WO2025009807A1 - Method and apparatus for managing network allocation vector configuration in wireless lan system - Google Patents

Abstract

The present disclosure relates to managing network allocation vector (NAV) configuration in a wireless LAN system. According to an embodiment of the present disclosure, a method performed by a station (STA) in a wireless LAN system comprises the steps of: detecting a first frame including information on a second basic service set (BSS) color different from a first BSS color of the STA; configuring a network allocation vector (NAV) on the basis of identifying at least one of a receiver address (RA) and a transmitter address (TA) of the first frame; storing information on the second BSS color; receiving, from an access point (AP) connected to the STA, a second frame including information on a coordination AP for the AP, wherein the information on the coordination AP includes information on a BSS color of the coordination AP; ignoring the NAV on the basis that the second BSS color corresponds to the BSS color of the coordination AP; and performing data transmission while ignoring the NAV.

Description

Method and device for managing network allocation vector settings in a wireless LAN system

The present disclosure relates to managing network allocation vector (NAV) settings in a wireless LAN system.

Next-generation Wi-Fi (e.g., IEEE 802.11be and/or later) aims to support ultra-high reliability in signal transmission to STAs, and various technologies are being considered to support high throughput, low latency, and extended range. For example, an STA (station) can set NAV if the RA (receiver address) of a received frame is not its own address, and may not transmit data during the set NAV period.

The present disclosure provides a method and device for managing NAV settings in a wireless LAN system.

According to an embodiment of the present disclosure, a method performed by a station (STA) in a wireless local area network (LAN) system includes: detecting a first frame including information about a second BSS color that is different from a first BSS (basic service set) color of the STA; setting a network allocation vector (NAV) based on identifying at least one of a receiver address (RA) or a transmitter address (TA) of the first frame; storing information about the second BSS color; receiving, from an access point (AP) connected to the STA, a second frame including information about a coordination AP for the AP, wherein the information about the coordination AP includes information about a BSS color of the coordination AP; and ignoring the NAV based on the second BSS color corresponding to the BSS color of the coordination AP; and performing data transmission while ignoring the NAV.

According to an embodiment of the present disclosure, a method performed by an access point (AP) in a wireless local area network (LAN) system includes the steps of: transmitting, to a station (STA) connected to the AP, a second frame including information of a coordinating AP for the AP, wherein the information of the coordinating AP includes information on a BSS color of the coordinating AP; and receiving, from the STA, data transmission, wherein the data transmission is performed while ignoring a network allocation vector (NAV) set to the STA, wherein the NAV is set based on identifying at least one of a receiver address (RA) or a transmitter address (TA) of a first frame including information on a second BSS color different from a first basic service set (BSS) color of the STA detected by the STA, and wherein the NAV is ignored based on the second BSS color corresponding to a BSS color of the coordinating AP.

In various embodiments, devices for implementing the methods described above are provided.

The present disclosure may have various advantageous effects.

For example, the present disclosure proposes NAV ignoring methods to solve a problem in which a non-AP STA cannot transmit UL PPDU/frame to a DAP due to a default NAV set by a SAP and/or a non-AP STA connected to the SAP in a multi-AP cooperation environment. According to the proposed methods, a non-AP STA connected to a DAP can ignore the default NAV set for the non-AP STA and transmit UL PPDU/frame to the DAP.

The advantageous effects that can be obtained through specific embodiments of the present disclosure are not limited to the advantageous effects listed above. For example, there may be various technical effects that can be understood and/or derived from the present disclosure by those skilled in the art. Therefore, the specific effects of the present disclosure are not limited to those explicitly described herein, and may include various effects that can be understood or derived from the technical features of the present disclosure.

FIG. 1 illustrates an example of a transmitting device and/or a receiving device of the present disclosure.

Figure 2 is a conceptual diagram showing the structure of a wireless local area network (WLAN).

Figure 3 is a diagram illustrating a general link setup process.

Figure 4 illustrates an embodiment of multi-link (ML).

FIG. 5 illustrates a modified example of a transmitter and/or receiver of the present disclosure.

FIG. 6 illustrates an example of a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted/received by an STA of the present disclosure.

Figure 7 is a diagram showing the layout of resource units (RUs) used for 20MHz PPDU.

Figure 8 is a diagram showing the layout of resource units (RUs) used for 40MHz PPDU.

Figure 9 is a diagram showing the layout of resource units (RUs) used for 80MHz PPDU.

Figure 10 shows the operation according to UL-MU.

Figure 11 shows an example of channels used/supported/defined within the 2.4 GHz band.

Figure 12 illustrates an example of channels used/supported/defined within the 5 GHz band.

Figure 13 illustrates an example of channels used/supported/defined within the 6 GHz band.

Figure 14 shows the trigger frame format.

Figure 15 shows an example of the user information field format of MU-RTS TXS TF.

Figure 16 shows an example of operation when the value of the TXOP shared mode subfield is 2.

Figure 17 illustrates an example of a procedure related to NAV setting.

Figure 18 shows an example of coordinated time division multiple access (C-TDMA) between cooperating APs.

Figure 19 shows an example of a multi-AP cooperative topology.

FIG. 20 illustrates an example of a method performed by a STA according to an embodiment of the present disclosure.

FIG. 21 illustrates an example of signal flow between a STA and an AP according to an embodiment of the present disclosure.

FIG. 22 illustrates a first example of a procedure for ignoring a default NAV that may be set by SAP according to an embodiment of the present disclosure.

FIG. 23 illustrates a second example of a procedure for ignoring a default NAV that may be set by SAP according to an embodiment of the present disclosure.

FIG. 24 illustrates an example of a procedure for ignoring a default NAV that may be set by a non-AP STA connected to a SAP according to an embodiment of the present disclosure.

In this disclosure, “A or B” can mean “only A,” “only B,” or “both A and B.” In other words, “A or B” in this disclosure can be interpreted as “A and/or B.” For example, “A, B or C” in this disclosure can mean “only A,” “only B,” “only C,” or “any combination of A, B and C.”

The slash (/) or comma used in this disclosure can mean “and/or.” For example, “A/B” can mean “A and/or B.” Accordingly, “A/B” can mean “only A,” “only B,” or “both A and B.” For example, “A, B, C” can mean “A, B, or C.”

In this disclosure, “at least one of A and B” can mean “only A,” “only B,” or “both A and B.” Additionally, in this disclosure, the expressions “at least one of A or B” or “at least one of A and/or B” can be interpreted identically to “at least one of A and B.”

In addition, the parentheses used in the present disclosure may mean “for example”. Specifically, when it is indicated as “control information (UHR-Signal field)”, the “UHR-Signal field” may be proposed as an example of the “control information”. In other words, the “control information” of the present disclosure is not limited to the “UHR -Signal field”, and the “UHR -Signal field” may be proposed as an example of the “control information”. In addition, even when it is indicated as “control information (UHR-Signal field)”, the “UHR-Signal field” may be proposed as an example of the “control information”.

Additionally, “a/an” as used in this disclosure can mean “at least one” or “one or more.” Additionally, a term ending with “(s)” can mean “at least one” or “one or more.”

Additionally, the expressions “based on” or “on the basis of” or “according to” as used in this disclosure mean “based at least in part on” and not “based sonly on.”

Technical features individually described in a single drawing in this disclosure may be implemented individually or simultaneously.

The following examples of the present disclosure can be applied to various wireless communication systems. For example, the following examples of the present disclosure can be applied to a wireless local area network (WLAN) system. For example, the present disclosure can be applied to the standards of IEEE 802.11a/g/n/ac/ax/be/bn. In addition, the examples of the present disclosure can be applied to the UHR (Ultra High Reliability) standard or the next-generation wireless LAN standard that enhances the IEEE 802.11bn. In addition, the examples of the present disclosure can be applied to a mobile communication system. For example, the examples of the present disclosure can be applied to a mobile communication system based on the LTE (Long Term Evolution) and its evolution based on the 3GPP (3rd Generation Partnership Project) standard.

In order to explain the technical features of the present disclosure, the following describes technical features to which the present disclosure can be applied.

FIG. 1 illustrates an example of a transmitting device and/or a receiving device of the present disclosure.

An example of FIG. 1 can perform various technical features described below. FIG. 1 relates to at least one STA (station). For example, the STA (110, 120) of the present disclosure may also be called by various names such as a mobile terminal, a wireless device, a Wireless Transmit/Receive Unit (WTRU), a User Equipment (UE), a Mobile Station (MS), a Mobile Subscriber Unit, or simply a user. The STA (110, 120) of the present disclosure may also be called by various names such as a network, a base station, a Node-B, an Access Point (AP), a repeater, a router, a relay, and so on. The STA (110, 120) of the present disclosure may also be called by various names such as a receiving apparatus, a transmitting apparatus, a receiving STA, a transmitting STA, a receiving device, a transmitting device, and so on.

For example, STA (110, 120) may perform an AP (access point) role or a non-AP role. That is, STA (110, 120) of the present disclosure may perform functions of AP and/or non-AP. In the present disclosure, AP may also be indicated as AP STA.

The STA (110, 120) of the present disclosure can support various communication standards other than the IEEE 802.11 standard. For example, it can support communication standards according to the 3GPP standard (e.g., LTE, LTE-A, 5G NR standard). In addition, the STA of the present disclosure can be implemented as various devices such as a mobile phone, a vehicle, a personal computer, etc. In addition, the STA of the present disclosure can support communication for various communication services such as voice call, video call, data communication, and autonomous driving (Self-Driving, Autonomous-Driving).

In the present disclosure, STA (110, 120) may include a medium access control (MAC) and a physical layer interface for a wireless medium following the provisions of the IEEE 802.11 standard.

Based on the sub-drawing (a) of Fig. 1, STA (110, 120) is explained as follows.

The first STA (110) may include a processor (111), a memory (112), and a transceiver (113). The illustrated processor, memory, and transceiver may each be implemented as separate chips, or at least two blocks/functions may be implemented through one chip.

The transceiver (113) of the first STA performs signal transmission and reception operations. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a/b/g/n/ac/ax/be, etc.).

For example, the first STA (110) can perform the intended operation of the AP. For example, the processor (111) of the AP can receive a signal through the transceiver (113), process the received signal, generate a transmission signal, and perform control for signal transmission. The memory (112) of the AP can store a signal received through the transceiver (113) (i.e., a reception signal) and store a signal to be transmitted through the transceiver (i.e., a transmission signal).

For example, the second STA (120) can perform the intended operation of the Non-AP STA. For example, the transceiver (123) of the non-AP performs a signal transmission and reception operation. Specifically, it can transmit and receive IEEE 802.11 packets (e.g., IEEE 802.11a/b/g/n/ac/ax/be, etc.).

For example, the processor (121) of the Non-AP STA can receive a signal through the transceiver (123), process the received signal, generate a transmission signal, and perform control for signal transmission. The memory (122) of the Non-AP STA can store a signal received through the transceiver (123) (i.e., a reception signal) and store a signal to be transmitted through the transceiver (i.e., a transmission signal).

For example, in the specification below, the operation of a device indicated as AP may be performed in the first STA (110) or the second STA (120). For example, when the first STA (110) is an AP, the operation of the device indicated as AP may be controlled by the processor (111) of the first STA (110), and a related signal may be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (110). In addition, control information related to the operation of the AP or a transmission/reception signal of the AP may be stored in the memory (112) of the first STA (110). In addition, when the second STA (110) is an AP, the operation of the device indicated as an AP is controlled by the processor (121) of the second STA (120), and a related signal may be transmitted or received through a transceiver (123) controlled by the processor (121) of the second STA (120). In addition, control information related to the operation of the AP or a transmission/reception signal of the AP may be stored in the memory (122) of the second STA (110).

For example, in the specification below, the operation of a device indicated as a non-AP (or User-STA) may be performed in the first STA (110) or the second STA (120). For example, if the second STA (120) is a non-AP, the operation of the device indicated as a non-AP may be controlled by the processor (121) of the second STA (120), and a related signal may be transmitted or received through a transceiver (123) controlled by the processor (121) of the second STA (120). In addition, control information related to the operation of the non-AP or a transmission/reception signal of the AP may be stored in the memory (122) of the second STA (120). For example, if the first STA (110) is a non-AP, the operation of a device indicated as a non-AP is controlled by the processor (111) of the first STA (110), and a related signal may be transmitted or received through a transceiver (113) controlled by the processor (111) of the first STA (120). In addition, control information related to the operation of the non-AP or the transmission/reception signal of the AP may be stored in the memory (112) of the first STA (110).

