Method and device for setting network allocation vector in wireless LAN system

Abstract

The present disclosure relates to setting a network allocation vector (NAV) in a wireless local area network (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 clear to send (CTS) frame for a transmission opportunity (TXOP) sharing (TXS) trigger frame including information about an allocation period within a TXOP period; identifying a value of a duration field of the CTS frame; and setting the NAV during the allocation period on the basis that the value of the duration field of the CTS frame is set to a value corresponding to the allocation period.

Description

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

[0001] The present disclosure relates to handling network allocation vector (NAV) settings in a wireless LAN system.

[0002] Next-generation Wi-Fi (e.g., IEEE 802.11be and / or later) aims to support ultra-high reliability when transmitting signals to STAs. To achieve this, various technologies are being considered to support high throughput, low latency, and extended range. For example, NAVs can be configured to protect frame exchanges between STAs and APs.

[0003] The present disclosure provides a method and device for processing NAV settings in a wireless LAN system.

[0004] According to an embodiment of the present disclosure, a method performed by a station (STA) in a wireless local area network (LAN) system includes the steps of: detecting a clear to send (CTS) frame for a TXOP sharing (TXS) trigger frame including information about an allocation period within a TXOP (transmission opportunity) period; identifying a value of a duration field of the CTS frame; and setting a network allocation vector (NAV) during the allocation period based on the value of the duration field of the CTS frame being set to a value corresponding to the allocation period.

[0005] 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: receiving a TXS (TXOP sharing) trigger frame including information on an allocation period within a TXOP (transmission opportunity) period; setting a value of a duration field of a CTS (clear to send) frame to a value corresponding to the allocation period; and transmitting the CTS (clear to send) frame in response to the TXS trigger frame.

[0006] In various embodiments, devices for implementing the above-described methods are provided.

[0007] The present disclosure may have various advantageous effects.

[0008] For example, in a TXOP sharing procedure based on C-TDMA, based on setting the duration field of the CTS frame to a specific value, OBSS STAs that do not participate in C-TDMA and can detect the CTS frame of the DAP may not set an unnecessary default NAV.

[0009] The beneficial effects that can be achieved through specific embodiments of the present disclosure are not limited to the beneficial effects listed above. For example, various technical effects may 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, but may include various effects that can be understood or derived from the technical features of the present disclosure.

[0010] FIG. 1 illustrates an example of a transmitting device and / or a receiving device of the present disclosure.

[0011] Figure 2 is a conceptual diagram showing the structure of a wireless local area network (WLAN).

[0012] Figure 3 is a diagram illustrating a general link setup process.

[0013] Figure 4 illustrates an embodiment of multi-link (ML).

[0014] FIG. 5 illustrates a modified example of a transmitting device and / or a receiving device of the present disclosure.

[0015] 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.

[0016] Figure 7 is a diagram showing the layout of resource units (RUs) used for 20MHz PPDU.

[0017] Figure 8 is a diagram showing the layout of resource units (RUs) used for 40MHz PPDU.

[0018] Figure 9 is a diagram showing the layout of resource units (RUs) used for 80MHz PPDU.

[0019] Figure 10 shows the operation according to UL-MU.

[0020] Figure 11 shows an example of channels used / supported / defined within the 2.4 GHz band.

[0021] Figure 12 illustrates an example of channels used / supported / defined within the 5 GHz band.

[0022] Figure 13 illustrates an example of channels used / supported / defined within the 6 GHz band.

[0023] Figure 14 shows the trigger frame format.

[0024] Figure 15 shows an example of the user information field format of MU-RTS TXS TF.

[0025] Figure 16 shows an example of operation when the value of the TXOP shared mode subfield is 2.

[0026] Figure 17 illustrates an example of a procedure related to NAV setting.

[0027] Figure 18 shows an example of coordinated time division multiple access (C-TDMA) between cooperating APs.

[0028] Figure 19 shows an example of a topology for STAs belonging to a BSS associated with C-TDMA and an OBSS not associated with C-TDMA.

[0029] Figure 20 shows an example of NAV settings for STAs in an OBSS that do not participate in C-TDMA.

[0030] FIG. 21 illustrates an example of a method performed by a STA according to an embodiment of the present disclosure.

[0031] FIG. 22 illustrates an example of a method performed by an AP according to an embodiment of the present disclosure.

[0032] FIG. 23 illustrates an example of setting a duration field in a CTS frame according to an embodiment of the present disclosure.

[0033] FIG. 24 illustrates an example of a C-TDMA procedure in which the duration field value of a CTS frame is set based on an allocation interval value according to an embodiment of the present disclosure.

[0034] 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.”

[0035] As used herein, a slash ( / ) or a comma 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."

[0036] In the present disclosure, “at least one of A and B” may mean “only A,” “only B,” or “both A and B.” Additionally, in the present disclosure, the expressions “at least one of A or B” or “at least one of A and / or B” may be interpreted identically to “at least one of A and B.”

[0037] In addition, parentheses used in the present disclosure may mean “for example.” Specifically, when “control information (UHR-Signal field)” is indicated, the “UHR-Signal field” may be suggested as an example of “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 suggested as an example of “control information.” In addition, even when indicated as “control information (UHR-Signal field),” the “UHR-Signal field” may be suggested as an example of “control information.”

[0038] Additionally, as used herein, “a / an” can mean “at least one” or “one or more.” Additionally, terms ending in “(s)” can mean “at least one” or “one or more.”

[0039] Additionally, the expressions “based on” or “on the basis of” or “according to” used in this disclosure mean “based at least in part on” and do not mean “based solely on.”

[0040] Technical features individually described in one drawing in this disclosure may be implemented individually or simultaneously.

[0041] 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 IEEE 802.11a / g / n / ac / ax / be / bn standards. Furthermore, the examples of the present disclosure can be applied to the Ultra High Reliability (UHR) standard or a next-generation wireless LAN standard that enhances IEEE 802.11bn. Furthermore, 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 Long Term Evolution (LTE) standard and its evolution based on the 3rd Generation Partnership Project (3GPP) standard.

[0042] In order to explain the technical features of the present disclosure, technical features to which the present disclosure can be applied are described below.

[0043] FIG. 1 illustrates an example of a transmitting device and / or a receiving device of the present disclosure.

[0044] 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 referred to 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 referred to by various names such as a network, a base station, a Node-B, an access point (AP), a repeater, a router, a relay, etc. The STA (110, 120) of the present disclosure may also be referred to by various names such as a receiving apparatus, a transmitting apparatus, a receiving STA, a transmitting STA, a receiving device, a transmitting device, etc.

[0045] For example, STA (110, 120) may perform the role of an AP (access point) or a non-AP role. That is, STA (110, 120) of the present disclosure may perform the functions of an AP and / or a non-AP. In the present disclosure, an AP may also be indicated as an AP STA.

