Method and device for transmitting or receiving various physical layer protocol data units in wireless LAN system

Abstract

Disclosed are a method and device for transmitting or receiving various physical layer protocol data units in a wireless LAN system. The method according to an embodiment of the present disclosure may comprise the steps in which: a first access point (AP) generates a first physical layer protocol data unit (PPDU) including a universal-signal (U-SIG) field and an additional SIG field; and the first AP transmits the first PPDU to a station (STA). On the basis that the first PPDU is an ultra-high reliability (UHR) multi-user (MU) PPDU and the additional SIG field is an UHR-SIG field, the U-SIG field includes an uplink / downlink (UL / DL) field and a PPDU type and compression mode field, and with respect to coordinated spatial reuse (Co-SR) transmission or coordinated beamforming (Co-BF) transmission in which the first AP and the second AP participate, a spatial reuse subfield included in the UHR-SIG field may be set to 15 corresponding to parameterized spatial reuse (PSR) prohibited. S910%%%Generate first PPDU (MU PPDU or ELR PPDU) including U-SIG field and additional SIG field (UHR-SIG or ELR-SIG) S920%%%Transmit first PPDU to STA

Description

Method and device for transmitting or receiving various physical layer protocol data units in a wireless LAN system

[0001] The present disclosure relates to a method and apparatus for transmitting or receiving various physical layer protocol data units (PPDUs) in a Wireless Local Area Network (WLAN) system.

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

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

[0004] The technical problem of the present disclosure is to provide a method and apparatus for transmitting or receiving various PPDUs in a wireless LAN (WLAN) system.

[0005] The technical problems to be solved in this disclosure are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this disclosure belongs from the description below.

[0006] A method according to one aspect of the present disclosure may include the step of generating a first physical layer protocol data unit (PPDU) by a first access point (AP), the PPDU comprising a universal-signal (U-SIG) field and an additional SIG field; and transmitting the first PPDU to a station (STA) by the first AP. Based on the fact that the first PPDU is an ultra-high reliability (UHR) multi-user (MU) PPDU and the additional SIG field is a UHR-SIG field: the U-SIG field comprises an uplink / downlink (UL / DL) field and a PPDU type and compression mode field; For a Co-SR (coordinated spatial reuse) transmission or Co-BF (coordinated beamforming) transmission in which the first AP and the second AP participate, the spatial reuse subfield included in the UHR-SIG field may be set to a value of 15, corresponding to PSR (parameterized spatial reuse) prohibited.

[0007] A method according to a further aspect of the present disclosure may include: receiving a first physical layer protocol data unit (PPDU) from a first access point (AP) by a station (STA), the PPDU comprising a universal-signal (U-SIG) field and an additional SIG field; and decoding the first PPDU. Based on the fact that the first PPDU is an ultra-high reliability (UHR) multi-user (MU) PPDU and the additional SIG field is a UHR-SIG field: the U-SIG field comprises an uplink / downlink (UL / DL) field and a PPDU type and compression mode field; For a Co-SR (coordinated spatial reuse) transmission or Co-BF (coordinated beamforming) transmission in which the first AP and the second AP participate, the spatial reuse subfield included in the UHR-SIG field may be set to a value of 15, corresponding to PSR (parameterized spatial reuse) prohibited.

[0008] According to the present disclosure, a method and apparatus for transmitting or receiving various PPDUs in a wireless LAN (WLAN) system may be provided.

[0009] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below.

[0010] The accompanying drawings, which are included as part of the detailed description to aid in understanding the present disclosure, provide embodiments of the present disclosure and explain the technical features of the present disclosure together with the detailed description.

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

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

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

[0014] FIG. 4 is a drawing illustrating a backoff process to which the present disclosure may be applied.

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

[0016] FIG. 6 is a drawing for illustrating an example of a frame structure used in a wireless LAN system to which the present disclosure may be applied.

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

[0018] FIG. 8 is a diagram illustrating various transmission and reception techniques in a MAP environment to which the present disclosure can be applied.

[0019] FIG. 9 is a drawing showing an example of the operation of a first AP according to the present disclosure.

[0020] FIG. 10 is a drawing showing an example of the operation of an STA according to the present disclosure.

[0021] FIG. 11 is a diagram showing an example of a frame exchange sequence for Co-SR to which the present disclosure can be applied.

[0022] FIG. 12 is a drawing showing examples of UHR PPDU formats to which the present disclosure can be applied.

[0023] Hereinafter, preferred embodiments according to the present disclosure will be described in detail with reference to the accompanying drawings. The detailed description disclosed below, together with the accompanying drawings, is intended to describe exemplary embodiments of the present disclosure and is not intended to represent the only embodiment in which the present disclosure may be practiced. The following detailed description includes specific details to provide a complete understanding of the present disclosure. However, those skilled in the art will know that the present disclosure may be practiced without such specific details.

[0024] In some cases, to avoid obscuring the concept of the present disclosure, known structures and devices may be omitted or illustrated in the form of a block diagram focusing on the core functions of each structure and device.

[0025] In the present disclosure, when a component is described as being “connected,” “combined,” or “joined” with another component, this may include not only a direct connection but also an indirect connection in which another component exists between them. Furthermore, in the present disclosure, the terms “comprising” or “having” specify the presence of the mentioned features, steps, actions, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, actions, elements, components, and / or groups thereof.

[0026] In the present disclosure, terms such as "first," "second," etc. are used solely for the purpose of distinguishing one component from another and are not used to limit the components, nor do they limit the order or importance of the components unless specifically stated otherwise. Accordingly, within the scope of the present disclosure, a first component in one embodiment may be referred to as a second component in another embodiment, and likewise, a second component in one embodiment may be referred to as a first component in another embodiment.

[0027] The terms used in this disclosure are for the description of specific embodiments and are not intended to limit the claims. As used in the description of embodiments and in the appended claims, the singular form is intended to include the plural form unless the context clearly indicates otherwise. The term "and / or" as used in this disclosure may refer to any one of the related enumerated items, or refers to and includes any and all possible combinations of two or more of them. Additionally, the " / " between words in this disclosure has the same meaning as "and / or" unless otherwise noted.

[0028] The embodiments of the present disclosure may be applied to various wireless communication systems. For example, the embodiments of the present disclosure may be applied to wireless LAN systems. For example, the embodiments of the present disclosure may be applied to wireless LANs based on IEEE 802.11a / g / n / ac / ax / be standards. Furthermore, the embodiments of the present disclosure may be applied to wireless LANs based on newly proposed IEEE 802.11bn (or UHR) standards. Additionally, the embodiments of the present disclosure may be applied to wireless LANs based on next-generation standards following IEEE 802.11bn. Furthermore, the embodiments of the present disclosure may be applied to cellular wireless communication systems. For example, they may be applied to cellular wireless communication systems based on LTE (Long Term Evolution) series technologies and 5G NR (New Radio) series technologies of 3GPP (3rd Generation Partnership Project) standards.

[0029] The following describes the technical features to which the examples of the present disclosure may be applied.

[0030] FIG. 1 illustrates a block diagram of a wireless communication device according to one embodiment of the present disclosure.

[0031] The first device (100) and the second device (200) exemplified in FIG. 1 may be replaced with various terms such as terminal, wireless device, WTRU (Wireless Transmit Receive Unit), UE (User Equipment), MS (Mobile Station), UT (user terminal), MSS (Mobile Subscriber Station), MSS (Mobile Subscriber Unit), SS (Subscriber Station), AMS (Advanced Mobile Station), WT (Wireless terminal), or simply user. Additionally, the first device (100) and the second device (200) may be replaced with various terms such as access point (AP), BS (Base Station), fixed station, Node B, BTS (base transceiver system), network, AI (Artificial Intelligence) system, RSU (road side unit), repeater, router, relay, gateway, etc.

[0032] The device (100, 200) exemplified in FIG. 1 may be referred to as a station (STA). For example, the device (100, 200) exemplified in FIG. 1 may be referred to by various terms such as a transmitting device, a receiving device, a transmitting STA, or a receiving STA. For example, the STA (110, 200) may perform the role of an access point (AP) or a non-AP. That is, in the present disclosure, the STA (110, 200) may perform the functions of an AP and / or a non-AP. If the STA (110, 200) performs the AP function, it may simply be referred to as an AP, and if the STA (110, 200) performs the non-AP function, it may simply be referred to as a STA. Additionally, in the present disclosure, the AP may also be indicated as an AP STA.

[0033] Referring to FIG. 1, the first device (100) and the second device (200) can transmit and receive wireless signals through various wireless LAN technologies (e.g., IEEE 802.11 series). The first device (100) and the second device (200) may include interfaces for the medium access control (MAC) layer and the physical layer (PHY) that comply with the specifications of the IEEE 802.11 standard.

[0034] In addition, the first device (100) and the second device (200) may additionally support various communication standards other than wireless LAN technology (e.g., 3GPP LTE series, 5G NR series standards, etc.). In addition, the device of the present disclosure may be implemented as various devices such as mobile phones, vehicles, personal computers, AR (Augmented Reality) equipment, VR (Virtual Reality) equipment, etc. Furthermore, the STA of the present specification may support various communication services such as voice calls, video calls, data communication, autonomous driving, MTC (Machine-Type Communication), M2M (Machine-to-Machine), D2D (Device-to-Device), and IoT (Internet-of-Things).

[0035] The first device (100) includes one or more processors (102) and one or more memories (104), and may additionally include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memory (104) and / or transceivers (106) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or sequences of operation disclosed in this disclosure. For example, the processor (102) may process information within the memory (104) to generate a first information / signal and then transmit a wireless signal containing the first information / signal through the transceiver (106). Additionally, the processor (102) may receive a wireless signal containing a second information / signal through the transceiver (106) and then store information obtained from the signal processing of the second information / signal in the memory (104). Memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, memory (104) may store software code including instructions for performing some or all of the processes controlled by the processor (102) or for performing the descriptions, functions, procedures, proposals, methods, and / or sequences of operation disclosed in this disclosure. Here, the processor (102) and memory (104) may be part of a communication modem / circuit / chip designed to implement wireless LAN technology (e.g., IEEE 802.11 series). A transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals through one or more antennas (108). The transceiver (106) may include a transmitter and / or receiver. The transceiver (106) may be combined with an RF (Radio Frequency) unit. In the present disclosure, the device may refer to a communication modem / circuit / chip.

[0036] The second device (200) includes one or more processors (202) and one or more memories (204), and may additionally include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memory (204) and / or transceivers (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or sequences of operation disclosed in this disclosure. For example, the processor (202) may process information within the memory (204) to generate a third information / signal and then transmit a wireless signal containing the third information / signal through the transceiver (206). Additionally, the processor (202) may receive a wireless signal containing a fourth information / signal through the transceiver (206) and then store information obtained from the 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 code containing instructions for performing some or all of the processes controlled by the processor (202) or for performing the descriptions, functions, procedures, proposals, methods, and / or sequences of operation disclosed in this 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 transmit and / or receive wireless signals through one or more antennas (208). The transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be used in combination with an RF unit. In the present disclosure, the device may refer to a communication modem / circuit / chip.

[0037] Hereinafter, hardware elements of the device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this disclosure. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this disclosure. One or more processors (102, 202) may generate a signal (e.g., a baseband signal) including a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this disclosure and provide it 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) and may obtain a PDU, SDU, message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this disclosure.