In the following specification, devices called (transmitting/receiving) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmitting/receiving) Terminal, (transmitting/receiving) device, (transmitting/receiving) apparatus, network, etc. may refer to the STA (110, 120) of FIG. 1. For example, devices indicated as (transmitting/receiving) STA, first STA, second STA, STA1, STA2, AP, first AP, second AP, AP1, AP2, (transmitting/receiving) Terminal, (transmitting/receiving) device, (transmitting/receiving) apparatus, network, etc. without specific drawing symbols may also refer to the STA (110, 120) of FIG. 1. For example, in the example below, the operation of various STAs transmitting and receiving signals (e.g., PPPDUs) may be performed by the transceiver (113, 123) of Fig. 1. In addition, in the example below, the operation of various STAs generating transmission and reception signals or performing data processing or calculations in advance for transmission and reception signals may be performed by the processor (111, 121) of Fig. 1. For example, an example of an operation for generating a transmit/receive signal or performing data processing or calculation in advance for a transmit/receive signal may include: 1) an operation for determining/acquiring/configuring/computing/decoding/encoding bit information of a subfield (SIG, STF, LTF, Data) field included in a PPDU, 2) an operation for determining/configuring/acquiring time resources or frequency resources (e.g., subcarrier resources) used for a subfield (SIG, STF, LTF, Data) field included in a PPDU, 3) an operation for determining/configuring/acquiring specific sequences (e.g., pilot sequences, STF/LTF sequences, extra sequences applied to SIG) used for a subfield (SIG, STF, LTF, Data) field included in a PPDU, 4) a power control operation and/or a power saving operation applied to an STA, 5) an operation related to determining/acquiring/configuring/computing/decoding/encoding an ACK signal, etc. In addition, in the examples below, various information (e.g., information related to fields/subfields/control fields/parameters/power, etc.) used by various STAs for determining/acquiring/configuring/computing/decoding/encoding transmission/reception signals can be stored in the memory (112, 122) of FIG. 1.

The device/STA of the sub-drawing (a) of FIG. 1 described above can be modified as in the sub-drawing (b) of FIG. 1. Hereinafter, the STA (110, 120) of the present disclosure will be described based on the sub-drawing (b) of FIG. 1.

For example, the transceiver (113, 123) illustrated in sub-drawing (b) of FIG. 1 may perform the same function as the transceiver illustrated in sub-drawing (a) of FIG. 1 described above. For example, the processing chip (114, 124) illustrated in sub-drawing (b) of FIG. 1 may include a processor (111, 121) and a memory (112, 122). The processor (111, 121) and the memory (112, 122) illustrated in sub-drawing (b) of FIG. 1 may perform the same function as the processor (111, 121) and the memory (112, 122) illustrated in sub-drawing (a) of FIG. 1 described above.

The mobile terminal, the wireless device, the Wireless Transmit/Receive Unit (WTRU), the User Equipment (UE), the Mobile Station (MS), the Mobile Subscriber Unit, the user, the user STA, the network, the Base Station, the Node-B, the Access Point (AP), the repeater, the router, the relay, the receiving device, the transmitting device, the receiving STA, the transmitting STA, the receiving Device, the transmitting Device, the receiving Apparatus, and/or the transmitting Apparatus described below may refer to the STA (110, 120) illustrated in the sub-drawings (a)/(b) of FIG. 1, or may refer to the processing chip (114, 124) illustrated in the sub-drawing (b) of FIG. 1. That is, the technical feature of the present disclosure may be performed in the STA (110, 120) illustrated in the sub-drawings (a)/(b) of FIG. 1, or may be performed only in the processing chip (114, 124) illustrated in the sub-drawings (b) of FIG. 1. For example, the technical feature that the transmitting STA transmits a control signal may be understood as a technical feature that the control signal generated in the processor (111, 121) illustrated in the sub-drawings (a)/(b) of FIG. 1 is transmitted through the transceiver (113, 123) illustrated in the sub-drawings (a)/(b) of FIG. 1. Alternatively, the technical feature that the transmitting STA transmits a control signal may be understood as a technical feature that the control signal to be transmitted to the transceiver (113, 123) is generated in the processing chip (114, 124) illustrated in the sub-drawings (b) of FIG. 1.

For example, a technical feature of a receiving STA receiving a control signal may be understood as a technical feature of a control signal being received by a transceiver (113, 123) illustrated in a sub-drawing (a) of FIG. 1. Alternatively, a technical feature of a receiving STA receiving a control signal may be understood as a technical feature of a control signal received by a transceiver (113, 123) illustrated in a sub-drawing (a) of FIG. 1 being acquired by a processor (111, 121) illustrated in a sub-drawing (a) of FIG. 1. Alternatively, a technical feature of a receiving STA receiving a control signal may be understood as a technical feature of a control signal received by a transceiver (113, 123) illustrated in a sub-drawing (b) of FIG. 1 being acquired by a processing chip (114, 124) illustrated in a sub-drawing (b) of FIG.

Referring to the sub-drawing (b) of FIG. 1, software code (115, 125) may be included in the memory (112, 122). The software code (115, 125) may include instructions that control the operation of the processor (111, 121). The software code (115, 125) may be included in various programming languages.

The processor (111, 121) or the processing chip (114, 124) illustrated in FIG. 1 may include an application-specific integrated circuit (ASIC), another chipset, a logic circuit, and/or a data processing device. The processor may be an application processor (AP). For example, the processor (111, 121) or the processing chip (114, 124) illustrated in FIG. 1 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modem (modulator and demodulator). For example, the processor (111, 121) or processing chip (114, 124) illustrated in FIG. 1 may be a SNAPDRAGON® series processor manufactured by Qualcomm®, an EXYNOS® series processor manufactured by Samsung®, an A series processor manufactured by Apple®, a HELIO® series processor manufactured by MediaTek®, an ATOM® series processor manufactured by INTEL®, or a processor that enhances these.

In the present disclosure, the uplink may mean a link for communication from a non-AP STA to an AP STA, and an uplink PPDU/packet/signal, etc. may be transmitted through the uplink. In addition, in the present disclosure, the downlink may mean a link for communication from an AP STA to a non-AP STA, and a downlink PPDU/packet/signal, etc. may be transmitted through the downlink.

Figure 2 is a conceptual diagram showing the structure of a wireless local area network (WLAN).

The upper part of Figure 2 shows the structure of the infrastructure BSS (basic service set) of IEEE (institute of electrical and electronic engineers) 802.11.

Referring to the top of FIG. 2, the wireless LAN system may include one or more infrastructure BSS (200, 205) (hereinafter, BSS). The BSS (200, 205) is a set of APs and STAs, such as an access point (AP) 225 and a station (STA1, 200-1), which are successfully synchronized and can communicate with each other, and is not a concept referring to a specific area. The BSS (205) may include one or more STAs (205-1, 205-2) that can be coupled to one AP (230).

A BSS may include at least one STA, an AP (225, 230) providing a distribution service, and a distribution system (DS, 210) connecting multiple APs.

The distributed system (210) can implement an extended service set (ESS, 240) by connecting multiple BSSs (200, 205). The ESS (240) can be used as a term indicating a network formed by connecting one or more APs through the distributed system (210). The APs included in one ESS (240) can have the same SSID (service set identification).

The portal (portal, 220) can act as a bridge to connect a wireless LAN network (IEEE 802.11) to another network (e.g., 802.X).

In a BSS such as the upper part of Fig. 2, a network between APs (225, 230) and a network between APs (225, 230) and STAs (200-1, 205-1, 205-2) can be implemented. However, it may also be possible to establish a network and perform communication between STAs without an AP (225, 230). A network that establishes a network and performs communication between STAs without an AP (225, 230) is defined as an ad-hoc network or an independent basic service set (IBSS).

The bottom of Figure 2 is a conceptual diagram showing IBSS.

Referring to the bottom of Fig. 2, IBSS is a BSS operating in ad-hoc mode. Since IBSS does not include AP, there is no centralized management entity. That is, in IBSS, STAs (250-1, 250-2, 250-3, 255-4, 255-5) are managed in a distributed manner. In IBSS, all STAs (250-1, 250-2, 250-3, 255-4, 255-5) can be mobile STAs, and access to the distributed system is not permitted, forming a self-contained network.

Figure 3 is a diagram illustrating a general link setup process.

In the illustrated S310 step, the STA may perform a network discovery operation. The network discovery operation may include a scanning operation of the STA. That is, in order for the STA to access the network, it must find a network that it can participate in. The STA must identify a compatible network before participating in the wireless network, and the process of identifying networks existing in a specific area is called scanning. There are two types of scanning methods: active scanning and passive scanning.

FIG. 3 illustrates a network discovery operation including an active scanning process as an example. In active scanning, an STA performing scanning transmits a probe request frame to search for any APs in the vicinity while moving between channels and waits for a response thereto. A responder transmits a probe response frame to the STA that transmitted the probe request frame as a response to the probe request frame. Here, the responder may be an STA that last transmitted a beacon frame in the BSS of the channel being scanned. In the BSS, the AP transmits a beacon frame, so the AP becomes the responder, and in the IBSS, the STAs within the IBSS take turns transmitting beacon frames, so the responder is not constant. For example, an STA that transmits a probe request frame on channel 1 and receives a probe response frame on channel 1 can store BSS-related information included in the received probe response frame and move to the next channel (e.g., channel 2) to perform scanning (i.e., transmitting and receiving probe request/response on channel 2) in the same manner.

Although not shown in the example of FIG. 3, the scanning operation may also be performed in a passive scanning manner. An STA performing scanning based on passive scanning may wait for a beacon frame while moving between channels. A beacon frame is one of the management frames in IEEE 802.11, and is periodically transmitted to notify the existence of a wireless network and to enable an STA performing scanning to find a wireless network and participate in the wireless network. In a BSS, an AP periodically transmits a beacon frame, and in an IBSS, STAs in the IBSS take turns transmitting beacon frames. When an STA performing scanning receives a beacon frame, it stores information about the BSS included in the beacon frame and moves to another channel, recording beacon frame information in each channel. An STA receiving a beacon frame stores information related to the BSS included in the received beacon frame, moves to the next channel, and performs scanning on the next channel in the same manner.

An STA that has discovered a network may perform an authentication process through step S320. This authentication process may be referred to as a first authentication process in order to clearly distinguish it from the security setup operation of step S340 described below. The authentication process of S320 may include a process in which the STA transmits an authentication request frame to the AP, and in response, the AP transmits an authentication response frame to the STA. The authentication frame used for the authentication request/response corresponds to a management frame.

The authentication frame may include information such as an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a Robust Security Network (RSN), and a Finite Cyclic Group.

The STA may transmit an authentication request frame to the AP. The AP may determine whether to allow authentication for the STA based on the information included in the received authentication request frame. The AP may provide the result of the authentication processing to the STA through an authentication response frame.

A successfully authenticated STA may perform an association process based on step S330. The association process includes a process in which the STA transmits an association request frame to the AP, and in response, the AP transmits an association response frame to the STA. For example, the association request frame may include information related to various capabilities, a beacon listen interval, an SSID (service set identifier), supported rates, supported channels, RSN, mobility domain, supported operating classes, TIM broadcast request (Traffic Indication Map Broadcast request), interworking service capabilities, and the like. For example, the association response frame may contain information related to various capabilities, status codes, Association ID (AID), supported rates, Enhanced Distributed Channel Access (EDCA) parameter sets, Received Channel Power Indicator (RCPI), Received Signal to Noise Indicator (RSNI), mobility domains, timeout interval (association comeback time), overlapping BSS scan parameters, TIM broadcast response, QoS maps, etc.

In step S340, the STA may perform a security setup process. The security setup process of step S340 may include a process of performing private key setup, for example, through 4-way handshaking via an Extensible Authentication Protocol over LAN (EAPOL) frame.

Figure 4 illustrates an example of multi-link (ML).

As illustrated in FIG. 4, a plurality of multi-link devices (MLDs) can perform communication over a remote link. The MLDs can be classified into an AP MLD including a plurality of AP STAs and a non-AP MLD including a plurality of non-AP STAs. That is, the AP MLD can include affiliated APs (i.e., AP STAs), and the non-AP MLD can include affiliated STAs (i.e., non-AP STAs, or user-STAs).

A multilink may include a first link and a second link, and different channels/subchannels/frequency resources may be allocated to the first and second links. The first and second multilinks may be identified through a link ID of 4 bits in length (or other n bits in length). The first and second links may be configured in the same 2.4 GHz, 5 GHz, or 6 GHz band. Alternatively, the first link and the link may be configured in different bands.

