method proposed in the present disclosure can support SST operations within the millimeter wave band, and can configure / indicate SST operations by considering a 320 MHz bandwidth and a wide bandwidth (e.g., a 480 MHz / 640 MHz bandwidth).

[0255] According to the method proposed in the present disclosure, it is possible to simultaneously support integrated SST operation elements in the sub-7 GHz band and the millimeter wave band, thereby reducing design complexity and improving efficiency in signaling. In addition, according to the method proposed in the present disclosure, by supporting SST operations taking into account wide bandwidth, a new effect of improving throughput and efficiency can be achieved.

[0256] The above-mentioned embodiments are to combine the elements and features of the present disclosure in a predetermined form. Unless otherwise explicitly mentioned, each element or feature should be considered as optional. Each element or feature can be implemented in a form that is not combined with other elements or features. In addition, the embodiments of the present disclosure may include combined partial elements and / or features. The order of the operations described in the embodiments of the present disclosure may be changed. Some elements or features of an embodiment may be included in other embodiments, or may be replaced by corresponding elements or features of other embodiments. Obviously, the embodiments may include claims that do not have a clear reference relationship in the combined claims, or may be included as new claims by modification after application.

[0257] It is clear to those skilled in the relevant art that the present disclosure can be implemented in other specific forms within the scope of the essential features of the present disclosure. Therefore, the above detailed description should not be interpreted restrictively in every aspect, but should be considered as illustrative. The scope of the present disclosure should be determined by the reasonable interpretation of the attached claims, and all changes within the equivalent scope of the present disclosure are included in the scope of the present disclosure.

[0258] The scope of the present disclosure includes software or machine executable commands (e.g., operating systems, applications, firmware, programs, etc.) that perform operations in a device or computer according to the methods of various embodiments, and non-transitory computer-readable media that enable software or commands, etc. to be stored and executable in a device or computer. Commands that can be used to program a processing system that performs the features described in the present disclosure can be stored in a storage medium or a computer-readable storage medium, and the features described in the present disclosure can be implemented by using a computer program product including such a storage medium. The storage medium may include a high-speed random access memory, such as DRAM, SRAM, DDR RAM, or other random access solid-state storage devices, but is not limited thereto, and it may include a 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 located away from the processor. The memory, or alternatively, the non-volatile memory device in the memory includes a non-transitory computer-readable storage medium. The features described in this disclosure may be stored in any machine-readable medium to control the hardware of a processing system, and may be integrated into software and / or firmware that allows the processing system to interact with other mechanisms using the results from the embodiments of this disclosure. Such software or firmware may include, but is not limited to, application code, device drivers, operating systems, and execution environments / containers.

[0259] Industrial Applicability

[0260] The method proposed in the present disclosure is mainly described based on an example applied to a system based on IEEE 802.11 (5G system), but can be applied to various WLAN or wireless communication systems other than the system based on IEEE 802.11.

Claims

1. A method performed by a first station STA in a wireless LAN system, the method comprising the following steps: receiving, from a second STA, a frame including at least one field related to a channel for a subchannel selective transmission (SST) operation; as well as performing the SST operation on the channel based on the at least one field, The at least one field includes a first field and a second field, the first field indicates whether the SST operation is performed in a first frequency band or a second frequency band, and the second field is related to the enabling of the channel, and According to the first field, the channel is located within a first link designated for the first frequency band or within a second link designated for the second frequency band.

2. The method according to claim 1, in, The first frequency band corresponds to a sub-7 GHz frequency band, and the second frequency band corresponds to a millimeter wave (mmWave) frequency band.

3. The method according to claim 1, in, The bandwidth in the second frequency band is defined to be equal to the bandwidth in the first frequency band, or The bandwidth in the second frequency band is defined by multiplying the bandwidth in the first frequency band by a specific multiple.

4. The method according to claim 3, in, The second field includes bitmap information related to the enabling of the channel, and Wherein, based on defining the bandwidth in the second frequency band by multiplying the bandwidth in the first frequency band by the specific multiple, the resolution of the bitmap information is set differently according to the frequency band.

5. The method according to claim 4, in, Based on the first field indicating the first frequency band, the resolution is set to 20 MHz, and Wherein, based on the first field indicating the second frequency band, the resolution is set to the product of 20 MHz and the specific multiple.

6. The method according to claim 4, in, The at least one field includes a third field indicating the resolution.

7. The method according to claim 4, in, Based on the maximum bandwidth defined in the first frequency band being 320 MHz, the number of bits of the bitmap information is set to 16 bits.

8. The method according to claim 3, in, The at least one field includes a fourth field indicating a channel corresponding to 20 MHz or a product of 20 MHz and a specific multiple, for transmitting and receiving a control frame or a management frame within the channel.

9. The method according to claim 8, in, The indication by the fourth field is based on an offset value, wherein the offset value is set in units of 20 MHz based on the first field indicating the first frequency band, and Wherein, based on the first field indicating the second frequency band, the offset value is set in units of the product of 20 MHz and the specific multiple.

10. The method according to claim 9, in, The offset value is set based on a position of 20 MHz or a product of 20 MHz and the specific multiple in a lowest frequency range within the channel.

11. The method according to claim 8, in, Based on the maximum bandwidth defined in the first frequency band being 320 MHz, the number of bits of the fourth field is set to 4 bits.

12. The method according to claim 1, in, The first link or the second link is indicated by a management frame for a multi-link operation.

13. A device for a first station STA in a wireless local area network (WLAN) system, the device comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: receiving, from a second STA, a frame including at least one field related to a channel for a subchannel selective transmission (SST) operation; and performing the SST operation on the channel based on the at least one field, The at least one field includes a first field and a second field, the first field indicates whether the SST operation is performed in a first frequency band or a second frequency band, and the second field is related to the enabling of the channel, and According to the first field, the channel is located within a first link designated for the first frequency band or within a second link designated for the second frequency band.

14. A method performed by a second station (STA) in a wireless LAN system, the method comprising the following steps: constructing a frame including at least one field associated with a channel for subchannel selective transmission (SST) operation; as well as sending the frame including the at least one field to a first STA, The at least one field includes a first field and a second field, the first field indicates whether the SST operation is performed in a first frequency band or a second frequency band, and the second field is related to the enabling of the channel, and According to the first field, the channel is located within a first link designated for the first frequency band or within a second link designated for the second frequency band.

15. A device for a second station STA in a wireless local area network (WLAN) system, the device comprising: at least one transceiver; as well as at least one processor connected to the at least one transceiver, Wherein, the at least one processor is configured to: constructing a frame including at least one field associated with a channel for subchannel selective transmission (SST) operation; and sending the frame including the at least one field to a first STA, The at least one field includes a first field and a second field, the first field indicates whether the SST operation is performed in a first frequency band or a second frequency band, and the second field is related to the enabling of the channel, and According to the first field, the channel is located within a first link designated for the first frequency band or within a second link designated for the second frequency band.

16. A processing unit configured to control a station STA in a wireless local area network (WLAN) system, the processing unit comprising: at least one processor; as well as At least one computer memory operatively connected to the at least one processor, the at least one computer memory storing instructions for performing the method according to any one of claims 1 to 12 upon execution by the at least one processor.

17. At least one non-transitory computer-readable medium storing at least one instruction, wherein: The at least one instruction is executed by at least one processor to control a device to perform the method according to any one of claims 1 to 12 in a wireless local area network (WLAN) system.

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