[0038] One or more processors (102, 202) may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this disclosure may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this disclosure may be included in one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this disclosure may be implemented using firmware or software in the form of code, instructions, and / or sets of instructions.

[0039] One or more memories (104, 204) may be connected to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, codes, instructions, and / or commands. One or more memories (104, 204) may be composed of ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer read storage media, and / or combinations thereof. One or more memories (104, 204) may be located inside and / or outside of one or more processors (102, 202). Additionally, one or more memories (104, 204) may be connected to one or more processors (102, 202) through various technologies such as wired or wireless connections.

[0040] One or more transceivers (106, 206) may transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or operation flowcharts, etc., 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., as mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts, etc., disclosed 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 transmit and receive wireless signals. For example, one or more processors (102, 202) may control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be connected to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this disclosure through one or more antennas (108, 208). In this disclosure, one or more antennas may be a plurality of physical antennas or a plurality of logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert the received wireless signal / channel, etc. from an RF band signal to a baseband signal in order to process the received user data, control information, wireless signal / channel, etc. using one or more processors (102, 202).One or more transceivers (106, 206) can convert user data, control information, wireless signals / channels, etc. processed using one or more processors (102, 202) from baseband signals to RF band signals. To this end, one or more transceivers (106, 206) may include (analog) oscillators and / or filters.

[0041] For example, one of the STAs (100, 200) may perform the intended operation of an AP, and the other of the STAs (100, 200) may perform the intended operation of a non-AP STA. For example, the transceiver (106, 206) of FIG. 1 may perform the operation of transmitting and receiving signals (e.g., packets or PPDU (Physical Layer Protocol Data Unit) according to IEEE 802.11a / b / g / n / ac / ax / be / bn, etc.). Additionally, the operation of generating transmission and reception signals or performing data processing or calculations in advance for transmission and reception signals by various STAs in the present disclosure may be performed by the processor (102, 202) of FIG. 1. For example, an example of an operation to generate a transmission and reception signal or to perform data processing or operations in advance for a transmission and reception signal may include: 1) an operation to determine / acquire / configure / operate / decode / encode bit information of fields (SIG (signal), STF (short training field), LTF (long training field), Data, etc.) included in the PPDU; 2) an operation to determine / configure / acquire time resources or frequency resources (e.g., subcarrier resources) used for fields (SIG, STF, LTF, Data, etc.) included in the PPDU; 3) an operation to determine / configure / acquire specific sequences (e.g., pilot sequence, STF / LTF sequence, extra sequence applied to SIG) used for fields (SIG, STF, LTF, Data, etc.) included in the PPDU; 4) power control operations and / or power saving operations applied to the STA; and 5) operations related to determining / acquiring / configuring / operating / decoding / encoding of an ACK signal. In addition, in the following example, various information (e.g., information related to fields, subfields, control fields, parameters, power, etc.) used by various STAs for determining / acquiring / configuring / calculating / decoding / encoding of transmission and reception signals can be stored in the memory (104, 204) of FIG. 1.

[0042] In the following, the downlink (DL) refers to a link for communication from an AP STA to a non-AP STA, and downlink PPDUs, packets, signals, etc., can be transmitted and received through the downlink. In downlink communication, the transmitter may be part of the AP STA, and the receiver may be part of the non-AP STA. The uplink (UL) refers to a link for communication from a non-AP STA to an AP STA, and uplink PPDUs, packets, signals, etc., can be transmitted and received through the uplink. In uplink communication, the transmitter may be part of the non-AP STA, and the receiver may be part of the AP STA.

[0043] FIG. 2 is a drawing showing an exemplary structure of a wireless LAN system to which the present disclosure can be applied.

[0044] The structure of a wireless LAN system can be composed of multiple components. Through the interaction of multiple components, a wireless LAN that supports STA mobility transparent to the upper layer can be provided. A Basic Service Set (BSS) corresponds to the basic building block of a wireless LAN. Figure 2 exemplarily illustrates the existence of two BSSs (BSS1 and BSS2) and the inclusion of two STAs as members of each BSS (STA1 and STA2 are included in BSS1, and STA3 and STA4 are included in BSS2). In Figure 2, the ellipse representing the BSS can also be understood as representing the coverage area where the STAs included in the corresponding BSS maintain communication. This area can be referred to as a Basic Service Area (BSA). If a STA moves outside the BSA, it becomes unable to communicate directly with other STAs within that BSA.

[0045] Excluding the DS illustrated in Fig. 2, the most basic type of BSS in a wireless LAN is the Independent BSS (IBSS). For example, an IBSS can have a minimal form consisting of only two STAs. For instance, assuming other components are omitted, a BSS1 composed of only STA1 and STA2, or a BSS2 composed of only STA3 and STA4, can each be considered a representative example of an IBSS. Such a configuration is possible when the STAs can communicate directly without an AP. Furthermore, this type of wireless LAN is not configured through pre-planning but can be configured when a LAN is needed, and this can be referred to as an ad-hoc network. Since an IBSS does not include an AP, there is no centralized management entity. In other words, in an IBSS, STAs are managed in a distributed manner. In IBSS, all STAs can be mobile STAs, and since connections to distributed systems (DS) are not allowed, they form a self-contained network.

[0046] The membership of an STA in a BSS can be dynamically changed by the STA being turned on or off, or by the STA entering or leaving the BSS area. To become a member of a BSS, an STA can join the BSS using a synchronization process. To access all services of the BSS infrastructure, an STA must be associated with the BSS. This association can be configured dynamically and may include the use of a Distribution System Service (DSS).

[0047] In a wireless LAN, the direct STA-to-STA distance may be limited by PHY performance. In some cases, this distance limit may be sufficient, but in others, communication between STAs over longer distances may be required. To support extended coverage, a distributed system (DS) may be configured.

[0048] DS refers to a structure in which BSSs are interconnected. Specifically, as shown in FIG. 2, a BSS may exist as a component in 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). In this regard, the Wireless Medium (WM) and the DSM can be logically distinguished. Each logical medium is used for a different purpose and is utilized by different components. These media are not limited to being identical or different. The flexibility of the wireless LAN structure (DS structure or other network structure) can be explained by the fact that multiple media are logically distinct in this way. That is, the wireless LAN structure can be implemented in various ways, and the corresponding wireless LAN structure can be specified independently by the physical characteristics of each implementation.

[0049] DS can support mobile devices by providing seamless integration of multiple BSSs and providing logical services necessary for handling addresses to destinations. Additionally, DS may include a component called a portal that acts as a bridge for connecting the wireless LAN with another network (e.g., IEEE 802.X).

[0050] An AP refers to an entity that enables access to the DS via the WM for combined non-AP STAs and also possesses the functionality of an STA. Data movement between the BSS and the DS can be performed through the AP. For example, STA2 and STA3 shown in FIG. 2 possess the functionality of an STA and provide the ability for combined non-AP STAs (STA1 and STA4) to access the DS. Furthermore, since all APs fundamentally correspond to STAs, all APs are addressable entities. The address used by the AP for communication on the WM and the address used by the AP for communication on the DSM do not necessarily have to be the same. A BSS composed of an AP and one or more STAs can be referred to as an infrastructure BSS.

[0051] Data transmitted from one of the STA(s) coupled to the AP to the STA address of the AP can always be received at an uncontrolled port and processed by an IEEE 802.1X port access entity. Additionally, if the controlled port is authenticated, the transmitted data (or frame) can be forwarded to the DS.

[0052] In addition to the structure of the aforementioned DS, an Extended Service Set (ESS) may be configured to provide wider coverage.

[0053] An ESS refers to a network of arbitrary size and complexity composed of DSs and BSSs. An ESS can correspond to a set of BSSs connected to a single DS. However, an ESS does not contain a DS. An ESS network is characterized by appearing as an IBSS at the Logical Link Control (LLC) layer. STAs included in an ESS can communicate with each other, and mobile STAs can move from one BSS to another (within the same ESS) transparently to the LLC. APs included in a single ESS can have the same Service Set Identification (SSID). The SSID is distinct from the BSSID, which is the identifier for the BSS.

[0054] In wireless LAN systems, no assumptions are made regarding the relative physical locations of BSSs, and all of the following forms are possible. BSSs may partially overlap, which is a form commonly used to provide continuous coverage. Additionally, BSSs may not be physically connected, and logically, there is no limit to the distance between BSSs. Furthermore, BSSs may be located in the same physical location, which can be used to provide redundancy. Also, one (or more) IBSS or ESS networks may physically exist in the same space as one (or more) ESS networks. This may apply to ESS network forms such as when an ad-hoc network operates at a location where an ESS network exists, when wireless networks that physically overlap are configured by different organizations, or when two or more different access and security policies are required at the same location.

[0055] FIG. 3 is a diagram illustrating a link setup process to which the present disclosure can be applied.

[0056] In order for an STA to set up a link and transmit and receive data on a network, it must first discover the network, perform authentication, establish an association, and go through authentication procedures for security. The link setup process can also be referred to as the session initiation process or the session setup process. Additionally, the processes of discovery, authentication, association, and security setup in the link setup process can be collectively referred to as the association process.

[0057] In step S310, the STA may perform a network discovery operation. The network discovery operation may include the STA's scanning operation. That is, in order for the STA to access a network, it must find a network it can join. Before joining a wireless network, the STA must identify a compatible network, and the process of identifying networks existing in a specific area is called scanning.

[0058] Scanning methods include active scanning and passive scanning. Figure 3 illustrates a network discovery operation that includes an active scanning process as an example. In active scanning, the STA performing the scanning moves between channels to search for nearby APs, transmits a probe request frame, and waits for a response. The responder transmits a probe response frame as a response to the probe request frame to the STA that transmitted the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame from the BSS of the channel being scanned. In a BSS, the AP becomes the responder because it transmits the beacon frame; however, in an IBSS, the responder is not constant because STAs within the IBSS take turns transmitting the beacon frame. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 can store BSS-related information included in the received probe response frame and move to the next channel (e.g., channel 2) to perform scanning in the same way (i.e., transmit and receive probe request / response on channel 2).

[0059] Although not illustrated in FIG. 3, the scanning operation may be performed using a passive scanning method. In passive scanning, the STA performing the scanning waits for a beacon frame while switching between channels. A beacon frame is one of the management frames defined in IEEE 802.11, which is periodically transmitted to announce the presence of a wireless network and to allow the scanning STA to find the wireless network and join it. In a BSS, the AP performs the role of periodically transmitting beacon frames, and in an IBSS, the STAs within the IBSS take turns transmitting beacon frames. When the scanning STA receives a beacon frame, it stores the information about the BSS included in the beacon frame and records the beacon frame information in each channel while moving to another channel. The STA that receives the beacon frame stores the BSS-related information included in the received beacon frame, moves to the next channel, and can perform scanning in the next channel in the same way. When comparing active scanning and passive scanning, active scanning has the advantage of lower delay and power consumption than passive scanning.

[0060] After the STA discovers the network, an authentication process may be performed in step S320. This authentication process may be referred to as the first authentication process to clearly distinguish it from the security setup operation in step S340 described later.

[0061] The authentication process involves the STA sending an authentication request frame to the AP, and the AP sending an authentication response frame to the STA in response. The authentication frame used in the authentication request / response corresponds to a management frame.