The AP MLD of FIG. 4 includes three affiliated APs. In the example of FIG. 4, AP1 may operate in a 2.4 GHz band, AP2 may operate in a 5 GHz band, and AP3 may operate in a 6 GHz band. In the example of FIG. 4, a first link in which AP1 and non-AP1 operate may be defined by channel/subchannel/frequency resources within the 2.4 GHz band. In addition, a second link in the example of FIG. 4 in which AP2 and non-AP2 operate may be defined by channel/subchannel/frequency resources within the 5 GHz band. In addition, a third link in the example of FIG. 4 in which AP3 and non-AP3 operate may be defined by channel/subchannel/frequency resources within the 6 GHz band.

In the example of FIG. 4, AP1 can start a multilink setup procedure (ML setup procedure) by transmitting an Association Request frame to non-AP STA1. In the example of FIG. 4, non-AP STA1 can transmit an Association Response frame in response to the Association Request frame. Each AP (e.g., AP1/2/3) illustrated in FIG. 4 may be identical to the AP illustrated in FIG. 1 and/or FIG. 2, and each non-AP (e.g., non-AP1/2/3) illustrated in FIG. 4 may be identical to a STA (i.e., user-STA or non-AP STA) illustrated in FIG. 1 and/or FIG. 2.

The specific features of the present disclosure are not limited to the specific features of FIG. 4. That is, the number of links can be variously defined, and a plurality of links can be variously defined within at least one band.

FIG. 5 illustrates a modified example of a transmitter and/or receiver of the present disclosure.

The devices (e.g., AP STA, non-AP STA) illustrated in FIGS. 1 to 4 may be modified as illustrated in FIG. 5. The transceiver (530) of FIG. 5 may be identical to the transceiver (113, 123) of FIG. 1. The transceiver (530) of FIG. 5 may include a receiver and a transmitter.

The processor (510) of FIG. 5 may be identical to the processor (111, 121) of FIG. 1. Alternatively, the processor (510) of FIG. 5 may be identical to the processing chip (114, 124) of FIG. 1.

The memory (150) of Fig. 5 may be the same as the memory (112, 122) of Fig. 1. Alternatively, the memory (150) of Fig. 5 may be a separate external memory different from the memory (112, 122) of Fig. 1.

Referring to FIG. 5, a power management module (511) manages power to the processor (510) and/or the transceiver (530). A battery (512) supplies power to the power management module (511). A display (513) outputs a result processed by the processor (510). A keypad (514) receives input to be used by the processor (510). The keypad (514) may be displayed on the display (513). A SIM card (515) may be an integrated circuit used to securely store an international mobile subscriber identity (IMSI) and an associated key used to identify and authenticate a subscriber in a mobile phone device, such as a mobile phone and a computer.

Referring to FIG. 5, the speaker (540) can output sound-related results processed by the processor (510). The microphone (541) can receive sound-related input to be used by the processor (510).

FIG. 6 illustrates an example of a PPDU (physical protocol data unit or physical layer (PHY) protocol data unit) transmitted/received by an STA of the present disclosure.

The STA (e.g., AP STA, non-AP STA, AP MLD, non-AP MLD) of the present disclosure can transmit and/or receive the PPDU of FIG. 6. The PPDU described in the present disclosure can have, for example, the structure of FIG. 6. In addition, the PPDU described in the present disclosure can be called by various names such as a transmission PPDU, a reception PPDU, a first type or an Nth type PPDU, etc. The PPDU described in the present disclosure can be used in a WLAN system defined according to IEEE 802.11bn and/or a next-generation WLAN system that improves IEEE 802.11bn.

The PPDU of FIG. 6 may relate to various PPDU types used in a UHR system. For example, the example of FIG. 6 may be used for at least one of a SU (single-user) mode/type/transmission, a MU (multi-user) mode/type/transmission, and a NDP (null data packet) mode/type/transmission related to channel sounding. For example, if the example of FIG. 6 relates to NDP, the Data field illustrated may be omitted. If the PPDU of FIG. 6 is used for a TB (Trigger-based) mode, the UHR-SIG of FIG. 6 may be omitted. In other words, an STA that has received a Trigger frame for UL-MU (Uplink-MU) communication may transmit a PPDU with the UHR-SIG omitted in the example of FIG. 6.

In Fig. 6, L-STF to UHR-LTF may be called a preamble or a physical preamble, and may be generated/transmitted/received/acquired/decoded in the physical layer (included in the transmitting/receiving STA).

Each block illustrated in Fig. 6 may be called a field/subfield/signal, etc. The names of these fields/subfields/signals may be, as illustrated in Fig. 6, L-STF (legacy short training field), L-LTF (legacy long training field), L-SIG (legacy signal), RL-SIG (repeated L-SIG), U-SIG (Universal Signal), UHR-SIG (UHR-signal), etc.

The subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields of FIG. 6 may be set to 312.5 kHz, and the subcarrier spacing of the UHR-STF, UHR-LTF, and Data fields may be set to 78.125 kHz. That is, the tone index (or subcarrier index) of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields may be expressed in units of 312.5 kHz, and the tone index (or subcarrier index) of the UHR-STF, UHR-LTF, and Data fields may be expressed in units of 78.125 kHz.

In the PPDU of Fig. 6, L-LTF and L-STF can be identical to conventional fields (e.g., non-HT LTF and non-HT STF defined in conventional WLAN standards).

The L-SIG field of FIG. 6 may include, for example, 24 bits of bit information. For example, the 24 bits of information may include a 4 bit Rate field, a 1 bit Reserved bit, a 12 bit Length field, a 1 bit Parity bit, and a 6 bit Tail bit. For example, the 12 bit Length field may include information about the length or time duration of the PPDU. For example, the value of the 12 bit Length field may be determined based on the type of the PPDU. For example, if the PPDU is a non-HT (non-High Throughput), HT (High Throughput), VHT (Very High Throughput) PPDU, or an EHT (extremely high throughput) PPDU, a UHR PPDU, the value of the Length field may be determined as a multiple of 3. For example, if the PPDU is a HE PPDU, the value of the Length field may be determined as "a multiple of 3 + 1" or "a multiple of 3 + 2". In other words, for non-HT, HT, VHT PPDU, EHT PPDU, UHR PPDU, the value of the Length field can be determined as a multiple of 3, and for HE (High-Efficiency) PPDU, the value of the Length field can be determined as "a multiple of 3 + 1" or "a multiple of 3 + 2". In other words, the LENGTH field in an UHR PPDU is set to a value satisfying the condition that the remainder is zero when LENGTH is divided by 3.

For example, the (non-AP and AP) STA can apply BCC encoding based on a code rate of 1/2 to the 24 bits of information in the L-SIG field. Then, the transmitting STA can obtain 48 bits of BCC coding bits. BPSK modulation can be applied to the 48 bits of coding bits to generate 48 BPSK symbols. The transmitting STA can map the 48 BPSK symbols to positions excluding the pilot subcarriers {subcarrier index -21, -7, +7, +21} and the DC subcarrier {subcarrier index 0}. As a result, the 48 BPSK symbols can be mapped to subcarrier indices -26 to -22, -20 to -8, -6 to -1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA can additionally map the signal of {-1, -1, -1, 1} to the subcarrier indices {-28, -27, +27, +28}. The above signal can be used for channel estimation for the frequency domain corresponding to {-28, -27, +27, +28}.

For example, (non-AP and AP) STA can generate RL-SIG, which is generated in the same manner as L-SIG. BPSK modulation can be applied to RL-SIG. The receiving (non-AP and AP) STA can determine that the received PPDU is a HE PPDU, an EHT PPDU, or a UHR PPDU based on the presence of RL-SIG. In other words, the receiving (non-AP and AP) STA can determine that the received PPDU is one of the HE PPDU, EHT PPDU, or UHR PPDU if RL-SIG is present. In other words, the receiving (non-AP and AP) STA can determine that the received PPDU is one of the non-HT PPDU, HT PPDU, or VHT PPDU if RL-SIG is not present. In other words, the RL-SIG field is a repeat of the L-SIG field and is used to differentiate an UHR PPDU from a non-HT PPDU, HT PPDU, and VHT PPDU.

After the RL-SIG in Fig. 6, a U-SIG (Universal SIG) may be inserted. The U-SIG may be called by various names such as the first SIG field, the first SIG, the first type SIG, the control signal, the control signal field, the first (type) control signal, the common control field, and the common control signal.

The U-SIG can contain N bits of information and can contain information for identifying the type of the EHT PPDU. For example, the U-SIG can be formed based on two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG can have a duration of 4 us. 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.

Through U-SIG, for example, A bit information (e.g., 52 un-coded bits) can be transmitted, and the first symbol of U-SIG can transmit the first X bits of information (e.g., 26 un-coded bits) out of the total A bit information, and the second symbol of U-SIG can transmit the remaining Y bits of information (e.g., 26 un-coded bits) out of the total A bit information. For example, the transmitting STA can obtain 26 un-coded bits included in each U-SIG symbol. The transmitting STA can perform convolutional encoding (i.e., BCC encoding) based on a rate of R=1/2 to generate 52-coded bits, and perform interleaving on the 52-coded bits. The transmitting STA can perform BPSK modulation on the interleaved 52-coded bits to generate 52 BPSK symbols allocated to each U-SIG symbol. A single U-SIG symbol can be transmitted based on 56 tones (subcarriers) from subcarrier index -28 to subcarrier index +28, excluding DC index 0. The 52 BPSK symbols generated by the transmitting STA can be transmitted based on the remaining tones (subcarriers) excluding the pilot tones -21, -7, +7, and +21.

For example, A bit information (e.g., 52 un-coded bits) transmitted by U-SIG may include a CRC field (e.g., a field having a length of 4 bits) and a tail field (e.g., a field having a length of 6 bits). The CRC field and the tail field may be transmitted through a second symbol of the U-SIG. The CRC field may be generated based on 26 bits allocated to the first symbol of the U-SIG and the remaining 16 bits excluding the CRC/tail field within the second symbol, and may be generated based on a conventional CRC calculation algorithm. In addition, the tail field may be used to terminate a trellis of a convolutional decoder and may be set to, for example, "000000".

The A bit information (e.g., 52 uncoded bits) transmitted by the U-SIG (or U-SIG field) can be divided into version-independent bits and version-dependent bits. For example, the size of the version-independent bits can be fixed or variable. For example, the version-independent bits can be assigned only to the first symbol of the U-SIG, or the version-independent bits can be assigned to both the first symbol and the second symbol of the U-SIG. For example, the version-independent bits and the version-dependent bits can be called by various names, such as the first control bit and the second control bit.

For example, the version-independent bits of U-SIG may include a 3-bit PHY version identifier. For example, the 3-bit PHY version identifier may include information related to the PHY version of a transmitted/received PPDU. For example, a first value (e.g., a value of 000) of the 3-bit PHY version identifier may indicate that the transmitted/received PPDU is an EHT PPDU. Additionally, a second value (e.g., a value of 001) of the 3-bit PHY version identifier may indicate that the transmitted/received PPDU is a UHR PPDU.

In other words, when the (AP/non-AP) STA transmits an EHT PPDU, the 3-bit PHY version identifier can be set to the first value. In other words, the receiving (AP/non-AP) STA can determine that the received PPDU is an EHT PPDU based on the PHY version identifier having the first value, and can determine that the received PPDU is a UHR PPDU based on the PHY version identifier having the second value.

For example, 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.

For example, the version-independent bits of U-SIG may include information about the length of a transmission opportunity (TXOP) and information about the BSS color ID.

For example, if a UHR PPDU is classified into various types (e.g., type related to SU transmission (performed based on UL or DL), type related to DL transmission, type related to NDP transmission, type related to DL non-MU-MIMO, type related to DL MU-MIMO, type related to Multi-AP operation, type related to CBF (Coordinated beamforming), SR (Spatial Reuse), type related to C-OFDMA (Coordinated OFDMA), type related to C-TDMA (Coordinated TDMA)), information about the type of the EHT PPDU (e.g., 2-bit or 3-bit information) can be included in the version-dependent bits of the U-SIG.

For example, U-SIG may include 1) a bandwidth field including information about bandwidth, 2) a field including information about a Modulation and Coding Scheme (MCS) technique applied to UHR-SIG, 3) an indication field including information related to whether a dual subcarrier modulation (DCM) technique is applied to UHR-SIG, 4) a field including information about the number of symbols used for UHR-SIG, 5) a field including information about whether UHR-SIG is generated over the full band, 6) a field including information about the type of UHR-LTF/STF, and 7) a field indicating the length of UHR-LTF and the CP length.