[0046] 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 in 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 calls, video calls, data communications, and autonomous driving (Self-Driving, Autonomous-Driving).

[0047] In the present disclosure, STA (110, 120) may include a medium access control (MAC) and a physical layer interface for a wireless medium that follow the provisions of the IEEE 802.11 standard.

[0048] Based on the sub-drawing (a) of Fig. 1, STA (110, 120) is described as follows.

[0049] 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 a single chip.

[0050] 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.).

[0051] 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).

[0052] For example, the second STA (120) can perform the intended operation of a non-AP STA. For example, the transceiver (123) of the non-AP 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.).

[0053] 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).

[0054] 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, if 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 can 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 the transmission / reception signal of the AP can be stored in the memory (122) of the second STA (110).

[0055] For example, in the specification below, the operation of a device indicated as a non-AP (or User-STA) may be performed in the 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 the 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).

[0056] 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., PPPDU) 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 transmission / reception signal or performing data processing or operation in advance for a transmission / reception signal may include 1) an operation for determining / obtaining / configuring / computing / decoding / encoding bit information of a subfield (SIG, STF, LTF, Data) field included in a PPDU, 2) an operation for determining / configuring / obtaining 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 / obtaining a specific sequence (e.g., a pilot sequence, an STF / LTF sequence, an extra sequence 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 / obtaining / configuring / computing / decoding / encoding an ACK signal, etc. Additionally, in the examples below, various information (e.g., information related to fields / subfields / control fields / parameters / power, etc.) used by various STAs for determining / acquiring / configuring / computing / decoding / encoding transmission / reception signals can be stored in the memory (112, 122) of FIG. 1.

[0057] 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.

[0058] 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.

[0059] The mobile terminal, wireless device, Wireless Transmit / Receive Unit (WTRU), User Equipment (UE), Mobile Station (MS), Mobile Subscriber Unit, user, user STA, network, Base Station, Node-B, Access Point (AP), repeater, router, relay, receiving device, transmitting device, receiving STA, transmitting STA, receiving Device, transmitting Device, receiving Apparatus, and / or 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.

[0060] For example, the technical feature of a receiving STA receiving a control signal can be understood as a technical feature of a control signal being received by a transceiver (113, 123) illustrated in sub-drawing (a) of FIG. 1. Alternatively, the technical feature of a receiving STA receiving a control signal can be understood as a technical feature of a control signal received by a transceiver (113, 123) illustrated in sub-drawing (a) of FIG. 1 being acquired by a processor (111, 121) illustrated in sub-drawing (a) of FIG. 1. Alternatively, the technical feature of a receiving STA receiving a control signal can be understood as a technical feature of a control signal received by a transceiver (113, 123) illustrated in sub-drawing (b) of FIG. 1 being acquired by a processing chip (114, 124) illustrated in sub-drawing (b) of FIG.

[0061] 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.

[0062] The processor (111, 121) or 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 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 an enhanced processor thereof.

[0063] In the present disclosure, uplink may mean a link for communication from a non-AP STA to an AP STA, and uplink PPDU / packet / signal, etc. may be transmitted through the uplink. In addition, in the present disclosure, downlink may mean a link for communication from an AP STA to a non-AP STA, and downlink PPDU / packet / signal, etc. may be transmitted through the downlink.

[0064] Figure 2 is a conceptual diagram showing the structure of a wireless local area network (WLAN).

[0065] 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.

[0066] Referring to the top of FIG. 2, the wireless LAN system may include one or more infrastructure BSSs (200, 205) (hereinafter, BSS). The BSSs (200, 205) are a collection of APs and STAs, such as an access point (AP) 225 and a station (STA1, 200-1), that have successfully synchronized and can communicate with each other, and are not a concept that designates a specific area. The BSS (205) may also include one or more STAs (205-1, 205-2) that can be associated with one AP (230).

[0067] 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.

[0068] A distributed system (210) can connect multiple BSSs (200, 205) to implement an extended service set (ESS, 240). An ESS (240) can be used as a term to indicate a network formed by connecting one or more APs through the distributed system (210). APs included in a single ESS (240) can have the same SSID (service set identification).

[0069] 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).

[0070] 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).

[0071] The bottom of Figure 2 is a conceptual diagram showing IBSS.

[0072] Referring to the bottom of Fig. 2, the IBSS is a BSS that operates in ad-hoc mode. Since the IBSS does not include an AP, there is no centralized management entity. That is, in the IBSS, the STAs (250-1, 250-2, 250-3, 255-4, 255-5) are managed in a distributed manner. In the 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.

[0073] Figure 3 is a diagram illustrating a general link setup process.

[0074] In step S310, the STA may perform a network discovery operation. This network discovery operation may include scanning by the STA. That is, for the STA to access the network, it must find a network it can join. Before joining a wireless network, the STA must identify compatible networks. The process of identifying networks in a specific area is called scanning. Scanning methods include active scanning and passive scanning.

[0075] Figure 3 illustrates a network discovery operation that includes an active scanning process as an example. In active scanning, an STA performing scanning transmits a probe request frame to discover which APs exist in the vicinity while moving between channels and waits for a response. A responder transmits a probe response frame to the STA that transmitted the probe request frame in response to the probe request frame. Here, the responder may be the STA that last transmitted a beacon frame in the BSS of the channel being scanned. In a BSS, the AP transmits the beacon frame, so the AP becomes the responder. In an 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 requests / responses on channel 2) in the same manner.

[0076] Although not shown in the example of FIG. 3, the scanning operation can also be performed in a passive scanning manner. An STA performing scanning based on passive scanning can wait for a beacon frame while moving between channels. A beacon frame is one of the management frames in IEEE 802.11. It announces the presence of a wireless network and is periodically transmitted so that the scanning STA can find the wireless network and participate in the wireless network. In the BSS, the AP periodically transmits the beacon frame, and in the IBSS, the STAs within the IBSS take turns transmitting the beacon frame. When the scanning STA receives a beacon frame, it stores the information about the BSS included in the beacon frame and moves to another channel, recording the beacon frame information on each channel. An STA that receives a beacon frame can store the BSS-related information included in the received beacon frame, move to the next channel, and perform scanning on the next channel in the same manner.

[0077] An STA that discovers a network can perform an authentication process through step S320. This authentication process may be referred to as the first authentication process to clearly distinguish it from the security setup operation of step S340 described below. The authentication process of S320 may include a process in which the STA transmits an authentication request frame to the AP, and the AP responds by transmitting an authentication response frame to the STA. The authentication frame used for the authentication request / response corresponds to a management frame.

[0078] 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.

[0079] An STA can transmit an authentication request frame to an AP. The AP can determine whether to grant authentication to the STA based on the information contained in the received authentication request frame. The AP can provide the result of the authentication process to the STA via an authentication response frame.