[0062] The authentication frame may include information regarding the authentication algorithm number, authentication transaction sequence number, status code, challenge text, Robust Security Network (RSN), Finite Cyclic Group, etc. These are some examples of information that may be included in the authentication request / response frame, and they may be replaced with other information or additional information may be included.

[0063] The STA can send an authentication request frame to the AP. Based on the information contained in the received authentication request frame, the AP can determine whether to allow authentication for the STA. The AP can provide the result of the authentication process to the STA through an authentication response frame.

[0064] After the STA is successfully authenticated, the association process can be performed in step S330. The association process includes the STA transmitting an association request frame to the AP, and in response, the AP transmitting an association response frame to the STA.

[0065] For example, the association request frame may include information regarding various capabilities, beacon listen interval, service set identifier (SSID), supported rates, supported channels, RSN, mobility domain, supported operating classes, Traffic Indication Map Broadcast request, interworking service capabilities, etc. For example, the association response frame may include information regarding various capabilities, status code, Association ID (AID), supported rates, Enhanced Distributed Channel Access (EDCA) parameter set, Received Channel Power Indicator (RCPI), Received Signal to Noise Indicator (RSNI), mobility domain, timeout interval (e.g., association comeback time), overlapping BSS scan parameters, TIM broadcast response, Quality of Service (QoS) map, etc. These are some examples of information that may be included in a combined request / response frame, and may be replaced with other information or additional information may be included.

[0066] After the STA is successfully joined to the network, a security setup process can be performed in step S340. The security setup process in step S340 may be described as an authentication process through RSNA (Robust Security Network Association) requests / responses, and the authentication process in step S320 may be referred to as the first authentication process, and the security setup process in step S340 may simply be referred to as the authentication process.

[0067] The security setup process of step S340 may include, for example, a private key setup process through a 4-way handshake via an EAPOL (Extensible Authentication Protocol over LAN) frame. Additionally, the security setup process may be performed according to a security method not defined in the IEEE 802.11 standard.

[0068] FIG. 4 is a drawing illustrating a backoff process to which the present disclosure may be applied.

[0069] In wireless LAN systems, the basic access mechanism for MAC (Medium Access Control) is the CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) mechanism. The CSMA / CA mechanism is also known as the Distributed Coordination Function (DCF) of IEEE 802.11 MAC, and it basically employs a "listen before talk" access mechanism. According to this type of access mechanism, the AP and / or STA may perform Clear Channel Assessment (CCA) to sense the wireless channel or medium for a predetermined time interval (e.g., DIFS (DCF Inter-Frame Space)) before starting transmission. If the sensing result determines that the medium is in an idle status, it starts transmitting a frame through that medium. On the other hand, if the medium is detected to be occupied or busy, the AP and / or STA may not start its own transmission but wait by setting a delay period for medium access (e.g., a random backoff period) before attempting to transmit a frame. By applying a random backoff period, multiple STAs are expected to attempt to transmit frames after waiting for different periods of time, thereby minimizing collisions.

[0070] In addition, the IEEE 802.11 MAC protocol provides a Hybrid Coordination Function (HCF). The HCF is based on the aforementioned Point Coordination Function (PCF). The PCF is a polling-based synchronous access method that periodically polls to ensure all receiving APs and / or STAs can receive data frames. Furthermore, the HCF includes Enhanced Distributed Channel Access (EDCA) and Controlled Channel Access (HCCA). EDCA is a contention-based access method for a provider to offer data frames to multiple users, while HCCA uses a non-contention-based channel access method utilizing a polling mechanism. Additionally, the HCF includes a media access mechanism to improve the Quality of Service (QoS) of the wireless LAN and can transmit QoS data during both the Contention Period (CP) and the Contention-Free Period (CFP).

[0071] Referring to FIG. 4, the operation based on the random backoff period is described. When a medium in an occupied / busy state changes to an idle state, multiple STAs may attempt to transmit data (or frames). As a measure to minimize collisions, each STA may select a random backoff count and attempt transmission after waiting for the corresponding slot time. The random backoff count has a pseudo-random integer value and can be determined as one of the values ​​in the range from 0 to CW. Here, CW is the Contention Window parameter value. The CW parameter is given an initial value of CWmin, but in the case of transmission failure (e.g., failure to receive an ACK for a transmitted frame), it may take a value twice that amount. When the CW parameter value becomes CWmax, data transmission may be attempted while maintaining the CWmax value until data transmission is successful; if data transmission is successful, it is reset to the CWmin value. The values ​​of CW, CWmin, and CWmax are 2 n It is desirable to set it to -1 (n=0, 1, 2, ...).

[0072] When the random backoff process begins, the STA continues to monitor the media while counting down the backoff slots according to the determined backoff count value. When the media is monitored as occupied, it stops the countdown and waits, and when the media becomes idle, it resumes the remaining countdown.

[0073] In the example of Fig. 4, when a packet to be transmitted arrives at the MAC of STA3, STA3 confirms that the medium is idle for DIFS and can immediately transmit the frame. The remaining STAs monitor whether the medium is occupied or busy and wait. Meanwhile, data to be transmitted may also arise from each of STA1, STA2, and STA5, and each STA can perform a countdown of the backoff slot according to a random backoff count value selected by each after waiting for DIFS when the medium is monitored to be idle. Assume the case where STA2 selects the smallest backoff count value and STA1 selects the largest backoff count value. That is, this exemplifies a case where, at the point when STA2 finishes the backoff count and starts transmitting the frame, the remaining backoff time of STA5 is shorter than the remaining backoff time of STA1. STA1 and STA5 pause the countdown briefly and wait while STA2 occupies the medium. When STA2's possession ends and the medium becomes idle again, STA1 and STA5 wait for DIFS and then resume the paused backoff count. That is, they can start transmitting a frame after counting down the remaining backoff slots corresponding to the remaining backoff time. Since STA5's remaining backoff time was shorter than STA1's, STA5 starts transmitting the frame. While STA2 is occupying the medium, data to be transmitted may also be generated by STA4. From STA4's perspective, when the medium becomes idle, it waits for DIFS, performs a countdown based on a random backoff count value selected by itself, and can start transmitting a frame. The example in Figure 4 illustrates a case where STA5's remaining backoff time happens to match STA4's random backoff count value; in this case, a collision may occur between STA4 and STA5. If a collision occurs, neither STA4 nor STA5 receives an ACK, resulting in a failure to transmit data.In this case, STA4 and STA5 can double the CW value, select a random backoff count value, and perform a countdown. STA1 waits while the medium is occupied due to transmission by STA4 and STA5, and when the medium becomes idle, it waits for DIFS, and then can start transmitting frames after the remaining backoff time has passed.

[0074] As shown in the example in Fig. 4, a data frame is a frame used for transmitting data that is forwarded to an upper layer, and can be transmitted after a backoff performed after the elapsed time of DIFS from when the medium becomes idle. Additionally, a management frame is a frame used for exchanging management information that is not forwarded to an upper layer, and is transmitted after a backoff performed after the elapsed time of an IFS such as DIFS or PIFS (Point coordination function IFS). Subtypes of management frames include Beacon, Association request / response, re-association request / response, probe request / response, and authentication request / response. A control frame is a frame used to control access to the medium. Subtype frames of control frames include RTS (Request-To-Send), CTS (Clear-To-Send), ACK (Acknowledgment), PS-Poll (Power Save-Poll), Block ACK (BlockAck), Block ACK Request (BlockACKReq), NDP Announcement (null data packet announcement), and Trigger. If a control frame is not an acknowledgment frame of a previous frame, it is transmitted after a backoff performed after the elapsed DIFS; if it is an acknowledgment frame of a previous frame, it is transmitted after the elapsed SIFS (short IFS) without a backoff. The type and subtype of a frame can be identified by the type field and subtype field within the Frame Control (FC) field.

[0075] A QoS (Quality of Service) STA can transmit a frame after backoff, which is performed after the passage of the arbitration IFS (AIFS) for the access category (AC) to which the frame belongs, i.e., AIFS[i] (where i is a value determined by the AC). Here, the frame for which AIFS[i] can be used can be a data frame or a management frame, and can also be a control frame rather than a response frame.

[0076] FIG. 5 is a diagram illustrating a CSMA / CA-based frame transmission operation to which the present disclosure may be applied.

[0077] As previously mentioned, the CSMA / CA mechanism includes virtual carrier sensing in addition to physical carrier sensing, where the STA directly senses the medium. Virtual carrier sensing is intended to mitigate problems that may occur in medium access, such as the hidden node problem. For virtual carrier sensing, the STA's MAC can utilize the Network Allocation Vector (NAV). The NAV is a value that indicates to other STAs the time remaining until the medium becomes available, provided that the STA currently using or authorized to use the medium is using it. Therefore, the value set as the NAV corresponds to the period during which the medium is scheduled to be used by the STA transmitting the frame, and the STA receiving the NAV value is prohibited from accessing the medium during that period. For example, the NAV can be set based on the value of the "duration" field in the frame's MAC header.

[0078] In the example of FIG. 5, it is assumed that STA1 intends to transmit data to STA2, and STA3 is located in a position where it can overhear part or all of the frames transmitted and received between STA1 and STA2.

[0079] In order to reduce the possibility of collisions between multiple STAs in a CSMA / CA-based frame transmission operation, a mechanism utilizing RTS / CTS frames may be applied. In the example of FIG. 5, while STA1 is transmitting, the medium may be determined to be idle based on the carrier sensing result of STA3. That is, STA1 may be a hidden node to STA3. Alternatively, in the example of FIG. 5, while STA2 is transmitting, the medium may be determined to be idle based on the carrier sensing result of STA3. That is, STA2 may be a hidden node to STA3. By exchanging RTS / CTS frames before performing data transmission and reception between STA1 and STA2, it is possible to prevent a STA outside the transmission range of either STA1 or STA2, or a STA outside the carrier sensing range for transmission from STA1 or STA3, from attempting to occupy the channel during data transmission and reception between STA1 and STA2.

[0080] Specifically, STA1 can determine whether the channel is in use through carrier sensing. In terms of physical carrier sensing, STA1 can determine the channel occupancy idle state based on the energy magnitude or signal correlation detected in the channel. Additionally, in terms of virtual carrier sensing, STA1 can determine the channel occupancy state using a NAV (network allocation vector) timer.

[0081] If the channel is idle during DIFS, STA1 can send an RTS frame to STA2 after performing backoff. If STA2 receives the RTS frame, it can send a CTS frame to STA1 as a response to the RTS frame after SIFS.

[0082] If STA3 cannot overhear a CTS frame from STA2 but can overhear an RTS frame from STA1, STA3 can set a NAV timer for the duration of subsequently transmitted frames (e.g., SIFS + CTS frame + SIFS + data frame + SIFS + ACK frame) using the duration information included in the RTS frame. Alternatively, if STA3 cannot overhear an RTS frame from STA1 but can overhear a CTS frame from STA2, STA3 can set a NAV timer for the duration of subsequently transmitted frames (e.g., SIFS + data frame + SIFS + ACK frame) using the duration information included in the CTS frame. That is, if STA3 can overhear one or more of the RTS or CTS frames from one or more of STA1 or STA2, it can set a NAV accordingly. If STA3 receives a new frame before the NAV timer expires, it can update the NAV timer using the duration information contained in the new frame. STA3 does not attempt channel access until the NAV timer expires.