Preamble puncturing can be applied to the PPDU of FIG. 6. Preamble puncturing means applying puncturing to a portion of the entire band of the PPDU (e.g., the secondary 20 MHz band). For example, when an 80 MHz PPDU is transmitted, the STA can apply puncturing to the secondary 20 MHz band among the 80 MHz band, and transmit the PPDU only through the primary 20 MHz band and the secondary 40 MHz band.

For example, the pattern of preamble puncturing can be set in advance. For example, when the first puncturing pattern is applied, puncturing can be applied only to a secondary 20 MHz band within an 80 MHz band. For example, when the second puncturing pattern is applied, puncturing can be applied only to one of two secondary 20 MHz bands included in a secondary 40 MHz band within an 80 MHz band. For example, when the third puncturing pattern is applied, puncturing can be applied only to a secondary 20 MHz band included in a primary 80 MHz band within a 160 MHz band (or an 80+80 MHz band). For example, when the 4th puncturing pattern is applied, a primary 40 MHz band included in the primary 80 MHz band within the 160 MHz band (or 80+80 MHz band) is present, and puncturing can be applied to at least one 20 MHz channel that does not belong to the primary 40 MHz band.

Information about preamble puncturing applied to the PPDU may be included in the U-SIG and/or UHR-SIG. For example, a first field of the U-SIG may include information about a contiguous bandwidth of the PPDU, and a second field of the U-SIG may include information about preamble puncturing applied to the PPDU.

For example, U-SIG and UHR-SIG may include information regarding preamble puncturing based on the following method. If the bandwidth of the PPDU exceeds 80 MHz, U-SIGs may be individually configured in units of 80 MHz. For example, if the bandwidth of the PPDU is 160 MHz, the PPDU may include a first U-SIG for a first 80 MHz band and a second U-SIG for a second 80 MHz band. In this case, the first field of the first U-SIG may include information regarding the 160 MHz bandwidth, and the second field of the first U-SIG may include information regarding preamble puncturing applied to the first 80 MHz band (i.e., information regarding a preamble puncturing pattern). Additionally, the first field of the second U-SIG may include information about a 160 MHz bandwidth, and the second field of the second U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about a preamble puncturing pattern). Meanwhile, the UHR-SIG consecutive to the first U-SIG may include information about preamble puncturing applied to the second 80 MHz band (i.e., information about a preamble puncturing pattern), and the UHR-SIG consecutive to the second U-SIG may include information about preamble puncturing applied to the first 80 MHz band (i.e., information about a preamble puncturing pattern).

Additionally or alternatively, U-SIG and UHR-SIG may include information about preamble puncturing based on the following methods. U-SIG may include information about preamble puncturing for all bands (i.e., information about preamble puncturing pattern). That is, UHR-SIG does not include information about preamble puncturing, and only U-SIG may include information about preamble puncturing (i.e., information about preamble puncturing pattern).

U-SIG can be configured in 20 MHz units. For example, if an 80 MHz PPDU is configured, U-SIG can be duplicated. That is, four identical U-SIGs can be included in an 80 MHz PPDU. PPDUs exceeding 80 MHz bandwidth can contain different U-SIGs.

The UHR-SIG of FIG. 6 may include control information for a receiving STA. The UHR-SIG may be transmitted through at least one symbol, and one symbol may have a length of 4 us. Information about the number of symbols used for the UHR-SIG may be included in the U-SIG.

UHR-SIG provides additional signals to the U-SIG field to enable STAs to interpret/decode UHR PPDUs. The UHR-SIG field may contain U-SIG overflow bits that are common to all users. The UHR-SIG field also contains resource allocation information, allowing STAs to look up resources used in fields containing data fields/UHR-STF/UHR-LTF (i.e., UHR modulated fields of an UHR PPDU).

The frequency resources of the UHR-LTF, UHR-STF, and data fields illustrated in FIG. 6 can be determined based on RUs (resource units) defined by multiple subcarriers/tones. That is, the UHR-LTF, UHR-STF, and data fields of the present disclosure can be transmitted/received through RUs (resource units) defined by multiple subcarriers/tones.

FIG. 7 is a diagram showing the layout of resource units (RUs) used for 20 MHz PPDU. That is, UHR-LTF, UHR-STF and/or data fields included in a 20 MHz PPDU can be transmitted/received through at least one of various RUs defined in FIG. 7.

As shown in the top of Fig. 7, 26 units (i.e., units corresponding to 26 tones) can be arranged. Six tones can be used as a guard band in the leftmost band of the 20MHz band, and five tones can be used as a guard band in the rightmost band of the 20MHz band. In addition, seven DC tones can be inserted in the center band, i.e., the DC band, and 26 units corresponding to 13 tones can exist on the left and right sides of the DC band, respectively. In addition, 26 units, 52 units, and 106 units can be allocated to other bands. Each unit can be allocated for a receiving station, i.e., a user.

Meanwhile, the RU arrangement of Fig. 7 is utilized not only in a situation for multiple users (MUs) but also in a situation for a single user (SU), in which case it is possible to use one 242-unit as shown at the bottom of Fig. 4, in which case three DC tones can be inserted.

In the example of Fig. 7, RUs of various sizes, i.e., 26-RU, 52-RU, 106-RU, 242-RU, etc., are proposed, and since the specific sizes of these RUs can be expanded or increased, the present embodiment is not limited to the specific size of each RU (i.e., the number of corresponding tones). In the present disclosure, N-RU may be represented as N-tone RU, etc. For example, 26-RU may be represented as 26-tone RU.

Figure 8 is a diagram showing the layout of resource units (RUs) used for 40MHz PPDU.

As in the example of FIG. 7 where RUs of various sizes were used, the example of FIG. 8 can also use 26-RU, 52-RU, 106-RU, 242-RU, 484-RU, etc. In addition, five DC tones can be inserted at the center frequency, 12 tones can be used as a guard band in the leftmost band of the 40 MHz band, and 11 tones can be used as a guard band in the rightmost band of the 40 MHz band.

Also, as illustrated, when used for a single user, 484-RU can be used. Meanwhile, the specific number of RUs can be changed, which is the same as the example of Fig. 7.

FIG. 9 is a diagram showing the layout of resource units (RUs) used for 80MHz PPDU. The layout of resource units (RUs) used in the present disclosure may be varied. For example, the layout of resource units (RUs) used on an 80MHz band may be varied.

Fig. 10 shows an operation according to UL-MU. As illustrated, a transmitting STA (e.g., AP) may obtain a TXOP (1025) by performing channel access through contending (i.e., Backoff operation) and transmit a Trigger frame (1030). That is, the transmitting STA (e.g., AP) may transmit a PPDU including a Trigger Frame (1030). When a PPDU including a Trigger frame is received, a TB (trigger-based) PPDU is transmitted after a delay of SIFS.

TB PPDU (1041, 1042) can be transmitted at the same time zone and can be transmitted from multiple STAs (e.g., User STAs) whose AIDs are indicated in the Trigger frame (1030). The ACK frame (1050) for TB PPDU can be implemented in various forms. For example, the ACK frame (1050) for TB PPDU can be implemented in the form of BA (block ACK).

In FIG. 10, transmission(s) of Trigger Frame (1030), TB PPDU (1041, 1042) and/or ACK frame (1050) can be performed within TXOP (1025).

Figure 11 shows an example of channels used/supported/defined within the 2.4 GHz band.

The 2.4 GHz band may be referred to by other names, such as the first band (band), etc. In addition, the 2.4 GHz band may refer to a frequency range in which channels with center frequencies adjacent to 2.4 GHz (e.g., channels with center frequencies located within 2.4 to 2.5 GHz) are used/supported/defined.

A 2.4 GHz band may include multiple 20 MHz channels. The 20 MHz within the 2.4 GHz band may have multiple channel indices (e.g., indices 1 to 14). For example, a 20 MHz channel to which channel index 1 is assigned may have a center frequency of 2.412 GHz, a 20 MHz channel to which channel index 2 is assigned may have a center frequency of 2.417 GHz, and a 20 MHz channel to which channel index N is assigned may have a center frequency of (2.407 + 0.005*N) GHz. The channel indices may be referred to by various names, such as channel numbers. The specific numerical values of the channel indices and center frequencies may change.

Fig. 11 exemplarily shows four channels within the 2.4 GHz band. The illustrated first frequency domain (1110) to fourth frequency domain (1140) may each include one channel. For example, the first frequency domain (1110) may include channel 1 (a 20 MHz channel having an index of 1). In this case, the center frequency of channel 1 may be set to 2412 MHz. The second frequency domain (1120) may include channel 6. In this case, the center frequency of channel 6 may be set to 2437 MHz. The third frequency domain (1130) may include channel 11. In this case, the center frequency of channel 11 may be set to 2462 MHz. The fourth frequency domain (1140) may include channel 14. In this case, the center frequency of channel 14 may be set to 2484 MHz.

Figure 12 illustrates an example of channels used/supported/defined within the 5 GHz band.

The 5 GHz band may be referred to by other names, such as a second band/band, etc. The 5 GHz band may refer to a frequency range in which channels having a center frequency of 5 GHz or more but less than 6 GHz (or less than 5.9 GHz) are used/supported/defined. Alternatively, the 5 GHz band may include multiple channels between 4.5 GHz and 5.5 GHz. The specific figures shown in FIG. 12 may be subject to change.

Multiple channels within the 5 GHz band include Unlicensed National Information Infrastructure (UNII)-1, UNII-2, UNII-3, and ISM. UNII-1 may be referred to as UNII Low. UNII-2 may include frequency ranges referred to as UNII Mid and UNII-2Extended. UNII-3 may be referred to as UNII-Upper.

Within the 5 GHz band, multiple channels can be set, and the bandwidth of each channel can be variously set to 20 MHz, 40 MHz, 80 MHz, or 160 MHz. For example, the 5170 MHz to 5330 MHz frequency domain/range within UNII-1 and UNII-2 can be divided into eight 20 MHz channels. The 5170 MHz to 5330 MHz frequency domain/range can be divided into four channels through a 40 MHz frequency domain. The 5170 MHz to 5330 MHz frequency domain/range can be divided into two channels through an 80 MHz frequency domain. Alternatively, the 5170 MHz to 5330 MHz frequency domain/range can be divided into one channel through a 160 MHz frequency domain.

Figure 13 illustrates an example of channels used/supported/defined within the 6 GHz band.

The 6 GHz band may be referred to by other names such as the third band/band, etc. The 6 GHz band may refer to a frequency range in which channels with center frequencies higher than 5.9 GHz are used/supported/defined. The specific figures shown in Fig. 13 may be subject to change.

For example, the 20 MHz channel of Fig. 13 can be defined from 5.940 GHz. Specifically, the leftmost channel among the 20 MHz channels of Fig. 13 can have an index of 1 (or channel index, channel number, etc.), and a center frequency of 5.945 GHz can be assigned. That is, the center frequency of the index N channel can be determined as (5.940 + 0.005*N) GHz.

Accordingly, the indexes (or channel numbers) of the 20 MHz channels of FIG. 13 are 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 169, 173, 177, 181, 185, 189, 193, It can be 197, 201, 205, 209, 213, 217, 221, 225, 229, 233. Also, according to the above-mentioned (5.940 + 0.005*N) GHz rule, the indices of the 40 MHz channel in Fig. 13 can be 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227.

The MAC frame included in the data field of the PPDU of the present disclosure can be classified into various types. For example, the MAC frame of the present disclosure can be classified into a control frame, a management frame, and a data frame.

For example, the management frame includes Association Request, Association Response, Reassociation Request, Reassociation Response, Probe Request, Probe Response, Beacon, Disassociation, Authentication, and Deauthentication frames/signals defined in conventional WLAN. For the management frame, the values of the type fields (B3 and B2) of the MAC header are set to 00. In addition, the values of the subtype fields (B7, B6, B5, B4) of the MAC header are as follows: Association Request (0000), Association Response (0001), Reassociation Request (0010), Reassociation Response (0011), Probe Request (0100), Probe Response (0101), Beacon (1000), Disassociation (1010), Authentication (1011), Deauthentication (1100).

For example, the control frame includes Trigger Beamforming Report Poll, NDP Announcement (NDPA), Control Frame Extension, Control Wrapper, Block Ack Request (BlockAckReq), Block Ack (BlockAck), PS-Poll, RTS, CTS, Ack, CF-End frames/signals defined in conventional WLAN. For the control frame, the value of the type field (B3 and B2) of the MAC header is set to 01. Additionally, the values of the subtype fields (B7, B6, B5, B4) of the MAC header are as follows: Trigger (0010), Beamforming Report Poll (0100), NDP Announcement (0101), Control Frame Extension (0110), Control Wrapper (0111), BlockAckReq (1000), BlockAck (1001), PS-Poll (1010), RTS (1011), CTS (1100), Ack (1101), CF-End (1110).