[0080] 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 the AP transmits an association response frame to the STA in response. For example, the association request frame may include information related to various capabilities, such as a beacon listen interval, a service set identifier (SSID), supported rates, supported channels, RSN, mobility domain, supported operating classes, a Traffic Indication Map Broadcast request, and interworking service capabilities. 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.

[0081] In step S340, the STA may perform a security setup process. The security setup process of step S340 may include, for example, a process of setting up a private key through a four-way handshaking using an Extensible Authentication Protocol over LAN (EAPOL) frame.

[0082] Figure 4 illustrates an example of multi-link (ML).

[0083] As illustrated in FIG. 4, multiple multi-link devices (MLDs) can communicate over a remote link. The MLDs can be categorized into AP MLDs including multiple AP STAs and non-AP MLDs including multiple 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).

[0084] 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 (or other n bits). 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 second link may be configured in different bands.

[0085] The AP MLD of FIG. 4 includes three affiliated APs. In the example of FIG. 4, AP1 may operate in the 2.4 GHz band, AP2 may operate in the 5 GHz band, and AP3 may operate in the 6 GHz band. In the example of FIG. 4, the first link in which AP1 and non-AP1 operate may be defined as a channel / subchannel / frequency resource within the 2.4 GHz band. Furthermore, in the example of FIG. 4, the second link in which AP2 and non-AP2 operate may be defined as a channel / subchannel / frequency resource within the 5 GHz band. Furthermore, in the example of FIG. 4, the third link in which AP3 and non-AP3 operate may be defined as a channel / subchannel / frequency resource within the 6 GHz band.

[0086] In the example of FIG. 4, AP1 may initiate a multi-link setup procedure (ML setup procedure) by transmitting an Association Request frame to non-AP STA1. In the example of FIG. 4, non-AP STA1 may 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 the STA (i.e., user-STA or non-AP STA) illustrated in FIG. 1 and / or FIG. 2.

[0087] 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 defined in various ways, and multiple links can be defined in various ways within at least one band.

[0088] FIG. 5 illustrates a modified example of a transmitting device and / or a receiving device of the present disclosure.

[0089] 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 transceivers (113, 123) of FIG. 1. The transceiver (530) of FIG. 5 may include a receiver and a transmitter.

[0090] 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.

[0091] 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.

[0092] Referring to FIG. 5, a power management module (511) manages power to a processor (510) and / or a transceiver (530). A battery (512) supplies power to the power management module (511). A display (513) outputs results 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 or computer.

[0093] 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).

[0094] 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.

[0095] 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 may have, for example, the structure of FIG. 6. In addition, the PPDU described in the present disclosure may be called by various names such as a transmission PPDU, a reception PPDU, a first type PPDU, 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 upon IEEE 802.11bn.

[0096] The PPDU of FIG. 6 may be related 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 single-user (SU) mode / type / transmission, a multi-user (MU) mode / type / transmission, and a null data packet (NDP) mode / type / transmission related to channel sounding. For example, if the example of FIG. 6 is related to NDP, the Data field illustrated may be omitted. If the PPDU of FIG. 6 is used for a trigger-based (TB) 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.

[0097] In FIG. 6, L-STF or UHR-LTF may be called a preamble or physical preamble, and may be generated / transmitted / received / acquired / decoded in the physical layer (included in the transmitting / receiving STA).

[0098] 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.

[0099] The subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and UHR-SIG fields in 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.

[0100] In the PPDU of Fig. 6, L-LTF and L-STF may be identical to conventional fields (e.g., non-HT LTF and non-HT STF defined in conventional WLAN standards).

[0101] 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 or 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.

[0102] For example, (non-AP and AP) STAs 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 BCC coded bits. BPSK modulation can be applied to the 48 coded 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 {-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}.

[0103] 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. Receiving (non-AP and AP) STA can determine whether the received PPDU is a HE PPDU, EHT PPDU, or UHR PPDU based on the presence of RL-SIG. In other words, if RL-SIG is present, receiving (non-AP and AP) STA can determine whether the received PPDU is one of HE PPDU, EHT PPDU, or UHR PPDU. In other words, if RL-SIG is not present, receiving (non-AP and AP) STA can determine whether the received PPDU is one of non-HT PPDU, HT PPDU, or VHT PPDU. 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.

[0104] 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.

[0105] A U-SIG can contain N bits of information and can include information for identifying the type of EHT PPDU. For example, a U-SIG can be formed based on two symbols (e.g., two consecutive OFDM symbols). Each symbol (e.g., an OFDM symbol) for a U-SIG can have a duration of 4 microseconds. Each symbol of a U-SIG can be used to transmit 26 bits of information. For example, each symbol of a U-SIG can be transmitted and received based on 52 data tones and 4 pilot tones.

[0106] For example, A bit information (e.g., 52 uncoded bits) can be transmitted through U-SIG, and the first symbol of U-SIG can transmit the first X bits of information (e.g., 26 uncoded 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 uncoded bits) out of the total A bit information. For example, the transmitting STA can obtain 26 uncoded 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.

[0107] For example, A bit information (e.g., 52 uncoded bits) transmitted by U-SIG may include a CRC field (e.g., a 4-bit long field) and a tail field (e.g., a 6-bit long field). The CRC field and the tail field may be transmitted through the 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 the trellis of the convolutional decoder and may be set to, for example, "000000".

[0108] 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.

[0109] For example, the version-independent bits of the 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 the transmitted and 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 and received PPDU is an EHT PPDU. In addition, a second value (e.g., a value of 001) of the 3-bit PHY version identifier may indicate that the transmitted and received PPDU is an UHR PPDU.

[0110] In other words, when the (AP / non-AP) STA transmits an EHT PPDU, it can set the 3-bit PHY version identifier 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 an UHR PPDU based on the PHY version identifier having the second value.

[0111] 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.

[0112] 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.

[0113] For example, if a UHR PPDU is classified into various types (e.g., a type related to SU transmission (performed based on UL or DL), a type related to DL transmission, a type related to NDP transmission, a type related to DL non-MU-MIMO, a type related to DL MU-MIMO, a type related to Multi-AP operation, a type related to CBF (Coordinated beamforming), SR (Spatial Reuse), a type related to C-OFDMA (Coordinated OFDMA), a 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.

[0114] For example, a U-SIG may include information about 1) a bandwidth field including information about a bandwidth, 2) a field including information about a Modulation and Coding Scheme (MCS) technique applied to the UHR-SIG, 3) an indication field including information about whether a dual subcarrier modulation (DCM) technique is applied to the UHR-SIG, 4) a field including information about the number of symbols used for the UHR-SIG, 5) a field including information about whether the UHR-SIG is generated over the entire band, 6) a field including information about the type of UHR-LTF / STF, and 7) a field indicating the length of the UHR-LTF and the CP length.