[0083] If STA1 receives a CTS frame from STA2, it may transmit a data frame to STA2 after SIFS from the time the reception of the CTS frame is completed. If STA2 successfully receives the data frame, it may transmit an ACK frame to STA1 as an acknowledgment to the data frame after SIFS. STA3 may determine whether the channel is in use through carrier sensing when the NAV timer expires. If STA3 determines that the channel is not in use by another terminal during DIFS from the time the NAV timer expires, it may attempt channel access after a contention window (CW) based on random backoff has passed.

[0084] FIG. 6 is a drawing for illustrating an example of a frame structure used in a wireless LAN system to which the present disclosure may be applied.

[0085] Based on instructions or primitives (meaning a set of instructions or parameters) from the MAC layer, the PHY layer can prepare the MPDU (MAC PDU) to be transmitted. For example, upon receiving an instruction from the MAC layer requesting the start of transmission, the PHY layer switches to transmit mode and can construct the information provided by the MAC layer (e.g., data) into a frame for transmission. Additionally, if the PHY layer detects a valid preamble of a received frame, it monitors the preamble header and sends an instruction to the MAC layer indicating the start of reception.

[0086] As such, information transmission and reception in wireless LAN systems are carried out in the form of frames, and for this purpose, the Physical Layer Protocol Data Unit (PPDU) format is defined.

[0087] A basic PPDU may include a Short Training Field (STF), a Long Training Field (LTF), a Signal (SIGNAL) field, and a Data field. The most basic (e.g., the non-HT (High Throughput)) PPDU format illustrated in FIG. 7 may consist only of Legacy-STF (Legacy-STF), Legacy-LTF (Legacy-LTF), Legacy-SIG (Legacy-SIG) fields and a 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 other types of) RL-SIG, U-SIG, non-legacy SIG fields, non-legacy STF, non-legacy LTF, (i.e., xx-SIG, xx-STF, xx-LTF (e.g., xx is HT, VHT, HE, EHT, etc.)) may be included between the L-SIG field and the data field. More specific details will be described later with reference to FIG. 7.

[0088] STF is a signal for signal detection, AGC (Automatic Gain Control), diversity selection, and precise time synchronization, while LTF is a signal for channel estimation and frequency error estimation. STF and LTF can be considered signals for synchronization and channel estimation in the OFDM physical layer.

[0089] The SIG field may contain various information related to the transmission and reception of the PPDU. For example, the L-SIG field consists of 24 bits and may include a 4-bit Rate field, a 1-bit Reserved bit, a 12-bit Length field, a 1-bit Parity field, and a 6-bit Tail field. The RATE field may contain information regarding the modulation and coding rates of the data. For example, the 12-bit Length field may contain information regarding the length or time duration of the PPDU. For example, the value of the 12-bit Length field may be determined based on the type of the PPDU. For example, for 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.

[0090] The data field may include a SERVICE field, a PSDU (Physical layer Service Data Unit), and PPDU TAIL bits, and may also include padding bits if necessary. Some bits of the SERVICE field may be used for synchronization of the descrambler at the receiver. The PSDU corresponds to a MAC PDU defined at the MAC layer and may contain data generated or used by the upper layer. The PPDU TAIL bits may be used to return the encoder to a 0 state. Padding bits may be used to adjust the length of the data field to a predetermined unit.

[0091] A 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 is composed of a MAC PDU and can be transmitted or received through the PSDU of the data portion in the PPDU format.

[0092] The MAC header includes a Frame Control field, a Duration / ID field, an Address field, etc. The Frame Control field may contain control information necessary for transmitting or receiving frames. The Duration / ID field may be set as the time for transmitting the corresponding frame. Address subfields may indicate the frame's receiver address, transmitter address, destination address, and source address, and some address subfields may be omitted. Specific details regarding each subfield of the MAC header, including Sequence Control, QoS Control, and HT Control subfields, can be found in the IEEE 802.11 standard document.

[0093] The Null-Data PPDU (NDP) format refers to a PPDU format that does not include a data field. In other words, NDP is a frame format that includes the PPDU preamble (i.e., L-STF, L-LTF, L-SIG fields, and additionally, non-legacy SIG, non-legacy STF, and non-legacy LTF if present) from a standard PPDU format, but excludes the remaining parts (i.e., the data field).

[0094] FIG. 7 is a drawing illustrating examples of PPDUs defined in the IEEE 802.11 standard to which the present disclosure may be applied.

[0095] Various forms of PPDU have been used in standards such as IEEE 802.11a / g / n / ac / ax. The basic PPDU format (IEEE 802.11a / g) includes L-LTF, L-STF, L-SIG, and Data fields. The basic PPDU format may also be referred to as the non-HT PPDU format (Fig. 7(a)).

[0096] The HT PPDU format (IEEE 802.11n) additionally includes HT-SIG, HT-STF, and HT-LFT(s) fields in addition to the basic PPDU format. The HT PPDU format illustrated in FIG. 7(b) may be referred to as the HT-mixed format. Additionally, an HT-greenfield format PPDU may be defined, which corresponds to a format consisting of HT-GF-STF, HT-LTF1, HT-SIG, one or more HT-LTFs, and a Data field, without including L-STF, L-LTF, and L-SIG (not shown).

[0097] An example of the VHT PPDU format (IEEE 802.11ac) includes the VHT SIG-A, VHT-STF, VHT-LTF, and VHT-SIG-B fields in addition to the basic PPDU format (Fig. 7(c)).

[0098] An example of the HE PPDU format (IEEE 802.11ax) includes the RL-SIG (Repeated L-SIG), HE-SIG-A, HE-SIG-B, HE-STF, HE-LTF(s), and PE (Packet Extension) fields in addition to the basic PPDU format (Fig. 7(d)). Depending on the specific examples of the HE PPDU format, some fields may be excluded or their lengths may vary. For example, the HE-SIG-B field is included in the HE PPDU format for multiple users (MU), but is not included in the HE PPDU format for single users (SU). Additionally, the HE trigger-based (TB) PPDU format does not include HE-SIG-B, and the length of the HE-STF field may vary to 8 µs. The HE ER (Extended Range) SU PPDU format does not include the HE-SIG-B field, and the length of the HE-SIG-A field may vary to 16 µs. For example, RL-SIG can be configured identically to L-SIG. Based on the presence of RL-SIG, the receiving STA can determine that the received PPDU is a HE PPDU or the EHT PPDU described later.

[0099] The EHT PPDU format may include the EHT MU (multi-user) of FIG. 7(e) and the EHT TB (trigger-based) PPDU of FIG. 7(f). The EHT PPDU format is similar to the HE PPDU format in that it includes RL-SIG following L-SIG, but it may include U (universal)-SIG, EHT-SIG, EHT-STF, and EHT-LTF following RL-SIG.

[0100] The EHT MU PPDU of FIG. 7(e) corresponds to a PPDU that carries one or more data (or PSDU) for one or more users. That is, the EHT MU PPDU can be used for both SU transmission and MU transmission. For example, the EHT MU PPDU can correspond to a PPDU for one receiving STA or multiple receiving STAs.

[0101] The EHT-SIG is omitted in the EHT TB PPDU of FIG. 7(f) compared to the EHT MU PPDU. A STA that receives a trigger for UL MU transmission (e.g., a trigger frame or TRS (triggered response scheduling)) can perform UL transmission based on the EHT TB PPDU format.

[0102] The L-STF, L-LTF, L-SIG, RL-SIG, U-SIG (Universal SIGNAL), and EHT-SIG fields can be encoded and modulated so that demodulation and decoding can be attempted even on legacy STAs, and mapped based on a defined subcarrier frequency interval (e.g., 312.5 kHz). These can be referred to as pre-EHT modulated fields. Next, the EHT-STF, EHT-LTF, Data, and PE fields can be encoded and modulated so that they can be demodulated and decoded by a STA that has successfully decoded a non-legacy SIG (e.g., U-SIG and / or EHT-SIG) to obtain the information contained in the corresponding fields, and mapped based on a defined subcarrier frequency interval (e.g., 78.125 kHz). These can be referred to as EHT modulated fields.

[0103] Similarly, in the HE PPDU format, the L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B fields can be referred to as pre-HE modulation fields, and the HE-STF, HE-LTF, Data, and PE fields can be referred to as HE modulation fields. Also, in the VHT PPDU format, the L-STF, L-LTF, L-SIG, and VHT-SIG-A fields can be referred to as pre-VHT modulation fields, and the VHT STF, VHT-LTF, VHT-SIG-B, and Data fields can be referred to as VHT modulation fields.

[0104] The U-SIG included in the EHT PPDU format of FIG. 7 can be constructed based on, for example, two symbols (e.g., two consecutive OFDM symbols). Each symbol for the U-SIG (e.g., OFDM symbol) can have a duration of 4 µs, and the U-SIG can have a total duration of 8 µs. Each symbol of the U-SIG can be used to transmit 26 bits of information. For example, each symbol of the U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0105] U-SIGs can be configured in 20 MHz units. For example, if an 80 MHz PPDU is configured, the same U-SIG can be duplicated in 20 MHz units. That is, four identical U-SIGs can be included within an 80 MHz PPDU. If the bandwidth exceeds 80 MHz, for example, for a 160 MHz PPDU, the U-SIG of the first 80 MHz unit and the U-SIG of the second 80 MHz unit may be different.

[0106] For example, A number of uncoded bits may be transmitted through U-SIG, and the first symbol of U-SIG (e.g., U-SIG-1 symbol) transmits the first X bits of the total A bit information, and the second symbol of U-SIG (e.g., U-SIG-2 symbol) transmits the remaining Y bits of the total A bit information. The A bit information (e.g., 52 uncoded bits) may include a CRC field (e.g., a field of 4 bits) and a tail field (e.g., a field of 6 bits). The tail field may be used to terminate the trellis of the convolution decoder and may be set to, for example, 0.

[0107] A bit information transmitted by U-SIG can be divided into version-independent bits and version-dependent bits. For example, U-SIG may be included in a new PPDU format not shown in FIG. 7 (e.g., UHR PPDU format), and in the format of the U-SIG field included in the EHT PPDU format and the format of the U-SIG field included in the UHR PPDU format, the version-independent bits may be the same, and some or all of the version-dependent bits may be different.

[0108] For example, the size of the version-independent bits of U-SIG may be fixed or variable. The version-independent bits may be assigned only to U-SIG-1 symbols or to both U-SIG-1 and U-SIG-2 symbols. The version-independent bits and version-dependent bits may be referred to by various names, such as the first control bit and the second control bit.

[0109] For example, the version-independent bits of U-SIG may include a 3-bit physical layer version identifier (PHY version identifier), and this information may indicate the PHY version of the transmitted / received PPDU (e.g., EHT, UHR, etc.). The version-independent bits of U-SIG may include a 1-bit UL / DL flag field. The first value of the 1-bit UL / DL flag field relates to UL communication, and the second value of the UL / DL flag field relates to DL communication. The version-independent bits of U-SIG may include information regarding the length of the TXOP (transmission opportunity) and information regarding the BSS color ID.

[0110] For example, the version-dependent bits of U-SIG may contain information that directly or indirectly indicates the type of PPDU (e.g., SU PPDU, MU PPDU, TB PPDU, etc.).