For example, the data frame includes (QoS) Data, (QoS) Null, etc. defined in conventional WLAN. For the data frame, the value of the type field (B3 and B2) of the MAC header is set to 10.

A data frame may include an aggregated-control (A-Control) subfield. For example, a HT Control field included in a data frame may consist of 32 bits B0 to B31, and the A-Control subfield may consist of B2 to B31 of the HT Control field with B0 and B1 set to 1. In other words, the A-Control subfield may be 30-bit information.

The 30-bit A-Control subfield can have a structure like that in <Table 1> below:

Control List Padding

The bit size (or number of bits) of the Control List subfield can be variable. The bit size of the Padding can be 0 or more. The Control List can contain one or more Control subfields. Each Control subfield can have a structure as shown in Table 2 below:

Control ID Control Information

The bit size of the Control ID subfield can be 4 (e.g., B0 to B3). The bit size of the Control Information can be variable. The values of the Control ID subfield can be defined as shown in <Table 3> below:

Control ID value Meaning Length of the Control Information subfield (bits) 0 Triggered response scheduling (TRS) 26 1 Operating mode (OM) 12 2 HE link adaptation (HLA) 26 3 Buffer status report (BSR) 26 4 UL power headroom (UPH) 8 5 Bandwidth query report (BQR) 10 6 Command and status (CAS) 8 7-14 Reserved - 15 Ones need expansion surely (ONES) 26

The type of the MAC frame used in the present disclosure can be identified through the type field/information and the subtype field/information included in the frame control field of the header of the MAC frame (i.e., the MAC header). For example, the “trigger frame” of the present disclosure can mean a MAC frame in which the type bits B3 and B2 bits in the frame control field of the MAC header are set to 01, and the subtype bits B7, B6, B5, B4 bits in the frame control field are set to 0010. Various MAC frames described in the present disclosure are inserted/included in the data fields of various PPDUs (e.g., HE/VHT/HE/EHT/UHR PPDUs). Fig. 14 shows a trigger frame format. The trigger frame format may also be referred to as the structure of a trigger frame.

Referring to FIG. 14, a trigger frame may include a frame control field, a duration field, a receiver address (RA) field, a transmitter address (TA) field, a common info field, a user info list field, a padding field, and/or a frame check sequence (FCS) field. Optionally, the trigger frame may further include a special user info field between the common info field and the user info list field. The user info list field may include one or more user info fields. The frame control field, the duration field, the RA field, and the TA field may constitute a MAC header.

For example, the common information field may include a trigger type subfield. The trigger type subfield value may indicate a trigger frame variant as in <Table 4>:

Trigger type subfield value Trigger frame variant 0 Basic 1 Beamforming Report Poll (BFRP) 2 MU-BAR 3 MU-RTS 4 Buffer Status Report Poll (BSRP) 5 GCR MU-BAR 6 Bandwidth Query Report Poll (BQRP) 7 NDP Feedback Report Poll (NFRP) 8-15 Reserved

For example, if the value of the Trigger Type subfield is set to 0, the corresponding trigger frame may be a basic trigger frame. For example, if the value of the Trigger Type subfield is set to 3, the corresponding trigger frame may be a MU (multi-user) RTS trigger frame. Meanwhile, according to the EHT (i.e., 802.11be) standard, in order to support Peer-to-Peer (P2P) transmission to a non-AP STA, an AP may allocate a portion of the time interval within the TXOP acquired by the AP. In order to allocate a portion of the time interval within the TXOP, a TXOP Sharing Mode subfield may be defined in the Common Info Field of the MU-RTS trigger frame. When the value of the TXOP Sharing Mode subfield is non-zero, such MU-RTS trigger frame may be referred to as an MU-RTS TXOP Sharing (TXS) trigger frame (TF). The values of the TXOP Sharing Mode subfield are described in Table 5 below:

Triggered TXOP Sharing Mode subfield value Description 0 MU-RTS that does not initiate MU-RTS TXOP sharing procedure. 1 MU-RTS that initiates MU-RTS TXOP sharing procedure wherein a scheduledSTA can only transmit MPDU(s) addressed to its associated AP. 2 MU-RTS that initiates MU-RTS TXOP sharing procedure wherein a scheduled STA can transmit MPDU(s) addressed to its associated AP or addressed to another STA. 3 Reserved.

For example, if the value of the TXOP shared mode subfield is 1, one or more (non-TB) PPDU transmissions to the AP may be supported. If the value of the TXOP shared mode subfield is 2, not only (non-TB) PPDU transmissions to the AP but also P2P transmissions may be supported. In the present disclosure, the MU-RTS TXS TF may also be briefly referred to as a TXS trigger frame.

Figure 15 shows an example of the user information field format of MU-RTS TXS TF.

Referring to FIG. 15, the user information field may include an AID subfield, a RU allocation subfield, an allocation interval subfield, reserved bits, and/or a PS160 subfield.

The AID subfield may indicate the AID for the corresponding STA. The RU allocation subfield may indicate RU allocation for the corresponding STA.

= 8192us일 수 있다.The allocation interval subfield can contain 9 bits from B20 to B28 in the MU-RTS TXS TF and can indicate an allocation interval in 16us units. In this case, the maximum length of the allocation interval that can be indicated by the allocation interval subfield is

= It could be 8192us.

The PS160 subfield may indicate the primary 160 MHz channel or the second 160 MHz channel to which the RU or MRU allocation applies.

Figure 16 shows an example of operation when the value of the TXOP shared mode subfield is 2.

Referring to FIG. 16, an AP may transmit an MU-RTS TXS TF including allocation (time) interval information (e.g., Time allocated in MU-RTS TXS Trigger Frame) to non-AP STA 1. Non-AP STA 1 may transmit a CTS in response to the MU-RTS TXS TF and perform P2P transmission to non-AP STA 2.

Figure 17 illustrates an example of a procedure related to NAV setting.

Referring to FIG. 17, when a Source (e.g., AP STA/non-AP STA) that wants to transmit data transmits an RTS (request to send) frame to a Destination (e.g., AP STA/non-AP STA) that receives the data, the Destination can transmit a CTS (clear to send) frame to surrounding terminals to notify that it will receive the data. In other words, the Destination designated as a receiver through the RTS frame can transmit a CTS frame. When the Source that transmitted the RTS frame receives the CTS frame, the Source can start transmitting data to the Destination.

Meanwhile, if an STA other than the Destination designated as the receiver through the RTS frame receives the RTS frame, or if an STA other than the Source that transmitted the RTS frame receives a CTS frame, the STA may set a network allocation vector (NAV). An STA that has set a NAV may not transmit data during the NAV period, and thereby, the STA may avoid collisions between the STA and the Source/Destination. On the other hand, if the Destination designated as the receiver through the RTS frame receives the RTS frame, or if the Source that transmitted the RTS frame receives a CTS frame, the Source/Destination do not set a NAV.

If a CTS frame (e.g., PHY-RXSTART.indication primitive) is not received within a certain period from the time when the RTS frame is received (e.g., the time when the MAC receives the PHY-RXEND.indication primitive corresponding to the RTS frame), STAs that have set or updated the NAV through the RTS frame may reset (e.g., to 0) the NAV. The certain period may be (2*aSIFSTime + CTS_Time + aRxPHYStartDelay + 2*aSlotTime). The CTS_Time may be calculated based on the length of the CTS frame and the data rate indicated by the RTS frame.

In Fig. 17, for convenience, setting or updating NAV through RTS frame or CTS frame is illustrated, but NAV setting/resetting/updating may also be performed based on the ¡ field (e.g., duration field in MAC header of MAC frame) of various other frames, for example, non-HT PPDU, HT PPDU, VHT PPDU or HE PPDU. For example, if the RA field in the received MAC frame does not match its own address (e.g., MAC address), the STA may set/reset/update NAV according to the value of the duration field in the received MAC frame.

Non-AP STAs must maintain two NAVs, and APs can maintain two NAVs: Intra-BSS NAV and basic NAV. Intra-BSS NAV can be updated/set by PPDU within BSS. Basic NAV can be updated/set by inter-BSS PPDU, or PPDU that cannot be classified as inter-BSS or intra-BSS.

For example, a STA must classify a received PPDU as an inter-BSS PPDU if at least one of the following conditions is true:

- The PPDU carries a frame with a BSSID field whose value is not a BSSID of the BSS to which the STA is associated, or of another BSS in the same multi-BSSID set, or of a co-hosted BSSID set to which the BSS belongs, or of a wildcard BSSID; and/or

- The PPDU carries a frame without a BSSID field, but with both RA and TA fields, whose values are not all identical to the BSSID of the BSS to which the STA is associated, or of another BSS in the same multi-BSSID set, or in the co-hosted BSSID set to which the BSS belongs. The individual/group bits in the TA field are forced to 0 prior to comparison.

A STA shall classify a received PPDU as an intra-BSS PPDU if at least one of the following conditions is true:

- The PPDU carries a frame with the same RA, TA, or BSSID field value as the BSSID of the BSS or any BSS to which the STA is connected or of another BSS in the same multi-BSSID set or co-hosted BSSID set to which the BSS belongs. The individual/group bits in the TA field are forced to 0 before comparison; and/or

- The PPDU carries a control frame with a RA field value that matches the stored TXOP holder address of any BSS to which the BSS or STA is connected, or of another BSS in the same multi-BSSID set or in the co-hosting BSSID set to which the BSS belongs.

Otherwise, the PPDU cannot be judged as an Intra-BSS or Inter-BSS PPDU.

If the received PPDU satisfies both the Intra-BSS condition and the Inter-BSS condition based on the MAC address information of the frame contained in the received PPDU, the received PPDU is classified as an Intra-BSS PPDU.

Maintaining two NAVs is beneficial in dense deployment scenarios where an STA requires protection from frames transmitted by STAs within its own BSS (i.e., intra-BSS) and wants to avoid interference from frames transmitted by STAs in a neighboring BSS (i.e., inter-BSS). For example, in a TXOP initiated by an AP to which an STA is associated for TB PPDU transmission, the intra-BSS NAV of the STA may be set by the AP to prevent the STA from contending for the channel. Since an STA's default NAV is not updated/set by transmissions from the AP during a TXOP, if an STA receives a trigger frame from the AP with a CS (carrier sense) required subfield set to 1 and its default NAV is not 0, the STA does not respond.

The requirements of the CS mechanism apply to STAs that maintain two NAVs, except for the virtual CS indication of the medium. For STAs that maintain two NAVs, if both NAV timers are 0, the virtual CS indication means that the medium is idle. If at least one of the two NAV timers is not 0, the virtual CS indication means that the medium is busy.

STA shall update/set the intra-BSS NAV with the duration information indicated in the received frame of PSDU if all of the following conditions are met:

- The received frame is identified as intra-BSS;

- The indicated duration is greater than the current intra-BSS NAV value; and

- The RA of the received frame is not the MAC address of the STA. Or, the STA is not a TXOP holder and the PPDU carrying the frame does not contain a frame requesting an immediate response from the STA. Or, the STA is not a TXOP holder and the received frame is a trigger frame.

STA shall update/set the default NAV with the duration information indicated in the received frame of PSDU if all of the following conditions are met:

- The received frame is identified as inter-BSS, or cannot be identified as intra-BSS or inter-BSS;

- The indicated duration is greater than the current default NAV value; and

- The RA of the received frame is not the MAC address of the STA.

Meanwhile, a large number of APs are installed adjacent to each other to enable terminals to continuously maintain WLAN connections in a wider area, but issues such as radio interference and transmission collisions between APs may occur as the BSSs of multiple APs overlap. To solve these issues, various technologies related to coordination between APs in frequency, time, and spatial domains (e.g., RU selection, Joint transmission, Nulling) are being proposed, and various issues that may occur during cooperation between APs need to be addressed.

When the triggered TXOP sharing protocol is utilized for multi-AP coordination, each cooperative AP can perform frame exchange without affecting other cooperative APs by dividing transmissions within the BSS of each cooperative AP into time units.

Figure 18 shows an example of coordinated time division multiple access (C-TDMA) between cooperating APs.

For example, C-TDMA could mean that each cooperating AP exchanges frames without affecting other cooperating APs by separating transmissions within the BSS of each cooperating AP into time units.