[0115] Preamble puncturing may be applied to the PPDU of FIG. 6. Preamble puncturing refers to applying puncturing to a portion of the entire bandwidth of the PPDU (e.g., the secondary 20 MHz band). For example, when an 80 MHz PPDU is transmitted, the STA may apply puncturing to the secondary 20 MHz band within the 80 MHz band, and transmit the PPDU only through the primary 20 MHz band and the secondary 40 MHz band.

[0116] For example, the pattern of preamble puncturing can be preset. For example, when the first puncturing pattern is applied, puncturing can be applied only to the secondary 20 MHz band within the 80 MHz band. For example, when the second puncturing pattern is applied, puncturing can be applied only to one of the two secondary 20 MHz bands included in the secondary 40 MHz band within the 80 MHz band. For example, when the third puncturing pattern is applied, puncturing can be applied only to the secondary 20 MHz band included in the primary 80 MHz band within the 160 MHz band (or 80+80 MHz band). For example, when the fourth 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) may be present, and puncturing may be applied to at least one 20 MHz channel that does not belong to the primary 40 MHz band.

[0117] Information regarding preamble puncturing applied to the PPDU may be included in the U-SIG and / or UHR-SIG. For example, the first field of the U-SIG may include information regarding the contiguous bandwidth of the PPDU, and the second field of the U-SIG may include information regarding preamble puncturing applied to the PPDU.

[0118] 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, the U-SIG 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 the first 80 MHz band and a second U-SIG for the 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 the 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).

[0119] Additionally or alternatively, U-SIG and UHR-SIG may include information regarding preamble puncturing based on the following methods. U-SIG may include information regarding preamble puncturing for all bands (i.e., information regarding preamble puncturing patterns). That is, UHR-SIG may not include information regarding preamble puncturing, and only U-SIG may include information regarding preamble puncturing (i.e., information regarding preamble puncturing patterns).

[0120] U-SIGs can be configured in 20 MHz units. For example, if an 80 MHz PPDU is configured, U-SIGs can be duplicated. That is, four identical U-SIGs can be included within an 80 MHz PPDU. PPDUs exceeding the 80 MHz bandwidth can contain different U-SIGs.

[0121] The UHR-SIG of FIG. 6 may include control information for a receiving STA. The UHR-SIG may be transmitted via at least one symbol, and each symbol may have a length of 4 us. Information regarding the number of symbols used for the UHR-SIG may be included in the U-SIG.

[0122] 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).

[0123] 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.

[0124] FIG. 7 is a diagram showing the layout of resource units (RUs) used for a 20 MHz PPDU. That is, the UHR-LTF, UHR-STF, and / or data fields included in the 20 MHz PPDU can be transmitted / received through at least one of the various RUs defined in FIG. 7.

[0125] As shown at 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 20 MHz band, and five tones can be used as a guard band in the rightmost band of the 20 MHz 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 each side of the DC band. 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.

[0126] 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.

[0127] In the example of Fig. 7, RUs of various sizes, such as 26-RU, 52-RU, 106-RU, and 242-RU, are proposed. 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.

[0128] Figure 8 is a diagram showing the layout of resource units (RUs) used for 40MHz PPDU.

[0129] 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, 5 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.

[0130] Additionally, as illustrated, 484 RUs may be used when used for a single user. Meanwhile, the specific number of RUs may be changed, as in the example of FIG. 7.

[0131] Figure 9 is a diagram illustrating the layout of resource units (RUs) used for an 80MHz PPDU. The layout of the resource units (RUs) used in the present disclosure may vary. For example, the layout of the resource units (RUs) used in the 80MHz band may vary.

[0132] Figure 10 illustrates an operation according to UL-MU. As illustrated, a transmitting STA (e.g., AP) can acquire 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) can 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.

[0133] TB PPDUs (1041, 1042) are transmitted at the same time 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 the TB PPDU can be implemented in various forms. For example, the ACK frame (1050) for the TB PPDU can be implemented in the form of a BA (block ACK).

[0134] In FIG. 10, transmission(s) of a Trigger Frame (1030), a TB PPDU (1041, 1042) and / or an ACK frame (1050) may be performed within a TXOP (1025).

[0135] Figure 11 shows an example of channels used / supported / defined within the 2.4 GHz band.

[0136] The 2.4 GHz band may be referred to by other names, such as the first band (band). Furthermore, the 2.4 GHz band may refer to a frequency range in which channels with a center frequency adjacent to 2.4 GHz (e.g., channels with a center frequency between 2.4 and 2.5 GHz) are used / supported / defined.

[0137] The 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 through 14). For example, the center frequency of a 20 MHz channel assigned channel index 1 may be 2.412 GHz, the center frequency of a 20 MHz channel assigned channel index 2 may be 2.417 GHz, and the center frequency of a 20 MHz channel assigned channel index N may be (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.

[0138] Figure 11 exemplarily illustrates four channels within the 2.4 GHz band. The illustrated first frequency region (1110) to fourth frequency region (1140) may each include one channel. For example, the first frequency region (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 region (1120) may include channel 6. In this case, the center frequency of channel 6 may be set to 2437 MHz. The third frequency region (1130) may include channel 11. In this case, the center frequency of channel 11 may be set to 2462 MHz. The fourth frequency region (1140) may include channel 14. In this case, the center frequency of channel 14 may be set to 2484 MHz.

[0139] Figure 12 illustrates an example of channels used / supported / defined within the 5 GHz band.

[0140] 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 with center frequencies greater than or equal to 5 GHz and 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 are subject to change.

[0141] 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 called UNII Mid and UNII-2Extended. UNII-3 may be referred to as UNII-Upper.

[0142] Within the 5 GHz band, multiple channels can be configured, and the bandwidth of each channel can be variously configured, such as 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.

[0143] Figure 13 illustrates an example of channels used / supported / defined within the 6 GHz band.

[0144] The 6 GHz band may also be referred to by other names, such as the third band / band. The 6 GHz band may refer to the frequency range in which channels with center frequencies above 5.9 GHz are used / supported / defined. The specific figures shown in Figure 13 are subject to change.

[0145] 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 indexed channel N can be determined as (5.940 + 0.005*N) GHz.

[0146] 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 (5.940 + 0.005*N) GHz rule mentioned above, the indices of the 40 MHz channels 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.

[0147] The MAC frames included in the data field of the PPDU of the present disclosure can be classified into various types. For example, the MAC frames of the present disclosure can be classified into a control frame, a management frame, and a data frame.

[0148] 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).

[0149] 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, and 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).

[0150] 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.

[0151] 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 bits 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 bits of information.