[0111] Information necessary for PPDU transmission and reception may be included in the U-SIG. For example, the U-SIG may further include information regarding bandwidth, information regarding MCS techniques applied to non-legacy SIGs (e.g., EHT-SIG or UHR-SIG, etc.), information indicating whether DCM (dual carrier modulation) techniques (e.g., techniques to achieve an effect similar to frequency diversity by reusing the same signal on two subcarriers) are applied to non-legacy SIGs, information regarding the number of symbols used for non-legacy SIGs, and information regarding whether non-legacy SIGs are generated across the entire band.

[0112] Some of the information required for PPDU transmission and reception may be included in U-SIG and / or non-legacy SIGs (e.g., EHT-SIG or UHR-SIG, etc.). For example, information regarding the type of non-legacy LTF / STF (e.g., EHT-LTF / EHT-STF or UHR-LTF / UHR-STF, etc.), information regarding the length of non-legacy LTF and cyclic prefix (CP) length, information regarding guard interval (GI) applied to non-legacy LTF, information regarding preamble puncturing applicable to PPDU, information regarding resource unit (RU) allocation, etc., may be included only in U-SIG, may be included only in non-legacy SIG, or may be indicated by a combination of information included in U-SIG and information included in non-legacy SIG.

[0113] Preamble puncturing may refer to the transmission of a PPDU in which a signal is not present in one or more frequency units within the PPDU bandwidth. For example, the size of the frequency unit (or the resolution of 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 larger.

[0114] In the example of FIG. 7, non-legacy SIGs such as HE-SIG-B and EHT-SIG may include control information for the receiving STA. A non-legacy SIG may be transmitted through at least one symbol, and one symbol may have a length of 4 µs. Information regarding the number of symbols used for EHT-SIG may be included in the previous SIG (e.g., HE-SIG-A, U-SIG, etc.).

[0115] Non-legacy SIGs, such as HE-SIG-B and EHT-SIG, may include common fields and user-specific fields. Common fields and user-specific fields may be coded individually.

[0116] In some cases, the common field may be omitted. For example, in a compression mode where non-OFDMA (orthogonal frequency multiple access) is applied, the common field may be omitted, and multiple STAs may receive PPDUs (e.g., the data field of the PPDU) over the same frequency band. In a non-compression mode where OFDMA is applied, multiple users may receive PPDUs (e.g., the data field of the PPDU) over different frequency bands.

[0117] The number of user-specific fields can be determined based on the number of users. A single user block field can contain up to two user fields. Each user field may be related to MU-MIMO allocation or non-MU-MIMO allocation.

[0118] The common field may include CRC bits and Tail bits, the length of the CRC bits may be determined to be 4 bits, and 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 regarding the location of the RU to which a plurality of users (i.e., a plurality of receiving STAs) are allocated.

[0119] An RU may include multiple subcarriers (or tones). An RU may be used when transmitting signals to multiple STAs based on the OFDMA technique. Additionally, an RU may be defined when transmitting signals to a single STA. Resources may be allocated on an RU basis for non-legacy STF, non-legacy LTF, and Data fields.

[0120] Applicable RU sizes can be defined according to the PPDU bandwidth. RUs may be defined identically or differently for the applicable PPDU format (e.g., HE PPDU, EHT PPDU, UHR PPDU, etc.). For example, in the case of an 80 MHz PPDU, the RU placement for HE PPDU and EHT PPDU may differ. The applicable RU sizes, number of RUs, RU locations, DC (direct current) subcarrier locations and numbers, null subcarrier locations and numbers, and guard subcarrier locations and numbers for each PPDU bandwidth can be referred to as a tone-plan. For example, a tone-plan for a wide bandwidth may be defined as a multiple repetition of a tone-plan for a low bandwidth.

[0121] RUs of various sizes can be defined as 26-ton RUs, 52-ton RUs, 106-ton RUs, 242-ton RUs, 484-ton RUs, 996-ton RUs, 2x996-ton RUs, 4x996-ton RUs, etc. An MRU (multiple RU) is distinguished from multiple individual RUs and corresponds to a group of subcarriers composed of multiple RUs. For example, one MRU can be defined as 52+26-tons, 106+26-tons, 484+242-tons, 996+484-tons, 996+484+242-tons, 2x996+484-tons, 3x996-tons, or 3x996+484-tons. In addition, multiple RUs constituting a single MRU may be continuous or non-continuous in the frequency domain.

[0122] The specific size of the RU may be reduced or expanded. Accordingly, the specific size of each RU (i.e., the number of corresponding tones) in this disclosure is not limited and is exemplary. Additionally, within a given bandwidth (e.g., 20, 40, 80, 160, 320 MHz, ...) in this disclosure, the number of RUs may vary depending on the RU size.

[0123] The names of the respective fields in the PPDU formats of FIG. 7 are exemplary and the scope of the present disclosure is not limited by such names. Furthermore, the examples of the present disclosure may be applied not only to the PPDU formats exemplified in FIG. 7, but also to new PPDU formats based on the PPDU formats of FIG. 7 in which some fields are excluded and / or some fields are added.

[0124] Multiple Access Point (MAP) Operation

[0125] Examples of the present disclosure regarding multiple access point (MAP) operations are described below.

[0126] MAP operation can be defined as the operation between a master AP (or sharing AP) and a slave AP (or shared AP).

[0127] The master AP plays the role of initiating and controlling MAP operations for transmission and reception between multiple APs. The master AP groups slave APs and manages links with slave APs to enable information sharing among them. The master AP manages information about the BSS configured by the slave APs and information about the STAs that have formed an association with the BSS.

[0128] A slave AP forms a pair with a master AP and can share control information, management information, and data traffic. The slave AP performs the same basic functions as an AP, such as establishing a BSS in a wireless LAN.

[0129] In MAP operation, the STA can form a BSS by combining with a slave AP or a master AP.

[0130] In a MAP environment, the master AP and slave AP can perform direct transmission and reception with each other. The master AP and STA may not be able to perform direct transmission and reception with each other. A slave AP (for example, a slave AP coupled with a STA) can perform direct transmission and reception with the STA. One of the slave APs can become the master AP.

[0131] MAP operation is a technique in which one or more APs transmit and receive information to one or more STAs. For example, techniques such as C-TDMA (coordinated-time division multiple access), which divides allocation between APs along the time axis; C-OFDMA (coordinated-orthogonal frequency division multiple access), which divides along the frequency axis; and C-SR (coordinated-spatial reuse), which utilizes spatial reuse, can be applied for MAP operation. Alternatively, MAP operation may also apply coordinated beamforming (C-BF) or joint beamforming techniques, which perform simultaneous transmission and reception in cooperation.

[0132] FIG. 8 is a diagram illustrating various transmission and reception techniques in a MAP environment to which the present disclosure can be applied.

[0133] As with the existing method, the transmission performed by a BSS AP to a BSS STA can be referred to as STX (single transmission). In STX, there is a problem where the transmission and reception performance for users / STAs located at the cell edge is degraded due to interference with adjacent APs. For example, as shown in Fig. 8(a), if AP1 and AP2 perform transmissions to STA1 and STA2 respectively at the same time in the same frequency band, a collision may occur on the wireless medium.

[0134] In MAP techniques, performance can be improved by reducing inter-symbol interference (ISI) through cooperation among neighboring APs or by performing joint transmissions. For example, in the C-OFDMA method of FIG. 8(b), interference can be avoided by AP1 transmitting to STA1 in the first bandwidth and AP2 transmitting to STA2 in the second bandwidth at the same time. The example in FIG. 8(c) illustrates a cooperative beamforming or nulling technique in which AP1 nulls the interference affecting AP2 and / or STA2 while transmitting to STA1, and AP2 nulls the interference affecting AP1 and / or STA1 while transmitting to STA2. FIG. 8(d) illustrates an AP selection method in which the AP with the best channel conditions among adjacent APs performs the transmission. As shown in the example of Fig. 8(e), joint transmission (JTX) or joint reception (JRX) in which multiple APs cooperate to transmit or receive simultaneously may be applied, and furthermore, joint MU-MIMO may be supported.

[0135] In the examples of the present disclosure, multiple AP operations are assumed to be performed as follows.

[0136] Step 1: Distribute resource areas to each AP via trigger frames from the master AP (i.e., AP-to-AP trigger frames, or master trigger frames).

[0137] Step 2: Each AP performs DL (i.e., from AP to STA) data transmission within its allocated resource area, or transmits a trigger frame (i.e., AP-to-STA trigger frame) for UL (i.e., from STA to AP) data transmission within its allocated resource area.

[0138] Step 3: The STA transmits a response to the DL data or transmits via UL data (e.g., TB PPDU).

[0139] Various PPDU transmissions or receptions

[0140] In a wireless LAN system, a technique in which multiple APs coordinate to transmit PPDUs may be supported. For example, two APs may participate in Co-SR (coordinated-spatial reuse) transmission and Co-BF (coordinated-beamforming) transmission. When Co-SR is applied, multiple APs can minimize mutual interference by coordinating the transmission power of their respective PPDU transmissions, and when Co-BF is applied, multiple APs can eliminate mutual interference through nulling techniques in their respective PPDU transmissions. This disclosure describes PPDU formats and signaling schemes that can be used in Co-SR transmission or Co-BF transmission. For example, a transmitting AP can set the information included in the PPDU fields to a specific value, and a receiving STA that checks / acquires the value of such PPDU field can successfully decode the PPDU(s) based on Co-SR / Co-BF.

[0141] Additionally, an enhanced long range (ELR) PPDU may be supported to improve coverage in a wireless LAN system. The present disclosure describes the format and signaling method of an ELR PPDU. For example, a transmitting STA may set the information included in the fields of an ELR PPDU to a specific value, and based on this, a receiving STA (or AP) may successfully decode the ELR PPDU.

[0142] FIG. 9 is a drawing showing an example of the operation of a first AP according to the present disclosure.

[0143] In step S910, the first AP can generate a first PPDU (physical layer protocol data unit) containing a U-SIG (universal-signal) field and an additional SIG field.

[0144] In step S920, the first AP can transmit the first PPDU to the station (STA).

[0145] In some examples, when the first PPDU is an UHR (ultra-high reliability) MU (multi-user) PPDU and an additional SIG field is a UHR-SIG field, the following behavior may be applied.

[0146] For example, the U-SIG field may include the UL / DL (uplink / downlink) field and the PPDU type and compression mode field.

[0147] For example, for a Co-SR transmission or Co-BF transmission involving the first AP and the second AP, the spatial reuse subfield included in the UHR-SIG field can be set to a value of 15, corresponding to PSR (parameterized spatial reuse) prohibited.

[0148] In the present disclosure, PSR can be described as an operation that allows a STA to perform its own transmission on the same resource as the frame when the frame received from the OBSS satisfies a predetermined condition (e.g., a power threshold based on parameters, etc.), by determining that the interference effect is minimal.

[0149] For example, regarding Co-SR transmission, the first AP may operate based on a second mode (or mode 2) in which a UHR MU PPDU is transmitted from the first AP and a UHR MU PPDU is transmitted from the second AP.

[0150] For example, if the UL / DL field is set to a value of 0 and the PPDU type and compression mode fields are set to a value of 1, the Co-BF / Co-SR indication field included in the U-SIG field is set to a value of 0 to indicate that it is a DL SU (single-user) Co-SR transmission.