When the triggered TXS protocol is applied to a multi-AP cooperative operation, an AP in the triggered TXS protocol may be an AP that shares a TXOP in the multi-AP cooperative operation, and an STA in the triggered TXS protocol may be an AP that shares a TXOP in the multi-AP cooperative operation. In the present disclosure, an AP that shares a TXOP may be referred to as a SAP (sharing AP), and an AP that receives a TXOP from a SAP may be referred to as a DAP (shared AP). Here, the name SAP does not limit that an entity that shares a TXOP is only an AP STA, and a SAP may also include a non-AP STA that shares a TXOP. In addition, the name DAP does not limit that an entity that shares a TXOP is only an AP STA, and a DAP may also include a non-AP STA that shares a TXOP (or performs transmission and reception with an AP STA that shares a TXOP). Additionally, frame exchange performed by a DAP with a non-AP STA or SAP belonging to the DAP BSS during the allocated time may be referred to as a BSS frame exchange (FE) of the DAP. For example, data frame transmission and block ACK frame response following RTS/CTS frame exchange between the DAP and a non-AP STA, UL data frame transmission of non-AP STAs by a trigger frame transmitted from the DAP, and/or data frame transmission of the DAP by a trigger frame transmitted from the SAP may be performed.

Figure 19 shows an example of a multi-AP cooperative topology.

Referring to FIG. 19, when a non-AP STA 2 connected to a DAP overhears a frame that the SAP transmits to the non-AP STA 1 and/or the DAP, the non-AP STA 2 can set a default NAV because the frame is not a frame for the non-AP STA 2. Thereafter, when the SAP shares a TXOP with the DAP to perform frame exchange between the DAP and the non-AP STA 2, the non-AP STA 2 may not transmit the UL PPDU/frame to the DAP due to the previously set default NAV.

Similarly, when a non-AP STA 2 connected to a DAP overhears a frame that a non-AP STA 1 connected to a SAP transmits to the SAP, the non-AP STA 2 can set a default NAV because the frame is not a frame for the non-AP STA 2. Later, when the SAP shares a TXOP with the DAP to perform frame exchange between the DAP and the non-AP STA 2, the non-AP STA 2 may not be able to transmit the UL PPDU/frame to the DAP due to the default NAV previously set by the non-AP STA 1.

Therefore, the present disclosure proposes a method for ignoring a default NAV that can be set for non-AP STAs associated with a DAP by frames transmitted from SAP or non-AP STAs associated with SAP in a multi-AP cooperation environment. Through the proposed method, non-AP STAs associated with a DAP can ignore the default NAV set by SAP or non-AP STAs associated with SAP, and transmit UL PPDU/frames to the DAP within the allocated time.

In this disclosure, the term “ignore” may be replaced with other terms having equivalent/similar meanings, such as “disregard”, “not consider”.

FIG. 20 illustrates an example of a method performed by a STA according to an embodiment of the present disclosure.

Referring to FIG. 20, in step S2001, the STA can detect (or overhear) a first frame that includes information about a second BSS color that is different from the first BSS color of the STA.

In step S2003, the STA may set the NAV based on identifying at least one of the RA or TA of the first frame. For example, the STA may set the NAV if i) the RA of the first frame is different from the address of the STA, and ii) the TA of the first frame is different from the address of the AP to which the STA is connected.

In step S2005, the STA can store information about the second BSS color.

In step S2007, the STA may receive a second frame including information of a cooperative AP for the AP from an AP connected to the STA. The information of the cooperative AP may include information about a BSS color of the cooperative AP.

In step S2009, the STA may ignore the NAV based on whether the second BSS color corresponds to the BSS color of the cooperating AP.

In step S2011, the STA can perform data transmission while ignoring the NAV.

According to various embodiments, the first BSS color may be associated with a BSS to which the AP and the STA connected to the AP belong. The second BSS color may be associated with a BSS to which at least one of the cooperating AP or the STA connected to the cooperating AP belongs.

According to various embodiments, the first frame may be transmitted from the cooperating AP. The NAV may be ignored based on i) that the TA of the first frame corresponds to an address of the cooperating AP included in the information of the cooperating AP, and ii) that the second BSS color included in the first frame corresponds to a BSS color of the cooperating AP.

According to various embodiments, the first frame may be transmitted from an STA associated with a cooperative AP. The NAV may be ignored based on: i) the RA of the first frame corresponds to an address of the cooperative AP included in the information of the cooperative AP, and ii) the second BSS color included in the first frame corresponds to a BSS color of the cooperative AP.

According to various embodiments, the NAV may be ignored from the time the second frame is received.

According to various embodiments, while NAV is ignored, the value of NAV can be greater than 0.

According to various embodiments, backoff for channel access may be omitted while NAV is ignored.

According to various embodiments, the cooperative AP may transmit a TXS trigger frame to the AP associated with the STA. The TXS trigger frame may include information about an allocation period for the AP within a TXOP duration. Within the allocation period, a second frame may be received by the STA, and data transmission by the STA may be performed.

According to various embodiments, the TXS trigger frame may include at least one of a multi-AP group identifier, an ID of an AP associated with the STA, capability information on whether a cooperating AP can share TXOPs, or operation signaling indicating whether the cooperating AP performs a TXOP sharing operation.

According to various embodiments, the first frame may be a TXS trigger frame transmitted from a cooperating AP.

According to various embodiments, the second frame may be a trigger frame for triggering the data transmission by the STA.

FIG. 21 illustrates an example of signal flow between a STA and an AP according to an embodiment of the present disclosure.

Referring to FIG. 21, in step S2101, the STA may detect (or overhear) a first frame that includes information about a second BSS color that is different from the first BSS color of the STA.

In step S2103, the STA may set the NAV based on identifying at least one of the RA or TA of the first frame. For example, the STA may set the NAV if i) the RA of the first frame is different from the address of the STA, and ii) the TA of the first frame is different from the address of the AP to which the STA is connected.

In step S2105, the STA can store information about the second BSS color.

In step S2107, the AP connected to the STA may transmit a second frame including information of a cooperative AP for the AP to the STA. The information of the cooperative AP may include information about a BSS color of the cooperative AP.

In step S2109, the STA may ignore the NAV based on whether the second BSS color corresponds to the BSS color of the cooperating AP.

In step S2111, an AP connected to a STA can receive data transmission from the STA while the NAV is ignored.

Below, a detailed implementation for ignoring NAV in a multi-AP cooperative environment is described.

STAs receiving a frame can set two NAVs: a default NAV and an intra-BSS NAV. The default NAV can be updated/set based on a PPDU identified as inter-BSS, or can be updated/set based on a PPDU that cannot be identified as intra-BSS or intra-BSS. The intra-BSS NAV can be updated/set based on a PPDU identified as intra-BSS. Specifically, in the C-TDMA operation according to the present disclosure, since FE is performed between a DAP and non-AP STAs connected to the DAP within a TXOP shared by the SAP, when the non-AP STAs connected to the DAP are in a position to overhear a frame transmitted by the SAP (or the non-AP STAs connected to the SAP), the default NAV can be set based on the entire TXOP period acquired by the SAP (or the duration value of the frame transmitted by the non-AP STAs connected to the SAP).

Within the TXOP acquired by SAP, channel access from STAs with NAV set (e.g., OBSS (overlapping BSS) AP and/or non-AP STA) can be blocked, so FE within BSS of SAP and FE with DAP can be effectively protected. However, this may cause an issue where non-AP STA connected to DAP cannot deliver UL PPDU/frame to DAP.

Each NAV ignoring method according to the present disclosure can solve an issue resulting from a NAV set by a SAP for a non-AP STA connected to a DAP in a C-TDMA operation in a multi-AP cooperation environment and/or an issue resulting from a NAV set by a non-AP STA for a non-AP STA connected to a DAP. For example, each NAV ignoring method according to the present disclosure can enable a non-AP STA connected to a DAP to ignore a default NAV that can be set by a SAP sharing a TXOP for a non-AP STA connected to a DAP so as to exchange frames with the DAP, and can enable a non-AP STA connected to a DAP to ignore a default NAV that can be set by a non-AP STA connected to a DAP so as to exchange frames with the DAP.

The present disclosure proposes methods for ignoring a default NAV that may be set to a non-AP STA associated with a DAP during a time shared by a SAP (e.g., an allocation interval indicated in the user information field of a TXS trigger frame) in a C-TDMA operation in a multi-AP cooperation environment.

Method 1) Implicit default NAV override method (based on AP-to-AP triggered TXS procedure)

A triggered TXS protocol can be utilized to perform FE by dividing transmissions within the BSS of each cooperative AP into time units and without affecting each other. That is, when the triggered TXS protocol is utilized in a multi-AP cooperative environment, the procedure presented in Fig. 15 can be applied similarly. Referring to the triggered TXS protocol of Fig. 15, when an AP transmits an MU-RTS TXS TF to a non-AP STA and receives a response thereto (e.g., a CTS frame), TXOP sharing occurs, and the non-AP STA that has shared the TXOP can perform FE during the allocation time included in the MU-RTS TXS TF (e.g., the allocation period of the user information field for the non-AP STA). When the triggered TXS protocol of Fig. 15 is applied to a multi-AP cooperation environment, the SAP transmits an MU-RTS TXS TF (or a control frame) to the DAP, and after the DAP transmits a response (e.g., a CTS frame), FE between the DAP and a non-AP STA can be performed during the allocated time (e.g., the allocated interval included in the user information field for the DAP).

Therefore, a rule can be added/defined that allows a non-AP connected to a DAP to overhear the FE process between the SAP and the DAP described above, and to ignore the default NAV (set by the SAP) set in the non-AP connected to the DAP when it recognizes the triggered TXS procedure.

Rules that allow (implicitly) overriding the default NAV may include one or more of the following methods:

Method 1.1) When a non-AP STA (associated with a DAP) that overhears an MU-RTS TXS TF transmitted (to a DAP) from an OBSS AP (e.g., SAP) and sets a default NAV and detects that the DAP associated with it responds (e.g., CTS frame) to the MU-RTS TXS TF after SIFS, the STA may assume the frame exchange between these two APs as a frame exchange for C-TDMA operation and ignore the currently set default NAV.

Method 1.2) When a non-AP STA (associated with a DAP) that has overheard a frame (e.g., a trigger frame, a control frame, a data frame, or a UM-RTS TXS TF) transmitted from an OBSS AP (e.g., SAP) and set a default NAV and detects that the DAP associated with it responds (e.g., a CTS frame) to the MU-RTS TXS TF transmitted from the same OBSS AP after SIFS, the STA may assume the frame exchange between these two APs as a frame exchange for C-TDMA operation and ignore the currently set default NAV.

On the other hand, in a scenario where the default NAV is set by frames transmitted from non-AP STAs connected to the SAP, it is difficult for the non-AP STAs connected to the DAP to roughly figure out the C-TDMA procedure because they can only detect frames transmitted from non-AP STAs connected to the DAP or the SAP. Therefore, a method may be considered in which the non-AP STAs connected to the DAP ignore the default NAV by utilizing information obtainable from the DAP or the SAP and/or the non-AP STAs connected to the SAP (i.e., an explicit default NAV ignore method).

Method 2) Explicitly ignore default NAV (based on AP-to-AP negotiation information)

For multi-AP cooperation, negotiation information can be exchanged between APs (e.g., SAP, DAP). For example, SAP can send a request frame for multi-AP cooperation to DAP, and DAP can send a response frame for multi-AP cooperation to SAP. In another example, DAP can send a request frame for multi-AP cooperation to SAP, and SAP can send a response frame for multi-AP cooperation to DAP.

For example, the request frame may be a cooperation request frame and/or a stream classification service (SCS) request frame. The response frame may be a cooperation response frame and/or an SCS response frame. The request frame and/or the response frame may include negotiation information.

Since the AID value in the user information field in the trigger frame is the AID used between the DAP and the non-AP STA, in order for the SAP to share TXOP with each DAP in the multi-AP cooperation, additional/new identifiers for the APs in the cooperation relationship may be required. Therefore, a method of defining a new ID and/or signaling that acts as an AID between the SAP and the DAP, or utilizing BSS color may be considered. For example, the new ID and signaling may be defined as follows, and an ID or signaling based on one or a combination of A, B, C, or D below may be included in the negotiation information:

A. Multi-AP Group ID : ID for the group of APs that make up the multi-AP collaboration (e.g. 0, 1, 2, ...).

B. DAP ID: ID assigned by SAP within the configured multi-AP group (e.g. 0, 1, 2, ...)

C. SAP Capability: Indicates the capability of the AP to operate as SAP.

For example, a QoS characteristic element included in a stream classification service (SCS) connection/response frame may be utilized. For example, reserved bits (e.g., 3 bits) in a control information field of a QoS characteristic element may be used. Specifically, 1-bit signaling for indicating SAP capability information among the reserved bits may be defined. When the bit value of the 1-bit signaling is 0, it may indicate that the corresponding AP cannot operate as a SAP. When the bit value of the 1-bit signaling is 1, it may indicate that the corresponding AP has the capability to operate as a SAP.