[0152] The 30-bit A-Control subfield can have a structure as shown in Table 1 below:

[0153] Control ListPadding

[0154] 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. A Control List can contain one or more Control subfields. Each Control subfield can have a structure as shown in Table 2 below:

[0155] Control IDControl Information

[0156] 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 below:

[0157] Control ID valueMeaningLength of the Control Information subfield (bits)0Triggered response scheduling (TRS)261Operating mode (OM)122HE link adaptation (HLA)263Buffer status report (BSR)264UL power headroom (UPH)85Bandwidth query report (BQR)106Command and status (CAS)87-14Reserved-15Ones need expansion surely (ONES)26

[0158] 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 may 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, and B4 bits in the frame control field are also 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 the trigger frame.

[0159] Referring to FIG. 14, a trigger frame may include a frame control field, a duration / ID 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 / ID field, the RA field, and the TA field may constitute a MAC header.

[0160] For example, the common information field may include a trigger type subfield. The trigger type subfield value may indicate a trigger frame variant, as shown in Table 4:

[0161] Trigger type subfield valueTrigger frame variant0Basic1Beamforming Report Poll (BFRP)2MU-BAR3MU-RTS4Buffer Status Report Poll (BSRP)5GCR MU-BAR6Bandwidth Query Report Poll (BQRP)7NDP Feedback Report Poll (NFRP)8-15Reserved

[0162] For example, if the value of the trigger type subfield is set to 0, the trigger frame may be a basic trigger frame. For example, if the value of the trigger type subfield is set to 3, the trigger frame may be a multi-user (MU) RTS trigger frame. Meanwhile, according to the EHT (i.e., 802.11be) standard, in order to support peer-to-peer (P2P) transmission to non-AP STAs, 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 within the Common Info Field of the MU-RTS trigger frame. When the value of the TXOP Sharing Mode subfield is non-zero, such an 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:

[0163] Triggered TXOP Sharing Mode subfield valueDescription0MU-RTS that does not initiate MU-RTS TXOP sharing procedure.1MU-RTS that initiates MU-RTS TXOP sharing procedure wherein a scheduledSTA can only transmit MPDU(s) addressed to its associated AP.2MU-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.3Reserved.

[0164] 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.

[0165] Figure 15 shows an example of the user information field format of MU-RTS TXS TF.

[0166] Referring to FIG. 15, the user information field may include an AID subfield, an RU allocation subfield, an allocation interval subfield, reserved bits, and / or a PS160 subfield.

[0167] The AID subfield may indicate the AID for the corresponding STA. The RU allocation subfield may indicate RU allocation for the corresponding STA.

[0168] The allocation interval subfield can contain 9 bits from B20 to B28 in the MU-RTS TXS TF and can indicate the 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.

[0169] The PS160 subfield may indicate the primary 160MHz channel or the second 160MHz channel to which RU or MRU allocation applies.

[0170] Figure 16 shows an example of operation when the value of the TXOP shared mode subfield is 2.

[0171] 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.

[0172] Figure 17 illustrates an example of a procedure related to NAV setting.

[0173] 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 notify surrounding terminals that it will receive the data by transmitting a CTS (clear to send) frame. In other words, the Destination designated as a receiver through the RTS frame can transmit a CTS frame. If the Source that transmitted the RTS frame receives the CTS frame, the Source can start transmitting data to the Destination.

[0174] 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 the 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, thereby avoiding 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 the CTS frame, the Source / Destination does not set a NAV.

[0175] 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 the NAV (e.g., 0). 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.

[0176] 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 based on the value of the duration field in the received MAC frame.

[0177] Non-AP STAs must maintain two NAVs, and APs can maintain two NAVs: an intra-BSS NAV and a basic NAV. The intra-BSS NAV can be updated / set by PPDUs within the BSS. The basic NAV can be updated / set by inter-BSS PPDUs, or PPDUs that cannot be classified as inter-BSS or intra-BSS.

[0178] For example, an STA must classify a received PPDU as an inter-BSS PPDU if at least one of the following conditions is true:

[0179] - The PPDU carries a frame with a BSSID field whose value is not a BSSID of the BSS to which the STA is connected, 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

[0180] - 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 connected, 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 before comparison.

[0181] An STA shall classify a received PPDU as an intra-BSS PPDU if at least one of the following conditions is true:

[0182] - 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

[0183] - The PPDU carries a control frame with no TA field and an 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.

[0184] Otherwise, the PPDU cannot be determined as an Intra-BSS or Inter-BSS PPDU.

[0185] If the received PPDU satisfies both the Intra-BSS condition and the Inter-BSS condition based on the MAC address information of the frame included in the received PPDU, the received PPDU is classified as an Intra-BSS PPDU.

[0186] 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 neighboring BSSs (i.e., inter-BSS). For example, in a TXOP initiated by an AP to which an STA is associated for TB PPDU transmission, the STA's intra-BSS NAV 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's default NAV is not 0 and the STA receives a trigger frame from the AP with the CS (carrier sense) required subfield set to 1, the STA does not respond.

[0187] The CS mechanism requirements apply to STAs that maintain two NAVs, excluding the virtual CS indication on the medium. For STAs that maintain two NAVs, if both NAV timers are 0, the virtual CS indication indicates that the medium is idle. If at least one of the two NAV timers is non-zero, the virtual CS indication indicates that the medium is busy.

[0188] The STA shall update / set the intra-BSS NAV with the duration information indicated in the received frame of the PSDU if all of the following conditions are met:

[0189] - The received frame is identified as intra-BSS;

[0190] - The indicated duration is greater than the current intra-BSS NAV value; and

[0191] - 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.

[0192] The STA must update / set the default NAV with the duration information indicated in the received frame of the PSDU if all of the following conditions are met:

[0193] - The received frame is identified as inter-BSS, or cannot be identified as intra-BSS or inter-BSS;

[0194] - The indicated duration is greater than the current default NAV value; and

[0195] - The RA of the received frame is not the MAC address of the STA.

[0196] Meanwhile, to enable terminals to maintain continuous WLAN connectivity over a wider area, numerous APs are being installed adjacent to each other. However, overlapping BSSs of multiple APs can lead to issues such as radio interference and transmission collisions between APs. To address these issues, various technologies related to coordination between APs in the frequency, time, and spatial domains (e.g., RU selection, joint transmission, nulling) have been proposed. Furthermore, various issues that may arise during inter-AP cooperation need to be addressed.

[0197] When the triggered TXOP sharing protocol is utilized for multi-AP coordination, transmissions within the BSS of each cooperative AP are divided into time units, so that each cooperative AP can perform frame exchange without affecting other cooperative APs.

[0198] Figure 18 shows an example of coordinated time division multiple access (C-TDMA) between cooperating APs.

[0199] 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.

[0200] 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 term SAP does not limit that the 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 term DAP does not limit that the 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 exchanges 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 in response to a trigger frame transmitted from the DAP, and / or data frame transmission of the DAP in response to a trigger frame transmitted from the SAP may be performed.