[0151] For example, regarding Co-SR transmission, the first AP may operate based on a first mode (or mode 1) in which a UHR MU PPDU is transmitted from the first AP and an EHT (extremely high throughput) MU PPDU is transmitted from the second AP.

[0152] For example, if the UL / DL field is set to a value of 0 and the PPDU type and compression mode fields are set to a value of 1, the Co-BF / Co-SR indication field included in the U-SIG field can be set to a value of 1.

[0153] For example, the first BSS color (basic service set color) field (or BSS color field) included in U-SIG is the BSS color of the first AP, and the second BSS color field (or BSS color 2 field) included in U-SIG can be set to a value corresponding to validate or disregard.

[0154] In the present disclosure, validation may correspond to information that allows a receiving STA to determine whether to continue receiving the PPDU. For example, validation may be used to prevent a malfunction caused by a misinterpretation of the frame by a STA compatible with the current system that does not support a bit or value that is not currently defined in the system but is modified or defined as a new function in the future. For example, if a specific field within the PPDU is set to a value corresponding to validation, the receiving STA may stop receiving the PPDU and defer the receiving operation for the remaining duration of the PPDU. In this way, the receiving STA may be distinguished from the operation of continuing to receive the PPDU after a field set to validation.

[0155] In some other examples, when the first PPDU is an EHT MU PPDU and an additional SIG field is an EHT-SIG field, the following behavior may be applied.

[0156] For example, regarding Co-SR transmission, the first AP may operate based on a first mode (or mode 1) in which an EHT MU PPDU is transmitted from the first AP and a UHR MU PPDU is transmitted from the second AP, or a first mode (or mode 1) in which an EHT MU PPDU is transmitted from the first AP and another EHT MU PPDU is transmitted from the second AP.

[0157] For example, the UL / DL field can be set to a value of 0 and the PPDU type and compression mode fields can be set to a value of 1 to indicate that it is a DL SU transmission.

[0158] For example, the UL / DL field may be set to a value of 0 and the PPDU type and compression mode fields may be set to a value of 0 to indicate that it is a DL OFDMA (orthogonal frequency division multiple access) transmission. Alternatively, the UL / DL field may be set to a value of 0 and the PPDU type and compression mode fields may be set to a value of 2 to indicate that it is a DL non-OFDMA transmission.

[0159] In the examples described above, the first AP is an AP that initiates Co-SR transmission or Co-BF transmission (e.g., a coordinating AP), and the second AP may be an AP that participates in the Co-SR transmission or Co-BF transmission initiated by the first AP (e.g., a coordinated AP).

[0160] In some other examples, when the first PPDU is a UHR ELR (enhanced long range) PPDU and the additional SIG field is an ELR-SIG field, the following behavior may be applied.

[0161] For example, the PPDU type and compression mode fields included in the U-SIG field can be set to a value of 3.

[0162] For example, the bandwidth field included in the U-SIG field can be set to a value of 0 to indicate that it is 20 MHz. Here, values ​​1 to 7 of the bandwidth field can be defined as validate.

[0163] For example, in the 5 GHz band or 6 GHz band, a value of 0 in the UL / DL field included in the U-SIG field can be defined as validation.

[0164] The method described in the example of FIG. 9 may be performed by the first device (100) of FIG. 1. For example, one or more processors (102) of the first device (100) of FIG. 1 may be configured to generate a first PPDU (e.g., MU PPDU or ELR PPDU) including a U-SIG field and additional SIG fields (e.g., UHR-SIG field or ELR-SIG field or EHT-SIG) and to transmit the first PPDU to the STA through one or more transceivers (106). Furthermore, one or more memories (104) of the first device (100) may store instructions for performing the method described in the example of FIG. 9 or the examples described below when executed by one or more processors (102).

[0165] For example, the processor (102) can set the values ​​of the sub-field(s) of the U-SIG field and additional SIG (e.g., UHR-SIG / ELR-SIG / EHT-SIG) fields according to various PPDU formats and transmission techniques, and generate a PPDU (UHR MU PPDU / UHR ELR PPDU / EHT MU PPDU). The generated PPDU can be transmitted to a second device (200) through one or more transceivers (106).

[0166] FIG. 10 is a drawing showing an example of the operation of an STA according to the present disclosure.

[0167] In step S1010, the STA can receive a first PPDU from the first AP that includes a U-SIG field and an additional SIG field.

[0168] In step S1020, the STA can decode the first PPDU.

[0169] In some examples, an STA may receive a first PPDU (e.g., UHR MU PPDU or EHT MU PPDU) from a first AP, and another STA may receive a second PPDU (e.g., UHR MU PPDU or EHT MU PPDU) from a second AP. The sub-field(s) of the U-SIG field and additional SIG (e.g., UHR-SIG or EHT-SIG) field of the first and second PPDUs may be set to specific values ​​according to various examples of the present disclosure. Accordingly, depending on the Co-SR or Co-BF in which the first and second APs participate, an STA may receive and successfully decode the first PPDU transmitted from the first AP, and another STA may receive and successfully decode the second PPDU transmitted from the second AP.

[0170] In some other examples, the STA may receive a first PPDU (e.g., UHR ELR PPDU) from a first AP. The sub-field(s) of the U-SIG field and additional SIG (e.g., ELR-SIG) field of the first PPDU may be set to specific values ​​according to various examples of the present disclosure. Accordingly, the STA may receive and successfully decode the first PPDU transmitted from the first AP.

[0171] In the example of FIG. 10, the specific descriptions of the various PPDU formats, UL / DL fields, PPDU type and compression mode fields, space reuse subfields, Co-BF / Co-SR indication fields, bandwidth fields, first BSS color fields, second BSS color fields, Co-SR modes, and ELR operations are the same as those in the example of FIG. 9, so redundant descriptions are omitted.

[0172] The method described in the example of FIG. 10 may be performed by the second device (200) of FIG. 1. For example, one or more processors (202) of the second device (200) of FIG. 1 may be configured to receive a first PPDU containing a U-SIG field and an additional SIG field from a first AP through one or more transceivers (206) and to decode the first PPDU. Furthermore, one or more memories (204) of the second device (200) may store instructions for performing the method described in the example of FIG. 10 or the examples described below when executed by one or more processors (202).

[0173] For example, when a PPDU is received from a first device (100) through one or more transceivers (206), one or more processors (202) of a second device (200) may be configured to receive a first PPDU from the first device (100) through one or more transceivers (206), and to check / obtain the values ​​of the sub-field(s) of the U-SIG field and additional SIG (e.g., UHR-SIG / ELR-SIG / EHT-SIG) fields of the first PPDU, and to decode the first PPDU according to various PPDU formats and transmission techniques.

[0174] The examples of FIGS. 9 and 10 may correspond to some of the various examples of the present disclosure. Hereinafter, various examples of the present disclosure including the examples of FIGS. 9 and 10 will be described in more detail.

[0175] Example 1

[0176] FIG. 11 is a diagram showing an example of a frame exchange sequence for Co-SR to which the present disclosure can be applied.

[0177] Multi-AP coordination can operate based on negotiation and agreement among AP1, AP2, and AP3. For example, AP1, AP2, and AP3 can discover each other’s MAPC-related capabilities, negotiate MAPC-related parameters, and finally establish MAPC agreement.

[0178] If necessary, a sounding procedure related to a coordinated transmission method (e.g., Co-SR or Co-BF) between APs that have established MAPC consensus may be performed. Interference between APs may also be measured through the sounding procedure.

[0179] Among the APs that have established MAPC consensus, a polling phase may be performed to inquire about and respond to whether to participate in a specific coordinated transmission. For example, the initial control frame (ICF) may correspond to an invite frame for the coordinated transmission, and the initial response frame (ICR) may correspond to a response frame for the coordinated transmission. Through this process, for example, AP1 and AP2 may decide to perform a coordinated transmission (e.g., Co-SR).

[0180] For example, the ICF may include information about MAPC techniques (e.g., Co-SR, Co-BF, Co-TDMA, etc.), maximum transmit power (e.g., the transmit power of AP1, which can be used to calculate the interference level for the target STA of AP2 (e.g., STA2) induced by AP1).

[0181] For example, the ICR may include information such as a participation indicator (or status code), the version of the target STA (e.g., EHT STA or UHR STA).

[0182] Although not shown in FIG. 11, AP1 can indicate that a transmission coordinated through ICF / ICR exchange will be performed with its associated STA1, and AP2 with its associated STA2.

[0183] A MAPC-based transmission procedure may be initiated by AP1 (e.g., a coordinating AP) transmitting a coordination trigger frame to AP2 (e.g., a coordinated AP). The coordination trigger frame may include information regarding resources (e.g., coordination duration, etc.) for AP2 to perform the coordinated transmission.

[0184] For example, the Co-trigger frame may include information regarding the Co-SR mode (e.g., mode 1 or mode 2), the recommended transmit power (e.g., the transmit power of AP2 may be less than or equal to the recommended transmit power, which can be used to limit the level of interference induced by AP2 for the target STA of AP1), etc.

[0185] Accordingly, AP1 and AP2 can transmit data to STA1 and STA2, respectively, according to a coordinated transmission method (e.g., Co-SR). The PPDU transmitted by each AP, including a data frame, may contain common L-SIG and U-SIG information. For example, the Co-SR PPDU transmitted by AP1 and the Co-SR PPDU transmitted by AP2 during the coordination duration may have a specific PPDU format applied as described below, and the sub-field(s) of the signaling field may be set to specific values.

[0186] FIG. 12 is a drawing showing examples of UHR PPDU formats to which the present disclosure can be applied.

[0187] FIG. 12(a) corresponds to the UHR MU PPDU format, FIG. 12(b) corresponds to the UHR TB PPDU format, and FIG. 12(c) corresponds to the UHR ELR PPDU format.

[0188] In all UHR PPDU formats of FIG. 12, L-STF can be defined as 8 µs (microseconds), L-LTF as 8 µs, L-SIG as 4 µs, RL-SIG as 4 µs, and U-SIG as 8 µs (4 µs per symbol).

[0189] In the UHR MU PPDU format, UHR-SIG can be defined as 4us per symbol, and UHR-STF as 4us.

[0190] In the UHR TB PPDU format, UHR-STF can be defined as 8us.

[0191] In UHR MU PPDU format and UHR TB PPDU format, the UHR-LTF symbol duration can be determined based on GI (guard interval) + LTF size.

[0192] In the UHR ELR PPDU format, the ELR-MARK field can be defined as 8us (4us per symbol), UHR-STF as 4us, UHR-LTF as 16us (8us per symbol), ELR-SIG as 28.8us (14.4us per symbol), and PE (packet extension) as 8us.

[0193] For example, the UHR MU PPDU format may be applied to Co-SR transmission and / or Co-BF transmission.

[0194] The B0-B25 bit positions of the U-SIG-1 part of the U-SIG field in the UHR MU PPDU may include, in order, a PHY version identifier (3 bits), bandwidth (3 bits), UL / DL (1 bit), BSS color (6 bits), TXOP (7 bits), and BSS color 2 (6 bits).

[0195] The B0-B25 bit positions of the U-SIG-2 part of the U-SIG field in the UHR MU PPDU may include, in order, PPDU type and compression mode (2 bits), Co-BF / Co-SR indication (1 bit), punctured channel information (5 bits), validate (1 bit), UHR-SIG MCS (2 bits), number of UHR-SIG symbols (5 bits), CRC (4 bits), and tail (6 bits).