For example, the common information field included in the trigger frame may be utilized. For example, the (EHT) reserved bits (e.g., 7 bits) or the reserved bits (e.g., 4 bits) of the common information field may be utilized. Specifically, a new subfield for multi-AP cooperation may be defined utilizing the EHT reserved bits, and 1-bit signaling for indicating SAP capability information may be defined within the subfield. Specifically, 1-bit signaling for indicating SAP capability information may be defined utilizing the reserved bits within the common information field.

D. SAP Behavior Signaling: The AP can signal that it is currently operating as a SAP and can share TXOPs with the DAP.

For example, a QoS characteristic element included in a QoS data frame may be utilized. For example, a reserved bit (e.g., 3 bits) in a control information field of a QoS characteristic element may be used. Specifically, a 1-bit signaling may be defined among the reserved bits to indicate SAP operation signaling information. When the value of the 1-bit signaling is 0, it may indicate that the corresponding AP acts as a SAP but does not perform TXOP sharing. When the value of the 1-bit signaling is 1, it may indicate that the corresponding AP acts as a SAP and performs TXOP sharing to a DAP.

For example, the common information field included in the trigger frame may be utilized. For example, the (EHT) reserved bits (e.g., 7 bits) or the reserved bits (e.g., 4 bits) of the common information field may be utilized. Specifically, a new subfield for multi-AP cooperation may be defined by utilizing the EHT reserved bits, and 1-bit signaling may be defined in the subfield to indicate SAP operation signaling information. Specifically, 1-bit signaling may be defined to indicate SAP operation signaling information by utilizing the reserved bits in the common information field.

In addition to the information described above, i) MAC address (indicated by the RA field included in the MAC header of the frame) and/or ii) BSS color information may be included in the negotiation information.

The names of the IDs and/or signaling defined above may be changed, and in addition, capabilities and/or signaling based on multi-AP cooperation schemes (e.g., C-OFDMA, C-TDMA, Joint Beamforming) may exist/be included.

Additionally, information for multi-AP operation (e.g. channel information, buffers of DAP) may be present/included.

This negotiation information can be transmitted individually from each AP, included in the cooperation request/response frames (e.g., SCS request/response, A-control field) exchanged during the negotiation process between APs participating in multi-AP cooperation. Here, the cooperation request and response frames can be defined as new frames, or as new elements of existing request and response frames so that they can be transmitted together with existing request and response frames.

In addition to the inter-AP negotiation process, an announcement procedure may be required to allow non-AP STAs associated with each AP to obtain negotiation information (e.g., information from neighboring BSSs and/or information negotiated between APs).

For example, negotiation information (e.g., information from neighboring BSSs and/or information negotiated between APs) may be included in beacon frames transmitted periodically from the APs.

For example, in order to convey negotiation information (e.g., information of neighboring BSSs and/or information negotiated between APs) to non-AP STAs associated with each AP, negotiation information including an ID and/or signaling based on one or more combinations of the above-described common information field and/or user information field in the MU-RTS TXS TF transmitted by the SAP may be included.

For example, negotiation information including an ID and/or signaling based on one or more combinations of the above may be included within a trigger frame (or control frame/data frame) transmitted by the DAP during the allocated time (e.g., allocated interval) from the SAP.

That is, negotiation information (e.g., information of neighboring BSSs and/or information negotiated between APs) can be broadcast to non-AP STAs associated with each AP through reservation bits or new fields in frames transmitted during the existing (broadcast) process.

As another example, a method may be considered to convey negotiation information (e.g., information of neighboring BSSs and/or information negotiated between APs) to non-AP STAs within individual BSSs through a separate broadcast process, for which a new broadcast frame may be defined or a beacon frame may be utilized.

Accordingly, a non-AP STA associated with a DAP sharing TXOP can ignore a default NAV set for itself (e.g., a default NAV set by a SAP or non-AP STAs associated with the SAP) based on an ID and/or signaling based on one or more combinations described above. Hereinafter, in the C-TDMA operation, the RA value of the MU-RTS TXS TF (i.e., AP-to-AP trigger) transmitted from the SAP may be set to the MAC address of the DAP. Alternatively, the RA value of the MU-RTS TXS TF transmitted from the SAP may be set to broadcast, but the AID value in the user information field of the MU-RTS TXS TF may be set to the AID value of the corresponding DAP (e.g., a specific AID or DAP ID).

FIG. 22 illustrates a first example of a procedure for ignoring a default NAV that may be set by SAP according to an embodiment of the present disclosure.

Referring to Figure 22, a non-AP STA connected to a DAP can ignore the default NAV that can be set by the SAP.

For example, if a non-AP STA associated with a DAP overhears an MU-RTS TXS TF transmitted from a SAP that i) has the same group ID as the multi-AP group ID of the DAP associated with it and ii) has SAP capability and SAP operation signaling values enabled (i.e., a SAP that shares TXOP with the DAP), the non-AP STA associated with the DAP decodes the MU-RTS TXS TF transmitted from the SAP, and if it verifies that the MAC address indicated by the RA of the MU-RTS TXS TF is the MAC address of the DAP (or if it verifies that the AID value in the user information field of the MU-RTS TXS TF is set to the AID of the corresponding DAP (e.g., a specific AID or DAP ID)), the non-AP STA may ignore the default NAV set by the SAP at the time of receiving the MU-RTS TXS TF (① in FIG. 22).

For example, if a non-AP STA associated with a DAP i) overhears an MU-RTS TXS TF transmitted from a SAP (i.e., a SAP that shares TXOP with the DAP) that has a group ID that is the same as the multi-AP group ID of the DAP associated with it, ii) has SAP capability and SAP operation signaling values enabled (i.e., a SAP that shares TXOP with the DAP), and iii) detects that the DAP responds to the MU-RTS TXS TF (or transmits a CTS frame), the non-AP STA associated with the DAP decodes the MU-RTS TXS TF transmitted from the SAP to confirm that the MAC address indicated by the RA of the MU-RTS TXS TF is the MAC address of the DAP (or confirms that the AID value in the user information field of the MU-RTS TXS TF is set to the AID of the corresponding DAP (e.g., a specific AID or DAP ID), and at the time of detecting a response frame (or a CTS frame) from the DAP (② of FIG. 22), sets the default NAV set by the SAP. You can ignore it.

For example, if a non-AP STA associated with a DAP i) overhears an MU-RTS TXS TF transmitted from a SAP (i.e., a SAP that shares TXOP with the DAP) that has a group ID that is the same as the multi-AP group ID of the DAP associated with it, ii) has SAP capability and SAP operation signaling values enabled (i.e., a SAP that shares TXOP with the DAP), and iii) receives a trigger frame (or a control frame/data frame) transmitted after the DAP responds to the MU-RTS TXS TF (or transmits a CTS frame), the non-AP STA associated with the DAP decodes the MU-RTS TXS TF transmitted from the SAP to verify that the MAC address indicated by the RA of the MU-RTS TXS TF is the MAC address of the DAP (or verifies that the AID value in the user information field of the MU-RTS TXS TF is set to the AID of the corresponding DAP (e.g., a specific AID or DAP ID), and then detects a response frame (or a CTS frame) transmission from the DAP and then signals to itself, If the DAP ID value in the transmitted trigger frame matches the DAP ID value obtained from the MU-RTS TXS TF, the default NAV set by SAP at the time of receiving the trigger frame from the DAP (③ in Fig. 22) can be ignored.

FIG. 23 illustrates a second example of a procedure for ignoring a default NAV that may be set by SAP according to an embodiment of the present disclosure.

Referring to FIG. 23, a non-AP STA associated with a DAP that overhears a frame transmitted from a SAP (e.g., a trigger frame, a control frame, a data frame, and/or MU-RTS TXS TF) and sets a default NAV may decode the received frame to store information about multi-AP group ID, DAP ID, SAP capability and/or SAP operation signaling, as well as TA, RA and/or BSS color. The DAP may transmit a trigger frame (or a control frame/data frame) including an address of a SAP with which it shared TXOP and BSS color information to the non-AP STAs, and the non-AP STA that receives the trigger frame may compare it with the TA and BSS color information of the previously overheard frame, and if they match, the non-AP STA may ignore the default NAV by the SAP from the time of receiving the trigger frame transmitted from the DAP.

FIG. 24 illustrates an example of a procedure for ignoring a default NAV that may be set by a non-AP STA connected to a SAP according to an embodiment of the present disclosure. Hereinafter, in a C-TDMA operation, the RA value of an MU-RTS TXS TF (i.e., AP-to-AP trigger) transmitted from a SAP may be set to the MAC address of a DAP. Alternatively, the RA value of the MU-RTS TXS TF transmitted from the SAP may be set to broadcast, but the AID value in the user information field of the MU-RTS TXS TF may be set to the AID value of the corresponding DAP (e.g., a specific AID or DAP ID).

Referring to FIG. 24, a non-AP STA connected to a DAP that overhears frames transmitted from non-AP STAs connected to a SAP and sets a default NAV can decode the received frames and store information about TA, RA, and BSS color. The DAP can transmit a trigger frame (or a control frame/data frame) including an address of an SAP with which it shared TXOP and BSS color information to the non-AP STAs, and the non-AP STA that receives the trigger frame can compare it with the RA and BSS color information of the previously overheard frame, and if they match, the non-AP STA can ignore the default NAV by the non-AP STA connected to the SAP from the time of receiving the trigger frame transmitted from the DAP.

The technical features of the present disclosure described above can be applied to various devices and methods. For example, the technical features of the present disclosure described above can be performed/supported by the devices of FIG. 1 and/or FIG. 5. For example, the technical features of the present disclosure described above can be applied only to a part of FIG. 1 and/or FIG. 5. For example, the technical features of the present disclosure described above can be implemented based on the processing chip (114, 124) of FIG. 1, or implemented based on the processor (111, 121) and the memory (112, 122) of FIG. 1, or implemented based on the processor (510) and the memory (520) of FIG. 5.

For example, the processor (111), the processing chip (114) of FIG. 1, and/or the processor (510) of FIG. 5 may be configured to execute instructions stored in the memory (112, 520) to implement a method performed by the STA in the present disclosure. The method comprises: detecting a first frame including information about a second BSS color different from a first BSS (basic service set) color of the STA; setting a network allocation vector (NAV) based on identifying at least one of a receiver address (RA) or a transmitter address (TA) of the first frame; storing information about the second BSS color; receiving a second frame including information about a coordination AP (AP) for the AP from an access point (AP) connected to the STA, wherein the information about the coordination AP includes information about a BSS color of the coordination AP; and a step of ignoring the NAV based on the second BSS color corresponding to the BSS color of the cooperative AP; and a step of performing data transmission while ignoring the NAV.

For example, the processor (121) and/or the processing chip (124) of FIG. 1 may be configured to execute instructions stored in the memory (122) to implement a method performed by an AP in the present disclosure. The method includes: transmitting, to a station (STA) connected to the AP, a second frame including information of a coordination AP for the AP, wherein the information of the coordination AP includes information on a BSS color of the coordination AP; And a step of receiving data transmission from the STA, wherein the data transmission is performed while ignoring a network allocation vector (NAV) set in the STA, wherein the NAV is set based on identifying at least one of a receiver address (RA) or a transmitter address (TA) of a first frame including information about a second BSS color different from a first BSS (basic service set) color of the STA detected by the STA, and wherein the NAV is ignored based on the second BSS color corresponding to a BSS color of the cooperating AP.

The technical features of the present disclosure can be implemented based on a computer readable medium (CRM). For example, the CRM proposed by the present disclosure is at least one computer readable medium including instructions based on being executed by at least one processor.

For example, the CRM may be the memory (112) of FIG. 1, the memory (520) of FIG. 5, and/or a separate external memory/storage medium/disk. The CRM may store instructions for implementing a method performed by the STA in the present disclosure based on being executed by a processor (e.g., the processor (111) of FIG. 1, the processing chip (114) and/or the processor (510) of FIG. 5). The method comprises: detecting a first frame including information about a second BSS color different from a first BSS (basic service set) color of the STA; setting a network allocation vector (NAV) based on identifying at least one of a receiver address (RA) or a transmitter address (TA) of the first frame; storing information about the second BSS color; A method comprising: receiving a second frame including information of a coordinating AP for the AP from an access point (AP) connected to the STA, wherein the information of the coordinating AP includes information about a BSS color of the coordinating AP; and ignoring the NAV based on the second BSS color corresponding to the BSS color of the coordinating AP; and performing data transmission while ignoring the NAV.