[0201] Figure 19 shows an example of a topology for STAs belonging to a BSS associated with C-TDMA and an OBSS not associated with C-TDMA.

[0202] Referring to Fig. 19, in C-TDMA operation, an entity sharing a TXOP (i.e., SAP) and an entity receiving a TXOP (i.e., DAP) may be associated with different BSSs. Therefore, adjacent OBSS STAs that receive frames transmitted during FE processes between SAP and DAP may set NAVs. In particular, in a topology such as Fig. 19, STAs belonging to an OBSS that detect a response frame (e.g., CTS or Ack frame) to an MU-RTS TXS TF (or control frame) transmitted from a SAP may set a default NAV until the end of the entire TXOP period acquired by the SAP. Therefore, STAs belonging to the OBSS may not perform FE even if the time allocated to the DAP ends.

[0203] Figure 20 shows an example of NAV settings for STAs in an OBSS that do not participate in C-TDMA.

[0204] Referring to FIG. 20, when a SAP shares a TXOP with a DAP in a C-TDMA procedure, the SAP may include the time until the end of the TXOP period of the TXOP acquired by the SAP in the Duration / ID field of the MU-RTS TXS TF and transmit such MU-RTS TXS TF. The DAP that receives the MU-RTS TXS TF may include the time from the end of reception of the PPDU including the MU-RTS TXS TF until the end of the TXOP period of the SAP in the Duration field of the CTS frame and transmit such CTS frame. STAs in the OBSS that detect the CTS frame transmitted from the DAP may set the default NAV by the value of the Duration field included in the CTS frame. That is, only OBSS STAs that overlap with a DAP may not perform FE for the remaining TXOP period of SAP by default NAV set by the DAP, even if the time to which the DAP was allocated (i.e., the allocation period indicated by the user information field for the DAP in the MU-RTS TXS TF) expires.

[0205] Accordingly, the present disclosure provides a method and apparatus for resolving a basic NAV setting issue that may occur in OBSS STAs that detect a CTS frame transmitted from a DAP in a TXOP sharing procedure based on C-TDMA.

[0206] According to various embodiments of the present disclosure, based on setting the duration field of the CTS frame to a specific value in a TXOP sharing procedure based on C-TDMA, OBSS STAs that do not participate in C-TDMA and can detect the CTS frame of the DAP may not set an unnecessary default NAV.

[0207] In this disclosure, specific designations (names) may be changed, and embodiments of the present disclosure are not limited to such specific designations (names).

[0208] FIG. 21 illustrates an example of a method performed by a STA according to an embodiment of the present disclosure.

[0209] Referring to FIG. 21, in step S2101, the STA can detect a CTS frame for a TXS trigger frame that includes information about an allocated section within a TXOP section.

[0210] In step S2103, the STA can identify the value of the duration field of the CTS frame.

[0211] In step S2105, the STA may set the NAV during the allocation interval based on the value of the duration field of the CTS frame being set to a value corresponding to the allocation interval.

[0212] According to various embodiments, the value of the duration field of the TXS trigger frame is set to a value corresponding to the TXOP period. The value of the duration field of the CTS frame may be different from the value of the duration field of the TXS trigger frame.

[0213] According to various embodiments, the value of the Duration field of the TXS trigger frame may indicate the end point of the TXOP interval. The value of the Duration field of the CTS frame may indicate the end point of the allocation interval.

[0214] According to various embodiments, the allocation interval may include a time interval allocated to the AP within a TXOP interval. Information about the allocation interval may be included in the user information field for the AP in the TXS trigger frame.

[0215] According to various embodiments, during the allocation period, an STA with a NAV set may skip frame exchange, and an AP may perform frame exchange with an STA connected to the AP.

[0216] According to various embodiments, the BSS to which the AP belongs may be different from the BSS to which the STA belongs.

[0217] According to various embodiments, the STA may perform frame exchange after the NAV expires within the TXOP period. The NAV may expire at the end of the allocated period.

[0218] FIG. 22 illustrates an example of a method performed by an AP according to an embodiment of the present disclosure.

[0219] Referring to FIG. 22, in step S2201, the AP may receive a TXS trigger frame including information about an allocation interval within a TXOP interval.

[0220] In step S2203, the AP may set the value of the duration field of the CTS frame to a value corresponding to the allocated interval.

[0221] In step S2205, the AP may transmit a CTS frame in response to the TXS trigger frame.

[0222] According to various embodiments, the value of the duration field of the TXS trigger frame may be set to a value corresponding to the TXOP period. The value of the duration field of the CTS frame may be different from the value of the duration field of the TXS trigger frame.

[0223] According to various embodiments, the value of the Duration field of the TXS trigger frame may indicate the end point of the TXOP interval. The value of the Duration field of the CTS frame may indicate the end point of the allocation interval.

[0224] According to various embodiments, the allocation interval may include a time interval allocated to the AP within a TXOP interval. Information about the allocation interval may be included in the user information field for the AP in the TXS trigger frame.

[0225] According to various embodiments, based on the CTS frame being detected by the STA, the STA may set the NAV during the allocation interval.

[0226] According to various embodiments, an STA with a NAV set during an allocation period may skip frame exchange, and an AP may perform frame exchange with an STA connected to the AP.

[0227] According to various embodiments, the BSS to which the AP belongs may be different from the BSS to which the STA belongs.

[0228] According to various embodiments, the STA may perform frame exchange after the NAV expires within the TXOP period. The NAV may expire at the end of the allocated period.

[0229] Below, detailed implementations are described to prevent OBSS STAs that detect a CTS frame transmitted from a DAP in a TXOP sharing procedure based on C-TDMA from setting an unnecessary default NAV.

[0230] In a TXOP sharing procedure based on C-TDMA according to the present disclosure, the value of the duration field in the CTS frame of the DAP for the MU-RTS TXS TF transmitted by the SAP may be set based on the value of the allocation interval subfield included in the user information field in the MU-RTS TXS TF. That is, the DAP may set the duration field value of the CTS frame for the response of the MU-RTS TXS TF to a time corresponding to the allocation interval allocated by the SAP, rather than the time until the end of the TXOP interval of the TXOP acquired by the SAP, based on the value of the duration / ID field in the MU-RTS TXS TF transmitted from the SAP.

[0231] For example, in the present disclosure, the duration field of the CTS frame can be set as shown in FIG. 23.

[0232] FIG. 23 illustrates an example of setting a duration field in a CTS frame according to an embodiment of the present disclosure.