[0196] For example, Co-SR can be applied when the Co-BF / Co-SR indication field is set to 0, in the case of DL (e.g., the UL / DL field is set to 0) and SU transmission (e.g., the PPDU type and compression mode field values ​​are set to 1).

[0197] For example, Co-BF can be applied when the Co-BF / Co-SR indication field is set to 0 in the case of DL (e.g., the UL / DL field is set to 0) and non-OFDMA MU MIMO transmission (e.g., the PPDU type and compression mode field values ​​are set to 2).

[0198] Two modes of Co-SR can be supported in UHR.

[0199] The first mode (or mode 1) may correspond to cases where APs participating in Co-SR transmit UHR MU PPDU and EHT MU PPDU, transmit EHT MU PPDU and UHR MU PPDU, or transmit EHT MU PPDU and EHT MU PPDU.

[0200] Mode 2 (or Mode 2) may apply when all APs participating in Co-SR transmit UHR MU PPDU.

[0201] For example, when Co-SR transmission is performed by multiple APs under Mode 2, all transmit UHR MU PPDUs, and the L-SIG and U-SIG contents of all PPDUs can be set identically. When Co-SR transmission is performed by multiple APs under Mode 1, UHR MU PPDUs and EHT MU PPDUs may be transmitted, or EHT MU PPDUs and EHT MU PPDUs may be transmitted, and the L-SIG contents of all PPDUs can be set identically, while the U-SIG contents may differ. Since the same L-SIG content is applied in Mode 1 and Mode 2, all PPDUs in Co-SR transmission can have the same length.

[0202] In mode 2, for all UHR MU PPDUs, Co-SR transmission can have the Co-BF / Co-SR indication field set to 0 when DL (e.g., UL / DL field is set to 0) and SU transmission (e.g., PPDU type and compression mode field values ​​are set to 1).

[0203] In Mode 1, for a UHR MU PPDU transmission, the UL / DL field is set to 0 (e.g., DL) and the PPDU type and compression mode fields are set to 1 (e.g., SU transmission), just as in Mode 2, the Co-BF / Co-SR indication field may be set to 0 (e.g., indicating that it is a Co-SR transmission). In this case, at another AP transmitting the EHT MU PPDU, the UL / DL field of the U-SIG in the PPDU may be set to 0 (e.g., DL) and the PPDU type and compression mode fields may be set to 1 (e.g., indicating that it is a general DL SU transmission). Accordingly, consistency between the operation according to Mode 1 and the operation according to Mode 2 can be maintained.

[0204] Additionally or alternatively, in Mode 1, the UL / DL field of the UHR MU PPDU can be set to 0 (e.g., DL), the PPDU type and compression mode fields can be set to 1 (e.g., SU transmission), and the Co-BF / Co-SR indication field can be set to 1 (e.g., to indicate that it is a general DL SU transmission). In Mode 1, since there is no need to consider / apply the same U-SIG content across different APs, more flexible Co-SR transmission can be supported.

[0205] Furthermore, Co-SR operation may be supported even for UHR STAs that do not support Co-SR (e.g., specific fields of the UHR PPDU are defined for UHR STAs that do not support Co-SR). More specifically, the fact that a certain STA does not support Co-SR may mean that, for example, when the STA is decoding a specific PPDU, an operation is applied to stop further decoding when the Co-BF / Co-SR indication field is set to 0. To this end, the second BSS color field (or BSS color 2 field) may be set to a value corresponding to validate and / or disregard, as in EHT. For example, among the B20-B25 bit positions corresponding to the BSS color 2 field of the U-SIG-1 part of U-SIG, B20-B24 may be set to disregard and B25 to validate.

[0206] In this case, at other APs transmitting the EHT MU PPDU, the UL / DL field of the U-SIG in the PPDU may be set to 0 (e.g., DL), and the PPDU type and compression mode fields may be set to 1 (e.g., to indicate that it is a standard DL SU transmission). Accordingly, consistency with Mode 2 and transmission of UHR PPDUs by all UHR STAs may be supported.

[0207] The examples described above may also apply to situations where a sharing or coordinating AP (e.g., an AP that is a TXOP holder and initiates Co-SR transmission) transmits an EHT PPDU, and a shared or coordinated AP (e.g., an AP participating in Co-SR transmission initiated by the sharing / coordinating AP) transmits a UHR PPDU.

[0208] Additionally or alternatively, in Mode 1, the UL / DL field of the UHR MU PPDU may be set to 0 (e.g., DL), the PPDU type and compression mode fields may be set to 0 (e.g., OFDMA), and the Co-BF / Co-SR indication field may be set to 1 (e.g., to indicate that it is a DL OFDMA transmission). In Mode 1, since there is no need to consider / apply the same U-SIG content across different APs, more flexible Co-SR transmission may be supported.

[0209] Furthermore, Co-SR operation may be supported even for UHR STAs that do not support Co-SR (e.g., specific fields of the UHR PPDU are defined for UHR STAs that do not support Co-SR and various PPDU types are supported). For example, the second BSS color field (or BSS color 2 field) may be set to a value corresponding to validate and / or disregard as in EHT (e.g., B20-B24 are set to disregard and B25 is set to validate). Also, in this case, at another AP transmitting the EHT MU PPDU, the UL / DL field of the U-SIG within the PPDU may be set to 0 (e.g., DL), and the PPDU type and compression mode fields may be set to 0 (e.g., to indicate that it is a DL OFDMA transmission).

[0210] Additionally or alternatively, in Mode 1, the UL / DL field of the UHR MU PPDU can be set to 0 (e.g., DL), the PPDU type and compression mode fields can be set to 2 (e.g., non-OFDMA MU MIMO), and the Co-BF / Co-SR indication field can be set to 1 (e.g., indicating that it is a DL non-OFDMA MU MIMO transmission). In Mode 1, since there is no need to consider / apply the same U-SIG across different APs, more flexible Co-SR transmissions can be supported.

[0211] Furthermore, Co-SR operation may be supported even for UHR STAs that do not support Co-SR (e.g., specific fields of the UHR PPDU are defined for UHR STAs that do not support Co-SR and various PPDU types are supported). For example, the second BSS color field (or BSS color 2 field) may be set to a value corresponding to validate and / or disregard as in EHT (e.g., B20-B24 are set to disregard and B25 is set to validate). Also, in this case, at another AP transmitting the EHT MU PPDU, the UL / DL field of the U-SIG within the PPDU may be set to 0 (e.g., DL), and the PPDU type and compression mode fields may be set to 2 (e.g., to indicate that it is a non-OFDMA MU MIMO transmission).

[0212] Additionally or alternatively, when the UL / DL field of the UHR MU PPDU in mode 1 is set to 0 (e.g., DL) and the PPDU type and compression mode fields are set to 2 (e.g., non-OFDMA MU MIMO), the Co-BF / Co-SR indication field may be restricted from being set to 0 (e.g., cases where DL non-OFDMA Co-BF transmission is indicated).

[0213] Additionally or alternatively, in mode 1, the UL / DL field of the UHR MU PPDU may be set to 0 (e.g., DL) and the PPDU type and compression mode fields may be restricted from being set to 3 (e.g., except when indicated as a UHR ELR transmission).

[0214] In mode 1, when all APs transmit EHT MU PPDU, even if the U-SIG content is not set identically, at least transmission of the same form (e.g., transmission of the same PPDU type) can be applied.

[0215] For example, when all APs transmit EHT MU PPDUs in Mode 1, the UL / DL field of the U-SIG in all PPDUs may be set to 0 (e.g., DL) and the PPDU type and compression mode fields may be set to 1 (e.g., indicating that it is a normal DL SU transmission). Accordingly, consistency with operation according to Mode 2 can be maintained.

[0216] Additionally or alternatively, when all APs transmit EHT MU PPDUs in Mode 1, the UL / DL field of U-SIG in all PPDUs may be set to 0 (e.g., DL) and the PPDU type and compression mode fields may be set to 0 (e.g., indicating that it is a DL OFDMA transmission).

[0217] Additionally or alternatively, when all APs transmit EHT MU PPDUs in Mode 1, the UL / DL field of the U-SIG in all PPDUs may be set to 0 (e.g., DL) and the PPDU type and compression mode fields may be set to 2 (e.g., indicating that it is a non-OFDMA MU MIMO transmission).

[0218] The B0-B3 bit positions within the common field of the UHR-SIG can be defined as a spatial reuse subfield. In the EHT-SIG as well, the B0-B3 bit positions within the common field are defined as a spatial reuse subfield. This spatial reuse subfield can indicate a specific value for spatial reuse.

[0219] In the case of Co-SR transmission, since spatial reuse is always applied, there is no need to additionally indicate a specific value through the spatial reuse subfield. With this in mind, in the present disclosure, for Co-SR transmission, the spatial reuse subfield may be set to a value corresponding to PSR (parameterized spatial reuse) disallow (e.g., 0) or to a value corresponding to PSR prohibited (e.g., 15). For example, in all PPDUs for Co-SR, the spatial reuse subfield may be set to a value corresponding to PSR disallow (e.g., 0) or to a value corresponding to PSR prohibited (e.g., 15). More specifically, for both Mode 1 and Mode 2 of Co-SR (or regardless of the mode), in all PPDUs for Co-SR, the spatial reuse subfield may be set to a value corresponding to PSR disallow (e.g., 0) or to a value corresponding to PSR prohibited (e.g., 15). For example, for both the EHT MU PPDU and UHR MU PPDU for Co-SR (or regardless of the PPDU version, within the common field of the EHT-SIG field or within the common field of the UHR-SIG field), the space reuse subfield can be set to a value corresponding to PSR disallowed (e.g., 0) or a value corresponding to PSR prohibited (e.g., 15).

[0220] Similarly, for Co-BF transmissions, the space reuse subfield can be set to a value corresponding to PSR disallowance (e.g., 0) or PSR prohibition (e.g., 15). For example, since Co-BF does not apply to EHT MU PPDU, the space reuse subfield within the common field of the UHR-SIG field of the UHR MU PPDU can be set to a value corresponding to PSR disallowance (e.g., 0) or PSR prohibition (e.g., 15).

[0221] Additionally or alternatively, when transmitting a UHR MU PPDU to a Co-SR, space reuse may not exist and may be set to a value corresponding to reserved, validate, or disregard. Similarly, when transmitting a UHR MU PPDU to a Co-BF, space reuse may not exist and may be set to a value corresponding to reserved, validate, or disregard.

[0222] Example 2

[0223] The UHR ELR PPDU format of Fig. 12(c) is defined to support enhanced coverage.

[0224] The ELR PPDU format can be used to overcome the difference between DL and UL ranges and to resolve link budget imbalances. By using the ELR PPDU format, long-distance communication can be supported while providing higher data rates compared to the DSSS (distribution system services) physical layer used in the existing 2.4 GHz band.

[0225] The ELR PPDU format can support 2.4 GHz, 5 GHz, and 6 GHz bands for UL, and 2.4 GHz band for DL. Additionally, the bandwidth of the ELR PPDU format can be limited to 20 MHz, and only a single spatial stream can be applied.