For example, the CRM may be the memory (122) of FIG. 1 and/or a separate external memory/storage medium/disk. The CRM may store commands for implementing a method performed by an AP in the present disclosure based on being executed by a processor (e.g., the processor (121) and/or the processing chip (124) of FIG. 1). The method includes: a step of transmitting, to a STA (station) connected to the AP, a second frame including information of a coordination AP for the AP, wherein the information of the coordination AP includes information on a BSS color of the coordination AP; And a step of receiving data transmission from the STA, wherein the data transmission is performed while ignoring a network allocation vector (NAV) set in the STA, wherein the NAV identifies at least one of a receiver address (RA) or a transmitter address (TA) of a first frame including information about a second BSS color different from a first BSS (basic service set) color of the STA detected by the STA, and the NAV is ignored based on the second BSS color corresponding to a BSS color of the cooperative AP.

The technical features of the present disclosure described above can be applied to various applications or business models. For example, the technical features described above can be applied to wireless communication in a device supporting artificial intelligence (AI).

Artificial intelligence refers to a field that studies artificial intelligence or the methodologies for creating it, and machine learning refers to a field that defines various problems in the field of artificial intelligence and studies the methodologies for solving them. Machine learning is also defined as an algorithm that improves the performance of a task through constant experience with that task.

An artificial neural network (ANN) is a model used in machine learning, and can refer to a model with problem-solving capabilities that consists of artificial neurons (nodes) that form a network by combining synapses. An artificial neural network can be defined by the connection pattern between neurons in different layers, the learning process that updates model parameters, and the activation function that generates the output value.

An artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer may include one or more neurons, and the artificial neural network may include synapses connecting neurons. In an artificial neural network, each neuron may output a function value of an activation function for input signals, weights, and biases input through synapses.

Model parameters refer to parameters that are determined through learning, including the weights of synaptic connections and the biases of neurons. Hyperparameters refer to parameters that must be set before learning in machine learning algorithms, including learning rate, number of iterations, mini-batch size, and initialization functions.

The purpose of learning an artificial neural network can be seen as determining model parameters that minimize a loss function. The loss function can be used as an indicator to determine optimal model parameters during the learning process of an artificial neural network.

Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning depending on the learning method.

Supervised learning refers to a method of training an artificial neural network when labels for training data are given. The labels can refer to the correct answer (or result value) that the artificial neural network should infer when training data is input to the artificial neural network. Unsupervised learning can refer to a method of training an artificial neural network when labels for training data are not given. Reinforcement learning can refer to a learning method that trains an agent defined in a certain environment to select actions or action sequences that maximize cumulative rewards in each state.

Among artificial neural networks, machine learning implemented with a deep neural network (DNN: Deep Neural Network) that includes multiple hidden layers is also called deep learning, and deep learning is a part of machine learning. Hereinafter, machine learning is used to mean including deep learning.

Additionally, the above-described technical features can be applied to wireless communication of robots.

A robot can mean a machine that automatically processes or operates a given task by its own abilities. In particular, a robot that has the ability to recognize the environment, make judgments, and perform actions on its own can be called an intelligent robot.

Robots can be classified into industrial, medical, household, and military types depending on their intended use or field. Robots can perform various physical actions, such as moving robot joints, by having a drive unit that includes an actuator or motor. In addition, mobile robots have a drive unit that includes wheels, brakes, and propellers, and can drive on the ground or fly in the air through the drive unit.

Additionally, the above-described technical features can be applied to devices supporting extended reality.

Extended reality is a general term for virtual reality (VR), augmented reality (AR), and mixed reality (MR). VR technology provides real-world objects and backgrounds as CG images only, AR technology provides virtual CG images on top of real-world object images, and MR technology is a computer graphics technology that mixes and combines virtual objects in the real world.

MR technology is similar to AR technology in that it shows real objects and virtual objects together. However, there is a difference in that while AR technology uses virtual objects to complement real objects, MR technology uses virtual and real objects with equal characteristics.

XR technology can be applied to HMD (Head-Mount Display), HUD (Head-Up Display), mobile phones, tablet PCs, laptops, desktops, TVs, digital signage, etc., and devices to which XR technology is applied can be called XR devices.

The present disclosure may have various advantageous effects.

For example, the present disclosure proposes NAV ignoring methods to solve a problem in which a non-AP STA cannot transmit UL PPDU/frame to a DAP due to a default NAV set by a SAP and/or a non-AP STA connected to the SAP in a multi-AP cooperation environment. According to the proposed methods, a non-AP STA connected to a DAP can ignore the default NAV set for the non-AP STA and transmit UL PPDU/frame to the DAP.

The advantageous effects that can be obtained through specific embodiments of the present disclosure are not limited to the advantageous effects listed above. For example, there may be various technical effects that can be understood and/or derived from the present disclosure by those skilled in the art. Therefore, the specific effects of the present disclosure are not limited to those explicitly described herein, and may include various effects that can be understood or derived from the technical features of the present disclosure.

The claims set forth in this disclosure may be combined in various ways. For example, the technical features of the method claims of this disclosure may be combined and implemented as a device, and the technical features of the device claims of this disclosure may be combined and implemented as a method. In addition, the technical features of the method claims and the technical features of the device claims of this disclosure may be combined and implemented as a device, and the technical features of the method claims and the technical features of the device claims of this disclosure may be combined and implemented as a method.

Claims (20)

In a method performed by a STA (station) in a wireless local area network (LAN) system, A step of detecting a first frame including information on a second BSS color different from the first BSS (basic service set) color of the STA; A step of setting a network allocation vector (NAV) based on identifying at least one of a receiver address (RA) or a transmitter address (TA) of the first frame; A step of storing information about the second BSS color; A step of receiving a second frame including information of a coordination AP for the AP from an access point (AP) connected to the STA, wherein the information of the coordination AP includes information on a BSS color of the coordination AP; A step of ignoring the NAV based on the second BSS color corresponding to the BSS color of the cooperative AP; and A method comprising the step of performing data transmission while ignoring the above NAV. In claim 1, the first BSS color is related to the BSS to which the AP and the STA connected to the AP belong, The above second BSS color is a method related to a BSS to which at least one of the cooperative AP or STAs connected to the cooperative AP belongs. A method according to claim 1, wherein the information of the cooperative AP further includes information on an address of the cooperative AP. In claim 3, the first frame is transmitted from the cooperative AP, A method in which the NAV is ignored based on i) that the TA of the first frame corresponds to the address of the cooperating AP included in the information of the cooperating AP, and ii) that the second BSS color included in the first frame corresponds to the BSS color of the cooperating AP. In claim 3, the first frame is transmitted from a STA connected to the cooperative AP, A method in which the NAV is ignored based on i) that the RA of the first frame corresponds to the address of the cooperating AP included in the information of the cooperating AP, and ii) that the second BSS color included in the first frame corresponds to the BSS color of the cooperating AP. A method according to claim 1, wherein the NAV is ignored from the time the second frame is received. A method according to claim 1, wherein while the NAV is ignored, the value of the NAV is greater than 0. A method according to claim 1, wherein backoff for channel access is skipped while the NAV is ignored. In claim 1, the cooperative AP transmits a TXS (TXOP (transmission opportunity) sharing) trigger frame to the AP connected to the STA, The above TXS trigger frame includes information about the allocation duration for the AP within the TXOP duration, A method in which, within the above allocation interval, the second frame is received by the STA and the data transmission by the STA is performed. A method according to claim 9, wherein the TXS trigger frame includes at least one of a multi-AP group ID (identifier), an ID of the AP connected to the STA, capability information on whether the cooperative AP can share TXOP, or operation signaling indicating whether the cooperative AP performs a TXOP sharing operation. A method according to claim 9, wherein the first frame is a TXS trigger frame transmitted from the cooperative AP. A method according to claim 1, wherein the second frame is a trigger frame for triggering data transmission by the STA. In a wireless local area network (LAN) system, at a STA (station), Transmitter and receiver; memory; and At least one processor functionally coupled with the transceiver and the memory, The above memory stores instructions for performing operations based on being executed by the at least one processor, the operations being: An operation of detecting a first frame including information about a second BSS color that is different from the first BSS (basic service set) color of the STA; An operation of setting a network allocation vector (NAV) based on identifying at least one of a receiver address (RA) or a transmitter address (TA) of the first frame; An operation of storing information about the second BSS color; An operation of receiving a second frame including information of a coordination AP for the AP from an access point (AP) connected to the STA, wherein the information of the coordination AP includes information about a BSS color of the coordination AP; and An operation of ignoring the NAV based on the second BSS color corresponding to the BSS color of the cooperating AP; and An STA including an operation to perform data transmission while ignoring the above NAV. In a device configured to operate in a wireless local area network (LAN) system, at least one processor; and comprising at least one memory functionally coupled with at least one processor; The at least one memory stores instructions that perform operations based on being executed by the at least one processor, the operations comprising: An operation of detecting a first frame including information about a second BSS color that is different from the first BSS (basic service set) color of the STA; An operation of setting a network allocation vector (NAV) based on identifying at least one of a receiver address (RA) or a transmitter address (TA) of the first frame; An operation of storing information about the second BSS color; An operation of receiving a second frame including information of a coordination AP for the AP from an access point (AP) connected to the STA, wherein the information of the coordination AP includes information about a BSS color of the coordination AP; and An operation of ignoring the NAV based on the second BSS color corresponding to the BSS color of the cooperating AP; and A device comprising an operation for performing data transmission while ignoring the above NAV. A non-transitory computer readable medium (CRM) storing program code that implements instructions for performing operations based on being executed by at least one processor, said operations comprising: An operation of detecting a first frame including information about a second BSS color that is different from the first BSS (basic service set) color of the STA; An operation of setting a network allocation vector (NAV) based on identifying at least one of a receiver address (RA) or a transmitter address (TA) of the first frame; An operation of storing information about the second BSS color; An operation of receiving a second frame including information of a coordination AP for the AP from an access point (AP) connected to the STA, wherein the information of the coordination AP includes information about a BSS color of the coordination AP; and An operation of ignoring the NAV based on the second BSS color corresponding to the BSS color of the cooperating AP; and CRM including actions to perform data transfer while ignoring the above NAV. In a method performed by an access point (AP) in a wireless local area network (LAN) system, A step of transmitting a second frame including information of a coordinating AP for the AP to a STA (station) connected to the AP, wherein the information of the coordinating AP includes information about a BSS color of the coordinating AP; and A step of receiving data transmission from the above STA, The above data transmission is performed while ignoring the NAV (network allocation vector) set in the STA, The above NAV is set based on identifying at least one of a receiver address (RA) or a transmitter address (TA) of a first frame including information about a second BSS color different from a first BSS (basic service set) color of the STA detected by the STA, The above NAV is ignored based on whether the second BSS color corresponds to the BSS color of the cooperating AP. In a wireless local area network (LAN) system, at the access point (AP), Transmitter and receiver; memory; and At least one processor functionally coupled with the transceiver and the memory, The above memory stores instructions for performing operations based on being executed by the at least one processor, the operations being: An operation of transmitting a second frame including information of a coordinating AP for the AP to a STA (station) connected to the AP, wherein the information of the coordinating AP includes information about a BSS color of the coordinating AP; and An operation for receiving data transmission from the above STA, The above data transmission is performed while ignoring the NAV (network allocation vector) set in the STA, The above NAV is set based on identifying at least one of a receiver address (RA) or a transmitter address (TA) of a first frame including information about a second BSS color different from a first BSS (basic service set) color of the STA detected by the STA, The above NAV is an AP that is ignored based on whether the second BSS color corresponds to the BSS color of the cooperating AP. A method according to claim 17, wherein the information of the cooperative AP further includes information on an address of the cooperative AP. In claim 18, the first frame is transmitted from the cooperative AP, The NAV is an AP that is ignored based on i) the TA of the first frame corresponds to the address of the cooperating AP included in the information of the cooperating AP, and ii) the second BSS color included in the first frame corresponds to the BSS color of the cooperating AP. In claim 18, the first frame is transmitted from a STA connected to the cooperative AP, The NAV is an AP that is ignored based on i) the RA of the first frame corresponds to the address of the cooperating AP included in the information of the cooperating AP, and ii) the second BSS color included in the first frame corresponds to the BSS color of the cooperating AP.

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