[0233] Referring to FIG. 23, in a TXOP sharing procedure based on C-TDMA, the duration field of the CTS frame may be set based on the value of the allocation interval subfield in the user information field of the MU-RTS TXS TF. If the value of the duration field of the CTS frame is set to the value obtained by subtracting the time between the end of reception of a PPDU including the MU-RTS TXS TF and the end of transmission of a PPDU including a CTS frame for the MU-RTS TXS TF from the value of the duration / ID field of the MU-RTS TXS TF, a protection issue for the OBSS STA may occur as in FIG. 20 (i.e., the OBBS STA sets the NAV). To solve this protection issue, a method for setting the duration field of the CTS frame as illustrated in FIG. 23 may be applied. The DAP can set the value of the duration field of the CTS frame based on the allocated interval value (i.e., the value of the allocated interval (sub)field) included in the user information field corresponding to the AID of the DAP in the received MU-RTS TXS TF, and transmit this CTS frame as a response to the MU-RTS TXS TF. The allocated interval (sub)field in the user information field of the MU-RTS TXS TF transmitted from the SAP includes a time / interval value allocated to the DAP in the TXOP interval, and the time / interval allocated to the DAP in the TXOP interval may mean the time / interval during which the DAP actually performs FE.

[0234] Therefore, OBSS STAs that receive a CTS frame with a duration field value set based on the allocated interval value of the MU-RTS TXS TF can perform FE from the time point when the allocated time to the DAP has elapsed (i.e., after the basic NAV counter becomes 0).

[0235] FIG. 24 illustrates an example of a C-TDMA procedure in which the duration field value of a CTS frame is set based on an allocation interval value according to an embodiment of the present disclosure.

[0236] Referring to FIG. 24, in a TXOP sharing procedure based on C-TDMA, OBSS STAs can receive a CTS frame in which the duration field is set based on the value of the allocation interval field in the user information field of the MU-RTS TXS TF, and can set a default NAV based on the duration field of the received CTS frame. In a C-TDMA-based TXOP sharing procedure in which a SAP shares a portion of the TXOP interval it has acquired with a DAP, OBSS STAs that detect a CTS frame transmitted from a DAP can set a default NAV based on the CTS frame. At this time, since the duration field of the CTS frame includes the value of the allocation interval field, which is the time when the DAP was actually allocated from the SAP, the default NAV set by the OBSS STA can have a value of 0 at the time when the corresponding allocation interval ends. After the allocation interval ends, the remaining TXOP interval may result in a TXOP sharing procedure with an FE or other DAP within the BSS of SAP, and the OBSS STAs whose primary NAV by the DAP has expired in the remaining TXOP interval may perform individual FE through the available channel.

[0237] According to embodiments of the present disclosure, when a default NAV is set for OBSS STAs that receive a CTS frame transmitted from a DAP in response to an MU-RTS TXS TF transmitted from a SAP in a TXOP sharing procedure based on C-TDMA, a protection issue due to the default NAV setting can be resolved. For example, the value of the Duration field of the CTS frame transmitted from the DAP can be set to the value of the Allocation Interval field in the User Information field of the MU-RTS TXS TF. By setting the value of the Duration field of the CTS frame to the value of the Allocation Interval field in the User Information field of the MU-RTS TXS TF, OBSS STAs can set the default NAV only for the intervals that actually require protection, and can perform individual FEs through available channels after the default NAV expires.

[0238] 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 portion 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 based on the processor (111, 121) and memory (112, 122) of FIG. 1, or based on the processor (510) and memory (520) of FIG. 5.

[0239] 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 includes: detecting a CTS (clear to send) frame for a TXS (TXOP sharing) trigger frame including information about an allocation interval within a TXOP (transmission opportunity) interval; identifying a value of a duration field of the CTS frame; and setting a network allocation vector (NAV) during the allocation interval based on the value of the duration field of the CTS frame being set to a value corresponding to the allocation interval.

[0240] 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 the AP in the present disclosure. The method includes: receiving a TXS (TXOP sharing) trigger frame including information about an allocation period within a TXOP (transmission opportunity) period; setting a value of a duration field of a CTS (clear to send) frame to a value corresponding to the allocation period; and transmitting the CTS (clear to send) frame in response to the TXS trigger frame.

[0241] 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 recording medium containing instructions that are executed by at least one processor.

[0242] 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), the processing chip (114) of FIG. 1, and / or the processor (510) of FIG. 5). The method includes: detecting a CTS (clear to send) frame for a TXS (TXOP sharing) trigger frame including information about an allocation period within a TXOP (transmission opportunity) period; identifying a value of a duration field of the CTS frame; and setting a NAV (network allocation vector) during the allocation period based on the value of the duration field of the CTS frame being set to a value corresponding to the allocation period.

[0243] 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 the 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: receiving a TXS (TXOP sharing) trigger frame including information about an allocation period within a TXOP (transmission opportunity) period; setting a value of a duration field of a CTS (clear to send) frame to a value corresponding to the allocation period; and transmitting the CTS (clear to send) frame in response to the TXS trigger frame.

[0244] The technical features of the present disclosure described above are applicable to various applications and business models. For example, the technical features described above can be applied to wireless communication in devices that support artificial intelligence (AI).

[0245] Artificial intelligence (AI) is the study of artificial intelligence or the methodologies for creating it, while machine learning (ML) defines various problems in the field of AI and studies the methodologies for solving them. Machine learning is also defined as an algorithm that improves performance on a task through consistent experience.

[0246] An artificial neural network (ANN) is a model used in machine learning. It can refer to a model with problem-solving capabilities, consisting of artificial neurons (nodes) formed by the connection of synapses to form a network. An ANN can be defined by the connection patterns between neurons in different layers, the learning process that updates model parameters, and the activation function that generates output values.

[0247] An artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer contains one or more neurons, and the artificial neural network may include synapses connecting neurons. In an artificial neural network, each neuron can output a function value of an activation function based on input signals, weights, and biases received through the synapses.

[0248] Model parameters are parameters determined through learning, including synaptic connection weights and neuron biases. Hyperparameters are parameters that must be set before learning in machine learning algorithms, including the learning rate, number of iterations, mini-batch size, and initialization function.

[0249] The goal of artificial neural network training can be seen as determining model parameters that minimize a loss function. The loss function can be used as an indicator for determining optimal model parameters during the artificial neural network training process.

[0250] Machine learning can be classified into supervised learning, unsupervised learning, and reinforcement learning depending on the learning method.

[0251] Supervised learning refers to a method for training an artificial neural network when given labels for the training data. The labels can refer to the correct answer (or output value) that the artificial neural network must infer when the training data is input to the artificial neural network. Unsupervised learning can refer to a method for training an artificial neural network when the training data is not given labels. Reinforcement learning can refer to a learning method in which an agent defined within a given environment is trained to select actions or action sequences that maximize the cumulative reward in each state.

[0252] Machine learning implemented with a deep neural network (DNN) containing multiple hidden layers among artificial neural networks is also called deep learning, and deep learning is a subset of machine learning. Hereinafter, the term "machine learning" is used to encompass deep learning.