[0226] At the physical layer, UHR-MCS (modulation and coding scheme) 0 and 1 are supported for ELR PPDUs, and for improved reliability, 4x frequency domain duplication can be applied to 52-tone RRUs (regular RUs), and both BCC (binary convolutional code) and LDPC (low density parity check) channel coding can be applied.

[0227] The B0-B25 bit positions of the U-SIG-1 part of the U-SIG field in the UHR ELR PPDU may include, in order, a PHY version identifier (3 bits), bandwidth (3 bits), UL / DL (1 bit), BSS color (6 bits), TXOP (7 bits), disregard (5 bits), and validate (1 bit).

[0228] The B0-B25 bit positions of the U-SIG-2 part of the U-SIG field in the UHR MU PPDU may include, in order, PPDU type and compression mode (2 bits), STA-ID (11 bits), ELR validation (3 bits), CRC (4 bits), and tail (6 bits).

[0229] As previously mentioned, since the ELR PPDU uses only a bandwidth of 20 MHz, only the value 0 of the bandwidth field of the U-SIG corresponding to this is used, and the remaining values ​​1 through 7 may not be used. Here, values ​​1 through 7 of the bandwidth field are not always defined to correspond to validation, but values ​​1 through 5 of the bandwidth field may be defined as validation only when indicating an ELR PPDU (e.g., when the PPDU type and compression mode fields are set to 3). Next, values ​​6 and 7 of the bandwidth field may always be defined as validation, either in all UHR PPDU formats (e.g., UHR MU PPDU, UHR TB PPDU, or UHR ELT PPDU) or regardless of the PPDU format (e.g., for all values ​​of the PPDU type and compression mode fields, or regardless of the values ​​of the PPDU type and compression mode fields).

[0230] When the PPDU type and compression mode fields are set to a value other than 3 (wherein, excluding cases where the UL / DL field is set to 1 (e.g., UL) and the PPDU type and compression mode fields are set to 2), the value 1 of the bandwidth field may indicate 40 MHz, the value 2 may indicate 80 MHz, the value 3 may indicate 160 MHz, the value 4 may indicate 320 MHz-1, and the value 5 may indicate 320 MHz-2.

[0231] ELR PPDU can be used for both UL and DL in the 2.4 GHz band, but only for UL in the 5 GHz or 6 GHz band and not for DL. Therefore, the UL / DL field of the U-SIG in the ELR PPDU can only be set to 1. To clearly indicate this, in the 5 GHz or 6 GHz band, a value of 0 in the UL / DL field of the ELR PPDU can be defined as valid.

[0232] In existing wireless LAN systems, there is a problem in that the values ​​to which the subfield(s) of U-SIG, UHR-SIG, and / or ELR-SIG can be set in various PPDU types / formats are unclear. By defining them clearly and efficiently, it is possible to successfully decode PPDUs of various types / formats at the receiving STA.

[0233] The embodiments described above are combinations of the components and features of the present disclosure in a specific form. Each component or feature should be considered optional unless otherwise explicitly stated. Each component or feature may be implemented in a form not combined with other components or features. Additionally, it is possible to construct embodiments of the present disclosure by combining some components and / or features. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in another embodiment, or may be replaced with corresponding components or features of another embodiment. It is obvious that embodiments may be constructed by combining claims that are not explicitly related in the claims, or that they may be included as new claims by amendment after filing.

[0234] It is obvious to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the essential features of the present disclosure. Accordingly, the detailed description set forth above should not be interpreted restrictively in all respects and should be considered exemplary. The scope of the present disclosure shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present disclosure are included within the scope of the present disclosure.

[0235] The scope of the present disclosure includes software or machine-executable instructions (e.g., operating systems, applications, firmware, programs, etc.) that enable operations according to the methods of various embodiments to be executed on a device or computer, and a non-transitory computer-readable medium on which such software or instructions, etc. are stored and executable on a device or computer. Instructions that may be used to program a processing system to perform the features described in the present disclosure may be stored on or within a storage medium or a computer-readable storage medium, and the features described in the present disclosure may be implemented using a computer program product comprising such a storage medium. The storage medium may include, but is not limited to, high-speed random access memory such as DRAM, SRAM, DDR RAM, or other random access solid-state memory devices, and may include non-volatile memory such as one or more magnetic disk storage devices, optical disk storage devices, flash memory devices, or other non-volatile solid-state storage devices. The memory may optionally include one or more storage devices located remotely from the processor(s). Memory or alternatively, non-volatile memory device(s) within memory comprises a non-transient computer-readable storage medium. The features described in this disclosure may be stored in any one of the machine-readable media and integrated into software and / or firmware that can control the hardware of a processing system and allow the processing system to interact with other mechanisms utilizing results according to 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.

[0236] Although the method proposed in this disclosure has been described with an example applied to an IEEE 802.11-based system, it can be applied to various wireless LANs or wireless communication systems in addition to IEEE 802.11-based systems.

Claims

1. A step of generating a first PPDU (physical layer protocol data unit) by a first access point (AP) including a U-SIG (universal-signal) field and an additional SIG field; and The method includes the step of transmitting the first PPDU to a station (STA) by the first AP, Based on the fact that the above-mentioned first PPDU is a UHR (ultra-high reliability) MU (multi-user) PPDU and the above-mentioned additional SIG field is a UHR-SIG field: The above U-SIG field includes the UL / DL (uplink / downlink) field and the PPDU type and compression mode field; A method in which, for a Co-SR (coordinated spatial reuse) transmission or Co-BF (coordinated beamforming) transmission in which the first AP and the second AP participate, the spatial reuse subfield included in the UHR-SIG field is set to a value of 15 corresponding to PSR (parameterized spatial reuse) prohibited.

2. In Paragraph 1, A method in which, for the above Co-SR transmission, the first AP operates based on a second mode in which the UHR MU PPDU is transmitted from the first AP and the UHR MU PPDU is transmitted from the second AP.

3. In Paragraph 2, Based on the fact that the above UL / DL field is set to a value of 0 and the above PPDU type and compression mode fields are set to a value of 1: A method in which the Co-BF / Co-SR indication field included in the above U-SIG field is set to a value of 0 to indicate that it is a DL SU (single-user) Co-SR transmission.

4. In Paragraph 1, A method in which, for the above Co-SR transmission, the first AP operates based on a first mode in which the UHR MU PPDU is transmitted from the first AP and the EHT (extremely high throughput) MU PPDU is transmitted from the second AP.

5. In Paragraph 4, Based on the fact that the above UL / DL field is set to a value of 0 and the above PPDU type and compression mode fields are set to a value of 1: A method in which the Co-BF / Co-SR indicator field included in the above U-SIG field is set to a value of 1.

6. In Paragraph 4, The first BSS color (basic service set color) field included in the above U-SIG is the BSS color of the above first AP, and A method in which the second BSS color field included in the above U-SIG is set to a value corresponding to validate or disregard.

7. In Paragraph 1, Based on the fact that the first PPDU is an EHT MU PPDU and the additional SIG field is an EHT-SIG field: A method in which, for the above Co-SR transmission, the first AP operates based on a first mode in which the EHT MU PPDU is transmitted from the first AP and the UHR MU PPDU is transmitted from the second AP, or the EHT MU PPDU is transmitted from the first AP and another EHT MU PPDU is transmitted from the second AP.

8. In Paragraph 7, A method in which the above UL / DL field is set to a value of 0 and the above PPDU type and compression mode fields are set to a value of 1 to indicate that it is a DL SU transmission.

9. In Paragraph 7, The above UL / DL field is set to a value of 0 and the above PPDU type and compression mode fields are set to a value of 0 to indicate that it is a DL OFDMA (orthogonal frequency division multiple access) transmission, or A method in which the UL / DL field is set to a value of 0 and the PPDU type and compression mode fields are set to a value of 2 to indicate that it is a DL non-OFDMA transmission.

10. In Paragraph 1, The first AP above is an AP that initiates the Co-SR transmission or the Co-BF transmission, and A method in which the second AP is an AP participating in the Co-SR transmission or the Co-BF transmission initiated by the first AP.

11. In Paragraph 1, Based on the fact that the first PPDU is a UHR ELR (enhanced long range) PPDU and the additional SIG field is an ELR-SIG field: The PPDU type and compression mode fields included in the above U-SIG field are set to a value of 3; A method in which the bandwidth field included in the above U-SIG field is set to a value of 0 to indicate 20 MHz, and the values ​​of 1 to 7 of the bandwidth field are defined as validate.

12. In Paragraph 11, A method in which, in the 5 GHz band or 6 GHz band, a value of 0 of the UL / DL field included in the U-SIG field is defined as validation.

13. One or more transceivers; and It includes one or more processors connected to the above one or more transmitters and receivers, and The above one or more processors are: Generate a first PPDU (physical layer protocol data unit) including a U-SIG (universal-signal) field and an additional SIG field; and The above first PPDU is configured to be transmitted to a station (STA) through one or more transceivers, and Based on the fact that the above-mentioned first PPDU is a UHR (ultra-high reliability) MU (multi-user) PPDU and the above-mentioned additional SIG field is a UHR-SIG field: The above U-SIG field includes the UL / DL (uplink / downlink) field and the PPDU type and compression mode field; For a Co-SR (coordinated spatial reuse) transmission or Co-BF (coordinated beamforming) transmission in which the first access point (AP) and the second AP participate, the first AP, wherein the spatial reuse subfield included in the UHR-SIG field is set to a value of 15 corresponding to PSR (parameterized spatial reuse) prohibited.

14. A step of receiving a first PPDU (physical layer protocol data unit) containing a U-SIG (universal-signal) field and an additional SIG field from a first access point (AP) by a station (STA); and The method includes the step of decoding the first PPDU, and Based on the fact that the above-mentioned first PPDU is a UHR (ultra-high reliability) MU (multi-user) PPDU and the above-mentioned additional SIG field is a UHR-SIG field: The above U-SIG field includes the UL / DL (uplink / downlink) field and the PPDU type and compression mode field; A method in which, for a Co-SR (coordinated spatial reuse) transmission or Co-BF (coordinated beamforming) transmission in which the first AP and the second AP participate, the spatial reuse subfield included in the UHR-SIG field is set to a value of 15 corresponding to PSR (parameterized spatial reuse) prohibited.

15. One or more transceivers; and It includes one or more processors connected to the above one or more transmitters and receivers, and The above one or more processors are: Receiving a first PPDU (physical layer protocol data unit) including a U-SIG (universal-signal) field and an additional SIG field from a first access point (AP) through one or more transceivers; and It is configured to decode the above-mentioned first PPDU, and Based on the fact that the above-mentioned first PPDU is a UHR (ultra-high reliability) MU (multi-user) PPDU and the above-mentioned additional SIG field is a UHR-SIG field: The above U-SIG field includes the UL / DL (uplink / downlink) field and the PPDU type and compression mode field; For a Co-SR (coordinated spatial reuse) transmission or Co-BF (coordinated beamforming) transmission in which the first AP and the second AP participate, the spatial reuse subfield included in the UHR-SIG field is set to a value of 15, corresponding to PSR (parameterized spatial reuse) prohibited, STA.

16. One or more processors; and A processing device comprising one or more computer memories that are operably connected to one or more processors and store instructions for performing a method according to any one of claims 1 to 12 based on execution by one or more processors.

17. One or more non-transitory computer-readable media storing one or more instructions that are executed by one or more processors to control the execution of a method according to any one of claims 1 through 12.

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