[0253] Additionally, the above-described technical features can be applied to wireless communication of robots.

[0254] A robot can be defined as a machine that automatically performs or operates a given task based on its own capabilities. Specifically, a robot capable of perceiving its environment, making independent judgments, and performing actions can be called an intelligent robot.

[0255] Robots can be categorized into industrial, medical, household, and military applications based on their intended use or field. Robots are equipped with actuators or motors, enabling them to perform various physical actions, such as moving robot joints. Furthermore, mobile robots incorporate wheels, brakes, and propellers into their actuators, enabling them to move on the ground or fly in the air.

[0256] Additionally, the above-described technical features can be applied to devices that support extended reality.

[0257] Extended reality is a general term for virtual reality (VR), augmented reality (AR), and mixed reality (MR). VR technology presents real-world objects and backgrounds as CG images only, AR technology presents virtual CG images over images of real objects, and MR technology is a computer graphics technology that blends and combines virtual objects with the real world.

[0258] MR technology is similar to AR in that it presents both real and virtual objects simultaneously. However, while AR uses virtual objects to complement real objects, MR uses virtual and real objects on an equal footing.

[0259] 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.

[0260] The present disclosure may have various advantageous effects.

[0261] For example, in a TXOP sharing procedure based on C-TDMA, based on setting the duration field of the CTS frame to a specific value, OBSS STAs that do not participate in C-TDMA and can detect the CTS frame of the DAP may not set an unnecessary default NAV.

[0262] The beneficial effects that can be achieved through specific embodiments of the present disclosure are not limited to the beneficial effects listed above. For example, various technical effects may 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, but may include various effects that can be understood or derived from the technical features of the present disclosure.

[0263] 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. Furthermore, the technical features of the method claims of this disclosure 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 of this disclosure and the technical features of the device claims of this disclosure may be combined and implemented as a method.

Claims

1. A method performed by a STA (station) in a wireless local area network (LAN) system, A step of detecting a CTS (clear to send) frame for a TXS (TXOP sharing) trigger frame containing information about an allocation interval within a TXOP (transmission opportunity) interval; A step of identifying the value of the duration field of the CTS frame; and A method comprising the step of setting a network allocation vector (NAV) during the allocation interval based on the value of the duration field of the CTS frame being set to a value corresponding to the allocation interval.

2. In claim 1, the value of the duration field of the TXS trigger frame is set to a value corresponding to the TXOP section, A method in which the value of the duration field of the CTS frame is different from the value of the duration field of the TXS trigger frame.

3. In claim 1, the value of the duration field of the TXS trigger frame indicates the point in time when the TXOP section ends, A method in which the value of the duration field of the above CTS frame indicates the point in time when the above allocation interval ends.

4. In claim 1, the allocation interval includes a time interval allocated to an AP (access point) within the TXOP interval, A method in which information about the above allocation interval is included in the user information field for the AP in the above TXS trigger frame.

5. In claim 4, during the allocation period: The STA for which the above NAV is set skips frame exchange; and A method in which the above AP performs frame exchange with an STA connected to the above AP.

6. In claim 4, the BSS (basic service set) to which the AP belongs is different from the BSS to which the STA belongs.

7. A method according to claim 1, further comprising the step of performing frame exchange after the NAV expires within the TXOP period.

8. In claim 1, the NAV expires at the end of the allocation period.

9. 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 memory stores instructions for performing operations based on being executed by the at least one processor, the operations being: An operation of detecting a CTS (clear to send) frame for a TXS (TXOP sharing) trigger frame containing information about an allocated interval within a TXOP (transmission opportunity) interval; An operation for identifying the value of the duration field of the CTS frame; and An STA including an operation of setting a network allocation vector (NAV) during the allocation period based on the value of the duration field of the CTS frame being set to a value corresponding to the allocation period.

10. In a device configured to operate in a wireless local area network (LAN) system, at least one processor; and 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 being: An operation of detecting a CTS (clear to send) frame for a TXS (TXOP sharing) trigger frame containing information about an allocated interval within a TXOP (transmission opportunity) interval; An operation for identifying the value of the duration field of the CTS frame; and A device including an operation of setting a network allocation vector (NAV) during the allocation interval based on the value of the duration field of the CTS frame being set to a value corresponding to the allocation interval.

11. A non-transitory computer readable medium (CRM) storing program code that implements instructions that perform operations based on being executed by at least one processor, wherein the operations are: An operation of detecting a CTS (clear to send) frame for a TXS (TXOP sharing) trigger frame containing information about an allocated interval within a TXOP (transmission opportunity) interval; An operation for identifying the value of the duration field of the CTS frame; and A CRM including an operation of setting a network allocation vector (NAV) during the allocation interval based on the value of the duration field of the CTS frame being set to a value corresponding to the allocation interval.

12. In a method performed by an access point (AP) in a wireless local area network (LAN) system, A step of receiving a TXS (TXOP sharing) trigger frame including information on an allocation section within a TXOP (transmission opportunity) section; A step of setting the value of the duration field of the CTS (clear to send) frame to a value corresponding to the allocated interval; and A method comprising the step of transmitting the CTS (clear to send) frame in response to the TXS trigger frame.

13. In a wireless local area network (LAN) system, at the AP (access point), Transmitter and receiver; memory; and At least one processor functionally coupled with the transceiver and the memory, The memory stores instructions for performing operations based on being executed by the at least one processor, the operations being: An action of receiving a TXS (TXOP sharing) trigger frame containing information about an allocation interval within a TXOP (transmission opportunity) interval; An operation of setting the value of the duration field of the CTS (clear to send) frame to a value corresponding to the allocated interval; and An AP comprising an operation of transmitting a CTS (clear to send) frame in response to the TXS trigger frame.

14. In claim 13, the value of the duration field of the TXS trigger frame is set to a value corresponding to the TXOP section, The value of the duration field of the above CTS frame is different from the value of the duration field of the above TXS trigger frame.

15. In claim 13, the value of the duration field of the TXS trigger frame indicates the point in time when the TXOP section ends, The value of the duration field of the above CTS frame indicates the AP when the above allocation interval ends.

16. In claim 13, the allocation interval includes a time interval allocated to the AP within the TXOP interval, Information about the above allocation interval is included in the user information field for the AP in the TXS trigger frame.

17. In claim 13, based on the CTS frame being detected by the STA (station), the STA is an AP that sets a network allocation vector (NAV) during the allocation period.

18. In claim 17, during the allocation period: The STA for which the above NAV is set skips frame exchange; and The above AP is an AP that performs frame exchange with an STA connected to the above AP.

19. In claim 17, the BSS (basic service set) to which the AP belongs is a different AP from the BSS to which the STA belongs.

20. In claim 17, the STA performs frame exchange after the NAV expires within the TXOP period, The above NAV is the AP that expires at the end of the above allocation period.

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